Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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TITLE OF THE INVENTION
METHOD AND APPARATUS FOR PAINTING 08JECT
BACKGROUND OF THE INVENTION
The present invention relates a method of and an
apparatus for painting an object, and more particularly to
a method of and an apparatus for painting an inner surface
and outer surfaces such as side and upper surfaces of an
automotive vehicle body without paint coat irregularties
and efficiently within a small space, so that painted
products of high quality can be obtained.
Automobile industry in recent years employs
highly automated line production processes for efficiently
m2ss-producing automobile products. To meet d~sired
mass-production requirements, there are used assembling
-~paratus for assembling individual parts and conveyor
apparatus for conveying components to respective working
positions. Painting apparatus for painting automobile
bodies are also automatized.
Various methods have heretofore been employed for
automatically painting automobile bodies. According to one
known painting method, for example, an automotive vehicle
body is conveyed by a conveyor a~paratus, a~d sprays of
paint are applied from a plurality of paint s~ray guns to
side panels, an engine hood, a roof, a~d a trunk lid of the
vehicle body aq it is conveyed, so that the vehicle body
will be painted.
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In the above painting method, however, the
vehicle body tends to vibrate while it is being conveyed,
with the result that a desired paint coating will not be
applied accurately but paint coat irregularities will
result. Vehicle body painting is one of critical
requirements for determining the quality of completed
automobiles. Automobiles with paint coat irregularities or
defects cannot be sold in the market. Automotive vehicle
bodies with such a defective coating must be painted again
to mend the paint defect.
Should a vehicle body being conveyed while a
paint coat is being applied be positionally displaced as
wel] as vibrated, a paint defect will also arise.
Therefore, vehicle bodies must be fixed in position with
respect to the conveyor apparatus, but the procedure for
securing the vehicle bodies against vibration and
positional displacement is tedious and time-consuming.
Another painting method which h~s been used keeps
an automotive vehicle body at rest in a painting position
and displaces a painting apparatus with a plurality of
paint spray guns with respect to the vehicle body for
coating the same. The paint spray guns are arranged in an
inverted U-shaped pattern so that they confront the side
panels and upper panel of the vehicle body. More
specifically, the inverted U-shaped painting apparatus
includes two side painting mechanisms located on opposite
sides and each having a plurality of paint spray guns, and
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an upper painting mechanism located on the upper sLde and
having a plurality of paint spray guns directed downwardly.
The upper and side painting mechani~ms are displaced in
unison by a COnvQyOr mechanism with respect to the vehicle
body, and a paint coating is applied all over the vehicle
body by the paint spray gUns-
However, since the upper and side painting mechanismsare moved in unison with re~pect to the vehicle body, a
complex process is required for controlling the upper and
side painting mechanisms. More specifically, the upper and
side panels of the vehicle body to be painted are of
different surface areas, and the upper panel surface lies
~ubstantially horizontally whereas the side panel surfaces
are inclined considerably with respect to the vertical
direction. In order to paint the upper and side panel
surfaces appropriately, therefore, the spray guns must be
moved at different speeds, and painting conditions such as
the rates at which the paint is delivered from the spray
guns must be different from painting mechanism to painting
mechani3m. ~ith the conventional inverted U-shaped
painting apparatus, since the upper and side painting
mechanismM are moved at~the 3ame ~peed, the coating film on
the upper panel surface of the vehicle body tends to be of
a small thickness, or paint runs and sags are apt to be
produced on the side panel surfaces. Therefore, the rates
of discharge of the paint from the spray guns should
carefully be controlled.
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Where the upper and side painting mechanisms are moved
t_gether, the spray guns in the uppermo~t position on the
side painting mechanisms and those at the end~ of the uppsr
painting mechanism spray the paint in very close areas, and
hence the paint sprays from these spray guns interfere with
each other. In electrostating painting where paint is
applied under electrostatic forces, the paint particles are
electrostatically repelled from each other, resulting in a
greater tendency of paint spray interference. Moreover,
the paint coat is apt to have different thicknesses which
will have to be uniformized by re-painting. Thus, the
entire painting procedure is complex, making it difficult
to accomplish an efficient automobile production process.
SUMMARY OF THE INVENTION
In view of the aforesaid difficulties of the
conventional painting methods and apparatus, it is an
object of the present invention to provide an improved
method and apparatus for painting an object.
In one aspect of the invention there is provided
a method of painting an ob~ect having a surface including a
bent or curved portion, comprising the steps of:
moving paint spraying means and applying paint
sprays therefrom to said surface of the object while they
are being directed substantially perpendicularly to and
spaced a constant distance from the surface of the object;
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turning said paint spray means so as to be
directed substantially perpendicularly to and spaced a
constant distance from the bent or curved portion of the
surface of the object;
then moving said paint spray means and applying
paint sprays therefrom to said bent or curved portion; and
repeating the above steps to paint the object.
Another aspect of the invention provides a method
of painting an object having a surface, comprising the
steps of:
delivering the object along a painting line with
said object having a longitudinal direction substantially
perpendicular to a painting direction;
moving said object and paint spraying means
relatively in said painting direction;
directing said paint spraying means substantially
perpendicularly to said surface of the ob~ect and keeping
the paint spraying means a prescribed distance from said
surface of the ob~ect; and
then applying paint sprays from said paint
spraying means to said surface for thereby painting said
ob~ect.
The invention also provides an apparatus for
painting an object in a transverse direction thereof which
is delivered along a painting line, the ob~ect having
opposite longitudinal end surfaces, opposite transverse
side surfaces, and an upper surface comprising:
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a first painting mechanism for painting said side
and upper surfaces of the object, said first painting
mechanism having an angularly movable and/or vertically
movable arm extending substantially longitudinally of the
object, and a plurality of paint spraying means mounted on
said arm in spaced relation; and
a second painting mechanism for painting said end
surfaces of the object.
An apparatus for painting an object having a
surface is also provided and comprises:
a first mobile body movable along said object;
a second mobile body mounted on said first mobile
body and movable while being directed toward said ob~ect;
paint spraying means mounted on said second
mobile body and directed toward said ob~ect for applying
paint sprays to said surface of the ob~ect; and
turning means for turning said paint spraying
means about an axis normal to the direction in which said
first and second mobile bodies are movable.
The apparatus may further include a guide rail
disposed on one ~ide of the ob~ect, and a first drive
source, said first mobile body being movable along said
guide rail by said first drive source.
The apparatusBm~ey further include a second drive
source, said second movablo body being movable in a
vertical direction along said first mobile body by said
second drive source, said paint spraying means being
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angularly movable by said turning means for applying paint
sprays substantially perpendicularly to ~aid surface of the
ob~ect.
Shifting means may be provided for ~hifting said
paint spraying m0ans along said axi~.
A still-further aspect of the invention provides
an apparatus for painting an object having first, second,
and third surfaces, comprising:
moving means;
first, second, and third painting mechanisms
having paint spraying means for applying paint sprays to
the first, second, and third surfaces, respectively, of the
ob~ect while said first, second, and third painting
mechani~ms are being moved by said moving means in the
vicinity of the ob~ect;
said first, second, and third painting mechani~ms
having first, second, and third painting distance ad~usting
means, respectively, for moving said paint spraying mean~
towards and away from said ob~ect;
at least one of said first, second, and third
painting mechanisms having painting angle ad~usting means
for modifying the posture of the paint spraying means
thereof by swinging the latter; and
whereby the distances between the paint spraying
means of said first, second and third painting mechanism~
and said first, second, and third surfaces of the ob~ect
can be equalized by said flrst, second, and third painting
distance ad~usting means, respectively, and the angle of
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said paint spraying means of the painting mechanism which
has said painting angle ad~usting means with respect to the
corresponding surface of the object can be kept constant by
said painting angle ad~u~ting means.
Where the ob~ect comprises an automotive vehicle
body, said first, second, and third surfaces of the ob~ect
corresponding to an upper portion of the vehicle body
including a front body surface, an engine hood, a roof, a
trunk lid, and a rear body surface, a lefthand side surface
including a lefthand door, and a righthand side surface
including a righthand door, the painting angle ad~usting
means is incorporated in said first painting mechanism
which paints said upper portion of the vehicle body.
Each of said first, second, and third painting
distance adjusting means may comprise a servomotor, a ball
screw coupled to a drive shaft of said 3ervomotor, and a
holder mechanism held in threaded engagement with said ball
screw and holding a swing arm on which said paint ~praying
means is mounted, whereby said ball screw can be rotated by
said servomotor for displacing said holder mechanism to
ad~ust the distance between the paint spraying means and
one of the surfaces of the ob~ect.
Each of said first, second, and third painting
distance ad~usting means may comprise a servocylinder, a
post engaging a piston rod of said Rervocylinder, and a gun
arm fixed to said servocylinder and supporting said paint
spraying means, whereby said servocylinder can be driven to
displace the servocylinder and said gun arm in unison to
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adjust the distance between the paint spraying means and
one of the surfaces of the object.
In a painting apparatus in which said painting
distance adjusting means has a holder mechanism, the
painting angle ad~ustin~ means may comprise a servomotor
held by said holder mechanism, a first gear mounted on a
drive shaft of said servomotor, a second gear meshing with
said first gear, and a swing arm coupled to said second
gear, whereby said qervomotor can be driven to rotate said
first and second gears to tilt said swing arm for ad~usting
the angle of a distal end of said paint spraying means.
The invention further provides an apparatus for
painting an object having an upper portion, comprising:
an upper painting mechanism having a plurality of
paint spraying means and displaceable with respect to the
object for applying paint sprays from said paint spraying
means to said upper portion of the ob~ect in a painting
direction;
shifting means mounted on said upper painting
mechanism for shifting said paint spraying means in a
direction different from said painting direction; and
said shifting means comprising a displaceable
outer cylindrical member on which said paint spraying means
are mounted, an inner cylindrical member having one end
fixed to a body of said upper painting mechanism and fitted
in said outer cylindrical member for guiding the same, and
an actuator for moving said outer cylindrical member
axially back and forth;
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said upper painting mechanism further including a
cover fixed to one end of said outer cylindrical member in
surrounding relation to relatively slidable portions of
said outer and inner cylindrical members, and a ~oint
displaceable interconnecting the other end of said outer
cylindrical member and said actuator.
The said actuator may comprise a cylinder,
further including a rod attached to said cylinder and
inserted through said inner cylindrical member, ~aid outer
cylindrical member engaging an end of said rod through an
engagement member, whereby said cylinder can be operated to
cause ~aid rod to move said outer cylindrical member for
thereby ~hifting said paint spraying means on the outer
cylindrical member in said direction different from the
painting direction.
An apparatus for painting an ob~ect is also
provided and comprises a transfer path extending on at
least one side of the ob~ect;
a painting mechanism movable on ~aid transfer
path, said painting mechanism having a roller;
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said transfer path comprising a rail on which
said roller is rollingly mounted for moving said painting
mechani m, and a plate-like cover member surrounding said
rail and said roller and extending along said transfer
path, whereby paint sprays from said painting mechanism are
prevented by said cover member from being applied to said
rail or said roller when the paint spray~ are applied to
the object by ~aid painting mechanism while moving on said
transfer path.
The transfer path may include a rail bracket
having a pair of rail~, said cover member being of an
inverted channel-shaped cross section fixed to said rail
bracket and surrounding upper and lateral sideY of said
rail~.
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The above and other ob~ects, features and
advantages of the present invention will become more
apparen~ from the following description when taken in
conjunction with the accompanying drawings in which
preferred embodiments of the present invention are shown by
way of illustrative example.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a plan view of a painting line
according to the present invention;
FIG. 2 is a block diagram of a painting control
~ystem according to the present invention;
FIG. 3 is a plan view of a painting apparatus of
the present invention;
FIG. 4 is a front elevational view of the
painting apparatus of the present invention;
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FIG. 5 is a cross-sectional view of a transport
means in the painting apparatus;
FIG. 6 is an elevational view, partly in cross
section, of an upper painting mechanism of the painting
apparatus;
FIG. 7 is an elevational view, partly in cross
section, of a side painting mechanism of the painting
apparatus;
FIG. 8 is a block diagram of a drive control
system for the upper painting mechanism;
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FIG. 9 is a block diagram of a drive control system
for the side painting mechanism;
FIG. 10 is a side elevational view showing the manner
in which an upper vehicle body portion i~ painted by tne
upper painting mechanism;
FIG. 11 is a fragmentary side elevational view of a
cleaning device according to the present invention;
FIG. 12 is a vertical cross-sectional view of a
cleaning tank of the cleaning device;
FIG. 13 is a cross-sectional view taken along line
XIII - XIII of FIG. 12;
FIG. 14 i~ a flowchart of a control sequence of the
painting control system;
FIG. 15 is a plan view of a painting apparatus for
carrying out a painting method according to the present
invention;
FIG. 16 i8 a side elevational view, partly in cxoss
section, of the painting apparatus illu~trated in FIG. 15;
FIG. 17 is an enlarged view of paint spray gun of the
painting apparatus;
FIG. 18 is a view showing the manner in which an
automotive vehicle body is painted by the painting
apparatu~;
FIG. 19 i8 a plan view of the painting apparatu3
according to another embodiment for carrying out the
painting method of the invention;
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FIG. 20 is a side elevational view, partly in cross
section, of a painting apparatus of the invention and a
holder mechanism incorporated therein;
FIG. 21 is a view of the holder mechanism mounted in a
side painting mechani~m of the painting apparatus;
FIG. 22 is a fragmentary perspective view of the
holder mechanism; and
FIG. 23 is a cross-sectional view taken along line
XXIII - XXIII of FIG. 21.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT5
FIG. 1 shows a painting line 10 for painting
automotive vehicle bodies, the painting line 10 being
divided into a first painting stage 10a, a second painting
stage 10b, a third painting stage 10c, and a fourth
painting stage 10d for painting respective different areas
or surfaces of the vehicle bodies.
In the first painting stage 10a, the engine
compartment and trunk compartment of each of the vehicle
bodies 14 are painted. The first painting stage 10a
includes painting mechanisms 18a through 18d movably
mounted on rails 16a, 16b disposed on opposite sides of the
first painting ~tage 10a. The first painting stage 10a
also include~ an angine hood opening/closing mechanism 20
and a trunk lid opening/closing mechanism 22. The painting
line 20 includen a vehicle body conveyor mechanism 24
extending centrally from the first to fourth painting
staqes 10a through 10d.
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In the second painting stage lOb, the inner surfaces
of doors of each vehicle body 14 are painted. The second
painting 3tage lOb include~ painting mechanisms 28a, 28b
movably mounted respectively on rails 26a, 26b dispo~ed on
opposite sides of the second painting stage lOb.
Additional rails 30a, 30b are disposed bstween the vehicle
body conveyor mechanism 24 and the rails 26a, 26b, and door
opening/closing mechanisms 32a, 32b are movably mounted on
the rails 30a, 30b, respectively.
In the third painting stage lOc, the outer panels
including the engine hood, trunk lid, roof, and doors of
each vehicle body 14 are painted. A painting apparatu-~ 12
is disposed in the third painting stage lOc for painting
these outer panels, and comprises rails 34a, 34b disposed
parallel to each other on the opposite sides of the vehicle
body conveyor mechanism 24, an upper painting mechanism 36
and a lefthand side painting mechanism 38 which are movable
along the rail 34a, and a righthand side painting mechanism
40 movable along the rail 34b. The third painting stage
lOc includes cleaning devices 336, 338, 340 for cleaning
paint spray guns of the painting mechanisms 36, 38, 40 when
paint colors are to be changed. In this embodiment r thQ
upper painting mechanism 36 is movable along the rail 34a.
However, as shown in FIG. 3, another rail 34c may be
disposed outside of the rail 34a, and the upper painting
mechanism 36 may be movably disp~ed on the rail 34c for
travel independent of the lefthand side painting mechanism
38.
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In the fourth stage 30d, the painted vehicle body 14
i~ dried. In the fir~t through third painting stages lOa -
lOc, the electrostatic painting process is employed in
which the paint is electrostatically applied to the vehicle
bodies.
The painting line 10 is controlled by a painting
control system 400. The painting control system 400 is
mainly composed of a line master controller 410 for
controlling the overall painting system, and stage master
controllers 412a, 412h, 412c for controlling the first
through third painting stages lOa - lOc, respectively. The
stage master controller 412a, which controls the first
painting stage lOa, is connected to an opening/closing
controller 420 for controlling the engine hood
opening/closing mechanism 20 and the trunk lid
openingtclo~ing mechanism 22, and a painting robot
controller 422 and a painting controller 424 for
controlling the painting mechanisms 18a through 18d. The
stage master controller 412b, which control~ the second
painting stage lOb, i~ connected to an opening/closing
controller 430 for controlling the door opening/closing
mechanisms 32a, 32b, and a painting robot controller
432 and a painting controller 434 for controlling the
painting mechsnisms 28a, 28b. The stage master
controller 412c, which controls the third painting stage
lOc, is connected to a painting robot controller 442
and a painting controller 444 for~
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controlling the painting mechanisms 36, 38, 40 and the
cleaning devices 336, 338, 340.
These stage master controllers 412a through 412c
are coupled to the line master controller 410 and
responsive to commands issued therefrom for controlling the
painting operation in the respective painting stages 10a
through 10c. The stage master controllers 412a through
412c also deliver prescribed status information to the line
master controller 410. To the line master controller 410,
there is also connected a monitor device 414 for monitoring
various portions of the painting line. The vehicle body
conveyor mechanism 24 is controlled by the line master
controller 410 for conveying vehicle bodies 14 to be
painted and positioning them in the respective painting
stages. Commands are transferred to the stage master
controllers 412a through 412c in synchronism with operation
timing of the conveyor mechanism 24.
The line master controller 410 is notified of
accidents or other abnormal coDditions such as a fire in
the paintiDg stages 10a through 10c, and controls the
monitor device 414 to indicate such an accident.
Operation of the painting control system will be
described below.
A vehicle body 14 which has been delivered to the
first stage 10a by the conveyor mechanism 24 is first
accessed by the engine hood opening/closing mechanism 20,
which opens the engine hood, and by the trunk lid opening/
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closing mechanism 22, which opens the trunk lid. The
engine compartment and the trunk compartment are then
painted by the painting mechanisms 18a through 18d which
run along the rails 16a, 16b. Thereaftex, the engine hood
and the trunk lid are closed by the respective
opening/closing mechani~ms 20, 22, and then the vehicle
body 14 is conveyed to the second stage lOb by the conveyor
mechanism 24.
In the second stage lOb, the doors of the vehicle body
14 are opened by the door opening/closing mechanisms 32a,
32b, and the inner surface~ of the opened doors are painted
by the painting mechanisms 28a, 28b which travel along the
rails 26a, 26b. ~he doors are thereafter closed by the
door opening/closing mechanisms 32a, 32b, and the vehicle
body 14 is fed to the third stage lOc by the conveyor
mechanism 24.
In the third stage lOc, the upper, lefthand and
righthand side painting mechanisms 36, 38, 40 are
positioned in front of the vehicle body 14 which has been
delivered from the second stage lOb.
When the vehicle body 14 i8 positioned in the third
stage lOc, the upper, lefthand and righthand side painting
mechanisms 36, 38, 40 run along the rails 34a, 34b while
painting the engine hood, the roof, the trunk lLd, and the
side panels of the vehicle body 14. The vehicle body 14
which has been painted i9 then fed by the conveyor
mechsnism 14 to the fourth stage lOd where the vehicle body
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14 is dried.
The line master controller 410 controls the operation
of the con~eyor mechanism 24, and ~upplies the stage master
controllers 412a through 412c with various items of command
information as to a vehicle type and a paint color, for
example, in timed relation to the operation of the conveyor
mechanism 24 to start delivering the vehicle body 14. In
synchronism with the timing when the vehicle body is
brought by the conveyor mechani~m 24 to the painting stages
lOa through lOc, the stage macter controllers 412a through
412c supply the command information as to the vehicle type,
the paint color, and the like to working component
controller such as the opening/closing controllers 420,
430, the painting robot controllers 422, 432, 442, and the
painting controllers 424, 434, 444 to indicate the starting
of operation of the painting stages lOa through lOc. The
working component controllers then use the command
information as keys for effecting a preset operation
sequence (processing program) thereby to control the
working components. The opening/closing controller 420
opens or clos-s the engine hood opening/closing mechanism
20 and the trunk lid opening/closing mechanism 22, which
are working components, in a prescribed order and at
pre~cribed timing. Similarly, the opening/closing
controller 430 opens or closes the door opening/closing
mechanisms 32a, 32b in a prescribed order and at prescribed
timing.
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The painting robot controllers 422, 432, 442 execute
the prescribed processing program based on the indicated
vehicle type, etc., for controlling the operation of the
painting mechanisms lRa through 18d, 28a, 28b, 36, 38, 40,
and applying painting commands to the painting controllers
424, ~34, 444, which responds to the indicated paint color
for controlling the rate of discharge of the paint, the
rate of discharge of air, and the electrostatic voltage for
the painting mechanisms 18a - l~d, 28a, 28b, 36, 38, 40.
When a command is gi~en to change paint color~, the
painting controllers effect a cleaning process for the
painting mechanisms.
The line master controller 410 receives ~tatus signals
from the conveyor mechanism 24, the painting stages lOa
through lOd, the stage ma~ter controllers 412a through
412c, the working eomponent controllers (the
opening/closing eontroller 420 and others), and the working
eomponent~ (such a~ the trunk lid opening/closing mechanism
20, the painting mechanism 36, and the like), and issue~
information as to operating and abnormal eondition~ of the
eontrol system to the monitor doviee 414. ~hus, the line
master eontroller 410 monitor~ the operating conditiQn of
the painting line, controls painting eonditions, effects
failure diagnoses, periodic inspections, and colleets or
issues produetion eontrol information.
The painting line aeeording to the present invention
is basieally arranged and operated as deseribed
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above. The painting mechanisms in the third stage lOc, for
example, will be described in greater detail.
In the third stage lOc, the upper painting
mechanism 36, the lefthand side painting mechanism 38, and
the righthand side painting mechanism 40 are moved along
the rails 34a, 34b by transport means which are of
essentially the same design. More specifically, as shown
in FIG. 5, the rails 34a, 34b are constituted by a rail
bracket 42 extending from one end to the other of the rails
34a, 34b. To the upper surface of the rail bracket 42,
there are fixed spacers 44a, 44b with rails 48a, 48b
secured to their upper surfaces by means of bolts 46. A
rack 52 is attached to a vertical outer side of the rail
bracket 42 by a support member 50, the rack 52 e~tending
parallel to the rail 48a. Two vertical posts 54a, 54b are
mounted on the upper surface of the rail bracket 42, and a
protective oovær 56 having an inverted channel-shaped cross
section is fised to the upper ends of the posts 54a, 54b.
The protective cover 56 extends along the rails 48a, 48b.
The protective cover 56 has laterally spaced depending legs
56a, 56b proJecting downwardly and spaced from the sides of
the rail~ 48a, 48b by prescribed gaps.
The upper, lefthand and righthand side painting
mech~ism~ 36, 38, 40 have outer frames comprising ca~ings
58a through 58c with a plate 60 secured to the lower end
thereof. Side plates 62a, 62b are vertically affixed to
the opposite edges of the lower surface of the plate 60. A
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support member 64 is secured to the lower end of the side
plate 62a, and a transport motor 66 is fixed to the lower
end of the support member 64. The transport motor 66 has a
rotatable shaft 68 supporting on its distal end a pinion 70
meshing with the rack 52 fixed to the rail bracket 42.
A roller assembly 72a is mounted on the upper end of
the support member 64. The roller as~embly 72a comprise~ a
roller 74 held in rolling engagement with the upper surface
of the rail 48a, a pair of rollers 78a, 78b ~upported on a
plate 76 fixed to the roller a~sembly 72a and rollingly
held against the opposite sides of the rail 48a, and a
roller 80 held in rolling contact with the lower surface of
the rail 48a. Another roller assembly 72b i5 mounted on
the side plate 62a by a support member 82. The roller
assembly 72b comprises a roller 86 rotatably supported on a
shaft 84 and held in rolling engagement with the upper
surface of the rail 48b, and a roller 88 held in rolling
contact with the lower surface of the rail 48b.
The upper painting mechanism 36 will be de~cribed
below. As shown i8 FIGS. 4 and 6, a vertical ball screw 90
is rotatably supported in the casing 58a and ha~ an upper
end coupled to the drive shaft of a lifting/lowering motor
92 mounted on the upper surface of the ca~ing 58a as a
painting di~tance ad~usting means. Four guide rods 94a
through 94d are di~posed vertically parallel to each other
around the ball screw 90. A horizontal support plate 96 is
threadedly disposed around and held in mesh with the ball
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screw 90 and can be moved upwardly and downwardly byrotating the ball screw 90 about its own axis upon
energization of the lifting/lowering motor 92. The guide
rodQ 94a - 94d extend through the ~upport plate 96.
As shown in FIG. 6, a turning motor 100 is fixed to
the upper surface of the support pla-te 96 via a holder 98.
The turning motor 100 has a rotatable shaft 102 on which a
gear 104 is mounted. The holder 98 holds therein a bearing
106 supporting a turning shaft 108 having one end on which
is mounted a gear 110 meshing with the gear 104. The other
end of the turning shaft 108 projects out of the casing
58a, and one end of the swing arm 112 is secured to the
pro~ecting end of the turning ~haft 108.
A shifting cylinder 114 i~ disposed as a shifting
means on the other end of the swing arm 112. The shifting
cylinder 114 has a piston rod 116 extending horizontally in
transverse relation to the rails 34a, 34b. A fixed shaft
118 having one end secured to the swing arm 112 is disposed
loosely around the piston rod 116. A cylindrical slide
sleeve 122 is slidably fitted over the fixed ~haft 118
through slide bearings 120a, 120b interposed therebetween.
Splines 116a are formed on the distal end of the piston rod
116. A guide member 124 fixed to the other end of the
fixed shaft 118 i8 ~lidably fitted over the Rplines 116a.
One end of the splines 116a are affixed to one end of the
slide sleeve 122. Between the other end of the slide
sleeve 122 and the swing arm 112, there is mounted an
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expandable and contractable bellows~like cover member 126 for
preventing paint deposits from being applied to the fixed
shaft 118.
A horizontal gun arm 132 i8 coupled to the outer
periphery of the slide sleeve 122 through support members 128,
130. Clamp members 134a through 134d are fastened to the
horizontal gun arm 132 in spaced relation to each other. Gun
support bars 136a through 136d are held by the clamp members
134a through 134d, respectively, perpendicularly to the
horizontal gun arm 132. Paint spray guns 140a through 140d
are secured as paint spraying means respectively to the lower
ends of the gun support bars 136a through 136d via
respectively joints 138a through 138d, the paint spray guns
140a through 140d being spaced from each other. To the paint
spray guns 140a through 140d, there are connected to paint
conduit cables 142a through 142d for supplying a paint to the
associated paint spray guns.
The lefthand and righthand side painting mechanisms 38,
serve to paint the lefthand and righthand sides,
respectively, of the vehicle body 14, and are of basically the
same construction. As illustrated in FIGS. 4 and 7, vertical
posts 144a, 144b are disposed in each of the casings 58b, 58c
of the lefthand and righthand side painting mechanisms 38, 40.
Two guide bars 146a, 146b extend horizontally between and are
connected to the posts 144a, 144b in perpendicular relation
to the rails 34a, 34b, and a holder 148 is slidably mounted
on the guide bars
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'' . `
`
13277~
146a, 146b. Expandable and contractable cover member~
150a, 150b are disposed around the guide bars 146a, 146b
betwe~n the holder 148 and the post 144a. A horizontally
moving cylinder 152 is fixed to the holder 148 and has a
piston rod (not shown) with its di.stal end connected to the
post 144b through a joint 154.
A shifting guide bar 158 extends vertically through
and is slidably supported in the holder 148 by means of
slide bearings 156a, 156b. Expandable and contractable
cover members 160a, 160b are disposed around the upper and
lower end portions of the shifting guide bar 158 which
pro~ect from the holder 148. A ~oint 162 is attached to
the lower end of the shifting guide bar 158. A shifting
cylinder 164 i~ fixed as a shifting means to the outer
periphery of the holder 148 through a support member 166,
and has a downwardly extending piston rod 168 coupled to
the ~oint 162 through a guide member 170 affixed to the
holder 148. An expandable and contractable cover member
172 is disposed around the piston rod 168 between the guide
member 170 and the ~oint 162.
A holder 174 i8 coupled to the shifting guide bar 158
at its upper and lower ends. ~ gun arm 178 is supported on
the holder 174 through support members 176a, 176b. To the
gun arm 178, there are attached paint spray guns 182a
through 182d as paint spraying means by means of ~oints
180a through 180d, respectively, the paint spray guns 182a
through 182d being spaced from each other. The paint spray
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guns 182a through 182d are positioned in a vertical pattern
which is shaped complementarily to a side panel of the
vehicle body 14.
The painting apparatus thus constructed is operated by
a drive control system which is arranged as shown in FIG.
8.
As shown in FIG. 8, a control until 1~4 issues a
control signal which has previously been established as by
a teaching process, for controlling operation of the upper
painting mechanism 36. The upper painting mechanism 36 is
driving by a hydraulic servo system comprising a hydraulic
until 185 in the form of a fluid pressure pump or the like,
servovalves 188a through 188c, servoamplifiers l90a through
l90c responsive to the control signal from the control
until 184 for driving the servovalves 188a through 188c,
and a hydraulic motor.
The hydraulic motor comprises the transport motor 66
for moving the upper painting mechanism 36 along the rail
34a, the lifting/lowering motor 92 for moving the swing arm
112 with the paint spray guns 140a through 140d in a
vertical direction, and the turning motor 100 for turning
the ~wing arm 122 around the turning shaft 108. The
rotational speed of the transport motor 66 i~ detected
by a potentiometer 194a through a speed reducer 192a and
fed a~ a positional signal indicative of the position of
the upper painting mechani~m 36 with respect to the rail
34a back to the ~ervoamplifier l90a. Similarly, the
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13277~0
rotational speed of the lifting/lowering motor 92 is
detected by a potentiometer 194b through a speed reducer
192b and fed as a positional signal indicative of the
position of the swing arm 112 with respect to the vertical
direction back to the servoamplifier l90b. The rotational
speed of the turning mo~or 100 i~ detected by a
potentiometer 194c through a speed reducer 192c and fed as
a tilt signal back to the servoamplifier l90c at the time
the swing arm 112 is tilted around the swing arm 108.
As shown in FIG. 9, the lefthand and righthand side
painting mechanisms 38, 40 are driven by a hydraulic servo
system comprising a hydraulic unit 196, servovalves 198a,
198b, servoamplifiers 200a, 200b, a hydraulic motor, and a
hydraulic cylinder. The hydraulic servo system is also
controlled by the control unit 184 which is shared by the
drive control system for the upper painting mechanism 36.
The rotational speed of the transport motor 66 a the
hydraulic motor is detected by the potentiometer 204a
through a speed reducer 202 and fed as a positional signal
indicative of the position of the lefthand and righthand
side painting mechanisms 38, 40 with respect to the rails
34a, 34b back to the servoamplifier 200a. The amount of
displacement of the horizontally moving cylinder 152 as the
hydraulic cylinder i8 detected by the potentiometer 204b
and fed as a positional signal indicative of the position
of the paint spray guns 182~ through 182d with respect to
the vehicle body 14 back to the servoamplifier 200b.
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13~7700
The cleaning devices 336, 338, 400 will hereinafter be
described.
As illustrated in FIG. 11, the cleaning device or
upper painting gun cleaning mechanism 336 includes a base
342 and a body 344 vertically movably and swingably mounted
on the base 342. Support rods 346a, 346b have one ends
attached to an upper portion of the body 344 and extend
horizontally parallel to each other. The ~upport rods
346a, 346b support thereon cleaning tanks 348a through 348d
which are spaced from each other in vertical alignment with
the paint spray guns 140a through 140d, respectively, of
the upper painting mechanism 36.
Since the cleaning tanks 348a through 348d are of the
same construction, only the cleaning tank 348a will be
described below in detail and the other cleaning tanks 348b
through 348d will not be described.
As shown in FIG. 12, the cleaning tank 348a has a base
plate 350 having support member~ 352a through 352b engaging
the support rods 346a, 346b from which the cleaning tank
348a is suspended. The base plate 350 ha~ a relatively
large circular opening 354 defined cen~rally therein.
Flexible cover members 356a, 356b are fixed to the base
plate 350 over the opening 354. The cover members 356a,
356b are of the same shape and have central holes 358a,
358b, respectively, which are of a diameter smaller than
that of nozzles 240a through 240d of the paint spray guns
140a though 140d. The cover members 356a, 356b have
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-
slits (not shown) extending radially outwardly from the
centers of the holes 358a, 358b and spaced from each other.
The flexible cover member~ 356a, 356b are placed one on the
other and fixed to the base plate 350 with the 81it~ not
overlapping each other.
As shown in FIG. 13, support bars 360a through 360d
have one ends secured to the surface of the base plate 350
remote from the support members 352a through 352d, the
support bars 360a through 360d surrounding the opening 354
and being equidi~tantly ~paced from each other. Another
support bar 362 has one end secured to the base plate 350
between the support bars 360c, 360d. Holders 364a through
364d are attached to the other ends of the support bars
360a through 360d, respectively, and cleaning guns 366a
through 366d are mounted respectively on the holders 364a
through 364d. The cleaning guns 366a through 366d have
nozzle ends 368a through 36Bd inclined toward the base
plate 350 and directed to the central axis of the opening
354. A support bar 370 i9 perpendicularly coupled to the
other end of the ~upport bar 362, and a holder 372 is
mounted on the support bar 370. A cleaning gun 374 is
mounted on the holder 372 and has a nozzle ~nd 376 directed
toward the opening 354 in alignment with the central axis
thereof.
A casing 378 i9 detachably mounted on the base plate
350 by means of bolts, for exampIe, defining a cleaning
chamber 380 therein. The cleaning chamber 380 is
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-` 13277~0
held in communication, through the lower end of the
casing 378, with a small-diameter drain/mi~t outlet 382.
In FIG. 11, a conduit 384 is connected to the outlets
382 of the cleaning tanks 384a through 348d, and attached
to the body 344 for vertical and turning movement in unison
therewith. To the conduit 384, there is connected one end
of a flexible conduit 386 with its other end coupled to a
separation tank 388. The separation tank 388 has a mist
conduit 390 on its upper portion and is connected at its
lower portion to a drain conduit 392 which is connected to
a pump 393, for example, that is coupled to a drain
processing unit tnot shown).
The other cleaning devices or side paint spray gun
cleaning mechanisms 338, 340 are structurally identical to
each other. Therefore, only the side paint spray gun
cleaning mechanism 338 will be described below in detail.
The cleaning mechanism 338 includes a base 394 on
which a post 396 is vertically mounted. The po~t 396 has
holder~ 398a through 398d extending horizontally at
different heights. Cleaning tanks 300a through 300d are
supported on the holders 398a through 39Bd, respectively,
in horizontal alignment with the respective paint spray
guns 182a through 182d of the lefthand side painting
mechanism 38. The cleaning tanks 300b, 300d are fixed to
the holders 398b, 398d, respectively, whereas the other
cleaning tanks 300a, 300c are horizontally displaceable.
More specifically, cleaning tank shifting cylinder3 302a,
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132770~
302b are horizontally mounted on the post 396 in vertically
spaced relation to each other, and have respectLve pi~ton
rods 304a, 304b extending horizontally and coupled to the
cleaning tanks 300a, 300c, respectively.
The cleaning tanks 300a through 300d are structurally
substantially the same as the cleaning tank 348a. The
cleaning tanks 300a through 300d have casings 306 on which
there are mounted support members 307a through 307d by
which the cleaning tanks 300a through 300d are suspended
from the holders 398a, 398d and the piston rods 304a, 304b.
The internal structures of the cleaning tanks 300a through
300d are the same a~ that of the cleaning tank 348a, and
hence will not be described in detail.
The casings 306 of the cleaning tanks 300a throu~h
300d are connected at their lower ends to drain/mist
conduit~ 308 that are coupled via a conduit 310 to a
separation tank 312 which has a mist conduit 314 and is
~oined to a drain conduit 316.
The detailed construction of the third painting stage
10c is as described above. Operation of the third painting
stage 10c is as follows t
In the third painting stage 10c, the upper painting
mechanism 36~ the lefthand side painting mechanism 38,
and the righthand side painting mechani~m 40 are
positioned in front of the vehicle body 14 in a waiting
condition. On the upper painting mechani~m 36, the
lifting/lowering motor 92 is operated to rotate the ball
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`
.
.
132770~
screw 90 to lower the swing arm 112 from the position of
FIG. 4 in the direction of the arrow A. At the same time,
the turning motor 100 is operated to turn the swing arm 112
about the turning shaft 108 in the direction of the arrow
B. The paint spray guns 140a through 140d mounted by the
slide sleeve 122 on the end portion of the swing arm 112
are now oriented toward the front head of the vehicle 14,
as shown in FIG. 3.
A painting process effected by the upper painting
mechanism 36 will be described with reference to FIGS. 4, 8
and 10. When a control signal is issued from the control
unit 184, the servoamplifier l90a is controlled by the
control signal to operate the servovalve 188a. A fluid
under pressure supplied from the hydraulic unit 186 is
delivered through the servovalve 188a to drive the
transport motor 66. As a result, the pinion 70 mounted on
the rotatable shaft 68 of the transport motor 66 is rotated
to cause the upper painting mechanism 36 to start running
with the roller assemblies 72a, 72b along the rails 48a,
48b in the direction of the arrow C.
The rotational speed of the tra~sport motor 66,
i.e., the amount of movement of the upper painting
mechanism 36, is detected by the potentio~eter 194a through
the speed reducer 192a. When the spacing between the front
end of the vehicle body 14 and the paint spray guns 140a
through 140d of the upper painting mechanism 36 reaches a
prescribed distance, the potentiometer 194a applies a
- -33-
`` 13277~0
positional signal to the servoamplifier l90a which then
controls the tran3port motor 66 through the servovalve
188a. As a consequence, the di~tance between the ~ront end
of the vehicle body 14 and the paint spray guns 140a
through 140d is kept constant.
Then, the servoamplifier l90b operate~ the servovalve
188b based on a control signal from the control unit 184,
for enabling the fluid under pressure from the hydraulic
unit 186 to drive the lifting/lowering motor 92 through the
servo~alve 188b. Consequently, the ball screw 90 coupled
to the motor 92 is rotated to cause the support plate 96
meshing with the ball screw 90 to start lifting the swing
arm 112 in the direction of the arrow D. Paint spray~ are
ejected from the paint spray guns 140a through 140d toward
the front end of the vehicle body 14 to paint the front end
along a paint line a (FIG. 10).
The paint spray guns 140a through 140d are spaced at
intervals 80 as to prevent the e~ected paint sprays from
interfering with each other. Therefore, the surface of the
front end of the vehicle body 14 is coated with spaced
strips of paint as shown in FIG. 3.
After the front end has been painted and when the
paint spray guns 140a through 140d reach the boundary
be~ween the front end and the engine hood, the
servoamplifier l90c operates the servovalve 188c in
response to a control signal from the control unit 184 for
enablins the fluid under pressure from the hydraulic unit
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13277~0
,
186 to drive ~he turning motor 100 through ~he ~ervovalve
188c. As a consequence, the swing arm 112 is turned about
the turning shaft 108 in the direction of the arrow B by
the gear 110 meshing with the gear 104 mounted on the ~haft
102 of the motor 100. The paint spray guns 140a through
140d coupled by the slide sleeve 122 to the swing arm 112
are now directed perpendicularly to the engine hood of the
vehicle body 14.
The angular displacement of the swing arm 112 is
detected by the potentiometer 194c through the speed
reducer 192c. Nhen the paint spray guns 140a through 140d
are directed perpendicularly to the engine hood, the
potentiometer 194c applies a prescribed tilt signal to the
servoamplifier l90c, which controls the turning motor 100
through the servovalve 188c. The paint spray guns 140a
through 140d are now held perpendicularly to the engine
hood of the vehicle body 14.
Then, the upper painting mechanism 36 is driven by the
transport motor 66 along the rail 34a for painting the
engine hood along a painting line b. The vertical position
of the swing arm 112 is detected by the potentiometer 194b
which detects the rotational speed of the lifting/lowering
motor 92. The potentiometer 194b applies a po-~itional
signal to the servoamplifier l90b to enable the latter to
control the lifting/lowering motor 92 through the
servovalve 188b. Thus, the swing arm 112 is elevated in
the direction of the arrow D as tha upper painting
-35-
-`` 132770~
mechanism 36 advances in the direction of the arrow C, so
that a paint coating of uniform thicknesq can be applied to
the engine hood while the engine hood and the paint spray -
guns 140a throu~h 140d remain spaced a constant di3tance
from each other.
Similarly, while the paint spray guns 140a through
140d are being spaced uniformly from the surface of the
vehicle body 14 and directed perpendicularly to the vehicle
body surface, strips of paint are coated on the vehicle
body surface as the upper painting mechanism 36 moves along
painting lines c, d, e and f. Finally, the turning motor
100 is driven to hold the paint spray guns 140a through
140d facing perpendicularly to the rear end of the vehicle
body 14. Then, while the lifting/lowering motor 92 is
being driven to lower the paint spray guns 140a through
140d in the direction of the arrow A, the rear end of the
vehicle body 14 is coated along a painting line ~.
The lateral sides of the vehicle body 14 are painted
by the lefthand and righthand side painting mechanisms 38,
40 as follows:
When a control signal is issued from the control unit
184, the servoamplifier 200a (FIG;. 9~ actuates the
servova~ve 198a to enable fluid under pressure from the
hydraulic unit 196 to drive the transport motor 66 through
the servovalve 198a. As a result, the lefthand and
righthand side painting mechanisms 38, 40 run along the
rails 34a, 34b in the direction of the arrow C (FIG. 3),
-36-
. , , .
-" 132770~
while paint sprays are discharged from the paint spray
guns 182a through 182d to coat the lateral sides of the
vehicle body 14. The paint spray guns 182a through 182d
are spaced a prescribed distance from the vehicle body 14,
so that strips of paint are coated on the vehicle body
side~ without interfering with each other.
The amount of displacement of the lefthand and right-
hand side painting mechanisms 38, 40 in the direction of
the arrow C is detected by the potentiometer 204a through
the speed reducer 202. The distance between each of the
sides of the vehicle body 14 and the paint spray guns 182a
through 182d is controlled by the horizontally moving
cylinder 152. More specifically, when a control signal is
generated by the control unit 184, the servoamplifier 200b
operates the servovalve 184b to enable the latter to apply
a fluid under pre~sure for driving the cylinder 152.
Therefore, the paint spray guns 182a through 182d coupled
by the gun arm 178 to the holder 174 are moved in the
direction of the arrow E or F (FIG. 7). The amount of
movement of the paint spray guns 182a through 182d is
detected by the potentiometer 204b, which then applies a
prescribed po~itional signal to the servoamplifier 200b
that controls the cylinder 152 through the servovalve
198b. Consequentlyr the paint spray guns 182a through 182d
are displaced in the direction of the arrow E or F as the
lefthand and righthand side painting mechanisms 38, 40 move
in the direction of the arrow C for thereby keeping the
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1327700
side of the vehicle body 14 and the paint spray guns 182a
through 182d spaced a constant distance. Therefore, a
paint coat of uniform thickness can be applied to the sides
of the vehicle body 14.
The lefthand and righthand side painting
mechanisms 38, 40 are moved while they are being spaced a
given distance from the upper painting mechanism 36.
Specifically, as shwon in FIG. 3, the paint spray gun 140a
(FIG. 4) of the upper painting mechanism 36 and the paint
spray gun 182a of the lefthand side painting mechanism 48
are spaced a distance from each ot-her at all times, whereas
the paint spray gun 140d of the u~per painting mechanism 36
and the paint spray g.un 182a of the righthand side painting
mechanism 48 are spaced a distance from each other at all
times. By moving the painting mechanisms 36, 38, 40 while
keeping them thus spaced from each other, paint sprays
ejected from those paint spray guns which are located most
closely to each other are preve~ted from interfering with
each other. Therefore, the paint coating on the vehicle
body 14 is free from coating irre~ularitles Qr paint runs
and sags w~ich would other~ise re~a~t ro~ inter~crence of
paint sprays~
The vehicle body 14 is thus c~ated with strips of
paint as indicated by the shaded areas in FIG_ 3. The
painting mechanisms 36, 38, 40 are moved to the position
indicated by the two-dot-and-dash lines in FIG. 3.
Then, the shifting cylinder 164 associated with
-38-
? ' ~ ~ ~ t
13277~0
each of the lefthand and righthand side painting mechani~ms
38, 40 is driven. The piston rod 168 of the shifting
cylinder 164 is lowered to cause the joint 162 to move the
guide bar 158 downwardly in the direction o~ the arrow A
(FIG. 7.) As a consequence, the paint spray guns 182a
through 182d are shifted to the two-dot-and-dash-line
position in FIG. 7 by the holder 174 supported on the guide
bar 158.
Thereafter, the servoamplifier 200a responds to a
control signal from the control unit 184 to operate the
servovaive 198a for thereby driving the transport motor 66
with a fluid under pressure from the hydraulic unit 196.
The lefthand and righthand side painting mechanism~ 38, 40
run along the lateral sides of the vehicle body 14 in the
direction of the arrow G while coating the unpainted areas
or strips on the vehicle body sides with paint sprays
e~ected from the paint ~pray guns 182a through 182d. The
painting mechanisms 38, 40 return to the ~olid-line
position shown in FIG. 3, whereupon they are stopped.
On the upper painting mechanism 36, the shifting
cylinder 114 (FIG. 6) in the swing arm 112 i-~ driven to
displace the piston rod 116 thereof in the direction of the
arrow E. Since the end of the piston rod 116 is coupled to
the slide sleeve 122, the slide sleeve 122 is displaced
therewith alang the fixed ~haft 118 disposed around the
piston rod 116. Thus, the paint ~pray guns 1~0a through
140d coupled to the slide sleeve 122 by the horizontal gun
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- !
.~ 1327700
arm 132 are shifted to the two-dot-and-dash-line position
shown in FIG. 6.
~ hen, the transport motor 66, the lifting/lowering motor
g2, and the turning motor 100 are driven to move the upper
painting mechanism 36 along the rail 34a in the direction of
~he arrow G (FIG.3). The unpainted areas or ~trips on the
upper vehicle body surface are coated by the paint spray guns
140a through 140d as they are displaced back along the
painting lings ~ through a until the upper painting mechanism
36 returns to the solid-line position of FIG. 3, whereupon it
is put to a stop. At this time, too, the lefthand and
righthand side painting mechanisms 38, 40 and the upper
painting mechanism 36 are spaced from each other to avoid
mutual interference of paint sprays discharged therefrom.
After the painting process as above is finished, the
vehicle body 14 is transferred by the conveyor mechanism 24
to the fourth stage lOd where the vehicle body 14 is dried.
In the above embodiment, to prevent the paint sprays from
interfering with each other, the vehicle body 14 is coated in
a strip-shaped pattern while the paint spray guns 140a through
140d are being ~paced from each other and also the paint spray
guns 182a through 182d are being spaced from each other while
coating the vehicle body 14, and thereafter the paint spray
guns 140a through 140d and the paint spray guns 182a through
182d are shifted by
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~` 1327700
the shifting cylinders 114, 164 before the unpainted area~
of the vehicle body 14 are painted. However, as a
modification, the paint spray guns 140a through 140d and
182a through 182d may be disposed as two groups in both
solid-line and two-dot-dash-line position shown in FIGS. 6
and 7, and such two groups of paint cpray gun~ may be
spaced from each other in the direction in which the
painting mechanisms 3b, 38, 40. With such an alternative,
the entire surface of the vehicle body 14 can be painted in
one coating operation.
When changing paint color3 in order to paint a
different vehicle type, the paint spray gun~ 140a through
140d and 182a through 182d are cleaned by the cleaning
devices 336, 338, 340 after a vehicle body 14 has been
painted or before it is painted on the painting line 10.
More specifically, as shown in FIG. 1, the upper paint
~pray gun cleanlng device 336 is directed parallel to the
rail 34b while vehicle bodies 14 are being painted, 90 that
the cleaning device 336 will not obstruct the vehicle body
14 as it is painted. For cleaning the paint spray guns
140a through 140d, the body 344 (FIG. 11) is displaced
vertically upwardly, and thereafter the body 344 is
horizontaliy turned by a non-illustrated drive source until
the rods 346a, 346b are positioned parallel to the
horizontal gun arm 132, for thereby moving the cleaning
tanks 348a through 348d to their prescribed position.
Then, the lifting/lowering motor 92 is driven to
-41-
.
- -
. .
1327700
cause the ball screw 90 to displace the support plate g6 inthe direction of the arrow A (FIG. 6). The paint qpray
guns 140a through 140d are also displaced in the direction
of the arrow A by the swing arm 112 supported by the
support plate 96. At this time, as shown in FIG. 12, the
nozzle 240a of the paint spray gun 140a enters the holes
358a, 358b of the flexible covers 356a, 356b attached to
the base plate 350 of the cleaning tank 348a. Since the
holes 358a, 358b are smaller in diameter than the nozzle
240a and the slits (not shown) of the covers 356a, 356b
which communicate with the holes 358a, 358b do not overlap
each other, the upper end of the chamber 380 in the casing
378 can fully be closed by the nozzle 240a.
A solvent such as a thinner or a mixture of the
solvent and air is e~ected from the nozzle ends 368a
through 368d and 376 through conduits coupled to the
cleaning guns 366a through 366d and 374. As the nozzle
ends 368a through 368d and 376 are directed toward the
central axis of the opening 354, i.e., the nozzle 240a of
the paint spray guns 140a, the solvent or the mixture from
the nozzle ends 368a through 368d and 376 is forcibly
applied against the nozzle 240a for effectively cleaning
the same.
The upper end of the chamber 380 where the nozzle 240a
enters is closed by the flexible covers 356a, 356b. Thus,
the solvent or the mixture discharged from the cleaning
guns 366a through 366d and 374 iq prevented from
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13277~
leaking ou~ of the cleaning tank 348a. As a result, any
mist containing a large amount of thinner will not go into
the working space and hence will not adversely affect the
health of the worker~.
While the nozzle 240a of the paint spray gun 140a is
being cleaned, a paint solution containing the fluid
e~ected from the cleaning gun~ 366a through 366d and 374,
i.e., a mixture of a drain solution and a mist is
discharged thr~ugh the outlet 382 at the lower end of the
casing 378 and also through the conduits 384, 386 into the
separation tank 388 where the mixture is separated into the
drain and the mist. The mist is fed via the conduit 390
into a drain processing unit (not shown), and the drain i~
delivered by the pump 393 into a drain processing unit (not
shown). Therefore~ no drain/mist flows into the working
space, and a good environment is maintained in the working
space.
While the cleaning process for the paint spray gun
140a has been dascribed in detail, the other paint spray
guns 140b throuqh 140d are cleaned in the same manner.
The paint spray gun~ 182a through 182d of the side
painting mechani~ms 38, 40 are cleaned as followss
In the 3ide paint spray gun cleaning device 338, the
cylinders 302a, 302b (FIG. 11) are operated to displace the
piston rods 304a, 304b horizontally to position the
cleaning tanks 300a, 300c supported on the piston rods
-43-
... ~, . . .. .
. .
- 13277~0
304a, 304b in horizontal alignment with the respective paint
spray guns 182a, 182c. The nozzle ends of the paint spray
guns 182a, 182b, 182d are horizontally oriented and
positioned, and the gun arN 178 is swung from the side of the
vehicle body 14 toward the side paint spray gun cleaning
device 338 until the paint spray guns 182a through 182d
confront the cleaning tanks 300a through 300d, respectively.
The lefthand side painting mechanism 38 is then displaced
along the rail 34a toward the cleaning device 338, whereupon
the nozzle ends of the paint spray guns 182a through 182d are
inserted into the respective cleaning tanks 300a through 300d.
The nozzle ends of the paint spray guns 182a through 182d are
now cleaned in the cleaning tanks 182a through 182d in the
same manner as that in which the paint spray gun 140a is
cleaned in the cleaning tank 348a.
The paint spray guns 182a through 182d of the righthand
side painting mechanism 40 are similarly automatically cleaned
by the side paint spray gun cleaning device 340.
~ peration of the painting apparatus of the invention will
be described in greater detail. FIG. 14 is a flowchart of
operation of the conveyor mechanism and the controllers of the
painting control system 400 shown in FIG. 2.
14-A indicates a sequence or flow of operation of
-44-
--` 1327700
the vehicle body conveyor mechanism 24, 14-B a sequence of
operation of the line master controller 410, 14-C a
~equence of operation of the stage master controllers 412a
thxough 412c, 14-D a sequence of operation of the
opening/closing controllers 420, 430, 14-E a sequence of
operation of the painting robot controllers 422, 432, 442,
and 14F a sequence of operation of the painting controllers
424, 434, 44~.
When a vehicle body 14 to be coated is set on the
conveyor mechanism 24 and the line master controller 410
issues an automatic start signal for the painting line, the
conveyor mechanism 24 is initialized in position and
started (14-A). In synchronism with the starting of the
conveyor mechanism 24, the line master controller 410
shifts vehicle type and paint color data to a transmission
register and then transfers the data to and sets the data
in the stage ma~ter controllers 412a through 412c (14-B,
14-C). As the conveyor mechanism 24 advances and the
vehicle body 14 reaches a desired one of the painting
stages lOa through lOc, the line master controller 410
issues a start command to a corresponding one of the stage
master controllers 412a through 412c. Based on the start
command, the ~tage master controllers 412a through 412c
transfer the vehicle type data to the associated
opening/closinq controllers 420, 430 and the painting robot
controllers 422, 432, 442, and al~o transfer the paint
color data to the painting controller~ 424 through 444.
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-" 1327700
The data items are read by the opening/closing controllers,
the painting robot controllers, and the painting
controllers. The ~tage master controllers 412a through
412c issue a start command to the opening/closing
controllers 420, 430, the painting robot controllers 422,
432, 442, and the painting controllers 424 through 444.
In response to the vehicle type data and the start
command, the opening/closing controllers 420, 430 are
readied for opening operation and wait for the completion
of the vehicle body positioning (14-D). Similarly, in
respon~e to the vehicle type data and the start command,
the painting robot controllers 422, 432, 444 wait for
painting operation and also for opening of the
opening/closing mechanisms 20, 22, 32a, 32b in the painting
stages lOb, lOc (14-E).
When tAe vehicle body 14 i9 positioned in one of the
painting stages lOa through lOc upon further advance of the
conveyor mechan$3m 24, the line master controller 410
confirms the vehicle body positioning, and applies a
positioning confirmation signal to the stage master
controllers 412a through 412c (14-A, 14-~).
` In.response to the positioning confirmation signal,
the stage master controllers 412a through 412c control the
opening/closing controllers 420, 430, to open the
opening/closing mechanism~ 20, 22 or 32a, 32b, to confirm
the completion of their opening, and to issue an opening
completion signal to the painting robot controller~
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422, 432, 442 (14-D, 14-E).
In response to the opening completion signal from the
opening/closing controllers 420, 430, the painting robot
controllers 422, 432, 442 move the corresponding painting
mechanisms 18a through 18d, 28a, 28b or 36, 38, 40 to their
painting position, and issue a paint and painting condition
command to the painting controllers 424 through 444 (14-E, 14-
F). When the paint and painting condition command is
received, the painting controllers 424 through 444 select the
indicated paint and painting condition, and control the
painting mechanisms 18a through 18d, 28a, 28b or 36, 38, 40
to effect painting operation.
Upon arrival of the painting mechanisms 18a through 18d,
28a, 28b or 36, 38, 40 at a painting completion pasition, the
painting robot controllers 422, 432, 442 transmit a paint
completion signal to the painting controllers 424 through 444,
which then turns off the paint (14-E, 14-F). At the same
time, the painting robot controllers 422, 432, 442 command
closing of the opening/closing mechanisms 20, 22 or 32a, 32b
corresponding to the opening/closing controllers 420, 430 (14-
E).
In response to the closing command from the painting
robot controllers 422, 432, 442, the opening/closing
controllers 420, 430 close the corresponding opening/closing
mechanisms 20, 22 or 32a, 32b (14-D).
Upon completion of the closing operation, the
opening/closing controllers 422, 432, 442 return the
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corresponding opening/closing mechanisms 20, 22 or 32a, 32b
to their original position and transmit a returning
completion signal to the stage master controllers 412a
through 412c, which then return all of the corresponding
painting stages lOa through lOc to the original position
(14-D, 14-C).
When all of the painting stages lOa through lOc
return to their original position, the line master
controller 410 returns the entire painting line to the
original position, whereupon the painting of the vehicle
body 14 is finished (14-B).
FIGS. 15 through 19 show another embodiment of
t~e present invention. In this embodiment, as shown,
painting mechanisms are displaceable in a transverse
dire~tion of an automotive vehicle body 14, so that the
painting operation can be effected in a short p-eriod of
time for highly efficient operation of the overall painting
process.
FIG. 15 illustrates a painting apparatus 500
m~ricing first rails 514a, 514b disposed on opposite
sidæ~ ~ a vehicle co~veyQr mechanism 512 extendiog along a
painting li~e., firYt painting mechanisms 516a, 516b ~ova~le
~Long t~e ~irst rails 514a, 514b, respectively, seco~d
rails 518a, 518b spaced from the first rails 514a, 514b,
respectively, and a second painting mechanism 520 movable
back and forth along the second rails 518a, 518b. An
automotive vehicle body 522 has its longitudinal direction
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.
-" 13277~0
substantially perpendicular to the conveying direction
(indicated by the arrows). The vehicle body 522 has a
front portion 524 and a rear portion 526 which are painted
by the first painting mechanisms 516a, 516b, respectLvely,
and lateral side-c 528, 530 and an upper portion which are
painted by the second painting mechanism 520.
The first painting mechanisms 516a, 516b and the
second painting mechanism 520 are transported along the
first rails 514a, 514b and the second rails 518a, 518b by
basically the same transport means as that of the previous
embodiment. Therefore, such tran~port means will not be
described below.
The first painting mechanisms 516a, 516b have
horizontally directed paint spray guns 550a, 550b which are
preferably displaceable in vertical directions (indicated
by the arrows A, D in FIGS. 16 and 17) and in horizontal
directions (indicated by the arrows E, F in FIG. 16) by
means of actuators mounted in the fir~t painting mechanisms
516a, 516b.
The second painting mechani3m 520 is described below.
The second painting mechanism 520 comprises a pair of
vertical mobile posts and an arm 572 movably mounted at its
opposite ends on the post~. Paint spray guns 574a through
574i are supported on the arm 572. Since the paint spray
guns 574a though 574i are identical in construction, only
the paint spray gun 574a will be described in detail.
An attachment plate 576a extending vertically
-49-
1 ~2~7~
downwardly is secured at one end to the arm 572, and a
lifting/lowering cylinder 578a is mounted on the attachment
plate 576a. The lifting/lowering cylinder 578a has a
downwardly extending piston rod 580a to which there i8
fixed an attachment member 584a attached to the lower end
of a bracket 582a. The bracket 582a accommodates therein a
swinging cylinder 586a having a piston rod 588a extending
downwardly and projecting a prescribed length from the
lower end of the bracket 582a. A rod 590a has one end
fixed to thQ lower end of the bracket 582a parallel to the
pistc~ rod 588a, with a swing plate 592a being swingably
attached to the other end of the rod 590a. The paint spray
gun 574a is ~ounted on the distal end of the swing plate
592a. The piston rod 588a has its distal end coupled to a
joint 594a projecting laterally from the swing plate 592a.
The paint spray gun 574a is of a basic
construction as described above. The other Faint spray
guns 574a through 574i are indentical in structure, and
their identical components are denoted by identical
reference nl~erals with suffixes b through i.
The paint spray guns 574e, 574f serve to paint
the uppermost pQstion of a roof 532 of the vehicle body
522, a-nd m~y not be vertically movable with res~ect to the
arm 572. T~erefore, the swinging cylinders 586e, 586f
thereof may be directly mounted on the attachment plates
576e, 576f, respectively.
The painting apparatus of the ~econd embodiment
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. ' :
13277~
operates and is advantageous as follows:
As shown in FIG . 15, the first painting
mechanisms 516a, .516b are positioned on one end of the
first rails 514a, 514b, and the second painting mechanism
520 is positioned on one end of the second rails 518a,
518b, with the paint spray guns 574a through 574i being
directed substantially perpendicularly to a lefthand side
528 of the vehicle body 522.
The vehicle body 522 is then moved transversely
in the directio~ of the arrow by the conveyor mechanism 512
until the vehicle body`522 is positioned between the first
and second rails 514a, 514b whereupon the vehicle body SZ2
is stopped. Paint sprays are then ejected from the paint
spray guns 550a, 550b of the rirst painting mechanisms
516a, 516b:, during which time the first painting mechanisms
516a, 516b are moved along the first rails 514a, 514b to
their opposi~e end.
More specifically, the first painting mechanisms
516a, 516b are moved in tbe d~rection opposite to the
direction of the arrow by mea~s of the transport means on
the Lower ends Qf the first paintln~ mechanisms 516a, 516b.
Thus, the paint s~ray guns 550a, 550b are moved in the
directi~n oppc~ite to t-he direction of the arrow while
ejecti~g pai~t ~pray~ to coat the front and rear portions
524, 526 ~f the vehicle b~dy 5~.2.
hfter the front and rear portions 524, 526 of the
vehicle body 522 have been painted, the vehicle body 522 is
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~ 1327700
transferred in the direction of the arrow by the conveyor
mechanism 512 and then stopped when it reaches a position
between the second rails 518a, 518b. The second painting
mechanism 520 is then operated to apply paint sprays from
the paint spray guns 574a through 574i which are directed
substantially perpendicularly to lefthand side, upper, and
righthand side portions S28, 532, 530 of the vehicle body
S22 and are spaced at prescribed intervals from each other,
as shown in FIG. 18.
More specifically, for coating the lefthand side
portion 528 of the vehicle body S22 with the second
painting mechanism 520, the lifting/lowering motor 92 is
driven to move the paint spray guns 574a through 574i from
a position Pl to a position P2. The ball screw 90 coupled
to the lifting/lowering motor 92 is rotated about its own
axis, causing the support plate 96 to lift the arm 572 in
the direction of the arrow D. At this time, the turning
motor 100 is also driven to rotate the gear 104 supported
on its shaft for enabling the gear 100 meshing with the
gear 104 to turn the arm 572 in the direction of the arrow
, ~
B.
Thexefore, the paint spray guns 574a through 574i
mounted on the arm 572 are directed perpendicularly to the
lefthand side 52~ of the vehicle body 522. If required,
the pinion 70 i9 rotated by the transport motor 66 to cause
the rack 52 to move the casing along the rail bracket in a
prescribed direction. As a result, the paint spray guns
1327700
574a through 574i can be spaced a constant distance from
the lefthand side 548 of the vehicle body 522, so that the
paint can uniformly be applied from the paint spray guns
574a through 574i to the lefthand side 528 of the vehicle
body 522.
After the lefthand side 528 of the vehicle body
522 has been painted, the gear 104 is rotated by the
turning motor 100 to enable the gear 104 to rotate the arm
572 in the direction of the arrow B for thereby orienting
the paint spray guns 574a through 574i do~nwardly. At this
time, the paint spray guns 574a through 574i are
positionally adjusted so that they are directed
substantially perpendicularly to and spaced a desired
distance from the englne hood, roof, and trunk lid of the
vehicle body 522.
Mare specifically, as ill~ustrated in FIG. 17,
when the lifting/lowering cylind~r 578a is driven to
displace the piston rod 580a in the directi~n of the arrow
A, the bracket 582a coupled to the piston rod 580a is
lowered. Therefore, the paint spray gun 574a supported by
the pi~ton rQd 588a of the swinging cylinder 586a disposed
in the bracket 582a a~d also by the rod 590a is displaced
in the direction of the arrow A. The lifting/lowering
cylinder 578a is inactivated wben the paint spray gun 574a
reaches a position which is spaced a given distance from
the engine hood. Where the surface of the engine hood
which faces the paint spray gun 574a is slanted, the
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13~770~
swinging cylinder 586a is driven to displace the piston rod
588a in a desired direction. The swing plate S92a is now
angularly moved in the direction of the arrow by the joint
594a coupled to the pistonirod 588a until the paint spray
gun 574a is oriented substantially perpendicularly to the
engine hood surface, whereupon the swinging cylinder 586a
is stopped.
The paint spray guns 574b, 574c are similarly
angularly moved to meet the shape of the engine hood and
positioned at a desired spacing therefrom by driving the
lifting/lowering cylinders 578b, 578c and the swinging
cylinders 586b, 586c.
The paint spray guns 574d through 574g for
paining the vehicle body roof are swung to meet the shape
of the roof by driving the swinging cylinders 586d through
586g. Durding this time, at lea-st the lifting/lowering
cylinders 578d, 578g are driven to displace the piston rods
580d, 580g in the direction of the arrow A for thereby
positioning the paint spray gu~s 574d through 574g with
respect to the roof.
The paint spray guns 574h, 574i for painting the
trunk lid are positioned a d~sired distance rom the trunk
lid by driving t~he lifting/lowering cylinders 578h, 578i
and the swinging cylinders 586h, 586i.
In this manner, the paint spray guns 574a through
574i are positioned with respect to the engine hood, roof,
and trunk lid of the vehicle body 522. The pinion 70 is
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1327700
rotated by the transport motor 66 to cause the rack 52 tomove the casings in ~he direction opposite to the direction
of the arrow. Therefore, the second painting mechanism 520
passes through a position P3 in FIG. 18 while the upper
portion of the vehicle body 522 is fully coated by the
paint spray guns 574a through 574i.
After the upper portion of the vehicle body 522
has been painted, the lifting/lowering cylinders 578a
through 578i are driven to displace the paint spray guns
574a through 574i a prescribed distance in the direction of
the arrow D, and the swinging cylinders 586a through 586i
are operated to turn the nozzle ends of the paint spray
guns 574a through 574i a desired a~gle in the direction of
the arrow. The paint spray guns 574a through 574i are ~ow
positioned in a pattern complementary to the configuration
of the righthand side 530 of the vehicle body 522.
Then, the tra~sport motor 66 is actuated to move
the casings in the direction opposite to the direction of
the arrow, while at the same time the turning motor 100 is
driven to rotate the arm 572 in the opposite direction, and
the arm 572 is displaced in the direction of the arrow A by
the lifting/lowering motor 92. Therefore, the paint spray
guns 5i4a through 574i reach a position P4 in FIG. 18 to
start painting the righthand side 530 of the vehicle body
522. The lifting/lowering motor 92 and the turning motor
lO0 are driven to rotate the arm 572 in the prescribed
direction and displace the same in the direction of the
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-- 1327700
arrow A. If necessary, the transport motor 66 is operated
to move the casings in a direction to orient the paint
spray guns 574a through 574i substantially perpendicularly
to the righthand side 530 of the vehicle body 522 and also
to space them a desired distance from the righthand side
530, which is thereafter painted.
Then, as shown in FIG. 18, the outer panel
surface of the vehicle body 522 is fully coated until the
paint spray guns 574a through 574i reach a position P5,
whereupon the paint sprays from the paint spray guns 57~a
through 574i are cut off. The painted vehicle body 522 is
transferred in the direction of the arrow C by the convey~r
mechanism 512.
At this time, a next vehicle body 522 has been
transferred to the position between the first rails 514a,
514b. The front and rear portions 524, 526 of the next
vehicle body 522 are then coated by the first painti~g
mechanisms 516a, 516b. Before the new vehicle body 522 is
painted by the first painting mechanisms 516a, 516b, the
transport motor 66 is driven to position the casings as
. / .
shown in FIG. 15, and the lifting/lowering motor 92 and the
.
turning motor 100 are operated to direct the paint spray
gun 574a througb 574i substantially perpendicularly to the
lefthand side 528 of the vehicle body 522.
With the present invention, it is po~sible to
paint the vehicle body 522 in a short period of time, and a
uniform and sightly paint coat can be applied to the
13277~
overall outer panel surface of the vehicle body 522.
As described above, the vehicle body 522 is
delivered by the conveyor mechanism 512 into the painting
apparatus 500 while the sides 528, 530 of the vehicle body
522 extend in a direction substantially normal to the
direction in which the vehicle body 522 is transferred (in
the direction of the arrow). Therefore, as shown in FIG.
15, the first painting mechanisms 516a, 516b for painting
the front and rear portions 524, 526 of the vebicle body
522 are moved only a distance S1 that is slightly longer
than the width of the vehicle body 522 (at the front and
rear portions 524, 526) wbile painting the front and rear
portions 524, 526. The second painting mechanism 520 for
coating the sides 528, 530 and the top 532 of the vehicle
body 522 is moved a distance S2 which is equal to the sum
of the width of the vehicle body 522 and an additional
distance.
Therefore, the distances that the painting
mechanisms 516a, 516b, 520 must move are smaller than those
of the painting mechanisms of the painting apparatus in
whicb the lateral sides of a vehicle body would extend in
the direction of delivery of the vehicle body, so that the
vehicle body 522 can be coated in a short period of time.
Consequently, the painting line with the painting apparatu~
500 incorporated therein is rendered highly efficient, and
can be shortened in its overall length.
The paint spray guns 574a through 574i of the
- -57-
-- 1327700
second painting mechanism 520 are angularly movable and
vertically movable by the arm 572, and are also
displaceable into a pattern complementary to the shaft of
the vehicle body 522. Thus, paint sprays can be ejected
from the paint spray guns 574a through 574i while they are
being directed substantially perpendicularly to and spaced
a prescribed distance from the sides 538, 530 and the top
532 of the vehicle body 522. The paint sprays can
therefore be uniformly applied against the overall surface
of the vehicle body 522 to form a sightly paint coat
thereon.
FIG. 19 illustrates a painting apparatus
according still another embodiment. Those p~rts which are
identical to those of the preceding embodiment are denoted
by identical reference characters, and will not be
described in detail.
A painting apparatus 590 according to this
embodiment includas a pair of rails 592a, 592b vertically
disposed on opposite sides of the conveyor mechanism 512.
A set of casings is movably mounted on the rail 592a,
whereas anoth~e set of casings is movably mounted on the
other rail 592b.
A vehicle body 522 is transferred by the conveyor
mechanisms 512 in the direction of the arrow, and then
stopped when it has reached a painting position in the
painting apparatus 590. The casings of the first painting
mechanisms 516a, 516b are moved along the rail brackets of
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- 1327700
the rails 592a, 592b in the direction opposite to the
direction of the arrow, during which time paint sprays are
ejected from the paint spray guns 550a, 550b to coat the
front and rear portions 524, 526 of the vehicle body 522.
Then, the second painting mechanism 520 is
operated to coat the sides 528, 530 and the top 532 of the
vehicle body 522 in the se~uence described above. More
specifically, the arm 572 is vertically moved and angularly
moved, and the casings are displaced in a prescribed
direction along the rail brackets. The paint spray guns
574a through 574i are therefore directed substantially
perpendicularly to and spaced a desired distance from the
lefthand side, upper, and righthand side portions 528, 532,
530 of the vehicle body 522, which are then uniformly
painted.
The painting apparatus 590 of this embodiment is
advantageous in that since the painting mechanisms 516a,
516b, 520 are mounted on the pair of rails 592a, 592b, the
space taken up by the painting mechanism 590 is much
smaller.
FIGS. 20 through 23 illustrate a further
embodiment of the present invention. In this embodiment,
holder mechanisms are employed for smoothl~ ho}ding hoses,
cables, and the like which supply driving mediums such as
pneumatic pressure, hydraulic pressure, electric power
while the painting mechanisms are moved. Those components
which are identical to those of the previous embodiments
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- . - .
, : -
: ~ :
`
`-` 1327700
are designated by identical reference characters.
As shown in FIG. 20, holder mechanisms 600a, 600b
are disposed outside of the rails.
The holder ~echanism 600a includes a base 602a
coupled to the rail bracket 42 of the rail parallel
thereto. A box-shaped casing 604a is vertically mounted on
the base 602a and has an opening 606a defined in its side
panel facing the rail. As illustrated in FIG. 21, first
and second racks 608a, 608b have ends secured substantially
centrally to the base 602a in confronting relation to each
other. The other end of the first rack 608a is fixed to
the upper painting mechanism 36, whereas the other end of
the seond rack 608b is fixed to the lefthand side paintin~
mechanism 38.
The holder mechanism 600b includes a base 602b
coupled to the rail bracket 42 of the rail parallel
thereto. A casing 604b having an opening 606b is
vertically mounted on the base 602b. A third rack 608c has
an end secured to one end of the base 602b. The other end
of the third rack 608c is supported on the righthand side
painting mechanism 40.
Since the first through third racks 608a - 608c
are identical in construction to each other, only the first
rack 608a will be described in detail.
As shown in FIGS. 22 and 23, the first rack 608a
includes a pair of parallel elongate chains 610a, 610b
comprising a plurality of plate-like links 612a, 612b with
-60-
-~
- .~
`` 132770D
their ends angulary movably coupled. The links 612a, 612b
in confronting pairs, for example, alternately have central
bolt insertion holes 614a, 614b and 614c, 614d. A first
partition rod 616 extends through the holes 614a, 614c, and
has externally threaded ends 618a, 618b. A first guide
cylinder 620 having a prescribed length is rotatably fitted
over the first rod 616, and extends through ends of support
plates 622a, 622b disposed outwardly of the first cylinder
620. Cylindrical spacers 624a, 629b are interposed between
the support plates 622a, 622b and the links 612a, 612b.
The first rod 616 is loosely fitted in the spacers 624a,
624b, and nuts 626a, 626b are threaded over the externally
threaded ends 618a, 618b thereof.
The support plates 622a, 622b are of a
rectangular shape and have holes 628a, 628b defined in one
end and in which the first rod 616 is fitted. The support
plates 622a, 622b have first grooves 630a, 630b spaced a
distance S3 from the holes 628a, 628b and extending
transversely of the support plates 622a, 622b. The support
plates 622a, 622b also have second grooves 632a, 632b
spaced a distance S4 from the first gr~oves 630a, 630b, and
third grooves 634a, 634b spaced a distance S5 from the
second grooves 632a, 632b. The distances S3, S4, S5 are
progressively smaller in the order named.
The support plates 622a, 622b have threaded holes
636a, 363b positioned between the grooves 632a, 632b and
the grooves 634a, 634b, and threaded holes 638a, 638b at
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1327700
ends near the third grooves 634a, 634b. Plate-like
stoppers 640a, 640b are angularly movably mounted at one
end on the support plates 622a, 622b by means of pins 642a,
642b.
The other ends of the stoppers 640a, 640b have
bolt insertion holes 644a, 644b through which bolts 646a,
646b are inserted threadedly into the threaded holes 638a,
638b. Thus, the stoppers 640a, 640b are mounted on the
support plates 622a, 622b parallel to the longitudinal
direction thereof.
Second through fourth partition rods 648a through
648c are fitted endwise in the first grooves 630a, 630b
through the third grooves 634a, 634b. Second through
fourth cylinders 650a through 650c, which are similar to
the first cylinder 620, are rotatably fitted over the
second through fourth rods 648a through 648c, respectively.
Therefore, the first and second cylinders 620, 650a, the
second and third cylinders 650a, 650b, and the third and
fourth cylinders 650b, 650c define first through fourth
storage ~paces or areas 652a through 652c, respectively,
which are progressively smaller in width.
The second through fourth rods 648a through 648c
are mounted on the support plates 622a, 622b through the
stoppers 640a, 640b, and cylindrical spacers 654a, 654b are
disposed between the support plates 622a, 622b and the
links 612a, 612b. ~olts 656a, 656b are inserted through
the holes 614b, 614d of the links 612a, 612b and also
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132770~
through the spacers 654a, 654b ~hreaded into the threaded
holes 638a, 638b, thereby fastening the support plates
622a, 622b to the respective links 612a, 612b.
The ~irst rack 608a accommodates hoses and cables
for driving the upper painting mechanism 36 and hoses for
supplying the paint to the paint spray guns 140a through
140d of the upper painting mechanism 36. More
specifically, the hoses are divided into a first hose group
658a of larger diameter, a second hose group 658b of medium
diameter, and a third hose group 658c of smaller diameter.
The first hose group 658a is housed in the first storage
space 652a, the second hose group 658b is housed in the
second storage space 652b, and the third hose group 658c is
housed in the third storage space 652c. One end of the
chains 610a, 610b is fixed to the base 662 through
attachments 660, and the chains 610a, 610b are bent at
intermediate portions thereof. The other ends of the
chains 610a, 610b are coupled to attachment bases 662 fixed
to the plate 60 of the upper painting mechanism 36. The
first through third hose groups 658a - 658c are
positionally selected such that the first hose group 658a
of larger diameter are bent in an outermost position at the
bent portion~ of the chains 610a, 610b.
Operation and advantages of the holder mechanisms
600a, 600b will be described below.
When the upper painting mechanism and the side
painting mechanisms are displaced, the spray nozzles
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,
_~ 1327700
mounted on the painting mechanisms, the first hose group
658a, the second hose group 658b, and the third hose group
658c which are coupled to the drive sources and other
sources are extended. Upon movement of the painting
mechanisms, the cables and hoses in the first through third
hose groups induce rotation of the first, second, third,
and fourth cylinders 620, 650a - 650c. In this embodiment,
the support plates 622a, 622b are disposed between the
chains 610a, 610b, and the first rod 616 and the second
through fourth rods 648a - 648c are mounted on the support
plates 622a, 622b, thus defining the first through third
storage spaces 652a - 652c which are divided from each
other. Since the cables and hose-~ are divided into the
first through third hose grobps 658a - 658c according to
their diameter, and the first through third hose groups
658a - 658c are stored respectively in the first through
third storage spaces 652a - 652c, the hose groups 658a
thruogh 658c can smoothly be displaced without the danger
of damage to the hoses which would otherwise be caused by
overlapping of the hoses.
More specifically, the cylinders 620, 650a
through 650c are rotatably fitted over the rods 616, 648a
through 64ac, respectively. As shown in FIG. 21, when the
end of the first rack 608a is displaced with the upper
painting mechanism 36 along the rail 36a and the bent
portions of the chains 610a, 610b are successively moved
while the links 612a, 612b are being relatively angularly
-64-
` ;-~
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,~ 13277Qo
moved, the hose groups 658a through 658c are not
frictionally moved against the outer peripheries of the
cylinders 620, 650a through 650c. Therefore, the hoses of
the hose groups 658a through 658c will not be entangled
even if the number of those hoses is considerably large,
and can also be prevented from moving frictionally with
respect to other parts. As a result, any wear or damage to
the hose groups 658a - 658c can be reduced as much as
possible. The hose groups 65aa - 658c can be used for a
long period of time, resulting in a highly economical
arrangement. As the hose groups 658a - 658c need to be
replaced less frequently, the maintenance procedure is
simplified, putting a less burden on the workers, and the
overall painting process can easily be automated.
For servicing the hose groups 658a through 658c,
the bolts 656a, 656b are first removed from the threaded
holes 636a, 636b, and the stoppers 640a, 640b are swung
about the pins 642a, 642b. Then, the rods 648a through
648c are removed from the grooves 630a, 630b; 632a, 632b:
634a, 634b of the support plates 622a, 622b. Consequently,
the hose groups 658a through 658b can be handled with
utmost ease.
According to the present invention, as described
above~ a painting line has a conveyor mechanism for
conveying an object such a~ a vehicle body to be painted
and a plurality of painting s~ages disposed for painting
different areas of the object, and the overall painting
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` 1327700
line and the painting stages are controlled by a line
master controller, stage master controllers, and working
component controllers. Command information indicative of a
vehicle type and a paint color is transferred between these
controllers in synchronism with the timing of operation of
the conveyor mechanism. Therefore, computers of the
respective controllers may be of a relatively small
procesing capability for efficient control. When an
operation sequence (processing program) is to be changed
due to changing of vehicle types, the number of vehicles to
be produced, or paint colors~ it is not necessary to change
the entire processing program, but only the operation
sequence for those controllers which are involved in such a
change needs to be modified. Accordingly, the operation
sequence can be modified in a relatively small number of
steps, so that the painting control system can easily adapt
itself to modifications such as a vehicle type change.
With the arrangement of the invention,
furthermore, the lateral sides and top of the object are
painted by first, second, and third painting mechanisms
which can travel independently along the object. By
controlling the first and second painting mechanisms which
paint the sides, respectively, of the object, and the third
painting mechanism which paints the t~p of the object so
that the e mechanisms will run in mutually spaced-apart
relationship, paint sprays are prevented from interfering
with each other between the side~ and the top of the `
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object, so that paint defects such as paint coat
irregularties and/or paint runs and sags will not be
caused. Since the first, second, and third painting
mec~anisms can be controlled independently so that
discharged paint sprays will not interfere with each other,
a paint coat can be applied highly accurately dependent on
the configuration of the object easily and in a small
number of painting steps.
Paint spraying means are moved along the object
by the first painting mechanism and spaced a constant
distance from the surface of the object upon movement of
the second painting mechanism. The paint spraying means
are also directed substantially perpendicularly to the
surface of the object by turning means. Thus, an object
having curved surfaces can automatically be painted with
high accuracy. Where an outer panel surface of an
automotive vehicle body is to be painted, the front and
rear ends thereof are not required to be manually painted
or another independent paining mechanism, as has been the
case with the conventional painting apparatus. Therefore,
vehicle bodies can be coated with paint in a smaller number
of steps and within a shorter period of time.
The painting mechanisms are moved reciprocally,
and the paint spraying means thereon are postionally
shifted on forward and backward strokes of the painting
mechanisms. ThiS allows a more uniform paint coat on the
vehicle body, and also an effective use of the paint, with
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the consequence that a sightly paint coat can be obtained
economically.
According to the present invention, moreover,
cover members are provided to prevent paint droplets or
dust particles from dropping on the object or the path of
the paint mechanisms. Accordingly, paint defects such dust
deposits are not produced on the coated surface, and hence
a sightly smooth paint coat can be produced. The painting
process can automatically and efficiently be effected, and
the entire production line can easily be rendered highly
efficient. The painting mechanisms can also be cleaned
simply by cleaning devices.
Although certain preferred embodiments have been
shown and de~cribed, it should be understood that many
changes and modifications may be made therein without
departing from the scope of the appended claims.
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