Note: Descriptions are shown in the official language in which they were submitted.
~331
~OBOTIZE~ }IA~DLI~G DEVICE A~'D SHEET ME~AL BENl)ING SYSTEM
FBA~URI~G THE SA~tE
The present irvention relates to a robotized, numerical
control handling device, especially suitable for handling
different-sized metal sheets for bending. In particular,
the present invention relates to a handling device suitab]e
for use as ~n integral p~rt of an automated sheet metal
bendin~ pre.ss system, and to the bendin6 system as a
whole.
A~l kno~n handling devices present a physicsl structure
poorly suited to handling metal sheets varying consider-
ably in size. The reason for this is that they usually
comprise a single extendable rotary arm to which is fitted
a frame having a number of pick-up devices, usually mag-
netic (magnets) or pneumatic (suckers). ~landling devices
of the aforementioned type present a number of drawbacks:
performance is limited by the said frame; the device it-
self is hi~hly cumbersome; and the pick-up member must
be changed for handlin6 different-sized sheets.
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The aim of the present invention is to provide a handling device that obviates or
mitigates the above disadvantages. According to one aspect of the present
invention there is provided a bending press system, comprising:
a bending press provided with a punch and a die extended in the X-axis
direction, the punch and the die cooperating with each other for effecting a
bending operation on a sheet workpiece provided therebetween;
a robotized handling device located in front of the punch and the die, for
providing the workpiece between the punch and the die, the robotized handling
device being adapted to be movable in the ~-axis direction while gripping the :
sheet wor~iece;
a lateral gauge means including a linear transducer having a relatively
long measuring range, provided on a frame of the bending press, for detecting :~
the fact that the sheet workpiece is positioned at a predetermined position in the ;
x-axis direction; .
means for detecting a distance through which the robotized handling
device is moved in the X-axis direction; and
control means connected to the lateral gauge means and lhe distance
moved detection means, for controlling the movement of the robotized handling ~ :
device, the control means calculating the position int he X-axis direction of the
workpiece, based upon signals from the lateral gauge means and the distance ~ ~ ~
moved detection means, and controlling the robotized handling device so as to j~:
position the sheet workpiece at a predetermined position in the X-axis directionwith respect to the punch and the die.
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~ 3 ~ ~ 3 3 1 9 ~ 3
A non-limitin6 embodiment of ~he present invention wi]l
be described by way of example, with reference to the
accompanying drawings, in which : ~
5 Fig.l shows a view in perspective ~f a sheet metal ::
bend;ng system including a handling device. ~ :
Fig.s 2 and 3 sho~ a larger-scale, partially-sectiored ~;
~0 elevatio~ and plan vieh res~ectively of a detail on the
Fi6.1 de~ice;
Fig.4 shows a side vie~ of the Fig.l device and system;
Fig.s 5~ ~, 7, 8 and 9 show schematic operatin~ dia~rams
of the Fig.l device.
~umber I in Fig.s I to 4 indica~es an automated system
for bendin6 metal sheets 2, particularly, thou~h not ex-
clusively, for producing boxes 3. Sys~em I comprises a
bendino press 4 of any known type; a robotized handlin~
device 5 controlled by a known, e.~. microprocessor, elec-
tronic system 6; a store 7 for sheets 2; and an unloadingand transfer device 8 for finished boxes 3. Press 4 com-
prises a punch 9 and a die ~0, arran~e~ facing and paral-
lel with each other, and desi~ned to mflte in suoh a man-
ner as to bend a sheet 2 placed between the said punch
9 and ~ie 10 (Fig.s 6 an~ 7) along a straight axis C
(Fi~.5) parallel with the lon~itudinal axis of press 49
and hereinafter referred to also as the "bend axis".
~ehind bend axis C in relation to device 5, and opposite
the said device 5, press 4 also presents a mobile, nume-
rical control back gau~e 11 of substantially known type,
~ ':
33~ 9
,,; ~ .controlled by system 6 or simi]ar, and fitted integra]
with press 4 for cooperat-ing h~ittl and determinin~ the po-
sition of sheet 2.
Back gauge 1~ presents at least one pair of linear
position transducers 12 of any known type (potentiometer,
optical sca]e, etc.) having a relatively long measuring
range (measurable in centimet.res) and designed to coope-
rate with sheet 2 being handled by device 5, for detecting
the position of the said sheet 2 in relation to bend axis
IU C, and consequently supplying system 6, e.g. over line
13, with a control signal enabling system 6 to correct
the posit.ion of sheet 2 by appropriately controlling de-
vice 5. Also , the said
device 5 is mounted directly on and integral with press
15. 4, in pclrt.icular, on a bed element. 14 of the same, paral-
lel with axis C, so as to provide for the necessary struc-
tural rigidity of device ; by exploitin~ the weight of
press 4 itself. Depending on the type of press 4 (mobile
punch or moble die), element 14 ma~ form part of the bed
:,: .: :. ~:
on ~ress 4, in which case device 5 is fixed in relation
to punch 9; or it may form part of a mobile structure sup-
porting die 10, in whic~ case, during operation of press
4, device 5 is raised, together with element 14 and die
1~, tohards fixed punch 9.
Device 5 is a one-armed device comprising a pick-up mem-
ber 15 of any type designed to cooperate with a single
sheet 2 for securing the same coplanar to a pick-up p~ane
tl~rough the said pick-up member 15, and so forcing the
said sheet 2 to travel rigidly integral with and sub-
: ~ : ~: .:
30 stantially coplanar to the said pick-up member 15; a head ~:
:.~' . ;':
. :, ~ :: , :
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1331 953
16 integrally supporting the said pick-up member 15 and
enabling rotation of the same about two perpendicular axes
A and ~ (Fig.s 1, 2 and 3); and supporting members for
head 16, designed to move the same, in relation to a re-
ference system the coordinat.es of which are memorised insystem 6 and which is fixed in relation to axis C, along
three cartesian axes, in particular, along an axis X pa-
rallel with axis C and located a given fixed distance from
the same; and in a plane perpendicu]ar to axis X, in the
example shown, accordin~ to a polar reference Y, Z.
The said members supporting head 16 comprise a straight,
preferably ~-section ~ase 18 secured integral with element
14, with its lon6itudinal axis parallel and coincident
with the said X axis; a known type of powered carriage
l~, e.~-. powered b~ a first step motor 2~ havin~ an en~
coder or other similar position transducer, and designed
to tra~el alon~ base 1~ in the X axis direction; a
strai6ht column 2I supported on a second powered carriage
22 designed to tra~el on the said carriage 19, alon6 a
sector gesr 23, over a curved trajec~ory Y pependicular
to the traveling direct.ion of carriage 19 by virtue of
lyin6 in a plane perpendicular to the said X axis; and
a straight arm 24 secured across the top of column 21,
perpendicular to base l& and to the X axis travc]ing di-
rect.ion of carria~e 1~. Carria6e 22 is powered, for ex-
ample, by a step motor 25 havin~ a respective encoder;
and column 21, in turn, powered, for example, by a further
step mot.or 26 havin~ a respective encoder, travels a]ong
its lon~itudinal axis on carria~e 22, in direction Z per-
pendicular to and lying in the same plane as direction
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Y, and therefore also p~rpendicular to tlle said X axis
and the traYeling direction of carriage 19.
Arm 24 presents a further two motors and position trans-
ducers, 27 and 28, for head 16, and an end fork 30 sup-
porting the said head 16.
The head l6 comprises a first element 31 directly
supporting and connected rigidly integral with member 15;
and a second element 32 directly supportin6 element. 31,
but disconnected from member 15, and, in turn, supported
on end fork 30 inside ~hich it is housed together with
the rest of head 16. Element .31 is powered in known man~
ner (not shown) by motor 27, and mounted on element 32
so as to turn about axis A, whereas element 32 is powered
in known manner (not shown) by motor 28, and mounted on
end 30 so as to turn about axis
Elements 31 and 32 are fitted crosswise
one inside the other, with their respective axes of rota~
t.ion A and ~ intersecting; the said axes A and ~, Wit~
wllich elements 31 and 32 rotate coaxially, being arranged
~0 respectively perpendicular and parallel to the said sheet
2 pick-up plane. In other words, head 16 is constructed
in suctl a manner that. axis A is p~rpendicular to t.he plane
of pic~-up mem~er 15 and to sheet 2 being secured by the
same, whereas axis B is parallel and substantially coplan-
ar to the said sheet 2. The rotation axis ~ of element32 is also located parallel with axis X, and st.rictly pa~
rallel with punch 9 and, therefore, also axis C. ~y vir-
tue of the said structure of the members supporting head
l6, it also follows that, however device 5 is operated,
i.e. moving carriages l9 and 22 and column 21 singly or
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to~eth~r in any direction, axis B moves together with head
16, with no chan~e in its position in relation to the said
reference system stored in system 6 and fixed in relation
to axis C. That is to say, axis B always remains parallel
with bend axis C on press 4 to which handling device 5
is connected. _ ..
Pick-up member 15 con-
sists of a mechanical grip comprising a pair of parallel,
opposed jaws 33 and 34 having a T-shaped horizontal sec-
tion; and a known type of linear actuator 35, preferablyhydraulic or pneumatic, designed to move jaws 33 and 44
perpendicular to their respective planes and along its
own axis of symmetry. Actuator 35 is arranged with its
axis coinciding with rot.ation axis A and, for reasons of
1; size, preferably consists of a pair of air-powered cylin-
ders arranged in series. Jaw 33 is mount.ed integral with
element. 31, which .includes a cylindrical sleeve mount~
ed inside element 32, so as to ~urn about axis A on bear-
ings 36. Jaw 34, on t.he other hand, is mounted integral
2~ with a rod 37 on actuator 35, which rod 37 is, in t.urn,
mounted idly and coaxially inside sleeve 31. ~o prevent
accidental rotation, jaws 33 and 34 are hinged together,
on the end opposite pick-up ed~es 40, by ~ pair of con-
nectin~ rods 42 hinged together and to the said jaws 33
~5 and 34. ~lement 32 is, in turn, hinged coaxially hith axis
on arm 24, by means of pins 44 mounted idly on respect-
ive bearings 45. Arm 24 is substantiallv parallelepiped
and symmetrical in relation to an axis D (Fig.3) inter-
secting axes A and B at the same point, so as to enable
element 31, and pick-up member 15 integral wit.h it, to
13~19~3
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turn through an arc symmetrical in relation to a plane
perpendicular to bend axis C and, in particular, s~mmetri-
cal in relation to axi6 ~.
For enablin6 efficient, interference-free hand-
ling of sheets 2, element 32 must be a]lowed to turn about
axis B through a minimum arc of 235; while, at the same
time, element 31 must be allowed to turn about axis A
through an arc of over 180o. Such is provided for by
tapering arm 24 in the proximity of end fork 30 which,
in the plane perpendicular to axis ~, is defined by oppo~
ed cavities 30a (~ig.2) designed to receive pick-up mem-
ber 15 in its two limit positions about axis B and as
shown by the hatchin~ in Fig.2. Furthermore, column 21
is formed narrower than arm 24; and the whole of device
lj 5 is formed in suc}l a manner as to be smaller, at least
on one side, than the width of arm 24 measured perpendicu-
lar to axis D. Vice versa, symmetrica] 5-shaped jaws 33
and 34 are formed in such a manner that, when viewed hori-
zontally in a plane perpendicular to axis A (Fi~.3), the
'," '~ ~ ,',1,:
widest end having pick-up edge 40 is separated from rota-
, :: .: :.,:: .
tion axis A by a distance "m" greater than half the width
of arm 24 measured crosshise in relation to axis D, so
that the said end projects laterally in relation to arm
24 when pick-up member 15 is turned perpendicular to axis
D, tllUs preventing interference with arm 24 regardless
of whether pick-up member 15 is loaded or not. Sheet 2
may thus be freel~ turned over 180 by turning pick-up
member 15 about axis b, ~ith pick-up member 15 arranged
perpendicular to axis D (subsequent to 90 rotation about
3~ axis A).
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r,~
_ 9 _
Handlin~ devicc S option~lly also comprises at least one
auxiliary pick-up member 50 identical to member 15 and
fitted inte~ral with end 51 of base 18, in a given posi-
tion, for gripping and sustaining sheet 2 held on pick-
up member 15. Close to the said auxiliary pick-up member
50, there is also provided a fixed lateral gauge 53 hav-
ing at least one linear transducer 54 similar'to trans-
duccrs 12. l'ransducer 54 is also connected, over a line
55, to system 6, for supplying t.he said system 6 with
control signal for adjusting the position of device 5.
h'hen operated, device S ~ithdraws sheets 2 one at a time
from store ~ by gripping them in pick-up membe~ 15, and
moves them selectively into a number of different working
positions in relation to axis C. ln particular, as pick~
up member 15 is required to grip one of the lon~ier sitles
of rectangular sheet 2, to prevent undue flexin~, the
short sides of sheet 2 on pick-up member 15 are first bent
as shown in Fi~.s 6 ~nd 8. ~y turning pick-up member 15
about axis A, sheet 2 is then turned ~erpendicular to its
plane, so as to present the long side, opposite the one
~riyped by pick-up member 15, between punch 9 and die 1~
Whi]e the said long side is bein~ gripped between punch
9 and die 10 (~ig.6 7 and 9), pick-up member 15 may be
opened and t.urned again so as to grip the partial]y-bent
sheet 2 by one of its short sides, thus freeing the last.
side for bending. When this is not possible, due to the
small size of sheet 2, it is provided for automat.ically
by device S usin~ auxiliary pick-up member 50, on which
sheet 2 is clamped during displ~cement of pick-up member
15. Durin~ displacement of pick-up member 15, positioning
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~o
accuracy is maintaincd by device 5 setting sheet 2, re-
gripyed by ~ic~-up member 15, against latera~ gauge 53
and transciucer 54, and, subsequently, against back gauge
Il and transducer 12, whictl, via system 6, supply control
signals for corrertly repositioning sheet 2, e.g. by turn-
ing pi~k-up member 15 about axis A and shifting carriage
22 and column 21. Furthermore, during each bending opera-
tion, pic~-up mem~er 15 provides for sustaining stleet 2
whi]e at the same time following the oblique movement of
1~ ttle same induced by punch 9 and die 10, by opening and
turning about axis ~ parallel ~ith bend axis C. ~y turn~
ing pick-uy member 15 about axis A into either of the ]im-
it positions shown in the plan vie~ in Fig.5, and then
abollt axis t~, sheet 2 may also be t.urned over 180 as
1~. alread~ described.
The advantaaes of` the yresent de~ice are clear from
the foregoing description. First and foremost., it provides
for higtlly accurate positioning of sheet. 2, ~due to nume~
rical control disylacement of device 5 and tt~e use of
2~ transducers 12 and 54. Secondly, device S is cheaper and
lighter than known devices, by virtue of being supported
on part. of the press itself. Thirdly, it provides for re-
ducing the floor space, and facilit.flting transport and
installation of the bending system as a wtlole. Also since
~he system is provided with bac~ gauge 11, the press on such
a system may also be operated manually in ttle usual way,
by simyly shifting carrige 1~ over to one end of base 1~
so as to free the front of the press.
