Note: Descriptions are shown in the official language in which they were submitted.
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0067P41CA01
METHOD AND DEVICE P'OR FORMING A FLANGE
OR A RIM ON AN END OF' A STEEL PIPE
The invention concerns a process according to the
precharacterizing portion of Claim 1.
The invention is more specifically concerned with relatively
thin-walled pipes, and in particular those with a diameter in
the range of approximately 100 to 3000 mm and a wall
thicknesses of 1.5 to 6.0 mm. Such pipes are primarily
employed for air lines or conduits, ventilation ducts, device
housings and the like in ventilation, air conditioning and
vacuum engineering, but are however also employed in process
engineering.
There are various types of connections for tightly and
securely connecting individual pipe segments with each other.
These connections have different influences upon the economics
and technical characteristics of the pipe system. Until now
angled, flat or other profiled flanges have - been. employed
which are manufactured separately and seated upon the pipe
end, although advantages of flanges formed directly, that is,
unitarily, as one piece on the pipe ends is readily apparent
and thus a need for such formed-on flanges and rims exist.
The reason that there is a need is due to the lack of an
economically justifiable process for forming desirable flange
shapes on the ends of, above all, mass-produced pipes. Until
now only radially projecting ring rims with relatively low
stability or radially projecting flanges, which are provided
with holes for screwing, are formed onto the pipes. The
latter is employed primarily for ventilator housings. The
simple ring can be produced with two rollers using a beading
and rim machine. The latter flat flanges with holes are
produced in a press process. For this, the pipe body is
caused to rotate with high rotational speed, which is possible
only with very short pipe bodies such as axial ventilator
housings. The pipe ends are inserted into a die or negative
pattern of the flat flange to be formed. With a pressure
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a
lever, on the end of which a roller revolves, pressure is
applied against the rapidly rotating pipe end until the
material is caused to flow and lie against the negative
pattern. The "pressure" process is somewhat similar to the
deforming of clay using a potter's wheel. It is also used for
the forming of ring flanges on short pipe rings, which are
then subsequently seated upon a pipe end and secured thereto.
This latter process is described, for example, in DE 196 32857
A1.
This known process is poorly suited to the formation of
flanges directly onto pipe ends, since it is .almost impossible
and besides this dangerous to spin larger pipes with the
necessary speed of rotation. Further, the energy required for
many types of forming in the case of a wide variety of
different pipes is much too high for an economical process.
Above all, however, the manufacture of complex flange shapes,
such as for example conical flanges or the like, is not
possible due to the occurrence therein of cutbacks or
inclusions, since in this case the mold or pattern cannot be
removed again from the finished flange.
For the manufacture of boxes, frames, profiles, or channels
with straight edges the so-called beveling process or pivot
bend process is known. For this, a planar sheet metal plate
is clamped or tensioned between a fixed lower member and a
moveable upper member, and bent using a pivotable bending
member. The great advantage therein is that during pivot
bending an entire sheet metal segment can be raised, or as the
case may, be curved, without any stretching. The sheet metal
materials need flow only in the area of the edge being formed.
All the remaining material remains completely unchanged.
Thus, the edge profile without stretching and without any
particular effort is precisely straight and free of tension.
In contrast thereto in the case of the above-discussed
"pressing" the entire material is bent through and thereby
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unavoidable tensions are introduced. Accordingly, the energy
required for pivot bending is substantially less.
The present invention is concerned with providing a process
and a device for carrying out this process, in which the one-
piece forming of even complicated flanges and rims not only on
short pipes, but rather in particular also on long pipe
segments, is economically possible.
This task is inventively solved with respect to the process by
the characterizing features of Claim 1 and with respect to the
device by the characteristics of Claim 5.
The dependent claims are directed primarily to advantageous
embodiments of the invention.
It is the basis of the inventive process to employ the
advantages of the linear pivot process also in the case of
bending at pipe .ends. It is thus referred to herein as the
circular-pivot-bending process.
The linear pivot bending process can obviously not be applied
to round pipes without modification, since herein the edges to
be produced are not straight or linear, but rather curved, and
these curved edges are to be produced with various radii with
as few change-outs in work tools as possible. The invention
accomplishes this by circumferential clamping of the pipe ends
from inside, for example by means of a clamping disk. This
clamping disk in has a slightly smaller diameter than the pipe
inner diameter prior to clamping. Following insertion into the
pipe it is widened, that- is, the diameter is increased, until
it lies with its outer circumference tightly against the inner
surface of the pipe wall. The clamping disk or other device
used for clamping can be connected with a strong drive axle
for imparting the rotational movement. The tight clamping of
the pipe end is thus also simultaneously used for the rotation
of the pipe, wherein naturally only substantially lower
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,.
rotational speeds are necessary than in the case of the
pressure process. It is necessary that sufficient friction is
created between the inner surface of the pipe and the clamping
device, for example clamping disk, such that the pipe can be
rotated against the resistance of the bending tools.
It is on the other hand basically also possible to allow the
pipe and the therewith rigidly connected parts of the device
to remain stationary and to rotate the bending tools and the
therewith rigidly connected parts about the pipe axis.
The subsequent bending out of a part of the projecting pipe
piece to form a rim or flange about the circumference of the
pipe piece being modified occurs continuously during the
rotation of the pipe. For this, a pivotable bending jaw is
preferably employed, which in its rest position lies against
the inner side of the pipe end. Its axial breadth should be
at least somewhat larger than the segment of the pipe end to
be bent. Thereby it is ensured that the segment to be bent is
raised as a whole, and not changed in its straight shape.
Preferably the contact surface of the bending jaw on the pipe
end should have the same radius as the inside of the pipe,
such that the segment of the pipe end to be bent has a large
surface area contact surface. Im principle however a circular
shape of the contact surface of the bending jaw, with a
somewhat smaller radius than the inside of the pipe, is also
possible. Since the pivotable bending jaws can bend
respectively only one partial segment of the pipe
circumference, the pipe must be caused to rotate in an even,
slow rotation. When the pipe rotates, the bending jaws are
slowly pivoted unto the position of the desired bending angle.
This inventive process can thus ,be properly referred to as a
circular-pivot-bending process.
In a preferred embodiment of the invention it is possible to
additionally apply pressure upon the bending point of the pipe
from the .outer side of the pipe,. preferably using a shaping
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roller or the like, wherein a tip of the shaping roller cross-
section terminates at that location, where the pipe end is to
be bent over. Thereby the shape of the bent edge (sharp or
round) can be predetermined quite precisely. The remainder of
the cross-sectional shape of the shaping roller is determined
by the maximal angle of bending of the tip-stretch profile.
Since substantial forces are applied upon the shaping roller
during the bending process, a precondition for obtaining a
clean bent-edge is thus a rigid mounting and positioning of
the shaping roller. Preferably, the shaping roller and its
mounting are connected to a fixed unit with the likewise fixed
and non-rotating bending jaws and the drive means therefore,.
whereby the stability of the device is substantially
increased.
In the case that high precision in the form of the shaped
flange or rim is not required, it is possible in the case of
relatively small pipe thicknesses, to bend these without using '
a shaping roller. In this case the curvature of the pipe wall
there suffices to provides sufficient resistance to bending.
Sharp bent edges are therein however not possible, and with
the increase in the wall thickness the radius of the bent edge
continuously increases.
The sequence of steps of the inventive process, as well as
preferred embodiments of the inventive device, will now be
described in greater detail with reference to the figures.
There is shown
Figs. 1-12 the process steps of the inventive process on the
basis inventive process, showing the steps for
forming a conical flange on the end of a pipe,
wherein the device parts shown schematically in
side view serve only as an example of the results
to be achieved by the process and wherein other or
differently shaped designs can be achieved,
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Fig. 13 a schematic side view of a first embodiment of the
device for carrying out the inventive process in a
first processing position,
Fig. 14 a side view of the device according to Fig. 13 in
a second processing position,
Fig. 15 a side view of the device according. to Fig. 13 in
a third processing position,
Fig. 16 a schematic partial section along the line XVI-XVI
in Fig. 13,
Fig. 17 a schematic frontal view of the clamping disk
employed in accordance with the process shown in
Figs. 13 through 18,
Fig. 18 a schematic side view of the parts shown in Fig.
17,
Fig. 19 a schematic side view of a clamping disk, pipe and
the parts of the drive device of the inventive
device,
Fig. 20 a sectional side view, shown in reduced scale
compared to Fig. 19, of a part of the components
shown in Fig. 19,
Figs. 21
and 22 an axial section or, as the case may be, schematic
side view of a different embodiment of the
clamping disk,
Figs. 23
and 24 schematic side views of pipe, clamping disk,
bending jaws and shaping rollers with different
locations or positions of the bending jaws,
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Figs. 22
through 29 a schematic partial view of a clamping disk and a
bending jaw in different bending positions with
shaping rollers having differing cross-sections
or, as the case may be, without shaping rollers,
Figs. 30
and 31 partial broken away schematic oblique views of
parts of an inventive device with pipe, clamping
disk, shaping rollers and bending jaws in the
resting or, as the case may be, bending position
of the bending jaws,
Fig. 32 a partial oblique view corresponding to Fig. 30
but without pipe and shaping roller,
Figs. 33
through 35 a partial representation according to Fig. 32 with
respectively three differing embodiments of the
bending jaws, and
Fig. 36 a schematic partial view of an embodiment with two
inventive devices working simultaneously on both
ends of a pipe.
Figs. 1 through 12 show respectively in schematic partial
representation the process steps of the inventive process on
one pipe end. Fig. 1 shows, for simplification, a largely
broken away partial sectional view through an unprocessed pipe
12 with circular cross-section and with end 10 facing towards
the right in Fig. 1. Fig. 2 shows the condition of the pipe
end 10 following the first processing step. The pipe end 10
has become a pipe piece to be further bent, which presently is
bent outwards approximately 150° about a rounded-off bending
edge 14 relative to the axial direction 16 of the pipe 12.
Fig. 3 shows the condition of the pipe 12 following a second
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circular pivot bending process, wherein the second pipe piece
18 bordering the first pipe piece 10 is bent outwards about a
sharp angle or edge 20 about a right angle against the axial
direction 16. Thereby a conical flange is produced from the
combination of the adjacent lying pipe pieces 10 and 12, which
are formed as a single piece on the pipe 12.
The subsequent Figs. 4 through 12 illustrate schematically the
manner of operation of a device for carrying out the inventive
process. In all figures for comparison purposes the same
parts are indicated with the same reference numbers.
Fig. 4 shows a not-yet-clamped pipe 12 close to a clamping
disk 22 in its not yet expanded resting state, which clamping
disk 22 is rigidly connected to a drive shaft 24 which can be
caused to rotate upon application of force. A first bending
jaw 26 for bending the first pipe piece 10 about 250° into a
position shown in Fig. 2 is represented in Fig. 4 in the
starting position prior to the bending process, in partially
broken away view. Therein it is to be noted that Figs. 1
through 3, in comparison to Figs. 4 through 12, are mirror
images rotated 180° perpendicular to the pipe axis 28. A
second bending jaw 30 is rotated by 180° about the pipe axis 28
relative to the first bending jaw 26 shown likewise in its
resting position prior to the bending process and shown
partially broken away. The second bending. jaw 30 serves for
bending or introducing the angle into the second pipe piece 18
90° relative to the axial direction 16 of the position shown in
Fig. 3. In Fig. 4 there are further shown a first shaping
roller 32 and a second bending roller 34 likewise shown in
their resting positions distanced from the pipe 12. The first
bending roller has a cross-section with rounded off tip 36, of
which the flanks 40 encompass an angle of 30°. Rotated by 180°
about the pipe axis 28 is the second bend roller 34 provided
removed from the pipe 12 into its resting position, of which
the cross-section has a sharp angle 38 and of which the flanks
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42 define a 'right angle. The shown condition of the device
corresponds to the starting position of the process.,
Fig. 5 shows a subsequent process stage, in which the clamping
disk 22 is introduced into the pipe 12 and is extended to is
spread position according to arrows 44 against the inner
surface of the pipe 12 from the inside. Together with the
clamping disk 22, the bending jaws 26 and 30 are introduced
into the pipe end, but are however both still in the rest
position with respect to their pivoting for bending open the
pipe end. Likewise, both shaping rollers 32 and 34 are still
located in their rest position just as in Fig. 4. At the same
time the drive shaft 24 is brought to rotate in the direction
of arrow 46, so that the clamping disk 22 rotates together
with the pipe 12, while the bending jaws 26 and 30 as well as
shaping rollers 32 and 34 do not rotate about pipe axis 28.
The friction resistance between the cylindrica l outer surface
48 of the clamping disk and the inner surface of the pipe 12
is so large, due to the clamping of the clamping disk 22 in
its working position according to Fig. 5, that the pipe 12
rotates along with the clamping disk even overcoming large
resistance.
The next process step of the shaping process is shown in Fig.
6, wherein the first shaping roller 32 is moved to its work
position lying solidly against the outer side of the pipe 12,
having been moved along the displacement axis 52 according to
arrow 50.
According to Fig. 7, next the first bending jaw 26 is bent
about an angle of 150° out of its resting position (Fig. 6)
into its work position (Fig. 7), said pivoting about an axis
perpendicular to the plane of the drawing, whereby the first
pipe piece 10 projecting beyond the clamping disk 22 is bent
outwards about 150° about the first shaping roller 32. Since
drive shaft 24 and clamping disk 22 rotate simultaneously
together with the clamped pipe 12 about the rotation axis 28,
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after only a few rotations of these parts about the pipe axis
28 the pipe piece 10 is bent outwards about 150° from the pipe
12 about the rounded off edge 14. By the rotatable mounting
of the shaping roller 32 the frictional resistance of the pipe
piece 10 occurring at the location of bending is substantially
reduced.
Subsequently, according to Fig. 8, the first shaping roller 32
is withdrawn along the displacement axis 52, according to
arrow 56, out of the work position and back into its rest
position away from the pipe 12, and at the same time the first
bending jaw 26 is pivoted back out of its work position
according to arrow 58, back into its rest position.
In the next processing step according to Fig. 9 the second
shaping roller is moved out of its resting position along the
displacement axis 60 according to arrow 62 into the working
position in solid contact against the outer side of the pipe
12. All of these process steps occur while the drive shaft
24, the clamping disk 22 and the pipe 12 rotate about the
rotation axis 28 and the first bending jaw 26, second bending
jaw 30 as well as the two shaping rollers 32 and 34 remain at
rest. Preferably the rotating parts and the non-rotating
parts are assembled respectively to stable work units. Within
the non-rotating work tool unit, naturally the moveability of
the individual parts to and from the rest position and the
drive positions must be made possible. On the other hand, it
is naturally also possible to allow the drive shaft 24,
clamping disk 22 and pipe 12 comprising work unit to remain at
rest and the other work unit comprised of the bending jaws and
the shaping rollers to rotate about the pipe axis 28.
In the subsequent processing step according to Fig. 10 the
second bending jaw 30 is pivoted according to arrow 64 out of
its resting position into the working position, whereby the
second pipe piece 18 projecting beyond the clamping disk 22 is
bent outwards with a sharp bent angle 20 of 90° corresponding
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to the cross-section of the second shaping roller 34. The
complete bending of the second pipe piece 18 away from the
pipe 12 towards outwards is accomplished after the rotating
parts 24, 22 and 12 have carried out a few rotations about the
pipe axis 28.
In the next processing step according to Fig. 11 the second
shaping roller 34 is retracted from the pipe 12 along the
displacement axis 60 according to arrow 66 and the second
bending jaw 30 is pivoted back to its resting position along
arrow 68.
Therewith the path is cleared for the return movement of all
parts back to the starting position as shown in Fig. 4. Thus,
at the end of the process, all parts in accordance with Fig.
12 are again located in the starting position according to
Fig. 4, and the result of the inventive work process is the
one-piece or unitary forming onto the end of the pipe 12 a
flange comprising the pipe segments 10 and 18.
In Figs. 13 through 16 a preferred embodiment of the device
for carrying out the inventive process is shown schematically
with the parts necessary for carrying out the invention. For
improved overview, individual parts of the pieces are omitted,
for example from the. pipe 12, the clamping disk 22, the drive
shaft 24 and the bending jaws 26. It is further to be noted
that in the illustrated device only one bending jaw 26 and
shaping roller 32 is shown, which is suitable for a single
bending process of a projecting pipe piece 10. Obviously
additional bending jaws and shaping rollers can be provided
about the rotation axis 28 outside of the plane of the
drawing. Their detailed description can however be omitted,
since- they' function in the same manner as the parts shown in
Figs. 13 through 16. If an individual work unit comprised of
bending jaw and shaping rollers is employed for each bent
edge, then this has the advantage, that for the individual
processing steps no work tools need be changed. It is
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necessary particularly in mass production that the processing
units can come into engagement sequentially without
interference.
Each of the work units including one bending jaw 26 and one
shaping roller 32 is respectively mounted on a mobile sled 70,
wherein multiple sleds can be mounted radially on a base plate
72. In this manner the individual processing units can be
easily adapted to the respective diameters of the pipe 12 to
be processed. Each sled 70 can be moved along two parallel
sled guides 71 according to the double arrow 74 via a threaded
spindle 78 rotated by a rotational drive 76.
Two parallel side plates 80 (Fig. 16) are provided parallel
and spaced apart from each other on the sled 70, which are
connected rigidly with each other in the manner of a frame by
intermediate plates 82. Between the two side plates 80 lying
slidingly on the inner sides of the side plates 80 is a broad,
somewhat circular or cylindrically shaped sector plate 84, on
which by means of screws 86 the bending jaws 26 are secured.
The sector plate 84 forms, parallel to the side plates 80, as
can be seen in the cross-section of Fig. 13, an incomplete
sector of a circle, of which the middle segment lying opposite
the circular arc 88 is missing, since the center of the arc
sector must remain free for the bending process of the pipe
piece 10. The angles 90 and 92 connecting to the outside of
the circular arc 88 intersect outside the center point of the
arc 88. The bending jaws 26 are secured to the flat surface
92 of the sector plate 84 by screws 86.
It is to be noted that in Fig. 16, in comparison to Figs. 13
through 15, only those parts necessary for the pivoting of the
bending jaws 26 is shown.
The guidance of the sector plate 84 during the necessary
pivoting together with the bending jaws 26 occurs by guide
rollers 94, which run in arc-shaped guide grooves 96 in the
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side plates 80. The guide rollers 94 project on both sides
beyond the sides of the sector plate 84 and are respectively
guided in a guide groove 96. In the cylindrical circumference
surface of the sector plate 84 corresponding to the arc 88 of
the cross-section of the sector plate 84 there is provided
gear teeth 98, which are in engagement with a drive pinion 102
driven by rotational drive 100. The sector plate 84 can
therewith be pivoted out of the rest position of the bending
jaws 26 according to Figs. 13 and 14 into the work position of
the bending jaws 26 corresponding to the position shown in
Fig. 15. The pivot angle of the sector plate 84 can therein
be freely widely selected and corresponds in. the present case
to the angle between the two flanks of the cross-section of
the shaping roller 32.
From Figs. 13 through 15 it can further be seen, that the
shaping roller 32 is mounted rotatable about its central axis
105 in a fork shaped mounting block 104., which for its part is
moveable along double arrow 50, 56 out of its resting position
according to Fig. 13 into the working position according to
Fig. 14. For moving the mounting block 104 a threaded spindle
106 is provided driven by a drive motor 108. It is important
that the mounting block with shaping roller is secured in work
position rigidly and capable of accepting high loads,
according to Fig. 14 and 15, with the working unit comprised
of bending jaws, shaping rollers and associated parts.
In the work condition according Figs. 13 through 15 the
clamping disk 2Z is introduced into the pipe end by movement
of the pipe 12, while. it is still in its resting state as
described above. Subsequently, the clamping disk 22 is, as
described in greater detail below, spread to its work position
and now cylindrically clamps pipe 12 from the inside. From
this there results a pipe piece 10 projecting beyond the
cylindrical outer surface of the clamping disk 22, which is to
be subsequently further bent in accordance with the following
bending process. Prior to the sliding on of the pipe 12 upon
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the clamping disk 22 the working unit comprised of bending
jaws, 'shaping roller and associated parts and drive mechanism
is so adjusted by means of movement of the sled 70 along the
double arrow 78 with respect to the fixed base plate 72, that
it is adapted to the respective diameter of the pipe 12. In
Figs. 13 through 15 such a working unit is shown. Additional
work units can be mounted on the base plate 72 with mostly
doubled sled guides 71 radiating outward from pipe axis 28, so
that they can be sequentially brought to bear upon the pipe
12, in order to respectively deform one pipe piece to a part
of a complicated flange. For each sled 70 there is therein
provided one rotation drive 76 with threaded spindle 78, a
threaded follower 110 running upon the threaded spindle 78 and
a mounting means 112 connecting this with the sled 70, wherein
the mount 112 can be displaced in a slit 114 of the base plate
72 running radially to the pipe axis 28.
In the following the design and manner of operation of a first
embodiment of the clamping disk 22 is described in greater
detail on the basis of Figs. 17 through 20. Since the task of
the clamping disk 22 is comprised therein, to prevent the
deformation or change in form of the pipe inner side, it is
important that a substantially complete contacting of the
inner cylindrical circumference 116 of the pipe wall occurs.
The shown preferred embodiment of the clamping disk is thus
subdivided into multiple, in the illustrated embodiment six,
sectors 118, which in a subsequently in greater detail
described manner can be spread from their inner rest position
shown in the left half of Figs. 17 and 18 into an outward work
position in tensioned manner on the inside of the pipe 12
shown in the right half of Figs. 17 and 18 via an axial drive,
for example, a hydraulic cylinder 124 driven pull rod 122.
The number of the sectors is as large as desired. Therein a
larger number of sectors has the advantage, that the gap 126
between the sectors 118, which result following spreading of
the clamping disk 22, becomes smaller, and it covers the wall
of the pipe 12, even when the pipe is very thin . walled,
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without changing the shape of the pipe. The sectors 118 are
arc sectors and end, a distance from the pipe axis 28, in a
cylindrical-sectional inner surface 128. The radial breadth
of the sectors 118 can be freely selected, in order to conform
the diameter of the clamp 22 to the respective diameters of
the pipe 12. The adaptation or conforming can occur by the
simple exchange of sectors 118. The inner surfaces 128 of
sectors 118 lie on the cylindrical outer surfaces 130 of
cylindrical shaped clamp jaws 132. The sectors 118 are
secured by radial screws 142 to the clamp jaws 132. The clamp
jaws 132 have a slanted inner face surface 134 with respect to
the pipe axis 28, which respectively lie against a face 136 of
the widening end 120 of the pull rod 122. In the illustrated
embodiment the widening 'end 120 has a hexagonal cross-section,
so that one side surface is provided for each of the six clamp
jaws 132.
The main drive shaft 24 for rotating the clamping disk and the
pipe 12 is centrally axially bored through, and the pull rod
122 extends through this bore. By actuation of the hydraulic
cylinder 124 the pull rod 122 can be moved from the rest
position 138 shown in the lower half of Fig. 19 to the wider
or working position 140 shown in the upper half of Fig. :19.
Thereby the sectors 118 are moved out of the rest position
shown in the left half of Figs. 17 and 18 with close spacing
from the inner surface of the pipe 12 into the working
position shown in the right half of Figs. 17 and 18 lying with
tension against the inner surface of the pipe 12. This
movement is caused by the appropriate displacement of the
clamp jaws 132.
The drive shaft 24 extends through a cutout 144 of the base
plate 72 of the overall device and is mounted rotatably in a
manner known to those of ordinary skill and is caused to
rotate by a drive motor 146 with hollow shaft drive 148. The
opposite end of the drive shaft 24 exhibits a mushroom shaped
widening 150 with a planar end face 152, upon which the planar
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slide surfaces 154 of the clamping jaws 132 lie radially
slideable. The slide surfaces 156 of the clamp jaws lying
opposite to the slide surface 154 lie slidingly against the
inner surface of a counter slide 158, which is secured by
screws 160 to the mushroom shaped widening 150. The screws
160 pass through the mentioned holes 169 in the clamp jaws
132, which allow the necessary slight radial displacement of
the clamp jaws 132. ,
The screws 160 are surrounded by distance casing 162, which
together with the holes 169 of the clamp jaws 132 allows a
linear radial guidance of the clamp jaws 132.
The hydraulic cylinder 124 for operating the pull rod 122 is
supported axially on the drive means 148 for the hollow drive
shaft. The already sufficiently large force of the hydraulic
cylinder 124 is again amplified as desired by the slanting of
the widening end 120 of the pull rod 122 relative to the pipe
axis 28. In this manner the necessary amount of clamping
force is produced, which produces a sufficient frictional
connection of the clamping disk 22 to the pipe wall, in order
to rotate the pipe against the resistance of the bending tools
(bending jaws 26 and shaping roller 32). Of course, the
slanting of the widening end 120 can be reversed, that is, be
reduced towards the right in Fig. 19, in the case that an
oppositely operated pressure rod is employed.
The return of the clamp jaws 132 during de-tensioning of the
clamping disk 122 back into its rest position can occur in
simple manner by not shown springs, which are incorporated in
the individual clamp jaws, or by an endless pull-spring
running about the outer circumference of the clamp jaws,
likewise not shown, which would be incorporated in a likewise
not shown groove.
Alternatively, the drive shaft 24 can, in the embodiment shown
in Fig. 20, be mounted via a ball rotation ring 164, of which
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the outer side (or even the inner side) is provided with gear
teeth 166. The drive motor 146 in this case is seated beside
the ball rotation ring 164. The pinion 168 of its drive shaft
170 engages in the teeth of the ball rotation ring 164 and
brings about a driving of the drive shaft 24. Naturally,
other mounting types well know to those of ordinary skill can
be considered.
An alternative advantageous embodiment of the clamping disk
referred to in general with 22 and the drive therefore is
shown in Figs. 21 and 22. In this embodiment the clamping
disk 22 exhibits clamp ring 174 with cylindrical circumference
surface 116 and conical inner surface 176, which clamp ring
174 is divided by a circumferentially running slanted slit
172. Against the conical inner surface 176 lies the outer
surface 178 of the clamp plate 180 having the same conical
shape, which by means of bolts 182 and nuts 184 is secured to
the widened end 186 of the pull rod 122. By displacement of
the pull rod 122 in the sense of the double arrow 188 between
the detensioned resting position shown in the upper half of
Figs. 21 and 22 and the tensioned work position shown in the
lower halves of Figs. 21 and 22 the clamp ring 174 allows
itself to be tensioned or as the case may be detensioned with
development any desired amount of force. A slit of the
clamping ring 174 running in the axial direction parallel to
the pipe axis 128 would also be possible. The slanted
arrangement of the slit 172 however prevents, that the gap
opening during clamping causes a gap in the widening of the
pipe wall causing a deformation or wrinkle in this location.
The return of the clamp 174 during detensioning occurs in this
case by the spring effect of the clamp ring itself. As
necessary the spring effect can be amplified by a not shown
circumscribing endless pull spring in a groove of the clamp
ring 174.
It is apparent that the sheet metal thickness of the pipe 12,
the desired flange shape, or a material change of the clamping
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disk 22 has no influence on the desired flange shape. The
pipe end 10, 18 is respectively slid so far over the clamping
disk 22, until sufficient material becomes available for the
forming of the designed flange.
In the subsequent Figs. 23 through 35 advantageous embodiments
of bending jaws 26 and shaping rollers 32 are shown together
with a segment of the pipe 12 to be deformed as well as a part
of the spread clamping disk 22. Figs. 23 and 24 show a first
embodiment of these parts, wherein in the above described
manner the shaping rollers 32 are moved into a working
position pressed against the outer side of the pipe 12. The
bending jaw 26 pivotable in the above described manner lies in
its rest position against the inner side of the pipe piece 10
to be bent and extending beyond the clamping disk 22,
whereupon the pipe wall is clamped and held between the
clamping disk 22 and shaping roller 32. The tip 36 of the
cross-section of the shaping roller 32 ends at the point,
where the projecting pipe piece 10 is to be bent. By the
shape of the shaping roller 32 the shape of the bending edge
on the pipe end can be determined.
The pivotable bending jaw 26 lies on its resting position
according to Fig. 23 against the inner side of the pipe- piece
10. Its axia l breadth is at least somewhat larger than the
axial length of the pipe piece 10 to be bent. Thereby it is
ensured that the pipe piece to be bent is lifted as a whole
and thus is not changed in its linear shape. Likewise the
cylindrical contact surface 190 of the bending jaw 26 should
have the same radius at the pipe end as the pipe inner side,
so that the pipe piece 10 to be bent has a large surface area
contact surface.
Since the pivotable bending jaw 26 can only bend a partial
area of the pipe circumference, the pipe 12 must be caused to
rotate in an even, slow rotation. If the pipe 12 rotates,
then the bending jaw 26 is pivoted slowly to the desired
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CA 02424583 2003-03-24
bending angle (Fig. 24). The bending jaw 26 remains in this
work position until the end of its last complete rotation of
the pipe 12 about the pipe axis 28, whereupon the bending out
of the pipe piece 10 is ended.
So that the pipe 12 following the forming of the flange or rim
can be removed from the clamping disk 22, the shaping roller
32 with its mounting lock 104 must be withdrawn to a rest
position sufficiently far from the pipe. For a further
circular bending process now a further processing unit, which
is adjusted to a further bending angle, is brought to action
in the above-described manner.
For the easier introduction of the clamping disk 22 into the
pipe end 10 the introduction side of its cylindrical outer
surface 48 can exhibit a conical narrowing 192.
In Figs. 25 through 28 various embodiments of the shaping
roller 32 or, as the case may be, 34 are shown with narrow tip
36 or, as the case may be, right-angled tip 38. The tip 36
serves for bending of the pipe piece 10 about 150°, while the
tip 38 serves for bending the pipe piece 10 about 90°.
In Fig. 29 there is schematically shown how, absent precise
demands on the forming precision of the formed flange or rim,
one can entirely bend without shaping rollers and only with
clamping disk 22 and bending jaws 26.
Figs. 30 and 31 show an embodiment of the bending jaw 26 with
almost half cylindrical contact surface 190 in .resting
position (Fig. 30) and work position (Fig. 31).
Fig. 32 shows in somewhat ' enlarged scale a partial
representation of a somewhat differently shaped bending jaw 26
with flatter cylindrical contact surface 190, which is secured
by screws 86 to a only partially shown, pivotable sector plate
84. The contact surface 190 lies with all its frictional
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CA 02424583 2003-03-24
force against the inner wall of the not shown pipe. In the
following figures the individual advantageous embodiments of a
similar bending jaw 26 as in Fig. 32, however with less
friction between contact surface 190 and pipe inner wall is
shown. It is actually ideal, when the working radius of the
contact surface 190 of the bending jaw 26 corresponds to the
pipe inner diameter. Without serious disadvantage the radius
of the contact surface 190 can however be smaller than the
pipe inner radius. Thereby it is possible, with the same
bending jaws to change through multiple pipe diameters. In
the main friction location in the center of the contact
surface 190 there can, for a substantial reduction of friction
and drive, in the bodx of the bending jaw 26 a roller mounted
support roller 194 be introduced, of which the rotation axis
196 runs paralle l to the contact surface 190 and of which the
circumference surface 198 projects slightly beyond the contact
surface 190. The pipe piece 10 to be bent then lies in this
area free of friction on the circumference surface 198 of the
support roller 194.
The bending jaws 26 can be further improved by introduction of
a whole series, or chain of support rollers 194 in the contact
surface 190 in the same manner as the support roller 194
according to Fig. 34. In the shown embodiment according to
Fig. 34 five such support rollers 194 are provided in a chain.
The remaining part of the contact surface 190 between the
support rollers 194 prevents a drooping of the wall of the
pipe 12 between the support rollers 194 which would result in
wave formation and stretching or distortion.
A minimal friction between bending jaws 26 and the inner wall
of the pipe 12 is achieved when the bending jaws 26 according
to Fig. 35 are fully. cylindrical with cylindrical contact
surfaces 190, wherein the entire cylindrical bending jaws 26
are mounted rotatable about a drive shaft Z00 on the sector
plate 84. Although in this manner the least amount of
friction is produced, since however in most cases insufficient
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CA 02424583 2003-03-24
space is available for a large diameter of the cylindrical
shaped bending jaws 26, one must accept the disadvantages in
the deformation formation as well as stretching of the pipe
wall. These disadvantages are lesser in the case of greater
pipe wall thicknesses so, that in the case of bending
thicknesses above 1.5 mm such a "bending roller" can be
employed in the place of bending jaw 26.
The total inventive device for carrying out of the inventive
circular pivot bending process can selectively be carried out
both in the horizontal as well as in the vertical pipe axis
28, wherein there is preferred on the one hand straight pipes
and on the other hand shorter pipe-shaped pieces to be shaped.
For a rational preparation of straight pipes with flanges 10,
18 formed on both ends using the inventive circular bending
process, devices 204 of the described type are seated upon a
common rail system designated overall with 202 mounted to be
slidable according to the double arrow 206, so that the
clamping disk 22 and bending jaws 26 indicated schematically
lie on opposite ends. Each device 204 can be moved using an
independent driven threaded spindle 208 in the rail system
202.
For introduction of the pipe 12 the devices 204 are moved
apart from each other, until the pipe length of the pipe 12
fits between the clamping disk 22. After that both devices
204 are moved towards each other, the clamping disks 22 are
introduced into the pipe ends until reaching an abutment,
which is set to the processing. length of the pipe. Both
clamping disks 22 are clamped in the processing position, and
processing occurs subsequently simultaneously on both sides.
For removal of the pipe 12 the devices 204 must again be moved
apart from each other.
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CA 02424583 2003-03-24
Reference Number List
first projecting pipe piece
12 pipe
14 bending edge
16 axial direction of the pipe
18 second projecting pipe piece
sharp bending edge
22 clamping disk
24 drive shaft
26 first bending jaw
28 pipe axis
second bending jaw
32 first shaping roller
34 second shaping roller
36 tip of first shaping roller
38 tip of second shaping roller
flanks, first shaping roller
42 flanks, second shaping roller
44 arrow showing spreading direction
46 arrow, drive shaft
48 outer surface
arrow
52 displacement
axis
54 arrow
56 arrow
58 arrow
displacement
axis
62 arrow
64 arrow
66 arrow
68 arrow
sled
71 sled guide
72 base plate
74 double arrow
76 rotation drive
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CA 02424583 2003-03-24
78 threaded spindle
80 side plate
82 intermediate plates
84 sector plate
86 screws
88 arc
90 straight
92 straight
94 guide rollers
96 guide rollers
98 gears
100rotation drive
102drive pinion
104mounting block
105central axis
106threaded spindle
108 drive motor
110 spindle follower
112 holder
114 slit
116 .circumference
118 sector
120 widening end
122 pull rod
124 hydraulic cylinder
126 gap
128 inner surface
130 outer surface
132 clamp jaws
134 end face
136 end face
138 rest position
140 work position
142 screw
144 segment
146 drive motor
148 hollow shaft internal gear
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CA 02424583 2003-03-24
150 widening
152 end face
154 slide surface
156 slide surface
158 counter disk
160 screws
162 distance housing
164 ball rotation mount
166 gear
168 pinion
169 holds
170 drive shaft
172 slit
174 clamping ring
176 inner surface
178 outer surface
180 clamping plate
182 bolt
184 nut
186 connecting end
188 double arrow
190 contact surface
192 slanting
194 support roller
196 rotation axis
198 circumference
200 drive shaft
202 rail system
204 circular rivet bending device
206 double arrow
208 threaded spindle
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