U.S. patent application number 12/281945 was filed with the patent office on 2009-12-10 for flanging machine and method for spin-flanging workpieces.
This patent application is currently assigned to GM GLOBAL TECHNOLOGY OPERATIONS, INC.. Invention is credited to Jens Baumgarten, Peter Plapper.
Application Number | 20090301160 12/281945 |
Document ID | / |
Family ID | 38109913 |
Filed Date | 2009-12-10 |
United States Patent
Application |
20090301160 |
Kind Code |
A1 |
Baumgarten; Jens ; et
al. |
December 10, 2009 |
FLANGING MACHINE AND METHOD FOR SPIN-FLANGING WORKPIECES
Abstract
A crimping device (1) comprising a crimping bed (12) provided
for receiving a workpiece (10), a multiaxial manipulator, in
particular an industrial robot (2), which has a crimping tool (5)
with at least one crimping roller (6) on its hand, is intended to
avoid fold formation on the flange (11), particularly during the
pre-crimping. To this end, at least parts of the crimping roller
(6) have the form of a cone or a truncated cone having an axis of
symmetry (27), an apex (26), and an opening angle .alpha., wherein
for the opening angle .alpha. of the cone it holds that
180.degree.>.alpha..gtoreq.140.degree..
Inventors: |
Baumgarten; Jens;
(Hildesheim, DE) ; Plapper; Peter; (Russelsheim,
DE) |
Correspondence
Address: |
INGRASSIA FISHER & LORENZ, P.C. (GME)
7010 E. COCHISE ROAD
SCOTTSDALE
AZ
85253
US
|
Assignee: |
GM GLOBAL TECHNOLOGY OPERATIONS,
INC.
Detroit
MI
|
Family ID: |
38109913 |
Appl. No.: |
12/281945 |
Filed: |
March 7, 2007 |
PCT Filed: |
March 7, 2007 |
PCT NO: |
PCT/EP2007/001944 |
371 Date: |
July 2, 2009 |
Current U.S.
Class: |
72/306 ;
72/312 |
Current CPC
Class: |
B21D 19/043 20130101;
B21D 39/023 20130101; B21D 39/021 20130101 |
Class at
Publication: |
72/306 ;
72/312 |
International
Class: |
B21D 39/02 20060101
B21D039/02; B21D 19/04 20060101 B21D019/04 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 7, 2006 |
DE |
10 2006 010 469.2 |
Claims
1. A flanging machine comprising: a flanging bed adapted to receive
a workpiece; and a multi-axle manipulator adapted to carry a
flanging tool at a hand with at least one flanging role, wherein at
least one part of the flanging role has a form of a cone with an
apex, an at least substantially symmetrical axle running through
the apex, and an apex angle .alpha. of a specified surface area to
be pressed on a flared flange, wherein the apex angle .alpha. of
the cone is in a range of about
180.degree.>.alpha..gtoreq.140.degree..
2. The flanging machined according to claim 1, wherein that the
range is about 180.degree.>.alpha..gtoreq.160.degree..
3. The flanging machined according to claim 1, wherein a base area
of the flanging role has a diameter d with d.gtoreq.about 60
mm.
4. The flanging machined according to claim 1, wherein the flanging
role is a pre-flanging role.
5. The flanging machined according to claim 1, which comprises an
additional flanging role adapted for final-flanging processes,
wherein the flanging role has a cylindrical form after the
final-flanging processes.
6. The flanging machine according to of the claim 1, wherein the
flanging role is adapted for use in pre-flanging and final-flanging
processes.
7. A method to spin-flanging workpieces, comprising the steps of:
provisioning of the workpiece to be flanged with a flange on a
flanging bed; pre-flanging of the flange with a pre-flanging role
that has a conical form and is guided by a multi-axle manipulator,
wherein for the apex angle .alpha. of a lateral surface of the cone
to be pressed on the flared flange it is in the range of about
180.degree.>.alpha..gtoreq.140.degree.; and final-flanging of
the flange.
8. The method according to claim 7, wherein the final-flanging is
carried out with a final flanging role having a cylindrical
form.
9. The method according to claim 7, wherein a local strain caused
by the flanging role is at its lowest at the at an edge of the
flange and has a gradient from the edge of the flange to a
beginning of the flange.
10. The method according to claim 7, wherein the symmetrical axle
of the flanging role is oriented in a substantially vertical
position relative to a surface of the flanging bed.
11. The method according to claim 10, wherein the symmetrical axle
of the flanging role is turned anti-clockwise by a traveling angle
.beta. in relation to a vertical of a translational directions.
12. The method according to claim 7, wherein the symmetrical axle
of the flanging role is substantially parallel to a surface of the
flanging bed.
13. The method according to claim 12, wherein the symmetrical axle
of the flanging role is turned clockwise in relation to the
vertical of the translational direction v1 by a traveling angle
.beta..
14. The method according to claim 7, wherein the flanging role is
guided with a translational velocity v1 during the pre-flanging,
and the translational velocity v1 has a range of about 1000
mm/s.ltoreq.v1.ltoreq.1600 mm/s.
15. (canceled)
Description
[0001] The invention relates to a crimping device comprising a
multiaxial industrial robot, in particular an industrial robot
which has a crimping tool with a crimping head on its hand and at
least one crimping roller located on the crimping head.
[0002] Such a crimping device is known, for example, from DE-U-299
10 871. The robot-guided crimping tool disclosed therefore has a
crimping roller by which means a crimping flange is folded over and
pressed down on a workpiece. The pre- and finish-crimping can
optionally take place in a plurality of operations.
[0003] When using such a crimping device, however, the formation of
folds in the material of the flange frequently occurs during the
pre-crimping. These folds must be eliminated to prepare a
defect-free surface in the finish-crimping step, which however is
typically only possible in a restricted scope and additionally
requires expenditure.
[0004] It is therefore the object of the invention to provide a
crimping device, which allows fold-free crimping of workpieces in
the simplest possible manner.
[0005] In addition, it is a further object of the present invention
to provide a method for roll crimping of workpieces, by which means
the formation of folds can be reliably avoided.
[0006] According to the invention, this object is achieved with the
subject matter of the independent patent claims.
[0007] Advantageous further developments of the invention are the
subject matter of the dependent claims.
[0008] An inventive crimping device comprises a crimping bed
provided for receiving a workpiece and a multiaxial manipulator, in
particular an industrial robot, which has a crimping tool with at
least one crimping roller on its hand. At least parts of the
crimping roller have the form of a cone or a truncated cone having
an apex, an axis of symmetry running through said apex, and an
opening angle .alpha., wherein for the opening angle .alpha. of the
cone it holds that 180.degree.>.alpha..gtoreq.140.degree..
[0009] The invention starts from the consideration that fold
formation during pre-crimping should be avoided a priori. As has
been shown in experiments and in simulations, fold formation can be
attributed to local elongations of the material, particularly in
the vicinity of the flange edge, during pre-crimping.
[0010] Particularly in the area of the flange edge, the local
elongation of the material should therefore be kept relatively low.
The elongation which comes about due to the flange material
"winding round" the crimping roller, can be reduced particularly in
the area of the flange edge by selecting the crimping roller to be
a conical one instead of the conventional cylindrical crimping
roller, wherein "conical" is used here and subsequently as an
abbreviation and means a crimping roller which either has the shape
of a full cone or that of a truncated cone or which has the shape
of a full cone or that of a truncated cone at least in some
areas.
[0011] As a result of its straight guidance by the robot, such a
conical crimping roller does not roll on the entire circumferential
surface of the cone but strictly speaking, only on a circle line.
The other areas of the circumferential surface exert a
significantly lower pressing pressure on the flange. Thus, the
pressing pressure has a gradient along a section on the
circumferential surface between the base area and the apex of the
cone, which is suitable for preventing local elongations of the
flange edge.
[0012] As has been found, the strength of the gradient in the
pressing pressure is optimal when the opening angle .alpha. of the
cone is at least 1400, preferably at least 1600.
[0013] In addition to the opening angle of the cone, further
parameters such as, for example, the diameter of the crimping
roller are important for avoiding local elongations. The base area
of the conical crimping roller advantageously has a diameter d of
at least 60 mm.
[0014] In one exemplary embodiment of the invention, the conical
crimping roller is provided as a pre-crimping roller and a
cylindrical further crimping roller is provided as the finish
crimping roller. However, the crimping roller can also be
configured such that it has a conical or frustro-conical region and
in addition, a cylindrical region so that it can be used as a
pre-crimping roller and as a finish-crimping roller.
[0015] The crimping roller is advantageously disposed fixedly on a
driven shaft of a drive, by which means the crimping roller can be
driven at a defined rotational speed during the crimping. The
direction of rotation of the crimping roller takes place in the
direction of the traveling industrial robot, wherein the rotational
speed of the crimping roller is higher than the traveling speed of
the industrial robot.
[0016] The friction between the crimping flange to be crimped and
the surface of the crimping rollers machining the crimping flange
should be as high as possible. "Spinning" of the driven crimping
rollers on the crimping flange should be avoided under all
circumstances. In this case, it has been found to be an expedient
embodiment for the crimping rollers to make the crimping rollers of
a hard metal core, preferably a steel, with a hard rubber cladding
located thereon. The hard rubber cladding can be vulcanized
thereon.
[0017] The inventive apparatus has the advantage that the flange
material is less severely locally elongated than by conventional
crimping rollers due to the optimized conical geometry of the
crimping roller. As a result, fold formations on the workpiece
occur less frequently and also expensive efforts to reduce the
folding during finish crimping or a reduction in the translational
speed can be dispensed with.
[0018] According to the present invention, a method for the roll
crimping of metal parts comprises the following steps: firstly, a
workpiece to be crimped is provided with a flange located on a
crimping bed. The flange is pre-crimped with a pre-crimping roller
guided by a multiaxial manipulator, for example, an industrial
robot, the pre-crimping roller has the shape of a cone or truncated
cone, having an axis of symmetry, an apex and an opening angle
.alpha., and the opening angle .alpha. of the cone is at least
140.degree.. The flange is then finish-crimped, preferably with a
cylindrical finish crimping roller.
[0019] Due to the optimized conical geometry of the crimping
rollers, less severe local elongations than in conventional
methods, which could lead to fold formation, occur particularly in
the proximity of the flange edge. In this case, there are two
possibilities for the guidance of the crimping roller:
[0020] Either the axis of symmetry of the conical crimping roller
is approximately perpendicular to the plane of the crimping bed
during the crimping process. In this case, "approximately
perpendicular" means that the axis of symmetry passes through the
plane of the crimping bed at an angle of greater than
45.degree..
[0021] In this case, the axis of symmetry of the pre-crimping
roller is advantageously turned through an angle g in the
counterclockwise direction toward the perpendicular to the
direction of translation.
[0022] However, the axis of symmetry of the conical crimping roller
can also be approximately parallel to the plane of the crimping bed
during the crimping process. In this case, "approximately parallel"
means that the axis of symmetry passes through the plane of the
crimping bed at an angle of less than 45.degree..
[0023] In this second case, the axis of symmetry of the
pre-crimping roller is advantageously turned through an angle g in
the clockwise direction toward the perpendicular to the direction
of translation.
[0024] Before the beginning of the pre-crimping, the flange angle
.gamma. between the flange and the crimping bed and therefore the
plane of the workpiece should therefore be at most 90.degree..
[0025] The translational speed v.sub.1 at which the crimping roller
is guided during the pre-crimping is advantageously between 1000
mm/s and 1600 mm/s. A plurality of pre- or finish crimping steps
can be provided both for the pre- and finish-crimping of the
flange.
[0026] The crimping device is particularly suitable for the roll
crimping of vehicle parts such as automobile doors, hoods, and
tailgates.
[0027] Exemplary embodiments of the invention are explained in
detail hereinafter with reference to the appended figures.
[0028] FIG. 1 shows in schematic side view a crimping device with
an industrial robot and a crimping tool with a driven crimping
roller;
[0029] FIG. 2 shows schematically a crimping roller according to a
first embodiment;
[0030] FIG. 3 shows schematically a crimping roller according to a
second embodiment;
[0031] FIG. 4 shows schematically a crimping roller according to a
third embodiment;
[0032] FIG. 5 shows schematically a side view of the crimping
roller during the crimping process;
[0033] FIGS. 6 and 7 show two possibilities for carrying out the
roll crimping. In this case,
[0034] FIG. 6a shows schematically a side view of a first
possibility;
[0035] FIG. 6b shows schematically the first possibility from
another perspective;
[0036] FIG. 7a shows schematically a side view of a second
possibility;
[0037] FIG. 7b shows schematically the second possibility from
another perspective
[0038] The same parts are provided with the same reference numerals
in all the figures.
[0039] FIG. 1 shows in a schematic diagram a crimping device 1,
which principally consists of a six-axis industrial robot 2 and a
crimping tool 5.
[0040] The crimping tool 5 is moved by the industrial robot 2 with
respect to a workpiece 10 having one or more crimping flanges 11,
which is disposed in a fixed position on a framework and clamped
there on a crimping bed 12.
[0041] The framework can also be designed as a rotary table (not
shown), on which the crimping bed 12 is mounted, wherein the rotary
table is turned in the direction opposite to the direction of
travel of the robot and for this purpose is incorporated in the
controller of the industrial robot 2 or accesses a common
controller.
[0042] The industrial robot shown in FIG. 1 has six axes of
rotation. However, the number of axes can be smaller or larger. The
industrial robot 2 has a robot controller 13, by which means its
movements, and optionally also the process sequence of the
crimping, can be controlled and regulated. To this end, a movement
sequence of the robot 2 and the crimping tool 5 derived from the
contour of the clamping flanges is programmed in the robot
controller 13 and the CAD and/or CAM data of the workpiece 10 is
stored in a random access memory.
[0043] The industrial robot 2 has a rocker arm and an outrigger 3,
having a robot hand 4 with one or more movement axes disposed at
its front end. On the driven side, the robot hand 4 has a hand
flange to which the crimping tool 5 is flange-mounted.
[0044] The crimping tool 5 shown in FIG. 1 has a crimping roller 6.
The crimping roller 6 is firmly fastened to a driven shaft 7. The
driven shaft 7 is in communication with a transmission 8, which is
flange-mounted to a drive motor 9. Transmission 8 and drive motor 9
are located inside the crimping tool 5.
[0045] In order to execute the roll crimping on the workpiece 10,
the industrial robot 2 is set in motion by the controller 13 and
travels around the crimping flange 11 at a speed v.sub.1. At the
same time the crimping roller 6 is pressed onto the crimping flange
so that the crimping roller 6 folds the crimping flange downward.
The crimping roller 6 is thereby set in rotational movement, which
is effected via the drive motor 9, the transmission 8, and
ultimately the driven shaft 7. The rotational movement of the
crimping roller 6 is effected in the direction of travel of the
robot 2 along the outer contour of the crimping flange 11.
[0046] The rotational speed v.sub.2 or the rotational speed of the
crimping roller 6 is in this case greater than the speed of travel
v.sub.1 of the moving robot 2. Accordingly, it holds that
v.sub.2>v.sub.1. The speed v.sub.1 of the industrial robot 2 is
typically between 1000 mm/s and 1600 mm/s.
[0047] As a result, the workpiece in the area of the crimping
flange 11 is pulled by the crimping roller 6 slightly in the
direction opposite to the direction of travel of the robot 2. Any
bunching of the workpiece 10 in the area of the crimping flange 11
is thereby reduced.
[0048] The industrial robot 2 has a robot controller 13, which
measures and adjusts the movements and the entire process sequence
of the roll crimping executed. The robot controller 13 is designed
as a computer-aided controller with one or more processors, a
plurality of interfaces for input and output of data, and a
plurality of memories for operating, process, and other relevant
data.
[0049] The track course and the corresponding movement sequence of
the industrial root 2 and of the crimping tool 8 are programmed in
the robot controller 13 and stored in a random access memory.
[0050] In the area of its crimping head 15, the crimping device 1
has a measuring device 20 which measures the crimping values
detected from the crimping process. The measuring device 20 is
connected to the robot controller 13 via a line 19. The robot
controller 13 is in turn connected to the industrial robot 2 by
means of a line 21.
[0051] The measuring device 20 in particular measures the
rotational speed and the pressing pressure of the crimping roller 6
during the roll crimping and readjusts this by means of a desired
value/actual value comparison. The readjustment in particular takes
account of the exact adjustment of the rotating crimping roller
6.
[0052] Since the speed of travel of the robot 2 during travel
around and processing of the workpiece 11 can be different, the
rotational speed of the driven crimping roller 6 must be matched to
this. This matching is also carried out via the robot controller
13, in which the rotational speed of the crimping roller 6 is
adjusted by means of the program data stored in the random access
memory depending on the speed of travel of the robot 2.
[0053] In order to effectively prevent the bunching of the
workpiece 10 in the area of the crimping flange 11, which leads to
fold formation at the crimping flange 11, the crimping roller 6 has
a special geometry.
[0054] FIGS. 2, 3, and 4 show schematically alternative embodiments
of the crimping roller 5.
[0055] The crimping roller 6 according to FIG. 2 has the form of a
cone having a circumferential surface 14 and a base area 16. The
geometry of the cone is characterized by its opening angle .alpha.
and the diameter d of its base area 16. An opening angle .alpha. of
at least 140.degree. is particularly favorable for avoiding fold
formation. The diameter d is at least 60 mm.
[0056] The crimping roller 5 can either have the form of a full
cone, as shown in FIG. 2. However, it can also have the form of a
truncated cone, as shown in FIG. 3. The conical or frustro-conical
roller 6 is used for pre-crimping the workpiece 10. A cylindrical
finish-crimping roller, not shown, can be used, for example, for
the finish-crimping.
[0057] However, the operations of pre- and finish crimping can also
be executed with a single crimping roller 6. For this, the crimping
roller according to FIG. 4 has a conical region 25 for pre-crimping
and a cylindrical region 23 for finish-crimping. Both the pre- and
the finish-crimping can be executed in several passes.
[0058] FIG. 5 shows schematically a side view of the conical
crimping roller 6 and the crimping flange 11 during the crimping
process.
[0059] The crimping roller 6 is set so that in a first region 18,
it is pressed with relatively high pressing pressure onto the
crimping flange 11 and nestles closely against this flange. In a
second region 22, which lies closer to the apex, the radius of the
crimping roller 6 is significantly smaller as a result of its
conical geometry and the circumferential surface 14 of the cone
does not nestle so closely against the crimping flange 11 in this
second region 22. The crimping roller 6 does roll on its entire
circumferential surface 14 but strictly speaking, only on a circle
on the circumferential surface.
[0060] Local elongations, which can lead to fold formation in the
crimping flange 11, come about due to the "winding around" of the
flange material around the crimping roller 6. As a result of the
smaller radius in the second region 22, which lies closer to the
apex, the cone geometry results in a particular small local
elongation in the proximity of the flange edge 24.
[0061] The flange 11 forms a flange angle .gamma. with the plane of
the workpiece 10. Before the beginning of the pre-crimping, this
flange angle .gamma. should be at most 90.degree..
[0062] FIGS. 6 and 7 show two different possibilities for guiding
the crimping roller 6.
[0063] In FIG. 6a the axis of symmetry 27 of the conical crimping
roller 6 lies approximately parallel to the plane of the crimping
bed 12 and therefore substantially also to the surface of the
workpiece 10. The apex 26 is facing the workpiece 10.
"Approximately parallel" means in this case that the axis of
symmetry 27 passes through the plane of the crimping bed 12 at an
angle of less than 45.degree..
[0064] In this alignment of the crimping roller 6, the angle
.beta., as shown in FIG. 6b, according to the mathematical
definition should be negative, that is, it should have come about
through a clockwise rotation from the perpendicular 28 to the
direction of translation v.sub.1.
[0065] In the alternative possibility according to FIG. 7a, the
axis of symmetry 27 is approximately perpendicular to the plane of
the crimping bed. "Approximately perpendicular" means in this case
that the axis of symmetry 27 passes through the plane of the
crimping bed 12 at an angle of greater than 45.degree..
[0066] In this alternative alignment of the crimping roller 6, the
angle .beta., as shown in FIG. 7b, according to the mathematical
definition should be positive, that is, it should have come about
through a counterclockwise rotation from the perpendicular 28 to
the direction of translation v.sub.1.
REFERENCE LIST
[0067] 1 Crimping device [0068] 2 Industrial root [0069] 3
Outrigger [0070] 4 Robot hand [0071] 5 Crimping device [0072] 6
Crimping roller [0073] 7 Driven shaft [0074] 8 Transmission [0075]
9 Drive motor [0076] 10 Workpiece [0077] 11 Crimping flange [0078]
12 Crimping bed [0079] 13 Robot controller [0080] 14
Circumferential surface [0081] 15 Crimping head [0082] 16 Base area
[0083] 17 First region [0084] 18 Line [0085] 19 Measuring device
[0086] 20 Line [0087] 21 Second region [0088] 22 Cylindrical region
[0089] 23 Flange edge [0090] 24 Conical region [0091] 25 Apex
[0092] 26 Axis of symmetry [0093] 28 Direction perpendicular to
v.sub.1 [0094] .alpha. Opening angle [0095] .beta. Angle of travel
[0096] .gamma. Flange angle [0097] v.sub.1 Translational speed
* * * * *