U.S. patent application number 11/074809 was filed with the patent office on 2005-10-06 for roller type hemming apparatus.
This patent application is currently assigned to TESCO Engineering Inc.. Invention is credited to Toeniskoetter, James B..
Application Number | 20050217339 11/074809 |
Document ID | / |
Family ID | 35052746 |
Filed Date | 2005-10-06 |
United States Patent
Application |
20050217339 |
Kind Code |
A1 |
Toeniskoetter, James B. |
October 6, 2005 |
Roller type hemming apparatus
Abstract
A roller type hemming apparatus includes a support member having
a slide bore, a compression pad of a block-like shape, and a slide
member. The compression pad and the slide member are received in
the slide bore such that the compression pad is intermediate the
support member and the slide member. The compression pad and slide
member are preloaded therein. The apparatus further includes a stop
member having a radially projecting head. The stop member fastens
the compression pad and the slide member to the support member. The
apparatus also includes a hem roller. The slide member includes a
flange projecting from an outer surface of the slide member and the
hem roller is rotatably mounted on the flange. The movement of the
slide member is tempered during the application of an abrupt
compressive force.
Inventors: |
Toeniskoetter, James B.;
(Rochester Hills, MI) |
Correspondence
Address: |
Christopher J. Fildes
Fildes & Outland, P.C.
Suite 2
20916 Mack Avenue
Grosse Pointe Woods
MI
48236
US
|
Assignee: |
TESCO Engineering Inc.
|
Family ID: |
35052746 |
Appl. No.: |
11/074809 |
Filed: |
March 8, 2005 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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60557601 |
Mar 30, 2004 |
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Current U.S.
Class: |
72/220 |
Current CPC
Class: |
B21D 39/023 20130101;
B21D 39/021 20130101 |
Class at
Publication: |
072/220 |
International
Class: |
B21D 039/02 |
Claims
What is claimed is:
1. A roller type hemming apparatus comprising: a support member
having a slide bore; a compression pad of a block-like shape; a
slide member; said compression pad and said slide member being
received in said slide bore such that said compression pad is
intermediate said support member and said slide member and being
preloaded therein; a stop member having a radially projecting head,
said stop member fastening said compression pad and said slide
member to said support member; and a hem roller; said slide member
including a flange projecting from an outer surface of said slide
member, said hem roller being rotatably mounted on said flange;
whereby the movement of the slide member is tempered during the
application of an abrupt compressive force.
2. The roller type hemming apparatus of claim 1, wherein said slide
member flange includes an aperture, said hem roller includes a
central opening and a bushing therein said central opening, and
said apparatus includes a shaft extending through said bushing and
said flange aperture.
3. The roller type hemming apparatus of claim 2, further including
a nut for securing said shaft to said slide member flange.
4. The roller type hemming apparatus of claim 2, further including
a collar on said shaft disposed between said hem roller and said
slide member flange.
5. The roller type hemming apparatus of claim 1, wherein said stop
member is a bolt having a central shank portion and a threaded
portion on an end opposite said radially projecting head.
6. The roller type hemming apparatus of claim 5, wherein said slide
member includes a threaded hole on an inner surface thereof for
receiving the threaded portion of said stop member.
7. The roller type hemming apparatus of claim 5, wherein said shank
portion of said stop member passes through said compression
pad.
8. The roller type hemming apparatus of claim 1, wherein said
support member includes a circular opening for receiving said stop
member, said circular opening being smaller in diameter than the
head of said stop member and extending from an outer surface of
said support member to said support member slide bore.
9. The roller type hemming apparatus of claim 8, wherein said
support member circular opening is coaxially formed in relation to
said support member slide bore.
10. The roller type hemming apparatus of claim 1, wherein said
support member slide bore has a square cross-sectional shape.
11. The roller type hemming apparatus of claim 10, wherein slide
member has a square cross-sectional shape smaller than said cross
section of said support member.
12. The roller type hemming apparatus of claim 1, further including
a spacer plate removably fastened to an outer surface of said
support member between said outer surface and said stop member
head.
13. The roller type hemming apparatus of claim 12, wherein said
spacer plate includes an opening for receiving said stop member,
said opening being smaller in diameter than said stop member
head.
14. The roller type hemming apparatus of claim 1, wherein said
compression pad is a urethane block.
15. The roller type hemming apparatus of claim 1, wherein said
apparatus is adapted for operable connection to a work arm of a
multi-axis robot.
16. The roller type hemming apparatus of claim 15, wherein said
apparatus is fastened to a forward end of a hand of said robot.
17. A method of roller hemming, the method comprising the step of:
providing a roller type hemming apparatus including: a support
member having a slide bore; a compression pad of a block-like
shape; a slide member; said compression pad and said slide member
being received in said slide bore such that said compression pad is
intermediate said support member and said slide member and being
preloaded therein; a stop member having a radially projecting head,
said stop member fastening said compression pad and said slide
member to said support member; and a hem roller; said slide member
including a flange projecting from an outer surface of said slide
member, said hem roller being rotatably mounted on said flange;
whereby the movement of the slide member is tempered during the
application of an abrupt compressive force.
Description
CROSS REFERENCE TO RELATED APPLICATION
[0001] This application claims the priority of U.S. Provisional
Application No. 60/557,601 filed Mar. 30, 2004.
TECHNICAL FIELD
[0002] This invention relates to a roller type hemming apparatus
for edge hemming vehicle closure panels, such as hemming of door
panels, hood panels, and decklid panels.
BACKGROUND OF THE INVENTION
[0003] It is known in the art relating to hemming that roller
hemmers can be used to hem the edges of metal, for example
aluminum, automotive parts such as door panels, hood panels, and
decklid panels.
[0004] Conventionally, a hemming apparatus may be mounted to a
multi-axis controllable robot and may include a hem roller carried
by a support. The conventional hemming apparatus is adapted for
hemming a bent portion of a workpiece, such as a door panel,
positioned on a hemming die, by rotating the hem roller under
pressure along the bent portion. The conventional roller type
hemming apparatus can thus be used for continuous hemming along the
contour of the edge of the workpiece.
[0005] In order to achieve good hemming with such a conventional
hemming apparatus, however, the robot must move the hem roller
along the edge of the workpiece at a constant distance from the
hemming die. The robot is not composed of a perfectly rigid body,
and when the hem roller is positioned against the edge of the
workpiece, the robot may be deflected by its own resiliency or by a
repulsive force exerted by the edge of the workpiece itself. This
results in an interrupted pressing force applied by the hem roller
and therefore imperfect hemming of the workpiece. Springs have been
disposed in the hemming roller support to compensate for the
interrupted pressing force, but alone springs have proven
inefficient and unpredictable.
[0006] Further, the edge of a workpiece to be hemmed may also have
a complex configuration. This makes it difficult for a conventional
hemming apparatus to achieve adequate hemming of the workpiece.
SUMMARY OF THE INVENTION
[0007] The present invention provides a roller type hemming
apparatus which includes a hem roller that can accurately follow up
the configuration of a bent portion of a workpiece to be hemmed and
more accurately and uninterruptably apply a consistent hemming
force.
[0008] The present invention also provides a roller type hemming
apparatus wherein deflection of the hem roller is limited while the
hemming force is maintained by a compression pad having a
predetermined compressible constant.
[0009] More particularly, a roller type hemming apparatus includes
a support member having a slide bore, a compression pad of a
block-like shape, and a slide member. The compression pad and the
slide member are received in the slide bore such that the
compression pad is intermediate the support member and the slide
member. The compression pad and slide member are preloaded therein.
The apparatus further includes a stop member having a radially
projecting head. The stop member fastens the compression pad and
the slide member to the support member. The apparatus also includes
a hem roller. The slide member includes a flange projecting from an
outer surface of the slide member and the hem roller is rotatably
mounted on the flange. The movement of the slide member is tempered
during the application of an abrupt compressive force.
[0010] In a specific embodiment, the slide member flange may
include an aperture, the hem roller may include a central opening
and a bushing therein the central opening, and the apparatus may
include a shaft extending through the bushing and the flange
aperture. The apparatus may also include a nut for securing the
shaft to the slide member flange and a collar on the shaft disposed
between the hem roller and the slide member flange.
[0011] The stop member may be a bolt having a central shank portion
and a threaded portion on an end opposite the radially projecting
head. The slide member may include a threaded hole on an inner
surface thereof for receiving the threaded portion of the stop
member. The shank portion of the stop member may pass through the
compression pad. The support member may include a circular opening
for receiving the stop member, the circular opening being smaller
in diameter than the head of the stop member and extending from an
outer surface of the support member to the support member slide
bore. The support member circular opening may be coaxially formed
in relation to the support member slide bore.
[0012] The support member slide bore may have a square
cross-sectional shape. The slide member may have a square
cross-sectional shape smaller than the cross section of the support
member. The apparatus may further include a spacer plate removably
fastened to an outer surface of the support member between the
outer surface and the stop member head. The compression pad may be
a urethane block. The apparatus may be adapted for operable
connection to a work arm of a multi-axis robot and may be fastened
to a forward end of a hand of the robot.
[0013] With the above construction, as the hem roller is
displaceable in a direction corresponding to the pressing direction
of the robot hand, deflection of the robot hand or any difference
between the traveling path of the robot hand and the peripheral
contour of the workpiece can be absorbed, permitting the hem roller
to accurately follow the bent portion of the workpiece.
[0014] These and other features and advantages of the invention
will be more fully understood from the following detailed
description of the invention taken together with the accompanying
drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] In the drawings:
[0016] FIG. 1 is an environmental view of a roller type hemming
apparatus in accordance with the present invention hemming a
workpiece with the aid of a robot hand;
[0017] FIG. 2 is a sectional view of a hem roller support of the
roller type hemming apparatus of FIG. 1;
[0018] FIG. 3 is a perspective view illustrating a teaching
operation; and
[0019] FIG. 4 is a perspective view illustrating a hemming
operation.
DETAILED DESCRIPTION OF THE INVENTION
[0020] Referring now to the drawings in detail and to FIG. 1 in
particular, a roller type hemming apparatus 10 in accordance with
the present invention is adapted for operable connection to a work
arm, such as a multi-axis controllable robot hand 12, to which a
predetermined traveling path is preliminarily taught. The roller
type hemming apparatus 10 includes a hem roller support 14 mounted
on a forward end of the robot hand 12, and a hem roller 16
displaceably supported by the hem roller support 14 to be pressed
against a workpiece W.
[0021] The workpiece W is, for example, a door panel composed of an
outer panel Wo and an inner panel Wi. The outer panel Wo has a
peripheral portion preliminarily bent upwardly substantially at
right angles, and the inner panel Wi has a peripheral stepped
portion extending outwardly. The outer panel Wo and the inner panel
Wi are placed on a lower die 18 with the stepped portion of the
inner panel Wi arranged along the inside of the bent portion of the
outer panel Wo. The lower die 18 has an upper surface constituting
a forming surface 20 and is placed on a common base 22 on which the
hemming apparatus 10 is placed at a predetermined distance away
from the lower die 18. The workpiece W is placed on the forming
surface 20 of the lower die 18 and is secured thereto by fixtures
24.
[0022] As the robot hand 12 is well known in the art, its
description will be omitted, and the hem roller support 14 and the
hem roller 16 will be described in detail.
[0023] As shown in FIG. 2, a support member 26 is attached to the
forward end of the robot hand 12 by fasteners such as bolts 28. The
support member 26 has a slide bore 30. The slide bore 30 may have a
square cross-sectional shape. A compression pad 32 of a block-like
shape, such as a urethane block or similar, is inserted into the
support member 26 slide bore 30. Then slide member 34 is slidably
inserted in the support member 26. The slide member 34 may be a
substantially prismatic member slidably inserted in the slide bore
30 of the support member 26. The slide member 34 may also have a
square cross-sectional shape smaller than the cross-section of the
support member 26. A stop member 36 having a radially projecting
head 38 fastens the compression pad 32 and the slide member 34 to
the support member 26.
[0024] The slide member 34 includes a flange 40 projecting
downwardly (as viewed in FIG. 2) from an outer surface 42 of the
slide member. The hem roller 16 is rotatably mounted on the flange
40. The slide member flange 40 may include an aperture 44 of a
predetermined diameter extending through a thickness direction
thereof. The hem roller 16 may include a central opening 46 and a
bushing 48 therein. The bushing 48 may be made from a metallic,
plastic, ceramic or similar material. The hem roller 16 may then be
mounted on the flange by a shaft 50 extending through the bushing
48 and the flange aperture 44. A nut 52 secures the shaft 50 to the
flange 40. A collar 54 may be disposed between the hem roller 16
and the slide member flange 40.
[0025] The compression pad 32 may have a predetermined compression
constant. The compression pad 32 has upper and lower ends held in
abutment against a lower surface of the support member 26 and an
upper surface of the slide member 34, respectively, so as to urge
the slide member 34 downwardly (as viewed in FIG. 2) in the support
member 26. The movement of the preloaded slide member 34 is thereby
tempered by the compression pad 32 during the application of an
abrupt compressive force, such as a force applied to the hem roller
16.
[0026] The stop member 36 may be a bolt having a central shank
portion 56 and a threaded portion 58 on an end opposite the
radially projecting head 38. The slide member 34 may include a
threaded hole 60 on an inner surface thereof for receiving the
threaded portion 58 of the stop member 36. The shank portion 56 of
the stop member may pass through the compression pad 32. The
support member 26 may include a circular opening 62 for receiving
the stop member 36. The circular opening 62 is smaller in diameter
than the head 38 of the stop member 36 and extends from an outer
surface of the support member 26 to the support member slide bore
30. The circular opening 62 may also be coaxially formed in
relation to the support member slide bore 30. A spacer plate 64 of
a predetermined thickness t may be removably fastened by a set
screw 66 to an outer surface of the support member between the
outer surface and the stop member head 38. The spacer plate 64 may
include an opening 68 for receiving the stop member 36, the opening
being smaller in diameter than the stop member head 38.
[0027] A teaching procedure for the robot hand 12 will now be
described with reference to FIG. 3. The spacer plate 64 is
preliminarily interposed between the support member 26 and the head
38 of the stop member 36, as shown in FIG. 3. This causes the slide
member 34 and consequently the hem roller 16 to be displaced
upwardly with respect to the support member 26 or in a direction
away from the forming surface 20 of the lower die 18, by a distance
corresponding to the thickness t of the spacer plate 64.
[0028] Then, the hem roller 16 is moved along the forming surface
20 of the lower die 18 in abutment therewith so as to teach the
robot hand 12 a virtual traveling path defined by the forming
surface 20. The position of the hem roller 16 with respect to the
forming surface 20 at this time is shown as teaching level LT.
After the teaching operation has been completed, the spacer plate
64 is removed to return the slide member 34 to a free position
where the head 38 of the stop member 36 is in abutment against the
upper surface of the support member 26.
[0029] As described above, in teaching the robot hand 12, the
virtual traveling path temporarily defined by the forming surface
20 of the lower die 18 is taught to the robot hand 12, so that the
robot hand 12 is shifted in the traveling path thus taught to
perform a hemming operation.
[0030] During the hemming operation, the workpiece W is placed on
the forming surface 20 of the lower die 18, as shown in FIG. 4, so
that the hemming level LH which defines an ideal traveling path of
the hem roller 16 is deviated by a distance .alpha. from the
teaching level LT in a direction away from the forming surface 20
of the lower die 18. The distance .alpha. corresponds to thickness
.delta. of the workpiece W which is the total of twice the
thickness of the outer panel Wo and the thickness of the inner
panel Wi. Here, it is to be noted that the robot hand 12 is so
moved as to locate the hem roller 16 at the teaching level LT.
However, the hem roller 16 cannot be located at the level LT since
the spacer plate 64 is removed during the hemming operation, and
since the workpiece W is placed between the hem roller 16 and the
lower die 18. Then, the compression pad 32 provided between the
support member 26 and the slide member 34 is contracted to the
amount of difference in height of the hem roller 16, that is, the
total of the thickness t of the spacer plate 64 and the thickness 6
of the workpiece W. As the compression pad 32 is contracted, the
hem roller 16 is pressed toward the lower die 18 by a repulsive
force of the contracting compression pad 32. Specifically, the
difference between the teaching level LT and the hemming level LH
is absorbed by contraction of the compression pad 32, so that a
good hemming operation may be performed even though the virtual
traveling path temporarily defined by the forming surface 20 of the
lower die 18 has been taught to the robot hand 12.
[0031] Further, during the hemming operation, the hem roller 16 is
pressed with a predetermined pressing force against the bent
portion of the workpiece W, and a repulsive force of the bent
portion causes the robot hand 12 to be deflected in a direction
away from the bent portion. As, in teaching to the robot hand 12,
the position of the slide member 34 has been displaced with respect
to the support member 26 by a distance corresponding to the
thickness t of the spacer plate 64, the hem roller 16 can be
maintained on the hemming level LH, even when the robot hand 12 is
deflected within the range limited by the maximum distance
corresponding to the thickness t. Thus, the deflection of the robot
hand 12 is absorbed and the hem roller 16 is always held on the
hemming level LH, permitting the pressing force of the hem roller
16 to be maintained at a proper value to achieve good hemming.
[0032] As described above, as the slide member 34 and consequently
the hem roller 16 is displaceable with respect to the support
member 26 and consequently the robot hand 12, deflection of the
robot hand 12, or the difference in the traveling path of the hem
roller 16 with respect to the workpiece W can be absorbed. This
permits the hem roller 16 to constantly follow up the bent portion
of the workpiece W exactly and to be constantly pressed with a
proper pressing force for good hemming.
[0033] Further, as the hem roller 16 is displaceable with respect
to the robot hand 12, the teaching procedure can be readily
performed, using the forming surface 20 of the lower die 18 as a
virtual traveling path.
[0034] It is essential to the present invention that the hem roller
16 be displaceable with respect to the robot hand 12, the position
of the hem roller 16 being controlled by the position controlling
means of the hem roller support 14. Therefore, teaching of the
robot hand 12 can be readily carried out, and during the hemming
operation, the position of hem roller 16 can be constantly held on
the hemming level LH to achieve good hemming at all times.
[0035] Thus, in the hemming apparatus of the present invention, as
the hem roller is rotated under a proper pressing force in an
accurate traveling path along the peripheral contour of a
workpiece, hemming can always be satisfactorily carried out. In
addition, teaching of the robot hand can be readily carried out in
the present invention.
[0036] Although the invention has been described by reference to a
specific embodiment, it should be understood that numerous changes
may be made within the spirit and scope of the inventive concepts
described. Accordingly, it is intended that the invention not be
limited to the described embodiment, but that it have the full
scope defined by the language of the following claims.
* * * * *