U.S. patent application number 12/873602 was filed with the patent office on 2012-03-01 for cantilevered flange die insert for a rotary cam having a reduced diameter portion.
This patent application is currently assigned to FORD GLOBAL TECHNOLOGIES, LLC. Invention is credited to John W. Davis, Joseph H. Fornasiero.
Application Number | 20120047986 12/873602 |
Document ID | / |
Family ID | 45695345 |
Filed Date | 2012-03-01 |
United States Patent
Application |
20120047986 |
Kind Code |
A1 |
Davis; John W. ; et
al. |
March 1, 2012 |
Cantilevered Flange Die Insert for a Rotary Cam Having a Reduced
Diameter Portion
Abstract
A sheet metal forming die set includes a rotary cam that is
received in a cavity of one of the dies. The rotary cam has a
cylindrical body portion and a bullet nose portion that is smaller
in diameter than the body portion. A cantilevered insert is
provided on the die adjacent to the bullet nose portion.
Inventors: |
Davis; John W.; (Ypsilanti,
MI) ; Fornasiero; Joseph H.; (Brighton, MI) |
Assignee: |
FORD GLOBAL TECHNOLOGIES,
LLC
Dearborn
MI
|
Family ID: |
45695345 |
Appl. No.: |
12/873602 |
Filed: |
September 1, 2010 |
Current U.S.
Class: |
72/452.2 |
Current CPC
Class: |
B21D 19/086 20130101;
B21D 19/08 20130101 |
Class at
Publication: |
72/452.2 |
International
Class: |
B21D 22/08 20060101
B21D022/08 |
Claims
1. A die set for forming a panel in a press comprising: an upper
die; a lower die cooperates with the upper die; a rotary fill cam
is assembled to the lower die, the rotary fill cam is pivoted about
an axis, the rotary fill cam having a cylindrical portion and a
reduced diameter portion on at least one end; and a cantilevered
flange die insert is secured to the lower die to extend over the
reduced diameter portion of the rotary fill cam filling the space
between the upper die and the reduced diameter portion of the
rotary fill cam.
2. The die set of claim 1 wherein the reduced diameter portion of
the rotary fill cam is formed in the shape of a bullet nose that is
provided on one end of the cylindrical portion.
3. The die set of claim 1 wherein the rotary fill cam defines a
first extended forming surface and the cantilevered flange die
insert defines a second extended forming surface of the lower
die.
4. The die set of claim 3 wherein the first extended forming
surface of the rotary fill cam is disposed adjacent the second
extended forming surface of the lower die surface when the panel is
formed in the press.
5. A rotary fill cam that is operatively assembled to a die, the
rotary fill cam comprising: a body portion that is assembled to the
die to pivot within the die; a bullet nose portion that is provided
on one end of the body portion and that pivots with the body
portion; and wherein the die has a cantilevered flange die insert
that over hangs the bullet nose portion of the rotary fill cam and
is supported by the bullet nose portion.
6. The rotary fill cam of claim 5 wherein the body portion is
cylindrical.
7. The rotary fill cam of claim 6 wherein the cylindrical body
portion has an axis about which the body portion pivots, wherein
the outer periphery of the body portion is disposed at a radius R
from the axis and wherein the bullet nose portion defines a forming
surface that is disposed at a distance from the axis that is less
than R.
8. The rotary fill cam of claim 5 wherein the die has a die
surface, and the bullet nose portion defines a first extended
portion of the die surface.
9. The rotary fill cam of claim 8 wherein the cantilevered flange
die insert defines a second extended portion of the die
surface.
10. A die assembly used to form a panel comprising: a die that
defines a cavity; a rotary cam received in the cavity, the rotary
cam having a cylindrical portion and having a re-entrant portion; a
cantilevered extension attached to the die and extending into the
re-entrant portion; a first forming surface provided on the
cantilevered extension; and a second forming surface provided on
the rotary cam that is rotated to a position adjacent to the first
forming surface to form a portion of the panel.
11. The die assembly of claim 10 wherein the re-entrant portion has
a partially spherical convex surface and the extension has a
partially spherical concave surface that is assembled over the
partially spherical convex surface.
12. The die assembly of claim 10 wherein the re-entrant portion has
a partially spherical convex surface and the extension has a
partially spherical concave surface that is assembled over the
partially spherical convex surface.
13. The die assembly of claim 10 wherein the first and second
forming surfaces cooperate to back up a compound flange portion of
the panel.
14. The die assembly of claim 10 wherein the first forming surface
is arcuate in shape and is disposed on one edge of the extension,
and further wherein the second forming surface is arcuate in shape
and is disposed on one edge of the rotary cam.
15. The die assembly of claim 10, further comprising a second die
that includes a third forming surface that engages the panel on the
opposite side of the panel from the first and second forming
surfaces when they are adjacent to each other and wherein the
rotary cam rotates the second forming surface to a position that is
not adjacent to the first forming surface to facilitate removal of
the panel from the first die.
Description
BACKGROUND
[0001] 1. Technical Field
[0002] This application relates to a sheet metal forming die having
a rotary cam that is used to form complex shapes.
[0003] 2. Background Art
[0004] Sheet metal panels are formed on die sets that form a sheet
metal blank into a desired shape in a series of steps including
dies for drawing, trimming, flanging, piercing and other operations
in a series of steps. Traditionally, such die sets included an
upper die that is reciprocated relative to a fixed lower die to
perform a desired operation on a sheet metal panel or blank.
Forming cams may be carried by the upper die to form various
surfaces that may not be easily formed with a die that moves in a
vertical reciprocating motion. Rotary cams are used to support or
back up portions of panels that define undercuts or other complex
shapes. Rotary cams are cylindrical in shape and are pivoted
between a forming position and a retracted position. Rotary cams
are pivoted to the retracted, or unload, position to permit the
panel to be removed from a die after forming around an undercut or
complex area.
[0005] To form complex shapes on some panels, it was previously
necessary to provide multiple dies for flanging complex curve
shapes. Using multiple dies for flanging increases dimensional
variation and may adversely affect the appearance of the finished
panel due to variation in part to die locations. Conventional
rotary cams when used in flange dies may not be capable of directly
flanging the part due to the die/part interference when the rotary
cam is retracted to unload the part. This is an inherent limitation
of conventional rotary cam designs and may result in flange bypass
locations on complex parts. Flange bypass locations are areas where
there are gaps between flanging surfaces on a die used to form a
flange. Flange bypass locations may also adversely affect flange
appearance in the finished panel.
[0006] The tooling approach developed by Applicants addresses the
above problems and others that will be apparent to one of ordinary
skill in the art.
SUMMARY
[0007] The die set developed by Applicants includes a rotary cam
that is assembled within a cradle in a lower die. A die insert is
cantilevered over the rotary cam on at least one end of the rotary
cam that has a reduced diameter. The die insert rests on the top of
the reduced diameter portion of the rotor to provide support for
the cantilevered die insert during a flanging operation. The die
insert and reduced diameter end of the rotary cam are machined to a
matching frustoconical or spherical shape that defines a common
radius as viewed normal to the rotor center line. The radius may
vary over the length of the insert. Every section is a true radius
to permit rotation of the rotary cam including the reduced diameter
section about the pivot access of the rotary cam. The rotary cam
has an outer surface that is cylindrical in shape and has a
cylindrical radius. A radius of the bullet nose, or reduced
diameter section, is between zero and the radius of the cylindrical
body portion of the rotor.
[0008] The insert and reduced radius portion of the rotary cam
permits direct flanging over areas of a panel that are back angled
to the direction that the rotor retracts. The increased flexibility
provided by the cantilevered die insert and reduced radius portion
of the rotary cam can be used to reduce the number of flange bypass
locations on a panel. The cantilevered die insert facilitates
providing a variable diameter rotor in a critical location.
[0009] According to one aspect of the disclosure, a die set is
provided for forming a panel in a press. The die set includes an
upper die that is adapted to be set in the press. A lower die is
also adapted to be set in the press to cooperate with the upper
die. A rotary fill cam is assembled to the lower die. The rotary
fill cam is pivoted about an axis and includes a cylindrical
portion and a reduced diameter portion on at least one end. A
cantilevered flange die insert is secured to the lower die to
extend over the reduced diameter portion of the rotary fill cam.
The cantilevered flange die insert fills the space between the
upper die and the reduced diameter portion of the rotary fill
cam.
[0010] According to another aspect of the disclosure, a rotary fill
cam is operatively assembled to a die. The rotary fill cam includes
a body portion that is assembled to the die to pivot within the
die. A bullet nose portion is provided on one end of the body
portion that pivots with the body portion. The die has a
cantilevered flange die insert that overhangs the bullet nose
portion of the rotary fill cam and is supported by the bullet nose
portion in a forming operation.
[0011] According to yet another aspect of the disclosure, a die
assembly is provided that is used to form a panel. The die defines
a cavity in which a rotary cam is received. The rotary cam has a
cylindrical portion and a re-entrant portion. A cantilever
extension is attached to the die and extends into the re-entrant
portion. A first forming surface is provided on the extension and a
second forming surface is provided on the rotary cam that is
rotated to a position adjacent to the first forming surface to form
a portion of the panel.
[0012] According to other aspects of the disclosure, the re-entrant
portion may have a partially spherical convex surface and the
extrusion may have a partially spherical concave surface that are
assembled together. A second die may be provided that includes a
third forming surface that engages the panel on the opposite side
of the panel from the first and second forming surfaces when they
are adjacent to each other. The rotary cam rotates the second
forming surface to a position that is not adjacent to the first
forming surface to facilitate removal of the panel from the first
die.
[0013] These and other features and aspects of the disclosure will
be better understood in view of the attached drawings and the
following detailed description of the illustrated embodiment.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] FIG. 1 is a perspective view of a lower die that includes a
rotary cam disposed in a cavity, or cradle, defined by the lower
die;
[0015] FIG. 2 is a diagrammatic elevation view showing a die insert
cantilevered over a re-entrant portion of a rotary cam with an
upper die and cam former;
[0016] FIG. 3 is a perspective view of a rotary cam having a
re-entrant portion formed on one end;
[0017] FIG. 4 is a fragmentary perspective view of a portion of a
cantilevered insert and rotary cam; and
[0018] FIG. 5 is a fragmentary perspective view of a rotary cam and
cantilevered insert.
DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENT
[0019] Referring to FIG. 1, a lower die 10 is illustrated that
includes a rotary cam 12 that is received in a cavity 14, or
cradle, that is defined by the lower die. The rotary cam 12
includes a cylindrical body portion 18 and a bullet nose portion
20. Conventional rotary cams are generally cylindrical in shape and
do not include any portions that are of reduced radius or diameter
relative to the cylindrical portion 18. A cantilevered extension 22
is assembled to the lower die 10 to extend into and fill the recess
created by the reduced diameter nose portion 20.
[0020] Referring to FIG. 2, a diagrammatic representation of the
rotary cam 10 in the area of the nose portion 20 and cantilevered
extension 22 is illustrated. The rotary cam 12 is rotated about an
axis "A" to the forming position as shown in FIG. 2. The
cylindrical body portion 18 has a radius "R". An insert, or
extended, forming surface 26 is provided on the cantilevered
extension 22. A cam, or extended, forming surface 28 is provided on
the nose portion 20. A panel 30 is formed against the insert
forming surface 26 and the cam forming surface 28 when they are
disposed adjacent to one another.
[0021] The panel 30 may also be formed against an undercut forming
surface 32 that is also provided on the nose portion 20 of the
rotary cam 12. An undercut forming surface 32 may also be provided
on the nose portion 20. The panel 30 may be formed against the
undercut forming surface 32 when the panel 30 is formed.
[0022] An upper die 36 reciprocates relative to the lower die (not
shown in FIG. 2) to fully form a flange against the insert forming
surface 26 and the cam forming surface 28. A cam former 38 may be
used to form the panel 30 in the position shown in phantom lines in
FIG. 2 to the position shown in solid lines against the undercut
forming surface 32. In this position, removal of the panel 30 from
the die would be impossible without the use of the rotary cam 12.
The rotary cam 12 is rotated away from the panel 30 to provide
clearance for removal of the panel 30 from the lower die 10.
[0023] Referring to FIGS. 3 and 4, a rotary cam 12 made according
to one embodiment of the present invention is shown. The rotary cam
12 includes a cylindrical portion 18 and a nose portion 20. The
nose portion 20 includes a convex spherical support surface 40 that
is used to support the cantilevered extension 22 that has a
complimentary concave spherical surface 42. The spherical support
surface 40 supports the cantilevered insert 22 during the forming
operation so that the insert is not damaged when the panel 30 is
formed by the upper die.
[0024] Referring to FIG. 5, the rotary cam 12 is shown in
conjunction with the cantilevered extension 22. The nose portion 20
is of reduced diameter as compared to the cylindrical portion 18.
The reduced diameter nose portion 20 may also be referred to as a
re-entrant portion relative to the cylindrical body portion 18. The
insert 22 defines an insert forming surface 26 that cooperates with
a cam forming surface 28 formed on the nose portion 20. An undercut
forming surface 32 is also shown adjacent the cam forming surface
28 that permits the flange area to be formed beneath the cam
forming surface 28 as previously explained with reference to FIG.
2.
[0025] Although embodiments of the invention have been disclosed,
it will be apparent to persons skilled in the art that
modifications may be made without departing from the scope of the
invention. All such modifications and equivalents thereof are
intended to be defined by the following claims.
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