U.S. patent application number 11/276626 was filed with the patent office on 2007-09-13 for hydroformed seatback frame.
This patent application is currently assigned to LEAR CORPORATION. Invention is credited to Vincent Adragna, Eric Beaulieu, Gary Greiner.
Application Number | 20070210638 11/276626 |
Document ID | / |
Family ID | 37988566 |
Filed Date | 2007-09-13 |
United States Patent
Application |
20070210638 |
Kind Code |
A1 |
Adragna; Vincent ; et
al. |
September 13, 2007 |
HYDROFORMED SEATBACK FRAME
Abstract
An automotive seat assembly comprising a hydroformed hollow
metal tube having a cross-section which varies in shape along its
length, the hydroformed hollow metal tube having a first vertical
support section having a top end and a bottom end, a second
vertical support section having a top end and a bottom end, and a
transverse section extending between the respective top ends of the
first and second support sections.
Inventors: |
Adragna; Vincent; (New
Hudson, MI) ; Beaulieu; Eric; (Farmington Hills,
MI) ; Greiner; Gary; (Chesterfield, MI) |
Correspondence
Address: |
BROOKS KUSHMAN P.C. / LEAR CORPORATION
1000 TOWN CENTER
TWENTY-SECOND FLOOR
SOUTHFIELD
MI
48075-1238
US
|
Assignee: |
LEAR CORPORATION
21557 Telegraph Road
Southfield
MI
|
Family ID: |
37988566 |
Appl. No.: |
11/276626 |
Filed: |
March 8, 2006 |
Current U.S.
Class: |
297/452.2 |
Current CPC
Class: |
B60N 2/68 20130101 |
Class at
Publication: |
297/452.2 |
International
Class: |
A47C 7/02 20060101
A47C007/02 |
Claims
1. An automotive seat frame assembly comprising: an automotive
seatbottom frame; and an automotive seatback frame connected to the
seatbottom frame, the seatback frame comprising a hydroformed
hollow metal tube having a cross-section which varies in shape
along its length, the hydroformed hollow metal tube having a first
vertical support section having a top end and a bottom end, a
second vertical support section having a top end and a bottom end,
and a transverse section extending between the respective top ends
of the first and second support sections.
2. The automotive seat frame assembly of claim 1 wherein the
hydroformed hollow metal tube comprises a wall having substantially
uniform thickness along its entire length.
3. The automotive seat frame assembly of claim 2 wherein the
cross-sectional shape of the hydroformed hollow metal tube is
formed using a low pressure hydroforming process.
4. The automotive seat frame assembly of claim 1 wherein the bottom
ends of the vertical support sections have a cross-sectional shape
that facilitates connection of the seatback frame to the seatbottom
frame.
5. The automotive seat frame assembly of claim 4 wherein the
cross-sections of the respective bottom ends of the first and
second vertical support sections have a shape that corresponds with
the shape of the seatbottom frame at the location where the
seatback frame is connected to the seatbottom frame.
6. The automotive seat frame assembly of claim 5 wherein the
cross-sections of the respective bottom ends of the first and
second vertical support sections are shaped to be received by, or
be received within, the seatbottom frame connecting the seatback
frame to the seatbottom frame.
7. The automotive seat frame assembly of claim 1 wherein a portion
of at least one of the vertical support sections has a generally
triangular cross-section.
8. The automotive seat frame assembly of claim 7 wherein the
triangular cross-section is at a location of the at least one
vertical support section where the at least one of the vertical
support sections will bear the highest load during a rear
impact.
9. The automotive seat frame assembly of claim 1 wherein the
transverse section has a front side and wherein at least a portion
of the front side is depressed to form a recess large enough to
receive a person's neck.
10. The automotive seat frame assembly of claim 1 wherein the
transverse section is adapted to receive a headrest.
11. The automotive seat frame assembly of claim 10 wherein the
transverse section has a top side and a bottom side, wherein the
top side has a pair of holes and the bottom side has a pair of
holes, and wherein the pair of holes in the top side are axially
aligned with the pair holes in the bottom side to enable the
transverse section to receive posts from a headrest.
12. The automotive seat frame assembly of claim 10 wherein the
holes are extruded.
13. The automotive seat frame assembly of claim 1 wherein the
respective bottom ends of the first and second support sections
have a cross-sectional shape that allows the seatback frame to be
connected to the seatbottom frame, wherein a portion of at least
one of the vertical support sections has a generally triangular
cross-section, wherein the transverse section has a front side
having a recess large enough to receive a person's neck, and
wherein the transverse section is adapted to receive a
headrest.
14. An automotive seatback frame for use with an automotive seat
having a seatbottom having a seatbottom frame, and a seatback
having a seatback frame, the automotive seatback frame comprising:
a hydroformed hollow metal tube having a cross-section which varies
in shape along its length, the tube having a first vertical support
section having a top end and a bottom end, a second vertical
support section having a top end and a bottom end, and a transverse
section extending between the top ends of the first and second
support sections.
15. The automotive seatback frame of claim 14 wherein the
automotive seatback frame is made from SAE 050XF steel and wherein
the automotive seatback frame has a rear load strength to weight
ratio of at least approximately 3.0 KN/Kg.
16. A method of making an automotive seat frame comprising the
steps of: providing an automotive seatbottom frame; providing the
automotive seatback frame of claim 14; and connecting the
automotive seatbottom frame to the seatback frame.
17. An automotive seat assembly comprising: an automotive
seatbottom comprising an automotive seatbottom frame, an automotive
seatbottom cushion supported on the automotive seatbottom frame and
an automotive seatbottom cover covering the automotive seatbottom
frame and automotive seatbottom cushion; an automotive seatback
comprising an automotive seatback frame, an automotive seatback
cushion supported on the automotive seatback frame and an
automotive seatback cover covering the automotive seatback frame
and the automotive seatback cushion, the automotive seatback frame
being connected to the automotive seatbottom frame; the automotive
seatback frame comprising a hydroformed hollow metal tube having a
cross-section which varies in shape along its length, the
hydroformed hollow metal tube having a first vertical support
section having a top end and a bottom end, a second vertical
support section having a top end and a bottom end, and a transverse
section extending between the respective top ends of the first and
second support sections.
18. The automotive seat assembly of claim 17 wherein the
hydroformed hollow metal tube comprises a wall having substantially
uniform thickness along its entire length.
19. The automotive seat assembly of claim 17 wherein the bottom
ends of the vertical support sections have a cross-sectional shape
that facilitates the connection of the seatback frame to the
seatbottom frame.
20. The automotive seat assembly of claim 17 wherein a portion of
at least one of the vertical support sections has a generally
triangular cross-section, wherein the transverse section has a
front side wherein at least a portion of the front side is
depressed to form a recess large enough to receive a person's neck
and wherein the transverse section is adapted to receive a
headrest.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The invention relates to a hydroformed seatback frame.
[0003] 2. Background Art
[0004] A hydroformed seatback frame is disclosed herein. Examples
of electrical hydroformed seat components are disclosed in U.S.
Pat. Nos. 6,352,311; 6,957,796; 5,564,785; 5,437,498; 5,452,941;
5,845,382; and 5,988,756 as well as published Application No.
2004/0135411.
SUMMARY OF THE INVENTION
[0005] In accordance with at least one aspect of the present
invention, an automotive seat frame assembly is provided. In at
least one embodiment, the automotive seat frame assembly comprises
an automotive seatbottom frame connected to an automotive seatback
frame. The automotive seatback frame includes a hydroformed hollow
metal tube having a cross-section which varies in shape along its
length. In this embodiment, the hydroformed hollow metal tube has a
first vertical support section having a top end and a bottom end, a
second vertical support section having a top end and a bottom end,
and a traverse section extending between the respective top ends of
the first and second support sections.
[0006] In accordance with at least another aspect of the present
invention, an automotive seatback frame is provided for use with an
automotive seat having a seatbottom and seatbottom frame, a
seatback and seatback frame. The automotive seatback frame includes
a hydroformed hollow metal tube having a cross-section which varies
in shape along its length. In this embodiment, the hydroformed
hollow metal tube has a first vertical support section having a top
end and a bottom end, a second vertical support section having a
top end and a bottom end, and a traverse section extending between
the respective top ends of the first and second support
sections.
[0007] In accordance with yet another aspect of the present
invention, an automotive seat assembly is provided. The automotive
seat assembly includes an automotive seatbottom and an automotive
seat back. The automotive seatbottom includes an automotive
seatbottom frame, an automotive seatbottom cushion supported on the
automotive seatbottom frame and an automotive seatbottom cover
covering the automotive seatbottom frame and automotive seatbottom
cushion. The automotive seatback includes an automotive seatback
frame, an automotive seatback cushion supported on the automotive
seatback frame and an automotive seatback cover covering the
automotive seatback frame and the automotive seatback cushion. The
automotive seatback frame is connected to the automotive seatbottom
frame. Furthermore, the automotive seatback frame includes a
hydroformed hollow metal tube having a cross-section which varies
in shape along its length. In this embodiment, the hydroformed
hollow metal tube has a first vertical support section having a top
end and a bottom end, a second vertical support section having a
top end and a bottom end, and a traverse section extending between
the respective top ends of the first and second support
sections.
[0008] While exemplary embodiments in accordance with the invention
are illustrated and disclosed, such disclosures should not be
construed to limit the claims. It is anticipated that various
modifications and alternative designs may be made without departing
from the scope of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1 is a cut away perspective view of an automotive seat
assembly showing an automotive seat frame assembly made in
accordance with at least one embodiment of the present
invention;
[0010] FIG. 2 is a perspective view of a component of the
automotive seat frame assembly illustrated in FIG. 1;
[0011] FIG. 3 is a cross-sectional view of the component
illustrated in FIG. 2 taken along the line 3-3 of FIG. 2;
[0012] FIG. 4a is a perspective view of the component illustrated
in FIG. 2 prior to its connection with another component of the
automotive seat frame assembly illustrated in FIG. 1;
[0013] FIG. 4b is a perspective view of the component illustrated
in FIG. 2 connected to the component of the automotive seat frame
assembly illustrated in FIG. 4a;
[0014] FIG. 5 is a cross-sectional view of the component
illustrated in FIG. 2 taken along the line 5-5 of FIG. 2;
[0015] FIG. 6 is a cross-sectional view of the component
illustrated in FIG. 2 taken along the line 6-6 of FIG. 2; and
[0016] FIG. 7 is a cross-sectional view of the component
illustrated in FIG. 2 taken along the line 7-7 of FIG. 2.
DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENT(S)
[0017] The following descriptions are merely exemplary in nature
and are in no way intended to limit the invention, its application,
or its uses.
[0018] Reference will now be made in detail to presently preferred
compositions, embodiments and methods of the present invention,
which constitute the best modes of practicing the invention
presently known to the inventors. The Figures are not necessarily
to scale. However, it is to be understood that the disclosed
embodiments are merely exemplary of the invention that may be
embodied in various and alternative forms. Therefore, specific
details disclosed herein are not to be interpreted as limiting, but
merely as a representative basis for any aspect of the invention
and/or as a representative basis for teaching one skilled in the
art to variously employ the present invention.
[0019] Referring to FIG. 1, a cut-away perspective view of an
exemplary automotive seat assembly 1 is illustrated. The automotive
seat assembly 1 illustrated in FIG. 1 includes an automotive frame
assembly 5, a seatbottom cushion 2, a seatbottom cover 3, a
seatback cushion 4, and a seatback cover 6. The automotive seat
frame assembly 5 includes an automotive seatbottom frame 10. The
automotive seatbottom frame 10 is mountable, as shown in FIG. 1, on
a set of tracks 11 usable to mount the automotive seat frame
assembly 5 to an automobile (not shown). The automotive seat frame
assembly 5 further includes a hydroformed automotive seatback frame
15 connected to the automotive seatbottom frame 10.
[0020] The hydroformed automotive seatback frame 15 shown in FIG.
2, is made using a suitable hydroforming process. Hydroforming is a
relatively well known manufacturing process and generally includes
placing a hollow metal blank in a mold cavity, closing the mold
which, in turn, causes the hollow metal blank to partially conform
to the shape of the mold cavity. The hollow portion of the blank is
then filled with fluid at a high enough pressure to cause the walls
of the metal blank to expand until they are flush with the surface
of the mold cavity. The fluid is then drained from the blank, the
mold is opened, and the hollow metal blank, now a hydroformed metal
part, is removed.
[0021] The hydroformed automotive seatback frame 15 has a
cross-section that varies along its length. This varying cross
section can facilitate attachment of items to the hydroformed
automotive seatback frame 15 as well as attachment of the
hydroformed automotive seatback frame 15 to the automotive seat
bottom frame 10. The cross sectional variations can also provide
structural reinforcement at desired locations along the automotive
seatback frame. Moreover, the seatback frame 15 is relatively
resistant to bending and twisting compared with conventional
seatback frames that either have varying cross sections but which
are not hollow, or which are hollow but do not have varying cross
sections.
[0022] While the seatback frame 15 may be made of any suitable
metal, in at least one embodiment, the hydroformed seatback frame
15 is made of SAE 050XF steel. In at least one embodiment, the
seatback frame 15 has a rear load strength to weight ratio of at
least 3.0 KN/Kg, in at least another embodiment of at least 3.16
KN/Kg, and in at least yet another embodiment of at least 3.25
KN/Kg. In at least one embodiment, the seatback frame has a rear
load strength to weight ratio of approximately 15% greater than the
rear load strength to weight ratio of a standard stamped steel
construction rear seat back made of the same material, in another
embodiment of approximately 20% greater, and in yet another
embodiment approximately 25% greater.
[0023] In at least one embodiment, the hydroforming mold can be
configured to punch and/or extrude holes in the hydroformed
automotive seatback frame 15 during molding. This can permit the
relatively easy insertion of appendages, such as a headrest into
the hydroformed automotive seatback frame 15 and/or the fastening
of the hydroformed automotive seatback frame 15 to the automotive
seat bottom frame 10. This can be done using a mold designed with
punches in desirable locations. During the hydroforming process,
after the hollow metal blank has been formed, and before the
pressure of the fluid is reduced, the punch, in cooperation with
the fluid, is able to punch or extrude holes as desired in the
surface of the hollow metal tube. This can save time and reduces
cost by permitting a one-step manufacturing process.
[0024] The hydroformed automotive seatback frame 15 illustrated in
FIG. 2 has a first vertical support section 16, a second vertical
support section 17 and a transverse section 18. The first vertical
support section 16 has a bottom end 20 and a top end 19. The second
vertical support section 17 has a bottom end 22 and a top end 23.
The transverse section 18 extends between and connects the top end
of the first vertical support section 19 and the top end of the
second vertical support section 23.
[0025] As illustrated in FIG. 2, this embodiment of the hydroformed
automotive seatback frame 15 has four areas of distinct
cross-sectional geometry. It should be understood that a greater or
lesser number of distinct cross-sectional geometries may be used,
depending on design requirements.
[0026] A first distinct cross-sectional geometry of the embodiment
illustrated in FIG. 2 is at the bottom ends of the first and second
vertical support sections 20, 22. In this embodiment, bottom ends
20, 22 have been shaped to facilitate the attachment of the
hydroformed automotive seatback frame 15 to the automotive
seatbottom frame 10. An example of a bottom end cross-section is
shown in FIG. 3, where the cross section of bottom end 22 has at
least partially been formed into a relatively thin channel capable
of receiving posts or other protrusions 40 (see FIG. 4a) from the
seatbottom frame 10. The cross-section depicted in FIG. 3 was taken
along the line 3-3 from FIG. 2.
[0027] Attachment of the exemplary hydroformed automotive seatback
frame 15, illustrated in FIG. 2, to the automotive seatbottom frame
10 is depicted in FIGS. 4a and 4b. As illustrated in FIG. 4a,
attachment protrusions 40 are received within the respective bottom
ends of the first and second vertical support sections 20, 22. FIG.
4b illustrates the exemplary hydroformed automotive seatback frame
15 fully seated on the attachment protrusions 40. In the embodiment
depicted in FIG. 4b, holes have been punched through the walls of
the bottom ends 20 and 22 to facilitate fastening the hydroformed
automotive seatback frame to the automotive seatbottom. The
geometry of the attachment protrusions 40 could easily be altered
to allow the attachment protrusions 40 to receive the bottom ends
of the vertical support sections 20, 22.
[0028] A second distinct cross-sectional geometry of the exemplary
hydroformed automotive seatback frame 15 illustrated in FIG. 2 is
located approximately halfway up the first and second vertical
support sections. FIG. 5 depicts a cross-sectional view of the
exemplary automotive hydroformed seatback frame 15 taken along the
lines 5-5, depicted in FIG. 2. As shown in FIG. 5, the
cross-sectional geometry is generally triangular. In this
embodiment, the triangular cross-section is located where the first
and second vertical support sections 16,17 will experience the
highest load during a rear impact. A triangular cross-sectional
geometry provides good resistance to impact force, such as those
the seatback frame is likely to experience in the event of a
rear-end collision.
[0029] A third distinct cross-sectional geometry of the embodiment
shown in FIG. 2 is located along the transverse section 18. FIG. 6
shows a cross-sectional view taken horizontally along the line 6-6
(shown in FIG. 2) through the transverse section 18. As
illustrated, transverse section 18 has a front side 41 and a back
side 42. A depression 30 has been formed in the front side 41. This
depression will provide added support for the neck of an occupant
of the automotive seat assembly 1 during a rear-end collision. The
depression may also provide additional comfort to the occupant
during normal vehicle operations.
[0030] A fourth distinct cross-sectional geometry of the embodiment
shown in FIG. 2, also located along the transverse section 18, is
illustrated in FIG. 7. FIG. 7 illustrates a cross-sectional view of
the exemplary hydroformed automotive seatback frame 15 taken
vertically along the line 7-7 (shown in FIG. 2) through the
transverse section 18. This cross section is generally rectangular.
This shape provides excellent resistance to rotation which makes it
well suited to support a headrest.
[0031] In the embodiment of the hydroformed automotive seatback
frame 15 depicted in FIG. 2, holes have been extruded in the
transverse section 18. This is illustrated in FIG. 7 which
illustrates a vertical cross-sectional cut through the transverse
section 18 along the lines 7-7 (shown in FIG. 2). Line 7-7 of FIG.
2 intersects the transverse section 18 through one of two
adaptations to receive a headrest 35. Transverse section 18 has a
top side 37 and a bottom side 38. The adaptation to receive a
headrest 35 consists of a hole extruded into the top side 37 of the
transverse section 18 that is coaxial with a second hole extruded
into the bottom side 38 of the transverse section 18. The extruded
portion of the holes is indicated by the reference numeral 45 in
FIG. 7.
[0032] It is desirable that the thickness of its walls remain
relatively constant. Traditional high pressure hydroforming methods
can result in attenuated wall thicknesses at curved areas of the
hydroformed product. One way to ensure consistent wall thickness is
to use a pressure sequence hydroforming process. According to this
process, the hollow metal blank is placed in the mold cavity and
the mold is partially closed causing some deformation of the blank.
The hollow portion of the blank is then filled with fluid that is
maintained within the hollow portion of the blank at a low
pressure. The cavity is then closed completely. As the die closes
completely, the walls of the blank are supported internally by the
fluid. Once the die is completely closed, the internal fluid
pressure is increased to finish forming the product and also to
provide backup for punching holes. This method of low pressure
hydroforming is fully disclosed in U.S. Pat. No. 6,397,449 to Mason
et al., the disclosure of which is herein incorporated by
reference. Use of the pressure sequence hydroforming process
minimizes attenuation of wall thickness around curves and
corners.
[0033] The embodiment of the hydroformed automotive seatback frame
15 shown in FIG. 2 was made using a pressure sequence hydroforming
process. Accordingly, the wall thickness of flat and curved
portions are substantially the same. This is depicted in FIGS. 3,
5, 6, and 7. The wall thickness 21 of bottom end 20 is consistent
throughout the entire cross-section, as shown in FIG. 3. The same
is true of wall 26 of the triangular cross-section of the second
vertical support section 17 (as shown in FIG. 5), the wall
thickness 31 of the transverse section 18 (as shown in FIG. 6), and
wall thickness 36 of the transverse section 18 (as shown in FIG.
7).
[0034] In another aspect of the invention, a method of making an
automotive seat frame is disclosed. According to this aspect of the
invention, an automotive seatbottom frame 10 is provided, a
hydroformed automotive seatback frame 15 including a hydroformed
hollow metal tube having a cross-section which varies in shape
along its length, the tube having a first vertical support section
having a top end and a bottom end, a second vertical support
section having a top end and a bottom end, and a transverse section
extending between the top ends of the first and second support
sections is provided, and the automotive seatbottom frame is
connected to the automotive seatback frame.
[0035] While embodiments of the invention have been illustrated and
described, it is not intended that these embodiments illustrate and
describe all possible forms of the invention. Rather, the words
used in the specification are words of description rather than
limitation, and it is understood that various changes may be made
without departing from the spirit and scope of the invention.
* * * * *