U.S. patent application number 10/971949 was filed with the patent office on 2005-03-10 for steering column with foamed in-place structure.
This patent application is currently assigned to DELPHI TECHNOLOGIES, INC.. Invention is credited to Riefe, Richard K..
Application Number | 20050052013 10/971949 |
Document ID | / |
Family ID | 29779364 |
Filed Date | 2005-03-10 |
United States Patent
Application |
20050052013 |
Kind Code |
A1 |
Riefe, Richard K. |
March 10, 2005 |
Steering column with foamed in-place structure
Abstract
A composite steering column jacket including a pair of composite
sections joined along a flange area. The composite sections include
outer and inner walls spaced coaxially from each other, that mate
at first and second flanges. A cavity is defined by the space
between the inner and outer walls and is filled with a foam
material that is disposed within. The composite steering column
jacket has an increased stiffness and reduced weight when compared
to conventional metal steering column jackets.
Inventors: |
Riefe, Richard K.; (Saginaw,
MI) |
Correspondence
Address: |
Michael D. Smith
DELPHI TECHNOLOGIES, INC.
Legal Staff, Mail Code: 480-410-202
P.O. Box 5052
Troy
MI
48007-5052
US
|
Assignee: |
DELPHI TECHNOLOGIES, INC.
|
Family ID: |
29779364 |
Appl. No.: |
10/971949 |
Filed: |
October 22, 2004 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10971949 |
Oct 22, 2004 |
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10184464 |
Jun 28, 2002 |
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6814374 |
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Current U.S.
Class: |
280/771 |
Current CPC
Class: |
B32B 2266/0278 20130101;
B32B 2597/00 20130101; B22F 2998/00 20130101; B32B 2605/08
20130101; B22F 2998/00 20130101; B62D 1/16 20130101; B32B 1/08
20130101; B32B 15/046 20130101; B32B 15/08 20130101; B22F 7/006
20130101 |
Class at
Publication: |
280/771 |
International
Class: |
B62D 001/00 |
Claims
1. A composite steering column jacket assembly comprising: a
longitudinally extending outer tubular wall member; a
longitudinally extending inner tubular wall member disposed in said
outer tubular wall member and defining a space between said inner
and outer tubular wall members; said inner and outer tubular wall
members joined immovably to one another by at least one
longitudinally extending side flange, wherein said at least one
longitudinally extending side flange includes first and second
longitudinally extending side flanges; including foam material
disposed in said space, wherein said foam material is polyurethane
foam; and at least one mounting bracket fabricated separately from
said inner and outer tubular wall members and coupled to said first
and second flanges, wherein there are three of said mounting
brackets including an adapter bracket, a shear bracket and a lower
bracket, and including a cable extending between said adapter
bracket and said lower bracket.
Description
TECHNICAL FIELD
[0001] This invention relates to a steering column jacket, and more
particularly, to a steering column jacket having a composite
structure including a foam material.
BACKGROUND OF THE INVENTION
[0002] Generally, beamed structures are used to support a steering
column structure. The beams, often referred to as steering column
jackets, are metal tubes having sufficient strength to support the
forces encountered during a vehicle collision. Current jackets are
generally manufactured from either of two metal-forming processes,
including welding stampings and tubings, as well as utilizing cast
metal parts. The metal jackets are designed with the necessary
strength to support the forces exerted during a vehicle collision,
however, further improvement, including reducing the overall weight
and improving strength characteristics is desirable.
[0003] Also, an improvement of a steering column jacket to dampen
vibrations produced during travel over rough roads would be
desirable. By eliminating a portion of the weight of conventional
steering metal column jackets, an overall weight reduction to a
vehicle may be achieved yielding a higher gas mileage.
[0004] There is therefore a need for a composite steering column
jacket that is lighter in weight when compared with metal steering
column jackets, and has improved dampening characteristics, without
a sacrifice in strength.
BRIEF DESCRIPTION OF THE EMBODIMENT
[0005] A composite steering column jacket including a pair of
composite sections joined along a flange area. The composite
sections are formed of an outer wall having inner and outer
surfaces. The outer wall also includes a first flange formed
thereon. An inner wall having inner and outer surfaces is spaced
coaxially from the outer wall. The inner wall also includes a
second flange that mates with the first flange of the outer wall. A
cavity defined by the space between the inner surface of the outer
wall and the outer surface of the inner wall has foam material
disposed within. The composite steering column jacket has an
increased stiffness and reduced weight in comparison to a
conventional metal steering column jacket.
[0006] In an alternative embodiment, an aluminum foam is attached
to the outer surfaces of the inner and outer walls to strengthen
the overall structure of the composite steering column jacket, in
lieu of the foam contained within the cavity
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] These features and advantages of the present invention will
become more readily appreciated when considered in connection with
the following detailed description and appended drawings,
where:
[0008] FIG. 1 is a perspective view of a first embodiment of the
composite steering column jacket of the present invention;
[0009] FIG. 2 is an assembled perspective view showing the first
embodiment of the present invention including the mounting
brackets;
[0010] FIG. 3A-C details various cross-sectional views of
alternative shapes of the composite steering column jacket of the
present invention;
[0011] FIG. 4 is a cross-sectional view of the composite steering
column jacket detailing the aluminum foam attached to the outer
surfaces of the inner and outer walls.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0012] Referring to FIG. 1, there is shown the composite steering
column jacket 5 of the present invention. The composite steering
column jacket 5 comprises a pair of composite sections 10 joined
along a flange area 15. Each of the composite sections 10 includes
an outer wall 20 having inner 25 and outer 30 surfaces. The outer
wall 20 includes a first flange 35 formed thereon. An inner wall 40
having inner 45 and outer 50 surfaces is coaxially spaced from the
outer wall 20. The inner wall 40 also includes a second flange 55
formed thereon that mates with the first flange 35 of the outer
wall 20. A cavity 60 is defined by the space between the inner
surface 25 of the outer wall 20 and the outer surface 50 of the
inner wall 40. A foam material 65 is disposed within the cavity
60.
[0013] As can be seen in FIG. 1, the pair of composite sections 10
forms an annular structure 70 having an outer dimensional shape 75
and an inner dimensional shape 80. As shown in FIG. 1 in a
preferred embodiment, the outer wall 20 and inner wall 40 are
formed such that when mated as a pair, the shape is rectangular. As
shown in the pictured preferred embodiment, the outer wall 20 is
bent such that it forms a U-shaped section having flanges 35 on its
outer edges, and the inner wall 40 is bent such that it has a
V-shape, again with flanges 55 formed on its edges. The metal sheet
of the outer 20 and inner 40 walls may be bent on a metal brake or
other metal forming apparatus to form the shapes of the outer 20
and inner wall 40. While in the pictured preferred embodiment, the
pair of composite sections 10 forms an annular structure 70 that is
rectangular in its outer dimension 75 as well as its inner
dimension 80, other shapes and structures are contemplated for use
by the present invention. For example, as shown in FIG. 3A-C, other
cross-sectional shapes (shown without a flange) such as square,
circular, ovoid, pentagonal, hexagonal, or other shapes may be
utilized to form the outer dimensional shape 75 and inner
dimensional shape 80 of the annular structure 70. The only
limitation as to the various shapes and structures is that the
composite steering column jacket 5 have the requisite strength and
characteristics for use in an automotive application.
[0014] In the picture preferred embodiment of FIG. 1, the cavity 60
defined by the space between the inner surface 25 of the outer wall
20 and the outer surface 50 of the inner wall 40 is filled with a
foam material that preferably comprises a polyurethane foam. The
polyurethane foam acts as a damping agent to absorb vibrations
produced while driving. The polyurethane foam also provides a
rigidity when cured to the composite steering column jacket 5 by
filling the cavity 60 between the outer 20 and inner 40 walls. The
overall weight of the composite structure is less than that of a
conventional metal steering column jacket and provides increased
dampening and strength characteristics.
[0015] When forming the composite sections 10 of the present
invention, the outer wall 20 and inner wall 40 are shaped on metal
forming rolling dies to an appropriate shape as determined by the
application. The four flanges comprising the first 35 and second 55
flanges of the pair of composite sections 10 are seam welded, while
polyurethane foam is injected in place. A continuous manufacturing
process may be utilized to shape the walls from coils of sheet
metal and wherein foam is injected to expand and harden while the
halves of the parts are brought together for fastening at the
flanges. The proper lengths of steering column jackets may then be
cut from the continuously manufactured steering column jacket 5 for
use in a variety of vehicles. The flange area 15 comprises the
portion of the first 35 and second 55 flanges that are joined to
form a seam. The flange area 15 of the first of the pair of
composite sections is joined with the flange area 15 of the second
of the pair of composite sections 10 to form the composite steering
column jacket 5. The actual order in which the flanges 35, 55 are
joined may vary depending on the desired processing used by the
manufacturer. For example, the first 35 and second 55 flanges may
be seam welded to provide a seal and then a second of the pair of
composite sections 10 may have the first 35 and second flanges 55
seam welded wherein the flange area 15 formed in the first of the
pair is then seam welded with the flange area 15 of the second of
the pair of composite sections 10 to form the composite steering
column jacket 5. However, all four flanges 35, 55 may be joined in
a single operation, such as that referred to above wherein the
flanges 35, 55 are joined and polyurethane foam is injected into
the cavity 65. The order in which the flanges 35, 55 are sealed is
not limiting on the inventive aspect of the composite steering
column jacket 5 of the present invention.
[0016] In a first embodiment of the composite steering column
jacket 5, as shown in FIG. 2, there is preferably included at least
one mounting bracket 85 attached to the outer surface 30 of the
outer wall 20. In a preferred embodiment, three mounting brackets
including an adapter bracket 90, shear bracket 95, and a lower
bracket 100 are attached to the outer surface 30 of the outer wall
20. The adapter bracket 90 is preferably positioned at a top end
150 of the steering column jacket 5 and is designed to receive the
upper steering column on which a hand wheel is positioned. The
shear bracket 95 and lower bracket 100 are positioned along a
mid-portion 155 and lower end 160 respectively of the steering
column jacket 5. The shear bracket 95 includes notches 170 formed
therein wherein plastic pins are injected to provide a breakaway
feature commonly utilized in collapsible steering columns. The
shear bracket 95 and lower bracket 100 include channel portions 105
for receiving the flange area 15 of the pair of composite sections
10. The channel 105 allows the brackets 95, 100 to be slid in place
for ease of manufacture without having to remove portions of the
flange area 15 to allow mounting of the brackets 95, 100. All of
the mounting brackets 85 including the adapter bracket 90, shear
bracket 95, and lower bracket 100 are attached to the outer surface
30 of the outer wall 20. The brackets 85 may be bonded with
adhesive, or other fastening means to provide a reliable bond.
[0017] Again with reference to FIG. 2, in a first embodiment the
composite steering column jacket 5 includes a pre-stress cable 110
attached to the adapter bracket 90 and the lower bracket 100. The
pre-stress cable 110 is maintained under tension to provide a
compression force to the composite steering column jacket 5 for
negating a shear force that may be placed on the composite steering
column jacket 5 during a crash. The pre-stress cable 110 is
manufactured such that it is attached to the adapter bracket 90 and
lower bracket 100 under a stressed condition. Specifically, a
tension can be applied to the pre-stress cable 110 to place a
compression load on the composite steering column jacket 5 as
desired by a manufacturer.
[0018] With reference to FIG. 4, there is shown a second embodiment
of the composite steering column jacket 5 of the present invention.
The second embodiment is identical to that of the first embodiment
with the exception that rather than disposing a foam material 65
within a cavity 60 as disclosed in the first embodiment, a foam
material 115 is disposed on the outer surfaces 30, 50 of the outer
20 and inner 40 walls, respectively. Preferably the foam material
115 comprises an aluminum foam that provides a stiffness and
strength to the outer 20 and inner 40 walls of the composite
sections 10. A particularly preferred aluminum foam includes that
manufactured by ERG materials and Aerospace Corporation under the
trademarked name Duocel.RTM.. When manufacturing a composite
steering column jacket 5 according to the second embodiment, the
aluminum foam 115 may be applied to the outer surfaces 30, 50 of
the outer 20 and inner 40 walls with the exception of the flange
areas 35, 55 prior to sealing the flanges 35, 55 as described in
the manufacturing process disclosed in the first embodiment.
Alternatively, the flanges 35, 55 may be seam welded while the foam
115 is being applied to the outer surfaces 30, 50 in a continuous
manufacturing process.
[0019] While preferred embodiments are disclosed, a worker in this
art would understand that various modifications would come within
the scope of the invention. Thus, the following claims should be
studied to determine the scope and content of the invention.
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