U.S. patent application number 09/832027 was filed with the patent office on 2002-10-17 for fiber reinforced suspension member.
Invention is credited to Bradley, Douglas James, Lawson, Robert Christian.
Application Number | 20020149190 09/832027 |
Document ID | / |
Family ID | 25260461 |
Filed Date | 2002-10-17 |
United States Patent
Application |
20020149190 |
Kind Code |
A1 |
Bradley, Douglas James ; et
al. |
October 17, 2002 |
FIBER REINFORCED SUSPENSION MEMBER
Abstract
The present invention provides for a fiber reinforced suspension
member having an integral pivot opening. The suspension member
includes a first portion, a second portion and a central portion
disposed in between the first portion and the second portion. The
suspension member in accordance with the teachings of the present
invention is formed of fibers that extend longitudinally from the
first portion to the central portion and curve around the central
portion such that an opening is defined in the central portion. The
fibers forming the suspension member typically comprise an upper
fiber layer and a lower fiber layer. The upper fiber layer and the
lower fiber layer interface in the first portion and the second
portion and are separated in the central portion. The upper layer
fiber and the lower layer fiber are reinforced around the opening
by stitching reinforcing fibers through the thickness of the
suspension member.
Inventors: |
Bradley, Douglas James;
(Howell, MI) ; Lawson, Robert Christian; (Ann
Arbor, MI) |
Correspondence
Address: |
BRINKS HOFER GILSON & LIONE
P.O. BOX 10395
CHICAGO
IL
60610
US
|
Family ID: |
25260461 |
Appl. No.: |
09/832027 |
Filed: |
April 10, 2001 |
Current U.S.
Class: |
280/786 ;
267/36.1; 280/124.17 |
Current CPC
Class: |
B60G 2206/10 20130101;
B60G 2206/428 20130101; F16F 1/366 20130101; B60G 7/001 20130101;
B60G 2206/7101 20130101 |
Class at
Publication: |
280/786 ;
280/124.17; 267/36.1 |
International
Class: |
B62D 021/04; B60G
011/02 |
Claims
What is claimed is:
1. A fiber reinforced suspension member to be used in a motor
vehicle comprising: an upper layer of fiber; a lower layer of
fiber; a first reinforcing fiber extending through the upper layer
of fiber to the lower layer of fiber and adapted to connect the
upper layer of fiber and the lower layer of fiber at a first
location; and a second reinforcing fiber extending through the
upper layer of fiber to the lower layer of fiber and adapted to
connect the upper layer of fiber and the lower layer of fiber in a
second location, wherein the first reinforcing fiber and the second
reinforcing fiber define an opening between the first location and
the second location.
2. The fiber reinforced suspension member of claim 1 wherein the
opening defines a circular cross-section.
3. The fiber reinforced suspension member of claim 1 wherein the
opening defines a diamond shaped cross-section.
4. The fiber reinforced suspension member of claim 1 wherein the
upper layer of fiber and the lower layer of fiber are selected from
a group consisting of synthetic fibers, metal fibers, vegetable
fibers and animal fibers.
5. The fiber reinforced suspension member of claim 1 wherein the
upper layer of fiber and the lower layer of fiber are pre-treated
with a resin wherein the resin is selected from a group consisting
of polyester, vinyl ester, epoxy, phenolic, and cyanate ester.
6. The fiber reinforced suspension member of claim 1 further
comprising a bushing placed within the opening between the first
location and the second location in fiber reinforced suspension
member.
7. The fiber reinforced suspension member of claim 6 wherein the
bushing is an integral part of the fiber reinforced suspension
member.
8. A fiber reinforced suspension member of claim 1 wherein the
first reinforcing fiber and the second reinforcing fiber are in
form of stitches such that the upper layer of fibers and the lower
layer of fiber are held together by the stitches at the first
location and the second location.
9. A fiber reinforced suspension member of claim 1 wherein the
first reinforcing fiber and the second reinforcing fiber are
substantially perpendicular to the longitudinal axis of the fiber
reinforced suspension member.
10. The fiber reinforced suspension member of claim 1 wherein the
first reinforcing fiber and the second reinforcing fiber are
selected from a group consisting of fiber-glass, aramid fiber and
carbon fibers.
11. A method of forming fiber reinforced suspension member
comprising the steps of: providing an first layer of fiber;
providing an second layer of fiber; stitching a first reinforcing
fiber through the first layer of fiber to the second layer of fiber
at a first location such that first layer of fiber and second layer
of fiber are connected at the first location; stitching a second
reinforcing fiber through the first layer of fiber to the second
layer of fiber at a second location such that first layer of fiber
and second layer of fiber are connected at the second location; and
defining an opening with the first reinforcing fiber and the second
reinforcing fiber between the first location and the second
location.
12. The method of claim 11 further comprising selecting the first
layer of fiber and the second layer of fiber are selected from a
group consisting of synthetic fibers, metal fibers, vegetable
fibers and animal fibers.
13. The method of claim 11 further comprising pre-treating the
first layer of fiber and the second layer of fiber with a resin
selected from a group consisting of polyester, vinyl ester, epoxy,
phenolic, and cyanate ester.
14. The method of claim 11 further comprising selecting the first
reinforcing fiber and second reinforcing fibers are selected from a
group consisting of fiber-glass, aramid fiber, and carbon
fibers.
15. The method of claim 11 further comprising placing a bushing
within the opening between the first location and the second
location.
Description
TECHNICAL FIELD OF THE INVENTION
[0001] This patent discloses and claims a useful, novel, and
unobvious invention for a fiber reinforced suspension system for
use in motor vehicles. More specifically a fiber reinforced
suspension member with an integral pivot opening is disclosed in
the present application.
BACKGROUND OF THE INVENTION
[0002] Suspension members in motor vehicles are typically
fabricated from steel layers. This method of fabricating suspension
members is not only cumbersome but also increases the overall
weight of the motor vehicle. Recently, in order to manufacture
lighter vehicles composite materials such as fiberglass or carbon
fibers have been used to make suspension members. Although these
composite materials have good physical properties they tend to be
more expensive than a traditional metal part. Much of the cost of
the suspension member parts is attributed to the fact that pivots
or mounting holes usually take the form of separate metal pieces
that have to be bolted, riveted or bonded to the composite
material. Therefore, there is a need in the automotive industry to
make suspension members that are light and cheaper.
BRIEF DESCRIPTION OF THE FIGURES
[0003] FIG. 1 is a perspective view of the fiber reinforced
suspension member, the opening having a circular cross-section and
having the reinforcement fibers displaced along the transverse axis
in accordance with the preferred embodiment of the present
invention;
[0004] FIG. 2 is a cross-sectional view along line 2-2 in FIG. 1 in
accordance with the preferred embodiment of the present
invention;
[0005] FIG. 3 is a front view of the fiber reinforced suspension
member having an integral bushing and the reinforcement fibers
displaced along the longitudinal axis in accordance with the
preferred embodiment of the present invention; and
[0006] FIG. 4 is a perspective view of the fiber reinforced
suspension member the opening having a diamond shaped cross-section
and having the reinforcement fibers displaced along the transverse
axis in accordance with the second embodiment of the present
invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0007] The following description of the preferred embodiment is
merely exemplary in nature, and is in no way intended to limit the
invention or its application or uses.
[0008] Referring in particular to the drawings, a composite
suspension member having an integral pivot point in accordance with
the teachings of the present invention is generally designated by
reference numeral 10. Although not shown in the drawings, a
suspension member 10 is preferably used to connect the vehicular
frame to components of a vehicle that are in contact with the
ground such as wheels.
[0009] As shown in FIG. 1, the suspension member 10 in accordance
with the teachings of the present invention comprises a first
portion 14, a central portion 16 and a second portion 18.
Preferably, the central portion 16 is disposed in between the first
portion 14 and the second portion 18. Alternatively it is possible
that the central portion 16 is disposed at one end of the first
portion 14 or the second portion 18. The suspension member 10
defines a longitudinal axis 25 and a transverse axis 27.
[0010] As shown in FIG. 1, the central portion 16 has a
substantially circular cross section and functions to receive a
connector or a pivot member that connects the suspension member 10
to other components of a motor vehicle. Preferably, the central
portion 16 is symmetrical about the longitudinal axis 25 and the
transverse axis 27. Alternatively, it is possible that the central
portion 16 has an oblong configuration or a diamond shape
cross-section (as shown in FIG. 4). Further, the central portion 16
may take any alternate shape capable of defining an opening. The
first portion 14 and the second portion 18 preferably extend
longitudinally away from the central portion 16. Preferably, the
first portion 14 and the second portion 18 are beam shaped and are
substantially parallel to the longitudinal axis 25 of the
suspension member 10. Alternatively, it is possible to have the
first portion 14 and the second portion 18 curved around the
central portion 16 such that they oscillate around the longitudinal
axis 25. Alternatively, the first portion 14 and the second portion
18 may have a trapezoid hexagonal cross-section.
[0011] As shown in FIG. 1, the suspension member 10 is formed of
substantially contiguous layers of fibers generally represented by
reference numeral 20. In order to obtain the suspension member 10
of the desired thickness multiple layers of the fiber 20 are
superimposed on each other as shown in FIG. 2. Although in the
drawings only eight layers of fibers are shown to be superimposed
on each other it is possible to have less that eight layers of
fiber or more than eight layers of fiber. The thickness of the
suspension member 10 is generally represented as T. Preferably, the
fibers 20 used to form the suspension member 10 are dry
unidirectional fibers such as synthetic fibers, metal fibers,
animal fibers or vegetable fibers. Alternatively, it is also
possible to use pre-impregnated fibers where the fibers have been
pre treated with a resin. The liquid resin typically used is
conventional and can take the form of a polyester, vinyl ester,
epoxy, phenolic, cyanate ester and/or any other resin.
[0012] As shown in FIGS. 1 and 2, the multiple layers of fibers 20
that form the suspension member 10 typically comprise an upper
fiber layer 22A, 22B, 22C and 22D, jointly represented as upper
fiber layers 22 and a lower fiber layer 24A, 24B, 24C and 22D
jointly represented as lower fiber layers 24. The upper fiber layer
22A, 22B, 22C and 22D are superimposed on each other to obtain the
desired thickness generally represented by T1. Like the upper fiber
layer 22, the lower fiber layers 24A, 24B, 24C and 24D, are
superimposed on each other to obtain the desired thickness T2. The
total thickness T of the suspension member 10 is the total of the
thickness T1 of the upper fiber layers 22 and the thickness T2 of
the lower fiber layers 24. Although in the drawings only four upper
fiber layers 22 and lower fiber layers 24 are shown, it must be
understood that more than four layers of fibers may be used to
define the thickness T of the suspension member 10. Alternatively,
it is possible that the upper fiber layer 22 includes more fiber
layer than of lower fiber layers 24, or visa versa.
[0013] As shown in the FIG. 1, the upper fiber layers 22 extend
horizontally from the first portion 14, to the second portion 18 by
curving around the central portion 16. Alternatively it is possible
that some of the upper fiber layers 22 do not curve around the
central portion 16 such that they are straight extend only in the
first portion 14 or the second portion 18 without curving around
the central portion 16. Similarly, the lower fiber layer 24 extends
form the first portion 14 to the second portion 18 by curving
around the central portion 16. Alternatively, it is possible that
some of the lower layer of fibers extend only in the first portion
14 or the second portion 18. These fibers do not generally curve
around the central portion 16.
[0014] As shown in FIG. 1, in order to obtain the suspension member
10 of the present invention the upper fiber layers 22 and the lower
fiber layers 24 run substantially parallel to each other. Typically
the upper fiber layer 22A and the lower fiber layer 24A interface
along the longitudinal axis 25 of the suspension member 10 at the
first portion 14 and the second portion 18. At the central portion
16, the upper fiber layer 22A and the lower fiber layer 24A split
such that the upper fiber layer 22A curves above the longitudinal
axis 25 and the lower fiber layer 24A curves below the longitudinal
axis 25 of the suspension member 10. As shown in FIG. 1, at the
first portion 14 and the second portion 18, the upper fiber layer
22A and the lower fiber layer 24A are integrally joined to form a
beam like structure. At the central portion 16, the upper fiber
layer 22A and the lower fiber layer 24A are split to define an
opening 26.
[0015] Alternatively, it is also possible to form the suspension
member 10 where a bushing or a pin 32 (as shown in FIG. 3) is
molded in the central portion 16. Therefore, in such instance the
bushing 32 will define the opening 26. In the case where a bushing
32 is used to define the opening 26, the upper fiber layers 22
extend from the first portion 14 and curve around the upper part
32A of the bushing 32 to the second portion 18 of the suspension
member 10. Similarly, the lower fiber layers 24 extend from the
first portion 14 and curve around the lower part 32B of the bushing
32 to the second portion 18 of the suspension member 10.
Preferably, the bushing 32 is removable after the tooling process.
Alternatively, it is possible that the bushing 32 is not removed
after the tooling process and is an integral part of the suspension
member 10 (as shown in FIG. 3).
[0016] After the multiple layers of fibers 20 are superimposed on
each other to form the first portion 14, the central portion 16 and
the second portion 18, the structure is molded to form the
suspension member 10 (as shown in FIG. 2) where the resin is cured
using techniques that are conventional in the art. Preferably,
during the molding operation, the upper fiber layer 22A and the
lower fiber layer 24A are integrally connected along the
longitudinal axis 25 in the first portion 14 and the second portion
18 of the suspension member 10.
[0017] As discussed above, the suspension member 10 is typically
subject to high loads and stress. Since the upper fiber layer 22A
and the lower fiber layer 24A are split in the area 28 of the
opening 26, the opening 26 creates a high stress concentration in
area 28. Therefore, when the suspension member 10 is subject to
high load and stresses, the upper fiber strand 22A and the lower
fiber strand 24A have a tendency to separate along the longitudinal
axis 25. In order to prevent separation of the upper fiber layer
22A and the lower fiber layer 24A, the area 28 is reinforced by a
reinforcing fiber 30, as shown in FIG. 2. Preferably the
reinforcing fiber used is fiberglass. Alternatively, aramid fibers
or organic fibers such as those commercially available from E.I. du
Pont de Nemours & Co under the trademark KEVLAR.RTM. may be
used as reinforcing fiber 30. It is also possible to use carbon
fibers as a reinforcing fiber. Preferably, the reinforcing fiber 30
is stitched through the thickness T of the suspension member 10
around the areas 28 using an industrial sewing machine (not shown).
Preferably, multiple stitches of the reinforcing fiber 30 are
present to hold together the upper layer of fiber 22 and the lower
layer of fiber 24. As shown in FIG. 2, preferably the reinforcing
fiber 30 is stitched such that the reinforcing fiber 30 is
substantially perpendicular to the longitudinal axis 25 of the
suspension member 10. Preferably, the reinforcing fiber 30 is
stitched such that the multiple stitches are displaced along the
transverse axis 27 of the suspension member 10. Alternatively, the
multiple stitches of the reinforcing fiber 30 may be stitched such
that they are longitudinally displaced along the longitudinal axis
25 of the suspension member 10 (as shown in FIG. 3). Further,
reinforcing fiber 30 extends such that the upper fiber layer 22A
and the lower fiber layer 24A are held together in the area 28
around the opening 26.
[0018] As shown in FIG. 3, in the suspension member 10 where a
bushing 32 defines the opening 26, a gap 34 is defined in the area
28 between the sides of the bushing 32 and the first portion 14 and
the second portion 18. In order to reinforce the upper fiber layer
22A and the lower fiber layer 24A, the reinforcing fibers 30 are
preferably stitched using an industrial machine by the process
described above. Preferably where the bushing 32 is used to define
the opening 26 the reinforcing fiber 30 are displaced along the
longitudinal axis 25 of the suspension member 10. Alternatively, it
is possible to stitch the reinforcing fibers 30 along the
longitudinal axis 25 and transverse axis 27. The above process of
reinforcing the area 28 around the opening 26 is preferably
performed prior to the molding process. However, it is possible to
reinforce the area 28 after the suspension member 10 is molded.
[0019] As any person skilled in the art will recognize from the
previous description and from the figures and claims, modifications
and changes can be made to the preferred embodiments of the
invention without departing from the scope of the invention.
* * * * *