U.S. patent application number 11/561622 was filed with the patent office on 2007-04-05 for structural reinforcement system for automotive vehicles.
This patent application is currently assigned to L&L Products, Inc.. Invention is credited to William J. Barz, Thomas L. Coon, Michael J. Czaplicki.
Application Number | 20070075569 11/561622 |
Document ID | / |
Family ID | 27054243 |
Filed Date | 2007-04-05 |
United States Patent
Application |
20070075569 |
Kind Code |
A1 |
Barz; William J. ; et
al. |
April 5, 2007 |
STRUCTURAL REINFORCEMENT SYSTEM FOR AUTOMOTIVE VEHICLES
Abstract
An automotive vehicle frame reinforcement system has a skeleton
member designed to be secured to a vehicle frame, such as a roof or
pillar section. An expandable material, such as an epoxy-based
reinforcing foam, is disposed on the skeleton member. Once the
system is attached to the frame, the foam expands and cures during
an automobile assembly operation, bonding the reinforcement system
to the frame. As a result, the reinforcement system provides
enhanced load distribution over the vehicle frame without adding
excessive weight.
Inventors: |
Barz; William J.; (St.
Clair, MI) ; Coon; Thomas L.; (Lapeer, MI) ;
Czaplicki; Michael J.; (Rochester, MI) |
Correspondence
Address: |
DOBRUSIN & THENNISCH PC
29 W LAWRENCE ST
SUITE 210
PONTIAC
MI
48342
US
|
Assignee: |
L&L Products, Inc.
Romeo
MI
48065
|
Family ID: |
27054243 |
Appl. No.: |
11/561622 |
Filed: |
November 20, 2006 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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11136058 |
May 24, 2005 |
7160491 |
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11561622 |
Nov 20, 2006 |
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10862645 |
Jun 7, 2004 |
6938947 |
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11136058 |
May 24, 2005 |
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10603674 |
Jun 25, 2003 |
6921130 |
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10862645 |
Jun 7, 2004 |
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09655965 |
Sep 6, 2000 |
6619727 |
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10603674 |
Jun 25, 2003 |
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09502686 |
Feb 11, 2000 |
6467834 |
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09655965 |
Sep 6, 2000 |
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Current U.S.
Class: |
296/203.02 |
Current CPC
Class: |
B62D 29/002 20130101;
B62D 25/04 20130101 |
Class at
Publication: |
296/203.02 |
International
Class: |
B60R 27/00 20060101
B60R027/00 |
Claims
1-21. (canceled)
22. A method of forming a reinforcement member for reinforcing a
structure of an automotive vehicle, the method comprising: molding
a plastic skeleton member with a plurality of ribs wherein at least
two ribs of the plurality of ribs are spaced apart from and
opposing each other or wherein at least two ribs of the plurality
of ribs intersect each other; adhering a foamable structural
reinforcement material to the skeleton member to form a
reinforcement member, wherein: i. the foamable structural
reinforcement material includes a blowing agent and a curing agent
and is substantially tack free to the touch; ii. the foamable
structural reinforcement material is configured to activate to foam
and cure upon exposure to an elevated temperature experienced in an
automotive assembly operation; and iii. the skeleton member is
shaped to correspond to a cavity that is defined by a structure of
an automotive vehicle, the structure being selected from a pillar,
a roof rail, a frame member or a combination thereof.
23. A method as in claim 22 wherein the reinforcement member
includes one or more mechanical fasteners for at least temporarily
locating the reinforcement member within the cavity prior to
activation of the reinforcement material.
24. A method as in claim 22 wherein the skeleton member includes an
opening suitable for passage of a component therethrough.
25. A method as in claim 22 wherein the structure is an
A-pillar.
26. A method as in claim 22 wherein the curing includes
cross-linking of the reinforcement material and the reinforcement
material includes a phenoxy material and wherein the plastic
skeleton member is nylon.
27. A method as in claim 22 wherein the plurality of ribs are
beam-like in function for strengthening the member.
28. A method as in claim 22 wherein the reinforcement material is
configured to distribute loads over a surface of the skeleton
member and at least one rib of the plurality of ribs is in
non-parallel relationship to the surface over which the loads are
to be distributed.
29. A method as in claim 22 wherein the member is such that, over
at least one half of the member, the cross-sectional area of the
member is less than 50% of the a silhouette profile of the
member.
30. A method as in claim 22 wherein the skeleton member exhibits a
weight reduction of 70% as compared to a solid structure of the
same material.
31. A method as in claim 22 wherein the structure is a lower rail
of the vehicle.
32. A method as in claim 22 wherein the skeleton member includes a
first longitudinal outwardly facing surface opposite a second
outward facing longitudinal surface and wherein both the first
surface and the second surfaces support reinforcement material and
the at least two of the plurality of ribs adjoin the first surface,
the second surface or both.
33. A method as in claim 22 wherein the skeleton members includes
the intersecting ribs, which include at least one laterally
extending rib and at least one longitudinally extending rib.
34. A method as in claim 22 wherein the at least two ribs are
substantially devoid of the reinforcement material.
35. A method as in claim 22 wherein the step of adhering the
reinforcement material includes molding the reinforcement material
upon the skeleton member.
36. A method as in claim 22 wherein the skeleton member and the
structural material are configured to cooperatively seal the cavity
to block passage of materials through the cavity.
37. A method of forming a reinforcement member for reinforcing a
structure of an automotive vehicle, the method comprising:
injection molding a plastic skeleton member with a plurality of
ribs wherein at least two ribs of the plurality of ribs are spaced
apart from each other along a length of the skeleton member and
opposing each other and wherein at least two ribs of the plurality
of ribs intersect each other; molding and adhering a foamable
structural reinforcement material to the skeleton member to form a
reinforcement member, wherein: i. the foamable structural
reinforcement material includes an epoxy resin, a blowing agent and
a curing agent and is substantially tack free to the touch; ii. the
foamable structural reinforcement material is configured to
activate to foam and cure upon exposure to an elevated temperature
experienced in an automotive assembly operation; and iii. the
skeleton member is shaped to correspond to a cavity that is defined
by a structure of an automotive vehicle, the structure being
selected from a pillar, a roof rail, a frame member or a
combination thereof.
38. The method of claim 37 wherein the skeleton member includes one
or more extensions extending therefrom and wherein the skeleton
member includes an opening suitable for passage of a component
therethrough and wherein the structure is a lower rail of the
vehicle.
39. A method as in claim 37 wherein the reinforcement member
includes one or more mechanical fasteners for at least temporarily
locating the reinforcement member within the cavity prior to
activation of the reinforcement material and wherein the curing
includes cross-linking of the reinforcement material and the
reinforcement material includes a phenoxy material and wherein the
plastic skeleton member is nylon and.
40. A method as in claim 37 wherein the plurality of ribs are
beam-like in function for strengthening the member and wherein the
reinforcement material is configured to distribute loads over a
surface of the skeleton member and at least one rib of the
plurality of ribs is in non-parallel relationship to the surface
over which the loads are to be distributed
41. A method as in claim 37 wherein the member is such that, over
at least one half of the member, the cross-sectional area of the
member is less than 50% of the a silhouette profile of the member
and wherein the skeleton member exhibits a weight reduction of 70%
as compared to a solid structure of the same material.
42. A method as in claim 37 wherein the skeleton member includes a
first longitudinal outwardly facing surface opposite a second
outward facing longitudinal surface and wherein both the first
surface and the second surfaces support reinforcement material and
the at least two of the plurality of ribs adjoin the first surface,
the second surface or both.
43. A method as in claim 37 wherein the skeleton members includes
the intersecting ribs, which include at least one laterally
extending rib and at least one longitudinally extending rib and
wherein the at least one laterally extending rib and the at least
one longitudinally extending rib of the first portion and are
substantially devoid of the foam.
Description
FIELD OF THE INVENTION
[0001] The present invention relates generally to a reinforced
structural member for use in strengthening the stiffness and
strength of a frame assembly. More particularly, the invention
relates to a vehicle frame system of an automotive vehicle that is
reinforced by a member coated over a portion of its surface with an
expandable material, the combination of which increases the
structural stiffness and strength of the automotive vehicle.
BACKGROUND OF THE INVENTION
[0002] For many years the transportation industry has been
concerned with designing reinforced structural members that do not
add significantly to the weight of a vehicle. U.S. Pat. Nos.
5,755,486; 4,901,500; and 4,751,249 described prior art reinforcing
devices. While these prior art devices may be advantageous in some
circumstances, there is needed a simple low cost structure that
permits coupling the reinforcement member to a variety of
structures of varying geometric configurations. In the automotive
industry there is also a need for a relatively low cost system for
reinforcing automotive vehicle frame structures.
SUMMARY OF THE INVENTION
[0003] The present invention is directed to a structural
reinforcement system, and particularly one for reinforcing
automotive vehicle frame structures, such as (without limitation)
vehicle roof and pillar structures. The system generally employs a
skeleton member adapted for stiffening the structure to be
reinforced and helping to redirect applied loads. In use, the
skeleton member is in contact, over at least a portion of its outer
surface, with an energy absorbing medium, and particularly heat
activated bonding material. In a particular preferred embodiment,
the skeleton member is a molded metal, or composite frame and it is
at least partially coated with foamable epoxy-based resin, such as
L5206, L5207, L5208 or L5209 structural foam commercially available
from L & L Products of Romeo, Mich.
[0004] In one embodiment the skeleton member along with a suitable
amount of bonding or load transfer medium is placed in a cavity
defined within an automotive vehicle, such as a vehicle roof
structure, pillar structure or both. The bonding medium is
activated to accomplish expansion of the resin in the space defined
between the skeleton member and the wall structure defining the
cavity. The resulting structure includes the wall structure joined
to the skeleton member with the aid of the structural foam.
DETAILED DESCRIPTION OF THE DRAWINGS
[0005] The features and inventive aspects of the present invention
will become more apparent upon reading the following detailed
description, claims, and drawings, of which the following is a
brief description:
[0006] FIG. 1 is a perspective view of aspects of an automotive
vehicle roof and pillar structure, illustrating an A-Pillar and
B-Pillar.
[0007] FIG. 2 is a perspective view of a skeleton member coated
with an expandable resin in accordance with the present
inventions.
[0008] FIG. 3 is another perspective view of the structure shown in
FIG. 2.
[0009] FIG. 4 is a sectional view showing a coated skeleton member
prior to activation of an expandable resin.
[0010] FIG. 5 illustrates the structure of FIG. 4 after the
expandable resin has been expanded.
[0011] FIG. 6 is a perspective view of another illustrative
structure in accordance with the present invention.
[0012] FIG. 7 is a side elevation view of the structure of FIG.
6.
[0013] FIG. 8 illustrates yet another structure in accordance with
the present invention.
[0014] FIG. 9 illustrates the structure of FIG. 8 employed
combination with a vehicle pillar structure.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENT
[0015] FIG. 1 illustrates an example of an automotive vehicle
showing portions of a frame structure. As will be appreciated, it
is common for such structures to include a plurality of hollow
vehicle frame members that are joined to define the frame. One such
structure, for purposes of illustration (without limitation) is a
vehicle roof and pillar structure. As will be recognized, included
in the roof and pillar structure may also be windows, sunroofs or
other removable tops, vehicle doors and door components, headliners
(with or without overhead accessories), or the like. As discussed
later, other vehicle frame members are also contemplated within the
scope of the present invention.
[0016] While FIG. 1 illustrates an A-Pillar 12 and B-Pillar 14,
other pillars may likewise be employed in accordance with the
present invention. In FIG. 1 there is shown also a portion of the
roof structure 16 that bridges the A-Pillar 12 and B-Pillar 14.
[0017] Depending upon vehicle design, it is possible that the roof
structure 16 bridging the A-Pillar and B-Pillar is relatively
indistinguishable between the A-Pillar and B-Pillar such that the
A-Pillar structure and B-Pillar structure effectively adjoin one
another. In such instances the uppermost portion of the pillar
structure is deemed the roof structure.
[0018] Reinforcement of the roof and pillar sections is
accomplished by locating one or more skeleton members in accordance
with the present invention in a hollow or cavity portion of the
roof or pillar. FIG. 1 illustrates examples of this by showing a
first member 16, a second member 18 and a third member 20 in such
locations. The members 16, 18 and 20 preferably are sealingly
secured to at least one of the roof and pillar sections by a
bonding material, which upon heat activation produces adhesion to
skeleton members to help secure the members and the walls defining
the hollow from movement within the hollow portion.
[0019] Though other heat activated materials are possible, a
preferred heat activated material is an expandable plastic, and
preferably one that is foamable. A particularly preferred material
is an epoxy-based structural foam. For example, without limitation,
in one embodiment, the structural foam is an epoxy-based material,
including an ethylene copolymer or terpolymer that may possess an
alpha-olefin. As a copolymer or terpolymer, the polymer is composed
of two or three different monomers, i.e., small molecules with high
chemical reactivity that are capable of linking up with similar
molecules.
[0020] A number of epoxy-based structural reinforcing foams are
known in the art and may also be used to produce the structural
foam. A typical structural foam includes a polymeric base material,
such as an epoxy resin or ethylene-based polymer which, when
compounded with appropriate ingredients (typically a blowing and
curing agent), expands and cures in a reliable and predicable
manner upon the application of heat or the occurrence of a
particular ambient condition. From a chemical standpoint for a
thermally-activated material, the structural foam is usually
initially processed as a flowable thermoplastic material before
curing. It will cross-link upon curing, which makes the material
incapable of further flow.
[0021] An example of a preferred structural foam formulation is an
epoxy-based material that is commercially available from L&L
Products of Romeo, Mich., under the designations L5206, L5207,
L5208 and L5209. One advantage of the preferred structural foam
materials 14 over prior art materials is that the preferred
materials can be processed in several ways. The preferred materials
can be processed by injection molding, extrusion compression
molding or with a mini-applicator. This enables the formation and
creation of part designs that exceed the capability of most prior
art materials. In one preferred embodiment, the structural foam (in
its uncured state) generally is dry or relatively free of tack to
the touch.
[0022] While the preferred materials for fabricating the structural
foam have been disclosed, the structural foam can be formed of
other materials provided that the material selected is
heat-activated or otherwise activated by an ambient condition (e.g.
moisture, pressure, time or the like) and cures in a predictable
and reliable manner under appropriate conditions for the selected
application. One such material is the epoxy based resin disclosed
in U.S. patent application Ser. No. 09/268,810, the teachings of
which are incorporated herein by reference, filed with the United
States Patent and Trademark Office on Mar. 8, 1999 by the assignee
of this application. Some other possible materials include, but are
not limited to, polyolefin materials, copolymers and terpolymers
with at least one monomer type an alpha-olefin, phenol/formaldehyde
materials, phenoxy materials, and polyurethane materials with high
glass transition temperatures. See also, U.S. Pat. Nos. 5,766,719;
5,755,486; 5,575,526; and 5,932,680, (incorporated by reference).
In general, the desired characteristics of the structural foam
include relatively high stiffness, high strength, high glass
transition temperature (typically greater than 70 degrees Celsius),
and good corrosion resistance properties. In this manner, the
material does not generally interfere with the materials systems
employed by automobile manufacturers.
[0023] In applications where a heat activated, thermally expanding
material is employed, an important consideration involved with the
selection and formulation of the material comprising the structural
foam is the temperature at which a material reaction or expansion,
and possibly curing, will take place. For instance, in most
applications, it is undesirable for the material to be reactive at
room temperature or otherwise at the ambient temperature in a
production line environment. More typically, the structural foam
becomes reactive at higher processing temperatures, such as those
encountered in an automobile assembly plant, when the foam is
processed along with the automobile components at elevated
temperatures or at higher applied energy levels, e.g., during
painting preparation steps. While temperatures encountered in an
automobile assembly operation may be in the range of about
148.89.degree. C. to 204.44.degree. C. (about 300.degree. F. to
400.degree. F.), body and paint shop applications are commonly
about 93.33.degree. C. (about 200% or slightly higher. If needed,
blowing agent activators can be incorporated into the composition
to cause expansion at different temperatures outside the above
ranges.
[0024] Generally, suitable expandable foams have a range of
expansion ranging from approximately 0 to over 1000 percent. The
level of expansion of the structural foam 14 may be increased to as
high as 1500 percent or more. Typically, strength is obtained from
products that possess low expansion.
[0025] Referring now to FIG. 2, there is shown one example of a
first reinforcement member 16 in accordance with the present
invention. This illustrated embodiment is useful, for instance, for
reinforcing the juncture between an automotive vehicle roof 22 and
the A-Pillar. The first member 16 has a first portion 24 adapted
for placement in a cavity defined in a vehicle roof structure, and
a second portion 26 adapted for placement in a cavity defined in a
vehicle pillar, such as an A-Pillar as illustrated. Preferably the
cross sectional silhouette of both the first portion 24 and the
second portion 26 is generally complementary to the walls of the
cavity defined in opposing roof or pillar structure. Though the
member may also be solid, the member preferably includes a skeleton
frame that is prepared to minimize weight while still achieving
desired rigidity. Accordingly, the skeleton frame preferably is
designed to employ a plurality of ribs that effectively are
beamlike (e.g. I-beam) in function, thus helping to selectively
strengthen the member. The ribs are illustrated in FIGS. 2 and 3
generally running orthogonal to one another. However, this is not
intended as limiting, as the rib configuration may be varied
depending upon the desired outcome.
[0026] In general, however, a rib is placed adjacent to, and in
generally non-parallel relationship to a surface over which loads
will be distributed. In FIG. 2, by way of illustration, a plurality
of first ribs 28 are located adjacent to a surface of the member
(shown covered with expandable material 30). FIG. 3 also shows how
the ribs 28 (reference numerals illustrating some of the ribs, but
not all) can be configured relative to one another to provide
additional stabilization. In general, because of the relatively
high bending moment of the ribs, without unduly increasing weight
of the member, rigidity can be increased in locations where loads
are anticipated by selective design and placement of the ribs. At
the same time, enhanced load distribution is possible from the
continuous surfaces and foam employed with the ribs to spread
energy. Moreover, weight savings can be achieved by such design.
For instance, the structure of the member is also such that over at
least one quarter, preferably one half and more preferably greater
than about three quarter of the length of the member at any given
point between the ends of said member, the cross-sectional area of
the member is less than 75%, more preferably less than 50% and
still more preferably less than 20% of the overall area for a
silhouette profile taken such point. In this manner, weight
reductions of up to about 50%, more preferably about 70%, and still
more preferably about 90%, are possible as compared with a solid
structure of the same material.
[0027] It should be appreciated that other devices for securing the
members 16, 18, and 20 to the vehicle frame may be employed,
including suitable fasteners, straps, or other mechanical
interlocks. Through-holes 32 may also be defined within the
structure to assist in vehicle manufacturing. In a particularly
preferred embodiment, the skeleton members of the present invention
are injection molded plastics, such as nylons. However, other
materials and manufacturing techniques may be employed similarly to
achieve like results. For instance, high strength to weight metal
components, such as aluminum, titanium, magnesium or the like, may
be employed, as well as polymer composites such as a layered
polymer with fibers capable of compression molding to generate
strength.
[0028] Returning to FIG. 1, when employed in an automotive vehicle
in accordance with the present invention, the skeleton members,
particularly when coated with an expandable material (such as a
heat activated epoxy based foam) can reinforce the region for which
it is used by the combination of increased stiffening from the
presence of beam-like ribs and load distribution through the
combination of relatively high surface area continuous surfaces and
an expandable material.
[0029] In another preferred embodiment, the expandable material,
upon expansion will serve as a sealant for blocking the passage of
fluids or other elements through the cavity. Thus, in such
embodiment, it is preferred that the expandable material is
provided continuously about generally the entirety of the periphery
of any portion of the skeleton member that does not sealingly
contact the automobile frame structure. FIG. 5 illustrates this by
showing how skeleton member 16 coated with an expandable material
30 (shown in FIG. 4) is sealed in place upon activation of the
material 30 (shown expanded in FIG. 5).
[0030] FIGS. 6 through 9 illustrate other embodiments in accordance
with the present invention. In FIGS. 6 and 7, there is shown a
reinforcement member 18 adapted for a pillar of an automotive
vehicle. The structure of the skeleton member employs a plurality
of ribs 34 adjoining one or more continuous surfaces 36 (shown
coated with an expandable material 38).
[0031] The expandable material is shown in its expanded state. As
the skilled artisan will appreciate, not all ribs are shown, and
the specific design of each rib configuration will vary depending
upon its intended use, and the geometry of the region being
reinforced (e.g. walls 40 and 42 of the vehicle frame structure
defining the cavity). Further expandable material may be employed
in contact with the ribs.
[0032] FIGS. 8 and 9 illustrate yet another embodiment according to
the present invention. In this embodiment, a skeleton member 20
having a plurality ribs 44 and generally continuous surfaces (shown
coated with a layer 46) is fabricated to also include structure for
facilitating vehicle manufacture. Specifically, the embodiment
shown includes a plurality of through-holes 48, for enabling body
shop weld access or the like. As shown in FIG. 9, in this
embodiment, the expandable material layer 46, upon expansion,
covers the circumference of a cross section of the structure.
[0033] The skilled artisan will appreciate that the use of the
reinforcements disclosed herein is not intended as being limited
only to illustrate the locations shown in FIG. 1. They can be used
in any location within an automotive vehicle frame. For instance,
other reinforced locations are also possible including but not
limited to pillar to door regions, roof to pillar, mid-pillar, roof
rails, windshield or other window frames, deck lids, hatches,
removable top to roof locations, other vehicle beltline locations,
motor rails, lower sills, cross members, lower rails, and the like.
Moreover, vehicle roof tops may be reinforced to support additional
loads in accordance with the present invention. In the same manner
as was described above in the context of a roof and pillar system,
a reinforcement frame member having an expandable material thereon
is placed in a cavity defined in the vehicle frame structure. The
material is expanded to help secure the reinforcement in place.
[0034] The preferred embodiment of the present invention has been
disclosed. A person of ordinary skill in the art would realize
however, that certain notifications would come within the teachings
of this invention. Therefore, the following claims should be
studied to determine the true scope and content of the
invention.
* * * * *