U.S. patent application number 10/464306 was filed with the patent office on 2004-12-23 for method of forming a structural member.
Invention is credited to Billotto, Frank, Sophiea, Daniel.
Application Number | 20040255546 10/464306 |
Document ID | / |
Family ID | 33517264 |
Filed Date | 2004-12-23 |
United States Patent
Application |
20040255546 |
Kind Code |
A1 |
Sophiea, Daniel ; et
al. |
December 23, 2004 |
Method of forming a structural member
Abstract
The present invention relates to a method of forming a
reinforced hollow member. The method comprises the step of
inserting a structural reinforcement insert into a hollow member.
The structural reinforcement insert is then positioned in the
hollow member such that the structural reinforcement insert and
hollow member define at least one fluid passageway. A structural
adhesive is applied in the fluid passageway to lock the structural
reinforcement insert in the hollow member.
Inventors: |
Sophiea, Daniel; (Lake
Orion, MI) ; Billotto, Frank; (Oakland Township,
MI) |
Correspondence
Address: |
Richard W. Hoffmann
PO Box 70098
Rochester Hills
MI
48307
US
|
Family ID: |
33517264 |
Appl. No.: |
10/464306 |
Filed: |
June 18, 2003 |
Current U.S.
Class: |
52/745.19 ;
52/741.1 |
Current CPC
Class: |
B62D 29/002
20130101 |
Class at
Publication: |
052/745.19 ;
052/741.1 |
International
Class: |
E04G 023/00 |
Claims
What is claimed is:
1. A method of forming a foam filled hollow member comprising:
inserting a structural reinforcement insert into the hollow member;
positioning the insert in the hollow member such that the insert
and hollow member define at least one fluid passageway; applying a
structural adhesive in the fluid passageway to lock the insert in
the hollow member.
2. The method of claim 1 further comprising the use of a
non-expandable structural adhesive.
3. The method of claim 1 further comprising performing an E-coating
process and draining the E-coating fluids through the fluid
passageway.
4. The method of claim 2 further comprising heating the structural
adhesive.
5. The method of claim 2 further comprising applying the structural
adhesive as a liquid into the passageway.
6. The method of claim 2 further comprising applying the structural
adhesive as a paste into the passageway.
7. The method of claim 2 further comprising utilizing a one
component epoxy as the structural adhesive.
8. The method of claim 2 further comprising utilizing a two
component epoxy as the structural adhesive.
9. The method of claim 2 further comprising utilizing a foam as the
structural reinforcement insert.
10. The method of claim 9 further comprising placing a shell about
the foam to form the structural reinforcement insert.
11. The method of claim 9 further comprising selecting the foam
from the group comprising polyurethane, polyisocyanurate and hybrid
foam.
12. The method of claim 1 further comprising positioning the insert
by placing a locating pin on the insert in an opening in the hollow
member.
Description
FIELD OF THE INVENTION
[0001] The present invention relates to structural reinforced
parts. The structural reinforced parts are particularly useful for
improving the structural integrity through section stabilization,
energy management or energy absorption or dampening the sound of
vehicle structural members, such as frame rails, pillar sections,
rocker panels, body structures, deck lids or the like.
BACKGROUND OF THE INVENTION
[0002] Reducing automotive vehicle weight is important to meet ever
more stringent fuel economy and environmental standards. In meeting
these fuel economy and environmental standards, automotive
designers must also seek to improve vehicle safety and quietness.
Typically, to improve fuel consumption, lighter and thinner
materials are being used in vehicle construction. The use of these
materials reduces the durability, stiffness, energy absorption and
the overall safety performance of an automobile. To increase the
structural integrity of the lighter and thinner components,
structural foams have been added to the interior of hollow
components.
[0003] In one prior method, a foamable material is introduced into
the hollow component. The foamable material is then foamed on
mixing inside the component. Foaming of this type tends to fill
functional holes and the foam escaping from functional holes. These
functional holes are used, for example, to mount other components.
One such method of this type is shown in U.S. Pat. No. 5,678,826, A
Method Of Introducing A Foam is described where a foamable material
is located within the hollow member by removable plug extending
through the wall of the hollow member. After the foamable material
is foamed, the plug is removed.
[0004] Another attempt to increase the structural integrity of a
hollow member is to provide a structural reinforcing part, such as
a preformed foam part, within the hollow member. The structural
reinforcing parts are typically coated prior to placing the
structural reinforcing part in the hollow member with an expandable
composition. The composition expands when heated to a certain
temperature. Typically, the expandable composition expands to
contact the inner walls of the structural member being supported.
Upon expansion, the expandable composition functions to hold the
structural reinforcing member in place permanently by adhering to
the inner wall of the structural member. The expanded composition
also helps transfer a load from the metal component from the sheet
metal wall of the hollow member to the inner reinforcement to sheet
metal wall of the opposite side of the hollow tube member. The use
of expandable compositions provides manufacturing challenges due to
the need to coat the reinforcing structural component prior to
insertion into the hollow member and limits the shelf life of the
components. Further, use of such expandable materials does not
optimize the load transfer through the structural part because the
heat expandable layer can become a weak interlayer.
SUMMARY OF THE INVENTION
[0005] The present invention relates to a method of forming a
reinforced structural member. The method comprises the step of
inserting a structural reinforcement insert into a hollow member.
The structural reinforcement insert is then positioned in the
hollow member such that the structural reinforcement insert and
hollow member define at least one fluid passageway. A structural
adhesive is applied in the fluid passageway to lock the structural
reinforcement insert in the hollow member.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] Advantages of the present invention will be more fully
appreciated from the detailed description when considered in
connection with accompanying drawings of presently preferred
embodiments which are given by way of illustration only and are not
limiting wherein:
[0007] FIG. 1 is a cross-sectional view of one embodiment of the
present invention prior to the introduction of the structural
adhesives;
[0008] FIG. 2 is a cross-sectional view of a hollow tubular member
after the structural adhesive is applied;
[0009] FIG. 3 is a cross-sectional view of a second embodiment of
the present invention prior to the introduction of the structural
adhesives;
[0010] FIG. 4 is a cross-sectional view of a hollow tubular member
after the structural adhesive is applied;
[0011] FIG. 5 is a cross-sectional view partially broken away
showing another embodiment of the present invention;
[0012] FIG. 6 is a cross-sectional view partially broken away
showing another embodiment of the present invention;
[0013] FIG. 7 is a cross-sectional view showing another embodiment
of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0014] The following description of the preferred embodiment(s) is
merely exemplary in nature and is in no way intended to limit the
invention, its application, or uses.
[0015] FIG. 1 shows a cross-sectional view of a structural member
generally shown at 10 in accordance with one embodiment of the
present invention. The structural member 10 is shown prior to final
assembly and application of a structural adhesive. The structural
member 10 includes a hollow member generally indicated at 12. The
hollow member 12 can take any configuration. The hollow member 12
can comprise any hollow member in a vehicle, such as, for example,
vehicle frame rails, pillars, rocker panels, body structures, deck
lids, or the like.
[0016] The hollow member 12 is shown to comprise metal. However, it
will be appreciated that the hollow member 12 can comprise any
suitable material such as plastic, ceramic or the like.
Additionally, the hollow member 12 is shown to comprise two
segments that are fabricated, such as by welding, to form a unitary
member. It will be appreciated that any method of forming the
hollow member 12 is within the scope of the present invention.
[0017] A structural reinforcing insert generally indicated at 14 is
placed in the hollow member 12. The insert 14 includes a body 15.
Preferably, the structural reinforcing insert 14 is made by molding
a rigid closed-cell polyurethane, polyisocyanurate or hybrid foam.
Additionally, the insert 14 may include any light weight, high
strength cellular plastic or membrane. The structural reinforcing
insert 14 includes locating pins generally indicated at 16
extending from the body 15. The locating pin 16 is adapted to be
received within a mounting hole 18 in the walls 20 of the hollow
member 12. The structural reinforcing insert 14 is positioned
within the hollow member 12 by placing the locating pin 16 in the
mounting hole 18 of the hollow member 12.
[0018] The insertion of the insert 14 into the hollow member 12 may
be accomplished in any suitable manner such as by placing it by
hand into the hollow member 12. The locating pin 16 is positioned
in the mounting hole 18 of the hollow member 12. It will be
appreciated that while only one locating pin 16 is shown on the
insert 14, multiple locating pins 16 may be used. In such a case,
multiple mounting holes 18 are likewise used.
[0019] In one embodiment, as shown in FIGS. 1 and 2, a fluid
passageway 22 is defined between the outer surface of the insert 14
and the walls 20 of hollow member 12. The fluid passageway 22
provides at least two purposes. First, the fluid passageway 22
allows any fluids that may be within the hollow member 12 to flow
within the hollow member 12. Such fluids may be produced as a
result of an E-coating operation. Second, the fluid passageway 22
allows for the introduction and flow and defines the placement of
the structural adhesive.
[0020] The walls 20 of the hollow member 12 include one or more
holes 24. The holes 24 are in fluid communication with the fluid
passageways 22. The holes 24 allow fluids to flow out of the hollow
member 12. Further, the holes 24 and fluid passageways 22 provide a
fluid pathway to allow a structural adhesive 26 to be applied in
the fluid passageway 22 to fill fluid passageway 22 and thereby
lock the foam insert 14 with the hollow member 12.
[0021] More specifically, after the drainage of any fluid from the
hollow member 12, the structural adhesive 26 fills the fluid
passageway 22 and is used to adhere the foam insert 14 to the
hollow member 12. That is, the structural adhesive 26 fills the
fluid passageways 22 in such a manner that it locks the insert 14
within the hollow member to ultimately generate a composite
section. Preferably, the structural adhesive 26 comprises a
non-expandable structural adhesive. It is preferred that the
adhesive be heat curable. Suitable structural adhesives comprise
one component epoxy based adhesives. Such one component epoxy based
systems are sold under the trademarks BETAMATE.TM. by the Dow
Chemical Company and include BETAMATE.TM. Trade Products Nos.
73302, 73309, 73314, 73350, 73352, 1469 and 4601. It will be
appreciated that two component epoxy systems may also be used
within the scope of the present invention. Similarly, other
suitable structural adhesives may be used within the scope of the
present invention.
[0022] The structural adhesive 26 is applied as either a liquid or
a paste. As best seen in FIG. 2, a suitable applicator 29, shown
schematically in FIG. 2, injects or pumps the structural adhesive
26 through hole 24 and into fluid passageway 22. By utilizing a
non-expandable structural adhesive in liquid or paste form, the
structural adhesive 26 can be applied utilizing equipment
ordinarily found at the original equipment manufacturer. The use of
nonexpandable structural adhesive in connection with an insert 14
imparts strength and stiffness to the hollow member 12 while
significantly reducing the weight of the structural member 10. The
adhesive seals cavities in parts and improves rigidity to the body
structure contributing to enhanced NVH. Further, utilizing a
non-expandable structural adhesive, allows for higher load transfer
in the structural member, better reliability and less propensity
for surface deformation due to mismatch of the adhesive/metal
coefficient of linear thermal expansion. Additionally, there is no
need to apply an adhesive to the foam insert 14 prior to placing
the foam insert 14 into the hollow member.
[0023] As stated above, the insert 14 is preferably manufactured by
a molding process for each specific cavity or hollow member 12. The
molding process is designed to integrate the fluid passageways 22
into the insert 14. The fluid passageway 22 can take any suitable
configuration in the insert 14. The insert 14 is then placed in the
hollow member 12 prior a final assembly process or sheet metal
manufacturing facility prior to the final processing of the hollow
member 12. Once the fabrication of the hollow member 12 is
complete, the non-expandable structural adhesive 26 fills the fluid
passageway 22.
[0024] As shown in the embodiments of FIGS. 1 and 2, the fluid
passageway 22 is defined about the exterior of the insert 14 and
walls 20 of the hollow member 12. It will be appreciated that the
insert 14 may also contact the walls of the hollow member 12. In
such a case, the insert 14 will include one or more fluid
passageways 22' therethrough. Again, the fluid passageway 22' can
take any suitable configuration in the insert 14. This is shown in
the embodiment of FIGS. 3 and 4. As with the embodiment of FIGS. 1
and 2, the fluid passageways 22' of the embodiment shown in FIGS. 3
and 4 allow for drainage of any material from the hollow member
such as E-coat fluids and subsequently allows for the addition of
the structural adhesive 26 into the fluid passageway 22' to thereby
secure the insert 14 with the hollow member 12. In this embodiment,
the insert 14 fills a larger portion of the cavity in the hollow
member 12. Such a structure provides for increased reliability in
the application of the insert 14 in the hollow member 12. The
structural adhesive 26 then is used to secure the insert 14 in
place.
[0025] FIG. 5 shows another embodiment of the present invention. In
FIG. 5, the insert 14 includes an outer shell 28 about the foam
body 15. Preferably, the shell 28 has a configuration that clearly
matches the interior of the hollow member 12. The outer shell 28
jackets the foam material. This insert 14 is then placed into the
hollow member 12 to increase the strength and stiffness to help the
component handle higher loads and impacts. In this embodiment, it
is preferred that the outer shell 28 comprise an injection or blow
molded thermal plastic shell such as, for example, Nylon.
Additionally, a sheet metal shell may be used.
[0026] As shown in FIG. 5, the fluid passageway 22 is formed
between the outer shell 28 and the walls 20 of the hollow member
12. The outer shell 28 also is preferably disposed about the
locating pin 16 and extends through mounting hole 18. It will be
appreciated that the outer shell 28 can have fluid passageways 22
of any configuration.
[0027] While the locating pin 16 is shown to be molded with the
insert 14, it will be appreciated that the locating pin 16 may
comprise additionally an integrated locating pin in the wall 20 of
the hollow member 12 or a mechanical attachment. Such additional
locating pins are shown in FIGS. 6 and 7, respectively.
[0028] As shown in FIG. 6, the wall 20 of the hollow member 12
includes a locating pin 30. The pin 30 extends into the cavity
defined by the hollow member 12. The insert 14 includes an opening
32 for receiving the locating pin 30. In this embodiment, the
insert 14 is located within the cavity in the hollow member 12 by
placing the locating pin 30 in the opening 32. While the opening 32
is shown in outer shell 28, it will be appreciated that the opening
32 may be in the foam body 15 itself and used with or without an
outer shell 28.
[0029] FIG. 7 shows an alternate locating pin. As shown in FIG. 7,
the locating pin comprises a mechanical fastener, such as, for
example, a screw 34. The screw 34 is received within an opening 36
in the wall 20 of the hollow member 12. Additionally, the screw 34
is received within an opening 38 in the insert 14. In this manner,
the screw 34 serves to locate and hold the insert 14 in the hollow
member 12. Preferably, when a screw 34 is used, the insert 14
includes an outer shell 28. The foam body 15 also may include an
opening 40 for receiving the screw 34.
[0030] Only one locating pin is shown in each of the embodiments.
It will be appreciated that one or more locating pins can be used
to locate the insert 14 in the hollow member 12.
[0031] In order to form a structural member 10, the insert 14 is
first inserted into the hollow member 12. The insert 14 may include
an outer shell 28. The insert 14 is positioned in the hollow member
12 such that the insert 14 and hollow member 12 define at least one
fluid passageway 22,22'. After the insert 14 is inserted into the
hollow member 12, fabrication of the hollow member 12 is completed,
such as by welding the components together. The hollow member 12
may then be subject to a fabrication process such as an E- coating
process. The E-coating fluids drain through the fluid passageway 22
and out of the hollow member 12 through holes 24. The structural
adhesive 26 is then applied in the fluid passageway 22. The
adhesive is cured by the application of heat and does not expand.
Once cured, the structural adhesive 26 locks the insert 14 to the
hollow member 12. By utilizing non-expandable structural adhesives
and a preformed insert 14, a higher stiffening reinforcement can be
achieved.
[0032] The present invention has been described to preferably be
used in connection with vehicles. It will be appreciated, however,
that the present invention may be used in any application requiring
the use of a structural member.
[0033] Presently, the preferred embodiments of the invention have
been described in an illustrative manner. It is to be understood
that the terminology used is intended to be in the nature of words
of description. Obviously many modifications and variations are
possible in light of the above teachings.
[0034] It is to be understood that, within the scope of the
appended claims, the invention may be practiced other than as
specifically described.
* * * * *