U.S. patent application number 09/747326 was filed with the patent office on 2002-06-27 for modular air bag housing.
Invention is credited to Thomas, David James, Winters, Mark Thomas.
Application Number | 20020079674 09/747326 |
Document ID | / |
Family ID | 25004609 |
Filed Date | 2002-06-27 |
United States Patent
Application |
20020079674 |
Kind Code |
A1 |
Thomas, David James ; et
al. |
June 27, 2002 |
MODULAR AIR BAG HOUSING
Abstract
A containment structure for housing an inflatable air bag
cushion and inflator. Extrusion processes are used to form the
portion of the containment structure which houses the inflatable
air bag cushion while non-extrusion processes are used to form the
portion of the containment structure which houses the inflator in
fluid communication with the inflatable cushion. The portion of the
containment structure which houses the inflatable air bag cushion
is preferably formed from a lightweight, readily deformable
material and will preferably be formed from extruded aluminum or
plastic. The portion of the containment structure housing the
inflator is preferably formed by a deep drawing or molding process
so as to include an integral chamber sized for the acceptance and
storage of the inflator therein.
Inventors: |
Thomas, David James; (Villa
Hills, KY) ; Winters, Mark Thomas; (Troy,
OH) |
Correspondence
Address: |
KATHRYN A. MARRA
DELPHI TECHNOLOGIES, INC.
Legal Staff Mail Code: 480-414-420
P. O. Box 5052
Troy
MI
48007-5052
US
|
Family ID: |
25004609 |
Appl. No.: |
09/747326 |
Filed: |
December 21, 2000 |
Current U.S.
Class: |
280/728.2 ;
280/741 |
Current CPC
Class: |
B60R 21/2171
20130101 |
Class at
Publication: |
280/728.2 ;
280/741 |
International
Class: |
B60R 021/16 |
Claims
1. An air bag containment structure comprising: a cushion housing
structure formed by the forced extrusion of plastically deformable
material wherein the cushion housing structure is of a depressed
channel configuration comprising an open-ended recess disposed
between opposing side wall elements such that a folded inflatable
air bag cushion may be stored within the recess between the
opposing side wall elements; end caps non-integral to the cushion
housing structure disposed across the ends of the open-ended
recess; and an inflator housing connected to the cushion housing
structure, the inflator housing including an integral chamber of
depressed profile for storage of a gas emitting inflator such that
the gas emitting inflator is in fluid communication with the
inflatable air bag cushion, the integral chamber being of a
substantially unitary construction formed by non-extrusion
processes.
2. The invention according to claim 1, wherein the cushion housing
structure is formed from aluminum.
3. The invention according to claim 2, wherein the inflator housing
is formed from a material selected from the group consisting of
aluminum and steel.
4. The invention according to claim 3, wherein the integral chamber
of depressed profile within the inflator housing is formed by deep
drawing.
5. The invention according to claim 1, wherein the cushion housing
structure is formed from aluminum and the inflator housing
comprises injection molded plastic.
6. The invention according to claim 1, wherein the cushion housing
structure is formed from aluminum and the inflator housing
comprises die cast metal.
7. The invention according to claim 1, wherein the end caps
comprise protruding flanges formed integrally with the inflator
housing and extending outwardly from the inflator housing, which
protruding flanges slide over the ends of the cushion housing
structure to substantially cover the ends of the open-ended
recess.
8. The invention according to claim 1, wherein the inflator housing
is formed integral with the cushion housing structure thereby
comprising an article of unitary construction.
9. The invention according to claim 8, wherein the cushion housing
structure includes a bottom wall structure extending between the
opposing side wall elements which bottom wall structure undergoes a
deep drawing operation to form the integral chamber of depressed
profile within the bottom wall structure.
10. The invention according to claim 9, wherein the cushion housing
structure is formed from aluminum.
11. A method for forming an air bag containment structure
comprising the steps of: forming a cushion housing structure of
open-ended construction by the forced extrusion of a metallic
material wherein the cushion housing structure is of a depressed
channel configuration comprising an open-ended recess disposed
between opposing side wall elements such that a folded inflatable
air bag cushion may be stored within the recess between the
opposing side wall elements; forming an inflator housing structure
of a metallic material for connection to the cushion housing
structure, such that the inflator housing structure includes an
integral chamber of depressed profile formed by deep drawing for
storage of a gas emitting inflator in fluid communication with the
inflatable air bag cushion; attaching the inflator housing
structure to the cushion housing structure; and applying end caps
across the ends of the open-ended recess.
12. The method according to claim 11, wherein said metallic
material is characterized by a face centered cubic crystal
structure.
13. The method according to claim 12, wherein said metallic
material is aluminum.
14. A method for forming an air bag containment structure
comprising the steps of: forming a cushion housing structure of
open-ended construction by the forced extrusion of a metallic
material wherein the cushion housing structure is of a depressed
channel configuration comprising an open-ended recess defined by a
substantially flat bottom wall disposed between opposing side wall
elements such that a folded inflatable air bag cushion may be
stored within the recess in overlying relation to the bottom wall
and between the opposing side wall elements; forming a chamber of
depressed profile within the bottom wall by deep drawing for
storage of a gas emitting inflator in fluid communication with the
inflatable air bag cushion; and applying end caps across the ends
of the open ended recess.
15. The invention according to claim 14, wherein the opposing side
wall elements include integral rod receiving channels for
acceptance of air bag retaining rods.
16. The invention according to claim 14, wherein said metallic
material is characterized by a face centered cubic crystal
structure.
17. The invention according to claim 14, wherein said metallic
material is aluminum.
Description
TECHNICAL FIELD
[0001] The present invention relates to an air bag housing
structure, and more particularly to an air bag housing structure
incorporating an extruded cushion housing for storage of an
inflatable air bag cushion therein.
BACKGROUND OF THE INVENTION
[0002] It is well known in the prior art to provide an air bag
module which includes an inflatable air bag cushion for protection
of a vehicle occupant in the event of a collision. The air bag
module typically includes an inflator for discharging an inflation
medium to inflate the air bag cushion upon the occurrence of a
predetermined level of vehicle decelaration or other measurable
condition.
[0003] The inflator and the air bag cushion are typically stored
within a housing structure of substantially unitary construction.
Such a housing is generally defined by opposing side walls which
are joined by a bottom wall and opposing end walls to define a deep
trough-like structure which is open at the top. One end wall
typically includes an enlarged opening for receiving the inflator
therethrough during the assembly process. The inflator is typically
of a substantially cylindrical configuration including a plurality
of gas discharge openings disposed about one end. The air bag
cushion is typically stored in a folded condition atop the inflator
within the depression existing between the walls of the
housing.
[0004] Upon activation of the inflator, the air bag cushion is
filled with a predetermined quantity of the inflation medium
discharged by the inflator thereby causing the air bag cushion to
deploy outwardly through the top opening formed by the side walls
and end walls of the housing structure. The air bag cushion
typically includes a means of attachment to the housing such as a
retaining rod attached to the rim of the housing so as to hold the
air bag cushion in place relative to the housing during the
inflation process.
[0005] Initial prior art housings were formed from stamped steel
which yields an enclosure of high strength. However, such a
structure has the detriment of adding a relatively substantial mass
to the vehicle structure and may require corrosion resistance
treatment prior to installation.
[0006] In order to overcome the deficiencies of stamped steel
housings, it has been proposed to utilize aluminum housings formed
by plastic deformation through a deep drawing process so as to
yield the desired walled construction. While such an aluminum
housing formed entirely by a deep drawing process offers the
potential benefits of low weight in combination with excellent
corrosion resistance, the deep drawing of aluminum has inherent
depth restrictions due to the naturally occurring thinning at the
lower portions of the formed structure as the depth of the draw is
increased.
[0007] It has also been proposed to utilize an aluminum extrusion
process to form an open ended structure for housing both the air
bag cushion and inflator and to thereafter attach steel or
magnesium end caps to close off both ends of the housing and form
the desired enclosure. Such an extruded housing of aluminum offers
the benefits of low weight and controlled uniform wall thickness.
However, since the structure formed by such an extrusion process
will be substantially uniform along its entire length, it is
difficult to accommodate a number of variations of air bag cushions
and inflators within a housing formed exclusively by such an
extrusion process with subsequently applied end caps. Specifically,
if the inflator is shorter than the required cushion containment
portion of the housing, the overall structure must undergo
substantial post processing to accommodate the inflator or a
relatively complex end cap design must be utilized.
[0008] It has also been proposed to utilize housings formed
entirely from injection molded plastic. However, due to the wide
variety of air bag cushions and inflators which are utilized, the
cost and lead time for the required injection molding equipment may
be prohibitive.
[0009] Finally, it has been proposed to form housings entirely from
relatively lightweight die cast materials such as magnesium.
However, the cost of such materials may be prohibitive.
SUMMARY OF THE INVENTION
[0010] This invention provides an advantageous containment
structure for housing an inflatable air bag cushion and inflator
which utilizes extrusion processes to form the portion of the
containment structure which houses the inflatable cushion while
utilizing non extrusion processes to form the portion of the
containment structure which houses the inflator in fluid
communication with the inflatable cushion. The portion of the
containment structure which houses the inflatable air bag cushion
is preferably formed from a lightweight, readily deformable
material and will preferably be formed from extruded aluminum or
plastic. The portion of the containment structure housing the
inflator is preferably formed by a deep drawing or molding process
so as to include an integral chamber sized for the acceptance and
storage of the inflator therein. The portions of the containment
structure housing the inflatable air bag cushion and the inflator
may either be formed as separate elements or may be part of a
unitary construction.
[0011] Advantageously, the containment structure, according to the
present invention, permits the substantial utilization of aluminum
or other low cost, lightweight, extrudable materials. The present
invention provides the added advantage of utilizing a combination
of extrusion and non-extrusion formation techniques such that the
portion of the structure which houses the inflatable air bag
cushion may be formed substantially by extrusion processes thereby
gaining the benefit of highly efficient extrusion practices.
Non-extrusion formation techniques such as deep drawing may be used
in the formation of the three dimensional chamber for housing the
inflator. It has been found that the combination of extrusion and
non-extrusion formation practices for forming different portions of
the same containment structure provides substantial synergistic
benefits by permitting the utilization of lightweight materials
throughout the containment structure and by permitting substantial
versatility in the configuration of the chamber housing the
inflator.
[0012] According to one potentially preferred aspect of the present
invention, these advantages and features are accomplished by
providing an air bag containment structure which includes a cushion
housing formed from aluminum or plastic by the forced extrusion of
such material. The cushion housing is of a depressed open-ended
channel configuration having a recess between opposing side wall
elements. The recess formed between the side wall element is
dimensioned to accept a folded inflatable air bag cushion
therewithin. End caps made of a material compatible with the
material forming the cushion housing are attached across the open
ends of the extruded cushion housing to form a three dimensional
walled enclosure within which the air bag cushion is housed.
[0013] An inflator housing formed of a material compatible with the
cushion housing and including an integral chamber of depressed
profile for storage of a gas emitting inflator is connected to the
cushion housing such that the gas emitting inflator is in fluid
communication with the inflatable air bag cushion. The chamber of
depressed profile for storage of the gas emitting inflator is
formed by non extrusion formation techniques, and is preferably
formed from deep drawn aluminum. The portion of the containment
structure which houses the inflator may be integral with the
portion housing the inflatable air bag cushion. In the event that
the portion of the containment structure housing the inflator is
discrete from the portion housing the inflatable air bag cushion,
the inflator housing portion may include outwardly extending flange
structures which cooperatively engage the open ends of the cushion
housing thereby serving as end caps for the cushion housing. The
air bag containment structure may be formed entirely from aluminum
if desired.
[0014] Thus, it will be appreciated that the present invention
provides a substantial degree of versatility in the manufacturing
process thereby permitting the more efficient utilization of
materials of construction and formation techniques within a wider
variety of structural configurations. The present invention thereby
yields a highly efficient, cost effective and lightweight
containment structure for use in housing an inflatable air bag
cushion and inflation element.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] The principles of the present invention are set forth in the
following detailed description through reference to the
accompanying drawings which are incorporated in and constitute a
part of this specification in which:
[0016] FIG. 1 is a cut-away end view of an air bag containment
structure according to the present invention including an
inflatable air bag cushion and gas emitting inflator disposed
therein;
[0017] FIG. 2 is an exploded perspective view of the components of
an air bag containment structure according to the present
invention;
[0018] FIG. 3 is a perspective view of an inflator housing
including integral end cap elements for use in an air bag
containment structure according to the present invention;
[0019] FIG. 4 is a cut-away side view of an air bag containment
structure according to the present invention;
[0020] FIG. 5 is an exploded perspective view of an air bag
containment structure according to the present invention wherein
the inflator housing is formed integrally with the cushion
housing;
[0021] FIG. 6A is an intermediate cross-sectional assembly view of
the cushion housing illustrated in FIG. 5 before introduction of
the inflator housing chamber; and
[0022] FIG. 6B is a view similar to FIG. 6A subsequent to the
introduction of the inflator housing chamber.
[0023] While the invention has been illustrated and generally
described above, and will hereafter be described in detail in
connection with certain potentially preferred embodiments, it is to
be appreciated that the foregoing general description as well as
the particularly illustrated and described embodiments as may be
set forth herein are intended to be exemplary and explanatory only.
Accordingly, there is no intention to limit the invention to such
particularly illustrated and described embodiments. On the
contrary, it is intended that the present invention shall extend to
all alternatives, modifications, and equivalents as may embody the
broad aspects and principles of the invention within the full
spirit and scope thereof.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0024] Referring to FIGS. 1, 2, and 4 an air bag module 10 such as
may be mounted in a vehicle (not shown) for protection of a vehicle
occupant is provided. As illustrated, the air bag module 10 houses
an inflatable air bag cushion 12. Such an air bag cushion 12 is
typically formed of a substantially pliable material such as a
coated or uncoated woven fabric which may be folded for storage
within an air bag housing structure 20 as will be described further
hereinafter.
[0025] The air bag module 10 further includes an inflator housing
structure 30 for connection to the air bag housing structure 20. As
will be discussed further hereinafter, the inflator housing
structure 30 may be formed either separately from or integrally
with the air bag housing structure 20. In either configuration, the
inflator housing structure 30 preferably includes a walled chamber
32 of depressed profile for housing a gas emitting inflator 34. As
will be appreciated, the end walls of the chamber 32 preferably
include openings for the insertion of the inflator 34 therein
during the assembly process in a manner well known to those of
skill in the art so as to achieve an assembled construction as
illustrated in FIG. 4.
[0026] The inflator 34 may be of any conventional construction for
generating inflator gas to inflate the air bag cushion 12 although
a generally cylindrical configuration may be preferred for ease of
insertion within the walled chamber 32. As best seen in FIG. 4,
such a cylindrical inflator 34 preferably includes a plurality of
discharge ports 36 which are spaced around the neck portion of the
inflator 34. Such an inflator also preferably includes an outwardly
extending mounting stud 37 for passage through a corresponding
aperture in one end wall of the chamber 32 for securement by a
mounting nut 38 as shown. According to the potentially preferred
embodiment of the present invention, the length of the chamber 32
will be substantially equivalent to the length of the body of the
inflator 34 thereby permitting the inflator to be supported along
its length.
[0027] The inflatable air bag cushion 12 may be secured to a
retainer ring 40 (FIG. 1) from which extend a plurality of pressed
studs 41. These pressed studs 41 may pass through corresponding
apertures 21, 31 within the air bag housing structure 20 and
inflator housing structure 30 respectively as shown. The
orientation of these structural components may be maintained by
mounting nuts 42 attached to the pressed studs 41 as shown.
[0028] According to the illustrated and potentially preferred
embodiment of the present invention, the air bag housing structure
20 is of a recessed channel configuration having two opposing side
walls 22, 23 joined by a bottom wall 24. As best seen in FIG. 2, a
gas communication slot 25 is preferably disposed at the interior of
the bottom wall 24 for transmission of inflating gas from the
inflator 34 into the air bag cushion 12. End caps 50 are preferably
attached to the open ends of the air bag housing structure 20
thereby providing a three dimensional walled enclosure with an open
top in which the air bag cushion 12 may reside.
[0029] In accordance with the present invention, the recessed
configuration of the air bag housing structure 20 is preferably
formed by a forced extrusion process. Such a process yields a part
of substantially controlled cross-sectional configuration along its
length. Moreover, the thickness of the walls of a part formed by
forced extrusion may be controlled in all regions of the part. Such
close control permits the production of parts of highly
reproducible quality.
[0030] Forced extrusion is carried out by passing an article
through a die of defined configuration thereby forcing the article
to substantially conform to that configuration. In order to achieve
such conformance of configuration, the force applied to the article
undergoing extrusion must exceed the critical resolved shear stress
of the material forming the article such that substantially
permanent plastic deformation of the material may take place.
However, the applied forces to which the material is subjected must
not be so great as to result in undue embrittlement and/or fracture
of the material. One material which is believed to be particularly
suitable to undergo such extrusion processing is aluminum. Other
materials as may be suitable for extrusion processing include, by
way of example only, and not limitation, other face centered cubic
metals as well as plastics.
[0031] As will be appreciated, the extrusion formation process
yields an air bag housing structure 20 of a substantially
open-ended construction. Thus, the application of end caps 50 may
be desirable in order to substantially contain the inflatable air
bag cushion 12 and to define a path of travel for the air bag
cushion 12 as it is inflated. The end caps 50 may be formed from
any material which is compatible with the material from which the
air bag housing structure 20 is formed and will preferably be
substantially flat pieces of plastic although other materials
including aluminum and steel are also contemplated.
[0032] As shown, the inflator housing 30 preferably includes a base
plate 33 from which the walled chamber 32 distends. The upper
surface of the base plate 33 may be applied to the lower surface of
the bottom wall 24 such that there is substantial alignment between
the corresponding aperture 21, 31, to permit securement by the
pressed studs 41 and mounting nuts 42 in the manner previously
described. In such an arrangement, the opening to the walled
chamber 32 within the inflator housing 30 will preferably be
aligned with the gas communication slot 25 thereby providing fluid
communication between the inflator 34 and the air bag cushion
12.
[0033] While the lengths of the air bag housing structure 20 and
the inflator housing structure 30 may be substantially equivalent,
such a relation is not necessary. Thus, the length of the inflator
housing structure 30 may be selected based on the dimensions of the
inflator 34 to be housed therein independently of the air bag
housing structure 20, provided that suitable attachment and fluid
communication are maintained.
[0034] Due to the substantially closed configuration of the end
walls of the chamber 32, it is contemplated that the inflating
housing structure is preferably formed by a suitable non-extrusion
process. According to the potentially preferred practice, the
desired configuration of the inflator housing structure 30 is
achieved by a deep drawing procedure wherein the walled chamber 32
is formed by the application of force across the base plate 33 to
conform to a final desired geometry. In order to form the walled
chamber 32 by such a deep drawing operation, it is desirable that
the material from which the inflator housing structure 30 is formed
is of a relatively easily deformable character. However, material
must also be structurally suitable for the containment of the gas
emitting inflator 34 during activation.
[0035] According to the potentially preferred practice, the
inflator housing structure will be formed from a metallic material
such as aluminum due to its lightweight character. However, it is
also contemplated that other materials such as steel and the like
may also be utilized. While a deep drawn metallic material may be
potentially preferred in the construction of the inflator housing
structure 30, it is also contemplated that injection molding or die
casting techniques of materials such as plastic or magnesium
respectively can likewise be utilized. Such materials offer the
advantages of light weight and avoid the use of deep drawing or
other mechanical deformation processes.
[0036] It is to be understood that the present invention is
susceptible to a wide variety of alternatives and modifications. By
way of example only, in FIG. 3 there is illustrated an alternative
embodiment of the inflator housing structure wherein elements of
like character as illustrated in FIG. 2 are designated by like
reference numerals with a prime. As shown, in the alternative
embodiment of FIG. 3, the end caps for the air bag housing
structure are formed integrally with the base plate 33 of the
inflator housing structure 30. As will be appreciated, such a
configuration may be achieved by bending the lateral sides of the
base plate 33 upwardly to a desired degree. In the alternative,
such a configuration may be achieved by injection molding or die
casting operations.
[0037] During assembly, the integral end caps 50' slide over the
open ends of the air bag housing structure 20 thereby providing a
walled containment structure for the air bag cushion as may be
desired. If desired, the integral end caps 50' may be provided with
apertures 51 for introduction of mounting screws or other
attachment devices as may be desired to promote structural
stability.
[0038] In FIG. 5, there is illustrated yet another embodiment of
the present invention wherein elements corresponding to those
illustrated in FIG. 2 are designated by like reference numerals
with a double prime. As shown, in the embodiment of the present
invention illustrated in FIG. 5, the walled chamber 32" for housing
the inflator is formed integrally with the air bag housing
structure 20". End caps 50" are applied at the ends of the air bag
housing structure 20" to define a recess enclosed on four sides for
containment of an inflatable air bag cushion. As will be
appreciated, due to the integral relation between the air bag
housing 20" and the walled chamber 32" separate attachment
mechanisms are not required to secure such elements to one another,
thereby substantially eliminating the need for the pressed studs 41
as may be utilized in the non-integral embodiments as previously
illustrated and described. In the integral embodiment of the
present invention it is contemplated that the air bag cushion will
preferably be held within the air bag housing structure 20" by rod
receiving channel elements 65" as will be well known to those of
skill in the art. It is contemplated that such rod receiving
channel elements 65" may be formed integrally with the side walls
22", 23" during a forced extrusion operation.
[0039] According to a potentially preferred practice, the air bag
housing structure 20" may be formed integrally with the chamber 32"
by first extruding the air bag housing structure 20" including
opposing side walls 22", 23" with integral rod receiving channel
elements 65", and a substantially flat bottom wall 24" as
illustrated in FIG. 6A. Thereafter, a deep drawing process may be
applied across the surface of the bottom wall 24" so as to form the
chamber 32" in a distending configuration. As will be appreciated,
the material from which such a unitary structure is formed must be
suitable for both extrusion and deep drawing processes. A metallic
material such as aluminum characterized by a face centered cubic
crystal structure may be preferred.
[0040] In view of the foregoing detailed description, it will be
understood that the present invention provides a highly efficient
and versatile structure for the containment of an inflatable air
bag and gas emitting inflator wherein the housing for the air bag
is formed as an open ended structure though use of extrusion
formation processes and the housing for the inflator is formed to
include an integral chamber of substantially enclosed construction
including dimensionally stable end wall segments for the receipt
and support of the inflator therein. Such a construction permits
the inflator housing to be designed for the specific inflator to be
used and to be subsequently mated to cushion housing designed for a
particular cushion. Such a configuration also reduces complexity by
eliminating the need to apply end caps to the chamber housing the
inflator. In addition, the present invention permits the efficient
utilization of aluminum and other lightweight materials while
maintaining strength requirements.
[0041] While the present invention has been illustrated and
described in relation to several particularly preferred embodiments
and constructions, it is to be understood that such embodiments and
constructions are illustrative only and the present invention is in
no event to be limited thereto. Rather, it is contemplated that
modifications and variations to the present invention will no doubt
occur to those of skill in the art upon reading the above
description and/or through practice of the invention. It is
therefore contemplated and intended that the present invention
shall extend to all such modifications and variations which
incorporate the broad aspects of the present invention within the
full spirit and scope of the following claims and all equivalents
thereto.
* * * * *