JP2011115787A - Gas generating system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a base assembly for a gas generating system. <P>SOLUTION: The base assembly includes a base and a retainer affixed to the base. In an alternative embodiment, the assembly includes an initiator molded to both the base and the retainer. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

Cross-reference to related applications This application claims the benefit of US Provisional Application No. 61 / 200,833, filed December 4, 2008.

  The present invention generally relates to a gas generation system that utilizes a pyrotechnic initiator to begin operation of the gas generation system. In one aspect, the present invention provides a base assembly for a gas generation system.

  The foundation assembly includes a foundation member and a retainer attached to the foundation member.

FIG. 1 is a cross-sectional view of a foundation assembly for a gas generation system housing according to a first embodiment of the present invention. 2A is a cross-sectional view of a base member incorporated in the embodiment shown in FIG. FIG. 2B is a plan view of the foundation member shown in FIG. 2A. FIG. 3A is a cross-sectional view of a retainer according to an embodiment of the present invention. FIG. 3B is a plan view of the retainer according to the embodiment of the present invention. FIG. 4A is a cross-sectional view of a foundation assembly according to a second embodiment of the present invention. FIG. 4B is a plan view of the foundation assembly shown in FIG. 4A. FIG. 4C is an enlarged view of the portion of the foundation assembly shown in FIG. 4A. FIG. 5 is a cross-sectional view of a gas generation system incorporating an embodiment of a foundation assembly according to an embodiment of the present invention. FIG. 6 is a schematic diagram of an exemplary vehicle occupant protection system incorporating a gas generation system with a foundation assembly according to an embodiment of the present invention.

  1-3B illustrate one embodiment of the base assembly 10 that forms part of the housing 34 of the gas generation system 200 according to one embodiment of the present invention. In the embodiment shown in FIGS. 1-3B, the base assembly 10 includes a base member 11 that forms part of a gas generation system housing 34 (see, eg, FIG. 5), and includes an initiator 20 and a booster material 56. An enclosure is provided that includes known gas generating system components such as booster cup 54, gas generant 60, filter 70, autoignition material (not shown) and other components as shown in FIG.

  The base member 11 includes an internal portion 11a having an orifice 12 for accommodating a known pyrotechnic initiator 20 therein. The inner wall 11b extends from the inner part 11a of the base member, and the outer wall 11c extends to the opposite inner wall 11b. The connecting part 11d connects the walls 11b and 11c. The walls 11b and 11c and the connecting portion 11d are connected to form an annular cavity 13 for receiving a portion of the retainer 18 therein. In the embodiment shown in FIGS. 1-3C, the walls 11b and 11c are arranged annularly, although different wall arrangements are possible depending on the needs of a particular application. A peripheral flange 11e extends from the outer wall 11c to facilitate attachment of the gas generation system to the vehicle or other device. The base member 11 may be stamped or otherwise formed from a metal, alloy or other suitable material.

  In the embodiment shown in FIGS. 1-3C, the base assembly 10 also includes a retainer 18 for placing and holding a gas generating system filter and gas generating material 60 (described below). In the embodiment shown in FIGS. 1-3, the retainer 18 has an annular base portion 18a, an annular outer wall 18b extending from the outer end of the base portion, and an annular inner wall 18c extending from the inner end of the base portion. Inner wall 18c, base portion 18a and outer wall 18b combine to define a cavity 18m for receiving gas generant 60 and the end of filter 70. The inner wall 18c further forms an internal cavity 18d. The inner cavity 18d has an annular first portion 18e having a first inner diameter from the base portion 18a and a second inner diameter adjacent to the first portion 18e and smaller than the first inner diameter. The neck is squeezed down to the annular second portion 18f in the direction away from the base portion 18a. The inner diameter of the first portion 18e is sized such that when the foundation inner portion 11a and the inner wall 11b are inserted into the cavity 18d, they fit snugly or contact with the foundation inner wall 11b. Is done. The retainer 11 may be formed from a metal, alloy or other suitable material by stamping, stretching, or other methods.

  In order to attach the retainer 18 to the base member 11, the base member inner portion 11a and the inner wall 11b are inserted into the cavity 18d, and the base member connecting portion 11d and the retainer base portion 18a are brought into contact or in close proximity to each other. Be placed. Thereafter, the foundation member and the retainer are welded along the foundation member connecting portion 11d and the retainer foundation portion 18a. Other methods of attaching the retainer to the foundation member are also contemplated.

  Reference is again made to FIGS. 4A-5. The gas generation system 10 further allows fluid communication between the initiator and the booster composition or other ignitable material when the gas generation system is activated to initiate combustion of the gas generation composition 30. Initiator or igniter 20 arranged to be included. In the embodiment shown in FIG. 5, the end of the initiator 20 extends from the solidified mold material 50 into a booster chamber formed by a booster cup 54 incorporated into the gas generation system.

  In a special embodiment 110 of the base assembly, the initiator is incorporated into the base assembly and molded into both the base member 11 and the retainer 18. Molding the initiator directly onto the base member forms an airtight seal between the base member and the initiator. One example of an initiator suitable for use in the gas generation system of the present invention is described in US Pat. No. 6,009,809, which is referenced and incorporated herein.

  As used herein, “molding” an initiator into a base assembly refers to injection, injection or other method of insertion into the housing after the initiator is in place and secured for molding operations. A flowable mold material, adhesive, or other material with the appropriate viscosity to fill the housing and fill the space between the initiator and the housing and between the initiator and the retainer Say. Thus, the base member and the retainer form part of the mold. The flowable material in contact with the base member, retainer and initiator is then cured or solidified to contain a portion of the initiator and secure the initiator to the base member and retainer. The solidified mold material can further form an airtight seal between the base member and the initiator.

  As seen in FIGS. 4A and 4C, when the inner portion 11a and the inner wall 11b are inserted into the cavity 18d, the base member inner portion 11a including the orifice 12 extends into the retainer cavity 18d. Further, when the initiator 20 is molded into the base assembly 10, a portion of the initiator passes from the first side 11z of the base member through the orifice 12 and the second side of the base member opposite the first side. Extends to side 11y. The orifice 12 is too small to allow the body portion 20a of the initiator 20 to pass from one side of the base member inner portion 11a to the other side of the base member inner portion in the direction indicated by arrow A (FIG. 4C). This helps to prevent the initiator 20 from being removed or protruded through the orifice 12.

  4C, when the initiator 20 is molded to the base member 11 and the retainer 18, the base member inner portion 11a protrudes into the molding material 50. As shown in FIG. Thus, the molding material that molds the initiator to the base member extends along the first side 11z of the base member and also extends along the second side 11y of the base member. Protrusion of the base member inner portion 11a into the molding material 50 causes the solidified molding material and the initiator 20 accommodated therein to the other elements of the base assembly 10 as shown in the figure. Helps to fix firmly in place.

  1-5 illustrate an embodiment of the base assembly 11 that is configured to house and secure a single initiator 20, as described below. Although described for a single initiator molded into a base member and retainer, the features and principles applicable to the embodiment shown in FIG. 1 further incorporate multiple initiators molded into the base assembly. The present invention can also be applied to the embodiment.

  In the illustrated embodiment, the mold material for securely attaching one or more initiators to the base assembly is subject to factors such as the desired manufacturing method, system operational requirements and other suitable factors. Can be selected based on. Materials such as polymers, injectable and injectable adhesives and potting compounds, and / or other suitable materials can be used. Molding parameters, such as pressure and temperature, are determined by iterative experiments based on factors such as the selected molding material and method, the type of structure on which the molding material is to be inserted, and other suitable factors. Can be done.

  Reference is made to FIGS. 4A and 4C. In another particular embodiment, a connector housing structure 30 that receives and secures an associated electrical connector (not shown) is molded into the structure that houses the initiator 20 to connect the initiator to the base member 11 and the retainer 18. To do. The connector housing structure 30 is used to connect the initiator 20 to a vehicle electrical device in a manner known in the art. If desired, a known electrical shorting clip structure (not shown) can also be molded into the molding material.

  FIG. 5 shows a base assembly embodiment 110 incorporated into the gas generation system 200. Please refer to FIG. The gas generation system 200 has a generally cylindrical housing 34 that includes a base assembly 110 and a cap 36 attached to the base assembly to form a system housing. The cap 36 has a plurality of openings 21 formed along it to allow fluid communication between the interior of the housing and the associated airbag (not shown). To prevent water vapor from entering the housing 34, the opening 21 can be covered with a foil (not shown) such as aluminum or stainless steel foil. The foil is often referred to as “burst foil” and is typically from 0.01 to about 0.20 mm thick. The foil is adhered to the inner surface of the housing, typically by use of an adhesive.

  The booster cup 54 encloses the exposed portion of the initiator 20 and defines a booster chamber 80 containing a known booster material 56 disposed within the housing 34, and during the activation of the inflator, booster material and gas generation. Allows fluid communication with the substance 60. Activation of the initiator 20 causes combustion of the booster material, thereby causing combustion of the gas generant material 60 in a manner known in the art.

  The gas generant material 60 is disposed outside the booster cup 54 and inside the retainer cavity 18m. The gas generant 60 can be any known gas generant composition useful in airbag applications including smokeless gas generant compositions, such as US Pat. Nos. 5,035,757, 5,872,329, Examples include, but are not limited to, the compositions and processes described in 6,074,502, 6,287,400, 6,306,232, and 6,475,312. These patents are referenced and made a part of this specification. Other suitable compositions are described in US patent application Ser. Nos. 10 / 407,300 and 60 / 369,775. These patents are referenced and made a part of this specification.

  Reference is again made to FIG. Within the known filter 70 is a plenum that is formed between the gas generant 60 and the outer wall of the housing 34.

  FIG. 6 illustrates one possible application of the foundation assembly embodiment described herein. Other gas generation systems, including other embodiments of the gas generation system 200 or foundation assembly described herein, are incorporated into the airbag system 800. The airbag system 800 includes a gas generation system that includes at least one airbag 902 and an embodiment of a base assembly coupled to the airbag and is in fluid communication with the interior of the airbag when the gas generation system is activated. Is connected to the airbag so as to allow. The airbag system 800 includes or is connected to a crash sensor 810. The crash sensor 810 includes a crash sensor algorithm (not shown) and signals activation of the airbag system 800 in the event of a crash, for example by activation of the initiator 20 (not shown in FIG. 6).

  The operation of the inflator is discussed with reference to FIG. Upon a collision, a signal from a collision sensor (not shown) is transmitted to the initiator 20, thereby activating the booster composition 56. Heat from the combustion of the booster composition 56 causes the gas generant 60 to burn. The expanded gas generated by the combustion of the gas generating substance 60 proceeds in the radial direction, passes through the filter 70, and is discharged from the housing 34 through the opening 21.

  Reference is again made to FIG. A gas generation system is an embodiment of a base assembly, or an airbag system including such a gas generation system includes a wider and more comprehensive vehicle occupant restraint system that includes additional elements such as a safety belt assembly 850 880 can be incorporated. Safety belt assembly 850 includes a safety belt housing 852 and a safety belt 825 extending from housing 852. A safety belt retractor mechanism 854 (eg, spring-loaded mechanism) can be coupled to the end portion of the belt. In addition, a safety belt pretensioner 856 can be coupled to the belt retractor mechanism 854 to trigger the retractor mechanism in the event of a collision. Typical seat belt retractor mechanisms that can be used with the safety belt 825 are US Pat. Nos. 5,743,480, 5,553,803, 5,667,161, 5,451,008, 4,558, 832 and 4,597,546. These patents are referenced and made a part of this specification. Examples of typical pretensioners with which a safety belt 825 can be combined are described in US Pat. Nos. 6,505,790 and 6,419,177. These patents are referenced and made a part of this specification.

  The safety belt assembly 850 may be a crash sensor algorithm that generates a belt pretensioner 856 activation signal upon activation of an initiator 24 (not shown in FIG. 6) or other initiator (not shown) incorporated into the pretensioner, for example. A collision sensor 858 (eg, an inertial sensor or accelerometer) can be included, or can be connected to it (not shown). US Pat. Nos. 6,505,790 and 6,419,177, referenced above and incorporated as part of this specification, provide examples of pretensioners that start in such a manner.

  It is understood that the various components described above are formed by known methods. Various elements can be formed, for example, from carbon steel, aluminum, metal alloys or various polymers by molding, stamping or other methods.

  It is understood that the foregoing description of embodiments of the invention is for illustrative purposes only. Various structural and operational features of the disclosed embodiments can be modified by those skilled in the art without departing from the scope of the present invention as set forth in the claims of this application. it can.

Claims (8)

A base assembly for a gas generation system, comprising: a base member; and a retainer attached to the base member. The foundation assembly of claim 1, further comprising an initiator molded to the foundation member and the retainer. 3. A portion of the initiator extends from a first side of the base member to a second side opposite the first side through an opening formed in the base member. Foundation assembly. 4. The size of the opening in the base member is adapted to prevent an initiator portion on the second side of the base member from moving to the first side of the base member. Foundation assembly. Molding material that molds the initiator to the base member extends along the first side of the base member and further along the second side of the base member opposite the first side. The foundation assembly of claim 2. A gas generation system comprising the foundation assembly of claim 1. A vehicle occupant protection system comprising a foundation assembly according to claim 1. The foundation assembly of claim 2, wherein the molding material that molds the initiator to the foundation member forms a connector housing structure for receiving and securing an associated electrical connector.

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