Gas generator

Abstract

To provide a gas generator capable of suppressing gas from being discharged to the outside of a housing without passing a filter while suppressing enlargement of the filter.SOLUTION: A gas generator 100 includes: a housing having a bottom plate part 11, a top plate part 21, a peripheral wall part 12 and a peripheral wall part 22; a support member 91 having a support part 91c projecting to the inside in the radial direction from an outer wall part 91b at the bottom plate part 11 side from an edge face at the top plate part 21 side of the outer wall part 91b connected to an inner end part of a mounting part 91a mounted on the tip surface of the peripheral wall part 12 and projecting to the bottom plate part 11 side than the mounting part 91a, and annularly disposed along the circumferential direction of the housing; a filter 90 held by the top plate part 21 and the support part 91c, and annularly disposed along the circumferential direction; and an igniter 40 for igniting and burning a gas generating agent 61 generating gas by burning. A contact part between the peripheral wall part 12, and the mounting part 91a and the outer wall part 91b is welded, and the outer wall part 91b is welded to the inner peripheral surface of the peripheral wall part 12.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a gas generator incorporated in an occupant protection device for protecting an occupant in the event of a vehicle collision, and more particularly to a gas generator incorporated in an airbag device mounted on an automobile or the like. [Background technology]

[0002] Airbag devices, which are passenger protection devices, have become widespread from the viewpoint of protecting passengers in automobiles, etc. Airbag devices are installed to protect passengers from impacts that occur during a vehicle collision, and the airbag instantly inflates and deploys during a vehicle collision, thereby acting as a cushion to support the passenger's body.

[0003] Gas generators have a variety of structures, but a gas generator that is particularly suitable for use in a driver's side airbag device, a passenger's side airbag device, etc. is a short, approximately cylindrical disk-type gas generator with a relatively large outer diameter.

[0004] A disk-type gas generator has a short, approximately cylindrical housing with both axial ends closed, a plurality of gas outlets provided in the peripheral wall of the housing, a transfer charge contained inside the housing so as to face an igniter assembled to the housing, a gas generating agent filled inside the housing so as to surround the transfer charge, and a filter contained inside the housing so as to further surround the gas generating agent.

[0005] For example, Patent Document 1 discloses a gas generator comprising a housing, a combustion chamber filled with a gas generating agent and provided within the housing, a gas outlet for discharging combustion gas generated by combustion of the gas generating agent to the outside, and a filter unit for filtering the combustion gas. A dividing wall is disposed between an upper shell and a lower shell of the housing, and a filter unit is mounted on the dividing wall. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Publication No. 2020-114698 Summary of the Invention [Problem to be solved by the invention]

[0007] In a gas generator, a filter has the functions of cooling and collecting residue. However, for example, if the filter is made by winding and sintering metal wire, increasing the amount of wire used and making the filter larger in order to improve the filtering function would result in the gas generator no longer being small and lightweight. Therefore, it is desirable to prevent the filter from becoming too large while still allowing gas to pass through the filter reliably.

[0008] The present invention has been made in view of the above circumstances, and has an object to provide a gas generator in which the size of the filter is prevented from increasing and gas passes through the filter reliably. [Means for solving the problem]

[0009] (1) A gas generator of the present invention is a cylindrical housing having a bottom plate, a top plate opposite the bottom plate, a first peripheral wall extending from the outer peripheral edge of the bottom plate toward the top plate, and a second peripheral wall extending from the outer peripheral edge of the top plate toward the bottom plate and having a plurality of gas outlets disposed therein; a mounting portion placed on a tip end surface of the first peripheral wall, an outer wall connected to an inner end of the mounting portion in the radial direction of the housing and protruding toward the bottom plate beyond the mounting portion, and a radial extension of the housing from the outer wall portion to the bottom plate beyond the end face of the outer wall on the top plate side. The housing is characterized in that it comprises a support member having a support portion protruding inward and arranged in a ring shape along the circumferential direction of the housing, a filter sandwiched between the top plate portion and the support portion and arranged in a ring shape along the circumferential direction, a gas generating agent that is contained in a space surrounded by the bottom plate portion, the top plate portion, the first peripheral wall portion, the support member, and the filter and generates gas by combustion, and an igniter that ignites and burns the gas generating agent, and wherein the contact portion between the first peripheral wall portion and at least one of the mounting portion and the outer wall portion, or the contact portion between the second peripheral wall portion and the mounting portion, is welded.

[0010] (2) In the gas generator of (1) above, it is preferable that the support portion protrudes radially inward beyond the filter, the support member has an inner wall portion protruding from the support portion toward the top plate portion, inside the filter in the radial direction, and the filter is sandwiched between the outer wall portion and the inner wall portion.

[0011] (3) In the gas generator of (2) above, it is preferable that an outer surface of the inner wall portion in the radial direction is inclined so as to be positioned radially outward as it approaches the bottom plate portion.

[0012] (4) In the gas generator of (1) above, it is preferable that the second peripheral wall portion is spaced apart from the first peripheral wall portion, the support member is arranged to close the gap between the first peripheral wall portion and the second peripheral wall portion, and is welded to the first peripheral wall portion and the second peripheral wall portion.

[0013] (5) In the gas generator of (1) above, it is preferable that the second peripheral wall portion and the outer peripheral surface of the first peripheral wall portion in the radial direction are welded closer to the bottom plate portion than the support member, and that a heat insulating member is provided that is supported by the support member so as to sandwich the first peripheral wall portion and face the welded portion between the second peripheral wall portion and the outer peripheral surface of the first peripheral wall portion.

[0014] (6) In the gas generator described above in (5), the heat insulating member is preferably provided spaced apart from the first circumferential wall portion in the radial direction. [Effects of the Invention]

[0015] According to the present invention, it is possible to provide a gas generator in which the size of the filter is suppressed and gas reliably passes through the filter. [Brief explanation of the drawings]

[0016] [Figure 1] 1 is a schematic cross-sectional view showing a disk-type gas generator according to a first embodiment of the present invention. [Figure 2] FIG. 4 is a schematic cross-sectional view showing a disk-shaped gas generator according to a second embodiment of the present invention. [Figure 3] FIG. 10 is a schematic cross-sectional view showing a disk-shaped gas generator according to a third embodiment of the present invention. [Figure 4] FIG. 10 is a schematic cross-sectional view showing a disk-shaped gas generator according to a fourth embodiment of the present invention. [Figure 5] FIG. 10 is a schematic cross-sectional view showing a disk-shaped gas generator according to a fifth embodiment of the present invention. [Figure 6] FIG. 10 is a schematic cross-sectional view showing a disk-shaped gas generator according to a sixth embodiment of the present invention. [Figure 7] FIG. 12 is a schematic cross-sectional view showing a disk-shaped gas generator according to a seventh embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0017] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the embodiments shown below, the present invention is applied to a disk-type gas generator that is suitably incorporated into an airbag device mounted on the steering wheel of an automobile or the like.

[0018] First Embodiment Fig. 1 is a schematic cross-sectional view showing a disk-shaped gas generator 100 according to a first embodiment of the present invention. First, with reference to Fig. 1, disk-shaped gas generator 100 according to the present embodiment will be described.

[0019] As shown in Fig. 1, disk-shaped gas generator 100 includes a housing, holding portion 30, igniter 40, cup-shaped member 50, lower support member 70, upper support member 80, cushion material 85, filter 90, and support member 91. An accommodating space provided inside the housing accommodates internal components such as a part of holding portion 30, igniter 40, cup-shaped member 50, transfer charge 59, gas generant 61, lower support member 70, upper support member 80, cushion material 85, filter 90, and support member 91. A combustion chamber 60 is located in the accommodating space provided inside the housing, and this combustion chamber 60 mainly accommodates gas generant 61, one of the internal components described above. Here, in one variation, lower support member 70 may be omitted.

[0020] The housing is a short, generally cylindrical body with one axial end and the other axial end closed. The housing includes a lower shell 10 and an upper shell 20. The lower shell 10 and the upper shell 20 are each formed as a press-molded product, for example, by pressing a rolled metal plate-like member. The metal plate-like members constituting the lower shell 10 and the upper shell 20 are made of metal plates made of stainless steel, iron steel, aluminum alloy, stainless alloy, or the like, and preferably so-called high-tensile steel plates that will not break or otherwise be damaged even when a tensile stress of 440 MPa or more and 780 MPa or less is applied.

[0021] The lower shell 10 and the upper shell 20 are each formed in a generally cylindrical shape with a bottom, and are assembled and joined together with their open surfaces facing each other to form a housing. The lower shell 10 has a bottom plate 11 and a peripheral wall 12, and the upper shell 20 has a top plate 21, a peripheral wall 22, and a flange 25. The peripheral wall 12 is an example of a first peripheral wall extending from the outer peripheral edge of the bottom plate 11 toward the upper shell 20 (top plate 21 side). The peripheral wall 22 is an example of a second peripheral wall extending from the outer peripheral edge of the top plate 21 toward the lower shell 10 (bottom plate 11 side).

[0022] The upper end of the peripheral wall 12 of the lower shell 10 is inserted into the lower end of the peripheral wall 22 of the upper shell 20 and press-fitted. Furthermore, the peripheral wall 12 of the lower shell 10 and the peripheral wall 22 of the upper shell 20 are joined at or near their abutment, thereby fixing the lower shell 10 and the upper shell 20 together. Here, electron beam welding, laser welding, friction welding, or the like can be suitably used to join the lower shell 10 and the upper shell 20. In this embodiment, the lower shell 10 and the upper shell 20 are YAG welded together, and a weld 92 between the lower shell 10 and the upper shell 20 is formed.

[0023] As a result, the portion of the peripheral wall of the housing closer to the bottom plate 11 is formed by the peripheral wall 12 of the lower shell 10, and the portion of the peripheral wall of the housing closer to the top plate 21 is formed by the peripheral wall 22 of the upper shell 20. One end and the other end in the axial direction of the housing are closed by the bottom plate 11 of the lower shell 10 and the top plate 21 of the upper shell 20, respectively.

[0024] The bottom plate portion 11 of the lower shell 10 has a protruding tubular portion 13, a recessed portion 14, and an opening 15. The protruding tubular portion 13 protruding toward the top plate portion 21 is provided in the center of the bottom plate portion 11 of the lower shell 10, thereby forming a recessed portion 14 in the center of the bottom plate portion 11 of the lower shell 10. The protruding tubular portion 13 is a portion where the igniter 40 is fixed via the holding portion 30, and the recessed portion 14 is a portion that provides space for providing the female connector portion 34 in the holding portion 30. The recessed portion 14 is recessed toward the inside of the housing on the outer surface of the housing. Specifically, the recessed portion 14 is recessed toward the top plate portion 21 on the outer surface of the bottom plate portion 11.

[0025] Protruding tube portion 13 is formed in a generally cylindrical shape with a bottom, and an opening 15 having a point-asymmetric shape (for example, a D-shape, a barrel shape, an oval shape, etc.) in a plan view is provided at its axial end portion located on the top plate portion 21 side. Opening 15 penetrates bottom plate portion 11 in the axial direction. That is, opening 15 is formed at the bottom of recessed portion 14, penetrates bottom plate portion 11 in the direction in which recessed portion 14 is recessed, and communicates between the inside and outside of the housing. Opening 15 is a portion through which a pair of terminal pins 42 of igniter 40 are inserted.

[0026] The igniter 40 is for generating a flame and includes an ignition portion 41 and a pair of terminal pins 42. The igniter 40 ignites and burns the gas generating agent 61. The ignition portion 41 is disposed inside the housing and is ignited by the flow of electric current. The ignition portion 41 includes an ignition charge that ignites and burns to generate a flame when activated, and a resistor for igniting the ignition charge. The pair of terminal pins 42 are a pair of terminal pins for passing electric current through the ignition portion 41. The pair of terminal pins 42 are connected to the ignition portion 41 to ignite the ignition charge. The pair of terminal pins 42 extend to the outside of the housing through the opening 15.

[0027] More specifically, the ignition unit 41 comprises a cup-shaped squib cup and a plug that closes the open end of the squib cup and through which a pair of terminal pins 42 are inserted and held; a resistor (bridge wire) is attached to connect the tips of the pair of terminal pins 42 inserted into the squib cup; and an ignition charge is loaded into the squib cup so as to surround or be close to the resistor.

[0028] Here, nichrome wire is generally used as the resistor, and ZPP (zirconium potassium perchlorate), ZWPP (zirconium tungsten potassium perchlorate), lead tricinate, etc. are generally used as the ignition charge. The squib cup and plug mentioned above are generally made of metal or plastic.

[0029] When a collision is detected, a predetermined amount of current flows through the resistor via the terminal pin 42. This current flow generates Joule heat in the resistor, causing the ignition charge to begin burning. The high-temperature flame generated by the combustion ruptures the squib cup containing the ignition charge. The time from when the current flows through the resistor to when the igniter 40 is activated is generally 2 ms or less when nichrome wire is used for the resistor.

[0030] Igniter 40 is attached to bottom plate 11 in a state where it is inserted from the inside of lower shell 10 so that terminal pin 42 passes through opening 15 provided in protruding cylindrical portion 13. Specifically, holding portion 30 made of a resin molded portion is provided around protruding cylindrical portion 13 provided on bottom plate 11, and igniter 40 is fixed to bottom plate 11 by being held by holding portion 30.

[0031] The retaining portion 30 is formed by injection molding (more specifically, insert molding) using a mold, and is formed by adhering an insulating fluid resin material to the bottom plate portion 11 of the lower shell 10 so that it passes through an opening 15 provided in the bottom plate portion 11 and reaches from a portion of the inner surface of the bottom plate portion 11 to a portion of the outer surface, and then solidifying it.

[0032] As the raw material for the holding portion 30 formed by injection molding, a resin material that exhibits excellent heat resistance, durability, corrosion resistance, and the like after hardening is preferably selected and used. In this case, it is not limited to thermosetting resins such as epoxy resin, but thermoplastic resins such as polybutylene terephthalate resin, polyethylene terephthalate resin, polyamide resin (e.g., nylon 6, nylon 66, etc.), polypropylene sulfide resin, and polypropylene oxide resin can also be used. When such a thermoplastic resin is selected as the raw material, it is preferable to incorporate glass fiber or the like as a filler into the resin material to ensure the mechanical strength of the holding portion 30 after molding. However, if sufficient mechanical strength can be ensured with the thermoplastic resin alone, it is not necessary to add the filler described above.

[0033] The retaining portion 30 has an inner covering portion 31 that covers part of the inner surface of the bottom plate portion 11 of the lower shell 10, an outer covering portion 32 that covers part of the outer surface of the bottom plate portion 11 of the lower shell 10, and a connecting portion 33 that is located within the opening 15 provided in the bottom plate portion 11 of the lower shell 10 and is continuous with the inner covering portion 31 and the outer covering portion 32, respectively.

[0034] The retaining portion 30 is fixed to the bottom plate portion 11 on the surfaces of the inner covering portion 31, the outer covering portion 32, and the connecting portion 33 that face the bottom plate portion 11. The retaining portion 30 is also fixed to the side and bottom surfaces of the ignition portion 41 of the igniter 40 near the lower end, and to the surface of the terminal pin 42 of the igniter 40 near the upper end.

[0035] As a result, opening 15 is completely filled with terminal pin 42 and holding portion 30, and the sealing of this portion ensures airtightness of the space inside the housing. Since opening 15 is formed in an asymmetrical shape in a plan view as described above, by filling opening 15 with connecting portion 33, opening 15 and connecting portion 33 also function as an anti-rotation mechanism that prevents holding portion 30 from rotating relative to bottom plate portion 11.

[0036] The outer covering portion 32 of the holding portion 30 is embedded in the recessed portion 14, recessed toward the interior of the housing, and open toward the opposite side of the interior of the housing. Specifically, the outer covering portion 32 of the holding portion 30 is recessed toward the top plate portion 21, and open toward the opposite side of the top plate portion 21. The holding portion 30 holds the igniter 40 with a pair of terminal pins 42 exposed from the bottom of the outer covering portion 32. The pair of terminal pins 42 protrude from the bottom of the outer covering portion 32.

[0037] A female connector portion 34 is formed on the portion of the outer covering portion 32 of the holding portion 30 facing the outside. The female connector portion 34 is a portion for receiving a male connector (not shown) of a harness for connecting the igniter 40 to a control unit (not shown), and is located in a recess 14 provided in the bottom plate portion 11 of the lower shell 10.

[0038] A portion of the terminal pin 42 of the igniter 40 near the lower end is exposed and disposed within the female connector portion 34. A male connector is inserted into the female connector portion 34, thereby establishing electrical continuity between the core wire of the harness and the terminal pin 42.

[0039] The above-described injection molding may also be performed using a lower shell 10 in which an adhesive layer is provided in advance at a predetermined position on the surface of the bottom plate portion 11 in the portion that will be covered by the holding portion 30. The adhesive layer can be formed by applying adhesive to a predetermined position on the bottom plate portion 11 in advance and then curing the adhesive.

[0040] In this way, the hardened adhesive layer is positioned between the bottom plate portion 11 and the holding portion 30, so that the holding portion 30, which is made of a resin molded portion, can be more firmly fixed to the bottom plate portion 11. Therefore, if the adhesive layer is provided in a ring shape along the circumferential direction so as to surround the opening 15 provided in the bottom plate portion 11, it is possible to ensure higher sealing performance in that portion.

[0041] Here, the adhesive to be applied in advance to the bottom plate portion 11 is preferably one containing as a raw material a resin material that has excellent heat resistance, durability, corrosion resistance, etc. after hardening, and is particularly preferably one containing as a raw material a cyanoacrylate resin or a silicone resin. In addition to the above-mentioned resin materials, materials containing raw materials such as phenolic resins, epoxy resins, melamine resins, urea resins, polyester resins, alkyd resins, polyurethane resins, polyimide resins, polyethylene resins, polypropylene resins, polyvinyl chloride resins, polystyrene resins, polyvinyl acetate resins, polytetrafluoroethylene resins, acrylonitrile butadiene styrene resins, acrylonitrile styrene resins, acrylic resins, polyamide resins, polyacetal resins, polycarbonate resins, polyphenylene ether resins, polybutylene terephthalate resins, polyethylene terephthalate resins, polyolefin resins, polyphenylene sulfide resins, polysulfone resins, polyethersulfone resins, polyarylate resins, polyetheretherketone resins, polyamideimide resins, liquid crystal polymers, styrene rubbers, and olefin rubbers can also be used as the above-mentioned adhesives.

[0042] Here, an example of a configuration has been given in which the igniter 40 can be fixed to the lower shell 10 by injection molding the retaining portion 30 made of a resin molded portion, but other alternative means can also be used to fix the igniter 40 to the lower shell 10.

[0043] A cup-shaped member 50 is attached to the bottom plate 11 so as to cover the protruding tube 13, the holding portion 30, and the igniter 40. The cup-shaped member 50 has a generally cylindrical shape with a bottom that is open at the end on the bottom plate 11 side, and includes a space therein for accommodating a transfer charge 59. The cup-shaped member 50 is positioned so that it protrudes into the combustion chamber 60 that accommodates the gas generating agent 61, with the space provided therein facing the ignition portion 41 of the igniter 40.

[0044] The cup-shaped member 50 has a top wall portion 51, a cylindrical side wall portion 52 extending from the periphery of the top wall portion 51 toward the bottom plate portion 11, and an extension portion 53 extending radially outward from the opening end, which is the end of the side wall portion 52 on the bottom plate portion 11 side.

[0045] The extension portion 53 is formed to extend along the inner surface of the bottom plate portion 11 of the lower shell 10. Specifically, the extension portion 53 has a curved shape to follow the shape of the inner bottom surface of the bottom plate portion 11 at and near the portion where the protruding tubular portion 13 is provided, and includes a tip portion 54 extending in a flange shape at its radially outer portion.

[0046] The tip 54 of the extension 53 is disposed between the bottom plate 11 and the lower support member 70 along the axial direction of the housing, and is thereby sandwiched between the bottom plate 11 and the lower support member 70 along the axial direction of the housing. As a result, the tip 54 of the extension 53 of the cup-shaped member 50 is pressed toward the bottom plate 11 by the lower support member 70, and the cup-shaped member 50 is fixed to the bottom plate 11. This prevents the cup-shaped member 50 from falling off the bottom plate 11 without using crimping or press-fitting to fix the cup-shaped member 50.

[0047] Cup-shaped member 50 has no openings in either side wall 52 or top wall 51, and surrounds an internal space. When transfer charge 59 in transfer chamber 57 is ignited by activation of igniter 40, cup-shaped member 50 bursts, deforms, or melts due to an increase in pressure in the internal space and conduction of the generated heat.

[0048] Suitable materials for the cup-shaped member 50 include metal members such as stainless steel, steel, aluminum, aluminum alloy, stainless steel, stainless steel alloy, etc., and resin members such as thermosetting resins typified by epoxy resin, polybutylene terephthalate resin, polyethylene terephthalate resin, polyamide resin (e.g., nylon 6, nylon 66, etc.), polypropylene sulfide resin, polypropylene oxide resin, etc. In particular, aluminum alloys or iron-based metal materials such as stainless steel and steel, which have relatively higher mechanical strength than aluminum, are preferred.

[0049] The method for fixing the cup-shaped member 50 is not limited to the above-described fixing method using the lower support member 70, and other fixing methods may be used. For example, the cup-shaped member 50 may be held by being press-fitted into the inner covering portion 31, and fixed to the lower shell 10 by pressing the extension portion 53 from above with the gas generating agent 61.

[0050] The transfer charge 59 filled in the transfer chamber 57 is ignited by the flame generated by the activation of the igniter 40, and generates thermal particles as it burns. The transfer charge 59 must be capable of reliably starting the combustion of the gas generant 61, and generally, a composition made of a metal powder / oxidizer, such as B / KNO3, B / NaNO3, or Sr(NO3)2, a composition made of titanium hydride / potassium perchlorate, or a composition made of B / 5-aminotetrazole / potassium nitrate / molybdenum trioxide, is used.

[0051] The enhancer charge 59 may be in a powder form, or may be formed into a predetermined shape using a binder. The enhancer charge 59 formed using a binder may have various shapes, such as granules, cylinders, sheets, spheres, single-hole cylinders, multi-hole cylinders, tablets, and the like.

[0052] Within the space inside the housing, a combustion chamber 60 containing a gas generating agent 61 is located in the space surrounding the portion in which the cup-shaped member 50 is disposed. Specifically, as described above, the cup-shaped member 50 is disposed so as to protrude into the combustion chamber 60 formed inside the housing, and the space provided in the portion facing the outer surface of the top wall portion 51 of the cup-shaped member 50 and the space provided in the portion facing the outer surface of the side wall portion 52 form the combustion chamber 60. As a result, the gas generating agent 61 is disposed adjacent to the outer surface of the cup-shaped member 50.

[0053] Furthermore, a filter 90 is arranged along the inner periphery of the housing in a part of the space that radially surrounds the combustion chamber 60 that accommodates the gas generating agent 61. The filter 90 has a cylindrical shape and is arranged so that its central axis substantially coincides with the axial direction of the housing.

[0054] The gas generating agent 61 is an agent that is ignited by thermal particles generated by the transfer charge 59 when the igniter 40 is activated, and burns to generate gas. A non-azide gas generating agent is preferably used as the gas generating agent 61, and the gas generating agent 61 is generally formed as a molded body containing a fuel, an oxidizer, and an additive.

[0055] The fuel may be, for example, a triazole derivative, a tetrazole derivative, a guanidine derivative, an azodicarbonamide derivative, a hydrazine derivative, or a combination thereof. Specifically, nitroguanidine, guanidine nitrate, cyanoguanidine, 5-aminotetrazole, or the like is preferably used.

[0056] Examples of oxidizing agents that can be used include basic metal nitrates such as basic copper nitrate, basic metal carbonates such as basic copper carbonate, perchlorates such as ammonium perchlorate and potassium perchlorate, and nitrates containing cations selected from alkali metals, alkaline earth metals, transition metals, and ammonia. Suitable nitrates include sodium nitrate and potassium nitrate.

[0057] Examples of additives include binders, slag formers, and combustion modifiers. Suitable binders include organic binders such as polyvinyl alcohol, metal salts of carboxymethyl cellulose, and stearates, as well as inorganic binders such as synthetic hydrotalcite and acid clay. Other suitable binders include polysaccharide derivatives such as hydroxyethyl cellulose, hydroxypropyl methyl cellulose, cellulose acetate, cellulose propionate, cellulose acetate butyrate, nitrocellulose, microcrystalline cellulose, guar gum, polyvinylpyrrolidone, polyacrylamide, and starch, as well as inorganic binders such as molybdenum disulfide, talc, bentonite, diatomaceous earth, kaolin, and alumina. Suitable slag formers include silicon nitride, silica, and acid clay. Suitable combustion modifiers include metal oxides, ferrosilicon, activated carbon, and graphite.

[0058] The shape of the molded body of gas generating agent 61 may be various, including granular, pellet-like, cylindrical, or other particulate shapes, and disc-like shapes. Furthermore, for cylindrical molded bodies, perforated molded bodies having through holes inside the molded body (for example, a single-hole cylindrical shape or a multi-hole cylindrical shape) are also used. These shapes are preferably selected as appropriate depending on the specifications of the airbag device into which disk-shaped gas generator 100 is incorporated, and it is preferable to select an optimal shape depending on the specifications, such as selecting a shape in which the gas generation rate changes over time when gas generating agent 61 is burned. Furthermore, in addition to the shape of gas generating agent 61, it is preferable to select the size and filling amount of the molded body as appropriate, taking into consideration the burning rate, pressure exponent, etc. of gas generating agent 61.

[0059] The filter 90 can be made of, for example, metal wire such as stainless steel or iron, wound and sintered, or a mesh of woven metal wires pressed together. Specific examples of mesh materials that can be used include knitted wire mesh, plain woven wire mesh, and an aggregate of crimped metal wires.

[0060] Alternatively, a perforated metal sheet wound around the filter 90 may be used. Examples of perforated metal sheets include expanded metal, which is a metal sheet with staggered cuts and then expanded to form holes and form a mesh, and hook metal, which is a metal sheet with holes drilled and flattened by crushing any burrs that may form around the holes. The size and shape of the holes can be varied as needed, and holes of different sizes and shapes may be included in the same metal sheet. Suitable metal sheets include mild steel and stainless steel, as well as non-ferrous metal sheets such as aluminum, copper, titanium, nickel, and alloys thereof.

[0061] The filter 90 functions as a cooling means for cooling the gas generated in the combustion chamber 60 by removing the high-temperature heat of the gas as the gas passes through the filter 90, and also functions as a removal means for removing residues (slag) contained in the gas. Therefore, in order to sufficiently cool the gas and prevent the residues from being released to the outside, it is necessary to ensure that the gas generated in the combustion chamber 60 passes through the filter 90. The filter 90 is disposed at a distance from the peripheral wall 22 of the upper shell 20 that constitutes a part of the peripheral wall of the housing, so that a gap 28 of a predetermined size is formed between the filter 90 and the peripheral wall 22.

[0062] A plurality of gas outlets 23 are provided in the peripheral wall 22 of the upper shell 20 in a portion facing the filter 90. The plurality of gas outlets 23 are for directing the gas that has passed through the filter 90 to the outside of the housing.

[0063] Additionally, a metal sealing tape 24 is attached to the inner peripheral surface of the peripheral wall portion 22 of the upper shell 20 as a sealing member to close the plurality of gas ejection ports 23. As this sealing tape 24, an aluminum foil with an adhesive member applied to one side can be suitably used, and the sealing tape 24 ensures the airtightness of the combustion chamber 60.

[0064] A lower support member 70 is disposed in the vicinity of the end of the combustion chamber 60 that is located on the bottom plate portion 11 side. As a result, the lower support member 70 is located between the bottom plate portion 11 and the gas generating agent 61 in the vicinity of the end of the combustion chamber 60.

[0065] The lower support member 70 has an annular plate-shaped base portion 71 that is fitted to the bottom plate portion 11 so as to fit along the inner bottom surface of the bottom plate portion 11, an opposing portion 72 that faces the inner circumferential surface of the peripheral wall portion 12 closer to the bottom plate portion 11, and a tubular upright portion 73 that stands upright from the base portion 71 toward the top plate portion 21. The opposing portion 72 extends from the outer edge of the base portion 71, and the upright portion 73 extends from the inner edge of the base portion 71. The upright portion 73 covers the outer peripheral surface of the protruding tubular portion 13 of the lower shell 10 and the outer peripheral surface of the inner covering portion 31 of the holding portion 30 via the extension portion 53 of the cup-shaped member 50.

[0066] The lower support member 70 is formed, for example, by pressing a metal plate-shaped member, and is preferably made of a steel plate such as ordinary steel or special steel (for example, a cold-rolled steel plate or a stainless steel plate). Here, as a modified example, the lower support member 70 may be omitted.

[0067] An upper support member 80 is disposed at the end of the combustion chamber 60 that is located on the top plate portion 21 side. The upper support member 80 has a substantially disk-like shape, and is disposed between the filter 90 and the top plate portion 21 so as to cover the boundary between the filter 90 and the top plate portion 21. As a result, the upper support member 80 is positioned near the end of the combustion chamber 60, between the top plate portion 21 and the gas generating agent 61.

[0068] The upper support member 80 has a base 81 that abuts against the top plate 21, and an abutment portion 82 that stands upright from the periphery of the base 81. The abutment portion 82 abuts against the inner circumferential surface of the axial end portion of the filter 90 that is located on the top plate 21 side.

[0069] The upper support member 80 is a member for fixing the filter 90 to the housing, and also functions as an outflow prevention means for preventing gas generated in the combustion chamber 60 from flowing out through the gap between the upper end of the filter 90 and the top plate portion 21 without passing through the inside of the filter 90 when the igniter 40 is activated. For this reason, the upper support member 80 is formed, for example, by pressing a metal plate-shaped member, and is preferably made of a member made of a steel plate such as ordinary steel or special steel (for example, a cold-rolled steel plate or a stainless steel plate).

[0070] A disk-shaped cushion material 85 is disposed inside the upper support member 80 so as to come into contact with the gas generating agent 61 accommodated in the combustion chamber 60. As a result, the cushion material 85 is positioned between the top plate portion 21 and the gas generating agent 61 in the portion of the combustion chamber 60 on the top plate portion 21 side, and presses the gas generating agent 61 toward the bottom plate portion 11 side.

[0071] The cushioning material 85 is provided for the purpose of preventing the gas generating agent 61, which is made of a molded body, from being crushed by vibration or the like, and is preferably made of a material such as a ceramic fiber molded body, rock wool, foamed resin (for example, foamed silicone, foamed polypropylene, foamed polyethylene, foamed urethane, etc.), or rubber such as chloroprene and EPDM.

[0072] The support member 91 is a member that supports the filter 90. The support member 91 has a mounting portion 91a, an outer wall portion 91b, and a support portion 91c.

[0073] The mounting portion 91a is placed on the tip surface (upper end surface) of the peripheral wall portion 12. The mounting portion 91a is in contact with the inner peripheral surface of the peripheral wall portion 22. The mounting portion 91a is provided along the tip surface of the peripheral wall portion 12 and the inner peripheral surface of the peripheral wall portion 22, and is provided in an annular shape along the circumferential direction of the housing. For example, the mounting portion 91a is welded to the tip surface of the peripheral wall portion 12 and / or the inner peripheral surface of the peripheral wall portion 22 by, for example, laser welding or friction welding. It is preferable that the mounting portion 91a is welded to the tip surface of the peripheral wall portion 12 and the inner peripheral surface of the peripheral wall portion 22.

[0074] The outer wall portion 91b supports the filter 90 from the outside in the radial direction of the housing. The outer wall portion 91b is connected to the inner end of the mounting portion 91a in the radial direction of the housing and protrudes toward the bottom plate portion 11 beyond the mounting portion 91a. The end face (upper end face) of the outer wall portion 91b facing the top plate portion 21 is flush with the end face (upper end face) of the mounting portion 91a facing the top plate portion 21. The outer wall portion 91b is in contact with the inner peripheral surface of the peripheral wall portion 12. The outer wall portion 91b is in contact with the outer peripheral surface of the filter 90. The outer wall portion 91b is provided along the inner peripheral surface of the peripheral wall portion 12 and the outer peripheral surface of the filter 90, and is provided in an annular shape along the circumferential direction of the housing. For example, the outer wall portion 91b is welded to the inner peripheral surface of the peripheral wall portion 12 by, for example, laser welding or friction welding.

[0075] The support portion 91c protrudes radially inward from the outer wall portion 91b on the bottom plate portion 11 side of the outer wall portion 91b's end face (upper end face) on the top plate portion 21 side. The support portion 91c protrudes radially inward from the inner circumferential surface of the filter 90. The end face (lower end face) of the support portion 91c on the bottom plate portion 11 side is flush with the end face (lower end face) of the outer wall portion 91b on the bottom plate portion 11 side. The support portion 91c faces the top plate portion 21 in the axial direction of the housing. The filter 90 is disposed between the support portion 91c and the top plate portion 21, and is sandwiched between the support portion 91c and the top plate portion 21. The support portion 91c is provided along the end face (lower end face) of the filter 90 on the bottom plate portion 11 side, and is provided in an annular shape along the circumferential direction of the housing.

[0076] The support member 91 is provided in an annular shape along the circumferential direction of the housing. The support member 91 also functions as an outflow prevention means that prevents gas generated in the combustion chamber 60 from flowing out through the gap between the lower end of the filter 90 and the support member 91 without passing through the inside of the filter 90 when the igniter 40 is activated.

[0077] Because the filter 90 can be supported by the support member 91, it is not necessary to support the filter 90 on the bottom plate portion 11. This allows the filter 90 to be shorter than when the filter is supported on the bottom plate portion 11, and the amount of material used to form the filter 90 can be reduced, resulting in a lighter filter 90. Since the gas outlet 23 is provided in the upper shell 20, even if the filter 90 is extended to the bottom plate portion 11, the cooling effect of the extended portion is small. Therefore, compared to when the filter is supported on the bottom plate portion 11, even if the filter 90 is shortened, it can be cooled efficiently and residue can be captured efficiently. Furthermore, by adjusting the thickness of the filter 90, the cooling effect and pressure resistance during operation (strength of the filter 90) can be easily adjusted. Furthermore, the filter 90 can maintain the positioning function of the gas generating agent 61 and the function of preventing other components from moving, similar to when the filter is supported on the bottom plate portion 11. In addition, the support member 91 can maintain the bypass prevention function (the function of preventing gas from being discharged without passing through the filter 90) and the positioning function of the filter 90, which are equivalent to when the filter is supported by the bottom plate portion 11.

[0078] Next, with reference to FIG. 1, a procedure for assembling disk-shaped gas generator 100 in this embodiment will be described.

[0079] First, the igniter 40 is fixed to the lower shell 10 by injection molding the retaining portion 30 made of a resin molded portion. Then, the side wall portion 52 of the cup-shaped member 50, which houses the transfer charge 59, is press-fitted into the retaining portion 30 of the lower shell 10 to be fixed. Next, the lower support member 70 is placed on the tip portion 54 of the extension portion 53 of the cup-shaped member 50, and then the support member 91 is placed on the tip surface (upper end surface) of the peripheral wall portion 12, and the filter 90 is inserted and disposed inside the outer wall portion 91b toward the support portion 91c of the support member 91.

[0080] Gas generating agent 61 is then filled from the inside of filter 90, and upper support member 80 with cushioning material 85 therebetween is inserted into the upper end portion of filter 90. Thereafter, upper shell 20, with gas ejection port 23 closed with sealing tape 24, is placed over lower shell 10, and lower shell 10 and upper shell 20 are welded together. This completes the assembly of disc-type gas generator 100 having the structure shown in FIG. 1 .

[0081] Here, in disk-shaped gas generator 100 of the present embodiment, no opening is provided in cup-shaped member 50, and therefore the step of filling transfer charge 59 into transfer chamber 57 provided inside cup-shaped member 50 can be carried out very easily. This is because cup-shaped member 50 itself is made of a fragile member with low mechanical strength so that a part of the cup-shaped member will rupture, deform or melt when disk-shaped gas generator 100 is activated. In other words, the work of closing the opening provided in the cup-shaped member in order to fill it with transfer charge 59, such as with aluminum tape or a closing plate, which was necessary when a cup-shaped member having an opening was used, is no longer necessary, and the manufacturing process can be greatly simplified.

[0082] Next, with reference to FIG. 1, the operation of disk-shaped gas generator 100 in this embodiment will be described.

[0083] When a vehicle equipped with disk-shaped gas generator 100 collides, the collision is detected by collision detection means separately provided in the vehicle, and based on this, a control unit separately provided in the vehicle supplies electricity to activate igniter 40. Transfer charge 59 accommodated in transfer chamber 57 is ignited by the flame generated by the activation of igniter 40, and begins to burn.

[0084] At this time, immediately after the igniter 40 is activated, the ignition charge loaded in the ignition section 41 burns rapidly, causing the squib cup of the ignition section 41 to burst, and the heat generated by the rapid combustion of the ignition charge is transmitted to the transfer charge 59 filled in the transfer chamber 57.

[0085] Next, when the thrust reaches the inside of the cup-shaped member 50, the cup-shaped member 50, which is made of a relatively fragile material, explodes, deforms, or melts. This explosion, deformation, or melting of the cup-shaped member 50 occurs later than the ignition of the transfer charge 59 by the heat particles generated by the combustion of the ignition charge. Here, the transfer charge 59 of the cup-shaped member 50 is subjected to the thrust generated by the combustion of the ignition charge and is scattered and dispersed inside the cup-shaped member 50.

[0086] Therefore, the transfer charge 59 located farther from the igniter 40 is also ignited by the thermal particles in a shorter time and begins to burn, which results in a significant increase in pressure and temperature in the space inside the cup-shaped member 50. As a result, the cup-shaped member 50 bursts, deforms, or melts in a shorter time, and a large amount of thermal particles generated by the combustion of the transfer charge 59 flows into the combustion chamber 60 quickly. These thermal particles are not affected by the cushion material 85 provided in the upper shell 20 and come into contact with the gas generant 61 without being deactivated.

[0087] In this way, the transfer charge 59 and a large amount of heat particles generated by the transfer charge 59 flow into the combustion chamber 60, igniting and burning the gas generating agent 61 contained in the combustion chamber 60, generating a large amount of gas. The gas generated in the combustion chamber 60 passes through the inside of the filter 90, and in this process, heat is removed by the filter 90 and the gas is cooled, and slag contained in the gas is removed by the filter 90 and flows into the gap 28.

[0088] Then, as the pressure in the space inside the housing increases due to the combustion of gas generating agent 61, sealing tape 24 that has been closing gas outlet 23 provided in upper shell 20 ruptures, and gas is ejected to the outside of the housing through gas outlet 23. The ejected gas is introduced into the inside of an airbag provided adjacent to disc-shaped gas generator 100, and inflates and deploys the airbag.

[0089] Note that if the cup-shaped member 50 is made of iron or stainless steel, the strength is higher than if the cup-shaped member 50 were made of aluminum. Therefore, the cup-shaped member 50 does not rupture, deform, or melt in the initial stage of combustion of the enhancer charge 59. At this time, the internal pressure of the cup-shaped member 50 increases until a predetermined time has elapsed at which the cup-shaped member ruptures, deforms, or melts. Then, once the internal pressure reaches a certain level, the cup-shaped member 50 ruptures, deforms, or melts. Therefore, by using an iron-based metal material with high mechanical strength, such as iron or stainless steel, for the cup-shaped member 50, the mechanical strength can be increased to sufficiently promote the combustion of the enhancer charge 59 when the cup-shaped member 50 is ruptured, thereby rupturing the cup-shaped member 50. Such an improvement in the mechanical strength of the cup-shaped member 50 can be achieved by increasing its thickness, even when a metal with low strength, such as aluminum, is used. In this case, the thickness is preferably 0.4 mm to 1.5 mm, and more preferably 0.6 mm to 1.2 mm. Here, if the cup-shaped member 50 is made of iron, the strength is relatively high, so the lower support member 70 having the function of directing the flame may be omitted.

[0090] As explained above, disk-shaped gas generator 100 in the first embodiment of the present invention described above is a cylindrical housing having bottom plate portion 11, top plate portion 21 opposing bottom plate portion 11, peripheral wall portion 12 extending from the outer peripheral edge of bottom plate portion 11 toward top plate portion 21, and peripheral wall portion 22 extending from the outer peripheral edge of top plate portion 21 toward bottom plate portion 11 and having a plurality of gas ejection ports 23 arranged therein; mounting portion 91a mounted on a tip end surface of peripheral wall portion 12, outer wall portion 91b connected to an inner end of mounting portion 91a in the radial direction of the housing and protruding toward bottom plate portion 11 beyond mounting portion 91a, and outer wall portion 91b extending beyond the end face of outer wall portion 91b on the top plate portion 21 side. The housing is provided with: a support member 91 having a support portion 91c protruding radially inward from an outer wall portion 91b on the bottom plate portion 11 side and arranged in a ring shape along the circumferential direction of the housing; a filter 90 sandwiched between the top plate portion 21 and the support portion 91c and arranged in a ring shape along the circumferential direction; a gas generating agent 61 that is contained in a space surrounded by the bottom plate portion 11, the top plate portion 21, the peripheral wall portion 12, the support member 91, and the filter 90 and generates gas when burned; and an igniter 40 that ignites and burns the gas generating agent 61; the mounting portion 91a is welded to the tip surface of the peripheral wall portion 12 and / or the inner surface of the peripheral wall portion 22, and the outer wall portion 91b is welded to the inner surface of the peripheral wall portion 12.

[0091] This allows the filter 90 to be supported by an annular support member 91 placed on the tip surface of the peripheral wall portion 12, and also prevents gas from leaking between the filter 90 and the support member 91, thereby preventing the filter 90 from becoming larger and preventing gas from being discharged outside the housing without passing through the filter 90.

[0092] Second Embodiment A disk-shaped gas generator 200 according to a second embodiment of the present invention will now be described with reference to Fig. 2. In this embodiment, reference numerals having the same last two digits as those in the first embodiment described above are similar and therefore explanations may be omitted. Furthermore, parts that are not particularly described are similar to disk-shaped gas generator 100 of the first embodiment described above and therefore explanations may be omitted.

[0093] As shown in FIG. 2, disc-shaped gas generator 200 differs from disc-shaped gas generator 100 mainly in that disc-shaped gas generator 200 is provided with support member 191 instead of support member 91. As shown in FIG.

[0094] The support member 191 differs from the support member 91 mainly in that it further has an inner wall portion 191d having a substantially L-shaped cross section.

[0095] The inner wall portion 191d supports the filter 190 from the inside in the radial direction of the housing. The inner wall portion 191d protrudes from the support portion 191c toward the top plate portion 121, on a position more inward than the filter 190 in the radial direction of the housing. The inner wall portion 191d is a separate body from the support portion 191c, and is provided so as to extend radially outward from the housing and then toward the top plate portion 121. The inner wall portion 191d is fixed to the support portion 191c. For example, the inner wall portion 191d is fixed to the support portion 191c by being adhered to the support portion 191c with an adhesive or the like. The inner wall portion 191d is in contact with the inner circumferential surface of the filter 190. The inner wall portion 191d is provided along the inner circumferential surface of the filter 190, and is provided in an annular shape along the circumferential direction of the housing. An outer surface (outer peripheral surface) 191e of the inner wall portion 191d in the radial direction of the housing is provided along the axial direction of the housing. The outer surface 191e of the inner wall portion 191d may be inclined like an outer surface 391e of an inner wall portion 391d described later.

[0096] The filter 190 is sandwiched between the outer wall portion 191b and the inner wall portion 191d.

[0097] As explained above, in disk-shaped gas generator 200 of the second embodiment of the present invention described above, support portion 191c protrudes radially inward further than filter 190, and support member 191 has inner wall portion 191d that protrudes from support portion 191c towards top plate portion 121, radially inside filter 190, and filter 190 is sandwiched between outer wall portion 191b and inner wall portion 191d.

[0098] This allows the inner wall portion 191d to support the filter 190 from the inside and further prevents gas from leaking between the filter 190 and the support member 191, thereby further preventing gas from being discharged to the outside of the housing without passing through the filter 190.

[0099] Furthermore, in disk-shaped gas generator 200 in the second embodiment of the present invention described above, inner wall portion 191d is a separate body from support portion 191c, and is provided facing radially outward and then facing the top plate portion 121 side.

[0100] This allows the inner wall portion 191d to be detached from the support portion 191c, and allows inner wall portions of different sizes to be attached to the support portion 191c, depending on the shape of the filter.

[0101] <Third embodiment> A disk-shaped gas generator 300 according to a third embodiment of the present invention will now be described with reference to Fig. 3. In this embodiment, reference numerals having the same last two digits as those in the first embodiment described above are similar, and therefore explanations may be omitted. Furthermore, parts that are not particularly described are similar to disk-shaped gas generator 100 of the first embodiment described above, and therefore explanations may be omitted.

[0102] As shown in FIG. 3, disc-shaped gas generator 300 differs from disc-shaped gas generator 100 mainly in that disc-shaped gas generator 300 is provided with support member 291 instead of support member 91.

[0103] The support member 291 differs from the support member 91 mainly in that it further has an inner wall portion 291d.

[0104] The inner wall portion 291d supports the filter 290 from the inside in the radial direction of the housing. The inner wall portion 291d protrudes from the support portion 291c toward the top plate portion 221, on a position more inward than the filter 290 in the radial direction of the housing. The inner wall portion 291d is integral with the support portion 291c. The inner wall portion 291d is in contact with the inner circumferential surface of the filter 290. The inner wall portion 291d is provided along the inner circumferential surface of the filter 290, and is provided in an annular shape along the circumferential direction of the housing. An outer surface (outer circumferential surface) 291e of the inner wall portion 291d in the radial direction of the housing is provided along the axial direction of the housing.

[0105] The filter 290 is sandwiched between the outer wall portion 291b and the inner wall portion 291d.

[0106] As explained above, in disk-shaped gas generator 300 of the third embodiment of the present invention described above, support portion 291c protrudes radially inward further than filter 290, and support member 291 has inner wall portion 291d that protrudes from support portion 291c towards top plate portion 221, radially inside filter 290, and filter 290 is sandwiched between outer wall portion 291b and inner wall portion 291d.

[0107] This allows the inner wall portion 291d to support the filter 290 from the inside and further prevents gas from leaking between the filter 290 and the support member 291, thereby further preventing gas from being discharged to the outside of the housing without passing through the filter 290.

[0108] Moreover, in disk-shaped gas generator 300 in the third embodiment of the present invention described above, inner wall portion 291d is integral with support portion 291c.

[0109] This makes it difficult for inner wall portion 291d to separate from support portion 291c, allowing inner wall portion 291d to more firmly support filter 290. Therefore, gas leakage from between filter 290 and support member 291 can be further suppressed, and gas can be further suppressed from being discharged to the outside of the housing without passing through filter 290.

[0110] <Fourth embodiment> A disk-shaped gas generator 400 according to a fourth embodiment of the present invention will now be described with reference to FIG. 4. In this embodiment, reference numerals having the same last two digits as those in the third embodiment described above are similar, and therefore descriptions thereof may be omitted. Furthermore, portions that are not particularly described are similar to disk-shaped gas generator 300 of the third embodiment described above, and therefore descriptions thereof may be omitted.

[0111] As shown in FIG. 4, disk-shaped gas generator 400 differs from disk-shaped gas generator 300 mainly in that disk-shaped gas generator 400 is provided with support member 391 instead of support member 291. As shown in FIG.

[0112] The support member 391 differs from the support member 291 mainly in that the support member 391 has an inner wall portion 391d instead of the inner wall portion 291d.

[0113] The inner wall portion 391d differs from the inner wall portion 291d mainly in that an outer surface (outer peripheral surface) 391e of the inner wall portion 391d in the radial direction of the housing is inclined with respect to the axial direction of the housing. The outer surface 391e is inclined so as to be positioned outward in the radial direction of the housing as it approaches the bottom plate portion 311.

[0114] The filter 390 is sandwiched between the outer wall portion 391b and the inner wall portion 391d.

[0115] As explained above, in disk-shaped gas generator 400 in the above-mentioned fourth embodiment of the present invention, outer surface 391e of inner wall portion 391d in the radial direction is inclined so as to be positioned radially outward as it approaches bottom plate portion 311.

[0116] This brings filter 390 and inner wall 391d into surface contact, further preventing a gap from being formed between filter 390 and inner wall 391d. This further prevents gas from leaking between filter 390 and support member 391, further preventing gas from being discharged to the outside of the housing without passing through filter 390.

[0117] Fifth Embodiment A disk-shaped gas generator 500 according to a fifth embodiment of the present invention will now be described with reference to Fig. 5. In this embodiment, reference numerals having the same last two digits as those in the first embodiment described above are similar, and therefore explanations may be omitted. Furthermore, parts that are not particularly described are similar to disk-shaped gas generator 100 of the first embodiment described above, and therefore explanations may be omitted.

[0118] As shown in FIG. 5, disk-shaped gas generator 500 differs from disk-shaped gas generator 100 mainly in that disk-shaped gas generator 500 includes upper shell 420 instead of upper shell 20, and includes support member 491 instead of support member 91.

[0119] The upper shell 420 differs from the upper shell 20 mainly in that it has a peripheral wall 422, which is shorter than the peripheral wall 22, instead of the peripheral wall 22. The peripheral wall 422 and the peripheral wall 412 are spaced apart from each other.

[0120] The support member 491 differs from the support member 91 mainly in that it further includes a peripheral wall portion 491f.

[0121] The peripheral wall portion 491f protrudes from the mounting portion 491a toward the top plate portion 421 and contacts the inner peripheral surface of the peripheral wall portion 422. The peripheral wall portion 491f is provided along the inner peripheral surface of the peripheral wall portion 422 and is provided in an annular shape along the circumferential direction of the housing. The mounting portion 491a and the peripheral wall portion 491f are provided to close the gap between the peripheral wall portion 412 and the peripheral wall portion 422. In other words, the gap between the peripheral wall portion 412 and the peripheral wall portion 422 is closed by the mounting portion 491a and the peripheral wall portion 491f. The support member 491 is welded to the peripheral wall portion 412, the peripheral wall portion 422, and the flange portion 425, and a weld portion 492 is formed so as to hide the mounting portion 491a and the peripheral wall portion 491f.

[0122] As explained above, in disk-shaped gas generator 500 in the above-mentioned fifth embodiment of the present invention, peripheral wall portion 422 is spaced apart from peripheral wall portion 412, and support member 491 is provided to close the gap between peripheral wall portion 412 and peripheral wall portion 422, and is welded to peripheral wall portion 412 and peripheral wall portion 422.

[0123] This makes it possible to prevent a gap from being formed between support member 491 and peripheral wall portion 412, even when peripheral wall portion 412 and peripheral wall portion 422 are spaced apart. Therefore, gas leakage from between support member 491 and peripheral wall portion 412 can be further prevented, and gas can be further prevented from being discharged to the outside of the housing without passing through filter 490.

[0124] Sixth Embodiment A disk-shaped gas generator 600 according to a sixth embodiment of the present invention will now be described with reference to Fig. 6. In this embodiment, reference numerals having the same last two digits as those in the first embodiment described above are similar and therefore explanations may be omitted. Furthermore, parts that are not particularly described are similar to disk-shaped gas generator 100 of the first embodiment described above and therefore explanations may be omitted.

[0125] As shown in FIG. 6, disk-shaped gas generator 600 differs from disk-shaped gas generator 100 mainly in that disk-shaped gas generator 600 is further provided with heat insulating member 593 .

[0126] The peripheral wall portion 522 and the outer peripheral surface of the peripheral wall portion 512 in the radial direction of the housing are welded closer to the bottom plate portion 511 than the support member 591, and a welded portion 592 between the peripheral wall portion 522 and the outer peripheral surface of the peripheral wall portion 512 is formed closer to the bottom plate portion 511 than the support member 591.

[0127] The heat shielding member 593 shields heat from the welded portion 592 so that the heat is less likely to be transmitted to the gas generating agent 561, etc. The heat shielding member 593 is supported by the support member 591 so as to face the welded portion 592 across the peripheral wall portion 512. The heat shielding member 593 has a fixing portion 593a and a wall portion 593b.

[0128] Fixing portion 593a is fixed to an end surface (lower end surface) of support portion 591c on the side of bottom plate portion 511. For example, fixing portion 593a is fixed to the end surface (lower end surface) of support portion 591c on the side of bottom plate portion 511 by adhesive, welding, or the like. Fixing portion 593a is provided along the radial direction of the housing and is also provided in an annular shape along the circumferential direction of the housing.

[0129] Wall portion 593b protrudes from fixed portion 593a toward bottom plate portion 511. Wall portion 593b faces welded portion 592 with peripheral wall portion 512 sandwiched therebetween. That is, wall portion 593b and welded portion 592 face each other in the radial direction of the housing with peripheral wall portion 512 sandwiched therebetween. Wall portion 593b is in contact with the inner circumferential surface of peripheral wall portion 512. Wall portion 593b is provided along the inner circumferential surface of peripheral wall portion 512, and is provided in an annular shape along the circumferential direction of the housing.

[0130] For example, the heat shielding member 593 is formed of a foam material cushion, a fiber cushion, aluminum foil containing a metal film, a heat insulating member, or the like.

[0131] As explained above, in disk-shaped gas generator 600 according to the sixth embodiment of the present invention described above, peripheral wall portion 522 and the outer peripheral surface of peripheral wall portion 512 in the radial direction are welded closer to bottom plate portion 511 than support member 591, and heat insulating member 593 is provided that is supported by support member 591 so as to face welded portion 592 between peripheral wall portion 522 and the outer peripheral surface of peripheral wall portion 512, with peripheral wall portion 512 in between.

[0132] According to this, the heat shield member 593 can prevent the heat of the welded portion 592 from being transferred to the gas generating agent 561 and the like, and therefore, the gas generating agent 561 and the like can be prevented from burning during welding and the like.

[0133] Seventh Embodiment A disk-shaped gas generator 700 according to the seventh embodiment of the present invention will now be described with reference to Fig. 7. In this embodiment, reference numerals having the same last two digits as those in the sixth embodiment described above are similar and therefore descriptions thereof may be omitted. Furthermore, portions that are not particularly described are similar to disk-shaped gas generator 600 of the sixth embodiment described above and therefore descriptions thereof may be omitted.

[0134] 7, disk-shaped gas generator 700 differs from disk-shaped gas generator 600 mainly in that heat insulating member 693 is spaced apart from peripheral wall portion 612 in the radial direction of the housing. Specifically, wall portion 693b is spaced apart from peripheral wall portion 612 in the radial direction of the housing.

[0135] As explained above, in disk-shaped gas generator 700 in the seventh embodiment of the present invention described above, heat insulating member 693 is provided spaced apart from peripheral wall portion 612 in the radial direction.

[0136] According to this, the gap (air layer) between the heat shield member 693 and the peripheral wall portion 612 can prevent the heat of the welding portion 692 from being transferred to the gas generating agent 661, etc., and therefore, the combustion of the gas generating agent 661, etc., during welding, etc. can be prevented.

[0137] Although the embodiments of the present invention have been described above, they are merely illustrative examples and do not particularly limit the present invention, and specific configurations and the like can be modified in design as appropriate. Furthermore, the actions and effects described in the embodiments of the invention are merely a list of the most preferred actions and effects resulting from the present invention, and the actions and effects of the present invention are not limited to those described in the embodiments of the present invention. For example, in the gas generators of the above embodiments, if the interior of the housing is in a sealed state (for example, if the upper shell and the lower shell are connected by welding), the contact portion between the first peripheral wall portion (the peripheral wall portion of the lower shell) and at least one of the mounting portion and the outer wall portion may be welded, or the contact portion between the second peripheral wall portion (the peripheral wall portion of the upper shell) and the mounting portion may be welded.

[0138] Furthermore, in the first embodiment described above, a case has been described in which disk-shaped gas generator 100 is provided with lower support member 70, but the present invention is not limited to this. The disk-shaped gas generator does not have to be provided with a lower support member. The same applies to the second to seventh embodiments.

[0139] In the second embodiment, the inner wall portion 191d is annular, but this is not limiting. For example, multiple inner wall portions may be arranged in the circumferential direction of the housing, with or without gaps between them. The same applies to the third and fourth embodiments.

[0140] In the fifth, sixth, and seventh embodiments described above, an inner wall portion such as the inner wall portion 191d, the inner wall portion 291d, or the inner wall portion 391d may be provided.

[0141] In the sixth embodiment described above, the heat shield 593 is annular, but this is not limiting. For example, multiple heat shields may be arranged circumferentially around the housing, with or without gaps between them. The same applies to the seventh embodiment. [Explanation of symbols]

[0142] 10,110,210,310,410,510,610 Lower side shell 11,111,211,311,411,511,611 Bottom plate part 12,112,212,312,412,512,612 Peripheral wall part 13,113,213,313,413,513,613 Projected tube part 14,114,214,314,414,514,614 recessed part 15,115,215,315,415,515,615 openings 20,120,220,320,420,520,620 Upper side shell 21,121,221,321,421,521,621 Top plate 22,122,222,322,422,522,622 Peripheral wall part 23,123,223,323,423,523,623 Gas outlet 24,124,224,324,424,524,624 Sealing tape 25,125,225,325,425,525,625 Flange 28,128,228,328,428,528,628 Gap 30,130,230,330,430,530,630 Holding part 31,131,231,331,431,531,631 Inner coating 32,132,232,332,432,532,632 Outer covering part 33,133,233,333,433,533,633 Connection part 34,134,234,334,434,534,634 Female connector part 40,140,240,340,440,540,640 Igniter 41,141,241,341,441,541,641 Ignition part 42,142,242,342,442,542,642 terminal pins 50,150,250,350,450,550,650 Cup-shaped member 51,151,251,351,451,551,651 Top wall part 52,152,252,352,452,552,652 Side wall 53,153,253,353,453,553,653 Extension part 54,154,254,354,454,554,654 Tip 57,157,257,357,457,557,657 Fire transmission room 59,159,259,359,459,559,659 Transfer powder 60,160,260,360,460,560,660 combustion chamber 61,161,261,361,461,561,661 Gas Generants 70,170,270,370,470,570,670 Lower support member 71,171,271,371,471,571,671 Base 72,172,272,372,472,572,672 Opposite part 73,173,273,373,473,573,673 Standing section 80,180,280,380,480,580,680 Upper support member 81,181,281,381,481,581,681 base 82,182,282,382,482,582,682 Contact part 85,185,285,385,485,585,685 Cushioning material 90,190,290,390,490,590,690 filters 91,191,291,391,491,591,691 Support members 91a, 191a, 291a, 391a, 491a, 591a, 691a Placement section 91b,191b,291b,391b,491b,591b,691b External wall part 91c,191c,291c,391c,491c,591c,691c Support part 92,192,292,392,492,592,692 Welds 100, 200, 300, 400, 500, 600, 700 Disk type gas generator 191d,291d,391d Inner wall part 191e,291e,391e External surface 491f Peripheral wall part 593,693 Heat shielding material 593a,693a Fixed part 593b,693b wall

Claims

1. a cylindrical housing having a bottom plate, a top plate opposite to the bottom plate, a first peripheral wall extending from an outer periphery of the bottom plate toward the top plate, and a second peripheral wall extending from the outer periphery of the top plate toward the bottom plate and having a plurality of gas outlets disposed therein; a support member provided annularly along the circumferential direction of the housing, the support member having: a mounting portion to be mounted on a tip end surface of the first circumferential wall portion; an outer wall portion connected to an inner end of the mounting portion in the radial direction of the housing and protruding toward the bottom plate portion further than the mounting portion; and a support portion protruding radially inward from the outer wall portion on a side closer to the bottom plate portion than an end face of the outer wall portion on the top plate portion side; a filter that is sandwiched between the top plate portion and the support portion and is provided annularly along the circumferential direction; a gas generating agent that is contained in a space surrounded by the bottom plate portion, the top plate portion, the first peripheral wall portion, the support member, and the filter and that generates gas by burning; an igniter that ignites and burns the gas generating agent, a contact portion between the first peripheral wall portion and at least one of the mounting portion and the outer wall portion, or a contact portion between the second peripheral wall portion and the mounting portion, being welded.

2. the support portion protrudes radially inward beyond the filter, the support member has an inner wall portion that protrudes from the support portion toward the top plate portion, the inner wall portion being located inside the filter in the radial direction, 2. The gas generator according to claim 1, wherein the filter is sandwiched between the outer wall portion and the inner wall portion.

3. 3. The gas generator according to claim 2, wherein an outer surface of the inner wall portion in the radial direction is inclined so as to be positioned radially outward as it approaches the bottom plate portion.

4. the second peripheral wall portion is spaced apart from the first peripheral wall portion, 2. The gas generator according to claim 1, wherein the support member is provided so as to close a gap between the first peripheral wall portion and the second peripheral wall portion, and is welded to the first peripheral wall portion and the second peripheral wall portion.

5. the second peripheral wall portion and an outer peripheral surface of the first peripheral wall portion in the radial direction are welded to each other on a side closer to the bottom plate portion than the support member, 2. The gas generator according to claim 1, further comprising a heat insulating member supported by the support member so as to face a welded portion between the second peripheral wall portion and the outer peripheral surface of the first peripheral wall portion, with the first peripheral wall portion interposed therebetween.

6. 6. The gas generator according to claim 5, wherein the heat insulating member is provided spaced apart from the first circumferential wall portion in the radial direction.

Images