gas generator

Abstract

This gas generator offers enhanced safety by suppressing excessive pressure buildup inside the housing. [Solution] The gas generator 1A comprises a metal housing having a combustion chamber S1 inside and an opening 21 in part of it, a metal igniter housing 45 that houses an igniter 42a and faces the inside of the combustion chamber S1, a terminal pin 43, and a resin part 41 that fixes the igniter housing 45 to the housing. The igniter housing 45 has a cup 42c1 configured with one end in the axial direction as an open end, and a plug 42b that closes the open end and has a terminal pin 43 erected on it. The resin part 41 closes the opening 21 by being positioned to fill the space between the housing in the part that defines the opening 21 and the igniter housing 45. When viewed along the axial direction, the igniter housing 45 overlaps only the opening 21 and does not overlap the housing in the part that defines the opening 21.

Description

Technical Field

[0001] The present invention relates to a gas generator that is preferably incorporated into an airbag device as an occupant protection device equipped in an automobile or the like.

Background Art

[0002] Conventionally, from the perspective of protecting occupants of automobiles and the like, airbag devices as occupant protection devices have become widespread. The airbag device is equipped for the purpose of protecting the occupant from the impact generated during a vehicle collision or the like, and when a vehicle collides or the like, the airbag is instantaneously inflated and deployed, and the airbag serves as a cushion to receive the body of the occupant.

[0003] The gas generator is incorporated into this airbag device, and when a vehicle collides or the like, the igniter is ignited by energization from the control unit, and the gas generating agent is burned by the flame generated in the igniter to instantaneously generate a large amount of gas, thereby inflating and deploying the airbag.

[0004] There are gas generators with various structures, and as a gas generator that can be suitably used for side airbag devices, curtain airbag devices, knee airbag devices, etc., there is a long, substantially cylindrical cylinder-type gas generator with a relatively small outer diameter, and as a gas generator that can be suitably used for a driver's seat side airbag device, a passenger seat side airbag device, etc., there is a short, substantially cylindrical disk-type gas generator with a relatively large outer diameter.

[0005] As a document in which a cylinder-type gas generator is disclosed, for example, Japanese Unexamined Patent Application Publication No. 2017-1588 (Patent Document 1) can be cited. As a document in which a disk-type gas generator is disclosed, for example, Japanese Unexamined Patent Application Publication No. 2020-125093 (Patent Document 2) can be cited.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

[0007] In this case, if the internal pressure of the housing rises to an extremely high level compared to the internal pressure that rises during the normal operation of the gas generator, the housing may be subjected to pressure exceeding its pressure resistance, potentially leading to rupture. Therefore, from the perspective of enhancing the safety of the gas generator, it is desirable to take some measures to prevent the internal pressure from rising to a level that would cause the housing to rupture.

[0008] Therefore, the present invention has been made in view of the above-mentioned problems, and aims to provide a gas generator that is safer by suppressing excessive pressure buildup inside the housing. [Means for solving the problem]

[0009] A gas generator according to a first aspect of the present invention comprises a metal housing, a metal igniter housing, a terminal pin, and a resin part. The housing has a combustion chamber inside and is provided with an opening in part. The igniter housing houses an igniter and is positioned to face the inside of the combustion chamber. The terminal pin is connected to the igniter housing and is inserted through the opening. The resin part is for fixing the igniter housing to the housing. The igniter housing has a cup and a plug. The cup has a bottomed, substantially cylindrical shape with one end in the axial direction being an open end. The plug closes the open end, and the terminal pin is erected on it. The resin part closes the opening by filling the space between the housing in the portion defining the opening and the igniter housing. When viewed along the axial direction, the igniter housing overlaps only the opening and does not overlap the housing in the portion defining the opening.

[0010] A gas generator according to a second aspect of the present invention comprises a metal housing, a metal igniter housing, a terminal pin, and a resin part. The housing has a combustion chamber inside and is provided with an opening in part. The igniter housing houses an igniter and is positioned to face the inside of the combustion chamber. The terminal pin is connected to the igniter housing and is inserted through the opening. The resin part is for fixing the igniter housing to the housing. The igniter housing has a cup and a plug. The cup has a bottomed, substantially cylindrical shape with one end in the axial direction being an open end. The plug closes the open end, and the terminal pin is erected on it. The resin part closes the opening by being positioned to fill the space between the housing and the igniter housing in the portion that defines the opening. The housing of the portion defining the above-mentioned opening includes a first portion which does not overlap the igniter housing when viewed along the axial direction, and a second portion which overlaps the igniter housing when viewed along the axial direction, thereby supporting the igniter housing, and which begins to deform at a pressure lower than the pressure at which the first portion begins to deform due to the rise in internal pressure of the combustion chamber during abnormal operation of the gas generator.

[0011] In a gas generator according to the first and second aspects of the present invention described above, the housing may have a peripheral wall portion that is arranged substantially coaxially with the cup, has one end and the other end in the axial direction closed off, and includes a combustion chamber and a filter chamber in which a filter is arranged. In that case, a partition member may be provided inside the peripheral wall portion that divides the space inside the peripheral wall portion in the axial direction such that the combustion chamber is located on the side of the one end and the filter chamber is located on the side of the other end. In that case, the igniter housing portion may be fixed to the one end of the peripheral wall portion by the resin portion. [Effects of the Invention]

[0012] According to the present invention, a gas generator with enhanced safety can be provided by suppressing excessive pressure buildup inside the housing. [Brief explanation of the drawing]

[0013] [Figure 1] This is a schematic diagram of a cylinder-type gas generator according to Embodiment 1. [Figure 2] Figure 1 is a magnified view of the area near the ignition. [Figure 3] This is an enlarged view of the vicinity of the partition member shown in Figure 1. [Figure 4] Figure 1 is an enlarged cross-sectional view showing a detailed configuration near the ignition device. [Figure 5] Figure 4 is a schematic cross-sectional view of the holder opening as seen from the combustion chamber side. [Figure 6] Figure 1 is a schematic enlarged cross-sectional view showing the area near the igniter in a cylinder-type gas generator when the internal pressure of the housing exceeds a predetermined pressure. [Figure 7] This is a schematic enlarged cross-sectional view showing the area near the igniter in a cylindrical gas generator according to a comparative example when the internal pressure of the housing exceeds a predetermined pressure. [Figure 8] This is an enlarged cross-sectional view showing in detail the configuration near the igniter in the cylinder-type gas generator according to Embodiment 2. [Figure 9] Figure 8 is a schematic enlarged cross-sectional view showing the area near the igniter in a cylinder-type gas generator when the internal pressure of the housing exceeds a predetermined pressure. [Figure 10] This is an enlarged cross-sectional view showing in detail the configuration near the igniter in the cylinder-type gas generator according to Embodiment 3. [Figure 11] Figure 10 is a schematic cross-sectional view of the holder opening as seen from the combustion chamber side. [Figure 12] Figure 10 is a schematic enlarged cross-sectional view showing the area near the igniter in a cylinder-type gas generator when the internal pressure of the housing exceeds a predetermined pressure. [Modes for carrying out the invention]

[0014] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The following embodiments illustrate the case where the present invention is applied to a cylinder-type gas generator incorporated in a side airbag device. In the following embodiments, the same or common parts are denoted by the same reference numerals in the drawings, and the description thereof will not be repeated.

[0015] (Embodiment 1) <A. Configuration of Cylinder-Type Gas Generator> FIG. 1 is a schematic view of a cylinder-type gas generator according to Embodiment 1. FIG. 2 is an enlarged view of the vicinity of the igniter shown in FIG. 1, and more specifically, an enlarged view of the region II shown in FIG. 1. FIG. 3 is an enlarged view of the vicinity of the partition member shown in FIG. 1, and more specifically, an enlarged view of the region III shown in FIG. 1. First, the configuration of the cylinder-type gas generator 1A according to the present embodiment will be described with reference to FIGS. 1 to 3.

[0016] As shown in FIGS. 1 to 3, the cylinder-type gas generator 1A has an elongated cylindrical outer shape. The cylinder-type gas generator 1A has an elongated substantially cylindrical housing with both ends in the axial direction closed. The housing includes a housing body 10, a holder 20, a closing member 30, and a partition member 50. The outer shell of the housing is defined by the housing body 10, the holder 20, and the closing member 30. The cylinder-type gas generator 1A is incorporated in the airbag device so that no occupant is located on the extension line of the axis of the housing.

[0017] The housing contains internal components such as an igniter 40, multiple granular gas generating agents 60 (hereinafter also simply referred to as "gas generating agents 60"), an auto-ignition agent 61, an isolation member 65, a coil spring 70, and a filter 80, in addition to these, and the aforementioned partition member 50, which is also an internal component, is also arranged inside. Inside the housing are a combustion chamber S1 and a filter chamber S2. The combustion chamber S1 houses the gas generating agent 60, auto-ignition agent 61, isolation member 65, and coil spring 70, which are among the internal components mentioned above. The filter chamber S2 houses the filter 80.

[0018] The housing body 10 constitutes the peripheral wall portion 11 of the housing and is made of a long cylindrical member. The peripheral wall portion 11 has one end and the other end in the axial direction, and both of these ends constitute open ends.

[0019] The housing body 10 may be made of a metal component such as stainless steel, iron, aluminum alloy, or stainless alloy, or it may be made of a press-formed product formed into a cylindrical shape by press-working rolled steel sheet, such as SPCE. Alternatively, the housing body 10 may be made of electric resistance welded pipe, such as STKM.

[0020] In particular, when the housing body 10 is constructed from a press-formed rolled steel sheet or electric resistance welded pipe, it is possible to form the housing body 10 at a lower cost and more easily compared to using metal components such as stainless steel or iron, and to significantly reduce its weight.

[0021] The holder 20 and the closing member 30 are made of metal components such as stainless steel, iron, aluminum alloy, or stainless alloy.

[0022] As shown in Figures 1 and 2, the holder 20 is made of a substantially cylindrical member having an opening 21 that penetrates the holder 20 in a direction parallel to the axial direction of the peripheral wall 11, and is assembled to the peripheral wall 11 so as to close one of the pair of open ends of the peripheral wall 11. When viewed along the axial direction of the peripheral wall 11, the opening 21 has a circular contour (see Figure 5, which will be described later). In this embodiment, the opening 21 provided in this holder 20 corresponds to an opening provided in a part of the housing. The detailed configuration of the holder 20 will be described in detail later.

[0023] The holder 20 is fixed to the peripheral wall 11 by joining the holder 20 and the peripheral wall 11 at or near the contact point between the holder 20 and the peripheral wall 11, for example by welding, with a portion of the holder 20 inserted into the open end of the peripheral wall 11.

[0024] As a result, a welded portion 91 extending along the circumferential direction of the housing is provided at the axial end of the housing located on the open end side of the peripheral wall portion 11. The gap between the peripheral wall portion 11 and the holder 20 is filled by the welded portion 91. Therefore, the gap is sealed by the welded portion 91, making it possible to ensure airtightness in that portion. Electron beam welding, laser welding, resistance welding, etc., can be suitably used for welding the peripheral wall portion 11 and the holder 20.

[0025] Furthermore, the assembly structure of the holder 20 to the peripheral wall portion 11 is not limited to the assembly structure described above, and other assembly structures may be adopted. In that case, airtightness between the peripheral wall portion 11 and the holder 20 can be ensured by providing an O-ring or the like at an appropriate position.

[0026] As shown in Figure 1, the closure member 30 is made of a substantially disc-shaped member and is assembled to the peripheral wall portion 11 so as to close the other of the pair of open ends of the peripheral wall portion 11. In detail, the closure member 30 is inserted into the open end of the peripheral wall portion 11 so that one end face in its axial direction is pressed against the filter 80, and the closure member 30 is fixed to the peripheral wall portion 11 by joining the flange portion of the closure member 30 and the peripheral wall portion 11 at or near the contact point between them, for example, by welding.

[0027] As a result, a welded portion 92 extending along the circumferential direction of the housing is provided at the axial end of the housing located on the open end side of the peripheral wall portion 11. The gap between the peripheral wall portion 11 and the closing member 30 is filled by the welded portion 92. Therefore, the gap is sealed by the welded portion 92, making it possible to ensure airtightness in that portion. Electron beam welding, laser welding, resistance welding, etc., can be suitably used for welding the peripheral wall portion 11 and the closing member 30.

[0028] Furthermore, the assembly structure of the closing member 30 to the peripheral wall portion 11 is not limited to the assembly structure described above, and other assembly structures may be adopted. Also, the peripheral wall portion 11 and the closing member 30 may not be separate components, but rather formed from a single component having a bottomed cylindrical shape.

[0029] As shown in Figures 1 and 2, the igniter 40 is fixed to one axial end of the peripheral wall portion 11 by being supported by the holder 20. The igniter 40 is for burning the gas generating agent 60 and is positioned to face the inside of the combustion chamber S1. The detailed configuration of the igniter 40 will be described in detail later.

[0030] As shown in Figures 1 and 3, partition members 50 are positioned at predetermined locations within the internal space of the housing. The partition members 50 are members that partition the internal space of the housing in the axial direction of the peripheral wall 11, such that the combustion chamber S1 is located at one end of the peripheral wall 11 in the axial direction and the filter chamber S2 is located at the other end of the peripheral wall 11 in the axial direction.

[0031] The partition member 50 has a bottomed cylindrical shape and is made of a metal material such as stainless steel, iron or steel, aluminum alloy, or stainless alloy.

[0032] The partition member 50 has a substantially cylindrical annular plate portion 51 that extends along the inner circumferential surface of the peripheral wall portion 11, and a substantially flat plate portion 52 that closes one end of the annular plate portion 51 in the axial direction. The annular plate portion 51 is erected from the periphery of the flat plate portion 52 toward the combustion chamber S1 side. The partition member 50 is arranged such that the main surface of the flat plate portion 52 on the filter chamber S2 side abuts against the filter 80.

[0033] A score 52a is provided on the main surface of the flat plate portion 52 that contacts the filter 80. The score 52a is intended to cause the flat plate portion 52 to break as the internal pressure of the combustion chamber S1 increases due to the combustion of the gas generating agent 60 during the operation of the cylinder-type gas generator 1A, thereby forming an opening that connects the combustion chamber S1 and the filter chamber S2. The score 52a is composed of, for example, a plurality of grooves arranged radially and intersecting each other.

[0034] The partition member 50 is assembled by being inserted into the peripheral wall portion 11 and then joined to the peripheral wall portion 11. More specifically, the partition member 50 is press-fitted into the interior of the peripheral wall portion 11, and is fixed to the peripheral wall portion 11 by welding or the like at the contact point between the annular plate portion 51 of the partition member 50 and the peripheral wall portion 11 or in its vicinity.

[0035] As a result, the housing corresponding to the portion in which the partition member 50 is inserted is provided with a welded portion 93 that extends along the circumferential direction of the housing. The gap between the peripheral wall portion 11 and the partition member 50 is filled by the welded portion 93. Therefore, the gap is sealed by the welded portion 93, making it possible to ensure airtightness in that portion. Electron beam welding, laser welding, resistance welding, etc., can be suitably used for welding the peripheral wall portion 11 and the partition member 50.

[0036] Furthermore, the assembly structure of the partition member 50 to the peripheral wall portion 11 is not limited to the press-fit and welding assembly structure described above, and other assembly structures may be adopted. In that case, airtightness between the peripheral wall portion 11 and the partition member 50 can be ensured by providing O-rings or the like at appropriate positions.

[0037] As shown in Figures 1 and 2, in the space inside the housing, the space sandwiched between the holder 20 and the partition member 50 (i.e., the combustion chamber S1) contains a plurality of granular gas generating agents 60 and a coil spring 70.

[0038] The gas generating agent 60 is an agent that generates gas by being ignited and burned by the thermal particles produced when the igniter 40 is activated. It is preferable to use a non-azide gas generating agent 60. The gas generating agent 60 is generally composed of a molded body containing a fuel, an oxidizer, and an additive.

[0039] As fuels, for example, triazole derivatives, tetrazole derivatives, guanidine derivatives, azodicarbonamide derivatives, hydrazine derivatives, etc., or combinations thereof can be used. In particular, for example, nitroguanidine, guanidine nitrate, cyanoguanidine, 5-aminotetrazole, etc., are preferably used.

[0040] Suitable oxidizing agents include basic metal salts such as basic copper nitrate and 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.

[0041] Examples of additives include binders, slag-forming agents, and combustion modifiers. Suitable binders include organic binders such as metal salts of carboxymethylcellulose and stearates, and inorganic binders such as synthetic hydrotalcite and acid clay. Suitable slag-forming agents include silicon nitride, silica, and acid clay. Suitable combustion modifiers include metal oxides, ferrosilicon, activated carbon, and graphite.

[0042] The molded body of the gas generating agent 60 can take various shapes, such as granular, pelletized, cylindrical, or disc-shaped forms. For cylindrical forms, perforated molded bodies with through holes inside (e.g., single-hole cylindrical or multi-hole cylindrical shapes) are also used. These shapes are preferably selected appropriately according to the specifications of the airbag device into which the cylinder-type gas generator 1A is incorporated. For example, it is preferable to select an optimal shape according to the specifications, such as selecting a shape in which the gas generation rate changes over time during the combustion of the gas generating agent 60. In addition to the shape of the gas generating agent 60, it is also preferable to appropriately select the size and filling amount of the molded body, taking into consideration the linear combustion rate and pressure index of the gas generating agent 60.

[0043] The coil spring 70 is provided to prevent the gas generating agent 60, which is made of a molded body, from being crushed by vibration or the like, and is constructed by winding a metal wire in a spiral shape.

[0044] The coil spring 70 has a spring portion 71 and a pressing portion 72. The spring portion 71 is positioned so that one end is in contact with the holder 20 and / or the igniter 40. The other end of the spring portion 71 has a pressing portion 72. The pressing portion 72 is made up of, for example, metal wires arranged substantially parallel to each other at a predetermined interval, and is in contact with the gas generating agent 60.

[0045] As a result, the gas generating agent 60 is elastically biased toward the partition member 50 by the coil spring 70, preventing it from moving within the housing.

[0046] The end of the coil spring 70 on the holder 20 side surrounds the ignition part 42 of the ignition device 40 so as to be in contact with the ignition part 42 of the ignition device 40, or positioned close to the ignition part 42 of the ignition device 40 with a predetermined clearance. With this configuration, when the ignition device 40 is operated and the cup body 42c of the ignition part 42 opens, the degree to which the cup body 42c opens is restricted by the coil spring 70. The ignition part 42 will be described in detail later.

[0047] By appropriately regulating the opening of the cup body 42c, the direction of travel of the heat particles generated at the ignition unit 42 is narrowed in the axial direction of the peripheral wall 11, thereby efficiently guiding the heat particles to the gas generating agent 60. In other words, the coil spring 70 surrounding the ignition unit 42 also has the function of giving directionality to the direction of travel of the heat particles generated at the ignition unit 42.

[0048] As shown in Figures 1 and 3, an auto-ignition agent 61 and an isolation member 65 are further arranged in the combustion chamber S1.

[0049] The combustion chamber S1 located between the flat plate portion 52 of the partition member 50 and the gas generating agent 60 contains the auto-ignition agent 61. The auto-ignition agent 61 consists of pellets molded into a flattened, approximately cylindrical shape. However, the shape of the auto-ignition agent 61 is not particularly limited to a flattened, approximately cylindrical shape and can be changed in various ways.

[0050] The auto-ignition agent 61 is positioned so as to abut the main surface of the flat plate portion 52 of the partition member 50 on the side opposite to the side facing the filter chamber S2. In this embodiment, the auto-ignition agent 61 is positioned at the radial center of the peripheral wall portion 11.

[0051] The auto-ignition agent 61 is an agent that can ignite automatically without the operation of the igniter 40. More specifically, the auto-ignition agent 61 spontaneously ignites at a lower temperature than the gas generating agent 60, and is intended to prevent abnormal operation from being induced even if the cylinder-type gas generator 1A is heated from the outside in the event of a fire or other incident in a vehicle equipped with an airbag system that incorporates the cylinder-type gas generator 1A.

[0052] The combustion chamber S1 is provided with an isolation member 65 that separates the gas generating agent 60 and the auto-ignition agent 61. The isolation member 65 is a component that aims to extend the lifespan of the gas generating agent 60 and the auto-ignition agent 61 by separating them so that they do not come into direct contact with each other. This is because the auto-ignition agent 61 has a composition similar to that of the gas generating agent 60, and depending on the combination of their compositions, if the gas generating agent 60 and the auto-ignition agent 61 are placed in contact with each other, it may cause aging deterioration in which the composition of each is gradually changed.

[0053] The isolation member 65 has a bottomed cylindrical shape and includes a substantially cylindrical annular wall portion 66 that extends along the inner circumferential surface of the annular plate portion 51 of the partition member 50, and a substantially flat bottom wall portion 67 that closes one end of the annular wall portion 66 in the axial direction. The annular wall portion 66 is erected from the periphery of the bottom wall portion 67 toward the combustion chamber S1 side. The isolation member 65 is press-fitted and fixed to the partition member 50 such that the main surface of the bottom wall portion 67 on the filter chamber S2 side abuts against the auto-ignition agent 61, and the outer circumferential surface of the annular wall portion 66 abuts against the inner circumferential surface of the annular plate portion 51 of the partition member 50.

[0054] The isolation member 65 is preferably made of a metal press-formed product, and preferably made of a brass member that will not break or melt even when the gas generating agent 60 is burned. However, the isolation member 65 does not necessarily have to be made of brass, and may be made of stainless steel, iron, iron, aluminum, aluminum alloy, etc.

[0055] The auto-ignition agent 61 is contained within the space defined by the partition member 50 and the isolation member 65, sandwiched in the axial direction of the peripheral wall portion 11 by the flat plate portion 52 and the bottom wall portion 67.

[0056] As the auto-ignition agent 61 is in contact with both the partition member 50 and the isolation member 65, the auto-ignition agent 61 makes thermal contact with the peripheral wall 11 via the partition member 50, which is a metal member, and / or the isolation member 65, which is a metal member, through the shortest possible path. Therefore, in the event of a fire in a vehicle or the like, the timing of the auto-ignition operation, which is initiated by the automatic ignition of the auto-ignition agent 61, is accelerated, and as a result, the temperature of the gas generating agent 60 when the auto-ignition operation occurs can be kept relatively low. Consequently, it becomes possible to effectively suppress the rise in internal pressure of the housing during auto-ignition operation.

[0057] As shown in Figures 1 and 3, a filter 80 is placed in the space within the housing that is sandwiched between the closing member 30 and the partition member 50 (i.e., the filter chamber S2). The filter 80 consists of a cylindrical member having a hollow portion 81 that extends in a direction parallel to the axial direction of the housing body 10. One end face of the filter 80 in the axial direction is in contact with the closing member 30, and the other end face in the axial direction is in contact with the partition member 50.

[0058] The filter 80 functions as a cooling means that cools the gas generated by the combustion of the gas generating agent 60 by removing the high-temperature heat from the gas as it passes through the filter 80, and also functions as a removal means that removes slag (residue) and other substances contained in the gas. As described above, by using a filter 80 made of a cylindrical member, the flow resistance to the gas flowing through the filter chamber S2 during operation is kept low, enabling efficient gas flow.

[0059] As the filter 80, preferably, an aggregate of metal wire materials or metal mesh materials made of stainless steel, steel, or the like can be used. Specifically, a knitted wire mesh, a plain woven wire mesh, an aggregate of crimped woven metal wire materials, or those obtained by pressing these with a press can be used.

[0060] Also, as the filter 80, a wound perforated metal plate or the like can be used. In this case, as the perforated metal plate, for example, expanded metal formed by making slits in a metal plate in a staggered pattern and expanding this to form holes and processing it into a mesh shape, or hook metal formed by punching holes in a metal plate and flattening it by crushing burrs generated at the peripheral edges of the holes during that process can be used.

[0061] The filter 80 is arranged apart from the peripheral wall portion 11 of the portion defining the filter chamber S2 so that a gap portion 82 of a predetermined size is formed between the filter 80 and the peripheral wall portion 11. By providing this gap portion 82, the gas generated by the combustion of the gas generating agent 60 can pass through substantially the entire area in the filter 80, and the utilization efficiency of the filter 80 can be enhanced.

[0062] A plurality of gas ejection ports 12 are provided in the peripheral wall portion 11 of the portion defining the filter chamber S2 along the circumferential direction and the axial direction. These plurality of gas ejection ports 12 are for leading the gas after passing through the filter 80 to the outside of the housing.

[0063] <B. Detailed Configuration of Holder and Igniter> Figure 4 is an enlarged cross-sectional view showing in detail the configuration near the igniter shown in Figure 1. Figure 5 is a schematic cross-sectional view of the holder opening shown in Figure 4, viewed from the combustion chamber side. Next, the detailed configuration of the holder 20 and igniter 40 provided in the cylinder-type gas generator 1A according to this embodiment will be described with reference to Figures 4 and 5 and the aforementioned Figure 2. Note that the coil spring 70 is not shown in Figure 4 (the same applies to Figures 6 to 10 and 12, which will be described later). Also, in Figure 5, the line obtained when the outer edge of the metal cup 42c1, which will be described later, is projected along its axial direction onto the opening 21 of the holder 20 is shown as a dashed line (the same applies to Figure 11, which will be described later).

[0064] As shown in Figures 2, 4, and 5, the igniter 40 has a base 41, an ignition part 42, and a pair of terminal pins 43.

[0065] The base portion 41 is the part that holds the ignition unit 42 and the pair of terminal pins 43, and is also the part that is fixed to the holder 20. The base portion 41 has a substantially cylindrical shape with a recess at one end that can receive the ignition unit 42. The base portion 41 is formed by injection molding (more specifically, insert molding) using a mold. The base portion 41 holds the pair of terminal pins 43 by inserting them through it. The material of the base portion 41 is not particularly limited, and it is possible to use not only thermosetting resins such as epoxy resin, but also thermoplastic resins such as polybutylene terephthalate resin, polyethylene terephthalate resin, polyamide resin (for example, nylon 6 or nylon 66), polypropylene sulfide resin, and polypropylene oxide resin. In this embodiment, the base portion 41 corresponds to the resin part.

[0066] The ignition unit 42 includes an igniter 42a, a metal embolus 42b, and a cup body 42c. The cup body 42c includes a metal cup 42c1 and a resin cup 42c2. Both the metal cup 42c1 and the resin cup 42c2 have a bottomed, roughly cylindrical shape with one end in the axial direction being open. The resin cup 42c2 is placed on top of the metal cup 42c1 so as to cover it. In this embodiment, the metal cup 42c1 corresponds to the cup.

[0067] The igniter 42a and embolus 42b described above are arranged in the space inside the metal cup 42c1. In detail, the embolus 42b is positioned to close the open end of the metal cup 42c1. The igniter 42a is housed in the space defined by the embolus 42b and the metal cup 42c1. A pair of terminal pins 43 are erected from the embolus 42b toward the side opposite to the igniter 42a. In this embodiment, the metal cup 42c1 and the embolus 42b constitute the igniter housing 45. Furthermore, the outer edge of the igniter housing 45, when viewed along the axial direction of the metal cup 42c1, is defined by the metal cup 42c1.

[0068] A flange is provided at the open end of the resin cup 42c2, and a base portion 41 is formed to surround this flange portion. This prevents the cup body 42c from falling off the base portion 41, and the cup body 42c is fixed to the base portion 41.

[0069] A resistor (bridge wire) is mounted inside the space defined by the embolus 42b and the metal cup 42c1 so as to be connected to a pair of terminal pins 43, and the space is filled with igniter 42a so as to surround or in contact with the resistor. A propellant charge may be loaded into the space as needed.

[0070] Generally, nichrome wire or resistance wires made of alloys containing platinum and tungsten are used as resistors. Generally, ZPP (zirconium-potassium perchlorate), ZWPP (zirconium-tungsten-potassium perchlorate), lead tricinate, etc. are used as ignition agents. Compositions consisting of metal powder / oxidizing agents such as B / KNO3, B / NaNO3, Sr(NO3)2, etc., compositions consisting of titanium hydride / potassium perchlorate, compositions consisting of B / 5-aminotetrazole / potassium nitrate / molybdenum trioxide, etc. are used as propellants. In addition to the ignition agent, an auto-ignition agent such as 3-nitro-1,2,4-triazole-5-one, guanidine nitrate, sodium nitrate, graphite, etc. may be loaded into the above space.

[0071] When a collision is detected, a predetermined amount of current flows through the resistor via the terminal pin 43. This generates Joule heat in the resistor, causing the igniter to start burning. The high-temperature thermal particles produced by the combustion rupture the cup body 42c containing the igniter. The time from when the current flows through the resistor until the igniter 40 is activated is generally 2 milliseconds or less when a nichrome wire is used for the resistor.

[0072] As described above, the holder 20 is a substantially cylindrical member with an opening 21 that penetrates the holder 20 in a direction parallel to the axial direction of the peripheral wall portion 11, and the igniter 40 is fixed to this holder 20.

[0073] In detail, the holder 20 has a crimping portion 22 at its axial end facing the combustion chamber S1 for crimping and fixing the igniter 40. The base portion 41 is clamped by the holder 20 when the crimping portion 22 is crimped while the base portion 41 and terminal pin 43 are inserted through the opening 21 and pressed against the portion of the holder 20 that defines the opening 21.

[0074] As a result, the base portion 41 is positioned to fill the space between the holder 20 and the ignition charge housing 45 in the portion that defines the opening 21, thereby closing the opening 21. Consequently, the igniter 40, including the ignition charge housing 45, is fixed to the housing (more specifically, the holder 20).

[0075] As a result, the igniter 40 is assembled to the holder 20 such that the igniter housing 45 faces the inside of the combustion chamber S1. In this embodiment, the igniter 40 is fixed to the holder 20 such that the cup body 42c is positioned substantially coaxially with the peripheral wall portion 11.

[0076] When the igniter 40 is operated, the ignition charge 42a is ignited, causing a crack in the cup body 42c, and the cup body 42c opens as a result of this crack. The assembly structure of the igniter 40 is not limited to the assembly structure using the crimped portion 22 described above, and other assembly structures may be adopted.

[0077] A sealing member 44, such as an O-ring, is interposed between the holder 20 and the base 41. The gap between the holder 20 and the igniter 40 is filled by the sealing member 44, thereby sealing the gap. This configuration ensures airtightness in that area.

[0078] A recess 23 is provided at the axial end of the holder 20 that is exposed to the outside, continuous with the opening 21 described above. The recess 23 forms a female connector that receives a male connector (not shown) of a harness for connecting the igniter 40 and a control unit (not shown). Terminal pins 43 are exposed and located within the recess 23. When the male connector is inserted into the recess 23, electrical conductivity is achieved between the core wires of the harness and the terminal pins 43.

[0079] Here, as shown in FIGS. 4 and 5, in the present embodiment, the outer diameter D1 of the metal cup 42c1 is configured to be smaller than the diameter D2 of the opening 21 of the holder 20. Further, the metal cup 42c1 is arranged such that its axis passes through the center of the opening 21. Therefore, when viewed along the axial direction of the metal cup 42c1, the ignition charge housing portion 45 including the metal cup 42c1 and the plug 42b overlaps only the opening 21 without overlapping the portion of the holder 20 that defines the opening 21. By configuring in this way, the excessive pressure inside the housing is suppressed, and this point will be described in detail later.

[0080] <C. Operation of the Cylinder-Type Gas Generator> Next, referring to FIG. 1, the operation during the operation of the cylinder-type gas generator 1A according to the present embodiment will be described.

[0081] Referring to FIG. 1, when a vehicle equipped with the cylinder-type gas generator 1A according to the present embodiment collides, the collision is detected by a collision detection means provided separately in the vehicle, and based on this, the igniter 40 is activated by energization from a control unit provided separately in the vehicle.

[0082] When the igniter 40 is activated, the pressure inside the ignition portion 42 (more specifically, the pressure inside the ignition charge housing portion 45) rises due to the combustion of the ignition charge or, in addition to this, the primer charge, and as a result, the cup body 42c of the ignition portion 42 cracks, and the hot particles generated by the combustion of the ignition charge 42a or, in addition to this, the primer charge flow out to the outside of the ignition portion 42. The hot particles that reach the gas generant 60 burn the gas generant 60. As a result, a large amount of gas is generated in the combustion chamber S1.

[0083] Along with this, the pressure in the combustion chamber S1 rises, and when the internal pressure of the combustion chamber S1 reaches a predetermined pressure, a break occurs in the portion of the partition member 50 where the score 52a is provided. As a result, an opening is formed in the partition member 50 at the portion facing the hollow portion 81 of the filter 80, and the combustion chamber S1 and the filter chamber S2 are in a state of being connected through the opening.

[0084] Accordingly, the gas generated in the combustion chamber S1 flows into the filter chamber S2 through the opening formed in the partition member 50. The gas flowing into the filter chamber S2 flows along the axial direction of the hollow portion 81 of the filter 80 and then changes its direction radially and flows through the inside of the filter 80. At that time, heat is taken away by the filter 80 and the gas is cooled, and slag contained in the gas is removed by the filter 80.

[0085] Then, the gas after flowing through the filter 80 is ejected to the outside of the housing through the gas ejection port 12 provided in the peripheral wall portion 11. The ejected gas is introduced into the inside of an airbag provided adjacent to the cylinder-type gas generator 1A and inflates and deploys the airbag. Incidentally, the auto-ignition agent 61 burns together during the combustion of the gas generant 60.

[0086] <D. Parentheses> As described above, in the cylinder-type gas generator 1A according to the present embodiment, when viewed along the axial direction of the metal cup 42c1, the ignition charge accommodating portion 45 including the metal cup 42c1 and the plug 42b overlaps only the opening 21 without overlapping the holder 20 of the portion defining the opening 21. By configuring in this way, excessive pressure inside the housing is suppressed. Hereinafter, this point will be described in detail while making a comparison with the cylinder-type gas generator 1X according to a comparative example. FIG. 6 is an enlarged cross-sectional view schematically showing a state near the igniter when the internal pressure of the housing becomes a predetermined pressure or more in the cylinder-type gas generator according to the present embodiment. FIG. X is an enlarged cross-sectional view schematically showing a state near the igniter when the internal pressure of the housing becomes a predetermined pressure or more in the cylinder-type gas generator according to the comparative example.

[0087] As shown in Figures 6 and 7, the cylindrical gas generator 1X according to the comparative example differs from the cylindrical gas generator 1A according to this embodiment in the configuration of the holder 20X. More specifically, in the cylindrical gas generator 1X, when viewed along the axial direction of the metal cup 42c1, the ignition charge housing section 45, including the metal cup 42c1 and the embolus 42b, overlaps not only the opening 21 but also the portion of the holder 20 that defines the opening 21. More specifically, the outer diameter D1 of the metal cup 42c1 is larger than the diameter D2 of the opening 21 of the holder 20.

[0088] If the internal pressure of the housing is increased to a predetermined pressure higher than the design pressure during normal operation, a load from the inside to the outside of the housing (more specifically, a load from top to bottom in Figures 6 and 7) based on this internal pressure is applied near the igniter 40.

[0089] When this load is applied, shear failure (cracks) occurs in the base 41, which closes the opening 21 by filling the space between the holder 20 and the igniter housing 45 in the portion that defines the opening 21. This is because the mechanical strength of the resin base 41 is less than that of both the metal igniter housing 45 and the metal holder 20.

[0090] The crack that forms in the base 41 originates from the holder 20 and the ignition charge housing 45 that define the opening 21, and propagates in a direction substantially parallel to the axial direction, starting from the member located on the outside when viewed along the axial direction of the metal cup 42c1.

[0091] Therefore, in the comparative example cylinder-type gas generator 1X, as shown in Figure 7, a crack C is formed in the base 41, starting from the outer edge of the igniter housing 45 when viewed along the axial direction. Here, the holder 20 is located at the end of the crack C opposite to the inside of the housing in the axial direction. Therefore, in order for the gas inside the housing to pass through the crack C and escape to the outside of the housing (towards the recess 23), the gas must further pass through the gap between the holder 20 and the base 41. However, since this gap has a reasonable sealing ability, it is not easy to escape the gas inside the housing to the outside of the housing in this way.

[0092] In this regard, in the cylinder-type gas generator 1A according to this embodiment, as shown in Figure 6, a crack C is generated in the base 41, starting from the inner edge of the holder 20 that defines the opening 21 when viewed along the axial direction. The end of the crack C generated in this way that is opposite to the inside of the housing in the axial direction is exposed to the outside of the housing (towards the recess 23).

[0093] This allows gas inside the housing to easily escape to the outside of the housing by passing through crack C (see arrow in Figure 6). As a result, the internal pressure of the housing is effectively prevented from rising to a pressure exceeding the housing's pressure resistance.

[0094] Therefore, by configuring the gas generator as shown in the cylinder-type gas generator 1A according to this embodiment, overpressure inside the housing is suppressed, resulting in a gas generator with enhanced safety.

[0095] Furthermore, as described above, the cylinder-type gas generator 1A according to this embodiment is incorporated into the airbag system so that the occupant is not positioned on the extension of the housing's axis. Therefore, the gas inside the housing is released from the axial end of the housing in a direction away from the occupant, thus ensuring safety in this respect as well.

[0096] In the above-described embodiment, as an example of a specific configuration in which the igniter housing portion 45 overlaps only with the opening 21 and not with the holder 20 that defines the opening 21 when viewed along the axial direction of the metal cup 42c1, the case in which the outer diameter D1 of the metal cup 42c1 is smaller than the diameter D2 of the opening 21 of the holder 20 and the axis of the metal cup 42c1 passes through the center of the opening 21 was described as an example, but the specific configuration is not limited to this. As long as the above configuration is realized, the outer edge of the metal cup 42c1 and the contour of the opening 21 may be a shape other than a circle, such as a rectangle or polygon, and the metal cup 42c1 may be positioned relative to the opening 21 such that the axis of the metal cup 42c1 passes through a position offset from the center of the opening 21.

[0097] Furthermore, in the embodiment described above, the example shown is that the outer edge of the igniter housing 45, when viewed along the axial direction of the metal cup 42c1, is defined by the metal cup 42c1. However, the igniter housing 45 may be configured such that the outer edge is defined by the embolus 42b.

[0098] (Embodiment 2) Figure 8 is an enlarged cross-sectional view showing in detail the configuration near the igniter in the cylinder-type gas generator according to Embodiment 2. Figure 9 is an enlarged cross-sectional view schematically showing the area near the igniter when the internal pressure of the housing of the cylinder-type gas generator shown in Figure 8 exceeds a predetermined pressure. Hereinafter, the cylinder-type gas generator 1B according to this embodiment will be described with reference to Figures 8 and 9.

[0099] As shown in Figure 8, the cylinder-type gas generator 1B according to this embodiment differs from the cylinder-type gas generator 1A according to Embodiment 1 described above in the configuration of the igniter 40B and the holder 20B.

[0100] In detail, the igniter 40B of the cylinder-type gas generator 1B differs from the igniter 40 of the cylinder-type gas generator 1A in that it does not have a base 41.

[0101] The holder 20B is crimped and fixed to the peripheral wall portion 11 with a portion of it inserted inside so as to close the open end of the peripheral wall portion 11. A portion of the igniter 40B is positioned inside the opening 21 of the holder 20B. Between the igniter 40B and the holder 20B, there is a resin molded portion 26 that closes the opening 21 by filling the space between the holder 20B and the igniter housing portion 45 in the portion that defines the opening 21. In this embodiment, the resin molded portion 26 corresponds to the resin portion.

[0102] The resin molded portion 26 includes a surrounding portion 27, a terminal pin covering portion 28, and a female connector portion 29. The surrounding portion 27 is the part that covers the outer circumferential surface of the ignition portion 42. The terminal pin covering portion 28 is the part that covers the portion of the terminal pin 43 closest to the ignition portion 42. The female connector portion 29 is the part that surrounds the tip portion of the terminal pin 43.

[0103] The resin molded portion 26 is formed by injection molding (more specifically, insert molding) using a mold. Therefore, the resin molded portion 26 is fixed to the igniter 40B and the holder 20B in the portions that come into contact with them. In addition, the surrounding portion 27, the terminal pin covering portion 28, and the female connector portion 29 are integrally and continuously provided by insert molding.

[0104] As the raw material for the resin molded part 26, a resin material with excellent heat resistance, durability, corrosion resistance, etc. after curing is preferably selected and used. In this case, it is not limited to thermosetting resins such as epoxy resin, but it is also possible to use thermoplastic resins such as polybutylene terephthalate resin, polyethylene terephthalate resin, polyamide resin (for example, nylon 6 or nylon 66), polypropylene sulfide resin, and polypropylene oxide resin. When selecting these thermoplastic resins as raw materials, it is preferable to include glass fibers or the like as fillers in these resin materials in order to ensure the mechanical strength of the resin molded part 26 after molding. However, if sufficient mechanical strength can be ensured with thermoplastic resin alone, it is not necessary to add the fillers as described above.

[0105] A concave portion 24 is provided on the outer circumferential surface of the holder 20B (i.e., the surface facing the inner circumferential surface of the peripheral wall portion 11) so as to extend in the circumferential direction. A sealing member 25 is housed in the concave portion 24. The sealing member 25 is for hermetically sealing the gap that occurs between the peripheral wall portion 11 and the holder 20B, thereby ensuring airtightness between the outside of the cylinder-type gas generator 1B and the combustion chamber S1. In addition, the gap between the inner circumferential surface of the holder 20B and the igniter 40B is sealed by the resin molded portion 26 as described above, which also ensures airtightness between the outside of the cylinder-type gas generator 1B and the combustion chamber S1.

[0106] The outer diameter D1 of the metal cup 42c1 is smaller than the diameter D2 of the opening 21 of the holder 20B. Furthermore, the metal cup 42c1 is positioned so that its axis passes through the center of the opening 21. Therefore, when viewed along the axial direction of the metal cup 42c1, the igniter housing 45 overlaps only with the opening 21 and does not overlap with the portion of the holder 20B that defines the opening 21.

[0107] In the cylinder-type gas generator 1B configured in this way, if the internal pressure of the housing is increased to an extremely high pressure compared to the design pressure during normal operation, a crack C will form in the resin molded part 26, starting from the inner edge of the holder 20B that defines the opening 21 when viewed along the axial direction, as shown in Figure 9. The end of the crack C formed in this way, opposite to the inside of the housing in the axial direction, will be exposed to the outside of the housing (towards the recess 23). This makes it possible to easily release the gas inside the housing to the outside of the housing by passing it through the crack C.

[0108] Even with this configuration, effects similar to those described in Embodiment 1 above can be obtained, and the gas generator can be made safer by suppressing overpressure inside the housing.

[0109] (Embodiment 3) Figure 10 is an enlarged cross-sectional view showing in detail the configuration near the igniter in the cylinder-type gas generator according to Embodiment 3. Figure 11 is a schematic cross-sectional view of the opening of the holder shown in Figure 10, viewed from the combustion chamber side. Figure 12 is an enlarged cross-sectional view schematically showing the area near the igniter when the internal pressure of the housing of the cylinder-type gas generator shown in Figure 10 exceeds a predetermined pressure. Hereinafter, the cylinder-type gas generator 1C according to this embodiment will be described with reference to Figures 10 to 12.

[0110] As shown in Figures 10 and 11, the cylinder-type gas generator 1C according to this embodiment differs from the cylinder-type gas generator 1A according to Embodiment 1 described above in the configuration of the holder 20C.

[0111] In detail, in the cylinder-type gas generator 1C, the holder 20C defining the opening 21 includes a first portion 20a that does not overlap the igniter housing 45 when viewed along the axial direction of the metal cup 42c1, and a second portion 20b that protrudes radially inward from the first portion 20a of the holder 20C and supports the igniter housing 45 by overlapping it when viewed along the axial direction. In this embodiment, the holder 20C includes four first portions 20a and four second portions 20b. The first portions 20a and the second portions 20b are positioned alternately adjacent to each other in the circumferential direction of the holder 20C.

[0112] The second part 20b is configured to begin deforming at a pressure lower than the pressure at which the first part 20a begins to deform in response to the increase in internal pressure of the combustion chamber S1 during abnormal operation of the cylinder-type gas generator 1C. In this embodiment, the axial thickness dimension of the second part 20b is configured to be considerably smaller than the axial thickness dimension of the first part 20a. The abnormal operation referred to here is an operation different from the auto-ignition operation by the auto-ignition agent 61, and refers to an operation in which the internal pressure of the housing is increased to a predetermined pressure higher than the design pressure during normal operation when the cylinder-type gas generator 1C is activated.

[0113] In the cylinder-type gas generator 1C configured in this way, if the internal pressure of the housing is increased to a predetermined pressure higher than the design pressure during normal operation, as shown in Figure 12, the second part 20b first breaks by bending or flexing so that its tip faces the recess 23, or by shear failure. The deformed or broken second part 20b no longer overlaps the igniter housing 45 when viewed along the axial direction of the metal cup 42c1. Note that Figure 12 illustrates the case in which the second part 20b breaks.

[0114] Next, a crack C is formed in the base 41, starting from the inner edges of the first portion 20a and / or the second portion 20b when viewed along the axial direction of the metal cup 42c1. The end of the crack C thus formed, opposite to the axial side of the housing, is exposed to the outside of the housing.

[0115] This allows the gas inside the housing of the cylinder-type gas generator 1C to be easily released to the outside of the housing by passing it through the crack C (see arrow in Figure 12). As a result, the internal pressure of the housing is effectively prevented from rising to a pressure exceeding the housing's pressure resistance.

[0116] Even with this configuration, effects similar to those described in Embodiment 1 above can be obtained, and the gas generator can be made safer by suppressing overpressure inside the housing.

[0117] (Other forms, etc.) The characteristic configurations shown in the embodiments of the present invention described above can, of course, be combined with each other without departing from the spirit of the present invention.

[0118] Furthermore, in the embodiments of the present invention described above, the application of the present invention to a cylindrical gas generator incorporated into a side airbag system was used as an example. However, the application of the present invention is not limited to this, and it can also be applied to cylindrical gas generators incorporated into curtain airbag systems, knee airbag systems, seat cushion airbag systems, etc., as well as so-called T-shaped gas generators that have an elongated external shape similar to that of a cylindrical gas generator.

[0119] Furthermore, the present invention can also be applied to disc-type gas generators suitably incorporated into airbag systems mounted on the steering wheel of automobiles, etc., and gas generators (so-called micro gas generators) suitably incorporated into seat belt systems equipped with pretensioners.

[0120] Thus, the embodiments disclosed herein are illustrative in all respects and not restrictive. The technical scope of the present invention is defined by the claims and includes all modifications within the meaning and scope of equivalents to the claims. [Explanation of Symbols]

[0121] 1A~1C,1X Cylinder-type gas generator, 10 Housing body, 11 Peripheral wall, 12 Gas outlet, 20,20B,20C,20X Holder, 20a First part, 20b Second part, 21 Opening, 22 Crimped part, 23 Recess, 24 Concave part, 25 Sealing member, 26 Resin molded part, 27 Surrounding part, 28 Terminal pin covering part, 29 Female connector part, 30 Closure member, 40,40B Ignitioner, 41 Base, 42 Ignition part, 42a Ignition charge, 42b Embolizer, 42c Cup body, 42c1 Metal cup, 42c2 Resin cup, 43 Terminal pin, 44 Sealing member, 45 Ignition charge housing part, 50 Partition member, 51 Annular plate part, 52 Flat plate part, 52a Score, 60 Gas generating agent, 61 Auto ignition agent, 65 Isolation member, 66 Annular wall section, 67 Bottom wall section, 70 Coil spring, 71 Spring section, 72 Pressing section, 80 Filter, 81 Hollow section, 82 Gap section, 91-93 Welded section, C Crack, S1 Combustion chamber, S2 Filter chamber.

Claims

1. A metal housing having a combustion chamber inside and an opening in part, A metal igniter housing section, which contains the igniter and is positioned to face the inside of the combustion chamber, A terminal pin connected to the igniter housing and inserted through the opening, The igniter containment section is provided with a resin part for fixing it to the housing, The igniter containment section comprises a cup having a bottomed, roughly cylindrical shape with one end in the axial direction being open, and a plug that closes the open end and on which the terminal pin is erected. The resin portion closes the opening by positioning itself to fill the space between the housing that defines the opening and the ignition charge housing portion. The igniter housing is a gas generator in which, when viewed along the axial direction, it overlaps only the opening and does not overlap the portion of the housing that defines the opening.

2. A metal housing having a combustion chamber inside and an opening in part, A metal igniter housing section, which contains the igniter and is positioned to face the inside of the combustion chamber, A terminal pin connected to the igniter housing and inserted through the opening, A gas generator comprising a resin part for fixing the igniter housing to the housing, The igniter containment section comprises a cup having a bottomed, roughly cylindrical shape with one end in the axial direction being open, and a plug that closes the open end and on which the terminal pin is erected. The resin portion closes the opening by positioning itself to fill the space between the housing that defines the opening and the ignition charge housing portion. A gas generator wherein the housing of the portion defining the opening includes a first portion that does not overlap the igniter housing when viewed along the axial direction, and a second portion that overlaps the igniter housing when viewed along the axial direction, thereby supporting the igniter housing, and that begins to deform at a pressure lower than the pressure at which the first portion begins to deform due to an increase in the internal pressure of the combustion chamber during abnormal operation of the gas generator.

3. The housing is positioned substantially coaxially with the cup, has one end and the other end in the axial direction closed, and has a peripheral wall portion that includes the combustion chamber and the filter chamber in which the filter is located. A partition member is provided inside the peripheral wall portion, which divides the space inside the peripheral wall portion in the axial direction such that the combustion chamber is located on one end side and the filter chamber is located on the other end side. The gas generator according to claim 1 or 2, wherein the ignition charge housing is fixed to one end of the peripheral wall by the resin portion.

Images