JP7486320B2 - Gas generator and method for assembling gas generator - Google Patents

Description

The present invention relates to a gas generator that generates combustion gas by burning a gas generating agent through activation of an ignition unit, and a method for assembling a gas generator.

Conventionally, gas generators have been widely used in which a gas generating agent is filled into a combustion chamber formed in a housing, the gas generating agent is burned by an igniter to generate combustion gas, and the combustion gas is discharged to the outside from a gas exhaust hole provided in the housing. In such gas generators, a cylindrical filter may be disposed between the combustion chamber and the gas exhaust hole to cool the generated combustion gas and collect residue. Both axial ends of the filter are supported in contact within the housing so that all of the combustion gas passes through the filter.

In this regard, Patent Documents 1 and 2 disclose gas generators equipped with a structure for suppressing the so-called "short pass," in which part of the combustion gas reaches the gas exhaust hole without passing through the filter. The gas generator disclosed in Patent Document 1 suppresses short passes by attaching a fixture to the end face of the filter to fix the end face of the filter to the housing. In addition, the gas generator disclosed in Patent Document 2 suppresses short passes by forming a bent part in the part of the filter that contacts the housing and pressing the end face of the filter against the housing using the elastic force of the bent part.

International Publication No. 2002/083464 JP 2010-234843 A

However, the above-mentioned technology is not effective enough in suppressing short passes, and there is a demand for technology that can suppress short passes more effectively.

The technology disclosed herein has been developed in light of the above-mentioned circumstances, and its purpose is to provide technology that can effectively suppress short passes in gas generators.

In order to solve the above problems, the technology of the present disclosure employs the following configuration: That is, the technology of the present disclosure includes a combustion chamber in which an ignition unit and a gas generating agent that burns upon activation of the ignition unit are disposed, a housing that defines the combustion chamber, the housing including a cylindrical peripheral wall portion, a first wall portion provided on one end side of the peripheral wall portion, and a second wall portion provided on the other end side of the peripheral wall portion, the peripheral wall portion being formed with a gas discharge hole that communicates the combustion chamber with the outside of the housing, and a cylindrically formed filter that is disposed between the gas generating agent and the gas discharge hole in the combustion chamber so as to surround the gas generating agent, and has one axial end face that faces the housing on the side of the first wall portion. a filter supported by a housing having a first end face and the other end face supported by the housing on the side of the second wall portion, wherein a support end face which is at least one of both axial end faces of the filter is supported by the housing with a first portion which is a part of the support end face in contact with the housing and pressing against the housing, and with a second portion which is a portion of the support end face excluding the first portion being spaced apart from the housing, and a contact state between the first portion of the support end face and the housing is formed in a ring shape along the circumferential direction of the filter.

In the gas generator of the present disclosure configured as described above, the support end face is supported by the housing at the first portion, and the first portion presses against the housing, so that the load is concentrated at the first portion. Therefore, the first portion of the support end face contacts the housing more strongly than if the entire support end face was supported by the housing. In addition, by forming the contact state between the first portion and the housing in an annular shape along the circumferential direction of the filter, no gap is formed between the support end face and the housing that would allow the combustion gas to pass from the inner surface side to the outer surface side of the filter. As a result, the gas generator of the present disclosure can effectively suppress short passes.

Furthermore, in the gas generator of the present disclosure, the support portion that supports the support end surface in the housing may be inclined so as to decrease in diameter as it moves away from the filter in the axial direction of the filter, and the support end surface may be supported by the housing with its outer peripheral edge as the first portion.

By inclining the support portion as described above, the support end surface can be supported by its outer periphery on the housing, and the outer periphery of the support end surface can be brought into strong contact with the housing.

In the gas generator of the present disclosure, the support end surface may have a protruding portion that is an annular portion that protrudes in the axial direction of the filter further than other portions of the support end surface, and the protruding portion may be supported by the housing as the first portion.

By forming the above-mentioned protrusion on the support end surface, the support end surface can be supported on the housing by the protrusion, and the protrusion can be brought into strong contact with the housing.

Furthermore, in the gas generator of the present disclosure, the ignition unit is fixed to the second wall portion, at least the other end face of both end faces of the filter is the support end face, the peripheral wall portion includes a cylindrical large diameter portion located on the side of the first wall portion and in which the gas discharge hole is formed, a cylindrical small diameter portion located on the side of the second wall portion and formed with a smaller diameter than the large diameter portion, and an annular connecting portion connecting the large diameter portion and the small diameter portion, and the supporting portion that supports the other end face of the filter in the housing may be included in the connecting portion.

In a gas generator, since the combustion gas flows toward the gas exhaust hole, most of the combustion gas passing through the filter passes through the portion of the filter near the gas exhaust hole, and the amount of combustion gas passing through the portion farther from the gas exhaust hole tends to be smaller. Therefore, in a gas generator in which a gas exhaust hole is formed on the first wall side of the peripheral wall, if the filter is provided from the first wall to the second wall, the portion of the filter near the second wall farther from the gas exhaust hole is a portion through which not much combustion gas passes and does not contribute much to cooling and filtering of the combustion gas. In contrast, in the gas generator of the present disclosure, the support portion that supports the other end face of the filter is included in the connection portion located between the first wall and the second wall in the axial direction of the peripheral wall. In other words, the filter does not extend to the vicinity of the second wall through which not much combustion gas passes. Therefore, according to such a gas generator, the filter can be used more efficiently than when the filter is provided from the first wall to the second wall. In other words, the filter can be made compact while still providing sufficient cooling and filtering capabilities for the combustion gas, which contributes to reducing the weight and cost of the filter.

Furthermore, in the gas generator of the present disclosure, the other end face of the filter may be supported by the housing such that a groove opening radially inward of the filter is formed between the second portion and the connection portion.

By forming grooves that open radially inward on the filter, combustion gas residue can be captured in the grooves as the combustion gas flows toward the gas exhaust hole. This improves the combustion residue capture performance.

Furthermore, in the above gas generator, the inner circumferential surface of the filter may be located radially inward of the small diameter portion relative to the inner circumferential surface of the small diameter portion.

As a result, the other end face of the filter protrudes radially inward beyond the small diameter portion of the peripheral wall, making it easier for combustion gas residue to be captured by the other end face of the filter and the grooves. In other words, the other end face of the filter and the grooves can be used more effectively to collect combustion gas residue.

Furthermore, in the gas generator of the present disclosure, a cylindrical inner cylinder member is disposed in the combustion chamber so as to surround the ignition unit, so that a transfer chamber containing a transfer charge that burns when the ignition unit is activated to burn the gas generating agent is formed between the ignition unit and the inner cylinder member, and a communication hole is formed in the inner cylinder member to communicate the inside and outside of the transfer chamber at least when the ignition unit is activated, and the communication hole may be located between the second wall portion and the other end face of the filter in the axial direction of the filter.

The gas generating agent is ignited by the combustion gas of the transfer charge that is ejected from the communication hole. Therefore, by positioning the communication hole between the second wall portion and the other end face of the filter, the gas generating agent in the combustion chamber that is located between the second wall portion and the other end face of the filter burns first. This creates a flow of combustion gas so that the combustion gas of the gas generating agent flows into the groove. As a result, it is possible to easily collect the combustion gas residue.

In the gas generator of the present disclosure, both axial end faces of the filter may be the support end faces.

In other words, both one and the other end faces of the filter may be supported by the housing at their respective portions, and the contact state with the housing may be formed in an annular shape along the circumferential direction of the filter. This prevents the formation of gaps between the housing and both end faces of the filter, and more effectively suppresses short-passing.

The technology of the present disclosure can also be seen from the aspect of a method of assembling a gas generator. That is, the technology of the present disclosure includes a combustion chamber in which an ignition unit and a gas generating agent that burns upon activation of the ignition unit are disposed, a housing that defines the combustion chamber, the housing including a cylindrical peripheral wall portion, a first wall portion provided on one end side of the peripheral wall portion, and a second wall portion provided on the other end side of the peripheral wall portion, the peripheral wall portion being formed with a gas exhaust hole that communicates the combustion chamber with the outside of the housing, and a cylindrical filter that is disposed between the gas generating agent and the gas exhaust hole in the combustion chamber so as to surround the gas generating agent, one axial end face of the filter being supported by the housing on the side of the first wall portion and the other axial end face being supported by the housing on the side of the second wall portion. A method for assembling a gas generator comprising the steps of: preparing a housing part that constitutes a part of the housing in the gas generator and supports a support end face that is at least one of both axial end faces of the filter; and preparing the filter; and assembling the filter to the housing part such that a first portion that is a part of the support end face contacts the housing and presses the housing, and a second portion that is a portion other than the first portion is spaced apart from the housing, and such that the contact state between the first portion of the support end face and the housing is formed in a ring shape along the circumferential direction of the filter.

Furthermore, in the assembly method of the present disclosure, the support portion that supports the support end surface in the housing part is inclined so as to reduce in diameter as it moves away from the filter in the axial direction of the filter in the gas generator, and when assembling the filter to the housing part, the filter may be assembled to the housing part such that the support end surface is supported by the housing with the outer circumferential edge of the support end surface as the first portion, and the contact state between the outer circumferential edge of the support end surface and the housing is formed in a ring shape along the circumferential direction of the filter.

In addition, in the assembly method disclosed herein, the support end surface may have a protruding portion that protrudes further along the axial direction of the filter than other portions of the support end surface, and when assembling the filter to the housing part, the support end surface may be supported by the housing with the protruding portion as the first portion, and the filter may be assembled to the housing part such that the contact state between the protruding portion and the housing is formed in a ring shape along the circumferential direction of the filter.

According to the present disclosure, short-passing of combustion gas can be more effectively suppressed in a gas generator equipped with a filter.

1 is an axial cross-sectional view of a gas generator according to a first embodiment. FIG. 2 is an enlarged view of the vicinity of a contact point between a lower end surface of a filter and an annular wall portion of a housing in FIG. 1 . 4 is an end view of a filter in the gas generator according to the first embodiment, viewed from a lower end surface side. FIG. 4 is a flowchart of a method for assembling the gas generator according to the first embodiment. FIG. 1 is a diagram (1) for explaining a process of assembling a filter according to the first embodiment. FIG. 11 is a diagram (2) for explaining the process of assembling the filter according to the first embodiment. 1 is an axial cross-sectional view of a gas generator according to a first modified example of the first embodiment. FIG. 11 is an axial cross-sectional view of a gas generator according to a second modification of the first embodiment. FIG. 13 is an axial cross-sectional view of a gas generator according to a third modification of the first embodiment. FIG. FIG. 11 is an axial cross-sectional view of a gas generator according to a second embodiment. FIG. 11 is an end view of a filter in a gas generator according to a second embodiment, as viewed from a lower end surface side. 12A and 12B are views for explaining an example of a method for manufacturing a filter according to the second embodiment. FIG. 11 is an axial cross-sectional view of a gas generator according to a third embodiment. 13A and 13B are diagrams showing modified examples of filter support.

The gas generator according to the embodiment of the present disclosure will be described below with reference to the drawings. Note that each configuration and their combinations in each embodiment are merely examples, and addition, omission, substitution, and other modifications of configurations are possible as appropriate within the scope of the present invention. The present invention is not limited to the embodiments, but is limited only by the claims.

<Embodiment 1>
Fig. 1 is an axial cross-sectional view of a gas generator 100 according to embodiment 1. Fig. 1 shows a state before activation of the gas generator 100. The gas generator 100 is a gas generator for an airbag used, for example, in an airbag.

[overall structure]
As shown in FIG. 1, the gas generator 100 includes an ignition device 4, an inner cylinder member 5, a filter 6, a transfer charge 110, a gas generating agent 120, and a housing 1 that accommodates these. The gas generator 100 is configured as a so-called single-type gas generator that includes only one ignition device. The gas generator 100 is configured to burn the gas generating agent 120 by activating an igniter 41 included in the ignition device 4, and to discharge the combustion gas, which is a combustion product, from a gas exhaust hole 11 formed in the housing 1. Each component of the gas generator 100 will be described below. In this specification, for convenience, the activation of an igniter included in the ignition device (ignition section) may be expressed as "the gas generator is activated" or "the ignition device (ignition section) is activated."

[housing]
The housing 1 is a member that defines a combustion chamber 10, which is a space in which the ignition device 4, the inner cylinder member 5, the filter 6, the transfer charge 110, and the gas generating agent 120 are disposed. The housing 1 is formed into a short cylindrical shape with both axial ends closed by joining an upper shell 2 and a lower shell 3, each of which is made of metal and formed into a substantially cylindrical shape with a bottom, with their open ends facing each other. Here, the direction along the axial direction of the housing 1 is defined as the up-down direction of the gas generator 100, with the upper shell 2 side (i.e., the upper side in FIG. 1) being the upper side of the gas generator 100 and the lower shell 3 side (i.e., the lower side in FIG. 1) being the lower side of the gas generator 100.

The upper shell 2 is a part that constitutes a part of the housing 1 in the gas generator 100 and supports the upper end surface 61 of the filter 6. The upper shell 2 has a cylindrical upper peripheral wall portion 21 and a top plate portion 22 that closes the upper end of the upper peripheral wall portion 21, and these form an internal space. The lower end of the upper peripheral wall portion 21 forms an opening of the upper shell 2. A joint portion 23 extending radially outward is connected to the lower end of the upper peripheral wall portion 21. The lower shell 3 is a part that constitutes a part of the housing 1 in the gas generator 100 and supports the lower end surface 62 of the filter 6. The lower shell 3 has a cylindrical lower peripheral wall portion 31 and a bottom plate portion 32 that closes the lower end of the lower peripheral wall portion 31 and has the ignition device 4 fixed thereto, and these form an internal space. The upper end of the lower peripheral wall portion 31 forms an opening of the lower shell 3. A joint portion 33 extending radially outward is connected to the upper end of the lower peripheral wall portion 31. The lower shell 3 corresponds to the "housing part" according to this disclosure.

The joint 23 of the upper shell 2 and the joint 33 of the lower shell 3 are overlapped and joined by laser welding or the like to form a short cylindrical housing 1 with both axial ends closed. The upper shell 2 and the lower shell 3 are joined only at the joints 23 and 33. The upper peripheral wall 21 of the upper shell 2 and the lower peripheral wall 31 of the lower shell 3 form a cylindrical peripheral wall 12 that connects the top plate 22 and the bottom plate 32. In other words, the housing 1 is configured to include the cylindrical peripheral wall 12, the top plate 22 provided on one end of the peripheral wall 12, and the bottom plate 32 provided on the other end to which the ignition device 4 is fixed. The top plate 22, the bottom plate 32, and the peripheral wall 12 define the combustion chamber 10. The top plate 22 corresponds to the "first wall" according to the present disclosure. The bottom plate 32 corresponds to the "second wall" according to the present disclosure. Additionally, multiple gas exhaust holes 11 that connect the combustion chamber 10 to the external space of the housing 1 are formed in the upper peripheral wall portion 21 of the peripheral wall portion 12 and aligned in the circumferential direction. Before the ignition device 4 is activated, the gas exhaust holes 11 are blocked by sealing tape (not shown).

Here, as shown in FIG. 1, the lower peripheral wall portion 31 of the lower shell 3 includes a first cylindrical wall portion 311, a second cylindrical wall portion 312, and an annular wall portion 313. The first cylindrical wall portion 311 is a cylindrical portion including the upper end portion of the lower peripheral wall portion 31, and is formed to have approximately the same diameter as the upper peripheral wall portion 21. The second cylindrical wall portion 312 is a cylindrical portion including the lower end portion of the lower peripheral wall portion 31, and is formed to have a smaller diameter than the first cylindrical wall portion 311. The annular wall portion 313 is an annular portion that connects the lower end portion of the first cylindrical wall portion 311 and the upper end portion of the second cylindrical wall portion 312. In other words, the annular wall portion 313 is located halfway through the peripheral wall portion 12 in the axial direction of the peripheral wall portion 12, and is located between the top plate portion 22 and the bottom plate portion 32. Also, as shown in FIG. 1, the annular wall portion 313 is inclined so that the diameter decreases toward the bottom plate portion 32 side. Here, the configuration of the peripheral wall portion 12 including the upper peripheral wall portion 21 and the first cylindrical wall portion 311 corresponds to the "large diameter portion" according to the present disclosure, the second cylindrical wall portion 312 corresponds to the "small diameter portion", and the annular wall portion 313 corresponds to the "connection portion". That is, the large diameter portion is a part of the peripheral wall portion 12, is located on the top plate portion 22 side, and is a cylindrical portion in which the gas discharge hole 11 is formed. The small diameter portion is a part of the peripheral wall portion 12, is located on the bottom plate portion 32 side, and is a cylindrical portion formed with a smaller diameter than the large diameter portion. The connection portion is an annular portion that connects the large diameter portion and the small diameter portion. In this example, the large diameter portion is formed by the entire upper peripheral wall portion 21 and a part of the lower peripheral wall portion 31, and the small diameter portion and the connection portion are formed by a part of the lower peripheral wall portion 31, but the present disclosure is not limited thereto. In the present disclosure, it is sufficient that the peripheral wall portion has a large diameter portion, a small diameter portion, and a connection portion. For example, the large diameter portion may be formed only by the upper peripheral wall portion 21, and the small diameter portion and the connection portion may be formed only by the lower peripheral wall portion 31.

[Ignition device]
As shown in FIG. 1, the ignition device 4 includes an igniter 41, a collar 42, and a resin part 43, and is fixed to the bottom plate part 32 of the lower shell 3. The ignition device 4 corresponds to the "ignition part" according to the present disclosure. The igniter 41 has a metal cup body 411 in which an ignition charge is accommodated, and a pair of current-carrying pins 412, 412 for receiving a current supply from the outside. The igniter 41 is activated by an ignition current supplied to the pair of current-carrying pins 412, 412 to burn the ignition charge and release the combustion product to the outside of the cup body 411. The collar 42 is a member that supports the igniter 41. The collar 42 is formed in a cylindrical shape, and is fixed by welding or the like in a state in which it is pressed into a mounting hole 32a formed in the bottom plate part 32. The resin part 43 is a resin member that is interposed between the igniter 41 and the collar 42 to fix the igniter 41 to the collar 42. The resin part 43 covers the lower part of the igniter 41 and engages with the collar 42, thereby fixing the igniter 41 to the collar 42 such that at least a part of the cup body 411 is exposed from the resin part 43. However, the entire cup body 411 may be overmolded by the resin part 43. That is, the entire cup body 411 may be covered with resin. The resin part 43 forms a connector insertion space inside the collar 42 into which a connector (not shown) that supplies power from an external power source to the pair of energizing pins 412, 412 can be inserted. The resin part 43 covers and holds a part of the pair of energizing pins 412, 412 such that the lower ends of the pair of energizing pins 412, 412 are exposed to the connector insertion space. The resin part 43 maintains insulation between the pair of energizing pins 412, 412. The fixing of the igniter 41 to the collar 42 and the relationship between the collar 42 and the bottom plate part 32 are not limited to those shown in FIG. 1, and known techniques can be used.

[Inner cylinder member]
The inner cylinder member 5 is a cylindrical member extending from the bottom plate portion 32 toward the top plate portion 22 so as to surround the ignition device 4. The inner cylinder member 5 is formed in a cylindrical shape with one end (upper end) closed and the other end (lower end) open, and is attached to the bottom plate portion 32 by fitting (pressing) a collar 42 into the lower end. The inner cylinder member 5 is disposed between the ignition device 4 and the gas generating agent 120, and a transfer chamber 51, which is a space in which a transfer charge 110 is accommodated, is formed between the inner cylinder member 5 and the ignition device 4. The transfer charge 110 burns when the igniter 41 is activated, generating combustion gas and the like. In addition, the inner cylinder member 5 is formed with a plurality of communication holes 52 that communicate its internal space (i.e., the transfer chamber 51) with an external space. The communication hole 52 is closed by a sealing tape (not shown) before the ignition device 4 is activated, and when the ignition device 4 is activated, the sealing tape is ruptured by the pressure of the combustion gas, thereby communicating between the inside and outside of the flame transfer chamber 51. Note that the communication hole 52 only needs to communicate between the inside and outside of the flame transfer chamber 51 at least when the ignition device 4 is activated, and does not need to be closed by a sealing tape.

[filter]
The filter 6 is a cylindrical member made of a metal material and has a plurality of holes. As shown in FIG. 1, the filter 6 is disposed in the combustion chamber 10 so that the gas generating agent is located inside the filter 6 and the gas discharge hole 11 is located outside the filter 6. That is, the filter 6 is disposed between the gas generating agent 120 and the gas discharge hole 11 in the combustion chamber 10 so as to surround the gas generating agent 120. Both axial end faces of the filter 6 are formed as flat surfaces. Of the both end faces, one end face (upper end face indicated by reference numeral 61) is supported by the housing 1 on the upper shell 2 side, and the other end face (lower end face indicated by reference numeral 62) is supported by the housing 1 on the lower shell 3 side. More specifically, the upper end face 61 is supported by the top plate portion 22 of the upper shell 2, and the lower end face 62 is supported by the annular wall portion 313 of the peripheral wall portion 12. A known sealing means may be disposed between the upper end face 61 and the top plate portion 22. As a result, the axial direction of the filter 6 is parallel to the axial direction of the housing 1 (i.e., the axial direction of the peripheral wall portion). In this example, the lower end surface 62 of the filter 6 corresponds to the "support end surface" according to the present disclosure. The filter 6 is supported by the housing 1 in a state in which a load is applied in the axial direction.

The filter 6 according to this embodiment has a multi-layer structure. Metal plates with holes formed therein are stacked in the radial direction (wound in multiple layers) to form the filter 6. Examples of the porous metal plate that is the material of the filter 6 include expanded metal, lath metal, and punched metal. Since multiple holes are formed in the filter 6, the combustion gas of the gas generating agent 120 arranged in the combustion chamber 10 can pass through the filter 6. The filter 6 cools the combustion gas by removing heat from the combustion gas when the combustion gas passes through the filter 6. In addition to the above-mentioned function of cooling the combustion gas, the filter 6 also has a function of filtering the combustion gas by collecting combustion residues contained in the combustion gas. In FIG. 1, the reference numeral 63 indicates the inner peripheral surface of the filter 6, and the reference numeral 64 indicates the outer peripheral surface of the filter 6. As will be described later, other known filters can be used for the filter 6.

[Explosive Charge]
As the enhancer charge 110, in addition to known black powder, a gas generating agent having good ignition properties and a higher combustion temperature than the gas generating agent 120 can be used. The combustion temperature of the enhancer charge 110 can be set in the range of 1700 to 3000°C. As such an enhancer charge 110, for example, known materials including nitroguanidine (34% by weight) and strontium nitrate (56% by weight) can be used. In addition, various shapes such as granular, pellet, cylindrical, and disk shapes can be adopted for the enhancer charge 110.

[Gas Generator]
A gas generating agent having a relatively low combustion temperature can be used as the gas generating agent 120. The combustion temperature of the gas generating agent 120 can be set in the range of 1000 to 1700°C. As such a gas generating agent 120, for example, a known agent containing guanidine nitrate (41% by weight), basic copper nitrate (49% by weight), a binder, and an additive can be used. In addition, the gas generating agent 120 can be in various shapes, such as granular, pellet, cylindrical, and disk shapes.

[motion]
The operation of the gas generator 100 according to the first embodiment will be described below. First, a description will be given with reference to FIG. 1. When a sensor (not shown) detects an impact, an ignition current is supplied to a pair of conductive pins 412, 412, and the igniter 41 is activated. Then, the ignition charge housed in the cup body 411 of the igniter 41 burns, and the combustion products such as flame and high-temperature gas are discharged to the outside of the cup body 411. As a result, the transfer charge 110 housed in the transfer chamber 51 burns, and combustion gas is generated. The combustion gas of the transfer charge 110 breaks the seal tape that has been blocking the communication hole 52 and is discharged from the communication hole 52 to the outside of the transfer chamber 51. Then, the combustion gas of the transfer charge 110 comes into contact with the gas generating agent 120, and the gas generating agent 120 is ignited. When the gas generating agent 120 burns, high-temperature and high-pressure combustion gas is generated in the combustion chamber 10. As the combustion gas passes through the filter 6, the combustion gas is cooled and combustion residue is collected. The combustion gas of the gas generating agent 120, cooled and filtered by the filter 6, passes through the gap 13, breaks the sealing tape blocking the gas discharge hole 11, and is discharged from the gas discharge hole 11 to the outside of the housing 1. After being discharged to the outside of the housing 1, the combustion gas of the gas generating agent 120 flows into an airbag (not shown). As the airbag inflates, a cushion is formed between the occupant and a hard structure, protecting the occupant from an impact.

[Filter Support]
As shown in FIG. 1, in the gas generator 100, the lower end surface 62 is supported by the annular wall portion 313 so as to be divided into a portion in contact with the annular wall portion 313 and a portion spaced apart from the annular wall portion 313 in the radial direction of the filter 6. Reference numeral 62a shown in FIG. 1 indicates the outer peripheral edge of the lower end surface 62 of the filter 6. Reference numeral 62b indicates a portion of the lower end surface 62 excluding the outer peripheral edge 62a, that is, a portion inside the outer peripheral edge 62a, and this is referred to as a non-outer peripheral portion. The outer peripheral edge 62a of the filter 6 corresponds to the "first portion" according to the present disclosure. The non-outer peripheral portion 62b of the filter 6 corresponds to the "second portion" according to the present disclosure. Reference numeral 313a indicates a surface of the annular wall portion 313 on the side that defines the combustion chamber 10, and this is referred to as an annular wall surface. That is, the annular wall surface 313a is a surface that supports the lower end surface 62 of the filter 6 in the housing 1. The annular wall surface 313a corresponds to the "support portion" according to the present disclosure.

As shown in Fig. 1, the annular wall surface 313a is inclined so as to decrease in diameter as it moves away from the filter 6 in the axial direction of the filter 6. Therefore, the lower end surface 62 is supported by the annular wall portion 313 with the outer peripheral edge 62a, which is a part of the lower end surface 62, in contact with the annular wall portion 313 and with the non-outer peripheral portion 62b spaced apart from the annular wall portion 313. That is, the lower end surface 62 is supported by the housing 1 with the outer peripheral edge 62a, which is a part of the lower end surface 62. As described above, the filter 6 is in a state in which a load is applied in the axial direction by the housing 1, and therefore the outer peripheral edge 62a of the filter 6 presses the housing 1. The lower end surface 62 is supported by the annular wall portion 313 with the outer peripheral edge 62a, and the outer peripheral edge 62a presses the annular wall portion 313, so that the load is concentrated on the outer peripheral edge 62a. Therefore, the outer peripheral edge 62a of the lower end surface 62 contacts the annular wall portion 313 more strongly than when the entire lower end surface 62 including the non-outer peripheral portion 62b is supported by the annular wall portion 313 (that is, the filter 6 is in a state in which the load is concentrated at the outer peripheral edge 62a with respect to the annular wall surface 313a). Here, FIG. 2 is an enlarged view of the vicinity of the contact point between the lower end surface 62 of the filter 6 and the annular wall portion 313 of the housing 1 in FIG. 1. As shown in FIG. 2, in the gas generator 100, the load is concentrated at the outer peripheral edge 62a of the lower end surface 62, so that the outer peripheral edge 62a bites into the annular wall portion 313. Here, the outer peripheral edge 62a bites into the annular wall portion 313 refers to a state in which the corner portion of the outer peripheral edge 62a (the corner portion defined by the outer peripheral surface 64 and the lower end surface 62) enters the annular wall surface 313a even if only slightly. In other words, it can be said that the annular wall portion 313 is in a state in which it is slightly deformed so as to receive the corner portion of the outer peripheral edge 62a. At this time, outer peripheral edge 62a biting into annular wall portion 313 does not need to be deformed. Moreover, Fig. 3 is an end view of filter 6 in gas generator 100 according to embodiment 1, as viewed from the lower end face side. In gas generator 100, outer peripheral edge 62a that contacts annular wall portion 313 of housing 1 is formed in an annular shape along the circumferential direction of filter 6, as shown in Fig. 3. Therefore, in gas generator 100, contact between outer peripheral edge 62a of lower end face 62 and annular wall portion 313 of housing 1 causes
These contact states are formed in an annular shape along the circumferential direction of the filter 6. That is, the contact state between the lower end surface 62 of the filter 6 and the housing 1 is formed over the entire circumference of the lower end surface 62. The hardness of the housing 1 (annular wall portion 313) and the hardness of the filter 6 may be different. For example, when the filter 6 is harder than the annular wall portion 313, the outer peripheral edge 62a is in an annular shape and bites into the annular wall portion 313 in the state shown in FIG. 1. On the other hand, when the annular wall portion 313 is harder than the filter 6, the outer peripheral edge 62a of the filter 6 is deformed even slightly, and the filter 6 comes into contact with the annular wall surface 313a with an increased contact area.

[Method of assembling the gas generator]
Next, a method of assembling the gas generator according to the first embodiment will be described. However, the method of assembling the gas generator of the present disclosure is not limited to the following method. Fig. 4 is a flowchart of a method of assembling gas generator 100 according to the first embodiment. The following description will be given based on Fig. 4.

First, in the preparation process of step S101, the upper shell 2, the lower shell 3 (housing parts), the ignition device 4, the inner cylinder member 5, and the filter 6 are prepared.

Next, in the ignition device installation process in step S102, the ignition device 4 is installed to the lower shell 3. In step S102, the ignition device 4 is inserted through an opening in the lower shell 3. The ignition device 4 is fixed to the lower shell 3 by being welded to the bottom plate portion 32 while fitted into the mounting hole 32a.

Next, in the inner cylinder member attachment process of step S103, the inner cylinder member 5 is attached to the lower shell 3 to which the ignition device 4 is fixed. In step S103, the ignition device 4 (more specifically, the collar 42) is inserted (pressed) into the opening of the inner cylinder member 5 filled with the transfer charge 110, thereby attaching the inner cylinder member 5 so as to surround the ignition device 4. This forms the transfer chamber 51.

Next, in the filter assembly process of step S104, the filter 6 is assembled concentrically to the lower shell 3 to which the inner tube member 5 is attached. Figures 5 and 6 are diagrams for explaining the filter assembly process according to embodiment 1. In step S104, first, as shown in Figure 5, the filter 6 is inserted from the opening of the lower shell 3, and the lower end surface 62 of the filter 6 is brought into contact with the annular wall portion 313 of the lower shell 3. Here, as described above, the annular wall surface 313a of the annular wall portion 313 is inclined so as to reduce in diameter as it moves away from the filter 6 in the axial direction of the filter 6, so that, as shown in Figure 5, the lower end surface 62 of the filter 6 is in a state in which the outer peripheral edge 62a is in contact with the annular wall surface 313a and the non-outer peripheral portion 62b is separated from the annular wall surface 313a. In addition, the contact state between the outer peripheral edge 62a and the annular wall surface 313a is formed in an annular shape along the circumferential direction of the filter 6. In step S104, the inside of the filter 6 is then filled with the gas generating agent 120. In step S104, the housing 1 is formed by attaching the upper shell 2 to the lower shell 3 as shown in FIG. 6. The housing 1 is formed by joining the joint 23 and the joint 33 in a state where the opening of the upper shell 2 and the opening of the lower shell 3 face each other. At this time, the contact parts of the upper shell 2 and the lower shell 3 in the housing 1 are joined by a suitable joining method (e.g., welding, etc.) for preventing moisture from being generated from the gas generating agent filled inside. In step S104, the upper shell 2 is attached so that the top plate portion 22 of the upper shell 2 contacts the upper end surface 61 of the filter 6. The filter 6 is sandwiched from both sides in the axial direction by the top plate portion 22 of the upper shell 2 and the annular wall portion 313 of the lower shell 3, and the outer peripheral edge 62a of the lower end surface 62 of the filter 6 presses the annular wall portion 313 of the housing 1. In this manner, the lower end surface 62 of the filter 6 is supported by the annular wall portion 313, and the gas generator 100 is assembled.

[Action and Effects]
In a gas generator, when a gas generating agent is burned and combustion gas is generated in a combustion chamber, a load acts on the filter in the radial outward direction due to the pressure of the combustion gas. If the load acting in the radial outward direction causes an end of the filter to separate from the housing and a gap is formed between the end of the filter and the housing, there is a concern that part of the combustion gas will pass through the gap and reach the gas exhaust hole without passing through the filter. In other words, there is a risk of a so-called "short pass" occurring.

In contrast, in the gas generator 100, the lower end surface 62 of the filter 6 is supported by the annular wall portion 313 of the housing 1 with the outer peripheral edge 62a, which is a part of the lower end surface 62, in contact with the annular wall portion 313 of the housing 1 and pressing against the annular wall portion 313, and with the non-outer peripheral portion 62b, which is the portion of the lower end surface 62 excluding the outer peripheral edge 62a, spaced apart from the annular wall portion 313. The contact state between the outer peripheral edge 62a of the filter 6 and the annular wall portion 313 is formed in a ring shape along the circumferential direction of the filter 6.

By supporting the lower end surface 62 with the outer peripheral edge 62a and concentrating the load on the outer peripheral edge 62a, the outer peripheral edge 62a and the housing 1 can be brought into strong contact with each other. In addition, by forming the contact state between the outer peripheral edge 62a and the housing 1 in an annular shape along the circumferential direction of the filter 6, no gap is formed between the lower end surface 62 and the housing 1 that allows the combustion gas to pass from the inner peripheral surface 63 side of the filter 6 to the outer peripheral surface 64 side. As a result, the gas generator 100 can effectively suppress short passes.

In addition, in the gas generator 100, the outer peripheral edge 62a of the filter 6 is embedded in the annular wall portion 313 of the housing 1, making it more difficult for gaps to form and effectively suppressing short passes. Note that as long as the contact state between the outer peripheral edge 62a of the lower end face 62 and the annular wall portion 313 is formed around the entire circumference of the lower end face 62, the outer peripheral edge 62a does not have to embed itself in the annular wall portion 313 of the housing 1.

Furthermore, in the gas generator 100, the annular wall surface 313a that supports the lower end surface 62 in the housing 1 is inclined so that the diameter decreases as it moves away from the filter 6 in the axial direction of the filter 6. This allows the lower end surface 62 to be supported by the housing 1 at the outer peripheral edge 62a.

In a gas generator, the combustion gas flows toward the gas exhaust hole, so most of the combustion gas that passes through the filter passes through the portion of the filter near the gas exhaust hole, and the amount of combustion gas that passes through the portion farther from the gas exhaust hole tends to be smaller. Therefore, in a gas generator in which a gas exhaust hole is formed on the top plate side of the peripheral wall, such as gas generator 100, if the filter is provided from the top plate to the bottom plate, the portion of the filter near the bottom plate farther from the gas exhaust hole does not allow much combustion gas to pass through, and does not contribute much to cooling and filtering the combustion gas.

In contrast, in the gas generator 100, the lower end surface 62 is supported by the annular wall surface 313a included in the annular wall portion 313. As described above, the annular wall portion 313 is located between the top plate portion 22 and the bottom plate portion 32 in the axial direction of the peripheral wall portion 12. In other words, the filter 6, whose lower end surface 62 is supported by the annular wall portion 313, is biased toward the top plate portion 22 side and does not extend to the vicinity of the bottom plate portion 32 through which little combustion gas passes. Therefore, in the gas generator 100, the filter 6 can be used more efficiently than when the upper end surface of the filter is supported by the top plate portion and the lower end surface is supported by the bottom plate portion. In other words, the filter can be made compact while still ensuring sufficient cooling and filtering functions for the combustion gas, which contributes to reducing the weight and cost of the filter.

As shown in FIG. 1, in the gas generator 100, the lower end surface 62 of the filter 6 is supported by the housing 1 so that a groove indicated by the symbol G1 is formed between the non-outer peripheral portion 62b and the annular wall portion 313 while the outer peripheral edge 62a is in contact with the annular wall portion 313. The groove G1 opens in an annular shape on the radially inner side of the filter 6. Therefore, when the combustion gas flows toward the gas exhaust hole 11, the combustion gas residue is likely to accumulate in the groove G1. This can improve the combustion residue collection performance.

1, the inner cylinder member 5 of the gas generator 100 is formed with a communication hole 52 that communicates the inside and outside of the transfer chamber 51 at least when the ignition device 4 is activated, and the communication hole 52 is located between the bottom plate portion 32 and the lower end surface 62 of the filter 6 in the axial direction of the filter 6. The gas generating agent 120 is ignited by the combustion gas of the transfer charge 110 ejected from the communication hole 52. Therefore, by positioning the communication hole 52 between the bottom plate portion 32 and the lower end surface 62 of the filter 6, the gas generating agent 120 in the combustion chamber 10 is burned first from the one located between the bottom plate portion 32 and the lower end surface 62 of the filter 6. As a result, the combustion gas of the gas generating agent 120 flows from the bottom plate portion 32 toward the top plate portion 22. As a result, the groove G1 in the middle functions as a residue collection pocket, making it easier to collect the residue of the combustion gas. In addition, the inner cylinder member 5 may have communication holes at other positions in addition to the communication hole 52 shown in FIG. 1.

Furthermore, a compression molded filter such as that disclosed in Japanese Patent Application Laid-Open No. 10-119705 or a wound filter such as that disclosed in Japanese Patent Application Laid-Open No. 11-348712 may be used as the filter 6, and the filter 6 may be positioned so that the outer peripheral edge 62a strongly presses against the annular wall portion 313 to deform it, and a groove G1 is formed by the non-outer peripheral portion 62b and the annular wall portion 313.

[Modification of the first embodiment]
Hereinafter, a gas generator according to a modification of embodiment 1 will be described. In the description of the modification, differences from gas generator 100 described in Fig. 1 to Fig. 6 will be mainly described, and the same reference numerals will be used to denote the same points as gas generator 100, and detailed description thereof will be omitted.

[Modification 1 of the First Embodiment]
Fig. 7 is an axial cross-sectional view of gas generator 100A according to modified example 1 of embodiment 1. Fig. 7 shows a state before activation of gas generator 100A. As shown in Fig. 7, in gas generator 100A, filter 6 is supported by housing 1 such that inner circumferential surface 63 of filter 6 is located radially inward of second cylindrical wall portion 312 of lower peripheral wall portion 31 relative to inner circumferential surface 312a of second cylindrical wall portion 312 of lower peripheral wall portion 31. As a result, lower end surface 62 of filter 6 protrudes radially inward relative to second cylindrical wall portion 312 of lower peripheral wall portion 31, and combustion gas residue is easily captured by lower end surface 62 of filter 6 and groove G1. That is, lower end surface 62 of filter 6 can be more effectively utilized in collecting combustion gas residue.

[Modification 2 of the First Embodiment]
Fig. 8 is an axial cross-sectional view of gas generator 100B according to modification 2 of embodiment 1. Fig. 8 shows a state before activation of gas generator 100B. In gas generator 100B, both upper end surface 61 and lower end surface 62 of filter 6 correspond to the "support end surface" according to the present disclosure.

As shown in FIG. 8, in gas generator 100B, similar to gas generator 100, the lower end surface 62 of filter 6 is supported by annular wall portion 313 of housing 1 with outer peripheral edge 62a in contact with annular wall portion 313 of housing 1 and pressing against the annular wall portion 313, and with non-outer peripheral portion 62b spaced apart from the annular wall portion 313. In addition, the contact state between outer peripheral edge 62a of filter 6 and annular wall portion 313 is formed in an annular shape along the circumferential direction of filter 6. Furthermore, in gas generator 100B, upper end surface 61 of filter 6 is also supported by housing 1 with outer peripheral edge 61a, which is a part of the upper end surface 61.

As shown in FIG. 8, the top plate portion 22B of the gas generator 100B includes a top wall portion 221 and an inclined wall portion 222. The top wall portion 221 is a portion that defines the upper end of the combustion chamber 10, and extends in the radial direction of the filter 6 so as to be perpendicular to the axial direction of the filter 6. The inclined wall portion 222 is an annular portion that supports the upper end surface 61 of the filter 6, and is connected to the upper peripheral wall portion 21 and is inclined so as to decrease in diameter as it moves away from the filter 6 in the axial direction of the filter 6.

8 indicates the outer peripheral edge of the upper end surface 61 of the filter 6. Also, reference numeral 61b indicates a non-outer peripheral portion of the upper end surface 61, which is a portion excluding the outer peripheral edge 61a. Also, reference numeral 222a indicates the surface of the inclined wall portion 222 that defines the combustion chamber 10, and this is referred to as the inclined wall surface. The inclined wall surface 222a of the inclined wall portion 222 corresponds to the "support portion" according to the present disclosure. The inclined wall surface 222a is inclined so that the diameter decreases as it moves away from the filter 6 in the axial direction of the filter 6. Therefore, the upper end surface 61 is supported by the housing 1 in a state in which the outer peripheral edge 61a, which is a part of the upper end surface 61, contacts the inclined wall portion 222 and presses the inclined wall portion 222, and in a state in which the non-outer peripheral portion 61b is separated from the inclined wall portion 222. And, the contact state between the outer peripheral edge 61a of the filter 6 and the inclined wall portion 222 is formed in a ring shape along the circumferential direction of the filter 6.

According to the gas generator 100B, as with the gas generator 100, no gap is formed between the lower end surface 62 and the housing 1. Furthermore, according to the gas generator 100B, the upper end surface 61 is supported by the outer peripheral edge 61a, the load is concentrated on the outer peripheral edge 61a, and the outer peripheral edge 61a and the housing 1 (inclined wall portion 222) are strongly contacted, and the contact state between the outer peripheral edge 61a and the housing 1 is formed in an annular shape along the circumferential direction of the filter 6, so that no gap is formed between the upper end surface 61 and the housing 1.

In other words, the gas generator 100B can prevent gaps from being formed between the housing 1 and both end faces of the filter 6. As a result, the gas generator 100B can more effectively suppress short-passing.

[Modification 3 of the First Embodiment]
Fig. 9 is an axial cross-sectional view of gas generator 100C according to modification 3 of embodiment 1. Fig. 9 shows a state before activation of gas generator 100C. Gas generator 100C differs from gas generator 100 mainly in that lower end surface 62 of filter 6 is supported not by a part of the peripheral wall portion but by a part of the bottom plate portion.

As shown in FIG. 9, the peripheral wall portion 12C of the gas generator 100C does not have an annular wall portion 313, and has the same diameter from the top plate portion 22 to the bottom plate portion 32C. The bottom plate portion 32C of the gas generator 100C includes a bottom wall portion 321 and an inclined wall portion 322. The bottom wall portion 321 is a portion that defines the lower end of the combustion chamber 10, and extends in the radial direction of the filter 6 so as to be perpendicular to the axial direction of the filter 6. The inclined wall portion 322 is an annular portion that supports the lower end surface 62 of the filter 6, and is connected to the lower peripheral wall portion 31 and is inclined so as to decrease in diameter as it moves away from the filter 6 in the axial direction of the filter 6.

The reference numeral 322a in FIG. 9 indicates the surface of the inclined wall portion 322 that defines the combustion chamber 10, and is referred to as the inclined wall surface. The inclined wall surface 322a of the inclined wall portion 322 corresponds to the "support portion" according to the present disclosure. The inclined wall surface 322a is inclined so that its diameter decreases as it moves away from the filter 6 in the axial direction of the filter 6.

With gas generator 100C, like gas generator 100, no gap is formed between the lower end surface 62 and the housing 1, and short passes can be effectively suppressed.

<Embodiment 2>
Fig. 10 is an axial cross-sectional view of gas generator 200 according to embodiment 2. Fig. 10 shows a state before activation of gas generator 200. Hereinafter, gas generator 200 according to embodiment 2 will be described, focusing on differences from gas generator 100 according to embodiment 1, and detailed description of similar points to gas generator 100 will be omitted by assigning the same reference numerals thereto.

10, the lower end surface 62 of the filter 6D of the gas generator 200 has a protruding portion 62c, which is an annular portion that protrudes in the axial direction of the filter 6D more than other portions of the lower end surface 62. The remaining portions of the lower end surface 62 except for the protruding portion 62c are referred to as non-protruding portions and are indicated by the reference symbol 62d. The protruding portion 62c in this example is formed by the outermost layer of the multiple layers constituting the filter 6D protruding in the axial direction of the filter 6D more than the other layers. However, the protruding portion in the example of FIG. 10 does not have to be formed in the outermost layer of the filter, and may be formed in, for example, an intermediate layer. The protruding portion 62c of the filter 6D corresponds to the "first portion" according to the present disclosure. The non-protruding portion 62d of the filter 6D corresponds to the "second portion" according to the present disclosure.

As shown in FIG. 10, the annular wall surface 313a of the annular wall portion 313D of the peripheral wall portion 12 that supports the lower end surface 62 of the filter 6D is a flat surface that is not inclined and extends in the radial direction of the filter 6D so as to be perpendicular to the axial direction of the filter 6D.

In the filter 6D, the protruding portion 62c protrudes in the axial direction from the lower end surface 62, so that, as shown in FIG. 10, the lower end surface 62 of the filter 6D is supported by the annular wall portion 313D in a state in which the protruding portion 62c contacts the annular wall portion 313D of the housing 1 and presses the annular wall portion 313D, and the non-protruding portion 62d is separated from the annular wall portion 313D. Therefore, the load is concentrated on the protruding portion 62c, and the protruding portion 62c strongly contacts the annular wall portion 313D. In the gas generator 200, the load is concentrated on the protruding portion 62c of the lower end surface 62, so that the protruding portion 62c bites into the annular wall portion 313D. Here, the protruding portion 62c bites into the annular wall portion 313D means that the protruding portion 62c has entered the annular wall surface 313a even if only slightly. In other words, it can be said that the annular wall portion 313D is in a state in which it is slightly deformed to receive the protruding portion 62c. Here, Fig. 11 is an end view of the filter 6D in the gas generator 200 according to the second embodiment, as viewed from the bottom end surface side. In the gas generator 200, the protruding portion 62c that contacts the annular wall portion 313D of the housing 1 is formed in an annular shape along the circumferential direction of the filter 6D, as shown in Fig. 11. Therefore, in the gas generator 200, the protruding portion 62c of the bottom end surface 62 contacts the annular wall portion 313D of the housing 1, and the contact state between them is formed in an annular shape along the circumferential direction of the filter 6D.

With this type of gas generator 200, like the gas generator 100, no gap is formed between the lower end surface 62 and the housing 1, and short passes can be effectively suppressed.

In the gas generator 200, the protrusion 62c of the filter 6D is also embedded in the annular wall 313D of the housing 1, making it more difficult for gaps to form and effectively suppressing short passes. As long as the contact state between the protrusion 62c of the lower end face 62 and the annular wall 313D is formed around the entire circumference of the lower end face 62, the protrusion 62c does not have to embed itself in the annular wall 313D of the housing 1. Furthermore, the annular wall to be combined with the filter 6D may be the inclined annular wall 313 shown in FIG. 1, etc.

12(A) and 12(B) are diagrams for explaining an example of a manufacturing method of the filter 6D according to the second embodiment. The filter 6D can be manufactured, for example, by winding the porous metal plate 60 shown in FIG. 12(A) as shown in FIG. 12(B). As shown in FIG. 12(A), the porous metal plate 60 is formed in an elongated shape, and is partitioned in the longitudinal direction into a main body portion 601 located at one end side and a wide portion 602 located at the other end side and having a width greater than that of the main body portion 601. The wide portion 602 is a portion that becomes the outermost layer of the filter 6D. The porous metal plate 60 is wound from the main body portion 601 as shown in FIG. 12(B), thereby manufacturing the filter 6D having the protruding portion 62c.

The method of assembling the gas generator 200 is generally similar to the method of assembling the gas generator 100 described in FIG. 4. In the method of assembling the gas generator 200, in the filter assembly process of step S104, the filter 6D is assembled to the lower shell 3 so that the lower end surface 62 is supported by the annular wall portion 313D at the protrusion 62c, and the contact state between the protrusion 62c and the annular wall portion 313D is formed in an annular shape along the circumferential direction of the filter 6D.

<Embodiment 3>
Fig. 13 is an axial cross-sectional view of gas generator 300 according to embodiment 3. Fig. 13 shows a state before activation of gas generator 300. Hereinafter, gas generator 300 according to embodiment 3 will be described, focusing on differences from gas generator 100 according to embodiment 1, and detailed description of similar points to gas generator 100 will be omitted by assigning the same reference numerals thereto.

As shown in FIG. 13, the gas generator 300 includes a first ignition device 4X, a second ignition device 4Y, an inner cylinder member 5E, a filter 6, a transfer charge 110, a first gas generating agent 120X, a second gas generating agent 120Y, and a housing 1E that accommodates these. The gas generator 300 is configured as a so-called dual-type gas generator having two ignition devices. In the gas generator 300, the first ignition device 4X corresponds to the "ignition section" according to the present disclosure. The gas generator 300 is configured to burn the first gas generating agent 120X by operating the first ignition device 4X, and burn the second gas generating agent 120Y by operating the second ignition device 4Y, thereby discharging a relatively large amount of combustion gas from the gas exhaust hole 11. In the gas generator 300, the second ignition device 4Y operates independently of the first ignition device 4X, and when it does operate, it operates at a predetermined timing after the operation of the first ignition device 4X.

As shown in FIG. 13, the housing 1E according to the third embodiment has a partition wall portion 14 that separates the internal space of the housing 1E into the first combustion chamber 10X and the second combustion chamber 10Y and abuts against and supports the lower end surface 62 of the filter 6. The partition wall portion 14 is provided between the top plate portion 22E and the bottom plate portion 32 in the axial direction of the filter 6. That is, the partition wall portion 14 is provided on the other end side of the peripheral wall portion 12 with respect to the top plate portion 22E provided on one end side of the peripheral wall portion 12. The first combustion chamber 10X is defined by the top plate portion 22E, the partition wall portion 14, and the peripheral wall portion 12. The second combustion chamber 10Y is defined by the partition wall portion 14, the bottom plate portion 32, and the peripheral wall portion 12. In the gas generator 300, the top plate portion 22E corresponds to the "first wall portion" according to the present disclosure, and the partition wall portion 14 corresponds to the "second wall portion" according to the present disclosure. The first combustion chamber 10X contains a first gas generating agent 120X that is combusted by the operation of the first ignition device 4X, and the second combustion chamber 10Y contains a second gas generating agent 120Y that is combusted by the operation of the second ignition device 4Y. The first combustion chamber 10X corresponds to the "combustion chamber" according to the present disclosure, and the first gas generating agent 120X corresponds to the "gas generating agent" according to the present disclosure.

The partition wall 14 includes a dividing wall 141, a fitting wall 142, and a terminal end 143. The dividing wall 141 is a portion that defines the lower end of the first combustion chamber 10X, and extends in the radial direction of the filter 6 so as to be perpendicular to the axial direction of the filter 6. The dividing wall 141 has a through hole 14a through which the inner tube member 5E passes. The fitting wall 142 is a cylindrical portion that fits into the lower peripheral wall 31 of the lower shell 3, and extends from the periphery of the dividing wall 141 to the inside (i.e., upper side) of the first combustion chamber 10X along the axial direction of the filter 6. The terminal end 143 is an annular portion that is placed on the upper end of the lower peripheral wall 31 of the lower shell 3, and extends radially outward from the upper end of the fitting wall 142.

The inner cylinder member 5E according to the third embodiment extends from the bottom plate portion 32 toward the top plate portion 22E so as to surround the first ignition device 4X fixed to the bottom plate portion 32, passes through the through hole 14a of the partition portion 14, and has an open end. Therefore, the space inside the inner cylinder member 5E is included in the first combustion chamber 10X, and the first ignition device 4X is disposed in the first combustion chamber 10X. In addition, a partition member P1 is disposed inside the inner cylinder member 5E to separate the internal space into upper and lower portions. As a result, the space below the partition member P1 (the first ignition device 4X side) of the internal space of the inner cylinder member 5 is formed as a transfer chamber 51. The transfer charge 110 is contained in the transfer chamber 51 without being mixed with the first gas generating agent 120X. The partition member P1 is made of a material that quickly burns, melts, or disappears due to the combustion gas of the transfer charge 110 so as not to impede the ignition of the first gas generating agent 120X by the combustion gas of the transfer charge 110. In addition, the inner cylinder member 5E is formed with a plurality of communication holes 52 that communicate the internal space of the inner cylinder member 5E (and thus the first combustion chamber 10X) with the second combustion chamber 10Y. The communication holes 52 are closed with a sealing tape (not shown) before the second ignition device 4Y is activated.

As shown in FIG. 13, in the gas generator 300, the filter 6 is disposed in the first combustion chamber 10X so that the upper end surface 61 is supported by abutting against the top plate portion 22E and the lower end surface 62 is supported by abutting against the partition wall portion 141 in the partition portion 14. The top plate portion 22E of the gas generator 300 includes a top wall portion 221 and an inclined wall portion 222. The top wall portion 221 is a portion that defines the upper end of the first combustion chamber 10X and extends in the radial direction of the filter 6 so as to be perpendicular to the axial direction of the filter 6. The inclined wall portion 222 is an annular portion that supports the upper end surface 61 of the filter 6. The inclined wall surface 222a, which is the surface of the inclined wall portion 222 that defines the first combustion chamber 10X, is connected to the upper peripheral wall portion 21 and is inclined so as to decrease in diameter as it moves away from the filter 6 in the axial direction of the filter 6.

Therefore, the upper end surface 61 of the filter 6 is supported by the housing 1E with the outer peripheral edge 61a, which is a part of the upper end surface 61, in contact with the inclined wall portion 222 and pressing against the inclined wall portion 222, and with the non-outer peripheral portion 61b spaced apart from the inclined wall portion 222. The contact state between the outer peripheral edge 61a of the filter 6 and the inclined wall portion 222 is formed in a ring shape along the circumferential direction of the filter 6.

When such a gas generator 300 is operated, first, the first ignition device 4X is operated, and the transfer charge 110 contained in the transfer chamber 51 of the first combustion chamber 10X is burned, generating the combustion gas. The partition member P1 is burned and removed by the combustion gas of the transfer charge 110, and the combustion gas comes into contact with the first gas generating agent 120X, igniting the first gas generating agent 120X. The first gas generating agent 120X burns, generating the combustion gas in the first combustion chamber 10X. The combustion gas of the first gas generating agent 120X passes through the filter 6 and is discharged from the gas exhaust hole 11 to the outside of the housing 1E. Next, the second ignition device 4Y is operated, and the second gas generating agent 120Y contained in the second combustion chamber 10Y is burned, generating the combustion gas. The combustion gas from the second gas generating agent 120Y breaks the sealing tape that was blocking the communication hole 52, flows from the communication hole 52 into the first combustion chamber 10X, passes through the filter 6, and is released from the gas exhaust hole 11 to the outside of the housing 1E.

According to the gas generator 300 of the third embodiment, the upper end surface 61 is supported by the outer peripheral edge 61a, and the load is concentrated on the outer peripheral edge 61a to bring the outer peripheral edge 61a into strong contact with the housing 1E (inclined wall portion 222), and the contact state between the outer peripheral edge 61a and the housing 1E is formed in an annular shape along the circumferential direction of the filter 6, so that no gap is formed between the upper end surface 61 and the housing 1E. As a result, the gas generator 300 can effectively suppress short passes.

<Other Examples>
Fig. 14 is a diagram showing a modified example of the filter support. Fig. 14 shows a case where the modified example of the filter support is applied to the gas generator 100C shown in Fig. 9. As shown in Fig. 14, instead of the inclined wall portion 322, the lower end surface 62 of the filter 6 may be supported by an R wall portion 322C having R (curvature). The R wall portion 322C is an annular portion that connects the lower peripheral wall portion 31 and the bottom wall portion 321 and has an arc shape in a cross section perpendicular to the circumferential direction. The R wall surface 322Ca, which is the surface of the R wall portion 322C that defines the combustion chamber 10, is curved so as to reduce in diameter as it moves away from the filter 6 in the axial direction of the filter 6. Therefore, the lower end surface 62 is supported by the housing 1 in a state where the outer peripheral edge 62a, which is a part of the lower end surface 62, contacts the R wall portion 322C and presses the R wall portion 322C, and in a state where the non-outer peripheral portion 62b is separated from the R wall portion 322C. At this time, the contact state between the outer peripheral edge 62a of the lower end surface 62 of the filter 6 and the R-wall portion 322C is formed in an annular shape along the circumferential direction of the filter 6. A groove G1 is formed between the non-outer peripheral portion 62b and the R-wall portion 322C.

This configuration of supporting the filter at the R portion can be applied to any of the embodiments shown in Figures 1, 7 to 10, and 13. For example, in the gas generator shown in Figure 10, an R wall portion can be formed between the first cylindrical wall portion 311 and the annular wall portion 313D, and the protruding portion 62c of the lower end surface 62 of the filter 6D can be strongly supported by the R portion, and a gap G1 can be formed between the non-protruding portion 62d and the annular wall portion 313D.

＜Other＞
Although the preferred embodiments of the present disclosure have been described above, each aspect disclosed in this specification can be combined with any other feature disclosed in this specification.

100, 200, 300 Gas generator 1 Housing 11 Gas exhaust hole 12 Peripheral wall portion 14 Partition wall portion (an example of a second wall portion)
2 Upper shell 22 Top plate portion (an example of a first wall portion)
222 Inclined wall portion 3 Lower shell 312 Annular wall portion (an example of a connection portion)
32 Bottom plate portion (an example of a second wall portion)
322 Inclined wall portion 4 Ignition device (an example of an ignition portion)
5 Inner cylinder member 6 Filter 61 Upper end surface (one end surface of the filter)
62 Lower end surface (other end surface of filter)
62a Outer periphery (an example of the first portion)
62b: non-outer periphery portion (an example of the second portion)
62c protruding portion (an example of a first portion)
62d non-protruding portion (an example of the second portion)
10 Combustion chamber 120 Gas generating agent

Claims (11)

a combustion chamber in which an ignition unit and a gas generating agent that is combusted by activation of the ignition unit are disposed;
a housing defining the combustion chamber, the housing including a cylindrical peripheral wall portion, a first wall portion provided on one end side of the peripheral wall portion, and a second wall portion provided on the other end side of the peripheral wall portion, the peripheral wall portion being provided with a gas exhaust hole communicating the combustion chamber with the outside of the housing;
a filter formed in a cylindrical shape, the filter being disposed between the gas generating agent and the gas discharge hole in the combustion chamber so as to surround the gas generating agent, one axial end face of the filter being supported by the housing on the side of the first wall portion and the other axial end face being supported by the housing on the side of the second wall portion;
A gas generator comprising:
a support end surface which is at least one of both end surfaces in the axial direction of the filter is supported by the housing in a state in which a first portion which is a part of the support end surface contacts the housing and presses the housing, and a second portion which is a portion of the support end surface excluding the first portion is separated from the housing,
The support end surface is supported by the housing at an outer circumferential edge thereof as the first portion,
A contact state between the first portion of the support end surface and the housing is such that the outer peripheral edge bites into the housing , causing the housing to deform to receive the first portion , and the contact state is formed in an annular shape along the circumferential direction of the filter.
Gas generator. a support portion for supporting the support end surface of the housing is inclined so as to decrease in diameter as it moves away from the filter in the axial direction of the filter,
The support end surface is supported by the housing with an outer circumferential edge thereof serving as the first portion.
2. The gas generator according to claim 1. the support end surface has a protruding portion that is an annular portion protruding in an axial direction of the filter more than other portions of the support end surface, and the protruding portion is supported by the housing as the first portion.
3. A gas generator according to claim 1 or 2. The ignition unit is fixed to the second wall portion,
At least the other end surface of the filter is the support end surface,
the peripheral wall portion includes a cylindrical large diameter portion located on the first wall portion side and having the gas discharge hole formed therein, a cylindrical small diameter portion located on the second wall portion side and having a smaller diameter than the large diameter portion, and an annular connecting portion connecting the large diameter portion and the small diameter portion,
A support portion for supporting the other end surface of the filter in the housing is included in the connection portion.
A gas generator according to any one of claims 1 to 3. The other end surface of the filter is supported by the housing such that a groove opening to a radially inner side of the filter is formed between the second portion and the connection portion.
5. The gas generator according to claim 4. an inner circumferential surface of the filter is located radially inside the small diameter portion relative to an inner circumferential surface of the small diameter portion;
6. The gas generator according to claim 5. In the combustion chamber, a cylindrical inner cylinder member is disposed so as to surround the ignition unit, and a transfer chamber is formed between the ignition unit and the inner cylinder member, the transfer chamber containing a transfer charge that is burned by activation of the ignition unit to burn the gas generating agent,
The inner cylinder member is formed with a communication hole that communicates the inside and the outside of the transfer chamber at least when the ignition unit is activated,
The communication hole is located between the second wall portion and the other end surface of the filter in the axial direction of the filter.
A gas generator according to any one of claims 4 to 6. Both axial end surfaces of the filter are the support end surfaces.
A gas generator according to any one of claims 1 to 7. a combustion chamber in which an ignition unit and a gas generating agent that is combusted by activation of the ignition unit are disposed;
a housing defining the combustion chamber, the housing including a cylindrical peripheral wall portion, a first wall portion provided on one end side of the peripheral wall portion, and a second wall portion provided on the other end side of the peripheral wall portion, the peripheral wall portion being provided with a gas exhaust hole communicating the combustion chamber with the outside of the housing;
a filter formed in a cylindrical shape, the filter being disposed between the gas generating agent and the gas discharge hole in the combustion chamber so as to surround the gas generating agent, one axial end face of the filter being supported by the housing on the side of the first wall portion and the other axial end face being supported by the housing on the side of the second wall portion;
A method for assembling a gas generator comprising:
preparing a housing part constituting a part of the housing in the gas generator and supporting a support end surface, which is at least one of both end surfaces in an axial direction of the filter, and the filter;
and assembling the filter to the housing part such that a first portion, which is an outer peripheral edge of the support end surface, contacts the housing and presses the housing while a second portion, which is a portion other than the first portion, is spaced from the housing , and the housing is deformed to receive the first portion by biting the outer peripheral edge into the housing, and the contact state between the first portion of the support end surface and the housing is formed in an annular shape along the circumferential direction of the filter.
How to assemble a gas generator. a support portion for supporting the support end surface of the housing part is inclined so as to decrease in diameter as it moves away from the filter in an axial direction of the filter in the gas generator,
In assembling the filter to the housing part, the filter is assembled to the housing part such that the support end surface is supported by the housing with an outer circumferential edge of the support end surface as the first portion, and a contact state between the outer circumferential edge of the support end surface and the housing is formed in an annular shape along a circumferential direction of the filter.
A method for assembling a gas generator according to claim 9. the support end surface has a protruding portion that protrudes in an axial direction of the filter more than other portions of the support end surface,
In assembling the filter to the housing part, the filter is assembled to the housing part such that the support end surface is supported by the housing with the protruding portion as the first portion, and a contact state between the protruding portion and the housing is formed in an annular shape along a circumferential direction of the filter.
A method for assembling the gas generator according to claim 9 or 10.

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