Gas generator and method for assembling the same

Abstract

In the gas generator, a supporting end face which is at least one of the two axial end faces of the filter is supported by the housing in a state in which a first portion which is a part of the supporting end face contacts with and presses the housing, and in a state in which a second portion which is a portion of the supporting end face other than the first portion is separated from the housing, and the contact state between the first portion of the supporting end face and the housing is formed in an annular shape along the circumference of the filter.

Description

Technical Field

[0001] The present invention relates to a gas generator for generating combustion gas by burning a gas generating agent through the operation of an ignition unit and a method for assembling the gas generator. Background Art

[0002] In the past, a gas generator has been widely used. The gas generator fills a combustion chamber formed in a housing with a gas generating agent, burns the gas generating agent through an igniter, thereby generating combustion gas, and discharges the combustion gas to the outside from a gas discharge hole provided in the housing. In addition, in such a gas generator, in order to cool the generated combustion gas and capture the residue, a cylindrical filter is sometimes arranged between the combustion chamber and the gas discharge hole. The two axial ends of the filter are contact-supported in the housing so that all the combustion gas passes through the filter.

[0003] In this regard, Patent Documents 1 and 2 disclose a gas generator having a structure for suppressing a so-called "short pass" in which a portion of the combustion gas does not pass through the filter and reaches the gas discharge hole. The gas generator disclosed in Patent Document 1 suppresses short circuits by fixing the end face of the filter to the housing by assembling a fixing member to the end face of the filter. In addition, the gas generator disclosed in Patent Document 2 forms a bent portion in the portion of the filter that contacts the housing, and the end face of the filter is pressed against the housing by the elastic force of the bent portion, thereby suppressing short circuits.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: International Publication No. 2002 / 083464

[0007] Patent Document 2: Japanese Patent Application Publication No. 2010-234843 Summary of the invention

[0008] Problem that the invention aims to solve

[0009] However, the above-mentioned techniques cannot be said to have a sufficient effect of suppressing short circuits, and a technique capable of suppressing short circuits more effectively has been demanded.

[0010] The technology disclosed in the present invention has been accomplished in view of the above-mentioned actual situation, and an object thereof is to provide a technology capable of effectively suppressing a short circuit in a gas generator.

[0011] Technical Solution

[0012] In order to solve the above-mentioned problems, the technology disclosed in the present invention adopts the following structure. That is, the technology disclosed in the present invention is a gas generator, which comprises: a combustion chamber, which is provided with an ignition part and a gas generating agent that burns through the operation of the ignition part; a shell, which delimits the combustion chamber, and the shell includes 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, and a gas exhaust hole that connects the combustion chamber with the outside of the shell is formed in the peripheral wall portion; and a filter, which is formed in a cylindrical shape, and the filter is arranged between the gas generating agent in the combustion chamber and the gas exhaust hole in a manner of surrounding the gas generating agent, and one axial end thereof The first end face is supported by the housing on the side of the first wall portion, and the other end face is supported by the housing on the side of the second wall portion. In the gas generator, with respect to a supporting end face which is at least one of the two axial end faces of the filter, the supporting end face is supported by the housing in a state in which a first portion which is a part of the supporting end face contacts with and presses the housing, and in a state in which a second portion which is a portion of the supporting end face other than the first portion is separated from the housing, and the contact state between the first portion of the supporting end face and the housing is formed in an annular shape along the circumferential direction of the filter.

[0013] In the gas generator of the present disclosure constructed as described above, the support end face is supported on the housing at a first portion, and the first portion presses the housing, so that the load is concentrated on the first portion. Therefore, compared with the case where the support end face is supported on the housing with the entire surface, the first portion of the support end face is in stronger contact with the housing. In addition, the contact state between the first portion and the housing is formed into a ring shape along the circumference of the filter, so that a gap for the combustion gas to pass from the inner peripheral surface side to the outer peripheral surface side of the filter is not formed between the support end face and the housing. Therefore, according to the gas generator of the present disclosure, short circuits can be effectively suppressed.

[0014] Furthermore, in the gas generator disclosed herein, the housing may have a support portion supporting the support end surface that is 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.

[0015] Thus, by inclining the support portion as described above, the support end surface can be supported by the outer peripheral edge thereof on the housing, and the outer peripheral edge of the support end surface can be brought into strong contact with the housing.

[0016] In addition, in the gas generator disclosed herein, the support end surface may have a protrusion, which is an annular portion that protrudes along the axial direction of the filter more than other portions of the support end surface, and the support end surface supports the protrusion as the first portion on the housing.

[0017] Thus, by forming the above-described protruding portion on the support end surface, the support end surface can be supported by the housing via the protruding portion, and the protruding portion can be brought into strong contact with the housing.

[0018] Moreover, in the gas generator disclosed in the present invention, the ignition portion may be fixed to the second wall portion, at least the other end face of the two end faces of the filter may be the supporting end face, and the peripheral wall portion may include: a cylindrical large diameter portion located on the first wall portion side and formed with the gas discharge hole; a cylindrical small diameter portion located on the second wall portion side and formed with a diameter smaller than the large diameter portion; and an annular connecting portion connecting the large diameter portion and the small diameter portion, and in the outer casing, the supporting portion supporting the other end face of the filter is included in the connecting portion.

[0019] In the gas generator, the combustion gas flows toward the gas discharge hole, so there is a tendency that most of the combustion gas passing through the filter passes through the portion near the gas discharge hole in the filter, and the combustion gas passing through the portion farther from the gas discharge hole is less. Therefore, for the gas generator in which the gas discharge hole is formed on the first wall side of the peripheral wall portion, in the case where the filter is provided across from the first wall portion to the second wall portion, the portion near the second wall portion far from the gas discharge hole in the filter becomes a portion through which the combustion gas hardly passes and hardly contributes to the cooling and filtering of the combustion gas. In contrast, in the gas generator of the present disclosure, the support portion supporting the other end surface of the filter is included in the connecting portion, and the connecting portion is located between the first wall portion and the second wall portion in the axial direction of the peripheral wall portion. That is, the filter does not extend to the vicinity of the second wall portion through which the combustion gas hardly passes. Therefore, according to such a gas generator, the filter can be used more efficiently than in the case where the filter is provided across from the first wall portion to the second wall portion. That is, the cooling and filtering functions of the combustion gas can be fully ensured, and the filter can be made compact, which can contribute to the low weight and low cost of the filter.

[0020] Furthermore, in the gas generator of the present disclosure, the other end surface of the filter may be supported by the housing in such a manner that a groove opening toward the radially inner side of the filter is formed between the second portion and the connecting portion.

[0021] Thus, by forming the grooves that open radially inwardly of the filter, the combustion gas residues can be captured in the grooves when the combustion gas flows toward the gas discharge hole. This can improve the combustion residue capture performance.

[0022] Furthermore, in the above-described gas generator, an inner peripheral surface of the filter may be located radially inward of the small diameter portion relative to an inner peripheral surface of the small diameter portion.

[0023] Thus, the other end surface of the filter protrudes radially inwardly from the smaller diameter portion of the peripheral wall, and the residue of the combustion gas is easily captured by the other end surface and the groove of the filter. In other words, the other end surface and the groove of the filter can be more effectively utilized in capturing the residue of the combustion gas.

[0024] Moreover, in the gas generator disclosed in the present invention, a cylindrical inner cylinder member may be arranged in the combustion chamber in a manner surrounding the ignition part, whereby an ignition chamber containing an ignition powder is formed between the ignition part and the inner cylinder member, wherein the ignition powder is burned by the operation of the ignition part to cause the gas generating agent to burn, and a connecting hole is formed in the inner cylinder member for connecting the inside and outside of the ignition chamber at least when the ignition part is operating, and the connecting hole is located between the second wall portion and the other end face of the filter in the axial direction of the filter.

[0025] The gas generator is ignited by the combustion gas of the explosive sprayed from the connecting hole. Therefore, by making the connecting hole between the second wall portion and the other end face of the filter, the gas generator in the combustion chamber first burns from the gas generator located between the second wall portion and the other end face of the filter. Thus, the flow of the combustion gas is formed in such a way that the combustion gas of the gas generator flows into the above-mentioned groove. As a result, the residue of the combustion gas can be easily captured.

[0026] Furthermore, in the gas generator of the present disclosure, both end surfaces of the filter in the axial direction may serve as the supporting end surfaces.

[0027] That is, one end face and the other end face of the filter may be partially supported on the housing, and the contact state with the housing may be formed into a ring along the circumference of the filter. Thus, a gap may be prevented from forming between the two end faces of the filter and the housing, and short circuit may be more effectively suppressed.

[0028] In addition, the technology disclosed in the present invention can also be understood from the aspect of the method for assembling a gas generator. That is, the technology disclosed in the present invention is a method for assembling a gas generator, wherein the gas generator comprises: a combustion chamber, which is provided with an ignition portion and a gas generating agent that burns through the operation of the ignition portion; a housing, which delimits the combustion chamber, the housing comprising 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, wherein a gas discharge hole that connects the combustion chamber with the outside of the housing is formed in the peripheral wall portion; and a filter, which is formed in a cylindrical shape, and is arranged between the gas generating agent in the combustion chamber and the gas discharge hole in a manner that surrounds the gas generating agent, and one axial end face of the filter is supported on the first wall portion side. The filter is installed on the housing part in a manner such that a first portion which is a part of the supporting end face contacts with the housing and presses the housing, and a second portion which is a portion other than the first portion is separated from the housing, and the contact state of the first portion of the supporting end face with the housing forms a ring shape along the circumference of the filter.

[0029] Moreover, in the assembly method disclosed in the present invention, it may be that, in the housing part, the supporting portion supporting the supporting end face is inclined in a manner that decreases in diameter as it moves away from the filter in the axial direction of the filter in the gas generator, and in the process of installing the filter on the housing part, the filter is installed on the housing part in a manner that the outer peripheral edge of the supporting end face is supported on the housing by the supporting end face as the first part, and the contact state between the outer peripheral edge of the supporting end face and the housing is formed into a ring shape along the circumferential direction of the filter.

[0030] In addition, in the assembly method disclosed in the present invention, the supporting end face may have a protrusion, and the protrusion protrudes more along the axial direction of the filter than other parts of the supporting end face. During the process of installing the filter on the housing part, the filter is installed on the housing part in such a manner that the supporting end face supports the protrusion as the first part on the housing, and the contact state between the protrusion and the housing is formed into a ring shape along the circumference of the filter.

[0031] Effects of the Invention

[0032] According to the present disclosure, it is possible to more effectively suppress short-circuiting of combustion gas in a gas generator including a filter. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 This is an axial cross-sectional view of the gas generator according to Embodiment 1.

[0034] Figure 2 yes Figure 1 An enlarged view of the vicinity of the contact portion between the lower end surface of the filter and the annular wall portion of the housing.

[0035] Figure 3 This is an end view of the filter in the gas generator according to Embodiment 1 as viewed from the lower end side.

[0036] Figure 4 This is a flowchart of the method for assembling the gas generator according to the first embodiment.

[0037] Figure 5 FIG. (1) is a diagram for explaining the filter installation process according to the first embodiment.

[0038] Figure 6 FIG. (2) is a diagram for explaining the filter installation process of the first embodiment.

[0039] Figure 7 This is an axial cross-sectional view of a gas generator according to Modification 1 of Embodiment 1.

[0040] Figure 8 This is an axial cross-sectional view of a gas generator according to a second modification of the first embodiment.

[0041] Fig. 9 This is an axial cross-sectional view of a gas generator according to a third modification of the first embodiment.

[0042] Fig.10 This is an axial cross-sectional view of the gas generator according to the second embodiment.

[0043] Fig.11 This is an end view of the filter in the gas generator according to the second embodiment as viewed from the lower end side.

[0044] Fig.12 (A) and Fig.12 (B) is a diagram for explaining an example of a method for manufacturing a filter according to the second embodiment.

[0045] Fig.13 This is an axial cross-sectional view of the gas generator according to the third embodiment.

[0046] Fig.14 It is a diagram showing a modified example of the support of the filter. DETAILED DESCRIPTION

[0047] Hereinafter, the gas generator of the embodiment of the present disclosure will be described with reference to the accompanying drawings. It should be noted that each structure and combination thereof in each embodiment is an example, and the addition, omission, replacement and other changes of the structure can be appropriately made within the scope of the main purpose of the present invention. The present disclosure is not limited by the embodiment, but only by the claims.

[0048] <Implementation Method 1>

[0049] Figure 1 FIG. 2 is an axial cross-sectional view of gas generator 100 according to Embodiment 1. Figure 1 , a state before the operation of the gas generator 100 is shown. The gas generator 100 is, for example, an airbag gas generator used in an airbag.

[0050] [Overall composition]

[0051] like Figure 1 As shown, the gas generator 100 includes an ignition device 4, an inner cylinder member 5, a filter 6, an explosive 110, a gas generator 120, and a housing 1 that accommodates them. The gas generator 100 is configured as a so-called single-stage gas generator that only has one ignition device. In addition, the gas generator 100 is configured so that the gas generator 120 is burned by operating the igniter 41 included in the ignition device 4, and the combustion gas as its combustion product is discharged from the gas discharge hole 11 formed in the housing 1. The following describes the various structures of the gas generator 100. It should be noted that in this specification, for convenience, the operation of the igniter included in the ignition device (ignition unit) is sometimes expressed as "gas generator operation" or "ignition device (ignition unit) operation".

[0052] [shell]

[0053] The housing 1 is a member that defines a combustion chamber 10, which is a space in which an ignition device 4, an inner cylinder member 5, a filter 6, an explosive 110, and a gas generator 120 are arranged. In the housing 1, an upper shell 2 and a lower shell 3 made of metal, each of which is formed into a roughly cylindrical shape with a bottom, are joined so that their open ends face each other, thereby forming a short cylindrical shape with both ends of the axial direction closed. Here, the direction along the axial direction of the housing 1 is defined as the up-down direction of the gas generator 100, and the upper shell 2 side (i.e., Figure 1 The upper side of the gas generator 100 is set as the upper side of the gas generator 100, and the lower shell 3 side (that is, Figure 1 The lower side in the figure) is set as the lower side of the gas generator 100.

[0054] The upper shell 2 is a part that constitutes a part of the outer shell 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 an internal space is formed by them. The opening of the upper shell 2 is formed by the lower end of the upper peripheral wall portion 21. The lower end of the upper peripheral wall portion 21 is connected to a joint portion 23 extending radially outward. The lower shell 3 is a part that constitutes a part of the outer shell 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 fixes the ignition device 4, and an internal space is formed by them. The opening of the lower shell 3 is formed by the upper end of the lower peripheral wall portion 31. The upper end of the lower peripheral wall portion 31 is connected to a joint portion 33 extending radially outward. The lower case 3 corresponds to the “housing component” of the present disclosure.

[0055] The joint portion 23 of the upper shell 2 and the joint portion 33 of the lower shell 3 are overlapped and joined by laser welding or the like, thereby forming a short cylindrical shell 1 with both ends of the axial direction closed. The only parts where the upper shell 2 and the lower shell 3 are joined are the joint portions 23 and 33. The cylindrical peripheral wall portion 12 that connects the top plate portion 22 and the bottom plate portion 32 is formed by the upper peripheral wall portion 21 of the upper shell 2 and the lower peripheral wall portion 31 of the lower shell 3. In other words, the shell 1 is configured to include: a cylindrical peripheral wall portion 12; a top plate portion 22, which is provided on one end side of the peripheral wall portion 12; and a bottom plate portion 32, which is provided on the other end side and has an ignition device 4 fixed thereto. The combustion chamber 10 is defined by these top plate portion 22, bottom plate portion 32 and peripheral wall portion 12. The top plate portion 22 is equivalent to the "first wall portion" of the present disclosure. In addition, the bottom plate portion 32 is equivalent to the "second wall portion" of the present disclosure. In addition, a plurality of gas discharge holes 11 are formed in parallel along the circumferential direction on the upper peripheral wall portion 21 of the peripheral wall portion 12 to connect the combustion chamber 10 with the external space of the housing 1. Before the ignition device 4 is operated, the gas discharge holes 11 are closed by a sealing tape (not shown).

[0056] Here, if Figure 1As shown, the lower circumferential 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 circumferential wall portion 31, and is formed to have a diameter substantially equal to that of the upper circumferential wall portion 21. The second cylindrical wall portion 312 is a cylindrical portion including the lower end portion of the lower circumferential 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 with the upper end portion of the second cylindrical wall portion 312. That is, in the axial direction of the circumferential wall portion 12, the annular wall portion 313 is located midway in the circumferential wall portion 12, and is located between the top plate portion 22 and the bottom plate portion 32. In addition, as Figure 1 As shown, the annular wall portion 313 is inclined in a manner that the diameter decreases as it moves toward the bottom plate portion 32 side. Here, the structure of the peripheral wall portion 12 including the upper peripheral wall portion 21 and the first cylindrical wall portion 311 is equivalent to the "large diameter portion" of the present disclosure, the second cylindrical wall portion 312 is equivalent to the "small diameter portion", and the annular wall portion 313 is equivalent to the "connecting portion". That is, the large diameter portion is a part of the peripheral wall portion 12, which is a cylindrical part located on the top plate portion 22 side and formed with the gas discharge hole 11. In addition, the small diameter portion is a part of the peripheral wall portion 12, which is located on the bottom plate portion 32 side and is formed into a cylindrical part with a smaller diameter than the large diameter portion. In addition, the connecting portion is an annular part connecting the large diameter portion and the small diameter portion. It should be noted that in this example, the large diameter portion is formed by all the upper peripheral wall portions 21 and a part of the lower peripheral wall portion 31, and the small diameter portion and the connecting portion are formed by a part of the lower peripheral wall portion 31, but the present disclosure is not limited to this. The present disclosure only needs to form a large diameter portion, a small diameter portion and a connecting portion on the peripheral wall 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 connecting portion may be formed only by the lower peripheral wall portion 31 .

[0057] [Ignition device]

[0058] like Figure 1As shown, the ignition device 4 includes an igniter 41, a collar 42 and a resin portion 43, and the ignition device 4 is fixed to the bottom plate portion 32 of the lower shell 3. The ignition device 4 is equivalent to the "ignition portion" of the present disclosure. The igniter 41 has: a metal cup body 411, which contains a primer; and a pair of current-carrying pins 412, 412, which are used to receive the supply of current from the outside. The igniter 41 is operated by the ignition current supplied to the pair of current-carrying pins 412, 412, thereby causing the primer to burn and discharging its combustion products 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 where it is pressed into the assembly hole 32a formed in the bottom plate portion 32. The resin portion 43 is a resin member that is fixed to the collar 42 by being sandwiched between the igniter 41 and the collar 42. The resin portion 43 covers the lower portion of the igniter 41 and engages with the collar 42, thereby fixing the igniter 41 relative to the collar 42 in a manner that at least a portion of the cup body 411 is exposed from the resin portion 43. However, the entire cup body 411 may be over-molded by the resin portion 43. That is, the entire cup body 411 may also be in a state covered by resin. In addition, the resin portion 43 forms a connector insertion space on the inner side of the collar 42 into which a connector (not shown) can be inserted, and the connector supplies electricity from an external power source to a pair of power pins 412, 412. The resin portion 43 covers and holds a portion of the pair of power pins 412, 412 in a manner that the lower ends of the pair of power pins 412, 412 are exposed to the connector insertion space. The pair of power pins 412, 412 are insulated from each other by the resin portion 43. It should be noted that the fixation of the igniter 41 to the collar 42 and the relationship between the collar 42 and the bottom plate portion 32 are not limited to Figure 1 , known techniques may be used.

[0059] [Inner cylinder member]

[0060] The inner cylinder member 5 is a cylindrical member extending from the bottom plate portion 32 toward the top plate portion 22 in a manner of surrounding the ignition device 4. The inner cylinder member 5 is formed into a cylindrical shape with one end (upper end) closed and the other end (lower end) open, and is assembled to the bottom plate portion 32 by inserting (pressing) a collar 42 at its lower end. The inner cylinder member 5 is arranged between the ignition device 4 and the gas generating agent 120, and a ignition chamber 51 is formed between the inner cylinder member 5 and the ignition device 4, and the ignition chamber 51 is a space for accommodating the ignition powder 110. The ignition powder 110 is burned by the operation of the igniter 41 to generate combustion gas, etc. In addition, a plurality of communication holes 52 are formed in the inner cylinder member 5 to connect its internal space (i.e., the ignition chamber 51) with the external space. In the state before the ignition device 4 is operated, the communication hole 52 is blocked by a sealing tape (not shown), and when the ignition device 4 is operated, the sealing tape is cracked by the pressure of the combustion gas, and the inside of the ignition chamber 51 is connected with the outside. It should be noted that the communicating hole 52 only needs to communicate the inside and outside of the ignition chamber 51 at least when the ignition device 4 is in operation, and it does not need to be blocked by the sealing tape.

[0061] [Filter]

[0062] The filter 6 is a cylindrical member formed of a metal material and has a plurality of holes. Figure 1 As shown, the filter 6 is arranged in the combustion chamber 10 in such a manner 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 arranged between the gas generating agent 120 and the gas discharge hole 11 in the combustion chamber 10 in such a manner as to surround the gas generating agent 120. The two end faces of the filter 6 in the axial direction are formed as flat faces. One end face (the upper end face indicated by the reference numeral 61) of the two end faces is supported by the housing 1 on the upper shell 2 side, and the other end face (the lower end face indicated by the 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. It should be noted that a known sealing unit can also be arranged 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 (that is, the axial direction of the peripheral wall portion). In this example, the lower end face 62 of the filter 6 is equivalent to the "supporting end face" of the present disclosure. The filter 6 is supported by the housing 1 in a state where a load is applied in the axial direction.

[0063] The filter 6 of this example has a multi-layer structure. A porous metal plate is overlapped in the radial direction (wound into 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, punched metal, and the like. Since a plurality of holes are formed in the filter 6, the combustion gas of the gas generating agent 120 disposed in the combustion chamber 10 can pass through the filter 6. When the combustion gas passes through the filter 6, the filter 6 cools the combustion gas by taking away the heat of the combustion gas. In addition, the filter 6 not only has the above-mentioned combustion gas cooling function, but also has the function of filtering the combustion gas by capturing the combustion residues contained in the combustion gas. It should be noted that Figure 1 In the figure, reference numeral 63 indicates the inner peripheral surface of the filter 6, and reference numeral 64 indicates the outer peripheral surface of the filter 6. It should be noted that, as described later, the filter 6 may use other well-known filters.

[0064] [Gunpowder]

[0065] As the primer 110, in addition to the known black powder, a gas generating agent having good ignition performance and a combustion temperature higher than that of the gas generating agent 120 can be used. The combustion temperature of the primer 110 can be set in the range of 1700° C. to 3000° C. As such a primer 110, a known primer containing, for example, nitroguanidine (34% by weight) and strontium nitrate (56% by weight) can be used. In addition, the primer 110 can be in various shapes such as granular, pellet, cylindrical, and disc shapes.

[0066] [Gas generating agent]

[0067] As the gas generating agent 120, a gas generating agent with a relatively low combustion temperature can be used. The combustion temperature of the gas generating agent 120 can be set in the range of 1000°C to 1700°C. As such a gas generating agent 120, for example, a known gas generating agent containing guanidine nitrate (41% by weight), basic copper nitrate (49% by weight), a binder, and an additive can be used. In addition, for example, various shapes such as granular, pellet, cylindrical, and disc can be used for the gas generating agent 120.

[0068] [action]

[0069] Next, the operation of the gas generator 100 according to the first embodiment will be described. Figure 1, while explaining. When the sensor (not shown) senses the impact, the ignition current is supplied to a pair of energized pins 412, 412, and the igniter 41 works. Then, the detonator contained in the cup body 411 of the igniter 41 burns, and the flame, high-temperature gas, etc. as its combustion products are discharged to the outside of the cup body 411. As a result, the explosive 110 contained in the ignition chamber 51 burns, generating combustion gas. The combustion gas of the explosive 110 destroys the sealing band that blocks the connecting hole 52 and is discharged from the connecting hole 52 to the outside of the ignition chamber 51. Then, the combustion gas of the explosive 110 contacts the gas generator 120, and the gas generator 120 is ignited. The gas generator 120 burns, thereby generating high-temperature and high-pressure combustion gas in the combustion chamber 10. The combustion gas passes through the filter 6, whereby the combustion gas is cooled and the combustion residue is captured. The combustion gas of the gas generating agent 120 cooled and filtered by the filter 6 passes through the gap 13, destroys 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. The combustion gas of the gas generating agent 120 flows into the airbag (not shown) after being discharged to the outside of the housing 1. The airbag expands, thereby forming a buffer between the occupant and the hard structure, protecting the occupant from impact.

[0070] [Filter support]

[0071] like Figure 1 As shown, in gas generator 100 , lower end surface 62 is supported by annular wall portion 313 so as to be divided into a portion in contact with annular wall portion 313 and a portion separated from annular wall portion 313 in the radial direction of filter 6 . Figure 1 The reference numeral 62a shown in the figure represents the outer peripheral edge of the lower end face 62 of the filter 6. In addition, the reference numeral 62b represents the portion of the lower end face 62 other than the outer peripheral edge 62a, that is, the portion on the inner side of the outer peripheral edge 62a, which is referred to as the non-peripheral portion. The outer peripheral edge 62a of the filter 6 is equivalent to the "first portion" of the present disclosure. In addition, the non-peripheral portion 62b of the filter 6 is equivalent to the "second portion" of the present disclosure. In addition, the reference numeral 313a represents the surface of the annular wall portion 313 that defines one side of the combustion chamber 10, which is referred to as the annular wall surface. That is, the annular wall surface 313a is the surface in the housing 1 that supports the lower end face 62 of the filter 6. The annular wall surface 313a is equivalent to the "supporting portion" of the present disclosure.

[0072] like Figure 1As shown, the annular wall surface 313a is inclined in a manner that the diameter decreases as it moves away from the filter 6 in the axial direction of the filter 6. Therefore, the lower end surface 62 is supported on the annular wall portion 313 in a state where the outer peripheral edge 62a as a part thereof is in contact with the annular wall portion 313 and in a state where the non-peripheral portion 62b is separated from the annular wall portion 313. In other words, the lower end surface 62 is supported on the housing 1 with the outer peripheral edge 62a as a part thereof. In addition, as described above, the filter 6 is in a state where a load is applied in the axial direction by the housing 1, so the outer peripheral edge 62a of the filter 6 presses the housing 1. The lower end surface 62 is supported on the annular wall portion 313 by the outer peripheral edge 62a, and the outer peripheral edge 62a presses the annular wall portion 313, whereby the load is concentrated on the outer peripheral edge 62a. Therefore, compared with the case where the entire surface of the lower end surface 62 including the non-peripheral portion 62b is supported on the annular wall portion 313, the outer peripheral edge 62a of the lower end surface 62 is in strong contact with the annular wall portion 313 (that is, the filter 6 is in a state where the load on the outer peripheral edge 62a is concentrated on the annular wall surface 313a). Figure 2 yes Figure 1 FIG. 1 is an enlarged view of the vicinity of the contact portion between the lower end surface 62 of the filter 6 and the annular wall portion 313 of the housing 1. Figure 2 As shown, in the gas generator 100, the load is concentrated on the outer peripheral edge 62a of the lower end surface 62, and thus the outer peripheral edge 62a is embedded in the annular wall portion 313. Here, the outer peripheral edge 62a embedded in the annular wall portion 313 refers to a state in which the corner of the outer peripheral edge 62a (the corner defined by the outer peripheral surface 64 and the lower end surface 62) enters the annular wall surface 313a even if it is a small amount. In other words, it may also refer to a state in which the annular wall portion 313 is deformed in a manner to accommodate the corner of the outer peripheral edge 62a even if it is a small amount. At this time, the outer peripheral edge 62a embedded in the annular wall portion 313 does not have to be deformed. In addition, Figure 3 This is an end view of the filter 6 in the gas generator 100 of the first embodiment as viewed from the lower end side. Figure 3 As shown, the outer peripheral edge 62a in the gas generator 100 that contacts the annular wall portion 313 of the housing 1 is formed in an annular shape along the circumference of the filter 6. Therefore, in the gas generator 100, the outer peripheral edge 62a of the lower end face 62 contacts the annular wall portion 313 of the housing 1, and thus their contact state is formed in an annular shape along the circumference of the filter 6. In other words, the contact state between the lower end face 62 of the filter 6 and the housing 1 is formed over the entire circumference of the lower end face 62. It should be noted that the hardness of the housing 1 (annular wall portion 313) and the hardness of the filter 6 can also be different. For example, in the case where the filter 6 is harder than the annular wall portion 313, Figure 1In the state, the outer peripheral edge 62a is annularly embedded in the annular wall portion 313. On the contrary, 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 to increase the contact area with the annular wall surface 313a.

[0073] [How to assemble the gas generator]

[0074] Next, a description will be given of a method for assembling the gas generator according to Embodiment 1. However, the method for assembling the gas generator of the present disclosure is not limited to the following method. Figure 4 1 is a flowchart of a method for assembling the gas generator 100 according to the first embodiment. Figure 4 To explain.

[0075] First, in the preparation process of step S101 , the upper case 2 , the lower case 3 (housing parts), the ignition device 4 , the inner cylinder member 5 , and the filter 6 are prepared.

[0076] Next, in the ignition device assembly process of step S102, the ignition device 4 is assembled to the lower case 3. In step S102, the ignition device 4 is inserted from the opening of the lower case 3. The ignition device 4 is fixed to the lower case 3 by welding to the bottom plate portion 32 while being fitted into the assembly hole 32a.

[0077] Next, in the inner cylinder member assembly process of step S103, the inner cylinder member 5 is assembled to the lower housing 3 to which the ignition device 4 is fixed. In step S103, the ignition device 4 (more specifically, the collar 42) is inserted (pressed) from the opening of the inner cylinder member 5 filled with the transfer powder 110, thereby assembling the inner cylinder member 5 in a manner of surrounding the ignition device 4. Thus, the transfer chamber 51 is formed.

[0078] Next, in the filter mounting process of step S104 , the filter 6 is mounted concentrically on the lower housing 3 to which the inner cylinder member 5 is attached. Figure 5 and Figure 6 FIG. 1 is a diagram for explaining the filter installation process of Embodiment 1. In step S104, first, Figure 5 As shown in FIG. 1 , the filter 6 is inserted from the opening of the lower housing 3 so that the lower end surface 62 of the filter 6 contacts the annular wall portion 313 of the lower housing 3. Here, as described above, the annular wall surface 313a of the annular wall portion 313 is inclined so as to decrease in diameter as it moves away from the filter 6 in the axial direction of the filter 6. Figure 5As shown in FIG. 1 , the lower end surface 62 of the filter 6 is in a state where the outer peripheral edge 62a is in contact with the annular wall surface 313a and the non-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 circumference of the filter 6. In step S104, the gas generating agent 120 is then filled into the inner side of the filter 6. In step S104, as shown in FIG. Figure 6 As shown, the upper shell 2 is assembled to the lower shell 3, thereby forming the housing 1. 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, in the housing 1, the contact parts of the upper shell 2 and the lower shell 3 are joined by a joining method (for example, welding, etc.) that is preferred for moisture-proofing of the gas generating agent filled inside. In step S104, the upper shell 2 is assembled in a manner that the top plate portion 22 of the upper shell 2 is in contact with the upper end surface 61 of the filter 6. The filter 6 is in a state where it is clamped from both sides of 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. As described above, the lower end surface 62 of the filter 6 is supported by the annular wall portion 313, and the gas generator 100 is assembled.

[0079] [Function, Effect]

[0080] In addition, in the gas generator, when the gas generating agent burns and generates combustion gas in the combustion chamber, a radially outward load acts on the filter due to the pressure of the combustion gas. If the end of the filter moves away from the housing due to the load acting radially outward, 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 not pass through the filter but pass through the gap and reach the gas discharge hole. In other words, there is a fear that a so-called "short circuit" will occur.

[0081] 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 in a state where the outer peripheral edge 62a as a part thereof contacts and presses the annular wall portion 313, and in a state where the non-peripheral portion 62b as a portion of the lower end surface 62 other than the outer peripheral edge 62a is separated 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 an annular shape along the circumferential direction of the filter 6.

[0082] Thus, by supporting the lower end face 62 with the outer peripheral edge 62a and concentrating the load on the outer peripheral edge 62a, the outer peripheral edge 62a can be brought into strong contact with the housing 1. In addition, by forming the contact state between the outer peripheral edge 62a and the housing 1 into an annular shape along the circumferential direction of the filter 6, a gap through which the combustion gas passes from the inner peripheral surface 63 side to the outer peripheral surface 64 side of the filter 6 is not formed between the lower end face 62 and the housing 1. Thus, according to the gas generator 100, short circuiting can be effectively suppressed.

[0083] Furthermore, 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, so that a gap is less likely to be formed, and a short circuit is effectively suppressed. It should be noted that as long as the outer peripheral edge 62a of the lower end surface 62 and the annular wall portion 313 are in contact with each other over the entire circumference of the lower end surface 62, the outer peripheral edge 62a may not be embedded in the annular wall portion 313 of the housing 1.

[0084] In gas generator 100, annular wall surface 313a supporting lower end surface 62 in housing 1 is inclined so as to decrease in diameter as moving away from filter 6 in the axial direction of filter 6. Thus, lower end surface 62 can be supported by housing 1 at outer peripheral edge 62a.

[0085] Here, in the gas generator, the combustion gas flows toward the gas discharge hole, so there is a tendency that most of the combustion gas that passes through the filter passes through the portion near the gas discharge hole in the filter, and the combustion gas that passes through the portion farther from the gas discharge hole is less. Therefore, in the case of a gas generator such as the gas generator 100 in which the gas discharge hole is formed on the top plate side of the peripheral wall, when the filter is provided from the top plate to the bottom plate, the portion near the bottom plate far from the gas discharge hole in the filter becomes a portion through which the combustion gas hardly passes and hardly contributes to the cooling and filtering of the combustion gas.

[0086] In contrast, in the gas generator 100, the lower end face 62 is supported by the annular wall surface 313a included in the annular wall portion 313. As described above, in the axial direction of the peripheral wall portion 12, the annular wall portion 313 is located between the top plate portion 22 and the bottom plate portion 32. That is, the filter 6 whose lower end face 62 is supported by the annular wall portion 313 is in a state of being biased toward the top plate portion 22 side, and does not extend to the vicinity of the bottom plate portion 32 through which the combustion gas hardly passes. Therefore, in the gas generator 100, the filter 6 can be used more efficiently than in the case where the upper end face of the filter is supported by the top plate portion and the lower end face is supported by the bottom plate portion. That is, the cooling and filtering functions of the combustion gas can be fully ensured, and the filter can be made compact, which can contribute to the low weight and low cost of the filter.

[0087] Here, if Figure 1As shown in FIG. 1 , in the gas generator 100, the lower end surface 62 of the filter 6 is supported on the housing 1 in such a manner that the outer peripheral edge 62a contacts the annular wall portion 313 and a groove indicated by the reference numeral G1 is formed between the non-peripheral portion 62b and the annular wall portion 313. The groove G1 opens annularly toward the radial inner side of the filter 6. Therefore, when the combustion gas flows toward the gas discharge hole 11, the residue of the combustion gas is easily accumulated in the groove G1. As a result, the performance of capturing the combustion residue can be improved.

[0088] In addition, if Figure 1 As shown, a connecting hole 52 is formed in the inner cylinder member 5 of the gas generator 100 for connecting the inside and outside of the ignition chamber 51 at least when the ignition device 4 is working. In the axial direction of the filter 6, the connecting hole 52 is located between the bottom plate portion 32 and the lower end surface 62 of the filter 6. The gas generating agent 120 is ignited by the combustion gas of the ignition powder 110 ejected from the connecting hole 52. Therefore, by locating the connecting 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 first burns from the gas generating agent 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 located in the middle thereof functions as a residue capture pocket, and it is easy to capture the residue of the combustion gas. It should be noted that, in addition to having Figure 1 The connecting hole 52 shown may also have connecting holes at other positions.

[0089] Moreover, it is also possible to use a compression molded filter such as the one disclosed in Japanese Patent Gazette No. 10-119705 or a winding filter such as the one disclosed in Japanese Patent Gazette No. 11-348712 as the filter 6, and configure the filter 6 in such a manner that the groove G1 is formed by the non-peripheral portion 62b and the annular wall portion 313 by strongly pressing and deforming the annular wall portion 313 through the outer peripheral edge 62a.

[0090] [Variation of Embodiment 1]

[0091] Hereinafter, a gas generator according to a modified example of the first embodiment will be described. Figure 1 to Figure 6 The description will focus on the differences between the gas generator 100 described above, and the same points as those of the gas generator 100 are denoted by the same reference numerals, and detailed description thereof will be omitted.

[0092] [Variation 1 of Implementation Example 1]

[0093] Figure 7 FIG. 1 is an axial cross-sectional view of a gas generator 100A according to a first modification of the first embodiment. Figure 7, the state of the gas generator 100A before operation is shown. Figure 7 As shown, in the gas generator 100A, the filter 6 is supported on the housing 1 in such a manner that the inner peripheral surface 63 of the filter 6 is located radially inward of the second cylindrical wall portion 312 relative to the inner peripheral surface 312a of the second cylindrical wall portion 312 of the lower peripheral wall portion 31. As a result, the lower end surface 62 of the filter 6 protrudes radially inward relative to the second cylindrical wall portion 312 of the lower peripheral wall portion 31, and the residue of the combustion gas is easily captured by the lower end surface 62 of the filter 6 and the groove G1. In other words, the lower end surface 62 of the filter 6 can be more effectively utilized in capturing the residue of the combustion gas.

[0094] [Variation 2 of Implementation Example 1]

[0095] Figure 8 FIG. 2 is an axial cross-sectional view of a gas generator 100B according to a second modification of the first embodiment. Figure 8 , a state of the gas generator 100B before operation is shown. In the gas generator 100B, both the upper end surface 61 and the lower end surface 62 of the filter 6 correspond to the "support end surface" of the present disclosure.

[0096] like Figure 8 As shown in FIG. 1 , in the gas generator 100B, similarly to 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 in a state where the outer peripheral edge 62a contacts and presses the annular wall portion 313 and in a state where the non-peripheral portion 62b is separated from the annular wall portion 313. In addition, the contact state between the outer peripheral edge 62a of the filter 6 and the annular wall portion 313 is formed in an annular shape along the circumferential direction of the filter 6. Moreover, in the gas generator 100B, the upper end surface 61 of the filter 6 is also supported by the housing 1 using the outer peripheral edge 61a as a part thereof.

[0097] like Figure 8 As shown, 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 defining the upper end of the combustion chamber 10, and extends in the radial direction of the filter 6 in a manner orthogonal 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, is connected to the upper peripheral wall portion 21, and is inclined in a manner that the diameter decreases as it moves away from the filter 6 in the axial direction of the filter 6.

[0098] Figure 8The reference numeral 61a shown in the figure represents the outer peripheral edge of the upper end face 61 of the filter 6. In addition, the reference numeral 61b represents the non-peripheral portion which is a portion of the upper end face 61 except the outer peripheral edge 61a. In addition, the reference numeral 222a represents the surface of the inclined wall portion 222 which delimits one side of the combustion chamber 10, which is referred to as the inclined wall surface. The inclined wall surface 222a of the inclined wall portion 222 is equivalent to the "support portion" of the present disclosure. The inclined wall surface 222a is inclined in a manner that decreases in diameter as it moves away from the filter 6 in the axial direction of the filter 6. Therefore, the upper end face 61 is supported on the housing 1 in a state where the outer peripheral edge 61a which is a part thereof contacts and presses the inclined wall portion 222 and in a state where the non-peripheral portion 61b is separated from the inclined wall portion 222. In addition, the contact state between the outer peripheral edge 61a of the filter 6 and the inclined wall portion 222 is formed in an annular shape along the circumferential direction of the filter 6.

[0099] According to the gas generator 100B, similarly to the gas generator 100, no gap is formed between the lower end surface 62 and the housing 1. Moreover, according to the gas generator 100B, the upper end surface 61 is supported by the outer peripheral edge 61a and the load is concentrated on the outer peripheral edge 61a so that the outer peripheral edge 61a is strongly in contact with the housing 1 (inclined wall portion 222), and the contact state of the outer peripheral edge 61a and the housing 1 is formed into an annular shape along the circumferential direction of the filter 6, thereby no gap is formed between the upper end surface 61 and the housing 1.

[0100] That is, according to the gas generator 100B, it is possible to prevent gaps from being formed between the both end surfaces of the filter 6 and the case 1. Therefore, according to the gas generator 100B, short circuits can be suppressed more effectively.

[0101] [Variation 3 of Implementation Example 1]

[0102] Fig. 9 FIG. 1 is an axial cross-sectional view of a gas generator 100C according to a third modification of the first embodiment. Fig. 9 , a state of the gas generator 100C before operation is shown. The gas generator 100C is different from the gas generator 100 mainly in that the lower end surface 62 of the filter 6 is supported by a part of the bottom plate instead of a part of the peripheral wall.

[0103] like Fig. 9As shown, the peripheral wall portion 12C of the gas generator 100C does not have the annular wall portion 313, and the diameter is constant from the top plate portion 22 to the bottom plate portion 32C. In addition, 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 defining the lower end of the combustion chamber 10, and extends in the radial direction of the filter 6 in a manner orthogonal 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, is connected to the lower peripheral wall portion 31, and is inclined in a manner that the diameter decreases as it moves away from the filter 6 in the axial direction of the filter 6.

[0104] Fig. 9 The reference numeral 322a shown in the figure indicates a surface of the inclined wall portion 322 that defines one side of the combustion chamber 10, which is referred to as an inclined wall surface. The inclined wall surface 322a of the inclined wall portion 322 corresponds to the "support portion" of the present disclosure. The inclined wall surface 322a is inclined in a manner that decreases in diameter as it moves away from the filter 6 in the axial direction of the filter 6.

[0105] According to gas generator 100C, similarly to gas generator 100 , no gap is formed between lower end surface 62 and housing 1 , and short circuit can be effectively suppressed.

[0106] <Implementation Method 2>

[0107] Fig.10 FIG. 2 is an axial cross-sectional view of gas generator 200 according to Embodiment 2. Fig.10 , a state before operation of the gas generator 200 is shown. Hereinafter, the gas generator 200 of the second embodiment will be described with a focus on the differences from the gas generator 100 of the first embodiment, and the same points as the gas generator 100 are given the same reference numerals and their detailed description is omitted.

[0108] like Fig.10 As shown, the lower end face 62 of the filter 6D of the gas generator 200 has a protrusion 62c, which is an annular portion that protrudes in the axial direction of the filter 6D more than other portions of the lower end face 62. The other portions of the lower end face 62 except the protrusion 62c are called non-protrusions, which are indicated by the reference numeral 62d. The protrusion 62c of 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, Fig.10 The protrusion in the example may not be formed in the outermost layer of the filter, and may be formed in the middle layer, for example. The protrusion 62c of the filter 6D corresponds to the "first part" of the present disclosure. In addition, the non-protrusion 62d of the filter 6D corresponds to the "second part" of the present disclosure.

[0109] In addition, if Fig.10As shown, the annular wall surface 313a of the annular wall portion 313D of the peripheral wall portion 12 supporting the lower end surface 62 of the filter 6D is not inclined but is a flat surface extending in the radial direction of the filter 6D so as to be orthogonal to the axial direction of the filter 6D.

[0110] In the filter 6D, the protrusion 62c protrudes in the axial direction at the lower end surface 62, so that Fig.10 As shown, the lower end face 62 of the filter 6D is supported on the annular wall portion 313D in a state where the protrusion 62c contacts and presses the annular wall portion 313D of the housing 1, and in a state where the non-protrusion 62d is separated from the annular wall portion 313D. Therefore, the load is concentrated on the protrusion 62c, and the protrusion 62c is in strong contact with the annular wall portion 313D. In the gas generator 200, the load is concentrated on the protrusion 62c of the lower end face 62, so that the protrusion 62c is embedded in the annular wall portion 313D. Here, the protrusion 62c embedded in the annular wall portion 313D refers to a state in which the protrusion 62c enters the annular wall surface 313a even if it is a small amount. In other words, it may also refer to a state in which the annular wall portion 313D is deformed in a manner to accommodate the protrusion 62c even if it is a small amount. Here, Fig.11 This is an end view of the filter 6D in the gas generator 200 of the second embodiment as viewed from the lower end side. Fig.11 As shown, the protrusion 62c in the gas generator 200 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. Therefore, in the gas generator 200, the protrusion 62c of the lower end surface 62 contacts the annular wall portion 313D of the housing 1, and thus their contact state is formed in an annular shape along the circumferential direction of the filter 6D.

[0111] According to such gas generator 200 , similarly to gas generator 100 , no gap is formed between lower end surface 62 and housing 1 , and short circuit can be effectively suppressed.

[0112] In the gas generator 200, similarly, by embedding the protrusion 62c of the filter 6D in the annular wall portion 313D of the housing 1, it is less likely to form a gap, thereby effectively suppressing a short circuit. It should be noted that as long as the contact state between the protrusion 62c of the lower end surface 62 and the annular wall portion 313D is formed over the entire circumference of the lower end surface 62, the protrusion 62c may not be embedded in the annular wall portion 313D of the housing 1. Furthermore, the annular wall portion combined with the filter 6D may also be Figure 1 The inclined annular wall portion 313 shown in the figure.

[0113] Fig.12 (A) and Fig.12 (B) is a diagram for explaining an example of a method for manufacturing the filter 6D according to the second embodiment. The filter 6D can be manufactured, for example, by Fig.12 Winding as shown in (B) Fig.12 The porous metal plate 60 shown in (A) is manufactured. Fig.12 As shown in (A), the porous metal plate 60 is formed into a long strip, and is divided into a main body 601 located at one end and a wide width portion 602 located at the other end and having a width greater than the main body 601. The wide width portion 602 is the outermost portion of the filter 6D. Fig.12 The porous metal plate 60 is wound up from the main body 601 as shown in FIG. 2 (B) to produce a filter 6D having a protrusion 62c.

[0114] Assembly method and use of gas generator 200 Figure 4 In the assembly method of the gas generator 100 described above, the filter 6D is mounted on the lower housing 3 in a manner such that the lower end surface 62 of the filter 6D is supported on the annular wall portion 313D by 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 in the filter mounting process of step S104.

[0115] <Implementation Method 3>

[0116] Fig.13 FIG. 2 is an axial cross-sectional view of a gas generator 300 according to Embodiment 3. Fig.13 , a state before the operation of the gas generator 300 is shown. Hereinafter, the gas generator 300 of the third embodiment will be described with the main focus on the differences from the gas generator 100 of the first embodiment, and the same points as the gas generator 100 are given the same reference numerals and their detailed description is omitted.

[0117] like Fig.13 As shown, the gas generator 300 includes a first ignition device 4X, a second ignition device 4Y, an inner cylinder member 5E, a filter 6, an explosive 110, a first gas generator 120X, a second gas generator 120Y, and a housing 1E for accommodating them. The gas generator 300 is configured as a so-called two-stage gas generator having two ignition devices. In the gas generator 300, the first ignition device 4X is equivalent to the "ignition unit" of the present disclosure. In addition, the gas generator 300 is configured such that the first gas generator 120X is burned by the operation of the first ignition device 4X, and the second gas generator 120Y is burned by the operation of the second ignition device 4Y, thereby discharging more combustion gas from the gas discharge hole 11. In the gas generator 300, the second ignition device 4Y operates independently of the first ignition device 4X, and when operating, it operates at a predetermined timing after the operation of the first ignition device 4X.

[0118] like Fig.13 As shown, the housing 1E of Embodiment 3 has a partition wall portion 14, which divides the internal space of the housing 1E into a first combustion chamber 10X and a second combustion chamber 10Y, and abuts against the lower end surface 62 of the support filter 6. In the axial direction of the filter 6, the partition wall portion 14 is provided between the top plate portion 22E and the bottom plate portion 32. That is, the partition wall portion 14 is provided on the other end side of the peripheral wall portion 12 relative 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. In addition, 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 is equivalent to the "first wall portion" of the present disclosure, and the partition wall portion 14 is equivalent to the "second wall portion" of the present disclosure. The first combustion chamber 10X contains a first gas generator 120X that burns when the first ignition device 4X is operated, and the second combustion chamber 10Y contains a second gas generator 120Y that burns when the second ignition device 4Y is operated. The first combustion chamber 10X corresponds to the "combustion chamber" of the present disclosure, and the first gas generator 120X corresponds to the "gas generator" of the present disclosure.

[0119] The partition wall portion 14 includes a partition wall portion 141, a fitting wall portion 142, and a terminal portion 143. The partition wall portion 141 is a portion defining the lower end of the first combustion chamber 10X, and extends in the radial direction of the filter 6 in a manner orthogonal to the axial direction of the filter 6. A through hole 14a is formed in the partition wall portion 141, and the through hole 14a is a hole for the inner cylinder member 5E to pass through. The fitting wall portion 142 is a cylindrical portion that is fitted in the lower peripheral wall portion 31 of the lower housing 3, and extends from the peripheral edge of the partition wall portion 141 along the axial direction of the filter 6 toward the inner side (i.e., the upper side) of the first combustion chamber 10X. The terminal portion 143 is an annular portion placed on the upper end of the lower peripheral wall portion 31 of the lower housing 3, and extends radially outward from the upper end of the fitting wall portion 142.

[0120] The inner cylinder member 5E of the third embodiment extends from the bottom plate portion 32 toward the top plate portion 22E in a manner of surrounding the first ignition device 4X fixed to the bottom plate portion 32, passes through the through hole 14a of the partition wall 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 in a state of being arranged in the first combustion chamber 10X. In addition, a partition member P1 is arranged inside the inner cylinder member 5E to divide its internal space up and down. Thus, the space below the partition member P1 (on the first ignition device 4X side) in the internal space of the inner cylinder member 5 is formed as a fire transfer chamber 51. The fire transfer powder 110 is accommodated in the fire transfer chamber 51 in a manner that it is not mixed with the first gas generating agent 120X. The partition member P1 is formed of a material that is rapidly burned, melted or disappeared by the combustion gas of the fire transfer powder 110 so as not to hinder the ignition of the first gas generating agent 120X by the combustion gas of the fire transfer powder 110. The inner cylinder member 5E is provided with a plurality of communication holes 52 for communicating the inner space of the inner cylinder member 5E (and thus the first combustion chamber 10X) with the second combustion chamber 10Y. Before the second ignition device 4Y is activated, the communication holes 52 are closed by a sealing tape (not shown).

[0121] like Fig.13 As shown, in the gas generator 300, the filter 6 is arranged in the first combustion chamber 10X in such a manner that the upper end surface 61 abuts against the top plate portion 22E and the lower end surface 62 abuts against the partition wall portion 141 in the partition portion 14. In addition, 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 defining the upper end of the first combustion chamber 10X, and extends in the radial direction of the filter 6 in a manner orthogonal 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 a surface on one side of the inclined wall portion 222 defining the first combustion chamber 10X, is connected to the upper peripheral wall portion 21, and is inclined in a manner that decreases in diameter as it moves away from the filter 6 in the axial direction of the filter 6.

[0122] Therefore, the upper end surface 61 of the filter 6 is supported by the housing 1E in a state where the outer peripheral edge 61a as a part thereof contacts and presses the inclined wall portion 222 and the non-peripheral portion 61b is separated from the inclined wall portion 222. Furthermore, the contact state between the outer peripheral edge 61a of the filter 6 and the inclined wall portion 222 is formed in an annular shape along the circumferential direction of the filter 6.

[0123] When such a gas generator 300 is in operation, first, the first ignition device 4X is operated, and the ignition powder 110 contained in the ignition chamber 51 of the first combustion chamber 10X is burned to generate its combustion gas. The partition member P1 is burned and removed by the combustion gas of the ignition powder 110, whereby the combustion gas comes into contact with the first gas generator 120X, and the first gas generator 120X is ignited. The first gas generator 120X is burned, thereby generating combustion gas in the first combustion chamber 10X. The combustion gas of the first gas generator 120X passes through the filter 6 and is discharged from the gas discharge hole 11 to the outside of the housing 1E. Next, the second ignition device 4Y is operated, and the second gas generator 120Y contained in the second combustion chamber 10Y is burned to generate its combustion gas. The combustion gas of the second gas generator 120Y destroys the sealing tape that blocks the connecting hole 52 and flows into the first combustion chamber 10X from the connecting hole 52, passes through the filter 6, and is discharged from the gas discharge hole 11 to the outside of the housing 1E.

[0124] According to the gas generator 300 of the third embodiment, the outer peripheral edge 61a is used to support the upper end face 61 and the load is concentrated on the outer peripheral edge 61a so that the outer peripheral edge 61a is strongly in 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, thereby no gap is formed between the upper end face 61 and the housing 1E. Therefore, according to the gas generator 300, short circuits can be effectively suppressed.

[0125] <Other embodiments>

[0126] Fig.14 FIG. 2 is a diagram showing a modified example of filter support. Fig.14 In the figure, a modified example of applying the support of the filter to Fig. 9 The case of the gas generator 100C shown in FIG. Fig.14 As shown, the lower end face 62 of the filter 6 may also be supported by an R wall portion 322C having an R (curvature) instead of the inclined wall portion 322. The R wall portion 322C is a portion that connects the lower peripheral wall portion 31 to the bottom wall portion 321 and has an arc-shaped annular portion in a cross section orthogonal to the circumferential direction. The R wall surface 322Ca, which is a surface on one side of the R wall portion 322C that defines the combustion chamber 10, is curved in a manner that decreases in diameter as it moves away from the filter 6 in the axial direction of the filter 6. Therefore, the lower end face 62 is supported on the housing 1 in a state where the outer peripheral edge 62a as a part thereof contacts and presses the R wall portion 322C and the non-peripheral portion 62b is separated from the R wall portion 322C. At this time, the contact state of the outer peripheral edge 62a of the lower end face 62 of the filter 6 and the R wall portion 322C is formed into an annular shape along the circumferential direction of the filter 6. Furthermore, a groove G1 is formed between the non-peripheral portion 62b and the R wall portion 322C.

[0127] The structure of supporting the filter by using such R part can also be applied to Figure 1 , Figure 7 to Figure 10 , Fig.13 For example, in Fig.10 In the gas generator shown, an R wall portion may be formed between the first cylindrical wall portion 311 and the annular wall portion 313D, and the R portion may be used to strongly contact and support the protrusion 62c of the lower end surface 62 of the filter 6D, thereby forming a groove G1 between the non-protrusion 62d and the annular wall portion 313D.

[0128] <Others>

[0129] As mentioned above, although the preferred embodiment of this disclosure is described, each aspect disclosed in this specification can also be combined with other arbitrary features disclosed in this specification.

[0130] Description of Reference Numerals

[0131] 100, 200, 300: gas generator;

[0132] 1: Shell;

[0133] 11: Gas discharge hole;

[0134] 12: peripheral wall;

[0135] 14: a partition wall portion (an example of a second wall portion);

[0136] 2: Upper shell;

[0137] 22: top plate portion (an example of the first wall portion);

[0138] 222: inclined wall portion;

[0139] 3: Lower shell;

[0140] 312: annular wall portion (an example of a connecting portion);

[0141] 32: bottom plate portion (an example of the second wall portion);

[0142] 322: inclined wall portion;

[0143] 4: Ignition device (an example of an ignition unit);

[0144] 5: Inner cylinder component;

[0145] 6: Filter;

[0146] 61: upper end surface (one end surface of the filter);

[0147] 62: lower end surface (the other end surface of the filter);

[0148] 62a: outer periphery (an example of the first part);

[0149] 62b: non-peripheral part (an example of the second part);

[0150] 62c: protrusion (an example of the first portion);

[0151] 62d: non-protruding portion (an example of the second portion);

[0152] 10: Combustion chamber;

[0153] 120: Gas generating agent.

Claims

1. A gas generator comprising: A combustion chamber, provided with an ignition portion and a gas generating agent that burns by operation of the ignition portion; a casing that defines the combustion chamber, the casing including a cylindrical peripheral wall portion, a first wall portion provided at one end side of the peripheral wall portion, and a second wall portion provided at the other end side of the peripheral wall portion, wherein a gas discharge hole that allows the combustion chamber to communicate with the outside of the casing is formed in the peripheral wall portion; and The filter is formed into a cylindrical shape, and is arranged between the gas generating agent and the gas discharge hole in the combustion chamber in a manner to surround the gas generating agent, and one axial end face of the filter is supported by the housing on the first wall side, and the other end face is supported by the housing on the second wall side. In the gas generator, with respect to a support end face which is at least one of both end faces in the axial direction of the filter, the support end face is supported by the housing in a state in which a first portion which is a part of the support end face is in contact with the housing and presses the housing, and in a state in which a second portion which is a portion of the support end face other than the first portion is separated from the housing, 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. The outer peripheral edge of the support end surface is supported by the housing as the first portion, and the outer peripheral edge of the support end surface is fitted into the housing due to the axial load applied to the filter.

2. The gas generator according to claim 1, wherein: The contact state between the first portion of the support end surface and the housing is formed by deforming the housing so as to receive the first portion or by deforming the first portion so as to increase the contact area with the housing.

3. The gas generator according to claim 2, wherein: The outer peripheral edge of the support end surface has a protrusion, which is an annular portion protruding in the axial direction of the filter more than other portions of the support end surface, and the support end surface is embedded in and supported by the housing using the protrusion as the first portion.

4. The gas generator according to claim 2 or 3, wherein: In the housing, a support portion that supports the support end surface is inclined so as to decrease in diameter as it moves away from the filter in the axial direction of the filter.

5. The gas generator according to claim 2 or 3, wherein: The ignition unit is fixed to the second wall portion. At least the other end face of the two end faces of the filter is the supporting end face, The peripheral wall portion includes: a cylindrical large diameter portion, located on the first wall portion side and formed with the gas discharge hole; a cylindrical small diameter portion, located on the second wall portion side and formed to have a smaller diameter than the large diameter portion; and an annular connecting portion, connecting the large diameter portion and the small diameter portion. In the housing, a support portion that supports the other end surface of the filter is included in the connecting portion.

6. The gas generator according to claim 5, wherein: The other end surface of the filter is supported by the housing so that a groove opening toward the radial inner side of the filter is formed between the second portion and the connecting portion.

7. The gas generator according to claim 6, wherein: The inner peripheral surface of the filter is located radially inward of the small diameter portion relative to the inner peripheral surface of the small diameter portion.

8. The gas generator according to claim 2 or 3, wherein: In the combustion chamber, a cylindrical inner cylinder member is arranged in a manner surrounding the ignition portion, whereby an ignition chamber containing a pyrotechnic agent is formed between the ignition portion and the inner cylinder member, wherein the pyrotechnic agent is burned by the operation of the ignition portion to cause the gas generating agent to burn. The inner cylinder member is formed with a communication hole for communicating the inside and outside of the ignition chamber at least when the ignition unit is in operation. In the axial direction of the filter, the communication hole is located between the second wall portion and the other end surface of the filter.

9. The gas generator according to claim 2 or 3, wherein: Both end faces of the filter in the axial direction serve as the supporting end faces.

10. A method for assembling a gas generator, the gas generator comprising: A combustion chamber, provided with an ignition portion and a gas generating agent that burns by operation of the ignition portion; a housing defining the combustion chamber, the housing including a cylindrical peripheral wall portion, a first wall portion provided at one end side of the peripheral wall portion, and a second wall portion provided at the other end side of the peripheral wall portion, wherein a gas discharge hole is formed in the peripheral wall portion to connect the combustion chamber with the outside of the housing; as well as The filter is formed into a cylindrical shape, and is arranged between the gas generating agent and the gas discharge hole in the combustion chamber in a manner to surround the gas generating agent, and one axial end face of the filter is supported by the housing on the first wall side, and the other end face is supported by the housing on the second wall side. The assembling method of the gas generator comprises: preparing a housing component constituting a part of the housing in the gas generator and supporting at least one of the two axial end faces of the filter, and the filter; as well as The filter is mounted on the housing part in such a manner that a first portion as a part of the support end surface contacts the housing and presses the housing, and a second portion as a portion other than the first portion is separated from the housing, and in such a manner that the contact state of the first portion of the support end surface with the housing is formed into an annular shape along the circumferential direction of the filter, In the process of installing the filter on the housing part, the filter is installed on the housing part in such a manner that the outer peripheral edge of the supporting end face is embedded and supported in the housing due to the axial load applied to the filter with the supporting end face as the first part, and the contact state between the outer peripheral edge of the supporting end face and the housing is formed into a ring shape along the circumference of the filter.

11. The method for assembling a gas generator according to claim 10, wherein: During installation of the filter on the housing part, the housing is deformed to receive the first portion or the first portion is deformed to increase the contact area with the housing, thereby forming a contact state between the first portion of the support end surface and the housing.

12. The method for assembling a gas generator according to claim 11, wherein: The outer peripheral edge of the support end surface has a protrusion, and the protrusion protrudes in the axial direction of the filter more than other parts of the support end surface. During installation of the filter on the housing part, the filter is installed on the housing part in such a manner that the support end surface is embedded in and supported by the housing with the protrusion as the first portion, and the contact state between the protrusion and the housing is formed into an annular shape along the circumference of the filter.

13. The method for assembling a gas generator according to claim 11 or 12, wherein: In the case component, the support portion that supports the support end surface is inclined so as to decrease in diameter as it moves away from the filter in the axial direction of the filter in the gas generator.

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