JP2021104707A - Gas generator - Google Patents

Abstract

To provide a technology that is able to hinder a short path in a gas generator.SOLUTION: In a gas generator, a housing wall portion, which is at least one of a first wall portion and a second wall portion, has an annular step part projecting toward an inner side of a combustion chamber in an axial direction of a filter and connected to a peripheral wall part. An end face, in the axial direction, of the filter is supported by its being abutted by a top face of the step part. In the combustion chamber, a cover member covering, from radial inside of the filter, a place where the end face of the filter and the top face of the step part abut on each other is provided so as to straddle the filter and the step part. The cover member includes a cylindrical first abutment surface abutting on an inner peripheral surface of the filter and a cylindrical second abutment surface abutting on an inner peripheral surface of the step part.SELECTED DRAWING: Figure 1

Description

The present invention relates to a gas generator.

Conventionally, a gas generator in which an igniter and a gas generator are arranged in a housing, the gas generator is burned by operating the igniter, and the combustion gas is discharged to the outside through a gas discharge hole formed in the housing. Is widely used.

In connection with this, a gas generator in which a tubular filter is arranged between a combustion chamber and a gas discharge hole is known in order to cool the combustion gas and collect the residue (for example, Patent Document). 1). In such a gas generator, the housing includes a tubular peripheral wall portion, a top plate portion that closes one end of the peripheral wall portion, and a bottom plate portion that closes the other end and fixes the igniter. Widely used, one end surface of a filter is in contact with a top plate and is supported, and the other end surface is in contact with a bottom plate and is supported.

By the way, in a gas generator, the internal pressure of the housing increases due to the generation of combustion gas, and the housing may be deformed so as to expand. At this time, when the top plate portion and the bottom plate portion are connected only by the tubular peripheral wall portion as in the gas generator described above, the top plate portion and the bottom plate portion are more connected than the peripheral wall portion due to the structure. It tends to be larger and more easily deformed.

On the other hand, in the gas generator disclosed in Patent Document 1, a part of the igniter collar for attaching the igniter to the bottom plate portion of the housing is formed thinly, and the igniter collar is formed in response to the deformation of the bottom plate portion. By deforming it, it is configured to absorb the distortion caused by the deformation of the bottom plate. This suppresses the formation of a gap between the igniter collar and the housing and the formation of cracks in the housing, thereby suppressing the leakage of combustion gas from the gap and the cracks to the outside of the housing.

Japanese Unexamined Patent Publication No. 2008-114718 Japanese Unexamined Patent Publication No. 2009-137478 International Publication No. 2008/083464

However, in the gas generator as described above, it is not possible to sufficiently prevent the top plate portion and the bottom plate portion from being separated from the end face of the filter due to the deformation of the housing due to the pressure of the combustion gas. If the top plate or bottom plate is separated from the end face of the filter and a gap is created between the end face of the filter and the top plate or between the end face of the filter and the bottom plate, part of the combustion gas will not pass through the filter. There is a risk that a so-called "short pass" will occur, in which the gas discharge hole is reached through the gap and the gas is discharged from the housing.

The technique of the present disclosure has been made in view of the above-mentioned problems, and an object of the present disclosure is to provide a technique capable of suppressing a short path in a gas generator.

In order to solve the above problems, the technology of the present disclosure adopts the following configuration. That is, one aspect of the technique of the present disclosure is provided in a combustion chamber in which an ignition portion and a gas generating agent burned by the operation of the ignition portion are arranged, a tubular peripheral wall portion, and one end side of the peripheral wall portion. A housing including a first wall portion, a second wall portion provided on the other end side of the peripheral wall portion and defining the combustion chamber together with the peripheral wall portion and the first wall portion, and the combustion chamber. In the combustion chamber, a housing having a gas discharge hole that communicates with the outside of the housing and a tubular filter that surrounds the gas generating agent and the gas discharge hole is located outside the housing. A gas generator comprising an arranged filter, wherein the housing wall portion, which is at least one of the first wall portion and the second wall portion, is a combustion chamber along the axial direction of the filter. It has an annular stepped portion that protrudes toward the inside of the filter and is connected to the peripheral wall portion, and the axial end surface of the filter is abutted and supported by the top surface of the stepped portion. A cover member that covers the contact portion between the end surface of the filter and the top surface of the step portion from the inside in the radial direction of the filter is provided so as to straddle the filter and the step portion. A gas generator including a tubular first contact surface that contacts the inner peripheral surface of the filter and a tubular second contact surface that contacts the inner peripheral surface of the stepped portion.

According to the gas generator of the present disclosure, since the housing wall portion has an annular step portion, the portion of the housing wall portion surrounded by the step portion (the portion radially inside the step portion) is the step portion. It is formed more easily deformed. On the other hand, by forming the step portion on the housing wall portion, rigidity is imparted to the step portion itself, the strength of the step portion of the housing wall portion is increased, and the housing wall portion is less likely to be deformed at the step portion. As a result, when the housing wall is deformed so that the housing expands due to an increase in the internal pressure of the housing, the portion surrounded by the step portion has priority over the step portion including the contact portion with the end face of the filter. Then, it is displaced to the outside of the combustion chamber in the axial direction of the filter. As a result, it is possible to prevent the contact portion of the housing wall portion from being separated from the end face of the filter due to the combustion of the gas generating agent, and it becomes easy to maintain the contact state between the end face of the filter and the housing wall portion. As a result, the short path can be suppressed.

Further, according to the gas generator of the present disclosure, since the cover member has a first contact surface that contacts the inner peripheral surface of the filter and a second contact surface that contacts the inner peripheral surface of the step portion, the internal pressure of the housing is increased. When is raised, the cover member is pressed against the inner peripheral surface of the filter and the inner peripheral surface of the stepped portion. As a result, the state in which the contact portion between the end surface of the filter and the top surface of the step portion is covered by the cover member from the inside in the radial direction of the filter is maintained. As a result, the short path can be suppressed even when the stepped portion is separated from the end face of the filter due to the combustion of the gas generating agent.

Further, in the gas generator of the present disclosure, the cover member may further include a third contact surface extending inward in the radial direction of the filter from the second contact surface and abutting the housing wall portion.

According to this, even if the step portion is separated from the end face of the filter and the combustion gas flows between the cover member and the housing wall portion, the combustion gas is formed in the gap generated between the housing wall portion and the end face of the filter. In order to reach it, the combustion gas needs to flow along the third contact surface and the second contact surface. Therefore, the path for the combustion gas to reach the gap between the housing wall and the lower end surface of the filter is a complicated crank-shaped path. This prevents the combustion gas from reaching the gap between the housing wall and the lower end surface of the filter, and as a result, the short path can be further suppressed.

Further, in the gas generator of the present disclosure, the inner peripheral surface of the step portion extends along the axial direction of the filter, and the inner peripheral surface of the filter and the inner peripheral surface of the step portion are flush with each other. The cover member may include a tubular continuous contact surface in which the first contact surface and the second contact surface are connected to each other.

According to this, by making the inner peripheral surface of the filter and the inner peripheral surface of the stepped portion flush with each other, the first contact surface that contacts the inner peripheral surface of the filter and the second contact surface that contacts the inner peripheral surface of the stepped portion. It can be flush with the contact surface. As a result, the cover member can come into contact with the inner peripheral surface of the filter and the inner peripheral surface of the stepped portion by the continuous tubular contact surface. As a result, the structure of the cover member can be simplified.

Further, in the gas generator of the present disclosure, the inner peripheral surface of the filter is located radially outside the filter with respect to the inner peripheral surface of the step portion, and the cover member is the first contact surface and the said. A fourth contact surface that connects to the second contact surface and abuts on the top surface of the step portion may be further included.

According to this, even if the step portion is separated from the end face of the filter and the combustion gas flows between the cover member and the housing wall portion, the combustion gas is formed in the gap generated between the housing wall portion and the end face of the filter. In order to reach it, the combustion gas needs to flow along the fourth contact surface and the second contact surface. Therefore, the path for the combustion gas to reach the gap between the housing wall and the lower end surface of the filter becomes a complicated crank shape. This prevents the combustion gas from reaching the gap between the housing wall and the lower end surface of the filter, and as a result, the short path can be further suppressed.

Further, in the gas generator of the present disclosure, an opening is made inward in the radial direction of the filter by a portion of the end surface of the filter and the top surface of the step portion excluding the contact portion between the end surface and the top surface. The groove is formed, and the cover member connects the first contact surface and the second contact surface, and the first contact surface and the second contact surface are inserted into the groove through the opening. An insertion surface having a diameter larger than that of the contact surface may be further included.

According to this, the cover member is positioned in the axial direction of the filter by inserting the insertion surface into the groove. As a result, the displacement of the cover member in the axial direction of the filter is suppressed, and the state where the contact point between the end surface of the filter and the top surface of the step portion is covered by the cover member from the inside in the radial direction of the filter is more reliably maintained. Will be done. As a result, the short path can be further suppressed.

The technology of the present disclosure can also be specified as follows. That is, one aspect of the technique of the present disclosure is provided in a combustion chamber in which an ignition portion and a gas generating agent burned by the operation of the ignition portion are arranged, a tubular peripheral wall portion, and one end side of the peripheral wall portion. A housing including a first wall portion, a second wall portion provided on the other end side of the peripheral wall portion and defining the combustion chamber together with the peripheral wall portion and the first wall portion, and the combustion chamber. In the combustion chamber, a housing having a gas discharge hole that communicates with the outside of the housing and a tubular filter that surrounds the gas generating agent and the gas discharge hole is located outside the housing. A gas generator including the arranged filter, the housing wall portion which is at least one of the first wall portion and the second wall portion abuts on the axial end surface of the filter. A first region that supports and is radially inside the filter from the contact portion of the filter with the end face of the housing wall portion includes a displacement portion, and the displacement portion is the gas generating agent. Formed to be more easily deformed than the portion of the housing wall portion excluding the displacement portion so that the combustion chamber is preferentially displaced to the outside of the combustion chamber over the portion of the housing wall portion excluding the displacement portion. It is a gas generator.

According to the gas generator of the present disclosure, when the housing wall portion is deformed so that the housing expands due to an increase in the internal pressure of the housing, the displacement portion has priority over the contact portion with the end face of the filter. Displaces to the outside of the combustion chamber in the axial direction of. That is, the contact portion of the housing wall portion with the end face of the filter is less likely to be displaced than the displaced portion. This will
Combustion of the gas generating agent suppresses the contact portion of the housing wall portion from separating from the end face of the filter, and the contact state between the end face of the filter and the housing wall portion can be easily maintained. As a result, the short path can be suppressed.

Further, in the gas generator of the present disclosure, the displacement portion may be formed to be thinner than the portion of the housing wall portion excluding the displacement portion at least in a part thereof.

According to this, the displacement portion can be made more easily deformed than the portion of the housing wall portion excluding the displacement portion.

Further, in the gas generator of the present disclosure, the displacement portion is more easily deformed than the portion of the housing wall portion excluding the displacement portion, and is surrounded by a first portion formed in an annular shape and the first portion. It may also include a second portion formed so as to be less deformable than the first portion.

According to this, by forming the second part surrounded by the first part to be less deformable than the first part, the influence of the displacement of the displacement part on the parts attached to the second part (the displacement of the displacement part). It is possible to reduce the dropout, breakage, etc. of the component due to the deformation of the second portion.

Further, in the gas generator of the present disclosure, the ignition unit includes a plurality of ignition devices, and the plurality of ignition devices are fixed to the second portion and correspond to each of the plurality of ignition devices. A tubular inner cylinder member surrounding the ignition device may be attached along the axial direction of the filter.

According to this, by fixing a plurality of ignition devices to the second portion, which is more difficult to deform than the first portion, the second portion is greatly deformed when the displaced portion is displaced, and the plurality of inner cylinder members interfere with each other. Can be suppressed. As a result, it is possible to prevent the inner cylinder member from coming off the ignition device or being damaged.

Further, in the gas generator of the present disclosure, the displacement portion includes an annular first portion formed so as to be more easily deformed than a portion of the housing wall portion excluding the displacement portion, and the first portion is the circumference thereof. In the cross section orthogonal to the long direction, the shape may be bent so as to be recessed toward the outside of the combustion chamber.

According to this, since the displacement portion is displaced by deforming the first portion so as to extend from the bent state, the upper limit of the displacement amount of the displacement portion can be increased. As a result, even when the internal pressure of the housing rises significantly, the expansion of the housing can be absorbed by the displacement of the displacement portion, and the displacement of the contact portion with the end face of the filter can be suppressed. As a result, the housing wall portion can be more reliably suppressed from being separated from the end face of the filter, and the short path can be more reliably suppressed. Further, by forming the first portion in a shape that is bent so as to be recessed toward the outside of the combustion chamber, it is possible to prevent the combustion chamber from becoming narrow due to the formation of the displacement portion, and to secure a sufficient volume of the combustion chamber.

Further, in the gas generator of the present disclosure, the displacement portion is formed to be thinner than the portion of the housing wall portion excluding the displacement portion as a whole, and defines the combustion chamber in the housing wall portion. Of the surfaces, the displacement surface, which is the surface in the displacement portion, includes a bottom surface located on the outer side of the combustion chamber in the axial direction of the filter rather than a peripheral surface radially outside the displacement surface, and the bottom surface. It may include a connecting curved surface that connects the surrounding surfaces with a curvature.

According to this, since the displacement surface is connected to the surrounding surface by a connecting curved surface having a curvature, stress is concentrated on the boundary portion between the displacement portion and the portion of the housing wall portion excluding the displacement portion when the housing wall portion is deformed. Can be suppressed. As a result, it is possible to prevent the housing wall portion from being cracked when the housing wall portion is deformed.

Further, in the gas generators described above, the housing wall portion has an annular step portion protruding toward the inside of the combustion chamber along the axial direction of the filter, and the end face in the axial direction of the filter. Is abutted and supported by the top surface of the stepped portion, and a portion of the housing wall portion surrounded by the stepped portion may be formed as the displacement portion.

Further, in the gas generator, in the combustion chamber, a cover member that covers the contact portion between the end surface of the filter and the top surface of the step portion from the inside in the radial direction of the filter is provided between the filter and the step. The cover member is provided so as to straddle the portion, and the cover member has a tubular first contact surface that abuts on the inner peripheral surface of the filter and a tubular second contact surface that abuts on the inner peripheral surface of the stepped portion. It may include a contact surface.

According to the technique of the present disclosure, it is possible to suppress a short path in a gas generator.

It is sectional drawing in the axial direction of the gas generator which concerns on Embodiment 1. FIG. It is a perspective view of the cover member which concerns on Embodiment 1. FIG. It is a figure which shows the state which the gas generator was burned by the operation of the ignition device, and the bottom plate part of a housing was deformed in the gas generator which concerns on Embodiment 1. FIG. It is an enlarged view of the vicinity of the bottom plate portion in FIG. It is an axial sectional view of the gas generator which concerns on the modification 1 of Embodiment 1. FIG. It is a perspective view of the cover member which concerns on modification 1 of Embodiment 1. FIG. It is a figure which shows the state which the gas generator was burned by the operation of the ignition device, and the bottom plate part of a housing was deformed in the gas generator which concerns on the modification 1 of Embodiment 1. It is an axial sectional view of the gas generator which concerns on the modification 2 of Embodiment 1. FIG. It is a perspective view of the cover member which concerns on the modification 2 of Embodiment 1. FIG. It is an axial sectional view of the gas generator which concerns on the modification 3 of Embodiment 1. FIG. It is a perspective view of the cover member which concerns on modification 3 of Embodiment 1. FIG. It is an axial sectional view of the gas generator which concerns on the modification 4 of Embodiment 1. FIG. It is sectional drawing in the axial direction of the gas generator which concerns on Embodiment 2. FIG. It is a top view of the top plate part which concerns on Embodiment 2. FIG. It is a figure which shows the cross section orthogonal to the circumferential direction of the 1st part in the top plate part which concerns on Embodiment 2. FIG. It is a figure which shows the state which the gas generator was burned by the operation of the ignition device, and the top plate part of a housing was deformed in the gas generator which concerns on Embodiment 2. It is an axial sectional view of the gas generator which concerns on the modification 1 of Embodiment 2. It is a figure which shows the cross section orthogonal to the circumferential direction of the 1st part in the bottom plate part which concerns on the modification 1 of Embodiment 2. In the gas generator according to the first modification of the second embodiment, a state in which the first gas generator and the second gas generator are burned by the operation of the first ignition device and the second ignition device and the bottom plate portion of the housing is deformed. It is a figure which shows. It is an axial sectional view of the gas generator which concerns on the modification 2 of Embodiment 2. It is an enlarged view of the vicinity of the top plate portion in FIG. It is a figure which shows the state when the gas generator is burned by the operation of the ignition device, and the top plate part of a housing is deformed in the gas generator which concerns on the modification 2 of Embodiment 2.

The gas generator according to the embodiment of the present disclosure will be described below with reference to the drawings. It should be noted that each configuration and a combination thereof in each embodiment are examples, and the configurations can be added, omitted, replaced, and other changes as appropriate without departing from the gist of the present invention. The present disclosure is not limited by embodiments, but only by the claims.

<Embodiment 1>
FIG. 1 is an axial sectional view of the gas generator 100 according to the first embodiment. FIG. 1 shows a state before the operation of the gas generator 100. The gas generator 100 is, for example, an airbag gas generator used for airbags.

[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 cover member 7, a gunpowder 110, a gas generator 120, and a housing 1 for accommodating them. And have. The gas generator 100 is configured as a so-called single type gas generator provided with only one ignition device. Further, the gas generator 100 burns the gas generator 120 by operating the igniter 41 included in the ignition device 4, and the gas discharge hole 11 formed in the housing 1 with the combustion gas which is the combustion product thereof. It is configured to emit from. Hereinafter, each configuration of the gas generator 100 will be described. In this specification, the operation of the igniter included in the ignition device (ignition unit) may be expressed as "the ignition device (ignition unit) operates" for convenience.

[housing]
Both ends of the housing 1 are closed in the axial direction by joining the upper shell 2 and the lower shell 3 made of metal, each of which is formed in a substantially cylindrical shape with a bottom, with their open ends facing each other. It is formed in a short cylindrical shape. Inside the housing 1, a combustion chamber 10 in which the ignition device 4, the inner cylinder member 5, the filter 6, the cover member 7, the explosive agent 110, and the gas generating agent 120 are arranged is formed. Here, the direction along the axial direction of the housing 1 is defined as the vertical direction of the gas generator 100, the upper shell 2 side (that is, the upper side in FIG. 1) is the upper side of the gas generator 100, and the lower shell 3 side (that is, that is). , The lower side in FIG. 1) is the lower side of the gas generator 100.

The upper shell 2 has a tubular 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 these. An opening of the upper shell 2 is formed by the lower end portion of the upper peripheral wall portion 21. A joint portion 23 extending radially outward is connected to the lower end portion of the upper peripheral wall portion 21. The lower shell 3 has a tubular lower peripheral wall portion 31 and a bottom plate portion 32 that closes the lower end of the lower peripheral wall portion 31, and forms an internal space by these. A joint portion 33 extending radially outward is connected to the upper end portion of the lower peripheral wall portion 31. A mounting hole 32a for mounting the igniter 41 of the ignition device 4 to the bottom plate portion 32 is formed in the center of the bottom plate portion 32.

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 to form a short cylindrical housing 1 in which both ends in the axial direction are closed. The upper peripheral wall portion 21 of the upper shell 2 and the lower peripheral wall portion 31 of the lower shell form a tubular peripheral wall portion 12 that connects the top plate portion 22 and the bottom plate portion 32. That is, the housing 1 includes a tubular peripheral wall portion 12, a top plate portion 22 provided on one end side of the peripheral wall portion 12, and a bottom plate portion 32 provided on the other end side. The combustion chamber 10 is defined by the top plate portion 22, the bottom plate portion 32, and the peripheral wall portion 12. The top plate portion 22 corresponds to the “first wall portion” according to the present disclosure. Further, the bottom plate portion 32 corresponds to the “second wall portion” according to the present disclosure. Further, in the upper peripheral wall portion 21 of the upper shell 2, a plurality of gas discharge holes 11 that communicate the combustion chamber 10 and the external space of the housing 1 are formed side by side along the circumferential direction. The gas discharge hole 11 is closed by a sealing tape (not shown) before the ignition device 4 is activated.

Here, the bottom plate portion 32 of the lower shell includes a bottom wall portion 321, a mounting portion 322, and a step portion 323. 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 orthogonal to the axial direction of the filter 6. The mounting portion 322 is a portion to which the igniter 41 is mounted, and is formed in a substantially tubular shape by being raised toward the inside of the combustion chamber 10 including the mounting hole 32a. The step portion 323 is an annular portion that abuts and supports the filter 6 as will be described later, and projects toward the inside of the combustion chamber 10 along the axial direction of the filter 6 and the peripheral wall portion 12 (lower peripheral wall portion 31). ) Is connected. The step portion 323 is an annular portion formed between the bottom wall portion 321 and the peripheral wall portion 12, and the shape of the cross section orthogonal to the peripheral length direction thereof is a crank-shaped portion. The top surface 323a, which is the axial end surface of the step portion 323, extends in the radial direction of the filter 6 so as to be orthogonal to the axial direction of the filter 6. Further, the inner peripheral surface 323b of the step portion 323 extends along the axial direction of the filter 6.

[Ignition system]
The ignition device 4 is fixed to a mounting portion 322 formed on a bottom plate portion 32 of the lower shell 3. As shown in FIG. 1, the ignition device 4 includes an igniter 41 and a holding portion 42 made of a resin material for fixing the igniter 41 to a mounting portion 322. The ignition device 4 corresponds to the "ignition unit" according to the present disclosure. The igniter 41 has a metal cup body 411 containing an igniter and a pair of energizing pins 421 and 412 for receiving an electric current supply from the outside. The igniter 41 is operated by the ignition current supplied to the pair of energizing pins 421 and 412 to burn the igniter and release the combustion product to the outside of the cup body 411. The holding portion 42 is a resin member that fixes the igniter 41 to the mounting portion 322 by being interposed between the igniter 41 and the mounting portion 322. The holding portion 42 ignites the mounting portion 322 so that at least a part of the cup body 411 is exposed from the holding portion 42 by covering the lower portion of the igniter 41 and engaging with the mounting portion 322. Fix the vessel 41. However, the entire cup body 411 may be overmolded by the holding portion 42. That is, the entire cup body 411 may be covered with resin. Further, the holding portion 42 forms a connector insertion space inside the mounting portion 322 into which a connector (not shown) for supplying electric power from an external power source can be inserted into the pair of energizing pins 421 and 412. The holding portion 42 covers and holds a part of the pair of energizing pins 421 and 412 so that the lower ends of the pair of energizing pins 421 and 412 are exposed in the connector insertion space. The holding portion 42 maintains the insulating property between the pair of energizing pins 421 and 412.

[Inner cylinder member]
The inner cylinder member 5 is a tubular 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 tubular shape in which one end (upper end) is closed and the other end is open, and the mounting portion 322 is fitted (press-fitted) into the other end (lower end) to form a bottom plate portion 32. It is installed. A fire transmission room 51, which is a space for accommodating the ignition charge 110, is formed between the inner cylinder member 5 and the ignition device 4. The ignition charge 110 is burned by the operation of the igniter 41 to generate combustion gas. Further, the inner cylinder member 5 is formed with a plurality of communication holes 52 for communicating the internal space (that is, the fire transmission room 51) and the external space. The communication hole 52 is closed by a sealing tape (not shown) before the ignition device 4 is activated.

[filter]
As shown in FIG. 1, the filter 6 is formed in a tubular shape, surrounds the gas generating agent 120, and is arranged in the combustion chamber 10 so that the gas discharge hole 11 is located outside the gas generating agent 120 in the radial direction thereof. Has been done. That is, the filter 6 is arranged between the gas generator 120 and the gas discharge hole 11 so as to surround the gas generator 120. Of both end faces in the axial direction, one end surface (upper end surface indicated by reference numeral 61) of the filter 6 is in contact with and supported by the top plate portion 22 of the upper shell 2, and the other end surface (lower end surface indicated by reference numeral 62) is lower. It is supported by being in contact with the stepped portion 323 in the bottom plate portion 32 of the shell. 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). The filter 6 cools the combustion gas by taking heat of the combustion gas when the combustion gas of the gas generating agent 120 arranged in the combustion chamber 10 passes through the filter 6. Further, the filter 6 has a function of filtering the combustion gas by collecting the combustion residue contained in the combustion gas, in addition to the function of cooling the combustion gas. In FIG. 1, reference numeral 63 indicates an inner peripheral surface of the filter 6, and reference numeral 64 indicates an outer peripheral surface of the filter 6. As shown in FIG. 1, in the gas generator 100, the inner peripheral surface 63 of the filter 6 and the inner peripheral surface 323b of the step portion 323 are flush with each other. In this example, the upper end surface 61 of the filter and the top plate portion 22 are in direct contact with each other, and the lower end surface 62 and the top surface 323a of the step portion 323 are in direct contact with each other. Members may intervene.

[Gunpowder]
As the propellant 110, in addition to the known black powder, a gas generator having good ignitability and a combustion temperature higher than that of the gas generator 120 can be used. The combustion temperature of the gunpowder 110 can be set in the range of 1700 to 3000 ° C. As such a gunpowder 110, known ones containing, for example, nitroguanidine (34% by weight) and strontium nitrate (56% by weight) can be used. Further, the explosive agent 110 may have various shapes such as granules, pellets, columns, and disks.

[Gas generator]
As the gas generator 120, a gas generator having 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 to 1700 ° C. As such a gas generating agent 120, known ones containing, for example, guanidine nitrate (41% by weight), basic copper nitrate (49% by weight), a binder and additives can be used. Further, the gas generating agent 120 may have various shapes such as a granular shape, a pellet shape, a columnar shape, and a disc shape.

[Displacement part]
As described above, the bottom plate portion 32 of the housing 1 is formed with an annular step portion 323 that projects toward the inside of the combustion chamber 10 along the axial direction of the filter 6 and is connected to the peripheral wall portion 12. As a result, the portion of the bottom plate portion 32 surrounded by the step portion 323, that is, the portion radially inside the step portion 323 and including the bottom wall portion 321 and the mounting portion 322, is the step portion. It is formed as a displacement portion D1 that is more easily deformed than 323. In other words, the displacement portion D1 is formed so as to be more easily deformed than the portion of the bottom plate portion 32 other than the displacement portion D1. On the other hand, by forming the step portion 323 on the bottom plate portion 32, the step portion 323 itself is imparted with rigidity, the strength of the step portion 323 of the bottom plate portion 32 is increased, and the bottom plate portion 32 is deformed at the step portion 323. It is difficult to form.

Here, the portion of the bottom plate portion 32 that comes into contact with the lower end surface (the other end surface) 62 of the filter 6 is referred to as the contact portion C1. In this example, the contact portion C1 is a part of the step portion 323. At this time, the bottom plate portion 32 can be divided into a first region A1 which is a region radially inside the contact portion C1 and a second region A2 which is a region excluding the first region A1. The second region A2 is an annular region defined on the outer side in the radial direction of the first region A1, and is connected to the peripheral wall portion 12 (lower peripheral wall portion 31) at the outer peripheral edge thereof. The second region A2 includes the contact portion C1. The first region A1 is defined as a region inside the second region A2 in the radial direction (that is, a region surrounded by the second region A2). As described above, since the displacement portion D1 is formed as a portion surrounded by the step portion 323 including the contact portion C1, the first region A1 includes the displacement portion D1. That is, the displacement portion D1 is deformed more than the portion of the bottom plate portion 32 excluding the displacement portion D1 (that is, the step portion 323) in the first region A1 radially inside the filter 6 with respect to the contact portion C1 in the bottom plate portion 32. It is easily formed.

[Cover member]
FIG. 2 is a perspective view of the cover member 7. The cover member 7 is provided in the combustion chamber 10 so as to straddle the filter 6 and the step portion 323, so that the contact point between the lower end surface 62 of the filter 6 and the top surface 323a of the step portion 323 is the diameter of the filter 6. It is a member that covers from the inside in the direction.

As shown in FIG. 1, the cover member 7 has a tubular portion 71 extending along the inner peripheral surface of the filter 6 and a bottom wall portion inward in the radial direction from one end edge (lower end edge) of the tubular portion 71. Includes an annular portion 72 extending along 321. The outer peripheral surface of the tubular portion 71 is in contact with the inner peripheral surface 63 of the filter 6 and the inner peripheral surface 323b of the stepped portion 323. Here, among the outer peripheral surfaces of the tubular portion 71, the tubular surface that abuts on the inner peripheral surface 63 of the filter 6 is referred to as the first contact surface S1, and the tubular surface that abuts on the inner peripheral surface 323b of the stepped portion 323. The surface of is referred to as a second contact surface S2. That is, the outer peripheral surface of the tubular portion 71 can be regarded as a tubular surface in which the first contact surface S1 and the second contact surface S2 that are flush with each other are connected. The outer peripheral surface of the tubular portion 71 corresponds to the "continuous contact surface" according to the present disclosure. Further, the axial end surface (that is, the lower surface) of the annular portion 72 extends radially inward from the second contact surface S2 and abuts on the bottom wall portion 321. The axial end surface of the annular portion 72 is referred to as a third contact surface S3.

The cover member 7 includes at least a first contact surface S1 that contacts the inner peripheral surface 63 of the filter 6 and a second contact surface S2 that contacts the inner peripheral surface 323b of the stepped portion 323, as shown in FIG. As described above, the contact portion is straddled between the filter 6 and the step portion 323 so as to cover the contact portion from the inside in the radial direction of the filter 6.

[motion]
Hereinafter, the operation of the gas generator 100 according to the first embodiment will be described. First, it will be described with reference to FIG. When the sensor (not shown) detects an impact, an ignition current is supplied to the pair of energizing pins 421 and 412 to operate the igniter 41. Then, the igniting agent contained in the cup body 411 of the igniter 41 burns, and the flame, high-temperature gas, or the like which is the combustion product thereof is released to the outside of the cup body 411. As a result, the fire-transmitting agent 110 housed in the fire-transmitting room 51 burns, and combustion gas is generated. The combustion gas of the transmission hole 110 breaks the sealing tape that has blocked the communication hole 52 and is discharged from the communication hole 52 to the outside of the fire transmission room 51. Then, the combustion gas of the igniter 110 comes into contact with the gas generator 120, and the gas generator 120 is ignited. When the gas generating agent 120 burns, high-temperature and high-pressure combustion gas is generated in the combustion chamber 10. When this combustion gas passes through the filter 6, the combustion gas is cooled and the 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 and 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. .. The combustion gas of the gas generating agent 120 flows into an airbag (not shown) after being discharged to the outside of the housing 1. The expansion of the airbag creates a cushion between the occupant and the rigid structure, protecting the occupant from impact.

By the way, in a gas generator, when the internal pressure of the housing forming the combustion chamber rises due to the combustion of the gas generator and the generation of combustion gas in the combustion chamber, the housing may be deformed so as to expand. That is, the housing may be deformed to increase its volume. Here, the housing 1 according to the present embodiment has a structure in which the top plate portion 22 and the bottom plate portion 32 are connected only by the tubular peripheral wall portion 12, and the top plate portion 22 and the bottom plate portion 32 other than the peripheral wall portion 12 are connected.
Since it does not have a member for connecting or fixing the top plate portion 22 and the bottom plate portion 32, the top plate portion 22 and the bottom plate portion 32 tend to be larger and more easily deformed than the peripheral wall portion 12.

As the internal pressure of the housing rises, pressure acts on the top plate and the bottom plate in a direction in which the top plate and the bottom plate are separated from the end face of the filter. If the top plate and bottom plate are separated from the end face of the filter due to the expansion of the housing due to the increase in internal pressure and a gap is formed between the end face of the filter and the top plate or bottom plate, a part of the combustion gas is released. There is a concern that it will reach the gas discharge hole through the gap without passing through the filter. That is, there is a risk that a so-called "short pass" will occur.

Here, FIG. 3 is a diagram showing a state in which the gas generating agent 120 is burned by the operation of the ignition device 4 and the bottom plate portion 32 of the housing 1 is deformed. Further, FIG. 4 is an enlarged view of the vicinity of the bottom plate portion 32 in FIG. The gas generator 100 according to the first embodiment is configured so that a short path can be suppressed even if the bottom plate portion 32 is deformed so that the housing 1 swells. Hereinafter, a detailed description will be given.

When the ignition device 4 operates and the gas generating agent 120 burns, the internal pressure of the housing 1 rises due to the generation of combustion gas. The internal pressure of the housing 1 acts on the housing 1 toward the outside of the combustion chamber 10. Therefore, an internal pressure acts on the bottom plate portion 32 in the axial direction of the filter 6 in the direction in which the bottom plate portion 32 tends to be separated from the filter 6 (that is, downward). As described above, in the bottom plate portion 32, the displacement portion D1 which is more easily deformed than the other portions in the bottom plate portion 32 is the first region A1 on the radial inside of the filter 6 with respect to the step portion 323 including the contact portion C1. Is formed in. Therefore, when the bottom plate portion 32 is deformed so that the housing 1 expands due to an increase in the internal pressure of the housing 1, the cross-sectional shape formed between the step portion 323 (the bottom wall portion 321 and the peripheral wall portion 12) is a crank. The displacement portion D1 is preferentially displaced downward rather than the shaped portion). That is, the displacement portion D1 is displaced downward with a lower pressure than the step portion 323.

The displacement portion D1 is displaced downward in preference to the step portion 323 to increase the volume of the housing 1, and thus the influence of the increase in the internal pressure of the housing 1 (the action of attempting to displace the step portion 323 downward). ) Becomes difficult to reach the step portion 323. That is, by absorbing the expansion of the housing 1 by the displacement of the displacement portion D1, the displacement of the step portion 323 can be suppressed. As a result, as shown in FIG. 4, the step portion 323 including the contact portion C1 is suppressed from being separated from the lower end surface 62 of the filter 6. As a result, in the gas generator 100 according to the first embodiment, a short path due to the bottom plate portion 32 being separated from the lower end surface 62 of the filter 6 is suppressed.

Further, when the internal pressure of the housing 1 rises due to the generation of the combustion gas, the internal pressure of the housing 1 also acts on the cover member 7 toward the outside of the combustion chamber 10. As described above, since the cover member 7 is in contact with the inner peripheral surface 63 of the filter 6 on the first contact surface S1, it is pressed against the inner peripheral surface 63 of the filter 6 due to the increase in the internal pressure of the housing 1. Further, since the cover member 7 is in contact with the inner peripheral surface 323b of the step portion 323 on the second contact surface S2, the cover member 7 is pressed against the inner peripheral surface 323b of the step portion 323 due to an increase in the internal pressure of the housing 1. As a result, as shown in FIGS. 3 and 4, the contact portion between the lower end surface 62 of the filter 6 and the top surface 323a of the step portion 323 is maintained in a state of being covered from the radial inside of the filter 6 by the cover member 7. Will be done. As a result, in the gas generator 100 according to the first embodiment, if the step portion 323 is separated from the lower end surface 62 of the filter 6 and a gap is formed between the bottom plate portion 32 and the lower end surface 62 of the filter 6. However, the cover member 7 covers the gap from the inside of the filter 6 in the radial direction, and the short path is suppressed.

[Action / Effect]
As described above, in the gas generator 100 according to the first embodiment, the bottom plate portion 32 of the housing 1 projects toward the inside of the combustion chamber 10 along the axial direction of the filter 6 and is connected to the peripheral wall portion 12. By having the step portion 323, the step portion 323 itself is imparted with rigidity, and the portion of the bottom plate portion 32 surrounded by the step portion 323 is formed as a displacement portion D1 that is more easily deformed than the step portion 323. Has been done. Then, the lower end surface 62 of the filter 6 is in contact with and supported by the top surface 323a of the step portion 323. As a result, when the bottom plate portion 32 is deformed so that the housing 1 expands due to an increase in the internal pressure of the housing 1, the displacement portion D1 of the displacement portion D1 is more than the step portion 323 including the contact portion C1 with the lower end surface 62 of the filter 6. This is preferentially displaced to the outside of the combustion chamber 10 in the axial direction of the filter 6. As a result, according to the gas generator 100 according to the first embodiment, the combustion of the gas generator 120 prevents the contact portion C1 of the bottom plate portion 32 from separating from the lower end surface 62 of the filter 6, and the lower end surface of the filter 6 is suppressed. The contact state between the 62 and the bottom plate portion 32 is easily maintained. As a result, the short path can be suppressed.

Further, in the gas generator 100 according to the first embodiment, the cover member 7 that covers the contact portion between the lower end surface 62 of the filter 6 and the top surface 323a of the step portion 323 from the radial inside of the filter 6 is stepped with the filter 6. It is provided so as to straddle the portion 323. The cover member 7 has a tubular first contact surface S1 that contacts the inner peripheral surface 63 of the filter 6, and a tubular second contact surface S2 that contacts the inner peripheral surface 323b of the stepped portion 323. Has. According to this, when the internal pressure of the housing 1 rises, the cover member 7 is pressed against the inner peripheral surface 63 of the filter 6 and the inner peripheral surface 323b of the stepped portion 323, and the lower end surface 62 of the filter 6 and the stepped portion 323 The state in which the contact portion with the top surface 323a is covered from the radial inside of the filter 6 by the cover member 7 is maintained. As a result, according to the gas generator 100 according to the first embodiment, even when the step portion 323 is separated from the lower end surface 62 of the filter 6 due to the combustion of the gas generator 120, the short path can be suppressed. ..

Further, in the gas generator 100 according to the first embodiment, the cover member 7 extends from the second contact surface S2 inward in the radial direction of the filter 6 and comes into contact with the bottom wall portion 321 of the bottom plate portion 32. It further contains S3. According to this, even if the step portion 323 is separated from the lower end surface 62 of the filter 6 and the combustion gas flows between the cover member 7 and the bottom plate portion 32, the combustion gas still flows between the bottom plate portion 32 and the lower end surface 62 of the filter 6. In order to reach the gap formed between the two, the combustion gas needs to flow along the third contact surface S3 and the second contact surface S2. Therefore, the path for the combustion gas to reach the gap between the bottom plate portion 32 and the lower end surface 62 of the filter 6 is a complicated crank-shaped path. As a result, the combustion gas is prevented from reaching the gap between the bottom plate portion 32 and the lower end surface 62 of the filter 6, and as a result, the short path can be further suppressed.

Further, in the gas generator 100 according to the first embodiment, the inner peripheral surface 323b of the step portion 323 extends along the axial direction of the filter 6, and the inner peripheral surface 323b of the filter 6 and the inner peripheral surface 323b of the step portion 323 are extended. Is flush with each other. The outer peripheral surface of the cover member 7 is formed as a tubular continuous contact surface in which the first contact surface S1 and the second contact surface S2 are connected. By making the inner peripheral surface 63 of the filter 6 and the inner peripheral surface 323b of the step portion 323 flush with each other, the first contact surface S1 and the inner peripheral surface 323b of the step portion 323 abut on the inner peripheral surface 63 of the filter 6 are flush with each other. The second contact surface S2 that comes into contact with the surface can be flush with the second contact surface S2. As a result, the cover member 7 can come into contact with the inner peripheral surface 63 of the filter 6 and the inner peripheral surface 323b of the stepped portion 323 by the cylindrical continuous contact surface. As a result, the structure of the cover member 7 can be simplified.

In this example, the case where the "second wall portion" is defined as the "housing wall portion" and the step portion 323 is formed on the bottom plate portion 32 as the second wall portion has been described, but the "first wall portion" is referred to as "the first wall portion". It may be a "housing wall portion". That is, an annular step portion as described above may be formed on the top plate portion 22 as the first wall portion, and the upper end surface 61 of the filter 6 may be abutted and supported by the top surface of the step portion. Further, both the top plate portion 22 and the bottom plate portion 32 are designated as the “housing wall portion” according to the present disclosure, an annular step portion as described above is formed on both of them, and both end surfaces of the filter 6 are tops of the step portion. It may be abutted and supported by a surface.

[Modification of Embodiment 1]
Hereinafter, the gas generator according to the modified example of the first embodiment will be described. In the description of the modified example, the differences from the gas generator 100 described with reference to FIGS. 1 to 4 will be mainly described, and the same points as those of the gas generator 100 will be designated by the same reference numerals, so that detailed description thereof will be omitted. do.

[Modification 1 of Embodiment 1]
FIG. 5 is an axial sectional view of the gas generator 100A according to the first modification of the first embodiment. FIG. 5 shows the state of the gas generator 100A before operation. FIG. 6 is a perspective view of the cover member 7A according to the first modification of the first embodiment. FIG. 7 is a diagram showing a state in the vicinity of the bottom plate portion 32 when the gas generating agent 120 is burned by the operation of the ignition device 4 and the bottom plate portion 32 of the housing 1 is deformed. As shown in FIG. 5, in the gas generator 100A, the inner peripheral surface 63 of the filter 6 is located outside the inner peripheral surface 323b of the step portion 323 in the radial direction of the filter 6. As shown in FIGS. 5 and 6, the cover member 7A includes a first tubular portion 73, a second tubular portion 74, an annular portion 72, and a connecting portion 75. As shown in FIG. 5, the first tubular portion 73 extends along the inner peripheral surface 63 of the filter 6. The second tubular portion 74 extends along the inner peripheral surface 323b of the stepped portion 323, and in this example, has an outer diameter smaller than that of the first tubular portion 73. The annular portion 72 extends from the lower end edge of the second tubular portion 74 inward in the radial direction of the filter 6 along the bottom wall portion 321. The connecting portion 75 is formed in an annular shape so as to connect the lower end edge of the first tubular portion 73 and the upper end edge of the second tubular portion 74. The outer peripheral surface of the first tubular portion 73 is formed as a first contact surface S1 that abuts on the inner peripheral surface 63 of the filter 6. The outer peripheral surface of the second tubular portion 74 is formed as a second contact surface S2 that abuts on the inner peripheral surface 323b of the stepped portion 323. The lower surface of the annular portion 72 is formed as a third contact surface S3 that extends radially inward from the second contact surface S2 and abuts on the bottom wall portion 321. The lower surface of the connecting portion 75 is formed as a fourth contact surface S4 that connects the first contact surface S1 and the second contact surface S2 and abuts on the top surface 323a of the step portion 323.

According to such a gas generator 100A, the same effect as that of the gas generator 100 can be obtained. Specifically, as shown in FIG. 7, when the ignition device 4 is activated, the displacement portion D1 is displaced to the outside of the combustion chamber 10 in the axial direction of the filter 6 in preference to the step portion 323. It is possible to prevent the contact portion C1 of the bottom plate portion 32 from separating from the lower end surface 62 of the filter 6 and suppress a short path. Further, by providing the cover member 7A so as to straddle the filter 6 and the step portion 323, the contact portion between the lower end surface 62 of the filter 6 and the top surface 323a of the step portion 323 is formed by the cover member 7A to have the diameter of the filter 6. The short path can be suppressed even when the stepped portion 323 is separated from the lower end surface 62 of the filter 6 while maintaining the state of being covered from the inside in the direction.

Further, even if the step portion 323 is separated from the lower end surface 62 of the filter 6 and the combustion gas flows between the cover member 7A and the bottom plate portion 32, the combustion gas is formed between the bottom plate portion 32 and the lower end surface 62 of the filter 6. In order to reach the gap generated between them, the combustion gas needs to flow along the third contact surface S3, the fourth contact surface S4, and the second contact surface S2. Therefore, the path for the combustion gas to reach the gap between the bottom plate portion 32 and the lower end surface 62 of the filter 6 becomes more complicated. As a result, the short path can be further suppressed.

[Modification 2 of Embodiment 1]
FIG. 8 is an axial sectional view of the gas generator 100B according to the second modification of the first embodiment. FIG. 8 shows the state before the operation of the gas generator 100B. FIG. 9 is a perspective view of the cover member 7B according to the second modification of the first embodiment. As shown in FIG. 8, in the gas generator 100B, the inner peripheral surface 63 of the filter 6 is located radially outside the filter 6 with respect to the inner peripheral surface 323b of the step portion 323, similarly to the gas generator 100A. .. Further, the amount of protrusion of the step portion 323 in the gas generator 100B in the axial direction (that is, the difference in height between the bottom wall portion 321 and the step portion 323 in the axial direction) is determined by the step portion in the gas generator 100 and the gas generator 100A. It is larger than the protrusion amount of 323. This makes it possible to make the axial length of the filter 6 in the gas generator 100B shorter than the axial length of the filter 6 in the gas generator 100 and the gas generator 100A. Further, as shown in FIGS. 8 and 9, the cover member 7B includes a first tubular portion 73, a second tubular portion 74, and a connecting portion 75. Also in this example, the second tubular portion 74 has an outer diameter smaller than that of the first tubular portion 73. The cover member 7B is different from the cover member 7A according to the first modification of the first embodiment in that the cover member 7B does not have the annular portion 72. In the cover member 7B, similarly to the cover member 7A, the outer peripheral surface of the first tubular portion 73 is formed as the first contact surface S1, and the outer peripheral surface of the second tubular portion 74 is formed as the second contact surface S2. The lower surface of the connecting portion 75 is formed as the fourth contact surface S4.

The gas generator 100B according to the second modification of the first embodiment can also obtain the same effect as the gas generator 100 described above.

[Modification 3 of Embodiment 1]
FIG. 10 is an axial sectional view of the gas generator 100C according to the third modification of the first embodiment. FIG. 10 shows the state before the operation of the gas generator 100C. FIG. 11 is a perspective view of the cover member 7C according to the third modification of the first embodiment. As shown in FIG. 8, in the gas generator 100C, similarly to the gas generator 100B, the protrusion amount (axial height) of the filter 6 of the step portion 323 is the step in the gas generator 100 and the gas generator 100A. It is larger than the protruding amount of the portion 323. This makes it possible to make the axial length of the filter 6 in the gas generator 100C shorter than the axial length of the filter 6 in the gas generator 100 and the gas generator 100A. Further, as shown in FIG. 10, in the gas generator 100C, the top surface 323a of the step portion 323 is reduced in diameter toward the bottom plate portion 32 side (that is, downward) in the axial direction of the filter 6. It is tilted. As a result, among the lower end surface 62 of the filter 6 and the top surface 323a of the stepped portion 323, the groove G1 opened inward in the radial direction of the filter 6 is formed by the portion excluding the contact portion between the lower end surface 62 and the top surface 323a. It is formed. Further, as shown in FIGS. 10 and 11, the cover member 7C includes a first tubular portion 73, a second tubular portion 74, and a diameter-expanded portion 76. As shown in FIG. 10, the first tubular portion 73 extends along the inner peripheral surface 63 of the filter 6. The second tubular portion 74 extends along the inner peripheral surface 323b of the stepped portion 323. The enlarged diameter portion 76 has an outer diameter larger than that of the first tubular portion 73 and the second tubular portion 74, and includes the lower end edge of the first tubular portion 73 and the upper end edge of the second tubular portion 74. Is connected and protrudes outward in the radial direction of the filter 6. In the gas generator 100C, the outer peripheral surface of the first tubular portion 73 is formed as the first contact surface S1, and the outer peripheral surface of the second tubular portion 74 is formed as the second contact surface S2. Then, the outer peripheral surface of the enlarged diameter portion 76 connects the first contact surface S1 and the second contact surface S2, and the first contact surface S1 and the second contact surface S1 and the second contact surface S1 and the second contact surface S1 and the second contact surface S1 are inserted into the groove G1 through the opening of the groove G1. It is formed as an insertion surface S5 having a diameter larger than that of the contact surface S2.

According to the gas generator 100C according to the third modification of the first embodiment, the insertion surface S5 is inserted into the groove G1 to position the cover member 7C in the axial direction of the filter 6. As a result, the displacement of the cover member 7C in the axial direction of the filter 6 is suppressed. As a result, the contact portion between the lower end surface 62 of the filter 6 and the top surface 323a of the step portion 323 is more reliably maintained in a state of being covered from the radial inside of the filter 6 by the cover member 7C, and the short path is further further improved. It can be suppressed.

[Modification 4 of Embodiment 1]
FIG. 12 is an axial sectional view of the gas generator 100D according to the fourth modification of the first embodiment. FIG. 12 shows the state before the operation of the gas generator 100D. As shown in FIG. 12, the gas generator 100D includes a first ignition device 4X, a second ignition device 4Y, an inner cylinder member 5D, a filter 6, a cover member 7D, a gunpowder 110, and a first gas. It includes a generator 120X, a second gas generator 120Y, and a housing 1D for accommodating them. The gas generator 100D is configured as a so-called dual type gas generator provided with two ignition devices. The first ignition device 4X corresponds to the "ignition unit" according to the present disclosure. Further, the gas generator 100D burns the first gas generator 120X by the operation of the first ignition device 4X, and burns the second gas generator 120Y by the operation of the second ignition device 4Y, so that a relatively large amount is produced. The combustion gas is configured to be discharged from the gas discharge hole 11. In the gas generator 100D, the second igniter 4Y operates independently of the first igniter 4X, and when it operates, it operates at a predetermined timing after the first igniter 4X operates. do.

As shown in FIG. 12, the housing 1D according to the fourth modification of the first embodiment separates the internal space of the housing 1D into the first combustion chamber 10X and the second combustion chamber 10Y, and abuts the lower end surface 62 of the filter 6. It has a partition wall portion 14 that supports the partition wall portion 14. The partition wall portion 14 is provided between the top plate portion 22 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 22 provided on one end side of the peripheral wall portion 12. The partition wall portion 14 corresponds to the “second wall portion” according to the present disclosure. The first combustion chamber 10X is defined by the top plate portion 22, the partition wall portion 14, and the peripheral wall portion 12. Further, the second combustion chamber 10Y is defined by the partition wall portion 14, the bottom plate portion 32, and the peripheral wall portion 12. The first combustion chamber 10X contains a first gas generating agent 120X that burns by the operation of the first ignition device 4X, and the second combustion chamber 10Y generates a second gas that burns by the operation of the second ignition device 4Y. Agent 120Y is contained. 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 portion 14 includes a dividing wall portion 141 and a step portion 142. The dividing wall portion 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 orthogonal to the axial direction of the filter 6. A through hole 14a, which is a hole through which the inner cylinder member 5 penetrates, is formed in the divided wall portion 141. The step portion 142 is an annular portion that abuts and supports the lower end surface 62 of the filter 6, and projects toward the inside of the first combustion chamber 10X along the axial direction of the filter 6 and is connected to the peripheral wall portion 12. .. The axial end surface of the step portion 142 extends in the radial direction of the filter 6 so as to be orthogonal to the axial direction of the filter 6. Further, the inner peripheral surface of the step portion 142 extends along the axial direction of the filter 6.

The inner cylinder member 5D according to the fourth modification of the first embodiment extends from the bottom plate portion 32 toward the top plate portion 22 so as to surround the first ignition device 4X fixed to the bottom plate portion 32, and penetrates the partition wall portion 14. It penetrates the hole 14a and has an open end. Therefore, the space inside the inner cylinder member 5D is included in the first combustion chamber 10X, and the first ignition device 4X is arranged in the first combustion chamber 10X. Further, inside the inner cylinder member 5D, a partition member P1 for partitioning the internal space vertically is arranged. As a result, of the internal space of the inner cylinder member 5, the space below the partition member P1 (on the side of the first ignition device 4X) is formed as the fire transmission room 51. The fire-transmitting agent 110 is housed in the fire-transmitting room 51 without being mixed with the first gas generating agent 120X. The partition member P1 is made of a material that is rapidly burned, melted, or extinguished by the combustion gas of the gunpowder 110 so as not to prevent the ignition of the first gas generating agent 120X by the combustion gas of the gunpowder 110. Further, the inner cylinder member 5D is formed with a plurality of communication holes 52 for communicating the internal space of the inner cylinder member 5D (by extension, the first combustion chamber 10X) and the second combustion chamber 10Y. The communication hole 52 is closed by a sealing tape (not shown) before the second ignition device 4Y is operated.

As shown in FIG. 12, the filter 6 of the gas generator 100D is supported so that the upper end surface 61 abuts on the top plate portion 22 and is supported, and the lower end surface 62 abuts on the step portion 142 on the partition wall portion 14 and is supported. Is arranged in the first combustion chamber 10X. Here, since the step portion 142 is formed on the partition wall portion 14, the portion of the partition wall portion 14 surrounded by the step portion 142, that is, the divided wall portion 141 is a displacement portion that is more easily deformed than the step portion 142. It is formed as D1. In other words, the displacement portion D1 is formed so as to be more easily deformed than the step portion 142 which is a portion of the partition wall portion 14 excluding the displacement portion D1.

Further, as shown in FIG. 12, in the first combustion chamber 10X, a cover member 7D that covers the contact portion between the lower end surface 62 of the filter 6 and the top surface of the step portion 142 from the radial inside of the filter 6 is a filter. It is provided so as to straddle 6 and the step portion 142. Then, the cover member 7D has a tubular first contact surface S1 that abuts on the inner peripheral surface 63 of the filter 6 and a tubular second contact surface S2 that abuts on the inner peripheral surface of the step portion 142. Includes.

When such a gas generator 100D operates, first, the first ignition device 4X operates, the combustion charge 110 housed in the transmission chamber 51 of the first combustion chamber 10X burns, and the combustion gas is generated. .. When the partition member P1 is burned and removed by the combustion gas of the propellant 110, the combustion gas comes into contact with the first gas generating agent 120X, and the first gas generating agent 120X is ignited. Combustion gas is generated in the first combustion chamber 10X by burning the first gas generating agent 120X. The combustion gas of the first gas generating agent 120X passes through the filter 6 and is discharged from the gas discharge hole 11 to the outside of the housing 1. Next, the second ignition device 4Y operates, the second gas generating agent 120Y housed in the second combustion chamber 10Y burns, and the combustion gas is generated. The combustion gas of the second gas generating agent 120Y breaks the sealing tape that blocked the communication hole 52, flows from the communication hole 52 into the first combustion chamber 10X, passes through the filter 6, and closes the gas discharge hole 11. The sealing tape is broken and the gas is discharged from the gas discharge hole 11 to the outside of the housing 1D.

According to the gas generator 100D according to the fourth modification of the first embodiment, when the partition wall portion 14 is deformed so that the housing 1D expands due to the increase in the internal pressure of the housing 1D due to the combustion of the first gas generator 120X, the filter The displacement portion D1 has priority over the step portion 142 including the contact portion C1 with the lower end surface 62 of the filter 6, and is displaced to the outer side (that is, downward) of the first combustion chamber 10X in the axial direction of the filter 6. As a result, according to the gas generator 100D, the step portion 142 of the split wall portion 141 (that is, the displacement portion D1) is suppressed from being separated from the lower end surface 62 of the filter 6 due to the combustion of the first gas generator 120X, resulting in a short circuit. The path can be suppressed.

Further, according to the gas generator 100D, when the internal pressure of the housing 1 rises, the cover member 7D is pressed against the inner peripheral surface 63 of the filter 6 and the inner peripheral surface of the step portion 142, and the lower end surface 62 of the filter 6 and the step are stepped. The contact portion with the top surface of the portion 142 is maintained in a state of being covered from the radial inside of the filter 6 by the cover member 7D. As a result, according to the gas generator 100D, even when the step portion 142 is separated from the lower end surface 62 of the filter 6 due to the combustion of the first gas generator 120X, the short path can be suppressed.

<Embodiment 2>
FIG. 13 is an axial sectional view of the gas generator 200 according to the second embodiment. FIG. 1 shows a state before the operation of the gas generator 200. The gas generator 200 is an airbag gas generator used for, for example, an airbag. Hereinafter, the gas generator 200 according to the second embodiment will be described focusing on the differences from the gas generator 100, and the same points as those of the gas generator 100 will be designated by the same reference numerals, and detailed description thereof will be omitted. ..

As shown in FIG. 13, in the gas generator 200, the gas generator 100 is formed in that a step portion and a displacement portion are not formed on the bottom plate portion 32 and a displacement portion indicated by reference numeral D2 is formed on the top plate portion 22. Mainly different from. In this example, the top plate portion 22 as the first wall portion is referred to as the “housing wall portion”.

The top plate portion 22 is divided into a first region A1 which is a region inside the contact portion C1 with the upper end surface 61 of the filter 6 and a second region A2 which is a region excluding the first region A1. Can be done.
The second region A2 is an annular region defined on the outer side in the radial direction of the first region A1, and is connected to the peripheral wall portion 12 (upper peripheral wall portion 21) at the outer peripheral edge thereof. The second region A2 includes the contact portion C1. The first region A1 is defined as a region inside the second region A2 in the radial direction (that is, a region surrounded by the second region A2). As shown in FIG. 13, a displacement portion D2 is formed in the first region A1.

FIG. 14 is a top view of the top plate portion 22. As shown in FIG. 14, the displacement portion D2 includes a first portion D21 formed in an annular shape and a second portion D22 surrounded by the first portion D21. The second portion D22 does not have to be formed in a continuous annular shape over the entire circumference in the peripheral length direction, and may be formed in an intermittent annular shape in the peripheral length direction.

FIG. 15 is a view showing a cross section of the top plate portion 22 orthogonal to the peripheral length direction of the first portion D21. As shown in FIG. 15, the first portion D21 has a shape in which a part of the top plate portion 22 is bent so as to be recessed toward the outside of the combustion chamber 10 in a cross section orthogonal to the peripheral length direction thereof. More specifically, the first portion D21 is formed including the first bent portion D211 and the second bent portion D212. The first bent portion D211 is provided on the outer peripheral side of the first portion D21 and extends upward as it goes inward in the radial direction of the first portion D21. The second bent portion D212 is provided on the inner peripheral side of the first bent portion D21, and extends downward from the tip of the first bent portion D211 toward the inside of the first portion D21 in the radial direction. That is, the second bent portion D212 is bent from the tip of the first bent portion D211 so as to face the first bent portion D211. Further, the second portion D22 surrounded by the first portion D21 extends in the radial direction of the filter 6 so as to be orthogonal to the axial direction of the filter 6.

Here, the thickness dimension of the first portion D21 is t1, and the thickness dimension of the portion of the top plate portion 22 excluding the first portion D21 is t2. At this time, in the gas generator 200, t1 is smaller than t2. That is, the displacement portion D2 is formed in the first portion D21, which is a part thereof, to be thinner than the portion of the top plate portion 22 excluding the displacement portion D2. Therefore, the first portion D21 is formed so as to be more easily deformed than the portion of the top plate portion 22 other than the first portion D21. As a result, the displacement portion D2 is formed in the first region A1 radially inside the filter 6 with respect to the contact portion C1 in the top plate portion 22 to be more easily deformed than the portion of the top plate portion 22 excluding the displacement portion D2. ing. Further, in the gas generator 200, since the first portion D21 is formed to be thinner than the second portion D22, the second portion D22 is formed to be less deformable than the D21.

Here, FIG. 16 is a diagram for explaining a state in which the gas generating agent 120 is burned by the operation of the ignition device 4 and the top plate portion 22 of the housing 1 is deformed. Similar to the gas generator 100 according to the first embodiment, the gas generator 200 according to the second embodiment is configured so that a short path can be suppressed even if the bottom plate portion 32 is deformed so that the housing 1 swells. Hereinafter, a detailed description will be given.

When the ignition device 4 operates and the gas generating agent 120 burns, the internal pressure of the housing 1 rises due to the generation of combustion gas. The internal pressure of the housing 1 acts on the housing 1 toward the outside of the combustion chamber 10. Therefore, an internal pressure acts on the top plate portion 22 in the axial direction of the filter 6 in the direction in which the top plate portion 22 tends to be separated from the filter 6 (that is, upward). As described above, in the top plate portion 22, the displacement portion D2, which is more easily deformed than the other portions in the top plate portion 22, is the second diameter inside the filter 6 in the radial direction with respect to the second region A2 including the contact portion C1. It is formed in one region A1. Therefore, when the top plate portion 22 is deformed so that the housing 1 expands due to an increase in the internal pressure of the housing 1, the displacement portion D2 has priority over the portion of the top plate portion 22 excluding the displacement portion D2. Displaces upward. That is, the displacement portion D2 is displaced upward with a lower pressure than the second region A2. At this time, as shown in FIG. 16, the first portion D21 is bent so that the first bent portion D211 and the second bent portion D212 face each other (bent state), and then the first bent portion D211 and the second bent portion D211 and the second bent portion D21. The portion D212 is deformed so as to be in an extended state (extended state) so as to open. As a result, the displacement portion D2 is allowed to be displaced upward.

The displacement portion D2 is displaced upward in preference to the second region A2 to increase the volume of the housing 1, so that the influence of the increase in the internal pressure of the housing 1 (to displace the second region A2 upward). The action) becomes difficult to reach the second region A2. Therefore, the second region A2 including the contact portion C1 with the upper end surface 61 of the filter 6 on the top plate portion 22 is less likely to be displaced than the displacement portion D2. As a result, as shown in FIG. 16, the second region A2 including the contact portion C1 is suppressed from being separated from the upper end surface 61 of the filter 6, and the upper end surface 61 of the filter 6 and the top plate portion 22 are in contact with each other. Is easier to maintain. As a result, in the gas generator 200 according to the second embodiment, a short path due to the top plate portion 22 being separated from the upper end surface 61 of the filter 6 is suppressed.

[Action / Effect]
As described above, in the gas generator 200 according to the second embodiment, the top plate portion 22 abuts and supports the upper end surface 61 of the filter 6 and is in contact with the upper end surface 61 of the filter 6 in the top plate portion 22. The displacement portion D2 is included in the first region A1 which is a region inside the filter 6 in the radial direction from the contact portion C1. Then, the displacement portion D2 is displaced in the top plate portion 22 so that when the gas generating agent 120 is burned, the displacement portion D2 is preferentially displaced to the outside of the combustion chamber 10 over the portion of the top plate portion 22 excluding the displacement portion D2. It is formed so as to be more easily deformed than the portion other than the portion D2.

As a result, when the top plate portion 22 is deformed so that the housing 1 expands due to an increase in the internal pressure of the housing 1, the displacement portion is larger than the second region A2 including the contact portion C1 with the upper end surface 61 of the filter 6. D2 has priority and is displaced to the outside of the combustion chamber 10 in the axial direction of the filter 6. As a result, according to the gas generator 200 according to the second embodiment, it is possible to suppress the top plate portion 22 from separating from the upper end surface 61 of the filter 6 due to the combustion of the gas generator 120, and to suppress a short path.

Further, in the gas generator 200, the displacement portion D2 is formed in at least a part thereof (in this example, the first portion D21) to be thinner than the portion of the top plate portion 22 excluding the displacement portion D2. As a result, the displacement portion D2 can be made more easily deformed than the portion of the top plate portion 22 excluding the displacement portion D2.

Further, in the gas generator 200, the displacement portion D2 includes an annular first portion D21 formed so as to be more easily deformed than a portion of the top plate portion 22 excluding the displacement portion D2, and the first portion D21 has a peripheral length thereof. It has a shape that is bent so as to be recessed toward the outside of the combustion chamber 10 in a cross section orthogonal to the direction. Therefore, the displacement portion D2 is displaced by deforming the first portion D21 so as to extend from the bent state. According to this, the upper limit of the displacement amount of the displacement portion D2 can be increased. That is, it is possible to secure a large volume of the housing that can be realized by displacing the displacement portion D2. As a result, even when the internal pressure of the housing 1 rises significantly, the expansion of the housing 1 can be absorbed by the displacement of the displacement portion D2, and the displacement of the portion of the top plate portion 22 other than the displacement portion D2 can be suppressed. Can be done. As a result, the top plate portion 22 can be more reliably suppressed from being separated from the upper end surface 61 of the filter 6, and the short path can be more reliably suppressed. Further, by forming the first portion D21 so as to be bent so as to be recessed toward the outside of the combustion chamber 10, it is possible to prevent the combustion chamber 10 from becoming narrow due to the formation of the displacement portion D2, and to increase the volume of the combustion chamber 10. It can be secured sufficiently.

[Modified Example of Embodiment 2]
Hereinafter, the gas generator according to the modified example of the second embodiment will be described. In the description of the modified example, the differences from the gas generator 100 described with reference to FIGS. 13 to 16 will be mainly described, and the gas generator 100 will be described.
The same points as above are given the same reference numerals, and detailed explanations are omitted.

[Modification 1 of Embodiment 2]
FIG. 17 is an axial sectional view of the gas generator 200A according to the first modification of the second embodiment. FIG. 17 shows the state of the gas generator 200A before operation.

As shown in FIG. 17, the gas generator 200A includes a first ignition device 4X, a second ignition device 4Y, a first inner cylinder member 5X, a second inner cylinder member 5Y, a filter 6, and a gunpowder 110. A first gas generator 120X, a second gas generator 120Y, and a housing 1 for accommodating these are provided. The gas generator 200A is configured as a so-called dual type gas generator provided with two ignition devices. The first ignition device 4X and the second ignition device 4Y correspond to the "ignition unit" according to the present disclosure. The gas generator 200A burns the first gas generator 120X by the operation of the first ignition device 4X, and burns the second gas generator 120Y by the operation of the second ignition device 4Y, so that a relatively large amount of combustion gas is produced. Is configured to be discharged from the gas discharge hole 11. In the gas generator 200A, the first combustion chamber 10X in which the first gas generating agent 120X is housed is defined by the top plate portion 22, the bottom plate portion 32, and the peripheral wall portion 12. The first combustion chamber 10X corresponds to the "combustion chamber" according to the present disclosure.

Further, in the gas generator 200A, the displacement portion D2 is formed on the bottom plate portion 32. In this example, the bottom plate portion 32 as the second wall portion is referred to as the “housing wall portion”. The bottom plate portion 32 can be divided into a first region A1 which is a region inside the contact portion C1 with the lower end surface 62 of the filter 6 and a second region A2 which is a region excluding the first region A1. A displacement portion D2 is formed in the first region A1. The displacement portion D2 includes a first portion D21 formed in an annular shape and a second portion D22 surrounded by the first portion D21.

FIG. 18 is a view showing a cross section of the bottom plate portion 32 orthogonal to the peripheral length direction of the first portion D21. The first portion D21 has a shape in which a part of the bottom plate portion 32 is bent so as to be recessed toward the outside of the combustion chamber 10 in a cross section orthogonal to the peripheral length direction thereof. Further, the second portion D22 surrounded by the first portion D21 extends in the radial direction of the filter 6 so as to be orthogonal to the axial direction of the filter 6. At this time, in the gas generator 200A, the thickness dimension t3 of the first portion D21 is smaller than the thickness dimension t4 of the portion of the bottom plate portion 32 excluding the first portion D21. That is, the displacement portion D2 is formed in the first portion D21, which is a part thereof, to be thinner than the portion of the bottom plate portion 32 excluding the displacement portion D2. Therefore, the first portion D21 is formed so as to be more easily deformed than the portion of the bottom plate portion 32 other than the first portion D21. Further, in the gas generator 200A, since the first portion D21 is formed to be thinner than the second portion D22, the second portion D22 is formed to be less deformable than the D21.

Here, as shown in FIG. 17, in the gas generator 200A, the first ignition device 4X and the second ignition device 4Y are fixed to the second portion D22 of the bottom plate portion 32. Further, in the gas generator 200A, a first inner cylinder member 5X and a second inner cylinder member 5Y are provided corresponding to each of the first ignition device 4X and the second ignition device 4Y. More specifically, the tubular first inner cylinder member 5X surrounding the first ignition device 4X and the tubular second inner cylinder member 5Y surrounding the second ignition device 4Y are formed along the axial direction of the filter 6. It is attached. A fire transmission room 51 is formed between the first inner cylinder member 5X and the first ignition device 4X to accommodate the fire transfer agent 110 that burns due to the operation of the first ignition device 4X. Similarly, a second combustion chamber 10Y in which a second gas generating agent 120Y burned by the operation of the second ignition device 4Y is housed is formed between the second inner cylinder member 5Y and the second ignition device 4Y. There is. The first inner cylinder member 5X is formed with a plurality of communication holes 52 that communicate the fire transmission room 51 and its external space. Similarly, the second inner cylinder member 5Y is formed with a plurality of communication holes 52 that communicate the second combustion chamber 10Y and its external space. Each communication hole 52 is closed with sealing tape (not shown) before the corresponding ignition device is activated.

When such a gas generator 200A operates, first, the first ignition device 4X operates, the flame-transmitting agent 110 housed in the fire-transmitting room 51 burns, and the combustion gas is generated. The combustion gas of the fire-transmitting agent 110 breaks the sealing tape that has blocked the communication hole 52 of the first inner cylinder member 5X and is discharged from the communication hole 52 to the outside of the fire transmission chamber 51, so that the first gas generating agent 120X Burns, and combustion gas is generated in the first combustion chamber 10X. The combustion gas of the first gas generating agent 120X passes through the filter 6, breaks the sealing tape that blocked the gas discharge hole 11, and is discharged from the gas discharge hole 11 to the outside of the housing 1. Next, the second ignition device 4Y operates, the second gas generating agent 120Y housed in the second combustion chamber 10Y burns, and the combustion gas is generated. The combustion gas of the second gas generating agent 120Y breaks the sealing tape that blocked the communication hole 52, is discharged from the communication hole 52 to the outside of the second combustion chamber 10Y, passes through the filter 6, and passes through the gas discharge hole 11. It is discharged to the outside of the housing 1.

FIG. 19 is a diagram showing a state when the first gas generating agent 120X and the second gas generating agent 120Y are burned by the operation of the first ignition device 4X and the second ignition device 4Y and the bottom plate portion 32 of the housing 1 is deformed. Is. As shown in FIG. 19, when the bottom plate portion 32 is deformed so that the housing 1 expands due to an increase in the internal pressure of the housing 1, the second region A2 including the contact portion C1 with the lower end surface 62 of the filter 6 The displacement portion D2 is preferentially displaced to the outer side (that is, downward) of the combustion chamber 10 in the axial direction of the filter 6. As a result, according to the gas generator 200A, the bottom plate portion 32 is prevented from being separated from the lower end surface 62 of the filter 6, and a short path can be suppressed.

Further, in the gas generator 200A, the first ignition device 4X and the second ignition device 4Y are fixed to the second portion D22 of the bottom plate portion 32, and correspond to each of the first ignition device 4X and the second ignition device 4Y. The first inner cylinder member 5X and the second inner cylinder member 5Y are attached along the axial direction of the filter 6. According to this, by fixing the first igniter 4X and the second igniter 4Y to the second igniter D22, which is less likely to be deformed than the first slab D21, the second slab D22 becomes larger when the displacement portion D2 is displaced. It is possible to prevent the first inner cylinder member 5X and the second inner cylinder member 5Y from being deformed and interfering with each other. As a result, it is possible to prevent the first inner cylinder member 5X and the second inner cylinder member 5Y from coming off or being damaged from the first ignition device 4X and the second ignition device 4Y. As described above, by forming the first portion D21 in the bottom plate portion 32 which is more easily deformed than other portions in a ring shape, it is possible to form the second portion D22 which is less deformable than the first portion D21 inside the first portion D21. can. As a result, the influence of the displacement of the displacement portion D2 on the parts attached to the second portion D22 (dropping, breakage, etc. of the parts due to the deformation of the second portion D22 due to the displacement of the displacement portion D2) is reduced. be able to.

The number of ignition devices fixed to the bottom plate portion 32 is not limited to two, and may be one or three or more.

[Modification 2 of Embodiment 2]
FIG. 20 is an axial sectional view of the gas generator 200B according to the second modification of the second embodiment. The state before the operation of the gas generator 200B is shown. FIG. 21 is an enlarged view of the vicinity of the top plate portion 22 in FIG. 20. As shown in FIG. 20, in the gas generator 200B, the displacement portion indicated by reference numeral D3 is formed on the top plate portion 22. In this example, the top plate portion 22 as the first wall portion is referred to as the “housing wall portion”. The top plate portion 22 is divided into a first region A1 which is a region inside the contact portion C1 with the upper end surface 61 of the filter 6 and a second region A2 which is a region excluding the first region A1. A displacement portion D3 is formed in the first region A1.

Here, as shown in FIG. 21, the thickness dimension of the displacement portion D3 is t5, and the thickness dimension of the portion of the top plate portion 22 excluding the displacement portion D3 is t6. At this time, in the gas generator 200B, t
T5 is smaller than 6. That is, the entire displacement portion D3 is formed to be thinner than the portion of the top plate portion 22 excluding the displacement portion D3. As a result, the displacement portion D3 is formed in the first region A1 radially inside the filter 6 with respect to the contact portion C1 in the top plate portion 22 to be more easily deformed than the portion of the top plate portion 22 excluding the displacement portion D3. ing.

Further, among the surfaces defining the combustion chamber in the top plate portion 22 (that is, the lower surface of the top plate portion 22), the surface in the displacement portion D3 is defined as the displacement surface S100, and the surface on the radial outer side of the filter 6 from the displacement surface S100. Is the peripheral surface S200. At this time, the displacement surface S100 has a curvature of the bottom surface S10 located on the outer side (that is, the upper side) of the combustion chamber 10 in the axial direction of the filter 6 with respect to the peripheral surface S200, and the bottom surface S10 and the peripheral surface S200. It includes a connection curved surface S20 to be connected.

FIG. 22 is a diagram showing a state when the gas generating agent 120 is burned by the operation of the ignition device 4 and the top plate portion 22 of the housing 1 is deformed. As shown in FIG. 22, when the top plate portion 22 is deformed so that the housing 1 expands due to an increase in the internal pressure of the housing 1, the second region A2 including the contact portion C1 with the upper end surface 61 of the filter 6 The displacement portion D3 is preferentially displaced toward the outside (that is, upward) of the combustion chamber 10 in the axial direction of the filter 6. As a result, according to the gas generator 200B, the top plate portion 22 is prevented from being separated from the upper end surface 61 of the filter 6, and a short path can be suppressed.

Further, since the displacement surface S100 is connected to the peripheral surface S200 by the connecting curved surface S20 having a curvature, the boundary portion between the displacement portion D3 and the portion of the top plate portion 22 excluding the displacement portion D3 when the top plate portion 22 is deformed. It is possible to suppress the concentration of stress on the surface. As a result, it is possible to prevent the top plate portion 22 from being cracked when the top plate portion 22 is deformed.

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

100,200 Gas generator 1 Housing 11 Gas discharge hole 12 Peripheral wall part 14 Partition wall part (example of second wall part)
142 Step 2 Upper shell 22 Top plate (an example of the first wall)
3 Lower shell 32 Bottom plate (an example of the second wall)
323 Stepped part 323a Top surface 323b Inner peripheral surface 4 Ignition system (an example of ignition part)
5 Inner cylinder member 6 Filter 61 Upper end surface (one end surface of filter)
62 Lower end surface (the other end surface of the filter)
63 Inner peripheral surface 7 Cover member 10 Combustion chamber 120 Gas generator A1 First area A2 Second area D1, D2, D3 Displacement part D21 First part D21 Second part S1 First contact surface S2 Second contact surface S3 3rd contact surface S4 4th contact surface S5 Insertion surface S100 Displacement surface S10 Bottom surface S20 Connection curved surface G1 groove

Claims (13)

A combustion chamber in which an ignition unit and a gas generating agent that burns by the operation of the ignition unit are arranged, and
A tubular peripheral wall portion, a first wall portion provided on one end side of the peripheral wall portion, and a combustion chamber provided on the other end side of the peripheral wall portion and defining the combustion chamber together with the peripheral wall portion and the first wall portion. A housing including a second wall portion and having a gas discharge hole that communicates the combustion chamber and the outside of the housing.
A tubular filter, the filter which surrounds the gas generating agent and is arranged in the combustion chamber so that the gas discharge hole is located outside the filter.
It is a gas generator equipped with
The housing wall portion, which is at least one of the first wall portion and the second wall portion, projects toward the inside of the combustion chamber along the axial direction of the filter and is an annular shape connected to the peripheral wall portion. Has a stepped part,
The axial end face of the filter is abutted and supported by the top surface of the stepped portion.
The combustion chamber is provided with a cover member that covers the contact portion between the end surface of the filter and the top surface of the step portion from the inside in the radial direction of the filter so as to straddle the filter and the step portion. ,
The cover member includes a tubular first contact surface that contacts the inner peripheral surface of the filter and a tubular second contact surface that contacts the inner peripheral surface of the step portion.
Gas generator. The cover member further includes a third contact surface that extends radially inward from the second contact surface and abuts on the housing wall.
The gas generator according to claim 1. The inner peripheral surface of the step portion extends along the axial direction of the filter.
The inner peripheral surface of the filter and the inner peripheral surface of the stepped portion are flush with each other.
The cover member includes a tubular continuous contact surface in which the first contact surface and the second contact surface are connected.
The gas generator according to claim 1 or 2. The inner peripheral surface of the filter is located outside the inner peripheral surface of the step portion in the radial direction of the filter.
The cover member further includes a fourth contact surface that connects the first contact surface and the second contact surface and abuts on the top surface of the step portion.
The gas generator according to claim 1 or 2. A groove opened in the radial direction of the filter is formed by a portion of the end surface of the filter and the top surface of the step portion excluding the contact portion between the end surface and the top surface.
The cover member has a diameter larger than that of the first contact surface and the second contact surface so as to connect the first contact surface and the second contact surface and to be inserted into the groove through the opening. Including the insertion surface
The gas generator according to claim 1. A combustion chamber in which an ignition unit and a gas generating agent that burns by the operation of the ignition unit are arranged, and
A tubular peripheral wall portion, a first wall portion provided on one end side of the peripheral wall portion, and a combustion chamber provided on the other end side of the peripheral wall portion and defining the combustion chamber together with the peripheral wall portion and the first wall portion. A housing including a second wall portion and having a gas discharge hole that communicates the combustion chamber and the outside of the housing.
A tubular filter, the filter which surrounds the gas generating agent and is arranged in the combustion chamber so that the gas discharge hole is located outside the filter.
It is a gas generator equipped with
The housing wall portion, which is at least one of the first wall portion and the second wall portion, abuts and supports the axial end surface of the filter, and the end surface of the filter in the housing wall portion. A displacement portion is included in the first region, which is a region inside the filter in the radial direction from the contact portion with the filter.
The displacement portion in the housing wall portion is preferentially displaced toward the outside of the combustion chamber over the portion of the housing wall portion excluding the displacement portion when the gas generating agent is burned. It is formed so that it is more easily deformed than the parts other than
Gas generator. The displacement portion is formed to be thinner than the portion of the housing wall portion excluding the displacement portion, at least in a part thereof.
The gas generator according to claim 6. The displacement portion is more easily deformed than the portion of the housing wall portion excluding the displacement portion, is surrounded by the first portion formed in an annular shape and the first portion, and is more than the first portion. Includes a second site that is hard to deform,
The gas generator according to claim 6 or 7. The ignition unit includes a plurality of ignition devices.
The plurality of ignition devices are fixed to the second portion, and the plurality of ignition devices are fixed to the second portion.
Corresponding to each of the plurality of ignition devices, a tubular inner cylinder member surrounding the ignition device is attached along the axial direction of the filter.
The gas generator according to claim 8. The displacement portion includes an annular first portion formed in the housing wall portion that is more easily deformed than a portion other than the displacement portion.
The first portion has a shape bent so as to be recessed toward the outside of the combustion chamber in a cross section orthogonal to the peripheral length direction thereof.
The gas generator according to any one of claims 6 to 9. The displacement portion is formed to be thinner than the portion of the housing wall portion excluding the displacement portion as a whole.
Of the surfaces defining the combustion chamber in the housing wall portion, the displacement surface, which is the surface in the displacement portion, is the surface of the combustion chamber in the axial direction of the filter rather than the peripheral surface radially outside the displacement surface. Includes a bottom surface located on the outer side and a connecting curved surface that connects the bottom surface and the surrounding surface with a curvature.
The gas generator according to claim 7. The housing wall portion has an annular step portion that projects toward the inside of the combustion chamber along the axial direction of the filter.
The axial end face of the filter is abutted and supported by the top surface of the stepped portion.
A portion of the housing wall portion surrounded by the step portion is formed as the displacement portion.
The gas generator according to claim 6. The combustion chamber is provided with a cover member that covers the contact portion between the end surface of the filter and the top surface of the step portion from the inside in the radial direction of the filter so as to straddle the filter and the step portion. ,
The cover member includes a tubular first contact surface that contacts the inner peripheral surface of the filter and a tubular second contact surface that contacts the inner peripheral surface of the step portion.
The gas generator according to claim 12.

Images