JP5423604B2 - Inflator and inflator manufacturing method - Google Patents

Description

  The present invention relates to a pyro-type inflator that generates a gas for expansion by burning a gas generating agent filled in a combustion chamber.

  Conventionally, as a pyro-type inflator, an ignition chamber is provided on the inner peripheral side of an outer case formed by fixing two members divided along the axial direction of a housing in a housing having a substantially cylindrical outer shape. A substantially cylindrical inner case with an opening on the initiator side arranged in the chamber is arranged, and a gas chamber is filled with a gas generating agent between the ignition chamber arranged in the center and the inner case as a combustion chamber. there were. In this inflator, a substantially donut plate-like filter that filters and cools the expansion gas generated by burning the gas generating agent is disposed inside the inner case and on the side of the wall facing the opening. (For example, refer to Patent Document 1).

Japanese Patent Laid-Open No. 10-297418

  However, in the conventional inflator, the inner case does not constitute a combustion chamber, but is provided in order to provide a gap with the outer case, and is expanded toward the opening on the initiator side. Since the inflator is formed so that the combustion chamber is formed separately from the inner case, the holding member that covers the outer peripheral side of the gas generating agent and holds the gas generating agent and the filter, and the gas generating agent And a cushioning material that covers the initiator side. The conventional inflator also includes a substantially cylindrical partition wall that partitions the combustion chamber and the ignition chamber as a separate body from the inner case. In the conventional inflator, the filter side ceiling member in the inner case and the outer case, the bottom wall member on the initiator side in the partition wall and the outer case, and the ceiling member and the bottom member are respectively welded. This is a configuration in which they are fixed to each other. For this reason, the conventional inflator has a large number of parts and a large number of welding locations, so that there is room for improvement in terms of reducing the number of manufacturing steps and cost as a simple configuration.

  This invention solves the above-mentioned subject, and it aims at providing the inflator which can reduce a manufacturing man-hour and cost as a simple structure.

An inflator according to the present invention includes a housing whose outer shape is substantially cylindrical,
It is arranged in the approximate center of the housing and is configured by filling the inside with a charge, and an initiator capable of igniting the charge is arranged on one end wall side along the axial direction of the housing. An ignition chamber,
Inside the housing, the outer periphery of the ignition chamber is arranged so as to surround almost the entire area along the circumferential direction centering on the axis of the housing, and inside it is combusted by the ignition of ignition charge to generate expansion gas A combustion chamber configured to be filled with possible gas generating agents;
A filter disposed in the housing for filtering and cooling the expansion gas generated in the combustion chamber;
A gas discharge port formed in the housing and capable of discharging the expansion gas filtered by the filter to the outside;
And is configured to include
The filter is an inflator configured to be disposed on one end wall side along the axial direction of the housing, with the outer shape being substantially donut plate-shaped,
Housing
An outer case having a gas discharge port and a bottom side member located on the initiator side, and a ceiling side member located on the side away from the initiator;
An inner case that is arranged on the inner peripheral side of the outer case and configured to abut both end sides along the axial direction of the housing against the outer case;
With
An inner case is disposed in the vicinity of the outer case and is formed so that the axial direction is substantially aligned with the axial direction of the housing, and the outer cylindrical portion is concentric with the outer cylindrical portion inside the outer cylindrical portion. A substantially cylindrical inner cylindrical portion and a connecting wall portion that connects one end side of the outer cylindrical portion and the inner cylindrical portion along the axial direction of the housing to each other, and in the axial direction of the housing The part facing the connecting wall is configured as an opening for disposing the filter,
In the inner case, the inner cylinder part is configured by partitioning the combustion chamber and the ignition chamber and filling the inside with a charge transfer agent, and the inner diameter can be fitted with an initiator held by the bottom member. Set to dimensions,
The filter is held in the inner case by closing the filter-side opening in the inner case and inserting the filter into the opening.
The area surrounded by the inner case and the filter can be filled with a gas generating agent, constitutes a combustion chamber,
A communication hole capable of propagating the flame generated during combustion of the transfer charge into the combustion chamber is formed in the inner cylinder portion,
A gas flow path capable of guiding the inflation gas filtered by the filter to the gas discharge port side is formed between the outer case and the inner case.

  In the inflator of the present invention, the inner case arranged on the inner peripheral side of the outer case has an outer cylinder part, an inner cylinder part, and a connecting wall part, and is configured as a rotating body having a substantially U-shaped cross section. At the same time, by inserting the filter into the opening between the outer cylinder and the inner cylinder, the opening is blocked by the filter. A region surrounded by the inner case and the filter is a combustion chamber filled with a gas generating agent, and a region surrounded by the inner cylindrical portion of the inner case is an ignition chamber. That is, in the inflator of the present invention, it is not necessary to separately provide a member that separates the combustion chamber and the ignition chamber, and by inserting the filter into the opening between the outer cylinder portion and the inner cylinder portion. Since it is held in the inner case, a holding member for holding the filter becomes unnecessary, and the number of parts can be reduced as compared with the conventional inflator. In the inflator of the present invention, the inner cylindrical portion of the inner case is configured to fit an initiator disposed on the bottom member side of the outer case, and the inner case extends along the axial direction of the housing. The inner case is configured to abut the outer case on the outer case, so that the inner case is restrained by the initiator from being displaced in the direction perpendicular to the axis of the housing, and the inner case is not displaced in the axial direction. The outer case is housed on the inner peripheral side so as to be restrained by the outer case. Therefore, in the inflator of the present invention, even if the outer case and the inner case are provided, the inner case moves inside with the outer case being pressed by the outer case on both the axial direction ends and the axial orthogonal direction side. Therefore, only the bottom member and the ceiling member in the outer case may be connected to each other using caulking, welding, or the like at the time of manufacture. Compared with, a welding location can be reduced. As a result, in the inflator of the present invention, the number of parts can be reduced and the number of welded parts at the time of manufacturing can be reduced, so that the manufacturing man-hour and the manufacturing cost can be reduced and the manufacturing can be performed at low cost. Can do.

  Therefore, in the inflator of the present invention, the number of manufacturing steps and cost can be reduced with a simple configuration.

  Further, in this type of inflator, the combustion chamber becomes a high pressure during operation, but in the inflator of the present invention, the region away from the filter in the combustion chamber extends over substantially the entire region, and the connecting wall portion and the outer cylindrical portion of the inner case. And the outer case, it is possible to ensure strength, and it is also possible to relatively reduce the plate thickness of each plate member constituting the outer case and the inner case. It is also possible to reduce the weight.

Furthermore, in the inflator of the present invention, the gas flow path is configured to dispose a gas outflow hole disposed in a region overlapping with the filter in the outer cylindrical portion,
It is preferable that the gas outflow hole is arranged to be offset with respect to the gas discharge port on the axial direction side of the housing or the circumferential direction centering on the axial center of the housing.

  In the inflator having the above configuration, the expansion gas flowing out from the gas outflow hole once hits the inner peripheral surface of the outer case in the gas flow path and is discharged to the outside in a deflected state. Therefore, in addition to the filter, it is possible to capture the residue contained in the expansion gas also by the inner peripheral surface of the outer case.

  Furthermore, in the inflator having the above-described configuration, the inner case may be formed from a synthetic resin. However, if the structure is formed by sheet metal pressing, the inner case having strength and heat resistance can be easily obtained. This is preferable because it can be manufactured and the manufacturing cost can be further reduced.

Moreover, the inflator of the present invention is filled with a gas generating agent from the opening on the filter side inside the inner case,
Insert a filter that is set to a size that can close the opening of the inner case into the opening, and hold the filter in the inner case.
The initiator held by the bottom side member in the outer case is fitted to the inner cylinder part in the inner case,
Fill the area inside the inner cylinder part of the inner case with a charge,
After the initiator held by the bottom side member is fitted into the inner case, the ceiling side member arranged so as to cover the outer peripheral side of the filter and the bottom side member can be connected.

  In such an inflator manufacturing method, after the gas generating agent is filled into the inner case from the opening, the gas generating agent is inserted into the opening and held in the inner case so as to close the opening. Can be sealed in the combustion chamber, so that the gas generating agent can be easily charged. Further, in the inflator of the present invention, the inner cylinder part in the inner case partitions the combustion chamber and the ignition chamber, and the transfer charge is filled in a region surrounded by the inner cylinder part in the inner case. In addition, the workability of filling the transfer charge at the time of manufacturing the inflator is also good. Therefore, an inflator can be manufactured easily.

  And in the manufacturing method of the inflator of the present invention, if the inner case has a configuration in which an inner wall portion is provided with a closing wall portion that closes the end portion side away from the connecting wall portion, Fill the area surrounded by the inner cylinder part and the blocking wall part in the inner case from the opening for fixing the initiator, then insert the initiator into the inner cylinder part and fit it into the inner cylinder part If this is done, the ignition chamber can be closed, which makes it easier to handle the charge transfer agent and makes it easier to manufacture the inflator, which is preferable.

It is a schematic longitudinal cross-sectional view of the inflator which is 1st Embodiment of this invention. It is a perspective view of the inner case used in the inflator of FIG. It is a longitudinal cross-sectional view of the inner case of FIG. In the inflator of 1st Embodiment, it is a general | schematic partial expansion longitudinal cross-sectional view explaining the flow of the gas for expansion at the time of an action | operation. It is a schematic longitudinal cross-sectional view of the inflator of the modification of 1st Embodiment. It is a schematic longitudinal cross-sectional view of the inflator which is 2nd Embodiment of this invention. It is a perspective view of the inner case used in the inflator of FIG. It is a longitudinal cross-sectional view of the inner case of FIG. It is a schematic longitudinal cross-sectional view of the inflator which is 3rd Embodiment of this invention. It is a perspective view of the inner case used in the inflator of FIG. It is a longitudinal cross-sectional view of the inner case of FIG.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. The inflator 1 of the first embodiment is used in an airbag device mounted on a vehicle. In the case of the embodiment, the inflator 1 is a disc type whose outer shape is a flat and substantially cylindrical shape. As shown in FIG. 1, the inflator 1 is disposed on a housing 3 whose outer shape is a substantially cylindrical shape, an ignition chamber 26 disposed in the housing 3, and an outer peripheral side of the ignition chamber 26 in the housing 3. Combustion chamber 29, gas generating agent 30 filled in combustion chamber 29, transfer agent 27 charged in ignition chamber 26, initiator 13 disposed in ignition chamber 26 and capable of igniting transfer agent 27, And a filter 24 that is disposed in the housing 3 and filters the expansion gas G1 generated by the combustion of the gas generating agent 30. In the embodiment, the direction along the axial direction of the housing 3 will be referred to as the up-down direction, the ceiling wall 7 side described later in the housing 3 will be the upper side, and the bottom wall 8 side will be the lower side.

  In the embodiment, the housing 3 includes an outer case 4 and an inner case 17 disposed on the inner peripheral side of the outer case 4. The outer case 4 is formed using a steel plate such as stainless steel. The outer case 4 includes a substantially cylindrical peripheral wall 5 and a substantially circular ceiling wall 7 and bottom wall 8 that close both end sides of the peripheral wall 5 in the axial direction. Have. A substantially square annular flange portion 5a projects from the outer peripheral surface slightly below the center of the peripheral wall 5 in the vertical direction (on the bottom wall 8 side). In addition, the expansion gas G1 generated by the combustion of the gas generating agent 30 is discharged to the outside of the peripheral wall 5 on the ceiling wall 7 side, which is a substantially central portion between the flange portion 5a and the ceiling wall 7. A large number of gas discharge ports 6 opened in a substantially circular shape so as to be able to be discharged are disposed over the entire region along the circumferential direction. The outer case 4 includes a ceiling-side member 10 located on the ceiling wall 7 side and away from the initiator 13, and a bottom-side member 11 located on the bottom wall 8 side and located on the initiator 13 side. Yes. In the case of the embodiment, the ceiling-side member 10 constitutes the ceiling wall 7 and the upper portion 5b of the peripheral wall 5 up to the flange portion 5a. The bottom member 11 constitutes the bottom wall 8 and a lower part 5 c that is below the flange portion 5 a in the peripheral wall 5. Further, in the case of the embodiment, the ceiling side member 10 and the bottom side member 11 are regions inside the flange portion 5a in the case of the embodiment, and have regions that overlap each other in the inner and outer directions, and the regions that overlap each other. They are connected to each other by welding over substantially the entire area in the circumferential direction.

  In the bottom member 11 of the outer case 4, an initiator 13 is held at a position substantially at the center of the bottom wall 8. The initiator 13 includes an initiator main body 14 and a synthetic resin holder 15 that holds the initiator main body 14 on the bottom wall 8. The periphery of the initiator 13 is surrounded by an inner cylindrical portion 19 described later of the inner case 17. Thus, it is arranged in the ignition chamber 26. The initiator body 14 is configured to include an ignition part 14a capable of igniting the charge transfer agent 27 filled in the ignition chamber 26, and a pair of conductive pins 14b extending from the ignition part 14a. The holder 15 has a substantially cylindrical shape and holds the periphery of the initiator body 14 so that the conductive pins 14b of the initiator body 14 are exposed to the outside. In the case of the embodiment, 6,6-nylon, It is made of a synthetic resin in which a glass fiber is contained in a polyamide resin such as 6-nylon. In the case of the embodiment, the bottom member 11 and the initiator body 14 in the outer case 4 are integrated by insert molding when the holder 15 is formed, and the initiator 13 is held by the bottom member 11. . In the case of the embodiment, the initiator 13 is configured to be fitted to the inner cylinder portion 19 by press-fitting the holder 15 into the inner cylinder portion 19 of the inner case 17. In the embodiment, the outer diameter R1 (see FIG. 1) of the holder 15 is slightly larger than the inner diameter r1 (see FIG. 3) of the inner cylindrical portion 19 of the inner case 17 in the embodiment. The dimension is set so that it can be press-fitted into the cylindrical portion 19.

  The inner case 17 is a rotating body having a substantially U-shaped cross section. More specifically, as shown in FIGS. 2 and 3, the inner case 17 is disposed in the vicinity of the peripheral wall 5 of the outer case 4. And a substantially cylindrical outer cylindrical portion 18 formed so that its axial direction is substantially along the axial direction of the housing 3, and a substantially cylindrical shape disposed concentrically with the outer cylindrical portion 18 inside the outer cylindrical portion 18. From the inner cylindrical portion 19, the connection wall portion 21 having a substantially donut plate shape connecting the lower end sides (initiator 13 side) of the outer cylindrical portion 18 and the inner cylindrical portion 19 to each other, and the inner cylindrical portion 19 from the connecting wall portion 21. And a substantially disc-shaped blocking wall portion 22 that closes the end portion (upper end side) of the remote side (ceiling wall 7 side). And the inner case 17 is comprised so that the upper side (ceiling wall 7 side) of the area | region between the outer side cylinder part 18 and the inner side cylinder part 19 may be opened. That is, the inner case 17 is configured with a portion facing the connecting wall portion 21 in the axial direction of the housing 3 as an opening 20 for disposing the filter 24. The inner case 17 has an outer diameter dimension (consisting with the outer diameter dimension R2 of the outer cylindrical portion 18, see FIG. 3) slightly smaller than the inner diameter dimension r2 (see FIG. 1) of the bottom member 11 in the outer case 4. The size of the bottom side member 11 is set such that it can be inserted into a part of the peripheral wall 5. Further, the inner case 17 has a width dimension (width dimension on the vertical direction side) W1 (see FIG. 3) along the axial direction side of the housing 3, and a distance between the bottom wall 8 and the ceiling wall 7 in the outer case 4. As substantially the same as the distance D1 (see FIG. 1), the connecting wall portion 21 on one end side along the axial direction (vertical direction) of the housing 3 can be brought into contact with the bottom wall 8 when stored in the outer case 4. In addition, the closing wall portion 22 on the other end side is set so as to be able to contact the ceiling wall 7. In the case of the embodiment, the inner cylinder part 19 has an inner diameter dimension r1 set to about １ ／ of an inner diameter dimension r3 (see FIG. 3) of the outer cylinder part 18.

  In the inner case 17, the upper opening 20 in the region between the outer cylindrical portion 18 and the inner cylindrical portion 19 is closed by a filter 24. That is, the filter 24 is disposed on the ceiling wall 7 side which is one end wall side along the axial direction in the housing 3. The filter 24 has a mesh shape made of a wire mesh or the like, and is configured as a substantially donut plate shape having an opening 24a into which the inner cylindrical portion 19 of the inner case 17 can be press-fitted. This filter 24 is for capturing the residue contained in the expansion gas G1 generated in the combustion chamber 29 and cooling the expansion gas G1. In the case of the embodiment, the filter 24 is configured to be fitted into the inner case 17 by being press-fitted into the opening 20 of the inner case 17. In the case of the embodiment, the filter 24 has an outer diameter R3 (see FIG. 1) slightly larger than an inner diameter r3 of the outer cylindrical portion 18 of the inner case 17, and an inner diameter r4 (see FIG. 1) of the opening 24a. 1) is slightly smaller than the outer diameter R4 (see FIG. 3) of the inner cylindrical portion 19 of the inner case 17, and is set to a size that can be press-fitted into the opening 20 of the inner case 17. Further, in the case of the embodiment, the filter 24 has a thickness dimension T1 (see FIG. 1), which is 1/3 of the width dimension (width dimension on the vertical direction side) W1 along the axial direction side of the housing 3 in the inner case 17. The upper surface 24b is fixed to the outer cylindrical portion 18 of the inner case 17 by press-fitting so that the upper surface 24b is substantially flush with the upper surface of the closing wall portion 22 of the inner case 17.

And in the inflator 1 of embodiment, the area | region enclosed by the inner cylinder part 19 and the obstruction | occlusion wall part 22 in the inner case 17 comprises the ignition chamber 26, and the inner case 17 (the inner cylinder part 19, the outer cylinder part 18, A region surrounded by the connecting wall 21) and the filter 24 constitutes a combustion chamber 29. The ignition chamber 26 is filled with a transfer agent 27 made of a predetermined agent that is ignited and burned by the operation of the initiator body 14 and can generate a flame. The charge transfer agent 27 is formed into a predetermined shape (in the case of the embodiment, granular) by mixing a predetermined fuel together with a binder and the like, and by extrusion molding, press molding, or the like. As the transfer charge can be used a mixture of a generic metal powder and oxidizer as illustrated in B / KNO _3. In the inner cylinder portion 19, a flame that is generated when the transfer charge 27 is burned is located at a position away from the filter 24, and in the case of the embodiment, at a position that is approximately the center of the housing 3 in the axial direction (vertical direction). A communication hole 19 a that can propagate in the combustion chamber 29 is formed. The communication holes 19 a are formed at a plurality of locations (four locations in the embodiment) that are radially centered on the axis C <b> 1 of the housing 3.

  The gas generating agent 30 filled in the combustion chamber 29 is combusted by ignition of the charge transfer agent 27 to generate an expansion gas G1, and is mixed with a predetermined fuel together with a binder or the like, and is subjected to extrusion molding or press molding. The one formed into a predetermined shape is used. As the gas generating agent 30, a non-azidized gas generating agent used as a gas generating agent in a normal inflator can be used. Specifically, a guanidine-based, aminotetrazole-based, triazine-based, hydrazine-based, Triazole type, azodicarbonamide type, bitetrazole type and the like can be used.

  In the outer cylindrical portion 18 of the inner case 17, a gas outflow hole 18 a through which the expansion gas G <b> 1 can flow out is formed in the vicinity of the upper end overlapping the filter 24. The gas outflow holes 18 a are formed at a plurality of locations that are radially centered on the axis C <b> 1 of the housing 3. In the case of the embodiment, as shown in FIGS. 2 and 3, the gas outflow holes 18 a are formed at four locations that are shifted from the communication hole 19 a on the circumferential side around the axis C <b> 1 of the housing 3. Yes. In the case of the embodiment, the gas outflow hole 18 a is offset from the gas discharge port 6 so as to be offset on the axial direction side (vertical direction) of the housing 3 with respect to the gas discharge port 6 formed in the outer case 4. Is also formed at a position on the upper side. Further, the gas outflow hole 18 a is also offset from the gas discharge port 6 on the circumferential direction centered on the axis C <b> 1 of the housing 3. 1 and 4, the gas outlet hole 18a and the gas discharge port 6 are drawn so as to coincide with each other in the circumferential direction, but the flow of the expansion gas G1 can be clearly illustrated on the same cross section. In practice, the gas outflow hole 18a and the gas discharge port 6 are formed at positions shifted on the circumferential side (so as not to be opened on the same cross section). . Further, although the number of gas outlet holes 18a is smaller than that of the gas discharge ports 6, the opening diameter is set larger than the opening diameter of the gas discharge ports 6 as shown in FIG. It is comprised so that it may become larger than the opening area of the exit 6 whole.

  In the inflator 1 of the first embodiment, the gas outflow hole 18a formed between the outer case 4 and the inner case 17 in the outer cylindrical portion 18 of the inner case 17, and the peripheral wall 5 and the inner case in the outer case 4. A gap between the outer cylinder portion 17 and the outer cylinder portion 17 constitutes a gas flow path 31 that guides the expansion gas G1 filtered by the filter 24 to the gas discharge port 6 side. In the inflator 1 of the first embodiment, the expansion gas G1 generated in the combustion chamber 29 is filtered by the filter 24 as shown in FIG. 4, and the residue is captured and cooled. The gas flows out from the gas outflow hole 18a and passes through the gas flow path 31 formed by a gap between the outer cylindrical portion 18 of the inner case 17 and the portion constituting the peripheral wall 5 in the ceiling side member 10 of the outer case 4 to From the discharge port 6, it will discharge radially outside.

  In the case of the embodiment, the inner case 17 is formed by pressing a flat sheet metal material made of stainless steel or the like by drawing or punching. Incidentally, the communication hole 19a formed in the inner cylinder part 19 and the gas outflow hole 18a formed in the outer cylinder part 18 may be previously drilled before drawing, or the inner cylinder part 19 or You may form after forming the outer side cylinder part 18 by drawing.

  Next, manufacture of the inflator 1 of 1st Embodiment is demonstrated. The initiator 13 is integrated with the bottom member 11 in the outer case 4 in advance. First, the inner case 17 is inverted so that the blocking wall portion 22 faces downward, and the transfer charge 27 is removed from the opening 17a (see FIG. 3) for press-fitting the initiator 13 surrounded by the inner cylindrical portion 19. Then, the region (ignition chamber 26) surrounded by the inner cylinder portion 19 and the blocking wall portion 22 is filled. After that, the bottom member 11 is turned upside down so as to be covered from above, the holder 15 of the initiator 13 is press-fitted into the opening 17a of the inner case 17, and the initiator 13 is fixed to the inner case 17, At the same time as closing the ignition chamber 26, the inner case 17 and the bottom member 11 in the outer case 4 are connected. Next, the inner case 17 and the bottom member 11 are reversed so that the closed wall portion 22 of the inner case 17 faces upward, and is surrounded by the outer cylindrical portion 18, the inner cylindrical portion 19, and the connecting wall portion 21 from the opening 20. The gas generating agent 30 is filled in a region to be sealed. Thereafter, the filter 24 is press-fitted into the opening 20, the filter 24 is fixed to the inner case 17, and the combustion chamber 29 is closed. Further, the ceiling-side member 10 of the outer case 4 is covered from above so as to cover the outer peripheral side of the filter 24, and the ceiling-side member 10 and the bottom-side member 11 are welded to each other inside the flange portion 5a. If it does, the ceiling side member 10 and the bottom side member 11 can be connected, and the inflator 1 can be manufactured.

  In the inflator 1 according to the first embodiment, when an operation signal is input from a control device via a lead wire (not shown) while being mounted on a vehicle together with an airbag device, the initiator body 14 burns the transfer charge 27. Thus, the gas generating agent 30 filled in the combustion chamber 29 is combusted by propagating the flame from the charge transfer agent 27 through the communication hole 19a into the combustion chamber 29. Then, the inflation gas G1 generated by burning the gas generating agent 30 is discharged from the gas discharge port 6 to the outside of the inflator 1 through the filter 24 and the gas flow path 31 to inflate the airbag of the airbag device. Will be allowed to.

  And in the inflator 1 of 1st Embodiment, the inner case 17 arrange | positioned at the inner peripheral side of the outer case 4 has the outer side cylinder part 18, the inner side cylinder part 19, and the connection wall part 21, and cross-section is substantially U. It is configured as a letter-shaped rotating body, and the filter 24 is press-fitted (inserted) into the opening (opening 20) between the outer cylinder 18 and the inner cylinder 19 so that the opening 20 is filtered. It will be blocked by. A region surrounded by the inner case 17 and the filter 24 is a combustion chamber 29 in which the gas generating agent 30 is filled, and a region surrounded by the inner cylindrical portion 19 of the inner case 17 is an ignition chamber 26. That is, in the inflator 1 of the first embodiment, a member that separates the combustion chamber 29 and the ignition chamber 26 may not be separately provided, and the filter 24 may be disposed between the outer cylinder portion 18 and the inner cylinder portion 10. Since it is fixed (held) to the inner case 17 by being press-fitted (inserted) into the opening 20, a holding member for holding the filter is also unnecessary, and the number of parts is smaller than that of a conventional inflator. Can also be reduced. Moreover, in the inflator 1 of 1st Embodiment, the inner cylinder part 19 of the inner case 17 is the structure which press-fits (fits) the initiator 13 (holder 15) arrange | positioned by the bottom side member 11 side in the outer case 4. FIG. The inner case 17 is configured so that both end sides (the connecting wall portion 21 and the blocking wall portion 22) along the axial direction of the housing 3 are brought into contact with the bottom wall 8 and the ceiling wall 7 of the outer case 4. Since the inner case 17 is configured, the displacement movement of the housing 3 in the direction orthogonal to the axis is suppressed by the initiator 13 (holder 15), and the displacement movement of the housing 3 in the axial direction is suppressed by the outer case 4. As a result, the outer case 4 is housed on the inner peripheral side. Therefore, in the inflator 1 according to the first embodiment, even if the outer case 4 and the inner case 17 are provided, the inner case 17 can be held by the outer case 4 at both ends on the axial direction side and on the axis orthogonal direction side. In this state, it is housed in the outer case 4 without moving inside, so that only the bottom member 11 and the ceiling member 10 in the outer case 4 are connected to each other using welding at the time of manufacture. What is necessary is just to assemble | attach and can reduce a welding location compared with the conventional inflator. As a result, in the inflator 1 according to the first embodiment, the number of parts can be reduced and the number of welds at the time of manufacture can be reduced. Can be manufactured.

  Therefore, in the inflator 1 of the first embodiment, the number of manufacturing steps and cost can be reduced as a simple configuration.

  Further, in this type of inflator, the combustion chamber becomes high pressure during operation. However, in the inflator 1 of the first embodiment, the region away from the filter 24 in the combustion chamber 29 is connected to the inner case 17 over substantially the entire region. Since the wall portion 21 and the outer cylindrical portion 18 and the outer case 4 have a two-layer structure, the strength can be secured, and the plate thickness of each plate material constituting the outer case 4 and the inner case 17 can be set. It becomes possible to make it relatively thin, and it is also possible to reduce the weight.

  Furthermore, in the inflator 1 according to the first embodiment, the gas outflow hole 18 a formed in the region overlapping the filter 24 in the outer cylindrical portion 18 of the inner case 17 has an axial side of the housing 3 with respect to the gas discharge port 6. (On the vertical direction side) and on the circumferential side centered on the axis C1 of the housing 3 are arranged offset. Therefore, in the inflator 1 of the first embodiment, the expansion gas G1 flowing out from the gas outflow hole 18a once hits the inner peripheral surface of the peripheral wall 5 of the outer case 4 in the gas flow path 31 and is deflected. In this state, since the gas is discharged from the gas outlet 6 to the outside, the residue contained in the expansion gas G1 is captured by the inner peripheral surface of the peripheral wall 5 of the outer case 4 in addition to the filter 24. Can do. In the embodiment, the gas outflow hole 18a is offset with respect to the gas discharge port 6 both on the axial direction side of the housing 3 and on the circumferential direction centered on the axis C1, but of course, The outflow hole may be arranged so as to be offset only on the axial direction side or on the circumferential direction side with respect to the gas discharge port. If the above points are not taken into account, the gas outflow holes may of course be arranged at positions substantially coincident with the gas discharge ports on the axial direction side and the circumferential direction side.

  Furthermore, in the inflator 1 of the first embodiment, since the inner case 17 is made of sheet metal and is formed by pressing, the metal inner case 17 having heat resistance can be easily manufactured. The manufacturing cost can be further reduced. Of course, the inner case may be formed by casting or the like.

  In addition, in the inflator 1 of the first embodiment, after the gas generating agent 30 is filled into the inner case 17 from the opening 20 during manufacture, the filter 24 is press-fitted into the inner case 17 so as to close the opening 20. In this case, since the gas generating agent 30 can be sealed in the combustion chamber 29, the filling operation of the gas generating agent 30 is easy. Further, in the inflator of the first embodiment, the inner cylinder portion 19 in the inner case 17 partitions the combustion chamber 29 and the ignition chamber 26, and the transfer charge 27 is surrounded by the inner cylinder portion 19 in the inner case 17. Since the region is filled, the workability of the filling work of the transfer charge 27 at the time of manufacture is also good. Therefore, in the first embodiment, the inflator 1 can be easily manufactured.

  Furthermore, in the inflator 1 of the first embodiment, the inner wall portion 19 of the inner case 17 is provided with a blocking wall portion 22 that closes the end portion on the side away from the connecting wall portion 21. . Therefore, in the inflator 1 of the first embodiment, when the inflator 1 is manufactured, from the opening 17a for fixing the holder 15 of the initiator 13 to the region surrounded by the inner cylindrical portion 19 and the blocking wall portion 22 in the inner case 17. If the charge transfer agent 27 is filled and then the holder 15 of the initiator 13 is press-fitted into the inner cylindrical portion 19, the ignition chamber 26 can be closed, so that the transfer charge 27 can be handled easily and the inflator 1 can be manufactured more easily. can do.

  Of course, if such a point is not taken into consideration, an inner case 17A having a configuration without an obstruction wall portion may be used as in the inflator 1A of the modification shown in FIG. The inflator 1A has the same configuration as the inflator 1 except that the inner case 17A does not include a blocking wall portion and the upper side of the inner cylindrical portion 19A is opened. A detailed description will be omitted by adding “A” to the end of the reference numeral. Further, in the inflator 1A, the inner case 17A is configured such that the one end side connecting wall portion 21A along the axial direction (vertical direction) of the housing 3A is in contact with the bottom wall 8A of the outer case 4A. The upper end of the inner cylindrical portion 19A is configured to be able to contact the ceiling wall 7A of the outer case 4A. In manufacturing the inflator 1A, first, the holder 15A of the initiator 13A held by the bottom side member 11A is press-fitted into the opening 17a for fixing the initiator 13A in the inner case 17A, so that the initiator 13A is fixed to the inner cylindrical portion 19A of the inner case 17A. Thereafter, the gas generating agent 30A is filled from the opening 20 of the inner case 17A into the area surrounded by the outer cylindrical portion 18A, the inner cylindrical portion 19A, and the connecting wall portion 21A, and the filter 24A is press-fitted into the opening 20A. 24A is fixed to the inner case 17A, and the combustion chamber 29A is closed. Next, after filling the region surrounded by the inner cylindrical portion 19A in the inner case 17A with the transfer charge 27A from the upper opening, the ceiling side member 10A of the outer case 4A is moved upward so as to cover the outer peripheral side of the filter 24A. If the ceiling side member 10A and the bottom side member 11A are welded to each other inside the flange portion 5a, the inflator 1A can be manufactured.

  In the inflator 1 according to the first embodiment, since the inner case 17 includes the blocking wall portion 22, the filter 24 is necessarily disposed on the side away from the initiator 13. In the case of using the inner case 17A having a configuration that does not include the blocking wall portion as in 1A, an area where the initiator is close to the filter and the outer peripheral side is surrounded by the filter (in FIG. 1, the blocking wall of the inner case 17). It is also possible to arrange in the area where the part 22 is arranged. In such a configuration, the filter is disposed on the bottom wall side together with the initiator, and the connecting wall portion of the inner case is disposed on the ceiling wall side.

  Next, the inflator 33 which is 2nd Embodiment of this invention is demonstrated. As shown in FIG. 6, the inflator 33 has the same configuration as the inflator 1 described above except that the outer shape of the outer case 34 and the inner case 17B constituting the housing 3B are slightly different. The same reference numerals are suffixed with “B” and detailed description is omitted.

  The outer case 34 is formed by using a steel plate such as stainless steel. Like the outer case 34 described above, the outer case 34 has a substantially cylindrical peripheral wall 35 and a substantially disk shape that closes both axial ends of the peripheral wall 35. A gas discharge port capable of discharging the expansion gas G2 generated by burning the gas generating agent 30B to the outside at the approximate center of the peripheral wall 35 on the axial direction side. A number 36 is disposed over the entire area along the circumferential direction. Similarly to the outer case 4 described above, the outer case 34 is located on the ceiling wall 37 side and on the side away from the initiator 13B, and on the bottom wall 38 side and on the initiator 13B side. And a bottom side member 41. The ceiling side member 40 constitutes a ceiling wall 37 and a peripheral wall 35, and the bottom side member 41 has a bottom wall 38 and extends upward from the outer peripheral edge of the bottom wall 38 to the inner peripheral side of the peripheral wall 35. A flange portion 41a is provided. Then, the ceiling side member 40 and the bottom side member 41 are caulked so that the extended portion 40a formed to extend from the peripheral wall 35 in the ceiling side member 40 is pressed against the lower surface side of the bottom wall 38, Are interconnected.

  Also in the inflator 33 of the second embodiment, the initiator 13B is held at the approximate center of the bottom wall 38, and the initiator 13B is placed on the bottom side via the synthetic resin holder 15B in the same manner as the inflator 1 described above. It is integrated with the member 41.

  The inner case 17B has the same configuration as the inner case 17 except for the position and shape of the gas outflow hole formed in the outer cylindrical portion 18B, and the same member has “B” at the end of the same reference numeral. The detailed description is omitted. The inner case 17B also allows the connecting wall portion 21B, which is one end side along the axial direction of the housing 3B, to come into contact with the bottom wall 38 when being stored in the outer case 34, and the other end side is closed. The wall portion 22B is set so as to be able to contact the ceiling wall 37. The outer cylindrical portion 18B of the inner case 17B is configured by partially notching a region in the vicinity of the upper end serving as the periphery of the opening 20B. In the case of the embodiment, the notches 18b are formed at three locations that are radially centered on the axis C2 of the housing 3B (see FIGS. 7 and 8), each of which is approximately 1 of the circumference of the outer cylindrical portion 18B. It is formed by cutting out about / 6. Further, as shown in FIG. 6, these notches 18b are formed only in a region overlapping the filter 24B when the filter 24B is press-fitted into the opening 20B. 3B is arranged offset on the axial direction side (vertical direction side). In the inner case 17B of the embodiment, the cutout portion 18b constitutes a gas outflow hole, and the cutout portion 18b has a larger opening area than the entire opening area of the gas discharge port 36. Is set.

  In the inflator 33 of the second embodiment, a notch portion 18b as a gas outflow hole formed between the outer case 34 and the inner case 17B and formed in the outer cylindrical portion 18B of the inner case 17B, and a peripheral wall in the outer case 34 The gap between the inner cylinder 17B and the outer cylindrical portion 18B of the inner case 17B constitutes a gas flow path 42 that guides the expansion gas G2 filtered by the filter 24B to the gas discharge port 36 side. In the inflator 33 according to the second embodiment, the expansion gas G2 generated in the combustion chamber 29B constituted by the region surrounded by the inner case 17B and the filter 24B is also filtered as shown in FIG. In a state where the residue is trapped and cooled and flows out from the notch 18b (gas outflow hole), the space between the outer cylindrical portion 18B of the inner case 17B and the peripheral wall 35 of the outer case 34 is reduced. The gas is discharged radially from the gas discharge port 36 through the gas flow path 42 including the gap.

  Further, in the inflator 33 of the second embodiment, like the inflator 1, the transfer charge 27B is filled into the ignition chamber 26B through the opening 17a for press-fitting the initiator 13B, and the holder 17 is filled in the opening 17a of the inner case 17B. 15B is press-fitted to fix the initiator 13B and the inner case 17B, then the gas generating agent 30B is filled from the opening 20B of the inner case 17B, the filter 24B is press-fitted into the opening 20B, and then the ceiling side of the outer case 34 If the extended portion 40a of the member 40 is caulked so as to be pressed against the lower surface side of the bottom wall 38, it can be manufactured.

  Next, an inflator 44 that is a third embodiment of the present invention will be described. As shown in FIG. 9, the inflator 44 has the same configuration as the inflator 1 described above except that the outer shape of the outer case 45 and the inner case 17C constituting the housing 3C are slightly different. A detailed description is omitted by adding “C” to the end of the same reference numeral.

  The outer case 45 is formed using a steel plate such as stainless steel, and includes a substantially cylindrical peripheral wall 46, a substantially disc-shaped ceiling wall 47 and a bottom wall 48 that block both end sides of the peripheral wall 46 in the axial direction. And a substantially cylindrical gas discharge portion 49 formed so as to protrude upward from the ceiling wall 47. The gas discharge portion 49 extends upward so as to be continuous from the ceiling wall 47 and is formed by closing the distal end side, and has an outer diameter smaller than that of the peripheral wall 46 so that the axis coincides with the peripheral wall 46. ,It is configured. In the case of the embodiment, the gas discharge portion 49 is configured such that the outer diameter dimension is slightly larger than the outer diameter dimension of the inner cylindrical portion 19C of the inner case 17C. In the gas discharge portion 49, a plurality of gas discharge ports 50 capable of discharging the expansion gas G3 generated by burning the gas generating agent 30C to the outside are formed radially about the axis C3 of the housing 3C. ing. Similarly to the outer cases 4 and 34 described above, the outer case 45 includes a ceiling side member 51 located on the ceiling wall 47 side and away from the initiator 13C, and a bottom wall 48 side and the initiator 13C side. And a bottom side member 52 located at the bottom. The ceiling side member 51 constitutes a ceiling wall 37, a peripheral wall 35, and a gas discharge part 49. The bottom side member 52 has a substantially disk shape as an outer shape and forms a bottom wall 48. Then, the ceiling-side member 51 and the bottom-side member 52 are caulked so that the extended portion 51 a formed to extend from the peripheral wall 46 in the ceiling-side member 51 is pressed against the lower surface side of the bottom wall 48. Are interconnected.

  Also in the inflator 44 of the third embodiment, an initiator 13C is held at substantially the center of the bottom wall 48, and the initiator 13C is similar to the inflators 1 and 33 described above via a synthetic resin holder 15C. It is integrated with the bottom member 52.

  The inner case 17C has the same configuration as the inner case 17 described above except that the gas outflow hole is not provided in the outer cylindrical portion 18C and the width dimension of the inner cylindrical portion 19C in the vertical direction is different. The same members are denoted by “C” at the end of the same reference numerals, and detailed description thereof is omitted. The inner cylinder portion 19C of the inner case 17C has a width dimension (width dimension on the vertical direction side) W2 along the axial direction side of the housing 3C so as to provide a gap between the closing wall portion 22C and the ceiling wall 47. The outer cylindrical portion 18C is configured to be smaller than the width dimension W3 on the vertical direction side (see FIG. 11). In the case of the embodiment, the width dimension W2 on the vertical direction side of the inner cylinder part 19C is set to about 5/6 of the width dimension W3 on the vertical direction side of the outer cylinder part 18C. Further, the width dimension W3 on the vertical direction side of the outer cylindrical portion 18C enables the connecting wall portion 21C on one end side along the axial direction of the housing 3C to come into contact with the bottom wall 48 when stored in the outer case 45. In addition, the upper end of the other end side is set to a dimension that can contact the ceiling wall 47.

  In the inner case 17C, as shown in FIGS. 10 and 11, no gas outflow hole is formed in the outer cylindrical portion 18C, but the blocking wall portion 22C is disposed below the upper end of the outer cylindrical portion 18C. When the filter 24C is press-fitted into the opening 20C, a region that is not covered by the inner cylindrical portion 19C is formed on the inner peripheral surface side of the filter 24C (see FIG. 9). In the inner case 17C of the embodiment, the expansion gas G3 flows out from the step (gap) region 17b between the upper surface of the blocking wall portion 22C and the upper end of the outer cylindrical portion 18C. And also in the inflator 44 of this 3rd Embodiment, the area | region 17b of the clearance gap between the closed wall part 22C and the ceiling wall 47 is the axial direction side (up-down direction side) of the housing 3C with respect to the gas discharge port 50. It is arranged offset. Also in the inner case 17C of the third embodiment, the gap region 17b is a region on the inner peripheral surface side exposed from the inner cylindrical portion 19C in the filter 24 when the filter 24C is press-fitted into the opening 20C. The gas discharge port 50 is set to be larger than the entire opening area.

  In the inflator 44 of the third embodiment, a region between the outer case 45 and the inner case 17C and surrounded by the closing wall portion 22C of the inner case 17C and the gas discharge portion 49 of the outer case 45 is a filter. A gas flow path 53 for guiding the expansion gas G3 filtered by 24C to the gas discharge port 50 side is configured. In the inflator 44 of the third embodiment, the expansion gas G3 generated in the combustion chamber 29C constituted by the region surrounded by the inner case 17C and the filter 24C is also filtered as shown in FIG. In the state where the residue is trapped and cooled, it flows out from the region 17c of the gap between the closed wall portion 22C and the ceiling wall 47, and passes through the gas flow path 53 (gas discharge portion 49). The gas is discharged radially from the gas discharge port 50 to the outside.

  The inflator 44 of the third embodiment also fills the ignition chamber 26C with the transfer charge 27C from the opening 17a for press-fitting the initiator 13C, similarly to the inflators 1 and 33 described above, and opens the opening 17a of the inner case 17C. The holder 13C is press-fitted into the inner case 17 to fix the initiator 13C and the inner case 17C, and then the gas generating agent 30C is filled from the opening 20C of the inner case 17C. After the filter 24C is press-fitted into the opening 20C, the outer case 45 It can be manufactured by caulking the extended portion 51a of the ceiling side member 51 so as to be pressed against the lower surface side of the bottom wall 48.

  In the inflator 44 of the third embodiment, the gas discharge port 50 is formed not in the area of the peripheral wall 46 but in the gas discharge portion 49 formed so as to protrude upward from the ceiling wall 47. With respect to the space | gap area | region 17c, it is offset and arrange | positioned by the axial direction side (up-down direction side) of the housing 3C. Therefore, also in the inflator 44 of the third embodiment, the expansion gas G3 flowing out from the gap region 17c once hits the inner peripheral surface of the gas discharge portion 49 and is deflected from the gas discharge port 50. Since the gas is discharged to the outside, the residue contained in the expansion gas G3 can be captured also by the inner peripheral surface of the gas discharge portion 49 in addition to the filter 24C.

  In the inflators 1, 1A, 33, and 44 of the embodiment, the filters 24, 24A, 24B, and 24C are provided with outer diameters of the outer cylindrical portions 18, 18A, 18B, and 18C in the inner cases 17, 17A, 17B, and 17C. The inner diameter is slightly larger than the inner diameter, and the inner diameter of the opening 24a is slightly smaller than the outer diameter of the inner cylindrical portions 19, 19A, 19B, 19C in the inner cases 17, 17A, 17B, 17C. Both are configured to be press-fitted into the opening 20 of the inner case 17. If the filter is held, the manner of press-fitting the filter into the inner case is not limited to the embodiment, but only the outer diameter is slightly larger than the inner diameter of the outer cylinder, and the inner diameter of the opening is the inner cylinder. It may be configured to allow insertion into the inner case opening only on the outside, and conversely, only the inner diameter of the opening is slightly smaller than the outer diameter of the inner cylinder, It is good also as a structure which is set to the dimension which can be inserted in an outer side cylinder part, and is press-fit in the opening of an inner case only inside. Note that the manner of holding the filter in the inner case is not limited to press-fitting. For example, a male screw groove is formed on the outer peripheral surface of the filter, and a female screw groove corresponding to the inner peripheral surface of the outer wall portion of the inner case is formed. And it is good also as a structure which hold | maintains a filter to an inner case by screw coupling | bonding.

  In addition, in the inflators 1, 1A, 33, and 44 of the embodiment, the initiators 13, 13A, 13B, and 13C (holders 15, 15A, 15B, and 15C) are connected to the inner cylindrical portions 19 in the inner cases 17, 17A, 17B, and 17C, The holders 15, 15A, 15B, and 15C are fixed to the inner cylindrical portions 19, 19A, 19B, and 19C by press-fitting into the 19A, 19B, and 19C. Any other means can be used as appropriate as long as the holder can be fitted to the inner cylindrical portion.

  Further, in the inflators 1, 1A, 33, and 44 of the embodiment, the initiators 13, 13A, 13B, and 13C are made of synthetic resin as the holders 15, 15A, 15B, and 15C, and the bottoms of the outer cases 4, 4A, 34, and 45 are made. Although it is configured integrally with the side members 11, 11B, 41, and 52, the manner of fixing the initiator to the bottom side member is not limited to this. For example, the initiator holder is made of metal and welding is used. The initiator may be fixed to the bottom member and the initiator may be held on the bottom member.

  Furthermore, in the embodiment, the disk type inflator whose outer shape is substantially disk-shaped has been described as an example, but the present invention can also be applied to a cylinder-type inflator whose outer shape is substantially cylindrical. is there.

1, 1A, 33, 44 ... Inflator,
3, 3A, 3B, 3C ... housing,
4, 4A, 34, 45 ... outer case,
6, 6A, 6B, 50 ... gas outlet,
10, 10A, 40, 51 ... ceiling side member,
11, 11B, 41, 52 ... bottom member,
13, 13A, 13B, 13C ... initiator,
17, 17A, 17B, 17C ... inner case,
18, 18A, 18B, 18C ... outer cylinder part,
18a ... Gas outflow hole,
18b ... notch (gas outflow hole),
19, 19A, 19B, 19C ... inner cylinder part,
19a ... Communication hole
20, 20A, 20B, 20C ... opening,
21, 21A, 21B, 21C ... connecting wall,
22, 22B, 22C ... obstruction wall,
24, 24A, 24B, 24C ... filter,
26, 26A, 26B, 26C ... ignition chamber,
27, 27A, 27B, 27C ...
29, 29A, 29B, 29C ... combustion chamber,
30, 30A, 30B, 30C ... gas generating agent,
31, 42, 53 ... gas flow path,
G1, G2, G3... Expansion gas.

Claims (5)

A housing whose outer shape is substantially cylindrical,
The housing is arranged at substantially the center and is filled with a charge transfer agent, and an initiator capable of igniting the transfer charge is provided on one end wall side along the axial direction of the housing. An ignition chamber composed of
In the housing, the outer peripheral side of the ignition chamber is disposed so as to surround substantially the entire region along the circumferential direction centering on the axis of the housing, and is combusted and expanded inside by ignition of the transfer charge. A combustion chamber configured to be filled with a gas generating agent capable of generating a working gas;
A filter disposed in the housing for filtering and cooling the expansion gas generated in the combustion chamber;
A gas discharge port formed in the housing and capable of discharging the inflation gas filtered by the filter to the outside;
And is configured to include
The filter is an inflator configured to be disposed on one end wall side along the axial direction of the housing, with the outer shape being substantially donut plate-shaped,
The housing comprises:
An outer case having a gas discharge port, and a bottom side member located on the initiator side, and a ceiling side member located on a side away from the initiator;
An inner case arranged on the inner peripheral side of the outer case and configured to abut both end sides along the axial direction of the housing against the outer case;
With
The inner case is disposed in the vicinity of the outer case and is formed with a substantially cylindrical outer tube portion whose axial direction is substantially along the axial direction of the housing, and the outer tube inside the outer tube portion. A substantially cylindrical inner cylindrical portion arranged concentrically with the portion, and a connecting wall portion that mutually connects one end side along the axial direction of the housing in the outer cylindrical portion and the inner cylindrical portion, A portion facing the connecting wall portion in the axial direction of the housing is configured as an opening for disposing the filter;
In the inner case, the inner cylinder portion is configured to partition the combustion chamber and the ignition chamber and to be filled with the transfer charge, and an inner diameter dimension is held by the bottom member. The initiator is set to a dimension that can be fitted,
The filter is held in the inner case by closing the filter-side opening in the inner case and inserting the filter into the opening.
A region surrounded by the inner case and the filter can be filled with the gas generating agent, and constitutes the combustion chamber.
A communication hole capable of propagating a flame generated during combustion of the transfer charge into the combustion chamber is formed in the inner cylinder portion,
An inflator characterized in that a gas flow path capable of guiding the expansion gas filtered by the filter to the gas discharge port side is formed between the outer case and the inner case. The gas flow path is configured to include a gas outflow hole disposed in a region overlapping the filter in the outer cylindrical portion,
The gas outflow hole is arranged to be offset with respect to the gas discharge port on the axial direction side of the housing or on the circumferential direction centering on the axial center of the housing. Item 10. The inflator according to Item 1.   The inflator according to claim 1 or 2, wherein the inner case is made of sheet metal by press working. A housing whose outer shape is substantially cylindrical,
The housing is arranged at substantially the center and is filled with a charge transfer agent, and an initiator capable of igniting the transfer charge is provided on one end wall side on the axial direction side of the housing. An ignition chamber configured;
In the housing, the outer peripheral side of the ignition chamber is disposed so as to surround substantially the entire region along the circumferential direction with the shaft center of the housing as a center, and is combusted and expanded by combustion of the transfer charge inside. A combustion chamber configured to be filled with a gas generating agent capable of generating a working gas;
A filter disposed in the housing for filtering and cooling the expansion gas generated in the combustion chamber;
A gas discharge port formed in the housing and capable of discharging the inflation gas filtered by the filter to the outside;
And is configured to include
The filter is a method of manufacturing an inflator having a configuration in which the outer shape is substantially donut plate shape, and is disposed on one end wall side along the axial direction of the housing,
The housing comprises:
An outer case having a gas discharge port, and a bottom side member located on the initiator side, and a ceiling side member located on a side away from the initiator;
An inner case arranged on the inner peripheral side of the outer case and configured to abut both end sides along the axial direction of the housing against the outer case;
With
The inner case is disposed in the vicinity of the outer case and is formed with a substantially cylindrical outer tube portion whose axial direction is substantially along the axial direction of the housing, and the outer tube inside the outer tube portion. A substantially cylindrical inner cylindrical portion arranged concentrically with the portion, and a connecting wall portion that mutually connects one end side along the axial direction of the housing in the outer cylindrical portion and the inner cylindrical portion, A portion facing the connecting wall portion in the axial direction of the housing is configured as an opening for disposing the filter;
A communication hole capable of propagating a flame generated during combustion of the transfer charge into the combustion chamber is formed in the inner cylinder portion,
Between the outer case and the inner case, a gas flow path capable of guiding the expansion gas filtered by the filter to the gas discharge port side is formed,
The gas generating agent is filled into the inner case from the filter side opening,
The filter set to a size capable of closing the opening of the inner case is inserted into the opening, and the filter is held in the inner case,
The initiator held by the bottom member in the outer case is fitted into the inner cylindrical portion in the inner case,
In the inner case in the inner case, the region is filled with the transfer charge,
After the fitting of the initiator held by the bottom member to the inner case, the ceiling member disposed so as to cover the outer peripheral side of the filter is connected to the bottom member. A method for manufacturing an inflator.   5. The inflator according to claim 4, wherein the inner case includes a blocking wall portion that closes an end portion of the inner cylindrical portion that is away from the connection wall portion. Production method.

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