JP2009286217A - Gas generator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a gas generator having a relatively simple and compact constitution for obtaining the desired combustion characteristic. <P>SOLUTION: A cylinder type gas generator 1A comprises a long housing 10, a combustion chamber 16 and a decompression chamber 17 provided in the housing 10, a partition member 40, an igniter 30, and a filter 60. The partition member 40 includes a cylindrical part 41 for demarcating the decompression chamber 17 in the radial direction into an inner decompression chamber 17a and an outer decompression chamber 17b, and a flange part 42 which continuously extends from the cylindrical part 41 and demarcates a space inside the housing 10 into the combustion chamber 16 and the decompression chamber 17. The combustion chamber 16 and the inner decompression chamber 17a are communicated with each other via a first communication hole 43, and the inner decompression chamber 17a and the outer decompression chamber 17b are communicated with each other via a second communication hole 44. The filter 60 is arranged in the outer decompression chamber 17a so as to cover the second communication hole 44. The cylindrical part 41 and the flange part 42 of the partition member 40 function as a pressure bulkhead. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a gas generator incorporated in an airbag device as an occupant protection device mounted on an automobile or the like, and more particularly to a so-called cylinder type gas generator having a long cylindrical outer shape.

  2. Description of the Related Art Conventionally, airbag devices, which are occupant protection devices, have been widely used from the viewpoint of protecting occupants such as automobiles. An airbag device is installed in a vehicle or the like for the purpose of protecting an occupant from an impact caused by the collision of a vehicle or the like, and is an airbag that is deployed by instantly inflating and deploying the airbag at the time of a vehicle or the like collision. It is intended to catch the passenger's body. The gas generator is a device that is incorporated in the airbag device and inflates and deploys the airbag by instantaneously generating gas when a vehicle or the like collides.

  There are various types of gas generators based on specifications such as installation position and output with respect to a vehicle or the like. One of them is a gas generator having a structure called “cylinder type”. The cylinder type gas generator has a long cylindrical shape, and is suitably incorporated in a side airbag device, an airbag device for a passenger seat, or the like.

  In general, in a cylinder-type gas generator, an igniter and a charge transfer agent are disposed at one end of the housing in the axial direction, a gas generating agent is disposed at a substantially central portion in the axial direction, and a filter and A gas outlet is arranged. In the cylinder-type gas generator having the above-described configuration, the flame generated by the operation of the igniter is transmitted to the gas generating agent through the combustion of the transfer agent, whereby the gas generating agent burns and the high temperature and high pressure combustion gas is generated. Will occur. The generated high-temperature and high-pressure combustion gas is discharged from the gas outlet through the filter to the outside of the housing, and used for inflation and deployment of the airbag. In addition, as literature which disclosed the specific structure of the cylinder type gas generator of such a structure, Unexamined-Japanese-Patent No. 2005-313812 (patent document 1) and Unexamined-Japanese-Patent No. 2001-151069 (patent document 2), for example. Etc.

Further, as a cylinder type gas generator having a configuration different from the cylinder type gas generator having the above-described configuration, there is one disclosed in JP 2005-335649 A (Patent Document 3). In the cylinder-type gas generator disclosed in Patent Document 3, one igniter is disposed at each of one end and the other end in the axial direction of the housing, and a cylindrical filter is provided at the periphery of the central portion in the axial direction. A gas outlet is provided, and the gas generating agent is disposed in almost all regions other than the portion where the filter is disposed inside the housing. In the cylinder type gas generator having the above-described configuration, when one of the igniters is operated, the gas generating agent burns to generate high-temperature and high-pressure combustion gas, and the generated high-temperature and high-pressure combustion gas passes through the filter to generate gas. The air bag is expanded and deployed by being discharged from the jet port, and the other igniter is activated after the one igniter is activated, and the remaining gas generating agent is burned to generate combustion gas. The gas is discharged from the gas outlet through the filter and supplied to the airbag. Thereby, in the cylinder type gas generator having the above configuration, the progress of the cooling of the combustion gas is delayed, and the deployment time of the airbag is maintained longer.
JP 2005-313812 A JP 2001-151069 A JP 2005-335649 A

  By the way, in the cylinder type gas generator, it is important to optimize the output characteristics of the combustion gas in accordance with the specifications of the incorporated airbag apparatus. Here, the output characteristics of the combustion gas that needs to be optimized include the flow rate and temperature of the combustion gas released from the gas outlet. In addition, it is one of important output characteristics that the combustion gas discharged from the gas outlet does not contain as much residue (slag) as possible.

  In order to obtain a desired flow rate of the combustion gas discharged from the gas outlet, it is necessary to efficiently burn the gas generating agent in the combustion chamber. For this purpose, the pressure in the combustion chamber needs to be maintained at a high pressure during operation. If the pressure in the combustion chamber is not maintained at a sufficiently high pressure, the combustion of the gas generating agent is sufficiently promoted. Therefore, the unburned gas generating agent is generated, and the flow rate of the combustion gas released from the gas outlet is insufficient. Further, in order to obtain a desired flow rate of the combustion gas discharged from the gas outlet, the high-pressure combustion gas generated in the combustion chamber is sufficiently depressurized inside the cylinder type gas generator and then externally It is also important to release it. For this purpose, it is necessary to provide a decompression chamber inside the cylinder type gas generator. If no decompression chamber is provided, high-pressure combustion gas will be supplied to the airbag as it is. The air bag will be seriously damaged.

  In order to optimize the temperature of the combustion gas discharged from the gas outlet, it is necessary to sufficiently cool the high-temperature combustion gas generated in the combustion chamber and then discharge it to the outside. For this purpose, it is necessary to provide some cooling means in the above-described decompression chamber. If the cooling means is not provided, combustion gas that is insufficiently cooled and still hot is supplied to the airbag. In this case, too, the airbag is seriously damaged.

  In order to prevent slag from being contained as much as possible in the combustion gas discharged from the gas outlet, it is necessary to efficiently remove slag from the combustion gas generated in the combustion chamber. For this purpose, it is preferable to provide some filtering means in the above-described decompression chamber. If the filtering means is not provided, the combustion gas discharged from the gas jet outlet contains a lot of high-temperature slag. In this case, too, the airbag is seriously damaged.

  As described above, in order to obtain desired output characteristics in the cylinder type gas generator, a decompression chamber is provided in the cylinder type gas generator, and a combustion gas cooling means and a filtration means are provided in the decompression chamber. It is necessary. Here, in the cylinder type gas generator, generally, a pressure partition is provided inside the cylinder type gas generator as a decompression chamber, and the space inside the cylinder type gas generator is divided into a combustion chamber and a decompression chamber by the pressure partition. In addition to partitioning, a metal filter is disposed in the decompression chamber as a combustion gas cooling means and a filtration means.

  In the cylinder-type gas generator disclosed in Patent Documents 1 and 2, a partition member as a pressure partition is disposed at a substantially central portion in the axial direction of the housing, and the internal space of the housing is combusted in the axial direction by the partition member. It is divided into a chamber and a decompression chamber. A gas generating agent is accommodated in the combustion chamber, and a cylindrical or columnar filter is disposed in the decompression chamber (see Patent Document 1 described in FIG. 1 or FIG. 6). A cylinder type gas generator corresponds to this, and so on.) Here, in the cylinder type gas generator disclosed in Patent Document 1, a plate-like member in which one or a plurality of communication holes is formed is used as the partition member, and the cylinder type disclosed in Patent Document 2 is used. In the gas generator, a curved member in which a plurality of communication holes are formed is used as a partition member.

  On the other hand, in the cylinder-type gas generator disclosed in Patent Document 3, a cylindrical partition member disposed at a substantially central portion inside the housing is used as a pressure partition as a partition member, and the cylindrical partition member A space inside the housing is partitioned into a combustion chamber and a pressure chamber in the radial direction. The cylindrical member is provided with a plurality of communication holes. A gas generating agent is accommodated in the combustion chamber located inside the cylindrical member, and a cylindrical filter is accommodated in the decompression chamber located outside the cylindrical member.

  Here, in the cylinder type gas generators disclosed in Patent Documents 1 to 3, only one pressure partition provided for reducing the pressure of the combustion gas is provided in the flow direction of the combustion gas. Therefore, in order to ensure a sufficient pressure difference between the combustion chamber and the decompression chamber by this pressure partition, it is inevitably necessary to ensure a large volume of the decompression chamber, and as a result, the cylinder type gas generator It will increase in size. In addition, in order to ensure a sufficient pressure difference between the combustion chamber and the decompression chamber, it is necessary to considerably increase the pressure resistance of the pressure partition wall, and the partition member is made thicker or the partition member material is more mechanical. It becomes necessary to use a material with high mechanical strength, which causes a problem that the manufacturing cost increases.

  In the cylinder type gas generator disclosed in Patent Documents 1 and 2, the gas generating agent and the filter are disposed adjacent to each other with the pressure partition interposed therebetween, so that the high-temperature and high-pressure combustion gas is sufficiently reduced in pressure. In this state, the filter is directly supplied to the filter, and there is a concern that the filter may be damaged. Further, in the cylinder type gas generator disclosed in Patent Document 1 (particularly, the cylinder type gas generator shown in FIG. 1), the combustion gas is locally supplied to the filter. There are problems that cannot be done. Furthermore, in the cylinder type gas generator disclosed in Patent Document 3, a relatively high temperature and high pressure combustion gas is blown at the axial end of the cylindrical filter on the combustion chamber side. There is also concern about filter breakage.

  Accordingly, the present invention has been made to solve the above-described problems, and provides a gas generator that can be configured relatively simply and compactly to obtain desired combustion characteristics. With the goal.

  A gas generator according to the present invention includes a housing, a combustion chamber, a decompression chamber, a partition member, ignition means, and a filter. The housing includes a gas outlet and is formed of a long cylindrical member that is closed at both axial ends. The combustion chamber is located inside the housing, and combustion gas is generated in the combustion chamber by burning the gas generating agent. The decompression chamber is located inside the housing, and in the decompression chamber, the pressure of the combustion gas that has flowed in is reduced as the combustion gas generated in the combustion chamber flows in. Combusted gas is introduced to the gas outlet. The partition member is located inside the housing and partitions a space inside the housing. The ignition means is means for burning the gas generating agent, and the filter is disposed in the decompression chamber. The partition member is disposed coaxially with the housing to thereby divide the decompression chamber into an inner decompression chamber and an outer decompression chamber in the radial direction, and one axial end of the tubular portion And an extending portion that divides the space inside the housing into the combustion chamber and the decompression chamber by being continuously extended radially outward. A first communication hole that communicates the combustion chamber and the inner decompression chamber is provided at an axial end located on the side where the extending portion of the cylindrical portion is provided, and the cylindrical portion Is provided with a second communication hole for communicating the inner decompression chamber and the outer decompression chamber. The gas generating agent is accommodated only in the combustion chamber, and the gas outlet is provided only on the peripheral wall of the housing in a portion defining the outer decompression chamber. The second communication hole has at least one opening surface covered with the filter. The extending portion serves as a pressure partition that creates a pressure difference between the combustion chamber and the outer decompression chamber in a state where the gas generating agent is combusted, and the cylindrical portion is in a state where the gas generating agent is combusted. In this case, a pressure partition wall is formed which creates a pressure difference between the inner decompression chamber and the outer decompression chamber.

  With this configuration, the combustion gas generated in the combustion chamber by the combustion of the gas generating agent is depressurized in two stages in the order of the inner decompression chamber and the outer decompression chamber, and from the gas outlet to the outside of the housing. And will be released. Therefore, it is possible to sufficiently cool and depressurize the combustion gas discharged from the gas outlet, and it becomes easy to obtain desired output characteristics. Further, since the inner decompression chamber and the outer decompression chamber described above can be configured with a very simple configuration in which the partition member having the extending portion is disposed inside the housing, there is a problem that the assembly structure is complicated. Does not occur. Further, since the inner decompression chamber and the outer decompression chamber are partitioned in the radial direction, the gas generator itself does not increase in size. Therefore, it is possible to provide a gas generator that can be configured in a relatively simple and compact configuration for obtaining desired combustion characteristics.

  In the gas generator according to the present invention, the filter preferably has a hollow cylindrical shape, in which case the hollow cylindrical filter is disposed in the outer decompression chamber. It is preferable.

  With this configuration, the combustion gas that has been decompressed and cooled in the inner decompression chamber is blown onto the filter, so that the risk of the filter being damaged is reduced and the required volume of the filter Will be small.

  In the gas generator according to the present invention, it is preferable that the outer peripheral surface of the filter is located at a distance from the inner peripheral surface of the housing facing the outer peripheral surface, thereby the filter and the housing. A space is preferably formed between the two. Moreover, in the gas generator based on the said invention, one axial direction end surface of the said filter is located apart from the surface of the said extension part of the said division member facing the said axial direction end surface. It is preferable that a space is formed between the filter and the extended portion of the partition member. In the gas generator according to the present invention, the other axial end face of the filter is preferably located at a distance from the inner face of the housing facing the axial end face. A space is preferably formed between the filter and the inner surface of the housing.

  By comprising in this way, since the flow of the combustion gas which passes through the filter can be made more uniform in the filter, the filter can be used efficiently. In addition, since the combustion gas after passing through the filter is released from the gas outlet through the space, the combustion gas is more uniformly and stably released from the gas outlet.

  In the gas generator based on the said invention, it is preferable that the said filter is comprised with the metal wire wound around the said cylindrical part.

  In this way, by configuring the filter by winding the metal wire around the cylindrical portion of the partition member, the deformation of the filter toward the radially outer side is suppressed, so that the filter is deformed and the gas It is possible to prevent the occurrence of problems such as clogging of the jet nozzle. In addition, since the filter can be assembled to the partition member in advance before fixing the partition member to the housing, the assembly work can be greatly facilitated and a gas generator can be manufactured at low cost. become.

  In the gas generator according to the present invention, the filter preferably has a hollow cylindrical shape, in which case the hollow cylindrical filter is disposed in the inner decompression chamber. Also good.

  Even in such a configuration, a gas generator that can be configured relatively simply and compactly to obtain desired combustion characteristics can be obtained.

  In the gas generator according to the present invention, it is preferable that a plurality of the second communication holes are equally provided in the cylindrical portion of the portion covered with the filter.

  By configuring in this way, it becomes possible to prevent the combustion gas from flowing locally in the filter, so that the flow of the combustion gas passing through the filter can be made more uniform in the filter. Thus, the filter can be used efficiently.

  In the gas generator according to the present invention, when the opening area of the first communication hole is S1, the opening area of the second communication hole is S2, and the opening area of the gas outlet is S3, S1, S2 and S3 may satisfy the relationship of S1 <S2 and S1 <S3. In this case, S1, S2, and S3 may satisfy the relationship of S1 <S2 <S3.

  In the gas generator according to the present invention, when the opening area of the first communication hole is S1, the opening area of the second communication hole is S2, and the opening area of the gas outlet is S3, S1, S2 and S3 may satisfy the relationship of S2 <S1 and S2 <S3.

  In the gas generator according to the present invention, the partition member may be press-fitted and fixed to the housing, or may be caulked and fixed to the housing.

  With this configuration, the partition member can be assembled to the housing very easily.

  ADVANTAGE OF THE INVENTION According to this invention, it can be set as the gas generator which can be comprised relatively simply and compactly for the structure for obtaining a desired combustion characteristic.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the embodiment described below, a cylinder type gas generator suitably incorporated in the side airbag device will be described as an example.

(Embodiment 1)
1A and 1B are diagrams showing an external structure of a cylinder type gas generator according to Embodiment 1 of the present invention. FIG. 1A is a front view and FIG. 1B is a right side view. FIG. 2 is a diagram showing the internal structure of the cylinder type gas generator in the present embodiment, and FIG. 2 (A) is the IIA-IIA line shown in FIG. 1 (A) and FIG. 1 (B). 2B is a schematic cross-sectional view taken along line IIB-IIB shown in FIG. 2A, and FIG. 2C is a IIC-IIC line shown in FIG. 2A. It is a schematic cross section along the line. First, with reference to these FIG. 1 and FIG. 2, the structure of the cylinder type gas generator in this Embodiment is explained in full detail.

  As shown in FIGS. 1 and 2, the cylinder type gas generator 1 </ b> A in the present embodiment has a long and substantially cylindrical outer shape, and has a housing 10 as an outer shell member. The housing 10 includes a cylindrical member 11, a closing member 14 and a holder 20. The cylindrical member 11 is a long cylindrical member having openings at both ends in the axial direction. The closing member 14 is made of a disk-shaped member having a predetermined thickness, and closes one opening in the axial direction of the cylindrical member 11. The closing member 14 is provided with a recess 14b for fixing a partition member 40 described later. Further, the closing member 14 has a groove 14a for caulking and fixing, which will be described later, on its peripheral surface. The caulking fixing groove 14 a is formed in an annular shape on the peripheral surface of the closing member 14 so as to extend along the circumferential direction. The holder 20 is formed of a cylindrical member having a hollow portion 22 extending along the same direction as the axial direction of the cylindrical member 11, and closes the other opening in the axial direction of the cylindrical member 11. The holder 20 has a groove 21 for caulking and fixing described later at a predetermined position on the outer peripheral surface thereof. The caulking fixing groove 21 is formed in an annular shape on the outer peripheral surface of the holder 20 so as to extend along the circumferential direction.

  The cylindrical member 11, the closing member 14, and the holder 20 are all made of a metal member such as stainless steel, steel, aluminum alloy, stainless alloy, and are connected and fixed by caulking. Specifically, in a state where a part of the closing member 14 is inserted into one opening end of the cylindrical member 11, a portion of the cylindrical member 11 corresponding to the groove 14 a provided on the peripheral surface of the closing member 14. The closure member 14 is caulked and fixed to the cylindrical member 11 by reducing the diameter of the peripheral wall inward in the radial direction and engaging with the groove 14a. In a state where the portion is inserted, the peripheral wall of the cylindrical member 11 corresponding to the groove 21 provided on the outer peripheral surface of the holder 20 is contracted radially inward and engaged with the groove 21. The holder 20 is caulked and fixed to the cylindrical member 11.

  These caulking fixings are caulking fixings called eight-side caulking that uniformly reduce the diameter of the peripheral wall of the cylindrical member 11 radially inward. By performing this caulking, the caulking portions 13 a and 13 b are provided on the peripheral wall of the cylindrical member 11. By using the above-mentioned eight-way caulking, airtightness can be sufficiently ensured without interposing a seal member between two members to be caulked and fixed.

  As shown in FIG. 2A, an ignition chamber 15, a combustion chamber 16, and a decompression chamber 17 are formed in a space inside the cylinder type gas generator 1 A defined by the cylindrical member 11, the closing member 14 and the holder 20. Is provided. The ignition chamber 15, the combustion chamber 16, and the decompression chamber 17 are partitioned by a cushion member 51 and a partition member 40 which will be described later and are housed in the housing 10.

  The ignition chamber 15 is mainly defined by the cylindrical member 11, the holder 20, and the cushion material 51, and is provided in a portion of the housing 10 near the holder 20 (right portion in the drawing). An igniter (squib) 30 is disposed in the hollow portion 22 of the holder 20, and the resin molding portion 24 is located between the holder 20 and the igniter 30. A bottomed cylindrical cup-shaped member 25 is attached to the end of the holder 20 on the combustion chamber 16 side, and a heat transfer chamber 26 which is a space inside the bottomed cylindrical cup-shaped member 25 is provided in the transfer chamber 26. The explosive (enhancer) 27 is accommodated.

  A concave portion 23 is provided on the outer peripheral surface of the holder 20 (that is, the surface facing the inner peripheral surface of the cylindrical member 11) so as to extend in the circumferential direction. A seal member 28 is accommodated in the concave portion 23. Yes. The seal member 28 is for hermetically sealing a gap generated between the cylindrical member 11 and the holder 20, and thereby the airtightness between the outside of the cylinder type gas generator 1 </ b> A and the ignition chamber 15. Will be secured. The space between the inner peripheral surface of the holder 20 and the igniter 30 is sealed by the resin molding portion 24 as described above, whereby the space between the outside of the cylinder-type gas generator 1A and the ignition chamber 15 is sealed. Airtightness is ensured.

  As the above-described seal member 28, a member having sufficient heat resistance and durability is preferably used. For example, an O-ring made of EPDM resin, which is a kind of ethylene propylene rubber, can be suitably used. The seal member 28 is inserted and attached between these members when the cylindrical member 11 and the holder 20 are caulked and fixed. If a liquid sealing agent is separately applied to the portion where the sealing member 28 is interposed and cured, higher airtightness can be obtained.

  The above-mentioned resin molding part 24 is formed by, for example, insert molding, and the raw material thereof is thermosetting resin represented by epoxy resin, polybutylene terephthalate resin, polyethylene terephthalate resin, polyamide resin (for example, nylon 6). And thermoplastic resins represented by polypropylene sulfide resin, polypropylene oxide resin, and the like.

  The igniter 30 is an ignition device for generating a flame, and includes an ignition unit 31 and a terminal pin 32. The ignition unit 31 includes an igniting agent that ignites during operation and a resistor for burning the igniting agent. The terminal pin 32 is connected to the ignition unit 31 in order to ignite the igniting agent. More specifically, the igniter 30 includes a base portion through which the pair of terminal pins 32 are inserted and held, and a squib cup attached to the base portion, and the tip of the terminal pin 32 inserted into the squib cup. A resistor (bridge wire) is attached so as to connect the squib cups, and an igniting agent is filled in the squib cup so as to surround the resistor or in contact with the resistor. Nichrome wire or the like is generally used as the resistor, and ZPP (zirconium / potassium perchlorate), ZWPP (zirconium / tungsten / potassium perchlorate), lead tricinate, or the like is generally used as the igniting agent. The squib cup is generally made of metal or plastic.

  When a collision is detected, a predetermined amount of current flows through the resistor via the terminal pin 32. When a predetermined amount of current flows through the resistor, Joule heat is generated in the resistor, and the ignition powder starts to burn upon receiving this heat. The high temperature flame generated by the combustion ruptures the squib cup containing the igniting agent. The time from when the current flows through the resistor until the igniter 30 is activated is 3 milliseconds or less when a nichrome wire is used as the resistor.

The explosive charge 27 is ignited by a flame generated by the operation of the igniter 30 and burns to generate hot particles. The charge transfer agent 27 is required to be able to reliably start combustion of a gas generating agent 52 described later. Generally, from the metal powder / oxidant represented by B / KNO ₃ or the like. The composition etc. which become are used. As the explosive charge 27, a powdery one, one molded into a predetermined shape by a binder, or the like is used. Examples of the shape of the transfer charge molded by the binder include various shapes such as a granular shape, a columnar shape, a sheet shape, a spherical shape, a single-hole cylindrical shape, a porous cylindrical shape, and a tablet shape.

  The combustion chamber 16 is defined by the cylindrical member 11, a flange portion 42 of the partition member 40 to be described later, and a cushion material 51, and is provided at a substantially central portion of the housing 10. A gas generating agent 52 and a perforated plate 18 are accommodated in the combustion chamber 16.

  The gas generating agent 52 is ignited by the heat particles generated by the combustion of the charge transfer agent 27 ignited by the igniter 30, and generates gas by burning. The gas generating agent 52 is generally formed as a molded body containing a fuel, an oxidant, and an additive. As the fuel, for example, a triazole derivative, a tetrazole derivative, a guanidine derivative, an azodicarbonamide derivative, a hydrazine derivative, or a combination thereof is used. Specifically, for example, nitroguanidine, guanidine nitrate, cyanoguanidine, 5-aminotetrazole and the like are preferably used. In addition, as the oxidizing agent, for example, nitrate containing a cation selected from alkali metals, alkaline earth metals, transition metals, and ammonia is used. As the nitrate, for example, sodium nitrate, potassium nitrate and the like are preferably used. In addition, examples of the additive include a binder, a slag forming agent, and a combustion adjusting agent. As the binder, for example, organic binders such as metal salts of carboxymethyl cellulose and stearates, and inorganic binders such as synthetic hydroxytalcite and acid clay can be suitably used. As the slag forming agent, silicon nitride, silica, acid clay, etc. can be suitably used. Moreover, as a combustion regulator, a metal oxide, ferrosilicon, activated carbon, graphite, etc. can be used suitably.

  The shape of the molded body of the gas generating agent 52 includes various shapes such as a granular shape, a pellet shape, a cylindrical shape, and a disk shape. In addition, a porous (for example, a single-hole cylindrical shape or a porous cylindrical shape) having a hole inside the molded body is also used. These shapes are preferably appropriately selected according to the specifications of the airbag apparatus in which the cylinder type gas generator 1A is incorporated. For example, the shape in which the gas generation rate changes with time when the gas generating agent 52 is burned. It is preferable to select an optimal shape according to the specification, such as selecting. In addition to the shape of the gas generating agent 52, it is preferable to appropriately select the size and filling amount of the molded body in consideration of the linear combustion rate, the pressure index, etc. of the gas generating agent 52.

  The cushion material 51 that partitions the ignition chamber 15 and the combustion chamber 16 is disposed so as to contact the gas generating agent 52 accommodated in the combustion chamber 16. The cushion material 51 is provided for the purpose of preventing the gas generating agent 52 made of a molded body from being pulverized by vibration or the like, and a ceramic fiber molded body, foamed silicon, or the like is preferably used. The cushion material 51 is opened or divided by combustion of the charge transfer agent 27 during operation, and in some cases burns down.

  A perforated plate 18 provided with a plurality of communication holes 18a is disposed at the end of the combustion chamber 16 on the decompression chamber 17 side. The perforated plate 18 is composed of a curved member whose central portion protrudes toward the holder 20, and rectifies the flow of combustion gas passing through the perforated plate 18 during operation, and also generates a gas generating agent. This is for preventing 52 from passing through the perforated plate 18 and further moving to the decompression chamber 17 in an unburned state. Therefore, the communication holes 18 a provided in the porous plate 18 are all formed smaller than the outer shape of the gas generating agent 52.

  A partition member 40 is accommodated in the decompression chamber 17. The partition member 40 is continuously extended radially outward from the cylindrical portion 41 disposed coaxially with the cylindrical member 11 and the axial end of the cylindrical portion 41 on the combustion chamber 16 side. And a flange portion 42 as an extending portion. The decompression chamber 17 is defined by the cylindrical member 11, the closing member 14, and the flange portion 42 of the partition member 40, and is provided in a portion of the housing 10 near the closing member 14 (the left portion in the drawing).

  The partition member 40 has an axial end of the cylindrical portion 41 on the side where the flange portion 42 is not provided is inserted into a recess 14 b provided in the closing member 14 and is press-fitted and fixed. The end portion is fixed to the housing 10 by being press-fitted and fixed to the cylindrical member 11. Of the peripheral wall of the cylindrical member 11 adjacent to the flange portion 42, a caulking portion 13c is provided on the portion on the decompression chamber 17 side by reducing the diameter of the portion toward the radially inner side. In the caulking portion 13c, the above-described eight-side caulking is used, and the contact portion between the flange portion 42 of the partition member 40 and the cylindrical member 11 is thereby hermetically sealed.

  The decompression chamber 17 is partitioned into two chambers in the radial direction by the cylindrical portion 41 of the partition member 40. Specifically, the decompression chamber 17 is partitioned into an inner decompression chamber 17 a located inside the cylindrical portion 41 and an outer decompression chamber 17 b located outside the tubular portion 41. In addition, a first communication hole 43 that communicates the combustion chamber 16 and the inner decompression chamber 17a is provided at the axial end of the cylindrical portion 41 on the side where the flange portion 42 is provided. The tubular portion 41 is provided with a second communication hole 44 that communicates the inner decompression chamber 17a and the outer decompression chamber 17b. Among these, a plurality of second communication holes 44 are provided along the circumferential direction and the axial direction of the tubular portion 41. The tubular portion 41 and the flange portion 42 described above each function as a pressure partition that causes a pressure difference between the chambers during operation, and have a predetermined proof stress (mechanical strength). It is composed of. Specifically, the partition member 40 is made of a metal member such as stainless steel, steel, an aluminum alloy, or a stainless alloy.

  A filter 60 is accommodated in the outer decompression chamber 17b. The filter 60 is formed of a cylindrical member having a hollow opening extending in the same direction as the axial direction of the cylindrical member 11, and is provided so as to cover the second communication hole 44 provided in the cylindrical portion 41 described above. Yes. As the filter 60, for example, a wire or net made of a metal such as stainless steel or steel is wound in the circumferential direction, or pressed by pressing, or the like is used. When the filter 60 is made of a mesh material, a knitted wire mesh, a plain weave wire mesh, an assembly of crimped metal wires, or the like can be used. When the gas generated in the combustion chamber 16 passes through the filter 60, the filter 60 functions as a cooling means that cools the gas by taking away the high-temperature heat of the gas, and the slag contained in the gas. It also functions as a filtering means for removing water.

  The outer peripheral surface of the filter 60 accommodated and disposed in the outer decompression chamber 17b is disposed at a predetermined distance from the inner peripheral surface of the peripheral wall of the cylindrical member 11 facing the outer peripheral surface. Further, the axial end surface of the filter 60 on the combustion chamber 16 side is disposed at a predetermined distance from the surface of the flange portion 42 of the partition member 40 facing the axial end surface. Furthermore, the axial end surface of the filter 60 on the closing member 14 side is disposed with a predetermined distance from the surface on the inner surface side of the closing member 14 facing the axial end surface. Thus, the outer peripheral surface and the axial end surface of the filter 60 are not in contact with the housing 10 and the flange portion 42 of the partition member 40, and a space is formed between them.

  A gas outlet 12 is provided on the peripheral wall of the cylindrical member 11 that defines the outer decompression chamber 17b. The gas outlet 12 is a hole for releasing the gas generated inside the cylinder type gas generator 1 </ b> A to the outside, and a plurality of gas outlets 12 are provided along the circumferential direction and the axial direction of the cylindrical member 11. A seal member 19 is affixed to the inner peripheral surface of the cylindrical member 11 so as to close the gas ejection port 12. The seal member 19 is a member for ensuring airtightness between the space outside the housing 10 and the outer decompression chamber 17b when not in operation. Preferably, an aluminum foil or the like with an adhesive member applied on one side is used. Used.

  A female connector (not shown) is attached to the end of the cylinder type gas generator 1A where the holder 20 is disposed. This female connector is a part to which a male connector of a harness that transmits a signal from a collision detection sensor provided separately from the cylinder type gas generator 1A is connected. A shorting clip (not shown) is attached to the female connector as necessary. The shorting clip is attached to prevent the cylinder type gas generator 1A from malfunctioning due to electrostatic discharge or the like during the transportation of the cylinder type gas generator 1A. In the stage, the male connector of the harness is inserted into the female connector, so that the contact with the terminal pin 32 is released.

  Next, the operation | movement at the time of the action | operation of the cylinder type gas generator 1A demonstrated above is demonstrated. When a vehicle equipped with an airbag device incorporating the cylinder-type gas generator 1A according to the present embodiment collides, the collision is detected by a collision detection means provided separately in the vehicle, and ignition is performed based on this. The device 30 is activated. When the igniter 30 is activated, the pressure in the igniter 31 increases due to combustion of the igniting agent, whereby the igniter 31 is ruptured and the flame flows out of the igniter 31. The explosive charge 27 accommodated in the ignition chamber 15 is ignited and burned by the flame generated by the operation of the igniter 30, and generates a large amount of heat particles. Due to the combustion of the charge transfer agent 27, the pressure in the transfer chamber 26 rises, whereby the cup-shaped member 25 is ruptured, and the above-described hot particles reach the combustion chamber 16.

  The hot particles that reach the combustion chamber 16 burn the cushion material 51 to open or divide it, and the gas generating agent 52 is ignited and burned in the combustion chamber 16 to generate a large amount of combustion gas. The generated combustion gas passes through a communication hole 18a provided in the porous plate 18, is rectified, and is a space in which the gas generating agent in the combustion chamber 16 is not accommodated (a portion sandwiched between the porous plate 18 and the decompression chamber 17). To the combustion chamber). Then, the combustion gas flows into the inner decompression chamber 17a via the first communication hole 43 provided at the axial end of the cylindrical portion 41 of the partition member 40 on the combustion chamber 16 side, and enters the inner decompression chamber 17a. Flow in the axial direction. At that time, the combustion gas is depressurized more than the pressure in the combustion chamber 16, and the temperature is also lowered with the depressurization.

  The combustion gas introduced into the inner decompression chamber 17a and decompressed flows into the outer decompression chamber 17b through the second communication hole 44 provided in the tubular portion 41 of the partition member 40. At that time, the combustion gas is cooled by the filter 60 disposed so as to cover the second communication hole 44, and the slag contained in the combustion gas is removed. Further, at that time, the combustion gas is depressurized more than the pressure in the inner decompression chamber 17a, and the temperature further decreases with the depressurization. Thereafter, the combustion gas reduced to a predetermined pressure and cooled to a predetermined temperature ruptures the seal member 19 closing the gas outlet 12 and is discharged from the gas outlet 12 to the outside of the housing 10. The gas released from the gas outlet 12 is guided into the airbag to inflate and deploy the airbag.

  As described above, by using the cylinder type gas generator 1A in the present embodiment, the combustion gas generated in the combustion chamber 16 by the combustion of the gas generating agent 52 is converted into the inner decompression chamber 17a and the outer decompression chamber 17a. The pressure is reduced in two stages in the order of the chamber 17 b and is discharged from the gas outlet 12 to the outside of the housing 10. Therefore, it is possible to sufficiently cool and depressurize the combustion gas discharged from the gas outlet 12, and it becomes easy to obtain desired output characteristics. Moreover, since the inner decompression chamber 17a and the outer decompression chamber 17b described above can be configured with a very simple configuration in which the partition member 40 having the flange portion 42 is disposed inside the housing 10, an assembly structure is provided. There is no problem of complication. Further, since the inner decompression chamber 17a and the outer decompression chamber 17b are partitioned in the radial direction, the gas generator itself does not increase in size. Therefore, it is possible to provide a gas generator that can be configured in a relatively simple and compact configuration for obtaining desired combustion characteristics.

  In addition, by using the cylinder type gas generator 1A in the present embodiment, the combustion gas that has been decompressed and cooled in the inner decompression chamber 17a is blown to the filter 60, and therefore the filter 60 is damaged. The risk is reduced, and the required volume of the filter 60 can be reduced. Moreover, since the flow of the combustion gas passing through the filter 60 can be made more uniform in the filter 60, the filter 60 can be used efficiently. Further, since the combustion gas after passing through the filter 60 is discharged from the gas outlet 12 through the space of the outer decompression chamber 17b where the filter 60 is not located, the gas injection can be performed more uniformly and stably. Combustion gas is released from the outlet 12. Therefore, the filter 60 can be prevented from being damaged, and the filter 60 can be efficiently used. Therefore, the filter 60 can be reduced in size, and a high performance, small and light gas generator can be obtained.

  Further, if the filter 60 has a configuration in which a metal wire is wound around the tubular portion 41 of the partition member 40, the deformation of the filter 60 toward the radially outer side is suppressed. Generation | occurrence | production of the malfunction that the filter 60 deform | transforms and the gas jet nozzle 12 causes clogging can be prevented now. In addition, by adopting the above configuration, the filter 60 can be assembled to the partition member 40 in advance before fixing the partition member 40 to the housing 10, so that the assembly work is greatly facilitated. A gas generator can be manufactured at low cost.

As shown in FIG. 2 (B), in the cylinder type gas generator 1A according to the present embodiment, the first communication hole 43 is configured as a single hole, and the opening area S1 is defined as the first area. the diameter of the communicating hole 43 when the phi _1, represented by _{S1 = π × (φ 1/} 2) 2. Further, as shown in FIG. 2C, in the cylinder type gas generator 1A in the present embodiment, the second communication hole 44 is constituted by a plurality of holes, and the sum S2 of the opening areas thereof is the diameter per one of the second communication hole 44 and phi _2, when the number is n, is represented by S2 = n × π × (φ 2/2) 2. Further, as shown in FIG. 2C, in the cylinder type gas generator 1A in the present embodiment, the gas outlet 12 is composed of a plurality of holes, and the sum S3 of the opening areas is diameter per one gas injection port 12 and phi _3, when the number is m, is represented by S3 = m × π × (φ 3/2) 2. In FIG. 2C, the illustration of the seal member 19 that is stuck to close the gas outlet 12 is omitted.

  Here, when these S1, S2, and S3 satisfy the relationship of S1 <S2 and S1 <S3, the flange portion 42 of the partition member 40 mainly has an aperture stop plate for reducing the pressure of the combustion gas (that is, It will function as a pressure partition). In that case, S1 / S2 and S1 / S3 are preferably adjusted to be in the range of 0.25 to 1, respectively. When configured in this manner, the cylindrical member 11 at the portion defining the outer decompression chamber 17b and the cylindrical portion 41 of the partition member 40 can be thinned to some extent. Further, when these S1, S2, and S3 are configured to satisfy the relationship of S1 <S2 <S3, both the flange portion 42 and the cylindrical portion 41 of the partition member 40 are for reducing the combustion gas. It functions as an aperture diaphragm (ie, a pressure partition), and the pressure applied to the housing and the partition member 40 can be dispersed.

  On the other hand, when these S1, S2, and S3 satisfy the relationship of S2 <S1 and S2 <S3, the cylindrical portion 41 of the partition member 40 mainly has an aperture stop plate for reducing the pressure of the combustion gas (that is, It will function as a pressure partition). In that case, S2 / S1 and S2 / S3 are preferably adjusted to be in the range of 0.25 to 1, respectively. When configured in this manner, the cylindrical member 11 at the portion defining the outer decompression chamber 17b and the flange portion 42 of the partition member 40 can be thinned to some extent.

(Embodiment 2)
FIG. 3 is a schematic cross-sectional view showing the internal structure of the cylinder-type gas generator according to Embodiment 2 of the present invention. In addition, the same code | symbol is attached | subjected in the figure about the part similar to the cylinder type gas generator in above-mentioned Embodiment 1, and the description is not repeated here.

  As shown in FIG. 3, the cylinder type gas generator 1 </ b> B in the present embodiment is a cylinder type gas generator in the above-described first embodiment in the configuration of the ignition chamber 15 and the combustion chamber 16 configured in the housing 10. Slightly different from 1A. Specifically, the ignition chamber 15 is defined by the cup-shaped member 25 and the holder 20, and the combustion chamber 16 is defined by the cylindrical member 11, the flange portion 42 of the partition member 40, and the cup-shaped member 25. . In the ignition chamber 15, the ignition part 31 and the charge transfer agent 27 of the igniter 30 are mainly accommodated, and in the combustion chamber 16, the gas generating agent 52, the porous plate 18 and the cushion material are mainly accommodated. Yes. The decompression chamber 17 is defined by the cylindrical member 11, the closing member 14, and the flange portion 42 of the partition member 40, and is divided into the inner decompression chamber 17 a and the outer decompression chamber radially defined by the tubular portion 41 of the partition member 40. 17b. A hollow cylindrical filter 60 is accommodated in the outer decompression chamber 17b. The cup-shaped member 25 is provided with a plurality of openings 25 a, and the cup-shaped member 25 is fixed to the cylindrical member 11 by caulking portions 13 d provided on the cylindrical member 11.

  In the cylinder type gas generator 1 </ b> B according to the present embodiment, the gas generating agent 52, the porous plate 18, and the cushion material 51 accommodated in the combustion chamber 16 are sealed with a sealing member 70. The sealing member 70 has a cup part 71 and a cap part 72, and the opening of the cup part 71 is a cap part in a state where the gas generating agent 52, the porous plate 18 and the cushion material 51 are accommodated in the cup part 71. 72 is obstructed. The sealing member 70 is made of a thin plate (foil) of a metal material such as copper, aluminum, copper alloy, or aluminum alloy. Brazing, adhesion, or the like is used for joining the cup portion 71 and the cap portion 72. It is used.

  In the cylinder type gas generator 1 </ b> B in the present embodiment, the transfer charge 27 accommodated in the ignition chamber 15 is sealed by the sealing member 80. The sealing member 80 has a cup part 81 and a cap part 82, and the opening of the cup part 81 is closed by the cap part 82 in a state where the transfer charge 27 is accommodated in the cup part 81. The sealing member 80 is made of a thin plate (foil) of a metal material such as copper, aluminum, copper alloy, and aluminum alloy. Brazing, adhesion, or the like is used for joining the cup portion 81 and the cap portion 82. It is used.

  With this configuration, when the cylinder type gas generator 1B is assembled, the gas generating agent 52 and the transfer agent 27, which are complicated to handle, can be sealed in the packaging in advance. The assembly can be performed only by assembling these formed members into the housing. Therefore, it can be set as the cylinder type gas generator with which the assembly work was facilitated. In addition, since the gas generating agent 52 and the charge transfer agent 27 are sealed by the sealing members 70 and 80, respectively, between each member (cylindrical member 11, closing member 14 and holder 20) constituting the housing 10, etc. A sealing process using a sealing member or a sealing agent is not necessary, and the apparatus configuration is greatly simplified. Therefore, the manufacturing cost can be greatly reduced, and the assembling property can be greatly improved.

  4 to 8 are enlarged cross-sectional views of the main part showing the internal structure of the cylinder type gas generator according to the first to fifth modifications of the present embodiment. Next, the structure of the cylinder type gas generator according to the first to fifth modifications of the present embodiment will be described with reference to FIGS.

  In the cylinder type gas generator 1C according to the first modification shown in FIG. 4, the axial end faces of the hollow cylindrical filter 60 accommodated in the outer decompression chamber 17b are respectively flange portions 42 of the partition members 40. And the inner surface of the closing member 14 are in contact with each other. And the 2nd communicating hole 44 is provided in alignment over the substantially whole area of the axial direction of the cylindrical part 41 of the division member 40. As shown in FIG. Even in such a configuration, the effects as described in the first and second embodiments can be obtained.

  In the cylinder type gas generator 1D according to the second modification shown in FIG. 5, the bent portion 42a extends continuously from the outer peripheral end portion of the flange portion 42 of the partition member 40, and the cylindrical member 11. When the partition member 40 is assembled and fixed, the outer peripheral surface of the bent portion 42a is configured to be in pressure contact with the inner peripheral surface of the cylindrical member 11. When configured in this manner, the effects as described in the first and second embodiments can be obtained, and the partition member 40 and the cylinder can be obtained by the elastic biasing force toward the outside of the bent portion 42a. Since the pressure contact with the cylindrical member 11 is realized, it is not necessary to fix the cylindrical member 11 and the flange portion of the partition member 40 by caulking in the first and second embodiments described above, and further assembly. The work can be facilitated.

  In the cylinder type gas generator 1E according to the third modification shown in FIG. 6, the extending portion that is continuously extended from the axial end surface on the combustion chamber 16 side of the tubular portion 41 of the partition member 40 is provided. The tapered portion 45 extends from the tubular portion 41 in an inclined manner toward the radially outer side. In such a configuration, the combustion chamber 16 reaches the inside of the tapered portion 45 of the partition member 40, and also in this case, the combustion chamber 16 and the outer decompression chamber 17 b are extended from the partition member 40. It is divided by the taper part 45 as a part. Here, the tapered portion 45 of the partition member 40 is press-fitted and fixed to the cylindrical member 11. When configured in this manner, the effects as described in the first and second embodiments can be obtained, and the partition member 40 and the cylindrical member can be obtained by the elastic biasing force toward the outside of the tapered portion 45. 11 is realized, it is not necessary to fix the cylindrical member 11 and the flange portion of the partition member 40 by caulking in the first and second embodiments described above. Simplification can be achieved.

  In the cylinder type gas generator 1F according to the fourth modification shown in FIG. 7, a hollow cylindrical filter 60 is disposed in the inner decompression chamber 17a. Specifically, by adopting a configuration in which the filter 60 is press-fitted into the tubular portion 41 of the partition member 40, the second communication hole 44 provided in the tubular portion 41 is covered by the press-fitted filter 60. It is configured. Even in such a configuration, the effects as described in the first and second embodiments can be obtained.

  In the cylinder type gas generator 1G according to the fifth modification shown in FIG. 8, a bottomed cylindrical member having a bottom portion 11a is used as the cylindrical member 11 and a bottomed tube having a bottom portion 46 as the partition member 40 is used. A shaped member is used. Then, the assembly of the partition member 40 to the cylindrical member 11 is realized by the contact between the bottom portion 11 a of the cylindrical member 11 and the bottom portion 46 of the partition member 40. Even in such a configuration, the effects as described in the first and second embodiments can be obtained.

  In Embodiments 1 and 2 described above and modifications thereof, the case where the present invention is applied to a cylinder type gas generator incorporated in a side airbag device is described as an example. The object is not limited to this, but a so-called T-shaped gas generator having a long output portion similar to a cylinder-type gas generator incorporated in an airbag device for a passenger seat or a cylinder-type gas generator The application is also possible.

  As described above, the above-described embodiments and modifications thereof disclosed herein are illustrative in all respects and are not restrictive. The technical scope of the present invention is defined by the terms of the claims, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

It is a top view which shows the external appearance structure of the cylinder type gas generator in Embodiment 1 of this invention. It is a schematic cross section which shows the internal structure of the cylinder type gas generator in Embodiment 1 of this invention. It is a schematic cross section which shows the internal structure of the cylinder type gas generator in Embodiment 2 of this invention. It is a principal part expanded sectional view which shows the internal structure of the cylinder type gas generator which concerns on the 1st modification of Embodiment 2 of this invention. It is a principal part expanded sectional view which shows the internal structure of the cylinder type gas generator which concerns on the 2nd modification of Embodiment 2 of this invention. It is a principal part expanded sectional view which shows the internal structure of the cylinder type gas generator which concerns on the 3rd modification of Embodiment 2 of this invention. It is a principal part expanded sectional view which shows the internal structure of the cylinder type gas generator which concerns on the 4th modification of Embodiment 2 of this invention. It is a principal part expanded sectional view which shows the internal structure of the cylinder type gas generator which concerns on the 5th modification of Embodiment 2 of this invention.

Explanation of symbols

  1A to 1G Cylinder type gas generator, 10 housing, 11 cylindrical member, 11a bottom, 12 gas outlet, 13a to 13d, caulking part, 14 closing member, 14a groove, 14b recess, 15 ignition chamber, 16 combustion chamber, 17 Decompression chamber, 17a Inner decompression chamber, 17b Outer decompression chamber, 18 Perforated plate, 18a Communication hole, 19 Seal member, 20 Holder, 21 Groove, 22 Hollow portion, 23 Recessed portion, 24 Resin molded portion, 25 Cup-shaped member, 25a Opening Part, 26 heat transfer chamber, 27 transfer powder, 28 seal member, 30 igniter, 31 ignition part, 32 terminal pin, 40 partition member, 41 cylindrical part, 42 flange part, 42a bent part, 43 first communication hole, 44 2nd communication hole, 45 taper part, 46 bottom part, 51 cushioning material, 52 gas generating agent, 60 filter, 70 sealing member 71 cup portion 72 cap portion 80 sealing member, 81 cup portion 82 cap portion.

Claims (12)

A long cylindrical housing that includes a gas outlet and is closed at both axial ends;
A combustion chamber that is located inside the housing and in which combustion gas is generated by burning the gas generating agent;
A decompression chamber that is located inside the housing and depressurizes the pressure of the combustion gas that flows in by the combustion gas generated in the combustion chamber flowing in, and that guides the decompressed combustion gas to the gas outlet;
A partition member located inside the housing and defining a space inside the housing;
Ignition means for burning the gas generating agent;
A filter disposed in the decompression chamber,
The partition member is disposed coaxially with the housing to thereby divide the decompression chamber into an inner decompression chamber and an outer decompression chamber in the radial direction, and one axial end of the tubular portion Including an extending portion that continuously extends from the outside in a radial direction to partition the space inside the housing into the combustion chamber and the decompression chamber,
A first communication hole that communicates the combustion chamber and the inner decompression chamber is provided at an axial end located on the side where the extending portion of the cylindrical portion is provided,
The cylindrical portion is provided with a second communication hole that communicates the inner decompression chamber and the outer decompression chamber,
The gas generating agent is accommodated only in the combustion chamber,
The gas ejection port is provided only on the peripheral wall of the housing in a portion defining the outer decompression chamber,
The second communication hole has at least one opening surface thereof covered by the filter,
The extending portion serves as a pressure partition that creates a pressure difference between the combustion chamber and the outer decompression chamber in a state where the gas generating agent is burned,
The gas generator, wherein the cylindrical portion serves as a pressure partition wall that generates a pressure difference between the inner decompression chamber and the outer decompression chamber in a state where the gas generating agent is combusted.   The gas generator according to claim 1, wherein the filter has a hollow cylindrical shape and is disposed in the outer decompression chamber.   The outer peripheral surface of the filter is located at a distance from the inner peripheral surface of the housing facing the outer peripheral surface, and thereby a space is formed between the filter and the housing. Gas generator. One axial end surface of the filter is located at a distance from the surface of the extending portion of the partition member facing the axial end surface, whereby the filter and the extending portion of the partition member are separated from each other. A space is formed between
The other axial end surface of the filter is located at a distance from the inner surface of the housing facing the axial end surface, thereby forming a space between the filter and the inner surface of the housing. Item 4. The gas generator according to Item 2 or 3.   The gas generator according to any one of claims 2 to 4, wherein the filter is made of a metal wire wound around the cylindrical portion.   The gas generator according to claim 1, wherein the filter has a hollow cylindrical shape and is disposed in the inner decompression chamber.   The gas generator according to any one of claims 1 to 6, wherein a plurality of the second communication holes are equally provided in the cylindrical portion of the portion covered with the filter.   When the opening area of the first communication hole is S1, the opening area of the second communication hole is S2, and the opening area of the gas outlet is S3, these S1, S2, and S3 are S1 <S2 and S1 < The gas generator according to any one of claims 1 to 7, wherein the relationship of S3 is satisfied.   The gas generator according to claim 8, wherein the S1, S2, and S3 satisfy a relationship of S1 <S2 <S3.   When the opening area of the first communication hole is S1, the opening area of the second communication hole is S2, and the opening area of the gas outlet is S3, these S1, S2 and S3 are S2 <S1 and S2 < The gas generator according to any one of claims 1 to 7, wherein the relationship of S3 is satisfied.   The gas generator according to any one of claims 1 to 10, wherein the partition member is press-fitted and fixed to the housing.   The gas generator according to claim 1, wherein the partition member is fixed by caulking to the housing.

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