JP2020152224A - Gas generator - Google Patents

Abstract

To provide a gas generator having a dual structure of a simple constitution, from which desired gas output can be stably obtained.SOLUTION: A gas generator 1A comprises a partitioning part 44 for partitioning a space inside a filter 70 being an internal part of a housing into a first combustion chamber S1 and a second combustion chamber S2. The partitioning part 44 includes a partition wall member 45 and a cover member 46. The partitioning part 44 is fixed to a bottom plate part 11 of the housing via a holder 41, by press-fitting the partition wall member 45 to the holder 41 holding a second igniter 42. The cover member 46 has a first covering part 46a covering an opening 45c of the partition wall member 45, and a second covering part 46b covering a cylindrical part 45b of the partition wall member 45. On the second covering part 46b, a fragile part 46b1 is disposed. During operation of the second igniter 42, the cover member 46 moves toward a top plate part 21 side, and then, gas generated in the second combustion chamber S2 is introduced to the first combustion chamber by cleaving the fragile part 46b1.SELECTED DRAWING: Figure 1

Description

The present invention relates to a gas generator incorporated in an occupant protection device that protects an occupant in the event of a collision with a vehicle or the like, and more particularly to a gas generator incorporated in an airbag device installed in an automobile or the like.

Conventionally, from the viewpoint of protecting occupants of automobiles and the like, airbag devices, which are occupant protection devices, have become widespread. The airbag device is equipped for the purpose of protecting the occupant from the impact generated at the time of a vehicle collision. By instantly expanding and deploying the airbag at the time of a vehicle collision, the airbag acts as a cushion for the occupant. It catches the body.

The gas generator is incorporated in this airbag device, and when a vehicle collides, the igniter is ignited by energization from the control unit, and the flame generated in the igniter burns the gas generator to instantly generate a large amount of gas. , A device that inflates and deploys the airbag.

There are various types of gas generators, but as a gas generator that is particularly preferably incorporated into a driver's side airbag device, a passenger's side airbag device, etc., a short abbreviation with a relatively large outer diameter. There is a columnar disc type gas generator. This disc-type gas generator also has various structures, and one of them is a dual-structure disc-type gas generator.

The dual structure disc type gas generator divides the combustion chamber formed inside the tubular filter installed inside the housing into two chambers, and fills each of the two chambers with a gas generator, and further. Two igniters are provided corresponding to these two chambers, and usually one igniter is configured to operate later than the other igniter. Compared to a single-structured disc-type gas generator equipped with only a single combustion chamber and a single igniter, this dual-structured disc-type gas generator can maintain the desired gas output for a long period of time. It is possible to obtain more suitable gas output characteristics by deploying the bag.

In the dual structure disc type gas generator, a pressure bulkhead is provided inside the housing to divide the combustion chamber into two chambers. This pressure bulkhead is generally composed of a cup-shaped member, and in that case, the space outside the pressure bulkhead is the first gas generating agent in which combustion is started first. It is defined as a combustion chamber, and the space inside the pressure bulkhead is defined as a second combustion chamber in which a second gas generating agent, which starts combustion with a delay, is housed.

Here, the tubular side wall portion of the cup-shaped pressure partition is provided with a gas passage hole for allowing the gas generated in the second combustion chamber to be ejected to the outside through the first combustion chamber. However, the gas passage hole affects the second gas generating agent contained in the second combustion chamber in which combustion has not yet started when the first gas generating agent is burned in the first combustion chamber. It needs to be sealed so that it does not occur.

Therefore, for example, in a dual-structured disk-type gas generator, the pressure partition is provided with a cup member including a closed end and a cup-shaped fragile cover member assembled to the cup member so as to cover the closed end. By dividing it into two members and providing a gas passage hole in the peripheral wall of the cup member, the gas passage hole is blocked by the cover member during combustion of the first gas generator, and the second gas generator is burned. In the above, the pressure generated by the combustion of the second gas generator causes the cover member of the portion covering the gas passage hole to be cleaved so that the second combustion chamber and the first combustion chamber communicate with each other. Will be done.

As a document in which a disc-type gas generator having a dual structure having such a configuration is disclosed, for example, Japanese Patent Application Laid-Open No. 2007-1310777 (Patent Document 1) can be mentioned.

Japanese Unexamined Patent Publication No. 2007-13107

Here, from the viewpoint of facilitating the assembly work by simplifying the assembly structure and thereby reducing the manufacturing cost, it is preferable to fix the pressure bulkhead described above to the housing by using so-called press fitting. In this regard, although the detailed description thereof is not given in Patent Document 1, it is decided that a substantially cylindrical igniter collar for holding the igniter is fixed to the housing, and the cup described above for this igniter collar. It is described that the pressure bulkhead including the cup member is fixed to the housing by fitting the member.

However, the pressure rise generated in the second combustion chamber due to the combustion of the second gas generating agent is generally accompanied by a very steep rise in pressure, and the impact force applied to the pressure bulkhead by this rise in pressure. Will be very large. Therefore, if the above-mentioned assembly structure using press-fitting is adopted without taking any measures, there is a very high possibility that the pressure bulkhead will fall off from the housing due to this large impact force. When this dropout occurs, the combustion of the gas generating agent is not intended, so that the desired gas output cannot be obtained, and the reliability becomes inferior in terms of performance.

More specifically, as disclosed in Patent Document 1, if the cup member as the pressure bulkhead is simply fitted into the igniter collar, a considerably high assembly strength is realized. Even if it is press-fitted and fixed, the closed end of the cup member directly receives the above-mentioned impact force when the second gas generating agent is burned, and the first combustion is performed when the first gas generating agent is burned. Coupled with the fact that the housing has already been deformed so as to bulge outward as the pressure in the chamber rises, the cup member may fall off from the igniter collar.

Therefore, the present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide a gas generator having a dual structure having a simple structure in which a desired gas output can be stably obtained.

The gas generator based on the present invention includes a housing, a filter, a partition, a first igniter, a second igniter, and a holder. The housing includes a peripheral wall portion provided with a gas outlet, a top plate portion that closes one end of the peripheral wall portion in the axial direction, and a bottom plate portion that closes the other end of the peripheral wall portion in the axial direction. .. The filter is composed of a tubular member housed inside the housing so that its outer peripheral surface faces the inner peripheral surface of the peripheral wall portion. The partition portion has a cup-like shape as a whole having a closed end on the top plate portion side, and by being assembled to the bottom plate portion, the space inside the filter is created by the first gas generating agent. It is divided into a first combustion chamber in which the gas is housed and a second combustion chamber in which the second gas generating agent is housed. The first igniter is assembled to the bottom plate portion so as to face the first combustion chamber, which is a space outside the partition portion. The second igniter is assembled to the bottom plate portion so as to face the second combustion chamber, which is a space inside the partition portion. The holder is fixed to the bottom plate portion and holds the second igniter to assemble the second igniter to the bottom plate portion.

The partition portion has a partition wall member provided with a tubular portion facing the inner peripheral surface of the filter, and a cover member assembled to the partition wall member. At the axial end of the partition member on the top plate side, an opening that opens toward the top plate is provided. The cover member includes a first cover portion that constitutes the closed end by covering the axial end portion of the partition wall member on the top plate portion side, and the cover member along the axial direction of the tubular portion from the first cover portion. It has a cup-like shape including a second covering portion that comes into close contact with the outer peripheral surface of the tubular portion and covers the tubular portion. The holder is arranged so as to project from the bottom plate portion toward the space inside the filter. By press-fitting the axial end portion of the partition wall member on the bottom plate portion side into the holder, the partition portion is assembled to the bottom plate portion via the holder.

The cover member includes a fragile portion that can be cleaved by an increase in the internal pressure of the second combustion chamber and a non-fragile portion that does not cleave by an increase in the internal pressure of the second combustion chamber. Includes. The first covering portion is composed of only the invulnerable portion, and the second covering portion is composed of the openable portion and the inaccessible portion.

In the disc-type gas generator based on the present invention, the above is not possible due to the increase in the internal pressure of the second combustion chamber caused by the combustion of the second gas generator during the operation of the second igniter. By receiving the internal pressure of the second combustion chamber through the opening, the first covering portion consisting of only the opening portion keeps the second covering portion in close contact with the tubular portion, while maintaining the cover. The member moves toward the top plate portion side. Along with this, the openable portion of the second covering portion is exposed so as to face the second combustion chamber at a position closer to the top plate portion than the partition wall member, so that the second combustion chamber is exposed. It is cleaved by receiving the internal pressure, whereby the gas generated in the second combustion chamber is introduced into the first combustion chamber.

In the gas generator based on the present invention, the partition wall member has a cup-like shape having a top wall portion located at the axial end portion of the tubular portion on the top plate portion side. In that case, it is preferable that the opening is provided in the top wall portion.

In the gas generator based on the present invention, the partition wall member may be composed of only the tubular portion, and in that case, the opening is on the top plate side of the tubular portion. It is defined by the opening end located at the axial end of.

In the gas generator based on the present invention, the openable portion may be provided in an annular shape on the second covering portion so as to extend along the circumferential direction of the partition wall member.

In the gas generator based on the present invention, it is preferable that the crackable portion is provided in the second covering portion of the portion adjacent to the first covering portion.

The gas generator based on the present invention may be configured so that the movement of the cover member during the operation of the second igniter is restricted by the top plate portion.

In the gas generator based on the present invention, due to the increase in the internal pressure of the first combustion chamber caused by the combustion of the first gas generator during the operation of the first igniter, the sky By deforming the plate portion so as to bulge outward, the distance between the top plate portion and the first covering portion may be increased. In that case, it is preferable that the increase in this distance is included in the movement margin of the cover member when the second igniter is operated.

The gas generator based on the present invention may further include an upper support member arranged in the space inside the filter so as to support the end portion of the filter on the top plate side. In that case, it is preferable that the upper support member has a cup-like shape addressed to the boundary portion between the filter and the top plate portion, and the top plate portion of the partition wall member. It is preferable that the axial end portion on the side is arranged inside the upper support member.

According to the present invention, it is possible to obtain a gas generator having a dual structure having a simple structure in which a desired gas output can be stably obtained.

It is a schematic sectional view of the disk type gas generator which concerns on Embodiment 1. FIG. It is a schematic cross-sectional view along the line II-II shown in FIG. It is an exploded perspective view which shows the assembly structure of the partition part shown in FIG. It is a schematic cross-sectional view which shows the 1st stage in operation of the disk type gas generator shown in FIG. It is a schematic sectional view which shows the 2nd stage at the time of operation of the disk type gas generator shown in FIG. It is a schematic cross-sectional view which shows the 3rd stage at the time of operation of the disk type gas generator shown in FIG. It is an exploded perspective view which shows the other structural example of the partition part shown in FIG. It is a schematic sectional view of the disk type gas generator which concerns on Embodiment 2. FIG. It is an exploded perspective view which shows the assembly structure of the partition part shown in FIG. It is a schematic cross-sectional view which shows the 2nd stage at the time of operation of the disk type gas generator shown in FIG. It is a schematic cross-sectional view which shows the 3rd stage at the time of operation of the disk type gas generator shown in FIG.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The following embodiments are applications of the present invention to a dual-structured disc-type gas generator that is suitably incorporated into an airbag device mounted on a steering wheel of an automobile or the like. In the embodiments shown below, the same or common parts are designated by the same reference numerals in the drawings, and the description thereof will not be repeated.

(Embodiment 1)
FIG. 1 is a schematic cross-sectional view of the disc-type gas generator according to the first embodiment, and FIG. 2 is a schematic cross-sectional view taken along the line II-II shown in FIG. Further, FIG. 3 is an exploded perspective view showing an assembled structure of the partition portion shown in FIG. 1. First, the configuration of the disc-type gas generator 1A according to the present embodiment will be described with reference to FIGS. 1 to 3.

As shown in FIGS. 1 and 2, the disc-type gas generator 1A has a short substantially cylindrical housing in which one end and the other end in the axial direction are closed, and the housing provided inside the housing is provided. In the space, the first igniter assembly 30, the second igniter assembly 40, the first gas generator 51, the second gas generator 52, the lower support member 61, the upper support member 62, and the filter as internal components. 70 etc. are housed.

As shown in FIG. 1, the housing includes a lower shell 10 and an upper shell 20. Each of the lower shell 10 and the upper shell 20 is made of a press-formed product formed by, for example, pressing a rolled metal plate-like member. As the metal plate-like member constituting the lower shell 10 and the upper shell 20, for example, a metal plate made of stainless steel, steel, an aluminum alloy, or the like is used, and preferably 440 [MPa] or more and 780 [MPa]. A so-called high-strength steel sheet that does not break or break even when the following tensile stress is applied is used.

The lower shell 10 and the upper shell 20 are each formed in a substantially cylindrical shape with a bottom, and the housing is formed by combining and joining these opening surfaces so as to face each other. The lower shell 10 has a bottom plate portion 11 and a peripheral wall portion 12, and the upper shell 20 has a top plate portion 21, a peripheral wall portion 22, and a flange portion 23.

The upper end of the peripheral wall portion 12 of the lower shell 10 is press-fitted by being inserted into the lower end of the peripheral wall portion 22 of the upper shell 20. Further, the peripheral wall portion 12 of the lower shell 10 and the peripheral wall portion 22 of the upper shell 20 are joined to each other at or near their contact portions, whereby the lower shell 10 and the upper shell 20 are fixed. ing. Here, electron beam welding, laser welding, friction welding and the like can be preferably used for joining the lower shell 10 and the upper shell 20.

As a result, the portion of the peripheral wall portion of the housing near the bottom plate portion 11 is composed of the peripheral wall portion 12 of the lower shell 10, and the portion of the peripheral wall portion of the housing near the top plate portion 21 is on the upper side. It is composed of a peripheral wall portion 22 of the shell 20. Further, one end and the other end of the housing in the axial direction (that is, the axial direction of the peripheral wall portions 12 and 22) are closed by the bottom plate portion 11 of the lower shell 10 and the top plate portion 21 of the upper shell 20, respectively.

The flange portion 23 provided on the upper shell 20 is a portion for fixing the disc type gas generator 1A to an external member (for example, a retainer provided in the airbag device). A through hole (the through hole does not appear in the drawing) is provided at a predetermined position of the flange portion 23 so as to penetrate along a direction parallel to the axial direction of the housing. A fastening member such as a bolt is inserted into the through hole, whereby the disc type gas generator 1A is fixed to the external member.

A first opening 11a and a second opening 11b are provided at predetermined positions of the bottom plate portion 11 of the lower shell 10. A first igniter assembly 30 is assembled to the bottom plate portion 11 of the lower shell 10 so as to close the first opening 11a, and a second igniter is attached so as to close the second opening 11b. The assembly 40 is assembled. Here, the first opening 11a is a portion for exposing the first female connector portion, which will be described later, provided at the lower end of the first igniter assembly 30 to the outside, and the second opening 11b is , A portion for exposing the second female connector portion, which will be described later, provided at the lower end of the second igniter assembly 40 to the outside.

The first igniter assembly 30 mainly includes a first holder 31, a first igniter 32, a first seal member 33, a cup body 34, and a gunpowder 36. The first holder 31 constitutes the base of the first igniter assembly 30, and by assembling the first igniter 32, the cup body 34, and the like to the first holder 31, the first igniter assembly The solid 30 is configured as an integral part.

The first holder 31 is made of a member having a substantially columnar outer shape, and is made of a metal member such as stainless steel, steel, or an aluminum alloy. An upper recess 31a is provided on the upper surface of the first holder 31 located on the top plate portion 21 side, and a lower recess 31b is provided on the lower surface of the first holder 31 located on the bottom plate portion 11 side. There is. Further, the first holder 31 of the portion forming the bottom of the upper recess 31a and the bottom of the lower recess 31b is provided with a through hole 31c so as to reach the upper recess 31a and the lower recess 31b.

Further, on the upper surface of the first holder 31, caulking portions 31d and 31e are provided so as to surround the upper concave portion 31a. The caulking portion 31d arranged inside is a portion for caulking and fixing the first igniter 32 to the first holder 31, and the caulking portion 31e arranged outside of these is a portion for caulking the cup body 34. It is a part for caulking and fixing to the first holder 31.

The first igniter 32 is for generating a flame, and is made of a pyrotechnic product generally called a squib. The first igniter 32 has a base portion 32a, an ignition portion 32b, and a pair of terminal pins 32c. The base portion 32a is a portion that holds the ignition portion 32b and the pair of terminal pins 32c, and is also a portion that is fixed to the first holder 31. The ignition unit 32b includes an ignition agent that ignites and burns during operation to generate a flame, and a resistor (bridge wire) for igniting the ignition agent. The pair of terminal pins 32c are connected to the ignition unit 32b to ignite the ignition charge.

More specifically, the base portion 32a and the ignition portion 32b include a squib cup formed in a cup shape and an embolus that closes the open end of the squib cup and a pair of terminal pins 32c is inserted and held therein. The above-mentioned resistor is attached so as to connect the tips of the pair of terminal pins 32c inserted in the squib cup, and the resistor is placed in the squib cup so as to surround or approach the resistor. It has a configuration loaded with an igniter.

Here, nichrome wire or the like is generally used as the resistor, and ZPP (zirconium / potassium perchlorate), ZWPP (zirconium / tungsten / potassium perchlorate), lead styphnate or the like is generally used as the ignition agent. The squib cup and embolus described above are generally made of metal or plastic.

When a collision is detected, a predetermined amount of current flows through the resistor via the terminal pin 32c. When a predetermined amount of electric current flows through the resistor, Joule heat is generated in the resistor and the igniter starts combustion. The hot flame generated by the combustion bursts the squib cup containing the igniter. The time from when a current flows through the resistor until the first igniter 32 operates is generally 2 [ms] or less when a nichrome wire is used for the resistor.

In the first igniter 32, a pair of terminal pins 32c are inserted into the through holes 31c of the first holder 31 from above, and the base portion 32a is accommodated and fastened in the upper recess 31a of the first holder 31. The caulked portion 31d described above is fixed to the first holder 31 by being bent.

Here, a first seal member 33 made of an O-ring or the like is interposed between the first holder 31 and the first igniter 32, whereby the first holder 31 and the first igniter 32 are connected to each other. Airtightness is ensured in the portion by closing the gap between them. The fixing method of the first igniter 32 is not limited to the fixing method using the caulking portion 31d described above, and other fixing methods may be used.

The cup body 34 has a cup-like shape in which the end portion on the bottom plate portion 11 side is open, and includes a fire transmission chamber 35 in which the fire spread agent 36 is housed. The cup body 34 has a top wall portion 34a and a side wall portion 34b that define the fire transmission chamber 35, and a flange portion 34c that extends radially outward from a portion of the side wall portion 34b on the opening end side. There is.

The cup body 34 is assembled to the first holder 31 so that the fire transmission room 35 formed inside the cup body 34 faces the ignition portion 32b of the first igniter 32, and more specifically, the flange portion 34c is attached. The caulked portion 31e described above is bent to be fixed to the first holder 31 in a state of being attached to the upper surface of the first holder 31.

The cup body 34 does not have an opening in either the top wall portion 34a or the side wall portion 34b, and surrounds the fire transmission room 35 provided inside the cup body 34. This cup body 34 bursts or melts as the pressure rises in the fire transmission room 35 and the conduction of the generated heat when the ignition charge 36 is ignited by the operation of the first igniter 32. Those with relatively low mechanical strength are used.

Therefore, the cup body 34 includes metal members such as aluminum and aluminum alloys, thermosetting resins typified by epoxy resins, polybutylene terephthalate resins, polyethylene terephthalates resins, and polyamide resins (for example, nylon 6 and nylon 66). Etc.), a member made of a resin such as a thermoplastic resin typified by a polypropylene sulfide resin or a polypropylene oxide resin is preferably used.

In addition to such a cup body 34, the cup body 34 is made of a metal member having high mechanical strength such as iron or copper, and has an opening on the side wall portion thereof. It is also possible to use one provided with a sealing member so as to close it. In this case, the combustion of the explosive charge 36 causes the sealing member to be cleaved or melted, thereby opening the above-mentioned opening. Here, as the above-mentioned sealing member, a sealing tape that can be attached to the cup body so as to close the opening, or a ring-shaped sealing body that can be assembled by press fitting to the cup body so as to close the opening. Etc. can be used. As the sealing tape, for example, an aluminum foil having an adhesive member coated on one side can be preferably used, and as the ring-shaped sealing body, an aluminum press-molded product including a thin plate tubular portion for closing the above-mentioned opening or the like can be preferably used. Can be preferably used. Further, the fixing method of the cup body 34 is not limited to the fixing method using the crimped portion 31e described above, and other fixing methods may be used.

The explosive charge 36 filled in the firebox 35 is ignited by a flame generated by the operation of the first igniter 32 and burns to generate heat particles. The igniter 36 needs to be capable of reliably starting combustion of the first gas generating agent 51, and is generally B / KNO ₃ , B / NaNO ₃ , Sr (NO ₃ ). _A composition composed of a metal powder / oxidizing agent typified by ₂ or the like, a composition composed of titanium hydride / potassium perchlorate, a composition composed of B / 5-aminotetrazole / potassium nitrate / molybdenum trioxide, etc. are used. ..

As the explosive agent 36, a powdery one, a one molded into a predetermined shape by a binder, or the like is used. The shape of the explosive charge 36 formed by the binder includes various shapes such as a granular shape, a cylindrical shape, a sheet shape, a spherical shape, a single-hole cylindrical shape, a porous cylindrical shape, and a tablet shape.

The lower end of the first holder 31 is inserted from above into the first opening 11a provided in the bottom plate portion 11 of the lower shell 10, and the outer peripheral edge thereof is fixed by being joined to the bottom plate portion 11. ing. As a result, the first igniter assembly 30 integrated by assembling the first igniter 32 and the cup body 34 to the first holder 31 is fixed to the lower shell 10. Become.

Therefore, the first holder 31 is configured to be positioned so as to project from the bottom plate portion 11 toward the space inside the housing, and in particular, the fire transmission room provided inside the first igniter assembly 30. 35 will be placed in the space inside the housing. Here, electron beam welding, laser welding, friction welding, and the like can be preferably used for joining the bottom plate portion 11 and the first holder 31.

A pair of terminal pins 32c of the first igniter 32 are exposed and located in the lower recess 31b of the first holder 31. As a result, the lower concave portion 31b and the pair of terminal pins 32c form the above-mentioned first female connector portion.

The first female connector portion is a portion for receiving a male connector (not shown) of a harness for connecting the first igniter 32 and a control unit (not shown). The first female connector portion is exposed toward the outside of the housing, and the male connector described above is inserted into the first female connector portion to electrically connect the core wire of the harness and the terminal pin 32c. Continuity will be realized.

The second igniter assembly 40 mainly includes a second holder 41, a second igniter 42, a second seal member 43, a partition portion 44, and a second gas generating agent 52. The second holder 41 constitutes the base of the second igniter assembly 40, and by assembling the second igniter 42, the partition portion 44, and the like to the second holder 41, the second igniter assembly The solid 40 is configured as an integral part.

The second holder 41 is made of a member having a substantially columnar outer shape, and is made of a metal member such as stainless steel, steel, or an aluminum alloy. An upper recess 41a is provided on the upper surface of the second holder 41 located on the top plate portion 21 side, and a lower recess 41b is provided on the lower surface of the second holder 41 located on the bottom plate portion 11 side. There is. Further, the second holder 41 of the portion forming the bottom of the upper recess 41a and the bottom of the lower recess 41b is provided with a through hole 41c so as to reach the upper recess 41a and the lower recess 41b.

Further, a caulking portion 41d is provided on the upper surface of the second holder 41 so as to surround the upper recess 41a. The caulking portion 41d is a portion for caulking and fixing the second igniter 42 to the second holder 41.

The second igniter 42 is for generating a flame, and like the first igniter 32 described above, is made of a pyrotechnic product generally called a squib. The second igniter 42 has a base portion 42a, an ignition portion 42b, and a pair of terminal pins 42c. The base portion 42a is a portion that holds the ignition portion 42b and the pair of terminal pins 42c, and is also a portion that is fixed to the second holder 41. The ignition unit 42b includes an ignition agent that ignites and burns during operation to generate a flame, and a resistor (bridge wire) for igniting the ignition agent. The pair of terminal pins 42c are connected to the ignition unit 42b to ignite the ignition charge.

Since the second igniter 42 basically has the same configuration as the first igniter 32 described above, detailed description thereof will be omitted here.

The second igniter 42 has a pair of terminal pins 42c inserted into the through holes 41c of the second holder 41 from above, and the base portion 42a is accommodated and fastened in the upper recess 41a of the second holder 41. The caulked portion 41d described above is fixed to the second holder 41 by being bent.

Here, a second seal member 43 made of an O-ring or the like is interposed between the second holder 41 and the second igniter 42, whereby the second holder 41 and the second igniter 42 are connected to each other. Airtightness is ensured in the portion by closing the gap between them. The fixing method of the second igniter 42 is not limited to the fixing method using the caulking portion 41d described above, and other fixing methods may be used.

The partition portion 44 has a partition wall member 45 and a cover member 46, and the partition wall member 45 and the cover member 46 are combined to form a cup-like shape as a whole. The partition 44 functions as a pressure bulkhead that divides the space inside the housing and the space inside the filter 70 into two chambers.

The space inside the housing and inside the filter 70 is partitioned by a partition 44 into a space outside the partition 44 and a space inside the partition 44. The former space is defined as the first combustion chamber S1, and the latter space is defined as the second combustion chamber S2.

The partition portion 44 is assembled to the second holder 41 so that the second combustion chamber S2 formed inside the partition portion 44 faces the ignition portion 42b of the second igniter 42. More specifically, as will be described later, the fixing portion 45b1 provided at the lower end of the partition wall member 45 of the partition portion 44 is press-fitted into the second holder 41, so that the partition portion 44 passes through the second holder 41. It is assembled to the bottom plate portion 11.

The second gas generating agent 52 is housed in the second combustion chamber S2 located inside the partition portion 44. The second gas generating agent 52 is an agent that generates gas by being ignited by heat particles generated by the operation of the second igniter 42 and burning. The details of the second gas generating agent 52 will be described later.

As shown in FIGS. 1 to 3, the partition wall member 45 has a substantially cylindrical shape with a bottom having an opening at the end on the bottom plate portion 11 side, and is made of a metal such as stainless steel, steel, or aluminum alloy, for example. It is composed of the members of. The partition wall member 45 has a substantially cylindrical tubular portion 45b facing the inner peripheral surface of the filter 70 and a substantially disc-shaped top wall portion 45a located at the axial end of the tubular portion 45b on the top plate portion 21 side. And have. The tubular portion 45b extends from the peripheral edge of the top wall portion 45a toward the bottom plate portion 11 side along the axial direction of the partition wall member 45.

The partition wall member 45 is assembled to the bottom plate portion 11 by inserting the opening end provided at the lower end thereof into the second holder 41. More specifically, the lower end of the tubular portion 45b of the partition member 45 functions as a fixing portion 45b1 fixed to the second holder 41, and more specifically, the fixing portion 45b1 is attached to the second holder 41. By press-fitting, the partition wall member 45 is fixed to the second holder 41 and is assembled to the bottom plate portion 11.

An opening 45c is provided in the top wall portion 45a of the partition wall member 45. On the other hand, the tubular portion 45b of the partition member 45 is not provided with an opening. In the present embodiment, a single opening 45c is provided in the central portion of the top wall portion 45a of the partition wall member 45, and the opening 45c is the top wall along the thickness direction of the top wall portion 45a. It is provided so as to penetrate the portion 45a. The opening 45c is for passing the gas generated in the second combustion chamber S2 toward the first combustion chamber S1.

As shown in FIGS. 1 and 3, the cover member 46 has a bottomed tubular shape in which the end on the bottom plate portion 11 side is open, and the axial end on the top plate portion 21 side of the partition wall member 45. It is assembled in the department. Like the partition wall member 45, the cover member 46 is made of a metal member such as stainless steel, steel, or an aluminum alloy, and more preferably a member made of an aluminum alloy.

The cover member 46 includes a disk-shaped first covering portion 46a that forms a closed end of the partition portion 44 by covering the opening 45c provided at the axial end portion of the partition wall member 45 on the top plate portion 21 side. Includes a cylindrical second covering portion 46b that covers the outer peripheral surface of the partition wall member 45 near the top plate portion 21 by extending from the peripheral edge of the first covering portion 46a toward the bottom plate portion 11 side. I'm out.

The cover member 46 is attached to the partition wall member 45 by being externally inserted into the above-mentioned axial end portion of the partition wall member 45, and is preferably fixed to the partition wall member 45 by press fitting. As a result, the inner peripheral surface of the second covering portion 46b of the cover member 46 is in close contact with the outer peripheral surface of the portion of the partition wall member 45 near the top plate portion 21.

Here, the cover member 46 is composed of a single member, and includes a crackable portion made of a fragile portion and an inaccessible portion made of a non-fragile member. The openable part is a part that can be opened by receiving the internal pressure of the second combustion chamber S2 when the internal pressure of the second combustion chamber S2 rises during the operation of the disc type gas generator 1A described later. It is a site that does not cleave even when it receives the pressure.

In the present embodiment, the fragile portion is formed by making the thickness of the cover member 46 of the portion constituting the fragile portion relatively thin, and is composed of a non-fragile portion. The invulnerable portion is formed by making the thickness of the cover member 46 of the portion constituting the invulnerable portion relatively thick.

The first cover portion 46a of the cover member 46 is composed of only the above-mentioned non-split portion, and the second cover portion 46b of the cover member 46 is composed of the above-mentioned invultable portion and the non-split portion. It is configured. Of these, the fisible portion (that is, the fragile portion 46b1 shown in the drawing) provided in the second covering portion 46b is provided in the second covering portion 46b of the portion adjacent to the first covering portion 46a. The fragile portion 46b1 is located in an annular shape so as to extend along the circumferential direction of the partition wall member 45, and is formed in a cylindrical shape.

In other words, the first covering portion 46a and the portion of the second covering portion 46b excluding the fragile portion 46b1 are both formed of an inseparable portion and are formed into a disk shape and a cylindrical shape, respectively. Has been done. As a result, the above-mentioned fragile portion 46b1 as a fisible portion connects the first covering portion 46a as an inviolable portion and the portion of the second covering portion 46b configured as an inviolable portion. It is located to do.

Here, the fragile portion 46b1 is covered with a partition wall member 45 arranged inside the cover member 46 when viewed from the side where the second combustion chamber S2 is located, whereby the second combustion chamber S2 is covered. It does not face, but faces only the first combustion chamber S1.

As shown in FIG. 1, the lower end of the second holder 41 is inserted from above into the second opening 11b provided in the bottom plate portion 11 of the lower shell 10, and the outer peripheral edge thereof is inserted with respect to the bottom plate portion 11. It is fixed by being joined. As a result, the second igniter assembly 40 integrated by assembling the second igniter 42, the partition portion 44, and the like to the second holder 41 is fixed to the lower shell 10. Become.

Therefore, the second holder 41 is configured to be positioned so as to project from the bottom plate portion 11 toward the space inside the housing, and in particular, the second combustion provided inside the second igniter assembly 40. The chamber S2 will be arranged in the space inside the housing. Here, electron beam welding, laser welding, friction welding, and the like can be preferably used for joining the bottom plate portion 11 and the second holder 41.

A pair of terminal pins 42c of the second igniter 42 are exposed and located in the lower recess 41b of the second holder 41. As a result, the lower recess 41b and the pair of terminal pins 42c form the above-mentioned second female connector portion.

The second female connector portion is a portion for receiving a male connector (not shown) of a harness for connecting the second igniter 42 and a control unit (not shown). The second female connector portion is exposed toward the outside of the housing, and the male connector described above is inserted into the second female connector portion to electrically connect the core wire of the harness and the terminal pin 42c. Continuity will be realized.

As shown in FIGS. 1 and 2, the space inside the housing accommodates a filter 70 in addition to the first igniter assembly 30 and the second igniter assembly 40 described above. The filter 70 has a cylindrical shape, and is arranged coaxially with the housing so that its central axis coincides with the central axis of the peripheral wall portion of the housing. As a result, the outer peripheral surface of the filter 70 faces the inner peripheral surface of the peripheral wall portion of the housing.

The filter 70 surrounds the first igniter assembly 30 and the second igniter assembly 40 so that the first igniter assembly 30 and the second igniter assembly 40 are arranged in the space inside the filter 70. Is located in. As a result, the first combustion chamber S1 in which the first gas generating agent 51 is housed is formed in the space inside the filter 70 and in the space outside the partition portion 44. The filter 70 is arranged at a predetermined distance from the peripheral wall portion of the housing, whereby a gas discharge chamber S3 is formed between the peripheral wall portion of the housing and the filter 70.

As the filter 70, for example, one obtained by winding and sintering a metal wire such as stainless steel or steel, or one in which a net material woven with a metal wire is pressed and compacted can be used. As the net material, specifically, a knitted wire net, a plain weave wire net, an aggregate of crimp-woven metal wire, and the like can be used.

Further, as the filter 70, a filter 70 obtained by winding a perforated metal plate or the like can also be used. In this case, as the perforated metal plate, for example, expanded metal in which a staggered cut is made in the metal plate and the metal plate is expanded to form a hole and processed into a mesh shape, or an expanded metal in which a hole is made in the metal plate and at that time. Hook metal or the like flattened by crushing burrs generated on the periphery of the hole is used. In this case, the size and shape of the holes to be formed can be appropriately changed as needed, and holes of different sizes and shapes may be included on the same metal plate. As the metal plate, for example, a steel plate (mild steel) or a stainless steel plate can be preferably used, and a non-ferrous metal plate such as aluminum, copper, titanium, nickel or an alloy thereof can also be used.

The filter 70 functions as a cooling means for cooling the gas by taking away the high-temperature heat of the gas when the gas generated in the first combustion chamber S1 and the second combustion chamber S2 passes through the filter 70. At the same time, it also functions as a removing means for removing residues (slag) and the like contained in the gas. Therefore, in order to sufficiently cool the gas and prevent the residue from being released to the outside, the gas generated in the first combustion chamber S1 and the second combustion chamber S2 is configured to surely pass through the filter 70. It is necessary to do.

Here, the first igniter assembly 30 is eccentrically arranged so that its central axis does not overlap with the central axis of the peripheral wall portion of the housing, and the central axis of the second igniter assembly 40 is also the peripheral wall of the housing. It is eccentrically arranged so as not to overlap the central axis of the portion (that is, the central axis of the partition portion 44 (more strictly, the central axis of the partition wall member 45) does not overlap with the central axis of the peripheral wall portion of the housing). With such a configuration, it is possible to prevent a dead space from being generated inside the housing (particularly the space inside the filter 70), and the disc type gas generator 1A can be configured to be compact as a whole.

The first gas generating agent 51 is housed in the first combustion chamber S1. More specifically, the first gas generating agent 51 is a space inside the filter 70 and adjacent to the top wall portion 34a and the side wall portion 34b of the cup body 34 of the first igniter assembly 30, and the space. , It is arranged in the space inside the filter 70 and adjacent to the side wall portion of the partition portion 44 of the second igniter assembly 40. The first gas generating agent 51 is an agent that generates gas by being ignited by heat particles generated by the operation of the first igniter 32 and burning.

As the first gas generating agent 51 and the second gas generating agent 52 described above, it is preferable to use a non-azide gas generating agent, and generally, these first gas generating agents are used as a molded product containing a fuel, an oxidizing agent and an additive. 51 and the second gas generating agent 52 are formed.

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.

Examples of the oxidizing agent include basic metal hydroxides such as basic copper nitrate and basic copper carbonate, perchlorates such as ammonium perchlorate and potassium perchlorate, alkali metals, alkaline earth metals, and transition metals. , Nitrate containing cations selected from ammonia and the like are used. As the nitrate, for example, sodium nitrate, potassium nitrate and the like are preferably used.

Examples of the additive include a binder, a slag forming agent, a combustion adjusting agent, and the like. As the binder, for example, an organic binder such as polyvinyl alcohol, a metal salt of carboxymethyl cellulose, or stearate, or an inorganic binder such as synthetic hydrotalcite or acidic clay can be preferably used. In addition, as binders, polysaccharide derivatives such as hydroxyethyl cellulose, hydroxypropylmethyl cellulose, cellulose acetate, cellulose propionate, cellulose acetate butyrate, nitrocellulose, microcrystalline cellulose, guagam, polyvinylpyrrolidone, polyacrylamide, and starch are used. Alternatively, inorganic binders such as molybdenum disulfide, starch, bentonite, silica soil, kaolin, and alumina can also be preferably used. As the slag forming agent, silicon nitride, silica, acidic white clay and the like can be preferably used. As the combustion modifier, metal oxides, ferrosilicon, activated carbon, graphite and the like can be preferably used.

There are various shapes of the molded body of the gas generating agent, such as granular ones such as granules, pellets, and cylinders, and discs. Further, in the columnar shape, a perforated (for example, single-hole tubular shape, perforated tubular shape, etc.) molded body having a through hole inside the molded body is also used. These shapes are preferably selected as appropriate according to the specifications of the airbag device in which the disc-type gas generator 1A is incorporated. For example, a shape in which the gas generation rate changes with time when the gas generator is burned. It is preferable to select the optimum shape according to the specifications, such as selection. Further, it is preferable to appropriately select the size and filling amount of the molded product in consideration of the linear combustion rate of the gas generating agent, the pressure index, and the like in addition to the shape of the gas generating agent.

Here, the first gas generating agent 51 and the second gas generating agent 52 may have the same composition or may have different compositions. Further, the first gas generating agent 51 and the second gas generating agent 52 may have the same shape and size, or may have different shapes and sizes.

A plurality of gas outlets 24 are provided on the peripheral wall portion 22 of the upper shell 20 of the portion facing the filter 70 so as to face the gas discharge chamber S3. The plurality of gas outlets 24 are for leading the gas that has passed through the filter 70 to the outside of the housing via the gas discharge chamber S3.

Further, a metal sealing tape 25 as a sealing member is attached to the inner peripheral surface of the peripheral wall portion 22 of the upper shell 20 so as to close the plurality of gas ejection ports 24. As the sealing tape 25, an aluminum foil or the like having an adhesive member coated on one side can be preferably used, and the sealing tape 25 ensures the airtightness of the space inside the housing.

As shown in FIG. 1, a lower support member 61 is arranged at an end of the first combustion chamber S1 located on the bottom plate portion 11 side. The lower support member 61 has an annular shape, and is arranged so as to cover the boundary portion between the filter 70 and the bottom plate portion 11 so as to cover the filter 70 and the bottom plate portion 11. As a result, the lower support member 61 is located between the bottom plate portion 11 and the first gas generating agent 51 in the vicinity of the end portion of the first combustion chamber S1.

The lower support member 61 is a member for fixing the filter 70 to the housing, and the gas generated in the first combustion chamber S1 and the second combustion chamber S2 passes through the inside of the filter 70 during operation. It also functions as an outflow prevention means for preventing outflow from the gap between the lower end of the filter 70 and the bottom plate portion 11. The lower support member 61 is formed by, for example, pressing a metal plate-shaped member, and is preferably made of a steel plate such as ordinary steel or special steel (for example, a cold-rolled steel plate or a stainless steel plate). It is composed of members.

An upper support member 62 is arranged at an end of the first combustion chamber S1 located on the top plate portion 21 side. The upper support member 62 has a cup-like shape, and is arranged so as to cover the boundary portion between the filter 70 and the top plate portion 21 so as to be addressed to the filter 70 and the top plate portion 21. .. As a result, the upper support member 62 is located between the top plate portion 21 and the first gas generating agent 51 in the vicinity of the end portion of the first combustion chamber S1.

The upper support member 62 is a member for fixing the filter 70 to the housing, and the gas generated in the first combustion chamber S1 and the second combustion chamber S2 does not pass through the inside of the filter 70 during operation. It also functions as an outflow prevention means for preventing outflow from the gap between the upper end of the filter 70 and the top plate portion 21. Similar to the lower support member 61 described above, the upper support member 62 is formed by, for example, pressing a metal plate-shaped member, and is preferably a steel plate such as ordinary steel or special steel (for example,). It is composed of members made of cold-rolled steel sheets, stainless steel sheets, etc.).

Inside the upper support member 62, a cushion material 63 having a substantially C-shape in a plan view is arranged so as to come into contact with the first gas generating agent 51 housed in the first combustion chamber S1. As a result, the cushion material 63 is located between the top plate portion 21 and the first gas generating agent 51 in the portion of the first combustion chamber S1 on the top plate portion 21 side, and the first gas generating agent 51 is used. It is pressed toward the bottom plate portion 11.

The cushion material 63 is provided for the purpose of preventing the first gas generating agent 51 made of a molded body from being crushed by vibration or the like, and is preferably a molded body of ceramic fiber, rock wool, or foamed resin ( For example, it is composed of a member made of foamed silicone, expanded polypropylene, foamed polyethylene, urethane foam, etc.), chloroprene, rubber typified by EPDM, and the like. The cushion material 63 is burned down by the combustion of the first gas generating agent 51.

If some measures are required to prevent the second gas generating agent 52 from being crushed due to vibration, this can be realized by using a cushion material as in the case of the first gas generating agent 51. In that case, a disk-shaped cushioning material is arranged between the top wall portion 45a of the partition wall member 45 and the second gas generating agent 52, or a ring-shaped cushioning material is placed on the second igniter 42. It can be either arranged between the upper surface of the second holder 41 of the surrounding portion and the second gas generating agent 52.

When the former configuration is adopted, the second gas generating agent 52 is pressed toward the bottom plate portion 11 side by the cushion material, and when the latter configuration is adopted, the second gas is pressed by the cushion material. The generating agent 52 is pressed toward the top plate portion 21 side. In addition, both the former configuration and the latter configuration may be adopted. Here, as the cushioning material for pressing the second gas generating agent 52 described above, the same material as the cushioning material 63 for pressing the first gas generating agent 51 can be used.

4 to 6 are schematic cross-sectional views showing the first to third stages of the operation of the disc type gas generator according to the present embodiment, respectively. Next, the operation of the disc-type gas generator 1A according to the present embodiment will be described with reference to FIGS. 4 to 6.

When a vehicle equipped with a disc-type gas generator 1A collides, the collision is detected by a collision detection means separately provided in the vehicle, and based on this, electricity is received from a control unit separately provided in the vehicle. First, the first igniter 32 operates.

As shown in FIG. 4, in the first stage in which the first igniter 32 is operated, the igniter filled in the ignition portion 32b of the first igniter 32 is ignited by being heated by the resistor. The combustion of the explosive causes the ignition unit 32b to explode. As a result, the explosive charge 36 housed inside the cup body 34 is ignited and burned.

When the fire-transmitting agent 36 burns, a large amount of heat particles are generated inside the fire-transmitting room 35, and the temperature and pressure of the fire-burning room 35 rise, so that the cup body 34 made of a fragile member bursts or melts. .. When the cup body 34 bursts or melts, a large amount of the above-mentioned heat particles flow into the portion of the first combustion chamber S1 in which the first gas generating agent 51 is housed.

When a large amount of heat particles flow into the portion of the first combustion chamber S1, the first gas generating agent 51 contained in the first combustion chamber S1 is sequentially ignited and burned, whereby in the first combustion chamber S1. A large amount of gas is generated. The gas generated in the first combustion chamber S1 passes through the inside of the filter 70, and at that time, heat is taken away by the filter 70 and cooled, and the slag contained in the gas is removed by the filter 70 to make the gas. It flows into the discharge chamber S3.

At this time, the sealing tape 25 that has closed the plurality of gas outlets 24 is cleaved due to the pressure increase inside the housing caused by the combustion of the first gas generating agent 51. As a result, the gas generated in the first combustion chamber S1 is started to be ejected toward the outside of the housing through the plurality of gas outlets 24 (see arrow AR1).

In this first stage, the gas ejected from the plurality of gas outlets 24 to the outside of the disc-type gas generator 1A is introduced into the inside of the airbag provided adjacent to the disc-type gas generator 1A. The airbag is inflated and deployed.

At this time, the bottom plate portion 11 of the lower shell 10 and the top plate portion 21 of the upper shell 20 are outside due to the pressure increase inside the housing caused by the combustion of the first gas generating agent 51. It deforms so that it swells toward. As a result, the distance between the top plate portion 21 of the upper shell 20 and the end portion of the partition portion 44 on the top plate portion 21 side is increased.

On the other hand, in this first stage, the cover member 46 is pressed against the partition wall member 45 due to the pressure increase in the first combustion chamber S1 caused by the combustion of the first gas generating agent 51. .. Therefore, the top wall portion 45a of the partition wall member 45 and the end portions of the tubular portion 45b on the top plate portion 21 side are covered by the first cover portion 46a and the second cover portion 46b of the cover member 46, respectively, and these first cover portions It is in close contact with the 46a and the second covering portion 46b.

In this state, the fragile portion 46b1 provided in the second covering portion 46b is in a state of facing the tubular portion 45b of the partition wall member 45, whereby the fragile portion 46b1 becomes the first combustion chamber S1 and It faces only the first combustion chamber S1 of the second combustion chamber S2.

As a result, the state in which the opening 45c provided in the top wall portion 45a of the partition wall member 45 is closed by the cover member 46 is maintained. Therefore, in the first stage, the first combustion chamber S1 and the second combustion chamber S2 are not in a state of communication with each other, and the first gas generating agent 51 is connected to the second gas generating agent 52 whose combustion has not yet started. No longer affected by combustion.

Next, at a timing delayed by a predetermined time from the operation of the first igniter 32 described above, the second igniter 42 operates by receiving the energization from the control unit described above.

As shown in FIG. 5, in the second stage in which the second igniter 42 is operated, the igniter filled in the ignition portion 42b of the second igniter 42 is ignited by being heated by the resistor. The combustion of the explosive causes the ignition unit 42b to explode. As a result, the second gas generating agent 52 contained in the second combustion chamber S2 is sequentially ignited to start combustion.

Here, prior to the start of combustion of the second gas generator 52, the first gas generator 51 was ignited in advance and burned, so that the disk-type gas generator 1A as a whole was already heated to a high temperature. Since it is in the state, the combustion of the second gas generating agent 52 can be started smoothly without providing the ignition agent between the ignition unit 42b and the second gas generating agent 52, and the second gas generating agent 52 is generated. Combustion of the agent 52 becomes difficult to interrupt.

At that time, pressure is applied to the cover member 46 assembled to the partition wall member 45 due to the pressure increase in the second combustion chamber S2 caused by the combustion of the second gas generating agent 52. As a result, the cover member 46 moves toward the top plate portion 21 side of the upper shell 20 as a whole.

More specifically, the gas generated in the second combustion chamber S2 is sprayed toward the first covering portion 46a of the cover member 46 through the opening 45c provided in the top wall portion 45a of the partition wall member 45. (See arrow AR2). As a result, pressure acts mainly on the first covering portion 46a composed of only the inseparable portion in the direction along the axial direction of the housing, and based on this, the cover member 46 forms the top plate portion 21. Move towards the side. At this time, the cover member 46 is maintained in a state in which the inner peripheral surface of the second covering portion 46b is substantially in close contact with the outer peripheral surface of the tubular portion 45b of the partition wall member 45, and the entire cover member 46 is the top plate portion of the upper shell 20. It will move toward the 21 side.

At this time, pressure is also applied to the top wall portion 45a of the partition wall member 45. However, since the top wall portion 45a is provided with the opening 45c, the pressure applied to the top wall portion 45a is significantly smaller than that in the case where the top wall portion 45a is not provided with the opening 45c. Therefore, a large pressure is not applied to the partition wall member 45 along the axial direction of the housing, and as a result, the partition wall member 45 can be prevented from moving toward the top plate portion 21 side.

Here, in the present embodiment, when the movement of the cover member 46 in the second stage occurs by a predetermined amount, the movement of the cover member 46 is restricted by the top plate portion 21. There is. That is, the cover member 46 stops when it comes into contact with the top plate portion 21 via the upper support member 62.

After the cover member 46 is stopped, the end of the second cover portion 46b of the cover member 46 on the top plate portion 21 side where the fragile portion 46b1 is provided is located at the position on the top plate portion 21 side of the partition wall member 45. Will face the second combustion chamber S2. Therefore, the fragile portion 46b1 faces both the first combustion chamber S1 and the second combustion chamber S2.

Also in this second stage, the first gas generating agent 51 continues to burn in the first combustion chamber S1, so that the gas generated in the first combustion chamber S1 passes through the plurality of gas outlets 24 of the housing. It is ejected to the outside (see arrow AR1). As a result, even in the second stage, the gas ejected from the plurality of gas outlets 24 to the outside of the disc-type gas generator 1A generates the disc-type gas as in the case of the first stage described above. It is introduced into an airbag provided adjacent to the vessel 1A to inflate and deploy the airbag.

Next, as shown in FIG. 6, in the third stage after a predetermined time has elapsed from the time when the second igniter 42 is operated, the fragile portion 46b1 provided in the second cover portion 46b of the cover member 46 Cleavage occurs. This cleavage occurs when the pressure in the second combustion chamber S2 increases to a considerable extent due to the pressure increase in the second combustion chamber S2 caused by the combustion of the second gas generating agent 52.

That is, as described above, the fragile portion 46b1 is a portion of the partition portion 44 composed of the partition wall member 45 and the cover member 46, which is configured to have the weakest mechanical strength, and the fragile portion 46b1 has a cleavage pressure (that is, the cleavage is By appropriately setting the pressure at the time of generation), the cover member 46 can be cleaved at a desired timing.

Due to the cleavage of the fragile portion 46b1, in the third stage, the first combustion chamber S1 and the second combustion chamber S2 have an opening 45c provided in the top wall portion 45a of the partition wall member 45 and the top of the partition wall member 45. Through the space between the wall portion 45a and the first covering portion 46a of the cover member 46, and the open portion (that is, the portion where the fragile portion 46b1 was provided) of the second covering portion 46b of the cover member 46. It will be in a state of communication. Along with this, the gas generated in the second combustion chamber S2 is introduced into the first combustion chamber S1 via these portions (see arrow AR3).

The gas generated in the second combustion chamber S2, passing through the partition 44 and introduced into the first combustion chamber S1 then passes through the inside of the filter 70, and at that time, heat is taken away by the filter 70 and cooled. At the same time, the slag contained in the gas is removed by the filter 70 and flows into the gas discharge chamber S3, and then is ejected toward the outside of the housing through the plurality of gas outlets 24 (arrow AR1). reference).

In the third stage, the gas ejected from the plurality of gas outlets 24 to the outside of the disc-type gas generator 1A is the same as in the cases of the first and second stages described above. It is introduced inside an airbag provided adjacent to 1A to inflate and deploy the airbag.

After that, the first gas generator 51 housed in the first combustion chamber S1 and the second gas generator 52 housed in the second combustion chamber S2 are all burned out, so that the disk-type gas generator 1A operates. Is completed.

In the disc-type gas generator 1A according to the present embodiment described above, as described above, the partition portion 44 as a pressure bulkhead that separates the first combustion chamber S1 and the second combustion chamber S2 is provided as a top plate portion. The partition wall member 45 is provided with an opening 45c that opens toward the top plate portion 21 at the axial end on the 21st side, and the second covering portion 46b that covers the tubular portion 45b of the partition wall member 45. It is composed of a cup-shaped cover member 46 provided with a fragile portion 46b1, and an axial end portion (that is, a fixing portion 45b1) on the bottom plate portion 11 side of the partition wall member 45 is press-fitted into the second holder 41. Therefore, the partition portion 44 is assembled to the bottom plate portion 11.

With this configuration, as described above, when the second gas generating agent 52 is burned, the cover member 46 moves toward the top plate portion 21 and then cleaves into the fragile portion 46b1 of the cover member 46. Can be configured to occur. Therefore, the size of the opening 45c provided in the top wall portion 45a of the partition wall member 45 is reduced so that the internal pressure of the second combustion chamber S2 rises to an appropriate pressure when the second gas generating agent 52 is burned. , The desired gas output will be obtained.

Further, at that time, since the partition wall member 45 has a structure in which the opening 45c is provided at the axial end portion on the top plate portion 21 side, as described above when the second gas generating agent 52 is burned. A large pressure is not applied to the partition member 45 along the axial direction of the housing. Therefore, it is possible to prevent the partition wall member 45 from falling off, and in this respect as well, a desired gas output can be reliably obtained.

Therefore, by using the disc-type gas generator 1A according to the present embodiment, it is possible to obtain a dual-structured disc-type gas generator having a simple configuration in which a desired gas output can be stably obtained. This makes it possible to provide a high-performance dual-structured disk-type gas generator at low cost.

Here, in the disc-type gas generator 1A according to the present embodiment, as shown in FIG. 1, the upper support member 62 arranged at the end of the first combustion chamber S1 on the top plate portion 21 side is , A cup-shaped shape is applied to the boundary portion between the filter 70 and the top plate portion 21, and the axial end portion of the partition wall member constituting the partition portion 44 on the top plate portion 21 side is formed. , It is configured to be located inside the upper support member 62.

In the case of such a configuration, as shown in FIG. 6, when the gas generated in the second combustion chamber S2 is introduced into the first combustion chamber S1 in the third stage described above, the filter 70 is directly introduced. It is possible to prevent the filter 70 from being damaged, which may occur when the high-temperature and high-pressure gas is directly sprayed on the filter at a close distance.

That is, by adopting the above configuration, among the gases ejected from the partition portion 44, the gas ejected toward the position closer to the filter 70 (that is, the gas ejected toward the left side in the drawing). However, the traveling direction is changed by being sprayed onto the upper support member 62, and the gas is sprayed exclusively toward the bottom plate portion 11 side of the lower shell 10. Therefore, it is possible to avoid the gas being directly sprayed onto the filter 70, and it is possible to prevent the filter 70 from being damaged.

Further, with reference to FIG. 5, in the disc-type gas generator 1A according to the present embodiment, the bottom plate portion 11 and the top plate portion during operation of the disc-type gas generator 1A allow the cover member 46 to move. The increase in the distance between the top plate portion 21 and the first covering portion 46a of the cover member 46 due to the deformation of the 21 is included. Therefore, in the state before the operation of the disc type gas generator 1A (that is, the state shown in FIG. 1), the first covering portion 46a is separated from the upper support member 62 addressed to the top plate portion 21. It may be positioned or may be in contact with the upper support member 62.

FIG. 7 is an exploded perspective view of a partition portion according to another configuration example of the disc type gas generator according to the present embodiment. The partition wall member 45 of the partition portion 44 provided in the disc-type gas generator 1A described above is formed by providing a single opening 45c in the central portion of the top wall portion 45a. The disk-type gas generator 1A'is provided with a partition member 45' having a shape as shown in FIG. 8 instead.

That is, with reference to FIG. 7, the partition wall member 45'is formed by providing a plurality of openings 45c on the top wall portion 45a, and these plurality of openings 45c are a series of points along the circumferential direction. It is provided in a double shape and in the radial direction. Each of the plurality of openings 45c is provided so as to penetrate the top wall portion 45a along the thickness direction of the top wall portion 45a, and after the cover member 46 is assembled, the plurality of openings 45c are provided. Both are covered by the first covering portion 46a of the cover member 46.

Even when the disk-type gas generator 1A'configured in this way is used, the same effect as the above-mentioned effect can be obtained, and a dual structure having a simple configuration in which the desired gas output can be stably obtained It can be a disc type gas generator.

(Embodiment 2)
FIG. 8 is a schematic cross-sectional view of the disc type gas generator according to the second embodiment, and FIG. 9 is an exploded perspective view showing an assembled structure of the partition portion shown in FIG. First, the configuration of the disc-type gas generator 1B according to the present embodiment will be described with reference to FIGS. 8 to 9.

As shown in FIGS. 8 and 9, the disc-type gas generator 1B according to the present embodiment has a partition wall member 45 and a cover member when compared with the disc-type gas generator 1A according to the above-described first embodiment. There is a difference in the configuration of the partition portion 44 including 46.

Specifically, the partition wall member 45 has a cylindrical shape in which the end portion on the bottom plate portion 11 side and the end portion on the top plate portion 21 side are open, and the disk-type gas according to the first embodiment described above. The top wall portion 45a (see FIG. 1 and the like) of the partition wall member 45 of the generator 1A is not provided. As a result, the partition wall member 45 is composed of only the tubular portion 45b, and the opening end located at the axial end portion of the tubular portion 45b on the top plate portion 21 side causes the partition wall member 45 to be on the top plate portion 21 side. An opening 45c that opens toward is defined.

On the other hand, the cover member 46 has a disk-shaped first covering portion 46a that constitutes a closed end of the partition portion 44 by covering the opening 45c provided at the axial end portion of the partition wall member 45 on the top plate portion 21 side. A cylindrical second covering portion 46b that covers the outer peripheral surface of the partition wall member 45 near the top plate portion 21 by extending from the peripheral edge of the first covering portion 46a toward the bottom plate portion 11 side. Includes.

Here, as in the case of the first embodiment described above, the first covering portion 46a of the cover member 46 is composed of only the inseparable portion, and the second covering portion 46b of the cover member 46 Is composed of a fissure part and an inseparable part. On the other hand, the openable portions (that is, the fragile portions 46b1 shown in the drawing) provided in the second covering portion 46b are scattered along the circumferential direction of the partition wall member 45, unlike the case of the first embodiment described above. A plurality of windows are provided so as to do so. All of these plurality of fragile portions 46b1 are provided in the second covering portion 46b of the portion adjacent to the first covering portion 46a.

10 and 11 are schematic views showing the second and third stages of the operation of the disc type gas generator according to the present embodiment, respectively. Next, the operation of the disc-type gas generator 1B according to the present embodiment will be described with reference to FIGS. 10 and 11.

When a vehicle equipped with the disc type gas generator 1B collides, the collision is detected by a collision detection means separately provided in the vehicle, and based on this, electricity is received from a control unit separately provided in the vehicle. First, the first igniter 32 operates.

The operation in the first stage in which the first igniter 32 is operated is basically the same as that in the first embodiment described above. Therefore, in the first stage, the cover member 46 is pressed against the partition wall member 45 due to the pressure increase in the first combustion chamber S1 caused by the combustion of the first gas generating agent 51. In the first stage, the first combustion chamber S1 and the second combustion chamber S2 are not in a state of communication with each other, and the first gas generating agent 51 is burned to the second gas generating agent 52 whose combustion has not yet started. Will no longer be affected.

Next, at a timing delayed by a predetermined time from the operation of the first igniter 32 described above, the second igniter 42 operates by receiving the energization from the control unit described above.

As shown in FIG. 10, in the second stage in which the second igniter 42 is operated, the igniter filled in the ignition portion 42b of the second igniter 42 is ignited by being heated by the resistor. The combustion of the explosive causes the ignition unit 42b to explode. As a result, the second gas generating agent 52 contained in the second combustion chamber S2 is sequentially ignited to start combustion.

At that time, pressure is applied to the cover member 46 assembled to the partition wall member 45 due to the pressure increase in the second combustion chamber S2 caused by the combustion of the second gas generating agent 52. As a result, the cover member 46 moves toward the top plate portion 21 side of the upper shell 20 as a whole, and then stops by contacting the top plate portion 21 via the upper support member 62.

More specifically, the gas generated in the second combustion chamber S2 is sprayed toward the first covering portion 46a of the cover member 46 through the opening 45c provided in the partition wall member 45 (see arrow AR2). .. As a result, pressure acts mainly on the first covering portion 46a in the direction along the axial direction of the housing, and based on this, the cover member 46 moves toward the top plate portion 21 side. At this time, the cover member 46 is maintained in a state in which the inner peripheral surface of the second covering portion 46b is substantially in close contact with the outer peripheral surface of the tubular portion 45b of the partition wall member 45, and the entire cover member 46 is the top plate portion of the upper shell 20. It will move toward the 21 side.

At this time, in the present embodiment, since the partition wall member 45 does not have the top wall portion 45a (see FIG. 1 and the like) as described above, the partition wall member 45 is basically provided along the axial direction of the housing. As a result, the partition wall member 45 can be prevented from moving toward the top plate portion 21 side.

After the cover member 46 is stopped, of the second cover portion 46b of the cover member 46, the end portion on the top plate portion 21 side provided with the plurality of fragile portions 46b1 is the top plate portion 21 of the partition wall member 45. It faces the second combustion chamber S2 at the side position. Therefore, each of the plurality of fragile portions 46b1 faces both the first combustion chamber S1 and the second combustion chamber S2.

Next, as shown in FIG. 11, in the third stage after a predetermined time has elapsed from the time when the second igniter 42 is operated, a plurality of fragile portions provided in the second cover portion 46b of the cover member 46. Cleavage occurs at 46b1. Here, in the present embodiment, a plurality of window-shaped openings are formed in the side wall portion of the partition portion 44 by cleaving the plurality of fragile portions 46b1. It should be noted that this cleavage occurs when the pressure in the second combustion chamber S2 increases to a considerable extent due to the pressure increase in the second combustion chamber S2 caused by the combustion of the second gas generating agent 52.

Due to the cleavage of the plurality of fragile portions 46b1, in the third stage, the first combustion chamber S1 and the second combustion chamber S2 are the cleaved portions (that is, a plurality of) of the second covering portions 46b of the cover member 46. It is in a state of being communicated through the portion where the fragile portion 46b1 is provided). Along with this, the gas generated in the second combustion chamber S2 is introduced into the first combustion chamber S1 via the portion (see arrow AR3).

After that, the first gas generator 51 housed in the first combustion chamber S1 and the second gas generator 52 housed in the second combustion chamber S2 are all burned out, so that the disk type gas generator 1B operates. Is completed.

In the disc-type gas generator 1B according to the present embodiment described above, as described above, the partition portion 44 as a pressure bulkhead that separates the first combustion chamber S1 and the second combustion chamber S2 is provided as a top plate portion. The partition wall member 45 is provided with an opening 45c that opens toward the top plate 21 side at the axial end on the 21st side, and the second covering portion 46b that covers the tubular portion 45b of the partition wall member 45. It is composed of a cup-shaped cover member 46 provided with a fragile portion 46b1, and an axial end portion (that is, a fixing portion 45b1) on the bottom plate portion 11 side of the partition wall member 45 is press-fitted into the second holder 41. Therefore, the partition portion 44 is assembled to the bottom plate portion 11.

With this configuration, as described above, when the second gas generating agent 52 is burned, the cover member 46 moves toward the top plate portion 21 and then cleaves into the fragile portion 46b1 of the cover member 46. Can be configured to occur. Therefore, the size of the fragile portion 46b1 provided in the second covering portion 46b of the cover member 46 is reduced so that the internal pressure of the second combustion chamber S2 rises to an appropriate pressure when the second gas generating agent 52 is burned. As a result, the desired gas output can be obtained.

Further, at that time, since the partition wall member 45 has a structure in which the opening 45c is provided at the axial end portion on the top plate portion 21 side, as described above when the second gas generating agent 52 is burned. Basically, no pressure is applied to the partition member 45 along the axial direction of the housing. Therefore, it is possible to prevent the partition wall member 45 from falling off, and in this respect as well, a desired gas output can be reliably obtained.

Therefore, by using the disc-type gas generator 1B according to the present embodiment, it is possible to obtain a dual-structured disc-type gas generator having a simple configuration in which a desired gas output can be stably obtained. This makes it possible to provide a high-performance dual-structured disk-type gas generator at low cost.

(Other forms, etc.)
In the above-described first and second embodiments of the present invention, the first igniter and the second igniter are energized at different timings, so that the second igniter is delayed from the operation timing of the first igniter. Although the case where they are configured to operate at the same time has been described as an example, they may be configured to operate at the same timing by being energized at the same timing. Further, even when the first igniter and the second igniter are energized at the same timing, the second igniter is provided by providing a delaying agent for delaying the ignition of the igniter in the ignition portion of the second igniter. The time required from energization to ignition of the igniter is extended, so that the first igniter and the second igniter are energized at the same timing, and the timing of the start of combustion of the second gas generating agent is set to the first. It may be configured to be delayed from the timing of starting combustion of the gas generating agent.

Further, in the above-described first and second embodiments of the present invention, the case where only the gas generating agent is filled in the second combustion chamber has been described as an example, but the second combustion chamber is added to the gas generating agent. It may contain a flame-retardant.

Further, in the above-described first and second embodiments of the present invention, the first igniter and the second igniter are configured to be assembled to the bottom plate portion of the housing via the first metal holder and the second holder, respectively. Although the above-mentioned case has been described as an example, both the first igniter and the second igniter may be configured to be assembled to the bottom plate portion of the housing by so-called insert molding. In that case, the disc-type gas generator will have a first holding portion and a second holding portion made of a resin molded portion in place of the first holder and the second holder described above, and will have the first igniter and the second holding portion. The second igniter will be assembled to the bottom plate portion of the housing via the first holding portion and the second holding portion, respectively.

Specifically, the first holding portion can be formed by injection molding using a mold, and a fluid resin material is poured so as to fill the space between the lower shell and the first igniter. Can be provided by solidifying. More specifically, the above-mentioned fluid resin material is reached from a part of the inner surface to a part of the outer surface of the bottom plate portion via the first opening provided in the bottom plate portion of the lower shell. By adhering it to the bottom plate portion and also adhering it to the base portion of the first igniter and solidifying the fluid resin material in this state, the first igniter is attached to the bottom plate portion of the housing via the first holding portion. Can be assembled to.

As a result, the first opening is embedded by the first holding portion, and the sealing property in the portion is ensured by the first holding portion, so that the airtightness of the space inside the housing can be ensured. The terminal pin of the first igniter may be configured so that a part thereof penetrates the first holding portion and is pulled out to the outside. Further, in this case, for example, if the open end of the cup body is extrapolated to the first holding portion to fix the cup body to the first holding portion by press fitting or the like, the explosive is ignited by the first igniter. It can also be arranged so as to face the part.

Further, the second holding portion can also be formed by injection molding using a mold like the first holding portion, and is a fluid resin so as to fill the space between the lower shell and the second igniter. It can be provided by pouring a material and solidifying it. More specifically, the above-mentioned fluid resin material is spread from a part of the inner surface to a part of the outer surface of the bottom plate portion via the second opening provided in the bottom plate portion of the lower shell. By adhering it to the bottom plate portion and also adhering it to the base portion of the second igniter and solidifying the fluid resin material in this state, the second igniter is attached to the bottom plate portion of the housing via the second holding portion. Can be assembled to.

As a result, the second opening is embedded by the second holding portion, and the sealing property in the portion is ensured by the second holding portion, so that the airtightness of the space inside the housing can be ensured. The terminal pin of the second igniter may be configured so that a part thereof penetrates the second holding portion and is pulled out to the outside. Further, in this case, for example, the partition wall member may be fixed to the second holding portion by press fitting or the like by extrapolating the open end of the bottomed substantially cylindrical partition wall member to the second holding portion, or the partition wall member may be attached to the bottom plate. If welding is performed on the portion, the second gas generating agent may be arranged so as to face the ignition portion of the second igniter.

Here, if the portion of the lower shell provided with the first opening and the second opening is projected in a tubular shape toward the inside of the housing, the first holding portion, the second holding portion, and the bottom plate portion are formed. By increasing the bonding area between the housing and the housing, the joint strength thereof can be increased, and a space for forming the female connector portion inside the tubular bent portion of the housing can be secured. In that case, the cup body or the partition wall member can be press-fitted into the tubular portion of the housing.

As a raw material for the first holding portion and the second holding portion formed by injection molding, a resin material having excellent heat resistance, durability, corrosion resistance and the like after curing is preferably selected and used. In that case, it is not limited to the thermosetting resin represented by epoxy resin and the like, but is represented by polybutylene terephthalate resin, polyethylene terephthalate resin, polyamide resin (for example, nylon 6 and nylon 66), polypropylene sulfide resin, polypropylene oxide resin and the like. It is also possible to use a thermoplastic resin. When these thermoplastic resins are selected as raw materials, it is preferable to include glass fibers or the like as a filler in these resin materials in order to secure the mechanical strength of the first holding portion and the second holding portion after molding. However, if sufficient mechanical strength can be ensured only with the thermoplastic resin, it is not necessary to add the filler as described above.

Further, the above-mentioned injection molding is performed using a lower shell having an adhesive layer provided in advance at a predetermined position on the surface of the bottom plate portion of the portion to be covered by the first holding portion and the second holding portion. May be good. The adhesive layer can be formed by applying an adhesive to a predetermined position of the bottom plate portion in advance and curing the adhesive layer.

In this way, the cured adhesive layer is located between the bottom plate portion and the first holding portion and the second holding portion, so that the first holding portion and the second holding portion made of the resin molded portion are formed. It becomes possible to fix it to the bottom plate more firmly. Therefore, if the adhesive layer is provided in an annular shape along the circumferential direction so as to surround the first opening and the second opening provided in the bottom plate portion, higher sealing performance can be ensured in the portion. You can also.

Here, as the adhesive to be applied to the bottom plate portion in advance, an adhesive containing a resin material having excellent heat resistance, durability, corrosion resistance and the like as a raw material after curing is preferably used, for example, a cyanoacrylate-based resin. And those containing silicone resin as a raw material are particularly preferably used. In addition to the above-mentioned resin materials, phenolic resin, epoxy resin, melamine resin, urea resin, polyester resin, alkyd resin, polyurethane resin, polyimide resin, polyethylene resin, polypropylene resin, etc. Polyvinyl chloride resin, polystyrene resin, polyvinyl acetate resin, polytetrafluoroethylene resin, acrylonitrile butadiene styrene resin, acrylonitrile styrene resin, acrylic resin, polyamide resin, polyacetal resin, polycarbonate resin, Polyphenylene ether resin, polybutylene terephthalate resin, polyethylene terephthalate resin, polyolefin resin, polyphenylene sulfide resin, polysulfone resin, polyether sulfone resin, polyallylate resin, polyether ether ketone resin , Polyamidoimide-based resin, liquid crystal polymer, styrene-based rubber, olefin-based rubber and the like as raw materials can be used as the above-mentioned adhesive.

One of the first igniter and the second igniter is fixed to the housing via a metal holder, and the other of the first igniter and the second igniter is housed via a holding portion made of a resin molded portion. It may be fixed to.

In addition, as in the case of the first and second embodiments of the present invention described above, the base of the first igniter assembly and the second igniter assembly is formed by the first holder and the second holder, respectively. The first igniter assembly is formed by joining the first holder and the first igniter at the resin molding part, and the second holder and the second igniter are joined at the resin molding part. As a result, the second igniter assembly may be formed, and the first holder and the second holder may be joined to the bottom plate portion by welding or the like.

Furthermore, the characteristic configurations shown in the first and second embodiments of the present invention described above can be combined with each other as long as they do not deviate from the gist of the present invention.

As described above, the above-described embodiment disclosed this time is an example in all respects and is not limiting. The technical scope of the present invention is defined by the scope of claims and includes all modifications within the meaning and scope equivalent to the description of the scope of claims.

1A, 1A', 1B disk type gas generator, 10 lower shell, 11 bottom plate, 11a 1st opening, 11b 2nd opening, 12 peripheral wall, 20 upper shell, 21 top plate, 22 peripheral wall , 23 Flange, 24 Gas spout, 25 Seal tape, 30 1st igniter assembly, 31 1st holder, 31a Upper recess, 31b Lower recess, 31c through hole, 31d, 31e caulking, 32 1st ignition Vessel, 32a base, 32b ignition part, 32c terminal pin, 33 first seal member, 34 cup body, 34a top wall part, 34b side wall part, 34c flange part, 35 fire chamber, 36 fire extinguishing agent, 40 second ignition Assembly, 41 2nd holder, 41a upper recess, 41b lower recess, 41c through hole, 41d caulking part, 42 2nd igniter, 42a base, 42b ignition part, 42c terminal pin, 43 2nd seal member, 44 partition Part, 45 partition wall member, 45a top wall part, 45b tubular part, 45b1 fixing part, 45c opening, 46 cover member, 46a first covering part, 46b second covering part, 46b1 fragile part, 51 first gas generating agent , 52 Second gas generator, 61 Lower support member, 62 Upper support member, 63 Cushion material, 70 Filter, S1 First combustion chamber, S2 Second combustion chamber, S3 Gas discharge chamber.

Claims (6)

A housing including a peripheral wall portion provided with a gas outlet, a top plate portion that closes one end of the peripheral wall portion in the axial direction, and a bottom plate portion that closes the other end of the peripheral wall portion in the axial direction.
A tubular filter housed inside the housing so that the outer peripheral surface faces the inner peripheral surface of the peripheral wall portion.
A first combustion chamber in which a first gas generating agent is housed in the space inside the filter by forming a cup-like shape as a whole having a closed end on the top plate portion side and assembling to the bottom plate portion. And a partition that divides the second combustion chamber into which the second gas generating agent is housed,
A first igniter assembled to the bottom plate portion so as to face the first combustion chamber, which is a space outside the partition portion.
A second igniter assembled to the bottom plate portion so as to face the second combustion chamber, which is a space inside the partition portion, and
It is provided with a holder for assembling the second igniter to the bottom plate portion by being fixed to the bottom plate portion and holding the second igniter.
The partition portion has a partition wall member provided with a tubular portion facing the inner peripheral surface of the filter, and a cover member assembled to the partition wall member.
At the axial end of the partition member on the top plate side, an opening that opens toward the top plate is provided.
The cover member includes a first cover portion that constitutes the closed end by covering the axial end portion of the partition wall member on the top plate portion side, and the cover member along the axial direction of the tubular portion from the first cover portion. By extending it, it forms a cup-like shape including a second covering portion that adheres to and covers the outer peripheral surface of the tubular portion.
The holder is arranged so as to project from the bottom plate portion toward the space inside the filter.
By press-fitting the axial end portion of the partition wall member on the bottom plate portion side into the holder, the partition portion is assembled to the bottom plate portion via the holder.
The cover member includes a fragile portion that can be cleaved by an increase in the internal pressure of the second combustion chamber and a non-fragile portion that does not cleave by an increase in the internal pressure of the second combustion chamber. Including
The first covering portion comprises only the intractable portion
The second covering portion is composed of the openable portion and the inaccessible portion.
When the second igniter is operating, the first covering portion consisting of only the non-cleavable portion is opened due to an increase in the internal pressure of the second combustion chamber caused by the combustion of the second gas generating agent. By receiving the internal pressure of the second combustion chamber through the portion, the cover member moves toward the top plate portion while maintaining the state in which the second covering portion is in close contact with the tubular portion. Along with this, the openable portion of the second covering portion is exposed so as to face the second combustion chamber at a position closer to the top plate portion than the partition wall member, so that the internal pressure of the second combustion chamber is increased. A gas generator that receives and cleaves, thereby introducing the gas generated in the second combustion chamber into the first combustion chamber. The partition wall member has a cup-like shape having a top wall portion located at an axial end portion of the tubular portion on the top plate portion side.
The gas generator according to claim 1, wherein the opening is provided in the top wall portion. The gas generator according to claim 1 or 2, wherein the fissure portion is provided in an annular shape on the second covering portion so as to extend along the circumferential direction of the partition wall member. The gas generator according to any one of claims 1 to 3, wherein the crackable portion is provided in the second covering portion of a portion adjacent to the first covering portion. The gas generator according to any one of claims 1 to 4, wherein the movement of the cover member during operation of the second igniter is restricted by the top plate portion. When the first igniter is operating, the top plate portion is deformed so as to bulge outward due to an increase in the internal pressure of the first combustion chamber caused by the combustion of the first gas generating agent. As a result, the distance between the top plate portion and the first cover portion is increased, and the increase in this distance is included in the movement margin of the cover member when the second igniter is operated. The gas generator according to claim 5.

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