JP4860809B2 - Gas generator for airbag and airbag device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a gas generator for an air bag and an air bag device using the same.
[0002]
[Prior art and problems to be solved by the invention]
Airbag systems installed in various vehicles including automobiles support passengers with airbags (bags) that are rapidly inflated by gas when the vehicle collides at high speed. The purpose is to prevent injuries and the like by crashing into hard parts inside the vehicle such as the steering wheel and front glass. Such an airbag system is usually composed of a gas generator that is activated by a vehicle collision to release gas and an airbag that is inflated by introducing the gas.
[0003]
Such an airbag system can safely protect the occupant even if the physique of the occupant (for example, a person with a high or low seating height, an adult or a child, etc.), or the riding posture (for example, the posture clinging to the steering wheel) is different. It is desirable that it can be restrained. Therefore, conventionally, an air bag system has been proposed that operates in the initial stage of operation with as little impact as possible to the occupant. Such a gas generator is disclosed in Japanese Patent Laid-Open No. 8-207696, US Pat. No. 4,998,751, and US Pat. No. 4,950,458. In Japanese Patent Laid-Open No. 8-207696, two types of igniters are used. A gas generator that ignites a capsule of a gas generating agent and generates gas in two stages is provided with two combustion chambers in U.S. Pat.No. 4,998,751 and U.S. Pat.No. 4,950,458 to regulate the operation function of the gas generator. Thus, gas generators that generate gas in two stages by the spread of the gas generating agent have been proposed.
[0004]
Thus, the gas generator with two combustion chambers is excellent in that it can generate gas in two stages, but in that case, it prevents the malfunction and makes the product safe and reliable. Therefore, it is important to prevent the gas generating agents in the other combustion chambers from igniting and burning by igniting and burning the gas generating agents in one combustion chamber.
[0005]
Therefore, the present invention secures safety and reliability in a gas generator provided with two combustion chambers, and also provides a gas generator for an airbag that can stably and effectively express the feature that gas can be generated in two stages. An object of the present invention is to provide an airbag apparatus using the same.
[0006]
[Means for Solving the Problems]
The present invention provides, as one solution, an ignition means that operates by impact in a housing having a gas discharge port, and a gas generation means that generates combustion gas that is ignited and burned by the ignition means to inflate an airbag. A gas generator for an air bag that is contained in the housing, wherein two combustion chambers for containing gas generating means are provided in the housing, and the combustion chambers can communicate with each other. A communication hole is provided, and the communication hole has a tensile strength of 15 kg / mm. ² Thus, a gas generator for an air bag is provided which is closed with a thin metal plate having a thickness of 10 to 200 μm.
[0007]
Further, according to the present invention, in the above-described gas generator for an air bag, two combustion chambers for accommodating the gas generating means are provided concentrically adjacent to each other in the radial direction of the housing, and the combustion chambers communicate with each other. A gas generator for an air bag having a communication hole that can be made can be provided.
[0008]
Furthermore, in the gas generator for an air bag according to the present invention, two combustion chambers for housing the gas generating means are provided concentrically adjacent to each other in the radial direction of the housing, and the respective combustion chambers can communicate with each other. The inner combustion chamber of the two combustion chambers is provided on the upper space side of the inner cylinder member disposed in the housing, and the ignition means is a lower space of the inner cylinder member. The gas generator for an air bag can be provided in which the upper space and the lower space are defined by a partition wall.
[0009]
Further, the present invention provides, as another solution, an igniting means that is actuated by an impact in a housing having a cylindrical shape whose axial center length is longer than the outermost diameter and having a plurality of gas discharge ports on its peripheral wall. A gas generator for an air bag including a gas generating means for generating combustion gas that is ignited and burned by the ignition means to inflate the air bag. Two combustion chambers for accommodating the means are provided coaxially adjacent to each other in the axial direction and / or radial direction of the housing, and further provided with communication holes that allow the respective combustion chambers to communicate with each other, The communication hole has a tensile strength of 15 kg / mm ² Thus, a gas generator for an air bag is provided which is closed with a thin metal plate having a thickness of 10 to 200 μm.
[0010]
As described above, the communication holes that allow the combustion chambers to communicate with each other have a tensile strength of 15 kg / mm. ² Or more, preferably 25-60 kg / mm ² As described above, by being closed by a metal thin plate having a thickness of 10 to 200 μm, preferably a metal thin plate having a thickness of 20 to 100 μm (for example, a seal tape), it is accommodated in one combustion chamber by ignition of one igniter. The gas generating means (the gas generating means for the second ignition combustion) accommodated in the other combustion chambers, with the metal plate ruptured by the pressure generated by the combustion of the gas generating means (the gas generating means for the first ignition combustion) Is prevented from burning. The prevention effect described above can be obtained by setting the thickness of the metal thin plate to 10 μm or more. By setting the thickness of the metal thin plate to 200 μm or less, the force when the metal thin plate attached to the curved surface in accordance with the shape of the portion where the communication hole is formed tries to return to the flat shape is the force of the adhesive layer. It can be prevented that it becomes larger and easily peeled off. As a metal thin plate, what consists of aluminum, stainless steel, and copper, for example can be used.
[0011]
The gas generating means is for inflating an airbag that restrains an occupant with combustion gas generated by the combustion. Therefore, even if the ignition means includes a transfer powder that is ignited and burned by the igniter and burns the gas generation means, the combustion gas generated by the combustion of the transfer powder burns the gas generation means. The two can be clearly distinguished in that they are not intended to directly inflate the airbag. Further, the two combustion chambers provided in the housing are chambers exclusively for accommodating the gas generating means, and the ignition means includes a charge transfer agent, and the transfer charge is defined. Even if it is accommodated in an open space (hereinafter referred to as “accommodating chamber”), the explosive charge accommodating chamber and the combustion chamber accommodating the gas generating means can be clearly distinguished.
[0012]
When the ignition means for igniting / combusting the gas generating means includes two or more igniters that are activated by impact, the igniters are aligned with each other in order to facilitate the mounting. It is desirable to be provided in one initiator collar. Further, when the ignition means further includes a propellant that is ignited and burned by the operation of the igniter, the propellant is classified for each igniter, and is ignited independently for each igniter. -It is desirable to form so that the burned flame of the transfer charge corresponding to any one of the igniters does not directly ignite the transfer charge corresponding to the other igniters. As such a structure, for example, each igniter is disposed in an independent igniter housing chamber, and a transfer charge is disposed in the igniter housing chamber, or in each independent combustion chamber, It can be arranged at a place where it can be ignited and burned by the operation of the vessel.
[0013]
As described above, when the transfer charge is divided for each igniter, the gas generating means accommodated in the two combustion chambers are ignited and burned by the flames in which the transfer charges of different sections are burned. That is, according to the operation timing of the igniter, the transfer charge of each section burns, and the gas generation means in each combustion chamber can burn separately, so that the operation performance of the gas generator can be arbitrarily adjusted. it can.
[0014]
Therefore, if the ignition timing is changed for each igniter, it is possible to separately burn the transfer charge divided for each igniter, and accordingly, the ignition / combustion timing of the gas generating means in each combustion chamber can be shifted. Therefore, it is possible to arbitrarily adjust the operation output of the gas generator.
[0015]
Of the two combustion chambers provided in the housing, any one combustion chamber may be provided in the axial direction of the igniter, and the other combustion chamber may be provided in the radial direction of the ignition means. Furthermore, in the case where the operating performance of the gas generator, in particular, the change over time of the gas discharge amount is more characteristically adjusted, the combustion rate, composition, composition ratio or amount of each combustion chamber is different in the two combustion chambers. At least one or more different gas generating means can be accommodated, and they can be ignited and burned independently at an arbitrary timing. Further, it is possible to fill each combustion chamber with gas generating means having different generated gas amounts per unit time.
[0016]
As the gas generating means, it is possible to use an azide-based gas generating agent based on an inorganic azide, for example, sodium azide (sodium azide) that has been widely used, or a non-azide-based gas generating agent that is not based on an inorganic azide. it can. However, in consideration of safety, a non-azide-based gas generant is desirable. Examples of such non-azide-based gas generant compositions include nitrogen-containing organic compounds such as tetrazole, triazole, or metal salts thereof, and alkali metals. Oxygen-containing oxidants such as nitrates as the main component, triaminoguanidine nitrate, carbohydrazide, nitroguanidine, etc. as fuel and nitrogen source, alkali metal or alkaline earth metal nitrate, chlorate, Various compositions such as a composition using perchlorate can be used. In addition, the gas generating means is appropriately selected according to demands such as the combustion rate, non-toxicity, combustion temperature, and decomposition start temperature. When using gas generating means with different combustion rates for each combustion chamber, the composition and composition ratio itself, for example, using an inorganic azide such as sodium azide or a non-azide such as nitroguanidine as the fuel and nitrogen source, etc. In addition to using different gas generating means, the shape of the composition can be changed, such as pellets, wafers, hollow cylinders, disks, single holes or porous bodies, or depending on the size of the molded body, etc. Gas generating means having a changed surface area can be used. In particular, when the shape of the gas generating means is formed in a porous body having a plurality of through-holes, the arrangement of the holes is not particularly limited, but for the stability of the gas generator, the outer end of the molded body is used. An arrangement structure in which the distance between the portion and the center of the hole and the distance between the centers of the holes is substantially equal is desirable. Specifically, for example, in the case of a cylindrical molded body having a circular cross section of the molded body, there are 6 holes having the center of the hole at the apex of an equilateral triangle that is equidistant from each other at the center. A structure in which the holes are arranged is preferable. Similarly, an arrangement in which one hole at the center and 18 holes at the periphery exist can be considered. The number of holes and the arrangement structure are determined by the ease of manufacturing the gas generating agent and the balance between the manufacturing cost and the performance, and are not particularly limited.
[0017]
Of the two combustion chambers, the combustion chamber provided on the outer side in the radial direction can also contain a coolant means for cooling the combustion gas generated by the combustion of the gas generating means on the housing peripheral wall side. . The coolant means is disposed in the housing for the purpose of cooling and / or purifying the combustion gas generated by the combustion of the gas generating means. For example, a conventionally used filter for purifying the combustion gas In addition to using a coolant that cools the generated combustion gas, it is also possible to use a compression-molded laminated wire mesh filter, etc., in which a wire mesh made of appropriate materials is formed into an annular laminate. The laminated wire mesh coolant is preferably formed by forming a flat knitted stainless steel wire mesh into a cylindrical body, and bending one end of the cylindrical body outwardly to form an annular laminated body. Compression molding or forming a flat knitted stainless steel wire mesh into a cylindrical body, pressing this cylindrical body in the radial direction to form a plate body, and then winding the plate body in multiple layers to form a laminate And can be molded by compression molding in a mold. Moreover, it is also possible to have a double structure as a laminated metal mesh body having different inside and outside, and have a function of protecting the coolant means on the inside and a function of preventing the swelling of the coolant means on the outside. In addition, the outer periphery of the coolant means can be supported by an outer layer made of a laminated wire mesh body, a porous cylindrical body, an annular belt body, or the like, whereby the swelling can be suppressed.
[0018]
Also, the combustion gas generated by the combustion of the gas generating means accommodated in the two combustion chambers reaches the gas discharge port through a different flow path for each combustion chamber, and the gas generating means accommodated in one combustion chamber is When the gas generator is not directly ignited by the combustion gas generated in other combustion chambers, the gas generating means in each combustion chamber burns completely independently for each combustion chamber. Therefore, ignition and combustion of the gas generating means accommodated in each combustion chamber can be performed more reliably and independently. As a result, even when the operation timings of the two igniters are considerably shifted, the flame of the gas generating means in one combustion chamber ignited by the igniter that has been initially operated becomes the gas generating means in the other combustion chamber. Is not burned, and a stable operation output can be obtained. Such a gas generator can be performed, for example, by arranging a flow path forming member in a housing to form a flow path, and guiding the combustion gas generated in one combustion chamber to the coolant means as it is.
[0019]
The housing can be formed by forming a diffuser shell having a gas discharge port and a closure shell that forms an accommodation space together with the diffuser shell by casting, forging, pressing, or the like, and joining both shells. Both shells can be joined by various welding methods such as electron beam welding, laser welding, TIG welding, and prosection welding. When the diffuser shell and the closure shell are formed by pressing various steel plates such as a stainless copper plate, both shells can be easily manufactured and the manufacturing cost can be reduced. Further, by forming both shells in a simple and simple cylindrical shape, the press working becomes easy. As for the material of the diffuser shell and the closure shell, a stainless steel plate is desirable, but the steel plate may be nickel-plated.
[0020]
The housing further accommodates ignition means that operates by sensing an impact and ignites and burns the gas generating means. In the gas generator of the present invention, an electric ignition type ignition means that operates by an electric signal (or an operation signal) transmitted from an impact sensor or the like that detects an impact is used as the ignition means. The electric ignition ignition means is an igniter that operates based on an electric signal transmitted from an electric sensor that senses an impact exclusively by an electric mechanism such as a semiconductor acceleration sensor, and ignites and burns by the operation of the igniter. It is composed including a charge transfer agent.
[0021]
The above-described gas generator for an air bag is accommodated in a module case together with an air bag (bag body) that introduces a gas generated by the gas generator and inflates, thereby forming an air bag device. In this airbag device, the gas generator is operated in conjunction with the impact sensor detecting the impact, and the combustion gas is discharged from the gas discharge port of the housing. The combustion gas flows into the air bag, whereby the air bag breaks the module cover and inflates to form a cushion that absorbs an impact between a hard structure in the vehicle and the occupant.
[0022]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, based on the embodiment shown in the drawings, the gas generator for an air bag of the present invention will be described.
“Embodiment 1”
FIG. 1 is a longitudinal sectional view of a first embodiment of a gas generator for an air bag according to the present invention, and has a structure particularly suitable for being arranged on the driver's seat side.
[0023]
In this gas generator, a substantially cylindrical inner cylinder member 4 is disposed in a housing 3 formed by joining a diffuser shell 1 having a gas discharge port and a closure shell 2 that forms an internal housing space together with the diffuser shell. And the outside is used as the first combustion chamber. Further, a notch 6 is provided inside the inner cylinder member, and a substantially flat circular partition wall 7 is disposed in the notch, and the inner cylinder is further divided into two chambers by the partition, A second combustion chamber 5b is formed on the diffuser shell side (upper space side), and an ignition means accommodation chamber 8 is formed on the closure shell side (lower space side). As a result, in this gas generator, the first combustion chamber 5a and the second combustion chamber 5b are provided concentrically in the housing 3 and are adjacent to each other in the radial direction of the housing. In the first and second combustion chambers, gas generating agents (9a, 9b) that burn by the ignition means that operates under impact and generate combustion gas are stored, and in the ignition means storage chamber 8, The ignition means which operates by impact is accommodated. A through hole 10 is provided in the inner cylinder member 4 that defines the first combustion chamber 5 a and the second combustion chamber 5 b, and the through hole is closed by a seal tape 11. However, since the seal tape 11 bursts when the gas generating agent burns, both the combustion chambers can communicate with each other through the through hole 10.
[0024]
The material and thickness of the sealing tape 11 are adjusted so that the gas generating agent 9b in the second combustion chamber 5b is not broken by the combustion of the gas generating agent 9a in the first combustion chamber 5a, but is torn when the gas generating agent 9b in the second combustion chamber 5b burns. There is a need to. In this embodiment, the tensile strength is 54 kg / mm. ² Thus, a stainless steel seal tape having a thickness of 40 μm is used. The through hole 10 has an opening area larger than that of the gas discharge port 26b and does not have a function of controlling the internal pressure in the combustion chamber 5b.
[0025]
The ignition means includes two electric ignition igniters (12a, 12b) that are activated by an activation signal that is output when the sensor senses an impact. The initiator collars 13 are provided with their heads protruding in parallel with each other. By providing two igniters (12a, 12b) in one initiator collar 13 in this way, the two igniters are fixed to the initiator collar 13 and become a single member, which can be assembled to the gas generator. It becomes easy. In particular, in the gas generator shown in this figure, the initiator collar 13 provided with two igniters (12a, 12b) is made to have a size that allows the initiator collar 13 to be inserted into the inner cylinder member 4. After being inserted into 4, the lower end of the inner cylinder member 4 is crimped to fix the initiator collar, so that the igniter can be fixed easily and reliably. Further, when the two igniters (12a, 12b) are arranged on the initiator collar 13, the direction of each igniter can be easily regulated. In the drawing, the two igniters are arranged eccentrically with respect to the central axis of the housing. When the igniters (12a, 12b) are arranged in the same direction, as shown in the rear view of the gas generator of the present embodiment in FIG. 2, the igniters (12a, 12b) and the control unit (see FIG. The lead wire 50 that connects to the other (not shown) can be pulled out in the same direction on the same plane. In FIG. 2, each lead wire 50 is connected to each igniter (12a, 12b) via a connector 50a, and the connectors are arranged in parallel on the same plane. By making this connector L-shaped, the lead wire that transmits an electrical signal (actuation signal) to the igniter can be pulled out in a direction perpendicular to the axial direction of the housing (that is, in the radial direction of the housing). At this time, the lead wire connected to each igniter can be pulled out in the same direction.
[0026]
In this embodiment, a substantially cylindrical separation cylinder is provided so as to surround any one of the igniters 12b (hereinafter referred to as “second igniters”) in the space between the initiator collar 13 and the partition wall 7. 14 is arranged, a first transfer charge storage chamber 15a is defined on the outer side, a second transfer charge storage chamber 15b is defined on the inner side, and an igniter and an ignition means together with the igniter are provided in each storage chamber. Contains explosives to make up. As a result, the charge transfer agent (16a, 16b) that constitutes the ignition means together with the igniter is reliably classified for each igniter (12a, 12b). In the first transfer charge storage chamber 15a, when the transfer charge 16a accommodated therein burns, the seal tape 18 that closes the transfer transfer hole 17 formed in the inner cylinder member 4 bursts and the first combustion is performed. It communicates with chamber 5a. Further, in the second transfer charge storage chamber 15b, when the transfer charge 16b therein burns, the seal tape 20 closing the transfer hole 19 formed in the partition wall 7 is ruptured and communicates with the second combustion chamber 5b. Therefore, when this gas generator is operated, the flame when the first igniter 12a is ignited (actuated) ignites and burns the transfer charge 16a in the storage chamber 15a, and the flame is the inner cylinder. The seven-hole gas generating agent 9a accommodated in the first combustion chamber 5a passing through the heat transfer hole 17 formed in the member 4 and positioned in the radial direction of the accommodating chamber 15a is ignited and burned. The second igniter 12b ignites and burns the second transfer charge 16b in the storage chamber 15b, and the flame passes through the transfer hole 19 provided in the axial direction of the storage chamber 15b and extends its extension. The single-hole gas generating agent 9b accommodated in the second combustion chamber 5b above is ignited and burned. This second combustion chamber 5b The combustion gas generated inside flows through the through hole 10 provided on the diffuser shell 1 side of the inner cylinder member 4 and flows into the first combustion chamber 5a.
[0027]
In particular, in the gas generator shown in FIG. 1, the second igniter 12b and the first igniter 12a may ignite simultaneously in order to stabilize the operation performance, but the former 12b operates before the latter 12a. Never do. That is, the gas generating agent 9b accommodated in the second combustion chamber 5b burns at the same time as or with a delay from the gas generating agent 9a accommodated in the first combustion chamber 5a. When the gas generating agent 9a in the first combustion chamber 5a burns before the second gas generating agent 9b, the seal tape 11 has a predetermined tensile strength and thickness as described above, and therefore the first It is not broken by the combustion of the first gas generant 9a, but only by the combustion of the second gas generant 9b.
[0028]
Further, in the gas generator shown in this figure, the separation cylinder 14 disposed between the initiator collar and the partition wall is disposed on the lower surface of the partition wall 7 and the upper surface of the initiator collar 13 as shown in the enlarged view of the main part of FIG. Holes 21 corresponding to the outer shape of the separation cylinder 14 are provided, and the upper end or the lower end of the separation cylinder 14 is fitted in each hole. By arranging the separation cylinder 14 in this way, the flame of the transfer charge generated in any one of the transfer charge combustion chambers does not directly burn the transfer charge in the other transfer charge storage chambers. The gas generating agent accommodated in the combustion chamber is ignited and burned by a flame in which different types of explosives are burned. That is, normally, when the transfer charge burns in the separation cylinder 14 (that is, in the second transfer charge storage chamber), the pressure of the gas generated by the combustion also causes the separation cylinder to expand in the radial direction. However, by arranging the separation cylinder as shown in FIG. 3, the upper and lower ends of the separation cylinder are surely supported by the peripheral walls of the holes into which the separation cylinders are inserted. Compared with the case where it is sandwiched between the partition wall and the initiator collar, it is possible to more reliably prevent leakage of the transfer gas combustion gas and flame.
[0029]
In the housing 3, a common coolant filter 22 for purifying and cooling the combustion gas generated by the combustion of the gas generating agent (9a, 9b) is disposed, and the inner circumference on the diffuser shell 1 side is disposed. The surface is covered with a short path prevention member 23 so that the combustion gas does not pass between the end surface of the coolant / filter 22 and the diffuser shell 1 ceiling inner surface 28. On the outside of the coolant / filter 22, an outer layer 24 for preventing the filter 22 from expanding due to passage of combustion gas or the like is disposed. The outer layer 24 is formed, for example, using a laminated wire mesh body, or a porous cylindrical member having a plurality of through holes on the peripheral wall surface, or a belt-like restraining layer in which a belt-like member having a predetermined width is formed in an annular shape. You can also. Further, a gap 25 is formed outside the outer layer 24 so that the combustion gas can pass through the entire surface of the filter 22. The gas outlet 26 formed in the diffuser shell is closed with a seal tape 27 to prevent the outside air from entering. The seal tape 27 is ruptured when gas is released. The purpose of the seal tape 27 is to protect the gas generating agent from external moisture and does not affect the performance adjustment such as the combustion internal pressure at all.
[0030]
In the gas generator formed as described above, when the first igniter 12a disposed in the ignition means accommodating chamber 8 and outside the separation cylinder 14 is activated, the first explosive charge accommodating chamber 15a The flame transfer agent 16a accommodated in the cylinder is ignited and burned, and the flame passes through the flame transfer hole 17 of the inner cylinder member 4 and has a porous cylindrical first having seven holes accommodated in the first combustion chamber 5a. The gas generating agent 9a is burned. Further, when the second igniter 12b surrounded by the separation cylinder 14 is operated in the same or delayed manner as the first igniter 12a, the transfer charge 16b stored in the second transfer charge storage chamber 15b is ignited. Combusting, and the flame ignites and burns the single-hole cylindrical second gas generating agent 9b accommodated in the second combustion chamber 5b. As a result, the ignition timing of the two igniters (12a, 12b) is adjusted, that is, the second igniter is operated after the first igniter is operated, or the first igniter and the second igniter are operated. The output form (operation performance) of the gas generator can be adjusted arbitrarily depending on whether the two are operated at the same time. In various situations such as the vehicle speed and environmental temperature at the time of collision, It is possible to optimize the deployment of the air bag at the maximum. In particular, in the gas generator shown in this figure, gas generating agents (9a, 9b) having different shapes are used for the respective combustion chambers (5a, 5b), and the first combustion chamber 5a has a porous cylindrical second. One gas generating agent 9a is accommodated in the second combustion chamber 5b, and a single-hole cylindrical second gas generating agent 9b is accommodated therein. Further, the amount of the gas generating agent accommodated in each combustion chamber (5a, 5b) is also different, 35 g in the first combustion chamber 5a, 6g gas generating agent (9a, 9b in the second combustion chamber 5b). ) Are housed. As a result, in this gas generator, it is possible to adjust the output form more accurately. Of course, the shape, composition, composition ratio, amount, and the like of the gas generating agent can be appropriately changed in order to obtain a desired output form.
“Embodiment 2”
FIG. 2 is a longitudinal sectional view showing another embodiment of the gas generator for an air bag of the present invention. This gas generator has a structure particularly suitable for being arranged on the passenger seat side.
[0031]
The gas generator shown in this figure has a cylindrical shape whose axial center length is longer than the outermost diameter, and in a housing 103 having a plurality of gas discharge ports on its peripheral wall, ignition means that operates by impact, A gas generating agent (9a, 9b) that generates a combustion gas that is ignited and burned by the ignition means to inflate the airbag; and a coolant that cools and / or purifies the combustion gas generated by the combustion of the gas generating agent. The filter 122 is contained. The two combustion chambers (105a, 105b) provided in the housing 103 are formed as a cylindrical combustion chamber 105a and an annular combustion chamber 105b, and are provided coaxially adjacent to each other in the axial direction of the housing 103. In addition, a communication hole 110 is provided that allows the combustion chambers (105a, 105b) to communicate with each other.
[0032]
The gas generator shown in the present embodiment has a shape that is long in the axial direction because the housing has a cylindrical shape that is long in the axial direction. As described above, the two combustion chambers (105a, 105b) shall be a combination of a cylindrical combustion chamber 105a and an annular combustion chamber 105b, which are provided adjacent to each other on the same axis so that both combustion chambers can communicate with each other. As a result, the operation output of the gas generator and the timing of the output increase can be adjusted arbitrarily, but the gas generator has a simple structure and is easy to manufacture.
[0033]
The ignition means includes two or more igniters that are activated by impact, and each igniter (12a, 12b) is provided in parallel with each other on one initiator collar 113. It will be easy. Further, each igniter (12a, 12b) assembled in the one initiator collar 113 and accommodated in the housing is eccentric with respect to the shaft of the housing.
[0034]
In addition, a substantially cylindrical coolant / filter 122 is disposed in the housing 103 so as to face the inner peripheral surface of the housing in which a plurality of gas discharge ports 126 are formed, and between the filter 122 and the inner periphery of the housing. A predetermined gap 125 is secured in the. A first combustion chamber 105a is defined adjacent to a space in which the coolant / filter 122 is accommodated, and an ignition means including two igniters (12a, 12b) is provided in the first combustion chamber 105a. It is coaxially arranged adjacent to the combustion chamber 105a. Since the annular second combustion chamber 105b is defined in the radial direction of the ignition means, the first combustion chamber 105a and the second combustion chamber 105b are adjacent to each other in the axial direction of the housing 103. Will be provided. The first and second combustion chambers are filled with different gas generating agents (9a, 9b). In the gas generator shown in this figure, the first combustion chamber 105a has a porous cylindrical shape. The first gas generating agent 9a and the second combustion chamber 105b contain a single-hole cylindrical second gas generating agent 9b, respectively.
[0035]
The ignition means is configured to ignite and burn by the operation of the igniter (12a, 12b), and includes a charge generating agent that ignites the gas generating agent (105a, 105b) by the flame. Each igniter is defined, and each igniter ignites and burns independently. The space in which the transfer charge defined for each igniter is stored is defined by a cylindrical member, and the first transfer charge storage chamber 115a in which the first transfer charge 116a is stored includes ignition means. And the first combustion chamber 105a, the first transfer chamber 119 communicates with the first combustion chamber 105a at the transfer hole 119 of the partition wall 107 disposed between the first combustion chamber 105a and the second transfer agent storage chamber 115b. Is in communication with the second combustion chamber 105b through a heat transfer hole 117 formed in the cylindrical member 104 defining the storage chamber 115b.
[0036]
The first combustion chamber 105a and the second combustion chamber 105b are such that the seal tape 11 that closes the through hole 110 formed in the partition wall 107 is ruptured by the combustion of the second gas generating agent 9b. As a result, the through-hole 110 communicates. In this embodiment, the tensile strength is 54 kg / mm. ² Thus, a stainless steel seal tape having a thickness of 40 μm is used. Since the seal tape 11 has a predetermined tensile strength and thickness, it is not broken by the combustion of the first gas generating agent 9a, but is broken only by the combustion of the second gas generating agent 9b.
[0037]
In the gas generator shown in this figure, when the first igniter 12a is activated, the transfer charge 116a in the first transfer charge storage chamber 115a is ignited and burned, and the flame passes through the transfer hole 119 of the partition wall member 107. Thus, the gas generating agent 9a disposed in the first combustion chamber 105a is ignited and burned to generate combustion gas. The combustion gas is purified and cooled while passing through the coolant / filter 122 and is discharged from the gas discharge port 126. On the other hand, when the second igniter 12b is activated, the transfer charge 116b in the second transfer charge storage chamber 115b is ignited and burned, and the flame generates and burns the gas generating agent 9b in the second combustion chamber 105b. Let The combustion gas generated in the second combustion chamber 105b passes through the first combustion chamber 105a through the through hole 110 of the partition wall 107, and is purified and cooled while passing through the coolant / filter 122, Released from the gas outlet 126. The combustion gas generated by the combustion of the first gas generating agent and the combustion gas generated by the combustion of the second combustion gas are both purified and cooled while passing through the same coolant / filter 122. In this embodiment as well, the gas outlet 126 is closed by the seal tape 127. The seal tape 127 is intended to protect the gas generating agent from external moisture, and is ruptured by the combustion gas generated by the combustion of the gas generating agent so that the combustion gas can be released. Therefore, the seal tape 127 does not control the combustion performance (combustion internal pressure) of the gas generating agent. Further, the heat transfer holes 119 are closed by the seal tape 20, and the heat transfer holes 117 are closed by the seal tape 18, respectively.
[0038]
The defining member 160 that defines the first combustion chamber 105b and the space in which the coolant / filter 122 is accommodated is provided with a communication hole 161 that communicates the two chambers. The combustion gas generated in the combustion chamber (105a, 105b) reaches the accommodation space of the coolant / filter 122 through the communication hole 161. In this embodiment, the defining member 160 is formed with a communication hole 161 having substantially the same size as the inner diameter of the coolant / filter 122. The communication hole 161 is provided with a metal mesh 162 so that the gas generating agent 9a in the first combustion chamber 105a does not move to the space side in which the coolant / filter 122 is accommodated during the combustion. Yes. The wire mesh 162 is a mesh of a size that can prevent the movement of the first gas generating agent 9a during combustion, and it does not have any ventilation resistance that controls the combustion performance. Absent.
[0039]
As described above, also in the gas generator of this aspect, the gas generating agent (9a, 9b) accommodated in each combustion chamber (105a, 105b) adjusts the operation timing of the two igniters (12a, 12b). By doing so, it is ignited and burned independently, and the output form (operation performance) of the gas generator can be arbitrarily adjusted. As a result, in various situations such as the speed of the vehicle and the environmental temperature at the time of the collision, it is possible to optimize the deployment of the airbag when the airbag device described later is used.
[0040]
In connection with the embodiment shown in FIG. 2, the two combustion chambers provided in the housing can be further provided adjacent to each other in the axial direction and the radial direction of the housing, as shown in FIG. . Specifically, in the gas generator shown in FIG. 3, a partition wall 107 ′ defining the first combustion chamber 105a ′ and the ignition means and the second combustion chamber 105b ′ is bent in the axial direction. Thereafter, the second combustion chamber 105b ′ is expanded in the axial direction of the housing by abutting the front end thereof with a flange shape on the inner periphery of the housing. As a result, in the gas generator shown in FIG. 3, the second combustion chamber expands in the axial direction, that is, protrudes toward the first combustion chamber, whereby the first combustion chamber and the second combustion chamber. Are adjacent in the axial and radial directions of the housing. Furthermore, in this embodiment, as shown in FIG. 4, when the partition wall 107 "is provided with a peripheral wall that projects the flanged portion at the tip thereof until it abuts against the defining member 160, the first combustion The chamber 105a "and the second combustion chamber 105" are provided adjacent to each other in the radial direction of the housing and coaxially. As a result, the second combustion chamber more than the gas generator shown in FIG. The gas generator shown in FIGS. 3 and 4 can increase the volume of the second combustion chamber, and therefore uses a large amount of the second gas generating agent. 3 and 4, it should be understood that the gas generator shown in FIGS. 3 and 4 has a simple structure and is more compact than the gas generator shown in FIG. Although there is an air bar that can arbitrarily adjust the output form (operating performance) of the gas generator 3 and 4, the same members as those in Fig. 2 are denoted by the same reference numerals, and the description thereof is omitted.
“Embodiment 3”
FIG. 5 is a longitudinal sectional view showing still another embodiment of the gas generator for an air bag of the present invention. The gas generator shown in this figure has a structure particularly suitable for being arranged on the driver's seat side.
[0041]
This gas generator has two combustion chambers and an ignition means accommodation chamber in a housing 3 formed by joining a diffuser shell 1 having a gas discharge port and a closure shell 2 that forms an internal accommodation space together with the diffuser shell. Has been placed.
[0042]
The first combustion chamber 305a is formed of the housing 3 and a substantially cylindrical inner cylinder member 304 disposed therein. In addition, a substantially flat circular partition 307 is disposed in a stepped portion 306 provided on the inner side of the inner cylindrical member 304, and the inner cylindrical member 304 is further divided into two chambers so that the second combustion is performed on the diffuser shell 1 side. An ignition means accommodating chamber 370 is formed on the chamber 305b and the closure shell 2 side. Therefore, in this gas generator, the first combustion chamber 305 a and the second combustion chamber 305 b are provided concentrically in the housing 3 and are adjacent to each other in the radial direction of the housing 3.
[0043]
In the first and second combustion chambers 305a and 305b, gas generating agents (309a and 309b) that burn by an ignition means that operates by impact and generate combustion gas are stored. An ignition means that is activated by an impact is accommodated therein.
[0044]
A through hole 310 is provided in the inner cylinder member 304 that defines the first combustion chamber 305 a and the second combustion chamber 305 b, and the through hole is closed by a seal tape 311. However, since the seal tape 311 bursts when the gas generating agent 309b burns, both the combustion chambers are communicated with each other through the through hole 310. The material and thickness of the seal tape 311 are adjusted so that the seal tape 311 is torn only when the gas generating agent 309b in the second combustion chamber 305b burns. In this embodiment, the tensile strength is 54 kg / mm. ² Thus, a stainless steel seal tape having a thickness of 40 μm is used. The through-hole 310 has an opening area larger than that of the gas discharge port 26, and does not have a function of controlling the internal pressure in the combustion chamber 305b.
[0045]
The igniting means is configured such that an igniter and a charge transfer material are accommodated in an ignition means accommodating chamber. The ignition means accommodating chamber 370 is formed by arranging the first igniter 312a and the second igniter 312b so as to be surrounded by the initiator collar 313, the inner cylinder member 304, and the substantially flat circular partition 307. As shown in the exploded perspective view of FIG. 6, the substantially flat circular partition 307 includes a partition circular member 350 that engages with the stepped portion 306 of the inner cylinder member 304, and a seal that engages with the partition circular member 350. And a cup member 360.
[0046]
Two electric ignition type igniters 312a and 312b are provided in parallel with one initiator collar 313 with their heads protruding. By providing the igniters 312a and 312b in one initiator collar 313 in this way, the two igniters are fixed to the initiator collar 313 to become a single member, and can be easily assembled to the gas generator. In particular, in the gas generator shown in FIG. 5, the initiator collar 313 provided with two igniters 312a and 312b is inserted into the inner cylinder 304 by making the initiator collar 313 large enough to be inserted into the inner cylinder member 304. Thereafter, the initiator collar 313 is fixed by caulking the lower end of the inner cylinder member 304, so that the two igniters can be fixed easily and reliably. Further, when two igniters are arranged on the initiator collar 313, the direction of each igniter can be easily regulated.
[0047]
The partition circular member 350 constituting the partition wall 307 has a substantially flat circular shape, and the opening 351 into which the transfer charge storage chamber 361 of the seal cup member 360 is fitted, and the bottom surface is cut into a circular shape, and the igniter 312b It has a circular hole 352 that accommodates the upper part, and a second heat transfer hole 319 that is formed through the substantial center of the circular hole 352.
[0048]
The seal cup member 360 is inserted into the opening 351 of the compartment circular member 350 and protrudes into the second combustion chamber 305b, and the cylindrical transfer charge storage chamber 361 and the circular hole 352 of the compartment circular member 350. And a cylindrical igniter accommodating port 362 extending to the opposite side to the transfer charge accommodating chamber 361.
[0049]
A charge transfer agent 316a is stored inside the transfer charge storage chamber 361, and a second igniter 312b is fitted in the igniter storage port 362. The compartment circular member 350 and the seal cup member 360 are engaged with and engaged with the transfer charge storage chamber 361 of the seal cup member 360 in the opening 351 of the compartment circular member 350. The upper part of the fitted second igniter 312 b protrudes into the circular hole 352 of the partition circular member 350.
[0050]
As shown in FIG. 5, the partition wall 307 including the partition circular portion 350 and the seal cup member 360 is locked to a stepped portion 306 formed on the inner peripheral surface of the inner cylinder member 304. That is, the peripheral edge of the section circular member 350 is supported by the stepped portion 306, and the seal cup member 360 is supported in contact with the section circular member 350.
[0051]
Further, the peripheral edge of the seal cup member 360 is bent in the same direction as the igniter housing port 362, and the bent portion 363 is fitted in a groove 364 provided on the inner peripheral surface of the inner cylinder member 304. is doing. Accordingly, the circular section 350 is supported by the seal cup member 360 and the movement of the housing 3 in the axial direction is prevented. Further, by inserting the bent portion 363 on the peripheral edge of the seal cup member 360 into the groove 364 on the inner peripheral surface of the inner cylinder member 304, the partition wall 307 (that is, the seal cup member 360) and the inner cylinder member 304 are connected with no gap. Match.
[0052]
Therefore, in the inner cylinder member 304, the ignition means accommodation chamber 308 provided on the closure shell 2 side and the second combustion chamber 305b provided on the diffuser shell 1 side are the seal cup member 360 and the groove 364. It is reliably divided by the ignition means seal structure which consists of these combinations.
[0053]
The igniter accommodating port 362 formed in the seal cup member 360 has a skirt opened in a bowl shape, and between the inside, that is, the second igniter 312b accommodated in the accommodating port 362. The O-ring 381 is disposed, and a seal is provided between the accommodation port 362 and the second igniter 312b.
[0054]
The O-ring 381 is also in pressure contact with an igniter fixing member 382 that fixes the two igniters 312a and 312b to a single initiator collar 313. Therefore, the second igniter 312b is a section circular member. Are arranged in a space defined by a circular hole 352, an igniter receiving port 362 of the seal cup member, an O-ring 381, and an igniter fixing member 382.
[0055]
Therefore, the two igniters 312 a and 312 b arranged on the initiator collar 313 are fixed to an igniter fixing member 382 that is fitted on the initiator collar 313. By using such an igniter fixing member 382, the two igniters 312a and 312b can be easily combined with the initiator collar 313. In the gas generator shown in this embodiment, the first igniter 312a and the second igniter 312b are formed in different sizes and have different operation outputs. An igniter with the same operating output can also be used.
[0056]
In the space partitioned in this manner, the seal tape 320 for closing the second heat transfer hole 319 formed in the circular hole 352 of the partition circular member 350 is ruptured by the operation of the second igniter 312b. Then, it communicates with the second combustion chamber 305b. The first igniter 312a and the second igniter 312b have a seal structure (hereinafter referred to as an “igniter seal structure”) including a skirt portion of the igniter housing port 362, an O-ring 381, and an igniter fixing member 382. ) To ensure separation. Thereby, the flame generated by the operation of one of the igniters does not directly flow into the space in which the other igniters are accommodated.
[0057]
A coolant filter 22 for purifying and cooling the combustion gas generated by the combustion of the gas generating agent (309a, 309b) is disposed in the housing 3, and the inner peripheral surface on the diffuser shell 1 side is a coolant. It is covered with a short path prevention member 23 so that the combustion gas does not pass between the end face of the filter 22 and the inner surface of the diffuser shell 1 ceiling. Outside the coolant filter 22, an outer layer 24 for preventing the filter 22 from expanding due to passage of combustion gas or the like is disposed. The outer layer 24 is formed, for example, using a laminated wire mesh body, or a porous cylindrical member having a plurality of through holes on the peripheral wall surface, or a belt-like restraining layer in which a belt-like member having a predetermined width is formed in an annular shape. You can also. Further, a gap 25 is formed outside the outer layer 24 so that the combustion gas can pass through the entire surface of the filter 22.
[0058]
In the operation of the gas generator shown in the present embodiment, the flame generated by the operation of the first igniter 312a ignites and burns the first transfer charge 316a disposed above the flame. The flame generated by the combustion of the first transfer charge 316a does not flow into the space in which the second igniter 312b is accommodated by the igniter seal structure, and the bent portion of the seal cup member 360 Due to the ignition means seal structure comprising 363 and the groove 364 of the inner cylinder member 304, it does not flow into the second combustion chamber 305b. Therefore, the flame generated by the combustion of the first transfer agent 316a flows into the first combustion chamber 305a exclusively through the first transfer hole 317 formed in the peripheral wall of the inner cylindrical member 304, The first gas generating agent 309a is ignited and burned to generate combustion gas.
[0059]
In addition, the flame generated by the operation of the second igniter 312b flows exclusively into the second combustion chamber 305b through the second heat transfer hole 319 formed in the circular hole 352 of the partition circular member 350. Then, the second gas generating agent 309b is ignited and burned to generate combustion gas. In particular, in the gas generator in this embodiment, the second explosive charge is not arranged, and the second gas generating agent 309a is directly generated by the flame generated by the operation of the second igniter 312b. It is supposed to be ignited and burned.
[0060]
The combustion gas generated by the combustion of the first gas generating agent 309a and the second gas generating agent 309b is then purified and cooled while passing through the common coolant filter 22, passing through the gap 25, It is discharged from the gas outlet 26. The seal tapes 318 and 320 for closing the first and second transfer holes are ruptured when the flame of the igniter and the combustion gas of the charge transfer agent pass, and the seal tape 27 for closing the gas discharge port 26 is free of the combustion gas. Bursts when passing.
“Embodiment 4”
FIG. 7 shows an embodiment of the airbag apparatus of the present invention in a case where the apparatus includes a gas generator using an electric ignition type ignition means.
[0061]
The airbag device includes a gas generator 200, an impact sensor 201, a control unit 202, a module case 203, and an airbag 204. As the gas generator 200, the gas generator described with reference to FIG. 1 is used, and its operation performance is adjusted so as not to give a shock to the occupant as much as possible in the initial stage of the gas generator operation. ing.
[0062]
The impact sensor 201 can be composed of, for example, a semiconductor acceleration sensor. In this semiconductor type acceleration sensor, four semiconductor strain gauges are formed on a beam of a silicon substrate which is bent when acceleration is applied, and these semiconductor strain gauges are bridge-connected. When acceleration is applied, the beam bends and the surface is distorted. Due to this strain, the resistance of the semiconductor strain gauge changes, and the change in resistance is detected as a voltage signal proportional to the acceleration.
[0063]
The control unit 202 includes an ignition determination circuit, and a signal from the semiconductor acceleration sensor is input to the ignition determination circuit. When the impact signal from the sensor 201 exceeds a certain value, the control unit 202 starts computation, and when the computed result exceeds a certain value, outputs an operation signal to the igniters 312a and 312b of the gas generator 200. .
[0064]
The module case 203 is made of polyurethane, for example, and includes a module cover 205. The airbag 204 and the gas generator 200 are accommodated in the module case 203 and configured as a pad module. This pad module is usually attached to the steering wheel 207 when attached to the driver's seat side of the automobile.
[0065]
The airbag 204 is made of nylon (for example, nylon 66) or polyester, and the bag mouth 206 surrounds the gas outlet of the gas generator and is fixed to the flange portion of the gas generator in a folded state. .
[0066]
When the semiconductor acceleration sensor 201 detects an impact at the time of a car collision, the signal is sent to the control unit 202, and when the impact signal from the sensor exceeds a certain value, the control unit 202 starts calculation. When the calculated result exceeds a certain value, an operation signal is output to the igniters 312a and 312b of the gas generator 200. As a result, the igniter 12 operates to ignite the gas generating agent, and the gas generating agent burns to generate gas. This gas is ejected into the air bag 204, whereby the air bag breaks the module cover 205 and inflates to form a cushion that absorbs impact between the steering wheel 207 and the occupant.
[0067]
【Effect of the invention】
According to the present invention, the ignition combustion of the gas generating means in one combustion chamber prevents the gas generating means in the other combustion chamber from being ignited and burned, so that malfunction is prevented and the safety of the gas generator is prevented. And can improve the reliability.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view showing one embodiment of a gas generator of the present invention.
FIG. 2 is a longitudinal sectional view showing another embodiment of the gas generator of the present invention.
FIG. 3 is a longitudinal sectional view showing another embodiment of the gas generator of the present invention.
FIG. 4 is a longitudinal sectional view showing another embodiment of the gas generator of the present invention.
FIG. 5 is a longitudinal sectional view showing another embodiment of the gas generator of the present invention.
6 is an exploded perspective view showing the partition wall of FIG. 5. FIG.
FIG. 7 is a configuration diagram of the airbag device of the present invention.
[Explanation of symbols]
3 Housing
5a First combustion chamber
5b Second combustion chamber
7 Bulkhead
9a First gas generating agent
9b Second gas generant
12a First igniter
12b Second igniter
13 Initiator color
22 Coolant filter
305a First combustion chamber
305b Second combustion chamber
307 Bulkhead
309a First gas generating agent
309b Second gas generating agent
312a first igniter
312b Second igniter
313 Initiator color
350 compartment circular member
360 Seal cup member
370 Ignition means accommodation chamber
382 igniter fixing member

Claims (6)

The housing (3) having the gas discharge port (26) includes an igniter that is activated by impact, and a gas generating agent that generates a combustion gas that is ignited and burned by the igniter to inflate the airbag. A gas generator for an air bag,
In the housing (3), a first combustion chamber (5a) and a second combustion chamber (5b) for accommodating the gas generating agents (9a, 9b) are provided concentrically adjacent to each other in the radial direction of the housing. Furthermore, a communication hole (10) that allows the first combustion chamber (5a) and the second combustion chamber (5b) to communicate with each other is provided,
A first igniter (12a) for igniting the gas generating agent (9a) stored in the first combustion chamber (5a); and a gas generating agent stored in the second combustion chamber (5b) ( A second igniter (12b) is provided for igniting 9b),
Metal having a tensile strength of 15 kg / mm ² or more and a thickness of 10 to 200 μm, the communication hole (10) being broken only by the combustion of the gas generating agent (9b) accommodated in the second combustion chamber (5b) Blocked by a thin plate (11),
During operation, the combustion gas generated in the second combustion chamber (5b) breaks the thin metal plate (11), passes through the communication hole (10), and flows into the first combustion chamber (5a). Yes,
When the first igniter (12a) is activated first and the second igniter (12b) is activated later, the first igniter (12a) and the second igniter (12b) are activated simultaneously. And an air bag gas generator characterized by being able to carry out the operation of only the first igniter (12a). In a housing (103) having a cylindrical shape whose axial length is longer than the outermost diameter and having a plurality of gas discharge ports (126) on its peripheral wall, an igniter that operates by impact, and the igniter A gas generator for an air bag containing and containing a gas generating agent that generates a combustion gas for ignition and combustion to inflate an air bag;
In the housing (103), a first combustion chamber (105a ′) and a second combustion chamber for accommodating a gas generating agent are coaxially adjacent to each other in the axial direction and the radial direction of the housing (103). Provided with a communication hole (110) that allows the first combustion chamber (105a ′) and the second combustion chamber (105b ′) to communicate with each other,
The first igniter (12a) for igniting the gas generating agent (9a) stored in the first combustion chamber (105a '), and the gas generation stored in the second combustion chamber (105b') A second igniter (12b) for igniting the agent (9b) is provided,
The communication hole (110) is broken only by the combustion of the gas generating agent (9b) accommodated in the second combustion chamber (5b), and has a tensile strength of 15 kg / mm ² or more and a thickness of 10 to 200 μm. Blocked by a thin plate (11),
During operation, the combustion gas generated in the second combustion chamber (105b ′) breaks the metal thin plate (11), passes through the communication hole (110), and further passes through the first combustion chamber (105a ′). It is discharged from the gas outlet (126)
When the first igniter (12a) is activated first and the second igniter (12b) is activated later, the first igniter (12a) and the second igniter (12b) are activated simultaneously. And a gas generator for an air bag, wherein only the first igniter (12a) is operated. In a housing (103) having a cylindrical shape whose axial length is longer than the outermost diameter and having a plurality of gas discharge ports (126) on its peripheral wall, an igniter that operates by impact, and the igniter A gas generator for an air bag containing and containing a gas generating agent that generates a combustion gas for ignition and combustion to inflate an air bag;
In the housing (103), a first combustion chamber (105a '') and a second combustion chamber (105b '') each containing a gas generating agent are adjacent to each other in the radial direction of the housing (103). A communication hole (110) that is provided on the same axis and that allows the first combustion chamber (105a '') and the second combustion chamber (105b '') to communicate with each other is provided.
The first igniter (12a) for igniting the gas generant (9a) accommodated in the first combustion chamber (105a '') and the second combustion chamber (105b ''). A second igniter (12b) for igniting the gas generating agent (9b) is provided;
The communication hole (110) is broken only by the combustion of the gas generating agent (9b) accommodated in the second combustion chamber (5b), and has a tensile strength of 15 kg / mm ² or more and a thickness of 10 to 200 μm. Blocked by a thin plate (11),
During operation, the combustion gas generated in the second combustion chamber (105b '') breaks the metal thin plate (11), passes through the communication hole (110), and further passes through the first combustion chamber (105a ''). Through the gas outlet (126),
When the first igniter (12a) is activated first and the second igniter (12b) is activated later, the first igniter (12a) and the second igniter (12b) are activated simultaneously. And a gas generator for an air bag, wherein only the first igniter (12a) is operated.   Combustion gas generated by the combustion of the gas generating means accommodated in the two combustion chambers reaches the gas outlet through a different flow path for each combustion chamber, and the gas generating means accommodated in one combustion chamber The gas generator for an air bag according to any one of claims 1 to 3, wherein the gas generator is not directly ignited by a combustion gas generated in another combustion chamber.   5. The gas generator for an air bag according to claim 4, wherein a flow path forming member is disposed in the housing to form a flow path, and the combustion gas generated in one combustion chamber is directly guided to the coolant means.   A gas generator for an air bag, an impact sensor that senses an impact and activates the gas generator, an air bag that expands by introducing gas generated by the gas generator, and a module case that houses the air bag The airbag gas generator according to claim 1, wherein the airbag gas generator is the airbag gas generator according to claim 1.

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