JP2001171474A - Gas generator and airbag device for airbag - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To provide a gas generator for an air bag with improved safety and reliability. SOLUTION: Even when a gas generating agent 9a in a first combustion chamber 5a burns, the gas generating agent 9b is burned by the action of a thin metal plate 11 that closes a communication hole 10 with a second combustion chamber 5b. Is prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a gas generator for an air bag and an air bag device using the same.

[0002]

2. Description of the Related Art An airbag system mounted on an automobile and various other vehicles is an airbag (bag body) which is rapidly inflated by gas when the vehicle collides at a high speed. ) To support the occupant and prevent the occupant from being injured by crushing a hard part inside the vehicle such as a steering wheel or a front glass due to inertia. Such an airbag system generally includes a gas generator that is activated by a collision of a vehicle to release gas, and an airbag that expands by introducing the gas.

[0003] Such an airbag system can be used even if the occupant's physique (for example, a person with a high or low sitting height, an adult or a child, etc.), or his / her riding posture (for example, a posture holding on to a steering wheel) is different. It is desirable that the occupant can be restrained safely. Therefore, conventionally, an airbag system has been proposed which operates in the early stage of operation with as little impact as possible on the occupant. Such gas generators are disclosed in JP-A-8-207696, U.S. Pat.No. 4,998,751 and U.S. Pat.
And in Japanese Patent Application Laid-Open No. 8-207696,
Ignite two types of gas generating agent capsules with one igniter,
A gas generator that generates gas in two stages is disclosed in U.S. Pat.
No. 998,751 and U.S. Pat.No. 4,950,458 each propose a gas generator that provides two combustion chambers for regulating the operation function of the gas generator and generates gas in two stages by the spread of the gas generating agent. .

A gas generator provided with two combustion chambers as described above is excellent in that gas can be generated in two stages, but in that case, malfunction is prevented and product safety is reduced. In order to enhance the reliability, it is important that the ignition of the gas generating agent in one combustion chamber does not cause the ignition of the gas generating agent in the other combustion chamber.

Accordingly, the present invention ensures safety and reliability in a gas generator provided with two combustion chambers,
An object of the present invention is to provide a gas generator for an air bag, which can stably and effectively exhibit the characteristic that gas can be generated in two stages, and an air bag device using the same.

[0006]

According to one aspect of the present invention, there is provided, in a housing having a gas discharge port, an igniting means which is operated by an impact, and an igniter and an igniter which are ignited by the igniting means.
A gas generator for an airbag containing gas generating means for generating a combustion gas for inflating an airbag when inflated, wherein two housings each containing the gas generating means are provided in the housing. A chamber is provided, and further, a communication hole is provided to enable the respective combustion chambers to communicate with each other. The communication hole has a tensile strength of 15 kg / mm ² or more and a thickness of 1 kg.
Provided is a gas generator for an air bag, wherein the gas generator is closed with a metal sheet of 0 to 200 μm.

Further, according to the present invention, in the gas generator for an air bag described above, two combustion chambers for accommodating the gas generating means are provided concentrically adjacent to each other in a radial direction of the housing. An airbag gas generator provided with a communication hole capable of communicating with each other can be provided.

Further, according to the present invention, in the gas generator for an air bag described above, two combustion chambers accommodating the gas generating means are provided concentrically adjacent to each other in a radial direction of the housing, and the combustion chambers are mutually connected. The inner combustion chamber of the two combustion chambers is provided in an upper space side of an inner cylinder member disposed in the housing, and the ignition means is provided in the inner cylinder member. , And the upper space and the lower space are defined by a partition wall.

According to another aspect of the present invention, there is provided a housing having a cylindrical shape having an axial center longer than an outermost diameter and having a plurality of gas outlets on a peripheral wall thereof, which is operated by impact. An airbag gas generator containing an ignition means and gas generation means for generating combustion gas for igniting and burning by the ignition means to inflate the airbag, wherein the gas generator for an airbag is housed in the housing. Two combustion chambers accommodating the gas generating means are provided coaxially adjacent to each other in the axial direction and / or the radial direction of the housing, and further provided with a communication hole which allows the respective combustion chambers to communicate with each other. And the communication hole has a tensile strength of 15 kg / mm ² or more,
Provided is a gas generator for an airbag, wherein the gas generator is closed with a thin metal plate having a thickness of 10 to 200 μm.

[0010] As described above, the communicating hole to each other can communicate with the combustion chambers with each other, a tensile strength of 15 kg / mm ² or more, preferably at 25 to 60 kg / mm ² or more, thickness of 10~200μm Metal sheet, preferably 20-100
The gas generating means (the gas generating means that ignites and burns first) contained in one combustion chamber is burned by the ignition of one igniter by being closed with a thin metal plate (for example, a seal tape) of μm. The pressure generated thereby ruptures the metal sheet and prevents the gas generating means (the second gas generating means that ignites and burns) housed in another combustion chamber from burning. By setting the thickness of the metal sheet to 10 μm or more, the above-described prevention effect can be obtained. By setting the thickness of the metal sheet to 200 μm or less, the force of the pressure-sensitive adhesive layer when the metal sheet adhered in a curved shape to return to a flat shape according to the shape of the portion where the communication hole is formed is increased. It can be prevented from becoming larger and easily peeling. As the metal sheet, for example, a sheet made of aluminum, stainless steel, or copper can be used.

The gas generating means is for inflating an airbag for restraining an occupant with the combustion gas generated by the combustion. Therefore, even if the ignition means includes a transfer charge for igniting and burning by the igniter and burning the gas generation means, the combustion gas generated by the combustion of the transfer charge burns the gas generation means. In that it is not intended to directly inflate the airbag. Also,
In the point that the two combustion chambers provided in the housing are chambers exclusively for accommodating gas generating means, the ignition means is configured to include a transfer charge, and a space in which the transfer charge is defined. (Hereinafter referred to as a "storage chamber.") Even if the transfer chamber is housed in the transfer charge, the combustion chamber that houses the gas generating means can be clearly distinguished.

When the igniting means for igniting and burning the gas generating means includes two or more igniters operated by an impact, the igniters are connected to each other in the axial direction in order to facilitate the mounting. Are desirably provided for one initiator color. Further, when the ignition means further includes a transfer charge that is ignited and burned by the operation of the igniter, the transfer charge is divided for each of the igniters and ignited independently for each of the igniters. -It is desirable to form so that the flame which burns and burns the transfer agent corresponding to any one of the igniters does not directly ignite the transfer agent corresponding to the other igniter. As such a structure, for example, each igniter is arranged in an independent igniter accommodating chamber, and a transfer charge is arranged in the igniter accommodating chamber, or in each of the separately independent combustion chambers, Ignition by the operation of the vessel
It can be located where it can be burned.

As described above, when the transfer charge is divided for each igniter, the gas generating means accommodated in the two combustion chambers is ignited and burned by the flames in which the transfer charge of the different division is burned. . In other words, according to the operation timing of the igniter, the transfer charge of each section burns, and the gas generating means in each combustion chamber can burn separately, so that the operation performance of the gas generator can be adjusted arbitrarily. it can.

Therefore, by changing the ignition timing for each igniter, the transfer charge classified for each igniter can be separately burned, and accordingly, the ignition and combustion timing of the gas generating means in each combustion chamber can be changed. Since it can be shifted, the operation output of the gas generator can be arbitrarily adjusted.

[0015] The two combustion chambers provided in the housing, one of the combustion chambers is provided in the axial direction of the igniter,
Other combustion chambers can be provided radially of the ignition means. Further, when the operating performance of the gas generator, particularly the change over time of the gas emission amount is more characteristically adjusted, the combustion speed, the composition, the composition ratio, or the amount of each combustion chamber is provided in each of the two combustion chambers. At least one or more different gas generating means can be accommodated, and they can be independently ignited and burned at an arbitrary timing. Further, each combustion chamber may be filled with gas generating means having a different amount of gas generated per unit time.

As the gas generating means, in addition to an azide-based gas generating agent based on an inorganic azide, for example, sodium azide (sodium azide), which has been widely used, a non-azide-based gas generating agent not based on inorganic azide is used. can do. However, in consideration of safety, a non-azide-based gas generating agent is desirable. As such a non-azide-based gas generating composition, for example, a nitrogen-containing organic compound such as tetrazole, triazole, or a metal salt thereof and an alkali metal Those containing an oxygen-containing oxidizing agent such as nitrate as a main component, triaminoguanidine nitrate, carbohydrazide, nitroguanidine, etc. as a fuel and a nitrogen source, and an alkali metal or alkaline earth metal nitrate, chlorate as an oxidizing agent, Various compositions such as a composition using perchlorate can be used. In addition, the gas generating means is appropriately selected according to requirements such as a burning rate, non-toxicity, a burning temperature, and a decomposition starting temperature. When using gas generating means having different combustion rates for each combustion chamber, for example, the composition and composition ratio itself, such as using an inorganic azide such as sodium azide or a non-azide such as nitroguanidine as a fuel and a nitrogen source, etc. In addition to using different gas generating means, changing the shape of the composition such as a pellet, a wafer, a hollow column, a disk, a single-hole or a porous body, or depending on the size of the molded body, etc. Gas generating means having a different 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. 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 are substantially equal is desirable. Specifically, for example, in the case of a cylindrical molded body having a circular cross-section, one having a center at the center and six having a hole center at the apex of an equilateral triangle equidistant from each other. Is preferred. One more in the center and 18 around
An arrangement with individual holes is also conceivable. The number and arrangement of these holes are determined by the ease of manufacturing the gas generating agent and the balance between manufacturing cost and performance, and are not particularly limited.

Of the two combustion chambers, the combustion chamber provided on the radially outer side of the two combustion chambers contains, on the peripheral wall side of the housing, a coolant means for cooling the combustion gas generated by the combustion of the gas generation means. You can also. This coolant means is provided 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 filter for purifying a conventionally used combustion gas is used. In addition to using a coolant for cooling the generated combustion gas, a laminated wire mesh filter formed by compressing and forming a wire mesh made of an appropriate material into an annular laminate can also be used. This laminated wire mesh coolant is desirably formed by forming a flat knitted stainless steel wire mesh into a cylindrical body, and repeatedly bending one end of the cylindrical body outward to form an annular laminated body. A compression-molded or flat-knit stainless steel wire mesh is formed in a cylindrical body, and this cylindrical body is pressed in the radial direction to form a plate body, and the plate body is wound into a cylindrical shape in multiple layers to form a laminate. And compression molding in a mold or the like.
Further, the inside and the outside may have a double-layered structure with different laminated metal nets, and may have a function of protecting the coolant means on the inside and a function of suppressing the expansion of the coolant means on the outside. By supporting the outer periphery of the coolant means with an outer layer made of a laminated metal mesh, a porous cylinder, an annular belt, or the like, the swelling can be suppressed.

Further, the combustion gas generated by the combustion of the gas generating means housed in the two combustion chambers reaches the gas outlet through different flow paths for each of the combustion chambers, and the gas housed in one combustion chamber. When the generating means is a gas generator which is not directly ignited by the combustion gas generated in another combustion chamber, the gas generating means in each combustion chamber is completely independent for each combustion chamber. From burning,
The ignition and combustion of the gas generating means accommodated in each combustion chamber can be performed 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 first igniter operates, Does not burn, 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.

The housing may be formed by casting, forging or pressing a diffuser shell having a gas discharge port and a closure shell forming an accommodation space together with the diffuser shell, and joining the two shells. it can. The two shells can be joined by various welding methods, for example, electron beam welding, laser welding, TIG welding, prosection welding and the like. When the diffuser shell and the closure shell are formed by pressing various steel plates such as a stainless steel copper plate, both shells can be easily manufactured and the manufacturing cost can be reduced. Further, by forming both shells into 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 preferable, but a nickel-plated steel plate may be used.

The housing further houses ignition means which operates upon sensing an impact to ignite and burn the gas generating means. As the ignition means, the gas generator of the present invention uses an electric ignition type ignition means which is operated by an electric signal (or an operation signal) transmitted from an impact sensor or the like which senses an impact. The electric ignition type 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 configured to include a transfer charge.

The above-described gas generator for an air bag is housed in a module case together with an air bag (bag body) that introduces and inflates the gas generated by the gas generator to form an air bag device. In this airbag device, the gas generator operates in conjunction with the detection of the impact by the impact sensor, and discharges the combustion gas from the gas outlet of the housing. This combustion gas flows into the airbag, which breaks the module cover and bulges, forming a shock absorbing cushion between the rigid structure in the vehicle and the occupant.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a gas generator for an air bag according to the present invention will be described based on an embodiment shown in the drawings. Embodiment 1 FIG. 1 is a longitudinal sectional view of a gas generator for an air bag according to a first embodiment of the present invention, and has a structure particularly suitable for being arranged on a driver's seat side.

This gas generator is provided with a substantially cylindrical inner cylinder member in a housing 3 in which a diffuser shell 1 having a gas discharge port and a closure shell 2 forming an internal accommodating space together with the diffuser shell. 4 is disposed, and the outside thereof is used as a first combustion chamber. In addition, a stepped portion 6 is provided inside the inner cylinder member, and a substantially plate-shaped partition 7 is disposed in the stepped portion, and the inside of the inner cylinder is further defined by the partition into two chambers. The second combustion chamber 5b is formed on the diffuser shell side (upper space side), and the ignition means housing 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 within the housing 3 and are adjacent to the housing in the radial direction. In the first and second combustion chambers, gas generating agents (9a, 9b) that are burned by the igniting means operated upon receiving an impact and generate combustion gas are accommodated. An ignition means operated by an impact is accommodated. The inner cylinder member 4 that defines the first combustion chamber 5a and the second combustion chamber 5b is provided with a through-hole 10, which is closed by a seal tape 11. However, since the seal tape 11 bursts when the gas generating agent burns, the two combustion chambers can communicate with each other through the through holes 10.

The seal tape 11 is not broken by the combustion of the gas generating agent 9a in the first combustion chamber 5a, and is not broken by the second combustion chamber 5b.
It is necessary to adjust the material and thickness of the gas generating agent 9b so that the gas generating agent 9b is broken when burned. In the present embodiment, a stainless seal tape having a tensile strength of 54 kg / mm ² and a thickness of 40 μm is used. Also, the through hole 10 is a gas outlet.
The opening area is wider than that of 26b, and it has no function of controlling the internal pressure in the combustion chamber 5b.

The ignition means includes two electric ignition type igniters (12a, 12b) which are activated by an activation signal outputted based on the fact that the sensor detects an impact,
The igniters are provided on one initiator collar 13 in parallel with each other with their heads protruding. In this manner, two igniters (12a, 12a
By providing b), the two igniters are fixed to the initiator collar 13 to be a single member, and can be easily assembled to the gas generator. In particular, in the gas generator shown in this figure, the initiator collar 13 having two igniters (12a, 12b) is formed by making the initiator collar 13 large enough to be inserted into the inner cylinder member 4. After being inserted into the inner cylinder 4, the lower end of the inner cylinder member 4 is swaged to fix the initiator collar, so that the igniter can be easily and surely fixed. Further, when the two igniters (12a, 12b) are arranged on the initiator collar 13, the directions of the respective igniters can be easily regulated. This 2 on 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 orientation, 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 (FIG. (Not shown) can be pulled out in the same direction on the same plane. In FIG.
The lead wires 50 are respectively connected to the igniters (12a, 12b) via connectors 50a, and the connectors are provided in parallel on the same plane. By making this connector L-shaped, a lead wire for transmitting an electric signal (operation signal) to the igniter can be pulled out in a direction orthogonal to the axial direction of the housing (that is, in the radial direction of the housing). At this time, the lead wires connected to each igniter can be pulled out in the same direction.

In this embodiment, the initiator color
One of the igniters 12b is provided in the space between the
(Hereinafter, referred to as a “second igniter”), a substantially cylindrical separation tube 14 is disposed, and a first transfer agent storage chamber 15a is provided outside the separation tube 14 and a second transfer agent storage room is provided inside. Room 15b is defined,
In each of the accommodation chambers, an igniter and a transfer charge that constitutes ignition means together with the igniter are accommodated. As a result, the transfer charge (16a, 16b) constituting the ignition means together with the igniter is surely divided for each igniter (12a, 12b). This first explosive charge storage chamber 15a holds the explosive charge 1 contained therein.
When 6a burns, the seal tape 18 that closes the heat transfer hole 17 formed in the inner cylinder member 4 bursts and communicates with the first combustion chamber 5a. In addition, the second charge storage chamber 15b also has the charge 1 therein.
When 6b burns, the seal tape 20 that closes the heat transfer hole 19 formed in the partition 7 ruptures and communicates with the second combustion chamber 5b.
Therefore, when the gas generator is activated, the flame when the first igniter 12a is ignited (activated) is supplied to the storage chamber 15a.
Ignites and burns the explosive charge 16a therein, and the flame passes through the heat transfer hole 17 formed in the inner cylinder member 4 and is accommodated in the first combustion chamber 5a located in the radial direction of the accommodation chamber 15a. The gas generating agent 9a having seven holes is ignited and burned. Also 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 the second combustion on the extension thereof The single-hole gas generating agent 9b housed in the chamber 5b is ignited and burned. The combustion gas generated in the second combustion chamber 9b flows into the first combustion chamber 5a through the through hole 10 provided on the diffuser shell 1 side of the inner cylinder member 4.

In particular, in the gas generator shown in FIG. 1, in order to stabilize the operation performance, the second igniter 12b and the first igniter 12a
May ignite at the same time, but the former 12b does not operate before the latter 12a. That is, the gas generating agent 9b accommodated in the second combustion chamber 5b burns simultaneously with or after 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. A gas generating agent
It is not broken by the combustion of 9a, but is broken only by the combustion of the second gas generating agent 9b.

Further, in the gas generator shown in this figure, the separation cylinder 14 disposed between the initiator collar and the partition is provided with the lower surface of the partition 7 and the initiator collar 13 as shown in an enlarged view of the main part of FIG. A hole corresponding to the outer shape of the separation tube 14 on the upper surface
21 are provided, and the upper end or the lower end of the separation tube 14 is fitted into each of the hole portions. By arranging the separation tube 14 in this manner, the flame of the transfer charge generated in any one transfer charge combustion chamber does not directly burn the transfer charge in the other transfer charge accommodating chamber. The gas generating agents accommodated in the combustion chamber are ignited and burned by the flames in which the different types of transfer charges burn. That is, when the transfer charge is burned in the separation tube 14 (that is, the second transfer charge storage chamber), the pressure of the gas generated by the combustion usually causes the separation tube to spread in the radial direction. By arranging the separation cylinder as shown in FIG. 3, the upper and lower ends of the separation cylinder are reliably supported by the peripheral walls of the holes into which the separation cylinders are fitted. Leakage of the combustion gas / flame of the transfer charge can be more reliably prevented as compared with the case where the fuel cell is sandwiched between the partition wall and the initiator collar.

In the housing 3, a gas generating agent (9a,
A common coolant / filter 22 for purifying and cooling the combustion gas generated by the combustion of 9b) is provided. It is covered with a short path preventing member 23 so that the combustion gas does not pass between the inner surface 28 of the ceiling and the inside. Outside the coolant / filter 22, an outer layer 24 for suppressing swelling of the filter 22 due to passage of combustion gas or the like is arranged.
The outer layer 24 is formed using, for example, a laminated metal mesh body, a porous cylindrical member having a plurality of through holes in a peripheral wall surface, or a belt-shaped restraining layer formed by annularly forming a band member having a predetermined width. You can also. Further, on the outside of the outer layer 24,
A gap 25 is formed 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 by a seal tape 27 to prevent the outside air from entering. This sealing tape
27 bursts when releasing gas. The purpose of the seal tape 27 is to protect the gas generating agent from external moisture,
It does not affect performance adjustment such as combustion internal pressure at all.

In the gas generator formed as described above, when the first igniter 12a disposed inside the ignition means accommodating chamber 8 and outside the separation tube 14 is operated, the first transfer agent accommodation is performed. Room 15a
The transfer charge 16a housed therein ignites and burns, and the flame passes through the transfer hole 17 of the inner cylinder member 4 and has a porous cylindrical shape having seven holes housed in the first combustion chamber 5a. One gas generating agent 9a
To burn. Further, when the second igniter 12b surrounded by the separation tube 14 operates at the same time or with a delay as the first igniter 12a, the transfer charge 16b stored in the second transfer charge storage chamber 15b
Ignites and burns, 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 operation of the first igniter, or the first igniter and the second igniter are operated. , The output form (operating performance) of the gas generator can be arbitrarily adjusted. The deployment of the airbag in the vehicle can be maximized. In particular, in the gas generator shown in this figure, a gas generating agent (9a, 9b) having a different shape is used for each combustion chamber (5a, 5b), and the first combustion chamber 5a has a perforated cylindrical second gas. One gas generating agent 9a is used for the second combustion chamber 5b.
Each contain a single-hole cylindrical second gas generating agent 9b. Also, the amount of the gas generating agent contained in each combustion chamber (5a, 5b) is different, and 35 g of gas generating agent (9a, 9b) in the first combustion chamber 5a and 6g in the second combustion chamber 5b. ) Are accommodated. As a result, in this gas generator, the output form can be adjusted more accurately. The shape, composition, composition ratio, amount and the like of the gas generating agent can of course 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 side.

The gas generator shown in this figure has a cylindrical shape whose axial center is longer than the outermost diameter, and has an ignition operated by an impact in a housing 103 having a plurality of gas outlets on its peripheral wall. Means, a gas generating agent (9a, 9b) which is ignited and burned by the ignition means and generates combustion gas for inflating the airbag, and cooling and / or purifying the combustion gas generated by combustion of the gas generating agent And a coolant / filter 122. And housing 1
Two combustion chambers (105a, 105b) provided in 03 are formed as a cylindrical combustion chamber 105a and an annular combustion chamber 105b, and are provided coaxially adjacent to the housing 103 in the axial direction. A communication hole 110 is provided to enable the respective combustion chambers (105a, 105b) to communicate with each other.

The gas generator shown in the present embodiment has an axially long shape because the housing has a cylindrical shape that is long in the axial direction. In the gas generator having such a shape, particularly, , Two combustion chambers (105a, 105b) as described above
Is a combination of a cylindrical combustion chamber 105a and an annular combustion chamber 105b. In addition, the gas generator has a simple structure and can be easily manufactured while adjusting the timing of the output rise.

The igniting means includes two or more igniters operated by impact, and each igniter (12a, 1a
2b) is provided in one initiator collar 113 in parallel with each other, so that its assembly is easy. Further, each of the igniters (12a, 12a, 12a, 12a) mounted on the one initiator collar 113 and housed in the housing.
b) is eccentric with respect to the axis of the housing.

In the housing 103, a substantially cylindrical coolant filter 122 is provided so as to face the inner peripheral surface of the housing in which a plurality of gas outlets 126 are formed.
A predetermined gap 1 is provided between the filter 122 and the inner circumference of the housing.
25 are secured. A first combustion chamber 105a is defined adjacent to a space in which the coolant / filter 122 is accommodated, and ignition means including two igniters (12a, 12b) It is arranged coaxially 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. It will be provided as. Each of the first and second combustion chambers has a different gas generating agent (9a, 9b).
In the gas generator shown in this figure, the first combustion chamber 105a has a first cylindrical gas generating agent 9a,
In the second combustion chamber 105b, a single-hole cylindrical second gas generating agent 9b is provided.
Are accommodated respectively.

The ignition means is ignited and burned by the operation of the igniters (12a, 12b), and the flame generates a gas generating agent (105a, 105b).
The ignition charge of b) is included, and this ignition charge is defined for each igniter, and ignites and burns independently for each igniter. The space for accommodating the transfer charge defined for each igniter is defined by a cylindrical member, and the first transfer charge storage chamber for storing the first transfer charge 116a.
115a communicates with the first combustion chamber 105a through a heat transfer hole 119 of a partition wall 107 disposed between the ignition means and the first combustion chamber 105a, and a second transfer charge 116b is accommodated therein. The charge storage chamber 115b
A communication hole 117 formed in the tubular member 104 defining the storage chamber 115b communicates with the second combustion chamber 105b.

The first combustion chamber 105a and the second combustion chamber 10
5b means that the seal tape 11 that closes the through hole 110 formed in the partition 107 ruptures due to the combustion of the second gas generating agent 9b, so that the seal tape 11 communicates with the through hole 110. In the present embodiment, a stainless seal tape having a tensile strength of 54 kg / mm ² and a thickness of 40 μm is used.
Since this 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.

In the gas generator shown in this figure, when the first igniter 12a operates, the charge 1 in the first charge storage chamber 115a is charged.
16a is ignited and burns, and the flame is transferred to the
Through 9, the gas generating agent 9 a arranged in the first combustion chamber 105 a is ignited and burned to generate combustion gas. This combustion gas is purified and cooled while passing through the coolant / filter 122, and is discharged from the gas outlet 126. on the other hand,
When the second igniter 12b operates, the second charge storage chamber 115
The transfer agent 116b in b fires and burns, and the flame ignites and burns the gas generating agent 9b in the second combustion chamber 105b. 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 107, and is purified and cooled while passing through the coolant filter 122,
It is 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 the same coolant and
Purified and cooled while passing through the filter 122. In addition,
Also in the present embodiment, 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 a 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. The heat transfer hole 119 is closed by the seal tape 20, and the heat transfer hole 117 is closed by the seal tape 18.

A defining member 160 which defines the first combustion chamber 105b and a space in which the coolant / filter 122 is accommodated is provided with a communication hole 161 for communicating the two chambers. The combustion gas generated in the second combustion chamber (105a, 105b) passes through the communication hole 161 and the coolant / filter 122
To reach the accommodation space. In this embodiment, a communication hole 161 having a size substantially equal to the inner diameter of the coolant / filter 122 is formed in the defining member 160. And the gas generating agent 9a in the first combustion chamber 105a is
A wire mesh 162 is provided so as not to move toward the space where the coolant / filter 122 is accommodated during the combustion. The wire mesh 162 is a mesh having a size that can prevent the movement of the first gas generating agent 9a during combustion, and may be of any type as long as it does not have ventilation resistance to control combustion performance. Absent.

As described above, also in the gas generator of this embodiment, the gas generating agents (9a, 9b) housed in the respective combustion chambers (105a, 105b) operate the two igniters (12a, 12b). By adjusting the timing, ignition and combustion are performed independently, and the output form (operating performance) of the gas generator can be arbitrarily adjusted. As a result, in various situations such as the speed of the vehicle at the time of the collision and the environmental temperature, the deployment of the airbag in the case of the airbag device described below can be maximized.

In connection with the embodiment shown in FIG. 2, two combustion chambers provided in the housing are provided so as to be adjacent to each other in the axial direction and the radial direction of the housing, as shown in FIG. You can also. Specifically, in the gas generator shown in FIG. 3, the partition 107 ′ that defines the first combustion chamber 105 a ′, the ignition means, and the second combustion chamber 105 b ′
After being bent in the axial direction, the distal end of the second combustion chamber is brought into contact with the inner periphery of the housing as a flange shape.
105b 'extends in the axial direction 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, so that the first combustion chamber and the second combustion chamber Are adjacent in the axial and radial directions of the housing. Further, in this embodiment, as shown in FIG. 4, when a partition wall 107 ″ is provided with a peripheral wall that protrudes a flange-shaped portion at its tip until it comes into contact with the defining member 160, the first combustion The chamber 105a "and the second combustion chamber 105" are provided radially adjacent to and coaxial with the housing. As a result, FIG.
The volume of the second combustion chamber can be made larger than that of the gas generator shown in FIG. In particular, the gas generators shown in FIGS. 3 and 4 can increase the volume of the second combustion chamber, which is advantageous when a large amount of the second gas generating agent is used. Also, needless to say, the gas generator shown in FIGS. 3 and 4 has the same simple structure as the gas generator shown in FIG. It becomes a gas generator for an airbag in which the output form (operating performance) of the device can be adjusted as desired. In the gas generators shown in FIGS. 3 and 4, the same members as those in FIG. 2 are denoted by the same reference numerals, and description thereof will be 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.

This gas generator has two combustion chambers and ignition means in a housing 3 in which a diffuser shell 1 having a gas outlet and a closure shell 2 forming an internal storage space together with the diffuser shell are joined. The accommodation room is arranged.

The first combustion chamber 305a is formed of the housing 3 and a substantially cylindrical inner cylinder member 304 disposed therein. A substantially flat circular partition 307 is arranged in a stepped portion 306 provided inside the inner cylinder member 304, and the interior of the inner cylinder member 304 is further divided into two chambers.
Combustion chamber 305b, the ignition means accommodating chamber on the closure shell 2 side
370 are formed. Therefore, in this gas generator,
The first combustion chamber 305a and the second combustion chamber 305b are
And are concentrically arranged inside the housing 3 and are adjacent to the housing 3 in the radial direction.

In the first and second combustion chambers 305a and 305b, gas generating agents (309a and 309b) which are burned by the ignition means operated upon receiving an impact and generate combustion gas are contained. In the accommodation room 370, an ignition means operated by an impact is accommodated.

The inner cylinder 304 defining the first combustion chamber 305a and the second combustion chamber 305b is provided with a through hole 310, which 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 connected to the through holes 310.
Are communicated by The material and thickness of the sealing tape 311 are adjusted so that the gas generating agent 309b in the second combustion chamber 305b is broken only when burned. In the present embodiment,
A stainless steel sealing tape having a tensile strength of 54 kg / mm ² and a thickness of 40 μm is used. The through-hole 310 has a larger opening area than the gas discharge port 26, and has no function of controlling the internal pressure in the combustion chamber 305b.

The ignition means has an igniter and a transfer charge accommodated in an ignition means accommodation chamber. Ignition chamber 37
0 denotes a case where the first igniter 312a and the second igniter 312b are connected to the initiator collar 313, the inner cylindrical member 304, and the substantially flat circular partition 30.
7 so as to surround it. As shown in an exploded perspective view of FIG. 6, a partition 307 having a substantially flat circular shape is provided with a partition circular member 350 which is engaged with the stepped portion 306 of the inner cylindrical member 304 and a seal which is engaged with the partition circular member 350. And a cup member 360.

The two electric igniters 312a and 312b are:
One initiator collar 313 is provided in parallel with each other with its head protruding. By providing the igniters 312a and 312b on one initiator collar 313 in this way, the two igniters are fixed to the initiator collar 313 to be a single member, and the assembly to the gas generator becomes easy. In particular, in the gas generator shown in FIG. 5, the initiator collar 313 having the 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. Then, by caulking the lower end of the inner cylinder member 304 and fixing the initiator collar 313, the two igniters can be easily and reliably fixed. Further, when the two igniters are arranged on the initiator collar 313, the directions of the respective igniters can be easily regulated.

The partitioning circular member 350 constituting the partition wall 307 has a substantially flat circular shape, and has an opening 351 in which the transfer agent accommodating chamber 361 of the seal cup member 360 is fitted, and a bottom surface is hollowed out in a circular shape, and ignition is performed. Circular hole 352 for accommodating the upper portion of the vessel 312b, and a second fire hole 319 penetrating substantially through the center of the circular hole 352.
And

The seal cup member 360 includes a cylindrical charge storage chamber 361 that fits into the opening 351 of the circular section member 350 and protrudes into the second combustion chamber 305b.
And a cylindrical igniter accommodating port 362 that is formed at a position facing the circular hole 352 and extends on the opposite side to the transfer charge accommodating chamber 361.

Inside the explosive charge accommodating chamber 361, the explosive charge 316a is provided.
The second igniter 312b is fitted in the igniter accommodating port 362. The partitioning circular member 350 and the seal cup member 360 engage with the transfer charge accommodating chamber 361 of the seal cup member 360 by being fitted into the opening 351 of the partitioning circular member 350, and are inserted into the igniter receiving port 362. Second fitted
The upper portion of the igniter 312b is a circular hole 352 of the section circular member 350.
It protrudes into.

The circular section 350 and the seal cup member 360
As shown in FIG. 5, the partition wall 307
Is locked by a stepped notch 306 formed on the inner peripheral surface of the base. That is, the periphery of the sectioned circular member 350 is supported by the stepped portion 306,
The seal cup member 360 is supported in contact with the section circular member 350.

The periphery of the seal cup member 360 is formed by bending in the same direction as the igniter accommodating port 362, and the bent portion 363 is formed by a groove 364 provided on the inner peripheral surface of the inner cylindrical member 304. It fits inside. Thereby, the section circular section 350
Is supported by the seal cup member 360 and the housing 3
Is prevented from moving in the axial direction. Further, by fitting the bent portion 363 of 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 engaged without any gap. I agree.

Accordingly, in the inner cylinder member 304, the ignition means accommodating chamber 308 provided on the closure shell 2 side and the second combustion chamber 305b provided on the diffuser shell 1 side are connected to the seal cup member 360. It is surely partitioned by the ignition means seal structure composed of a combination with the groove 364.

The igniter accommodating opening 362 formed in the seal cup member 360 has a skirt portion opened in a skirt shape, and the inside thereof, that is, the second igniter 312 accommodated in the accommodating opening 362 is provided.
An O-ring 381 is arranged between the second igniter 312b and the housing 362, and a seal is provided between the O-ring 381 and the second igniter 312b.

The O-ring 381 has two igniters 312
Since the second igniter 312b is also pressed against the igniter fixing member 382 for fixing the a and 312b to the single initiator collar 313, the second igniter 312b is provided with the circular hole 352 of the section circular member and the ignition of the seal cup member. It is arranged in a space defined by the container housing port 362, the O-ring 381, and the igniter fixing member 382.

Therefore, the two igniters 312a and 312b arranged on the initiator collar 313 are connected to the initiator collar 31.
The igniter is fixed to an igniter fixing member 382 which is fitted to the outside. 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, a first igniter 312a and a second igniter
An igniter having the same operation output as that of the igniter having the same operation output can be used although the size is different from that of the 312b and the operation output is different.

In the space thus partitioned, the second igniter 312b operates to seal the second heat transfer hole 319 formed in the circular hole 352 of the circular member 350. 320 bursts and 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 an igniter accommodating port 362, an O-ring 381, and an igniter fixing member 382. ) To ensure separation. Thus, the flame generated by the operation of any one of the igniters does not directly flow into the space in which the other igniters are accommodated.

In the housing 3, a gas generating agent (309a,
A coolant filter 22 for purifying and cooling the combustion gas generated by the combustion of 309b) is provided. It is covered with a short path prevention member 23 so that the combustion gas does not pass through the gap. Outside the coolant filter 22, an outer layer 24 for suppressing swelling of the filter 22 due to passage of combustion gas or the like is arranged. The outer layer 24 is formed using, for example, a laminated metal mesh body, a porous cylindrical member having a plurality of through holes in a peripheral wall surface, or a belt-shaped restraining layer formed by annularly forming a band member having a predetermined width. You can also. Further, outside the outer layer 24, the combustion gas
A gap 25 is formed so that it can pass through the entire surface of 22.

In the operation of the gas generator shown in this embodiment, the flame generated by the operation of the first igniter 312a is:
The first transfer charge 316a disposed above is ignited and burned. The flame generated by the combustion of the first transfer charge 316a is supplied to the second igniter 31 by the igniter seal structure.
It does not flow into the space where 2b is accommodated, and flows into the second combustion chamber 305b by the ignition means seal structure including the bent portion 363 of the seal cup member 360 and the groove 364 of the inner cylinder member 304. Not even. Therefore, this first transfer charge 316a
The flame generated by the combustion of the first combustion chamber 3 passes through the first heat transfer hole 317 formed in the peripheral wall of the inner cylinder member 304,
It flows into 05a, ignites and burns the first gas generating agent 309a, and generates combustion gas.

The flame generated by the operation of the second igniter 312b passes through the second heat transfer hole 319 formed in the circular hole portion 352 of the section circular member 350, and is exclusively used in the second combustion chamber 305b.
To ignite and burn the second gas generating agent 309b,
Generates combustion gas. In particular, in the gas generator according to this embodiment, the second transfer agent is not provided, and the second gas generating agent 309a is directly provided by the flame generated by the operation of the second igniter 312b. It is ignited and burned.

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, and the gap 25 Through the gas outlet 26. The seal tapes 318 and 320 closing the first and second transfer holes burst when the flame of the igniter or the combustion gas of the transfer charge passes, and the seal tape 27 closing the gas discharge port 26 has the combustion gas. Explodes when passing. Embodiment 4 FIG. 7 shows an embodiment of the airbag apparatus of the present invention in the case of including a gas generator using an electric ignition type ignition means.

This airbag device is composed of 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 in the initial stage of the gas generator operation so as to minimize impact on the occupant. ing.

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 deflected when acceleration is applied,
These semiconductor strain gauges are bridge-connected.
When acceleration is applied, the beam deflects, causing strain on the surface. 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.

The control unit 202 has an ignition determination circuit, and a signal from the semiconductor acceleration sensor is input to the ignition determination circuit. When the shock signal from the sensor 201 exceeds a certain value, the control unit 202 starts the calculation, and when the calculation result exceeds a certain value, outputs an operation signal to the igniters 312a and 312b of the gas generator 200. .

The module case 203 is made of, for example, polyurethane, and includes a module cover 205. The module case 203 houses the airbag 204 and the gas generator 200 and is configured as a pad module. When the pad module is mounted on the driver's seat side of an automobile, the pad module is usually mounted on the steering wheel 207.

The airbag 204 is formed of nylon (eg, nylon 66) or polyester, and its bag opening 206 surrounds the gas outlet of the gas generator and is fixed to the flange of the gas generator in a folded state. Have been.

When a semiconductor type acceleration sensor 201 detects a shock at the time of a car collision, the signal is sent to the control unit 202, and when the shock 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. Thereby, the igniter 12 operates to ignite the gas generating agent, and the gas generating agent burns to generate gas. This gas is blown into the airbag 204, whereby the airbag breaks the module cover 205 and bulges, forming a cushion between the steering wheel 207 and the occupant to absorb impact.

[0067]

According to the present invention, the ignition and combustion of the gas generating means in one combustion chamber prevents the gas generating means in the other combustion chamber from igniting and burning. The safety and reliability of the generator can be increased.

[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.

FIG. 6 is an exploded perspective view showing the partition wall of FIG. 5;

FIG. 7 is a configuration diagram of an airbag device of the present invention.

[Explanation of symbols]

 Reference Signs List 3 Housing 5a First combustion chamber 5b Second combustion chamber 7 Partition wall 9a First gas generating agent 9b Second gas generating agent 12a First igniter 12b Second igniter 13 Initiator color 22 Coolant filter 305a First combustion chamber 305b Second combustion chamber 307 Partition wall 309a First gas generating agent 309b Second gas generating agent 312a First igniter 312b Second igniter 313 Initiator color 350 Partition circular member 360 Seal cup member 370 ignition means accommodation chamber 382 igniter fixing member

Claims (7)

[Claims] 1. A housing having a gas discharge port including an ignition means operated by impact, and a gas generation means ignited and burned by the ignition means to generate combustion gas for inflating an airbag. A gas generator for an airbag, wherein two combustion chambers for accommodating gas generating means are provided in the housing, and a communication hole which allows the combustion chambers to communicate with each other is further provided. And
The communication hole has a tensile strength of 15 kg / mm ² or more and a thickness of 10 kg / mm ² or more.
A gas generator for an air bag, wherein the gas generator is closed with a metal sheet of about 200 μm. 2. A combustion chamber for accommodating the gas generating means is provided concentrically adjacent to the housing in a radial direction, and further provided with a communication hole which allows the combustion chambers to communicate with each other. The gas generator for an air bag according to claim 1. 3. A housing having a cylindrical shape whose axial center is longer than the outermost diameter and having a plurality of gas outlets on a peripheral wall thereof, an ignition means operated by impact, and ignition by the ignition means. A gas generator for an airbag containing gas generating means for generating combustion gas for burning and inflating the airbag, wherein the housing includes two gas generating means for storing the gas generating means. The combustion chamber is provided coaxially adjacent to the housing in the axial direction and / or the radial direction, and further provided with a communication hole that allows the combustion chambers to communicate with each other, and the communication hole has a tensile strength. Is 15kg / m
A gas generator for an airbag, wherein the gas generator is closed by a thin metal plate having a thickness of 10 m to ²⁰⁰ m and a thickness of 10 m to ²⁰⁰ m. 4. The gas generator for an air bag according to claim 1, wherein the thickness of the thin metal plate is 20 to 100 μm. 5. A combustion gas generated by the combustion of the gas generating means housed in the two combustion chambers reaches a gas outlet through a different flow path for each combustion chamber, and is housed in one combustion chamber. The gas generator for an airbag according to any one of claims 1 to 4, wherein the generated gas generating means is not directly ignited by combustion gas generated in another combustion chamber. 6. A gas generator for an air bag according to claim 5, wherein a flow path forming member is disposed in said housing to form a flow path, and combustion gas generated in one combustion chamber is directly guided to coolant means. vessel. 7. A gas generator for an airbag, an impact sensor that senses an impact to operate the gas generator, an airbag that inflates by introducing gas generated by the gas generator, and the airbag. And a module case for accommodating the airbag, wherein the gas generator for an airbag is the gas generator for an airbag according to any one of claims 1 to 6.