JP2001151070A - Gas generator for air bag, and air bag device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a gas generator that has operating performance and timing adjustable in multiphase fashion while maintaining versatility, a minimal number of seal structures and easy manufacture due to a simple structure. SOLUTION: The gas generator for an air bag includes, in a cylindrical housing longer axially than radially, two combustion chambers for storage of two ignition means operated on impact and gas generating means ignited and combusted by the ignition means. The combustion chambers are defined at both ends of the housing. Between both combustion chambers, a filter means storage chamber is provided for storage of filter means. Either combustion chamber and the filter means storage chamber communicate with each other.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas generator for an air bag suitably used for an inflatable safety system of a motor vehicle, and more particularly, to a gas generator for an air bag having a feature in an internal structure of a housing. The present invention relates to an airbag device using the same.

[0002]

2. Description of the Related Art An airbag system mounted on various kinds of vehicles such as automobiles is used when a vehicle collides at a high speed.
The purpose is to support an occupant with an airbag (bag body) that is rapidly inflated by gas, and to 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.
No., etc., in JP-A-8-207696,
A gas generator that ignites two types of gas generating agent capsules with one igniter and generates gas in two stages is regulated in US Pat. No. 4,998,751 and US Pat. No. 4,950,458. For this purpose, two combustion chambers are provided, and gas generators that generate gas in two stages by the spread of the gas generating agent have been proposed.

However, in such a gas generator, if a structure for sealing a gas generating agent contained therein is provided for each combustion chamber, the internal structure is complicated, and the size of the container is large. Has the disadvantage of increasing the cost and increasing the cost. Therefore, there is a demand for a gas generator with a reduced seal structure as much as possible.

Further, it is known that such a gas generator has a different required amount of generated gas depending on its location (or use), such as a driver seat, a passenger seat or a side collision gas generator. Have been. The adjustment of the amount of generated gas is generally adjusted by the amount of gas generating means housed in the housing. In such a case, even if the amount of the gas generating means accommodated in the housing is slightly different, if the gas generating means can be constituted by the same member, the manufacturability can be improved and the manufacturing cost can be reduced.

[0006]

SUMMARY OF THE INVENTION Accordingly, the present invention solves the above-mentioned conventional problems, has versatility, minimizes the sealing structure as much as possible, and has a simple structure and is easy to manufacture. In the early stage of operation, the occupant operates with as little impact as possible on the occupant, and the physique of the occupant (for example, a person with a high or low sitting height, an adult or a child, etc.) and its riding posture (for example, Provided is a gas generator that can arbitrarily adjust the operation output of the gas generator and the timing of the output increase so that the occupant can be safely restrained even if the posture of the gas generator is different.

[0007]

The gas generator for an air bag according to the present invention is a gas generator having two combustion chambers provided in a housing, one of the combustion chambers being a filter means accommodating chamber. The feature is that it is in communication with If any one of the combustion chambers communicates with the filter means accommodating chamber, the seal in the combustion chamber can be omitted.

That is, the gas generator for an air bag according to the present invention comprises:
In a cylindrical housing longer in the axial direction than in the radial direction, two combustion chambers accommodating two ignition means operated by impact and gas generation means ignited and burned by the ignition means are provided. Wherein the combustion chamber is provided at both ends in the housing, and a filter means accommodating chamber for accommodating a filter means is provided between the two combustion chambers. The chamber and the filter means accommodating chamber communicate with each other. In the gas generator formed as described above, by communicating any one of the combustion chambers with the filter means housing chamber, the moisture proof of the gas generating means housed in the combustion chamber and the rust prevention of the internal metal member become cylindrical. This is possible only by sealing a plurality of gas outlets formed on the peripheral wall of the housing, and the sealing mechanism in the combustion chamber can be simplified. In other words, if various sealing mechanisms are applied to the gas discharge port, such as closing the gas discharge port with a seal tape, the moisture prevention of the gas generation means in the combustion chamber communicating with the filter means storage chamber and the rust prevention of the internal metal member will be improved. Will be fulfilled.

When a cup member provided with a plurality of through holes is disposed at any end of the housing, one of the two combustion chambers provided at both ends of the housing is connected to the cup. It can be defined inside the member. In this case, by closing the through-hole with the closing member, the combustion chamber and the filter means accommodating chamber in the cup member can be defined. As a closing member for closing the through hole, for example, a stainless steel foil having a thickness of 20 to 80 μm can be used. This stainless steel foil can be attached to the inside or outside of the cup member with various adhesives or pressure-sensitive adhesives. In addition, the closing member may be ruptured by the combustion of the gas generating means housed in the combustion chamber defined inside the cup member, and may be ruptured by the combustion chamber communicated with another combustion chamber, i.e., the filter means housing chamber. Depending on the combustion of the gas generating means, those which do not burst can be used as appropriate.

[0010] The plurality of through holes formed in the cup member,
Preferably, it is formed on the peripheral wall. This means that the flame / gas discharged from the other combustion chamber directly hits the bottom surface of the cup member through the shaft space of the filter means. In this way, a through hole is formed in the peripheral wall of the cup member. This is because it is possible to avoid direct injection of a flame or gas from another combustion chamber. Further, when a through hole is formed in the peripheral wall of the cup member, a flow path is formed between the outer peripheral surface of the cup member and the inner peripheral surface of the housing, the flow path being connected from the through hole to the filter means housing chamber. Is preferred.

A partition member having a plurality of through holes can be arranged between the filter chamber and the combustion chamber communicating with the filter chamber. The partition member has a function of preventing the gas generating means housed in the combustion chamber from moving into the filter means housing chamber. However, this partition member does not have a function of adjusting the internal pressure in the combustion chamber communicating with the filter means housing chamber. Adjustment of the combustion pressure in the housing is adjusted exclusively by the opening area of the gas outlet. Therefore, in the partition member used for such a purpose, the through hole is smaller than the gas generating means accommodated in the combustion chamber, and the total opening area is the total opening area of the gas discharge port. It is formed larger than. The total area of the opening of the partition member is preferably 1.5 times or more the total area of the opening of the gas discharge port. In this specification, the total opening area of the partition member refers to the sum of the opening areas of all the through holes formed in the partition member, and the total opening area of the gas discharge port is formed in the housing. The sum of the opening areas of the gas outlets.

The partition member needs to have a strength enough to withstand the internal pressure of the combustion chamber communicating with the filter means accommodating chamber (internal pressure during combustion of the gas generating means). In order to secure such strength, for example, it may be formed in a curved shape so as to protrude toward the combustion chamber communicating with the filter means accommodating chamber. The partition member formed in such a shape is hardly deformed even by the combustion pressure of the gas generating means in the combustion chamber.

The openings at both ends of the cylindrical housing must be closed. Therefore, in the present invention, the housing is constituted by a cylindrical diffuser shell having a plurality of gas outlets on the peripheral wall and a closure shell closing both ends of the peripheral wall. The plurality of gas outlets formed in the peripheral wall of the diffuser shell are formed in an area where a filter means accommodating chamber described later is provided. Further, the closure shell can be constituted by an annular portion and a cylindrical portion projecting outward in the axial direction of the housing, and an ignition means can be accommodated inside the cylindrical portion. Since the ignition means is accommodated in a cylindrical portion protruding outside the housing, a maximum space can be secured in the combustion chamber. If the cylindrical portion is projected outward in the axial direction of the housing and a screw is formed around the cylindrical portion, the gas generator can be attached to the module by screwing a nut to the cylindrical portion.

An inward flange-shaped plate member can be provided in the combustion chamber provided in the cylindrical housing. By arranging the plate member so as to be slidable in the axial direction of the housing, the accommodation amount of the gas generating means can be adjusted. For example, the plate member can be formed so as to be fitted in the combustion chamber and function to press the gas generating means housed in the combustion chamber against the filter means housing chamber side, that is, the partition member side. . Accordingly, even when the storage amount of the gas generating means is slightly changed, the gas generating means is sandwiched and fixed between the plate member and the partition member, so that damage due to vibration is prevented. The plate member to be fitted into the combustion chamber is realized by, for example, forming a cylinder having an inward flange. In the plate member formed in such a shape, the gas generating means housed in the combustion chamber can be pressed and / or held on the filter means housing chamber side by the flange portion.

In particular, in at least one of the plurality of combustion chambers, the ignition means reliably ignites and burns the gas generation means even if the capacity of the gas generation means is changed. A transfer tube having a plurality of transfer holes formed in the peripheral wall is disposed so as to extend in the axial direction, and the end of the transfer tube is connected to the internal space of the closure shell tubular portion in which the ignition means is accommodated. It is desirable to connect to The heat transfer tube may have a structure such that it passes through the center opening of the plate member and protrudes into the accommodation space of the gas generating means, and has a plurality of heat transfer holes formed in the heat transfer tube. It is preferable that a part or the whole is in the accommodation space of the gas generating means. By forming in this way,
The flame of the igniting means passes through the igniting tube without being interrupted by the plate member, is ejected from the igniting hole of the peripheral wall, and can ignite and burn the gas generating means existing around the igniting means.

The gas generating means accommodated in each combustion chamber includes:
The combustion gas generated by the combustion is used to inflate the airbag that restrains the occupant. 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. Further, in that the two combustion chambers provided in the housing are exclusively chambers for accommodating gas generating means, the ignition means includes a transfer charge,
A space in which the explosive is defined (hereinafter, referred to as “accommodation room”).
Even if it is accommodated in the combustion chamber, the chamber for accommodating the transfer charge and the combustion chamber for accommodating the gas generating means can be clearly distinguished.

Examples of such a gas generating means include azide-based gas generating agents based on inorganic azides, for example, sodium azide (sodium azide), and non-azide-based gas generating devices not based on inorganic azides. Agents can be used. However, in consideration of safety, a non-azide gas generating agent is desirable. Such non-azide gas generating compositions include, for example, those containing, as main components, a nitrogen-containing organic compound such as tetrazole, triazole, or a metal salt thereof and an oxygen-containing oxidizing agent such as an alkali metal nitrate; triaminoguanidine nitrate , Carbohydrazide, nitroguanidine, etc. as fuel and nitrogen source, and various kinds of compositions such as nitrate, chlorate, perchlorate, etc. of alkali metal or alkaline earth metal as oxidizing agent may be used. it can. Other gas generating means
It is appropriately selected according to the requirements such as the burning rate, non-toxicity, burning temperature and decomposition start temperature.

For the two combustion chambers formed in the housing, gas generating means having different combustion rates for each combustion chamber can be used. In this case, in addition to using an inorganic azide such as sodium azide or a non-azide such as nitroguanidine as a fuel and a nitrogen source for each combustion chamber, a gas generating means having a different composition or composition ratio itself is used, and a pellet or wafer is used. A gas generating means in which the shape of the composition is changed, such as the shape, hollow columnar shape, disk shape, single-hole shape or porous shape, or the surface area is changed depending on the size of the molded body, etc. . 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. Further, an arrangement in which one hole is provided at the center and 18 holes are provided around the center is also conceivable. The number and arrangement of these holes are determined by the ease of manufacture of the gas generating means, and the balance between manufacturing cost and performance.
There is no particular limitation.

The filter means accommodating chamber provided between the two combustion chambers is provided with a filter means for cooling the combustion gas generated by the combustion of the gas generating means. The filter means is provided in the housing for the purpose of cooling and / or purifying combustion gas generated by 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 or the like obtained by forming a wire mesh made of an appropriate material into an annular laminate and compression-molding the wire mesh may be used. This filter means can be formed as a double structure having different pressure losses between the inside and the outside, and can also have a function of protecting the filter means inside and a function of suppressing the bulging of the filter means outside. . Further, the filter is not limited to a wire mesh formed using such a wire, but a wire formed using an expanded metal in a cylindrical shape can be used as the filter means. The swelling of the filter means can be suppressed by supporting the outer periphery thereof with an outer layer made of a laminated metal mesh, a porous cylinder, an annular belt, or the like.

The filter means is supported by the filter means support member, and is fixed in the housing after securing a predetermined gap between the filter means and the inner peripheral surface of the housing. The gap secured between the outer peripheral surface of the filter means and the inner peripheral surface of the housing avoids the situation where the combustion gas concentrates near the gas outlet when passing through the filter means, and realizes the entire use of the filter means.

The housing further houses ignition means for sensing the impact and operating 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.

[0023]

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 showing a first embodiment of a gas generator for an airbag of the present invention.

In this gas generator, a housing 3 is formed by combining and integrating a cylindrical diffuser shell 1 having a gas discharge port 4 and a closure shell 2 for closing an end opening of the diffuser shell 1. I have. Inside the housing 3, combustion chambers 6 for accommodating a gas generating agent 5 as gas generating means are formed at both ends in the axial direction (that is, on the closure shell side). In the vicinity of the center of 3, a filter means accommodating chamber 8 for accommodating the cylindrical filter means 7 is provided. In the present embodiment, for the sake of explanation, the combustion chamber on the right side of the drawing is the first combustion chamber 6a, and the combustion chamber on the left side of the drawing is the second combustion chamber.
6b. The first combustion chamber 6a is in communication with the filter means accommodation chamber 8.

The diffuser shell 1 is formed using a cylindrical straight tube, and a plurality of gas outlets 4 are formed in a peripheral wall in a range where the filter means accommodating chamber 8 is provided. The gas outlet 4 is closed with a sealing tape 9 made of aluminum for the purpose of preventing moisture. The gas outlet 4 has a function of adjusting the internal pressure of the housing 3 when the gas generating agent 5 is burned. It is determined based on the characteristics and the like.

The closure shell 2 comprises an annular portion 21 connected to the opening end of the diffuser shell 1 and a tubular portion 22 integrally connected to the central opening of the annular portion. The cylindrical portion 22 protrudes outward in the axial direction of the housing 3 and houses an ignition means 26 in its internal space. In the present embodiment, the first closure shell 2a that closes the end opening on the first combustion chamber 6a side has a cylindrical portion 22a and an annular portion 21a that is connected to an end of the cylindrical portion 22a in a flange shape. The second closure shell 2b for closing the end opening on the second combustion chamber 6b side has a cylindrical portion 22b and an annular portion orthogonal to the peripheral wall of the cylindrical portion 22b in a flange shape. 21a. Each tubular part 2 of the first and second closure shells 2a, 2b
The first ignition means 26a and the second ignition means 26b are accommodated in 2a and 22b, respectively.
An igniter 10 housed in 1 and ignited by the igniter 10
It is composed of a transfer charge 12 to be burned. The cylindrical portion 22a of the first closure shell 2a is closed by a cap member 14 connected to the end of the heat transfer tube 13, and the cylindrical portion 22b of the second closure shell 2b is connected to the second combustion chamber. The 6b side is closed by a porous disc-shaped lid member 16 having a plurality of heat transfer holes 15b. Fire tube 13 connected to cap member 14
Has a plurality of heat transfer holes 15a formed in its peripheral wall, and its internal space communicates with the inside of the cylindrical portion 22a of the first closure shell 2a.

In the present embodiment, the periphery of the annular portion 21b forming the second closure shell 2b is formed so as to project outward in the radial direction of the diffuser shell 1. Thus, the annular portion 21b can function as a flange when this gas generator is mounted on a module. Also, the cylindrical portion of the first closure shell 2a
A thread groove (for example, the diameter of the cylindrical portion 22a is 22 mm)
, A thread groove having a pitch of 1.0 mm) is formed. As a result, if a nut is combined with the cylindrical portion 22a, it can function as a stud bolt when attaching the gas generator to the module case.

The first combustion chamber 6a formed on the right side of the housing 3 in the drawing is partitioned from the filter means accommodating chamber 8 by a partition member. In the present embodiment, a baffle member 17 that is convexly curved toward the first ignition means 26a is used as the partition member. . This baffle member
Reference numeral 17 has a function of preventing movement of the gas generating agent 5a to the filter means housing chamber 8 side, and sends the working gas generated by the combustion of the gas generating agent 5a to the filter means housing chamber 8, so that the combustion chamber 6a A plurality of through-holes 18a are formed to communicate the filter and the filter means accommodation chamber 8. This through hole 18a is opened without being closed by a seal tape or the like. Alternatively, as another form, the through hole may be closed with a seal tape or the like, and the seal tape may be ruptured by burning of a gas generating agent or the like, so that the two chambers can communicate with each other. That is, the first combustion chamber 6a and the filter means accommodating chamber 8 are always in communication or can be in communication. Thereby, the first combustion chamber 6a
Moisture proof of the gas generating agent 5a contained therein and rust prevention of the internal metal member can be achieved only by sealing the plurality of gas outlets 4 formed on the peripheral wall of the cylindrical housing 3, thereby simplifying the sealing mechanism. be able to. In the first combustion chamber 6a, a perforated cylindrical first gas generating agent 5a is accommodated, and this gas generating agent 5a is an inward flange-shaped plate through which a heat transfer tube 13 passes through a central opening. It is supported by a member 23. The peripheral wall 19 of the plate member 23 is fitted inside the combustion chamber 6a, and the flange 20 connected to the peripheral wall 19 supports the gas generating agent 5a. Thereby, the movement of the gas generating agent 5a is prevented, and it is possible to avoid a situation where the gas generating agent 5a is damaged by vibration or the like. This plate member 23 is a housing
3, the gas generating agent 5a can be reliably supported, pressed, and / or held even when the capacity of the gas generating agent 5a is changed because it is slidably fitted in the axial direction. it can.

The gas generating agent 5a accommodated in the combustion chamber 6a is supported by the plate member 23, and the flame of the ignition means 26a is surely blown into the combustion chamber 6a by the transmission tube 13, so that the combustion chamber 6a Even when the amount of the gas generating agent 5a stored therein changes, the gas generating agent 5a is reliably ignited and burned.

The baffle member 17 having the through hole 18a supports the gas generating agent 5a housed in the first combustion chamber 6a and prevents the gas generating agent 5a from moving into the filter means housing chamber 8. Further, the baffle member 17 does not have a function of adjusting the internal combustion pressure in the first combustion chamber 6a. Therefore, the through hole 18a is adjusted so that the inner diameter is smaller than the first gas generating agent 5a, and the total area of the opening is larger than the total area of the opening of the gas outlet 4.

A second combustion chamber 6b formed on the left side of the housing 3 in the drawing is formed inside a cup member 24 having a plurality of through holes 18b formed in a peripheral wall. Is closed by a closing member 25 formed using a stainless steel foil having a thickness of about 40 μm. The closing member 25 can be adhered by, for example, an adhesive or an adhesive. This through hole 18b can be formed in the bottom of the cup member 24 (that is, on the filter means housing chamber 8 side), but in order to prevent direct injection of flame and gas generated in the first combustion chamber 6a. Is preferably formed on the peripheral wall portion 33 as in this embodiment. As shown in the present embodiment, when the through hole 18b is formed in the peripheral wall portion 33 of the cup member 24, the through hole is provided between the outer peripheral surface of the cup member 24 and the inner peripheral surface of the housing 3. Channel 27 leading from 18b to filter means storage chamber 8
To form For example, as shown in the present embodiment, the flow path 27 between the inner peripheral surface of the housing and the outer peripheral surface of the cup member 24 increases the outer diameter of the cup member 24 from the portion where the through-hole 18b is formed to the filter means housing chamber. Small on the 8 side, housing 3
It can be formed by securing a space 27 between the inner peripheral surface and the outer peripheral surface of the cup member 24. This second combustion chamber 6b
Contains a single-hole cylindrical first gas generating agent 5b, and is supported by a plate member 23 housed in the second combustion chamber 6b, like the first gas generating agent 5a.

In the present embodiment, a gas generating agent having a different shape from the first gas generating agent 5a and the second gas generating agent 5b is used. Of course, it is possible to use the same gas generating agent for both combustion chambers 6a, b, but as shown in the present embodiment, if the shape of the gas generating agent differs for each combustion chamber,
The operation performance of the gas generator (that is, the deployment pattern of the airbag) can be variously adjusted. In addition, as in the present embodiment, if each combustion chamber 6a, b contains a gas generating agent having at least one or more different combustion speed, composition, composition ratio, and amount even if they have the same shape, the The operating performance of the generator can be variously adjusted.

The filter means accommodating chamber 8 accommodates a cylindrical filter means 7. In the present embodiment, one formed by winding expanded metal in multiple layers is used. Other filter means
7 is formed by using a laminated wire mesh, and has a cooling effect that has both the cooling effect of combustion gas and the function of collecting combustion residue.
It is also possible to use filters. The filter means 7 is supported and fixed by a filter means support member 28, and a gap 32 having a predetermined width is secured between the outer peripheral surface and the inner peripheral surface of the housing 3. In the present embodiment, the filter means support member 28 has an inner peripheral wall 29 which is fitted inside the central opening of the filter means 7, and extends on the opposite side to the inner peripheral wall 29 and is fitted inside the housing inner peripheral surface. Outer peripheral wall 30 and an annular portion 31 connecting the inner peripheral wall 29 and the outer peripheral wall 30, and the filter means 7 is provided between the filter means support members 28 fitted inside the housing 3. The inner peripheral surface is supported and fixed by the filter means support member 28. In addition, the gap 32 secured between the outer peripheral surface of the filter means 7 and the inner peripheral surface of the housing 3 functions as a gas flow path, and when the combustion gas passes through the filter means 7, it concentrates near the gas outlet 4. Avoid the situation that you do. In the present embodiment, the filter means support member 28 provided on the first combustion chamber 6a side is supported and fixed by an embossed structure or a press fit provided on the housing 3 on the outer peripheral surface.

The operation pattern of the gas generator shown in FIG.

First, when the first ignition means 26a operates,
The flame passes through the transfer tube 13 and blows out from the transfer hole 15a into the first combustion chamber 6a. This flame is the first gas generating agent
5a is ignited and burned to generate combustion gas. The working gas generated by the combustion of the first gas generating agent 5a passes through the through hole 18a of the baffle member 17 and reaches the filter means accommodating chamber 8 as it is. Then, while passing through the filter means 7, it is purified and cooled and flows into the gap 32, and the sealing tape
It breaks 9 and is discharged from gas outlet 4. The second gas generating agent 5b accommodated in the second combustion chamber 6b, due to the through-hole 18b of the cup member 24 being closed by the rupture member, depends on the combustion of the first gas generating agent 5a. It does not ignite or burn with the generated gas. The second gas generating agent 5b is ignited and burned by the operation of the second ignition means 26b. However, when an auto-ignition material (AIM) that ignites and burns by the heat of combustion (conduction heat) of the first gas generating agent 5a transmitted from the housing 3 or the like is disposed in the second combustion chamber 6b, It is possible to ignite and burn by the combustion of the auto-ignition material.
As such an auto-ignition material, for example, nitrocellulose or the like can be used, and is usually arranged so as to ignite and burn with a delay of 100 ms or more after the first ignition means 26a operates.

The second ignition means 26b is provided with a first ignition means 26a.
Or at a predetermined interval after the operation of the first ignition means 26a. As a result, the ignition timing of the two ignition means 26a, b is adjusted, that is, the first ignition means 26a
The output form (operating performance) of the gas generator is arbitrarily adjusted depending on whether the second ignition means 26b is operated after the operation of or the first ignition means 26a and the second ignition means 26b are simultaneously operated. 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.

When the second ignition means 26b is activated, the flame is blown out from the heat transfer hole 15b of the cover member 16 into the second combustion chamber 6b to ignite and burn the second gas generating agent 5b. Generate gas. The working gas is released from the through-hole 18b of the cup member 24 by peeling off the closing member 25, and
It reaches the filter means accommodating chamber 8 through a flow path 27 provided between the housings. Thereafter, similarly to the combustion gas generated from the first gas generating agent 5a, the gas passes through the filter means 7 and is discharged from the gas discharge port 4. Embodiment 2 FIG. 2
Shows an embodiment of the airbag device of the present invention in the case of including a gas generator using 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 judgment circuit, and a signal from the semiconductor acceleration sensor is input to the ignition judgment circuit. When the shock signal from the sensor 201 exceeds a certain value, the control unit 202 starts the calculation. When the calculation result exceeds a certain value, the control unit 202 outputs an operation signal to the igniter 10 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 made of nylon (for example, nylon 66) or polyester, and its bag opening 206 surrounds the gas outlet of the gas generator and is fixed to the gas generator flange in a folded state. Have been.

When an impact is detected by the semiconductor acceleration sensor 201 at the time of an automobile 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 igniter 10 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.

[0044]

According to the present invention, the overall size of the container is suppressed, and the container has a simple structure and is easy to manufacture. Even if the occupant operates without giving the occupant, and the physique of the occupant (for example, a person with a high or low sitting height, an adult or a child, etc.), or the riding posture (for example, the posture of clinging to the steering wheel) is different, The gas generator is capable of arbitrarily adjusting the operation output of the gas generator and the timing of increasing the output so that the gas generator can be safely restrained.

In the gas generator according to the present invention, the seal structure can be minimized by connecting any of the combustion chambers to the filter means accommodating chamber. Further, in a gas generator including a structure in which a heat transfer tube and a plate member are combined, the amount of a gas generating agent accommodated in a combustion chamber can be appropriately changed, and a general-purpose gas generating agent can be used. A vessel is provided.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing one embodiment of a gas generator according to the present invention.

FIG. 2 is a configuration diagram of an airbag device of the present invention.

[Explanation of symbols]

 Reference Signs List 1 diffuser shell 2a first closure shell 2b second closure shell 3 housing 4 gas outlet 5a first gas generating agent 5b second gas generating agent 6a first combustion chamber 6b second combustion chamber 7 filter means Reference Signs List 8 filter means accommodation chamber 9 seal tape 13 fire tube 17 baffle member 18 through hole 23 plate member 24 cup member 25 closing member 26a first ignition means 26b second ignition means 28 filter means support member

Claims (11)

[Claims] In a cylindrical housing longer in the axial direction than in the radial direction, two ignition means operated by impact are contained and housed, and two gas generating means ignited and burned by the ignition means are housed. An airbag gas generator provided with a combustion chamber, wherein the combustion chamber is provided at both ends in the housing, and a filter means accommodating chamber for accommodating a filter means is provided between the two combustion chambers. ,
A gas generator for an airbag, wherein any one of the combustion chambers and the filter means accommodating chamber communicate with each other. 2. The cylindrical housing is provided with a plurality of gas outlets on a peripheral wall thereof, and the inside of a combustion chamber communicating with the filter means accommodating chamber is protected from moisture by a seal tape closing the gas outlet. The gas generator for an airbag according to claim 1, wherein 3. A combustion chamber, wherein one of the two combustion chambers is defined inside a cup member having a plurality of through holes, and the through holes are closed by a closing member. Item 3. The gas generator for an airbag according to Item 1 or 2. 4. A plurality of through holes are formed in a peripheral wall of a cup member, and between the outer peripheral surface of the cup member and an inner peripheral surface of the housing, the through holes are connected to the filter means accommodating chamber. The gas generator for an airbag according to claim 3, wherein a flow path is formed. 5. The gas generator for an air bag according to claim 3, wherein the closing member is a stainless steel foil having a thickness of 20 to 80 μm. 6. An inward flange-shaped plate member is disposed in the combustion chamber provided in the cylindrical housing, and the plate member is fitted in the combustion chamber and accommodated in the combustion chamber. The gas generator for an airbag according to any one of claims 1 to 5, wherein the generated gas generating means is pressed and / or held toward the filter means housing chamber. 7. The cylindrical housing includes a cylindrical diffuser shell having a plurality of gas outlets on a peripheral wall, and a closure shell closing both ends of the peripheral wall. The gas generator for an airbag according to any one of claims 1 to 6, comprising an annular portion and a cylindrical portion protruding outside the housing, wherein an ignition means is accommodated inside the cylindrical portion. . 8. A combustion tube having a plurality of heat transfer holes formed in a peripheral wall is housed in at least one of the plurality of combustion chambers. The gas generator for an air bag according to any one of claims 1 to 7, wherein the housing extends in an axial direction of the housing, and an end thereof is connected to an internal space of a tubular portion of the closure shell in which the ignition means is accommodated. . 9. The airbag according to claim 1, wherein the filter chamber and the combustion chamber communicating with the filter chamber are partitioned by a partition member having a through hole. For gas generator. 10. The partition member is curved in a convex shape inside the combustion chamber communicating with the filter means accommodating chamber.
A gas generator for an airbag as described in the above. 11. A gas generator for an airbag, an impact sensor that senses an impact to operate the gas generator, an airbag that expands by introducing gas generated by the gas generator, and the airbag. And a module case for accommodating the
An airbag device, wherein the gas generator for an airbag is the gas generator for an airbag according to any one of claims 1 to 10.