JP2003025948A - Gas generator for air bag and air bag system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a gas generator enhancing an ignition/burning property of a gas generation agent. SOLUTION: A first combustion chamber 7a and a second combustion chamber 7b are provided in a housing 3. An arrangement position of partition member 5 at a bulkhead member 4 is formed in a range that a distance Lc from a center in an axial direction of the bulkhead member 4 becomes a quarter or lower of an average length Ld in an axial direction of the bulkhead member.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an airbag gas generator which is installed in a vehicle and is preferably used in an airbag for protecting an occupant from an impact, and an airbag device using the same.

[0002]

2. Description of the Related Art An air bag system is installed in an automobile or the like for the purpose of protecting an occupant from a shock at the time of a collision, and this causes gas to be rapidly generated by the operation of a gas generator for an air bag. It is formed as an inflatable bag.

In a general gas generator, when the ignition means is activated by impact, this ignites and burns the gas generating agent to generate a high temperature and high pressure gas, and the generated gas is discharged from the gas outlet to an airbag ( It is formed so as to squirt into the bag body.

Therefore, it is necessary to adjust the operating performance of the gas generator in order to adjust the inflating condition of the airbag. To adjust the operating performance of this gas generator, the combustion condition of the gas generating agent is optimized. Need to be. Therefore, it is desirable that the gas generating agent with which the combustion chamber is filled is ignited and burned effectively and reliably by the operation of the ignition means.

On the other hand, the ignition means for igniting and burning the gas generating agent is constituted only by an igniter operated by an operation signal, and further, the igniter is ignited and burned by the operated igniter. Sometimes combined with transfer charges. Further, the combustion chamber in which the gas generating agent is housed,
Various positions, shapes, volumes, etc. are designed according to the shape of the housing and arrangement of necessary constituent members, and various shapes and compositions of the gas generating agent filled therein are selected.

Therefore, in manufacturing the gas generator, it is necessary to adjust the internal structure of the gas generator for the purpose of optimizing the operating performance of the gas generator.

However, the gas generators conventionally provided still have room for improvement from the viewpoint of improving the ignitability of the gas generating agent.

[0008]

SUMMARY OF THE INVENTION Therefore, according to the present invention, by improving the internal structure of a gas generator, the ignition / combustibility of the gas generating agent is improved, and by extension, the operation performance is improved. To provide a container.

[0009]

In the gas generator for an air bag of the present invention, the shape and position of the partitioning member for partitioning the ignition device accommodating chamber are adjusted to adjust the gas generating agent in the combustion chamber. It is a gas generator in which the ignition start position is adjusted, and as a result, the ignition / combustibility of the gas generating agent is optimized.

That is, in the gas generator for an air bag of the present invention, a partition member having an annular peripheral wall is arranged in a housing having a gas discharge port, and the first gas generating agent is provided on the outer side in the radial direction of the partition member. With the first combustion chamber to accommodate,
A disk-shaped partition member is arranged inside the partition member, and the inside of the partition member is partitioned into a second combustion chamber that houses the second gas generating agent and an ignition means housing chamber that houses the ignition means. In the gas generator for an airbag, wherein the second combustion chamber and the ignition means accommodating chamber are arranged adjacent to each other in the axial direction of the partition member via the partition member, and on the annular peripheral wall. Is provided with a flame transfer hole that allows the ignition means accommodating chamber and the first combustion chamber to communicate with each other, and the partition member in the partition member is arranged at a distance from the axial center of the partition member in the axial direction of the partition member. It is characterized in that it is formed in a range of 1/4 or less of the average length.

The partition wall member has a space inside the housing.
It is divided into more than one chamber and is formed with at least an annular peripheral wall. Such a partition member can be formed in, for example, a cylindrical shape or a cylindrical shape with a lid.

Further, the partition member axially adjoins two chambers inside the partition member, that is, a second combustion chamber containing the second gas generating agent and an ignition means containing chamber containing the ignition means. This is for the purpose of forming a disc-like shape that extends in the radial direction of the annular peripheral wall. From the viewpoint of its function, such a partition member is preferably formed in a shape that axially closes the inside of the partition member, for example, a horizontal cross-sectional shape inside the partition member.

According to the above-mentioned gas generator, in the so-called multistage gas generator in which two combustion chambers are provided in the housing and the gas generating agent contained in each chamber can be burned at different timings. The volume of the container housing can be minimized and the ignitability of the first gas generating agent can be improved.

That is, the first gas generating agent contained in the first combustion chamber is ignited and burned by the flame of the ignition means ejected from the flame transfer hole, and the first gas generating agent in the first combustion chamber is The overall combustion condition also differs depending on where the combustion is started, such as near the center or near the end of the first combustion chamber.

Therefore, in the present gas generator, the inside of the partition member is divided into two chambers (the second combustion chamber and the ignition device accommodating chamber) by the partition member, and both chambers are adjacent to each other in the axial direction of the partition member. The partition member is arranged in the partition member so that the distance from the axial center of the partition member is not more than ¼ of the axial average length of the partition member.
This makes it possible to increase the axial length of the ignition device accommodating chamber and provide a fire transfer hole that allows the ignition device accommodating chamber and the first combustion chamber to communicate with each other, near the axial center of the partition member.

The fire transfer hole is formed near the center of the partition member in the axial direction, preferably in a range where the distance from the center of the partition member in the axial direction is not more than ¼ of the average length in the axial direction of the partition member.
Combustion of the first gas generating agent can be improved by starting combustion from the gas generating agent present in the center of the first combustion chamber in the axial direction.

Further, by making the axial length of the ignition means accommodating chamber long, it is possible to form the flame transfer hole at an arbitrary position, and as a result, the combustion starting position of the gas generating agent in the first combustion chamber. It is also possible to arbitrarily adjust (that is, the formation position of the flame transfer hole) in a wide range.

This partition member is provided with a recessed portion which is recessed in its thickness direction on the surface on the side of the ignition means accommodating chamber, and in this recessed portion a part of the ignition means which operates due to receipt of the operation signal is provided. It is desirable to house it. When the ignition means includes an igniter that receives an actuation signal and a transfer charge that is ignited and burned by the operation of the igniter, the transfer charge can be housed in the recess. This transfer charge can be placed in the recess after being filled in a container made of resin or metal. However, the container containing the transfer charge should be formed so as to be capable of bursting at least by the operation of the igniter, and also from this viewpoint, the material, thickness and the like should be selected. The amount of transfer charge is an important factor related to the operating performance of the gas generator, but in this gas generator, if the recess is formed large in the width direction of the partition member, a sufficient amount of transfer charge will be transmitted. Gunpowder can be placed. In this case, the depth of the recess can be suppressed, and by adjusting the width and depth of the recess, the flame generated by the operation of the igniter can be spread over the entire transfer charge.
By disposing the electric ignition type igniter constituting the ignition means in contact with or directly facing the container containing the transfer charge, the transfer charge can be reliably ignited / burned.

As described above, when the partition member is provided with a recessed portion in the thickness direction on the surface of the partitioning member on the ignition means accommodating chamber side, and a transfer charge or the like is disposed in this recessed portion, the gas generator operates. The upper surface of the partition member, which is located on the second combustion chamber side, can be formed flat without projecting to the second combustion chamber side while arranging a required amount of transfer charge. As a result, the second combustion chamber can be formed as a cylindrical space, that is, a cylindrical space by the inner surface of the housing ceiling portion, the inner surface of the partition member, and the upper surface of the partition member, and thus the second combustion chamber can be formed. The combustion chamber can be formed as short as possible in the axial direction while ensuring a sufficient space volume.

Further, it is desirable to form the flame transfer hole at a height position facing the transfer charge, because the flame generated by the combustion of the transfer charge can be discharged smoothly.

When the ignition means includes two electric ignition type igniters, each igniter has a different space defined in the ignition means accommodating chamber in order to operate the igniters separately. It is desirable to place it in. in this case,
The space in which any one of the ignition means exists is formed so as to be able to communicate with the second combustion chamber by a communication hole formed in the thickness direction of the partition member, so that the flame of the igniter ejected from the communication hole is formed. For example, the second gas generating agent in the second combustion chamber can be ignited.

As a method of arranging the partition member inside the partition member, for example, a member for locking the partition member by notching the inner peripheral surface of the partition member in a stepwise manner in the circumferential direction or forming a groove is provided. It is possible to form a stop portion and support the peripheral edge of the partition member with this locking portion. In this case, if a claw portion that spreads in a hakama shape is provided on the peripheral wall surface of the partition member and the claw portion is fitted into the locking portion, it is possible to prevent the partition member from returning backward, and the partition member and the partition member. A sealing effect between and can also be realized. Then, if the peripheral edge of the partition member is also fitted into the locking portion, the partition member can be reliably fixed by the peripheral edge and the claw portion. That is, in the partition member thus formed, since the tip of the claw portion is inserted into the groove portion, the partition member can be easily and surely mounted in the partition member, and a seal between the partition member and the partition member is realized. be able to.

By forming the partition member as described above, it is possible to avoid the situation in which the partition member projects toward the second combustion chamber while securing the necessary transfer charge accommodation space. That is, the second combustion chamber can suppress the axial length as much as possible while ensuring the space necessary for the operation of the gas generator.
Therefore, the partition member can be arranged at a sufficient distance from the hem of the partition wall member, and the position of the flame transfer hole (combustion start position of the first gas generating agent) can be arbitrarily adjusted. . And if this transfer hole is formed in the vicinity of the center in the axial direction of the first combustion chamber, the flame of the transfer hole ejected from the transfer hole can be spread over the entire first combustion chamber,
Thereby, the ignition and combustibility of the first gas generating agent contained in the first combustion chamber can be improved, and the gas generator can exhibit desired operating performance.

An elastic support member for supporting the second gas generating agent may be arranged in the second combustion chamber. The elastic supporting member can be formed as a member having an elastic member and a flat circular plate-shaped supporting surface that is accommodated so as to spread in the radial direction of the second combustion chamber. As the elastic member, various springs such as a coil spring and a leaf spring can be used. In particular, if a disc spring is used, the disc spring can be easily combined with the supporting surface, and as a result, the gas generator can be easily manufactured and the cost can be reduced.

In the gas generator of the present invention, constituent elements other than the above, for example, a gas generating agent, a coolant means (or a filter means) for purifying or cooling the gas generated by the combustion of the gas generating agent, Alternatively, a known technique can be used for the plate member, the cushion member, and the like for supporting the gas generating agent.

The air bag gas generator described above is housed in a module case together with an air bag (bag body) which is inflated by introducing gas generated in the gas generator, thereby forming an air bag device. In this airbag device, the gas generator operates in conjunction with the impact detected by the impact sensor, and the combustion gas is discharged from the gas discharge port of the housing. This combustion gas flows into the air bag, whereby the air bag ruptures the module cover and inflates to form a shock absorbing cushion between the hard structure in the vehicle and the occupant.

[0027]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, a gas generator for an air bag of the present invention will be described based on an embodiment shown in the drawings.

FIG. 1 is a vertical cross-sectional view showing a preferred embodiment of a gas generator for an air bag according to the present invention. In particular, the gas generator of this aspect has a structure suitable for being arranged on the driver's side. ing.

This gas generator comprises a diffuser shell 1 having a gas discharge port 10 and a closure shell 2 which forms an internal accommodation space together with the diffuser shell 1 inside a housing 3 having a substantially cylindrical shape. The tubular member 4 is arranged. The inner cylinder member 4 corresponds to the partition wall member of the present invention, and the peripheral surface thereof corresponds to the annular peripheral wall.

In the present embodiment, this inner cylinder member 4
Is arranged so that its skirt portion 42 extends below the diffuser shell 1 and is exposed to the outside of the housing 3.
The inner cylinder member 4 may be integrally formed with an inward or outward flange-shaped connection portion at its upper end, that is, the end portion on the side to be joined to the inner surface of the diffuser shell 1. In this case, the peripheral surface serves as an annular peripheral wall, and the partition member can be formed by including the flange-shaped connecting portion.

An annular first combustion chamber 7a for accommodating the first gas generating agent 9a is provided on the outer side of the inner cylinder member 4 in the radial direction, and a housing is provided on the outer side of the first combustion chamber 7a in the radial direction. An annular coolant / filter 18 is arranged after a predetermined gap is secured between the inner peripheral surface of the inner peripheral surface 3 and the inner peripheral surface of the inner peripheral surface 3. The coolant / filter 18 has a function of cooling and purifying the working gas generated by the combustion of the gas generating agent,
It can be formed by using a laminated wire mesh or the like. That is, the first combustion chamber is provided outside the inner tubular member 4 and inside the coolant filter 18.

Inside the inner cylinder member 4, there is arranged a disk-shaped partition member 5 that spreads in the radial direction of the inner cylinder member 4, and this partition member 5 is formed inside the inner cylinder member 4. The space is divided into two chambers that are adjacent to each other in the axial direction. That is,
In the present embodiment, the inner side of the inner cylinder member 4 is partitioned into a second combustion chamber 7b for containing the second gas generating agent 9b and an ignition means accommodating chamber 6 for accommodating the ignition means. Of these, the ignition means accommodating chamber 6 is provided on the skirt portion 42 side of the inner cylinder member 4, and the second combustion chamber 7b is provided on the opposite side of the ignition means accommodating chamber 6 separated by the partition member 5.

As shown in FIG. 2, the partition member 5 for partitioning the two chambers has a substantially disk shape as a whole, and the upper surface existing on the second combustion chamber 7b side is formed flat. Therefore, the second combustion chamber 7b is formed as a cylindrical space defined by the inner surface of the diffuser shell 1, the inner peripheral surface of the inner tubular member 4 and the upper surface of the partition member 5, and the second combustion chamber is necessary and sufficient. It is possible to make the length as short as possible in the axial direction while ensuring the space volume. This means that the ignition means accommodating chamber can be secured long in the axial direction at the same time.

On the peripheral surface of the partition member 5, there is formed a claw portion 51 that spreads in a hakama shape toward the rear surface side (that is, the skirt portion 42 side of the inner tubular member). The claw portions 51 may be formed over the entire peripheral surface of the partition member 5, or may be formed in a dotted pattern at regular intervals. However, if the claw portion 51 is formed over the entire peripheral surface of the partition member 5, the claw portion 51 can perform a sealing function between the inner cylinder member 4 and the partition member 5, and thus is more desirable. Become.

The claw portion 51 is fitted in a groove portion 41 provided on the inner peripheral surface of the inner cylinder member 4 along the circumferential direction, and the inner cylinder member 4 is
It is fixed inside. That is, on the inner peripheral surface of the inner tubular member 4,
A groove portion 41 having a size and shape for receiving the claw portion 51 is formed along the circumferential direction of the peripheral surface. Especially this groove 41
As shown in FIG. 1, when the partition member 5 is formed to have a depth that also receives the peripheral edge of the partition member 5, the peripheral edge of the partition member 5 and the claw portion are provided in the groove.
It is possible to fix the partition member 5 in the inner cylindrical member 4 by inserting the fitting member 51 and the movement of the partition member 5.

Then, a part or all of the tip and outer peripheral surface of the claw portion 51 is brought into close contact with the side surface or the bottom surface of the groove portion 41 of the partition wall member, whereby the partition member and the partition member 5 can be sealed. . At that time, it is desirable that the claw portion 51 and the groove portion 41 are in close contact with each other over a wider area.
The shape of the bottom surface of 41, that is, the shape of the bottom surface in the depth direction of the groove 41, is the shape that abuts the outer peripheral surface of the claw portion 51 received in the groove, specifically, as shown in FIG. It is desirable that the groove 41 be inclined so that the groove 41 becomes deeper toward the bottom.

In the ignition means accommodating chamber 6, an ignition means including an igniter is arranged. In the present embodiment, this ignition means includes two igniters 8a and 8b, a resin 15 member and a collar member 13 that hold the igniters, and any one of the igniters (hereinafter, the first igniter 8a ) Is arranged to face the transfer charge 17 and. The two igniters are installed in parallel in the collar member 13, integrated with the resin 15, and housed inside the skirt portion 42 of the inner cylinder member. The resin 15 that integrates the igniter is the first igniter.
A cylindrical container 14 surrounding a side surface of an igniter (hereinafter, second igniter 8b) different from 8a is integrally formed. The cylindrical container 14 that surrounds the second igniter 8b has a length that exceeds at least the upper surface of the second igniter 8b, and contacts the lower surface of the partition member 5, that is, the surface on the ignition means accommodating chamber 6 side. Form. This is because, as will be described below, in the gas generator shown in this embodiment, the sealing between the cylindrical container 14 and the partition member 5 is easily performed.

The lower surface of the partition member 5, that is, the ignition means accommodating chamber 6
On the side, a recess 52 that is recessed in the thickness direction of the partition member 5 and a communication hole 53 that also penetrates in the thickness direction are formed side by side. The communication hole 53 is formed at a position facing the second igniter 8b, and an annular groove 54 is formed so as to surround the communication hole 53. The annular groove 54 is formed so as to face the tubular container 14 surrounding the second igniter 8b, and an O-ring 55 is arranged in the annular groove 54. The O-ring 55 in the annular groove 54 provides a more reliable seal between the tubular container 14 and the partition member 5 in a state where the ignition means is arranged in the ignition means accommodating chamber 6. Therefore, the space inside the cylindrical container 14 accommodating the second igniter 8b can be communicated with the second combustion chamber 7b through the communication hole 53, and at the same time, the internal space of the other ignition means accommodating chamber 6 (that is, It is defined from the space where the first igniter 8a exists).

The recess 52 formed in the partition member 5 is formed to accommodate a part of the ignition means, in this embodiment, the transfer charge 17. That is, the transfer charge 17 is stored in the storage container 16 formed of an aluminum sheet and then in the recess 52, and the lower surface thereof is the first igniter 8a.
Abutted against and supported by. Particularly in the present embodiment, the space between the first igniter 8a and the partition member 5 is formed to be relatively narrow, but the recess 52 is formed to be sufficiently wide in the radial direction of the housing. Therefore, it is possible to secure a volume for accommodating the transfer charge 17 necessary for the operation of the gas generator. Then, by storing the transfer charge 17 in a space that is wide in the radial direction of the housing and short in the axial direction in this manner, the flame of the first igniter 8a can be spread over the entire transfer charge 17, which is a desirable mode. Becomes

In the present embodiment, a flame transfer hole for ejecting the flame generated by the operation of the first igniter 8a to the first combustion chamber 7a is formed on the peripheral surface of the inner cylindrical member 4 which is the partition member. 12, a gas flow hole that allows the second combustion chamber 7b and the first combustion chamber 7a to communicate with each other.
11 are formed along the circumferential direction.

The flame transfer hole 12 ejects the flame of the transfer charge 17 ignited by the operation of the first igniter 8a into the first combustion chamber 7a, and releases the gas generant contained in the first combustion chamber 7a. It ignites and burns. Therefore, the flame transfer hole 12 is formed so that the space in which the first igniter 8a or the transfer charge 17 is stored and the first combustion chamber 7a can communicate with each other.

In the present embodiment, as described above, since the upper surface of the partition member 5 which is present on the second combustion chamber 7b side is formed flat, there is no protrusion in the second combustion chamber 7b. Does not exist, and as a result, the axial length can be shortened as much as possible while ensuring the required space volume. As a result, the partition member 5 can be arranged further upward (that is, on the diffuser shell 1 side), and the axial length of the ignition device accommodating chamber can be increased. As a result, the distance (Lc) from the axial center of the inner cylinder member 4 of the flame transfer hole 12 formed in the inner cylinder member 4 on the ignition means accommodating chamber side is the average axial length of the partition member ( It can be formed in a range of ¼ or less of Ld) (that is, Lc ≦ Ld / 4). Further, regarding the arrangement position of the partition member 5 in the inner tubular member 4 which is a partition member, the distance from the axial center of the inner tubular member 4 can be 1/4 or less of the average axial length Ld of the inner tubular member 4. .

Since the first combustion chamber is formed on the outer side of the inner cylinder member 4, the flame transfer hole 12 is connected to Lc ≤ Ld /
If it is formed in the range of 4, the flame transfer hole 12 can be formed closer to the center in the axial direction of the first combustion chamber 7a. That is, the flame transfer hole 12 is a distance (Le) from the center of the average axial length of the first combustion chamber with respect to the inner surface of the bottom of the closure shell 1 (Le), the average axial length of the first combustion chamber ( Lf) 1
It can be formed in a range of / 4 or less.

Therefore, according to the present gas generator, the first gas generating agent 9a contained in the first combustion chamber 7a is effectively ignited and combusted from approximately the center in the axial direction, and as a result, the desired gas generation is achieved. The operating performance of the vessel can be obtained.

The gas flow hole 11 is for discharging the gas generated by the combustion of the second gas generating agent 9b into the first combustion chamber 7a, and the gas ejected into the first combustion chamber 7a is The coolant / filter 18 and further the gas outlet 10 are reached through the first combustion chamber 7a. This gas flow hole 11 is for the purpose of preventing the invasion of flame from the first combustion chamber 7a,
It can be closed with a seal tape or another sealing member, and the fire transfer hole 12 can be closed with a seal tape or another sealing member for the purpose of preventing moisture.

Further, the first gas generating agent 9a in the first combustion chamber 7a
Is supported by an annular underplate 20 which is arranged on the diffuser shell side and is fitted onto the inner cylinder member 4, and the second gas generating agent 9b in the second combustion chamber 7b is circular with an elastic portion. Is supported by the elastic supporting member 19 of FIG. This elastic support member 19 is a flat plate circular support surface 22 in contact with the second gas generating agent 9b, and a disc spring integrated with the support surface 22 and serving as a cushion between the inner surface of the diffuser shell.
23, and is arranged in the second combustion chamber 7b so as to spread in the radial direction.

In the operation of the gas generator shown in this figure, when the first igniter 8a receives an operation signal and starts its operation, the transfer charge 17 arranged immediately above is ignited and burned,
The flame is ejected from the flame transfer hole 12 into the first combustion chamber 7a. As a result, the first gas generating agent 9a in the first combustion chamber 7a is ignited and burned to generate working gas for inflating the airbag. The working gas is purified and cooled while passing through the coolant / filter 18 arranged on the outer side in the radial direction of the first combustion chamber 7a, and is discharged from the gas discharge port 10 to the outside of the housing 3. On the other hand, when the second igniter 8b receives the actuation signal at the same time as the first igniter 8a or slightly lags behind the first igniter 8a and starts the actuation, a flame or the like generated from the actuated igniter, The second gas generating agent 9b is jetted into the second combustion chamber 7b through the communication hole 53 to ignite and burn the second gas generating agent 9b. The working gas generated by the combustion of the second gas generating agent 9b flows into the first combustion chamber 7a through the gas flow hole 11 and is discharged similarly to the working gas generated in the first combustion chamber 7a. It is discharged from the outlet 10 to the outside of the housing 3.

According to the gas generator configured as described above, the inside of the housing 3 can be divided into three chambers with a smaller number of parts. Specifically, the first combustion chamber 7a, the second combustion chamber 7b, and the ignition means accommodating chamber 6 can be partitioned by only the inner cylinder member 4 and the partition member 5. Further, the space for accommodating the first igniter 8a and the space for accommodating the second igniter 8b in the ignition means accommodating chamber 6 may be partitioned by the resin 15 member that integrates the igniters and the O-ring 55. it can.

As a result, in this gas generator, the number of parts can be reduced, the assembling process can be simplified, and the manufacturing cost can be greatly reduced.

FIG. 3 shows an embodiment of the airbag apparatus of the present invention which is constructed by including the gas generator shown in FIG. 1 or 3.

This airbag device is equipped with a gas generator 200
The shock sensor 201, the control unit 202, the module case 203, and the airbag 204. As the gas generator 200, the gas generator described with reference to FIG. 1 is used, and its operation performance is adjusted so as not to give an impact to an occupant as much as possible in the initial stage of gas generator operation. ing.

The impact sensor 201 can be composed of, for example, a semiconductor type acceleration sensor. In this semiconductor type acceleration sensor, four semiconductor strain gauges are formed on the beam of a silicon substrate that is made to bend when acceleration is applied,
These semiconductor strain gauges are bridge-connected.
When acceleration is applied, the beam bends, causing distortion on the surface. This strain changes the resistance of the semiconductor strain gauge, 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 the signal from the semiconductor acceleration sensor is input to the ignition determination circuit. The control unit 202 starts calculation when the shock signal from the sensor 201 exceeds a certain value, and outputs an operation signal to the igniters 8a and 8b of the gas generator 200 when the calculated result exceeds the certain value. .

The module case 203 is formed of polyurethane, for example, and includes a module cover 205. The air bag 204 and the gas generator 200 are housed in the module case 203 to form a pad module. This pad module is usually attached to the steering wheel 207 when it is attached to the driver's seat side of the automobile.

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 flange portion of the gas generator in a folded state. Has been done.

When the semiconductor type acceleration sensor 201 detects a shock at the time of collision of a car, 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 8a and 8b of the gas generator 200. This allows the igniter 8a,
8b operates to ignite the gas generating agent, and the gas generating agent burns to generate gas. This gas blows out into the airbag 204, whereby the airbag ruptures the module cover 205 and swells, forming a cushion between the steering wheel 207 and the occupant for absorbing impact.

[0057]

According to the gas generator of the present invention, by adjusting the shape and location of the partition member that divides the inside of the partition member into two chambers that are axially adjacent to each other, the inside of the partition member is adjusted. It is possible to make the axial length of the ignition device accommodating chamber as long as possible while optimizing the space volume between the partitioned second combustion chamber and the ignition device accommodating chamber.

As a result, a flame transfer hole for releasing the flame or gas generated in the ignition means accommodating chamber to the first combustion chamber defined on the outer side in the radial direction of the partition wall member is provided near the axial center of the partition wall member. In addition, it can be formed near the axial center of the first combustion chamber.

As a result, the first gas generating agent can start combustion near the axial center of the first combustion chamber,
It is possible to effectively ignite and burn the first gas generating agent.

According to the gas generator of the basic invention,
By adopting a simple structure with a reduced number of parts, a gas generator for an air bag is realized which is easy to manufacture and has a reduced manufacturing cost. Moreover, in the gas generator, the overall size of the container can be suppressed, and further, operational safety and reliability can be ensured.

[Brief description of drawings]

FIG. 1 is a vertical sectional view showing an embodiment of a gas generator of the present invention.

FIG. 2 is an enlarged perspective view of an essential part showing the partition member of FIG.

FIG. 3 is a configuration diagram of an airbag device of the present invention.

[Explanation of symbols]

3 housing 4 Inner tube member 5 partition members 6 Ignition means housing chamber 7a, b First and second combustion chambers 8a, b 1st, 2nd igniter 9a, b First and second gas generating agents 10 Gas outlet 11 Gas distribution hole 12 Fire hole 13 Color member 14 Cylindrical container 17 Transfer charge 51 Claw 52 Cavity 53 communication hole 54 annular groove 55 O-ring 200 gas generator 201 Impact sensor 202 control unit 204 airbag

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Toshiro Iwakiri             500 Kamimabe, Yobu Ward, Himeji City, Hyogo Prefecture F term (reference) 3D054 AA02 AA13 DD17 DD28 DD32                       EE14 EE25                 4G068 DA08 DB14 DB15 DC01

Claims (10)

[Claims] 1. A partition member having an annular peripheral wall is arranged in a housing having a gas discharge port, and a first combustion chamber for containing a first gas generating agent is provided outside the partition member in a radial direction. A disk-shaped partition member is arranged inside the partition member, and the inside of the partition member is partitioned into a second combustion chamber that stores the second gas generating agent and an ignition unit storage chamber that stores the ignition unit. In the airbag gas generator, the second combustion chamber and the ignition means accommodating chamber are arranged adjacent to each other in the axial direction of the partition member via the partition member, and the annular peripheral wall has The ignition means accommodating chamber and the first combustion chamber are communicated with each other, and the partition member is arranged in the partition member such that the distance from the axial center of the partition member is the axial average of the partition member. Length 1
A gas generator for an air bag, which is formed in a range of / 4 or less. 2. The air according to claim 1, wherein the fire transfer holes are formed in a range in which a distance from the axial center of the partition member is ¼ or less of an average axial length of the partition member. Gas generator for bags. 3. A partition member having an annular peripheral wall is arranged in a housing having a gas discharge port, and a first combustion chamber for containing a first gas generating agent is provided on an outer side in a radial direction of the partition member. A disk-shaped partition member is arranged inside the partition member, and the inside of the partition member is partitioned into a second combustion chamber that stores the second gas generating agent and an ignition unit storage chamber that stores the ignition unit. In the airbag gas generator, the second combustion chamber and the ignition means accommodating chamber are arranged adjacent to each other in the axial direction of the partition member via the partition member, and the annular peripheral wall has , A igniting hole that allows the igniting means accommodating chamber and the first combustion chamber to communicate with each other, and the diverging hole has a distance from the center of the partition member in the axial direction of 1 Gas for air bag characterized by being formed in a range of / 4 or less Raw device. 4. The upper surface of the partition member, which is located on the second combustion chamber side, is formed flat, and the second combustion chamber is formed in a cylindrical space. A gas generator for an airbag as described. 5. The ignition means includes at least one or more electric ignition type igniters and a transfer charge arranged to face the axial direction of the igniters, 5. The lower surface existing on the ignition means accommodating chamber side is provided with a recessed portion that is recessed in the thickness direction of the partition member and that stores a part or all of the transfer charge. A gas generator for an airbag as described. 6. The gas generator for an air bag according to claim 5, wherein the flame transfer hole is formed at a height facing the transfer charge. 7. The flame transfer hole is formed from a center of an average length in an axial direction of the first combustion chamber with reference to an inner surface of a bottom of a closure shell,
The gas generator for an air bag according to any one of claims 1 to 6, which is formed within a range of ¼ or less of an average length in the axial direction of the first combustion chamber. 8. The ignition means comprises two electric ignition type igniters, and the respective igniters are arranged in different spaces defined in an ignition means accommodating chamber, and any one of the ignition means is arranged. The existing space can be communicated with the second combustion chamber through a communication hole formed in the thickness direction of the partition member.
A gas generator for an air bag according to any one of items 1 to 7. 9. A peripheral surface of the partition member is provided with a claw portion that spreads in a hakama shape in a thickness direction thereof, and the claw portion is fitted into a groove portion provided on an inner peripheral surface of the annular peripheral wall and extending in the circumferential direction. The gas generator for an air bag according to any one of claims 1 to 8, which is provided. 10. A gas generator for an air bag, an impact sensor that senses an impact and activates the gas generator, an airbag that introduces and inflate gas generated by the gas generator, and the airbag. Including a module case that accommodates
An airbag device, wherein the airbag gas generator is the airbag gas generator according to any one of claims 1 to 9.