JP2003312435A - Gas generator for air bag - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a gas generator for an air bag for individually adjusting a combustion condition of a gas generating agent of respective combustion chambers with respective combustion chambers by arranged two combustion chambers in a housing, easy in manufacture, and satisfying a request for miniaturization. <P>SOLUTION: In this gas generator for the air bag, an inner cylinder member having a cylindrical peripheral wall is arranged in the housing having a gas exhaust port, the two combustion chambers partitioned by the inner cylinder member are arranged, the respective combustion chambers are respectively filled with the gas generating agent for generating operating gas by combustion, and the operating gas generated in the respective combustion chambers reaches the gas exhaust port via mutually different passages. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

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 as an airbag for protecting an occupant from an impact, and an airbag device using the same.

2. Description of the Related Art An air bag device is mounted on an automobile or the like for the purpose of protecting an occupant from the impact at the time of a collision, and this is rapidly activated by the operation of an air bag gas generator. The gas is generated, and thereby the airbag (bag body) is inflated. In a general gas generator, when the ignition means is activated by impact, this ignites and burns the gas generating agent to generate high temperature and high pressure gas, and the generated gas is discharged from the gas outlet into the airbag (bag body). Gushes into.

The combustion chamber in which the gas generating agent is housed is designed variously depending on the shape of the housing and the arrangement of the necessary constituent members, and the shape and composition of the gas generating agent filled therein are also various. Things are being used.

In adjusting the operating performance of the gas generator, the degree of combustion of the gas generating agent can be an important design element. 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.

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

The amount of the gas generating agent used in the gas generator is also an important design factor in adjusting the operating performance of the gas generator. Usually, the gas generating agent is filled in the combustion chamber provided in the housing, so that the volume of the combustion chamber needs to be adjusted in order to adjust the usage amount of the gas generating agent.

Further, there is a gas generator in which two combustion chambers are provided in the housing and a gas generating agent is filled in each combustion chamber. Such a gas generator is formed so that the ignition timing of the gas generating agent in each combustion chamber can be adjusted in order to obtain optimum operating performance. In such a gas generator, it is desirable that the combustion condition of the gas generating agent housed in each combustion chamber can be independently adjusted for each combustion chamber, and the demand for easy manufacture and miniaturization is satisfied. There is a need to. In addition, the gas generator needs to operate reliably for the life of the vehicle from the viewpoint of passenger protection. Therefore, as one of the means for reliably operating the gas outlet, the gas outlet is closed from the inside with one or more sealing tapes for the purpose of preventing the invasion of outside air (humidity). When assembling the gas generator, usually after applying the sealing tape from the inside of the gas outlet of the housing,
Although a procedure of assembling other members is adopted, there is a risk of breaking the seal tape when assembling other members, particularly members arranged near the gas discharge port in this way. Since the seal tape is attached from the inside of the gas discharge port, if the seal tape is torn, it will be necessary to start over from the first step and the workability will be reduced. Further, the sticking work of the seal tape itself is complicated, and especially when sticking two or more sheets in order to enhance the adhesion strength, it takes too much work time and the seal tape is expensive. It is also a factor that increases costs. The present invention is a gas generator in which two combustion chambers are provided in a housing, and the combustion condition of the gas generating agent in each combustion chamber can be independently adjusted for each combustion chamber, improving assembly workability. An object of the present invention is to provide an airbag gas generator that can reduce manufacturing costs and an airbag device using the same.

The invention according to claim 1 is
As a means for solving the above-mentioned problems, two combustion chambers, which are partitioned from each other by inner cylindrical members, are provided in a housing composed of a diffuser shell having a plurality of gas discharge ports closed by a sealing tape and a closure shell. A gas generator for an air bag in which each combustion chamber is filled with a gas generating agent that combusts to generate a working gas, and the working gas generated in each combustion chamber reaches the gas exhaust port through mutually different flow paths. The diffuser shell has a step so that the inner diameter becomes large and small, and at least a part of the gas discharge port is provided in the large diameter portion of the diffuser shell, and the space between the diffuser shell and the inner cylindrical member is annular. The flow path of the working gas generated in the two combustion chambers is separated by the retainer, and the annular retainer is formed by the inner cylinder member and the diffuser. To provide a gas generator for an air bag that is in contact with the respective inner wall surfaces of the Le small diameter portion. According to the above invention, when the retainer is inserted into the diffuser shell when assembling the gas generator for the airbag, the diameter of the retainer is smaller than the diameter of the large diameter portion of the diffuser shell. It does not touch the sealing tape that closes the gas outlet provided in the large diameter portion. Therefore, it is possible to prevent the seal tape from being damaged during assembly, and it is particularly suitable when two or more seal tapes are laminated to close the gas discharge port. Also,
A part of the gas outlet can be provided in the small diameter portion of the diffuser shell, and at this time, it is desirable that the retainer is brought into contact with a position where it does not come into contact with the gas outlet. The invention according to claim 2 is, as a means for solving the above-mentioned problems, partitioned by an inner tubular member from each other in a housing composed of a diffuser shell having a plurality of gas discharge ports closed by one sealing tape and a closure shell. Two combustion chambers are provided, each combustion chamber is filled with a gas generating agent that combusts to generate a working gas, and the working gas generated in each combustion chamber passes through different flow paths from each other. A gas generator for an air bag that reaches the discharge port, wherein the space between the diffuser shell and the inner cylinder member is partitioned by annular retainers that are arranged in contact with the inner wall surface of the diffuser shell and the inner cylinder member, respectively. The flow paths of the working gas generated in the two combustion chambers are separated, and the annular retainer is located inside the housing in the radial direction of the housing in contact with the inner wall surface of the diffuser shell. A gas generator for an air bag, which has a bulge portion, the bulge portion forming an annular groove around a retainer, an O-ring being arranged in the annular groove, and pressing a sealing tape. I will provide a. By arranging an annular retainer having such an annular groove and pressing the sealing tape with an O-ring arranged in the annular groove, it is possible to enhance the adhesion strength of the sealing tape to the inner wall surface of the diffuser shell without damaging the sealing tape. You can Further, since the sealing tape can be made into one sheet by increasing the adhesion strength in this way, the manufacturing process can be simplified and the manufacturing cost can be reduced. The annular retainer used in the above invention has at least an annular locking portion, an annular partition wall portion and a tubular portion, and the locking portion is abutted against the inner tubular member, and mainly the annular partition wall portion serves as a diffuser. It is preferable that the space between the shell and the inner tubular member is separated, and the outer end surface of the tubular portion is in contact with the inner wall surface of the diffuser shell.

The inner cylinder member has a cylindrical peripheral wall, which defines a combustion chamber. It is desirable that the ignition means normally provided for igniting the gas generating agent is housed inside the inner cylinder member. One inner cylinder member is arranged in the housing, and preferably a combustion chamber is defined inside and outside the inner cylinder member. When arranging the ignition means inside the inner cylinder member, it is desirable to accommodate all the ignition means included in the gas generator inside the inner cylinder member. In this case, the same inner cylinder member that defines the combustion chamber and the inner cylinder member that houses the ignition means (that is, a single inner cylinder member) are used.

The working gas flow path is a path (or a flow direction) of the working gas in the housing, and it means that the working gas flow paths generated in the respective combustion chambers are different from each other. This means that the working gas flow path generated in the chamber and the working gas flow path generated in the other combustion chambers are different from each other at least in any part. Therefore, even when the working gas generated in one combustion chamber passes through the coolant means existing outside in the radial direction as it is, the working gas generated in the other combustion chamber flows into the coolant means from the one combustion chamber. If the route is not followed, the flow paths of the respective working gases will be different from each other.

As described above, by making the flow paths of the working gas generated in each combustion chamber different from each other, it is possible to easily adjust the generation degree of the working gas in each combustion chamber.

Further, by dividing the two combustion chambers by the inner tubular member having the tubular peripheral wall and accommodating the ignition means inside the inner tubular member, the gas generator can be miniaturized. .

That is, according to the present invention, a gas generator for an air bag is provided which is capable of independently adjusting the combustion condition of the gas generating agent in each combustion chamber while realizing the downsizing of the gas generator. It can be a bowl.

Further, according to the present invention, the working gas generated in one of the two combustion chambers provided in the housing reaches the gas exhaust port without flowing into the other combustion chamber. A gas generator is also provided. As a result, the working gas generated in one of the combustion chambers does not participate in the combustion of the gas generating agent in the other combustion chamber, and the combustion states of the gas generating agents in the respective combustion chambers can be adjusted independently of each other. it can.

By partitioning the inside of the housing so that the working gas generated in any one of the combustion chambers passes through the flow space partitioned from the other combustion chamber, the working gas generated in any of the combustion chambers becomes Will not flow into the combustion chamber. This distribution space can be defined, for example, by a retainer that defines the end of the other combustion chamber.

In the above-mentioned gas generator, the working gas generated in each combustion chamber can pass through different coolant means to reach the gas discharge port, and can be formed so as to reach different gas discharge ports. You can also

When the gas exhaust port and the coolant means are made different for each working gas generated in each combustion chamber, it goes without saying that these gas exhaust port and the coolant means must be provided corresponding to each combustion chamber. That is, a dedicated gas outlet and / or closure shell is provided for the working gas produced in one combustion chamber.

When the gas outlet and the coolant means are different for each working gas generated in each combustion chamber, a working gas distribution space is formed in the housing, and the working gas generated in any one of the combustion chambers is distributed through this distribution space. It can also be formed so as to pass through a space. At this time, two circulation spaces may be formed in the housing so that the working gas generated in each combustion chamber passes through the different circulation spaces.

The distribution space communicating with any one of the combustion chambers is arranged, for example, in another combustion chamber with a retainer that defines the end of the other combustion chamber, and on the opposite side of the retainer from the combustion chamber. It is also possible to use a compartmented space. In this case, the retainer needs to include at least a partition for defining the end of the other combustion chamber and a structure for supporting or fixing in the housing. As such a retainer, for example, an outward or inward flange-shaped partition wall portion can be integrally formed on a tubular portion formed in a substantially cylindrical shape. In the retainer thus formed, the tubular portion can also be supported and fixed in the housing by externally fitting or internally fitting the inner wall surface of the housing or a member arranged in the housing.

The distribution space can be secured not only by the retainer, but also by a member (for example, an inner cylinder member) having a cylindrical peripheral wall that further divides the combustion chambers from each other, and has a housing structure. It can also be secured by changing it.

In the gas generator formed as described above,
The working gases generated in the two combustion chambers reach the coolant means and the gas outlet through different flow paths. That is, the working gas generated in one of the combustion chambers does not affect the combustion of the gas generating agent contained in the other combustion chamber. Therefore, even if both combustion chambers are connected through a slight gap, the working gas generated in one of the combustion chambers must affect the combustion of the gas generant contained in the other combustion chamber. For example, the degree of generation of the working gas in each combustion chamber can be adjusted independently of each other.

Therefore, in the gas generator of the present invention, any one of
Even if the gas generating agent in the other combustion chamber burns, the gas generating agents in the other combustion chambers burn without being significantly affected by the combustion pressure, the heat of combustion, etc. generated in the one combustion chamber. As a result, the degree of combustion of the gas generant contained in each combustion chamber can be adjusted for each combustion chamber, that is, the operating performance of the gas generator can be adjusted easily and reliably.

Further, by making the paths from the respective combustion chambers to the coolant means different from each other, there is no occurrence of fire between the combustion chambers. As a result, even when the combustion chamber and the distribution space are closed with a sealing tape, a sealing tape having a low burst strength or a low melting point, for example, an aluminum sealing tape having a metal layer of 80 μm is used. can do.

The above-mentioned gas generator for an air bag of the present invention comprises:
For example, the following gas generator can be used. That is, an inner cylinder member that defines an inner space in the housing is formed in a cylindrical housing that is formed by a diffuser shell in the shape of a cylindrical body having a gas discharge port and a closure shell that forms an inner space together with the diffuser shell. Are arranged, and the outer side in the radial direction is defined as the first combustion chamber. The inner side of the inner cylinder member is partitioned by a partition wall so as to be adjacent in the axial direction, and the diffuser shell side is the second combustion chamber,
The closure shell side is used as the ignition device accommodating chamber. Each combustion chamber is filled with a gas generating agent, and the ignition means accommodating chamber is provided with an ignition means for starting the operation of the gas generator. On the outer side in the radial direction of the first combustion chamber, an annular coolant means formed by using a laminated wire mesh or the like is arranged in order to cool or purify the working gas generated in each combustion chamber.

In this gas generator, the working gas flow space has, for example, a retainer arranged at the axial end of the first combustion chamber to close the axial end of the first combustion chamber. It can be formed between the retainer and the inner surface of the diffuser shell. At that time, a communication hole is formed in the peripheral wall of the inner tubular member, and the communication hole is formed so that the second combustion chamber communicates with the distribution space.

Since the gas generator of the present invention is provided with two combustion chambers, it is desirable that the gas generating agent in each combustion chamber can be burned at different timings. Therefore, in the gas generator for an air bag of the present invention, it is preferable to use an ignition means such as using two igniters whose operation timings can be arbitrarily changed.

Further, the gas generator includes an impact sensor that senses an impact and operates the gas generator, an airbag that introduces and inflate gas generated by the gas generator, and a module case that accommodates the airbag. And an airbag device including

The gas generator is housed in a module case together with an air bag (bag) that injects the generated gas and expands, and is provided as a pad module.

In this airbag device, the gas generator operates due to the impact sensor sensing the impact, and the working gas is discharged from the gas discharge port of the housing. The working gas flows into the airbag, whereby the airbag ruptures the module cover and swells to form a shock absorbing cushion between the hard structure in the vehicle and the occupant.

BEST MODE FOR CARRYING OUT THE INVENTION A gas generator for an air bag of the present invention will be described below with reference to the drawings showing preferred embodiments. FIG. 1 is a longitudinal sectional view showing an embodiment of an airbag gas generator according to the present invention. In the gas generator shown in this embodiment, two combustion chambers are provided in a housing, and an ignition means including two igniters corresponding to the respective combustion chambers is arranged. More specifically, the diffuser shell 1 having the gas discharge ports 26a and 26b
And a diffuser shell 1 and a closure shell 2 that forms an internal housing space are joined to each other, a substantially cylindrical inner cylindrical member 4 is arranged in a housing 3, and the outer side thereof is a first combustion chamber 5a. The gas outlets 26a and 26b are closed from the inside by sealing tapes 27a and 27b made of aluminum, respectively. Gas outlet of diffuser shell 1 26
A step portion 1a is provided between a and the gas discharge port 26b. In the diffuser shell 1, the gas discharge port 26a side is a large diameter portion in the radial direction of the housing and the gas discharge port 26b side is a small diameter portion in the radial direction of the housing with the step portion 1a as a boundary. Further, the inside of the inner tubular member 4 is divided into two chambers by a partition wall 7, and the diffuser shell 1 side thereof is the second combustion chamber 5b and the closure shell 2 side thereof is the ignition means accommodating chamber 12. The partition 7 is locked to the stepped portion 6 on the inner surface of the inner tubular member 4.

Two combustion chambers defined within the housing 3
5a, 5b is filled with a gas generating agent 9a, 9b for each combustion chamber, the first gas generating agent 9a in the first combustion chamber 5a, the second gas generating agent in the second combustion chamber 5b. 9b are filled respectively.
This gas generating agent is ignited and burned by the operation of the ignition means to generate a working gas for inflating the airbag. The first and second gas generating agents 9a, 9b, for each combustion chamber,
The shape, composition, composition ratio, amount and the like can be varied. Particularly, in the present embodiment, the first gas generating agent 9a is a gas generating agent formed by containing a fuel and an oxidant, and a guanidine derivative or a mixture thereof is used as the fuel, and the gas generating agent is used as the oxidant. A gas generant in which basic copper nitrate is used is used. The second gas generating agent 9b is the same as the first gas generating agent 9a.

Diffuser shell in the first combustion chamber 5a
A retainer 50 having an annular partition wall portion 52 is arranged at the axial end on the first side, and the retainer 50 has the partition wall portion.
At 52, the axial length of the first combustion chamber 5a is determined, and a distribution space 55 for guiding the working gas generated by the combustion of the second gas generating agent to the coolant means is defined. The retainer 50 is configured to include a tubular portion 51 that is arranged to face the inner tubular member at a predetermined interval, and an annular partition wall portion 52 that is bent outward from the tubular portion 51 in a flange shape. Further, an inward flange-shaped locking portion 56 is formed on the side of the tubular portion 51 opposite to the side where the partition wall portion 52 is formed. On the outer periphery of the inner tubular member 4, a stepped notch portion 53 is formed by cutting the closure shell 2 side into a stepped shape to reduce the outer diameter,
The retainer 50 is arranged and fixed by locking its locking portion 56 to the stepped portion 53. In the retainer 50 shown in FIG. 1, when the first gas generating agent burns during operation of the gas generator, the combustion pressure pushes the retainer 50 in the supporting direction by the stepped portion 53, so that the fixed state and the close contact state are more reliable. It will be

Further, in the retainer 50 shown in the present embodiment, since the tubular portion 51 is arranged so as not to close the communication hole 10 and face each other, the second portion discharged from the communication hole 10 The working gas resulting from the combustion of the gas generating agent 9b once collides with the tubular portion 51 of the retainer. Therefore, for example, when the second gas generating agent 9b produces combustion products of a fluid or a semi-fluid at the time of combustion, these combustion products collide with the tubular portion 51 and are removed from the working gas. To be done. As a result, when a gas generating agent that produces such a combustion product is used as the second gas generating agent 9b, the combustion product is removed by the tubular portion 51, so that the second coolant means described later is used. The amount of 22b and the thickness in the radial direction can be reduced.

The retainer 50 can adjust the internal shape, volume, etc. of the first combustion chamber 5a by adjusting the location of the retainer 50 and the position of the partition wall 52. Therefore, by adjusting the shape and location of the retainer 50, as shown in FIG. 1, the radial average distance (L) of the first combustion chamber 5a to the axial average length (L) of the first combustion chamber 5a (L). D)
Ratio (D / L) of 0.2 to 2.0, preferably 0.
It can be adjusted to 4 to 1.0. In the present embodiment, the two end surfaces of the first combustion chamber 5a on the closure shell side are
The combustion chamber defined by the inner surface of the closure shell 2 and
The gas generating agent 9a in 5a is supported by the under plate 54. Further, the retainer 50 shown in the present embodiment is the first combustion chamber.
A flow space 55 is defined on the side opposite to 5a for allowing the working gas generated by the combustion of the second gas generating agent 9b to pass therethrough. Therefore, the distribution space 55 and the first combustion chamber are adjacent to each other in the axial direction of the housing via the retainer.
The distribution space may be formed so as to penetrate the first combustion chamber. The communication space 55 and the second combustion chamber 5b can communicate with each other through a communication hole 10 formed in the peripheral wall of the inner cylindrical member 4. That is, the communication hole 10 is closed by a seal tape 11 described later, the seal tape is ruptured by the combustion of the second gas generating agent, the communication space 55 and the second combustion chamber 5b will be communicated. .

In the ignition means accommodating chamber 12, two igniters 23a,
An ignition means is housed which includes 23b and transfer charge 16 filled in an aluminum cup. Two igniters 23a, 23b
Is fixed to the collar assembly 31, and the collar assembly 31 is fixed by caulking the lower end portion 4a of the inner tubular member 4. The first igniter 23a and the second igniter 23b are respectively housed in the space partitioned by the partition wall 7, and the transfer charge 16 is contained in the space where the first igniter 23a is housed. , Is disposed above the first igniter 23a.

On the other hand, the space in which the second igniter 23b is housed is formed so as to communicate with the second combustion chamber 5b, and the second combustion chamber 5b has a communication hole 10 formed in the inner cylindrical member 4. It is formed so that it can communicate with the distribution space 55 defined by the retainer 50.

The working gas produced by the combustion of the first gas generating agent 9a and the second gas generating agent 9b both passes through an annular coolant means 22 formed by laminating wire mesh, expanded metal, etc. It is formed so as to be discharged from the outlet 26, and in particular, in the present embodiment, each gas generating agent is
The working gases emanating from 9a, 9b are formed as passing through different coolant means 22a, 22b respectively.
Specifically, the first coolant means 22a is arranged on the outer side in the radial direction of the first combustion chamber 5a, and the second coolant means 22b is arranged on the outer side in the radial direction of the second combustion chamber 5b via the circulation space 55. , Both the coolant means 22a, 22b, the retainer 5
Separated by 0. In the gas generator shown in FIG. 1,
A first combustion chamber is formed adjacent to the inside of the first coolant means.

Therefore, in the gas generator shown in this embodiment, the transfer charge 16 is burned by the operation of the first igniter 23a, and the flame thereof passes through the first transfer hole 17a into the first combustion chamber 5a. Gush out. As a result, the first gas generating agent 9a ignites and burns to generate working gas, which is the first coolant means 22.
After passing through a, it reaches the gap 25 and is then discharged from the gas discharge port 26. On the other hand, when the second igniter 23b is activated, the flame thereof is ejected into the second combustion chamber 5b to ignite and burn the second gas generating agent 9b. The working gas generated by the combustion of the second gas generating agent 9b exits from the communication hole 10 to the distribution space 55, passes through this, and reaches the second coolant means 22b. Then, while passing through the second coolant means 22b, it is cooled and purified and the gap 25
Through the gas discharge port 26. In this way, by changing the flow path and coolant means for each working gas generated in each combustion chamber, it is possible to easily adjust the combustion condition of the gas generant in each combustion chamber, and as a result, the working output of the gas generator. It will be easier to adjust.

In the gas generator operating as described above, even if the first gas generating agent burns, the flame thereof does not jet toward the outlet (that is, the communicating hole) side of the second combustion chamber. Therefore, when selecting the seal tape that seals the second combustion chamber and the distribution space, it is not necessary to consider the influence of the combustion of the first gas generating agent. As a result, even an aluminum sealing tape using aluminum having a lower melting point than stainless steel can be used.

Further, in the gas generator shown in this figure, since the two coolant means 22a, 22b are separately arranged, each of them corresponds to the amount of working gas generated in each combustion chamber 5a, 5b. The cleaning / cooling capacity of the coolant means 22a, 22b can be adjusted. And the second gas generating agent 9b
The second coolant means 22 is used to cool the working gas generated by the combustion of
If it is shared by b, it is possible to secure a large inner diameter of the first coolant means 22a, and thereby it is possible to increase the radial distance (D) of the first combustion chamber 5a.

In FIG. 1, reference numeral 11 is a seal tape for closing the communication hole 10, and reference numeral 18 is a seal tape for closing the first flame transfer hole 17a. These seal tapes burst when flames or gases pass through the holes or mouths.

In the gas generator shown in FIG. 1, the working gas generated in each combustion chamber reaches the filter means through different flow passages, and the filter means is also arranged corresponding to each combustion chamber. .

In FIG. 1, the retainer 50 is the first combustion chamber 5a.
The axial end portion of is determined and the average axial length of the first combustion chamber 5a is adjusted. Furthermore, the retainer 50 has gas outlets 26a and 2a provided on the diffuser shell 1 at the outer wall end surface thereof.
It is in contact with the inner wall surface of the small diameter portion between 6b and, and separates the flow paths of the working gas generated in the first combustion chamber 5a and the working gas generated in the second combustion chamber 5b. Therefore, the working gas generated in the first combustion chamber 5a is discharged from the gas outlet 26a after breaking the seal tape 27a, and the working gas generated in the second combustion chamber 5b breaks the seal tape 27b. The gas is discharged from the gas discharge port 26b later. In this way, the gas outlet 26a is provided in the large diameter portion of the diffuser shell 1, the gas outlet 26b is provided in the small diameter portion, and the outer wall end surface of the retainer 50 is provided with the gas outlets 26a and 26a.
Since the retainer 50 is inserted into the diffuser shell 1 when assembling the airbag gas generator, the retainer 50 has a diameter of the diffuser shell 1 that is abutted against the inner wall surface of the small diameter portion between the retainer 50 and the 6b. Since it is smaller than the diameter of the large diameter part, the outer wall end surface of the retainer 50 is located at the gas outlet 26a.
Does not touch the sealing tape 27a that closes. Furthermore, since the outer wall end surface of the retainer 50 is brought into contact with the inner wall surface of the small diameter portion between the gas discharge ports 26a and 26b, the gas discharge port 26
The sealing tape 27b that closes b is also not touched. Therefore, the seal tapes 27a and 27b are prevented from being damaged during assembly.

FIG. 2 shows a gas generator characterized in the engagement portion between the inner wall surface of the diffuser shell 1 and the retainer. That is, in the gas generator shown in this figure, on the outer wall surface of the tubular portion (or inner tubular portion) of the retainer 50,
A bulging part is formed by bulging a part thereof inward in the radial direction, and the bulging part is formed around the retainer 50 in the annular groove 6.
3 is formed. An O-ring 64 is arranged in the annular groove 63. As a result, the inner wall surface of the diffuser shell 1 and the retainer 50 (in particular, the annular groove 63)
Is sealed by an O-ring 64, and even if the first gas generating agent 9a burns, the working gas does not enter the flow space (or flow path) 55 side. Moreover, when the first gas generating agent 9a and the second gas generating agent 9b are simultaneously burned, the first gas generating agent 9a remains inside the first combustion chamber 5a.
Since the pressure is sufficiently increased by the combustion of a, the working gas generated by the combustion of the second gas generating agent 9b does not flow into the first combustion chamber 5a.

In particular, in the case of the engagement structure of the inner cylinder member and the retainer as shown in FIG. 2, since the retainer 50 is supported by the second coolant means 22b, the retainer 50 is prevented from moving in the axial direction of the housing. Further, since it is possible to eliminate cutting work on the outer peripheral surface of the inner cylindrical member (that is, the outer peripheral surface of the cylindrical peripheral wall), it is advantageous in manufacturing and cost. The annular retainer 50 having such an annular groove 63 is arranged, and by the O-ring 64 arranged in the annular groove 63,
By pressing the seal tape 27 between the gas discharge ports 26a and 26b, the adhesion strength of the seal tape 27 to the inner wall surface of the diffuser shell 1 can be increased without damaging the seal tape 27.

Of the members shown in FIG. 2, those having the same functions as those of the members of the gas generator shown in FIG. 1 are designated by the same reference numerals and the description thereof will be omitted. Also, the shape of the tubular portion on the radially inner side of the retainer 50 that abuts the inner tubular member 4 is
As shown in FIGS. 1 and 2, instead of the retainer 50 fitted inside the stepped portion 6 of the inner tubular member 4, the inner surface of the tubular member is formed on the wall surface of the inner tubular member 4 having no stepped portion 6. It may be in contact with (vertical direction).

An airbag system of the present invention using the above-mentioned airbag gas generator comprises an actuation signal output means comprising an impact sensor and a control unit, a module case accommodating the airbag gas generator and the airbag. It is equipped with. The airbag gas generator is connected to operation signal output means (impact sensor and control unit) on the first and second igniters 23a and 23b side. In the airbag system having such a configuration, by appropriately setting the operation signal output condition in the operation signal output means, the gas generation amount can be adjusted according to the degree of impact, and the inflation speed of the airbag can be adjusted. . The structure other than the gas generator in this airbag system can be easily understood from the one disclosed in Japanese Patent Laid-Open No. 11-334517, for example.

[0044]

The air bag gas generator of the present invention has a structure in which the overall size of the gas generator is suppressed, but the working gas generated in each combustion chamber can be guided to the coolant means through different flow paths. Therefore, the combustion condition of the gas generating agent housed in each combustion chamber can be adjusted independently of each other, whereby the operation output of the gas generator can be easily adjusted. As a result, the weight of each coolant means can be reduced. This becomes more noticeable by changing the coolant means and the gas discharge port for each combustion chamber.

In particular, in the gas generator in which the retaining space is secured by the retainer as shown in the above-mentioned embodiment, the seal tape attached to the gas discharge port of the diffuser shell is prevented from being damaged, and The degree of adhesion to the inner wall surface of the housing can be improved.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view showing a gas generator for an airbag according to an embodiment.

FIG. 2 is a vertical sectional view showing a gas generator for an airbag according to another embodiment.

[Explanation of symbols]

3 housing 4 Inner tube member 5a, 5b combustion chamber 7 partition 9a, 9b Gas generator 12 Ignition means housing chamber 16 Transfer charge 17a, 17b Fire hole 22a, 22b Coolant means 23a, 23b igniter 25 gap 26 Gas outlet 50 retainer 51 Cylindrical part 52 Partition surface 54 Under plate 55 distribution space

Claims (18)

[Claims] 1. A housing composed of a diffuser shell having a plurality of gas outlets closed by a sealing tape and a closure shell is provided with two combustion chambers partitioned from each other by an inner cylindrical member. A gas generator for an air bag in which a combustion chamber is filled with a gas generating agent that combusts to generate a working gas, and the working gas generated in each combustion chamber reaches the gas exhaust port through mutually different flow paths. , The diffuser shell has a step so that the inner diameter becomes large and small, and at least a part of the gas discharge port is provided in the large diameter part of the diffuser shell, and the space between the diffuser shell and the inner cylinder member is formed by an annular retainer. The flow path of the working gas generated in the two combustion chambers is divided, and the annular retainer is provided in the inner cylinder member and the small diameter portion of the diffuser shell. Gas generators for airbags that are in contact with each of the inner wall surfaces. 2. A combustion chamber, which comprises a diffuser shell having a gas discharge port closed with a sealing tape and a closure shell, is provided with two combustion chambers partitioned from each other by inner cylindrical members. Is a gas generator for an air bag that is filled with a gas generating agent that combusts to generate a working gas, and the working gas generated in each combustion chamber reaches the gas discharge port through mutually different flow passages. The space between the shell and the inner cylinder member is partitioned by an annular retainer that is arranged in contact with the inner wall surface of the diffuser shell and the inner cylinder member, and the flow paths of the working gas generated in the two combustion chambers are separated. The annular retainer has a bulge inward in the radial direction of the housing at the portion that contacts the inner wall surface of the diffuser shell, and the bulge is the circumference of the retainer. The forms an annular groove, wherein the O-ring is disposed in the annular groove, the gas generator for an air bag presses the sealing tape. 3. An annular retainer having at least an annular locking portion, an annular partition wall portion and a tubular portion,
The locking portion is brought into contact with the inner tubular member, the space between the diffuser shell and the inner tubular member is mainly separated by the annular partition wall portion, and the outer end surface of the tubular portion is brought into contact with the inner wall surface of the diffuser shell. Item 1. The gas generator for an airbag according to Item 1 or 2. 4. The method according to claim 1, further comprising ignition means for igniting the gas generating agent, the ignition means being housed inside the inner cylinder member. Gas generator for airbags. 5. The working gas generated in one of the combustion chambers passes through a flow space defined by another combustion chamber and does not pass through the other combustion chamber. The gas generator for an airbag according to claim 1. 6. The gas generator for an air bag according to claim 1, wherein the working gas generated in each combustion chamber passes through different coolant means and reaches the gas discharge port. 7. The gas generation for an air bag according to claim 1, wherein the working gas generated in each combustion chamber reaches different gas discharge ports provided corresponding to each combustion chamber. vessel. 8. Either one or both of the gas discharge port and the coolant means are provided independently of each other, corresponding to each combustion chamber defined in the housing.
The gas generator for an air bag according to any one of claims 1 to 5. 9. The two combustion chambers according to claim 1, wherein all or a part of one of the combustion chambers is surrounded by another combustion chamber and is partitioned in the housing. Gas generator for airbags. 10. The coolant means is formed in a tubular shape, and either or both combustion chambers of the two combustion chambers are formed adjacent to the inside of the coolant means. 10. A gas generator for an air bag according to any one of claims 9 to 10. 11. The working gas generated in one of the two combustion chambers reaches a gas outlet through a flow space formed so as to communicate with the combustion chamber. The gas generator for an air bag according to any one of 1 to 10. 12. The working gas produced in one of the two combustion chambers reaches a gas outlet through a flow space formed so as to communicate with the combustion chamber, The gas generator for an air bag according to any one of claims 1 to 11, wherein the distribution space penetrates another combustion chamber or is adjacent to and is partitioned in the housing. 13. The flow space communicating with any one of the two combustion chambers is defined in the housing by a retainer that defines an end of the other combustion chamber. 12. The gas generator for an air bag according to 12. 14. A seal tape seals between the distribution space and a combustion chamber that can communicate with the distribution space, and the seal tape bursts only by the pressure of the combustion chamber that communicates with the distribution space. The gas generator for an air bag according to any one of claims 11 to 13. 15. One of the two combustion chambers is provided inside an inner cylinder member disposed in the gas generator, and the other combustion chamber is radially outside the inner cylinder member. The gas generator for an air bag according to any one of claims 1 to 14, wherein the gas generator is provided in the. 16. The airbag gas according to claim 15, wherein the combustion chamber provided inside the inner tubular member and the other combustion chamber are provided concentrically and are adjacent to each other in the radial direction. Generator. 17. The inner cylinder member is partitioned into two chambers adjacent to each other in the axial direction by a partition wall extending in the radial direction, and the gas exhausted inside the two chambers partitioned inside the inner cylinder member. The chamber closer to the outlet is a combustion chamber, and the other chamber is an ignition means accommodating chamber for accommodating the ignition means.
A gas generator for an air bag according to any one of claims 1 to 16. 18. A gas generator for an airbag, an impact sensor that senses a shock and operates the gas generator, an airbag that introduces and inflate gas generated by the gas generator, and the airbag. And a module case that accommodates the gas generator for the airbag, wherein the gas generator for the airbag is the gas generator for an airbag according to any one of claims 1 to 17.