JP2001106015A - Gas generator and airbag device for airbag - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To provide an airbag gas generator capable of appropriately adjusting the internal pressure during combustion of a transfer charge. SOLUTION: An air bag gas generating device in which an igniter and a transfer charge are contained in an ignition means storage chamber 8 and a filling density of the transfer charge 16a in the transfer charge storage chamber 15a is 0.1 to 5 g / cm ^3. vessel.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

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

[0002]

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

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

As a gas generating mechanism in such a gas generator, a gas generating mechanism in which a transfer charge is burned by an electric ignition type igniter and a gas generated by the resulting flame is burned is generally employed. At this time, since the space in which the transfer charge is stored and the combustion chamber in which the gas generating agent is stored are communicated by the hole closed by the seal tape, the flame generated by the combustion of the transfer charge breaks the seal tape. It is necessary to flow into the combustion chamber, but if the sealing tape is not ruptured smoothly in this case, the combustion of the gas generating agent will be adversely affected. Further, since the state of accommodating the transfer charge varies depending on the form of the gas generator, it is necessary to take measures according to the form.

An object of the present invention is to provide a gas generator for an air bag which can smoothly and stably perform combustion of a gas generating agent accompanying combustion of a transfer charge, and an air bag device using the same. And

[0006]

SUMMARY OF THE INVENTION According to the present invention, an ignition means operated by an impact and a combustion gas ignited and burned by the ignition means for inflating an airbag in a housing having a gas discharge port. An airbag gas generator containing a gas generating means, wherein the igniting means comprises an igniter and a transfer charge in an ignition means storage chamber, and a charge density of the transfer charge is 0.1%. 1-5g / cm
³ , preferably 0.5 to 1.5 g / cm ³ of an airbag gas generator.

[0007] By setting the charge density of the transfer charge in the predetermined range as described above, the flame of the igniter in the ignition means accommodating chamber during the transfer of the transfer charge can uniformly ignite the transfer charge. Since the combustion of the gas generating agent in the room is performed smoothly and stably, the reliability of the product is improved.

Further, the present invention provides an ignition means which is activated by an impact, and a gas generation means which is ignited and burned by the ignition means to generate a combustion gas for inflating an airbag in a housing having a gas discharge port. An airbag gas generator containing and containing an igniter and a transfer charge in an ignition means accommodation chamber,
The charge density of the transfer charge is 0.1 to 5 g / cm ³ , preferably 0.5 to 1.5 g / cm ³ , and the space (A) occupied by the transfer charge in the ignition means storage chamber and the ignition means storage chamber And a ratio [(A + B) / A] to the remaining space volume (B) is 1.05 to 20, preferably 1.5 to 3.

By setting the ratio of the space volume occupied by the explosive and the remaining space volume not accommodating the explosive in the ignition means accommodating chamber to a predetermined range together with the charge density of the explosive in this manner, As the combustion proceeds, the transfer charge can be ignited more uniformly, so that the subsequent combustion of the gas generating agent in the combustion chamber is performed smoothly and stably, thereby improving the reliability of the product.

In each of the above gas generators, two or more combustion chambers for accommodating gas generating means are arranged in a housing, and two or more combustion chambers are ignited and burned in each of the two or more combustion chambers. The present invention can also be applied to an apparatus having a structure in which the ignition means is arranged, and of course, an apparatus having one combustion chamber and one igniter.

The gas generating means is for inflating an airbag for restraining an occupant with the combustion gas generated by the combustion. Therefore, the ignition means is ignited and burned by the igniter, and the combustion gas generated by the combustion of the transfer charge for burning the gas generation means burns the gas generation means, and directly burns the airbag. The two can be clearly distinguished in that they are not intended to be inflated.

Further, in that the combustion chamber provided in the housing is a chamber exclusively for accommodating gas generating means, the ignition means is configured to include a transfer charge, and the transfer charge is defined. Even if housed in the space, the chamber for accommodating the explosive and the combustion chamber for accommodating the gas generating means,
It can be clearly distinguished.

In the gas generator for an air bag according to the present invention, components other than the above-mentioned solving means are not particularly limited, and the same components as those of a known air bag gas generator are employed. It also includes modifications commonly made by those skilled in the art in their components.

For example, when the igniting means for igniting and burning the gas generating means includes two or more igniters operated by an impact, the igniters are connected to each other in order to facilitate the mounting. It is desirable to be provided on one initiator collar with the axial direction aligned.

In the case where there are two or more igniters, the transfer charge included in the ignition means is divided for each igniter and ignited and burned independently for each igniter. It is desirable to form so that the burned flame of the transfer charge corresponding to the igniter does not directly ignite the transfer charge corresponding to another igniter. As such a structure, for example, each igniter is disposed in an independent ignition means accommodating chamber, and a transfer charge is disposed in the ignition means accommodating chamber, or each ignition chamber is provided in a separate and independent combustion chamber. It can be placed at a place where it can be ignited and burned by the operation of the vessel.

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

As the gas generating means, in addition to an azide-based gas generator based on an inorganic azide, for example, sodium azide (sodium azide), which has been widely used, a non-azide-based gas generator not based on an inorganic azide is used. can do. However, in consideration of safety, a non-azide-based gas generating agent is desirable. As such a non-azide-based gas generating composition, for example, a nitrogen-containing organic compound such as tetrazole, triazole, or a metal salt thereof and an alkali metal Those containing an oxygen-containing oxidizing agent such as nitrate as a main component, triaminoguanidine nitrate, carbohydrazide, nitroguanidine, etc. as a fuel and a nitrogen source, and an alkali metal or alkaline earth metal nitrate, chlorate as an oxidizing agent, Various compositions such as a composition using perchlorate can be used.

In addition, the gas generating means is appropriately selected according to the requirements such as the burning rate, non-toxicity, burning temperature and decomposition start temperature. When using gas generating means having different combustion rates for each combustion chamber, for example, the composition and composition ratio itself, such as using an inorganic azide such as sodium azide or a non-azide such as nitroguanidine as a fuel and a nitrogen source, etc. In addition to using different gas generating means, changing the shape of the composition such as a pellet, a wafer, a hollow column, a disk, a single-hole or a porous body, or depending on the size of the molded body, etc. Gas generating means having a different surface area can be used. In particular, when the shape of the gas generating means is formed in a porous body having a plurality of through-holes, the arrangement of the holes is not particularly limited. An arrangement structure in which the distance between the portion and the center of the hole and the distance between the centers of the holes are substantially equal is desirable. Specifically, for example, in the case of a cylindrical molded body having a circular cross-section, one having a center at the center and six having a hole center at the apex of an equilateral triangle equidistant from each other. Is preferred. One more in the center and 18 around
An arrangement with individual holes is also conceivable. The number and arrangement of these holes are determined by the ease of manufacturing the gas generating agent and the balance between manufacturing cost and performance, and are not particularly limited. The transfer charge may be the same as the gas generating means described above.

The housing peripheral wall may further contain a coolant means for cooling the combustion gas generated by the combustion of the gas generation means. The coolant means is provided in the housing for the purpose of cooling and / or purifying the combustion gas generated by the combustion of the gas generating means. For example, a filter for purifying the 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 laminated wire mesh coolant is desirably formed by forming a flat knitted stainless steel wire mesh into a cylindrical body, and repeatedly bending one end of the cylindrical body outward to form an annular laminated body. A compression-molded or flat-knit stainless steel wire mesh is formed in a cylindrical body, and this cylindrical body is pressed in the radial direction to form a plate body, and the plate body is wound into a cylindrical shape in multiple layers to form a laminate. And compression molding in a mold or the like. Further, the inside and the outside may be formed as a double structure with different laminated metal nets, and may have a function of protecting the coolant means on the inside and a function of suppressing the expansion of the coolant means on the outside. By supporting the outer periphery of the coolant means with an outer layer made of a laminated metal mesh, a porous cylinder, an annular belt, or the like, the swelling can be suppressed.

Further, when two or more combustion chambers are formed, the combustion gas generated by the combustion of the gas generating means housed in each combustion chamber reaches the gas outlet through a different flow path for each combustion chamber. When the gas generating means accommodated in one combustion chamber is a gas generator which is not directly ignited by the combustion gas generated in another combustion chamber, the gas generating means in each combustion chamber is Since the combustion is completely independent of each combustion chamber, the ignition and combustion of the gas generating means housed in each combustion chamber can be performed more reliably and independently.
As a result, even when the operation timings of the two igniters are considerably shifted, the flame of the gas generating means in one combustion chamber ignited by the first igniter operates, Does not burn, and a stable operation output can be obtained. Such a gas generator can be performed, for example, by arranging a flow path forming member in a housing to form a flow path, and guiding the combustion gas generated in one combustion chamber to the coolant means as it is.

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

As the ignition means housed in the housing, 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 detects an impact. You. 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) which 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.

[0024]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a gas generator for an air bag according to the present invention will be described based on an embodiment shown in the drawings.

[Embodiment 1] FIG. 1 is a longitudinal sectional view of a first embodiment of a gas generator for an air bag according to the present invention, and has a structure particularly suitable for being arranged on a driver's seat side. ing.

This gas generator comprises a substantially cylindrical inner cylinder member in a housing 3 in which a diffuser shell 1 having a gas outlet and a closure shell 2 forming an internal storage space together with the diffuser shell. The first combustion chamber 5a is disposed outside the first combustion chamber 5a.

Further, a stepped portion 6 is provided inside the inner cylinder member 4, and a substantially plate-shaped circular partition 7 is disposed in the stepped portion, and the partition partitions the interior of the inner cylinder into two chambers. The second combustion chamber 5b is formed on the diffuser shell side, and the ignition means housing chamber 8 is formed on the closure shell side.

As a result, in this gas generator, the first combustion chamber 5a and the second combustion chamber 5b are provided concentrically within the housing 3 and are adjacent to the housing in the radial direction. In the first and second combustion chambers, gas generating agents 9a and 9b that are burned by ignition means operated upon receiving an impact and generate combustion gas are accommodated.
An ignition means operated by an impact is accommodated.

The inner cylinder member 4 defining the first combustion chamber 5a and the second combustion chamber 5b is provided with a through hole 10 which is closed by a seal tape 11. However, since the seal tape 11 bursts when the gas generating agent burns, the two combustion chambers can communicate with each other through the through holes 10. The material and thickness of the seal tape 11 are adjusted so that the seal tape 11 is not broken by the combustion of the gas generating agent 9a in the first combustion chamber 5a and is broken when the gas generating agent 9b in the second combustion chamber 5b is burned. There is a need. In this embodiment, a 40 μm-thick stainless steel sealing tape is used. The through hole 10 has an opening area larger than that of the gas outlet 26b, and does not have a function of controlling the internal pressure in the combustion chamber 5b.

In the present embodiment, the ignition means accommodating chamber 8 is defined by a space between the initiator collar 13 and the partition 7, and any one of the igniters 12b (hereinafter, "second igniter") ) To surround the separation cylinder 14 in a substantially cylindrical shape.
The first explosive charge accommodating chamber 15a is defined on the outside, the second explosive charge accommodating chamber 15b is defined on the inside, and igniters 12a and 12b, and the igniter together with the igniter Explosives 16a and 16b constituting the means are accommodated. In this embodiment, there is no remaining space in the ignition means accommodating chamber 8 except for the transfer charge accommodating chambers. As a result, the ignition means accommodation chamber 8
Are the first charge storage chamber 15a and the second charge storage chamber 15b
And the transfer charges 16a, 16b constituting the ignition means together with the igniter are surely divided for each of the igniters 12a, 12b.

When the transfer charge 16a contained therein burns, the first transfer charge storage chamber 15a ruptures the seal tape 18 that closes the transfer hole 17 formed in the inner cylindrical member 4, and the first transfer charge storage chamber 15a ruptures. And ignites and burns the porous gas generating agent 9a. The second charge storage chamber 15b is provided with a transfer hole 19 formed in the partition wall 7 when the charge 16b stored therein burns.
The seal tape 20 that closes off the rupture and communicates with the second combustion chamber 5b to ignite and burn the single-hole gas generating agent 9b. The combustion gas generated in the second combustion chamber 9b flows into the first combustion chamber 5a through the through hole 10 provided on the diffuser shell 1 side of the inner cylinder member 4. Therefore, when the gas generator operates, the flame when the first igniter 12a is ignited ignites the transfer charge 16a in the storage chamber 15a.
The flame is burned, and the flame is formed in a transfer hole 17 formed in the inner cylinder member 4.
And ignites and burns the seven-hole gas generating agent 9a accommodated in the first combustion chamber 5a located in the radial direction of the accommodation chamber 15a.

In this embodiment, the charge density of the transfer charge in the ignition means storage chamber 8, that is, the first transfer charge storage chamber 15
Packing density of transfer charge 16a in a and second transfer charge storage chamber
The packing density of each transfer charge 16b in 15b (weight of each transfer charge / volume of each charge storage chamber cm ³ ) is set to 0.5 to 1.5 g / cm ³ .

By setting the charge density of the transfer charge within the above range, the internal pressure of each transfer charge storage chamber (= each ignition means storage chamber) at the time of combustion of each transfer charge can be appropriately maintained. Thus, the gas generating agents 9a and 9b are smoothly and stably burned by the rupture of the seal tapes 17 and 20, respectively.

In the gas generator shown in FIG. 1, the second igniter 12b and the first igniter 12a may be ignited simultaneously to stabilize the operation performance, but the former 12b is earlier than the latter 12a. Does not work. That is, the gas generating agent 9b accommodated in the second combustion chamber 5b burns simultaneously with or after the gas generating agent 9a accommodated in the first combustion chamber 5a. When the gas generating agent 9a in the first combustion chamber 5a burns before the second gas generating agent 9b, the seal tape 11 is not broken by the combustion of the first gas generating agent 9a, and the second gas generating agent It is broken only by burning of the agent 9b.

Such an operation is also performed by setting the packing density of each transfer charge within a predetermined range, and the thickness and strength of the sealing tape can be changed as appropriate together with the packing density.

Also, in the gas generator shown in FIG. 1, the separation cylinder 14 disposed between the initiator collar and the partition has a hole corresponding to the outer shape of the separation cylinder 14 on the lower surface of the partition 7 and the upper surface of the initiator collar 13. Parts, and separate cylinders 14
Are arranged with the upper end or lower end thereof fitted. By arranging the separation tube 14 in this manner, the flame of the transfer charge generated in any one transfer charge combustion chamber does not directly burn the transfer charge in the other transfer charge accommodating chamber. The gas generating agents accommodated in the combustion chamber are ignited and burned by the flames in which the different types of transfer charges burn. That is, when a transfer charge is burned in the separation tube 14 (that is, in the second transfer charge accommodating chamber), the pressure of the gas generated by the combustion usually causes the separation tube to spread in the radial direction. However, by arranging the separation tube, the upper and lower ends of the separation tube are surely supported by the peripheral walls of the holes into which the separation tubes are fitted, and the separation tube is simply moved between the partition wall and the initiator collar. Leakage of the combustion gas / flame of the transfer charge can be more reliably prevented as compared with the case where it is sandwiched between them.

The ignition means includes two electric ignition igniters (12a, 12b) which are activated by an activation signal outputted based on the fact that the sensor detects an impact,
The igniters are provided on one initiator collar 13 in parallel with each other with their heads protruding. In this manner, two igniters (12a, 12a
By providing b), the two igniters are fixed to the initiator collar 13 to be a single member, and can be easily assembled to the gas generator. In particular, in the gas generator shown in this figure, the initiator collar 13 having two igniters (12a, 12b) is formed by making the initiator collar 13 large enough to be inserted into the inner cylinder member 4. After being inserted into the inner cylinder 4, the lower end of the inner cylinder member 4 is swaged to fix the initiator collar, so that the igniter can be easily and surely fixed. Further, when the two igniters (12a, 12b) are arranged on the initiator collar 13, the directions of the respective igniters can be easily regulated.

In the housing 3, a gas generating agent (9
a, 9b) is provided with a common coolant filter 22 for purifying and cooling the combustion gas generated by the combustion, and the inner peripheral surface of the diffuser shell 1 is provided with the end face of the coolant filter 22 and the diffuser. The shell 1 is covered with a short path preventing member 23 so that the combustion gas does not pass between the inner surface 28 and the ceiling. Outside the coolant / filter 22, an outer layer 24 for suppressing swelling of the filter 22 due to passage of combustion gas or the like is arranged.
The outer layer 24 is formed using, for example, a laminated metal mesh body, a porous cylindrical member having a plurality of through holes in a peripheral wall surface, or a belt-shaped restraining layer formed by annularly forming a band member having a predetermined width. You can also. Further, on the outside of the outer layer 24,
A gap 25 is formed so that the combustion gas can pass through the entire surface of the filter 22. The gas outlet 26 formed in the diffuser shell is closed by a seal tape 27 to prevent the outside air from entering. This sealing tape
27 bursts when releasing gas. The purpose of the seal tape 27 is to protect the gas generating agent from external moisture,
It does not affect performance adjustment such as combustion internal pressure at all.

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

Embodiment 2 FIG. 2 is a longitudinal sectional view showing another embodiment of the gas generator for an air bag of the present invention. This gas generator has a structure particularly suitable for being arranged on the passenger side.

The gas generator shown in FIG. 2 has a cylindrical shape whose axial center is longer than the outermost diameter and has an ignition operated by an impact in a housing 103 having a plurality of gas outlets on its peripheral wall. Means, a gas generating agent (9a, 9b) which is ignited and burned by the ignition means to generate a combustion gas for inflating the airbag, and cooling and / or purifying the combustion gas generated by the combustion of the gas generating agent And a coolant / filter 122. And housing 1
Two combustion chambers (105a, 105b) provided in 03 are formed as a cylindrical combustion chamber 105a and an annular combustion chamber 105b, and are provided coaxially adjacent to the housing 103 in the axial direction. A communication hole 110 is provided to enable the respective combustion chambers (105a, 105b) to communicate with each other.

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

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

A substantially cylindrical coolant / filter 122 is provided in the housing 103 so as to face the inner peripheral surface of the housing where a plurality of gas discharge ports 126 are formed. A predetermined gap 125 is ensured between the circumference. This coolant filter 1
A first combustion chamber 105a is defined adjacent to a space in which the first combustion chamber 105 is accommodated, and ignition means including two igniters (12a, 12b) is provided in the first combustion chamber 105a. Adjacent and coaxially disposed. And in the radial direction of the ignition means,
Since the annular second combustion chamber 105b is defined, the first combustion chamber 105a and the second combustion chamber 105b
3 will be provided adjacent to each other in the axial direction. Different gas generating agents (9
a, 9b) are filled, and in the gas generator shown in this figure, the first combustion chamber 105a has a porous cylindrical first gas generating agent 9a, and the second combustion chamber 105b has a single hole. The cylindrical second gas generating agents 9b are respectively stored.

The ignition means is provided in the ignition means accommodation chamber 8.
The igniter (12a, 12b), the ignition device (12a, 12b) is ignited and burned by the operation of the ignition, and comprises a transfer charge that ignites the gas generating agent (105a, 105b) with the flame, The transfer charge is defined for each igniter and ignites and burns independently for each igniter. The space for accommodating the transfer charge defined for each igniter is defined by a cylindrical member,
First transfer charge storage chamber 115a in which first transfer charge 116a is stored
Is a partition wall disposed between the ignition means and the first combustion chamber 105a.
The second transfer agent storage chamber 115b, which communicates with the first combustion chamber 105a at 107 of the transfer hole 119 and stores the second transfer agent 116b, is connected to the cylindrical member 104 defining the storage chamber 115b. Fire hole 117 formed
Communicates with the second combustion chamber 105b. The fire hole 119 is closed by the seal tape 20, and the fire hole 117 is closed by the seal tape 18. And the first combustion chamber 10
5a and the second combustion chamber 105b, the seal tape 11 that closes the through hole 110 formed in the partition wall 107 is ruptured by the combustion of the second gas generating agent 9b, the through hole 11
Communication will be performed at 0.

In the present embodiment, the charge density of the transfer charge in the ignition means storage chamber 8, that is, the first transfer charge storage chamber 11
5a and the packing density of the transfer charge 116b in the second transfer charge storage chamber 115b (each transfer charge weight g).
/ Each charge storage chamber volume cm3) is 0.5 to 1.5 g / c
It is set to m ^3.

By setting the charge density of the transfer charge within the above range, the internal pressure of each transfer charge accommodating chamber (= each ignition means accommodating chamber) at the time of combustion of each transfer charge can be appropriately maintained, and the respective seals can be sealed. The burning of the gas generating agents 9a, 9b due to the rupture of the tapes 18, 20 is performed smoothly and stably.

In the gas generator shown in FIG. 2, the first igniter
When 12a is activated, the transfer charge 116 in the first transfer charge storage chamber 115a
a is ignited and burns, and the flame is transferred to the
Through the gas generating agent disposed in the first combustion chamber 105a
9a is ignited and burned to generate combustion gas. This combustion gas is purified and cooled while passing through the coolant / filter 122, and is discharged from the gas outlet 126.

On the other hand, when the second igniter 12b operates, the transfer charge 116b in the second transfer charge storage chamber 115b ignites and burns,
The flame ignites the gas generating agent 9b in the second combustion chamber 105b.
Burn. The combustion gas generated in the second combustion chamber 105b passes through the through hole 110 of the partition 107, and the first combustion chamber 105a
The gas is purified and cooled while passing through the coolant filter 122 and is discharged from the gas outlet 126. The combustion gas generated by the combustion of the first gas generating agent and the combustion gas generated by the combustion of the second combustion gas are both purified and cooled while passing through the same coolant filter 122.

In this embodiment, the gas outlet 126
Is closed by a seal tape 127. The seal tape 127 is intended to protect the gas generating agent from external moisture, and is ruptured by a combustion gas generated by the combustion of the gas generating agent, so that the combustion gas can be released.
Therefore, the seal tape 127 does not control the combustion performance (combustion internal pressure) of the gas generating agent.

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

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

In connection with the embodiment shown in FIG.
The two combustion chambers provided in the housing may be provided so as to be adjacent in the axial direction and the radial direction of the housing.

Embodiment 3 FIG. 3 is a longitudinal sectional view showing still another embodiment of the gas generator for an air bag according to the present invention. The gas generator shown in this figure has a structure which is particularly suitable for being arranged on the driver's seat side, similarly to the gas generator shown in FIG.

Also in the gas generator shown in FIG. 3, the first combustion chamber 305a and the second combustion chamber 305b are defined by the inner cylinder member 304 and are concentrically adjacent to each other in the housing 3. It is provided. A stepped portion 306 is provided at a predetermined height on the inner peripheral surface of the inner cylindrical member 304, and the stepped portion 306 defines a second combustion chamber 305b and an ignition means accommodating chamber 308. A partition 307 is provided.

In the present embodiment, this partition 307
As shown in the exploded perspective view of FIG. 4, a partition circular member 350 that is engaged with the stepped portion 306 of the inner cylindrical member 304, and the partition circular member 35
And a seal cup member 360 that engages with the seal cup member 360.
The partitioning circular member 350 has a substantially flat circular shape, and has an opening 351 in which a transfer agent accommodating chamber 361 of the seal cup member 360 described later is internally fitted, and a bottom surface is hollowed out in a circular shape. It has a circular hole 352 to be accommodated, and a second heat transfer hole 319 penetrating substantially through the center of the circular hole.
In addition, the seal cup member 360 includes a cylindrical transfer charge accommodating chamber 361 that fits into the opening 351 of the section circular member 350 and protrudes into the second combustion chamber 305b, and a circular hole of the section circular member 350. It has a tubular igniter accommodating port 362 formed at a position facing the portion 352 and extending on the opposite side to the transfer charge accommodating chamber 361. Inside the explosive charging chamber 361, the first explosive 316
a is accommodated, and a second igniter 312b is fitted in the igniter accommodation opening 362. The partition circular member 350 and the seal cup member 360 are engaged by fitting the transfer charge storage chamber 361 of the seal cup member 360 into the opening 351 of the partition circular member 350, and The upper part of the second igniter 312b fitted inside is the circular hole 3 of the section circular member 350.
It protrudes into 52.

The circular section 350 and the seal cup member 360
As shown in FIG. 3, the inner wall member 304
Is locked by a stepped notch 306 formed on the inner peripheral surface of the base. That is, the periphery of the sectioned circular member 350 is supported by the stepped portion 306,
The seal cup member 360 is supported in contact with the section circular member 350. The periphery of the seal cup member 360 is formed by bending in the same direction as the igniter accommodating port 362, and the bent portion 363 fits into a groove 364 provided on the inner circumferential surface of the inner cylinder member 304. are doing. As a result, the circular section 350 is supported by the seal cup member 360, and the axial movement of the housing 3 is prevented. Also, the bent portion 363 of the peripheral edge of the seal cup member 360 is
By fitting into the groove 364 on the inner peripheral surface, the partition wall 307 (that is, the seal cup member 360) and the inner cylinder member 304 are engaged without any gap. Therefore, in the inner cylinder member 304, the ignition means accommodating chamber 308 provided on the closure shell 2 side and the second combustion chamber 305b provided on the diffuser shell 1 side are:
It is reliably partitioned by an ignition means seal structure composed of a combination of the seal cup member 360 and the groove 364.

The igniter accommodating port 362 formed in the seal cup member 360 has a skirt portion opened in a skirt shape, and the inside thereof, that is, the second igniter 312 accommodated in the accommodating port 362 is provided.
An O-ring 381 is arranged between the second igniter 312b and the housing 362, and an O-ring 381 is provided between the housing 362 and the second igniter 312b. Further, since the O-ring 381 is also in pressure contact with an igniter fixing member 382 described later, the second igniter 312b is provided with a circular hole 352 of the section circular member and an igniter accommodating port of the seal cup member. 362-O-ring 381-arranged in a space defined by igniter fixing member 382. In this partitioned space, the second igniter 312b is operated, so that the second heat transfer hole 319 formed in the circular hole 352 of the partitioned circular member 350 is formed.
The sealing tape 320 that ruptures the second combustion chamber 305
Communicate with b. And the first igniter 312a and the second igniter 3
12b is securely separated from each other by a seal structure (hereinafter, referred to as an “igniter seal structure”) including a skirt portion of an igniter accommodating port 362, an O-ring 381, and an igniter fixing member 382.
Thus, the flame generated by the operation of any one of the igniters does not directly flow into the space in which the other igniters are accommodated.

In the space (the space separated by the igniter seal structure) in which the first igniter 312a is disposed in the ignition means accommodating chamber 380, the first transfer charge 316a is provided.
It is housed in 361 and there is a remaining space 390 in said space.

In the present embodiment, the transfer charge accommodating chamber 36
The packing density of the first transfer charge 316a in 1 is 0.5 to 0.5
It is set to 1.5 g / cm ³ . 1st transfer charge 3
16a occupied space volume (= volume of explosives storage chamber 361) (A)
And the ratio of the volume (B) of the remaining space 390 [(A +
B) / A] is set to 1.5 to 3.

The charge density of the transfer charge and the ratio [(A + B)
/ A] within the predetermined range, the internal pressure of the ignition means accommodating chamber 8 during the combustion of the first transfer agent 316a can be properly maintained, and the gas generating agent 309a due to the rupture of the seal tape 318 can be maintained. Combustion is performed smoothly and stably.

In the operation of the gas generator shown in this embodiment, the flame generated by the operation of the first igniter 312a is:
The first transfer charge 316a disposed above is ignited and burned. The flame generated by the combustion of the first transfer charge 316a is supplied to the second igniter 31 by the igniter seal structure.
The second combustion chamber 305b does not flow into the space in which the second combustion chamber 305b is accommodated, and the ignition means seal structure including the bent portion 363 of the seal cup member 360 and the groove 364 of the inner cylinder member 304.
There is no inflow. Therefore, this first transfer charge 31
The flame generated by the combustion of 6a passes through the first heat transfer hole 317 formed in the peripheral wall of the inner cylinder member 304, flows exclusively into the first combustion chamber 305a, and flows through the first gas generating agent 309a. It ignites and burns to generate combustion gas.

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

Then, the combustion gas generated by the combustion of the first gas generating agent 309a and the second gas generating agent 309b is purified and cooled while passing through the common coolant filter 22, and the gap 25 Through the gas outlet 26. The seal tapes 318 and 320 closing the first and second transfer holes burst when the flame of the igniter or the combustion gas of the transfer charge passes, and the seal tape 27 closing the gas discharge port 26 has the combustion gas. Explodes when passing.

Also in this embodiment, the two igniters 312a and 312b are fixed to a single initiator collar 313 in order to ensure the ease of arrangement in the housing. In particular, in the present embodiment, the two igniters 312a and 312b are supported by an igniter fixing member 382 that engages with the initiator collar 313 and are fixed to the initiator collar 313. The igniter fixing member 382 is shaped so as to cover the upper surface of the initiator collar 313, and has a hole 384 for inserting the upper part of each igniter and supporting the shoulder 383. The two igniters 312a and 312b arranged on the initiator collar 313 are connected to the initiator collar 313.
The igniter is fixed to an igniter fixing member 382 which is fitted to the outside. By using such an igniter fixing member 382, the two igniters 312a and 312b can be easily combined with the initiator collar 313. Note that, in the gas generator shown in this embodiment, the first igniter 312a and the second igniter 31
Although an igniter having a different operation output is used, the igniter having the same operation output can be used.

Also in the gas generator shown in this embodiment, the first gas generating agent 309a is operated by the first igniter 312a, and the second gas generating agent 309b is operated by the second gas generator 309b. Igniter 31
According to the operation of 2b, each is ignited and burned independently, but in some cases, current is passed only to the first igniter 312a and ignited, and only the gas generating agent 309a in the first combustion chamber 305a is ignited.・ May be burned. That is, the second gas generating agent 309b
And the second igniter 312b is left without burning.
In such a case, inconvenience will occur during subsequent processing and disposal, etc., so that after the gas generator (only the first igniter 312a) is activated, the normal delayed ignition in which the second igniter 312b is activated It is desirable to burn the gas generating agent 309b in the second combustion chamber 305b at a later timing (for example, 100 ms or more) than the timing (for example, 10 to 40 milliseconds).

Therefore, an auto-ignition material that ignites and burns by conduction of the combustion heat of the first gas generating agent 309a can be arranged in the second combustion chamber 305b. In this case, the ignition of the second gas generating agent 309b by the auto-ignition material is delayed by a predetermined time after the operation of the first igniter 312a, and the second igniter is fired.
This operation is performed after a lapse of a time longer than a normal delay time for activating the 312b (that is, an operation interval between the igniters). That is, this is different from delaying the combustion of the second gas generating agent 309b (that is, delaying the operation of the second igniter 312b) for the purpose of adjusting the operation performance of the gas generator. The second gas generating agent 309b is ignited and burned by the autoignition material while optionally delaying the operating current to the second igniter 312b to adjust the operating performance of the gas generator. Nor. This auto-ignition material can be arranged in combination with the second igniter.

The first combustion chamber 305a and the second combustion chamber 305b are defined by the inner cylinder member 304. The inner cylinder member 304 is provided with a through hole 310, and the through hole 310 is closed by a stainless plate 311. The stainless steel plate 311 is fixed to the inner cylindrical member 3 by an adhesive member such as an adhesive.
The first gas generating agent 309a does not open the through-hole 310 only when the second gas generating agent 309b is burned. In this way, the through hole 310
Is closed by the stainless steel plate 311 because the first gas generating agent 3
This is to prevent the burned flame of 09a from flowing into the second combustion chamber 305b through the through hole 310 and burning the second gas generating agent 309b.

Therefore, as long as such a function can be ensured, in addition to closing the through-hole 310 with the stainless steel plate 311, the through-hole 310 is ruptured, peeled, burned out or detached by the pressure due to the combustion of the second gas generating agent. Such a rupture plate is welded, adhered or heat-sealed to the inner cylinder member to close the through hole 310, or a notch is provided in the peripheral wall of the inner cylinder member 304, or the thickness of the peripheral wall of the inner cylinder member 304 is partially It can also be realized by forming it as thin as possible.

Further, a through hole 310 provided in the inner cylindrical member 304 is provided.
, A substantially ring-shaped shielding plate can be arranged on the first combustion chamber 305a side. When the substantially ring-shaped shield plate is disposed as described above, even if combustion gas is generated by the combustion of the first gas generating agent 309a, the seal tape that closes the through hole 310 is protected by the shield plate. Therefore, the first gas generating agent 309a does not burst due to combustion.

Also in the present embodiment, the through hole 310 of the inner cylinder member 304 is opened only by the combustion of the second gas generating agent 309b, and is not opened by the combustion of the first gas generating agent 309a. Therefore, even if combustion gas is first generated in the first combustion chamber 305a, this does not flow into the second combustion chamber 305b, and the gas generating agent 309b in the second combustion chamber 305b
Is ignited and burned by the operation of the second igniter 312b (in some cases, the combustion of the auto-ignition material). The combustion gas generated by the combustion of the second gas generating agent 312b passes through the through hole 310 opened by the combustion, passes through the first combustion chamber 305a, and is then purified and cooled by the coolant filter 22. The gas is discharged from the gas outlet 26.

Fourth Embodiment FIG. 5 is a longitudinal sectional view of a first embodiment of a gas generator for an air bag according to the present invention, and has a structure particularly suitable for being arranged on a driver's seat side. ing. In the present embodiment, the combustion chamber is a single gas generator.

This gas generator is provided with a substantially cylindrical inner cylinder member in a housing 3 in which a diffuser shell 1 having a gas outlet and a closure shell 2 forming an internal storage space together with the diffuser shell are joined. A combustion chamber 422 is disposed outside the 413, and an ignition means housing chamber 455 is disposed inside the combustion chamber 422.

As a result, in this gas generator, the combustion chamber 42
2 and the ignition means housing chamber 455 are provided concentrically within the housing 3 and are adjacent to the housing in the radial direction.
In this combustion chamber, a gas generating agent 406 that is combusted by an ignition means operated upon receiving an impact and generates combustion gas is accommodated, and an ignition means operated by an impact is accommodated in an ignition means accommodation chamber 455. I have.

In the ignition means accommodating chamber 455, an igniter 404 is installed via an initiator collar 414, and the explosive 405 is accommodated in the ignition means accommodating chamber 423. A space 460 exists.

In the present embodiment, the transfer charge accommodating chamber 42
3. The packing density of the first transfer agent 405 in 3 is 0.5 to 1.
It is set to 5 g / cm ³ . Further, the ratio [(A + B) / A] of the occupied space volume of the explosive charge 405 (= the volume of the explosive charge accommodating chamber 423) (A) to the volume (B) of the remaining space 460 becomes 1.5 to 3. Is set.

The charge density of the transfer charge and the ratio [(A + B)
/ A] within the predetermined range, the internal pressure of the ignition means accommodating chamber 455 during the combustion of the transfer agent 405 can be appropriately maintained, and the combustion of the gas generating agent 406 due to the rupture of the seal tape 427 is reduced. Smooth and stable.

In FIG. 5, reference numeral 407 denotes a coolant filter,
Indicates a gap, 411 indicates a gas discharge hole, 425 indicates a seal tape, 426 indicates a communication hole, and 450 indicates a short path prevention member.

[Embodiment 5] FIG. 6 shows an embodiment of the airbag apparatus 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 500
, An impact sensor 501, a control unit 502, a module case 503, and an airbag 504. As the gas generator 500, the gas generator described with reference to FIG. 3 is used, and its operation performance is adjusted in the early stage of the gas generator operation so as to minimize impact on the occupant. ing.

The impact sensor 501 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 502 includes an ignition determination circuit, and a signal from the semiconductor acceleration sensor is input to the ignition determination circuit. When the shock signal from the sensor 501 exceeds a certain value, the control unit 502 starts the calculation, and when the calculation result exceeds a certain value, the igniters 312a and 312b of the gas generator 500
Outputs the operation signal to

The module case 503 is made of, for example, polyurethane, and includes a module cover 505. The module case 503 accommodates the airbag 504 and the gas generator 500 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 507.

The airbag 504 is formed of nylon (for example, nylon 66) or polyester, and its bag port 506 surrounds the gas discharge port of the gas generator, and is fixed to the flange of the gas generator in a folded state. Have been.

When an impact is detected by the semiconductor acceleration sensor 501 at the time of an automobile collision, the signal is sent to the control unit 502, and when the impact signal from the sensor exceeds a certain value, the control unit 502 starts calculation.
When the calculated result exceeds a certain value, an operation signal is output to the igniters 312a and 312b of the gas generator 500. Accordingly, the igniters 312a and 312b operate to ignite the gas generating agent, and the gas generating agent burns to generate gas. This gas is airbag
The airbag squirts into the 504, whereby the airbag breaks and bulges the module cover 505, forming a cushion between the steering wheel 507 and the occupant to absorb impact.

[0086]

According to the present invention, since the ignition combustion of the transfer charge in the ignition means is performed smoothly and stably, the subsequent combustion of the gas generating agent in the combustion chamber is also performed smoothly and stably. As a result, the reliability of the product can be further improved.

[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 longitudinal sectional view showing another embodiment of the gas generator of the present invention.

FIG. 3 is a longitudinal sectional view showing still another embodiment of the gas generator of the present invention.

FIG. 4 is a partially enlarged view of the gas generator of FIG. 3;

FIG. 5 is a longitudinal sectional view showing still another embodiment of the gas generator of the present invention.

FIG. 6 is a configuration diagram of an airbag device of the present invention.

DESCRIPTION OF SYMBOLS 3 Housing 8 Ignition means accommodating chamber 12a, 12b Ignition device 15a, 15b Transfer agent accommodating room 16a, 16b Transfer agent 115a, 115b Transfer agent accommodating room 116a, 116b Transfer agent 312a, 312b Ignition device 361 Room 316a Transfer charge 380 Ignition means storage chamber 390 Space 404 Igniter 405 Transfer charge 423 Transfer charge storage chamber 455 Ignition means storage chamber 460 Space

Claims (5)

[Claims] 1. A housing having a gas outlet including an ignition means operated by an impact, and a gas generation means ignited and burned by the ignition means to generate a combustion gas for inflating an airbag. The ignition means comprises an igniter and a transfer charge in an ignition means accommodating chamber, and a charge density of the transfer charge is 0.1 to 5 g / cm ³ . Gas generator for airbag. 2. A housing having a gas outlet including an ignition means operated by an impact, and a gas generation means ignited and burned by the ignition means to generate a combustion gas for inflating an airbag. A gas generator for an air bag, wherein the ignition means comprises an igniter and a transfer charge in the ignition means storage chamber, and the charge density of the transfer charge is 0.1 to 5 g / cm ³ ; And an airbag gas having a ratio [(A + B) / A] of 1.05 to 20 of the space volume (A) occupied by the transfer charge in the ignition means chamber and the remaining space volume (B) in the ignition means chamber. Generator. 3. The gas generator for an air bag according to claim 1, wherein the transfer charge is accommodated in a transfer charge storage chamber provided independently in the ignition means storage chamber. 4. In the housing, two or more combustion chambers for accommodating the gas generating means are arranged, and in the two or more combustion chambers, two or more ignition means for igniting and burning the respective gas generating means are arranged. The gas generator for an air bag according to claim 1, wherein the gas generator is an air bag. 5. A gas generator for an airbag, an impact sensor that senses an impact to activate the gas generator, an airbag that expands by introducing gas generated by the gas generator, and the airbag. And a module case accommodating the airbag, wherein the gas generator for an airbag is the gas generator for an airbag according to any one of claims 1 to 4.