JPH10203297A - Gas generator for air bag and air bag device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To fix a structure for mounting detonator such as a detonator piece within a housing by abutting the structure for mounting detonator on the peripheral wall surface and fixing the structure by welding burr which is generated and projected by friction welding of a member for which the friction welding is performed. SOLUTION: A housing 1 is formed by joining a diffuser shell 2 having a gas exhaust port 4 and a closure shell 3 having a storing port 7 of a sensor by friction welding. The inside of this housing 1 is sectioned into two chambers of an ignition means storing chamber 8 and a combustion chamber 9 by a bulkhead 22 joined by friction welding. Within the ignition means storing chamber 8, an ignition means constituted of a detonator piece 11 storing/fixing the detonator 10 within a recess 17, inflammation chemical 12 disposed in the vertical direction by holding the detonator piece 11 and a mechanical type sensor 6 is stored. The detonator piece 11 is fixed by projecting welding burr 23 projected on the side of the igntion means storing chamber 8 at the detonator piece 11 storing portion of the bulkhead 22 in a groove 31.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas generator for an airbag device used for reducing the impact on an occupant in the event of a vehicle collision, and more particularly to a gas generator operated by a mechanical sensor for sensing the impact by a mechanical mechanism. The present invention relates to a gas generator for an air bag, characterized in that it has a fixed structure of a primer mounting structure for accommodating and fixing a primer that ignites by being pierced by a firing pin.

[0002]

2. Description of the Related Art Conventional gas generators include an electric ignition type and a mechanical ignition type. The electric ignited gas generator ignites the transfer charge by the ignition of the igniter by the heat generated by the electric current, whereas the mechanically ignited gas generator uses the detonator by piercing a firing pin emitted from a mechanical sensor. Ignites and burns the transfer charge. Among them, a mechanical ignition type gas generator has an advantage that electric wiring and the like are not required and can be manufactured at low cost.

[0003] A general mechanical ignition type gas generator has an ignition means, that is, a mechanical sensor that senses an impact by a mechanical mechanism and fires a firing pin, and is pierced and fired by firing of the firing pin. It contains a primer containing a drug in a container and a transfer charge that ignites with the flame of the primer and burns a gas generating agent.The primer is ignited by the firing of a firing pin that is fired in response to impact detection. The flame is used to ignite and burn a transfer charge and a gas generating agent to generate combustion gas. This gas is cooled while passing through the coolant and filter.
It is purified and flows into the airbag from the gas outlet.

[0004] Usually, the above-mentioned primer is fixed in a container such as an aluminum can, which contains a chemical containing trisinate or the like, and covers the upper surface with a lid of an aluminum plate, and deforms the mouth of the can to fix the lid. A copper is placed inside a cup made of a copper alloy or copper alloy, and a tricinate-type chemical or the like sandwiched in a sheet is inserted between the cup and the cup, and a through hole is made in the cup ceiling surface where the firing pin hits. In some cases, a drug sandwiched between sheets is ignited by the firing of a firing pin, and the primer is located in a cavity formed at a location where a firing pin fired from a sensor pierces in a primer piece fixed in a housing. The firing pin must pierce the detonator and ignite.

In the past, this primer piece was fixed in a housing by being pressed into an ignition means accommodating chamber for accommodating ignition means such as a sensor, or by caulking or hooking the primer piece. .

On the other hand, the housing of the gas generator is generally formed by joining a diffuser shell having a gas discharge port and a closure shell closing the diffuser shell. For example, plasma welding, friction welding, projection welding, electron beam welding, laser welding, and TIG welding are performed. In particular, in the case of a gas generator for an airbag using a housing having an interior defined by two or more partitions, the diffuser shell and the closure shell, and the partition can be joined by a single operation. Among the various welding methods, friction welding is particularly desirable.

[0007] However, regarding this friction welding, since both members to be joined are melted by friction heat and welded and integrated,
An excess portion melted by the frictional heat is melted into the welded portion, and a welding burr is projected. Therefore, when designing the housing, it is necessary to secure a space necessary for the projection of the welding burr in advance, so the projection of the welding burr reduces the size of the gas generator for an air bag. Was an obstacle on top.

[0008] Such welding burrs are required.
In order to make unnecessary space smaller for the operation function of the gas generator, welding burrs protruded by friction welding can be scraped off. However, even if the welding burrs are scraped off, the shavings (welding burrs) may remain in the housing, and if the shavings remain in the housing, the normal operation of the gas generator is obstructed. It is also possible to bring. Further, in order to cut off welding burrs, a separate step is required, which hinders efficient production of an airbag gas generator.

[0009]

SUMMARY OF THE INVENTION Accordingly, the present invention solves the above-mentioned problems of the conventional gas generator for an air bag, and secures a space for welding burrs generated by friction welding, and the welding burrs. A gas generator for an airbag, which makes it possible to reduce the size of the whole by eliminating the step of removing the burrs and to make use of the projections of the welding burrs effectively without being adversely affected by the welding burrs. The purpose is to:

[0010]

A gas generator for an air bag according to the present invention is a gas generator for an air bag wherein a structure for mounting a primer, such as a primer piece, is fixed in a housing by welding burrs generated and projected by friction welding.

That is, the present invention includes a mechanical sensor that senses an impact and fires a firing pin, a detonator that is pierced by the firing pin and ignites, and an ignition means that includes a transfer charge that ignites and burns with the flame of the firing pin. In the mechanically ignited gas generator composed of: a primer mounting structure for accommodating and fixing the primer at the piercing point of the firing pin emitted from the sensor is brought into contact with the peripheral wall surface of the primer mounting structure, An airbag gas generator fixed by welding burrs generated and generated by friction welding of members to be welded.

A mechanically-ignited gas generator is a weight that is moved by an impact and urges the firing of a firing pin from a sensor.
A mechanical sensor that senses an impact exclusively by a mechanical mechanism and fires a firing pin, a primer that is pierced by a firing pin that is fired from the mechanical sensor, ignites and burns, and is ignited by the flame of the primer.
An airbag gas generator in which an ignition means comprising a burning transfer agent and a gas generating agent which burns to generate gas by the operation of the ignition means are housed in a housing having a gas outlet. This mechanical ignition type gas generator includes, for example, a coolant filter for cooling and purifying generated gas and a combustor for regulating the internal pressure of a housing during combustion of a gas generating agent, in addition to the ignition means and the gas generator. Known members used for conventional mechanical ignition gas generation, such as rings, can be housed and located within the housing. The gas generated by the mechanical gas generator is injected into an airbag (bag) from a gas outlet formed in the housing. In this mechanically ignited gas generator, during the igniting means, the primer is provided only with a primer mounting structure for fixing and supporting the primer, such as a primer piece. Fixed and supported at the piercing point. In the structure for mounting a primer, it is desirable that a heat transfer hole penetrating in the thickness direction is formed at a location where the primer is fixed.

In the gas generator for an air bag according to the present invention, as a member which is brought into contact with the peripheral wall surface of the structure for mounting the primer and is friction-welded, for example, the inside of the housing is divided by a partition into an ignition means housing chamber and a combustion chamber. Gas containing a mechanical sensor, a priming device, and a transfer charge contained in a igniting device containing chamber defined by the partition walls, and the priming device is fixed by a priming attachment structure. In the case of the generator, the partition corresponds to the inside of which the ignition means is housed. In this case, the partition is divided, and the diffuser shell and the closure shell forming the housing are formed integrally with each other, and the two shells are joined by friction welding, whereby the partition is fixed to the primer mounting structure, That is, it is joined at a predetermined location between the mechanical sensor to be accommodated and the transfer charge, and welding burrs by friction welding are projected at this location. Then, the primer mounting structure is fixed with the projected welding burrs. A primer is attached to the primer attachment structure fixed at the predetermined location. It is better to attach the primer separately after attaching the primer mounting structure.

The fixing of the primer mounting structure by welding burrs is performed by projecting welding burrs by friction welding on the peripheral wall surface of the primer mounting structure and / or the peripheral edge of the primer mounting structure on the sensor side. . When the welding burr is projected on the peripheral wall surface of the primer mounting structure, a welding burr receiving portion is formed in a circumferential direction of the peripheral wall of the primer mounting structure, and the welding burr is projected on the welding burr receiving portion. Thus, the primer mounting structure can be fixed. The welding burr accommodating portion protrudes, for example, a groove formed in the circumferential direction of the peripheral wall of the primer mounting structure, or a stepped portion formed on the sensor-side peripheral edge of the primer mounting structure. It can be formed in a known shape that can accommodate welding burrs. When the welding burr accommodating portion is a stepped notch, the surface of the welding burr projected in the stepped notch in the sensor direction is mechanically moved so that the projecting welding burr does not hinder the accommodation of the mechanical sensor. It is desirable to regulate by the welding burr regulating member inserted in the accommodation place of the sensor. As this welding burr control member,
A jig having substantially the same shape as the mechanical sensor housed in the ignition means housing chamber can be used.

In the above-mentioned welding burr receiving portion, a rotation preventing portion for preventing the rotation of the detonator mounting structure in the sensor is formed by housing the projecting welding burr in the receiving portion. Can also. As the rotation preventing portion having such a function, for example, a part of the welding burr accommodating portion,
Further, it can be formed by notching. In this case, since the projected welding burr projects into the cutout portion, the rotation of the primer mounting structure is prevented.

When the primer mounting structure is fixed by welding burrs projecting at the time of friction welding, the primer is housed and fixed in a recess or the like of the fixed primer mounting structure, so that the primer is securely inserted. A gas generator for an air bag in which a firing pin pierces a detonator is realized.

The housing having a gas discharge port is formed by pressing, casting or forging a diffuser shell having a gas discharge port and a closure shell having a sensor receiving port, and joining these two shells by friction welding. Formed. As described above, in the case where the primer mounting structure is fixed by the partition having the ignition means receiving chamber on the inner side, the partition divided at the location where the primer mounting structure is disposed on both shells, Each is integrally formed.

As the gas generating agent, known gas generating agents such as an azide-based gas generating agent and a non-azide-based gas generating agent can be used. Examples of the azide-based gas generating agent include those based on inorganic azides, particularly sodium azide (sodium azide), which have been widely used in the past, such as an equivalent mixture of sodium azide and copper oxide. As the main component, a nitrogen-containing organic compound such as tetrazole, triazole, or a metal salt thereof and an oxygen-containing oxidizing agent such as an alkali metal nitrate, triaminoguanidine nitrate, carbohydrazide, nitroguanidine, etc. There is a composition using a nitrogen source and an alkali metal or alkaline earth metal nitrate, chlorate, perchlorate or the like as an oxidizing agent. Considering safety and the like, non-azide gas generating agents are advantageous.

The coolant filter serves to remove combustion residues generated by the combustion of the gas generating agent and to cool the combustion gas. For example, stainless steel, SUS304, SUS310S, SUS316
A wire mesh made of (JIS standard symbol) or the like may be used as an annular laminate and compression molded. In addition, as for the filter coolant, a combination of a filter and a coolant that have been widely used in the past can be used.

In the gas generator according to the present invention, friction welding of a member, such as a partition wall, which comes into contact with the peripheral wall surface of the primer mounting structure is performed while the primer fixing structure is provided at a portion joined by the friction welding. It can be manufactured by performing. After the structure for mounting the primer is fixed by welding burrs of friction welding, the structure for mounting the primer can not be removed. In the case of blocking by the above, it is necessary to fix the primer mounting structure after accommodating the transfer charge in advance.

The gas generator of the present invention fires a firing pin when a mechanical sensor detects an impact, and the firing pin pierces the primer to ignite and burn. The primer flame is
The explosive charge is ignited and burned through a fire hole drilled in a primer fixing structure such as a primer piece. The flame of the transfer charge is
The gas is generated by igniting and burning the gas generating agent. The generated gas is cooled and purified by a coolant filter, and is injected into the airbag from a gas outlet of the housing.

Further, the gas generator for an airbag described above can be formed as an airbag device by combining an airbag that expands by introducing gas generated by the gas generator and a module case that houses the airbag. This airbag device is housed and fixed in an appropriate place in a vehicle such as a steering wheel or a dashboard.

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a longitudinal sectional view of a gas generator according to one embodiment of the present invention, FIG. 2 is an enlarged longitudinal sectional view of a main part showing a fixed state of a primer piece, and FIG. 3 is a fixed state of a primer piece according to another example. FIG. 4 is an enlarged cross-sectional view of a main portion showing a welding burr regulation state, FIG. 5 is a plan view of a primer piece showing a rotation preventing portion, and FIG. 6 is a configuration diagram of an airbag device. Each is shown.

The mechanical ignition type gas generator having a built-in mechanical sensor shown in FIG. 1 is obtained by joining a diffuser shell 2 having a gas discharge port 4 and a closure shell 3 having a sensor accommodating port 7 by friction welding. A housing 1 is formed. The interior of the housing 1 is separated from the combustion chamber 9 by the partition wall 22 joined by friction welding.
A priming piece 11 in which a priming 10 is accommodated and fixed in a recess 17 is defined in the ignition means accommodating chamber 8.
And an ignition means composed of a transfer charge 12 and a mechanical sensor 6 disposed vertically above and below the primer piece 11. The primer piece 11 is a primer piece 11 of the bulkhead 22.
Welding burr 23 projecting toward the ignition means housing chamber 8 at the housing location
Is fixed by projecting it into the groove 31.
In FIG. 1, reference numeral 5 denotes a seal tape for closing the gas discharge port 4 and the through hole 20 to prevent moisture, and reference numeral 21 denotes a combination ring.

The mechanical sensor 6 contains a weight (not shown) that moves due to the acceleration at the time of collision and a firing pin 18 that is prompted to fire by the movement of the weight. 19. The completed sensor 6 is completely in place of the firing pin 1 while the safety device 19 is operating.
8 is prevented and no malfunction occurs, so that the assembling process can be performed safely.
Until the mechanical sensor 6 is installed, there is no danger that the gas generator will be easily ignited, so that the production of the gas generator can be handled safely and easily.

The primer 10 housed and fixed in the recess 17 of the primer piece 11 contains a powdery tricinate-based chemical or the like. An aluminum tape 16 is attached to the opening of the recess 17 to protect the primer 10 from moisture. Combustion chamber 9
Inside, a non-azide-based gas generating agent 13 and a coolant 14 and a filter 15 of an annular wire mesh laminate made of stainless steel surrounding the gas generating agent are accommodated.

When the sensor 6 detects an impact, the gas generator fires a firing pin 18 housed therein, and the primer 10 accommodated and fixed in the recess 17 of the primer piece 11
Pierce. The blasting of the firing pin 18 ignites and burns the primer 10, and the flame ignites and burns the charge 12 through the transfer hole 24 of the primer piece 11. And gunpowder 1
The flame of No. 2 burns the gas generating agent 13 through the through hole 20 to generate gas. After the generated gas is cooled by the coolant 14, it is purified by the filter 15 and discharged from the gas outlet 4.

FIG. 2 is an enlarged longitudinal sectional view of a main part showing the fixed state of the primer piece 11. The primer piece 11 is disposed between the mechanical sensor 6 and the transfer charge 12, and its peripheral edge in the transfer charge direction. Is welded to the stepped portion 27 of the partition wall 22, and welding burrs 23 generated by friction welding of the partition wall 22 having the ignition means accommodating chamber 8 inside a groove 31 formed in the peripheral wall of the primer piece 11. Are supported and fixed by projecting. Then, the primer 10 is stored and fixed in the recess 17 of the fixed and stored primer piece 11. A groove 31 formed in the circumferential direction is formed on the peripheral wall of the primer piece 11. By projecting the welding burr 23 in the groove 31, the primer piece 11 is formed by the projected welding burr 23. It is supported and fixed in place. In addition, as shown in FIG. 3, the primer piece 11 has a stepped notch 32 formed in a stepped shape in the circumferential direction on the sensor-side periphery of the primer piece 11, and is formed in the stepped notch 32. The burrs 23 can be projected to support and fix the primer piece 11. As shown in FIG. 4, the surface of the welding burr 23 projecting into the stepped portion 32 in the sensor direction is used for fixing the primer piece 11, that is, friction welding of the partition wall 22, and for projecting the welding burr at the accommodation location of the mechanical sensor. By performing the operation while the jig 25 for regulating the shape is inserted, the protrusion shape is regulated. The sensor-side surface of the welding burr 23 is flush with the sensor-side surface of the primer piece 11. This jig 2
Reference numeral 5 has substantially the same shape as the mechanical sensor housed in the ignition means housing chamber. Thus, the detonator piece is welded to the burr 2
After fixing at 3, the primer 10 is housed and fixed in the recess 17 of the primer piece 11.

In the groove 31 of the primer piece shown in FIG.
In addition, a rotation preventing portion 26 for preventing rotation of the primer piece 11 in the housing 1 as shown in FIG. 5 can be formed in the stepped portion 32 shown in FIG. The rotation preventing portion 26 prevents the rotation of the primer piece 11 by cutting out a part of the groove 31 and the stepped portion 32 and projecting the welding burr 23 into the cutout portion. Can be.

FIG. 6 is a block diagram of the airbag device. The gas generator of the present invention and an airbag (bag) 100 are shown.
And a module case 101. The gas discharged from the gas discharge port 4 of the gas generator is
00, the airbag 100 breaks the module cover 102 and bulges out, forming a cushion between the steering wheel 103 and the occupant for absorbing impact.

As the gas generator, the gas generator described with reference to FIGS.

The module case 101 is made of, for example, polyurethane and includes a module cover 102. In this module case 101, the airbag 10
The gas generator and the gas generator are housed in the pad module, and attached to the steering wheel 103 of the automobile.

The airbag 100 is formed of nylon (eg, nylon 66), polyester, or the like.
The bag mouth surrounds the gas outlet 4 of the gas generator, and is fixed to a flange portion of the gas generator in a folded state.

[0035]

The gas generator for an air bag according to the present invention is configured as described above, and secures a space for welding burrs generated by friction welding and eliminates the step of removing the welding burrs. As a result, gas generation for airbags can be achieved by miniaturizing the entire structure, without being adversely affected by welding burr shavings, and by effectively using the projections of the welding burr to fix a primer mounting structure such as a primer piece. Vessel can be provided.

[Brief description of the drawings]

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

FIG. 2 is an enlarged longitudinal sectional view of a main part showing a fixed state of a primer piece.

FIG. 3 is an enlarged longitudinal sectional view of a main part showing a fixed state of a primer piece according to another example.

FIG. 4 is an enlarged sectional view of a main part showing a state of regulation of welding burrs.

FIG. 5 is a plan view of a primer piece showing a rotation preventing unit.

FIG. 6 is a configuration diagram of an airbag device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Housing 2 Diffuser shell 3 Closure shell 5 Gap part 6 Mechanical sensor 10 Detonator 11 Detonator piece 12 Transfer agent 13 Gas generating agent 17 Depression 18 Shooting pin 23 Welding burr 25 Jig 26 Rotation prevention part 31 Groove 32 Stepped part

Claims (10)

[Claims] An ignition means comprising a mechanical sensor for sensing a shock and firing a firing pin, a detonator pierced by the firing pin and ignited, and a transfer charge ignited and burned by the flame of the firing pin. In a mechanical ignition type gas generator, a primer mounting structure for accommodating and fixing a primer at a piercing point of a firing pin emitted from a sensor is brought into contact with a peripheral wall surface of the primer mounting structure and is friction-welded. A gas generator for an airbag, wherein the gas generator is fixed by welding burrs generated and generated by friction welding of members. 2. A contact with a peripheral wall surface of said primer mounting structure,
The member to be friction-welded is a partition that defines an ignition means housing chamber inside, and the primer mounting structure is fixed by welding burrs protruding toward the ignition means storage chamber during friction welding of the partition. The gas generator for an airbag according to claim 1, wherein 3. The welding burr is a welding burr protruding from a peripheral wall surface of the primer mounting structure and / or a sensor-side peripheral edge of the primer mounting structure. A gas generator for an airbag as described in the above. 4. A primer mounting structure is formed on a peripheral wall of the primer mounting structure in a circumferential direction thereof, and a welding burr is projected into the welding flash receiving part to fix the primer mounting structure. The gas generator for an airbag according to any one of claims 1 to 3, wherein: 5. The welding deburring accommodating portion is a groove formed in a circumferential direction of the peripheral wall of the structure for mounting a primer. The gas generator for an airbag according to claim 4, wherein the structure for fixing is fixed. 6. The welding deburring accommodating part is a stepped notch formed on the sensor-side periphery of the primer mounting structure, and the deflector mounting structure is provided with a welding burr protruding into the stepped notch. The gas generator for an airbag according to claim 4, wherein the gas generator is supported and fixed. 7. The sensor according to claim 6, wherein the surface of the welding burr protruding in the stepped portion in the sensor direction is regulated by a welding burr regulating member inserted into a housing of the mechanical sensor. A gas generator for an airbag as described in the above. 8. A rotation preventing portion formed in the welding burr accommodating portion to prevent rotation of the primer mounting structure by means of a projection of the welding burr. A gas generator for an airbag as described in the above. 9. A gas generator for an airbag according to claim 7, wherein said rotation preventing portion is formed by cutting out a part of a welding burr accommodating portion. 10. A gas generator for an airbag that generates gas by sensing an impact, an airbag that expands by introducing gas generated by the gas generator, and a module case that houses the airbag. Including
The airbag device, wherein the gas generator for an airbag is the gas generator for an airbag according to any one of claims 1 to 9.