JPH084367Y2 - Gas generator for airbag deployment - Google Patents

Description

[Detailed Description of the Invention] [Industrial field of application] The present invention is an airbag used to deploy airbags for collision safety devices such as airbags, life bags, rubber boats and escape chutes by combustion gas. The present invention relates to a deployment gas generator, and more particularly, to a structure for attaching an igniter to a lid member and a structure for a caulking portion of the igniter.

[Conventional technology]

Conventionally, in a passenger car, a collision safety device for protecting a driver from a shock at the time of a collision is, for example, an airbag having a volume of 60 liters and an airbag deployment gas for deploying the airbag with gas. It is composed of a generator and, at the time of a collision of a passenger vehicle, ignites and combusts a gas generant consisting of explosives or a similar composition filled in a gas generator for expanding an airbag, and generates an air bag by the generated gas. It deploys instantly to protect the driver from collisions and prevent serious injury to the driver.

FIG. 5 shows a conventional gas generator for expanding an air bag disclosed in Japanese Patent Application Laid-Open No. 2-155857, in which reference numeral 11 indicates combustion in which a plurality of gas generating agents 13 are contained in a stacked state. Shows the room.

The gas generating agent 13 has an annular plate shape with a through hole 15 formed in the center thereof, and an igniting agent 17 is contained in the through hole 15.

These gas generating agents 13 are housed in a sealed container 19, and a recess 21 is formed in the center of the sealed container 19 so as to be depressed toward the through hole 15 side of the gas generating agent 13.

An igniter 23 for burning the gas generating agent 13 is arranged in the recess 21.

A combustion chamber filter 25 is arranged along the inner circumference of the combustion chamber 11, and a gas that surrounds the combustion chamber 11 and has passed through the combustion chamber filter 25 flows from an orifice 26 into a charging chamber 27.
Are arranged in a ring.

A filling chamber filter including an upper filter 29 and a gas filtering filter 31 is housed in the filling chamber 27.

Further, in the charging chamber 27, a gas outlet 33 is formed to let the gas that has passed through the gas filtration filter 31 flow out to the airbag.

In such an air bag deployment gas generator, when electricity is applied to the igniter 23, the explosive in the igniter 23 burns to ignite the igniting charge 17, and the combustion causes the gas generating agent to burn.
13 burns, the gas of the gas generating agent 13 passes through a combustion chamber filter 19 arranged along the inner circumference of the combustion chamber 11, and fills the charging chamber.
After flowing into 27, the upper filter 29 and the gas filter
It is purified by 31 and flows into the airbag through the gas outlet 33, and the airbag is sufficiently expanded in a short time of, for example, about 0.04 seconds.

[Problems to be solved by the device]

However, such a conventional air bag expansion gas generator has a problem that the pressure in the combustion chamber 11 rises when the atmospheric temperature of the device rises due to, for example, a fire of the vehicle.

Therefore, conventionally, when the atmospheric temperature of the device rises, a gas generating device for airbag deployment has been developed, which is provided with a safety device for avoiding an increase in the pressure in the combustion chamber 11,
In this case, since the safety device is separately provided, the mechanism is complicated and the manufacturing cost is increased.

The present invention solves the above problems, and an object of the present invention is to provide a gas generator for airbag deployment that can reliably avoid an increase in pressure in the combustion chamber with a very simple configuration. And

[Means for solving the problem]

The gas generator for airbag deployment according to claim 1 stores a gas generating agent in a tubular member having a bottomed tubular shape, and seals an opening of the tubular member with a lid member to form a combustion chamber. Then, in an air bag expansion gas generator in which an igniter is inserted and fixed in a through hole formed in the center of the lid member, the igniter is press-fitted into the lid member and fixed by welding from the outside. The strength of the press-fitted weld is lower than the breaking pressure of the combustion chamber and higher than the pressure of the combustion chamber during operation.

The gas generator for airbag deployment according to claim 2 stores a gas generating agent in a tubular member having a bottomed tubular shape, and seals an opening of the tubular member with a lid member to form a combustion chamber. Then, in the gas generator for airbag deployment in which the holder of the igniter is inserted and fixed in the through hole formed in the center of the lid member, the holder of the igniter is caulked and fixed to the harness supporter of the igniter. The strength of the caulked portion is lower than the breaking pressure of the combustion chamber and higher than the combustion chamber pressure during operation.

[Action]

In the air bag expansion gas generator of claim 1, the ambient temperature of the combustion chamber becomes high, and the pressure in the combustion chamber becomes a set pressure that is higher than the combustion chamber pressure during operation and lower than the destruction pressure of the combustion chamber. Then, the igniter is pressed outward by the internal pressure of the combustion chamber, and the lid member bulges outward in a convex shape, and the press-fit welded portion of the igniter to the lid member breaks the combustion chamber. It is destroyed at a pressure lower than the pressure and an increase in the combustion chamber pressure is avoided.

In the air bag expansion gas generator of claim 2, the ambient temperature of the combustion chamber becomes high, and the pressure in the combustion chamber becomes a set pressure that is higher than the combustion chamber pressure at the time of operation and lower than the destruction pressure of the combustion chamber. Then, the caulking part of the igniter holder is pushed outward by the internal pressure in the combustion chamber through the harness supporter and opens, and the caulking part is broken at a pressure lower than the breaking pressure of the combustion chamber, Increased pressure is avoided.

〔Example〕

Hereinafter, the details of the present invention will be described with reference to the embodiments shown in the drawings.

FIG. 1 shows an essential part of an embodiment of a gas generator for deploying an airbag of the present invention. In the figure, reference numeral 41 indicates
For example, a tubular member having a bottomed tubular shape made of stainless steel and containing a gas generating agent is shown.

The opening of the tubular member 41 is sealed by fixing a lid member 43 made of, for example, stainless steel by welding 45, and a combustion chamber 47 is formed inside.

A through hole 49 is formed in the center of the lid member 43, and an igniter 51 is inserted into the through hole 49.
Is welded and fixed to the lid member 43 in a press-fitted state.

FIG. 2 shows the details of the press-fitting welded portion 53 of FIG. 1. In this embodiment, annular protrusions 55, 57 are formed on the outer periphery of the igniter 51 at predetermined intervals. By press-fitting the lower protruding portion 55 into the through hole 49 of the lid member 43, the inner peripheral edge of the through hole 49 of the lid member 43 is positioned between the protruding portions 55 and 57.

The outer periphery of the igniter 51 is welded 59 to the lid member 43 on the outer side of the lid member 43.

Further, in this embodiment, the press-fit welding strength of the press-fit welding portion 53 is lower than the breaking pressure of the combustion chamber 47 and is higher than the pressure of the combustion chamber 47 during operation, and the press-fit welding portion 53 is press-fit. Is set to destroy.

That is, for example, as shown in FIG. 3, when the pressure in the combustion chamber 47 is plotted on the horizontal axis and the number of samples is plotted on the vertical axis, when the device is operating, that is, when the ambient temperature of the combustion chamber 47 is 80 ° C. The pressure of the combustion chamber 47 during the combustion of the gas generating agent is about 162 atm.

 On the other hand, the breaking pressure of the combustion chamber 47 is about 589 atm.

Therefore, in this embodiment, the press-fit welding strength of the press-fit welding portion 53 is set so that the press-fit welding portion 53 is broken at a pressure of, for example, about 350 atm.

Thus, in the air bag deployment gas generator configured as described above, the igniter 51 is press-fitted into the lid member 43,
While fixing by welding from the outside, the strength of the press-fit welding portion 53 is lower than the burst pressure of the combustion chamber 47 and higher than the pressure of the combustion chamber 47 during operation, so that the ambient temperature of the combustion chamber 47 becomes high, When the pressure in the chamber 47 becomes higher than the pressure of the combustion chamber 47 during operation and becomes lower than the destructive pressure of the combustion chamber 47, the igniter 51 moves outward due to the internal pressure in the combustion chamber 47. Pressed, and as shown by the chain double-dashed line in FIG.
The lid member 43 bulges outward in a convex shape, and the press-fit welding portion 53 of the igniter 51 to the lid member 43 is broken at a pressure lower than the breaking pressure of the combustion chamber 47, and the rise of the pressure of the combustion chamber 47 is avoided. Therefore, it is possible to reliably avoid the increase in the pressure in the combustion chamber 47 with a very simple configuration.

FIG. 4 shows an igniter of another embodiment of the gas generator for deploying an air bag of the present invention.
Shows a cylindrical metal holder.

An ignition agent 63 and a transfer agent 65 are arranged in the holder 52.

A harness supporter 67 is inserted from one end into one opening of the holder 52.

A harness 69 is planted in the harness supporter 67, and the harness 69 is electrically connected via a lead terminal 71 to a heater 73 arranged in contact with the ignition agent 63.

And in this embodiment, the holder 52 of the igniter 51,
By bending the caulking portion 75 at the upper end, the caulking is fixed to the harness supporter 67.

The caulking strength of the caulking portion 75 is set to be lower than the breaking pressure of the combustion chamber 47 and higher than the pressure of the combustion chamber 47 during operation, for example, 350 atmospheres, so that the caulking portion 75 breaks. ing.

Therefore, in the air bag deployment gas generator configured as described above, the holder 52 of the igniter 51 is replaced by the igniter 51.
In addition to crimping and fixing to the harness supporter 67 of, the strength of the crimping portion 75 is lower than the breaking pressure of the combustion chamber 47, and
Since the pressure in the combustion chamber 47 during operation is set to be higher, the ambient temperature in the combustion chamber 47 becomes higher, the pressure in the combustion chamber 47 is higher than the pressure in the combustion chamber 47 during operation, and the breaking pressure of the combustion chamber 47 is high. When the set pressure becomes smaller, the caulking portion 75 of the holder 52 of the igniter 51 is pushed outward by the inner pressure of the combustion chamber 47 through the harness supporter 67, and two points are shown in FIG. As shown by the chain line, the caulking part 75 is broken at a pressure lower than the breaking pressure of the combustion chamber 47, and the rise of the pressure of the combustion chamber 47 is avoided. With a simple configuration, it is possible to avoid it without fail.

In addition, in the above-described embodiment, the example in which the tubular member 41 and the lid member 43 are formed of stainless has been described, but the present invention is not limited to such an embodiment, and is formed of, for example, aluminum or the like. Of course, it is okay.

Further, in the embodiment described above, the example in which the breaking pressure of the press-fitting weld portion 53 is set to about 350 atm, the present invention is not limited to such an embodiment, the plate thickness,
Of course, the optimum value can be set by changing the material.

[Effect of device]

As described above, in the air bag expansion gas generator of claim 1, the igniter is press-fitted into the lid member to be welded and fixed from the outside, and the strength of the press-fitted welded portion is determined from the burst pressure of the combustion chamber. Since the pressure is low and higher than the pressure in the combustion chamber during operation, the ambient temperature in the combustion chamber increases, and the pressure in the combustion chamber is higher than the pressure in the combustion chamber during operation and lower than the burst pressure in the combustion chamber. When the set pressure is reached, the igniter is pressed outward by the internal pressure of the combustion chamber, and the lid member bulges outward in a convex shape. Since the destruction is performed at a pressure lower than the destruction pressure and the increase in the combustion chamber pressure is avoided, there is an advantage that the increase in the pressure in the combustion chamber can be reliably avoided with a very simple configuration.

In the gas generator for airbag deployment according to claim 2, the holder of the igniter is fixed to the harness supporter of the igniter by caulking, and the strength of the caulking portion is lower than the breaking pressure of the combustion chamber and the combustion during operation is performed. Since it is set higher than the chamber pressure, the ambient temperature in the combustion chamber rises, and when the pressure in the combustion chamber reaches the set pressure that is higher than the combustion chamber pressure during operation and lower than the destruction pressure of the combustion chamber, the igniter The caulking part of the holder is pushed outward by the internal pressure of the combustion chamber via the harness supporter and opens, and the caulking part is destroyed at a pressure lower than the destructive pressure of the combustion chamber, and the rise of the combustion chamber pressure is avoided. Therefore, there is an advantage that an increase in the pressure in the combustion chamber can be reliably avoided with a very simple configuration.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view showing the main part of an embodiment of a gas generator for deploying an air bag of the present invention. FIG. 2 is a sectional view showing details of the press-fitting welded portion of FIG. FIG. 3 is a graph showing the operating pressure and the breaking pressure of the combustion chamber of FIG. FIG. 4 is a sectional view showing details of the igniter of FIG. FIG. 5 is a vertical cross-sectional view showing a conventional air bag deployment gas generator. [Explanation of symbols for main parts] 41 …… Cylindrical member 43 …… Lid member 47 …… Combustion chamber 49 …… Through hole 51 …… Ignition device 52 …… Holder 53 …… Press-fit weld. 67 …… Harness supporter 75 …… Crimping part.

Continuation of the front page (72) Koichi Uechi, Koichi Uechi, 1-4-1, Chuo, Wako-shi, Saitama, Honda R & D Co., Ltd. (56) References JP-A-2-258451 (JP, A) JP-A-3 -92449 (JP, A)

Claims (2)

[Scope of utility model registration request] 1. A bottomed tubular tubular member containing a gas generating agent, the opening of the tubular member being closed by a lid member to form a combustion chamber, and the combustion chamber is formed at the center of the lid member. In an air bag expansion gas generator in which an igniter is inserted and fixed in a formed through hole, the igniter is press-fitted into the lid member and welded and fixed from the outside, and the strength of the press-fitted welded portion is increased. A gas generator for expanding an air bag, which is lower than a breaking pressure of the combustion chamber and higher than a combustion chamber pressure during operation. 2. A gas generating agent is contained in a cylindrical member having a bottomed cylindrical shape, and an opening of the cylindrical member is closed by a lid member to form a combustion chamber, and the combustion chamber is formed at the center of the lid member. In an air bag deployment gas generator in which a holder of an igniter is inserted and fixed to a through hole formed, the holder of the igniter is fixed to the harness supporter of the igniter by caulking, and the strength of the caulking portion is A gas generator for airbag deployment, which is lower than the burst pressure of the combustion chamber and higher than the combustion chamber pressure during operation.