JPH09136602A - Gas generator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a simple and safe gas generator with a mechanism for preventing combustion gas leakage of a gas generating agent in a gas generator suited to use of a flame conduit. SOLUTION: This gas generator is a gas generator having such as a structure as to ignite a gas generating agent with a flame conduit, houses a hard ball 1 so as to move freely, and a hard ball chamber 3 for passing flames from a flame conduit 2. In this gas generator, the size of a flame inlet 4 for the hard ball chamber 3 is smaller than the diameter of the hard ball 1, and a cover 6 having such a hole 5 as the hard ball 1 cannot pass through, but flames can pass through even if the hard ball is pressed against.

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 a seat belt pretensioner, an airbag, etc., which is separated from an ignition part and a gas generation part, and more particularly to a plurality of gases in which ignition of one ignition part is isolated. The present invention relates to a gas generating device that uses a flame conduit for guiding to a generating portion.

[0002]

2. Description of the Related Art Conventionally, various seat belt pretensioners or airbags having a gas generator built therein have been developed to protect an occupant of a vehicle from the impact of a collision. These devices incorporate electronic, electrical or mechanical collision sensors, electrical or mechanical igniters and gas generators.

By the way, in recent years, mounting these protective devices on all seats has been studied, and development of a sensor for a rear seat has started. However, due to the structural limitation of automobiles, the drawback of delaying the detection of impact in the back seat cannot be improved. For this reason, an ignition device has been developed which is described in Japanese Utility Model Publication No. 5-72608 and which is characterized by the use of a detonating wire.
This device uses a sensor installed in the front part to ignite the detonating wire in the event of a collision, and by detonating one end of the detonating wire, a detonation wave propagates in the detonating wire and It is a mechanism that ignites multiple gas generators connected to the end.

However, this technique has a serious problem per se in using the detonating wire. That is, the detonating wire itself
It is a powerful explosive and gives a strong impact not only on both ends but also on the entire circumference. Therefore, special protection measures for occupants are required for installation in the vehicle.

Further, it has become possible to ignite the gas generating agent by breaking the partition wall by using the detonating wire, but on the contrary, since the combustion gas after ignition leaks from the detonating wire side, an excessive amount of gas generating agent is required. The problem is that it must be stored. Therefore, it is possible to use a safer flame conduit instead of the detonator, but since this flame conduit is also hollow, the combustion gas in the gas generator leaks through the flame conduit and the gas pressure drops. In addition, there is a risk of blowing out the flame conduit itself in the case of a gas generator that generates higher pressure.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to provide a gas generator suitable for use in a flame conduit, which is a simple and safe gas generator provided with a mechanism for preventing leakage of combustion gas of a gas generating agent. Is to provide.

[0007]

The present invention provides a hard sphere (1)
Has a hard ball chamber (3) through which the flame from the flame conduit (2) passes, and the size of the flame inlet (4) to the hard ball chamber is the diameter of the hard ball. A lid (6) having a smaller shape and having a hole (5) through which the flame does not pass and the flame can pass even when the hard ball is pressed is installed at the flame outlet from the hard ball chamber. The present invention relates to a gas generator having the above structure.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be specifically described below with reference to the drawings. The flame conduit (2) used in the present invention is excellent as a means for transmitting ignition energy from an ignition means installed at a remote place to a gas generating agent incorporated in a plurality of gas generators in a vehicle.

The term "flame conduit" as used herein specifically means, for example, a squib or gas conduit. The former is a hollow plastic tube with a small amount of powdered explosives applied to the inner surface.
The latter consists of a plastic or metal tube containing an explosive gas. In both cases, when one end is ignited, the flame propagates through the tube at 2000 to 2500 m / sec, and the flame ejected from the end can ignite the gas generating agent.

The flame conduit may be, for example, a nonel tube (registered trademark) manufactured by Nitro Nobel Co., or a part of a Har-Cudet system (registered trademark) manufactured by Har-Cudet.

The former Nonel tube is made of a resin tube having an outer diameter of 3 mm and an inner diameter of 1 mm, and HMX of explosive is formed on the inner surface.
Powder and aluminum powder are applied. This nonel tube is ignited by, for example, a detonator for a gun, and the flame propagates in the tube at a speed of about 2000 m / sec and can ignite the explosive at the end.

The latter Herculdet system explodes an explosive gas (a mixed gas of oxygen and fuel) sealed in a resin tube, propagating a flame at a speed of about 2500 m / sec, and It can ignite gunpowder.

In both cases, the flame propagates only in the tube,
It does not break through the tube on the way. Therefore, if you connect the front end to the ignition part and the rear end to the gas generation part in a sealed manner,
These flames never blow out into the car on the way.

The hard sphere (1) used in the present invention is, for example, a metal sphere such as a steel sphere, a copper sphere, or a brass sphere, or a ceramic sphere, as long as it is a material that does not deform even when pressed against a hard object under high pressure. There is no limit. Its size should be slightly larger than the size of the flame inlet (4) and the diameter is usually 2-4
mm.

The hard ball (1) is movably installed in a hard ball chamber (3) located between the flame conduit (2) and the gas generating agent chamber (9). There are holes at the top and bottom of the hard ball chamber, and the hole to the upper side, that is, the flame conduit side, that is, the flame inlet (4) must have a diameter smaller than that of the hard ball, and the hole must be made of a hard material such as metal. If so, it is preferable that both the hard spheres are perfect circles. However, when an elastic body such as an O-ring or packing is installed in the portion of the hole where the hard ball hits, the hole does not have to be a perfect circle.

The lid (6) provided between the other gas generating agent chamber and the gas generating agent chamber must have such strength that it will not be destroyed even if a hard ball collides due to the ignition of a flame conduit. The holes (5) provided in the lid may be plural as shown in FIGS. 2 and 4, and may have any shape as long as the hard balls do not pass therethrough and they are not sealed even when the hard balls are pressed.

A gas generating agent chamber (9) is provided below the hard spherical chamber (3), and a known gas generating agent (10) such as smokeless explosives or composite propellants is stored inside. An igniting agent such as boron nitrate may be added to the gas generating agent.
If there is a concern that the gas generating agent may deteriorate due to moisture absorption,
A thin film having moisture resistance such as an aluminum foil (8) and a gasket (7) such as unvulcanized butyl rubber may be installed above the gas generating agent chamber. The position may be on either the upper side or the lower side of the hard sphere.

The function of this device will be described in detail including the auxiliary parts. For example, in the case of being installed in an automobile, when the automobile collides, the collision is sensed and the ignition means immediately ignites. Due to this ignition, the flame conduit is ignited, and the flame is sent into the hard ball chamber holding the hard balls of the gas generator. The flame ruptures the sclera film installed above or below the hard sphere, passes through the side of the hard sphere, passes through the hole at the bottom of the hard sphere, and burns the gas generant.

Due to the high pressure generated in the gas generant chamber by the combustion of the gas generant, the hard spheres move upward and are pressed against the perfect circular holes in the upper part of the hard sphere to form an embolus. For this reason, the gas in the gas generating agent chamber accumulates without leaking, and eventually the sealing plate (13) at the bottom of the gas generating agent chamber is ruptured to fill the connected cylinder or bag, and the seat belt pretensioner, airbag, etc. To operate effectively.

[0020]

Next, embodiments of the present invention will be described with reference to the drawings. Example 1 The gas generator of this example has a structure shown in FIG. (2) in the figure is a nonel tube (registered trademark) which is a kind of flame conduit, and an explosive or the like is applied to the inner surface of the tube. The flame conduit can be ignited by an electrical igniter such as a squib or mechanical means such as a stub detonator.
(12) is an aluminum adapter that connects the flame conduit and the gas generator. Insert and fix the flame conduit from above in FIG. Adapter is 2mm in diameter from top to bottom
A perfect circular flame inlet (4) having an inner diameter of

Below the adapter, there is an unvulcanized butyl rubber gasket (7), which has a moisture-proof function, and an aluminum foil (8) having a thickness of 10 μm. Under the aluminum foil is a concave aluminum lid (6) that forms a hard bulb chamber (3).
And a steel ball for bearing (1) having a diameter of 3.17 mm is held therein. As shown in FIG. 2, two holes (5) through which the flame from the flame conduit can pass are opened in the center of the lid even if the steel ball is pressed down, and the gas generating agent container made of aluminum immediately below is opened. It leads to a gas generant chamber (9) consisting of (11). As the gas generating agent (10), 1 g of smokeless gunpowder and 0.1 g of boron salt stone igniter were used.

This gas generator was operated by igniting a nonel tube, and the combustion gas blown out from the bottom of the gas generating agent chamber was introduced into a closed space of 10 cm ³ . When the combustion pressure was measured, it showed a pressure of 51 MPa.

Embodiment 2 A gas generator according to Embodiment 2 of the present invention has the structure shown in FIG. Brass balls having the same diameter as in Example 1 were used as the hard balls. In addition, Example 1 in that the hard sphere is held in the adapter and the aluminum moisture-proof foil is installed below.
And different. A disk made of aluminum provided with eight small holes as shown in FIG. 4 was used as a partition lid with the gas generating agent chamber. As the gas generating agent, 1 g of smokeless explosive and igniting boron salt stone were used.

The gas generator was operated by igniting a nonel tube, and the combustion pressure was measured in the same manner as in Example 1. The pressure was 50 MPa.

Comparative Example 1 The same gas generator as in Example 1 was operated except that hard balls were not used, and the pressure of combustion gas was measured. As a result, the pressure was significantly reduced at 31 MPa. The flame blew violently toward the Nonel tube, and the Nonel tube was partially damaged.

[0026]

Since the present invention is configured as described above, it has the following effects. INDUSTRIAL APPLICABILITY According to the present invention, it is possible to prevent the combustion gas from being ejected to the flame conduit side, and to provide a gas generator that is safe and can efficiently use a gas generating agent. Also, since the structure is simple, it has good workability and is suitable for mass production. Further, when connected to a plurality of gas generators to measure the effective use of the flame of the flame conduit, it can be preferably applied not only for a frontal collision but also for a side collision or a rear seat airbag installed at a distant place.

[0027]

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a gas generation device according to a first embodiment of the present invention.

[0028]

FIG. 2 is a top view of a flame outlet lid used in Example 1 of the present invention.

[0029]

FIG. 3 is a cross-sectional view of a gas generating device according to a second embodiment of the present invention.

[0030]

FIG. 4 is a top view of a flame outlet lid used in Example 2 of the present invention.

[0031]

[Explanation of symbols]

 1 Hard Ball 2 Flame Conduit 3 Hard Ball Chamber 4 Flame Inlet 5 Hole 6 Lid 7 Gasket 8 Aluminum Foil 9 Gas Generating Agent Chamber 10 Gas Generating Agent 11 Gas Generating Agent Container 12 Adapter 13 Sealing Plate

Claims (1)

[Claims] 1. A gas generator having a structure in which a gas generating agent is ignited by a flame conduit, the hard sphere (1) being movably built in, and a flame from the flame conduit (2) passing therethrough. The chamber has a chamber (3), the size of the flame inlet (4) to the hard ball chamber is smaller than the diameter of the hard ball, and the hard ball is at the outlet of the flame from the hard ball chamber. A gas generator having a structure in which a lid (6) having a hole (5) through which a flame can pass even if a hard ball is pressed against the gas generator is installed.