JPH09142246A - Gas generating device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the leakage of the combustion gas of a gas generating agent perfectly, by providing a lid body having a hole, where a synthetic resin ball can't pass and a flame can pass even when the synthetic resin ball is pressed, at the outlet of the flame from the synthetic resin ball chamber. SOLUTION: A synthetic resin ball 1 is set in the movable condition, in a synthetic resin ball chamber 3 positioning at the middle part between a flame conduit 2 and a gas generating agent chamber 9. Holes are formed at the upper side and the lower side of the synthetic resin ball chamber 3, and the diameter of the hole at the flame conduit 2 side, that is the flame inlet 4, is smaller than that of the synthetic resin ball 1. To a lid 6 provided between the another gas generating agent chamber 9, a hole 5 where the synthetic resin ball 1 cannot pass, which is not sealed even when the synthetic resin ball 1 is pressed, is provided. Inside the gas generating agent chamber 9, a well-known gas generating agent 10 such as a smokless powder and a composite propellant is housed. By such a constitution, a leakage of the combustion gas of the gas generating agent can be prevented perfectly.

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. In addition, the use of the detonating wire made it possible to destroy the partition wall and ignite the gas generating agent, but on the contrary, since the combustion gas after ignition leaks from the detonating wire side, it is necessary to store more gas generating agent than necessary. The problem is that it must be done. So instead of the detonator,
It is possible to use a safer flame conduit, but since this flame conduit is also hollow, the combustion gas in the gas generator leaks through the flame conduit, lowering the gas pressure and generating higher pressure. In the case of a gas generator, there is a risk of blowing out the flame conduit itself.

Further, JP-A-5-302799 discloses a gas generator which prevents a combustion gas of a gas generating agent from flowing back to the firing pin hole of a stub detonator with a hard ball. However, since this device uses a hard ball, if a very small gap is created when the hard ball comes into contact with the entrance of the firing pin hole and tries to seal the gas, the contact portion is melted by the combustion gas of high temperature and high pressure. There is a problem that the combustion gas may flow backward due to the loss and expansion of the gap.

[0006]

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

[0007]

The present invention has a synthetic resin ball chamber (3) in which a synthetic resin ball (1) is movably incorporated and through which a flame from a flame conduit (2) passes. The size of the flame inlet (4) to the synthetic resin ball chamber is smaller than the diameter of the synthetic resin ball chamber, and the synthetic resin ball does not pass through the flame outlet from the synthetic resin ball chamber. The present invention relates to a gas generator having a structure in which a lid (6) having a hole (5) through which a flame can pass even when a synthetic resin ball is pressed is installed.

[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 synthetic resin spheres (1) used in the present invention are, for example, polytetrafluoroethylene resin spheres, silicon resin spheres, polyamide resin spheres, polyimide resin spheres, polycarbonate resin spheres, polyphenylene ether resin spheres, polyphenylene sulfide resin spheres, and the like. The material is not particularly limited as long as it can withstand high temperature and high pressure. Among them, polytetrafluoroethylene resin spheres are particularly preferable in terms of physical properties. The size of the synthetic resin sphere needs to be slightly larger than the size of the flame inlet (4) and the diameter is usually 2-4 mm.

The synthetic resin ball (1) is movably installed in a synthetic resin ball chamber (3) located between the flame conduit (2) and the gas generating agent chamber (9). There is a hole at the top and bottom of the synthetic resin ball chamber, the hole on the upper side, that is, the flame conduit side,
That is, the flame inlet (4) must be smaller in diameter than the synthetic resin ball.

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 the synthetic resin balls collide with each other due to the ignition of the 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 synthetic resin balls do not pass therethrough and the synthetic resin balls are not pressed and sealed. .

A gas generating agent chamber (9) is provided below the synthetic resin ball chamber (3), and a known gas generating agent (10) such as smokeless explosive or composite propellant is stored inside. An igniting agent such as boron nitrate may be added to the gas generating agent. If deterioration of the gas generant due to moisture absorption is feared, install a moisture-proof thin film such as an aluminum foil (8) and a gasket (7) such as unvulcanized butyl rubber above the gas generant chamber. There is also. The position may be on either the upper or lower side with respect to the synthetic resin ball.

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 synthetic resin ball chamber holding the synthetic resin balls of the gas generator. The flame ruptures the scaffold installed above or below the synthetic resin ball, passes through the synthetic resin ball side, passes through the hole at the bottom of the synthetic resin ball chamber, and burns the gas generating agent.

Due to the high pressure generated in the gas generating agent chamber by the combustion of the gas generating agent, the synthetic resin balls move upward and are pressed against the holes of the flame inlet (4) in the upper part of the synthetic resin ball chamber 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. Below the aluminum foil is a concave aluminum lid (6) forming a synthetic resin ball chamber (3), in which a 3.17 mm diameter Teflon sphere (1) is held. [Teflon is a product name of polytetrafluoroethylene resin manufactured by Ei DuPont. ] In the center of the lid, as shown in FIG. 2, two holes (5) through which the flame from the flame conduit can pass even if the Teflon ball is pressed downward are opened, and the gas generating agent made of aluminum immediately below is opened. It leads to a gas generant chamber (9) consisting of a container (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. After the measurement, the gas generator was disassembled and the adapter part was examined. As a result, it was found that the Teflon sphere was partially stuck in the hole of the adapter and fixed. When this was taken out and examined for a Teflon sphere, it had a shape as shown in FIG.

Embodiment 2 A gas generator according to Embodiment 2 of the present invention has the structure shown in FIG. Teflon spheres having the same diameter as in Example 1 were used as the synthetic resin spheres. Further, it is different from Example 1 in that the synthetic resin balls are held in the adapter and the aluminum moisture-proof foil is installed below. 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.

When 100 gas generators were prepared and operated by igniting a nonel tube, and the combustion pressure was measured in the same manner as in Example 1, all 100 showed a pressure of 50 MPa or more. .

Comparative Example 1 The pressure of combustion gas was measured by operating the same gas generator as in Example 1 except that synthetic resin balls were not used. 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.

Comparative Example 2 100 gas generators exactly the same as in Example 2 were prepared except that the synthetic resin balls were changed to steel balls, and the same operation as in Example 1 was performed to measure the pressure of the combustion gas. It was The result is 10
A decrease in pressure was observed at 40 MPa and 43 MPa in 2 of 0 pieces. The flame slightly blew toward the Nonel tube, and the Nonel tube was slightly damaged.

[0027]

Since the present invention is configured as described above, it has the following effects. INDUSTRIAL APPLICABILITY The present invention makes it possible to completely prevent the combustion gas from being jetted to the flame conduit side, and provides 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.

[0028]

[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.

[0029]

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

[0030]

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

[0031]

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

[0032]

FIG. 5 is an enlarged cross-sectional view of the Teflon spheres recovered after operating the gas generator shown in Example 1 of the present invention.

[0033]

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 synthetic resin ball 2 flame conduit 3 synthetic resin 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 (2)

[Claims] 1. A gas generator having a structure in which a gas generating agent is ignited by a flame conduit, wherein a synthetic resin ball (1) is movably incorporated and a flame from a flame conduit (2) passes through. It has a resin ball chamber (3), the size of the flame inlet (4) to the synthetic resin ball chamber is smaller than the diameter of the synthetic resin ball chamber, and the flame outlet from the synthetic resin ball chamber is A lid (6) having a hole (5) through which the synthetic resin ball does not pass and a flame can pass even if the synthetic resin ball is pressed
A gas generator having a structure in which is installed. 2. The gas generator according to claim 1, wherein the synthetic resin sphere is a polytetrafluoroethylene resin sphere.