JPH0725308A - Gas generator - Google Patents

Abstract

PURPOSE:To improve the reliability of ignition and prevent wrong explosion by energizing an ignition pin, flying being triggered by an inertia body moving upon detecting the deceleration of a vehicle, by spring force, igniting ignition chemical by supplying voltage from a piezoelectric element in association with the collision of the ignition pin, and making static electricity escape from an ignition means by a electrification preventing means. CONSTITUTION:Upon the collision of a vehicle, an inertia body B moves in a direction 43 and presses the tip part of a trigger lever 42 to rotate it, and the hook part 36b of an ignition pin 36 comes off a rotor 42a, so that the ignition pin 36 flys in a direction 44 by the energizing force of a compression spring 27 and collides with a piezoelectric element 30. Piezoelectricity is thereby generated to the piezoelectric element 30, and an electric discharge plug 34 discharges in a space to a center disc 19, thereby igniting ignition chemical 17. The ignition pin 36 thus ignites the ignition chemical 17 positively by the compression spring 27. Also, since a resistance 35 is provided between the electric discharge plug 34 and earth, static electricity escapes through the resistance 35 so as to prevent electrification.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas generator used by being incorporated in an air bag safety device of an automobile, and more particularly to improvement of an ignition part.

[0002]

2. Description of the Related Art A specific example of a gas generator used in a conventional airbag device will be described with reference to FIG. FIG. 2 is a vertical sectional view of the gas generator. In FIG. 2, the gas generator 1 is a so-called collective mounting type. Gas generator 1 is a cylindrical container 2
The upper container 3 and the lower container 4 are integrated by friction welding 5 or the like. The inside of the cylindrical container 2 is divided into an outer peripheral portion 23 and a central portion 24 by an inner wall 6, and the gas generating agent 12 and the gas filter 1 are provided in each chamber partitioned by the partition wall 7 in the outer peripheral portion 23.
3, 14, and 15 are arranged. In the central portion 24, the transfer charge 16 housed in a container 16a made of aluminum or the like is arranged above, the center disk 19 is fitted and inserted below it, and is locked to the inner wall 6 by a mechanical engaging means 56. ing. The center disk 19 is provided with an ignition powder storage portion 19a communicating with the transfer powder storage portion, and the ignition powder storage portion 19a is loaded with the ignition powder 17 contained in a container 17a such as an aluminum foil. Center disk 1
The collision sensor 20 is fitted into the space below 9 from below and is fixed by a cap 21.

The ignition charge 17 is ignited by an impact friction ignition method, and a needle-shaped tip 26a is provided in the collision sensor 20 below the ignition charge 17 so that the ignition charge 17 is urged by a biasing force of a spring 27. Ignition pins 26 that collide are arranged. When the ignition pin 26 collides with the ignition charge 17, the needle-shaped tip 26a pierces the container 17a and ignites the ignition charge 17 with its impact energy and friction energy.

When the vehicle body collides, the collision sensor 20 detects the collision, the lock of the ignition pin 26 is released, and the ignition pin 26 collides with the ignition charge 17 by the urging force of the spring 27,
It is ignited by the impact frictional force. The transfer charge 16 is ignited by the flame. The hot air of the transfer charge 16 that has ignited enters the gas generating chamber 12a through the communication holes 8 provided in the inner wall 6, the gas generating agent 12 is gasified to generate a large amount of gas, and the gas is the partition wall 7 or the outer wall. The gas holes 9, 10, 22, 11 and the gas filters 13, 14,
It is supplied to an airbag (not shown) by sequentially passing through 15 as indicated by an arrow 25.

[0005]

The gas generator described above has the following problems because the ignition powder 17 is ignited by the impact friction ignition method. That is, (1) ignition powder 1
Since 7 is sensitive, there is a danger of accidental explosion in manufacturing. (2) The requirements for heat resistance and ignition sensitivity for the gas generator conflict with each other, and it is difficult to design the composition of the ignition agent to obtain the required ignition sensitivity while satisfying the required heat resistance. Not reliable enough.

The present invention has been made in view of the above problems of the prior art, and an object of the present invention is to provide a gas generator having improved ignition reliability.

[0007]

In order to solve the above-mentioned problems, a gas generator of the present invention is a gas generator activated by ignition of an igniting agent, and is urged by a spring force to decelerate a vehicle. An ignition pin that is triggered and fly by an inertial body that detects and moves, a piezoelectric element that generates a voltage by collision of the ignition pin, an ignition means that is supplied with the voltage from the piezoelectric element and ignites an ignition charge by discharge, An antistatic means for discharging static electricity from the ignition means is provided.

[0008]

According to the above construction, the collision of the ignition pin causes the piezoelectric element to generate a voltage, and this voltage is supplied to the ignition means and discharged to ignite the ignition charge. Here, the inertial body is the ignition pin. Just by triggering, the collision energy of the ignition pin is given by the spring force which is the biasing means, and is independent of the movement energy of the inertial body. Therefore, even in the limited space, by changing the spring force, it is possible to easily secure the collision energy required to reliably ignite the ignition powder. Further, since the antistatic means for discharging static electricity from the ignition means is provided, even if such a discharge portion is provided, it is possible to avoid the risk of erroneous explosion due to static electricity.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a sectional view of an ignition part of a gas generator of the present invention. In FIG. 1, parts having the same operations as those in FIG. 2 are designated by the same reference numerals, and the description thereof will be omitted.

First, the structure of the gas generator of the present invention will be described with reference to FIG. 1 is different from FIG. 2 in that instead of the impact friction ignition method of FIG. 2, an electric ignition method is adopted, and the ignition charge 17 is ignited by a voltage caused by collision of the ignition pin 36 with the piezoelectric element 30. That is the point. That is,
The ignition powder 17 is loaded in the ignition powder storage portion 19a of the center disk 19 while being sealed with an aluminum stopper 32 at the upper portion and an insulating cap 33 made of resin at the lower portion.
At the center of the insulating cap 33, a discharge plug 34 having a sharp tip is provided as an ignition means so as to project into the ignition charge 17, and the other end thereof is projected to the outside as a terminal 34a. And
The piezoelectric element 30 is attached to the center disk 19 at a position slightly apart from the ignition agent storage portion 19a so as to contact with the center disk 19 and is attached downward, and the ignition pin 36 is disposed in the collision sensor 20 below the piezoelectric element 30. The tip 36a of the ignition pin 36 is flat so as to be optimal for electromotive force of the piezoelectric element 30. The ignition pin 36 has a compression spring 27.
Is urged in the direction of the arrow 44, and in this state, the hook portion 36b is hooked on the rotary body 42a of the trigger lever 42. The trigger lever 42 is rotatably provided around a position where the rotating body 42a is arranged, a bias pin 47 abuts on a rear end thereof, and is biased by a bias spring 46 in a direction of an arrow 44. A spherical inertial body B is housed and arranged in the cylinder 41 that opens in one direction above the tip of the trigger lever 42 in the drawing.

The piezoelectric element 30 is connected to the terminal 34a of the discharge plug 34 by a lead wire 31. In addition, as a means for preventing static electricity of the discharge plug 34 due to static electricity, the discharge plug 3
A resistor 35 having a high resistance value is connected between the terminal 34 a of No. 4 and the center disk 19.
Is grounded. A piezoelectric single crystal, piezoelectric ceramics, or the like is used for the piezoelectric element 30. In addition, the installation location of the piezoelectric element 30 can be arbitrarily selected, and the ignition powder storage unit 1 can be used as in the conventional case.
It may be a lower part of 9a.

Next, the operation of this gas generator will be described. When a vehicle collides, the inertial body B causes the arrow 4 to move due to the inertial force.
It moves in three directions and presses the tip of the trigger lever 42, the trigger lever 42 rotates and the hook portion 36b of the ignition pin 36 disengages from its rotating body 42a, and the ignition pin 36 is urged by the compression spring 27. It flies in the direction of arrow 44 and collides with the piezoelectric element 30. Due to this collision, a voltage proportional to the collision energy is generated in the piezoelectric element 30, the voltage causes the discharge plug 34 to discharge between itself and the center disk 19, and the ignition powder 17 is ignited. When the ignition charge 17 is ignited, the flame of the ignition charge 17 breaks the fragile portion provided in the aluminum plug 32 and reaches the transfer charge 16, which is ignited. The subsequent operation is the same as the conventional one.

As described above, since the inertial body B triggers the ignition pin 36 and the collision energy of the ignition pin 36 is applied by the urging force of the compression spring 27, the limited space in the collision sensor 20. Even in the inside, by changing the spring force, it is possible to easily secure the collision energy required to reliably ignite the ignition charge 17.
This is important because the present invention aims to improve the reliability of ignition.

The ignition system of the ignition agent of the gas generator originally has an impact friction system and an electric ignition system, and the impact friction system has a problem in ignition reliability as described in the prior art. Two ignition parts are provided to ensure redundancy. On the other hand, the electric ignition method does not have such a problem, and has a high reliability based on the actual results. In the gas generator described above, sparks are generated by the voltage of the piezoelectric element to ignite, but the ignition reliability is also high. Therefore, it is not necessary to secure redundancy, and it is possible to reduce costs. Also,
The application of the piezoelectric element to such spark generation has been widely used as a piezoelectric spark generator in a gas ignition device, a gas writer, and the like, and has a track record.

Further, if the discharge portion is provided in this way, there is a risk of accidental explosion due to discharge due to static electricity.
Since the resistor 35 is provided between the resistor and the ground, the static electricity is released to the ground through the resistor 35 and the charging is prevented.

The shape of the discharge plug 34 shown in FIG. 1 is not limited to that shown in the figure. A negative electrode (ground) may be provided near the discharge plug 34 to shorten the discharge distance.
The shape and the like of the discharge plug 34 are appropriately selected according to the voltage generated by the piezoelectric element 30 and the like.

[0017]

As described above, the gas generator of the present invention has the following features.
The ignition pin is energized by a spring force, is triggered by an inertial body that moves by detecting deceleration of the vehicle, and flies. Since the ignition means for igniting and the antistatic means for releasing static electricity from the ignition means are provided, it is possible to easily secure the collision energy necessary for surely igniting the ignition charge, in addition to the electric ignition method. For this reason,
It is possible to improve ignition reliability. And it is possible to prevent accidental explosion due to static electricity.

[Brief description of drawings]

FIG. 1 is a sectional view of an ignition part of a gas generator of the present invention.

FIG. 2 is a cross-sectional view of an ignition part of a conventional gas generator.

[Explanation of symbols]

 B Inertia 1 Gas generator 17 Ignition charge 27 Compression spring (spring) 30 Piezoelectric element 34 Discharge plug (ignition means) 35 Resistance (antistatic means) 36 Ignition pin

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kiyoshi Ichii 3903-39, Abundant Town, Himeji City, Hyogo Prefecture Nihon Kayaku Co., Ltd.

Claims (1)

[Claims] 1. A gas generator activated by ignition of an ignition charge, comprising an ignition pin that is energized by a spring force and is triggered by an inertial body that moves when detecting deceleration of a vehicle, and an ignition pin of the ignition pin. A piezoelectric element that generates a voltage by a collision, an ignition means that is supplied with the voltage from the piezoelectric element and ignites an igniting agent by discharge, and an antistatic means that discharges static electricity from the ignition means are provided. Gas generator.