JPH05246298A - Gas generator for air bag - Google Patents

Abstract

PURPOSE:To provide a gas generator for air bag in which an ignitor part is readily secured in a short time and having high drawing strength at the ignitor part. CONSTITUTION:In a gas generator formed by substantially coupling the receptacles 1, 2 of the gas generator with an ignitor part 5 serving as an ignition source, the receptacles of the gas generator are coupled with and secured to the ignitor part by means of retaining rings.

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 air bag which is activated when an accident such as a collision occurs in an automobile or the like to protect an occupant from an impact.

[0002]

2. Description of the Related Art A gas generator of an air bag device is mainly composed of an upper container, a lower container, a filter, a gas generating agent and an igniter section. Since the gas generator needs to deploy the bag in a short time, 30 to 100
It is necessary to generate about 150 to 200 liters of gas for each liter and passenger seat. Further, in order to complete the gas generation as described above in a short time, it is necessary to increase the burning rate of the gas generating agent in the generator, and therefore the gas generator is designed to withstand high pressure. . Therefore, the upper container and the lower container are firmly welded. However, since the temperature of the container itself becomes high during welding, it is preferable to perform the welding with the igniter part removed, and then attach the igniter part from the viewpoint of manufacturing. It is disclosed. Further, USP 4316874 describes a method of attaching a holder provided with a screw to an igniter and screwing it into a container after welding. Ignition to the igniter is usually done by electricity,
There are two types of ignition wires for energizing, a pin type for attaching a connector and a pigtail type that can be drawn around.

[0003]

If the igniter holder and the container are screwed together, a fitting failure and a looseness of the screw may occur depending on the precision of the screw, and the gas may come off during the combustion of the gas generating agent to leak gas. Yes, and it is difficult to confirm that the screws are completely tightened. In particular, when a lightweight metal such as aluminum is used as the base material, the screws are likely to be damaged and reliability is poor. Further, when the ignition wire is a pin type, it is not easy to align the position of the pin with a fixed position. In addition, in the push-in method, there is a problem in strength when trying to reduce the insertion force for safety of the igniter. An object of the present invention is to provide a gas generator that solves the above problems by using an igniter having a structure using concentric snap rings.

[0004]

That is, the present invention relates to a gas generator which is formed by substantially coupling an igniter portion which is an ignition source with a container of the gas generator, and the container of the gas generator and the igniter portion are connected to each other. The gas generator is characterized by being joined and fixed by a retaining ring.

[0005]

According to the present invention, the gas generator can be attached and fixed to the igniter simply by pushing in the igniter having a retaining ring structure fixing means. In addition, since the fixing means of the snap ring structure with a simple structure has been added to the igniter unit, by installing the igniter unit there is no looseness like the screw type fixing means, and it has the same function as a screw lock for disassembly prevention. The gas generator it has can be easily assembled.

[0006]

The present invention will be described below with reference to the drawings. Figure 1
An example of the pin type of the gas generator of the present invention,
It is composed of an upper container 1 , a lower container 2 , a gas generating agent 15, a filter 3 and an igniter section 5 . In the gas generator, a large number of beret-shaped or wafer-shaped gas generating agents 15 are housed in the combustion chamber 4 , and the combustion chamber 4 is partitioned by partition walls 16. The center of the combustion chamber 4 are arranged igniter unit 5 for burning the gas generating agent, also a filter 3 along the outer periphery of the combustion chamber 4 are arranged annularly. The igniter section 5 is composed of an igniter 10 and an igniter holder 13, and the igniter chamber 2
It is stored in 3. The igniter 10 contains a squib and an ignition powder (not shown).

In such a gas generator, when electricity is applied to the ignition pin 21 of the igniter 10, the igniting agent in the igniter 10 burns and passes through the connecting hole 14 formed in the igniter partition wall 22 to be attached. The heat particles or the hot gas of the explosive are transmitted to the combustion chamber 4 . Gas generator 1 by this fire
5 is burned, and the gas and combustion residue generated at that time are separated by the partition wall 16
The gas is filtered by the filter 3 arranged on the outer periphery of the combustion chamber 4 through the partition wall hole 17 provided in the above, and flows into the airbag (not shown) through the gas outlet port 18. Since the pressure inside the combustion chamber becomes high when the gas generating agent burns, the upper container 1 and the lower container 2 of the gas generator are firmly welded at the portions 19 and 20.

The igniter holder 13 is provided with a pedestal 41 having a certain strength as shown in FIG. 3, and is fixed to the container by a retaining ring 12. The material of the retaining ring is preferably a strong material such as a rope, and for example, a brushed special rope or a hard steel wire rod is preferable. As the retaining ring, a C-type retaining ring, an E-type retaining ring, a grip retaining ring, and a C-type concentric retaining ring are preferable, and particularly, a C-type concentric retaining ring (JI
S B2806) is not easy to remove and is good.

The container side is an igniter partition wall 2 as shown in FIG.
2 is provided with a taper 32 as needed, and a groove 31 is provided at a position where the holder can be fixed when the holder is inserted.
Note that the igniter 10 may be provided with a groove 40 for environmental sealing to prevent moisture from entering the combustion chamber, and the O-ring 11 may be attached thereto. When the igniter part 5 is pushed into the igniter partition wall 22 of the container together with such a retaining ring, the retaining ring is gradually compressed inward at the taper 32 and a sound is generated at the groove 31 of the igniter partition wall 22. The retaining ring spreads and the igniter part is fixed to the gas generator. Furthermore, an O-ring for environmental sealing prevents moisture from entering the combustion chamber. The position of the O-ring is not limited to a part of the igniter and may be attached to the holder. Further, it is effective that the insertion portion of the retaining ring has a larger diameter than the O-ring insertion portion so that the O-ring is not damaged when the igniter portion is inserted. Furthermore, the insertion position of the retaining ring can be attached to a part of the holder 13. The retaining ring may have a structure that cannot be easily removed, and for example, a part of the groove after fixing the retaining ring may be crushed.

[0010]

Since the gas generator of the present invention uses the retaining ring for fixing and holding the igniter, the gas generator can be attached in a shorter time than the screw type and has sufficient pull-out strength. In addition, the structure is simple and accuracy is less likely to occur. Since it can be installed without rotating like the screw type, it is easy to position the igniter pin. Furthermore, it is not necessary to additionally provide a screw lock or the like on the gas generator to prevent loosening of the screw and disassembly of the gas generator.

[Brief description of drawings]

FIG. 1 is a sectional view of a gas generator showing an embodiment of the present invention.

FIG. 2 is a sectional view showing a structure of a gas generator before insertion of an igniter portion.

FIG. 3 is a cross-sectional view showing the structure of an igniter.

[Explanation of Codes] 1 : Upper container 2 : Lower container 3 : Filter 4 : Combustion chamber 5 : Igniter part 10: Igniter 11: O-ring 12: Concentric snap ring 13: Igniter retainer 14: Igniter partition wall connecting hole 15: Gas generating agent 16: Combustion chamber partition wall 17: Combustion chamber partition wall hole 18: Gas outflow port 19: Welded portion of upper container and lower container 20: Welded portion of upper container and lower container 21: Igniter ignition pin 22: Igniter partition wall 23: Igniter chamber 31: Groove for container side concentric snap ring 32: Taper for igniter partition wall 40: Groove for O ring 41: Pedestal for concentric snap ring

Claims (1)

[Claims] 1. A gas generator comprising a container of a gas generator and an igniter portion, which is an ignition source, substantially connected to each other,
A gas generator characterized in that the container and the igniter portion of the gas generator are connected and fixed by a snap ring.