JP2632986B2 - Manufacturing method of emergency gas generator - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an improvement in a method of manufacturing an emergency gas generator used in an airbag for protecting a human body from various impacts in the field of transportation.

[Background Art] An airbag of an impact prevention safety device used for a high-speed vehicle such as an automobile or an aircraft includes an impact detection sensor, a gas generator, and an impact mitigation bag.

The gas generator is composed of a gas generating agent that generates a large amount of gas in a short time, a gas coolant, and an ignition device. Gas generating agents are explosive whose main sodium azide and an oxidizing agent, and exothermic decomposition at flame ignition agent, generates a large amount of hot gas short time, the gas generating chamber to a high pressure close to 100 kgf / cm ² Therefore, a pressure-resistant structure design is important for the pressure vessel that contains the gas generating agent. A conventional pressure vessel has a shape close to a cylinder or a sphere, and the connection between the outer cylinder and the head plate is performed by welding or fitting by screws. However, the welding method is
Approximately 200 ° C housed inside because the welded parts become hot
There is a danger that the gas generating agent ignited during the welding may ignite during the welding operation. In addition, since the screw fitting method is a high-pressure container, it is necessary to ensure the design strength accurately. Since the machining accuracy is important, the cost increases and there is a problem in securing the reliability. In addition, since the screw can be removed, for example, when this gas generator is installed in a car, there is a risk that the end plate fitted with the screw is maliciously removed, the gas generating agent that is explosive is taken out from the inside, and it is played with. There was a security problem.

[Problems to be solved by the invention]

SUMMARY OF THE INVENTION An object of the present invention is to provide an inexpensive gas generator that is free from these dangers in production and operation and that is highly reliable. Challenges include the lack of high temperatures in fabrication, the inability to remove, and the simple and accurate fabrication method.

[Means for solving the problem]

In the present invention, as a result of various studies on means for solving the above-mentioned problems, it has been found that it is most suitable to manufacture a gas generator by a roll caulking pressure bonding method, and the present invention has been reached.

That is, in the present invention, in forming a metal pressure vessel of a gas generator from an outer cylinder and a head plate, a groove having a cross-sectional concave shape is continuously dug in a circumferential direction of the head plate, and a predetermined position in the outer cylinder is provided. A convex roll corresponding to the concave groove is brought into contact with the outer peripheral surface of the outer cylinder facing the concave groove of the end plate installed in the end plate, and the outer cylindrical portion is continuously compressed and deformed, thereby fitting into the concave groove. The present invention provides a method for manufacturing a gas generator, characterized in that a pressure vessel is formed.

The manufacturing method of the present invention will be described with reference to the drawings. FIG. 1 shows a side surface of a head plate 1 of a pressure vessel of a gas generator, and a concave groove 2 having a semicircular, semielliptical or V-shaped cross section in a circumferential direction.
And dig deeper continuously and evenly. As shown in FIG. 2, the head plate 1 is installed at a predetermined position in the metal outer cylinder 3 of the pressure vessel of the gas generator. Next, as shown in FIG. 3, on the outer periphery of the outer cylinder 3 corresponding to the groove 2 of the end plate 1,
A caulking compression roll 4 having a cross-sectional shape similar to the channel shape 2 and having a radius smaller by the thickness of the outer cylinder is brought into contact, and the compression roll 4 gradually compresses and deforms the contact portion with the outer cylinder 3.
Compression is continued until the generated distortion corresponds to the shape of the groove 2 of the end plate 1 and the two fit together. If several compression rolls 4 are arranged at equal intervals on the outer periphery of the outer cylinder, this compression staking operation can be performed efficiently and with high accuracy. Numeral 11 indicates a formed caulking portion.

〔Example〕

Next, the present invention will be described with reference to examples, but the present invention is not limited to these examples.

Reference Example 1 (withstand pressure test) A 6 mm thick SUS is placed on both ends and 45 mm from both ends of a SUS304 cylinder 3 having an inner diameter of 60 mm, a length of 20 mm, and a thickness of 1.5 mm.
Four disc-shaped end plates made of 304 are installed. A semi-circular groove having a width of 4 mm and a depth of 2 mm is dug in advance around the entire outer periphery of these end plates. Four compression rolls having a convex radius of curvature of 2 mm are arranged in the circumferential direction of the outer cylinder with respect to the outer cylinder outer side facing the end plate groove, and the depth is set from the outer cylinder surface while rotating the compression rolls. Compression was continued until a strain of 2 mm was generated, and the deformed portion of the outer cylinder wall of the head plate was fitted to obtain a gas generator for a pressure resistance test. The inner two end plates are pre-drilled with a 10 mm diameter hole. A nipple for applying pressure was attached to the end plate, and a pressure test was performed by applying water pressure. A pressure of 130 kgf / cm ² was maintained for 2 minutes, but no breakage or deformation occurred.

Example 1 A gas generator shown in the schematic diagram of FIG. 4 was produced by the same method as that used in the pressure resistance test. However, diameter 20 at both ends of outer cylinder
The cold gas jet ports 5 of 12 mm are opened at regular intervals of 12 pieces. An igniter 6 is attached to the center of the outer cylinder, and a gas generating agent 7 is arranged near the center. A coolant 8 is disposed inside the vicinity of the cold gas outlet 5. 12 is the end plate,
Reference numeral 10 denotes a partition head plate, and reference numeral 11 denotes a caulked portion.

When an igniter of this gas generator is ignited by giving an impact signal thereto, the gas generating agent is ignited and a large amount of hot gas is generated. The hot gas is blown out from the outlet 9 of the separating head 10 and cooled by the coolant 8. , And continued to be normally ejected from the cooling gas ejection port 5 for 80 milliseconds. When the gas generator was inspected after the test, there was no abnormality such as gas leakage or swelling, and it was completely normal.

Example 2 In order to check the environmental resistance performance, a gas generator was subjected to a vibration with an acceleration of 1.5 grms corresponding to vibration of a 40,000 km vehicle on a rough road for 24 hours, and an operation test of the gas generator was performed in the same manner as in Example 1. I did, but I continued to blow out the gas normally for 80 milliseconds as well.

Example 3 After an impact acceleration of 40 g and 6 ms was applied to the gas generator, an operation test was performed in the same manner as in Example 1, but the gas was continuously blown out normally for 80 ms.

Example 4 After adjusting the temperature of the gas generator to 80 ° C., an operation test was performed in the same manner as in Example 1, but the gas was continuously normally blown out for 80 milliseconds.

Example 5 After adjusting the temperature of the gas generator to −50 ° C., an operation test was performed in the same manner as in Example 1, but the gas was continuously normally blown out for 80 milliseconds.

Embodiment 6 FIG. 5 is a schematic view of a cylindrical gas generator manufactured by the method of the present invention. Reference numeral 13 denotes an igniting agent particle, 14 denotes an igniting agent flame path, 15 denotes a flame outlet, 16 denotes a gas generating agent chamber cylinder, 17 denotes a gas generating agent chamber head plate, and 11 denotes a roll caulking portion.

When an impact signal is given to the igniter 6 of this gas generator to ignite it, the igniter flame is ejected from the flame outlet 15 through the duct 14, ignites the gas generating agent 7, and generates a large amount of hot gas. The hot gas was spouted from the spout 9 and cooled by the coolant 8 and continued to spout normally from the cooling gas spout 5 for 80 milliseconds. When the outer cylinder 3 and the cylinder 16 were cut and inspected after the test, there were no abnormalities such as gas leakage and swelling, and they were all normal.

〔The invention's effect〕

As shown in the embodiment, the present invention does not use a high temperature unlike welding, and is safe in manufacturing. Also the manufacturing process is simple,
It is reliable, and the product inspection can be performed easily, accurately, and in a short time by visual inspection. Further, since the gas generating device according to the present invention has the head plate and the outer cylinder uniformly caulked with a deep groove, taking out the internal explosive for toy purposes has no means other than strong destruction, so that operation and security are also improved. It is safe.

[Brief description of the drawings]

1 to 3 are partial views showing a state in which a head plate of the pressure vessel of the present invention is crimped and fitted to an outer cylinder. FIG. 1 is a side view of the head plate, and FIG. FIG. 3 is a view showing a state where the sheet is compressed and deformed by a roll from outside. FIG. 4 is a schematic diagram of a gas generator, and FIG. 5 is a schematic diagram of an inner cylinder type gas generator. 1: End plate 2: Concave groove 3: Outer cylinder 4: Compression roll 5: Cold gas outlet 10: Isolation end plate 11: Caulking section 12: End end plate

Claims (1)

(57) [Claims] When a metal pressure vessel of a gas generator is formed from an outer cylinder and a head plate, a groove having a cross-sectional concave shape is continuously dug in a circumferential direction of the head plate, and a predetermined position in the outer cylinder is formed. A convex roll corresponding to the concave groove is brought into contact with the outer peripheral surface of the outer cylinder facing the concave groove of the end plate installed in the end plate, and the outer cylindrical portion is continuously compressed and deformed, thereby fitting into the concave groove. And producing a pressure vessel.