JP2002370607A - Gas generator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a gas generator which can surely ignite a gas generating agent without increasing a charge amount of transfer charge. SOLUTION: This gas generator 1 of one cylinder type, comprising a short cylindrical housing 2 constituted of closure shell 2a and an initiator shell 2b, a filter material 11 provided over the circumferential direction in an internal periphery of the housing 2, and a gas generating agent 13 charged in a combustion chamber S formed in an internal periphery of the filter material 11 to generate gas by ignition and combustion, is provided in the inside with an ignition means 20 igniting the gas generating agent 13, to provide in the initiator shell 2b a charge cylinder unit 16 provided with a flame jet nozzle 18 jetting a flame from the ignition means 20 into the combustion chamber S, the gas generator is characterized by making the flame from the flame jet nozzle 18 jet in a jet direction toward the closure shell 2a of the housing 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to gas generation for use in automobiles and the like, and more particularly to a gas generator used for an airbag on the driver's seat side of an automobile.

[0002]

2. Description of the Related Art A gas generator for rapidly inflating and deploying an airbag in order to protect an occupant from an impact caused by a collision of an automobile is incorporated in an airbag module installed in a steering wheel or an instrument panel. I have. The gas generator ignites an igniter (squib) when energized by a control unit (actuator), and the flame burns a gas generating agent to rapidly generate a large amount of gas.

[0003] Among gas generators of this type, gas generators mainly used for driver-side airbags have hitherto been known.
For example, those shown in FIG. 5 are often used. As shown in FIG. 5, the gas generator 50 having the short cylindrical housing 55 is charged by the ignition of the igniter 51.
The transfer agent 53 in the cylinder 2 is ignited, and a flame is discharged from a flame outlet 54 formed in the loaded cylinder 52. Flame spout 54
The gas generating agent 56 loaded in the housing 55 is burned by the flame from the, and the gas is released from the gas discharge holes 58 through the filter material 57 to inflate the airbag.

[0004]

In recent years, gas generators have been converted from azide compounds using sodium azide to nitrogen-containing organic compound compounds in response to environmental and safety requirements. . However, gas generators based on nitrogen-containing organic compounds are less likely to ignite than gas generators based on azide, and it is necessary to raise the flame power to ignite the gas generator compared with gas generators based on azide. is there. Therefore, in order to increase the thermal energy of the flame from the igniter 51, it is necessary to increase the loading amount of the transfer agent 53. Therefore, there has been a problem with respect to downsizing of the gas generator.

The present invention has been made in view of the above-mentioned conventional problems, and an object of the present invention is to provide a gas generator which can reliably ignite a gas generating agent without increasing a charged amount of a transferring agent. I do.

[0006]

Means for Solving the Problems In the conventional gas generator, the ignition means provided at the center of the shaft ejects a flame in the circumferential direction, so that the force for igniting the gas generating agent is reduced. The present inventors have found that the problem of conversion is a problem, and have completed the present invention. That is, the gas generator according to claim 1 of the present invention for solving the above-mentioned problem has a short cylindrical shape composed of an initiator shell provided with ignition means and a closure shell closing the initiator shell. A housing, a filter material provided on the inner circumference of the housing in a circumferential direction, and a gas generating agent which is loaded into a combustion chamber formed on the inner circumference of the filter material, ignites, and generates gas by combustion. Prepare
A one-cylinder gas provided in the initiator shell is provided with an ignition means for igniting the gas generating agent, and a charging cylinder body provided with a flame ejection port for emitting a flame from the ignition means into the combustion chamber. The generator is characterized in that the flame from the flame spout is in a spouting direction toward the closure shell of the housing. According to such a configuration, the original dust collection and cooling functions can be exhibited with the minimum filter material. In addition, the gas generating agent loaded above the charging cylinder serving as the ignition means is selectively ignited, and the other heat generating agent in the combustion chamber is ignited by the combustion heat of the gas generating agent, so that the gas generating agent is efficiently used. The gas generant can be ignited.

According to a second aspect of the present invention, in the gas generator according to the first aspect, the loading cylinder has a bottomed cylindrical shape including a side cylinder and a bottom, and the bottom is the closure shell. And the flame outlet is formed at the bottom. Since the flame is ejected only from the bottom of the loaded cylinder, the ejection location is limited as compared with the case where the flame is ejected from the side cylinder. For this reason, it is possible to reduce the amount of the transfer agent charged in the ignition means, and it is possible to reduce the size of the gas generator.

According to a third aspect of the present invention, there is provided the gas generator according to the first or second aspect, wherein a partition plate is provided between the filter material and the loading cylinder, and the space is defined by the partition plate. To selectively ignite the gas generating agent inside. According to such a configuration, the flame from the ignition means is trapped in the space defined by the partition plate, and first, the gas generating agent loaded in the space defined by the partition plate is ignited first, and Since the heat and the gas propagate to the gas generating agent in the combustion chamber, the entire gas generating agent in the combustion chamber can be ignited. Since the thermal energy from the ignition means is stored in the space defined by the partition plate, the gas generating agent can be efficiently ignited. Further, it is possible to reduce the amount of the transfer agent charged in the ignition means.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a cross-sectional view showing one embodiment of the gas generator according to the present invention. In a gas generator 1 shown in FIG. 1, a short cylindrical housing 2 is constituted by a lower lid 2b serving as an initiator shell provided with an ignition means and an upper lid 2a serving as a closure shell closing the initiator. In the housing 2, an ignition means 20, a gas generating agent 13, and a filter material 11, which are composed of a charging cylinder 16 provided therein with an igniter 9 and a transfer agent 17 in order from the center
Is arranged. The upper lid 2a and the lower lid 2b are formed of a metal material such as iron or steel. The iron or steel to be used is not particularly limited as long as it is generally used for forging, drawing, press forming, and the like, such as wrought iron, iron, steel, and alloy steel.

The upper cover 2a comprises a top plate 3 and a side tube 5 extending downward from the entire periphery thereof and provided with a large number of gas discharge ports 4.

The lower lid 2b includes a bottom plate 6, a side cylinder 7 extending upward from the entire periphery thereof, a flange 8 extending horizontally outward from the side cylinder 7, and an airbag module (not shown) being attached thereto. Consists of At the center of the bottom plate 6, an igniter holding portion 10 for caulking and fixing the igniter 9 is integrally formed.

The upper lid 2a and the lower lid 2b are formed by repeating partial pressurized flow. Here, the repetition of partial pressurized flow refers to partial repetition of general forging, drawing, and the like. Therefore,
The upper lid 2a and the lower lid 2b are made of one sheet of iron or steel or one piece of block of iron or steel, using a mold or the like corresponding to each part, forging, drawing, pressing, etc. Are molded in combination.

The upper lid 2a and the lower lid 2b thus formed are joined together by the side tube 5 and the side tube 7 to form a one-tube, short cylindrical housing 2. Here, as a joining method, electron beam welding, laser welding, friction welding, or the like can be used.

In the housing 2, a filter material 11 is moved from the upper lid 2 a to the lower lid 2 along the side tube portions (side tube 5 and side tube 7).
b, and is held by a holding lid member 12 disposed inside the top plate 3 of the upper lid 2a. Filter material 1
A combustion chamber S is formed on the inner periphery of the fuel cell 1 and a gas generating agent 13 is loaded therein.

At the approximate center of the housing 2, a side cylindrical portion 16 is provided.
A charging cylinder 16 composed of a and a bottom 16b is loaded with a transfer medium 17 therein, fitted into an igniter holding section 10 formed on the lower lid 2b, and ignited together with the igniter 9 20
Is composed.

At the lower end on the inside of the filter material 11,
A ring member 14 having an L-shaped cross section is disposed in contact with the filter material 11 at the outer peripheral edge and the loading cylinder 16 at the inner peripheral end. The presser lid member 12 and the ring member 14 both serve to prevent the generated gas from flowing out of the gap between the inner surface of the housing 2 and the filter material 11 when the housing 2 is deformed when the gas generator 1 is operated. . In addition, the upper lid 2a
A seal member (aluminum foil member or the like) 15 is adhered to the inside of a number of gas discharge ports 4 provided in the side cylinder 5 to ensure airtightness in the housing 2.

The charging cylinder 16 constituting the ignition means 20 is
It has a bottomed tubular shape composed of a side tubular portion 16a and a bottom portion 16b. The loading cylinder 16 is fitted to the igniter holder 10 formed integrally with the lower lid 2b. And the bottom 1
A flame outlet 18 is formed at the center of 6b, so that the flame from the loading cylinder 16 is ejected toward the upper lid 2a. It should be noted that the flame outlet 18 is a
It suffices if it is formed so as to be ejected toward a, and a plurality may be provided on the bottom 16b. In addition, bottom 1
It may be provided at the corner between 6b and the side cylinder 16a.

The loading cylinder 16 is not limited to the bottomed cylindrical shape as shown in the present embodiment, but is formed, for example, so that the flame outlet 18 opens in the direction of the closure shell. If it does, it can also be made hemispherical or conical.

Next, the procedure for assembling the gas generator 1 shown in FIG. 1 will be described with reference to FIG. First, a packing (not shown) is attached to the igniter holding portion 10 of the lower lid 2b so that the igniter 9
And fix it. Then, the loaded cylindrical body 16 in which the transfer agent 17 is loaded is fitted to the igniter holder 10. Next, the ring member 14 is inserted and arranged, and the filter material 11 is inserted. The gas generating agent 1 is placed inside the filter material 11.
3 and the presser cover member 12 is arranged. Finally, the gas outlet 4 is covered with an upper lid 2a which is sealed with a sealing member 15,
When the lower lid 2b and the upper lid 2a are joined, the gas generator 1 shown in FIG. 1 is obtained.

Next, the operation of the gas generator of this embodiment will be described with reference to FIG. When a collision detection device disposed in the vehicle detects a collision of the vehicle, the igniter 9 is ignited according to the detection signal, and the charging cylinder 1 is ignited by the ignition flame.
The transfer agent 17 in 6 is ignited. The flame in which the heat energy of the flame from the igniter 9 is increased by the transfer agent 17 is
Flame outlet 18 formed at bottom 16b of loading cylinder 16
Squirted from. The flame from the flame outlet 18 is ejected toward the upper lid 2a, which is a closure shell of the housing 2, and selectively burns the gas generating agent 13 located in the space S1 above the loading cylinder 16. Then, the combustion heat of the gas generating agent 13 which is burned earlier causes the combustion chamber S
The gas generating agent 13 located in another space S2 in the interior burns.

Further, as described above, the flame is applied to the filter material 1.
Since the filter material 11 does not hit directly, it is possible to prevent the filter material 11 from being damaged. Further, the flame from the flame outlet 18 is ejected in the direction of the upper cover 2a of the housing 2, and the charged cylindrical body 1 is opened.
6, the gas generating agent 13 located in the space S1 above is selectively ignited, and the heat of combustion of the gas generating agent 13 causes another gas generating agent 13 loaded in another space S2 in the combustion chamber S to be ignited. Therefore, the flame from the flame outlet 18 can be efficiently used to ignite the gas generating agent 13.
For this reason, it is possible to reduce the amount of the transfer agent 17 to be loaded into the loading cylinder 16, and it is possible to reduce the size of the gas generator 1.

Here, as a gas generating agent usable in the present invention, a nitrogen-containing organic compound such as a tetrazole compound, a triazole compound, an azodicarboxylic acid amide compound or a guanidine compound is used as a fuel, and a nitrate,
An organic compound gas generating agent obtained by adding and mixing an oxidizing agent such as an oxohalogenate can be exemplified.

The gas generator of the present invention is not limited to the above-described embodiment. For example, as shown in FIG. 2, a flame outlet 18 is formed at the bottom 16b of the charging cylinder 16. A partition plate 19 can be provided between the filter member 11 and the filter member 11. As a result, the combustion chamber S is partitioned into a space S2 surrounded by the inner periphery of the partition plate 19 and the bottom 16b of the loading cylinder 16, and the other space S1, and the gas generating agent 13 in the space S2 is further separated. Ignition can be performed more efficiently. In FIG. 2, the same members as those in FIG. 1 are denoted by the same reference numerals, and detailed description will be omitted.

In FIG. 2, by forming the partition plate 19 on the holding lid member 12 so as to be located between the filter material 11 and the loading cylinder 16, the flame from the flame outlet 18 can be separated from the partition plate 19. As a result, the gas generating agent 13 efficiently stays in the space S2 and is selectively ignited. Then, the gas generating agent 13 in the space S1
The other gas generating agent 13 loaded in the space S2 of the combustion chamber S is ignited by the heat of combustion caused by the ignition of. Thus, when the gas pressure in the housing 2 rises and reaches a predetermined pressure, the seal member 15 is ruptured, and a high-pressure gas is ejected from the gas discharge port 4 to instantaneously inflate an airbag (not shown). Let it unfold.

As described above, the flame spouted from the flame spout 18 efficiently spills the flame into the space S2 by the partition plate 19 and the charging cylinder 16, thereby causing the gas generating agent 13 located in the space S2 to flow. Selectively ignite and its gas generating agent 1
Since the other gas generating agent 13 loaded in the space S1 is ignited by the combustion heat of 3, the flame from the flame outlet 18 can be efficiently used for igniting the gas generating agent 13. For this reason, the transfer agent 1 to be loaded into the loading cylinder 16 is
7 can be reduced, and the size of the gas generator 1 can be reduced.

By providing the partition plate 19 on the holding lid member 12 in this manner, as shown in FIG. It can also be provided on the side cylindrical portion 16a of the body 16. In this case, the side cylindrical portion 16a of the loading cylindrical body 16
The partition plate 19 is interposed on the projection surface of the flame outlet 18a provided on the projection surface facing the filter material 11. With such a configuration, the bottom portion 1 of the loading cylinder 16 is
The flame from the flame outlet 18a of 6b and the flame from the flame outlet 18a of the side cylindrical portion 16a are separated by the partition plate 19.
The filter material 11 can be protected without directly hitting the filter material 11. Further, since the flame is efficiently trapped in the space S1 by the partition plate 19, the same effect as described above can be obtained.
It is possible to reduce the loading amount of the gas generator 1
Can be reduced in size. Note that the partition plate 19 need not be provided as long as the flame can be jetted toward the closure shell.

[0027]

The present invention will be described below in detail with reference to examples. (Example 1) Guanidine nitrate: 53.0 parts by weight as a nitrogen-containing organic compound component, nitrate containing strontium nitrate as a main component as an oxidant component: 43.6 parts by weight, acid clay as a binder: 3.0 parts by weight, and As a lubricant, magnesium stearate: 0.4 part by weight was dry-mixed with a V-type mixer. Then, 6.1 mm in diameter with a rotary tableting machine,
Press-molded into a 1.5 mm high shape,
After drying for a time, tablets of the gas generating composition used in this example were obtained. 36 g of this tablet was loaded into a gas generator having an inflator structure shown in FIG. 0.8 g of boron nitrite was used as a transfer medium. After attaching this gas generator to a container having an inner volume of 60 liters, the gas generator was operated to release gas into the container, and the time change of the pressure in the container was measured.

Example 2 A 60-liter tank test was conducted using the same gas generating agent and transfer agent as in Example 1 except that the gas generator shown in FIG. 2 was used.

Comparative Example 1 A 60-liter tank test was conducted using the same gas generating agent and explosive as in Example 1 except that the gas generator shown in FIG. 5 was used.

Table 1 and FIG. 4 summarize the test results of the 60-liter tank test.

[0031]

[Table 1]

As shown in Tables 1 and 4, the gas generator shown in FIGS. 1 and 2 in which the flame from the flame outlet blows out in the direction of the closure shell of the housing, the pressure rises without delay of ignition of the gas generating agent. Further, it was confirmed that the filter material after the operation was not damaged. However,
In the gas generator shown in FIG. 5 in which the direction of the flame jet from the flame outlet is not changed and is jetted in the direction of the filter material located in the circumferential direction of the housing, an ignition delay occurs. In this state, the occupant protection performance is reduced. Undesirably, it is necessary to increase the amount of transfer charge.

[0033]

As described above, according to the gas generator according to the present invention, the gas generating agent can be efficiently and reliably ignited even with a small amount of the transferring agent. This has the effect that the size and cost of the device can be reduced.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view of an embodiment of a gas generator according to the present invention.

FIG. 2 is a schematic sectional view of another embodiment of the gas generator according to the present invention.

FIG. 3 is a schematic cross-sectional view of another embodiment of the gas generator according to the present invention.

FIG. 4 is a diagram showing a 60-liter tank test result.

FIG. 5 is a schematic sectional view showing an example of a conventional gas generator.

[Description of Signs] S Combustion chamber S1, S2 Space 1 Gas generator 2 Housing 2a Upper lid (closure shell) 2b Lower lid (Initiator shell) 3 Top plate 4 Gas discharge hole 5 Side tube 6 Bottom plate 7 Side tube 8 Flange 9 Ignition device 10 Ignition device holding portion 11 Filter material 12 Holding lid member 13 Gas generating agent 14 Ring member 15 Seal member 16 Loading cylinder 16a Side cylinder 16b Bottom part 17 Transfer agent 18 Flame outlet 19 Partition plate 20 Ignition means

Claims (3)

[Claims] 1. A short cylindrical housing composed of a closure shell and an initiator shell, a filter material provided circumferentially on an inner periphery of the housing, and a combustion chamber formed on an inner periphery of the filter material. A gas generating agent that generates gas by ignition and combustion; and a flaming means for igniting the gas generating agent therein; and a flame outlet from which a flame from the igniting means blows out into the combustion chamber. Is a one-cylinder gas generator provided in the initiator shell, wherein the flame from the flame outlet is in a jetting direction toward the closure shell of the housing. And gas generator. 2. The charging cylinder body has a bottomed cylindrical shape including a side cylinder part and a bottom part, and the bottom part is disposed so as to face the closure shell. The gas generator according to claim 1, wherein the gas generator is formed. 3. The gas supply system according to claim 1, wherein a partition plate is provided between the filter material and the loading cylinder, and a gas generating agent in a space defined by the partition plate is selectively ignited. Gas generator.