JP2008149837A - Gas generator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a gas generator 100 capable of securing a gas flow passage of gas generated in a combustion chamber 3 and relaxing an increase of pressure in a housing 1. <P>SOLUTION: This gas generator is provided with the long cylindrical housing 1 having a filter 4 at the inside, the combustion chamber 3 formed in the housing 1 and filled with gas generating agent 2 for generating high temperature gas by combustion, a gas generating agent ignition means including igniting powder 6, mounted at an end part on the combustion chamber 3 side in the housing 1 and igniting and burning the gas generating agent 2 in the combustion chamber 3, and a gas discharge cylinder 12 mounted at an end part on the filter 4 side in the housing 1. In the combustion chamber 3, a coil spring 16 is provided from one end to the other end of the combustion chamber 3 along a length direction of the housing 1. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a gas generator for inflating an air bag or the like, and more particularly to a gas generator suitable for inflating a side or curtain airbag or the like.

In the gas generator used for the side collision, the ignition means is operated when the collision is received, and the gas generating agent is ignited and burned by the generated flame to generate gas. Therefore, it is necessary to fill the gas generator with a sufficient gas generating agent.
However, when the filling amount of the gas generating agent is increased, the speed at which the generated gas passes through the housing is reduced, so that the expansion and expansion of the airbag is delayed. Further, the gas generated in the housing increases the pressure inside the housing, and it is not easy to ensure the strength safety factor of the housing.

  Examples of the gas generator that effectively burns the gas generating agent in the entire housing include those disclosed in Patent Document 1 below. The gas generator disclosed in Patent Document 1 includes a long cylindrical housing, a combustion chamber formed in the housing, loaded with a gas generating agent that generates high-temperature gas by combustion, and having a filter, An ignition device housing chamber that houses an ignition device that is formed in the housing and ignites and burns the gas generating agent in the combustion chamber, and is disposed in the combustion chamber over its length direction. A hollow cylindrical heat transfer tube is provided.

JP 2005-8093 A

  However, in the gas generator as in Patent Document 1, although the flame of the ignition charge that has been ignited and burned can be efficiently transferred to the gas generation agent, it is easy to mitigate the increase in the pressure in the housing caused by the generated gas. It was not.

  Accordingly, the present invention provides a gas generator that can relieve the pressure increase in the housing due to the gas generated in the combustion chamber and ensure a gas flow path through which the generated gas can easily pass through the housing. With the goal.

Means and effects for solving the problems

(1) A gas generator of the present invention includes a long cylindrical housing having a filter therein, a combustion chamber formed in the housing and loaded with a gas generating agent that generates high-temperature gas by combustion, Gas generating agent ignition means containing explosives, attached to the end of the housing on the side of the combustion chamber and igniting and burning the gas generating agent in the combustion chamber, and attached to the end of the housing on the filter side The gas generator includes a gas discharge cylinder, and a winding spring is provided in the combustion chamber from one end of the combustion chamber to the other end along the length direction of the housing.

  According to the configuration of (1) above, the generated gas passes through the hollow cylindrical portion inside the winding spring, and a gas flow path inside the housing can be secured, so that an increase in pressure inside the housing can be prevented. It is possible to provide a gas generator capable of further improving the strength safety factor of the housing.

(2) In the gas generator of the present invention, the spiral spring has a spiral member having a central portion connected to the end of the spiral spring on the filter side, and the central axis of the spiral spring and the housing It is preferable that the central axis is substantially the same.

  According to the configuration of (2) above, the winding spring is fixed by the spiral member, the central axis of the winding spring and the central axis of the housing are substantially the same, and the gas generating agent is uniformly filled around the winding spring. Therefore, it is possible to provide a gas generator capable of uniformly igniting and burning the gas generating agent.

(3) In the gas generator of the present invention, the gas discharge cylinder has a gas flow passage formed therein so as to have an opening at the combustion chamber side end, and an end opposite to the opening. A gas discharge hole formed so that the gas flow path and the outside communicate with each other around the periphery, and a cross-sectional area of the opening of the gas flow path is larger than a cross-sectional area in the middle of the gas flow path It is preferable. Here, for example, the cross-sectional shape from the opening of the gas flow path to the inside of the gas flow path may be a stepped shape having one or more steps, or the gas flow from the opening of the gas flow path. The cross-sectional shape in the middle of the flow path may be a tapered shape. The filter may be provided inside the combustion chamber, or the combustion chamber and the filter may be separated into separate chambers.

  According to the configuration of (3) above, although the configuration is simple, the vicinity of the corner of the filter on the side of the gas discharge cylinder can also be used effectively, so that a further cooling effect can be obtained compared to the conventional gas generator. Gas generator can be provided. In addition, the gas generated in the combustion chamber is more easily removed from the filter, and the pressure in the combustion chamber is lowered. Therefore, the strength safety factor of the housing can be sufficiently secured.

(4) In the gas generator of the present invention, it is preferable that a plate member having a plurality of holes is provided between the filter and the opening of the gas flow path.

  According to the configuration of (4) above, since the plate member and the end surface on the plate member side of the filter are in contact with each other, the shape of the filter can be prevented from being deformed even when high-temperature gas is passing. The filter can be used efficiently until gas generation is completed.

<First embodiment>
Hereinafter, a gas generator according to a first embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a cross-sectional view of a gas generator according to a first embodiment of the present invention. FIG. 2 is a perspective view of a spiral spring and a spiral member of the gas generator according to the first embodiment of the present invention.
In FIG. 1, the gas generator 100 has a central portion connected to a long cylindrical housing 1, a gas generating agent 2 that generates high-temperature gas by combustion, a winding spring 16, and one end of the winding spring 16. A combustion chamber 3 having a spiral member 17, a filter 4 disposed in the housing 1 adjacent to the combustion chamber 3, and a source for igniting and burning the gas generating agent 2 in the combustion chamber 3 An igniter 5 that generates a flame, an enhancer cup 7 that contains a transfer agent 6 that amplifies the energy of the flame generated by the igniter 5, and a holder 8 that is fixed by caulking the igniter 5 and the enhancer cup 7 respectively. And have. The igniter 5, the transfer agent 6, the enhancer cup 7, and the holder 8 fixed by caulking at the shaft end 9 of the housing 1 function as an ignition means for the gas generating agent 2. Have. Further, a plate-like cushion material 10 which is also a partition member is provided between the ignition means and the gas generating agent 2. Further, a gas discharge cylinder 12 that is caulked and fixed is provided at the shaft end portion 11 of the housing 1.

  In the housing 1, the cushion material 10, the combustion chamber 3 (including the gas generating agent 2, the winding spring 16, and the spiral member 17) and the filter 4 are arranged in this order from the ignition means to the gas release cylinder 12. Filled. The housing 1 is made of a metal such as iron, for example.

  The winding spring 16 is a spring formed of a metal wire such as a piano wire, a hard steel wire, or a stainless steel wire. The winding spring 16 is provided in the combustion chamber 3 along the length direction of the housing 1 from the end on the cushion 10 side of the combustion chamber 3 to the end on the filter 4 side. Further, the central portion of the spiral member 17 is connected to the end portion of the winding spring 16, and the central axis of the winding spring 16 and the central axis of the housing 1 are substantially the same.

 The cushion material 10 is disposed so as to hold the gas generating agent 2 in the combustion chamber 3 together with the filter 4 and suppresses the gas generating agent 2 from being powdered by vibration.

  The filter 4 is, for example, a cylindrical one formed by an aggregate of knitted wire mesh, plain weave wire mesh, or crimp woven metal wire. Further, one end of the filter 4 is in contact with a part of the surface at one end of the gas discharge cylinder 12, and the other end is adjacent to the combustion chamber 3.

  As shown in FIG. 1, the enhancer cup 7 has a single hole 7 a at the bottom that comes into contact with the cushion material 10. A seal member 19 is affixed inside the hole 7a. Here, as a modification, the seal member 19 may be attached to the outside of the hole 7a. Further, the flange formed in the opening of the enhancer cup 7 is caulked and fixed by the protrusion of the holder 8. The enhancer cup 7 is made of a metal material such as iron that is relatively hard and resistant to heat. As a modification, a plurality of holes may be formed in the bottom of the enhancer cup 7. As another modification, the enhancer cup 7 may be made of aluminum without holes. The aluminum enhancer cup 7 having no holes can be ruptured by ignition combustion of the transfer agent.

  The igniter 5 is energized and ignited based on a collision signal from a collision sensor, jets a flame into the enhancer cup 7, ignites the transfer agent 6, and then forcibly ignites and burns the gas generating agent 2. It is.

  The holder 8 holds the igniter 5 and the enhancer cup 7. The holder 8 is fitted into one end of the housing 1 and is held by caulking together with the shaft end 9 of the housing 1 to close one end of the housing 1.

  The gas discharge cylinder 12 is fitted into the other end portion of the housing 1, held by caulking together with the shaft end portion 11 of the housing 1, and the other end of the housing 1 is closed. The gas discharge cylinder 12 is a cylindrical member having a strength capable of withstanding the internal pressure of gas flowing into a gas flow path 13 to be described later, and has an opening 13a at the end on the combustion chamber 3 side. And a gas discharge hole 14 formed so that the gas flow channel 13 and the outside communicate with each other around the end portion on the opposite side of the opening 13a. The gas flow path 13 is formed so that a long cylindrical first space 13b having a small diameter and a short cylindrical second space 13c having a large diameter are coaxially connected to each other. The cross-sectional area of the opening 13a is larger than the cross-sectional area in the middle of the gas flow path 13 (for example, the area in the cross-sectional portion of the second space 13c), and the cross-section of the portion from the opening 13a to the first space 13b. Is formed in a staircase shape (one step). Here, as a modification, instead of forming the second space 13c (with a one-step staircase shape), the cross section of the portion from the opening 13a to the first space 13b has a staircase shape with two or more steps. You may form as follows. In the gas flow path 13, a seal member 15 is attached to the second space 13 c side of the boundary between the first space 13 b and the second space 13 c.

  Next, the operation of the gas generator 100 will be described. When the collision sensor detects an automobile collision, a signal is sent to the igniter 5 of the gas generator 100, and an igniter (not shown) is ignited in the igniter 5, thereby generating gas and flame. The gas and flame of the igniter 5 are ejected into the enhancer cup 7 to efficiently ignite and burn the transfer agent 6. Then, the flame generated from the ignited transfer agent 6 breaks the seal member 19 and blows out in the combustion chamber 3 through the hole 7a so as to spread in the axial direction and the radial direction of the housing 1 to burn the cushion material 10. At the same time, the gas generating agent 2 is ignited and burned to efficiently generate a high-temperature gas. The ignition combustion of the gas generating agent 2 is sequentially transferred from the one end side of the housing 1 to the filter 4 side.

  Most of the hot gas generated in the combustion chamber 3 flows into the hollow cylindrical portion of the spiral spring 16 and then moves from the one end side of the housing 1 to the filter 4 side.

  When combustion in the combustion chamber 3 proceeds and the combustion chamber 3 rises to a predetermined internal pressure, the high-temperature gas generated in the combustion chamber 3 enters the filter 4, where slag collection and cooling occur, It becomes clean gas. Thereafter, this gas flows from the opening 13a in the gas discharge cylinder 12 into the second space 13c. Then, after the seal member 15 is ruptured, the seal member 15 flows into the first space 13 b, and the above-described clean gas is discharged from the gas discharge hole 14.

  As a result, the sufficiently cooled clean gas discharged from the gas discharge hole 14 is directly introduced into the interior of the air belt, the air bag or the like, and efficiently and instantaneously expands.

  According to the present embodiment, the gas generated in the combustion chamber 3 quickly moves to the filter 4 side, and the gas generated in the combustion chamber 3 is more easily removed from the filter 4 so that the pressure in the combustion chamber 3 decreases. Therefore, the sufficient strength safety factor of the housing 1 can be ensured. In addition, the gas generator 100 capable of obtaining a further cooling effect as compared with the conventional gas generator can be effectively used since the vicinity of the corner portion of the filter 4 on the side of the gas release cylinder 12 can be effectively used while having a simple configuration. Can be provided.

<Modification of First Embodiment>
Next, the gas generator which concerns on the modification of 1st Embodiment of this invention is demonstrated. FIG. 3 is a cross-sectional view of a gas generator according to a modification of the first embodiment of the present invention. In addition, each part to which the codes | symbols 1-11, 14-17, and 19 in the gas generator 100 in 1st Embodiment are given, and each part to which the codes | symbols 21-31, 34-37, and 39 are given in this modification. Are the same in order, and the description may be omitted.

  In the gas generator 200 of this modification, the cross section of the portion from the opening 33a of the gas flow path 33 in the gas discharge cylinder 32 to the cylindrical first space 33b has a tapered shape (from the opening 33a to the first space 33b. The second embodiment is different from the gas generator 100 of the first embodiment in that the second space 33c has a shape reduced in diameter to the second space 33c.

  According to this modification, the same operation and effect as in the first embodiment can be obtained.

<Second Embodiment>
Next, a gas generator according to a second embodiment of the present invention will be described. FIG. 4 is a sectional view of a gas generator according to the second embodiment of the present invention. In addition, each part to which the code | symbols 1-17, 19 in the gas generator 100 in 1st Embodiment are given, and each part to which the code | symbols 41-57, 59 are given in this embodiment are the same in order. Therefore, description may be omitted.

  The gas generator 300 according to the present embodiment is different from the gas generator according to the first embodiment in that a plate member 58 having a plurality of holes 58a is provided between the filter 44 and the opening 53a of the gas flow path 53. Different from the vessel 100. The surface of the plate member 58 on the filter 44 side and one end surface of the filter 44 are in contact with each other.

  Next, the operation of the gas generator 300 will be described. When the collision sensor detects an automobile collision, a signal is sent to the igniter 45 of the gas generator 300, and an igniter (not shown) is ignited in the igniter 45, thereby generating gas and flame. The gas and flame of the igniter 45 are jetted into the enhancer cup 47, and the transfer agent 46 is ignited and burned efficiently. Then, the flame generated from the ignited transfer agent 46 breaks the seal member 59 and blows out in the combustion chamber 43 through the hole 47a so as to expand in the axial direction and the radial direction of the housing 41, and the cushion material 50 is burned. In addition, the gas generating agent 42 is ignited and burned to efficiently generate a high-temperature gas. The ignition combustion of the gas generating agent 42 is sequentially shifted from one end side of the housing 41 to the filter 44 side.

  Most of the high-temperature gas generated in the combustion chamber 43 flows into the hollow cylindrical portion of the spiral spring 56 and then moves from the one end portion side of the housing 41 to the filter 44 side.

  When combustion in the combustion chamber 43 proceeds and the combustion chamber 43 rises to a predetermined internal pressure, the high-temperature gas generated in the combustion chamber 43 enters the filter 44, where it passes through slag collection and cooling, It becomes clean gas. Thereafter, the gas passes through the hole 58 a of the plate member 58 and flows into the second space 53 c from the opening 53 a in the gas discharge cylinder 52. Then, after the seal member 55 is ruptured, the seal member 55 flows into the first space 53 b, and the above-described clean gas is discharged from the gas discharge hole 54.

  As a result, the sufficiently cooled clean gas discharged from the gas discharge hole 54 is directly introduced into the interior of the air belt, the air bag, etc., and efficiently and instantaneously expands.

  According to this embodiment, the same effect as that of the first embodiment can be obtained. Further, since the surface of the plate member 58 on the filter 44 side and the end surface of the filter 44 on the plate member 58 side are in contact, the shape of the filter 44 is prevented from being deformed even when high-temperature gas is passing. Therefore, the filter 44 can be used efficiently until the generation of gas is completed.

  The present invention can be changed in design without departing from the scope of the claims, and is not limited to the above-described embodiments and modifications. For example, in the second embodiment, as in the modification of the first embodiment, the cross section of the portion from the opening 53a of the gas flow channel 53 in the gas discharge cylinder 52 to the first space 53b may be tapered. It is good also as a step shape of two or more steps.

  Further, in the first and second embodiments and the modified example of the first embodiment, without forming the second space, the entire first space has a stepped shape or a tapered shape having an opening connected to the filter. There may be a stepped shape or a tapered shape up to the middle of the first space.

It is sectional drawing of the gas generator which concerns on 1st Embodiment of this invention. It is a figure for demonstrating the spiral spring and coiled member of the gas generator which concern on 1st Embodiment of this invention. It is sectional drawing of the gas generator which concerns on the modification of 1st Embodiment of this invention. It is sectional drawing of the gas generator which concerns on 2nd Embodiment of this invention.

Explanation of symbols

1, 21, 41 Housing 2, 22, 42 Gas generating agent 3, 23, 43 Combustion chamber 4, 24, 44 Filter 5, 25, 45 Igniter 6, 26, 46 Fire transfer agent 7, 27, 47 Enhancer cup 7a 27a, 47a Hole 8, 28, 48 Holder 9, 11, 29, 31, 49, 51 Shaft end 10, 30, 50 Cushioning material 12, 32, 52 Gas discharge cylinder 13, 33, 53 Gas flow path 13a, 33a, 53a Openings 14, 34, 54 Gas discharge holes 15, 19, 35, 39, 55, 59 Seal members 16, 36, 56 Winding springs 17, 37, 57 Member 58a Hole 58 Plate members 100, 200, 300 Gas Generator

Claims (6)

A long cylindrical housing with a filter inside;
A combustion chamber formed in the housing and loaded with a gas generating agent that generates a high-temperature gas by combustion;
A gas generating agent igniting means that contains ignition powder, is attached to an end of the housing on the combustion chamber side, and ignites and burns the gas generating agent in the combustion chamber;
A gas generator comprising a gas discharge cylinder attached to an end of the housing on the filter side,
A gas generator comprising a winding spring in the combustion chamber from one end to the other end of the combustion chamber along the length direction of the housing. A spiral member having a central portion connected to the end of the coil spring on the filter side,
The gas generator according to claim 1, wherein a central axis of the winding spring and a central axis of the housing are substantially the same. The gas discharge cylinder communicates between the gas flow path formed inside so as to have an opening at the end on the combustion chamber side, and the outside around the end opposite to the opening. And a gas discharge hole formed to
The gas generator according to claim 1 or 2, wherein a cross-sectional area of the opening of the gas flow path is larger than a cross-sectional area in the middle of the gas flow path.   4. The gas generator according to claim 3, wherein a cross-sectional shape from the opening of the gas flow path to the middle of the gas flow path is a stepped shape having one or more steps.   4. The gas generator according to claim 3, wherein a cross-sectional shape from an opening of the gas flow channel to a middle portion of the gas flow channel is a tapered shape. The gas generator according to any one of claims 3 to 5, wherein a plate member having a plurality of holes is provided between the filter and the opening of the gas flow path.

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