JP2018012415A - Inflator of airbag device, filter for inflator of airbag device, and airbag device, and manufacturing method of inflator of airbag device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent fracturing etc. of a gas generating agent in a housing and easily prevent scattering of a solid matter during operation of an inflator.SOLUTION: A filter 100 for an inflator of an airbag device having a hollow cylindrical filter member 101 further includes a coil spring 102. The coil spring 102 has: a large diameter part 102a wound around an outer peripheral surface of the filter member 101; a conical part 102b having a coil diameter reducing from the large diameter part 102a toward a one-end part; and an end coil part 102c at the small diameter side of the conical part 102b.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an inflator or the like used in an airbag device as an occupant protection device mounted on an automobile or the like.

  An air bag device ignites a gas generating agent (explosive) in an inflator at the time of an automobile collision accident to generate a gas explosively, and the air bag is inflated and deployed by this gas. It is intended to alleviate the impact and to ensure the safety of passengers.

  The inflator is configured, for example, by filling explosives in a short cylindrical housing. As said explosive, what was shape | molded in granular form, pellet shape, column shape, disk shape etc. is used. In addition, in order to prevent the explosives molded into the granular form from being crushed by vibration or the like and becoming powdered, cushions such as foams mainly composed of a group consisting of polyurethane resin, polypropylene resin and chloroprene rubber There is known a technique for keeping a lightly pressed state by a material (for example, see Patent Document 1).

  Further, a plate spring portion is provided on the top plate so as to press the gas generating agent (see, for example, Patent Document 2), or as a top plate, a metal net member or a metal plate-like member in which fine holes are formed. There is also known a technique in which a gas generating agent is pressed by the elasticity of the top plate using a bent material (see, for example, Patent Documents 3 and 4).

JP 2012-254728 A JP 2007-290620 A Japanese Patent Laid-Open No. 2006-11086 JP 2016-13748 A

  When foamed silicon or the like is used as a cushioning material as described above, it is difficult to prevent scattering with the explosive combustion during operation of the inflator.

  Further, when a plate spring portion is provided on the top plate or a bent top plate is used, there is a tendency to increase the cost due to material loss due to plate cutting or press stroke work.

  The present invention has been made in view of the above points, and prevents the gas generating agent from being crushed in the housing, and can easily prevent solids from being scattered during the operation of the inflator, thereby reducing the manufacturing cost. It is also intended to make it easier.

To achieve the above objective,
The first invention is
An inflator filter for an airbag device having a hollow cylindrical filter member,
In addition, with a coil spring,
The coil spring includes a large-diameter portion wound around the outer peripheral surface of the filter member, a conical portion whose coil diameter is reduced from the large-diameter portion toward one end portion, and a small-diameter side of the conical portion. A cigarette,
It is characterized by having.

  As a result, the filter member and the coil spring are integrated, so that it is easy to reduce the assembly work of the airbag device to the inflator, and the gas generating agent is pressed by the coil spring in the inflator. In addition to preventing the gas generating agent from being crushed, reduce the number of parts compared to using a separate cushion member, etc., or easily prevent solids from being scattered during operation of the inflator Can do. Further, when assembling to the inflator, it is possible to easily improve workability by filling the gas generating agent from above the coil spring or between the wires of the conical portion.

The second invention is
An inflator filter for an airbag device according to a first invention,
The end winding part is provided with a plurality of turns or more.

The third invention is
A filter for an inflator of an airbag device according to a second invention,
The end winding portion has a cylindrical shape with a constant coil diameter, a conical shape with a larger diameter than the conical portion toward the end portion, an inverted conical shape with an increased diameter toward the end portion, or toward the end portion. It is characterized by being formed in a drum shape with a reduced diameter and an expanded diameter.

  Thus, it is possible to easily set the pressing force of the gas generating agent.

The fourth invention is:
An inflator filter for an airbag device according to any one of the first to third aspects,
The coil spring is characterized in that a tightly wound portion where the spring wire rods are in close contact with each other is formed from the large diameter portion to the conical portion.

  Thereby, the sealing performance between the upper end of the filter member and the lower surface of the housing can be easily improved.

  According to the present invention, it is possible to prevent the gas generating agent from being crushed in the housing, and to easily prevent solids from being scattered during operation of the inflator. In addition, the manufacturing cost can be easily reduced.

It is a front view which shows the structure of the filter of an inflator. It is a longitudinal cross-sectional view which shows the state of the assembly process of an inflator. It is a longitudinal cross-sectional view which shows the structure of an inflator. It is a front view which shows the modification of a coil spring. It is a front view which shows the other modification of a coil spring. It is a front view which shows the other modification of a coil spring.

  As an embodiment of the present invention, an example of a short cylindrical inflator will be described. Although this kind of inflator is used suitably for the airbag apparatus etc. of a motor vehicle, it is not limited to these.

(Configuration of the filter 100 constituting the inflator)
First, the filter 100 will be described with reference to FIG. The filter 100 includes a hollow cylindrical filter member 101 and a coil spring 102. The coil spring 102 is made of, for example, a piano wire having a wire diameter of about 1.0 to 2.0 mm, a steel hard wire, a spring stainless steel wire, and the like, and has a large diameter portion 102a wound around the outer peripheral surface of the filter member 101. , A conical portion 102b whose coil diameter is reduced from the large diameter portion 102a toward one end portion, and an end turn portion 102c on the small diameter side of the conical portion 102b.

  In order to securely attach the coil spring 102 to the filter member 101, it is preferable that the coil spring 102 has an inner diameter slightly smaller than the outer diameter of the filter member 101. For this purpose, for example, when low-temperature annealing (temper) is applied after winding the wire, the inner diameter is formed so as to be easily fitted into the filter member 101 by utilizing the characteristic that the diameter is reduced by releasing the residual stress. After the coil spring 102 is fitted into the filter member 101, it can be annealed at a low temperature so that strong adhesion can be obtained. Further, by utilizing the fact that the inner diameter increases when the coil spring 102 is compressed in the axial direction, the coil spring 102 is fitted into the filter member 101 in a compressed state and then stretched to be fixed to the filter member 101. Also good. Further, if the filter member 101 is inserted into the coil spring 102 while rotating in the direction opposite to the winding direction of the coil spring 102, the inner diameter is widened, so that the filter member 101 can be inserted relatively easily. The treatment of the end of the coil spring 102 may be a closed end, may be unground, or may be ground.

  Although it does not specifically limit as said filter member 101, For example, the hook metal plate by which the front-end | tip of the projection part was crushed and flattened is wound in a multilayer in the shape of a cylinder, or a metal plate is cut and expanded. Expanded metal with a mesh-like hole formed by being rolled, formed by winding a wire such as steel or pressed and cylindrically pressed and pressed, A material formed by compression molding a cylindrical knitted wire mesh, a material obtained by forming a wire into a cylindrical shape (for example, winding and knitting to form a cylindrical body), and hardening by sintering are used.

(Configuration of inflator 200, etc.)
As shown in FIGS. 2 and 3, the inflator 200 contains the filter 100 in housings 201 and 202, and is formed into a granular shape, a pellet shape, a columnar shape, a disk shape, or the like. The gas generating agent 205 is filled. More specifically, it includes a short cylindrical housing 201 having an open end, and a housing 202 that covers the opening of the housing 201, and the filter 100, the igniter 204, and the gas generating agent 205 are provided therein. It is configured. A gas discharge port 202a sealed with a seal 203 is formed on the peripheral wall of the housing 202, and the working gas generated, purified and cooled by the combustion of the gas generating agent 205 is jetted to the outside. For example, the gas generating agent 205 is compressed from above the coil spring 102 after the filter 100 is loaded in the housing 201, and then the coil spring 102 is compressed as the housing 202 is put on the housing 201. Thus, it is pressed toward the igniter 204.

  In the inflator 200 configured as described above, when the gas generating agent 205 is pressed by the coil spring 102, the gas generating agent 205 is prevented from being crushed. More specifically, since the end winding portion 102c at the end of the coil spring 102 is formed in a plurality of turns (for example, two or more turns), the end winding portion 102c enters the inner side of the filter member 101 during assembly and generates gas. The agent 205 can be easily pressed. Here, the load of the cushion can be easily adjusted by adjusting the wire diameter, the number of turns, the pitch (inter-wire gap), the free length, and the like of the coil spring 102. In addition, since the coil spring 102 is made of metal, it can be easily prevented from scattering due to the temperature and pressure during operation (chemical ignition). In addition, it becomes easier to manufacture at a lower cost than ceramic mats and silicon rubber.

  Further, since the large-diameter portion 102a of the coil spring 102 is wound around the outer periphery of the filter member 101, the filter member 101 can be coaxially (centered) with respect to the inner peripheral surfaces of the housings 201 and 202. Easy to do. Therefore, the high pressure gas can be efficiently fed into the inner peripheral portion of the housing 201. Moreover, the coil spring 102 prevents the high-pressure gas from expanding when the high-pressure gas passes through the filter member 101, and the gap between the outer peripheral surface of the filter member 101 and the inner peripheral surfaces of the housings 201 and 202. Therefore, it is easy to stably guide the high-pressure gas to the airbag. Moreover, since the outer diameter of the filter 100 is determined by the outer diameter of the coil spring 102, the accuracy of the outer diameter of the filter 100 can be easily increased as a result.

  Further, since the filter member 101 and the coil spring 102 are integrated as described above, the number of parts can be reduced and the assembling work can be easily reduced as compared with the case where a separate cushion member is used. become.

  In the state shown in FIG. 2, the gas generating agent 205 is placed from above the coil spring 102 or when the pitch of the spring wire is larger than the particle size of the gas generating agent 205 or can be easily increased. It can be easily filled from between the wires, and it is also easy to reduce the assembly man-hours.

(Modifications, etc.)
The shape of the end portion of the coil spring 102 is not limited to the end winding portion 102c having a constant coil diameter as described above. For example, as shown in FIGS. 4 to 6, an inverted cone that expands toward the end portion. The end winding portions 102d and 102e, the conical end winding portion 102f that has a diameter smaller than the conical portion toward the end, and the drum shape that decreases and expands toward the end. Etc. In addition, the pressing force of the gas generating agent 205 can be easily set by bringing the spring wire rods of the end winding portions into close contact with each other or leaving a space therebetween.

  Further, for example, the filter member 101 may be set to be partly tightly wound as necessary at the transition portion of the coil spring 102 from the large diameter portion 102a to the conical portion 102b, that is, near the upper end portion of the filter member 101. The sealing property between the upper end of the housing and the lower surface of the housing 202 can be improved. In order to further improve the sealing performance, a tapered inclined surface or a step may be formed on the inner surface of the upper end of the filter member 101.

DESCRIPTION OF SYMBOLS 100 Filter 101 Filter member 102 Coil spring 102a Large diameter part 102b Conical part 102c End winding part 102d End winding part 102e End winding part 102f End winding part 200 Inflator 201 Housing 202 Housing 202a Gas discharge port 203 Seal 204 Igniter 205 Gas generation Agent

Claims (8)

An inflator filter for an airbag device having a hollow cylindrical filter member,
In addition, with a coil spring,
The coil spring includes a large-diameter portion wound around the outer peripheral surface of the filter member, a conical portion whose coil diameter is reduced from the large-diameter portion toward one end portion, and a small-diameter side of the conical portion. A cigarette,
A filter for an inflator of an airbag device, comprising: An inflator filter for an airbag device according to claim 1,
A filter for an inflator of an airbag device, wherein the end turn part is provided with a plurality of turns or more. An inflator filter for an airbag device according to claim 2,
The end winding portion has a cylindrical shape with a constant coil diameter, a conical shape with a larger diameter than the conical portion toward the end portion, an inverted conical shape with an increased diameter toward the end portion, or toward the end portion. A filter for an inflator of an airbag device, wherein the filter is formed in a drum shape that has a reduced diameter and an increased diameter. An inflator filter for an airbag device according to any one of claims 1 to 3,
An inflator filter for an air bag apparatus, wherein the coil spring is a portion extending from the large-diameter portion to a conical portion, and a tightly wound portion where the spring wire materials are in close contact with each other is formed. A hollow cylindrical filter member;
A granular gas generating agent filled in the filter member;
An inflator for an airbag device including a coil spring,
The coil spring includes, in an uncompressed state, a large-diameter portion wound around the outer peripheral surface of the filter member, a conical portion whose coil diameter is reduced from the large-diameter portion toward one end, and the cone A small-diameter end winding portion of the shape portion,
An inflator for an airbag device, wherein the gas generating agent is configured to be pressed by a coil spring in which the end winding portion is pressed against the large diameter portion in an assembled state. An inflator for an airbag device according to claim 5,
In the inflator of an airbag apparatus, the coil spring is set so that a pitch of the spring wire rod of the conical portion is longer than a particle diameter of the gas generating agent in an uncompressed state. An inflator according to claim 5 or claim 6;
An air bag into which the working gas discharged from the inflator is introduced;
An airbag device comprising: A method of manufacturing an inflator for an airbag device according to claim 6,
In the non-compressed state, after the gas generating agent is filled in the space surrounded by the filter member and the conical portion of the coil spring, the end winding portion of the coil spring is pressed against the large diameter portion side. A method for manufacturing an inflator for an airbag apparatus, wherein the gas generating agent is pressed.

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