JPH07186874A - Structure of combustion ring for gas generator for air bag - Google Patents

Abstract

PURPOSE:To effectively collect combustion residues by means of a coolant by a method wherein a combustion ring is provided with a plurality of peripherally extending protrusion parts, each protrusion part is provided with a ceiling part inclined based on the peripheral wall surface of the combustion ring, and an opening through which gas is injected is formed in the end on one side of the protrusion part. CONSTITUTION:A generating high pressure high temperature flame passes through an opening 7 and is caused to ignite a gas generating agent in a combustion chamber 5. Gas generated in the combustion chamber 5 is collided with an inclining ceiling part by which the direction of a flow is changed, and the change of the flow causes dissipation of a part of energy. The energy is peripherally injected through an opening 21b in the end on one side of the protrusion part and rotational movement is exerted on the gas. Combustion gas is axially and radially outwardly diffused as it is rotated around a combustion ring 20. A comparatively large combustion residue contained in gas is radially outwardly transferred by means of a centrifugal force generated by rotation and effectively collected by means of a coolant 13.

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 for protecting an occupant from an impact, and more particularly to a structure of a combustor ring thereof.

[0002]

Combustion rings are disposed within the housing of a gas generator and define a combustion chamber. In the conventional gas generator, a through hole is formed in the combustion ring, and combustion gas is ejected from the through hole in the radial direction and collides with the immediately preceding coolant before reaching the filter. As the gas is cooled in the coolant, a relatively large combustion residue is collected, the remaining residue is removed by the filter, and the cooled / purified gas is ejected from the opening of the housing.

[0003]

In the conventional collision type gas generator described above, the combustion gas is blown out in the radial direction through the through hole of the combustion ring, so that the gas collides unevenly near the through hole. Therefore, it is difficult to effectively collect the combustion residue with the coolant.

Therefore, it is an object of the present invention to provide a novel combustion ring structure that solves the problems of the prior art.

[0005]

A structure of a combustion ring in an air bag gas generator according to the present invention includes a housing, a combustion ring disposed in the housing and defining a combustion chamber, and the housing and the air bag. In a gas generator having an opening communicating with each other, the gas generated in the combustion chamber by an impact is introduced into the airbag to protect an occupant from the impact, the combustion ring,
The peripheral wall portion is provided with a plurality of protrusions formed so as to protrude radially outward and extending in the circumferential direction, each protrusion having a ceiling portion inclined with respect to the peripheral wall surface of the conversion ring, and one end side of the protrusions. Is characterized by having an opening for ejecting gas.

Further, in the conversion ring, the openings of the adjacent protrusions can face each other.

The combustion ring of the present invention comprises a plurality of projections each having a circumferential wall portion formed to project radially outward and extending in the circumferential direction. Each of these protrusions has a ceiling portion that is inclined with respect to the peripheral wall surface of the combustion ring, and has an opening for ejecting gas at one end side of the protrusion portion.

The combustion ring defines a combustion chamber,
A gas generating agent is filled in the combustion chamber. Combustion of the gas generating agent generates high-temperature, high-pressure combustion gas in the combustion chamber, and this gas is ejected in the radial direction from the combustion chamber. The ejected gas collides with the inner surface of the rib-shaped protrusion in the circumferential direction, and the flow direction is changed by the ceiling portion inclined with respect to the peripheral wall surface of the commutation ring, thereby causing a part of energy loss. The combustion gas whose flow direction is changed by the ceiling portion is jetted in the circumferential direction from the one end side opening of the projection portion, and the gas is given a rotational motion. The combustion gas diffuses axially and radially outward while rotating around the combustion ring. The gas that diffuses while rotating spreads over the entire area of the coolant that surrounds the combustion ring, and the combustion gas is effectively cooled by the coolant.

Further, the relatively large combustion residue contained in the gas is moved to the outside in the radial direction by the centrifugal force due to the rotation and is effectively collected by the coolant.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a half sectional view of a gas generator provided with the present combustion ring. The housing of the gas generator includes a diffuser shell 1 and a closure shell 3 that forms a cavity 2 together with the diffuser shell 1.
Consists of. The diffuser shell 1 has a circular portion 1b and a peripheral wall portion 1c formed on the outer peripheral portion of the circular portion 1b, and a central cylindrical body 1d is formed concentrically with the peripheral wall portion 1c at the central portion of the circular portion 1b. ing. The closure shell 3 has a circular portion 3a and joints 3c and 3d formed at predetermined positions on the circular portion 3a. The joint portions 3c and 3d are formed at positions facing the peripheral wall portions of the diffuser shell 1, and are joined to the tips of the peripheral wall portions.

The inside of the space 2 is delimited in the circumferential direction by the central cylindrical body 1d and the convection ring 20.
An ignition device housing chamber 4 is formed inside d. Further, the conversion ring 2 is provided outside the central cylindrical body 1d.
0 are arranged concentrically to form a combustion chamber 5 around the central cylindrical body 1d. Further, a coolant / filter chamber 19 is formed surrounding the combustion chamber 5.

The conversion ring 20 includes a peripheral wall portion 20.
a includes a plurality of protrusions 21 that are formed so as to project radially outward and extend in the circumferential direction. These protrusions 21 are shown in FIG.
As shown in FIG. 5, a plurality (eight in this embodiment) are provided at equal intervals in the circumferential direction. As shown in FIG. 3, each of these protrusions has a semi-conical shape as a whole and includes a ceiling portion 21a that is inclined with respect to the peripheral wall surface 20b of the conversion ring. Further, an opening 21b for ejecting gas is provided at one end of the protrusion 21. These protrusions can be formed by pressing.

An igniter 11 and a transfer charge 6 are contained in the ignition device accommodating chamber 4, a gas generating agent (not shown) is filled in the combustion chamber 5, and a coolant / filter chamber 19 is further provided in the coolant / filter chamber 19. Coolant 1 surrounding the combustion ring 20
3 is provided, and the filter 12 is provided so as to overlap the coolant 13 in the radial direction.

An opening 7 for transmitting the flame of the transfer charge 6 to the combustion chamber 5 is provided between the ignition device housing chamber 4 and the combustion chamber 5, and a coolant / filter chamber 19 and an air bag (not shown). In between, a plurality of outlets 10 for introducing the gas that has passed through the coolant 13 and the filter 12 are provided at predetermined intervals in the circumferential direction at the base of the peripheral wall 1c of the diffuser shell.

When a sensor (not shown) is activated by the impact, the igniter 11 is ignited, and the transfer charge 6 is ignited. The high-pressure, high-temperature flame generated thereby passes through the opening 7 and ignites the gas generating agent in the combustion chamber 5. The gas generated in the combustion chamber 5 collides with the sloping ceiling portion 21a, and the flow direction is changed, whereby a part of the energy is lost and the gas is ejected from the one end side opening 21b of the protrusion in the circumferential direction. The gas is given a rotational motion. The combustion gas diffuses axially and radially outward while rotating around the combustion ring 20. The gas that diffuses while rotating spreads over a wide area of the coolant 13 that surrounds the combustion ring, and also passes through a wide area of the filter 12 to reach the outlet 10. The combustion gas is thus effectively cooled and purified by the coolant and the filter.

Further, a relatively large combustion residue contained in the gas is moved to the outside in the radial direction by the centrifugal force due to the rotation and effectively collected by the coolant 13.

It is also possible to roughen the wall surface of the combustion ring by, for example, sandblasting, thereby collecting the combustion residues rotating around the combustion ring to further improve the collection efficiency.

FIG. 4 shows a structure of a conversion ring in which openings of adjacent protrusions face each other. The gases ejected from the openings 21b collide with each other, whereby a significant deceleration of the gas flow velocity is achieved, and as a result, a large loss of gas energy can be achieved.

FIG. 5 shows an example in which the present combustion ring is attached to a gas generator in which a coolant and a filter are arranged so as to overlap each other in the axial direction. In this case, retainer 4
A gap flow path 41 is formed between the inner end surface of the filter 0 and the outer peripheral surface of the combustion ring 20.
The gas is introduced from the inner end surface of 2. Opening 2
The gas ejected from 1b in the circumferential direction diffuses outward in the axial direction and the radial direction while rotating around the combustion ring 20 and passes through a wide area of the coolant 33 and the filter 32 to reach the exhaust port 37.

[0021]

According to the present invention, since the combustion gas is ejected in the circumferential direction, the combustion residue can be effectively collected by the coolant by utilizing the centrifugal force.

Further, according to this structure, since the combustion gas ejected in the circumferential direction diffuses outward in the axial direction and the radial direction while rotating, it can pass through a wide area of the coolant and the filter, whereby the coolant, The filter can be effectively used.

[Brief description of drawings]

FIG. 1 is a half cross-sectional view of a gas generator including the present combustion ring.

FIG. 2 is a plan view of the present conversion ring.

FIG. 3 is a perspective view of a protrusion of the present conversion ring.

FIG. 4 is a plan view of another embodiment of the present conversion ring.

FIG. 5 is a partial cross-sectional view showing an example in which the present combustion ring is attached to a gas generator in which a coolant and a filter are arranged so as to overlap each other in the axial direction.

[Explanation of symbols]

 1 Diffuser Shell 3 Closure Shell 5 Combustion Chamber 10 Discharge Port 12 Filter 13 Coolant 20 Combination Ring 20a Peripheral Wall 20b Peripheral Wall 21 Projection 21a Ceiling 21b Opening

Claims (2)

[Claims] 1. A gas having a housing, a combustion ring disposed in the housing to define a combustion chamber, and an opening for communicating the housing with the airbag, and a gas generated in the combustion chamber due to impact is released into the airbag. In the gas generator which is introduced into the interior to protect an occupant from an impact, the combustion ring includes a plurality of protrusions formed so that a peripheral wall portion protrudes outward in the radial direction and extending in the peripheral direction, and each of the protrusions is A structure of a combustion ring in an air bag gas generator, comprising: a ceiling portion that is inclined with respect to a peripheral wall surface of the combustion ring; and an opening for ejecting gas on one end side of the protrusion. 2. The structure of a combustion ring in a gas generator for an air bag according to claim 1, wherein openings of adjacent protrusions face each other.