JPH09136605A - Housing of inflator for air bag - Google Patents

Abstract

PROBLEM TO BE SOLVED: To facilitate highly accurate drilling of an injection hole by providing an opening in the peripheral wall of a housing and an injection hole in a metal plate fixed to the peripheral wall so as to seal the opening. SOLUTION: Two square widow holes 27 are provided in a housing main body 1 and a perforated plate 11 having a number of injection holes is fixed to the inner circumferential surface of the housing main body 1 so as to seal these window holes 27. The perforated plate 11 is formed by drilling a metal plate made of an aluminum alloy by pressing or the like and then performing press molding so as to adhere the plate to the inner circumferential surface of the housing main body 1 and to provide the plate with a prescribed curvature. In this perforated plate 11, injection holes 4a circular in the center part of a peripheral direction are arrayed in an axial direction and in both sides of these injection holes 4a, circular injection holes 4b long in the peripheral direction are arrayed in the axial direction. This perforated plate 11 is positioned in the inner circumferential surface of the housing main body 1 by a pair of projections 28 formed in the axial direction.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inflator housing for deploying and inflating an airbag.

[0002]

2. Description of the Related Art In an air bag device provided in a vehicle compartment to protect an occupant's body from a shock at the time of a vehicle collision, in order to rapidly expand and inflate a folded and stored bag-shaped air bag, there is a deflagration. An inflator in which a high-pressure gas is obtained by burning a volatile gas generating agent is often used (see Japanese Patent Application Laid-Open No. 4-293643).

The housing of such an inflator is provided with a large number of small-sized fumaroles so that the combustion gas generated therein can be smoothly supplied to the inside of the airbag. Since these fumaroles have a great influence on the internal pressure that influences the burning rate of the gas generating agent and the flow rate of the burning gas, their size, shape and number are appropriately set in consideration of these circumstances. .

[0004]

By the way, the housing is generally formed in a tubular shape. However, since a large number of fumaroles to be opened have a small diameter, a sheet material preliminarily perforated is wound into a tubular shape. However, even if a cylindrical material formed by extrusion molding or the like is perforated, there is a disadvantage that the manufacturing process becomes extremely troublesome when trying to ensure a predetermined perforation accuracy. It was In particular, when the peripheral wall to be perforated has a curved surface such as a cylindrical housing, complicated and precise perforation equipment is required, and the demand for manufacturing cost reduction cannot be satisfied.

The present invention has been devised in order to eliminate such disadvantages of the prior art, and its main purpose is to make it possible to facilitate highly accurate drilling of the fumaroles. An object is to provide a housing of an inflator for an airbag.

[0006]

According to the present invention, such an object is to provide an air bag provided with an insufflation hole for ejecting a high-pressure gas generated by combustion of a gas generating agent loaded therein. A housing of an inflator, wherein an opening is formed in a peripheral wall of the housing, and the fumarole is formed in a plate member fixed to the peripheral wall so as to close the opening. Is achieved by providing.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The structure of the present invention will be described in detail below with reference to the embodiments shown in the accompanying drawings.

1 and 2 show a basic embodiment of a housing of an airbag inflator constructed according to the present invention. In this housing, two rectangular window holes 27 of the same size are formed side by side in the axial direction on the peripheral wall of the cylindrical housing body 1, and a perforated plate 11 having a large number of fumaroles 4 is formed inside the housing body 1. The window hole 27 is closed by being fixed to the peripheral surface, and the high-pressure combustion gas generated by the combustion of the gas generating agent loaded inside is ejected from the fumarole 4 in approximately one direction. ing.

The porous plate 11 has a sheet-like flat material
Circular fumaroles 4 at the portions corresponding to the two window holes 27, respectively.
Are opened by a press or the like and then bent into a predetermined curvature by press molding or the like so as to be in close contact with the inner peripheral surface of the housing body 1, and the outer peripheral edge of the perforated plate 11 and the housing body 1 The opening edge of the window hole 27 is joined to each other by brazing, welding or the like.

As shown in FIGS. 3 and 4, a pair of window holes may be provided at axially symmetrical positions of the housing body 1. In this case, the combustion gas is dispersed and ejected in two opposite directions. Also in this case, each window 2
A pair of perforated plates 11a
11b are respectively fixed to the inner peripheral surface of the housing body 1.

The porous plate 11 may be joined to the outer surface of the housing body 1.

Further, the perforated plate 1 with respect to the housing body 1
In order to facilitate the positioning of the housing 1, a pair of protrusions may be provided on the circumferential surface of the housing body 1 in the axial direction so as to abut against the side edge of the porous plate 11. In addition, the perforated plate 11 can be appropriately positioned even if a stepped portion that receives the outer peripheral edge of the perforated plate 11 is provided in the opening edge portion of the window hole 27 or a tapered surface is formed. it can. Alternatively, a pair of grooves may be formed in the circumferential surface of the housing body 1 in which the side edge portions of the perforated plate 11 fit, and the perforated plate 11 may be fitted and attached from the end portion of the housing body 1. .

Further, the cross-sectional contour of the housing body 1 is
The shape is not limited to the true circle, but may be, for example, an elliptical shape, an oval shape, a square shape, a triangular shape, or the like, and an optimum cross-sectional shape can be appropriately adopted depending on a portion where the vehicle interior is arranged. Then, if the window hole 27 is opened in the plane formed by forming the housing body 1 in an oval or rectangular shape, the perforated plate 11
Since the flat plate can also be a flat plate, bending of the porous plate 11 can be omitted.

[0014]

FIG. 5 to FIG. 7 show a specific embodiment of an airbag inflator to which the present invention is applied. This inflator comprises a housing body 1 formed into an elliptic cylindrical shape by extrusion molding of an aluminum alloy material, a perforated plate 11 accommodated in the housing body 1 side by side in the minor axis direction, a partition 9, and an ignition tube. And the leg assembly 12, the filter assembly 13 fixed to the outer surface of the housing body 1, the bottom plate 3 fixed to one opening end surface of the housing body 1, and the other opening end surface of the housing body 1 with screws. And a cover plate 14 that

The partition body 9 has a large size 2 inside the housing body 1.
It is for partitioning into one combustion chamber and is formed separately from the housing body 1. The ignition tube and leg assembly 12 is formed by integrally forming the ignition tube 2 and the leg portion 7 that supports the ignition tube 2. The partition 9 and the ignition tube and leg assembly 12 are made by subjecting a plate material made of an aluminum alloy to predetermined hole processing and then bending the plate material into a predetermined shape by roll forming or the like.

The filter assembly 13 is for preventing the scattering of the residual solid matter generated by the combustion of the gas generating agent and the exposure of the flame. The filter assembly 13 has two strips extending in the axial direction on the outer peripheral surface of the housing body 1. The ribs 15 are fixed in a fitted state. In addition, the filter assembly 13
A rib 16 having the same shape as these ribs 15 is formed in the center of the surface opposite to the surface on which the ribs are provided. A screw hole 18 into which a screw 17 for fixing the lid plate 14 is screwed is formed at one end of each of the three ribs 15 and 16.

The lid plate 14 is formed in a shape substantially identical to the cross-sectional contour of the housing body 1, and has a center through which a stud bolt 19 inserted into an end portion of the ignition tube portion of the ignition tube and leg assembly 12 is inserted. A hole 20 is formed in the center of the hole, and three ear pieces 22 having screw insertion holes 21 are provided at positions corresponding to the ribs 15 and 16 of the housing body 1. A gasket 23 having the same shape as the lid 14 is sandwiched between the lid 14 and the housing body 1.

Stud bolts 19 protruding from the cover plate 14
At the tip of the
This stud bolt 1
The inflator can be attached to the inside of the airbag (not shown) through the boss 9 and the boss 26 provided on the outer surface of the bottom plate 3. The stud bolt 19 and the hole 20 of the lid plate 14 through which the stud bolt 19 is inserted are not necessary depending on the mounting manner in the airbag.

As shown in FIGS. 6 and 7, the housing body 1 is provided with two rectangular window holes 27, and a large number of fumarole holes 4 are provided so as to close the window holes 27. The perforated plate 11 is fixed to the inner peripheral surface of the housing body 1.

The perforated plate 11 is formed by punching a plate material made of an aluminum alloy by a press or the like, and then bending it to a predetermined curvature by press molding so as to be in close contact with the inner peripheral surface of the housing body 1. . Circular fumaroles 4a are axially arranged in the circumferential center of the perforated plate 11, and oblong fumaroles 4b elongated in the circumferential direction are axially arranged on both sides of the fumarole 4a. It is set up. The perforated plate 11 is positioned by a pair of protrusions 28 formed on the inner peripheral surface of the housing body 1 in the axial direction.

The partition 9 is composed of an arc-shaped plate portion 9a that is in close contact with the inner surface of the porous plate 11, and side plate portions 9b having a hook-shaped cross section that hangs down from the left and right ends thereof. In the arc-shaped plate portion 9a, circular holes 29 of substantially the same size as the circular fumaroles 4a of the perforated plate 11 are axially arranged in a row. In the left and right side plate portions 9b, communication holes 10 that open toward both sides of the ignition tube portion are arranged in a line in the axial direction.

The ignition tube and leg assembly 12 is formed by integrally forming an ignition tube 2 bent in a circular tube shape and a leg portion 7 supporting the ignition tube 2. In this ignition tube 2, small holes 6 opened between the left and right side plate portions 9b of the partition body 9 are arranged in a line in the axial direction, and an igniter connected to this ignition tube 2 is connected to the collision detection sensor. When actuated in response to an electrical or mechanical signal, the ignition flash spouts simultaneously from the small holes 6 and ignites the gas generating agent around it.

The leg portion 7 extends outward in the radial direction from the joint of the ignition tube 2 bent in a circular tube shape, and has a flange 30 projecting from the free end thereof on opposite sides. There is. The flange 30 is fitted between a pair of protrusions 31 formed on the inner surface of the housing body 1 in the axial direction, and the ignition tube and the leg assembly 12 are positioned.

The filter assembly 13 is composed of a filter material 32 formed by superposing a plurality of kinds of wire mesh and a frame material 33 for holding the wire mesh, and is curved so as to be in close contact with the outer peripheral surface of the housing body 1. ing. The frame material 33 is joined to the filter material 32 by bending a plate material made of aluminum alloy by a press or the like so as to hold the outer peripheral portion of the filter material 32 and then bending the hole material. The frame member 33 has four square holes 34 corresponding to the circular fumaroles 4a of the perforated plate 11 and four oblong fumes 4b.
There are 12 rows in total.

The bottom plate 3 has the same shape as the cover plate 14, and a boss 26 is projectingly provided on the outer surface thereof. And this boss 26
An igniter (not shown) is fitted in the center hole of the igniter, and a circular hole 35 aligned with the inner space of the igniter tube 2 is formed in the central part of the bottom plate 3 so that the igniter part of the igniter can be exposed inside the igniter tube 2. It is opened in.

The perforated plate 11, the partition 9, the ignition tube and leg assembly 12, and the frame member 3 of the filter assembly.
A brazing sheet in which a brazing material is previously adhered (clad) on both sides or one side is adopted as a plate material made of an aluminum alloy which is a material of each member of 3 and the bottom plate 3.
Therefore, the perforated plate 11, the partition body 9, and the ignition tube and leg assembly 12 which are formed into a predetermined shape are inserted into the housing body 1 and the stud bolts 19 are inserted into the ignition tube 2 to insert the filter assembly 13 and the bottom plate. When 3 is positioned and placed in a heating furnace, the brazing material is melted and the members are brazed to each other and integrated. Then, an igniter is attached to the boss 26 of the bottom plate 3, a gas generating agent is loaded into the combustion chamber 8, and the lid plate 14 and the gasket 23 are screwed to complete the inflator. If necessary, an ignition agent is loaded inside the ignition tube 2.

[0027]

As described above, in the present invention, only one or a small number of large-diameter window holes are opened in the housing to reduce the troublesome boring of the closed cross-section member,
On the other hand, a perforated plate having a large number of small holes to be fumaroles is separately formed and then fixed to a housing to be integrated. Since this perforated plate is a plate material, precise perforation processing is easy, and even if the perforated plate is curved, if it is perforated in a flat plate state and then bent into a predetermined shape. It can be easily manufactured. Therefore, the manufacturing of the housing is facilitated as a whole, and there is a great effect in reducing the manufacturing cost.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a basic embodiment of a housing of an airbag inflator constructed according to the present invention.

FIG. 2 is a cross-sectional view showing the housing shown in FIG. 1 by cutting it in a direction orthogonal to an axis.

FIG. 3 is a perspective view showing a modified embodiment of a housing of an airbag inflator constructed according to the present invention.

FIG. 4 is a cross-sectional view showing the housing shown in FIG. 3 in a direction orthogonal to the axis.

FIG. 5 is a perspective view showing an inflator to which the present invention is applied.

6 is an exploded perspective view of the inflator shown in FIG.

7 is a cross-sectional view of the inflator shown in FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Housing body 2 Ignition tube 3 Bottom plate 4 Fume hole 6 Small hole 7 Leg part 9 Partition body 10 Communication hole 11 Perforated plate 12 Ignition pipe and leg assembly 13 Filter assembly 14 Lid plate 15 Rib (2 pieces) 16 Rib (1 17 screw 18 screw hole 19 stud bolt 20 center hole 21 screw hole 22 ear piece 23 gasket 24 seat nut 25 lock nut 26 boss 27 window hole 28 ridge 29 circular hole 30 flange 31 ridge 32 filter material 33 frame material 34 Square hole 35 Circular hole

Claims (1)

[Claims] 1. A housing of an inflator for an air bag, comprising an insufflation hole for ejecting high-pressure gas generated by combustion of a gas generating agent loaded inside, the opening being opened in a peripheral wall of the housing. A housing for an inflator for an air bag, characterized in that the fumarole is formed in a plate member fixed to the peripheral wall so as to close the opening.