JPH09249090A - Air bag device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To approximately uniformly ensure the expansion state, where the air bag is thinly spread at the initial stage of expansion and thereafter thickness is increased, of an air bag. SOLUTION: An air bag device 10 comprises an air bag 11 in a folded bag- form state in a case 25 in the shape of a cylinder with a bottom having an opening part 25a and constraining a passenger during expansion; an inflator 15 to guide gas N for expansion in the air bag 11; and a diffuser 18 to guide the gas N for expansion for the inflator 15 in the air bag 11. The diffuser 18 is formed of a material having rigidity and formed such that gas flow pipe parts 20 and 20 are disposed. The gas flow pipe parts 20 and 20 guide the gas N for expansion from the vicinity of the central part of the interior of the case 25 in the direction of the peripheral edge 26c of a case opening and causes inflow of the gas for expansion in the air bag 11 in a direction crossing a line L, interconnecting the air bag device 10 and a passenger, approximately at right angles.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an airbag device capable of restraining an occupant in a vehicle at a predetermined time, and more particularly to a diffuser for restricting a flow of inflation gas from an inflator for inflating the airbag. The present invention relates to an improved airbag device.

[0002]

2. Description of the Related Art Conventionally, in an air bag device, in order to regulate the flow of gas for inflating an air bag discharged from an inflator so that the air bag can be inflated smoothly, a gas inlet of the inflator and the air bag is provided. A diffuser having a predetermined gas flow hole was disposed between the two.

This diffuser is disclosed in Japanese Patent Laid-Open No. 5-
As described in Japanese Patent No. 262195, there has been one configured as an inner bag arranged in an airbag. This inner bag was configured as a flexible strip or bag.

Further, as the function of the diffuser, when the airbag is inflated, the airbag inflates in a direction substantially orthogonal to a line connecting the airbag device and the occupant at an initial stage, and thereafter, the airbag device and the occupant are separated from each other. Restricting the flow of inflation gas so that the thickness of the airbag increases along the connecting line and transitions to an inflated shape, that is, it expands thinly at the time of initial inflation and then thickens afterwards. Is desirable.

[0005]

However, in the inner bag as disclosed in the above publication, since the material itself has flexibility, even if the gas circulation hole is arranged at a predetermined position,
Since the inner bag also expands when the airbag expands,
The position of the gas flow holes also changes variously, and the flow of the inflation gas becomes unstable, making it difficult to obtain a uniform inflation state (a series of shapes from the initial inflation to the completion of inflation) in many airbags. It was

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems and provides an airbag device capable of ensuring a substantially uniform inflated state of an airbag that spreads thinly at the beginning of inflation and then thickens. To aim.

[0007]

SUMMARY OF THE INVENTION An airbag device according to the present invention comprises a bottomed cylindrical case having an opening, and an airbag capable of restraining an occupant when inflated as a folded bag shape. An airbag device configured by arranging an inflator for supplying an inflation gas to the airbag and a diffuser for guiding the inflation gas from the inflator into the airbag, wherein the diffuser is rigid. Is formed from a material having, and is fixed in the case, the inflating gas is guided from the vicinity of the center in the case to the case opening peripheral direction, and the airbag device and the occupant. And a gas flow pipe portion that allows the gas to flow into the airbag in a direction substantially orthogonal to a line connecting the two.

[0008]

In the airbag device according to the present invention, when the inflation gas is discharged from the inflator, the inflation gas flows into the airbag through the gas flow pipe portion of the diffuser.

At this time, the gas distribution pipe portion supplies the expansion gas with
Guide from the center of the case toward the edge of the case opening,
Moreover, since the air bag is made to flow into the air bag in a direction substantially orthogonal to the line connecting the air bag device and the occupant, the air bag folded and stored in the case initially spreads thinly from the peripheral edge of the case opening. After that, the shape becomes an expansion completed shape with an increased thickness as the inflow amount of the expansion gas increases.

Since the diffuser, including the gas flow pipe portion that guides the inflation gas, has rigidity, the gas flow pipe portion does not deform from the initial stage of inflation of the airbag to the completion of inflation, and a large number of air flows. Even in the bag, the substantially same inflated state can be secured.

Therefore, in the airbag device according to the present invention, it is possible to ensure a substantially uniform inflated state of the airbag that spreads thinly at the initial stage of inflation and then thickens.

[0012]

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

The airbag device 10 of the embodiment is shown in FIG.
As shown in FIG. 3, the airbag 11 and the inflator 1 are those for a passenger seat provided in a portion of an instrument panel (hereinafter abbreviated as instrument panel) 1 in front of the passenger seat.
5, the diffuser 18, and the case 25 are provided.

The air bag 11 is attached to the case 25 and is folded and housed in the case 25 in the shape of a substantially rectangular tube having a gas inlet 11a. To attach the airbag 11 to the case 25,
A square annular retainer 12 having a plurality of bolts 12a protruding downward is used. That is, the retainer 12
Is arranged on the inner peripheral edge of the gas inlet 11a of the airbag 11, and each bolt 12a is inserted into a mounting hole (not shown) provided on the peripheral edge of the gas inlet 11a. The airbag 11 is attached to the case 25 by inserting it into the attachment hole (not shown) of the wall 26a and fixing the nut 13.

The inflator 15 is a cylindrical main body 1
5a, a flange portion 15c provided on one end side of the main body portion 15a, and a male screw portion 15d provided on the other end side of the main body portion 15a. The body portion 15a is formed with a predetermined number of gas discharge ports 15b for discharging the gas N for inflating the airbag 11 when the inflator 15 is operated. The inflator 15 is assembled to the case 25 by inserting the male screw portion 15d into a large diameter through hole 27c provided in a side wall 27b of the case 25, which will be described later, and projecting the male screw portion 15d from the small diameter through hole 27d. The flange portion 15c is brought into contact with the peripheral edge of the through hole 27c, and the nut 16 is screwed into the male screw portion 15d.

The diffuser 18 is formed by welding a plurality of rigid steel pipes, and the inflator 15
A cylindrical mounting portion 19 that covers the main body portion 15a of the
It is composed of two substantially cylindrical gas flow pipe parts 20 connected to the peripheral edge of the opening 19a provided at the upper part of the gas passage 9. To attach the diffuser 18 to the case 25,
The inner diameter allows the inflator body 15a to be inserted,
The outer diameter is smaller than the inflator flange 15c,
Moreover, an annular spacer 23 having an L-shaped cross section that can be fitted to both ends of the mounting portion 19 is used. The spacer 23 is fitted to both ends of the mounting portion 19 and the mounting portion 19 is housed in the case 25. If the inflator 15 is inserted into the spacers 23 and the mounting portion 19 and attached to the case 25,
The diffuser 18 can be attached and fixed to the case 25 so that both ends of the attachment portion 19 are sandwiched between the side walls 27b of the case 25.

When the diffuser 18 is attached to the case 25, the expansion gas N is supplied from the vicinity of the center of the case 25 to the peripheral edge 26c of the case opening portion when the diffuser 18 is attached to the case 25. In the direction of
In addition, it is formed so that it can flow into the airbag 11 in a direction substantially orthogonal to the line L connecting the airbag device 10 and the occupant M. Therefore, in the gas flow path R of the expansion gas N discharged from the inflator 15, the expansion gas N passes through the opening 19a from the inside of the mounting portion 19 and the two gas flow pipe portions 20.
-It branches into 20 and becomes a flow path which flows toward the case opening peripheral edge 26c. In the case of the embodiment, the gas flow pipes 20, 20 are oriented substantially in the left-right direction of the vehicle.

The case 25 is made of sheet metal in a shape in which two large and small rectangular parallelepiped bodies each having an airbag storage portion 26 and an inflator storage portion 27 are stacked in two stages.

The airbag accommodating portion 26 has a quadrangular frame-shaped step wall 26a arranged at the bottom for fixing the retainer 12 to the nut 13, and a quadrangular cylindrical side wall 26b extending from the entire outer peripheral edge of the step wall 26a. It is configured with. The opening 25a of the case 25 is arranged on the inner peripheral side of the end of the side wall 26b, and the opening 25a is covered by the door 4 of the instrument panel 1.

The door 4 is provided with a U-shaped notch 2 when viewed from above at a predetermined position of the instrument panel 1, and
A thin hinge portion 3 is arranged in the instrument panel 1 so as to connect both ends of the notch 2 and is formed inside the notch 2. Then, the door 4 is pushed by the inflating airbag 11 and opens with the hinge portion 3 as the center of rotation.

The inflator accommodating portion 27 has a rectangular plate-shaped bottom wall 27a, and a rectangular tubular side wall 27b connected from the entire outer peripheral edge of the bottom wall 27a to the inner peripheral side of the step wall 26a.
And is composed of At a predetermined position on the side wall 27b,
Large and small through holes 27c that penetrate the inflator 15
27d are formed.

A bracket 28 is fixedly attached to the lower surface of the bottom wall 27a as shown in FIG.
The airbag device 10 is arranged below the door 4 portion of the instrument panel 1 by fastening bolts and nuts (not shown) to the reinforcing member 5 extending from a frame (not shown) of the vehicle.

The assembly of the airbag device 10 of this embodiment will be described. First, the spacers 23 are fitted to house the diffuser 18 in the case 25, and the nut 16 is used to carry out the assembly as described above. The inflator 15 and the diffuser 18 are attached and fixed to the case 25.

Further, each bolt 12a is connected to the gas inlet 11a.
The retainer 12 is arranged in the airbag 11 by penetrating a predetermined mounting hole in the peripheral edge, and the airbag 11 is folded in this state.

Then, each bolt 12a is inserted into a mounting hole (not shown) of the step wall 26a, and the nut 13 is fixed,
If the folded airbag 11 is stored in the airbag storage portion 26, the airbag device 10 can be assembled, and if the bracket 28 is connected to the reinforcing member 5, the airbag device 10 can be mounted on the vehicle. .

When the inflator 15 is actuated and the expansion gas N is discharged from the gas discharge port 15b after mounting on the vehicle, the expansion gas N is supplied to the mounting portion 1 of the diffuser 18.
From inside 9 through the opening 19a, two gas flow pipe portions 20.
It branches into 20, flows in the gas flow path R toward the case opening peripheral edge 26c, and flows into the airbag 11.

Therefore, the folded airbag 11
When opening the door 4 and projecting from the case opening 25a, as shown by the chain double-dashed line in FIGS.
It is projected from the case opening 25a while expanding so as to spread thinly in the substantially left-right direction of the vehicle at c.

Then, as the flow rate of the inflation gas N flowing into the airbag 11 increases, the thickness of the airbag 11 increases, and the inflation completed shape is obtained as shown by the three-dot chain line in FIG.

Therefore, the airbag device 1 according to the embodiment.
At 0, it is possible to secure the inflated state of the airbag 11 that spreads thinly at the initial stage of inflation and becomes thicker thereafter. Then, the diffuser 18 that regulates the flow of the expansion gas N
However, since it has rigidity and is fixed to the case 25, the gas flow pipe portions 20 and 20 thereof are not deformed from the initial expansion to the completion of expansion, and can maintain a stable gas flow path R. it can. Therefore, even if a large number of airbag devices 10 are operated, it is possible to secure a substantially uniform inflated state of the airbag 11.

In the embodiment, the diffuser 18
As an example, the one having the gas flow pipes 20 forcibly flowing the expansion gas N in the substantially left-right direction of the vehicle has been exemplified.
As in the diffuser 38 shown in FIG. 4, in addition to the gas flow pipe portions 20 and 20, the gas flow pipe portions 21 and 21 are provided in the mounting portion 19 in a direction substantially orthogonal to the gas flow pipe portions 20 and 20. Is also good. Of course, these gas distribution pipe parts 21, 21
Also, the direction from the opening (not shown) of the attachment portion 19 to the tip end guides the inflation gas N from the vicinity of the center of the case 25 toward the case opening peripheral edge 26c and connects the airbag device and the occupant. It is set so that it can flow into the airbag in a substantially orthogonal direction.

By the way, in the top-mounted airbag device 10 as in the embodiment as the airbag device provided in the passenger seat, the airbag 11 is moved in the left-right direction at the initial stage of inflation in consideration of interference with the windshield G. The diffuser 18 of the embodiment is provided so as to be thinly spread.
It is desirable to use the air bag 11 in a mid-mount or low-mount air bag device at the initial stage of inflation.
4 so that it spreads out thinly in the left-right and up-down cross directions.
It is desirable to use the diffuser 38 of.

Further, in the embodiment, the diffuser 18
38 shows a case where a plurality of steel pipes are manufactured by welding, but the diffuser has rigidity that does not deform between the initial stage of inflation of the airbag and the completion of inflation, and the inflation gas is directed in a predetermined direction. It suffices if it can be guided, and for example, it may be configured as the diffuser 48 shown in FIG. The diffuser 48 is provided in the gas distribution pipe portion 5
1a and a sheet metal member 51 having a predetermined shape having mounting portion portions 51b and 51b arranged on both sides of the gas flow pipe portion portion 51a are used. To form the gas flow pipe portions 50, 50, and further, the mounting portion portions 51a, 51a are fixed to the clamp 5
2 and 52 are used, and the spacers 23 and 23 are interposed and wound around the main body 15a of the inflator 15 to form the mounting portion 49.

Further, as the diffuser, not only the diffuser covering the entire circumference of the inflator 15 but also the case 2
Step wall 26 so as to cover the inflator housing 27 of No. 5
The diffuser may be formed by providing a flat plate-shaped mounting portion fixed to a and the gas flow pipe portions 20 and 20 fixed to the mounting portion.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a mode of use of an embodiment of the present invention, which corresponds to a II section in FIG.

FIG. 2 is a perspective view showing a diffuser used in the same embodiment.

FIG. 3 is a schematic view showing the airbag of the same embodiment when inflated.

FIG. 4 is a perspective view of a diffuser of another embodiment.

FIG. 5 is a perspective view of a diffuser according to still another embodiment.

[Explanation of symbols]

 10 ... Airbag device, 11 ... Airbag, 15 ... Inflator, 18.38.48 ... Diffuser, 20.21.50 ... Gas distribution pipe part, 25 ... Case, 25a ... Opening part, 26c ... Opening part periphery, N ... inflation gas, M ... occupant, L ... line.

Claims (1)

[Claims] 1. An air bag, which is a folded bag-like shape and is capable of restraining an occupant when inflated, in a bottomed cylindrical case having an opening, and an inflator for supplying inflation gas to the airbag. A diffuser for guiding inflation gas from the inflator into the airbag, and an airbag device, wherein the diffuser is formed of a material having rigidity and is provided in the case. While being fixed, the inflating gas is guided from the vicinity of the center of the case to the peripheral direction of the case opening, and in the airbag in a direction substantially orthogonal to a line connecting the airbag device and the occupant. An air bag device, wherein the air bag device is formed by including a gas flow pipe part through which the gas flows.