JP2000318558A - Air bag device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an air bag device having a cover opened sufficiently fast, even if pressed with low pressing force by an inflated air bag. SOLUTION: This air bag device has a retainer 10, an inflator 20, an air bag and a module cover 40. The module cover 40 is formed by combining a plurality of cover pieces 41. Each cover piece 41 is L-shaped, having a sector front face part 42 opposed to an occupant, and a side face part 43 erected from the circular arc shaped peripheral edge of the front face part 42. The module cover 40 is fixed to the retainer 10 by a metal or synthetic resin tape band 50 surrounding the outside of the side face parts 43 of the respective cover pieces 41. A thin sheet (cloth) is stuck so as to cover the module cover 40.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an airbag device for a driver's seat installed on a steering wheel of an automobile.

[0002]

2. Description of the Related Art An airbag device for a driver's seat includes a retainer, an inflator attached to the retainer, an airbag inflated by gas from the inflator,
A cover that covers the airbag, and is attached to the center of the steering wheel. When a vehicle encounters an emergency such as a collision, the inflator is activated and the airbag is inflated. At this time, the cover covering the airbag device is opened, the airbag spreads in the vehicle interior, and the driver is prevented from colliding with the steering wheel or the like.

[0003] A conventional cover is integrally formed of a synthetic resin, and a reinforcing member such as a mesh may be embedded therein.

[0004]

In the conventional airbag apparatus, when the airbag is inflated, the airbag presses the cover to rupture the airbag, and the inflator is required to cleave the cover. Those that generate gas at a pressure are used.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an airbag device having a cover which opens sufficiently quickly even when pressed by a low pressing force by an inflating airbag.

[0006]

An airbag device according to the present invention has a retainer, an inflator attached to the retainer, an airbag inflated by gas from the inflator, and a cover for covering the airbag. . The cover is a combination of a plurality of cover pieces, and the base end of each cover piece is attached to a retainer.

In such an airbag device, the cover is a combination of a plurality of cover pieces, and the cover is opened when the cover piece is deformed when the airbag is inflated. Therefore, the cover opens sufficiently quickly even if the force of the airbag pressing the cover is low.

In the present invention, each cover piece has a front surface facing the occupant, and a side surface rising from the front surface. The front surface is substantially fan-shaped, and the side surface is a retainer. It is preferably attached to further,
It is preferable that a convex portion is provided on one side edge of the front portion and a concave portion is provided on the other side edge, and the convex portion and the concave portion of the adjacent cover piece are preferably engaged with each other.

In the present invention, it is preferable that the retainer has a substantially circular shape or a polygonal shape not less than a quadrangle.

A cover piece having a side surface curved in a substantially arc shape can be fitted to a substantially circular retainer. By forming the fan shape of the front part of the cover piece into a shape obtained by equally dividing a circle into a plurality, a cover is configured by combining a plurality of cover pieces having the same shape.

When the retainer has a polygonal shape, the side surface of the cover piece preferably has a width substantially equal to the length of one side of the polygonal shape.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. 1 is a perspective view of an airbag device for a driver's seat according to an embodiment, FIG. 2 is a sectional view of the airbag device of FIG. 1, and FIG. 3 is a perspective view of a cover piece. In FIG. 1, the illustration of the sheet (cloth) is omitted.

This airbag device includes a retainer 10,
It has an inflator 20, an airbag 30, and a module cover 40. The retainer 10 has a circular main surface 1.
1, an annular upright wall 12 rising from the periphery of the main surface portion 11, a convex portion 13 projecting outward from the tip of the upright wall 12, and an inflator insertion port 14 provided at the center of the upright wall 12. The tip side of the inflator 20 is inserted into the inflator insertion opening 14. A flange 21 of the inflator 20 is in contact with a peripheral edge of the inflator insertion port 14.

A gas inlet at the rear end of the airbag 30 is overlapped with a portion around the inflator insertion opening 14 of the retainer 10. Ring 25 with stud bolt 22
The peripheral edge of the gas inlet is sandwiched between the gas inlet and the peripheral edge of the inflator insertion port 14 of the retainer 10. Retainer 10
The inflator 20 and the airbag 30 are fixed to the retainer 10 by tightening a nut 23 into a bolt 22 inserted into a bolt insertion hole provided in each of the flanges 21.

The module cover 40 is formed by combining a plurality of (eight in this embodiment) cover pieces 41. Each cover piece 41 has an L-shape having a fan-shaped front part 42 facing the occupant and a side part 43 erected from the arc-shaped periphery of the front part 42.
The side surface portion 43 is curved in an arc shape. A convex portion 44 protrudes from the inner surface of the side surface portion 43, and a convex portion 45 protrudes from the outer surface of the side surface portion 43.

A protruding portion 46 protrudes from one of the two sides extending in the radial direction of the front portion 42, and a concave portion 47 having the same shape and the same size as the protruding portion 46 is provided on the other side. Is provided.

A module cover 40 formed by combining the cover pieces 41 is mounted on the retainer 10 so as to cover the airbag 30. Side part 4 of cover piece 41
3 is arranged along the outer surface of the upright wall 12, and the projection 44 of the cover piece 41 and the projection 13 of the upright wall 12 engage.

A side surface 4 of each cover piece 41 is formed by a metal or synthetic resin tape band 50 as a binding linear body surrounding the outside of the side surface 43 of each cover piece 41.
By tightening 3, the module cover 40 is fixed to the retainer 10.

A thin sheet (cloth in this embodiment) 60 is attached so as to cover the module cover 40.

In the airbag device for the driver's seat configured as described above, when the inflator 20 performs a gas ejection operation, the airbag 30 expands and presses the cover piece 41. As a result, the front portion 42 opens in a flap shape, and the airbag 30 inflates between the steering wheel and the occupant. When the front part 42 opens, the cloth 60 tears.

In this airbag device, since the front surface of each cover piece 41 of the module cover 40 is deformed to open the module cover 40, the pressure with which the airbag 30 presses the module cover 40 is low. Also the module cover 40 opens fast enough. Therefore, an inflator 20 having a low generated gas pressure can be employed.

The cloth 60 is torn smoothly when pressed by the front part 42. A perforated slit may be provided in the cloth 60 in order to promote the front part 42 to be torn. As the cloth 60, a cloth piece obtained by sewing a cross piece having the same size as the cover piece 41 may be used. As the suture thread, a thread having a strength to be torn when the front part 42 is opened may be adopted.

As the sheet, paper or a synthetic resin sheet can be used in addition to cloth.

In the above embodiment, the retainer 10 is circular, but may be a polygon including a square. If this polygon is a regular polygon, it is sufficient to produce only one type of cover piece. For example, in the case of a regular octagonal retainer, the apex angle of the front part is 45 as a cover piece.
The one having the triangle front surface of ゜ is used. In the case of a regular hexagonal retainer, the apex angle of the front part is 6 as the cover piece.
One having a 0 ° triangular front surface is used.

In the present invention, the cover pieces may be bonded to each other with an adhesive having a relatively low bonding strength.

[0026]

As described above, in the airbag apparatus of the present invention, the cover opens sufficiently quickly even when the inflation pressure of the airbag is low. Therefore, it is possible to adopt an inflator having a low gas generation pressure.

[Brief description of the drawings]

FIG. 1 is a perspective view of a driver seat airbag device according to an embodiment.

FIG. 2 is a cross-sectional view of the airbag device of FIG.

FIG. 3 is a perspective view of a cover piece.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Retainer 11 Main surface part 12 Standing wall 20 Inflator 30 Airbag 40 Module cover 41 Cover piece 42 Front part 43 Side part 50 Tape band 60 Cloth (sheet)

Claims (8)

[Claims] 1. An airbag device for a driver's seat comprising: a retainer; an inflator attached to the retainer; an airbag inflated by gas from the inflator; and a cover covering the airbag. An airbag device for a driver's seat, wherein a plurality of cover pieces are combined, and a base end side of each cover piece is attached to a retainer. 2. The method according to claim 1, wherein each cover piece is
An airbag device comprising: a front portion facing an occupant; and a side portion rising from the front portion, wherein the front portion is substantially fan-shaped, and the side portion is attached to a retainer. . 3. The airbag device according to claim 2, wherein the retainer has a substantially circular shape, and a side portion of the cover piece is curved in a substantially arc shape along the outer periphery of the retainer. 4. The airbag device according to claim 2, wherein the retainer has a polygonal shape of a quadrangle or more. 5. The retainer according to claim 2, wherein the retainer has a main surface portion and an upright wall rising from a peripheral edge of the main surface portion. An airbag device, wherein the airbag device is superimposed on an outer surface of a piece, and a side portion of each cover piece is fixed to the upright wall by a binding linear member that goes around the upright wall. 6. The cover piece according to claim 2, wherein a convex portion is provided on one side edge of the front surface portion of the cover piece, and a concave portion is provided on the other side edge. An airbag device, wherein a convex portion and a concave portion are engaged with each other. 7. The airbag device according to claim 1, wherein a sheet is attached to an outer surface of a cover formed by combining cover pieces. 8. A cover piece for an airbag device having a fan-shaped front portion and a side portion rising from the front portion.