Airbag and occupant restraint device

Abstract

An airbag includes: a first inflatable section that is inflated and deployed forward from the upper portion of a seat back through the left side of a head of an occupant; a second inflatable section that is inflated and deployed forward from the upper portion of the seat back through the right side of the head of the occupant; and a third inflatable section that is continuous with lower portions of front portions of the first inflatable section and the second inflatable section and that is inflated and deployed in front of the chest of the occupant. The front portions of the first and second inflatable sections extend in directions intersecting the vehicle front-rear direction so as to be closer to each other toward the front side. The front portions meet each other at a front end of the airbag.

Claims

1. An airbag that is inflated and deployed from a seat back, a head rest, or an interior member behind the seat back of an automobile seat and that restrains an occupant of the seat, the airbag comprising first and second inflatable sections that are inflated and deployed on both sides of the head of the occupant, and a third inflatable section that is inflated and deployed in front of the chest of the occupant, an upper portion of the third inflatable section being continuous with front portions of the first and second inflatable sections, wherein occupant-facing surfaces of the front portions of the first inflatable section and the second inflatable section, the occupant-facing surfaces facing the occupant, extend in directions intersecting a vehicle front-rear direction; the occupant-facing surfaces of the front portions of the first inflatable section and the second inflatable section and a virtual line, which connects intermediate portions of the occupant-facing surfaces and is parallel to a vehicle width direction, form a triangular shape in plan view, and a main portion of a rear surface of the third inflatable section is flat.

2. The airbag according to claim 1, wherein the first inflatable section and the second inflatable section have intermediate portions between rear ends and the front portions, and, the intermediate portions have such a vertical section in a vehicle width direction that a width of a lower portion is larger than a width of an upper portion.

3. An occupant restraint device comprising the airbag according to claim 1 and an inflator for inflating the airbag.

4. An occupant restraint device comprising the airbag according to claim 2 and an inflator for inflating the airbag.

Description

BRIEF DESCRIPTION OF DRAWINGS

(1) FIG. 1 is a plan view of an inflated airbag according to an embodiment.

(2) FIG. 2 is a side view of the inflated airbag according to the embodiment.

(3) FIG. 3 is a sectional view taken along line III-III in FIG. 1.

(4) FIG. 4 is a sectional view taken along line IV-IV in FIG. 2.

(5) FIG. 5 is a sectional view taken along line V-V in FIGS. 1 and 2.

(6) FIG. 6 is a sectional view taken along line VI-VI in FIG. 5.

(7) FIG. 7 illustrates an end face of a section taken along line VII-VII in FIG. 1.

DESCRIPTION OF EMBODIMENTS

(8) Referring to FIGS. 1 to 6, an airbag and an occupant restraint device according to an embodiment will be described. In the description below, the front and rear and the left and right correspond to the front and rear and the left and right of an automobile.

(9) An airbag 1 includes: a first inflatable section 10 that is inflated and deployed forward from the upper portion of a seat back S through the left side of a head H of an occupant P; a second inflatable section 20 that is inflated and deployed forward from the upper portion of the seat back S through the right side of the head H of the occupant P; and a third inflatable section 30 that is continuous with lower portions of front portions 10f and 20f of the first inflatable section 10 and the second inflatable section 20 and that is inflated and deployed in front of the chest of the occupant P.

(10) Occupant-facing surfaces of the front portions 10f and 20f of the first and second inflatable sections 10 and 20 and a virtual line connecting between intermediate portions of the occupant-facing surfaces of the front portions 10f and 20f and parallel to the vehicle width direction form a triangular shape in plan view (FIG. 1). The ends of the triangle may be rounded. In other words, the occupant-facing surfaces of the front portions 10f and 20f of the first and second inflatable sections 10 and 20 form a V shape in plan view (FIG. 1).

(11) The first inflatable section 10 and the second inflatable section 20 includes rear ends 10e and 20e, front portions 10f and 20f, and intermediate portions 10m and 20m between the rear ends 10e and 20e and the front portions 10f and 20f. The intermediate portions 10m and 20m extend in the vehicle front-rear direction. The intermediate portions 10m and 20m are substantially parallel to each other.

(12) The front portions 10f and 20f extend in directions intersecting the vehicle front-rear direction so as to be closer to each other toward the front side. The front portions 10f and 20f meet each other at a front end if of the airbag 1.

(13) The first inflatable section 10 and the second inflatable section 20 include first surfaces 11 and 21 facing the occupant head H, and second surfaces 12 and 22 facing away from the occupant. The first inflatable section 10 and the second inflatable section 20 further have bottom surfaces 13 and 23 in the intermediate portions 10m and 20m.

(14) The first surfaces 11 and 21 and the second surfaces 12 and 22 are closer to each other toward the top and meet each other at the upper end to form top edges 10t and 20t. In the intermediate portions 10m and 20m, the top edges 10t and 20t are located in the middle of the first inflatable section 10 and the second inflatable section 20 in the left-right direction. As shown in FIG. 5, in a vertical section in the vehicle width direction, the intermediate portions 10m and 20m have a substantially isosceles triangle shape, in which the width of the lower portion is larger than the width of the upper portion.

(15) In plan view (FIG. 1), the top edges 10t and 20t of the front portions 10f and 20f are closer to the outer circumference of the airbag 1 toward the front side. The first surfaces 11 and 21 of the front portions 10f and 20f are inclined so as to be higher at portions farther from the occupant head H.

(16) The first surfaces 11 and 21 of the first inflatable section 10 and the second inflatable section 20 meet at the front portion of the airbag 1, and this meeting portion serves as a valley edge 1v extending in the front-rear direction.

(17) The third inflatable section 30 has a rear surface 31 on the occupant side and a front surface 32 on the non-occupant side, that is, on the front side. The rear surface 31 and the front surface 32 meet at the left edge, right edge, and the lower edge of the third inflatable section 30. The upper portion of the rear surface 31 is continuous with the lower portions of the first surfaces 11 and 21 of the front portions 10f and 20f. The upper portion of the front surface 32 is continuous with the lower portions of the second surfaces 12 and 22 of the front portions 10f and 20f.

(18) The third inflatable section 30 is provided with a tether (not shown) for maintaining its inflation thickness (that is, the distance between the rear surface 31 and the front surface 32) at a predetermined distance, whereby a main portion (other than the side edge portions and the lower edge portion) of the rear surface 31 becomes flat at an inflated state.

(19) A vent hole (not shown) is provided in the airbag 1.

(20) Ends of gas introducing pipes (not shown) are inserted into the rear portions of the first inflatable section 10 and the second inflatable section 20.

(21) The thus-configured airbag 1 is folded and stored in a retainer (not shown). An inflator is installed in the retainer, so that gas can be introduced into the airbag 1 through the gas introducing pipes.

(22) The retainer accommodating the airbag 1 is installed in the upper portion of the seat back S and is covered by a seat-back covering material. The seat-back covering material has tearable slits (not shown) that can be torn when the airbag 1 is inflated.

(23) When a collision, overturning, or the like of an automobile is detected, the inflator is actuated, and the airbag 1 starts to be inflated. The airbag 1 pushes and breaks the tearable slits and is inflated and deployed first upward from the upper portion of the seat back S. Next, the first and second inflatable sections 10 and 20 are inflated and deployed forward above the occupant head H, and then the third inflatable section 30 is inflated and deployed downward in front of the occupant head H. At the same time, or before or after that, the first and second inflatable sections 10 and 20 descend to the sides of the head H.

(24) The final deployed shape of the airbag 1 is shown in FIGS. 1 to 7. The third inflatable section 30 of the airbag 1 in this final deployed shape is located in front of the chest of the occupant P. Because the main portion of the rear surface 31 of the third inflatable section 30 is a flat surface facing the occupant chest, the contact area with the chest is large, and thus, the load is distributed. The first and second inflatable sections 10 and 20 extend on the left and right sides of the occupant head H and connect between the third inflatable section 30 and the upper portion of the seat back S. In this embodiment, the front portions 10f and 20f of the first and second inflatable sections 10 and 20 are located obliquely in front of the occupant head H, on the left and right sides.

(25) When the automobile experiences a forward collision, the head H of the occupant P is restrained by the front portions 10f and 20f near the valley edge 1v, and the chest is restrained by the third inflatable section 30.

(26) When the automobile experiences an offset collision or an oblique collision, the occupant head H is restrained by the front portion 10f or 20f, and the chest is restrained by the third inflatable section 30. This way, even in the case where the automobile experiences an offset collision or an oblique collision, the occupant head H is restrained by the single airbag 1. In an offset collision or an oblique collision, the occupant head moves obliquely forward. Because the front portions 10f and 20f extend in directions intersecting the vehicle front-rear direction, the occupant head H is restrained by the front portion 10f or 20f so as to substantially directly face the front portion 10f or 20f.

(27) The above-described embodiment is an example of the present invention, and the present invention may be implemented in a way other than illustrated. For example, although the airbag 1 does not have an overhead inflatable section that covers the upper side of the occupant head H, such an inflatable section may be provided. Furthermore, in the present invention, the airbag may be installed so as to be inflated and deployed from an interior member behind the seat back.