JP2001287613A - Side air bag device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To surely protect a head part without being unfavorably affected even when interference with a seat belt is generated in inflation development. SOLUTION: In this side air bag device 1 arranged in a side part of a seatback 2 to protect a breast and the head part of an occupant M against side-directional impact, a head part protecting portion 6 of an air bag 3 is formed into a top-closed cylindrical shape having a substantially constant cross section or changing gradually to be enlarged a little toward a portion corresponding to the head part and having no longitudinal-directional overhang part, and a gas flow deflecting means 8 for deflecting frontwards a straight gas flow from a base part 5 toward a tip part is provided in a side part having the possibility of interference with the seat belt of the protecting part 6.

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 protecting an occupant from the impact of a vehicle collision, and more particularly to a side airbag device for protecting the occupant's chest and head against an impact from the side. It is.

[0002]

2. Description of the Related Art A side airbag device for protecting the occupant's chest and head against impact from the side of a vehicle body is disclosed in, for example, Japanese Patent Application Laid-Open No. 8-273693. The inflator that blows out gas when necessary is housed in the housing, and is arranged on one side of the seat back, that is, one side behind the occupant sitting on the seat. As shown, the airbag 21 is inflated and deployed forward and upward from one upper side of the seat back 22 by the gas ejected from the inflator at the time of a side collision to protect each side of the occupant's chest and head. Is configured.

In the airbag 21 shown in FIG. 4, when the seat on which the occupant sits is adjusted rearward, when the airbag 21 is inflated and deployed, the rear portion is pulled out from the shoulder anchor 24 of the seat belt device. There is a problem that the airbag 23 may be swung forward as indicated by the imaginary line and may not be able to secure a sufficient protection area for the head.

[0004] To solve such a problem, for example, Japanese Patent Application Laid-Open Nos. Hei 9-123864 and Hei 10-28
For example, Japanese Patent Application Laid-Open No. 7195 discloses an airbag in which a portion that may interfere with a seat belt of an airbag is hollowed out and a head protection portion is extended rearward. Referring to FIG. 5, an example disclosed in the above-mentioned Japanese Patent Application Laid-Open No. 9-123864 will be described. In the illustrated example, the head is attached to the housing 25 so that there is no possibility of flipping an arm when the airbag is inflated and deployed. Protective airbag 26 and chest protective airbag 27
Are individually mounted, and the head protection airbag 26 is
As a whole, it is bulged upward with a slight inclination toward the front, and the rear part of the middle part is greatly hollowed out so as to avoid interference with the seat belt 23, and the upper part of the head protection part is large rearward. It is overhanging.

In such a configuration, when the inflator is actuated by a side impact, the gas ejected into the head protection airbag 26 first flows obliquely upward and upward as indicated by an arrow, and The direction of the protection part is changed from the front part to the rear part and flows into the rear part of the head protection part, and the head is protected in an inflated and deployed state in which interference with the seat belt 23 is avoided.
7 also expands and deploys forward to protect the chest.

[0006]

However, in the side airbag apparatus having the structure as shown in FIG. 5, when the head protection airbag 26 is inflated and deployed, the jetted gas is generated in front of the head protection part. After turning around and flowing to the rear,
There is a possibility that a delay may occur before the rear part of the head protection part is brought into the predetermined inflated state, and when the head protection airbag 26 is inflated and deployed, a protruding part behind the head protection part is attached to the seat belt 23. There is a risk of being caught, especially in that case, there is a high possibility that it will not be in the proper deployment state at the required timing, and there may be a case where the head protection is not sufficient, while conversely if it expands smoothly There is a problem that the gas flow collides with the rear part of the head protection part, and the head protection airbag deflects rearward due to its inertia force, which may cause a case where the head cannot be properly protected. .

SUMMARY OF THE INVENTION In view of the above-mentioned conventional problems, it is an object of the present invention to provide a side airbag device capable of reliably protecting a head without being adversely affected even when it interferes with a seat belt during inflation and deployment.

[0008]

SUMMARY OF THE INVENTION A side airbag device according to the present invention is a side airbag device disposed on a side portion of a seat back to protect an occupant's chest and head against impact from the side. The head protection portion of the airbag has a top-closed cylindrical shape that has a substantially constant cross section or gradually changes so as to become slightly larger toward a portion corresponding to the head, and has no overhanging portion in front and back. In addition, a gas flow deflecting means for deflecting a straight gas flow from the base to the front end toward the front is provided on a side portion of the head protection portion which may interfere with the seat belt.

Accordingly, even if the seat on which the occupant sits is adjusted rearward and the seat belt interferes with the rear part of the head protection part, the head protection part is cylindrical and the gas flow is straight, The deployment force above the protection part is large, and it smoothly deploys without being caught on the seat belt,
And when the seat belt interferes with the upper part of the gas flow deflecting means, it is easy to dent because the internal pressure of that part is relatively low,
Along with this, a rotational moment acting rearward acts on the upper part of the head protection part due to the inertia force of the gas flow, and the upper part of the head protection part falls backward to effectively protect the head.

Further, when the gas flow deflecting means is provided so as to be inclined in the direction along the gas flow from the direction perpendicular to the gas flow direction, the gas flow is hardly obstructed by the gas flow deflecting means, and the gas flow is smooth. The flow protects the head protection part quickly, and there is almost no rotational moment due to the gas flow that causes the upper part of the head protection part to oscillate. The head protection action when the seat is not adjusted rearward Is more stably obtained.

When the top of the head protection part is formed in a wedge shape, the possibility of the head protection part being caught on the seat belt when the head protection part is deployed can be reduced.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the side airbag device of the present invention will be described below with reference to FIGS.

In FIG. 1, reference numeral 1 denotes a side airbag device provided on a side portion of a seat back 2, and the airbag 3 is disposed in a housing 4 together with an inflator (not shown) in a folded state. I have. When the side airbag device 1 receives an impact from the side at the time of a side collision, gas is blown out from the inflator, and the airbag 3 is inflated and deployed forward and upward, and the occupant M's chest and head indicated by phantom lines. It is configured to protect the sides of the part.

The airbag 3 includes an occupant M sitting on a seat.
A base 5 at the rear of the shoulder or underarm, a head protection portion 6 that expands and expands substantially upward from the base 5 toward the side of the head of the occupant M, and a side of the chest of the occupant M from the base 5 And a chest protection portion 7 which expands and deploys substantially forward toward. The head protection portion 6 is formed in a top-closed cylindrical shape having a substantially constant cross section or gradually changing so as to become slightly larger toward a portion corresponding to the head, and having no overhang portion in the front and rear directions. The chest protection part 7 is formed in a substantially semi-elliptical shape from the base part 5 and is smoothly connected to the head protection part 6 in an arc shape.

The head protection portion 6 of the airbag 3 has a rear portion from the base 5 to the head protection portion 6 which may interfere with the seat belt when the head protection portion 6 is inflated and deployed. Gas flow deflecting means 8 for deflecting a straight gas flow toward the top toward the front is provided. Also,
The gas flow deflecting means 8 is provided at an angle θ in a direction along the gas flow from a direction perpendicular to the gas flow direction. Further, a wedge-shaped portion 9 that becomes thinner toward the tip is formed at the top of the head protection portion 6.

The gas flow deflecting means 8 is shown in FIG.
As shown in FIG. 2A, the cloths on both sides of the bag body of the airbag 3 are joined by sewing lines 8a, or as shown in FIG. FIG. 2 (c) shows a joint between the boundary portion of the bag and the bag body, or, as shown in FIG. 2 (c), a pick-up portion 8b is overlapped on the bag body and joined with a sewing line 8d from above. As shown in FIG. 2 (d), various modes can be applied as a specific configuration, such as forming a cut 8e in the bag body and connecting the edges with a sewing line 8f. The sewing lines 8a, 8c, 8d, 8
By forming the end of f into a loop, stress concentration can be avoided.

In the above configuration, when the inflator is actuated by a side impact, the blast gas inflates the head protection portion 6 and the chest protection portion 7 of the airbag 3 substantially upward and substantially forward from the base 5, respectively. Deploy. Therefore, there is no danger of the occupant M's arm jumping up, and both the head and chest of the occupant M are stably protected by the expanded head protection portion 6 and chest protection portion 7, respectively.

Further, the behavior of the airbag 3 according to the position of the seat on which the occupant M sits will be described in detail. The seat is adjusted forward and the seat belt hung on the shoulder anchor 10 of the seat belt device protects the head. In the case where no interference occurs at the rear part of the part 6, as shown in FIG.
Does not flow, the air flows straight in the direction indicated by the arrow 11 slightly deflected to the dashed arrow, and a sufficiently large upward force is generated above the head protection portion 6 so that the head protection portion 6 smoothly expands and expands upward,
Thereafter, the gas flows slightly backward as indicated by the arrow 12, causing a backward falling force. However, since the falling force is small, the head protection portion 6 maintains the almost expanded and deployed position and the head is Securely protected.

On the other hand, when the seat on which the occupant M sits is adjusted rearward and the seat belt interferes with the rear portion of the airbag 3, as shown in FIG. The gas flow direction is slightly inclined forward as indicated by an arrow 13 while being turned down, but the head protection part 6 is cylindrical and the gas flow is straight, so that the head protection part 6 is expanded upward. Since the force is large, the seat belt smoothly deploys without being caught by the seat belt, and the seat belt interferes with the upper part of the gas flow deflecting means 8, so that the internal pressure in that part is relatively low, so that the seat is easily dented. 3
As shown in (c), the inertia force of the gas flow exerts a rotational moment toward the rear as shown by an arrow 14 on the upper part of the head protection part 6, and the upper part of the head protection part 6 falls backward and the head Parts are effectively protected.

Further, since the gas flow deflecting means 8 is provided to be inclined by θ in the direction along the gas flow from the direction perpendicular to the gas flow direction, it is shown in FIGS. 3 (a) and 3 (b). When the head protection part 6 is inflated and deployed, the gas flow is hardly hindered by the gas flow deflecting means 8, and the head protection part 6 can be quickly deployed by the smooth gas flow. FIG.
At the time of the expansion and deployment of (a), the generation of the rotational moment due to the gas flow which causes the upper part of the head protection part 6 to sway can be almost eliminated, and the head protection action can be more stably obtained. Further, since the top of the head protection portion 6 is formed as the wedge-shaped portion 9, the possibility of being caught on the seat belt at the time of inflation and deployment in FIGS. 3A and 3B can be reduced, and the inflation and deployment can be performed reliably and smoothly. be able to.

[0021]

According to the side airbag device of the present invention, the head protection portion of the airbag is formed into a closed top cylindrical shape having no front and rear protrusions as described above.
Gas flow deflecting means for deflecting the straight gas flow from the base to the tip on the side of the head protection part that may interfere with the seat belt is provided. Even if the belt interferes, the gas flow is straight and the deployment force above the head protection part is large, so it smoothly deploys without being caught on the seat belt, and if the seat belt interferes with the upper part of the gas flow deflection means However, the gas pressure in that part is relatively low, so it is easy to dent, and the inertia of the gas flow causes a rotational moment to act on the upper part of the head protection part, and the upper part of the head protection part To protect the head reliably.

Further, if the gas flow deflecting means is provided so as to be inclined in a direction along the gas flow from a direction perpendicular to the gas flow direction, the gas flow is hardly obstructed by the gas flow deflecting means, so that the head is protected. Since the part is deployed quickly and there is almost no rotational moment due to gas flow, the upper part of the head protection part does not run out when the seat is not adjusted rearward, and the head protection function is more stable Is obtained.

Further, when the top portion of the head protection portion is formed in a wedge shape, the possibility that the head protection portion is caught on the seat belt when the head protection portion is deployed can be reduced.

[Brief description of the drawings]

FIG. 1 is a side view showing an inflated and deployed state of an airbag in one embodiment of a side airbag device of the present invention.

FIG. 2 is a side view showing various specific configuration examples of a gas flow deflecting unit in the embodiment.

FIG. 3 is a side view showing an inflated and deployed state of the airbag when a seat position is variously changed in the embodiment.

FIG. 4 is a side view showing an inflated and deployed state of an airbag in a conventional side airbag device.

FIG. 5 is a side view showing an inflated and deployed state of an airbag in another conventional side airbag device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Side airbag apparatus 2 Seatback 3 Airbag 6 Head protection part 8 Gas flow deflection means 9 Wedge-shaped part

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Haruo Fujita 2-1-1, Taoyuan, Ikeda-shi, Osaka Daihatsu Industry Co., Ltd. (72) Inventor Ikuo Yamada 1 Ochiai Ochiai, Kasuga-cho, Nishikasugai-gun, Aichi Prefecture Inside Toyoda Gosei Co., Ltd. (72) Inventor Yoshio Mizuno Aichi Prefecture, Kasuga-cho, Nishi-Kasugai-gun, Aichi Ochiai, Nagahata 1 Toyoda Gosei Co., Ltd. Co., Ltd. F-term (reference) 3D054 AA07 AA21 CC08 CC11 CC34 EE20 FF16

Claims (3)

[Claims] 1. A side airbag device disposed on a side portion of a seat back to protect an occupant's chest and head against an impact from a side, wherein a head protection portion of the airbag is provided.
The cross section gradually changes so as to be almost constant or slightly larger toward the part corresponding to the head, and it has a top-closed cylindrical shape with no front and rear protrusions, and interferes with the seat belt of the head protection part A side airbag device characterized in that a gas flow deflecting means for deflecting a straight gas flow from a base portion to a front end toward a front side is provided on a possible side portion. 2. The side airbag device according to claim 1, wherein the gas flow deflecting means is provided to be inclined in a direction along the gas flow from a direction perpendicular to the gas flow direction. 3. The side airbag device according to claim 1, wherein a top portion of the head protection portion has a wedge shape.