JP2003341461A - Side air bag device for vehicular seat - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve force concentration on a rupture starting portion of a sewn line by suppressing the elongation of a power cloth although the power cloth has a greater width on the side of the sewn line subject to rupture. <P>SOLUTION: The side air bag device comprises an air bag 32 set large enough to inflate and develop almost al over the side of a seatback 12 in the vertical direction. The rupture region of the sewn line 22 on the seat cover 20 is expanded in accordance with the larger size of the air bag 32. The power cloth 40 for concentrating the force on a portion, where the rupture of the sewn line 22 is started, is set to have a short joint edge 42 to be joined to a frame of the seatback 12 and a long rectangular sewed edge 44 to be sewed along the sewn line 22 at the opposite side. The power cloth 40 is cut in the state that at least one of two sides connecting the each other corresponding ends of the joint edge 42 and the sewed edge 44 matching to the direction of warps or wefts of a woven cloth. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a side airbag device for a vehicle seat, and more particularly to a side airbag for a vehicle seat that is set to a size that allows the airbag to inflate and deploy over substantially the entire area of the seat back side in the vertical direction. It relates to a bag device.

[0002]

2. Description of the Related Art Conventionally, as a side airbag device for a vehicle seat, for example, a technique disclosed in Japanese Patent Application Laid-Open No. 9-123860 is known. In this technique, the airbag is housed in an airbag case built in the side of the seat back, and the outward opening of the airbag case is closed with a sackcloth. One end of this webbing is fixed to the airbag case, and the other end of the tapered shape is sewn together with a sewn portion for breaking in the seat cover. With this structure, the inflation pressure of the airbag is concentrated on the sewn portion through the webbing, and the sewn portion is quickly broken.

As is apparent from the technique disclosed in this publication, the webbing exerts a function of concentrating the force at the breaking start portion of the sewing line which is supposed to be broken by the inflation of the airbag. That is, the stretch of the seat cover at the rupture start portion is suppressed by the force cloth, and the rupture of the sewing line is immediately started. Therefore, if the sash cloth stretches, its function cannot be sufficiently fulfilled. Therefore, the woven cloth has the direction of the warp or weft of the woven cloth aligned with the direction of receiving the force due to the inflation of the airbag.

FIG. 4 is a schematic view of a vehicle seat equipped with a general side airbag device. The phantom line in this drawing indicates a state in which the airbag 132 of the side airbag device is inflated and deployed. The airbag 132 has a predetermined sewing line 122 on the seat cover of the seat back 12.
Rupture and expand. Airbag 13 of this size
The width of the webbing 140 is also set to be small because the breakage area of the sewing line 122 required for unfolding 2 is relatively short. However, if the size of the airbag 132 is increased as will be described later in order to enhance the function of the side airbag device, it is necessary to expand the fracture region of the sewing line 122 accordingly. With the expansion of the rupture region, at least the width of the webbing 140 on the sewing line 122 side must be set large.

[0005]

The overall shape of the stilt cloth whose width on the sewing line side is increased due to the increase in size of the airbag has a trapezoidal shape. As a result, the direction in which the sack cloth receives a force may coincide with the bias direction of the woven cloth, and the sack cloth is likely to stretch and cannot serve its original purpose. The present invention is intended to solve the above-mentioned problems, and its purpose is to start the breaking of the sewing line by suppressing its elongation, even though it is a sash cloth having a large width on the side of the sewing line where the breaking is planned. It is to increase the concentration of power on the part.

[0006]

SUMMARY OF THE INVENTION The present invention is to achieve the above object. According to a first aspect of the present invention, an airbag built in a seat back has a predetermined seat cover according to its inflation pressure. A side airbag device that breaks at a sewing line and inflates and deploys, and is set to a size that allows the airbag to inflate and deploy over substantially the entire area in the vertical direction on the side of the seat back. The rupture region of the sewing line is expanded based on the increase in size of the airbag. The webbing for concentrating the force at the point where the rupture of the sewing line is started has a short connecting edge that is connected to the frame of the seat back, and a sewn edge that is sewn along the sewing line on the opposite side. Is set to a long rectangular shape. Moreover, the woven cloth is a woven cloth, and at least one of the two sides connecting the corresponding ends of the connecting edge and the suture edge is cut in accordance with the warp or weft direction of the woven cloth. There is. In this way, the sewn edges of the sewn cloth are lengthened along with the expansion of the rupture area of the sewing line in the seat cover, but the sewn line of the sewn cloth when the sewing line is ruptured by the inflation pressure of the airbag is Growth is suppressed. Therefore, it is possible to effectively concentrate the force on the breaking start portion of the sewing line, and to inflate and deploy the airbag quickly.

The invention according to claim 2 is the side airbag device for a vehicle seat according to claim 1,
In the webbing, the longer side of the two sides connecting the corresponding ends of the connecting edge and the suture edge is aligned with the direction of the warp or weft of the woven fabric. As a result, when the sewing line of the seat cover is broken, it is possible to apply a force to a portion that is farthest from the connecting edge of the webbing and is less likely to be stressed by the inflation pressure of the airbag.

The invention described in claim 3 is the invention according to claim 1 or 2.
In the vehicle seat side airbag device described in (4), the connecting edge of the webbing is set to have substantially the same length as the connecting edge of the webbing used for the small side airbag. In this case, in the frame of the seat back, the structure can be used as it is without changing the structure of the part where the connecting edge of the webbing is connected.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below. FIG. 1 is a schematic view of a vehicle seat provided with a side airbag device, and FIG. 2 is an enlarged sectional view taken along the line AA of FIG. As shown in FIG. 1, the vehicle seat includes a seat cushion 10 and a seat back 12. When the side airbag device operates, the airbag 32 inflates and deploys as shown by the phantom line in FIG. The airbag 32 in the deployed state is set to a size capable of protecting almost the entire area in the vertical direction on the side of the seat back 12.

As shown in FIG. 2, in the structure of the seat back 12, the seat pad 16 is located outside the seat frame 14, and the seat cover 20 is located outside the seat pad 16.
Is covered with. The back surface of the seat pad 16 is supported by the pad support member 15. Also seat back 12
The backboard 18 forming the back surface of the backboard 18 has a structure in which the surface of the base material 18a is covered with the skin material 18b.

At the side portion inside the seat back 12,
An airbag unit 30 of a side airbag device is incorporated in a storage space 16a for the airbag, which is formed between the seat frame 14 and the seat pad 16. The airbag unit 30 has an inflator 34 housed in an airbag 32.
4 generates an operating pressure based on a signal from an impact sensor (not shown), which causes the airbag 32 to inflate.

The seat pad 16 is provided with a breakage promoting portion 16b which is continuous with the air bag storage space 16a and extends toward the outside of the seat back 12. The breakage promoting portion 16b promotes breakage of the seat pad 16 due to the inflation pressure of the airbag 32 and deploys the airbag 32. Then, the seat cover 20 includes the breakage promoting portion 16b.
The sewing line 22 located at the extension point of is made to break more easily than the other sewing lines. This sewing line 2
The fracture region in the direction along the second seam (vertical direction in FIG. 1) is expanded as the airbag 32 is enlarged.
The sewing line 22 uses a sewing thread having a count or strength that is easier to break than the sewing threads used for other sewing lines.

A power cloth 40 is provided inside the seat cover 20, and the power cloth 40 is used for concentrating the force on a portion of the sewing line 22 at which breakage starts. Strength cloth 40
Is made up of two sheets of webbing 40A, 40B separated at the sewing line 22 of the seat cover 20.
These webbings 40A and 40B each have a trapezoidal shape as shown in FIG. Of the two vertical edges of the webbing 40A, 40B, the shorter connecting edge 42 is connected to the seat frame 14, and the longer sewing edge 44 is sewn to the seat cover 20 along the sewing line 22.

As shown in FIG. 2, the connecting edges 42 of the webbings 40A and 40B are sewn to the connecting plates 46 and 47, respectively. And the individual coupling plates 46, 47
Are joined to the back surface of the seat frame 14 by bolts and nuts 48 in a state of being overlapped with each other. On the other hand, the sewn edges 44 of the webbings 40A and 40B are sewn together with the seat cover 20 at the sewing line 22.
That is, the one webbing 40A is stretched between the connecting plate 47 and the sewing line 22 in a state of following the outer surface of the seat pad 16. The other power cloth 40B
Is stretched between the connecting plate 47 and the sewing line 22 through a slit 16c formed across the front side and the back side of the seat pad 16.

The individual connecting edges 42 of the webbings 40A, 40B are set to almost the same size as the webbing 140 shown in FIG. On the other hand, the sewn edge 44 is set to be long so as to correspond to the rupture region of the sewing line 22 that is expanded as the airbag 32 becomes larger. Therefore, the connecting structure of the webbings 40A and 40B to the seat frame 14 may be the same as in the case of FIG.
The structure of 4 or the coupling plates 46 and 47 can be used as they are.

FIG. 3 is a schematic view showing the shape of the webbing 40A (or webbing 40B). As shown in this drawing, the webbing 40A is obtained by cutting the woven fabric 41 into a trapezoid (rectangle). Assuming that the corners of the webbing 40A are a to d, the sides ab correspond to the connecting edges 42, and the sides cd correspond to the suture edges 44. Then, of the two sides ac and bd connecting the corresponding ends of the connecting edge 42 and the suture edge 44, the longer side b-d is aligned with the direction of the warp (or weft) of the woven fabric 41. ing. Further, the sides a to c are also set so as not to coincide with the bias direction of the woven fabric 41 shown by the phantom line in FIG. 3 as much as possible.

In this way, the webbing 40A (or the webbing 40
By setting the shape of B), although the sewn edge 44 is lengthened in response to the expansion of the rupture region of the sewing line 22, the expansion of the webbing 40A due to the inflation pressure of the airbag 32 is suppressed. To be Particularly long side b-d
The point d is a portion where it is difficult to apply stress to the inflation pressure of the airbag 32, but by aligning this side b-d with the warp direction of the woven fabric 41, the force can be efficiently applied to the point d. Therefore, it is possible to properly perform the role of the power cloth 40 (power cloth 40A, 40B), that is, the function of concentrating the force on the portion of the sewing line 22 at which the rupture starts to quickly inflate and deploy the airbag 32.

[Brief description of drawings]

FIG. 1 is a schematic view of a vehicle seat equipped with a side airbag device.

FIG. 2 is an enlarged sectional view taken along the line AA of FIG.

FIG. 3 is a schematic diagram showing the shape of a sash cloth.

FIG. 4 is a schematic view of a vehicle seat equipped with a general side airbag device.

[Explanation of symbols]

12 seat back 20 seat cover 22 Sewing line 32 airbags 40 power cloth 42 Bonding edge 44 Sutured edge

Claims (3)

[Claims] 1. A side airbag device in which an airbag built in a seat back ruptures and inflates a seat cover at a predetermined sewing line due to its inflation pressure, wherein the airbag is on a side of the seat back. The size is set so that it can be inflated and deployed over almost the entire area in the up-and-down direction, and the breaking area of the sewing line is expanded based on the increase in size of the airbag, and force is applied to the part where the breaking of the sewing line starts. The power cloth for concentrating is set in a rectangular shape in which the connecting edge connected to the frame of the seat back is short and the sewing edge sewn along the sewing line on the opposite side is long, and the power cloth is , A woven fabric is used, and at least one of the two sides connecting the corresponding ends of the connecting edge and the suture edge is aligned with the direction of the warp or weft of the woven fabric. A side airbag device for a vehicle seat that has been cut. 2. The side airbag device for a vehicle seat according to claim 1, wherein the webbing has a longer one of two sides connecting the corresponding edges of the coupling edge and the suture edge. A side airbag device for vehicle seats whose sides are aligned with the warp or weft direction of the woven fabric. 3. The side airbag device for a vehicle seat according to claim 1 or 2, wherein the connecting edge of the power cloth is:
A side airbag device for a vehicle seat, which is set to have substantially the same length as a connecting edge of a power cloth used for a small side airbag.