JPH11180244A - Air bag for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To providce an air bag for vehicle by which the concentration of stress to a sewing thread of a sewn part for regulation and the impairing of strength of a base cloth in the expansion can be prevented even if it has the sewn part for regulation. SOLUTION: An air bag 16 comprises a sewn part for regulation 21 formed by sewing the opposite base cloths 17, 18 mutually to regulate the volume in the expansion. The sewn part for regulation 21 is formed into the shape of a ring having a circular corner part C by closing both ends 21a, 21a at the opening side in opposition to each other to form one opening 22.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an airbag for a vehicle having a regulating stitch portion formed by sewing opposing base cloths so as to regulate a volume when inflated.

[0002]

2. Description of the Related Art Conventionally, for example, a side-impact airbag has a regulating stitching portion formed by sewing opposing base cloths together so as to regulate a volume including a thickness when inflated. (See Japanese Patent Application Laid-Open No. 8-169294, DE19622225A1, etc.).

[0003] However, the conventional regulation suturing portion is formed by simply suturing opposing base cloths in a straight line or by suturing in a closed annular shape.

[0004] Therefore, in the regulation stitching portion sewn in a straight line, when the airbag is inflated, a large tensile stress is concentrated on both ends of the straight line, so that the suture may be easily broken.

[0005] Further, in the regulation stitching portion sewn in an annular shape, stress concentration that would break the suture is unlikely to occur, but the sewing start position between the opposing base fabrics when suturing in a closed annular shape and the suturing. The end position overlaps, and in the overlapped portion, a large number of through holes are formed in the base cloth by the sutures penetrating through the base cloth, thereby reducing the strength of the base cloth. .

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and it is possible to reduce the concentration of stress on the sutures of the regulating sutures and the decrease in the strength of the base cloth when the regulating sutures are inflated even if the regulating sutures are provided. It is an object of the present invention to provide a vehicle airbag that can be suppressed.

[0007]

SUMMARY OF THE INVENTION A vehicle airbag according to the present invention has a regulating stitching portion formed by suturing opposing base fabrics so as to regulate the volume when inflated. The regulating stitching portion is formed as an annular shape having an arc-shaped corner portion by providing one opening so that both ends on the opening side face each other while approaching each other. It is characterized by the following.

It is desirable that the opening is disposed on a side away from the upstream side of the inflation gas flowing at the time of inflation.

It is preferable that the restricting suturing portion is provided on both sides of the opening so as to protrude so as to cover the opening.

[0010]

In the airbag for a vehicle according to the present invention, the regulating suturing portion is different from the linear suturing portion in which both ends of the regulating suturing portion are directed away from each other in the opposite direction. Are formed so that both ends on the opening side of the regulating suture portion are opposed to each other while approaching each other. Therefore, at the time of inflation of the airbag, the tensile force applied to the opening side ends of the regulating suture portion where stress concentration tends to occur is roughly divided into a force acting in the opening width direction of the opening of the regulating suture portion and The force acting in the direction orthogonal to the opening width direction is divided into two, but for the force acting in the opening width direction, both ends in the opening width direction of the regulating suture are received, Stress concentration hardly occurs at both ends on the opening side of the regulating suture.

[0011] Even if both ends in the opening width direction of the regulating sutures which receive the tensile force at the time of expansion are corners, the corners of the regulating sutures themselves are formed in an arc shape. Stress concentration hardly occurs at the corners of

Further, since the openings are arranged, both ends of the regulating suture do not overlap, and the strength of the base cloth does not decrease.

Therefore, in the airbag for a vehicle according to the present invention, even when the regulating stitching portion is provided, it is possible to suppress the concentration of stress on the suture of the regulating stitching portion at the time of inflation and a decrease in the strength of the base cloth. Thus, the strength of the airbag itself can be improved.

If the opening is arranged on the side remote from the upstream side of the inflation gas flowing during inflation, both ends of the opening of the regulating suture are exposed to the high-temperature inflation gas at the beginning of discharge. Instead, it is possible to protect both ends on the opening side of the regulation suturing portion, which can contribute to improvement in the strength of the regulation suturing portion.

[0015] In addition, if an overhanging portion is provided on both sides of the opening portion of the regulating suture portion so as to cover the opening portion,
Both ends on the opening side of the regulating suture portion can be arranged at the back near the center between the overhang portions. Since both ends on the opening side of the regulating suture are covered with the continuous suturing portion on the opposite side of the overhanging portion, the periphery is surrounded by the suturing portion continuous with the overhanging portion. The force acting in the direction perpendicular to the width direction is also less likely to act, so that stress concentration is less likely to occur, and it is less likely to be directly exposed to a high-temperature inflation gas, so that the strength of the airbag can be improved.

[0016]

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

The vehicle airbag 16 of the embodiment is shown in FIG.
As shown in 2, the airbag device 10 is used for a side collision airbag device 10 that is disposed at a portion of the backrest 2 of the seat 1 on the vehicle outside.

The backrest 2 is provided with a frame 3 which is disposed in a substantially vertical direction.
Are fixed to the frame 3 with the bolts 13b of the mounting bracket 13 fixed to the nut 8. Reference numeral 4 denotes a cushion, reference numerals 5 and 6 denote skins made of decorative cloth or the like, and reference numeral 7 denotes a cover which is attached to the outer portion of the backrest 2 and opens when the airbag 16 is inflated.

The side collision airbag device 10 includes a case 1 that covers the folded airbag 16 in addition to the airbag 16.
1, an inflator 12 for supplying an inflation gas to the airbag 16, and a mounting bracket 13. The case 11 includes a door 11a that opens when the airbag 16 is inflated. The inflator 12 is of a cylinder type disposed inside the airbag 16, and has a gas discharge port 12a for discharging an inflation gas at a predetermined position. Mounting bracket 13
Is provided with a cylindrical portion 13a for holding the inflator 12, and a bolt 13b extending from the cylindrical portion 13a.

As shown in FIGS. 1 to 4, the side-impact airbag 16 is formed by suturing peripheral edges of two base cloths 17 and 18 cut into substantially the same shape with a suture thread 15 to form a suturing portion 20. Is formed into a bag shape, and the central cloths 17 and 18 are sewn together near the center thereof with a suture thread 15 with a reinforcing cloth 19 interposed therebetween to form a regulating suture portion 21. Base cloth 17
Numeral 18 is made of a woven fabric such as polyamide or polyester, and the suture 15 is also made of polyamide yarn or the like. Further, the stitching portions 20 and 21 are formed by sewing methods such as lock stitches and chain stitches. Further, the reinforcing cloth 1
9 is formed from a cloth material of the same material as the base cloths 17 and 18.

The regulating suture 21 of the embodiment is
One opening 22 is provided so that both ends 21a on the opening side are opposed to each other while approaching each other, and the corner C is formed in an annular shape having a circular arc shape. In addition, the opening 22 is disposed on a side away from the upstream side of the inflation gas G flowing during the inflation. Further, the regulating suture 21 of the embodiment is provided on both sides of the opening 22 with overhanging portions 23 projecting so as to cover the opening 22. The stitching portion 21 is formed in a “<” shape.

The production of the airbag 16 is performed by stacking the base fabrics 17 and 18 cut into a predetermined shape with the outer surfaces thereof facing each other, and leaving the part of the base fabrics 17 and 18 together with a suture thread. The sewn portion 15 is used to form the forming sewn portion 20 and turned over by using an unsewn unsewn portion so that the seam allowance is not exposed on the outer surface side. In addition, the reinforcing cloths 19 are sewed on the base cloths 17 and 18 in advance at the portions to be the regulation suturing portions 21. Then, after turning over, the end 21 on the opening side
a, the sewing machine starts to sew as one stroke from one side of a, forms a regulating stitching portion 21, and further attaches mounting brackets 13 from an unsewn portion on the outer peripheral edge.
2 is inserted into the airbag 16 and the bolts 13 b.
3b and the lead wire extending from the inflator 12
It can be manufactured by protruding from predetermined holes of Nos. 7 and 18 and suturing the unsewn portion on the outer peripheral edge.

Further, after the airbag 16 is folded, the airbag 16 is housed in the case 11 so that the bolts 13b are protruded, and the bolts 13b 13b are fixed to the nut 8, so that the air can be applied to the backrest 2 of the seat 1. Bag device 1
0 can be attached. After the airbag device 10 is attached, the seat 1 is covered with the skins 5 and 6 and the cover 7.
Attachment is completed, and assembly is completed, and the vehicle is mounted on the vehicle. Also, when mounting the seat 1 on a vehicle,
The lead wire extending from the inflator 12 is connected to a predetermined airbag operation circuit of the vehicle.

When a predetermined signal is input to the inflator 12 after the airbag device 10 is mounted on the vehicle,
The inflation gas G is discharged from the gas discharge port 12a of the inflator 12, and the airbag 16 pushes the door portion 11a and the cover 7 to open, and as shown by a two-dot chain line in FIGS. In a state where the volume including the thickness is regulated at 21, it expands greatly.

At that time, in the airbag 16 of the embodiment,
Unlike the linear suturing portion in which the regulation suturing portion 21 is directed in the opposite direction while separating both ends of the regulation suturing portion, the opening side of the regulation suturing portion 21 is provided with the opening 22 interposed therebetween. Are formed so that both end portions 21a of each of them are opposed to each other while approaching each other. Therefore, when the airbag 16 is inflated, the tensile force applied to the opening-side end portions 21a of the regulation stitching portion 21 where stress concentration is likely to occur is roughly divided in the opening width direction X of the opening portion 22 of the regulation stitching portion 21. The force acting in the opening width direction X is divided into a force acting in the opening width direction X and a force acting in the direction Y orthogonal to the opening width direction X. Both ends 21b and 21 of
In this case, stress concentration hardly occurs at both ends 21a on the opening side of the regulating suture 21.

Even if both ends 21b in the opening width direction X of the regulating suture 21 that receive the tensile force at the time of expansion are corners C, the corners C themselves of the regulating suture 21 are arc-shaped. Therefore, stress concentration hardly occurs at those corner portions C.

Also, since the opening 22 is arranged,
Both ends 21a of the regulation suture 21 do not overlap,
The strength of the base fabrics 17 and 18 does not decrease.

Therefore, in the airbag 16 of the embodiment, even when the regulating stitching portion 21 is provided, stress concentration on the suture 15 of the regulating stitching portion 21 at the time of inflation and strength of the base fabrics 17 and 18 are increased. The decrease can be suppressed, and the strength of the airbag 16 itself can be improved.

The opening width B1 of the opening 22 in the embodiment is shown.
It is desirable that the space B2 between the overhanging portions 23 is provided at least 5 mm. If these dimensions B1 and B2 are too small, there is a risk that the ends 21a and 21a and the overhangs 23 and 23 may overlap each other due to an error in suturing.

It is desirable that the radius R of the corner portion C on the outer peripheral side of the regulating stitching portion 21 be 10 mm or more. If the thickness is less than 10 mm, there is a possibility that the tensile force generated at the time of expansion may be concentrated on the portion.

In the embodiment, since the opening 22 is disposed on the side away from the upstream side of the inflation gas G flowing during inflation, the opening side end 21 of the regulating suture 21 is provided.
The sutures 15a and 21a are not exposed to the high-temperature inflation gas G at the beginning of discharge, so that the opening-side ends 21a and 21a can be protected, and the strength of the regulation suture 21 is further improved. ing.

Further, in the embodiment, the regulating suture 21
Are provided on both sides of the opening 22 so as to cover the opening 22. Therefore, the opening side ends 21a of the regulating suture 21 are connected to the projecting portions 23. 23 can be arranged at the back near the center. Then, the opening-side end portions 21a and 2a of the regulating suture portion 21
1a, since the opposite side of the overhang portions 23 is also covered with the continuous suturing portion 21c, the periphery of the overhang portions 23
3 and the continuous suturing portion 21c, and the pulling force in the direction Y orthogonal to the opening width direction X is
3 and the continuous suturing portion 21c, the stress concentration is less likely to occur, and it is harder to be directly exposed to the high-temperature inflation gas, so that the strength of the airbag 16 can be improved.

Note that, as in the embodiment, a double inverted "C"
Even if it does not have a shape, as in the airbag 26 shown in FIG. 5, an annular shape having one opening 32 is provided so that both ends 31a on the opening side face each other while approaching each other. Both ends 31b in the opening width direction of the portion 32
A single-sided inverted “C” -shaped regulating stitching portion 31 having a circular arc-shaped corner portion 31b may be used. Even in this case, the functions and effects of the first and second aspects can be obtained. further,
In the case of a single regulation suturing portion, a simple annular regulation suturing portion having an opening may be used instead of a curved elliptical shape as shown in FIG. 5, but the front side end portions 31d and 31d. Thus, in the curved regulating suture portion 31 in which the opening side end portions 31a are inserted into the inflator 12 side,
This is preferable because the arc-shaped ends 31b and 31d strongly receive the tensile force, and the tensile force hardly acts on the opening-side ends 31a and 31a.

Further, as in an airbag 36 shown in FIG. 6, a second inverted "C" -shaped regulating stitching portion 41 having an opening 42 is provided with a second opening 44 provided therein. The “C” -shaped regulating stitching portion 43 may be provided, or an inverted “C” or “C” -shaped regulating stitching portion may be provided in three or more layers. Reference numerals 41a and 43a denote opening end portions,
b and 43b are arc-shaped corner portions at the ends in the opening width direction. Incidentally, the openings 44 and 42 are sequentially provided on the opposite side, and the respective ends 41a and 43 of the sutures 41 and 43 are provided.
It is preferable that stress concentration hardly occurs in a.

As described above, the multiple regulating sutures 4
In the case where the 1.43 is provided, after forming one stitching portion, the used suture thread 15 is once cut to form another stitching portion. It is desirable to form the restricting suture portion in an inverted “C” or “C” shape that is continuous with the stitch.

Further, the regulation suturing portion may be provided at a plurality of places instead of one place in the airbag.

Further, in the airbag 16 of the embodiment,
Although the opening 22 is configured to be opened obliquely downward, the lower side and the upper side are divided into two parts so as to protect the occupant's head and chest, as in an airbag 46 shown in FIG. In such a case, since the inflation gas G flows upward from the lower side, it is desirable to form the opening 52 that opens upward. In addition, 51a is an opening-side end, 51b is an end in the opening width direction, and 53 is an overhanging portion of the regulating suture.

Furthermore, in each of the embodiments, the airbag used for the side collision airbag device has been described. However, the airbag used for other passenger seat airbag devices, driver seat airbag devices, and the like. The present invention may be used for the following.

[Brief description of the drawings]

FIG. 1 is a side view of a seat accommodating an airbag according to an embodiment of the present invention.

FIG. 2 is a schematic sectional view taken along the line II-II in FIG.

FIG. 3 is a side view showing a state when the airbag of the embodiment is inflated.

FIG. 4 is an end view of a portion III-III in FIG. 4;

FIG. 5 is a side view showing a state when an airbag according to another embodiment is inflated.

FIG. 6 is a side view showing a state when an airbag according to still another embodiment is inflated.

FIG. 7 is a side view showing a state when an airbag according to still another embodiment is inflated.

[Explanation of symbols]

16.26.36.46 ... airbag, 17.18 ... base cloth, 21.31.41.43.51 ... regulating stitching part, 21a, 31a, 41a, 43a, 51a ... opening side end, 22. 32, 42, 44, 52: opening, 23, 53: overhang, C: corner, G: inflation gas.

Claims (3)

[Claims] 1. An airbag for a vehicle, comprising a regulating stitching portion formed by stitching opposed base fabrics together so as to regulate a volume at the time of inflation, wherein the regulating stitching portion has an opening side. An airbag for a vehicle, wherein one opening is provided so that both ends are opposed to each other while approaching each other, and formed as an annular shape having an arc-shaped corner portion. 2. The vehicle airbag according to claim 1, wherein the opening is disposed on a side away from an upstream side of the inflation gas flowing at the time of inflation. 3. The control suturing portion according to claim 1, wherein the regulating suturing portion includes, on both sides of the opening, a projecting portion projecting so as to cover the opening. The airbag for a vehicle as described in the above.