JPH10315892A - Air bag for assistant's seat of car - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an assistant seat air bag which can be sewn while the coupling strength of the gas inlet side end part of a tether with the air bag body is heightened and which can be inflated into the specified shape. SOLUTION: An air bag B1 is equipped internally with a tether 31 so that a sack-shaped air bag body 21 furnished with a gas inlet 22 couples the peripheral edge of the gas inlet with that part of ceiling wall 25 opposing to the gas inlet. The two ends of the tether 31 are sewn in the width direction to the peripheral edge of the gas inlet and the ceiling wall part. The sewing position of tether 31 with respect to the peripheral edge of the gas inlet is equipped at the ends of tether about the width direction with curves 33a which extend in the shape of an arc toward that end part located farther from the ceiling wall part 25.

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 passenger airbag device provided on an instrument panel or the like in front of a passenger seat of an automobile.

[0002]

2. Description of the Related Art Conventionally, in a passenger airbag, the shape of a bag-shaped airbag body in an inflated state has been regulated, and further, the flow of inflation gas flowing from a gas inlet during inflation. In order to regulate the airbag body and the initial shape of the inflation of the airbag body, a tether is provided inside the airbag body.

As shown in FIG. 1, the tether 4 is arranged such that both ends thereof are sewn to the periphery of the gas inlet 2 of the airbag body 1 and the ceiling wall 3 facing the gas inlet 2. Some were set up. In this tether 4,
The suture portion 6 at the gas inlet side end 5 and the suture portion 8 at the ceiling wall side end 7 of the tether 4 transfer the suture 10 to the tether 4.
Suturing in the width direction.

However, such a passenger airbag B
0, the ceiling wall 3 of the airbag body 1 expands away from the gas inlet 2 at the time of inflation, and the tether 4 opposes the pulling force of the ceiling wall 3 in the protruding direction. In the airbag body 1, a larger tensile force acts than the base cloth 1 a constituting the airbag body 1, and the end portion 5 of the tether 4 on the side of the gas inlet 2 is connected to the airbag body 1. Since the part is attached to the apparatus and is stopped, a larger tensile force acts on the end part 7 on the ceiling wall 3 side.

[0005] As shown in FIG. 1, at the suturing site 6 of the gas inlet side end 5, a right angle is formed from both ends thereof to the end 5 side of the tether 4 so as to form an edge-shaped corner C. When the airbag B0 is inflated, stress concentrates on the sewn corner portion C, and the suture thread 10 sewn the corner portion C breaks when the airbag B0 is inflated. As a result, the length of the tether 4 may be increased, and the airbag body 1 may not be able to be regulated to a predetermined shape. Alternatively, the tether 4 itself may break along the width direction starting from the corner C instead of the suture thread 10.

The reason why the linear portion 9 is provided is that the airbag B0 includes the base cloth 1a of the airbag body 1 and the reinforcing cloth 1b.
It is necessary to reinforce the peripheral edge of the gas inlet 2. However, when forming a suture portion 11 for suturing the both with the suture 10, the suture is continuously sewn so that the processing of the suture 10 is easy. Since the workability is better when the portion 6 is sewn, the straight portion 9 is provided. Therefore, if the processing of the yarn 10 is not considered, the linear portion 9 may not be provided. By the way, even when the linear portion 9 is not provided, when the airbag is inflated,
Since stress concentration occurs at both ends of the suturing portion 6, breakage of the suture 10 at those ends was difficult to suppress.

[0007] Even if the stitching portion 6 is provided in the entire width direction of the tether 5 without providing the linear portion 9, the tether 5 is broken at the portion of the linear stitching portion 6 when the airbag is inflated. A case has arisen.

The present invention has been made to solve the above-mentioned problem, and it is possible to improve the connection strength of an end of a tether on the gas inlet side to an airbag body, to sew the tether, and to inflate a passenger seat into a predetermined shape. The purpose of the present invention is to provide an airbag.

[0009]

In a passenger airbag according to the present invention, a bag-shaped airbag body having a gas inlet is provided on a ceiling wall portion facing the periphery of the gas inlet and the gas inlet. A tether is disposed inside the tether, and the tether is sewn at both ends in the width direction to the peripheral edge of the gas inlet and the ceiling wall, respectively. In the seat airbag, a sewn portion of the tether to the gas inlet peripheral edge has a curved portion extending in an arc shape to an end portion away from the ceiling wall portion at both ends in the width direction of the tether. It is characterized by comprising.

A sewn portion of the tether to the periphery of the gas inlet is formed in a substantially semicircular shape by connecting the curved portions to each other, and the diameter of the substantially semicircular shape is substantially equal to the width of the tether. It is desirable.

[0011]

According to the airbag for a passenger seat according to the present invention,
At both ends in the tether width direction of the suture portion at the gas inlet side end of the tether, curved portions extending in an arc shape to the end side away from the ceiling wall portion are formed, so that an edge shape which tends to cause stress concentration is formed. No corners or separated terminals are formed.

Therefore, even when the airbag is inflated and a large tension acts on the tether, the tensile force is dispersed at the curved portion, and the breakage of the suture and the tether itself can be prevented.

Therefore, in the passenger airbag according to the present invention, it is possible to improve the connection strength of the gas inlet side end of the tether to the airbag body and to sew the airbag. In the middle or at the time of completion of the expansion, the expansion shape is regulated to a predetermined shape, and the expansion can be performed.

[0014] Then, with respect to the suturing portion of the tether to the peripheral edge of the gas inlet, the curved portions at both ends in the tether width direction are connected to each other to form a substantially semicircular shape.
When the width of the tether is set to be substantially equal to the width of the tether, the tether is sewn over a wide range in the width direction of the tether so as to disperse the tensile force at the time of inflation of the airbag, so that no stress concentration occurs. Because it can be sewn to the main body, the connection strength of the gas inlet side end of the tether to the airbag main body can be further increased,
An inflator or the like having a high output can be used, and the time until the completion of the inflation can be reduced while regulating the inflation shape.

[0015]

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

As shown in FIG. 5A, a passenger airbag B1 of the embodiment is a passenger airbag disposed at an instrument panel (hereinafter abbreviated as an instrument panel) 13 in front of the passenger seat. Used for the device M,
The passenger-seat airbag device M includes an airbag B1, an inflator 18 for supplying inflation gas to the airbag B1, a case 17 for accommodating the airbag B1 and the inflator 18, and a case 17 for connecting the airbag B1 to the case 17. And a retainer 19 to be attached.

A door 14 is provided on the instrument panel 13 so as to cover the case 17.
When the airbag 1 is inflated, as shown in FIG. 5B, the airbag B1 is configured to be opened by being pushed by the airbag B1 around the hinge 15 as a rotation center.

The case 17 is made of a substantially rectangular parallelepiped sheet metal and includes two chambers, a lower chamber 17a and an upper chamber 17b having a larger volume than the lower chamber 17a.
A step 17c having a plurality of through holes 17d is provided between the upper chamber 17b and the upper chamber 17b. Case 17
Is provided with a bracket (not shown) for mounting and fixing to a predetermined position of the vehicle.

The inflator 18 is a cylinder type having a gas discharge port 18a for discharging an inflation gas, and is housed and held in a lower chamber 17a of a case 17.

As shown in FIGS. 2 to 5, the airbag B1 includes an airbag main body 21 and a tether 31 disposed inside the airbag main body 21.

The airbag body 21 has a substantially square cylindrical bag shape and is provided with a gas inlet 22 opened in a rectangular shape. A portion of the airbag body 21 that faces the gas inlet 22 during inflation is a ceiling wall 25. Around the gas inlet 22, two mounting pieces 2
3 and 24 are provided, and each mounting piece 23 and 24 has
A predetermined number of mounting holes 23a and 24a are penetrated. Each of the mounting pieces 23 and 24 is brought into contact with the step 17c of the case 17 with a bolt 19a protruding from the rectangular annular retainer 19 being inserted into each of the mounting holes 23a and 24a from inside the airbag body 21. Each through hole 17d of the step 17c
The nut 20 is screwed into each of the bolts 19a that penetrate through the hole, thereby being fixedly attached to the step 17c.

As shown in FIGS. 2 and 4, the airbag main body 21 has a single main fabric 26 constituting the upper surface side, the ceiling wall portion 25, and the lower surface side when inflated, and the left and right side surfaces when inflated. And two base fabrics 28 and
28, reinforcing cloths 27 and 29 disposed on the inner peripheral surface side of the peripheral edge of the gas inlet 22. Each base cloth 26
28 and the reinforcing cloths 27 and 29 are made of a woven cloth such as polyester or polyamide, or a cloth material on which a predetermined heat-resistant coating is applied. The airbag body 21 is formed by sewing a peripheral edge of the main base cloth 26 in a state where the reinforcing cloth 27 or the tether 31 is sewn and a peripheral edge of two side base cloths 28 in which the reinforcing cloth 29 is sewn. It is formed in a shape.

The tether 31 is formed of the same material as the base cloths 26 and 28, and uses sutures 40 at both ends, as shown in FIGS. With respect to the periphery of the gas inlet 22 and the ceiling wall 25,
Stitched in the width direction and connected. The suturing portion 33 of the gas inlet side end 32 of the tether 31 is formed in a substantially semicircular shape by connecting the approximately 1/4 circular arc-shaped curved portions 33a to each other. The diameter of this substantially semicircular shape is set to be substantially equal to the narrowed width dimension W of the tether 31.
The stitching portion 35 of the ceiling wall side end 34 of the tether 31 is formed in an oval shape extending in the width direction of the tether 31.

The tether 31 regulates the shape of the airbag body 21 so that the distance from the gas inlet 22 of the airbag body 21 to the ceiling wall 25 at the time of completion of inflation is constant, and the tether 31 is in the middle of inflation. Then, the airbag body 21
The upper chamber 21a above the tether 31 is arranged so as to regulate the shape of the upper chamber 21a below the tether 31 so that the upper chamber 21a is expanded more quickly than the lower chamber 21b below the tether 31.
The inflation gas from the upper chamber 21a to the lower chamber 21b flows through the left and right recesses 31a of the tether 31.

Next, the manufacture of the airbag B1 will be described. The base cloths 26, 28, the reinforcing cloths 27, 29, and the tether 31 are cut and prepared in a predetermined shape. Then, the reinforcing cloths 27 are arranged at predetermined positions.

Each of the reinforcing cloths 27 is sewn to the base cloth 26 by using the suture thread 40, and while the other reinforcing cloth 27 is being sewn, the gas inlet side end 32 of the tether 31 is sewn. Is put on one of the reinforcing cloths 27 and stitched. That is, as shown in FIG.
Of the sewn portions 30 to be sewn to the base cloth 26,
After sequentially suturing the side portion 30b, the upper portion 30c, the side portion 30d, and the middle portion 30e, the gas inlet end 32 of the tether 31 is applied to the common side portion 30f, the common lower portion 30g, and the common side portion 30h.
In the process of suturing the common lower part 30g, a part of the common lower part 30g is double-sewn and the stitched part 33 is sewn so as to draw one stroke.

Next, the ceiling wall side end 34 of the tether 31
Is applied to a predetermined position corresponding to the ceiling wall portion 25 of the base cloth 26, a suture portion 35 is formed by the suture thread 40, the tether 31 is connected to the base cloth 26, and then the mounting hole 23a is formed. .

The reinforcing cloth 2 is also provided on each side base cloth 28.
9 and stitched, and a mounting hole 24a is formed.

Then, when the peripheral edges of the base fabrics 26 and 28 are sewn together, the airbag B1 can be manufactured.

Thereafter, each bolt 19a is connected to the mounting hole 23a.
The airbag B1 is folded by placing the retainer 19 in the airbag B1 so as to protrude from the airbag 24a, and then the airbag B1 is stored in the upper chamber 17b of the case 17 in which the inflator 18 has been stored, and each bolt 19a
Is projected from the through hole 17d and the nut 20 is fixed.
If the airbag device M can be assembled and further fixed to the lower part of the instrument panel 13 using a bracket (not shown) of the case 17, as shown in FIG.
The airbag device M can be mounted on a vehicle.

After the inflation gas is discharged from the gas discharge port 18a of the inflator 18 after the airbag device M is mounted on the vehicle, the inflation gas flows from the gas inflow port 22 as shown in FIG. After flowing into the bag body 21, the airbag body 21 expands by opening the door portion 14 of the instrument panel 13, the ceiling wall portion 25 is separated from the gas inlet 22, and the flow of the inflation gas is regulated by the tether 31. Thereby, the upper chamber 21a expands faster than the lower chamber 21b,
The tether 31 extends to complete the inflation.

When the inflation is completed, even if a large tension acts on the tether 31, the sewn portion 33 of the gas inlet side end portion 32 may have an edge-shaped corner portion where stress concentration is likely to occur or may be cut off. Terminal is not formed and the curved portion 33
In the mode in which the tensile force is dispersed by a and 33a, breakage of the suture thread 40 and the tether 31 itself can be prevented.

Therefore, in the airbag B1 of the embodiment, the connection strength of the gas inlet side end 32 of the tether 31 to the airbag main body 21 can be improved and suturing can be performed. During the expansion or when the expansion is completed, the expansion shape is regulated to a predetermined shape, and the expansion can be performed.

In particular, in the embodiment, regarding the stitching portion 33 of the gas inlet side end 32 of the tether 31, the curved portions 33a at the both ends in the tether width direction are connected to each other,
It is formed in a substantially semicircular shape, and its substantially semicircular diameter is
The width of the tether 31 is set to be substantially equal to the width W of the tether 31 so as to disperse the tensile force at the time of inflation of the airbag. Since the sewing machine can be sewn to the airbag body 21, the connection strength of the gas inlet side end 32 of the tether 31 to the airbag body 21 can be further increased, and the inflator 18 having a high output can be used. Further, it is possible to shorten the time until the completion of the expansion while regulating the expansion shape.

In the embodiment, the case where the suture thread 40 is sewn in a substantially semicircular shape at the sewn portion 33 of the gas inlet side end portion 32 of the tether 31 has been described, but the airbag B2 shown in FIG. As described above, approximately １ ／ of the both ends of the tether 31 in the tether width direction at the gas inlet side end 32 of the tether 31 are provided.
Curved portions 43a, 43a extending toward the end portion away from the ceiling wall portion 25 are formed in a circular arc shape.
43a is connected by a connecting portion 43b so as to connect linearly,
The suture portion 43 of the gas inlet side end 32 of the tether 31 may be formed. By the way, when suturing the sewn portion 43, the reinforcing cloth 27 is sewn at the same time, so that the suture portions 30 and 43 can be sewn without cutting the sewn portion 40 so that the sewn portions 40 and 43 can be sewn straight. It is a straight part connected while being sewn.

Even in such an airbag B2, since an edge-shaped corner portion where a stress concentration is apt to occur or a separated terminal is not formed, the airbag B2 expands and a large tension is applied to the tether 31. Acts, the tensile force is dispersed at the curved portion 43a, and the suture 40
Also, breakage of the tether 31 itself can be prevented.

Similarly, an airbag B3 as shown in FIG.
However, the same operation and effect as those of the airbag B2 can be obtained. In the airbag B3, a sewn portion 53 provided at the gas inlet side end 32 of the tether 31 is composed of two sewn portions 54, and each sewn portion 54 has a curved portion 54a at both ends in the tether width direction. 54a are connected to each other to form a substantially semicircular shape. In this manner, the suturing site 53 may be constituted by the plurality of suturing portions 54. Note that 55
When the suture portion 54 is sewn, the reinforcing cloth 27 is also sewn at the same time.
It is a linear portion that is connected while being sewn with a suture 40 in a straight line so that the sewn portions 54 and 54 can be sewn.

Further, in the airbag B4 shown in FIG.
The same operation and effect as those of the airbag B2 can be obtained. The airbag B4 is provided with a curved portion 63a extending toward the end portion away from the ceiling wall portion 25 in an approximately 1/4 circular arc shape at both ends in the tether width direction at the gas inlet side end portion 32 of the tether 31. 63a to form a mutually curved portion 63a.6
3a is connected by a connecting portion 63b sewn in a U-shape to form a sewn portion 63 of the gas inlet side end 32 of the tether 31, and such a configuration may be adopted. 64 sew the suture portions 63 without severing the thread 40 because the reinforcing cloth 27 is sewn at the same time when the suture portions 63 are sewn.
Is a straight line portion which is connected while being sewn with a suture thread 40 in a straight line so as to be sewn.

Further, the sewn portions 4 of the airbags B2 to B4
Curved portions 43a, 54a, 63a in 3.53.63
Is desirably 5 mm or more so that the tensile force acting upon expansion can be smoothly dispersed.

Further, the width of the sewn portions 43 and 63 such as the airbags B2 and B4 and the number of the sewn portions 53 such as the airbag B3 depend on the pulling force of the tether 31 by the output of the inflator 18. What is necessary is just to set suitably so that the suture 40 does not break.

[Brief description of the drawings]

FIG. 1 is a view showing a conventional manner of suturing a tether of a passenger airbag.

FIG. 2 is a perspective view of an airbag for a passenger seat according to an embodiment of the present invention when inflated.

FIG. 3 is a diagram showing a mode of suturing the tether in the airbag of the embodiment.

FIG. 4 is a diagram showing a cloth material constituting the airbag of the embodiment.

FIG. 5 is a view showing a stored state of the airbag of the airbag device in which the embodiment is used and an inflated state.

FIG. 6 is a diagram illustrating a suture mode of a tether in an airbag according to another embodiment.

FIG. 7 is a diagram showing a suture mode of a tether in an airbag according to another embodiment.

FIG. 8 is a diagram showing a tether sewing mode in an airbag according to another embodiment.

[Explanation of symbols]

 1.31, airbag body, 2.22, gas inlet, 3.25, ceiling wall, 4,31, tether, 5, 32, gas inlet side end, 6, 33, 43, 53, 63 ... Suturing site, 33a / 43a / 54a / 63a ... Curved portion, B0 / B1 / B2 / B3 / B4 ... Airbag for passenger seat.

Claims (2)

[Claims] 1. A bag-shaped airbag body having a gas inlet is provided with a tether therein so as to connect the peripheral edge of the gas inlet with a ceiling wall portion facing the gas inlet. An airbag for a passenger seat, wherein both ends of the tether are sewn in a width direction with respect to a periphery of the gas inlet and the ceiling wall, respectively, and the gas inlet of the tether is provided. The suture site to the periphery,
An airbag for a passenger's seat, characterized in that the tether is provided at both ends in the width direction with curved portions extending in an arc shape to an end portion away from the ceiling wall portion. 2. A suturing portion of the tether to a periphery of the gas inlet is formed in a substantially semicircular shape by connecting the curved portions to each other, and a diameter of the substantially semicircular shape is substantially equal to a width dimension of the tether. 2. The airbag for a passenger seat according to claim 1, wherein the airbags are equal.