JP3941019B2 - Air bag for occupant protection device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an airbag used for an occupant protection device for a vehicle, and in particular, at the initial stage of deployment of an airbag, the occupant is restrained by the inflation force of the airbag by suppressing abnormal inflation in the direction of the occupant. The present invention relates to a structure of an air bag which prevents injury.
[0002]
[Prior art]
As shown in FIG. 4, a typical structure of a conventional airbag includes a front side base fabric 2 located on the passenger side and a back side base fabric 3 having a gas generator attachment port 3a for mounting the gas generator 5. Are overlapped, and the peripheral portions of both base fabrics 2 and 3 are sewn together by a sewing line 4 and formed into a bag shape. A gas generator 5 is inserted into the gas generator mounting port 3a of the back base fabric 3 of the airbag 1, and the flange 5b of the gas generator 5 and the peripheral edge 3b of the opening 3a of the back base fabric 3 are connected. The retainer 7, the retainer ring 8, and the fixing means 6 such as bolts are used for fixing.
[0003]
The airbag 1 is deployed in a very short time between the occupant and the vehicle body by the high-pressure gas that is rapidly released from the gas discharge port 5a of the gas generator 5, thereby mitigating the collision between the occupant and the vehicle body. . By the way, when the airbag 1 is inflated and deployed, first, as shown by a dotted line in the figure, first, there is a tendency that the airbag 1 rapidly and greatly expands forward. At this time, there may be a so-called punching phenomenon in which the front end portion 1a of the airbag collides with the occupant's face at a high speed. This causes the occupant's face to be scratched or the occupant's physique is small. There is even a fear of jumping violently.
[0004]
Therefore, in order to prevent this, as shown in FIG. 5, the center portion of the front side base fabric 2 and the gas generator attachment port peripheral edge 3 b of the back side base fabric 3 are connected by an expansion regulating member 20 such as a string. Measures have been proposed and implemented to prevent the front-side base fabric 2 from being excessively expanded forward.
[0005]
As another solution, there is a method using an auxiliary bag represented by JP-A-7-149199. In this method, as shown in FIG. 6, an auxiliary bag 21 having an appropriate size enough to cover the gas generator 5 is intermittently sewn in the vicinity 3 b of the opening of the backside base fabric 3 in the airbag 1. When the airbag 1 is inflated and deployed, the auxiliary bag 21 is first inflated, and gas is discharged into the airbag body from the gas passage 22 (unsewn portion) formed in the lateral direction of the auxiliary bag 21. Thus, the airbag 1 is always subjected to a lateral deployment force when deployed, and the airbag is prevented from expanding in the occupant direction.
[0006]
[Problems to be solved by the invention]
In the related art, first, in the method using the expansion regulating member 20 such as a string shown in FIG. For this purpose, it is necessary to sew the inner and outer base fabrics 2 and 3 and then turn them over to sew the expansion regulating member 20, so that it is inevitable that the sewing work becomes complicated. This is a manufacturing difficulty, and at the same time is a major factor in increasing the manufacturing cost.
[0007]
Further, in the method using the auxiliary bag 21 as shown in FIG. 6, a base fabric that is slightly larger than the gas generator 5 is sewed intermittently to the gas generator mounting port peripheral portion 3b of the back side base fabric 3 while being folded back. It is necessary to wear and requires complicated sewing work, and it is difficult to adopt in the trend of low price. In particular, in the case of an interrupted sewing line, the end processing of each sewing line is required, and the greater the number of interrupted sewing lines, the more complicated the process becomes. It was.
[0008]
In any case, these methods have a serious drawback in the sewing operation, and have a problem that must be improved in the trend of reducing the price of airbags. Therefore, the present invention has an object to provide a novel airbag structure that enables prevention of abnormal bulging at the initial stage of airbag deployment by simple sewing work without requiring such complicated sewing work. Is.
[0009]
[Means for Solving the Problems]
In order to solve the above problems, the present invention is an airbag (1) for an occupant protection device that is deployed by gas released from a gas generator (5),
Cover the front base fabric (2) located on the passenger side, the back base fabric (3) having the gas generator mounting port (3a), and the gas generator mounting port (3a) of the back base fabric (3) The inner fabric (9) sewn on the back base fabric (3)
A sewing line (10) between the inner cloth (9) and the back base cloth (3) is a peripheral sewing line for intermittently sewing the peripheral part of the inner cloth (9) to the back base cloth (3). (10a) and a bent sewing line (10b) having a corner portion (10c) bent toward the center direction of the inner cloth (9) between the peripheral sewing lines, and the peripheral sewing line (10a) The occupant protection device airbag is characterized in that the bent sewing line (10b) is formed of a continuous sewing line (10) .
[0010]
The present invention also provides an occupant protection device airbag (1) that is deployed by gas released from a gas generator (5),
Cover the front base fabric (2) located on the passenger side, the back base fabric (3) having the gas generator mounting port (3a), and the gas generator mounting port (3a) of the back base fabric (3) The inner fabric (9) sewn on the back base fabric (3)
A sewing line (10) between the inner cloth (9) and the back base cloth (3) is a peripheral sewing line for intermittently sewing the peripheral part of the inner cloth (9) to the back base cloth (3). (10a) and a bent sewing line (10b) having a corner (10c) are formed, and the peripheral sewing line (10a) is composed of a plurality of folded sewing lines, and the bent sewing line (10b) Constitutes an airbag for an occupant protection device, characterized in that it consists of a single sewing line .
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings. 1 is a plan view of the back side of the airbag according to the present invention, and FIG. 2 is a schematic sectional view showing an initial state of the airbag corresponding to the AA sectional view of FIG. These are the schematic sectional drawings which showed the state of the late stage of the expansion | deployment. First, in FIG. 1, the airbag of the present invention includes a circular front side base fabric 2, and a back side base fabric 3 in which a gas generator attachment port 3a is formed at the center and a plurality of gas discharge holes 12 are formed at appropriate positions in the middle. And the peripheral edge thereof is sewn and integrated with a sewing line 4 to form the airbag 1.
[0012]
Between the front side base fabric 2 and the back side base fabric 3 , an inner fabric 9 having a smaller diameter than the back side base fabric 2 is disposed so as to cover the gas generator 5. Sewn to the base fabric 3 . The sewing line 10 of the inner cloth 9 is formed between a peripheral sewing line 10a in which peripheral portions of the inner cloth 9 are sewn to the back-side base cloth 3, and the peripheral sewing line 10a in the center direction of the inner cloth 9. The bent sewing line 10b is bent in a substantially "<" shape, and a corner 10c is formed at the tip of the bent sewing line 10b.
[0013]
Next, the behavior when the airbag is deployed will be described. When the automobile collides and the gas generator 5 is activated by the impact, a high-pressure gas is rapidly released from the gas discharge port 5a of the gas generator 5. As shown in FIG. High-pressure gas is supplied into the first space A1 formed between the back-side base cloth 3 and the inner cloth 9, and the first space A1 is expanded. Although the airbag is folded and mounted in the airbag module, FIG. 2 shows the airbag opened for easy understanding.
[0014]
Since the expansion of the first space A1 is the expansion of the inner cloth 9, as the inner cloth 9 expands, tensile stress concentrates on the corner portion 10c of the bent sewing line 10b. , broken the bend sewing line 10b is at the corner 10c, as shown in FIG. 3,該破sectional portion 11 becomes a gas passage, high pressure gas, the second space A2 formed inside of the front base fabric 2 And the second space A2 is expanded. As a result, in the initial stage of airbag deployment, the second space A2 on the occupant side is hardly inflated, and the inflation of the airbag in the front-rear direction toward the occupant is almost inflated in the first space A1. Therefore, as described above, the punching phenomenon to the occupant due to abnormal bulging forward in the initial stage of airbag deployment does not occur.
[0015]
Next, when the pressure in the first space A1 is gradually increased by the high-pressure gas continuously supplied from the gas generator 5, and the first space A1 is fully developed, the gas passage 11 formed in the corner portion 10c. Is opened to the maximum, and the gas is ejected laterally from the first space A1 to the second space A2, and the second space A2 is rapidly and laterally expanded to complete the deployment of the airbag. In the expansion of the second space A2, the inner cloth 9 is intermittently sewn to the back side base cloth 2 at the peripheral edge thereof. As shown in FIG. 5, the outer portion of the bent sewing line 10b of the inner cloth 9, that is, the portion 9a where the peripheral sewing line does not exist, serves as a guide member for injecting high-pressure gas laterally into the second space A2. Therefore, also from this point of view, the lateral deployment force is increased, and the forward deployment of the airbag is suppressed.
[0016]
As in this example, when the bent sewing line 10b is disposed at the left and right positions with respect to the occupant, the airbag starts to deploy from the left and right directions, so that abnormal bulge to the front is prevented and the occupant's It is possible to safely cope with a shake with respect to the left and right positions.
[0017]
Next, the manufacturing process of the airbag will be described. A front side base fabric 2, a back side base fabric 3 and an inner side fabric 9 cut to a predetermined size and shape are prepared. The concentric circles are arranged so as to cover the generator attachment port 3a, and the peripheral sewing line 10a for sewing the peripheral portion of the inner cloth 9 and the back base cloth 3 and the inner cloth 9 and the back base cloth 3 are gas pressured. The bent sewing line 10b that is sewn to the extent that it can be broken is formed in order and integrated with each other. Here, since the peripheral sewing line 10a needs to be firmly sewn so as not to be broken by the gas pressure, the sewing line is reciprocated once or more times as shown in FIG. The bent sewing line 10b is formed by a single sewing line so that the corner 10c is easily broken by the gas pressure. Next, the front side base fabric 2 and the back side base fabric 3 are overlapped, and the peripheral portions of both base fabrics 2 and 3 are firmly sewn by the sewing line 4 to complete the production of the airbag.
[0018]
Here, since the peripheral sewing line 10a and the bent sewing line 10b are formed by continuous sewing lines, it is not necessary to perform terminal processing of the start and end portions for each sewing line in the middle of sewing. Sewing is completed by terminal processing. In addition, since the sewing work is performed only by a simple sewing work in which the material to be sewn is arranged horizontally, the sewing process of the airbag becomes extremely simple. As a result, the sewn line 4 at the peripheral edge of the front side base fabric 2 and the back side base fabric 3 is exposed to the outside, but whether or not the sewn line 4 is exposed mainly depends on the appearance of the airbag. It is a problem, and the airbag itself is folded and installed in the airbag module as is well known, and is not visible from the outside. Furthermore, if this exposed part is folded so that the exposed part does not hit the occupant when the airbag is deployed, it is completely unrelated to the performance and function of the airbag. If considered, this method can be said to be a very rational sewing method.
[0019]
【The invention's effect】
As described above, according to the present invention, the inner cloth 9 and the back base cloth 3 are sewn with the continuous sewing line 10, and the corner portion 10c formed at an appropriate position of the sewing line 10 is formed on the airbag. Since it is configured to break when deployed, the first space A1 formed between the inner cloth 9 and the back base cloth 3 is first expanded by the high-pressure gas released from the gas generator 5, and subsequently Thus, the outer second space A2 is inflated through the opening formed by the breakage of the corner portion 10c by the expansion of the first space A1, and the airbag is deployed forward in the occupant direction. It will be deployed securely in the horizontal direction. Thereby, the punching phenomenon that may cause injury to the occupant is surely prevented, and the safety of the airbag is further improved.
[0020]
In addition, by making the peripheral sewing line 10a and the bent sewing line 10b one continuous sewing line, the terminal processing of each sewing line is completed only once compared to the conventional intermittent sewing work, so the sewing work is simple. It is expected to contribute to reducing the cost of airbags.
[Brief description of the drawings]
FIG. 1 is a plan view of an airbag according to the present invention.
FIG. 2 is a schematic view corresponding to a cross section taken along the line AA of FIG. 1, showing an initial state of the airbag according to the present invention.
3 is a schematic cross-sectional view showing a state in a later stage of deployment of the airbag of FIG. 2. FIG.
FIG. 4 is a conceptual diagram showing a deployed state of a conventional airbag.
FIG. 5 is a conceptual diagram showing a deployment state of an airbag using a conventional front deployment regulating member.
FIG. 6 is a conceptual diagram showing a deployed state of an airbag using a conventional auxiliary bag.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Airbag 2 Front side base cloth 3 Back side base cloth 4 Sewing line 5 of front side base cloth and back side base cloth 5 Gas generator 9 Inner cloth 10 Sewing line 10a of inner cloth Peripheral sewing line 10b Bending sewing line 10c Corner | angular part of bending sewing line 11 Gas passage (breaking part)

Claims (5)

An occupant protection device airbag (1) deployed by gas released from a gas generator (5),
Cover the front base fabric (2) located on the passenger side, the back base fabric (3) having the gas generator mounting port (3a), and the gas generator mounting port (3a) of the back base fabric (3) The inner fabric (9) sewn on the back base fabric (3)
A sewing line (10) between the inner cloth (9) and the back base cloth (3) is a peripheral sewing line for intermittently sewing the peripheral part of the inner cloth (9) to the back base cloth (3). (10a) and a substantially "<" shape that is bent toward the center of the inner cloth (9) between the peripheral sewing lines, and breaks due to stress concentration when the inner cloth is inflated at the initial stage of airbag deployment. As described above, the peripheral sewing line (10a) and the bending sewing line (10b) are formed by a continuous sewing line (10). Air bag for occupant protection device An occupant protection device airbag (1) deployed by gas released from a gas generator (5),
Cover the front base fabric (2) located on the passenger side, the back base fabric (3) having the gas generator mounting port (3a), and the gas generator mounting port (3a) of the back base fabric (3) The inner fabric (9) sewn on the back base fabric (3)
A sewing line (10) between the inner cloth (9) and the back base cloth (3) is a peripheral sewing line for intermittently sewing the peripheral part of the inner cloth (9) to the back base cloth (3). (10a) and a bent sewing line (10b) having a corner (10c) are formed so as to be broken due to stress concentration when the inner fabric is inflated at the initial stage of airbag deployment, and the peripheral sewing line (10a) is folded back. An airbag for an occupant protection device , wherein the bent sewing line (10b) is formed of a single sewing line.   The airbag for an occupant protection device according to claim 1 or 2, wherein the bent sewing line (10b) is disposed at a left and right position of the airbag. The peripheral sewing line (10a) is composed of a plurality of sewing lines which are folded garment, the bent sewing line (10b) is for passenger protection device according to claim 1 is made of a single sewing line Airbag for airbag occupant protection device The airbag for an occupant protection device according to claim 4, wherein the bent sewing line (10b) is disposed at a left and right position of the airbag.

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