JPH11342824A - Air bag device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an air bag device with a high safety having short developing time and sure stable absorption of the moving energy of occupants. SOLUTION: A blocking cloth 110 has a ventilation hole opening 120 of about a circular form at about its center, and the outer periphery of the blocking cloth 110, the periphery of the ventilation hole opening 120, and the periphery of a ventilation hole opening 130 with about a circular form provided to a base cloth 100, are provided to form concentric circles. From the edge of the periphery of the ventilation hole opening 120 of the blocking cloth 110, sewing machine perforations 111 at the positions reaching to the periphery of the ventilation opening 1 are provided on the radial lines making the center of the above about concentric circle as the starting points. The sewing machine perforations are provided at total 8 positions placing about 45 deg. intervals making the above center as the standard. When the gas pressure in the bag exceeds a specific value, the closing parts of the ventilation hole are rolled up by the breakage near the sewing machine perforations 111 provided to the blocking cloth 110, and they are opened to the place of the ventilation hole opening 130.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an airbag device provided on a driver's seat side or a passenger's seat side of a vehicle and used for protecting an occupant thereof. The present invention relates to a structure of an airbag having a vent hole for exhausting to the outside.

[0002]

2. Description of the Related Art FIG. 9 is a side view (a) of an airbag device having a vent according to the prior art, and a plan view (b) and a sectional view (c) showing the structure of the vent. The airbag storage case 300 is located above the instrument panel 510 in front of the front passenger seat inside the vehicle body 500 and normally stores an airbag mainly made of the base fabric 100 and having the inflator 400. When an abnormality such as a collision accident occurs, the airbag is deployed by the gas generated from the inflator 400 as shown in FIG. 9A to protect the occupant in the passenger seat. This airbag has a ventilation hole on the side surface of the bag body as shown in FIG. The base fabric 100 has a substantially circular vent opening 130, and the vent opening 13
0 is covered with a closing cloth 110 also serving as a substantially circular reinforcing cloth larger than the ventilation hole opening 130, and
00 and the closing cloth 110 are sewn by sewing thread 140 at a predetermined sewing position located around the ventilation hole opening 130 (FIGS. 9B and 9C). The closing cloth 110 is provided with a slit 910 in a cross shape, and the slit 910 is sewn with a sewing thread 920.
The final sewing thread 920 breaks when the gas pressure inside the airbag exceeds a predetermined value.
Alternatively, when the occupant collides with the airbag and the gas pressure in the airbag further increases, the final sewing thread 920 is broken. Therefore, this sewing thread breaking mechanism, when the airbag is deployed,
This prevents gas leakage and contributes to shortening the deployment time, and prevents the rupture of an unexpected portion of the airbag when the deployment of the airbag is completed. Further, when the occupant is protected after the deployment of the airbag, a certain amount of gas is exhausted from the ventilation hole opening 130 formed by the rupture, so that a repulsion phenomenon of the airbag to the occupant is avoided and the kinetic energy of the occupant is reduced. Contributes to stable absorption.

[0003] Depending on the speed and deceleration of the vehicle at the time of the collision,
The relative speed between the occupant and the airbag when the occupant collides with the airbag and the pressure exerted on the airbag by the occupant vary greatly. Therefore, in order to avoid the bottoming-out phenomenon of the airbag by the occupant, it is desirable that the gas pressure in the airbag be higher as the vehicle speed and deceleration at the time of the collision increase. Further, it is desirable that the deployment time of the airbag be shorter as the speed and deceleration of the vehicle at the time of the collision increase. For these reasons, it is desirable to supply a larger amount or higher pressure of gas from the inflator into the airbag as the speed and deceleration of the vehicle at the time of the collision increase. In order to respond to this demand, the amount and pressure of gas supplied into the airbag has been conventionally controlled by using a two-stage inflator and controlling the number of inflators to be fired according to the speed and deceleration of the vehicle at the time of collision. An airbag device for controlling the pressure has been developed.

[0004]

With the above-described two-stage inflator, when a large amount or high-pressure gas is supplied from the two inflators into the airbag, it is more developed than when the gas is supplied from one inflator. Since the gas pressure in the later bag becomes much higher, the impact on the occupant due to the repulsive force from the airbag when the occupant collides with the airbag also increases. In order to reduce the impact as much as possible, it is desirable to change the opening area of the vent hole stepwise or continuously according to the number of inflators to be ignited or the gas pressure in the airbag. That is, it is more desirable that the larger the number of inflators to be ignited or the gas pressure in the airbag, the larger the opening area of the vent hole is, in order to minimize the impact on the occupant. However, none of the conventional vents has an opening area variable mechanism that meets these requirements, and measures have not been taken sufficiently. Also, as in the above-described prior art (FIG. 9 (b)), in a vent having an initial value of the opening area of 0, a popping sound and a vibration when a predetermined portion is opened are large, and safety is increased. And had problems with comfort. In addition, since the opening area variable mechanism of the ventilation hole having a variable opening area is based on a balance between a change in gas pressure in the airbag and a mechanical strength of the opening,
It is conventionally difficult to set the critical point of the gas pressure at the time of opening the vent and the mechanical strength of the opening. For example, in the above-described conventional technique, the sewing thread 920 does not break or the opening area is not sufficiently obtained. In this case, the airbag deployment time can be shortened, but since the vent hole does not have a minimum opening area, the kinetic energy of the occupant cannot be stably absorbed by exhausting gas. .

SUMMARY OF THE INVENTION The present invention has been made to solve these problems, and an object of the present invention is to provide a highly safe air system that has a short deployment time and that ensures stable absorption of occupant kinetic energy. It is to provide a bag device.

[0006]

In order to solve the above-mentioned problems, the following means are effective. In other words, according to the first aspect of the present invention, a vent formed in a bag shape of a single or double structure by connecting the base fabric and exhausting a part of gas generated from the inflator to the outside of the base fabric is provided. In the airbag having, the opening area of the ventilation hole is a predetermined location of the base cloth, or a predetermined location of the closing cloth or reinforcing cloth provided at the opening of the ventilation hole, or a base cloth, a closing cloth or It changes according to the gas pressure due to breakage of a sewing thread for sewing a predetermined portion of the reinforcing cloth. In particular, when the opening area variable mechanism operates by bursting a predetermined portion of the base cloth, the closing cloth, or the reinforcing cloth, a new effect that the sewing with the sewing thread is not required is obtained. Note that this means is the most basic means that exhibits further effects when arbitrarily combined with the following means.

According to the second aspect of the present invention, in the first aspect, the initial value of the opening area of the ventilation hole is a certain finite constant value that is clearly larger than zero.
As a result, the opening area of the ventilation hole can be set stepwise, and when a multistage inflator with a multistage ignition device is used, the opening area of the ventilation hole also changes stepwise according to the gas pressure in the bag. Therefore, the gas pressure in the bag can be more stably maintained.
Also, even if a one-stage inflator is used, in the unlikely event that the opening area variable mechanism does not work, the kinetic energy of the occupant due to the exhaust of gas is reduced because the vent has a minimum opening area. Thus, the vent can serve as a safety mechanism in such a case. In addition, since the initial value of the opening area is not 0, a popping sound and a vibration when a predetermined portion is opened can be suppressed, and an effect can be obtained on safety and comfort.

According to a third aspect of the present invention, in the first or second aspect, a small hole, a perforation or a slit is provided at a predetermined location where the rupture occurs. Therefore, the predetermined portion can be defined more clearly, and the rupture can be caused more reliably.

According to a fourth aspect of the present invention, the sewing machine according to any one of the first to third aspects, wherein the sewing thread has a thickness, a strength, a sewing interval, a small hole, and a sewing machine. Since the size or setting interval of the eyes or slits is not uniform depending on the location, or is changed stepwise or continuously, the partial mechanical strength of the ventilation hole also changes stepwise or continuously depending on the place. . Thus, the opening area of the vent increases stepwise or continuously as the gas pressure increases. Therefore, according to this means, the opening area can be set more appropriately in accordance with the gas pressure in the bag, and thus, the gas pressure in the bag can be more stably maintained.

According to a fifth aspect of the present invention, in the first aspect, a plurality of ventilation holes are provided. As a result, even when the air holes have the same structure, the air holes may open or expand when the airbag is deployed or when the occupant collides with the airbag, and may not open or expand. The ratio of the number of openings or expanding vents to the number of openings and non-expanding vents depends largely on the gas pressure in the bag. That is, the higher the gas pressure in the bag, the larger the ratio of the number of vent holes that are opened or expanded. Therefore, by this means, the number of vents that open or expand according to the gas pressure in the bag can be changed, and by this action, the total opening area contributed by all the vents of the airbag is reduced by May change stepwise or continuously depending on the gas pressure of the gas. Therefore, according to this means, it is possible to more stably maintain the gas pressure in the bag.

According to a sixth aspect of the present invention, in the means of the fifth aspect, the gas pressure at the critical point at which the opening of the vent hole or the opening area is started is provided in the same airbag. And at least one or more air holes different from the gas pressure at the critical point of the other air holes. This makes it possible for the means described in claim 5 to function more reliably. Also, when using a multi-stage inflator with a multi-stage ignition device, the total opening area of the vent can be changed stepwise according to the gas pressure in the bag,
Therefore, it is possible to more stably maintain the gas pressure in the bag.

Further, according to the means described in claim 7, in the means described in any one of claims 1 to 6, the ventilation hole is provided together with the ventilation hole whose opening area is not variable. Thus, the initial value of the total opening area of the vent is
Obviously, it is a certain finite constant value larger than zero. Therefore, by using this means, it is possible to obtain an effect equal to or more than that of the means described in claim 2 by an operation substantially equivalent to the means described in claim 2.

According to the means described in claim 8, in the means described in any one of claims 1 to 7, the airbag has a double structure and is located inside the airbag. A vent is provided in the inner bag. As a result, the inner bag can be rapidly deployed and, at the same time, the gas pressure in the inner bag can be more stably maintained.In the airbag located outside the inner bag,
A more stable and averaged gas pressure gas can be supplied. Therefore, the deployment speed, deployment order and deployment form of the airbag can be made more secure. Also, particularly when using a multi-stage inflator, a gas having a more stable and averaged gas pressure is supplied into an airbag located outside the inner bag in accordance with the stepwise change of the gas pressure in the inner bag. Will be able to supply.

According to a ninth aspect of the present invention, the inflator according to any one of the first to eighth aspects, wherein the inflator is operated in a simultaneous ignition mode in which all the inflators are ignited simultaneously. At least one of the partial ignition modes in which only some of the inflators are ignited, or at least one of the delayed ignition modes in which at least one inflator is ignited later than the first inflator It becomes a multi-stage inflator with an ignition device. This makes it possible to change the number of inflators to be fired according to the speed and deceleration at the time of the vehicle collision or the physique of the occupant, and to supply gas more stably and evenly in the airbag, According to the means described in any one of claims 1 to 8, it is possible to bring out the operation and effect corresponding to the multi-stage inflator.

Further, according to the means of claim 10,
The means according to claim 9, wherein the multi-stage inflator comprises:
It is a two-stage type, and the gas pressure of the gas generated from the inflator that is ignited later is higher than the gas pressure of the gas generated from the inflator ignited first. Thus, when the air hole is provided in the body of the airbag, when the low-pressure inflator is ignited first, the opening area is small, so that the amount of gas exhausted to the outside of the airbag is suppressed, and the deployment time is shortened. At the same time, and more reliably avoids the bottoming phenomenon of the bag. Also, when the high-pressure inflator is activated, the opening of the air hole is enlarged due to the collision of the occupant. Contributes to stable absorption of kinetic energy. In addition, when the above-described vent is provided in the inner bag, the opening area of the vent changes according to the stepwise change of the gas pressure in the inner bag when the high pressure and the low pressure inflators are operated (enlargement). I do. As a result, a gas with a more stable and averaged gas pressure can be supplied into the airbag located outside the inner bag. Therefore, the deployment speed, deployment order and deployment form of the airbag can be made more secure.

According to the eleventh aspect of the present invention,
11. The means according to any one of claims 1 to 10, wherein the closing cloth or the reinforcing cloth is made of a material having a lower mechanical strength than the base cloth, such as a thin cloth, a thin rubber, a chemical resin, and paper. Is done. Thereby, the mechanical strength of the closing cloth or the reinforcing cloth can be adjusted and set more flexibly and optimally with more adjusting elements. In addition, according to this means, it is not necessary to provide small holes, perforations or slits at predetermined locations where the closing cloth or the reinforcing cloth is ruptured, so that the number of manufacturing steps can be reduced. With the above means, the above-mentioned problem can be solved.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described based on specific embodiments. (First Embodiment) As shown in FIG.
9 (a), it is deployed to protect the occupant in the front passenger seat. As shown in FIG.
Has a ventilation hole having the structure shown in FIG. FIGS. 1A and 1B are plan views (a) and (c) and cross-sectional views (b) and (d) showing a structure and an opening shape of a ventilation hole according to a first embodiment of the present invention.
(A) and (b) show the structure and opening shape of the main vent before the inflator is activated. The base fabric 100 has a substantially circular vent opening 130, and the vent opening 130
Is covered with a closing cloth 110 which also serves as a substantially circular reinforcing cloth larger than the ventilation hole opening 130.
The sewing cloth 140 is sewn with a sewing thread 140 at a predetermined sewing position located around the ventilation hole opening 130 (FIGS. 1A and 1B). The closing cloth 110 is
A substantially circular vent hole opening 120 is provided at substantially the center thereof, and the diameter of the vent hole opening 120 is equal to the above-described vent hole opening 13.
The aperture is set smaller than 0. Main closing cloth 110
Are arranged so as to form substantially concentric circles. From the side of the periphery of the air hole opening 120 of the main closing cloth 110, a perforation 111 is provided on the radiation starting from the center of the above substantially concentric circle to a position reaching the circumference of the air hole opening 130. (Figure 1
(A)). The eight perforations 111 are provided at intervals of about 45 ° with respect to the center.

When the gas pressure of the gas generated in the bag by the ignition or explosion of the inflator exceeds a certain value, the above-mentioned ventilation hole is provided with a perforation 111 provided in the closing cloth 110.
As shown in FIGS. 1C and 1D, the opening / closing section 112 is turned up by the rupture in the vicinity, so that the ventilation hole opening 1 is formed.
Open up to 30. By configuring the ventilation holes of the airbag as described above, the present airbag device can obtain at least the above-described functions and effects by the means described in claims 1 to 3. For example, a case will be described in which the present vent is applied to a single-layer airbag having a two-stage inflator as shown in FIG. 9A. In such a case, if only one inflator is ignited by a low-speed vehicle collision, the gas pressure in the airbag does not become high. Therefore, even when the occupant collides with the airbag, the opening area variable mechanism of the air hole does not operate. As a result, the amount of exhaust air from the ventilation holes is relatively suppressed, so that the bottoming phenomenon of the airbag by the occupant is avoided. Also, if two inflators are ignited by a high-speed vehicle collision, the gas pressure in the airbag becomes high, and in the event of a collision with an occupant, the opening area variable mechanism of the main ventilation hole acts to allow the main ventilation hole to pass through. It opens to the pore opening 130. As a result, a large amount of exhaust air per unit time from the ventilation hole is secured, so that the rebound phenomenon of the occupant due to the airbag can be avoided and the kinetic energy of the occupant can be stably absorbed.

(Second Embodiment) FIG. 2 is a side view (a) of an airbag apparatus according to a second embodiment of the present invention, and a plan view (b) and a cross-sectional view (c) showing the structure of a ventilation hole. . The airbag has a double structure as shown in FIG. 2 (a), and the base fabric 200 of the inner bag located inside the airbag is shown in FIG.
Vent holes having the structure shown in (b) and (c) are provided at a plurality of locations. The inner bag is intended to prevent the occupant from being hit by the rapid deployment of the airbag and control the deployment form with high safety by controlling the deployment speed, deployment direction or deployment sequence of the airbag. Base cloth 200
Has a substantially circular vent opening 130, and the vent opening 130 is covered with a closing cloth 110 which also serves as a substantially circular reinforcing cloth larger than the vent opening 130. 200 and the closing cloth 110 are connected to the vent opening 13.
It is sewn by a sewing thread 140 at a predetermined sewing position located around 0. The closing cloth 110 has a substantially circular vent hole opening 210 (or 220) at substantially the center thereof, and the diameter of the vent hole opening 210 (or 220) is larger than the diameter of the above-described vent hole opening 130. Is also set small. Outer perimeter of main closing cloth 110 and vent opening 13
0, 210 (or 220) are arranged so as to form substantially concentric circles.
From the periphery of 0 (or 220), the vent holes 130 are formed radially outward from the center of the above-mentioned substantially concentric circles at a total of four points at intervals of about 90 ° with respect to this center.
The slit 113 is provided up to a position reaching the circumference of FIG. 2 (FIG. 2B).

The slit 113 is sewn with a sewing thread 114 so as to approach the original state before the formation of the main slit, whereby the main vent is formed with a gas pressure of gas generated in the inner bag. When the value exceeds a certain value, the sewing thread 114 breaks and opens up to the vent opening 130. By configuring the ventilation holes of the airbag as described above, the present airbag device can obtain at least the above-described functions and effects by the means described in the first, second, and eighth aspects. For example, a case will be described in which the airbag apparatus of FIG. 2 includes a two-stage inflator. When it is determined that only one-stage ignition is required, the vent openings 210 and 220 control the gas flow in this state to allow the main bag to be deployed well. Then, when it is determined that the two-stage simultaneous ignition is performed, the vent hole is expanded at a predetermined gas pressure, and the main body bag is satisfactorily deployed by desired gas flow control.

The case where the airbag apparatus of FIG. 2 is provided with a two-stage inflator having a delayed ignition mode will be described. When the present airbag is deployed, first, in order to secure a deployment trajectory of the high-pressure gas, a low-pressure inflator that particularly deploys the inner bag as shown in FIG. 2A is ignited. The reason why the low-pressure inflator is used is that the volume of the inner bag is relatively small with respect to the volume of the entire airbag, and that the main bag (outer bag) is not rapidly protruded by the expansion force of the inner bag. . At this stage, in order to deploy the inner bag as quickly as possible, the smaller the opening area of the vent holes 210 and 220, the better.
Since 0 is closed off by the base cloth 100, it is not necessary to close it at all. Rather, it is more desirable to open it small in order to secure the deployment trajectory of the high-pressure gas to some extent. Next, when the inner bag is deployed as shown in FIG. 2A, the high-pressure inflator is exploded.
At this stage, in order to deploy the base fabric 100 as quickly as possible, it is preferable that the opening areas of the vent openings 210 and 220 be large. However, the size of the ventilation hole opening 130 of this ventilation hole is limited by the fact that this ventilation hole is used to regulate the direction of gas flow injection. Is set to an appropriate size that satisfies the condition of When the high-pressure inflator explodes, the above-mentioned opening area variable mechanism operates by the action of the high-pressure gas when the high-pressure inflator explodes. Due to these actions and effects, the airbag is deployed safely and rapidly. In the present embodiment, the first stage is a low-pressure multi-stage inflator and the second stage is a high-pressure multi-stage inflator. However, the gas pressure of both is not limited to this, and an inflator having substantially the same pressure may be prepared. . The same effect can be obtained even at a slightly higher pressure in the first stage.

(Third Embodiment) The present embodiment is implemented by the means described in claim 3, and the structure of the ventilation hole of the present embodiment is the same as that of the airbag body (base cloth) of the first embodiment. 10
0) or the inner bag (base cloth 20) of the second embodiment.
The present invention can be applied to any of the bags 0). FIG.
FIGS. 7A and 7B are a plan view and a cross-sectional view illustrating a structure of a vent according to a third embodiment of the present invention. The structure of this vent is
It is similar to the structure of the vent hole in the second embodiment. That is, the mechanism for changing the opening area of the ventilation hole in the present embodiment is shown in FIG.
The slit 113 and the sewing thread 114 of the ventilation hole shown in FIG.
Is replaced by an opening area variable mechanism with small holes 115 shown in FIGS. 3 (a) and 3 (b). The opening area of this air hole is such that the small holes 115
By providing at 0, the constriction 116 formed between the periphery of the vent hole opening 120 and the small hole 115 is ruptured and expanded. By configuring the ventilation holes as described above, if the main ventilation holes are provided at the same locations as the airbag body (base cloth 100) of the first embodiment, the same operation and effect as those of the first embodiment can be obtained. be able to. Further, by forming the ventilation holes as described above, if the main ventilation holes are provided at the same location as the inner bag (base fabric 200) of the second embodiment, at least claims 1 to 3 and claims are provided. The above-described functions and effects of the means described in Item 7 can be obtained.

(Fourth Embodiment) The present embodiment is implemented by the means described in claim 3, and the structure of the ventilation holes of the present embodiment is the same as that of the airbag body (base cloth) of the first embodiment. 10
0) or the inner bag (base cloth 20) of the second embodiment.
The present invention can be applied to any of the bags 0). FIG.
FIGS. 7A and 7B are a plan view and a cross-sectional view showing a structure of a vent according to a fourth embodiment of the present invention. The structure of this vent is
This is very similar to the structure of the vent hole in the first embodiment. That is, the air holes are the air holes of the first embodiment (FIG. 1A,
The opening / closing section 112 is formed by expanding the opening of the ventilation hole of the base cloth of (b)) toward the center of the circumference thereof and overlapping the closing cloth 110.
Is expanded to a double structure. The perforation 111 is
Although it is provided at a total of eight positions at the same position as the first embodiment, the closing cloth 110 is provided only in the vertical and horizontal directions shown in FIG. 4A, and the base cloth 100 (or 200) is provided only in the diagonal direction. Four places are provided. By configuring the ventilation holes as described above, if the main ventilation holes are provided at the same locations as the airbag body (base cloth 100) of the first embodiment, the same operation and effect as those of the first embodiment can be obtained. be able to. Further, by forming the ventilation holes as described above, if the main ventilation holes are provided at the same location as the inner bag (base fabric 200) of the second embodiment, at least claims 1 to 3 and claims are provided. The above-described functions and effects of the means described in Item 7 can be obtained.

(Fifth Embodiment) This embodiment is carried out by the means described in claim 4, and the structure of the ventilation hole of this embodiment is the same as that of the airbag body (base cloth) of the first embodiment. 10
0) or the inner bag (base cloth 20) of the second embodiment.
The present invention can be applied to any of the bags 0). FIG.
FIGS. 7A and 7B are a plan view and a cross-sectional view, respectively, showing a structure of a vent according to a fifth embodiment of the present invention. Vent opening 130 and closing cloth 11 provided in base cloth 100 (or 200)
0 is formed in a substantially circular shape, and the outer periphery of the closing cloth 110 and the ventilation hole opening 130 are arranged so as to form a substantially concentric circle. The main closure cloth 110 is provided with a slit 117 and a perforation 111 on the radiation starting from the center of the above-mentioned substantially concentric circle to a position reaching the periphery of the vent hole opening 130 (FIG. 5A). . The slits 117 and the perforations 111 are provided at a total of eight locations at intervals of about 45 ° with respect to the center. That is, the vent opening 13
A total of eight slits 117 are provided on each of the above-mentioned radiations, excluding the central part thereof, up to a position substantially reaching the circumference of the vent hole opening 120 located inside the circumference of 0. The perforation 111 is provided to a position reaching the periphery of the vent hole opening 130.

When the gas pressure of the gas generated in the bag by the ignition or explosion of the inflator exceeds a first fixed value, the vent hole is first opened and closed by the rupture of the central portion of the closing cloth 110. The part 112 is opened by being turned up to a position reaching the substantially circumference of the vent hole opening part 120.
When the gas pressure further rises and exceeds the second fixed value, the opening / closing portion 112 is further rolled up due to the rupture near the perforation 111 provided on the closing cloth 110, so that the main ventilation hole becomes the ventilation hole opening portion 130. Open to the point. By arranging the air holes as described above, if the air holes are provided at the same positions as those of the airbag body (base cloth 100) of the first embodiment, at least claims 1, 3, and 4 will be described. The operation and effect described above can be obtained by the means described in (1). Also, by configuring the ventilation holes as described above,
If the main ventilation hole is provided at the same place as the inner bag (base cloth 200) of the second embodiment, at least the above-mentioned actions and effects by the means of claim 1, claim 3, claim 4, and claim 7 can be obtained. The effect can be obtained.

This air hole is provided in an airbag apparatus having a two-stage inflator in which the gas pressure of the gas generated from the inflator fired later is higher than the gas pressure of the gas generated from the inflator fired first. When adopted, the main vent is opened to a position reaching substantially the circumference of the vent opening 120 when the inflator to be ignited first is activated, and when the inflator to be ignited later is activated, It is opened to a position reaching the periphery of the vent opening 130. Therefore, in this case, it is possible to further obtain at least the above-described functions and effects by the means described in claim 9 or claim 10.

(Sixth Embodiment) This embodiment is implemented by the means described in claim 4. FIG. 6 (a) is a plan view showing the structure of a ventilation hole according to a sixth embodiment of the present invention.
And a sectional view (b). This air hole is a modified example of the air hole in the fifth embodiment. That is, the opening area variable mechanism of the present vent is provided by providing a row of small holes 118 and 119 composed of a large number of small holes at the same position as the position where the slit 117 and the perforation 111 of the fifth embodiment are provided. It is configured. As shown in FIG. 6A, the small hole rows 118 are arranged in the vertical and horizontal directions of the closing cloth 110,
The size of each small hole is set so as to gradually increase as the position approaches the center of the closing cloth 110.
Therefore, the small hole located at the center is the largest. The small hole rows 119 are arranged in the oblique direction of the closing cloth 110, and the size of each small hole is the same, but the set interval is gradually narrowed as approaching the center of the closing cloth 110.

With the above configuration, the closing cloth 11 of the main air hole is provided.
The mechanical strength of 0 is set so as to gradually decrease as it approaches the center. With this opening area variable mechanism, the opening area of the main vent increases continuously as the maximum gas pressure over time in the bag increases. That is, the opening area of the main vent is automatically and continuously selected according to the gas pressure in the bag. Therefore, by configuring the structure of the air hole provided in the airbag device as the main air hole, at least claims 1 to 4
The operation and effect described above can be obtained by the means described in (1).

(Seventh Embodiment) This embodiment is implemented by the means described in claim 5 or claim 6.
FIG. 7 is a plan view (a) and a sectional view (b) showing the structure of a vent according to a seventh embodiment of the present invention. This air hole is very similar to a structure in which two air holes (FIGS. 9 (b) and 9 (c)) according to the prior art are arranged so as to be adjacent to each other. That is, as shown in FIGS. 7A and 7B, the main ventilation holes are provided at the base cloth 100 (or 200) with two substantially circular ventilation hole openings 130 close to each other with a slight space therebetween. The two ventilation hole openings 130 are entirely covered with a single oblong cloth 110. The edges around the two ventilation hole openings 130 are sewn to the closing cloth 110 by sewing threads 140. The closing cloth 110 is provided with one cross-shaped slit 113 so that the cross-shaped intersection substantially coincides with the center of the two ventilation hole openings 130. The slit 113 is sewn with a sewing thread 114, and the main sewing thread 114 breaks when the gas pressure inside the airbag exceeds a predetermined value. By configuring the structure of the air hole provided in the airbag device like the main air hole, at least the above-described operation and effect by the means according to claim 5 can be obtained.

Further, by changing the thickness, strength or sewing interval of the sewing thread 114 between the two cross-shaped slits 113, it is possible to set the mechanical strength of the two ventilation holes to be different from each other. Become. Therefore, it is possible to set different gas pressures in the bag at which the two vent holes start opening. Thereby, at least the above-described functions and effects by the means described in claims 5 and 6 can be obtained.

(Eighth Embodiment) This embodiment is implemented by the means described in claim 7. FIG. 8 is a plan view showing the structure of a vent according to an eighth embodiment of the present invention.
And a sectional view (b). This ventilation hole is similar to the structure of the ventilation hole in the seventh embodiment, but differs from that of the seventh embodiment in that one of the ventilation holes is not provided with a variable opening area mechanism. That is, one of the ventilation holes is not provided with a cross-shaped slit 113, and instead, a ventilation hole opening 120 substantially congruent with the ventilation hole opening 130 is formed in the closing cloth 11.
0, that is, at a position overlapping with the ventilation hole opening 130. By configuring the structure of the air hole provided in the airbag device like the main air hole, at least the above-described functions and effects of the means according to claim 7 can be obtained.

(Ninth Embodiment) In this embodiment, the means of claim 8 is implemented by the means of claim 6. That is, in this embodiment, in the inner bag shown in FIG. 2A, the upper air hole opening 220 is formed using the air hole shown in FIG. 5, and the lower air hole opening 210 is formed as the air hole shown in FIG. It is configured using. With this configuration, the vent hole of FIG. 1 has the opening 120 from the beginning, so that the bag body can be firstly deployed downward. Thereafter, when the inner pressure of the inner bag rises, the upper ventilation hole is first opened to the opening 120, so that the upward deployment is started with a delay. When the gas pressure further rises, the upper and lower ventilation holes open up to the opening 130,
By these action mechanisms, the main body bag is deployed in a desired deployment order. By configuring the structure of the ventilation hole provided in the airbag device in this manner, at least the above-described functions and effects of the means according to claims 6 and 8 can be obtained.

In all of the above embodiments, the material forming the closing cloth or the reinforcing cloth is not particularly mentioned, but the material forming the closing cloth or the reinforcing cloth is not necessarily the same as the base cloth forming the bag. It is not necessary to use a material having a lower mechanical strength than the base fabric, such as a thin cloth, a thin rubber, a chemical resin, and paper. Thereby, the means according to claim 11 can be implemented, and thus, the operation and effect of the means according to claim 11 can be achieved such that the opening of the ventilation hole having a variable opening area can be more reliably implemented. Can be obtained.

[Brief description of the drawings]

FIG. 1 is a plan view (a), (c) and a cross-sectional view (b) showing the structure and opening shape of a vent according to a first embodiment of the present invention;
(D).

FIGS. 2A and 2B are a side view of an airbag apparatus according to a second embodiment of the present invention, a plan view showing a structure of a ventilation hole, and a sectional view of FIG.

FIG. 3 is a plan view (a) and a cross-sectional view (b) showing a structure of a vent according to a third embodiment of the present invention.

FIG. 4 is a plan view (a) and a cross-sectional view (b) showing a structure of a vent according to a fourth embodiment of the present invention.

FIGS. 5A and 5B are a plan view and a cross-sectional view showing a structure of a vent according to a fifth embodiment of the present invention.

FIGS. 6A and 6B are a plan view and a cross-sectional view illustrating a structure of a ventilation hole according to a sixth embodiment of the present invention.

FIGS. 7A and 7B are a plan view and a cross-sectional view illustrating a structure of a vent according to a seventh embodiment of the present invention.

8A and 8B are a plan view and a cross-sectional view illustrating a structure of a vent according to an eighth embodiment of the present invention.

FIG. 9A is a side view of an airbag device having a vent according to the related art, and FIG. 9B is a plan view showing the structure of the vent.
And a sectional view (c).

[Explanation of symbols]

 REFERENCE SIGNS LIST 100 base cloth 110 closing cloth or reinforcing cloth 120 ventilation opening (initial) 130 ventilation opening (after enlargement) 140 sewing thread 200 inner bags 210, 220 ventilation opening (initial) 300 … Airbag storage case 400… inflator 500… body

Claims (11)

[Claims] An airbag formed in a bag shape having a single or double structure by connecting a base fabric and having a vent hole for exhausting a part of gas generated from an inflator to the outside of the base fabric, The opening area of the pore may be a predetermined location of the base cloth, or a predetermined location of a closing cloth or reinforcing cloth provided at the opening of the ventilation hole, or the base cloth, the closing cloth or the reinforcement. An airbag device characterized by changing according to the pressure of gas in the airbag due to breakage of a sewing thread for sewing a predetermined portion of the cloth. 2. The airbag device according to claim 1, wherein the change in the opening area of the ventilation hole is an increase from a certain finite constant value that is obviously larger than zero. 3. The airbag device according to claim 1, wherein a small hole, a perforation, or a slit is provided at the predetermined location where the rupture occurs. 4. The thickness, strength, or sewing interval of the sewing thread, or the size or setting interval of the small hole, the perforation, or the slit is made non-uniform depending on the location, or stepwise or continuous. The opening area of the ventilation hole increases stepwise or continuously as the pressure of the gas in the airbag increases by changing the pressure to the air pressure. Item 12. The airbag device according to item 1. 5. The airbag device according to claim 1, wherein the airbag device has a plurality of air holes. 6. The method according to claim 1, wherein the gas pressure at a critical point at which the opening of the vent or the opening area of the vent is started is different from the gas pressure at the critical point of another vent provided in the same airbag. The airbag device according to claim 5, wherein at least one airbag device is provided. 7. The airbag device according to claim 1, wherein the ventilation hole is provided together with a ventilation hole whose opening area is not variable. 8. The airbag according to claim 1, wherein the airbag has a double structure, and the ventilation hole is provided in an inner bag located inside the airbag. An airbag device according to claim 1. 9. The inflator may be a simultaneous ignition mode in which all inflators are ignited simultaneously, a partial ignition mode in which only some inflators are ignited, or an inflator in which at least one inflator is ignited first The air according to any one of claims 1 to 8, wherein the air is a multi-stage inflator using an ignition device having at least one ignition mode among delayed ignition modes in which ignition is performed later than the ignition mode. Bag device. 10. The multi-stage inflator is of a two-stage type, in which a gas pressure of a gas generated from a subsequently ignited inflator is larger than a gas pressure of a gas generated from a previously ignited inflator. The airbag device according to claim 9, wherein: 11. The closing cloth or the reinforcing cloth is made of a material having a lower mechanical strength than the base cloth, such as a thin cloth, a thin rubber, a chemical resin, and paper. The airbag device according to any one of claims 1 to 10.