JP2002254999A - Air bag - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an air bag offering simple construction for an inflated and developed configuration permitting stable and accurate shock absorption and support of an occupant during inflation and development. SOLUTION: The vertical length of an internal bag portion 7 of the air bag 6 is greater than the vertical length of an external bag portion 8 corresponding thereto. When a high pressure gas generated from a gas supply source 5 is introduced from a gas inlet 7a, where the opening end of the internal bag portion 7 is closed and fixed to the opening end of the external bag portion 8, into the front end of the internal bag portion 7 longer in the vertical direction, the front end of the internal bag portion 7 only jumps out in the inflow direction of the gas, the amount of inflation toward the occupant is restricted and inflation in the vertical direction is actively performed. The high pressure gas flows into the external bag portion 8 while restricting the flow of the high pressure gas to the vertical direction of the internal bag portion 7. During the inflation and development of the air bag 6, while the longitudinal movement to the side of the occupant is oppressed to minimize the inflation and development of the air bag 6 to the side of the occupant, the inflation and development surface of the air bag 6 is enlarged almost parallel to the occupant. Impact which the occupant receives is reduced with no abrupt inflation toward the occupant who is moved forward in forward tilting attitude by the impact.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an airbag which can be inflated and deployed at the time of a vehicle collision to reliably and effectively protect an occupant.

[0002]

2. Description of the Related Art Conventionally, when a vehicle receives a large impact, the impact is sensed and high-pressure gas from an inflator is introduced into an airbag, and the airbag is instantly inflated and deployed in a proper form. Various airbag devices have been put to practical use that cushion the upper body of the occupant with the airbag and significantly reduce the impact force applied to the human body. This airbag device is mounted as standard equipment not only on the center of a steering wheel in front of a driver but also on an instrument panel or the like in front of a passenger seat.

[0003] The occupant protection performance of this airbag device is greatly affected by the inflation speed of the airbag itself, the form of inflation and the like, and various airbags have been proposed in the past. As an example of this airbag, it has been proposed to provide, for example, an inner bag inside an airbag main body and form a blowout hole in the inner bag to control the inflation and deployment mode of the airbag.

[0004] An example of this type of airbag device is disclosed in, for example, Japanese Patent Application Laid-Open No. 10-203280. The passenger seat airbag device disclosed in the publication accommodates an inner bag formed separately from the airbag body inside the airbag body, and a part of each bag is generated from an inflator. It is composed of two outer bags and an inner bag having openings (gas inlets) for introducing high-pressure gas, and the gas inlets of the airbag body and the inner bag are connected to an inflator storage case via a retainer. And tightly closed.

[0005] The airbag main body is formed by three-dimensionally sewing two side cloths forming left and right side surfaces thereof and one central cloth which stitches the left and right side cloths. The one inner bag is made of three cloth materials, two side cloths and one central cloth, like the airbag body.
The inner bag has a similar three-dimensional shape in which the front and rear and up and down dimensions are smaller than the airbag body, the left and right dimensions are substantially the same as the airbag body, and the capacity is smaller than the airbag body. have.

The upper and lower portions of the central cloth facing the occupant-facing side of the inner bag are provided with a high pressure generated from the inflator after the inner bag is deployed in order to promote the vertical deployment of the airbag body. A gas blowing hole for blowing gas into the airbag body is formed. Further, in order to promote the deployment of the airbag body in the left-right direction, gas blowing holes are also formed in each side cloth of the inner bag.

When the airbag is inflated and deployed, the upper and lower surfaces of the inner cloth of the inner bag are sandwiched between the upper surface of the instrument panel and the windshield by high-pressure gas from the inflator, and The upper part of the instrument panel and the windshield are deployed in a deployed form that occupies substantially the upper space of the instrument panel whose cross section is substantially triangular, and the bulging surface on the occupant-facing side is the occupant-facing surface of the instrument panel. The airbag body is slightly inflated toward the occupant from the airbag body, and the airbag body is moved further toward the occupant side beyond the instrument panel by the high-pressure gas supplied through the gas blowing hole of the deployed inner bag. It expands and expands in the form of

In the conventional passenger airbag device, when the airbag device is inflated and deployed to protect the occupant in the passenger seat as described above, the space above the instrument panel is filled with the inner bag early. Since the inner bag is sandwiched between the upper surface of the instrument panel and the windshield while maintaining the internal pressure, the inner bag does not shake in the airbag body, and the air flows from the gas outlet of the inner bag. It is said that the high-pressure gas flow supplied into the bag body is stabilized, and stable deployment behavior of the airbag is obtained.

Further, since the bulging surface of the inner bag on the occupant-facing side slightly swells from the instrument panel toward the occupant, it is possible to ensure the flow direction of the high-pressure gas flow blown from the inner bag. This has the advantage of promoting the deployment of the lower part of the airbag body, and the like.

[0010]

SUMMARY OF THE INVENTION The above-mentioned Japanese Patent Application Laid-open No. Hei 10-2
The airbag for the passenger seat disclosed in Japanese Patent No. 03280,
When the airbag is inflated and deployed, as described above, the space above the instrument panel, whose cross section between the upper surface of the instrument panel and the windshield is substantially triangular, is filled with the inner bag at an early stage. The bag body is positively held in the upper space of the instrument panel.

For this reason, in the initial stage of the inflation and deployment of the airbag, the airbag is deployed into a deployed form occupying the space above the instrument panel by the high-pressure gas introduced from the inflator into the interior of the inner bag. The bulging surface on the opposite side immediately expands and deploys backward from the rear surface of the instrument panel. The high-pressure gas ejected from the plurality of gas outlets of the inner bag formed along the gas flow direction passes over the rear surface of the instrument panel and further in the front-back, up-down, and left-right directions of the airbag body. And the front, back, top and bottom and left and right sides of the airbag body are directly subjected to excessive gas pressure. As a result, the airbag body is inflated substantially in the same direction as the inflation direction of the inner bag, and immediately tries to inflate toward the occupant-facing side that is moving forward in a forwardly inclined posture by an impact.

[0012] Even when the airbag device is installed in a location such as an upper surface of an instrument panel or the like in front of the passenger seat and where the space in front of the occupant is large, the occupant may be placed in the airbag device. When the airbag is inflated and deployed, the airbag is inflated and deployed toward the front of the room when the airbag is inflated and deployed. May not be available. Even when the occupant is approaching the airbag device, the airbag is inflated and deployed over a wide range of left, right, up and down, and then inflated and deployed toward the occupant opposite side, thereby effectively mitigating the impact applied to the occupant. It is desirable.

The present invention has been made to solve the above-mentioned conventional problems, and a specific object of the present invention is to provide an inflatable structure which has a simple structure and can stably and accurately cushion and support an occupant when inflated and deployed. An object of the present invention is to provide an airbag capable of obtaining a deployed form.

[0014]

The invention according to claim 1 of the present invention is directed to an inner bag portion and an outer bag portion having a common gas introduction port for introducing gas generated from a gas supply source at a substantially central portion. An airbag having a multi-bag structure having the air bag, wherein the length of at least one direction of the inner bag portion is set to be longer than the corresponding length of the outer bag portion in one direction. In the bag.

The airbag of the present invention has a multi-bag structure having an inner bag portion and an outer bag portion. For example, the opening peripheral portion of the inner bag portion is hermetically fixed to the opening peripheral portion of the outer bag portion. It has a common gas inlet for introducing high-pressure gas generated from a gas supply source. When the vehicle receives a large impact of a predetermined magnitude or more, the impact is sensed to activate the gas supply source, high-pressure gas is introduced into the inner bag portion from the gas introduction port, and the entire airbag is inflated.

In the initial stage of inflation of the airbag,
First, high-pressure gas is introduced from the gas inlet into the inner bag portion. As a result, the high-pressure gas spreads toward the tip of the inner bag portion that is longer in at least one direction, and the inner bag portion is inflated and deployed. At this time, the outer bag portion attempts to expand in the up and down direction while suppressing the expansion in the left and right direction by the inflating and deploying operation of the inner bag portion.

Therefore, in the initial stage of the inflation of the airbag, the length of the inner bag portion protrudes in the lengthwise direction by a long length, and the amount of inflation toward the occupant is regulated. And / or positive expansion in the vertical direction.
The high-pressure gas introduced into the inner bag portion flows out into the outer bag portion while regulating the flow direction of the high-pressure gas in at least one length direction of the inner bag portion. Both the outer bag portion and the outer bag portion are gently and safely inflated and deployed.

In the initial stage of the inflation and deployment of the airbag, the movement of the airbag toward the occupant in the front-rear direction can be suppressed, and the inflation and deployment of the airbag to the occupant side can be minimized. The expansion and deployment in the left-right direction and / or the up-down direction can be smoothly expanded. Since the high-pressure gas is discharged in the direction in which the length of the inner bag portion is long in the initial operation of the inflation and deployment of the airbag,
The occupant is cushioned and supported by a wide inflating surface substantially parallel to the occupant moving forward in the forward leaning posture without suddenly inflating and compressing the occupant moving forward in the forward leaning posture due to the impact.

With the above configuration, even when the airbag is installed in a region where the front space of the occupant is large, such as an instrument panel in front of the passenger seat, a wide area in the left / right and / or up / down directions in the room is provided. Thus, the inflated surface of the airbag can be sufficiently obtained, and the occupant protection characteristics can be significantly improved with a simple structure.

According to a second aspect of the present invention, a gas for introducing gas introduced from the gas inlet into the outer bag is provided at both ends in the one direction of the inner bag with the gas inlet interposed therebetween. It is characterized by having a blowing hole.

According to this invention, since the gas outlets are provided at both ends in one direction which are longer than the gas inlet of the inner bag portion, the high pressure introduced into the inner bag portion first. The gas is discharged into the outer bag through the gas outlets formed at both ends of the inner bag most distant from the gas inlet of the inner bag with a certain time difference from the time of gas introduction. The introduction of gas causes the outer bag to
Or, it expands over a wide range up and down.

When the airbag is inflated and deployed, the gas is discharged from the most distant ends of the inner bag portion through the gas blowing holes into the outer bag portion. Until the entire folded inner bladder is inflated, the outer bladder does not directly participate in the inflation, eliminates sudden inflation toward the occupant moving forward in a forward leaning position by impact, and moves up and down and / or left and right as described above. After inflating in the direction, the outer bag part expands positively and spreads on a wide inflating surface substantially parallel to the occupant. Effectively obtained.

According to a third aspect of the present invention, the outer bag portion and the inner bag portion have a substantially central portion on the occupant-facing surface side in close contact with each other, and a peripheral portion of the gas introduction port of the outer bag portion is the inner bag. It is characterized by being folded in a loose state on the back side of the part.

According to the present invention, the outer bag portion and the substantially central portion of the inner bag portion on the occupant-facing surface side are overlapped with each other and are in close contact with each other, and the peripheral portion of the gas inlet of the outer bag portion is the inner portion. The bag is folded back with a slack on the back side.

A large amount of the high-pressure gas introduced into the inner bag portion flows into the inner bag portion from the initial stage of the inflation and deployment of the airbag, and the high-pressure gas flows between the outer bag portion and the inner bag portion. The inner bag portion is inflated and deployed in the direction in which the length of the inner bag portion is longer without almost flowing into the space, and the amount of protrusion of the outer bag portion toward the occupant-facing surface side can be reduced. At the time of inflation and deployment of the airbag, after the inflated form of the inner bag portion, the outer bag portion can be expanded over a wide range on the occupant-facing surface side, without delaying the pop-out timing of the outer bag portion. The occupant can be quickly buffered and supported.

According to a fourth aspect of the present invention, the inner bag portion has an elongated shape, and the one direction is the elongated direction,
The length in the elongated direction is set to be longer than the length in the corresponding direction of the outer bag portion, and at least one portion of the inner bag portion near the occupant facing surface at least one portion is narrowed down to a point. It is characterized by:

According to the present invention, for example, the inner bag portion has an elongated shape in the vertical direction, and the length of the elongated direction is set longer than the length of the outer bag portion in the corresponding direction. A substantially central portion of the inner bag portion on the occupant-facing surface side is sewn and narrowed into a point shape.

For example, when the airbag device mounted on the instrument panel is operated, the airbag is positively inflated and deployed downward by the windshield on the upper surface of the instrument panel, and the outer airbag is opened. Since the amount of protrusion of the bag portion toward the occupant-facing surface side is reduced,
The airbag can be inflated to a height corresponding to the abdomen from the occupant's chest without extremely inflating the height position of the occupant's neck by controlling the amount of inflation toward the occupant, The airbag cushions and supports the upper body of the occupant, greatly reducing the impact force applied to the human body. In the initial stage of the inflation and deployment of the airbag, the behavior in the front-rear direction can be suppressed, and the inflation and deployment surface of the airbag is substantially reduced with respect to the occupant while minimizing the inflation and deployment of the airbag in the front-rear direction. It can be enlarged in parallel.

[0029]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be specifically described below with reference to the accompanying drawings. FIG. 1 is a schematic view showing a deployed form of an exemplary embodiment of the present invention upon completion of inflation of an airbag, and FIG. 2 is a rear view of the airbag when the outer bag portion is spread out in a plane. FIG. 3 is a rear view when the inner bag portion of the airbag is expanded in a plane. The airbag device attached to the instrument panel in front of the passenger seat, the airbag device attached inside the front seat in front of the rear seat will be described as an example,
The present invention is not limited to this, and can be effectively applied to, for example, an airbag device mounted inside a door panel or the like.

In FIG. 1, an airbag device 1 applied to the present invention has an airbag lid (not shown) in an opening provided on an upper surface of an instrument panel (not shown) facing a passenger seat. It is covered and mounted. The airbag device 1 includes a lidless box-shaped retainer main body 3 having an inflator storage portion 3a and an airbag storage portion 3b, and a frame-shaped intermediate retainer 4 for partitioning the inflator storage portion 3a and the airbag storage portion 3b.
And a substantially cylindrical inflator 5 serving as a gas supply source housed in the inflator housing 3a.

The airbag 6, which is a feature of the present invention, is densely folded and accommodated in the airbag accommodating portion 3b. The airbag 6 has a double bag structure having an inner bag portion 7 and an outer bag portion 8. Each of the inner bag portion 7 and the outer bag portion 8 is formed by laminating two woven fabrics of, for example, nylon fibers, sewing the outer peripheral edges to each other, and connecting them in a bag shape having partially opened gas inlets 7a and 8a. It is integrated.

In the first embodiment, the outer peripheral portion of the inner bag portion 7 is formed from two pieces of cloth sewn to each other, but the present invention is not limited to this. For example, a single piece of cloth or the like obtained by connecting one side of the inner bag portion 7 may be used, and the outer bag portion 8 may be formed of a single piece of cloth or the like in the same manner as the inner bag portion 7.

The inner bag portion 7 is housed in the outer bag portion 8 through the gas inlet 8a, and the peripheral edge of the opening of the gas inlet 7a is sealed to the peripheral edge of the opening of the gas inlet 8a. A common gas inlet for fixedly introducing the high-pressure gas generated from the inflator 5 is formed. Since the common gas inlets 7a and 8a are provided, it is possible to prevent a reduction in strength due to the openings of the inner bag portion 7 and the outer bag portion 8. Further, since the common gas inlets 7a and 8a are closely adhered and overlapped, no gas is directly supplied from the gas inlets 7a and 8a to the outer bag portion 8.

When the airbag 6 is folded and housed in the airbag housing 3b, the inner bag 7 is inserted into the outer bag 8 through the gas inlet 8a in a conventional manner.
And the intermediate retainer 4 is inserted into the inner bag portion 7 from the gas introduction port 7a, and the intermediate retainer 4 is used to insert the gas introduction port into the periphery of the gas passage opening of the inflator storage section 3a. The peripheral edges of the openings 7a and 8a are pressed closely from the inside. Then, the peripheral edges of the gas introduction ports 7a and 8a are sandwiched and fixed between the intermediate retainer 4 and the peripheral edge of the gas passage opening of the inflator storage part 3a by stud bolts 2, and the airbag 6 and the intermediate part are fixed. The retainer 4 and the retainer 4 are integrally assembled in the airbag storage section 3b.

When the vehicle receives a large impact greater than a predetermined value, the impact is sensed and the inflator 5 is activated,
A high-pressure gas is introduced into the inner bag portion 7 from the gas inlet 7a, a tear line formed of a not-shown thin groove formed on the inner surface of the air bag grid is opened, the air bag grid is opened, and the air bag grid is opened and described later. As described above, the airbag 6 is inflated and deployed outside the instrument panel in a predetermined form.

The airbag 6 to which the present invention is applied provides the inner bag portion 7 contained in the outer bag portion 8 with a desired inflation / deployment form to maintain the inflation / deployment performance in a favorable manner. It is possible to effectively control the introduction timing and introduction direction of the introduced gas into the bag portion 8, the inflation speed of the entire airbag 6, the inflation deployment form, and the like. For this reason, the feature of the present invention lies in the structure and form of the airbag 6.

A preferred form of the airbag 6 has a simple multi-bag structure of the inner bag portion 7 and the outer bag portion 8, and a common gas inlet 7a for introducing gas from the inflator 5 as a gas supply source. It is important that the length of at least one direction of the inner bag portion 7 is set to be longer than the length of one direction corresponding to the outer bag portion 8 in addition to employing the airbag 6 having the outer bag portion 8a. It is.

As shown in FIGS. 2 and 3, the vertical length L1 of the inner bag portion 7 in the first embodiment is longer than the length L2 of the outer bag portion 8 in a state where the inner bag portion 7 is spread in a plane. In addition, the length L3 in the left-right direction orthogonal to the length L1 of the inner bag portion 7 is set shorter than the length L4 in the left-right direction of the outer bag portion 8. With this configuration, in the initial stage of inflation and deployment of the airbag 6, high-pressure gas from the inflator 5 is introduced in a direction in which the length of the inner bag portion 7 is long. At this time, the movement of the inner bag portion 7 toward the occupant in the front-rear direction is suppressed to minimize the inflation and deployment of the entire airbag 6 to the occupant-opposed side. A wide parallel expansion surface is obtained.

The outer bag portion 8 of the airbag 6 to which the present invention is applied has an inflator-facing base fabric 8b and an occupant-facing base fabric 8c of substantially the same shape. Each of the opposing base fabrics 8b and 8c has a substantially trapezoidal shape in a state where the base fabrics 8b and 8c are spread in a plane as shown in FIG. Around the gas inlet 8a formed substantially at the center of the inflator facing base fabric 8b, the inflator storage portion 3a
The same number of mounting holes 8d,..., 8d are formed at the same positions corresponding to the mounting holes (not shown) formed in the peripheral portion of the gas passage opening. Further, a pair of left and right circular shapes are formed above the gas inlet 8a of the inflator facing base fabric 8b so that when an external pressure acts on the inflated and deployed airbag 6, high-pressure gas in the airbag 6 is released. Vent holes 8e, 8e are formed. A reinforcing cloth is sewn on the inner periphery of the vent hole 8e.

The inner bag section 7 has an inflator-facing base cloth 7b and an occupant-facing base cloth 7c having substantially the same shape on the inflator-facing side, as shown in FIG. It has a substantially rectangular shape when it is spread out. A substantially rectangular gas inlet 7a and a plurality of mounting holes 7 corresponding to the installation positions of the gas inlet 8a and the mounting hole 8d of the outer bag portion 8 are provided at substantially the center of the inflator facing base cloth 7b.
,..., 7d are formed.

Each of the opposing base fabrics 7b, 7
The high-pressure gas introduced from the gas introduction port 7a of the inner bag portion 7 is allowed to flow into the outer bag portion 8 at the upper and lower end portions of the outer bag portion c at the outer peripheral edges on both the left and right sides of the tip portion. A pair of upper and lower slit-shaped gas blowing holes 7e, 7e are respectively formed. A pair of gas outlets 7e vertically adjacent to each other
Are arranged on the same straight line along the up and down direction with an interval capable of being torn by a predetermined tension when the airbag 6 is deployed.

The gas from the inflator 5 is discharged in a direction in which the length of the inner bag portion 7 is long, and is discharged into the outer bag portion 8 through a gas blowout hole 7e farthest from the inflator 5. Therefore, in the initial stage of the operation of the inflation and deployment of the airbag 6, the inflating surface substantially parallel to the occupant spreads and is received by the occupant without suddenly inflating and compressing the occupant moving forward in a forward leaning posture due to an impact. A good expansion / deployment speed and form can be obtained to alleviate the impact.

The occupant-facing base cloth 7c of the inner bag portion 7 is provided with a throttle means 9 for regulating the amount of inflation toward the occupant when the airbag 6 is inflated and deployed. The squeezing means 9 squeezes at least a part of the occupant-facing base cloth 7c in a bellows-like manner. The overlapped close portion is sewn with a sewing strength that cannot be broken by the internal pressure applied to the inner bag portion 7 when the airbag 6 is inflated and deployed.

According to the illustrated example, the squeezing means 9 is provided on the occupant-facing side of the inner bag portion 7 facing the gas inlet 7a formed in the inflator-facing base fabric 7b. Figure 1
3, when the airbag 6 is inflated and deployed, the amount of inflation of the inner bag portion 7 with respect to the occupant-facing side is kept small so that the lower side of the inner bag portion 7 is relatively higher than the upper side. It expands and expands greatly.

When the airbag 6 is folded, the outer bag portion 8 and the substantially central portion of the occupant-facing base cloth 7c of the inner bag portion 7 come into close contact with each other, and the gas inlet 8a of the outer bag portion 8 is closed. It is preferable that the peripheral portion is folded in a state where the inner bag portion 7 has slack on the inflator-facing base fabric 7b side. In the initial stage of the operation of the inflation and deployment of the airbag 6, the inner bag 7 is inflated and deployed in the vertical direction with a long length without almost flowing into the outer bag 8, and the outer bag 8 is extended. The amount of expansion of the occupant-facing base cloth 8c of the bag portion 8 is suppressed to a small value.

FIGS. 4A to 4C schematically show an example of a process of inflating and deploying the airbag 6 of the present invention. FIG.
4A shows an inflated and deployed state of the airbag 6 in an initial stage, FIG. 4B shows an inflated and deployed state of the airbag 6 in an intermediate stage, and FIG.
In the final stage of the expansion.

When the vehicle receives a large impact of a predetermined magnitude or more, the impact is sensed, the inflator 5 is activated, and high-pressure gas is introduced into the inner bag 7 from the gas inlet 7a. The tear line of the airbag grid is ruptured, and the airbag grid opens to start inflating outwardly of the instrument panel.

In the initial stage of the operation of the inflation and deployment of the airbag 6, the high-pressure gas introduced into the inner bag portion 7 is as shown in FIG.
As shown in (a), a large amount flows into the inner bag portion 7, but hardly flows into the outer bag portion 8, and the slack at the base end of the outer bag portion 8 is gradually released. Meanwhile, the inner bag portion 7 spreads over the long upper and lower end portions,
The inner bag 7 is positively inflated in the vertical direction. At this time, since the gas inlets 7a and 8a are hermetically sealed and fixed, high-pressure gas does not flow around the gas inlets 7a and 8a, and the movement in the front-rear direction is suppressed.

Subsequently, as shown in FIG. 4 (b), the inner bag portion 7 protrudes from the gas inlet port 7a in the lengthwise direction by a long length in the vertical direction, and bulges toward the occupant. While regulating the amount, both the bag portions 7 and 8 are positively expanded and deployed in the vertical direction. At this time, the high-pressure gas introduced into the inner bag portion 7 further flows into the inner bag portion 7 in a large amount.
In addition, the outer bag portion 8 restricts the amount of inflation toward the occupant-facing side, and the outer bag portion 8 reduces the amount of swelling of the occupant-facing base fabric 8c while keeping the amount of inflation of the inner bag portion 7 on the occupant-facing side. Actively expands toward a wide area in the vertical direction.

Subsequently, the high-pressure gas introduced toward the inside of the inner bag portion 7 is more positively moved in the vertical direction on the side facing the occupant while restricting the flow direction to the vertical direction of the inner bag portion 7. To expand. When the high-pressure gas in the inner bag 7 reaches a predetermined amount, as shown in FIG. 4C, the inflator-facing base fabric of the inner bag 7 has a certain time difference from the time of gas introduction in the inner bag 7. A large tension acts on both the base cloth 7b and the occupant facing base cloth 7c, and the tension breaks the pair of gas blowing holes 7e of the inner bag part 7, so that the high-pressure gas in the inner bag part 7 is released from the respective base cloth 7b. , 7c flow out of the outer bag portion 8 through the gas outlet holes 7e.

The inflator-facing base fabric 8b and the occupant-facing base fabric 8c of the outer bag 8
Both extend toward a wide part in the left and right and up and down directions, and the amount of expansion toward the occupant who moves forward in a forward leaning posture by the impact is controlled without delaying the pop-out timing, and it is at the height position of the occupant's neck. Does not expand extremely,
The outer bag portion 8 is inflated and deployed in a predetermined form at a height corresponding to the occupant's chest from the abdomen.

The upper body of the occupant is quickly buffered and supported by the airbag 6 to greatly reduce the impact force applied to the human body. At this time, the high pressure gas in the outer bag 8
As shown in FIG. 5, according to the impact force of the human body, it is discharged to the outside from the vent hole 8e of the inflator-facing base fabric 8b and absorbs the impact force applied to the human body.

Next, an airbag 60 according to a second embodiment of the present invention will be described with reference to FIGS. FIG.
FIG. 8 schematically shows an airbag device 10 mounted inside a front seat in front of a rear seat (not shown).
7 schematically shows the inflated and deployed form of the airbag 60 when the inflation is completed, and FIGS. 7 and 8 show the form in which the outer bag portion and the inner bag portion of the airbag 60 are expanded in a plane.
In these drawings, members that are substantially the same as those in the first embodiment are given the same member names and reference numerals. Therefore, a detailed description of these members will be omitted.

In these figures, in the first embodiment, the inner bag portion 7 of the airbag 6 has an elongated shape in the vertical direction, and the length of the inner bag portion in the elongated direction corresponds to that of the outer bag portion 8. What was set longer than the length of the direction,
The inner bag portion 7 of the airbag 60 according to the second embodiment has an elongated shape in the left-right direction, and the length in the elongated direction is set longer than the length in the left-right direction corresponding to the outer bag portion 8. . In addition, even in the second embodiment, each bag portion 7,
8 has the same outer shape as that of the first embodiment.

The inflator-facing base fabric 8b of the outer bag portion 8
On the left and right sides of the gas inlet 8a, circular vent holes 8e, 8e are formed. One of the inner bag portions 7
Are the inflator-facing base cloth 7b and the occupant-facing base cloth 7c.
A pair of left and right slit-shaped gas blowing holes 7e, 7e are formed at the left and right front end portions and at the outer peripheral edges on both the upper and lower sides. As in the first embodiment, the gas outlets 7e are arranged on the same straight line along the left-right direction with an interval that allows the airbag 60 to be torn with a predetermined tension when the airbag 60 is inflated and deployed.

The occupant-facing base cloth 7c of the inner bag portion 7 is provided with a squeezing means 9 as in the first embodiment. At least one central portion of the occupant-facing base fabric 7c closely stacked in a bellows shape is sewn so as not to be broken by an internal pressure applied to the inner bag portion 7 when the airbag 60 is inflated and deployed, and is formed in a point shape. Has been squeezed. The squeezing means 9 is provided on the inflator-facing base cloth 7
b is provided on the occupant-facing side opposite to the gas introduction port 7a formed in the b. I try to expand.

In the initial stage of the inflation and deployment of the airbag 60 according to the second embodiment, the amount of inflation of the outer bag portion 8 toward the occupant-facing surface is controlled similarly to the airbag 6 of the first embodiment. While suppressing the behavior in the front and rear direction, while minimizing the inflation and deployment of the airbag 60 in the front and rear direction,
The inflated and deployed surface of the airbag 60 expands substantially parallel to the occupant. Even when the airbag device 10 is installed inside the front seat in front of the rear seat (not shown), as described above, the lengths and shapes of the inner bag portion 7 and the outer bag portion 8 and the gas outlet holes 7e are provided. By appropriately determining the setting portion of the airbag 60, a wide inflatable surface of the airbag 60 can be obtained over a wide range of the room without suddenly inflating toward an occupant moving forward in a forward leaning posture due to an impact.

The inner bag portion 7 is not limited to the above embodiments, but has, for example, a cross-shaped elongated shape in the vertical and horizontal directions, and the length in the elongated direction is determined by the outer bag portion. 8 may be set to be longer than the length in the vertical and horizontal directions, or a plurality of pairs of elongated shapes may be provided radially, and the lengths in each direction may be set to different lengths. In each of the above-described embodiments, the pair of adjacent gas outlet holes 7e are torn by the predetermined tension when the airbags 6, 60 are deployed at the distal ends of the inflator-facing base cloth 7b and the occupant-facing base cloth 7c. Although they are arranged on the same straight line with a possible interval, a single gas blowing hole having a circular or rectangular shape may be employed.

As is clear from the above description, according to each of the above embodiments, the length of at least one direction of the inner bag 7 is longer than the length of one direction corresponding to the outer bag 8. When the airbags 6, 60 are inflated and deployed, the forward and backward movement toward the occupant is controlled during the inflation and deployment of the airbags 6, 60 to minimize the inflation and deployment of the airbags 6, 60 in the forward and backward directions. However, the inflation and deployment of the airbags 6, 60 in the circumferential direction can be smoothly expanded. In addition,
The present invention is not limited to the above embodiments, but naturally includes a technical range that can be easily changed by those skilled in the art from those embodiments.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing an example of a deployed form of an airbag which is a typical embodiment of the present invention when inflation is completed.

FIG. 2 is a rear view when the outer bag portion of the airbag is expanded in a plane.

FIG. 3 is a rear view when the inner bag portion of the airbag is expanded in a plane.

FIG. 4 is an explanatory view schematically showing an example of an inflation and deployment process of the airbag.

FIG. 5 is an explanatory view schematically showing an example when the airbag cushions and supports an occupant.

FIG. 6 is a schematic view showing an airbag according to a second embodiment of the present invention.

FIG. 7 is a rear view when the outer bag portion of the airbag is expanded in a plane.

FIG. 8 is a rear view when the inner bag portion of the airbag is expanded in a plane.

[Explanation of symbols]

 1,10 Airbag device 2 Stud bolt 3 Retainer main body 3a Inflator storage portion 3b Airbag storage portion 4 Intermediate retainer 5 Inflator 6,60 Airbag 7 Inner bag portion 7a, 8a Gas inlet 7b, 8b Inflator facing base fabric 7c, 8c Occupant facing base cloth 7d, 8d Mounting hole 7e Gas blowing hole 8 Outer bag 8e Vent hole 9 Throttling means

Claims (4)

[Claims] 1. An airbag having a multiple bag structure having an inner bag portion and an outer bag portion having a common gas inlet for introducing gas generated from a gas supply source at a substantially central portion, wherein the inner bag is provided. An airbag, wherein the length of at least one direction of the portion is set to be longer than the length of the corresponding outer bag portion in one direction. 2. A gas outlet for allowing gas introduced from the gas inlet to flow into the outer bag at both ends in the one direction of the inner bag with the gas inlet interposed therebetween. The airbag according to claim 1, wherein 3. The substantially central portions of the outer bag portion and the inner bag portion on the occupant-facing surface side are in close contact with each other, and the peripheral portion of the gas inlet of the outer bag portion is slackened to the rear side of the inner bag portion. 2. The airbag according to claim 1, wherein the airbag is folded in a folded state. 4. The inner bag portion has an elongated shape, wherein the one direction is the elongated direction, and the length of the elongated direction is set to be longer than the length of the outer bag portion in the corresponding direction. The airbag according to claim 1, wherein at least one portion of a substantially central portion of the inner bag portion on the occupant facing surface side is narrowed in a point shape.