JP2002193058A - Air bag - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve an expansion characteristic of an air bag, by effectively utilizing gas, and facilitate folding of the air bag. SOLUTION: A third ground fabric 23 smaller than a first/second ground fabric 21, 22 is arranged between the first/second ground fabrics 21, 22 constituting an outer shell. The third ground fabric 23 covers a gas introducing port 28 formed in the first ground fabric 21, to be sewn to the first ground fabric 21 by a circular annular connection part 33 in four parts. An exhaust port 35 opened to outside an air bag 1 is formed in a part surrounded by the connection part 33 in one part. The vicinity of the exhaust port 35 and the second ground fabric 22 are connected by a hanging cord main unit part 42 of a hanging cord 41. A circular block part 49 is mounted in the hanging cord main unit part 42. The block part 49 covers the exhaust port 35 in a condition hooked thereto in a condition folding the air bag 1, a leak of gas in the beginning of expansion is suppressed, and the gas can be effectively utilized.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an airbag provided on a steering wheel of a vehicle, for example.

[0002]

2. Description of the Related Art Conventionally, for example, an airbag device for a driver's seat provided in a boss portion of a steering wheel of an automobile and inflating a bag-like airbag by inflow of gas to reduce the impact of a collision applied to an occupant. Is used. The airbag used in the airbag device is 2
The outer circumferences of a plurality of circular nylon woven fabrics are sewn together to form a flat bag. Further, in this airbag, a gas introduction hole is formed in a base cloth on the vehicle body side, gas is introduced from the gas introduction hole, and the periphery of the gas introduction hole is fixed to the steering wheel body, and the airbag is folded small. It is stored. When the inflator is operated, the swelling is inflated toward the occupant by the pressure of the gas injected from the inflator, and the occupant thrown forward is received and restrained to reduce the impact.

[0003] Such an airbag is, for example, in a state where an occupant takes an extreme forward leaning posture such that an upper body approaches a steering wheel (Out of position,
When it is assumed that the airbag device is activated when seated in OOP), it is required to relax the pressure applied to the object to be protected and to deploy it flatly and widely.
As described in JP-A-7-149199, a configuration is known in which a cloth is provided inside a bag to control the gas flow toward the outer periphery. That is, in this configuration, on the anti-occupant side, that is, inside the outer shell formed by the base cloth on the vehicle body side and the inflator side and the base cloth on the occupant side,
A circular inner cloth is arranged to cover the gas introduction holes, and sewn to a base cloth on the vehicle body side at a plurality of locations along the outer peripheral portion of the inner cloth,
Gas flows into the airbag from between the sewn portions. Further, in this configuration, the vent hole, which is a through hole for exhausting the gas in the airbag, is formed in the base cloth on the vehicle body side, located on the outer peripheral side of the inner cloth.

However, Japanese Patent Application Laid-Open No.
In the configuration described in Japanese Patent Application Laid-Open No. 9-209, the position of the vent hole is limited because the inner cloth is provided. In order to increase the capacity of the inflator and reduce the deployment speed, the vent hole is disposed on the outer peripheral side of the inner cloth at a position away from the mounting portion serving as a support point. In the configuration in which the vent hole is arranged on the outer peripheral side of the inner cloth as described above, the vent hole overlaps with the annular rim portion (grip portion) in the process of deploying the airbag device mounted on the boss portion of the steering wheel, Alternatively, it is located on the outer peripheral side of the rim portion. When the vent hole is located on the outer peripheral side in this manner, the influence of the gas exhausted from the vent hole on the occupant is considered, and the cooling means for the gas supplied from the inflator or the inflator for generating a relatively low-temperature gas Therefore, it is necessary to consider the use of such a material, which makes it difficult to reduce the manufacturing cost. In the configuration in which the vent hole is located on the outer peripheral side, when the airbag is deployed, the airbag is folded so that the vent hole surely faces the opposite side of the occupant so that the occupant can be buffered and a predetermined pressure regulating action can be secured. You need to consider the method. In this regard, since the airbag is soft, it is difficult to stabilize the position of the vent hole provided on the outer peripheral portion away from the mounting portion serving as the support point.

[0005] Further, the inner cloth does not have the effect of changing the gas flow unless the inner cloth has a predetermined size or more. However, the inner cloth is sewn to the base cloth on the side opposite to the occupant, and the inflow of gas is prevented. Since the central portion sometimes swells to the occupant side, if the size exceeds a predetermined size, the central portion swells greatly to the occupant side, causing a problem of pressure on the occupant.

Further, for example, Japanese Patent Application Laid-Open No. H10-152009
There is known an airbag described in Japanese Patent Application Laid-Open Publication No. HEI 9-86,980. In the configuration described in this publication, the inner cloth forms a compartment into which the inflator blows gas directly, and a compartment which is connected to the compartment and forms a main part of the airbag internal space. It regulates the deployment dimensions of the airbag to the occupant side.

However, Japanese Patent Application Laid-Open No. H10-1520 discloses
In the configuration described in Japanese Patent Application Laid-Open No. 09-0909, the vent hole for exhausting the gas in the airbag is not shown or mentioned, and has the same problem as the configuration described in Japanese Patent Application Laid-Open No. 7-149199.

[0008]

As described above, there is a need for a structure that can efficiently use gas and can easily improve the deployment characteristics.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object to provide an airbag which can efficiently utilize gas and can easily improve deployment characteristics.

[0010]

According to the first aspect of the present invention, there is provided an airbag in which gas flows in from a folded storage state and is deployed, and an attachment portion attached to a support member and the gas are introduced. A first base cloth provided with a gas introduction portion, and a second base layer which is overlaid on the protected object side of the first base cloth and whose outer peripheral portion is joined to form the outer shell of the bag together with the first base cloth. And an exhaust port provided on the first base fabric, the exhaust port communicating the inside of the bag body to the side of the object to be protected, and the exhaust port connected to the second base fabric. A suspending string main body for regulating a movement dimension to the protected object side and a suspending string provided with a closing section capable of closing the exhaust port, and in the retracted state, the closing section of the suspending string includes the exhaust It is held so as to cover the mouth and to be detachable.

In this configuration, when the gas is introduced from the gas introduction portion, the gas is expanded and deployed from the stored state folded by the gas, and is further exhausted from the exhaust port to the side opposite to the protection object. And the movement dimension of the second base cloth to the protected object side is regulated by the hanging string connected to the second base cloth,
The inflation height of the airbag is regulated, and a suitable deployed shape can be easily and stably obtained. Furthermore, since the exhaust port is covered with the closing portion of the hanging string in the initial stage of deployment, the gas is effectively used, and in a state where the hanging string is stretched thereafter, the closing portion separates from the exhaust port. Sufficient exhaust is possible, and good deployment characteristics are easily obtained. Furthermore, since the closing part of the hanging string covers and positions the exhaust port in the housed state, the folding operation of the airbag is facilitated, and the manufacturing cost is reduced.

According to a second aspect of the present invention, there is provided the airbag according to the first aspect, wherein the hanging string is formed of the first base cloth and the second base cloth.
Are connected to each other.

In this configuration, the configuration is simplified, and the manufacturing cost is reduced.

According to a third aspect of the present invention, in the airbag according to the first aspect, the airbag is disposed between the first and second base fabrics, and is disposed so as to cover a protected object side of the gas introducing portion. A third base cloth joined to the first base cloth by the first and third base cloths, a flow passage located between the first and third base cloths and communicating from the gas introduction section side to the outer peripheral side; Surrounded by
An exhaust port communicating from the protected object side of the third base cloth to the non-protected object side of the first base cloth, and the hanging string is at least one of the first and third base cloths. And the second base cloth, and restricts a movement dimension of the second base cloth to the protected object side.

In this configuration, when the gas is introduced from the gas introduction portion, the gas is guided to the third base cloth, supplied to the outer peripheral side of the airbag through the flow passage, and developed flat. As a result, the pressure applied to the object to be protected is suppressed, the deployment characteristics are improved, and, for example, the pressure on the object to be protected very close to the airbag is easily alleviated.
Also, in the initial stage of deployment, the outer peripheral portion of the airbag is inflated by the gas of the third base cloth to obtain a flat intermediate shape without the action of the hanging string, and no tension is applied to the hanging string, The vent is easily closed and after this intermediate shape,
Good deployment characteristics can be easily obtained by restricting the amount of protrusion by generating tension in the hanging string.

According to a fourth aspect of the present invention, in the airbag according to any one of the first to third aspects, the closing portion of the hanging string is formed integrally with the hanging string body, and a part of the hanging string body. Is drawn out of the bag body from the exhaust port, and is positioned and releasably held by covering the exhaust port.

In this configuration, the number of parts does not increase, the configuration of the suspension string is simplified, and the manufacturing cost is reduced.

According to a fifth aspect of the present invention, there is provided the airbag according to any one of the first to third aspects, wherein the closed portion of the hanging string is provided at the edge of the exhaust port from the outside of the bag body in the folded storage state. The air outlet is brought into contact with and covers the air outlet, and is drawn into the bag body through the air outlet at the time of deployment.

In this configuration, when the airbag is folded and stored, the edge of the exhaust port is sandwiched between the closing section and the hanging string main body so that the closing section covers the exhaust port. In the state where the gas is used effectively and the hanging string is stretched and stretched thereafter, the closing portion is pulled by the hanging string main body and detaches from the exhaust port to the inside of the bag body. As a result, sufficient exhaust is possible, and good deployment characteristics can be easily obtained.

According to a sixth aspect of the present invention, in the airbag according to any one of the first to fifth aspects, the closing portion of the suspension string has a dimension substantially covering the exhaust port.

In this configuration, the suspending string suppresses the discharge of gas from the air outlet to the outside of the airbag in the process of deploying the airbag, and the gas for inflation is effectively used for inflation of the airbag. Deployment characteristics are obtained. Further, the pressure regulation of the exhaust port can be realized without requiring a complicated control device, and the manufacturing cost is reduced.

[0022]

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

1 to 4, reference numeral 1 denotes an airbag, and this airbag 1 constitutes an airbag device 2 partially shown in FIGS. The airbag device 2 is mounted on a steering wheel main body 4 as a member to be mounted on a steering wheel 3 of an automobile as a vehicle shown in FIG. 2 and impacts an occupant A shown in FIG. It is designed to protect from. In addition,
The steering wheel body 4 is usually attached to an inclined steering shaft and used in an inclined state. Hereinafter, the protected object side to which the airbag device 2 is attached is referred to as an occupant side, an upper side, or a front side. ,
The opposite side of the non-protected object side, that is, the occupant side,
Alternatively, the front side is referred to as the rear side, the front upper side of the vehicle, that is, the windshield side is referred to as the front side, the rear lower side is referred to as the rear side, and the side facing the occupant is described as horizontal in the drawing.

The steering wheel body 4 is
An annular rim portion 5 as a grip portion also called a grip portion or a ring portion, a boss portion 6 located inside the rim portion 5, and a plurality of limbs connecting the rim portion 5 and the boss portion 6, for example, It has three or four spokes 7, and a steering shaft (not shown) is fitted and fixed to a boss 6 a provided on the boss 6.

The airbag device 2 includes a base plate 11 constituting a support member, an airbag 1, an inflator 12, and a retainer attached to the base plate 11.
14, a cover body 15, and the like.

The base plate 11 is formed by press-molding a metal plate. The base plate 11 has a substantially rectangular planar shape and a peripheral plate bent downward from the outer periphery of the base plate. Is formed. A circular hole-shaped inflator mounting hole is formed in the substrate portion at a substantially central portion, and a plurality of, for example, four bolt mounting holes are located around the inflator mounting hole. Is formed. A mounting piece is formed on the peripheral plate, and the mounting piece is mounted on a core metal of the boss 6 of the steering wheel body 4.

As shown in FIG. 2 and the like, the inflator 12 includes a substantially cylindrical main body 12a.
A flange portion 12b protrudes from the outer peripheral portion of 2a, and a plurality of gas injection ports 12c for injecting gas are radially arranged on the upper side of the flange portion 12b toward the outer peripheral side. Further, a bolt mounting hole communicating with the bolt mounting hole of the base plate 11 is formed in the flange portion 12b.

The retainer 14 has a retainer body having an annular shape or the like, and mounting bolts inserted into the bolt mounting holes are integrally fixed to the retainer body downward.

The cover body 15 is integrally formed of a synthetic resin, and has a curved covering portion 15a that covers a part of the boss portion 6 and the spoke portion 7 of the steering wheel body 4.
It has a rectangular tubular mounting wall portion 15b protruding downward from the lower surface of the covering portion 15a. A portion surrounded by the lower side of the covering portion 15a and the inside of the mounting wall portion 15b is a storage space for the airbag 1. Also, the mounting wall 15b
Is fitted and engaged with the outer peripheral portion of the peripheral plate portion of the base plate 11, and is fixed by tightening a belt or using a plurality of rivets. Furthermore, the flat surface substantially H
A fragile tear line is formed in the shape of a letter and the like, and when the airbag 1 is deployed, the tear line is broken to form a door portion 20 that opens by rotating.

As shown in FIGS. 1 to 4, the airbag 1 has a first base cloth on the vehicle body side, each of which has a circular shape.
21 and a second base cloth 22 facing the occupant side;
And a third base fabric 23 having a small circular shape and arranged in the outer shell constituted by the first and second bases 22. And these fabrics
Reference numerals 21, 22, and 23 are also called plates (lower plate portion, upper plate portion, middle plate portion) or panels (back panel, front panel, center panel), and are made of, for example, nylon woven cloth. In the embodiment, a woven fabric of 66 nylon fibers and a yarn of 350 dtex are used, and the number of drivings is 24.4 per cm (length and width (longitudinal direction / weft direction)).
(2 pieces / inch), a so-called non-coat type base cloth not covered with a resin or the like is used.

Then, the first base cloth 21 and the second base cloth 22 are integrally sewn along the outer peripheral sewn portion 24a of the double chain stitch in an overlapped state. A flat bag-like outer shell is formed by the first base cloth 21 and the second base cloth 22 in a state where the inner and outer sides are inverted and the ears serving as the sewing allowance face inward. In the present embodiment, the outer peripheral sewing portion 24a
The sewing thread used is a nylon 66 thread and the upper thread is 1
395 dtex (1260 denier), lower thread is 930 dtex
(840 deniers), and the number of hand movements is 3.5 needles / cm.

The first base cloth 21, which is located on the lower side and fixed to the base plate 11, has an inflator insertion opening serving as a gas introduction part which is located at the center and into which the main body 12a of the inflator 12 is inserted. Is formed around the gas inlet 28, and is formed around the gas inlet 28,
A circular bolt mounting hole 29 which is a bag fixing hole into which the mounting bolt of the retainer 14 is inserted is formed, and an annular mounting portion 30 including these bolt mounting holes 29 and surrounding the gas inlet 28 is formed.
Is configured.

The third base cloth 23 can be called a gas regulating panel, and includes a circular panel part 23a having a smaller diameter than the first and second base cloths 21 and 22. Two
3a has, for example, a radius slightly larger than １ ／ of the radius of the first and second base cloths 21 and 22 and is concentric with the first and second base cloths 21 and 22; The gas inlet 28 and the peripheral portion of the gas inlet 28 are arranged so as to cover the gas inlet 28. Further, the third base cloth 23 is sewn to the first base cloth 21 only at the joining portion 33 at a plurality of places near the outer peripheral portion of the third base cloth 23, in this embodiment at four places. Are joined.
In the present embodiment, the joints 33 are substantially airtightly formed by circular double stitching lines (stitches), and are arranged at substantially equal intervals in a so-called radial manner so as to surround the gas inlet 28. ing. The sewing conditions of the joining portion 33 are the same as the sewing conditions of the above-described outer peripheral sewing portion 24a in regard to the number of threads and the number of needle movements, in addition to using the main sewing.

The space between the outer periphery of the third base cloth 23 and the first base cloth 21, which is a part between the joints 33, is
Flow passage 34 through which gas introduced from gas inlet 28 can pass
The space between the first base cloth 21 and the third base cloth 23 on the upstream side of the flow path 34 becomes a first compartment B1.
The second branch B2 is located between the first and third base cloths 21 and 23 and the second base cloth 22 on the downstream side of the first base cloth 21.

Further, one of the plurality of joints 33
In the present embodiment, the exhaust port (vent hole) 35 serving as an exhaust portion is opened at one or a plurality of locations, which is concentrically located within the joint portion 33 at one front side in the present embodiment. Is formed. That is, the exhaust port 35 does not communicate between the inside and outside of the airbag 1 on the lower surface of the third base cloth 23, that is, the first compartment B1, and the occupant side on the upper surface of the third base cloth 23, that is, the second compartment B2. And the lower surface outside the airbag 1, that is, the side opposite to the occupant.

The airbag 1 is provided with a plurality of or singly, in this embodiment, two connecting means, also referred to as a tether belt, and a suspending string 41, which is also referred to as a tether belt.
The third base cloth 23 and the second base cloth 22 are connected by 41. The hanging string 41 includes a belt-shaped or belt-shaped hanging string main body 42 having a predetermined width, and the hanging string main body 42 is formed from a plurality of places, for example, two places of the third base cloth 23, Lower hanging strap main body integrally extended in the direction
43 and an upper suspending string main body 47 integrally extending in the diametrical direction from a plurality of, for example, two places of a patch section 46 as an attachment portion of the upper suspending string main body member 45. One of the lower hanging string main bodies 43 is disposed close to the exhaust port 35, and is provided on the outer peripheral side of the exhaust port 35 in the present embodiment. That is, the suspension string 41 is formed with a position corresponding to the position immediately adjacent to the joint 33 as a root. The upper hanging string main body member 45 is made of, for example, the same material as the other base cloth, and the patch portion 46 has a planar circular shape.
The base cloth 22 is sewn to a circular center portion. Further, the lower hanging string main body 43 and the upper hanging string main body 47 are joined by overlapping and sewn the terminals at the distal ends.

Further, the suspension string 41 arranged on the side where the exhaust port 35 is formed has a closed part 49 which is a circular lid and is located at a predetermined position of the lower suspension string main part 43 of the suspension string main part 42. Is provided. The closing portion 49 is made of, for example, a deformable woven fabric, a synthetic resin, rubber, or the like. In the present embodiment, the closing portion 49 is made of the same material as the other base fabric, that is, a woven fabric of nylon 66 fiber in a disk shape. The portion excluding the vicinity of the outer edge portion, that is, the vicinity of the center portion, is attached to the lower hanging string main body 43 by the fixing portion 50 which is a suture line. Further, in the present embodiment, the closing portion 49 is smaller than the diameter of the opening of the exhaust port 35.
Is slightly larger than the diameter of the opening of the exhaust port 35, and the width of the hanging string main body 47 is formed slightly smaller.

When assembling the airbag device 2, the retainer 14 is inserted inside the airbag 1 and mounting bolts are inserted into the bolt mounting holes 29 of the airbag 1 and the base plate 11. Then, the airbag 1 is folded into a predetermined shape such as a petal shape, and the airbag 1 is fitted over the cover body 15 from above. Further, the upper part of the inflator 12 is inserted into the airbag 1 from below through the inflator mounting hole of the base plate 11 and the gas inlet 28 of the airbag 1, and the mounting bolt is inserted into the bolt mounting hole of the flange 12b. And tighten it with a nut from below. In this state, the first base cloth 21 of the airbag 1 and the base plate 11 are fastened together between the retainer 14 and the inflator 12, that is, these members 12, 14, 21, 11 are collectively fixed by a nut. Then, the airbag device 2 is assembled.

In the airbag device 2, the mounting piece provided on the base plate 11 is fixed to the core of the boss 6 of the steering wheel body 4 using bolts or the like.
Mounted on the steering wheel 3.

When a collision impact is applied to the automobile equipped with the airbag device 2, the inflator 12 is activated by a control unit (not shown), and the gas is rapidly injected into the airbag 1 from the gas injection port 12c of the inflator 12. Is injected. Then, the airbag 1 breaks the cover body 15 along the tear line, rotates the door part 20 to form a projecting port, bulges through the projecting port, and forms a predetermined shape in front of the occupant A. The occupant A that bulges out and is thrown forward is received and restrained, and the impact applied to the occupant A is reduced.

Next, the folded state of the airbag 1 and the operation when the airbag 1 is inflated will be described in detail.

First, when the airbag 1 is folded, first, the first and second base fabrics 2 are folded so that the whole becomes flat.
1 and 22, and the panel portion 23a of the third base fabric 23 are overlapped. At this time, as shown in FIG. As shown in FIG. 4 (b), the closing portion 49 is deformed together with the hanging string main body 42 of the hanging string 41 from the exhaust port 35 and pulled out of the bag body while deforming the closing portion 49. Subsequently, as shown in FIG. 4 (c), The hanging string main body 42 is returned to the inside of the bag. At this time, the closing portion 49 having a larger diameter than the exhaust port 35 comes into contact with the edge of the exhaust port 35, and is hooked on the exhaust port 35 so as to cover the exhaust port 35 and is positioned and held. Next, as shown in FIG.
2 is lifted to adjust the position of the suspending string main body 42 of the suspending string 41, and as shown in FIG. In the folding preparation procedure, the exhaust port 35 is closed by the closing portion 49, but the outside air is supplied and exhausted from the gas inlet port 28, so that there is no problem in the operation.

The airbag 1 is pressed from the outer peripheral portion to the central portion to accumulate in a wavy manner while maintaining the state in which the closing portion 49 of the hanging string 41 covers the exhaust port 35 as described above. 1 is rotated so as to be wrapped around the area where the sheets are accumulated, so that the cover body 15 can be housed.

Next, the deployment process of the airbag 1 will be described with reference to FIG. In FIG. 1, white arrows schematically indicate gas flows. Arrow C indicates a vertical direction, and arrow D indicates a horizontal direction orthogonal to the vertical direction.

FIG. 1A shows a state immediately after the airbag 1 breaks a tear line, which is a predetermined weak portion of the cover body 15, and opens the door 20. First, the gas injected from the inflator 12 is supplied to the third base cloth 23 in the airbag 1 by the third base cloth 23.
The lower side of the third base fabric 23 is introduced in the radial direction. At this time, the third base cloth 23 is connected to the first base cloth 21 by a plurality of joints 33 arranged around the gas inlet 28,
Since the first base cloth 21 is fixed to the base plate 11, the third base cloth 23 is held in a state of slightly swelling toward the occupant, that is, the third base cloth 23 is held at a low height. The gas is guided to the outer peripheral portion of the airbag 1 and expands flat in the horizontal direction. In this state, no tension acts on the suspension string 41 at all, and the state in which the closing portion 49 closes the exhaust port 35 is maintained.

FIG. 1 (b) shows a state in which the gas is further developed, and the gas is three-dimensionally inverted near the peripheral portion 24, and the outer peripheral portion of the airbag 1 is inflated upward, but the central portion is inflated. Height hardly changes. Until this state, no tension is applied to the hanging string 41, and the position is relatively fixed without shifting the position with the closing portion 49 closing the exhaust port 35,
Loss of gas from the exhaust port 35 is substantially prevented, and gas pressure is used efficiently.

Next, as shown in FIG. 1 (c) and FIG. 2, further development proceeds, and a so-called full development state is obtained. The gas that causes the airbag 1 to inflate, in particular, the second base cloth 22 from the outer peripheral portion is further introduced into the central portion of the second compartment B2 to inflate the entire airbag 1 into a predetermined shape. In this state,
The suspension string 41 is expanded by tension, and the closing section 49 is drawn into the inside of the air bag 1 from the exhaust port 35 while being deformed while the exhaust port 35 is fully opened.
Acts to regulate the height of the central portion of the airbag 1. In this way, the protrusion height of the airbag 1 with respect to the occupant A to be protected can be set to a predetermined dimension,
Excess or insufficient height dimensions can be prevented. In addition, this hanging string
The protrusion dimension regulated by 41 can be set, for example, in consideration of the provisions of FMVSS208, which is a vehicle collision safety standard in the United States.

Further, as shown in FIG. 1 (d), the occupant A is received by the second base cloth 22 of the airbag 1, and when the occupant A is fully opened, gas flows through the exhaust port 35 communicating with the non-occupant side. Emitted and absorbs shock.

As described above, the airbag 1 of the present embodiment
According to the above, when the airbag 1 is inflated and deployed, immediately after the start of the deployment, the air outlet 35 opening outside the airbag 1 is connected to the hanging string 41
The gas for inflation can be prevented from being exhausted to the outside of the bag body by covering with the closing portion 49, so that the gas can be efficiently used without waste. Therefore, the inflator 12 having a minimum capacity for inflating the airbag 1 can be applied. Therefore, the inflator 12 can be reduced in weight and size, and the amount of unused processed and discarded chemicals in the processing of many used vehicles can be suppressed to a minimum. Good compatibility with

The closing portion 49 of the hanging string 41 is detachably attached to the first base cloth 21 so as to cover the exhaust port 35 from outside before deployment, so to speak, in the latter half of deployment of the airbag 1. The tension is applied to the hanging string main body 42 of the hanging string 41, and the closing portion 49 is detached from the exhaust port 35 and is drawn inward, so that the exhaust port 35 can be automatically fully opened. For this reason, when the airbag 1 restrains the occupant, the exhaust port 35 has a predetermined opening area, so that it is possible to preferably absorb shock of the occupant.

Further, a series of operations which function as a valve for opening and closing the exhaust port 35 does not require control from the outside of the airbag 1, and the entire airbag apparatus 2 is more expensive than the conventional configuration. There is no need to add any elements, and the increase in cost and the size of the airbag device 2 can be substantially reduced to such a degree that it is not necessary to consider it. Further, the manufacture is easy, and there is no need to consider failure or the like.

According to the present embodiment, the first and second base cloths 21 and 22 forming the outer shell are provided inside the first and second base cloths 21 and 22.
A so-called 2.5-layer type airbag 1 in which a third base fabric 23 smaller than 22 is arranged to partition a first compartment B1 and a second compartment B2, and an exhaust port 35 is provided on the downstream side of the second Branch B2
Only the third base fabric 23 allows the airbag 1 to have initial deployment directivity in the direction intersecting the occupant A, which is the direction of the object to be protected. At this time, the first
The gas flowing along the base cloth 21 is blown out toward the periphery of the airbag 1, and the exhaust port 35 is closed by the closing portion 49, so that the gas is covered by the closing portion 49 of the hanging string 41. There is no need to consider the gas lost from the exhaust port 35, and there is no need to compensate for the lost gas and use an inflator with a sufficient capacity, so that the manufacturing cost and size of the airbag device 2 can be suppressed.

Further, during the deployment process, gas is not discharged from the first compartment B1 that is not directly connected to the outside of the airbag 1 to the outside of the airbag 1, and the second compartment B1 does not.
Since the exhaust port 35 is covered by the closing portion 49 of the hanging string 41 in the first half of the deployment, the gas introduced from the first compartment B1 to the second compartment B2 in the deployment process The airbag 1 acts without waste so as to substantially inflate the entire airbag 1. Thereafter, the shock applied to the occupant A due to the contact of the occupant A is absorbed and reduced, and the hanging string 41 is separated and opened. Gas is released from the second compartment B2 to the outside of the airbag 1 through the exhaust port 35, and the passenger A can be restrained so as to appropriately reduce the impact it receives.

In a so-called 2.5-layer type airbag, the third base cloth 23 and the hanging string
With the hanging string main body portion 41, a desired deployment characteristic, that is, a deployment operation of rapidly deploying the airbag 1 to the outer peripheral side and thereafter inflating the central portion can be easily realized.
Thus, for example, the pressure on the occupant A very close to the steering wheel 3, that is, the airbag 1, can be easily reduced, which is effective as a so-called OOP measure.

Further, since at least a part of the suspension string 41 is formed integrally with the third base cloth 23, the number of parts can be reduced and the cost can be reduced.

In the above embodiment, the suspension string 41 is formed by attaching the separate closure 49 having a width dimension substantially covering the exhaust port 35 to the suspension string main body 42. Can be formed integrally with the hanging string main body 42, the number of components can be reduced, and the manufacturing cost can be reduced.

For example, as shown in FIG. 5, a part of the hanging string main body 42 may be drawn out of the bag body from the exhaust port 35 to form the closing portion 55. Also in this configuration, in the first half of the deployment of the airbag 1, the ventilation resistance of the exhaust port 35 is increased to suppress the discharge of gas, and in the second half of the deployment, the exhaust port is completely drawn into the bag body of the airbag 1 and
With the 35 fully opened, the height of the airbag 1 can be regulated as the hanging string 41.

Further, in the configuration shown in FIG. 5, the opposing reversing portions 56, 56 constituting the closing portion 55 can be formed by simply turning over. Stitches, which are sewing threads that can be broken by action, can also be connected.

Further, regardless of whether or not the closure portion is formed as a separate body, one or more locations near the exhaust portion may be connected to the first base cloth 21 or the third base cloth in the vicinity of the exhaust port. Base cloth 23
By providing a locking means for removably locking the lower member of the airbag 1 such as when the tension is not applied to the suspension string 41, the opening area of the exhaust port 35 can be reliably reduced, and When the suspension string 41 is under tension, the exhaust port 35 can be easily released and fully opened. Further, regarding various folding processes of the airbag 1, the exhaust port 35 and the hanging string are provided.
Since the relative positional relationship between the airbag 1 and the closing portion 41 can be maintained, the exhaust from the exhaust port 35 in the initial state in the deployment of the airbag 1 is suppressed, and the gas generated by the inflator 12 is efficiently used. it can.

As the locking means, for example, as shown in FIG. 6, an insertion side member 62 of a snap 61 called a hook or the like is attached to the hanging string 41 by sewing or the like. Receiving member 63 engaged with
Can be attached to the third base cloth 23 by sewing or the like. The snap 61 may be provided at one location near the peripheral edge of the exhaust port 35, or may be provided at a plurality of locations, such as at two or more locations diametrically opposed to the exhaust port 35. .

As the locking means, in addition to the snap 61, a stitch made of breakable sewing thread, a planar fastener,
An adhesive such as Arabic glue can be used.

In the above embodiment, the third
A so-called 2.5-layer airbag 1 whose base cloth 23 is smaller than the first and second base cloths 21 and 22 is used, but a plurality of third base cloths are provided inside the base cloth constituting the outer shell. The outer diameter of the base cloth arranged inside the base cloth constituting the outer shell, that is, the diameter dimension is the same as that of the base cloth forming the outer shell, and the outer peripheral portion is sewn at a time. You can also wear it. And
As described above, in the configuration in which the base cloth is further arranged in the base cloth constituting the outer shell, the airbag 1 has a tendency to flatten out in the initial stage of the expansion process, and therefore, the gas is discharged from the lower exhaust port. While blow-through tends to occur, the timing at which tension acts on the suspending string tends to be late, so that the effect of the configuration of the present invention in which the exhaust port can be opened during the deployment process is remarkable.

Further, the present invention can be applied to an airbag which does not have the third base cloth but is formed only of the base cloth forming the outer shell. And like this,
Even when applied to an airbag composed of only the base fabric constituting the outer shell, the exhaust port can be reliably closed at the beginning of the deployment process, and at the time when tension is applied to the hanging string. Since the exhaust port can be reliably opened, the gas of the present invention can be effectively used for inflating the airbag.

In the above embodiment, the joints 33 are provided at four places, and the exhaust port is provided at one of the joints 33.
The exhaust port 35 is opened and closed by the hanging string 41.
, The number of exhaust ports 35, and the number of suspension strings 41 can be changed as appropriate. When a plurality of exhaust ports are provided, not all of the exhaust ports are necessarily opened and closed by the hanging string 41, and even if some of the exhaust ports 35 are normally open, a certain effect can be obtained with respect to the effective use of gas.

Further, the suspending string 41 is partially formed integrally with the third base cloth 23, entirely formed integrally with the third base cloth 23, or formed with the third base cloth 23. It can also be configured separately.

The airbag device is used not only for a driver attached to the steering wheel body, but also for an occupant in a passenger seat provided on an instrument panel, for protecting a side portion provided on a side portion of a seat, or for a rear portion of a seat. The present invention can be widely applied to an airbag of an airbag device for a rear seat provided in a vehicle, and further to an airbag of an airbag device that absorbs an impact of an object to be protected.

[0067]

According to the airbag of the first aspect, when gas is introduced from the gas introducing portion, the gas is inflated and deployed from the storage state folded by the gas, and further, from the exhaust port to the side opposite to the protection object. Exhausted. And, by the hanging string connected to the second base cloth, the movement dimension of the second base cloth to the protected object side is regulated, the inflation height of the airbag is regulated, and a suitable deployed shape is easily and easily obtained. Can be realized stably. Furthermore, since the exhaust port is covered with the closed portion of the hanging string in the initial stage of deployment, the gas can be effectively used. Exhaust can be easily performed, and good deployment characteristics can be easily realized. Furthermore, the closed portion of the hanging string can be positioned and held while covering the exhaust port in the stored state, so that the folding operation of the airbag can be facilitated and the manufacturing cost can be reduced.

According to the airbag of the second aspect, in addition to the effect of the first aspect, the structure of the hanging string is simplified because the first base cloth and the second base cloth are connected to each other. Cost can be reduced.

According to the airbag of the third aspect, in addition to the effect of the first aspect, when a gas is introduced from the gas introduction portion, the gas is guided to the third base cloth and flows through the flow passage. The airbag is supplied to the outer peripheral side of the airbag, and the pressure applied to the object to be protected by being flattened is suppressed, so that the deployment characteristics can be improved.For example, the pressure of the object to be protected very close to the airbag can be reduced. Relaxation is easy. Also, in the initial stage of deployment, the outer peripheral portion of the airbag is inflated by the gas of the third base cloth to obtain a flat intermediate shape without the action of the hanging string, and no tension is applied to the hanging string, The exhaust port can be easily kept in a closed state, and after this intermediate shape, a good deployment characteristic can be easily realized by restricting the amount of protrusion by generating tension in the hanging string.

According to the airbag of the fourth aspect, in addition to the effect of any one of the first to third aspects, the closing portion of the hanging string is formed integrally with the hanging string main body, and With a part pulled out of the bag from the exhaust port,
Since the air outlet is covered and positioned so as to be detachable, the number of components does not increase, the structure of the hanging string can be simplified, and the manufacturing cost can be reduced.

According to the airbag of the fifth aspect, in addition to the effects of any one of the first to third aspects, in addition to the effects of the first to third aspects, the closed portion of the hanging string is provided with a bag body at the edge of the exhaust port in the folded storage state. The exhaust port is contacted from the outside to cover the exhaust port, and when the airbag is folded, the exhaust port is drawn into the bag through the exhaust port. In such a state that the closing portion covers the exhaust port, the closed portion can be positioned and held so that the gas can be effectively used. It is pulled by the cord main body and detaches from the exhaust port to the inside of the bag body to allow sufficient exhaustion, so that good deployment characteristics can be easily realized.

According to the airbag of the sixth aspect, in addition to the effect of any one of the first to fifth aspects, since the closing portion of the hanging string has a size that substantially covers the exhaust port, the hanging string is air-tight. In the process of deploying the bag, it is possible to suppress the discharge of gas from the exhaust port to the outside of the airbag, effectively use the inflation gas for inflation of the airbag, achieve suitable deployment characteristics, and require a complicated control device. The pressure regulation of the exhaust port can be realized, and the manufacturing cost can be reduced.

[Brief description of the drawings]

FIG. 1 is an explanatory view of a deployment operation showing an embodiment of an airbag device including an airbag of the present invention.

FIG. 2 is a cross-sectional view showing a deployed state of the steering wheel provided with the airbag.

FIG. 3 is a perspective view showing a part of the airbag.

FIG. 4 is an explanatory view showing a procedure for preparing a folding of the airbag.

FIG. 5 is a partial perspective view showing another embodiment of the airbag of the present invention.

FIG. 6 is a partial perspective view showing still another embodiment of the airbag of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Airbag 11 Base plate which constitutes a support member 21 First base cloth 22 Second base cloth 23 Third base cloth 28 Gas introduction port as gas introduction section 30 Mounting section 33 Joining section 34 Flow passage 35 Exhaust port 41 Suspension string 42 Suspension string main body 49 Closure A A passenger as a protected object

 ────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yukihiro Naito 218 Aoshima-cho, Fuji-shi, Shizuoka Japan F-term (reference) 3D054 AA02 AA13 CC06 CC11 CC14 DD11 FF13 FF14 FF17

Claims (6)

[Claims] An airbag in which gas flows in from a folded storage state and deploys, wherein a first base cloth provided with an attachment portion attached to a support member and a gas introduction portion into which the gas is introduced, The second base fabric is overlapped with the outer periphery of the first base fabric and joined to the protection object side to form an outer shell of the bag together with the first base fabric.
A base cloth provided on the first base cloth, an exhaust port communicating the inside of the bag body to the side to be protected, and an exhaust port connected to the second base cloth; The apparatus further comprises: a hanging string main body that regulates a movement dimension to the protected object side; and a hanging string provided with a closing part that can close the exhaust port. An airbag, wherein the airbag is positioned and held so as to be detachable while covering the mouth. 2. The airbag according to claim 1, wherein the suspension string connects the first base cloth and the second base cloth. 3. A third base cloth disposed between the first and second base cloths, disposed so as to cover a protected object side of the gas introduction section, and joined to the first base cloth by a joining section. A flow passage that is located between the first and third base fabrics and communicates from the gas introduction unit side to the outer peripheral side; and that is surrounded by the joint portion and that is the protected object side of the third base fabric. And an exhaust port communicating with the first base cloth on the side opposite to the object to be protected, and the hanging string is connected to at least one of the first and third base cloths and the second base cloth. 2. The airbag according to claim 1, wherein a movement dimension of the second base cloth toward the protected object is restricted. 4. The closing part of the hanging string is formed integrally with the hanging string main body, and is capable of covering and removing the exhaust port in a state where a part of the hanging string main body is drawn out of the bag body from the exhaust port. 4. The airbag according to claim 1, wherein the airbag is positioned and held. 5. The closed portion of the hanging string, in the folded storage state, abuts on the edge of the exhaust port from the outside of the bag to cover the exhaust port. 4. The airbag according to claim 1, wherein the airbag is drawn inward. 6. The airbag according to claim 1, wherein the closing portion of the hanging string has a size that substantially covers the exhaust port.