JPH09119066A - Air bag - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an air bag, having an air bag front fabric mutually joined to a back fabric, excellent in adhesion and having a high strength and a thermoplastic film such as a urethane on the joining surface according to a simple joining method. SOLUTION: This air bag 1 is obtained by interposing a bonding reinforcing layer 12 comprising a thermoplastic film such as a urethane forming a high-frequency welding insulating layer 13 in an interlayer on the central side of the air bag 1 from the outer peripheral joining part 4 between thermoplastic films 2U and 3U in the joining area of mutual air back front fabric and back fabric 2 and 3 in which the thermoplastic films 2U and 3U such as urethane are laminated in at least the joining area of an outer peripheral joining part 4 of the front fabric 2 constituting the baglike air bag 1 and the back fabric 3 and mutually joining the air bag front and back fabrics 2 and 3 by carrying out the thermal welding such as high-frequency welding of the joining surface 4.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air bag having a lightweight and high mechanical strength thermoplastic film of urethane or the like, which joins an outer surface and a backing of the air bag.

[0002]

2. Description of the Related Art An airbag mounted on a steering wheel, a passenger seat, a door, a rear seat or a ceiling of an automobile and used for protecting an occupant is usually an airbag obtained by coating silicon, rubber, or the like with a woven fabric coated and crosslinked. It is manufactured by cutting the base fabric for a bag and sewing it into a bag shape. In addition, the airbag is provided with an opening for an inflator to be attached to a base plate facing the gas generator and an opening for a vent for effectively absorbing impact,
In order to reinforce the periphery of these openings, a reinforcing cloth of the same member as the airbag is sewn. In recent years, airbag fabrics in which various synthetic resin layers have been laminated have been proposed as materials for reducing the weight of airbags, improving mechanical strength, and reducing deterioration over time. Thermal welding by welding or the like is performed. For example, Japanese Patent Application Laid-Open (JP-A) No. 2-114035 and Japanese Patent Application Laid-Open (JP-A) No. 2-1
No. 62134, JP-A-3-7337, JP-A-6-19
There is a conventional example as described in JP-A-9198.

[0003] One of these will be described with reference to FIG.
The airbag 21 as shown in FIG.
And the backing fabric 23 are joined at the joining portion 24 to form a bag. Reference numeral 26 denotes a gas inlet. As shown in FIG. 7 (A), each of the above fabrics has a polyester resin layer 22B laminated via a primer coat layer 22A. And these front and back fabrics 22 and 23 are shown in FIG.
As shown in FIG. 7, the polyester resin layers 22B and 23B are brought into contact with each other at a joint 24 and heat-welded. As a result, it is possible to join the joint portion 24 with excellent hardness and bendability, and with excellent adhesive strength between the fabric and the resin layer and excellent welding strength between the resin layers. However, such a joint 2
In 4, the airbag 21 is inflated and
As shown in FIG. 7B, the layers 2 and 23 are separated from each other, and a large peeling force acts between the layers of the joint 24. Since the welding strength (peeling strength) between the polyester resin layers 22B and 23B is considerably high, the polyester resin layers 22B and 23B
Although there is no risk of peeling between the fabrics 22 (2
Since the peel strength between 3) and the primer coat layer 22A (23A) is not so high, there is a possibility that peeling may occur between the layers.

[0004] In order to prevent peeling between the synthetic resin layer and the cloth at the joint surface where the airbag cloths laminated with such a synthetic resin layer are joined together by thermal welding, the above-mentioned Japanese Patent Application Laid-Open No. Hei. The thing shown in 162134 was proposed. Referring to FIG. 8, the airbag 31 includes two base cloths 32 and 33 each having at least one surface coated with rubber or a thermoplastic resin, and the surface coated with the rubber or the thermoplastic resin is on the inner side. The reinforcing cloth 34 covered with the same covering material as that of the base cloth is interposed between the outer peripheral ends of the base cloths and heat-welded. As a result, the force in the peeling direction in which the front and back base fabrics 32 and 33 are separated from each other is increased by the reinforcing cloth 34.
And the base fabrics 32 and 33 receive the force in the shearing direction to increase the strength at the joint surface.

[0005]

However, the interposition of such a reinforcing cloth 34 requires the front and back base cloths 32, 33 to be provided along a plane which is substantially perpendicular to the joint surface. Is two-dimensional, but the reinforcing cloth 34 must be three-dimensionally arranged and joined.
For this reason, the heat welding, for example, a high-frequency welding device or the like becomes complicated. In addition, since the reinforcing cloth 34 is a tubular body, its production is troublesome. In addition, there is a problem that if it is attempted to forcibly join in two dimensions, wrinkles remain on the joining surface.

Therefore, the present invention solves the problems in the conventional airbag as described above, and uses a simple joining method to provide excellent adhesiveness and high strength of the joint portion, such as urethane on the joint surface. There is provided an airbag in which an airbag outer material and a lining material having the thermoplastic film are joined.

[0007]

Therefore, in the present invention, as a means for solving the above-mentioned problems, as a means for solving the above-mentioned problems, a thermoplastic material such as urethane is provided on at least the joint surface of the outer peripheral joint portion of the outer lining and the lining constituting the bag-shaped airbag. A film made of a thermoplastic film such as urethane having a high-frequency welding insulating layer formed in an intermediate layer on the airbag center side from the outer peripheral joint between the thermoplastic films on the joint surface between the air bag outer layer and the lining. This is characterized in that the air bag outer material and the lining material are joined together by heat welding such as high-frequency welding on the joint surface with an adhesive reinforcing layer interposed, and this is a means for solving the problem. Further, the present invention is characterized in that the outer material and the lining are made of a thermoplastic film such as urethane. Further, the present invention is characterized in that the front and back fabrics and a thermoplastic film such as urethane laminated on them are integrally formed. Further, in the present invention, the adhesion reinforcing layer may be formed from a thermoplastic film such as urethane or a two-layered base cloth laminated on both sides with a thermoplastic film such as urethane. A high frequency welding insulation layer may be formed between the separation layers of the Y-shaped cross section of the thermoplastic film, and the adhesive reinforcement layer may be formed by cutting a tape-shaped body having slits formed on one side at predetermined intervals into a circular shape. They may be formed by connecting them, and these are used as means for solving the problems.

[0008]

In the present invention, the outer surface of the airbag 2 and the lining 2 in which the thermoplastic films 2U and 3U of urethane or the like are laminated on at least the joint surfaces of the outer peripheral joint portion 4 of the outer cloth 2 and the lining 3 which constitute the bag-shaped airbag, Adhesion reinforcement made of a thermoplastic film such as urethane in which a high frequency welding insulating layer 13 is formed in an intermediate layer closer to the center of the airbag 1 than the outer peripheral joint 4 between the thermoplastic films 2U and 3U on the joint surface of the three members. Electrode 14 is applied to the airbag outer material and linings 2 and 3 by high frequency welding with layers 12A and 12B interposed.
Since A and 14B are joined by thermal welding such as high frequency welding, the thermoplastic film 2U and the adhesive reinforcing layer 12C and the thermoplastic film 3U and the adhesive reinforcing layer 12D are provided in the range where the high frequency welding insulating layer 13 is formed. Although firmly welded, the adhesive reinforcing layers 12C and 12D are separated without being welded, and the thermoplastic films 2U and 3U and the adhesive reinforcing layers 12A and 12 are separated in a range excluding the insulating layer.
The layers of B are integrally and firmly welded.

Thus, when the airbag 1 to which the joint portion is heat-welded is operated and inflated by the introduction of the high-pressure gas from the inflator 5, even if the joint surface is separated by the outer material and the linings 2, 3, which are separated from each other, This is not allowed by the strong welding between the adhesive reinforcing layers 12A and 12B at the joint surface, and the adhesive reinforcing layers 12C and 12D in the range of the insulating layer are firmly welded to the outer and lining 2, 3 sides. Between the surface material 2 and the thermoplastic film 2U having the same behavior and the peeling direction changed to the shearing direction, and the lining 3
And the thermoplastic film 3U can also be effectively prevented from being separated. And the thermoplastic film 2U,
The outer and inner linings 2, 3 laminated with 3U, the adhesive reinforcing layers 12A, 12B, and the insulating layer 13 need only be laminated in layers between the electrodes 14A, 14B installed in parallel, and the outer peripheral portion is welded at one time. And the joining device itself has a simple structure.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a first embodiment of an airbag according to the present invention, in which an airbag 1 is a pair of substantially circular outer material cut from a base cloth and a surface made of nylon, polyester resin or the like as a lining material. The cloth 2 and the back cloth 3 face each other and are polymerized, and are joined at the outer peripheral joint portion 4 to form a bag shape. As shown in FIG. 1 (A), an inflator 5 is mounted at substantially the center of the backing cloth 3 to supply high-pressure gas into the airbag 1 by operating upon detection of deceleration or the like when an accident is encountered. An inflator opening 6 is formed, and a vent opening 7 is formed in an appropriate portion of the backing cloth 3 in order to effectively absorb the impact of the airbag 1. Reinforcing cloths 8 and 9 are joined around the inflator opening 6 and the vent opening 7, respectively. The peripheral edge of the inflator opening of the back cloth 3, the reinforcing cloth 8 of the inflator opening 6 and the mounting flange of the inflator 5 are fixed to the base plate 10 fixed to the steering shaft or the like via the retainer 11 by a through bolt or the like not shown. It

FIG. 1 is an enlarged cross-sectional view of a portion A in FIG.
As shown in (B), the front cloth 2 and the back cloth 3 constituting the bag-shaped airbag 1 are each formed by laminating thermoplastic films 2U, 3U such as urethane on the inside, that is, on the side to be the joining surface. I have. In general, in recent years, various synthetic resin layers have been laminated on the entire inner surface of a relatively thin cloth constituting an airbag as a material for reducing the weight of the airbag, improving mechanical strength, and reducing deterioration over time. Then, a laminate in which a synthetic resin layer is laminated only near the joining surface may be used.

As described above, the front cloth 2 and the back cloth of the airbag 1 in which the thermoplastic films 2U and 3U such as urethane are laminated on at least the joining surfaces of the front cloth 2 and the back cloth 3 constituting the bag-shaped airbag. 3 will be described by taking the outer peripheral joint portion 4 of the airbag 1 as an example. In the present embodiment, the positive electrode 14A and the negative electrode 14B, which are arranged substantially in parallel at an interval above and below, are connected. In between, thermoplastic film 2
U and 3U are opposed to each other, and the front and back cloths 2 and 3 are set to face each other. A material which can satisfy the same adhesive strength as the thermoplastic film 2U and 3U between the front and back cloths 2 and 3 Adhesion reinforcing layers 12A and 12B made of a thermoplastic film such as urethane are interposed. At that time, airbag 1
Is located on the center side (inside in the radial direction) of the airbag 1, that is, a part of a predetermined range on the side where the front and back cloths 2 and 3 are separated and peeled off when the airbag 1 is inflated. It is a thing which was pinched. Here, the high-frequency welding insulating layer is paper, a Teflon film, an olefin resin film, or the like. As a result, as shown in FIG. 1B, the positive electrode 14A and the negative electrode 14B are brought close to each other as shown by arrows, and are thermally welded by high-frequency welding or the like.
Except for the non-adhesion between the adhesive reinforcing layers 12C and 12D in the range where the high-frequency insulating layer 13 is sandwiched, the members at the outer peripheral joint 4 can be firmly joined.

As a result, as shown in FIG. 1 (C), the airbag 1 having the outer peripheral joint portion 4 heat-sealed is attached to the inflator 5.
When the working surface expands due to the introduction of high-pressure gas from the surface, even if the joining surface is about to be separated by the front and back cloths 2 and 3, which are separated from each other, this is allowed by the strong welding between the adhesion reinforcing layers 12A and 12B at the joining surface. In addition, the adhesive reinforcing layers 12C and 12D in the range of the insulating layer are firmly welded to the front and back cloths 2 and 3 to have the same behavior, and the peeling direction is changed to the shearing direction and the thermoplastic film and the front cloth 2 are changed. Separation between 2U and between the back cloth 3 and the thermoplastic film 3U is also effectively prevented. And, the thermoplastic films 2U, 3U
Front and back cloths 2 and 3 laminated with each other, an adhesion reinforcing layer 12A,
12B and the insulating layer 13 are provided with electrodes 14 arranged in parallel.
Only the layers A and 14B need to be laminated in a layered manner, and the outer peripheral portion can be welded at a time and easily joined, so that the joining device itself has a simple structure. Note that a nylon film or a polyester film may be used instead of the front and back cloths 2 and 3.

FIG. 2 shows a second embodiment of the present invention. FIG. 2 is an enlarged sectional view of a portion A in FIG. While the adhesive reinforcing layer 12 of the first embodiment is formed by two layers, the adhesive reinforcing layer 12 of the present embodiment is used as the outer and inner linings when the airbag 1 is inflated. A predetermined area on the side where the cloths 2 and 3 are separated and peeled off is made of a thermoplastic film such as urethane having a substantially Y-shaped cross section formed on the separation layers 12C and 12D by the cutouts 15, and the Y-shaped cross section is formed. Separation layer 1 in
A high frequency welding insulating layer 13A such as an olefin resin is formed in advance between 2C and 12D by coextrusion molding or the like. The adhesive reinforcing layer 12 may be formed by continuously forming a thermoplastic film such as urethane having a Y-shaped cross section in a form in which a high-frequency welding insulating layer 13A is previously laminated by a coextrusion molding method or the like. A high-frequency welding insulating layer 13A such as paper, a Teflon film or an olefin resin film may be laminated and fixed to a thermoplastic film such as urethane having a letter-shaped cross section later. With this configuration, the operation of sandwiching the insulating layer during the high frequency welding operation can be omitted, and the operation efficiency is further improved.

FIG. 3 shows a third embodiment of the present invention, and is an enlarged sectional view corresponding to a portion A in FIG. The present embodiment is characterized in that each of the adhesion reinforcing layers 12A and 12B is made of a two-layer base cloth having a thermoplastic film 12U such as urethane laminated on both sides. As a result, similarly to the first embodiment, when the airbag 1 to which the outer peripheral joint portion 4 is heat-welded is inflated by the introduction of high-pressure gas from the inflator 5, the front and back cloths 2, 3 which are separated from each other. Even if the bonding surface is to be peeled off, the peeling direction is not allowed, and the separation between the front cloth 2 and the thermoplastic film 2U and the separation between the back cloth 3 and the thermoplastic film 3U in which the peeling direction is changed to the shearing direction are performed. Also effectively prevent.

FIG. 4 shows a fourth embodiment of the present invention. As shown in FIG. 4A, a tape-like body having a large number of slits cut at predetermined intervals on one side is formed in a circular shape. As shown in FIG. 4 (B), a thermoplastic film such as urethane or a base fabric laminated with a thermoplastic film such as urethane on both sides is formed to have a size substantially equal to the joining circle of the outer peripheral portion of the airbag. As shown in FIG. 4 (C), two sheets formed in a ring shape are superimposed, and as shown in FIG. 4 (C), an insulating layer 13 is interposed between the outer peripheral joint 4 and the intermediate layer on the center side of the airbag. And the back cloth 3. As a result, the same effects as those of the first embodiment can be obtained. However, in the present embodiment, a flat and ring-shaped adhesive reinforcing layer can be easily obtained, so that its manufacture is inexpensive.

FIG. 5 shows a fifth embodiment of the present invention, in which a thermoplastic film such as urethane is used in place of the cloth as the outer material 2 and the lining 3 constituting the bag-shaped airbag. It is. As shown in FIG. 5 (A), at least the joining surface between the outer fabric 2 and the lining 3 made of a thermoplastic film such as urethane instead of the fabric constituting the bag-shaped airbag has the same shape as the outer fabric and the lining. A thermoplastic film 2U, 3U made of urethane or the like is laminated, and the thermoplastic film 2U is placed between a positive electrode 14A and a negative electrode 14B, which are arranged substantially in parallel with the outer peripheral joint portion 4 and vertically spaced apart from each other. The surface material and the linings 2 and 3 are set to face each other with the 3U facing each other, and a material which can satisfy the same adhesive strength as the thermoplastic film 2U and 3U between the surface materials and the linings 2 and 3 is used. Adhesion reinforcing layers 4U, 4U made of a thermoplastic film such as urethane are interposed. At this time, similarly to FIG. 1 described above, an insulating layer 13 is sandwiched as an intermediate layer to be a high-frequency welding insulating layer in a part of a predetermined range on the center side of the airbag 1. Then, the positive electrode 14A and the negative electrode 14B are brought close to each other as shown by arrows and heat-welded by high-frequency welding or the like, whereby the adhesive reinforcing layers 4A and 4B in the range where the high-frequency insulating layer 13 is sandwiched are provided.
The members at the outer peripheral joint portion 4 can be firmly joined except for non-welding between them.

As a result, as shown in FIG. 5 (B), the airbag 1 with the outer peripheral joint portion 4 heat-welded is attached to the inflator 5.
When the joint expands due to the outer material and the linings 2 and 3 that are separated from each other during the operation expansion due to the introduction of the high-pressure gas from the surface, the adhesion reinforcing layers 4U and 4U at the joint surface
The adhesion reinforcement layers 4A and 4B in the area of the insulating layer are firmly welded to the surface material and the linings 2 and 3 so as to have the same behavior, and the peeling direction is sheared. Outer fabric 2 and thermoplastic film 2U converted in direction
And between the backing 3 and the thermoplastic film 3U are also effectively prevented. Moreover, in the present embodiment, the outer material and the linings 2, 3 and the films 4U, 4U laminated thereon are made of a thermoplastic film such as urethane of the same material, and the heat welding property between them is extremely high. There is no fear of peeling. Each of the outer and lining materials 2 and 3 laminated with the thermoplastic films 2U and 3U, the adhesive reinforcing layers 4U and 4U, and the insulating layer 13
It is only necessary to laminate the electrodes 14A and 14B in a layered manner between the electrodes 14A and 14B. The outer peripheral portions can be welded at a time and easily joined, and the joining device itself has a simple structure. In addition, an ester thermoplastic elastomer, an amide thermoplastic elastomer, or the like may be used as the surface and backing film, in addition to a thermoplastic elastomer such as urethane. Thermoplastic resins such as polyamide, polyester, polycarbonate, and polyimide are also preferably used.

FIG. 6 shows a sixth embodiment of the present invention, which is the same as the fifth embodiment, except that the surface and lining and the thermoplastic film such as urethane laminated on them are laminated. 2U and 3U are integrally formed to form the outer material 2 and the inner material 3, that is,
As shown in FIG. 6A, a dress material 2 and a lining material 3 made of a thermoplastic film such as urethane constituting a bag-shaped airbag.
The front and back films 2 and 3 between the joining surfaces of the outer peripheral joining portion 4
Adhesive reinforcing layers 4U, 4U made of a thermoplastic film of urethane or the like of the same quality as above are arranged in a state where they are opposed to each other as a bonding material, and an outer peripheral bonding portion 4 of these front film 2 and back film 3 is arranged.
The adhesive reinforcing layers 4U and 4U are set between the positive electrode 14A and the negative electrode 14B which are arranged substantially in parallel at intervals above and below, and a part of a predetermined range on the center side of the airbag 1 An insulating layer 13 is sandwiched as an intermediate layer serving as a welding insulating layer. As a result, as shown in FIG. 6A, the positive electrode 14A and the negative electrode 14B are brought close to each other as shown by arrows and heat-welded by high-frequency welding or the like, thereby bonding the high-frequency insulating layer 13 in the sandwiched area. Except for non-welding between the thermoplastic films 4A and 4B as the reinforcing layers, the members at the outer peripheral joint 4 can be firmly joined.

As a result, as shown in FIG. 6 (B), when the airbag having the outer peripheral joint portion 4 thermally welded is operatively inflated by the introduction of the high pressure gas from the inflator, the films 2 on the front and back sides are separated from each other. 3. Even if the joint surface is peeled off by 3, the strong adhesion between the thermoplastic films 4U and 4U as the adhesion reinforcing layer on the joint surface does not allow this, and the thermoplastic film 4 in the range of the insulating layer is not allowed.
A and 4B are firmly welded to the front and back films 2 and 3 and have the same behavior, and between the front film 2 and the thermoplastic film 4U whose peeling direction has been changed to the shearing direction, and between the back film 3 and the thermoplastic film. The peel strength between the thermoplastic films 4U and 4U as the bonding material, which is the adhesive reinforcing layer, is increased by the strong proof stress in the shear direction between 4U and 4U.

Although the respective embodiments of the present invention have been described above, within the scope of the spirit of the present invention, the joining forms of the outer material and the inner material of the airbag, the materials thereof, the material of the resin layer to be laminated, and the lamination. The method, the material of the insulating layer, the material and shape of the adhesion reinforcing layer, the material and shape of the insulating layer, the laminating method, the laminating form of the reinforcing cloth for the inflator opening and the vent opening, and the like can be appropriately adopted.

[0022]

As described in detail above, according to the present invention, an airbag in which a thermoplastic film such as urethane is laminated on at least the joint surface of the outer peripheral joint portion of the outer material and the lining constituting the bag-shaped airbag. Between the thermoplastic films on the joint surface between the outer material and the lining, an adhesive reinforcing layer made of a thermoplastic film such as urethane having a high frequency welding insulating layer formed in the intermediate layer on the airbag center side from the outer peripheral joint is interposed. Since the air bag surface and lining are joined by heat welding such as high frequency welding between the electrodes by high frequency welding, the thermoplastic film and the adhesive reinforcing layer are firmly welded in the range where the high frequency welding insulating layer is formed. However, the adhesive reinforcing layers are separated without welding, and the thermoplastic film and the adhesive reinforcing layer are provided in a range excluding the insulating layer. Since the layers are integrally and firmly welded together, even if the joining surface is peeled off by the front and backing layers that separate from each other when the airbag, whose joints are heat-welded, is inflated by the introduction of high-pressure gas from the inflator. This is not allowed due to the strong welding of the adhesion reinforcing layers on the surface, and each adhesion reinforcing layer in the range of the insulating layer firmly adheres to the outer and lining sides and behaves together, and the peeling direction is in the shearing direction. Separation between the converted surface material and the thermoplastic film and between the backing material and the thermoplastic film can also be effectively prevented. Further, if the outer material and the lining and the film laminated thereon are made of a thermoplastic film such as urethane of the same material, the heat welding property between them is even higher, and there is no fear of peeling. Then, each surface and lining laminated with the thermoplastic film, the adhesion reinforcing layer and the insulating layer may be laminated only in layers between the electrodes arranged in parallel,
The outer peripheral portion can be welded at once and can be easily joined only by linearly moving the electrode, and the joining device itself has a simple structure.

[Brief description of the drawings]

1 shows a first embodiment of an airbag according to the present invention, and FIG. 1 (A) is an overall view of an airbag device, FIG.
(B) and (C) are enlarged cross-sectional views of main parts.

FIG. 2 is an enlarged cross-sectional view showing a second embodiment of the airbag according to the present invention and corresponding to a portion A which is a main part of FIG. 1 (A).

FIG. 3 shows a third embodiment of the airbag according to the present invention.

FIG. 4 shows a fourth embodiment of the airbag according to the present invention.

FIG. 5 shows a fifth embodiment of the airbag according to the present invention.

FIG. 6 shows an airbag according to a sixth embodiment of the present invention.

FIG. 7 is a view showing a first conventional example of an airbag.

FIG. 8 is an enlarged view of a main part showing a second conventional example of an airbag.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Air bag 2 Outer fabric 2U Thermoplastic film 3 Lining 3U Thermoplastic film 4 Perimeter joint 4U Adhesive reinforcement layer 5 Inflator 6 Inflator opening 7 Vent opening 8 Reinforcing cloth (Inflator opening) 9 Reinforcing cloth (Vent opening) 10 Base plate 11 Retainer 12 Adhesion reinforcement layer 12A Adhesion reinforcement layer 12B Adhesion reinforcement layer 12C Separation layer 12D Separation layer 13 High frequency welding insulation layer 13A Insulation layer 14 Electrode 15 Cut part

Claims (6)

[Claims] 1. An air bag outer material in which a thermoplastic film such as urethane is laminated on at least the joint surface of the outer peripheral joints of the outer material and the lining constituting a bag-shaped airbag, and between the thermoplastic films on the joint surface of the linings. In addition, an adhesive reinforcing layer made of a thermoplastic film such as urethane having a high frequency welding insulating layer formed on an intermediate layer closer to the center of the airbag than the outer peripheral joint portion is interposed, and the joint surface is thermally welded by high frequency welding or the like to the airbag. An airbag characterized by joining the outer material and the lining material together. 2. The airbag according to claim 1, wherein the outer material and the inner material are made of a thermoplastic film such as urethane. 3. The airbag according to claim 2, wherein the outer material, the inner material, and a thermoplastic film such as urethane laminated on the outer material and the inner material are integrally formed. 4. The airbag according to any one of claims 1 to 3, wherein the adhesion reinforcing layer is made of a two-layer base cloth having thermoplastic films such as urethane laminated on both sides thereof. 5. The adhesion reinforcing layer is made of a thermoplastic film such as urethane having a substantially Y-shaped cross section, and a high frequency welding insulating layer is formed between the separation layers in the Y-shaped cross section. The airbag according to any one. 6. The adhesive reinforcing layer is formed by connecting tape-shaped bodies, each of which has slits cut into one side at predetermined intervals, in a circular shape. Airbag.