JPH09164893A - Air bag and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To deposit a reinforcing body to an air bag cloth having no possibility of rupture by facilitating the thermal deposition of the reinforcing body to an uncoating type air bag cloth, and dissolving a remarkable difference in strength in a boundary between a thermally deposited part being apt to occur in the case of the thermal deposition and a fiber woven part adjacent to the deposited part SOLUTION: An air bag is bag-shapedly formed by joining the outer periphery 4 of a back cloth 3 composed of uncoating cloths where the circumferences of an inflater opening 6 drilledly provided at the about middle or of a vent opening 7 drilledly provided at the opening 6 and a proper position are joinedly reinforced with reinforcing bodies 8, 9 to the outer periphery 4 of a surface cloth 2 composed of the uncoating cloth being about the same in shape as the back cloth 3. In this case, the joining of the above reinforcing bodies 8, 9 to the back cloth is carried out by the thermal deposition (13A-13D) such as high frequency deposition.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a driver seat, a passenger seat,
Regarding an airbag device for a vehicle installed on a side surface, a rear seat, etc., an airbag reinforcing structure in which a plurality of reinforcing bodies are laminated and joined by thermal welding on a peripheral edge of an inflator opening and a peripheral edge of a vent opening, and manufacturing thereof Regarding the method.

[0002]

2. Description of the Related Art An airbag used for protecting an occupant of a vehicle is usually installed as an example in a driver's seat.
A back cloth positioned on the vehicle body side such as a handle and a front cloth positioned on the occupant side are joined together at their outer peripheral portions by sewing or the like to form a bag. Then, an inflator for inflating and deploying the airbag is inserted and installed in an inflator opening formed substantially in the center of the back cloth. At that time, a reinforcing cloth laminated in layers to reinforce the inflator opening is joined to the periphery of the inflator opening.
Generally, these reinforcing cloths are joined to the airbag cloth by suturing with a suture thread.
As disclosed in Japanese Laid-Open Patent Publication No. 54450, there has been developed one in which a reinforcing cloth is joined to an airbag cloth with an adhesive in order to improve workability and productivity.

Further, as shown in FIG. 3 of Japanese Patent Laid-Open No. 6-199198, a synthetic fiber is used because it is easy to manufacture and secures mechanical properties and air barrier properties. An airbag 21 composed of base fabrics 22 and 23 in which a thermoplastic elastomer is laminated on one side of the fabric, that is, an inflator opening 26 and a vent opening 27 of the airbag composed of the coated base fabric, through the elastomer. Layered body 2 of welded base cloth
It is also proposed that the laminates 28 and 29 are reinforced with 8 and 29 and are joined to the base fabric 23 by high frequency welding.

[0004]

However, in this conventional example, when the reinforcing cloth is joined to the air bag cloth by the adhesive as disclosed in the above-mentioned Japanese Patent Laid-Open No. 6-154450, the adhesive is fixed at a predetermined level. There is a risk that the reinforcing cloth may adhere to the airbag cloth before it is set to the correct position, and it takes a lot of time to bond it to the correct position, which is extremely troublesome to handle and the adhesive may dry. Due to variations in the process, there is a difference in the adhesive force between the reinforcing cloth and the airbag cloth due to the adhesive, and there is a possibility that the reinforcing cloth may peel off due to the high temperature and high pressure gas during the operation of the airbag. Also, in the so-called uncoated type airbag in which the airbag body cloth is not coated, the thermal welding of the reinforcing body to the airbag cloth is unsuitable and is not adopted. Since the reinforcement body disposed around the opening for use is usually joined to the airbag body cloth by stitching or the like, it takes time and labor for the stitching work, and due to the action of the high pressure gas on the reinforcement body when the airbag is deployed. There is also a risk that the load will be concentrated on the suture thread, resulting in damage.

Therefore, in the present invention, there are various problems in the reinforcing member laminated on the periphery of the inflator opening portion and the vent opening portion in the conventional airbag as described above, and in the joint portion of the airbag bag. To solve
It enables the heat welding of the reinforcement to the uncoated airbag fabric, and also improves the strength at the boundary between the heat-welded portion that tends to occur during heat-welding and the adjacent fiber woven fabric portion. (EN) Provided are an airbag capable of welding a reinforcing body to an airbag cloth without fear of breakage by eliminating a significant step, and a manufacturing method thereof.

[0006]

Therefore, according to the present invention, the inflator opening formed substantially at the center or the periphery of the inflator opening and the vent opening formed at an appropriate position are joined and reinforced by a reinforcing member. An airbag formed by joining an outer peripheral portion of a back cloth made of the uncoated woven fabric and an outer peripheral portion of a front cloth made of the uncoated woven fabric having substantially the same shape as the back fabric to form a bag-like back fabric of the reinforcing body. It is characterized in that it is joined by heat welding such as high frequency welding. Further, the present invention is characterized in that the reinforcing body is composed of an uncoated woven fabric, and at least both sides of a backing fabric made of the uncoated woven fabric are joined to each other by heat welding such as high frequency welding. It is what Further, the present invention relates to an outer peripheral portion of a backing cloth made of an uncoated woven fabric in which the periphery of an inflator opening formed substantially in the center and the periphery of a vent opening formed at an appropriate position are joined and reinforced with a reinforcing body. In an airbag formed by joining the backing cloth and a peripheral portion of a front cloth made of an uncoated woven fabric having substantially the same shape into a bag shape, when the reinforcing member is joined to the backing cloth by thermal welding such as high frequency welding. In addition, these are heat-welded at a welding temperature at which the woven structure of the back cloth is maintained. Furthermore, the present invention is characterized in that the reinforcing member is composed of an uncoated woven fabric, and at least both sides of a backing fabric made of the uncoated woven fabric are joined together by heat welding such as high frequency welding. It is a feature and these are means for solving the problems.

[0007]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a first embodiment of the present invention,
1 (A) is a perspective view showing a part of the airbag cut, and FIG. 1 (B) is an enlarged view of a main part of a cross section taken along the line AA of FIG. 1 (A). The airbag 1 comprises a front cloth 2 and a back cloth 3 made of an uncoated woven material such as nylon (nylon 6, nylon 66, etc.), polyester, polyimide, etc. having a substantially circular shape, and their outer peripheral portions are joined by stitching or the like. The outer peripheral joint portion 4 is formed to have a bag shape. On the other hand, in the vicinity of the inflator opening 6 bored at substantially the center of the back cloth 3 installed on the vehicle body side such as the handle and the vent opening 7 bored at an appropriate position, a multilayer of uncoated woven fabrics is similarly formed. The reinforcing bodies 8 and 9 composed of the laminated bodies 8A, 8B, 8C and 8D are joined to the back cloth 3 by thermal welding such as high frequency welding. Next, as shown in FIG. 1B, an inflator 5 for supplying high-pressure gas into the airbag 1 is inserted into the inflator opening 6, and the inflator 5 is fixed to a steering shaft (not shown) or the like. The back cloth 3 and the base plate 10, which are jointly reinforced by the reinforcing cloth 8, and the base plate 10 are sandwiched by the retainer 11 and are attached to the unit 10 with the mounting bolts 12.

In the present invention, the reinforcing member 8 is joined to the periphery of the inflator opening 6 formed at least substantially in the center of the back cloth 3, and further around the vent opening 7 formed at an appropriate position. The reinforcing bodies 9 to be joined to the air bag cloth are joined to the airbag cloth by heat welding such as high frequency welding.
Furthermore, in order to make these heat-welding more reliable, the heat-welding is carried out under a welding temperature condition in which at least the woven structure of the back cloth 3 made of the uncoated woven fabric such as nylon is maintained. This may exceed their melting points near the surface of the joint surface between the backing cloth 3 and the reinforcing bodies 8 and 9, but at a welding temperature for maintaining the internal woven structure, that is, a temperature lower than the melting point. The thermal welding is performed under such temperature conditions. As shown in FIG. 1B, a multi-layered laminate 8A, 8B, 8C of uncoated woven fabric such as nylon, which is joined to the front and back sides around the opening 6 for the inflator, which is bored at substantially the center of the back fabric 3. And 8
Before the assembling of the reinforcing member 8 made of D to the base plate 10, the welding for holding the woven structure of those cloths between the positive electrode and the negative electrode arranged in a required number in a concentric manner with the inflator opening 6 (not shown). It is heat welded by high frequency welding etc. at temperature, and the welded portions 13A, 13B,
13C and 14D are formed simultaneously or separately. As described above, since the reinforcing body 8 can be joined to the airbag body cloth made of the uncoated fabric by heat welding, the airbag adopting the uncoated body cloth having the improved productivity as in the conventional coating type is provided. It became possible. Further, since the welded portions 13A, 13B, 13C and 14D in these uncoated fabrics were heat-welded at the welding temperature for maintaining the woven texture of those fabrics, the fabric as a fiber woven fabric did not melt and solidify. Since it is not broken, there is no sudden structural change between the welded part and the fiber woven fabric that is in contact with the welded part, and a significant difference in strength is eliminated, and there is no risk of breakage at this boundary line.

Generally, the heat-welding strength is higher when heat-welding is performed at a temperature higher than the melting points of these cloths.
In particular, at least the outermost weld portion 13A on which the greatest force acts when the airbag 1 is inflated and deployed needs to be heat-welded at the welding temperature at which the woven structure of the cloth is maintained. However, if the welding strength can be secured, heat welding may be performed at a temperature lower than the melting point of the cloth at all the welding parts, or near the surface of the joint surface between the back cloth 3 and the reinforcing bodies 8 and 9. However, the melting point may be higher than these melting points, but the welding may be performed at a temperature lower than the melting temperature, that is, the melting temperature held by the internal woven structure. In the present embodiment, it is preferable that both the front and back cloths 2 and 3 constituting the airbag and the reinforcing bodies 8 and 9 are made of the same quality uncoated woven fabric such as nylon. Utilizing the characteristic that the strength of is relatively high,
In practice, sufficient adhesive strength can be obtained.

FIG. 2 shows a second embodiment of the present invention. FIG. 2 (A) is a reinforcement of an uncoated fabric, and FIG. 2 (B).
[Fig. 3] is an enlarged view of a main part of the one using a coating reinforcing body. In the present embodiment, the reinforcement body joined around the inflator opening and the vent opening is made of an uncoated fabric, and at least both sides of the backing fabric made of the uncoated fabric are provided with a welding film. The joining is performed by heat welding such as high frequency welding. In the example of FIG. 2A, the back cloth 3 made of uncoated woven fabric such as nylon (nylon 6, nylon 66, etc.), polyester, polyimide, etc. is joined to the front and back sides of the back cloth 3 around the inflator opening. A film made of a urethane-based, polyester-based, polyamide-based thermoplastic elastomer or a nylon film, a welding film made of polyethylene terephthalate, or the like is interposed between the reinforcing bodies 8 made of uncoated woven fabric, and these are woven of these cloths. It is heat-welded by high-frequency welding or the like at a welding temperature for holding the tissue. As a result, due to the inclusion of the welding film, which is relatively excellent in high-frequency heat-welding properties,
This makes it possible to join the airbag body cloth and the uncoated woven fabric of the reinforcing body to each other moderately and strongly without breaking them.

In the example of FIG. 2B, the back cloth 3 is made of uncoated woven fabric such as nylon (nylon 6, nylon 66, etc.), polyester, polyimide, etc., but is joined to the front and back sides around the inflator opening. Although each reinforcing body 8 itself is made of an uncoated woven fabric, a reinforcing layer 8U made of urethane or the like is stretched around the reinforcing body 8. A urethane film or a nylon film is provided between the back cloth 3 and the reinforcing body 8. Alternatively, a welding film made of a polyethylene film or the like is interposed, and these are heat-welded by high-frequency welding or the like at a welding temperature that maintains the woven structure of those cloths. As a result, like the above-mentioned example, the presence of the welding film, which is relatively excellent in high-frequency heat-welding properties, enables the airbag body cloth and the uncoated woven fabric of the reinforcing body to be appropriately and strongly bonded without breaking them. become. It should be noted that the reinforcing bodies 8 and 9 are not limited to uncoated woven fabrics and urethane stretched woven fabrics, but may be composed of a urethane film or the like alone.

In the present invention, not only the joining of the reinforcing cloth 8 at the inflator opening 6 and the vent opening 7 described above, but also the heat welding at the outer peripheral joining portion 4 of the front cloth 2 and the back cloth 3 is made of nylon or the like. It is also possible to perform heat welding at a welding temperature that maintains the woven structure of the front and back cloths 2 and 3 made of uncoated woven fabric.

Although the embodiments have been described above, the shape of the reinforcing body (the reinforcing cloths do not necessarily have to have the same shape and the same size), the number of sheets, and the like within the scope of the gist of the present invention.
Materials and their combination, the shape of the cloth on the front and back (a shape adapted to the part to which the airbag is applied is adopted),
It goes without saying that the material, the method of heat welding, the joining form of the reinforcing body to the airbag cloth, the attaching form of the airbag cloth to the base plate, and the like can be appropriately adopted.

[0014]

As described above in detail, in the present invention, the back cloth is joined at least around the center of the inflator and around the vent opening formed at an appropriate position. By performing heat welding such as high-frequency welding on each reinforcing cloth, it is possible to further improve the productivity of the uncoating type airbag with excellent workability,
Further, if the heat welding is carried out at a welding temperature that maintains the woven structure of the reinforcing cloth made of uncoated woven fabric such as nylon and the front and back cloths, at least the inside of each welding portion is heat welded at a temperature lower than the melting point, Since the structure of the woven cloth has not been melted and solidified and has not been destroyed, there is no sudden structural change between the welded part and the fiber woven cloth that touches the boundary, and a significant difference in strength is eliminated, and this boundary line There is no breakage at any time. In this way, by utilizing the characteristic that the strength of heat welding between homogeneous materials is relatively high, it is possible to secure a practically sufficient adhesive strength without destroying the structure of the welded portion. Further, if a welding film having a relatively high-frequency heat-welding property is interposed between the reinforcing cloth made of uncoated fabric and the airbag body cloth, the airbag body cloth and the uncoated fabric of the reinforcing body are not destroyed. It becomes possible to join these with moderate strength. Further, when at least one layer of the welding film or the urethane-bonded synthetic fiber woven fabric is welded to the opening for the inflator inside the airbag, high temperature gas can be prevented by the film layer as compared with the sewn airbag made of the uncoated woven fabric. Therefore, it is possible to prevent damage to the back cloth.

[Brief description of the drawings]

FIG. 1 is an overall view showing a partially cutaway view of an airbag according to a first embodiment of the present invention and a cross-sectional view of a main part.

FIG. 2 is a cross-sectional view of main parts showing an airbag according to a second embodiment of the present invention.

FIG. 3 is an overall view showing a conventional airbag partially cut away.

[Explanation of symbols]

 1 Airbag 2 Front cloth 3 Back cloth 4 Outer peripheral joint 5 Inflator 6 Inflator opening 7 Vent opening 8 Reinforcing cloth (inflator opening) 8U Tension layer 9 Reinforcing cloth (vent opening) 10 Base plate 11 Retainer 12 Mounting bolt 13 Welding part 14 Welding film

Claims (4)

[Claims] 1. A backing cloth made of an uncoated woven fabric, in which an opening for an inflator formed substantially in the center or the periphery of the opening for an inflator and a vent opening formed at an appropriate position are joined and reinforced by a reinforcing body. In an airbag formed by joining an outer peripheral portion and an outer peripheral portion of a front cloth made of an uncoated woven fabric having substantially the same shape as the back cloth, in a bag shape, the reinforcing member is joined to the back cloth by thermal welding such as high frequency welding. An airbag characterized by being performed by. 2. The reinforcing body is composed of an uncoated woven fabric, and at least both sides of a backing fabric made of the uncoated woven fabric are joined together by heat welding such as high-frequency welding. The airbag according to claim 1, wherein: 3. An outer peripheral portion of a backing cloth made of an uncoated woven fabric in which the periphery of an inflator opening formed substantially at the center and the periphery of a vent opening formed at an appropriate position are joined and reinforced by a reinforcing body. In an airbag formed by joining the backing cloth and a peripheral portion of a front cloth made of an uncoated woven fabric having substantially the same shape into a bag shape, when the reinforcing member is joined to the backing cloth by thermal welding such as high frequency welding. In addition, the method for producing an airbag is characterized in that the heat welding is performed at a welding temperature at which the woven structure of the backing cloth is retained. 4. The reinforcing body is composed of an uncoated woven fabric, and at least both sides of a backing fabric made of the uncoated woven fabric are joined to each other by heat welding such as high frequency welding. The method for manufacturing an airbag according to claim 3.