JPH02175352A - Manufacture of air bag - Google Patents

Abstract

PURPOSE:To simplify manufacture of an air bag free from gas leakage from a suture by a method wherein a periphery of two pieces of upper and lower bag materials provided with heat-resistant rubber layer provided on inner sides of opposite faces is sutured, and a specific protection cover is adhered so that an entire periphery of the inner face of the suture is covered. CONSTITUTION:As a portion to be an inner face of an air bag 11 made of material cloths 2a,3a made of elastic woven cloth such as nylon and polyester, bag materials 2,3 in approximate circular shapes with heat-resistant rubber layers 2b,3b by coating it with heat-resistant rubber are prepared. The air bag 11 is constituted by suturing these materials 2,3 with thread 4 such as nylon. At this time, a protection cover 17 for covering the suture is adhered to an entire periphery of the inner face at the suture of the bag materials 2,3. This protection cover 17 is formed by a divided body made by dividing a tuber body 18 made of a reinforced rubber hose having a braided reinforcing layer 19 between an inner tube layer 20 and an outer tube layer 21 along an axial direction.

Description

[Detailed Description of the Invention] <Industrial Application Field> This invention is used for an airbag device installed in a vehicle, and when used, gas from a gas generator is injected into the inside of the airbag device. The present invention relates to a method of manufacturing an inflatable airbag.

<Prior Art> Conventionally, an airbag 1 is manufactured by sewing together the peripheral edges of two upper and lower approximately circular bag base materials 2 and 3 with a suture thread 4 made of nylon or the like, as shown in FIG. If the suture thread 4 is exposed, the suture thread 4 may melt due to the initial heat generated when the gas is rapidly injected inside. Protective covers 5 and 5 made of silicone tape with adhesive properties are attached to two upper and lower bag base materials 2.
・It has been proposed to manufacture the adhesive by adhering it to each of the sutured parts of No. 3 (see Japanese Utility Model Publication No. 85549/1983).

In addition, in this type of airbag 1, the bag base materials 2 and 3 are made of flexible woven fabrics such as nylon and polyester as base fabrics 2a and 3a, and the airbag l of each base fabric 2a and 3a is Heat-resistant rubber layers 2b and 3b coated with heat-resistant butyl rubber, chloroprene rubber, or the like are formed on the inner peripheral surface side.

<Problem to be solved by the invention> However, it is difficult to adhere the protective covers 5, 5 made of silicone tape to the bag base materials 2, 3, and the cost of the silicone tape itself is high. This would increase manufacturing man-hours and manufacturing costs.

In addition, in the conventional adhesive bonding of the protective covers 5 and 5, the protective covers 5 and 5 are separately attached to the upper and lower bag base materials 2 and 3 at the suture site.
When gas is injected into the airbag 1, the gap between the seams of the upper and lower bag base materials 2 and 3 at the sutured site expands, causing the upper and lower bag bases other than the discharge hole to It was not possible to prevent gas from escaping out of the airbag 1 from between the seams of the seamed parts of materials 2 and 3. In addition, if this gas leakage is large, the suture thread 4 will be damaged by the high temperature gas.
There was also a risk that the base fabrics 2a and 3a would be fused.

This invention solves the above-mentioned problems, and provides an airbag manufacturing method that can prevent gas leakage from the part where the upper and lower bag base materials are sewn together, and can reduce manufacturing man-hours and manufacturing costs. The purpose is to provide

Means for Solving the Problems> The method for manufacturing an airbag according to the present invention involves sewing together the peripheries of two upper and lower bag base materials each having a heat-resistant rubber layer on the inner surface of the opposing surface to form a bag. A method of manufacturing an airbag includes forming a protective cover and adhering a protective cover so as to cover the entire circumference of the inner peripheral surface of the sutured part, the protective cover being attached to an inner tube with a braided reinforcing layer as an intermediate layer. A tubular body was formed by extrusion molding, in which the layers were made of heat-resistant rubber and the outer tube layer was made of the same type of rubber as the heat-resistant rubber layers of the upper and lower bag base materials or rubber with good mutual adhesion. After that, the tubular body is divided along the axial direction to form a divided body, and the outer tube layer side of the divided body is attached to the upper and lower two bag base materials all around the inner peripheral surface side of the sutured part. It is characterized in that it is manufactured by adhering it across.

<Operations and Effects of the Invention> In the method for manufacturing an airbag according to the present invention, the intermediate layer is provided with a braided reinforcing layer, the inner tube layer is made of heat-resistant rubber, and the outer tube layer is formed of the upper and lower bag base materials. It is made of the same type of rubber as the heat-resistant rubber layer or rubber with good mutual adhesion.The tubular body formed by extrusion is divided along the axial direction, and the divided bodies are used as a protective cover to form upper and lower halves. An airbag is manufactured by bonding the outer tube layer side of a protective cover made of a divided body over two upper and lower bag base materials to the entire inner circumferential surface of the sutured portion of the two bag base materials.

In other words, the protective covers to which the upper and lower bag base materials are adhered are
Since the outer tube layer side to be adhered is made of the same type of rubber as the heat-resistant rubber layer of the upper and lower bag base materials, or rubber with good mutual adhesion, the protective cover is attached to the upper and lower bag base materials using an adhesive. Can be easily attached using vulcanization adhesive,
Furthermore, the strength can be increased.

In addition, this protective cover has a braided reinforcing layer in the middle layer, an inner tube layer made of heat-resistant rubber, and an outer tube layer made of the same kind of rubber as the heat-resistant rubber layers of the upper and lower bag base materials or mutually compatible. It is made of rubber with good adhesive properties and is formed by dividing a tubular body formed by extrusion molding along the axial direction, and the tubular body is divided into an inner layer and an outer layer made of rubber. Since it can be easily formed by extrusion molding like a three-layer reinforced rubber hose with an IJi reinforcing layer between the layers, it can be manufactured at a lower cost than silicone tape.

Furthermore, in the manufactured airbag, the protective cover covers the area where the upper and lower bag base materials are sewn together, and the protective cover completely covers the seams between the upper and lower bag base materials at the sewn site. Since it is covered, it is possible to prevent gas from leaking between the seams at this sutured site. In this case, since the protective cover includes a braided reinforcing layer, the strength of the sutured area can be made high, and it will not peel off even if it is momentarily pulled when gas is suddenly injected into the airbag. Does not occur.

Therefore, in the method for manufacturing an airbag according to the present invention, it is possible to prevent gas from leaking from the portion where the upper and lower bag base materials are sewn together, and it is also possible to reduce the number of manufacturing steps and manufacturing costs.

<Example> Hereinafter, one embodiment of the present invention will be described based on the drawings.

In addition, in the drawings, the same members as in the prior art are given the same reference numerals.

As shown in FIG. 1, the airbag 11 manufactured in the example includes two approximately circular bag base materials 2, upper and lower, as in the conventional case.
・It is formed by suturing 3 using suture thread 4 such as nylon.

These bag base materials 2 and 3 are made of a flexible woven fabric such as nylon or polyester as in the past.
As a, airbags 11 of the respective base fabrics 2a and 3a
Heat-resistant rubber layers 2b and 3b coated with heat-resistant rubber such as butyl rubber or chloroprene rubber are formed on the inner peripheral surface side.

In addition, a large opening 13 is formed in the center of the lower bag base material 3 for introducing gas from the gas generator 6 into the airbag 11, and the airbag 11 is formed around the opening 13. A plurality of mounting holes 14 are provided for mounting to the flange portion 6a of the gas generator 6 by tightening rivets or bolts, and gas is generated after the airbag 11 is inflated! I
A discharge hole 15 is provided to allow gas from the airbag 6 to escape to the outside of the airbag 11.

Furthermore, the peripheries of the opening 13, attachment hole 14, and discharge hole 15 of the lower bag base material 3 are provided with the bag base materials 2 and 3 for reinforcement.
A reinforcing cloth 16, which is similar to the above, and has a flexible base cloth 16a covered with a heat-resistant rubber layer 16b is glued or sewn.

Then, a protective force R-i7 is applied to the entire inner peripheral surface side of the sutured portion of the upper and lower bag base materials 2 and 3 to cover the sutured portion. It is used and glued.

The protective cover 17 of this embodiment, as shown in FIG.
A tubular body 18 made of a reinforced rubber hose having a braided reinforcing layer 19 between an inner tube layer 20 and an outer tube layer 21 is used.

This reinforced rubber hose 18 can be formed by extruding five inner tube layers 20, forming a braided reinforcing layer 19 around the outer circumference of the inner tube layer 20, and then extruding an outer tube layer 21, or The tube layer 20, the braided reinforcing layer 19, and the outer tube 1121 are formed by extrusion molding substantially simultaneously. Note that the inner tube layer 20 is
The outer tube layer 21 is made of heat-resistant butyl rubber or chloroprene rubber.
It is made of rubber of the same polarity as the heat-resistant rubber layers 2b and 3b of No. 3 or rubber that has good mutual adhesion. Further, the braided reinforcing layer 19 is formed by knitting reinforcing threads such as rayon threads and nylon threads in a spiral shape, braid shape, or knitting shape. The reinforced rubber hose 18 is preferably set so that its elongation is equal to the elongation of the upper and lower bag base materials 2 and 3 when it is formed into a divided body 22 to be described later.

Then, as shown in FIG. 3, the reinforced rubber hose 18 thus formed is crushed to form creases on its circumferential surface. Thereafter, as shown in FIG. 4, the reinforced rubber hose 18 is divided into two along the axial direction, and the divided bodies 22 are used as the protective cover 17. Note that after cutting the reinforcing rubber hose 18 along the axial direction, a crease is made to form the divided body 22.
may be formed.

To explain the process of manufacturing the airbag 11 of the embodiment, first, when each member is unvulcanized, the same type of rubber glue (uncured) is applied to the bonded portion of the bag base material 3 and the reinforcing cloth 16. Apply rubber sulfur dissolved in a solvent) and crimp. Thereafter, the upper and lower bag base materials 2 and 3 and the protective cover 17 are similarly pressed together in a predetermined shape.

Thereafter, a masking agent to prevent adhesion is applied to a predetermined area inside the bag, and the required temperature and time are applied to vulcanize and vulcanize the bag.

Then, the peripheral edges of the bag base materials 2 and 3 are sewn together with a suture thread 4 to manufacture the bag.

As another example, when each member is vulcanized, first, the peripheral edges of the upper and lower bag base materials 2 and 3 formed into a predetermined shape are sewn together using the suture thread 4. Note that the reinforcing cloth 16 is fixed to the lower bag base material 3 at a predetermined position in advance. Incidentally, the reinforcing cloth 16 may be fixed in the last step of the manufacturing process of the airbag 11.

Then, turn the front and back sides so that the seam allowance 12 side is inside, and then turn the upper and lower bag base materials 2 and 3 at the sewing site of the upper and lower bag base materials 2 and 3.
The outer tube layer 21 side of the protective cover 17 is manufactured by applying an ordinary rubber adhesive over three parts to adhere the outer tube layer 21 side of the protective cover 17.

Then, the airbag 11 is attached to the gas generator 6, folded, and mounted on a vehicle for use.

Therefore, in the manufacturing method of the embodiment, the protective cover 17, which is adhered to the upper and lower bag base materials by vulcanization or an ordinary rubber adhesive, has the outer tube layer 21 side to be adhered to the upper and lower bag base materials 2 and 3. Since the heat-resistant rubber layers 2b and 3b are made of the same type of rubber or rubber that has good mutual adhesion, the protective cover 17 can be attached to the upper and lower bag base materials 2 and 3 using vulcanization adhesive or rubber adhesive. can be easily and firmly bonded.

Further, this protective cover 17 is attached to the intermediate layer and has a reinforcing layer 19.
The inner tube layer 20 is made of heat-resistant rubber, and the outer tube layer 21 is made of the same kind of rubber as the heat-resistant rubber layers 2b and 3b of the upper and lower bag base materials 2 and 3. The reinforced rubber hose 18 is formed by dividing it along the axial direction, and the three-layer reinforced rubber hose 18 can be easily formed by extrusion molding, making it cheaper to manufacture than silicone tape. can do.

Furthermore, in the manufactured airbag 11, the protective cover 1
7 covers the part where the upper and lower bag base materials 17 are sewn together, across the upper and lower bag base materials 2 and 3, and the area between the seams of the upper and lower bag base materials 2 and 3 at the sutured part is completely covered by the protective cover 17. This prevents gas from escaping between the seams at this sutured site. In this case, since the protective cover j includes the binding reinforcing layer 19,
When gas from the gas generator 6 is suddenly injected into the airbag 11, no peeling occurs even if it is momentarily pulled.

In addition, in the embodiment, the reinforced rubber hose 18 is divided into two parts,
Although the case where two divided bodies 22 are formed has been described, the divided body 22 which becomes the protective cover 17 may be obtained by dividing the reinforcing hose 18 into three or more parts.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view showing an inflated state of an airbag manufactured according to an embodiment of the present invention, FIG. FIG. 4 is a cross-sectional view of a divided body used in manufacturing the same example. FIG. 5 is a cross-sectional view of a conventional airbag. . 2... Upper bag base material, 2b... Heat resistant rubber layer, 3... Lower bag base material, 3b... Heat resistant rubber layer, 11... Air bag, 17... Protective cover. 18... (Tubular body) Reinforced rubber hose, 19... Braided reinforcement layer, 20... Inner tube layer, 21... Outer tube layer, 22... Divided body. Patent application Toyoda Gosei Co., Ltd. ~N1111~ Figure

Claims (1)

[Claims] The peripheral edges of two upper and lower bag base materials each having a heat-resistant rubber layer on the inner surface of their opposing surfaces are sewn together to form a bag shape, and the entire circumference of the inner circumferential surface of the sewn portion is sewn together. A method for manufacturing an airbag in which a protective cover is bonded to cover the airbag, the protective cover having a braided reinforcing layer as an intermediate layer, an inner tube layer made of heat-resistant rubber, and an outer tube layer formed of heat-resistant rubber. After forming by extrusion a tubular body whose layers are made of the same type of rubber as the heat-resistant rubber layers of the upper and lower bag base materials or rubber with good mutual adhesion, the tubular body is divided along the axial direction. The air bag is manufactured by adhering the outer tube layer side of the divided body to the entire circumference of the inner circumferential surface side of the sutured portion across the two upper and lower bag base materials. How to make bags.