JPH0958387A - Air bag for vehicle and manufacture thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To integrate a protection cloth which protects seams of a reinforcing cloth which is sewn and attached on a basic cloth with the basic cloth or the reinforcing cloth without sewing or bonding the protection cloth. SOLUTION: After a plural number of reinforcing cloths 5 are sewn and attached on a basic cloth 1a, a protection cloth 8 is overlapped on a surface of the reinforcing cloth 5 by covering annular seams which appear on the surface of the reinforcing cloth 5, and then an inflator insertion hole and a mounting hole 13 of an inflator are opened in a predetermined region of accumulated layers of each cloth by using a laser beam cutting machine 17. Each cloth is fused and cut by high temperature heat of laser beam and the inflator insertion hole and the mounting hole 13 are fused and integrated at their opening ends so that the protection cloth 8 is not separated from the reinforcing cloth 5 or the basic cloth 1a.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle airbag which is mounted on a vehicle to ensure the safety of passengers when a collision accident occurs.

[0002]

2. Description of the Related Art An air bag for a vehicle comprises a combination of a bag and an inflator, the bag is folded, and the one for the driver's seat is incorporated in a stearin foil. The inflator is a gas generator, which operates by receiving an electric signal generated by detecting a shock due to a collision accident, instantaneously ejecting gas and blowing it into a bag to inflate and expand the bag. . The gas emitted from the inflator has high temperature and high pressure,
The bag must naturally withstand the high temperatures and pressures of the gas. The bag usually has two disc-shaped base fabrics sewn on its periphery, and the inflator is inserted into a hole (inflator insertion hole) opened in the center of one of the base fabrics and fixed to the opening edge thereof. It As the base cloth, for example, a woven cloth coated with silicone rubber is used.

The base fabric used for the bag is required to have heat resistance and compressive strength at the time of expansion and deployment, and to withstand the impact force of gas pressure explosively generated. In particular, since a strong force momentarily acts on the base cloth of the mounting portion of the inflator, it is necessary to have strength to withstand this strong force. For this reason, two or more reinforcing cloths are sewn to the base cloth of the mounting portion of the inflator, the laminated base cloth and the reinforcing cloth are sandwiched between the flange of the inflator and the retainer, and both are tightened with tightening bolts.

However, when the sewing thread for sewing the base cloth and the reinforcing cloth is exposed to the high temperature of gas in the bag, the sewing thread is melted or burned by the explosive powder, and the reinforcing cloth is partially separated from the base cloth. This part becomes the starting point and cracks occur in the base cloth,
A dangerous situation occurs in which the bag cannot be expanded and deployed properly at the time of a collision.

[0005]

As the simplest method of protecting the sewing thread exposed on the outer surface of the base cloth or the reinforcing cloth, there is known a method of sealing the sewing thread exposed on the outer surface of the reinforcing cloth or the base cloth with a silicone resin. Has been. However, this method is troublesome in coating the silicone resin, requires a long time for the subsequent drying process, and is poor in work efficiency. In order to solve this problem, an attempt has been made to sew a reinforcing cloth around the opening of the base cloth of the bag and dispose a protective sheet on the inner surface of the bag so as to cover the sewn portion of the reinforcing cloth. It is introduced in Kaihei 2-71053. In this method, the exposed surface of the sewing thread for sewing the reinforcing cloth is covered with a protective sheet so that the exposed surface of the sewing thread does not come into direct contact with the high temperature of the gas pressed into the bag. According to this method, the high temperature gas that has been ejected is not blocked by the protective sheet and directly hits the sewing thread of the reinforcing cloth,
It is possible to effectively prevent gas leakage due to melting and burning of the sewing thread.

According to this method, as shown in FIG.
After the reinforcing cloth 22 is sewn on the protective cloth 23, the protective cloth 23 is overlapped and the inflator insertion hole 24 and the mounting hole 25 formed in the reinforcing cloth 22 and the protective cloth 23 are positioned to fix the inflator flange 26 and the retainer 27. Insert the bolts 28 into the mounting holes 25 and insert the nuts 2
Tighten 9 and crimp rivets to the other mounting holes,
Tighten the retainer 27 to the flange 26, but
The work is extremely troublesome because the registration of the protective cloth 23 with the protective cloth 23 is performed inside the bag.

However, in this prior art example, the protective cloth 23
Is a reinforcement cloth 22 or a base cloth 2 by sewing or adhesive.
Although it may be attached to No. 1, it is substantially the same as the addition of the reinforcing cloth 22 when sewn, and it is substantially the same as the previous sealing process when gluing. Yes, extra man-hours are required to attach the protective cloth.

An example of the concept of sewing a reinforcing cloth and a protective cloth together is disclosed in Japanese Utility Model Laid-Open No. 5-67560. In this example, as shown in FIG. 8, a heat resistant sheet is used as the protective cloth 31, and the heat resistant sheet is used as a base material between the inflator 32 and the retainer 33 at the peripheral edge of the opening of the bag or the reinforcing cloth 34 at the inside thereof. It is sewn on the cloth 35.

In this example, since the sewn portion of the protective cloth 31 is covered with the retainer 33, the sewn portion is not directly exposed to the high temperature gas, but the sewn portion is in the immediate vicinity of the inflator 32 and when the inflator 32 is heated. In the summer, the amount of heat generated by the inflator 32 becomes high, and even if the sewn portion of the protective cloth 31 is covered by the retainer 33, the temperature becomes high. There is a high risk that the sewing thread in the sewn portion directly contacting the retainer 33 will melt.

An object of the present invention is to provide a vehicle air bag in which a protective sheet is attached to a base fabric of a bag to which a reinforcing cloth is sewn to cover a sewn portion of the reinforcing cloth, and a manufacturing method thereof. To provide a method.

[0011]

In order to achieve the above object, a vehicle airbag according to the present invention is a vehicle airbag having a base cloth, a reinforcing cloth, and a protective cloth. , The bag is a bag for the airbag, the bag is folded, and the reinforcing cloth increases the strength of the opening edge of the inflator insertion hole opened in the airbag and is laminated on the base cloth and sewn. The protective cloth is laminated on the base cloth or the reinforcing cloth and covers the surface of the sewn area between the base cloth and the reinforcing cloth to protect the sewn area from the high temperature generated in the bag when the airbag is inflated and deployed. The base cloth, the reinforcing cloth, and the protective cloth are welded and integrated at the opening edge of the inflator insertion hole that is opened commonly to at least three parties.

The base cloth, the reinforcing cloth, and the protective cloth have mounting holes. The mounting holes are opened around the opening edge of the inflator insertion hole, and bolts or rivets for mounting the inflator in the bag are inserted. The base cloth, the reinforcing cloth, and the protective cloth are welded and integrated at the opening edge of the mounting hole.

The base cloth, the reinforcing cloth and the protective cloth are woven cloth coated with rubber or synthetic resin,
The protective cloth is positioned with the coated surface facing the inner surface of the bag.

The method for manufacturing an airbag for a vehicle according to the present invention is a method for manufacturing an airbag for a vehicle, which has a sewing process and a welding process, and the sewing process is a bag of the airbag. The reinforcing cloth is laid on the base cloth, and the base cloth and the reinforcing cloth are sewn together at the outer peripheral position of the region where the inflator insertion hole is to be opened. The welding processing is performed by sewing the base cloth and the reinforcing cloth. A protective cloth is applied to the surface of the base cloth or the reinforcing cloth to cover the part, and the region where the inflator insertion hole should be opened is melted to open the inflator insertion hole. Is a process for welding and unifying at the opening edge.

In addition, the welding process is a process in which a mounting hole for mounting the inflator is opened along with the opening of the inflator insertion hole, and the base cloth, the reinforcing cloth and the protective cloth are integrally welded at the opening edge. It includes.

The base cloth, the reinforcing cloth and the protective cloth have a common positioning small hole, and the base cloth and the reinforcing cloth are laminated and sewn by using the positioning small hole. , The protective cloth is
Based on the small holes for positioning, they are laminated on the surface of the reinforcing cloth or the surface of the base cloth, and the welding process is a process of opening a common inflator insertion hole in the base cloth, the reinforcing cloth, and the protective cloth, A small hole for positioning each cloth is included in the area where the inflator insertion hole is formed.

On the base fabric of the airbag bag, one or more reinforcing fabrics are superposed by regulating the relative positions with reference to the positioning small holes formed in the fabric surface, and the two are sewn together with annular stitches in multiple layers. Then, the protective cloth is superposed on the cloth by regulating the relative positions with respect to the small holes on the cloth surface, and the inflator insertion hole and the mounting hole common to the stacking of the cloths are opened and the opening edges are welded at the same time. As a result, the protective cloth is integrated with the base cloth, and the assembly to the inflator is facilitated.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described below with reference to the drawings. In FIG. 1, a vehicle airbag according to the present invention is
A pair of disc-shaped base cloths 1a, 1b are sewn on the outer peripheral edges thereof to form a bag 2, and the bag is made to face the inside of an inflator insertion hole 3 opened at the center of the cloth surface of one of the base cloths 1a. It is installed.

Base cloth 1a at the opening edge of the inflator insertion hole 3
2, a stack of a plurality of reinforcing cloths 5 is sewn on the inner surface of the bag 2 with annular seams 6 in a concentric circular fashion, as shown in FIG. Is a bag 2
Is sewn with the same thread as the thread for sewing the laminated layers of the reinforcing cloth 5 with the strap 7 for restricting the expansion and expansion shape of the. In this embodiment, the reinforcing cloth 5 is laminated on the bag 2
In this example, the protective cloth 8 is laminated and sewn on the inner surface of the sheet, and the protective cloth 8 is further laminated on the surface of the reinforcing cloth 5 which is the outermost layer. As shown in FIG. 1, the flange 9 of the inflator 4 is applied to the outer surface of the bag 2, the inflator 4 is inserted into the inflator insertion hole 3, and the retainer 10 is used to protect the bag 5 inside the bag 2.
Of the bolt 11 inserted into a part of the mounting hole from the retainer 10 through the base cloth 1a, the reinforcing cloth 5 and the protective cloth 8, and the nut 12 is tightened to the flange 9.
A rivet is inserted into the other mounting hole and caulked. In the present invention, the opening edges of the inflator insertion hole 3 opened in common to the base cloth 1a, the reinforcing cloth 5 and the protective cloth 8 and the mounting hole 13 formed around the inflator insertion hole 3 are fused and integrated with each other. is there.

That is, the protective cloth 8 is formed by laminating the reinforcing cloth 5 laminated and sewn on the base cloth 1a and the inflator insertion hole 3
And integrated at the opening edge of the mounting hole 13,
After that, when the outer edges of the pair of base fabrics 1a and 1b are sewn to be processed into the bag 2, or when the inside and outside of the bag 2 are reversed and the inflator 4 is further assembled, the protective fabric 8 is separated from the base fabric 1a. If the high-pressure gas is blown into the bag after the bag 2 has been folded and equipped in the vehicle, the sewing thread of the reinforcing cloth 5 is completely covered with the protective cloth 8. , The attachment hole 13 which is not directly exposed to the high temperature of the gas, and which is opened in the inflator insertion hole 3 and its surroundings even if a strong tensile force acts on the base cloth 1a when the bag 2 is inflated and deployed. Since the protective cloth 8 is fixed at the opening edge, the position of the protective cloth 8 does not shift.

Next, a method for manufacturing a vehicle airbag according to the present invention will be described. FIG. 3 shows the main components used in the manufacture of the vehicle airbag of the present invention.

The base cloth 1a, the reinforcing cloth 5 and the protective cloth 8 are woven cloths composed of heat-fusible synthetic fibers and coated with rubber or synthetic resin having heat resistance as a bag of an air bag. It may be a woven fabric composed of a heat-melting synthetic resin that can withstand the heat generated by the inflator. The material of the base cloth 1a is required to be airtight and flexible, but the reinforcing cloth 5 and the protective cloth 8 can be made of the same material as the base cloth 1a.

The base cloth 1a is a disk-shaped cloth having a required diameter according to the capacity of the bag, and the reinforcing cloth 5 has a large diameter due to the opening area of the inflator insertion hole 3 opening in the center of the base cloth 1a. The protective cloth 8 is in the shape of a circle, and has a size that covers at least the seam of the reinforcing cloth 5. In each case, there are two positioning small holes 14 within the opening area of the inflator insertion hole 3.
Individually opened.

FIG. 4 shows a table 15a for sewing a bag of a vehicle airbag. Two pins 16a that fit into the small holes 14 of each cloth are planted on the table 15a.

First, the base cloth 1a is loaded onto the table 15a with the coating surface facing upward, two pins 16a are fitted into the small holes 14, and then the positions of the small holes 14 of the reinforcing cloth 5 are aligned. As shown in FIG. 5, the inflator insertion hole 3 is laminated with a sewing machine for laminating the cloths which are laminated and the pins 16a are inserted into the respective small holes 14 and positioned.
The circumference of the opening area is sewn concentrically with the circular stitch 6 in multiple layers. Of course, the reinforcing cloth 5 may be laid down and the base cloth 1a may be laid on it and sewn.

In FIG. 6, the base cloth 1a to which the reinforcing cloth 5 is sewn next is transferred onto the processing table 15b of the cutting machine, and the surface of the reinforcing cloth 5 faces upward, and the small holes 14 common to the stacking of the cloths are provided. After inserting the pin 16b into the inside, carrying in the protective cloth 8 on the reinforcing cloth 5 of the uppermost layer, inserting the small hole 14 of the protective cloth 8 into the pin 16b, and aligning it, a melt cutter, for example, laser beam cutting A machine 17 is used to cut the laminated layers of the cloths, the inflator insertion hole 3 is opened in the inflator insertion hole forming region A in the outer shape of the inflator, for example, a circular shape, and the inner and outer sewing is performed around the inflator insertion hole 3. Area B between parts
The mounting hole 13 for mounting the inflator is opened. Alternatively, the protective cloth 8 may be opened as a lowermost layer and then aligned. In the laminated layers of the cloths, the edges of the holes are fused by high heat generated by the irradiation of the laser beam, and the inner edges of the holes, which are the fusing points, are melted and integrated with each other under the influence of high temperature.

An example in which a laser beam cutter is used for fusing each layer has been described above, but the point is that each insertion hole can be opened by heating the laminate of each fabric and fusing it. If it is, it is not limited to laser beam processing, ultrasonic processing can be used, and a pressing machine having a cutting blade die heated to a high temperature can also be used. If necessary, a vent hole is opened in the base cloth 1a to which the protective cloth 8 and the reinforcing cloth 5 are attached, and the other base cloth 1b is formed.
Then, the bag is sewn to be processed into a bag shape, the bag is turned inside out, and the inflator 4 is assembled to be assembled into the vehicle airbag shown in FIG. In addition, the opening of the vent hole can be similarly cut.

In the above, the example in which the protective cloth 8 is attached to the surface of the reinforcing cloth 5 sewn to the base cloth 1a has been described, but the reinforcing cloth 5 should be attached to the outer surface of the bag 2 of the airbag. In some cases, the bag may be attached to the inside and outside of the bag separately. In either case, the mounting surface side of the protective cloth 8 is the inner surface side of the airbag bag 2. Regardless of whether the protective cloth 8 is attached to the base cloth or the reinforcing cloth, it is integrated with the base cloth 1a and therefore does not fall off when the bag is inverted.

[0029]

EXAMPLES Examples of the present invention will be shown below.

(Example 1) Three reinforcing cloths (diameter 20 cm) were superposed on a base cloth (diameter 65 cm) and radii 11 cm and 14 c.
M and 18 cm were concentrically sewn in multiple layers with annular seams, and then the entire surface of the reinforcing cloth was covered with a protective cloth (diameter 20 cm). The base cloth, the reinforcing cloth, and the protective cloth were made of the same material, that is, silicon-coated cloth.

Next, a CO ₂ laser cutter (output 50
W) was used to open an inflator insertion hole and an attachment hole in the laminate of each cloth at a speed of 40 m / sec. The inflator insertion hole has a diameter of 10 cm, and the mounting holes are 5.5 mm at a predetermined position from the opening center of the inflator insertion hole, and the number of mounting holes is 6.5.
A total of 12 holes of 4 mm were opened. The time required to open all the holes was 20 seconds. In the obtained bag, the cloths at the opening edges of the inflator insertion hole and the mounting hole were welded to each other, the protective cloth was integrated with the base cloth, and the protective cloth was not peeled off even when pulled by hand. Furthermore, as a result of the burst test, the protective cloth did not scatter.

Next, after heating an actual vehicle air bag in which an inflator was assembled in this bag for 4 hours in an oven at 80 ° C., it was taken out to the outside, 1 minute later, the powder was ignited and the bag was inflated, Deployed. After that, when the bag was removed from the inflator and the sewn part of the reinforcing cloth was checked, no abnormality was found.

(Comparative Example 1) As a comparative example, four reinforcing cloths were used, and each reinforcing cloth was sewn to a base cloth with an outermost ring stitch and an intermediate ring stitch, and an innermost ring stitch was formed. The mesh is sewn to the base fabric with only one reinforcing cloth in contact with the base fabric, two annular stitches appear on the outer surface, the bag is assembled to the inflator, and the bag is inflated and expanded in the same manner as in Example 1. As a result, it was confirmed that the sewing thread appearing on the outer surface of the reinforcing cloth was melted at several places.

(Example 2) For the base cloth, the reinforcing cloth and the protective cloth,
Using nylon 66 4200 55 × 55 non-coated cloth, a reinforcing cloth is sewn onto a base cloth in the same manner as in Example 1, a protective cloth is laid on the sewn cloth, and a blade having a fusing blade is used to form a blade shape. Was heated to 300 ° C. to open the inflator insertion hole and the mounting hole.

An inflator was attached to the obtained bag and an expansion and deployment test of the airbag was conducted in the same manner as in Example 1. As a result, a slight trace of melting was observed on the non-coated cloth surface of the protective cloth directly exposed to high temperature. However, no abnormality was found in the sewing thread for sewing the reinforcing cloth to the base cloth.

[0036]

As described above, according to the present invention, after reinforcing cloth is sewn to the base cloth, the protective cloth is laminated on the laminated surface,
By fusing the cloth surface of each layer to open the inflator insertion hole and the mounting hole, the protective cloth can cover the seams of the reinforcing cloth and can be integrated with the reinforcing cloth or the base cloth. No work such as positioning of the protective cloth with respect to the base cloth is required at the time of assembling to the inflator, and it has an effect that the assembling work of the airbag can be easily performed.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a vehicle airbag according to the present invention.

FIG. 2 is a front view showing a main part of a bag of a vehicle airbag according to the present invention.

FIG. 3 is a diagram showing components used in the production of the present invention.

FIG. 4 is a view showing a table for processing a bag of a vehicle airbag.

FIG. 5 is a diagram showing a state in which a reinforcing cloth is sewn onto a base cloth.

FIG. 6 is a diagram showing a fusing process by a laser beam cutter.

FIG. 7 is a diagram showing an example of a conventional example for protecting the seams of the reinforcing cloth.

FIG. 8 is a diagram showing another example of the conventional example for protecting the seams of the reinforcing cloth.

[Explanation of symbols]

 1a, 1b Base cloth 2 Bags 3 Inflator insertion hole 4 Inflator 5 Reinforcement cloth 6 Ring stitch 7 Strap 8 Protective cloth 9 Flange 10 Retainer 11 Bolt 12 Nut 13 Mounting hole 14 Small hole 15a, 15b Table 16a, 16b Pin 17 Laser beam Cutting machine

Claims (6)

[Claims] 1. A vehicle airbag having a base cloth, a reinforcing cloth, and a protective cloth, wherein the base cloth is a bag for the airbag, the bag is folded, and the reinforcing cloth is This is to increase the strength of the opening edge of the inflator insertion hole opened in the airbag, and is laminated and sewn on the base cloth, the protective cloth is laminated on the base cloth or the reinforcing cloth, and the base cloth and the reinforcing cloth are laminated. It covers the surface of the sewn portion with and protects the sewn portion from the high temperature generated in the bag when the airbag is inflated and deployed. The base cloth, the reinforcing cloth, and the protective cloth are at least three parties. An airbag for a vehicle, characterized in that it is welded and integrated at an opening edge of an inflator insertion hole opened in common. 2. The base cloth, the reinforcing cloth, and the protective cloth each have a mounting hole, and the mounting hole is opened around an opening edge of the inflator insertion hole, and a bolt or a rivet for mounting the inflator in the bag is inserted. The vehicle airbag according to claim 1, wherein the base cloth, the reinforcing cloth, and the protective cloth are welded and integrated at the opening edge of the mounting hole. 3. The base cloth, the reinforcing cloth, and the protective cloth are woven cloth coated with rubber or synthetic resin, and the protective cloth is positioned with its coated surface facing the inner surface of the bag. The airbag for a vehicle according to claim 1 or 2, characterized in that. 4. A method of manufacturing an airbag for a vehicle, which comprises a sewing process and a welding process, wherein the sewing process comprises stacking a base cloth and a reinforcing cloth, which are bags for the airbag, and forming an inflator insertion hole. The base cloth and the reinforcing cloth are sewn together at the outer peripheral position of the area to be opened, and the welding processing covers the portion where the base cloth and the reinforcing cloth are sewn together to protect the surface of the base cloth or the reinforcing cloth. This is a process in which the cloth is applied, the region where the inflator insertion hole is to be opened is melted and the inflator insertion hole is opened, and the base cloth, the reinforcing cloth, and the protective cloth are welded together at their opening edges. A method of manufacturing an airbag for a vehicle, which is characterized by the above. 5. The welding process is a process of opening a mounting hole for mounting an inflator along with an opening of an inflator insertion hole, and integrally welding a base cloth, a reinforcing cloth, and a protective cloth at an opening edge thereof. The method of manufacturing an airbag for a vehicle according to claim 4, wherein the method includes: 6. A base cloth, a reinforcing cloth, and a protective cloth have a common positioning small hole, and the base cloth and the reinforcing cloth are laminated and sewn using the positioning small hole. The protective cloth is laminated on the surface of the reinforcing cloth or the surface of the base cloth with reference to the small holes for positioning, and the welding process is performed by using the common inflator insertion hole for the base cloth, the reinforcing cloth and the protective cloth. The method for manufacturing an airbag for a vehicle according to claim 4, wherein the positioning small hole of each cloth is included in a region where the inflator insertion hole is formed.