JPH03208746A - Air bag - Google Patents

Abstract

PURPOSE:To secure required mechanical characteristics and also improve softness and housability at an air bag formed out of cloth whose coating is of heat resisting resin, by providing partially the part of resin coating. CONSTITUTION:An air bag is formed of cloth whose coating is of heat resisting resin. In this instance, the part of resin coating is partially provided. For example, it is provided at an inflater fitting portion 2, the opposing portion against the portion 2 and a sewing up margin portion 1. Also, the air bag is formed of a bag body fabric. Thus, by applying resin coating only to the required parts of the air bag, the required mechanical characteristics of the air bag are maintained, and at the same time the softness and housability of the air bag is improved.

Description

[Detailed description of the invention] [Industry. FIELD OF THE INVENTION The present invention relates to an improvement in an airbag that is inflated in the event of a collision of a vehicle, such as an automobile, to absorb the impact and protect a seated occupant.

[Background Art] In recent years, the need for airbags to ensure the safety of vehicle occupants has rapidly increased. This airbag is
When a car crashes, a sensor receives the shock of the collision and generates high-pressure gas, which instantly inflates the airbag and prevents the occupants from moving in the event of a collision, ensuring safety. .

Conventional airbags are made by coating one side of a plain fabric or bag fabric using nylon 6.6 filament threads of 400 to 1000 denier with synthetic rubber such as chloroprene, chlorosulfonated olefin, or natural rubber. things were being used.

In an airbag constructed using such a single-sided, fully coated fabric, the base fabric is required to have high strength (impact resistance) that can withstand instantaneous expansion by high-pressure gas generated by an inflator (high-pressure gas generator). In order to be
A certain degree of thickness is required, and usually about 50 to 200 g/m is coated on one entire surface.

[Problems to be Solved by the Invention] However, such coated fabrics have thick rubber and are hard, making it difficult to store them in narrow spaces such as steering wheels and instrument panels. When inflated, the impact on the human body, especially the face, is strong, and the repulsive force may cause the face to collide with vehicle structures, resulting in injury.

In view of the drawbacks of conventional airbags, the present invention provides an airbag that maintains the necessary mechanical properties of an airbag, causes less impact on the human body when the airbag is inflated, is flexible, and has excellent storage properties. That is.

[Means for Solving the Problems] The present invention has the following configuration to achieve the above object.

That is, the airbag of the present invention is constructed of a fabric coated with a heat-resistant resin, and is characterized in that the resin coating portion is only partially formed.

[Function] Airbags are designed to protect and ensure the safety of seated occupants by generating high-pressure gas using an inflator in the event of a vehicle collision. The gas hits one side of the inflator and then expands to other parts, but in that case, the highest temperature and pressure are applied to the part that is first hit by the gas.

The present invention analyzes the spread of gas and provides a product that maintains sufficient mechanical properties, has low impact, is flexible, and has excellent storage capacity by coating only specific parts with resin. We have determined that it is possible to do so.

The fabric in the present invention includes nylon 6, nylon 6
・Aramid fibers represented by polyamides such as 6, nylon 12 and nylon 4 and 6, copolymers with polyphenylene terephthalamide and aromatic ethers, polyester fibers represented by polyalkylene terephthalates,
Continuous fibers such as rayon fibers, ultra-high molecular weight polyethylene fibers, sulfone fibers such as paraphenylene sulfone and polysulfone, synthetic fibers such as polyetherketone fibers, and inorganic fibers such as carbon fibers, glass fibers and metal fibers are used. Woven, knitted or non-woven fabrics can be used.

Such continuous fibers may contain various additives that are commonly used to improve productivity or properties in the manufacturing process or processing process of the raw yarn.

For example, heat stabilizers, antioxidants, light stabilizers, smoothing agents,
Antistatic agents, plasticizers, thickeners, pigments, flame retardants, gloss-imparting agents, and the like can be included.

In addition, as the heat-resistant resin in the present invention, for example, heat-resistant synthetic resins (elastomers) such as chloroprene, chlorosulfonated olefin, fluorine rubber, vinyl chloride, and chlorinated olefin, and natural rubber can be used. However, synthetic resins containing ordinary organic or inorganic flame retardants such as phosphorus flame retardants or halogen flame retardants, such as urethane resins, acrylic resins, and melamine resins, can also be used.

A method for manufacturing an airbag according to the present invention will be explained with reference to the drawings.

First, an example in which an airbag is formed by sewing two pieces of cloth will be described with reference to FIGS. 1 and 2.

FIG. 1 shows the fabric on the side where the inflator attachment portion is located, and the coating portion is partially applied around the inflator attachment portion.

In this example, the coated part (shaded part) and the non-coated part (margin part) are arranged concentrically, but the shape of the coated part may be an ellipse, a rectangle, or a star shape, and is not limited to the shape.

As shown in the figure, for example, it is preferable to apply a resin coating to the seam allowance, since this achieves the effect of sealing the sewing thread and further improves the breaking strength of the airbag. A similar effect can be achieved by applying a resin coating to the joints of an airbag made of bag fabric.

FIG. 2 shows the fabric on the opposite side of the inflator (the side facing the person), and the portion facing the inflator is coated with resin. The coating resin in this part has the effect of protecting the human body (face) from the high temperature and high pressure gas leaking from the weave, and there are no restrictions on the size of the coating area as long as it can sufficiently achieve this effect. do not have.

After the two pieces of fabric shown in Figures 1 and 2 have been coated, the outside of the seam allowance is cut out, the coated part is turned inside, and the seam allowance shown in Figure 1 and the seam shown in Figure 2 are sewn together. The airbag is shaped by overlapping the margins and sewing the margins.

An airbag manufactured by such a method can sufficiently withstand the temperature and pressure during inflation by high-pressure gas.

The key point of the airbag of the present invention is that no coating is applied to areas that are less affected by temperature and pressure.

That is, the non-coated portion of the airbag has the function of absorbing the impact when the airbag is inflated and softening it.
Moreover, the flexibility of the non-coated portion achieves excellent storage properties.

Next, an example in which the airbag of the present invention is produced using a bag fabric as the fabric will be explained with reference to FIGS. 3 to 5.

FIG. 3 is a longitudinal sectional view of the airbag, FIG. 4 is a plan view as seen from the inflator attachment side, and FIG. 5 is a lateral sectional view of the airbag.

In this example, as shown in FIG. 3, the front and back sides of the bag fabric have a long interval A1 in the longitudinal direction of the fabric (that is, the warp direction), a short interval B, C, C, B, A, B, CXB. ,AXB,C
It is woven in a manner that is periodically reversed like XB, A, B,
And, as shown in Fig. 5, short intervals C', B/, long intervals A', short intervals B', in the width direction (that is, weft direction),
A fabric woven with the front and back sides reversed as shown in C' is shown; A structure without a pouch shown in can be used.

In the figure, the shaded area indicates the resin-coated area, and the blank area indicates the non-coated area.

Note that the shape of the bag fabric is not limited to a rectangular shape as in this example, but may be any shape such as a circle or an ellipse.

Among various types of bag fabrics, those having the structure shown in the figure, in which the front and back sides are reversed at the boundary and have a child bag part at the peripheral edge, are preferable because they have excellent shock absorption properties.

The methods of partially coating the present invention include screen print coating, reverse coating by engraving the roll surface, knife coating after covering the non-coated surface with a film, roll coating, and partial coating using pressurized gas to coat the coating resin liquid. An appropriate method can be used, such as spraying.

There are no particular restrictions on the thickness of the coating resin9, but as long as it is durable against high temperature and high pressure gas, the thinner it is, the less impact there will be on the human body when the airbag is inflated, and the easier it will be to store it. It is also preferable in terms of.

In general, the amount (thickness) of coating resin is preferably 2
0 to 150 g/n {especially preferably 30 to 100 g
/yr? It is.

The area of the coating part should be selected appropriately depending on the type of inflator, but preferably the area of the inflator mounting part is 10 to 25 cm smaller than the inflator mounting part.
It is about m wide.

The coating area on one side of the inflator has a diameter of 20~
A range of 60 cm is preferred.

On the other hand, the coating area of the seam allowance is preferably 2 to 5 cm wide.

After such a coating is applied, the resin is heated to form a film, but the conditions at this time may vary depending on the type of resin used, such as reaction (polymerization) and curing, depending on the processing purpose. can.

[Example] 10 Next, the present invention will be explained in more detail with reference to Examples.

Example 1, Comparative Example 1 Using nylon 6.6 fibers with a total fineness of 840 denier, 162 filaments, and a strength of 8.6 g/denier,
A plain woven fabric with a density of 15 yarns/inch for each warp and weft was prepared, scoured and dry set in the usual manner, and then woven with a viscosity of 8.
Using a flat screen printing machine, partial coating as shown in FIGS. 1 and 2 was applied using chloroprene rubber of 000 cps.

The coating amount at this time was 100 g/m, and in accordance with Figure 1, the radius was 2.5 cm around the inflator mounting part.
The range surrounded by a radius of 13 cm from m, and a radius of 33 c
A region surrounded by a radius of 37 cm from m was partially coated.

On the other hand, as corresponding to Fig. 2, the area surrounded by a radius of 20 cm from the center of one facing part of the inflator and the radius of 33 cm
The area surrounded by a radius of 37 ca was partially coated.

Next, a hole with a radius of 4 cm was drilled in the center corresponding to Figure 1 as the inflator mounting part. After that, cut out the outside of the seam allowance of the partial coat cloth corresponding to Figures 1 and 11 and Figure 2, turn the coat part inside, and sew the center of the seam allowance so that the weight of the 35cm radius is 190g An airbag was created.

As Comparative Example 1, chloroprene rubber with a viscosity of 8,000 cps was coated with a knife to produce a coated cloth with a coating amount of 100 g/bo, and after cutting, the coated portion was turned inside, and a hole with a radius of 4 cm was drilled as an inflator mounting portion. After that, it was sewn to create an airbag with a radius of 35cm and a weight of 260g.

Next, as a test of the impact on the human body due to airbag inflation, as shown in Figure 6, an ultra-thin rubber balloon was placed inside the airbag, and air was filled to create an internal pressure of 0.2 kg/cd. A 500 g lead pendulum (swing radius: 100 cm) was released from a 45 degree angle, collided with the airbag, and the angle at which the pendulum returned due to the repulsion was measured.

The storability was measured by folding the sewn airbag so that the width was divided into three equal parts, and then folding it at right angles to the folding line so that the width was divided into three equal parts. A relative value was determined when Comparative Example 1 was set as 100. These evaluation results are shown in Table 1.

In Table 1, compared to Comparative Example 1, the impact on the human body when the airbag was inflated was smaller, and the storage capacity was also excellent.

Example 2, Comparative Examples 2 and 3 Using nylon 6.6 fibers with a total fineness of 840 denier, 162 filaments, and a strength of 8.8 g/denier,
It is woven using a rapier loom with a jacquard at a warp thread density of 24 threads/inch and a weft thread density of 24 threads/inch on each of the front and back sides, and the innermost dimension is a circular bag weave with a diameter of 69 cm. A circular bag weave was formed with a width of 2CII1, and the outermost layer had a structure in which the front and back sides were reversed again.

19 Next, after scouring, drying, and setting in a conventional manner, a partial coating as shown in FIG. 1 was applied using a flat screen printing machine with chloroprene rubber having a viscosity of 8000 cps. The amount of coating at this time was 98g/Po, and the coating area was 22cm in radius around the inflator mounting area.
The area of 0c+n was coated. The other part of the bag body facing the inflator has a radius of 20 cm from the center.
The n+ part was coated.

On the other hand, as Comparative Example 2, chloroprene rubber with a viscosity of 8000 cps was knife-coated on both sides of the bag fabric,
A coating with a coating amount of 98 g/rd on one side was obtained.

In both Example 2 and Comparative Example 2, a hole with a radius of 4 cm was drilled as an inflator mounting portion.

Next, in the same manner as in Example 1, the impact resistance to the human body due to airbag inflation and the storability were measured.

The storability was expressed as a relative value when Comparative Example 2 was taken as 100.

These evaluation results are shown in Table 2.

1 A Table 2 As is clear from Table 2, compared to Comparative Example 2, the airbag of the present invention had a smaller impact on the human body when the airbag was inflated, and had excellent storage properties.

[Effects of the Invention] According to the present invention, the impact on the human body due to airbag inflation can be reduced, and the airbag has a low risk of injury due to collision with vehicle structures due to rebound caused by airbag inflation. can get. At the same time, its excellent storage properties make it possible to downsize the steering wheel and instrument panel, thereby promoting the widespread use of airbag-based occupant protection systems.

[Brief explanation of drawings]

FIGS. 1 and 2 show examples of resin coating of the sewing-type airbag of the present invention, in which the shaded area shows the coated area and the blank area shows the non-coated area. Figures 3 to 5 show examples of the structure and resin coating of the bag fabric type airbag of the present invention, in which the shaded area shows the coated part and the blank area shows the uncoated part. FIG. 6 shows a method for testing the impact on the human body when the airbag is inflated. 1: Sewing allowance 2: Inflator attachment section 3: Inflator facing section 4: Pendulum 5: Ultra-thin rubber balloon A, A' 2 long spaced sections B, B', CXC': Short spaced section

Claims (5)

[Claims] (1) An airbag made of a fabric coated with a heat-resistant resin, characterized in that the resin coating is only partial. (2) The airbag according to claim (1), wherein the resin coated portion and the non-coated portion are partially arranged concentrically around the inflator mounting portion and its opposing portion. (3) The airbag according to claim (1), wherein the airbag is made of a bag fabric. (4) Claim (4) wherein the resin coating portion is at least the inflator mounting portion, the opposing portion thereof, and the seam allowance portion (
1) The airbag described. (5) The airbag according to claim (3), wherein the resin coating portion is at least an inflator mounting portion, an opposing portion thereof, and a connecting portion of the bag fabric.