JPH04159159A - Base cloth exhaust type air bag - Google Patents

Abstract

PURPOSE:To protect cloth from hot gas and various kinds of flying material so as to improve reliability at the time of operation by covering at least one part of the cloth of a gas exhaust part with permeable shying cover material in a base cloth exhaust type air bag formed to exhaust gas through the cloth forming a bag body. CONSTITUTION:In a base cloth exhaust type air bag, the whole cloth forming the air bag is formed of permeable cloth, or both permeable cloth and impermeable cloth are used jointly to form the air bag so as to have the structure of exhausting gas after the expansion of the air bag through among the filaments of the permeable cloth. In this case, at least one part of a gas exhaust part is covered with permeable cover material. Accordingly, when hot gas passes the material, the gas temperature is lowered, and at the same time, various kinds of flying material is caught. Gas can be thereby exhausted outside the air bag without damaging the cloth of the gas exhaust part in the cloth forming the air bag.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an airbag for protecting the safety of occupants in the event of a collision of a motor vehicle. More specifically, the present invention relates to a fabric exhaust type airbag that uses the airbag fabric surface to discharge the gas inside the bag, which is necessary to alleviate the recoil of the occupant when the airbag is deployed at the same time as a collision and protects the occupant. .

[Conventional technology]

Conventionally, airbags have a bag-like structure whose entire surface is covered with a rubber film, and there is no exhaust air from the fabric portion. As a result, as a measure to prevent the bag's internal pressure from rapidly increasing in the event of a collision, one or more exhaust ports with a diameter of 20 to 40 meters were installed on the underside of the bag, and by exhausting air from the exhaust ports, the recoil of the bag due to the occupant was alleviated. The structure is such that

For this reason, the fabrics used in conventional airbags are usually coated with a covering material of about 100g/n (about 100 g/n) in order to achieve zero air permeability. The resulting airbag becomes hard due to its weight, and not only lacks compactness, but also increases processing costs, making the bag extremely expensive to manufacture.

In order to solve these problems, a so-called base fabric exhaust type air bag has been proposed in which the fabric constituting the bag itself functions as a gas exhaust filter. Fabric exhaust type airbags are lighter, more flexible, and more compact than conventional exhaust port type airbags, and are superior in that they can reduce processing costs.

For example, in Japanese Utility Model Application Publication No. 58-22360, the part that an occupant contacts when the airbag is deployed is made of an impermeable material, and the opposite side is made of a breathable material. A base fabric exhaust type bag without an exhaust port has been proposed that absorbs the collision energy of the vehicle.

However, a gas generator (
Hereinafter, it will be referred to as an inflator. ) In addition to high-temperature gas, combustion residue from the gas generating agent and fine solid materials from the materials that make up the inflator are scattered at high speed in an extremely short period of time, and depending on the performance of the inflator, the gas discharge section This often resulted in damage to the bag's fabric, melting, cutting, and in some cases, bag rupture, and the bag was unable to provide its occupant protection function.

[Problem to be solved by the invention]

The present invention provides a base fabric exhaust type airbag that protects the fabric of the gas exhaust part from hot gas and various flying objects discharged from the inflator, inflates the airbag without any damage, and protects the occupant. The purpose of the present invention is to provide an airbag that is lightweight, flexible, compact, low-priced, and highly practical.

[Means to solve the problem]

The above-mentioned object of the present invention is to provide an air bag in which a part (or at least a part) of a fabric used as a gas exhaust part is covered with a breathable barrier material in a fabric exhaust type air hang. achieved.

The airbag of the present invention is formed by forming the entire fabric constituting the airbag from a breathable fabric or by using a combination of a breathable fabric and an impermeable fabric, and the airbag is expanded as is known. - Has a structure in which the gas after expansion is discharged through the fiber threads of the breathable fabric. By covering at least a portion of the gas exhaust part of the fabric exhaust type airbag with this structure with a breathable barrier material, hot gas passes through the barrier material and the gas temperature decreases. At the same time, it captures various types of flying objects. As a result, the gas can be discharged to the outside of the air bag without any damage to the fabric of the gas discharge part in the fabric constituting the air bag.

Since the airbag of the present invention uses a breathable barrier material, the fabric of the gas discharge part itself can be used as a filter to discharge gas regardless of the area ratio or location of the gas discharge part, and as a result, it is lightweight, The fabric exhaust airbag, which is flexible, compact, and inexpensive, can be made more practical.

As will be described later, the basic configuration of the airbag of the present invention may be designed in consideration of mechanical characteristics, exhaust characteristics, etc.
The present invention is not particularly limited, and can therefore be applied not only to an airbag for the driver's seat having a substantially circular shape, but also to an airbag for the passenger's rear seat or the door side.

The position and shape of the mounting of the shielding material are selected according to the structure of the target airbag and the type of inflator so that it can cover the part of the fabric used as the gas discharge part that is damaged by hot gas. As a result, the hot gas always hits the fabric of the airbag in this area after passing through the shielding material. Therefore, the barrier material may be attached to the entire fabric used as the gas discharge part, or it may be attached to a part of the fabric that is more exposed to hot gas. For example, in the case of an airbag for a driver seat, a shielding material may be attached to all or part of the handle-side fabric.

When attaching the security material, a method such as laminating the security material on the fabric of the airbag and fixing it partially or over the entire surface may be used.

The barrier material must allow the gas ejected from the inflator to pass through without resistance and allow the gas to be discharged and expanded from the bag without delay. Therefore, for example, rubber, resin,
Impermeable materials laminated with films, foils, etc. cannot be used. The air permeability of the barrier material can be selected appropriately depending on the type of inflator used, the shape of the bag, the capacity, etc., but for example, if a material with a porosity in the range of 20 to 80% is used, good.

The material of the bulletproof material is not particularly limited as long as it can withstand the impact of high temperature gas and flying objects ejected from the inflator, but for example, nylon 6.66.
Polyamide fibers such as 46; aramid fibers represented by paraphenylene terephthalamide and copolymers with aromatic ether; polyester fibers represented by polyalkylene terephthalate; wholly aromatic polyester fibers; vinylon fibers; Polyolefin fibers such as Kisanan and ultra-high molecular weight polyethylene; polyoxymethylene fibers; sulfone fibers such as halapenylene sulfone and polyether sulfone; polyether ether ketone fibers; polyimide fibers; polyetherimide fibers; carbon fibers; Made from long fibers, short fibers, or mixed fibers obtained either singly or in combination with inorganic fibers such as glass fibers, ceramic fibers, and metal fibers; cellulose fibers such as cotton and rayon, and protein fibers such as silk and wool. textiles,
One or two of braided fabrics, nonwoven fabrics, mesh-like fabrics, paper, sheets, etc., or composite laminates of these materials may be used. In addition, in order to provide mechanical methods, multi-axis (triaxial,
A four-axis fabric may be used alone or in combination with other fabrics.

Furthermore, in order to further improve the heat resistance of the sealing material, heat-resistant processing may be performed. For example, ■melting to form a barrier layer,
Inorganic compounds such as boron-based, phosphorous-based, silica-based, barium-based, etc.; Metals and ceramics such as aluminum, stainless steel, alumina, silica, and zirconium; ■ Highly heat-resistant compounds such as silicone and fluorine; ■ Melamine, organic Organic highly heat-resistant compounds such as halogens may be applied by coating, dipping, spraying, printing, laminating, etc., but are not particularly limited to these methods.

On the other hand, the fabric constituting the bag body itself of the base fabric inflatable air bag may be any fabric that satisfies the mechanical properties of the bag, and may be appropriately selected from among the materials used for the above-mentioned barrier material. .

The form of the fabric of the bag itself may be a woven fabric, a knitted fabric, in some cases a non-woven fabric, or a laminate of these fabrics, and in order to impart mechanical isotropy, a multiaxial (triaxial, quadriaxial) woven or knitted fabric, weft or A warp-inserted knitted fabric or the like may also be used. The yarn constituting these fabrics may be selected from commonly available yarns such as long fibers, short fibers, mixed yarns thereof, and bulky yarns.

Furthermore, the method of manufacturing the airbag body is based on the required number of bags,
The fabric piece cut into a shape may be sewn, bonded, heat-pressed, vulcanized, or a combination thereof may be used. Alternatively, the bag structure may be created by weaving or knitting.

The area, position, etc. of the gas discharge portion in the airbag may be selected depending on the required expansion characteristics of the bag. The air permeability of the fabric used as the gas discharge part may be selected as appropriate, but for example, it is preferable that the air permeability at a pressure of 0.2 kgf/cj is in the range of 20 to 300 cc/crl/sec.

In order to stabilize the exhaust characteristics of the base fabric, in addition to pre-treatment such as scouring and setting, the bag is subjected to various treatments such as resin processing; physical pressure processing using rolls, etc.; high frequency, ultrasonic, electromagnetic field, vacuum or high pressure. Stabilization processing of the fabric structure using energy; etc. may also be performed.

In addition, when the airbag is composed of a breathable part and a non-breathable part, the fabric constituting the non-breathable part may be any of the various fabrics used for the breathable part, such as chloroprene rubber, which is normally used in airbags. , coating, dipping, printing,
It can be applied by spraying, laminating, etc., but in addition to chloroprene rubber, treatment agents include silicone-based, urethane-based, polyamide-based, polyester-based, polyacrylic-based, polyolefin-based, halogen-containing polyolefin-based, and fluorine-based. , chlorosulfonated polyethylene, ethylene/propylene copolymer, and the like.

When artificial fibers are used for the airbag body itself and the fiber threads, nonwoven fabrics, sheets, etc. that make up the airbag material, the raw material polymer contains various additives that are normally used, such as heat stabilizers, anti-aging agents, etc. agents, antioxidants, light stabilizers, hundredth improvers, antistatic agents, plasticizers, thickeners, flame retardants, pigments,
etc. may also be used.

Note that the porosity indicating the air permeability of the barrier material is determined by the following formula.

W: Fabric weight (g) S: Fabric area (C1ll) T: Fabric thickness ((to)) e: Specific gravity of fabric constituent fibers 〔Example] The present invention will be explained in detail below with reference to Examples.

In this example, the performance of the airbag was tested by a deployment test. In other words, we conducted an expansion test on a module (inflator used is MORTON TYPE-IV) kept at 2°C for 90 days to determine the damage to the bar knob body.
P-T characteristics (relationship between bag internal pressure and expansion time) were evaluated. In the P-T characteristics in Table 1, which will be described later, P2 indicates the secondary pressure in the bag, P2T indicates the time to reach the secondary pressure, and PoT indicates the time for the pressure in the bag to reach O.

Backing ↓ A plain woven fabric with nylon 66 long fibers of 420 denier and a weft/warp density of 46 threads/inch was created, and a base fabric exhaust cloth (air permeability 180c) was created.
c/cm/sec-at O, 2kgf/cm). - On the other hand, a coated cloth obtained by applying 30 g/rrf of chloroprene rubber to the above-mentioned cloth was used as a gas barrier cloth. A bag was created by cutting both sides into a circle with a diameter of 750 mm and sewing the outer periphery with a seam allowance of 25 mm (sewing conditions: double ring method, two steps sewing,
Both the upper and lower sewing machine threads use nylon No. 66.8, sewing pitch: 3m, sewing interval: 5 threads). Further, in the center of the base fabric exhaust side of the bag, the coated cloth cut into a diameter of 200 mm was integrally bonded with adhesive as a reinforcing cloth, and a hole with a diameter of 100 mm was made in the center for attaching an inflator. I created an airbag with a mouth. Furthermore, an airbag was created in which 70 g/rrf of polyester long fiber nonwoven fabric with a porosity of 70% was laminated on the entire right side of the base fabric exhaust inside the airbag. (The reinforcing fabric part and the seam allowance part outside the sewing area with a diameter of 720 mm were glued and fixed.) This airbag was turned over, assembled into a module, and subjected to an expansion test using the test method described above. The results obtained are shown in Table 1. As is clear from Table 1, although the inner nonwoven fabric was melted, no damage to the bag body was observed.

Using an air bag with the same configuration as in Example 1, an air bag with the same configuration as in Example 1 was used, and on the inside of the bag, on the exhaust side of the base fabric, a plain fabric (porosity: 63%) of 400 denier long aramid fibers and a weft/warp density of 40 threads/in (porosity: 63%) was fabricated with a diameter of 300 nm. Cut it into pieces and use it as a flake cloth.
An airbag was created by laminating and bonding the reinforcing fabric part of the installation port. This bag was assembled with the same specifications as in Example 1 and the same test was conducted. The results are shown in Table 1. In Example 2, no damage was observed to either the aramid cloth (barrier material) on the inner surface of the bag or the bag body cloth.

High-density fabric (air permeability 50CC/CI+
1/sec-at 0.2kgf/cIIl) and a weft/warp density of 40 pieces/in (air permeability 160cc/in).
aj/sec -at 0.2 kgf/cm), cut both sides into a circle with a diameter of 750 mm, and sewed the outer periphery with a seam allowance of 25 to create a bag (sewing conditions: double ring method, two-step sewing) , both the upper and lower sewing machine threads are nylon 66 and number 8, sewing pitch: 311II11, sewing interval: 5+ma). Furthermore, in the center of the low-density right side of the bag, the high-density cloth is placed with a diameter of 2
An air bag was created by using the same material cut to 0.00 mm and integrally bonded with adhesive as a reinforcing cloth, and with a hole of 100 mm in diameter in the center as an inflation flake attachment opening. Furthermore, long glass fiber yarn 60 is attached to the exhaust surface side of the base fabric on the inner surface of this airbag.
0 denier, plain fabric with a weft/warp density of 40/in (porosity 7
0%) was cut to a diameter of 300 aaa and laminated and adhered to the reinforcing fabric portion of the inflator attachment port to create an air bag.

This bag was assembled according to the same specifications as in Example 1 and the same test was conducted. The results are shown in Table 1. In Example 3, no damage was observed to either the glass cloth on the inner surface of the bag or the bag body cloth.

The same test as in Example 1 was conducted using an air bag having the same configuration as in Example 1, but without providing a shielding material on the inner surface of the bag. The results are shown in Table 1. The main body fabric of the hang was damaged, and many large and small melt holes were generated in the exhaust part of the base fabric around the reinforcing fabric.

The airbag has the same configuration as Hokkai Opening Example 2, and the inside of the bag has the following:
Add 50 g/n of chloroprene rubber to aramid cloth of the same composition (
The same test as above was conducted using an impermeable cloth. The results are shown in Table 1. In Comparative Example 2, the bag main body fabric was damaged (many sized melt holes were generated in the base fabric exhaust part around the aramid fabric).

Margins below [Effects of the Invention] The airbag according to the present invention has the characteristics of being lightweight, flexible, compact, and inexpensive as a fabric exhaust type airbag, and also prevents damage to the air hang bag itself due to hot gas. It has excellent practicality.

Claims (1)

[Scope of Claims] In a fabric exhaust type airbag that discharges gas from a fabric constituting the bag body, at least a portion of the fabric used as a gas discharge part is covered with a breathable barrier material. An airbag characterized by: