JP2000313295A - Air bag - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an air bag formed with a light flame repellent with good heat resistance. SOLUTION: This air bag is provided with a flame repellent near an inflator mounting opening, and the flame repellent has base cloth composed of fabrics made from fiber yarns of less than 200 denier with 150 g/m2 or less of base weight and 2000 or more of cover factor and comprises a heat resistant elastomer giving surface formed by giving a heat resistant elastomer to the base cloth 15-40% of weight thereof, wherein the base weight is 200 g/m2 or less and melting time at radiating hot air of about 300 deg.C to the heat resistant elastomer giving surface is 2 seconds or more.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention
The present invention relates to an airbag for protecting an occupant, which is lightweight and has excellent heat resistance.

[0002]

2. Description of the Related Art In recent years, airbag systems have become widespread as occupant protection safety devices.
The number of seats for side protection (side bags) and rear seats is increasing.

However, as the number and the number of airbags mounted on the airbags have increased, the weight and size of the airbag system have been required to be reduced, and each component of the system has been designed to be smaller and lighter. Airbag bags have also been reduced in weight by making them non-coated and reducing bag capacity.

[0004] Among them, a portion exposed to the hot gas from the inflator, especially around the inflator mounting opening, is provided with a sewing thread or the like sewn with a base cloth of the airbag body or a reinforcing cloth around the mounting opening. Flame-proof cloths are used to protect them. Conventionally, a base fabric provided with a heat-resistant elastomer such as chloroprene rubber or silicone rubber has been used for a flameproof cloth so as to withstand a high-temperature gas spouted instantaneously from an inflator. Elastomers have been applied and composited. For example, 420
Medium density woven fabric with a warp and weft density of 46 yarns / inch (cover factor 1885) using denier
A base fabric provided with 0 to 80 g / m ² of elastomer was used. This is to use the coating base fabric used as the airbag body as it is as a flameproof fabric, and to provide a heat-resistant layer of a certain thickness by smoothing the relatively uneven surface of the medium density fabric, It is necessary to use a large amount of elastomer, and the amount of the heat-resistant elastomer to be applied is 23 to 46% of the weight of the base fabric itself. Therefore, although the heat resistance of the flameproof cloth is excellent, the weight of the flameproof cloth increases, the manufacturing cost increases, and it is difficult to obtain a lightweight airbag rationally.

For this reason, the development of a base fabric for an airbag which uses thin yarns and has excellent heat resistance has been studied.

[0006] For example, Japanese Patent Application Laid-Open No. Hei 4-352584 discloses that at least one side of a woven fabric having a strength of 15 g / denier or more and a 100 to 500 denier yarn having an oxygen index of 22 or more and a cover factor of 1000 to 2000 is used. Discloses a base fabric for an airbag in which a heat-resistant material of 10 to 90 g / m ² is laminated. However, this fabric is structurally relatively coarse, and the lack of strength resulting from the fabric is compensated for by using high-strength yarns that are 50% or more higher than the strength of commonly used yarns. Is applied to the fabric to ensure airtightness and heat resistance, and the weight of the finally obtained base fabric is rather heavy.

Japanese Patent Application Laid-Open No. 10-194463 discloses that heat resistance is obtained by applying 30 to 50 g / m ² of silicone rubber to the surface of a woven fabric made of 300 to 400 denier yarn and having a cover factor of 1500 to 2500. We propose a relatively light base fabric for airbags.
However, although this base fabric has excellent heat resistance, the amount of silicone rubber applied is large, and the base fabric weight is not sufficiently light.
It is not enough to obtain a lightweight airbag aimed at by the present invention.

[0008]

SUMMARY OF THE INVENTION An object of the present invention is to provide an airbag which is light and excellent in heat resistance at a relatively low cost.

[0009]

SUMMARY OF THE INVENTION The present invention focuses on a flameproof cloth which has not been sufficiently developed in various parts of an airbag, and has made intensive efforts on a material which is lightweight and has excellent heat resistance. By applying an optimal amount of a heat-resistant elastomer to a high-density base cloth using fine denier, an airbag provided with a light-weight, flame-resistant cloth having excellent heat resistance has been invented.

That is, the present invention relates to an airbag provided with a flameproof cloth around the inflator mounting opening, wherein the flameproof cloth has a basis weight of less than 200 denier and a fiber weight of 150 g. / M ² or less, a cover factor of 2,000 or more, a heat-resistant elastomer having a heat-resistant elastomer-formed surface formed by applying 15 to 40% of the weight of the base cloth to the base cloth, and having a basis weight of 200 g. / M
² or less, and about 3
The present invention relates to an airbag, wherein the melting time when hot air of 00 ° C. is emitted is 2 seconds or more.

[0011] The flameproofing fabric of the present invention is composed of a fiber yarn of less than 200 denier as a base fabric, and has a basis weight of 150 g /.
m ² or less, the cover factor is a woven fabric is 2000 or more, using a fabric having a flat surface obtained by weaving very thin thread with high density. The fiber yarn is less than 200 denier, preferably 60 denier or more and less than 200 denier, more preferably 100 denier or more and less than 200 denier. If it exceeds 200 denier, it is difficult to obtain a lightweight airbag aimed at by the present invention.

Further, the basis weight of the base fabric is preferably required to be 150 g / m ² or less 80 g / m ^2, more preferably be in the range of ^{100g / m 2 ~150g / m 2} . Even at 150 g / m ² or more, it is still difficult to obtain a lightweight airbag.

Furthermore, the cover factor of the base fabric is 200
It is important to set the range to 0 or more, preferably 2000 to 2500, and more preferably 2100 to 2500.
In the present invention, it is important to use a woven fabric in which extremely fine yarns are woven at high density as a base fabric of the flameproof cloth. By applying the optimal amount of heat-resistant elastomer to the flat base fabric surface obtained from high-density woven fabric using thin yarn, the applied heat-resistant elastomer does not penetrate or fill the woven structure, Since it can be formed as a shielding layer or a heat insulating layer, the heat-resistant elastomer can be used rationally and effectively. Thus, the present invention can provide a lightweight flameproof cloth having excellent heat resistance.

If the cover factor is less than 2,000, the fabric structure of the base fabric is not dense, so that it is difficult to effectively use an elastomer for imparting heat resistance to the base fabric as a shielding layer. The volume also tends to increase, which is disadvantageous in obtaining a light airbag. On the other hand, if the cover factor exceeds 2500, the basis weight of the base fabric increases and the compactness at the time of folding is also lacking, so that it is difficult to obtain a light airbag.

Here, the fabric cover factor (CF)
Is a index indicating the compactness of the fabric structure is determined from the denier of the fabric warp and weft (D _W and D _F) and textile warp density and weft density (N _W and N _F).

[0016]

(Equation 1)

The most important thing in the present invention is to optimize the amount of the heat-resistant elastomer to be applied according to the basis weight of the base fabric.

That is, the heat-resistant elastomer is provided by
It is necessary to be in the range of 15 to 40%, preferably 20 to 35% of the weight of the base fabric. In some cases, the amount of the heat-resistant elastomer applied is larger than that of the conventionally used flameproof cloth. However, in the present invention, since the base cloth has a small basis weight using a specific thin thread, the obtained flameproof cloth can be obtained. The basis weight of the cloth is smaller than that of the conventional one.

If the amount of the heat-resistant elastomer is less than 15%, the heat resistance of the flameproof cloth is insufficient, and if it exceeds 40%, the heat resistance is excellent, but the weight of the flameproof cloth increases and the production cost increases. The object of the present invention cannot be achieved.

The amount of the heat-resistant elastomer to be applied is large when the basis weight is small, and may be small when the basis weight is large. What is necessary is just to determine the optimal grant amount according to the method and the like.

The basis weight of the flameproof cloth composed of the base cloth and the heat-resistant elastomer is 200 g / m ² or less, preferably 100 g / m ^2.
/ M ² ~200g / m ^2, more preferably 150 g / m ²
The range may be in the range of 200 to 200 g / m ² . If it exceeds 200 g / m ² , it is difficult to obtain a lightweight airbag aimed at by the present invention.

Further, the flameproofing cloth used in the present invention needs to have a melting time of 2 seconds or more, preferably 2.5 seconds or more, when hot air of about 300 ° C. is radiated to the surface to which the heat-resistant elastomer is applied. is there. When the melting time is less than 2 seconds, sufficient heat resistance as a flameproof cloth cannot be exhibited.

The flameproof cloth provided in the airbag of the present invention is applied to the vicinity of the inflator mounting opening. However, other parts and applications affected by the hot gas of the inflator, for example, gas deflecting cloth, exhaust hole reinforcing cloth. , A hanging string, a seam protection cloth, or the like.

The shape of the mounting opening of the inflator of the airbag of the present invention may be selected from commonly used shapes such as a circle, an ellipse, an ellipse, a square, a rectangle, and a rhombus, and is not particularly limited.

The reinforcing fabric used for reinforcing the periphery of the inflator mounting opening of the airbag according to the present invention may be the same fabric as that used for the bag, but separately prepared reinforcing fabric, for example, 840 of nylon 66. A single fabric or a plurality of fabrics thicker than the fabric for an airbag of the present invention, which is made using denier, 420 denier, 315 denier, or 210 denier, may be used.

The flameproof cloth may be sewn by overlapping with these reinforcing cloths. In some cases, the flameproof cloth may be sandwiched between a retainer for fixing the inflator and the reinforcing cloth, or may be inserted into a bolt of the retainer. . The sewing thread used for sewing may be appropriately selected from those commonly used as synthetic fiber threads and those used as industrial sewing threads. For example, nylon 6, nylon 66, polyester, vinylon, aramid, fluorine-based , Carbon, glass, etc., and may be any of spun yarn, filament plied yarn, and filament resin processed yarn.

The airbag of the present invention is characterized by the flameproof cloth to be used, and there is no particular limitation on other structures such as the base cloth of the main body of the airbag and the sewing of the outer periphery thereof. For example, the seam specifications on the outer periphery of the airbag may be appropriately selected from lockstitching, double chain stitching, one-sided stitching, overlock stitching, safety stitching, staggered stitching, flat stitching, and the like. In addition, the sewing condition is determined by the number of the sewing thread to be used, for example, 30th to
The best seam strength may be obtained according to the fifth.

The structure of the flameproof cloth provided in the airbag of the present invention and the fabric used in other parts may be appropriately selected from various looms used for weaving ordinary industrial woven fabrics. , A water jet loom (WJL), an air jet loom (AJL), a rapier loom, a projectile loom, or the like. The texture of the woven fabric may be any of plain weave, slant weave (basket weave), twill weave, lattice weave (rip-stop weave), or a composite structure of these. In some cases, a dobby device or jacquard device is used for the loom. Various irregular organizations may be used together.

Depending on the performance of the inflator, the capacity of the airbag, the location of use, etc., a heat-resistant elastomer may be applied to the fabric constituting the airbag body and other members of the present invention to perform impermeable processing. Alternatively, a non-coated fabric that is not subjected to any impermeable processing may be used. In the case of a non-coated fabric, conditions such as scouring, drying, and heat setting temperature may be selected in consideration of air permeability, mechanical characteristics, and the like.

The fiber yarns constituting the woven fabric are not particularly limited. For example, nylon 6, nylon 66, nylon 46, nylon 610, nylon 612
Polyamide fibers obtained by homo- or copolymerization and mixing thereof; polyethylene terephthalate, polytrimethylene terephthalate, polybutylene terephthalate, polyester fibers obtained by homo- or copolymerization and mixing of these,
Aramid fibers represented by paraphenylene terephthalamide, and a copolymer thereof with an aromatic ether,
Wholly aromatic polyester fiber, vinylon fiber, polyolefin fiber such as ultra-high molecular weight, vinyl chloride and vinylidene chloride fiber, fluorine fiber including polytetrafluoroethylene, polysulfone (PSf) fiber, polyphenylene sulfide fiber (PPS) , Polyetheretherketone (PEEK) fiber, polyimide (P
I) Fiber, polyetherimide (PEI) fiber, cellulosic fiber including high-strength rayon, acrylic fiber, carbon fiber, glass fiber, silicone carbide (SiC)
It may be appropriately selected from fibers, alumina fibers, etc.,
In some cases, inorganic fibers such as metal fibers represented by steel may be included.

Various additives commonly used for improving spinnability, processability, and durability of materials are added to these fiber yarns, for example, heat stabilizers, antioxidants, light stabilizers, and the like.
Anti-aging agent, lubricant, leveling agent, pigment, water repellent, oil repellent,
One or more of a hiding agent such as titanium oxide, a gloss-imparting agent, a plasticizer, and the like may be used. In some cases, processing such as heating, bulking, crimping, and winding may be performed.

Further, the yarn is a filament of a long fiber,
There are no particular limitations on spun yarns of short fibers, composite yarns thereof, and the like.

The heat-resistant elastomer used in the present invention may be any material to which the above-mentioned processing method can be applied. For example, silicone-based, fluorine-based, chlorine-based, polyurethane-based, epoxy-based, polyester-based, polyamide-based, and polyimide-based elastomers can be used. , Chlorsulfone, phenol, acrylic, etc., one or a mixture of two or more, or may be appropriately selected from copolymers, etc., from the viewpoint of improving the mechanical properties of the fabric, heat resistance and the like silicone-based Fluorine and polyurethane are particularly preferred.

The heat-resistant elastomer may be interposed on at least one surface of the woven fabric, a gap between the woven fabrics, or a part or all of the gap between the fiber yarns.

The heat-resistant elastomer may be added with various pretreatment agents for improving the adhesion to the base fabric, an adhesion improver, or the like, or may be subjected to a pretreatment such as a primer treatment on the fabric surface in advance. You may. Further, a processing agent for imparting heat resistance, anti-aging property, oxidation resistance and the like to the elastomer may be added. In order to improve the physical properties of the elastomer, after applying the elastomer to the fabric, drying,
Crosslinking, vulcanization and the like may be performed by hot air treatment, contact heat treatment, high energy treatment (high frequency, electron beam, ultraviolet light) or the like.

The method of applying the heat-resistant elastomer may be a processing method such as 1) coating method (knife, kiss, reverse, etc.), 2) dipping method, 3) printing method (screen, roll, rotary, etc.). The heat-resistant elastomer may be any of a solvent type, an emulsion type, an aqueous solution type, a fine powder type and a non-solvent type.

Further, it is effective to optimize the amount of the heat-resistant elastomer by flattening the surface of the base fabric by subjecting the base fabric to hot pressing such as calendering before applying the heat-resistant elastomer. It is a target.

The application site of the airbag according to the present invention may be appropriately selected from commonly used airbags such as a driver's seat, a passenger seat, a side (including an inflatable curtain), and a rear seat. The cut shape of the bag may be any of a circle, an oval, an ellipse, a rectangle, a polygon, and a combination thereof, and may be any shape that satisfies a desired developed shape.

[0039]

The present invention will be described more specifically with reference to the following examples. In the examples, the performance evaluation of the airbag and the fabric was performed by the following method.

(1) Heat resistance The apparatus shown in FIG. 6 radiates heated air at about 300 ° C. onto the surface of the flameproof cloth provided with the heat resistant elastomer with the distance between the surface and the nozzle being 10 mm to melt the cloth. The time (sec) until the hole was opened was measured. The flow rate of the heated air is 50
L / min, and the nozzle tip diameter was φ2 mm.

(2) Deployment test Using an inflator for driver's seat (non-azide type, maximum tank pressure of 60 liters is 185 kp), a fixing bracket, and a resin cover, the bag is assembled into a folding module.
After preheating at 85 ° C. for 4 hours, a deployment test was performed, the maximum internal pressure of the bag was determined, and the damaged state of the bag after deployment was observed.

Example 1 Nylon 66 fiber 315 d / 72 f (raw yarn strength 9.5 g)
/ D), the woven fabric density, warp 61.5 lines / inch, weft 62
Book / inch plain fabric was woven. The woven fabric was scoured and heat-set to obtain a non-coated woven fabric of 63 pieces / inch in both warp and weft.

Next, from the non-coated fabric, the outer diameter is 720 m.
m, two circular cloths (FIGS. 1 and 2)
An opening of φ70 mm is provided in the center of the as an inflator mounting port, and a circular hole of φ30 mm is provided as an exhaust hole.
There are two places. In addition, as a reinforcing cloth for the inflator attachment port, an outer diameter φ200 mm, an inner diameter φ
Two 70 mm donut-shaped cloths (FIG. 3) were cut.

Next, 140d / 84 is used for flameproof cloth.
Using f (raw yarn strength of 8.0 g / d), a non-coated fabric of 95 warps / inch in both warp and weft was obtained. The basis weight is 132g
/ M ² and the cover factor was 2248. One side of this fabric was coated with a normal silicone rubber, for example, an addition type silicone rubber at 30 g / m ² to obtain a coated fabric. From the woven fabric, one donut-shaped cloth having the same shape as the above-described reinforcing cloth for the mounting port was used as a flameproof cloth for the mounting port, and a donut-shaped cloth having an outer diameter of φ60 mm and an inner diameter of φ30 mm was used as a reinforcing cloth piece of the exhaust port. I cut it.

Next, two pieces of the reinforcing cloth A cut from the non-coated fabric are superimposed on the center of the circular cloth 1, and the seam diameter φ
The pieces were sewn at 195 mm (outer layer) and φ135 mm (middle layer) (FIG. 4 (2)). As the sewing thread, both the upper thread and the lower thread were nylon 66 threads, and the sewing thread was sewn with a 22 st sewing machine needle at a regular stitch with a stitch number of 4 stitches / cm. At this time,
The reinforcing cloth of the exhaust hole was also laid one by one on the exhaust hole of the circular cloth 1 and sewn together at a stitch diameter of 50 mm. Further, a flameproof cloth B (FIG. 4 (1)) cut from the coated fabric was superimposed on the reinforcing cloth around the inflator mounting opening in accordance with the inner diameter of the reinforcing cloth A, and sewn together at a stitch diameter φ76 mm (inner layer). . As the sewing thread, the upper thread and the lower thread were both threaded using nylon 66 thread No. 5, and the number of stitches was 3.5 stitches / cm.

Then, a hole diameter φ is formed around the mounting opening of the inflator of the circular cloth 1 sewn with the reinforcing cloth and the flameproof cloth.
Four 5.5mm inflator mounting bolt holes,
Each hole was opened on a line in the yarn axis direction of the main body cloth (FIG. 5).

Further, the circular cloth 1 and the circular cloth 2 are overlapped with each other at a position where the respective yarn axes are shifted by 45 °, and the circular cloth 1 and the circular cloth 2 are shifted from the outer periphery by 20 mm.
mm inside was sewn together. The sewing thread is nylon 66
The fifth thread of the thread and the eighth thread of the lower thread of nylon 66 were sewn together by double chain stitching (two rows) of 3.5 stitches / cm with a sewing machine needle of the 23rd thread.

The obtained airbag is inverted from the mounting opening,
It was subjected to a deployment test. Further, the heat resistance of the flameproof cloth was also evaluated. Table 1 shows the results.

After the bag was deployed, there was no damage around the inflator mounting opening, and the flameproof cloth had sufficient heat resistance.

Example 2 In Example 1, nylon 66 fiber 120d / 102f (filament yarn strength 6.5 g / d) was used as the base fabric of the flameproof cloth, and the weaving density was 115 / inch and weft 96 / Inch non-coated fabric (weight: 126 g / m ² , cover factor: 2
311) 35 g / m ^{2 of} silicone rubber on one surface
An airbag was prepared according to Example 1, except that the coated fabric was used.

Table 1 shows the deployment test of the obtained airbag and the measurement results of the heat resistance of the flameproof cloth. The unfolded bag had no damage, and the flameproof cloth had sufficient heat resistance.

Comparative Example 1 In Example 1, the amount of silicone rubber applied was changed to (1) 1
The airbag was evaluated in the same manner as in Example 1 except that the amount was 5 g / m ² (2) 55 g / m ² .

In the bag after the development, in the case of (1), the amount of the heat-resistant elastomer applied to the weight of the base cloth was small, and the flameproof cloth and the sewing thread were melted. In the case of (2), the heat resistance is sufficient, but the thickness and weight of the flameproof cloth are increased, and the foldability is increased.
There is a problem in terms of lightness.

Comparative Example 2 In Example 1, a nylon 66 fiber 315d / 72f (raw yarn strength: 9.5 g / d) was used as the base fabric of the flameproof cloth, and the weaving density was 59 and the weft was 59. An airbag was prepared and evaluated in the same manner as in Example 1 except that a 1 / inch fabric (a basis weight was 177 g / m ² and a cover factor was 2094) was used.

Although the bag after expansion has no problem with the heat resistance, the basis weight of the flameproof cloth is high, and there are problems with the foldability and lightness of the bag.

Comparative Example 3 In Example 1, nylon 66 fiber 180d / 72f (filament yarn strength 6.0 g / d) was used as the base fabric of the flameproof cloth, and the woven fabric density was 74 and the weft was 74 / w. An airbag was prepared and evaluated according to Example 1, except that an inch fabric (a basis weight of 130 g / m ² and a cover factor of 1986) was used.

Since the woven fabric structure of the flameproof fabric base fabric was coarser than that of Example 1 after the development, the thickness of the heat-resistant layer on the woven fabric surface was reduced even with the same amount of elastomer, and the heat resistance was poor.

[0058]

[Table 1]

[0059]

As described above, according to the present invention, it is possible to provide a light-weight, excellent heat-resistant, and inexpensive material as a flame-proof cloth around the inflator, which is susceptible to the hot gas, especially around the inflator mounting opening. Therefore, it is possible to obtain a safe and highly reliable airbag which is lightweight and is not affected by the hot gas at the time of deployment.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of a base fabric of one airbag.

FIG. 2 is an explanatory diagram of a base fabric of the other airbag.

FIG. 3 is an explanatory view of a reinforcing cloth for an inflator mounting opening.

FIG. 4 is an explanatory view showing a state in which a reinforcing cloth is sewn to an inflator mounting opening and a flameproof cloth is further sewn thereon;

FIG. 5 is an explanatory view showing a state in which a mounting bolt hole is provided around an inflator mounting opening obtained by sewing a reinforcing cloth and a flameproof cloth.

FIG. 6 is a diagram schematically illustrating an apparatus for measuring the heat resistance of the flameproof cloth.

[Explanation of symbols]

 1 High-pressure air 2 Sample base cloth 3 Heater 4 Nozzle

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Tadao Kanuma 218 Aoshima-cho, Fuji-shi, Shizuoka Prefecture F-term in Japan Plastic Co., Ltd. 3D054 AA02 AA03 AA04 AA16 CC11 CC26 CC34 CC43 CC45 EE20 FF01 FF13 FF14 FF16 FF18 4L048 AA34 AA48 AB07 AC09 BA01 BA02 CA01 CA15 DA25 EB05

Claims (1)

[Claims] 1. An airbag provided with a flameproof cloth around an inflator mounting opening, wherein the flameproof cloth has a base cloth of 20.
The basis weight of the fiber yarn of less than 0 denier is 150
g / m ² or less, and a cover factor of 2,000 or more. The base fabric has a heat-resistant elastomer-applied surface formed by applying a heat-resistant elastomer to the base fabric at 15 to 40% of the weight of the base fabric. An airbag having a melting point of 200 g / m ² or less and a melting time of about 2 seconds or more when hot air of about 300 ° C. is radiated to the heat-resistant elastomer applied surface.