JP3147239B2 - Woven airbag - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an airbag for protecting an occupant safely in the event of a collision of an automobile, and more particularly, to an airbag in which the gas in the bag is released when the airbag deployed at the time of the collision protects the occupant. The present invention relates to a base fabric exhaust type airbag that reduces recoil of an occupant by exhausting air from a woven fabric surface.

[0002]

2. Description of the Related Art Conventionally, airbags generally have a bag-like structure whose entire surface is covered with a rubber-based film, and the air permeability of a cloth is zero, that is, there is no exhaust from the cloth part. there were. Therefore, in order to prevent a sudden increase in the internal pressure of the bag at the time of collision, by providing at least one vent hole having a diameter of 20 to 40 mm on the lower surface of the bag and exhausting from the exhaust hole,
The structure reduces the recoil of the occupant due to the bag.
Since the exhaust of the high-temperature gas from the exhaust hole occurs instantaneously, there is a possibility that the occupant may be burned.

[0003] fabric used in the conventional airbag is coated with a normal 100 g / m ² approximately elastomeric coating material to the air permeability and zero. The coated fabric is heavy and hard, and not only does the airbag lack the compactness, but the processing steps are complicated and long, and the resulting processing cost increases, resulting in extremely high bag manufacturing costs.

[0004] As an airbag which solves these problems, the fabric surface itself functions as a gas exhaust filter.
A so-called base fabric exhaust airbag has been proposed. The base fabric exhaust airbag is superior to a conventional exhaust port airbag in that it is lightweight, flexible, compact, and can reduce processing costs. However, there is a problem to be improved in performance such as ventilation characteristics and heat resistance.

[0005] For example, yarn fraying occurs due to cut cutting, punching, etc. of the base fabric during bag making processing, which leads to a reduction in appearance quality, a reduction in strength, and the like, which occurs during handling if the fabric structure is not fixed. Due to the collapse of the structure of the woven fabric (misalignment of the constituent yarns), the air permeability remarkably fluctuates, and a stable fabric exhaust type bag cannot be obtained. In addition to a high-temperature gas, a combustion residue of a gas generating agent and a fine solid material of a material constituting the inflator are obtained from a gas generating device (hereinafter referred to as an inflator) for expanding and inflating the airbag. And the like are scattered at a high speed in a very short time, so depending on the performance of the inflator, the fabric air exhaust type airbag of the above-mentioned proposal may damage or melt or cut the fabric of the gas exhaust portion by heat, In some cases, the airbag may rupture and fail to perform the occupant protection function.

[0006]

SUMMARY OF THE INVENTION The present invention is concerned with the above-mentioned problems in the base fabric exhaust type air bag, namely, the loss of the air bag's practical characteristics, especially its ventilation characteristics, heat resistance characteristics, etc., is light, flexible and compact. The purpose of the present invention is to provide an improved airbag.

[0007]

According to the present invention, there is provided a bag woven fabric in which a peripheral portion of a hollow portion is surrounded by a single-layered tissue band, and the hollow portion of the bag woven fabric includes a lower cloth and an upper cloth. The upper cloth and the lower cloth are each made of a fabric having an elastomer-rich surface layer formed on the entire surface on one side of its cross section, and one of the fabrics has high air permeability to exhaust inflation gas. It is a woven airbag set to.

[0008] The base fabric exhaust airbag airbag of the present invention is based on a bag body made of a bag fabric, and an upper fabric (a fabric on the occupant side) and a lower fabric (a steering wheel side) constituting a fabric portion of the base material. Fabric) has a layer rich in elastomer on one side of each cross section, and the bag body as a whole forms a structure that allows ventilation of the inflatable gas. After the gas is expanded and expanded, the function of protecting the occupant by the high-temperature gas is provided by suppressing the discharge of the high-temperature gas from the fabric on the steering wheel side as much as possible and suppressing the discharge to the occupant side. Here, the base material of the bag body is, for example, according to a method described in JP-A-1-125446, JP-A-2-158442, JP-A-2-204151, JP-A-2-216342, or the like. The upper and lower fabrics forming the bag portion of the base material are processed into a breathable fabric structure in which a layer rich in elastomer is formed on one side of the cross section.

The elastomer layer formed on one side of the cross section of the woven fabric constituting the bag portion is a layer in which the elastomer is semi-continuously embedded between the yarns constituting the woven fabric and the constituent filaments of the yarn. Thus, the fabric as a whole is provided with air permeability necessary for exhausting the inflation gas of the airbag. Hereinafter, an embodiment of the airbag of the present invention will be described with reference to FIGS. FIG. 1 shows a cross-sectional structure of the airbag. FIG. 2 shows a cross-sectional structure in a use state, that is, a cross-sectional structure in which the bag body of FIG. 1 is formed upside down through a central inflator mounting opening 6. In the figure, the woven fabric constituting the two sack portions of the upper cloth 1 and the lower cloth 1 'is joined to the bag body by a single woven tissue band 2 at each peripheral edge. The two fabrics constituting the bag have a layer 4 rich in elastomer formed on one side of the cross section. In the use state of the airbag, the elastomer layer 4 is directed toward the inside 3 of the bag body.

FIG. 3 is an enlarged view showing the structure of the elastomer layer in the upper cloth 1 or the lower cloth 1 '.
The site is shown enlarged. 3A shows the outer surface of the upper cloth 1, FIG. 3B shows a cross section taken along the line 1B-1B in FIG. 3A, and FIG. 3C shows a cross section taken along the line 1C-1C in FIG. 3A. FIG.
As illustrated in A, the upper cloth 1 is a plain woven fabric 11 woven with a warp 12 and a weft 13, and the elastomer is formed on one side thereof with a warp, a weft, and constituent fibers (filaments) of these yarns.
On the surface of the woven fabric and at the intersecting portions of the yarns of the woven fabric, and exist without filling the voids 15 and 16 of the woven fabric. Then, as shown in FIGS. 3B and 3C, a layer substantially free of the elastomer is formed on the opposite side of the woven fabric. Thus, a breathable structure of the upper cloth 1 (or lower cloth 1 ') is formed, and functions as an inflation gas exhaust surface of the airbag. The air permeability of the upper cloth 1 (or lower cloth 1 ') is such that the air permeability described later is 10 cc / cm ² / sec, preferably 20 cc / cm ^2.
/ Sec, and not less than 300 cc / cm ² / sec. The elastomer occupying the upper cloth 1 (or lower cloth 1 ') is selected from 1 to 10% by weight, preferably from 2 to 8% by weight, based on the bare weight of the fabric.

FIG. 4A shows a base fabric exhaust type airbag in which the bag portion is constituted only by a woven fabric 21 woven from warps 22 and wefts 23 as shown in FIG. A gap (hole) 25 exists between the warp 22 and the weft 23, and a gap 2 also exists between the fibers constituting the warp 22 and the weft 23.
6 and the holes 25 or gaps 26 provide the fabric with air permeability. However, it is technically extremely difficult to adjust the air permeability to a desired value depending on the weave density.

A coating cloth 31 of a conventional elastomer-coated airbag shown in FIG.
Not only are filled with the coating agent, but also the holes 35 between the warp yarns 32 and the weft yarns 33 are covered with the coating agent so that the coating layer 34 forms the warp yarns 32 and the weft yarns 33 as shown in FIG. 5C. An air-impermeable layer is formed so as to cover the surface.

In the present invention, the elastomer 4 is used for the fabric 1
In order to apply it to the surface of 1, for example, by immersing a two-layered woven base fabric in which the periphery of the hollow portion is joined in an elastomer solution, squeezing the solution with a pressure roll, and drying. Can be easily obtained. Because the bag base is a two-layered woven base fabric, even when immersed in an elastomer solution,
The elastomer solution does not penetrate into the hollow portion of the woven fabric, and forms an elastomer layer on the surface layer portions on both surfaces of each woven fabric. Also, even if the solution is squeezed by a pressure roll, the elastomer solution applied to the surface layer hardly migrates to the inner layer portion, is squeezed at the surface layer portion, and is dried as it is. Layers rich in elastomer are formed on the surface layers on both sides of the woven base fabric. The method for applying the elastomer is not limited to the dipping method, and other methods, for example, non-dipping processing methods such as spraying, kiss roll coating, and floating knife coating may be used alone or in combination. In the non-immersion processing, after treating the elastomer solution on one side of the woven base fabric, drying, and then performing the same treatment on the other side. The type of the elastomer solution, the processing conditions, and the like may be appropriately selected depending on the processing method to be used, and are not particularly limited as long as the elastomer layer 4 is formed on the surface layer portion of the base fabric as described above.

In general, in the processing, each of the steps of immersion, squeezing and drying is continuous, the processing speed is 3 to 30 m / min, and the immersion time is as short as 0.5 to 10 seconds. The squeezed liquid is instantaneously finished, and the time required from the start of immersion to the start of drying is at most 60 seconds or less. Therefore, the migration of the elastomer solution hardly occurs, and the air-permeable surface layer is formed stably.

[0015] When the elastomer is applied, the manner of application may differ depending on the fabric composition, solution properties, and processing conditions. In this case, it is also possible to perform a pretreatment process of penetrating or water-repelling the fabric, add a penetrating agent or a water-repelling agent to the solution, adjust the viscosity of the solution, or adjust the processing conditions. The concentration of the elastomer solution is
The amount of the elastomer is determined by the amount of the applied elastomer. However, the amount of the applied elastomer is largely determined by the kind of the elastomer, the solution properties, the ratio of the squeezed liquid, and the like.

The airbag of the present invention has a structure in which the gas after the airbag is expanded and inflated using the specific cloth is discharged through the cloth of the entire bag, that is, the gas exhaust portion. The bag-woven airbag of the present invention is configured such that the high-temperature gas comes into direct contact with the gas exhaust portion by making the bag body a breathable fabric in which an elastomer is imparted to the bag body. Maintain function. As a result, the high-temperature gas can be exhausted to the outside of the airbag without any damage to the fabric surface of the gas exhaust portion in the fabric constituting the airbag.

The bag-woven airbag of the present invention uses an air-permeable fabric provided with an elastomer as a gas exhaust portion.
The gas can be exhausted by using the fabric surface of the gas exhaust unit as a filter while resisting the impact at the time of high-speed expansion. The woven airbag of the present invention is provided with an elastomer so that the yarns of the fabric constituting yarns and the filaments are fixed to each other, so that the yarns at the cut ends are frayed by cutting, punching, or the like during bag making. Is prevented, and handling and quality are improved.

During the bag-making process or during handling of a bag product, the yarns and filaments of the fabric constituting yarn can be prevented from being displaced (structure collapse, misalignment), and a product having stable ventilation characteristics can be obtained. In the bag-woven airbag of the present invention, since the elastomer is applied to the entire surface of the fabric constituting the bag, the amount of the applied elastomer is small, and the airbag can be lightweight and highly flexible.

The woven airbag of the present invention is designed so that the two fabrics constituting the hollow portion of the bag have different air permeability from each other. That is, the low-breathable fabric is a fabric that comes into contact with the occupant, while the high-breathable fabric is disposed on the steering wheel side. In this way, a bag structure is obtained in which the high temperature gas discharged after the expansion and inflation of the airbag is discharged from the steering wheel side as much as possible and the discharge to the occupant side can be suppressed. The air permeability of the air-permeable cloth side of the low air-permeable cloth side is 50c.
It is preferably c / cm ² / sec.

As a method for making the air permeability different, pre-treatments such as denier, density, and structure of two fabrics before applying the elastomer, water repellency, and calendering are performed. Further, the amount and density of the applied elastomer differ depending on the processing method of the elastomer. In addition, after the elastomer is applied, pressure treatment or the like can be performed, but is not particularly limited thereto, and may be appropriately selected according to the required characteristics of the bag.

The configuration of the sachet used in the present invention is as follows.
There are two-layered and multi-layered woven fabrics, and the shape of the hollow portion is circular, circular, polygonal, or a combination thereof, and the size is also various but is not particularly limited.
What is necessary is just to select suitably according to an application and a required characteristic of a bag. In addition, as the structure of the hollow portion fabric or the single-layered bonded fabric, there are plain weave, oblique weave, satin weave, a combination thereof, or a special structure applied to them, and these may be appropriately selected according to the required characteristics. Further, the thread usage, density, etc. may be appropriately selected according to the required characteristics of the bag.

Examples of the woven fiber yarns for an airbag of the present invention include polyamide fibers such as nylon 6, 66 and 46, aramid fibers typified by paraphenylene terephthalamide, copolymers with aromatic ethers, and the like. Polyester fiber represented by alkylene terephthalate,
Polyolefin fiber such as wholly aromatic polyester fiber, vinylon fiber, rayon fiber, ultra-high molecular weight polyethylene, polyoxymethylene fiber, sulfone fiber such as paraphenylene sulfone, polysulfone, polyetheretherketone fiber, polyimide fiber, polyetherimide Fiber, carbon fiber and the like. In some cases, glass fibers, ceramic fibers, long fiber yarn obtained by using inorganic fibers such as metal fibers alone or in combination, bulky processed yarn, short fiber yarn, or a woven fabric using a mixed fiber yarn as a bag body It can also be used.

The elastomer used in the present invention includes chloroprene, silicone, urethane, polyamide, polyester, polyacryl, polyolefin, halogen-containing polyolefin, fluorine, chlorosulfonated polyethylene, and ethylene / propylene. It is appropriately selected from elastomers such as a polymerization system. In order to impart heat resistance, inorganic compounds such as boron-based, phosphorus-based, silica-based, and barium-based, metals such as aluminum, stainless steel, alumina, silica, and zirconium, and organic compounds such as ceramics, melamine, and organic halogens. A highly heat-resistant compound or the like may be used as a mixture with the elastomer.

Further, various additives such as a heat stabilizer, an antioxidant, an antioxidant, a light stabilizer, a plasticizer, a flame retardant, and a pigment may be used.

[0025]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a woven airbag according to the present invention will be described below. In addition, physical properties were evaluated by the following methods. 1. Air permeability High-pressure gas is sent in and the inlet pressure is 0.2 kgf / cm ²
The amount of gas exhausted from the cloth (liter / min) is read by a flow meter, and the amount of exhaust gas is divided by the area of the cloth (cm ² ), and the amount of gas flowing per unit time (sec) per unit area (cm ² ) Was calculated as the air permeability (cc / cm ² / sec).

The rate of change in air permeability after fir is determined by measuring the air permeability by the above-mentioned method after manually pulling the fabric five times in the bias direction, and dividing the increased or decreased air permeability by the initial air permeability. And expressed as white fraction (%). 2. Bag deployment characteristics A deployment test was carried out on a module kept at 90 ± 2 ° C. (the inflator uses morton type IV), and the damage of the airbag was observed and evaluated.

[0027]

Examples 1 to 3 Nylon 66 long fiber yarn (420d / 7
0f), using a loom with a jacquard mechanism, a double-layered fabric having the following weaving configuration (density refers to the finishing density) is a single-bonded tissue band having a hollow portion of 700 mm in diameter and 25 mm in width (dimensions are ) Was produced in a continuous woven fabric in the length direction. After refining and drying the woven fabric, it is immersed in a 10.0% by weight solution of a polyurethane emulsion resin containing a flame retardant having the following formulation and squeezed with a mangle of ² kgf / cm ² (the speed of immersion to squeezed solution is 5 m / m 2). min), drying 100 ° C. × 3 minutes,
A work cloth was prepared by performing a cure set at 180 ° C. for 5 minutes. The work cloth is cut with a band knife at a single bonding tissue band of 740 mm in diameter, and two pieces of the same cloth having a diameter of 200 mm are bonded to the center of the lower cloth side (to be the steering wheel side) with an adhesive. A bag was cut at 100 mm, provided with bolt holes, and used as an inflator attachment port. The airbag was turned over, and an assembly and deployment test was performed on the module. Table 1 shows the characteristics of the obtained work cloth and the characteristics of the airbag. Good results were obtained in both the properties of the work cloth and the characteristics of the bag.

[0028]

[Table 1]

(Blending formulation of processing fluid) Resin (aqueous polyurethane) 7.5 (% by weight) Flame retardant (brominated aromatic compound) 2.5 (% by weight) Crosslinking agent (isocyanate) 0.1 (% by weight) %) Water 89.9 (% by weight)

[0030]

Example 4 A calender roll (working cloth of the above-mentioned Example 1) with the upper cloth as the upper surface and the lower cloth as the rear surface (the lower roll is made of felt and is not heated, the upper roll is made of metal and heated at 160 ° C.)
Nip pressure 2 kgf / cm ² , speed 5 m / min
And a bag was prepared and evaluated in the same manner as in Example 1. Good results were obtained as shown in Table 1 for the obtained work cloth characteristics and airbag characteristics.

[0031]

Example 5 In the same manner as in Example 1, a woven fabric having a weaving structure of a plain weave for both the upper cloth and the lower cloth and a weft density of 43 yarns / in (referred to as a finishing density) was weighed 335 g / m 2. ² ) was prepared, and kiss roll coating was performed on both surfaces with a thickening solution of polyurethane emulsion resin having the same formulation as in Example 1 at 12.0% by weight and 3000 cps, followed by drying at 100 ° C. ×
A work cloth was prepared for 3 minutes at 180 ° C. for 5 minutes. A bag was prepared from the work cloth in the same manner as in Example 1 and evaluated. Good results were obtained as shown in Table 1 for the obtained work cloth characteristics and airbag characteristics.

[0032]

Comparative Example 1 A bag was prepared and evaluated in the same manner as in Example 1 except that the woven component of Example 1 was used without an elastomer treatment. Table 2 shows the obtained fabric characteristics and airbag characteristics.

[0033]

Comparative Example 2 Refining using the two-layer fabric of Example 1
After drying, a solvent-based chloroprene-based rubber solution (solid content 35
%, A viscosity of 40,000 cps) coated by a knife-on-roll method on the front and back surfaces at an application amount of 80 g / m ² (after drying), followed by drying at 80 to 100 ° C and vulcanization at 180 ° C for 10 minutes. A cloth was obtained (processing was performed by a surface coating → drying → vulcanization → backside coating → drying → vulcanization process). A bag was prepared from the processed cloth with the same specifications as in Example 1, and a bias was applied from the center of the mounting opening. 30m in diameter at the opposite position of 250mm in the direction
m exhaust holes were provided. (A reinforcement of 70 mm in diameter was bonded to the exhaust hole with an adhesive). Table 2 shows the obtained work cloth characteristics and bag characteristics.

[0034]

[Table 2]

[0035]

As described above, the airbag of the present invention is composed of a bag body having a breathable elastomer layer formed on the entire surface of the fabric of the bag fabric, so that the airbag is light and flexible and has heat resistance. In addition, since the airbag body itself has a heat-resistant ventilation surface, it is possible to provide a safe airbag without exhaust holes.

As practical characteristics, a change in air permeability due to misalignment (tissue collapse) is small, and a required air permeability can be obtained by changing the woven structure and the amount of the applied elastomer. Further, the bag is not damaged by the hot gas after the bag is inflated and inflated, and has excellent heat resistance.

Furthermore, the airbag of the present invention can be processed at a low price because it can be processed without yarn fraying at the time of cutting the raw fabric and the like.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a bag body showing a bag-woven airbag of the present invention before the airbag is formed.

FIG. 2 is a cross-sectional view of the woven airbag of the present invention.

FIG. 3 shows the fabric structure of the airbag bag substrate of the present invention.

FIG. 4 shows a woven fabric of a conventional airbag without coating.

FIG. 5 shows the fabric structure of a woven fabric coated on the entire surface.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 upper cloth 1 ′ lower cloth 2 single-bonded tissue band 3, 3 ′ hollow portion 4 elastomer layer 5 reinforcing cloth 6 attachment opening 11 cloth 12 warp 13 weft 15 gap between yarns 16 gap between filaments 21 woven cloth 22, 23 Warp 23,33 Weft 25,35 Hole 26 Gap 31 Coated cloth

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-2-158442 (JP, A) JP-A-3-16853 (JP, A) JP-A-4-262937 (JP, A) (58) Field (Int. Cl. ⁷ , DB name) D03D 1/02 D06M 15/00

Claims (1)

(57) [Claims] 1. A hollow woven fabric formed by surrounding a hollow portion with a single-layered tissue band, wherein the hollow portion of the hollow woven fabric is formed of a lower cloth and an upper cloth, and The lower cloth is a woven fabric in which an elastomer-rich surface layer is formed on the entire surface on one side of its cross section, and one woven fabric of the woven fabric is set to have high air permeability to exhaust inflation gas. bag.