JPH0632190A - Base cloth exhaust type air bag - Google Patents

Abstract

PURPOSE:To increase the mechanical characteristic and gas permeability of an air bag, by constituting at least part of base cloth of a bag main body of gas permeable base cloth, and using twistable yarns for at least part of fiber yarns composing the gas permeable base cloth. CONSTITUTION:At least part of the base cloth of a bag main body in a base cloth exhaust type air bag, discharging gas from the base cloth of the bag main body, is composed of gas permeable base cloth, and twistable yarns are used for at least part of fiber yarns composing the gas permeable base cloth. This can increase the gas permeability, pressure proof strength, and shock proof property of the air bag, having light weight and an excellent flexible folding property, with the gas permeability of the base cloth improved without sharply changing fiber yarn consumption quantity per base cloth unit area controlling the mechanical characteristic of the base cloth (e.g. fabric density of fiber yarns, and weight per base cloth unit area).

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 the safety of passengers in the event of a vehicle collision. More specifically, when the airbag that is deployed at the same time as the collision protects the occupant, the air inside the bag that is required to alleviate the recoil of the occupant is exhausted from the base fabric exhaust type airbag. Regarding

[0002]

2. Description of the Related Art In recent years, airbags have been manufactured by using a non-breathable base cloth and provided with a plurality of exhaust ports to absorb energy when an occupant collides with the bag. However, in addition to the complicated and long processing steps of this bag, the fabric is heavy and stiff, the resulting airbag not only lacks compactness, but also increases the processing cost, resulting in extremely high bag manufacturing cost. There is.

In order to solve these problems, there has been proposed a so-called base cloth exhaust type air bag in which the base cloth itself constituting the bag functions as a gas exhaust filter. The base cloth exhaust type airbag is lightweight, flexible, compact and excellent in processing cost as compared with the conventional exhaust type airbag. For example, the actual Kaisho 58-2
Japanese Patent No. 2360 discloses that a portion with which an occupant comes into contact when an airbag is inflated is made of an impermeable material and an opposite side, that is, a vehicle body side is made of an permeable material, and gas in the bag is discharged from the permeable portion to prevent collision energy of an occupant. A base cloth exhaust type air bag that absorbs and has no exhaust port has been proposed.

However, the breathable base fabric from which gas is exhausted is
After the occupant hits the bag, it is necessary to have an appropriate tissue gap so that gas can permeate in a short time.
On the other hand, mechanical properties are required to withstand the impact force generated when the airbag is deployed, and further the internal pressure of the bag that is increased when the occupant hits it. In order to improve the gas permeability, it is sufficient to increase the tissue gap of the base cloth, but if this is done, the number of fiber yarns used per unit width will decrease, and as a result, the mechanical properties will decrease and the air bag As a breathable base fabric, it was difficult to satisfy both properties.

[0005]

DISCLOSURE OF THE INVENTION The present invention relates to a base cloth exhaust type air bag, in which the gas ejected from a gas generator (hereinafter referred to as an inflator) is discharged to the outside of the bag, that is, breathable. , A breathable base cloth that can satisfy both contradictory mechanical properties that can withstand the tensile stress generated by the inflation of the gas ejected from the inflator and the bag internal pressure that rapidly rises in a short time when the occupant hits it. The purpose is to provide an airbag.

[0006]

According to the present invention, there is provided a base fabric exhaust type air bag for exhausting gas from a base fabric of a bag body.
It is characterized in that at least a part of the base fabric of the bag body is made of a breathable base fabric, and a twisted yarn is used for at least a part of the fiber yarns constituting the breathable base fabric. The base cloth exhaust type air bag of the present invention may be formed by using the breathable base cloth as the whole of the base cloth constituting the airbag, or by forming the breathable base cloth and the impermeable base cloth together. May be. As is well known, this base cloth exhaust type air bag has a structure in which the gas after expansion and expansion of the air bag is discharged through the fiber yarns of the breathable base cloth.

That is, according to the present invention, by using a twisted yarn for at least a part of the fiber yarns constituting the breathable base fabric,
Breathability of the base fabric without significantly changing the amount of fiber yarn used per unit area of the base fabric (for example, the fabric density of the fiber yarn, the weight per unit area of the base fabric), which affects the mechanical properties of the base fabric. And an air bag having improved breathability, pressure resistance and impact resistance. Generally, in order to improve the air permeability of the base fabric, for example, in the case of a woven fabric, the density of the warp and weft is decreased, or the weave structure having few intersections of the warp and the weft (twill weave, satin weave, twill weave, etc.) Should be adopted,
Not only the tensile strength of the woven fabric is lowered, but also the joint strength of the base fabric does not reach a sufficient level. Further, the displacement of the structure of the base fabric itself is likely to occur, and the airtightness for securing the initial internal pressure required at the time of deployment may be impaired.

The present invention focuses on the fact that twisting a yarn reduces the apparent diameter, increases the gaps in the fabric structure, and improves the air permeability of the base fabric. A highly breathable base fabric can be obtained without impairing the mechanical properties. The twisted yarn of the present invention means a yarn obtained by intentionally adding twists, and does not include untwisted twists from cheese or bobbins, and original twists of raw yarns produced during the production of raw yarns.

The twisted yarn used in the present invention may be selected in consideration of both the air permeability and mechanical properties required for the airbag. That is, all the fiber yarns constituting the base fabric may be twisted yarns, or a part thereof may be twisted yarns. In addition, the position within the base cloth may be one to a plurality of bands arranged at equal intervals, or at other regular or irregular positions. When there are a plurality of directions of fiber yarns constituting the base cloth, for example, a warp or weft of a woven fabric, or a triaxial or more multiaxial, weft or warp-inserted woven fabric may be unidirectional or omnidirectional. The yarn may be arbitrarily selected and a twisted yarn may be used.

The number of twists of the twisted yarn may be appropriately selected depending on the thickness of the fiber yarn to be used, the air permeability of the base cloth, the mechanical properties, etc., but is, for example, 20 to 300 times / m, preferably 50 to
You can choose from 250 times / m. When the number of twists is large, not only is the strength reduced, but also the elongation is increased and the dimensional stability of the base fabric deteriorates.On the other hand, when the number of twists is small, the high ventilation characteristics required for breathable base fabrics. Can't get The relationship between the thickness of the thread and the number of twists may be determined based on the required ventilation characteristics, but in general, the ventilation characteristics of the base fabric are
Since the thickness of the yarn, the weaving density of the base fabric, and the number of twists are governed, these factors may be appropriately combined to design the optimum base fabric. Generally, a large number of twists is given to a thick yarn, and a large number of twists is given to a thin yarn. The twisting direction may be either the Z direction or the S direction, but Z and S may be arranged alternately, or in some cases, a plurality of thin yarns may be twisted separately (undertwisting), and these may be combined to oppose the undertwisting. You may add the twist in the direction. Further, in order to improve the stability of twist, twist setting processing such as heat setting and steam setting may be performed.

The types of fiber yarns, including twisted yarns, which compose the main base fabric used in the present invention, include long fibers obtained from melt spinning, dry spinning, wet spinning, and spun yarns obtained from short fibers. Alternatively, a mixed yarn of these, and further, a processed yarn that has been subjected to a bulky process, etc. may be used. Further, the thickness may be selected according to the purpose. The fiber yarn may be a ribbon, tape, braid, or the like, which has been previously formed into a narrow-width aggregate. Also,
It may be cut out from the film or split.

The material of the fiber yarn used for the airbag of the present invention is, for example, polyamide fiber such as nylon 6,66,46, aramid fiber typified by a copolymer with paraphenylene terephthalamide and aromatic ether. ,
Polyester fiber represented by polyalkylene terephthalate, wholly aromatic polyester fiber, vinylon fiber, polyolefin fiber such as ultra high molecular weight polyethylene, polyoxymethylene fiber, paraphenylene sulfone, sulfone fiber such as polysulfone, polyether ether ketone fiber , Polyimide fibers, polyetherimide fibers, carbon fibers, etc., but in some cases, inorganic fibers such as glass fibers, ceramic fibers, metal fibers or the like may be used alone or in combination. The material of the fiber yarn may contain various additives that are usually used for improving the productivity or the characteristics in the manufacturing process and the processing process of the raw yarn. For example, it may contain a heat stabilizer, an antioxidant, a light stabilizer, a smoothing agent, a plasticizer, a thickener, a pigment, a gloss imparting agent, a flame retardant and the like.

The type of the base fabric of the airbag body of the present invention may be a woven fabric, a knitted fabric, a non-woven fabric in some cases, or a laminate of these fabrics. In order to impart mechanical isotropy, a multiaxial (triaxial A woven or knitted fabric, a weft yarn or a warp inserted knitted fabric may be used. The yarns constituting these base fabrics may be selected from those usually obtained such as long fibers, short fibers, mixed yarns thereof, bulky processed yarns and the like.

Further, the method for producing the bag body of the air bag may be carried out by sewing, adhering, thermocompression bonding, vulcanizing, or a combination of these pieces of cloth cut into the required number and shape. Further, the bag structure may be formed by weaving and knitting. The area, position, etc. of the gas discharge portion of the base cloth exhaust type air bag of the present invention may be selected according to the required expansion characteristics of the air bag. The air permeability of the base cloth used as the gas discharge part may be appropriately selected, but the air permeability at a pressure of 0.2 kgf / cm ² is preferably in the range of ²⁰ to 400 cc / cm ² / sec. In order to stabilize the base fabric exhaust characteristics, the airbag
In addition to pretreatment such as scouring and setting, resin processing, physical pressure processing with rolls, etc., stabilization processing of base fabric structure using various energies such as high frequency, ultrasonic wave, electromagnetic field, vacuum or high pressure Good.

When the air bag is composed of a breathable part and an impermeable part, a high density base fabric having a large amount of fiber yarns constituting the base fabric is used as the base fabric forming the impermeable part. It is also possible to use a multi-layered fabric in which the above-mentioned base fabrics are integrated, or a laminated fabric in which a plurality of base fabrics are simply laminated, and chloroprene rubber which is usually used for airbags in various base fabrics used for the breathable part. The above may be applied by a processing method such as coating, dipping, printing, spraying or laminating.

As the treatment agent for impermeable processing, other than chloroprene rubber, for example, silicone type, urethane type,
Polyamide-based, polyester-based, polyacrylic-based, polyolefin-based, halogen-containing polyolefin-based, fluorine-based, chlorosulphonated polyethylene-based, ethylene / propylene copolymer-based elastomers, etc. may be appropriately selected and used from one or more types. Good. These above-mentioned elastomers are reinforcing agents typified by carbon, which are usually used for improving the properties thereof, deterioration inhibitors, vulcanizing agents, vulcanization accelerators, vulcanization retarders, lubricants, plasticizers, antioxidants, It may contain various additives such as a heat stabilizer, a flame retardant, and a pigment.
Furthermore, the joining of these breathable parts and impermeable parts is done by sewing,
It may be performed by a single method or a composite method such as adhesion or cloth making (weaving, knitting).

The airbag according to the present invention is applied to various kinds of bags for driver's seat, passenger's seat, rear seat, door side, etc., and passengers to be protected are also automobiles, ships, railways, airplanes, etc. All transportation options are acceptable.

[0018]

EXAMPLES The present invention will be described below with reference to examples.
Each property in the examples was measured by the following method. (1) Yarn density of the base cloth The number of fiber threads constituting the breathable base cloth is visually measured with a magnifying glass. (2) Strength / Elongation of Base Fabric The strength / elongation of the breathable base fabric at the time of tension was measured according to JIS L-1096. (3) Air permeability of the base cloth The air permeability of the air was measured while the air-permeable base cloth was pressed under 0.2 kgf / cm ² . (4) Stitch deviation of the base fabric Create a seam corresponding to the joint part of the bag, JIS L-1096
According to the procedure, pull the sample until 100 kg of stress is generated,
The stitch deviation (texture deviation) of the seam portion at that time was measured. The sewing conditions at that time are: sewing thread: upper thread nylon 66, 8th thread, lower thread nylon 66, 5th thread, number of stitches: 3.5 times /
cm, seam: two rows of double rings, and the thread axis directions of the two base fabrics were sewn together. (5) Bag deployment test The bag was folded into a module and preheated at 90 ± 2 ° C for 4 hours, and then a deployment test was conducted to observe the maximum bag internal pressure (maxP) and the damaged state of the bag. As the inflator, MORTON type IV was used.

EXAMPLE 1 Nylon 66 filament 420d / 70f untwisted yarn as warp,
Using a twisted yarn of nylon 66 long fibers 420d / 70f (160 times / m, Z direction) as a weft, a plain weave having a weaving density (warp and weft) of 46 yarns / inch was woven to obtain a breathable base fabric. On the other hand, 30 g of silicone resin is added to the base fabric having the same woven density as the breathable base fabric using the untwisted yarn as the weft yarn as the impermeable base fabric.
A coated cloth coated with / m ² was prepared. Both cloths have a diameter of 750
Cut into mm circles. Three reinforcing cloths having an outer diameter of 200 mm were punched out from the impermeable base cloth, sewn in the middle of the breathable base cloth, and a hole having a diameter of 100 mm was punched out at the center to form an inflator attachment port. Four bolt holes and eight rivet holes were punched out around the mounting port. Next, the breathable base fabric and the non-breathable base fabric were combined, and the outer circumference was sewn in two rows of double chain stitch. The inner diameter of the obtained bag was 710 mm. As for the sewing machine thread, the upper thread nylon 66 No. 8 thread, the lower thread nylon 66 No. 5 thread, and the number of hands carried were 3.5 / cm. Table 1 shows the characteristics of the breathable base cloth used and the bag development characteristics. The bag does not have any damage and satisfies the deployment performance as a base cloth exhaust type bag.

Example 2 Nylon 66 filament 420d / 70f for warp and weft
Using a non-twisted yarn, a plain weave having a warp density of 58 warps / inch and weft 56 threads / inch was woven to obtain an impermeable base cloth. On the other hand, the warp is a non-twisted yarn of polyester filament 500d / 96f, and the weft is a twisted yarn of polyester filament 500d / 96f (100
Weaving density (warp and weft) is 4 using the number of turns / m, Z direction)
A plain weave of 4 pieces / inch was woven into a breathable base cloth. Using each of the base fabrics, a bag having an inner diameter of 710 mm was prepared according to Example 1. Table 1 shows the characteristics of the breathable base cloth used and the bag development characteristics. The bag does not have any damage and satisfies the deployment performance as a base cloth exhaust type bag.

Example 3 Polyester filaments 250d / 48f for warp and weft
Using untwisted yarn and twisted yarn (240 times / m, S direction)
A plain woven fabric having a weaving density (warp and weft) of 66 yarns / inch was woven by placing one untwisted yarn and one twisted yarn in both warp and weft directions. From this base cloth, a circular cloth having a diameter of 640 mm was cut, and in accordance with Example 1, an entire surface base cloth exhaust type bag having an inner diameter of 600 mm was prepared. Table 1 shows the characteristics of the base cloth and the development characteristics of the bag. The bag was not damaged at all and satisfied the deployability as a base cloth exhaust type bag.

Example 4 Untwisted yarn of aramid filament 750d / 500f for warp, twisted yarn of aramid filament 750d / 500f for weft (10
A plain woven fabric having a weave density (warp and weft) of 32 yarns / inch was woven by using 0 times / m, Z direction) to obtain a breathable base fabric. On the other hand, a coated cloth was prepared by applying 20 g / m ^{2 of a} silicone resin to a base cloth having the same woven density as the breathable base cloth using untwisted yarns on the weft as the impermeable base cloth. A single-sided exhaust type bag was prepared according to Example 1. Table 1 shows the characteristics of the breathable base fabric used and the bag development characteristics. The bag was not damaged at all and satisfied the deployability as a base cloth exhaust type bag.

Example 5 As a warp, a non-twisted yarn of nylon 66 long fiber 840d / 140f, as a weft yarn, a twisted yarn (120 times / m, S direction) of a nylon 66 long fiber 840d / 140f and a twisted yarn 1
A flat woven fabric having a weaving density (warp and weft) of 28 yarns / inch was woven by using two yarns and two untwisted yarns to obtain a breathable base fabric. On the other hand, all non-twisted yarns were used for the weft as the impermeable base fabric,
Polyurethane resin 40 on the base cloth with the same woven density as the breathable base cloth
A coated cloth coated with g / m ² was prepared. According to Example 1, a bag having an inner diameter of 710 mm was prepared. Table 1 shows the characteristics of the breathable base fabric used and the bag development characteristics.
The bag was not damaged at all and satisfied the deployability as a base cloth exhaust type bag.

Comparative Example 1 A bag was prepared in the same manner as in Example 1 except that a non-twisted yarn was used as the air-permeable base fabric for both the warp and the weft. Table 1 shows the characteristics of the breathable base fabric and the expansion characteristics of the bag. The ventilation property of the base cloth was small, and the bag after deployment also had a blindness in the outer peripheral sewing portion.

COMPARATIVE EXAMPLE 2 In Comparative Example 1, a woven fabric structure was prepared (two rip stop warp yarns and two weft yarns are aligned). Table 1 shows the characteristics of the breathable base fabric used and the bag development characteristics. The ventilation characteristics were improved to a level close to that of the present invention, but the outer peripheral sewing portion of the bag was broken.

Comparative Example 3 In Comparative Example 1, a bag was prepared using a plain weave having a weave density (warp and weft) of 42 yarns / inch. Table 1 shows the characteristics of the breathable base fabric used and the bag development characteristics. By reducing the weaving density, the same level of ventilation performance as that of the present invention can be obtained, but the seam deviation becomes large and the outer peripheral sewing portion of the bag is damaged.

[0027]

[Table 1]

[0028]

EFFECTS OF THE INVENTION The base fabric exhaust type air bag of the present invention uses a breathable base fabric satisfying both mechanical characteristics and high air permeability, and thus is lightweight, flexible, has good foldability, and has excellent practical performance. Is to have.

Claims (1)

[Claims] 1. A base cloth exhaust type airbag for discharging gas from a base cloth of a bag body, wherein at least a part of the base cloth of the bag body is made of a breathable base cloth, and fibers constituting the breathable base cloth. A base fabric exhaust air bag, wherein twisted yarn is used for at least a part of the yarn.