JPH08268195A - Air bag - Google Patents

Abstract

PURPOSE: To provide an air bag for occupant protection with a large capacity, which is formed by using two sheets of fabrics, under a reasonable bag manufacturing process. CONSTITUTION: The outer periphery of a pair of foundation cloths A and B having the same form which compose a hollow part has a trapezoidal form with equal legs, and the parts of the outer periphery of the trapezoid other than the upper side So and the parts neighboring the corners Q1 and Q2 of the base are connected along the outer periphery, and a bag body is formed by extending making the base of the trapezoid as the abutting surface of an occupant, and the oblique sides S1 and S2 as the side surfaces. By superposing the oblique sides S1 and/or S2 on the base D by making the corners Q1 or Q2 as a starting point, the surface formed by bending the foundation cloths A and B to the outer side respectively in the vertical direction is sewn up to the corners in the form including a convex curve.

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 body of an occupant in the event of a vehicle collision, and more particularly to an airbag such as a passenger seat or a rear seat.

[0002]

2. Description of the Related Art In an airbag system which has been put into practical use as a safety device for protecting an occupant, the parts to be installed from an initial driver's seat to a passenger's seat and further to a rear seat are spreading. Of these, the front passenger seat and the rear seat are usually located in a plurality of places for a plurality of passengers, and the space for storing the airbag system is wide.
You need double the size.

Further, since the length from the inflator mounting portion when the air bag is inflated to the surface for receiving the human body (hereinafter referred to as depth) is longer than that of the driver's seat, two pieces like an airbag for a driver's seat are used. In the method of cutting the cloth into the same shape and making it into a bag relatively easily by sewing or adhering,
Since a satisfactory shape cannot be obtained and it is necessary to make it into a three-dimensional shape at the stage of bag making (sewing), considerable labor and skill are required.

For example, in Japanese Unexamined Patent Publication No. 3-136942, three or more cloths are sewn to have a depth. Therefore, although the depth can be obtained, there are many steps of sewing a straight line and a curved line in three dimensions, workability deteriorates, automation becomes difficult, and the manufacturing cost increases. In order to avoid such a situation, for example, Japanese Patent Laid-Open No.
In JP-A-220943, a tubular bag-like weave is used, and further, a predetermined portion is made into a single-weave, thereby reducing the sewn portion,
It is disclosed that automation becomes possible and productivity is greatly improved.

However, since the corners of the airbag obtained by this method are sewn in a straight line, the occupant contact surface has a rectangular shape, and the occupant may hit the corners.
Further, since there are corners, there is a problem that stress tends to concentrate and burst strength becomes weak.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to enable a flat portion to be sewn on an airbag, such as a passenger seat or a rear seat, which requires a depth, but has a three-dimensional shape. In addition, it is to provide an airbag in which manufacturing cost is rationalized by improving productivity.

[0007] Furthermore, since it is possible to obtain a three-dimensional shape with no corners with a small number of fabrics of two or less, it is intended to provide an airbag having high burst strength.

[0008]

Means for Solving the Problems The inventors of the present invention have made extensive studies in order to achieve the above object, and completed the present invention. That is, according to one aspect of the present invention, the outer peripheral portion is formed of a pair of base fabrics having an [isopodal] trapezoidal shape and having a hollow portion between the base fabrics, and the vicinity of the trapezoidal upper side portion and the bottom side corner portion of the outer peripheral portion. A part which is joined along the outer circumference except for the bottom part and which can be stretched so that the bottom part of the contact surface of the occupant becomes the side surface, and the bottom part is bent at the corner part of the bottom part. An airbag for protecting an occupant, characterized in that the base fabric of the flat portion obtained by re-extending the hypotenuse portion in the vertical direction is sewn in a convex curved shape to the bottom corner portion, Is.

Further, according to the present invention, the outer peripheral portion is formed of a pair of base cloths having an isosceles trapezoidal shape and a hollow portion between the base cloths. A part which is joined along the outer periphery except for the bottom part is a bag body which can be stretched so that the oblique side part of the contact surface of the occupant becomes the side surface,
A base fabric of a flat portion obtained by bending the hypotenuse portion with the corner portion of the base as a base point and shifting the hypotenuse portion in parallel with the base portion or by shifting so as to be oblique to the base portion and re-extending the hypotenuse portion in the vertical direction. An airbag for protecting an occupant, characterized by being sewn to a corner portion of a base in a convex curved shape.

In the airbag of the present invention, a pair of base fabrics A and B having the same shape forming the hollow portion have an isosceles trapezoidal shape, and the corners of the upper side So and the bottom side D of the outer periphery of the trapezoidal shape. Part Q
₁ and Q ₂ are joined together along the outer circumference, and the base of the trapezoid is a bag body that is stretched so that the bottom is the contact surface of the occupant and the hypotenuses S ₁ and S ₂ are the sides. With the part Q ₁ or Q ₂ as the base point, the sides of the hypotenuses S ₁ and / or S ₂ are overlapped on the bottom side D, and the faces formed by bending the base fabrics A and B outward in the vertical direction are the corners. On the other hand, by sewing with a convex curve, it is possible to obtain a bag in which the developed shape is composed of a curve as a whole. Therefore, the occupant contacting surface can have a shape close to a sphere. When sewing with a shape that does not include a curve, a corner is formed (see Fig. 1).

The airbag of the present invention has a hypotenuse S ₁ and
Or S ₂ by the superimposed shifting to parallel or bottom D and skew and bottom D, on the shape as seen from the side, can be different curvature below. That is, by changing the shift amount, it is possible to fill the space in front of the occupant that differs depending on the vehicle type. Further, since the airbag of the present invention has a feature that it can exhibit sufficient performance in an airbag in which the pair of base fabrics A and B forming the hollow portion are not coated, it is lightweight, compact and inexpensive. Bags can be provided.

The airbag of the present invention also includes an airbag in which at least a part of the outer peripheries of the pair of base fabrics A and B having the same shape which form the hollow portion are joined by a single-bonded structure. In this case, the sewing process is further reduced, so that the productivity can be improved. The present invention will be described in more detail below. FIG. 1 is a plan view showing an example of an airbag according to the present invention. Trapezoidal sides S ₁ and S of two base fabrics A and B
₂ is overlaid on the bottom side D as shown in FIG.
A convex curve is sewn to the corner between the EP and RFT to form a passenger contact surface. The inflator attachment port is created by utilizing the trapezoidal upper side So. FIG. 3 is a schematic side view of the airbag according to the present invention when it is inflated. FIG. 3- (1) shows a case where the hypotenuse is overlapped with the bottom side D, and FIG. 3- (2) shows a case where the hyposide is displaced from the bottom side. Is.

Reference numerals 1 to 3 denote sewing lines or tie single-tissue bands. Since these sewing operations can be performed in a flat state, automation, which has been difficult to achieve in the past, can be easily performed. Therefore, a large cost rationalization can be achieved. Moreover, S shown in FIG.
_The shape viewed from the side surface can be changed by changing the shift of the superposition of ₁ and S ₂ with respect to the bottom D. When there is no displacement, the side shapes are symmetrical with respect to the top and bottom. When the shift amount C is increased, the difference in the vertical curvature between the side shapes becomes large. The shifting method is D and S ₁ and / or
D and S ₂ may be parallel to each other or may be oblique to each other, and may be selected according to the required bag shape.

As described above, according to the present invention, it is possible to obtain an airbag having two or less fabrics A and B, or even one fabric, in which the occupant contact surface has a three-dimensional shape. The basic shape of the cloth used in the present invention is an isosceles trapezoid, but it may be an isosceles trapezoid in order to fill the necessary space depending on the mounting position in the vehicle. The airbag of the present invention is
It is necessary to provide a mounting port for mounting the gas generator. The position at which the mounting port is provided may be specified by the deployment shape of the airbag, the module shape, and the like, and is normally provided near the center of the trapezoidal upper side So shown in FIG. The shape of the mounting port may be specified from the shape of the gas generator, the shape of the module, etc., and is usually rectangular, circular,
It may be oval or polygonal. Further, for reinforcement around the opening of the mounting opening, if necessary, a plurality of reinforcing cloths may be separately prepared and fixed by sewing or the like.

The exhaust method for positively and quickly exhausting the gas from the bag after the airbag according to the present invention is deployed may be provided with a punching-type exhaust hole, or the weave structure may be changed to change the vent filter portion. May be provided. Further, the position, area, number and shape thereof may be specified according to the exhaust performance and shape of the airbag, the mounting position and the like. The bag according to the present invention may be provided with a strap in order to reduce the impact force on the occupant due to the protrusion from the module and to stabilize the shape of the bag early at the time of initial deployment. As for the strap material, a base cloth cut into strips may be sewn or may be broken or extended at the time of deployment of the airbag to absorb the protruding energy of the bag and to control the deployment shape. Items may be sewn or woven. The thread used for sewing or weaving is a high-strength thread that withstands the impact force at the time of deployment, a high-strength thread made of thick denier,
Alternatively, it may be an unstretched yarn capable of expressing high elongation, or a sewing yarn that is usually used for suturing an airbag. Further, a yarn capable of exhibiting high extensibility, for example, a bulky processed yarn or a crimped processed yarn having a breaking elongation of 200% or more, preferably 300% or more may be used. Furthermore, the unstretched yarn, for example, a polyamide fiber unstretched yarn, preferably has a breaking elongation of 200% or more, more preferably 300% or more, and a thickness of 2000 to 8000.
The thread of d may be used, but it is not particularly limited.

Further, the bag-making method of the bag body is performed by sewing, adhering, weaving and knitting the outer peripheral portion at the same time, or by using these together. Further, the material constituting the bag body of the present invention may be normally laminated with rubber or resin to be impermeable, or depending on the type of inflator, the bag capacity, and the site where the bag is used, only a part is impermeable. It is not necessary to apply a permeable treatment or, in some cases, to perform no impermeable treatment at all.

The cloth used in the present invention may be any cloth as long as it satisfies the requirements for bag production, bag extensibility, mechanical properties, durability, occupant collision energy absorption, and the like.
It may be appropriately selected from a braid, a non-woven fabric, a film, a ribbon, a tape, a slit of a film, a sheet such as a split, or a laminate thereof. The yarns constituting these cloths are long fibers obtained from melt spinning, dry spinning, wet spinning, etc., spun yarns obtained from short fibers, and twisted yarns thereof, plied yarns, or a combination thereof, and May be a textured yarn that has been bulked or the like. Further, the thickness may be selected according to the purpose.

The material of the yarn is, for example, nylon 6,
Polyamide fibers such as nylon 66 and nylon 46; aramid fibers such as paraphenylene terephthalamide and copolymers with aromatic ethers; polyester fibers such as polyalkylene terephthalate;
Wholly aromatic polyester fiber; vinylon fiber; rayon fiber; polyolefin fiber such as ultra-high molecular weight polyethylene; polyoxymethylene fiber; sulfone-based fiber such as paraphenylene sulfone and polysulfone; polyether ether ketone fiber; polyimide fiber; polyether imide In some cases, fibers; carbon fibers and the like; glass fibers; inorganic fibers such as ceramic fibers and metal fibers may be used alone or in combination.

The yarn material may contain various additives which are usually used for improving the productivity or the characteristics in the continuous yarn manufacturing process and processing process. For example, heat stabilizer, antioxidant, light stabilizer, leveling agent, plasticizer, thickener,
It may contain a pigment, a luster imparting agent, a flame retardant and the like.

[0020]

The present invention will be described below with reference to examples. In the examples, the performance evaluation was based on the following method. (1) Observation of deployment shape of occupant contact surface Using a compressor, air was introduced into the airbag and the deployment shape was visually observed. (2) Bursting Strength As shown in FIG. 4, the burst strength was measured with a burst tester.

After the balloon 5 having a larger volume when inflated than the airbag 4 is put in the airbag 4, the airbag 4 is attached to the airbag attaching plate 6 by using the attachment 7. High pressure air 11 supplied via the conduit 8 by the pressure regulating valve 10.
The air bag 4 was inflated together with the rubber balloon 5 while the supply amount of the air bag 4 was adjusted, and the pressure when the air bag 4 ruptured was measured by the pressure gauge 9 to obtain the burst strength.

[0022]

[Example 1] Nylon 66, 420d for warp and weft
/ 70f was used to prepare a cloth in which a plain woven fabric woven at a density of 53 pieces / inch × 53 pieces / inch was coated with 40 g / m ^{2 of} silicon rubber. As shown in FIG. The upper edge So is 26
0mm, bottom part D is 1540mm, height h is 900mm
Two isosceles trapezoidal base fabrics (hereinafter, A and B) were cut. For reinforcement, the same cloth as the base cloth A was prepared in the mounting opening portion at a size of 150 mm from the mounting opening basic line, one for each of the A side and the B side.

First, a mounting port reinforcing cloth was set at a predetermined position and was sewn by a lock stitch using a sewing thread of 1260d to form a rectangular mounting port having a long side of 200 mm and a short side of 60 mm. Next, the base fabrics A and B were overlapped, and the oblique sides S ₁ and S ₂ and the bottom side D were sewn by double chain stitch using the sewing thread 1260d. Further, the sewing lines of the hypotenuses S ₁ and D and the hypotenuses S ₂ and D are overlapped with each other, and straightened to a vertical plane to be flattened. On the plane, points E and F of 280 mm to the left and right from the center of D are placed. An arc of γ = 370 mm passing through was drawn, and the curved locus portion on the cloth was sewn by double chain stitch using the sewing thread 1260d. The number of hands carried was 35 needles / 10 cm.

A rubber tube of a compressor was set in the mounting port of the obtained bag, air was introduced, and the shape of the occupant contact surface after deployment was observed. The burst strength was measured by the burst test device described above. The results are shown in Table 1. The developed shape was almost circular and was good, and the burst strength was 119 KPa and there was no problem.

[0025]

Example 2 The same base fabrics A and B as in Example 1 were prepared, and they were piled up in the same manner, and the hypotenuse and the bottom were sewn together, respectively, and then, as shown in FIG.
As shown in, the hypotenuses S ₁ and D and the hypotenuses S ₂ and D are 100m
After being set by shifting by m, E and F were obtained in the same manner as in Example 1 and sewing was performed with similar curves. The bag obtained was evaluated in the same manner as in Example 1, and as a result, as shown in Table 1, the bag had a good developed shape and had no rupture strength.

[0026]

[Example 3] The same raw yarn as in Example 1 was used as the warp and weft, and a non-coated plain weave fabric having a density of 53 yarns / inch x 53 yarns / inch was prepared, and the same conditions as in Example 1 were used. I made a bag. The silicone rubber coated cloth used in Example 1 was used as the attachment port reinforcing cloth. Table 1 shows the evaluation results of the obtained bags.
Shown in Both the developed shape and the burst strength were good.

[0027]

Example 4 Nylon 66 fiber 420d for warp and weft
/ 70f using a rapier loom with jacquard, a plain weave with a warp and weft weaving density of 53 yarns / inch, and an isosceles trapezoidal outer circumference joined with a knotted single tissue band Was woven. The outer peripheral joint was a twill weave. This woven fabric was refined and heat set to obtain a non-coated hollow weave base fabric. From this base cloth, a trapezoidal bag was sampled by melting and cutting with a hot knife along the outside of the outer peripheral joint. The inside size of the trapezoid is 260mm at the top and 154 at the bottom.
0mm, height 900mm, outer peripheral joint width 15mm
Met.

An air bag was prepared in accordance with Example 1 by superposing the joined single-tissue bands on the hypotenuse and the bottom. For the mounting port, open the trapezoidal upper junction single tissue band,
It was created under the same conditions as in Example 1. The evaluation results of the obtained bag are shown in Table 1. The shape of the passenger contact surface is almost circular,
There was no problem with the burst strength.

[0029]

[Comparative Example 1] The same trapezoidal woven non-coated base fabric as in Example 4 was used, and the hypotenuse and the bottom were overlapped in the same manner as shown in Fig. 2- (3).
A bag was made by sewing on a straight line passing through E and F as shown in FIG. The mounting port was created according to Example 4. The evaluation results of the obtained bag are shown in Table 1.

The occupant contacting surface after the expansion was square at all four corners. The burst strength was 86 KPa, which was lower than that in Example 4.

[0031]

[Table 1]

[0032]

The airbag according to the present invention can have a three-dimensional shape almost equal to that of the conventional airbag made of three or more sheets, while using two base cloths. It is suitable for large-capacity airbags such as passenger seats and rear seats. Moreover, since the airbag of the present invention can process the flat portion in the bag making process, it can be easily automated and the cost can be greatly rationalized.

[Brief description of drawings]

FIG. 1 is a plan view showing an example of an airbag according to the present invention.

FIG. 2 is a schematic cross-sectional view seen from the direction of an occupant contact surface a shown in FIG. FIG. 2- (1) is a cross-sectional view of the present invention in which a hypotenuse and a bottom are overlapped and sewn in a curved line. FIG. 2- (2) is a cross-sectional view of the present invention in which the oblique side and the bottom side are not overlapped but are displaced and sewn in a curved line. FIG. 2- (3) is a cross-sectional view other than the present invention in which the hypotenuse and the bottom are overlapped and sewn in a straight line.

FIG. 3 is a side view showing an example when the airbag is deployed.

FIG. 4 is an explanatory diagram of a burst test device used to measure the burst strength of an airbag.

FIG. 5 is a schematic development drawing in the case of the first embodiment.

FIG. 6 is a schematic development drawing in the case of Comparative Example 1.

[Explanation of symbols]

A, B: Base of isosceles trapezoid of the present invention So: Upper side of isosceles trapezoid of the present invention S ₁ , S ₂ : Oblique isosceles trapezoid of the present invention Q ₁ , Q ₂ : Bottom of isosceles trapezoid of the present invention Corners D: bottom of isosceles trapezoid of the present invention h: height of isosceles trapezoid of the present invention C: shift amount of hypotenuse and bottom of the present invention E, F: 280 m from the center of the bottom portion to the left and right respectively
m point O, P: point where γ = 370mm arc passing through E intersects with occupant contact surface outer circumference L RT: point where γ = 370mm passing through F intersects occupant contact surface outer circumference L 1: hypotenuse of isosceles trapezoid Part of sewing line or connecting single tissue band 2: Bottom of isosceles trapezoidal part or connecting single tissue band 3: Line of slanted side and bottom side sewn with curved line 4: Air bag 5 : Balloon 6: Airbag mounting plate 7: Airbag mounting 8: Conduit 9: Pressure gauge 10: Pressure adjusting valve 11: High pressure air

─────────────────────────────────────────────────── ───

[Procedure amendment]

[Submission date] May 10, 1995

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0013

[Correction method] Change

[Correction content]

Reference numerals 1 to 3 denote sewing lines or tie single-tissue bands. Since these sewing operations can be performed in a flat state, automation, which has been difficult to achieve in the past, can be easily performed. Therefore, a large cost rationalization can be achieved. Moreover, S shown in FIG.
_The shape viewed from the side surface can be changed by changing the shift of the superposition of ₁ and S ₂ with respect to the bottom D. When there is no displacement, the side shapes are symmetrical with respect to the top and bottom. When the shift amount C is increased, the difference in the vertical curvature between the side shapes becomes large. The shifting method is D and S ₁ and / or
D and S ₂ may be parallel to each other or may be oblique to each other, and may be selected according to the required bag shape.
The airbag of the present invention is sewn with a convex curve.
Formed by OEP and Q1 and / or RFT and Q2
By removing the outer side of the sewing line of the triangular part,
Lightweight ones are obtained. Fig. 5 shows that it can be formed near both corners of the bottom.
FIG. 7 is a development view of the base cloth when the triangular portion is cut away. Also,
FIG. 6 shows the OEP and RFT shown in FIGS.
FIG.

[Procedure Amendment 2]

[Document name to be corrected] Drawing

[Name of item to be corrected] Figure 2

[Correction method] Change

[Correction content]

[Fig. 2]

Claims (4)

[Claims] 1. The outer peripheral portion is formed of a pair of base cloths having an isosceles trapezoidal shape and having a hollow portion between the base cloths, and a portion of the outer peripheral portion excluding the vicinity of the trapezoidal upper side portion and the bottom side corner portion. A bag body that is joined along the outer circumference and that can be stretched so that the bottom side is the contact surface of the occupant so that the hypotenuse side is the side surface. An airbag for protecting an occupant, characterized in that a base cloth of a flat portion obtained by re-extending the oblique side portion in a vertical direction is sewn to a corner portion of a bottom side in a convex curved shape. 2. The outer peripheral portion is formed of a pair of base cloths having an isosceles trapezoidal shape and having a hollow portion between the base cloths, and a portion of the outer peripheral portion excluding the vicinity of the trapezoidal upper side portion and the bottom side corner portion. A bag body that is joined along the outer periphery and can be stretched so that the bottom side is the contact surface of the occupant so that the hypotenuse side is the side surface, and the hypotenuse section is bent from the corner of the base to be parallel to the bottom. Or by sewing a base cloth of a flat portion obtained by overlapping the slanted portion so as to be slanted with the bottom portion and re-extending the slanted portion in the vertical direction in a convex curved shape with respect to the bottom corner portion. Occupant protection airbag characterized by 3. An airbag for protecting an occupant, wherein the pair of base fabrics according to claim 1 or 2 is an uncoated base fabric. 4. An airbag for protecting an occupant, wherein at least a part of outer peripheral portions of the pair of base fabrics according to claims 1, 2 and 3 are joined by a binding single-layered structure.