JPH11165605A - Air belt device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance the restraining performance of an occupant by contracting a webbing when an air belt device is actuated, and thereby generating a sufficient tension in the webbing without using a pretensioner. SOLUTION: A webbing 5 capable of being drawn out of a retractor 3 is composed of a wrap belt 8 and a shoulder belt 9, and the shoulder belt 9 is composed of a rubber bag 10 capable of being inflated by a high pressure gas generated by an inflator 4 and a cloth cover 11 covering its outside. The cover 11 is formed from warps consisting of shape memory fibers stretching in the longitudinal direction and wefts positioned across the warps, and when the bag 10 is inflated by the high pressure gas supplied from the inflator 4 at collision of the vehicle, the warps of the cover 11 covering the bag 10 contract to the shape stored in memory with the heat of the high pressure gas, and thereby the dimension in longitudinal direction of the cover 11 is decreased, and the tension of the shoulder belt 9 is increased.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a webbing for restraining an occupant to a seat at the time of a collision of a vehicle, a tubular bag which can be inflated into a tubular shape by high-pressure gas supplied from an inflator, and a cover for the outer periphery of the bag. And a cloth cover for supporting the tension acting on the webbing.

[0002]

2. Description of the Related Art An air belt device which accommodates a bag inside a webbing of a seat belt and inflates the bag when a vehicle collides to softly restrain an occupant is already known, for example, from JP-A-6-56001. .

[0003]

By the way, in order to prevent the webbing of the seat belt from restricting the movement of the occupant during normal times other than the time of a vehicle collision, the webbing can be freely pulled out of the retractor. . When inertia is applied to the occupant's body due to a vehicle collision, the occupant's body cannot be restrained if the webbing can be freely pulled out from the retractor, so the webbing is forcibly retracted and locked. A pretensioner is provided on the retractor.

In an air belt device in which the webbing itself can be inflated, even if the retractor is not provided with a pretensioner, the webbing expands and the longitudinal dimension of the webbing shrinks with the expansion of the webbing. By simply locking the webbing so that it cannot be pulled out at the time of collision, a certain amount of tension can be generated in the webbing. However, the tension generated by the expansion of the webbing is not always sufficient compared to the tension generated by the pretensioner.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned circumstances, and by contracting a webbing when an air belt device is operated, sufficient tension is generated in the webbing without using a pretensioner, thereby improving the occupant restraint performance. The purpose is to:

[0006]

In order to achieve the above object, according to the first aspect of the present invention, a webbing for restraining an occupant to a seat at the time of a collision of a vehicle is formed into a cylindrical shape by a high-pressure gas supplied from an inflator. In an air belt device comprising an inflatable bag and a cloth cover for covering the outer periphery of the bag and supporting the tension acting on the webbing, a warp extending in the longitudinal direction of the cover is a high-pressure gas generated by an inflator. It is characterized by comprising heat-shrinkable fibers that shrink by heat.

According to the above construction, when the bag is inflated by the high-pressure gas supplied from the inflator at the time of a collision of the vehicle, the warp of the cover covering the bag contracts due to the heat of the high-pressure gas and the longitudinal dimension of the webbing is reduced. To decrease,
Tension is generated in the webbing, and the occupant restraint performance is enhanced.

According to a second aspect of the present invention, in addition to the configuration of the first aspect, the heat-shrinkable fiber is a shape memory fiber, and shrinks to a shape stored in advance by the heat of the high-pressure gas generated by the inflator. It is characterized by the following.

According to the above configuration, when the heat of the high-pressure gas acts on the warp made of the shape memory fiber, the warp shrinks to a shape stored in advance, thereby reducing the longitudinal dimension of the webbing.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described based on embodiments of the present invention shown in the accompanying drawings.

1 to 11 show an embodiment of the present invention. FIG. 1 is a side view of a front seat portion of a vehicle, FIG. 2 is a view taken in the direction of arrow 2 in FIG. 1, and FIG. 4 is an enlarged sectional view taken along line 4-4 of FIG. 3, FIG. 5 is an enlarged sectional view taken along line 5-5 of FIG. 3, FIG. 6 is an enlarged view of a portion 6 of FIG. 3, and FIG.
8 is a sectional view taken along line 8-8 in FIG. 6, FIG. 9 is an explanatory view corresponding to FIG. 6, FIG. 10 is an explanatory view corresponding to FIG. 7, and FIG. 11 is a corresponding view in FIG. FIG.

As shown in FIG. 1 to FIG.
The retractor 3 is provided below the center pillar 2, the inflator 4 is provided above the center pillar 2, the webbing 5 having both ends supported by the retractor 3 and the inflator 4, 5 includes a tongue 6 slidably supported at an intermediate portion of the seat 5 and a buckle 7 provided on a base portion of the seat 1 and to which the tongue 6 is detachably connected.

The known retractor 3 winds up one end of the webbing 5 so that the webbing 5 can be pulled out. When the mechanical acceleration sensor does not detect acceleration exceeding a predetermined value, the webbing 5 can be pulled out and the body of the occupant can be pulled out. When the mechanical acceleration sensor detects an acceleration equal to or more than a predetermined value at the time of a vehicle collision, the webbing 5 is locked so as not to be pulled out and restrains the occupant. The known inflator 4 ignites when the acceleration sensor detects acceleration equal to or higher than a predetermined value, and generates high-pressure gas by combustion of the propellant.

The webbing 5 is formed by integrally connecting a lap belt 8 between the retractor 3 and the tongue 6, and a shoulder belt 9 between the tongue 6 and the inflator 4.
The lap belt 8 is composed of a plain synthetic fiber plain belt, while the shoulder belt 9 is, as shown in FIGS. 3 to 5, a folded bag 10 made of urethane rubber or silicon rubber, and covers the outside thereof. The cover 11 is sewn at a sewing portion 12 (see FIG. 5) along the longitudinal direction of the shoulder belt 9. Inflator 4 provided above center pillar 2
A shoulder anchor 14 is rotatably supported by the gas outlet 13 of the above. The hollow shoulder anchor 14 also serves as a gas passage, and the upper ends of the bag 10 and the cover 11 are fixed to the lower end of the shoulder anchor 14. FIG. 5 shows an enlarged dimension of the shoulder belt 9 in the thickness direction, and the actual thickness of the shoulder belt 9 is smaller than that shown in the figure.

As shown in FIGS. 6 to 8, the cover 11 covering the bag 10 has a warp 15 extending in the longitudinal direction of the shoulder belt 9 and a direction perpendicular to the warp 15 (ie, the circle of the shoulder belt 9). Weft 16 extending in the circumferential direction)
…. The warp yarn 15 is made of a shape memory fiber and extends substantially linearly during normal times when the air belt device is not operating (see FIG. 7). On the other hand, the weft yarns are made of ordinary fibers that are not shape memory fibers, and normally pass between the warp yarns 15 with sufficient slack when the air belt device is not operating (see FIG. 8).

Next, the operation of the embodiment of the present invention having the above-described configuration will be described.

When the acceleration sensor detects an acceleration equal to or higher than a predetermined value due to a collision of the vehicle, the inflator 4 ignites to generate high-pressure gas, and the generated high-pressure gas is supplied to the bag 10 stored inside the shoulder belt 9. Then, the bag 10 expands inside the cover 11 by the pressure. When the pressure at which the bag 10 expands acts on the inner surface of the cover 11, the slacked weft threads 16 are stretched from the state of FIG. 8 to the state of FIG. 11, so that the diameter of the cover 11 increases and the expansion of the bag 10 increases. Permissible. When the shoulder belt 9 expands in this way, the contact area with the occupant's chest increases compared to the shoulder belt 9 before expansion, so that the occupant can be restrained more softly.

When a high-temperature gas is supplied into the bag 10, the heat is transmitted to the cover 11 through the bag, and the temperature of the cover 11 rises. When the temperature of the cover 11 exceeds the critical temperature, the warp 15 made of shape memory fiber
Are restored to the original shape stored in advance, and the shape changes from the substantially linear state shown in FIG. 7 to the bent state shown in FIG. As a result, the longitudinal dimension of the cover 11 shrinks, an effect equivalent to that of the pretensioner is exerted, the tension of the shoulder belt 9 increases, and the occupant restraint performance is further enhanced.

As described above, according to the air belt device of the present embodiment, when the bag 10 is inflated, the longitudinal dimension of the cover 11 contracts and the tension of the shoulder belt 9 is increased, so that the pretensioner is incorporated in the retractor 3. Without this, the same effect as the pretensioner can be obtained. In addition, since the length of the shoulder belt 9 in the longitudinal direction can be reduced by using the heat of the high-pressure gas generated by the inflator 4, the cost can be reduced as compared with the case where a pretensioner is used.

Although the embodiments of the present invention have been described in detail above, various design changes can be made in the present invention without departing from the gist thereof.

For example, instead of using shape memory fibers whose shape is changed by heat as the warp yarns 15, the same operation and effect can be obtained by using fibers whose length shrinks by heat. In the embodiment, the shoulder belt 9 is expanded, but both the shoulder belt 9 and the lap belt 8 may be expanded. In the embodiment, the inflator 4 is provided on the center pillar 2.
It is also possible to supply the high pressure gas to the bag 10 through the inside of the buckle 7 and the tongue 8 by providing the base 10 with the high pressure gas.

[0022]

As described above, according to the first aspect of the present invention, when the bag is inflated by the high-pressure gas supplied from the inflator at the time of collision of the vehicle, the warp of the cover covering the bag is formed by the high-pressure gas. As a result, the webbing shrinks and the longitudinal dimension of the webbing is reduced, so that tension is generated in the webbing and the occupant restraint performance is enhanced.

According to the invention described in claim 2,
When the heat of the high-pressure gas acts on the warp made of the shape memory fiber, the warp shrinks to a previously stored shape, thereby reducing the longitudinal dimension of the webbing.

[Brief description of the drawings]

FIG. 1 is a side view of a front seat portion of a vehicle.

FIG. 2 is a view in the direction of arrows in FIG. 1;

FIG. 3 is a perspective view of the occupant restraint device.

FIG. 4 is an enlarged sectional view taken along line 4-4 in FIG. 3;

FIG. 5 is an enlarged sectional view taken along line 5-5 of FIG. 3;

FIG. 6 is an enlarged view of part 6 of FIG.

FIG. 7 is a sectional view taken along line 7-7 of FIG. 6;

8 is a sectional view taken along line 8-8 in FIG. 6;

FIG. 9 is an operation explanatory view corresponding to FIG. 6;

FIG. 10 is an operation explanatory view corresponding to FIG. 7;

11 is an operation explanatory view corresponding to FIG. 8;

[Explanation of symbols]

 1 Sheet 4 Inflator 5 Webbing 10 Bag 11 Cover 15 Warp

Claims (2)

[Claims] A webbing (5) for restraining an occupant to a seat (1) at the time of a collision of a vehicle is provided with a bag (1) which can be inflated into a cylindrical shape by high-pressure gas supplied from an inflator (4).
0) and a cloth cover (11) covering the outer periphery of the bag (10) and supporting the tension acting on the webbing (5).
The warp (15) extending in the longitudinal direction of the cover (11).
An air belt device comprising heat-shrinkable fibers that shrink by the heat of the high-pressure gas generated by the inflator (4). 2. The air belt device according to claim 1, wherein the heat-shrinkable fiber is a shape memory fiber, and shrinks to a shape stored in advance by heat of the high-pressure gas generated by the inflator (4).