JP3028524B2 - Airbag device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an airbag device for protecting an occupant by absorbing an impact generated at the time of a vehicle collision, and more particularly to an airbag device which is inflated by high-pressure gas from an inflator at the time of a vehicle collision. The present invention relates to an airbag device including an airbag for receiving an occupant moving forward.

2. Description of the Related Art In an emergency such as a vehicle collision, an airbag device provided in a vehicle body fixing portion in front of a seat of an automobile is discharged from an inflator fixed to the vehicle body fixing portion such as a steering or a lower part of an instrument panel. It expands instantaneously due to the pressure of the reaction gas, and has a crucial role in protecting occupants from being injured due to collision with the vehicle body.

As shown in FIG. 2, such an airbag device 01
For example, when the magnitude of the deceleration of the vehicle is equal to or greater than a certain magnitude, a gas generating agent is detonated by a collision signal from a collision detection sensor, and an inflator 02 that blows out gas, Fixed and inflator 02
And an airbag 03 that is inflated by gas ejected from the airbag. The airbag device 01 is attached to a vehicle body fixed portion such as a center portion of a steering wheel 04 or an instrument panel 05 in a state where the airbag 03 is folded and stored in a pad.

Then, as shown in FIG. 2, the gas generating agent in the inflator 02 reacts at the time of a vehicle collision, and the generated gas instantaneously inflates and deploys the airbag 30. As a result, the airbag 03 receives the occupant M moving forward due to inertia, and protects the occupant M from collision with the vehicle body.

By the way, among the airbags 03 in such an airbag device 01, the airbag 03 for the driver is, as shown in FIG. 3, for example, a substantially circular front side base cloth 03a attached to the inflator side and a driver. A substantially circular rear base cloth 03b arranged to face M is formed by sewing the outer peripheral edges of each other. In this case, each of these base fabrics 03a and 03b is formed of a single-layer woven fabric composed of a warp and a weft, and furthermore, the warp direction and the weft direction of the front base fabric 03a and the warp direction of the rear side 03b and The sutures are sewn so that the weft directions cross each other at an angle of approximately 45 °. When the warp direction and the weft direction of the front base cloth 03a and the rear base cloth 03b cross each other by approximately 45 °, the airbag 03
As a result, the vehicle expands in a round and uniform manner due to the inflation, so that the driver coming forward can be effectively received.

[Problems to be Solved by the Invention] However, in such an airbag 03,
When the airbag is inflated by the high-temperature reaction gas from the inflator 02, the reaction gas softens the coating agent applied to the base fabric, and a higher-temperature and higher-output reaction gas is generated due to the temperature dependence of the reaction gas. Will occur. When the coating material is softened and a high-output reactive gas is generated in this manner, a so-called opening phenomenon occurs in which the fabric structure is displaced at the sewn portion as shown in FIG. In this case, as shown in FIG. 5, the opening varies depending on the relative angle θ between the direction of the yarn of the woven fabric and the direction of the load applied to the base fabric. That is, the mesh is most frequently generated in the portion where the yarn direction of the woven fabric and the load direction applied to the base fabric coincide (0 ° and 90 °). As the base fabric expands and contracts due to elasticity, the number of openings decreases,
In particular, the opening amount is the smallest at a portion where the yarn direction and the load direction intersect at 45 °. Therefore, in the case of the airbag shown in FIG. 4, an aperture is formed near the seam of the base cloth on the side where the direction of the applied force and the direction of the thread coincide with each other.

Conventionally, in order to cope with such an opening phenomenon, the sewn portion is laid down with the base cloth over the entire circumference as shown in FIG. Measures such as attaching a thin film sealing tape 06 were taken.

However, such a countermeasure means increases the number of suturing work steps, tape attaching work steps, and the like, and all of them have problems that not only workability is not good but also costs are high. In addition, since the relatively thick sewn portion is further sewn or a tape is stuck to the sewn portion, the sewn portion is further thickened, and the space for folding and storing, that is, the package volume is large. There is also a problem that it becomes.

Therefore, as a result of further studies and studies on the tendency of the openings to occur, it has been found that the openings occur during the bag inflation process, and that the openings occur at specific portions due to the way in which the bag is folded. That is, if the up-down direction m and the left-right direction n of the airbag 03 are defined as the up-down direction and the left-right direction of the airbag in a state in which the airbag 03 is mounted on the vehicle, FIGS. As shown in the figure, generally, the airbag 03 is first folded in the vertical direction m from the upper or lower part, or folded in the left-right direction n from the left and right sides. Airbag 03
Is folded first in the vertical direction m,
The openings are concentrated on the upper and lower sewn portions in the vertical direction m, and when the airbag is folded forward in the left and right direction, the openings are on the left and right sides. It was found that this occurred concentratedly at the suture located at.

Therefore, as in the prior art, the seam is stitched over the entire circumference of the sewn portion to increase the absolute strength of the sewn portion, or a thin film sealing tape for preventing the passage of high-temperature gas from the opening is applied over the entire circumference of the sewn portion. If they were to wear them, they would have to take measures against apertures to the point where they were not so necessary, and it could not be said that aperture measures were being implemented efficiently.

The present invention has been made in view of such circumstances, and a purpose thereof is to suppress the occurrence of the opening phenomenon efficiently without requiring special work such as face-down sewing or sticking of a seal tape. It is an object of the present invention to provide an airbag device capable of performing the above.

Another object of the present invention is to provide an airbag device that can be made bulky even when the airbag is folded, and that can be manufactured at low cost.

[Means for Solving the Problems] In order to solve the above-mentioned problems, the invention of claim 1 comprises a first base fabric and a second base fabric formed of a woven fabric and stitched around each other, In the airbag device, wherein the folded airbag is inflated by high-pressure gas from an inflator, the first base fabric and the second base fabric have a woven fabric in which at least their stitching portions are both a single layer. And the first portion at the suture portion
The warp of the base cloth, the warp of the second base cloth, the weft of the first base cloth, and the weft of the second base cloth are respectively crossed with each other, and the first folding direction of the airbag is the same as that of the first base cloth. It is characterized in that it is folded so as to be inclined with respect to both the warp and the weft of each of the first and second base fabrics.

The invention according to claim 2 is characterized in that the airbag is mounted so that the direction of the first folding in the mounted state coincides with the vertical direction or the horizontal direction.

Further, the invention according to claim 3 is characterized in that an intersection angle between a warp of the first base cloth and a warp of the second base cloth at the stitching portion, and a weft of the first base cloth and a weft of the second base cloth. Are set to approximately 45 °, and the inclination angle between the first folding direction of the airbag and the warp and weft of each of the first and second base fabrics is about 22.5 °. It is characterized by being set.

[Operation] According to the airbag device of the present invention having such a configuration, at least the stitching portions of the first base fabric and the second base fabric are both formed of a single-layer woven fabric, and 1
The warp of the base cloth, the warp of the second base cloth, and the weft of the first base cloth and the weft of the second base cloth intersect with each other.
Moreover, in the portion most likely to be opened, that is, in the seam portion of the airbag base fabric located in the first folding direction, the initial folding direction and the warp and weft of each of the first and second base fabrics are combined. They become inclined to each other.
Therefore, even if a large load is applied to this portion during the inflation of the airbag, the openings are effectively suppressed by the elasticity of the fabric structure of the airbag base fabric.

In particular, according to the second aspect of the present invention, the opening is more effectively suppressed by attaching the airbag such that the direction of the first folding is coincident with the vertical direction or the horizontal direction.

In the invention according to claim 3, the crossing angle between the warp of the first base cloth and the warp of the second base cloth and the crossing angle of the weft of the first base cloth and the weft of the second base cloth at the stitching portion are determined. Since each of them is set to approximately 45 ° and the first airbag folding direction and the base fabric thread direction are inclined by about 22.5 °, the aperture can be more efficiently suppressed.

Embodiment An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a schematic view of an embodiment showing an installation direction of an airbag in an airbag device according to the present invention.

The airbag 1 used in this embodiment has a circular front-side (inflator mounting side) base fabric 1a and an outer peripheral shape similar to the front-side base fabric 1a as in the conventional airbag shown in FIG. The rear base fabric 1b having the shape is formed of a single-layer woven fabric, and is formed by sewing the entire circumference thereof. In this case, the warp and the weft of the front side base fabric 1a and the warp and the weft of the rear side base fabric 1b are sewn at an angle of approximately 45 ° with each other.

As shown in FIG. 1, in a state where the airbag 1 is mounted, the directions of the warp yarns and the weft yarns of the front side base fabric 1a are both upper and lower left and right directions m, n and 22.5.
。It is set to incline. On the other hand, rear side fabric 1b
Similarly, the respective directions of the warp yarn and the weft yarn are also set so as to be inclined by 22.5 ° with both the vertical directions m and n of the airbag 1.

The airbag 1 is set and attached as described above, and furthermore, as shown in FIGS. 8A and 8B, the pad is first folded from the vertical direction m or folded from the horizontal direction n. Is stored inside.

In the airbag apparatus according to the present embodiment having the above-described configuration, for example, when a reaction gas is ejected by operation of an inflator at the time of a vehicle collision or the like, the airbag 1 is inflated. In this case, since the first folding direction of the airbag 1 is any one of the vertical direction m and the horizontal direction n, the openings are formed at the sewn portions located in the vertical direction m or the horizontal direction n. It happens concentrated. That is, when the airbag 1 is inflated, a large force is applied to the airbag 1 in those directions. However, since the yarn directions of the base fabrics 1a and 1b are inclined by 22.5 ° with respect to those directions, the applied force can be effectively absorbed by the elasticity of the woven fabric. Moreover, since such a force is applied approximately evenly to the respective warp and weft yarns of both base fabrics 1a, 1b, the apertures can be applied to both base fabrics 1a, 1b.
The distribution is almost evenly distributed to b, and the opening amount is extremely small. That is, the openings are efficiently suppressed.

In the above-described embodiment, the warp and the weft of each of the base fabrics 1a and 1b are both inclined at an angle of 22.5 ° in the vertical direction or the horizontal direction of the airbag 1. It is not necessarily limited to this,
Each fabric 1 against the first folding direction of the airbag 1
The angle between the warp and the weft and the vertical direction m or the horizontal direction n of the airbag 1 may be any angle as long as both the warp and the weft of a and 1b are inclined by 22.5 °. In addition, each base cloth is
The angle between the warp and the weft of each of 1a and 1 is not limited to 22.5 ° and may be another angle. However, in order to evenly disperse the openings in both base cloths 1a and 1b, it is almost 22.
It is desirable to set the angle to 5 °.

[Effects of the Invention] As is clear from the above description, according to the airbag device of the present invention, the warp yarn of the first base cloth at the stitched portion of the first and second base cloths both composed of a single-layer woven cloth. And the warp yarns of the second base fabric, the weft yarns of the first base fabric and the weft yarns of the second base fabric intersect with each other, and the portion of the airbag base fabric most likely to be opened, that is, the airbag base fabric located in the first folding direction. Since the warp yarn and the weft yarn of each of the first and second base fabrics are set so as to be inclined with respect to the first folding direction at the sewn portion, the openings can be efficiently suppressed.

This eliminates the necessity of adopting a conventional opening preventing means such as face-down sewing or sticking of a sealing tape, so that the number of working steps can be greatly reduced and the number of parts can be reduced. In addition, since the suturing portion does not become thick, it is not bulky even when folded, and the effect of reducing the package volume can be obtained.

[Brief description of the drawings]

FIG. 1 is a view showing an installation direction of an embodiment of an airbag in an airbag apparatus according to the present invention, FIG. 2 is a view showing a general airbag apparatus arranged in an automobile, FIG. 3 (A) and (B) show a conventional airbag, FIG.
FIG. 5 is a diagram partially showing an opening formed at a seam portion of an airbag base fabric, FIG. 5 is a diagram showing an opening amount with respect to an angle between a load direction and a yarn direction of the base fabric, and FIG. FIG. 7 is a view showing another conventional aperture preventing means, and FIG. 8 is a view for explaining a folding direction of the airbag. 1 ... airbag, 1a ... front side fabric, 1b ... rear side fabric

Continuation of the front page (56) References JP-A-64-41437 (JP, A) JP-A-58-49541 (JP, A) Jpn.

Claims (3)

(57) [Claims] A first base fabric and a second base fabric formed of a woven fabric and sewn around each other, so that a folded airbag is inflated by high-pressure gas from an inflator. In the airbag device, the first base fabric and the second base fabric have at least their stitching portions both made of a single-layer woven fabric,
The warp yarn of the first base fabric, the warp yarn of the second base fabric, and the weft yarn of the first base fabric and the weft yarn of the second base fabric at the sewn portion intersect with each other, and the airbag comprises: An airbag device wherein the first folding direction is folded so that the first folding direction is inclined with respect to each of the warp yarn and the weft yarn of the first and second base fabrics. 2. The airbag device according to claim 1, wherein the airbag is mounted such that the direction of the first folding in the mounted state coincides with the vertical direction or the horizontal direction. 3. An intersection angle between a warp of the first base cloth and a warp of the second base cloth and an intersection angle of a weft of the first base cloth and a weft of the second base cloth at the stitching portion. Each is set to approximately 45 °, and the inclination angle between the first folding direction of the airbag and the respective warp and weft yarns of the first and second base fabrics is set to approximately 22.5 °. The airbag device according to claim 1 or 2, wherein: