JPH0453321Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a strap attachment structure for a vehicle airbag that protects a passenger.

[Prior Art] A technique is known in which an airbag for protecting a passenger is attached to a steering wheel device or the like of a vehicle. This airbag is normally folded thinly, and when it becomes necessary to protect the passenger, it is inflated to a predetermined size by an expanding gas (for example,
Publication No. 23176, Special Publication No. 56-43890, Special Publication No. 1987
−41216, etc.).

In order to specify the size and shape of the air bag when it is inflated, especially the height of the air bag,
A structure is known in which a strap or rope made of a band-like body is provided to restrict the expansion of the air bag above a predetermined height.

Among these, the structure of an airbag provided with a strap has conventionally been constructed as shown in FIGS. 12 and 13, for example. In the figure, reference numeral 1 denotes the main body cloth of the airbag, which is normally folded and becomes the state shown in FIG. 12 when inflated. In order to define the inflation height of the airbag, a strap 2 made of, for example, nylon is provided. In the illustrated example, both ends of the strap 2 are fixed to the body cloth 1, and the folded strap 2 is expanded when the airbag is inflated, and the height of the airbag is regulated by the length between the two fixed parts of the strap 2. .

The folded strap 2 is attached to the main body cloth 1.
The strap 2 is stretched as the strap expands, but during this stretching, as shown by the arrow in FIG.
is strongly pulled left and right. Due to this deflection of the strap 2, the strap 2 becomes attached to the main body cloth 1 at the fixed part 3.
To prevent this from happening, a V-tape 4 is provided as an auxiliary fixing member at the fixing portion, as shown in FIG. 13. One side of the V-shaped V tape 4 is attached to the strap 2, and the other side is attached to the main body cloth 1.
The strap 2 is fixed to the body cloth 1 by adhesive, sewing, etc., and the strength of fixing the strap 2 to the main body cloth 1 is ensured by the V-tape 4. Conventionally, the shape of the portion of the V-tape 4 fixed to the strap 2 has been formed into a rectangular shape as shown in the figure.

[Problems to be Solved by the Invention] However, the strap attachment portion using the V-tape 4 as described above has the following problems.

That is, in FIG. 13, the area A where the V tape 4 is fixed to the strap 2 is a cross section of two strips of the strap 2 and the V tape 4, but the area B where the V tape 4 is not attached is the cross section of the strap 2. There is only one cross section. V tape 2 in range A
Since the shape of the strip is rectangular, the cross-sectional area of the strip changes rapidly along the line L. A sudden change in cross-sectional area is caused by the sudden change and the strap 2 in the vicinity.
This may cause stress concentration in the strap 2, leading to a corresponding decrease in the strength of the strap 2.

To compensate for this strength loss, strap 2
One possible method is to increase the width of the airbag, but increasing the width of strap 2 makes it more difficult to fold the strap and increases the bulk when folded. This goes against the general desire to keep it small.

The present invention focused on the above-mentioned problems with the conventional strap attachment part, and while ensuring the effect of improving the adhesion strength of the strap to the main body fabric using the V-tape, it also reduces the stress applied to the strap that may occur when the air bag is inflated. The purpose is to eliminate concentration and ensure sufficient strength of the strap without resorting to simply increasing the width of the strap.

[Means for Solving the Problems] The airbag strap mounting structure of the present invention, which meets this objective, includes a strap made of a foldable strip attached to the main body fabric of a vehicle airbag, which defines the height of the airbag when the airbag is inflated. The end of the strap is fixed to the main body cloth, and
In an airbag strap attachment structure in which a V-tape is made of a V-shaped short strip and one side of the V-shape is fixed to the strap and the other side is fixed to the main body fabric, at least the distal end side of the part of the V-tape that is fixed to the strap is The shape of the strap is such that the width of attachment to the strap gradually decreases from the main fabric side toward the strap extension direction.

[Function] In such a structure, the width of the V-tape gradually becomes narrower toward the distal end at the portion where it is fixed to the strap, and the cross-sectional area of the V-tape also gradually becomes smaller. Therefore, when the strap and the V-tape are viewed as a band-like body,
The cross-sectional area of the band-like body gradually decreases in the direction of strap extension, and after the V-tape tip there is only the strap. As a result, there is no sudden change in the cross-sectional area of the strip, and stress concentration is prevented from occurring. Since stress concentration does not occur, there is no need to consider special reinforcing measures that would be necessary if stress concentration occurs, and sufficient strength of the strap is ensured without increasing the width of the strap.

[Embodiments] Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.

1 and 2 show an airbag strap attachment structure according to an embodiment of the present invention. In the figure, numeral 11 indicates the entire air bag, and shows the state when it is inflated. Such an air bag 11, for example, as shown in FIG.
It is attached to the front side of the steering wheel device 12 of the vehicle. Further, although not shown in the drawings, it can also be attached to a passenger seat or a rear seat of a vehicle.

In FIG. 1, reference numeral 13 indicates the main body cloth of the air bag 11 made of nylon or the like, which inflates as shown in the figure when an inflation gas is sealed inside. A strap 14, which is made of a foldable band and defines the height of the air bag when it is inflated, is fixed to the inner surface of the main body cloth 13 by bonding, sewing, or the like. In this embodiment, both ends of the strap 14 are bent into an L shape and fixed to the main body cloth 13, respectively. It is also possible to fix the ends of the strap 14 to the main body cloth 13 by fixing only one end thereof to the main body cloth 13 and fixing the other end to a member other than the main body cloth 13. Strap 14 is also made of, for example, nylon.

The strap 14 and main body cloth 13 are normally folded, for example, as shown in FIG. 3, and are brought into the state shown in FIG. 1 only when inflation is required.

The part of the strap 14 that is fixed to the main body cloth 13 has a
As shown in FIG. 2, the V-tape 1 is made of a V-shaped short strip, and one side of the V shape is fixed to the strap 14, and the other side is fixed to the main body cloth 13.
5 is provided.

The shape of the part of the V-tape 15 that is fixed to the strap 14 is such that the distal end portion 15a is attached to the V-tape 15 from the main body cloth 13 side toward the strap 14 extension direction.
The fixation width is gradually reduced. In this embodiment, this portion 15a is formed into an isosceles triangle having an apex in the direction in which the strap 14 extends, and the portion 15b, which is closer to the main body cloth 13 than the portion 15a, has substantially the same width as the strap 14. has been done.

The shape of the portion of the V-tape that is fixed to the strap is not limited to the shape shown in FIG. 2, but can take various shapes, such as those shown in FIGS. 5 to 11, for example. All of these illustrated examples are also included within the scope of the present invention.

The V tape 21 shown in FIG.
The V-tape 31 shown in FIG. 6, in which a is formed in a semicircular arc shape, has its tip 31a branched into two and then gradually tapered, and the V-tape 41 shown in FIG. The tip portion 41a is formed into a trapezoidal shape. Also, the V tape 51 shown in FIG.
is formed in a shape that gradually narrows in width toward the distal end over the entire length of the portion 51a fixed to the strap 14. The V tape 61 shown in FIG.
Both sides of the tip 61a are curved. The V tape 71 and strap 72 shown in FIG. 10 have a wide root portion on the side that is fixed to the main body cloth, and the strap 72 is narrowed to a predetermined width from a position slightly away from the main body cloth. The tape 71 is formed so that its width gradually becomes narrower toward the tip end. Furthermore, the first
The V-tape 81 shown in FIG. 1 is formed such that its tip 81a is bifurcated, and each branch extends along both sides of the strap 14, and the width gradually becomes narrower toward the tip. There is. The shape of the V-tape to be adopted may be selected by considering the strength of the strap itself, the strength of the V-tape itself, the adhesion strength of each to the main fabric, the degree of force applied to the strap, etc.

The operation of the embodiment configured as described above will be explained mainly with reference to the shape examples shown in FIGS. 1 and 2.

In FIG. 2, in range C, the cross-sectional area of the band formed by the strap 14 and the V-tape 15 is equal to the cross-sectional area of the strap 14 and the V-tape 15.
In range D, one part of the strap 14 and the V tape 15
There are two parts with the strap added to the top, and the ratio of the part to the strap increases continuously as you move upward, and the cross-sectional area of the strap gradually decreases.
In range E, there is only one strap 14, but since the V-tape portion 15a in range D is triangular and its width becomes smaller as it approaches range E, the entire strap 14 is formed from range D to range E. There is no part where the cross-sectional area of the area changes rapidly.
Therefore, stress concentration on the strap 14 is avoided. Since the portion of the strap 14 that is fixed to the main body cloth 13 and the portion of the V tape 15 that is fixed to the main body cloth 13 are substantially the same as the conventional structure, the V tape 1
The effect of reinforcing the fixation of the strap 14 to the main body cloth 13 by the strap 5 is maintained as it is.

Furthermore, when the structure shown in FIG. 10 is adopted, the base portion of both the strap 72 and the V-tape 71, that is, the width of the fixation to the main body cloth is increased, thereby improving the fixation strength to the main body cloth. , the strap 72 is kept within a predetermined width, and stress concentration thereon is avoided. By keeping the strap 72 within a predetermined width, its foldability can also be maintained in a good condition.

[Effect of the invention] As explained above, when using the airbag strap attachment structure of the invention, the shape of the part of the V-tape that is fixed to the strap as a strap fixing reinforcing member is oriented from the main body fabric side to the strap extension direction. Since the fixing width gradually decreases in this direction, and there are no sudden changes in the cross-sectional area in this direction, it is possible to prevent stress concentration on the strap due to sudden changes in the cross-sectional area. The effect is that sufficient strap strength can be ensured without increasing the strap strength.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal cross-sectional view of an airbag according to an embodiment of the present invention, Fig. 2 is an enlarged perspective view of the strap fixing part of the device shown in Fig. 1, and Fig. 3 shows the airbag shown in Fig. 1 folded. FIG. 4 is a schematic side view showing an example of how the airbag shown in FIG. 1 is mounted on a vehicle; FIG. 5 is a perspective view of a strap fixing portion according to a different embodiment from FIG. 2; , FIG. 6 is a perspective view of a strap fixing part according to yet another embodiment, FIG. 7 is a perspective view of a strap fixing part according to still another embodiment, and FIG. 8 is a perspective view of a strap fixing part according to still another embodiment. Fig. 9 is a perspective view of a strap fixing part according to yet another embodiment;
0 is a perspective view of a strap fixing part according to yet another embodiment, FIG. 11 is a perspective view of a strap fixing part according to still another embodiment, FIG. 12 is a schematic vertical sectional view of a conventional airbag, and FIG. 12 is an enlarged perspective view of the strap fixing portion of the device shown in FIG. 12, and FIG. 14 is a schematic partial side view showing how force is applied to the strap. 1...Air bag, 13...Body cloth, 14,7
2...Strap, 15, 21, 31, 41, 5
1, 61, 71, 81...V tape.

Claims (1)

[Scope of utility model registration request] The end of a strap, which is a foldable band-shaped body and defines the height of the airbag when it is inflated, is fixed to the main body fabric of a vehicle airbag, and a short V-shaped strip is attached to the part of the strap that is fixed to the main body cloth. In a strap attachment structure for an air bag, the airbag has a V-shaped tape having one side of the V-shaped body attached to the strap and the other side attached to the main body fabric, in which the shape of at least the tip side of the part of the V-shaped tape fixed to the strap is fixed to the main body. A strap mounting structure for an airbag is characterized in that the strap is formed in a shape in which the width of attachment to the strap gradually decreases from the cloth side toward the strap extension direction.