JPH0449010Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a reinforcing structure for an air bag body provided in an air bag device.

[Prior Art] This type of air bag body is generally made of cloth and has a rubber coating on its inner surface. As shown in Fig. 8, this air bag body has
Circular openings are formed at multiple locations by punching.

As shown in Figure 8, the fabric that makes up the air bag body is woven so that the warp and weft intersect, so the tension in the B and C directions is greater than that in the A direction, especially around the opening. It has the disadvantage that it has a tendency to be easily frayed from the periphery of the opening.

Therefore, it is common to combine annular reinforcing cloths around the opening in an overlapping manner to form a reinforcing structure.

However, since the reinforcing fabric is also manufactured by punching from the same fabric as the air bag body, the reinforcing fabric itself has the same properties against tension as described above, and it is difficult to achieve a sufficient reinforcing effect. Therefore,
Conventionally, in order to deal with this, the area of the reinforcing fabric was increased or multiple reinforcing fabrics were stacked on top of each other, which resulted in poor efficiency and increased weight of the airbag device.

It should be noted that the air bag body has other parts that require reinforcement in addition to the area around the opening, and the same reinforcement structure as described above is adopted for these parts as well.

[Problems to be Solved by the Invention] In view of the above, an object of the present invention is to provide an air bag reinforcing structure capable of efficiently reinforcing the reinforcement portions of the air bag.

[Means for Solving the Problems] In the airbag bag reinforcement structure according to the present invention, a cloth tape that can be bent in the width direction in an unloaded state is bent in the width direction and both longitudinal ends are connected to form an annular reinforcing cloth. Thus, the reinforcing fabric is bonded to the reinforced portion of the air bag body in an overlapping state.

[Function] In the present invention, which is the means described above, all the warp threads of the reinforcing cloth are arranged concentrically, so that the reinforcing cloth has a structure that is strong against tension in the radial direction at any part in the circumferential direction.

Therefore, the reinforcing effect is significantly increased compared to conventional reinforcing fabrics of the same area.

[Embodiment] FIG. 3 shows an air bag device equipped with an air bag body to which an embodiment of the present invention is applied.

In the air bag device 10, a base plate 14 is supported by a hub portion 12A of a steering wheel 12 via means not shown, and an air bag body 16, a cover 18, and an inflator 20 are attached to the base plate 14.

The air bag body 16 is stored in a folded state in a space formed between the base plate 14 and the cover 18, and the peripheral portion of the inflator mounting hole 44 is connected to the base plate 14 via a ring plate 22 fastened to the base plate 14. It is fixed in close contact with the The cover 18 is formed with a thin wall portion 24 at a portion facing the occupant, and is ruptured at the thin wall portion 24 when pressed by the expanding air bag body 16, thereby allowing the air bag body 16 to be expanded.

The inflator 20 passes through a through hole 26 bored in the center of the base plate 14 and an inflator mounting hole 44, and its upper end protrudes inward of the air bag body 16, and has a flange 27 provided in the middle.
It is fixed to the base plate 14 via.
The inflator 20 is filled with a gas generating substance,
A fuse is strung around the gas producing substance. The gas-generating substance is ignited via a fuse and starts burning, and the gas generated by the combustion is ejected from a number of openings 32 to inflate the airbag body 16. The fuse is ignited by a detonator connected to the starting end, and the detonator is struck by an ignition pin of a starting device activated by an acceleration of a predetermined value or higher, thereby igniting the fuse.

FIG. 4 shows the airbag body 16 in an exploded state. The air bag body 16 is formed into a bag shape by sewing an upper base 40 made of circularly cut cloth and a similar lower base 42 at their peripheral edges. The upper base 40 and the lower base 42 are coated with rubber on their inner surfaces to ensure the airtightness of the airbag body 16.
The lower base 42 has the large-diameter inflator mounting hole 44 opened in the center, and small-diameter exhaust holes 46 opened on both sides thereof.

A pair of straps 48 are arranged inside the airbag body 16. This strap 48
connects the central portion of the upper base 40 and the central portion of the lower base 42 to limit the amount of upward expansion of the upper base 40 in the drawing, thereby allowing the airbag body 16 to assume a predetermined expanded shape.
This strap 48 is connected to the upper base 40 and lower base 42 by stitching.

The connecting portion between the upper base 40 and the lower base 42 and the strap 48, and the exhaust hole 4
A reinforcing cloth 50 is disposed around the 6.

As shown in FIG. 1, the reinforcing cloth 50 is formed in an annular shape, and is manufactured by sewing together both longitudinal ends of a cloth tape 52 cut to a predetermined length. . As shown in FIG. 2, this cloth tape 52 has warp threads 54 of
The weaving shrinkage rate shown by the formula below is different between the end and the E end.
It has the property of curving so that the D end becomes convex under no load.

Weaving shrinkage rate = 1 - yarn length in woven state / yarn length before weaving In such a cloth tape 52, the tension of the warp yarns 54 is increased from the D end to the E end during the weaving stage. This can be obtained by decreasing the weave shrinkage rate.

It can also be obtained by weaving a fabric in which the shrinkage rate of the warp material gradually increases from the D end to the E end, and then thermally processing it. be able to.

Note that the radius of curvature R can be set to a desired dimension by setting the weaving shrinkage rate.

Each of the reinforcing cloths 50 is set to have an optimal width dimension, radius of curvature, etc. without waste, corresponding to the respective disposed portions.

As shown in detail in an exploded state in FIG. 5, the reinforcing cloth 50 for reinforcing the periphery of the exhaust hole 46 has an inner diameter approximately the same as that of the exhaust hole 46, and is arranged concentrically with the exhaust hole 46. , are connected to the inner surface of the lower base 42 by sewing or adhesive.

As shown in detail in the disassembled state in FIG. 6, the reinforcing cloth 50 that reinforces the joint between the strap 48 and the lower base 42 has an inner diameter that is aligned with the inflator mounting hole.
4, and is arranged concentrically with the inflator mounting hole 44, and also serves to reinforce the periphery of the inflator mounting hole 44. The pair of straps 48 are arranged so that their longitudinal ends contact the inner surface of the lower base 42 with their longitudinal ends separated by 90 degrees from each other around the inflator mounting hole 44 (the ends of each strap 48 are arranged at 180 degrees from each other). ), and the reinforcing cloth 50 is arranged so as to sandwich each end of these straps 48 with the lower base 42. These lower base 42, strap 48, and reinforcing cloth 50 are sewn together in a state in which they overlap.

Further, a small diameter bolt hole 56 is opened in the lower base 42 along the periphery of the inflator mounting hole 44, and a corresponding bolt hole 56 is opened in the reinforcing cloth 50.
is open. Similar bolt holes 5 are also provided in the base plate 14, ring plate 22, and flange 27 of the inflator 20 explained in FIG.
6 are formed, and bolts 58 are inserted into these bolt holes 56 and nuts 60 are screwed into the bolts 58.
As a result, the air bag body 16 and the inflator 20 are fixed to the base plate 14 as described above.

The strap 48 and the upper base 40 are shown in detail in an upside-down disassembled state in FIG.
The reinforcing cloth 50 that reinforces the joint with the upper base 40 has a pair of straps 48 that intersect at the center of the upper base 40.
The center portions are arranged so as to be aligned with the intersections so that the vicinity of each center portion in the longitudinal direction is sandwiched between the upper base 40. The upper base 40, the strap 48, and the reinforcing cloth 50 are sewn together in a state where they are overlapped.

Next, the operation of this embodiment will be explained.

When a vehicle equipped with the air bag device 10 is decelerated rapidly while traveling, the starter is activated to ignite the detonator, and the gas generated as described above is ejected into the air bag body 16. . As a result, the airbag body 16 starts to expand, breaks the cover 18 at the thin wall portion 24, bulges outward from the cover 18, and is deployed between the occupant and the steering wheel 12. At this time, a portion of the gas is discharged from the exhaust hole 46 to reduce the impact when the occupant hits the airbag body 16.

Due to the expansion of the air bag body 16, a large tension is applied to the upper base 40 and the lower base 42 due to the gas pressure that directly acts on them, and a force that tries to expand the diameters of the inflator attachment hole 44 and the exhaust hole 46 is applied. Since all the warp threads 54 are arranged concentrically and the tensile strength in the radial direction is large in any part of the circumference, sufficient reinforcement can be achieved even in a relatively small area. be effective.

In addition, the upper base 40 and the lower base 42 have a strap 4 attached to the connecting portion with the strap 48.
Although a large tension is exerted by the gas pressure acting indirectly through the reinforcing cloth 50 in these parts, the reinforcing cloth 50 has the same sufficient reinforcing effect as described above.

In this way, even if the reinforcing cloth 50 has a small area, it has a sufficient reinforcing effect, so that the weight of the air bag device 10 can be reduced, and especially when the air bag device 10 is attached to a steering wheel, it is possible to reduce the weight of the air bag device 10. bring about an effect.

Moreover, since the reinforcing cloth 50 is formed into a ring shape from the cloth tape 52, no cutoff portion is generated in the cloth tape 52, and the material yield is also improved.

[Effects of the Invention] As explained above, the airbag body reinforcing structure according to the present invention has the effect of efficiently reinforcing the reinforcement portion of the airbag body.

[Brief explanation of drawings]

Fig. 1 is a perspective view of a reinforcing cloth showing an embodiment of the air bag reinforcement structure according to the present invention, Fig. 2 is a partially enlarged plan view of Fig. 1, and Fig. 3 is an air bag to which this embodiment is applied. 4 is an exploded perspective view of the air bag body to which this embodiment is applied; FIGS. 5 to 7 are partially detailed exploded perspective views of FIG. 4; FIG. The figure is a plan view illustrating the woven structure of the airbag body. DESCRIPTION OF SYMBOLS 10... Air bag device, 16... Air bag bag body, 40... Upper base, 42... Lower base, 44... Inflator mounting hole, 46... Exhaust hole, 48... Strap, 50... Reinforcement cloth, 52
...cloth tape.

Claims (1)

[Scope of utility model registration request] A cloth tape that can be bent in the width direction under no load is bent in the width direction and both lengthwise ends are connected to form an annular reinforcing cloth, and the reinforcing cloth is joined to the reinforced part of the air bag body in an overlapping state. Airbag bag reinforced structure.