JPH0490942A - Gas bag cover body - Google Patents

Abstract

PURPOSE:To prevent swell along a breaking groove thin portion at an automobile shock absorbing gas bag cover body, by providing plural joining portions at the breaking groove to form a continuous state, and forming second breaking grooves of a V-shape in the orthogonal direction to the breaking groove at joining portions to form a second thin portions. CONSTITUTION:At a breaking groove 41 which is formed in an H-shape at a cover body 35 flat plate portion 37, joining portions 46 which make the groove 41 discontinuous by joining integrally both side walls 45 of the groove 41, are formed at predetermined intervals. A second breaking groove 47 of a V-shape section is formed orthogonally to the groove 41 at each joining portion 46. Second thin portions 48, on account of these second grooves 47, are formed at joining portions 46 in crossing a thin portion 42 which is in parallel with a flat plate portion 37, and deformation in the direction of narrowing the groove 41, that is, in the direction of swelling up the cover body 35, can be restrained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Objective of the Invention] (Industrial Application Field) The present invention relates to a gas bag cover body for covering a gas bag for protecting occupants from impacts such as collisions in automobiles and the like.

(Prior Art) Gas bag devices for protecting occupants of automobiles and the like from shocks such as collisions are known.

As shown in Fig. 4, this gas bag device covers a gas bag 1 in a folded state with a cover body 2 made of soft synthetic resin, and causes gas to flow into the gas bag 1 and expand it due to an impact such as a collision. During the inflation, the cover body 2 is ruptured by the pressure of the gas bag 1, causing the gas bag 1 to protrude from the cover body 2. This protrusion of the gas bag 1 allows the occupant to touch the rim of the steering wheel. This protects the vehicle from colliding with the vehicle or the glass in front of it, and also absorbs the impact.

The cover body 2 includes, for example,
As shown in Publication No. 01862, cover body 2
By providing a breaking groove 3 in an H shape on the back surface of the gas bag 1, a thin wall portion 4 that is broken when the gas bag 1 expands is formed. The upper and lower sides of the cover body 4 are designed to open like doors when the gas bag 1 expands, and reinforcing nets 5 are insert-molded on both sides of the thin wall part 4, so that when the cover body 2 is broken,
This prevents breakage in parts other than the thin wall portion 4, and also prevents the cover body 2 from being broken into small pieces and scattered.

(Problem to be Solved by the Invention) By the way, even in a normal state, the cover body 2 of the gas bag 1 receives pressure from the folded gas bag 1, so the cover body 2 bulges around the thin wall portion 4. Since the bulge along the thin wall portion 4 tends to appear strongly, there is a problem in that it is visually unsightly and gives a sense of discomfort to the touch.

The present invention has been made in view of these points, and an object of the present invention is to prevent strong bulges from appearing along the thin portions of the cover body.

[Structure of the invention]

(Means for Solving the Problems) The present invention covers the gas bag 23 which is normally folded and expands due to the inflow of gas, and forms a tearing groove 41 on the back surface so that the gas bag 23 can be broken when the gas bag 23 expands. In the cover body 35 in which the thin wall portion 42 is formed,
The walls 45 on both sides of the breaking groove 41 are joined to form the breaking groove 41.
The gas bag 23 is formed by forming a plurality of joints 46 in a discontinuous state, and by forming second breaking grooves 47 on the side surfaces of the plurality of joints 46 in a direction intersecting the breaking grooves 41. Second thin wall portion 48 broken due to expansion
is formed in a direction intersecting the thin wall portion 42.

(Function) The cover body 35 of the gas bag 23 of the present invention is deformed in the direction in which the plurality of joints 46 become narrower (in other words, the fracture grooves 41 become narrower).
The thin wall portion 42 formed on the surface of the cover body 35 is prevented from deforming in the direction of swelling, and when the gas bag 23 is inflated, the second thin wall formed on each joint portion 46 together with the thin wall portion 42 formed on the surface of the cover body 35 Since the portion 48 is broken, it does not prevent the gas bag 23 from protruding from the cover body 35.

(Embodiment) An embodiment of the gas bag cover body of the present invention will be described with reference to the drawings.

FIG. 3 shows a boss portion 11 of an automobile steering wheel. Although not shown, this boss portion 11 is located at the center of an annular rim portion and is connected to the rim portion via a plurality of spokes. ing.

The boss portion 11 has a cylindrical boss 12 made of metal, and this boss 12 is fitted onto and fixed to the steering shaft of an automobile (not shown). A metal boss plate 13 is fixed by welding, and a gas bag device 14 is disposed above the boss plate 13.

This gas bag device 14 has a base plate 21 mounted on the boss plate I3 via a mounting means (not shown), and a circular opening 24 of the gas bag 23 on the periphery of the circular opening 22 of the base plate 21. The periphery of the annular fixing plate 25 and a plurality of rivets (not shown)
It is fixed with fixing tools such as screws.

In this gas bag device 14, a gas generator 30 is disposed in the opening 22 of the base plate 21, and a flange 31 on the outer periphery of the gas generator 30 is inserted into the opening 22 of the base plate 21. It is fixed under the periphery by the above-mentioned fixing device.

The gas bag 23 is arranged in a folded state, and the upper part of the gas generator 30 located inside the gas bag 23 is provided with a plurality of blow-off ports (not shown) for blowing out gas. .

Furthermore, in this gas bag device 14, a cover body 35 that covers the gas bag 23 is fixed to the outer peripheral edge of the base plate 21. This cover body 35 is made by integrally molding a cylindrical part 36 fixed to the base plate 21 and a flat plate part 37 that closes off the upper part of the cylindrical part 36 using a soft synthetic resin having elasticity such as urethane foam. be.

As shown in FIGS. 2 and 3, the back surface of the flat plate portion 37 of the cover body 35 has a fracture groove 4 having a roughly U-shaped cross section.
1 is formed in an H-shape in the left-right direction passing through the center of the flat plate part 37 and in the vertical (front-back) direction passing through both sides of the flat plate part 37.
An H-shaped thin wall portion 42 is formed on the surface of 7.

Then, as shown in FIG. 1, the wall portions 45 on both sides of the breaking groove 41 are integrally joined to the H-shaped breaking groove 41 formed in the flat plate portion 37 of the cover body 35. Breaking groove 41
A plurality of joints 46 are formed at predetermined intervals in a discontinuous state, and second fracture grooves 47 each having a roughly V-shaped cross section are formed on both sides of each of the plurality of joints 46. The fracture groove 41 parallel to the flat plate portion 37 of 35 (hereinafter referred to as the first
are formed in a direction perpendicular to the flat plate portion 37 of the cover body 35, intersecting with the fracture grooves 41 of the cover body 35. It is formed in a direction perpendicular to the flat plate part 37 of the cover body 35, intersecting the thin part 42 (hereinafter referred to as the first thin part 42) which is parallel to the flat plate part 37 of the cover body 35.

As shown in FIG. 2, reinforcing nets 51 are integrally embedded inside the cover body 35 by insert molding, located on both sides of the first thin walled portion 42 forming an H shape. There is.

With this configuration, in the event of a car collision, etc.
A shock sensor (not shown) is activated, and the gas generator 30
Gas is rapidly released into the gas bag 23 from the inside of the gas bag 23, and this gas causes the gas bag 23 to rapidly expand. The thin portion 42 and the second thin portion 48 perpendicular to the thin portion 42 are broken, and the H of the surface of the cover body 35 is cut.
The upper and lower (front and back) both sides of the central part of the first thin-walled part 42 forming a character shape open like doors, and the gas bag 23 protrudes from the cover body 35 and unfolds toward the driver. This prevents the driver from colliding with the steering wheel or the front glass, and also absorbs the impact in the event of a collision.

Furthermore, when the gas bag 23 is deployed, the reinforcing net 51
is the H-shaped first thin wall portion 42 on the surface of the cover body 35.
The character-11 shape is It is possible to reliably prevent breakage from occurring on the outside of the thin wall portion 42 of 1, and it is also possible to reliably prevent fragments from scattering at the time of breakage.

In a normal state, the cover body 35 receives pressure from the folded gas bag 23, but a plurality of joints 46 are formed on both sides of the first breaking groove 41 parallel to the flat plate part 37 of the cover body 35. Since the wall portions 45 are integrally joined, the plurality of joint portions 46 deform in the direction in which the first fracture groove 4I becomes narrower, that is, the first thin wall portion 42 swells on the surface of the cover body 35. By suppressing the deformation in the direction, it is possible to prevent a strong bulge from appearing on the cover body 35 along the first thin portion 42 .

In this embodiment, the cross section of the first rupture groove 41 formed in the flat plate part 37 of the cover body 35 in an H-shape parallel to the flat plate part 37 is shaped like an H-shape. It may also be shaped like a V-shape.

Further, in this embodiment, the cover body 35 is molded by inserting a reinforcing net 51 into a soft synthetic resin having elasticity such as urethane foam, but is not limited to this, and can be molded from a thermoplastic elastomer or the like. However, in this case, the reinforcing net 51 may not be used.

〔Effect of the invention〕

In the gas bag cover body of the present invention, the plurality of joints join the walls on both sides of the fracture groove parallel to the cover body.
These multiple joints suppress the deformation in the direction in which the fracture groove becomes narrower, that is, the deformation in the direction in which the thin-walled portion formed on the surface of the cover body swells, and thereby the surface of the cover body is prevented from deforming along the thin-walled portion. This can prevent a strong bulge from appearing, and when the gas bag is inflated, the thin wall part on the surface of the cover body and the second thin wall part at the joint that intersects with this will break, so the gas bag will separate from the cover body. It doesn't prevent you from standing out.

[Brief explanation of drawings]

Figures 1 to 3 show an embodiment of the cover body of the gas bag according to the present invention. FIG. 3 is a sectional view of a boss portion of a steering wheel equipped with a gas bag device, and FIG. 4 is a sectional view of a part of a cover body of a conventional gas bag. 23. Gas bag, 35. Cover body, 41. Breaking groove, 42. Thin wall portion, 45. Wall portion of breaking groove 41, 46.
Joint portion, 47...second fracture groove, 48...second thin wall portion. U order

Claims (1)

[Claims] (1) In a cover body that covers a gas bag that is normally folded and inflates due to the inflow of gas, and has a rupture groove on the back surface to form a thin part that is ruptured by the expansion of the gas bag, the above-mentioned rupture A plurality of joints are formed in which the walls on both sides of the groove are joined to make the fracture groove discontinuous, and a second fracture groove is formed on the side surface of the plurality of joints in a direction intersecting the fracture groove. A cover body for a gas bag, characterized in that a second thin-walled portion that is broken by expansion of the gas bag is formed in a direction intersecting the thin-walled portion.