JPH02200548A - Air bag structure for automobile - Google Patents

Abstract

PURPOSE:To prevent the peeling and scattering of a bag cover by forming a fragile section in a nearly H-shape with a horizontal fragile section extended in the horizontal direction and two vertical fragile sections provided on both the right and left end sections respectively and setting the rigidity at the end section of the fragile section higher than the rigidity at other portions of the fragile section. CONSTITUTION:When a car collides and an air bag device is operated and an air bag 21 is inflated, a thin section 40 formed between lateral grooves 41a and 41b on the front and the rear is ruptured by the expansion pressure, a bag cover 25 is vertically divided, thin sections formed between vertical grooves 42a and 42b and between 43a and 43b on the front and the rear are ruptured respectively, and the cover 25 is vertically opened. Only the grooves 42b and 43b on the rear side are provided at terminal sections of vertical fragile sections 42 and 43, the rigidity of terminal sections of the vertical fragile sections 42 and 43 is made higher than the rigidity of other portions within a fragile section 40, the bag cover 25 is prevented from being ruptured across the terminal sections of the vertical fragile sections 42 and 43 by the inertial force at the time of deployment, and the peeling and scattering of the cover 25 are effectively prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an airbag structure for an automobile, and more specifically, to a structure of a bag cover that covers the passenger side of an airbag.

[Prior Art] Conventionally, in automobile airbag devices, the passenger side of the airbag is covered with an integral cover (bag cover), and when the airbag inflates during a vehicle collision, the inflation pressure of the airbag is used to cover the passenger side of the airbag. It is generally well known that the bag cover is opened and the airbag is inflated and deployed from inside the cover toward the passenger.

In such an airbag device, the bag cover is usually provided with a groove (that is, a fragile portion), and when the airbag is inflated, the bag cover is torn open along the groove by the inflation pressure of the airbag. For example, in JP-A-63-184546, the bag cover has a substantially U-shaped groove formed by a horizontal groove extending in the horizontal direction and two vertical grooves provided at both ends of the horizontal groove. is disclosed. In a bag cover in which a substantially U-shaped groove is formed, normally, when the airbag expands, the bag cover is first broken along the horizontal groove and divided into upper and lower parts, and the divided upper and lower parts are separated. and are opened vertically along the longitudinal grooves.

[Problems to be Solved by the Invention] However, when the bag cover is opened as described above, the bag cover is further broken beyond the end of the groove due to the inertial force when the bag cover is expanded, and as a result, It is possible that the bag cover peeled off and was scattered towards the passenger side.

The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide an airbag structure for an automobile that can prevent the bag cover from peeling off and scattering when the airbag is deployed.

[Means for Solving the Problems] Therefore, in the present invention, a bag cover is disposed on the passenger side of the airbag, a fragile portion is formed in the bag cover, and when the airbag is inflated, the bag In an airbag device for an automobile, the cover is configured to be opened by breaking along the weakened portion, and the weakened portion includes a weakened portion extending in the lateral direction, and a weakened portion at both left and right ends of the lateral weakened portion. The two vertically weakened portions are formed into a shape of approximately 1-(, and the rigidity of the end of the weakened portion is set higher than the rigidity of other parts of the weakened portion. It is.

[Effects of the Invention] According to the present invention, among the weakened portions formed in a substantially H-shape, the rigidity of the end portions of the weakened portions is set higher than the rigidity of other portions of the weakened portion W. When the bag cover is opened due to expansion of the bag, it is possible to prevent the bag cover from being broken beyond the end of the fragile portion due to the inertial force at the time of expansion. As a result, it is possible to effectively prevent the cover from peeling off and scattering when the bag cover is deployed, thereby further improving the safety of the airbag device.

[Example] Hereinafter, an example of the present invention will be described in detail based on the accompanying drawings.

As shown in FIG. 6, the automobile 1 according to the present embodiment includes a plurality of front sensors 11 disposed near the front sensor 2 at the front end of the vehicle body, and a plurality of front sensors 11 disposed near the front sensor 2 at the front end of the vehicle body as collision detection means for detecting a collision of the vehicle. and a dash sensor 12 attached to the front dash panel 3, and each of these front sensors 11 and each dash sensor 12 is electrically connected to a control unit 13 disposed within the instrument panel 4. has been done. Each of the front sensors 11 and the dash sensor 12 is composed of, for example, a well-known G sensor.
．． . . , 11 have relatively low sensitivity, and when a collision occurs in the automobile 1, they sense this and turn on. On the other hand, the dash sensors 12 . . . . j2 has a relatively high sensitivity, and is turned ON when the impact force due to a collision is equal to or greater than a predetermined value.

On the other hand, as shown in FIG.
An airbag module 20 is installed in which the main components of the airbag device, such as a gas generator and an ignition device, are integrated into one assembly, and the airbag module 20 is electrically connected to the control unit 13. , the ignition device is activated by a command signal from the control unit 20.

In the above configuration, when a collision occurs in the automobile l, at least one of the plurality of front sensors 11 is activated.
When the N operation is activated and the dash sensor 12 is activated, the ignition device is activated by the command signal from the control unit 13, and gas is instantaneously generated in the gas generator, and the second in FIG. As shown by the dotted chain line, the airbag 21 is inflated and deployed toward the occupant M by this gas.

The above airbag module will be explained below.

As shown in FIGS. 2 and 3, the airbag module 20 is equipped with a gas generator 22 (inflator) that instantaneously generates gas by a reaction between a gas generating agent and a flame enhancer. The inflator is equipped with an igniter 23 (igniter) that generates heat and causes a reaction between the gas generating agent and the flame enhancer, and an air bag 21 that instantly inflates when filled with gas generated by the inflator 22. , these airbags 21. The main components of the airbag device, such as the inflator 22 and the igniter 23, are fixed to the base plate 24, and the passenger side is covered with a case 25 (bag cover) to form one assembly unit. base plate 2
The steering wheel 5 is fastened and fixed to the center hub of the steering wheel 5 by four mounting bolts 31 fixed to the lower surface of the steering wheel 5.

The bipedal inflator 22 is fastened and fixed to the base plate 24 by a plurality (for example, four sets) of ports 32a and nuts 32111, and an igniter 23 is disposed at the center thereof, and the generated gas is disposed at the side thereof. A large number of gas holes 22a are provided to release gas into the airbag 2I.
is provided. Further, the airbag 21 has its peripheral edge sandwiched between the retainer ring 33 and the base plate 24 and is fixed with a number of rivets 34, and is folded and stored inside the bag cover 25. . Furthermore, a harness 26 having a connector 27 attached to the tip thereof is connected to the igniter 23.
The harness 26 is connected to the control unit l-13 (+111 harness (not shown) via the connector 27).
It is designed to be connected to

The bag cover 25 is formed into a box shape with a substantially U-shaped cross section, and after storing the inflation flake 22, igniter 23, airbag 21, etc. fixed to the base plate 24, the lower end of the periphery is attached to the base plate 24. It is sandwiched between the upper and lower reinforcing plates 35, 35 and the left and right reinforcing plates 36, 36, and is fixed to the base plate 24 by a large number of rivets 371.

Furthermore, as shown in FIG. 1, the bag cover 25 has a horizontal groove 41a extending in the horizontal direction on the front side thereof;
Loop-shaped vertical grooves 42 provided at both left and right ends of the
On the other hand, on the back surface of the bag cover 25, as shown by the broken line in FIG. , 43a, and left and right vertical grooves 42b provided at both ends of the horizontal groove 41b and located directly below the outer portions of the vertical grooves 42a and 43a on the surface side. 43b is provided. That is, the bag cover 25 has 71! on the front and back sides. A horizontal weakened part 41 composed of $41a and 41b, a left vertical weakened part 42 composed of front and back grooves 42a and 4.2b, and a right vertical weakened part 43 composed of front and back grooves 43a and 43b. A substantially H-shaped weakened portion 40 is provided.

A sheet-like reinforcing material 25r made of, for example, synthetic fibers knitted into a mesh shape is embedded in the bag cover 25 along its curved shape (see FIG. 3), and the reinforcing material 25'
is arranged so as not to interfere with the groove 40, and acts as a core material that maintains the shape of the bag cover 25, and when the bag cover 25 is opened, the cover 2
5 from being crushed into small pieces and scattered.

Further, vertical walls 25e on both left and right sides of the bag cover 25,
The outer shape of the bag cover 25f' is set to have a substantially concave shape with the upper and lower ends protruding outward (see FIG. 1), thereby increasing its rigidity. When the bag cover 25 is opened, the bag cover 25 is easily pushed apart in the left and right direction, thereby preventing problems such as partial detachment from the base plate 24. Furthermore, the cross-sectional shape of the vertical wall of the bag cover is formed to become wider toward the attachment side to the base plate 24 (see FIG. 3), so that the airbag 21
A predetermined rigidity can be ensured while ensuring sufficient storage space for accommodating the inflation flakes 22 and the like.

When a collision occurs in the automobile 1 and the airbag device is activated and the airbag 21 is inflated, the inflation pressure of the airbag 21 causes the lateral grooves 41 on the front and back sides to
The thin wall portion 41c (see FIG. 3) formed between the front and back grooves 42a and 42b is broken and the bag cover 25 is divided into upper and lower halves, and the thin wall portion 41c (see FIG. 3) formed between the front and back vertical grooves 42a and 42b is broken.
The thin wall portions formed between the bag covers 25h and 3b are broken, respectively, so that the bag cover 25h can be opened vertically.In this embodiment, the vertical grooves 42a and 43a on the front side are formed in a loop shape, Since this loop portion can be opened left and right, the bag cover 25 can be opened not only vertically but also slightly horizontally, allowing the airbag 21 to be deployed smoothly. .

By the way, in this embodiment, when the bag cover 25 is opened, it is possible to prevent the bag cover 25 from further breaking beyond the end portions of the longitudinal weakened portions 42 and 43 and peeling off due to the inertial force during airbag deployment. In order to prevent
The rigidity of 2.43 is set higher than the rigidity of other parts of the fragile portion 40.

That is, as shown in detail in FIG. 4, the longitudinal weakened portion 4
2. At the end of 43, there is a groove 42b on the back side.

43b is provided, and no groove is formed on the surface side. Therefore, the longitudinal weakened portions 42 and 43 have higher rigidity at their distal ends than other portions of the weakened portion 40 and are less likely to break.

In addition, in this embodiment, only the grooves 41b on the back surface side are provided for both left and right end portions of the horizontally fragile portion 41, and >/4 is not formed on the front surface side, so that the rigidity of this portion is set high. has been done. For this reason, when the bag cover 25 breaks, it will receive resistance at this part, and the inertia force at the time of deployment will be taken away accordingly, and the vertical weakened parts 42, 43
This is designed to prevent excessive inertial force from acting when the material breaks.

As described above, according to the present embodiment, the rigidity of the end portions of the longitudinal weakened portions 42 and 43 of the weakened portion 40 formed in a substantially H-shape is determined by the rigidity of the other portions of the weakened portion 40. Since the height is set higher than the above, when the bag cover 25 is opened due to the inflation of the airbag 2I, the bag cover 25 is prevented from being broken beyond the end of the vertical weakened portion 42, 43 due to the inertial force at the time of expansion. This makes it possible to effectively prevent the bag cover 25 from peeling off and scattering, thereby further improving the safety of the airbag device.

In addition, although the above-mentioned embodiment was about the case where the groove part was provided on each of the front side and the back side of the bag cover 25, the groove part was provided only on either of the blade sides (for example, the front side). The same effects as in the above embodiments can also be achieved with respect to objects by adjusting the width, depth, etc. of the grooves (weak parts).

That is, to explain the vertically weakened part on the left as an example, as shown in FIG. By doing so, the rigidity of the distal end portion can be increased. Furthermore, as shown in FIG. 8, the width of the vertically weakened portions 62 and 63 is made approximately equal to the width of the horizontally weakened portion 6 in the central portion, and decreases as it approaches the distal end, thereby increasing the rigidity of the distal end. , can be made higher than other parts of the fragile portion 60. Furthermore, as shown in FIG. 9, only the end portions of the longitudinally weakened portions 72 and 73 are provided with intermittent grooves in the form of perforations instead of continuous grooves, thereby increasing the rigidity of this portion. It can also be made higher than other parts.

[Brief explanation of the drawing]

The drawings are for detailed explanation of the present invention.
Fig. 1 is a plan view of the bag cover, Fig. 2 is a plan view of the back side of the airbag module, Fig. 3 is a cross-sectional explanatory view taken along the line A-A in Fig. 2, and Fig. 4 is B in Fig. 1. 5 is a plan view of a steering wheel equipped with an airbag module, FIG. 6 is a side view of the front of a vehicle, and FIG. 7 is a bag according to a modification of the embodiment of the present invention. 8 and 9 are plan views of bag covers according to other modifications of the embodiments of the present invention, respectively. ! ...Automobile, 21...Airbag, 25...Bag cover, 40,60.70...Fragile part, 41,5
1,61... Lateral weak part, 42.52, 62.72...
・Vertical weak part (left side), 43.63.73...Vertical weak part (right side), M...Crew. Agent for patent applicant Tsuda Co., Ltd.

Claims (1)

[Claims] (1) A bag cover is provided on the passenger side of the airbag,
The bag cover has a fragile portion formed therein, and the bag cover is configured to break open along the fragile portion when the airbag is inflated. , is formed into a substantially H-shape by a horizontally weakened portion extending in the horizontal direction and two vertically weakened portions provided at both left and right ends of the horizontally weakened portion, and the rigidity of the end portion of the weakened portion is equal to that of the weakened portion. An automobile airbag structure characterized by having a rigidity higher than that of other parts.