Assembly structure of airbag case

Disclosed herein is an assembly structure of an airbag case that is capable of adjustably assembling an airbag case to an instrument panel considering assembly tolerance. The structure comprises an airbag case for accommodating an airbag and an inflator supplying a high-pressure gas to the airbag when a collision occurs, brackets formed at the airbag case and attached to a cowl cross member by means of bolts, and pins formed at the airbag case. The pins are inserted into pinholes formed at an instrument panel, respectively, for fixing the airbag case to the instrument panel. Around the pinholes are formed cut lines so that the pins are movable when assembly tolerance between the pins and the corresponding pinholes is created. With the assembly structure of the airbag case according to the present invention, coupling positions between brackets of the airbag case and the cowl cross member exactly correspond to each other by simply moving the airbag case when the brackets are attached to the cowl cross member by means of bolts, whereby poor assembly due to tolerance is prevented.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an airbag device of a vehicle for protecting a passenger in the vehicle when a collision occurs, and more particularly to an assembly structure of an airbag case that is capable of adjustably assembling an airbag case to an instrument panel considering assembly tolerance.

2. Description of the Related Art

As shown inFIG. 1, a conventional airbag device for vehicles generally comprises: an airbag case2mounted to an instrument panel; an airbag (not shown) accommodated in the front part of the airbag case2; an inflator (not shown) mounted to the rear part of the airbag case2for supplying a high-pressure gas to the airbag so that the airbag is expanded when a collision occurs; and an impact sensor for sensing a collision of a vehicle, whereby the airbag is expanded toward a passenger in the vehicle when the collision occurs to absorb kinetic energy from the passenger and thus protect the passenger from injury.

The airbag case2comprises: a cushion housing1for accommodating the airbag; and a can housing3attached to the rear part of the cushion housing1for accommodating the inflator.

At the cushion housing1is formed a flange10, which is attached to the instrument panel by means of a bolt. At the can housing3are formed brackets12, which are attached to a cowl cross member by means of bolts, respectively, while hanging on the cowl cross member.

In the above-mentioned conventional art, however, positions and shapes of the coupling part between the flange10and the instrument panel and of the coupling parts between the brackets12and the cowl cross member are fixed, whereby it is difficult to assemble the airbag case2due to tolerance when the flange10and the instrument panel are connected with each other by means of the bolt and when the brackets12and the cowl cross member are connected with each other by means of the bolts.

Of course, the flange10and the brackets12are designed considering the tolerance. However, the assembly tolerance between the flange10and the instrument panel and the assembly tolerance between the brackets12and the cowl cross member affect each other. As a result, the tolerance of the parts to be secondly assembled becomes high to the extent that the parts to be secondly assembled cannot be connected to each other after the parts to be firstly assembled are connected to each other by means of the bolt or the bolts, which leads to a high rate of poor assembly.

SUMMARY OF THE INVENTION

Therefore, the present invention has been made in view of the above problems, and it is an object of the present invention to provide an assembly structure of an airbag case wherein coupling parts between the airbag case and the instrument panel and between the airbag case and the cowl cross member are adjustably designed, whereby poor assembly due to tolerance is prevented.

In accordance with one aspect of the present invention, the above and other objects can be accomplished by the provision of an assembly structure of an airbag case, comprising: an airbag, an inflator for supplying a high-pressure gas to the airbag when a collision occurs, and an airbag case for accommodating the airbag, the inflator being mounted in the airbag case; an instrument panel and a cowl cross member mounted to the body of a car; brackets formed at the airbag case and attached to the cowl cross member; pins for fixing the airbag case to the instrument panel; and cut lines formed around pinholes so that the pins are movable when assembly tolerance between the pins and the corresponding pinholes is created, the pins being inserted through the pinholes, respectively.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

An assembly structure of an airbag case according to a preferred embodiment of the present invention will now be described with reference to the accompanying drawings.

FIG. 2is an exploded perspective view showing an assembly structure of an airbag case according to a preferred embodiment of the present invention,FIG. 3is a view showing a pin of the present invention inserted into a pinhole, andFIG. 4is a perspective view showing the airbag case of the present invention assembled with a retainer.

The assembly structure of the airbag case of the present invention comprises: an airbag case50for accommodating an airbag and an inflator; brackets52formed at the airbag case and attached to a cowl cross member by means of bolts; pins54formed at the airbag case50, the pins54being inserted into pinholes61formed at an instrument panel, respectively, for fixing the airbag case50to the instrument panel; and cut lines62formed around the pinholes61so that the pins54are movable when assembly tolerance between the pins54and the corresponding pinholes61is created.

The airbag case50comprises: a cushion housing51for accommodating the airbag; and a can housing53attached to the cushion housing51in a line for accommodating the inflator. At the cushion housing51are vertically formed the pins54, by which the cushion housing51is coupled with the instrument panel. At the can housing53are formed the brackets52, by which the can housing53is coupled with the cowl cross member.

The pins54are arranged in parallel with the instrument panel. To the instrument panel is mounted a retainer60, which is opposite to side surfaces of the cushion housing51and has the pinholes61and the cut lines62formed at the positions corresponding to the pins54, respectively.

The retainer60is formed in the shape of a rectangular band so that the retainer60surrounds the side surfaces of the cushion housing51. The width W1of the retainer60is larger than the width W2of the cushion housing51and smaller than the distance W3, which is the sum of the width W2of the cushion housing51and the length54L of each of the pins54, so that the pins54are inserted into the pinholes61, respectively. Preferably, the retainer60is made of a plastic material with a prescribed elastic force so that the cushion housing can be easily inserted into the retainer60.

The pins54are provided at both longitudinal sides51A of the cushion housing51. For example, four pins are provided at either side of the cushion housing51. Consequently, the distance W3, which is the sum of the width W2of the cushion housing51and the length54L of each of the pins54, corresponds to the distance between pins opposite to each other about the cushion housing51. The width W1of the retainer60is smaller than the distance between pins opposite to each other about the cushion housing51.

With the retainer60is integrally formed a flange63, which is provided at the end of the retainer60close to the instrument panel so that the flange63makes contact with the instrument panel. The flange63is formed in the shape of a rectangular band, which is vertically bent from the end of the retainer60toward the inside of the retainer60. The flange63has rivet coupling holes64, through which the flange63is coupled with the instrument panel.

The pins54are vertically protruded from the longitudinal sides51A of the cushion housing51toward the retainer60. Each of the pins54comprises a pole54A having a diameter smaller than the inner diameter of each of the pinholes61, and a stopper54B formed at one end of the pole54A. The stopper54B has a size larger than the inner diameter of each of the pinholes61. The stopper54B is preferably formed in the shape of a sphere so that the stopper54B is easily inserted through the corresponding pinhole61by virtue of the cut lines62. Consequently, the stopper54B makes rolling contact with the circumference of the corresponding pinhole61. The radius of the stopper54B is smaller than a distance L from the center of the pinhole61and one end of each of the cut lines62.

When the pin54is inserted through the corresponding pinhole61as shown inFIG. 3, the circumference of the pinhole61is elastically bent by means of the stopper54B in the direction in which the pin54is inserted. As a result, the pinhole61is expanded so that the stopper54B is inserted through the pinhole61. When the stopper54B is completely inserted through the pinhole61as shown in ‘A’ ofFIG. 4, the circumference of the pinhole61is elastically restored. As a result, the stopper54B is caught in the pinhole61, by which the separation of the pin54from the pinhole61is prevented, and thus the cushion housing51is securely attached to the retainer60.

The cut lines62are formed around the pinhole61at an angle of 90 degrees. The cut lines62are formed in the shape of a cross so that the cut lines62are radially arranged around the pinhole61while being uniformly spaced apart from each other. In other words, the cut lines62are formed in the shape of slits, respectively, which are outwardly extended from the pinhole61.

The assembly operation of the airbag case with the above-stated construction according to the preferred embodiment of the present invention will now be described.

First, the retainer60is attached to the instrument panel by means of rivets R, and then the airbag case50is fitted into the retainer60, as shown inFIG. 2. Consequently, the airbag case50is attached to the instrument panel as shown inFIG. 4.

At this time, the retainer60is elastically deformed so that the airbag case50is fitted into the retainer60while the pins54are not caught by the retainer60.

When the airbag case54is completely fitted in the retainer60, the pins54and the pinholes61are positioned in a line so that the stoppers54B of the pins54are outwardly protruded from the retainer60through the corresponding pinholes61, respectively. Consequently, the airbag case50is securely fixed to the retainer60.

Next, the brackets52are put on the cowl cross member in such a manner that coupling positions between the brackets52and the cowl cross member correspond to each other.

The coupling positions between the brackets52and the cowl cross member may not correspond to each other due to tolerance. In this case, it is possible to move the airbag case so that the coupling positions between the brackets52and the cowl cross member correspond exactly to each other since the cut lines62are formed around the pinholes61and thus the pins54can be outwardly moved from the pinholes in four directions.

Finally, when the brackets52are attached to the cowl cross member by means of the bolts while the coupling positions between the brackets52and the cowl cross member exactly correspond to each other, the airbag case50is securely supported by the instrument panel and the cowl cross member. In this way, the assembly operation of the airbag case50is completed.

As apparent from the above description, the present invention provides an assembly structure of an airbag case wherein pinholes are formed at an instrument panel, pins inserted through the pinholes are formed at an airbag case, and cut lines are formed around the pinholes so that coupling positions between brackets of the airbag case and a cowl cross member exactly correspond to each other by simply moving the airbag case when the brackets are attached to the cowl cross member by means of bolts, whereby poor assembly due to tolerance is prevented. Also, efficiency of the assembly between the brackets and the cowl cross member is increased since the coupling positions between the brackets of the airbag case and the cowl cross member always correspond to each other.

Furthermore, replacement of an airbag device is accomplished by simply pulling a used airbag case out of the instrument panel and then pushing a new airbag case into the instrument panel without necessity of disassembling a retainer from the instrument panel, whereby maintenance efficiency is increased.