JPH08164814A - Bag cover - Google Patents

Abstract

PURPOSE: To provide a bag cover capable of preventing the surface wall of a rupture groove part from rising to the surface and allowing decorative material to be laminated thereon. CONSTITUTION: A bag cover is formed of a surface wall 51 for partitioning off a space for storing an air bag, and a peripheral wall 52 to the surface wall 51, and has a rupture groove 56 ruptured when the air bag is expanded. The whole or part of the rupture groove 56 is provided at the peripheral wall 52.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air bag device for ensuring the safety of a driver and passengers from a collision caused by a car collision, and more particularly to a bag cover for accommodating an air bag.

[0002]

2. Description of the Related Art As a conventional airbag device 1,
As shown in FIG. 14, there is one that is attached to the steering wheel 5, has an inflator 2 and a gas suction port 17, is attached to the periphery of the inflator 2, and is a substantially circular airbag 3 that is inflatable and the inflator 2. This structure is provided with a storage case 4 for storing the airbag 3 and a retainer 6 for holding the storage case 4 in the center of the inside of the steering wheel 5.

The storage case 4 comprises a bag cover 11 for covering the airbag 3 and an insert 12 into which the inflator 2 is inserted while the bag cover 11 is fixed with rivets or the like. It is designed to break when deployed. Further, the airbag 3 is usually folded and housed in the storage case 4 so as to cover the inflator 2, and when a shock due to a collision accident occurs, the airbag 3 is rapidly supplied by the gas rapidly supplied from the inflator 2. Expands. Further, the attachment portion of the gas suction port 17 of the airbag 3 to the inflator 2 is sandwiched between the retainer ring 7 and the insert 12 to maintain airtightness, and together with the flange 2a and the retainer 6 around the inflator 2, the bolt 8 It is fastened together and installed. The airbag device 1 is arranged inside the boss 9 that forms a cavity in the center of the steering wheel 5, and the retainer 6 is fixed in the boss 9 via a nut 10 and a bolt (not shown). It is held in the center of the inside.

Next, the operation of the airbag device 1 having such a structure will be described. First, when a shock occurs due to a collision accident, a collision sensor (not shown) detects the collision and activates the inflator 2. Then, the high temperature gas flows out from the gas blowing hole 2b of the inflator 2, and the airbag 3
Breaks the bag cover 11 of the storage case 4 and expands rapidly. As a result, the airbag 3 serves as a cushioning material between the steering wheel 5 and the occupant, ensuring the safety of the driver from the impact of a collision accident.

By the way, in the conventional bag cover 11 of the airbag device 1 as described above, a breaking groove 13 which allows the airbag 3 to be deployed when the airbag 3 is inflated is formed on the back surface thereof as shown in FIG.
And as shown in (b). The breaking groove 13 is composed of a lateral breaking groove 14 provided at the center of the bag cover 11 and a vertical breaking groove 15 provided so as to intersect at both ends of the lateral breaking groove 14. Then, the bag cover 11 is ruptured from the lateral rupture groove 14 and the vertical rupture groove 15 by the pressure caused by the expansion of the airbag 3, and opens both sides.

[0006]

However, in the bag cover of the prior art, the lateral break groove and the vertical break groove are provided on the back surface of the front wall, and the bag cover is pushed up by the stored air bag. Due to the change, especially when the temperature becomes high, the fractured groove portion comes to rise to the surface side of the front wall, and as a result, there is a problem that the appearance of the surface of the bag cover deteriorates.

The back cover of the present invention has been made in order to solve this problem, and provides a back cover which prevents the surface wall of the fracture groove portion from protruding to the surface and which can be attached with a decorative material. The purpose is to

[0008]

In order to solve the above problems, in the back cover of the present invention, in claim 1,
In a bag cover having a front wall defining a space for accommodating an airbag and a peripheral wall for the front wall and having a break groove that breaks when the airbag is deployed, all or part of the break groove is the peripheral wall. It is provided in.

According to a second aspect of the present invention, in the first aspect,
A peripheral rupture groove extending in the circumferential direction is provided on the peripheral wall except for the hinge portion so that the peripheral wall can be opened with the hinge portion as a fulcrum.

[0010] In claim 3, according to claim 1,
The peripheral wall is provided with a circumferential breaking groove that extends in the circumferential direction except for hinge portions facing each other, and a lateral breaking groove that intersects the circumferential breaking groove is provided on the surface of the front wall and the circumferential wall as a design line as well. Both hinges can be opened with the hinge portions facing each other as fulcrums.

According to a fourth aspect of the present invention, as in the first aspect,
The peripheral wall is provided with a mounting portion that is connected to the inflator side of the airbag in the circumferential direction excluding the hinge portion,
A breaking groove is provided in the mounting portion so as to be separable from the peripheral wall, so that the hinge portion can be opened by one side.

A fifth aspect of the present invention is the second or fourth aspect of the invention, in which a decorative material is attached to the front wall.

[0013] In claim 6, according to claim 3,
On the surface wall, a decorative material divided with the lateral fracture groove as a boundary is attached.

According to a seventh aspect of the present invention, in each of the second to fifth aspects, the front wall is provided with a vertical rupture line connecting from the end of the front wall to facilitate bending of the hinge portion. is there.

[0015]

As described above, according to the bag cover of the present invention, the bag cover is broken based on the circumferential breaking groove provided in the circumferential wall or the circumferential breaking groove provided in the mounting portion of the circumferential wall, and the hinge portion is used as the fulcrum. Since it is possible to open the bag on one side, it is not necessary to provide a breaking groove on the front wall, and the front wall does not rise, so that the appearance of the bag cover is improved.

Further, the back cover is broken into two parts on the basis of the circumferential break groove provided on the peripheral wall of the back cover and the lateral break groove provided on the surface of the front wall and the peripheral wall and serving as a design line, and they are opposed to each other. Since it is possible to open both sides with the hinge part as a fulcrum, there is no protruding of the surface wall except for the lateral break groove formed, and since this horizontal break groove is also used as a design line, the bag cover looks Will get better.

Further, as described above, since the surface of the surface wall of the bag cover does not rise, it becomes possible to attach the decorative material to the surface of the surface wall, and the decorative material may be peeled off due to environmental changes or the like. Disappear.

[0018]

【Example】

Example 1 Hereinafter, regarding a bag cover that is Example 1 of the present invention,
This will be described with reference to the drawings.

FIG. 1 is a front perspective view of a bag cover according to the first embodiment, FIG. 2 is a rear perspective view of the bag cover according to the first embodiment, and FIG. 3A is a cross-sectional view of a main part of the bag cover according to the first embodiment. An enlarged view, FIG. 3B is an enlarged perspective view of a main part of the bag cover according to the first embodiment, and FIGS. 4A and 4B are diagrams of a bag cover in an airbag device equipped with the bag cover according to the first embodiment. FIG. 5 is a cross-sectional view showing a broken state, and FIG. 5 is an enlarged cross-sectional view showing a state in which a decoration material is attached to the front wall of the bag cover of the first embodiment. 1 to 5, the same reference numerals as those in FIGS. 14 and 15 shown in the related art have the same configuration, and thus detailed description thereof will be omitted.

In FIGS. 1 and 2, reference numeral 50 denotes a bag cover, which has a front wall 51, a peripheral wall 52 protruding from the vicinity of the outer periphery of the front wall 51, and a predetermined gap between the peripheral wall 52. A cover wall 53 that continuously projects from the outer periphery of the front wall 51 and projects in the same direction as the peripheral wall 52 is integrally formed, and a bent portion 54 that serves as a hinge is integrally formed on the upper portion of the peripheral wall 52. It is provided.

The peripheral wall 52 is provided with a plurality of mounting holes 55 at predetermined intervals in the circumferential direction, and the inner peripheral surface of the peripheral wall 52 is provided with a bent portion 54, except for a portion. A circumferential break groove 56 having a V-shaped cross section is formed so as to extend in the circumferential direction. Further, the bent portion 54 is also provided with a plurality of mounting holes 55.

Further, the peripheral wall 5 provided with the bent portion 54
As shown in FIG. 3A, a hinge groove 58 is formed on the back surface between the front wall 51 and the front wall 51 in the direction parallel to the bent portion 54. In addition, as shown in FIG. 3A, the inner peripheral surface of the peripheral wall 52 provided with the bent portion 54 is located closer to the front wall 51 side than the tip of the cover wall 53 and has a width between the bent portions 54. A bent portion 59 that is thin and extends over the entire length is provided.

Further, as shown in FIG. 3B, the cover wall 53 on the side of the peripheral wall 52 on which the bent portion 54 is provided is separated by a predetermined distance from each other at a position sandwiching the bent portion 54. Book break lines 60, 60 are provided, and the break lines 60,
60 extends from the tip of the cover wall 53 until it intersects with the hinge groove 58.

As shown in FIG. 4 (a), the bag cover 50 serves as a constituent member of the airbag apparatus 1 and has bolts 6 attached to mounting holes 55 provided in the peripheral wall 52 and the bent portion 54.
1 is inserted and the bolt 61 is screwed into the insert 12 to form the storage case 4 for storing the inflator 2, the airbag 3, etc., and the steering wheel 5
Attached to. Further, the cover wall 53 of the bag cover 50 is provided with a core cover 68 that comes into contact with the tip of the bag cover 50 and covers the storage case 4.

In the airbag apparatus 1 to which the bag cover 50 according to the first embodiment is attached, when a collision accident occurs, a collision sensor (not shown) detects the collision and operates the inflator 2. Then, the high temperature gas flows out from the gas blowing hole 2b of the inflator 2,
The airbag 3 inflates rapidly. As a result, the pressure due to the expansion of the airbag 3 acts on the bag cover 50, and the bag cover 50 is fractured from the circumferential fracture groove 56 formed in the circumferential wall 52, as shown in FIG.

As a result, the airbag 3 is brought into a free state, so that the airbag cover 50 on the rupture side continues to be inflated while being pressed. At this time, the rupture side bag cover 50 which receives the pressure due to the expansion of the airbag 3 has its cover wall 5
After 3 is broken from the breaking line 60, the bag cover 50 on the breaking side is formed with the hinge groove 58 and the bent portion 59 of the bent portion 54 as fulcrums.
Is folded in such a way that it opens one-sided, and finally, as shown in FIG. 4B, the airbag 3 projects outside the storage case 4 and inflates. As a result, the airbag 3 serves as a cushioning material between the steering wheel 5 and the occupant, ensuring the safety of the driver from the impact of a collision accident.

As described above, according to the bag cover 50 of the first embodiment, the circumferential break groove 5 formed in the circumferential wall 52.
Since the bag cover 50 is broken on the basis of 6 and the folding portion 54 can be opened one side with the fulcrum as a fulcrum, there is no need to provide a breaking groove in the front wall 51, and the front wall 51 does not protrude. 50 looks better. As a result,
As shown in FIG. 5, for example, a decorative material 70 such as genuine leather can be attached to the surface of the front wall 51 of the bag cover 50, and the decorative material 70 can be applied to the front wall 5 of the back cover 50.
It is possible to enhance the decorative effect on the surface side of the steering wheel 5 without being peeled off from the surface of the steering wheel 5.

Further, since the breaking line 60 is provided on the cover wall 53 of the back cover 50, only the circumferential breaking groove 56 and the bag cover portion broken from the breaking line 60 are bent, so that the bending is easy. The advantage is that the inflation of the airbag 3 is not suppressed.

Further, since the hinge groove 58 and the bent portion 59 are provided, the bag cover 50 which is pressed by the airbag 3 is broken and then the hinge groove 58 and the bent portion 59.
With this as a reference, the bag cover 50 can be easily folded in a single-opened state, and the bent portion 5
Since 9 is located on the front wall 51 side from the tip of the cover wall 53, it does not come into contact with the tip of the cover wall 53 or the core cover 68 provided between the cover wall 53 and the peripheral wall interferes. The bag cover 50 can be bent using the bent portion 59 as a fulcrum.

Example 2 Hereinafter, with respect to a bag cover which is Example 2 of the present invention,
This will be described with reference to the drawings.

FIG. 6 is a front perspective view of the bag cover of the second embodiment, FIG. 7 is a rear perspective view of the bag cover of the second embodiment, and FIGS. 8A and 8B are bag covers of the second embodiment. FIG. 9 is a cross-sectional view showing a broken state of the bag cover in the airbag device equipped with, and FIG. 9 is an enlarged cross-sectional view showing a state in which a decoration material is attached to the front wall of the bag cover of the second embodiment. Incidentally, in FIG. 6 to FIG. 8, FIG.
5 or the same reference numerals as those in FIGS. 14 and 15 shown in the related art have the same configurations, and thus detailed description thereof will be omitted.

In FIGS. 6 and 7, the bag cover 15 is shown.
In 0, a bent portion 54A (which serves as a hinge portion) similar to the bent portion 54 provided in the upper portion of the peripheral wall 52 below the peripheral wall 52 faces the bent portion 54 and is integrated. The hinge groove 58A is provided on the back surface between the peripheral wall 52 on which the bent portion 54A is provided and the front wall 51.
However, the bent portion 59 is formed on the peripheral wall 52 provided with the bent portion 54A.
A is provided in the same configuration as the hinge groove 58 and the bent portion 59 provided in the upper portion of the peripheral wall 52, respectively.

Further, the peripheral wall 52 provided with the bent portion 54A
The cover wall 53 is provided with break lines 60A and 60A at positions sandwiching the bent portion 54A as the same structure as that provided on the cover wall 53 on the bent portion 54 side. , 60A extend from the tip of the cover wall 53 to intersect the hinge groove 58A.

Further, on the surface of the front wall 51 and the peripheral wall 52 of the bag cover 150, a lateral fracture groove 65 which also serves as a design line is formed.
Are formed. The lateral fracture groove 65 is located at the center between the bent portions 54 and 545A and extends in the direction parallel to the bent portions 54, 54A until it intersects with the circumferential fracture groove 56.

As shown in FIG. 8 (a), the bag cover 50 serves as a constituent member of the airbag apparatus 1 and has mounting holes 55 formed in the peripheral wall 52 and the bent portions 54, 54A.
Insert the bolt 61 into the
By being screwed into the inflator 2 and the airbag 3,
It is attached to the steering wheel 5 while forming a storage case 4 for storing the like. Also, the bag cover 15
The cover wall 53 of No. 0 is provided with a core cover 68 that abuts on the tip and covers the storage case 4.

In the airbag apparatus 1 to which the back bar 150 according to the second embodiment is attached, when a collision due to a collision occurs, a collision sensor (not shown) detects the collision and activates the inflator 2. Then, the high temperature gas flows out from the gas blowing hole 2b of the inflator 2, and the airbag 3 is rapidly inflated. As a result, the pressure due to the expansion of the airbag 3 acts on the bag cover 150, and as shown in FIG.
The circumferential break groove 56 formed on the peripheral wall 52 and the front wall 51.
The transverse fracture groove 65 formed in the above is fractured in a state of being divided into two.

As a result, the airbag 3 is brought into a free state, so that the airbag cover 150 divided into two is continuously inflated while being pressed. At this time, in the two-divided bag cover 150 which is pressed by the expansion of the airbag 3, the cover wall 53 has break lines 60, 60 and 60A, 6A, 6A, 6B.
After breaking from 0A, the bag covers 150 are folded with the hinge grooves 58, 58A of the bent portions 54, 54A and the bent portions 59, 59A as fulcrums, and finally, the bag cover 150 is folded, as shown in FIG. ), As shown in FIG.
The airbag 3 projects from the gap ruptured at 5 to the outside of the storage case 4 and inflates. As a result, the airbag 3 serves as a cushioning material between the steering wheel 5 and the occupant, ensuring the safety of the driver from the impact of a collision accident.

As described above, according to the bag cover 150 of the second embodiment, the same effect as that of the first embodiment can be obtained, that is, the circumferential break groove 5 formed in the circumferential wall 52.
6 and a lateral fracture groove 65 formed in the front wall 51 and the peripheral wall 52.
Since the bag cover 150 is divided into two parts based on the above, and both sides can be opened by using the bent portions 54 and 54A as fulcrums, the front wall 51 other than the lateral break groove 65 is prevented from protruding, and Since the lateral fracture groove 51 is also used as a design line, the bag cover 150 looks good. As a result, as shown in FIG. 9, it is possible to attach a decorative material 70, such as a genuine leather, which is divided into two parts with the lateral fracture groove 65 as a boundary, to the front wall 51 of the bag cover 150. The material 70 is the front wall 51 of the back cover 50.
It is possible to enhance the decorative effect on the surface side of the steering wheel 5 without being peeled off from the surface of the steering wheel 5.

Further, the cover wall 53 of the bag cover 150.
Since the break lines 60, 60, 60A, 60A are provided in the peripheral break groove 56, the lateral break groove 65, and the break line 60,
Since only the bag cover portion broken from 60, 60A, 60A is bent, there is an advantage that the bending is easy and the inflation of the airbag 3 is not suppressed.

Further, the hinge grooves 58, 58A and the bent portion 5
9 and 59A are provided, the bag cover 150 that is pressed by the airbag 3 can be easily broken after breakage based on the hinge grooves 58 and 58A and the bent portions 59 and 59A. Can be bent with both sides open, and since the bent portions 59, 59A are located closer to the front wall 51 side than the tip of the cover wall 53,
Abutting on the tip of the cover wall 53 or the cover wall 53
The bag cover 150 can be bent around the bent portions 59 and 59A as a fulcrum without being obstructed by the core cover 68 provided between the inner wall and the peripheral wall.

Example 3 Hereinafter, with respect to a bag cover which is Example 3 of the present invention,
This will be described with reference to the drawings.

FIG. 10 is a front view of the bag cover of the third embodiment, FIG. 11 is a rear view of the bag cover of the third embodiment, FIG. 12 is a vertical sectional view of the bag cover of the third embodiment, and FIG. ) And (b) are cross-sectional views showing a broken state of the bag cover in the airbag apparatus equipped with the bag cover of the third embodiment, and FIG. 14 is a case where a decorative material is attached to the front wall of the bag cover of the third embodiment. It is an expanded sectional view showing the state. 10 to 14, the same reference numerals as those in FIGS. 1 to 5 of the first embodiment or FIGS. 14 and 15 shown in the related art have the same configurations, and thus detailed description thereof will be omitted. .

In FIGS. 10 to 12, reference numeral 250 denotes a bag cover, which has a substantially triangular front wall 251, a peripheral wall 252 which projects from the vicinity of the outer periphery of the front wall 251, and extends along the triangular shape. A thick cover wall 253 is integrally formed on the upper portion of the peripheral wall 252.
A bent portion 254 (hinge portion) having the same configuration as that of the first embodiment is integrally provided on the upper portion of the second wall 2, and the peripheral wall 252 having the bent portion 254 is provided.
The hinge groove 258 is provided on the back surface between the front wall 251 and the front wall 251, and the bent portion 259 is provided on the peripheral wall 252 provided with the bent portion 254.
However, the same configurations as those shown in the first embodiment [FIG.
The same configuration as that shown in (a)] is provided.

Further, the cover wall 253 provided with the bent portion 254 is provided with two breaking lines 260, 260 at a position sandwiching the bent portion 254 with a predetermined interval therebetween. The break lines 260, 260 extend from the tip of the cover wall 253 until they intersect the hinge groove 258.

Further, the peripheral wall 252 facing the bent portion 254.
The mounting groove 27 that penetrates inside and outside the peripheral wall 252
5 on the upper side of the peripheral wall 252.
Mounting groove 27 penetrating inside and outside of this peripheral wall so as to be parallel to
6, 278 are formed respectively. Each mounting groove 275
To 277, L-shaped mounting portions 278 are integrally formed so as to project in the same direction as the side on which the peripheral wall 252 projects and close the mounting grooves 275 to 277. Further, the attachment portion 278 of the attachment groove 275 is provided with a lateral fracture groove 280 having a V-shaped cross section extending in a direction parallel to the bent portion 254, and the attachment portion 278 of each of the attachment grooves 276 and 277 is provided with the bent portion 25.
4, vertical breaking grooves 285 and 285 each having a V-shaped cross section extending in a direction orthogonal to 4 are formed.
0 and the vertical break grooves 285, 285 for each mounting portion 275-27
7 is separable from the peripheral wall 252. A plurality of mounting holes 286 are formed in each mounting portion 278. An emblem 295 is integrally formed on the surface of the front wall 251.

This bag cover 250 is shown in FIG.
As shown in FIG. 3, as the constituent members of the airbag device 1, the mounting holes 5 provided in each mounting portion 278 and the bent portion 254 are mounted.
The bolt 61 is inserted into the Nos. 5, 286, and the bolt 61 is screwed into the insert 12 to be attached to the inflator 2. In addition, the cover wall 2 of the bag cover 250
A core cover 68 is provided on 53 to cover the storage case 4 by abutting the tip thereof.

In the airbag apparatus 1 to which the bag cover 250 according to the third embodiment is attached, when a collision due to a collision occurs, a collision sensor (not shown) detects the collision and activates the inflator 2. Then, the inflator 2 flows out the high temperature gas from the gas blowing hole 2b, and the airbag 3 is rapidly inflated. As a result, the pressure due to the expansion of the airbag 3 acts on the bag cover 250, and as shown in FIG.
0 breaks from the lateral break grooves 280 and the vertical break grooves 285, 285 formed in each attachment portion 278.

As a result, the airbag 3 is in a free state, so that the bag cover 250 on the fracture side is pressed and continues to expand. At this time, after the cover wall 253 is broken from the break lines 260 and 260, the bag cover 250 on the breaking side, which is pressed by the inflation of the airbag 3, fulcrums the hinge groove 258 and the bent portion 259 of the bent portion 254. Then, the bag cover 250 on the break side is folded in a single-opened state, and finally, as shown in FIG. 13B, the airbag 3 projects outside the storage case 4 and inflates. As a result, the safety of the driver is ensured from the impact of a collision accident.

As described above, according to the bag cover 250 of the third embodiment, the lateral fractured grooves 280, the vertical fractured grooves 285, 285 (the circumferential fractured grooves 29) formed in the respective mounting portions 278.
The bag cover 250 is broken based on 0) and the bent portion 25
Since the front wall 251 does not need to be provided with a rupture groove because the front wall 251 does not protrude, the bag cover 250 looks good and the surface of the steering wheel 5 can be opened. The decorative effect on the side can be enhanced. The front wall 2 around the emblem 295
The surface of 51 (the surface of the front wall 251 excluding the emblem 295) may be laminated with a decorative material such as genuine leather, and as described above, since the front wall 251 does not protrude, the real leather or the like Also, the decorative material of 1 does not peel off from the front wall 251.

In addition, the cover wall 25 of the bag cover 250
Since the fracture lines 260 and 260 are provided on the No. 3, the transverse fracture grooves 280, the longitudinal fracture grooves 285 and 285, and the fracture lines 260 and 2
Since only the bag cover portion broken from 60 is bent, there is an advantage that the bending is facilitated and the inflation of the airbag 3 is not suppressed.

Further, since the hinge groove 258 and the bent portion 259 are provided, the bag cover 250 which is pressed by the airbag 3 can be easily broken after being broken with the hinge groove 258 and the bent portion 259 as a reference. , This bag cover 250
You can fold it with one side open,
The bent portion 259 is formed from the tip of the cover wall 253 to the front wall 251.
Since it is located on the side, the bent portion 259 is used as a fulcrum without coming into contact with the tip of the cover wall 253 or being hindered by the cover wall 253 by the core cover 68 provided between the peripheral walls 252. The bag cover 250 can be folded.

[0052]

As described above, according to the bag cover of the present invention, the bag cover is broken on the basis of the circumferential breaking groove formed in the peripheral wall or the mounting portion of the peripheral wall, and the hinge part can be opened with the hinge portion as a fulcrum. Therefore, it is not necessary to provide a breaking groove in the front wall, and the front wall is prevented from protruding, so that the appearance of the bag cover is improved. As a result, the decorative material can be attached to the front wall of the bag cover, the decorative material does not peel off from the front wall of the back cover, and the decorative effect on the front surface side can be enhanced.

Further, a circumferential breaking groove formed on the circumferential wall,
Since the bag cover is broken into two parts based on the lateral break grooves formed on the front wall and the peripheral wall and both sides can be opened with the opposite hinge portions as fulcrums, the front wall other than the lateral break grooves is raised. Since this groove is eliminated and this lateral fracture groove is also used as a design line, the appearance of the bag cover is improved. As a result, it becomes possible to attach the decorative material divided into two parts with the lateral break groove as a boundary, to the front wall of the bag cover, and the decorative material does not peel off from the front wall of the back cover, and the decoration on the front surface side is prevented. The effect can be enhanced.

[Brief description of drawings]

FIG. 1 is a front perspective view of a back cover according to a first embodiment of the present invention.

FIG. 2 is a rear perspective view of the back cover according to the first embodiment of the present invention.

FIG. 3 is an enlarged view of a main part of the back cover according to the first embodiment of the present invention, in which (a) is an enlarged cross-sectional view of the main part of the back cover.
(B) is an enlarged perspective view of a main part of the back cover.

4A and 4B are cross-sectional views showing a broken state of the back cover in the airbag apparatus equipped with the back cover according to the first embodiment of the present invention.

FIG. 5 is a vertical cross-sectional view showing a state in which a decorative material is attached to the front wall of the back cover according to the first embodiment of the present invention.

FIG. 6 is a front perspective view of a back cover according to the second embodiment of the present invention.

FIG. 7 is a rear perspective view of the back cover according to the second embodiment of the present invention.

8A and 8B are cross-sectional views showing a broken state of the back cover in the airbag apparatus equipped with the back cover according to the second embodiment of the present invention.

FIG. 9 is a vertical cross-sectional view showing a state in which a decorative material is attached to the front wall of the back cover according to the second embodiment of the present invention.

FIG. 10 is a front view of the bag cover according to the third embodiment of the present invention.

FIG. 11 is a back view of the bag cover according to the third embodiment of the present invention.

FIG. 12 is a vertical sectional view of a bag cover according to a third embodiment of the present invention.

13 (a) and 13 (b) are cross-sectional views showing a broken state of the bag cover in the airbag device equipped with the bag cover according to the third embodiment of the present invention.

FIG. 14 is a vertical cross-sectional view showing a conventional airbag device.

FIG. 15 is a view showing a back cover of the prior art, (a)
Is a front view of the back cover, and (b) is a back view of the back cover.

[Explanation of symbols]

 3 Airbag 5 Steering wheel 50, 150, 250 Back cover 51, 25 1 Front wall 52, 252 Peripheral wall 54, 54A, 254 Bent part (part of peripheral wall) 56, 290 Circumferential fracture groove 65 Horizontal fracture groove 70 Decorative material

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Tomonori Koga 1764-1, Ueyoshi Yoshimihara, Chiyoda-cho, Shinji-gun, Ibaraki Sensor Technology Co., Ltd. Tsukuba Office

Claims (7)

[Claims] 1. A bag cover comprising a front wall defining a space for accommodating an airbag and a peripheral wall for the front wall, the break having a breaking groove that breaks when the airbag is deployed, all or one of the breaking grooves. A bag cover, wherein a part is provided on the peripheral wall. 2. The bag according to claim 1, wherein the peripheral wall is provided with a circumferential rupture groove extending in the circumferential direction except for the hinge portion, and the hinge portion can be opened one side with the hinge portion as a fulcrum. cover. 3. The peripheral wall is provided with a circumferential breaking groove extending in the circumferential direction except for hinge portions facing each other, and lateral breaking grooves intersecting with the circumferential breaking groove are designed on the surfaces of the front wall and the circumferential wall. 2. The bag cover according to claim 1, wherein the bag cover is provided as a line and can be opened with the hinge portions facing each other as fulcrums. 4. The peripheral wall is provided with a mounting portion that is connected to the inflator side of the airbag in the circumferential direction excluding the hinge portion, and the mounting portion is provided with a breaking groove that is separable from the peripheral wall. The bag cover according to claim 1, wherein the hinge portion can be opened singly using the hinge portion as a fulcrum. 5. The bag cover according to claim 2, wherein a decoration material is attached to the front wall. 6. The bag cover according to claim 3, wherein a decorative material divided with the lateral fracture groove as a boundary is attached to the front wall. 7. The bag cover according to each of claims 2 to 5, wherein the front wall is provided with a vertical rupture line connected from an end of the front wall to facilitate bending of the hinge portion.