JP2002012113A - Air bag device for automobile - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an air bag device for front passenger seat by providing a nearly rectangular reinforcing rib on the back face of the rapture opening section provided in an instrument panel cover and fixing the reinforcing plate materials developing through their respective hinge sections for giving a highly safe characteristic to the rapture face of the edge section of the rapture opening section. SOLUTION: In the air bag device 1 for front passenger seat the reinforcing rib 12 having a rectangular cross section in the horizontal direction and extending downward is projected on the back face side of the rapture opening section 30 of the instrument panel cover, and engagement holes 14 are provided in front of the reinforcing rib 12 and in a rear side wall 12a (in the longitudinal direction) at specified spaces respectively, and the hook sections 36 fixed in the engagement holes 14 in front of an air bag case 5 and a rear side end face 5b (in the longitudinal direction) are locked through a mounting sections 35 extended downward from the hinge sections 34 of the reinforcing plate materials 33, and the right and left side walls 12b of the reinforcing rib 12 are separated a specified distance from the right and left side end faces 5c of the air bag case respectively, and the rapture groove 30a of the rapture opening section 30 is formed between the separated sections.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle airbag device for protecting passengers in a passenger seat and a driver's seat from frontal and side collisions at the time of a collision of a vehicle such as an automobile, and ensuring safety. The present invention relates to an improvement in the structure of a break opening portion formed in an interior cover for inflating and deploying an air bag.

[0002]

2. Description of the Related Art An airbag device for a passenger seat, a driver's seat, and right and left pillars applied to a vehicle such as an automobile basically includes an airbag and an airbag for accommodating the airbag in a folded state. The vehicle includes a bag case and an inflator for inflating and deploying the airbag, and is configured to be covered by a vehicle interior cover. The interior cover of an automobile is generally constituted by a panel-shaped instrument cover (hereinafter referred to as an interior cover) made of a synthetic resin such as polypropylene which covers the surface of a panel core integrally formed of a synthetic resin material such as polypropylene. I have.

A passenger airbag device 1 having a conventional structure.
As shown in FIGS. 1 and 2, the airbag 4 is disposed on the horizontal surface 3a of the interior cover 3 near the front window 1a of the automobile and the airbag 4 that is inflated and deployed by gas from the inflator is folded. It is provided with an airbag case 5 having an opening 5a at a location facing the back surface of the interior cover 3 and accommodating the opening 5a of the case 5 of the interior cover 3. An opening lid 6 formed of a flexible synthetic resin is disposed in an opening 3 b formed in the interior cover 3, and the opening lid 6 is attached to the opening lid 6 when the airbag 4 is inflated and deployed.
Has been proposed which is divided into two parts by grooves 6a and 6b formed in the center and the periphery thereof, separated in the front-rear direction, and opened.

[0004] On the back side of the open lid 6, mounting legs 7 having a rectangular cross section with a horizontal cross section having a slightly larger outer periphery in accordance with the opening 5a of the case 5 by integral molding are provided. A plurality of engaging pieces 8 are provided on the opening edge of the opening 3b formed in the cover 3 so as to elastically engage with the opening edge. A plurality of engaging pieces 8 penetrate the front and rear wall surfaces 7a and 7b of the mounting leg 7. A square hole 7c is formed, and
When attaching to the opening 3b formed in the interior cover 3, the front and rear wall surfaces 5b, 5b of the case 5
And a plurality of hooks 9 fixed to the hooks. When the airbag 4 is inflated and deployed, the airbag 4 is divided and separated in the front-rear direction from the grooves 6a and 6b formed at the periphery and the center of the open lid 6, and in the open state, the front and rear of the mounting leg 7 are provided. The plurality of square holes 7c of the wall surfaces 7a, 7b are engaged with the hook portions 9 fixed to the front and rear wall surfaces 5b, 5b of the opening 5a of the case 5 to prevent the open lid 6 from scattering. It has become.

However, in the airbag device for a passenger seat as shown in FIG. 1, an opening 3b is formed in the interior cover 3 at a position corresponding to the opening 5a of the airbag case 5, and the opening 3b is formed. 3b, a separate open lid 6 made of a flexible resin material different from the interior cover 3 is provided, which is troublesome to manufacture, and the open lid 6 is simple against external pressure. In addition, there is a problem that the appearance of the interior cover 3 is impaired, the design effect is reduced, and the production and mounting work is troublesome. Further, a lid reinforcing member for reinforcing the open lid 6 is not attached to the back side of the open lid 6 having the separate structure, and when the airbag 4 is inflated and deployed, the mounting legs of the open lid 6 are not attached. The engagement between the portion 7 and the hook portions 9 fixed to the front and rear wall surfaces 5b, 5b of the opening 5a of the airbag case 5 is easy to come off because of the flexible resin material, and the opening lid 6 is scattered. Can be considered.

[0006] Therefore, in order to solve the above-mentioned problems, the present applicant has previously disclosed in Japanese Patent Application No. 2000-20238 (filed on January 28, 2000) an interior cover that does not use the separate open lid. Has proposed a seamless type airbag device for the passenger seat where no opening line appears on the surface of the vehicle.

FIG. 3 is a partially enlarged explanatory view showing a state in which a rupture opening portion 30 for inflating and deploying the air bag is formed on the single-plate-shaped interior cover 3 of the passenger-seat air bag device, and FIG. 5 is an explanatory view showing the interior panel 3 with the break open portion 30 removed, and FIG. 6 is an enlarged sectional view taken along the arrow C in FIG. In FIGS. 3 and 4, a laser generated in a pulse form from a laser generating means (not shown) is applied to the inner cover 3 from the back surface side of the inner cover 3 to the outer edges of the reinforcing plate members 10a, 10a fixed to the back surface. By irradiating while traversing relative to each other, breakage grooves 30a and 30b are formed in which a through-hole penetrating the interior cover 3 is formed in a dashed line or a dotted line.
A rupture opening 30 for inflating and deploying the airbag corresponding to the size of the opening 5a of the airbag case 5 is formed. Further, the break opening portion 30 is split and separated into a double-opening when the airbag is inflated and deployed, and is opened by a break groove 30b formed in the longitudinal direction.

When the airbag is inflated and deployed, the break open portion 30 of the interior cover 3 is cut off from the interior cover 3 by the airbag 4. Plate 1
0a and 10a are fixed at one end to a horizontal surface by welding or the like, and the other end is connected to the back surface of the interior cover 3 by a hinge portion 1a.
By suspending through a pair of reinforcing ribs 12 formed at positions having an interval width slightly larger than the shape width of the opening 5a of the airbag case 5, When the airbag is inflated and deployed, the break open portion 30 of the interior cover 3 which is opened in a double-clicked manner is not scattered, so that the impact of the occupant at the time of vehicle collision is reduced, and the break open portion 3 is opened.
In order to prevent the danger caused by a bruise or the like caused by a blow, the present invention provides an improved air bag device for an automobile having the above-mentioned conventional separately provided open lid 6. Reference numeral 13 denotes a thin-walled portion formed on the rear surface connecting portion of the interior cover 3 of the pair of reinforcing ribs 12 so as to be broken and separated from the break-open portion 30 of the interior cover 3 which is opened when the airbag is inflated and deployed. It was done.

In the vehicle airbag device configured as described above, when a vehicle collides, the impact force at the time of the collision is detected by a sensor, and the impact force detected by the sensor is equal to or greater than a predetermined value. Is determined by a control device including a CPU or the like, and when it is determined that the value is equal to or greater than a set value, a predetermined gas is generated by operating an inflator by a signal output from the control device, and this gas is supplied to an airbag. The supply causes the airbag to inflate and deploy rapidly. That is, when the break open portion 30 of the interior cover 3 is pressed from the inside by the pressure due to the air bag being inflated and deployed, the break open portion 30 is broken into the break grooves 30a, 30.
b, and is separated from the interior cover 3, and the separated opening portion 30 is separated from the reinforcing plate 10.
The interior cover 3 is opened outward from the interior cover 3 with the respective hinge portions 11 of a and 10a serving as fulcrums. At the same time, airbag 4
Is inflated and deployed outward from the interior cover 3 from the opened break opening portion 30, and the cushioning action of the inflated and deployed airbag causes the passenger, driver's seat, and the occupant's chest, head, or left and right side columns to move. By supporting the arms and legs, the occupant is protected from the impact of a vehicle collision.

[0010]

By the way, the break opening portion 30 of the improved interior cover 3 is provided with a break groove 30 which penetrates perpendicularly from the back side to the front side of the interior cover 3.
a, 30b are formed and the reinforcing plate members 10a, 10a bent by the hinge portion 11 along the left and right longitudinal directions of the break open portion 30 are respectively welded and fixed, and the other ends of the reinforcing plate members 10a, 10a are welded. The portions are locked by a pair of reinforcing ribs 12, 12 before and after projecting in the left-right longitudinal direction of the break-open portion 30 of the interior cover 3, respectively. Although there is no fractured surface in the front and rear fracture grooves 30a in the left and right longitudinal directions and the fractured part of the central fracture groove 30b of the fracture opening part 30, there is no fracture surface that may cause a problem in the fracture shape. ,
Since the break portion of the right break groove 30a does not have the reinforcing ribs 12, 12 and the hinge portions of the reinforcing plate members 10a, 10a, the break portion in the short direction before and after the break open portion 30 is weak in structure, and the broken surface of the break portion is weak. Under severe weather conditions in which the temperature inside the car is -35 ° C in winter and 75 ° C in summer, shear forces act as shown in FIG. There is a problem that deformation such as the formation of 3c occurs and lacks safety.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned conventional problems, and an object of the present invention is to provide a reinforcing rib having a rectangular horizontal cross section on the back surface of an interior cover so as to correspond to an airbag opening. Vehicles equipped with a highly safe break-opening part by making it difficult to form a sharp edge in the break-open part, especially in the left, right front, and rear short-side break parts. It is an object to provide an airbag device for use.

[0012]

According to one aspect of the present invention, there is provided a vehicle having at least one of a front portion, a center portion of a steering wheel, and a side pillar portion covered by a vehicle interior cover. Arranged, while accommodating the airbag that is inflated and deployed by the gas from the inflator in a folded state, an airbag case having an opening at a location facing the back surface of the interior cover is arranged,
An airbag for an automobile, comprising: a rupture-opening portion having a fragile portion formed by a rupture groove at a back surface position of the cover opposite to the opening of the airbag case; and a reinforcing plate material having a shape corresponding to the rupture-opening portion. In the device, a reinforcing rib having a rectangular horizontal section extending downwardly on the back side of the break open portion of the interior cover is projected, and engagement holes formed at predetermined intervals in front and rear side walls (longitudinal direction) of the reinforcing rib. A hook portion fixed to the engagement hole on the front and rear end surfaces (longitudinal direction) of the airbag case via an attachment portion extending downward from a hinge portion of the reinforcing plate material, And the left and right walls of the reinforcing rib are connected to the left of the airbag case,
It is characterized in that it is separated from the right side end surface by a predetermined distance, and a break groove of a break open portion is formed between the separated portions.

According to a second aspect of the present invention, in the vehicle airbag device according to the first aspect, the distance between the left and right side walls of the reinforcing rib and the inner surfaces of the left and right ends of the airbag case is 10 mm to 40 mm. In addition, the distance between the left and right ends of the reinforcing plate was set to 5 mm to 30 mm, and the breaking groove formed in the breaking open portion was formed at a position separated from the left and right side walls of the reinforcing rib by 5 mm to 20 mm. It is characterized by the following.

According to a third aspect of the present invention, in the airbag apparatus for an automobile according to the first or second aspect, the breaking groove is provided with a pulsed laser generated from a laser generating means from the back side of the interior cover. Along the contour in the left-right longitudinal direction of the break open part, and in the front and rear short direction, irradiate while relatively moving to a position separated by a predetermined distance to form a thick part and a thin part on the back surface of the interior cover at a predetermined distance. It is characterized by comprising.

[0015]

Next, an embodiment of the present invention will be described with reference to the drawings. FIG. 7 is a perspective view of a main part of an airbag device applied to a passenger seat, showing an embodiment of an airbag device for a vehicle according to the present invention, and FIG.
FIG. 9 is a partial plan view of an interior cover in which a passenger airbag device of the automotive airbag device according to the present invention is disposed, and FIG. FIG. 10 is a sectional view taken along the line DD of FIG. 7, and FIG.
It is an expanded sectional view of arrow E part.

In FIGS. 7 and 8, reference numeral 3 denotes an instrument panel cover (hereinafter referred to as an interior cover) that covers the surface of the instrument panel core 2, which is formed of a resin molded product integrally formed of a synthetic resin material such as polypropylene. It is configured. The interior cover 3 is fixed to the instrument panel core 2 fixed to a frame (not shown) of the vehicle by appropriate means such as tapping screws.

As shown in FIG. 7, a housing portion 20 for housing a metal airbag case 5 is provided on a left side portion of the interior cover 3 opposite to a passenger seat (for a Japanese car). Is formed. In addition, in the case of a foreign vehicle, it is provided at a position symmetrical to the above configuration. The partition member 21 is configured to be detachably fixed to a skeleton of a vehicle by a plurality of tapping screws in order to facilitate assembly to the interior cover 3 such as the case 5. Further, a break opening portion 30 which is opened when the airbag 4 is inflated and deployed is provided at a position of the interior cover 3 opposed to the housing portion 20.
Are formed. The break open portion 30 has a rectangular shape with substantially the same area as the opening 5aa of the case 5,
It is broken by a break groove 30a formed by laser processing, which will be described later, and is formed so as to be able to be divided into two from a center break groove 30b which is a fragile portion formed at the longitudinal center of the break open portion 30.

On the back surface of the interior cover 3, there is provided a reinforcing rib 12 having a rectangular cross section with a horizontal cross section projecting downward substantially along the outer periphery of the breaking open portion 30. A plurality of engaging holes 14 are respectively formed in the front and rear side walls 12a, 12a in the left-right elongate direction. The airbag 4 is accommodated in the airbag case 5 in a folded state.
It is connected to an inflator (gas generator) (not shown) provided outside the partition member 21 through a gas blowing pipe 22.

The break open portion 30 is provided with the interior cover 3.
And a central break groove 30 formed at a substantially central portion extending in the left-right direction of the break open portion 30 and opposed to the opening 5a of the case 5 disposed at a lower part of the case 5.
Before and after the splitting from the b, the left and right side walls 1 of the reinforcing rib 12 are constituted by the break open portions 31 and 32.
2b and 12b are separated from the left and right end surfaces 5c and 5c of the airbag case 5 by a predetermined distance, respectively, and a break groove 30a of a break open portion is formed between the separated portions.

The front and rear break opening portions 31, 32 before and after being divided into two by the center break groove 30b are formed by connecting the rear break opening portion 32 on the passenger seat side of the vehicle to the front break opening portion 31 on the windshield 40 side. The central break groove 30b may be formed so as to be offset so as to form a break open part having a slightly smaller area.

The break groove 30a and the center break groove 30b of the break opening portion 30 are provided with a pulse-like laser generated from a laser generating means (not shown) from the back side of the interior cover 3 in the right and left longitudinal direction of the break opening portion 30. Irradiation is performed while relatively moving the contour in the direction and the central portion to form a fragile portion in the interior cover 21. The front and rear breaking open portions 31 and 32 respectively have reinforcing plate members 33 and 3 on the back surfaces thereof.
3 is fixed to the horizontal main body portion by welding, and is bent downward from the hinge portion 34 connected to the main body portion, and is extended downward.
The mounting portion 35 includes the air bag case 5.
Slot 3 which is engaged with hook portion 36 which is projected and fixed to the side end surface of
7 are formed.

FIG. 10 shows the distance between the left and right side walls 12b, 12b of the reinforcing ribs and the inner surfaces of the left and right end faces 5c, 5c of the airbag case 5 in the front and rear short directions of the reinforcing ribs 12. 10 mm to 40 mm as indicated by the symbol L1.
mm, and the left and right ends 3 of the reinforcing plate members 33, 33
5 mm to 30 m indicated by the reference numeral L2 with an interval between the first and second portions 3a and 33a.
m and a break groove 3 formed in the break open portion.
0a, as indicated by reference symbol L3,
It is formed at a position separated from the right side walls 12b by 5 mm to 20 mm. The projecting length of the reinforcing rib 12 indicated by reference numeral L4 is 5 mm to 30 mm.

Next, a case in which a break opening portion 30 is formed in the interior cover 3 facing the housing portion 20 will be described. When forming the break groove 30a and the center break groove 30b of the break opening portion 30 that breaks when the airbag 4 is inflated and deployed in the interior cover 3, a pulse having a predetermined frequency, for example, 7 kHz, is supplied from a well-known laser generating means (not shown). (Output = 3 to 5 kW) is generated intermittently at a constant cycle, and this laser is applied from the back side of the interior cover 3 along the outer edge of the reinforcing plate 33 fixed to the back side in the left-right longitudinal direction. Irradiation while moving relatively at a predetermined speed.
It is formed at a position separated from the right side walls 12b by 5 mm to 20 mm.

Thus, a broken groove-shaped fragile portion is formed on the interior cover 3 according to the relative moving speed and the laser generation pattern from the laser generation means.

The split open portion 32 on the passenger seat side of the vehicle does not protrude from the horizontal surface 3b of the interior cover 3 to the continuous inclined front surface of the front passenger seat when the airbag 4 is inflated and deployed. The size is preferably set.

According to the airbag device for the passenger seat according to the embodiment of the present invention, when a vehicle such as an automobile collides, the impact force at the time of the collision is detected by the sensor. Then, a control device including a CPU determines whether or not the impact force detected by the sensor is equal to or greater than a predetermined value, and operates the inflator according to a signal output from the control device when it is determined to be equal to or greater than the set value. Then, a predetermined gas is generated, and the gas is supplied to the airbag 4, whereby the airbag 4 is rapidly inflated and deployed.

In the initial stage of inflation and deployment of the airbag 4, pressure is applied to the reinforcing plate 33, but the mounting portion 35 of the reinforcing plate 33 is engaged with the hook 36 of the airbag case 5 through the elongated hole 37. In this state, the pressure load on the upward movement of the reinforcing plate 33 is reduced, and the front and rear breaking open portions 3 before and after the deformation of the reinforcing plate 33 are deformed.
By reducing the load on the welded portions with the welded portions 1 and 32, the detachment of the welded portions is prevented, and the front and rear break open portions 31 and 32 are prevented from scattering. Immediately before the completion of the inflation and deployment of the airbag 4, the left and right short direction breaking grooves 30 a, 30 a are formed at positions apart from the left and right side walls 12 b, 12 b of the left and right short direction reinforcing ribs 12. As shown in the figure, the break open portion 30 of the interior cover 3 is deformed to absorb the shearing force, thereby preventing the break-up phenomenon occurring at the break portion of the break open portion 30 and providing a clean broken surface.

At the same time, the airbag 4 is inflated and deployed outside the interior cover 3 from the opened break opening portions 31 and 32, and the cushioning action of the inflated and deployed airbag 4 causes the chest of the occupant in the front passenger seat. By supporting the head and the head, the occupant can be protected from the impact force in the event of a vehicle collision, and its safety can be ensured.

Therefore, according to the airbag device for the passenger seat configured as described above, the break open portions 31 and 32 are provided.
Can be developed by a fracture groove 30a and a central fracture groove 30b, which are fragile parts formed on the back surface of the interior cover 3 by laser processing, and the fracture open parts 31, 32 and the reinforcing plate 33,
Since the configuration to reduce the burden on welding with 33,
Danger is prevented by reliably expanding the break open portions 31, 32 of the interior cover 3 together with the reinforcing plate members 33, 33 without deformation. Further, since the bending reaction force of the hinge portion is reduced, the mounting portions 35 of the reinforcing plate members 33 are not damaged.

Further, in the above-described embodiment, the air bag device is described for the passenger seat. However, it is needless to say that the present invention can be applied to an air bag device disposed at the center of the steering wheel, the side pillar portion, or the like.

In the above-described embodiment, the configuration in which the break open portion is opened in a double door is described. However, the present invention is not limited to this, and the configuration of the reinforcing plate material welded to the inner surface of the interior cover is slightly different. Needless to say, the present invention can also be applied to a structure in which the break open portion has a one-sided configuration.

[0032]

As described above, according to the airbag device for an automobile of the present invention, a rupture opening portion in which a fragile portion is formed by a rupture groove at a back surface position of the cover opposed to the opening portion of the airbag case; A reinforcing plate having a shape corresponding to the break opening portion, wherein a reinforcing rib having a rectangular horizontal section extending downward is protrudingly provided on the back surface side of the break opening portion of the interior cover, and the reinforcing member is provided. Engagement holes formed at predetermined intervals on the front and rear side walls (longitudinal direction) of the rib are provided, and the hook portions fixed to the front and rear end surfaces (longitudinal direction) of the airbag case are fitted to the engagement holes. The reinforcing plate is locked via a mounting portion extending downward from the hinge portion, and the left and right walls of the reinforcing rib are separated from the left and right end surfaces of the airbag case by a predetermined distance, respectively. Because the break groove of the break open part is formed between the separated parts, it is difficult to make a sharp edge on the break surface in the break part of the break open part, especially in the left and right front and rear short direction. In addition, an airbag device for a vehicle having a highly safe rupture opening can be provided.

[0033]

[Brief description of the drawings]

FIG. 1 is an explanatory view showing a case where an open portion for inflating and deploying an airbag is formed in a conventional instrument panel cover.

FIG. 2 is a longitudinal sectional view taken along line AA of FIG.

FIG. 3 is a partially enlarged explanatory view showing a state in which a break open portion for inflating and deploying an airbag is formed in a single-plate-shaped interior cover of a conventional passenger airbag device.

FIG. 4 is a schematic cross section taken along line BB in FIG. 3;

FIG. 5 is an explanatory view showing a state in which a break opening portion of the interior panel is removed.

FIG. 6 is an enlarged sectional view of a portion indicated by an arrow C in FIG. 5;

FIG. 7 is a perspective view of a main part of an airbag device applied to a passenger seat, showing an embodiment of an airbag device for an automobile according to the present invention.

FIG. 8 is a sectional view taken along line CC of FIG. 7;

FIG. 9 is a partial plan view of an interior cover in which a passenger airbag device of the automotive airbag device according to the present invention is disposed, and a schematic explanatory view in which a break open portion is removed.

FIG. 10 is a sectional view taken along line DD of FIG. 7;

FIG. 11 is an enlarged sectional view of a portion indicated by an arrow E in FIG. 9;

[Explanation of symbols]

 2 Instrument panel core 3 Interior cover (instrument panel) 3b Horizontal surface 4 Airbag 5 Airbag case 5a Opening 5b, 5b Front, rear side wall 5c, 5c Left, right side end surface 12 Reinforcement rib 12a, 12a Front, rear side wall 12b , 12b Left and right side walls 20 Housing 21 Partition wall member 30 Break open part 30a Break groove 30b Central break groove 31, 32 Front and rear break open parts 33, 33 Reinforcement plate 34 Hinge part 36 Connection hole

Claims (3)

[Claims] 1. An air bag, which is provided at at least one of a front portion, a handle center portion, and a side pillar portion covered by a vehicle interior cover and is inflated and deployed by gas from an inflator, is accommodated in a folded state. Also, an airbag case having an opening at a position facing the back surface of the interior cover is provided, and a fragile portion is formed by a breaking groove at a back surface position of the cover facing the opening of the airbag case. An automotive airbag device comprising an opening portion and a reinforcing plate member having a shape corresponding to the breaking opening portion, wherein a reinforcing rib having a horizontal rectangular cross section extending downward is provided on a rear surface side of the breaking opening portion of the interior cover. In addition, engaging holes formed at predetermined intervals are provided in front and rear side walls (longitudinal direction) of the reinforcing rib, respectively, and the engaging holes are provided in front of the airbag case and in the engaging holes. A hook portion fixed to a side end surface (longitudinal direction) is locked via a mounting portion extending downward from a hinge portion of the reinforcing plate, and left and right walls of the reinforcing rib are connected to a left side of the airbag case. An airbag device for an automobile, wherein the airbag device is separated from the right end face by a predetermined distance, and a break groove of a break open portion is formed between the separated portions. 2. The distance between the left and right side walls of the reinforcing rib and the left and right end surfaces of the airbag case is set to 10 mm to 4 mm.
0 mm, the distance between the left and right ends of the reinforcing plate is 5 mm to 30 mm, and the breaking groove formed in the breaking open portion is 5 m from the left and right walls of the reinforcing rib.
An airbag device for an automobile, wherein the airbag device is formed at a position separated by m to 20 mm. 3. The breaking groove is configured to transmit a pulsed laser generated from a laser generating means from the back side of the interior cover along a left-right longitudinal contour of the breaking opening and at a predetermined interval in front and rear short directions. The automobile according to claim 1 or 2, wherein a thick portion and a thin portion are formed at a predetermined interval on the back surface of the interior cover by irradiating while irradiating the interior cover relatively to a distant position. Air bag device.