JP2002370599A - Air bag device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an air bag device capable of rapidly opening a door part of an air bag cover made of synthetic resin and rapidly unfolding and expanding an air bag even at a low temperature while inhibiting a reduction of feeling. SOLUTION: The air bag device M1 is provided with the folded air bag 1 and the air bag cover 13, made of synthetic resin, disposed so as to cover the air bag. In the air bag device M1, the door part 15 is formed on a part covering the air bag 1 of the air bag cover 13 and a breaking intended part 22 made thinner by providing a recessed groove is arranged on a part near the door part 15. A deformation auxiliary part 27 made thicker than a thickness of the breaking intended part 22 by providing a deformable recessed groove spaced from the breaking intended part 22 so as to expand a part near a breaking starting point intended part 23 at the time of starting of expansion of the air bag 1 is arranged at a part near a part made to the breaking starting point intended part 23 in the breaking intended part 22.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an airbag apparatus including a folded airbag and an airbag cover arranged to cover the airbag. And, in the present invention, particularly, at a portion of the airbag cover that covers the airbag, a door portion is provided around which a rupture scheduled portion made thin by providing a concave groove is formed, and when the airbag is inflated and inflated, The present invention relates to an airbag device configured to break a portion to be broken and open a door.

[0002]

2. Description of the Related Art In an airbag apparatus having the above structure, it is desirable to quickly open the door of an airbag cover from the viewpoint of quickly deploying and inflating the airbag.
However, in winter or the like, the temperature of the airbag cover becomes low, so that when the airbag is inflated, the portion to be broken may not be broken smoothly. In particular, this phenomenon was remarkable when a single-layer airbag cover having no skin layer was used. Therefore, as an airbag cover configured to open the door smoothly, Japanese Patent Laid-Open No.
There is an instrument panel (hereinafter abbreviated as "instrument panel") having a configuration shown in Japanese Patent No. 119678.

[0003] This instrument panel has a structure in which two door portions are respectively opened in the front-rear direction of the vehicle. Around each of the door portions, a concave groove shape that can be broken by being pressed by an inflating airbag is provided. The part to be broken was arranged. And
The rupture scheduled portions are arranged between the door portions so as to divide the door portions from each other, and are arranged so as to intersect with the planned transverse rupture portions near substantially the center of the planned transverse rupture portions. And a longitudinally broken portion to be broken.
In this instrument panel, when the portion to be broken is broken by being pressed by the inflating airbag, the portion to be broken starts to break near the intersection of the portion to be broken longitudinally and the portion to be broken transversely. Was.

However, in the instrument panel having the above structure, both the portion to be broken in the horizontal direction and the portion to be broken in the vertical direction are broken, and each door portion is broken along the portion to be broken in the vertical direction. And four doors were opened at the beginning of the break. For this reason, the pressure for pushing the door portion of the airbag open is dispersed at the beginning of the rupture, and it takes time until the door portion is fully opened. In addition, the front end side of each opened door is divided into two pieces, and if the corner of the divided part interferes with the occupant, the touch is deteriorated.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and it is possible to quickly open a door portion of a synthetic resin airbag cover even at a low temperature while suppressing a decrease in feel.
An object of the present invention is to provide an airbag device capable of quickly deploying and inflating an airbag.

[0006]

An airbag device according to the present invention includes a folded airbag and an airbag cover made of a synthetic resin disposed so as to cover the airbag. A door portion is formed in a portion covering the airbag, and a rupture scheduled portion made thin by providing a concave groove is provided around the door portion, and when the airbag is inflated and inflated, the rupture scheduled portion is formed. An airbag device configured to break and open a door portion, which is deformed so as to protrude near a break starting point expected portion when an airbag starts inflating near a portion to be a break starting point portion in a planned breaking portion. Preferably, a groove is provided at a distance from the portion to be broken, and a deformation assisting portion that is thicker than the portion to be broken is provided.

Further, it is preferable that the groove forming the breakable portion and the deformation assisting portion is arranged so as to open toward the folded airbag.

Further, it is preferable that the portion to be broken is formed so as to be thin toward the portion to be broken.

Further, it is preferable that the deformation assisting portion is formed in a straight line in a direction intersecting with the planned breaking portion near the planned breaking start point.

[0010]

According to the airbag apparatus of the present invention, since the deformation assisting portion is deformed so as to be pressed by the inflating airbag and to protrude near the break start point, the tensile force is applied near the break start point. Will work easily. Then, if a tensile force acts on the vicinity of the projected fracture starting point scheduled portion, the fracture scheduled portion formed thinner than the deformation assisting portion is started to be fractured from the fracture starting point scheduled portion, the fracture propagates, and the door portion is moved. Will open. At this time, since the deformation assisting portion is formed apart from the planned breaking portion, at the start of the breaking of the planned breaking portion, the fracture does not propagate from the planned breaking start point to the deformation assisting portion, and the planned breaking start portion does not. Therefore, it propagates smoothly along the portion to be broken.

That is, in the airbag device of the present invention,
When the airbag is inflated, the deformation assisting part is deformed so as to raise the vicinity of the expected fracture start point, so that even at low temperatures, a large tensile force is applied to the vicinity of the expected fracture start point to quickly raise the expected fracture start point. Simultaneously, the rupture generated at the rupture start point scheduled portion can be quickly propagated to the rupture scheduled portion, so that the door portion can be opened smoothly and the airbag is quickly deployed. be able to.

Further, since the deformation assisting portion is not connected to the portion to be broken and is thicker than the portion to be broken, it does not break when the door is opened. Even if the front end of the open door interferes with the occupant, the feeling is not reduced.

Therefore, in the airbag device of the present invention, it is possible to quickly open the door portion of the synthetic resin airbag cover even at a low temperature while suppressing a decrease in feel, and to quickly deploy the airbag. It is possible to inflate.

According to a second aspect of the present invention, when the groove forming the scheduled break portion and the deformation assisting portion is configured to open toward the folded airbag, the scheduled break portion and the deformation assisting portion are positioned from the occupant side. Invisible, does not degrade the appearance of the airbag cover.

Further, if the portion to be broken is formed so as to be thin over the portion to start breaking, the vicinity of the portion to start breaking is raised, and a tensile force acts near the portion to start breaking. In this case, it is possible to more easily break the scheduled break start point.

Furthermore, if the deformation assisting portion is formed in a straight line in a direction intersecting with the portion to be fractured near the break starting point portion, one or more deformation assisting portions may be provided. In addition, it is possible to raise the vicinity of the fracture starting point expected portion with the influence on the design surface side of the airbag cover being minimized. In addition, it is possible to reduce non-uniformity in feeling when pressing the door.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings.

The airbag device M1 of the embodiment is an airbag device for a passenger seat, as shown in FIGS. 1 to 3, is disposed below the instrument panel 11 in front of the passenger seat, and is folded and stored. -Shaped airbag 1 and cylinder-type inflator 2 for supplying inflation gas to airbag 1
And a case 7 that has a box shape with an open top, and stores and holds the airbag 1 and the inflator 2, and an annular bag retainer 3 for attaching the airbag 1 and the inflator 2 to the case 7. is there. In addition, above the case 7, so as to cover the airbag 1,
In this configuration, a lid 13 as an airbag cover is formed integrally with the instrument panel 11 and disposed.

In the airbag 1, a plurality of bolts 4 arranged in the bag retainer 3 are inserted through insertion holes formed at predetermined positions of the case 7, and each of the bolts 4 is arranged on the back side of the case 7. By screwing the nut 5, the nut 5 is pressed by the bag retainer 3 and attached to the case 7.

The case 7 is connected to the lid 13 using a holding member 10 arranged on the front side of the vehicle. A locking projection 8 is provided on a side wall portion of the case 7 on the vehicle front side.
A plurality are formed. Each locking projection 8 is provided with a locking hole 17a formed in a front side wall 17 of the lid 13 which will be described later.
And is formed to protrude forward.
When these locking projections 8 are locked to the locking holes 17a,
A protrusion 8a is provided to protrude forward from the front side wall portion 17, and the protrusion 8a penetrates in the up-down direction to
An insertion hole 8b for inserting the zero insertion portion 10a is formed. A plurality of locking claws 9 are fixed to the case 7 via a mounting seat 9a at a side wall portion of the case 7 on the vehicle rear side. Each locking claw 9 is attached to the lid
3, and is locked to the rear side peripheral edge of a locking hole 18a formed in a rear side wall portion 18 described later, and is formed to project rearward in a substantially inverted L-shaped cross section.

The instrument panel 11 is made of synthetic resin and has a general portion 12 and a lid 13 as an airbag cover for covering the folded airbag 1. Then, the general portion 12 and the lid 13 are integrally formed by two-color molding using a compatible material. In the embodiment, the general portion 12 is formed from fiber-reinforced polypropylene, and the lid 13 is formed from a polyolefin-based thermoplastic elastomer.

The cover 13 has two doors 15 and 15 which are pushed by the airbag 1 when inflated and open in the front-rear direction of the vehicle. A cylindrical side wall portion 16. Door 15.1
5, a first rupture scheduled portion 22 having a thin wall provided with a concave groove having a substantially wedge-shaped cross section is arranged so that the back surface side (the folded airbag 1 side) becomes an opening. Further, between the door portions 15 and left and right side wall portions 19 and 20 to be described later, a second breakable portion 24 is formed continuously with the first breakable portion 22. Similarly to the first breakable portion 22, the second breakable portion 24 is also formed to be thin by providing a concave groove having a substantially wedge-shaped cross section so that the back surface side is opened. The front and rear side walls 17 and 18 to be described later and each door 15.1.
The vicinity of a portion connected to the door 5 is a hinge 26 serving as a center of rotation of each door 15.

In the vicinity of the center in the left-right direction of each door part 15, as shown in FIGS. 2 and 4, a concave groove having a substantially wedge-shaped cross section is provided so that the back side is opened. The deformation assisting portions 27 are respectively disposed so as to be substantially orthogonal to the first breakable portions 22. This deformation assisting part 27
Is thicker than the first breakable portion 22 so that the end portion 27a
Is formed so as to be separated from the first scheduled rupture portion 22, and can be deformed so as to protrude near the rupture start point scheduled portion 23 located substantially at the center of the first rupture scheduled portion 22 when the inflation of the airbag starts. Is what you do. In addition, each deformation assisting portion 27 is disposed so that the end portion 27a side faces the break start point scheduled portion 23.

The side wall 16 includes front and rear side walls 17 and 18 arranged in the front-rear direction of the vehicle, and left and right side walls 19 and 20 arranged in the left and right direction of the vehicle. A locking hole 17 a for inserting the locking projection 8 formed in the case 7 is formed in the front wall 17, and a rear wall 18 is formed in the rear wall 18.
Locking hole 1 for locking locking claw 9 formed in case 7
8a are formed.

The holding member 10 has a plurality of comb-shaped insertion portions 10a, and the left and right side wall portions 19 of the lid 13 are provided.
A flange portion 7 extending from the case 7 outside of 20
a. Bolt 30 is fixed to 7a, and lid 13 is attached to case 7.
Is fixed.

As shown in FIG. 3, the first breakable portion 22 is formed so that the intermediate portion 22a is thinner than the end portion 22b so as to be thinner toward the breakage starting point portion 23. Specifically, in the embodiment, when the thickness dimension t1 of the door portion 15 is set to 3.0 to 3.5 mm, the first
The thickness t2 of the intermediate portion in the rupture scheduled portion 22 is set to 0.
8 mm, the thickness t3 of the end portion 22b is 1.1 mm
Is set to In addition, the second scheduled fracture portion 24 has a thickness of 1.1 mm at a connection portion with the first scheduled fracture portion 22,
In order to provide a thickness of about 2.5 mm near the front / rear side walls 17 and 18, respectively, from the vicinity of the connection portion with the first rupture scheduled portion 22 to the vicinity of the front / rear side walls 17 and 18.
It is set to increase the thickness dimension. Further, the thickness t4 of the deformation assisting portion 27 is set to 2.0 to 2.5 mm, and the opening width dimension h1 of the deformation assisting portion 27 is 1.5 mm.
mm.

Next, the assembly of the airbag device M1 of the embodiment will be described.

First, a bag retainer 3 is attached to the airbag 1.
The airbag 1 is folded by inserting a plurality of bolts 4 arranged in the airbag 1. Then, the folded airbag 1 is placed in the case 7 together with the bag retainer 3, and a nut 5 is screwed into each of the bolts 4 protruding on the back side of the case 7,
The airbag 1 and the bag retainer 3 are attached to the case 7 in advance. Next, the locking claw 9 formed on the case 7 is locked on the rear side peripheral edge of the locking hole 18 a formed on the rear side wall 18 of the lid 13. Then, the case 7 is inserted between the front and rear side walls 17 and 18 so as to widen the gap between the front side wall 17 and the rear side wall 18 in the cover 13, and is inserted into the front side wall 17 of the cover 13. Formed locking hole 17
Insert each locking projection 8 of the case 7 into a. Then, the insertion portion 10a of the holding member 10 is inserted into the insertion hole 8b of the projection 8a of the locking projection 8, and the holding member 10 is fixed to the flange portion 7a of the case 7 with the bolt 30. 13 can be assembled.

The airbag apparatus M1 assembled in this manner is screwed to a vehicle body sheet metal or the like via a bracket or the like projecting from the case 7 (not shown). Once installed,
It can be mounted on vehicles.

When the instrument panel 11 is mounted on a vehicle, predetermined instruments and the like are provided.

When the inflator 2 discharges the inflation gas after mounting the airbag device M1 on the vehicle, the airbag 1 is inflated, and the first rupture portion 22 and the second rupture schedule of the lid 13 are formed. The part 24 is broken, and the door parts 15
As shown by a two-dot chain line in FIG. 2, the vehicle is opened in the front-rear direction of the vehicle, and greatly protrudes from the case 7.

At this time, the airbag device M1 of the embodiment
Then, as shown by the two-dot chain line in FIG. Since the deformation assisting portion 27 is deformed, a tensile force is likely to act on the vicinity of the fracture starting point scheduled portion 23. And
When a tensile force acts on the vicinity of the raised scheduled fracture start point 23, the first fracture scheduled part 22 formed thinner than the deformation assisting part 27 starts to be fractured from the fracture start scheduled part 23, and the first fracture scheduled. The rupture propagates from the portion 22 to the second scheduled rupture portion 24, and the doors 15 and 15 are opened. At this time, since the deformation assisting portion 27 is disposed with the end portion 27a separated from the first breakable portion 22,
At the start of the rupture of the rupture scheduled part 22, the rupture does not propagate from the rupture start scheduled part 23 to the deformation assisting part 27, but from the rupture scheduled start part 23 along the first and second scheduled rupture parts 22 and 24,
It will propagate smoothly.

That is, the airbag device M1 of the embodiment
Then, at the time of inflation of the airbag 1, the deformation assisting portion 27 is deformed so as to raise the vicinity of the rupture starting point expected portion 23, thereby applying a large tensile force to the rupture starting point expected portion 23 even at a low temperature. At the same time as the break start point portion 23 is quickly broken, the break generated at the break start point portion 23 can be quickly propagated to the first break scheduled portion 22, so that the door portions 15 can be opened smoothly. This allows the airbag 1 to be quickly deployed.

Further, since the deformation assisting portion 27 is not connected to the first breakable portion 22 and is thicker than the first breakable portion 22, it should not break when the doors 15 are opened. Therefore, unnecessary corners are not generated in the doors 15, and even if the front ends of the open doors 15 interfere with the occupant, the feeling is not reduced.

Therefore, in the airbag device M1 of the embodiment, it is possible to quickly open the doors 15 of the synthetic resin lid 13 (airbag cover) even at a low temperature, while suppressing a decrease in feel. As a result, the airbag 1 can be quickly deployed and inflated.

As an airbag device M2, FIG.
As shown in FIG. 7, the lid 3 having a configuration including one door portion 34
An instrument panel having 3 may be used. This airbag device M2 is the same as the airbag device M1 of the above-described embodiment except that the lid 33 of the instrument panel 31 includes one door.
The configuration is the same as that described above, and the same reference numerals are assigned and the description is omitted.

The lid 33 of the instrument panel 31 in this embodiment is pressed by the airbag 1 at the time of inflation and is opened by a single door portion 34 toward the front of the vehicle. 7, a substantially rectangular cylindrical side wall portion 16 for attaching 7,
It has. Between the door part 34 and the rear side wall part 18, the first to-be-ruptured part 22 which is provided with a concave groove having a substantially wedge-shaped cross section and is made thin so as to open on the back surface side is arranged. Further, between the door portion 34 and the left and right side wall portions 19 and 20, a second breakable portion 36 is formed continuously with the first breakable portion 35. Similarly to the first breakable portion 35, the second breakable portion 36 is also formed to be thin by providing a groove having a substantially wedge-shaped cross section so that the back surface side is opened. The vicinity of the portion where the front side wall portion 17 and the door portion 34 are connected is the door portion 34.
The hinge portion 26 is a rotation center portion of the hinge. First
Like the first scheduled break portion 22 in the above-described airbag device M1, the scheduled break portion 35 connects the intermediate portion 35a to the end portion 3 so as to be thin toward the planned break start point portion 36.
5b. Further, the second breakable portion 36 is also the second breakable portion in the above-described airbag device M1.
Similarly to the scheduled break portion 24, the thickness is set to increase from the connection portion with the first scheduled break portion 35 toward the front wall portion 17.

The door portion 34 is provided with a plurality of thin, straight deformation assisting portions 39 having a concave groove having a substantially wedge-shaped cross section so that the back surface side is open. Similar to the deformation assisting portion 27 in the above-described airbag device M1, the deformation assisting portion 39 is formed to be thicker than the first breakable portion 35 so as to separate the end portions 39a from the first breakable portion 35, respectively. When the inflation of the airbag is started, the airbag can be deformed so as to protrude in the vicinity of the planned break start point portion 36 located substantially at the center of the first planned break portion 35. In the embodiment, the deformation assisting unit 39 is configured as shown in FIG.
As shown in the figure, the portion is formed in a straight line in the direction intersecting with the first fracture scheduled portion 35 in the vicinity of the planned fracture start portion 36, and the fracture planned start portion 36
A plurality (five in the example in the figure) is provided so as to spread radially from the front.

The instrument panel 3 having the lid 33 constructed as described above
Also in the airbag device M2 using the airbag device 1, the airbag 1 is pressed by the inflating airbag 1 as shown by a two-dot chain line in FIG. Since the deformation assisting portion 39 is deformed, a tensile force is applied to the vicinity of the predetermined fracture starting point portion 36 to quickly break the predetermined fracture starting point portion 36, and simultaneously, Since it can be quickly propagated to the breakable portion 35, the door portion 34 can be opened smoothly, and the airbag 1 can be quickly deployed.

In the airbag devices M1 and M2, the grooves forming the first and second breakable portions 22, 24, 35 and 37 and the deformation assisting portions 27 and 39 are formed on the back side (the folded airbag). 1), the first and second
Expected break portions 22, 24, 35, 37 and deformation assisting portions 27
The 39 is not visible from the occupant side, and does not degrade the external design of the lids 13 and 33 as airbag covers. If this point is not taken into consideration, the first and second scheduled fracture portions 22 and 24
A configuration may be adopted in which the grooves forming the 35 and 37 and the deformation assisting portions 27 and 39 are opened on the front side (occupant side).

Further, in the airbag devices M1 and M2,
The intermediate portions 22 are formed such that the first breakable portions 22 and 35 are thinner toward the break start point portions 23 and 36, respectively.
a and 35a are formed to be thinner than the end side portions 22b and 35b. Therefore, the fracture starting point scheduled portion 23
When the vicinity of the protrusion 36 rises and a tensile force acts on the vicinity of the expected fracture start points 23 and 36, the expected fracture start points 23 and 36 can be more easily broken. Of course, if this point is not taken into consideration, the first breakable portions 22 and 35 may be configured to have substantially the same thickness over the entire length.

Further, in the airbag devices M1 and M2, each of the deformation assisting portions 27 and 39 is connected to the break starting point scheduled portion 23.
Since it is formed in a straight line in a direction intersecting the first breakable portions 22 and 35 near 36, even if one or a plurality of deformation assisting portions 27 and 39 are provided, the lid 13 and the airbag cover 13 In the state where the influence on the design surface side of 33 is minimized, it is possible to protrude the vicinity of the fracture starting point scheduled portions 23 and 36. In addition, it is possible to reduce unevenness in touch when the doors 15 and 34 are pressed. Of course, if this point is not considered, the deformation assisting portions 27 and 39 may be arranged in a curved shape.
To have a concave surface that allows 3.39 to be raised,
It may be formed.

When the deformation assisting portions 27 and 39 are arranged in a straight line, the thickness of the deformation assisting portion is 1.5 times larger than the thickness of the intermediate portion in the first breakable portion.
It is preferable that the thickness is set to be about 4 to 4 times (preferably 2 to 3.5 times). If the thickness of the deformation assisting portion has a thickness less than 1.5 times the thickness of the intermediate portion, the deformation assisting portion is too thin and the deformation assisting portion is supposed to be broken when the predetermined fracture starting point breaks. This is because there is a possibility that the portion may be broken. Further, when the deformation assisting portion has a thickness of four times or more the thickness of the intermediate portion, the deformation assisting portion is too thick, and when the deformation assisting portion is deformed, the vicinity of the fracture starting point expected portion is sufficient. This is because there is a possibility that the projection does not rise. Further, the opening width dimension of the deformation assisting portion is preferably set to 0.5 to 2.5 mm (preferably 1 to 2 mm). If it is less than 0.5 mm, there is a possibility that the vicinity of the expected fracture starting point may not be sufficiently raised when the deformation assisting portion is deformed, and if it is more than 2.5 mm, the feeling when pressed is not good. When the breakage at low temperature is not performed smoothly, if the number of the deformation assisting portions is increased within the above range, the vicinity of the planned fracture start point can be greatly raised, and the smooth fracture start point can be planned. Breakage from the part can be secured. Also,
When arranging a plurality of scheduled fracture start portions, the plurality of deformation assisting portions may be arranged so that the first scheduled fracture portions are substantially orthogonal to each other. In order to achieve this, it is preferable that a plurality of deformation assisting portions are radially arranged with the break start point scheduled portion as a center.

In the airbag device M1 (M2), the general section 12 and the lid 1 are used as the instrument panel 11 (31).
3 (33) is integrally formed by two-color molding. Of course, an instrument panel in which a general portion and a lid are formed separately may be used. As shown in FIG. 7, a three-layered instrument panel 41 may be used.

The instrument panel 41 includes a base 42, a foam layer 45 disposed on the upper surface of the base 42, and a skin layer 46 disposed on the upper surface of the foam layer 45. The base portion 42 includes a general portion 43 having a substantially square opening 43a.
And a lid 4 serving as an airbag cover that is disposed in the opening 43a of the general portion 43 and covers the folded airbag 1.
4. The lid 44 is, similarly to the lid 14 in the above-described airbag device M1, a door 15.1.
5, a first breakable portion 22, a second breakable portion (not shown), and a deformation assisting portion 27. Then, the first and second layers in the foam layer 45 and the skin layer 46 are formed.
A slit 47 is formed at the portion of the portion to be broken.

In the airbag device M3 using the instrument panel 41 having such a configuration, when the airbag 1 is inflated, as shown by a two-dot chain line in FIG. Since the deformation assisting portion 27 is deformed so that the vicinity of the portion 23 is raised, the fracture starting point scheduled portion 23
Since a tensile force is applied to the vicinity to quickly break the scheduled fracture start point portion 23, and at the same time, the fracture generated in the scheduled fracture start point portion 23 can be quickly propagated to the first fracture scheduled portion 22, the door The portions 15 can be opened smoothly, and the airbag 1 can be quickly deployed.

Although the embodiment has been described by taking the passenger seat airbag device as an example, the airbag device to which the present invention can be applied is not limited to the passenger seat airbag device. The present invention is also applicable to an airbag device for a steering wheel.

[Brief description of the drawings]

FIG. 1 is an overall perspective view showing an instrument panel of a passenger airbag device according to an embodiment of the present invention.

FIG. 2 is a longitudinal sectional view in the vehicle front-rear direction showing a use mode of the airbag device of the embodiment, and corresponds to a II-II portion in FIG.

FIG. 3 is a vertical cross-sectional view in a vehicle left-right direction showing a use mode of the airbag device of the embodiment, and corresponds to a III-III part in FIG. 2;

FIG. 4 is a bottom view of a lid used in the airbag device of the embodiment.

FIG. 5 is a sectional view showing a VV portion in FIG. 4;

FIG. 6 is a longitudinal sectional view in a vehicle front-rear direction showing a use mode of an airbag device according to another embodiment of the present invention.

FIG. 7 is a bottom view of a lid used in the airbag device of the embodiment.

FIG. 8 is a longitudinal sectional view in a vehicle front-rear direction showing a use mode of an airbag device according to still another embodiment of the present invention.

[Explanation of symbols]

 11.31.41 ... instrument panel, 13.33 ... lid (airbag cover), 15.34 ... door part, 22.35 ... first break scheduled part, 23.36 ... break start point planned part, 24.37 ... Second breakable portion, 27/39: deformation assisting portion, M1, M2, M3: airbag device.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Kazumichi Shigeno 1 Ochiai Ogata, Kasuga-cho, Nishi-Kasugai-gun, Aichi Prefecture Inside Toyoda Gosei Co., Ltd. Address Toyoda Gosei Co., Ltd. F-term (reference) 3D054 AA03 AA14 BB09 BB16 BB23

Claims (4)

[Claims] 1. An airbag comprising: a folded airbag; and an airbag cover made of a synthetic resin disposed so as to cover the airbag. A door portion of the airbag cover covers the airbag. Is formed around the door portion, and a breakable portion provided with a concave groove and thinned is provided, and when the airbag is deployed and inflated, the breakable portion is broken to break the door portion. An airbag device configured to be opened, in the vicinity of a portion to be a rupture starting point scheduled portion in the rupture scheduled portion, at the start of inflation of the airbag, so as to be deformable to protrude near the rupture starting point scheduled portion, An airbag device, wherein a deformation assisting portion provided with a concave groove separated from the scheduled break portion and having a greater thickness than the scheduled break portion is provided. 2. The airbag device according to claim 1, wherein the groove forming the breakable portion and the deformation assisting portion is opened on the side of the folded airbag. 3. The airbag device according to claim 1, wherein the rupture scheduled portion is formed so as to be thin toward the rupture start point scheduled portion. 4. The method according to claim 1, wherein the deformation assisting portion is formed in a straight line in a direction near the planned fracture start point and in a direction intersecting with the planned fracture portion. Airbag device.