JP2000095057A - Air bag device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent bolt holes provided in the tip part of a protector sheet, from being elongated or deformed by tension generated at the time of winding the protector sheet around an air bag in an air bag device. SOLUTION: A protector sheet 40 sewn on foundation cloth 42 along a sewing line S7 is provided with bolt holes 50, 52 respectively at the base end part 401 and the tip part 402, and provided with fragile rupture part 54, 55 between the base end part 401 and the tip part 402. The bolt holes 52 provided in the tip part 402 and locked to unillustrated bolts when the protector sheet 40 is wound around the outer periphery of the folded air bag are offset from the rupture parts 54, 55 by distance α or β in the longitudinal right-angled direction of the protector sheet 40. The tension of the base end part 401 of the protector sheet 40 does not, therefor, act directly on the inner peripheral surfaces of the bolt holes 52.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an airbag device for restraining an occupant by deploying an airbag in a vehicle cabin with high-pressure gas generated by an inflator at the time of a vehicle collision.

[0002]

2. Description of the Related Art Japanese Patent Application No. 9-226787 proposes an airbag apparatus in which a substantially band-shaped protector sheet is wound around an outer periphery of a folded airbag to hold the airbag in a folded state. Have been. The protector sheet is provided with a fragile break portion, and when tension is applied to the protector sheet when the airbag is inflated, the break portion breaks and the airbag can be inflated.

[0003]

In the above-mentioned prior art, a bolt hole is formed at each of a base end and a front end of a protector sheet, and the bolt hole is fixed to a bolt for fixing an inflator and an airbag to a frame. The engagement protects the protector sheet so as to enclose the airbag. However, since the break portion is formed near the front end portion of the protector sheet so that the folded airbag can be quickly opened, the bolt hole at the front end portion of the protector sheet and the break portion are arranged at positions close to each other. Will be. As a result, when the protector sheet is wrapped around the outer periphery of the folded airbag and the bolt holes at the distal end are locked to the bolts, the tension at the base end of the protector sheet is directly applied to the bolt holes at the distal end via the break portion. And the load acting on the bolts may cause the bolt holes in the protector sheet to expand or deform, making it impossible to reliably hold the airbag.

The present invention has been made in view of the above circumstances, and prevents a bolt hole provided at a front end portion of a protector sheet from being stretched or deformed by tension when the protector sheet is wound around an airbag. The purpose is to:

[0005]

In order to achieve the above object, the invention according to the first aspect is directed to an airbag, an inflator housed inside the airbag, and wrapping around an outer periphery of the folded airbag. A substantially belt-shaped protector sheet that is held to hold the airbag in a folded state;
In order to fix the inflator to the frame together with the airbag, a bolt extending from the inflator to the outside through the airbag is provided.
A bolt hole is formed at the distal end portion in the longitudinal direction, the bolt hole being locked by the bolt, and a fracture portion that is fractured by a tension acting upon inflation of the airbag at a position closer to the proximal end portion in the longitudinal direction than the bolt hole. Wherein the bolt hole and the break portion are arranged so as to be deviated in a direction perpendicular to the longitudinal direction of the protector sheet.

When a substantially band-shaped protector sheet is wound around the outer periphery of the folded airbag to hold the airbag in a folded state, a bolt hole formed in a longitudinal end portion of the protector sheet is engaged with a bolt. At this time, if the bolt hole is located near the break portion of the protector sheet, the tension at the base end of the protector sheet is directly applied to the inner peripheral surface of the bolt hole via the break portion. Acting, the bolt holes may be elongated or deformed, and the protector sheet may be loosened. However, according to the configuration of claim 1, since the bolt holes and the break portions of the protector sheet are arranged so as to be deviated in the direction perpendicular to the longitudinal direction of the protector sheet, the protector sheet is wound around the outer periphery of the airbag and the bolt holes are formed on the bolts. When locking, the tension at the base end of the protector sheet does not directly act on the inner peripheral surface of the bolt hole. as a result,
The bolt holes of the protector sheet do not expand or deform, and the protector sheet is prevented from loosening and the folded state of the airbag is prevented from being collapsed.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described based on embodiments of the present invention shown in the accompanying drawings.

FIGS. 1 to 16 show an embodiment of the present invention. FIG. 1 is a perspective view of a seat provided with an airbag device.
2 is an enlarged sectional view taken along line 2-2 of FIG. 1, FIG. 3 is a view taken in the direction of arrow 3 in FIG. 2, FIG. 4 is a sectional view taken along line 4-4 in FIG. 3, and FIG.
6 is a sectional view taken along line 6-6 in FIG. 3, FIG. 7 is an enlarged view of a part 7 in FIG. 3, FIG. 8 is an exploded perspective view of the airbag module, and FIG. FIG. 10 is a perspective view of FIG.
FIG. 11 is a sectional view taken along line 11-11 of FIG. 9, FIG.
2 is a sectional view taken along line 12-12 of FIG. 9, FIG. 13 is an enlarged view of 13 part of FIG. 9, FIG. 14 is an enlarged view of 14 part of FIG. 9, FIG. 15 is an enlarged view of 15 part of FIG. It is an operation explanatory view at the time of assembly of a module.

As shown in FIG. 1, a front seat S on the right side of an automobile has a seat cushion 1 arranged substantially horizontally.
And a seat back 2 extending rearward and upward from a rear end of the seat cushion 1, and a headrest 3 provided at an upper end of the seat back 2. An airbag module M is housed inside the right side of the seat back 2 of the front seat S. When the airbag module M is activated, the airbag 4 breaks the sewing portion 25 of the seat back 2 and pushes open to open the front seat S. Is deployed obliquely forward so as to block the space between the right side surface of the occupant sitting at the center pillar and the front door (not shown).

As is clear from FIG. 2, the seat back 2
Pipe frame 11 extending vertically along the right edge of
Then, a metal module mounting frame 12 extending to the front of the vehicle body and a metal retainer 13 extending to the inside of the vehicle body are fixed by welding. On the right side of the module mounting frame 12, the airbag module M is provided with two bolts 14,
It is fixed by 14 and two nuts 15, 15.
The shape retaining material 16 made of a coarse blanket is used for the airbag module M.
Extends from the front surface of the seat back 2 to the left side of the vehicle body in the thickness direction of the seat back 2 and is connected to a pipe frame (not shown) on the left side of the vehicle body. A mesh-shaped spring 17 is stretched on the inner periphery of the pipe frame 11, and a pad 19 made of sponge is mounted on the front surface of the shape-retaining material 16.

A central portion of the front surface of the seat back 2 is covered with a first covering material 20, and both left and right sides and an upper portion of the first covering material 20 are covered with a second covering material 21. The left and right side surfaces and the upper surface of the continuous seatback 2 are covered with a third covering material 22, and the rear surface of the seatback 2 is covered with a fourth covering material 23. First
The covering material 20 and the second covering material 21 are sewn at a sewing portion 24, and the second covering material 21 and the third covering material 22 are sewn at a sewing portion 25. The sewing part 25 has a bead 2
6 are sewn together. Tongue piece 27 extending from sewing portion 24
A clip 28 is provided at the end of the first cover member 20, and the first cover member 20 and the second cover member 21 are held in a predetermined shape by locking the clip 28 to the spring 17.
Further, a clip 30 is provided at the tip of a tongue piece 29 connected to the rear part of the third coating material 22, and the third coating material 22 is fixed by locking the clip 30 to the retainer 13.

Next, the structure of the airbag module M will be described with reference to FIGS.

The metal retainer 31 has a J-shaped cross section.
Body 31₁And the main body 31 ₁Extending from one side edge of
Pair of clamps 31_Two, 31_TwoWith
These body parts 31₁And clamp part 31_Two, 31_TwoBy
The round cross section formed is filled with propellant inside.
A cylindrical inflator 32 is supported. Retainer 31
And the inflator 32 is provided with the folded airbag 4.
It is stored so as to be wrapped around the base end. The bolt 1
Reference numerals 4 and 14 denote clamp portions 31 of retainers 31._Two, 31_Two,
Main unit 31₁And through the side plate 33
And the module is mounted.
Fastened by nuts 15 through the frame 12
It is.

The retainer 31, the side plate 33, the inflator 32, and the folded airbag 4 are housed in a module case 35 integrally formed of synthetic resin. The module case 35 includes a tray-shaped case body 36 opening toward the right side of the vehicle body, and the case body 3.
A lid 37 connected to the trailing edge of the sixth through a hinge portion 38;
Are provided on the upper edge, the front edge and the lower edge of the case body 36, and the five hooks 36 ₁ .
The lid 37 is fixed so as to cover the opening of the case body 36 by engaging with the five hook engagement holes 37 ₁ provided on the front edge and the lower edge.

As is apparent from FIG.
The outer surface of the case body 36 along the opening edge 39 on the outer periphery of
Step 36 retreated more than_TwoIs formed and the lid 3
7 formed on the outer periphery of 7_TwoIs the step 36_Two
To the outer circumference of On the inner surface of the front edge of the lid 37
Flange 37_TwoA number of protrusions 37 along the_Three… Formed
These projections 37_Three… And flange 37_TwoWith
The opening edge 39 of the case main body 36 is fitted therebetween. The result
As a result, as shown by the chain line in FIG.
In the vicinity of 39, the outer surface of the case body 36 and the lid
The step with the outer surface of 37 disappears and is flush,
From the body 36 to the flange 37 of the lid 37 _TwoThe tip is outside
No longer protrudes to the side. As a result, the seat back 2
The pad 19 and the third covering material 22 are deformed due to the weight of the worker
Or if they move, they will
J37_TwoHooked on hook 36₁... are hook engagement holes
37 ₁… It can solve the problem
You. Moreover, the opening edge 39 of the case body 36 is
Flange 37_TwoAnd projection 37_Three… Mate between and position
The outer surface of the case body 36 by the load.
Ensure that a step is formed between the lid 37 and the outer surface.
Indeed, it can be prevented.

As shown in FIGS. 8 and 16, the airbag module M includes an airbag 4, an inflator 32,
The airbag 4 includes a retainer 31, a side plate 33, a module case 35, bolts 14, 14, nuts 34, 34, and nuts 15, 15. A protector sheet 40 is integrally sewn to the base end of the airbag 4. The protector sheet 40 is made of, for example, a nylon cloth of the same material as the airbag 40. The inflator 32, the retainer 31, and the bolts 14, 14 are
The sub-assembly 41 is inserted into the inside of the airbag 4 from a slit 47 described later formed in the base end of the airbag 4.

Next, the structure of the airbag 4 and the protector sheet 40 will be described with reference to FIGS.

The airbag 4 is formed by folding a band-shaped base cloth 42 in two at a fold line F at an intermediate portion in the longitudinal direction, and superimposing a reinforcing cloth 43 on the inner surface on the base end side thereof. 43 is sewn with three sewing lines S ₁ , S ₂ and S ₃ , and is sewn with two sewing lines S ₄ and S ₅ extending in parallel on the upper edge and the lower edge of the doubled base cloth 42. Do it. The sewing lines S ₄ and S ₅ are sewn with the base cloth 42 turned upside down, and the sewn base cloth 42 is turned over via the slit 47.

The protector sheet 40 has a base portion 40 _1.
The after being sewn by the sewing line S ₆ in a folded state folded in two, part became the double is sewn together at superimposed to the proximal end sewing line S ₇ of the base fabric 42. The sewing line S ₆ of the protector sheet 40 is sewn with thick thread than the other sewing lines _{S 1 ~S 5, S 7 ~S} 12, thus sewing manufactured line S ₆ from the surface of the protector sheet 40 It is greatly raised (see FIGS. 4, 5 and 13).

As is apparent from FIGS. 9, 10 and 14, two vent holes 44 are formed near the fold line F at the tip of the airbag 4. Vent hole 4
Reference numerals 4 and 44 deviate slightly from the fold line F to the outside of the vehicle body (the side opposite to the center pillar and the door opposite to the occupant).
, And the high pressure gas discharged from the vent holes 44, 44 is designed not to hit the occupant.

As shown best in FIG. 14, a substantially circular patch 45 is superimposed on the back surface of the base cloth 42 so as to surround each vent hole 44, and sewing lines S ₈ and S _{8 are formed} .
Sewn at ₉ . FIG. 14 shows the state in which the base cloth 42 is turned upside down, and the backing cloth 4 by the sewing lines S ₈ and S _9.
The sewing of No. 5 is performed at a stage before the base cloth 42 is sewn on the sewing lines S ₄ and S ₅ . Extends as against overlap the end portion of the protrusion 45 ₁ folding lines F projecting from the outer periphery of the fabric 45, the end portion of the sewing line S _4, S ₅ sewing the upper and lower edges of the base fabric 42 is against connecting projections 45 ₁ of the fabric 45 after sewing together with the base fabric 42, the U-shape from the fold line F on the protrusion 45 ₁ caught outside.

As described above, when the sewing lines S ₄ and S ₅ are extended beyond the fold line F, a gap is generated in the base cloth 42 at the fold line F, and the inside and the outside of the airbag 4 communicate with each other. Can be eliminated, and undesired leakage of high-pressure gas can be reliably prevented. Moreover it is possible since it is configured the protrusion 45 ₁ by using a part of the patch cloth 45 to form the vent hole 44, contributing to a reduction in the number of components. Also, two sewing lines S ₄ , S
₅ since the connection to the U-shape against over projections 45 ₁ of the fabric 45, man-hours to be able sewing two sewing lines S _4, S ₅ and in one step can be reduced.

As shown in FIGS. 9, 12 and 15,
The inner surfaces of the base cloth 42 which is folded in two and opposed to each other are connected by tethers 46, 46. Proximal end of the tether 46 is folded back to cover the sewing line S ₁₀ after being sewn in an annular sewing line S ₁₀ of the base fabric 42, the tether became double 46 sewing line S together with the base fabric 42 It is further sewn at ₁₁ . Then each other tip of the two tethers 46, 46 are sewn by the sewing line S ₁₂ are superimposed. Sewing of the tether 46, 46 by sewing line S _10, S ₁₁ is performed before the step of sewing the base fabric 42 with the sewing line S _4, S _5,
The sewing and if tethers 46, 46 by sewing line S ₁₂ is performed base cloth 42 sewn in the sewing line S _4, S ₅ before returning table. When the airbag 4 is inflated, as shown in FIG. 12, the tethers 46, 46 extend linearly, thereby restricting the distance between the opposing portions of the base cloth 42 of the airbag 4 and controlling the airflow. The shape when the inflation of the bag 4 is completed can be adjusted.

As shown in FIGS. 13 and 16, at the base end of the airbag 4, the slit 47 is formed linearly so as to penetrate the base cloth 42 and the reinforcing cloth 43. On both ends of the two bolts 1
Two bolt holes 48, 48 through which the holes 4 and 14 pass are formed. As described above, the slit 47 penetrating the base cloth 42 and the reinforcing cloth 43 is for inserting the subassembly 41 into the airbag 4 and extends from the subassembly 41 inserted inside the airbag 4. The two bolts 14 are provided in the bolt holes 4 at both ends of the slit 47.
It protrudes out of the airbag 4 from 8,48.

Further, two linear pin holes 49, 49 through which two positioning pins 31 ₃ , 31 ₃ formed by cutting and raising the retainer 31 penetrate, are formed on the base cloth 42 and the reinforcing cloth 4.
3 is formed. By inserting the positioning pins 31 ₃ , 31 ₃ of the retainer 31 into the pin holes 49, 49, the sub-assembly 41 inserted into the airbag 4 is positioned so as not to be turned upside down.

On the base cloth 42 so as to cover the slit 47,
Base end 40 of protector sheet 40 to be superimposed₁
Are provided with bolt holes 48, 48 and pin holes of the airbag 4.
Bolt holes 50, 50 and pin holes 5 overlapping 49, 49
1, 51 are formed. In addition, protector seat 40
Wound around 360 ° around the folded airbag 4
Sometimes the base end 40 of the protector sheet 40₁Piled on
Tip 40 to be fitted _TwoThe base end 40₁Formed in
The bolt holes 50, 50 and the pin holes 51, 51
Bolt holes 52, 52 and pin holes 53, 53 are formed.
It is. The pin holes 49, 49 of the base cloth 42 and the reinforcing cloth 43
While it is formed in a straight line, the protector sheet
40, the pin holes 51, 51;
Holes 49, 49 are formed in a larger circle.

As is apparent from FIG. 13, the protector and the base end portion 40 ₁ and the distal end portion 40 ₂ of the sheet 40, four fracture portion formed in the narrow to easily broken by the load 54 55, 55 are connected. Protector sheet 40 near break portions 54, 54; 55, 55
Although of the distal end portion 40 ₂ the two bolt holes 52, 52 are formed, breaking portion 5 and its bolt holes 52 and 52
4, 54; 55, 55 are set as follows. That is, a straight line is drawn through the centers of the bolt holes 52, 52 in parallel with the longitudinal direction of the protector sheet 40, and is drawn through the centers of the breaks 54, 54; 55, 55 in parallel with the longitudinal direction of the protector sheet 40. When a straight line is drawn, the center of the bolt holes 52, 52
The center of the bolt holes 52, 52 deviates from the center of the bolt holes 52, 52 by a distance α in the direction perpendicular to the longitudinal direction.
5 is deviated by a distance β in a direction perpendicular to the longitudinal direction.

Next, an assembly process of the airbag module M will be described.

First, as shown in FIG. 16, after the protector sheet 40 is inverted from the chain line position to the solid line position in the direction of the arrow, the slit 47 penetrating the base cloth 42 and the reinforcing cloth 43 of the airbag 4 is opened, and the inflator is opened. The sub-assembly 41 in which the retainer 32, the retainer 31 and the bolts 14, 14 are integrated is inserted into the inside of the airbag 4 from the slit 47. Subsequently, the two bolts 14, 14 protruding from the retainer 31 of the subassembly 41 inserted into the airbag 4 are passed through the bolt holes 48, 48 formed at both ends of the slit 47 from the inside to the outside. Positioning pins 31 ₃ , 3 protruding from retainer 31
1 _3, is passed through pin holes 49 of the two linear extending through the backing 42 and the reinforcing cloth 43 of the air bag 4 from the inside to the outside.

At the time of assembling, the harness connected to the inflator 32 is detached from the inflator 32 in advance and stored inside the base cloth 42, and both ends thereof are slits 47 of the base cloth 42.
And it is made to protrude outside from the harness draw-out hole (not shown) of the base cloth 42. After connecting the inflator 32 to the base end of the harness projecting from the slit 47,
By inserting the inflator 32 from the slit 47 into the inside of the base cloth 42, the operation of pulling out the front end of the harness from the harness drawing hole to the outside can be easily performed.

Subsequently, the protector sheet 40 is moved to the position shown in FIG.
By returning the state to the state of FIG. 9, two bolt holes formed in the base end portion 40 ₁ of the protector sheet 40 5
0, 50 and the two pin holes 51, 51 are inserted into the bolts 14, 14, and the positioning pins 31 ₃ , 3 respectively.
Fitted to 1 _3. As a result, the base cloth 42 of the airbag 4
The slit 47 penetrating through the reinforcing cloth 43 is covered with the protector sheet 40 and closed. As described above, by using the protector sheet 40, the slit 47 of the airbag 4 can be closed without using a special closing member.

Subsequently, the airbag 4 is folded in a bellows shape from the distal end toward the proximal end, and the protector sheet 40 is wound around the outer periphery of the folded airbag approximately one turn. two bolt holes 52, 52 and two pin holes 53, 53 formed in the distal end portion 40 ₂ of, fitted to each bolt 14, 14 and the positioning pin 31 _3, 31 _3. As a result, the airbag 4 is wrapped in the protector sheet 40 and held in a folded state.

In this state, the two positioning pins 31 ₃ ,
31 ₃ are two linear pin holes 49, 49 of the airbag 4.
And visually confirm that the subassembly 41 is correctly assembled. At this time, the two linear pin hole proximal end of the protector sheet 40 portion to be overlapped doubly outside of 49 40 _first pin holes 51, 51,
The distal end portion 40 ₂ of the pin holes 53 and 53, since both are also formed on the larger circle than the linear of the pin hole 49, pin holes 51, 51 of its circular; subassembly through 53 41 can be easily checked (see FIG. 5).

The front end portion 40 of the protector sheet 40
When fitting the _second bolt holes 52, 52 on the bolt 14, 14, it is necessary to provide a strong pulling tension tip 40 ₂ of the protector sheet 40 to compress the airbag 4 folded. At this time, the tension protector sheet 40 of the base end portion 40 ₁ of four breaks 54,
54; 55, 55 is transmitted to the distal end portion 40 ₂ via, if the bolt holes 52, 52 of the distal end portion 40 ₂ breaks 5
4, 54; 55, 55,
Strong tension acts on the inner periphery of the bolt holes 52, 52 fitted to the bolts 14, 14, and the bolt holes 52, 52
There is a possibility that the protector sheet 40 may be loosened due to extension or deformation.

However, as is apparent from FIG. 13, according to the present embodiment, the bolt holes 52, 52 are offset from the break portions 54, 54; 55, 55 by the distance α or the distance β in the vertical direction. In addition, it is possible to prevent the occurrence of elongation or deformation due to the strong tension directly acting on the bolt holes 52, 52. As a result, the folded airbag 4 can be securely wrapped with the protector sheet 40 without looseness.

Subsequently, as shown in FIGS. 4 and 8, bolts 14 and 14 and positioning pins 31 ₃ and 31 ₃ are respectively formed in bolt holes 33 ₁ and 33 ₁ and pin holes 33 ₂ and 33 ₂ formed in the side plate 33. Then, nuts 34, 34 are screwed into the bolts 14, 14. as a result,
Since the airbag 4 and the protector sheet 40 are sandwiched between the retainer 31 and the side plate 33 and are firmly fixed, the base cloth 42 and the reinforcing cloth 4 of the airbag 4 are provided.
The slit 47 penetrating through the slit 3 can be more reliably closed to prevent leakage of high-pressure gas from the slit 47. In this state, the sewing line S ₆ protruding from the surface of the protector sheet 40 abuts on the edge of the side plate 33 (see FIGS. 4 and 5).

Subsequently, the airbag 4 wrapped in the protector sheet 40 is attached to the case body 3 of the module case 35.
6 and the hooks 36 ₁ .
₁ to engage the lid 37 to fix the lid 37 in the closed position. At this time, the bolts 14, 14 and the positioning pins 31 ₃ , 3
1 _3, a bolt hole 36 formed in the bottom surface of the case body 36
_3, 36 ₃ and the pin holes 36 _4, 36 loosely fitted to _four.

Subsequently, the airbag module M is fixed to the module mounting frame 12 by penetrating the bolts 14 and 14 into the module mounting frame 12 of the front seat S and screwing nuts 15 and 15 into the ends.
4 and 5, in a state where the airbag module M is fixed to the module mounting frame 12, the module case 35 made of synthetic resin does not contact the module mounting frame 12, and the airbag module M is Two sides of the metal module mounting frame 12
The metal nuts 34, 34; 15, 15 are fastened and fixed. At this time, if the synthetic resin module case 35 is sandwiched and tightened, the synthetic resin may be dented by the load and the nuts 34, 34; 15, 15 may be loosened. Since the fastening force does not act on the module case 35, the above problem can be solved.

In the event of a vehicle collision, the inflator 32
Generates gas, the airbag 4 inflates inside the module case 35. When the airbag 4 is inflated, tension acts on the protector sheet 40 wrapping the outer periphery thereof, so that the break portions 54, 54 of the protector sheet 40;
55, 55 is broken and the airbag 4 is in a state where it can be freely inflated.

Even if the pressure of the high-pressure gas supplied to the inside of the airbag 4 acts to displace the base end of the airbag 4 with respect to the retainer 31, as shown in FIGS. Since the sewing line S ₆ of the protector sheet 40 integral with the airbag 4 is in contact with the edge of the side plate 33 integral with the retainer 31, the sewing line S ₆ serves as a stopper to position the airbag 4. Not only can the displacement be prevented, but also the concentration of stress at the base end of the airbag 4 can be prevented. In addition, a special stopper is not required, which can contribute to a reduction in the number of parts.

When the pressure for inflating the airbag 4 acts on the inner surface of the lid 37 of the module case 35, the hook 3
6 ₁ are disengaged from the hook engaging holes 37 ₁ ..., And the lid 37 is rotated around the hinge portion 38 (see the chain line in FIGS. 4 and 5), and the case body 36 is opened.

As apparent from FIG. 7A, the lid 3
7 each hook engagement hole 37 ₁Is roughly rectangular
The long side of which is along the outer edge of the lid 37
It extends in the direction. Outer peripheral edge of lid 37 and hook engaging hole 3
7₁Elongate bridge part 37 located between the long sides_Fourof
Hook engaging holes 37 facing both ends₁Two corners a and b
One corner a has a relatively large radius of curvature.
It is formed in a smooth arc shape, but the other corner
b has a relatively small radius of curvature and is sharply pointed.

Therefore, when the airbag 4 is inflated, the hook 3
When the lid 37 is opened from the case body 36 because the hook engagement holes 37 ₁ are disengaged from 6 ₁ ..., Even if the corners a and b are broken, stress is concentrated because they are sharp and sharp. And only one corner a is not broken. Thus, both corner portions a, b that bridge portion 37 ₄ cutaway together is scattered is prevented.

[0044] FIG. 7 (b) shows another embodiment of the hook engagement hole 37 _1. In this embodiment, the hook engagement holes 3
7 ₁ of the two corners a, of b, and increasing the thickness of the bridge portion 37 ₄ facing one of its corners a, its other corners b
The thickness of the bridge portion 37 ₄ facing the one in which a thinner.
Also according to this embodiment, by breaking the thinner corner b first to avoid breaking the thicker corner a,
Both corners a, b of scatters bridge portion 37 ₄ are broken together can be prevented.

In FIG. 2, when the pressure for opening the lid 37 is transmitted to the third covering material 22 of the seat back 2, the sewing portion 25 is broken, and the second covering material 21 and the third covering material 22 are separated. The airbag 4 that has passed through the gap deploys obliquely forward along the center pillar and the front door to restrain the right side of the occupant.

When the airbag 4 is inflated, as shown in FIG. 12, the tethers 46 extend linearly and regulate the width of the airbag 4 in the left-right direction. At this time, the tether 46,
The base end portion of the airbag 4 is folded in two to form the base cloth 4 of the airbag 4.
Whereas superimposed 2 with a 3-ply and are sewn with the sewing line S _11, the sewing line S ₁₂ tip each other of the tethers 46, 46 are superimposed as two-ply
In being sewn, moreover the width γ of the sewing line S ₁₁ of the base end portion of the tether 46 is set larger than the width δ of the sewing line S ₁₂ of the front end portion of the tether 46, 46 (FIG. 15 reference).

Since the strength of the sewing lines S ₁₁ and S _{12 formed} of closed curves is proportional to the size of the area surrounded by the sewing lines S ₁₁ and S ₁₂ , the base ends of the tethers 46 and 46 are attached to the base cloth 42.
Strength of the sewing line S ₁₁ to be sewn is higher than the strength of the sewing line S ₁₂ sewing the tip each other of the tethers 46, 46, even if the tethers 46, 46 is broken by any chance tension, sewing line S ₁₁ Is not broken and the sewing line S
₁₂ or the tethers 46, 46 themselves will break. Accordingly, leakage of high-pressure gas can be reliably prevented from occurring base fabric 42 of the airbag 4 with the sewing line S ₁₁ is broken. Moreover, since only the base ends of the tethers 46, 46 are folded in two and no special reinforcing cloth is required, an increase in the number of parts and an increase in cost can be suppressed.

Although the embodiments of the present invention have been described in detail, various design changes can be made in the present invention without departing from the gist thereof.

For example, in the embodiment, the airbag device for side collision accommodated in the front seat S has been exemplified. However, the present invention is provided in an airbag device for a driver seat provided in a steering wheel or an instrument panel. The present invention can also be applied to a passenger-side airbag device provided. The proximal end of the protector sheet 40 in Example 40 ₁ and the tip portion 40 _2, respectively bolt holes 50, 5
0; 52, 52 but are formed, by changing the mounting position of the protector sheet 40 to the base fabric 42 of the airbag 4, it is also possible to omit the bolt holes 50, 50 of the base end portion 40 ₁ . Further, although the protector sheet 40 is made of cloth in the embodiment, it may be made of a synthetic resin sheet or paper.

[0050]

As described above, according to the first aspect of the present invention, since the bolt holes and the break portions of the protector sheet are arranged so as to be deviated in the direction perpendicular to the longitudinal direction of the protector sheet, the protector sheet is airbag. When the bolt is wound around the outer periphery of the bolt and the bolt hole is locked to the bolt, the tension at the base end of the protector sheet does not directly act on the inner peripheral surface of the bolt hole. As a result, the bolt hole of the protector sheet does not expand or deform, and the protector sheet is prevented from being loosened and the folded state of the airbag is prevented from being collapsed.

[Brief description of the drawings]

FIG. 1 is a perspective view of a seat provided with an airbag device.

FIG. 2 is an enlarged sectional view taken along line 2-2 of FIG. 1;

FIG. 3 is a view in the direction of arrows in FIG. 2;

FIG. 4 is a sectional view taken along line 4-4 in FIG. 3;

FIG. 5 is a sectional view taken along line 5-5 in FIG. 3;

FIG. 6 is a sectional view taken along line 6-6 in FIG. 3;

FIG. 7 is an enlarged view of part 7 of FIG.

FIG. 8 is an exploded perspective view of the airbag module.

9 is a view in the direction of arrow 9 in FIG. 8;

FIG. 10 is a view in the direction of arrow 10 in FIG. 8;

FIG. 11 is a sectional view taken along line 11-11 of FIG. 9;

FIG. 12 is a sectional view taken along line 12-12 of FIG. 9;

FIG. 13 is an enlarged view of part 13 of FIG.

FIG. 14 is an enlarged view of part 14 of FIG. 9;

FIG. 15 is an enlarged view of a portion 15 of FIG. 9;

FIG. 16 is an explanatory view of an operation at the time of assembling the airbag module.

[Explanation of symbols]

Reference Signs List 4 airbag 12 module mounting frame (frame) 14 bolt 32 inflator 40 protector sheet 40 ₁ base end 40 ₂ front end 52 bolt hole 54 break part 55 break part

Claims (1)

[Claims] An airbag (4), and an inflator (3) housed inside the airbag (4).
2); a substantially band-shaped protector sheet (40) wound around the outer periphery of the folded airbag (4) to hold the airbag (4) in a folded state; and an inflator (32) together with the airbag (4). A bolt (14) extending from the inflator (32) to the outside through the airbag (4) to be fixed to the frame (12).
If, now provided with the protector sheet (40), together with the bolt holes (52) are formed to be locked the bolt (14) in the longitudinal direction of the distal end portion (40 _2), the bolt holes (5
The airbag device, wherein a break portion (54, 55) that is broken by a tension acting upon inflation of the airbag (4) is formed at a position closer to the base end (40 ₁ ) in the longitudinal direction than 2), Hole (52) and said break (54, 55)
The airbag device is disposed so as to be deviated in a direction perpendicular to the longitudinal direction of the protector seat (40).