JP3467114B2 - Airbag device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an airbag device in which an airbag is folded and stored. 2. Description of the Related Art Conventionally, an airbag device provided on a steering wheel of an automobile has been used. This airbag device includes a metal base plate attached to a steering wheel body, and an inflator that injects gas, an airbag that is inflated by the gas, and a cover that covers the airbag are attached to the base plate. ing. And the airbag is
It is stored inside the cover body in a small folded state,
In the event of an automobile collision or the like, the cover expands due to the pressure of the gas injected from the inflator and is opened to the front of the occupant. [0003] However, since the airbag is housed in a small folded state, it has an effect of spontaneously restoring its shape. In particular, the restoring force of the cover body is promoted by heat or the like, and the airbag is inflated. Then, this airbag presses the cover body from the inside, the cover body expands,
There is a problem that the appearance is deteriorated, for example, a step such as a tear line is exposed. Further, when the horn switch is provided on the back side of the cover, the airbag and the horn switch are pressed from the inside, which causes a problem that the horn switch may malfunction. In this regard, for example, an airbag device described in Japanese Utility Model Publication No. 54-3486 is known. In this airbag device, a belt-shaped member whose both ends are fixed to a base plate together with the airbag is used, and the airbag is tightened by the belt-shaped member to maintain a folded shape, A diamond-shaped notch is formed in the center of the member, and when the airbag is deployed, the notch is broken from a break near the notch. However, the above-mentioned Japanese Utility Model Publication No. 54-3486.
In the configuration described in Japanese Patent Application Laid-Open Publication No. H11-133, in the initial stage of deployment of the airbag, the belt-shaped member is difficult to break until the vicinity of the broken portion of the belt-shaped member expands, so that it is difficult to quickly deploy the airbag. Have a problem. [0006] As described above, in the configuration in which the airbag is folded and stored in a small size, the cover body is restored by the action of spontaneously restoring the shape, particularly by heat or the like. When power is encouraged and tries to expand,
This airbag presses the cover body from the inside, causing problems such as the cover body swelling, a step such as a tear line being exposed, and the appearance being deteriorated. Further, when the horn switch is provided on the back side of the cover, the airbag and the horn switch are pressed from the inside, which causes a problem that the horn switch may malfunction. In the configuration described in Japanese Utility Model Publication No. 54-3486, the belt-shaped member is not easily broken until the vicinity of the broken portion of the belt-shaped member is inflated in the initial stage of the deployment of the airbag. There is a problem that it is difficult to deploy. SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an airbag device which can stably hold a folded airbag and smoothly deploy the airbag. . [0008] air bag device SUMMARY OF THE INVENTION The present invention, in the mounting member, and the airbag, the airbag device fitted with a cover body covering the air bag, before
The airbag is folded into a band and then on both sides.
Rolled towards the center, folded end
Are folded in a state where they are close to each other at the center, and are located inside the cover body, cover the folded and stored airbag, and along the portion where the ends of the folded airbag are brought close to each other. And a wrapping member provided with a rupturable portion that can be ruptured. According to the airbag device of the present invention, the airbag comprises:
Covered by the cover body while being held in the folded shape by the wrapping member, even if the airbag tries to recover by itself, the shape is stably held and does not affect the appearance of the cover body . And, since the wrapping member is provided with a breakable portion which can be broken along a portion where the folded end portions of the airbag are brought close to each other, when the airbag is inflated and deployed , the folded portion on both sides is provided.
And the tension is applied to the broken part.
Wari, a force to the air bag is get up is concentrated in the fracture portion, wrapping member is quickly broken by the breaking portion. An embodiment of an airbag device according to the present invention will be described below with reference to the drawings. In FIG. 2, reference numeral 11 denotes a steering wheel of an automobile. The steering wheel 11 includes a steering wheel body 12 and the steering wheel body.
An airbag device 14 mounted on the upper side of the occupant 12 is provided. The steering wheel body 12 is
It comprises an annular rim 15, a boss 16 located inside the rim 15, and a plurality of spokes 17 connecting the rim 15 and the boss 16. A boss fitted to a steering shaft (not shown) is arranged below the steering wheel body 12 on the vehicle body side, and a boss plate is fixed to the boss by welding or the like. The core of the spoke portion 17 is connected to the boss plate, and the core of the rim portion 15 is connected to the core of the spoke portion 17. Further, a skin portion 18 made of a soft synthetic resin or the like is formed on the outer peripheral portion of the core metal of the rim portion 15 and the outer peripheral portion of the spoke metal of the core metal on the rim portion 15 side of the spoke portion 17. As shown in FIGS. 1, 3 and 4, the airbag device 14 has a metal base plate 21 as a member to be mounted, and this base plate 21 is attached to a boss plate of the steering wheel body 12. It can be attached via a bracket or the like. And
The base plate 21 has an upper plate portion 21a having a substantially flat shape.
And a peripheral wall portion 21b bent downward from the peripheral portion of the upper plate portion 21a. And the upper plate part 21
a, a circular inflator mounting hole 21c is formed,
A substantially cylindrical inflator 22 that fits into the inflator mounting hole 21c from below and injects gas is mounted. Further, on the upper surface of the upper plate portion 21a, a bag-shaped airbag 24 is provided so as to cover the upper side of the inflator 22.
Is installed in a folded state. As shown in FIG. 5, the airbag 24 is formed in a bag shape by butting two circular cloth materials up and down and sewing the outer peripheral portions together. In addition, the lower fabric material has an inflator insertion port 24a fitted to the inflator 22.
And a pair of vent holes 24b for discharging the filled gas are formed.
Then, as shown in FIG. 6, the airbag 24 has a front side portion on the rear side, a rear side portion on the front side, and a base plate.
As shown in FIGS. 1, 4 and 7, by being folded into a belt shape slightly smaller than the front-rear dimension of 21, and then wound so that both sides are wound toward the center side. The ends 24c are folded small with their central portions close to each other. Furthermore, the air bag 24, as shown in FIGS. 3 and 4, with the annular retainer 26, inflation
Upper plate 21 in the vicinity of the regulator insertion hole 24a is the base plate 21
a, and a bolt 27 protruding downward from the retainer 26 is attached to the airbag 24 and the base plate.
The airbag 24 is fixed to the base plate 21 together with the inflator 22 by inserting the nut 21 from the lower surface of the flange portion 22a of the inflator 22 through the flange portion 22a of the inflator 22. Further, a plurality of through holes 21d for rivets and a plurality of through holes 21e for engagement are formed in the peripheral wall portion 21b of the base plate 21, and bracket mounting portions 21f are respectively formed in the peripheral wall portions 21b on both sides. I have. Further, the folded airbag 24 is shown in FIG.
As shown in the figures, the upper surface is covered by a sheet-shaped wrapping member 31 and the shape is maintained. The wrapping member 31 is made of synthetic paper, paper, cloth, non-woven fabric, or a resin sheet obtained by adding or impregnating a resin after or during the manufacturing process thereof by a method such as impregnation, blending or coating, or a resin sheet such as polyester. In this embodiment, the synthetic paper "Tyvek"
(Product name) is used. As shown in FIGS. 3 and 8, the wrapping member 31 has a main body 31a that comes into contact with the folded airbag 24, and both ends of the main body 31a are slightly smaller than the main body 31a. Are formed with mounting portions 31b, 31b having a small width. A tear line 31c is formed in the center of the main body 31a in the longitudinal direction as a rupture portion formed of a slit or the like that is more fragile than other portions, over the entire length of the main body 31a in the width direction. Each mounting portion 31b is formed with a plurality of rivet through holes 31d each having a circular hole shape. The wrapping member 31 is attached to each of the mounting portions 31b so that the main body 31a wraps the airbag 24 in a state where the airbag 24 is folded into a predetermined shape.
To the base plate 21 using double-sided tape,
They are temporarily fixed. Further, as shown in FIGS. 3 and 4, a cover body 34 is attached to the base plate 21 so as to further cover the airbag 24 covered by the wrapping member 31. The cover body 34 is integrally formed of a synthetic resin such as a thermoplastic elastomer, and is formed integrally with the boss portion 16 and the spoke portion of the steering wheel body 12.
It has an upper plate portion 36 that covers a part of 17, and a substantially rectangular tubular mounting wall portion 37 protruding downward from the back surface of the upper plate portion 36. The mounting wall portion 37 is formed with a rivet through hole 37a having a circular hole shape, and has a plurality of engaging projections (not shown) projecting inward. On the back side of the upper plate portion 36 of the cover body 34, a tear line 44, which is weaker than the other portions of the upper plate portion 36, is formed in a substantially H-shaped plane and is recessed. A pair of front and rear door pieces that expand forward and backward when inflated are formed. In the cover body 34, the mounting wall portion 37 is fitted to the outside of the peripheral wall portion 21b of the base plate 21, and the engaging projection protruding from the mounting wall portion 37 is formed on the peripheral wall portion 21b. The mounting wall 37 and the peripheral wall 21b are fixed to each other by the rivets 61 which are engaged with the joint through holes 21e and are inserted through the rivet through holes 37a of the mounting wall 37 and the rivet through holes 21d of the peripheral wall 21b. And is fixed to the base plate 21. In this state, the mounting wall of the cover body 34 is
The mounting portion 31b of the wrapping member 31 is sandwiched between the base plate 21 and the peripheral wall portion 21b of the base plate 21, and the rivet 61 is inserted into the rivet through hole 31d of the wrapping member 31, so that the wrapping member 31 is firmly fixed. When a vehicle collides, the igniter of the inflator 22 is activated by a signal from a collision diagnosis unit (not shown), and the charged propellant is burned to form a peripheral surface of the inflator 22. Nitrogen gas or the like is rapidly injected into the airbag 24 from the gas injection holes 22b. Then, as shown in FIG. 9, the folded airbag 24 starts inflating, and ends 24c, 24c of the folded portions on both sides are respectively indicated by arrows A,
Trying to get up in the A direction. In this state, the airbag 24 is connected to the tear line 31c of the wrapping member 31.
Although it is not in direct contact with the airbag 24, tension is applied to the tear line 31c in the directions indicated by the arrows B and B so that the tear line 31c is supported by the top surface portions 24d and 24d of the folded airbag 24. Ends 24c, 24 of the airbag 24
The elastic tensile strength due to the application of the tension of the wrapping member 31 is all concentrated on the tear line 31c while both ends are supported between them. Therefore, as shown in FIG. 10, when the inflator 22 is activated, the wrapping member 31 is instantaneously moved to the tear line 31.
c, and the upper plate 36 of the cover body 34 is cleaved along the tear line 44 to form a pair of front and rear door pieces, and these door pieces rotate back and forth. A projecting opening of the airbag 24 is formed, and the airbag 24 inflates toward the front of the occupant from the projecting opening. According to the present embodiment, the wrapping member 31 located inside the cover body 34 covers the folded and stored airbag 24. Therefore, even if the airbag 24 attempts to recover by itself, it is stable. The folded shape can be maintained, and the appearance of the cover body 34 can be favorably maintained. The airbag 24 is folded so that the ends 24c, 24c abut each other, and a wrapping member is provided.
31 has an end 24c obtained by folding the airbag 24,
Since the tear line 31c is provided along 24c, the airbag 2
When the airbag 24 is inflated and deployed, the force of the airbag 24 to rise is concentrated on the tear line 31c, the wrapping member 31 is instantaneously broken at the tear line 31c, and the airbag 24 is quickly and smoothly inflated and deployed. be able to. The wrapping member 31 is a base plate.
The heat generated by the inflator 22 is transferred from the base plate 21 to the cover
Transmission to the mounting wall portion 37 of the cover 34 can be suppressed, and thermal influence on the cover body 34 can be reduced. Further, since the wrapping member 31 covers almost the entire upper surface of the folded and stored airbag 24, the folded shape of the airbag 24 can be stably and reliably held. Then, the wrapping member 31 is made of paper, in particular,
Since it is made of synthetic paper, the heat insulating effect can be enhanced, and the addition of the wrapping member 31 hardly increases the weight . [0028] In addition, in the above example, the wrapping member
The tear line 31c has a longitudinal direction in the front-rear direction, a central portion of the tear line 44 of the cover body 34 has a longitudinal direction on both sides, and the tear lines 31c and 44 are substantially orthogonal to each other at a substantially central portion of the upper plate portion 36 of the cover body 34. However, the tear lines 31c and 44 may be formed in parallel with each other. Further, the airbag 24 may be folded, for example, so as to form four end portions, and may be combined with a wrapping member having a cross-shaped tear line formed at the center of the main body. In the above embodiment, the wrapping member
The wrapping member 31 is temporarily fixed to the base plate 21 using a double-sided tape, for example, by bonding, welding, sewing, or the like.
It can also be attached to such as. Then, the base plate 21 may be cut and raised in a key shape to form an engaging portion, and the mounting portion 31b may be engaged with the engaging portion, and the mounting portion 31b of the wrapping member 31 may be formed in a bag shape. Then, it may be locked to the base plate 21 or the cover body 34 or the like. According to the airbag device of the present invention, since the airbag is covered with the cover while being held in a shape folded by the wrapping member, even if the airbag attempts to recover by itself, The folded shape can be stably maintained, and the appearance of the cover body can be favorably maintained. The wrapping member has a breakable portion that can be broken along a portion where the folded ends of the airbag are brought close to each other, so that when the airbag is inflated and deployed, it is folded on both sides.
Expand and break so that the end of the folded part rises up
The tension is applied to the portion, and the force of the airbag to rise is concentrated on the break portion, the wrapping member is rapidly broken at the break portion, and the airbag can be inflated and deployed quickly and smoothly.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view showing an embodiment of an airbag device of the present invention. FIG. 2 is a plan view of a steering wheel provided with the airbag device. FIG. 3 is an exploded perspective view of the airbag device. FIG. 4 is a cross-sectional view of the airbag device. FIG. 5 is a plan view of the airbag device of the same airbag device in a deployed state. FIG. 6 is an explanatory diagram of an airbag folding operation of the airbag device. FIG. 7 is an explanatory diagram of a folding operation of the airbag of the airbag device. FIG. 8 is a development view of a wrapping member of the airbag device. FIG. 9 is an explanatory diagram of an operation of deploying the airbag of the airbag device. FIG. 10 is an explanatory diagram of an operation of deploying the airbag of the airbag device . [Description of Signs] 14 Airbag device 21 Base plate 24 as a member to be attached 24 Airbag 24c End 31 Lapping member 31c Tear line 34 as a breakage part Cover body

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-7-132789 (JP, A) JP-A-4-293642 (JP, A) JP-A-6-156176 (JP, A) Jikken Sho 54- 3486 (JP, Y1) European Patent Application Publication 622276 (EP, A1) German Patent Application Publication No. 4137691 (DE, A1) Registered Utility Model 3011543 (JP, U) Registered Utility Model 3016637 (JP, U) (58) Field surveyed (Int. Cl. ⁷ , DB name) B60R 21/20

Claims (1)

(57) [Claim 1] In an airbag device in which an airbag and a cover body covering the airbag are attached to a member to be attached, the airbag is folded in a belt shape, , Both sides
To the center side, and the folded end
The parts are folded in a state where they are close to each other at the center, and are located inside the cover body, cover the airbag that is folded and housed, and a part where the ends where the airbags are folded are brought close to each other. An airbag device comprising a wrapping member provided with a breakable portion that can be broken along.