JP5346646B2 - Airbag device for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vehicular airbag device capable of enhancing the designability, smoothly breaking an airbag lid along a scheduled breaking line, and rapidly deploying an airbag. <P>SOLUTION: In the vehicular airbag device, an airbag lid 21 covering a surface skin 43 and an airbag body stored inside the airbag lid 21 in a folded state are provided on a resin-made cover body, gas is introduced in the airbag body from an inflator connected to the airbag body, the airbag lid 21 is broken by the inflating airbag body, and the airbag lid 21 is divided into and deployed into a plurality of doors 60-62. Tear lines 55-58 for demarcating the airbag lid 21 into the plurality of doors 60-62 are formed in the airbag lid 21. A stitch pattern P is formed on the surface skin 43 on an outer area from at least the upper door 60 out of the plurality of doors 60-62. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to a vehicle airbag device.

  The vehicle airbag device includes an airbag stored in a folded state inside a hub portion of a steering wheel, and an airbag grid that covers the airbag. The air grid is composed of a resin cover and a skin made of natural leather or synthetic leather and covering the surface of the cover. In a vehicle airbag device, gas is supplied into an airbag from an inflator connected to the airbag and the airbag is inflated, so that pressure acts from the airbag toward the airbag grid, and the airbag grid is broken. The As a result, the airbag is deployed from the opening portion of the airbag grid into the vehicle interior.

  In the above-described vehicle airbag device, a tear line that is a planned cutting line is formed in the airbag grid in order to promote the breakage of the airbag grid and smoothly deploy the airbag (for example, a patent) Reference 1). The tear line has a groove shape formed along the back surface of the cover body, and is formed, for example, in a substantially H shape along the surface direction of the airbag grid.

JP 2005-145329 A

  By the way, in order to improve the design of the airbag grid and the like, the pattern of stitches (stitches) or the like may be applied to the front surface of the airbag by sewing the skin with a thread or the like. In this case, the stitch pattern is arranged so as to overlap the tear line formed on the cover body.

  However, when the stitch is arranged on the tear line, when the airbag grid is broken, the stitch may interfere with the break line (the tear line) of the airbag grid and may affect the breaking behavior of the airbag grid. For example, when a stitch pattern is formed, the strength of the epidermis is improved at the stitch pattern forming portion as compared with other portions. Therefore, the break of the air grid is blocked by the stitch pattern, and the air grid is not smoothly broken, or there is a shift between the tear line that is the planned break line and the actual break line, and the air grid is formed in a desired shape. There is a possibility that it cannot be broken. As a result, the airbag cannot be deployed quickly, and the deployment performance may be degraded.

  Therefore, the present invention has been made in view of the above-described problems, and after improving the designability, the airbag grid can be smoothly broken along the planned breaking line to quickly deploy the airbag. An object of the present invention is to provide a vehicular airbag device.

In order to solve the above-described problem, the vehicle airbag device of the present invention is formed by covering a resinous cover body (for example, the cover body 42 in the embodiment) with a skin (for example, the skin 43 in the embodiment). An airbag grid (for example, the airbag grid 21 in the embodiment), and an airbag body (for example, the airbag body 37 in the embodiment) stored in a folded state inside the airbag grid, the airbag body A gas is introduced into the airbag body from an inflator connected to the airbag (for example, the inflator 36 in the embodiment), the airbag grid is broken by the airbag body that is inflated, and the airbag grid is connected to a plurality of doors ( For example, a vehicle configured to be divided and deployed in each of the doors 60 to 62 in the embodiment. An airbag device, wherein the airbag lid, the is breakable line formed defining the airbag lid to said plurality of doors, the on epidermis, at least main door (e.g., implementation of the plurality of doors The stitch portion (for example, the stitch pattern P in the embodiment) is formed in the outer region from the upper door 60) in the form, and the stitch portion is a door different from the main door (for example, the implementation) among the plurality of doors. It is substantially perpendicular to the planned break line defining the lower doors 61, 62) in the form, and the intersection portion with the planned break line is broken when the different doors are developed .

According to the present invention, since the stitch portion is disposed at least outside the main door, at the time of breaking the airbag grid, it is possible to prevent interference between the planned break line constituting the main door and the stitch portion. it can.
Therefore, even when the stitch portion is formed on the airbag grid, at least the influence of the plurality of doors on the deployment operation of the main door is reduced, and each door is smoothly broken along each planned break line. be able to. Therefore, it is possible to realize a stable airbag deployment performance while improving the design of the airbag grid.

Further, the extending direction of the extending direction and the stitch part of the fracture will line that is substantially perpendicular, at the intersection of these breakable lines and stitch portion, stitch part shear force is stitched part is cutting action It becomes easy to be done. Therefore, the break of the airbag grid is not blocked by the stitch portion, and the airbag grid can be smoothly broken along the desired planned break line.
Therefore, even when the stitch portion is formed on the airbag grid, the deployment performance of the airbag can be maintained, so that the layout property of the stitch portion can be improved and the design property can be improved.

According to the present invention, since the stitch portion is disposed at least outside the main door, at the time of breaking the airbag grid, it is possible to prevent interference between the planned break line constituting the main door and the stitch portion. it can.
Therefore, even when the stitch portion is formed on the airbag grid, at least the influence of the plurality of doors on the deployment operation of the main door is reduced, and each door is smoothly broken along each planned break line. be able to. Therefore, it is possible to realize a stable airbag deployment performance while improving the design of the airbag grid.

It is a front view of a steering wheel. It is a disassembled perspective view of a steering wheel. It is sectional drawing which follows the AA line of FIG. It is a top view (front view) of an airbag grid. It is a top view (rear view) of an airbag grid.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the present application, the central axis direction of the steering wheel (the axial direction of the steering shaft) is the X direction (the rear side of the vehicle is the + X direction), the left and right direction of the vehicle is the Y direction, and the direction orthogonal to the XY direction is the Z direction (the upper direction of the vehicle is + Z Direction). In addition, the description will be made on the assumption that the driver side of the steering wheel is the front side (front side) and the opposite side is the back side (back side). In the following description, the radial direction is the radial direction (YZ plane) of the steering wheel, and the circumferential direction is the circumferential direction of the steering wheel.

(Steering wheel)
FIG. 1 is a front view of the steering wheel 10, and FIG. 2 is an exploded perspective view of the steering wheel 10.
As shown in FIGS. 1 and 2, the steering wheel 10 is rotatably supported by a steering shaft 15 (see FIG. 3), and includes a peripheral rim portion 11, a central hub portion 12, and both. Spoke portions 16 and 17 to be connected are provided. The spoke portions 16 and 17 include a pair of first spoke portions 16 and 16 extending from the hub portion 12 in the ± Y direction, and a second spoke portion 17 extending from the hub portion 12 in the −Z direction.

  The rim portion 11 is formed in an annular shape. In addition, an indicator 19 whose lighting state changes according to the engine speed or the like is provided at the top of the rim portion 11.

The steering wheel 10 is provided with various vehicle switches. As a vehicle switch, a switch group 14 such as an air conditioner operation switch or an in-vehicle telephone operation switch is provided between the first spoke portions 16 and along the peripheral edge portion of the lower half portion of the hub portion 12.
In addition, a paddle switch 40 for performing a gear shifting operation of the vehicle is provided as a vehicle switch. As the paddle switch 40, a downshift switch 40a for performing a downshift operation and a upshift switch 40b for performing an upshift operation are provided. The pair of paddle switches 40 are fixed to the back side of the pair of first spoke portions 16. Although not shown, the various vehicle switches and the electrical unit for controlling the driving of the indicator 19 are provided inside the hub portion 12 or on the back side of the switch group 14.

FIG. 3 is a cross-sectional view taken along the line AA in FIG. 1, and FIG. 4 is a plan view (front view) of the airbag grid 21.
As shown in FIGS. 2 to 4, the hub portion 12 has an inverted triangular shape in plan view arranged in the −X direction from the rim portion 11. The hub portion 12 is attached to the steering shaft 15 and has a bracket 20 having an opening toward the front surface (occupant side) of the steering wheel 10 and the above-described airbag grid 21 provided to close the opening of the bracket 20. And an airbag 22 is mounted in an inner space surrounded by the bracket 20 and the airbag grid 21. The airbag grid 21 and the airbag 22 constitute the airbag device 23 of the present embodiment.

  As shown in FIG. 3, the airbag 22 is fixed to a retainer 35 that extends radially inward from the opening edge of the bracket 20 in a state where the front surface is directed. Specifically, the airbag 22 includes an inflator 36 fixed to the retainer 35, and an airbag that is folded in a plurality of stages toward the front side of the inflator 36 with the end portion locked to the retainer 35. It has a main body 37 and a control unit (not shown) for determining the operation of the inflator 36.

  As shown in FIGS. 2 to 4, the airbag grid 21 is a bowl-shaped member that is formed in an inverted triangle shape in a plan view and bulges from the outer edge side to the center portion in a sectional view. Specifically, the airbag grid 21 includes a top plate portion 25 that curves toward the back side from the center to the outside in the plane direction, and the top plate portion 25 from the outside of the top plate portion 25 to the outer peripheral edge of the airbag grid 21. And an upper wall portion 26, a lower wall portion 27, and a pair of side wall portions 28 formed continuously with the upper wall portion 26 and the lower wall portion 27. It consists of and. Each wall part 26-28 bulges in the state curved toward the top-plate part 25 from the outer peripheral part.

  A first ridge line portion 30 formed between the top plate portion 25 and the lower wall portion 27 and both side wall portions 28 in the surface direction of the airbag grid 21 so as to surround the upper grid from the both sides to the lower portion. The 2nd ridgeline part 31 arrange | positioned inside the 1st ridgeline part 30 is formed. Therefore, the lower wall portion 27 and both side wall portions 28 of the airbag grid 21 are slightly bent at the ridge line portions 30 and 31.

FIG. 5 is a plan view (rear view) of the airbag grid 21.
As shown in FIGS. 3 and 5, the air grid 21 includes a cover body 42 that configures the external shape of the air grid 21 and a skin 43 that covers the entire surface (front surface) of the cover body 42. .
The cover body 42 is a bowl-shaped member made of a resin material, and an outer frame portion 44 that extends along the axial direction (−X direction) is integrally formed on the outer peripheral side thereof. The outer frame portion 44 is formed over the entire circumference in the circumferential direction of the cover body 42, and the distal end portion (end portion on the −X direction side) of the outer frame portion 44 is attached to the retainer 35. An air bag grid 21 is attached to the bracket 20.

The skin 43 is made of natural leather, synthetic leather, or the like, and is attached to the surface of the cover body 42. Then, the end portion of the skin 43 is folded back toward the inside of the cover body 42 at the peripheral edge portion of the cover body 42 and attached to the back surface of the cover body 42. Further, a stitch pattern (stitch portion) P is formed in a region between the first ridge line portion 30 and the second ridge line portion 31 in the skin 43 so as to surround the side wall portion 28 to the lower wall portion 27 of the airbag grid 21. Has been. The stitch pattern P is obtained by sewing the outer skin 43 with a thread or the like, and is arranged along the ridge lines 30 and 31.
Note that the stitch pattern P may be applied to join the ends of the plurality of skins 43 in accordance with the outer surface shape of the cover body 42, or may be applied simply as a pattern to one skin 43. . In the present embodiment, the cover body 42 is covered with a single skin 43, and a stitch pattern P is formed on the skin 43. In any case, the design can be improved by forming the stitch pattern P on the front surface of the airbag grid 21 along the outer surface shape of the airbag grid 21.

  Here, as shown in FIGS. 3 to 5, the cover body 42 is formed with a plurality of tear lines 50 serving as planned break lines for promoting breakage of the air grid 21. Each tear line 50 is a V-shaped groove 51 that is cut out from the back surface side of the cover body 42 along the thickness direction of the cover body 42. Further, the tear line 50 of the present embodiment is formed with a plurality of ribs 52 extending between the grooves 51 along the extending direction of the tear line 50. Thus, the strength of the tear line 50 can be adjusted by forming the rib 52 in the groove 51.

  Each tear line 50 includes a first tear line 55 extending along the Y direction on the back surface of the cover body 42 in the center portion in the Z direction of the top plate portion 25, and extending in the Z direction on both sides of the top plate portion 25. A pair of existing second tear lines 56, a third tear line 57 formed so as to surround the lower wall portion 27, and a fourth tear line 58 connecting the first tear line 55 and the third tear line 57 are configured. Yes. In the following description, when there is no need to distinguish these tear lines 55 to 58, the respective tear lines 55 to 58 are collectively referred to as a tear line 50.

Specifically, both ends of the first tear line 55 extend along the Y direction, and are curved downward (−Z direction) from both ends to the center.
Each second tear line 56 is orthogonal to both ends of the first tear line 55 at the center, while the upper end extends in a direction facing each other and the lower end extends in the opposite direction. .
The third tear line 57 extends along the Y direction at the center portion, and both end portions extend downward.
The fourth tear line 58 extends downward from the central portion in the extending direction of the first tear line 55 and is orthogonal to the central portion in the extending direction of the third tear line 57.

That is, the airbag grid 21 is defined vertically by the first tear line 55, and the defined lower half is further defined horizontally by the fourth tear line 58.
The upper half region of the airbag grid 21 defined by the first tear line 55 and each second tear line 56 is pushed upward by the airbag 22 when the airbag body 37 is inflated, and is bent upward. The door (main door) 60 is comprised (refer the dashed line in FIG. 3). Further, in the lower half of the airbag grid 21, a pair of lower doors in which regions surrounded by the first tear line 55, the second tear line 56, the third tear line 57, and the fourth tear line 58 are bent toward the left and right sides, respectively. (Doors) 61 and 62 are configured (see the chain line in FIG. 3).

  Here, the portion excluding the doors 60 to 62 described above in the cover body 42, that is, the outer region of the doors 60 to 62 is not opened even when the airbag 22 is deployed, and the remaining portion 65 remains in a frame shape. The outer frame portion 44 described above is formed in the remaining portion 65. That is, the doors 60 to 62 are connected via the tear line 50 in the closed state (the state before the break) of the air grid 21, while the doors 60 to 62 remain in the open state (the state after the break). Bending is performed so as to turn toward the front side with the boundary portion with the portion 65 as the center of bending (see the broken line in FIG. 3). Thereby, the front surface of the airbag grid 21 is opened, and the airbag body 37 can be deployed.

  Further, the above-described stitch pattern P is disposed mainly on the outer region of each tear line 50 on the airbag grid 21. Specifically, the stitch pattern P is disposed outside the first tear line 55 and the fourth tear line 56, and the first tear line 55 and the fourth tear line 58 have no intersection in plan view.

On the other hand, the stitch pattern P and the second tear line 56 are orthogonal to each other in plan view at the lower end portion, while the stitch pattern P and the third tear line 57 intersect in plan view at the lower end portion. In this case, the second tear line 56 and the third tear line 57 are bent so as to be substantially parallel to each other after approaching each other at the lower end portion. That is, the lower doors 61 and 62 have a lower end side that has a neck portion 70 in which the second tear line 56 and the third tear line 57 extend in parallel, and the radially outer side of the neck portion 70 is the lower door 61 and 62. It is a bending center.
As described above, the stitch pattern P is arranged so as to surround the upper door 60 outside the upper door 60, while intersecting the second and third tear lines 56 and 57 at the neck portion 70 of the lower doors 61 and 62. .

(Function)
Next, the action at the time of operation of the above-described airbag device 23 will be described.
First, as shown in FIG. 3, when the control unit of the airbag 22 determines that an excessive load of a predetermined value or more is input to the vehicle, the inflator 36 is ignited. When the inflator 36 is ignited, gas is supplied from the inflator 36 into the airbag main body 37 folded in the hub portion 12 at a stretch. Thereby, the airbag main body 37 is inflated.
When the airbag main body 37 is inflated, this pressure acts on the back surface of the airbag grid 21 (cover body 42). And when the pressure more than predetermined value acts on the cover body 42, the airbag grid 21 is fractured | ruptured and the front surface of the airbag grid 21 opens. And the airbag main body 37 is expand | deployed from the opening formed in the airbag grid 21 in a vehicle interior.

  At this time, as shown in FIGS. 3 to 5, the pressure acting on the cover body 42 from the airbag body 37 is basically concentrated at the intersection of the first tear line 55 and the fourth tear line 58. This is the break starting point of the grid 21. The pressure acting on the cover body 42 from the airbag main body 37 branches from the break starting point to, for example, the first tear line 55 and the fourth tear line 58, and the airbag grid 21 moves along the first tear line 55 and the fourth tear line 58. It will be broken. When the breakage of the first tear line 55 and the fourth tear line 58 proceeds, the intersection of the first tear line 55 and the second tear line 56 and the intersection of the fourth tear line 58 and the third tear line 57 are reached, and then the second tear line is reached. Breakage proceeds along 56 and the third tear line 57.

  Thereby, each tear line 50 is broken, and each door 60, 61 defined in each tear line 50 is separated. Then, the separated doors 60 and 61 are rotated about the boundary portion with the remaining portion 65 as a bending center, so that the front surface of the airbag grid 21 is opened and the inflated airbag body 37 is deployed in the vehicle interior. (Refer to the chain line in FIG. 3).

By the way, there is one in which a stitch pattern P is formed on the outer skin 43 on the front surface of the airbag grid 21 in order to improve the design.
In this case, if the stitch pattern P is disposed on the tear line 50, the breaking behavior may be affected when the airbag grid 21 is broken as described above.

Here, in the present embodiment, since the stitch pattern P is disposed so as to surround the outer region of the airbag grid 21, the interference between the stitch pattern P and each door 60 to 62 during the rotation operation of each door 60 to 62. Can be prevented as much as possible.
Specifically, since the stitch pattern P is arranged so as to surround the outer side of the upper door 60 in the upper half portion of the top plate portion 25, the tear line constituting the upper door 60 by the stitch pattern P when the upper door 60 is bent. Breakage of (the first tear line 55 and the second tear line 56) is not inhibited. Thus, the first tear line 55 and the second tear line 56 are smoothly broken, and the upper door 60 is connected to the remaining portion 65 only at a portion between the top plate portion 25 and the upper wall portion 26. The portion is bent quickly with the portion as the center of bending. As a result, the upper door 60 can be smoothly opened due to the expansion of the airbag body 37.

On the other hand, the stitch patterns P intersect the lower doors 61 and 62 between the neck portion 70 (the first ridge line portion 30 and the second ridge line portion 31).
Here, in this embodiment, since the extending direction of the second and third tear lines 56 and 57 intersects the extending direction of the stitch pattern P, the second and third tear lines 56 and 57 and the stitch pattern P At the intersection point, a shearing force acts on the stitch pattern P. In particular, since the second tear line 56 and the stitch pattern P are orthogonal to each other, a greater shearing force acts. Thereby, the stitch pattern P is easily cut. Therefore, the break of the airbag grid 21 is not blocked by the stitch pattern P, and the airbag grid 21 can be quickly broken along the second and third tear lines 56 and 57.
As a result, the lower doors 61 and 62 are quickly bent with the connecting portion as a bending center in a state where the lower doors 61 and 62 are connected to the remaining portion 65 only on the radially outer side (peripheral portion of the side wall portion 28) than the neck portion 70. It will be. As a result, the lower doors 61 and 62 can be smoothly opened due to the expansion of the airbag body 37.

  In addition, on the lower doors 61 and 62 of this embodiment, the extending direction of the stitch pattern P is arranged at the neck portion 70 of the lower doors 61 and 62 in a state substantially orthogonal to the extending direction of the lower doors 61 and 62. The Therefore, even when the stitch pattern P reaches the stitch pattern P and the lower doors 61 and 62 are blocked from being broken by the stitch pattern P, the lower doors 61 and 62 are sufficiently broken. As a result, the lower doors 61 and 62 are bent quickly with the stitch pattern P as the center of bending, so that the lower doors 61 and 62 are hardly affected.

Thus, according to the present embodiment, even when the stitch pattern P is formed on the airbag grid 21, the doors 60 to 62 are connected to the tear lines without affecting the bending operation of the doors 60 to 62. Since it can be smoothly broken along the line 50, the layout of the stitch pattern P can be improved.
As a result, the design performance of the airbag grid 21 can be improved, and the stable deployment performance of the airbag body 37 can be realized.

The technical scope of the present invention is not limited to the above-described embodiment, and includes various modifications made to the above-described embodiment without departing from the spirit of the present invention. That is, the specific structure and shape described in the embodiment are merely examples, and can be changed as appropriate.
For example, the configuration of the steering wheel itself, each tear line, the arrangement position of each stitch pattern, and the like are not limited to those described in the embodiment.
In the above-described embodiment, the case where the present invention is applied to the steering wheel 10 has been described. However, the present invention is not limited to this, and the present invention can also be applied to a passenger airbag, a side airbag, and the like.

DESCRIPTION OF SYMBOLS 21 ... Airbag grid 37 ... Airbag main body 42 ... Cover body 43 ... Skin 36 ... Inflator 60 ... Upper door (main door) 61, 62 ... Lower door (door) P ... Stitch pattern (stitch part)

Claims (1)

An air bag grid formed by covering the skin with a resinous cover body,
An airbag body housed in a folded state inside the airbag grid,
Gas is introduced into the airbag body from an inflator connected to the airbag body, the airbag grid is broken by the inflating airbag body, and the airbag grid is divided and deployed to a plurality of doors. A vehicle airbag apparatus configured,
The airbag grid is formed with a planned fracture line that defines the airbag grid in the plurality of doors,
On the outer skin, a stitch portion is formed in an area outside the main door at least among the plurality of doors ,
The stitch portion is substantially orthogonal to the planned break line that defines a door different from the main door among the plurality of doors, and an intersection portion with the planned break line is broken when the different door is deployed. vehicle airbag device, characterized in that.

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