JP4846422B2 - Airbag device - Google Patents

Description

  The present invention relates to an airbag device for protecting an occupant.

An airbag device that restrains an occupant by deploying an airbag in a vehicle interior with gas supplied from an inflator at the time of a vehicle collision is provided with a vent hole to prevent an excessive increase in the internal pressure of the airbag, Some vent holes are opened during airbag deployment.
In addition, in the airbag device, in order to control the volume expansion and the internal pressure of the airbag, a breaking joint portion that breaks during the deployment is provided in advance in the airbag, and the volume of the airbag is gradually increased by breaking the breaking joint portion. There is something that expands.

For example, Patent Document 1 discloses that an end of a vent hole cover that closes a vent hole is joined to an airbag at a break joint, and the vent hole cover is removed from the vent hole when the break joint is broken when the airbag is deployed. An airbag device is described that disengages and opens the vent hole.
In this case, it is necessary to prevent the vent hole from being opened due to the position of the vent hole cover being shifted during the airbag deployment before the fracture joint is broken. In this regard, Patent Document 1 describes that a vent hole cover is sewn to an airbag in the vicinity of the vent hole.
Japanese Patent Laid-Open No. 2005-199987

However, the conventional vent hole cover positional deviation prevention technology has room for improvement because the number of sewing parts increases and productivity decreases.
Accordingly, the present invention provides an airbag device that can prevent the displacement of the vent hole cover that closes the vent hole and does not reduce the productivity.

The airbag device according to the present invention employs the following means in order to solve the above problems.
The invention according to claim 1 is provided in a circular airbag (for example, an airbag 32 in an embodiment described later), an inflator opening (for example, an opening 37a in an embodiment described later), and a side of the inflator opening. An airbag apparatus comprising a vent hole (for example, a vent hole 37b in an embodiment described later) and a vent hole cover (for example, a vent hole cover 50 in an embodiment described later) for closing the vent hole, the airbag Has a break joint portion (for example, a sewing portion 39 in an embodiment described later) that breaks when the airbag is deployed in the vicinity of the outer periphery thereof, and the vent hole cover has a central portion (for example, described later) that closes the vent hole. 3 or more end portions (for example, the end portion 51 in the embodiments described later) from the central portion 52 in the embodiment to be performed. The form that extends outwardly toward the ~51g), wherein an air bag device characterized by each end portion is joined to said airbag by the rupture joint.
With this configuration, the vent hole cover can be prevented from being displaced during manufacture and deployment of the airbag, and the vent hole is kept closed until the end of the vent hole cover is removed from the airbag. be able to.

The invention according to claim 2 is the invention according to claim 1, wherein the vent hole cover includes four of the end portions, and each of the end portions (for example, the end portions 51 a to 51 d in the embodiments described later) provided from the diagonal line connecting the oppositely disposed ends to the center is out position of the vent hole, characterized in Tei Rukoto.
By configuring in this way, the vent hole can be opened when any one of the end portions joined to the airbag is removed from the vent hole cover.

The invention according to claim 3 is the invention according to claim 1 or 2, wherein the opening of the inflator is at the center of a base fabric (for example, a second base fabric 37 in an embodiment described later) constituting the airbag. are arranged, at least two of the ends of said end portion fixed to the vent hole cover (e.g., an end portion 51a in the embodiment described later, 51b or end 51e, 51f) is Ru passing over said inflator opening immediately line, characterized in that located separately on both sides of the inflator opening.
By comprising in this way, the shift | offset | difference of the vent hole cover to the direction orthogonal to the straight line which passes on an inflator opening can be suppressed to the minimum.

The invention according to claim 4 is the invention according to any one of claims 1 to 3, wherein the vent hole cover is formed such that the central part is wider than the vent hole and the central part is formed. The width is formed narrower as it goes from each end to each end .
By comprising in this way, the resistance at the time of a vent hole cover coming out from a vent hole can be reduced.

According to the first aspect of the invention, the position of the vent hole cover does not shift during the manufacture and deployment of the airbag, and the closure of the vent hole can be maintained until the end of the vent hole cover is removed from the airbag. The air bag can be appropriately controlled for internal pressure and deployment.

According to the second aspect of the present invention, if any one of the end portions joined to the airbag in the vent hole cover is removed, the vent hole can be opened. Thus, the internal pressure of the airbag can be controlled appropriately.

  According to the invention which concerns on Claim 3, the shift | offset | difference of the vent hole cover to the direction orthogonal to the straight line which passes on an inflator opening can be suppressed to the minimum.

  According to the invention which concerns on Claim 4, the resistance at the time of a vent hole cover pulling out from a vent hole can be reduced.

  Embodiments of an airbag device according to the present invention will be described below with reference to the drawings of FIGS. In addition, the airbag apparatus of each Example described below is the aspect of the airbag apparatus accommodated in the handle | steering_wheel for the driver | operator of a vehicle, In the following description, "front and back" is the same as the front and rear in a vehicle body. .

As shown in FIG. 1, an airbag module 13 of an airbag device is accommodated in a steering wheel 12 disposed in front of a seat 11 of a driver seat.
As shown in FIG. 2, the steering wheel 12 has a boss portion 16 fixed to the rear end of the steering shaft 14 by a nut 15, and a cup-shaped front cover 17 is fixed to the boss portion 16. A rear cover 19 is fixed to the periphery of the front cover 17 by a plurality of bolts 18 so as to close the front cover 17. A plurality of spoke portions 20 extending radially are attached to the outer peripheral surface of the front cover 17, and a steering wheel main body 21 is supported by the spoke portions 20.

A retainer 22 is fastened together with bolts 18 on the inner peripheral surface of the rear cover 19, and the airbag module 13 is supported on the retainer 22. A tear line 19a is formed on the inner surface of the rear cover 19 to promote breakage.
The airbag module 13 includes an inflator 31 filled with a propellant that generates high-pressure gas by combustion, an airbag 32 that is configured by sewing a base cloth and inflates when high-pressure gas generated by the inflator 31 is introduced, A fixing ring 33 for fixing the base of the bag 32 is provided. The flange 31 a of the inflator 31 and the fixing ring 33 are superposed on the front surface and the rear surface of the retainer 22, and are fastened and fixed with a plurality of bolts 34 and nuts 35. The base portion of the airbag 32 is fixed between the rear surface of the retainer 22 and the front surface of the fixing ring 33.

As shown in FIG. 3, the circular airbag 32 includes a first base fabric 36 on the rear side (side facing the occupant) and a second base fabric 37 that is superposed on the front surface thereof. And the 2nd base fabric 37 is sewn integrally by the sewing part 38 on the outer peripheral part. Further, the overlapped first base cloth 36 and second base cloth 37 are sewn by a plurality of spiral sewing parts (break joints) 39 inside the sewing part 38. In this embodiment, there are three spiral sewing portions 39, but there may be two or four or more. The outer sewing portion 38 is firmly sewn with a thick thread so as not to be broken when the airbag 32 is inflated. The three spirally-shaped sewing portions 39 inside the airbag 32 can be broken when the airbag 32 is inflated. It is fragilely sewn with fine thread.
The radially inner end 39a of the spiral sewing part 39 is directed to the center of the airbag 32, and stress is concentrated on the radially inner end 39a when the airbag 32 is deployed to promote the breakage of the sewing part 39. ing.

The second base fabric 37 has a circular opening (inflator opening) 37 a surrounding the inflator 31, through holes 37 c of a plurality of bolts 34 formed around the opening 37 a, and internal gas when the airbag 32 is inflated. A circular vent hole 37b that allows a part of it to escape is formed. The opening 37 a is disposed at the center of the second base cloth 37, and the vent hole 37 b is disposed at the side of the opening 37 a and is eccentric from the center of the second base cloth 37.
As described above, since the second base fabric 37 is sandwiched between the rear surface of the retainer 22 and the front surface of the fixing ring 33 and is tightened by a plurality of bolts 34, the gas generated by the inflator 31 is the second base fabric. The air is supplied to the inside of the airbag 32 from the central opening 37 a of the cloth 37.

The airbag 32 is provided with a vent hole cover 50 that controls its internal pressure. As shown in FIG. 4, the vent hole cover 50 is substantially X-shaped in plan view and includes four end portions 51a, 51b, 51c, and 51d. The central part 52 of the vent hole cover 50 is formed wider than the vent hole 37b so as to be able to close the vent hole 37b, and the width increases as the end part 51a, 51b, 51c, 51d approaches from the central part 52. Is narrower. The vent hole cover 50 is disposed on the inner surface of the second base fabric 37 at a position where the central portion 52 can close the vent hole 37b, and the four end portions 51a, 51b, 51c, 51d are provided on the first base fabric. 36 and the second base cloth 37 are cut in an arc shape in front of the sewing portion 38 along the peripheral edge of the second base cloth 37, and are simultaneously sewn by three spiral sewing portions 39 that join the first base cloth 36 and the second base cloth 37 together. Has been.

The relative positional relationship between the vent hole 37b and the vent hole cover 50 will be described in detail. The center of the vent hole 37b is on the diagonal line connecting the end portions (51a and 51c and 51b and 51d) opposed to each other in the vent hole cover 50. It is not located, but is slightly shifted from the intersection of these diagonal lines. That is, each end 51a, 51b, 51c, 51d of the vent hole cover 50 is provided at a position where at least a part of the vent hole 37b is removed from a strip-shaped diagonal region connecting the ends.
Further, the end portions 51a and 51b of the vent hole cover 50 are located on a straight line passing through the center of the inflator opening 37a (that is, on the diameter of the second base fabric 37 in this embodiment) and separated on both sides of the inflator opening 37a. is doing. In other words, the center of the inflator opening 37a is on a straight line connecting two adjacent end portions 51a and 51b in the vent hole cover 50, and is arranged at a position equidistant from the end portions 51a and 51b.

  The airbag 32 is joined to the inside of the sewing portion 38 with a spiral sewing portion 39 after the outer peripheral portions of the first base fabric 36 and the second base fabric 37 are joined with the sewing portion 38 and then turned over. The vent hole cover 50 may be temporarily fixed to the second base cloth 37 at an appropriate position where the vent hole 37b is blocked before turning over so that the vent hole cover 50 is not displaced when turning over.

  In the airbag device configured as described above, the inflator 31 is ignited when a gravitational acceleration of a predetermined value or more is detected at the time of a vehicle collision, and the folded airbag 32 starts to be inflated with the gas generated by the inflator 31. When the airbag 32 is inflated, the rear cover 19 is broken at the tear line 19a by receiving this pressure, and the airbag 32 is deployed into the vehicle compartment from the opening formed there.

  As shown in FIG. 6, when the airbag 32 is inflated, three spiral sewing portions 39 integrally join the first base fabric 36 and the second base fabric 37, so that the airbag 32 is inflated at a stretch. After the formation of a small-capacity airbag at an early stage, the three sewing portions 39 are broken from the radially inner side to the outer side as the internal pressure of the airbag 32 increases, so that the airbag 32 Can gradually increase the volume while maintaining an appropriate internal pressure, and finally develop a flat shape in the front-rear direction to exert the maximum restraining force.

  The vent hole cover 50 is restrained by the sewing portions 39 of the first base fabric 36 and the second base fabric 37 at the end portions 51a, 51b, 51c, 51d until all the three sewing portions 39 are broken. The vent hole 37b is blocked by the vent hole cover 50 to prevent gas leakage, and the internal pressure of the airbag 32 can be quickly raised and the internal pressure can be appropriately maintained.

  When the three sewing parts 39 are all broken at the end of deployment of the airbag 32, the restriction of the end parts 51a, 51b, 51c, 51d of the vent hole cover 50 is released as shown in FIG. A part of the cover 50 is pushed out of the vent hole 37b to open the vent hole 37b. As a result, excess gas in the airbag 32 is discharged from the vent hole 37b, and an excessive increase in the internal pressure of the airbag 32 can be prevented. At this time, since the vent hole 37b is provided in the second base cloth 37, the gas discharged from the vent hole 37b does not directly hit the driver, and the driver does not feel uncomfortable.

Further, in this airbag device, the four end portions 51a, 51b, 51c, 51d of the vent hole cover 50 are joined to the airbag 32 by the sewing portion 39. Therefore, when the airbag 32 is manufactured, the vent hole cover 50 is The center portion 52 can be prevented from being displaced, and when the airbag 32 is inflated and rounded during the deployment of the airbag 32, the center portion 52 of the vent hole cover 50 is attached to the airbag 32. It is possible to prevent the position from being displaced outward in the radial direction.
In particular, in this embodiment, the end portions 51a and 51b of the vent hole cover 50 are located on both sides of the inflator opening 37a on a straight line passing through the center of the inflator opening 37a. It is possible to minimize the displacement of the vent hole cover 50 in the orthogonal direction. As long as the object of minimizing the displacement of the vent hole cover 50 in the direction orthogonal to the straight line passing through the inflator opening 37a can be achieved, the end portions 51a and 51b are straight lines passing through the center of the inflator opening 37a. It may be slightly shifted from the top. That is, the end portions 51a and 51b are arranged on a substantially straight line passing through the center of the inflator opening 37a.

Further, since the vent hole cover 50 becomes narrower as it approaches the end portions 51a, 51b, 51c, 51d from the central portion 52, the resistance when the vent hole cover 50 comes out of the vent hole 37b is reduced. be able to.
Further, as described above, each end 51a, 51b, 51c, 51d of the vent hole cover 50 has at least the vent hole 37b from the band-shaped diagonal region connecting the ends (51a and 51c and 51b and 51d). Since a part of the vent hole cover 50 is provided at a position where it is removed, the vent hole 37b can be opened when any one of the four end portions 51a, 51b, 51c, 51d of the vent hole cover 50 is removed from the airbag 32. it can. Therefore, the vent hole 37b can be reliably opened at an appropriate timing.

  As a result, the closure of the vent hole 37b can be maintained until the sewing portion 39 is broken and at least one of the end portions 51a, 51b, 51c, 51d of the vent hole cover 50 is detached from the airbag 32. The vent hole 37b can be opened when at least one of the end portions 51a, 51b, 51c, 51d is removed from the airbag 32, so that the internal pressure of the airbag can be appropriately controlled. Proper deployment control can be performed.

FIG. 8 shows an embodiment in which the vent hole cover 50 is formed in an inverted Y shape. Since the configuration other than the vent hole cover 50 is the same as that of the above-described embodiment, the description thereof will be omitted, and only the vent hole cover 50 will be described below.
The vent hole cover 50 has three end portions 51e, 51f, and 51g, and the central portion 52 of the vent hole cover 50 is formed wider than the vent hole 37b so as to close the vent hole 37b. The vent hole cover 50 becomes narrower as it approaches the end portions 51e, 51f, 51g from the central portion 52, and these end portions 51e, 51f, 51g are connected to the first base fabric 36 and the second base fabric 37. Are sewn at the same time by three spiral-shaped sewing portions 39 joining the two. Since the width becomes narrower as it approaches each end 51e, 51f, 51g from the central portion 52, it is possible to reduce the resistance when the vent hole cover 50 comes out of the vent hole 37b.

The relative positional relationship between the vent hole 37b and the vent hole cover 50 will be described in detail. The center of the vent hole 37b is not located in a belt-like straight line region connecting adjacent end portions (51e and 51f, 51f and 51g, 51g and 51e) in the vent hole cover 50. This is to allow the vent hole 37b to be opened when any one of the three end portions 51e, 51f, 51g of the vent hole cover 50 is detached from the airbag 32.
Further, in order to minimize the displacement of the vent hole cover 50 in the direction orthogonal to the straight line passing through the inflator opening 37a, the end portions 51e and 51f of the vent hole cover 50 are on a straight line passing through the center of the inflator opening 37a. (That is, on the diameter of the second base fabric 37 in this embodiment), it is located separately on both sides of the inflator opening 37a. In other words, the center of the inflator opening 37a is on a straight line connecting two adjacent end portions 51e and 51f in the vent hole cover 50, and is disposed at an equal distance from the end portions 51e and 51f. Note that the end 51g is disposed on a straight line connecting the opening 37a and the vent hole 37b.

  Also in the airbag apparatus of FIG. 8, since the three end portions 51 e, 51 f, 51 g of the vent hole cover 50 are joined to the airbag 32 by the sewing portion 39, the vent hole cover 50 is not manufactured when the airbag 32 is manufactured. The center portion 52 can be prevented from being displaced, and when the airbag 32 is inflated and rounded during the deployment of the airbag 32, the center portion 52 of the vent hole cover 50 is attached to the airbag 32. It is possible to prevent the position from being displaced outward in the radial direction. As a result, the closure of the vent hole 37b can be maintained until the sewing portion 39 is broken and at least one of the end portions 51e, 51f, 51g of the vent hole cover 50 is detached from the airbag 32. Thereby, the internal pressure of an airbag can be controlled appropriately and the deployment of the airbag 32 can be controlled appropriately.

  In the above-described embodiment, as shown in FIG. 5, the end portions 51 a to 51 g of the vent hole cover 50 are sewn over the portion reaching the outermost sewing portion 39, but the outermost sewing portion 39 is used. Further, the sewing of the vent hole cover 50 can be stopped at the inner sewing portion 39, for example, the second sewing portion 39 from the inner side. By configuring in this way, it is possible to set so that the vent hole 37b is already opened when the outermost sewing portion 39 is broken. Thereby, the timing at which the vent hole 37b is opened and the internal pressure of the airbag 32 can be adjusted.

In the above-described embodiment, the sewing portion 39 is formed in a spiral shape, but may be formed in a concentric shape, or the sewing portion 39 may be partially provided on the outer peripheral portion of the airbag 32 without being provided on the entire circumference. Good.
The shape of the vent hole cover 50 is not limited to the above-described embodiment, and the number of end portions joined to the airbag 32 may be any number as long as it is three or more.
In the above-described embodiment, the breaking joint portion of the airbag 32 is constituted by the sewing portion 39, but the breaking joining portion is not limited to sewing, and may be constituted by weaving or joining.
Further, in the above-described embodiments, the aspect of the airbag device stored in the handle has been described. However, the present invention can also be applied to an airbag device other than the retractable type in the handle.

It is a perspective view which shows the vehicle interior of the vehicle provided with the airbag apparatus which concerns on this invention. It is sectional drawing which follows the AA line of FIG. It is a disassembled perspective view of the airbag in Example 1 of the airbag apparatus which concerns on this invention. It is a rear view of the airbag in the said Example 1. FIG. It is sectional drawing which follows the BB line of FIG. It is sectional drawing of the airbag deployment initial stage of the said Example 1. FIG. FIG. 4 is a cross-sectional view of the airbag deployment late stage of the first embodiment. It is a rear view of the airbag in Example 2 of the airbag apparatus which concerns on this invention.

Explanation of symbols

32 airbags
37 Second base fabric (base fabric)
37a Opening (Inflator opening)
37b Vent hole 39 Sewing part Breaking joint)
50 End of vent hole cover 51a-51g
52 center

Claims (4)

An airbag device comprising a circular airbag, an inflator opening, a vent hole provided on a side of the inflator opening, and a vent hole cover for closing the vent hole,
The airbag has a fracture joint that breaks when the airbag is deployed in the vicinity of the outer periphery thereof,
The vent hole cover is configured to extend outward from a central portion closing the vent hole toward three or more end portions, and each end portion is joined to the airbag at the break joint portion. An airbag device characterized by comprising: The vent hole cover has four end portions,
Wherein each end, an air bag device according to the diagonal connecting the oppositely disposed ends in claim 1, characterized in Tei Rukoto provided at the center is out position of the vent hole. The inflator opening is arranged at the center of the base fabric constituting the airbag,
At least two of the ends of said end portion fixed to the vent hole cover, the upper the inflator opening in a straight line Ru passing, claim, characterized in that located separately on both sides of the inflator opening 1 or The airbag apparatus according to claim 2. 2. The vent hole cover according to claim 1 , wherein the central portion is formed wider than the vent hole, and the width is narrowed from the central portion toward the end portions. Item 4. The airbag device according to any one of items 3.

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