JP4922796B2 - Airbag device - Google Patents

Description

  The present invention relates to an airbag device capable of adjusting an inflation pressure in an airbag according to an inflation and deployment process of the airbag.

  2. Description of the Related Art Conventionally, a vehicle such as an automobile is provided with an airbag device that inflates and deploys a bag-like airbag to protect an occupant when the vehicle collides.

  In addition to protecting the driver and passengers in the passenger seat, the airbag device includes various devices such as a passenger in the rear seat, a device that protects the passenger from impact when the vehicle collides sideways, or rolls over. Has been put to practical use, and the shape of the airbag differs depending on the place where it is installed, but most of them are inflated and deployed by the high pressure gas generated from the inflator when the vehicle collides, A structure that protects an occupant from an impact by absorbing and mitigating the impact at the time of collision by an airbag is employed.

  On the other hand, the conventional airbag device has a structure in which an airbag is instantly inflated by high-pressure gas ejected from an inflator and then deployed in a predetermined direction.

  For this reason, for example, when the child seat is attached to the seat rearward, the airbag may abut against the upper part of the backrest of the child seat at the initial stage of inflation and deployment, and as a result, a large impact during inflation may act on the child seat. .

  In order to prevent this, conventionally, when an object such as a child seat is close to the airbag in the early stage of inflation and deployment of the airbag, this is detected in advance and the inflation pressure of the airbag is adjusted to act on the object. To relieve the impact, or to install a plurality of inflators, in the initial stage of inflation and deployment, high pressure gas is ejected from one inflator, and then high pressure gas is ejected from the plurality of inflators so that the airbag is deployed in a predetermined shape. A vehicle airbag has been proposed.

  However, the air bag device that adjusts the former inflation pressure requires a detecting means that adjusts the opening area of the vent hole provided in the air bag with an electromagnetic opening and closing means or detects an object. There is a problem that becomes complicated and expensive.

  Moreover, in the airbag apparatus provided with a plurality of the latter inflators, it is difficult to adjust the ignition timing of the inflator, and there is a problem of a party that requires a great deal of cost to control it to be in a suitable condition.

  In order to improve such a conventional problem, for example, Patent Document 1 proposes an airbag device in which the opening area of a vent hole is made variable without using an electromagnetic opening / closing means.

In the vehicle occupant protection device described in Patent Document 1, the airbag vent hole is separated from the fixed member at the initial stage of inflation and deployment of the airbag, and the vent hole is brought into contact with the fixed member at the later stage of inflation and deployment By changing the area, the pressure in the initial stage of inflation and deployment of the airbag is reduced, and the protection capability is improved in the later stage of inflation and deployment.
Japanese Patent Laid-Open No. 2001-114065

  However, as in the airbag device described in Patent Document 1, when the opening area of the vent hole is increased at the initial stage of inflation and deployment of the airbag and then the opening area is decreased, The gas pressure required to break the sheet skin covering the airbag is lost.

  As a result, the high-pressure gas ejected from the inflator cannot be used efficiently, and a large-power inflator that takes into account the loss is necessary to instantly inflate and deploy the airbag to the specified shape, which increases costs. It becomes.

  Further, in the airbag of Patent Document 1, since the opening area of the vent hole is reduced in the latter stage of inflation and deployment of the airbag, the airbag is normally deployed regardless of the presence or absence of an object in the inflation and deployment direction of the airbag. If there is an object such as a child seat in the direction of deployment of the bag, there is a problem that a large impact acts on this object.

  The present invention has been made to remedy such problems, and provides an airbag device that reduces the impact on an object existing in the direction of inflation and deployment of the airbag without requiring complicated and expensive detection means and control means. It is for the purpose.

The air bag device of the present invention, an air bag device constituting and an inflator for supplying inflation gas to the air bag in the air bag, pair toward the occupant in its deployed state airbag passenger and has a restraining surface, in the air bag, and a tether belt having both ends Ru is connected to the high pressure gas inlet of the peripheral portion and the occupant restraint surface from an inflator, and a vent hole provided in the airbag, and is connected to the tether belt A vent hole opening / closing means for opening / closing the vent hole , wherein the vent hole opening / closing means guides the slider to be slid along the vent hole as the tether belt extends, and a slider connected to an intermediate portion of the tether belt. Venting at the intermediate extension position of the tether belt in the middle of the inflation and deployment process of the airbag It is composed of a valve hole which is opened to the slider so as to overlap with Lumpur, the slider of the vent hole opening and closing means to close the vent hole at the time of and during all deployment non deployment of the air bag, and an intermediate tether belt those configured to open the vent hole by overlapping the valve hole in wrought position.

  With the above configuration, since the vent hole is closed by the vent hole opening / closing means in the initial stage of inflation and deployment of the airbag, the high-pressure gas ejected from the inflator can efficiently inflate and deploy the airbag in a predetermined direction efficiently. Can do.

  Also, there is an object such as a child seat attached to the back of the seat in the vicinity of the airbag deployment direction, and when the airbag in the middle of inflation is in contact with this object, the vent hole opening / closing means causes the tether belt to move to the intermediate extension position. Since the vent hole is opened, high-pressure gas is discharged from the vent hole and the increase in the inflation pressure inside the airbag is suppressed, reducing the impact on the object due to the inflation pressure of the airbag. can do.

  Further, in the latter stage of inflation and deployment of the airbag, the vent hole is closed by the vent hole opening and closing means, and the passenger can be restrained by the airbag that is inflated and deployed to the final shape by the high-pressure gas. Since the vent hole opening / closing means is operated by the tether belt, the electromagnetic opening / closing means for adjusting the opening area of the vent hole, the detection means for detecting the occupant, and the ignition timing are different. Since a plurality of inflators are not required, an air bag having a simple structure and high safety can be obtained at low cost.

Further, with the above configuration, the vent hole opening / closing means can be reliably operated by the tether belt together with the inflation and deployment of the airbag, and the exhaust timing can be easily set by the position of the valve hole provided in the slider. Design and manufacture are easy.

  According to the airbag device of the present invention, since the vent hole is closed by the vent hole opening / closing means at the initial stage of inflation and deployment of the airbag, the high-pressure gas ejected from the inflator efficiently moves the airbag in a predetermined direction. It can be surely inflated and deployed.

  Also, there is an object such as a child seat attached to the back of the seat in the vicinity of the airbag deployment direction, and when the airbag in the middle of inflation is in contact with this object, the vent hole opening / closing means causes the tether belt to move to the intermediate extension position. Since the vent hole is opened, high-pressure gas is discharged from the vent hole and the increase in the inflation pressure inside the airbag is suppressed, reducing the impact on the object due to the inflation pressure of the airbag. can do.

  Further, in the latter stage of inflation and deployment of the airbag, the vent hole is closed by the vent hole opening and closing means, and the passenger can be restrained by the airbag that is inflated and deployed to the final shape by the high-pressure gas. Since the vent hole opening / closing means is operated by the tether belt, the electromagnetic opening / closing means for adjusting the opening area of the vent hole, the detection means for detecting the occupant, and the ignition timing are different. Since a plurality of inflators are not required, an air bag having a simple structure and high safety can be obtained at low cost.

  An embodiment in which the present invention is implemented in a driver airbag device will be described in detail with reference to the drawings.

  FIG. 1 is an exploded perspective view of an airbag device mounted almost at the center of the steering wheel, FIG. 2 is a cross-sectional view depicting the assembled state of the airbag device, and FIG. 3 is an enlarged perspective view of vent hole opening / closing means. 4 to 6 are explanatory diagrams of the operation.

  An airbag device for a driver that protects a driver from an impact when a vehicle collides includes a base plate 1 installed at a substantially central portion of a steering wheel (not shown), an inflator 2 attached to the base plate 1, and an inflator. 2 includes an airbag 3 inflated and deployed by high-pressure gas ejected from 2, a cover 4 covering the upper surface of the airbag 3 housed in the base plate 1 in a folded state.

  The base plate 1 is formed in a flat, substantially pentagonal box shape whose upper surface is opened by bending a metal plate, and a circular inflator mounting hole 1b is opened at substantially the center of the bottom plate 1a. The gas ejection part 2a of the inflator 2 is fitted to 1b from below.

  On the upper edge of the side plate 1c formed by bending the periphery of the base plate 1 upward, brackets 1d are projected, for example, at three locations, and the cover 4 is attached to these brackets 1d. The airbag 3 in a folded state is placed on the bottom plate 1a surrounded by the side plate 1c.

  The airbag 3 is formed by sewing a plurality of base fabrics 3a made of a woven fabric such as nylon into a bag shape, and is inflated and deployed in an approximately elliptical shape at the time of a vehicle collision, thereby The driver's head and chest are constrained by the opposing occupant restraint surface 3b, and the driver is protected from the impact at the time of a collision. A gas inlet 3c that is substantially the same size as the bag attachment hole 1b is opened.

  A reinforcing cloth 3d is sewn around the gas introduction port 3c to reinforce the periphery of the gas introduction port 3c, and the retainer 5 is inserted into a plurality of mounting holes 3e formed in the periphery of the gas introduction port 3c. The tip of the more sticking fixture 5a is inserted from above.

  The retainer 5 is formed of a substantially square metal plate, and a circular hole 5b that is substantially the same size as the gas introduction port 3c is opened at the center. The tip of the fixing tool 5a protruding from the retainer 5 is the base plate 1. By tightening a nut 5c protruding through the flange 2b through the mounting hole 1e drilled in the bottom plate 1a and the mounting hole 2c drilled in the flange 2b of the inflator 2, and screwed to the tip portion The inflator 2 is fixed to the base plate 1, and at the same time, the periphery of the gas inlet 3 c is airtightly sandwiched between the base plate 1 and the retainer 5.

  As shown in FIGS. 1 to 3, a tether belt 3 f that defines the inflated shape of the airbag 3 is provided in the airbag 3.

  The tether belt 3f is formed in a band shape from a woven fabric such as nylon, and one end side is sewn to the inner surface of an occupant restraint surface 3b that is the upper side of the airbag 3 when inflated.

  The other end side of the tether belt 3f is branched into two paths, and the distal end portion of the branch portion 3g is sewn to the peripheral portion of the gas introduction port 3c so as to straddle the gas ejection portion 2a of the inflator 2. When the airbag 3 is folded, it is stored in the airbag 3 in a substantially U-shaped state as shown in FIG.

  Also, vent hole opening / closing means 7 is connected to the tether belt 3f slightly above the branch portion.

  The vent hole opening / closing means 7 opens and closes the vent hole 8 opened to the periphery of the gas inlet 3c of the airbag 3 and the bottom plate 1a of the base plate 1, and includes a slider 7a made of a strip-like material having substantially the same width as the tether belt 3f, The slider 7a includes a guide member 7b for slidably sandwiching the slider 7a with the base cloth 3a of the airbag 3, and a valve hole 7c opened in the slider 7a.

The slider 7a and the guide member 7b are formed of a woven fabric such as nylon similar to the tether belt 3f, and one end of the slider 7a is sewn in the vicinity of a branch portion that is an intermediate portion of the tether belt 3f. While being folded along the inner surface of the airbag 3, the guide member 7b is formed in a substantially frame shape, and both side edges are sewn to the inner surface of the lower base fabric 3a at a slightly wider interval than the width of the slider 7a. Has been.

  The valve hole 7c opened in the slider 7a is formed by, for example, a square hole whose one side is larger than the diameter of the vent hole 8, and is overlapped with the vent hole 8 in the middle of the process of inflating and deploying the airbag 3. Is open.

  Thus, when the airbag 3 is folded and stored in the base plate 1, the airbag 3 is not deployed, so the vent hole 8 is closed by the slider 7 a and the airbag 3 is inflated and deployed. In the middle of the process, since the tether-balt 3f is in the intermediate extended position, the valve hole 7c of the slider 7a overlaps with the vent hole 8, and when the airbag 3 is further deployed thereafter, the vent hole 8 is again moved to the slider 7a. Is closed, and the airbag 3 is reached when fully deployed.

  On the other hand, the cover 4 covering the upper surface of the airbag 3 housed in the base plate 1 in the folded state is entirely formed of resin, and a tear line 4a made of a V-groove is formed in, for example, an H shape in the approximate center of the back surface. Is formed.

  The tear line 4a is cleaved by the inflation pressure when the airbag 3 is inflated so as not to prevent the airbag 3 from being inflated and deployed. The tear line 4a covers the cover 4 via a mounting portion 4b protruding from the back surface of the cover 4. Is attached to the bracket of the base plate 1.

  Next, the operation of the thus configured airbag will be described with reference to FIGS.

  The air bag 3 is modularized by attaching it to the base plate 1 in a folded state as shown in FIG. 2 in advance, and is mounted at a predetermined position of the steering wheel in this state of the module. When the valve hole 7c of the vent hole opening / closing means 7 is in the position shown in FIG. 3, the vent hole 8 is closed by the slider 7a.

  On the other hand, when the vehicle collides and the impact is sensed by a collision sensing means (not shown), high-pressure gas is ejected into the airbag 3 from the ejection hole 2d formed in the gas ejection portion 2a of the inflator 2 attached to the base plate 1. Is done.

  As a result, the airbag 3 starts to expand, and the tear line 4a of the cover 4 is cleaved by the expansion pressure at this time, and the cover 4 is opened.

  Thereafter, the airbag 3 is inflated and deployed in a predetermined direction, that is, in the direction of the driver. At the initial stage of inflation and deployment of the airbag 3, the vent hole 8 is closed by the slider 7a of the vent hole opening / closing means 7, The airbag 3 continues to be inflated and deployed in a stable state in a predetermined direction by the high-pressure gas ejected from the inflator 2 from the initial stage of inflation and deployment.

  When the airbag 3 reaches approximately the middle of the inflating and deploying process, the tether belt 3f is pulled with the deployment of the upper surface of the airbag 3, that is, the occupant restraint surface 3b, and the slider 7a is also pulled upward. As shown in FIG. 4, the slider 7a slidably sandwiched between the base cloth 3a and the guide member 7b slides and the valve hole 7c opened in the slider 7a is in the intermediate extended position. It overlaps with the vent hole 8.

  Thus, as shown in FIG. 5, when the vehicle collides and the airbag 3 is inflated and deployed when the driver is in a position close to the steering wheel, the occupant restraint surface 3b of the airbag 3 becomes an object X such as a child seat. Even if it abuts, a part of the high-pressure gas in the airbag 3 is discharged from the vent hole 8 as shown in FIG. 6, so that the impact acting on the object X due to the inflation pressure of the airbag 3 can be reduced. .

  Thereafter, when the airbag 3 continues to be further deployed, the vent hole 8 is closed again by the slider 7a as shown in FIGS. 7 and 8, so that the high pressure ejected from the inflator 2 in the latter stage of inflation and deployment of the airbag 3 The gas is reached at the time when the airbag 3 is fully deployed, which is the final shape.

  As a result, the driver's chest and head are restrained as shown in FIG. 9 by the airbag 3 inflated and deployed to the final shape by the high-pressure gas, so that the occupant can be reliably protected from the impact at the time of collision. become.

  As described above, when there is no object X such as a child seat in the deployment direction of the airbag 3 and the vehicle collides with the driver riding in a normal posture, the airbag 3 is inflated and deployed. Since the vent hole opening / closing means 7 is operated by the expanding tether belt 3f and the vent hole 8 is instantaneously closed, the high-pressure gas ejected from the inflator 2 into the airbag 3 is discharged from the vent hole 8 to the outside. The air bag 3 can be instantly inflated and deployed in a predetermined direction and in a predetermined shape, so that the high pressure gas ejected from the inflator 2 can be efficiently used during the entire deployment. The occupant can be reliably protected from the impact at the time of collision.

  In addition, although the example applied to the driver's airbag has been described in the above embodiment, the present invention can be applied to all airbag devices provided with a tether belt 3f in the airbag 3.

  The airbag of the present invention can efficiently use the high-pressure gas ejected from the inflator by opening and closing the vent hole by the action of the vent hole opening and closing means according to the inflation and deployment process of the airbag, and the pressure in the airbag. Therefore, it is optimal for an airbag device that protects an occupant from an impact when a vehicle collides.

It is a disassembled perspective view of the airbag apparatus which becomes embodiment of this invention. It is sectional drawing of the assembly state of the airbag apparatus which becomes embodiment of this invention. It is a perspective view of the vent hole opening / closing means provided in the airbag according to the embodiment of the present invention. It is action | operation explanatory drawing of the vent hole opening-closing means in the middle of the expansion | deployment process of the airbag which becomes embodiment of this invention. It is action explanatory drawing which shows the middle of the expansion | deployment process of the airbag which becomes embodiment of this invention. It is action | operation explanatory drawing of the vent hole opening-closing means in the middle of the expansion | deployment process of the airbag which becomes embodiment of this invention. It is action | operation explanatory drawing of the vent hole opening / closing means in the final state of the expansion | deployment process of the airbag which becomes embodiment of this invention. It is action | operation explanatory drawing of the vent hole opening / closing means in the final state of the expansion | deployment process of the airbag which becomes embodiment of this invention. It is action explanatory drawing which shows the final state of the expansion | deployment process of the airbag which becomes embodiment of this invention.

Explanation of symbols

2 Inflator 3 Airbag 3b Occupant restraint surface 3f Tether belt 7 Vent hole opening / closing means 7a Slider 7b Guide member 7c Valve hole 8 Vent hole

Claims (1)

An airbag apparatus constituting and an inflator for supplying inflation gas to the air bag in the air bag,
Together with an occupant restraint surface you pair toward the occupant in the airbag that deployed state, the in the airbag, Ru both ends are connected to the peripheral portion of the high pressure gas inlet from the inflator and the occupant restraint surface A tether belt; a vent hole provided in the airbag; and a vent hole opening / closing means connected to the tether belt for opening and closing the vent hole ,
The vent hole opening / closing means includes a slider connected to an intermediate portion of the tether belt, a guide member for guiding the slider to slide along the vent hole as the tether belt expands, and inflation of the airbag It is composed of a valve hole opened in the slider so as to overlap the vent hole at an intermediate extension position of the tether belt in the middle of the deployment process,
The slider of the vent hole opening / closing means closes the vent hole when the airbag is not deployed and fully deployed, and overlaps the valve hole at the intermediate extension position of the tether belt. An airbag device configured to be opened.

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