JP2009255842A - Airbag device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an airbag device so structured as to be surely operated by surely cleaving a cover section in the beginning of the inflation and development of the air bag of an air bag device and making compatible the inflation and development of the airbag and an occupant arresting capability. <P>SOLUTION: This airbag device 100 comprises an inflator 230, the airbag 140 inflated and developed by the gas from the inflator, a preliminary inflation chamber 300 disposed between the inflator and the airbag 140, smaller in capacity than the airbag 140, and having a folded section 310 which first receives the supply of the gas from the inflator and extends by the supply of the gas, and the cover section 150 for covering the airbag 140 from the outside. The preliminary inflation chamber 300 cleaves the cover section 150 by the extension and projection of the folded section 310. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an airbag apparatus including an airbag that inflates and deploys to protect an occupant when an impact occurs on a vehicle due to a collision accident or the like.

  An air bag that protects an occupant in the event of a vehicle collision is attached to the center of the steering wheel in the case of the driver's seat, and to the upper portion of the instrument panel in the case of the passenger's seat.

  When an airbag device mounted on a vehicle steering or an instrument panel is activated, the airbag is rapidly inflated and deployed by the high-pressure gas ejected from the inflator. The cover part covering the upper part of the airbag is cleaved, and the airbag is inflated and deployed in the passenger compartment to prevent the passenger from colliding with the steering wheel, the instrument panel, and further the windshield. However, in order to inflate and deploy the airbag, the cover portion covering the upper portion of the airbag must be cleaved.

  In order to cleave the cover part, for example, Patent Document 1 discloses an airbag device in which a plate is provided at the opening of the inflator and the plate is pressed by the gas generated from the inside of the inflator and moves in the direction of the cover part. ing. The pressed plate transmits the pressed force to the cover part and cleaves it.

  Patent Document 2 discloses an airbag device that is folded around a disc-type inflator, and a cover portion that is provided with a tear line and that is easy to tear is installed on the upper portion of the airbag. Gas for inflating the airbag is supplied from the retainer outlet, and the outlet controls the flow of the gas so that the airbag, which is initially moved in the direction of the tear line, is inflated and deployed to easily tear the cover portion. .

Patent Document 3 discloses a double-structured airbag device having an inner bag on the inside and an airbag on the outside. The gas outlet of the inner bag located on the inner side controls the direction in which the airbag located on the outer side expands (expands) depending on the gas injection direction, thereby cleaving the cover portion.
JP-A-6-344851 JP-A-10-71910 JP 2000-85512 A

  In order to operate the airbag more reliably during a vehicle collision, it is important to cleave the cover portion that covers the airbag as described above. From this point of view, in the method of Patent Document 1, the distance that the plate moves is limited by the length of the pin that supports the movement of the plate, and the force of the plate may not be sufficiently transmitted to the cover portion.

  In the method of Patent Document 2, it is an airbag folded around a disk-type inflator that cleaves the cover portion. Even if the cover part is pinpoint, it breaks when a certain amount of force is applied. However, an air bag that has a large capacity and is intended to be inflated and deployed over a wide range is difficult to increase its internal pressure and is transmitted to the cover part. Since the force is dispersed, there is a possibility that the cover portion cannot be cleaved stably.

  In the method of Patent Document 3, it is an airbag that cleaves the cover part, and the inner bag itself controls only the gas injection direction without being deformed. Therefore, as in the method of Patent Document 2, since the force transmitted from the airbag to the cover portion is dispersed, the cover portion may not be stably cleaved.

  The present invention has been made in view of the above situation, and at the initial stage of inflating and deploying an airbag, the cover portion is more reliably cleaved to achieve both inflating and deploying the airbag and subsequent occupant restraint performance. An object of the present invention is to provide an airbag apparatus having a structure that operates more reliably.

  In order to solve the above-described problem, in a typical configuration of an airbag device according to the present invention, an airbag device arranged to face a vehicle seat, an inflator, and an airbag inflated and deployed by gas from the inflator A pre-expansion chamber that is disposed between the inflator and the air bag, has a smaller capacity than the air bag, receives a gas supply from the inflator first, and has a folding portion that expands by the gas supply, and covers the air bag from the outside The pre-expansion chamber is protruded when the folding portion is extended, and the cover portion is cleaved.

  According to said structure, the preliminary | backup expansion | swelling chamber which has a folding part extended by supply of gas protrudes, pushes up a cover part, and cleaves a cover part.

  As described above, since the capacity of the preliminary inflating chamber is smaller than that of the airbag, the internal pressure during inflation and deployment is much higher than the internal pressure of the airbag. Therefore, the preliminary expansion chamber protrudes with an internal pressure sufficient to cleave the cover part, and the cover part can be cleaved more reliably. Since the preliminary expansion chamber has a small capacity, a high internal pressure can be obtained even if a low-power inflator is used. As described above, the pre-expansion chamber is inflated and deployed within a limited range until it reaches the cover part while reliably cleaving the cover part with a high internal pressure, so that the injury value given to the occupant is not increased. .

  Since there is an air bag between the pre-expansion chamber and the cover part to be cleaved, the impact that the pre-expansion chamber inflates and protrudes is alleviated by the air bag and is not directly transmitted to the occupant. In this respect as well, an increase in the injury value given to the occupant can be suppressed.

  Although the internal pressure of the airbag that is inflated and deployed is sufficient to protect the occupant, although it is lower than the internal pressure of the pre-inflation chamber, the occupant is protected from the impact of a vehicle collision against the occupant in the normal seating position. Sufficient restraint (maximum bag reaction force characteristics) is obtained.

  The preliminary expansion chamber may include a communication hole that supplies gas from the inflator to the airbag. Since the communication hole is provided, gas starts to be supplied to the airbag through the communication hole when the gas is supplied to the preliminary expansion chamber. Even if the airbag has a large volume and a low internal pressure compared to the pre-expansion chamber, even if the cover part may not be cleaved alone, at least the cover part is pressed by gas supply, and the cover part is cleaved. If you can, it will be ready to jump out. Therefore, if the pre-expansion chamber having a small volume and a high internal pressure cleaves the cover part, the airbag can be deployed outward very quickly.

  The pre-expansion chamber and the air bag may be formed into a double bag shape having a common opening, which is an inner bag and an outer bag, respectively, and the opening may cover the gas ejection hole of the inflator.

  If the common opening of the double bag that allows gas to flow freely through the communication hole covers the gas injection hole of the inflator, the same inflator (gas source) can be used to efficiently install the preliminary expansion chamber and the airbag. This is because it can be inflated.

  The communication hole may guide the gas from the preliminary expansion chamber in a direction substantially perpendicular to the direction in which the preliminary expansion chamber protrudes.

  The folding part may have higher rigidity than the cloth used for the airbag. This is because the cover portion is surely cleaved in the preliminary expansion chamber.

  The folding part may be made of metal, synthetic resin, or cloth. By using a flexible material such as metal or synthetic resin, or by using cloth, the folding part is folded around the preliminary expansion chamber so as to form wrinkles or folds on the outside. Because it is. The folding part of such a material expands when a tensile force converted from an increase in internal pressure is applied.

  According to the gas guided by the direction of the communication hole described above, the airbag first spreads to the periphery so as to have a sufficiently large area to support the head and upper body of the occupant, not the direction approaching the occupant. It expands in the direction to go. Thereafter, the airbag is inflated in a direction in which the thickness of the airbag increases (direction approaching the occupant). Such an airbag is less damaging to the occupant than an airbag that inflates so as to approach the occupant from the beginning of inflation, especially when the occupant's head is located near the steering wheel, etc. Thus, it is possible to reduce the harm to occupants who are in different seating positions.

  According to the present invention, by supplying low pressure inflation gas generated from the inflator to the preliminary inflation chamber at the initial stage of inflation and deployment of the airbag, the preliminary inflation chamber protrudes, and the cover portion is cleaved by the projected preliminary inflation chamber. Thus, it is possible to achieve both the inflation and deployment of the airbag and the subsequent occupant restraint performance.

  Next, an embodiment of an airbag device according to the present invention will be described in detail with reference to the accompanying drawings. In the figure, elements not directly related to the present invention are not shown. Similar elements are denoted by the same reference numerals. Note that dimensions, materials, and other specific numerical values shown in the following embodiments are merely examples for facilitating understanding of the invention, and do not limit the present invention unless otherwise specified.

(First embodiment)
FIG. 1 is a diagram illustrating a driver seat airbag device according to a first embodiment of the present invention. In general, among the airbag devices for vehicles, the airbag device for the driver's seat is the one with the limited allowable space, and the designer has been devised to implement the airbag device for the driver's seat. This will be described as a form.

  As illustrated in FIG. 1, the driver airbag device 100 is incorporated in a steering wheel 110. FIG. 1A is a front view, and FIG. 1B is a right side view showing a case where the airbag is inflated and deployed. The steering wheel 110 is constituted by a steering spoke 120 constituted by two pieces each on the left and right sides and a substantially circular steering rim 130, and a driver seat airbag device 100 is incorporated in a central cover portion. Actually, there is a cosmetic cover surrounding the left and right steering spokes 120, but in this embodiment, illustration is omitted for convenience of explanation.

  The cover 150 at the center of the steering wheel 110 is cleaved when an airbag 140 described later is inflated and deployed, and guides the airbag 140 into the vehicle interior. An emblem installation unit 160 is provided at the center of the cover unit 150, and a tear line (also referred to as a cleavage line) 170 is provided in the vicinity of the emblem installation unit 160. The tear line 170 is formed with a continuous groove portion having a substantially triangular cross section so that the cover portion 150 is easy to tear at the initial stage of inflation and deployment of the airbag 140, and is thin with the corner portion of one vertex of the substantially triangular shape facing the surface. It has become.

  In the present embodiment, the pattern of the tear line 170 provided on the cover 150 is a single character illustrated in FIG. 1A, but may be a Y shape, a cross shape, an H shape, a circular shape, a rectangular shape, or the like. These may be combined.

  In the airbag 140, a tether (also called a hanging string) 172 that is a shape control member that forms an inflated and deployed shape, or a diffuser 180 that is a gas flow deflecting member that controls the direction of the gas to be ejected is installed. . The tether 172 or the diffuser 180 is fixed to a base fabric or a component near the bottom of the airbag 140.

  FIG. 2 is a perspective view of the driver seat airbag device of FIG. 1, illustrating the side attached to the vehicle body. A horn bracket 190 is installed at the lowermost portion of the driver airbag device 100, and the horn bracket 190 is attached to an assembly nut (three locations) 210 via a horn switch contact 200b (FIG. 3). It is fixed to a housing 220 which is a substrate member. A cover 150 is fixed to the housing 220 on the inside of the vehicle, and a disk-type inflator 230 (hereinafter, the inflator will be described as a disk-type inflator) is fixed to the outside of the vehicle by fixing nuts (four locations) 240.

  FIG. 3 is an assembly diagram illustrating assembly of the driver airbag device of FIG. 2. With reference to FIG. 3, the structure of the airbag apparatus 100 for driver's seats is demonstrated. The housing 220 includes a part of the side wall for accommodating the airbag 140 and a cover 150 formed with a part of the side wall for accommodating the airbag 140 at the upper part, and further includes a horn switch contact 200a. In the vicinity thereof, a coupling portion for the horn bracket 190 is provided, and a mounting portion for the disc-type inflator 230 is provided at the lower portion. The disc-type inflator 230 is provided with a plurality of gas ejection holes 250 for supplying gas to the airbag 140 and a pre-expansion chamber described later.

  By tightening the fixing nut 240 into the assembly bolt 270 via the housing 220 provided in the retainer ring 260, the assembly bolt 270 is arranged in the order of the airbag 140, the housing 220, and then the disk-type inflator 230. And is fixed by a fixing nut 240 which is a set screw. This fixing also serves to prevent leakage of the expanded gas.

  The insulating piece 280 is inserted into the horn bracket 190 from the direction shown in the figure, the horn switch coil spring 290 is inserted, and the horn switch contact 200b of the horn bracket 190 matches the horn switch contact 200a of the housing 220. As described above, it is fixed to the housing 220 by the mounting nut 210.

  4 is a cross-sectional view taken along the line AA in FIG. 1A, and illustrates a normal state before the driver airbag device 100 in FIG. 2 is inflated and deployed. An assembly bolt 270 is fixed to the retainer ring 260 accommodated in the airbag 140 by press-fitting, caulking, or a combination thereof, and the airbag 140 is fixed to the housing 220. The cover 150 is fixed to the housing 220 by pop rivets 292 provided at least at two places.

  The housing 220 is provided with a through hole having a diameter larger than that of the disk inflator 230 at the center. There is a preliminary expansion chamber 300 on one side (inner side of the vehicle) of the housing 220, and the preliminary expansion chamber 300 is formed by a retainer ring 260, a folding portion 310 located on a side surface, and a dome-shaped ceiling portion 320. Yes.

  As shown in FIG. 4, the pre-expansion chamber 300 and the airbag 140 are in the shape of a double bag having a common opening, which are inner and outer bags, respectively. The opening is a portion where the retainer ring 260 and the airbag 140 are in contact with each other, and covers the gas ejection hole 250 of the disc-type inflator 230.

  A communication hole 330 is provided at the boundary between the folding part 310 and the ceiling part 320 to supply the gas ejected from the inflator 230 from the inside of the preliminary inflating chamber 300 to the inside of the airbag 140. A disc-type inflator 230 enters the through hole of the housing 220 from the other side (the vehicle outer side) of the housing 220.

  As described above, the common opening of the double bag-like pre-expansion chamber 300 and the air bag 140 that allows gas to flow freely through the communication hole 330 covers the gas ejection hole of the disc-type inflator 230. . Therefore, the preliminary inflating chamber 300 and the airbag 140 can be efficiently inflated using the same inflator 230 (gas source).

  In this embodiment, the material of the ceiling part 320 and the folding part 310 of the preliminary expansion chamber 300 is a metal or a resin. Specifically, stainless steel, copper alloy, aluminum material, and synthetic resin are preferable. At least the folding part 310 is preferably made of a flexible material.

  The folding part 310 is a bellows in which a flexible material is folded so as to form wrinkles or folds on the side surface of the pre-expansion chamber 300. The bellows is extended by applying a tensile force converted from an increase in pressure generated inside the bellows.

  FIG. 5 is a perspective view illustrating the driver seat airbag device 100 of FIG. 4. For the sake of explanation, the airbag 140 and the cover 150 are not shown. The communication holes 330 for supplying gas to the airbag 140 are oval in the present embodiment and are provided in three directions. However, the number of communication holes may be singular or two or more, and the shape is not limited to an ellipse, and there is no problem with a round shape or an oval shape. When the communication hole 330 is round, the diameter is preferably 10 to 20 mm.

  The operation of the driver airbag device 100 having the above structure will be described below.

  The gas supplied from the gas ejection holes 250 of the disk type inflator 230 passes between the disk type inflator 230 and the retainer ring 260 and is guided to the preliminary expansion chamber 300. The gas guided to the preliminary expansion chamber 300 increases the internal pressure of the preliminary expansion chamber 300 and presses the ceiling portion 320 of the preliminary expansion chamber 300. Thereby, the folding part 310 is extended by applying a tensile force, and the ceiling part 320 projects in the direction of the arrow in FIG.

  FIG. 6 illustrates the state after the driver airbag device 100 of FIG. 4 has been inflated and deployed. As the gas is supplied, the folding part 310 extends, the preliminary expansion chamber 300 protrudes, and the cover part 150 is pushed up and cleaved.

  The above-described tear line 170 is preferably installed at a location where the cover portion 150 is easily stressed by the pre-expansion chamber 300 pressing the cover portion 150 and is easily cleaved. Specifically, as shown in FIG. 1A, the tear line 170 may be provided in a region overlapping the preliminary expansion chamber 300 in the cover 150 viewed from the front of the steering wheel 110.

  Since the capacity of the preliminary inflating chamber 300 is 100 to 300 cc and is smaller than the capacity of the airbag 140 (within 40 to 60 L), the internal pressure during inflation and deployment is much higher than the internal pressure of the airbag 140. Therefore, the pre-expansion chamber 300 protrudes with an internal pressure sufficient to cleave the cover part 150, and the cover part 150 can be cleaved more reliably. Since the preliminary expansion chamber 300 has a small capacity, a high internal pressure can be obtained even if a low-power inflator is used. In this way, the preliminary expansion chamber 300 is inflated and deployed within a limited range until it reaches the cover part while reliably cleaving the cover part 150 with a high internal pressure. Do not raise.

  In addition, although the internal pressure of the airbag 140 that is inflated and deployed is a value that is sufficient to protect the occupant, although it is lower than the internal pressure of the preliminary inflating chamber 300, an impact caused by a vehicle collision against the occupant at the normal seating position. Sufficient restraint for protecting passengers from the vehicle is obtained.

  According to the structure of the present embodiment, since the airbag 140 is between the pre-expansion chamber 300 and the cover 150 to be cleaved, the impact that the pre-expansion chamber 300 expands and protrudes is alleviated by the air bag 140. , Not communicated directly to the crew. In this respect as well, an increase in the injury value given to the occupant can be suppressed.

  Further, since the communication hole 330 is provided, the gas starts to be supplied to the airbag 140 through the communication hole 330 when the gas is supplied to the preliminary expansion chamber 300. Even if the air bag 140 having a larger volume and lower internal pressure than the pre-expansion chamber 300 may not be able to cleave the cover part 150 alone, at least the cover part 150 is pressed by supplying gas, As soon as the portion 150 is cleaved, it will be able to jump out to the outside. Therefore, if the pre-expansion chamber 300 having a small volume and a high internal pressure cleaves the cover 150, the airbag 140 can be deployed to the outside very quickly.

  In the present embodiment, the communication hole 330 of the preliminary expansion chamber 300 guides the gas from the preliminary expansion chamber 300 in a direction substantially perpendicular to the direction in which the preliminary expansion chamber 300 protrudes. In other words, the airbag 140 is not first approached by the occupant, but is inflated in a direction that spreads to the periphery so as to have a sufficiently large area for supporting the occupant's head and upper body. Thereafter, the airbag 140 is inflated in a direction in which the thickness of the airbag 140 increases (a direction approaching the occupant). Compared with the airbag 140 that inflates so as to approach the occupant from the beginning of inflation, the airbag 140 is less harmful to the occupant, and in particular, the occupant's head is located in the vicinity of the steering wheel. In such a case, it is possible to reduce the harmfulness to the occupant in the sitting position different from normal.

(Second Embodiment)
FIG. 7 is a view illustrating another driver airbag device 400 according to the second embodiment of the present invention, and is a cross-sectional view similar to FIG. The description of the elements already described for the first embodiment is omitted. An assembly bolt 270 is fixed to the retainer ring 420 accommodated in the airbag 410 by press-fitting, caulking, or a combination thereof, and the airbag 410 is fixed to the housing 220.

  Unlike the first embodiment, the pre-expansion chamber 430 of the present embodiment is provided with a folding portion 440 in the ceiling portion of the pre-expansion chamber 430. The folding portion 440 of this embodiment is made of cloth and may be made of the same material as the base cloth of the airbag 410, but it is desirable to use a cloth having higher rigidity. The folding part 440 is folded so as to form wrinkles or folds. The retainer ring 420 and the folding portion 440 are fixed by a clamp 460 so that the expansion gas does not leak from the preliminary expansion chamber 430.

  FIG. 8 is a perspective view illustrating the driver airbag device 400 of FIG. As in FIG. 5, the airbag 410 and the cover part 150 are not shown. Also in this embodiment, the preliminary expansion chamber 430 is provided with a communication hole 450 that supplies the gas ejected from the inflator 230 from the inside of the preliminary expansion chamber 430 to the inside of the airbag 410. The communication hole 450 is disposed in the folding portion 440 of the preliminary expansion chamber 430. As in the first embodiment, there is no limitation on the number and shape of the communication holes 450.

  The gas supplied from the gas ejection holes 250 of the disk type inflator 230 passes between the disk type inflator 230 and the retainer ring 420 and is guided to the preliminary expansion chamber 430. The gas guided to the pre-expansion chamber 430 increases the internal pressure of the pre-expansion chamber 430 and extends the folding portion 440 of the pre-expansion chamber 430.

  FIG. 9 is a view illustrating a state after the driver airbag device 400 of FIG. 7 has been inflated and deployed. By supplying the gas, the folding portion 440 extends, the preliminary expansion chamber 430 protrudes, and the cover portion 150 is pushed up to be cleaved.

  Unlike the first embodiment, the preliminary expansion chamber 430 is made of cloth. However, since the capacity is smaller than that of the airbag 410, similarly to the first embodiment, even if a low-power inflator is used, a high internal pressure can be obtained, and the cover 150 is cleaved at a high internal pressure. Although the operation of the air bag 410 is made more reliable, it is inflated and deployed within a limited range until it reaches the cover portion, so that the injury value given to the occupant is not increased.

  The preferred embodiments of the present invention have been described above with reference to the accompanying drawings. However, the embodiments described above are preferred examples of the present invention, and other embodiments can be implemented or performed in various ways. Can be carried out. The invention is not limited to the detailed shape, size, configuration, and the like of the components shown in the accompanying drawings unless otherwise specified in the present specification. Expressions and terms used in the present specification are for the purpose of explanation, and are not limited thereto unless otherwise specified.

  Therefore, it is obvious for those skilled in the art that various changes and modifications can be conceived within the scope of the claims, and these naturally belong to the technical scope of the present invention. It is understood.

  The present invention can be applied to an airbag apparatus including an airbag that inflates and deploys to protect an occupant when an impact occurs in a vehicle due to a collision accident or the like.

It is a figure which illustrates the airbag apparatus for driver's seats which is the 1st Embodiment of this invention. It is a perspective view of the airbag apparatus for driver's seats of FIG. 1, and is a figure which illustrates the side attached to a vehicle body. FIG. 3 is an assembly diagram illustrating assembly of the driver seat airbag device of FIG. 2. It is AA sectional drawing of Fig.1 (a), and illustrates the normal state before the airbag apparatus for driver's seats of FIG. 2 inflate-deploys. FIG. 5 is a perspective view illustrating the driver seat airbag device of FIG. 4. The state after the airbag apparatus for driver's seats of FIG. 4 inflate-deploys is illustrated. It is a figure which illustrates the other airbag apparatus for driver's seats which is the 2nd Embodiment of this invention, and is sectional drawing similar to FIG. It is the perspective view which illustrated the airbag apparatus for driver's seats of FIG. It is a figure which illustrates the state after the airbag apparatus for driver's seats of FIG. 7 inflate-deploys.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100, 400 ... Driver airbag apparatus 110 ... Steering wheel 140, 410 ... Air bag 150 ... Cover part 170 ... Tear line 230 ... Disc type inflator 250 ... Gas ejection hole 300, 430 ... Pre-expansion chamber 310, 440 ... Folding part 320 ... Ceiling part 330, 450 ... Communication hole

Claims (6)

In the airbag device arranged to face the vehicle seat,
An inflator,
An airbag that is inflated and deployed by gas from the inflator;
A pre-expansion chamber that is disposed between the inflator and the airbag, has a capacity smaller than that of the airbag, receives a gas supply from the inflator first, and has a folding portion that extends by the gas supply;
A cover portion that covers the airbag from the outside,
The airbag device according to claim 1, wherein the pre-expansion chamber protrudes when the folding portion is extended to cleave the cover portion.   The airbag apparatus according to claim 1, wherein the preliminary expansion chamber includes a communication hole that supplies gas from the inflator to the airbag. The pre-expansion chamber and the airbag are in a double bag shape having a common opening, which are inner and outer bags, respectively.
The airbag device according to claim 1 or 2, wherein the opening covers a gas ejection hole of the inflator.   The airbag device according to claim 2 or 3, wherein the communication hole guides gas from the preliminary expansion chamber in a direction substantially perpendicular to a direction in which the preliminary expansion chamber protrudes.   The airbag device according to any one of claims 1 to 4, wherein the folding portion has higher rigidity than a cloth used for the airbag.   The airbag device according to any one of claims 1 to 5, wherein the folding portion is made of metal, synthetic resin, or cloth.

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