Patent Description:
Airbag devices have generally become standard equipment in vehicles in recent years. An airbag device is a safety device that is operated in the event of an emergency such as a vehicle collision to receive and protect a passenger by inflating and deploying an airbag cushion with gas pressure.

There are various types of airbag devices depending on the installation site and application. For example, a front airbag device is provided in the center of a steering wheel to protect the driver from a collision in the front-back direction. In addition, to protect the occupant from an impact from a vehicle width direction due to a side-impact collision or the like, a curtain airbag device is provided near a ceiling above a side window, and a side airbag device is provided in a side portion of the seat.

It is desirable that the airbag cushion be able to inflate and deploy more smoothly in order to improve restraint performance. For example, with the side-impact collision airbag device (side airbag) described in Patent Document <NUM>, a strap <NUM> (an upper strap portion <NUM> and a lower strap portion <NUM>) is provided outside of an airbag <NUM> to inhibit unnecessary movement of the airbag <NUM>.

Patent Document <NUM> describes that tensioning of the strap regulates movement of the airbag such that the airbag rotates toward the front of the vehicle when inflated and deployed. However, the strap of Patent Document <NUM> is a band-like member that is long in the front-back direction, and there is a concern that the strap could become loose, and thus there is room for improvement to efficiently apply tension to the airbag. From the documents <CIT>, <CIT>, and <CIT> are known further side airbag devices comprising a front chamber and a rear chamber with different tethers to influence the inflation characteristics. From the document <CIT> it is known a side airbag device with an inflator, which is attached via two stud bolts, which are also used to attach a tether, which tensions the airbag during the inflation.

In light of the problems described above, an object of the present invention is to provide a side airbag device that can improve restraint performance by efficiently suppressing oscillation of the airbag cushion. Means for Solving the Problem.

In order to solve the above problems, a representative configuration of a side airbag device according to the present invention is provided according to claim <NUM>.

The first tether is configured to be shorter in the front-back direction, and therefore is more strongly tensioned in the front-back direction. Also, because the first tether is long in the vertical direction, the edge of the front end is also vertically long, and can be connected over a long range with the rear chamber. With such a first tether, tension can be efficiently applied to the rear chamber, and movement of the rear chamber in the front-back direction can be efficiently restricted. Here, the rear chamber is a portion that contains the inflator and is positioned at the base of the entire airbag cushion. The rear chamber is also small in capacity and quickly reaches a high pressure state immediately after operation of the inflator. Thus, the first tether is also rapidly and strongly tensioned. Accordingly, with the configuration described above, the first tether supports the rear chamber of the base of the airbag cushion with a strong tension, and thereby prevents oscillation of the entire airbag cushion, and improves the restraint performance of the airbag cushion. The side airbag device further include two stud bolts provided longitudinally spaced apart at the inflator, exposed from the rear chamber, and fastened to the vehicle seat, and the rear end of the first tether is anchored to the rear part of the rear chamber across the two stud bolts. Through this configuration, the first tether can be efficiently tensioned. The front end of the first tether has a length greater than or equal to a distance between the two stud bolts. By configuring the first tether in this manner, tension can be efficiently applied to the rear chamber. The front end of the first tether described above is connected to a range of the front edge portion of the rear chamber, the range including a location of the shortest distance to the stud bolts. By configuring the first tether in this manner, tension can be efficiently applied to the rear chamber.

The side airbag device further includes a cloth-like second tether that is provided outside of the front chamber and the rear chamber, has a front end connected to a front edge portion of the front chamber and a rear end connected to a rear part of the rear chamber, and is tensioned when the rear chamber is inflated and deployed, wherein the rear end of the second tether is anchored by at least one of the two stud bolts at the rear part of the rear chamber. Through this configuration, the second tether can be efficiently tensioned to apply tension to the front chamber, wherein the second tether is longer in the front-back direction than in the vertical direction.

By providing the second tether described above, oscillation in the vehicle width direction originating at the boundary between the front chamber and the rear chamber can be prevented.

Through such a configuration, a second tether that prevents oscillation of the front chamber is realized.

The front end of the second tether above may be connected to the front edge portion of the front chamber in a range that is longer than a range in which the rear end of the second tether is connected to the rear part of the rear chamber. Through this configuration, the second tether can efficiently pull the front chamber and prevent oscillation thereof.

The length from the front end to the rear end of the second tether above may be shorter than a length of a path extending from the front edge portion of the front chamber to the rear part of the rear chamber when the front chamber and the rear chamber are inflated and deployed without bending. A second tether of this length can be efficiently tensioned in accordance with the inflation and deployment of the front and rear chambers.

According to the present invention, a side airbag device that can improve restraint performance by efficiently suppressing the oscillation of an airbag cushion can be provided.

<NUM>: Side airbag device, <NUM>: seat, <NUM>: seat back, <NUM>: cushion, 106a: left side main panel, 106b: right side main panel, <NUM>: inflator, 110a: upper stud bolt, 110b: lower stud bolt, <NUM>: first tether, <NUM>: second tether, <NUM>: rear chamber, <NUM>: front chamber, <NUM>: rear chamber bolt hole, <NUM>: front end of first tether, <NUM>: front edge portion of rear chamber, <NUM>: rear end of first tether, <NUM>: first tether bolt hole, <NUM>: front end of second tether, <NUM>: front edge portion of front chamber, <NUM>: rear end of second tether, <NUM>: bolt hole of second tether, <NUM>: baffle, <NUM>, <NUM>: vent hole, <NUM>: inner tether, <NUM>: lower end of front edge portion of rear chamber, <NUM>: modified second tether, <NUM>: front end of modified second tether, <NUM>: rear end of modified second tether, <NUM>: upper side of modified second tether, <NUM>: lower side of modified second tether, D1: distance between stud bolts, <NUM>: conventional cushion.

Preferred embodiments according to the present invention will hereinafter be described in detail with reference to the appended drawings. The dimensions, materials, other specific numerical values, etc. indicated in such embodiments are mere exemplifications for ease of understanding of the invention and do not limit the present invention unless otherwise noted. Note that in the present specification and drawings, elements having substantially identical functions and configurations are labeled with identical symbols to omit redundant descriptions along with the illustration of elements not directly related to the present invention.

<FIG> are views illustrating an example of a side airbag device according to an embodiment of the present invention. <FIG> illustrates, from a right side in the vehicle width direction, or in other words, from the outside in the vehicle width direction (vehicle outer side), a side airbag device <NUM> and a vehicle left side seat <NUM> in which the side airbag device <NUM> is incorporated. In <FIG> and all other drawings of the present application, the vehicle forward and back directions are illustrated with respective arrows F (forward) and B (back), left and right in the vehicle width direction are illustrated by respective arrows L (left) and R (right), and the vehicle vertical direction is illustrated by respective arrows U (up) and D (down).

As illustrated in <FIG>, the side airbag device <NUM> is installed inside a seat back <NUM> at the inner side in the vehicle width direction (vehicle inner side) of the seat <NUM> in the present embodiment. The side airbag device <NUM> is configured including an airbag cushion (cushion <NUM>) that restrains the occupant and an inflator <NUM> that delivers gas to the cushion <NUM>. The cushion <NUM> is wound or folded prior to operation, and is housed in a housing or such built into the side portion of the seat back <NUM> at the vehicle inner side. The cushion <NUM> in the housed state is covered with a seat cover, etc. and therefore is not visible from the outside.

The inflator <NUM> is a gas generating device, and in the embodiments, a cylinder-shaped (cylindrical) inflator is adopted. The inflator <NUM> is contained in a rear part of a rear chamber <NUM> (described below) of the cushion <NUM>, and is oriented so as to be longitudinal in the vertical direction along the seat back <NUM>. The inflator <NUM> is electrically connected to the vehicle side, and when a signal originating from the detection of an impact from the vehicle side is received, the inflator <NUM> operates and supplies gas to the cushion <NUM>.

Examples of inflators that are currently used on a widespread basis include a type that is filled with a gas generating agent and combusts the agent to generate a gas, a type that supplies gas without generating heat by being filled with compressed gas, or a hybrid type that utilizes both combustion gas and compressed gas. Any type of inflator can be used as the inflator <NUM>.

The inflator <NUM> is provided with two stud bolts 110a and 110b separated in the longitudinal direction thereof. The stud bolts 110a and 110b are exposed to the outside by piercing through a base fabric of the cushion <NUM>, and are fastened and fixed to a frame or the like of the seat back <NUM>. The stud bolts 110a and 110b pierce through the cushion <NUM> and are fastened to the seat back <NUM>, and thereby the cushion <NUM> is also attached to the seat back <NUM>.

<FIG> is a view illustrating a state after the cushion <NUM> of <FIG> is inflated and deployed. When a sensor provided in the vehicle detects an impact, an operation signal is sent to the inflator <NUM>, gas is discharged, and the cushion <NUM> uses the gas to exit the covering or the like of the seat cushion <NUM> and inflate and deploy into the cabin space.

The cushion <NUM> inflates and deploys into an overall flat shape. The exterior surface of the cushion <NUM> is configured by a main panel 106a on the left side in the vehicle width direction and a main panel 106b on the right side in the vehicle width direction. The main panels 106a and 106b are made from a base fabric and are formed in an overall bag shape by sewing, adhesion, or the like. Note that the cushion <NUM> can be formed by weaving using a One-Piece Woven (OPW) fabric or the like.

In the present embodiment, two tethers (first tether <NUM> and second tether <NUM>) are provided outside of the cushion <NUM> to suppress oscillation of the cushion <NUM>. The configuration of the cushion <NUM> will be described further below with focus on the configuration and function of each tether.

<FIG> are side views of the airbag cushion <NUM> of <FIG>. <FIG> illustrates a general overview of the cushion <NUM>. The first tether <NUM> and the second tether <NUM> are bridged over the outside of the cushion <NUM>. Each of these tethers is a cloth-like member, and for example, is formed from the same type of base fabric as the main panel 106a and such. The first tether <NUM> and the second tether <NUM> are both tensioned when the cushion <NUM> is inflated and deployed, and apply tension to the cushion <NUM> to thereby suppress oscillation of the cushion <NUM>.

<FIG> is a view with the first tether <NUM> and the second tether <NUM> removed from the cushion <NUM> of <FIG>. Prior to describing each tether, each portion of the cushion <NUM> will be described in detail.

The interior of the cushion <NUM> is demarcated by a rear chamber <NUM> and a front chamber <NUM>. The rear chamber <NUM> is a portion located at the base of the cushion <NUM>, and is formed at a lower part of the vehicle back side. The rear chamber <NUM> has a vertically long shape along the seat back <NUM> (see <FIG>).

The rear chamber <NUM> is provided with two bolt holes <NUM> through which are passed stud bolts 110a and 110b in order to internally provide the inflator <NUM> (see <FIG>) described above. The rear chamber <NUM> has a smaller capacity than the front chamber <NUM> and rapidly reaches a high pressure state immediately after operation of the inflator <NUM>. The rear chamber <NUM> rapidly cleaves the covering of the seat back <NUM> and allows for quicker inflation and deployment of the overall cushion <NUM>.

The first tether <NUM> is provided outside of the rear chamber <NUM>, and a front end <NUM> is connected to a front edge portion <NUM> of the rear chamber <NUM>, and a rear end <NUM> is connected to a rear part of the rear chamber <NUM>. In the present embodiment, the rear end <NUM> of the first tether <NUM> is provided with two bolt holes <NUM> and is anchored by two stud bolts 110a and 110b at the rear part of the rear chamber <NUM>.

The length of the first tether <NUM> from the front end <NUM> to the bolt hole <NUM> is shorter than a length in the vehicle front-back direction from the front edge portion <NUM> to the bolt hole <NUM> when the rear chamber <NUM> is expanded. This configuration allows the side airbag device <NUM> to efficiently tension the first tether <NUM>. As a result, the first tether <NUM> is tensioned in association with the inflation and deployment of the rear chamber <NUM> to pull the front edge portion <NUM> of the rear chamber <NUM> to the rear of the vehicle, thereby suppressing oscillation of the rear chamber <NUM>.

The front chamber <NUM> is a portion that widely inflates and deploys forward and above from the rear chamber <NUM>, and is formed abutting the front edge portion <NUM> of the rear chamber <NUM>. The front chamber <NUM> is inflated and deployed from the seat back <NUM> to a range in which an occupant in a forward part of the vehicle is present, and actively restrains the occupant.

The second tether <NUM> is provided outside of the front chamber <NUM> and the rear chamber <NUM>, and a front end <NUM> is connected to a front edge portion <NUM> of the front chamber <NUM> and a rear end <NUM> is connected to the rear part of the rear chamber <NUM>. In the present embodiment, the rear end <NUM> of the second tether <NUM> is provided with a bolt hole <NUM>, and is anchored by one of the stud bolts 110a and 110b (for example, the stud bolt 110a) at the rear part of the rear chamber <NUM>.

The second tether <NUM> also has a length in the vehicle front-back direction extending from the front end <NUM> to the bolt hole <NUM> of the rear end <NUM> that is shorter than a length of a path in the vehicle front-back direction extending from the front edge portion <NUM> of the front chamber <NUM> to the bolt hole <NUM> when the inflated and deployed cushion <NUM> is expanded without being folded. This configuration allows the side airbag device <NUM> to efficiently tension the second tether <NUM>. Through this, the second tether <NUM> is tensioned in association with the inflation and deployment of the front chamber <NUM> and the rear chamber <NUM> to primarily suppress oscillation of the front chamber <NUM>.

<FIG> is a detailed view of the airbag cushion <NUM> of <FIG>, and corresponds to <FIG>. A baffle <NUM> partitioning the rear chamber <NUM> and the front chamber <NUM> is provided inside the cushion <NUM>. The baffle <NUM> is a wall-shaped portion formed using the same type of base fabric as the main panel 106a and the like, and is connected to the main panels 106a and 106b across the vehicle width direction. The baffle <NUM> is provided with a plurality of vent holes <NUM> and <NUM> and other features. The vent holes <NUM> and <NUM> are gas distribution ports through which gas passes from the rear chamber <NUM> side to the front chamber <NUM> side.

An internal tether <NUM> is also provided in the cushion <NUM>. The internal tether <NUM> is also formed using the same type of base fabric as the main panels 106a and 106b, is connected to the main panels 106a and 106b across the vehicle width direction, and regulates the width of the cushion <NUM> in the vehicle width direction. In addition, a predetermined outer vent (not illustrated) for discharging gas to the outside is also provided in a predetermined location of the cushion <NUM>.

The front end <NUM> of the first tether <NUM> can be also be similarly connected to the main panel 106a by sewing, for example, along a location of sewing the baffle <NUM> to the main panel 106a. The first tether <NUM> has a shape that is longer in the vertical direction than in the front-back direction, and in particular, the front end <NUM> is formed with a length that is equal to or greater than a distance D1 between the two stud bolts 110a and 110b. The first tether <NUM> is short in the vehicle front-back direction, and the front end <NUM> is also vertically long, and through such a configuration, the first tether <NUM> can apply a strong tension that pulls the rear chamber <NUM> to the rear of the vehicle in a wide vertical range, and can thereby suppress oscillation of the rear chamber <NUM>.

The front end <NUM> of the first tether <NUM> is connected to a range that includes at least a lower end <NUM> of the front edge portion <NUM> of the rear chamber <NUM>. Here, the cushion <NUM> as a whole inflates and deploys forward and diagonally upward because the inflator <NUM> is contained within a rearward lower part. At this time, the front end <NUM> of the first tether <NUM> supports the lower end <NUM> of the rear chamber <NUM>, and thereby oscillation of the entire cushion <NUM> can be efficiently suppressed.

<FIG> is an enlarged view near the rear chamber <NUM> of <FIG>. The front end <NUM> of the first tether <NUM> is connected to a range including locations P1 and P2 of the front edge portion <NUM> of the rear chamber <NUM>, with the locations P1 and P2 being locations of the shortest distance to the stud bolts 110a and 110b. By configuring the first tether <NUM> in this manner, the area between the stud bolts 110a and 110b and the front edge portion <NUM> of the rear chamber <NUM> is efficiently tensioned, and tension can be efficiently applied to the rear chamber <NUM> to suppress oscillation.

Reference is made once again to <FIG>. The second tether <NUM> is configured to be longer in the front-back direction than in the vertical direction. Through such a configuration, the second tether <NUM> extends from the stud bolt 110a to the front edge portion <NUM> of the front chamber <NUM> and can prevent oscillation of the front chamber <NUM>.

In the present embodiment, the range of connection between the front end <NUM> of the second tether <NUM> and the front edge portion <NUM> of the front chamber <NUM> is sewn in a much longer range than the range in which the rear end <NUM> of the second tether <NUM> connects to the rear part of the rear chamber <NUM> (the range through which the stud bolt 110a penetrates). With this configuration, when the cushion <NUM> is inflated and deployed, the second tether <NUM> can efficiently pull the front edge portion <NUM> of the front chamber <NUM> toward the stud bolt 110a side, and can efficiently prevent oscillation of the front chamber <NUM> and the cushion <NUM> overall.

<FIG> are views illustrating the conditions when the airbag cushion <NUM> of <FIG> is inflated and deployed. <FIG> is a view of the cushion <NUM> from the vehicle outer side, and illustrates with a virtual line the movement of a cushion <NUM> in the vehicle front-back direction. As illustrated in <FIG>, the conventional cushion <NUM> may tilt forward or reactively tilt backwards due to the pressure of gas supplied from the inflator.

The cushion <NUM> of the present embodiment however is tensioned by the first tether <NUM>, and thereby the rear chamber <NUM> is supported. The rear chamber <NUM> is a portion that contains the inflator <NUM> (see <FIG>, etc.) and is positioned at the base of the entire cushion <NUM>. The rear chamber <NUM> is also small in capacity and quickly reaches a high pressure state immediately after operation of the inflator <NUM>. Thus, the first tether <NUM> is also rapidly and strongly tensioned. Thus, according to the present embodiment, the rear chamber <NUM> at the base of the cushion <NUM> is supported with strong tension by the first tether <NUM>, and thereby oscillation in the front-back direction of the overall cushion <NUM> is prevented, and the restraint performance of the cushion <NUM> can be increased.

<FIG> is a schematic view of the cushion <NUM> as viewed from above, and illustrates with a virtual line the movement of the cushion <NUM> in the vehicle width direction. The conventional cushion <NUM> may also oscillate in the vehicle width direction due to the pressure of the gas. However, in the present embodiment, in addition to the first tether <NUM> described above, the second tether <NUM> is tensioned and applies tension to the front chamber <NUM> to pull the front chamber <NUM> toward the rear of the vehicle. Accordingly, oscillation of the cushion <NUM> in the vehicle width direction, and in particular, oscillation in the vehicle width direction originating at the boundary line between the front chamber <NUM> and the rear chamber <NUM> can be prevented.

As described above, the side airbag device <NUM> of the present embodiment can efficiently suppress oscillation of the cushion <NUM> and improve the restraint performance of the cushion <NUM> through use of the first tether <NUM> and the second tether <NUM>. Although the first tether <NUM> and the second tether <NUM> are both provided at the occupant side of the cushion <NUM> in the present embodiment, the tethers thereof may also be provided at the side opposite the occupant, or one may be provided at the occupant side and the other provided at the side opposite the occupant.

Additionally, in the present embodiment, description is given with the assumption that the cushion <NUM> is provided at the vehicle inner side of the seat back <NUM>. Because there is no support structure for the cushion <NUM>, such as a side door, at the vehicle inner side of the seat back <NUM>, the first tether <NUM> and the second tether <NUM>, which suppress oscillation, function more favorably. However, the cushion <NUM> may of course be provided at the vehicle outer side of the seat back <NUM>, and in that case, the first tether <NUM> and the second tether <NUM> suppress oscillation, thereby improving the restraint performance of the cushion <NUM>.

<FIG> is a view illustrating a modified example of the second tether <NUM> (second tether <NUM>) of <FIG>. The second tether <NUM> is shaped in the form of a band with upper and lower sides that are nearly parallel, while the second tether <NUM> is shaped such that the vertical width of a front end <NUM> is wider than a vertical width of a rear end <NUM>, with an upper side <NUM> and a lower side <NUM> spread out in a non-parallel manner from the rear end <NUM> to the front end <NUM>. The second tether <NUM> of this configuration also allows the front end <NUM> to be sewn to the front edge portion <NUM> of the front chamber <NUM> in a longer range compared to the rear end <NUM>, to thereby efficiently pull the front edge portion <NUM> toward the rear end <NUM> side and prevent oscillation of the cushion <NUM>.

Although the second tether <NUM> of <FIG> and the second tether <NUM> of <FIG> are both illustrated as polygonal shapes in the drawings, the second tether is not limited to such a shape, and for example, the function of pulling the front chamber <NUM> toward the back side can be achieved even with a rounded shape such as an oval not having an angle in the contour. Even with a second tether having such a shape, the front chamber <NUM> can be efficiently pulled to the rearward side and oscillation of the cushion <NUM> can be suppressed by connecting the front end side of the second tether to the front edge portion <NUM> of the front chamber <NUM> in a range that is longer than the width on the rear end side.

Preferred embodiments of the present invention were described with reference to the appended drawings, however, it goes without saying that the present invention is not limited to such examples.

Moreover, examples in which the side airbag device according to the present invention was applied in a vehicle were described in the embodiments above, however, the present invention can also be applied to airplanes, ships, and other applications in addition to vehicles, and the same operations and effects can be obtained.

Claim 1:
A side airbag device (<NUM>) comprising:
a vertically long rear chamber (<NUM>) that inflates and deploys from a side portion of a vehicle seat (<NUM>);
a front chamber (<NUM>) that abuts a front edge portion of the rear chamber (<NUM>) and inflates and deploys forward and upward from the rear chamber (<NUM>);
a vertically long inflator (<NUM>) contained within a rear part of the rear chamber (<NUM>); and
a cloth-like first tether (<NUM>) that is provided outside of the rear chamber (<NUM>), has a front end (<NUM>) connected to the front edge portion of the rear chamber (<NUM>) and a rear end (<NUM>) connected to the rear part of the rear chamber (<NUM>), and is tensioned when the rear chamber (<NUM>) is inflated and deployed;
wherein:
the rear chamber (<NUM>) has a smaller capacity than the front chamber (<NUM>); wherein
the first tether (<NUM>) is longer in a vertical direction than in a front-back direction, and the front end (<NUM>) of the first tether (<NUM>) is connected to a range that includes at least a lower end of the front edge portion of the rear chamber (<NUM>);
the side airbag device (<NUM>) further comprising two stud bolts (110a,110b) provided longitudinally spaced apart at the inflator (<NUM>), exposed from the rear chamber (<NUM>), and configured to be fastened to the vehicle seat (<NUM>)
wherein the rear end of the first tether (<NUM>) is anchored to the rear part of the rear chamber (<NUM>) across the two stud bolts (110a, 110b), and
the front end of the first tether (<NUM>) has a length greater than or equal to a distance between the two stud bolts (110a, 110b), and
the front end of the first tether (<NUM>) is connected to a range of the front edge portion of the rear chamber (<NUM>), the range including a location of the shortest distance to the stud bolts (110a, 110b); characterized in that a cloth-like second tether (<NUM>) that is provided outside of the front chamber (<NUM>) and the rear chamber (<NUM>), has a front end (<NUM>) connected to a front edge portion of the front chamber (<NUM>) and a rear end connected to a rear part of the rear chamber (<NUM>), and is tensioned when the rear chamber (<NUM>) is inflated and deployed, wherein
the rear end of the second tether (<NUM>) is anchored by at least one of the two stud bolts (110a, 110b) at the rear part of the rear chamber (<NUM>) wherein
the second tether (<NUM>) is longer in the front-back direction than in the vertical direction.