Patent Description:
Airbag apparatuses have generally become standard equipment in vehicles in recent years. An airbag apparatus is a safety apparatus that is actuated in the event of an emergency such as a vehicle collision in order to catch and protect a passenger by inflating and deploying a bag shaped airbag cushion via gas pressure.

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

The airbag cushion of a typical side airbag apparatus is in a wound or folded housing form and housed in the side part of the seat. For example, in <FIG> of Patent Document <NUM>, as viewed from a passenger P1 of a seat <NUM>, an airbag <NUM> is provided on the impact position side (near side), while an airbag <NUM> is provided on the far side from the impact position. Moreover, in <FIG> of Patent Document <NUM>, as an airbag cushion provided other than a seat, an airbag <NUM> is provided in a console <NUM> between seats.

Presently, at sites developing airbag apparatuses, reducing the burden on the neck of a passenger during restraint has been found to be problematic. The technique of the abovementioned Patent Document <NUM> is designed to allow the side surface of the airbag <NUM> having a reversed truncated quadrangular pyramid to restrain both the shoulder and head of a passenger. Unfortunately, because the airbag <NUM> is large in size, it is difficult to readily carry out the technique of Patent Document <NUM> in terms of the installation position and costs.

In view of such problems, the present invention aims to provide a side airbag apparatus which can reduce the burden on a passenger when the passenger is restrained in a simple configuration with an improved efficient restraining of the head of the passenger.

In order to resolve the above problems, an exemplary configuration of a side airbag apparatus according to the present invention includes: an airbag cushion; and an inflator which supplies gas to this airbag cushion, wherein the airbag cushion includes: a main chamber; and a sub chamber; an inner tube which cylindrically extends inside the main chamber and contains the inflator, with a portion of the inner tube adjacent to the sub chamber; a main vent which is opened at a predetermined position of the inner tube so as to release gas from this inner tube into the main chamber; and a sub vent which penetrates through the inner tube and a panel of the main chamber so as to release gas from this inner tube into the sub chamber. Regarding the surface of the sub chamber on the passenger side, the central part is recessed on the main chamber in the horizontal cross section of the airbag cushion as viewed from above, and the recessed surface of the sub chamber on the passenger side is continuously curved from both ends of this surface in the anteroposterior direction of the vehicle to the central part.

According to the abovementioned configuration, the gas can be directly fed to the sub chamber through the inner tube, such that the sub chamber is expanded early. Consequently, at the same time as or slightly before the main chamber contacts the shoulder of the passenger, the sub chamber also contacts the head of the passenger. This allows the passenger to be restrained at a position which suppresses the displacement of the head, in addition to reducing the burden on the passenger. Moreover, the gas is distributed by the inner tube, making it possible to prevent the expansion pressure of the airbag cushion from locally concentrating in the initial stage of expansion and deployment. Consequently, for example, when the passenger contacts the airbag cushion in the state in which the passenger is in a position other than the normal seating position, etc., the passenger does not have to touch a region in which the expansion pressure has locally increased, making it possible to contribute to improving the safety of the airbag cushion. The sub chamber having this configuration can be expanded along the shape of the head of the passenger, in addition to efficiently restraining the head of the passenger.

The inner diameter of the sub vent may be larger than the inner diameter of the main vent. This configuration allows an increase in the inflow amount of the gas in the sub chamber per unit time, in addition to allowing the sub chamber to finish being expanded and deployed early on from the start of operation of the inflator.

The sub vent may have a check valve structure to prevent the gas from flowing out from the sub chamber to the inner tube. This configuration can maintain the expansion pressure of the sub chamber for longer periods of time.

The airbag cushion may further include a check valve capable of discharging the gas from the sub chamber to the main chamber. This configuration can appropriately suppress the expansion pressure of the sub chamber, in addition to preventing damage to the sub chamber.

The airbag cushion may be provided on the side part of the seat on the central side of the vehicle. This configuration potentially allows inertia to suitably restrain the passenger who will move to the side opposite the impact position upon a side collision.

The sub chamber may be coupled by sewing the panel of the main chamber. This configuration can suitably embody the sub chamber.

The sub chamber may finish being expanded and deployed earlier than the main chamber. According to this configuration, at the same time as or slightly before the main chamber touches the shoulder of the passenger, the sub chamber touches the head of the passenger, making it possible to restrain the head of the passenger at the position of suppressing the displacement thereof.

The present invention enables the provision of a side airbag apparatus which can reduce the burden on a passenger when the passenger is restrained in a simple configuration.

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 in order to omit redundant descriptions along with the illustration of elements not directly related to the present invention.

<FIG> is a view illustrating an example of a side airbag apparatus <NUM> according to an embodiment of the present invention. <FIG> illustrates, from the right side in the vehicle width direction on the front side of the vehicle, a side airbag apparatus <NUM> and a seat <NUM> of the vehicle in which the side airbag apparatus <NUM> is applied. Hereinafter, in <FIG> and other drawings, the anteroposterior direction of the vehicle is indicated by arrows F (forward) and B (back), respectively, the left and right in the width direction of the vehicle are respectively indicated by arrows L (left) and R (right), and the vertical direction of the vehicle is indicated by arrows U (up) and D (down), respectively.

In the present embodiment, the seat <NUM> is assumed to be disposed on the right side of the front row. However, the side airbag apparatus <NUM> can be installed on any seat of the front column, the back row, and on either left or right sides of the vehicle. Furthermore, while the seat <NUM> is normally directed toward the front side of the vehicle, it is also assumed that the seat <NUM> may be rotated to be directed toward the back side. Thus, the directions illustrated by the arrows in the drawings are not intended to be limited to the front, back, left, and right directions relative to the vehicle, with the direction of the front surface capable of being the "front" and the direction of the back side capable of being the "back" when viewed from the passenger regularly seated on the seat <NUM>. Similarly, the direction of the right hand of the passenger at this time is "right" and the left hand direction is "left. " Furthermore, the direction toward the head is "up," while the direction toward the leg is "down" with respect to the center of the body of the passenger at this time.

<FIG> illustrates a side airbag apparatus <NUM> before operation. An airbag cushion (hereinafter, a cushion <NUM>) is a member for catching a passenger and, in the present embodiment, is installed on the side far from the collision position on both side parts of the seat <NUM>. The cushion <NUM> is wound or folded into a housing form and, together with an inflator <NUM> for supplying gas, installed in an internal frame of a backrest <NUM> of the seat, etc..

<FIG> is a view illustrating a side airbag apparatus <NUM> upon operation. When a vehicle impact is detected, the cushion <NUM> utilizes the gas from the inflator <NUM> and is expanded and deployed to the side of the passenger seated in the seat <NUM> while pushing aside the skin of the seat <NUM>. The cushion <NUM> is formed by applying sewing, adhering, etc. to a base fabric, but can also be formed by weaving using a one-piece woven (OPW) fabric, etc..

The cushion <NUM> according to the present embodiment includes a main chamber <NUM> and a sub chamber <NUM> as expansion regions. The main chamber <NUM> is a region which widely restrains the upper body around the shoulder of the passenger and is expanded and deployed in an overall flat shape. The sub chamber <NUM> is a region for restraining the head of the passenger and is expanded and deployed so as to protrude from the main chamber <NUM> to the passenger side.

<FIG> is a view independently illustrating the cushion <NUM> in <FIG> in each direction. <FIG> is a side view obtained by viewing the cushion <NUM> in <FIG> from the seat <NUM> side. <FIG> illustrates the internal structure of the cushion <NUM> with broken lines.

The inflator <NUM> is a gas generating apparatus and, in the present embodiment, a cylinder-shaped (cylindrical) inflator is adopted. The inflator <NUM> has a gas jet hole <NUM> (see <FIG>) on the outer peripheral surface on one end side, along with a terminal <NUM> in which a predetermined harness is connected to the other end side. The entire inflator <NUM> or a portion thereof including the gas jet hole <NUM> is inserted from the lower part of the cushion <NUM> on the rear side of the vehicle. In addition, the inflator <NUM> is electrically connected to the vehicle side via the terminal <NUM>, wherein, 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>.

<FIG> is an A-A cross sectional view of the cushion <NUM> in <FIG>. A total of two stud bolts <NUM> for mounting are provided in the inflator <NUM>. The stud bolts <NUM> extend from a cylindrical main body of the inflator <NUM>, penetrate through the inner tube as well as through the panel of the main chamber <NUM>, and are fastened to the internal frame of the seat (see <FIG>), etc. When the stud bolts <NUM> of the inflator <NUM> are fastened to the seat, the cushion <NUM> can also be fixed to the seat.

Exemplary currently prevailing inflators include: a type which is filled with a gas generating agent and burns the agent to generate gas; a type which is filled with compressed gas and supplies gas without generating heat; or a hybrid type which utilizes both combustion gas and compressed gas, etc. Any type can be used for the inflator <NUM>.

As a member for distributing the gas from the inflator <NUM>, an inner tube <NUM> is provided inside the main chamber <NUM>. The inner tube <NUM> contains the inflator <NUM> and cylindrically extends inside the main chamber <NUM> in the vertical direction. A portion of the inner tube <NUM> on the upper end side is adjacent to the sub chamber <NUM>, enabling gas to be directly fed to the sub chamber <NUM>.

The material of the inner tube <NUM> is formed using the same chemical fibers as the base fabric making up the panel of the main chamber <NUM>, has sufficient flexibility, and can endure harsh temperature, pressure, etc. conditions upon operation of the inflator <NUM>. While the inner tube <NUM> according to the present embodiment has an elongated cylindrical configuration, the thickness (diameter) thereof can be set to dimensions (in which the inner pressure is not too high) in accordance with the output of the inflator <NUM>, etc..

As illustrated in <FIG>, two vent holes (a main vent <NUM> and a sub vent <NUM>) as holes for discharging the gas are provided in the inner tube <NUM>. The main vent <NUM> is opened at predetermined positions such as the center and the lower side of the inner tube <NUM> so as to release the gas from the inner tube <NUM> into the main chamber <NUM>. The sub vent <NUM> is opened on the upper end side of the inner tube <NUM> so as to release the gas from the inner tube <NUM> into the sub chamber <NUM>.

As illustrated in <FIG>, the sub chamber <NUM> is coupled by sewing the panel of the main chamber <NUM>. In addition, the sub vent <NUM> is formed by penetrating through the inner tube <NUM> as well as through the panel of the main chamber <NUM>. These configurations can suitably embody: the sub chamber <NUM> which is expanded and deployed so as to protrude from the main chamber <NUM> to the passenger side; and the inner tube <NUM> for directly feeding the gas to the sub chamber <NUM>.

Note that the inner diameter of the sub vent <NUM> can be appropriately set. For example, the inner diameter of the sub vent <NUM> can be set so as to be larger than the inner diameter of the main vent <NUM> (the inner diameter of the sub vent <NUM> > the inner diameter of the main vent <NUM>). This configuration can increase the inflow amount of the gas in the sub chamber <NUM> per unit time, in addition to allowing the sub chamber <NUM> to finish being expanded and deployed early on from the start of operation of the inflator <NUM>.

The present embodiment is configured such that the inflator <NUM> is inserted from the lower end side of the main chamber <NUM>, while the inner tube <NUM> also extends from the lower end of the main chamber <NUM> to the vicinity of the upper end thereof. However, for example, the position of the inflator <NUM> can be provided near the vertical center of the main chamber <NUM>. If the inflator <NUM> is installed at the vertical center of the main chamber <NUM>, the inner tube has dimensions allowing it to reach the sub chamber <NUM> from the vertical center of the main chamber <NUM>. Even in this configuration, the abovementioned the main vent <NUM> and sub vent <NUM> can be provided in the inner tube so as to distribute the gas into the main chamber <NUM> and the sub chamber <NUM>, in addition to expanding and deploying the sub chamber <NUM> early on.

<FIG> is a B-B cross sectional view of the cushion <NUM> in <FIG>. This B-B cross section is the horizontal cross section of the cushion <NUM> as viewed from above. The inner tube <NUM> is cylindrically provided on the rear side of the vehicle of the main chamber <NUM>, with the upper end side thereof disposed adjacent to the sub chamber <NUM>. As mentioned later, the sub chamber <NUM> is expanded and deployed into a curved and recessed shape so as to easily restrain the head of a passenger.

Regarding the surface <NUM> of the sub chamber <NUM> on the passenger side, the central part 134c is recessed on the main chamber <NUM> side in the anteroposterior direction of the vehicle. In particular, this surface <NUM> on the passenger side is continuously curved from both the front end 134a and the rear end 134b in the anteroposterior direction of the vehicle to the central part 134c. This configuration allows the sub chamber <NUM> to efficiently restrain the head of the passenger.

<FIG> is a view schematically illustrating the passenger P1 in the normal seating position in the seat <NUM> in <FIG> and the cushion <NUM> in <FIG>. Note that the passenger P1 is illustrated as a dummy doll which is utilized for collision testing of vehicles, etc. As an example, upon determining the specific physique of the passenger P1, for example, a side collision test dummy WorldSID 50th male imitating a physique adapted to <NUM>% of average adult males is available. However, without any problems, the technical ideas of this side airbag apparatus <NUM> can be carried out not only on a WorldSID 50th male, but also on other dummy dolls, as well as passengers with other physiques, etc..

The main chamber <NUM> is expanded and deployed within a wide range from the shoulder <NUM> to the head <NUM> of the passenger P1 in the normal seating position. The sub chamber <NUM> is expanded and deployed so as to protrude from the position above the shoulder <NUM> of the passenger P1 in the normal seating position to the passenger side in the main chamber <NUM>. At this time, the lower end <NUM> of the sub chamber <NUM> is set so as to be disposed above the upper end <NUM> of the shoulder <NUM> of the passenger P1. Moreover, the upper end <NUM> of the sub chamber <NUM> is set so as to be disposed above the height of the center of gravity <NUM> of the head of the passenger P1 by approximately the distance D1. The sub chamber <NUM> having this configuration can efficiently absorb and restrain the load of the head <NUM> of the passenger P1.

The center C1 of the sub chamber <NUM> in the vertical direction is set so as to be disposed in the vicinity of the height of the head of the center of gravity <NUM> of the passenger P1. The vicinity of the height of the center of gravity <NUM> of the head is presumed to be within a range of approximately ±<NUM>% of the head <NUM> in the direction generally vertical to the position of the center of gravity <NUM> of the head in the vertical direction and within a range that can be regarded as substantially the same height as the center of gravity <NUM> of the head. This configuration allows the sub chamber <NUM> to catch the head <NUM> of the passenger P1 in a balanced manner, in addition to efficiently restraining the head <NUM>. Note that in the case of the present embodiment, the center of gravity <NUM> of the head can be calculated as the geometric center or the mass center of the head of the abovementioned dummy doll WorldSID 50th male. While the geometric center and the mass center are slightly different depending on the distribution of the mass, they are generally at the same position.

As described above with reference to <FIG>, in the present embodiment, the sub chamber <NUM> is expanded early on by directly feeding the gas to the sub chamber <NUM> through the inner tube <NUM>. Consequently, at the same time as or slightly before the main chamber <NUM> contacts the vicinity of the shoulder <NUM> of the passenger P1, the sub chamber <NUM> also contacts the head <NUM> of the passenger P1. This allows the passenger P1 to be restrained at a position which suppresses the displacement of the head <NUM> to the shoulder <NUM>, in addition to reducing the burden on the passenger P1. In this manner, this side airbag apparatus <NUM> can reduce the burden on the passenger P1 when the passenger P1 is restrained in a simple configuration.

Moreover, in this side airbag apparatus <NUM>, the gas is distributed by the inner tube <NUM> (see <FIG>, etc.), making it possible to prevent the expansion pressure of the cushion <NUM> from locally concentrating in the initial stage of expansion and deployment. Consequently, for example, when the passenger P1 contacts the cushion <NUM> in the state in which the passenger P1 is in a position other than the normal seating position, etc., the passenger P1 does not need to touch a region having a high expansion pressure, making it possible to contribute to improving the safety of the cushion <NUM>.

The sub chamber <NUM> has a smaller capacity than the main chamber <NUM> and finishes being expanded and deployed earlier than the main chamber <NUM>. In order to quicken the expansion and deployment of the sub chamber <NUM>, as mentioned above, it is effective to set the inner diameter of the sub vent <NUM> so as to be larger than the inner diameter of the main vent <NUM>. When the sub chamber <NUM> finishes being expanded early on, at the same time as or slightly before the main chamber <NUM> touches the shoulder <NUM> of the passenger P1, the sub chamber <NUM> touches the head <NUM> of the passenger P1, making it possible to restrain the passenger P1 at a position suppressing the displacement of the head <NUM>.

<FIG> is a view obtained by viewing the passenger P1 and the cushion <NUM> in <FIG> from above. As mentioned above, the surface <NUM> of the sub chamber <NUM> on the passenger side is continuously gently curved from the front end 134a and the rear end 134b to the central part 134c such that the central part 134c thereof is recessed on the main chamber <NUM> side. The sub chamber <NUM> having this configuration can be expanded to a shape which tends to catch this head <NUM> along the shape of the head <NUM> of the passenger P1 so as to efficiently restrain the head <NUM> of the passenger P1.

In the present embodiment, the maximum protruding amount W1 of the sub chamber <NUM> from the main chamber <NUM> to the passenger side in the width direction of the vehicle is set so as to be smaller than the distance W2 between the main chamber <NUM> and the head <NUM> of the passenger P1 in the normal seating position of the seat <NUM> (the distance W2 > the protruding amount W1). This configuration prevents the sub chamber <NUM> from pushing back the head <NUM> of the passenger P1, in addition to suppressing the burden on the passenger P1.

As described with reference to <FIG>, in this side airbag apparatus <NUM>, the cushion <NUM> having the abovementioned configuration is provided on the side part of the seat <NUM> on the central side of the vehicle (which is the far side). If a side collision occurs to the vehicle, inertia allows the passenger P1 to move to the side (far side) opposite the impact position, that is, to the central side of the vehicle. At this time, because no structure is typically present on the central side of the vehicle, the passenger P1 may move more greatly than moving towards the impact position side (near side). When an attempt is made to restrain such a passenger P1 from the side with a flat cushion, the head <NUM> may fall, placing a burden on the cervical vertebra. In this regard, this cushion <NUM> restrains the head <NUM> (without falling of the head <NUM>) by utilizing the sub chamber <NUM> which is expanded early on, allowing the burden on the passenger P1 to be suppressed in order to restrain the head <NUM>.

Hereinafter, modified examples of each of the abovementioned components will be described. In <FIG>, the same components as those previously described are labeled with the same symbols, so the description of the previously described components is thereby omitted. Moreover, in the following description, the same names as the components described above shall have the same functions unless otherwise indicated even when labeled with different symbols.

<FIG> is a view illustrating Modified Examples <NUM> and <NUM> (cushions <NUM>, <NUM>) of the cushion <NUM> in <FIG>. <FIG> illustrates a cross sectional view of the cushion <NUM> of Modified Example <NUM> corresponding to the cushion <NUM> in <FIG>. The cushion <NUM> is configured differently from the cushion <NUM> in <FIG> in that a check valve <NUM> is provided on the sub vent <NUM>.

The check valve <NUM> cylindrically extends from the sub vent <NUM> into the sub chamber <NUM>, with the tip side serving as a free end. <FIG> is an enlarged view of the check valve <NUM> in <FIG>. In the check valve <NUM>, stitching 206a, 206b is provided at the edges of a root part <NUM>, wherein the root part <NUM> has higher rigidity than the tip part <NUM>.

Regarding the check valve <NUM>, when the load from the passenger P1 is applied to the sub chamber <NUM> (see <FIG>), the flow of gas passing through the check valve <NUM> allows the tip part <NUM> to be absorbed inside a root part <NUM>, wherein the inside of the root part <NUM> is blocked by the tip part <NUM>. This can prevent the gas from flowing out from the sub chamber <NUM> to the inner tube <NUM>, thereby allowing the expansion pressure of the sub chamber <NUM> to be maintained for longer periods of time.

<FIG> illustrates a cross sectional view of the cushion <NUM> of Modified Example <NUM> corresponding to the cushion <NUM> in <FIG>. The cushion <NUM> is configured differently from each of the abovementioned cushions in that the check valve <NUM> is provided at a position different from the sub vent <NUM>.

A vent hole <NUM> which connects the sub chamber <NUM> and the main chamber <NUM> is provided in the cushion <NUM>, wherein the check valve <NUM> is provided on the main chamber <NUM> side of this vent hole <NUM>. When the sub chamber <NUM> finishes being expanded or the load of the passenger P1 (see <FIG>) is applied on the sub chamber <NUM>, etc., the vent hole <NUM> can release the gas from the sub chamber <NUM> to the main chamber <NUM>. The provision of the vent hole <NUM> can appropriately suppress the expansion pressure of the sub chamber <NUM>, in addition to preventing damage to the sub chamber <NUM>. In contrast, the check valve <NUM> tends not to allow the gas to enter from the main chamber <NUM> to the sub chamber <NUM>.

As mentioned above, regarding the cushion <NUM>, the check valve <NUM> can prevent the gas from flowing backward to the sub chamber <NUM> (if the load of the passenger P1 is applied to the main chamber <NUM>, etc.), maintaining the expansion pressure of the main chamber <NUM>, in addition to preventing the irregular expansion of the sub chamber <NUM>. Note that also in the cushion <NUM>, as in the cushion <NUM> in <FIG>, the sub vent <NUM> may have a check valve structure.

Therefore, it is obvious that a person with ordinary skill in the art can conceive of various changed examples or modified examples within the scope described in the scope of the claims, which is understood to naturally belong to the technical scope of the present invention.

The present invention can be used in a side airbag apparatus mounted in a vehicle.

Claim 1:
A side airbag apparatus (<NUM>,<NUM>,<NUM>), comprising: an airbag cushion (<NUM>) which is expanded and deployed to the side of a passenger (P1) seated in a seat of a vehicle; and an inflator (<NUM>) supplying gas to this airbag cushion (<NUM>);
wherein the airbag cushion (<NUM>) comprises:
a main chamber (<NUM>) which is expanded and deployed within at least the range from the shoulder to the head of the passenger (P1) and
a sub chamber (<NUM>) which is expanded and deployed so as to protrude from the position above the shoulder of the passenger (P1) to the passenger side in the main chamber (<NUM>);
an inner tube (<NUM>) which cylindrically extends inside the main chamber (<NUM>) and contains the inflator (<NUM>), with a portion of the inner tube (<NUM>) adjacent to the sub chamber (<NUM>);
a main vent (<NUM>) which is opened at a predetermined position of the inner tube (<NUM>) so as to release gas from this inner tube (<NUM>) into the main chamber (<NUM>); and
a sub vent (<NUM>) which penetrates through the inner tube (<NUM>) and a panel of the main chamber (<NUM>) so as to release gas from this inner tube (<NUM>) into the sub chamber (<NUM>),
characterized in that
regarding the surface of the sub chamber (<NUM>) on the passenger side, the central part (134c) is recessed on the main chamber (<NUM>) in the horizontal cross section of the airbag cushion (<NUM>) as viewed from above, and
the recessed surface of the sub chamber (<NUM>) on the passenger side is continuously curved from both ends of this surface in the anteroposterior direction of the vehicle to the central part (134c).