Patent Description:
The provision of a vehicle with one or more airbags in order to protect the occupants thereof in the event of a vehicle accident is well known. These airbags include, for example, various forms such as: a so-called driver airbag which is deployed from near the center of the steering wheel so as to protect the driver; a curtain airbag which is deployed downward on the inner side of the window of an automobile so as to protect occupants during collisions in the transverse direction of a vehicle, as well as when overturning and during rollover accidents; and a side airbag which is deployed between the occupant and the side panel so as to protect the occupant upon impact in the transverse direction of a vehicle. The present invention relates to a side airbag device provided in a vehicle seat.

For side airbag devices, there is a strong demand for a more compact device due to major installation area limitations. Moreover, there is a demand for appropriate passenger protection performance due to improved deployment speed and stabilization of the deployed shape.

In recent years, side airbag devices have been proposed that combine a plurality of chambers to form an airbag. For example, there are systems with a pre-chamber, with a relatively small capacity inside the main chamber (on the passenger side), as described in Patent Document <NUM>. However, during airbag deployment, the front end portion of the pre-chamber could interfere with the occupant, preventing proper deployment. An airbag device according to the preamble of claim <NUM> is disclosed in Patent Document <NUM>.

In light of the conditions described above, a purpose of the present invention is to provide a side airbag device that can optimize (stabilize) deployment behavior of the pre-chamber in side airbags having a main chamber and a pre-chamber, and a method for manufacturing airbags used therein.

The following describes means for solving the problem described above and the effect thereof. In the present invention, when an occupant is seated in a seat in a normal posture, the direction the occupant faces is referred to as the "front," the opposite direction is referred to as the "rear," and the direction indicating the coordinate axis is referred to as the "front-rear direction. " Moreover, when the passenger is seated in the seat in a regular posture, the right of the passenger is referred to as the "right direction," the left of the passenger is referred to as the "left direction," and the direction indicating the coordinate axis is referred to as the "left and right direction. " Similarly, when the passenger is seated in the seat in a regular posture, the head direction of the passenger is referred to as "up," the waist direction of the passenger is referred to as "down," and the direction indicating the coordinate axis is referred to as the "vertical direction.

In order to achieve the purpose as described above the present invention is a side airbag device stowed in the seatback of a vehicle seat, comprising:.

The airbag includes a main chamber that deploys toward the front of the seatback, and a pre-chamber that houses the inflator inside and is connected to the occupant side of the main chamber. Furthermore, an integral joint without gaps is formed by sewing between at least the front edge part of the pre-chamber and the main chamber.

Here, the "integral joint without gaps" formed by sewing means that the pre-chamber is continuously sewn along the front edge part against the surface of the main chamber, so that no part of the pre-chamber (tip side) is separated from the main chamber and becomes unstable. Alternatively, it can be said that the expandable area of the pre-chamber does not protrude forward from the junction thereof with the main chamber.

With the present invention, an integral joint without a gap is formed between at least the front edge part of the pre-chamber and the main chamber by sewing, which prevents the edge (one part) of the pre-chamber from wobbling and catching on the occupant, stabilizing the pre-chamber's deployment behavior and contributing to improved occupant restraint performance.

The main chamber includes an inner main panel and an outer main panel, and is formed by overlapping these two panels and sewing the outer edge parts together. The pre-chamber is formed by sewing one pre-chamber panel to the inner main panel.

The inner main panel is configured with a first inner vent so that expansion gas can flow from the pre-chamber to the main chamber via said first inner vent.

A baffle panel is be provided with an inner edge part connected to the inner surface of the inner main panel and an outer edge part connected to the inner surface of the outer main panel. The baffle panel partitions said main chamber into a forward main chamber and a rear main chamber.

The baffle panel is configured with a second inner vent to allow expansion gas to flow from the rear main chamber to the forward main chamber via said second inner vent.

The inner edge part of the baffle panel can be constructed to be arranged along the front edge part of the pre-chamber. This structure simplifies the structure itself and simplifies the manufacturing process.

The integral joint is made of at least three overlapping layers: the inner main panel, the front edge part of the pre-chamber panel, and the inner edge part of the baffle panel.

A reinforcement cloth is provided between the front edge part of the pre-chamber panel and the outer surface of the inner main panel, and the integral joint is made of four overlapping layers that include said reinforcement cloth.

The front edge part of the pre-chamber can be provided so that the front edge part of the pre-chamber draws a curved line when viewed from the side of the vehicle seat in the width direction. When viewed from the side of the vehicle seat in the width direction, the front edge part of the pre-chamber and the inner edge part of the baffle panel can be overlapped to form a curved line. The manufacturing method of the airbag according to the present invention according to claim <NUM> includes:.

In the present invention, after the front edge part of the pre-chamber panel is temporarily sewn to the inner main panel, the front edge part of the pre-chamber panel, the inner main panel, and the inner edge part of the baffle panel are sewn at the same time, thereby simplifying the manufacturing process. In particular, this can easily accommodate cases where the front edge part of the pre-chamber is formed as a curved line.

The side airbags of the present invention can be applied to the type that deploys on the door side (outside) of the seat as well as the type that deploys on the center side of the vehicle of the seat. A side airbag of a type which is deployed on the vehicle center side of the seat, for example, is referred to as a far side airbag, front center airbag, rear center airbag, and the like.

A vehicle seat according to an embodiment of the present invention will be described with reference to accompanying drawings. Note that "front" indicated in the drawings indicates the front side (in the traveling direction) of a vehicle, "rear" indicates the rear of the vehicle (side opposite the traveling direction), "inside" indicates the inner side in the vehicle width direction (occupant side), and "outside" indicates the outer side in the vehicle width direction (door panel side).

<FIG> is a perspective view illustrating mainly the external shape of a vehicle seat to which the side airbag device <NUM> according to the present invention can be applied, with illustration of the side airbag device (<NUM>) omitted. <FIG> is a perspective view illustrating an internal structure (seat frame) functioning as a framework of the vehicle seat illustrated in <FIG>, with illustration of the side airbag device (<NUM>) omitted here as well. <FIG> is a schematic side surface view of the vehicle seat mounted with the side airbag device <NUM> according to the present invention, for example, illustrating a condition where the airbag device <NUM> is stowed on a side surface (near side) near a door as observed from the outside in the vehicle width direction.

As illustrated in <FIG> and <FIG>, from the viewpoint of components, a vehicle seat to which a side airbag device <NUM> according to this embodiment can be applied is composed of a seat cushion <NUM>, or a portion for an occupant to sit on, a seatback <NUM> forming a backrest, and a headrest <NUM> connected to the upper end of the seatback <NUM>.

A seatback frame 1f that forms that framework of the seat is provided in the inner portion of the seatback <NUM>, a pad made of urethane foam or the like is provided on the surface and periphery thereof, and a surface skin (not illustrated) is provided. As for the seat cushion <NUM>, similar to the seatback <NUM>, a pad made of urethane foam or the like is provided on the upper surface and periphery of the seating frame 2f, and a surface skin (not illustrated) is provided. The seating frame 2f and the seatback frame 1f are connected via a reclining mechanism <NUM>.

As illustrated in <FIG>, the seat back frame 1f is configured into a frame shape by side frames <NUM> disposed laterally spaced apart and extending in the vertical direction, an upper frame connecting the upper ends of the side frames <NUM>, and a lower frame connecting the lower ends thereof. The headrest <NUM> is configured by providing a cushioned component outside a headrest frame.

<FIG> is a schematic diagram (side view) that illustrates the airbag <NUM> (<NUM>, <NUM>) in a deployed state. As illustrated in <FIG>, the airbag <NUM> (<NUM>, <NUM>) is provided with a main chamber <NUM> that deploys toward the front of the side support part <NUM>, and a pre-chamber <NUM> that deploys to the inside of the main chamber <NUM> in the width direction (occupant side) of the vehicle.

<FIG> is a schematic view illustrating the deployed state of the airbag <NUM>, corresponding to the cross section along line A1-A1 in <FIG>. <FIG> are plan views illustrating the main panels configuring the airbag <NUM> (<NUM>, <NUM>).

The side airbag device <NUM> according to the present invention is arranged on the occupant side of the side frame <NUM>, and is provided with an inflator <NUM> that generates expansion gas, and the airbag <NUM> (<NUM>, <NUM>) that expands based on expansion gas to protect an occupant seated in the vehicle seat. The airbag <NUM> includes a main chamber <NUM> that deploys toward the front of the seatback <NUM>, and a pre-chamber <NUM> that houses the inflator <NUM> inside and is connected to the occupant side of the main chamber <NUM>. As will be described in more detail below, between the front edge part 34b of pre-chamber <NUM> and the main chamber <NUM> (32a), an integral joint with no gaps is formed by sewing 56a.

For example, a cylinder-type inflator having a cylindrical shape may be used as the inflator <NUM>. Stud bolts <NUM> protrude from the outer circumference of the inflator <NUM> toward the inside in the vehicle width direction. These stud bolts <NUM> are attached (fastened and secured) to the side frame <NUM> using nuts. The inflator <NUM> has a plurality of circumferentially aligned gas jets (not shown), and gas is radially emitted from these gas jets. If necessary, a diffuser or other device to control gas flow can be provided around the inflator <NUM>.

An airbag control ECU (not shown) mounted on the vehicle is electrically connected to this inflator <NUM>. A satellite sensor (not shown) for detecting side collisions is electrically connected to this airbag control ECU. The inflator <NUM> can be configured to operate when the airbag control ECU detects a side collision based on a signal from this satellite sensor.

As illustrated in <FIG> and <FIG>, the main chamber <NUM> includes the inner main panel 32a located on the passenger side and an outer main panel 32b located on the opposite side from the occupant. Furthermore, these two panels 32a and 32b are stacked and the outer edge parts are sewn together to form the main chamber <NUM>.

As illustrated in <FIG> and <FIG>, the pre-chamber <NUM> is formed by sewing a single pre-chamber panel 34a to the inner main panel 32a. The pre-chamber panel 34a is formed with a curvature with protruding parts 76a and 76b that are the upper and lower portions of the front edge part 34b protruding forward.

As illustrated in <FIG> and <FIG>, the inner main panel 32a has a first inner vent V1 that is formed in three places, and the expansion gas inside the pre-chamber <NUM> is supplied via the first inner vent V1 into the main chamber <NUM>. Reinforcement sewing <NUM> is formed around the inner vents V1.

Two external vents V3 are formed near the front edge part of the inner main panel 32a to release gas to the outside. Also, an opening <NUM> for inserting the inflator <NUM> and an opening <NUM> to allow the stud bolts <NUM> of the inflator <NUM> to pass through are formed near the rear edge part of the outer main panel 32b.

As illustrated in <FIG> and <FIG>, the inner portion of the main chamber <NUM> has an inner edge part 38a connected to the inner surface of the inner main panel 32a, and a baffle panel <NUM> with an outer edge part 38b connected to the inner surface of the outer main panel 32b. The baffle panel <NUM> allows the main chamber <NUM> to be divided into a forward main chamber 32f and a rear main chamber 32r.

The baffle panel <NUM> is formed with two second inner vents V2, where expansion gas flows from the rear main chamber 32r via the second inner vents V2 into the forward main chamber 32f. Reinforcement sewing <NUM> is formed around the inner vents V2.

Note that the inner edge part 38a of the baffle panel <NUM> is connected along the front edge part 34b of the pre-chamber <NUM>. This structure simplifies the structure itself and simplifies the manufacturing process.

As illustrated in <FIG>, the integral joint 56a is a structure consisting of three overlapping layers, being the outer surface (external surface) of the inner main panel 32a, the front edge part 34b of the pre-chamber panel 34a, and the inner edge part 38a of the baffle panel <NUM>. More accurately, a reinforcement cloth <NUM> is provided sandwiched between the front edge part 34b of the pre-chamber panel 34a and the outer surface of the inner main panel 32a, making the integral joint 56a a structure consisting of four layers, including the reinforcement cloth <NUM>. The reinforcement cloth <NUM> is arranged along the front edge part 34b of the pre-chamber panel 34a, and then sewed.

Next, a brief description of the sewn areas of each panel is given with reference to <FIG>. Code <NUM> is the sewing that connects the pre-chamber panel 34a to the reinforcement cloth <NUM>. Code <NUM> is the temporarily sewing together of the front edge part 34b of the pre-chamber panel 34a, the reinforcement cloth <NUM>, and the inner main panel 32a. Code <NUM> is sewing connecting the inner main panel 32a and the outer main panel 32b, forming a non-expanding region <NUM> (see <FIG>) for inserting the inflator <NUM> into the pre-chamber <NUM>. Code <NUM> is sewing that connects the outer circumference of the airbag <NUM>.

<FIG>, <FIG> are plan views of the manufacturing (sewing) steps of the airbag <NUM> according to the present invention. First, as illustrated in <FIG>, in the inner main panel 32a, sewing (<NUM>) is performed around the three inner vents V1, then sewing 80a and 80b is performed around the two external vents V3.

To begin with, it is extremely difficult to sew the curved edge part of the pre-chamber panel 34a and the curved edge part of the baffle panel <NUM> at the same time while sandwiching the flat-shaped inner main panel 32a. Therefore, in the past, the pre-chamber and main chamber were each sewn separately back-to-back, and then the pre-chamber and main chamber were joined so that the edge parts of the pre-chamber and the baffle panel do not overlap.

Therefore, in the present invention, following the steps in <FIG>, as illustrated in <FIG> and <FIG>, the pre-chamber panel 34a is overlaid on the surface of the inner main panel 32a and temporary sewing <NUM> is performed along the front edge part 34b of the pre-chamber panel 34a. Herein, the reinforcement cloth <NUM> is sewn at the same time.

Next, as illustrated in <FIG> and <FIG>, the front edge part 34b of the pre-chamber panel 34a, reinforcement cloth <NUM>, inner main panel 32a, and the inner edge part 38a of the baffle panel <NUM> are sewn at the same time, forming an integral connecting part 56a. At the same time, the outer edge part 38b of the baffle panel <NUM> and the outer main panel 32b are sewn (56b) together.

Next, as illustrated in <FIG> and <FIG>, sewing <NUM> is performed in the vertical direction on the inner main panel 32a and outer main panel 32b in front of the openings <NUM> and <NUM> of the inflator <NUM>, forming the non-expanding region <NUM>. In order to clearly illustrate the sewing locations, <FIG> illustrates the state illustrated in <FIG> inverted front to back.

Next, as illustrated in <FIG> and <FIG>, reinforcement sewing <NUM> and <NUM> is performed around the openings <NUM> and <NUM> of the inflator <NUM>. Thereafter, sewing <NUM> is performed around the entire perimeter of the inner main panel 32a and the outer main panel 32b.

In the present invention, an integral joint without a gap is formed between the front edge part 34b of the pre-chamber <NUM> and the main chamber <NUM> (32a) by sewing 56a, which prevents the edge part (one part) of the pre-chamber <NUM> from wobbling and catching the occupant when the airbag <NUM> is deployed, stabilizing deployment behavior of the pre-chamber <NUM>, and contributing to improved occupant restraining performance.

In addition, after the front edge part 34b of the pre-chamber panel 34a is temporarily sewn (<NUM>) to the inner main panel 32a, the front edge part 34b of the pre-chamber panel 34a, the inner main panel 32a, and the inner edge part 38a of the baffle panel <NUM> are sewn at the same time, thereby simplifying the manufacturing process. In particular, this can easily accommodate cases where the front edge part 34b of the pre-chamber <NUM> is formed as a curved line.

Claim 1:
A side airbag device (<NUM>) stowed in a seatback (<NUM>) of a vehicle seat, comprising:
an inflator (<NUM>) arranged on the occupant side of a side frame (<NUM>) positioned on a side part (<NUM>) of the seatback (<NUM>), which generates expansion gas; and
an airbag (<NUM>) that expands due to said expansion gas and protects the occupant seated in the vehicle seat, wherein
the airbag (<NUM>) includes a main chamber (<NUM>) that deploys forward of the seatback (<NUM>), and a pre-chamber (<NUM>) stowing the inflator (<NUM>) in an inner portion thereof and which is connected to the occupant side of the main chamber (<NUM>), and
an integral joint (56a) with no gaps present is formed between at least a front edge part (34b) of the pre-chamber (<NUM>) and the main chamber (<NUM>), wherein the main chamber (<NUM>) includes an inner main panel (32a) and an outer main panel (32b), is formed by overlapping said two panels (32a,32b) and sewing the outer edges thereof, and where the pre-chamber (<NUM>) is formed by sewing one pre-chamber panel (34a) to the inner main panel (32a),
wherein a first inner vent (V1) is formed on the inner main panel (32a) so that expansion gas can flow from the pre-chamber (<NUM>) to the main chamber (<NUM>) via said first inner vent (V1),
wherein a baffle panel (<NUM>) having an inner edge part (38a) connected to the inner surface of the inner main panel (32a) and an outer edge part (38b) connected to the inner surface of the outer main panel (32b) is provided, and the baffle panel (<NUM>) separates the main chamber (<NUM>) into a forward main chamber (32f) and a rear main chamber (32r),
wherein a second inner vent (V2) is formed on the baffle panel (<NUM>) so that expansion gas can flow from the rear main chamber (32r) to the forward main chamber (32f) via said second inner vent (V2), characterized in that
- the integral joint (56a) is made of four overlapping layers, being the inner main panel (32a), the front edge part (34b) of the pre-chamber panel (34a), and the inner edge part (38a) of the baffle panel (<NUM>), and a reinforcement cloth (<NUM>) provided between the front edge part (34b) of the pre-chamber panel (34a) and the outer surface of the inner main panel (32a).