Airbag devices and occupant protection devices

Abstract

To provide an airbag device capable of appropriately restraining an occupant even when a vehicle has had offset collision or oblique collision, and the occupant has moved to a seat oblique front side; and to provide an occupant protection device comprising the same.SOLUTION: An airbag device 30 comprises an airbag 32 supplied with gas generated in an inflator upon vehicle collision to be inflated and deployed from a rear side of a vehicle seat 12 to a front side through an upper side. The airbag 32 in an inflated and deployed state comprises: a pair of front-rear chambers 34 extending in a front-rear direction through left and right sides of a head H of an occupant D; and an airbag body 40 that is in communication with the pair of front-rear chambers 34, is disposed at a front side of the occupant D between the pair of front-rear chambers 34, and is compression-deformed while being supported by the pair of front-rear chambers 34 when the occupant D is restrained. The airbag device 30 inhibits at least the head H of the occupant D from entering gaps between the front-rear chambers 34 and the airbag body 40 during a latter half of restraint of the occupant D.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an airbag device and an occupant protection device equipped with an airbag device. [Background technology]

[0002] The airbag device disclosed in Patent Document 1 listed below includes an inflator that generates high-pressure gas when an impact is applied, and a bag body that receives the gas from the inflator and inflates and deploys from a seatback of a vehicle seat. The bag body includes a torso support portion that deploys on the opposite side of the seatback to sandwich the torso of an occupant seated in the vehicle seat, and a pair of head support portions that deploy on both sides of the seat width direction to sandwich the occupant's head and are connected to the torso support portion. In addition, the bag body has a relief portion that, in a deployed state, penetrates vertically between the pair of head support portions to avoid the occupant's head. Furthermore, this airbag device includes a connecting member that connects the deployed torso support portion to the vehicle seat or the vehicle body.

[0003] The airbag device disclosed in Patent Document 2 below includes an inflator and an airbag that deploys using gas supplied from the inflator. The airbag has a rear inflatable section that deploys on the backside of the seat, a pair of side inflatable sections that extend forward from both widthwise sides of the rear inflatable section, and a pair of front inflatable sections that extend toward the center from the pair of side inflatable sections and are connected to each other at the center to cover the front of the occupant. This airbag has gas flow paths formed in the order of the rear inflatable section, the side inflatable sections, and the front inflatable sections. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2019-018593 [Patent Document 2] Japanese Patent Application Publication No. 2019-218013 Summary of the Invention [Problem to be solved by the invention]

[0005] The airbag body (bag body, airbag) of the airbag device described above restrains the upper body of the occupant mainly by a tensile load relatively directed toward the rear side of the seat. Therefore, when the vehicle is involved in an offset collision or an oblique collision and the occupant moves diagonally forward of the seat, the effect of the tensile load is not sufficiently and appropriately obtained, and there is a risk that the occupant's head, in particular, may slip through the airbag body.

[0006] Therefore, an object of the present invention is to provide an airbag device that can properly restrain an occupant even when the vehicle is involved in an offset collision or an oblique collision and the occupant moves diagonally forward from the seat, and an occupant protection device equipped with the airbag device. [Means for solving the problem]

[0007] In order to achieve the above object, the airbag device of a first aspect of the present invention comprises an inflator that generates gas in the event of a vehicle collision, and an airbag that is supplied with the gas generated by the inflator and inflates and deploys from the rear side of the vehicle seat, passing above the seat and toward the front side of the seat, wherein the airbag in an inflated and deployed state has a pair of front and rear chambers that extend in the front-to-rear direction of the seat, passing on both sides of the head of an occupant seated in the vehicle seat, and an airbag body that is connected to the pair of front and rear chambers, is positioned on the front side of the occupant's seat between the pair of front and rear chambers, and is compressed and deformed while supported by the pair of front and rear chambers when the occupant is restrained, and is configured to prevent at least the occupant's head from entering the gap between the front and rear chambers and the airbag body during the latter half of the restraint of the occupant.

[0008] According to the first aspect of the invention, when a vehicle collision occurs, gas generated by an inflator is supplied to the airbag, causing the airbag to inflate and deploy from the rear side of the vehicle seat, passing above the seat, and toward the front side of the seat. The inflated and deployed airbag has a pair of front and rear chambers extending in the front-to-rear direction of the seat, passing both left and right sides of the head of an occupant seated in the vehicle seat, and an airbag body that is connected to the pair of front and rear chambers, is positioned between the pair of front and rear chambers, and is compressed and deformed while being supported by the pair of front and rear chambers when the occupant is restrained.

[0009] The airbag is designed to prevent at least the occupant's head from entering the gap between the front and rear chambers and the airbag body during the latter half of the occupant's restraint period. Therefore, even if the vehicle experiences an offset or diagonal collision and the occupant moves diagonally forward from the seat, the occupant is properly restrained. Note that "during a collision" as used here also includes a situation in which the inevitability of a collision is predicted (foreseen).

[0010] Furthermore, an airbag device of a second aspect according to the present invention is the airbag device of the first aspect, wherein the airbag has a pair of upper tethers (left and right) connecting the front and rear chambers to the upper part of the airbag body, and a pair of lower tethers (left and right) connecting the front and rear chambers to the lower part of the airbag body, and at least the lower tethers are surface tethers that are approximately triangular in shape and have a symmetrical shape that covers the gap.

[0011] According to a second aspect of the invention, the airbag has a pair of upper tethers (left and right) connecting the front and rear chambers to the upper part of the airbag body, and a pair of lower tethers (left and right) connecting the front and rear chambers to the lower part of the airbag body. At least the lower tethers are surface tethers with a generally triangular shape that is symmetrical and covers the gap. Therefore, even when the vehicle is in an offset collision or an oblique collision and the occupant moves diagonally forward of the seat, the occupant is appropriately restrained by the lower tethers.

[0012] Furthermore, an airbag device of a third aspect according to the present invention is the airbag device of the first aspect, wherein the airbag has a pair of left and right lower inflation portions that fill the gap between the front and rear chambers and the lower part of the airbag body.

[0013] According to the third aspect of the invention, the airbag has a pair of left and right lower inflatable portions that fill the gap between the front and rear chambers and the lower part of the airbag body. Therefore, even when the vehicle is involved in an offset collision or an oblique collision and the occupant moves diagonally forward of the seat, the occupant is appropriately restrained by the lower inflatable portions.

[0014] Furthermore, an airbag device of a fourth aspect according to the present invention is the airbag device of the third aspect, wherein the airbag has a pair of upper inflation portions on the left and right that fill the gap between the front and rear chambers and the upper part of the airbag body.

[0015] According to the fourth aspect of the invention, the airbag has a pair of left and right upper inflatable portions that fill the gap between the front and rear chambers and the upper part of the airbag body. Therefore, even when the vehicle is involved in an offset collision or an oblique collision and the occupant moves diagonally forward of the seat, the occupant is appropriately restrained by the upper inflatable portions.

[0016] In addition, the airbag device of a fifth aspect according to the present invention is the airbag device of the third aspect, wherein the lower inflation portion is configured so that the gas is supplied from the front and rear chambers through a lower communication hole, and the opening area of the lower communication hole is set smaller than the opening area of the communication hole for supplying the gas from the front and rear chambers to the airbag body.

[0017] According to the fifth aspect of the invention, the lower inflation portion is configured to receive gas from the front and rear chambers via the lower communication hole, and the opening area of the lower communication hole is set smaller than the opening area of the communication hole for supplying gas from the front and rear chambers to the airbag body. Therefore, even with a configuration that includes a lower inflation portion, there is no delay in deployment of the airbag body.

[0018] In addition, a sixth aspect of the airbag device according to the present invention is the airbag device of the fourth aspect, wherein the upper inflation portion is configured so that the gas is supplied from the front and rear chambers through an upper communication hole, and the opening area of the upper communication hole is set smaller than the opening area of the communication hole for supplying the gas from the front and rear chambers to the airbag body.

[0019] According to the sixth aspect of the invention, the upper inflation portion is configured to receive gas from the front and rear chambers through the upper communication holes, and the opening area of the upper communication holes is set smaller than the opening area of the communication holes for supplying gas from the front and rear chambers to the airbag body. Therefore, even with a configuration in which an upper inflation portion is provided, there is no delay in deployment of the airbag body.

[0020] Furthermore, the airbag device of a seventh aspect according to the present invention is the airbag device of the first aspect, in which convex bulging portions that fill the gap with the airbag body are formed on the inner surfaces of the front and rear chambers that face each other in the seat width direction.

[0021] According to the seventh aspect of the invention, convex bulges that fill the gap between the airbag body and the inner surfaces of the front and rear chambers facing each other in the seat width direction are formed. Therefore, even when the vehicle is involved in an offset collision or an oblique collision and the occupant moves diagonally forward of the seat, the occupant is appropriately restrained by the convex bulges.

[0022] An airbag device according to an eighth aspect of the present invention is the airbag device according to the first aspect, wherein the airbag has a pair of guide cloths that cover the gap, one end of which is sewn to the inner surfaces of the front and rear chambers that face each other in the seat width direction, and the other end of which is sewn to the airbag body.

[0023] According to an eighth aspect of the invention, the airbag has a pair of guide cloths, one end of which is sewn to the inner surfaces of the front and rear chambers facing each other in the seat width direction, and the other end of which is sewn to the airbag body, covering the gap. Therefore, even when the vehicle is in an offset collision or an oblique collision and the occupant moves diagonally forward of the seat, the occupant is appropriately restrained by the guide cloths.

[0024] An airbag device according to a ninth aspect of the present invention is the airbag device of the first aspect, wherein a recess is formed in a plan view in a central portion in the seat width direction on a wall surface of the airbag body on the seat rear side.

[0025] According to the ninth aspect of the invention, a recess is formed in a plan view in the center of the seat width direction on the wall surface of the airbag body on the seat rear side. Therefore, even when the vehicle is involved in an offset collision or an oblique collision and the occupant moves diagonally forward of the seat, the occupant is held in the airbag body without falling out of the recess. In other words, the occupant is appropriately restrained by the airbag body.

[0026] In addition, an occupant protection device according to a tenth aspect of the present invention includes a vehicle seat on which an occupant sits, and an airbag device according to any one of the first to ninth aspects mounted on a rearward portion of the vehicle seat.

[0027] According to the tenth aspect of the invention, an airbag device is mounted on a rear portion of a vehicle seat in which an occupant sits. This airbag device is one of the first to ninth aspects, and therefore provides the same effects as any of the first to ninth aspects. [Effects of the Invention]

[0028] As described above, according to the present invention, even when the vehicle is involved in an offset collision or an oblique collision and the occupant moves diagonally forward from the seat, the occupant can be appropriately restrained. [Brief explanation of the drawings]

[0029] [Figure 1] 1 is a schematic perspective view showing a state in which an airbag in an airbag device of an occupant protection device relating to a first embodiment is inflated and deployed. [Figure 2] 1 is a schematic side view showing a state in which an airbag of an airbag device according to a first embodiment is inflated and deployed toward an occupant. [Figure 3] 2 is a development view of front and rear chambers that constitute the airbag of the airbag device according to the first embodiment. FIG. [Figure 4] 1 is a development view of an airbag main body that constitutes an airbag of an airbag device according to a first embodiment. [Figure 5] 1 is a schematic side view showing a state in which an airbag of the airbag device according to the first embodiment is inflating and deploying while passing through a gap between an occupant's head and the ceiling of a vehicle compartment. FIG. [Figure 6] 1 is a schematic side view showing a state in which an airbag of the airbag device according to the first embodiment is inflating and deploying and passing over the shoulder of an occupant. FIG. [Figure 7] 1 is a schematic side view showing a state in which an airbag of the airbag device according to the first embodiment is inflated and deployed and is about to be positioned in front of an occupant. FIG. [Figure 8] FIG. 10 is a schematic side view showing a state in which an airbag of an airbag device according to a second embodiment is inflated and deployed toward an occupant. [Figure 9] FIG. 10 is a development view of front and rear chambers that constitute an airbag of an airbag device according to a second embodiment. [Figure 10] FIG. 10 is a schematic plan view showing a state in which an airbag of an airbag device according to a third embodiment is inflated and deployed toward an occupant. [Figure 11] 10(A) to 10(C) are explanatory diagrams showing, in plan view, the process up to restraining an occupant with an airbag of an airbag device according to a third embodiment. [Figure 12] FIG. 10 is a schematic plan view showing a state in which an airbag of an airbag device according to a fourth embodiment is inflated and deployed toward an occupant. [Figure 13]10(A) to 10(C) are explanatory diagrams showing, in plan view, the process up to restraining an occupant with an airbag of an airbag device according to a fourth embodiment. [Figure 14] FIG. 11 is a schematic plan view showing a state in which an airbag of an airbag device according to a fifth embodiment is inflated and deployed toward an occupant. [Figure 15] 10(A) to 10(C) are explanatory diagrams showing, in plan view, the process up to restraining an occupant with an airbag of an airbag device according to a fifth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0030] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. For convenience of explanation, the arrow UP shown in each drawing indicates the upward direction of the vehicle and the vehicle seat, the arrow FR indicates the forward direction of the vehicle and the vehicle seat, the arrow RH indicates the rightward direction of the vehicle and the vehicle seat, and the arrow LH indicates the leftward direction of the vehicle and the vehicle seat. Therefore, in the following description, unless otherwise specified, when the directions of up / down, front / rear, and left / right are mentioned, they refer to up / down, front / rear, left / right, and right / left of the vehicle and the vehicle seat. Furthermore, the left / right direction is synonymous with the vehicle width direction and the seat width direction.

[0031] First Embodiment First, a first embodiment will be described. As shown in Fig. 1, an occupant protection device 10 according to the first embodiment is composed of a vehicle seat 12 and an airbag device 30. The vehicle seat 12 is a front seat or a rear seat of a vehicle (automobile). Here, the vehicle seat 12 is a rear seat, not a front seat 13 (see Figs. 5 to 7). The vehicle seat 12 has a seat cushion 14, a seat back 16 rotatably provided at the rear end of the seat cushion 14, and a headrest 18 provided at the upper end of the seat back 16 so as to be movable up and down.

[0032] In addition, in FIG. 1 and other figures, a crash test dummy (human dummy) D is shown seated on a seat cushion 14 of a vehicle seat 12 as a model of an occupant (seat occupant) to be protected. The dummy D is, for example, a frontal crash test dummy (Hybrid III) AM50 (50th percentile of American adult males). The dummy D is seated in a standard seating position defined by the crash test method, and the vehicle seat 12 is positioned at a reference setting position corresponding to the seating position. For ease of understanding, the dummy D will be referred to as "occupant D" below.

[0033] 1 and 2, an occupant D seated on a seat cushion 14 of a vehicle seat 12 is restrained in the vehicle seat 12 by a seat belt 22 provided in a seat belt device 20. The seat belt device 20 is a three-point seat belt device, and is a so-called seat-mounted seat belt device in which a retractor and anchor, not shown, and a buckle are each provided on the vehicle seat 12.

[0034] The airbag device 30 includes an airbag 32, a pair of inflators 44 (see FIG. 3), and a module case 46. The airbag 32 is normally stored in a folded state in the module case 46 together with the pair of inflators 44. The module case 46 is formed in a hollow rectangular parallelepiped shape. The module case 46 is disposed in the upper rear portion of the vehicle seat 12 (more specifically, above the seat back 16 and behind the headrest 18), and is fixed to the upper end of the seat back 16 or to the vehicle body (not shown).

[0035] The airbag 32 is supplied with gas from a pair of inflators 44 and inflates (deploys and inflates) from the rear side of the vehicle seat 12, passing above the rear side, and toward the front side. The airbag 32 has a front-rear chamber 34 and an airbag main body 40. The front-rear chamber 34 has a pair of left and right front-rear extending portions 34A that extend in the front-rear direction and pass on both the left and right sides of the head H of the occupant D, and a connecting portion 34B that connects the front ends of the pair of front-rear extending portions 34A in the left-right direction. The airbag main body 40 inflates and deploys toward the occupant D (rear side) behind the connecting portion 34B with a delay relative to the front-rear chambers 34, and is positioned between the pair of front-rear extending portions 34A and in front of the occupant D.

[0036] As shown in Fig. 3, the front and rear chambers 34 are formed into a long bag shape by overlapping two long pieces of base fabric 36, 38 and sewing their peripheral edges together at a seam S1. As shown in Fig. 4, the airbag main body 40 is formed into a bag shape by folding a single piece of base fabric 42 along four fold lines L1, L2, L3, and L4 and sewing it together at a seam S2.

[0037] In the sewn portion S2, a sewing line S21 is sewn to a sewing line S22, a sewing line S23 is sewn to a sewing line S24, a sewing line S25 is sewn to a sewing line S26, and a sewing line S27 is sewn to a sewing line S28. The base fabrics 36, 38, and 42 are made of, for example, a polyamide or polyester fabric material. One or both of the two base fabrics 36, 38 that make up the front and rear chambers 34 are made of a base fabric that is less stretchy than the base fabric 42 that makes up the airbag body 40.

[0038] 3, both longitudinal ends of the front and rear chamber 34 (rear ends of the pair of front and rear extending portions 34A) are configured as a pair of inflator accommodating portions 34C that accommodate a pair of left and right inflators 44. In other words, the longitudinal center portion of the front and rear chamber 34 (portion connecting the front ends of the pair of front and rear extending portions 34A in the left-right direction) is configured as a connecting portion 34B, and the portions between the connecting portion 34B and the pair of inflator accommodating portions 34C are configured as front and rear extending portions 34A.

[0039] Although not shown, the airbag device 30 includes a control device (ECU) that controls the activation of the pair of inflators 44. The control device is electrically connected to the pair of inflators 44 and a collision sensor (including a camera, etc.) not shown, and is configured to be able to detect a frontal collision of the vehicle or predict (hereinafter referred to as "prediction") the inevitability of a frontal collision. The control device activates the pair of inflators 44 when it detects or predicts a frontal collision of the vehicle based on information from the collision sensor.

[0040] The pair of inflators 44 are, for example, combustion-type cylinder-type inflators, and are configured to generate high-temperature gas when activated by a control device during a frontal collision of the vehicle. Note that the types of frontal collisions of the vehicle in which the control device activates the inflators 44 include not only full-wrap frontal collisions, but also offset frontal collisions such as oblique collisions and small-wrap collisions.

[0041] A pair of inflator housing sections 34C that house a pair of inflators 44 are arranged separately on the left and right sides of the module case 46. Each inflator 44 housed in each inflator housing section 34C is arranged with its axial direction aligned with the up-down direction of the seat back 16. Each inflator 44 is provided with, for example, a pair of upper and lower stud bolts (not shown).

[0042] A pair of stud bolts penetrates the inflator housing 34C, the module case 46, and a frame (not shown) of the seat back 16, and a nut (not shown) is screwed onto each stud bolt. This fixes the inflator housing 34C, the inflator 44, and the module case 46 to the frame of the seat back 16.

[0043] Each of the pair of front-rear extending portions 34A is formed in a long, tubular shape. An expanded portion 34B1 is integrally formed in the left-right center of the connecting portion 34B. The expanded portion 34B1 protrudes downward from both left-right ends of the connecting portion 34B to which the pair of front-rear extending portions 34A are connected. In other words, the connecting portion 34B is formed in a generally "T"-shaped bag shape that communicates with each of the front-rear extending portions 34A. A communication hole 48 is provided on the rear side of the left-right center of the connecting portion 34B, including the expanded portion 34B1.

[0044] That is, the periphery of a through-hole 50 formed in the base fabric 36 of the front and rear chambers 34 and the periphery of a through-hole 52 (see FIG. 4) formed in the base fabric 42 of the airbag main body 40 are sewn together to form a sewn portion S3, and the through-hole 50 and the through-hole 52 are connected to each other to form a communication hole 48. The through-hole 50 and the through-hole 52 are formed in a generally inverted trapezoidal shape, for example. Therefore, the sewn portion S3 is formed in a generally inverted trapezoidal shape, for example, and the communication hole 48 that connects the inside of the connecting portion 34B and the inside of the airbag main body 40 is located inside the sewn portion S3.

[0045] Furthermore, the pair of front and rear extending portions 34A, the connecting portion 34B, and the airbag main body 40 are normally folded in a predetermined manner, such as roll folding or accordion folding, and housed inside the module case 46. The module case 46 is formed with a tear line (not shown). This tear line is configured to tear when it receives the inflation pressure of the airbag 32 when the airbag 32 inflates and deploys. This allows the airbag 32 to inflate and deploy outward from the module case 46 in the order of the pair of front and rear extending portions 34A, the connecting portion 34B, and the airbag main body 40.

[0046] The pair of inflated and deployed front-rear extending portions 34A extend in the front-rear direction on both the left and right sides of the head H of the occupant D, facing each other with a gap between them on both the left and right sides of the head H. The front ends of the pair of inflated and deployed front-rear extending portions 34A are connected in the left-right direction by the inflated and deployed connecting portion 34B. As a result, the front-rear chamber 34, including the pair of front-rear extending portions 34A and the connecting portion 34B, is configured to have a substantially U-shape that opens rearward in a plan view (see FIGS. 10, 12, and 14).

[0047] The airbag body 40 is supplied with gas from the communication holes 48 and inflates and deploys rearward (toward the occupant D). That is, the airbag body 40 inflates and deploys toward the occupant D (rearward) rearward of the connecting portion 34B with a delay relative to the front and rear chambers 34. Therefore, when the front and rear chambers 34 inflate and deploy, the airbag body 40 can pass from the rearward to the frontward through the gap between the head H of the occupant D and the ceiling 28 (see FIG. 5) of the vehicle compartment.

[0048] The inflated and deployed airbag body 40 faces the head H, chest C, and abdomen B of the occupant D with gaps in the front-to-rear direction (see FIG. 2). The shape of the airbag body 40 when inflated and deployed is set so that it is sandwiched between the thighs F and chest C of the occupant D from the middle to the latter stages of occupant restraint.

[0049] 1 and 2, a pair of left and right rear tethers 54 are attached to the airbag 32. The rear tethers 54 are formed in the shape of long strips from a fabric material, such as a polyamide or polyester material. The fabric material forming the rear tethers 54 is configured to be less stretchable than the base fabrics 36, 38 forming the front and rear chambers 34 and the base fabric 42 forming the airbag body 40. This resistance to stretch is adjusted by the material and thickness of the fabric.

[0050] One end of each of the pair of rear tethers 54 is attached by sewing to the left and right wall surfaces on the front side of a lower portion of the airbag body 40 that inflates and deploys downward from the front and rear chambers 34. The other end of each of the pair of rear tethers 54 is attached to the side of the seat back 16 (or to the vehicle body (not shown) rearward from the occupant D). Therefore, when the airbag 32 is inflated and deployed, the pair of rear tethers 54 extend obliquely downward and rearward below the pair of front and rear extending portions 34A.

[0051] That is, the pair of rear tethers 54 assume an inclined posture inclined diagonally downward and rearward in a side view. As a result, when the airbag 32 restrains the occupant D, the airbag body 40 is relatively drawn (pulled) diagonally downward and rearward by the pair of rear tethers 54, and the airbag body 40 and the front parts of the pair of front-rear extending parts 34A are relatively drawn diagonally downward and rearward with the module case 46 as the rotation center.

[0052] 1 and 2, the airbag 32 is provided with front upper tethers 56 as a pair of left and right upper tethers and front lower tethers 58 as a pair of left and right lower tethers. The front upper tethers 56 and the front lower tethers 58 are configured as surface tethers that are symmetrical and have a generally triangular shape in a side view, and are made of, for example, a polyamide or polyester fabric material. The fabric material that makes up the front upper tethers 56 and the front lower tethers 58 is configured to be less stretchable than the base fabrics 36, 38 that make up the front and rear chambers 34 and the base fabric 42 that makes up the airbag body 40. This resistance to stretch is adjusted by the material and thickness of the fabric.

[0053] The pair of front upper tethers 56 are configured to connect the left and right wall surfaces at the front of an upper portion of the airbag body 40 that inflates and deploys above the front and rear chambers 34 to the front portions of the pair of front and rear extending portions 34A. That is, the front peripheral portions 56F of the pair of front upper tethers 56 are sewn to the left and right wall surfaces at the front of the upper portion of the airbag body 40 that inflates and deploys above the front and rear chambers 34. The lower peripheral portions 56D of the pair of front upper tethers 56 are sewn to the front portions of the pair of front and rear extending portions 34A.

[0054] The pair of front lower tethers 58 are configured to connect the left and right ends of the connecting portion 34B to the front portions of the pair of front-rear extending portions 34A, respectively. That is, the front edge portions 58F of the pair of front lower tethers 58 are sewn to the left and right end portions of the connecting portion 34B, respectively. The upper edge portions 58U of the pair of front lower tethers 58 are sewn to the front portions of the pair of front-rear extending portions 34A, respectively.

[0055] Next, the operation of the airbag device 30 and the occupant protection device 10 according to the first embodiment configured as above will be described.

[0056] When a frontal collision of the vehicle is detected (or predicted) by the collision sensor, the pair of inflators 44 are activated under the control of the control device. That is, gas is ejected from each of the inflators 44 in the pair of inflator housing portions 34C. The gas generated in the pair of inflator housing portions 34C flows through the pair of front and rear extending portions 34A toward the connecting portion 34B, and is supplied into the airbag body 40 through the communication holes 48.

[0057] 5, the tear line of the module case 46 is first ruptured by the inflation pressure of the airbag 32, and the airbag 32 inflates and deploys forward (as indicated by the arrow) from the rear side of the vehicle seat 12, passing above the upper side. That is, the airbag 32 deploys forward from the upper rear part of the seatback 16, passing above the headrest 18 and above the head H of the occupant D.

[0058] Next, as shown in Fig. 6, the head H of the occupant D is relatively inserted into the gap surrounded by the front-rear extending portions 34A of the pair of front-rear chambers 34 and the airbag main body 40 (see Fig. 7). In other words, the front-rear extending portions 34A of the pair of front-rear chambers 34 are deployed forward (as indicated by the arrows) while being positioned on both the left and right sides of the head H of the occupant D.

[0059] 7, gas is supplied from the connecting portion 34B that connects the front ends of the front and rear extending portions 34A of the pair of front and rear chambers 34 in the left-right direction, causing the airbag body 40 to inflate and deploy toward the occupant D (rearward as indicated by the arrow). That is, as shown in FIG. 2, the airbag body 40 is disposed between the pair of front and rear chambers 34 and in front of the occupant D.

[0060] When the airbag body 40 is inflated and deployed, the pair of front upper tethers 56 connect both left and right portions on the front side of the upper part of the airbag body 40 to the front portions of the pair of front and rear extending portions 34A. The pair of front upper tethers 56 can prevent the airbag body 40 from being accidentally displaced (rotated) upward about the connecting portions 34B relative to the front and rear chambers 34 when inflation and deployment of the airbag body 40 (airbag 32) is complete.

[0061] Furthermore, when the airbag body 40 is inflated and deployed, the pair of lower front tethers 58 connect the left and right portions of the front lower part of the airbag body 40 to the front portions of the pair of front and rear extending portions 34A via the connecting portion 34B. The pair of lower front tethers 58 can prevent the airbag body 40 from being accidentally displaced (rotated) downward about the connecting portion 34B relative to the front and rear chambers 34 when inflation and deployment of the airbag body 40 (airbag 32) is complete.

[0062] Furthermore, when the airbag 32 has completed inflation and deployment, the pair of rear tethers 54 extend obliquely downward and rearward below the pair of front-rear extending portions 34A. That is, the pair of rear tethers 54 restrict the movement of the airbag body 40 obliquely upward and forward. This makes it possible to suppress the swinging of the airbag 32 in the up-down and front-rear directions (contributing to stabilizing the deployment behavior of the airbag body 40).

[0063] In this state, the occupant D, who has inertially moved forward due to the impact of a frontal collision of the vehicle, is restrained by the airbag body 40. Specifically, when the occupant D is restrained, the front and rear chambers 34 (front and rear extensions 34A) are expanded forward due to the forward movement of the occupant D. Then, the airbag body 40 is pressed forward by the occupant D, and is compressed and deformed forward.

[0064] This improves the energy absorption performance of the airbag body 40. In other words, when both the front and rear chambers 34 and the airbag body 40 are subjected to a tensile load, the load applied to the occupant D from the airbag body 40 increases steadily, but the compressive deformation of the airbag body 40 can reduce the load applied to the occupant D.

[0065] Moreover, the airbag body 40 is shaped so as to be sandwiched between the thighs F and chest C of the occupant D from the middle to later stages of restraining the occupant with the airbag 32, and is therefore able to come into contact with a wide area of the upper body of the occupant D. This effectively reduces the load applied to the occupant D from the airbag body 40.

[0066] Furthermore, after the front and rear chambers 34 are inflated and deployed, the airbag body 40 is inflated and deployed toward the occupant D on the rear side of the connecting portion 34B, thereby reducing the gap between the airbag body 40 and the occupant D. This allows the occupant D to be restrained by the airbag body 40 early, thereby improving the initial restraint performance of the airbag body 40 on the occupant D.

[0067] Furthermore, when the front and rear chambers 34 are inflated and deployed, gas is supplied to the airbag body 40 from the inflator 44 through a communication hole 48 formed on the rear side of the center portion in the left-right direction of the connecting portion 34B. In other words, the gas that is ejected from the inflator 44 and flows through the pair of front and rear extending portions 34A and the connecting portion 34B of the front and rear chambers 34 is supplied into the airbag body 40 through the communication hole 48.

[0068] Therefore, the airbag body 40 can be inflated and deployed with a sufficient delay relative to the front and rear chambers 34. In other words, the airbag body 40 can be easily inflated and deployed rearward after passing through the narrow gap between the head H of the occupant D and the ceiling 28 of the vehicle compartment from the rear side to the front side due to inflation and deployment of the front and rear chambers 34 (see FIGS. 5 to 7). This prevents the airbag body 40 from getting stuck in the narrow gap, and inhibits or prevents the airbag 32 from failing to deploy.

[0069] The front upper tether 56 and the front lower tether 58 are surface tethers that are bilaterally symmetrical and have a generally triangular shape in a side view. That is, the gap between the front part of the front-rear chamber 34 (front-rear extension 34A) and the lower front part of the airbag main body 40 below it is covered by the front lower tether 58. And the gap between the front part of the front-rear chamber 34 (front-rear extension 34A) and the upper front part of the airbag main body 40 above it is covered by the front upper tether 56.

[0070] Therefore, even when the vehicle is involved in an offset collision or a diagonal collision and the occupant D moves diagonally forward, the airbag 32 can, during the latter half of the restraint of the occupant D, restrain or prevent at least the head H of the occupant D from entering the gap between the front part of the front-rear chamber 34 (front-rear extension part 34A) and the front lower part of the airbag main body 40 (the neck N (see FIGS. 1 and 5) of the occupant D from entering the gap and being twisted) by the front lower tether 58. Therefore, the occupant D can be appropriately restrained.

[0071] Similarly, even when the vehicle is involved in an offset collision or a diagonal collision and the occupant D moves diagonally forward, the airbag 32 can, during the latter half of the restraint of the occupant D, restrain or prevent at least the head H of the occupant D from entering the gap between the front part of the front-rear chamber 34 (the front-rear extension part 34A) and the upper front part of the airbag main body 40 (the neck N of the occupant D from entering the gap and being twisted) by the front upper tether 56. Therefore, the occupant D can be appropriately restrained.

[0072] Second Embodiment Next, a second embodiment will be described. Note that the same reference numerals are used to designate parts equivalent to those in the first embodiment, and detailed descriptions (including common functions) will be omitted as appropriate.

[0073] 8 and 9, the second embodiment differs from the first embodiment only in that the front upper tether 56 and the front lower tether 58 are configured as bilaterally symmetrical bags that are generally triangular in side view and are made of, for example, a polyamide or polyester fabric material. In other words, the front upper tether 56 serves as the upper inflatable portion, and the front lower tether 58 serves as the lower inflatable portion.

[0074] The fabric material constituting the front upper tether 56 as the upper inflatable portion and the front lower tether 58 as the lower inflatable portion is configured to be less stretchable than the base fabrics 36, 38 constituting the front and rear chambers 34 and the base fabric 42 constituting the airbag body 40. This resistance to stretch is adjusted by the material and thickness of the fabric.

[0075] Furthermore, in the lower edge portions 56D of the pair of front upper tethers 56 sewn to the front portions of the pair of front and rear extending portions 34A, only the seat width direction inner end portions thereof are left unsewn. That is, in the front portions of the pair of front and rear extending portions 34A, in the portion corresponding to the seat width direction inner end portions of the lower edge portions 56D of the front upper tethers 56, one of the base cloths constituting the front upper tethers 56 is sewn to the base cloth 36 of the front and rear chamber 34, and the other base cloth constituting the front upper tethers 56 is sewn to the base cloth 38 of the front and rear chamber 34. However, the base cloths 36 and 38 are not sewn together in that portion. As a result, an upper communicating hole 56A is formed in that portion.

[0076] The upper communication hole 56A allows gas to be supplied from the airbag body 40 to the front upper tether 56 via the connecting portion 34B and the front portions of the pair of front and rear extending portions 34A at least when the occupant D is restrained by the airbag body 40. The size (opening area) of the upper communication hole 56A is set to be significantly smaller than the size (opening area) of the communication hole 48.

[0077] Furthermore, in the upper peripheral portions 58U of a pair of front lower tethers 58 sewn to the front portions of the pair of front and rear extending portions 34A, only the inner end portions in the seat width direction are left unsewn. That is, in the front portions of the pair of front and rear extending portions 34A, in the portion corresponding to the inner end portions in the seat width direction of the upper peripheral portions 58U of the front lower tethers 58, one of the base cloths constituting the front lower tethers 58 is sewn to the base cloth 36 of the front and rear chamber 34, and the other base cloth constituting the front lower tethers 58 is sewn to the base cloth 38 of the front and rear chamber 34. However, the base cloth 36 and the base cloth 38 are not sewn together in that portion. As a result, a lower communicating hole 58A is formed in that portion.

[0078] The lower communication hole 58A allows gas to be supplied from the airbag body 40 to the front lower tether 58 via the connecting portion 34B and the front portions of the pair of front and rear extending portions 34A at least when the occupant D is restrained by the airbag body 40. The size (opening area) of the lower communication hole 58A is set to be significantly smaller than the size (opening area) of the communication hole 48.

[0079] In the airbag 32 configured as described above, the front lower tether 58 is a bag-shaped tether (lower inflatable portion). That is, the gap between the front portion of the front-rear chamber 34 (front-rear extending portion 34A) and the front lower portion of the airbag main body 40 is covered by the inflated and deployed front lower tether 58. Therefore, even when the vehicle undergoes an offset collision or an oblique collision and the occupant D moves obliquely forward, the airbag 32 can suppress or prevent at least the head H of the occupant D from entering the gap during the latter half of the restraint of the occupant D (from the middle to the latter half). Therefore, the occupant D can be appropriately restrained.

[0080] Similarly, in this airbag 32, the front upper tether 56 is a bag-shaped tether (upper inflatable portion). In other words, the gap between the front portion of the front-rear chamber 34 (front-rear extending portion 34A) and the upper front portion of the airbag main body 40 is covered by the inflated and deployed front upper tether 56. Therefore, even when the vehicle is involved in an offset collision or an oblique collision and the occupant D moves obliquely forward, the airbag 32 can suppress or prevent at least the head H of the occupant D from entering the gap during the latter half of the restraint of the occupant D (from the middle to the latter half). Therefore, the occupant D can be appropriately restrained.

[0081] Furthermore, the opening area of the lower communication hole 58A is set smaller than the opening area of the communication hole 48. Therefore, even in a configuration in which the bag-shaped front lower tether 58 (lower inflation portion) is provided, there is no delay in deployment of the airbag body 40. In other words, it is possible to suppress or prevent the occurrence of a problem in which the front lower tether 58 is inflated and deployed before the airbag body 40 is inflated and deployed.

[0082] Similarly, the opening area of the upper communication hole 56A is set smaller than the opening area of the communication hole 48. Therefore, even in a configuration in which the bag-shaped front upper tether 56 (upper inflation portion) is provided, there is no delay in deployment of the airbag body 40. In other words, it is possible to suppress or prevent the occurrence of a problem in which the front upper tether 56 is inflated and deployed before the airbag body 40 is inflated and deployed.

[0083] Note that a single or multiple seams (sewn portions) may be formed at least in the bag-shaped front lower tether 58 (lower inflatable portion) to adjust the volume of the front lower tether 58 (lower inflatable portion). This can further improve occupant protection performance. Also, the front lower tether 58 (lower inflatable portion) and the front upper tether 56 (upper inflatable portion) may be configured to be provided only on one side (the side opposite the side door) where, for example, a curtain airbag (not shown) is not provided.

[0084] <Third embodiment> Next, a third embodiment will be described. Note that the same reference numerals are used to designate parts equivalent to those in the first and second embodiments, and detailed descriptions (including common functions) will be omitted as appropriate.

[0085] 10, the third embodiment differs from the first embodiment only in that a convex bulge 60 that protrudes inward in the seat width direction is integrally formed on the front portions of the inner surfaces of the pair of front-rear extending portions 34A (front-rear chambers 34) that face each other in the left-right direction so as to fill the gap between the airbag body 40 and the pair of front-rear extending portions 34A. The bulge 60 protrudes in a substantially arc shape in plan view and front view, and its maximum protruding height is set to a height that allows it to come into contact with or press against the wall surfaces on both the left and right sides of the airbag body 40 with a predetermined pressure.

[0086] 11(A) and 11(B), even when the vehicle is involved in an offset collision or an oblique collision and at least the head H of the occupant D moves obliquely forward, as shown in FIG. 11(C), the bulging portion 60 can suppress or prevent at least the head H of the occupant D from entering the gap between the front of the front-rear chamber 34 (front-rear extension portion 34A) and the airbag main body 40 (from the middle to the late stage) of restraining the occupant D. Therefore, the occupant D can be appropriately restrained.

[0087] Furthermore, by providing this bulge portion 60, it is possible to reduce the amount of head movement of the occupant D in the front-rear and left-right directions. Therefore, even if the front lower tether 58 is a band-shaped tether with a predetermined width, the bulge portion 60 can physically inhibit or prevent the head H from entering the band-shaped front lower tether (not shown). In other words, the bulge portion 60 can inhibit or prevent the neck N of the occupant D from hitting (getting caught on) the band-shaped front lower tether.

[0088] <Fourth embodiment> Next, a fourth embodiment will be described. Note that the same reference numerals are used to designate parts equivalent to those in the first to third embodiments, and detailed descriptions (including common functions) will be omitted as appropriate.

[0089] 12, the fourth embodiment differs from the first embodiment in that one end of each guide cloth 62 is sewn to the front portions of the inner surfaces of the pair of front and rear extending portions 34A (front and rear chambers 34) that face each other in the left and right direction, and the other end of each guide cloth 62 is sewn to the wall surfaces on both the left and right sides of the airbag body 40, thereby covering the gap between the front portions of the pair of front and rear extending portions 34A and the airbag body 40. The guide cloth 62 is formed from the same fabric material as the base fabrics 36, 38, 42, and its width in the up-down direction is approximately the same as the width of the front and rear extending portions 34A in the up-down direction.

[0090] 13(A) and 13(B), even when the vehicle experiences an offset collision or an oblique collision and at least the head H of the occupant D moves obliquely forward, as shown in FIG. 13(C), the guide cloth 62 can suppress or prevent at least the head H of the occupant D from entering the gap between the front of the front-rear chamber 34 (front-rear extension portion 34A) and the airbag main body 40 (from entering the gap and twisting the neck N of the occupant D) during the latter half of the restraint of the occupant D (from the middle to the later stage), as shown in FIG. 13(C). Therefore, the occupant D can be appropriately restrained.

[0091] Furthermore, by providing this guide cloth 62, it is possible to reduce the amount of head movement of the occupant D in the front-rear and left-right directions. Therefore, even if the front lower tether 58 is a band-shaped tether with a predetermined width, the guide cloth 62 can physically restrain or prevent the head H from entering the band-shaped front lower tether (not shown). In other words, the guide cloth 62 can restrain or prevent the neck N of the occupant D from hitting (getting caught on) the band-shaped front lower tether.

[0092] Fifth Embodiment Finally, a fifth embodiment will be described. Note that the same reference numerals are used to designate parts equivalent to those in the first to fourth embodiments, and detailed descriptions (including common functions) will be omitted as appropriate.

[0093] 14, the fifth embodiment differs from the first embodiment only in that a recess 64 recessed forward in plan view is formed over the entire height of the rear wall (rear wall surface) of the airbag body 40 in the left-right central portion of the rear wall. The recess 64 is formed by providing at least two band-shaped tethers 66, each having a predetermined length (a length shorter than the rearward inflation and deployment length of the airbag body 40 in plan view) extending in the front-rear direction, spaced apart from one another in the vertical direction inside the airbag body 40.

[0094] With the airbag 32 configured in this manner, even when the vehicle experiences an offset collision or an oblique collision and at least the head H of the occupant D moves diagonally forward as shown in Figures 15(A) and 15(B), at least the head H of the occupant D does not come out of the recess 64 of the airbag body 40 and is held in the airbag body 40 during the latter half of the restraint of the occupant D (from the middle to the late stage), as shown in Figure 15(C).

[0095] That is, during the latter half of the restraint of the occupant D (from the middle to the latter stage), the recess 64 of the airbag body 40 can suppress or prevent at least the head H of the occupant D from entering the gap between the front part of the front-rear chamber 34 (front-rear extension portion 34A) and the airbag body 40 (the neck N of the occupant D from twisting due to the gap). Therefore, the occupant D can be appropriately restrained.

[0096] Furthermore, by forming the recess 64 in the airbag body 40, the amount of head movement of the occupant D in the front-rear and left-right directions can be reduced. Therefore, even if the front lower tether 58 is a band-shaped tether with a predetermined width, for example, it is possible to physically suppress or prevent the head H from entering the band-shaped front lower tether (not shown). In other words, it is possible to suppress or prevent the neck N of the occupant D from hitting (getting caught on) the band-shaped front lower tether.

[0097] The airbag device 30 and the occupant protection device 10 according to this embodiment have been described above with reference to the drawings. However, the airbag device 30 and the occupant protection device 10 according to this embodiment are not limited to those shown in the drawings, and can be modified in design as appropriate within the scope of the gist of the present invention.

[0098] For example, one end of each of the pair of rear tethers 54 may be sewn and attached to the longitudinal middle portion of the pair of front and rear extending portions 34A, more specifically, to the front portion of each of the inflated and deployed front and rear extending portions 34A, rather than to the left and right wall surfaces on the front side of the lower portion of the airbag body 40 that inflates and deploys downward from the front and rear chambers 34.

[0099] In the first embodiment, it is sufficient that at least the front lower tether 58 of the front upper tether 56 and the front lower tether 58 is a surface tether. In the second embodiment, it is sufficient that at least the front lower tether 58 of the front upper tether 56 and the front lower tether 58 is a bag-shaped tether (lower inflatable portion). [Explanation of symbols]

[0100] 10 Occupant protection devices 12 Vehicle seats 30 Airbag device 32 Airbag 34 Front and rear chambers 40 Airbag body 44 Inflator 48 Communication hole 56 Front upper tether (upper tether / upper inflation part) 56A Upper communication hole 58 Front lower tether (lower tether / lower inflation part) 58A Lower communication hole 60 Bulge 62 Induction cloth 64 recess

Claims

1. an inflator that generates gas when the vehicle crashes; an airbag that is supplied with gas generated by the inflator and inflates and deploys from a rear side of the vehicle seat through an upper side of the seat to a front side of the seat; Equipped with The airbag in an inflated and deployed state is a pair of front and rear chambers extending in a front-rear direction of the seat and passing through both left and right sides of the head of an occupant seated in the vehicle seat; an airbag body that is connected to the pair of front and rear chambers, that is disposed between the pair of front and rear chambers on the seat front side of the occupant, and that is compressed and deformed while being supported by the pair of front and rear chambers when the occupant is restrained; a pair of left and right upper tethers connecting the front and rear chambers and an upper portion of the airbag body; a pair of left and right lower tethers connecting the front and rear chambers to a lower portion of the airbag body; and In the airbag device, at least the lower tether of the upper tether and the lower tether is a surface tether that is approximately triangular in shape and has a symmetrical shape that covers the gap, so as to prevent at least the occupant's head from getting caught in the gap between the front and rear chambers and the airbag body during the latter half of the restraint of the occupant.

2. The lower tether 2. The airbag device according to claim 1, wherein the airbag body has a lower inflatable portion that fills a gap between the front and rear chambers and a lower portion of the airbag body.

3. The upper tether is 3. The airbag device according to claim 2, wherein the surface tether is a substantially triangular surface tether having a bilaterally symmetrical shape that covers the gap, and the upper inflatable portion fills the gap between the front and rear chambers and the upper portion of the airbag body.

4. An airbag device as described in Claim 2, wherein the lower inflation section is configured so that the gas is supplied from the front and rear chambers through a lower communication hole, and the opening area of the lower communication hole is set smaller than the opening area of the communication hole for supplying the gas from the front and rear chambers to the airbag body.

5. 4. The airbag device according to claim 3, wherein the upper inflation portion is configured to receive the gas from the front and rear chambers through an upper communication hole, and the opening area of the upper communication hole is set smaller than the opening area of a communication hole for supplying the gas from the front and rear chambers to the airbag body.

6. 2. The airbag device according to claim 1, wherein convex bulging portions are formed on inner surfaces of the front and rear chambers facing each other in the seat width direction to fill a gap between the airbag body and the front and rear chambers.

7. The airbag is 2. The airbag device according to claim 1, further comprising a pair of guide cloths, one end of which is sewn to the inner surfaces of the front and rear chambers facing each other in the seat width direction, and the other end of which is sewn to the airbag body, to cover the gap.

8. 2. The airbag device according to claim 1, wherein a recess is formed in a plan view in a central portion in the seat width direction on a wall surface of the airbag body on the seat rear side.

9. A vehicle seat for a passenger, the airbag device according to any one of claims 1 to 8, which is mounted in a rear portion of the vehicle seat; An occupant protection device comprising:

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