Airbag device attached to seat

Abstract

The present disclosure provides an airbag device attached to a seat, comprising: an inflator that is provided to a vehicle seat and that ejects gas during a vehicle collision; and an airbag that is provided with an airbag body that, when supplied with gas discharged from the inflator, moves toward the front side of the seat by passing between the head of the occupant seated on the vehicle seat and the ceiling of the vehicle cabin, and expands and deploys the airbag body, and that is disposed on the front side of the seat of the occupant. The airbag is housed in a headrest of the vehicle seat by bending both ends in the seat width direction toward the lower side of the seat so as to follow the outer shape of the headrest when viewed from the front side of the seat in a main view.

Description

Technical Field

[0001] The present disclosure relates to an airbag device attached to a seat. Background Art

[0002] An airbag device with an airbag has long been known, which includes: a rear inflation portion that deploys on the back side of a seat; a pair of side inflation portions that extend forward from the left and right sides of the rear inflation portion; and a pair of front inflation portions that extend from the side inflation portions toward the center side and are connected to each other at the center side to cover the front of the occupant (for example, refer to Japanese Patent Gazette No. 2019-218013).

[0003] In addition, there has long been known an airbag device having a bag body, the bag body having: a body support portion that is deployed from behind the occupant's head to the front of the occupant; a pair of head support portions that are deployed at the left and right sides of the occupant's head and connected to the body support portion (for example, see Japanese Patent Application Publication No. 2019-018593). The bag body is formed with an escape portion that passes through the pair of head support portions in the vertical direction and avoids the occupant's head in the deployed state.

[0004] In the above-mentioned airbag device, the airbag (bag body) is inflated and deployed while passing through the gap between the head of the occupant and the ceiling from the seat back, and is arranged in front of the occupant. However, in order not to hinder the deployment performance of the airbag, if it is desired to be deployed flatly and then rolled into a roll to be mounted in the seat back, the size of the airbag in the seat width direction will be equal to the size of the seat back in the seat width direction. In addition, when such an airbag is mounted near the headrest, the size of its periphery will become larger, and the rear visual confirmation of the occupant will be reduced. Summary of the invention

[0005] The present disclosure provides an airbag device attached to a seat that can compactly store an airbag without hindering the deployment performance of the airbag, wherein the airbag has an airbag body that is inflated and deployed by passing between the head of the occupant and the ceiling of the vehicle compartment and is arranged on the front side of the occupant's seat.

[0006] The first mode of the present disclosure is an airbag device attached to a seat, comprising: an inflation device, which is arranged on the vehicle seat and ejects gas when the vehicle collides; an airbag, which has an airbag body, which is supplied with gas ejected from the inflation device, so that the airbag body moves toward the front side of the seat through between the head of an occupant sitting on the vehicle seat and the ceiling of the vehicle compartment and expands and is arranged in front of the seat of the occupant. When viewed from the front side of the seat, the airbag is bent toward the lower side of the seat at both ends in the seat width direction in a manner along the outer shape of the headrest of the vehicle seat and is stored in the headrest.

[0007] According to the first embodiment of the invention, when a vehicle collides, the gas ejected from the inflator is supplied, so that the airbag body moves to the front side of the seat through the space between the head of the occupant sitting on the vehicle seat and the ceiling of the vehicle compartment, expands and deploys, and is arranged in front of the seat of the occupant. In addition, the "collision" mentioned here also includes the inevitable situation of predicting (foreseeing) a collision.

[0008] Here, the airbag having the airbag body is compactly stored in the headrest with both ends in the seat width direction bent toward the lower side of the seat in a manner along the outer shape of the headrest of the vehicle seat when viewed from the front side of the seat. However, both ends in the seat width direction of the airbag are stretched outward in the seat width direction when inflated and deployed. Therefore, even if both ends in the seat width direction of the airbag are stored bent toward the lower side of the seat, the bend is released and the airbag is deployed when inflated and deployed.

[0009] That is, according to the present disclosure, even if the airbag has an airbag body that is arranged in front of the seat of the occupant by passing between the head of the occupant and the ceiling of the vehicle and inflating and deploying, it can be compactly stored in the headrest without hindering its deployment performance. As a result, it is also possible to suppress the enlargement of the headrest when viewed from the front and side.

[0010] In the second mode of the present disclosure, in the first mode, the two end portions of the airbag in the seat width direction are a pair of front and rear chambers that are supplied with gas ejected from the inflation device and thereby expand and deploy toward the front side of the seat through the left and right sides of the occupant's head, and the airbag body moves toward the front side of the seat through between the occupant's head and the ceiling of the vehicle compartment as the pair of front and rear chambers expand and deploy, and is configured at the front side of the seat of the occupant by being supplied with the gas from the pair of front and rear chambers and thereby expanding and deploying toward the rear side of the seat between the pair of front and rear chambers.

[0011] According to the second embodiment of the invention, both ends of the airbag in the seat width direction are provided with a pair of front and rear chambers that expand and unfold toward the front side of the seat through the left and right sides of the occupant's head by being supplied with gas ejected from an inflator. Furthermore, the airbag body moves toward the front side of the seat through between the occupant's head and the ceiling of the vehicle compartment as the pair of front and rear chambers expand and unfold, and expands and unfolds toward the rear side of the seat between the pair of front and rear chambers by being supplied with gas from the pair of front and rear chambers, thereby being arranged toward the front side of the seat of the occupant. In other words, the airbag body expands and unfolds toward the occupant side with a delay from the pair of front and rear chambers. Therefore, when the occupant is restrained, the airbag body can compress and deform toward the front side of the seat while extending the front and rear chambers, thereby effectively ensuring its occupant restraint performance.

[0012] A third aspect of the present disclosure is characterized in that, in the second aspect, the pair of front and rear chambers are bent toward a seat lower side from a boundary portion with the airbag body.

[0013] According to the third aspect of the invention, the pair of front and rear chambers are bent from the boundary portion with the airbag body toward the lower side of the seat. Here, the rigidity of the boundary portion is the lowest. Therefore, it is easy to bend the pair of front and rear chambers toward the lower side of the seat, thereby facilitating the installation of the airbag on the headrest.

[0014] A fourth aspect of the present disclosure is characterized in that, in the third aspect, the headrest is formed integrally with a seat back of the vehicle seat.

[0015] According to the fourth aspect of the invention, the headrest is formed integrally with the seat back, so that it is possible to prevent the airbag from being detached from the vehicle seat, compared with a case where the headrest and the seat back are separate bodies.

[0016] A fifth aspect of the present disclosure is characterized in that, in the fourth aspect, the seat-attached airbag device is configured such that, when the pair of front and rear chambers are inflated and deployed, left and right airbag doors formed by the rupture of the headrest are rolled up toward the head of the occupant.

[0017] According to the fifth aspect of the invention, when the pair of front and rear chambers are inflated and deployed, the left and right airbag doors formed by the rupture of the headrest are rolled toward the head of the occupant. Therefore, the head of the occupant can be moved toward the center side in the seat width direction by the airbag doors, thereby preventing the occupant's head from hindering the expansion and deployment of the pair of front and rear chambers.

[0018] A sixth aspect of the present disclosure is that in the fourth or fifth aspect, the inflator is disposed singly along the extending direction of the seat back of the vehicle seat and is configured to eject the gas into a distribution pipe capable of supplying the gas to each of the pair of front and rear chambers.

[0019] According to the sixth aspect of the invention, a single inflator is arranged along the extension direction of the seat back of the vehicle seat, and the gas is ejected into the inside of the distribution pipe capable of supplying gas to the pair of front and rear chambers, respectively. Therefore, compared with the case where two inflators are arranged along the direction intersecting the extension direction of the seat back in side view so as to directly supply gas to the pair of front and rear chambers, respectively, the size of the seat back can be suppressed (increase in thickness), and the manufacturing cost can be reduced.

[0020] A seventh aspect of the present disclosure is characterized in that, in the sixth aspect, a discharge port of the distribution pipe connecting the bases of the pair of front and rear chambers extends forward and outward in the seat width direction by a predetermined length in a plan view.

[0021] According to the invention of the seventh aspect, the nozzle of the distribution pipe connected to the root of the pair of front and rear chambers extends forward and outward in the seat width direction by a predetermined length when viewed from above. Therefore, even if the position of the occupant's head is offset in the left-right direction, the inflation and deployment performance of the airbag (a pair of front and rear chambers) can be ensured.

[0022] According to the above aspect, the seat-attached airbag device of the present disclosure can compactly store the airbag without hindering the deployment performance of the airbag having the airbag body that passes between the head of the occupant and the ceiling of the vehicle compartment and inflates and deploys to be arranged in front of the seat of the occupant. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Exemplary embodiments will be described in detail based on the following drawings, in which:

[0024] Figure 1 A schematic perspective view showing a state in which an airbag of an airbag device attached to a seat according to the present embodiment is inflated and deployed;

[0025] Figure 2 A schematic side view showing a state in which an airbag of an airbag device attached to a seat according to the present embodiment is inflated and deployed;

[0026] Figure 3 A schematic plan view showing a state in which an airbag of an airbag device attached to a seat according to the present embodiment is inflated and deployed;

[0027] Figure 4 is a schematic plan view showing the shape of the airbag of the present embodiment before folding;

[0028] FIG. 5A to FIG. 5F A schematic plan view showing a folding process of the airbag of the present embodiment;

[0029] Figure 6is a schematic plan view showing the shape of the airbag after folding according to the present embodiment;

[0030] Figure 7 is a schematic front view showing, in partial section, an airbag housed in a headrest according to the present embodiment;

[0031] Figure 8 It is a schematic front view showing the shape of the distribution pipe in this embodiment with a partial section and omitting the airbag;

[0032] Fig. 9 is a schematic side view showing, in partial section, an airbag housed in a headrest according to the present embodiment;

[0033] Fig.10 is a schematic plan view showing, in partial section, an airbag housed in a headrest according to the present embodiment;

[0034] Fig.11 A schematic plan view showing a state in which the airbag of the present embodiment is in the process of being inflated and deployed from the headrest;

[0035] Fig.12 A schematic side view showing the initial stage of inflation and deployment of the airbag of the present embodiment;

[0036] Fig.13 A schematic side view showing the airbag of the present embodiment in the middle stage of inflation and deployment;

[0037] Fig.14 It is a schematic side view showing the airbag of the present embodiment at the late stage of inflation and deployment. DETAILED DESCRIPTION

[0038] Hereinafter, the embodiments of the present disclosure will be described in detail based on the accompanying drawings. In addition, for the convenience of description, the arrow mark UP appropriately shown in each figure is set to the top of the vehicle and the vehicle seat, the arrow mark FR is set to the front of the vehicle and the vehicle seat, the arrow mark RH is set to the right of the vehicle and the vehicle seat, and the arrow mark LH is set to the left of the vehicle and the vehicle seat. Therefore, in the following description, when the up-down, front-back, left-right directions are recorded without special description, they are set to represent the up-down, front-back, left-right of the vehicle and the vehicle seat. In addition, the left-right direction is synonymous with the vehicle width direction and the seat width direction.

[0039] like Figure 1 As shown, the occupant protection device 10 is composed of a vehicle seat 12 and an airbag device (hereinafter referred to as "airbag device") 30 attached to the seat according to the present embodiment. The vehicle seat 12 is a front seat or a rear seat of a vehicle (automobile). Figure 12 to Figure 14 ) is set as the vehicle seat 12, but the rear seat is set as the vehicle seat 12.

[0040] In addition, Figures 1 to 3 In the figure, as a model of the occupant (seat occupant) to be protected, a collision test dummy (human dummy) is shown seated on the vehicle seat 12. The dummy is, for example, an AM50 (50th percentile of American adult males) dummy (Hybrid III) for a frontal collision test. The dummy sits in a standard sitting posture prescribed by the collision test method, and the vehicle seat 12 is located at a reference setting position corresponding to the sitting posture. Hereinafter, the dummy is referred to as "occupant D".

[0041] The vehicle seat 12 includes: a seat cushion 14 on which an occupant D sits (supporting the buttocks and thighs F of the occupant D); and a seat back 16 which is arranged to extend upward from the rear side of the seat cushion 14 when viewed from the side in the seat width direction and is rotatable with the seat width direction as an axial direction, and supports the back of the occupant D. Moreover, the seat back 16 has an integral headrest 18 at the center of the upper end portion in the seat width direction for supporting the head H of the occupant D. In addition, the rear wall of the headrest 18 is formed by a back plate 19 (see Fig. 9 , Fig.10 )constitute.

[0042] like Figures 1 to 3 As shown, an occupant D sitting on a seat cushion 14 of a vehicle seat 12 is restrained on 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 belt device attached to the seat, in which a retractor, an anchor, and a buckle (not shown) are all provided on the vehicle seat 12.

[0043] The airbag device 30 includes an airbag 32 and a single inflator 44 (see Figure 8 , Fig. 9 The airbag 32 is normally stored in a folded state inside the headrest 18 (see Figure 7 , Fig. 9 , Fig.10 The inflator 44 is a cylinder type formed into a substantially cylindrical shape, for example, by a combustion type or a low temperature gas type, and is provided inside the seat back 16 or from the inside of the seat back 16 to the inside of the headrest 18 along the extension direction of the seat back 16 (with the axial direction oriented in the up-down direction).

[0044] In addition, the airbag device 30 includes a control device (ECU) (not shown) that controls the operation of the inflator 44. The control device is electrically connected to the inflator 44 and a collision sensor (including a camera, etc.) (not shown), and is configured to detect a frontal collision of the vehicle or predict the inevitability of a frontal collision. Furthermore, when the control device detects or predicts a frontal collision of the vehicle based on information from the collision sensor, the inflator 44 is operated.

[0045] That is, the inflator 44 is configured to generate gas and discharge the gas from the ejection port 44A (see FIG. 4A ) by being operated by the control device when a frontal collision of the vehicle is detected or predicted (hereinafter sometimes referred to as “frontal collision of the vehicle”). Figure 8 , Fig. 9 ) is ejected. In addition, the frontal collision of the vehicle in which the control device operates the inflator 44 includes, in addition to a full overlap frontal collision, an eccentric frontal collision such as an oblique collision and a slight overlap collision.

[0046] The airbag 32 is supplied with gas ejected from the inflator 44, and is deployed and inflated forward from the front surface of the headrest 18 through the left and right sides of the head H of the occupant D sitting on the vehicle seat 12 and the upper side of the head H of the occupant D. Specifically, the airbag 32 includes a pair of front and rear chambers 34 and an airbag body 40.

[0047] like Figure 4 As shown, the pair of front and rear chambers 34 have: a pair of left and right front and rear extension portions 34A, which are supplied with gas ejected from the inflator 44, and expand and expand forwardly through the left and right sides of the head H of the occupant D and extend in the front-rear direction; a front side connecting portion 34B (refer to Figures 1 to 3 ), which connects the front end portions of a pair of front and rear extension portions 34A in the left-right direction; and a rear connecting portion 34C, which connects the rear end portions of a pair of front and rear extension portions 34A in the left-right direction.

[0048] The front connecting portion 34B is formed in a substantially T-shaped bag shape (see FIG. 1 ) continuous with the pair of front and rear extending portions 34A. Figures 1 to 3 ). In addition, at the rear ends of the pair of front and rear chambers 34 (front and rear extensions 34A), in other words, at both ends in the seat width direction at the rear surface of the rear side connecting portion 34C, cylindrical roots 36 extending to the rear side are formed integrally, and at the center portion in the seat width direction at the rear surface of the rear side connecting portion 34C, a cylindrical root 38 extending to the rear side is also formed integrally.

[0049] In the following description, the root 36 on the left side is sometimes referred to as "root 36L" and the root 36 on the right side is sometimes referred to as "root 36R". In addition, the left and right roots 36 and the central root 38 are respectively connected to the respective ejection ports 46A and 48A of the branch pipes 46 and 48 of the distribution pipe (diffuser) 50 described later. In addition, the front and rear chambers 34 are formed into a long bag shape (tube shape) by overlapping two long base fabrics and sewing the upper and lower peripheral portions thereof together.

[0050] The airbag body 40 is deployed along with the expansion of the pair of front and rear chambers 34 (front and rear extensions 34A) and penetrates the head H of the occupant D and the ceiling 28 of the vehicle compartment (see FIG. Figure 12 to Figure 14 ) between the pair of front and rear chambers 34 and move forward, gas is supplied from a pair of front and rear chambers 34, thereby expanding and deploying toward the occupant D side (rear side) at the rear side of the front connecting portion 34B in a delayed manner relative to the pair of front and rear chambers 34, and is arranged between the pair of front and rear chambers 34 (front and rear extension portions 34A) and in front of the occupant D.

[0051] The airbag body 40 is formed into a bag shape by folding a base fabric into a predetermined shape and sewing the peripheral edge thereof. The periphery of a communication hole (not shown) formed on the rear surface of the left-right central portion of the base fabric constituting the front and rear chambers 34 and the periphery of a communication hole (not shown) formed on the base fabric of the airbag body 40 are sewn together, thereby connecting the two. The base fabric of the front and rear chambers 34 and the base fabric of the airbag body 40 are each made of a polyamide or polyester cloth material, for example.

[0052] In addition, if Figure 4 As shown, before the airbag body 40 is folded (wound) into a roll shape, the base fabrics 40A placed on the left and right sides of the inner side in the seat width direction are pulled outward in the seat width direction and flattened to be roughly flat. Figure 4 As shown, before the pair of front and rear chambers 34 are folded into a corrugated shape (corrugated shape), the substantially vertical center portion of the base fabric 34D is stretched outward in the seat width direction and flattened to be substantially flat.

[0053] In this state, if FIG. 5A to FIG. 5F The airbag 32 is folded as shown. That is, first, FIG. 5A to FIG. 5C As shown, the airbag body 40 is rolled up from the front side into a roll shape. In other words, the airbag body 40 is folded into an outwardly rolled roll shape so as to be easily unrolled by the inertial force accompanying the movement toward the front side.

[0054] Next, if FIG. 5D to FIG. 5FAs shown in FIG. 1 , the pair of front and rear chambers 34 (front and rear extensions 34A) are folded into a folded shape. In addition, the folded shape of the pair of front and rear chambers 34 (front and rear extensions 34A) is a folded shape that only forms three peaks. Fig. 5F 4 shows a state where the branch pipes 46 and 48 of a distribution pipe 50 described later are connected.

[0055] So, in Figure 6 4 shows a folded state, where the boundary 42 between the airbag body 40 folded into a roll and the pair of front and rear chambers 34 folded into an accordion shape is a folded portion, and the pair of front and rear chambers 34 are bent downward. Figure 7 As described above, it is accommodated inside the headrest 18 .

[0056] That is, the airbag 32 is arranged along the outer shape (upper surface and left and right side surfaces) of the headrest 18 when viewed from the front. In addition, a tear line (not shown) is formed on the front surface of the headrest 18. The tear line is configured to be torn by the expansion pressure of the airbag 32 when the airbag 32 is inflated and deployed. Thus, the airbag 32 can be inflated and deployed from the front surface of the headrest 18 to the front side in the order of the pair of front and rear chambers 34 and the airbag body 40.

[0057] In addition, if Figure 8 As shown in FIG. 1 , a distribution pipe 50 made of resin or metal is arranged at the rear side of the inside of the headrest 18. The distribution pipe 50 branches in three directions and has a cylindrical branch pipe 46 that branches to the left and right from the center of the seat width direction, and a cylindrical branch pipe 48 that branches to the upper side from the center of the seat width direction. In addition, in the following description, the branch pipe 46 that branches to the left from the center of the seat width direction of the distribution pipe 50 is sometimes referred to as "branch pipe 46L", and the branch pipe 46 that branches to the right from the center of the seat width direction of the distribution pipe 50 is sometimes referred to as "branch pipe 46R".

[0058] like Fig. 9 As shown, the nozzle 46A of the left branch pipe 46L and the nozzle 46A of the right branch pipe 46R extend toward the upper front side at a predetermined angle (for example, 20° to 30° relative to the horizontal direction) and a predetermined length when viewed from the side, and the nozzle 48A of the upper branch pipe 48 also extends toward the upper front side at a predetermined angle (for example, 20° to 30° relative to the horizontal direction) and a predetermined length when viewed from the side.

[0059] The "predetermined length" of the jet outlet 46A and the jet outlet 48A mentioned here is preferably set to 30 mm to 40 mm, for example. This is because if the length of the jet outlet 46A and the jet outlet 48A is shorter than 30 mm, the gas may not be ejected in the target direction, and if it is longer than 40 mm, the thickness of the headrest 18 will increase meaninglessly.

[0060] In addition, if Fig.10 As shown, the outlet 46A of the left branch pipe 46L and the outlet 46A of the right branch pipe 46R also extend forward and outward in the seat width direction at a predetermined angle (e.g., 10° to 20° with respect to the front-rear direction) when viewed from above. Fig.11 As shown, the pair of front and rear chambers 34 inflate and deploy toward the outer front in the seat width direction, so that the rolled airbag body 40 is stretched toward the outer side in the seat width direction and moves from the rear side to the front side.

[0061] And, if Figure 4 , Fig. 5F As shown, the outlet 46A of the left branch pipe 46L and the outlet 46A of the right branch pipe 46R are connected to the left root 36L and the right root 36R of the rear connecting portion 34C, respectively, and the outlet 48A of the upper branch pipe 48 is connected to the central root 38 of the rear connecting portion 34C. Fig. 9 As shown, in the state where the airbag 32 is stored inside the headrest 18, the left and right root portions 36L and 36R (in Fig. 9 Only the root 36L on the left side is shown in the figure) and is located approximately in the center in the up-down direction at the rear side of a pair of front and rear chambers 34.

[0062] In other words, when viewed from the side, the outlet 46A of the left branch pipe 46L and the outlet 46R of the right branch pipe 46L (at Fig. 9 The outlet 46A of the branch pipe 46L (only the left side is shown) is located at the approximately middle part in the vertical direction of the rear side of the pair of front and rear chambers 34. Figure 8 As shown, the inner diameters of the discharge port 46A of the left branch pipe 46L and the discharge port 46A of the right branch pipe 46R are set to be the same, and are formed to be larger than the inner diameter of the discharge port 48A of the upper branch pipe 48 (for example, about 1.2 times larger).

[0063] Furthermore, the discharge port 44A of the inflator 44 is connected to the cylindrical base 52 extending downward from the center portion in the seat width direction of the distribution pipe 50. That is, the inflator 44 is configured to discharge gas into the inside of the left branch pipe 46L and the right branch pipe 46R of the distribution pipe 50 which can supply gas to the pair of front and rear chambers 34, respectively, and is configured to discharge gas into the inside of the upper branch pipe 48 of the distribution pipe 50 which can supply gas to the center of the rear connecting portion 34C.

[0064] In addition, if Fig.10 As shown in FIG. 1 , when the pair of front and rear chambers 34 of the airbag 32 expand and deploy, the tear line (not shown) formed on the front surface of the headrest 18 is ruptured by the expansion pressure of the pair of front and rear chambers 34. As a result, a portion of the left and right sides of the front surface of the headrest 18 is turned up toward the head H of the occupant D (toward the inner side in the seat width direction), and the turned-up portions become the left and right airbag doors 24. That is, a portion of the pad 18A formed of polyurethane foam or the like constituting the headrest 18 and a portion of the skin 18B overlapping the pad 18A constitute the airbag doors 24.

[0065] In addition, if Fig. 9 As shown, the structure is as follows, that is, when the airbag body 40 of the airbag 32 causes a tear line (not shown) formed on the front surface of the headrest 18 to rupture, a portion of the upper side of the front surface of the headrest 18 is rolled up toward the head H of the occupant D (toward the downward side), and the rolled up portion becomes the airbag door 24.

[0066] In the airbag device 30 having the above structure, Figures 1 to 3 As shown in the figure, the front and rear extensions 34A of the pair of front and rear chambers 34 after expansion and deployment extend in the front and rear direction at the left and right sides of the head H of the occupant D, and are opposed to the head H with gaps on both sides. In addition, the front end portions of the pair of front and rear extensions 34A after expansion and deployment are connected in the left and right directions by the front connecting portion 34B after expansion and deployment. As a result, the front and rear chambers 34 including the pair of front and rear extensions 34A protruding from the headrest 18 and the front connecting portion 34B become a generally "U"-shaped structure that opens rearward when viewed from above (see FIG. 1 ). Figure 3 ).

[0067] In addition, after the airbag body 40 moves forward as the pair of front and rear chambers 34 expand and deploy, gas is supplied from the front and rear chambers 34 to expand and deploy toward the rear side (the passenger D side). Fig.11As shown, when the pair of front and rear chambers 34 are inflated and deployed, the airbag body 40 remains folded in a roll-like state and passes through the head H of the occupant D and the ceiling 28 of the vehicle compartment from the rear side to the front side (see also Figure 12 to Figure 14 ) between the narrow gaps.

[0068] The airbag body 40 is inflated and deployed toward the occupant D side (rear side) at a delay relative to the pair of front and rear chambers 34 at the rear side of the front connecting portion 34B, and the inflated and deployed airbag body 40 is opposed to the head H, chest C and abdomen B of the occupant D with a gap in the front-rear direction (see FIG. Figures 1 to 3 ). In addition, the shape of the airbag body 40 when inflated and deployed is set so that it is sandwiched between the thigh F and chest C of the occupant D from the middle to the late stage of the occupant restraint.

[0069] In addition, if Figures 1 to 3 As shown in FIG. 1 , a pair of left and right rear tethers 54, a pair of left and right front upper tethers 56, and a pair of left and right front lower tethers 58 are mounted on the airbag 32. The rear tethers 54, the front upper tethers 56, and the front lower tethers 58 are formed of, for example, polyamide or polyester fabrics in the form of long strips. In addition, the fabrics forming the rear tethers 54, the front upper tethers 56, and the front lower tethers 58 are formed in a manner that is difficult to stretch compared to the base fabric forming the front and rear chambers 34. The difficulty of stretching is adjusted by the material and thickness of the fabrics.

[0070] The pair of front upper tethers 56 are respectively connected to the left and right wall surfaces at the front side of the upper portion of the airbag body 40 that expands and deploys upward compared to the front and rear chambers 34, and the front portions of the pair of front and rear extensions 34A. That is, one end portion of each pair of front upper tethers 56 is sewn to the left and right wall surfaces at the front side of the upper portion of the airbag body 40 that expands and deploys upward compared to the front and rear chambers 34. And the other end portions of each pair of front upper tethers 56 are respectively sewn to the front portions of the pair of front and rear extensions 34A.

[0071] The pair of front lower tethers 58 are structured to connect the left and right wall surfaces at the front side of the lower portion of the airbag body 40 that expands and deploys downwardly compared to the front and rear chambers 34, and the front portions of the pair of front and rear extensions 34A. That is, one end portion of each pair of front lower tethers 58 is sewn to the left and right wall surfaces of the lower portion of the airbag body 40 that expands and deploys downwardly compared to the front and rear chambers 34. And the other end portions of each pair of front lower tethers 58 are sewn to the front portions of the pair of front and rear extensions 34A.

[0072] On the other hand, one end of each of the pair of rear tethers 54 is sewn and attached to the lower surface of the front portion of the front and rear chamber 34 (front and rear extension 34A) which is opposite to the substantially center portion of the inflated and deployed airbag body 40 in the side view in the seat width direction. And the other end of each of the pair of rear tethers 54 is attached to the side portion of the seat back 16 (or the vehicle body (not shown) which is on the rear side relative to the occupant D). Therefore, in the inflated and deployed state of the airbag 32, the pair of rear tethers 54 extend obliquely rearward and downward at the lower side of the pair of front and rear extensions 34A.

[0073] That is, the pair of rear tethers 54 are inclined toward the oblique rear lower side when viewed from the side. Therefore, when the occupant D is restrained by the airbag 32, the airbag body 40 is relatively pulled toward the oblique rear lower side (stretched) by the pair of rear tethers 54, and the front portions of the airbag body 40 and the pair of front and rear extensions 34A are relatively pulled toward the oblique rear lower side with the headrest 18 as the rotation center when viewed from the side.

[0074] Next, the operation of the airbag device 30 according to the present embodiment having the above-described structure will be described.

[0075] The airbag 32 having a pair of front and rear chambers 34 and an airbag body 40 is stored in the headrest 18 by bending the pair of front and rear chambers 34 at both ends in the seat width direction downwardly in a manner along the outer shape of the headrest 18 of the vehicle seat 12 in a front view. That is, the airbag 32 is compactly stored inside the headrest 18.

[0076] In addition, the pair of front and rear chambers 34 are bent downward from the boundary portion 42 with the airbag body 40. Here, the boundary portion 42 is the portion with the lowest rigidity in the folded airbag 32. Therefore, it is easy to bend the pair of front and rear chambers 34 downward from the boundary portion 42, and the operation of mounting the airbag 32 in this state inside the headrest 18 can be easily performed.

[0077] Furthermore, the headrest 18 storing the airbag 32 is formed integrally with the seat back 16. Therefore, compared with a case where the headrest 18 and the seat back 16 are separate bodies, it is possible to prevent the airbag 32 (airbag device 30) from detaching from the vehicle seat 12.

[0078] When the collision sensor detects (or predicts) a frontal collision of the vehicle, the inflator 44 operates under the control of the control device. That is, gas is generated and ejected from the inflator 44. The gas ejected from the inflator 44 passes through the distribution pipe 50 and is supplied to the pair of front and rear chambers 34 and the rear connecting portion 34C of the airbag 32.

[0079] Here, the inflator 44 is arranged singly along the extension direction of the seat back 16 of the vehicle seat 12, and ejects gas into the interior of a distribution pipe 50 that can supply gas to a pair of front and rear chambers 34 (left and right roots 36L, 36R) and the rear connecting portion 34C (center root 38), respectively.

[0080] Therefore, compared with the case where the ejection port 44A of the inflator 44 is directly connected to a pair of front and rear chambers 34 (left and right roots 36L, 36R) and the rear connecting portion 34C (central root 38), that is, the three inflators 44 are arranged along a direction intersecting the extension direction of the seat back 16 when viewed from the side (in a manner of protruding obliquely toward the rear and lower side), the enlargement (increase in thickness) of the headrest 18 and the seat back 16 can be suppressed, and the manufacturing cost can be reduced.

[0081] In this way, when gas is supplied to the pair of front and rear chambers 34, the tear line of the headrest 18 is ruptured by the expansion pressure of the pair of front and rear chambers 34, and Fig.12 As shown, the pair of front and rear chambers 34 expands from the front surface of the headrest 18 through the left and right sides of the head H of the occupant D toward the front side.

[0082] At this time, each of the ejection ports 46A of the left and right branch pipes 46L and 46R connected to the left and right root portions 36L and 36R of the pair of front and rear chambers 34 extends forward and outward in the seat width direction at a predetermined angle and a predetermined length in a plan view. Therefore, the pair of front and rear chambers 34 expand and expand forward and outward in the seat width direction as intended.

[0083] Thus, even if the pair of front and rear chambers 34 of the airbag 32 are bent downward relative to the airbag body 40 and stored in the headrest 18, the bending is released and the airbag is deployed during inflation and deployment. Therefore, even if the position of the head H of the occupant D is displaced in the left-right direction, the inflation and deployment performance of the pair of front and rear chambers 34 of the airbag 32 can be ensured.

[0084] Furthermore, when the pair of front and rear chambers are inflated and deployed, the left and right airbag doors 24 formed by the partial rupture of the headrest 18 are rolled up toward the head H of the occupant D (towards the inner side in the seat width direction). Therefore, the left and right airbag doors 24 can move the head H of the occupant D toward the center side in the seat width direction, and can also prevent the head H of the occupant D from hindering the inflation and deployment of the pair of front and rear chambers 34.

[0085] When gas is supplied to the rear connecting portion 34C, the tear line of the headrest 18 is ruptured by the inflation pressure of the rear connecting portion 34C via the airbag body 40, that is, the pressure of the inflated rear connecting portion 34C pressing the airbag body 40 folded in a roll toward the front.

[0086] The airbag body 40 pushed forward by the expanded rear connecting portion 34C moves forward as the pair of front and rear chambers 34 expand and deploy, passing above the head H of the occupant D. At this time, since the pair of front and rear chambers 34 expand and deploy toward the front outside in the seat width direction, the airbag body 40 moves forward while being stretched outward in the seat width direction.

[0087] Furthermore, as described later, after the inflation and deployment of the pair of front and rear chambers 34 are completed, the gas from the inflator 44 is supplied to the airbag body 40 through the communication hole of the front side connecting portion 34B. That is, the gas ejected from the inflator 44 and flowing through the pair of front and rear extensions 34A and the front side connecting portion 34B is supplied to the airbag body 40 through the communication hole. Therefore, the inflation and deployment of the airbag body 40 relative to the pair of front and rear chambers 34 can be delayed sufficiently.

[0088] Thus, the airbag body 40 can be securely and easily passed 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 while the airbag body 40 is folded into a roll shape and deployed as the pair of front and rear chambers 34 expand. Thus, the occurrence of an inconvenience such as the airbag body 40 being stuck in the narrow gap can be prevented, and the occurrence of a deployment failure in the airbag 32 can be suppressed or prevented.

[0089] As described above, the airbag 32 according to the present embodiment includes the airbag body 40 which is arranged in front of the occupant D by passing through the narrow gap between the head H of the occupant D and the ceiling 28 of the vehicle cabin and then inflating and deploying, and the airbag 32 can be compactly stored inside the headrest 18 without hindering its deployment performance. Therefore, it is possible to suppress the enlargement of the headrest 18 in front view and side view, and it is also possible to suppress the reduction of the rear visibility of the occupant D.

[0090] In this way, when the pair of front and rear chambers 34 are expanded and deployed, and the airbag body 40 in a state of being folded into a roll-like shape moves forward, as shown in FIG. Fig.13 As shown, the head H of the occupant D is relatively inserted into a gap portion surrounded by the front-rear extending portions 34A of the pair of front-rear chambers 34 and the airbag body 40 in a state of being folded into a roll shape.

[0091] Moreover, if Fig.14As shown, the airbag body 40 is inflated and deployed toward the occupant D by supplying gas from the front side connecting portion 34B that connects the front end portions of the front and rear extending portions 34A of the pair of front and rear chambers 34 in the left-right direction through the communication hole. That is, the airbag body 40 is arranged between the pair of front and rear chambers 34 and on the front side of the occupant D.

[0092] Furthermore, when the airbag body 40 is inflated and deployed, the pair of front upper tethers 56 connect the left and right sides of the front side of the upper portion of the airbag body 40 and the front portions of the pair of front and rear extensions 34A, respectively. The pair of front upper tethers 56 can prevent the airbag body 40 from being inadvertently displaced (rotated) upward about the front side connection portion 34B relative to the front and rear chambers 34 when the inflation and deployment of the airbag body 40 (airbag 32) is completed.

[0093] Furthermore, when the airbag body 40 is inflated and deployed, the pair of front lower tethers 58 connect the left and right sides of the front side of the lower portion of the airbag body 40 and the front portions of the pair of front and rear extensions 34A, respectively. By means of the pair of front lower tethers 58, when the inflation and deployment of the airbag body 40 (airbag 32) is completed, it is possible to suppress the airbag body 40 from being inadvertently displaced (rotated) downwardly about the front side connection portion 34B relative to the front and rear chambers 34.

[0094] Furthermore, when the inflation and deployment of the airbag 32 is completed, the pair of rear tethers 54 extend obliquely rearward and downward at the lower side of the pair of front-rear extensions 34A. That is, the pair of rear tethers 54 restrict the movement of the airbag body 40 obliquely forward and upward. Thus, the swing of the airbag 32 in the vertical direction and the front-rear direction can be suppressed (which can contribute to the stabilization of the deployment operation of the airbag body 40).

[0095] In this state, the occupant D who has inertially moved forward due to the impact of the frontal collision of the vehicle is restrained by the airbag body 40. Specifically, when restraining the occupant D, the front and rear chambers 34 (front and rear extensions 34A) move forward of the occupant D and extend forward of the occupant D. Furthermore, the airbag body 40 is pressed forward by the occupant D and is compressed and deformed forward of the occupant D.

[0096] Therefore, the energy absorption performance of the airbag body 40 can be improved, and its occupant restraint performance can be effectively ensured. That is, when both the front and rear chambers 34 and the airbag body 40 are subjected to tensile loads, although the load applied to the occupant D from the airbag body 40 increases, the load applied to the occupant D can be reduced by the compression deformation of the airbag body 40.

[0097] Furthermore, since the airbag body 40 is shaped so as to be sandwiched between the thigh F and the chest C of the occupant D from the middle to the late stage of restraining the occupant by the airbag 32, it can contact the upper body of the occupant D over a wide area. As a result, the load applied to the occupant D from the airbag body 40 can be reduced well.

[0098] Furthermore, since the airbag body 40 is inflated and deployed toward the occupant D at the rear side of the front connecting portion 34B after the front and rear chambers 34 are inflated and deployed, the gap between the airbag body 40 and the occupant D becomes smaller. As a result, the occupant D is restrained at an early stage by the airbag body 40, and the initial restraint performance of the occupant D by the airbag body 40 can be improved.

[0099] Furthermore, since the pair of rear tethers 54 are less likely to extend than the front and rear chambers 34, the airbag body 40 is relatively pulled obliquely rearward and downward by the pair of rear tethers 54 when restraining the occupant D. Thus, when restraining the occupant, the position of the airbag body 40 in the vertical direction relative to the head H of the occupant D can be stabilized. That is, according to the airbag 32, the occupant D can be appropriately restrained.

[0100] The airbag device 30 attached to the seat according to the present embodiment has been described above based on the drawings, but the airbag device 30 attached to the seat according to the present embodiment is not limited to the device shown in the drawings, and the design can be appropriately changed without departing from the scope of the present disclosure. For example, the shape of the airbag 32 is not limited to the shape shown in the drawings.

[0101] In addition, the distribution pipe 50 may be provided across the inside of the headrest 18 and the inside of the seat back 16. In addition, although the root portions 36 and 38 are inserted into the inner side of the ejection ports 46A and 48A and installed in the figure, it is not limited to this, and it may be provided to cover the outer side of the ejection ports 46A and 48A and install.

Claims

1. An airbag device attached to a seat, comprising: An inflator that is provided on a vehicle seat and ejects gas when the vehicle collides; The airbag has an airbag body, which is supplied with gas ejected from the inflator, so that the airbag body moves to the front side of the seat through between the head of the occupant sitting on the vehicle seat and the ceiling of the vehicle compartment and expands and is arranged in front of the seat of the occupant. The airbag is stored in the headrest at both ends in the seat width direction that are bent toward the seat lower side so as to follow the outer shape of the headrest of the vehicle seat in a front view seen from the front side of the seat.

2. The seat-attached airbag device according to claim 1, wherein: The airbag has a pair of front and rear chambers at both ends in the seat width direction. The pair of front and rear chambers are supplied with gas ejected from the inflator so as to expand and deploy toward the front side of the seat through the left and right sides of the occupant's head. The airbag body moves toward the front side of the seat through between the occupant's head and the ceiling of the vehicle compartment as the pair of front and rear chambers expand and deploy, and is supplied with the gas from the pair of front and rear chambers, thereby expanding and deploying toward the rear side of the seat between the pair of front and rear chambers, and is arranged in front of the seat of the occupant.

3. The seat-attached airbag device according to claim 2, wherein: The pair of front and rear chambers are bent toward a side below the seat from a boundary portion with the airbag body.

4. The seat-attached airbag device according to claim 3, wherein: The headrest is formed integrally with a seat back of the vehicle seat.

5. The airbag device attached to a seat according to claim 4, wherein: The seat-attached airbag device is configured such that, when the pair of front and rear chambers are inflated and deployed, left and right airbag doors formed by the rupture of the headrest are rolled up toward the head of the occupant.

6. The airbag device attached to a seat according to claim 4 or claim 5, wherein: The inflator is disposed alone along the extending direction of the seat back of the vehicle seat, and is configured to eject the gas into a distribution pipe capable of supplying the gas to each of the pair of front and rear chambers.

7. The airbag device attached to a seat according to claim 6, wherein: The discharge port of the distribution pipe connecting the bases of the pair of front and rear chambers extends forward and outward in the seat width direction by a predetermined length in a plan view.

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