Side airbag device for vehicle

Abstract

To provide a vehicular side airbag device capable of improving initial restraint performance for a head.SOLUTION: A vehicular side airbag device 10 includes: an inflator 38 provided in a side part 14A on an outer side in a vehicle width direction of a seat back 14; and a side airbag 40 which includes an upper chamber 42 inflated and deployed to an outer side in the vehicle width direction relative to a head H of an occupant P upon receiving the supply of gas from the inflator 38, and a lower chamber 44 inflated and deployed to the outer side in the vehicle width direction relative to at least one of a waist W and chest C of the occupant P. The side airbag 40 is stored while being folded in a portion from the side part 14A of the seat back 14 to an upper part 14C of the seat back 14, and is arranged so as to pass, in a shoulder tip part 14D of the seat back 14, through under a belt guide 30 through which a shoulder belt 26A for restraining an upper body of the occupant P is inserted. At least a part 42A of the upper chamber 42 is stored in a portion between a headrest 16 and the belt guide 30.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a side airbag device for a vehicle. [Background technology]

[0002] The following Patent Document 1 discloses a vehicle side airbag device mounted on the outer side of the seat back of a vehicle seat in the vehicle width direction. In this vehicle side airbag device, an inflator is housed in a side airbag having a head protection expansion portion (upper chamber) and a waist protection expansion portion (lower chamber). In the event of a side collision of the vehicle, gas generated from the inflator is supplied to the upper chamber and the lower chamber. As a result, the upper chamber is inflated and deployed to the side of the occupant's head, and the lower chamber is inflated and deployed to the side of the occupant's waist. The following Patent Document 2 discloses a similar technology. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2011-105107 A [Patent Document 2] International Publication No. 2011 / 016107 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the side airbag devices described in Patent Documents 1 and 2 above, the upper chamber is inflated and deployed at a position away from the occupant's head, so there is room for improvement in terms of improving the initial head restraint performance.

[0005] SUMMARY OF THE PRESENT INVETION The present invention has been made in consideration of the above circumstances, and an object of the present invention is to provide a side airbag device for a vehicle that can improve the initial restraint performance of the head. [Means for solving the problem]

[0006] The vehicle side airbag device according to claim 1 is provided in a vehicle seat at a side portion on the outer side in the vehicle width direction of a seat back that supports the back of a seated occupant, and includes an inflator that generates gas when a side collision of the vehicle is predicted or detected, an upper chamber that is supplied with gas from the inflator and inflated and deployed outward in the vehicle width direction against the head of the seated occupant, and a lower chamber that is supplied with gas from the inflator and inflated and deployed outward in the vehicle width direction against at least one of the waist and chest of the seated occupant, and is stored in a folded state from the side portion of the seat back to an upper portion of the seat back, and is disposed at a shoulder portion of the seat back, passing below a belt guide through which a shoulder belt that restrains the upper body of the seated occupant is inserted, One The seat belt guide includes a headrest for supporting the head of a seated occupant in the vehicle seat, and a side airbag that is stored between the headrest and the belt guide. The upper chamber is folded so as to be substantially U-shaped with the outer side in the vehicle width direction being open when viewed from the front side of the vehicle seat, and is disposed along the lower side, the inner side in the vehicle width direction, and the upper side in the vehicle vertical direction of the belt guide. .

[0007] According to the present invention as set forth in claim 1, a shoulder belt is inserted through a belt guide provided at a shoulder portion of a seat back. The upper body of a seated occupant is restrained to the vehicle seat by this shoulder belt.

[0008] Furthermore, when a side collision of the vehicle is predicted or detected, gas is generated from an inflator provided on the outer side of the seat back in the vehicle width direction. This gas is supplied to the upper and lower chambers of the side airbag. The upper chamber, inflated by the supply of gas, is deployed outward in the vehicle width direction toward the head of the seated occupant. Meanwhile, the lower chamber, inflated by the supply of gas, is deployed outward in the vehicle width direction toward at least one of the waist and chest of the seated occupant.

[0009] Here, the side airbag stored in a folded state from the side to the upper part of the seatback is disposed below the belt guide at the shoulder part of the seatback. In other words, the side airbag is disposed below the shoulder belt. Furthermore, the upper chamber of the side airbag One The upper chamber is housed between the headrest and the belt guide, so that the upper chamber is deployed earlier toward the inside in the seat width direction than the belt guide. In addition, the upper chamber is folded so that it is roughly U-shaped with the outer side in the vehicle width direction open when viewed from the front side of the vehicle seat, and is arranged along the lower side, inner side in the vehicle width direction, and upper side in the vehicle vertical direction of the belt guide. Therefore, the upper chamber is deployed early on inward in the seat width direction from the shoulders of the seated occupant restrained by the shoulder belts, i.e., near the head of the seated occupant. Effect of the Invention

[0010] As described above, according to the vehicle side airbag of the present invention, the initial head restraint performance can be improved. [Brief description of the drawings]

[0011] [Figure 1] 1 is a front view showing a vehicle seat equipped with a vehicle side airbag device according to an embodiment of the present invention. [Diagram 2] 2 is an enlarged side view of a main portion of the vehicle seat shown in FIG. [Diagram 3] 2 is a perspective view showing a state in which a side airbag of the side airbag device shown in FIG. 1 is inflated and deployed. FIG. [Figure 4] FIG. 1 is a front view showing a vehicle seat equipped with a vehicle side airbag device according to a first modified example. [Diagram 5] 5 is an enlarged side view of a main portion of the vehicle seat shown in FIG. 4. [Figure 6] FIG. 11 is a front view showing a vehicle seat equipped with a vehicle side airbag device according to a second modified example. [Figure 7] 7 is an enlarged side view of a main portion of the vehicle seat shown in FIG. 6. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] Hereinafter, a vehicle side airbag device 10 according to one embodiment of the present invention will be described with reference to Figs. 1 to 3. Note that the arrows FR, UP, LH, and RH shown as appropriate in each drawing respectively indicate the seat front side, seat upper side, seat width direction left side, and seat width direction right side of a vehicle seat 12 on which the vehicle side airbag device 10 is mounted. Furthermore, when the front-rear, up-down, and left-right directions are used in the following description unless otherwise specified, they respectively indicate front-rear in the front-rear direction of the seat, up-down in the up-down direction of the seat, and left-right in the left-right direction (width direction) of the seat.

[0013] As shown in Figs. 1 to 3, a vehicle side airbag device 10 according to one embodiment of the present invention (hereinafter, referred to as "side airbag device 10") is mounted on a vehicle seat 12. This vehicle seat 12 is, for example, the driver's seat in a right-hand drive vehicle or the passenger seat in a left-hand drive vehicle, and is disposed on the right side of the vehicle interior. The front-rear direction, left-right direction (width direction), and up-down direction of this vehicle seat 12 respectively coincide with the front-rear direction, left-right direction (width direction), and up-down direction of the vehicle. Below, the configurations of the vehicle seat 12 and the vehicle side airbag device 10 will be sequentially described, and then the main parts of this embodiment will be described.

[0014] (Vehicle seat 12) The vehicle seat 12 includes a seat cushion (not shown) configured to support the buttocks and thighs of a seated occupant, a seat back 14 configured to support the back of the occupant, and a headrest 16 configured to support the head of the occupant. The seat cushion (not shown) extends in the front-rear direction and the seat width direction. The seat back 14 extends in the up-down direction and the seat width direction, and is rotatably connected to the rear end of the seat cushion (not shown). The headrest 16 is connected to the upper end of the seat back 14. The configuration of the vehicle seat 12 is not limited to the above, and for example, the headrest 16 may be integrally formed with the seat back 14.

[0015] A dummy P for a crash test is seated in the vehicle seat 12 shown in Figs. 1 to 3 in place of an actual occupant. This dummy P is, for example, AM50 (50th percentile of adult American males) of the WorldSID (World Side Impact Dummy). The dummy P is seated in the vehicle seat 12 in a seating manner prescribed in the side impact test method. The front-rear position of the vehicle seat 12 relative to the vehicle and the inclination angle of the seat back 14 relative to the seat cushion (not shown) are adjusted to standard setting positions corresponding to the above-mentioned seating manner. Hereinafter, for convenience of explanation, the dummy P will be referred to as "occupant P".

[0016] As shown in FIG. 1, the seat back 14 includes a seat back frame 18, which is a skeletal member, a seat back pad (not shown) attached to the seat back frame 18, and a seat back skin 22 (see FIG. 3) covering the seat back pad. The seat back frame 18 is made of, for example, metal or resin. The seat back pad is made of, for example, a foam such as urethane foam. The seat back skin 22 (see FIG. 3) is made by sewing together a plurality of skin pieces made of, for example, a cloth material, a knit material, synthetic leather, leather, etc. In FIG. 1 and FIG. 2, in order to emphasize the main parts, the seat back skin 22 is not shown, and the outlines of the headrest 16 and the seat back 14 are shown by virtual lines.

[0017] The seatback frame 18 comprises an outer side frame 18A extending in the vertical direction at the side portion 14A (hereinafter referred to as the "outer side portion 14A") on the outer side (right side) of the seatback 14 in the vehicle width direction, and an inner side frame 18B extending in the vertical direction at the side portion 14B on the inner side (left side) of the seatback 14 in the vehicle width direction.

[0018] The seatback frame 18 also includes an upper frame 18C that connects the upper ends of the outer side frame 18A and the inner side frame 18B in the seat width direction at an upper portion 14C of the seatback 14. The seatback frame 18 also includes a lower frame (not shown) that connects the lower ends of the outer side frame 18A and the inner side frame 18B in the seat width direction at a lower portion (not shown) of the seatback 14. The configuration of the seatback frame 18 is not limited to the above and can be changed as appropriate.

[0019] Here, the vehicle seat 12 is equipped with a three-point seat belt device 24 capable of restraining an occupant P. The seat belt device 24 is configured to include a long belt-like webbing 26 for restraining an occupant, a retractor 28 (see FIG. 2) for winding up the webbing 26 so that it can be pulled out, and an anchor plate (not shown) to which the other end of the webbing 26 is anchored. A longitudinal middle portion of the webbing 26 is inserted into a belt guide 30 (described later) disposed in a shoulder portion 14D on the outer side (right side) of the seat back 14 in the vehicle width direction. This shoulder portion 14D is located at the upper end of the outer side portion 14A and at the outer end of the upper portion 14C in the vehicle width direction in the seat back 14.

[0020] A tongue plate (not shown) is inserted through the longitudinal middle portion of the webbing 26 and is configured to be detachable from a buckle device (not shown) erected from a seat cushion frame (not shown) on the inner side (left side) in the vehicle width direction. By engaging this tongue plate with the buckle device, the occupant P is restrained by the three-point seat belt device 24, with the upper body being restrained to the seat back 14 by the shoulder belt 26A of the webbing 26 and the waist region W being restrained to the seat cushion by the lap belt (not shown).

[0021] As shown in Fig. 2, one end of the webbing 26 in the longitudinal direction is engaged with a winding shaft (not shown) of a retractor 28, and the webbing 26 is wound in layers by a biasing force. When the webbing 26 is suddenly pulled out, an emergency locking mechanism of the retractor 28 is activated to lock the webbing 26 from being pulled out. The retractor 28 is also provided with a pretensioner mechanism that is activated when a vehicle collision is predicted or detected to forcibly wind up the webbing 26. The retractor 28 is fixed to the back surface of the seat back frame 18 at the shoulder portion 14D of the seat back 14. The retractor 28 does not have to be built into the vehicle seat 12 in this way, and may be fixed to, for example, a lower portion of a center pillar (not shown).

[0022] A belt guide 30 is fixed to the upper side of the retractor 28. The belt guide 30 is formed in a cylindrical shape and in a substantially L-shape in a cross section seen from the seat width direction. The belt guide 30 includes a rear guide 32 extending upward from the upper end of the retractor 28, and an upper guide 36 extending forward from the upper end of the rear guide 32 via a bent portion 34. The rear guide 32 is formed in a substantially rectangular shape with the seat width direction as the longitudinal direction in a planar cross section. Similarly, the upper guide 36 is formed in a substantially rectangular shape with the seat width direction as the longitudinal direction in a cross section seen from the seat front-rear direction. The belt guide 30 is made of, for example, resin, and the rear guide 32, the bent portion 34, and the upper guide 36 are integrally molded.

[0023] The front end of the upper guide 36 is open at the front surface of the shoulder portion 14D of the seat back 14. The shoulder belt 26A is guided by this belt guide 30 from the upper end of the retractor 28 to the front surface of the seat back 14, passing behind and above the upper frame 18C. The belt guide 30 is not limited to the above-mentioned shape and material. For example, the belt guide 30 may guide the shoulder belt 26A extending from the retractor 28 attached to the vehicle body from the rear surface of the shoulder portion 14D of the seat back 14 to the front surface.

[0024] (Side airbag device 10) Next, a description will be given of the side airbag device 10. As shown in Fig. 1, the side airbag device 10 includes an inflator 38 that generates gas when a side collision of the vehicle is predicted or detected, and a side airbag 40 that receives gas from the inflator 38 and is inflated and deployed between the side of the vehicle body (not shown) and the occupant P.

[0025] The inflator 38 is a cylinder-type gas generating device formed in a substantially cylindrical shape, and is disposed on the outer side of the outer side frame 18A in the vehicle width direction with its axis direction aligned with the outer side frame 18A. As an example, the inflator 38 is disposed at a height near the abdomen B of the occupant P. Although not shown in the figures, a pair of upper and lower stud bolts protrude from the outer periphery of the inflator 38 toward the inside in the vehicle width direction. The inflator 38 is fastened to the outer side frame 18A by inserting the stud bolts into the outer side frame 18A and tightening them with nuts. The inflator 38 is also provided with a gas ejection portion (not shown), and gas is generated from the gas ejection portion when a side collision of the vehicle is predicted or detected.

[0026] As shown in FIG. 3, when gas is supplied from the gas ejection portion of the inflator 38, the side airbag 40 breaks the seat back skin 22 by the inflation pressure and is deployed to the outside (right side) in the vehicle width direction with respect to the occupant P. The side airbag 40 is formed in an elongated shape with the height direction of the seat back 14 as the longitudinal direction, and is formed to a size capable of restraining the head H to the abdomen B of the occupant P. Specifically, the side airbag 40 includes an upper chamber 42 that is inflated and deployed to the outside (right side) in the vehicle width direction with respect to the head H of the occupant P, and a lower chamber 44 that is inflated and deployed to the outside (right side) in the vehicle width direction with respect to the shoulder S including the chest C to the abdomen B of the occupant P. The side airbag 40 is configured as an integrated bag body in which the upper chamber 42 and the lower chamber 44 are communicated with each other, and is formed by overlapping two pieces of base fabric formed by cutting out a nylon-based or polyester-based fabric material, for example, and sewing the outer peripheral edge portions. The manufacturing method of the side airbag 40 is not limited to the above and can be modified as appropriate.

[0027] As shown in FIG. 1, the side airbag 40 is stored in a folded state from the outer side portion 14A of the seat back 14 to the upper portion 14C of the seat back 14. Specifically, the side airbag 40 is stored in such a manner that the lower chamber 44 runs along the outer side of the outer side frame 18A to the upper side of the upper frame 18C, and the upper chamber 42 passes through the lower side of the belt guide 30, the inner side (left side) of the belt guide 30 in the width direction, and the upper side of the belt guide 30 in this order, and is wrapped around the belt guide 30 on the upper side of the upper frame 18C. In other words, the upper chamber 42 is arranged along the lower side, inner side, and upper side of the belt guide 30 in a state where it is folded in a direction that is approximately U-shaped with the outer side in the vehicle width direction being open when viewed from the front. In this upper chamber 42, the inner portion 42A arranged on the inner side (left side) of the belt guide 30 in the width direction is stored between the headrest 16 and the belt guide 30. The folding method of the lower chamber 44 is not particularly limited, and various folding methods can be adopted.

[0028] (Actions and Effects of the Present Embodiment) Next, the operation and effects of this embodiment will be described.

[0029] 1 to 3, according to the vehicle side airbag device 10 of this embodiment, the upper body of an occupant P is restrained to the seat back 14 of the vehicle seat 12 by the shoulder belt 26A. When a side collision of the vehicle is predicted or detected, gas is generated from an inflator 38 (see FIG. 1) provided on an outer side portion 14A of the seat back 14. This gas is supplied to an upper chamber 42 and a lower chamber 44 of the side airbag 40, respectively.

[0030] 3, the upper chamber 42 inflated by the supply of gas is deployed outward in the vehicle width direction (to the right) relative to the head H of the occupant P. On the other hand, the lower chamber 44 inflated by the supply of gas is deployed outward in the vehicle width direction (to the right) relative to the area from the shoulders S including the chest C to the abdomen B of the occupant P.

[0031] Here, as shown in FIG. 1, the side airbag 40 is stored in a folded state from the outer side portion 14A to the upper portion 14C of the seat back 14, and is disposed in the shoulder portion 14D of the seat back 14, passing below the belt guide 30. That is, the side airbag 40 is disposed in advance passing below the shoulder belt 26A. Furthermore, in the upper chamber 42, the inner portion 42A disposed on the widthwise inner side (left side) of the belt guide 30 is stored between the head restraint 16 and the belt guide 30. As a result, the upper chamber 42 is deployed earlier on the seat widthwise inner side (left side) than the belt guide 30. Therefore, the upper chamber 42 is deployed earlier on the seat widthwise inner side (left side) than the right shoulder S of the occupant P restrained by the shoulder belt 26A, that is, near the head H of the occupant P.

[0032] [Supplementary explanation of the above embodiment] In the above embodiment, the vehicle seat 12 has been described as a driver's seat in a right-hand drive vehicle or a passenger seat in a left-hand drive vehicle, which is located on the right side of the vehicle interior, but is not limited thereto and may be located on the left side of the vehicle interior. When the vehicle seat 12 is located on the left side of the vehicle interior, the configuration is symmetrical to that of this embodiment. Also, the vehicle seat 12 may be located at the rear of the vehicle interior as a rear seat.

[0033] In addition, in the above embodiment, the lower chamber 44 is described as being deployed outward in the vehicle width direction relative to the shoulders S, including the chest C, and the abdomen B of the occupant P, but this is not limited thereto, and the lower chamber may be inflated and deployed outward in the vehicle width direction relative to at least one of the waist W and chest C of the occupant P.

[0034] In this embodiment, the upper chamber 42 is described as being stored in a manner that wraps around the belt guide 30. As a reference example that is not an embodiment of the present invention, For example, the structure of the first modified example shown in Figures 4 and 5 or the second modified example shown in Figures 6 and 7 may be adopted. In the following description, the same components as those in this embodiment are denoted by the same reference numerals and the description thereof will be omitted as appropriate.

[0035] (First Modification) As shown in Figures 4 and 5, a vehicle side airbag device 60 according to a first modified example is mounted on a vehicle seat 62 in which a seat back 64 and a headrest 66 are integrally molded. The seat back 64 includes a seat back frame 18. The headrest 66 includes a headrest stay 68 which is a framework member. The vehicle seat 62 includes a pad (not shown) attached to the seat back frame 18 and the headrest stay 68, and a skin (not shown) covering the pad.

[0036] The headrest stay 68 includes an outer leg 68A extending vertically on the outer side (right side) in the vehicle width direction, an inner leg 68B extending vertically on the inner side (left side) in the vehicle width direction, and a connecting portion 68C connecting upper ends of the outer leg 68A and the inner leg 68B in the seat width direction. The outer leg 68A and the inner leg 68B of the headrest stay 68 are each attached to an upper frame 18C of the seatback frame 18. The headrest stay 68 may be molded integrally with the seatback frame 18.

[0037] The belt guide 30 is disposed at a shoulder portion 64B on the outer side in the vehicle width direction of the seat back 64. The shoulder portion 64B of the seat back 64 is located at an upper end portion of a side portion 64A (hereinafter referred to as an "outer side portion 64A") on the outer side in the vehicle width direction of the seat back 64.

[0038] The vehicle side airbag device 60 according to this modified example includes an inflator 38 and a side airbag 72. The side airbag 72 includes an upper chamber 74 that is inflated and deployed outward in the vehicle width direction (right side) relative to the head H of the occupant P, and a lower chamber 76 that is inflated and deployed outward in the vehicle width direction (right side) relative to the shoulders S including the chest C to the abdomen B of the occupant P.

[0039] Here, the upper chamber 74 is stored in a state where it is bent into a substantially L-shape when viewed from the front. Specifically, the upper chamber 74 includes an outer portion 74A that is disposed in the shoulder portion 64B of the seat back 64, below the belt guide 30 and along the upper side of the upper frame 18C, and extends in the seat width direction, and an inner portion 74B that is disposed along the outer side (right side) of the outer leg portion 68A in the vehicle width direction and extends in the vertical direction.

[0040] According to the vehicle side airbag device 60 of this modified example, the upper chamber 74 of the side airbag 72 is disposed in advance below the shoulder belt 26A. Furthermore, in the upper chamber 74, at least the inner portion 74B is stored between the outer leg portion 68A of the headrest stay 68 and the belt guide 30. As a result, the upper chamber 74 is deployed early on inward in the seat width direction from the belt guide 30, i.e., near the head H of the occupant P.

[0041] In addition, since the inner portion 74B of the upper chamber 74 is disposed along the outer side (right side) of the outer leg portion 68A in the seat width direction, the side airbag 72 does not need to be disposed above the belt guide 30. This makes it possible to reduce the thickness of the shoulder portion 64B in the vertical direction, thereby improving the external design of the vehicle seat 62.

[0042] (Second Modification) Next, a second modified example will be described with reference to Figures 6 and 7. In the following description, the same components as those in the first modified example will be given the same reference numerals and the description thereof will be omitted as appropriate.

[0043] 6 and 7, a vehicle side airbag device 90 according to the second modified example is mounted on a vehicle seat 92 in which a seat back 64 and a headrest 66 are integrally formed. Note that the vehicle side airbag device 90 according to this modified example may be mounted on a seat back 14 provided separately from the headrest 16, as in the vehicle seat 12.

[0044] A vehicle side airbag device 90 according to this modified example includes an inflator 38 and a side airbag 94. The side airbag 94 includes an upper chamber 96 that is inflated and deployed outward in the vehicle width direction (right side) relative to the head H of the occupant P, and a lower chamber 98 that is inflated and deployed outward in the vehicle width direction (right side) relative to the shoulders S including the chest C to the abdomen B of the occupant P.

[0045] Here, the upper chamber 96 is stored in a state where it is folded into a substantially S-shape when viewed from the front. Specifically, the upper chamber 96 includes an outer portion 96A that is disposed along the upper side of the upper frame 18C, passing under the belt guide 30, at the shoulder portion 64B of the seat back 64, and extends in the seat width direction, and an inner portion 96B that is disposed between the belt guide 30 and the outer leg portion 68A and folded into a substantially S-shape when viewed from the front. The inner portion 96B is not limited to a bellows shape including a substantially S-shape when viewed from the front, and may be folded into, for example, a spiral shape.

[0046] According to the vehicle side airbag device 90 of this modified example, the upper chamber 96 of the side airbag 94 is disposed below the shoulder belt 26A in advance. Furthermore, in the upper chamber 96, at least the inner portion 96B is stored between the outer leg portion 68A and the belt guide 30. As a result, the upper chamber 74 is deployed early on inward in the seat width direction from the belt guide 30, i.e., near the head H of the occupant P.

[0047] In addition, by disposing the inner portion 96B of the upper chamber 96 between the belt guide 30 and the outer leg portion 68A, it is possible to reduce the vertical thickness of the shoulder portion 64B while reducing the dimension of the headrest 66 in the seat width direction. Therefore, the external design of the vehicle seat 92 can be further improved. [Explanation of symbols]

[0048] 10, 60, 90 Vehicle side airbag device 12, 62, 92 Vehicle seats 14, 64 Seat back 14A, 64A Outer side part (outer side part of the seat back in the vehicle width direction) 14C Top of seat back 14D, 64B Seat back shoulder area 16, 66 Headrest 26A Shoulder Belt 30 Belt guide 38 Inflator 40, 72, 94 Side airbags 42, 74, 96 Upper chamber 42A, 74B, 96B Inner part (at least a part of the upper chamber) 44, 76, 98 Lower chamber C Chest H head P Crew W waist

Claims

[Claim 1] an inflator provided on an outer side in a vehicle width direction of a seat back that supports a back of a seated occupant in a vehicle seat, the inflator generating gas when a side collision of the vehicle is predicted or detected; a side airbag comprising an upper chamber which is supplied with gas from the inflator and which is inflated and deployed outward in the vehicle width direction against the head of the seated occupant, and a lower chamber which is supplied with gas from the inflator and which is inflated and deployed outward in the vehicle width direction against at least one of the waist and chest of the seated occupant, the side airbag being stored in a folded state from the side portion of the seat back to the upper portion of the seat back, and being disposed in the shoulder portion of the seat back, passing below a belt guide through which a shoulder belt which restrains the upper body of the seated occupant is inserted, with a part of the upper chamber being stored between a headrest which supports the head of the seated occupant in the vehicle seat and the belt guide; having The upper chamber is folded so as to be roughly U-shaped with the outer side in the vehicle width direction open when viewed from the front side of the vehicle seat, and is arranged along the lower side, inner side in the vehicle width direction, and upper side in the vehicle vertical direction of the belt guide.

Images