Vehicle seat equipped with a side airbag device

Abstract

To inhibit delay in expansion and deployment of a head chamber to a space between a shoulder belt and an occupant head.SOLUTION: A vehicle seat 10 includes: a seat body 12 in which an occupant P is restrained by a three point seat belt 32; and a side airbag which is stored folded along an area extending from an outer side part 16R as seen in a vehicle width direction to an upper end 16U through a top of a shoulder part 16S in a seat back 16 and in which a head chamber and a body chamber are expanded and deployed by a gas being supplied from an inflator. A lower tear seam TS1 which receives an expansion pressure of the body chamber to cleave is set on a surface cover 24 of the seat back 16 at the side part 16R. An upper tear seam TS2 which receives an expansion pressure of the head chamber to cleave is set on the surface cover 24 at the upper end 16U. The upper tear seam TS2 is configured to cleave more easily than the lower tear seam TS1.SELECTED DRAWING: Figure 6

Description

[Technical field]

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

[0002] In the safety device for a vehicle seat disclosed in the following Patent Document 1, the backrest of the vehicle seat has at least one lateral region and an upper region from which the headrest extends. A side airbag device including at least one inflator and a side airbag is mounted on the backrest. The side airbag has a thorax section and a head section, and a gas generator (inflator) is housed in the thorax section. When the inflator is activated, the thorax section inflates and deploys from the side region of the backrest, and the head section inflates and deploys from the upper region of the backrest next to the headrest. The head section and the thorax section are formed of separate bags and are connected via a tubular filling section or the like. As a result, the head section is configured to inflate and deploy shifted toward the inside in the vehicle width direction (i.e., toward the occupant's head) relative to the thorax section. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] U.S. Patent No. 8,469,395 Summary of the Invention [Problem to be solved by the invention]

[0004] In the above prior art, the head section inflates and deploys between the shoulder belt of the seat belt and the head of the occupant, so that the head can be restrained early by the head section. However, due to the structure in which the inflator is housed in the torso chamber, the head chamber inflates with a delay after the torso chamber inflates. Since the initial inflation pressure (internal pressure) of the head chamber is lower than the initial inflation pressure of the torso chamber, there is a delay in the tearing of the seat back skin in the inflation region of the head chamber. As a result, it is considered that the inflation and deployment of the head chamber may be delayed.

[0005] In consideration of the above, an object of the present invention is to provide a vehicle seat equipped with a side airbag device that can suppress delay in the inflation and deployment of the head chamber between the shoulder belt and the occupant's head. [Means for solving the problem]

[0006] A vehicle seat equipped with a side airbag device of the first aspect comprises a seat body in which an occupant is restrained using a three-point seat belt, an inflator that generates gas when a side collision of the vehicle is detected or predicted, and a side airbag that is stored in a folded state from the side portion of the seat back of the seat body on the outer side of the vehicle width direction through the shoulder and along the upper end portion, wherein a torso chamber to which gas is supplied from the inflator inflates and deploys from the side portion between the occupant's torso and the side of the vehicle body, and a head chamber to which gas is supplied via the torso chamber inflates and deploys from the upper end portion between the occupant's head and the shoulder belt of the seat belt, and a lower tear seam that tears when subjected to the inflation pressure of the torso chamber is set in the skin of the seat back at the side portion, and an upper tear seam that tears when subjected to the inflation pressure of the head chamber is set in the skin at the upper end portion, and the upper tear seam is configured to tear more easily than the lower tear seam.

[0007] In the first embodiment, an occupant is restrained to the seat body using a three-point seat belt. When a side collision of the vehicle is detected or predicted, gas is generated from an inflator and supplied to a side airbag. The side airbag is stored in a folded state along an upper end portion of the seat back of the seat body, from a side portion on the outer side in the vehicle width direction through the shoulder. The torso chamber of the side airbag is supplied with gas from the inflator, and inflates and deploys from a side portion of the seat back between the torso of the occupant and the side portion of the vehicle body. The head chamber of the side airbag is supplied with gas via the torso chamber, and inflates and deploys from the upper end portion of the seat back between the occupant's head and the shoulder belt of the seat belt.

[0008] In this embodiment, a lower tear seam that tears under the inflation pressure of the torso chamber is set in the seat back skin at the side of the seat back, and an upper tear seam that tears under the inflation pressure of the head chamber is set in the seat back skin at the upper end of the seat back. The upper tear seam is configured to tear more easily than the lower tear seam. This allows the upper tear seam to tear early due to the inflation pressure of the head chamber, thereby suppressing delays in inflation and deployment of the head chamber between the shoulder belt and the occupant's head.

[0009] In the vehicle seat equipped with the side airbag device of the second aspect, in the first aspect, the upper tear seam is sewn with a weaker thread or with a larger sewing pitch than the lower tear seam.

[0010] In the second aspect, because the upper tear seam is configured as described above, the upper tear seam can be made easier to tear than the lower tear seam with a simple configuration.

[0011] A vehicle seat equipped with a side airbag device of the third aspect, in the first or second aspect, includes a lower force cloth that connects the lower tear seam to the side frame of the seat back and transmits the inflation pressure of the torso chamber to the lower tear seam, and an upper force cloth that connects the upper tear seam to the upper frame of the seat back and transmits the inflation pressure of the head chamber to the upper tear seam.

[0012] In a third embodiment, a lower tear seam of the seat back skin is connected to the seat back side frame by a lower webbing, and an upper tear seam of the seat back skin is connected to the seat back upper frame by an upper webbing. The lower webbing transmits the inflation pressure of the torso chamber to the seat back skin, and the upper webbing transmits the inflation pressure of the head chamber to the seat back skin. By adding these webbing, the inflation pressure of the torso chamber and the head chamber can be concentrated to the lower tear seam and the upper tear seam, allowing each tear seam to tear early.

[0013] A vehicle seat equipped with a side airbag device of a fourth aspect is the third aspect, in which the upper webbing is configured to be less stretchable than the lower webbing.

[0014] In the fourth aspect, since the upper webbing is configured to be less stretchable than the lower webbing, the inflation pressure of the head chamber can be effectively transmitted to the seat back skin via the upper webbing, and the seat back skin can be quickly torn apart, thereby enabling the head chamber to be inflated and deployed earlier. Effect of the Invention

[0015] As described above, in a vehicle seat equipped with a side airbag device according to the present invention, delay in inflation and deployment of the head chamber between the shoulder belt and the head of an occupant can be suppressed. [Brief description of the drawings]

[0016] [Figure 1]FIG. 2 is a front view showing a state in which the side airbag in the vehicle seat according to the embodiment has been fully inflated and deployed. [Diagram 2] FIG. 2 is a side view showing a state in which the side airbag in the vehicle seat according to the embodiment has been fully inflated and deployed. [Diagram 3] FIG. 2 is a planar development view of the side airbag. [Figure 4] 4 is an enlarged cross-sectional view showing a cut surface taken along line F4-F4 in FIG. 3. [Diagram 5] FIG. 2 is a front view showing the vehicle seat according to the embodiment, showing a see-through state of the inside of the seat back. [Figure 6] 1 is a front view showing a vehicle seat according to an embodiment; [Figure 7] FIG. 6 is an enlarged cross-sectional view showing a cut surface along line F7-F7 in FIG. 5. [Figure 8] FIG. 8 is an enlarged cross-sectional view corresponding to FIG. 7, illustrating a state in the middle of inflating and deploying the side airbag. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] <First embodiment> A vehicle seat 10 (hereinafter, simply referred to as "vehicle seat 10") equipped with a side airbag device according to an embodiment of the present invention will be described below with reference to Figs. 1 to 8. Note that an arrow FR shown as appropriate in each drawing indicates the front of the vehicle, an arrow UP indicates the upper side of the vehicle, and an arrow LH (OUT) indicates the left side of the vehicle (outside in the vehicle width direction). Hereinafter, when the directions of front-rear, left-right, and up-down are used in the description, they refer to front-rear in the vehicle front-rear direction, left-right in the vehicle left-right direction (vehicle width direction), and up-down in the vehicle up-down direction, unless otherwise specified. Also, in each drawing, some symbols may be omitted in order to make the drawings easier to read.

[0018] As shown in Fig. 1 and Fig. 2, a vehicle seat 10 according to this embodiment includes a seat body 12 in which an occupant is restrained using a three-point seat belt (webbing) 32, and a side airbag device 40. As an example, this vehicle seat 10 is the driver's seat of a right-hand drive vehicle or the passenger seat of 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 10 coincide with the front-rear direction, left-right direction (width direction), and up-down direction of the vehicle. When this vehicle seat 10 is disposed on the left side of the vehicle interior, it has a left-right symmetrical configuration to this embodiment.

[0019] The seat body 12 has a seat cushion 14 that supports the buttocks and thighs of an occupant P seated on the seat body 12, a seat back 16 that is connected to the rear end of the seat cushion 14 and supports the back of the occupant P, and a headrest 18 that is connected to the upper end of the seat back 16 and supports the head H of the occupant P.

[0020] In Fig. 1 and Fig. 2, a crash test dummy P is seated in the seat body 12 instead of an actual occupant. This dummy P is, for example, AM50 (50th percentile of adult American males) of the World Side Impact Dummy (WorldSID). This dummy P is seated in the seat body 12 in a seating manner prescribed by the side impact test method. The front-rear position of this seat body 12 with respect to the vehicle and the inclination angle of the seat back 16 with respect to the seat cushion 14 are adjusted to standard setting positions corresponding to the above-mentioned seating manner. In this state, the front-rear, left-right, up-down directions of the seat back 16 coincide with the front-rear, left-right, up-down directions of the vehicle.

[0021] The seat back 16 includes a seat back frame 20 (see Figs. 5, 7, and 8) which is a skeletal member, a seat back pad 22 (see Figs. 7 and 8) which is placed on the seat back frame 20, and a seat back skin 24 (see Figs. 1, 2, 5 to 8) which covers the seat back pad 22. The seat back frame 20 is made of, for example, metal or resin, and includes a pair of left and right side frames 20A as shown in Fig. 5, and an upper frame 20B which connects the upper ends of the left and right side frames 20A in the left-right direction of the seat back 16. The seat back pad 22 is made of, for example, a foam such as urethane foam. The seat back skin 24 is made by sewing together a plurality of skin pieces made of, for example, a cloth material (woven fabric), a knit material (knitted fabric), synthetic leather, leather, etc. The seat back skin 24 corresponds to the "skin" in the present invention.

[0022] The seat belt 32 that restrains the occupant P to the seat body 12 constitutes a main part of the vehicle seat belt device 30. As shown in Fig. 1, one longitudinal end of the seat belt 32 is fixed to an anchor plate 34 that is fixed to the vehicle floor or the like on the outer side (right side in this case) of the seat body 12 in the vehicle width direction. The other end (not shown) of the seat belt 32 is fixed to a winding shaft of a retractor (not shown) disposed on the lower part of the B pillar of the vehicle or the like. An intermediate part (not shown) of the seat belt 32 is inserted into a shoulder anchor (not shown) disposed on the upper part of the B pillar or the like and folded back.

[0023] A tongue plate 36 is slidably attached to a portion of the seat belt 32 between the shoulder anchor and the anchor plate 34. The tongue plate 36 is connected to a buckle device 38 attached to the lower end of the seat body 12, etc., on the inner side (here, the left side) of the seat body 12 in the vehicle width direction. This brings the occupant P into a state in which the seat belt 32 is fastened. In this seat belt fastening state, the chest and abdomen of the occupant P are restrained by a shoulder belt 32A, which is a portion of the seat belt 32 between the shoulder anchor and the tongue plate 36. In addition, in this seat belt fastening state, the waist of the occupant P is restrained by a lap belt 32B, which is a portion of the seat belt 32 between the tongue plate 36 and the anchor plate 34.

[0024] An inflator 44 (see FIG. 2), which is a component of the side airbag device 40, is disposed on the side portion 16R on the outer side in the vehicle width direction of the seat back 16. A side airbag 42, which is a component of the side airbag device 40, is disposed on a portion extending from the side portion 16R on the outer side in the vehicle width direction of the seat back 16 through the shoulder 16S to the upper end portion 16U. As shown in FIG. 3 and FIG. 4, the side airbag 42 is formed into a bag shape by overlapping two base fabrics BC1 and BC2 formed by cutting out a nylon or polyester cloth material, for example, and sewing the outer peripheral edge portions at a sewing portion S1. The manufacturing method of the side airbag 42 is not limited to the above and can be appropriately changed. For example, the side airbag 42 may be manufactured by folding one base fabric in half and sewing the outer peripheral edge portions. For example, the side airbag 42 may be manufactured by a hollow weaving method (so-called OPW method) using an automatic loom.

[0025] The side airbag 42 is configured as a single bag body and has a long bag shape. One end side in the longitudinal direction of the side airbag 42 is a head chamber 42A that restrains the head H of the occupant P, and the other end side in the longitudinal direction of the side airbag 42 is a torso chamber 42B that restrains the torso B (here, from the chest to the waist) of the occupant P. A duct-shaped narrowed portion (duct portion) 42C is formed between the head chamber 42A and the torso chamber 42B. The side airbag 42 is narrowed at the narrowed portion 42C.

[0026] An inflator connection portion 42D extends from one long side edge of the side airbag 42. An inflator 44 is connected to the inflator connection portion 42D. The inflator 44 is a so-called cylinder-type inflator and is formed in a cylindrical shape. As shown in Fig. 2, the inflator 44 is disposed in a side portion on the outer side in the vehicle width direction of the seatback 16 with its axial direction aligned along the height direction of the seatback 16, i.e., inclined downward toward the front, and is fixed to a side frame 20A on the outer side in the vehicle width direction of the seatback frame 20.

[0027] A gas ejection portion is provided at the lower end of the inflator 44, and an inflator connection portion 42D of the side airbag 42 is connected to the ejection portion. A side impact ECU 46 mounted on the vehicle is electrically connected to the inflator 44 as shown in Fig. 2. A side impact sensor 48 that detects a side impact is electrically connected to the side impact ECU 46. The side impact ECU 46 is configured to activate the inflator 44 when it detects a side impact (or the inevitability of a side impact) based on a signal from the side impact sensor 48.

[0028] When the inflator 44 is activated, gas is ejected from the ejection portion of the inflator 44 into the torso chamber 42B. The gas supplied into the torso chamber 42B is also supplied to the head chamber 42A through the narrowed portion 42C, thereby inflating and deploying the side airbag 42. If a collision prediction sensor (pre-crash sensor) that predicts (predicts) a side collision is electrically connected to the side collision ECU 46, the inflator 44 may be activated when the side collision ECU 46 predicts a side collision based on a signal from the collision prediction sensor.

[0029] 5, the side airbag 42 is normally stored in a folded state from the side portion 16R on the outer side in the vehicle width direction of the seatback 16 through the shoulder 16S along the upper end portion 16U. In the side airbag 42 in this folded state, the torso chamber 42B is disposed at the side portion 16R of the seatback 16, the constricted portion 42C is disposed at the shoulder 16S of the seatback 16, and the head chamber 42A is disposed at the upper end portion 16U of the seatback 16. The head chamber 42A is stored at the upper end portion 16U of the seatback 16, extending to the vicinity of the headrest support 19 on the outer side in the vehicle width direction. In addition, the constricted portion 42C is stored in a bent state along the shoulder 16S of the seatback 16.

[0030] As shown in Fig. 6, a tear seam TS is set in the seat back skin 24 from the side portion 16R on the outer side in the vehicle width direction of the seat back 16 through the shoulder 16S to the upper end portion 16U. This tear seam TS is composed of a lower tear seam TS1 and an upper tear seam TS2. The lower tear seam TS1 extends in the height direction of the seat back 16 at the side portion 16R of the seat back 16. The upper tear seam TS extends in the approximately left-right direction of the seat back 16 at the upper end portion 16U of the seat back 16. The boundary between the lower tear seam TS1 and the upper tear seam TS2 is set at the shoulder 16S of the seat back 16.

[0031] 7, at the upper tear seam TS2, two skin pieces 24A, 24B that constitute a part of the seatback skin 24 are sewn together. The skin piece 24A constitutes the upper surface of the upper end portion 16U of the seatback 16, and the skin piece 24B constitutes the upper part of the front surface of the side portion 16R of the seatback 16. Although not shown in cross section, at the lower tear seam TS1, multiple skin pieces that constitute a part of the seatback skin 24 are sewn together.

[0032] The lower tear seam TS1 tears open when it receives the expansion pressure of the torso chamber 42B, and the upper tear seam TS2 tears open when it receives the expansion pressure of the head chamber 42A. The thread used to sew the upper tear seam TS2 is weaker than the thread used to sew the lower tear seam TS1 (e.g., a thread with a larger count or a thread made of a weaker material). This makes the upper tear seam TS2 more likely to tear open than the lower tear seam TS1. Note that the upper tear seam TS2 and the lower tear seam TS1 may have different sewing pitches (stitch pitches) instead of the above-mentioned configuration in which the thread strength (thickness, etc.) is different between the upper tear seam TS2 and the lower tear seam TS1. If the sewing pitch of the upper tear seam TS2 is set larger than the sewing pitch of the lower tear seam TS1, the upper tear seam TS2 can be made more likely to tear open than the lower tear seam TS1.

[0033] 5, two lower webbing cloths 50, 52 are arranged side by side in the height direction of the seat back 16 on the side portion 16R of the seat back 16. An upper webbing cloth 54 is arranged on the upper end portion 16L of the seat back 16. The lower webbing cloths 50, 52 and the upper webbing cloth 54 are made of a fabric material that is less stretchable than the material of the seat back skin 24.

[0034] The lower webbing 50, 52 connects the side frame 20A on the outer side of the seatback frame 20 in the vehicle width direction to the lower tear seam TS1. These lower webbing 50, 52 are loop-shaped when viewed from the height direction of the seatback 16 so as to surround the torso chamber 42B stored in the side portion 16R of the seatback 16. These lower webbing 50, 52 transmit the inflation pressure of the torso chamber 42B to the lower tear seam TS1 of the seatback skin 24, causing the lower tear seam TS1 to tear. These lower webbing 50, 52 are conventionally known and therefore will not be described in detail.

[0035] As shown in Fig. 7, the upper webbing 54 connects the upper frame 20B of the seatback frame 20 to the upper tear seam TS2. The upper webbing 54 is loop-shaped when viewed from the left and right direction of the seatback 16 so as to surround the head chamber 42A stored in the upper end 16U of the seatback 16. Specifically, the upper webbing 54 is composed of a front upper webbing 54A located on the front side of the seatback 16 with respect to the head chamber 42A in the stored state, and a rear upper webbing 54B located on the upper and rear sides of the seatback 16 with respect to the head chamber 42A in the stored state. One end of each of the front upper webbing 54A and the rear upper webbing 54B is sewn together with the upper tear seam TS2.

[0036] The front upper webbing 54A is inserted through a slit 56 formed in the seat back pad 22 on the front side of the head chamber 42A, and the other end is overlapped on the front surface of the upper frame 20B. The rear upper webbing 54B is inserted through a slit 58 formed in the seat back pad 22 on the rear side of the head chamber 42A, and the other end is overlapped on the rear surface of the upper frame 20B. The other ends of the front upper webbing 54A and the rear upper webbing 54B are fastened and fixed to the upper frame 20B using bolts 60 and 62, for example. Note that the method of fixing the other ends of the front upper webbing 54A and the rear upper webbing 54B to the upper frame 20B is not limited to the above and can be changed as appropriate. For example, a plate-shaped member may be attached to the other ends of the front upper webbing 54A and the rear upper webbing 54B, and the plate-shaped members may be fixed to the upper frame 20B using bolts or the like.

[0037] 8, the upper force cloth 54 transmits the inflation pressure of the head chamber 42A to the upper tear seam TS2 of the seat back cover 24, causing the upper tear seam TS2 to tear. In this embodiment, the fabric material constituting the upper force cloth 54 (i.e., the front upper force cloth 54A and the rear upper force cloth 54B) is configured to be less stretchable than the fabric material constituting the lower force cloths 50, 52.

[0038] In the vehicle seat 10 having the above configuration, when the inflator 44 is activated and the side airbag 42 begins to inflate, the lower tear seam TS1 and the upper tear seam TS2 of the seatback skin 24 are torn by the inflation pressure of the torso chamber 42B and the head chamber 42A. This causes the side airbag 42 to inflate and deploy between the occupant P and the side of the vehicle body (not shown). In this case, gas from the inflator 44 is supplied to the torso chamber 42B through the inflator connection portion 42D, and gas from the inflator 44 is supplied to the head chamber 42A through the torso chamber 42B and the constricted portion 42C. Therefore, the head chamber 42A inflates and deploys later than the torso chamber 42B. The inflation pressure of the head chamber 42A is lower than the inflation pressure of the torso chamber 42B. The tear seams TS are torn in the following order: the lower side of the lower tear seam TS1 → the upper side of the lower tear seam TS1 → the upper tear seam TS2.

[0039] As shown in Figs. 1 and 2, the torso chamber 42B inflates and deploys from the side 16R of the seat back 16 between the torso B of the occupant P and the side of the vehicle body (not shown). The torso chamber 42B faces the chest, abdomen and waist of the occupant P in contact with or in close proximity to the outside in the vehicle width direction. The head chamber 42A inflates and deploys from the upper end 16U of the seat back 16 between the head H of the occupant P and the shoulder belt 32A of the seat belt 32. The head chamber 42A is disposed adjacent to the headrest 18 on the outside and front side of the vehicle width direction, and faces the head H of the occupant P in contact with or in close proximity to the outside in the vehicle width direction. Although not shown, a duct (inner tube) that distributes gas from the inflator 44 into the torso chamber 42B and the head chamber 42A may be disposed inside the side airbag 42.

[0040] <Action and Effects> Next, the operation and effects of this embodiment will be described.

[0041] In the vehicle seat 10 having the above-mentioned configuration, the occupant P is restrained to the seat body 12 by using a three-point seat belt 32. When a side collision of the vehicle is detected or predicted, gas is generated from the inflator 44 and supplied to the side airbag 42. The side airbag 42 is stored in a folded state along an upper end 16U of the seat back 16 of the seat body 12 from a side portion 16R on the outer side in the vehicle width direction through a shoulder 16S. The torso chamber 42B of the side airbag 42 is supplied with gas from the inflator 44, and inflates and deploys from the side portion 16R of the seat back 16 between the torso B of the occupant P and the side of the vehicle body. The head chamber 42A of the side airbag 42 is supplied with gas via the torso chamber 42B, and inflates and deploys from the upper end 16U of the seat back 16 between the head H of the occupant P and the shoulder belt 32A of the seat belt 32. Since this side airbag 42 is configured from a single bag body, the configuration can be simplified compared to a case in which the head chamber 42A and the torso chamber 42B are configured from separate bags.

[0042] Moreover, in this embodiment, the seatback skin 24 at the side portion 16R of the seatback 16 is provided with a lower tear seam TS1 that tears open under the inflation pressure of the torso chamber 42B. In addition, the seatback skin 42 at the upper end portion 16U of the seatback 16 is provided with an upper tear seam TS2 that tears open under the inflation pressure of the head chamber 42A. The upper tear seam TS2 is configured to tear open more easily than the lower tear seam TS1. As a result, even if the inflation pressure of the head chamber 42A is configured to be lower than the inflation pressure of the torso chamber 42B, the upper tear seam TS2 can be ripped open early by the inflation pressure of the head chamber 42A, so that delay in the inflation and deployment of the head chamber 42A between the shoulder belt 32A and the head H of the occupant P can be suppressed. As a result, the deployment behavior of the head chamber 42A between the shoulder belt 32A and the head H of the occupant P can be stabilized.

[0043] Furthermore, in this embodiment, the upper tear seam TS2 is sewn with a weaker thread than the lower tear seam TS1. This allows the upper tear seam TS2 to be more easily torn apart than the lower tear seam TS1 with a simple configuration. This effect can be obtained even when the sewing pitch of the upper tear seam TS2 is set larger than the sewing pitch of the lower tear seam TS1.

[0044] Furthermore, in this embodiment, the seat back skin 24 and the side frame 20A are connected by the lower webbing 50, 52 at the side portion 16R of the seat back 16, and the seat back skin 24 and the upper frame 20B are connected by the upper webbing 54 at the upper end portion 16U of the seat back 16. The lower webbing 50, 52 transmit the inflation pressure of the torso chamber 42B to the lower tear seam TS1 of the seat back skin 24, causing the lower tear seam TS1 to tear. The upper webbing 54 transmits the inflation pressure of the head chamber 42A to the upper tear seam TS2 of the seat back skin 24, causing the upper tear seam TS2 to tear. The addition of this upper webbing 54 can more effectively suppress delays in the inflation and deployment of the head chamber 42A between the shoulder belt 32A and the head H of the occupant P.

[0045] In this embodiment, one end of each of the front upper webbing 54A and the rear upper webbing 54B constituting the upper webbing 54 is sewn together with the upper tear seam TS2, and the other end of each of the front upper webbing 54A and the rear upper webbing 54B is fixed to the upper frame 20B. This allows the inflation pressure of the head chamber 42A to be concentrated on the upper tear seam TS2 with a simple configuration, allowing the upper tear seam TS2 to rupture early.

[0046] In this embodiment, the head chamber 42A stored in the upper end portion 16U of the seat back 16 is surrounded by an upper webbing 54 that is loop-shaped when viewed from the left-right direction of the seat back 16. As a result, the inflation and deployment of the head chamber 42A is guided by the loop-shaped upper webbing 54, so that the deployment behavior of the head chamber 42A between the shoulder belt 32A and the head H of the occupant P can be further stabilized.

[0047] In this embodiment, the upper webbing 54 is configured to be less stretchable than the lower webbing 50, 52. This allows the inflation pressure of the head chamber 42A to be effectively transmitted to the upper tear seam TS2 of the seat back skin 24 via the upper webbing 54, accelerating the rupture of the upper tear seam TS2. As a result, the head chamber 42A can be inflated and deployed earlier.

[0048] In the above embodiment, the upper webbing 54 is configured to include the lower webbing 50, 52, but this is not limited to the above, and any or all of the upper webbing 54 and the lower webbing 50, 52 may be omitted.

[0049] In addition, in the above embodiment, the upper webbing 54 is configured to be less stretchy than the lower webbing 50, 52, but this is not limited to the above, and the upper webbing 54 and the lower webbing 50, 52 may be configured to be equally difficult to stretch.

[0050] In the above embodiment, the upper webbing 54 includes the front upper webbing 54A and the rear upper webbing 54B, but the present invention is not limited to this. For example, the upper webbing 54 may include only the front upper webbing 54A.

[0051] In the above embodiment, the other end portions of the front upper webbing 54A and the rear upper webbing 54B are fixed to the upper frame 20B, but the present invention is not limited to this. For example, the other end portion of the rear upper webbing 54B may be fixed (sewn) to the seat back skin 24 on the rear surface side of the seat back 16.

[0052] In addition, in the above embodiment, the torso chamber 42B of the side airbag 42 is configured to be large enough to restrain the occupant P from the chest to the waist, but this is not limited to the above and the size of the torso chamber 42B can be changed as appropriate.

[0053] In addition, the present invention can be implemented in various modifications without departing from the spirit and scope of the present invention. Furthermore, the scope of the present invention is not limited to the above-described embodiment. [Explanation of symbols]

[0054] 10. Vehicle seat equipped with a side airbag device 12 Seat body 16 Seat back 16R Side 16S Shoulder 16U top end 24 Seat back skin (skin) 32 Three-point seat belt 32A Shoulder Belt 42 Side airbag 42A Head chamber 42B Body chamber 44 Inflator 50, 52 Downward force cloth 54 Upper force cloth TS1 Top tear seam TS2 Lower tear seam P Crew H head B. Torso

Claims

1. A seat body in which an occupant is restrained using a three-point seat belt; an inflator that generates gas when a side collision of the vehicle is detected or predicted; a side airbag that is stored in a folded state along an upper end portion of a seat back of the seat body from a side portion on an outer side in a vehicle width direction through a shoulder, a torso chamber to which gas is supplied from the inflator inflates and deploys from the side portion between the torso of the occupant and a vehicle body side portion, and a head chamber to which gas is supplied via the torso chamber inflates and deploys from the upper end portion between the head of the occupant and a shoulder belt of the seat belt; Equipped with A lower tear seam that tears when subjected to the inflation pressure of the torso chamber is provided in the seat back skin at the side portion, An upper tear seam is provided in the skin at the upper end, the upper tear seam being ruptured by the inflation pressure of the head chamber, A vehicle seat equipped with a side airbag device, wherein the upper tear seam is configured to be more easily torn than the lower tear seam.

2. 2. The vehicle seat equipped with a side airbag device according to claim 1, wherein the upper tear seam is sewn with a weaker thread or with a larger sewing pitch than the lower tear seam.

3. a lower webbing that connects the lower tear seam and a side frame of the seat back and transmits the inflation pressure of the torso chamber to the lower tear seam; an upper webbing that connects the upper tear seam and an upper frame of the seat back and transmits the inflation pressure of the head chamber to the upper tear seam; 3. A vehicle seat equipped with the side airbag device according to claim 1 or 2.

4. 4. The vehicle seat equipped with a side airbag device according to claim 3, wherein the upper webbing is configured to be less stretchable than the lower webbing.

Images