Vehicle seat

Abstract

To reduce tensile force applied to a pad side part in a vehicle seat, especially when the seat is tilted in a front-back direction.SOLUTION: A vehicle seat (S) includes: a lower seat back frame (FA) having vertically extending left and right lower back side frames (2A); an upper seat back frame (FB) mounted on the upper part of the lower seat back frame tiltably to a rotary shaft (X) extending to the left and right between a backward tilting position extending in almost the same direction as the lower seat back frame, and a forward tilting position forward tilting to the backward tilting position; a pad body part (30) arranged along the front faces of the lower seat back frame and the upper seat back frame; a pad (P) including left and right pad side parts (31) extending backward along the left and right outside surfaces of the lower seat back frame and the upper seat back frame from left and right both ends of the pad body part; and a skin (SK) covered on the pad. A groove (32) extending almost parallel to the rotary shaft is provided in a rear face (35) of the pad body part.SELECTED DRAWING: Figure 7

Description

[Technical field]

[0001] The present invention relates to a vehicle seat, and more particularly to a vehicle seat in which an upper part of a seat back is vertically divided and can be tilted in the front-rear direction relative to a lower part of the seat back. [Background technology]

[0002] In vehicle seats, the pad and the cover are integrally formed, and the pad is less likely to tilt in the front-rear direction when the upper part of the seat back is tilted, compared to a seat in which the pad and the cover are separated into upper and lower parts. In order to solve this problem, Patent Document 1 discloses a seat in which a through hole is provided in the front surface of the pad, which extends in the left-right direction, and which penetrates the pad in the front-rear direction in the center of the left-right direction, thereby separating the pad into upper and lower parts and improving flexibility. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] 5-74396 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the configuration disclosed in the above-mentioned Patent Document 1, since the through-hole penetrates the pad in the front-rear direction, the pad needs to be supported by the left and right side portions of the pad located on the left and right outer sides of the upper seatback frame. This requires the pad sides to have a relatively large thickness, which causes a problem that a relatively large tension is applied to the pad sides, especially when the upper part of the seatback is tilted.

[0005] SUMMARY OF THEINVENTION In view of the above problems, an object of the present invention is to reduce the tension applied to the side portions of a pad in a vehicle seat, particularly when the seat is tilted in the front-rear direction. [Means for solving the problem]

[0006] In order to solve this problem, one aspect of the present invention provides a vehicle seat (S) including: a lower seatback frame (FA) having a pair of left and right lower backside frames (2A) extending in the up-down direction; an upper seatback frame (FB) attached to an upper part of the lower backside frame so as to be tiltable between a rearward tilt position extending in substantially the same direction as the lower seatback frame and a forward tilt position inclined forward with respect to the rearward tilt position, about a rotation axis (X) extending in the left-right direction; a pad (P) including a pad main body portion (30) arranged along the front surface of the lower seatback frame and the upper seatback frame, and left and right pad side portions (31) extending rearward from both left and right ends of the pad main body portion along the left and right outer side surfaces of the lower seatback frame and the upper seatback frame; and a cover (SK) covered on the pad, wherein a groove (32) extending substantially parallel to the rotation axis is provided on at least the rear surface of the pad main body portion.

[0007] According to this aspect, a groove extending in the left-right direction is provided on the rear surface of the pad main body, so that when the upper seat back tilts in the front-rear direction relative to the lower seat back, the pad main body deforms in the groove, which allows the pad main body to support a relatively large stress and makes it possible to reduce the thickness of the pad side portions, thereby reducing the tension applied to the pad side portions when the seat tilts in the front-rear direction.

[0008] In the above configuration, the groove may be provided at a position corresponding to the front and rear of the rotation shaft.

[0009] With this configuration, the heights of the groove and the pivot axis are approximately the same, thereby improving the flexibility of the pad in the fore-and-aft direction when the upper seat back tilts in the fore-and-aft direction relative to the lower seat back.

[0010] In addition, in the above configuration, the groove preferably reaches the boundary between the pad main body and the left and right pad side portions, extends forward and backward on the inner surfaces of the left and right pad side portions, and reaches the rear ends of the left and right pad side portions.

[0011] According to this configuration, the end of the groove reaches the rear end of the side of the pad, improving the flexibility of the side of the pad, thereby further reducing the tension applied to the side of the pad when the upper seat back tilts in the front-rear direction relative to the lower seat back.

[0012] In addition, in the above configuration, the groove may include a front groove provided on the front surface of the pad main body, and a rear groove provided on the rear surface of the pad main body at a position corresponding to the front and rear of the front groove.

[0013] According to this configuration, the pad body can be deformed more satisfactorily in the groove, and the flexibility of the pad in the front-rear direction is further improved.

[0014] Furthermore, in the above configuration, the front grooves reach the outer surfaces of the left and right pad side portions, extend front-to-rear on the outer surfaces of the left and right pad side portions, and reach the rear ends of the left and right pad side portions, and the rear grooves reach the boundary between the pad main body and the left and right pad side portions, extend front-to-rear on the inner surfaces of the left and right pad side portions, and reach the rear ends of the left and right pad side portions.

[0015] According to this configuration, the flexibility of the pad side portions is further improved, and the tension applied to the pad side portions when the upper seat back tilts in the front-rear direction relative to the lower seat back can be further reduced.

[0016] Furthermore, in the above configuration, it is preferable that the vehicle seat further includes an upper member extending left and right and connected to the left and right upper back side frames, a lower member extending left and right and connected to the left and right lower back side frames, a plurality of wires extending up and down and connected to the upper member and the lower member, and a lumbar support (37) supported by the wires, and an upper end of the lumbar support is positioned below a lower end of the groove.

[0017] According to this configuration, since the lumbar support is disposed below the groove, when the upper seat back tilts in the front-rear direction relative to the lower seat back, the pad main body can tilt without receiving resistance from the lumbar support, thereby further improving the flexibility of the pad.

[0018] Furthermore, in the above configuration, the skin has a skin main body portion (38) covering the front surface of the pad main body portion and the outer surfaces of the left and right side portions of the pad, a bag-shaped portion (39) provided on the upper part of the skin main body portion, formed in a bag shape and placed over the upper end portion of the pad, and left and right first extension portions (40) extending inwardly to the left and right from the left and right side edges of the skin main body portion, and the left and right first extension portions are preferably connected to each other and positioned above the pivot axis.

[0019] According to this configuration, by joining the left and right first extension parts with an appropriate strength and pulling the skin inward to the left and right, wrinkles and sagging of the skin can be reduced. Also, because the left and right first extension parts are disposed above the pivot axis, when the upper part of the seat tilts in the front-rear direction relative to the lower part of the seat, the pad main body can tilt without receiving resistance from the left and right first extension parts.

[0020] In addition, in the above configuration, the skin may further have left and right second extension portions (41) extending inwardly to the left and right from the left and right side edges of the skin main body portion, and the left and right second extension portions may be connected to each other and positioned below the pivot axis.

[0021] According to this configuration, by joining the left and right second extension parts with an appropriate strength and pulling the upholstery inwardly to the left and right, it is possible to further prevent wrinkles and sagging of the upholstery. In particular, since the left and right second extension parts are disposed below the pivot shaft, the tension applied to the left and right second extension parts is kept substantially constant when the upper part of the seat tilts in the front-rear direction relative to the lower part of the seat, so that the upholstery can be pulled stably.

[0022] In the above configuration, at least one of the first extension portion and the second extension portion may be connected to each other by a hook-and-loop fastener (42).

[0023] According to this configuration, the joining position of the left and right extensions in the left-right direction can be adjusted according to the degree of wrinkles or sagging of the epidermis, making it easier to keep the extensions in a taut state, thereby further preventing wrinkles and sagging of the epidermis. Effect of the Invention

[0024] According to the present invention, in a vehicle seat, it is possible to reduce the tension applied to the side portions of the pad when the seat is tilted in the front-rear direction. [Brief description of the drawings]

[0025] [Figure 1] FIG. 1 is a front perspective view of a vehicle seat according to the present invention; [Diagram 2] FIG. 1 is a perspective view of a vehicle seat according to the present invention, seen from the rear; [Diagram 3] A perspective view of a seat back frame [Figure 4] FIG. 4 is a cross-sectional view of the seat back frame taken along line IV-IV in FIG. 2 when the upper seat back frame is in a rearward tilting position. [Diagram 5] FIG. 4 is a cross-sectional view of the seat back frame taken along line IV-IV in FIG. 2 when the upper seat back frame is in a forward tilting position. [Figure 6] A perspective view of the seat back with the backboard removed from the rear [Figure 7] 7 is a cross-sectional view of a seat back taken along line VII-VII in FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0026] Hereinafter, an embodiment in which a vehicle seat S according to the present invention is installed in an automobile will be described with reference to the drawings. In the following description, left and right are defined based on an occupant seated in the vehicle seat S. Furthermore, a pair of components that are installed symmetrically on the left and right may be given the same number and the description thereof may be omitted.

[0027] As shown in Figures 1 and 2, the vehicle seat S has a slider S4 engaged with a rail (not shown) that is provided on the floor of the automobile so as to extend in the front-to-rear direction, a seat cushion S1 that is disposed above the slider S4 and forms a seat surface whose surface faces approximately vertically, a seat back S2 that extends upward from the rear of the seat cushion S1 and forms a backrest surface whose surface faces approximately forward-to-rear, and a headrest S3 that is provided on the upper part of the seat back S2 so as to be slidable up and down.

[0028] The seat cushion S1 is constructed by covering a seat cushion frame (not shown) with a pad P and a skin SK (see FIG. 4). The front and side parts of the seat back S2 are constructed by covering a seat back frame F (see FIG. 3) with the pad P and the skin SK, and the rear part of the seat back S2 is constructed by covering the seat back frame F with a backboard B. The headrest S3 is constructed by covering a headrest frame (not shown) with the pad P and the skin SK.

[0029] The seat back S2 has a lower seat back S2A that is tiltable forward and backward with respect to the seat cushion S1 via the reclining mechanism 1, and an upper seat back S2B that is tiltable forward and backward with respect to the lower seat back S2A. A headrest S3 is provided on the upper part of the upper seat back S2B.

[0030] The backboard B is composed of a backboard lower part BA and a backboard upper part BB. The backboard lower part BA covers the lower seat back S2A, and the backboard upper part BB covers the upper seat back S2B. The backboard lower part BA is formed in a substantially flat plate shape. On the other hand, the backboard upper part BB has a substantially semicircular arc-shaped flat board main body part provided so as to be continuous with the backboard lower part BA, and a substantially semicylindrical board side part formed integrally with the board main body part so as to extend forward from both side edges and the upper edge of the board main body part. The backboard B is formed from a synthetic resin or the like.

[0031] Although not shown, the seat cushion frame has a pair of left and right cushion side frames extending in the front-rear direction, a front frame suspended between the front portions of the cushion side frames, a rear frame suspended between the rear portions of the cushion side frames, etc., which are formed into a frame shape. The slider S4 is attached to each of the cushion side frames.

[0032] As shown in FIG. 3, the seat back frame F has a pair of left and right back side frames 2, 3 extending generally vertically, a back lower frame 4 connected between the lower ends of the back side frames 2, 3 and extending generally horizontally, and an inverted U-shaped back upper frame 5 connected between the upper portions of the back side frames 2, 3, which are formed into a frame shape.

[0033] The back side frames 2, 3 are composed of three sheet metal members (plate-shaped members) divided in the vertical direction. The lowest sheet metal member and the intermediate sheet metal member are joined to each other by welding or the like to constitute a pair of lower back side frames 2A, 3A. The uppermost sheet metal member constitutes a pair of upper back side frames 2B, 3B that are attached to the upper parts of the lower back side frames 2A, 3A so as to be tiltable about a rotation axis X along the horizontal direction. The back lower frame 4 is joined to the lower back side frames 2A, 3A by welding, for example, and the back upper frame 5 is joined to the upper back side frames 2B, 3B by welding, for example. The back lower frame 4 and the lower back side frames 2A, 3A constitute a lower seat back frame FA, and the upper back side frames 2B, 3B and the back upper frame 5 constitute an upper seat back frame FB.

[0034] The front and rear edges of the lower back side frames 2A and 3A are formed with front ribs 6 and rear ribs 7 that are bent inwardly to the left and right and have surfaces that face approximately front and rear. Similarly, the front and rear edges of the upper back side frames 2B and 3B are formed with front ribs 6 and rear ribs 7 that are bent inwardly to the left and right and have surfaces that face approximately front and rear. The upper back side frames 2B and 3B are arranged so as to overlap the lower back side frames 2A and 3A on the inside in the left and right direction of the lower back side frames 2A and 3A. The overlapping portions of the upper back side frames 2B and 3B and the lower back side frames 2A and 3A are pin-connected by the shaft members 22, so that the upper back side frames 2B and 3B can tilt in the front and rear direction around the rotation axis X relative to the lower back side frames 2A and 3A.

[0035] A first board attachment part 8 made of a U-shaped steel bar is fixed to the middle part in the height direction of the lower back side frames 2A, 3A so as to protrude inwardly to the left and right from the rear rib 7. Near the upper end part of the lower back side frames 2A, 3A (the upper end of the rear rib 7), the rear rib 7 protrudes inwardly to the left and right more than other parts, forming a backboard support part 10. A second board attachment part 9 made of a U-shaped steel bar is fixed to the inner end part in the left and right direction of the backboard support part 10 so as to protrude inwardly to the left and right. The first board attachment part 8 and the second board attachment part 9 are used to attach the backboard lower part BA to the lower seat back frame FA, and the backboard support part 10 supports the backboard lower part BA.

[0036] Near the lower end of the upper back side frames 2B, 3B, the rear rib 7 protrudes inwardly to the left and right as compared with other portions, forming a third board mounting portion 11 for mounting the backboard upper portion BB to the upper seat back frame FB. A pair of headrest holding portions 12 for supporting the headrest S3 are joined to the upper portion extending to the left and right of the back upper frame 5. A plate-shaped reinforcing frame 13 is hung so as to extend in the left and right direction between the left and right pillar portions extending substantially vertically of the back upper frame 5. A through hole 13a for fixing the backboard upper portion BB is formed in the reinforcing frame 13, and the reinforcing frame 13 also functions as a board fixing portion for fixing the backboard upper portion BB.

[0037] A motor 15 is attached to the lower part of the inner surface of the right lower back side frame 3A for driving the reclining mechanism 1 (FIG. 1) to change the tilt angle of the right lower back side frame 3A relative to the cushion side frame. In other words, the reclining mechanism 1 is an electric mechanism that receives the rotational force of the motor 15 to change the tilt angle of the lower back side frame 3A relative to the cushion side frame and maintains it at a desired position. Various known mechanisms can be applied to such a reclining mechanism 1, and detailed explanations will be omitted here.

[0038] An actuator 17 for tilting and driving the right upper back side frame 3B via a link mechanism 16 is attached to the lower inner surface side of the right lower back side frame 3A. The actuator 17 includes an electric motor 18, a reduction mechanism connected to the output shaft of the electric motor 18, and a conversion mechanism such as a feed screw or a ball screw for converting the rotational motion of the reduction mechanism into linear motion, and its output part 17a moves linearly, and various known mechanisms can be applied. The actuator 17 is fixed to the inner surface of the lower back side frame 3A by a bolt or the like so that the output part 17a is oriented to extend along the lower back side frame 3A.

[0039] On the other hand, an airbag 19 is attached to the lower inner surface of the left lower backside frames 2A, 3A to protect the sides of a seated occupant in the event of a vehicle collision.

[0040] When the actuator 17 is driven, the upper backside frames 2B, 3B tilt in the front-rear direction relative to the lower backside frames 2A, 3A. FIG. 4 shows the inner surface of the right backside frame 3 when the upper backside frame 3B is in the most rearward tilted position. Hereinafter, this position will be referred to as the rearward tilted position. In the rearward tilted position, the upper backside frame 3B extends in substantially the same direction as the lower backside frame 3A. FIG. 5 shows the inner surface of the right backside frame 3 when the upper backside frame 3B is in the most forward tilted position. Hereinafter, this position will be referred to as the forward tilted position. Normally, the lower backside frame 3A and the upper backside frame 3B are rearward tilted with respect to the vertical line, but hereinafter, unless otherwise specified, the positional relationship (upper-lower relationship and front-rear relationship) of the members and the like will be described assuming that the extension direction of these members is vertical and that the upper backside frame 3B is in the rearward tilted position.

[0041] Next, the pad P, lumbar support 37, and cover SK will be described with reference to Fig. 6 and Fig. 7. Fig. 6 shows the seat back S2 from the rear side with the backboard B removed. The pad P has a pad main body 30 whose main surface faces substantially in the front-rear direction, and left and right pad side parts 31 extending rearward from both the left and right ends of the pad main body 30, and is disposed in front of the seat back frame F. The pad P is formed from a resilient cushioning material such as polyurethane foam, with a reference position being midway between the backward tilt position and the forward tilt position.

[0042] The pad main body 30 extends vertically from slightly below the back lower frame 4 beyond the back upper frame 5, and also extends horizontally from the left and right inner surfaces of the right back side frame 3 to the left and right inner surfaces of the left back side frame 2. The front surface of the pad main body 30 faces approximately in the front-rear direction near the center in the left-right direction, and bulges forward outward to the left and right near the left and right ends.

[0043] The pad side portions 31 extend rearward from the left-right ends of the pad main body 30 along the left and right outer side surfaces of the back side frames 2, 3. The rear ends of the left and right pad side portions 31 are located rearward of the rear ends of the back side frames 2, 3. Therefore, the back side frames 2, 3 are located between the pad main body 30 and the pad side portions 31.

[0044] A groove 32 extending substantially parallel to the pivot axis X is provided on the rear surface of the pad main body 30. As shown in FIG. 7, in this embodiment, a first rear groove 33 extending substantially parallel to the pivot axis X is provided on the rear surface of the pad main body 30. The left and right ends of the first rear groove 33 reach the inner surfaces of the pad side portions 31. Second rear grooves 34 extending rearward from the ends of the first rear groove 33 are provided on the inner surfaces of the left and right pad side portions 31, and the rear ends of the second rear grooves 34 reach the rear surfaces of the pad side portions 31. A first front groove 35 extending substantially parallel to the pivot axis X is provided on the front surface of the pad main body 30. The left and right ends of the first front groove 35 reach the outer surfaces of the pad side portions 31. A second front groove 36 is provided on the outer surface of each of the left and right pad side portions 31, extending rearward from the end of the first front groove 35, and the rear end of the second front groove 36 reaches the rear surface of the pad side portion 31.

[0045] It is preferable that the first rear groove 33, the first front groove 35, and the pivot axis X are disposed so as to generally correspond to each other in the front-rear direction. That is, in the rearward tilt position, it is preferable that the heights of the first rear groove 33, the first front groove 35, and the pivot axis X are generally the same and disposed on the transverse cross section of the pad main body 30. Similarly, it is preferable that the left and right second rear grooves 34 and the left and right second front grooves 36 are disposed so as to generally correspond to each other in the left-right direction.

[0046] The pad main body 30 does not include a portion where the first rear groove 33 and the first front groove 35 are connected in the front-rear direction and penetrate the pad main body 30 in the front-rear direction. Moreover, the pad side portion 31 does not include a portion where the second rear groove 34 and the second front groove 36 are connected in the left-right direction and penetrate the pad side portion 31 in the left-right direction.

[0047] Returning to Fig. 6, the explanation will be continued. A lumbar support 37 is disposed in the center in the left-right direction of the lower seatback frame FA. The lumbar support 37 has an upper member joined to the upper backside frames 2B, 3B and a lower member joined to the lower backside frames 2A, 3A, and has a function of supporting the lower back of a seated occupant.

[0048] The skin SK includes a skin main body 38 whose main surface faces the front-rear direction, and a bag-shaped portion 39 extending from an upper portion of the skin main body 38 and formed into a bag shape. The skin main body 38 is placed so as to cover the front surface of the pad main body 30 and the outer surface of the pad side portion 31 from the outside of the pad P and the lumbar support 37. The bag-shaped portion 39 is placed so as to cover the upper end portion of the pad main body 30 from the outside of the pad P. The skin SK is formed from real leather, synthetic leather, cloth, or the like, with the midpoint between the backward tilt position and the forward tilt position as the reference position.

[0049] A first extension 40 extends from the rear side edge of the skin main body 38, extending inwardly to the left and right. A hook-and-loop fastener 42 consisting of a male fastener and a female fastener is provided at the tip of the first extension 40, and the first extension 40 is formed into a strip shape having a predetermined width by overlapping and joining the male fastener and the female fastener. The lower end of the first extension 40 is disposed above the rotation axis X in the rearward tilt position. In this embodiment, the first extension 40 is provided at a portion that corresponds approximately to the reinforcement frame 13 in the front-rear direction, and the lower end of the first extension 40 is disposed above the first rear groove 33, the first front groove 35, and the rotation axis X in the rearward tilt position. In addition, the first extension 40 is preferably disposed so that the third board attachment portion 11 is exposed from the rear when the backboard B is removed from the seat back S2. In this embodiment, the lower end of the first extension portion 40 is disposed higher than the upper end of the third board attachment portion 11 .

[0050] Below the first extension 40, a second extension 41 having a predetermined width extends inwardly from the rear side edge of the skin main body 38. The second extension 41 is formed in a band shape by wrapping a pair of left and right strips in a closed loop and connecting them to each other with a fastener 43 in a fastened state. The upper end of the second extension 41 is disposed below the rotation axis X in the rearward tilt position. In this embodiment, the second extension 41 is provided in a portion that corresponds approximately to the middle portion of the lower seat back frame FA in the vertical direction in the front-rear direction, and the upper end of the second extension 41 is disposed below the first rear groove 33, the first front groove 35, and the rotation axis X in the rearward tilt position. In addition, the second extension 41 is preferably disposed so that the second board mounting portion 9 is exposed when the backboard B is removed from the seat back S2. In this embodiment, the second extension 41 has an opening formed in a portion corresponding to the second board mounting portion 9.

[0051] Next, the operation and function of the vehicle seat S according to this embodiment will be described. The upper seat back S2B tilts between a rearward tilt position and a forward tilt position. When the upper seat back S2B is in the rearward tilt position, the pad P and the upper part of the upholstery SK are bent downward toward the rear. As a result, as shown in FIG. 4, the end of the first rear groove 33 on the rear surface of the pad main body 30 and the end of the second rear groove 34 on the inner surface of the pad side portion 31 are contracted and deformed in a substantially vertical direction. In addition, the end of the first front groove 35 on the front surface of the pad main body 30 and the end of the second front groove 36 on the outer surface of the pad side portion 31 are expanded and deformed in a substantially vertical direction. In particular, the deformation of the groove 32 is relatively large near the boundary between the pad main body 30 and the pad side portion 31.

[0052] When the upper seat back S2B is in the rearward tilting position, as shown in Fig. 5, the pad main body 30 and the upper part of the skin main body 38 are bent downward toward the front. As a result, the end of the first front groove 35 on the front surface of the pad main body 30 and the end of the second front groove 36 on the outer surface of the pad side portion 31 are contracted and deformed in the approximately vertical direction. Also, the end of the first rear groove 33 on the rear surface of the pad main body 30 and the end of the second rear groove 34 on the inner surface of the pad side portion 31 are expanded and deformed in the approximately vertical direction. Similarly, the deformation of the groove 32 is relatively large near the boundary between the pad main body 30 and the pad side portion 31.

[0053] As described above, the groove 32 provided in the pad main body 30 is deformed, so that the pad main body 30 can bend easily and can support a relatively large stress in the pad main body 30, thereby reducing the tension applied to the pad side portion 31 when the upper seat back S2B tilts in the front-rear direction. In this embodiment, the groove 32 includes a first front groove 35 provided on the front surface of the pad main body 30 and a first rear groove 33 provided at a position corresponding to the front and rear of the first front groove 35 on the rear surface of the pad main body 30. This makes it easier for the pad main body 30 to bend even when the upper seat back S2B tilts in either the front-rear direction or the rear-rear direction. Furthermore, since the first rear groove 33 and the first front groove 35 are provided at a position corresponding to the rotation axis X in the front and rear directions, the first rear groove 33 and the first front groove 35 are easily deformed in response to the tilt of the upper seat back S2B. This makes it easier for the pad main body 30 to bend.

[0054] Moreover, the groove 32 further includes a second rear groove 34 and a second front groove 36. As a result, when the upper seat back S2B tilts in the front-rear direction and the pad main body 30 bends, the pad side portion 31 deforms in the second rear groove 34 and the second front groove 36, so that the tension applied to the pad side portion 31 can be reduced.

[0055] In addition, the first rear groove 33 and the first front groove 35 do not communicate in the front-rear direction with the pad body 30. This allows the pad P to support a relatively large stress in the pad body 30, and the thickness of the pad side portion 31 can be made relatively thin, thereby reducing the tension applied to the pad side portion 31.

[0056] In addition, the pad P and the skin SK of this embodiment are formed with a reference position being midway between the backward tilt position and the forward tilt position. Therefore, the tension applied to the pad P and the skin SK is distributed approximately evenly when the upper seat back S2B is in the backward tilt position and when it is in the forward tilt position, and the tension is prevented from being concentrated on the pad P and the skin SK when it is in either one of the positions.

[0057] In this embodiment, the upper end of the lumbar support 37 is disposed lower than the first rear groove 33, the first front groove 35, and the lower end of the rotation axis X. This allows the pad main body 30 to bend without receiving resistance from the lumbar support 37 when the upper seat back S2B tilts in the front-rear direction, making it even easier for the pad main body 30 to bend.

[0058] Furthermore, in this embodiment, the skin main body 38 has left and right first extensions 40, and the left and right first extensions 40 are connected to each other. As a result, the upper part of the skin SK can be pulled inwardly to the left and right, reducing wrinkles and sagging of the skin SK and improving the aesthetics of the skin SK. In addition, the first extensions 40 are offset upward with respect to the first rear groove 33, the first front groove 35, and the rotation axis X. As a result, when the upper seat back S2B tilts in the front-rear direction, the skin SK is not contracted or expanded in the up-down direction at the first extensions 40, and the first extensions 40 are less likely to deform, further reducing wrinkles and sagging of the skin SK. In addition, the first extensions 40 are connected to each other with hook-and-loop fasteners 42. This allows the worker, when assembling the vehicle seat S, to adjust the joining position in the left-right direction between the first extension portions 40 according to the degree of wrinkles or sagging of the upholstery SK, making it easier to keep the first extension portions 40 in a taut state, further preventing wrinkles and sagging of the upholstery SK.

[0059] Moreover, the skin main body 38 has left and right second extensions 41, which are connected to each other below the first rear groove 33, the first front groove 35, and the pivot axis X. This allows the lower part of the skin SK in particular to be pulled inwardly to the left and right, thereby reducing wrinkles and sagging of the skin SK and further improving the aesthetics of the skin SK. Also, when the upper seat back S2B tilts in the front-rear direction, the skin SK does not shrink or expand in the up-down direction at the second extensions 41, and is less likely to deform at the second extensions 41, thereby further reducing wrinkles and sagging of the skin SK.

[0060] Although the description of the specific embodiment is finished above, the present invention can be widely modified and implemented without being limited to the above embodiment. For example, in the above embodiment, the vehicle seat S of the present invention is installed in an automobile as an example, but the vehicle seat S of the present invention may be installed in a railway car or an airplane, or may be widely applied to furniture or office chairs. In addition, the specific configuration, arrangement, quantity, angle, etc. of each member or part can be appropriately changed within a range that does not deviate from the gist of the present invention. On the other hand, all of the components shown in the above embodiment are not necessarily required, and can be appropriately selected. [Explanation of symbols]

[0061] 2: Back side frame 2A: Lower back side frame 2B: Upper back side frame 3: Back side frame 3A: Lower back side frame 3B: Upper back side frame 30: Pad body 31: Pad side 32: Groove 33: First rear gutter 34: Second rear gutter 35: First front drain 36: Second front drain 37: Lumbar support 38: Epidermis body part 39: Pouch-shaped part 40: 1st extension 41:Second extension part 42: Velcro F: Seat back frame FA: Lower seat back frame FB: Upper seat back frame P: Pad S: Vehicle seat S2: Seat back S2A: Lower seat back S2B: Upper seat back SK: epidermis X: Rotation axis

Claims

1. A seat back frame; A pad covering the seat back frame; a skin covering the pad; the seatback frame includes an upper seatback frame mounted to be tiltable about a rotation axis extending in the left-right direction between a rearward tilt position and a forward tilt position tilted forward relative to the rearward tilt position, the upper seat back frame includes a pair of left and right upper back side frames attached so as to be tiltable in the front-rear direction about the pivot shaft, and a back upper frame coupled to each of the pair of left and right upper back side frames, A front rib is formed on each front edge of the pair of left and right upper back side frames, protruding inward to the left and right and facing forward and backward, The pad is provided with a groove extending in the left-right direction, The groove is disposed forward of the front rib.

2. A rear rib is formed on each rear edge of the pair of left and right upper back side frames, protruding inward to the left and right and with a surface facing forward and backward, Each of the pair of left and right upper back side frames has a region where the front rib and the rear rib are inclined relative to each other, The vehicle seat of claim 1 , wherein the groove is disposed forward of the region.

3. A rear rib is formed on each rear edge of the pair of left and right upper back side frames, protruding inward to the left and right and with a surface facing forward and backward, the back upper frame has a region between the front rib and the rear rib, The vehicle seat according to claim 1 , wherein the groove is disposed so as to be located in front of the region when the upper seat back frame is in the forward tilt position.

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