Vehicle seat

Abstract

In a vehicle seat, a side frame (38) of a seatback frame (25) has: a front wall (38b) which is formed so as to be continuous from the front edge of a plate-shaped section (38a) and bent inward, and which forms a bent region (41) which extends in the vertical direction from a rotation axis and reaches an upper frame (39), and a rear wall (38c) which is formed so as to extend in the vertical direction from the rotation axis and which is bent inward from the front edge of the plate-shaped section (38a); the front wall (38b) has a plate-shaped portion (38a) and a rear wall (38c) which is continuously formed from the rear edge of the plate-shaped portion (38a) and is bent inward to form a bent region (42) extending in the vertical direction from the periphery of the rotating shaft and reaching the upper frame (39), and the inner edge of the front wall (38b) has a protruding piece (69) which spreads inward from an imaginary contour line (68) corresponding to the shape of the upper frame (39) and overlaps the front wall (54) of the upper frame (39) from the rear. Accordingly, a vehicle seat capable of contributing to improving work efficiency when the seat back frame is assembled is provided.

Description

This application is a divisional application of the invention patent application with application number 202080060924.4. The international application date of the original application is August 27, 2020, the priority date is August 28, 2019, the date of entering the Chinese national stage is February 28, 2022, and the invention name of the original application is “Vehicle Seat”. Technical Field

[0001] The present invention relates to a vehicle seat, which has a seat back frame, wherein the seat back frame has: left and right side frames, which have a plate-like portion, which is spread around a rotation axis along a vertical plane orthogonal to the rotation axis and extends upward along the vertical plane; and an upper frame, which connects the left and right side frames above the rotation axis. Background Art

[0002] Patent document 1 discloses a vehicle seat having a seat back connected to a seat cushion in a manner that allows the backrest angle to be freely adjusted. In the seat, the seat back has left and right side frames that extend upward in the vertical direction from a rotation axis and support the seat back cushion; and an upper frame that connects the left and right side frames above the rotation axis of the backrest angle adjustment mechanism. In addition, the front wall and the rear wall of the side frame cover the entire vertical direction on the end of the upper frame. Prior art literature Patent Literature

[0003] Patent Document 1: Japanese Patent Publication No. 2018-162033 Patent Document 2: Japanese Patent Grant No. 5691769 Patent Document 3: Japanese Patent Publication No. 2013-67240 Summary of the invention

[0004] <Technical Issue No. 1> In the vehicle seat described in the above-mentioned patent document 1, the left and right side frames are structured to clamp the upper frame from both sides. When assembling the upper frame, the left end of the upper frame is inserted into the left frame, and the right end of the upper frame is inserted into the right frame. Therefore, the assembly operation is cumbersome, and it is desired to improve the work efficiency.

[0005] A first object of the present invention is to provide a vehicle seat that can contribute to improved work efficiency when assembling a seat back frame.

[0006] <Technical Issue No. 2> In addition, in a vehicle seat device, for example, according to Patent Document 2, a portion of a side frame of a seat back frame is thickened in order to locally make the required strength of the side frame of the seat back frame different, wherein the vehicle seat device has a seat cushion frame and a seat back frame, and the seat cushion frame and the seat back frame respectively have a pair of side frames arranged at positions separated from each other and extending in a straight line, and a connecting component connecting these side frames.

[0007] In the vehicle seat of Patent Document 2, the side frame in the seat back frame is composed of a side frame main body and a sub-frame, wherein the sub-frame is formed thicker than the side frame main body and is welded to the lower portion of the side frame main body, thereby ensuring the strength of the hinged joint portion where the lower portion of the side frame in the seat back frame is hinged to the seat cushion frame. However, in order to suppress the increase in weight of the side frame while ensuring the required strength, it is desired to change the thickness of the side frame more finely, and in this case, it is desired to avoid affecting the rigidity of the connection portion between the side frame and the connection member connecting the side frame.

[0008] The present invention has been made in view of the above circumstances, and a second object of the present invention is to provide a vehicle seat device that can avoid affecting the rigidity of the connection portion with the connection member while ensuring the strength of the side frame and achieving weight reduction.

[0009] <Technical Issue No. 3> In addition, in a vehicle seat device, for example, according to patent document 2, a side frame in a seat back frame integrally has a side plate portion and a flange portion connected to the outer edge of the side plate portion to form a cross-section in the shape of the Japanese Katakana character "コ", wherein a seat cushion frame of the vehicle seat device and a seat back frame connected to the seat cushion frame respectively integrally have a side plate portion and a flange portion extending laterally from the outer edge of the side plate portion, and have a pair of side frames arranged at positions separated from each other and extending in a straight line.

[0010] In the vehicle seat of Patent Document 2, the side plate portion and the flange portion of the side frame are formed to have the same plate thickness. To improve the rigidity of such a side frame, the plate thickness can be increased, but this will increase the weight. Therefore, it is desired to increase the rigidity of the side frame while suppressing the weight increase as much as possible.

[0011] The present invention has been made in view of the above circumstances, and a third object of the present invention is to provide a vehicle seat device capable of improving the rigidity of a side frame while suppressing an increase in weight as much as possible.

[0012] <Technical Issue No. 4> In addition, according to patent document 3, a vehicle seat (transportation vehicle seat) is known, which has a seat back frame, and the seat back frame has: left and right side frames, which have a plate-like portion that unfolds around a rotation axis along a vertical plane orthogonal to the rotation axis and extends upward along the vertical plane, and a rear wall that is continuously and inwardly bent from a rear edge of the plate-like portion to form a curved area extending in a vertical direction from around the rotation axis; a lower frame, which has a back area, which is arranged behind the rotation axis, is connected to the rear wall from the rear and connects the left and right side frames to each other; and an upper frame, which connects the left and right side frames to each other above the lower frame.

[0013] The vehicle seat of Patent Document 3 has a seat back connected to a seat cushion in a manner that allows the backrest angle to be freely adjusted, and the seat back frame has: left and right side frames that extend upward in a vertical direction from a rotation axis and support the seat back cushion; a bottom plate (lower frame) that is arranged behind the rotation axis of the backrest angle adjustment mechanism and connects the left and right side frames to each other; and an upper crossbeam (upper frame) that connects the left and right side frames to each other above the bottom plate. In addition, the left and right side frames, the bottom plate, and the upper crossbeam form a square frame structure.

[0014] However, the left and right side frames each have a plate-like portion extending along a vertical plane orthogonal to the rotation axis of the backrest angle adjustment mechanism, and a rear wall which is continuously bent inward from the rear edge of the plate-like portion to form a curved region extending from the rotation axis in the vertical direction and reaching the upper cross member, and when the seat back frame is assembled, the bottom plate is joined to the rear wall of the side frame from the rear. Therefore, the bottom plate is assembled to the side frame from one direction, and therefore, the work efficiency for assembling the bottom plate is good.

[0015] On the other hand, since the two joint areas are in a flat plate shape, the torsional rigidity of the frame structure is not that high. Therefore, when ensuring the torsional rigidity, the joint between the bottom plate and the side frame is required to have a high joint strength, and accordingly, the joint work load increases.

[0016] A fourth object of the present invention is to provide a vehicle seat that helps reduce the work load when assembling a seat back frame.

[0017] <Solution to the first technical problem and its effect> In order to achieve the above-mentioned first purpose, the present invention provides a vehicle seat, which has a seat back frame, and the seat back frame has left and right side frames and an upper frame, wherein the left and right side frames have a plate-like portion, which is unfolded around a rotation axis along a vertical plane orthogonal to the rotation axis and extends upward along the vertical plane; the upper frame connects the left and right side frames above the rotation axis, and the upper frame has a front wall, an upper wall, an upper vertical wall, a lower wall and a lower vertical wall, wherein the front wall is formed by bending a plate material and is divided by an upper ridge and a lower ridge extending in a horizontal direction; the upper wall is continuous from the upper ridge and unfolds rearward; the upper vertical wall is folded upward from the rear end of the upper wall The side frame is characterized in that the side frame has a front wall and a rear wall, wherein the front wall is continuously and inwardly bent from the front edge of the plate-like portion to form a curved area extending from the rotation axis to the vertical direction and reaching the upper frame; the rear wall is continuously and inwardly bent from the rear edge of the plate-like portion to form a curved area extending from the rotation axis to the vertical direction and reaching the upper frame, and the inner edge of the front wall has a protruding piece, which is extended inwardly from an imaginary contour line corresponding to the shape of the upper frame and overlaps with the front wall from the rear. According to the first feature, in the side frame, the rigidity of the plate-like portion is improved by the action of the curved area formed by the front wall and the rear wall, so that the side frame is lightweight and can ensure sufficient rigidity. Furthermore, the upper frame can be assembled from the front onto the left and right side frames arranged at intervals during assembly, and at this time, the front wall of the side frame does not need to interfere with the upper and lower vertical walls of the upper frame located at the rear of the front wall. In this way, the work efficiency can be improved when assembling the upper frame.

[0018] In addition to the first feature, the second feature of the present invention is that the front wall of the upper frame and the protruding piece of the side frame have welding marks. According to the second feature, the upper frame and the side frame are overlapped and welded together, so the rigidity of the seat back frame can be improved.

[0019] In addition to the first or second feature, the present invention has a third feature that the vehicle seat has an upper overlapping piece that is continuous from the rear wall and overlaps the upper vertical wall of the upper frame from the rear. According to the third feature, in addition to the front wall of the side frame, the upper frame also overlaps the rear wall (more specifically, the upper overlapping piece) to increase the support rigidity, and the upper overlapping piece can help increase the rigidity of the seat back frame.

[0020] In addition to the third feature, the fourth feature of the present invention is that the upper vertical wall of the upper frame and the upper overlapping piece of the side frame have welding marks. According to the fourth feature, in addition to the front wall, the upper frame is welded to the side frame at the rear wall, thereby improving the rigidity of the seat back frame.

[0021] In addition to any one of the first to fourth features, the present invention has a fifth feature that the vehicle seat has a lower overlapping piece that is continuous from the rear wall and overlaps the lower vertical wall of the upper frame from the rear. According to the fifth feature, in addition to the front wall of the side frame, the upper frame also overlaps the rear wall (more specifically, the lower overlapping piece) to improve the support rigidity, and the lower overlapping piece can contribute to improving the rigidity of the seat back frame.

[0022] In addition to the fifth feature, the sixth feature of the present invention is that the lower vertical wall of the upper frame and the lower overlapping piece of the side frame have welding marks. According to the sixth feature, the upper frame is welded to the side frame at the rear wall in addition to the front wall, so that the rigidity of the seat back frame can be improved.

[0023] In addition to the sixth feature, the seventh feature of the present invention is that the lower overlapping piece has a lower flange, and the lower flange is bent forward from the lower end of the lower overlapping piece. According to the seventh feature, the rigidity of the side frame and even the upper frame is improved, and the deformation of the seat frame can be suppressed. As a result, the back of the occupant sitting on the vehicle seat can be well supported.

[0024] In addition to the seventh feature, the eighth feature of the present invention is that the upper frame has a flange which is continuous from the lower end of the lower vertical wall at a position corresponding to the lower flange in the horizontal direction and is bent forward. According to the eighth feature, the rigidity of the upper frame and even the side frame can be improved, thereby suppressing the deformation of the seat frame. As a result, the back of the occupant sitting on the vehicle seat can be well supported.

[0025] In addition to the eighth feature, the present invention has a ninth feature that the vehicle seat has a side frame flange that is formed by bending from the inner end of the rear wall and is continuous from the lower flange. According to the ninth feature, the lower flange of the lower overlapping piece is continuous from the side frame flange of the rear wall, thereby improving the rigidity of the lower overlapping piece.

[0026] In addition, in addition to any one of the first to ninth features, the present invention has a tenth feature that the vehicle seat has a first support hole and a second support hole, wherein the first support hole is formed on the upper wall and carries a headrest pillar guide portion that supports the headrest pillar in a manner that it can be freely displaced along the axial direction; the second support hole is formed on the lower wall and carries the headrest pillar guide portion, and support hole flanges that are bent downward are formed on the peripheries of the first support hole and the second support hole, respectively. According to this tenth feature, although the first support hole and the second support hole are formed, the rigidity of the upper and lower walls can be ensured. In addition, since the support hole flanges are all bent downward, when the headrest pillar guide portion is assembled, the headrest pillar guide portion can be well inserted into the first support hole and the second support hole.

[0027] <Solution to the second technical problem and its effect> In order to achieve the above-mentioned second object, the present invention provides a vehicle seat device, which comprises a seat cushion frame (215) and a seat back frame (216), wherein the seat cushion frame (215) and the seat back frame (216) respectively have a pair of side frames (218, 225A, 225B, 225C, 225D) arranged at positions separated from each other and extending in a straight line, and connecting parts (219, 220, 227, 228) connecting these side frames (218, 225A to 225D). 8), characterized in that the side frames (218, 225A~225D) of at least one of the seat cushion frame (215) and the seat back frame (216) are formed into a shape in which the plate thickness changes at a plate thickness dividing line (L3, L4; L1, L2), wherein the plate thickness dividing line (L3, L4; L1, L2) is arranged at a position avoiding the connection part with the connecting parts (219, 220, 227, 228) at multiple locations in the longitudinal direction of the side frames (218, 225A~225D). According to the first feature, thickness boundaries where the thickness changes are set at multiple locations in the longitudinal direction of the side frame of at least one of the seat cushion frame and the seat back frame, and the connecting component is connected to the side frame at a position avoiding the thickness boundaries. Therefore, by changing the thickness of the side frame at multiple thickness boundaries, the required strength of the side frame can be ensured on at least one of the seat cushion frame and the seat back frame, while the weight increase can be suppressed and the rigidity of the connection portion between the side frame and the connecting component can be avoided.

[0028] In addition to the first feature, the second feature of the present invention is that a reinforcing portion (238, 239, 268, 272, 273, 274) is provided at a position of the side frame (225A to 225D) avoiding the plate thickness boundary line (L1, L2), and the reinforcing portion (238, 239, 268, 272, 273, 274) extends in a direction intersecting the length direction of the side frame (225A to 225D) and bulges inward or outward. According to the second feature, a reinforcing portion extending in a direction intersecting the length direction of the side frame is provided at a position on the side frame avoiding the plate thickness boundary line, so that the rigidity of the connection portion between the side frame and the connection member is not affected and the strength of the side frame can be further increased.

[0029] In addition to the first or second feature, the present invention has a third feature that an auxiliary component (263) having a reinforcing function is provided on the side frame (225A) so as to avoid contact with the side frame (225A) at the plate thickness boundary line (L2) and to cross the plate thickness boundary line (L2). According to the third feature, the auxiliary component is provided on the side frame across the plate thickness boundary line so as not to contact the side frame at the plate thickness boundary line, thereby improving the rigidity of the side frame at the plate thickness boundary line.

[0030] In addition to the first feature, the present invention has a fourth feature that a reinforcing portion (237, 267) is provided on the side frame (225A-225C) across the plate thickness boundary line (L1, L2), and the reinforcing portion (237, 267) extends along the length direction of the side frame (225A-225C) and bulges inward or outward. According to the fourth feature, the side frame is provided with a reinforcing portion that crosses the plate thickness boundary line, so that the rigidity of the side frame at the plate thickness boundary line can be improved.

[0031] In addition to any one of the first to fourth features, the present invention has a fifth feature that through holes (240 to 246) for mounting mounting components (234, 251, 256) are formed on the side frames (225A to 225D), and the plate thickness boundaries (L1, L2) are set to avoid the through holes (240 to 246). According to the fifth feature, the plate thickness boundaries are set to avoid the through holes for mounting the mounting parts, so the plate thickness boundaries do not affect the mounting rigidity of the mounting components to the side frames.

[0032] In addition to any one of the first to fifth features, the present invention has a sixth feature that the airbag (251) is installed at a portion of the side frame (225A to 225D) where the plate thickness is the same. According to the sixth feature, since the airbag is installed at a portion of the side frame where the plate thickness is the same, the rigidity of the side frame at the portion where the plate thickness is the same can be increased.

[0033] In addition to the sixth feature, the seventh feature of the present invention is that the reinforcing lining cloth (256) for suppressing the deployment of the airbag (251) is fixed to the portion of the side frames (225A to 225D) where the plate thickness is the same. According to the seventh feature, since the reinforcing lining cloth of the airbag is fixed to the portion of the side frames where the plate thickness is the same, it is possible to suppress the influence on the plate thickness boundary line when the airbag is deployed.

[0034] In addition to any one of the first to seventh features, the present invention has an eighth feature that an auxiliary component (263) capable of bearing a load from an occupant when the occupant is seated is fixed to the side frame (225A) of the seat back frame (216) avoiding the plate thickness boundary line (L2). According to the eighth feature, the auxiliary component capable of bearing a load from an occupant in a seated state is fixed to a position of the seat back frame avoiding the plate thickness boundary line of the side frame, thereby suppressing the load from the auxiliary component from affecting the plate thickness boundary line portion of the side frame.

[0035] In addition to any one of the first to eighth features, the present invention has a ninth feature that a pressure-receiving member (234) that elastically deforms by receiving a load from a seated person is installed at a position of the side frames (225A to 225D) that avoids the plate thickness boundary lines (L1, L2). According to the ninth feature, the pressure-receiving member that elastically deforms by receiving a load from a seated person is installed at a position that avoids the plate thickness boundary lines of the side frames, thereby suppressing the load from the pressure-receiving member from affecting the plate thickness boundary lines of the side frames.

[0036] <Solution to the third technical problem and its effect> In order to achieve the third object, the present invention provides a vehicle seat device, wherein a seat cushion frame (315) and a seat back frame (316) connected to the seat cushion frame (315) respectively have a pair of side frames (318, 325A, 325B, 325C, 325D), the pair of side frames (318, 325A, 325B, 325C, 325D) integrally having side plate portions (318a, 325a) and flange portions (318b, 318c; 325b, 325c, 325d) extending laterally from the outer edges of the side plate portions (318a, 325a), and are arranged at positions separated from each other and extend in a straight line. The first feature is that the seat cushion frame (315) and the seat back frame (316) connected to the seat cushion frame (315) respectively have a pair of side frames (318, 325A, 325B, 325C, 325D), the pair of side frames (318, 325A, 325B, 325C, 325D) integrally having side plate portions (318a, 325a) and flange portions (318b, 318c; 325b, 325c, 325d) extending laterally from the outer edges of the side plate portions (318a, 325a), and are arranged at positions separated from each other and extend in a straight line. The side frames (318, 325A~325D) of at least one of the back frames (316) have a reference thickness (ta2, ta1) in a reference thickness region (A2, A1) and an increased thickness (tb2, tb1) thicker than the reference thickness (ta2, ta1) in an increased thickness region (B2, B1), and are formed by changing the thickness in the reference thickness region (A2, A1) and the increased thickness region (B2, B1), wherein the reference thickness region (A2, A1) includes at least the side plate portion (318a, 325a); and the increased thickness region (B2, B1) includes at least the flange portion (318b, 318c, 325b, 325c, 325d). According to the first feature, by making at least a portion including the flange portion of the side frame of at least one of the seat cushion frame and the seat back frame thicker, the rigidity of the side frame can be improved while suppressing an increase in weight of the side frame as much as possible.

[0037] In addition to the first feature, the second feature of the present invention is that the plate thickness increase area (B2, B1) is set to include a predetermined portion, which is a portion of the outer edge of the side plate portion (318a, 325a) that is integrally connected to the flange portion (318b, 318c; 325b to 325d) in a curved shape. According to the second feature, the plate thickness increase area is set to include a portion of the outer edge of the side plate portion, that is, a portion that is integrally connected to the flange portion in a curved shape, thereby further improving the rigidity of the side frame.

[0038] In addition to the first feature or the second feature, the third feature of the present invention is that a portion of the plate thickness increased region (B1) surrounds the mounting component (330) to be mounted on the side plate portion (325a) from three directions. According to the third feature, the range of the mounting portion where the mounting component is mounted on the side plate portion is formed thicker from three directions, thereby achieving an improvement in the rigidity of the mounting portion.

[0039] In addition to any one of the first to third features, the present invention has a fourth feature that a backrest angle adjustment unit mounting portion (332) is provided on the side plate portion (325a) of the side frame (325A-325D) of the seat back frame (316), the backrest angle adjustment unit mounting portion (332) being used to mount a backrest angle adjustment unit (330) capable of adjusting the angle of the seat back frame (316) relative to the seat cushion frame (315), and the backrest angle adjustment unit mounting portion (332) is formed thicker than the increased plate thickness (tb1) of the plate thickness increased region (B1). According to the fourth feature, the backrest angle adjustment unit mounting portion provided for mounting the backrest angle adjustment unit on the side plate portion of the side frame of the seat back frame is thicker than the increased plate thickness of the plate thickness increased region, thereby improving the mounting rigidity of the backrest angle adjustment unit.

[0040] In addition, in addition to any one of the first to fourth features, the fifth feature of the present invention is that a reinforcement portion (337, 367) that bulges inward or outward is provided in a portion of the side plate portion (325a) included in the plate thickness increased region (B1). According to the fifth feature, a reinforcement portion that bulges inward or outward is provided in a portion of the side plate portion included in the plate thickness increased region, thereby further improving the rigidity of the side plate portion.

[0041] In addition to any one of the first to fifth features, the sixth feature of the present invention is that a reinforcing portion (338, 339) is provided on the side plate portion (325a) to connect mutually separated portions in the plate thickness increased region (B1). According to the sixth feature, the mutually separated portions in the plate thickness increased region are connected by the reinforcing portion, so that the rigidity of the side frame is further improved.

[0042] In addition, the present invention has a seventh feature in addition to any one of the first to sixth features, that is, through holes (340 to 346) are formed in the portion of the side plate portion (325a) included in the reference plate thickness region (A1). According to the seventh feature, through holes are formed in the reference plate thickness region in the side plate portion, thereby improving the processing accuracy of the through holes.

[0043] <Solution to the fourth technical problem and its effect> In order to achieve the fourth objective, the present invention provides a vehicle seat (411), the vehicle seat (411) having a seat back frame (425), the seat back frame (425) having left and right side frames (435), a lower frame (436) and an upper frame (437), wherein the left and right side frames (435) have a plate-like portion (435a), a front wall (435b) and a rear wall (435c), the plate-like portion (435a) being unfolded around a rotation axis along a vertical plane orthogonal to a rotation axis (SX) and extending upward along the vertical plane; the front wall (435b) being continuously and inwardly bent from a front edge of the plate-like portion (435a) to form a curved region (438) extending from around the rotation axis in a vertical direction; the rear wall (435c) being formed from the plate-like portion (435a) ) is continuously and inwardly bent from the rear edge of the rotation axis to form a curved area (439) extending in the vertical direction from the periphery of the rotation axis, the lower frame (436) has a back area (451), the back area (451) is arranged behind the rotation axis (SX), connected to the rear wall (435c) from the rear, and connects the left and right side frames (435) to each other; the upper frame (437) connects the left and right side frames (435) to each other above the lower frame (436), and the first feature of the vehicle seat (411) is that the lower frame (436) has a reinforcement area (452), the reinforcement area (452) is continuous from the lower edge of the back area (451), extends forward than the rotation axis (SX), and is connected to the front wall (435b) from the rear. According to the first feature, the lower frame is joined to each side frame in a reinforcement area in addition to the back area, so that the torsional rigidity of the seat back frame can be improved, wherein the reinforcement area starts from the lower edge of the back area and extends to a position forward of the rotation axis. Compared with the case where the lower frame is joined to the side frame only in the back area, the joining strength of the lower frame and the side frame can be reduced. In this way, the work load of joining can be reduced. In addition, when assembling the seat back frame, the lower frame can be assembled to the side frame from the rear. The side frame can be assembled to the lower frame from one direction. The workability of assembly will not be impaired.

[0044] In addition to the first feature, the present invention has a second feature that the side frame (435) has a space (459) formed between the front wall (435b) and the rear wall (435c) along the periphery of the plate-shaped portion (435a) around the rotation axis. According to the second feature, the front wall formed by bending along the periphery of the plate-shaped portion around the rotation axis and the rear wall formed by bending along the periphery of the plate-shaped portion around the rotation axis are separated by the space, so that when the side frame is stretched, the shape accuracy of the front wall and the rear wall can be improved compared to the case where the front wall and the rear wall are continuous around the rotation axis. Therefore, the assembly of the side frame relative to the lower frame is stable.

[0045] In addition to the first or second feature, the third feature of the present invention is that it further comprises a backrest angle adjustment mechanism (434) and a connecting component (445), wherein the backrest angle adjustment mechanism (434) is respectively mounted on the side frames (435) to connect the seat back frame (425) to the seat cushion frame (424) in a manner that it can rotate freely around the rotation axis (SX); the connecting component (445) connects the left and right backrest angle adjustment mechanisms (434), an opening (456) is formed in the back area (451) of the lower frame (436), and the opening (456) is used to allow a clamp (504) to pass through when assembling the seat back frame (425), and a square body (458) is formed on the connecting component (445), and the square body (458) is arranged in front of the opening (456) and is retained by the clamp (504). According to the third feature, the clamp can be inserted into the opening from the rear when assembling the seat back frame. The square body of the connecting component can be held on the clamp. In this way, the connecting component can be positioned on the left and right rotating bodies. The connecting component can be connected to each rotating body with good working efficiency.

[0046] In addition to any one of the first to third features, the present invention has a fourth feature that a first load-bearing surface (457) is formed on the back region (451) of the lower frame (436), the first load-bearing surface (457) is deployed in a first plane (Pf) and supported from the rear, and a second load-bearing surface (464) is formed on the rear wall (435c) of the side frame (435), the second load-bearing surface (464) is deployed in a second plane (Ps) set according to a positional relationship determined relative to the first plane (Pf), and when supported from the rear, the side frame (435) is positioned on the lower frame (436). According to the fourth feature, when the seat back frame is assembled, the lower frame can be physically supported by the first load-bearing surface. When the side frame is physically supported by the second load-bearing surface, the side frame can be positioned on the lower frame according to the positional relationship between the first plane and the second plane. The side frame can be easily positioned on the lower frame.

[0047] In addition, in addition to any one of the first to third features, the fifth feature of the present invention is that the upper frame (437) has a front wall (469), an upper wall (471), an upper vertical wall (472), a lower wall (473) and a lower vertical wall (474), wherein the front wall (469) is formed by bending a plate and is divided by an upper ridgeline (467) and a lower ridgeline (468) extending in a horizontal direction; the upper wall (471) is continuous from the upper ridgeline (467) and expands toward the rear; the upper vertical wall (472) extends from the rear end of the upper wall (471) toward the The upper frame (437) is formed by bending upward and joining with the rear wall (435c) from the front; the lower wall (473) is continuous from the lower ridgeline (468) and unfolds to the rear; the lower vertical wall (474) is formed by bending downward from the rear end of the lower wall (473) and joins with the rear wall (435c) from the front, and the inner edge of the front wall (435b) has a protrusion (483), which is unfolded inward from an imaginary contour line (483a) corresponding to the shape of the upper frame (437) and overlaps with the front wall (469) from the rear. According to the fifth feature, the upper frame can be assembled from the front to the left and right side frames arranged at intervals during assembly. At this time, the front wall of the side frame does not have to interfere with the upper vertical wall and the lower vertical wall in the upper frame located at a position farther back than the front wall. In this way, the working efficiency can be improved when assembling the upper frame.

[0048] In addition to the fifth feature, the sixth feature of the present invention is that the front wall (469) has a connecting piece (469a), which is bent forward at two locations on the left and right in the horizontal direction to form a recessed portion along the valley fold line (477) in the vertical direction, and extends toward the protruding piece (483), forming a reinforcing shape (493) in the recessed portion, and the reinforcing shape (493) extends while crossing the valley fold line (477) to strengthen the rigidity in the bending direction. According to the sixth feature, the rigidity of the front wall relative to the bending along the valley fold line can be improved. Therefore, when the upper frame is assembled, the deformation of the upper frame can be suppressed. The assembly work efficiency can be improved.

[0049] In addition to the fifth or sixth feature, the seventh feature of the present invention is that coaxial through holes (487, 488) for holding the headrest pillar (421) are formed on the upper wall (471) and the lower wall (473), and a reinforcing shape (494) is formed on the front wall (469). The reinforcing shape (494) extends while crossing the headrest pillar (421) when viewed from the front, thereby reinforcing the rigidity in the in-plane direction. According to the seventh feature, the rigidity of the front wall can be increased by corresponding to the through holes of the upper wall and the lower wall. Therefore, when the upper frame is assembled, the deformation of the upper frame can be suppressed. The assembly work efficiency can be improved.

[0050] In addition to the fifth or sixth feature, the eighth feature of the present invention is that coaxial through holes (487, 488) for holding the headrest pillar (421) are formed on the upper wall (471) and the lower wall (473), a flange (475) is formed on the upper vertical wall (472), the flange (475) is continuously bent forward from the upper end of the upper vertical wall (472), and a bearing piece (492) is formed on the flange (475) behind the through holes (487, 488), the bearing piece (492) is continuously bent upward or downward from the front edge of the flange (475). According to the eighth feature, the rigidity of the front wall can be improved by corresponding to the through holes of the upper wall and the lower wall. Therefore, when the upper frame is assembled, the deformation of the upper frame can be suppressed. The assembly work efficiency can be improved.

[0051] In addition to the eighth feature, the ninth feature of the present invention is that a support tube (507) is fixed to the upper wall (471) and the lower wall (473), and the support tube (507) is inserted into the through hole (488, 489) to support the headrest support guide (486) for guiding the headrest support (421), and the support sheet (492) supports the support tube (507) from the rear. According to the ninth feature, the rigidity of the front wall can be improved by the cooperation of the support tube and the support sheet. Therefore, when the upper frame is assembled, the deformation of the upper frame can be suppressed. The assembly work efficiency can be improved.

[0052] In addition, in addition to any one of the fifth to ninth features, the tenth feature of the present invention is that a first bearing surface (457) is formed on the back region (451) of the lower frame (436), the first bearing surface (457) is extended in the first plane (Pf) and is supported from the rear, and a second bearing surface (464) is formed on the rear wall (435c) of the side frame (435), the second bearing surface (464) is determined according to the first plane (Pf). The side frame (435) is arranged to be positioned on the lower frame (436) when supported from the rear, and a third bearing surface (496) is formed on the upper frame (437). The third bearing surface (496) is arranged to be positioned on the third plane (Pt) determined according to the positional relationship relative to the second plane (Ps), and the upper frame (437) is arranged to be positioned on the side frame (435) when supported from the rear. According to the tenth feature, when the seat back frame is assembled, the lower frame is physically supported by the first bearing surface. When the side frame is physically supported by the second bearing surface, the side frame is positioned on the lower frame according to the positional relationship between the first plane and the second plane. The side frame can be easily positioned on the lower frame. When the upper frame is physically supported by the third bearing surface, the upper frame is positioned on the side frame according to the positional relationship between the second plane and the third plane. The upper frame can be easily positioned on the side frame. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] <Description of the drawings showing embodiments of the solution to the first technical problem> Figure 1 It is a perspective view schematically showing the overall structure of the vehicle seat according to the first embodiment. Figure 2 It is a perspective view schematically showing the structure of a seat frame. Figure 3 It is a perspective view schematically showing the structure of a seat cushion pad and a seat back pad. Figure 4 It is an enlarged front view of the upper frame. Figure 5 It is an enlarged top view of the side frame. Figure 6 yes Figure 4 6-6 enlarged cross-sectional view. Figure 7 yes Figure 4 7-7 is an enlarged cross-sectional view. Figure 8 It is an enlarged perspective view schematically showing a part of a seat back frame assembled to a vehicle seat according to a second embodiment. Fig. 9 It is from Figure 8Enlarged perspective view of the seat back frame viewed from different angles. Fig.10 It is an enlarged side view schematically showing a part of a seat back frame assembled to a vehicle seat according to a third embodiment. Fig.11 It is an enlarged bottom view schematically showing the structure of the foldable table. Fig.12 It is a partially enlarged front view schematically showing a support structure of a headrest pillar guide portion according to another embodiment. Fig.13 yes Fig.12 13-13 is an enlarged cross-sectional view. Fig.14 It is a partially enlarged front view schematically showing a support structure of a headrest pillar guide portion according to still another embodiment. Fig.15 yes Fig.14 15-15 enlarged cross-sectional view.

[0054] <Description of the drawings showing embodiments of the solution to the second technical problem> Fig.16 It is a perspective view of the seat frame according to the first embodiment. Fig.17 It is a side view of the side frame of the seat back. Fig.18 yes Fig.17 18-18 cross-sectional view. Fig.19 This is a diagram for showing the installation structure of the airbag to the side frame of the seat back, which is a diagram of the seat device. Fig.16 19-19 longitudinal section view in FIG. Fig. 20 It is a side view of the side frame of the seat cushion. Fig.21 yes Fig. 20 21-21 cross-sectional view. Fig. 22 It is a side view of the seat back side side frame of the second embodiment. Fig.23 It is a side view of the seat back side frame of the third embodiment. Fig.24 It is a side view of the seat back side frame of the fourth embodiment.

[0055] <Description of the drawings showing embodiments of the solution to the third technical problem> Fig.25 It is a perspective view of the seat frame according to the first embodiment. Fig.26 It is a side view of the side frame of the seat back. Fig. 27 yes Fig.26 Sectional view 27-27 of FIG. Fig.28 yes Fig.26 Sectional view 28-28 of FIG. Fig.29 It is a side view of the side frame of the seat cushion. Fig.30 yes Fig.29 30-30 cross-sectional view. Fig.31 It is a side view of the seat back side side frame of the second embodiment. Fig.32 It is a side view of the seat back side frame of the third embodiment. Fig.33 It is a side view of the seat back side frame of the fourth embodiment. Fig.34 It is a left side view of the left side backrest angle adjustment unit and its surrounding parts according to the fifth embodiment. Fig.35 It is a right side view showing the right side backrest angle adjustment unit and its surrounding parts according to the fifth embodiment. Fig.36 yes Fig.34 36-36 enlarged cross-sectional view. Fig.37 yes Fig.35 37-37 enlarged cross-sectional view.

[0056] <Description of the drawings showing embodiments of the solution to the fourth technical problem> Fig.38 It is a perspective view schematically showing the overall structure of the vehicle seat according to the first embodiment. Fig.39 It is a perspective view schematically showing the structure of a seat frame. Fig.40 It is a perspective view schematically showing the structure of a seat cushion pad and a seat back pad. Fig.41 It is the main view of the lower frame. Fig.42 is the rear view of the lower frame. Fig.43 yes Fig.41 An enlarged cross-sectional view of 43-43. Fig.44 It is a bottom view of an enlarged portion of the seat back frame. Fig.45 It is the main view of the upper frame. Fig.46 It is a magnified front view of a portion of the side frame. Fig.47 yes Fig.45 Sectional view 47-47 of FIG. Fig.48 It is an enlarged stereoscopic view of the upper wall of the upper frame. Fig.49 This is a cross-sectional view of the lower frame cut along a cutting plane passing through the central axis of the insertion hole. Fig.50 This is a cross-sectional view of the side frame cut along a cutting plane that overlaps with the lower frame and passes through the central axis of the insertion hole. Fig.51 This is a cross-sectional view of the upper frame cut along a cutting plane that overlaps with the side frame and passes through the center axis of the insertion hole. Fig.52 It is a cross-sectional view of the lower frame and the connecting shaft cut with a cutting plane passing through the central axis of the opening. Fig.53 It is a front view of an upper frame involved in a modification. Fig.54 It is a cross-sectional view of the lower frame and the connecting shaft cut along a cutting plane passing through the center axis of the opening, and is a diagram showing the connecting shaft involved in another specific example. Fig.55 This is a front view schematically showing the support tube inserted into the upper wall and the lower wall of the upper frame. Fig.56 yes Fig.55 Sectional view 56-56 of FIG. Description of Reference Numerals

[0057] <Description of Reference Numerals Indicating Embodiments of Solution to First Problem> 11: vehicle seat; 21: headrest support; 25: seat back frame; 25a: seat back frame of the second embodiment; 25b: seat back frame of the third embodiment; 36: rotation axis (support axis); 38: side frame; 38a, 38b, 38c: plate-like portion, front wall, rear wall; 39: upper frame; 41: curved region (of the front wall); 42: curved region (of the rear wall); 43: side frame flange; 52, 53: upper ridgeline, lower ridgeline; 54, 55, 57: front wall, upper wall, lower wall of the upper frame; 56, 58: upper vertical wall, lower vertical wall of the upper frame; 62: flange (second flange ); 65: welding mark (of the front wall); 68: imaginary contour line; 69: protrusion; 75: headrest guide; 76, 77: the first supporting hole, the second supporting hole; 79: supporting hole flange; 81: upper frame of the second embodiment; 82, 83: upper ridge line, lower ridge line; 84, 85, 87: the front wall, upper wall, lower wall of the upper frame of the second embodiment; 86, 88: the upper vertical wall, lower vertical wall of the upper frame of the second embodiment; 92: flange (second flange); 95: welding mark (of the front wall); 111: upper frame of the third embodiment; SX: rotation axis (swing axis) of the side frame.

[0058] <Description of Reference Numerals Indicating Embodiments of Solution to Second Problem> 215: Cushion frame; 216: Seat back frame; 218, 225, 225A, 225B, 225C, 225D: Side frames; 219: Disc frame as a connecting component; 220: Rear pipe as a connecting component; 227: Lower frame as a connecting component; 228: Headrest mounting bracket as a connecting component; 234: Backrest side pressure-bearing component as an installation component; 237-239, 267-274: Reinforcement parts; 240-246: Through holes; 251: Airbag as an installation component; 256: Reinforcement lining as an installation component; 263: Auxiliary component; L1-L4: Plate thickness dividing line.

[0059] <Description of Reference Numerals Indicating Embodiments of Solution to Third Problem> 315: seat cushion frame 316: seat back frame; 318, 325A, 325B, 325C, 325D: side frames; 318a, 325a: side plate portions; 318b, 318c, 325b, 325c, 325d: flange portions; 330: backrest angle adjustment unit as an installation component; 332: backrest angle adjustment unit installation portion; 337, 338, 339, 367: reinforcement portions; 340-346: through holes; A1, A2: reference plate thickness areas; B1, B2: plate thickness increase areas; ta1, ta2: reference plate thickness; tb1, tb2: increased plate thickness.

[0060] <Description of Reference Numerals Indicating Embodiments of Solution to Fourth Problem> 411: vehicle seat (vehicle seat); 421: headrest support; 424: seat cushion frame; 425: seat back frame; 434: backrest angle adjustment mechanism (backrest angle adjustment unit); 435: side frame; 435a, 435b, 435c: plate-like portion, front wall, rear wall of the side frame; 436: lower frame; 437: upper frame; 438, 439: bending area; 445: connecting member (connecting shaft); 451, 452: back area, reinforcement area; 456: opening; 457, 467, 496: first load-bearing surface, second load-bearing surface, third load-bearing surface; 458: square body; 459: space 467, 468: upper ridge line, lower ridge line; 469, 471, 473: front wall, upper wall, lower wall; 469a: connecting piece; 472, 474: upper vertical wall, lower vertical wall; 475: flange (1st flange); 477: valley fold line; 483: protrusion; 483a: imaginary contour line; 486: headrest pillar guide; 487, 488: through hole (1st through hole, 2nd through hole); 492: bearing piece; 493, 494: reinforcement shape (convex ridge); 504: clamp; 507: support tube; Pf, Ps, Pt: 1st plane, 2nd plane, 3rd plane; SX: rotation axis (swing axis). DETAILED DESCRIPTION

[0061] <Method of implementing the solution to the first technical problem> Next, refer to the attached Figure 1 In the following description, front and rear, left and right, and up and down refer to directions viewed by a passenger seated on a vehicle seat in a normal sitting posture (basic posture during driving).

[0062] Figure 1The overall structure of a vehicle seat according to a first embodiment of the present invention is schematically shown. The vehicle seat 11 includes a slide rail 13 connected to a floor 12 that functions as a structural element of a monocoque structure of a vehicle, for example; a seat cushion 14 that is supported on the slide rail 13 in a manner that allows movement in the front-rear direction and supports the buttocks and thighs of an occupant; a seat back 15 that is connected to the seat cushion 14 in a manner that allows swinging about a swing axis SX in the front-rear direction and supports the back of the occupant; and a headrest 16 that is supported on the upper end of the seat back 15 and supports the head of the occupant. The seat cushion 14, the seat back 15, and the headrest 16 each include a skin material 14a, 15a, 16a that covers the padding inside. The skin materials 15a, 16a are in close contact with the outer surface of the padding along the recessed portion of the padding by the action of a hanging wire 17. The details of the padding will be described later. The vehicle seat 11 is configured to be used for a left-side seat. When the vehicle seat 11 is used as a right-side seat, the vehicle seat 11 may be switched left and right.

[0063] The seat cushion 14 has a side cover 18. A first switch 19a and a second switch 19b are mounted on the side cover 18. The first switch 19a is formed by an adjuster that is long in the front-rear direction. When the first switch 19a is operated forward, the seat cushion 14 and the seat back 15 move forward. When the first switch 19a is operated backward, the seat cushion 14 and the seat back 15 move backward. When the first switch 19a is operated upward, the seat cushion 14 and the seat back 15 move upward. When the first switch 19a is operated downward, the seat cushion 14 and the seat back 15 move downward. The second switch 19b is formed by an adjuster that is long in the up-down direction. When the second switch 19b is operated forward, the seat back 15 swings forward around the swing axis SX. When the second switch 19b is operated backward, the seat back 15 swings backward around the swing axis SX.

[0064] The headrest 16 is fixed to a headrest pillar 21 extending upward from the upper end of the seat back 15. The headrest pillar 21 is supported by the seat back 15 so as to be freely displaceable in the axial direction in the vertical direction. The height of the headrest 16 can be adjusted according to the displacement of the headrest pillar 21.

[0065] like Figure 2As shown, the vehicle seat 11 has a seat frame 23 that supports a cushion. The seat frame 23 has a cushion frame 24 that supports the cushion of the seat cushion 14; a seat back frame 25 that is connected to the cushion frame 24 in a swingable manner around a swing axis SX and supports the cushion of the seat back 15; and a base frame 26 that is guided by the slide rail 13 in a manner that allows free forward and backward movement in the longitudinal direction and supports the cushion frame 24 on the slide rail 13. The cushion frame 24 is connected to the base frame 26 through a link mechanism 27. The link mechanism 27 has a link member 28, one end of which is connected to the base frame 26 in a manner that allows free rotation around a horizontal axis FH extending in the left-right direction, and the other end of which is connected to the cushion frame 24 in a manner that allows free rotation around a horizontal axis SH extending in the left-right direction parallel to the horizontal axis FH. The link member 28 guides the cushion frame 24 to move up and down relative to the base frame 26 around the horizontal axis FH.

[0066] The seat cushion frame 24 includes: a seat cushion side frame 24a, which is arranged and extended along each slide rail 13; a disc frame 24b, which connects the seat cushion side frames 24a to each other at the front end of the seat cushion 14; and a connecting pipe 24c, which connects the seat cushion side frames 24a to each other at the rear end of the seat cushion 14. A plurality of S-shaped springs (not shown) are arranged between the disc frame 24b and the connecting pipe 24c. Each S-shaped spring extends forward and backward in a zigzag shape. The zigzag shape is formed by staggered combination of wires extending in the front-back direction and wires extending in the left-right direction.

[0067] An electric forward and backward moving device 29 is mounted on the base frame 26. The electric forward and backward moving device 29 has an electric motor 31 supported on the base frame 26. The electric motor 31 generates power in response to the supply of electric power. Power is supplied based on the operation of the first switch 19a. The power of the electric motor 31 causes the base frame 26 to move forward and backward along the slide rail 13.

[0068] An electric vertical movement device 32 is mounted on the cushion side frame 24a of the cushion frame 24. The electric vertical movement device 32 has an actuator 33, which is supported by the cushion side frame 24a and connected to the link mechanism 27. The actuator 33 includes: an electric motor 34, which is arranged outside the cushion side frame 24a and generates power in response to the supply of electric power; and a transmission mechanism 35, which causes the link member 28 to rotate relative to the cushion side frame 24a around the horizontal axis SH in response to the power of the electric motor 34. The transmission mechanism 35 is composed of a gear set, which includes, for example, a driving gear fixed to the driving shaft of the electric motor 34 and a driven gear fixed to the link member 28 around the horizontal axis SH, and meshes with each other in sequence. Electric power is supplied based on the operation of the first switch 19a. The power of the electric motor 34 causes the cushion side frame 24a to move up and down around the horizontal axis FH.

[0069] A support shaft 36 is assembled on the seat cushion frame 24 at the upper rear of the connecting pipe 24c in a manner coaxial with the swing axis SX. The support shaft 36 is formed of, for example, a hollow metal pipe. The metal pipe has high rigidity in the axial direction. The support shaft 36 is clamped by the left and right seat cushion side frames 24a. The seat back frame 25 is supported on the support shaft 36.

[0070] The seat back frame 25 includes left and right side frames 38 connected to the inner sides of the cushion side frames 24a by the support shaft 36, and an upper frame 39 connecting the upper ends of the side frames 38 to each other above the support shaft 36. The side frame 38 includes a plate-like portion 38a that is developed around the support shaft 36 along a vertical plane orthogonal to the swing axis SX and extends upward along the vertical plane, a front wall 38b that is continuous from the front edge of the plate-like portion 38a and is bent inward to form a curved region 41 extending in the vertical direction from the periphery of the support shaft 36, and a rear wall 38c that is continuous from the rear edge of the plate-like portion 38a and is bent inward to form a curved region 42 extending in the vertical direction from the periphery of the support shaft 36. The front wall 38b and the rear wall 38c are continuous around the support shaft 36. The rear wall 38c has a side frame flange 43, which is continuous from the inner end of the rear wall 38c and is bent forward. Each side frame 38 is formed of, for example, a sheet of metal. A headrest support guide 44 is fixed to the upper frame 39, and the headrest support guide 44 supports the headrest support 21 in a manner that allows it to slide in the up-down direction. The details of the upper frame 39 will be described later.

[0071] An electric backrest angle adjustment device 45 is mounted on the side frame 38 of the seat back frame 25. The electric backrest angle adjustment device 45 has an actuator 46, which is mounted on the side frame 38 of the seat back frame 25 around the swing axis SX. The actuator 46 is formed by an electric motor 47, wherein the electric motor 47 generates power in response to the supply of electric power, and a transmission mechanism 48, wherein the electric motor 47 generates power in response to the supply of electric power; and the transmission mechanism 48 converts the power of the electric motor 47 into a driving force around the swing axis SX. The electric motor 47 generates power in response to the supply of electric power. Electric power is supplied based on the operation of the second switch 19b. The power of the electric motor 47 causes the seat back frame 25 to swing back and forth relative to the seat cushion frame 24 around the swing axis SX.

[0072] like Figure 3 As shown, the seat cushion 14 further includes a seat cushion pad 49, which is supported by the seat cushion frame 24 and covered by the skin material 14a. The seat back 15 further includes a seat back pad 51, which is supported by the seat back frame 25 and covered by the skin material 15a. The seat cushion pad 49 and the seat back pad 51 are formed of an elastic material such as polyurethane foam.

[0073] like Figure 4 As shown, the upper frame 39 includes: a front wall 54 formed by bending a plate material and divided by an upper ridgeline 52 and a lower ridgeline 53 extending in the horizontal direction; an upper wall 55 that is continuous from the upper ridgeline 52 and extends rearward; an upper vertical wall 56 that is bent upward from the rear end of the upper wall 55; a lower wall 57 that is continuous from the lower ridgeline 53 and extends rearward; and a lower vertical wall 58 that is bent downward from the rear end of the lower wall 57. The upper vertical wall 56 includes a first flange 61 that is continuous from the upper end of the upper vertical wall 56 and is bent forward. The first flange 61 is continuous along the upper edge of the upper vertical wall 56 and covers the entire region in the horizontal direction. The lower vertical wall 58 includes a second flange 62 that is continuous from the lower end of the lower vertical wall 58 and is bent forward. The second flange 62 is continuous along the lower edge of the lower vertical wall 58 and covers the entire region in the horizontal direction.

[0074] The front wall 54 is bent forward at two locations in the horizontal direction, and a concave portion is formed along the valley fold line 63 in the vertical direction. The front wall 54 is further bent backward in the horizontal direction outside the concave portion, and a ridge line is formed along the mountain fold line 64 in the vertical direction. As the front wall 54 is deformed, the upper wall 56 and the lower wall 58 are also deformed in the same manner. The upper frame 39 is formed of, for example, a single metal plate.

[0075] A welding mark 65 is formed on the front wall 54 at a position outside the mountain fold line 64 in the horizontal direction. Welding marks 66 and 67 are formed on the upper and lower walls 56 and 58 corresponding to the upper and lower sides of the welding mark 65. The upper frame 39 is fixed to the left and right side frames 38 at the welding marks 65, 66, and 67. Spot welding, arc welding, or laser welding can be used for welding.

[0076] The curved area 41 formed by the front wall 38b on the side frame 38 extends to the upper end of the side frame 38 and reaches the upper frame 39. The curved area 42 formed by the rear wall 38c extends to the upper end of the side frame 38 and reaches the upper frame 39. Figure 5 As shown, the inner edge of the front wall 38b has a protrusion 69, which spreads inward from an imaginary contour line 68 corresponding to the edge of the upper frame 39 and overlaps with the front wall 54 of the upper frame 39 from the rear. The front wall 54 of the upper frame 39 forms a welding mark 65 between the protrusion 69 and the protrusion.

[0077] The inner edge of the rear wall 38c includes an upper overlapping piece 71 which is continuous from the rear wall 38c and overlaps the upper vertical wall 56 of the upper frame 39 from the rear, and a lower overlapping piece 72 which is located below the upper overlapping piece 71, is spaced apart from the upper overlapping piece 71, is continuous from the rear wall 38c and overlaps the lower vertical wall 58 of the upper frame 39 from the rear. The upper vertical wall 56 of the upper frame 39 forms a welding mark 66 with the upper overlapping piece 71. Similarly, the lower vertical wall 58 of the upper frame 39 forms a welding mark 67 with the lower overlapping piece 72.

[0078] The upper overlapping piece 71 of the rear wall 38c has an upper flange 73 which is bent forward from the upper edge of the upper overlapping piece 71. The upper flange 73 covers a predetermined length from the left and right ends of the first flange 61 of the upper frame 39 and faces the first flange 61. The lower overlapping piece 72 of the rear wall 38c has a lower flange 74 which is bent forward from the lower edge of the lower overlapping piece 72. The lower flange 74 covers a predetermined length from the left and right ends of the second flange 62 of the upper frame 39 and faces the second flange 62. In this way, in the upper frame 39, the upper flange 73 is formed at a position corresponding to the first flange 61 in the horizontal direction, and the lower flange 74 is formed at a position corresponding to the second flange 62 in the horizontal direction.

[0079] like Figure 6 As shown, the upper flange 73 is bent with a smaller curvature than the first flange 61. The first flange 61 can be well received inside the upper flange 73. Interference between the first flange 61 and the upper flange 73 can be avoided. The lower flange 74 is bent with a larger curvature than the second flange 62 at a position away from the second flange 62 from below. The second flange 62 can be well received inside the lower flange 74. Interference between the second flange 62 and the lower flange 74 can be avoided. The side frame flange 43 is continuous from the lower flange 74.

[0080] like Figure 7 As shown, the upper frame 39 has: a first support hole 76 formed on the upper wall 55 for supporting the headrest pillar guide 75; and a second support hole 77 formed on the lower wall 57 for supporting the headrest pillar guide 75. The headrest pillar guide 75 supports the headrest pillar 21 in a manner that it can be freely displaced in the axial direction. A positioning flange 78 is formed on the headrest pillar guide 75, which is extended in a direction orthogonal to the axis. When the headrest pillar guide 75 is inserted into the first support hole 76 and the second support hole 77 from above, the positioning flange 78 contacts the upper wall 55 from above to position the headrest pillar guide 75 in the axial direction. The headrest pillar guide 75 can be molded from a resin material, for example.

[0081] A support hole flange 79 bent downward is formed at the periphery of the first support hole 76 and the second support hole 77. The headrest pillar guide 75 is pressed into the support hole flange 79. The support hole flange 79 fixes the headrest pillar guide 75 to the upper frame 39. The support hole flange 79 can prevent the headrest pillar guide 75 from being separated from the upper frame 39.

[0082] Figure 8 A portion of a seat back frame 25a assembled to a vehicle seat according to a second embodiment of the present invention is schematically shown. Like the seat back frame 25, the seat back frame 25a includes left and right side frames 38 connected to the inner sides of the cushion side frames 24a by support shafts 36, and an upper frame 81 connecting the upper ends of the side frames 38 to each other above the support shafts 36. The structure of the vehicle seat is the same as that of the vehicle seat 11 described above except for the upper frame 81.

[0083] The upper frame 81 includes: a front wall 84 formed by bending a plate and divided by an upper ridgeline 82 and a lower ridgeline 83 extending in the horizontal direction; an upper wall 85 that is continuous from the upper ridgeline 82 and spreads backward; an upper vertical wall 86 that is bent upward from the rear end of the upper wall 85; a lower wall 87 that is continuous from the lower ridgeline 83 and spreads backward; and a lower vertical wall 88 that is bent downward from the rear end of the lower wall 87. The upper vertical wall 86 includes a first flange 91 that is continuous from the upper end of the upper vertical wall 86 and is bent forward. The first flange 91 is continuous along the upper edge of the upper vertical wall 86 and covers the entire area in the horizontal direction. The upper flange 73 of the side frame 38 covers a predetermined length from the left and right ends of the first flange 91 of the upper frame 81 and faces the first flange 91. The lower vertical wall 88 has a second flange 92 which is continuous from the lower end of the lower vertical wall 88 and is bent forward. The second flange 92 is continuous along the lower edge of the lower vertical wall 88 and covers the entire area in the horizontal direction. The lower flange 74 of the side frame 38 covers a predetermined length from the left and right ends of the second flange 92 of the upper frame 81 and faces the second flange 92.

[0084] The front wall 84 is bent forward at two locations in the horizontal direction, and a concave portion is formed along the valley fold line 93 in the vertical direction. The front wall 84 is further bent backward in the horizontal direction outside the concave portion, and a ridge line is formed along the mountain fold line 94 in the vertical direction. As the front wall 84 is deformed, the upper wall 86 and the lower wall 88 are also deformed in the same manner. The upper frame 81 is formed of, for example, a single metal plate.

[0085] A welding mark 95 is formed on the front wall 84 at a position outside the mountain fold line 94 in the horizontal direction. A welding mark 95 is formed between the front wall 84 of the upper frame 81 and the protruding piece 69 of the side frame 38. Corresponding to the upper and lower sides of the welding mark 95, welding marks 96 and 97 are formed on the upper vertical wall 86 and the lower vertical wall 88. At the welding marks 95, 96, and 97, the upper frame 81 is fixed to the left and right side frames 38. The upper vertical wall 86 of the upper frame 81 forms a welding mark 96 between it and the upper overlapping piece 71 of the side frame 38. Similarly, the lower vertical wall 88 of the upper frame 81 forms a welding mark 97 between it and the lower overlapping piece 72.

[0086] A blower fan 101 of a seat ventilation system 99 is fixed to the lower vertical wall 88 of the upper frame 81. The blower fan 101 has a housing 102 which houses an impeller that rotates around the rotation axis Rx. The housing 102 is formed into a flat cylindrical shape coaxially with the rotation axis Rx, and has an air inlet 103 extending in a tangential direction of the circular contour. On the outer periphery of the housing 102, two or more fixing plates 104 are formed that are unfolded along a plane orthogonal to the rotation axis Rx. The fixing plates 104 overlap the surface of the lower vertical wall 88. The fixing plates 104 are connected to the lower vertical wall 88 by screws 105 that are screwed into the lower vertical wall 88. The screws 105 have an axis parallel to the rotation axis Rx.

[0087] like Fig. 9 As shown in FIG. 1 , an air supply duct 106 is installed on the rear surface of the housing 102. The air supply duct 106 blocks the opening formed on the rear wall of the housing 102 and carries the air flow generated in the axial direction of the rotation axis Rx by the rotation of the impeller. The seat ventilation system 99 has a passage formed in the seat back cushion 51 and connected to the air supply duct 106. The air flow is supplied from the passage of the seat back cushion 51 to the back of the occupant leaning on the seat back 15.

[0088] The air supply duct 106 is provided with a mounting flange 106b, which extends outward from the tube body 106a for guiding the air flow, and overlaps with the rear surface of the housing 102 around the opening of the rear wall. A notch 107 is formed on the lower vertical wall 88 of the upper frame 81, and the shape of the notch 107 corresponds to the outline of the mounting flange 106b. The mounting flange 106b is accommodated in the notch 107. Around the mounting flange 106b, the rear surface of the housing 102 is in close contact with the surface of the lower vertical wall 88. At the notch 107, the second flange 92 is interrupted.

[0089] Fig.10A portion of a seat back frame 25b assembled to a vehicle seat according to a third embodiment of the present invention is schematically shown. Like the seat back frame 25, the seat back frame 25b includes left and right side frames 38 connected to the inner sides of the cushion side frames 24a by support shafts 36, and an upper frame 111 connecting the upper ends of the side frames 38 to each other above the support shafts 36. The upper frame 111 has the same structure as the upper frame 39. The structure of the vehicle seat except for the upper frame 111 is the same as that of the vehicle seat 11 described above.

[0090] A foldable table 112 is mounted on the front wall 54 of the upper frame 111. The table 112 includes a mounting body 113 fixed to the front wall 54 and a top plate 115 connected to the mounting body 113 via a wiring frame 114 and movable between a horizontally unfolded working position and a stowed position stowed along the back of the seat back 15. Fig.11 As shown, the wiring frame 114 includes: a pair of left and right connecting wirings 114a, which are fixed to the lower surface of the top plate 115 and extend toward the mounting body 113; and an axial wiring 114b, which is bent from the top of the connecting wiring 114a and is rotatably supported on the mounting body 113 in a manner coaxial with the axis Wx. A cam piece 116 is formed on the mounting body 113, and the cam piece 116 supports the axial wiring 114b rotatably and defines the trajectory of the connecting wiring 114a during rotation. The cam piece 116 has a protrusion 116a, and when the connecting wiring 114a is driven from the working position to the storage position around the axis Wx based on an external force, the protrusion 116a is elastically deformed in a manner that the connecting wirings 114a are close to each other. The protrusion 116a restricts the movement of the connecting wiring 114a around the axis Wx, and therefore, the top plate 115 can be maintained in the working position or the storage position by the action of the protrusion 116a. The protrusion 116a causes the axial wiring 114b to be displaced in the axial direction of the axial wiring 114b due to the rotational movement of the connecting wiring 114a about the axis Wx.

[0091] like Fig.12 As shown in FIG. 1 , when the headrest support pillar guide portion 75 is supported on the upper frame 39, the support cylinder 117 penetrating the upper wall 55 and the lower wall 57 can also be inserted into the first support hole 118 and the second support hole 119. Here, small pieces 121 and 122 are bent upward and downward from the periphery of the first support hole 118 and the second support hole 119, respectively. Fig.13As shown, each small piece 121, 122 overlaps with the outer surface of the support tube 117. The small pieces 121, 122 are welded to the support tube 117. In this way, the support tube 117 is fixed to the upper frame 39. As with the welding of the upper frame 39 and the side frame 38, the welding can be performed from the front, thereby improving the work efficiency of assembling the seat frame 23. The headrest support guide 75 is pressed into the support tube 117. Similarly, when the headrest support guide 75 is supported on the upper frame 81, 111, the support tube 117 that passes through the upper wall 85 (55) and the lower wall 87 (57) can also be inserted into the first support hole 118 and the second support hole 119.

[0092] In addition, Fig.14 As shown in FIG. 1 , when the headrest support pillar guide 75 is supported on the upper frame 39, the support cylinder 117 penetrating the upper wall 55 and the lower wall 57 can also be inserted into the first support hole 118 and the second support hole 119. Here, a recessed portion 123 is formed on the front wall 54 to be recessed toward the headrest support pillar guide 75. The recessed portion 123 has a flat bottom plate 123a. Fig.15 As shown, the bottom plate 123a of the recessed portion 123 overlaps with the outer surface of the support tube 117. The bottom plate 123a is welded to the support tube 117. In this way, the support tube 117 is fixed to the upper frame 39. As with the welding of the upper frame 39 and the side frame 38, the welding can be performed from the front, thereby improving the work efficiency when assembling the seat frame 23. The headrest support guide 75 is pressed into the support tube 117. Similarly, when the headrest support guide 75 is supported on the upper frame 81, 111, the support tube 117 that passes through the upper wall 85 (55) and the lower wall 87 (57) can also be inserted into the first support hole 118 and the second support hole 119.

[0093] <Method of implementing the solution to the second technical problem> Next, refer to the attached Figure 1 In the following description, "front and rear", "left and right", and "up and down" refer to directions viewed by a seated person when the seated person is in a posture facing forward in the front-rear direction of the vehicle.

[0094] First, in Fig.16 In the seat frame 212, there is a cushion frame 215, which supports the seat cushion (not shown); and a seat back frame 216, which supports the seat back 214 (refer to Fig.19) and is connected to the seat cushion frame 215, and a height adjustment mechanism 217 capable of adjusting the height of the seat cushion frame 215 is provided between the seat cushion frame 215 and the slide rail 211, wherein the seat frame 212 can move along a pair of the slide rails 211, and the pair of slide rails 211 are spaced apart in the vehicle width direction and arranged parallel to each other and extend in a straight line.

[0095] The seat cushion frame 215 includes: a pair of seat cushion side frames 218, which are arranged at positions separated from each other in the vehicle width direction and extend linearly in the vehicle front-rear direction; a disc frame 219, which serves as a connecting component connecting the front ends of these seat cushion side frames 218; and a rear pipe 220, which serves as another connecting component connecting the rear ends of a pair of the seat cushion side frames 218.

[0096] A seat cushion side pressure receiving member 221 is provided between the disc frame 219 and the rear tube 220. The seat cushion side pressure receiving member 221 is elastically deformed by the seat cushion bearing the load of the seated person. The seat cushion side pressure receiving member 221 includes a plurality of (four in this embodiment) seat springs 222 formed by bending a metal wire in a zigzag manner so as to extend in a zigzag manner to the left and right. The seat springs 222 are arranged so that adjacent seat springs 222 are symmetrical to each other. The front ends of the plurality of seat springs 222 are respectively engaged with the stopper 223 provided on the disc frame 219 in the seat frame 212. In addition, the rear ends of the adjacent seat springs 222 are engaged with the rear tube 220 of the seat frame 212 and connected together by a resin rear end connecting member 224 integrally formed with the seat springs by insert molding, and the rear end connecting member 224 is formed so as to cover the rear tube 220.

[0097] The seat back frame 216 includes: a pair of seat back side frames 225A, which are arranged at positions separated from each other in the vehicle width direction and extend in the up-down direction; a headrest mounting bracket 226, which serves as a connecting component connecting the upper portions of these seat back side frames 225A; and a lower frame 227, which serves as a connecting component connecting the lower end portions of the pair of seat back side frames 225A.

[0098] The seat back side frame 225A integrally comprises a side plate portion 225a, a front flange portion 225b and a rear flange portion 225c, wherein the front flange portion 225b extends inwardly from the front edge portion of the side plate portion 225a; the rear flange portion 225c extends inwardly from the rear edge portion of the side plate portion 225a, and the seat back side frame 225A is formed by press forming of a metal sheet and basically has a roughly U-shaped cross-sectional shape that expands as it leans inward, and a bracket support portion 225d having a roughly C-shaped cross-sectional shape is formed on the upper portion of the seat back side frame 225A.

[0099] The headrest mounting bracket 226 is formed by bending a pipe into a substantially U-shape as it opens downward, and both ends of the headrest mounting bracket 226 are fitted and fixed to the bracket support portion 225d on the upper portion of the seat back side frame 225A. In addition, a pair of cylindrical headrest support members 228 are fixed to the headrest mounting bracket 226.

[0100] Connecting brackets 229 are fastened to the rear ends of the left and right pair of cushion side frames 218, respectively, and the lower ends of the left and right pair of seat back side frames 225A are connected to these connecting brackets 229 through the back angle adjustment unit 230. The rotation shaft 231 of the back angle adjustment unit 230 penetrates the lower frame 227 and is installed on the lower ends of the left and right pair of seat back side frames 225A, wherein the lower frame 227 is connected to the lower ends of these seat back side frames 225A, so that the angle of the seat back frame 216 relative to the seat frame 212 can be adjusted by the action of the back angle adjustment unit 230.

[0101] In addition, a backrest side pressure receiving member 234 is arranged between the left and right seat back side frames 225A, and the backrest side pressure receiving member 234 can be elastically deformed by the seat back bearing the load of the seated person. The backrest side pressure receiving member 234 is formed of resin or the like so as to be elastically deformable and is bridged between the left and right seat back side frames 225A through an upper connecting wire 235 and a lower connecting wire 236.

[0102] exist Fig.17In the side plate portion 225a of the seat back side frame 225A, a first reinforcement portion 237, a second reinforcement portion 238, and a third reinforcement portion 239 that bulge inward or outward are provided. The first reinforcement portion 237 extends along the rear edge of the side plate portion 225a and is extended in the up-down direction. The second reinforcement portion 238 and the third reinforcement portion 239 extend in a direction intersecting the length direction of the seat back side frame 225A. The second reinforcement portion 238 extends from the middle portion in the up-down direction of the first reinforcement portion 237 to the front in the vehicle front-back direction and is provided on the side plate portion 225a. The third reinforcement portion 239 extends from the lower end portion of the first reinforcement portion 237 to the front in the vehicle front-back direction and is provided on the side plate portion 225a. In the present embodiment, the first reinforcement portion 237 , the second reinforcement portion 238 , and the third reinforcement portion 239 are formed so that the seat back side frame 225A bulges inward during the press working.

[0103] exist Fig.18 In the embodiment, the seat back side frame 225A is formed in a shape where the plate thickness changes at the plate thickness boundary line, and the plate thickness boundary line is arranged at a plurality of positions in the longitudinal direction of the seat back side frame 225A. In the present embodiment, the seat back side frame 225A is set with a first plate thickness boundary line L1 and a second plate thickness boundary line L2. Furthermore, the first plate thickness boundary line L1 and the second plate thickness boundary line L2 are set at positions avoiding the connection portion where the headrest mounting bracket 226 and the lower frame 227 are connected to the seat back side frame 225A. The first plate thickness boundary line L1 is arranged at a position close to the lower part of the seat back side frame 225A, and the second plate thickness boundary line L2 is arranged above the first plate thickness boundary line L1 and at a middle position in the longitudinal direction of the seat back side frame 225A.

[0104] The plate thickness t2 of the seat back side frame 225A between the first plate thickness dividing line L1 and the second plate thickness dividing line L2 is smaller than the plate thickness t1 of the seat back side frame 225A below the first plate thickness dividing line L1, and the plate thickness t3 of the seat back side frame 225A above the second plate thickness dividing line L2 is smaller than the plate thickness t2. In this way, the seat back side frame 225A is formed to be gradually thinner in thickness as it moves upward.

[0105] Reference Fig.17The first reinforcement portion 237 crosses the second plate thickness boundary line L2 and is arranged on the side plate portion 225a, and the second reinforcement portion 238 and the third reinforcement portion 239 are arranged at positions avoiding the first plate thickness boundary line L1 and the second plate thickness boundary line L2. In the present embodiment, the second reinforcement portion 238 and the third reinforcement portion 239 are arranged between the first plate thickness boundary line L1 and the second plate thickness boundary line L2 in the up and down directions, and are arranged on the side plate portion 225a.

[0106] In addition, a first through hole 240 and a second through hole 241 are formed on the side plate portion 225a to avoid the first plate thickness dividing line L1 and the second plate thickness dividing line L2. The first through hole 240 and the second through hole 241 are used to install the upper connecting wiring 235 and the lower connecting wiring 236 of the backrest side pressure-bearing component 234. In the present embodiment, the first through hole 240 is formed on the side plate portion 225a above the second plate thickness dividing line L2, and the second through hole 241 is formed on the side plate portion 225a below the first plate thickness dividing line L1.

[0107] A third through hole 242 for installing the backrest angle adjustment unit 230 is formed in the lower part of the side plate portion 225a in the seat back side frame 225A. The third through hole 242 avoids the first plate thickness dividing line L1 and the second plate thickness dividing line L2 and is formed in the lower part of the side plate portion 225a at a position lower than the first plate thickness dividing line L1.

[0108] In addition, when the vehicle seat device of this embodiment is arranged in the vehicle compartment on the right side in the vehicle width direction, as shown in FIG. Fig.16 As shown, an airbag module 247 is mounted on the right seat back side frame 225A of the pair of left and right seat back side frames 225A. In addition, when the vehicle seat device is arranged in the vehicle compartment on the left side in the vehicle width direction, the above-mentioned airbag module 247 is mounted on the left seat back side frame 225A of the pair of left and right seat back side frames 225A. In order to cope with the arrangement on either side of the left and right sides in the vehicle width direction in the vehicle compartment, the pair of left and right seat back side frames 225A are formed to be symmetrical, and the same reference numerals are attached to the corresponding parts in the figure.

[0109] exist Fig.19In the figure, the airbag module 247 includes: a box-shaped module housing 248, which is flat in the vehicle width direction; a gas generator 249, which is housed in the module housing 248; a retainer 250, which is used to retain the gas generator 249; an airbag 251, which can be rapidly inflated by the high-pressure gas from the gas generator 249 and is connected to the gas generator 249; and a retaining bag 252, which can usually keep the airbag 251 in a folded state and can immediately break when the airbag 251 is inflated.

[0110] In addition, the side plate portion 225a of the seat back side frame 225A is formed with a fourth through hole 243 and a fifth through hole 244 for mounting the airbag 251, and a pair of bolts 254 implanted in the retainer 250 penetrate the module housing 248 and are inserted into the fourth through hole 243 and the fifth through hole 244, and nuts 255 abutting and engaging with the inner surface of the side plate portion 225a are screwed together with the bolts 254. That is, the airbag 251 is mounted on the side plate portion 225a via the gas generator 249 and the retainer 250 by each of the pair of bolts 254 and the nut 255.

[0111] The fourth through hole 243 and the fifth through hole 244 are formed on the side plate portion 225a avoiding the first plate thickness boundary line L1 and the second plate thickness boundary line L2. In this embodiment, the fourth through hole 243 is formed on the side plate portion 225a below the second plate thickness boundary line L2 and above the second reinforcing portion 238, and the fifth through hole 244 is formed on the side plate portion 225a between the first plate thickness boundary line L1 and the second plate thickness boundary line L2 and between the second reinforcing portion 238 and the third reinforcing portion 239. That is, the airbag 251 is installed at a portion of the side plate portion 225a of the side frame where the plate thickness is the same between the first plate thickness boundary line L1 and the second plate thickness boundary line L2.

[0112] The deployment of the airbag 251 is suppressed by the inner reinforcing lining cloth 256 and the outer reinforcing lining cloth 257. One end of the inner reinforcing lining cloth 256 is sandwiched between the inner front portion of the module housing 248 and the inner surface of the seat back side frame 225A, and a resin mounting member 258 fixed to one end of the inner reinforcing lining cloth 256 is elastically engaged with the sixth through hole 245 and the seventh through hole 246 formed in the side plate portion 225a of the seat back side frame.

[0113] The sixth through hole 245 and the seventh through hole 246 are formed in a rectangular shape on the side plate portion 225a at a position avoiding the first plate thickness boundary line L1 and the second plate thickness boundary line L2. In this embodiment, the sixth through hole 245 is formed on the side plate portion 22 below the second plate thickness boundary line L2 and above the second reinforcement portion 238 adjacent to the fourth through hole 243, and the seventh through hole 246 is formed on the side plate portion 225a between the first plate thickness boundary line L1 and the second plate thickness boundary line L2, below the third reinforcement portion 239 and adjacent to the second through hole 241. That is, the inner reinforcing lining cloth 256 is fixed to the portion of the side plate portion 225a of the seat back side frame 225A where the plate thickness is the same between the first plate thickness boundary line L1 and the second plate thickness boundary line L2.

[0114] A locking hook 259 is fixed to one end of the outer reinforcing cloth 257 by sewing, and the locking hook 259 is engaged with the rear flange portion 225 c of the seat back side frame 225A at the rear of the module housing 248 .

[0115] The inner reinforcing lining cloth 256 and the outer reinforcing lining cloth 257 are arranged in a manner of clamping the module shell 248 from the inside and outside, overlapping each other on the outside of the front end portion of the module shell 248, extending forward in the front-rear direction of the vehicle in a gap 261 formed between the backrest pad 214a and the raised portion pad 214b of the seat back 214, and being sewn to the backrest pad skin 214aa and the raised portion pad skin 214ba.

[0116] An auxiliary member 263, which is formed into a linear shape by bending a metal bar, is fixed to the seat back side frame 225A on the side where the air bag module 247 is not mounted, of the pair of left and right seat back side frames 225A, and functions as a reinforcing member for correcting the shape of the seat back frame 216. The auxiliary member 263 protrudes forward from the seat back side frame 225A and is fixed to the seat back side frame 225A. The auxiliary member 263 can bear a load from the occupant when the occupant sits on the assembled vehicle seat, and the load may act on the seat back side frame 225A by the auxiliary member 263. Therefore, the auxiliary component 263 is fixed to the seat back side frame 225A while avoiding the first plate thickness dividing line L1 and the second plate thickness dividing line L2, and the auxiliary component 263 avoids contact with the seat back side frame 225A at the second plate thickness dividing line L2 while crossing the second plate thickness dividing line L2 and being fixed to the front flange portion 225b of the seat back side frame 225A.

[0117] exist Fig. 20 In the embodiment, the cushion side frame 218 in the cushion frame 215 has a substantially U-shaped cross-sectional shape that is open to the inside and is formed by press forming of a metal plate so that the plate thickness changes at the plate thickness dividing lines arranged at a plurality of positions in the longitudinal direction of the cushion side frame 218. In the present embodiment, the third plate thickness dividing line L3 and the fourth plate thickness dividing line L4 are set on the cushion side frame 218. Furthermore, the third plate thickness dividing line L3 and the fourth plate thickness dividing line L4 are set at positions that avoid the connection portion where the disc frame 219 and the rear pipe 220 are connected to the cushion side frame 218. The third plate thickness dividing line L3 is arranged at a position close to the rear of the cushion side frame 218, and the fourth plate thickness dividing line L4 is arranged in front of the third plate thickness dividing line L3 and at a middle position in the longitudinal direction of the cushion side frame 218.

[0118] exist Fig.21 In the embodiment, the plate thickness t5 of the cushion side frame 218 between the third plate thickness dividing line L3 and the fourth plate thickness dividing line L4 is smaller than the plate thickness t4 of the cushion side frame 218 rearward of the third plate thickness dividing line L3, and the plate thickness t6 of the cushion side frame 218 forward of the fourth plate thickness dividing line L4 is smaller than the plate thickness t5. In this way, the cushion side frame 218 is formed to be gradually thinner in thickness as it approaches the front.

[0119] Next, the function of the first embodiment will be described. The seat back side frame 225A of the seat back frame 216 is formed into a shape in which the plate thickness changes at the first plate thickness dividing line L1 and the second plate thickness dividing line L2, wherein the first plate thickness dividing line L1 and the second plate thickness dividing line L2 are arranged at a plurality of positions (two positions in the present embodiment) in the longitudinal direction of the seat back side frame 225A so as to avoid the connection portion with the headrest mounting bracket 226 and the lower frame 227. The seat cushion side frame 218 of the seat cushion frame 215 is formed into a shape in which the plate thickness changes at the third plate thickness dividing line L3 and the fourth plate thickness dividing line L4, wherein The third plate thickness dividing line L3 and the fourth plate thickness dividing line L4 are arranged at multiple positions (two positions in the present embodiment) in the length direction of the seat cushion side frame 218 to avoid the connection parts with the disc frame 219 and the rear tube 220. Therefore, in the seat back frame 216 and the seat cushion frame 215, the required strength of the seat back side frame 225A and the seat cushion side frame 218 can be ensured while suppressing the weight increase, and the rigidity of the connection part of the seat back side frame 225A and the headrest mounting bracket 226 and the lower frame 227 and the rigidity of the connection part of the seat cushion side frame 218 and the disc frame 219 and the rear tube 220 can be avoided.

[0120] In addition, a second reinforcement portion 238 and a third reinforcement portion 239 are provided on the seat back side frame 225A at a position avoiding the first plate thickness dividing line L1 and the second plate thickness dividing line L2. The second reinforcement portion 238 and the third reinforcement portion 239 extend in a direction intersecting the length direction of the seat back side frame 225A and bulge inward or outward. Therefore, the rigidity of the connection portion between the seat back side frame 225A and the headrest mounting bracket 226 and the lower frame 227 is not affected, and the strength of the seat back side frame 225A can be further increased.

[0121] In addition, the auxiliary component 263 that performs a reinforcing function avoids contact with the seat back side frame 225A at the second plate thickness dividing line L2, and at the same time crosses the second plate thickness dividing line L2 and is fixed to the seat back side frame 225A, thereby being able to increase the rigidity of the seat back side frame 225A at the second plate thickness dividing line L2.

[0122] In addition, on the seat back side frame 225A, the first reinforcement portion 237 is arranged across the second plate thickness dividing line L2, thereby being able to improve the rigidity of the seat back side frame 225A at the second plate thickness dividing line L2, wherein the first reinforcement portion 237 bulges inward or outward along the length direction of the seat back side frame 225A.

[0123] In addition, the seat back side frame 225A is formed with: a first through hole 240 and a second through hole 241 for mounting a back side pressure receiving member 234 as a mounting component; a third through hole 242 for mounting a back angle adjustment unit 230 as a mounting component; a fourth through hole 243 and a fifth through hole 244 for mounting an airbag 251 as a mounting component; a sixth through hole 245 and a seventh through hole 246 for mounting an airbag 251 as a mounting component. The reinforcing lining 256 on the inner side of the component, the first plate thickness dividing line L1 and the second plate thickness dividing line L2 are set to avoid the first to seventh through holes 240 to 246. Therefore, the first plate thickness dividing line L1 and the second plate thickness dividing line L2 will not affect the installation rigidity of the backrest side pressure component 234, the backrest angle adjustment unit 230, the airbag 251 and the inner reinforcing lining 256 to the seat back side frame 225A.

[0124] Furthermore, since the airbag 251 is mounted at a portion of the seat back side frame 225A where the plate thickness is constant, the rigidity of the portion of the seat back side frame 225A where the plate thickness is constant can be increased.

[0125] Furthermore, the inner reinforcing cloth 256 for suppressing the deployment of the airbag 251 is fixed to the portion of the seat back side frame 225A where the plate thickness is uniform. Therefore, the deployment of the airbag 251 can suppress the influence on the first plate thickness boundary line L1 and the second plate thickness boundary line L2.

[0126] In addition, the auxiliary component 263, which can bear the load from the occupant when the occupant is seated, avoids the first plate thickness dividing line L1 and the second plate thickness dividing line L2 and is fixed to the seat back side side frame 225A, thereby preventing the load from the auxiliary component 263 from affecting the plate thickness dividing line portion of the seat back side side frame 225A.

[0127] In addition, a backrest side pressure-receiving component 234 that elastically deforms by receiving the load of the seat occupant is installed at a position of the seat back side frame 225A that avoids the first plate thickness dividing line L1 and the second plate thickness dividing line L2. Therefore, it is possible to suppress the load from the backrest side pressure-receiving component 234 from affecting the plate thickness dividing line portion of the seat back side frame 225A.

[0128] One side reference Fig. 22 While describing the second embodiment of the present invention, only portions corresponding to those of the first embodiment described above are denoted by the same reference numerals and their detailed descriptions are omitted.

[0129] The side plate portion 225a of the seat back side side frame 225B is formed so that the plate thickness changes at the first plate thickness dividing line L1 and the second plate thickness dividing line L2, and the thickness gradually becomes thinner as it moves upward. The side plate portion 225a is provided with a fourth reinforcement portion 267 and a second reinforcement portion 238 that bulge inward or outward. The fourth reinforcement portion 267 has an inclined portion 267a inclined forward and downward at the lower portion, extends in the vertical direction along the rear edge of the side plate portion 225a, and is provided on the side plate portion 225a. In addition, the second reinforcement portion 238 extends in a direction intersecting with the length direction of the seat back side frame 225B, and extends from the middle portion in the up-down direction of the fourth reinforcement portion 267 toward the front in the front-rear direction of the vehicle, and is arranged on the side plate portion 225a. In the present embodiment, the fourth reinforcement portion 267 and the second reinforcement portion 238 are formed in a manner that bulges inward when the seat back side frame 225B is press-processed.

[0130] The fourth reinforcement portion 267 is provided on the side plate portion 225a such that the inclined portion 267a crosses the first plate thickness boundary line L1 and the fourth reinforcement portion 267 crosses the first plate thickness boundary line L1 and the second plate thickness boundary line L2.

[0131] According to the second embodiment, the second reinforcement portion 238 is provided in the seat back side frame 225B at a position avoiding the first plate thickness boundary line L1 and the second plate thickness boundary line L2, so that the seat back side frame 225B and the headrest mounting bracket 226 (see Fig.16 ) and the lower frame 227 (refer to Fig.16 ) and can further increase the strength of the seat back side side frame 225B, wherein the second reinforcement portion 238 extends in a direction intersecting with the length direction of the seat back side side frame 225B and bulges inwardly or outwardly.

[0132] In addition, on the seat back side frame 225B, the fourth reinforcement portion 267 extending along the length direction of the seat back side frame 225B and bulging inward or outward is arranged across the first plate thickness dividing line L1 and the second plate thickness dividing line L2, thereby being able to increase the rigidity of the seat back side frame 225B at the first plate thickness dividing line L1 and the second plate thickness dividing line L2.

[0133] One side reference Fig.23 While the third embodiment of the present invention will be described, only the parts corresponding to those of the first and second embodiments described above are denoted by the same reference numerals and the detailed description will be omitted.

[0134] The side plate portion 225a of the seat back side frame 225C is formed so that the plate thickness changes at the first plate thickness dividing line L1 and the second plate thickness dividing line L2, and the thickness gradually becomes thinner as it moves upward. The side plate portion 225a is provided with a fourth reinforcement portion 267 that bulges inward or outward, a fifth reinforcement portion 268, and a second reinforcement portion 238. The fifth reinforcement portion 268 extends forward in the vehicle front-rear direction from the base end portion of the inclined portion 267a of the fourth reinforcement portion 267 in a direction intersecting the longitudinal direction of the seat back side frame 225C, and is provided on the side plate portion 225a. In addition, the second reinforcement portion 238 extends in a direction intersecting with the length direction of the seat back side frame 225C and is arranged on the side plate portion 225a. In the present embodiment, the fourth reinforcement portion 267, the fifth reinforcement portion 268 and the second reinforcement portion 238 are formed in a manner that bulges inward when the seat back side frame 225C is press-processed.

[0135] Similar to the second reinforcement portion 238 , the fifth reinforcement portion 268 is provided on the side plate portion 225 a at a position avoiding the first plate thickness boundary line L1 and the second plate thickness boundary line L2 .

[0136] According to the third embodiment, the fifth reinforcement portion 268 and the second reinforcement portion 238 are provided at positions of the seat back side frame 225C avoiding the first plate thickness boundary line L1 and the second plate thickness boundary line L2, so that the seat back side frame 225C and the headrest mounting bracket 226 (see FIG. 2 ) can be free from the need for contact. Fig.16 ) and the lower frame 227 (refer to Fig.16 ) and can further increase the strength of the seat back side side frame 225C, wherein the fifth reinforcement portion 268 and the second reinforcement portion 238 extend in a direction intersecting the length direction of the seat back side side frame 225C and bulge inwardly or outwardly.

[0137] In addition, on the seat back side frame 225C, the fourth reinforcement portion 267 extending along the length direction of the seat back side frame 225C and bulging inward or outward is arranged across the first plate thickness dividing line L1 and the second plate thickness dividing line L2, thereby improving the rigidity of the seat back side frame 225C at the first plate thickness dividing line L1 and the second plate thickness dividing line L2.

[0138] One side reference Fig.24 While a fourth embodiment of the present invention will be described, only portions corresponding to those of the first to third embodiments described above are denoted by the same reference numerals and shown in the drawings, and detailed descriptions thereof will be omitted.

[0139] The side plate portion 225a of the seat back side frame 225D is formed so that the plate thickness changes at the first plate thickness dividing line L1 and the second plate thickness dividing line L2, and the thickness gradually becomes thinner as it approaches upward. The side plate portion 225a is provided with the 6th to 11th reinforcement portions 269, 270, 271, 272, 273, and 274 that bulge inward or outward. In the present embodiment, these reinforcement portions 269 to 274 are formed in a manner that bulges inward when the seat back side frame 225D is press-processed.

[0140] The 6th reinforcement 269, the 7th reinforcement 270 and the 8th reinforcement 271 extend in the up-down direction along the rear edge of the side plate portion 225a, the 6th reinforcement 269 is arranged on the side plate portion 225a above the 2nd plate thickness dividing line L2, the 7th reinforcement 270 is arranged on the side plate portion 225a between the 1st plate thickness dividing line L1 and the 2nd plate thickness dividing line L2, and the 8th reinforcement 271 is arranged on the side plate portion 225a at a position lower than the 1st plate thickness dividing line L1.

[0141] In addition, the 9th reinforcement portion 272, the 10th reinforcement portion 273 and the 11th reinforcement portion 274 extend forward in the front-rear direction of the vehicle in a direction intersecting the length direction of the seat back side frame 225D, and are separately arranged from the 6th reinforcement portion 269, the 7th reinforcement portion 270 and the 8th reinforcement portion 271, the 9th reinforcement portion 272 and the 10th reinforcement portion 273 are arranged on the side plate portion 225a between the first plate thickness dividing line L1 and the second plate thickness dividing line L1, and the 11th reinforcement portion 274 is arranged on the side plate portion 225a at a position lower than the first plate thickness dividing line l1.

[0142] According to the fourth embodiment, the sixth to eleventh reinforcement portions 269 to 274 are provided on the side plate portion 225a at positions avoiding the first plate thickness dividing line L1 and the second plate thickness dividing line L2 in the seat back side side frame 225D, so that the seat back side side frame 225D and the headrest mounting bracket 226 (see Fig.16 ) and the lower frame 227 (refer to Fig.16 ) has an impact on the rigidity of the connection portion and can further increase the strength of the seat back side side frame 225D.

[0143] Although the embodiments of the present invention have been described above, the present invention is not limited to the above embodiments, and various design changes can be made without departing from the scope of the present invention described in the claims.

[0144] <Implementation method of solution to the third technical problem> Next, refer to the attached Figure 1 In the following description, "front and rear", "left and right", and "up and down" refer to directions viewed by a seated person when the seated person is in a posture facing forward in the front-rear direction of the vehicle.

[0145] First, in Fig.25 In the figure, the seat frame 312 includes: a cushion frame 315, which supports a seat cushion (not shown); and a seat back frame 316, which supports a seat back (not shown) arranged above the seat cushion and is connected to the seat cushion frame 315, and a height adjustment mechanism 317 capable of adjusting the height of the seat cushion frame 315 is provided between the seat cushion frame 315 and the slide rail 311, wherein the seat frame 312 can move along a pair of slide rails 311, and the pair of slide rails 311 are spaced apart and arranged parallel to each other in the vehicle width direction and extend in a straight line.

[0146] The seat cushion frame 315 has: a pair of seat cushion side frames 318, which are arranged at positions separated from each other in the vehicle width direction and extend in a straight line in the vehicle front-rear direction; a disc frame 319, which connects the front ends of these seat cushion side frames 318; and a rear pipe 320, which connects the rear ends of a pair of the seat cushion side frames 318.

[0147] A seat cushion side pressure receiving member 321 is provided between the disc frame 319 and the rear tube 320. The seat cushion side pressure receiving member 321 is elastically deformed by receiving a load from a seated person through the seat cushion. The seat cushion side pressure receiving member 321 includes a plurality of (four in this embodiment) seat springs 322 formed by bending a metal wire in a zigzag shape so as to extend in a zigzag manner to the left and right. The seat springs 322 are arranged so that adjacent seat springs 322 are symmetrical to each other. The front ends of the plurality of seat springs 322 are respectively engaged with a stopper 323 provided on the disc frame 319 in the seat frame 312. In addition, the rear ends of the adjacent seat springs 322 are engaged with the rear tube 320 of the seat frame 312 and connected together by a resin rear end connecting member 324 integrally formed with the seat springs by insert molding, and the rear end connecting member 324 is formed so as to cover the rear tube 320.

[0148] The seat back frame 316 includes: a pair of seat back side frames 325A, which are arranged at positions separated from each other in the vehicle width direction and extend in the up-down direction; a headrest mounting bracket 326, which connects the upper parts of these seat back side frames 325A; and a lower frame 327, which connects the lower end parts of a pair of the seat back side frames 325A.

[0149] Refer to Fig.26 and Fig. 27 The seat back side frame 325A integrally has a side plate portion 325a, a front flange portion 325b, a rear flange portion 325c and a lower flange portion 325d, and is formed by press forming of a metal sheet, wherein the front flange portion 325b extends inward from the front edge portion of the side plate portion 325a; the rear flange portion 325c extends inward from the rear edge portion of the side plate portion 325a; and the lower flange portion 325d extends inward from the lower edge portion of the side plate portion 325a.

[0150] Refer to Fig.28 A bracket support portion 325e is provided on the upper portion of the seat back side frame 325A, and the bracket support portion 325e is formed by folding the front flange portion 325b toward the side close to the side plate portion 325a, and bending the rear flange portion 325c toward the front in the vehicle front-rear direction into an open approximately C shape.

[0151] The headrest mounting bracket 326 is formed by opening a pipe downward and bending it into a substantially U-shape, and both ends of the headrest mounting bracket 326 are fitted and fixed to the bracket support portion 325e of the upper portion of the seat back side frame 325A. In addition, a pair of cylindrical headrest support members 328 are fixed to the headrest mounting bracket 326.

[0152] Refer again Fig.25 A connecting bracket 329 is fastened to the rear end of the left and right pair of the seat cushion side frames 318, respectively, and the lower end of the left and right pair of the seat back side frames 325A is connected to each connecting bracket 329 through a back angle adjustment unit 330. The rotation shaft 331 of the back angle adjustment unit 330 penetrates the lower frame 327 fixed to the lower end of the left and right pair of the seat back side frames 325A, and is thus installed at the lower end of the left and right pair of the seat back side frames 325A. The tilting angle of the seat back frame 316 relative to the seat frame 312 can be adjusted by the action of the back angle adjustment unit 330.

[0153] In addition, between the left and right seat back side frames 325A, a backrest side pressure receiving member 334 is disposed, which can be elastically deformed by receiving the load of the seat occupant through the seat back. The backrest side pressure receiving member 334, which is elastically deformable by resin or the like, is bridged between the left and right seat back side frames 325A via an upper connecting wire 335 and a lower connecting wire 336.

[0154] The seat back side side frame 325A has a reference plate thickness ta1 in a first reference plate thickness area A1 and an increased plate thickness tb1 in a first plate thickness increase area B1 that is thicker than the reference plate thickness ta1, wherein the first reference plate thickness area A1 includes at least the side plate portion 325a; the first plate thickness increase area B1 includes at least the front flange portion 325b, the rear flange portion 325c and the lower flange portion 325d, and the seat back side side frame 325A is formed by changing the plate thickness in the first reference plate thickness area A1 and the first plate thickness increase area B1.

[0155] In this embodiment, the first plate thickness increased region B1 is set to include the front flange portion 325b, the rear flange portion 325c, the lower flange portion 325d and a portion of the outer edge of the side plate portion 325a. Fig. 27 and Fig.28 As shown, the first plate thickness increased area B1 is set by a specified portion of the outer edge portion of the side plate portion 325a, wherein the specified portion refers to a portion that is integrally connected to the front flange portion 325b, the rear flange portion 325c and the lower flange portion 325d in a curved shape.

[0156] In addition, a backrest angle adjustment unit mounting portion 332 is provided at the lower end portion of the side plate portion 325a. The backrest angle adjustment unit mounting portion 332 has a first through hole 340 for mounting the backrest angle adjustment unit 330 as a mounting component. The backrest angle adjustment unit mounting portion 332 is surrounded by a portion of the first plate thickness increased area B1 from three directions: front, rear and bottom. The backrest angle adjustment unit 330 is surrounded by the first plate thickness increased area B1 from three directions.

[0157] Furthermore, the backrest angle adjustment unit mounting portion 332 is formed to be thicker than the increased plate thickness tb1 of the first plate thickness increased region B1 , that is, the backrest angle adjustment unit mounting portion 332 is formed to have a plate thickness tc thicker than the increased plate thickness tb1 .

[0158] In addition, a reinforcement portion that bulges inward or outward is provided in a part of the portion of the side plate portion 325a that is included in the first plate thickness increased area B1. In the present embodiment, a first reinforcement portion 337 that extends in the up-down direction along the rear flange portion 325c is provided in a portion of the rear edge portion of the side plate portion 325a that is integrally connected to the rear flange portion 325c in a curved shape and is included in the first plate thickness increased area B. The first reinforcement portion 337 is formed in a manner that bulges inward when the seat back side frame 325A is press-processed.

[0159] In addition, the side plate portion 325a is provided with a reinforcing portion that connects the mutually separated portions in the first plate thickness increased region B1. In the present embodiment, the side plate portion 325a is provided with a second reinforcing portion 338 and a third reinforcing portion 339 that connect the front side edge portion and the rear side edge portion of the side plate portion 325a. The second reinforcing portion 338 extends from the middle portion in the up-down direction of the first reinforcing portion 337 to the front in the vehicle front-back direction and is provided on the side plate portion 325a. The third reinforcing portion 339 extends from the lower end portion of the first reinforcing portion 337 to the front in the vehicle front-back direction while being slightly inclined forward and upward and is provided on the side plate portion 325a. These second reinforcing portion 338 and the third reinforcing portion 339 are formed so as to bulge inward when the seat back side frame 325A is press-worked.

[0160] Furthermore, in a portion of the side plate portion 325 a of the seat back side frame 325A included in the first reference thickness region A1 , second to seventh through holes 341 , 342 , 343 , 344 , 345 , and 346 are formed in addition to the first through hole 340 .

[0161] The second through hole 341 and the third through hole 342 are through holes for installing the upper connecting wiring 335 and the lower connecting wiring 336 of the backrest side pressure component 334, the fourth through hole 343 and the fifth through hole 344 are through holes for installing the airbag module 347, which is installed on the seat back side side frame 325A arranged on the door side in a pair of left and right seat back side frames 325A, and the sixth through hole 345 and the seventh through hole 346 are through holes for installing a reinforcing lining cloth (not shown) for inhibiting the deployment of the airbag.

[0162] exist Fig.29 and Fig.30In the seat cushion frame 315, the seat cushion side frame 318 integrally has a side plate portion 318a, an upper flange portion 318b and a lower flange portion 318c, which are formed by press forming of a metal sheet, wherein the upper flange portion 318b extends inward from the upper edge of the side plate portion 318a; and the lower flange portion 318c extends inward from the lower edge of the side plate portion 318a.

[0163] The cushion side frame 318 has a reference plate thickness ta2 in the second reference plate thickness area A2 and an increased plate thickness tb2 in the second plate thickness increase area B2 which is thicker than the reference plate thickness ta2, wherein the second reference plate thickness area A2 includes at least the side plate portion 318a; the second plate thickness increase area B2 includes at least the upper flange portion 318b and the lower flange portion 318c, and the cushion side frame 318 is formed by changing the plate thickness in the second reference plate thickness area A2 and the second plate thickness increase area B2.

[0164] In this embodiment, the second plate thickness increased area B2 is set to include the upper flange portion 318b, the lower flange portion 318c and a portion of the outer edge of the side plate portion 318a, and the second plate thickness increased area B2 is set in a manner including a specified portion, wherein the specified portion refers to a portion of the outer edge of the side plate portion 318a that is integrally connected to the upper flange portion 318b in a curved shape and a portion that is integrally connected to the lower flange portion 318c in a curved shape.

[0165] Next, the function of the first embodiment is described. At least one of the seat cushion frame 315 and the seat back frame 316, in this embodiment, the seat back side frame 325 of the seat back frame 316 and the seat cushion side frame 318 of the seat cushion frame 315 have reference plate thicknesses ta1 and ta2 of the first reference plate thickness region A1 and the second reference plate thickness region A2, and increased plate thicknesses tb1 and tb2 thicker than the reference plate thicknesses ta1 and ta2 in the first plate thickness increased region B1 and the second plate thickness increased region B2, wherein the first reference plate thickness region A1 and the second reference plate thickness region A2 have increased plate thicknesses tb1 and tb2 thicker than the reference plate thicknesses ta1 and ta2. At least side plate portions 325a, 318a are included, the first plate thickness increase area B1 includes at least a front flange portion 325b and a rear flange portion 325c, the second plate thickness increase area B2 includes at least an upper flange portion 318b and a lower flange portion 318c, and the plate thickness is changed in the first reference plate thickness area A1 and the second reference plate thickness area A2, and the first plate thickness increase area B1 and the second plate thickness increase area B2 to form, thereby being able to suppress the weight increase of the seat back side side frame 325 and the seat cushion side side frame 318 as much as possible, and at the same time being able to improve the rigidity of these side frames 325, 328.

[0166] In addition, the first plate thickness increased area B1 and the second plate thickness increased area B2 are set in a manner including specified parts, so that the rigidity of the seat back side side frame 325 and the seat cushion side side frame 318 can be further improved, wherein the specified parts refer to the outer edge parts of the side plate parts 325a, 318a that are integrally connected to the front flange part 325b, the rear flange part 325b and the side flange part 325c in a curved shape, and the parts that are integrally connected to the upper flange part 318b and the lower flange part 318c in a curved shape.

[0167] In addition, in the seat back side frame 325, a portion of the first plate thickness increased area B1 surrounds the specified back angle adjustment unit 330 from three directions, thereby achieving an improved rigidity of the mounting portion of the back angle adjustment unit 330, wherein the back angle adjustment unit 330 is a mounting component mounted on the side plate portion 325a.

[0168] In addition, a backrest angle adjustment unit mounting portion 332 for mounting the backrest angle adjustment unit 330 is provided on the side plate portion 325a of the seat back frame side frame 325. The backrest angle adjustment unit mounting portion 332 is formed to be thicker than the increased plate thickness tb1 of the first plate thickness increased area B1, thereby improving the mounting rigidity of the backrest angle adjustment unit 330.

[0169] Furthermore, a first reinforcement portion 337 that bulges inward or outward is provided in a portion of the side plate portion of the seat back frame side side frame 325 included in the first increased thickness region A1, thereby further improving the rigidity of the side plate portion 325a.

[0170] In addition, a second reinforcement portion 338 and a third reinforcement portion 339 are provided on the side plate portion 325a, and the second reinforcement portion 338 and the third reinforcement portion 339 connect the components separated from each other in the first plate thickness increased area A1 in the seat back frame side frame 325, so that the rigidity of the seat back frame side frame 325 is further improved.

[0171] Furthermore, in the seat back frame-side side frame 325 , the first to seventh through holes 340 to 346 are formed in the side plate portion 325 a in the portion included in the first reference thickness region A1 , so that the processing accuracy of the first to seventh through holes 340 to 346 can be improved.

[0172] One side reference Fig.31 While describing the second embodiment of the present invention, only portions corresponding to those of the first embodiment described above are denoted by the same reference numerals and their detailed descriptions are omitted.

[0173] The side plate portion 325a of the seat back side frame 325B is provided with a fourth reinforcement portion 367 and a second reinforcement portion 338 that bulge inward or outward. The fourth reinforcement portion 367 has an inclined portion 367a inclined forward and downward at the lower portion, is included in the first plate thickness increase area A1, extends in the vertical direction along the rear flange portion 325c, and is provided on the side plate portion 325a. In addition, the second reinforcement portion 338 extends in a direction orthogonal to the longitudinal direction of the seat back side frame 325B, and extends from the middle portion in the vertical direction of the fourth reinforcement portion 367 to the front in the vehicle front-rear direction, and is provided on the side plate portion 325a. In this embodiment, the fourth reinforcement portion 367 and the second reinforcement portion 338 are formed in a manner of bulging inward when the seat back side frame 325B is press-worked.

[0174] According to the second embodiment as well, it is possible to achieve the same effects as those of the first embodiment described above.

[0175] One side reference Fig.32 While the third embodiment of the present invention will be described, only the parts corresponding to those of the first and second embodiments described above are denoted by the same reference numerals and the detailed description will be omitted.

[0176] The side plate portion 325a of the seat back side frame 325C is provided with a fourth reinforcement portion 367, a fifth reinforcement portion 368, and a second reinforcement portion 338 that bulge inward or outward. The fifth reinforcement portion 368 extends forward in the vehicle front-rear direction from the base end portion of the inclined portion 367a of the fourth reinforcement portion 367 in a direction intersecting the longitudinal direction of the seat back side frame 325C, and is provided on the side plate portion 325a. In addition, the second reinforcement portion 338 extends in a direction intersecting the longitudinal direction of the seat back side frame 325C, and is provided on the side plate portion 325a. In the present embodiment, the fourth reinforcement portion 367, the fifth reinforcement portion 368, and the second reinforcement portion 338 are formed in a manner that bulges inward when the seat back side frame 325C is press-worked.

[0177] According to the third embodiment as well, the same effects as those of the first and second embodiments described above can be obtained.

[0178] One side reference Fig.33 A fourth embodiment of the present invention will be described, with only portions corresponding to those of the first to third embodiments described above being denoted by the same reference numerals and not being described in detail.

[0179] The side plate portion 325a of the seat back side frame 325D is provided with a first reinforcement portion 337 and sixth to eighth reinforcement portions 369, 370, 371 that bulge inwardly or outwardly. In the present embodiment, these reinforcement portions 337, 369 to 371 are formed in a manner that bulges inwardly when the seat back side frame 325D is press-worked.

[0180] The sixth reinforcement portion 369 , the seventh reinforcement portion 370 , and the eighth reinforcement portion 371 extend in the vehicle front-rear direction at positions spaced apart from each other in the up-down direction, and are provided on the side plate portion 325 a .

[0181] According to the fourth embodiment as well, the same effects as those of the first to third embodiments described above can be obtained.

[0182] And, in Figure 34 to Figure 37. The fifth embodiment is shown in FIG. 1 . In the fifth embodiment, the left and right connecting brackets 329L and 329R are characterized in that their bases are fastened to the rear ends of the left and right pair of cushion side frames 318 by a plurality of bolts 391, respectively, and the lower ends of the left and right pair of seat back side frames 325A are connected by the left and right seat back angle adjustment units 330. In the fifth embodiment, similarly to the above-mentioned embodiment, the lower ends of the side plates 325a of the left and right seat back side frames 325A are provided with the back angle adjustment unit mounting portions 332, which have the first through holes 340 for mounting the back angle adjustment unit 330 as the mounting component, and are formed thickly so as to have a plate thickness tc thicker than the above-mentioned increased plate thickness tb1.

[0183] The left and right backrest angle adjustment units 330 respectively include: a base plate 330b, which is overlapped and fixed on the top of the connecting brackets 329L and 329R; a plate-shaped shell 330c, which is rotatably embedded and supported on the base plate 330b and is embedded and fixed in the first through hole 340; a locking mechanism not shown in the figure, which is arranged in the space between the shell 330c and the base plate 330b and can lock the shell 330c and the base plate 330b to each other or release the lock between each other; an operating lever 392, which is linked to the locking mechanism; a force applying device 330s, which applies force to the seat back frame 316 to make it tilt forward around the rotation axis 331 relative to the seat cushion frame 315, and the left and right locking mechanisms coordinate their actions through the rotation axis 331.

[0184] The urging device 330s includes: a coil spring 396, one end of which is locked to a locking piece 394 fixed to the connecting bracket 329L, 329R or the base plate 330b, and the other end of which is locked to a locking piece 395 fixed to the seat back side frame 325A; and a spring housing (not shown) that houses the coil spring 396. In addition, the operating lever 392 is linked to a locking mechanism on one side (right side in the example shown in the figure), and is normally elastically held at a predetermined standby position by the biasing force of a return spring (not shown).

[0185] In this way, the above-mentioned locking mechanism is the same as the locking mechanism of the above-mentioned known backrest angle adjustment unit, and can switch the above-mentioned locking or unlocking at any time by operating the operating lever 392. Through this switching, the relative rotation of the shell 330c and the base plate 330b with respect to each other (therefore, the tilting of the seat back frame 316 (side frame 325A) relative to the seat cushion frame 315 (side frame 318)) can be limited or the relative rotation of the shell 330c and the base plate 330b with respect to each other can be allowed, thereby arbitrarily adjusting the tilting angle of the seat back frame 316 relative to the seat cushion frame 315.

[0186] In addition, by Fig.36 and Fig.37 It can be seen that the joint surface between the top of the left and right connecting brackets 329L and 329R and the base plate 330b is offset to the outside by a predetermined amount relative to the joint surface between the base and the cushion side frame 318, and the offset amounts δ and δ' are different for the left and right connecting brackets 329L and 329R. That is, the above-mentioned offset δ of the connecting bracket 329R located on the same side as the operating lever 392 is set to be smaller to avoid the connecting bracket 329R and the operating lever 392 from interfering with each other, and the above-mentioned offset δ' of the connecting bracket 329L located on the opposite side is set to be larger.

[0187] In addition, a fragile portion 380L, 380R is provided in the middle portion between the base and the top of each connecting bracket 329L, 329R. When the vehicle is subjected to a rear surface collision (such as a rear-end collision), the fragile portion 380L, 380R is relatively easy to be crushed and deformed, thereby absorbing the impact. In the present embodiment, the fragile portion has a first ridge portion 381L, 381R and a second ridge portion 382L, 382R, respectively, and is formed in a V-shape or a Y-shape when viewed from the side. The first ridge portion 381L, 381R is formed by bending the middle portion of the connecting bracket 329L, 329R across the front-rear direction and forming a mountain-shaped cross section. The second ridge portion 382L, 382R extends obliquely forward and upward from the rear end portion or the middle portion of the first ridge portion 381L, 381R.

[0188] In order to adjust the strength, a plurality of extended ribs are extended from the fragile portions 380L and 380R. For example, first extended ribs b1L and b1R and second extended ribs b2L and b2R are extended from the lower ends of the middle portions of the first ribs 381L and 381R and the upper ends of the middle portions of the second ribs 382L and 382R. The bolt 391 at the lower end (i.e., the lower fixing portion of the connecting bracket 329L, 329R) extends along the same line toward the center of the backrest angle adjustment unit 330 (the welding ridge on the lower side). In addition, the third extended ridge portions b3L, b3R extend from the rear ends of the second ridge portions 382L, 382R, and the third extended ridge portions b3L, b3R extend toward the center of the backrest angle adjustment unit 330 (the welding ridge on the lower side).

[0189] Furthermore, the second ribs 382L and 382R are extended long toward the front bolts 391 (i.e., the front fixing parts of the connecting brackets 329L and 329R), and the fourth extended ribs b4L and b4R are extended from the front bolts 391 toward the center of the backrest angle adjustment unit 330 (the front welding ribs) from the front extended ends thereof. Furthermore, the third ribs 383L and 383R are formed along the rear end edges of the connecting brackets 329L and 329R, and the fifth extended ribs b5L and b5R are extended from the upper parts of the third ribs 383L and 383R at positions approximately symmetrical to the fourth extended ribs b4L and b4R across the center of the backrest angle adjustment unit 330. Thus, by combining at least a portion of the first to fifth extended ribs b1L, b1R to b5L, b5R with the fragile portions 380L, 380R, the directionality and strength of the connection brackets 329L, 329R can be easily adjusted.

[0190] By making the shapes and positions of the fragile portions 380L, 380R specially provided in the middle portions of the left and right connecting brackets 329L, 329R and the extended ridge portions b1L, b1R to b5L, b5R connected thereto different, or making the above-mentioned offset amounts δ, δ′ between the base and the top of the left and right connecting brackets 329L, 329R different, the deformability of the left and right fragile portions 380L, 380R can be changed. Therefore, even when the impact load is not evenly applied to the left and right sides of the vehicle seat during a rear surface collision, the deformation form of the left and right connecting brackets 329L, 329R can be adjusted.

[0191] The embodiments of the present invention have been described above, but the present invention is not limited to the above-described embodiments, and various design changes can be made within the scope of the present invention without departing from the scope of the claims.

[0192] <Method of implementing the solution to the fourth technical problem> In the following description, front and rear, left and right, and up and down refer to directions viewed by a passenger seated on a vehicle seat in a normal sitting posture (basic posture during driving).

[0193] Fig.38 The overall structure of a vehicle seat (vehicle seat) according to one embodiment of the present invention is schematically shown. The vehicle seat 411 includes: a slide rail 413 connected to a floor 412 that functions as one structural element of a monocoque structure of a vehicle, for example; a seat cushion 414 that is supported on the slide rail 413 in a manner that allows movement in the front-rear direction and supports the buttocks and thighs of the occupant; a seat back 415 that is connected to the seat cushion 414 in a manner that allows swinging in the front-rear direction around a swing axis SX and supports the back of the occupant; and a headrest 416 that is supported at the upper end of the seat back 415 and supports the head of the occupant. The seat cushion 414, the seat back 415, and the headrest 416 respectively include skin materials 414a, 415a, and 416a that cover the padding inside. The skin materials 415a and 416a are closely attached to the outer surface of the padding along the recessed portion of the padding by the action of the suspension wire 417. The details of the padding will be described later. The vehicle seat 411 is configured to be used as a left seat. When the vehicle seat 411 is used as a right seat, the vehicle seat 411 can be switched left and right.

[0194] The seat cushion 414 has a side cover 418. A first operating lever (operating member) 419a and a second operating lever (operating member) 419b are mounted on the side cover 418. The first operating lever 419a is supported so as to be able to swing freely around an axis parallel to the rotation axis SX. When the first operating lever 419a is pulled upward around the axis, the seat cushion 414 and the seat back 415 move upward. When the first operating lever 419a is pressed downward around the axis, the seat cushion 414 and the seat back 415 move downward. The second operating lever 419b is supported so as to be able to swing freely around the rotation axis SX. When the second operating lever 419b is pulled upward around the swing axis SX, the lock between the seat cushion 414 and the seat back 415 around the swing axis SX is released. The seat back 415 is allowed to swing around the swing axis SX. The seat back 415 is driven forward around the swing axis SX by the action of the spring. When an external force is applied to the seat back 415 backward around the swing axis SX against the spring force, the seat back 415 can be driven backward around the swing axis SX. When the second operating lever 419b is released from the pulling force around the swing axis SX, a lock around the swing axis SX is established between the seat cushion 414 and the seat back 415. The angle of the seat back 415 around the swing axis SX can be fixed.

[0195] A third operating rod (operating member) 419c is mounted on the seat cushion 414. The third operating rod 419c is supported so as to be freely swingable around an axis parallel to the swing axis SX. When the third operating rod 419c is pulled upward around the axis, the lock between the seat cushion 414 and the slide rail 413 is released. The seat cushion 414 is allowed to move linearly on the slide rail 413. When an external force is applied to the seat cushion 414 in a forward or backward direction, the seat cushion 414 can be displaced along the slide rail 413. When the third operating rod 419c is released from the pulling force around the axis, a lock is established between the seat cushion 414 and the slide rail 413. The position of the seat cushion 414 on the slide rail 413 in the front-to-back direction can be fixed.

[0196] The headrest 416 is fixed to a headrest support 421 extending upward from the upper end of the seat back 415. The headrest support 421 is supported by the seat back 415 so as to be freely displaceable in the axial direction in the vertical direction. The height of the headrest 416 can be adjusted according to the displacement of the headrest support 421.

[0197] like Fig.39 As shown, the vehicle seat 411 has a seat frame 423 that supports a cushion. The seat frame 423 has a cushion frame 424 that supports the cushion of the seat cushion 414; a seat back frame 425 that is connected to the cushion frame 424 in a manner that can swing around a swing axis SX and supports the cushion of the seat back 415; and a base frame 426 that is guided by the slide rail 413 in a manner that can freely move forward and backward in the longitudinal direction and supports the cushion frame 424 on the slide rail 413. The cushion frame 424 is connected to the base frame 426 by a link mechanism 427. The link mechanism 427 has a link member 428, one end of which is connected to the base frame 426 in a manner that can freely rotate around a horizontal axis FH extending in the left-right direction parallel to the swing axis SX, and the other end of which is connected to the cushion frame 424 in a manner that can freely rotate around a horizontal axis SH extending in the left-right direction parallel to the horizontal axis FH. The link member 428 guides the cushion frame 424 to move up and down relative to the base frame 426 about the horizontal axis FH.

[0198] The seat cushion frame 424 includes: a seat cushion side frame 424a extending side by side on each slide rail 413; a disc frame 424b connecting the seat cushion side frames 424a to each other at the front end of the seat cushion 414; and a connecting pipe 424c connecting the seat cushion side frames 424a to each other at the rear end of the seat cushion 414. A plurality of S-shaped springs (not shown) are arranged between the disc frame 424b and the connecting pipe 424c. Each S-shaped spring extends forward and backward in a zigzag shape. The zigzag shape is formed by staggered combination of wires extending in the front-back direction and wires extending in the left-right direction.

[0199] A manual forward and backward moving device 429 is mounted on the base frame 426. The third operating rod 419c is connected to the manual forward and backward moving device 429. The manual forward and backward moving device 429 switches between locking and unlocking the movement of the base frame 426 on the slide rail 413 in response to the swing of the third operating rod 419c.

[0200] A manual up-and-down moving device 431 is mounted on the cushion side frame 424a of the cushion frame 424. The manual up-and-down moving device 431 has a transmission mechanism 432, which is supported by the cushion side frame 424a and connected to the link mechanism 427. The transmission mechanism 432 is arranged on the outer side of the cushion side frame 424a, and causes the link member 428 to rotate relative to the cushion side frame 424a around the horizontal axis SH in response to the driving force transmitted from the first operating rod 419a around the axis. The transmission mechanism 432 may include, for example, a driving gear fixed to the swing shaft of the first operating rod 419a, and a driven gear fixed to the link member 428 around the horizontal axis SH.

[0201] The seat back frame 425 includes: left and right side frames 435, which are connected to the inner side of each seat cushion side frame 424a by a backrest angle adjustment unit (backrest angle adjustment mechanism) 434; a lower frame 436, which connects the lower ends of the side frames 435 to each other around the backrest angle adjustment unit 434; and an upper frame 437, which connects the upper ends of the side frames 435 to each other above the lower frame 436. The side frame 435 includes a plate-like portion 435a extending around the backrest angle adjustment unit 434 along a vertical plane orthogonal to the swing axis SX and extending upward from the vertical plane; a front wall 435b continuously and inwardly bent from the front edge of the plate-like portion 435a to form a curved region 438 extending in the vertical direction from the periphery of the backrest angle adjustment unit 434; and a rear wall 435c continuously and inwardly bent from the rear edge of the plate-like portion 435a to form a curved region 439 extending in the vertical direction from the periphery of the backrest angle adjustment unit 434. The rear wall 435c is formed with a side frame flange 441 continuously and forwardly bent from the inner end of the rear wall 435c. Each side frame 435 is formed of, for example, a single metal plate. A headrest support guide 442 is fixed to the upper frame 437, and the headrest support guide 442 supports the headrest support 421 in a manner that allows sliding in the up-down direction. The details of the upper frame 437 will be described later.

[0202] The backrest angle adjustment unit 434 has a rotating body 443, which is supported by the seat cushion frame 424 and the seat back frame 425 in a relatively freely rotatable manner. On one rotating body (here, the left rotating body) 443, a shaft body 444 is connected in a coaxial manner with the swing axis SX. The second operating lever 419b is fixed to the shaft body 444. In response to the rotation of the rotating body 443, the relative rotation between the seat cushion frame 424 and the seat back frame 425 is switched between locking and unlocking. The left and right backrest angle adjustment units 434 are connected to each other by a connecting shaft 445 as a connecting member. The connecting shaft 445 can rotate around the swing axis SX. The connecting shaft 445 transmits the rotation of the rotating body (here, the left rotating body) 443 on one side to the rotating body (here, the right rotating body) 443 on the other side. In this way, the operation of the second operating lever 419 b is transmitted from one of the backrest angle adjustment units 434 to the other of the backrest angle adjustment units 434 .

[0203] like Fig.40 As shown, the seat cushion 414 further includes a seat cushion pad 446, which is supported by the seat cushion frame 424 and covered by the skin material 414a. The seat back 415 further includes a seat back pad 447, which is supported by the seat back frame 425 and covered by the skin material 415a. The seat cushion pad 446 and the seat back pad 447 are formed of an elastic material such as polyurethane foam.

[0204] like Figure 41 to Figure 43 As shown, the lower frame 436 has: a back region 451, which is arranged behind the swing axis SX, is connected to the rear wall 435c of the side frame 435 from the rear, and connects the left and right side frames 435 to each other; and a reinforcement region 452, which is continuous from the lower edge of the back region 451, extends forward from the swing axis SX, and is connected to the front wall 435b from the rear. The reinforcement region 452 has a generatrix with a posture perpendicular to the plate-shaped portion 435a of the side frame 435, and is bent around the swing axis SX along the edge of the plate-shaped portion 435a. The torsional rigidity of the lower frame 436 around the swing axis SX can be improved by the action of the curved reinforcement region 452. The lower frame 436 is formed of, for example, a single metal plate.

[0205] The back region 451 includes a flat plate portion 451a extending along the first plane Pf, and a flange 451b which is continuous from the upper edge of the flat plate portion 451a and is bent forward. The upper edge of the flat plate portion 451a includes a first edge portion 453a extending from the left and right center position in the left and right directions parallel to the swing axis SX, a second edge portion 453b extending while bending upward from the left and right ends of the first edge portion 453a, and a third edge portion 453c extending from the upper end of the second edge portion 453b toward the outside in parallel to the swing axis SX and overlapping the side frame 35. The flange 451b is continuous at the first edge portion 453a and the second edge portion 453b, and is interrupted at the upper end of the second edge portion 453b and faces the side frame flange 441.

[0206] A weld mark 454 is formed at a position on the back region 451 that overlaps with the left and right side frames 435. Here, the weld mark 454 is composed of a weld ridge formed along the edge of the side frame 435. At the weld mark 454, the left and right side frames 435 are joined to the back region 451 of the lower frame 436. In addition, spot welding or laser welding can be used for welding.

[0207] Two insertion holes 455 are formed in the back region 451 at positions offset from the side frames 435. The insertion holes 455 are arranged at a predetermined distance away from the axial direction of the swing axis SX, wherein the predetermined distance is a distance at which the lower frame 436 is stably supported when the lower frame 436 is supported by a pin that stands in the vertical direction (gravity direction). The insertion holes 455 have, for example, a circular outline.

[0208] Two openings 456 are formed at positions away from the side frames 435 in the back region 451 at positions closer to the center in the left-right direction than the two insertion holes 455. The openings 456 are arranged at a predetermined distance away from the axial direction of the swing axis SX, wherein the predetermined distance is a distance at which the connecting shaft 445 is stably supported when the connecting shaft 445 is supported by a clamp erected in the vertical direction (gravity direction). The openings 456 have, for example, a circular outline.

[0209] like Fig.42As shown, a first bearing surface 457 is formed in the back region 451, and the first bearing surface 457 is developed in the first plane Pf, and supports the seat back frame 425 from the rear when assembling. An insertion hole 455 and an opening 456 are opened in the first bearing surface 457. Here, the opening 456 can also be partially enlarged in the reinforcement area 452. A square body 458 is formed on the connecting shaft 445, and the square body 458 is arranged in front of the opening 456 and is held by a clamp as described later. The square body 458 is arranged in a cylindrical space surrounded by a virtual cylindrical surface, which is orthogonal to the first plane Pf and inscribed in the opening 456. The square body 458 can be formed into a square cross-section by, for example, crushing a round tube into a flat state.

[0210] like Fig.44 As shown, the front wall 435b of the side frame 435 has a first height Hf in the axial direction of the swing axis SX from the plate-like portion 435a. The front wall 435b is configured to be offset from the imaginary plane Se in the axial direction of the swing axis SX, and the imaginary plane Se includes the edge of the lower frame 436 and is orthogonal to the swing axis SX. The rear wall 435c of the side frame 435 has: a low wall portion 461a, which is adjacent to the front wall 435b with a space 459 around the swing axis SX and along the periphery of the plate-like portion 435a, and has a first height Hf in the axial direction of the swing axis SX from the plate-like portion 435a; and a high wall portion 461b, which is continuous from the low wall portion 461a, and has a second height Hs greater than the first height Hf in the axial direction of the swing axis SX from the plate-like portion 435a. The curved area 438 of the front wall 435b and the curved area 439 of the rear wall 435c are separated by a space 459. As shown Fig.41 As shown, the high wall portion 461b is arranged above the virtual plane Le, wherein the virtual plane Le is orthogonal to the first plane Pf and contacts the front edge of the reinforcement area 452 from above.

[0211] like Fig.44 As shown, an overlapping piece 462 is formed on the front wall 435b of the side frame 435, and the overlapping piece 462 expands inward from the inner edge of the first height Hf and overlaps with the reinforcement area 452 of the lower frame 436 from the front. A welding mark 463 is formed at a position where the edge of the overlapping piece 462 overlaps with the reinforcement area 452. Here, the welding mark 463 is composed of a welding ridge formed along the edge of the overlapping piece 462. At the welding mark 463, the left and right side frames 435 are joined to the reinforcement area 452 of the lower frame 436. In addition, spot welding or laser welding can be used for welding. Fig.41 As shown, the overlapping piece 462 is arranged below the imaginary plane Le, which is orthogonal to the first plane Pf and contacts the front edge of the reinforcement area 452 from above.

[0212] like Fig.42 As shown in FIG. 1 , each side frame 435 is formed with a second support surface 464, which is developed in a second plane Ps set according to a positional relationship determined relative to the first plane Pf, and supports the seat back frame 425 from the rear when it is assembled. Here, the second plane Ps is set parallel to the first plane Pf. An insertion hole 465 is formed on the rear wall 435c of the side frame 435 at a position offset from the lower frame 436 and opened into the second support surface 464. The insertion hole 465 has, for example, a circular contour.

[0213] like Fig.39 As shown, an auxiliary insertion hole 466 is formed on the rear wall 435c of each side frame 435 at a position above the insertion hole 465 and offset from the upper frame 437. The auxiliary insertion hole 466 is arranged away from the insertion hole 465 in the vertical direction at a predetermined distance, similar to the insertion hole 465, wherein the predetermined distance refers to a distance at which the side frame 435 is stably supported by cooperating with the insertion hole 465 when the side frame 435 is supported by a pin erected in the vertical direction (gravity direction). The auxiliary insertion hole 466 has, for example, a circular contour. The auxiliary insertion hole 466 is developed in an auxiliary plane set according to a positional relationship determined relative to the first plane Pf, and opens on an auxiliary bearing surface that is supported from the rear when the seat back frame 425 is assembled.

[0214] like Fig.45 As shown, the upper frame 437 has: a front wall 469, which is formed by bending a plate and is divided by an upper ridgeline 467 and a lower ridgeline 468 extending in the horizontal direction; an upper wall 471, which is continuous from the upper ridgeline 467 and extends backward; an upper vertical wall 472, which is bent upward from the rear end of the upper wall 471; a lower wall 473, which is continuous from the lower ridgeline 468 and extends backward; and a lower vertical wall 474, which is bent downward from the rear end of the lower wall 473. The upper vertical wall 472 is connected to a first flange 475, which is continuously formed from the upper end of the upper vertical wall 472 and bent forward. The first flange 475 is continuous along the upper edge of the upper vertical wall 472 and covers the entire area in the horizontal direction. The lower vertical wall 474 is connected to a second flange 476, which is continuously formed from the lower end of the lower vertical wall 474 and bent forward. The second flange 476 is continuous along the lower edge of the lower standing wall 474 over the entire area in the horizontal direction.

[0215] The front wall 469 has a connecting piece 469a, which is bent forward at two locations in the horizontal direction, and forms a recessed portion along a valley fold line 477 in the vertical direction, and extends outward. The connecting piece 469a is further bent backward in the horizontal direction outside the recessed portion, and forms a ridge line along a mountain fold line 478 in the vertical direction. As the front wall 469 is deformed, the upper vertical wall 472 and the lower vertical wall 474 are deformed in the same manner. The upper frame 437 is formed of, for example, a single metal plate.

[0216] A welding mark 479 is formed on the front wall 469 at a position outside the mountain fold line 478 in the horizontal direction. Here, the welding mark 479 is composed of welding ridges formed along the edges of the left and right side frames 435. Corresponding to the upper and lower sides of the welding mark 479, welding marks 481 and 482 are formed on the upper vertical wall 472 and the lower vertical wall 474. Here, the welding marks 481 and 482 are composed of welding ridges formed along the edges of the left and right side frames 435. At the welding marks 479, 481, and 482, the upper frame 437 is fixed to the left and right side frames 435. In addition, spot welding and laser welding can be used for welding.

[0217] like Fig.46 As shown, the inner edge of the front wall 435b has a protrusion piece 483, which is spread inward from an imaginary contour line 483a corresponding to the edge of the upper frame 437 and overlaps with the front wall 469 of the upper frame 437 from the rear. A welding mark 479 is formed between the front wall 469 of the upper frame 437 and the protrusion piece 483. The inner edge of the rear wall 435c has: an upper overlapping area 484, which overlaps with the upper vertical wall 472 of the upper frame 437 from the rear; and a lower overlapping area 485, which is located below the upper overlapping area 484, is spaced apart from the upper overlapping area 484, and overlaps with the lower vertical wall 474 of the upper frame 437 from the rear. A welding mark 481 is formed between the upper vertical wall 472 of the upper frame 437 and the upper overlapping area 484. Likewise, a welding mark 482 is formed between the lower standing wall 474 of the upper frame 437 and the lower overlapping region 485 .

[0218] like Fig.47As shown, the upper frame 437 has: a first through hole 487 formed on the upper wall 471 and supporting the headrest support guide 486; and a second through hole 488 formed on the lower wall 473 and supporting the headrest support guide 486. The headrest support guide 486 supports the headrest support 421 in a manner that it can be freely displaced in the axial direction. A positioning flange 489 is formed on the headrest support guide 486, and the positioning flange 489 is extended in a direction orthogonal to the axis. When the headrest support guide 486 is inserted into the first through hole 487 and the second through hole 488 from above, the positioning flange 489 contacts the upper wall 471 from above to position the headrest support guide 486 in the axial direction. The headrest support guide 486 can be molded from a resin material, for example.

[0219] A support hole flange 491 bent downward is formed at the periphery of the first through hole 487 and the second through hole 488. The headrest pillar guide 486 is pressed into the support hole flange 491. The support hole flange 491 fixes the headrest pillar guide 486 to the upper frame 437. The support hole flange 491 can prevent the headrest pillar guide 486 from being separated from the upper frame 437.

[0220] like Fig.48 As shown, a support piece 492 is formed on the first flange 475 at the rear of the first through hole 487 and is bent downward from the front edge of the first flange 475. The support piece 492 supports the headrest pillar guide 486 from the rear. The load acting on the headrest pillar guide 486 from the front is supported by the upper wall 472 of the upper frame 437. In addition, the support piece 492 may be bent upward from the front edge of the first flange 475.

[0221] like Fig.45 As shown in FIG. 1 , a rib (reinforcement shape) 493 is formed on the recessed portion of the front wall 469, and the rib (reinforcement shape) 493 extends while crossing the valley fold line 477, and reinforces the rigidity of the front wall 469 in the bending direction. The rib 493 extends horizontally in the left-right direction. Similarly, a rib (reinforcement shape) 494 is formed on the front wall 469, and the rib (reinforcement shape) 494 extends while crossing the headrest pillar 421 when viewed from the front, and reinforces the rigidity of the front wall 469 in the in-plane direction. The rib 494 is inclined so as to shift upward as it moves from the lowermost end near the center toward the outside.

[0222] Two insertion holes 495 are formed in the front wall 469 in the area sandwiched by the two recessed portions. The insertion holes 495 are arranged at a predetermined distance away from the axial direction of the swing axis SX, wherein the predetermined distance refers to a distance at which the upper frame 437 is stably supported when the upper frame 437 is supported by a pin that stands in the vertical direction (gravity direction). The insertion holes 495 have, for example, a circular contour. Fig.47As shown, the insertion hole 495 is developed in the third plane Pt set according to the positional relationship determined relative to the first plane Pf (or the auxiliary plane), and opens on the third load-bearing surface 496 supported from the rear when the seat back frame 425 is assembled.

[0223] Next, a method for manufacturing the seat back frame 425 is described. When assembling the seat back frame 425, a lower frame 436, left and right side frames 435, and an upper frame 437 are prepared. Fig.49 As shown, the lower frame 436 is set on the first plane Pf. When setting, the insertion pin 501 is inserted into the insertion hole 455. The insertion pin 501 is formed, for example, in a cylindrical shape having an axis that stands in the vertical direction (gravity direction). The insertion pin 501 has a step portion 501a that defines the first plane Pf that is orthogonal to the axis. The first bearing surface 457 of the lower frame 436 is supported on the step portion 501a of the insertion pin 501. By inserting the insertion pin 501 into the insertion hole 455, the lower frame 436 is positioned on the first plane Pf.

[0224] Then, if Fig.50 As shown, the left and right side frames 435 are arranged on the lower frame 436. When arranged, the insertion pin 502 is inserted into the insertion hole 465 of the side frame 435. The insertion pin 502 is formed, for example, in the shape of a cylinder having an axis rising in the vertical direction (direction of gravity), and has a step portion 502a that defines the second plane Ps perpendicular to the axis. The second bearing surface 464 of the side frame 435 is supported on the step portion 502a. At this time, the auxiliary insertion pin (not shown) is further inserted into the auxiliary insertion hole 466 of the side frame 435. The auxiliary insertion pin is formed, for example, in the shape of a cylinder having an axis rising in the vertical direction (direction of gravity). The auxiliary insertion pin has a step portion that defines the auxiliary plane. The auxiliary bearing surface of the side frame 435 is supported on the step portion of the auxiliary insertion pin. The side frame 435 is supported by the second plane Ps and the auxiliary plane. The second plane Ps and the auxiliary plane are arranged based on the positional relationship determined with respect to the first plane Pf, so that the left and right side frames 435 can be positioned on the lower frame 436 with high accuracy. The side frame 435 can overlap with the lower frame 436 in the axial direction of the insertion pin 502. The rear wall 435c of the side frame 435 overlaps with the back region 451 of the lower frame 436. The front wall 435b of the side frame 435 overlaps with the reinforcement region 452 of the lower frame 436 in the axial direction of the insertion pin 502. The side frame 435 positioned in this way is welded to the lower frame 436. Welding marks 454 and 463 are formed.

[0225] Then, if Fig.51As shown in the figure, the upper frame 437 is arranged on the left and right side frames 435. When this arrangement is performed, the insertion pin 503 is inserted into the insertion hole 495 of the upper frame 435. The insertion pin 503 is formed, for example, in a cylindrical shape having an axis that stands in the vertical direction (gravity direction), and has a step portion 503a that defines a third plane Pt that is orthogonal to the axis. The third bearing surface 496 of the upper frame 437 is carried on the step portion 503a. The third plane Pt is arranged according to the positional relationship determined relative to the first plane Pf and the auxiliary plane, so that the upper frame 437 can be positioned on the left and right side frames 435 with high accuracy. The upper frame 437 can overlap with the side frame 435 in the axial direction of the insertion pin 503. The front wall 469 of the upper frame 437 overlaps with the protrusion piece 483 in the axial direction of the insertion pin 503. The upper vertical wall 472 of the upper frame 437 overlaps with the upper overlapping area 484 of the rear wall 435c in the axial direction of the insertion pin 503. When overlapping, the upper vertical wall 472 can avoid interference with the front wall 435b. Similarly, the lower vertical wall 474 of the upper frame 437 overlaps with the lower overlapping area 485 of the rear wall 435c in the axial direction of the insertion pin 503. When overlapping, the lower vertical wall 474 can avoid interference with the front wall 435b. The upper frame 437 positioned in this way is welded to the left and right side frames 435. Welding marks 479, 481, and 482 are formed.

[0226] like Fig.52 As shown, when the lower frame 436 is supported by the insertion pin 501, the clamp 504 enters the opening 456 of the back area 451. A square groove 504a is engraved on the top of the clamp 504 in a manner coaxial with the swing axis SX. The square body 458 of the connecting shaft 445 can be inserted into the square groove 504a. In this way, the connecting shaft 445 can be positioned on each side frame 435. The two ends of the positioned connecting shaft 445 are respectively welded to the rotating body 443 of the backrest angle adjustment unit 434.

[0227] In the seat back frame 425 according to the present embodiment, the lower frame 436 has a reinforcement region 452 which is continuous from the lower edge of the back region 451, extends forward from the swing axis SX, and is joined to the front wall 435b of the side frame 435 from the rear. The lower frame 436 is joined to each side frame 435 in the reinforcement region 452 which extends forward from the lower edge of the back region 451 from the swing axis SX in addition to the back region 451. The torsional rigidity of the seat back frame 425 can be improved. Compared with the case where the lower frame 436 is joined to the side frame only in the back region 451, the joining strength between the lower frame 436 and the side frame 435 can be reduced. In this way, the work load of joining can be reduced. In addition, when assembling the seat back frame 425, the lower frame 436 can be assembled to the side frame 435 from the rear. The side frame 435 can be assembled to the lower frame 436 from one direction. The workability of assembly will not be impaired.

[0228] The side frame 435 has a space 459 formed between the front wall 435b and the rear wall 435c along the periphery of the plate-shaped portion 435a around the backrest angle adjustment unit 434. The front wall 435b formed by bending along the periphery of the plate-shaped portion 435a around the backrest angle adjustment unit 434 and the rear wall 435c formed by bending along the periphery of the plate-shaped portion 435a around the backrest angle adjustment unit 434 are separated by the space 459. When the side frame 435 is stretched, the shape accuracy of the front wall 435b and the rear wall 435c can be improved compared to the case where the front wall 435b and the rear wall 435c are continuous around the backrest angle adjustment unit 434. Therefore, the assembly of the side frame 435 relative to the lower frame 436 is stable.

[0229] In the present embodiment, an opening 456 is formed in the back region 451 of the lower frame 436, and the opening 456 is used to allow the clamp 504 to pass through when assembling the seat back frame 425. On the other hand, a square body 458 is formed on the connecting shaft 445, and the square body 458 is arranged in front of the opening 456 and is held by the clamp 504. When assembling the seat back frame 425, the clamp 504 can be inserted into the opening 456 from the rear. The square body 458 of the connecting shaft 445 can be held by the clamp 504. In this way, the connecting shaft 445 can be positioned at the left and right rotating bodies 443. The connecting shaft 445 can be engaged with each rotating body 443 with good working efficiency.

[0230] A first support surface 457 is formed in the back region 451 of the lower frame 436, which is developed in the first plane Pf and supported from the rear. A second support surface 464 is formed on the rear wall 435c of the side frame 435, and the second support surface 464 is developed in the second plane Ps set according to the positional relationship determined with respect to the first plane Pf, and when supported from the rear, the side frame 435 is positioned on the lower frame 436. When the seat back frame 425 is assembled, the lower frame 436 can be physically supported by the first support surface 457. When the side frame 435 is physically supported by the second support surface 464, the left and right side frames 435 can be positioned on the lower frame 436 according to the positional relationship between the first plane Pf and the second plane Ps. The side frame 435 can be easily positioned on the lower frame 436.

[0231] In addition, the upper frame 437 is formed with a third support surface 496, which is developed in a third plane Pt set according to a positional relationship determined relative to the second plane Ps, and when supported from the rear, the upper frame 437 is positioned on the side frame 435. When the upper frame 437 is physically supported by the third support surface 496, the upper frame 437 can be positioned on the side frame 435 according to the positional relationship between the second plane Ps and the third plane Pt. The upper frame 437 can be easily positioned on the side frame 435.

[0232] In the side frame 435 involved in this embodiment, a protrusion piece 483 is formed at the inner edge of the front wall 435b, and the protrusion piece 483 is expanded inward from the imaginary outline 483a corresponding to the shape of the upper frame 437, and overlaps with the front wall 469 of the upper frame 437 from the rear. The upper frame 437 can be assembled from the front to the left and right side frames 435 arranged at a distance during assembly. At this time, the front wall 435b of the side frame 435 does not need to interfere with the upper vertical wall 472 and the lower vertical wall 474 of the upper frame 437 located at the rear of the front wall 469. In this way, the working efficiency can be improved when assembling the upper frame 437.

[0233] The front wall 469 of the upper frame 437 has a connecting piece 469a, which is bent forward at two locations in the horizontal direction, and forms a recessed portion along the valley fold line 477 in the vertical direction and extends toward the protruding piece 483. A convex ridge 493 is formed in the recessed portion of the front wall 469, and the convex ridge 493 extends while crossing the valley fold line 477, thereby reinforcing the rigidity in the bending direction. The rigidity can be increased for the bending along the valley fold line 477 on the front wall 469. Therefore, when the upper frame 437 is assembled, the deformation of the upper frame 437 can be suppressed. The assembly work efficiency can be improved.

[0234] A ridge 494 is formed on the front wall 469 of the upper frame 437. The ridge 494 extends while crossing the headrest support 421 when viewed from the front, thereby increasing rigidity in the in-plane direction. The rigidity of the front wall 469 can be increased by corresponding to the first through hole 487 of the upper wall 471 and the second through hole 488 of the lower wall 473 on the upper frame 437. Therefore, when the upper frame 437 is assembled, deformation of the upper frame 437 can be suppressed. The assembly work efficiency can be improved.

[0235] In the upper frame 437 according to the present embodiment, a bearing piece 492 is formed on the first flange 475 behind the first through hole 487. The bearing piece 492 is continuously bent downward from the front edge of the first flange 475. The bearing piece 492 can correspond to the first through hole 487 of the upper wall 471 and the second through hole 488 of the lower wall 473, thereby improving the rigidity of the front wall 469. Therefore, when the upper frame 437 is assembled, deformation of the upper frame 437 can be suppressed. The assembly work efficiency can be improved.

[0236] like Fig.53 As shown in (A) of FIG. 4 , a through opening 505 may be formed between the left and right ribs 494 on the front wall 469 of the frame 437. The through opening 505 can contribute to the weight reduction of the upper frame 437. The ribs 494 can suppress the reduction in rigidity caused by the formation of the through opening 505. In addition, as Fig.53 As shown in (B) in FIG. 4 , in addition to the through opening 505 of the front wall 469, a through opening 506 may be formed on the lower wall 474 of the upper frame 437. The through opening 506 can help to further reduce the weight of the upper frame 437. Fig.53 As shown in (C) in FIG. 1 , the lower vertical wall 474 itself may be shortened in the vertical direction. In this case, the ridge 493 may extend toward the mountain fold line 478 .

[0237] like Fig.54 As shown, the connecting shaft 445 itself can be formed by a square tube. In this case, the square tube forms a square body 458 in front of the opening 456.

[0238] like Fig.55 As shown, a support tube 507 is fixed to the upper wall 471 and the lower wall 473 of the upper frame 436. The support tube 507 is inserted into the first through hole 487 and the second through hole 488 to support the headrest support guide portion 486. The support tube 507 is formed of, for example, a metal material. Here, small pieces 508 and 509 are bent upward and downward from the periphery of the first through hole 487 and the second through hole 488, respectively. Fig.56As shown, each small piece 508, 509 overlaps the outer surface of the support tube 507. The small pieces 508, 509 are welded to the support tube 507. As with the welding of the upper frame 437 and the side frame 435, the welding can be performed from the front, thereby improving the work efficiency of assembling the seat frame 423. The headrest support guide 486 is pressed into the support tube 507.

[0239] The support tube 507 is supported from the rear by the carrier sheet 492. The rigidity of the front wall 469 is increased by the support tube 507 and the carrier sheet 492. Therefore, when the upper frame 437 is assembled, deformation of the upper frame 437 can be suppressed, thereby improving the assembly work efficiency.

Claims

1. A vehicle seat (411) having a seat back frame (425), wherein the seat back frame (425) has left and right side frames (435), a lower frame (436) and an upper frame (437), wherein: The left and right side frames (435) have a plate-like portion (435a), a front wall (435b) and a rear wall (435c); the plate-like portion (435a) is unfolded around the rotation axis along a vertical plane orthogonal to the rotation axis (SX) and extends upward along the vertical plane; the front wall (435b) is continuously and inwardly bent from the front edge of the plate-like portion (435a) to form a curved area (438) extending from the rotation axis in the vertical direction; the rear wall (435c) is continuously and inwardly bent from the rear edge of the plate-like portion (435a) to form a curved area (439) extending from the rotation axis in the vertical direction. The lower frame (436) has a back region (451), which is arranged behind the rotation axis (SX), is engaged with the rear wall (435c) from the rear, and connects the left and right side frames (435) to each other; The upper frame (437) connects the left and right side frames (435) to each other above the lower frame (436). The vehicle seat is characterized in that: The lower frame (436) has a reinforcement area (452) which is continuous from the lower edge of the back area (451), extends forward from the rotation axis (SX), and is connected to the front wall (435b) from the rear.

2. The vehicle seat according to claim 1, characterized in that: The side frame (435) has a space (459) formed between the front wall (435b) and the rear wall (435c) along the periphery of the plate-shaped portion (435a) around the rotation axis.

3. The vehicle seat according to claim 1 or 2, characterized in that: It also has a backrest angle adjustment mechanism (434) and a connecting component (445), wherein: The backrest angle adjustment mechanisms (434) are respectively mounted on the side frames (435) to connect the seat back frame (425) to the seat cushion frame (424) in a manner that the seat back frame (425) can rotate freely around the rotation axis (SX); The connecting component (445) connects the left and right backrest angle adjustment mechanisms (434). An opening (456) is formed in the back region (451) of the lower frame (436) to allow a clamp (504) to pass through when assembling the seat back frame (425). A square body (458) is formed on the connecting member (445), and the square body (458) is arranged in front of the opening (456) and is held by the clamp (504).

4. The vehicle seat according to claim 1 or 2, characterized in that: A first supporting surface (457) is formed on the back region (451) of the lower frame (436), and the first supporting surface (457) is extended in a first plane (Pf) and supported from the rear. A second bearing surface (464) is formed on the rear wall (435c) of the side frame (435), and the second bearing surface (464) is unfolded within a second plane (Ps) set according to a positional relationship determined relative to the first plane (Pf), and positions the side frame (435) on the lower frame (436) when supported from the rear.

5. The vehicle seat according to claim 1 or 2, characterized in that: The upper frame (437) has a front wall (469), an upper wall (471), an upper vertical wall (472), a lower wall (473) and a lower vertical wall (474), wherein: The front wall (469) is formed by bending a plate and is divided by an upper ridgeline (467) and a lower ridgeline (468) extending in the horizontal direction; The upper wall (471) is continuous from the upper ridgeline (467) and extends rearward; The upper vertical wall (472) is bent upward from the rear end of the upper wall (471) and is connected to the rear wall (435c) from the front; The lower wall (473) is continuous from the lower ridgeline (468) and extends rearward; The lower vertical wall (474) is bent downward from the rear end of the lower wall (473) and is connected to the rear wall (435c) from the front. The inner edge of the front wall (435b) has a protrusion (483), which extends inward from an imaginary contour line (483a) corresponding to the shape of the upper frame (437) and overlaps with the front wall (469) from the rear.

6. The vehicle seat according to claim 5, characterized in that: The front wall (469) has a connecting piece (469a), which is bent forward at two locations in the horizontal direction, forms a recessed portion along a valley fold line (477) in the vertical direction, and extends toward the protruding piece (483). A reinforcement shape (493) is formed in the recessed portion, and the reinforcement shape (493) extends while intersecting the valley fold line (477) to enhance rigidity in the bending direction.

7. The vehicle seat according to claim 5, characterized in that: Coaxial through holes (487, 488) for holding the headrest pillar (421) are formed on the upper wall (471) and the lower wall (473). A reinforcement shape (494) is formed on the front wall (469), and the reinforcement shape (494) extends while crossing the headrest pillar (421) when viewed from the front, thereby reinforcing the rigidity in the in-plane direction.

8. The vehicle seat according to claim 5, characterized in that: Coaxial through holes (487, 488) for holding the headrest pillar (421) are formed on the upper wall (471) and the lower wall (473). A flange (475) is formed on the upper vertical wall (472), and the flange (475) is continuously formed from the upper end of the upper vertical wall (472) and is bent forward. A carrier sheet (492) is formed on the flange (475) behind the through holes (487, 488). The carrier sheet (492) is formed continuously from the front edge of the flange (475) and is bent upward or downward.

9. The vehicle seat according to claim 8, characterized in that: A support tube (507) is fixed on the upper wall (471) and the lower wall (473), and the support tube (507) is inserted into the through hole (488, 489) to support a headrest support guide portion (486) for guiding the headrest support (421). The supporting sheet (492) supports the supporting cylinder (507) from the rear.

10. The vehicle seat according to claim 5, characterized in that: A first supporting surface (457) is formed on the back region (451) of the lower frame (436), and the first supporting surface (457) is extended in a first plane (Pf) and supported from the rear. A second bearing surface (464) is formed on the rear wall (435c) of the side frame (435), the second bearing surface (464) being developed in a second plane (Ps) set according to a positional relationship determined relative to the first plane (Pf), and positioning the side frame (435) on the lower frame (436) when supported from the rear, A third bearing surface (496) is formed on the upper frame (437), and the third bearing surface (496) is unfolded within a third plane (Pt) set according to a positional relationship determined relative to the second plane (Ps), and when supported from the rear, the upper frame (437) is positioned on the side frame (435).

Images