JP2019182426A - Vehicular seat - Google Patents

Abstract

To form a housing section for other members inside a seat back frame without impairing rigidity of the seat back frame in a vehicular seat.SOLUTION: A vehicular seat S includes a seat back frame F2 including: first and second side frames 8 and 9 in which each lower end is connected to a seat cushion frame F1; an upper frame 10 stretched between upper sections of the first and second side frames; and a lower frame 11 stretched between lower sections of the first and second side frames. A housing section 37 in which arbitrary members are arranged is formed at the lower inside of the first side frame. A first end 11A connected to the first side frame of the lower frame is arranged so as to avoid the housing section to be offset to a second end 11B connected to the second side frame in a longitudinal direction or a vertical direction.SELECTED DRAWING: Figure 9

Description

  The present invention relates to a vehicle seat mounted on a vehicle or the like.

  Conventionally, a vehicle seat having a seat cushion frame that supports a seat cushion, a seat back frame that supports a seat back, and a reclining mechanism that couples the seat back frame to the seat cushion frame so that the angle of the seat cushion frame can be adjusted is known ( For example, Patent Document 1). In the vehicle seat described in Patent Literature 1, the seat back frame is a pair of left and right back side frames, a back upper frame spanned between upper ends of the pair of back side frames, and a lower portion of the pair of back side frames. And a back lower frame spanned between the two.

JP 2014-129007 A

  By providing the back lower frame, the rigidity of the seat back frame can be increased. However, since the back lower frame passes through the space formed inside the back side frame, it is difficult to arrange other members and devices inside the back side frame. As an apparatus arrange | positioned inside a back side frame, the electric motor, the deceleration mechanism, etc. which drive a reclining mechanism are mentioned, for example.

  In view of the above-described background, an object of the present invention is to form an accommodation portion for another member inside a seat back frame in a vehicle seat without impairing the rigidity of the seat back frame.

  In order to solve the above problems, a vehicle seat of the present invention includes first and second side frames (8, 9) each having a lower end portion coupled to a seat cushion frame (F1), and the first and second side frames. A seat back frame (F2) including an upper frame (10) spanned between upper portions of two side frames and a lower frame (11) spanned between lower portions of the first and second side frames; The first end (11A) coupled to the first side frame of the lower frame is offset from front to back or up and down with respect to the second end (11B) coupled to the second side frame. By being arranged, an accommodation part (37) is formed on the inner side of the lower part of the first side frame and on the side opposite to the offset direction of the first end part.

  According to this structure, an accommodating part can be formed in the side opposite to the offset direction by offsetting a 1st end part with respect to a 2nd end part. In other words, the first and second side frames can be joined by the lower frame while forming the accommodating portion inside the first side frame.

  In the above invention, the first side frame has a protruding portion (21D) that protrudes rearward from a corresponding portion at the top and bottom of the second side frame, and the first end portion is the second end frame. It is good to be arranged offset to the protruding part side with respect to the end part.

  According to this configuration, since the first end of the lower frame is offset in a direction away from the back of the occupant seated on the vehicle seat, it is difficult to affect the occupant seated on the vehicle seat (foreign object feeling). Become. Further, by providing the protruding portion, it is possible to increase the amount of offset to the rear of the first end portion. Moreover, since the distance between the first end and the rear edge of the first side frame is ensured by the protruding portion, the rigidity of the coupling portion between the first end and the first side frame is increased.

  In the above invention, at least a part of the first end portion may be coupled to the protruding portion.

  According to this configuration, the amount of offset to the rear of the first end can be further increased.

  Further, in the above invention, the lower frame is formed such that a central portion (11C) in the left-right direction is formed in a bilaterally symmetric shape, and the shapes of the first end portion and the second end portion are different from each other. The end may be offset with respect to the second end.

  According to this structure, since the center part of the lower frame corresponding to a passenger | crew's back part is formed in the left-right symmetric form, it becomes difficult to influence a passenger | crew.

  In the above invention, the central portion of the lower frame may be disposed below and behind the first end and the second end.

  According to this structure, since the center part of the lower frame corresponding to a passenger | crew's back part is arrange | positioned in the position spaced apart from the passenger | crew's back part, it becomes difficult to influence a passenger | crew.

  In the above invention, a first reclining mechanism (41) is provided between the first side frame and the seat cushion frame, and an electric motor (not shown) that drives the first reclining mechanism is provided in the housing portion. 47A) may be arranged.

  According to this configuration, the electric motor is efficiently stored in the seat back. Further, since the electric motor is disposed inside the first side frame, it is possible to prevent a load from being applied from the outside.

  In the above invention, the electric motor includes a housing (47D) and a connector (47C) to which the first wire harness (48) is connected, and the connector is the first of the outer surface of the housing. It is good to be provided in the part facing the end side.

  According to this configuration, the connector is disposed between the housing and the lower frame, and is prevented from receiving a load from the outside.

  In the above invention, a harness support portion (49) for supporting the first wire harness may be provided on the first end portion side of the lower frame.

  According to this configuration, since the first wire harness connected to the electric motor is supported on the first end side of the lower frame close to the connector, the swing of the first wire harness is suppressed.

  Further, in the above invention, an auxiliary frame (50) protruding downward is provided at a central portion in the left-right direction of the lower frame, and a lower end of the auxiliary frame is from a rotation center of the first reclining mechanism. Is also preferably arranged below.

  According to this configuration, the lower end portion of the seat back is retained by the auxiliary frame. In an automobile production line, a lower end portion of a seat back may be supported by a hanger device in order to move a vehicle seat. In this case, since the auxiliary frame is present at the lower end of the seat back, the load of the vehicle seat is applied to the hanger device via the auxiliary frame, and the deformation of the seat back is suppressed.

  In the above invention, a second reclining mechanism (42, 43) is provided between the second side frame and the seat cushion frame, and the first and second reclining mechanisms are coupled to the seat cushion frame. The first member is provided between the first member, the second member coupled to the first and second side frames, and the first member and the second member. Drive shafts (44, 45) for switching between coupling and separation with the second member, each of the drive shafts being arranged coaxially with each other and coupled to rotate integrally with each other, and the auxiliary The lower end of the frame is disposed below the drive shaft.

  According to this configuration, since the auxiliary frame extends below the drive shaft, a load applied to the seat back from below is applied to the auxiliary frame and is prevented from being applied to the drive shaft. For example, when the lower end portion of the seat back is supported by a hanger device in an automobile production line, a load is prevented from being applied to the drive shaft.

  In the above invention, the auxiliary frame may be disposed behind the drive shaft.

  According to this configuration, since the auxiliary frame is disposed at a position away from the occupant, it is difficult to affect the occupant.

  In the above invention, in order to correspond to the upper back portion of the occupant, the movable frame coupled to the first and second side frames so as to be tiltable about a rotation shaft disposed above the lower frame ( F3), a second wire harness extending toward the movable frame, and a regulating member (89, 89B) provided so as to protrude upward from the lower frame and restricting the swing of the second wire harness. Furthermore, it is good to have.

  According to this configuration, the swing of the second wire harness is suppressed by the restricting member, and for example, approach to the coupling portion between the first and second side frames and the movable frame is prevented.

  According to the above configuration, in the vehicle seat, the housing portion for another member can be formed inside the seat back frame without impairing the rigidity of the seat back frame.

The perspective view of the frame of the vehicle seat concerning an embodiment Perspective view of seat back frame as seen from diagonally left front Perspective view of the upper part of the seat back frame showing the movable frame omitted Left side view of the upper part of the seat back frame with the movable frame omitted Left side view of the lower part of the seat back frame showing the positional relationship between the back lower frame and the drive device through the left back side frame A perspective view of the lower part of the seat back frame as seen from the left rear Perspective view of the lower part of the seat back frame as viewed from the right rear Front view of the lower part of the seat back frame Perspective view of the lower part of the seat back frame as viewed from the right front The disassembled perspective view which shows the coupling structure of the drive shaft of the 4th reclining mechanism, the extension shaft, and the operation lever

  Hereinafter, an embodiment in which the present invention is applied to a rear seat (including second and third rows) of an automobile will be described with reference to the drawings. In the following description, the left and right are determined based on the occupant seated on the seat S. About the same structure provided in right and left pair, a common number is attached | subjected and description is abbreviate | omitted.

  As shown in FIG. 1, the frame of the vehicle seat S includes a seat cushion frame F1 that constitutes a seat cushion, a seat back frame F2 that constitutes a seat back, and a movable frame (a center folded frame) F3. . A seat cushion is configured by covering the seat cushion frame F1 with a pad and a skin material, and a seat back is configured by covering the lower portion of the seat back frame F2 and the movable frame F3 with the pad and the skin material. The pad is made of a cushioning material having elasticity such as polyurethane foam, and the skin material is made of synthetic leather or cloth. Further, the rear portion of the seat back is covered with a cover formed of resin or the like.

  The seat cushion frame F1 is hung between a pair of left and right cushion side frames 2 extending in the front-rear direction, a plate-like pan frame 3 spanned between the front portions of the cushion side frames 2, and the rear portions of the cushion side frames 2. It has a rear frame 4 passed to it, and is formed in a frame shape. The seat cushion frame F <b> 1 is coupled to the vehicle floor via the slide device 5. The slide device 5 includes a rail and a slider supported so as to be movable on the rail, and the rail may extend in the front-rear direction and the left-right direction.

  The seat back frame F2 includes a pair of left and right back side frames 8, 9 extending substantially vertically, a back upper frame 10 spanned between upper ends of the left and right back side frames 8, 9, and the back side frames 8, 9 And a back lower frame 11 spanned between the lower portions of the frame. Note that the lower end portions of the left and right back side frames 8 and 9 extend below the back lower frame 11.

  As shown in FIGS. 1 to 3, the right back side frame 9 includes an upper right back side frame 13 that extends substantially vertically and a lower right back side frame 14 that is coupled to the lower portion of the upper right back side frame 13. The upper right backside frame 13 includes an inner member 13A and an outer member 13B that are sheet metal members. The inner member 13A and the outer member 13B each have a groove-shaped cross section, and the inner member 13A is disposed on the left side (inward of the seat back in the left-right direction) with respect to the outer member 13B. The inner member 13A is arranged so that the groove-shaped opening faces rightward, and the outer member 13B is fitted in the inner member 13A with the groove-shaped opening facing leftward. The inner member 13A and the outer member 13B are coupled to each other by welding or the like. Thereby, the upper right backside frame 13 is formed in a closed cross-sectional structure in which the cross section is substantially rectangular in each part in the longitudinal direction.

  As shown in FIG. 2, the lower right back side frame 14 is a sheet metal member, is joined to the lower outer side of the upper right back side frame 13 by welding or the like, and protrudes below the lower end of the upper right back side frame 13. The lower right backside frame 14 is formed with ribs 14A that protrude leftward (inward) at the front edge, the rear edge, and the lower edge excluding the upper edge of the main surface. The rib 14A is formed by bending up the edge of the lower right backside frame 14. The lower end portion of the upper right back side frame 13 is disposed between the ribs 14A of the lower right back side frame 14, and the ribs 14A and the front and rear surfaces of the upper right back side frame 13 are in contact with each other.

  A belt guide racket 17 for supporting the belt guide 16 of the seat belt is coupled to the upper end portion of the right back side frame 9. The belt guide racket 17 is formed by combining a plurality of sheet metal members, and the belt guide racket 17 coupled to the upper end portion of the right back side frame 9 by welding or the like protrudes upward from the upper end portion of the right back side frame 9. The belt guide 16 is coupled to the upper end of the belt guide 16.

  The belt guide 16 is a member for guiding the seat belt. The belt guide 16 is formed of a sheet metal member and has a guide hole that is a through hole through which the seat belt can pass. The belt guide 16 is placed on the upper end portion of the belt guide racket 17 so that the guide hole faces front and rear, and is coupled to the belt guide racket 17 by coupling means such as bolt fastening. Although not shown, a belt retractor is provided below the seat cushion frame F1 so as to retract the seat belt so that the seat belt can be pulled out. The seat belt extends rearward below the seat cushion frame F1 and extends upward along the rear surface of the right back side frame 9. And is pulled forward through the belt guide 16.

  As shown in FIGS. 1 to 7, the left back side frame 8 includes an upper left back side frame 21 that extends substantially vertically and a lower left back side frame 22 that is coupled to the lower part of the upper left back side frame 21. The upper left back side frame 21 and the lower left back side frame 22 are formed of sheet metal members. The upper left backside frame 21 has a curved portion 23 that smoothly curves rearward and rightward (back upper frame 10 side) at its upper end portion, and has a distal end portion 23A (upper end portion) extending rightward. The side part 21A that forms the main part of the upper left backside frame 21 is continuously changed from a form in which the surface faces left and right in most parts except the curved part 23, and a form in which the surface faces in the left and right direction in the curved part 23. It has changed. Thereby, the front edge of the side part 21A in the lower part of the upper left back side frame 21 is continuously changed to the upper edge in the curved part 23, and the rear edge of the side part 21A in the lower part of the upper left back side frame 21 is the curved part. 23 continuously changes to the lower edge.

  Ribs 21 </ b> B and 21 </ b> C projecting inward (rightward) are formed on the front edge and rear edge of the side part 21 </ b> A of the upper left backside frame 21. The ribs 21 </ b> B and 21 </ b> C extend along the longitudinal direction of the upper left backside frame 21, are provided along the upper edge and the lower edge in the curved portion 23, and protrude toward the front. Thereby, the cross section of each part in the longitudinal direction is formed in a groove shape, and the upper left back side frame 21 has an open cross section structure. The ribs 21B and 21C are formed by bending up the edge of the side part 21A.

  As shown in FIGS. 6, 7, and 9, the lower left back side frame 22 is a sheet metal member and is joined to the lower outer side (left side) of the upper left back side frame 21 by welding or the like, and the lower end of the upper left back side frame 21. Protrudes downwards. The lower left back side frame 22 has a main surface facing left and right, and a rib 22A that protrudes inward (rightward) from the front edge, the rear edge, and the lower edge excluding the upper edge. The rib 22A is formed by bending up the edge of the lower left backside frame 22. The lower end portion of the upper left back side frame 21 is disposed between the ribs 22A of the lower left back side frame 22, and the rib 22A of the lower left back side frame 22 and the front and rear surfaces of the ribs 21B and 21C of the upper left back side frame 21 are in contact with each other. It touches.

  As shown in FIG. 3, the back upper frame 10 includes a front member 26 and a rear member 27 that are sheet metal members. The front member 26 and the rear member 27 each have a groove-shaped cross section, and the front member 26 is disposed forward with respect to the rear member 27. The rear member 27 is disposed so that the groove-shaped opening faces forward, and the front member 26 is fitted in the rear member 27 with the groove-shaped opening facing rearward. The front side member 26 and the rear side member 27 are coupled to each other by welding or the like. Thereby, the back upper frame 10 is formed in a closed cross-sectional structure in which the cross section is substantially rectangular in each part in the longitudinal direction.

  Each of the front member 26 and the rear member 27 has a right end portion coupled to an upper end portion of the upper right backside frame 13. Specifically, the right end portion of the rear side member 27 is welded to the rear surface of the upper right back side frame 13, and the right end portion of the front side member 26 is welded to the left side surface of the upper right back side frame 13.

  At the left end portion of the back upper frame 10, the left end portion 26 </ b> A of the front side member 26 protrudes leftward from the left end portion 27 </ b> A of the rear side member 27. As a result, the back upper frame 10 has an open cross-sectional structure at the left end, and has a closed cross-sectional structure at other portions except the left end. The left end portion 27A of the rear side member 27 abuts with the tip end portion 23A of the curved portion 23 of the left side frame and is coupled to each other by welding. The left end portion 26 </ b> A of the front side member 26 protrudes into and fits into a groove shape that opens toward the front of the bending portion 23. The ribs protruding rearward from the upper edge and the lower edge of the front member 26 are disposed between and in contact with the ribs formed on the upper edge and the lower edge of the curved portion 23. The front member 26 cooperates with the curved portion 23 to form a closed cross-sectional structure.

  As shown in FIG. 3, a reinforcing member 30 is provided inside the upper half of the upper left backside frame 21. The reinforcing member 30 is formed of a sheet metal member and has a groove-shaped cross section. The reinforcing member 30 is fitted inside the groove shape of the upper left frame so that the groove shape opening faces the groove shape opening of the upper left frame. That is, the reinforcing member 30 extends in a curved manner at the portion corresponding to the curved portion 23 in the same manner as the curved portion 23. The reinforcing member 30 has an upper end portion 30A that abuts the left end portion 26A of the front side member 26 of the back upper frame 10 disposed in the curved portion 23, and passes through the curved portion 23 from the upper end portion 30A and passes through the upper left back. The side frame 21 extends to an intermediate portion in the vertical direction. The main surface of the reinforcing member 30 is bent so as to face front and rear at the upper end portion, continuously turn left and right as it proceeds downward along the curved portion 23, and turns left and right at the lower end portion. The ribs formed along both side edges of the reinforcing member 30 are in contact with the inner surfaces of both the ribs 21B and 21C of the upper left backside frame 21. The reinforcing member 30 has an upper end portion 30 </ b> A that abuts the left end portion 26 </ b> A of the front side member 26 of the back upper frame 10, and is welded at a plurality of locations where the reinforcing member 30 contacts the protruding ends of both ribs of the upper left backside frame 21.

  The reinforcing member 30 forms a closed cross-sectional structure in cooperation with the upper half portion including the curved portion 23 of the upper left backside frame 21. The open end of the closed cross-sectional structure formed by the reinforcing member 30 and the upper left back side frame 21 is combined with the open end of the closed cross-sectional structure formed by the back upper frame 10 to form a continuous closed cross-sectional structure. That is, the front side member 26 and the rear side member 27 of the back upper frame 10, the upper half portion of the upper left back side frame 21, and the reinforcing member 30 cooperate to form a closed cross-sectional structure in which the hollow portions are continuous. Thereby, the part ranging from the upper part of seat back frame F2 to the left side part is comprised by the closed cross-section structure where the hollow part continued.

  Since the left end portion 26A of the front side member 26 of the back upper frame 10 is arranged on the left side of the left end portion 27A of the rear side member 27, the connecting portion between the rear side member 27 and the upper left back side frame 21, and the front side member 26 and the connecting part of the reinforcing member 30 are arranged offset from each other in the left-right direction. As a result, the back upper frame 10 and the upper left back side frame 21 form an overlapping portion when viewed from the front-rear direction or the vertical direction. The overlapping portion increases the rigidity of the connecting portion between the upper left backside frame 21 and the back upper frame 10.

  As shown in FIGS. 2 and 4, the curved portion 23 of the back upper frame 10 and the upper left back side frame 21 constitutes an upper portion of the seat back frame F <b> 2 so that the central portion in the left-right direction is convex backward as a whole. Is curved.

  As shown in FIG. 3 and FIG. 4, a positioning hole 31 penetrating in the left-right direction is formed in the side portion 21 </ b> A of the upper left back side frame 21 and positioned below the bending portion 23. . The positioning hole 31 has a long hole shape extending along the longitudinal direction of the upper left backside frame 21. The positioning hole 31 is used for the purpose of setting the position of the upper left back side frame 21 at a predetermined position by inserting a positioning pin of the manufacturing apparatus when the sheet S is manufactured. The lower end edge 30B of the reinforcing member 30 is disposed at a position overlapping the positioning hole 31 when viewed in the left-right direction. Specifically, the lower end edge 30 </ b> B of the reinforcing member 30 is disposed corresponding to an intermediate portion in the vertical direction of the positioning hole 31. Thereby, seeing from the left-right direction, the upper half part of the positioning hole 31 is covered with the reinforcement member 30, and the lower half part has penetrated right and left. Thereby, the insertion amount of the positioning pin of the manufacturing apparatus can be increased in the lower portion of the positioning hole 31.

  A left pad support bracket 32 is joined to the lower portion of the right side surface of the side portion 21A of the upper left backside frame 21 with respect to the positioning hole 31 by welding or the like. The left pad support bracket 32 has a mounting surface that passes below the reinforcing member 30 and protrudes rightward and faces upward. A gap is formed between the mounting surface of the left pad support bracket 32 and the lower edge of the reinforcing member 30. A right pad support bracket 33 is coupled to the left side surface of the upper right backside frame 13. The right pad support bracket 33 is disposed at a position corresponding to the left pad support bracket 32, has a placement surface that protrudes leftward and faces upward. On the mounting surface of the left pad support bracket 32 and the right pad support bracket 33, the engaging portion of the seat back pad is mounted.

  As shown in FIGS. 6 to 9, the back lower frame 11 has a closed cross-sectional structure and is coupled to the left end portion 11 </ b> A coupled to the lower end portion of the upper left back side frame 21 and the lower end portion of the upper right back side frame 13. Right end portion 11B. The back lower frame 11 according to the present embodiment is formed by bending a metal pipe having a circular cross section.

  The connecting portion between the right end portion 11B of the back lower frame 11 and the upper right back side frame 13 is arranged to be offset rearward from the center in the front-rear direction of the left side surface and right side portion of the upper right back side frame 13. The rear edge of the right end portion 11B of the back lower frame 11 is disposed in front of the rear edge of the left side surface portion and the right side surface portion of the upper right back side frame 13. The right end portion 11B of the back lower frame 11 is disposed below the upper edge of the lower right back side frame 14 in the vertical direction. A right insertion hole 35 through which the right end portion 11 </ b> B of the back lower frame 11 passes is formed in the left side surface portion, the right side surface portion, and the lower right back side frame 14 of the upper right back side frame 13. Each right insertion hole 35 is preferably formed in a size that allows the right end portion 11B of the back lower frame 11 to be fitted. The right end portion 11 </ b> B of the back lower frame 11 is welded to the periphery of the right insertion hole 35 of the upper right back side frame 13 while being inserted into each right insertion hole 35. The end surface of the right end portion 11B of the back lower frame 11 is preferably disposed so as to be substantially flush with the outer surface of the lower right back side frame 14.

  As shown in FIGS. 6 and 7, the side portion 21 </ b> A of the upper left backside frame 21 has a protruding portion 21 </ b> D that protrudes rearward from the corresponding portion at the top and bottom of the upper right backside frame 13. The rear edge (outer edge) of the protrusion 21D is formed in a smooth curved shape, and the rib 21C extends along the rear edge of the protrusion 21D. The left end portion 11A of the back lower frame 11 is arranged to be offset rearward from the center in the front-rear direction of the side portion 21A. The left end portion 11A of the back lower frame 11 may be arranged so that at least a part thereof overlaps the protruding portion 21D. That is, the rear edge of the left end portion 11 </ b> A of the back lower frame 11 may be disposed behind the rear edge of the upper left backside frame 21 excluding the protruding portion 21 </ b> D. Further, as shown in FIG. 5, the connecting portion between the left end portion 11 </ b> A of the back lower frame 11 and the upper left back side frame 21 is behind the connecting portion between the right end portion 11 </ b> B of the back lower frame 11 and the upper right back side frame 13. It is arranged offset.

  As shown in FIG. 6, a left insertion hole 36 through which the left end portion 11 </ b> A of the back lower frame 11 passes is formed in the side portion 21 </ b> A of the upper left back side frame 21. The left insertion hole 36 is preferably formed in a size that allows the left end 11 </ b> A of the back lower frame 11 to be fitted. The left insertion hole 36 preferably overlaps with the protrusion 21D and is formed at a position that does not reach the rear edge of the protrusion 21D. The lower left back side frame 22 has a portion corresponding to the left insertion hole 36, and the left insertion hole 36 is exposed to the left. The left end portion 11A of the back lower frame 11 is welded to the periphery of the left insertion hole 36 on the inner surface of the side portion 21A while being inserted into the left insertion hole 36. The end surface of the left end portion 11 </ b> A of the back lower frame 11 may be disposed so as to be substantially flush with the outer surface of the lower left back side frame 22.

  A central portion 11C in the left-right direction of the back lower frame 11 is disposed behind and below the left end portion 11A and the right end portion 11B. The left end portion 11A and the right end portion 11B of the back lower frame 11 extend from the connecting portion with the upper left back side frame 21 and the upper right back side frame 13 so as to advance backward and downward as proceeding to the center side in the left-right direction. A central portion 11C of 11 extends linearly in parallel with the left-right direction. Since the left end portion 11A of the back lower frame 11 is disposed rearward with respect to the right end portion 11B, the inclination with respect to the front-rear direction is smaller than that of the right end portion 11B. With the above shape, the back lower frame 11 has a left-right asymmetric shape at both ends in the left-right direction, while a shape at the center portion 11C is a left-right symmetrical shape.

  As shown in FIG. 9, the left end portion 11A of the back lower frame 11 is coupled to the upper left back side frame 21 at the protruding portion 21D, and is offset backward with respect to the center in the front-rear direction of the upper left back side frame 21. An accommodating portion 37 for accommodating other components and devices is formed inside the upper left back side frame 21 (on the right side) and in front of the left end portion 11A of the back lower frame 11. Since the upper left back side frame 21 is formed in a groove shape that opens inward, the accommodating portion 37 is formed inside the groove shape of the upper left back side frame 21.

  As shown in FIGS. 6 to 8, the rear portion of the left cushion side frame 2 and the lower end portion of the left backside frame 8 (lower left backside frame 22) are coupled to each other via a first reclining mechanism 41. A rear portion of the right cushion side frame 2 and a lower end portion (lower right back side frame 14) of the right back side frame 9 are coupled to each other via second and third reclining mechanisms 42 and 43. As a result, the seat back frame F2 can be rotated (tilted) with the axis extending in the left-right direction as a rotation axis. Each reclining mechanism 41-43 is an apparatus which maintains the inclination (rotation) angle of each back side frame 8, 9 with respect to each cushion side frame 2 at an arbitrary position, and various known mechanisms can be applied. . Each of the reclining mechanisms 41 to 43 is an electric reclining device that changes the rotation angle in response to the rotational force of the electric motor, and includes a disc-shaped first member (not shown) coupled to the cushion side frame 2. A second member (not shown) which is formed in a disc shape and is arranged to face the first member, and is coupled to the lower right back side frame 14 and the lower left back side frame 22, and the first member and the second member. Each has a drive shaft (not shown) that passes through the central portion of the member and changes the relative angle of the first member and the second member by rotating with respect to the first member. In the reclining mechanisms 41 to 43, the angle of the second member with respect to the first member changes according to the rotation amount of the drive shaft.

  An example of such reclining mechanisms 41 to 43 will be described. The first member has a first cylindrical portion protruding coaxially with the rotation axis. An external gear is formed on the outer peripheral surface of the first cylindrical portion. The second member has a second cylindrical portion that protrudes coaxially with the rotation axis and receives the first cylindrical portion. An internal gear is formed on the inner peripheral surface of the second cylindrical portion. The inner diameter of the second cylindrical portion is formed larger than the outer diameter of the first cylindrical portion, and the number of teeth of the internal gear is formed 1 or 2 more than the number of teeth of the external gear. The first member and the second member are arranged eccentrically with each other when the outer gear and the inner gear mesh with each other. A 2nd member has the 3rd cylindrical part which protruded coaxially inside the 2nd cylindrical part. The third cylindrical portion has an outer diameter that is sufficiently smaller than the inner diameter of the first cylindrical portion, and enters the first cylindrical portion with a gap formed therein. The hole formed inside the third cylindrical portion penetrates the second member and is exposed to the outside. Similarly, the hole formed inside the first cylindrical portion penetrates the first member and is exposed to the outside. A gap between the inner peripheral surface of the first cylindrical portion and the outer peripheral surface of the third cylindrical portion is provided between each lock piece and a pair of lock pieces arranged at a distance from each other in the circumferential direction. A spring that urges each lock piece in a circumferential direction is disposed. A drive shaft that is rotatable coaxially with the third cylindrical portion is received inside the third cylindrical portion. The drive shaft includes a drive piece that extends in a radial direction from an outer portion of the projecting end of the third cylindrical portion and can push the lock piece in the circumferential direction.

  In the reclining mechanism configured as described above, in a normal state, the third cylindrical portion is pushed to one side in the first cylindrical portion by each lock piece biased by the spring, and the external gear and the internal gear The meshing position is maintained and the angle of the second member relative to the first member is maintained. When the drive shaft rotates, the drive piece pushes the lock piece to one side in the circumferential direction, and the third cylindrical portion pushed by the lock piece moves in the first cylinder portion in the circumferential direction. At this time, since the number of teeth of the external gear and the internal gear is different, the angle of the second member with respect to the first member changes as the third cylindrical portion moves in the circumferential direction. Thus, the angle of the second member with respect to the first member changes according to the amount of rotation of the drive shaft.

  The drive shafts of the first to third reclining mechanisms 41 to 43 are connected to each other by a connecting shaft 45 extending along the rotation axis X. Each drive shaft has a through hole, and the connecting shaft 45 extends through the through hole of each drive shaft. The connecting shaft 45 and the through hole of each driving shaft are coupled to each other by serration, and the connecting shaft 45 and the driving shaft rotate integrally. When the connecting shaft 45 rotates, the drive shafts of the first to third reclining mechanisms 41 to 43 rotate integrally, and the first to third reclining mechanisms R1 to R3 simultaneously change the rotation angle of the seat back S2 relative to the seat cushion S1. Change.

  As shown in FIGS. 7 to 9, a drive unit 47 for rotating the connecting shaft 45 is provided in the accommodating portion 37 formed on the inner side (right side) of the left backside frame 8. The drive device 47 includes an electric motor 47A and a speed reduction mechanism 47B that reduces the rotational force of the electric motor 47A and transmits it to the connecting shaft 45. The reduction mechanism 47B includes a known gear train such as a worm and a worm wheel. The speed reduction mechanism 47B is disposed on the right side of the first reclining mechanism 43 and the lower left backside frame 22, and the connecting shaft 45 passes through the speed reduction mechanism 47B. The electric motor 47A is provided on the upper side of the speed reduction mechanism 47B so that the rotation axis extends substantially vertically, and is disposed in front of the left end portion 11A of the back lower frame 11. Specifically, the speed reduction mechanism 47B is formed in a flat shape having a small left-right width with respect to the front-rear width, and the electric motor 47A is provided on the upper front side of the speed reduction mechanism 47B. For example, when the worm wheel included in the speed reduction mechanism 47B is arranged so that the axis of the worm wheel extends in the left-right direction, and connected to the rotation shaft of the electric motor 47A and meshes with the worm wheel, the worm wheel is arranged in front of the worm wheel. It becomes a form.

  The electric motor 47A includes a connector 47C to which a motor wire harness is connected. The connector 47 </ b> C is disposed on the outer surface of the motor housing 47 </ b> D and facing the left end 11 </ b> A side of the back lower frame 11. That is, the connector 47C is provided at the rear portion of the motor housing 47D, and is disposed between the motor housing 47D and the right end portion 11B of the back lower frame 11. Further, the connector 47C is arranged so that the connection portion faces upward.

  An intermediate portion of the motor wire harness is supported by a harness support member 49 provided at the left end portion 11 </ b> A of the back lower frame 11. The harness support member 49 has, for example, a plate piece welded to the back lower frame 11, and a wire harness is fastened to the plate piece by a fastening band or the like.

  As shown in FIGS. 6 to 9, an auxiliary frame 50 that protrudes downward is provided at the central portion 11 </ b> C of the back lower frame 11. The auxiliary frame 50 includes a frame portion 50A formed in a substantially rectangular frame shape, and a reinforcing portion 50B spanned over the frame portion 50A. The frame portion 50A is formed by bending a metal pipe, and forms a rectangular frame shape in cooperation with the central portion 11C of the back lower frame 11. The frame portion 50A is disposed such that the long side of the substantially rectangular shape is the lower edge, and is coupled to the central portion 11C of the back lower frame 11 by welding or the like at the upper portion. The reinforcing portion 50B is formed of a sheet metal member, and is arranged to vertically cut the frame portion 50A. The upper end portion is welded to the central portion 11C of the back lower frame 11, and the lower end portion is welded to the lower edge of the frame portion 50A. Has been.

  The auxiliary frame 50 is disposed behind the connecting shaft 45, and a lower end portion thereof is disposed below the connecting shaft 45. Moreover, the auxiliary | assistant frame 50 inclines back and forth so that a lower end part may be arrange | positioned ahead with respect to an upper end part. The lower edge of the auxiliary frame 50 constitutes the lower edge of the seat back.

  As shown in FIG. 2, the movable frame F <b> 3 includes a pair of left and right side frames 60 and an upper frame 61 that joins the upper ends of the left and right side frames 60. Each side frame 60 has an upper side frame 62 and a lower side frame 63, which are sheet metal members, and are formed symmetrically with each other.

  The upper side frame 62 extends vertically and has a side portion 62A whose main surface faces in the left-right direction, and smoothly curves from the upper end of the side portion 62A and extends inward in the left-right direction. It has a part 62B. The side portion 62A is bent at an intermediate portion in the vertical direction, and the upper portion is offset inward in the left-right direction with respect to the lower portion. Ribs 62C and 62D projecting inward in the left-right direction are extended from the front edge and the rear edge of the side part 62A so as to extend along the respective edges. The rib 62C extending along the front edge of the side part 62A is continuous with the upper edge of the upper side part 62B at the upper end of the side part 62A, and then extends along the upper edge. Further, a reinforcing wall 62E that protrudes inward in the left-right direction is formed at the rear edge of the upper half of the side portion 62A. The reinforcing wall 62E is continuous with the upper side part 62B and connects the corners of the side part 62A and the upper side part 62B. The side part 62A, the upper side part 62B, the rib 62C, and the reinforcing wall 62E are integrally formed by bending one sheet metal member.

  The upper frame 61 extends in the left-right direction, and faces the upper sides 62B of the left and right upper side frames 62 at the left and right ends. The left and right end portions of the upper frame 61 are smoothly curved forward and downward, and extend along the left and right inner surfaces of the side portions 62A of the left and right upper side frames 62. The upper frame 61 is coupled to the upper side part 62B and the side part 62A of the upper side frame 62 by welding or the like. The upper frame 61 is a sheet metal member having a groove shape in cross section, and is arranged so that the groove-shaped opening faces the side of the upper side portion 62B and the side portion 62A facing each other. Thereby, the upper frame 61 forms a closed cross-sectional structure in cooperation with the upper side portion 62B and the side portion 62A. A connecting pipe 65 is stretched between the lower portions of the left and right side portions 62A.

  As shown in FIGS. 2, 7, and 8, the lower side frame 63 is formed of a sheet metal member. The lower side frame 63 is arranged so as to extend in the up-down direction and the main surface faces in the left-right direction. The upper end portion of the lower side frame 63 is coupled to the outer surface in the left-right direction of the side portion 62A of the upper side frame 62 by bolt fastening or the like. The lower side frame 63 is bent at an intermediate portion in the vertical direction, and the lower end portion is offset outward in the left-right direction with respect to the upper end portion. In addition, the lower end portion of the lower side frame 63 is formed to have a large front-rear width with respect to the upper portion, and is attached to each back side frame so as to be rotatable (tilted) about a rotation axis extending in the left-right direction. Part).

  The shaft support 63A of the lower right side frame 63 on the right side is rotatably coupled to the upper right back side frame 13 (the right back side frame 9). A shaft support portion 63A of the left lower side frame 63 is coupled to the upper left back side frame 21 (left back side frame 8) via a fourth reclining mechanism 67 so as to be rotatable. The rotational axes of the lower side frames 63 are arranged coaxially, and are arranged between the pad support brackets 32 and 33 and the back lower frame 11 in the vertical direction.

  The fourth reclining mechanism 67 is provided between the first member coupled to the upper left back side frame 21, the second member coupled to the shaft support portion 63 </ b> A of the lower side frame 63, and the first member and the second member. And a drive shaft 67A for switching the coupling and separation between the first member and the second member by rotating. The fourth reclining mechanism 67 may be a known manual reclining mechanism. A specific example of such a reclining mechanism 67 will be described. In the reclining mechanism 67, the first member and the second member are arranged coaxially, and the drive shaft passes through the rotation centers of the first member and the second member. Is provided. The reclining mechanism is disposed in an internal space formed between the first member and the second member, and rotates with the drive shaft, a plurality of lock members disposed in the internal space, a cam And a biasing member such as a torsion spring that biases the plate in one rotational direction. The lock member engages with a guide groove formed in the first member and is arranged to be movable in the radial direction of the first member. The locking member has a cam portion at a radially inner portion, an outer tooth at a radially outer portion, and an inner peripheral surface that forms an inner space of the second member when moved radially outward. Engages with internal teeth formed along the circumferential direction. The cam plate engages with the lock member and moves the lock member radially outward when rotating in one rotation direction, and moves the lock member radially inward when rotating in the other rotation direction. . In the reclining mechanism configured as described above, in a normal state, the drive shaft is urged by the urging member and is in the lock position, and the lock member is engaged with the second member, and the first member and the second member are The locked position is locked. On the other hand, when the drive shaft rotates against the urging member and is in the release position, the lock member is separated from the second member, and a release state in which the first member and the second member can be rotated relative to each other is achieved.

  As shown in FIG. 6, the side portion 21 </ b> A of the upper left backside frame 21 has a bulging portion 21 </ b> E that bulges inward in the left-right direction at a portion facing the fourth reclining mechanism 67. The bulging portion 21E has a bulging amount that is substantially the same as the height of the ribs 21B and 21C, and its protruding end is formed in a plane that faces inward in the left-right direction. The back side of the bulging portion 21E is recessed corresponding to the shape of the bulging portion 21E. The left lower side frame 63 is arranged outside the groove shape of the upper left back side frame 21 by the bulging portion 21E. Thereby, the movable frame F3 can be tilted forward and backward without interfering with the ribs 21B and 21C of the upper left backside frame 21.

  As shown in FIGS. 2 and 6, the drive shaft 67A of the fourth reclining mechanism 67 passes through the bulging portion 21E and protrudes outward in the left-right direction of the side portion 21A. An extension shaft 70 is coupled to the tip of the drive shaft 67A. At the inner end of the extension shaft 70, a coupling hole 70A is formed in which the tip of the drive shaft 67A is fitted so as not to be relatively rotatable. The tip of the drive shaft 67A is preferably formed in a prismatic shape such as a rectangle or a square, for example, and the coupling hole 70A is preferably formed in a hole having a transverse cross section complementary to these prisms. The extension shaft 70 extends coaxially with the drive shaft 67A and extends outward in the left-right direction. The outer end of the extension shaft 70 is coupled to the operation lever 71. The operation lever 71 is formed with a coupling hole 71A into which the outer end of the extension shaft 70 can enter. Serrations 70B and 71B that engage with each other are formed on the outer peripheral surface of the outer end of the extension shaft 70 and the inner peripheral surface of the coupling hole 70A of the operation lever 71, respectively. The operation lever 71 is coupled to the drive shaft 67A via the extension shaft 70 and rotates together. Accordingly, the fourth reclining mechanism 67 can be switched between the locked state and the released state by manually operating the operation lever 71.

  As shown in FIG. 7, a mainspring spring 73 as an urging member is provided on the inner side in the left-right direction of the shaft support portion 63 </ b> A of the left lower side frame 63. The mainspring spring 73 is disposed coaxially with the rotation axis of the movable frame F3, and has one end coupled to the left lower side frame 63 and the other end coupled to the upper left backside frame 21. The mainspring spring 73 is biased in a direction in which the movable frame F3 tilts forward with respect to the seat back frame F2.

  As shown in FIG. 2, a pair of headrest mounting portions 75 for supporting the headrest is coupled to the upper frame 61. The headrest mounting portion 75 has a cylindrical shape, and a support (not shown) that is a resin cylindrical member is inserted therein. The headrest has a pair of headrest pillars (not shown), and is attached to the upper frame 61 by inserting the headrest pillar into the headrest attachment portion 75 via the support.

  The side frame 60 including the upper side frame 62 and the lower side frame 63 has at least one first weakened portion 77. The first fragile portion 77 locally lowers the rigidity of the side frame 60 and becomes a starting point of deformation when an external load is applied. The first fragile portion 77 is, for example, a cutout portion opened at a side edge of the member, a through hole formed in the member, a perforation in which the through holes are continuously arranged at a predetermined interval, and other portions. It may be a thin portion or the like where the thickness of the member is reduced.

  It is preferable that the 1st weak part 77 is arrange | positioned between the headrest attaching part 75 and 63 A of shaft support parts in the side frame 60. As shown in FIG. In the present embodiment, the first fragile portion 77 is disposed below the lower end of the upper frame 61 and above the upper end of the lower side frame 63 in the upper side frame 62. Further, the first fragile portion 77 is disposed above the connecting portion with the connecting pipe 65 in the upper side frame 62. The left and right first fragile portions 77 are arranged at the same vertical position.

  Moreover, the 1st weak part 77 is arrange | positioned in the position corresponding to the reinforcement wall 62E in an up-down direction. The reinforcing wall 62 </ b> E has a second fragile portion 78 at a portion corresponding to the first fragile portion 77. The 2nd weak part 78 is the structure similar to the 1st weak part 77 as mentioned above. Thereby, when a deformation | transformation arises from the 1st weak part 77 by an external load, the 2nd weak part 78 also deform | transforms and it is suppressed that the reinforcement wall 62E inhibits a deformation | transformation of the upper side frame 62.

  In this embodiment, the 1st weak part 77 is a notch part each formed in the upper side frame 62, and is extended so that it may reach the side part 62A from the protrusion end of the rib 62C of the front edge. The left and right cutout portions of the second weakened portion 78 are cutout portions formed in the reinforcing walls 62E, respectively, and extend upward from the lower edge of the reinforcing wall 62E above the first weakened portion 77 in the vertical direction. . The 2nd weak part 78 is so preferable that it is arrange | positioned near the side part 62A of each upper side frame 62 in the left-right direction. Due to the second fragile portions 78 of these configurations, the lower portion of the reinforcing wall 62E does not affect the rigidity of the upper side frame 62.

  The lower part of the reinforcing wall 62E constitutes a harness support part 62F for supporting the wire harness. The harness support portion 62F includes a through hole that penetrates the lower portion of the reinforcing wall 62E in the thickness direction. A wire harness is fastened to the harness support portion 62F by a fastening band or the like. The wire harness supported by the harness support part 62F is connected to a device such as a heater disposed on the upper portion of the seat back supported by the movable frame F3.

  First to sixth pad support members 81 to 86 for supporting the seat back pad are provided at appropriate positions of the movable frame F3 and the left and right back side frames 8 and 9, respectively. The pair of left and right first pad support members 81 are provided on the upper side frame 62, respectively. Each first pad support member 81 is formed by bending a bar-like member, and is welded to the upper side of the first weakened portion 77 of the upper side frame 62 and the first weakened portion of the upper side frame 62 on the same side. And a lower end welded to the lower side than the portion 77. Each first pad support member 81 has a middle portion in the longitudinal direction protruding forward and outward in the left-right direction with respect to the upper side frame 62. Each first pad support member 81 preferably has a sufficiently low rigidity with respect to the upper side frame 62 having the first fragile portion 77 and does not hinder the deformation of the upper side frame 62 starting from the first fragile portion 77. The first pad support member 81 has a plurality of bent portions serving as deformation starting points, and has low rigidity.

  The second pad support member 82 is bridged between the left and right upper side frames 62 between the upper frame 61 and the connecting pipe 65. The third pad support member 83 has both ends extending in the left-right direction and coupled to both ends of the connection pipe 65. An intermediate portion of the third pad support member 83 projects downward with respect to the connection pipe 65.

  The fourth pad support member 84 includes a first rod-shaped member 84A spanned between the left and right pad support brackets 32 and 33, and both end portions extending in the left-right direction and coupled to both end portions of the first rod-shaped member 84A. And a second bar-shaped member 84B. An intermediate portion of the second rod-shaped member 84B projects downward and forward with respect to the first rod-shaped member 84A.

  The fifth pad support member 85 is formed of a rod-like member, extends in the left-right direction, and has a right end portion coupled to the rear surface of the upper right back side frame 13 and a right end portion coupled to the rear surface of the upper right back side frame 13. . The left and right end portions of the fifth pad support member 85 are disposed behind the shaft support portion 63A of the movable frame F3. An intermediate portion in the left-right direction of the fifth pad support member 85 projects forward with respect to both end portions.

  The sixth pad support member 86 is formed of a rod-like member and extends vertically, and has an upper end portion and a lower end portion that are welded to the rib 21B on the front edge of the upper left side frame. The upper end portion of the sixth pad support member 86 is disposed above the shaft support portion 63A in the vertical direction, and the lower end portion is disposed below the shaft support portion 63A. The middle part of the sixth pad support member 86 projects rightward with respect to the upper left side frame and is disposed so as to cover the front of the mainspring spring 73.

  On the left side surface of the upper right backside frame 13, a protection member 88 is provided to protect the right shaft support portion 63A of the movable frame F3. The protection member 88 has a lower end welded to a lower portion of the left side surface of the upper right backside frame 13 than the shaft support 63A, and an upper end extending to the left of the shaft support 63A to form a free end. . In the present embodiment, the protection member 88 is formed by bending a rod-shaped member, and both end portions thereof form a lower end portion and the intermediate portion forms an upper end portion.

  As shown in FIGS. 2, 8 and 9, the back lower frame 11 and the fifth pad support member 85 are connected by a connecting member 89. The connecting member 89 is formed by bending a rod-shaped member. The connecting member 89 includes one end welded to the central portion 11C of the back lower frame 11, a connecting portion 89A extending up and down from the one end to the fifth pad support member 85, and left and forward from the upper end of the connecting portion 89A. After projecting, it has a restricting portion 89B that bends and extends vertically. The connecting member 89 is welded to the fifth pad support member 85 at a portion between the connecting portion 89A and the restricting portion 89B. The restricting portion 89B is disposed on the right side of the mainspring spring 73 and restricts the access of the other components to the mainspring spring 73 and the shaft support portion 63A of the movable frame F3.

  As shown in FIGS. 2 and 7 to 9, a bracket 91 is coupled to the rib 21 </ b> C at the rear edge of the upper left backside frame 21 below the portion to which the fifth pad support member 85 is coupled. The bracket 91 is a sheet metal member and extends to the right along the fifth pad support member 85. The upper edge of the bracket 91 is bent forward and locked to the fifth pad support member 85. The bracket 91 is disposed behind the connecting member 89, and a right end portion thereof extends to a position corresponding to the connecting portion 89A of the connecting member 89, and is welded to the connecting portion 89A. The bracket 91 configured in this manner covers the rear of the shaft support 63A and the mainspring spring 73 of the movable frame F3, and restricts the access of other components to the shaft support 63A and the mainspring spring 73 of the movable frame F3.

  The bracket 91 is formed with a guide hole 91A penetrating in the front-rear direction. The wire harness extending into the upper part of the seat back constituted by the movable frame F3 is disposed so as to pass through the guide hole 91A from the rear side to the front side and then to the right side of the restricting portion 89B of the connecting member 89. The As a result, the approach of the wire harness to the shaft support portion 63 </ b> A of the movable frame F <b> 3 and the mainspring spring 73 is restricted by the bracket 91 and the connecting member 89.

  Hereinafter, the effect of the sheet S configured as described above will be described. In the seat S, the upper part of the left backside frame 8 and the reinforcing member 30 cooperate to form a closed cross-sectional structure, so that the rigidity of the left backside frame 8 is increased and deformation is suppressed. Thereby, the external load applied to the upper part of the seat back frame F2 is efficiently applied to the seat cushion frame F1 from the back upper frame 10 via the left and right back side frames 8 and 9 and the first to third reclining mechanisms 41 to 43. Be transmitted. Moreover, since the lower part of the left back side frame 8 becomes an open cross-sectional structure, the left back side frame 8 can be made thin and compact. In addition, other components and devices such as the drive device 47 including the electric motor 47A can be arranged inside the left backside frame 8.

  Since the back upper frame 10 and the left back side frame 8 are smoothly connected by the curved portion 23, the stress concentration on the connecting portion of the back upper frame 10 and the left back side frame 8 is suppressed. Further, since the curved portion 23 is reinforced by the reinforcing member 30, the deformation of the connecting portion between the back upper frame 10 and the left back side frame 8 is further suppressed.

  Since the upper left back side frame 21 forms the curved portion 23, the three-dimensional structure of the curved portion 23 increases the sectional moment (stiffness) of the upper left back side frame 21 that is a sheet metal member. Further, since the cross section of the curved portion 23 is formed in a groove shape, and the reinforcing member 30 is formed in a groove shape that fits into the curved portion 23 and forms a closed cross section together with the curved portion 23, the reinforcing member 30 and the curved portion The rigidity of the closed cross-sectional structure formed by the portion 23 is increased.

  Since the connecting portion of the back upper frame 10 and the upper left back side frame 21 and the connecting portion of the back upper frame 10 and the reinforcing member 30 are offset from each other in the left-right direction, the left end portion of the back upper frame 10 and the reinforcing member 30 Are engaged with the upper end of the upper left backside frame 21 to which are connected. Thereby, the rigidity of the joint portion between the back upper frame 10 and the upper left back side frame 21 is increased.

  Since the upper left back side frame 21 is formed in a groove shape that opens inward (rightward) in the left-right direction, other members such as the drive device 47 including the electric motor 47A are provided inside the upper left back side frame 21. Is formed. As a result, the other members are protected by the upper left back side frame 21 and are difficult to receive a load from the outside.

  Since the lower end of the reinforcing member 30 extends to a position facing the positioning hole 31, a portion of the upper left back side frame 21 whose rigidity is lowered by the positioning hole 31 is reinforced by the reinforcing member 30.

  Since the lower end of the reinforcing member 30 is spaced above the pad support bracket 32, a space is formed between the pad support bracket 32 and the reinforcing member 30, and a space is secured around the pad support bracket 32. Is done. As a result, the seat back pad can be disposed around the pad support bracket 32, and the engagement area between the pad support bracket 32 and the seat back pad can be increased.

  Since the shaft support portion 63A of the movable frame F3 is disposed in the open cross-section structure portion of the upper left backside frame 21, the movable frame F3 and the upper left backside frame 21 can be efficiently disposed.

  Since the sixth pad support member 86 that restricts the movement of the seat back pad is disposed so as to surround the shaft support portion 63A of the movable frame F3, contact between the seat back pad and the shaft support portion 63A can be avoided.

  Since the two reclining mechanisms 42 and 43 are provided at the connecting portion between the right back side frame 9 and the seat cushion frame F1, the rigidity of the connecting portion between the right back side frame 9 and the seat cushion frame F1 is enhanced. As a result, the external load applied to the seat back frame F2 is transmitted to the seat cushion frame F1 mainly through the right back side frame 9 and the second and third reclining mechanisms 42 and 43, and is transformed into the upper left back side frame 21. Is less likely to occur.

  Since the belt guide 16 is provided at the upper end portion of the right back side frame 9, external loads applied to the seat back frame F2 via the seat belt and the belt guide 16 are mainly the right back side frame 9, the second and second 3 is transmitted to the seat cushion frame F1 via the reclining mechanisms 42 and 43.

  Since the back lower frame 11 is arranged with the left end portion 11 </ b> A offset rearward with respect to the right end portion 11 </ b> B, the accommodating portion 37 is formed in front of the left end portion 11 </ b> A and inside the lower portion of the upper left backside frame 21. That is, the upper right back side frame 13 and the upper left back side frame 21 can be coupled by the back lower frame 11 while avoiding the accommodating portion 37 in which other members such as the electric motor 47A are disposed.

  Since the left end portion 11A of the back lower frame 11 is offset in a direction away from the back portion of the occupant seated on the seat S, the occupant seated on the seat S is prevented from feeling uncomfortable. Further, by providing the protruding portion 21D, the amount of offset to the rear of the left end portion 11A of the back lower frame 11 can be increased. Further, when at least a part of the left end portion 11A of the back lower frame 11 is coupled to the protruding portion 21D, the amount of offset to the rear of the left end portion 11A of the back lower frame 11 is further increased.

  Since the center part 11C corresponding to a passenger | crew's back part is formed in the left-right symmetrical form, the back lower frame 11 is suppressed from giving a passenger discomfort. Further, the central portion 11C of the back lower frame 11 is disposed below and behind the left end portion 11A and the right end portion 11B, and a distance is secured between the back portion of the occupant, so that the occupant is prevented from feeling uncomfortable. The

  By arranging the electric motor 47A in the accommodating portion 37 formed inside the upper left back side frame 21, the electric motor 47A can be efficiently accommodated in the seat back using the open cross-sectional structure of the upper left back side frame 21. Can do. Further, since the electric motor 47A is disposed inside the upper left backside frame 21, it is possible to prevent a load from being applied from the outside. Further, since the connector 47C is disposed between the housing and the back lower frame 11, it is possible to prevent a load from being applied from the outside.

  Since the motor wire harness connected to the electric motor 47A is supported on the left end 11A side of the back lower frame 11 close to the connector 47C, the swing of the motor wire harness is suppressed.

  Since the auxiliary frame 50 provided in the back lower frame 11 is disposed below the drive shaft and the connecting shaft 45 of the first to third reclining mechanisms 41 to 43, the lower end portion of the seat back is held by the auxiliary frame 50. Shaped. In the automobile production line, in order to move the sheet S, the lower end of the seat back may be supported by a hanger device. In this case, since the auxiliary frame 50 exists at the lower end portion of the seat back, the load of the seat S is applied to the hanger device via the auxiliary frame 50, and deformation of the seat back is suppressed. Further, a load applied to the seat back from below is applied to the auxiliary frame 50 and is prevented from being applied to the drive shaft and the connection shaft 45, so that deformation of the drive shaft and the connection shaft 45 is suppressed.

  Since the auxiliary frame 50 is disposed behind the drive shaft and the connecting shaft 45, that is, at a position away from the occupant, the occupant is prevented from feeling uncomfortable.

  Since the connecting member 89 protruding upward is provided on the back lower frame 11 and the swing of the wire harness extending to the upper part of the seat back constituted by the movable frame F3 is restricted by the restricting portion 89B of the connecting member 89, the shaft of the movable frame F3 The approach of the wire harness to the support 63A, the mainspring spring 73, and the fourth reclining mechanism 67 can be suppressed.

  Since the movable frame F3 has the first fragile portion 77, the movable frame F3 is deformed starting from the first fragile portion 77 when a predetermined external load is applied to the movable frame F3 or the headrest connected to the movable frame F3. The shock is absorbed. For example, when the occupant of the seat S or the occupant of the seat disposed behind the seat S collides with the upper part of the seat back constituted by the movable frame F3 or the headrest due to a vehicle collision or the like, the movable frame F3 is The first fragile portion is deformed to absorb the impact, and the impact applied to the occupant is reduced.

  Since the first fragile portion 77 is provided between the headrest mounting portion 75 and the shaft support portion 63A, when an external load is applied to the headrest, the movable frame F3 is reliably bent from the first fragile portion 77 as a starting point. be able to.

  Since the first fragile portion 77 is formed at the front edge of the side frame 60 of the movable frame F3, when an external load is applied to the movable frame F3 from the rear, the movable frame F3 bends forward and impacts. Can be absorbed. Thereby, when the passenger | crew of the sheet | seat arrange | positioned behind the sheet | seat S collides with the upper part of the seat back comprised by the movable frame F3, or a headrest, the impact added to a passenger | crew is reduced.

  The rigidity of the side frame 60 of the movable frame F3 is increased by having the rib 62C. On the other hand, since the first fragile portion 77 is formed by the cutout portion extending from the rib 62C to the side portion 62A, the rigidity difference between the first fragile portion 77 and the other portion in the side frame 60 is increased. Thereby, the movable frame F3 can be reliably bent with the first fragile portion 77 as a starting point.

  The rigidity of the joint portion between the side frame 60 and the upper frame 61 is enhanced by the reinforcing wall 62E. Further, since the reinforcing wall 62E has the second fragile portion 78 at a position corresponding to the first fragile portion 77 in the vertical direction, the side frame 60 is not hindered by the reinforcing wall 62E, and the first fragile portion 77 is the starting point. It can be deformed. The second fragile portion 78 extends from the lower edge of the reinforcing wall 62E to the upper side of the first fragile portion 77 in the vertical direction, and corresponds to the first fragile portion 77 in a wide range. The frame F3 is reliably deformed without being obstructed by the reinforcing wall 62E. Moreover, since the harness support part 62F is provided in the reinforcement wall 62E, rocking | fluctuation of the wire harness arrange | positioned at the upper part of a seat back is suppressed.

  Since the connection pipe 65 is stretched over the left and right side frames 60 of the movable frame F3, and the first weakened portion 77 is provided above the connection pipe 65, the lower side of the side frame 60, that is, the seat back frame F2 The rigidity of the connecting portion side is increased by the connecting pipe 65. Further, since the rigidity of the first fragile portion 77 is lower than that of the lower side of the side frame 60, the deformation when an external load is applied is more reliably started from the first fragile portion 77.

  The first pad support member 81 is coupled to the side frame 60 so as to straddle the first fragile portion 77. However, since the first pad support member 81 has a bent portion that is a starting point of deformation, it is possible to suppress the deformation of the side frame 60 when the side frame 60 is deformed starting from the first fragile portion 77. .

  By providing the extension shaft 70, the operation lever 71 can be disposed outside the seat back frame F2 away from the drive shaft 67A of the fourth reclining mechanism 67. As a result, even when the upper left back side frame 21 is covered with a covering such as a seat back pad, the operation lever 71 is disposed on the outer side of the covering to enable manual operation. Since the extension shaft 70 and the operation lever 71 are connected by the serrations 70B and 71B, the connection structure of the operation lever 71 and the extension shaft 70 is strengthened, and the rotation of the operation lever 71 is reliably transmitted to the extension shaft 70. .

  Although the description of the specific embodiment is finished as above, the present invention is not limited to the above embodiment and can be widely modified. For example, in the above-described embodiment, an example in which welding is employed as an example for joining the members has been described. However, a portion to be joined by welding is known in the art such as joining by a rivet, friction stir welding, and adhesion by an adhesive. It can be replaced with a combination technique. The sheet S may be configured as a symmetrical shape with the left and right being exchanged.

  The curved portion 23 formed integrally with the upper left back side frame 21 may be formed integrally with the back upper frame 10 instead of the upper left back side frame 21. Further, the left end portion of the front member 26 of the back upper frame 10 is disposed to the right of the left end portion of the rear member 27 so that the end portion of the reinforcing member 30 is fitted inside the front side of the rear member 27. May be.

  In the above embodiment, the left end portion 11A of the back lower frame 11 is offset backward with respect to the right end portion 11B. However, in other embodiments, the left end portion 11A is above the right end portion 11B. You may offset in arbitrary directions, such as downward and the front. The accommodating portion 37 is formed on the side opposite to the offset direction of the left end portion 11A. Further, the storage unit 37 may store other devices, parts, and the like different from the drive device 47.

  In the above embodiment, the central portion 11C of the back lower frame 11 has a shape extending linearly in the left-right direction. In other embodiments, the central portion 11C has other shapes such as an arc shape protruding backward. May be.

  In the above embodiment, the auxiliary frame 50 has a substantially rectangular outer shape. However, in other embodiments, the auxiliary frame 50 may have an arbitrary outer shape. In this case, the lower edge of the auxiliary frame 50 may be disposed below the connecting shaft 45.

  In the above embodiment, the first weakened portion 77 is provided at the front edge of the upper side frame 62, but may be provided at the rear edge of the upper side frame 62 in other embodiments. In this case, the movable frame F3 can be deformed rearward with respect to the load from the front, and can absorb the impact.

  In the above embodiment, the coupling structure of the extension shaft 70 and the operation lever 71 is the engagement structure by the serrations 70B and 71B, but may be replaced with another known coupling structure.

  In the above embodiment, an example in which the present invention is applied to a vehicle seat has been described. However, the seat according to the present invention can also be applied to various seats for aircraft, railways, and the like. In addition, all the components of the sheet S shown in the above embodiment are not necessarily essential, and can be selected as appropriate.

8: Left back side frame 9: Right back side frame 10: Back upper frame 11: Back lower frame 13: Upper right back side frame 14: Lower right back side frame 16: Belt guide 21: Upper left back side frame 21D: Projection 22 : Lower left back side frame 23: curved portion 31: positioning hole 32: left pad support bracket 37: housing portion 41: first reclining mechanism 42: second reclining mechanism 43: third reclining mechanism 45: connecting shaft 47: driving device 47A : Electric motor 47C: Connector 47D: Motor housing 49: Harness support member 50: Auxiliary frame 60: Side frame 61: Upper frame 62: Upper side frame 62E: Reinforcement wall 62F: Harness support part 63: Lower side wall 65: connecting pipe 67: fourth reclining mechanism 67A: drive shaft 70: extension shaft 71: operation lever 77: first fragile portion 78: second fragile portion 81: first pad support member 85: fifth pad support member 86: 6th pad support member 88: Protection member 89: Connection member 89A: Connection part 89B: Restriction part 91: Bracket 91A: Guide hole F1: Seat cushion frame F2: Seat back frame F3: Movable frame S: Seat

Claims (11)

First and second side frames each having a lower end coupled to a seat cushion frame; an upper frame spanned between upper portions of the first and second side frames; and the first and second side frames. A seat back frame including a lower frame spanned between the lower portions;
The first end of the lower frame coupled to the first side frame is disposed to be offset from front to back or up and down with respect to the second end coupled to the second side frame. An accommodating portion is formed on the lower inner side of the one side frame and on the side opposite to the offset direction of the first end,
A first reclining mechanism is provided between the first side frame and the seat cushion frame,
An electric motor that drives the first reclining mechanism is disposed in the housing portion,
The electric motor is disposed in front of the first end portion in the housing portion, and opposed to the first end portion in the front-rear direction.
A vehicle seat, wherein a front edge of the electric motor is arranged behind a front edge of the first side frame. The first side frame has a protruding portion that protrudes rearward from a corresponding portion at the top and bottom of the second side frame,
2. The vehicle seat according to claim 1, wherein the first end portion is arranged to be offset toward the protruding portion side with respect to the second end portion.   The vehicle seat according to claim 2, wherein at least a part of the first end portion is coupled to the protruding portion.   The lower frame has a left and right central portion formed in a bilaterally symmetric shape, and the first end portion and the second end portion are different in shape so that the first end portion is different from the second end portion. The vehicle seat according to any one of claims 1 to 3, wherein the vehicle seat is offset.   The vehicle seat according to claim 4, wherein a central portion of the lower frame is disposed below and rearward of the first end portion and the second end portion. The electric motor has a housing and a connector to which the first wire harness is connected,
The vehicle seat according to any one of claims 1 to 5, wherein the connector is provided at a portion of the outer surface of the housing facing the first end portion.   The vehicle seat according to claim 6, wherein a harness support portion for supporting the first wire harness is provided on the first end portion side of the lower frame. An auxiliary frame that protrudes downward is provided at the center in the left-right direction of the lower frame,
The vehicle seat according to any one of claims 5 to 7, wherein a lower end of the auxiliary frame is disposed below a rotation center of the first reclining mechanism. A second reclining mechanism is provided between the second side frame and the seat cushion frame;
The first and second reclining mechanisms include a first member coupled to the seat cushion frame, a second member coupled to the first and second side frames, the first member and the second member, Each having a drive shaft that switches between coupling and separation of the first member and the second member by rotating,
Each of the drive shafts are arranged coaxially with each other and connected to rotate integrally with each other,
The vehicle seat according to claim 8, wherein a lower end of the auxiliary frame is disposed below the drive shaft.   The vehicle seat according to claim 9, wherein the auxiliary frame is disposed behind the drive shaft. A movable frame coupled to the first and second side frames so as to be tiltable about a pivot shaft disposed above the lower frame to correspond to the upper back of the occupant;
A second wire harness extending toward the movable frame;
11. The apparatus according to claim 1, further comprising a regulating member provided so as to protrude upward from the lower frame and regulating swinging of the second wire harness. Vehicle seats.

Images