JP2014108708A - Vehicle seat - Google Patents

Abstract

PROBLEM TO BE SOLVED: To tilt a movable member with a simple structure.SOLUTION: The vehicle seat comprises: a front link 71 disposed on a side frame so as to rotate freely around a front side fixing axis 71A; a rear link 72 disposed on the side frame so as to rotate freely around a rear side fixing axis 72A; a movable member 20 supported by the front link 71 and the rear link 72; and a transmission mechanism 30 for transmitting tilting operation of a seat back S2 to the movable member 20. In a standard posture, a front side movable axis 71B is disposed above the front side fixing axis 71A, and a rear side movable axis 72B is disposed below the rear side fixing axis 72A. At an initial stage where the seat back S2 tilts to a rear tilting posture from the standard posture, tilting tendency of the movable member 20 is configured so that a front end is lifted up relatively to a rear end, which is first tendency.

Description

  The present invention relates to a vehicle seat including a seat cushion and a seat back tiltable with respect to the seat cushion.

  Conventionally, a movable member (seat cushion frame 50) that supports the seat cushion, a side frame (base frame 12) that supports the movable member so as to be able to move forward and backward, and a tilting operation of the seat back are transmitted to the movable member. In addition, a vehicle seat provided with a transmission mechanism (first link 54) connected to a movable member and a seat back is known (see Patent Document 1).

  Specifically, in this technique, a wedge-shaped cam member 70 having a tapered front end is provided on the front side of the movable member, and the cam member 70 is supported by a roller 71 rotatably provided on a side frame. Further, the rear side of the movable member is supported from below by a second link 55 rotatably provided on the side frame.

  In this technique, the transmission mechanism tilts the second link 55 forward in conjunction with the operation of tilting the seat back later, so that the movable member tilts so that the front end faces upward.

JP 7-257242 A

  However, in the conventional structure, since the movable member is tilted by the cam member 70, the roller 71, and the second link 55, there is a problem that the structure is complicated.

  Therefore, an object of the present invention is to tilt the movable member with a simple structure.

  Another object of the present invention is to bring the movable member and the seat back closer to a substantially flat state.

  The present invention for solving the above-described problems is a vehicle seat including a seat cushion and a seat back tiltable with respect to the seat cushion, and the left and right side frames constituting the left and right frames of the seat cushion. And a front link provided on the side frame so as to be rotatable about a front side fixed shaft, and disposed at a rear side of the front link and rotated on the side frame about a rear side fixed shaft. A rear link that is movably connected to the front link so as to be rotatable about a front side movable shaft, and a movable that is connected to the rear link so as to be rotatable about a rear side movable shaft. A transmission device coupled to the movable member and the seat back for transmitting the member and the tilting motion of the seat back to the movable member The front movable shaft is disposed above the front fixed shaft and the rear movable shaft is lower than the rear fixed shaft in a reference posture in which the seat back stands up at a predetermined angle. At least in an initial stage until the seat back tilts to the rearward tilt position where the seatback tilts most rearward from the reference posture, the tilting tendency of the movable member is such that the front end portion is relative to the rear end portion. It is comprised so that it may become the 1st tendency to raise relatively.

  According to this configuration, the movable member can be tilted with a simple structure as compared with the conventional structure in which the movable member is tilted by the cam member 70, the roller 71 and the second link 55.

  In the above-described configuration, the tilting tendency of the movable member is changed from the first tendency to the rear end from the first tendency until the seat back tilts to the rearward tilting position tilted most rearward from the reference posture. The front link and the rear link can be arranged so as to switch to a second tendency of lowering relative to the part.

  According to this, when the seat back is tilted from the reference posture toward the backward leaning posture, the angle of the movable member with respect to the horizontal plane gradually increases at the first stage where the movable member tilts in the first tendency. In the stage after the movable member tilts in the second tendency, it gradually becomes smaller. As a result, when the seat back is tilted backward, both the movable member and the seat back can be brought into a substantially flat state, so that the occupant can stretch and rest comfortably on the substantially flat vehicle seat. Can be obtained.

  Further, in the above-described configuration, the front-side movable shaft has the front-side fixed shaft behind the first vertical surface passing through the front-side fixed shaft and rearward of the front-side fixed shaft in the reference posture. It can arrange | position in the position close | similar to the 1st horizontal surface to pass.

  According to this, when the front side movable shaft is moved forward and obliquely upward, the front side movable shaft can be increased in the first stage (the amount of increase relative to the unit rotation angle), and the front side Since the amount of ascent of the front movable shaft can be kept small at a stage after the movable shaft is closer to the first vertical plane than the first horizontal plane, the tilting tendency of the movable member is improved from the first tendency to the second tendency. You can switch to

  In the above-described configuration, the rear-side movable shaft may be disposed at a position closer to the second vertical plane that passes through the rear-side fixed shaft than the second horizontal plane that passes through the rear-side fixed shaft in the reference posture. it can.

  According to this, when the rear side movable shaft is moved forward, the rear side movable shaft can be kept small in the first stage, and the rear side movable shaft can be kept small. Since the rising amount of the rear movable shaft can be increased at a stage after the second vertical surface is closer to the second horizontal plane, the tilting tendency of the movable member is favorably switched from the first tendency to the second tendency. be able to.

  In the above-described configuration, the rear-side movable shaft can be disposed in front of the second vertical surface in the reference posture.

  According to this, since the rising amount of the rear side movable shaft at a later stage when the rear side movable shaft is moved forward can be increased, the tilting tendency of the movable member is changed from the first tendency to the second tendency. It can be switched well depending on the tendency.

  According to the present invention, since the movable member can be tilted only by the front link and the rear link, the movable member can be tilted with a simple structure as compared with the conventional structure.

  In addition, according to the present invention, the front of the movable member is switched from the first tendency to the second tendency until the seat back is tilted to the rearward tilting position tilted most rearward from the reference posture. By arranging the link and the rear link, both the movable member and the seat back can be brought into a substantially flat state when the seat back is tilted backward.

  Further, according to the present invention, the tilting tendency of the movable member can be favorably switched from the first tendency to the second tendency by arranging the front side movable shaft behind the front side fixed shaft in the reference posture. Thus, both the movable member and the seat back can be brought into a substantially flat state.

  Further, according to the present invention, the rear-side movable shaft is arranged at a position closer to the vertical plane that passes through the rear-side fixed shaft than the horizontal plane that passes through the rear-side fixed shaft in the reference posture. Since the first tendency can be favorably switched from the second tendency, both the movable member and the seat back can be brought into a substantially flat state.

  Further, according to the present invention, the rear side movable shaft can be favorably switched from the first tendency to the second tendency by arranging the rear side movable shaft in front of the vertical plane in the reference posture. Both the movable member and the seat back can be brought into a substantially flat state.

1 is a perspective view of a vehicle seat as a vehicle seat according to a first embodiment. It is a perspective view which shows the seat frame of the state which fell the seat back. It is a top view which shows the right side part of a seat cushion frame. It is II sectional drawing (a) of FIG. 3, and II-II sectional drawing (b). It is a side view which shows a transmission mechanism. It is a figure which shows simply the state of the transmission mechanism, each link, and movable member at the time of a reference posture. It is a figure which shows simply the state of a transmission mechanism, each link, and a movable member when a seat back is inclined 43 degrees back with respect to a vertical plane. It is a figure which shows simply the state of a transmission mechanism, each link, and a movable member when a seat back is inclined 60 degrees back with respect to a vertical plane. It is a figure which shows simply the state of a transmission mechanism, each link, and a movable member when a seat back is inclined 70 degrees back with respect to a vertical plane. It is a figure which shows simply the state of a transmission mechanism, each link, and a movable member when a seat back is inclined 81 degrees back with respect to a vertical plane. It is a figure which shows simply the state of a transmission mechanism, each link, and a movable member when a seat back is inclined 13 degrees ahead (10 degrees with respect to a vertical surface) with respect to a reference position. It is a figure which shows simply the state of a transmission mechanism, each link, and a movable member when a seat back is inclined 23 degrees ahead (0 degree with respect to a vertical surface) with respect to a reference position. It is a figure which shows simply the state of a transmission mechanism, each link, and a movable member when a seat back is inclined 33 degrees ahead (-10 degrees with respect to a vertical surface) with respect to a reference | standard attitude | position. It is a figure which shows simply the mechanism which concerns on 2nd Embodiment, and is a figure which shows the state at the time of a reference posture. It is a figure which shows simply the state of a mechanism when a seat back is inclined 60 degrees back with respect to a vertical plane. It is a figure which shows simply the state of a mechanism when a seat back is inclined 81 degrees back with respect to a vertical plane. It is a figure which shows simply the mechanism which concerns on 3rd Embodiment, and is a figure which shows the state at the time of a reference | standard posture. It is a figure which shows simply the state of a mechanism when a seat back is inclined 60 degrees back with respect to a vertical plane. It is a figure which shows simply the state of a mechanism when a seat back is inclined 81 degrees back with respect to a vertical plane.

  Next, a first embodiment of the present invention will be described in detail with reference to the drawings as appropriate. In the following description, first, the overall configuration of a vehicle seat as an example of a vehicle seat will be briefly described, and then the characteristic part of the present invention will be described in detail.

  As shown in FIG. 1, the vehicle seat S is a seat used for a driver's seat of an automobile, and mainly includes a seat cushion S1, a seat back S2, and a headrest S3.

  A seat frame F as shown in FIG. 2 is built in the seat cushion S1 and the seat back S2. The seat frame F is mainly composed of a seat cushion frame F1 constituting a frame of the seat cushion S1 and a seat back frame F2 constituting a frame of the seat back S2. The seat cushion S1 is configured by covering a seat cushion frame F1 with a seat cushion pad made of a cushion material such as urethane foam and a skin material made of synthetic leather or fabric, and the seat back S2 is placed on the seat back frame F2. It is configured by covering a seat back pad made of a cushion material and a skin material made of synthetic leather or fabric.

  The lower portion of the seat back frame F2 is rotatably connected to the rear portion of the seat cushion frame F1 via a reclining mechanism RL. As a result, the seat back S2 can tilt forward and backward with respect to the seat cushion S1.

  Here, in FIG. 2, a state in which the seat back frame F <b> 2 is tilted most rearward with respect to the seat cushion frame F <b> 1 (rear tilt posture described later) is illustrated. In this specification, front and rear, left and right, and top and bottom are based on an occupant seated on the vehicle seat S in a state where the seat back S2 is not tilted by the reclining mechanism RL (reference state described later).

Next, the seat cushion frame F1 will be described in detail.
As shown in FIGS. 2 to 4, the seat cushion frame F <b> 1 performs left and right side frames 10, a movable member 20 that can move back and forth with respect to the left and right side frames 10, and a tilting operation of the seat back frame F <b> 2. In order to transmit to the movable member 20, the transmission mechanism 30 connected with the movable member 20 and the seat back frame F2 is provided.

  The left and right side frames 10 are metal frames extending in the front-rear direction, and are spaced apart from each other on the left and right. The side frame 10 includes a first side wall portion 11 that forms a side surface of the side frame 10, and a first flange portion 12 that extends inward in the left-right direction from the periphery of the first side wall portion 11. In addition, the front end portion 13 that is a portion on the front end side of the side frame 10 is formed to extend in the front-rear direction, and the rear side portion 14 that is a portion on the rear side of the front end portion 13 is the front end portion 13. It is formed so as to extend rearward after being bent outward from the rear end in the left-right direction. Then, one inner frame 40 (only one is shown) that extends in the front-rear direction and is connected to the side frame 10 is provided inside each of the left and right side frames 10 in the left-right direction.

  The inner frame 40 includes a second side wall portion 41 that forms a side surface of the inner frame 40, and a second flange portion 42 that extends outward from the periphery of the second side wall portion 41 in the left-right direction. And the front end part 43 which is a part of the front end side among the inner frames 40 is formed so as to extend along the front-rear direction, and is directly joined to the front end part 13 of the side frame 10 by welding.

  In addition, the rear side portion 44 that is a portion on the rear side of the front end portion 43 of the inner frame 40 is formed to bend inward in the left-right direction from the rear end of the front end portion 43 and then to extend rearward. The frame 10 is spaced apart from the rear side portion 14 in the left-right direction. The rear end portion of the rear side portion 44 is indirectly joined to the rear end portion of the side frame 10 via the connection beam 51. Here, the connecting beam 51 is a cylindrical member having a substantially rectangular cross-sectional view extending in the left-right direction, and both ends thereof are joined to the left and right side frames 10.

  Since the inner frame 40 is connected to the side frame 10 in this way, the side frame 10 can be reinforced by the inner frame 40, so that the rigidity of the side frame 10 can be improved. Further, by disposing the inner frame 40 that reinforces the side frame 10 on the inner side in the left-right direction of the side frame 10, for example, the vehicle seat S can be downsized in the left-right direction compared to a structure in which a reinforcing member is provided on the outer side of the side frame. It is possible.

  Further, by directly joining the front end portion 13 of the side frame 10 and the front end portion 43 of the inner frame 40, for example, the movement of the transmission mechanism 30 to be described later is compared to a structure in which the side frames and the rear end portions of the inner frame are directly joined. However, since it can be prevented from being obstructed by the joint portion J between the side frame 10 and the inner frame 40, the transmission mechanism 30 can be operated satisfactorily.

  Further, the joint portion J formed by directly joining the front end portion 13 of the side frame 10 and the front end portion 43 of the inner frame 40 has a closed cross-sectional structure as shown in FIG. Specifically, the joint portion J includes the front end portions of the first side wall portion 11 and the first flange portion 12 of the side frame 10 and the front end portions of the second side wall portion 41 and the second flange portion 42 of the inner frame 40. It is comprised by the side part, and it is comprised so that it may become a closed cross-section structure by joining the front-end side part of the 1st flange part 12, and the front-end side part of the 2nd flange part 42 by welding.

  Thus, by making the junction part J into a closed cross-section structure, the rigidity of the junction part J can be improved, and as a result, the rigidity of the side frame 10 can be improved.

  Such a closed cross-sectional structure is also applied to the seat back frame F2, as shown in FIG. That is, the seat back frame F2 includes an outer back frame F3 disposed on the outer side in the left-right direction and an inner back frame F4 disposed on the inner side in the left-right direction, and the outer back frame F3 is the same as the outer back frame F3. It has a third side wall portion F31 that forms a side surface, and a third flange portion F32 that extends inward in the left-right direction from the periphery of the third side wall portion F31, and the inner back frame F4 defines the side surface of the inner back frame F4. It has the 4th side wall part F41 to form, and the 4th flange part F42 extended to the left-right direction outer side from the periphery of the 4th side wall part F41. And each flange part F31 and F41 are joined by welding.

  The seat back frame F2 having a closed cross-sectional structure in this manner is disposed between the side frame 10 and a first transmission link 31 described later.

  The left and right joints J provided to the left and right side frames 10 and the left and right inner frames 40 are connected by a cylindrical connection pipe 52 extending in the left-right direction. Thereby, since the rigidity of the right and left joint J can be further improved, the rigidity of the side frame 10 can be further improved.

  Also, a bracket 60 that holds the side frame 10 and the inner frame 40 so as to be sandwiched in the left-right direction is joined to the lower side of the side frame 10 and the inner frame 40, specifically, near the rear end of the joint portion J by welding. Yes. The bracket 60 has a plate-like base 61 that extends from the laterally outer side of the side frame 10 to the laterally inner side of the inner frame 40, and extends upward from the front end of the base 61 to sandwich the joint J. The first sandwiching portion 62 and the second sandwiching portion 63 that extends upward from the rear end of the base portion 61 and sandwiches a portion other than the joint portion J are integrally provided.

  As shown in FIG. 4A, the first sandwiching portion 62 has a groove 62A having a width substantially the same as the width in the left-right direction of the joint portion J, and sandwiches the joint portion J in the groove 62A. Yes. Further, as shown in FIG. 4B, the second clamping portion 63 extends from the outer surface on the outer side in the left-right direction of the rear side portion 14 of the side frame 10 to the inner surface in the left-right direction of the rear side portion 44 of the inner frame 40. A groove 63A having substantially the same width as the length is provided, and the rear side portion 14 of the side frame 10 and the rear side portion 44 of the inner frame 40 are sandwiched in the groove 63A.

  By providing such a bracket 60, the rigidity of the side frame 10 can be further improved. Moreover, since the bracket 60 has the 1st clamping part 62 and the 2nd clamping part 63 integrally, compared with the structure which provides separately the bracket which pinches | interposes parts other than a bracket, for example, and a junction part, for example, the number of parts And the assembly work of the bracket 60 can be facilitated.

  In addition, a spring SP is provided between the bracket 60 and the movable member 20 to constantly bias the movable member 20 downward.

  As shown in FIG. 2, one movable member 20 is provided on each of the left and right sides, and is formed to extend in the front-rear direction. As shown in FIG. By being supported by the left and right front links 71 and rear links 72 provided, the side frames 10 can be moved back and forth and tilted. The front link 71 is formed so as to extend inward from the outer side in the left-right direction of the front end portion 13 of the side frame 10, and one end portion is rotatably connected to the outer side in the left-right direction of the front end portion 13 of the side frame 10. The other end is rotatably connected to the front portion of the movable member 20 (see also FIG. 3).

  Specifically, the front link 71 extends substantially rearward along the outer surface of the side frame 10 from the front-side fixed shaft 71A, which is a connecting shaft to the side frame 10, and then bends inward in the left-right direction. The frame 10 extends inward in the left-right direction and then extends substantially rearward, and the rear end thereof is rotatably connected to the movable member 20 via the front-side movable shaft 71B. By connecting one end of the front link 71 to the outer side in the left-right direction of the side frame 10 in this way, the front link 71 is connected to the connecting pipe 52 compared to a structure in which, for example, one end of the front link is connected to the inside of the inner frame. Since interference can be suppressed, the movable member 20 can be operated satisfactorily.

  The rear link 72 is disposed on the rear side of the front link 71 and on the inner side in the left-right direction of the side frame 10, and one end thereof is rotatably connected to the side frame 10 via the rear side fixed shaft 72A. The end portion is rotatably connected to the rear portion of the movable member 20 via the rear side movable shaft 72B. Specifically, the rear link 72 extends substantially downward from the rear-side fixed shaft 72A, then bends inward in the left-right direction, extends to the side surface of the movable member 20, and then extends substantially downward along the side surface. Is formed.

  More specifically, as shown in FIG. 6, the front link 71 and the rear link 72 described above are such that the front movable shaft 71B is located above the front fixed shaft 71A in the reference posture in which the seat back S2 stands at a predetermined angle. The rear movable shaft 72B is disposed below the rear fixed shaft 72A. Here, the predetermined angle is an angle of the seat back S2 with respect to the vertical plane, and is 23 ° in the present embodiment. 6 to 12, for convenience, a fixed shaft whose position with respect to the side frame 10 does not change according to the tilting operation of the seat back S <b> 2 is indicated by a white circle, and a movable shaft that moves with respect to the side frame 10. Is indicated by a dot.

  By arranging the front link 71 and the rear link 72 in this way, the initial stage (FIG. 6) until the seat back S2 tilts to the rearward tilted posture (posture of FIG. 10) tilted most rearward from the reference posture. 8 to 8), the tilting tendency of the movable member 20 is configured to be a first tendency in which the front end portion rises relative to the rear end portion. That is, in the initial stage shown in FIGS. 6 to 8, the angle of the movable member 20 with respect to the horizontal plane is gradually increased.

  As a result, the angle between the seat back S2 and the seat cushion S1 can be set to a suitable angle for maintaining a natural posture when the occupant is weak, so that the occupant can have a comfortable rest on the vehicle seat S. It is possible to obtain.

  Since the configuration in which the movable member 20 is tilted as described above is configured only by the front link 71 and the rear link 72, for example, it is simpler than the structure in which the movable member is tilted using three or more members such as a cam member, a roller, and a link. The movable member 20 can be tilted with a simple structure.

  Further, in the present embodiment, the tilting tendency of the movable member 20 from the first tendency described above until the seat back S2 tilts from the reference attitude (FIG. 6) to the rearward tilting attitude (FIG. 10). The front link 71 and the rear link 72 are arranged so as to switch to the second tendency of lowering relative to the rear end. That is, as shown in FIGS. 8 to 10, the angle of the movable member 20 with respect to the horizontal plane gradually decreases in the later stage until the seat back S <b> 2 tilts from the reference posture to the backward tilt posture. Yes.

  As a result, when the seat back S2 is tilted backward, the movable member 20, the seat back, and S2 can be brought into a substantially flat state, so that the occupant stretches the body on the substantially flat vehicle seat S. It is possible to get a comfortable rest.

  Further, the front-side movable shaft 71B passes through the front-side fixed shaft 71A from the first vertical surface PF1 behind the front-side fixed shaft 71A and through the front-side fixed shaft 71A in the reference posture (FIG. 6). It arrange | positions in the position close | similar to 1st horizontal surface FF1.

  As a result, when the front side movable shaft 71B is rotated forward obliquely upward about the front side fixed shaft 71A, the amount of rise of the front side movable shaft 71B in the first stage (the amount of rise relative to the unit rotation angle). Can be increased. In addition, at the stage after the front side movable shaft 71B becomes closer to the first vertical surface PF1 than the first horizontal plane FF1, the amount of elevation of the front side movable shaft 71B can be suppressed to a small level. Therefore, it is possible to favorably switch the tilting tendency of the movable member 20 from the first tendency to the second tendency.

  The rear movable shaft 72B is closer to the second vertical plane PF2 passing through the rear fixed shaft 72A than the second horizontal surface FF2 passing through the rear fixed shaft 72A in the reference posture (FIG. 6). 2 It is arranged at a position ahead of the vertical plane PF2. Thereby, when the rear side movable shaft 72B is rotated forward and obliquely upward with the rear side fixed shaft 72A as the center, the amount of rise of the rear side movable shaft 72B (the amount of rise relative to the unit rotation angle) in the first stage. Can be kept small. In addition, at the stage after the rear side movable shaft 72B is closer to the second horizontal plane FF2 than to the second vertical surface PF2, the rising amount of the rear side movable shaft 72B can be increased. Therefore, it is possible to favorably switch the tilting tendency of the movable member 20 from the first tendency to the second tendency.

  As shown in FIGS. 2, 3, and 5, the transmission mechanism 30 includes a first transmission link 31, a second transmission link 32, and a third transmission link 33, and includes left and right side frames. One is provided on the inside in the left-right direction. By disposing the transmission mechanism 30 on the inner side in the left-right direction of the side frame 10 in this way, for example, the vehicle seat S can be downsized in the left-right direction compared to a structure in which the transmission mechanism is disposed on the outer side in the left-right direction of the side frame. It is possible.

  A part of the transmission mechanism 30 (a part other than a part on the front end side of the third transmission link 33) is disposed between the rear side part 14 of the side frame 10 and the rear side part 44 of the inner frame 40 in the left-right direction. Has been. Thereby, since it can suppress that an object penetrate | invades from the inner side in the left-right direction with respect to a part of transmission mechanism 30 arrange | positioned between the side frame 10 and the inner frame 40, it can operate the transmission mechanism 30 satisfactorily. It is possible.

  The first transmission link 31 is formed so as to extend obliquely forward and downward from the base end portion (near the tilting shaft F21) of the seat back frame F2, and the rear end portion thereof is connected to the seat back frame F2 with the first connecting shaft A1. The front end is connected to the second transmission link 32 via the second connection shaft A2. In other words, the front end portion of the first transmission link 31 is indirectly connected to the movable member 20 via the second connection shaft A2 and the second transmission link 32 and the third transmission link 33 described later. Accordingly, the tilting operation of the seat back frame F <b> 2 is transmitted to the movable member 20 via the first transmission link 31, the second transmission link 32, and the third transmission link 33.

  More specifically, the first connecting shaft A1 is slightly in front of the tilting shaft F21 (center of tilting) in the reference posture (FIG. 6), more specifically, a straight line connecting the tilting shaft F21 and the second connecting shaft A2. It is arranged at a position shifted upward. The first connecting shaft A1, the second connecting shaft A2, and the tilting shaft F21 are in the middle of the posture (FIG. 12) until the seat back S2 reaches the forward tilting posture (FIG. 13) tilted most forward from the reference posture. It is configured to line up in a straight line.

  As a result, the tilting shaft F21, the first connecting shaft A1, and the second connecting shaft A2 are aligned in the middle of the seat back S2 reaching the forward tilting posture from the reference posture, that is, the tilting shaft F21 and the second connecting shaft. Since the first connecting shaft A1 gets over the straight line connecting the axis A2, the moving direction of the movable member 20 can be switched to the reverse direction.

  The second transmission link 32 is a V-shaped link in a side view, and a base portion 32B that is rotatably connected to the side frame 10 via a rotation shaft 32A, and a first arm that extends obliquely downward and rearward from the base portion 32B. It has a portion 32C and a second arm portion 32D extending obliquely rearward and upward from the base portion 32B. The first transmission link 31 is rotatably connected to the distal end portion of the first arm portion 32C via the second connection shaft A2, and the third connection shaft A3 is connected to the distal end portion of the second arm portion 32D. The 3rd transmission link 33 is connected via the via so that rotation is possible. That is, the distal end portion of the first arm portion 32C located at a position away from the rotation center of the second transmission link 32 is an input portion to which the drive amount from the first transmission link 31 is input, The distal end portion of the second arm portion 32D that is away from the rotation center of the transmission link 32 and is located at a position different from the input portion serves as an output portion for transmitting the drive amount to the third transmission link 33. Yes.

  The third transmission link 33 is a link extending in the front-rear direction. The rear end of the third transmission link 33 is rotatably connected to the second transmission link 32 via the third connection shaft A3, and the front end thereof is the front side described above. It is rotatably connected to the front portion of the movable member 20 via the movable shaft 71B. That is, the connecting shaft of the third transmission link 33 with the movable member 20 and the connecting shaft of the front link 71 with the movable member 20 are configured by the same front-side movable shaft 71B. Thereby, for example, the structure can be simplified as compared with a structure in which the third transmission link and the front link are respectively connected to different portions of the movable member.

  As described above, by configuring the transmission mechanism 30, as shown in FIGS. 6 to 10, when the seat back frame F2 is tilted later from the reference posture, the first transmission link 31 is moved by the seat back frame F2. When pulled rearward and obliquely upward, the second transmission link 32 rotates counterclockwise in the figure, and the third transmission link 33 moves forward. As a result, when the seat back frame F2 is tilted later, a force directed forward from the transmission mechanism 30 to the front portion of the movable member 20 (a force that causes the front link 71) is exerted. The movable member 20 supported by the rear link 72 moves forward, and its tilting tendency is switched from the first tendency to the second tendency by the action of the links 71 and 72.

  Further, as shown in FIGS. 6 and 11 to 13, when the seat back frame F2 is tilted forward from the reference posture, in the initial stage (FIGS. 6, 11, and 12), the seat back frame F2 The first transmission link 31 is pushed forward obliquely downward, the second transmission link 32 rotates clockwise in the figure, and the third transmission link 33 moves rearward. As a result, in the initial stage of the operation of tilting the seat back frame F2 forward from the reference posture, a force acting backward from the transmission mechanism 30 acts on the movable member 20, so that the movable member 20 moves backward while moving the front Due to the action of the link 71 and the rear link 72, the angle with respect to the horizontal plane gradually decreases.

  Then, as shown in FIG. 12, when the seat back frame F2 is tilted 23 ° forward from the reference posture (0 ° with respect to the vertical plane), the first connecting shaft A1, the second connecting shaft A2, and the tilting are performed. The axis F21 is aligned. After the first connecting shaft A1, the second connecting shaft A2, and the tilting shaft F21 are aligned in a straight line (the latter stage of the operation of tilting the seat back frame F2 forward from the reference posture), as shown in FIG. The first transmission link 31 is pulled rearward and obliquely upward by the seat back frame F2, the second transmission link 32 rotates counterclockwise in the drawing, and the third transmission link 33 moves forward.

  As a result, in a later stage of the operation of tilting the seat back frame F2 forward from the reference posture, a forward force is applied from the transmission mechanism 30 to the movable member 20, so that the movable member 20 moves forward, By the action of the link 71 and the rear link 72, the angle with respect to the horizontal plane gradually increases.

  In this way, the moving direction of the movable member 20 is switched from the rear to the front while the seat back S2 is tilted from the reference posture (FIG. 6) to the forward tilt posture (FIG. 13). Compared to the structure in which the movable member continues to move backward until it tilts to the forward leaning posture, the movable member 20 or the rear end portion of the seat cushion S1 provided on the movable member 20 interferes with the seat back S2. Can be suppressed.

As described above, according to the present embodiment, in addition to the effects described above, the following effects can be achieved.
Since the first transmission link 31 is connected to the movable member 20 via the rotatable second transmission link 32, the direction of the input part and the output part of the second transmission link 32 and the distance from the rotation center are adjusted. Thus, the direction of the force applied to the movable member 20 and the amount of movement of the movable member 20 can be adjusted to a suitable direction and amount, so that the movable member 20 or the seat cushion S1 can be further prevented from interfering with the seat back S2. Can do.

[Second Embodiment]
Next, a second embodiment of the present invention will be described in detail with reference to the drawings as appropriate. Since this embodiment is a partial modification of the structure of the first embodiment described above, the same reference numerals are given to substantially the same components as those of the first embodiment, and the description thereof is omitted. I decided to.

  As shown in FIG. 14, in the second embodiment, the movable member 20 integrally has a movable link 34 connected to a front link 71 and a rear link 73. The rear link 73 is formed in a V shape, and a portion corresponding to the corner of the V shape is rotatably supported by the side frame 10 via a rear side fixed shaft 73A.

  In the reference posture, the rear link 73 includes a first arm portion 73C that extends obliquely downward and rearward from the rear-side fixed shaft 73A, and a second arm portion 73D that extends obliquely upward and forward from the rear-side fixed shaft 73A. The distal end portion of the first arm portion 73C is rotatably connected to the movable link 34 via the rear side movable shaft 73B, and the distal end portion of the second arm portion 73D is the first transmission via the fourth connection shaft A4. The link 31 is rotatably connected. In this embodiment, the transmission mechanism is composed of only the first transmission link 31.

  In the reference posture, the rear movable shaft 73B is disposed at a position closer to the second vertical plane PF2 than the second horizontal plane FF2 and at a position rearward of the second vertical plane PF2. Further, the first connecting shaft A1 that is the connecting shaft between the first transmission link 31 and the seat back frame F2 is disposed substantially directly above the tilting shaft F21 in the reference posture.

  Even in such a structure, as shown in FIGS. 14 to 16, the tilting tendency of the movable member 20 until the seatback S2 is tilted from the reference posture (FIG. 14) to the rearward tilt posture (FIG. 16), The first tendency can be switched to the second tendency.

[Third Embodiment]
Next, a third embodiment of the present invention will be described in detail with reference to the drawings as appropriate. In this embodiment, since the structure of the second embodiment is partially changed, the same reference numerals are given to substantially the same components as those of the second embodiment, and the description thereof is omitted. I decided to.

  As shown in FIG. 17, in the third embodiment, in the reference posture, the front-side movable shaft 71B is disposed in front of the first vertical surface PF1, and the rear-side movable shaft 73B is also from the second vertical surface PF2. Is also placed forward. Specifically, in the reference posture, the first arm portion 73C of the rear link 73 extends from the rear-side fixed shaft 73A obliquely forward and downward, and the second arm portion 73D extends substantially directly below. In the reference posture, the first connecting shaft A1 is disposed in front of the tilting shaft F21 and at a position slightly below the tilting shaft F21.

  In such a structure, as shown in FIGS. 17 to 19, the tilting tendency of the movable member 20 before the seat back S2 is tilted from the reference posture (FIG. 17) to the rearward tilt posture (FIG. 19), The first tendency described above is maintained. That is, according to the present invention, the tilting tendency only needs to be the first tendency at least in the initial stage until the seatback tilts from the reference posture to the backward tilting posture. Until it becomes, the inclination tendency may be maintained as the first tendency.

  Although the first to third embodiments of the present invention have been described above, the present invention can be implemented with appropriate modifications as shown in other embodiments below.

  In the said embodiment, although the movable member 20 extended in the front-back direction was illustrated, this invention is not limited to this, A movable member may be what kind of shape.

  In the said embodiment, although the vehicle seat S used by a motor vehicle was illustrated as a vehicle seat, this invention is not limited to this, For example, the sheet | seat used for a ship, an aircraft, etc. It can also be applied to.

DESCRIPTION OF SYMBOLS 10 Side frame 20 Movable member 30 Transmission mechanism 71 Front link 71A Front side fixed shaft 71B Front side movable shaft 72 Rear link 72A Rear side fixed shaft 72B Rear side movable shaft S Vehicle seat S1 Seat cushion S2 Seat back

Claims (5)

A vehicle seat comprising a seat cushion and a seat back tiltable with respect to the seat cushion,
Left and right side frames constituting left and right frames of the seat cushion;
A front link provided on the side frame so as to be rotatable about a front-side fixed shaft;
A rear link disposed rearward of the front link and provided on the side frame so as to be rotatable about a rear-side fixed shaft;
A movable member coupled to the front link so as to be rotatable about a front-side movable shaft, and coupled to the rear link so as to be rotatable about a rear-side movable shaft;
A transmission mechanism coupled to the movable member and the seat back to transmit the tilting motion of the seat back to the movable member;
In a reference posture in which the seatback stands at a predetermined angle, the front-side movable shaft is disposed above the front-side fixed shaft, and the rear-side movable shaft is disposed below the rear-side fixed shaft,
The tilting tendency of the movable member rises relative to the rear end portion at least in the initial stage until the seat back tilts to the rearward tilt posture after tilting most rearward from the reference posture. It is comprised so that it may become the 1st tendency to do, The vehicle seat characterized by the above-mentioned.   The tilting tendency of the movable member until the seatback tilts to the rearward tilting position that is tilted most rearward from the reference posture is such that the front end portion is relatively relative to the rear end portion from the first tendency. The vehicle seat according to claim 1, wherein the front link and the rear link are arranged so as to switch to a second tendency of descending.   The front-side movable shaft is located behind the front-side fixed shaft and closer to the first horizontal plane passing through the front-side fixed shaft than the first vertical surface passing through the front-side fixed shaft in the reference posture. The vehicle seat according to claim 2, wherein the vehicle seat is disposed on the vehicle.   The rear-side movable shaft is arranged at a position closer to a second vertical plane that passes through the rear-side fixed shaft than a second horizontal plane that passes through the rear-side fixed shaft in the reference posture. The vehicle seat according to claim 2 or claim 3.   5. The vehicle seat according to claim 4, wherein the rear-side movable shaft is disposed forward of the second vertical surface in the reference posture.

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