JP2019115432A - Seat reclining device - Google Patents

Abstract

To provide a seat reclining device in which there is less restriction of an operation amount of a seat back, intensity of an internal mechanism is high and excellent in certainty of operations.SOLUTION: A seat reclining device comprises first and second poles which are radially movably supported to a base member and engage to an internal tooth of a ratchet, and engagement thereof is released. The ratchet has first and second pole regulation parts, and in an unlock range in which the first pole regulation part provided outside of the radial direction and a first restriction part of the first pole face in the radial direction, engagement of each pole to the internal tooth of the ratchet is regulated, and the ratchet can rotate always to the base member. In a partial specific range of the unlock range, the second pole regulation part positioned inside of the radial direction and a second restriction part of the second pole face in the radial direction. A center of gravity of the second pole is above a horizontal line passing the rotary axis line.SELECTED DRAWING: Figure 13

Description

  The present invention relates to a seat reclining device provided in a reclining seat capable of adjusting the angle of a seat back.

  As a reclining device provided between the seat cushion side frame of the reclining seat and the seat back side frame, a base plate (lower arm) fixed to the seat cushion side frame and an inner ring with annular inner teeth fixed on the seat back side frame Having a ratchet plate (upper arm) and poles supported movably in the radial direction of the base plate (a plurality of poles are provided at different positions in the circumferential direction), and the external teeth formed on each pole are inside the ratchet plate There is widely used a type in which the relative rotation of the ratchet plate and the base plate is restricted by engaging with the teeth. The pole is biased in the lock direction (radially outward) in which the external teeth are engaged with the internal teeth by biasing means such as a spring, and the pole is released in the unlocking direction (a cam member etc. against this biasing force By moving inward in the radial direction, the lock is released.

  Some seat reclining devices of this type have a mechanism for restricting the movement of the pole in the locking direction when the ratchet plate is within a predetermined angle range with respect to the base plate (Japanese Patent Application Laid-Open No. 2001-147118). As a mechanism for restricting the movement of the pole, the ratchet plate is provided with a pole restricting portion facing inward in the radial direction, and the pole is provided with a projecting restricting portion capable of coming into contact with the pole restricting portion from inside in the radial direction. . When the restricting portion and the pole restricting portion are in a positional relationship in which the restricting portion is arranged in line in the radial direction (opposite), the restricting portion abuts on the pole restricting portion to restrict the amount of movement of the pole outward in the radial direction The teeth do not mesh with the internal teeth of the ratchet plate. That is, rotation of the ratchet plate relative to the base plate is allowed. When the limiting portion and the pole regulating portion do not line up in the radial direction (do not face each other), the pole does not contact the pole regulating portion, and the pole of the pole engages with the internal tooth of the ratchet plate Can be moved. The angular range of the ratchet plate in which the restriction portion and the pole regulation portion do not line up in the radial direction is referred to as a lock range, and the angle range of the ratchet plate in which the restriction portion and the pole regulation portion are aligned in a radial direction is referred to as an unlock range.

  When the ratchet plate rotates in the unlocking range, the restricting portion slides relative to the pole restricting portion. When the limiting portion reaches the circumferential end of the pole restricting portion when the ratchet plate shifts from the unlocking range to the locking range, the biasing force applied to the pole pushes the pole outward in the radial direction. The contact range (contact area) in the circumferential direction of the restricting portion and the pole restricting portion becomes smaller at an angle before the restricting portion reaches the circumferential end of the pole restricting portion. In this state, when the pole is pushed outward in the radial direction by an external force or the like, the pressing force may be concentrated in the narrow contact range of the limiting portion and the pole regulating portion, and an excessive load may be applied.

  The pressing force is dispersed to prevent the deformation of the pole or the like by providing the limiting portion in each of the plurality of poles and increasing the number of the limiting portion and the pole regulating portion abutting in the unlocking range of the ratchet plate. Can. On the other hand, if the number of pole restriction parts and the number of pole restriction parts of the ratchet plate increase, the circumferential space for forming each restriction part and each pole restriction part becomes large. The movable range (the amount of movement of the seat back) in the rotational direction of the combined ratchet plate is reduced.

JP, 2010-42239, A

  An object of the present invention is to provide a seat reclining device having a limited amount of movement of the seat back, high strength of the internal mechanism, and excellent in the certainty of the movement.

  The seat reclining device according to the present invention includes a base member provided on a seat cushion, a ratchet provided on a seat back and having internal teeth and rotatable about a rotation axis with respect to the base member, and a ratchet relative to the base member And a plurality of poles which are supported so as to be movable radially about the rotation axis, and which move to a meshing position for meshing with the internal teeth of the ratchet and a meshing release position for releasing the meshing. The plurality of poles at least include a first pole having a first limit and a second pole having a second limit. The ratchet moves the second pole to the meshing position by abutting the first pole restricting portion which restricts the movement of the first pole to the meshing position by abutting with the first restricting portion, and the second restriction portion. And a second pole regulation unit for regulation. The second restricting portion is disposed radially inward of the first restricting portion, and the second pole restricting portion is disposed radially inward of the first pole restricting portion. In the unlocking range where the first pole restricting portion and the first restricting portion face in the radial direction and the ratchet can always rotate with respect to the base member, the second pole restricting portion and the second restricting portion The parts face in the radial direction. The center of gravity of the second pole is located above a horizontal line passing through the rotation axis of the ratchet.

  According to this configuration, in a specific range which is a part of the unlocking range of the ratchet, it is possible to receive radial force by the second limiting portion of the second pole in addition to the first limiting portion of the first pole And load resistance can be improved. In addition, since the second restricting portion and the second pole restricting portion are located radially inward of the first restricting portion and the first pole restricting portion, the second restricting portion and the first pole restricting portion face in the radial direction. By rotating the ratchet to the position, the second pole can be moved to the meshing position, and the rotatable range of the ratchet can be expanded. Furthermore, since the second pole is located at the upper side of the center of gravity of the second pole relative to the horizontal line passing through the rotation axis which is the rotation center of the ratchet relative to the base member, the second pole receives the movement force toward the disengaging position by gravity. The second pole is unlikely to stay in a position where the second limiting portion and the second pole restricting portion abut in the rotational direction to prevent the rotation of the ratchet, and a reliable operation can be realized.

  The base member has a second pole guiding portion for guiding the second pole movably in the radial direction while restricting the movement of the second pole in the rotational direction about the rotation axis, and the second pole guiding portion It is preferable that it is a linear groove-like portion that extends downward as it approaches the rotation axis in the radial direction.

  As described above, according to the present invention, it is possible to obtain a seat reclining device having a limited amount of movement of the seat back, a high strength of the internal mechanism, and an excellent operation reliability.

It is a side view of a reclining seat. It is an exploded perspective view of a seat reclining device. It is a side view of a seat reclining device in the state where the 1st pole and the 2nd pole are in a meshing position in the locking range of a ratchet plate. It is a side view of a seat reclining device in the state where the 1st pole and the 2nd pole are in a meshing release position in the locking range of a ratchet plate. It is a side view of the seat reclining device in the state where the holding projection of the first pole is in contact with the first holding projection in the unlocking range of the ratchet plate. It is a side view of the seat reclining device in the state where the auxiliary retention projection of the 2nd pole opposed to the 2nd retention projection in the unlocking range of a ratchet plate. It is a side view of a seat reclining device just before a ratchet plate changes from an unlocking range to a locking range. It is sectional drawing which follows the VIII-VIII line of FIG. It is a side view of a ratchet plate. It is a side view of a base plate. It is a side view of the 1st pole. It is a side view of the 2nd pole. It is a side view which shows the state which supported the 1st pole and the 2nd pole by the base plate.

  Hereinafter, embodiments to which the present invention is applied will be described with reference to the drawings. In the following description, the left and right direction corresponds to the arrow direction of "left" and "right" described in FIGS. 2 and 8 and in the vehicle reclining seat 10 and the seat reclining device 15 of the embodiment. The right side is the outside of the vehicle, and the left side is the inside of the vehicle. Further, the inner peripheral side means the radial center (inner diameter side) of the seat reclining device 15, and the outer peripheral side means the opposite side (outer diameter side) to the radial center of the seat reclining device 15. The arrow directions of "upper" and "lower" described in FIGS. 3 to 7, 10 and 13 correspond to the vertical direction in a state where the reclining seat 10 is installed on the vehicle floor as shown in FIG. doing. That is, when the vehicle is in a flat place without inclination, the “down” direction in FIGS. 3 to 7, 10, and 13 is the vertical direction on which gravity acts.

  A reclining seat 10, which is a vehicle seat shown in FIG. 1, constitutes a seat on the right side in the traveling direction of the vehicle, and includes a seat cushion 11 supported on an in-vehicle floor surface of the vehicle via a seat rail. And a seat back 12 which can be tilted with respect to the rear of the seat cushion 11. Inside the reclining seat 10, there is provided a forward-biasing spring (not shown) that biases the seat cushion 11 to rotate forward with respect to the seat back 12.

  A pair of left and right seat cushion side frames (not shown) is provided inside the seat cushion 11, and a rear frame (not shown) projecting upward is provided in a fixed state at the rear of the seat cushion 11. A pair of left and right seat back side frames (not shown) is provided inside the seat back 12. The left and right seat back side frames are positioned between the left and right rear frames, and the left and right seat back side frames and the left and right rear frames face each other in the left and right direction (the vehicle width direction).

  On the left side (inside of the vehicle) of the reclining seat 10, the rear frame and the seatback side frame are rotatably connected via a rotary connection shaft (not shown). On the other hand, on the right side (outside the vehicle) of the reclining seat 10 shown in FIG. 1, a seat reclining device 15 is provided between the rear frame and the seat back side frame for connecting both rotatably around the horizontal axis. ing. The seat back 12 is rotatable relative to the seat cushion 11 about the rotary connection shaft and the seat reclining device 15.

  Specifically, the seat back 12 can be tilted between the forward tilting position 12A and the backward tilting position 12B shown in FIG. Although the configuration of the seat reclining device 15 will be described later, a locking range in which the angle of the seat back 12 can be held by the seat reclining device 15 being in a locked state from the first step locking position 12C shown in FIG. It is. In the lock range, the lock state is temporarily released by performing the unlocking operation on the seat reclining device 15, and the angle adjustment of the seat back 12 can be performed. The seat reclining device 15 is in an unlocking range where the seat reclining device 15 does not become locked from the forward lean position 12A to immediately before the first stage lock position 12C.

  Subsequently, the detailed structure of the seat reclining device 15 will be described with reference to FIG. As shown in FIG. 2, the seat reclining device 15 includes, as main components, a base plate (base member) 20, first and second poles 30 and 31, a rotating cam 40, a release plate 50, and a ratchet plate (ratchet) 60. A lock spring 70 and a pressure ring 80 are provided.

  The base plate 20 which is a metal disk member is a press-formed product, and a circular shaft insertion hole 21 is formed as a through hole at the center of the base plate 20 as shown in FIG. 2, FIG. 10 and FIG. . A circular large diameter annular flange 22 protrudes from the peripheral edge of the left side surface of the base plate 20, and a storage space is formed inside the large diameter annular flange 22. On the left side surface of the base plate 20, three groove forming projections 23 are provided protruding at equal angular intervals (120 °) in the circumferential direction about the shaft insertion hole 21.

  Each groove forming protrusion 23 is substantially fan-shaped to increase the circumferential width from the inner peripheral side to the outer peripheral side of the base plate 20, and the outer peripheral surface of each groove forming protrusion 23 and the large diameter annular flange 22 An arc-shaped gap is formed between (see FIGS. 2 and 10). Guide planes 23 a and 23 b are provided on both sides of each groove forming protrusion 23. The guide planes 23a and 23b of adjacent groove forming projections 23 are substantially parallel to each other, and a guide groove 24 is formed therebetween. That is, three guide grooves 24 are formed at different positions in the circumferential direction on the base plate 20, and these are distinguished as a first pole guide groove 24A, a second pole guide groove 24B and a second pole guide groove 24C. (Refer FIG. 2, FIG. 10). In each groove forming projection 23, a spring hooking recess 25 is formed in the middle of the guide plane 23b.

  The seat reclining device 15 is provided with one first pole 30 and two second poles 31 each of which is a press-formed product of a metal plate. The poles 31 are disposed one by one. As shown in FIGS. 11 and 12, the first pole 30 and the second pole 31 have holding protrusions (first limiting portion) 32 and auxiliary holding protrusions (second limiting portion) 33 which are different in shape and arrangement from each other. Other than that, it has a common configuration. Parts in common with the first pole 30 and the second pole 31 are denoted by the same reference numerals.

  As shown in FIGS. 11 and 12, each of the first pole 30 and the second pole 31 has surfaces which can slide along the guide planes 23a and 23b on both sides in the circumferential direction. A holding projection 32 and a cam follower 34 are provided on the left side surface of the first pole 30, and an auxiliary holding projection 33 and a cam follower 34 are provided on the left side surface of the second pole 31. External teeth 35 are formed on the arc-shaped outer peripheral surfaces of the first pole 30 and the second pole 31. At the inner peripheral portions of the first pole 30 and the second pole 31, a suppressed portion 36 and a pressed portion 37 that protrude radially inward are formed.

  As shown in FIGS. 11 and 13, the holding projection 32 of the first pole 30 is a projection whose longitudinal direction is directed in the circumferential direction (rotational direction of the ratchet plate 60 with respect to the base plate 20). And an inner side surface 32b facing inward in the radial direction, and a connecting surface 32c and a connecting surface 32d positioned on both sides in the circumferential direction. The outer side surface 32a is a gently curved convex arc surface, and the inner side surface 32b is a gently curved concave arc surface. The holding projection 32 has a substantially symmetrical shape with respect to a center line C1 (FIG. 11) extending in the radial direction of the base plate 20 through the circumferential center. Therefore, the connection surface 32c and the connection surface 32d also have substantially symmetrical shapes with respect to the center line C1.

  As shown in FIGS. 12 and 13, the auxiliary holding projection 33 of the second pole 31 is a projection whose longitudinal direction is directed in the circumferential direction (rotational direction of the ratchet plate 60 with respect to the base plate 20). 33a, an inner side surface 33b facing inward in the radial direction, and a connecting surface 33c and a connecting surface 33d positioned on both sides in the circumferential direction. The outer side surface 33a is a convexly curved arc surface gently curved, and the inner side surface 33b is a concavely curved arc surface gently curved. The auxiliary holding projections 33 are asymmetrically shaped with respect to a center line C2 (FIG. 12) which extends in the radial direction of the base plate 20 through the circumferential center. Specifically, the connection surface 33 c has substantially the same shape as the connection surface 32 c of the holding projection 32, and there is an angular portion from the outer surface 33 a to the connection surface 33 c. On the other hand, the connection surface 33 d is a convex arc-shaped surface projecting in the circumferential direction, and is smoothly connected to both the outer surface 33 a and the inner surface 33 b while curving.

  As shown in FIGS. 11 and 12, the auxiliary holding projection 33 of the second pole 31 is located radially inward of the holding projection 32 of the first pole 30. More specifically, if a virtual tip circle connecting the tips of the external teeth 35 is set, the distance between the tip circle and the auxiliary holding projection 33 is greater than the distance from the tip circle to the outer surface 32 a of the holding projection 32. The distance to the outer side surface 33a is larger.

  The center of gravity (center of mass) GP1 of the first pole 30 in a side view is shown in FIGS. 11 and 13, and the center of gravity (center of mass) GP2 of the second pole 31 in a side view is shown in FIGS.

  The first pole 30 and the second pole 31 are disposed in the guide grooves 24 in the manner shown in FIGS. 3 to 7 and 13. Although only one of the two second poles 31 is illustrated in FIGS. 3 to 7, the guide groove 24 is the same as the second pole 31 illustrated in the other second pole 31 whose illustration is omitted. It is disposed inside and operates similarly (see FIG. 13). The first pole 30 and the second pole 31 are supported in surface contact with the bottom surface (left side surface) of each guide groove 24, and the guide plane 23 a of the groove forming protrusion 23 in the corresponding guide groove 24. , 23b in the radial direction of the base plate 20.

  The first pole 30 and the second pole 31 are engaged with the radially outer meshing position (FIGS. 3 and 13) which is separated from the shaft insertion hole 21 of the base plate 20 by the rotation cam 40 and the release plate 50 described later. Move radially between the radially inward disengaging position (FIG. 4) approaching. The smooth sliding of each pole 30, 31 in the radial direction of the base plate 20 is enabled between the first pole 30 and the second pole 31 and the guide planes 23a, 23b located on both sides, and each pole The clearance is secured to the extent that the wheels 30 and 31 are not greatly distorted.

  The rotating cam 40 is a press-formed product of a metal plate, and has substantially the same thickness as that of the respective poles 30 and 31. As shown in FIGS. 2 to 7, a non-circular central non-circular hole 41 is formed as a through hole at the central portion of the rotating cam 40. Three suppressing portions 42 and three pressing portions 43 are provided on the outer peripheral portion of the rotating cam 40 at substantially equal angular intervals in the circumferential direction. The rotation cam 40 is further provided with three detent protrusions 44 at equal angular intervals in the circumferential direction. As shown in FIG. 2, the locking projection 44 protrudes leftward. In the center non-circular hole 41 of the rotating cam 40, three spring hooking recesses 45 are formed at substantially equal angular intervals in the circumferential direction. The rotating cam 40 is disposed at the central portion of the storage space of the base plate 20, and the first pole 30 and the second pole 31 are located radially outward of the rotating cam 40 (see FIGS. 3 to 7).

  The release plate 50 is a press-formed product of a metal plate, and three cam holes 52 are penetratingly formed around the central opening 51 at substantially equal angular intervals in the circumferential direction. As shown in FIGS. 3 to 7, the central opening 51 is larger than the central non-circular hole 41 of the rotating cam 40. Each cam hole 52 has a lock permitting portion 52a located on the radially outer side far from the central opening 51, and a lock releasing portion 52b located radially inwards at a short distance from the central opening 51. . In the release plate 50, three detent holes 53 are further formed at equal angular intervals in the circumferential direction.

  The release plate 50 is coupled to the rotating cam 40 by fitting the three locking protrusions 44 into the three locking holes 53. The relative rotation of the rotating cam 40 and the release plate 50 is restricted by the engagement of the locking projections 44 and the locking holes 53, and the rotation cam 40 and the release plate 50 rotate integrally. Further, the cam followers 34 provided on the first pole 30 and the second pole 31 are respectively inserted into the three cam holes 52 of the release plate 50. The movement of the first pole 30 and the second pole 31 radially inward of the position shown in FIG. 4 is restricted by the engagement of the cam follower 34 and the unlocking portion 52b.

  A ratchet plate 60, which is a metal disk member, is a press-formed product, and a circular small-diameter annular flange 61 protrudes from the peripheral edge of the right side surface thereof, and a storage space is formed inside the small-diameter annular flange 61. . As shown in FIGS. 2 and 9, a shaft insertion hole 62 having a circular cross section is formed as a through hole at the center of the ratchet plate 60. As shown in FIG. A portion of the ratchet plate 60 closest to the shaft insertion hole 62 on the inner peripheral side is a disc-like base portion 63. An intermediate annular portion 64 is formed at a radial position between the base portion 63 and the small diameter annular flange 61. As can be seen from FIG. 8, the intermediate annular portion 64 is positioned one step left of the small diameter annular flange 61 and smaller in diameter than the small diameter annular flange 61, and the base portion 63 is positioned one stage left of the intermediate annular portion 64. The diameter is smaller than that of the portion 64.

  As shown in FIGS. 8 and 9, an inner tooth 65 is formed on the inner peripheral surface of the small diameter annular flange 61 of the ratchet plate 60. The first holding projection (first pole restricting portion) 66, the second holding projection (second pole restricting portion) 67, and the third holding projection (first pole restricting portion) 66 are provided on the inner circumferential surface of the intermediate annular portion 64 at different positions in the circumferential direction. A holding projection (second pole restricting portion) 68 is formed. Each of the first holding projection 66, the second holding projection 67, and the third holding projection 68 has a shape projecting radially inward from the intermediate annular portion 64.

  As shown in FIG. 9, the first holding projection 66 is formed in a range from the step surface 66 a located at one end in the circumferential direction to the second holding projection 67 located at the other end in the circumferential direction. It has a holding surface 66 b which is a surface on the inner peripheral side connecting the surface 66 a and the second holding projection 67. The holding surface 66 b is a circular arc surface centering on the center point of the ratchet plate 60.

  As shown in FIG. 9, the second holding projection 67 has a circumferential length shorter than that of the first holding projection 66, and has a stepped surface 67a and an upright wall 67b at one end and the other end in the circumferential direction. The step surface 67 a is connected to the holding surface 66 b of the first holding projection 66. The step surface 67 a and the upright wall surface 67 b have an inclination that reduces the distance between the step surface 67 a and the step wall 67 b from the radially outer side to the inner side in the radial direction of the ratchet plate 60. Has a large inclination with respect to the radial direction. On the inner peripheral side of the second holding projection 67, a holding surface 67c connecting the stepped surface 67a and the upright wall surface 67b is formed. The holding surface 67 c is disposed radially inward of the holding surface 66 b of the first holding projection 66 by the radially inward projecting shape of the step surface 67 a and the upright wall surface 67 b with respect to the intermediate annular portion 64. The holding surface 67 c is a concave arc surface centered on the center point of the ratchet plate 60.

  As shown in FIG. 9, the third holding projection 68 has a shape substantially similar to that of the second holding projection 67, and has a stepped surface 68a and an upright wall surface 68b at one end and the other end in the circumferential direction. And a holding surface 68c. The stepped surface 68 a and the holding surface 68 c have a shape common to the stepped surface 67 a and the holding surface 67 c of the second holding projection 67. The inclination of the standing wall 68b with respect to the radial direction of the ratchet plate 60 is the same as that of the standing wall 67b, except that the standing wall 68b is formed longer in the radial direction outside than the standing wall 67b. The holding surface 68 c is disposed radially inward of the holding surface 66 b of the first holding projection 66 by the radially inward projecting shape of the step surface 68 a and the upright wall surface 68 b with respect to the intermediate annular portion 64.

  The stepped surface 66a of the first holding projection 66, the stepped surface 67a of the second holding projection 67, and the stepped surface 68a of the third holding projection 68 are substantially equiangular in the circumferential direction (about the center point of the ratchet plate 60) Approximately 120 °). The first holding projection 66 is formed continuously over a long range in the circumferential direction from the step surface 66a to the step surface 67a.

  The ratchet plate 60 is placed on the left side surface of the base plate 20 in a state where the small diameter annular flange 61 is inserted into the gap between the inner peripheral surface of the large diameter annular flange 22 and the outer peripheral surface of the groove forming protrusion 23 (see FIG. 8). In this state, the external teeth 35 provided on each of the first pole 30 and the second pole 31 and the internal teeth 65 of the ratchet plate 60 radially face each other.

  When the outer teeth 35 and the inner teeth 65 do not mesh (the respective poles 30, 31 are in the mesh release position), relative rotation of the ratchet plate 60 with respect to the base plate 20 is enabled. The sliding contact of the outer peripheral surface of the small diameter annular flange 61 with the inner peripheral surface of the large diameter annular flange 22 causes the ratchet plate 60 to extend in the left-right direction (vehicle width direction) relative to the base plate 20 (FIGS. 10 and 13). Can be rotated around). The rotation axis RX is an imaginary axis passing through the center of the inner circumferential surface of the large diameter annular flange 22 and the outer circumferential surface of the small diameter annular flange 61 each having a circular shape.

  When the outer teeth 35 and the inner teeth 65 mesh with each other (the respective poles 30, 31 are in the meshing position), the rotation of the ratchet plate 60 with respect to the first pole 30 and the second pole 31 is restricted. The first pole 30 and the second pole 31 are supported with respect to the base plate 20 in a state in which the rotation around the rotation axis RX is restricted (movable only in the radial direction). Therefore, the relative rotation of the ratchet plate 60 with respect to the base plate 20 is restricted by meshing the outer teeth 35 and the inner teeth 65.

  Three lock springs 70 (FIG. 2) are disposed in the space between the ratchet plate 60 and the base plate 20. Each lock spring 70 is made of a curved metal wire, and one end is bent rightward to form a first locking portion 71, and the other end is bent rightward to form a second locking portion 72. As shown in FIGS. 3 to 7, each lock spring 70 locks the first locking portion 71 to the spring hooking recess 45 of the rotating cam 40, and the second locking portion 72 to the spring hooking recess 25 of the base plate 20. It locks and is attached. When the lock springs 70 are attached to the base plate 20 and the rotary cam 40 in this manner, the lock springs 70 are elastically deformed to generate a biasing force for rotating the rotary cam 40 in one direction. The biasing force is a force for rotating the rotating cam 40 in the counterclockwise direction in FIGS. 3 to 7, and the same biasing force also acts on the release plate 50 integrated with the rotating cam 40 in the rotational direction.

  As shown in FIG. 8, the pressing ring 80, which is a metal annular member, is fitted to the outer peripheral surface of the large diameter annular flange 22 of the base plate 20 and the left side surface of the small diameter annular flange 61 of the ratchet plate 60. In form and fixed relative to the base plate 20. In this state, the ratchet plate 60 is sandwiched between the base plate 20 and the pressing ring 80, and the ratchet plate 60 rotates along the inner circumferential surface of the large diameter annular flange 22 without falling off from the base plate 20 and the pressing ring 80. Relative rotation is possible around the axis RX.

  The base plate 20 is fixed to a rear frame (not shown) constituting the seat cushion 11, and the ratchet plate 60 is fixed to a seat back side frame (not shown) constituting the seat back 12. Accordingly, the base plate 20 does not rotate about the rotational axis RX (FIGS. 10 and 13), and is always at a constant position in the rotational direction. On the other hand, the ratchet plate 60 rotates about the rotation axis RX (FIGS. 10 and 13) as the seat back 12 tilts.

  In the base plate 20 fixed to the rear frame, as shown in FIG. 10, three guide grooves 24 radially extend from the radial center (rotational axis RX). More specifically, the first pole guiding groove 24A linearly extends downward from the radial center. The second pole guide groove 24B and the second pole guide groove 24C extend linearly and obliquely upward from the radial center. The first pole 30 is disposed in the first pole guide groove 24A extending downward, and the second pole 31 is disposed in the second pole guide grooves 24B and 24C extending obliquely upward.

  A horizontal line LH extending horizontally through the rotation axis RX and a vertical line LV extending vertically through the rotation axis RX are shown in FIGS. 10 and 13. As shown in FIG. 10, the first pole guiding groove 24A is a groove located below the horizontal line LH and extending along the vertical line LV. The first pole 30, including the center of gravity GP1, is located below the horizontal line LH, and is guided to be movable in the vertical direction.

  As shown in FIG. 10, the second pole guide grooves 24B and 24C are grooves that are mostly located above the horizontal line LH and extend obliquely at a predetermined angle with respect to the vertical line LV. Therefore, the two second poles 31 are respectively guided so as to be inclined in the horizontal direction and the vertical direction, with most of them located above the horizontal line LH. The second pole guiding groove 24B and the second pole guiding groove 24C are arranged substantially symmetrically with respect to the vertical line LV, and correspondingly, the two second poles 31 operate approximately symmetrical with respect to the vertical line LV.

  More specifically, as shown in FIG. 13, the two second poles 31 are each partially located below the horizontal line LH, but the center of gravity GP2 is always located above the horizontal line LH. With this arrangement, the force of gravity acting on each second pole 31 moves the second pole 31 to the rotation axis RX side (engagement release position) along the second pole guiding grooves 24B and 24C (F1, F2 ( Act as Figure 13).

  The side (right side) of the seat reclining device 15 is provided with an operation lever 90 (FIG. 1) which can be operated to rotate. A shaft 91 (FIG. 1) is inserted at the radial center of the seat reclining device 15. The axis of the shaft 91 substantially coincides with the rotation axis RX which is the rotation center of the ratchet plate 60. When the operation lever 90 is rotated, the shaft 91 is rotated about the axis. The shaft 91 penetrates the shaft insertion hole 21, the center non-circular hole 41, the central opening 51, and the shaft insertion hole 62, and among them, the center non-circular hole 41 is fitted in a state of being restricted in relative rotation. ing. Therefore, when the shaft 91 rotates, the rotating cam 40 and the release plate 50 both rotate.

  The operation of the seat reclining device 15 will be described mainly with reference to FIGS. 3 to 7. In FIGS. 3 to 7, the poles 30 and 31 and the rotating cam 40 positioned on the back side of the drawing with respect to the ratchet plate 60 are indicated by solid lines. In addition, the release plate 50 is virtually illustrated by a dashed dotted line. In FIGS. 3 to 7, only one of the two second poles 31 is illustrated, and the second pole 31 not illustrated performs the same operation as the illustrated second pole 31.

  The rotation range of the ratchet plate 60 (seatback 12) in the seat reclining device 15 is a lock range in which the first holding projection 66 does not radially face the holding projection 32 of the first pole 30, and the first holding projection 66 Are roughly divided into unlocking ranges radially opposed to the holding projections 32 of the first pole 30.

  When no operation force is applied to the rotary cam 40 and the release plate 50 in the locking range of the ratchet plate 60 (seat back 12), the seat reclining device 15 is in the locked state shown in FIG. The position of the rotating cam 40 and the release plate 50 at this time is called a lock position. In the locked state, the rotating cam 40 and the release plate 50 are held in the locked position by the biasing force of the lock spring 70 (which is biased in the counterclockwise direction in the drawing). The pressed portions 37 of the first pole 30 and the second pole 31 are pressed radially outward (the meshing position side) by the pressing portion 43 of the rotating cam 40 in the lock position.

  In the locking range of the ratchet plate 60, the holding projection 32 provided on the first pole 30 does not face the first holding projection 66 in the radial direction (the circumferential position is different). It can move to the meshing position without being restricted by the holding projection 66. Also, although the auxiliary holding projection 33 provided on the second pole 31 is at a position radially opposed to the first holding projection 66, the auxiliary holding projection 33 is provided radially inward of the holding projection 32. Therefore, the second pole 31 can move to the meshing position without being restricted by the first holding projection 66. Thus, the first pole 30 and the second pole 31 pressed radially outward by the rotating cam 40 are held at the meshing position where the external teeth 35 are meshed with the internal teeth 65 of the ratchet plate 60, and the base plate 20 and the ratchet plate 60 Relative rotation is restricted. That is, tilting of the seat back 12 with respect to the seat cushion 11 is restricted. At the meshing position of the first pole 30, the outer side surface 32 a of the holding projection 32 is located radially outward of the holding surface 66 b of the first holding projection 66. At the meshing position of the two second poles 31, the outer side surface 33a of each auxiliary holding projection 33 is positioned radially outward of the holding surface 67c of the second holding projection 67 and the holding surface 68c of the third holding projection 68. Do.

  In the locked position of the release plate 50, the cam followers 34 of the first pole 30 and the second pole 31 are located at the lock permitting portion 52a of the cam hole 52, and the release plate 50 is involved in setting the position of the pole 30. Not. In addition, when the first pole 30 and the second pole 31 move to the lock position, and in the holding state at the lock position, normally, the suppressing portion 42 of the rotating cam 40 does not abut the controlled portion 36, and the first Only when the pole 30 or the second pole 31 inclines, the suppressing portion 42 and the suppressed portion 36 abut.

  In the locking range of the ratchet plate 60 (seat back 12), when the operating lever 90 is rotated from the solid line position in FIG. 1 to the two-dot chain line position against the biasing force of each lock spring 70, the shaft 91 (FIG. 1) is The rotating cam 40 and the release plate 50 rotate clockwise (unlocking direction) in FIG. When the release plate 50 rotates in the unlock direction from the lock position, the cam plate 34 formed on the release plate 50 by the cam followers 34 of the first pole 30 and the second pole 31 moves from the lock permitting portion 52a to the unlocking portion 52b. Change the position. Then, the cam follower 34 is pressed radially inward of the base plate 20 by the inner surface of the cam hole 52, and the first pole 30 and the second pole 31 move radially inward in the guide groove 24 respectively. At this time, the rotary cam 40 moves the pressing portion 43 in the direction opposite to the pressing direction to the first pole 30 and the second pole 31, so the radial direction inward of the first pole 30 and the second pole 31 by the release plate 50 Not disturb the movement of

  When the rotating cam 40 and the release plate 50 rotate to the unlock position shown in FIG. 4, the first pole 30 and the second pole 31 completely disengage the outer teeth 35 from the inner teeth 65 of the ratchet plate 60. Reaches the disengagement position. By releasing the engagement between the external teeth 35 and the internal teeth 65, relative rotation of the base plate 20 and the ratchet plate 60 becomes possible. In other words, the seat back 12 can be tilted with respect to the seat cushion 11 in an unlocked state. In the unlocked state, the suppressing portion 42 of the rotating cam 40 is accommodated in the recess between the controlled portion 36 and the pressed portion 37 in each of the first pole 30 and the second pole 31, and the adjacent pole 30, 31 is interposed between The pressing portion 43 of the rotary cam 40 is accommodated in the space of the rotary cam 40, and the first pole 30 and the second pole 31 can be moved to the mesh release position without being blocked by the rotary cam 40.

  When the operation on the operation lever 90 is released in the unlocked state shown in FIG. 4, the rotary cam 40 and the release plate 50 move counterclockwise from the unlocked position to the locked position (FIG. 3) by the biasing force of each lock spring 70. Rotate. When the rotary cam 40 is rotated in the locking direction, the first pole 30 and the second pole 31 are appropriately pressed by the pressing portion 37 by the pressing portion 43 and move to the outer peripheral side in the guide groove 24 to engage with the meshing position (FIG. 3). Reaching).

  In the unlocking range of the ratchet plate 60 (seat back 12), as shown in FIG. 5, the holding projection 32 formed on the first pole 30 and the first holding projection 66 formed on the ratchet plate 60 are radially opposed Because of the positional relationship, the outer side surface 32 a of the holding projection 32 is engaged with the holding surface 66 b of the first holding projection 66 to restrict the movement of the first pole 30 radially outward. That is, as in the case where the cam follower 34 is pulled inward in the radial direction by the cam hole 52 as shown in FIG. 4, the contact between the holding projection 32 and the first holding projection 66 makes the first pole 30 have external teeth 35. It is held at the meshing release position where it does not mesh with the internal teeth 65. By restricting the movement of the first pole 30, the rotation of the rotating cam 40 in the locking direction (the direction in which the first pole 30 is pressed radially outward) is restricted, and the rotating cam 40 does not rotate in the locking direction The second pole 31 also stops at the position shown in FIG. 5 (a meshing release position in which the external teeth 35 do not mesh with the internal teeth 65). At this time, the cam followers 34 of the first pole 30 and the second pole 31 are not in contact with the inner surface of the corresponding cam hole 52, and the release plate 50 is used to set the positions of the first pole 30 and the second pole 31. Is not involved.

  FIG. 5 shows the state where the ratchet plate 60 is positioned at a position away from the lock range by a predetermined distance or more in the unlock range. At this time, the auxiliary holding projections 33 of the second pole 31 shown in FIG. 5 and the second pole 31 not shown in FIG. 5 are the second holding projection 67 and the third holding projection of the ratchet plate 60. The auxiliary holding projections 33 are not in contact with the second holding projection 67 and the third holding projection 68, because they do not face each other in the radial direction with respect to 68 (the positions are made different in the circumferential direction) .

  In the unlocking range shown in FIG. 5, the external teeth 35 of the first pole 30 and the second pole 31 are not meshed with the internal teeth 65 of the ratchet plate 60, and the ratchet plate 60 can always rotate with respect to the base plate 20. Become. That is, tilting of the seat back 12 is possible without continuing the unlocking operation. The area from the forward inclined position 12A of the seat back 12 shown in FIG. 1 to the position just before the first stage lock position 12C is in the unlock range, and the holding projection 32 of the first pole 30 and the first holding projection 66 of the ratchet plate 60 The circumferential length and the relative position are set so as to maintain the radial opposing relationship throughout the lock range. When the seat back 12 is raised to the first stage lock position 12C, the unlocking holding state (the facing state of the holding projection 32 and the first holding projection 66) is released, and the ratchet plate 60 is switched from the unlocking range to the locking range.

  In addition to the holding projection 32 of the first pole 30 radially facing the first holding projection 66, the unlocking range of the ratchet plate 60 in the specific range close to the switching position with the locking range is two. The auxiliary holding projections 33 of the second pole 31 respectively face the second holding projections 67 and the third holding projections 68 in the radial direction.

  FIG. 6 shows the ratchet plate 60 in a specific range in the unlock range. In the state of FIG. 6, the step surface 66a of the first holding projection 66 reaches near the holding projection 32 of the first pole 30, but following the state of FIG. 5, the entire holding projection 32 has the outer side surface 32a. It is in contact with the holding surface 66 b of the first holding projection 66. At this time, the auxiliary holding projection 33 of the second pole 31 and the second holding projection 67 of the ratchet plate 60 are radially opposed, but the outer surface 33 a of the auxiliary holding projection 33 and the holding surface of the second holding projection 67 There is a slight clearance between it and 67c, and the auxiliary holding projection 33 and the second holding projection 67 are not in contact with each other. The auxiliary holding projection 33 and the third holding projection 68 of the second pole 31 which are omitted in FIG. 6 have the same positional relationship, and while the outer side surface 33a and the holding surface 68c have a clearance between each other Without contact) in the radial direction.

  FIG. 7 shows the ratchet plate up to the position immediately before the first holding projection 66 releases the contact with the holding projection 32 of the first pole 30 (immediately before switching from the unlocking range to the locking range) in the specific range. 60 is rotated. The step surface 66a of the first holding projection 66 reaches near the connection surface 32c of the holding projection 32, and the area in which the outer surface 32a of the holding projection 32 and the holding surface 66b of the first holding projection 66 abut decreases. ing. With regard to the auxiliary holding projection 33 and the second holding projection 67, the range in which the step surface 67a of the second holding projection 67 reaches near the connection surface 33c of the auxiliary holding projection 33 and is opposed in the radial direction is from the state of FIG. Although it is smaller, the outer surface 33a and the holding surface 67c are in a radially opposed relationship also in the state of FIG. 7 following the state of FIG. The auxiliary holding projection 33 and the third holding projection 68 of the second pole 31 which are omitted in FIG. 7 have the same positional relationship, and while the outer side surface 33a and the holding surface 68c have a clearance between each other The state of facing in the radial direction is maintained.

  In the specific range of the ratchet plate 60 shown in FIGS. 6 and 7, the cam followers 34 of the first pole 30 and the second pole 31 do not contact the inner surface of the corresponding cam hole 52, and the release plate 50 It is not involved in the positioning of the pole 30 and the second pole 31.

  In the unlocking range shown in FIG. 5 to FIG. 7, the holding projection 32 of the first pole 30 abuts on the first holding projection 66 to maintain the unlocked state in which the external teeth 35 and the internal teeth 65 are not engaged. In this unlocking range, a load may be applied to move the poles 30, 31 radially outward, such as a force for rotating the rotating cam 40 in the locking direction. In the state where the entire outer side surface 32a of the holding projection 32 abuts on the holding surface 66b of the first holding projection 66 as shown in FIG. 5 and FIG. Even when a large load is applied to press the radial direction 30 outward, deformation of the first pole 30 including the holding projection 32 and the ratchet plate 60 including the first holding projection 66 is unlikely to occur. On the other hand, when the contact area between the holding projection 32 and the first holding projection 66 is reduced as shown in FIG. 7 showing the state immediately before switching from the unlocking range to the locking range, a large load pressing the first pole 30 radially outward. As a result, deformation may occur around the holding projection 32 and around the first holding projection 66. As shown in FIG. 7, in this state, the auxiliary holding projection 33 of the second pole 31 radially faces the second holding projection 67 (and the third holding projection 68), and therefore, it is directed radially outward. When the first pole 30 or the first holding projection 66 is deformed due to a large load, the auxiliary holding projection 33 of the second pole 31 which also receives the load in the radially outward direction is the second holding projection 67 or the third holding projection 67. The movement of the second pole 31 outward in the radial direction can be restricted (that is, the unlocked state can be maintained) by abutting on the holding projection 68.

  The second holding projection 67 and the third holding projection 68 of the ratchet plate 60 are in the radial direction with the auxiliary holding projection 33 only in a specific range (FIGS. 6 and 7) close to the switching with the locking range in the unlocking range. The length in the circumferential direction is set shorter than the first holding projection 66 so as to face each other. Therefore, the auxiliary holding projection 33 of the second pole 31 has a diameter larger than the positions of the holding surface 67c of the second holding projection 67 and the holding surface 68c of the third holding projection 68 in the portion excluding the specific range in the unlocking range. There is a room for advancing in the direction outside (a position where the auxiliary holding projection 33 radially overlaps the second holding projection 67 and the third holding projection 68).

  However, in the seat reclining device 15 of the present embodiment, the second pole 31 (in particular, the center of gravity GP2) is positioned above the horizontal line LH, whereby the second pole guide grooves 24B and 24C are secondly moved. Forces F1 and F2 for moving the pole 31 obliquely downward always act (see FIG. 13). Therefore, in the unlocking range, the second pole 31 is prevented from staying at a position where the auxiliary holding projection 33 radially overlaps the second holding projection 67 and the third holding projection 68. As a result, the auxiliary holding projection 33 of the second pole 31 abuts against the stepped surface 67 a or the raised wall 67 b of the second holding projection 67 or the stepped surface 68 a or the raised wall 68 b of the third holding projection 68. , And the possibility of preventing the rotation of the ratchet plate 60 is reduced. In other words, when the ratchet plate 60 is in the unlocking range, gravity is used to prevent the second pole 31 from staying at the radially outer position that prevents the rotation of the ratchet plate 60. .

  As described above, in the seat reclining device 15, the first holding projection 66 of the ratchet plate 60 and the holding projection 32 of the first pole 30 are in a positional relationship facing in the radial direction (FIGS. 5 to 7). It becomes a lock range. The auxiliary holding projection 33 of the second pole 31 is the second holding projection 67 in a specific range in the unlocking range which is close to the boundary with the locking range (the contact area of the holding projection 32 and the first holding projection 66 decreases). The load resistance can be enhanced by facing the third holding projection 68. The auxiliary holding projection 33 of the second pole 31 radially faces the first holding projection 66 in the locking range (FIGS. 3 and 4), but the auxiliary holding projection 33 is located radially inward of the holding projection 32. As a result, the second pole 31 can be moved to the meshing position without being restricted by the first holding projection 66. That is, the circumferential length of the first holding projection 66 corresponds to the unlocking range of the ratchet plate 60, and the circumferential length of the first holding projection 66 is the auxiliary holding projection 33 of the second pole 31. It can set up without considering the interference with. As a result, the plurality of poles 30 and 31 are provided with the holding projections 32 and the auxiliary holding projections 33 for restricting movement in the radial direction to improve the strength, and the movable range in the rotational direction of the ratchet plate 60 (the amount of movement of the seatback 12 ) Can be enlarged.

  In addition, the second pole 31 which is not subjected to the radial movement restriction with respect to the auxiliary holding projection 33 in most of the unlocking range is easily moved toward the meshing release position by the downward movement force by gravity. There is. Even if the second pole 31 is temporarily moved to a position where the auxiliary holding projection 33 radially overlaps the second holding projection 67 and the third holding projection 68 due to vibration or the like, the second The pole 31 is returned radially inward under the influence of gravity to eliminate the above-mentioned overlap state. Thereby, the second pole 31 is prevented from staying in the radial position that prevents the rotation of the ratchet plate 60 in the unlocking range, and the ratchet plate 60 can be reliably rotated from the unlocking range to the locking range. Reliable and smooth operation is realized.

  As mentioned above, although this invention was demonstrated based on illustration embodiment, this invention is not limited to this embodiment, It can implement, giving a various deformation | transformation.

  For example, although two second poles 31 are provided in the above embodiment, the number of second poles in the present invention may be other than two. As an example, it may be configured to include only one second pole operating symmetrically with the first pole 30 of the above embodiment. In this case, the second pole guide groove for guiding the second pole extends vertically along the vertical line LV (FIGS. 10 and 13). The second pole in this modification always exerts a force to move it to the mesh release position side by gravity, so that the same effect as the above embodiment can be obtained. In particular, since the movement direction of the second pole to the mesh release position and the vertical direction substantially coincide with each other, the movement force by gravity can be more easily applied to the second pole.

  In the above embodiment, three poles (the first pole 30 and the two second poles 31) are arranged at substantially equal angle (120 °) intervals in the circumferential direction. Unlike this, a plurality of poles may be arranged at uneven intervals in the circumferential direction. For example, three poles (one first pole and two second poles) may be arranged at an angular interval other than 120 °, or two poles (one each of first pole and second pole) may be 180 It may be arranged at angular intervals other than °. In any form, at least the center of gravity of the second pole (pole having the second limiting portion) of the plurality of poles may be located above the rotation axis of the ratchet.

  As in the above embodiment, if at least the center of gravity CP2 of the second pole 31 is located above the horizontal line LH, even if part of the second pole 31 is located below the horizontal line LH (see FIG. 13) , The above effects can be obtained. Unlike the above embodiment, it is also possible to adopt a configuration in which the entire second pole is located above the horizontal line LH. For example, in the above-described modification in which only the first pole 30 and one second pole operating in vertical symmetry are provided, the entire second pole is positioned above the horizontal line LH.

  In the above embodiment, the radial positions of the second holding projection 67 and the third holding projection 68 in the ratchet plate 60 are the same, but the radial positions of the second holding projection 67 and the third holding projection 68 It is also possible to make For example, the amount of protrusion of the third holding projection 68 inward in the radial direction from the second holding projection 67 is increased, and the diameters of the first holding projection 66, the second holding projection 67, and the third holding projection 68 are set. The directional position (the positions of the holding surfaces 66b, 67c and 68c facing inward in the radial direction) may be configured to be different in three steps. In this case, in accordance with the radial position of the third holding projection 68, the position of the auxiliary holding projection 33 is changed radially inward by one of the two second poles 31. The above-mentioned effect in seat reclining device 15 can be acquired also by this composition.

  The auxiliary holding projection 33 provided on the second pole 31 in the above embodiment has the longitudinal direction in the rotational direction of the ratchet plate 60, but the longitudinal direction of the auxiliary holding projection 33 may be changed in the radial direction or the like. It is possible. Alternatively, it is also possible to set the auxiliary holding projection 33 in a cylindrical shape or the like which does not have a specific longitudinal direction. In any form, as shown in FIG. 7, the auxiliary holding projection 33 with respect to the second holding projection 67 and the third holding projection 68 is in a state in which the contact area between the holding projection 32 and the first holding projection 66 is minimized. It is desirable to set the arrangement in such a way that they face in the radial direction.

  The radial movement of each pole in the present invention is not limited to linear movement. For example, although the first pole 30 and the second pole 31 in the above embodiment are configured to move linearly in the radial direction with respect to the base plate 20, an arc shape including a moving component in the radial direction and a moving component in the circumferential direction The present invention can also be applied to a configuration in which each pole moves in a trajectory.

  In the seat reclining device 15 of the above embodiment, the first pole 30 and the second pole 31 are moved to the meshing position and the meshing release position by the combination of the rotating cam 40 and the release plate 50. The respective poles 30, 31 may be driven by drive members other than the above. It is preferable to use a member that rotates at the same rotation center as the ratchet plate 60, such as the rotation cam 40 and the release plate 50, from the viewpoint of space efficiency and drive efficiency, but it is also possible to use members of different operation forms such as linear movement. It is. It is also possible to use a drive member in which the rotating cam 40 and the release plate 50 are integrated.

  In the above embodiment, of the left and right frames constituting each of the seat cushion 11 and the seat back 12, the right side frame is connected by the seat reclining device 15 toward the traveling direction of the vehicle. The seat reclining device 15 may connect between the left frames. Further, the left and right frames are connected by the seat reclining device 15, and the rotating cams 40 of the left and right seat reclining devices 15 are connected by a connection pipe or the like to interlock the movement of the left and right seat reclining devices 15. It is also good.

10: reclining seat 11: seat cushion 12: seat back 15: seat reclining device 20: base plate (base member)
21: shaft insertion hole 22: large diameter annular flange 23: groove forming projection 23a: guiding plane 23b: guiding plane 24: guiding groove 24A: first pole guiding groove 24B: second pole guiding groove (second pole guiding portion (second pole guiding portion) )
24C: Second pole guide groove (second pole guide portion)
25: Spring hooked recess 30: first pole 31: second pole 32: holding projection (first limiting portion)
32a: outer side surface 32b: inner side surface 32c: connection surface 32d: connection surface 33: auxiliary holding projection (second limiting portion)
33a: outer surface 33b: inner surface 33c: connection surface 33d: connection surface 34: cam follower 35: outer tooth 36: controlled portion 37: pressed portion 40: rotating cam 41: central non-circular hole 42: suppressed portion 43: pressed Part 44: Anti-rotation projection 45: Spring engagement recess 50: Release plate 51: Central opening 52: Cam hole 52a: Lock allowance part 52b: Unlock part 53: Anti-rotation hole 60: Ratchet plate (ratchet)
61: Small-diameter annular flange 62: Shaft insertion hole 63: Base portion 64: Intermediate annular portion 65: Internal teeth 66: First holding projection (first pole regulation portion)
66a: step surface 66b: holding surface 67: second holding projection (second pole regulating portion)
67a: step surface 67b: standing wall surface 67c: holding surface 68: third holding projection (second pole regulating portion)
68a: step surface 68b: vertical wall surface 68c: holding surface 70: lock spring 71: first locking portion 72: second locking portion 80: pressing ring 90: control lever 91: shaft GP1: center of gravity GP1 of the first pole Center of gravity LH of second pole: horizontal line LV: vertical line RX: rotation axis

Claims (2)

A base member provided on the seat cushion;
A ratchet provided on the seat back and having internal teeth and rotatable relative to the base member about an axis of rotation;
A meshing position supported movably in a radial direction about the rotation axis with respect to the base member, a meshing position meshing with the internal teeth, and a plurality of poles moving to a meshing release position canceling the meshing;
Equipped with
The plurality of poles includes a first pole having a first limit and a second pole having a second limit.
The ratchet contacts the first pole restricting portion that restricts the movement of the first pole to the meshing position by contact with the first restricting portion, and the meshing position to the meshing position by abutting the second restricting portion. And a second pole restricting portion for restricting the movement of the second pole;
The second restricting portion is disposed radially inward of the first restricting portion, and the second pole restricting portion is disposed radially inward of the first pole restricting portion.
In an unlocking range in which the first pole restricting portion and the first restricting portion face in the radial direction and the ratchet can always rotate with respect to the base member, the specific range is a part of the unlocking range. The second pole restricting portion and the second restricting portion face in the radial direction,
The seat reclining device according to claim 1, wherein the center of gravity of the second pole is located above a horizontal line passing through the rotation axis. The base member has a second pole guide portion which guides the second pole movably in the radial direction while restricting movement of the second pole in the rotational direction about the rotation axis.
2. The seat reclining device according to claim 1, wherein the second pole guide portion is a linear groove-shaped portion extending downward as approaching the rotation axis in the radial direction.

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