JP5638909B2 - Reclining device - Google Patents

Description

  The present invention includes a first member formed with internal teeth along a circumferential direction, a plurality of poles having external teeth meshable with the internal teeth, and relative rotation in the circumferential direction with the first member. And a second member formed with a first guide for sandwiching both side surfaces of each pole and guiding each of the poles in the radial direction of the circumference, and the outer teeth of the first member The present invention relates to a reclining device in which relative rotation between the first member and the second member is prohibited by meshing with teeth.

  An example of a conventional reclining device will be described with reference to FIGS. FIG. 9 is an exploded perspective view of a conventional reclining device for a vehicle seat, and FIG. 10 is a configuration diagram of the seat.

  As shown in FIG. 10, the seat 1 includes a seat cushion 2 that supports a seated person's buttocks, and a seat back 3 that is provided so as to be tiltable in the front-rear direction with respect to the seat cushion 2 and that supports the back part of the seated person. It has become. Reference numeral 4 denotes a reclining device that is provided on the rotation axis of the tilt of the seat back 3 and permits / inhibits the tilt of the seat back 3.

  As shown in FIG. 9, the reclining device includes a first member 7 in which inner teeth 7 a are formed along the circumferential direction, and a hole 7 b penetrating along the central axis of the circumference is formed. It has the member 7 and the 2nd member 5 provided in the said circumferential direction so that relative rotation was possible, and the hole 5b penetrated along the central axis of the said circumference was formed. In this conventional example, the first member 7 is attached to the seat back 3 side, and the second member 5 is attached to the seat cushion 2 side.

  Between the first member 7 and the second member 5, four poles 10 having external teeth 10a that can mesh with the internal teeth 7a are arranged. The second member 5 is formed with guides 5a that guide the poles 10 in the radial direction with both side surfaces of the poles 10 interposed therebetween. Further, between the first member 7 and the second member 5, a cam 9 is rotatably supported by the hole 7 b of the first member and the hole 5 a of the second member 5, and rotates on the rotation axis of relative rotation. Has been placed. In the peripheral part of the cam 9, a concave part 9 a and a protruding part 9 b are formed along the circumferential direction according to each pole 10. Further, on the surface of each pole 10 opposite to the surface on which the external teeth 10a are formed, there are a recess 10b into which the protrusion 9b of the cam 9 can enter and a protrusion 10c that can enter into the recess 9a of the cam 9. Is formed.

  For this reason, when the cam 9 is rotated in one direction, the protrusion 9b of the cam 9 pushes the surface 10d opposite to the external teeth 10a of the pole 10 (hereinafter referred to as the back surface), and the external teeth 10a become the first member 7. The pole 10 is driven in the direction of meshing with the inner teeth 7a. Conversely, when the cam 9 is rotated in the other direction, the protrusion 9b of the cam 9 enters the recess 10b of the pole 10, and the external teeth 10a pulls the pole 10 away from the internal teeth 7a of the first member 7. It is like that.

  When the back surface 10d of each pole 10 is pushed by the protrusion 9b of the cam 9, the force that moves the pole 10 in the direction in which the outer teeth 10a mesh with the inner teeth 7a, and the second member 5 side, It is a surface (slope) on which a force for moving the pole 10 to the surface of the guide 5a on the counterclockwise direction is generated.

  The first member 7 is provided with a stopper plate 11 having a hole 11a formed at the center. The stopper plate 11 is formed with four holes 11a, and the four protrusions 7c formed on the first member 7 are fitted into these holes 11a so that the stopper plate 11 is fixed. The stopper protrusion 5c formed on the second member 5 is formed on the standing wall 11c of the protrusion 11b formed on the stopper plate 11 fixed to the first member 7. The first member 7 and the second member 5 can be rotated relative to each other within a range in contact with the standing wall portion 11d of the projection 11b formed on the stopper plate 11 fixed to the first member 7. That is, the seat back 3 can tilt within the range of the angle θ in FIG.

  In addition, the spring 9 whose outer end is locked to the second member 5 and whose inner end is locked to the cam 9 causes the cam 9 to move in one direction, that is, the outer teeth 10 a of the pole 10 are in the first member 7. The inner teeth 7a are biased in the direction of meshing.

  Normally, each pole 10 provided on the second member 5 is in a locked position where the outer teeth 10a mesh with the inner teeth 7a of the first member 7 by the biasing force of the spring 13, and the first member 7 and the second member Relative rotation with the member 5 is prohibited, and the seat back 3 is in a state where it cannot rotate relative to the seat cushion 2 (locked state).

  When the cam 9 is operated against the urging force of the spring 13 and rotated in the other direction, each pole 10 moves to the unlocked position where the engagement between the external teeth 10a and the internal teeth 7a is released. The first member 7 and the second member 5 can rotate relative to each other, and the seat back 3 can rotate relative to the seat cushion 2.

  When the operating force on the cam 9 is released, the external teeth 10a of the poles 10 provided on the second member 5 are engaged with the internal teeth 7a of the first member 7 by the biasing force of the spring 13, and the first member 7 is engaged. And relative rotation between the second member 5 and the second member 5 are prohibited, and the locked state is established again.

JP 2009-247395 A

  However, in the reclining device shown in FIG. 9, when the back surface 10d of the pole 10 is all pushed by the protrusion 9b of the cam 9, the force that moves the pole 10 in the direction in which the external teeth 10a mesh with the internal teeth 7a, When viewed from the two-member 5 side, this is a surface on which a force for moving the pole 10 to the surface of the guide 5a on the counterclockwise side is generated.

  When the pole 10 is pushed by the cam 9, the pole 10 moves to the surface of the guide 5a on the counterclockwise direction when viewed from the second member 5 side, and is in contact with the guide 5a on the counterclockwise side. The teeth 10a mesh with the inner teeth 7a. On the other hand, the pole 10 has a gap with respect to the guide 5a on the clockwise side when viewed from the second member 5 side.

  When the vehicle collides forward (front collision) and a force is applied to the reclining device to rotate the first member 7 counterclockwise as viewed from the second member 5, the pole 10 moves to the second member 5 side. Since it is in contact with the surface of the guide 5a on the counterclockwise direction, the lock strength is high.

  However, when the vehicle collides backward (rear collision) and a force to rotate the first member 7 clockwise as viewed from the second member 5 acts on the reclining device, the pole 10 moves to the second member 5. Since there is a gap with respect to the surface of the guide 5a on the clockwise side when viewed from the side, the external teeth 10a of the pole 10 move along the tooth surfaces of the internal teeth 7a in the direction in which the meshing is released, and the lock strength is increased. Lower.

  That is, there is a problem that the lock strength of the reclining device is different between the front collision and the rear collision.

  The present invention has been made in view of the above problems, and an object thereof is to provide a reclining device in which a difference in lock strength between a front collision and a rear collision is small.

The invention according to claim 1, which solves the problem, includes a first member in which inner teeth along a circumferential direction are formed, a plurality of poles having outer teeth that can mesh with the inner teeth, and the first member. Between the lock position where the outer teeth mesh with the inner teeth, and the outer teeth between the unlock positions where the outer teeth are separated from the inner teeth. The second member formed with a guide for guiding the poles and the outer teeth mesh with the inner teeth of the first member, so that relative rotation between the first member and the second member is prohibited. At least two of the first cam and the plurality of poles disposed between the first member and the second member and capable of rotating on the rotation shaft of the relative rotation. When placed between the above poles and pushed by the first cam, The surface of the pole opposite to the surface on which the external teeth are provided is pressed to move each of the poles in a direction in which the external teeth mesh with the internal teeth, and the clockwise side when viewed from the second member. A second cam that moves the pole to one of a surface of the guide and a surface of the guide on the counterclockwise side, and a pressing contact between the second cam and each of the poles. At least one pressing contact moves the pole to the surface of the guide on the clockwise side as viewed from the second member, and the other pressing force is on the guide on the counterclockwise side as viewed from the second member. The reclining device is characterized in that the pole is moved to a surface, and the first cam has a portion on which the surface on the opposite side to the surface on which the external teeth of the pole are provided can contact .

  According to the first aspect of the present invention, the first cam disposed between the first member and the second member and rotatable on the rotation shaft of the relative rotation, the first cam, and the plurality of poles When the first cam is disposed between at least two or more poles, the surface opposite to the surface provided with the external teeth of the pole is pressed and the external teeth are in contact with the internal teeth. The poles are moved in the meshing direction, and the poles are moved to one of the guide surface on the clockwise side and the guide surface on the counterclockwise side as viewed from the second member. A second cam to be moved, and at least one of the pressing contact between the second cam and each of the poles moves the pole to the guide surface on the clockwise side when viewed from the second member. The other pressing contact is the counterclockwise side of the gas as viewed from the second member. By the de surface adapted to move the pawl, front collision, the difference in locking strength is reduced in rear impact.

In addition , the first cam has a portion that can contact the surface opposite to the surface on which the external teeth of the pole are provided, so that the external teeth of the pole mesh with the internal teeth of the first member. When the force of relative rotation between the first member and the second member acts on the reclining device and the pole is inclined, the surface opposite to the surface on which the external teeth of the pole are provided abuts on the first cam. The tilt of the pole is prohibited and the lock strength does not decrease.

It is a disassembled perspective view of the reclining apparatus of this embodiment. It is the perspective view seen from the arrow C direction at the time of attaching the reclining apparatus of FIG. It is the figure seen from the arrow C direction in the state which removed the outer periphery ring and ratchet at the time of attaching the reclining apparatus of FIG. In FIG. 3, it is sectional drawing in the cutting | disconnection line AA in the state which assembled | attached the outer periphery ring and the ratchet. In FIG. 3, it is sectional drawing in the cutting | disconnection line BB in the state which assembled | attached the outer periphery ring and the ratchet. It is the figure seen from the arrow D direction at the time of attaching the reclining apparatus of FIG. It is the figure seen from the arrow E direction at the time of attaching the reclining apparatus of FIG. It is a block diagram of the other form example. It is a disassembled perspective view of the conventional reclining device for seats of vehicles. It is a lineblock diagram of a sheet.

  Next, embodiments of the present invention will be described with reference to the drawings.

  Similar to the reclining device 4 shown in FIG. 10, the glue climbing device according to the present embodiment is provided on the rotation axis of the tilt of the seat back 3.

  The reclining apparatus of this embodiment is demonstrated using FIGS. 1-7. 1 is an exploded perspective view of the reclining device of the present embodiment, FIG. 2 is a perspective view seen from the direction of arrow C when the reclining device of FIG. 1 is assembled, and FIG. 3 is an outer periphery when the reclining device of FIG. FIG. 4 is a view seen from the direction of arrow C with the ring and ratchet removed, FIG. 4 is a cross-sectional view taken along the line A-A in the state where the outer ring and ratchet are assembled, and FIG. 5 is FIG. FIG. 6 is a cross-sectional view taken along the line BB when the outer ring and the ratchet are assembled, FIG. 6 is a view seen from the direction of arrow D when the reclining device of FIG. 1 is assembled, and FIG. 7 is the reclining device of FIG. It is the figure seen from the arrow E direction at the time of attaching.

  In FIG. 1, a ratchet (first member) 21 provided on the seat back side is formed by half-cutting a disk-like plate material by a press to form a circular recess 21a. Inner teeth 23 are formed in the entire circumferential direction on the inner circumferential surface of the circular recess 21a. A through hole 21b is formed at the center of the circular recess 21a.

  The base plate (second member) 25 provided on the seat cushion side is also formed by half-cutting a disk-shaped plate material by pressing to form a circular recess 25a. The diameter of the circular recess 25 a is set slightly larger than the outer diameter of the ratchet 21. And the ratchet 21 is engage | inserted by the circular recessed part 25a, and the baseplate 25 and the ratchet 21 can be rotated relatively. A through hole 25 b is formed in the center of the ratchet 21. The diameter of the hole 25b of the base plate 25 is set larger than the diameter of the hole 21a of the ratchet 21.

  The outer peripheral portion of the ratchet 21 and the outer peripheral portion of the base plate 25 are sandwiched by a ring-shaped outer peripheral ring 27, and the ratchet 21 and the base plate 25 are separated in the direction of the axis of relative rotation (O in FIG. 1). Without being relatively rotatable.

  In the space formed by the circular recess 21a of the ratchet 21 and the circular recess 25a of the base plate 25, the first cam 31 including the cam body 31c, the first shaft portion 31a, and the second shaft portion 31b is disposed. The first shaft portion 31 a is formed on one surface side of the cam body 31 c and is rotatably supported in the hole 21 a of the ratchet 21. The second shaft portion 31b is formed on one surface side of the first cam 31 so as to be coaxial with the first shaft portion 31a. In the present embodiment, the first shaft portion 31a and the second shaft portion 31b are oval cylinders having the same cross section.

  A release plate 33 is disposed between the first cam 31 and the circular recess 21 a of the ratchet 21. An oval hole 33a that is slightly larger than the cross-sectional shape of the first shaft portion 31a of the first cam 31 is formed at the center of the release plate 33. When the first shaft portion 31a of the first cam 31 is inserted into the hole 33a, the first cam 31 and the release plate 33 rotate together.

  As shown in FIGS. 1, 2, and 3, a total of four poles 41 and 43 are arranged along the circumferential direction between the release plate 33 and the circular recess 25 a of the base plate 25. Yes. Furthermore, as shown in FIG. 3, the pole 41 and the pole 43 have a symmetrical shape (axisymmetric shape) with respect to a line segment along the radial direction of the circumference.

  Outer teeth 41 a and 43 a that can mesh with the inner teeth 23 are formed on the surfaces of the poles 41 and 43 facing the inner teeth 23.

  In the circular recess 25a of the base plate 25, two first protrusions 35 protruding in the direction of the ratchet 21 are formed at intervals of 180 ° along the circumferential direction. Between the two first protrusions 35, two second protrusions 37 and two third protrusions 39 are formed at intervals of 180 ° along the circumferential direction. Both side portions of the first projecting portion 35 are guide surfaces 35a and 35b which are orthogonal to the bottom surface of the circular recess 25a of the base plate 25 and parallel to the radial direction of the circumference. Both side portions of the second projecting portion 37 are guide surfaces 37a and 37b which are orthogonal to the bottom surface of the circular concave portion 25a of the base plate 25 and parallel to the radial direction of the circumference. Both side portions of the third protrusion 39 are guide surfaces 39a and 39b which are orthogonal to the bottom surface of the circular recess 25a of the base plate 25 and parallel to the radial direction of the circumference.

  And the space | interval of the guide surface 35a of the 1st protrusion part 35 and the guide surface 39a of the 3rd protrusion part 39 is set a little wider than the width | variety of the pole 41, and the pole 41 is arrange | positioned between these two guide surfaces. Thus, the first protrusion 35 and the third protrusion 39 function as a guide (first guide) for guiding the pole 41 in the circumferential radial direction. Similarly, the guide surface 35b of the first projecting portion 35 and the guide surface 37a of the second projecting portion 37 are set slightly wider than the width of the pole 43, and the pole 43 is arranged between these two guide surfaces. Thus, the first protrusion 35 and the second protrusion 37 function as a guide (first guide) for guiding the pole 43 in the radial direction of the circumference.

  A protrusion 41b that protrudes in the direction of the first cam 31 is formed on the first protrusion 35 side of the surface opposite to the surface on which the external teeth 41a of the pole 41 are formed (hereinafter referred to as the back surface). On the 39 side, a recess 41c is formed. A protrusion 43b protruding in the direction of the first cam 31 is formed on the first protrusion 35 side of the surface opposite to the surface on which the external teeth 43a of the pole 43 are formed (hereinafter referred to as the back surface). On the side of the two projecting portions 37, a recess 43c is formed.

  And the 2nd cam 45 is arrange | positioned so that the two adjacent poles 41 and 43 may be straddled via the 2nd protrusion part 37 and the 3rd protrusion part 39. FIG. The second cam 45 includes a main body portion 45 a and a guide portion 45 b extending toward the internal teeth 23. On the other hand, the distance between the guide surface 37b of the second projecting portion 37 and the guide surface 39b of the third projecting portion 39 is set slightly larger than the width of the guide portion 45b of the second cam 45, and between these two guide surfaces. By arranging the guide portion 45b of the second cam 45, the second protrusion 37 and the third protrusion 39 function as a guide (second guide) for guiding the second cam 45 in the circumferential radial direction.

  Lock portions 45 d and 45 c that can come into contact with the recess 41 c of the pole 41 and the recess 43 c of the pole 43 are formed on the surface of the main body 45 a of the second cam 45 that faces the pole 41 and the pole 43.

  On the periphery of the cam main body 31c of the first cam 31, there are formed a pole 41, a protrusion 41b formed on the back surface of the pole 43, and four pole protrusions 31d with which the protrusion 43b can abut. Further, when the first cam 31 rotates in one direction on the peripheral portion of the cam body 31c of the first cam 31, the side opposite to the surface on which the lock portions 45c and 45d of the body portion 45a of the second cam 45 are formed. The second cam projection 31e that pushes the pole 41 and the pole 43 in the direction in which the outer teeth 41a and the outer teeth 43a mesh with the inner teeth 23 of the ratchet 21 is formed.

  In the present embodiment, the surfaces of the recess 41c of the pole 41 with which the lock portions 45d and 45c of the second cam 45 abut and the surface of the recess 43c of the pole 43 are pressed against each other by the lock portions 45d and 45c of the second cam 45. A force that drives the pole 41 and the pole 43 in a direction in which the outer teeth 41a and the outer teeth 43a mesh with the inner teeth 23 of the ratchet 21 and a force that pushes the pole 41 and the pole 43 toward the first projecting portion 35 are generated. It is a gentle slope.

  That is, of the pressing contact between the second cam 45 and the poles 41, 43, the pressing contact between the second cam 45 and the pole 41 is performed by the first guide 35 on the clockwise side when viewed from the base plate (second member) 25. The pole 41 is moved to the surface 35 a, and the other pressing contact between the second cam 45 and the pole 43 is the surface 35 b of the first guide 35 on the counterclockwise side when viewed from the base plate (second member) 25. The pole 43 is moved.

  The outer end of the hole 25b of the base plate 25 is locked to one of the two grooves 25c extending in the radial direction formed on the wall peripheral surface of the hole 25b, and the inner end is the first end. A spiral spring 47 wound around a second shaft portion 31b having a cross-sectional shape of the cam 31 is disposed. Due to the biasing force of the spiral spring 47, the first cam 31 is biased in a direction in which the outer teeth 41 a and the outer teeth 43 a of the pole 41 and the pole 43 mesh with the inner teeth 23 of the ratchet 21.

  The pole 41, the pole 43, and the second cam 45 are formed with a protrusion 41d, a protrusion 43d, and a protrusion 45e that protrude in the direction of the release plate 33, respectively. On the other hand, the projection 41d of the pole 41, the projection 43d of the pole 43, and the projection 45e of the second cam 45 are engaged with the release plate 33 and rotated, whereby the pole 41, the pole 43, and the second cam 45 are rotated. A cam hole 33b and a cam hole 33c are formed. When the first cam 31 (release plate 33) is rotated in the other direction, the cam holes 33b and 33c are arranged so that the external teeth 41a and the external teeth 43a are separated from the internal teeth 23 of the ratchet 21. The second cam 45 is formed in a shape that pulls up.

  On the inner wall surface of the ratchet 21 on the bottom surface side of the circular recess 21a from the inner teeth 23, a pair of protrusions 51 are formed that protrude toward the center of the circumference along the circumferential direction. The second cam 45 is formed with a protrusion 45 f that can ride on the top of the protrusion 51. When the protrusion 45f of the second cam 45 rides on, the protruding amount of the protruding portion 51 is set to an amount that holds the pole 41 and the pole 43 at a position where the outer teeth 41a and the outer teeth 43a are separated from the inner teeth 23 of the ratchet 21. ing. When the protrusion 45f of the second cam 45 rides on the protrusion 51, the first cam 31 rotates in one direction (the pole 41, the external teeth 41a of the pole 43, and the external teeth 43a on the internal teeth 23 of the ratchet 21). (Rotation in the meshing direction) is prohibited, and the ratchet 21 and the base plate 25 can be rotated relative to each other without operating the first cam 31.

  Next, the operation of the above configuration will be described.

  Usually, the outer teeth 41a of the pole 41 on the base plate 25 side and the outer teeth 43a of the pole 43 mesh with the inner teeth 23 of the ratchet 21 via the first cam 31 and the second cam 45 by the biasing force of the spiral spring 47. In the position, the relative rotation between the ratchet 21 and the base plate 25 is prohibited, and the seat back is in a state where it cannot rotate relative to the seat cushion (locked state).

  When the first cam 31 is operated against the biasing force of the spring 47 and rotated in the other direction, the release plate 33 that rotates together with the first cam 31 rotates, and the external teeth 41a and the external teeth 43a are ratchet. The pole 41, the pole 43, and the second cam 45 are pulled up in a direction away from the internal teeth 23 of the 21. The pole 41, the pole 43, and the second cam 45 are connected to the external teeth 41a, the external teeth 43a, and the internal teeth 23 of the ratchet 21. Accordingly, the ratchet 21 and the base plate 25 can rotate relative to each other, and the seat back 3 can rotate relative to the seat cushion 2.

  When the protrusion 45f of the second cam 45 rides on the protrusion 51, the ratchet 21 and the base plate 25 can be rotated relative to each other without operating the first cam 31.

  When the operating force on the first cam 31 is released, the urging force of the spiral spring 47 causes the pole 41 provided on the base plate 25, the external teeth 43a of the pole 43, and the external teeth 43a to mesh with the internal teeth 23 of the ratchet 21. The relative rotation between the ratchet 21 and the base plate 25 is prohibited and the locked state is established again.

  In the present embodiment, of the pressing contact between the second cam 45 and the poles 41, 43, the pressing contact between the second cam 45 and the pole 41 is the first in the clockwise direction when viewed from the base plate (second member) 25. The pole 41 is moved to the surface 35 a of the guide 35, and the second cam 45 and the pole 43, which are other pressing contacts, are the first guide 35 on the counterclockwise side when viewed from the base plate (second member) 25. The pole 43 is moved to the surface 35b.

  One of the pressing contact between the second cam 45 and the pole 41 and the pressing contact between the second cam 45 and the pole 43 is strong against the rear impact and weak against the front impact, and the other is strong against the front impact and weak against the rear impact. .

  In the present embodiment, there are two pressings between the second cam 45 and the poles 41 and 43, respectively. Therefore, the reclining device has the same lock strength in the front collision and the rear collision.

  Furthermore, on the periphery of the cam body 31c of the first cam 31, there are formed a pole 41, a protrusion 41b formed on the back surface of the pole 43, and four pole protrusions 31d with which the protrusion 43b can abut. Thus, the ratchet (first member) 21 and the base plate 25 (second member) rotate relative to each other in a state where the outer teeth 41a and 43a of the pole 41 and the pole 43 mesh with the inner teeth 23 of the ratchet (first member) 21. If the force to act on the reclining device and the pole 41 and the pole 43 try to tilt, the projection 41b and the projection 43b of the pole 41 and the pole 43 come into contact with the projection 31d of the first cam 31, and the pole 41 and the pole 43 The inclination of 43 is prohibited and the lock strength does not decrease.

  The present invention is not limited to the above embodiment. In the above embodiment, the two second cams 45 are used, but two poles may be driven by one second cam, and the other poles may be driven by the first cam.

  That is, of the pressing contact between the second cam and the pole, the pressing contact between at least one second cam and the pole is directed to the surface 35 a of the first guide 35 on the clockwise side when viewed from the base plate (second member) 25. The pole 41 is moved, and the other second cam and the pole are pressed so as to move the pole 43 to the surface 35b of the first guide 35 on the counterclockwise side when viewed from the base plate (second member) 25. For example, all the poles are moved to the surface 35a of the first guide 35 on the clockwise side as viewed from the base plate (second member) 25 or the surface 35b of the first guide 35 on the counterclockwise side. The difference in lock strength between the front and rear collisions is reduced.

  In the above embodiment, two poles are driven by one second cam. For example, a circular second cam is provided between each pole and the first cam, and one second cam is used. A single pole may be driven.

  Further, in the above embodiment, the ratchet 21 is provided on the seat back side and the base plate 25 is provided on the seat cushion side. However, the ratchet 21 may be provided on the seat cushion side and the base plate 25 may be provided on the seat back side.

  Furthermore, in the above embodiment, the pole 41 is linearly moved in the radial direction of the circumference by being guided by the first protrusion 35 and the third protrusion 39 and the pole 43 is guided by the first protrusion 35 and the second protrusion 37. However, the present invention can also be applied to a reclining device configured as shown in FIG. FIG. 8 is a view for explaining another embodiment, and is a view of the ratchet as seen from the base plate side with the base plate removed.

  In the figure, an internal tooth 107 is formed along a circumferential direction of relative rotation on a ratchet 105 provided so as to be relatively rotatable with a base plate (not shown).

  The four poles 101 are provided so as to be rotatable around a projecting portion 103 whose cross-sectional shape provided on a base plate (not shown) has a substantially meniscus shape. External teeth 109 that can mesh with the internal teeth 107 are formed on the surface side of the pole 101 facing the internal teeth 107 of the ratchet 105 on one rotating end side. Further, a protrusion 101 a is formed on a surface opposite to the surface facing the inner teeth 107 of the ratchet 105 on the other rotating end side of the pole 101.

  The base plate sandwiches both side surfaces of each pole 101 and serves as a guide for guiding each pole 101 between a locked position where the outer teeth 109 are engaged with the inner teeth 107 and an unlocked position where the outer teeth 109 are separated from the inner teeth 107. The protruding portion 111 and the protruding portion 113 are formed.

  A shaft 114 rotatably supported by the ratchet 105 is provided on an axis of relative rotation between the base plate and the ratchet 105. Between the base plate and the ratchet 105, there is provided a first cam 115 that is fixed to the shaft 114 and rotates together with the shaft 114. Protrusions 115a and 115b with which the surface opposite to the surface on which the external teeth 109 of the pole 101 are formed (hereinafter referred to as the back surface) can be formed on the peripheral portion of the first cam 115. In the drawing, when the first cam 115 rotates counterclockwise, the projections 115a and 115b push the projection 101a of the pole 101, and the pole 101 is rotated in the direction in which the outer teeth 109 are separated from the inner teeth 107.

  On the other hand, two second cams 117 are arranged so as to straddle two adjacent poles 101. When the first cam 115 rotates in the clockwise direction in the drawing, the second cam 117 is pushed, and the second cam 117 pushes the surface opposite to the surface on which the external teeth 109 of the two poles 101 are provided. The pole 101 is rotated in a direction in which 109 meshes with the internal teeth 107. Further, in this embodiment, the surface of the pole 101 with which the second cam 117 abuts is pressed against the force by which the outer teeth 109 engage with the inner teeth 107 of the ratchet 105 and the pole 101 is pushed by the protruding portion 111. It is a slope where force is generated.

  That is, in this embodiment, of the pressing contact between the second cam 117 and the two poles 101, the pressing contact between the second cam 117 and one of the poles 101 is clockwise when viewed from the base plate (second member). The pole 101 is moved to the surface of the projecting portion 111, and the other cam 101 and the other pole 101 are pressed against each other, so that the pole 101 moves to the surface of the projecting portion 111 on the counterclockwise side when viewed from the base plate. Is moving.

  Of the pressing contact between the second cam 117 and one pole 101 and the pressing contact between the second cam 117 and the other pole 101, either one is strong in the rear impact and weak in the front impact, and the other is strong in the front impact and the rear. Suddenly weak.

  In the present embodiment, there are two pressings between the second cam 117 and the pole 101, respectively. Therefore, the difference in the locking strength of the reclining device is small between the front collision and the rear collision.

  Further, projections 115a and 115b with which the back surface of the pole 101 can come into contact are formed on the peripheral portion of the first cam 115, so that the external teeth 109 of the pole 101 are engaged with the internal teeth 107 of the ratchet 105. Thus, when the force of the relative rotation between the ratchet 105 and the base plate acts on the reclining device and the pole 101 tries to tilt, the protrusion 101a of the pole 101 comes into contact with the protrusions 115a and 115b of the first cam 115, and the pole 101 The tilt of 101 is prohibited and the lock strength does not decrease.

21 Ratchet (first member)
25 Base plate (second member)
31 1st cam 35,37 1st guide 35,39 1st guide 41,43 Pole 41a, 43a External tooth 45 2nd cam

Claims (1)

A first member formed with internal teeth along the circumferential direction;
A plurality of poles having external teeth meshable with the internal teeth;
A lock position that is provided so as to be rotatable relative to the first member in the circumferential direction, sandwiches both side surfaces of each pole, and the outer teeth engage with the inner teeth, and the outer teeth are separated from the inner teeth. A second member formed with a guide for guiding each of the poles between locked positions;
In the reclining device in which relative rotation between the first member and the second member is prohibited by meshing the outer teeth with the inner teeth of the first member,
A first cam disposed between the first member and the second member and rotatable on a rotation shaft of the relative rotation;
The first cam is disposed between at least two of the plurality of poles, and when pressed by the first cam, presses against a surface opposite to the surface on which the external teeth of the pole are provided. The outer teeth move the poles in the direction of meshing with the inner teeth, and the guide surface on the clockwise side as viewed from the second member, and the guide surface on the counterclockwise side, A second cam for moving the pole to one of the surfaces;
Provided,
At least one pressing contact between the second cam and each pole moves the pole to the surface of the guide on the clockwise side when viewed from the second member,
The other pressing is to move the pole to the surface of the guide on the counterclockwise side as viewed from the second member ,
The reclining device , wherein the first cam has a portion on which a surface opposite to a surface on which the external teeth of the pole are provided can come into contact .

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