JP2006288741A - Reclining device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a reclining device capable of stably obtaining high locking strength. <P>SOLUTION: The reclining device has such a structure that, when a load is applied from a ratchet plate 130 to a pole 150, the pole 150 is inclined and the pole 150 is supported by the inclined cam surface 175b and support surface 175a of a cam 170. The support surface 175a is composed of a first inclined surface 175e inclined in the same direction as the inclined cam surface 175b and a second inclined surface 175f inclined in the opposite direction of the inclined cam surface 175b. On the end part of the rear end face 156 of the pole 150, first and second projection parts 150e and 150f which can be abutted to the first and second inclined surfaces 175e and 175f are provided. For the first inclined surface 175e, an outer peripheral surface is formed so as to reduce a distance between the part and the rotation center of the cam 170 more for the part in a rotating direction in locking. On the contrary, for the second inclined surface 175f, the outer peripheral surface is formed so as to increase the distance between the part and the rotation center of the cam 170 more for the part in the rotating direction in locking. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a reclining device that adjusts the angle of a backrest of a vehicle seat. More specifically, the ratchet plate is rotatably overlapped with the base plate, the operation shaft is disposed on the rotation center axis thereof, and the ratchet plate facing the base plate has a circular shape centering on the operation shaft. A recess is formed, and an inner tooth is formed on the inner peripheral wall surface of the recess, and a pole having an outer tooth on the front end surface side that can be engaged and disengaged from the radial direction of the tip circle is arranged in the recess. On the other hand, the base plate is provided with a guide projection for sliding and guiding the pole in the radial direction, and a cam that can be rotated together with the operation shaft is disposed in the space on the rear end face side of the pole. The cam is urged in a direction that presses the rear end face of the pole and meshes the external teeth of the pole with the internal teeth of the ratchet plate, and with the operation shaft against the urging force of the urging means. When rotating the arm is a release means pole is forcibly moved to the rotation center side of the cam relates to a reclining device for disengaging the outer teeth of the pole from the inner teeth of the ratchet plate.

  As this type of reclining device, not only the first step portion (inclined cam surface) that contacts the rear end surface of the pole but also the second step portion (support surface) that can contact the arm portion provided on the pole. ). In this reclining device, during the meshing operation, the first step portion of the cam presses the rear end surface of the pole to move the pole, and the external teeth of the pole are meshed with the internal teeth of the ratchet plate (the second time during this movement) And the arm of the pole do not touch).

On the other hand, when a load is applied from the ratchet plate to the pole due to a vehicle collision or the like during locking when the external teeth of the pole and the internal teeth of the ratchet plate are engaged, the pole is slightly inclined and the second cam And the pole is supported at two points by the first and second step portions of the cam. In addition, the peripheral shape of the 2nd step part of the cam in a conventional apparatus is a circular arc centering on the rotation center of a cam (for example, refer patent document 1).
Japanese Patent No. 3115231 (FIGS. 1 to 4)

  In this type of reclining device, the cam rotation stop position and the radial movement amount of the pole in the locked state in which perfect engagement between the external teeth of the pole and the internal teeth of the ratchet plate is present. Will vary from product to product. In other words, even if the amount of movement of the pole in the radial direction is small, some of the outer teeth are completely engaged with the inner teeth of the ratchet plate. Some do not fully engage the internal teeth of the plate.

  Here, as described above, the peripheral shape of the second step portion of the cam is an arc centered on the rotation center of the cam in the conventional device, so that the external teeth of the pole and the internal teeth of the ratchet plate are The gap between the second step portion of the cam and the arm portion of the pole in the locked state in which complete engagement is obtained is not constant.

  In the locked state, the gap between the second step portion of the cam and the arm portion of the pole affects the locking strength. However, in the conventional apparatus, when the movement amount of the pole in the radial direction is large, the second step of the cam The gap between the arm and the arm of the pole becomes excessively large, and the lock strength may be greatly reduced.

  The present invention solves the above-described problems, and an object thereof is to realize a reclining device that can stably obtain a high lock strength.

  In the invention according to claim 1 which solves the above-mentioned problem, a ratchet plate is rotatably stacked on a base plate, an operation shaft is disposed on a rotation center axis thereof, and the ratchet plate is opposed to the base plate. Is formed with a circular concave portion centering on the operation shaft, and an inner tooth is formed on the inner peripheral wall surface of the concave portion. Further, the concave portion is engaged with the inner tooth from the radial direction of the tip circle. A pole having a removable external tooth on the front end face side is disposed, while the base plate is provided with a guide protrusion for slidingly guiding the pole in the radial direction, and the space on the rear end face side of the pole is provided. A cam that is rotatable together with the operation shaft is arranged, and the biasing means presses the rear end face of the pole so that the external teeth of the pole mesh with the internal teeth of the ratchet plate. When the cam is rotated by the operation shaft against the urging force of the urging means, the release means forces the pawl toward the rotation center of the cam. A reclining device that moves the external teeth of the pole away from the internal teeth of the ratchet plate, wherein the cam is pressed against the rear end surface of the pole during rotation of the cam and the external teeth of the pole are An inclined cam surface that meshes with the inner teeth of the ratchet plate, and is positioned at least either on the front side or the rear side in the rotational direction of the cam by the biasing means with respect to the inclined cam surface, and the external teeth of the pole and the When meshed with the inner teeth of the ratchet plate, it faces the end of the rear end surface of the pole, and when a rotational load is applied from the ratchet plate to the pole, A support surface that supports the end portion of the rear end surface of the pole, and the support surface includes a first inclined surface that is inclined in the same direction as the inclined cam surface, and a second inclined surface that is inclined in a direction opposite to the inclined cam surface. The rear end surface end of the pole is provided with a first protrusion that can contact the first inclined surface and a second protrusion that can contact the second inclined surface. Is a reclining device.

  In this invention, the cam which has received the urging force of the urging means rotates in the direction in which the external teeth of the pole mesh with the internal teeth of the ratchet plate. Thereby, the inclined cam surface of the cam presses the rear end surface of the pole, and the pole moves in the radial direction in which the outer teeth mesh with the inner teeth of the ratchet plate. When the pole moves, the first protrusion, which is a part of the pole, also moves in the same direction and moves away from the rotation center of the cam, but when the first inclined surface of the cam is viewed from the first protrusion of the pole, the cam In response to the rotation of the cam, the first inclined surface of the cam approaches the first protrusion of the pole. For this reason, it can avoid that the clearance gap between the 1st protrusion part of a pole and the 1st inclined surface of a cam becomes large too much.

  At the time of locking when the external teeth of the pole and the internal teeth of the ratchet plate are engaged, if a load is applied from the ratchet plate to the pole due to a vehicle collision or the like, the pole is slightly inclined and the first protrusion is the first inclination of the cam The second projecting portion comes into contact with the second inclined surface of the cam. Therefore, the pole is supported by a total of three points, that is, the inclined cam surface and the first and second inclined surfaces of the cam.

  When a load is applied to the pole from the ratchet plate, a contact pressure acts on the contact surface between the first inclined surface of the cam and the first protrusion of the pole in the common normal direction on the contact surface. Therefore, by providing the first inclined surface inclined in the same direction as the inclined cam surface, the component force that pushes the cam back in the unlocking direction also acts on the cam.

  On the other hand, the cam is provided with a second inclined surface inclined in the opposite direction to the inclined cam surface, and the cam is rotated in the locking direction on the contact surface between the second inclined surface of the cam and the second protrusion of the pole. The component force to be applied acts on the cam. Therefore, the force that pushes back the cam in the unlocking direction caused by providing the first inclined surface is eliminated or reduced by the reverse force generated by the presence of the second inclined surface, and unlocked. Is not reached.

  Note that the second inclined surface and the second protrusion may not contact at the time of locking, but in this case, even if the cam is reversed, the second protrusion of the pole and the second inclined surface of the cam are in contact with each other. At that point, the cam will stop. This is because, when the second projecting portion of the pole and the second inclined surface of the cam come into contact with each other, a component force is generated to rotate the cam in the locking direction due to the presence of the second inclined surface.

  According to a second aspect of the present invention, in the reclining device according to the first aspect, the gap between the first inclined surface of the cam and the first protrusion of the pole is a meshing position between the outer teeth of the pole and the inner teeth of the ratchet plate. By selecting the shape of the inclined cam surface of the cam and the shape of the first inclined surface so as to be constant before and after, the gap between the first protrusion of the pole and the first inclined surface of the cam becomes excessively large. This is characterized by avoiding this.

  The invention according to claim 3 is the reclining device according to claim 1 or 2, wherein the pole and the cam are formed to have the same plate thickness and are arranged on the same plane of the base plate. A cam groove is formed on the surface, and the release means has a release plate that rotates together with the cam and forcibly moves the pole toward the rotation center side of the cam. It overlaps with the pole and the cam, and the other surface is arranged so as to be in sliding contact with the ratchet plate, and a protrusion engaging with the cam groove is formed at the rotating end portion, and the interaction between the cam groove and the protrusion The pole is forcibly moved to the rotation center side of the cam to reduce the cost of the release plate.

  According to the first aspect of the present invention, when the pole moves in the locking direction, the first protrusion, which is a part of the pole, also moves in the same direction and moves away from the rotation center of the cam. When the first inclined surface of the cam is viewed from above, the first inclined surface of the cam approaches the first protruding portion of the pole in accordance with the rotation of the cam. It can avoid that the clearance gap between 1 inclined surface becomes large too much. Therefore, the lock strength is not greatly reduced, and a high lock strength can be obtained stably.

  In addition, when a load is applied to the pole from the ratchet plate, a component force that pushes the cam back in the unlocking direction also acts on the cam. However, the cam has a second inclination inclined in the direction opposite to the inclined cam surface. A surface is also provided, whereby a component force for rotating the cam in the locking direction also acts on the cam. Therefore, the force that pushes back the cam in the unlocking direction caused by providing the first inclined surface is eliminated or reduced by the reverse force generated by the presence of the second inclined surface, and unlocked. In this respect, high lock strength can be obtained.

  According to the invention according to claim 2, since the gap between the first inclined surface of the cam and the first protrusion of the pole is constant before and after the meshing position between the external teeth of the pole and the internal teeth of the ratchet plate, Even if the meshing position deviates from the normal target position due to component tolerances, the lock strength does not vary greatly.

  According to the invention of claim 3, the protrusion that engages the cam groove is formed at the rotation end of the release plate, and the pawl is forced to the cam rotation center side by the interaction between the cam groove and the protrusion. Since the engaging part to the cam groove is formed integrally with the release plate by being configured to move, the structure of this part can be simplified and the release plate can be formed at low cost by press molding. Cost can be reduced.

  An embodiment of the present invention will be described with reference to FIGS. First, as shown in FIG. 3, in the reclining device of this embodiment, the base plate 100 is attached to the lower arm 201 on the seat cushion side, and the ratchet plate 130 is attached to the upper arm 202 on the seat back side.

  As shown in FIGS. 2 to 5, the disc-shaped ratchet plate 130 is fitted to the disc-shaped base plate 100, so that both are overlapped so as to be relatively rotatable. The cylindrical mounting bracket 205 wraps the base plate 100 and the ratchet plate 130 from the outside, and prohibits the ratchet plate 130 from separating from the base plate 100. Specifically, one end of the mounting bracket 205 is locked to the outer peripheral portion of the base plate 100, and the ratchet plate holding portion 205a on the other end side presses the ratchet plate 130 from the rotation center axis direction.

  A hole 101 and a hole 131 are formed at positions on the rotation center axis of the base plate 100 and the ratchet plate 130, and the operation shaft 120 is inserted into the hole 101 and the hole 131. As shown in FIGS. 3 and 5, a circular recess 132 centered on the operation shaft 120 is formed on the surface of the ratchet plate 130 facing the base plate 100, and the inner peripheral wall surface of the recess 132 has an inner wall. Teeth 133 are engraved.

  As shown in FIGS. 3 and 5, a concave portion 104 is formed on the surface of the base plate 100 facing the concave portion 132 of the ratchet plate 130. As shown in FIG. A pair of guide projections 105, 106 and a pair of guide projections 107, 108 project toward the plate 130.

  On the surface of the base plate 100 opposite to the ratchet plate 130 side, a plurality of coupling projections 100a for attaching to the lower arm 201 on the seat cushion side are arranged at equal intervals on the same circumference centered on the hole 101. Has been. On the surface of the ratchet plate 130 opposite to the base plate 100 side, a plurality of coupling protrusions 130 a for mounting on the seat back side upper arm 202 are arranged at equal intervals on the same circumference centered on the hole 131. Has been.

  The pole 140 has outer teeth 141 that can be engaged and disengaged from the radial direction of the tip circle on the inner teeth 133 of the ratchet plate 130 on the front end surface side, and as shown in FIG. 6, the guide surfaces of the guide protrusions 105 and 106 105a and 106a are slidably guided in the direction orthogonal to the rotation center axis of the ratchet plate 130, that is, in the radial direction of the tip circle of the internal teeth 133.

  The pole 150 has the same shape as the pole 140, is sandwiched between the guide surfaces 107a and 108a of the guide protrusions 107 and 108, is slidably guided in the radial direction of the tip circle of the inner tooth 133, and is on the front end surface side. The outer teeth 151 can be engaged with the inner teeth 133 of the ratchet plate 130.

  A cam 170 that can rotate together with the operation shaft 120 is disposed in the space on the rear end surfaces 146 and 156 side of the poles 140 and 150. That is, as shown in FIG. 3, a cross-sectional oval portion 123 is formed in the intermediate portion of the operation shaft 120, and this cross-sectional oval portion 123 is fitted in the oval hole 171 of the cam 170. As a result, the operation shaft 120 and the cam 170 are fitted in a state where relative rotation is impossible, and the cam 170 rotates together with the operation shaft 120.

  The poles 140 and 150 and the cam 170 are formed to have the same thickness and are disposed on the same plane of the base plate 100. The cam 170 has an inclined cam surface 174b for pressing the rear end surfaces 146 and 156 of the poles 140 and 150 when the cam 170 rotates to mesh the outer teeth 141 and 151 of the poles 140 and 150 with the inner teeth 133 of the ratchet plate 130. , 175b. In order to exert this function, the inclined cam surfaces 174b and 175b are inclined with respect to the contact between the inclined cam surfaces 174b and 175b and the rear end surfaces 146 and 156 of the poles 140 and 150 when the cam 170 rotates in the locking direction. The point is set in a direction away from the rotation center O of the cam 170. For example, if the inclined cam surface 175b in FIG.

  Further, the cam 170 is positioned on the front side in the rotation direction (counterclockwise direction in FIG. 7) of the cam 170 relative to the inclined cam surfaces 174b and 175b, and the outer teeth 141 and 151 of the poles 140 and 150 and the ratchet. When meshing with the internal teeth 133 of the plate 130, support surfaces 174a and 175a are provided at the ends of the rear end surfaces 146 and 156 of the poles 140 and 150 (front portions in the rotation direction when the cam 170 is locked) via a gap. ing. When the counterclockwise load in FIG. 7 is applied from the ratchet plate 130 to the poles 140 and 150 from the ratchet plate 130, the support surfaces 174a and 175a abut against the ends of the rear end surfaces 146 and 156 of the poles 140 and 150. And further tilting of the poles 140 and 150 is prohibited.

  Further, the cam 170 is located on the rear side in the rotation direction when the cam 170 is locked with respect to the inclined cam surfaces 174b and 175b, and between the outer teeth 141 and 151 of the poles 140 and 150 and the inner teeth 133 of the ratchet plate 130. Support surfaces 174c and 175c are provided so as to face the end portions of the rear end surfaces 146 and 156 of the poles 140 and 150 (the rear side portion in the rotation direction when the cam 170 is locked) when engaged. When the clockwise load in FIG. 7 is applied from the ratchet plate 130 to the poles 140 and 150 from the ratchet plate 130, the support surfaces 174c and 175c come into contact with the ends of the rear end surfaces 146 and 156 of the poles 140 and 150. It supports and prohibits further tilting of the poles 140 and 150.

  The detailed structure of the support surfaces 174a, 174c, 175a, 175c and their surroundings will be described using the support surface 175a as an example with reference to FIG. The support surface 175a includes a first inclined surface 175e having a length L1 inclined in the same direction as the inclined cam surface 175b, and a second inclined surface 175f having a length L2 inclined in the opposite direction to the inclined cam surface 175b. At the end portion of the rear end surface 156 of the 150, a first protrusion 150e that can contact the first inclined surface 175e and a second protrusion 150f that can contact the second inclined surface 175f are provided.

  Here, specific examples of the first inclined surface 175e and the second inclined surface 175f will be described. The first inclined surface 175e has an outer peripheral surface formed so that the distance between the part and the rotation center of the cam 170 becomes smaller as the part is in the rotation direction when locked. Conversely, the outer peripheral surface of the second inclined surface 175f is formed so that the distance between the part and the rotation center of the cam 170 increases as the part in the rotation direction when locked.

  Therefore, in the example in which the first inclined surface 175e and the second inclined surface 175f are formed using a part of the arc CT having the radius R passing through the boundary point M between the first inclined surface 175e and the second inclined surface 175f, The first inclined surface 175e above the point M is an inclined surface in a state where the arc CT is inclined counterclockwise (bent state) around the boundary point M, and the second inclined surface below the boundary point M. 175f is an inclined surface in a state where the arc is inclined clockwise around the boundary point M (bent state). The support surfaces 174a, 174c and 175c other than the support surface 175a are also provided with a first inclined surface and a second inclined surface with the same arrangement.

  Cam grooves 144 and 154 are formed on the surface of the poles 140 and 150 on the ratchet plate 130 side (in this embodiment, the cam grooves 144 and 154 are holes penetrating to the surface on the base plate 100 side). . The release plate 180 constituting the release means is disposed so that one surface thereof overlaps with the poles 140 and 150 and the cam 170 and the other surface is in sliding contact with the ratchet plate 130. A hole 181 through which the operation shaft 120 is inserted is formed in the central portion of the release plate 180.

  As shown in FIGS. 6 and 7, the cam 170 has protrusions 176 and 177 protruding toward the ratchet plate 130, and these protrusions 176 and 177 are formed at the edge of the hole 181 of the release plate 180. It is fitted in small slots 182 and 183 extending in the radial direction. For this reason, the cam 170 and the release plate 180 rotate in conjunction with each other.

  Further, as shown in FIGS. 3 and 6, projections 183 and 184 that engage with the cam grooves 144 and 154 are formed at the rotating end portion of the release plate 180 by press molding or the like. The cam grooves 144 and 154 are shaped so that when the release plate 180 rotates in the clockwise direction in FIG. 6, the pawls 140 and 150 are moved toward the rotation center side of the cam 170 by the interaction between the cam grooves 144 and 154 and the protrusions 183 and 184. It is set to move forcibly.

  As shown in FIGS. 6 and 7, the spiral springs 191 and 195 as urging means have inner ends hooked to the hooks 111 and 112 of the base plate 100 and outer ends hooked to the step portions 178 and 179 of the cam 170. The cam 170 is rotated and biased so that the cam 170 pushes the rear end surfaces 146 and 156 of the poles 140 and 150.

  The operation of the reclining device having the above configuration will be described. In the locked state, the urging force of the spiral springs 191 and 195 causes the cam 170 to push the rear end surfaces 146 and 156 of the poles 140 and 150, and the external teeth 141 and 151 of the poles 140 and 150 mesh with the internal teeth 133 of the ratchet plate 130. In this state, the rotation of the ratchet plate (seat back) 130 is prohibited.

  The movement at the time of shifting to the locked state will be described. The cam 170 that receives the urging force of the spiral springs 191 and 195 is a direction in which the external teeth 141 and 151 of the poles 140 and 150 are engaged with the internal teeth 133 of the ratchet plate 130. Rotate first. Accordingly, the inclined cam surfaces 174b and 175b of the cam 170 press the rear end surfaces 146 and 156 of the poles 140 and 150, and the outer teeth 141 and 151 of the poles 140 and 150 mesh with the inner teeth 133 of the ratchet plate 130. Move in the radial direction.

  The movement at this time will be described by taking the periphery of the support surface 175a of the cam 170 as an example. When the pole 150 moves, the first protrusion 150e, which is a part of the pole 150, also moves in the same direction and moves away from the rotation center O of the cam 170, but the first inclination of the cam 170 from the first protrusion 150e of the pole 150. When the surface 175e is viewed, the first inclined surface 175e of the cam 170 approaches the first protrusion 150e of the pole 150 as the cam 170 rotates.

  For this reason, it can avoid that the clearance gap between the 1st protrusion 150e of the pole 150 and the 1st inclined surface 175e of the cam 170 becomes large too much at the time of a lock | rock. Therefore, the lock strength is not greatly reduced, and a high lock strength can be obtained stably.

  In a locked state in which the external teeth 151 of the pole 150 and the internal teeth 133 of the ratchet plate 130 are engaged, when a load is applied from the ratchet plate 130 to the pole 150 due to a vehicle collision or the like, the pole 150 is slightly inclined and its first protrusion The portion 150e contacts the first inclined surface 175e of the cam 170, and the second protrusion 150f contacts the second inclined surface 175f of the cam 170. Therefore, the pole 150 is supported by a total of three points including the inclined cam surface 175b and the first and second inclined surfaces 175e and 175f of the cam 170.

  When a load is applied from the ratchet plate 130 to the pole 150, the contact pressure between the first inclined surface 175e of the cam 170 and the first protrusion 150e of the pole 150 causes a contact pressure in the common normal direction on the contact surface. Works. Therefore, by providing the first inclined surface 175e inclined in the same direction as the inclined cam surface 175b, the component force F1 (force that generates torque in the clockwise direction in FIG. 1) that pushes the cam 170 back in the unlocking direction. ) Also acts on the cam 170.

  On the other hand, the cam 170 is provided with a second inclined surface 175f inclined in the opposite direction to the inclined cam surface 175b. In the contact surface between the second inclined surface 175f of the cam 170 and the second protrusion 150f of the pole 150, A component force F <b> 2 (a force that generates a counterclockwise torque in FIG. 1) that attempts to rotate the cam 170 in the locking direction also acts on the cam 170. Therefore, the force F1 that is caused by providing the first inclined surface 175e and tries to push the cam 170 back in the unlocking direction is eliminated or reduced by the reverse force F2 generated by the presence of the second inclined surface 175f. Thus, the lock is not released, and a high lock strength can be obtained from this point.

  Note that there may be a case where the second inclined surface 175f of the cam 170 and the second protrusion 150f of the pole 150 do not come into contact with each other at the time of locking. The cam 170 stops when 150f and the second inclined surface 175f of the cam 170 come into contact with each other. This is because, when the second projecting portion 150f of the pole 150 and the second inclined surface 175f of the cam 170 are in contact with each other, the presence of the second inclined surface 175f causes a component force F2 to rotate the cam 170 in the locking direction. This is because it occurs.

  When the operation shaft 120 is rotated clockwise in FIG. 7 against the biasing force of the spiral springs 191 and 195 in the locked state, and the cam 170 is also rotated clockwise, the rear end surfaces of the poles 140 and 150 of the cam 170 are rotated. 146 and 156 are released, the projections 183 and 184 of the release plate 180 are in sliding contact with the inclined wall surfaces of the cam grooves 144 and 154 of the poles 140 and 150, and the external teeth 141 and 151 of the poles 140 and 150 are ratchet. The poles 140 and 150 retreat in a direction away from the inner teeth 133 of the plate 130, the meshing between the outer teeth 141 and 151 of the poles 140 and 150 and the inner teeth 133 of the ratchet plate 130 is released, and the ratchet plate (seat back) 130 can be tilted (unlocked state).

  When the seat back is tilted to a desired angle and the operation force to the operation shaft 120 is released, the cam 170 pushes the rear end surfaces 146 and 156 of the poles 140 and 150 by the urging force of the spiral springs 191 and 195, The 150 external teeth 141 and 151 mesh with the internal teeth 133 of the ratchet plate 130 again, and the ratchet plate (seat back) 130 returns to a state in which rotation is prohibited.

According to the configuration of such an embodiment, the following effects can be obtained.
(1) It can be avoided that the gap between the first protrusions of the poles 140 and 150 and the first inclined surface of the cam 170 becomes excessively large. Therefore, the lock strength is not greatly reduced, and a high lock strength can be obtained stably. In addition, when a load is applied from the ratchet plate 130 to the poles 140 and 150, a component force that pushes the cam 170 back in the unlocking direction also acts on the cam 170. However, the cam 170 is opposite to the inclined cam surface. A second inclined surface that is inclined in the direction is also provided, whereby a component force that causes the cam 170 to rotate in the locking direction also acts on the cam 170. Therefore, the force to push the cam 170 back in the unlocking direction caused by the provision of the first inclined surface is eliminated or reduced by the reverse force generated by the presence of the second inclined surface, and the lock is released. In this respect, a high lock strength can be obtained.

 (2) In particular, before and after the meshing position between the external teeth 141 and 151 of the poles 140 and 150 and the internal teeth 133 of the ratchet plate 130, the first inclined surface 175e of the cam 170 and the first protrusions of the poles 140 and 150 If the shape of the support surfaces (first inclined surface and second inclined surface) 174a, 174c, 175a, 175c and inclined cam surfaces 174b, 175b of the cam 170 is set so that the gap of the cam 170 is constant, the engagement will occur due to component tolerances. Even if the position deviates from the normal target position, the lock strength does not vary greatly.

 (3) Protrusions 183 and 184 that engage with the cam grooves 144 and 154 are formed at the rotation end of the release plate 180, and the pawls 140 and 150 are moved by the interaction between the cam grooves 144 and 154 and the protrusions 183 and 184. Since the engaging portion to the cam grooves 144 and 154 is formed integrally with the release plate 180 by forcibly moving the cam 170 toward the rotation center side, the configuration of this portion can be simplified, Since the release plate can be molded at low cost by press molding, the cost of the apparatus can be reduced.

 (4) The meshing positions of the external teeth 141 and 151 of the poles 140 and 150 and the internal teeth 133 of the ratchet plate 130 and the contact positions of the side walls of the cam grooves 144 and 154 and the projections 183 and 184 of the release plate 180 are as follows. Since the cams 170 are positioned on substantially the same plane with respect to the rotation center axis direction of the cam 170, when the pawls 140 and 150 are moved using the release plate 180 (unlock operation), the pawls 140 and 150 are rotated by the ratchet plate 130. Since no force is generated in the direction of rising from the plane, the unlocking feeling is good.

  The present invention is not limited to the above embodiment. For example, the shapes of the support surfaces (first inclined surface and second inclined surface) 174a, 174c, 175a, 175c and inclined cam surfaces 174b, 175b of the cam 170 are not limited to those in the above-described embodiment. In short, with respect to the inclined cam surface and the first inclined surface, these shapes are such that the outer peripheral surface is formed so that the distance between the portion and the rotation center of the cam becomes smaller as the portion in the rotation direction when locked. On the contrary, the second inclined surface may be any as long as the outer peripheral surface is formed so that the distance between the part and the rotation center of the cam becomes larger as the part in the rotation direction when locked. Because, with such a shape, even if the meshing position of the external teeth of the pole and the internal teeth of the ratchet plate deviates from the normal target position due to component tolerances, the gap between the two can be prevented from becoming excessively large. This is because the reverse rotation of the cam 170 can be avoided.

  Further, the support surfaces 174a, 174c, 175a, and 175c of the cam 170 are not configured by the first inclined surface and the second inclined surface as in the above-described embodiment, and only a part (for example, the support surfaces 174a and 175a) is the first. The first inclined surface and the second inclined surface may be configured, and the other supporting surfaces (for example, the supporting surfaces 174c and 175c) may be configured by a supporting surface having the same shape as the conventional one.

  Further, as a method of attaching the apparatus, the ratchet plate 130 may be attached to the seat cushion side, and the base plate 100 may be attached to the seat back side. The number of poles (140, 150) may be one or three or more, and the biasing of the cam 170 is not limited to the method using the spiral springs 191, 195.

It is an enlarged view of the principal part in FIG. It is a figure which shows the external appearance of the reclining apparatus of this example. FIG. 3 is a cross-sectional view taken along a cutting line CC in FIG. 2. FIG. 3 is a rear view of FIG. 2. FIG. 3 is a cross-sectional view taken along a cutting line DD in FIG. 2. It is sectional drawing in the cutting line EE of FIG. It is the figure which removed the release plate of FIG.

Explanation of symbols

100 Base plate 120 Operation shaft 130 Ratchet plate 133 Internal teeth 140, 150 Pole 141, 151 External teeth 144, 154 Cam groove 150e First protrusion 150f Second protrusion 170 Cam 174a, 174c, 175a, 175c Support surface 175e First inclination Surface 175f Second inclined surface 180 Release plate 183, 184 Projection

Claims (3)

A ratchet plate is rotatably overlapped with the base plate, an operation shaft is disposed on the rotation center axis thereof, and a circular recess centered on the operation shaft is formed on a surface of the ratchet plate facing the base plate. And an inner tooth is formed on the inner peripheral wall surface of the recess, and a pole having an outer tooth on the front end face side that can be engaged and disengaged from the radial direction of the tip circle of the inner tooth. On the other hand, the base plate is provided with a guide projection for slidingly guiding the pole in the radial direction, and a cam that is rotatable together with the operation shaft is arranged in the space on the rear end face side of the pole. The urging means urges the cam in a direction that presses the rear end surface of the pole and meshes the outer teeth of the pole with the inner teeth of the ratchet plate. When rotating the cam with the operation shaft against the urging force, the release means forcibly moves the pole toward the rotation center of the cam, and the external teeth of the pole are moved to the ratchet plate. A reclining device for separating from an internal tooth,
The cam has
An inclined cam surface that presses the rear end surface of the pole during rotation of the cam and meshes the outer teeth of the pole with the inner teeth of the ratchet plate;
It is located at least either on the front side or the rear side in the rotational direction of the cam by the biasing means with respect to the inclined cam surface, and at the time of meshing between the external teeth of the pole and the internal teeth of the ratchet plate Opposing to the end of the end surface, when a load in the rotational direction is applied to the pole from the ratchet plate, a support surface for supporting the end of the rear end surface of the pole is provided,
The support surface includes a first inclined surface that is inclined in the same direction as the inclined cam surface and a second inclined surface that is inclined in a direction opposite to the inclined cam surface. A reclining device provided with a first protrusion capable of contacting with one inclined surface and a second protrusion capable of contacting with the second inclined surface.   Inclination of the cam so that a gap between the first inclined surface of the cam and the first protrusion of the pole is constant before and after the meshing position of the outer teeth of the pole and the inner teeth of the ratchet plate. The reclining device according to claim 1, wherein the shape of the cam surface and the shape of the first inclined surface are selected. The pole and the cam are formed to have the same plate thickness, and are arranged on the same plane of the base plate, and further, a cam groove is formed on a surface of the pole on the ratchet plate side,
The release means includes a release plate that rotates together with the cam and forcibly moves the pawl toward the rotation center of the cam. The release plate has one surface that is connected to the pawl and the cam. Overlapping and arranged so that the other surface is in sliding contact with the ratchet plate, and at its rotating end, a protrusion is formed that engages with the cam groove, and by the interaction between the cam groove and the protrusion, The reclining device according to claim 1 or 2, wherein the pole is forcibly moved to the rotation center side of the cam.

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