JP2013132348A - Reclining device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a reclining device capable of preventing unintended unlocking.SOLUTION: A center-side end face 61c of a first locking gear 61 includes: a guide face 61d that, when an engagement degree between an external tooth 61a and an internal tooth 41 is low, comes into contact with a contact part 72a of a cam 70 and performs a guide; an AA 61e face that, when the engagement degree is high, is located in the side of the guide face 61d with respect to a surface with which the contact part 72a comes into contact and whose distance from the rotation center of the cam 70 is longer than the guide face 61d; and a connecting face 61f that connects the guide face 61d to a separation face 61e in a stepped manner and to which the contact part 72a comes into contact, when the engagement degree is changed.

Description

  The present invention relates to a reclining device that adjusts the tilt angle between a first member and a second member that are relatively tilted.

  Conventionally, a reclining device disclosed in Patent Document 1 below is known as a reclining device that adjusts the tilt angle between a relatively tilted first member and a second member. In this reclining device, a pair of base members fixed to the left and right sides of the seat cushion are formed with circular recesses, and the outer teeth of the inner tooth (lock gear) guided by the guide side walls are formed in the circular recesses. Upper and lower locking teeth are formed. Then, the outer teeth of both inner teeth mesh with the inner teeth of the rotating arm and the locking tooth portion of the base member, respectively, so that the locked state in which the rotation of the rotating arm with respect to the base member is restricted is maintained. .

  In this locked state, when an excessive impact force acts on the seat back in the locked state due to a collision or the like, the impact force acts as a rotational force that rotates the rotating arm in the unlocking direction. The contact area between the cam locking cam surface and the inner tooth locking cam surface even when this rotational force is transmitted inwardly pressing the inner tooth whose outer teeth mesh with the inner teeth. Are formed to be equal and wide, the inner tooth is prevented from moving inward, and the locked state is prevented from being released in accordance with the rotational force.

Japanese Patent Laid-Open No. 11-56511

  By the way, in the locked state, in the configuration in which the lock gear is simply pressed by the cam outward in the radial direction so that the external state of the lock gear meshes with the internal teeth of the gear plate, the lock gear and the cam When the contact surface is displaced, there is a problem in that the lock gear is not pressed by the cam, and the engagement between the lock gear and the inner teeth of the gear plate is released. Further, even if the lock gear (inner tooth) and the cam are configured as in the invention described in Patent Document 1, for example, if the number of lock gears increases and the rotational force in the unlocking direction with respect to the cam easily acts, There is a problem that it is difficult to prevent unlocking.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a reclining device that can prevent unintentional unlocking.

  In order to achieve the above object, the reclining device according to claim 1 according to the claims includes a tilt angle between the first member (11, 11a) and the second member (12, 12a) which are relatively tilted. A base plate (30) attached to the first member and an internal tooth attached to the second member and rotatably mounted on the base plate. And a gear plate (40) having (41) and external teeth (61a, 62a) which are guided and assembled so as to be movable in the radial direction by the guide portions (31, 32) provided on the base plate and mesh with the internal teeth. And a plurality of lock gears (61, 62), and contact portions (72a) capable of abutting on the center side end surfaces (61c) of the plurality of lock gears, respectively. The moving abutting portion abuts against the center-side end surface so that the movement of the lock gear in the radial direction can be controlled, and the cam is rotationally biased in the meshing direction for meshing the outer teeth with the inner teeth ( 70), and a guide surface that contacts and contacts the contact portion when the degree of meshing between the outer teeth and the inner teeth is low on a part of the center-side end surface of the plurality of lock gears (61d) is a surface that is located on the guide surface side from the surface that the contact portion contacts or faces when the degree of meshing is high, and the distance from the rotation center of the cam is greater than that of the guide surface. A long separation surface (61e), and a connection surface (61f) that connects the guide surface and the separation surface in a step shape and contacts the contact portion when the degree of meshing changes are formed. And

  The case where the degree of meshing of the external teeth and the internal teeth is low indicates that the external teeth mesh with the tip side of the internal teeth on the tip side, and the case where the degree of meshing of the external teeth and internal teeth is high The case where the teeth mesh with the inner teeth up to the root side is shown. That is, when the lock gear in the unlocked state moves outward in the radial direction, first, the lock gear moves further outward in the radial direction through a state where the engagement degree of the external teeth and the internal teeth is low on the distal end side. Then, after the state where the meshing degree with which the outer teeth and the inner teeth mesh with each other on the base side is high, the lock gear further moves outward in the radial direction, so that the meshing complete state where the meshing degree becomes the highest is achieved.

  According to a second aspect of the present invention, in the reclining device according to the first aspect, a gap is provided between the connecting surface and the abutting portion of the center side end surface when the meshing completion state in which the degree of meshing is the highest. It is formed so that it may be formed.

According to a third aspect of the present invention, in the reclining device according to the first or second aspect, the connecting surface has an inclination of the surface that causes the cam to be interposed via the contact portion when the contact surface is in contact with the contact portion. It is formed so as to generate a pressing force in the meshing direction.
In addition, the code | symbol in each said bracket | parenthesis shows the corresponding relationship with the specific means as described in each embodiment mentioned later.

  According to the first aspect of the present invention, the center-side end surface of a part of the plurality of lock gears has a guide surface that contacts and guides the contact portion when the degree of meshing of the external teeth and the internal teeth is low, and the degree of meshing. When the height is high, the contact portion is a surface positioned on the guide surface side from the contact or facing surface, and the distance between the rotation center of the cam and the guide surface is longer than the guide surface, and the guide surface and the separate surface are stepped. And a connecting surface with which the contact portion comes into contact when the degree of meshing changes.

  For this reason, when the outer teeth of the lock gear are engaged with the inner teeth of the gear plate, the position where the contact portion of the rotating cam contacts or faces the center end surface of the lock gear changes from the guide surface, the connecting surface, and the separation surface. At the same time, the degree of meshing changes. Then, the meshing of the external teeth and the internal teeth is completed in the meshing completion state where the meshing degree becomes the highest. On the other hand, when releasing the meshing state of the external teeth and the internal teeth, the position where the contact portion of the rotating cam contacts or faces the center side end surface of the lock gear changes with the separation surface, the connection surface, and the guide surface, The degree of meshing changes.

In the process of changing the degree of meshing, the contact portion comes into contact with the connection surface from the side of the separation surface whose distance from the rotation center of the cam is longer than the guide surface, so that the contact portion gets over the stepped connection surface. It becomes difficult to move to the guide surface side. As a result, even when turning force in the unlocking direction acts on the cam due to an impact or the like during locking, the abutting portion comes into contact with the connecting surface, so that the cam is difficult to rotate in the unlocking direction.
Therefore, unintentional unlocking can be prevented.

  In the invention of claim 2, the center-side end surface is formed such that a gap is provided between the connecting surface and the contact portion when the meshing completion state where the degree of meshing is the highest. In the configuration in which the center side end surface is formed so that the connecting surface and the contact portion contact each other without gaps when the engagement is completed, if the position of the connecting surface with respect to the center side end surface varies due to processing errors during manufacturing, the lock gear is more than necessary. In some cases, the outer teeth and the inner teeth are excessively loaded by pushing them outward in the radial direction. Therefore, by forming the center side end face so that a gap is provided between the connection surface and the contact portion when the engagement is completed, even if there is a manufacturing variation or the like regarding the position of the connection surface, the contact portion And the variation of the contact position between the central end surface and the center side end surface can be eliminated.

  In the invention of claim 3, the connecting surface is formed so that the inclination of the surface generates a pressing force in the meshing direction via the contact portion when the contact surface is in contact with the contact portion. At the time of contact between the contact portion and the connection surface, the cam can be made difficult to rotate in the unlocking direction by the pressing force via the connection surface.

It is a side view showing the composition outline of the vehicular seat where the reclining device concerning this embodiment is installed. It is sectional drawing of a reclining apparatus. It is sectional drawing by the cut surface equivalent to the 3-3 line shown in FIG. It is sectional drawing by the cut surface equivalent to the 4-4 line shown in FIG. It is explanatory drawing which shows the state which the contact part of the cam contact | abutted to the separation surface of the 1st lock gear. It is explanatory drawing which shows the state which the contact part of the cam contact | abutted to the connection surface of the 1st lock gear. FIGS. 7A and 7B are explanatory views showing an engaged state between the engaged portion and one side end portion of the spring member, FIG. 7A shows a locked state, and FIG. 7B shows a unlocked state.

Hereinafter, an embodiment of a reclining device according to the present invention will be described with reference to the drawings. FIG. 1 is a side view showing a schematic configuration of a vehicle seat 10 on which a reclining device 20 according to the present embodiment is installed.
As is well known, the vehicle seat 10 includes a seat cushion 11 and a seat back 12 as main components. The seat cushion 11 includes a seat bracket (lower bracket) 11a, and the seat back 12 includes a seat back bracket (upper side). Brackets) 12a are fixed.

  The lower bracket 11a and the upper bracket 12a are coupled to each other so as to be relatively rotatable by being fixed to the relatively rotating portions of the round reclining unit 21, respectively. Thereby, the tilt angle of the seat back 12 with respect to the seat cushion 11 can be adjusted. The seat cushion 11 and the lower bracket 11a correspond to an example of a “first member” described in the claims, and the seat back 12 and the upper bracket 12a include the “second member” described in the claims. It may correspond to an example of “members”.

  A reclining operation lever 23 is attached to the center shaft 22 at the center of the round reclining unit 21. A reclining device 20 is constituted by the round reclining unit 21, the center shaft 22 and the reclining operation lever 23. When the reclining operation lever 23 is pulled upward, the reclining device 20 is unlocked and the tilt angle of the seat back 12 can be adjusted. Here, the range of the angle A shown in FIG. 1 in which the seat back 12 is tilted backward is an inclination adjustment range in which the seat back 12 is locked at the angle position when the finger is released from the reclining operation lever 23. The range of angle B shown in FIG. 1 in which the back 12 is tilted forward is a free rotation range corresponding to a lock-free state in which the unlocked state continues even if the finger is released from the reclining operation lever 23. As can be seen from FIG. 1, the seat back 12 can be rotated from a forwardly tilted position in contact with the seat cushion 11 to a backwardly tilted position that becomes flat with the seat cushion 11. The structure of such a reclining device 20 will be described below.

  FIG. 2 is a cross-sectional view of the reclining device 20. FIG. 3 is a cross-sectional view taken along the line 3-3 shown in FIG. 4 is a cross-sectional view taken along the line 4-4 shown in FIG. In FIG. 2, the following description will be made with the left side of the drawing as one side in the axial direction and the right side of the drawing as the other side in the axial direction. 2, the center shaft 22 and the reclining operation lever 23 are not shown for convenience, and the gear plate 40 is shown only in the vicinity of the internal teeth 41 in FIG.

  As shown in FIG. 2, the round reclining unit 21 is configured so that the base plate 30 and the gear plate 40 are rotated relative to each other by assembling the cover bracket 50 by superimposing the substantially disc-shaped base plate 30 and the substantially bowl-shaped gear plate 40. It is configured to be held as possible and to prevent relative movement in the axial direction.

  A cavity (space) C is formed between the base plate 30 and the gear plate 40. In the cavity C, as shown in FIGS. 2 to 4, a total of four lock gears including a pair of first lock gears 61 and a pair of second lock gears 62, two movable guides 63, a central cam 70, A member for locking and unlocking such as a substantially arc-shaped spring member 80 and a substantially disc-shaped cam lever 90 is provided.

  The base plate 30 has a plurality of projections 30b formed on a side surface (hereinafter also referred to as a mounting surface 30a) on one side in the axial direction, and engages each projection 30b with an engagement hole (not shown) of the lower bracket 11a. By attaching it, it attaches to the said lower bracket 11a. As shown in FIG. 3, the base plate 30 is formed with four guide protrusions 31, 32, 31, 32 for guiding the lock gears 61, 62 in the radial direction on the side surface on the other side in the axial direction. ing.

  Here, as shown in FIG. 3, of the pair of guide surfaces for guiding the first lock gear 61, the guide surface of the guide convex portion 31 is one first guide surface 33 a, and the guide surface of the guide convex portion 32. Is the other first guide surface 33b. Of the pair of guide surfaces for guiding the second lock gear 62, the guide surface of the guide convex portion 32 is one second guide surface 34a, and the guide surface of the guide convex portion 31 is the other second guide surface 34b. And Of each guide surface, the other first guide surface 33b is formed with a recess 35 at the center in the longitudinal direction. The detailed shape of the recess 35 will be described later.

  Inner teeth 41 are formed on the inner peripheral surface of the annular outer edge of the gear plate 40 over the entire periphery. The gear plate 40 has a plurality of protrusions (not shown) formed on the back surface (the surface on the other side in the axial direction). By engaging these protrusions with the engagement holes (not shown) of the upper bracket 12a. And attached to the upper bracket 12a.

  As shown in FIG. 3, external teeth 61 a and 62 a that can mesh with the internal teeth 41 of the gear plate 40 are formed on the outer peripheral sides of the first lock gear 61 and the second lock gear 62. In addition, the lock gears 61 and 62 are respectively formed with protrusions 61b and 62b that protrude from the approximate center of the other surface in the axial direction to the other side in the axial direction. Both the first lock gears 61 are guided by the first guide surface 33a of the guide convex portion 31 and the movable guide 63 guided by the other first guide surface 33b of the guide convex portion 32, and slide only in the radial direction. Each is supported freely. Further, both the second lock gears 62 are supported by one second guide surface 34a of the guide convex portion 32 and the other second guide surface 34b of the guide convex portion 31 so as to be slidable only in the radial direction. ing.

  The first lock gear 61 is slidably contacted with a contact portion 72a of a cam 70 that rotates as will be described later at an end surface (hereinafter referred to as a center-side end surface) 61c on the center side thereof, so that the first lock gear 61 can move in the radial direction. It is formed to be controlled. The function of the center side end face 61c will be described in detail with reference to FIGS. FIG. 5 is an explanatory view showing a state in which the contact portion 72 a of the cam 70 is in contact with the separation surface 61 e of the first lock gear 61. FIG. 6 is an explanatory view showing a state in which the contact portion 72 a of the cam 70 is in contact with the connection surface 61 f of the first lock gear 61.

  As shown in FIG. 5, a guide surface 61d, a separation surface 61e, and a connection surface 61f are provided on the center side end surface 61c. The guide surface 61d has a contact portion 72a when the degree of meshing between the external teeth 61a and the internal teeth 41 of the gear plate 40 is low, that is, when the external teeth 61a mesh with the distal end side of the internal teeth 41 on the distal end side. It is formed so as to be brought into contact (sliding contact) with the guide.

  The separation surface 61e is a surface that is located on the guide surface 61d side from the surface that the contact portion 72a contacts or faces when the degree of meshing is high in the center side end surface 61c, and the distance from the rotation center of the cam 70 is the distance. It is formed to be longer than the guide surface 61d. For this reason, the degree of meshing when the abutting part 72a abuts on the separation surface 61e is lower than the degree of meshing when the abutting part 72a abuts on the guide surface 61d.

  The connection surface 61f connects the guide surface 61d and the separation surface 61e in a step shape, and is formed so that the contact portion 72a contacts when the degree of meshing changes. Further, the connecting surface 61f is provided at a position on the center side end surface 61c that faces the abutting portion 72a through a gap when the meshing completion state where the degree of meshing is the highest.

  In particular, as shown in FIG. 6, the connecting surface 61f has a slope of the surface so that the cam 70 generates a pressing force F1 in the meshing direction via the contact portion 72a when the contact surface 61f is in contact with the contact portion 72a. Is formed. That is, the pressing force F1 via the connecting surface 61f acts to deviate from the rotation center of the cam 70 so as to press the cam 70 in the meshing direction. For this reason, at the time of contact between the contact portion 72a and the connecting surface 61f, the cam 70 is rotated in the unlocking direction (the unlocking direction: in FIG. 5 and FIG. 6) by the pressing force F1 via the connecting surface 61f. (Clockwise) is difficult to rotate.

  Both movable guides 63 are formed in a wedge shape so that the width gradually decreases from one end toward the other end, and can contact both the first lock gear 61 and the other first guide surface 33b of the guide protrusion 32. Respectively. Each of these movable guides 63 is formed with a protrusion 63a that protrudes in a substantially cylindrical shape from the vicinity of the outer edge of the surface on the other side in the axial direction to the other side in the axial direction.

  Further, in both movable guides 63, concave portions 64 are respectively formed on the opposing surfaces of the other first guide surface 33b facing the concave portion 35 in the locked state. The recessed portion 64 and the recessed portion 35 constitute an engaged portion 65, and the one end 81 of the spring member 80 is engaged with the engaged portion 65.

  For this reason, as shown in FIG. 7A, the urging force F2 via the one side end 81 is applied to the urging force F2a against the concave portion 64 of the movable guide 63 and the urging force against the concave portion 35 of the other first guide surface 33b. F2b acts in a distributed manner, and the urging force F2a among these urging forces acts to urge the movable guide 63 radially inward (inward and central directions) of the base plate 30.

  Then, in accordance with the urging force F2a, both the movable guides 63 are always in a state of biting between the first lock gear 61 and the other first guide surface 33b, respectively, and the first lock gear 61 and the other first guide. The surface 33b and the movable guide 63 are brought into close contact with each other (tightly joined together), and the gap between the members disappears. Therefore, the backlash in the front-rear direction of the seat back 12 is eliminated.

  In particular, the concave portion 64 of the movable guide 63 is formed such that the urging surface 64a that receives the urging force F2a is inclined inward in the radial direction toward the other first guide surface 33b (angle θ1 in FIG. 7A). reference). Further, the recess 35 of the other first guide surface 33b is formed such that a biasing surface 35a that receives the biasing force F2b is inclined inward in the radial direction toward the movable guide 63 side (angle θ2 in FIG. 7A). reference).

  A plate-like cam 70 having a through hole 71 formed in the center is rotatably disposed at the center of the base plate 30. The cam 70 is formed with a cam surface 72 that contacts the end face on the center side of each lock gear 61, 62 on the outer peripheral surface, and two engagement holes 73 with which the other end 82 of the spring member 80 is engaged with the side face. Two columnar protrusions 74 protruding to the other side in the axial direction are formed. In particular, as shown in FIGS. 5 and 6, the cam surface 72 that contacts the center side end surface 61 c of both first lock gears 61 can contact (slidably contact) the guide surface 61 d, the separation surface 61 e, and the connecting surface 61 f. Is provided with a protruding contact portion 72a.

  As shown in FIG. 4, the cam 70 engages with the other end portions 82 of the two spring members 80, thereby causing the cam 70 to rotate in the locking direction (meshing direction: counterclockwise in FIGS. 3 and 4). It is strongly urged. As a result, the cam 70 abuts against the end face (61c) on the center side of the lock gears 61 and 62 at the cam surface 72, so that the lock gears 61 and 62 are urged by the urging forces in the lock rotation direction by the spring members 80. Is strongly biased radially outward (outward).

  The center shaft 22 is inserted into the through hole 71 of the cam 70, and the cam 70 is unlocked in the direction of unlocking against the urging force of the two spring members 80 by rotating the center shaft 22 (see FIGS. 3 and 3). 4 (clockwise at 4).

  As shown in FIG. 4, the cam lever 90 is provided with a through hole 91 that fits into both the projections 74 of the cam 70 and two cam holes 92 to 94, respectively, and with respect to the projection 63 a of the movable guide 63. Thus, two cam surfaces 95 that contact from the inside in the radial direction and urge (press) the outside in the radial direction when rotating in the unlocking rotation direction are provided on the outer peripheral edge. The cam lever 90 is fitted with the through holes 91 and the protrusions 74, the protrusions 61b are inserted into the cam holes 92, and the protrusions 62b are inserted into the cam holes 93, respectively. The lock gears 61 and 62 are assembled. As a result, the cam lever 90 is assembled to the cam 70 so as to rotate according to the rotation of the cam 70. The one end portion 81 of the spring member 80 is engaged with the engaged portion 65 exposed from each of the cam holes 94.

  As a result, when the cam lever 90 rotates together with the cam 70 in the unlock rotation direction, the inner peripheral edge of the cam hole 92 abuts against the protrusion 61b of the first lock gear 61, and the inner peripheral edge of the cam hole 93 corresponds to both the second lock gears 62. Each of the projections 62b comes into contact with each other. When the cam lever 90 further rotates in the unlocking rotation direction, the two protrusions 63a are urged by the cam surfaces 95, respectively, so that the two movable guides 63 are moved outward in the radial direction, respectively. The locked state of the lock gear 61 is released, and both the first lock gears 61 are movable in the radial direction. The protrusions 61b and 62b are urged radially inward by the inner peripheral edges of the cam holes 92 and 93, and the lock gears 61 and 62 move in conjunction with the radially inner side.

  The reclining device 20 configured as described above has a base bracket 30 in which the lock gears 61 and 62, the movable guide 63, the cam 70, and the like are disposed in the cavity C and are integrally assembled. 50 is integrated by ring caulking. As a result, the base plate 30 and the gear plate 40 are held so as to be relatively rotatable and the relative movement in the axial direction is suppressed.

  And the reclining operation lever 23 is assembled | attached with respect to the center shaft 22 inserted in the through-hole 71 of the cam 70, and the reclining apparatus 20 shown in FIG. 2 is completed. In the reclining device 20 configured as described above, the protrusions 30b of the base plate 30 are engaged with the engagement holes of the lower bracket 11a, and the protrusions of the gear plate 40 are engaged with the engagement holes of the upper bracket 12a. By combining, the seat cushion 11 and the seat back 12 are connected by the reclining device 20 so as to be capable of relative tilting. The base plate 30 may be attached to the upper bracket 12a and the gear plate 40 may be attached to the lower bracket 11a.

An unlocked state and a locked state of the reclining device 20 according to this embodiment configured as described above will be described below.
(Unlocked)
First, the unlocked state in the reclining device 20 will be described.
When the occupant releases the lock to adjust the tilt angle of the seat back 12, the reclining operation lever 23 is operated to rotate the center shaft 22 in the unlocking rotation direction. Then, according to this operating force, the cam 70 and the cam lever 90 rotate in the unlock rotation direction against the urging force of both spring members 80 together with the center shaft 22.

  When the cam 70 is rotated in the unlocking rotation direction, the contact between the cam surface 72 of the cam 70 and the center side end surfaces of the lock gears 61 and 62 is released, and the lock gears 61 and 62 are radiused. The biasing force by the cam 70 biasing outward in the direction is released. As a result, the lock gears 61 and 62 can move inward in the radial direction, and the engagement between the inner teeth 41 of the gear plate 40 and the outer teeth 61a and 62a of the lock gears 61 and 62 can be released.

  Thus, when the meshing state of the external teeth 61 a of the first lock gear 61 and the internal teeth 41 of the gear plate 40 is released, the contact portion 72 a of the rotating cam 70 contacts the center side end surface 61 c of the first lock gear 61. The positions to be changed are the separation surface 61e, the connection surface 61f, and the guide surface 61d, and the meshing degree is changed. Specifically, when the cam 70 rotates in the unlocking rotation direction from the engagement completion state where the engagement degree becomes the highest, the engagement degree gradually decreases, and after the contact portion 72a is slidably contacted with the separation surface 61e ( 5) and abuts on the connecting surface 61f (see FIG. 6). Then, when the contact portion 72a gets over the connecting surface 61f from this contact state, the degree of meshing once slightly increases, and the contact portion 72a slides on the guide surface 61d. Further, when the cam 70 further rotates in the unlocking rotation direction, the degree of engagement gradually decreases while the contact portion 72a slides on the guide surface 61d, and the engagement between the outer teeth 61a and the inner teeth 41 is released. Is done.

  Further, as the cam lever 90 rotates in the unlock rotation direction, the protrusion 63a of the movable guide 63 is urged by the cam surface 95 and moves outward in the radial direction. At this time, the movable guide 63 moves outward in the radial direction against the urging force F <b> 2 a acting by the one end 81 of the spring member 80 engaged with the recess 64. That is, in order to move the movable guide 63 radially outward against the urging force F2a of the spring member 80, an operation force F3 corresponding to the operation of the operation lever 23 shown in FIG. .

The operating force F3 will be described in detail with reference to FIG.
In the locked state, as shown in FIG. 7A, the urging force F2 of the spring member 80 is applied to the urging force F2a on the urging surface 64a of the movable guide 63 and the urging surface 35a of the other first guide surface 33b. The urging force F2b acts in a distributed manner. When the operation force F3 is applied to the movable guide 63, the movable guide 63 moves outward in the radial direction against the urging force F2a acting via the one end 81. At this time, the force required as the operating force F3 is a force corresponding to the urging force F2a acting in a distributed manner, so that the urging force F2 of the spring member 80 is all applied to the movable guide 63 without being dispersed. Thus, the operating force F3 for moving the movable guide 63 outward in the radial direction can be reduced.

  In particular, the urging surface 64a on which the urging force F2a acts is formed so as to be inclined inward in the radial direction toward the other first guide surface 33b side (see the angle θ1 in FIG. 7A). Is moved outward in the radial direction, the one side end portion 81 pressed against the urging surface 64a moves along the urging surface 64a to the concave portion 35 side of the other first guide surface 33b. As a result, the biasing force F2a via the one side end portion 81 acts on the concave portion 35 of the other first guide surface 33b more than the concave portion 64 of the movable guide 63, so that the movable guide 63 resists the biasing force F2a. As a result, the operating force F3 required to move outward in the radial direction can be further reduced.

  As described above, when the movable guides 63 move outward in the radial direction so that the engagement state of the first lock gear 61 by the movable guides 63 is released, the lock gears 61 move inward in the radial direction. Is possible. Then, when the cam lever 90 further rotates in the unlock rotation direction together with the cam 70, the inner peripheral edges of the cam holes 92 and 93 of the cam lever 90 come into contact with the protrusions 61b and 62b of the lock gears 61 and 62, respectively. By positively moving the lock gears 61 and 62 radially inward, the meshing between the inner teeth 41 and the outer teeth 61a and 62a is released.

  As described above, when the meshing between the inner teeth 41 and the outer teeth 61a and 62a is released, the rotation of the gear plate 40 becomes free and the round reclining unit 21 is unlocked. When the round reclining unit 21 is unlocked, the reclining device 20 is unlocked, and when the seat back 12 is tilted backward, the tilt angle of the seat back 12 can be freely adjusted ( (See angle A in FIG. 1).

(Locked state)
Next, the locked state in the reclining device 20 will be described.
When the adjustment of the inclination angle of the seat back 12 by the occupant is finished, the reclining operation lever 23 is loosened, so that the cam 70 and the cam lever 90 are rotated in the lock rotation direction by the urging force of both spring members 80.

  When the cam surface 72 of the rotating cam 70 comes into contact with the center-side end surfaces of the lock gears 61 and 62, the lock gears 61 and 62 are urged radially outward. Accordingly, the outer teeth 61 a and 62 a of the lock gears 61 and 62 move radially outward so as to mesh with the inner teeth 41 of the gear plate 40. Further, by releasing the contact between the cam surface 95 of the rotating cam lever 90 and the protrusions 63a of both movable guides 63, the biasing force of the spring member 80 acting on the recess 64 via the one side end 81 is provided. As a result, both movable guides 63 move radially inward.

  Then, the outer teeth 61a and 62a of the lock gears 61 and 62 mesh with the inner teeth 41 of the gear plate 40, and both movable guides 63 bite between the first lock gear 61 and the other first guide surface 33b. By being in the tight state, the rotation of the gear plate 40 is limited, and the reclining device 20 is in the locked state.

  As described above, when the outer teeth 61 a of the first lock gear 61 are engaged with the inner teeth 41 of the gear plate 40, the position where the contact portion 72 a of the rotating cam 70 contacts the center side end surface 61 c of the first lock gear 61 is determined. The guide surface 61d, the connecting surface 61f, and the separation surface 61e change, and the degree of meshing changes. Specifically, when the cam 70 rotates in the lock rotation direction from the state where the outer teeth 61a and the inner teeth 41 are not engaged, the degree of engagement gradually increases, and the contact portion 72a is in sliding contact with the guide surface 61d. Then, when the connection surface 61f is crossed, the degree of meshing once becomes slightly lower, and the contact portion 72a comes into sliding contact with the separation surface 61e (see FIG. 5). Further, the cam 70 further rotates in the lock rotation direction, so that the degree of meshing gradually increases while the contact portion 72a is in sliding contact with the separation surface 61e (see FIG. 6), and the first lock gear 61 is located on the center side. By being pushed up by the abutting portion 72a that rotates on the end surface 61c, the meshing of the external teeth 61a and the internal teeth 41 is completed, and the meshing complete state in which the meshing degree becomes the highest is achieved.

  In such a meshing completion state (locked state), when a rotational force in the unlocking rotation direction acts on the cam 70 due to an impact or the like, the contact portion 72a is slightly rotated while being in sliding contact with the separation surface 61e. It contacts the connecting surface 61f. Due to the contact between the contact portion 72a and the connecting surface 61f, the cam 70 is difficult to rotate in the unlock rotation direction. In particular, the connecting surface 61f is formed so that the inclination of the surface generates a pressing force F1 in the meshing direction of the cam 70 via the contact portion 72a when the contact surface 61f contacts the contact portion 72a (see FIG. When the contact portion 72a and the connecting surface 61f are in contact with each other, the cam 70 is difficult to rotate in the unlock rotation direction due to the pressing force F1. In this way, the cam 70 is difficult to rotate in the unlock rotation direction, so that unintended unlocking can be prevented.

  As described above, in the reclining device 20 according to the present embodiment, the center-side end surface 61c of the first lock gear 61 has a contact with the contact portion 72a of the cam 70 when the degree of meshing between the external teeth 61a and the internal teeth 41 is low. The guide surface 61d that is in contact with the guide surface and a surface that is located on the guide surface 61d side from the surface that the contact portion 72a contacts when the degree of meshing is high, and the distance from the rotation center of the cam 70 is larger than that of the guide surface 61d. A long AA 61e surface, a guide surface 61d and a separation surface 61e are connected in a step shape, and a connection surface 61f is formed in which the contact portion 72a contacts when the degree of meshing changes.

For this reason, in the process of changing the degree of engagement when releasing the lock, the contact portion 72a contacts the connecting surface 61f from the side of the separation surface 61e whose distance from the rotation center of the cam 70 is longer than the guide surface 61d. Thus, the contact portion 72a gets over the step-like connecting surface 61f and is difficult to move to the guide surface 61d side. As a result, even if a rotational force in the unlocking rotation direction (unlocking direction) acts on the cam 70 due to an impact or the like during locking, the cam 70 is unlocked by the contact portion 72a contacting the connecting surface 61f. It becomes difficult to turn in the turning direction.
Therefore, unintentional unlocking can be prevented.

  Further, the center-side end surface 61c is formed such that a gap is provided between the coupling surface 61f and the abutting portion 72a when the meshing completion state where the meshing degree is the highest is achieved. In the configuration in which the center-side end surface 61c is formed so that the connecting surface 61f and the contact portion 72a contact each other without gaps when the meshing is completed, the position of the connecting surface 61f with respect to the center-side end surface 61c varies due to processing errors during manufacturing. In some cases, the first lock gear 61 is pushed outward in the radial direction more than necessary, and an excessive load acts on the outer teeth 61 a and the inner teeth 41. Therefore, by forming the center side end surface 61c so that a gap is provided between the connection surface 61f and the contact portion 72a when the engagement is completed, even if there is a manufacturing variation or the like regarding the position of the connection surface 61f. The variation in the contact position between the contact portion 72a and the center side end surface 61c can be eliminated.

  Furthermore, the connecting surface 61f is formed so that the inclination of the surface generates a pressing force F1 in the meshing direction of the cam 70 via the contact portion 72a when the contact surface 61a is in contact with the contact portion 72a. At the time of contact between the contact portion 72a and the connecting surface 61f, the cam 70 can be made difficult to rotate in the unlocking rotation direction by the pressing force F1 via the connecting surface 61f.

In addition, this invention is not limited to the said embodiment, You may actualize as follows.
(1) The separation surface 61e may be formed so that the contact portion 72a faces through a predetermined gap without contacting.

(2) The number of lock gears guided by the guide protrusions 31 and 32 of the base plate 30 is not limited to the four first lock gears 61 and the two second lock gears 62, and may be three or five or more, for example. There may be. In this case, at least a part of the center-side end surface of each lock gear is formed as the above-described center-side end surface 61c, and the cam surface 72 of the cam 70 that is in sliding contact (contact) with the center-side end surface 61c is described above. By forming the contact portion 72a, it is possible to make it difficult for the cam 70 to rotate in the unlock rotation direction. In particular, the center-side end surface of the pair of lock gears opposed via the cam 70 is formed as the above-described center-side end surface 61c, so that the cam 70 can be made difficult to rotate in the unlock rotation direction.

DESCRIPTION OF SYMBOLS 10 ... Vehicle seat 11 ... Seat cushion (1st member)
11a: Lower bracket (first member)
12 ... Seat back (second member)
12a ... Upper bracket (second member)
20 ... Reclining device 30 ... Base plate 31, 32 ... Guide convex part (guide part)
40 ... Gear plate 41 ... Internal teeth 61 ... First lock gear 61a ... External teeth 61c ... Center side end surface 61d ... Guide surface 61e ... Separation surface 61f ... Connecting surface 62 ... Second lock gear 62a ... External teeth 70 ... Cam 72 ... Cam surface 72a ... contact part

Claims (3)

A reclining device that adjusts a tilt angle between a first member and a second member that tilt relatively,
A base plate attached to the first member;
A gear plate attached to the second member and assembled to be rotatable relative to the base plate and having internal teeth;
A plurality of lock gears having outer teeth which are guided and assembled so as to be movable in a radial direction by a guide portion provided on the base plate, and have outer teeth which can mesh with the inner teeth;
The movement of the lock gear in the radial direction can be controlled by the contact portions that have contact portions that can contact the center-side end surfaces of the plurality of lock gears, and the moving contact portions contact the center-side end surfaces; A rotationally biased cam that meshes the outer teeth with the inner teeth,
In the center side end surface of a part of the plurality of lock gears,
A guide surface that contacts and contacts the contact portion when the degree of meshing between the external teeth and the internal teeth is low;
When the meshing degree is high, the abutting portion is a surface located on the guide surface side from the surface that abuts or opposes, and a separation surface whose distance from the rotation center of the cam is longer than the guide surface;
A reclining device, wherein the guide surface and the separation surface are connected in a step shape, and a connection surface is formed on which the contact portion comes into contact when the degree of meshing changes.   The said center side end surface is formed so that a clearance gap may be provided between the said connection surface and the said contact part at the time of the meshing completion state in which the said meshing degree becomes the highest. Reclining device.   The connecting surface is formed such that an inclination of the surface generates a pressing force for the cam in the meshing direction via the contact portion when the contact surface is in contact with the contact portion. Item 3. A reclining device according to item 1 or 2.

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