JP2013212328A - Reduction gear mechanism - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a reduction gear mechanism having a simple structure and excellent in response to operation and stability in operation.SOLUTION: A wedge member formed of two overlapped wedge members, is inserted between a circular hole of large diameter and a cylindrical portion of small diameter which are formed in an externally toothed gear and an internally toothed gear, respectively, the gears provided between a supporting member and a rotation member. The two overlapped wedge members each include an inside abutment portion making slide contact with the outer peripheral surface of the cylindrical portion, and an outer abutment portion making slide contact with the inner peripheral surface of the circular hole, in a manner to have different circumferential positions, wherein the inside and outside abutment portions are adjacent to each other in a radial direction, connection portions between the inside and outside abutment portions are intersected, and the two overlapped wedge members are assembled. The two overlapped wedge members are moved to be urged in the forward and reverse rotational directions by an urging member, and the inside and outside abutment portions are brought into press-contact with the outer peripheral surface of the cylindrical portion and the inner peripheral surface of the circular hole, respectively, to constantly hold a relative eccentric position of the externally-toothed gear and the internally-toothed gear. The two overlapped wedge members are operated by a driving device to eccentrically rotate the externally-toothed gear and the internally-toothed gear with the change in meshing position.

Description

  The present invention relates to a reduction gear mechanism used in a movable device mounted on a vehicle or the like.

  Equipped with an external gear with external teeth on the outer periphery and an internal gear with internal teeth with more teeth than the external teeth on the inner periphery, and can rotate coaxially with the external gear or internal gear A reduction gear mechanism of a type that changes the meshing position of the external teeth and the internal teeth while eccentrically moving either the external gear or the internal gear about the other shaft by the wedge release member fitted to Are known. This type of reduction gear mechanism is used in, for example, a reclining device that adjusts the angle of a seat back as in Patent Documents 1 to 3, and is fixed to a lower arm and a seat back that are fixed to a seat cushion. An external gear is fixed to one of the pivot portions of the upper arm, and an internal gear is fixed to the other.

  More specifically, a circular hole is formed in one of the shaft portions of the external gear and the internal gear, and the other shaft portion has a cylindrical portion having an outer peripheral surface smaller in diameter than the inner peripheral surface of the circular hole. In the state where the external gear and the internal gear mesh with each other, the center of the cylindrical portion is positioned eccentric to the center of the circular hole. As a configuration for maintaining this eccentric state, a configuration in which a pair of wedge-shaped members having a symmetrical shape between a circular hole and a cylindrical portion is inserted while being spaced apart in the circumferential direction is known (Patent Document 1). The pair of wedge-shaped members are urged in a direction in which the wedge is driven between the circular hole and the cylindrical portion, and the relative movement between the external gear and the internal gear is normally prohibited by the wedge effect. On the other hand, when the pair of wedge-shaped members are moved around the cylindrical portion by the rotation operation of the wedge release member having the center of the cylindrical portion as the rotation axis, the external gear and the internal gear are mutually moved by the pressing force of the pair of wedge-shaped members. Eccentric motion is performed to change the meshing position of the outer teeth and inner teeth while changing the center position. When applied to the reclining device as described above, the angle of the upper arm with respect to the lower arm changes due to the eccentric movement of the external gear and the internal gear.

  In the invention described in Patent Document 2, each of the pair of wedge-shaped members spaced apart in the circumferential direction is provided on the inner peripheral surface of the circular hole and the wedge piece on the inner diameter side contacting the outer peripheral surface of the cylindrical portion (collar). It is divided into a wedge piece on the outer diameter side that abuts.

  In the invention described in Patent Document 3, the wedge-shaped members are not arranged apart from each other in the circumferential direction as in Patent Document 1 and Patent Document 2, but an eccentric ring segment is configured by overlapping two wedge segments in the radial direction. ing.

JP 2006-204891 A JP 2007-275279 A Japanese Patent No. 3647398

  In the configuration of Patent Document 1, when one of the pair of wedge-shaped members that are separated in the circumferential direction is pressed by the wedge-release member when the lock state is released, the force is transmitted to the other wedge-shaped member. This is performed through a biasing member that biases the wedge-shaped member in the separation direction, or when one pressed wedge-shaped member directly contacts the other wedge-shaped member. Which mode is selected depends on various factors such as the magnitude relationship between the urging force of the urging member and the pressing force by the wedge releasing member and the magnitude of the frictional resistance acting on each wedge-shaped member. This is the transmission of force through elastic coupling by the members, and the latter is the transmission of force by the contact of the wedge-shaped members that are separated in the circumferential direction. Therefore, in either case, the other wedge-shaped member moves after one wedge-shaped member is pressed. There is a risk that a slight time lag may occur before the process is performed. The configuration of Patent Document 2 is different from Patent Document 1 in that each wedge-shaped member is divided into wedge pieces on the inner diameter side and the outer diameter side, but there is a similar problem.

  On the other hand, in the configuration of Patent Document 3, two wedge segments overlap each other in the radial direction, and a time lag in operation hardly occurs between the wedge segments. However, since the abutment (pressing) portion of the wedge release member with respect to the two wedge segments is asymmetric, there is a possibility that a difference occurs in the drive load and the response of the operation depending on the rotation direction.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a reduction gear mechanism that has a simple configuration and is excellent in responsiveness during operation and stability in operation.

  In the present invention, an external gear having external teeth on the outer periphery is provided on one of the support member and a rotating member that can rotate relative to the support member, and the other has more teeth than the external teeth of the external gear. An internal gear having internal teeth is provided, and one of the external gear and the internal gear is provided with a large-diameter circular hole and a cylindrical portion having a smaller diameter than the circular hole on the other axis. An eccentric holding means that is inserted between the inner peripheral surface and the outer peripheral surface of the cylindrical portion and keeps the external gear and the internal gear engaged in an eccentric state with different center positions, and an eccentric holding means by rotation with respect to the cylindrical portion. A reduction gear mechanism that includes an external gear and a driving unit that causes the external gear and the internal gear to perform eccentric rotation accompanying a change in meshing position is characterized by having the following configuration. The eccentric holding means includes two overlapping wedge members and a biasing member that biases the two overlapping wedge members. Each of the two overlapping wedge members has a circumferential position that is different between an inner contact portion that is slidably contacted with the outer peripheral surface of the cylindrical portion and an outer contact portion that is slidably contacted with the inner peripheral surface of the circular hole. The inner peripheral surface of the circular hole is configured such that the inner contact portion and the outer contact portion are adjacent to each other in the radial direction, and the connection portion between the inner contact portion and the outer contact portion crosses each other. And between the outer peripheral surface of the cylindrical portion. The urging member urges the two overlapping wedge members to move in the forward and reverse rotational directions, and the inner contact portion and the outer contact portion of the two overlap wedge members are respectively connected to the outer peripheral surface of the cylindrical portion and the circular hole. And the relative eccentric positions of the external gear and the internal gear are kept constant.

  The inner contact portions of the two overlapping wedge members each have an inner sliding contact surface that is a curved surface that is slidably contacted with the outer peripheral surface of the cylindrical portion on the inner peripheral side. The outer peripheral interlocking surface, which is a curved surface with a small curvature, may be provided on the outer peripheral side, and the radial width from the inner sliding contact surface to the outer peripheral interlocking surface may be reduced as it moves away from the connecting portion toward the distal end side. Each outer contact portion of the two overlapping wedge members has an outer sliding contact surface on the outer peripheral side, which is a curved surface that comes into contact with the inner peripheral surface of the circular hole so as to be slidable. Also, the inner peripheral interlocking surface, which is a curved surface with a large curvature, is provided on the inner peripheral side, and the radial width from the outer sliding contact surface to the inner peripheral interlocking surface increases as the distance from the connecting portion advances toward the distal end side. Good. When the outer peripheral interlocking surface and the inner peripheral interlocking surface are in contact with each other, a rotational force acting on one overlapping wedge member can be transmitted to the other overlapping wedge member.

  The connecting portions of the two overlapping wedge members may each have a concave portion facing in the direction along the rotation axis of the external gear and the internal gear, and the two overlapping wedge members may be combined by fitting the concave portions to each other.

  The two overlapped wedge members preferably change the eccentric amount of the external gear and the internal gear by relative movement in the circumferential direction that changes the crossing position of the connecting portions. Thereby, it is possible to cope with variations in the sizes of the outer peripheral surface of the cylindrical portion and the inner peripheral surface of the circular hole.

  The urging member includes a torsion spring having an annular coil portion and a pair of spring end portions that project from the coil portion and engage with two spring hook portions formed on one and the other of the two overlapping wedge members. Can be configured.

  The driving means includes a shaft portion that is rotatably inserted into the cylindrical portion of the external gear or the internal gear, and a pressing portion that can abut against the circumferential end surfaces of the inner abutment portions of the two overlapping wedge members. And a rotation transmission member having Or it is also possible to make the object which the press part of this rotation transmission member contact | abuts into the circumferential direction end surface of an outer side contact part instead of the circumferential direction end surface of each inner side contact part of two overlapping wedge members. Such selection of the contact portion of the rotation transmission member can be realized by appropriately changing the circumferential lengths of the inner contact portion and the outer contact portion in each overlapping wedge member.

  According to the above-described reduction gear mechanism of the present invention, when one of the two overlapping wedge members is pressed, a pressing force is applied to the other without delay, so that the responsiveness during operation is excellent. In addition, in a state where the two overlapping wedge members are combined, the wedge shapes on both sides sandwiching the connecting portion of each overlapping wedge member can be made symmetric, so there is no variation in driving load due to the difference in the rotation direction, etc. Excellent operational stability can be obtained. Since the eccentric holding means provided between the external gear and the internal gear is composed of two overlapping wedge members and a biasing member, the number of parts does not increase as compared with the conventional product, and it is simple. The configuration can be obtained at a low cost.

1 is an exploded perspective view of a reduction gear mechanism of a first embodiment to which the present invention is applied. FIG. 3 is a front view of the reduction gear mechanism according to the first embodiment viewed in a direction along the rotation axis of the gear. FIG. 3 is a front view of the reduction gear mechanism of the first embodiment shown with the holding member, wedge releasing member, and biasing spring removed. It is sectional drawing which follows the A1-A1 line | wire of FIG. It is sectional drawing which follows the B1-B1 line | wire of FIG. It is a front view of the 1st wedge member and the 2nd wedge member which constitute the reduction gear mechanism of a 1st embodiment. In the reduction gear mechanism of the first embodiment, the change in the eccentric amount of the inner guide surface on the external gear side and the outer guide surface on the internal gear side due to the change in the intersecting position of the first wedge member and the second wedge member ( It is the front view shown in each aspect of A), (B), (C). It is a disassembled perspective view of the reduction gear mechanism of 2nd Embodiment. It is the front view which looked at the reduction gear mechanism of 2nd Embodiment in the direction in alignment with the rotating shaft of a gearwheel. It is a front view of the reduction gear mechanism of 2nd Embodiment shown by removing a holding member, a wedge release member, and an urging spring. It is sectional drawing which follows the A2-A2 line | wire of FIG. It is sectional drawing which follows the B2-B2 line | wire of FIG. It is a front view of the 1st wedge member and the 2nd wedge member which constitute the reduction gear mechanism of a 2nd embodiment.

  A reduction gear mechanism 10 according to a first embodiment to which the present invention is applied will be described with reference to FIGS. The reduction gear mechanism 10 can be mounted on any movable device, and an example applied to a vehicle seat reclining device will be described below. The external gear 11 constituting the reduction gear mechanism 10 is fixed to a lower arm (support member) that is fixed to a seat cushion frame (not shown), and the internal gear 12 is fixed to a seat back frame (not shown). It is fixed to the upper arm (rotating member).

  A plurality of fixed protrusions 11a are provided on the side surface of the external gear 11 having a disk shape at predetermined intervals in the circumferential direction. The external gear 11 is positioned by fitting the fixed projection 11a into a fitting hole formed in the lower arm, and is welded to the lower arm after positioning. External teeth 11b are formed on the outer peripheral surface of the external gear 11, and a cylindrical portion 11c is formed at the center by burring. The outer peripheral surface of the cylindrical portion 11c is an inner guide surface S1 having a circular cross section, and the inner peripheral surface of the cylindrical portion 11c is a shaft hole D having a circular cross section concentric with the inner guide surface S1. An annular recess 11d is formed in a region between the cylindrical portion 11c and the external teeth 11b.

  A plurality of fixed protrusions 12 a are provided at predetermined intervals in the circumferential direction on the side surface of the internal gear 12 having a disk shape larger in diameter than the external gear 11. The internal gear 12 is positioned by fitting the fixed protrusion 12a into a fitting hole formed in the upper arm, and is welded to the upper arm after positioning. The internal gear 12 is engraved with internal teeth 12b that are inscribed with the external teeth 11b and that have at least one more tooth than the external teeth 11b of the external gear 11. A cylindrical rib-shaped portion 12c having a circular hole inside is formed at the center of the internal gear 12, and the inner peripheral surface of the cylindrical rib-shaped portion 12c (circular hole) is an outer guide surface S2 having a circular cross section. An annular recess 12d is formed in a region between the cylindrical rib-like portion 12c and the internal teeth 12b. An annular back side recess 12e is formed on the back side of the cylindrical rib portion 12c.

  As shown in FIGS. 4 and 5, the external gear 11 and the internal gear 12 are arranged so that the concave portions 11 d and 12 d face each other and the external gear 11 is accommodated in the concave portion 12 d of the internal gear 12. Combined. In this combined state, one side surface of the external gear 11 faces the bottom surface of the concave portion 12, the end surface of the cylindrical rib-like portion 12c faces the bottom surface of the concave portion 11d, and the cylindrical portion 11c enters the cylindrical rib-like portion 12c. Inserted. The outer guide surface S2 on the inner peripheral side of the cylindrical rib-shaped portion 12c is larger in diameter than the inner guide surface S1 on the outer peripheral side of the cylindrical portion 11c, and a predetermined gap is provided in the radial direction between the inner guide surface S1 and the outer guide surface S2. It is ensured and the relative movement in the radial direction of the internal gear 12 with respect to the external gear 11 is allowed. In addition, as described above, the number of teeth of the inner teeth 12b is set larger than that of the outer teeth 11b. Therefore, when the external gear 11 and the internal gear 12 are combined by meshing the internal teeth 12b with the external teeth 11b, the external gear 11 and the internal gear 12 are in a state where their centers are eccentric. In this state, the external teeth 11b and the internal teeth 12b include a portion that meshes with each other and a portion that does not mesh with each other, and the external gear 11 is configured to gradually change the meshing position of the internal teeth 12b with respect to the external teeth 11b. The internal gear 12 can be eccentrically rotated.

  The holding member 18 includes a cylindrical outer portion 18a that fits on the outer peripheral surface of the internal gear 12, and a pair of flange portions 18b and 18c that protrude in the inner diameter direction from both sides of the outer portion 18a. The flange portions 18b and 18c regulate the separation in the axial direction by sandwiching the external gear 11 and the internal gear 12 from both sides.

  The cylindrical shaft portion 13a of the wedge release member 13 is rotatably fitted in the shaft hole D of the cylindrical portion 11c of the external gear 11, and the wedge release member 13 is forward and backward with the shaft hole D of the cylindrical portion 11c as the center. To be rotated. The wedge release member 13 is provided with a large-diameter pressing portion 13b located on the outer diameter side of the cylindrical shaft portion 13a with the cylindrical portion 11c interposed therebetween, and both end portions in the circumferential direction of the pressing portion 13b are a pair of pressing surfaces 13c and 13d. It has become. A serration 13e is formed on the inner cylindrical surface of the cylindrical shaft portion 13a. Although not shown in the figure, there is provided means for restricting the movement of the wedge release member 13 in the rotational axis direction relative to the external gear 11 in a state where the cylindrical shaft portion 13a is inserted into the shaft hole D of the cylindrical portion 11c.

  Between the inner side guide surface S1 comprised by the outer peripheral surface of the cylindrical part 11c of the external gear 11, and the outer side guide surface S2 comprised by the inner peripheral surface of the cylindrical rib-shaped part 12c of the internal gear 12 (eccentric space) A wedge member 14 is inserted into the wedge member 14. The wedge member 14 includes a first wedge member (overlapping wedge member) 20 and a second wedge member (overlapping wedge member) 40. In the following description, portions common to the first wedge member 20 and the second wedge member 40 will be described as representatives of either the first wedge member 20 or the second wedge member 40, and the other portions will correspond to each other. Is indicated by a symbol in parentheses, and detailed description is omitted.

  The first wedge member 20 (second wedge member 40) has an inner cam portion (inner contact portion) 21 (41) and an outer cam portion (outer contact portion) 22 (42). (43) connected to form. The inner cam portion 21 (41) and the outer cam portion 22 (42) are formed so as to be displaced in the radial direction, and the inner cam portion 21 (41) has an inner radius with the same curvature as the inner guide surface S1. An inner sliding contact surface R21 (R41), which is a curved surface (cylindrical inner surface) capable of sliding contact with the guide surface S1, is formed, and has the same curvature as the outer guide surface S2 on the outer peripheral side of the outer cam portion 22 (42). An outer sliding contact surface R22 (R42), which is a curved surface (cylindrical outer surface) capable of sliding contact with the outer guide surface S2, is formed. Further, an outer peripheral interlocking surface T21 (T41) that is a curved surface (cylindrical outer surface) having a different curvature from the inner sliding contact surface R21 (R41) is formed on the outer peripheral side of the inner cam portion 21 (41), and the outer cam portion 22 ( 42), an inner peripheral interlocking surface T22 (T42) that is a curved surface (cylindrical inner surface) having a different curvature from the outer sliding contact surface R22 (R42) is formed. The inner cam portion 21 (41) has a large radial width from the inner sliding contact surface R21 (R41) to the outer peripheral interlocking surface T21 (T41) on the side closer to the connection portion 23 (43), and from the connection portion 23 (43). The taper has a tapered wedge shape that gradually decreases the radial width from the inner sliding contact surface R21 (R41) to the outer peripheral interlocking surface T21 (T41) as it moves away from the front end. The front end portion of the inner cam portion 21 (41) is a narrow end surface H21 (H41) that is a radial surface connecting the inner sliding contact surface R21 (R41) and the outer peripheral interlocking surface T21 (T41). The outer cam portion 22 (42) has a tapered shape that gradually increases the radial width from the outer sliding contact surface R22 (R42) to the inner peripheral interlocking surface T22 (T42) as it moves away from the connection portion 23 and advances toward the distal end side. have. The front end portion of the outer cam portion 22 (42) is a wide end surface H22 (H42) which is a radial surface connecting the outer sliding contact surface R22 (R42) and the inner peripheral interlocking surface T22 (T42).

  In the first wedge member 20 (second wedge member 40), one of the front and rear surfaces of the gears 11 and 12 facing in the axial direction (the surface visible on the near side in FIGS. 2, 3 and 6) is the surface 24. (44) The other side is the back surface 25 (45). The first wedge member 20 and the second wedge member 40 are combined with the connection portion 23 and the connection portion 43 crossing so that the front surface 24 and the front surface 44 and the back surface 25 and the back surface 45 are substantially flush with each other. Specifically, the connecting portion 23 of the first wedge member 20 is formed with a concave portion 26 facing the back surface 25 side, and the connecting portion 43 of the second wedge member 40 is formed with a concave portion 46 facing the front surface 44 side. The connection portion 23 and the connection portion 43 intersect with each other in a state where the bottom surfaces of the recess 26 and the recess 46 are in contact with each other. Then, the inner cam portion 21 and the outer cam portion 42 are positioned so as to overlap in the radial direction in a positional relationship in which the outer peripheral interlocking surface T21 and the inner peripheral interlocking surface T42 come into contact with each other, and the inner cam portion 41 and the outer cam portion 22 are outer peripheral interlocking surfaces. It is positioned so as to overlap in the radial direction in a positional relationship in which T41 and the inner peripheral interlocking surface T22 abut. The first wedge member 20 and the second wedge member 40 in a superposed state are slidably contacted with the outer peripheral interlocking surface T21 and the inner peripheral interlocking surface T42, and the outer peripheral interlocking surface T41 and the inner peripheral interlocking surface T22 in the circumferential direction. Some amount of relative movement is possible. In the relative movement of the first wedge member 20 in the circumferential direction with respect to the second wedge member 40, the side wall surface of the connection portion 23 abuts against the respective circumferential end surfaces of the inner cam portion 41 and the outer cam portion 42 facing the recess 46. It is limited by. Similarly, the relative movement of the second wedge member 40 in the circumferential direction with respect to the first wedge member 20 is caused by the side wall surface of the connection portion 43 with respect to the respective circumferential end surfaces of the inner cam portion 21 and the outer cam portion 22 facing the recess 26. It is limited by being applied. In other words, the concave portion 26 (46) between the inner cam portion 21 (41) and the outer cam portion 22 (42) is more circumferential than the width of the connecting portion 43 (23) intersecting on the concave portion 26 (46). Since it is formed as a concave portion that is long in the direction, a slight relative movement of the first wedge member 20 and the second wedge member 40 in the circumferential direction is allowed.

  In a state where the first wedge member 20 and the second wedge member 40 are combined, the wedge member 14 has a symmetrical shape on both sides with respect to the wedge center line P. More specifically, the intersection of the connecting portion 23 and the connecting portion 43 is located on the wedge center line P, and one wedge-shaped portion including the inner cam portion 21 and the outer cam portion 42, the inner cam portion 41, and the outer cam. The other wedge-shaped portion formed of the portion 22 has a symmetrical shape with respect to the wedge center line P. The wedge center line P passes through the center of the cylindrical portion 11c (shaft hole D concentric with the inner guide surface S1) of the external gear 11 and extends in the radial direction of the cylindrical gear 11c in a completed state of the reduction gear mechanism 10 described later. It is a virtual line.

  In the wedge member 14 configured as described above, the inner sliding contact surface R21 and the inner sliding contact surface R41 having a large curvature are opposed to the inner guide surface S1, and the outer sliding contact surface R22 and the outer sliding contact surface R42 having a small curvature are formed. It is inserted between the cylindrical rib portion 12c of the internal gear 12 and the cylindrical portion 11c of the external gear 11 so as to face the outer guide surface S2. The inner sliding contact surface R21 and the inner sliding contact surface R41 are slidably contacted with the inner guide surface S1, and the outer sliding contact surface R22 and the outer sliding contact surface R42 are slidably contacted with the outer guide surface S2. To do.

  The biasing spring 15 is engaged with the first wedge member 20 and the second wedge member 40. In the first wedge member 20 (second wedge member 40), a spring hook portion 27 (47) is formed at the boundary between the inner cam portion 21 (41) and the connection portion 23 (43). The spring hook portion 27 (47) includes a concave portion having an arc-shaped cross section formed on the circumferential end surface of the inner cam portion 21 (41), and a circular cross-sectional hole formed continuously through the concave portion and penetrating into the connecting portion 23 (43). It is constituted by. The biasing spring 15 includes a one-turn annular portion 15a, a pair of radially bent portions 15b and 15c bent from the annular portion 15a in the inner diameter direction, and an axis of the annular portion 15a from each radially bent portion 15b and 15c. A torsion spring having axial end portions (spring end portions) 15d and 15e raised in the direction, and the annular portion 15a is an annular back side formed on the back side of the cylindrical rib-like portion 12c of the internal gear 12 It is supported in the recess 12e. The axial end 15d of the biasing spring 15 engages with the spring hook 27 of the first wedge member 20, and the axial end 15e engages with the spring hook 47 of the second wedge member 40. The biasing spring 15 is bent in this state, and the axial end portions 15d and 15e press the inner cam portion 21 and the inner cam portion 41 in the separating direction by the restoring force, respectively. This pressing force acts in the wedge driving direction of the first wedge member 20 and the second wedge member 40 with respect to the inner guide surface S1 and the outer guide surface S2, and when the wedge release member 13 is not rotated, the outer force is applied via the wedge member 14. The relative position of the tooth gear 11 and the internal gear 12 is maintained constant.

  In a state where the wedge member 14 is inserted between the inner guide surface S1 and the outer guide surface S2, the internal gear 12 is positioned eccentrically with respect to the external gear 11, and in this eccentric state, a part of the external teeth 11b is positioned. Thus, a part of the inner teeth 12b is engaged. At this time, as shown in FIG. 2, the center C <b> 1 of the inner guide surface S <b> 1 and the center C <b> 2 of the outer guide surface S <b> 2 are eccentric in the direction along the wedge center line P of the wedge member 14. The wedge release member 13 is configured such that the cylindrical shaft portion 13a of the wedge release member 13 is rotatably supported in the shaft hole D of the cylindrical portion 11c of the external gear 11, and the pressing surface 13c of the pressing portion 13b is the first wedge. The narrow end surface H21 of the member 20 is opposed, and the pressing surface 13d is opposed to the narrow end surface H41 of the second wedge member 40.

  The pair of reduction gear mechanisms 10 are symmetrically arranged on both sides of each seat, and the wedge release member 13 in the left and right reduction gear mechanisms 10 has a connecting shaft (not shown) inserted and fixed to the serration 13e of the cylindrical shaft portion 13a. Are connected through. The connecting shaft and the wedge releasing member 13 are rotationally driven by a driving force of a motor (not shown) when adjusting the inclination angle of the seat back.

  In the reduction gear mechanism 10 having the above structure, the urging spring 15 is applied to the first wedge member 20 and the second wedge member 40 in a state in which no rotational operation force is applied to the connecting shaft (wedge release member 13) from the outside. The force in the direction in which the inner slidable contact surface R21 and the inner slidable contact surface R41 are pressed against the inner guide surface S1, and the outer slidable contact surface R22 and outer slidable contact surface R42 are pressed into contact with the outer guide surface S2, that is, the force in the direction of driving the wedge. Is given. Therefore, even if a rotational force is applied to the external gear 11 and the internal gear 12, the inner cam portion 21 and the outer cam portion 42, and the inner cam portion 41 and the outer cam portion 22 are each paired as a wedge. It functions to regulate the relative movement of the external gear 11 and the internal gear 12. Therefore, the locked state of the reduction gear mechanism 10 is maintained, and the tilting of the seat back is restricted.

  When the wedge release member 13 is rotated counterclockwise in FIGS. 2 and 3 in this locked state, the pressing surface 13c of the wedge release member 13 presses the narrow end surface H21 of the first wedge member 20 constituting the wedge member 14. Then, a force is applied to pull out the first wedge member 20 in a direction opposite to the wedge driving direction (clockwise direction) against the biasing force of the biasing spring 15. The first wedge member 20 presses the inner peripheral interlocking surface T42 by the outer peripheral interlocking surface T21 and the outer peripheral interlocking surface T41 by the inner peripheral interlocking surface T22, and the same rotation as the first wedge member 20 also with respect to the second wedge member 40. Directional force is applied. Therefore, the wedge member 14 rotates counterclockwise along the inner guide surface S1 of the cylindrical portion 11c of the external gear 11 in a state where the first wedge member 20 and the second wedge member 40 are integrated. On the contrary, when the wedge release member 13 is rotated clockwise, the pressing surface 13d presses the narrow end surface H41, and the second wedge member 40 is wedged against the biasing force of the biasing spring 15. A pulling force is applied in the direction opposite to the driving direction (counterclockwise direction). Then, the second wedge member 40 presses the inner peripheral interlocking surface T22 by the outer peripheral interlocking surface T41, the outer peripheral interlocking surface T21 by the inner peripheral interlocking surface T42, and presses the first wedge member 20 in the same rotational direction. Therefore, the wedge member 14 rotates in the clockwise direction along the inner guide surface S1 in a state where the second wedge member 40 and the first wedge member 20 are integrated.

  When the wedge member 14 rotates along the inner guide surface S1 of the cylindrical portion 11c of the external gear 11, the outer slide contact surface R22 of the first wedge member 20 and the outer slide contact surface R42 of the second wedge member 40 are the outer guide surfaces. The internal gear 12 is pressed in the outer diameter direction while changing the pressing point in sliding contact with S2. Since the internal gear 12 is supported by the wedge member 14 at an eccentric position where the internal teeth 12b mesh with the external teeth 11b, the internal gear 12 rotates eccentrically relative to the external gear 11 when the wedge member 14 rotates. The meshing position of the outer teeth 11b and the inner teeth 12b is changed. Specifically, when the wedge release member 13 is rotated in the clockwise direction in FIGS. 2 and 3, the internal gear 12 rotates in the clockwise direction in FIG. 2 while changing the center position with respect to the external gear 11. When the wedge releasing member 13 is rotated counterclockwise in FIGS. 2 and 3, the internal gear 12 rotates counterclockwise in the same figure while changing the center position with respect to the external gear 11. . As a result, the tilt angle of the seat back can be adjusted by tilting the upper arm with respect to the lower arm. The eccentric relative rotation between the external gear 11 and the internal gear 12 is decelerated from the rotation of the wedge release member 13, and the upper arm is tilted little by little with respect to the lower arm. Can be adjusted. When the rotation of the wedge release member 13 is stopped, the eccentric rotational movement of the internal gear 12 with respect to the external gear 11 is stopped, and the wedge effect of the wedge member 14 is obtained again by the biasing force of the biasing spring 15. It returns to the locked state where the tilt of the is restricted.

  The reduction gear mechanism 10 may be provided with stopper protrusions in the recess 11d of the external gear 11 and the recess 12d of the internal gear 12 in order to regulate the maximum tilt angle of the upper arm with respect to the lower arm. When a predetermined amount of relative rotation occurs between the external gear 11 and the internal gear 12, the stopper projections come into contact with each other to restrict the rotation operation, and further change in the angle of the seat back is limited.

  The first wedge member 20 and the second wedge member 40 constituting the wedge member 14 are moved relative to each other in the rotational direction so as to change the crossing position of the connection portion 23 and the connection portion 43, thereby sandwiching the wedge center line P. The wedge shape on both sides (the relative position between the inner sliding contact surface R21 and the outer sliding contact surface R42, the relative position between the inner sliding contact surface R41 and the outer sliding contact surface R22) changes. FIG. 7A shows that the connection portion 23 of the first wedge member 20 is closest to the inner cam portion 41 side of the second wedge member 40, and the connection portion 43 of the second wedge member 40 is the inner side of the first wedge member 20. The state where the 1st wedge member 20 and the 2nd wedge member 40 are located in the 1st relative rotational movement end made to approach the cam part 21 side most is shown. In the position of FIG. 7A, the further rotation of the first wedge member 20 in the counterclockwise direction is the circumferential end of the inner cam portion 41 of the second wedge member 40 (the end opposite to the narrow end face H41). Part) is regulated by the contact of the connection part 23 with the part. Further, the clockwise rotation of the second wedge member 40 is restricted by the contact of the connecting portion 43 with the end of the inner cam portion 21 of the first wedge member 20 (the end opposite to the narrow end face H21). Is done. At this time, the outer peripheral interlocking surface T21 and the inner peripheral interlocking surface T42, and the outer peripheral interlocking surface T41 and the inner peripheral interlocking surface T22 are in contact with each other without any gap. Therefore, the radial distance of the outer sliding contact surface R22 (R42) relative to the inner sliding contact surface R21 (R41) is minimized, and the amount of eccentricity between the center C1 of the inner guide surface S1 and the center C2 of the outer guide surface S2 is minimized. .

  FIG. 7C shows that the connection portion 23 of the first wedge member 20 is closest to the outer cam portion 42 side of the second wedge member 40, and the connection portion 43 of the second wedge member 40 is outside the first wedge member 20. The state where the 1st wedge member 20 and the 2nd wedge member 40 are located in the 2nd relative rotational movement end made to approach the cam part 22 side most is shown. 7C, further clockwise rotation of the first wedge member 20 causes the circumferential end of the outer cam portion 42 of the second wedge member 40 (the end opposite to the wide end face H42). Is restricted by the contact of the connecting portion 23 with respect to. Further, the counterclockwise rotation of the second wedge member 40 is caused by the contact of the connecting portion 43 with the circumferential end (the end opposite to the wide end face H22) of the outer cam portion 22 of the first wedge member 20. Regulated by contact. At this time, in the vicinity of the connecting portion 23 (43), a slight gap is formed between the outer peripheral interlocking surface T21 and the inner peripheral interlocking surface T42 and between the outer peripheral interlocking surface T41 and the inner peripheral interlocking surface T22. This increases the radial distance of the outer sliding contact surface R22 (R42) relative to the inner sliding contact surface R21 (R41), and the amount of eccentricity between the center C1 of the inner guide surface S1 and the center C2 of the outer guide surface S2 is maximized. .

  FIG. 7B shows a state where the first wedge member 20 and the second wedge member 40 are at an intermediate position between the two relative rotational movement ends. In the state of FIG. 7B, in the vicinity of the connecting portion 23 (43), between the outer peripheral interlocking surface T21 and the inner peripheral interlocking surface T42 and between the outer peripheral interlocking surface T41 and the inner peripheral interlocking surface T22. A gap that is smaller than the above state is formed. As a result, the radial distance of the outer sliding contact surface R22 (R42) to the inner sliding contact surface R21 (R41) becomes a size between FIG. 7 (A) and FIG. 7 (C), and the center of the inner guide surface S1. The amount of eccentricity between C1 and the center C2 of the outer guide surface S2 is an intermediate value.

  The radial imaginary line connecting the narrow end face H21 (H41) of the first wedge member 20 (second wedge member 40) and the center C1 of the inner guide surface S1 is defined as Q, and the angle formed between the imaginary line Q and the wedge centerline P. Is the minimum amount of eccentricity in FIG. 7A, the median amount of eccentricity in FIG. 7B, and the respective angles θ1, θ2, and θ3 at the maximum amount of eccentricity in FIG. The relationship is θ1> θ2> θ3. According to the configuration of the present embodiment, the difference between the angle θ1 when the amount of eccentricity is minimum and the angle θ3 when the amount of eccentricity is maximum can be suppressed small. The pressing portion 13b of the wedge release member 13 is set to a size that does not interfere with the first wedge member 20 and the second wedge member 40 in an angle θ3 where the circumferential interval between the narrow end surface H21 and the narrow end surface H41 is the smallest. Is done. Then, by changing the relative positions of the first wedge member 20 and the second wedge member 40 as described above, it is possible to absorb variations in the dimensions of the inner guide surface S1 and the outer guide surface S2.

  In the reduction gear mechanism 10 described above, the wedge member 14 that is inserted between the external gear 11 and the internal gear 12 and holds each other in an eccentric state is configured by a combination of the first wedge member 20 and the second wedge member 40. doing. The first wedge member 20 and the second wedge member 40 intersect the connecting portions 23 and 43 with each other on the wedge center line P, and in one region sandwiching the wedge center line P, the inner cam of the first wedge member 20 The portion 21 is in contact with the inner guide surface S1, the outer cam portion 42 of the second wedge member 40 is in contact with the outer guide surface S2, and in the other region across the wedge center line P, the second wedge member 40 The inner cam portion 41 contacts the inner guide surface S1, and the outer cam portion 22 of the first wedge member 20 contacts the outer guide surface S2. When the narrow end surface H21 (H41) of the first wedge member 20 (second wedge member 40) is pressed by the pressing surface 13c (13d) of the wedge releasing member 13, the first wedge member 20 ( The second wedge member 40) is pressed and moved, and the second wedge member 40 (first wedge member 20) is brought into contact with the outer peripheral interlocking surface T21 and the inner peripheral interlocking surface T42, and the inner peripheral interlocking surface T22 and the outer peripheral interlocking surface T41. ) Immediately exerts a pressing force. Therefore, the first wedge member 20 and the second wedge member 40 can be rotated without time lag, and the operation from the rotational drive of the wedge release member 13 to the eccentric relative rotation of the external gear 11 and the internal gear 12 is performed. It has excellent responsiveness. Further, in a state where the first wedge member 20 and the second wedge member 40 are combined, the wedge shapes on both sides sandwiching the intersecting portion (wedge center line P) of the connecting portions 23 and 43 are symmetric, and the wedge releasing member 13 Since the narrow end faces H21 and H41 that receive the pressure are also arranged symmetrically, the drive load does not vary due to the difference in the rotation direction of the wedge release member 13, and the operation stability is excellent.

  8 to 13 show the reduction gear mechanism 110 of the second embodiment. The speed reduction gear mechanism 110 is different from the speed reduction gear mechanism 10 of the previous embodiment in the shapes of the first wedge member (overlapping wedge member) 120 and the second wedge member (overlapping wedge member) 140 constituting the wedge member 114. The other configuration is the same as that of the reduction gear mechanism 10. Portions common to the previous embodiment are denoted by the same reference numerals and description thereof is omitted. Further, in the following description, the parts common to the first wedge member 120 and the second wedge member 140 will be described by representing one of the first wedge member 120 and the second wedge member 140, and the other will correspond. The portions to be performed are indicated by reference numerals in parentheses, and detailed description thereof is omitted.

  As shown in FIG. 13, the first wedge member 120 (second wedge member 140) connects the inner cam portion (inner contact portion) 121 (141) and the outer cam portion (outer contact portion) 122 (142). It is the shape connected by the part 123 (143). The inner cam portion 121 (141) and the outer cam portion 122 (142) are displaced in the radial direction, and have the same curvature as the inner guide surface S1 of the external gear 11 on the inner peripheral side of the inner cam portion 121 (141). The inner slidable contact surface R121 (R141) that can be slidably contacted with the inner guide surface S1 is formed on the outer peripheral side of the outer cam portion 122 (142) with the same curvature as the outer guide surface S2 of the internal gear 12. An outer sliding contact surface R122 (R142) capable of sliding contact with the guide surface S2 is formed. Further, an outer peripheral interlocking surface T121 (T141) having a different curvature from the inner sliding contact surface R121 (R141) is formed on the outer peripheral side of the inner cam portion 121 (141), and on the inner peripheral side of the outer cam portion 122 (142), An inner peripheral interlocking surface T122 (T142) having a different curvature from the outer sliding contact surface R122 (R142) is formed. As the inner cam portion 121 (141) advances from the side closer to the connecting portion 123 (143) toward the narrow end surface H121 (H141), the distance between the inner sliding contact surface R121 (R141) and the outer peripheral interlocking surface T121 (T141) ( It has a tapered wedge shape that gradually decreases the radial width. As the outer cam portion 122 (142) advances from the side closer to the connection portion 123 (143) toward the wide end surface H122 (H142), the distance between the outer sliding contact surface R122 (R142) and the inner peripheral interlocking surface T122 (T142) ( It has a tip shape that increases the radial width.

  When the bottom surface of the concave portion 126 and the concave portion 146 are brought into contact with each other so that the connection portion 123 and the connection portion 143 intersect each other, and the first wedge member 120 and the second wedge member 140 are combined, the inner cam portion 121 and the outer cam portion 142 are in the radial direction. The inner cam portion 141 and the outer cam portion 122 are positioned so as to overlap each other in the radial direction. In the combined state of the first wedge member 120 and the second wedge member 140, the wedge member 114 has a symmetrical shape on both sides with respect to the wedge center line P, and the surface 124 of the first wedge member 120 and the second wedge member 140 The front surface 144, the back surface 125, and the back surface 145 are substantially flush with each other. The axial end portion 15d and the axial end portion 15e of the biasing spring 15 are engaged with the spring hook portion 127 of the first wedge member 120 and the spring hook portion 147 of the second wedge member 140, respectively. The inner cam portion 121 and the inner cam portion 141 are pressed in the separating direction by the spring 15.

  The basic structure of the first wedge member 120 (second wedge member 140) is the same as that of the first wedge member 20 (second wedge member 40) of the previous embodiment. The first wedge member 120 (second wedge member 140) is different from the previous embodiment in the relationship between the circumferential lengths of the inner cam portion 121 (141) and the outer cam portion 122 (142). With reference to (143), the outer cam portion 122 (142) extends longer in the circumferential direction than the inner cam portion 121 (141). Therefore, when the first wedge member 120 and the second wedge member 140 are combined and placed between the inner guide surface S1 and the outer guide surface S2, the inner cam portion 121 (141) is thinned as shown in FIGS. The wide end surface H122 (H142) of the outer cam portion 122 (142) is located closer to the pressing surfaces 13c and 13d of the wedge releasing member 13 than the wide end surface H121 (H141). That is, the pressing surface 13 c of the wedge releasing member 13 faces the wide end surface H 142 of the second wedge member 140, and the pressing surface 13 d faces the wide end surface H 122 of the first wedge member 120.

  When the wedge releasing member 13 is turned counterclockwise in FIGS. 9 and 10, the pressing surface 13 c of the wedge releasing member 13 presses the wide end surface H 142 of the second wedge member 140. Then, the pressed second wedge member 140 presses the outer peripheral interlocking surface T121 by the inner peripheral interlocking surface T142 and the inner peripheral interlocking surface T122 by the outer peripheral interlocking surface T141, and the second wedge member 120 is also pressed against the first wedge member 120. The same rotational force as that of the member 140 is applied. Therefore, the wedge member 114 rotates counterclockwise along the inner guide surface S1 of the cylindrical portion 11c of the external gear 11 in a state where the second wedge member 140 and the first wedge member 120 are integrated. The tooth gear 12 rotates counterclockwise in FIGS. 9 and 10 while changing the center position with respect to the external gear 11. On the contrary, when the wedge release member 13 is rotated in the clockwise direction of FIGS. 9 and 10, the pressing surface 13 d presses the wide end surface H 122 of the first wedge member 120. Then, the pressed first wedge member 120 presses the outer peripheral interlocking surface T141 by the inner peripheral interlocking surface T122, the inner peripheral interlocking surface T142 by the outer peripheral interlocking surface T121, and presses the second wedge member 140 in the same rotational direction. . Therefore, the wedge member 114 rotates clockwise along the inner guide surface S <b> 1 in a state where the first wedge member 120 and the second wedge member 140 are integrated, and as a result, the internal gear 12 moves relative to the external gear 11. 9 and FIG. 10, while rotating the center position.

  As mentioned above, although demonstrated based on illustration embodiment, this invention is not limited to this embodiment. Although the above embodiment is an example applied to a seat reclining device, it can be applied to a part where a link of a seat lifter mechanism that lifts and lowers a seat cushion or a link of a tilt mechanism is rotated. In addition to the seat, the present invention can also be applied to a reduction gear portion of a geared motor in which a motor and a reduction gear used in a power window, a power seat, a power slide door, a power back door, a power luggage and the like are integrated. Further, when applied to a seat reclining device, contrary to the above-described embodiment, it can also be applied to a reduction gear mechanism of a type in which the external gear is fixed to the upper arm and the internal gear is fixed to the lower arm. is there.

DESCRIPTION OF SYMBOLS 10 Reduction gear mechanism 11 External gear 11a Fixed protrusion 11b External tooth 11c Cylindrical part 11d Recessed part 12 Internal gear 12a Fixed protrusion 12b Internal tooth 12c Cylindrical rib-like part (circular hole)
12d Concave portion 12e Back side concave portion 13 Wedge release member (drive means, rotation transmission member)
13a cylindrical shaft portion 13b pressing portion 13c 13d pressing surface 13e serration 14 114 wedge member (eccentric holding means)
15 Biasing spring (eccentric holding means, biasing member)
15b 15c Radial direction bending part 15d 15e Axial direction edge part (spring end part)
18 Holding member 18a Outer portion 18b 18c Flange portion 20 120 First wedge member (overlapping wedge member)
21 41 121 141 Inner cam part (inner contact part)
22 42 122 142 Outer cam part (outer contact part)
23 43 123 143 Connecting portion 24 44 124 144 Front surface 25 45 125 145 Back surface 26 46 126 146 Recessed portion 27 47 127 147 Spring hook portion 40 140 Second wedge member (overlapping wedge member)
C1 Center of inner guide surface C2 Center of outer guide surface D Shaft hole H21 H41 H121 H141 Narrow end surface H22 H42 H122 H142 Wide end surface R21 R41 R121 R141 Inner slidable contact surface R22 R42 R122 R142 Outer slidable contact surface S1 Inner guide surface (cylindrical) Outer peripheral surface)
S2 Outer guide surface (inner peripheral surface of circular hole)
T21 T41 Outer peripheral interlocking surface T22 T42 Inner peripheral interlocking surface

Claims (7)

An external gear having external teeth on the outer periphery, which is fixed to any one of the support member and the rotation member rotatable relative to the support member, positioned at the center of rotation thereof;
An internal gear formed with an internal tooth having a larger number of teeth than the external tooth meshing with the external tooth of the external gear, and fixed to the other of the support member and the rotating member;
A large-diameter circular hole provided on one and the other of the external gear and the internal gear with the respective axes as centers, and a cylindrical portion having a smaller diameter than the circular hole;
An eccentric holding means which is inserted between the inner peripheral surface of the circular hole and the outer peripheral surface of the cylindrical portion, and keeps the external gear and the internal gear meshed in an eccentric state where their center positions are different from each other; and the cylinder A drive means that is rotatably supported by the inner peripheral part of the part and operates the eccentric holding means by the rotation to cause the external gear and the internal gear to perform eccentric rotation accompanied by a change in meshing position;
In a reduction gear mechanism having
The eccentric holding means is
The inner abutting portion that comes into slidable contact with the outer peripheral surface of the cylindrical portion and the outer abutting portion that comes into slidable contact with the inner peripheral surface of the circular hole are provided at different circumferential positions, respectively. The inner abutment portion and the outer abutment portion are adjacent to each other in the radial direction, and the connection portion between the inner abutment portion and the outer abutment portion intersects each other, and the inner circumferential surface of the circular hole Two overlapping wedge members inserted between the outer peripheral surfaces of the cylindrical portion; and the two overlapping wedge members are moved and urged in the forward and reverse rotational directions, and the inner abutting portions of the two overlapping wedge members And a biasing member that presses the outer abutting portion against the outer peripheral surface of the cylindrical portion and the inner peripheral surface of the circular hole, respectively, and maintains the relative eccentric position of the external gear and the internal gear constant.
A reduction gear mechanism comprising: 2. The reduction gear mechanism according to claim 1, wherein the inner contact portion of each of the two overlapping wedge members has an inner sliding contact surface that is a curved surface that is slidably contacted with an outer peripheral surface of the cylindrical portion. The outer peripheral interlocking surface, which is a curved surface having a curvature smaller than that of the inner sliding contact surface, is provided on the outer peripheral side, and the outer periphery from the inner sliding contact surface as it advances away from the connection portion toward the distal end side. Reduce the radial width to the interlocking surface,
Each of the outer contact portions of the two overlapping wedge members has an outer sliding contact surface, which is a curved surface that comes into slidable contact with the inner peripheral surface of the circular hole, on the outer peripheral side. A radial width from the outer sliding contact surface to the inner peripheral interlocking surface as it advances toward the tip side away from the connecting portion, having an inner peripheral interlocking surface that is a curved surface having a larger curvature than the contact surface Increase the
A reduction gear mechanism in which a rotational force acting on one overlapping wedge member is transmitted to the other overlapping wedge member via the outer peripheral interlocking surface and the inner peripheral interlocking surface. 3. The reduction gear mechanism according to claim 1 or 2, wherein the connecting portion of the two overlapping wedge members has a concave portion facing in a direction along a rotation axis of the external gear and the internal gear. A reduction gear mechanism in which the concave portions are fitted to each other and the two overlapping wedge members are combined. The reduction gear mechanism according to any one of claims 1 to 3, wherein the two overlapped wedge members are moved in the circumferential direction to change the crossing position of the connection portions of the external gear and the internal gear. A reduction gear mechanism that changes the amount of eccentricity of the toothed gear. 5. The reduction gear mechanism according to claim 1, wherein the urging member includes an annular coil portion and two formed on one and the other of the two overlapping wedge members protruding from the coil portion. A reduction gear mechanism comprising a torsion spring having a pair of spring end portions engaged with a spring hook portion. 6. The reduction gear mechanism according to claim 1, wherein the driving means includes a shaft portion rotatably inserted into the cylindrical portion, and the inner contact portions of the two overlapping wedge members. A reduction gear mechanism comprising a rotation transmission member having a pressing portion capable of abutting against a circumferential end surface of the rotation transmission member. 6. The reduction gear mechanism according to claim 1, wherein the driving means includes a shaft portion rotatably inserted into the cylindrical portion, and the outer abutting portions of the two overlapping wedge members, respectively. A reduction gear mechanism comprising a rotation transmission member having a pressing portion capable of abutting against a circumferential end surface of the rotation transmission member.

Images