JP2023094209A - reclining device - Google Patents

Abstract

To provide a reclining device capable of preventing damaging of a through-hole boss by eliminating the through-hole boss of an external tooth gear and pressing a bottom surface of the highly rigid external tooth gear.SOLUTION: A reclining device 100 comprises: an external tooth gear 10; an internal tooth gear 20 having a cylindrical boss coaxial to an axial direction and a bottom-up bottom surface bottomed-up more than a bottom surface around the cylindrical boss; a bush 30 having a wedge-like cam storage on an inner peripheral surface and a projected part on a front surface side; a pair of wedge-like cams 50 permitting relative rotation of the external tooth gear 10 and the internal tooth gear 20; a biasing member 70 biasing the wedge-like cams in a separating direction; a drive member 60; and a rotary shaft 40 engaged with the drive member 60 to rotate the bush 30 via the drive member 60. The bush is in contact with a side surface of the bottom surface of the internal tooth gear.SELECTED DRAWING: Figure 3

Description

The present invention relates to a recliner.

As shown in FIG. 8, a seat reclining device 300 that holds a seat back so that it can tilt relative to a conventional seat cushion is connected to the frame of the seat back or the seat cushion and has external teeth formed on the outer peripheral surface. An external gear 310 having a through hole coaxial with the axial direction on the inner peripheral surface and a through hole boss portion 310a formed in the through hole, and an external gear 310 connected to a seat cushion or a seat back and meshable with the external teeth on the outer peripheral surface. It has an internal gear 320 having internal teeth and having a cylindrical boss portion 320 a coaxial with the axial direction on the inner peripheral surface, a cam 350 , a bushing 330 and an elastic body 370 .

The bushing 330 presses the through-hole boss portion 310a of the external gear 10, but the through-hole boss portion 310a of the external gear 10 protrudes like a burring portion, and is easily damaged due to its low rigidity. There was a problem.

Therefore, the present invention has been made in view of these problems. By eliminating the through-hole boss portion of the external gear and pressing the bottom surface portion of the external gear with high rigidity, the through-hole boss portion is damaged. To provide a reclining device that does not

In order to achieve the above object, the present invention employs the following means.

The reclining device of the present invention is
A seat reclining device that tiltably holds a seat back frame that forms a seat back with respect to a seat cushion frame that forms a seat cushion,
an external gear that is directly or indirectly attached to one of the seat cushion frame and the seat back frame, has external teeth formed on an outer peripheral surface, and has a through hole coaxial with the axial direction formed on an inner peripheral surface; ,
an internal tooth that is directly or indirectly attached to the other of the seat cushion frame and the seat back frame and that can mesh with the external tooth provided on the inner peripheral surface by at least one more than the external tooth; an internal gear having a cylindrical boss coaxial with the direction, and a bottom upper bottom portion raised above a bottom portion formed around the cylindrical boss;
It is disposed between the inner periphery of the through hole of the external gear and the outer periphery of the cylindrical boss of the internal gear, and is formed into an annular shape by two arcuate members of a first bush and a second bush. a bush formed so that the center of the cylindrical boss is eccentric with the center of the cylindrical boss, and has a wedge-shaped cam accommodating portion on the inner peripheral surface side and a protrusion on the front side;
It is arranged in the wedge-shaped cam accommodating portion of the bushing, and the external gear and the internal gear contact each other by contacting the outer peripheral surface of the cylindrical boss of the internal gear and the inner peripheral surface of the wedge-shaped cam accommodating portion. Relative rotation of the external gear and the internal gear is controlled by sliding the outer peripheral surface of the cylindrical boss of the internal gear and the inner peripheral surface of the through hole of the external gear. a pair of wedge-shaped cams that allow
a biasing member that biases the wedge-shaped cams in a direction to separate them;
a drive member that is coaxially and rotatably fitted into the cylindrical boss of the internal gear and has a fitting hole on the inside and a protrusion that engages the protrusion of the bush on the outer peripheral side;
a rotating shaft fitted to the drive member and rotating the bush through the drive member;
with
The bush is in contact with the side surface of the bottom surface of the external gear.

In the reclining device according to the present invention, the position of the bush is arranged at a position higher than the bottom surface of the internal gear, so that the position where the bush contacts the external gear is in contact with the side surface of the bottom surface of the external gear. It is what I did. By adopting such a configuration, the side surface of the bottom surface with strong rigidity is pressed instead of pressing the through-hole boss portion, which is vulnerable to stress in the tilting direction, as in the conventional case, so that the external gear is damaged. can be prevented.

Further, in the reclining device according to the present invention, the upper bottom portion may be raised to at least a position corresponding to the bottom portion of the external gear.

By adopting such a configuration, the entire bush presses the side surface of the bottom surface of the external gear, so that damage to the external gear can be further prevented.

Further, in the reclining device according to the present invention,
A seat reclining device that tiltably holds a seat back frame that forms a seat back with respect to a seat cushion frame that forms a seat cushion,
It is directly or indirectly attached to one of the seat cushion frame and the seat back frame, has external teeth formed on the outer peripheral surface, and has a cylindrical boss coaxial with the axial direction formed on the inner peripheral surface, and the cylindrical boss is formed on the inner peripheral surface. an externally toothed gear having a bottom and upper bottom portion raised above a bottom portion formed around the periphery;
It is directly or indirectly attached to the other of the seat cushion frame and the seat back frame, and has an internal tooth meshable with the external tooth provided on the inner peripheral surface by at least one more than the external tooth. and an internal gear in which a through hole coaxial with the axial direction is formed;
A first bushing disposed between the inner circumference of the through hole of the internal gear and the outer circumference of the cylindrical boss of the external gear and a second bushing formed into an annular shape by two arcuate members, and the outer peripheral surface of the a bush formed so that the center of the cylindrical boss is eccentric with the center of the cylindrical boss, and has a wedge-shaped cam accommodating portion on the inner peripheral surface side and a protrusion on the front side;
The external gear and the internal gear are arranged in the wedge-shaped cam accommodating portion of the bush and contact the outer peripheral surface of the cylindrical boss of the external gear and the inner peripheral surface of the wedge-shaped cam accommodating portion. while regulating the relative rotation of the external gear and the inner peripheral surface of the through hole of the internal gear by sliding the outer peripheral surface of the cylindrical boss of the external gear and the inner peripheral surface of the through hole of the internal gear. a pair of wedge-shaped cams that allow rotation;
a biasing member that biases the wedge-shaped cams in a direction to separate them;
a drive member that is coaxially and rotatably fitted into the cylindrical boss of the external gear and has a fitting hole on the inside and a protrusion that engages with the protrusion of the bush on the outer peripheral side;
a rotating shaft fitted to the drive member and rotating the bush through the drive member;
with
The bush is in contact with the side surface of the bottom portion of the internal gear.

The present invention differs from the above invention in that the external gear is provided with a cylindrical boss and the internal gear is provided with a through hole. By arranging the bush at a higher position, the position where the bush comes into contact with the internal gear is in contact with the side surface of the bottom surface of the internal gear. By adopting such a configuration, since the side surface of the bottom surface having high rigidity is pressed, it is possible to prevent the external gear from being damaged.

Further, in the reclining device according to the present invention, the bottom upper bottom surface portion may be raised to at least a position corresponding to the bottom surface portion of the internal gear or higher.

By adopting such a configuration, the entire bush presses the side surface of the bottom surface of the internal gear, so that the internal gear can be further prevented from being damaged.

FIG. 1 is a schematic diagram of a vehicle seat 200 to which a reclining device 100 according to the first embodiment is attached. FIG. 2 is a front view showing the internal structure of the reclining device 100 according to the first embodiment. FIG. 3 is an exploded perspective view of the reclining device 100 according to the first embodiment. FIG. 4 is an AA cross-sectional view of the reclining device 100 according to the first embodiment. FIG. 5 is a perspective view of the external gear 10 of the reclining device 100 according to the first embodiment. FIG. 6 is a front view showing the relationship between the bush 30 and the wedge-shaped cam 50 of the reclining device 100 according to the first embodiment. FIG. 7 is an exploded perspective view of the reclining device 100 according to the second embodiment. FIG. 8 is a sectional view of a conventional reclining device 300. As shown in FIG.

Hereinafter, a reclining device 100 according to an embodiment of the present invention will be described in detail with reference to the drawings. 1 is a schematic diagram of a vehicle seat 200, FIG. 2 is a front view showing the internal structure of the reclining device 100, and FIG. 3 is an exploded perspective view of the reclining device 100. As shown in FIG. FIG. 4 is a cross-sectional view taken along line AA of FIG. It should be noted that the embodiments and drawings described below illustrate a part of the embodiments of the present invention, and are not used for the purpose of limiting to these configurations. The same or similar reference numerals are assigned to corresponding components in each figure. In addition, in FIG. 3, the directions indicated by the arrows in the drawing are referred to as "front" and "back", respectively.

(First embodiment)
The reclining device 100 according to the first embodiment, as shown in FIG. It is a device that is attached to give the seat back 220 a tilt function. Specifically, a mounting plate 230 (hereinafter referred to as “mounting plate, etc. ".") is indirectly attached and used.

As shown in FIGS. 2 to 4, the reclining device 100 according to the present invention mainly includes an external gear 10, an internal gear 20, a first bush 31 and a second bush 32. A bush 30, a rotating shaft 40, a wedge A cam 50, a driving member 60, a spring 70 as an urging member, a plate cover 80, and a shaft locking member 90 are provided. It should be noted that the rotating shaft 40 and the driving member 60 are omitted in FIG. 2 in order to make the internal structure easier to see.

As shown in FIG. 3, the external gear 10 is formed in a disk shape, has external teeth 11 formed on the outer peripheral surface, and has a through hole 12 provided in the center. The external gear 10 is provided with a protruding portion 13, and is attached to the vehicle seat by welding or the like in a state of being fitted in a fitting hole provided in an attachment plate or the like 230. As shown in FIG. As shown in FIG. 5, the external gear 10 has a standing portion 16 formed on the outer peripheral side, but does not have a cylindrical boss (so-called conventional burring portion) formed on the inner side.

The internal gear 20 is formed in a disk shape having a diameter larger than that of the external gear 10, and is formed with a recess 10a so that the external gear 10 can be mounted inside. Internal teeth 21 are formed on the surface. The number of internal teeth 21 is at least one greater than the number of teeth of the external teeth 11 of the external gear 10, and the external gear 10 and the internal gear 20 are, as shown in FIG. 10 and the center _C2 of the internal gear ₂₀ are eccentrically meshed with the internal teeth 21 and the external teeth 11 as indicated by the arrow d. Therefore, the external gear 10 and the internal gear 20 form a differential gear, and when the internal gear 20 makes one turn around the external teeth 11, the rotation progresses by the difference between the internal teeth 21 and the external teeth 11. become. That is, for example, when only one tooth is different, when the external gear 10 makes one turn around the internal gear 20, it rotates by one tooth. A cylindrical boss 22 is provided at the center of the internal gear 20, as shown in FIG. The raised bottom surface portion 23 is a portion that becomes a contact surface with a bush 30 to be described later. The raised bottom surface portion 23 is formed to have a circular outer periphery, and is preferably raised to a position higher than a position corresponding to the bottom surface 18 (see FIG. 5) of the external gear 10 when assembled. As shown in FIG. 4 , it is preferable that the amount of raising the bottom surface portion 23 is raised to the position f of the bottom surface 18 of the external gear 10 or more. This is because the entire thickness of the bush 30 can come into contact with the side surface of the external gear by manufacturing in this manner. The internal gear 20 is provided with a projecting portion 26, and is attached to the vehicle seat by welding or the like in a state of being fitted in a fitting hole provided in an attachment plate or the like 230. As shown in FIG.

The bushing 30 is arranged between the inner peripheral surface 12a of the through hole 12 of the external gear 10 and the outer peripheral surface 22a of the cylindrical boss 22 of the internal gear 20, and the first bushing 31 and the second bushing 32 are combined. 6, the center C3 of the circular outer peripheral surface ₃₃ and the center _C4 of the outer peripheral surface 22a of the cylindrical boss 22 are aligned with the center of the external gear 10. and the eccentricity of the center of the internal gear 20 is substantially the same. The first bushing 31 of the bushings 30 is an arcuate or crescent-shaped member arranged in the direction in which the through hole 12 of the external gear 10 is eccentric (the direction of the arrow in FIG. 6). A wedge-shaped cam accommodating portion 35 is formed on the peripheral side, and as shown in FIG. 6, it is arranged so that a pair of wedge-shaped cams 50 described later have a gap therebetween. The wedge-shaped cam accommodating portion 35 has a wedge angle set so that the gap between the bush 30 and the cylindrical boss 22 becomes narrower as it moves away from the opposing sides. The bush 30 can press and move the external gear 10 and the internal gear 20 in the eccentric direction by means of a wedge-shaped cam 50, which will be described later, so that rattling in the locked state can be prevented. The second bushing 32 is an arcuate or crescent-shaped member arranged on the side opposite to the direction in which the through hole 12 of the external gear 10 is eccentric (the direction of the arrow). are placed close enough to each other to create a slight gap between them. A protrusion 36 is provided at or near the end of the first bushing 31, and serves as a portion to which the rotation of a rotating shaft 40, which will be described later, is transmitted.

As shown in FIG. 3 or FIG. 6, the wedge-shaped cam 50a and the wedge-shaped cam 50b are formed symmetrically, and the concave surface 51 (inner surface) of the wedge-shaped cam 50 corresponds to the outer peripheral surface 22a of the cylindrical boss 22. , and the convex surface 52 (outer surface) is formed such that the thickness thereof gradually decreases from the sides facing each other. The wedge-shaped cam 50a and the wedge-shaped cam 50b are arranged so that the proximate end 53, which is the thicker side, faces each other and, as described above, is arranged in the wedge-shaped cam accommodating portion 35 of the bush 30 with external teeth. It is arranged so as to contact the inner peripheral surface 12a of the through hole 12 of the gear 10 .

A spring 70 as a biasing member is made of an elastic material, and as shown in FIG. ing. The end portions 72a and 72b are in contact with the proximal end portion 53 of the wedge-shaped cam 50, respectively, and urge the pair of wedge-shaped cams 50a and 50b in a direction to move away from each other.

The rotary shaft 40 is coaxially rotatably arranged with respect to the cylindrical boss 22 of the internal gear 20 . The rotary shaft 40 is rotationally driven when adjusting the tilting of the seat back 220, and has serrations 41 on the inner cylindrical surface to receive the rotational force of the tilting motor. The rotating shaft 40 has a cylindrical shaft portion 42 to be inserted into a driving member 60 (to be described later), and is provided with a plurality of locking portions 43 so as to rotate synchronously with the driving member 60 . there is

The drive member 60 is provided with a fitting hole 61 on its inner periphery so as to fit with the locking portion 43 of the rotating shaft 40, and is rotated as the rotating shaft 40 rotates. In addition, it has two engagement portions 63 formed so as to sandwich the projection portion 36 provided on the bush 30 from both sides, and the drive member 60 rotated by the rotation of the rotating shaft 40 is engaged. The protrusion 36 of the bushing 30 can be pressed by the portion 63 to rotate.

The plate cover 80 is a member for fixing the external gear 10, the internal gear 20, the bush 30, the rotating shaft 40, the bush 30, the wedge-shaped cam 50, the driving member 60, and the spring 70 so that they do not come off. is not limiting.

The shaft locking member 90 is a member that fixes the rotating shaft 40 .

The reclining device 100 manufactured in this way operates as follows. When no force is applied to the rotating shaft 40 and the rotating shaft 40 is not rotated, the pair of wedge-shaped cams 50a and 50b are biased by the spring 70 in a direction to move away from each other, and the outer peripheral surface of the cylindrical boss 22 of the internal gear 20 is pushed. 22 a and a wedge-shaped cam accommodating portion 35 of the bush 30 are pressed to bring the bush 30 into press contact with the inner peripheral surface 12 a of the through hole 12 of the external gear 10 . Therefore, relative motion between the internal gear 20 and the external gear 10 is locked, and the seat back 220 is in a locked state.

From this locked state, when the rotating shaft 40 is rotated counterclockwise in FIG. The bush 30 rotates from the portion 63 to the projecting portion 36 . A wedge angle is set between the wedge-shaped cam 50 b and the inner wall of the wedge-shaped cam accommodating portion 35 of the bush 30 , and the wedge-shaped inner wall contacts the wedge-shaped cam 50 . Due to the rotation of the bush 30, a clearance is generated between the inner wall of the wedge angle and the wedge-shaped cam 50, and the wedge is disengaged. As a result, gaps are generated between the bushing 30 and the cylindrical boss 22 and between the bushing 30 and the through hole 12 of the internal gear 20 , so that the external gear 10 can rotate with respect to the internal gear 20 . Along with this, the biasing force of 70 causes the wedge-shaped cam 50a to rotate counterclockwise so as to fill the gap. The wedge-shaped cam 50 rotates counterclockwise so as to slide together with the rotating shaft 40 and the bushing 30 . Thus, the external gear 10, the internal gear 20 and the rotating shaft 40 constitute a differential gear mechanism. It should be noted that clockwise rotation can also be performed in the same manner.

In the reclining device 100 manufactured in this manner, since the bush 30 is formed in a ring shape, when an external force is applied to the internal gear 20 or the external gear 10, the internal gear 20 or the external gear 10 is pushed in the direction of the external force or in the direction of the reaction force. When trying to move the toothed gear 10, the bushing 30 is perpendicular to the outer peripheral surface 22a of the cylindrical boss 22 of the internal gear 20 and the through hole 12 of the external gear 10 in the direction in which the toothed gear 10 is attempted to move. is sandwiched between them, and the components of force can be minimized to act as bearings, so sliding is stabilized and smooth rotation can be ensured.

Further, when the rotating shaft 40 is rotated, the engaging portion 63 without a gap is engaged with the rotating direction of the protrusion 36 of the bush 30, so that the gear mechanism can be operated immediately without a time lag. can be done. At this time, since the bush 30 rotates from the engagement portion 63 to the protrusion 36, it rotates so as to follow the eccentric direction of the internal gear 20 and the external gear 10, and the bush 30 rotates. It is in contact with most of the outer peripheral surface 22a of the cylindrical boss 22, and when sliding, the sliding is stabilized and smooth rotation can be ensured. On the other hand, since the wedge-shaped cam 50 urges the external gear 10 to move in the eccentric direction with respect to the internal gear 20, rattling in the locked state can be prevented.

Further, the reclining device 100 according to the first embodiment does not have a boss portion around the through hole 12 of the external gear 10, and the bush 30 is raised by the raised bottom portion 23 of the internal gear 20. Since it is arranged and directly presses the side surface of the bottom surface of the external gear 10, there is no possibility of pressing the boss portion and damaging the boss portion as in the conventional art. In addition, since the height of the cylindrical boss 22 of the internal gear 20 is raised by the bottom raised bottom portion 23 of the internal gear 20, the height of the cylindrical boss 22 of the internal gear 20 can be made lower than in the conventional case, so that the rigidity of the cylindrical boss portion is also increased. be able to.

(Second embodiment)
An exploded perspective view of the reclining device 100 according to the second embodiment is shown in FIG. A reclining device 100 according to the second embodiment is the same except that a through hole 25 is formed in an internal gear 20 and a cylindrical boss 15 is provided in an external gear 10. Therefore, the explanation is omitted.

As shown in FIG. 7, the external gear 10 is formed in a disk shape, has external teeth 11 formed on its outer peripheral surface, and has a cylindrical boss 15 at its center. The periphery of the cylindrical boss 15 has a raised bottom portion 17 that is raised. The raised bottom surface portion 17 is a portion that makes contact with the bush 30 . The raised bottom surface portion 17 is formed to have a circular outer periphery, and is preferably raised above a position corresponding to the bottom surface of the internal gear 20 (see FIG. 4) when assembled.

The internal gear 20 is formed in a disk shape having a diameter larger than that of the external gear 10, and is formed with a cylindrical recess so that the external gear 10 can be mounted inside. Internal teeth 21 are formed on the peripheral surface. At least one more internal tooth is formed than the number of teeth of the external tooth 11 of the external gear 10, and the external gear 10 and the internal gear 20 are located at the center of the external gear 10 and the internal gear 20, respectively. is meshing with the inner teeth 21 and the outer teeth 11 so as to be eccentric, as in the first embodiment. A through hole 25 is provided at the center of the internal gear 20 as shown in FIG. A boss portion is not provided in the through hole 25 .

The method of moving the reclining device 100 according to the second embodiment is similar to that of the first embodiment. It is biased by a spring 70 in the direction of separation, and contacts the inner peripheral surface of the bush 30 and the outer peripheral surface 15 a of the cylindrical boss 15 of the external gear 10 . Therefore, relative motion between the internal gear 20 and the external gear 10 is locked, and the seat back 220 is in a locked state. When the rotating shaft 40 is rotated counterclockwise from this locked state, first, the driving member 60 fitted to the rotating shaft 40 rotates, and the rotational force of the driving member 60 is transferred from the engaging portion 63 to the projection portion 36 . and the bush 30 rotates. A wedge angle is set between the wedge-shaped cam 50 b and the inner wall of the wedge-shaped cam accommodating portion 35 of the bush 30 , and the wedge-shaped inner wall contacts the wedge-shaped cam 50 . Due to the rotation of the bush 30, a clearance is generated between the wedge-shaped cams 50 on the inner wall of the wedge angle, and the wedge is disengaged. As a result, gaps are generated between the bushing 30 and the cylindrical boss 15 of the external gear 10 and between the bushing 30 and the through hole 25 of the internal gear 20, so that the external gear 10 can rotate with respect to the internal gear 20. Become. Along with this, the biasing force of the spring 70 causes the wedge-shaped cam 50a to rotate counterclockwise so as to fill the gap. The wedge-shaped cam 50 rotates counterclockwise so as to slide together with the rotating shaft 40 and the bushing 30 . Thus, the external gear 10, the internal gear 20 and the rotating shaft 40 constitute a differential gear mechanism. It should be noted that clockwise rotation can also be performed in the same manner. It should be noted that clockwise rotation can also be performed in the same manner.

It should be noted that the present invention is not limited to the above-described embodiments, and can be implemented in various forms within the technical scope of the present invention.

As shown in the above-described embodiment, it can be industrially used mainly as a vehicle seat reclining device.

DESCRIPTION OF SYMBOLS 10... External gear, 10a... Recessed part, 11... External tooth, 12... Through hole, 12a... Inner peripheral surface, 13... Protruding part, 15... Cylindrical boss, 15a... Outer peripheral surface, 16... Standing part, 17... Raised bottom Bottom surface portion 18 Bottom surface 20 Internal gear 21 Internal tooth 22 Cylindrical boss 22a Outer peripheral surface 23 Raised bottom surface 25 Through hole 26 Projection 30 Bush 31 First bush 32 Second bush 33 Outer peripheral surface 35 Wedge-shaped cam receiving portion 36 Protrusion 40 Rotating shaft 41 Serration 42 Shaft 43 Locking portion 50 Wedge-shaped cam 50a Wedge-shaped cam 50b Wedge-shaped cam 51 Concave surface 52 Convex surface 53 Proximity side end 60 Drive member 61 Fitting hole 63 Engagement portion 70 Spring 71 Annular portion 72a, 72b End 80 Plate cover 90 Shaft locking member 100 Reclining device 200 Vehicle seat 210 Seat cushion 220 Seat back 230 Mounting plate for

Claims (4)

A seat reclining device that tiltably holds a seat back frame that forms a seat back with respect to a seat cushion frame that forms a seat cushion,
an external gear that is directly or indirectly attached to one of the seat cushion frame and the seat back frame, has external teeth formed on an outer peripheral surface, and has a through hole coaxial with the axial direction formed on an inner peripheral surface; ,
an internal tooth that is directly or indirectly attached to the other of the seat cushion frame and the seat back frame and that can mesh with the external tooth provided on the inner peripheral surface by at least one more than the external tooth; an internal gear having a cylindrical boss coaxial with the direction, and a bottom upper bottom portion raised above a bottom portion formed around the cylindrical boss;
It is disposed between the inner periphery of the through hole of the external gear and the outer periphery of the cylindrical boss of the internal gear, and is formed into an annular shape by two arcuate members of a first bush and a second bush. a bush formed so that the center of the cylindrical boss is eccentric with the center of the cylindrical boss, and has a wedge-shaped cam accommodating portion on the inner peripheral surface side and a protrusion on the front side;
It is arranged in the wedge-shaped cam accommodating portion of the bushing, and the external gear and the internal gear contact each other by contacting the outer peripheral surface of the cylindrical boss of the internal gear and the inner peripheral surface of the wedge-shaped cam accommodating portion. While restricting relative rotation, the outer peripheral surface of the cylindrical boss of the internal gear and the inner peripheral surface of the through hole of the external gear are slid to allow relative rotation between the external gear and the internal gear. a pair of wedge-shaped cams for
a biasing member that biases the wedge-shaped cams in a direction to separate them;
a drive member that is coaxially and rotatably fitted into the cylindrical boss of the internal gear and has a fitting hole on the inside and a protrusion that engages the protrusion of the bush on the outer peripheral side;
a rotating shaft fitted to the drive member and rotating the bush through the drive member;
with
The reclining device, wherein the bush is in contact with a side surface of the bottom surface of the external gear. 2. The reclining device according to claim 1, wherein the bottom upper bottom surface portion is raised to at least a position corresponding to the bottom surface portion of the external gear. A seat reclining device that tiltably holds a seat back frame that forms a seat back with respect to a seat cushion frame that forms a seat cushion,
It is directly or indirectly attached to one of the seat cushion frame and the seat back frame, has external teeth formed on the outer peripheral surface, and has a cylindrical boss coaxial with the axial direction formed on the inner peripheral surface, and the cylindrical boss is formed on the inner peripheral surface. an externally toothed gear having a bottom and upper bottom portion raised above a bottom portion formed around the periphery;
It is directly or indirectly attached to the other of the seat cushion frame and the seat back frame, and has an internal tooth meshable with the external tooth provided on the inner peripheral surface by at least one more than the external tooth. and an internal gear in which a through hole coaxial with the axial direction is formed;
A first bushing disposed between the inner circumference of the through hole of the internal gear and the outer circumference of the cylindrical boss of the external gear and a second bushing formed into an annular shape by two arcuate members, and the outer peripheral surface of the a bush formed so that the center of the cylindrical boss is eccentric with the center of the cylindrical boss, and has a wedge-shaped cam accommodating portion on the inner peripheral surface side and a protrusion on the front side;
The external gear and the internal gear are arranged in the wedge-shaped cam accommodating portion of the bush and contact the outer peripheral surface of the cylindrical boss of the external gear and the inner peripheral surface of the wedge-shaped cam accommodating portion. while regulating the relative rotation of the external gear and the internal gear by causing the outer peripheral surface of the cylindrical boss of the external gear and the inner peripheral surface of the through hole of the internal gear to slide. a pair of permissive wedge cams;
a biasing member that biases the wedge-shaped cams in a direction to separate them;
a drive member that is coaxially and rotatably fitted into the cylindrical boss of the external gear and has a fitting hole on the inside and a protrusion that engages with the protrusion of the bush on the outer peripheral side;
a rotating shaft fitted to the drive member and rotating the bush through the drive member;
with
A reclining device according to claim 1, wherein the bush is in contact with a side surface of the bottom surface of the internal gear. 4. The reclining device according to claim 3, wherein the bottom upper bottom portion is raised to at least a position corresponding to the bottom portion of the internal gear.

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