JP7680257B2 - Reclining device - Google Patents

Description

The present invention relates to a reclining device.

The right holder has developed a seat reclining device that holds a seat back tiltably relative to a seat cushion, as follows:
a first frame fixed to either the seat cushion or the seat back;
a second frame fixed to the other of the seat cushion and the seat back;
an external gear connected to the first frame and having external teeth formed on an outer circumferential surface thereof;
an internal gear connected to the second frame and capable of meshing with the external teeth, the internal teeth being greater in number than the external teeth;
a rotation shaft that is coaxially and rotatably fitted to the external gear and that causes one of the external gear and the internal gear to revolve around a gear shaft of the other external gear,
The external gear is formed with an external tooth side restriction portion extending in the axial direction from a vicinity of a part of the external teeth,
A reclining device has been proposed in which the internal gear has an internal tooth side regulating portion formed near a portion of the internal teeth that abuts against the external tooth side regulating portion at a predetermined relative rotation regulating position when the external tooth gear and the internal gear rotate relative to each other, thereby regulating the relative rotation within a certain range (Patent Document 1).

However, as shown in FIG. 8, when a large force is applied to the cam 330 or the ring 340, the cam 330 or the ring 340 exerts a force that causes the boss 350 to fall, and a large load is applied to the base of the boss 350, causing the boss 350 to deform and fall.

JP 2011-207253 A

The present invention was made in consideration of these problems, and aims to provide a reclining device that prevents a force from being applied to the cylindrical boss in a direction that would cause the ring or cam to tilt the boss, reduces deformation caused by the force applied by the cam or ring, and maintains its strength.

To achieve the above-mentioned objectives, the present invention adopts the following measures.

The reclining device of the present invention is a seat reclining device that holds a seat back frame constituting a seat back so as to be tiltable relative to a seat cushion frame constituting a seat cushion,
an externally toothed gear attached directly or indirectly to one of the seat cushion frame and the seat back frame, the externally toothed gear having external teeth formed on an outer peripheral surface and a through hole formed coaxially with the axial direction on an inner peripheral surface;
an internal gear that is directly or indirectly attached to the other of the seat cushion frame and the seat back frame, that has internal teeth that are at least one more than the external teeth on an inner circumferential surface and that can mesh with the external teeth, and that has a cylindrical boss that is coaxial with the axial direction;
a rotating bushing including a rotating shaft portion formed coaxially and rotatably on the cylindrical boss of the internal gear, an outer peripheral wall portion having an outer periphery the same as the inner periphery of the through hole of the external gear, and a bottom surface portion disposed between the rotating shaft portion and the outer peripheral wall portion, the center of the rotating shaft portion and the center of the outer peripheral wall portion being formed eccentrically, and a cam accommodating portion being formed between the cylindrical boss and the outer peripheral wall portion;
a pair of wedge-shaped cams that are accommodated in the cam accommodating portion and press against the cylindrical boss of the internal gear and an inner peripheral surface of an outer peripheral wall portion of the rotating bush to restrict relative rotation between the external gear and the internal gear, and that rotate the rotating bush to cause sliding between the rotating bush and the cylindrical boss of the internal gear or between the rotating bush and the inner peripheral surface of the through hole of the external gear to allow relative rotation between the external gear and the internal gear;
an elastic body that biases the pair of wedge-shaped cams in a direction to simultaneously contact the rotating bush and the cylindrical boss;
The present invention is characterized in that it is provided with:

By adopting this configuration, even if an external force is applied to the rotating bush and the wedge-shaped cam, the use of a rotating bush with a bottom surface disposed between the rotating shaft portion and the outer peripheral wall portion prevents the outer peripheral wall portion and the wedge-shaped cam from collapsing, and the load is more easily applied to the base of the cylindrical boss, reducing the amount of collapse of the cylindrical boss and enhancing the rigidity and strength in the direction in which the outer peripheral wall portion and the wedge-shaped cam collapse.

Further, the present invention provides a reclining device for a seat that holds a seat back frame constituting a seat back so as to be tiltable relative to a seat cushion frame constituting a seat cushion, the reclining device comprising:
an externally toothed gear attached directly or indirectly to one of the seat cushion frame and the seat back frame, the externally toothed gear having an outer peripheral surface on which external teeth are formed and an inner peripheral surface on which a cylindrical boss is formed coaxially with the axial direction;
an internal gear that is directly or indirectly attached to the other of the seat cushion frame and the seat back frame, that has internal teeth that are at least one more than the external teeth on an inner circumferential surface and that can mesh with the external teeth, and that has a through hole formed in the center;
a rotating bushing including a rotating shaft portion formed coaxially and rotatably on the cylindrical boss of the external gear, an outer peripheral wall portion having an outer periphery the same as the inner periphery of the through hole of the internal gear, and a bottom surface portion disposed between the rotating shaft portion and the outer peripheral wall portion, the center of the rotating shaft portion and the center of the outer peripheral wall portion being formed eccentrically, and a cam accommodating portion being formed between the cylindrical boss and the outer peripheral wall portion;
a pair of wedge-shaped cams that are accommodated in the cam accommodating portion and press against the cylindrical boss of the external gear and the inner peripheral surface of the outer circumferential wall portion of the rotating bush to restrict relative rotation between the external gear and the internal gear, and that rotate the rotating bush to slide between the rotating bush and the cylindrical boss of the external gear or between the rotating bush and the inner peripheral surface of the through hole of the internal gear to allow relative rotation between the external gear and the internal gear;
an elastic body that biases the pair of wedge-shaped cams in a direction to simultaneously contact the rotating bush and the cylindrical boss;
The present invention is characterized in that it is provided with:

Similarly, with this configuration, even if an external force is applied to the rotating bush and the wedge-shaped cam, the use of a rotating bush with a bottom surface disposed between the rotating shaft portion and the outer peripheral wall portion prevents the outer peripheral wall portion and the wedge-shaped cam from collapsing, and the load is more easily applied to the base of the cylindrical boss, reducing the amount of collapse of the cylindrical boss and enhancing the rigidity and strength in the direction in which the outer peripheral wall portion and the wedge-shaped cam collapse.

The reclining device according to the present invention may also be characterized in that a hole for inserting a wedge-shaped cam is provided at a position on the bottom surface that corresponds to the cam housing portion.

By adopting this configuration, the wedge-shaped cam can be attached through the wedge-shaped cam insertion hole even after the rotating bush is assembled, and the wedge-shaped cam can be replaced during maintenance without removing the rotating bush.

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 a cross-sectional view taken along line AA of FIG. 2 according to the first embodiment. FIG. 5 is a schematic diagram illustrating the rotating bush 30 according to the first embodiment. FIG. 6 is an exploded perspective view of the reclining device 100 according to the second embodiment. FIG. 7 is a front view showing the internal structure of the reclining device 100 according to the second embodiment. FIG. 8 is a cross-sectional view showing the internal structure of a conventional reclining device 300.

The reclining device 100 according to an embodiment of the present invention will be described in detail below with reference to the drawings. FIG. 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, FIG. 3 is an exploded perspective view of the reclining device 100, and FIG. 4 is a cross-sectional view taken along line A-A in FIG. 2. Note that the embodiments and drawings described below are intended to exemplify some of the embodiments of the present invention, and are not to be used to limit the present invention to these configurations. Note that corresponding components in each drawing are denoted by the same or similar reference numerals.

First Embodiment
1, the reclining device 100 according to the first embodiment is a device that is attached to a seat cushion 210 of a vehicle seat 200 and a center position of the tilt of a seat back 220 that is tiltably attached to the seat cushion 210, and that provides a tilting function to the seat back 220. Specifically, the reclining device 100 is used by being attached between a seat cushion frame arranged inside the seat cushion 210 and a seat back frame arranged inside the seat back 220 directly or indirectly via another attachment plate 230 (hereinafter referred to as a "mounting plate or the like").

As shown in Figures 2 and 3, the reclining device 100 according to the present invention mainly comprises an external gear 10, an internal gear 20, a rotating bush 30, a pair of wedge-shaped cams 50a, 50b (50), a spring 60 as an elastic body, a spring cover 70, and a plate cover 80. Note that in Figure 2, the spring cover 70 and the plate cover 80 are omitted to make the internal structure easier to see.

As shown in FIG. 3, the external gear 10 is formed in a disk shape, with external teeth 11 formed on the outer periphery and a cylindrical through hole 12 formed in the center. The external gear 10 has a protrusion 13 on the outer surface 10b, and the external gear 10 is attached by welding or the like in a state where it fits into a fitting hole provided in a mounting plate or the like 230.

The internal gear 20 is formed in a disk shape having a larger diameter than the external gear 10, and a cylindrical recess is formed so that the external gear 10 can be attached inside, and the internal teeth 21 are formed on the inner peripheral surface of the recess. The internal teeth 21 are formed at least one more 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 engaged with the internal teeth 21 and the external teeth 11 so that the center _C2 of the external gear 10 and the center _C1 of the internal gear 20 are eccentric, as shown in FIG. 2. Therefore, the external gear 10 and the internal gear 20 form a differential gear, and when the internal gear 20 makes one revolution around the external teeth 11, the rotation proceeds by the difference between the teeth of the internal teeth 21 and the external teeth 11. That is, for example, if there is only one difference in tooth, when the external gear 10 makes one revolution 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. 3, the internal gear 20 is also provided with a protrusion 23 on its outer surface, which is fitted into a fitting hole provided in a mounting plate or the like 230 and attached by welding or the like.

The rotating bush 30 has a rotating shaft portion 31 formed coaxially and rotatably on the cylindrical boss 22 of the internal gear 20, a cylindrical outer circumferential wall portion 32 disposed between the inner circumferential surface 12a of the through hole 12 of the external gear 10 and the outer circumferential surface 22a of the cylindrical boss 22 of the internal gear 20, and a bottom surface portion 33 supporting the rotating shaft portion 31 and the outer circumferential wall portion 32. The rotating shaft portion 31 is driven to rotate when adjusting the tilt of the seat back 220, and has an inner cylinder provided with serrations 31a for receiving the rotational force of the tilt motor. As shown in FIG. 5B, the rotating bush 30 is formed in a ring shape in which the center _C3 of the inner circumferential surface 32b of the outer circumferential wall portion 32 is eccentric (γ) from the center _C4 relative to the outer circumferential surface 32a. The inner peripheral surface 32b of the outer peripheral wall portion 32 has a diameter slightly larger than that of the outer peripheral surface 22a of the cylindrical boss 22 of the internal gear 20, and the outer peripheral surface 32a of the outer peripheral wall portion 32 is formed to have a diameter slightly smaller than that of the through hole 12 of the external gear 10. In the locked state, a gap A is formed between the inner peripheral surface 32b of the outer peripheral wall portion 32 and the outer peripheral surface 22a of the cylindrical boss 22. The gap A is preferably set to approximately 0.06 mm to 0.12 mm. A gap B is formed between the outer peripheral surface 32a of the rotating bush 30 and the through hole 12 of the external gear 10. The gap B is preferably set to approximately 0.02 mm to 0.06 mm. At this time, in order to mesh the external gear 10 and the internal gear 20, the relationship between the gap A and the gap B needs to be gap A>gap B. That is, the gap A between the outer peripheral surface 22a of the cylindrical boss 22 of the internal gear 20 and the inner peripheral surface 32b of the rotating bush 30 is set to be larger than the gap B between the inner peripheral surface 12a of the through hole 12 of the external gear 10 and the outer peripheral surface 32a of the rotating bush 30. The bottom surface portion 33 is a member that connects the rotating shaft portion 31 and the outer peripheral wall portion 32 to each other, and has the function of maintaining the relative positions of the rotating shaft portion 31 and the outer peripheral wall portion 32, as well as the function of preventing the outer peripheral wall portion 32 from deforming so as to fall when a force is applied to the outer peripheral wall portion 32.

Two cam accommodating sections 34 are formed on the inner peripheral surface 32b of the outer peripheral wall portion 32 so that the gap between them gradually narrows from the opposing side. A pair of wedge-shaped cams 50a and 50b (50) are provided in the cam accommodating section 34 so as to contact the inner peripheral surface of the cam accommodating section 34 and the outer peripheral surface 22a of the cylindrical boss 22 of the internal gear 20. The wedge-shaped cams 50a and 50b are formed symmetrically with respect to the plane as shown in FIG. 3, and the concave surface 51 (inner surface) of the wedge-shaped cam 50 has the same curved surface as the curved surface of the outer peripheral surface 22a of the cylindrical boss 22, and the convex surface 52 (outer surface) is formed so that the thickness gradually becomes thinner from the opposing side. The cam accommodating sections 34 are provided on both sides of the thickest part α of the rotating bush 30. The thickest part has an extension 46 extending toward the outer peripheral surface 22a of the cylindrical boss 22. In addition, holes 35a, 35b (35) for inserting the wedge-shaped cam may be provided at a position on the bottom surface 33 corresponding to the cam housing portion 34 so that the wedge-shaped cam 50 can be attached to the cam housing portion 34 after the rotating bush 30 is assembled, and can be removed during maintenance.

As shown in FIG. 3, the spring 60 has an annular portion 61 and ends 62a, 62b that rise up from the annular portion 61 so as to be bent 90 degrees. The ends 62a, 62b are arranged on the end faces of the thick portions of the wedge-shaped cams 50a and 50b, and are biased in the direction in which the wedge-shaped cams 50a and 50b move away from each other. This allows the external gear 10 to be pressed against the internal gear 20 and meshed with it. The spring 60 may be made of other elastic material such as rubber, as long as it is capable of biasing the wedge-shaped cams 50a and 50b.

The spring cover 70 is a cover that holds the spring 60 so that it does not come off, and is not particularly limited as long as it is capable of holding the spring 60.

The plate cover 80 is made of a metal plate formed into an annular shape and is fixed to the outer end of the internal gear 20 by welding or other means, and has the function of restricting the axial movement of the external gear 10.

The reclining device 100 thus manufactured operates as follows. When no force is applied to the rotating shaft portion 31 and it is not rotating, i.e., when the rotating bush 30 is not rotating, the pair of wedge-shaped cams 50a and 50b are biased by the spring 60 in the direction of moving apart, and are in contact with the inner peripheral surface 32b of the rotating bush 30 and the outer peripheral surface 22a of the cylindrical boss 22 of the internal gear 20. Therefore, the relative movement between the internal gear 20 and the external gear 10 is locked, and the seat back 220 is in a locked state.

2, the rotating bush 30, which is integral with the rotating shaft portion 31, also rotates in the same manner. A wedge angle is set on the inner wall of the cam accommodating portion 34 of the rotating bush 30, and the wedge angle inner wall is in contact with the wedge-shaped cam 50. As the rotating bush 30 rotates, a gap is generated between the wedge angle inner wall and the wedge-shaped cam 50, and the wedge is removed. The rotating bush 30 rotates counterclockwise relative to the internal gear 20, and as a result, a gap is generated between the rotating bush 30 and the cylindrical boss 22 and between the rotating bush 30 and the through hole 12 of the external gear 10, and the external gear 10 becomes rotatable relative to the internal gear 20. Accordingly, the wedge-shaped cam 50a rotates counterclockwise to fill the gap due to the biasing force of the spring 60. The wedge-shaped cam 50 rotates counterclockwise to slide together with the rotating bush 30. In this way, the external gear 10, the internal gear 20, and the rotating bush 30 form a differential gear mechanism. Clockwise rotation can also be achieved in the same way.

In the reclining device 100 thus manufactured, the rotating bush 30 is formed in a ring shape, so 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 tries to move in the direction of the external force or the reaction force, but the rotating bush 30 is sandwiched perpendicular to the outer circumferential 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 of the attempted movement, and the component force components are kept to a minimum to function as a bearing, stabilizing the sliding and ensuring smooth rotation.

In addition, even if an external force is applied to the rotating bush 30 and the wedge-shaped cam 50, by using a rotating bush 30 having a bottom surface portion 33 disposed between the rotating shaft portion 31 and the outer peripheral wall portion 32, the outer peripheral wall portion 32 and the wedge-shaped cam 50 are prevented from falling even if the cylindrical boss 22 falls slightly as shown by arrow C in FIG. 4, and since the load is more easily applied to the base of the cylindrical boss 22, the amount by which the cylindrical boss 22 falls can be reduced, and the rigidity and strength in the direction in which the outer peripheral wall portion 32 and the wedge-shaped cam 50 fall can be increased.

Second Embodiment
The reclining device 100 according to the second embodiment is shown in Fig. 6 or 7. The reclining device 100 according to the second embodiment differs from the reclining device 100 according to the first embodiment in that a cylindrical boss 14 is provided at the center of the external gear 10, and a through hole 25 is provided at the center of the internal gear 20. Also, a spring cover 70 that prevents the rotating bush 30, the wedge-shaped cam 50, and the spring 60 from moving in the axial direction is provided on the outer surface side of the internal gear 20, and this spring cover 70 is provided with a protrusion 71 that fits into a fitting hole of the mounting plate or the like 230. On the other hand, the plate cover 80 is formed of a metal plate formed in an annular shape, is arranged on the outer surface side of the external gear 10, and is fixed to the end of the outer periphery of the internal gear 20 by welding or the like, and restricts the axial movement of the external gear 10.

The rotating bush 30 and the spring 60 are made symmetrical to the first embodiment. The rotating bush 30 has an outer wall portion 32 disposed between the outer circumferential surface 14a of the cylindrical boss 14 of the external gear 10 and the through hole 25 of the internal gear 20. The rotating bush 30 is disposed so as to rotate coaxially with the central axis of the cylindrical boss 14. A pair of wedge-shaped cams 50a and 50b (50) are provided between the inner circumferential surface of the rotating bush 30 and the outer circumferential surface 14a of the cylindrical boss 14 of the external gear 10 so as to contact both. Two cam accommodating portions 34 are formed on the inner circumferential surface of the rotating bush 30 in accordance with the shape of the wedge-shaped cam 50 so that the gap gradually narrows from the opposing side, and the wedge-shaped cam 50 is inserted into the cam accommodating portion 34. The spring 60 has an annular portion 61 and ends 62a, 62b that rise up from the annular portion 61 so as to be bent 90 degrees. The ends 62a, 62b are arranged on the end faces of the thick portions of the wedge-shaped cams 50a and 50b, and are biased in directions that move the wedge-shaped cams 50a and 50b away from each other. This allows the external gear 10 to be pressed against the internal gear 20 and engaged.

The inner peripheral surface 32b of the rotating bush 30 has a diameter slightly larger than the diameter of the outer peripheral surface 14a of the cylindrical boss 14, and in the locked state, a gap A' is formed between the inner peripheral surface 32b of the rotating bush 30 and the outer peripheral surface 14a of the cylindrical boss 14. The gap A' between the inner peripheral surface 32b of the rotating bush 30 and the outer peripheral surface 14a of the cylindrical boss 14 should be set to approximately 0.06 mm to 0.12 mm. In addition, the outer peripheral surface 32a of the rotating bush 30 is disposed in the through hole 25 of the internal gear 20 and is formed to have a diameter slightly smaller than the diameter of the through hole 25 of the internal gear 20, and in the locked state, a gap B' is formed between the outer peripheral surface 32a of the rotating bush 30 and the through hole 25 of the internal gear 20. The gap B' between the outer peripheral surface 32a of the rotating bush 30 and the through hole 25 of the internal gear 20 should be set to approximately 0.02 mm to 0.06 mm. In this case, in order to mesh the external gear 10 and the internal gear 20, the relationship between the gap A' and the gap B' needs to be Gap A' > Gap B'. In other words, the gap B' between the through hole 25 of the internal gear 20 and the rotating bush 30 is set to be smaller than the gap A' between the cylindrical boss 14 of the external gear 10 and the rotating bush 30.

The reclining device 100 thus constructed operates as follows. When no force is applied to the rotating bush 30 and it is not rotating, the pair of wedge-shaped cams 50a and 50b are biased by the spring 60 in the direction away from each other, and are in contact with the outer circumferential surface 14a of the cylindrical boss 14 of the external gear 10. As a result, the relative movement of the internal gear 20 and the external gear 10 is locked, and the seat back 220 is in a locked state.

When the rotating bush 30 is rotated from this locked state, for example, in a counterclockwise direction in FIG. 2, the rotating bush 30, which is integral with the rotating shaft portion 31, also rotates in the same manner. A wedge angle is set on the inner wall of the cam accommodating portion 34 of the rotating bush 30, and the wedge angle inner wall is in contact with the wedge-shaped cam 50. This rotation creates a gap between the wedge angle inner wall and the wedge-shaped cam 50, and the wedge is removed. The rotating bush 30 rotates counterclockwise relative to the internal gear 20, and as a result, a gap is created between the rotating bush 30 and the cylindrical boss 14 and between the rotating bush 30 and the through hole 25 of the internal gear 20, and the external gear 10 becomes rotatable relative to the internal gear 20. Accordingly, the wedge-shaped cam 50a rotates counterclockwise to fill this gap due to the biasing force of the spring 60. The wedge-shaped cam 50 rotates counterclockwise to slide together with the rotating bush 30. In this way, the external gear 10, the internal gear 20, and the rotating bush 30 form a differential gear mechanism. Clockwise rotation can also be achieved in the same way.

In the reclining device 100 thus manufactured, the rotating bush 30 is formed in a ring shape, so 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 tries to move in the direction of the external force or the reaction force, but the rotating bush 30 is sandwiched perpendicular to the outer circumferential surface 14a of the cylindrical boss 14 of the external gear 10 and the through hole 25 of the internal gear 20 in the direction of the attempted movement, and the component force components are kept to a minimum to function as a bearing, stabilizing the sliding and ensuring smooth rotation.

In addition, even if an external force is applied to the rotating bush 30 and the wedge-shaped cam 50, by using a rotating bush 30 having a bottom surface portion 33 disposed between the rotating shaft portion 31 and the outer peripheral wall portion 32, the outer peripheral wall portion 32 and the wedge-shaped cam 50 are prevented from falling even if the cylindrical boss 22 falls slightly as shown by arrow C in FIG. 4, and since the load is more easily applied to the base of the cylindrical boss 22, the amount by which the cylindrical boss 22 falls can be reduced, and the rigidity and strength in the direction in which the outer peripheral wall portion 32 and the wedge-shaped cam 50 fall can be increased.

In the first and second embodiments described above, the rotating bushing 30 may be formed in an annular or ring shape in which the amount of eccentricity γ between the center _C3 with respect to the outer circumferential surface 43 of the rotating bushing 30 and the center _C4 of the cylindrical boss hole 41 is larger than the amount of eccentricity β between the center C1 of the internal gear ₂₀ and the center _C2 of the external gear 10. In other words, the rotating bushing 30 may be formed so that the amount of eccentricity γ is greater than the amount of eccentricity β.

Each component of the reclining device 100 varies depending on the manufacturing process, and a gap A is formed between the cylindrical boss hole 41 and the outer peripheral surface 22a of the cylindrical boss 22, and a gap B is formed between the external gear 10 and the through hole 12, so that a gap is generated between the external teeth 11 of the external gear 10 and the internal teeth 21 of the internal gear 20 due to the misalignment of the gaps. Therefore, by making the amount of eccentricity between the center _C3 and the center _C4 of the cylindrical boss hole 41 relative to the outer peripheral surface 43 of the rotating bush 30 greater than or equal to the amount of eccentricity between the center _C1 of the internal gear 20 and the center _C2 of the external gear 10, it is possible to reduce the generation of a gap between the external gear 10, the external teeth 11, and the internal teeth 21 of the internal gear 20.

The present invention is not limited to the above-described embodiment, and may be implemented in various forms within the technical scope of the present invention.

As shown in the above-mentioned embodiment, it can be used industrially primarily as a reclining device for vehicle seats.

10...external gear, 10b...outer surface, 11...external teeth, 12...through hole, 12a...inner circumferential surface, 13...projection, 14...cylindrical boss, 14a...outer circumferential surface, 20...internal gear, 20b...outer surface, 21...internal teeth, 22...cylindrical boss, 22a...outer circumferential surface, 23...projection, 25...through hole, 30...rotating bush, 31...rotating shaft portion, 31a...serration, 32...outer circumferential wall portion, 32a...outer circumferential surface, 32b...inner circumferential surface, 33...bottom portion, 34...cam accommodating portion, 35a , 35b, 35...wedge-shaped cam insertion hole, 46...extension portion, 50...wedge-shaped cam, 50a...wedge-shaped cam, 50b...wedge-shaped cam, 51...concave surface, 52...convex surface, 60...spring, 61...annular portion, 62a, 62b...end portion, 70...spring cover, 71...projection portion, 80...plate cover, 100...recliner device, 200...vehicle seat, 210...seat cushion, 220...seat back, 230...mounting plate

Claims (3)

A seat reclining device that holds a seat back frame that constitutes a seat back so as to be tiltable relative to a seat cushion frame that constitutes a seat cushion,
an externally toothed gear attached directly or indirectly to one of the seat cushion frame and the seat back frame, the externally toothed gear having external teeth formed on an outer peripheral surface and a through hole formed coaxially with the axial direction on an inner peripheral surface;
an internal gear that is directly or indirectly attached to the other of the seat cushion frame and the seat back frame, that has internal teeth that are at least one more than the external teeth on an inner circumferential surface and that can mesh with the external teeth, and that has a cylindrical boss that is coaxial with the axial direction;
a rotating bushing having, integrally, a rotating shaft portion formed coaxially and rotatably on the cylindrical boss of the internal gear, an outer peripheral wall portion having an outer periphery the same as the inner periphery of the through hole of the external gear, and a bottom surface portion disposed between the rotating shaft portion and the outer peripheral wall portion , wherein the center of the inner peripheral surface of the outer peripheral wall portion and the center of the outer peripheral wall portion are formed eccentrically, and a cam accommodating portion is formed between the cylindrical boss and the outer peripheral wall portion;
a pair of wedge-shaped cams that are accommodated in the cam accommodating portion and press against the cylindrical boss of the internal gear and the inner peripheral surface of the outer circumferential wall portion of the rotating bush to restrict relative rotation between the external gear and the internal gear, and that rotate the rotating bush to slide between the rotating bush and the cylindrical boss of the internal gear or between the rotating bush and the inner peripheral surface of the through hole of the external gear to allow relative rotation between the external gear and the internal gear;
an elastic body that biases the pair of wedge-shaped cams in a direction to simultaneously contact the rotating bush and the cylindrical boss;
A reclining device comprising: A seat reclining device that holds a seat back frame that constitutes a seat back so as to be tiltable relative to a seat cushion frame that constitutes a seat cushion,
an externally toothed gear attached directly or indirectly to one of the seat cushion frame and the seat back frame, the externally toothed gear having an outer peripheral surface on which external teeth are formed and an inner peripheral surface on which a cylindrical boss is formed coaxially with the axial direction;
an internal gear that is directly or indirectly attached to the other of the seat cushion frame and the seat back frame, that has internal teeth that are at least one more than the external teeth on an inner circumferential surface and that can mesh with the external teeth, and that has a through hole formed in the center;
a rotating bushing having, integrally, a rotating shaft portion formed coaxially and rotatably on the cylindrical boss of the external gear, an outer peripheral wall portion having an outer periphery the same as the inner periphery of the through hole of the internal gear, and a bottom surface portion disposed between the rotating shaft portion and the outer peripheral wall portion , the center of the inner peripheral surface of the outer peripheral wall portion and the center of the outer peripheral wall portion being eccentric, and having a cam accommodating portion between the cylindrical boss and the outer peripheral wall portion;
a pair of wedge-shaped cams that are accommodated in the cam accommodating portion and press against the cylindrical boss of the external gear and the inner peripheral surface of the outer circumferential wall portion of the rotating bush to restrict relative rotation between the external gear and the internal gear, and that rotate the rotating bush to slide between the rotating bush and the cylindrical boss of the external gear or between the rotating bush and the inner peripheral surface of the through hole of the internal gear, thereby allowing relative rotation between the external gear and the internal gear;
an elastic body that biases the pair of wedge-shaped cams in a direction to simultaneously contact the rotating bush and the cylindrical boss;
A reclining device comprising: The reclining device according to claim 1 or 2, characterized in that the bottom surface portion is provided with a hole for inserting a wedge-shaped cam at a position corresponding to the cam housing portion.

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