Reclining device

Abstract

To provide a reclining device capable of filling, with an elastic body, a gap generated by eccentricity between an external tooth gearwheel and an internal tooth gearwheel, by a wedge-shaped cam added to a reclining device, for receiving a load from a gap side.SOLUTION: A reclining device comprises: an external tooth gearwheel 10; an internal tooth gearwheel 20; a ring 30 which is formed in an annular shape by a pair of ring pieces, has a wedge-shaped cam storage part and an elastic member storage part on an inner peripheral surface side, and has a protrusion part on a front surface side; a pair of wedge-shaped cams 50 which allows relative rotation of the external tooth gearwheel and the internal tooth gearwheel; an energization member 70 for energizing the wedge-shaped cams in directions where they separate from each other; an elastic member 75 whose end is inserted into the elastic member storage part, and which has a function as a wedge; a drive member 60; and a rotary shaft 40 which is fitted to the drive member and rotates the ring through the drive member.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a reclining device. [Background technology]

[0002] The right holder has a seat reclining device that holds a seat back tiltably relative to a seat cushion, a first frame fixed to one of the seat cushion and the seat back, and a second frame fixed to the other of the seat cushion and the seat back; an externally toothed gear connected to the first frame, having external teeth formed on its outer circumferential surface and an externally toothed boss portion coaxial with the axial direction on its inner circumferential surface; an internal gear connected to the second frame, having internal teeth formed on an outer circumferential surface thereof so as to be meshable with the external teeth, and having a cylindrical boss portion on an inner circumferential surface thereof which is coaxial with the axial direction; 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 the gear shaft of the other, a pair of wedge-shaped cams that are interposed between the cylindrical boss portion and the externally toothed boss portion, and that simultaneously contact the cylindrical boss portion side and the externally toothed boss portion to restrict rotation between the cylindrical boss portion and the externally toothed boss portion, and that slide at least one of the cylindrical boss portion side and the externally toothed boss portion side to allow rotation between the cylindrical boss portion and the externally toothed boss portion; a spring member that biases the pair of wedge-shaped cams in a direction that simultaneously brings them into contact with the cylindrical boss portion side and the externally toothed boss portion side; a disk-shaped member that rotates in accordance with the rotation of the rotary shaft, the disk-shaped member extending in the axial direction and including a pair of cam pushing blades having tapered contact surfaces that push the pair of wedge-shaped cams in a direction away from contact with at least one of the cylindrical boss portion side and the externally toothed boss portion side; The proposed device includes a leaf spring that presses the disk-shaped member against the pair of wedge-shaped cams and causes the tapered contact surface to contact the pair of wedge-shaped cams, and the spring force is set to be weaker than that of the spring material (Patent Document 1).

[0003] According to this reclining device, the wedge-shaped cam is directly operated by the cam pushing blade of a disk-shaped member that is linked to the rotating shaft, which has the effect of making the rotational resistance between the external gear and the internal gear uniform and allowing the external gear and internal gear to rotate smoothly.

[0004] In this type of reclining device, the wedge-shaped cam only contacts the cylindrical boss over a range of less than halfway around the circumference, so when a large force is applied to the seatback of the vehicle seat, the external force acting on the reclining device can only be absorbed at the contact point between the cylindrical boss and the wedge-shaped cam. Furthermore, because the wedge-shaped cam is pressed against the external gear when locked, pressing the external gear against the internal gear to prevent rattle, a gap is required on the opposite side of the meshing, but this gap makes it difficult to absorb the load from that side. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 2019-127210 Summary of the Invention [Problem to be solved by the invention]

[0006] Therefore, the present invention was made in consideration of these problems, and aims to provide a reclining device that can withstand loads from the gap side by using a wedge-shaped cam applied to the reclining device to fill the gap caused by eccentricity between the external gear and the internal gear with an elastic body. [Means for solving the problem]

[0007] In order to achieve the above object, the present invention employs the following means.

[0008] The reclining device of the present invention comprises: A seat reclining device that tiltably holds a seat back frame that constitutes a seat back 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 attached directly or indirectly to the other of the seat cushion frame and the seat back frame, the internal gear having internal teeth on an inner circumferential surface that are capable of meshing with the external teeth, the internal teeth being at least one more than the external teeth, and the internal gear having a cylindrical boss formed thereon that is coaxial with the axial direction; a ring 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, formed in an annular shape by a pair of ring pieces, and formed so that the center of the outer periphery and the center of the cylindrical boss are eccentric, the ring having a wedge-shaped cam accommodating portion and an elastic member accommodating portion on the inner periphery side and a protrusion on the front side; a pair of wedge-shaped cams that are disposed in the wedge-shaped cam accommodating portion of the ring, and that restrict relative rotation between the external gear and the internal gear by contacting an outer circumferential surface of the cylindrical boss of the internal gear and an inner circumferential surface of the wedge-shaped cam accommodating portion, and allow relative rotation between the external gear and the internal gear by sliding the outer circumferential surface of the cylindrical boss of the internal gear and the inner circumferential surface of the through hole of the external gear; a biasing member that biases the wedge-shaped cams in a direction separating the wedge-shaped cams; an elastic member having an end inserted into the elastic member accommodating portion and functioning as a wedge; a drive member that is coaxially and rotatably fitted into the cylindrical boss of the internal gear, the drive member having an engagement hole on the inside and a protrusion on the outer periphery that engages with the protrusion of the ring; a rotating shaft that is fitted to the driving member and rotates the ring via the driving member; The present invention is characterized by the following.

[0009] In this invention, the external gear and internal gear are prevented from wobbling by meshing together due to the pressure of a wedge-shaped cam when locked. In this case, a gap is required on the side opposite to the meshed side. However, this gap does not effectively absorb the load on the gap side. Therefore, an elastic member accommodating portion is provided on the gap side, and an elastic member is provided in this elastic member accommodating portion so that it functions as a wedge, allowing the elastic member to absorb the load.

[0010] In addition, in the reclining device according to the present invention, A seat reclining device that tiltably holds a seat back frame that constitutes a seat back 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 cylindrical boss formed coaxially with the axial direction on an inner peripheral surface; an internal gear attached directly or indirectly to the other of the seat cushion frame and the seat back frame, the internal gear having internal teeth on an inner circumferential surface that are capable of meshing with the external teeth, the internal teeth being at least one more than the external teeth, and having a through hole formed therein that is coaxial with the axial direction; a ring that is disposed between the inner periphery of the through hole of the internal gear and the outer periphery of the cylindrical boss of the external gear, that is formed in an annular shape by a pair of ring pieces, that is formed so that the center of the outer periphery and the center of the cylindrical boss are eccentric, that has a wedge-shaped cam accommodating portion and an elastic member accommodating portion on its inner periphery side, and that has a protrusion on its front side; a pair of wedge-shaped cams that are disposed in the wedge-shaped cam accommodating portion of the ring, and that restrict relative rotation between the external gear and the internal gear by contacting the outer circumferential surface of the cylindrical boss of the external gear and the inner circumferential surface of the wedge-shaped cam accommodating portion, and allow relative rotation between the external gear and the internal gear by sliding the outer circumferential surface of the cylindrical boss of the external gear and the inner circumferential surface of the through hole of the internal gear; a biasing member that biases the wedge-shaped cams in a direction separating the wedge-shaped cams; an elastic member having an end inserted into the elastic member accommodating portion and functioning as a wedge; a drive member that is coaxially and rotatably fitted into the cylindrical boss of the external gear, and has an engagement hole on the inside and a protrusion on the outer circumferential side that engages with the protrusion of the ring; a rotating shaft that is fitted to the driving member and rotates the ring via the driving member; The present invention is characterized by the following.

[0011] The present invention differs from the above-mentioned invention in that a cylindrical boss is provided on the external gear and a through hole is formed in the internal gear, but similarly, an elastic member accommodating portion is provided on the gap side, and an elastic member is provided in this elastic member accommodating portion so that it functions as a wedge, making it possible for the elastic member to withstand loads. [Brief explanation of the drawings]

[0012] [Figure 1] FIG. 1 is a schematic diagram of a vehicle seat 200 to which a reclining device 100 according to the first embodiment is attached. [Figure 2] FIG. 2 is a front view showing the internal structure of the reclining device 100 according to the first embodiment. [Figure 3] FIG. 3 is an exploded perspective view of the reclining device 100 according to the first embodiment. [Figure 4] FIG. 4 is a cross-sectional view of the reclining device 100 taken along line AA according to the first embodiment. [Figure 5] FIG. 5 is a front view showing the relationship between the ring 30 and the wedge-shaped cam 50 of the reclining device 100 according to the first embodiment. [Figure 6] FIG. 6 is an exploded perspective view of the reclining device 100 according to the second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0013] A 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, and FIG. 3 is an exploded perspective view of the reclining device 100. FIG. 4 is a cross-sectional view taken along line AA in FIG. 2. Note that the embodiments and drawings described below exemplify some of the embodiments of the present invention and are not intended 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. In addition, in FIG. 3, the directions indicated by the arrows in the drawing are referred to as the "front" and "rear," respectively.

[0014] (First embodiment) 1, the reclining device 100 according to the first embodiment is a device attached to a seat cushion 210 of a vehicle seat 200 at a tilting center position of a seat back 220 that is tiltably attached to the seat cushion 210, and provides a tilting function to the seat back 220. Specifically, the reclining device 100 is attached between a seat cushion frame disposed inside the seat cushion 210 and a seat back frame disposed inside the seat back 220, either directly or indirectly via another attachment plate 230 (hereinafter referred to as "attachment plate or the like").

[0015] 2 to 4, the reclining device 100 according to the present invention mainly comprises an external gear 10, an internal gear 20, a ring 30, a rotating shaft 40, a wedge-shaped cam 50, a driving member 60, a wedge spring 70 as a biasing member, a gap spring 75 as an elastic member, a plate cover 80, and a shaft locking member 90. Note that in FIG. 2, the rotating shaft 40 and the driving member 60 are omitted to make the internal structure easier to see.

[0016] 3, the external gear 10 is formed in a disk shape, with external teeth 11 formed on its outer circumferential surface and a through hole 12 formed in its center. The external gear 10 is provided with a protrusion 13, which is fitted into a fitting hole formed in a mounting plate or the like 230 and is attached to the vehicle seat by welding or the like.

[0017] The internal gear 20 is formed in a disk shape with a larger diameter than the external gear 10. A recess 10a is formed so that the external gear 10 can be fitted inside, and internal teeth 21 are formed on the inner circumferential surface of this recess 10a. The number of internal teeth 21 is at least one more than the number of external teeth 11 of the external gear 10. As shown in FIG. 2 , the external gear 10 and the internal gear 20 are eccentrically arranged, as indicated by arrow d, so that they mesh with the internal teeth 21 and the external teeth 11. 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, it rotates by the difference in teeth between the internal teeth 21 and the external teeth 11. That is, for example, if there is a difference in only one tooth, when the external gear 10 makes one revolution around the internal gear 20, it rotates by one tooth. 3, a cylindrical boss 22 is provided at the center of the internal gear 20. This internal gear 20 is provided with a protrusion 23, which is fitted into a fitting hole provided in a mounting plate 230 or the like and is attached to the vehicle seat by welding or the like.

[0018] The ring 30 is an annular member disposed 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 is formed by combining a pair of ring pieces 30a and 30b. As shown in FIG. 5, 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 eccentrically formed so as to be approximately equal to the amount of eccentricity between the center of the external gear 10 and the center of the internal gear 20. Wedge-shaped cam accommodating portions 35 are respectively formed on the inner peripheral sides of the respective ring pieces 30a and 30b. As shown in FIG. 5, a pair of wedge-shaped cams 50 described later are respectively arranged so as to have a gap. The wedge-shaped cam accommodating portion 35 is set with a wedge angle such that the gap between the ring 30 and the cylindrical boss 22 becomes narrower as it moves away from the facing side. Since the ring 30 can be pressed and moved in the eccentric direction by the wedge-shaped cam 50 described later with respect to the external gear 10 and the internal gear 20, it is possible to prevent the occurrence of rattling in the locked state. However, in the locked state (regulated state), since the external gear 10 is pressed and moved upward in FIG. 5 to prevent rattling, a gap e is required on the opposite side of the meshing. However, due to the presence of this gap e, there was a problem that the load from the lower side could not be received by the cylindrical boss 22. Therefore, as shown in FIG. 2, this gap is filled with a gap spring 75 which is an elastic body, and the elastic body is made to function as a wedge so that the load on the lower side can be received. For this purpose, as shown in FIG. 2 or FIG. 5, an elastic member accommodating portion 37 capable of accommodating the gap spring 75 is formed in the ring 30. The gap spring 75 is provided in the vicinity of the side where the gap is formed. Since the gap spring 75 accommodated in the elastic member accommodating portion 37 needs to be released when the ring 30 moves, a wedge angle is set. When the angle between the tangent line of the gap spring 75 disposed in the elastic member accommodating portion 37 and the cylindrical boss 22 and the tangent line of the gap spring 75 and the ring 30 is θ, and the coefficient of friction during movement is μ, it is necessary that μ < tanθ. Considering such a point, the angle θ is preferably 8° to 10°.Furthermore, the ring 30 is provided with protrusions 36 protruding from the front side on each of the pair of ring pieces 30 a and 30 b so that the ring 30 can be moved via a driving member 60 by rotation of the rotary shaft 40 .

[0019] 3 or 5, the wedge-shaped cams 50a and 50b are formed symmetrically with respect to a plane, with the concave surface 51 (inner surface) of the wedge-shaped cam 50 having the same curve as the curved surface of the outer peripheral surface 22a of the cylindrical boss 22, and the convex surface 52 (outer surface) being formed so that the thickness gradually decreases from the opposing side. The wedge-shaped cams 50a and 50b are arranged so that their near-side ends 53, which are the thicker sides, face each other and, as described above, are disposed within the wedge-shaped cam accommodating portion 35 of the ring 30 so as to contact the inner peripheral surface 12a of the through hole 12 of the external gear 10.

[0020] 3, the wedge spring 70 serving as a biasing member is made of an elastic body and has an annular portion 71 and end portions 72a and 72b that rise up and bend at 90 degrees from the annular portion 71. The end portions 72a and 72b each contact the proximal end portion 53 of the wedge-shaped cam 50, and bias the pair of wedge-shaped cams 50a and 50b in directions that move them apart.

[0021] Gap spring 75 serving as an elastic member is also made of an elastic body and has an annular portion 76 and end portions 76a and 76b that rise up so as to be bent at 90 degrees from annular portion 76. End portions 76a and 76b are each inserted into elastic member accommodating portion 37 and are biased in a direction in which they function as wedges. In this embodiment, end portions 76a and 76b are biased in a direction in which they approach each other.

[0022] The rotating shaft 40 is arranged coaxially and rotatably relative to the cylindrical boss 22 of the internal gear 20. The rotating shaft 40 is driven to rotate when adjusting the tilt of the seat back 220, and has serrations 41 on its inner cylindrical surface to receive the rotational force of the tilt motor. The rotating shaft 40 has a cylindrical shaft portion 42 that is inserted into a drive member 60 (described later), and is provided with a plurality of locking portions 43 that rotate synchronously with the drive member 60.

[0023] The drive member 60 has a fitting hole 61 formed on its inner periphery to fit into the locking portion 43 of the rotary shaft 40, and is rotated in conjunction with the rotation of the rotary shaft 40. The drive member 60 also has engagement portions 63 formed to sandwich the protrusions 36 provided on the ring 30 from both sides, and the drive member 60, which is rotated by the rotation of the rotary shaft 40, can rotate by pressing the protrusions 36 of the ring 30 with the engagement portions 63.

[0024] The plate cover 80 is a member that secures the external gear 10, internal gear 20, ring 30, rotating shaft 40, ring 30, wedge-shaped cam 50, driving member 60, wedge spring 70, and gap spring so that they do not come off, and its shape is not particularly limited.

[0025] The shaft locking member 90 is a member that fixes the rotary shaft 40.

[0026] The reclining device 100 thus constructed operates as follows. When no force is applied to the rotating shaft 40 and the rotating shaft 40 is not rotating, the wedge spring 70 biases the pair of wedge-shaped cams 50a and 50b in directions separating them. This causes the outer peripheral surface 22a of the cylindrical boss 22 of the internal gear 20 to press against the wedge-shaped cam housing portion 35 of the ring 30, bringing the ring 30 into pressing contact with the inner peripheral surface 12a of the through-hole 12 of the external gear 10. This locks the relative movement of the internal gear 20 and the external gear 10, and the seat back 220 is in a locked state. In this locked state, a gap e is formed on the opposite side of the meshing pressure direction. However, because the gap spring 75 is housed in the elastic member housing portion 37 so as to abut against it, it can withstand a downward load.

[0027] From this locked state, if the rotating shaft 40 is rotated counterclockwise, as shown in FIG. 2 , the driving member 60 fitted to the rotating shaft 40 rotates first. The torque of the driving member 60 is transmitted from the engaging portion 63 to the protrusion 36, causing the ring 30 to rotate. A wedge angle is set between the wedge-shaped cam 50b and the inner wall of the wedge-shaped cam housing portion 35 of the ring 30, and the inner wall of the wedge angle is in contact with the wedge-shaped cam 50. As the ring 30 rotates, a gap is created between the inner wall of the wedge angle and the wedge-shaped cam 50, causing the wedge to disengage. Similarly, the gap spring 75, which functions similarly to a wedge, is also released. As a result, gaps are created between the ring 30 and the cylindrical boss 22 and between the ring 30 and the through-hole 12 of the internal gear 20, allowing the external gear 10 to rotate relative to the internal gear 20. Accordingly, the wedge-shaped cam 50a rotates counterclockwise due to the biasing force of the wedge spring 70, filling the gap. The wedge-shaped cam 50 rotates counterclockwise, sliding together with the rotating shaft 40 and ring 30. In this way, the external gear 10, the internal gear 20, and the rotating shaft 40 constitute a differential gear mechanism. Clockwise rotation can also be achieved in the same way.

[0028] In the reclining device 100 manufactured in this manner, the ring 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 will try to move in the direction of the external force or the reaction force.However, in the direction of the attempted movement, the ring is sandwiched perpendicular to the outer surface 22a of the cylindrical boss 22 of the internal gear 20 and the through hole 12 of the external gear 10, and the component force components are minimized, acting as a bearing, stabilizing sliding and ensuring smooth rotation.

[0029] Furthermore, when the rotating shaft 40 is rotated, the engagement portion 63 of the ring 30 engages with the protrusion 36 of the ring 30 in the rotational direction, with no gap, so the gear mechanism can be operated immediately without any time lag. At this time, the ring 30 rotates by being transmitted from the engagement portion 63 to the protrusion 36, so that it rotates to follow the eccentric direction of the internal gear 20 and the external gear 10. During rotation, the ring 30 contacts most of the outer circumferential surface 22a of the cylindrical boss 22, stabilizing the sliding and ensuring smooth rotation. Meanwhile, the wedge-shaped cam 50 biases the external gear 10 to move in the eccentric direction relative to the internal gear 20, preventing rattle in the locked state. Even in the locked state, the gap spring 75 is housed in the elastic member housing 37 so as to abut against it, so that it can withstand a load from the gap side.

[0030] (Second embodiment) An exploded perspective view of a reclining device 100 according to the second embodiment is shown in Figure 6. The reclining device 100 according to the second embodiment is the same as the first embodiment except that a through hole 25 is formed in the internal gear 20 and a cylindrical boss 15 is provided on the external gear 10, and therefore a description thereof will be omitted.

[0031] As shown in FIG. 6, the external gear 10 is formed in a disk shape, with external teeth 11 formed on the outer circumferential surface and a cylindrical boss 15 provided in the center.

[0032] The internal gear 20 is formed in the shape of a disk with a larger diameter than the external gear 10, and has a cylindrical recess formed therein so that the external gear 10 can be fitted inside, with internal teeth 21 formed on the inner circumferential surface of this recess. The number of internal teeth is at least one more than the number of external teeth 11 of the external gear 10, and the external gear 10 and internal gear 20 are engaged with the internal teeth 21 and external teeth 11 so that the centers of the external gear 10 and internal gear 20 are eccentric, respectively, as in the first embodiment. A through hole 25 is provided in the center of the internal gear 20, as shown in FIG. 6.

[0033] As in the first embodiment, the reclining device 100 according to the second embodiment can be moved in the following manner: when no force is applied to the rotating shaft 40 and the rotating shaft 40 is not rotating, the pair of wedge-shaped cams 50a and 50b are biased by the wedge spring 70 in directions separating them, and the inner circumferential surface of the ring 30 is in contact with the outer circumferential surface 15a of the cylindrical boss 15 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 shaft 40 is rotated counterclockwise from this locked state, the drive member 60 fitted to the rotating shaft 40 first rotates, and the rotational force of the drive member 60 is transmitted from the engagement portion 63 to the protrusion 36, causing the ring 30 to rotate. A wedge angle is set between the wedge-shaped cam 50b and the inner wall of the wedge-shaped cam housing portion 35 of the ring 30, and the inner wall of the wedge angle contacts the wedge-shaped cam 50. As the ring 30 rotates, a gap is created between the wedge-angle inner wall and the wedge-shaped cam 50, causing the wedge to disengage. As a result, gaps are created between the ring 30 and the cylindrical boss 15 of the external gear 10 and between the ring 30 and the through-hole 25 of the internal gear 20, allowing the external gear 10 to rotate 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 wedge spring 70. The wedge-shaped cam 50 rotates counterclockwise, sliding together with the rotating shaft 40 and the ring 30. In this way, the external gear 10, the internal gear 20, and the rotating shaft 40 constitute a differential gear mechanism. Clockwise rotation is also possible in the same manner. Clockwise rotation can also be achieved in the same manner.

[0034] The present invention is not limited to the above-described embodiment, and can be embodied in various forms as long as they fall within the technical scope of the present invention. [Industrial Applicability]

[0035] As shown in the above-described embodiment, the present invention is industrially applicable mainly as a reclining device for a vehicle seat. [Explanation of symbols]

[0036] 10...external gear, 10a...recess, 11...external teeth, 12...through hole, 12a...inner peripheral surface, 13...protrusion, 15...cylindrical boss, 15a...outer peripheral surface, 20...internal gear, 21...internal teeth, 22...cylindrical boss, 22a...outer peripheral surface, 23...protrusion, 25...through hole, 30...ring, 30a, 30b...ring pieces, 33...outer peripheral surface, 35...wedge-shaped cam accommodating portion, 36...protrusion, 37...elastic member accommodating portion, 40...rotating shaft, 41...serration, 42...shaft portion, 43...engaging portion, 50...wedge-shaped cam, 50 a...wedge-shaped cam, 50b...wedge-shaped cam, 51...concave surface, 52...convex surface, 53...proximal end, 60...drive member, 61...fitting hole, 63...engagement portion, 70...wedge spring, 71...annular portion, 72a, 72b...end, 75...gap spring, 76...annular portion, 76a...end, 76b...end, 80...plate cover, 90...shaft locking member, 100...recliner, 200...vehicle seat, 210...seat cushion, 220...seat back, 230...mounting plate

Claims

1. A seat reclining device that tiltably holds a seat back frame that constitutes a seat back 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 attached directly or indirectly to the other of the seat cushion frame and the seat back frame, the internal gear having internal teeth on an inner circumferential surface that are capable of meshing with the external teeth, the internal teeth being at least one more than the external teeth, and the internal gear having a cylindrical boss formed coaxially with the axial direction; a ring 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, formed in an annular shape by a pair of ring pieces, and formed so that the center of the outer periphery and the center of the cylindrical boss are eccentric, the ring having a wedge-shaped cam accommodating portion and an elastic member accommodating portion on the inner periphery side and a protrusion on the front side; a pair of wedge-shaped cams that are disposed in the wedge-shaped cam accommodating portion of the ring, and that restrict relative rotation between the external gear and the internal gear by contacting an outer circumferential surface of the cylindrical boss of the internal gear and an inner circumferential surface of the wedge-shaped cam accommodating portion, and allow relative rotation between the external gear and the internal gear by sliding the outer circumferential surface of the cylindrical boss of the internal gear and an inner circumferential surface of the through hole of the external gear; a biasing member that biases the wedge-shaped cams in a direction separating the wedge-shaped cams; an elastic member whose end is inserted into the elastic member accommodating portion and which is biased in a direction that functions as a wedge so as to prevent a gap from being formed in the elastic member accommodating portion in order to receive a load from the opposite side of the meshing between the external gear and the internal gear; a drive member that is coaxially and rotatably fitted into the cylindrical boss of the internal gear, the drive member having an engagement hole on the inside and a protrusion on the outer periphery that engages with the protrusion of the ring; a rotating shaft that is fitted to the driving member and rotates the ring via the driving member; A reclining device comprising:

2. A seat reclining device that tiltably holds a seat back frame that constitutes a seat back 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 cylindrical boss formed coaxially with the axial direction on an inner peripheral surface; an internal gear attached directly or indirectly to the other of the seat cushion frame and the seat back frame, the internal gear having internal teeth on an inner circumferential surface that are capable of meshing with the external teeth, the internal teeth being at least one more than the external teeth, and having a through hole formed therein that is coaxial with the axial direction; a ring that is disposed between the inner periphery of the through hole of the internal gear and the outer periphery of the cylindrical boss of the external gear, that is formed in an annular shape by a pair of ring pieces, that is formed so that the center of the outer periphery and the center of the cylindrical boss are eccentric, that has a wedge-shaped cam accommodating portion and an elastic member accommodating portion on its inner periphery side, and that has a protrusion on its front side; a pair of wedge-shaped cams that are arranged in the wedge-shaped cam accommodating portion of the ring, and that restrict relative rotation between the external gear and the internal gear by contacting the outer circumferential surface of the cylindrical boss of the external gear and the inner circumferential surface of the wedge-shaped cam accommodating portion, and allow relative rotation between the external gear and the internal gear by sliding the outer circumferential surface of the cylindrical boss of the external gear and the inner circumferential surface of the through hole of the internal gear; a biasing member that biases the wedge-shaped cams in a direction separating the wedge-shaped cams; an elastic member whose end is inserted into the elastic member accommodating portion and which is biased in a direction that functions as a wedge so as to prevent a gap from being formed in the elastic member accommodating portion in order to receive a load from the opposite side of the meshing between the external gear and the internal gear; a drive member that is coaxially and rotatably fitted into the cylindrical boss of the external gear, and has an engagement hole on the inside and a protrusion on the outer circumferential side that engages with the protrusion of the ring; a rotating shaft that is fitted to the driving member and rotates the ring via the driving member; A reclining device comprising:

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