Reclining device

Abstract

To provide a reclining device which enables a bush to borne over the whole circumference, and can stabilize slide by receiving force with the bush even when the force is an external force from any direction of 360° .SOLUTION: A reclining device 100 includes: an external tooth gear 10; an internal tooth gear 20; a rotary shaft 30 which is coaxially and rotatably fit and inserted into a boss of the internal tooth gear; the bush 40 which has a cam storage part on its inner peripheral side and is rotated accompanying rotation of the rotary shaft; a pair of wedge-shaped cams 50; and an elastic body for energizing the pair of wedge-shaped cams to a side where the cams are simultaneously brought into contact with the bush and the cylindrical boss, wherein the whole of the cam storage part 44 and the wedge-shaped cams 50 is arranged on a side opposite to a press direction rather than a normal line at the center of the rotary shaft 50 with respect to the engagement direction of each tooth of the internal tooth gear 20 and the external tooth gear 10.SELECTED DRAWING: Figure 2

Description

Technical Field

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

Background Art

[0002] The present applicant has proposed a reclining device for a seat that tiltably holds a seat back with respect to a seat cushion, 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 its outer peripheral surface and an external tooth boss portion coaxial with the axial direction on its inner peripheral surface, an internal gear connected to the second frame and having internal teeth formed on its outer peripheral surface that can mesh with the external teeth and a cylindrical boss portion coaxial with the axial direction on its inner peripheral surface, a rotating shaft that is coaxially and rotatably fitted to the external gear and that revolves either the external gear or the internal gear around the other gear shaft, a pair of wedge-shaped cams inserted between the cylindrical boss portion and the external tooth boss portion, simultaneously contacting the cylindrical boss portion side and the external tooth boss portion to restrict the rotation of the cylindrical boss portion and the external tooth boss portion, and sliding at least one of the cylindrical boss portion side and the external tooth boss portion side to allow the rotation of the cylindrical boss portion and the external tooth boss portion, a spring member that biases the pair of wedge-shaped cams in a direction to simultaneously contact the cylindrical boss portion side and the external tooth boss portion side, a disk-shaped member that rotates with the rotation of the rotating shaft, extends in the axial direction, and has a pair of cam pressing wings provided with a taper on a contact surface that pushes the pair of wedge-shaped cams in a direction to be non-contact with at least one of the cylindrical boss portion side and the external tooth boss portion side, a leaf spring that presses the disk-shaped member against the pair of wedge-shaped cams and brings the tapered contact surface into contact with the pair of wedge-shaped cams, and the biasing force is set weaker than that of the spring member (Patent Document 1).

[0003] According to such a reclining device, since the wedge-shaped cam is directly actuated by the cam pushing blade of the disk-shaped member interlocked with the rotating shaft, the rotational resistance between the external gear and the internal gear becomes uniform, and the rotation of the external gear and the internal gear can be made smooth, which has the effect.

[0004] Since such a reclining device only contacts the wedge-shaped cam with respect to the bush, when a large force is applied to the seat back of the vehicle seat, the force can only be received at the contact portion between the bush and the wedge-shaped cam with respect to the external force applied to the reclining device. There was a problem. Therefore, a large force is partially applied depending on the direction of the applied external force. For example, when the force has to be received by the gear teeth, in the case of a reclining device that is a differential gear, there is a problem that it may not be possible to slide and rotate smoothly.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] Therefore, the present invention has been made in view of such problems, and by enabling the bush to bear over the entire circumference, the bush can receive the force regardless of the direction from which the external force is applied at 360°, so that the sliding can be stabilized. Another object is to provide a reclining device that can efficiently receive the force applied to the bush and the cylindrical boss from the meshing portion between the external gear and the internal gear.

Means for Solving the Problems

[0007] To achieve the above object, the present invention adopts the following means.

[0008] The reclining device of the present invention is a seat reclining device that tiltably holds a seat back frame constituting a seat back with respect to a seat cushion frame constituting 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 thereof, and has a cylindrical boss coaxial with an axial direction formed on an inner peripheral surface thereof; an internal gear that is directly or indirectly attached to the other of the seat cushion frame and the seat back frame, has internal teeth meshing with the external teeth provided at least one or more more than the external teeth, and has a through hole coaxial with the axial direction formed therein; a rotating shaft that is coaxially and rotatably inserted into the cylindrical boss of the external gear and rotates one of the external gear and the internal gear about the gear shaft of the other; a bush that is disposed between an inner periphery of the through hole of the internal gear and an outer periphery of the cylindrical boss of the external gear, is formed in an annular shape with an eccentricity between a center of an outer peripheral surface and a center of an inner peripheral surface, has a cam accommodating portion on an outer peripheral side, and rotates with rotation of the rotating shaft; a pair of wedge-shaped cams that are accommodated in the cam accommodating portion, press the through hole of the internal gear and the bush to bring the bush into contact with an outer peripheral surface of the cylindrical boss of the external gear, thereby restricting relative rotation between the external gear and the internal gear, and by rotating the rotating shaft, sliding an outer peripheral surface of the cylindrical boss of the external gear or an inner peripheral surface of the through hole of the internal gear between the bush and the external gear and the internal gear to allow relative rotation between the external gear and the internal gear; and an elastic body that biases the pair of wedge-shaped cams to simultaneously contact the bush and the cylindrical boss. The entire cam accommodating portion and the wedge-shaped cams disposed in the cam accommodating portion are A normal line passing through the center of the rotating shaft and parallel to the rotating surface of the external gear with respect to the line connecting the center of the rotating shaft and the center of the internal gearIt is characterized by being arranged on the side opposite to the pressing direction.

[0009] By adopting such a configuration, it is possible to bear on almost the entire circumference by means of the bush and the wedge-shaped cam. Therefore, no matter from which direction of 360° an external force is applied, the bush can receive the force, so that the sliding can be stabilized. Further, when a force is applied from the meshing part of the internal gear to the external gear, there is no cam accommodation part or wedge-shaped cam arranged between the outer peripheral surface pressing the inner peripheral surface of the through hole of the internal gear and the direction in which the force is applied, and the entire half circumference of the inner peripheral surface of the through hole of the external gear to which the force is applied can receive the load by the entire half circumference of the outer peripheral surface of the bush. Therefore, it can bear a high strength load.

[0010] Further, the reclining device according to the present invention is a reclining device for a seat that tiltably holds a seat back frame constituting a seat back with respect to a seat cushion frame constituting 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 the outer peripheral surface, and has a cylindrical boss coaxial with the axial direction formed on the 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, has internal teeth meshing with at least one or more of the external teeth provided on the inner peripheral surface, and has a through hole coaxial with the axial direction formed; a rotating shaft that is coaxially and rotatably inserted into the cylindrical boss of the external gear, and rotates one of the external gear or the internal gear around the gear shaft of the other; a bush that is arranged between the inner periphery of the through hole of the internal gear and the outer periphery of the cylindrical boss of the external gear, is formed in an annular shape with the center of the outer peripheral surface and the center of the inner peripheral surface being eccentric, has a cam accommodation part on the inner peripheral side, and rotates with the rotation of the rotating shaft; Accommodated in the cam housing portion, by pressing the cylindrical boss of the external gear and the bush to bring the bush into contact with the inner peripheral surface of the through hole of the internal gear, the relative rotation of the external gear and the internal gear is restricted, and by rotating the rotary shaft, the outer peripheral surface of the cylindrical boss of the bush and the external gear or the inner peripheral surface of the through hole of the bush and the internal gear are slid to allow relative rotation of the external gear and the internal gear, a pair of wedge-shaped cams, An elastic body that biases the pair of wedge-shaped cams to simultaneously contact the bush and the cylindrical boss, The entire cam housing portion and the wedge-shaped cams arranged in the cam housing portion are A normal line passing through the center of the rotating shaft and parallel to the rotating surface of the external gear with respect to the line connecting the center of the rotating shaft and the center of the internal gear Characterized in that they are arranged on the side opposite to the pressing direction with respect to the meshing direction of the teeth of the internal gear and the external gear.

[0011] Even with such a configuration of the reclining device, it is possible to support almost all around by the bush and the wedge-shaped cam. Therefore, even when an external force is applied from any direction of 360°, the bush can receive the force, so that the sliding can be stabilized. Also, when a force is applied from the meshing portion from the internal gear to the external gear, between the inner peripheral surface of the through hole of the internal gear and the outer peripheral surface that presses it in the direction in which the force is applied, there is no cam housing portion or wedge-shaped cam arranged, and the entire half circumference of the inner peripheral surface of the through hole of the external gear to which the force is applied can receive the load by the entire half circumference of the outer peripheral surface of the bush. Therefore, it can receive the load with high strength.

[0012] Furthermore, the reclining device according to the present invention Is a reclining device for a seat that tiltably holds a seat back frame constituting a seat back with respect to a seat cushion frame constituting a seat cushion, An external gear directly or indirectly attached to one of the seat cushion frame and the seat back frame, having external teeth formed on the outer peripheral surface and a cylindrical boss coaxial with the axial direction formed on the inner peripheral surface, It is directly or indirectly attached to the other of the seat cushion frame and the seat back frame, has internal teeth that can mesh with the external teeth provided on the inner peripheral surface with at least one more than the external teeth, and an internal gear with a through hole coaxial with the axial direction, A rotating shaft that is coaxially and rotatably inserted into the cylindrical boss of the external gear, and rotates either the external gear or the internal gear around the other gear shaft, It is arranged between the inner periphery of the through hole of the internal gear and the outer periphery of the cylindrical boss of the external gear, is formed in an annular shape with the center of the outer peripheral surface and the center of the inner peripheral surface being eccentric, has a spring accommodation part on the outer peripheral side, and a bush that rotates with the rotation of the rotating shaft, It is accommodated in the spring accommodation part, presses the through hole of the internal gear and the bush to bring the bush into contact with the outer peripheral surface of the cylindrical boss of the external gear, thereby restricting the relative rotation between the external gear and the internal gear, and by rotating the rotating shaft, it slides the outer peripheral surface of the cylindrical boss of the bush and the external gear or the inner peripheral surface of the through hole of the bush and the internal gear to allow the relative rotation between the external gear and the internal gear. It has a pair of end parts, and the end parts are provided with an elastic body that biases towards the side of contacting the bush and the cylindrical boss simultaneously, The entire spring accommodation part and the pair of end parts arranged in the spring accommodation part are arranged on the side opposite to the pressing direction with respect to the meshing direction of the teeth of the internal gear and the external gear, A normal line passing through the center of the rotating shaft and parallel to the rotating surface of the external gear with respect to the line connecting the center of the rotating shaft and the center of the internal gear Characterized in that it is arranged on the side opposite to the pressing direction.

[0013] By adopting such a configuration, it is possible to provide a simple reclining device by omitting the cam while achieving the above-described effects.

[0014] Furthermore, the reclining device according to the present invention, Is a reclining device for a seat that tiltably holds a seat back frame constituting a seat back with respect to a seat cushion frame constituting 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 its outer peripheral surface, and has a cylindrical boss coaxial with the axial direction formed on its 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, has internal teeth that can mesh with the external teeth provided at least one or more more than the external teeth on its inner peripheral surface, and has a through hole coaxial with the axial direction formed therein; A rotating shaft that is coaxially and rotatably inserted into the cylindrical boss of the external gear, and rotates either the external gear or the internal gear about the gear shaft of the other; An annular-shaped bush 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, has the centers of its outer peripheral surface and inner peripheral surface eccentric, has a spring accommodating portion on the inner peripheral side, and rotates as the rotating shaft rotates; An elastic body that is accommodated in the spring accommodating portion, presses the cylindrical boss of the external gear and the bush, contacts the bush with the inner peripheral surface of the through hole of the internal gear, thereby restricting relative rotation between the external gear and the internal gear, and by rotating the rotating shaft, slides the outer peripheral surface of the cylindrical boss of the external gear or the inner peripheral surface of the through hole of the internal gear of the bush and the bush to allow relative rotation between the external gear and the internal gear, and has a pair of end portions that are biased in a direction of contacting the bush and the cylindrical boss simultaneously; The entire spring accommodating portion and the pair of end portions disposed in the spring accommodating portion are disposed on the side opposite to the pressing direction with respect to the meshing direction of the teeth of the internal gear and the external gear. A normal line passing through the center of the rotating shaft and parallel to the rotating surface of the external gear with respect to the line connecting the center of the rotating shaft and the center of the internal gear It is characterized in that.

[0015] By adopting such a configuration, it is possible to provide a simple reclining device by omitting a cam while achieving the above-described effects.

Brief Description of the Drawings

[0016]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Embodiments for Carrying Out the Invention

[0017] Hereinafter, the reclining device 100 according to the embodiments of the present invention will be described in detail 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 of FIG. 2. It should be noted that the embodiments and drawings described below are examples of a part of the embodiments of the present invention and are not used for the purpose of limiting them to these configurations. In addition, the same or similar reference numerals are assigned to corresponding components in each figure.

[0018] (First Embodiment) As shown in FIG. 1, the reclining device 100 according to the first embodiment is a device that is attached to the center position of the tilt of the seat back 220 that is tiltably attached to the seat cushion 210 of the vehicle seat 200 and gives the seat back 220 a tilting function. Specifically, it is directly or indirectly attached and used via another mounting plate 230 (hereinafter referred to as "mounting plate etc.") between the seat cushion frame disposed inside the seat cushion 210 and the seat back frame disposed inside the seat back 220.

[0019] As mainly shown in FIGS. 2 and 3, the reclining device 100 according to the present invention includes an external gear 10, an internal gear 20, a rotating shaft 30, a bush 40, 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. In FIG. 2, the spring cover 70 and the plate cover 80 are omitted for easy viewing of the internal structure.

[0020] As shown in FIG. 3, the external gear 10 is formed in a disc shape, external teeth 11 are formed on the outer peripheral surface 10a, and a cylindrical boss 12 is formed at the center. The external gear 10 is provided with a protrusion 13 on the outer surface and is attached by welding or the like in a state of being fitted into a fitting hole provided in the mounting plate etc. 230.

[0021] The internal gear 20 is formed in a disk shape having a diameter larger than that of the external gear 10, and a cylindrical recess is formed so that the external gear 10 can be mounted inside. Internal teeth 21 are formed on the inner peripheral surface 20a of this recess. The internal teeth 21 are formed with at least one or more teeth more than the number of teeth of the external teeth 11 of the external gear 10. As shown in FIG. 2, the external gear 10 and the internal gear 20 are engaged with the internal teeth 21 and the external teeth 11 such that the centers C1 of the external gear 10 and C2 of the internal gear 20 are eccentric. Therefore, the external gear 10 and the internal gear 20 form a differential gear. When the internal gear 20 makes one revolution around the external teeth 11, the rotation advances by the difference in the number of teeth between the internal teeth 21 and the external teeth 11. That is, for example, when there is a difference of only one tooth, when the external gear 10 makes one revolution around the internal gear 20, it rotates by one tooth. A through hole 22 is provided at the center of the internal gear 20. As shown in FIG. 3, a protrusion 23 is also provided on the outer surface of the internal gear 20, and it is attached by welding or the like in a state of being fitted into a fitting hole provided in a mounting plate or the like 230.

[0022] The rotating shaft 30 is coaxially and rotatably inserted into the cylindrical boss 12 of the external gear 10. Further, the rotating shaft 30 is rotationally driven when adjusting the tilt of the seat back 220, and serrations 31 are provided on the inner cylindrical surface to receive the rotational force of the tilting motor. Furthermore, the rotating shaft 30 has a fitting recess 32 that fits with a protrusion 42 provided on a bush 40 described later. The fitting recess 32 is attached so as to sandwich the protrusion 42 from both sides. No matter whether the rotating shaft 30 is rotated clockwise or counterclockwise, the bush 40 rotates in the same manner as the rotating shaft 30.

[0023] The bush 40 is an annular or ring-shaped member disposed between the outer peripheral surface 12a of the cylindrical boss 12 of the external gear 10 and the through hole 22 of the internal gear 20. As shown in FIG. 5, the bush 40 is formed in a ring shape in which the center C3 of the inner peripheral surface 41a of the cylindrical boss hole 41 and the center C4 with respect to the outer peripheral surface 43 are offset and eccentric.

[0024] The bush 40 is provided with a protrusion 42 on its side surface that fits into the fitting recess 32 described above. The number and position of the protrusions 42 are not particularly limited. As a result, the bush 40 will rotate in synchronization with the rotation of the rotating shaft 30.

[0025] Between the outer peripheral surface 43 of the bush 40 and the inner peripheral surface 22a of the through-hole 22 of the internal gear 20, a pair of wedge-shaped cams 50a and 50b (50) are provided so as to contact both. As shown in FIG. 3, the wedge-shaped cam 50a and the wedge-shaped cam 50b are formed symmetrically with respect to a plane. The convex surface 52 (the outer surface) of the wedge-shaped cam 50 has substantially the same curved surface as the curved surface of the inner peripheral surface 22a of the through-hole 22 of the internal gear 20, and is formed such that the wall thickness gradually becomes thinner from the opposite side. On the outer peripheral surface 43 of the bush 40, two cam accommodating portions 44 are formed so that the gap gradually becomes narrower from the opposite side in accordance with the shape of the wedge-shaped cam 50, and the wedge-shaped cam 50 is inserted into this cam accommodating portion 44. The entire cam accommodating portion 44 and the wedge-shaped cams 50a and 50b arranged in this cam accommodating portion 44 are with respect to the meshing direction D of each tooth of the internal gear 20 and the external gear 10, that is, the direction D in which the bush 40 presses against the external gear 10, the center C1 of the rotating shaft 30, that is External gear 10 It is necessary to be arranged on the side opposite to the pressing direction with respect to the normal line V at the center C1. That is, it is necessary to be arranged within the range of the arrow R. By adopting such a configuration, when an external force is applied from the meshing portion to the external gear 10 from the internal gear 20, between the outer peripheral surface 43 of the bush 40 that presses the inner peripheral surface 22a of the through-hole 22 of the internal gear 20 with respect to the applied direction, there is no cam accommodating portion 44, wedge-shaped cam 50a, and wedge-shaped cam 50b arranged, and the entire half circumference of the inner peripheral surface 22a of the through-hole 22 of the internal gear 20 can be completely loaded by the half circumference of the outer peripheral surface 43 of the bush 40. Therefore, it can withstand a high load.

[0026] As shown in Fig. 3, the spring 60 has an annular portion 61 and end portions 62a and 62b that rise from the annular portion 61 at a 90° bend. The end portions 62a and 62b are disposed on the end faces on the thick-walled portion side of the wedge-shaped cams 50a and 50b, and bias the respective wedge-shaped cams 50a and 50b in a direction in which they are separated from each other. Thereby, the external gear 10 can be pressed against and engaged with the internal gear 20. Note that the spring 60 may be another elastic body such as rubber as long as it can bias the wedge-shaped cams 50a and 50b.

[0027] As shown in Fig. 4, the spring cover 70 is a cover for holding the spring 60 so that the spring 60 does not come off, and is not particularly limited as long as it can hold the spring 60.

[0028] The plate cover 80 is formed of a metal plate formed in an annular shape, and is fixed to the end portion on the outer peripheral side of the internal gear 20 by welding or the like, and has a function of restricting the axial movement of the external gear 10.

[0029] The reclining device 100 thus manufactured operates as follows. When no force is applied to the rotating shaft 30 and it is not rotating, the pair of wedge-shaped cams 50a and 50b are biased by the spring 60 in a direction in which they are separated, and are in contact with the bush 40 and the inner peripheral surface 22a of the through hole 22 of the internal gear 20. For this reason, 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.

[0030] From this locked state, if the rotating shaft 30 is rotated counterclockwise, for example, in FIG. 2, the bush 40 engaged with the rotating shaft 30 also rotates accordingly. Further, a wedge angle is set on the inner wall of the cam receiving portion 44 of the bush 40, and the inner wall of the wedge angle is in contact with the wedge-shaped cam 50. Due to the rotation of the bush 40, a gap is generated between the inner wall of the wedge angle and the wedge-shaped cam 50, and the wedge comes off. The rotating shaft 30 and the bush 40 rotate counterclockwise with respect to the external gear 10. As a result, a gap is generated between the cylindrical boss 12 of the bush 40 and the external gear 10 and between the through hole 22 of the bush 40 and the internal gear 20, and the external gear 10 becomes rotatable with respect to the internal gear 20. Along with this, the wedge-shaped cam 50a rotates counterclockwise so as to fill this gap by the biasing force of the spring 60. The wedge-shaped cam 50 rotates counterclockwise so as to slide together with the rotating shaft 30 and the bush 40. In this way, the external gear 10, the internal gear 20, and the rotating shaft 30 constitute a differential gear mechanism. Note that rotation in the clockwise direction can also be performed in the same manner.

[0031] In the reclining device 100 thus manufactured, since the bush 40 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 tries to move in the direction of the external force or the reaction force. However, with respect to the direction in which it tries to move, the bush is sandwiched vertically between the outer peripheral surface 12a of the cylindrical boss 12 of the external gear 10 and the through hole 22 of the internal gear 20, and the component force can be suppressed to a minimum to serve as a bearing. Therefore, sliding is stabilized and smooth rotation can be ensured.

[0032] (Second Embodiment) The reclining device 100 according to the second embodiment is shown in FIGS. 6 and 7. Since the reclining device 100 according to the second embodiment is the same as that of the first embodiment except for the bush 40, these descriptions are omitted.

[0033] The bush 40 according to the second embodiment has a cam accommodation portion 44 formed between the inner peripheral surface 41a of the hole 41 for the cylindrical boss of the bush 40 and the through hole 22 of the internal gear 20 such that the gap gradually narrows from the facing side, and the wedge-shaped cam 50 is inserted into this cam accommodation portion 44. That is, in the first embodiment, the cam accommodation portion 44 is formed on the outer peripheral side of the bush 40, whereas in the second embodiment, the cam accommodation portion 44 is formed on the inner peripheral side of the bush 40, which is different. Also, the entire cam accommodation portion 44 and the wedge-shaped cams 50a and 50b arranged in this cam accommodation portion 44 are in the meshing direction D of the teeth of the internal gear 20 and the external gear 10, that is, the direction D in which the bush 40 presses against the external gear 10, relative to the normal line V at the center C1 of the rotation shaft 30, that is External gear 10 it is necessary to be arranged on the side opposite to the pressing direction with respect to the normal line V at the center C1. That is, it is necessary to be arranged within the range of the arrow R. By adopting such a configuration, when an external force is applied to the meshing portion from the internal gear 20 to the external gear 10, the cam accommodation portion 44, the wedge-shaped cams 50a and 50b are not arranged between the outer peripheral surface 43 of the bush 40 that presses against the inner peripheral surface 22a of the through hole 22 of the internal gear 20 in the applied direction, and the entire half circumference of the inner peripheral surface 22a of the through hole 22 of the internal gear 20 where the force is applied can be completely loaded by the entire half circumference of the outer peripheral surface 43 of the bush 40. Therefore, it can withstand high-strength loads.

[0034] In the reclining device 100 according to this second embodiment, when no force is applied to the rotation shaft 30 and it is not rotating, the pair of wedge-shaped cams 50a and 50b are biased by the spring 60 in the direction in which they separate and are in contact with the bush 40 and the outer peripheral surface 12a of the cylindrical boss 12 of the external gear 10. For this reason, 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.

[0035] From this locked state, when the rotating shaft 30 is rotated counterclockwise, the bush 40 engaged with the rotating shaft 30 also rotates accordingly. Further, a wedge angle is set on the inner wall of the cam accommodating portion 44 of the bush 40, and the inner wall of the wedge angle is in contact with the wedge-shaped cam 50. Due to this rotation, a gap is generated between the inner wall of the wedge angle and the wedge-shaped cam 50, and the wedge comes off. The rotating shaft 30 and the bush 40 rotate counterclockwise with respect to the internal gear 20. As a result, a gap is generated between the cylindrical boss 12 of the external gear 10 and the bush 40 and between the through hole 22 of the internal gear 20 and the bush 40, and the external gear 10 becomes rotatable with respect to the internal gear 20. Along with this, the wedge-shaped cam 50a rotates counterclockwise so as to fill this gap by the biasing force of the spring 60. The wedge-shaped cam 50 rotates counterclockwise so as to slide together with the rotating shaft 30 and the bush 40. Thus, the external gear 10, the internal gear 20, and the rotating shaft 30 constitute a differential gear mechanism. Note that rotation in the clockwise direction can also be performed in the same manner.

[0036] In the reclining device 100 thus manufactured, since the bush 40 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 tries to move in the direction of the external force or the reaction force. However, with respect to the direction in which it tries to move, the bush 40 is sandwiched vertically between the outer peripheral surface 12a of the cylindrical boss 12 of the external gear 10 and the inner peripheral surface 22a of the through hole 22 of the internal gear 20, and the component force can be suppressed to a minimum and it can serve as a bearing. Therefore, sliding is stabilized and smooth rotation can be ensured.

[0037] (Third Embodiment) The reclining device 100 according to the third embodiment is shown in FIG. 8. The reclining device 100 according to the third embodiment does not have the wedge-shaped cam 50, and on the outer peripheral surface of the bush 40, instead of the cam housing portion 44, a spring housing portion 44a is formed. Since it is substantially the same as the first embodiment except that the end portions 62a and 62b are arranged in the spring housing portion 44a so as to be biased in a direction away from each other, descriptions other than the bush 40 and the spring 60 are omitted.

[0038] Between the outer peripheral surface 43 of the bush 40 and the inner peripheral surface 22a of the through hole 22 of the internal gear 20, spring housing portions 44a are provided on both sides sandwiching the annular thickest part (the thickest part) of the bush 40. The spring housing portions 44a are formed symmetrically with respect to the surface and are formed to gradually become narrower from the opposite sides.

[0039] The spring 60 has, as in the first embodiment, an annular portion 61 and end portions 62a and 62b that rise up so as to bend 90° from this annular portion 61. These end portions 62a and 62b are arranged in the spring housing portion 44a, and the end portions 62a and 62b are biased in a direction away from each other. As a result, the spring 60 itself presses the external gear 10 against the internal gear 20 to mesh them.

[0040] Note that the entire spring housing portion 44a and the end portions 62a and 62b of the spring 60 arranged in this spring housing portion 44a are in the meshing direction D of the teeth of the internal gear 20 and the external gear 10, that is, the direction D in which the bush 40 presses against the external gear 10, with respect to the center C1 of the rotary shaft 30, that is External gear 10It is necessary to be arranged on the side opposite to the pressing direction with respect to the normal line V at the center C1. That is, it is necessary to be arranged within the range of the arrow R. By adopting such a configuration, when an external force is applied from the meshing portion to the external gear 10 from the internal gear 20, a spring accommodation portion 44a, end portions 62a, 62b of the spring 60 are not arranged between the outer peripheral surface 43 of the bush 40 that presses against the inner peripheral surface 22a of the through hole 22 of the internal gear 20 with respect to the applied direction, and the entire half circumference of the inner peripheral surface 22a of the through hole 22 of the internal gear 20 can be completely loaded by the half circumference of the outer peripheral surface of the bush 40. Therefore, it can withstand high strength and load.

[0041] The reclining device 100 manufactured in this way operates as follows. When no force is applied to the rotating shaft 30 and it is not rotating, the bush 40 is urged by the spring 60 and is in contact with the inner peripheral surface 22a of the through hole 22 of the internal gear 20. For this reason, 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.

[0042] When the rotating shaft 30 is rotated counterclockwise from this locked state, the bush 40 engaged with the rotating shaft 30 also rotates accordingly. Further, a wedge angle is set on the inner wall of the spring housing portion 44a of the bush 40, and the inner wall of the wedge angle is in contact with the end portions 62a and 62b of the spring 60. Due to the rotation of the bush 40, a gap is generated between the inner wall of the wedge angle and the end portions 62a and 62b of the spring 60, and the end portions 62a and 62b of the spring 60 are disengaged. By this rotation, a force is applied in the direction of pulling out the end portion 62a of the spring 60 from the gap by the side wall of the spring housing portion 44a of the bush 40. The rotating shaft 30 and the bush 40 rotate counterclockwise with respect to the internal gear 20. As a result, a gap is generated between the cylindrical boss 12 of the external gear 10 and the bush 40, and between the through hole 22 of the internal gear 20 and the bush 40, and the external gear 10 becomes rotatable with respect to the internal gear 20. Along with this, it rotates counterclockwise so as to fill the gap by the biasing force of the end portion 62b of the spring 60. Thus, the spring 60 rotates counterclockwise so as to slide together with the rotating shaft 30 and the bush 40. In this way, the external gear 10, the internal gear 20, and the rotating shaft 30 constitute a differential gear mechanism. Note that rotation in the clockwise direction can also be performed in the same manner.

[0043] In the reclining device 100 thus manufactured, since the bush 40 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 tries to move in the direction of the external force or the reaction force. However, with respect to the direction in which it tries to move, the bush 40 is sandwiched vertically between the outer peripheral surface 12a of the cylindrical boss 12 of the external gear 10 and the through hole 22 of the internal gear 20, and the component force can be minimized to serve as a bearing. Therefore, sliding is stabilized and smooth rotation can be ensured.

[0044] (Fourth Embodiment) The reclining device 100 according to the fourth embodiment is shown in FIG. 9. As shown in FIG. 9, in the fourth embodiment, two spring accommodation portions 44b are formed on the inner peripheral surface 41a of the bush 40 such that the gap gradually narrows from the opposite side. The end portions 62a and 62b of the spring 60 are inserted into the spring accommodation portions 44b. That is, in the above-described third embodiment, the spring accommodation portion 44a is formed on the outer peripheral side of the bush 40, whereas in the fourth embodiment according to FIG. 9, the spring accommodation portion 44b is formed on the inner peripheral side of the bush 40. This is substantially the same as the second embodiment, except that there is no wedge-shaped cam 50, the spring accommodation portion 44b is formed on the bush 40, and the end portions 62a and 62b are arranged in the spring accommodation portion 44b so as to bias in the direction of separating from each other.

[0045] Note that the entire spring accommodation portion 44b and the end portions 62a and 62b of the spring 60 arranged in the spring accommodation portion 44b are arranged on the side opposite to the pressing direction D, that is, on the normal line V at the center C1 of the rotation shaft 30, that is, at the center C1 of the external gear 10, with respect to the meshing direction D of the teeth of the internal gear 20 and the external gear 10, that is, the direction in which the bush 40 presses against the external gear 10. That is, it is necessary to be arranged within the range of the arrow R. By adopting such a configuration, when an external force is applied to the meshing portion from the internal gear 20 to the external gear 10, the spring accommodation portion 44a, the end portions 62a and 62b of the spring 60 are not arranged between the outer peripheral surface 43 of the bush 40 that presses against the inner peripheral surface 22a of the through hole 22 of the internal gear 20 in the applied direction, and the entire half circumference of the inner peripheral surface 22a of the through hole 22 of the internal gear 20 can be completely loaded by the half circumference of the outer peripheral surface of the bush 40. Therefore, it can withstand high strength and load.

[0046] Note that the present invention is not limited to the above-described embodiments, and can be implemented in various forms as long as it belongs to the technical scope of the present invention.

Industrial Applicability

[0047] As shown in the above-described embodiments, it is mainly industrially applicable as a reclining device for a vehicle seat.

Explanation of Reference Numerals

[0048] 10... external gear, 10a... outer peripheral surface, 11... external teeth, 12... cylindrical boss, 12a... outer peripheral surface, 13... protruding portion, 20... internal gear, 20a... inner peripheral surface, 21... internal teeth, 22... through hole, 22a... inner peripheral surface, 23... protruding portion, 30... rotating shaft, 31... serration, 32... fitting recess, 40... bush, 41... hole for cylindrical boss, 41a... inner peripheral surface, 42... protruding portion, 43... outer peripheral surface, 44... cam accommodating portion, 44a... spring accommodating portion, 44b... spring accommodating portion, 50... wedge-shaped cam, 50a... wedge-shaped cam, 50b... wedge-shaped cam, 52... convex surface, 60... spring, 61... annular portion, 62a... end portion, 62b... end portion, 70... spring cover, 80... plate cover, 100... reclining device, 200... vehicle seat, 210... seat cushion, 220... seat back, 230... mounting plate

Claims

1. A reclining device for a seat that tiltably holds a seat back frame constituting a seat back with respect to a seat cushion frame constituting 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 cylindrical boss coaxial with an axial direction formed 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, has internal teeth that can mesh with the external teeth provided at least one or more more than the external teeth, and has a through hole coaxial with the axial direction formed therein; a rotating shaft that is coaxially and rotatably inserted into the cylindrical boss of the external gear and rotates one of the external gear or the internal gear about the other gear shaft; a bush that is disposed between an inner periphery of the through hole of the internal gear and an outer periphery of the cylindrical boss of the external gear, is formed in an annular shape with an eccentricity between a center of an outer peripheral surface and a center of an inner peripheral surface, has a cam accommodation portion on an outer peripheral side, and rotates with rotation of the rotating shaft; a pair of wedge-shaped cams that are accommodated in the cam accommodation portion, press the through hole of the internal gear and the bush to bring the bush into contact with an outer peripheral surface of the cylindrical boss of the external gear, thereby restricting relative rotation between the external gear and the internal gear, and by rotating the rotating shaft, sliding the outer peripheral surface of the cylindrical boss of the external gear or the inner peripheral surface of the through hole of the internal gear of the bush and the bush to allow relative rotation between the external gear and the internal gear; and an elastic body that biases the pair of wedge-shaped cams to simultaneously contact the bush and the cylindrical boss, characterized in that the entire cam accommodation portion and the wedge-shaped cams disposed in the cam accommodation portion are disposed on the opposite side of the pressing direction from a normal line passing through the center of the rotating shaft and parallel to a rotation surface of the external gear with respect to a line connecting the center of the rotating shaft and the center of the internal gear with respect to a meshing direction of each tooth of the internal gear and the external gear.

2. A reclining device for a seat that tiltably holds a seat back frame constituting a seat back with respect to a seat cushion frame constituting 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 its outer peripheral surface, and has a cylindrical boss coaxial with the axial direction formed on its 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, has internal teeth that can mesh with the external teeth provided at least one or more more than the external teeth on its inner peripheral surface, and has a through hole coaxial with the axial direction formed therein, A rotating shaft that is coaxially and rotatably inserted into the cylindrical boss of the external gear, and rotates one of the external gear or the internal gear around the gear shaft of the other, A bush 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, is formed in an annular shape with the center of the outer peripheral surface and the center of the inner peripheral surface being eccentric, has a cam accommodating portion on the inner peripheral side, and rotates as the rotating shaft rotates, A pair of wedge-shaped cams that are accommodated in the cam accommodating portion, press the cylindrical boss of the external gear and the bush to bring the bush into contact with the inner peripheral surface of the through hole of the internal gear, thereby restricting relative rotation between the external gear and the internal gear, and by rotating the rotating shaft, sliding the outer peripheral surface of the cylindrical boss of the external gear or the inner peripheral surface of the through hole of the internal gear of the bush and the bush to allow relative rotation between the external gear and the internal gear, An elastic body that biases the pair of wedge-shaped cams to simultaneously contact the bush and the cylindrical boss, A reclining device, characterized in that the entire cam accommodating portion and the wedge-shaped cams disposed in the cam accommodating portion are disposed on the side opposite to the pressing direction with respect to the normal line parallel to the rotation surface of the external gear, passing through the center of the rotating shaft and connecting the center of the rotating shaft and the center of the internal gear with respect to the meshing direction of the teeth of the internal gear and the external gear.

3. A reclining device for a seat that tiltably holds a seat back frame constituting a seat back with respect to a seat cushion frame constituting 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 its outer peripheral surface, and has a cylindrical boss coaxial with the axial direction formed on its 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, has internal teeth that can mesh with the external teeth provided on the inner peripheral surface with at least one or more more than the external teeth, and has a through hole coaxial with the axial direction formed therein. A rotating shaft that is coaxially and rotatably inserted into the cylindrical boss of the external gear, and rotates either the external gear or the internal gear about the gear shaft of the other. An annular member 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, is formed with an eccentric center between the center of the outer peripheral surface and the center of the inner peripheral surface, has a spring accommodating portion on the outer peripheral side, and rotates with the rotation of the rotating shaft. A pair of end portions that are accommodated in the spring accommodating portion, press the through hole of the internal gear and the bush to bring the bush into contact with the outer peripheral surface of the cylindrical boss of the external gear, thereby restricting relative rotation between the external gear and the internal gear, and by rotating the rotating shaft, slide the outer peripheral surface of the cylindrical boss of the external gear and the bush or the inner peripheral surface of the through hole of the internal gear and the bush to allow relative rotation between the external gear and the internal gear, and the end portions are provided with an elastic body that biases in a direction of contacting the bush and the cylindrical boss simultaneously. A reclining device, characterized in that the entire spring accommodating portion and the pair of end portions disposed in the spring accommodating portion are disposed on the side opposite to the pressing direction with respect to the normal line parallel to the rotation surface of the external gear and passing through the center of the rotating shaft with respect to the line connecting the center of the rotating shaft and the center of the internal gear with respect to the meshing direction of the teeth of the internal gear and the external gear.

4. A reclining device for a seat that tiltably holds a seat back frame constituting a seat back with respect to a seat cushion frame constituting 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 the outer peripheral surface, and has a cylindrical boss coaxial with the axial direction formed on the inner peripheral surface. It is directly or indirectly attached to the other of the seat cushion frame and the seat back frame, has internal teeth that can mesh with the external teeth provided on the inner peripheral surface with at least one or more more than the external teeth, and an internal gear with a through-hole coaxial with the axial direction; A rotating shaft that is coaxially and rotatably inserted into the cylindrical boss of the external gear, and rotates either the external gear or the internal gear about the gear shaft of the other; It 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, is formed in an annular shape with the center of the outer peripheral surface and the center of the inner peripheral surface being eccentric, has a spring accommodation portion on the inner peripheral side, and a bush that rotates with the rotation of the rotating shaft; It is accommodated in the spring accommodation portion, presses the cylindrical boss of the external gear and the bush to bring the bush into contact with the inner peripheral surface of the through-hole of the internal gear, thereby restricting the relative rotation between the external gear and the internal gear, and by rotating the rotating shaft, the outer peripheral surface of the cylindrical boss of the external gear and the bush or the inner peripheral surface of the through-hole of the internal gear and the bush are slid to allow the relative rotation between the external gear and the internal gear. It has a pair of end portions, and the end portions are provided with an elastic body that biases towards contacting the bush and the cylindrical boss simultaneously; The reclining device is characterized in that the entire spring accommodation portion and the pair of end portions disposed in the spring accommodation portion are arranged on the side opposite to the pressing direction with respect to the normal line parallel to the rotation surface of the external gear, passing through the center of the rotating shaft with respect to the line connecting the center of the rotating shaft and the center of the internal gear with respect to the meshing direction of the teeth of the internal gear and the external gear.

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