Seat reclining device

Abstract

To provide a seat reclining device which widely secures an adjustable range allowing engagement of a pole to a ratchet of the seat reclining device and a free zone to block engagement.SOLUTION: A seat reclining device 4 comprises: a ratchet 10 and a guide 20 which are rotatably connected with each other; and a first pole 30A and a second pole 30B which are supported by the guide 20 and lock rotation thereof through engagement with the ratchet 10. The ratchet 10 includes a first regulation guide 12A and a second regulation guide 12B which prevent engagement of the first pole 30A and the second pole 30B in a free zone through contacting a first projection 34A of the first pole and a second projection 34B of the second pole with an inner peripheral surface. The first projection 34A can pass through, when the ratchet 10 enters from the free zone to an adjustable range, from an outer area in a radial direction to a rotation direction since the second regulation guide 12B has an inner peripheral surface and an outer peripheral surface at the inner position in the radial direction relative to the inner peripheral surface of the first regulation guide 12A.SELECTED DRAWING: Figure 15

Description

[Technical field]

[0001] The present invention relates to a seat reclining device, and more particularly to a seat reclining device equipped with a lock mechanism that allows the backrest angle of a seat back to be adjusted. [Background technology]

[0002] Patent Document 1 discloses a seat reclining device for adjusting the angle of the seat back. This seat reclining device includes a ratchet and a guide that are assembled so as to be rotatable about a central axis of the reclining mechanism. The ratchet is connected to the seat back. The guide is connected to the seat cushion.

[0003] Three poles are provided between the ratchet and the guide to lock the relative rotation between them. Each pole is supported by the guide on both sides in the direction of rotation, and is pushed outward in the radial direction to mesh with the ratchet and lock the relative rotation of the ratchet.

[0004] Each pawl is formed with a protrusion that is pushed outward in the radial direction when the ratchet is in a predetermined rotational region (free zone) and comes into contact with the inner peripheral surface of a regulating guide formed on the ratchet. When the protrusions come into contact with the regulating guide of the ratchet, each pawl is prevented from engaging with the ratchet.

[0005] The regulating guide is adapted to bring the projections of the poles into contact with each other at different radial positions when the ratchet is in the free zone. As a result, when the ratchet is out of the free zone and in an adjustment range that allows meshing, the regulating guide is adapted to release interference so that it does not come into contact with any projections. On the other hand, when the ratchet is in the free zone, the regulating guide is adapted to bring the projections of the poles into contact with each other all at once. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Patent No. 5592753 Summary of the Invention [Problem to be solved by the invention]

[0007] The restricting guide is configured to have a recess formed in a part that is recessed from the inside in the radial direction in order to avoid interference with the protrusion of the pole that should not come into contact when the ratchet is in the adjustment range. In addition, the protrusion of the specific pole is shorter than the other protrusions so that it can pass through the recess.

[0008] Therefore, the regulating guide has a configuration in which the portion where the protrusion contacts and the portion where the protrusion escapes (recess) are aligned in the axial direction, increasing the thickness. Also, because the protrusion of a specific pole is short, the contact area with the regulating guide is reduced, and the strength to prevent meshing is reduced. Therefore, the present invention provides a seat reclining device that can appropriately and widely secure the adjustment range that allows the pole to mesh with the ratchet and the free zone that prevents meshing. [Means for solving the problem]

[0009] As a means for solving the above problems, the seat reclining device of the present invention employs the following means.

[0010] That is, a first aspect of the present invention is a seat reclining device comprising: a ratchet and a guide connected to each other so as to be rotatable about a central axis of reclining; and a plurality of pawls supported by the guide from both sides in the direction of rotation and meshing with the ratchet by being pushed outward in the radial direction to lock the rotation, wherein the ratchet has a regulating guide that prevents the plurality of pawls from meshing with each other by being pushed outward in a free zone, which is a predetermined rotation region, by abutting against its inner circumferential surface, and the plurality of pawls include a first pawl and a second pawl that are aligned in the direction of rotation, and the regulating guide has a regulating guide that prevents the plurality of pawls from meshing with each other by being pushed outward in the radial direction, and the inner circumferential surface of the regulating guide is curved at different radii of curvature around the central axis. The seat reclining device has a first restricting guide and a second restricting guide that are lined up and divided in the rotational direction so as to curve, wherein the first restricting guide prevents engagement of the first pole by abutting a first protrusion protruding axially from the first pole against its inner circumferential surface, and the second restricting guide prevents engagement of the second pole by abutting a second protrusion protruding axially from the second pole against its inner circumferential surface, and the inner and outer circumferential surfaces are located radially inward relative to the inner circumferential surface of the first restricting guide, so that when the ratchet leaves the free zone and enters an adjustment range that allows engagement, the first protrusion passes in the rotational direction from its radially outer region.

[0011] According to the first invention, when the ratchet is in the free zone, the first protrusion of the first pole and the second protrusion of the second pole can be brought into contact with the first and second regulating guides, respectively, to prevent engagement. Also, when the ratchet is in the adjustment range, the first protrusion of the first pole can be passed outside the second regulating guide, allowing the first protrusion to be engaged with the second regulating guide even if the arrangement of the first protrusion overlaps with that of the second regulating guide in the rotational direction. As a result, even if multiple poles are provided, a wide adjustment range and free zone can be set for the ratchet.

[0012] A second invention of the present invention is a seat reclining device according to the first invention, wherein the multiple poles further include a third pole aligned in the rotational direction with the first pole and the second pole, the regulating guide further includes a third regulating guide aligned in the rotational direction with the first regulating guide and the second regulating guide and having an inner circumferential surface curved around the central axis, the third regulating guide has its inner circumferential surface located radially inward from the inner circumferential surface of the first regulating guide and radially outward from the inner circumferential surface of the second regulating guide, and a third protrusion protruding axially from the third pole is abutted against the inner circumferential surface to prevent engagement of the third pole.

[0013] According to the second invention, even in a configuration in which three poles are lined up in the rotational direction, each pole can be brought into contact with a regulating guide in the free zone to prevent meshing, and a wide adjustment range and free zone can be set for the ratchet.

[0014] A third invention of the present invention is a seat reclining device according to the second invention, wherein the ratchet has a disc portion which expands radially in a disc shape and is formed so that the regulating guide protrudes axially, and a cylindrical portion which protrudes axially from an outer circumferential edge of the disc portion along the outer circumferential edge and has internal teeth along its inner circumferential surface for engaging with the plurality of pawls, wherein the first regulating guide and the third regulating guide protrude axially from the outer circumferential edge of the disc portion which is radially inward from the cylindrical portion, and the second regulating guide protrudes axially from the disc portion at a position radially inward from the first regulating guide and the third regulating guide so as to be like a floating island separated from the first regulating guide and the third regulating guide.

[0015] According to the third aspect of the present invention, the first, second and third restriction guides can be simply and appropriately formed by half-punching the ratchet. Even if the second restriction guide is formed on the ratchet, the internal teeth can be appropriately formed at the radially outer position of the second restriction guide. [Brief description of the drawings]

[0016] [Figure 1] 1 is a perspective view of a seat to which a seat reclining device according to a first embodiment is applied. [Diagram 2] FIG. [Diagram 3] FIG. 3 is a perspective view of FIG. 2 as seen from the opposite side. [Figure 4] FIG. [Diagram 5] FIG. 5 is an exploded perspective view of FIG. 4 as viewed from the opposite side. [Figure 6] FIG. 13 is a perspective view of the poles and cams assembled to the guide. [Figure 7] FIG. 2 is an inner side view of the seat reclining device. [Figure 8] FIG. 8 is a cross-sectional view taken along line VIII-VIII in FIG. [Figure 9] 9 is a cross-sectional view taken along line IX-IX in FIG. 7. [Figure 10] FIG. 8 is a partial cross-sectional view of the ratchet shown in FIG. 7 with a disc portion cut away. [Figure 11] 5 is a schematic diagram showing a locked state of the seat reclining device. FIG. [Figure 12] FIG. 4 is a schematic diagram showing a seat reclining device in a released state. [Figure 13] 13 is a schematic diagram showing a state in which the ratchet is rotated within an adjustment range. FIG. [Figure 14] FIG. 13 is a schematic diagram showing the maximum position of the ratchet adjustment range. [Figure 15] FIG. 13 is a schematic diagram showing the state in which the ratchet is rotated into the free zone. [Figure 16] FIG. 13 is a schematic diagram showing the maximum position of the ratchet free zone. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0018] (First embodiment) <<Overall configuration of seat reclining device 4>> First, the configuration of a seat reclining device (hereinafter, referred to as a recliner) 4 according to a first embodiment of the present invention will be described with reference to Figures 1 to 16. In the following description, when directions such as front, back, up, down, left and right are indicated, they refer to the respective directions shown in each drawing. In the following description, when no specific reference drawing is indicated or when no reference drawing has a corresponding reference symbol, any of Figures 1 to 16 will be referred to as appropriate.

[0019] As shown in Fig. 1, the recliner 4 according to this embodiment is applied to a seat 1 which constitutes the right-side seat of an automobile. The seat 1 has a seat back 2 which constitutes the backrest for a seated occupant, and a seat cushion 3 which constitutes the seating portion. The recliner 4 is configured as a reclining adjuster which connects the seat back 2 to the seat cushion 3 so that the backrest angle can be adjusted.

[0020] Specifically, the recliners 4 are assembled so as to be interposed between the lower ends of the side frames 2F of the seat back 2 and the reclining plates 3F connected to the rear ends of the left and right side frameworks of the seat cushion 3. As a result, each recliner 4 connects each side frame 2F of the seat back 2 to each reclining plate 3F so as to be rotatable about a central axis C extending in the seat width direction and coaxial with each other.

[0021] Each recliner 4 is normally held in a locked state that fixes the backrest angle of the seatback 2. When the user pulls up the reclining lever 5 provided on the side of the seat cushion 3 on the outer side of the vehicle (right side), the recliners 4 are simultaneously released from their locked state. This switches each recliner 4 to a state in which the backrest angle of the seatback 2 can be adjusted in the front-rear direction of the seat.

[0022] When the reclining lever 5 is released, each recliner 4 is biased to move in the direction of returning to the locked state. However, each recliner 4 has a free zone set therein where the recliner will not return to the locked state even if the reclining lever 5 is released, depending on the angle of the seat back 2.

[0023] Specifically, this free zone is set to a rotational range in which the seat back 2 is tilted forward from a substantially upright position. By setting this free zone, even if the reclining lever 5 is released when the seat back 2 is tilted forward from a substantially upright position, the seat back 2 is not locked in that position and can be tilted forward to the maximum position.

[0024] The rotation range in which the seat back 2 is tilted backward from a substantially upright position is set as an adjustment range in which each recliner 4 is returned to a locked state by releasing the operation of the reclining lever 5. Therefore, within this adjustment range, the backrest angle of the seat back 2 can be adjusted by operating the reclining lever 5.

[0025] Return springs 6 that apply a forward rotational force to the seat back 2 are hooked between each side frame 2F of the seat back 2 and each reclining plate 3F located on the outside of the side frames 2F. The biasing force of these return springs 6 causes the seat back 2 to be raised up to a position where it will come into contact with the back of a seated occupant when the locked state of each recliner 4 is released.

[0026] The seat back 2 has a backrest angle adjusted forward and backward to follow the movement of the seated occupant as the back of the occupant tilts forward and backward. By setting the return spring 6 in this way, the backrest angle of the seat back 2 can be easily adjusted.

[0027] 2 and 3, each recliner 4 specifically has a disk-shaped ratchet 10 coupled to the outer surface of each side frame 2F (see FIG. 1), and a disk-shaped guide 20 coupled to the inner surface of each reclining plate 3F (see FIG. 1). Each recliner 4 is configured to fix or release the backrest angle of the seat back 2 (see FIG. 1) by switching between locking and releasing the rotation of the ratchet 10 relative to the guide 20 inside the recliner 4.

[0028] 《Configuration of each part》 The detailed configuration of each recliner 4 will be described below. Note that each recliner 4 has a configuration symmetrical to the other recliners 4. Therefore, the following will describe in detail the configuration of the recliner 4 disposed on the outer side (right side) of the vehicle as shown in Figures 2 and 3 as a representative example.

[0029] 4 and 5, recliner 4 has a disk-shaped ratchet 10 and a guide 20 that are axially assembled so that they can rotate relative to each other around a central reclining axis C. Recliner 4 also has three poles 30 assembled between ratchet 10 and guide 20, and a rotating cam 40 that moves these radially inward and outward.

[0030] The recliner 4 also has a lock spring 50 consisting of a spiral spring that biases the rotating cam 40 in the rotational direction of the locking operation relative to the guide 20. The recliner 4 also has a ring-shaped outer periphery ring 60 that is mounted across the outer periphery of the ratchet 10 and the guide 20. The outer periphery ring 60 is a functional part that maintains the ratchet 10 and the guide 20 in an axially assembled state. Next, the specific configuration of each part will be described.

[0031] Ratchet 10 Ratchet 10 is made of a single metal plate member cut into a substantially circular disk shape. Ratchet 10 has a circular disk portion 11 that spreads out in a circular disk shape in the radial direction. Ratchet 10 also has a regulating guide 12 that is half-punched from the outer periphery of circular disk portion 11 so as to protrude cylindrically inward in the axial direction (the side facing guide 20). Ratchet 10 also has a cylindrical portion 13 that is half-punched from the outer periphery of regulating guide 12 so as to protrude further inward in the axial direction.

[0032] 5, internal teeth 13A are formed continuously arranged over the entire area in the rotational direction on the inner peripheral surface of the cylindrical portion 13. The internal teeth 13A of the cylindrical portion 13 are used as a tooth surface for meshing with external teeth 31 formed on the outer peripheral surface of each pole 30, which will be described later, from the radially inner side.

[0033] The regulating guide 12 is composed of three regions, a first regulating guide 12A, a second regulating guide 12B, and a third regulating guide 12C. The first regulating guide 12A and the third regulating guide 12C are shaped to protrude in an arc shape so as to be continuously aligned with each other in the rotational direction from the outer periphery of the disc part 11. The second regulating guide 12B is shaped to protrude like a floating island from a position spaced radially inward from a peripheral portion 12D protruding from the outer periphery of the disc part 11 so as to be continuously aligned with the first regulating guide 12A and the third regulating guide 12C in the rotational direction.

[0034] The second restriction guide 12B is arranged to be aligned with the first restriction guide 12A and the third restriction guide 12C in the rotational direction, but is shaped to protrude like a floating island separated from them. The first restriction guide 12A, the second restriction guide 12B, and the third restriction guide 12C have inner circumferential surfaces curved around the central axis C with different radii of curvature.

[0035] Specifically, the radius of curvature of each inner peripheral surface increases in the order of the inner peripheral surface of the second restriction guide 12B, the inner peripheral surface of the third restriction guide 12C, and the inner peripheral surface of the first restriction guide 12A. The outer peripheral surface of the second restriction guide 12B is also formed into an arc shape curved around the central axis C.

[0036] The radius of curvature of the outer peripheral surface of the second restriction guide 12B is smaller than the radius of curvature of the inner peripheral surface of the first restriction guide 12A. More specifically, as described later in FIG. 15, the outer peripheral surface of the second restriction guide 12B is configured to have a radial gap T between the inner peripheral surface of the first restriction guide 12A and the outer peripheral surface of the second restriction guide 12B, through which the first protrusion 34A protruding outward in the axial direction from the first pole 30A can pass in the rotational direction.

[0037] The inner peripheral surface of peripheral portion 12D on the radially outer side of second restriction guide 12B is also formed into an arc shape curved around central axis C. The radius of curvature of the inner peripheral surface of peripheral portion 12D is greater than the radius of curvature of the inner peripheral surface of first restriction guide 12A. As will be described later in FIG. 11, when recliner 4 is within the adjustment range, peripheral portion 12D does not come into contact with first protrusion 34A, and functions to allow meshing of first pawl 30A even if first pawl 30A moves to mesh with ratchet 10.

[0038] 15, when the recliner 4 is in the free zone, the regulating guide 12 functions as an engagement preventing portion that prevents engagement of each pawl 30 with the ratchet 10 by abutting against a protrusion 34 protruding from each pawl 30. Specifically, when the recliner 4 is in the free zone, the first regulating guide 12A is disposed in a position that overlaps in the rotational direction with a first protrusion 34A protruding from the first pawl 30A. As a result, the first regulating guide 12A prevents engagement of the first pawl 30A with the ratchet 10 by abutting the first protrusion 34A against its inner peripheral surface.

[0039] Furthermore, the second restricting guide 12B is disposed in a position where it overlaps with the second protrusion 34B protruding from the second pawl 30B in the rotational direction when the recliner 4 is in the free zone. As a result, the second restricting guide 12B prevents the second pawl 30B from engaging with the ratchet 10 by bringing the second protrusion 34B into contact with its inner peripheral surface.

[0040] Furthermore, the third restriction guide 12C is disposed in a position where it overlaps in the rotational direction with the third protrusion 34C protruding from the third pawl 30C when the recliner 4 is in the free zone. As a result, the third restriction guide 12C prevents the third pawl 30C from engaging with the ratchet 10 by bringing the third protrusion 34C into contact with its inner peripheral surface.

[0041] 11, when the recliner 4 is within the adjustment range, the first restricting guide 12A is disposed in a position where it overlaps with the third protrusion 34C protruding from the third pawl 30C in the rotational direction. In this case, even if the third pawl 30C moves to mesh with the ratchet 10, the first restricting guide 12A does not come into contact with the third protrusion 34C, and functions to allow the meshing of the third pawl 30C. This is because the radius of curvature of the inner peripheral surface of the first restricting guide 12A is larger than that of the third restricting guide 12C.

[0042] Furthermore, when the recliner 4 is within the adjustment range, the second restricting guide 12B is disposed in a position where it overlaps in the rotational direction with the first protrusion 34A protruding from the first pawl 30A. However, in this case, even if the first pawl 30A moves to mesh with the ratchet 10, the second restricting guide 12B does not come into contact with the first protrusion 34A, and functions to allow the meshing of the first pawl 30A. This is because the second restricting guide 12B is located radially inward of the first protrusion 34A when the first pawl 30A is in the released state.

[0043] Furthermore, when the recliner 4 is within the adjustment range, the third restricting guide 12C is disposed in a position where it overlaps with the second protrusion 34B protruding from the second pawl 30B in the rotational direction. In this case, even if the second pawl 30B moves to mesh with the ratchet 10, the third restricting guide 12C does not come into contact with the second protrusion 34B, and functions to allow the meshing of the second pawl 30B. This is because the radius of curvature of the inner peripheral surface of the third restricting guide 12C is larger than that of the second restricting guide 12B.

[0044] 4 and 5, a through hole 11A that passes through in a circular shape in the axial direction is formed in the center (the central position through which the central axis C passes) of the disc portion 11. An operation pin 5A that is inserted into the center of a rotating cam 40 (described later) is inserted into this through hole 11A so as to be rotatable in the axial direction.

[0045] Guide 20 The guide 20 is made of a single metal plate member cut into a roughly disk shape that is slightly larger than the ratchet 10. The guide 20 has a disk portion 21 that spreads out in a disk shape in the radial direction. The guide 20 also has a cylindrical portion 22 that is half-punched from the outer periphery of the disk portion 21 so as to protrude cylindrically toward the inside in the axial direction (the side facing the ratchet 10).

[0046] The inner diameter of the cylindrical portion 22 is slightly larger than the outer diameter of the cylindrical portion 13 of the ratchet 10. The guide 20 is set in the cylindrical portion 22 so that the cylindrical portion 13 of the ratchet 10 is loosely fitted into the cylindrical portion 22 in the axial direction.

[0047] As a result, the guide 20 and the ratchet 10 are assembled in a state in which they are supported internally and externally so as to be rotatable relative to each other. After this assembly, an outer peripheral ring 60 (described later) is attached between the cylindrical portion 22 of the guide 20 and the cylindrical portion 13 of the ratchet 10 so as to straddle them from the outer periphery. As a result, the guide 20 and the ratchet 10 are held in a state in which they are prevented from coming off each other in the axial direction via the outer peripheral ring 60 (see Figs. 2 to 3 and 8).

[0048] As shown in Fig. 4, the guide 20 has guide walls 23 that are half-punched so as to protrude inward in the axial direction in a substantially sector shape at three positions in the rotational direction of the disc portion 21. These guide walls 23 are formed in a shape that is three-fold symmetrical with respect to each other in the rotational direction. The outer circumferential surfaces of the guide walls 23 are curved with the same radius of curvature around the central axis C.

[0049] Each guide wall 23 is assembled so that it fits into the cylindrical portion 13 of the ratchet 10 with a small radial gap therebetween by fitting the cylindrical portion 13 of the ratchet 10 into the cylindrical portion 22 of the guide 20 .

[0050] 6, the guide 20 is configured such that guide walls 23 are formed at three positions in the rotation direction of the disk portion 21, thereby forming concave pole accommodating grooves 24 capable of accommodating three poles 30 one by one between the guide walls 23. The guide 20 is also configured such that a concave cam accommodating groove 25 capable of rotatably accommodating a rotating cam 40 is formed in the central portion of the disk portion 21 surrounded by the three guide walls 23.

[0051] Each guide wall 23 is shaped such that each side surface facing the rotation direction forms a guide surface parallel to each side surface in the rotation direction of each pole 30 accommodated in each pole accommodating groove 24. As a result, each guide wall 23 supports each of the three poles 30 accommodated in each pole accommodating groove 24 from both sides in the rotation direction so that each of the poles 30 can slide only inward and outward in the radial direction.

[0052] 4, in the central portion of the disk portion 21 where the cam receiving groove 25 of the guide 20 is formed, a spring receiving groove 26 is formed by half-punching so as to protrude outward in the axial direction. The spring receiving groove 26 is formed in a concave shape capable of receiving a lock spring 50, which will be described later, from the inside in the axial direction. Specifically, the spring receiving groove 26 is composed of a portion recessed into a cylindrical container shape from a part of the central portion where the cam receiving groove 25 of the disk portion 21 is formed, and a portion recessed so as to extend from three peripheral portions in the rotational direction to each region of the disk portion 21 where each pole receiving groove 24 is formed.

[0053] The spring accommodating groove 26 accommodates the lock spring 50 from the inside in the axial direction in its central portion recessed into a cylindrical container shape. The spring accommodating groove 26 has three recessed portions that extend radially outward, and one of these recessed portions is adapted to hook the outer end 52 of the lock spring 50 so as to be locked in the rotational direction.

[0054] A through hole 21A that passes through in a circular hole shape in the axial direction is formed in the center (the central position through which the central axis C passes) of the disk portion 21. An operation pin 5A that is inserted into the center of a rotating cam 40 (described later) is inserted into this through hole 21A so as to be rotatable in the axial direction.

[0055] "Paul 30" As shown in Fig. 4 and Fig. 5, each of the three poles 30 is made of a single metal plate member cut into a substantially rectangular plate shape. As shown in Fig. 6, the three poles 30 are set so as to be accommodated one by one in each of the three pole accommodating grooves 24 formed in the above-mentioned guide 20. Thereby, each pole 30 is supported from both sides in the rotational direction by each guide wall 23 on both sides in the rotational direction of each pole accommodating groove 24. As a result, each pole 30 is held so as to be immovable in the rotational direction relative to the guide 20 but slidable along the side surface of each guide wall 23 in the radial direction.

[0056] 7 to 9, each pole 30 is set so as to be housed within the cylinder of the cylindrical portion 13 of the ratchet 10 by fitting the cylindrical portion 13 of the ratchet 10 within the cylinder of the cylindrical portion 22 of the guide 20. As a result, each pole 30 is set so that the external teeth 31 formed on the outer circumferential surface thereof faces the internal teeth 13A formed on the inner circumferential surface of the cylindrical portion 13 of the ratchet 10 from the radially inner side.

[0057] 6, the external teeth 31 formed on the outer peripheral surface of each pole 30 are arranged so as to be continuously aligned over the entire area in the rotational direction of the outer peripheral surface of each pole 30. The outer peripheral surface on which the external teeth 31 of each pole 30 are formed is formed into a convex curved surface shape that curves along the inner peripheral surface of the cylindrical portion 13 on which the internal teeth 13A of the ratchet 10 are formed. The external teeth 31 of each pole 30 and the internal teeth 13A of the ratchet 10 are each shaped so that their tooth surfaces are continuously aligned at a pitch of 2 degrees in the rotational direction.

[0058] Each pole 30 is operated so as to be pushed outward in the radial direction relative to the guide 20 or pulled inward by the rotation of a rotating cam 40 set in the cam accommodating groove 25 of the guide 20. Specifically, as shown in Fig. 10, when the rotating cam 40 rotates counterclockwise in the figure, two locations on the inner circumferential surface of each pole 30 in the rotation direction are pressed from the radially inner side by corresponding convex pressing portions 42 formed on the outer circumferential surface of the rotating cam 40, and the poles 30 are pushed outward in the radial direction.

[0059] As a result, as shown in Fig. 11, each pawl 30 is pressed against the cylindrical portion 13 of the ratchet 10 from the inside in the radial direction. This causes the external teeth 31 of each pawl 30 to mesh with the internal teeth 13A of the cylindrical portion 13 of the ratchet 10. As a result, the rotation of the ratchet 10 relative to the guide 20 is locked. Note that Fig. 10 is a partial cross-sectional view in which the disc portion 11 of the ratchet 10 shown in Fig. 7 is cut away. Also, Fig. 11 is a partial cross-sectional view in which the regulating guide 12 of the ratchet 10 shown in Fig. 10 is replaced by a schematic thick line. Fig. 7 and Figs. 10-11 show the same state (locked state) with each other.

[0060] 12, as the rotating cam 40 rotates clockwise in the figure, the arm-shaped hooked portions 33 extending from the inner peripheral surface in the counterclockwise direction in the figure are hooked onto the corresponding arm-shaped hooking portions 43 extending from the outer peripheral surface of the rotating cam 40, and the pawls 30 are pulled inward in the radial direction. This causes the outer teeth 31 of the pawls 30 to be released from the state in which they were engaged with the inner teeth 13A of the ratchet 10. As a result, the ratchet 10 is unlocked from the guide 20.

[0061] When the ratchet 10 is in the rotation region of the adjustment range shown in Figures 12 to 14, the rotating cam 40 is rotated counterclockwise in the figure, so that the poles 30 are returned to a state (locked state) in which their external teeth 31 mesh with the internal teeth 13A of the ratchet 10. However, when the ratchet 10 is in the rotation region of the free zone shown in Figures 15 to 16, even if the rotating cam 40 is rotated counterclockwise in the figure, the movement of the poles 30 to mesh with the internal teeth 13A of the ratchet 10 is stopped midway.

[0062] Specifically, each pole 30 has a protrusion 34 protruding outward in the axial direction that abuts against the inner peripheral surface of the regulating guide 12 of the ratchet 10, thereby preventing the poles 30 from meshing with the internal teeth 13A of the ratchet 10. The protrusions 34 formed on each pole 30 are formed at different radial positions for each pole 30. This is because the regulating guide 12 with which the protrusions 34 formed on each pole 30 abut is made up of a first regulating guide 12A, a second regulating guide 12B, and a third regulating guide 12C that have inner peripheral surfaces with different radii of curvature.

[0063] 12 to 14, each pawl 30 can be engaged with the internal teeth 13A of the ratchet 10 without interfering with the regulating guide 12. That is, when the ratchet 10 is in the rotation region of the adjustment range, each pawl 30 is in a relationship in which its arrangement in the rotation direction overlaps with a counterpart that is different from the regulating guide 12 (first regulating guide 12A to third regulating guide 12C) that comes into contact with the ratchet 10 when it is in the free zone.

[0064] Specifically, the three poles 30 are classified into a first pole 30A, a second pole 30B, and a third pole 30C in relation to the structure of the regulating guide 12 of the ratchet 10 consisting of three regions (first regulating guide 12A, second regulating guide 12B, and third regulating guide 12C) with different radii of curvature. The first pole 30A is a pole 30 arranged at a position where the first protrusion 34A of the first pole 30A overlaps with the first regulating guide 12A in the rotation direction when the ratchet 10 is in the free zone rotation region shown in Figs. 15 and 16. The first pole 30A is prevented from engaging with the ratchet 10 by the first protrusion 34A coming into contact with the inner peripheral surface of the first regulating guide 12A.

[0065] The second pawl 30B is a pawl 30 that is disposed in a position where its protrusion 34, that is, the second protrusion 34B, overlaps with the second restriction guide 12B in the rotation direction when the ratchet 10 is in the rotation region of the free zone. The second pawl 30B is prevented from engaging with the ratchet 10 by the second protrusion 34B coming into contact with the inner peripheral surface of the second restriction guide 12B.

[0066] The third pawl 30C is a pawl 30 that is disposed at a position where its protrusion 34C overlaps with the third restriction guide 12C in the rotation direction when the ratchet 10 is in the rotation region of the free zone. The third pawl 30C is prevented from engaging with the ratchet 10 by the third protrusion 34C coming into contact with the inner peripheral surface of the third restriction guide 12C.

[0067] When the rotational region of the ratchet 10 switches from the free zone to the adjustment range (see FIGS. 12 to 14), the positional relationship of the three poles 30 to the regulating guide 12 changes as follows: That is, the first pole 30A changes from a state in which its first protrusion 34A overlaps with the first regulating guide 12A in the rotational direction to a state in which its first protrusion 34A overlaps with only the second regulating guide 12B in the rotational direction.

[0068] The second regulating guide 12B is located radially inward of the first protrusion 34A when the first pawl 30A is pulled radially inward by the release operation. The peripheral portion 12D formed on the radially outer side of the second regulating guide 12B with a space therebetween is formed at a position that does not come into contact with the first protrusion 34A even if the first pawl 30A is pushed radially outward to a position where it meshes with the ratchet 10. For this reason, the first pawl 30A can be meshed with the ratchet 10 without interfering with the regulating guide 12.

[0069] In addition, when the rotational region of the ratchet 10 switches from the free zone to the adjustment range, the second pawl 30B changes from a state in which its second protrusion 34B overlaps with the second regulating guide 12B in the rotational direction to a state in which its second protrusion 34B overlaps with only the third regulating guide 12C in the rotational direction. The third regulating guide 12C is located radially outward from the second regulating guide 12B, and is not in contact with the second protrusion 34B even if the second pawl 30B is pushed radially outward to a position where it meshes with the ratchet 10.

[0070] Similarly, when the rotational region of the ratchet 10 switches from the free zone to the adjustment range, the third pawl 30C changes from a state in which its third protrusion 34C overlaps with the third restriction guide 12C in the rotational direction to a state in which its third protrusion 34C overlaps with only the first restriction guide 12A in the rotational direction. The first restriction guide 12A is located radially outward of the third restriction guide 12C, and is in a relationship such that even if the third pawl 30C is pushed radially outward to a position where it meshes with the ratchet 10, it will not come into contact with the third protrusion 34C.

[0071] In this way, by returning the ratchet 10 from the free zone to the adjustment range, each pole 30 can mesh with the ratchet 10 without interfering with the regulating guide 12. In detail, among each pole 30, only the first pole 30A is configured such that its first protrusion 34A is positioned radially outward of the second regulating guide 12B with which it overlaps in the rotational direction.

[0072] 15, however, as the ratchet 10 rotates from the free zone back into the adjustment range, the first pawl 30A is able to move its first protrusion 34A through the radially outer region (gap T) of the second restriction guide 12B to a position where it overlaps with the second restriction guide 12B in the rotational direction. This makes it possible to ensure a wide region where the first protrusion 34A and the second restriction guide 12B overlap in the rotational direction as the adjustment range of the ratchet 10.

[0073] Specifically, the adjustment range of the ratchet 10 can be set at maximum within the following range: That is, the adjustment range of the ratchet 10 can be set at maximum from the position where the first restriction guide 12A comes off the first protrusion 34A of the first pole 30A in the clockwise direction as shown in Fig. 12 to the position where the side surface of the second restriction guide 12B abuts against the third protrusion 34C of the third pole 30C in the clockwise direction as shown in Fig. 14.

[0074] The free zone of the ratchet 10 can be set at maximum within the following range: That is, the position where the first restriction guide 12A deviates from the first protrusion 34A of the first pole 30A in the clockwise direction as shown in Fig. 12 is set as the boundary position, and the free zone of the ratchet 10 can be set at maximum from there to the position where the side surface of the second restriction guide 12B abuts against the third protrusion 34C of the third pole 30C in the counterclockwise direction as shown in Fig. 16.

[0075] That is, even though the three poles 30 are evenly spaced in the rotational direction, the combined operating angle of the adjustment range and free zone of the recliner 4 can be set to 120 degrees or more. More specifically, the adjustment range and free zone of the recliner 4 can each be set to 90 degrees or more.

[0076] 11, the above-mentioned three poles 30 are formed to have the same shape and size except for their protrusions 34. The protrusions 34 on each pole 30 are formed at different positions as follows. That is, among the three protrusions 34, namely the first protrusion 34A on the first pole 30A, the second protrusion 34B on the second pole 30B, and the third protrusion 34C on the third pole 30C, the first protrusion 34A is formed at the outermost position in the radial direction on the pole 30 (first pole 30A).

[0077] Also, the second protrusion 34B is formed at the innermost position in the radial direction of the pole 30 (second pole 30B). Specifically, the second protrusion 34B is formed at a position in contact with the inner peripheral edge of the second pole 30B. And the third protrusion 34C is formed at a radial intermediate position between the first protrusion 34A and the second protrusion 34B of the pole 30 (third pole 30C).

[0078] As a result, in each pole 30, the outer peripheral surface of the first projection 34A is located at the outermost position in the radial direction, followed by the outer peripheral surface of the third projection 34C, and the outer peripheral surface of the second projection 34B is located at the innermost position in the radial direction. Each projection 34 is half-punched so as to have the same axial projection length and rotational projection width from each pole 30.

[0079] Incidentally, as shown in Fig. 12, when each pawl 30 is released and the ratchet 10 is rotated counterclockwise (switching from the adjustment range to the free zone), it is possible that the ratchet 10 rotates toward the free zone while each pawl 30 is not fully retracted to the release position, i.e., in a so-called half-locked state. In that case, the projections 34 of each pawl 30 are simultaneously abutted against the rising side faces of the regulating guides 12 adjacent to each other in the rotation direction.

[0080] Therefore, compared to a configuration in which the above-mentioned collision occurs only at one point between any of the poles 30, the load caused by the collision can be distributed to three points and appropriately received. Also, in the free zone, the protrusions 34 of each pole 30 are simultaneously abutted against the inner peripheral surface of the regulating guide 12. Therefore, even if the reclining lever 5 (see FIG. 1) does not return completely to the initial position in the free zone because the engagement of each pole 30 is interrupted midway and an external force is mistakenly applied to push it back, the external force can be distributed to three points and appropriately received.

[0081] "Rotating Cam 40" As shown in Fig. 4 and Fig. 5, the rotating cam 40 is made of a single metal plate member cut into a substantially circular disk shape. The rotating cam 40 has a shape having substantially the same plate thickness as each of the poles 30. As shown in Fig. 6, the rotating cam 40 is set in a cam accommodating groove 25 formed in the circular disk portion 21 of the guide 20. As a result, the rotating cam 40 is arranged so that the poles 30 are lined up at its radially outer position.

[0082] A through hole 41 that penetrates in the axial direction in a hexagonal shape is formed in the center of the rotating cam 40 (the central position through which the central axis C passes). An operation pin 5A having a corresponding hexagonal shaft portion is inserted axially into this through hole 41 and assembled so as to be integrated in the rotational direction.

[0083] The operating pin 5A is an operating member that is connected integrally with the operating shaft (not shown) of the reclining lever 5 described above in Fig. 1. When the reclining lever 5 is pulled up, the operating pin 5A rotates integrally therewith, and rotates the rotating cam 40 integrally therewith. Specifically, as shown in Fig. 12, when the reclining lever 5 is pulled up, the operating pin 5A rotates the rotating cam 40 in the clockwise direction shown in the figure, that is, in a rotational direction that pulls each pole 30 radially inward (release direction).

[0084] The operating pin 5A is connected to the operating pin 5A inserted into the recliner 4 on the inside (left side) of the vehicle described above in Fig. 1 via a connecting rod 5B so that they are integrated with each other. As a result, when the reclining lever 5 is pulled up, both operating pins 5A are rotated simultaneously, and the rotating cams 40 of both recliners 4 are released simultaneously.

[0085] As shown in Fig. 6, the rotating cam 40 has three hooking parts 43 that extend like arms in the clockwise direction in the figure at three positions on the outer circumferential surface in the rotational direction. As shown in Fig. 12, the rotating cam 40 is operated so that the hooking parts 43 are hooked onto the corresponding hooked parts 33 of each pole 30 by rotating the rotating cam 40 in the clockwise direction in the figure by the operating pin 5A, and these are pulled inward in the radial direction.

[0086] 11, the rotating cam 40 is rotated counterclockwise by the operating pin 5A, whereby each hooking portion 43 is disengaged from the hooked portion 33 of each pole 30. At the same time, the rotating cam 40 presses two portions close to both ends in the rotation direction of each corresponding pole 30 from the inside in the radial direction by each convex pressing portion 42 that bulges out from the outer circumferential surface of each hooking portion 43 and the outer circumferential surface in the vicinity of the hooking portion 43. As a result, the rotating cam 40 pushes each pole 30 outward in the radial direction to engage with the internal teeth 13A of the ratchet 10.

[0087] 5, the operation pin 5A is set so that a part of its hexagonal shaft portion, which is fitted into the through hole 41 of the rotating cam 40, protrudes from the rotating cam 40 to the outside in the axial direction facing the guide 20. The inner end portion 51 of the lock spring 50 is fitted into the hexagonal shaft portion of the operation pin 5A protruding from the rotating cam 40 so as to be integral with the hexagonal shaft portion in the rotational direction.

[0088] As described above in Fig. 4, the lock spring 50 has its outer end 52 hooked and fixed in one of the three recessed portions extending from the spring receiving groove 26 of the guide 20. By assembling this lock spring 50, a spring force is constantly applied to the operating pin 5A, which urges the rotating cam 40 in the rotational direction of the locking operation (counterclockwise direction in the figure) relative to the guide 20. Due to this spring force, as shown in Fig. 11, the rotating cam 40 constantly applies a pressing force from the radial inside to each of the pawls 30, thereby holding them in mesh with the internal teeth 13A of the ratchet 10.

[0089] 《Outer Ring 60》 As shown in Figures 4 and 5, the outer ring 60 is made of a single metal thin plate member punched into a ring plate shape. The outer ring 60 is drawn so that its outer periphery protrudes in two stages into a stepped cylindrical shape in the axial direction. As a result, the outer ring 60 is formed into a shape having a flange portion 61 that spreads out in the radial direction like a hollow disk, and a step portion 62 that extends from the outer periphery of the flange portion 61 in the axial direction like a stepped cylinder.

[0090] The outer circumferential ring 60 has a connecting portion 63 at the end of the stepped portion 62 on the tube tip side, which is bent radially inward and crimped after assembly to the ratchet 10 and the guide 20. The outer circumferential ring 60 is mounted so as to straddle the cylindrical portion 13 of the ratchet 10 and the cylindrical portion 22 of the guide 20 from the outer circumferential side as follows. First, as shown in Fig. 6, the lock spring 50, the three poles 30, and the rotating cam 40 are each set in the guide 20. Next, as shown in Fig. 8, the ratchet 10 is assembled to the guide 20.

[0091] Then, the outer circumferential ring 60 is set so as to straddle the cylindrical portion 13 of the ratchet 10 and the cylindrical portion 22 of the guide 20 from the outer circumferential side. Specifically, the ratchet 10 and the guide 20 are passed through the cylinder of the outer circumferential ring 60 so that the flange portion 61 of the outer circumferential ring 60 abuts on the cylindrical portion 13 of the ratchet 10 from the outside in the axial direction.

[0092] As a result, the stepped portion of the stepped portion 62 of the outer circumferential ring 60 extending in a stepped cylindrical shape is abutted against the cylindrical portion 22 of the guide 20 from the inside in the axial direction, and the end portion of the stepped portion 62 on the tube tip side is set in a state in which it overhangs the cylindrical portion 22 of the guide 20 to the outside in the axial direction. Next, the overhanging end portion of the stepped portion 62 is crimped so as to be bent radially inward. This forms the crimped portion as a connecting portion 63 that is connected to the stepped portion of the stepped portion 62 so as to sandwich the cylindrical portion 22 of the guide 20 in the axial direction.

[0093] By the above assembly, the outer circumferential ring 60 is integrally joined to the cylindrical portion 22 of the guide 20. The outer circumferential ring 60 then presses the cylindrical portion 13 of the ratchet 10 from the outside in the axial direction by means of its flange portion 61. As a result, the outer circumferential ring 60 holds the ratchet 10 against the guide 20 so that it does not come off to the outside in the axial direction.

[0094] To summarize the above, the recliner 4 according to this embodiment has the following configuration. Note that, in the following description, the reference characters in parentheses correspond to the respective components shown in the above embodiment.

[0095] That is, the seat reclining device (4) has a ratchet (10), a guide (20), and multiple poles (30). The ratchet (10) and the guide (20) are connected to each other so that they can rotate around the central axis (C) of the reclining. The multiple poles (30) are supported on both sides in the rotational direction by the guide (20), and mesh with the ratchet (10) by moving outward in the radial direction, thereby locking the rotation.

[0096] The ratchet (10) has a regulating guide (12) that prevents the engagement of the multiple pawls (30) by pushing them out in a free zone, which is a predetermined rotational region, by contacting the inner peripheral surface. The multiple pawls (30) include a first pawl (30A) and a second pawl (30B) that are aligned in the rotational direction. The regulating guide (12) has a first regulating guide (12A) and a second regulating guide (12B) that are aligned and separated in the rotational direction so that their inner peripheral surfaces are curved with different radii of curvature around a central axis (C).

[0097] The first restriction guide (12A) prevents the first pole (30A) from engaging by bringing a first protrusion (34A) protruding in the axial direction from the first pole (30A) into contact with its inner peripheral surface. The second restriction guide (12B) prevents the second pole (30B) from engaging by bringing a second protrusion (34B) protruding in the axial direction from the second pole (30B) into contact with its inner peripheral surface. The second restriction guide (12B) has an inner peripheral surface and an outer peripheral surface located radially inward from the inner peripheral surface of the first restriction guide (12A), and thereby passes the first protrusion (34A) in the rotational direction from its radially outer region when the ratchet (10) leaves the free zone and enters an adjustment range that allows engagement.

[0098] According to the above configuration, when the ratchet (10) is in the free zone, the first protrusion (34A) of the first pole (30A) and the second protrusion (34B) of the second pole (30B) can be brought into contact with the first regulating guide (12A) and the second regulating guide (12B), respectively, to prevent meshing. Also, when the ratchet (10) is in the adjustment range, the first protrusion (34A) of the first pole (30A) can be passed outside the second regulating guide (12B), so that the first protrusion (34A) can be meshed with the second regulating guide (12B) even if the arrangement of the first protrusion (34A) overlaps with the second regulating guide (12B) in the rotational direction. As a result, even if multiple poles (30) are provided, a wide adjustment range and free zone can be set for the ratchet (10).

[0099] The plurality of poles (30) further includes a third pole (30C) aligned in the rotational direction with the first pole (30A) and the second pole (30B). The regulating guide (12) further includes a third regulating guide (12C) aligned in the rotational direction with the first regulating guide (12A) and the second regulating guide (12B) and having an inner peripheral surface curved around the central axis (C). The third regulating guide (12C) has an inner peripheral surface located radially inward from the inner peripheral surface of the first regulating guide (12A) and radially outward from the inner peripheral surface of the second regulating guide (12B). The third regulating guide (12C) prevents the third pole (30C) from engaging by abutting a third protrusion (34C) protruding in the axial direction from the third pole (30C) against its inner peripheral surface.

[0100] According to the above configuration, even in a configuration in which three poles (30) are lined up in the rotational direction, each pole (30) can be abutted against the regulating guide (12) in the free zone to prevent meshing, and a wide adjustment range and free zone can be set for the ratchet (10).

[0101] The ratchet (10) also has a disc portion (11) that expands radially in a disc shape and has a regulating guide (12) that protrudes axially, and a cylindrical portion (13) that protrudes axially from the outer periphery of the disc portion (11) in a cylindrical shape along the outer periphery and has internal teeth (13A) along its inner surface for engaging with a plurality of poles (30).

[0102] The first restriction guide (12A) and the third restriction guide (12C) protrude in the axial direction from the outer circumferential edge of the disc portion (11) which is radially inward from the cylindrical portion (13). The second restriction guide (12B) protrudes in the axial direction from the disc portion (11) at a position radially inward from the first restriction guide (12A) and the third restriction guide (12C) so as to be in the form of a floating island separated from the first restriction guide (12A) and the third restriction guide (12C).

[0103] According to the above configuration, the first restriction guide (12A), the second restriction guide (12B), and the third restriction guide (12C) can be simply and appropriately formed by half-punching the ratchet (10). Even if the second restriction guide (12B) is formed on the ratchet (10), the internal teeth (13A) can be appropriately formed at a radially outer position thereof.

[0104] Other embodiments Although one embodiment of the present invention has been described above, the present invention can be embodied in various forms other than the above embodiment.

[0105] 1. The seat reclining device of the present invention may be applied to seats installed in vehicles other than automobiles, such as trains, as well as seats installed in vehicles other than vehicles, such as airplanes and ships. The seat reclining device may also be applied to seats installed in various facilities, such as sports facilities, theaters, concert halls, and event venues, as well as seats used in vehicles other than vehicles, such as massage seats.

[0106] The seat reclining device may be one that connects the seat back to the seat cushion so that the backrest angle can be adjusted, or one that connects the seat back to a base such as a bracket fixed to the vehicle body so that the backrest angle can be adjusted. The seat reclining device may have a configuration in which a guide is connected to the seat back and a ratchet is connected to the seat cushion or a base. The seat reclining device may be one that is used to adjust the angle of the ottoman or armrest, in addition to adjusting the angle of the seat back.

[0107] 2. The poles may be arranged in a line of two or four or more in the rotation direction. The arrangement of the poles in the rotation direction is not limited to being evenly arranged, and they may be arranged offset in the rotation direction as shown in JP 2015-029635 A. The cam that pushes the poles outward in the rotation direction may be a rotating cam or a slide cam as shown in JP 2014-234136 A. [Explanation of symbols]

[0108] 1 sheet 2 Seat back 2F Side Frame 3 Seat cushion 3F Reclining plate 4 Recliner (seat reclining device) 5 Reclining lever 5A Operation Pin 5B Connecting rod 6 Return spring 10. Ratchet 11 Disc section 11A through hole 12 Regulatory Guide 12A First Regulatory Guide 12B Second Regulatory Guide 12C Third Regulation Guide 12D Periphery 13 Cylindrical section 13A Internal teeth 20 Guide 21 Disc section 21A through hole 22 Cylindrical part 23 Guide Wall 24 Pole receiving groove 25 Cam receiving groove 26 Spring receiving groove 30 Paul 30A 1st Pole 30B 2nd Pole 30C 3rd Pole 31 Outer teeth 33 Hooked part 34 Protrusion 34A 1st protrusion 34B 2nd protrusion 34C 3rd protrusion 40 Rotating Cam 41 Through hole 42 Pressing part 43 Hook section 50 Rock Spring 51 Inner end 52 Outer edge 60 Outer Ring 61 Flange 62 Step 63 Joint C center axis T Gap

Claims

1. A seat reclining device, A ratchet and a guide connected to each other so as to be rotatable around a central axis of reclining; a plurality of pawls supported by the guide from both sides in the rotational direction and engaged with the ratchet by being pushed outward in the radial direction to lock the rotation; The ratchet has a regulating guide that prevents meshing caused by pushing out the plurality of pawls in a free zone, which is a predetermined rotation region, by contacting the inner circumferential surface, The plurality of poles include a first pole and a second pole aligned in a rotational direction, The regulating guide includes a first regulating guide and a second regulating guide that are arranged in a rotational direction and separated from each other so that the inner circumferential surfaces are curved with different radii of curvature around the central axis, the first restriction guide prevents engagement of the first pole by contacting a first protrusion protruding from the first pole in the axial direction with the inner peripheral surface of the first restriction guide; A seat reclining device in which the second restricting guide prevents engagement of the second pole by abutting a second protrusion protruding axially from the second pole against its inner circumferential surface, and has inner and outer circumferential surfaces at a position radially inward relative to the inner circumferential surface of the first restricting guide, thereby allowing the first protrusion to pass in a rotational direction from its radially outer region when the ratchet leaves the free zone and enters an adjustment range allowing engagement.

2. The seat reclining device according to claim 1, The plurality of poles further includes a third pole aligned in a rotational direction with the first pole and the second pole, The regulating guide further includes a third regulating guide that is aligned with the first regulating guide and the second regulating guide in a rotational direction and has an inner peripheral surface that is curved around the central axis, A seat reclining device in which the third restricting guide has an inner surface that is radially inward from the inner surface of the first restricting guide and radially outward from the inner surface of the second restricting guide, and a third protrusion protruding axially from the third pole is abutted against the inner surface to prevent engagement of the third pole.

3. The seat reclining device according to claim 2, The ratchet has a disk portion that extends in a radial direction in a disk shape and has the regulating guide protruding in the axial direction, and a cylindrical portion that protrudes in a cylindrical shape in the axial direction from an outer circumferential edge of the disk portion along the outer circumferential edge and has internal teeth along an inner circumferential surface for meshing with the plurality of poles, A seat reclining device in which the first restricting guide and the third restricting guide protrude axially from the outer peripheral edge of the disc portion, which is radially inward from the cylindrical portion, and the second restricting guide protrudes axially from the disc portion at a position radially inward from the first restricting guide and the third restricting guide so as to be like a floating island separated from the first restricting guide and the third restricting guide.

Images