Seat reclining device

Abstract

To provide a seat reclining device capable of suppressing bidirectional tilting of pawls when a lock is released.SOLUTION: A seat reclining device 4 includes: a ratchet 10 and a guide 20 connected so as to be rotatable relative to each other around a central axis; a cam 40 assembled to the guide 20 so as to be rotatable around the central axis; three pawls 30 supported by the guide 20 from both sides in a rotational direction and pushed radially outward by rotation of the cam 40 in one direction to engage with the ratchet 10 and lock rotation; and engaging portions F formed between the cam 40 and the respective pawls 30. The engaging portions F engage such that the pawls 30 are pulled radially inward by rotation of the cam 40 in the other direction. The engaging portions F have an engaging structure that brings the cam 40 into contact with the pawls 30 from outside in a radial direction at two positions sandwiching the center in the rotational direction of each pawl 30.SELECTED DRAWING: Figure 11

Description

[Technical Field]

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

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

[0003] Two pawls are provided between the ratchet and the guide to lock the relative rotation between them. Each pawl is supported on both sides in the rotational direction so that it can only move radially inward and outward relative to the guide.

[0004] When a cam located at the center of the guide is rotated in one direction by a spring force, each pawl is pushed outward in the radial direction and engages with the ratchet, thereby locking the ratchet and guide from rotating relative to each other via each cam.

[0005] As the cam is rotated in the other direction, each pawl is pulled radially inward and disengaged from the ratchet, thereby releasing the rotational lock between the ratchet and the guide.

[0006] Specifically, when each pole is pulled inward in the radial direction by the cam, it also receives a force from the cam that tilts it in the rotational direction. As a result, even if each pole is subjected to a load that tilts it in the rotational direction due to the back load (rear load) applied to the ratchet, the cam pulls it inward while receiving a force that cancels out that tilt. As a result, each pole can be pulled inward with a relatively light force, without being pressed strongly against the guide walls on either side. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Japanese Patent Application Laid-Open No. 2001-265 Summary of the Invention [Problem to be solved by the invention]

[0008] The configuration described in Patent Document 1 cannot retract the poles to prevent them from tilting when a forward load is applied to the ratchet. Therefore, the present invention provides a seat reclining device that can prevent the poles from tilting in both directions when the lock is released. [Means for solving the problem]

[0009] To solve the above problems, the seat reclining device of the present invention employs the following means.

[0010] That is, the first invention of the present invention is a seat reclining device comprising: a ratchet and a guide connected to each other so that they can rotate around a central axis of reclining; a cam assembled to the guide so that it can rotate around the central axis; at least one pole supported by the guide on both sides in the rotational direction and pushed radially outward by rotation of the cam in one direction to engage with the ratchet to lock its rotation; and an engagement portion formed between the pole and a retraction member constituting either the cam or a member integrated therewith, which engages to retract the pole radially inward by rotation of the cam in the other direction, wherein the engagement portion causes the retraction member to abut against the pole from the radial outside at two positions sandwiching the center of the rotational direction of the pole.

[0011] According to the first aspect of the present invention, when the pawl is pulled inward by the rotation of the cam, the engaging portion prevents the pawl from tilting in the rotation direction. Therefore, regardless of the rotation direction of the ratchet, tilting of the pawl in either direction during unlocking can be suppressed.

[0012] The second invention of the present invention is a seat reclining device according to the first invention, wherein the engagement portion has a retraction hole formed in the pole and recessed in the axial direction, and two retraction pins that protrude axially so as to enter the retraction hole from two positions in the rotational direction of the cam, and the rotation of the cam in the other direction causes the two retraction pins to abut from the radial outside against two inner hole surfaces aligned in the rotational direction of the retraction hole, and the two inner hole surfaces are shaped to be rotationally symmetrical to each other around the central axis.

[0013] According to the second aspect of the present invention, the pole can be pulled straight inward in the radial direction directly by the cam.

[0014] A third invention of the present invention is a seat reclining device according to the first or second invention, wherein the poles are provided in multiple positions in the rotational direction, and the engagement portions are provided between all of the poles and the retractable members.

[0015] According to the third aspect of the present invention, tilting of all of the poles in both directions during unlocking can be suppressed, thereby appropriately reducing the operating load for unlocking. [Brief explanation 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. [Figure 2] FIG. [Figure 3] FIG. 3 is a perspective view of FIG. 2 as seen from the opposite side. [Figure 4] FIG. [Figure 5] FIG. 5 is an exploded perspective view of FIG. 4 as seen from the opposite side. [Figure 6] FIG. 10 is a perspective view of the poles and cams assembled to the guide. [Figure 7] FIG. [Figure 8] FIG. 8 is a cross-sectional view taken along line VIII-VIII in FIG. 7. [Figure 9] FIG. 8 is a partial cross-sectional view of the ratchet shown in FIG. 7 with the disc portion cut away. [Figure 10] FIG. 4 is a schematic diagram illustrating a locked state of the seat reclining device. [Figure 11] FIG. 4 is a schematic diagram illustrating a seat reclining device in a released state. [Figure 12] FIG. 10 is a schematic diagram showing a state in which the ratchet is rotated into a free zone. DETAILED DESCRIPTION OF THE INVENTION

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

[0018] (First embodiment) <<General 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 12. 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 a specific reference drawing is not indicated or when there is no reference symbol corresponding to a reference drawing, any of Figures 1 to 12 will be referenced as appropriate.

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

[0020] Specifically, the recliners 4 are respectively assembled 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 frames of the seat cushion 3. As a result, each recliner 4 connects the side frames 2F of the seat back 2 to the reclining plates 3F so as to be rotatable about the same central axis C extending in the seat width direction.

[0021] Each recliner 4 is normally held in a locked state, fixing the angle of the seatback 2. When the user pulls up the reclining lever 5 located on the outer side (right side) of the seat cushion 3, the recliners 4 are simultaneously released from their locked state. This switches each recliner 4 to a state where the angle of the seatback 2 can be adjusted in the fore-and-aft direction of the seat.

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

[0023] Specifically, this free zone is set to a rotation range in which the seat back 2 can be 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] On the other hand, the rotation range in which the seat back 2 is tilted backward from a position in a substantially upright position is 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 attached between each side frame 2F of the seat back 2 and each reclining plate 3F located outside of the side frames 2F. The force of these return springs 6 releases the locked state of each recliner 4, causing the seat back 2 to rise up to a position where it will contact the back of a seated occupant.

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

[0027] 2 and 3, each recliner 4 specifically has a disc-shaped ratchet 10 coupled to the outer surface of each side frame 2F (see FIG. 1) and a disc-shaped guide 20 coupled to the inner surface of each reclining plate 3F (see FIG. 1). Each recliner 4 is configured to lock or unlock the reclining angle of the seat back 2 (see FIG. 1) by switching between locking and unlocking 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 is configured symmetrically to the other. Therefore, the following will describe in detail the configuration of the recliner 4 located on the outer side (right side) of the vehicle as shown in Figures 2 and 3.

[0029] As shown in Figures 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 pawls 30 assembled between ratchet 10 and guide 20, and a cam 40 that pushes and pulls these inward and outward in the radial direction. Here, cam 40 corresponds to the "retraction member" of the present invention.

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

[0031] Ratchet 10 Ratchet 10 is made of a single metal plate member cut into a roughly circular disk shape. Ratchet 10 has a circular disk portion 11 that extends radially in a circular disk shape. Ratchet 10 also has a free zone protrusion 12 that is half-punched from the outer periphery of circular disk portion 11 so as to protrude concentrically inward in the axial direction, facing guide 20.

[0032] The free zone protrusion 12 has an inner peripheral surface divided into three regions that curve at different radii of curvature around the central axis C. When the recliner 4 is in the free zone, the free zone protrusion 12 functions as an engagement prevention portion that prevents each pawl 30 from engaging with the ratchet 10 by abutting against a protrusion 34 protruding from each pawl 30.

[0033] The ratchet 10 also has a cylindrical portion 13 that is half-blanked so as to protrude further inward in the axial direction from the outer periphery of the free zone projection 12 in a concentric cylindrical shape. As shown in Fig. 5, internal teeth 13A are formed on the inner circumferential surface of the cylindrical portion 13 so as to be continuously aligned over the entire area in the rotational direction. The internal teeth 13A of the cylindrical portion 13 serve as tooth surfaces for engaging external teeth 31 formed on the outer circumferential surfaces of each of the pawls 30, which will be described later, from the radially inner side.

[0034] 4 and 5, a through-hole 11A that passes through in a circular hole shape in the axial direction is formed in the center (position on the central axis C) of the disc portion 11. An operation pin 5A (see FIG. 1) that is inserted into the center of a cam 40 (described later) is inserted into this through-hole 11A so as to be rotatable in the axial direction.

[0035] Guide 20 The guide 20 is made of a single metal plate member cut into a roughly circular disk shape that is slightly larger than the ratchet 10. The guide 20 has a circular disk portion 21 that extends in a circular 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 circular disk portion 21 so as to protrude concentrically inward in the axial direction, facing the ratchet 10.

[0036] The guide 20 is set so that the cylindrical portion 13 of the ratchet 10 is loosely fitted in the axial direction within the cylindrical portion 22 of the guide 20. As a result, the guide 20 and the ratchet 10 are assembled in a state where they support each other internally and externally so as to be rotatable relative to each other.

[0037] After this assembly, an outer circumferential ring 60 (described later) is mounted between the outer circumferential portions of 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 circumferential side. This allows the guide 20 and the ratchet 10 to be held in a state where they can rotate relative to each other via the outer circumferential ring 60 and are prevented from coming off in the axial direction (see FIGS. 2 to 3 and 8).

[0038] 4, the guide 20 has guide walls 23 that are half-punched so as to protrude inward in the axial direction in a roughly fan-like shape at three positions in the rotational direction of the disk portion 21. These guide walls 23 are formed in a shape that is three-fold symmetric (rotationally symmetric) around the central axis C.

[0039] The outer peripheral surfaces of these guide walls 23 are curved at the same radius of curvature around the central axis C. When the cylindrical portion 13 of the ratchet 10 is fitted into the cylindrical portion 22 of the guide 20, each guide wall 23 is assembled so that it fits into the cylindrical portion 13 of the ratchet 10 with a small radial gap.

[0040] 6, the guide 20 is configured such that the three guide walls 23 form concave pole accommodating grooves 24 between them, each capable of accommodating one of three poles 30. The guide 20 is also configured such that a concave cam accommodating groove 25 is formed in the center of the disk portion 21 surrounded by the three guide walls 23, and is capable of rotatably accommodating a cam 40.

[0041] Each guide wall 23 is shaped so that its side surface facing the rotation direction forms a guide surface parallel to the side surface in the rotation direction of each pole 30 housed in each pole housing groove 24. As a result, each guide wall 23 supports each of the three poles 30 housed in each pole housing groove 24 from both sides in the rotation direction so that each pole can slide only radially inward and outward.

[0042] 4, a spring accommodating hole 26 that penetrates in the axial direction in a circular hole shape is formed in the center of the disk portion 21 where the cam accommodating groove 25 of the guide 20 is formed. The spring accommodating hole 26 has a shape that allows a lock spring 50, which will be described later, to be accommodated inside the hole.

[0043] Specifically, spring accommodating hole 26 has an expanded hole that extends radially outward in an elongated shape. Spring accommodating hole 26 accommodates lock spring 50 in a state where outer end 52 is fixed to guide 20 by hooking outer end 52 of lock spring 50 housed inside the hole into the expanded hole.

[0044] "Paul 30" As shown in Figures 4 and 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 Figure 6, the three poles 30 are set so that one pole is accommodated in each of the three pole accommodating grooves 24 formed in the guide 20. As a result, each pole 30 is supported from both sides in the rotational direction by the guide walls 23 that face both sides in the rotational direction of each pole accommodating groove 24. As a result, each pole 30 is immovable in the rotational direction relative to the guide 20, but is held so as to be slidable along the side surfaces of the guide walls 23 in the radial direction.

[0045] 7 and 8, each pole 30 is set so as to be housed within the cylindrical portion 13 of the ratchet 10 by fitting the cylindrical portion 13 of the ratchet 10 within the cylindrical portion 22 of the guide 20. As a result, each pole 30 is set so that the external teeth 31 formed on its outer circumferential surface face the internal teeth 13A formed on the inner circumferential surface of the cylindrical portion 13 of the ratchet 10 from the radially inside.

[0046] 5, the external teeth 31 formed on the outer peripheral surface of each pawl 30 are arranged so as to be continuously aligned over the entire rotational direction of the outer peripheral surface of each pawl 30. The outer peripheral surface on which the external teeth 31 of each pawl 30 are formed has 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 pawl 30 and the internal teeth 13A of the ratchet 10 each have a shape such that their tooth surfaces are continuously aligned at a pitch of 2 degrees in the rotational direction.

[0047] As shown in Fig. 9, each pole 30 is operated so as to be pushed outward in the radial direction relative to the guide 20 or pulled inward in the radial direction relative to the guide 20 by the rotation of a cam 40 set in the cam accommodating groove 25 of the guide 20. Specifically, as shown in Fig. 10, as the cam 40 rotates counterclockwise in the drawing, 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 cam 40, and the poles are pushed outward in the radial direction.

[0048] This causes each of the pawls 30 to be pressed against the cylindrical portion 13 of the ratchet 10 from the inside in the radial direction, and this causes the external teeth 31 of each of the pawls 30 to mesh with the internal teeth 13A of the cylindrical portion 13 of the ratchet 10. As a result, the ratchet 10 is locked against rotation relative to the guide 20.

[0049] 9 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. 10 is a partial cross-sectional view in which the free zone protrusion 12 of the ratchet 10 shown in Fig. 9 is replaced by a schematic thick line. Fig. 7 and Figs. 9-10 show the same state (locked state).

[0050] 11, as the cam 40 rotates clockwise in the drawing, each of the pawls 30 is pulled radially inward through the engagement of each of the engagement portions F formed with the cam 40. This causes each of the pawls 30 to be disengaged from the state in which its external teeth 31 are engaged with the internal teeth 13A of the ratchet 10. As a result, the ratchet 10 is released from the lock on the guide 20.

[0051] As shown in Fig. 6, each engagement portion F is composed of a long-hole-shaped retraction hole 33 formed in each pole 30 and penetrating in the axial direction, and retraction pins 43 protruding in pairs in the axial direction from three positions in the rotation direction of the cam 40 so as to enter the corresponding retraction hole 33. As shown in Fig. 11, when the cam 40 rotates clockwise in the drawing, each pole 30 has the retraction pins 43 protruding from the cam 40 abutting against the inner peripheral surface 33A of each retraction hole 33 from the outside in the radial direction, two by two.

[0052] More specifically, each retraction pin 43 protruding from the cam 40 has a round pin-like shape protruding in the axial direction. Each retraction pin 43 is brought into line contact with the inner peripheral surface 33A of the retraction hole 33 of each pole 30 at two positions sandwiching the center of the rotation direction of each pole 30.

[0053] This prevents the poles 30 from tilting in the rotational direction when the poles 30 are pulled inward by the rotation of the cam 40. Therefore, even if an operation to pull the poles 30 inward is performed while a load in the rotational direction is applied to the ratchet 10, the poles 30 can be pulled inward without tilting in the rotational direction.

[0054] Specifically, an example of a situation in which a rotational load is applied to the ratchet 10 is when the weight of a seated occupant is applied to the seat back 2 (see FIG. 1). In this case, as shown in FIG. 11, a load is applied to the ratchet 10 in the rotational direction, rotating it clockwise relative to the guide 20.

[0055] An example of a situation in which a rotational load is applied to the ratchet 10 is when a biasing force in the forward rotation direction is applied to the seat back 2 (see FIG. 1) from the return spring 6. In this case, as shown in FIG. 11, a rotational load is applied to the ratchet 10 in the counterclockwise direction relative to the guide 20.

[0056] As described above, even if the pawls 30 are pulled inward while a load is applied to the ratchet 10 in one or the other direction of rotation, the pawls 30 can be pulled inward straight without tilting in the direction of rotation. Therefore, the pawls 30 can be pulled inward without being pressed strongly against the guide walls 23 on either side. As a result, the operational load required for unlocking can be appropriately reduced.

[0057] The retraction pins 43 protruding two by two from each of the three positions in the rotational direction of the cam 40 are formed in positions where they simultaneously abut against the corresponding hole inner circumferential surface 33A when each pole 30 is in a straight position without tilting in the rotational direction with respect to the retraction hole 33 of the corresponding pole 30. Furthermore, the two hole inner circumferential surfaces 33A formed in the retraction hole 33 of each pole 30 and aligned in the rotational direction so that each retraction pin 43 abuts two by two are formed in shapes that are rotationally symmetrical to each other around the central axis C.

[0058] These configurations allow each pawl 30 to be pulled straight inward in the radial direction as the cam 40 rotates. More specifically, when each pawl 30 is pulled inward while a load is being applied to the ratchet 10 in one or the other direction of rotation, the pawl 30 is subjected to a force that tilts it in the direction of the load applied to the ratchet 10 due to its engagement with the ratchet 10.

[0059] However, regardless of the load applied to tilt each pole 30 in either direction, one of the two retractable pins 43 that abut each pole 30 functions to prevent the tilt. For example, when each pole 30 tries to tilt counterclockwise in the figure, the retractable pin 43 located on the clockwise side in the figure out of the pair of retractable pins 43 aligned in the rotational direction functions to prevent the tilt of each pole 30.

[0060] Specifically, the counterclockwise direction in the figure, which is the tilt direction of each pole 30, and the clockwise direction in the figure, which is the rotation direction for unlocking the cam 40, are opposite rotation directions. In this case, as the rotation of the cam 40 progresses, a force acts to return the tilt of each pole 30 to its original position, and the tilt of each pole 30 can be appropriately suppressed.

[0061] Furthermore, when each pole 30 tries to tilt clockwise in the figure, the retraction pin 43 located counterclockwise in the pair of retraction pins 43 aligned in the rotation direction functions to prevent the tilt. In detail, in this case, the clockwise direction in the figure, which is the tilt direction of each pole 30, and the clockwise direction in the figure, which is the rotation direction for unlocking the cam 40, have the same rotational direction relationship.

[0062] However, even in this case, as the cam 40 continues to rotate, the retraction pins 43 located on the counterclockwise side in the drawing exert a force that attempts to return the tilt of each pole 30 to its original position, thereby appropriately suppressing the tilt of each pole 30. This concludes the description of the structure in which the rotation of the cam 40 retracts each pole 30 radially inward.

[0063] When the ratchet 10 is in the rotation region of the adjustment range shown in Fig. 11, the cam 40 is rotated counterclockwise as shown in Fig. 10 to return the pawls 30 to a 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 Fig. 12, the movement of the pawls 30 to mesh their external teeth 31 with the internal teeth 13A of the ratchet 10 is stopped midway even if the cam 40 is rotated counterclockwise as shown in the figure.

[0064] Specifically, when the cam 40 is rotated counterclockwise in the free zone, the protrusions 34 projecting axially from each of the pawls 30 come into contact with the inner peripheral surfaces of the free zone protrusions 12 of the ratchet 10. The free zone protrusions 12 are configured to be divided into three regions curved with different radii of curvature corresponding to the positions where the protrusions 34 of each of the pawls 30 are formed. Therefore, when the ratchet 10 is in the adjustment range shown in FIG. 10 , the free zone protrusions 12 do not come into contact with the protrusions 34 of each of the pawls 30 even if the cam 40 is rotated counterclockwise in the illustration.

[0065] As shown in Fig. 12, the protrusions 34 of each pole 30 come into contact with the free zone protrusions 12, preventing each pole 30 from engaging with the ratchet 10. As shown in Fig. 6, each pole 30 is configured by half-blanking so that its radially inner region protrudes axially inward relative to its outer region.

[0066] Each pole 30 is arranged so that its radially outer region is aligned with the radially outer side of the cam 40. Each pole 30 is also arranged so that its radially inner half-blanked region covers the cam 40 from the axially inner side. The protrusion 34 of each pole 30 is half-blanked so as to protrude from the radially outer region of each pole 30 in the axially inner side.

[0067] The retraction holes 33 of each pole 30 are formed in the radially inner region that covers the cam 40 of each pole 30. Retraction pins 43 that protrude axially from the cam 40 are set to fit into these retraction holes 33.

[0068] With this configuration, each pole 30 is pressed from the inside in the radial direction by the cam 40 as the cam 40 rotates counterclockwise as shown in the figure. Also, as the cam 40 rotates clockwise as shown in the figure, each pole 30 is pulled inward in the radial direction as each retraction pin 43 abuts against the hole inner surface 33A of each retraction hole 33.

[0069] Cam 40 As shown in Figures 4 and 5, the cam 40 is made of a single metal plate member cut into a substantially circular disk shape. The cam 40 has a shape with substantially the same plate thickness as each of the poles 30. As shown in Figure 6, the 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 cam 40 is positioned so that the poles 30 are lined up at its radially outer positions.

[0070] An elongated through-hole 41 that penetrates in the axial direction is formed in the center (position on the central axis C) of the cam 40. An operation pin 5A (see FIG. 1) having a corresponding fitting shape is inserted axially into this through-hole 41 and assembled so as to be integral with the cam 40 in the rotational direction.

[0071] The operating pin 5A is connected to the operating shaft (not shown) of the reclining lever 5 described above in Fig. 1. The operating pin 5A is rotated by pulling up the reclining lever 5, and rotates the cam 40 shown in Fig. 6 together with the operating pin 5A. This operation rotates the cam 40 clockwise as shown in Fig. 11, and each of the poles 30 is pulled inward in the radial direction.

[0072] As shown in Figure 1, the operating pin 5A is integrally connected to an operating pin 5A inserted into the recliner 4 on the inside (left) side of the vehicle via a connecting rod 5B. As a result, when the reclining lever 5 is pulled up, the cams 40 of both recliners 4 are simultaneously released.

[0073] 3, a pin-shaped hook portion 44 is formed on the axial outer surface of the cam 40. The inner end portion 51 of the lock spring 50 described above is hooked onto this hook portion 44. As a result, a biasing force is always applied to the cam 40 from the lock spring 50 in the lock rotation direction (counterclockwise in FIG. 10).

[0074] 10, when the cam 40 is rotated counterclockwise, which is the rotation direction of the lock, a plurality of protruding pressing portions 42 protruding from the outer circumferential surface of the cam 40 press the corresponding pawls 30 from the radially inner side. As a result, the cam 40 pushes the corresponding pawls 30 radially outward as the rotation progresses, causing them to mesh with the internal teeth 13A of the ratchet 10.

[0075] 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 in the axial direction into a stepped cylindrical shape. As a result, the outer ring 60 is formed into a shape having a flange portion 61 that extends in the radial direction like a hollow disk, and a step portion 62 that extends in the axial direction from the outer periphery of the flange portion 61 into a stepped cylindrical shape.

[0076] The outer ring 60 is attached across the outer peripheries of the ratchet 10 and guide 20 after they are assembled as follows: First, as shown in Figure 6, the lock spring 50, three pawls 30, and cam 40 are set in the guide 20. Next, as shown in Figure 8, the ratchet 10 is assembled to the guide 20.

[0077] Then, the outer ring 60 is set so as to cover the cylindrical portion 13 of the ratchet 10 and the cylindrical portion 22 of the guide 20 from the outer periphery side. Specifically, the flange portion 61 of the outer ring 60 is set so as to abut the cylindrical portion 13 of the ratchet 10 from the outside in the axial direction, and the ratchet 10 and the guide 20 are passed through the cylindrical portion of the outer ring 60.

[0078] As a result, the stepped portion 62 of the outer ring 60 is brought into contact with the cylindrical portion 22 of the guide 20 from the inside in the axial direction. Next, the cylindrical end of the stepped portion 62 that protrudes outward in the axial direction from the cylindrical portion 22 of the guide 20 is crimped so as to bend inward in the radial direction. This crimped portion is formed as a connecting portion 63 that is connected to the stepped portion 62 so as to sandwich the cylindrical portion 22 of the guide 20 in the axial direction.

[0079] As a result, the outer circumferential ring 60 is integrally joined to the cylindrical portion 22 of the guide 20. The flange portion 61 of the outer circumferential ring 60 presses the cylindrical portion 13 of the ratchet 10 against the outside in the axial direction. This allows the outer circumferential ring 60 to hold the ratchet 10 and the guide 20 so that they can rotate relative to each other and cannot come off in the axial direction.

[0080] To summarize the above, the recliner 4 according to this embodiment has the following configuration: Note that the reference numerals in parentheses below correspond to the respective components shown in the above embodiment.

[0081] That is, the seat reclining device (4) has a ratchet (10), a guide (20), a cam (40), and at least one pawl (30). The ratchet (10) and the guide (20) are connected to each other so that they can rotate about a central axis (C) of the reclining mechanism. The cam (40) is assembled to the guide (20) so that it can rotate about the central axis (C). The at least one pawl (30) is supported on both sides in the rotational direction by the guide (20), and is pushed outward in the radial direction by rotation of the cam (40) in one direction, thereby meshing with the ratchet (10) to lock the rotation.

[0082] The seat reclining device (4) further has an engagement portion (F) formed between the retraction member (40), which is either the cam (40) or a member integrated therewith, and the pole (30). The engagement portion (F) engages with the pole (30) so as to retract the pole (30) radially inward when the cam (40) rotates in the other direction. The engagement portion (F) causes the retraction member (40) to abut against the pole (30) from the radially outer side at two positions sandwiching the center of the rotation of the pole (30).

[0083] According to the above configuration, when the pole (30) is pulled inward by the rotation of the cam (40), the engaging portion (F) can prevent the pole (30) from tilting in the rotation direction. Therefore, regardless of the rotation direction in which a load is applied to the ratchet (10), tilting of the pole (30) in either direction during unlocking can be suppressed.

[0084] The engaging portion (F) has a retraction hole (33) recessed in the axial direction and formed in the pole (30), and two retraction pins (43) protruding in the axial direction so as to enter the retraction hole (33) from two positions in the rotation direction of the cam (40). The engaging portion (F) is configured so that, when the cam (40) rotates in the other direction, the two retraction pins (43) abut from the radial outside against two hole inner surfaces (33A) aligned in the rotation direction of the retraction hole (33).

[0085] The two hole inner peripheral surfaces (33A) are shaped to be rotationally symmetrical with each other about the central axis (C). According to the above configuration, the pole (30) can be pulled straight inward in the radial direction directly by the cam (40).

[0086] Furthermore, a plurality of poles (30) are provided in the rotational direction. Engagement portions (F) are provided between all of the poles (30) and the retractable member (40). This configuration can prevent all of the poles (30) from tilting in both directions when unlocking. Therefore, the operating load for unlocking can be appropriately reduced.

[0087] Other Embodiments Although one embodiment of the present invention has been described above, the present invention can be embodied in various forms in addition to the above embodiment.

[0088] 1. The seat reclining device of the present invention may be applied to vehicle seats as well as non-vehicle seats installed in various facilities such as sports facilities, theaters, concert halls, event venues, etc. Furthermore, the seat reclining device may be one that connects a seat back to a seat cushion so that the backrest angle can be adjusted, or one that connects a seat back to a base such as a bracket fixed to the vehicle body so that the backrest angle can be adjusted.

[0089] The seat reclining device may have a configuration in which the guide is connected to the seat back and the ratchet is connected to the seat cushion or the base. The seat reclining device may also be used to adjust the angle of the ottoman or armrest in addition to adjusting the angle of the seat back.

[0090] 2. At least one pole may be provided, but one, two, four or more poles may be provided. The arrangement of the poles in the rotational direction relative to the guide is not limited to being evenly spaced, and they may be arranged with a bias in the rotational direction as shown in JP 2015-029635 A.

[0091] Furthermore, the operation of retracting at least one pole radially inward by rotation of the cam may be performed using a release plate integrally assembled with the cam, as disclosed in documents such as JP 2015-227071 A. In this case, the release plate corresponds to the "retraction member" of the present invention, and an engagement portion is formed between the release plate and at least one pole. The engagement portion may be configured such that a pair of retraction pins protruding axially from at least one pole enter a retraction hole formed in the retraction member to retract the pole.

[0092] 3. The retraction hole formed in at least one pole may be an axially penetrating hole or may be an axially recessed hole into which a corresponding retraction pin can be inserted. When multiple poles are provided, the engagement portion does not necessarily have to be formed between all of the poles and the cam, as long as it is formed between at least one pole and the cam. By suppressing tilting of at least one pole, the operating load for unlocking can be reduced to a certain extent. [Explanation of symbols]

[0093] 1 sheet 2 seat backs 2F side frame 3 seat cushions 3F Reclining plate 4 Reclining seat 5 Reclining lever 5A operation pin 5B connecting rod 6 Return spring 10 Ratchet 11 Disc section 11A through hole 12 Free Zone Protrusion 13 Cylindrical part 13A Internal teeth 20 Guide 21 Disc 22 Cylindrical part 23 Guide Wall 24 Pole accommodation groove 25 Cam receiving groove 26 Spring receiving hole 30 Paul 31 Outer teeth 33 Inlet hole 33A Hole inner surface 34 Protrusion 40 Cam (retraction member) 41 Through hole 42 Pressing section 43 Retractable pin 44 Hook 50 Rock Spring 51 inner edge 52 outer edge 60 outer ring 61 Flange 62 Step 63 Joint C center axis F Engagement part

Claims

1. A seat reclining device, a ratchet and a guide connected to each other so as to be rotatable about a central axis of reclining; a cam mounted on the guide so as to be rotatable about the central axis; At least one pawl supported by the guide from both sides in the rotational direction, and pushed outward in the radial direction by the rotation of the cam in one direction, and meshed with the ratchet to lock the rotation; an engaging portion formed between the pole and a retracting member that is either the cam or a member integrated therewith, and that engages with the pole so as to retract the pole radially inward when the cam rotates in the other direction; A seat reclining device in which the engaging portion abuts the retractable member against the pole from the radially outer side at two positions sandwiching the center of the rotation direction of the pole.

2. The seat reclining device according to claim 1, the engaging portion has a retraction hole formed in the pole and recessed in the axial direction, and two retraction pins protruding in the axial direction so as to enter the retraction hole from two positions in the rotation direction of the cam, and the two retraction pins are configured to abut from the outside in the radial direction against two inner peripheral surfaces of holes aligned in the rotation direction of the retraction hole by the rotation of the cam in the other direction, The seat reclining device, wherein the two inner peripheral surfaces of the holes are shaped to be rotationally symmetrical with each other about the central axis.

3. The seat reclining device according to claim 1 or 2, A plurality of the poles are provided in the rotation direction, A seat reclining device, wherein the engagement portion is provided between all of the poles and the retractable members.

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