Reclining device

Abstract

To provide a structure that can suppress deviation in the axial direction of an internal component arranged between a base plate and a gear plate.SOLUTION: In the gear plate 40 side of a first lock gear 61, there is provided a projection 61d that is used for controlling the radial movement of the first lock gear 61. This projection 61d has an axial height larger than the plate thickness of a cam lever 90, and is formed in a manner opposing through a prescribed gap Ga for the annular opposite side 43 of the gear plate 40 during the rotation. Also, in the cam lever 90, in a part opposing to the opposite side 43 during the rotation, there is formed a gap adjustment part 94 for the purpose of reducing a gap Gb in-between the opposite side 43.SELECTED DRAWING: Figure 9

Description

[Technical Field]

[0001] The present invention relates to a reclining device that adjusts the tilt angle between a first member and a second member that tilt relative to each other. [Background technology]

[0002] A conventional reclining device that adjusts the tilt angle between a first member and a second member that tilt relative to one another is the vehicle reclining device disclosed in Patent Document 1. This reclining device is configured to switch between a locked state in which each lock gear engages with a gear plate and an unlocked state in which the engagement is released, depending on the state of contact between a cam that rotates in response to operation of a reclining operation lever and four lock gears.

[0003] Additionally, a slidable movable guide is interposed between each lock gear and fixed guide. The width of each movable guide gradually narrows from its outer end to its inner end. The sliding surface of each movable guide, which faces the lock gear, is parallel to the direction of movement of the lock gear, while the sliding surface of each movable guide faces the fixed guide and is inclined relative to the sliding surface of the lock gear. Each movable guide is engaged with a spring, which biases the movable guide inward toward the base plate. This keeps the movable guide constantly wedged between the lock gear and fixed guide, ensuring that the fixed guide, lock gear, and movable guide fit tightly together, eliminating any gaps between the components. This reliably eliminates backlash in the seat back's fore-and-aft direction, enabling reliable locking and unlocking. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2012-056397 Summary of the Invention [Problem to be solved by the invention]

[0005] As described above, in a configuration in which internal parts such as a lock gear, movable guide, cam, and spring are disposed in a cavity (space) formed between a base plate and a gear plate, axial gaps are provided between some of the parts by design to prevent the internal parts from being pinched during assembly even if there is variation in the dimensions of the parts.

[0006] However, because of the gap described above, when an external force is applied, such as during a collision, the internal parts may shift axially, and depending on the amount of shift, for example, the contact area between the cam and the lock gear may become smaller during the unlocking operation, which could result in pressure loss or the like at the contact point.

[0007] The present invention has been made to solve the above-mentioned problems, and its purpose is to provide a configuration that can suppress axial misalignment of internal parts arranged between the base plate and the gear plate. [Means for solving the problem]

[0008] In order to achieve the above object, the invention of claim 1 described in the claims is as follows: A reclining device (20) for adjusting the tilt angle of a first member (11, 11a) and a second member (12, 12a) that tilt relatively, comprising: a base plate (30) attached to the first member; a gear plate (40) attached to the second member and assembled to be rotatable relative to the base plate, the gear plate having internal teeth (41); The base plate is assembled so as to be guided radially slidably by utilizing guide surfaces (33a, 33b) formed on the base plate, and has external teeth (61a) that can mesh with the internal teeth. a pair Lock gear (61) and a cam (70) that abuts against the lock gear from the radially inner side when rotating in a locking direction about a predetermined rotation axis (22), thereby causing the external teeth to mesh with the internal teeth; a biasing member (80) that biases the cam in a direction that causes the external teeth to mesh with the internal teeth; a thin-plate-shaped cam lever (90) assembled to the gear plate side of the cam, which moves the lock gear radially inward so as to release the meshing between the external teeth and the internal teeth when the cam rotates in the unlocking direction; Equipped with On the gear plate side of the lock gear, When the meshing between the external teeth and the internal teeth is released and the base plate and the gear plate rotate relative to each other, the inner circumferential side of the gear plate abuts against the arc-shaped step portion of the gear plate in order to maintain the unlocked state. A protrusion (61d) is provided to control the radial movement of the lock gear, The protrusion has an axial height greater than the plate thickness of the cam lever, and is formed to face the annular opposing side surface (43) of the gear plate with a predetermined gap (Ga) therebetween when the cam lever rotates. The cam lever has a shaft that faces the opposing side surface when rotated. outer edge The gap adjusting portions (94, 94a, 94b) are formed at the portions so as to reduce the gap (Gb) between the opposing side surfaces. The symbols in parentheses above indicate the correspondence with the specific means described in the embodiments to be described later. [Effects of the Invention]

[0009] In the invention of claim 1, the gear plate side of the lock gear is provided with: When the meshing between the external and internal teeth is released and the base plate and gear plate rotate relative to each other, the gear plate abuts against the arc-shaped step portion of the gear plate from the inner periphery to maintain the unlocked state. A protrusion is provided to control the radial movement of the lock gear, and the protrusion has an axial height greater than the thickness of the cam lever and is formed so as to face the annular opposing side surface of the gear plate with a predetermined gap therebetween when the cam lever rotates. outer edge A gap adjusting portion is formed at the portion so as to reduce the gap between the opposing side surface.

[0010] As a result, even if the cam lever is displaced in the axial direction due to the action of an external force such as during a collision, the gap adjuster will come into contact with the opposing annular side surface of the gear plate with only a slight displacement, so the amount of axial displacement of the cam lever can be suppressed without increasing the plate thickness of the cam lever compared to a case where the gap adjuster is not machined in the area opposing the opposing side surface. Furthermore, because the cam and lock gear are arranged on the base plate side of the cam lever whose amount of axial displacement is suppressed in this way, axial displacement of internal parts such as the cam lever, cam, and lock gear arranged between the base plate and the gear plate can be suppressed without adding a new axial biasing member.

[0011] As in the invention of claim 2, the gap adjusting portion may be formed of a plurality of protrusions protruding toward the opposing side surface.

[0012] As in the invention of claim 3, the gap adjusting portion may be configured by an arc-shaped restricting portion.

[0013] As in the invention of claim 4, the gap adjusting portion may be formed by a circular arc-shaped bent portion. [Brief explanation of the drawings]

[0014] [Figure 1] 1 is a side view showing an outline of the configuration of a vehicle seat on which a reclining device of the present invention is installed. [Figure 2] FIG. [Figure 3] FIG. [Figure 4] 3 is a cross-sectional view taken along a line X1-X1 shown in FIG. 2. [Figure 5] 3 is a cross-sectional view taken along a line X2-X2 shown in FIG. 2. [Figure 6] FIG. 2 is a plan view of the gear plate as seen from the base plate side. [Figure 7] FIG. [Figure 8] FIG. 8 is a plan view of the cam lever of FIG. 7. [Figure 9] Figure 9(A) is an enlarged cross-sectional view illustrating the axial gap between the annular opposing side surfaces of the gear plate and the protrusion of the lock gear, and Figure 9(B) is an enlarged cross-sectional view illustrating the axial gap between the annular opposing side surfaces of the gear plate and the gap adjustment portion of the cam lever. [Figure 10] FIG. 10 is a perspective view of a cam lever according to a first modified example. [Figure 11] FIG. 11 is a plan view of the cam lever of FIG. 10. [Figure 12] FIG. 10 is a perspective view of a cam lever according to a second modified example. [Figure 13] FIG. 13 is a plan view of the cam lever of FIG. 12. BEST MODE FOR CARRYING OUT THE INVENTION

[0015] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a reclining device according to the present invention will now be described with reference to the accompanying drawings. As shown in FIG. 1, a vehicle seat 10 equipped with a reclining device 20 of the present invention has a seat cushion 11 and a seat back 12 as its main components, with a seat bracket (lower bracket) 11a fixed to the seat cushion 11 and a seat back bracket (upper bracket) 12a fixed to the seat back 12.

[0016] The lower bracket 11a and the upper bracket 12a are respectively fixed to relatively rotating portions of the round reclining unit 21, and are thereby connected to each other so as to be able to rotate relative to each other. This makes it possible to adjust the tilt angle of the seat back 12 relative to the seat cushion 11. The seat cushion 11 and the lower bracket 11a can be an example of a "first member," and the seat back 12 and the upper bracket 12a can be an example of a "second member."

[0017] A reclining operation lever 23 is attached to a center shaft 22 in the center of the round reclining unit 21. The round reclining unit 21, center shaft 22, and reclining operation lever 23 constitute the reclining device 20. Pulling the reclining operation lever 23 upward unlocks the reclining device 20, allowing the tilt angle of the seatback 12 to be adjusted. The range of angle A shown in FIG. 1 when the seatback 12 is tilted backward is the tilt adjustment range in which the seatback 12 is locked in that angle position when the reclining operation lever 23 is released. The range of angle B shown in FIG. 1 when the seatback 12 is tilted forward is the free rotation range corresponding to the unlocked state in which the seatback 12 remains unlocked even when the reclining operation lever 23 is released. As can be seen from FIG. 1, the seatback 12 can be rotated from a forward-tilted position in which it contacts the seat cushion 11 to a backward-tilted position in which it is flat against the seat cushion 11. The structure of this reclining device 20 will be described below.

[0018] 2 and 3, the round reclining unit 21 is configured by overlapping a substantially disc-shaped base plate 30 with a substantially bowl-shaped gear plate 40 and assembling a cover bracket 50, thereby holding the base plate 30 and the gear plate 40 so that they can rotate relative to each other and restricting relative movement in the axial direction. For convenience, the center shaft 22 and the reclining operation lever 23 are not shown in FIGS. 2 and 3, and only the vicinity of the internal teeth 41 of the gear plate 40 is shown in FIGS. 4 and 5, with the cover bracket 50 not shown.

[0019] A cavity (space) C is formed between the base plate 30 and the gear plate 40. As shown in Figures 2 to 5, this cavity C is provided with a total of four lock gears, a pair of first lock gears 61 and a pair of second lock gears 62, a central cam 70, two biasing members 80, and a substantially disk-shaped cam lever 90, and other members for locking and unlocking. In Figure 2, the left side of the drawing is one axial side, and the right side of the drawing is the other axial side, and the following description will be given accordingly.

[0020] The base plate 30 has a plurality of protrusions 30b formed on one axial side surface (hereinafter also referred to as the mounting surface 30a), and is attached to the lower bracket 11a by engaging each of these protrusions 30b with an engaging hole (not shown) in the lower bracket 11a. Furthermore, as shown in FIGS. 3 and 4, the base plate 30 has four guide protrusions 31, 32, 31, 32 formed on the side surface on the other axial side (the gear plate 40 side) for radially guiding the lock gears 61, 62. In the following description, of the pair of guide surfaces for guiding the first lock gear 61, the guide surface of the guide protrusion 31 will be referred to as one first guide surface 33a, and the guide surface of the guide protrusion 32 will be referred to as the other first guide surface 33b, as shown in FIG. 4. Of the pair of guide surfaces for guiding the second lock gear 62, the guide surface of the guide protrusion 32 is designated as one second guide surface 34a, and the guide surface of the guide protrusion 31 is designated as the other second guide surface 34b.

[0021] The base plate 30 is formed with an insertion hole 35 through which the shaft portion (not shown) of the center shaft 22 is inserted. In addition, a circular recess 36 is provided on the other axial side surface of the base plate 30 at a position inside the guide protrusions 31, 32 so as to be coaxial with the insertion hole 35. As shown in FIG. 2, the recess 36 is formed so that one axial side of the cam 70 fits into the recess 36 to be able to rotate relatively. The depth of the recess 36 can be set to be equal to the allowable axial misalignment between the cam 70 and the lock gears 61, 62.

[0022] 6, internal teeth 41 are formed around the entire inner peripheral surface of the gear plate 40. The gear plate 40 has a plurality of protrusions 40a formed on its back surface (the surface on the other axial side), and is attached to the upper bracket 12a by engaging each of these protrusions 40a with an engaging hole (not shown) in the upper bracket 12a.

[0023] Additionally, two arcuate step portions 42 are arranged at 180° intervals on the inner peripheral surface of the gear plate 40 facing the base plate 30 and are formed coaxially with the internal teeth 41. The arcuate step portions 42 are intended to realize the above-mentioned lock-free state, and are formed so that the angular range in which a protrusion 61d (described later) of the first lock gear 61 abuts from the inner peripheral side corresponds to the above-mentioned free rotation range.

[0024] 3 and 4, external teeth 61a, 62a that can mesh with the internal teeth 41 of the gear plate 40 are formed on the outer peripheries of both first lock gears 61 and both second lock gears 62. Each lock gear 61, 62 is assembled so as to be guided radially slidably using guide surfaces 33a, 33b, 34a, 34b of the base plate 30. Specifically, both first lock gears 61 are guided by one first guide surface 33a of the guide protrusion 31 and a movable guide 37 (described later) that is guided by the other first guide surface 33b of the guide protrusion 32, and are supported so as to be slidable only in the radial direction. Furthermore, both second lock gears 62 are guided by one second guide surface 34a of the guide protrusion 32 and the other second guide surface 34b of the guide protrusion 31, and are supported so as to be slidable only in the radial direction.

[0025] Furthermore, each of the first lock gears 61 is provided with a protrusion 61b that protrudes as an engaging portion on the other axial side (the gear plate 40 side), and each of the second lock gears 62 is provided with a protrusion 62b that protrudes as an engaging portion on the other axial side. Both protrusions 61b and both protrusions 62b function to control the radial movement of each of the lock gears 61, 62 by being guided by a rotating cam lever 90, as will be described later.

[0026] Furthermore, protrusions 61d used to control the radial movement of the lock gears 61 are also provided on the other axial side (gear plate 40 side) of each of the first lock gears 61, outside the protrusions 61b. As shown in Fig. 9(A) , each of the protrusions 61d has an axial height greater than the thickness of the cam lever 90, and is formed so that when the protrusions 61d rotate, they face the annular opposing side surface 43 of the gear plate 40 across a predetermined gap Ga, and come into contact with the arc-shaped step portion 42 of the gear plate 40 from the inner circumferential side, thereby maintaining a state in which the internal teeth 41 and the external teeth 61a are disengaged.

[0027] The movable guide 37 is formed in a wedge shape so that its width gradually narrows from one end to the other end, and is slidably disposed between the first lock gear 61 and the other first guide surface 33b of the guide protrusion 32. Each movable guide 37 is formed with an engagement hole 37a for engaging a biasing member 80. By engaging the biasing member 80 with the engagement hole 37a, the biasing member 80 biases each movable guide 37 inward of the base plate 30. As a result, the movable guide 37 is always wedged between the first lock gear 61 and the other first guide surface 33b, and the first lock gear 61, the other first guide surface 33b, and the movable guide 37 are tightly fitted together (fitted together), eliminating any gap in the rotation direction between each component. This eliminates backlash in the front-rear direction of the seat back 12.

[0028] A plate-shaped cam 70, which has a through hole 71 formed therein for inserting the shaft portion of the center shaft 22, is rotatably disposed on the base plate 30, utilizing the recess 36. The cam 70 abuts against the inner end surfaces 61 c of both lock gears 61 and the inner end surfaces 62 c of both lock gears 62 from the radially inner side at cam surfaces 72, respectively, and is formed so that when the cam 70 rotates to a predetermined state about the shaft portions that serve as the rotation axis, the external teeth 61 a, 62 a of the lock gears 61, 62 mesh with the internal teeth 41 of the gear plate 40. Furthermore, the cam 70 has two engagement holes 73 with which the biasing member 80 engages and two cylindrical protrusions 74 that protrude to the other axial side, formed on the side surface facing the gear plate 40.

[0029] As shown in Fig. 5, the cam 70 is strongly urged in the locking direction (clockwise in Figs. 4 and 5) by engaging with each of the two urging members 80. As a result, the cam 70 abuts the inner end faces 61c, 62c of the locking gears 61, 62 at the cam surface 72, and the urging forces in the locking direction from the two urging members 80 strongly urge the locking gears 61, 62 radially outward.

[0030] The shaft portion of the center shaft 22 is inserted into the through hole 71 of the cam 70, and by rotating this center shaft 22, the cam 70 can be rotated in the unlocking direction (counterclockwise in Figures 4 and 5) against the biasing forces of both biasing members 80.

[0031] The biasing member 80 is formed as an elastically deformable wire spring, and is configured to have one end that engages with the engagement hole 73 of the cam 70, the other end that engages with the engagement hole 37a of the movable guide 37, and an elastically deformable, approximately arc-shaped connecting portion that connects the one end and the other end.

[0032] 7 and 8, the cam lever 90 is made by subjecting a thin steel plate (for example, SPFC590 material with a plate thickness of 1.0 mm) to plastic processing such as pressing, and is provided with through holes 91 that fit over both protrusions 74 of the cam 70, as well as two cam holes 92 and two cam holes 93. Both cam holes 92 are formed so that their inner peripheral edges urge the protrusions 61 b ​​of the first lock gear 61 radially inward when the cam lever 90 rotates in the unlocking direction. Both cam holes 93 are formed so that their inner peripheral edges urge the protrusions 62 b of the second lock gear 62 radially inward when the cam lever 90 rotates in the unlocking direction.

[0033] The cam lever 90 is also provided with a pair of gap adjusters 94 at its outer edge portion (the outer edge portion whose distance from the rotation axis is approximately the same as that of the protrusion 61d of the first lock gear 61) that faces the annular opposing side surface 43 of the gear plate 40 during rotation. As can be seen from FIG. 9(B), the gap adjusters 94 are formed with a tapered shape in which multiple protrusions protrude at a predetermined height toward the opposing side surface 43 from the outer edge portion, thereby reducing the gap Gb between the opposing side surface 43. The gap adjusters 94 allow the thickness (axial length) of the outer edge portion of the cam lever 90 to be greater than the thickness of other portions, i.e., the plate thickness. In particular, the tapered shape provided with multiple protrusions increases the section modulus, thereby improving the strength of the cam lever 90.

[0034] The cam lever 90 configured in this manner is assembled to the gear plate 40 side of the cam 70 with the through holes 91 and the protrusions 74 respectively fitted together, the protrusions 61b inserted into the cam holes 92 respectively, and the protrusions 62b inserted into the cam holes 93 respectively, as shown in Figure 5.

[0035] As a result, when the cam lever 90 rotates in the unlocking direction together with the cam 70, the inner peripheral edges of the cam holes 92 come into contact with the protrusions 61b of the first lock gear 61, and the inner peripheral edges of the cam holes 93 come into contact with the protrusions 62b of both second lock gears 62. When the cam lever 90 rotates further in the unlocking direction, the protrusions 61b and 62b are urged radially inward by the inner peripheral edges of the cam holes 92, 93, causing the lock gears 61, 62 to move radially inward in unison.

[0036] In the reclining device 20 configured in this manner, internal components such as the lock gears 61, 62, movable guide 37, cam 70, cam lever 90, and both biasing members 80 are disposed within cavity C and assembled together into a base plate 30 and gear plate 40, which are then ring-crimped around the periphery of the cover bracket 50 to form an integrated unit. This allows the base plate 30 and gear plate 40 to rotate relative to each other while restricting their relative axial movement.

[0037] 2 is assembled to the center shaft 22, the shaft of which is inserted into the through-hole 71 of the cam 70. In the reclining device 20 configured in this manner, the protrusions 30b of the base plate 30 are engaged with the engaging holes of the lower bracket 11a, and the protrusions 40a of the gear plate 40 are engaged with the engaging holes of the upper bracket 12a, whereby the seat cushion 11 and the seat back 12 are connected by the reclining device 20 so as to be able to tilt relative to each other.

[0038] Next, the unlocked state, the lock-free state, and the locked state of the reclining device 20 according to this embodiment configured as described above will be described below.

[0039] (Unlocked) First, the unlocked state of the reclining device 20 will be described. When an occupant unlocks the seat back 12 to adjust its tilt angle, the occupant operates the reclining operation lever 23 to rotate the center shaft 22 in the unlocking direction. This causes the cam 70 to rotate together with the center shaft 22 in the unlocking direction against the biasing forces of both biasing members 80.

[0040] When the cam 70 rotates in the unlocking direction, the cam surface 72 of the cam 70 is released from contact with the inner end faces 61c, 62c of each of the lock gears 61, 62, and the biasing force of the cam 70 that biases each of the lock gears 61, 62 radially outward is released. This allows each of the lock gears 61, 62 to move radially inward, and the meshing between the internal teeth 41 of the gear plate 40 and the external teeth 61a, 62a of each of the lock gears 61, 62 becomes disengageable.

[0041] Then, as the cam lever 90 rotates in the unlocking direction together with the cam 70, the inner peripheral edges of the cam holes 92, 93 of the cam lever 90 come into contact with the protrusions 61b, 62b of the lock gears 61, 62, actively moving the lock gears 61, 62 radially inward, thereby releasing the meshing between the internal teeth 41 and the external teeth 61a, 62a.

[0042] As described above, when the meshing between the internal teeth 41 and the external teeth 61a, 62a is released, the gear plate 40 becomes free to rotate, and the round reclining unit 21 enters an unlocked state. When the round reclining unit 21 enters an unlocked state, the reclining device 20 enters an unlocked state, and when the seat back 12 is tilted backward, the tilt angle of the seat back 12 becomes freely adjustable (see angle A in FIG. 1).

[0043] (Unlocked state) Next, the unlocked state of the reclining device 20 will be described. In the unlocked state described above, when the seat back 12 is tilted forward, the base plate 30 and the gear plate 40 rotate relative to each other, and both first lock gears 61 move to positions where the protrusion 61d can abut against the arc-shaped step portion 42 of the gear plate 40. When the reclining operation lever 23 is loosened in this state, the cam 70 rotates in the locking direction due to the biasing forces of both biasing members 80, and this rotation of the cam 70 biases each of the lock gears 61, 62 radially outward.

[0044] At this time, the protrusions 61d of both first lock gears 61 abut against the arc-shaped step portions 42 of the gear plate 40, so the internal teeth 41 and the external teeth 61a, 62a remain disengaged from each other. Therefore, while the protrusions 61d abut against the arc-shaped step portions 42 of the gear plate 40, the unlocked state is maintained even if the seat back 12 is tilted forward so that the base plate 30 and the gear plate 40 rotate relative to each other (see angle B in FIG. 1).

[0045] (locked state) Next, the locked state of the reclining device 20 will be described. When the occupant has finished adjusting the tilt angle of the seat back 12, the reclining operation lever 23 is loosened, and the cam 70 is rotated in the locking direction by the biasing forces of both biasing members 80.

[0046] The cam surfaces 72 of the rotating cam 70 come into contact with the inner end surfaces 61c, 62c of the lock gears 61, 62, respectively, thereby urging the lock gears 61, 62 radially outward. As a result, the external teeth 61a, 62a of the lock gears 61, 62 move radially outward so as to mesh with the internal teeth 41 of the gear plate 40. Then, as the external teeth 61a, 62a of the lock gears 61, 62 mesh with the internal teeth 41 of the gear plate 40, the rotation of the gear plate 40 is restricted, and the recliner 20 enters a locked state.

[0047] Next, the effect of the gap adjusting portion 94 of the cam lever 90 will be described with reference to FIG. Since the reclining device 20 is incorporated into the vehicle seat 10 so that its axial direction is approximately horizontal, when the reclining device 20 repeatedly transitions between the locked state, unlocked state, and unlocked state as described above, an axial force acts on each internal part in the cavity C. Furthermore, when an external force is applied during a collision or the like, an axial force also acts on each internal part.

[0048] In the reclining device 20 according to this embodiment, a protrusion 61d is provided on the gear plate 40 side of the first lock gear 61, and is used to control the radial movement of the first lock gear 61. As shown in Fig. 9(A), this protrusion 61d has an axial height greater than the plate thickness of the cam lever 90, and is formed so as to face the annular opposing side surface 43 of the gear plate 40 with a predetermined gap Ga therebetween when the protrusion 61d rotates. As shown in Fig. 9(B), the cam lever 90 is formed with a gap adjustment portion 94 at a portion that faces the opposing side surface 43 when the cam lever 90 rotates, so as to reduce the gap Gb between the opposing side surface 43.

[0049] As a result, even if the cam lever 90 is displaced in the axial direction due to the action of an external force such as during a collision, the gap adjustment portion 94 will come into contact with the annular opposing side surface 43 of the gear plate 40 with only a slight displacement. Therefore, the amount of axial displacement of the cam lever 90 can be suppressed without increasing the plate thickness of the cam lever 90, compared to a case where the gap adjustment portion 94 is not machined in the portion opposing the opposing side surface 43. Furthermore, since the cam 70 and the lock gears 61, 62 are disposed on the base plate 30 side of the cam lever 90 with the amount of axial displacement suppressed in this manner, axial displacement of internal parts such as the cam lever 90, cam 70, and the lock gears 61, 62 disposed between the base plate 30 and the gear plate 40 can be suppressed without adding a new axial biasing member.

[0050] [Other embodiments] The present invention is not limited to the above-described embodiments, and may be embodied as follows, for example. (1) The cam lever capable of suppressing axial misalignment of internal components is not limited to the cam lever 90 having the above-described gap adjuster 94. Cam levers having gap adjusters of other shapes may also be used. Specifically, for example, as in a first modified example illustrated in FIGS. 10 and 11 , a cam lever 90a having a gap adjuster 94a formed by an arc-shaped tapered portion that integrates the respective convex portions of the gap adjuster 94 may be used. By employing such an arc-shaped tapered portion, the thickness (axial length) of the outer edge portion can be easily adjusted by the gap adjuster 94a. Furthermore, as in a second modified example illustrated in FIGS. 12 and 13 , a cam lever 90b having a gap adjuster 94b formed by an arc-shaped bent portion that bends the end of the outer edge portion toward the gear plate 40 may be used. By employing such an arc-shaped bent portion, a gap adjuster that is easily strengthened against external forces from the gear plate 40 can be realized.

[0051] (2) The present invention is not limited to being applied to the reclining device 20 in which the base plate 30 is attached to the lower bracket 11a and the gear plate 40 is attached to the upper bracket 12a, but may also be applied to a reclining device in which the base plate is attached to the upper bracket 12a and the gear plate is attached to the lower bracket 11a. In such a configuration, the upper bracket 12a and the seat back 12 may correspond to the "first member," and the lower bracket 11a and the seat cushion 11 may correspond to the "second member." [Explanation of symbols]

[0052] 10...Vehicle seat 11...Seat cushion (first member) 11a...Lower bracket (first member) 12...Seat back (second member) 12a...Upper bracket (second member) 20...Reclining device 22...Center shaft (rotating shaft) 30...Base plate 33a, 33b...Guide surface 40...Gear plate 41...Inner teeth 43...Opposite side 61...1st lock gear 61a…external teeth 61d…Protrusion 62...Second lock gear 70…Cam 80... Urging member 90...Cam lever 94, 94a, 94b...Gap adjustment section Ga, Gb...gap

Claims

1. A reclining device that adjusts the tilt angle of a first member and a second member that tilt relatively, a base plate attached to the first member; a gear plate attached to the second member and assembled to be rotatable relative to the base plate, the gear plate having internal teeth; a pair of lock gears assembled to be guided radially slidably using guide surfaces formed on the base plate, the lock gears having external teeth meshable with the internal teeth; a cam that abuts against the lock gear from the inside in the radial direction when the cam rotates in a lock direction about a predetermined rotation axis, thereby causing the external teeth to mesh with the internal teeth; a biasing member that biases the cam in a direction that causes the external teeth to mesh with the internal teeth; a thin-plate-shaped cam lever that is assembled to the gear plate side of the cam and moves the lock gear radially inward so as to release the meshing between the external teeth and the internal teeth when the cam rotates in the unlocking direction; Equipped with a projection is provided on the gear plate side of the lock gear, the projection abutting against the arc-shaped step portion of the gear plate from the inner peripheral side to maintain an unlocked state when the meshing between the external teeth and the internal teeth is released and the base plate and the gear plate rotate relative to each other; and the protrusion has an axial height greater than a plate thickness of the cam lever, and is formed to face the annular opposing side surface of the gear plate with a predetermined gap therebetween when the cam lever rotates; The cam lever has a gap adjustment portion formed on its outer edge that faces the opposing side surface when the cam lever rotates, so as to reduce the gap between the opposing side surface and the cam lever.

2. The reclining device according to claim 1 , wherein the gap adjustment portion is formed by a plurality of protrusions protruding toward the opposing side surface.

3. 2. The reclining device according to claim 1, wherein the gap adjustment portion is formed by an arc-shaped narrowing portion.

4. The reclining device according to claim 1, wherein the gap adjustment portion is formed by an arc-shaped bent portion.

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