JP7633516B2 - Reclining device - Google Patents

Description

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 one another.

Conventionally, the reclining device disclosed in Patent Document 1 below is known as a reclining device that adjusts the tilt angle between a first member and a second member that tilt relative to one another. This reclining device is configured to switch between a locked state in which the external teeth of the lock gears mesh with the internal teeth of the gear plate and an unlocked state in which the meshing is released, depending on the state of contact between the cam that rotates in response to the operation of the reclining operation lever and the four lock gears.

In addition, a slidable movable guide is interposed between each of the lock gears and the fixed guides, and the width of each of these movable guides gradually narrows from the outer end to the inner end. The sliding surface of the movable guide on the lock gear side is parallel to the direction of movement of the lock gear, and the sliding surface on the fixed guide side is inclined relative to the sliding surface on the lock gear side. A spring is engaged with each of the movable guides, and the spring biases the movable guide inward toward the base plate. As a result, the movable guide is always wedged between the lock gear and the fixed guide, and the fixed guide, lock gear, and movable guide fit together, eliminating any gaps between the various components. This reliably eliminates any backlash in the front-to-rear direction of the seat back, enabling reliable locking and unlocking.

JP 2012-056397 A

However, a meshing state (hereinafter simply referred to as a fully meshed state) in which the external teeth of the lock gear that has moved in the locking direction along the guide surface provided on the base plate and the internal teeth of the gear plate mesh completely without misalignment exists for each gear tooth pitch. Therefore, if the relative angle between the gear plate and the lock gear deviates from the fully meshed state due to twisting of the seat frame, etc., the external teeth of the lock gear that has moved in the locking direction along the guide surface and the internal teeth of the gear plate mesh in an incompletely meshed state. For example, with a gear tooth pitch of 2°/tooth, if the gear plate deviates relatively from the fully meshed state by 0.5°, the external teeth of the lock gear and the internal teeth of the gear plate do not mesh sufficiently, resulting in insufficient meshing. When such insufficient meshing occurs, not only does the meshing portion, etc., become insufficient in strength, but it may also promote frame twisting, etc.

The present invention has been made to solve the above-mentioned problems, and its purpose is to provide a configuration that allows the external teeth of the lock gear and the internal teeth of the gear plate to properly mesh even if the relative angle between the gear plate and the lock gear is misaligned.

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 a tilt angle between 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 and having internal teeth (41);
a lock gear (61) assembled to the base plate so as to be slidable in a radial direction and having external teeth (61a) capable of meshing with the internal teeth;
a movable guide (63, 64) disposed between a gear side surface (61d, 61e) of the lock gear along a sliding direction and a guide surface (31a, 32a) provided on the base plate;
A cam (70) capable of controlling radial movement of the lock gear and biased in a locking direction to mesh the external teeth with the internal teeth;
a biasing member (82) that biases the movable guide in a direction pressing the movable guide against both the gear side surface and the guide surface;
Equipped with
The guide surface is formed to be concavely curved so that the distance between the guide surface and the gear side surface becomes closer toward the inside in the radial direction,
The movable guide is characterized in that one side surface (63a, 64a) that is pressed against the gear side surface is in face contact with the gear side surface, and the other side surface (63b, 64b) that is pressed against the guide surface is formed so as to be convexly curved.
The symbols in parentheses above indicate the corresponding relationship with the specific means described in the embodiments described later.

In the invention of claim 1, a movable guide is disposed between the gear side surface of the lock gear along the sliding direction and a guide surface provided on the base plate. The guide surface is formed with a concave curve so that the distance to the gear side surface decreases as it moves radially inward, and the movable guide is formed so that one side surface that is pressed against the gear side surface is in surface contact with the gear side surface, and the other side surface that is pressed against the guide surface is curved convexly.

As a result, when the external teeth of the lock gear, which has moved radially outward due to the force from the cam in the locking direction, mesh with the internal teeth of the gear plate, the other convexly curved side of the movable guide is guided by the convexly curved guide surface of the base plate. Therefore, when the gear plate and the lock gear mesh with each other in a state where the relative angle between them is shifted from the fully meshed state, the force in the locking direction shifts the contact position between the other side of the movable guide and the guide surface of the base plate along the curved shape, so that the movable guide and the lock gear are tilted relative to the gear plate to eliminate the shift from the fully meshed state. In other words, even if the relative angle between the gear plate and the lock gear is shifted, the lock gear is tilted to achieve the fully meshed state, so that the external teeth of the lock gear and the internal teeth of the gear plate can be properly meshed.

In the invention of claim 2, a pair of movable guides and guide surfaces are provided on the left and right sides of the lock gear, so the angle at which the movable guide and lock gear are tilted is large, allowing the external teeth of the lock gear to mesh more reliably with the internal teeth of the gear plate.

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. FIG. FIG. 3 is a cross-sectional view taken along a line X1-X1 shown in FIG. 2. 3 is a cross-sectional view taken along line X2-X2 of FIG. 2. FIG. 6(A) is an explanatory diagram illustrating the state of the lock gear and both movable guides just before meshing, and FIG. 6(B) is an explanatory diagram illustrating the state of the lock gear and both movable guides in an incomplete meshing state. FIG. 7(A) is an explanatory diagram illustrating a state in which the lock gear tilts from the state shown in FIG. 6(B) to a fully engaged state, and FIG. 7(B) is an enlarged view showing the area enclosed by the dashed double-dashed line in FIG. 7(A).

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of a reclining device according to the present invention will be described with reference to the 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.

The lower bracket 11a and the upper bracket 12a are fixed to the respective rotating parts of the round reclining unit 21, and are connected to each other so as to be capable of rotating relative to each other. This allows the tilt angle of the seat back 12 relative to the seat cushion 11 to be adjusted. 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".

A reclining operation lever 23 is attached to the center shaft 22 in the center of the round reclining unit 21. The round reclining unit 21, the center shaft 22, and the reclining operation lever 23 constitute the reclining device 20. When the reclining operation lever 23 is pulled upward, the reclining device 20 is unlocked and the tilt angle of the seat back 12 can be adjusted. Here, the range of angle A shown in FIG. 1 where the seat back 12 is tilted backward is the tilt adjustment range where the seat back 12 is locked at the angle position when the reclining operation lever 23 is released, and the range of angle B shown in FIG. 1 where the seat back 12 is tilted forward is the free rotation range corresponding to the lock-free state where the unlocked state continues even if the reclining operation lever 23 is released. As can be seen from FIG. 1, the seat back 12 can be rotated from a forward tilt position where it contacts the seat cushion 11 to a backward tilt position where it is flat against the seat cushion 11. The structure of such a reclining device 20 will be described below.

As shown in Figures 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, so that the base plate 30 and the gear plate 40 are held so as to be rotatable relative to each other and their relative movement in the axial direction is suppressed. For convenience, the center shaft 22 and reclining operation lever 23 are not shown in Figures 2 and 3, and in Figures 4 and 5, only the area near the internal teeth 41 of the gear plate 40 is shown, with the cover bracket 50 not shown.

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 contains a pair of lock gears 61, a pair of first movable guides 63, and a pair of second movable guides 64, a central cam 70, a pair of spring members 81 and 82, a substantially disk-shaped cam lever 90, and other locking and unlocking members. In the following description, the left side of Figure 2 is one axial side, and the right side is the other axial side.

The base plate 30 has multiple 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 engagement hole (not shown) in the lower bracket 11a.

As shown in FIG. 4, the base plate 30 has four guide protrusions 31, 32, 31, 32 formed on the other axial side for guiding both lock gears 61 in a radially slidable manner. The side surface of the guide protrusion 31 located on the lock gear 61 side (hereinafter also referred to as the first guide surface 31a) and the side surface of the guide protrusion 32 located on the lock gear 61 side (hereinafter also referred to as the second guide surface 32a) are formed to function as a pair of guide surfaces for guiding the lock gear 61 and the movable guides 63, 64. In particular, the first guide surface 31a and the second guide surface 32a are formed to be concavely curved so that the distance to the gear side surface of the lock gear 61 becomes closer as they move radially inward. The detailed shapes of the first guide surface 31a and the second guide surface 32a will be described later.

Two recesses 36 are formed on the other axial side of the base plate 30, facing each other via an insertion hole 35 through which the shaft portion (not shown) of the center shaft 22 passes. Both recesses 36 are for accommodating a spiral spring member 81, and an engagement piece 36a that engages one end of the spring member 81 is formed to extend from the bottom surface to the other axial side.

The gear plate 40 has internal teeth 41 formed around the entire inner circumferential surface. The gear plate 40 has multiple 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 engagement hole (not shown) in the upper bracket 12a.

In addition, two arc-shaped steps are arranged at 180° intervals on the inner peripheral surface of the gear plate 40, which are coaxial with the internal teeth 41. These arc-shaped steps are intended to achieve the above-mentioned lock-free state, and are formed so that the angular range in which the protrusion 61c (described later) of the lock gear 61 abuts from the inner peripheral side corresponds to the above-mentioned free rotation range.

As shown in Figures 3 and 4, the outer periphery of the lock gear 61 is formed with external teeth 61a that can mesh with the internal teeth 41 of the gear plate 40. The lock gear 61 is also provided with a protrusion 61b that protrudes toward the other axial side (gear plate side), and this protrusion 61b functions to control the radial movement of the lock gear 61 by being guided by a rotating cam lever 90 as described below. The lock gear 61 is also provided with a protrusion 61c on the outer side of the protrusion 61b, and this protrusion 61c is formed so that the internal teeth 41 and the external teeth 61a are kept disengaged by abutting against the arc-shaped step portion of the gear plate 40 from the inner periphery.

The lock gear 61 is sandwiched between the first guide surface 31a of the guide protrusion 31 and the second guide surface 32a of the guide protrusion 32, with the gear sides 61d, 61e, which are substantially planar along the sliding direction, in surface contact with both the movable guide 63 and the movable guide 64.

The first movable guides 63 are disposed between the lock gear 61 and the guide protrusion 31 with one side surface (hereinafter also referred to as side surface 63a) formed in a substantially flat shape in surface contact with the gear side surface 61d and the other side surface (hereinafter also referred to as convex side surface 63b) formed in a convex curve in a rounded contact (contact between a convex curved surface and a concave curved surface) with the first guide surface 31a. The convex side surface 63b is formed so that its curvature is about R16, which is smaller than the curvature of the first guide surface 31a (about R100 in this embodiment). The first movable guide 63 is formed with an engagement hole 63c for engaging one end of the spring member 82, and a protrusion 63d extending from a position inside the engagement hole 63c to the other axial side is formed.

The second movable guides 64 are disposed between the lock gear 61 and the guide protrusion 32, with one side surface (hereinafter also referred to as side surface 64a) formed in a substantially flat shape in surface contact with the gear side surface 61e, and the other side surface (hereinafter also referred to as convex side surface 64b) formed in a convex curve in a R-contact with the second guide surface 32a. The convex side surface 64b is formed so that its curvature is about R16, which is smaller than the curvature of the second guide surface 32a (in this embodiment, about R100). The second movable guide 64 is formed with an engagement hole 64c for engaging the other end of the spring member 82, and a protrusion 64d extending axially to the other side from a position inside the engagement hole 64c is formed.

In this embodiment, the first movable guide 63 is formed relative to the second movable guide 64 such that the radial length of the side surface 63a (the vertical length in FIG. 4) is longer than the radial length of the side surface 64a.

5, one end and the other end of the spring member 82 are engaged with the engagement hole 63c of the first movable guide 63 and the engagement hole 64c of the second movable guide 64, and the spring member 82 biases the first movable guide 63 and the second movable guide 64 inwardly of the base plate 30. This bias causes the first movable guides 63 to be pressed against the first guide surface 31a with the convex side surface 63b in surface contact with the gear side surface 61d at the side surface 63a, and the second movable guides 64 to be pressed against the second guide surface 32a with the convex side surface 64b in surface contact with the gear side surface 61e at the side surface 64a. Therefore, the first movable guides 63 are always wedged between the lock gear 61 and the guide protrusion 31, and the second movable guides 64 are always wedged between the lock gear 61 and the guide protrusion 32. This eliminates gaps between the components and eliminates backlash in the fore-aft direction of the seat back 12. The spring member 82 can be an example of a "biasing member."

Therefore, both lock gears 61 are guided by the first movable guide 63 and the second movable guide 64, which are biased as described above, so that the gear side surfaces 61d and 61e come into surface contact with the side surface 63a of the first movable guide 63 and the side surface 64a of the second movable guide 64, respectively, and are supported so as to be slidable in the radial direction.

A plate-shaped cam 70, in which a through hole 71 is formed for inserting the shaft portion of the center shaft 22, is rotatably arranged on the base plate 30. The cam 70 is formed so that the cam surfaces 72 contact the inner end faces 61f of both lock gears 61 from the radially inner side, respectively, and mesh the external teeth 61a of the lock gear 61 with the internal teeth 41 of the gear plate 40 when rotated to a predetermined state around the shaft portion that serves as the rotation axis. In addition, the cam 70 has two protrusions 73 formed on one axial side surface with which the other end side of the spring member 81 in the recess 36 engages, and two protrusions 74 formed on the other axial side surface with which the cam lever 90 engages.

As shown in FIG. 4, the cam 70 is strongly biased in the lock rotation direction (clockwise in FIG. 4 and FIG. 5) by engaging the other end side of the spring member 81 at the protrusion 73. As a result, the cam 70 abuts the inner end faces 61f of both lock gears 61 with the cam surface 72, and the biasing force in the lock rotation direction by both spring members 81 strongly biases both lock gears 61 radially outward.

The shaft portion of the center shaft 22 is inserted into the through hole 71 of the cam 70, and by rotating the center shaft 22, the cam 70 can be rotated in the unlock rotation direction (counterclockwise in Figures 4 and 5) against the biasing force of both spring members 81.

As shown in FIG. 5, the cam lever 90 is provided with a through hole 91 that fits onto both protrusions 74 of the cam 70, a pair of cam holes 92 and a pair of cam holes 93, and a pair of cam surfaces 94. The cam hole 92 is formed to move the lock gear 61 radially inward when unlocked by using the inserted protrusion 61b. The cam hole 93 is formed so that the other end side of the spring member 82 that engages with the engagement hole 64c of the second movable guide 64 and the protrusion 64d are inserted therethrough, and the inserted protrusion 64d is used to restrict the radially inward movement of the second movable guide 64 when unlocked. The cam surface 94 is formed so that the protrusion 63d is used to restrict the radially inward movement of the first movable guide 63 when unlocked.

The cam lever 90 is attached to the cam 70 with the through holes 91 and the protrusions 74 fitted together, the protrusion 61b inserted into the cam holes 92, and the protrusion 64d inserted into the cam holes 93.

As a result, when the cam lever 90 rotates together with the cam 70 in the unlock rotation direction, the inner periphery of the cam hole 92 abuts against the protrusions 61b of the lock gears 61. When the cam lever 90 rotates further in the unlock rotation direction, both protrusions 61b are biased radially inward by the inner periphery of each cam hole 92, and each lock gear 61 moves radially inward in unison.

The reclining device 20 thus constructed has both lock gears 61, movable guides 63, 64, cam 70, etc. arranged in cavity C and assembled together, and the side periphery of the base plate 30 and gear plate 40 is ring-crimped with the cover bracket 50 to be integrated. This allows the base plate 30 and gear plate 40 to be held so that they can rotate relative to each other, while preventing relative movement in the axial direction.

Then, the reclining operation lever 23 is attached to the center shaft 22, the shaft portion of which is inserted into the through hole 71 of the cam 70, to complete the reclining device 20 shown in FIG. 2. With the reclining device 20 thus configured, the seat cushion 11 and the seat back 12 are connected by the reclining device 20 so that they can tilt relative to each other by engaging each of the projections 30b of the base plate 30 with the engagement holes of the lower bracket 11a and each of the projections 40a of the gear plate 40 with the engagement holes of the upper bracket 12a.

Next, the unlocked and locked states of the reclining device 20 according to this embodiment configured as described above will be described below.

(Unlocked)
First, the unlocked state of the reclining device 20 will be described.
When an occupant unlocks the seat back 12 to adjust the inclination angle of the seat back 12, the occupant operates the reclining operation lever 23 to rotate the center shaft 22 in the unlock rotation direction. Then, the cam 70 rotates in the unlock rotation direction together with the center shaft 22 against the biasing forces of the two spring members 81.

When the cam 70 rotates in the unlock rotation direction, the cam surface 72 of the cam 70 is released from contact with the inner end faces 61f of both lock gears 61, and the urging force of the cam 70 that urges both lock gears 61 radially outward is released. This allows both lock gears 61 to move radially inward, and the meshing between the internal teeth 41 of the gear plate 40 and the external teeth 61a of both lock gears 61 becomes disengageable.

Then, as the cam lever 90 rotates together with the cam 70 in the unlock rotation direction, the inner edges of both cam holes 92 of the cam lever 90 come into contact with the protrusions 61b of both lock gears 61, actively moving both lock gears 61 radially inward and releasing the meshing between the internal teeth 41 and the external teeth 61a.

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

(Unlocked state)
Next, the unlocked state of the reclining device 20 will be described.
In the above-described unlocked state, when the seat back 12 is tilted forward, the base plate 30 and the gear plate 40 rotate relative to each other, and both lock gears 61 move to a position where the protrusion 61c can abut against the arc-shaped step portion of the gear plate 40. In this state, when the reclining operation lever 23 is loosened, the cam 70 rotates in the lock rotation direction due to the biasing force of both spring members 81, and the rotation of the cam 70 biases both lock gears 61 radially outward.

At this time, the projections 61c of both lock gears 61 abut against the arc-shaped step portions of the gear plate 40, so the internal teeth 41 and the external teeth 61a remain disengaged. Therefore, while the projections 61c abut against the arc-shaped step portions 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 Figure 1).

(Locked state)
Next, the locked state of the reclining device 20 will be described.
When the occupant has finished adjusting the reclining angle of the seat back 12 , the reclining operation lever 23 is loosened, and the cam 70 is rotated in the lock rotation direction by the biasing forces of both spring members 81 .

When the cam surface 72 of the rotating cam 70 comes into contact with the inner end surfaces 61f of both lock gears 61, both lock gears 61 are biased radially outward. This causes the external teeth 61a of both lock gears 61 to move radially outward so as to mesh with the internal teeth 41 of the gear plate 40. Then, when the external teeth 61a of both lock gears 61 mesh with the internal teeth 41 of the gear plate 40, the rotation of the gear plate 40 is restricted, and the reclining device 20 enters a locked state.

Next, the effect of improving the meshing state by the first movable guide 63, the second movable guide 64, and the first guide surface 31a and the second guide surface 32a will be described with reference to the drawings.
In the conventional configuration in which the lock gear is provided so as to be movable only in the radial direction relative to a guide surface provided on the base plate, if the relative angle between the gear plate and the lock gear deviates from a complete meshing state (a meshing state in which the external teeth of the lock gear moved in the locking direction and the internal teeth of the gear plate completely mesh without any misalignment) due to twisting of the seat frame, the external teeth of the lock gear moved in the locking direction along the guide surface will mesh with the internal teeth of the gear plate in an incomplete meshing state.

For example, as shown in FIG. 6(A), if the gear plate 40 is shifted by a certain angle (e.g., 0.5°) from the above-mentioned fully meshed state at a certain gear tooth pitch (e.g., 2°/tooth pitch), unless the lock gear 61 tilts, the external teeth 61a of the lock gear 61 and the internal teeth 41 of the gear plate 40 will not mesh sufficiently, resulting in insufficient meshing, as shown in FIG. 6(B). When such insufficient meshing occurs, not only will there be insufficient strength at the meshing parts, but there is also a risk of encouraging frame twisting, etc.

For this reason, in the reclining device 20 according to this embodiment, a first movable guide 63 is disposed between the gear side surface 61d of the lock gear 61 and a first guide surface 31a provided on the base plate 30, and a second movable guide 64 is disposed between the gear side surface 61e and the second guide surface 32a. The first guide surface 31a is formed with a concave curve so that the distance to the gear side surface 61d decreases as it moves radially inward, and the second guide surface 32a is formed with a concave curve so that the distance to the gear side surface 61e decreases as it moves radially inward. The first movable guide 63 is formed so that the side surface 63a that is pressed against the gear side surface 61d is in surface contact with the gear side surface 61d, and the convex side surface 63b that is pressed against the first guide surface 31a is curved in a convex shape, and the second movable guide 64 is formed so that the side surface 64a that is pressed against the gear side surface 61e is in surface contact with the gear side surface 61e, and the convex side surface 64b that is pressed against the second guide surface 32a is curved in a convex shape.

In particular, the concave curved shapes of the first guide surface 31a and the second guide surface 32a and the convex curved shapes of the convex side surface 63b and the convex side surface 64b are set so that the force acting on the first movable guide 63 via the first guide surface 31a and the gear side surface 61d by the biasing force of the spring member 82 engaging with the engagement hole 63c is approximately equal to the force acting on the second movable guide 64 via the second guide surface 32a and the gear side surface 61e by the biasing force of the spring member 82 engaging with the engagement hole 64c.

As a result, when the external teeth 61a of the lock gear 61, which has moved radially outward due to the force from the cam 70 in the locking direction, mesh with the internal teeth 41 of the gear plate 40, the first movable guide 63 and the second movable guide 64 are guided by the first guide surface 31a and the second guide surface 32a of the base plate 30 at the convex side surfaces 63b and 64b.

When the gear plate 40 and the lock gear 61 are engaged in a state where the relative angle between them is shifted from the fully engaged state (see FIG. 6B), the contact position between the convex side surface 63b of the first movable guide 63 and the first guide surface 31a and the contact position between the convex side surface 64b of the second movable guide 64 and the second guide surface 32a are shifted along their curved shapes by the force in the locking direction. As a result, as illustrated in FIG. 7A and FIG. 7B, the first movable guide 63, the second movable guide 64, and the lock gear 61 are tilted relative to the gear plate 40 so as to eliminate the shift from the fully engaged state. In other words, even if the relative angle between the gear plate 40 and the lock gear 61 is shifted, the lock gear 61 is tilted to achieve the fully engaged state, so that the external teeth 61a of the lock gear 61 and the internal teeth 41 of the gear plate 40 can be properly engaged.

In particular, in this embodiment, the movable guides 63, 64 and the guide surfaces 31a, 32a are provided in pairs on the left and right sides of the lock gear 61, so that the angle at which the movable guides 63, 64 and the lock gear 61 are tilted is large, and the external teeth 61a of the lock gear 61 and the internal teeth 41 of the gear plate 40 can be more reliably engaged.

[Other embodiments]
The present invention is not limited to the above-described embodiment, and may be embodied as follows, for example.
(1) The present invention is not limited to being applied to a reclining device 20 in which a pair of movable guides 63, 64 and concave guide surfaces 31a, 32a are provided on the left and right sides for one locking gear 61, but may also be applied to a reclining device in which a set of movable guides and concave guide surfaces are provided on either the left or right side for one locking gear.

(2) The present invention is not limited to application to a reclining device 20 that employs a pair of lock gears 61, but may also be applied to a reclining device that employs three or more lock gears.

(3) The present invention is not limited to being applied to a 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 this 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."

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 30... Base plate 31a... First guide surface (guide surface)
32a...Second guide surface (guide surface)
40: gear plate 41: internal teeth 61: lock gear 61a: external teeth 61d, 61e: gear side surface 63: first movable guide (movable guide)
63a...side surface (one side surface)
63b...convex side surface (other side surface)
64...Second movable guide (movable guide)
64a...Side (one side)
64b...convex side surface (other side surface)
70: Cam; 81: Spring member; 82: Spring member (urging member)
90…Cam lever

Claims (2)

A reclining device that adjusts a tilt angle between a first member and a second member that tilt relatively, comprising:
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 lock gear that is assembled to the base plate so as to be slidable in a radial direction and has external teeth that can mesh with the internal teeth;
a movable guide disposed between a gear side surface of the lock gear along a sliding direction and a guide surface provided on the base plate;
A cam capable of controlling radial movement of the lock gear and biased in a locking direction to cause the external teeth to mesh with the internal teeth;
a biasing member that biases the movable guide in a direction to press the movable guide against both the gear side surface and the guide surface;
Equipped with
The guide surface is formed to be concavely curved so that the distance between the guide surface and the gear side surface becomes closer toward the inside in the radial direction,
The reclining device is characterized in that the movable guide is formed so that one side surface that is pressed against the gear side surface is in surface contact with the gear side surface, and the other side surface that is pressed against the guide surface is convexly curved. The reclining device according to claim 1, characterized in that the movable guide and the guide surface are provided in a pair on the left and right sides of the lock gear.

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