Clutch unit

Abstract

To enable an output shaft to rotate with high responsiveness when a lever is operated while enhancing rotation restriction of the output shaft when the lever is not operated.SOLUTION: A clutch unit 1 includes: an input side clutch 10 configured to control transmission and blockage of torque input by operation of a lever; an output side clutch 20 which restricts rotation of an output shaft 2 to be in a lock state where reverse input torque input to the output shaft 2 is blocked when the lever is not operated; and a lock mechanism 30 which restricts the rotation of the output shaft 2 at a position different from that of the output shaft 20 in an axial direction. The lock mechanism 30 restricts the rotation of the output shaft 2 by engagement between external teeth 31b of a first lock element 31, which integrally rotates with the output shaft 2, and internal teeth 32a of a second lock element 32 where rotation around an axis X of the output shaft 2 is restricted. Further, the lock mechanism releases the engagement state between the external teeth 31b and the internal teeth 32a by a second gear 32 being moved in the axial direction through operation of the lever. A tooth width L2 of the internal teeth 32a of the second lock element 32 is made smaller than a tooth width L1 of the external teeth 31b of the first lock element 31.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a clutch unit. [Background technology]

[0002] For example, Patent Document 1 listed below describes a clutch unit that is incorporated into a seat lifter that adjusts the seat height of an automobile seat, and that includes an input side clutch that controls the transmission and interruption of torque input by lever operation (rotation of the lever), an output side clutch consisting of a reverse input interruption clutch, and an output shaft onto which the input side and output side clutches are fitted, and in which torque input from the input side clutch to the output side clutch releases the locked state (reverse input interruption state) of the output side clutch, causing the output shaft to rotate around its axis.

[0003] More specifically, in the output clutch of the above clutch unit, when there is no torque input to the input clutch by lever operation, the rollers as engagement elements arranged in the wedge gap between the outer peripheral surface of the inner ring that rotates integrally with the output shaft and the inner peripheral surface of the outer ring whose rotation is restricted are engaged with both the inner ring and the outer ring (engaged in the circumferential direction with both the inner ring and the outer ring), resulting in a locked state in which the relative rotation of the inner ring and the outer ring, i.e., the rotation of the output shaft, is restricted. In this locked state, the reverse input torque input to the output shaft is not transmitted to the input clutch because the rotation of the output shaft is restricted. On the other hand, when torque is input from the input clutch to the output clutch by lever operation, the rollers are pushed outward of the wedge gap, resulting in an unlocked state in which the rotation of the inner ring relative to the outer ring is permitted. In the unlocked state, the torque input from the input clutch is transmitted to the output shaft via the inner ring, causing the output shaft to rotate. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2017-109698 A Summary of the Invention [Problem to be solved by the invention]

[0005] As described above, the locked state of the output clutch of the clutch unit is achieved by the roller disposed in the wedge gap between the inner and outer rings engaging with the inner and outer rings. However, there is a possibility that a slight slippage may occur between the roller and the inner and / or outer rings, causing the output shaft to rotate unintentionally. If such a slight slippage occurs in the driver's seat lifter, the seat height of the driver's seat will gradually drop, making it impossible to maintain an appropriate driving position. Therefore, it is necessary to strengthen the restriction on the rotation of the output shaft when the operating lever is not being operated. On the other hand, when adjusting the seat height, it is desired that the output shaft rotates with good responsiveness in response to the rotation of the operating lever.

[0006] Therefore, the present invention aims to provide a clutch unit that includes an input side clutch that controls the transmission and interruption of torque input by lever operation, and an output side clutch that is released from a locked state that restricts the rotation of the output shaft as torque is input to the input side clutch, thereby enabling the torque to be transmitted to the output shaft, thereby strengthening the restriction on the rotation of the output shaft when the lever is not operated, while enabling the output shaft to rotate with good responsiveness when the lever is operated. [Means for solving the problem]

[0007] The present invention, which has been devised to achieve the above object, an input clutch that controls transmission and interruption of torque input by lever operation; an output side clutch that is in a locked state when the lever is not operated to restrict the output shaft from rotating about its axis and cut off reverse input torque input to the output shaft, and a locking mechanism that restricts the rotation of the output shaft at an axial position different from that of the output side clutch, The lock mechanism is a clutch unit in which external teeth of a first locking element, which rotates integrally with the output shaft, mesh with internal teeth of a second locking element, the rotation of which about the axis of the output shaft is restricted, thereby restricting rotation of the output shaft, and in which the meshed state between the external teeth and the internal teeth is released by axial movement of the second locking element in response to lever operation, The second locking element has a feature that the width of the internal teeth is made smaller than the width of the external teeth of the first locking element.

[0008] In the clutch unit having the above configuration, a locking mechanism is additionally provided that restricts rotation of the output shaft at an axial position different from that of the output clutch when there is no lever operation (or torque input to the input clutch associated with the lever operation). This strengthens the restriction on rotation of the output shaft when the lever is not being operated, effectively reducing the possibility of the output clutch being unintentionally released from its locked state.

[0009] The lock mechanism can be configured such that the rotation of the output shaft is restricted by meshing (engaging in the circumferential direction of the output shaft) between the external teeth of the first lock element, which rotates integrally with the output shaft, and the internal teeth of the second lock element, whose rotation around the axis of the output shaft is restricted, and the meshed state of the external teeth and the internal teeth is released by the axial movement of the second lock element in response to the lever operation. In this case, if the tooth width (axial length) of the internal teeth of the second lock element, which moves in the axial direction in response to the lever operation, is made smaller than the tooth width of the external teeth of the first lock element, which does not move in the axial direction, the relative axial movement amount of the external teeth and the internal teeth required to release the meshed state of the external teeth and the internal teeth can be reduced. This reduces the amount of operation of the operating lever required to release the meshed state of the first lock element and the second lock element of the lock mechanism, and thus the locked state of the output side clutch, and therefore allows the output shaft to rotate with good responsiveness when the lever is operated. The first locking element may be, for example, an external gear having a plurality of teeth (external teeth) formed at equal intervals in the circumferential direction on its outer peripheral surface, and the second locking element may be, for example, an internal gear having a plurality of teeth (internal teeth) formed at equal intervals in the circumferential direction on its inner peripheral surface that can mesh with the external teeth; however, each locking element may be something other than the above-mentioned gears as long as it has teeth that can mesh with the mating locking element.

[0010] In the above configuration, the external teeth can be formed by punching (into a predetermined shape) the metal plate that is the base material of the first locking element, and the internal teeth can be formed by punching the metal plate that is the base material of the second locking element into a predetermined shape. This makes it possible to suppress an increase in cost of the clutch unit that additionally includes a locking mechanism that restricts the rotation of the output shaft by meshing the locking elements with each other. In this case, it is preferable that the first locking element and the second locking element are arranged so that the ends of the punching end side of the external teeth and the internal teeth are located on the same plane when the lever is not operated. This makes it possible to ensure an engagement allowance between the external teeth and the internal teeth, thereby appropriately strengthening the restriction on the rotation of the output shaft.

[0011] The first locking element can have an integral cylindrical fixing portion that is fixed to the outer circumferential surface of the output shaft, and this fixing portion is not in contact with any member other than the first locking element in the axial direction. This allows for freedom in selecting the position at which the first locking element is fixed to the output shaft, thereby improving the ease of assembly of the locking mechanism and, ultimately, the clutch unit.

[0012] In the above configuration, the output side clutch that constitutes the clutch unit can be, for example, one that includes a stationary member whose rotation around the central axis of the output shaft is restricted, and a roller disposed in a wedge gap formed between a plurality of cam surfaces provided on the output shaft and the inner surface of the stationary member, and that is locked when the roller engages with the output shaft and the stationary member in the rotational direction of the output shaft. Effect of the Invention

[0013] From the above, according to the present invention, in a clutch unit equipped with an input side clutch that controls the transmission and cut-off of torque input by lever operation, and an output side clutch consisting of a reverse input cut-off clutch that transmits input torque from the input side clutch to the output shaft, it is possible to strengthen rotation restriction of the output shaft when the lever is not operated, while enabling the output shaft to rotate with good responsiveness when the lever is operated. [Brief description of the drawings]

[0014] [Figure 1] FIG. 1 is a schematic vertical cross-sectional view of a clutch unit according to an embodiment of the present invention, showing a state where an operating lever is in a neutral position (where no lever operation is performed). [Diagram 2] FIG. 2 is a cross-sectional view taken along the line A in FIG. [Diagram 3] FIG. 2 is a cross-sectional view taken along the line B in FIG. [Figure 4] 2 is a cross-sectional view of the clutch unit taken along the line A in FIG. 1 when a lever is operated. [Diagram 5] 2 is a cross-sectional view of the clutch unit taken along the line B in FIG. 1 when a lever is operated. [Figure 6]FIG. 2 is an exploded perspective view of a portion of the clutch unit shown in FIG. [Figure 7] 1A and 1B are plan and side views of a locking mechanism in a locked position. [Figure 8] 1A and 1B are plan and side views of a locking mechanism in an unlocked position. [Figure 9] FIG. 4 is a schematic vertical cross-sectional view of the locking mechanism when the lever is operated. [Figure 10] FIG. 2 is a perspective view conceptually showing a cross-sectional state of a metal plate that has been punched. [Figure 11] FIG. 2(a) is an enlarged view of a main portion of FIG. 1, and FIG. 2(b) is an enlarged view of a main portion of a clutch unit that does not employ the configuration of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] Hereinafter, an embodiment of the present invention will be described with reference to Figs.

[0016] FIG. 1 is a schematic vertical cross-sectional view of a clutch unit 1 according to an embodiment of the present invention, in which an operating lever is in a neutral position (the operating lever is not operated). The clutch unit 1 is used, for example, by being incorporated into a seat lifter for adjusting the height of a seat surface of an automobile seat, and includes an output shaft 2 rotatably provided around an axis X, a housing 3, an operating lever 4, an input clutch 10, an output clutch 20, and a mechanical lock mechanism 30. In the following description, the terms "axial direction," "radial direction," and "circumferential direction" used to indicate directionality are respectively a direction parallel to the axis X of the output shaft 2, a radial direction of a circle centered on the axis X, and a circumferential direction of a circle centered on the axis X. In the following description, "rotation" refers to rotation around the axis X of the output shaft 2, unless otherwise specified.

[0017] The output shaft 2 includes a small diameter portion 2a having a cylindrical outer peripheral surface with a constant diameter, a spline portion 2b on which a spline (male spline) is formed, a large diameter portion 2c having a cylindrical outer peripheral surface with a larger diameter than the small diameter portion 2a, and a gear portion 2d on which a gear is formed. The small diameter portion 2a, the spline portion 2b, the large diameter portion 2c, and the gear portion 2d are arranged in this order from one axial side (the right side of the paper in FIG. 1, hereinafter also referred to as the input side) to the other axial side (the left side of the paper in FIG. 1, hereinafter also referred to as the output side). The input side end of the output shaft 2 in this embodiment is provided with a gear fixing portion 2e having a cylindrical outer peripheral surface with a smaller diameter (the smallest diameter of the output shaft 2) than the small diameter portion 2a.

[0018] The housing 3 is integrally formed with a stepped cylindrical portion having a small diameter cylindrical portion 3a fitted to the outer periphery of the small diameter portion 2a of the output shaft 2, a medium diameter cylindrical portion 3b accommodating the input clutch 10 on its inner periphery, and a large diameter cylindrical portion 3c accommodating the output clutch 20 on its inner periphery, and an attachment flange 3d (see FIG. 2, etc.) provided on the opening edge of the large diameter cylindrical portion 3c. The attachment flange 3d is provided with bolt holes through which bolt members are inserted when the housing 3 (clutch unit 1) is bolted to an attachment target such as an external frame. In addition, a disk-shaped portion of the housing 3 connecting the small diameter cylindrical portion 3a and the medium diameter cylindrical portion 3b is provided with a plurality of (three in this case, see FIG. 2) pillar portions 3e that protrude to the output side and are disposed in the annular space of the input clutch 10 at equal intervals in the circumferential direction. The pillar portions 3e divide the annular space into arc-shaped spaces and define the circumferential movement limit of the engagement element of the input clutch 10.

[0019] The input clutch 10 and the operating lever 4 will be described in detail with reference to Figures 1, 2, 4, 6, etc. The input clutch 10 controls the transmission and interruption of torque input by, for example, rotating the operating lever 4 disposed on the side of the seat. The input clutch 10 includes an inner ring 11 as an input rotating member, a lever mounting bracket 12, an outer ring 13 as an output rotating member, and a plurality of engaging elements and elastic members disposed between the inner ring 11 and the outer ring 13. The engaging elements and elastic members in the illustrated example are rollers 14 and coil springs 15, respectively, but other known engaging elements and elastic members may also be used. The inner ring 11 and the outer ring 13 are rotatably fitted to the outer periphery of the small diameter portion 2a of the output shaft 2.

[0020] The operating lever 4 has a lever body 5 and an operating plate 6. The lever body 5 has, integrally, a bottomed cylindrical housing portion 5A that houses the input clutch 10 and the lock mechanism 30, and a grip portion 5B that is gripped by an operator (such as a driver of a car).

[0021] As shown in Fig. 6, the operation plate 6 is a disk-shaped member having a non-circular central hole 6a, and is rotatably supported with respect to the small diameter cylindrical portion 3a of the housing 3 via a cylindrical support bush 7 or the like inserted into the central hole 6a so as to be unable to rotate relative to the housing. The operation plate 6 further has a lever attachment portion 6b attached to the inner peripheral wall surface of the accommodation portion 5A of the lever main body 5, and a plurality of holes 6c (three in the illustrated example) provided at equal intervals in the circumferential direction radially outside the central hole 6a. The holes 6c are formed in the shape of elongated holes extending in the circumferential direction.

[0022] The inner ring 11 is an annular member rotatably fitted onto the outer periphery of the small diameter portion 2a of the output shaft 2. This inner ring 11 has a convex portion 11a that protrudes towards the input side, and by fitting this convex portion 11a into a concave portion 12a provided in the lever mounting bracket 12, the inner ring 11 and the lever mounting bracket 12 can rotate together.

[0023] The lever mounting bracket 12 is provided with a plurality of (three in this example) engaging claws 12b protruding toward the input side at equal intervals in the circumferential direction, and each engaging claw 12b is inserted into a corresponding hole 6c (see FIG. 6) of the operation plate 6. When the operation lever 4 in the neutral position is rotated, the engaging claws 12b move along the longitudinal direction (circumferential direction) of the hole 6c and are then inserted into the hole 6c so as to come into contact with the peripheral end of the hole 6c. Therefore, even if the operation lever 4 in the neutral position is rotated, the lever mounting bracket 12 and the inner ring 11 connected thereto do not rotate together with the operation lever 4 until the operation lever 4 rotates a predetermined amount (until the rotation restriction of the output shaft 2 by the lock mechanism 30 is released by the operation lever 4 rotating a predetermined amount; details will be described later).

[0024] 2, the outer peripheral surface of the inner ring 11 is composed of a plurality of arc portions 11b having a curvature center at the axis X of the output shaft 2 and a plurality of wedge portions 11c protruding radially outward from the arc portions 11b, and in this embodiment, three arc portions 11b and three wedge portions 11c are provided alternately in the circumferential direction. The inner ring 11 is fitted to the outer periphery of the small diameter portion 2a of the output shaft 2 in a phase-matched state so that the tops of the wedge portions 11c face the column portions 3e of the housing 3 in the radial direction when there is no torque input by lever operation.

[0025] The outer ring 13 is rotatably fitted onto the outer periphery of the small diameter shaft portion 2a of the output shaft 2 on the output side of the inner ring 11. The outer ring 13 integrally includes a large diameter cylindrical portion 13a that houses the inner ring 11 and the like on its inner periphery, a small diameter cylindrical portion 13b that is disposed adjacent to the output side of the inner ring 11, and a disk-shaped connecting portion 13c that connects the output side end of the large diameter cylindrical portion 13a and the input side end of the small diameter cylindrical portion 13b.

[0026] An annular space is defined between the outer peripheral surface of the inner ring 11 and the inner peripheral surface of the large-diameter cylindrical portion 13a of the outer ring 13 facing the inner peripheral surface, and this annular space is divided into three arc-shaped spaces 16 by three pillar portions 3e provided on the housing 3. A pair of rollers 14 (14A, 14B) spaced apart in the circumferential direction and a coil spring 15 interposed between the pair of rollers 14 in a circumferentially compressed and deformed state are incorporated in each arc-shaped space 16. The arc-shaped space 16 has an equal-width portion 16a having a constant radial width formed by the arc portion 11b on the outer peripheral surface of the inner ring, and a wedge-shaped portion 16b formed by the wedge portion 11c on the outer peripheral surface of the inner ring and whose radial width gradually decreases toward the outside in the circumferential direction of the arc-shaped space 16. When the operating lever 4 is not rotated and no torque is input to the inner ring 11 (FIG. 2), the wedge-shaped portions 16b are provided on both circumferential sides of the equal-width portion 16a.

[0027] When the operating lever 4 is in the neutral position and no torque is input to the inner ring 11, the pair of rollers 14 are pushed into the wedge-shaped portion 16b of the arc-shaped space 16 by the elastic restoring force of the coil spring 15 and are engaged with both the inner ring 11 and the outer ring 13 (engaged with both the inner ring 11 and the outer ring 13 in the circumferential direction), as shown in Fig. 2. This restricts the relative rotation between the inner ring 11 and the outer ring 13.

[0028] On the other hand, for example, as shown in FIG. 4, when the torque T for rotating the inner ring 11 counterclockwise is input to the inner ring 11 by rotating the operating lever 4 in one direction at the neutral position, the wedge portion 11c of the inner ring 11 abuts against the roller 14 (14B) disposed adjacently on the front side in the rotation direction and presses the roller 14B in the circumferential direction. Accordingly, the roller 14B moves counterclockwise in the arc-shaped space 16 while compressing and deforming the coil spring 15, while the roller 14A is restricted in its circumferential movement by the column portion 3e of the housing 3. The roller 14B, which is directly subjected to the pressing force of the inner ring 11, moves counterclockwise in the arc-shaped space 16 while being pressed into the wedge portion 16b of the arc-shaped space 16, i.e., while being engaged with both the inner ring 11 and the outer ring 13 and restricting the relative rotation between them. Therefore, when the inner ring 11 rotates counterclockwise, the outer ring 13 also rotates counterclockwise together with the inner ring 11.

[0029] When the inner ring 11 rotates clockwise after rotating counterclockwise by a predetermined amount (torque input to rotate the inner ring 11 clockwise), the roller 14B leaves the wedge-shaped portion 16b of the arc-shaped space 16, and the engagement between the roller 14B and the inner ring 11 and the outer ring 13 is released, so that only the inner ring 11 rotates clockwise among the inner ring 11 and the outer ring 13 (the inner ring 11 rotates freely relative to the outer ring 13). In addition, the roller 14B receives an elastic restoring force accumulated in the coil spring 15 and moves clockwise in the arc-shaped space 16 to follow the rotation of the inner ring 11. When the inner ring 11 rotates clockwise by a predetermined amount, the input side clutch 10 returns to the initial state shown in FIG. 2.

[0030] When the operating lever 4, which is in the neutral position, is rotated in the other direction to input torque to the inner ring 11 to rotate the inner ring 11 clockwise, the wedge portion 11c of the inner ring 11 presses the roller 14A, which is adjacently arranged on the front side in the rotational direction, in the circumferential direction. As a result, the outer ring 13 rotates clockwise together with the inner ring 11 in the same manner as described above. In this case, when a torque is input to rotate the inner ring 11 counterclockwise, the input clutch 10 returns to the initial state.

[0031] Next, the output clutch 20 will be described mainly with reference to Fig. 1, Fig. 3, and Fig. 5 to Fig. 6. The output clutch 20 is a reverse input cutoff clutch that transmits torque input from the input clutch 10 to the output shaft 2, while cutting off reverse input torque input to the output shaft 2 without transmitting it to the input clutch 10. The output clutch 20, which is the reverse input cutoff clutch, includes an unlocking member 21 that rotates upon receiving torque input from the input clutch 10 (the outer ring 13 that is the output side rotating member), an inner ring 22 that rotates upon receiving torque of the input clutch 10 input via the unlocking member 21, an outer ring 23 that constitutes a stationary member whose rotation is restricted, a plurality of engaging elements and elastic members arranged between the inner ring 22 and the outer ring 23, and a friction ring 27. The engaging elements and elastic members in the illustrated example are rollers 24 and coil springs 25, respectively.

[0032] The unlocking member 21 is a disk-shaped member fitted to the outer periphery of the small diameter cylindrical portion 13b of the outer ring 13 of the input clutch 10 so as to be rotatable together with the outer ring 13, and constitutes an input side rotating member of the output clutch 20. The unlocking member 21 is provided with a hole 21a penetrating it in the axial direction, and a claw portion 21b is provided at the outer diameter end thereof, protruding to the output side and disposed radially outside the inner ring 22 (within the annular space 26 defined between the inner ring 22 and the outer ring 23). In this embodiment, as shown in Figs. 3 and 5, six holes 21a and claw portions 21b are provided at equal intervals in the circumferential direction. The hole 21a is formed in the shape of an elongated hole extending in the circumferential direction.

[0033] The inner ring 22 is disposed adjacent to the output side of the unlocking member 21 and is spline-fitted to the spline portion 2b of the output shaft 2. Therefore, the inner ring 22 is rotatable integrally with the output shaft 2 and constitutes the output-side rotating member of the output-side clutch 20. The inner ring 22 is provided with six convex portions 22a that protrude toward the input side and are spaced at equal intervals in the circumferential direction. Each of the convex portions 22a is inserted into an elongated hole portion 21a provided in the unlocking member 21. When the operating lever 4 is not rotated and no torque is input from the input-side clutch 10 to the unlocking member 21, the convex portion 22a of the inner ring 22 is located in the circumferential center of the hole portion 21a (see FIG. 3).

[0034] The outer ring 23 is fixed to the inner peripheral surface of the large diameter cylindrical portion 3c of the housing 3, and integrally includes a large diameter cylindrical portion 23a that houses the inner ring 22 on its inner circumference, a small diameter cylindrical portion 23b that is disposed adjacent to the output side of the inner ring 22, and a disk-shaped connecting portion 23c that connects the output side end of the large diameter cylindrical portion 23a and the input side end of the small diameter cylindrical portion 23b. A friction ring 27 made of a resin material and formed into a cylindrical shape is fixed to the inner circumference of the small diameter cylindrical portion 23b, and the inner peripheral surface of the friction ring 27 is pressed against the large diameter portion 2c of the output shaft 2. This provides rotational resistance to the output shaft 2, making it possible to prevent the output shaft 2 from rotating excessively when the operating lever 4 is rotated.

[0035] The annular space defined between the inner peripheral surface of the large-diameter cylindrical portion 23a of the outer ring 23 and the outer peripheral surface of the inner ring 22 is divided into six arc-shaped spaces 26 by six claws 21b of the unlocking member 21 that are arranged at equal circumferential intervals within the annular space. In each arc-shaped space 26, a pair of rollers 24 (24A, 24B) arranged at an interval in the circumferential direction and a coil spring 25 interposed between the pair of rollers 24 in a circumferentially compressed and deformed state are incorporated.

[0036] The arc-shaped space 26 is formed in a wedge shape with a radial width gradually decreasing from the circumferential center toward both circumferential ends. The arc-shaped space 26 is formed by forming the inner circumferential surface of the large diameter cylindrical portion 23a of the outer ring 23, which is the stationary side, into a cylindrical surface with a constant diameter, while forming the outer circumferential surface of the inner ring 22, which is the rotating side, into a non-circular cross section. Here, the outer circumferential surface of the inner ring 22 is formed into a non-circular cross section by continuously arranging six wedge-shaped portions 22b protruding radially outward in the circumferential direction, and the wedge-shaped arc-shaped space 26 is formed between two wedge-shaped portions 22b adjacent in the circumferential direction. The radial width of the arc-shaped space 26 at the circumferential center is larger than the diameter of the roller 24 by a predetermined amount, and the radial width of the arc-shaped space 26 at both circumferential ends is smaller than the diameter of the roller 24 by a predetermined amount.

[0037] For this reason, when the operating lever 4 is not rotated and no torque is input from the input clutch 10 to the lock release member 21, both of the pair of rollers 24 arranged in the arc-shaped space 26 are engaged with both the inner ring 22 and the outer ring 23 by the elastic restoring force of the coil spring 25. This maintains a locked state in which the relative rotation of the inner ring 22 with respect to the outer ring 23, and further the rotation of the output shaft 2, is restricted. In this locked state, even if a reverse input torque is input to the output shaft 2, the reverse input torque is not transmitted to the input clutch 10.

[0038] On the other hand, as shown in Fig. 5, for example, when the operating lever 4 is rotated in one direction to input a torque T to the unlocking member 21 via the input clutch 10 to rotate the unlocking member 21 counterclockwise, the claw portion 21b of the unlocking member 21 moves counterclockwise in the annular space (arc-shaped space 26) between the inner ring 22 and the outer ring 23. As a result, each claw portion 21b comes into contact with the roller 24 (roller 24B in Fig. 5) adjacently disposed on the front side in the rotation (movement) direction, and presses the roller 24B in the circumferential direction. When the roller 24B is pressed in the circumferential direction, the coil spring 25 is compressed and deformed in the circumferential direction, and the roller 24B is released from the position in the arc-shaped space 26 where it is engaged with both the inner ring 22 and the outer ring 23, and the engagement state (lock state) between the roller 24B and the inner ring 22 and the outer ring 23 is released. Even if a counterclockwise torque T is input to the lock release member 21, the roller 24A does not engage with the inner ring 22 and the outer ring 23 and rotates freely.

[0039] Furthermore, when the unlocking member 21 rotates counterclockwise, the convex portion 22a of the inner ring 22 inserted into the hole portion 21a of the unlocking member 21 abuts against the peripheral end of the hole portion 21a, as shown in Fig. 5. This allows the unlocking member 21 and the inner ring 22, as well as the output shaft 2 spline-fitted with the inner ring 22, to rotate counterclockwise as one body. Therefore, when the unlocking member 21 further rotates counterclockwise, the roller 24 and the coil spring 25 between the inner and outer rings 22 and 23 move circumferentially counterclockwise, and the inner ring 22 and the rotating shaft 2 rotate counterclockwise. As a result, a counterclockwise torque is output from the rotating shaft 2.

[0040] When torque is input to rotate the unlocking member 21 clockwise after the unlocking member 21 (as well as the inner ring 22 and the output shaft 2) has rotated counterclockwise a predetermined amount, the roller 24B receives a pressure force caused by the release of the elastic restoring force accumulated in the coil spring 25, moves clockwise within the arc-shaped space 26, and engages with both the inner ring 22 and the outer ring 23 in the circumferential direction at the peripheral end of the arc-shaped space 26. This causes the output clutch 20 to return to the locked state shown in FIG. 3 in which the reverse input torque can be blocked.

[0041] Next, the lock mechanism 30 will be described mainly with reference to Fig. 1 and Fig. 6 to Fig. 9. The lock mechanism 30 is disposed on the input side of the input clutch 10, and restricts the rotation of the output shaft 2 when the operating lever 4 is not operated (when the operating lever 4 is in the neutral position). The lock mechanism 30 includes a first gear 31 as a first locking element provided so as to be rotatable together with the output shaft 2, a second gear 32 as a second locking element whose rotation is restricted, a gear bracket 34, an elastic member 35, and an unlocking member 36.

[0042] The first gear 31 has a generally L-shaped cross section, integrally including a cylindrical portion 31c fixed to the output shaft 2 (the gear fixing portion 2e of the cylindrical portion 31c) and an annular portion 31a extending from the output end of the cylindrical portion 31c to the outer diameter side. As shown in Figs. 6 to 8, a plurality of external teeth 31b are formed at equal intervals in the circumferential direction on the outer diameter end (outer peripheral surface) of the annular portion 31a. The first gear 31 of this embodiment is fixed to the output shaft 2 so as to be rotatable integrally with the output shaft 2 by press-fitting the cylindrical portion 31c into the outer peripheral surface of the gear fixing portion 2e of the output shaft 2. As shown in an enlarged view in Fig. 9, the cylindrical portion 31c of the first gear 31 is not in contact with a stepped surface (the input side end surface of the small diameter portion 2a) of the output shaft 2 adjacent thereto in the axial direction, and the output side end surface of the cylindrical portion 31c faces the stepped surface of the output shaft 2 via an axial gap. In addition, the annular portion 31b is not in contact with the support bush 7 adjacent thereto in the axial direction, and the output side end face of the annular portion 31b faces the input side end face of the support bush 7 via an axial gap. This allows for freedom in selecting the position when fixing the first gear 31 to the output shaft 2, thereby improving the ease of assembly of the lock mechanism 30.

[0043] The first gear 31 is a punched part obtained by punching a metal plate of a predetermined thickness into a predetermined shape with a die set in a press device, and the external teeth 31b are formed during the punching process. That is, the first gear 31 is obtained by, for example, performing a drawing process on the center of a metal plate to obtain an intermediate product having a cylindrical portion 31c (and annular portion 31a), and then punching the outer diameter end of the annular portion 31a of this intermediate product into a shape corresponding to the external teeth 31b.

[0044] As shown in Figs. 6 to 8, the second gear 32 is a disk-shaped member disposed on the outer diameter side of the first gear 31, and a plurality of protrusions (internal teeth) 32a that can mesh (engage in the circumferential direction) with the external teeth 31b of the first gear 31 are formed at equal intervals in the circumferential direction at the inner diameter end. This second gear 32 is a punched part obtained by punching a metal plate of a predetermined thickness into a predetermined shape with a die set in a press device, similar to the first gear 31, and the internal teeth 32a are formed during the punching process. The thickness (axial dimension) of the second gear 32 is smaller than the thickness of the annular portion 31a of the first gear 31. Therefore, as shown in Fig. 11(a), the tooth width (axial dimension) L2 of the internal teeth 32a is smaller than the tooth width L1 of the external teeth 31b.

[0045] The gear bracket 34 is a stepped cylindrical member having a small diameter cylindrical portion 34a that is fitted to the outer periphery of the support bush 7, and the second gear 32 is fixed to a flange portion 34b provided at the input side end of the gear bracket 34. As shown in FIG. 6, the small diameter cylindrical portion 34a has a plurality (three) of notches 34c that are equally spaced in the circumferential direction, and the outer circumferential surface of the flange portion 34b has a plurality (three) of protruding pieces 34d that protrude radially outwardly that are equally spaced in the circumferential direction. The protruding portion 7a that is provided on the outer circumferential surface of the support bush 7 so as to protrude to the outer diameter side is fitted into the notches 34c of the gear bracket 34 via a small gap. As a result, the gear bracket 34 (and the second gear 32 fixed thereto) is supported by the support bush 7 in a state in which rotation is restricted and the gear bracket 34 (and the second gear 32 fixed thereto) is supported by the support bush 7 in a state in which it can move in the axial direction.

[0046] The elastic member 35 is interposed between the annular portion 31a of the first gear 31 and the gear bracket 34 in an axially compressed state, and constantly biases the gear bracket 34 (the second gear 32 fixed thereto) toward the output side. As this elastic member 35, a wave washer as shown in Fig. 6, or a compression coil spring, etc., can be used.

[0047] The unlocking member 36 is a cylindrical member that houses the gear bracket 34 on its inner periphery, and is fitted and fixed in the central hole 6a of the operation plate 6 so as to be rotatable together with the operation plate 6. The unlocking member 36 has three recesses 36a that can individually house the three protruding pieces 34d provided on the flange portion 34b of the gear bracket 34, and each recess 36a is defined between protruding portions 36b provided on both sides in the circumferential direction. The recesses 36a and the protruding portions 36b are connected via an inclined surface that forms an angle with respect to an axis-parallel plane that is parallel to the axis center X (see the side view shown in FIG. 7).

[0048] 1 and 7, when the operating lever 4 is not rotated and is in the neutral position, the protruding piece 34d of the gear bracket 34 is housed in the recess 36a of the lock release member 36. At this time, in the lock mechanism 30, the external teeth 31b of the first gear 31, which is rotatable together with the output shaft 2, mesh with the internal teeth 32a of the second gear 32, whose rotation is restricted. This restricts the rotation of the output shaft 2.

[0049] Next, when the operating lever 4, which was in the neutral position, is rotated by a predetermined amount, the unlocking member 36, which is fixed to the operating plate 6 of the operating lever 4 so as to be rotatable together with the operating plate 6, also rotates. On the other hand, since the rotation of the gear bracket 34 is restricted, when the unlocking member 36 rotates, the protruding piece 34d of the gear bracket 34 housed in the recess 36a of the unlocking member 36 rides up onto the input side end face of the protruding part 36b adjacent to the circumferential outer side of the recess 36a, as shown in FIG. 8. Accordingly, the second gear 32 (the gear bracket 34 to which the second gear 32 is fixed) moves overall to the input side while compressing and deforming the elastic member 35 interposed between the gear bracket 34 and the first gear 31 in the axial direction, and the second gear 32 (the internal teeth 32a) is positioned on the input side relative to the first gear 31 (the external teeth 31b), as shown in FIG. 9. As a result, the meshed state of the first gear 31 and the second gear 32, i.e., the restriction on the rotation of the output shaft 2 by the lock mechanism 30, is released.

[0050] Furthermore, when a rotation operation is performed to return the operating lever 4 to the neutral position, the various parts of the locking mechanism 30 operate in the reverse order to the above-mentioned order, causing the external teeth 31b of the first gear 31 and the internal teeth 32a of the second gear 32 to mesh again, thereby restricting the rotation of the output shaft 2.

[0051] The individual operating modes of the input clutch 10, the output clutch 20, and the lock mechanism 30 that constitute the clutch unit 1 of this embodiment have been described above. An example of the overall operating mode of the clutch unit 1 will now be briefly described.

[0052] For example, when the operating lever 4, which was in the neutral position, is rotated counterclockwise, first, torque is input to the unlocking member 36 constituting the locking mechanism 30. As a result, the second gear 32 of the locking mechanism 30 moves axially toward the output side, and the meshed state between the external teeth 31b of the first gear 31, which rotates integrally with the output shaft 2, and the internal teeth 32a of the second gear 32, whose rotation is restricted, is released (see FIG. 9). As a result, the rotation restriction of the output shaft 2 by the locking mechanism 30 is released, and the output shaft 2 becomes rotatable.

[0053] When the operating lever 4 is further rotated counterclockwise, as shown in FIG. 4, a torque T is input to the inner ring 11 of the input clutch 10 to rotate the inner ring 11 counterclockwise. The wedge portion 11c of the inner ring 11 to which the torque T is input abuts against the roller 14 (14B) disposed adjacently on the front side in the rotation direction, and presses the roller 14B in the circumferential direction. As a result, the roller 14B moves counterclockwise in the arc-shaped space 16 while compressing and deforming the coil spring 15. The roller 14B, which is directly subjected to the pressing force of the inner ring 11, moves counterclockwise in the arc-shaped space 16 while being pressed into the wedge portion 16b of the arc-shaped space 16, that is, while being engaged with both the inner ring 11 and the outer ring 13 and restricting the relative rotation between them, so that the outer ring 13, which is the output side rotating member of the input clutch 10, also rotates counterclockwise together with the inner ring 11.

[0054] As described above, when the outer ring 13, which is the output side rotating member of the input clutch 10, rotates counterclockwise, as shown in FIG. 5, a torque T that rotates the unlocking member 21, which is the input side rotating member of the output clutch 20, counterclockwise is input. Accordingly, the claw portion 21b of the unlocking member 21 arranged in the annular space (arc-shaped space 26) between the inner ring 22 and the outer ring 23 moves counterclockwise and abuts against the roller 24 (roller 24B in FIG. 5) arranged adjacently on the front side in the moving direction, and presses the roller 24B in the circumferential direction. This releases the circumferential engagement state between the roller 24B and the inner ring 22 and the outer ring 23, that is, the locked state in which the transmission of the reverse input torque input to the output shaft 2 to the input clutch 10 is interrupted. Of the pair of rollers 24 (24A, 24B), the roller 24A rotates idly without engaging with the inner ring 22 and the outer ring 23 even when the counterclockwise torque T is input to the unlocking member 21.

[0055] Furthermore, when counterclockwise torque T is input to the unlocking member 21, the protrusion 22a of the inner ring 22 inserted into the hole 21a of the unlocking member 21 abuts against the circumferential end of the hole 21a. As a result, the inner ring 22, which is the output-side rotating member of the output-side clutch 20, and the output shaft 2 spline-fitted with the inner ring 22 rotate counterclockwise as one unit in response to the counterclockwise torque T input to the unlocking member 21.

[0056] As described above, in the clutch unit 1 of this embodiment, when there is no torque input to the input clutch 10 due to lever operation, the lock mechanism 30 is additionally provided to restrict rotation of the output shaft 2 at an axial position different from the output clutch 20. This makes it possible to strengthen the restriction on rotation of the output shaft 2 when the operating lever 4 is not being operated, effectively reducing the possibility that the locked state of the output clutch 20 will be unintentionally released and the output shaft 2 will rotate.

[0057] In the lock mechanism 30 of this embodiment, the external teeth 31b of the first gear 31, which rotates integrally with the output shaft 2, mesh with the internal teeth 32a of the second gear 32, whose rotation is restricted, thereby restricting the rotation of the output shaft 2, and the second gear 32 moves to the input side in response to a lever operation, thereby releasing the meshed state between the external teeth 31b and the internal teeth 32a. At this time, the tooth width L2 of the internal teeth 32a of the second gear 32, which moves in the axial direction in response to the lever operation, is made smaller than the tooth width L1 of the external teeth 31b of the first gear 31, whose axial movement is restricted, so that the relative axial movement amount of both gears 31, 32 (the axial movement amount of the second gear 32) required to release the meshed state between the external teeth 31b and the internal teeth 32a can be reduced. This makes it possible to reduce the amount of rotation of the operating lever 4 required to release the meshed state of the first gear 31 and the second gear 32 that constitute the locking mechanism 30, and therefore the locked state of the output side clutch 20, and allows the output shaft 2 to rotate with good responsiveness when the lever is operated.

[0058] In this embodiment, both the first gear 31 having the external teeth 31b and the second gear having the inner surface 32a are formed by pressing a metal plate, and both the external teeth 31b and the internal teeth 32a are formed by stamping the metal plate. This makes it possible to suppress the manufacturing costs of both gears 31, 32, and thus the increase in the cost of the clutch unit 1 in which the lock mechanism 30 is additionally provided.

[0059] Incidentally, when a metal plate is punched from its front side to its back side with a die, as shown in FIG. 10, sagging Ma, sheared surfaces Mb, and even fractured surfaces (not shown) are formed in order on the punched surface of the metal plate M from the front side (the side where processing starts) to the back side (the side where processing ends). The sagging Ma is an R-shaped smooth surface formed by pulling the surface of the metal plate M with a press die, the sheared surface Mb is a smooth surface on which streaks in the plate thickness direction are visible, and the fractured surface is a rough surface with a larger surface roughness (poor surface properties) than the sheared surface Mb. Here, in consideration of the cost, it is not realistic to perform a finishing process on both gears 31 and 32 to remove the sagging Ma that appears on the outer peripheral surface of the annular portion 31a of the first gear 31 on which the external teeth 31b are formed during punching, and the sagging Ma that appears on the inner peripheral surface of the second gear 32 on which the internal teeth 32a are formed. Therefore, as shown in Figures 9 and 11(a), the outer peripheral surface of the annular portion 31a of the first gear 31 on which the external teeth 31b are formed, and the inner peripheral surface of the second gear 32 on which the internal teeth 32a are formed are surfaces on which a sag Ma is provided at one end of the metal plate in the thickness direction.

[0060] In this case, as shown in FIG. 11(a), the first gear 31 and the second gear 32 are adjusted in the axial position so that the ends of the punching end side of the external teeth 31b and the internal teeth 32a, that is, the ends opposite to the side where the sag Ma is formed, are located on the same plane when there is no lever operation (the operation lever 4 is located in the neutral position). In this case, the meshing allowance ε of the external teeth 31b and the internal teeth 32a in the tooth width direction can be made equal to the tooth width L2 of the internal teeth 32a. On the other hand, for example, as shown in FIG. 11(b), when the both gears 31 and 32 are arranged so that the end of the first gear 31 on the side where the sag Ma is formed and the end of the second gear 32 opposite to the side where the sag Ma is formed are located on the same plane, the meshing allowance ε of the external teeth 31b and the internal teeth 32a in the tooth width direction becomes smaller than the tooth width L2 of the internal teeth 32a. Therefore, by adopting the configuration shown in FIG. 11(a), it is possible to ensure a large meshing margin ε between the external teeth 31b and the internal teeth 32a, and therefore it is possible to appropriately strengthen the restriction of the rotation of the output shaft 2.

[0061] Although the clutch unit 1 according to the embodiment of the present invention has been described above, appropriate modifications can be made to the clutch unit 1 without departing from the gist of the present invention. For example, the output clutch 20 can be configured with a clutch other than the roller clutch described above.

[0062] The present invention can be embodied in various forms without departing from the spirit and scope of the present invention. The scope of the present invention is defined by the claims, and includes the equivalent meanings of the claims and all modifications within the scope of the claims. [Explanation of symbols]

[0063] 1 Clutch unit 2 Output shaft 3. Housing 4 Operating lever 5 Lever body 6 Operation board 7 Support bush 10 Input clutch 20 Output clutch 30 Locking mechanism 31 1st gear (1st locking element) 31b External teeth 32 2nd gear (2nd locking element) 32a internal teeth L1 (external teeth) face width L2 (internal teeth) face width M Metal plate Ma who

Claims

1. an input clutch that controls transmission and interruption of torque input by lever operation; an output side clutch that is in a locked state when there is no lever operation, restricting the rotation of the output shaft about its axis to cut off reverse input torque input to the output shaft, and a locking mechanism that restricts the rotation of the output shaft at an axial position different from that of the output side clutch, The lock mechanism is a clutch unit in which external teeth of a first locking element that rotates integrally with the output shaft mesh with internal teeth of a second locking element whose rotation about the axis of the output shaft is restricted, thereby restricting rotation of the output shaft, and in which the meshed state between the external teeth and the internal teeth is released by axial movement of the second locking element in response to a lever operation, A clutch unit, characterized in that a tooth width of the internal teeth of the second locking element is made smaller than a tooth width of the external teeth of the first locking element.

2. The external teeth are formed by stamping a metal plate that serves as a base material for the first locking element, The internal teeth are formed by stamping a metal plate that serves as a base material for the second locking element, 2. The clutch unit according to claim 1, wherein the first locking element and the second locking element are arranged such that ends of the external teeth and the internal teeth on the punching end side are positioned on the same plane when no lever operation is performed.

3. 2. The clutch unit according to claim 1, wherein the first locking element has an integral cylindrical fixing portion fixed to an outer circumferential surface of the output shaft, and the fixing portion is not in contact with any member other than the first locking element in the axial direction.

4. 2. The clutch unit according to claim 1, wherein the output side clutch comprises a stationary member whose rotation about the axis of the output shaft is restricted, and a roller disposed in a wedge gap formed between the output shaft and the stationary member, and the locked state is achieved by the roller engaging with the output shaft and the stationary member in the circumferential direction of the output shaft.

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