JP2013061049A - Clutch - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a clutch that can reliably intercept reverse input.SOLUTION: The clutch 1 includes: a housing 4 provided with a substrate 12 and a bottom plate 22; an input shaft 5 which is supported by the substrate in a rotatable manner around an axis and axially unmovable manner; an output shaft 6 which is supported by the bottom plate in a rotatable manner around an axis and axially unmovable manner to be coaxial with input axis and is connected to the input axis to be relatively rotatable in a prescribed angular range around the axix; a sleeve 7 which is supported by the input shaft and the output shaft rotatably and axialy movably; and a compression coil spring 8 which is disposed between the output shaft and the sleeve and biases the sleeve to the substrate side, wherein the input shaft includes a first cam 37, the output shaft includes a second cam 57 and the sleeve includes an engagement part 80 which is engaged with the substrate and generates a resistance force to the rotation of the sleeve, a third cam 72 engaged with the first cam and a fourth cam 77 engaged with the second cam.

Description

  The present invention relates to a clutch, and more specifically, has an input shaft and an output shaft. When a rotational force is applied to the input shaft, the output shaft rotates together with the input shaft, and the rotational force is applied to the output shaft. The present invention relates to a clutch that prevents rotation of the input shaft.

  In a clutch having an input shaft and an output shaft, the output shaft is driven when a rotational force is applied to the input shaft, while a rotational force is not applied to the input shaft when a rotational force is applied to the output shaft. A clutch having a reverse input blocking mechanism is known (for example, Patent Document 1). A clutch according to Patent Document 1 includes a housing having a first support portion and a second support portion, an input shaft that is rotatably supported by the first support portion and includes a first cam, and is coaxial with the input shaft. 2 an output shaft rotatably supported by the support portion, a second cam that is supported by the output shaft so as not to rotate relative to the output shaft and is movable in the axial direction, and engages with the first cam. A sleeve having a joint portion; and a biasing member that biases the sleeve toward the first support portion so as to engage the engagement portion and the first support portion. When a rotational force is applied to the input shaft, the first cam drives the second cam, thereby displacing the sleeve in a direction away from the first support portion, and the engagement portion and the first support portion. The engagement is released, and the rotation of the input shaft is transmitted to the output shaft through the sleeve. On the other hand, when a rotational force is applied to the output shaft, the rotation of the output shaft is restricted because the rotation of the sleeve relative to the housing is restricted by the engagement between the engaging portion and the first support portion. Is prevented from rotating.

JP 2000-199532 A

  However, in the clutch according to Patent Document 1, since the engagement between the engagement portion and the first support portion is maintained by the urging force of the urging member, the rotational force applied to the output shaft is the urging force of the urging member. If larger, there is a problem that the engagement between the engaging portion and the first support portion is released, and rotation is transmitted to the input shaft. That is, the rotational force that can be cut off is determined by the biasing force of the biasing member and is relatively small.

  This invention is made in view of the above problem, Comprising: It aims at providing the clutch which can interrupt | block a reverse input reliably.

  In order to solve the above problems, a clutch (1) according to the present invention includes a housing (4) having a first support portion (12) and a second support portion (22), and an axis around the first support portion. An input shaft (5) supported so as to be rotatable and immovable in the axial direction, and supported by the second support portion so as to be rotatable about the axis and immovable in the axial direction so as to be coaxial with the input shaft, An output shaft (6) connected to the input shaft so as to be rotatable relative to the input shaft within a predetermined angle range, rotatable to at least one of the input shaft and the output shaft, and of the input shaft and the output shaft. A sleeve (7) supported so as to be displaceable in the axial direction, and a biasing member (8) provided between the input shaft or the output shaft and the sleeve and biasing the sleeve toward the first support portion. And the input shaft includes a first cam (37). The output shaft includes a second cam (57), and the sleeve engages with the first support portion to generate a resistance force against the rotation of the sleeve relative to the first support portion ( 80), a third cam (72) that engages with the first cam, and a fourth cam (77) that engages with the second cam. In the initial state, the biasing member is biased. When the sleeve is positioned on the first support portion side, the engagement portion engages with the first support portion, and a rotational force to the housing is applied to the input shaft, One cam drives the third cam to displace the sleeve toward the second support portion against the biasing force of the biasing member to engage the engagement portion with the first support portion. The output shaft is rotated together with the input shaft, and the output shaft with respect to the housing is rotated. When a rolling force is applied, the second cam presses the fourth cam to press the sleeve toward the first support portion, and the engagement portion and the first support portion are engaged. In addition, the rotation of the output shaft relative to the housing is prevented when the second cam abuts against the fourth cam.

  According to this configuration, the clutch transmits the rotational force to the output shaft when a rotational force is applied to the input shaft, but does not transmit the rotational force to the input when the rotational force is applied to the output shaft. . In particular, when a rotational force is applied to the output shaft, the sleeve 7 that restricts the rotation of the output shaft is pressed by the second cam of the output shaft to further increase the engagement with the first support portion. The rotation of the shaft can be reliably controlled.

  In another aspect of the present invention, the engagement portion is a friction engagement portion formed on an end surface of the sleeve, and is brought into contact with the first support portion so as to be between the sleeve and the first support portion. It is characterized by generating resistance.

  According to this configuration, when the engaging portion is engaged with the first support portion, it is possible to apply a rotational resistance force to the first support portion to the sleeve.

  In another aspect of the present invention, the friction engagement portion includes a plurality of peaks and valleys extending in a radial direction of the sleeve, and the first support portion includes a seat portion (14) that meshes with the peaks and valleys. It is characterized by providing.

  According to this configuration, when the engaging portion engages with the first support portion, it is possible to increase the rotational resistance force applied to the sleeve.

  In another aspect of the present invention, the first cam, the second cam, the third cam, and the fourth cam are annular end face cams centering on axes of the input shaft and the output shaft. Features.

  According to this configuration, the sleeve can be driven with high stability with respect to the rotation of the input shaft or the output shaft.

  Another aspect of the present invention is characterized in that the second cam includes a reinforcing rib (62) on the side opposite to the side facing the third cam.

  According to this configuration, the deformation of the second cam can be suppressed.

  In another aspect of the present invention, the biasing member is a compression coil spring, and is disposed so as to surround the input shaft in a gap formed between an outer peripheral surface of the input shaft and an inner peripheral surface of the sleeve. One end abuts on the sleeve and the other end abuts on the output shaft.

  According to this configuration, the compression coil spring can be prevented from falling.

  According to the above structure, the clutch which can interrupt | block a reverse input reliably can be provided.

The exploded perspective view of the clutch concerning an embodiment The perspective view of the 1st housing concerning an embodiment The perspective view of the input shaft which concerns on embodiment The perspective view of the output shaft concerning an embodiment The perspective view of the sleeve which concerns on embodiment The perspective view of the sleeve which concerns on embodiment Side view of clutch according to embodiment VIII-VIII sectional view of FIG. IX-IX sectional view of FIG. It is a schematic diagram which shows operation | movement of a clutch, Comprising: (A) Initial state, (B) State where rotational force was applied to input shaft, (C) State where rotational force applied to input shaft was lost It is a schematic diagram which shows operation | movement of a clutch, Comprising: (D) The state where rotational force was applied to the output shaft is shown

  Hereinafter, an embodiment in which the present invention is applied to a clutch that transmits power from an electric motor to another mechanism will be described in detail with reference to the drawings. In the clutch according to this embodiment, the input side is connected to the electric motor, the output side is connected to another mechanism, and the rotational force applied from the electric motor to the input side is transmitted to the output side, while the other mechanism is connected to the output side. The applied rotational force is not transmitted to the input side. The clutch according to the present embodiment is applied to, for example, an electric opening / closing curtain mechanism that opens and closes a curtain by the power of an electric motor.

  As shown in FIG. 1, the clutch 1 according to the embodiment includes a housing 4 including a first housing 2 and a second housing 3, an input shaft 5, an output shaft 6, a sleeve 7, a compression coil spring (biasing force). Member) 8. Each member has a predetermined axis and is assembled so that each axis coincides with the rotation axis A of the clutch 1. In the following description, each member will be described with reference to the axis A. For the sake of explanation, as shown in FIG. 1, in the direction of the axis A, the side on which the input shaft 5 is provided with respect to the housing 4 is the input side, and the side on which the output shaft 6 is provided with respect to the housing 4 is output. Let it be the side.

  The first housing 2, the second housing 3, the input shaft 5, the output shaft 6, and the sleeve 7 are formed by injection molding of resin. The resin may be a thermoplastic resin such as polyacetal (POM). In other embodiments, each member may be made of metal.

  As shown in FIGS. 1 and 2, the first housing 2 includes a cylindrical inner cylinder 11 having an axis A as an axis, and a substrate (first support portion) 12 provided to close one end of the inner cylinder 11. The other end of the inner cylinder 11 is open. The substrate 12 is arranged so that its main surface is perpendicular to the axis A. The substrate 12 extends outward in the radial direction of the inner cylinder 11 and forms a flange. A first bearing hole 13 that is a circular through hole is formed in the substrate 12 coaxially with the inner cylinder 11. The diameter of the first bearing hole 13 is smaller than the inner diameter of the inner cylinder 11.

  The inner peripheral side portion of the annular portion surrounded by the inner peripheral edge of the inner cylinder 11 and the hole edge of the first bearing hole 13 that is the main surface of the substrate 12 is formed into a flat surface, and the outer peripheral side portion is described later. Thus, a seat portion 14 with which the sleeve 7 abuts is formed. The seat portion 14 is provided with a plurality of triangular peaks extending in the radial direction of the inner cylinder 11 in the circumferential direction. Thereby, the surface of the seat part 14 has a zigzag waveform in which peaks and valleys are alternately repeated in the circumferential direction.

  The inner cylinder 11 is formed with a U-shaped slit 16 that penetrates from the outer peripheral surface to the inner peripheral surface, and a cantilevered elastic claw 17 is formed in a portion surrounded by the slit 16. Is formed. The elastic claw 17 includes a claw portion protruding outward in the radial direction of the inner cylinder 11. In the present embodiment, the slit 16 and the elastic claw 17 are also provided at a 180 ° rotation position with the axis A of the inner cylinder 11 as the axis of symmetry. In another embodiment, three or more slits 16 and elastic claws 17 may be formed, and may be arranged at any position of the inner cylinder 11.

  As shown in FIG. 1, the second housing 3 includes a cylindrical outer cylinder 21 having an axis A as an axis, and a bottom plate (second support portion) 22 provided to close one end of the outer cylinder 21. The other end of the outer cylinder 21 is open. A second bearing hole 23 that is a circular through hole is formed in the bottom plate 22 coaxially with the outer cylinder 21. A circular boss 24 projects from the outer surface side of the bottom plate 22 at the edge of the second bearing hole 23 so as to extend the second bearing hole 23. The opening end on the inner end side of the second bearing hole 23 is reduced in diameter so as to advance toward the outer end side, and the opening end on the outer end side is a circular hole having an equal diameter.

  A locking hole 26 is provided in the outer cylinder 21. In the present embodiment, a pair of locking holes 26 are provided, and are formed at 180 ° rotationally symmetric positions with the axis A as the axis of symmetry. In other embodiments, the locking holes 26 may be formed according to the number and position of the elastic claws 17. The locking hole 26 penetrates from the inner peripheral surface of the outer cylinder 21 to the outer peripheral surface. In another embodiment, the locking hole 26 may be a bottomed hole that is recessed in the inner peripheral surface of the outer cylinder 21.

  As shown in FIG. 7, the first housing 2 and the second housing 3 are coaxially combined to form one housing 4. The inner cylinder 11 of the first housing 2 is inserted into the outer cylinder 21 of the second housing 3, and the elastic claw 17 of the first housing 2 is locked in the locking hole 26 of the second housing 3, thereby The coupling state between the housing 2 and the second housing 3 is maintained. At this time, the opening end of the inner cylinder 11 contacts the bottom plate 22 of the second housing 3, the opening end of the outer cylinder 21 contacts the substrate 12 of the first housing 2, and the outer peripheral surface of the inner cylinder 11 is the outer cylinder 21. By making sliding contact with the inner peripheral surface, the first housing 2 and the second housing 3 are coupled without rattling.

  As shown in FIGS. 1 and 3, the input shaft 5 has a cylindrical shaft portion 31 having an axis A as an axis. A part of the outer peripheral surface of the shaft portion 31 may be cut off. A coupling end portion 32 is formed at one end of the shaft portion 31. The coupling end portion 32 is formed to be flatter than the shaft portion 31, and its cross section is accommodated in the outer shape of the shaft portion 31. The coupling end portion 32 has a central portion 33 that is coaxially continuous with the shaft portion 31 and forms a column with a smaller diameter than the shaft portion 31, and a protruding portion 34 that protrudes in the radial direction from the outer peripheral portion of the central portion 33. ing. In the present embodiment, a pair of protruding portions 34 are provided and protrude from the central portion 33 in directions opposite to each other. In other embodiments, the number of protrusions 34 may be one, or three or more. The protruding end of the protruding portion 34 in the radial direction of the shaft portion 31 reaches the outer peripheral surface of the shaft portion 31. A bottomed key hole 35 is formed on the other end surface of the shaft portion 31 (see FIG. 8).

  An annular first flange 36 is formed on the outer peripheral surface of the shaft portion 31 so as to protrude outward in the radial direction and extend in the circumferential direction of the shaft portion 31. The protruding end surface of the first flange portion 36 forms a circumferential surface with the axis A as the center. A portion of the first flange 36 facing the output side in the direction of the axis A is formed with a first cam 37 that is an annular end face cam centering on the axis A. In the present embodiment, the first cam 37 is a cam having a cycle of 180 °, and one peak portion 38 protruding to the output side in the direction of the axis A within one cycle and one valley portion recessed to the input side. 39. The peak portion 38 and the valley portion 39 are continuous with a smooth curved surface. In other embodiments, the cycle and shape of the first cam 37 may be changed as appropriate. A contact surface 41 that is a plane perpendicular to the axis A is formed in a portion of the first flange 36 that faces the input side in the direction of the axis A.

  The input shaft 5 is rotatably supported in the first bearing hole 13 at the end portion 42 on the input side of the first flange portion 36 of the shaft portion 31 (see FIG. 8). The insertion depth of the shaft portion 31 with respect to the first bearing hole 13 is regulated by the contact surface 41 coming into contact with the peripheral edge portion of the first bearing hole 13. With the end portion 42 of the shaft portion 31 supported by the first bearing hole 13, the first flange portion 36 and the coupling end portion 32 are disposed inside the inner cylinder 11.

  As shown in FIGS. 1 and 4, the output shaft 6 includes a cylindrical small-diameter shaft portion 51 having an axis A as an axis, and a large-diameter shaft portion 52 that is coaxially continuous with one end of the small-diameter shaft portion 51. The outer surface of the large-diameter shaft portion 52 is generally a circumferential surface, and a part thereof is cut away. The outer diameter of the large-diameter shaft portion 52 is formed larger than the outer diameter of the small-diameter shaft portion 51.

  As shown in FIG. 4, a bottomed coupling hole 53 is recessed in the end surface of the large-diameter shaft portion 52. As shown in FIG. 8, the coupling end 32 of the input shaft 5 is inserted into the coupling hole 53. When the protruding end of the coupling end portion 32 is in sliding contact with the bottom surface of the coupling hole 53, the insertion depth of the coupling end portion 32 into the coupling hole 53 is regulated. 4 and 9, the coupling hole 53 is provided at the center of the large-diameter shaft portion 52, and a central chamber 54 in which the central portion 33 of the coupling end portion 32 is rotatably fitted, and the central chamber 54 side. And a side chamber 55 that extends radially outward from the central chamber 54 and into which the projecting portion 34 is loosely fitted. In the present embodiment, a pair of side chambers 55 are provided so as to extend from the central chamber 54 in directions opposite to each other, and the cross section of the coupling hole 53 is approximately eight characters. As a result, when the protruding portion 34 of the coupling end portion 32 is displaced in the side chamber 55, the input shaft 5 and the output shaft 6 can be rotated relative to each other around the axis A, and the side wall of the protruding portion 34 and the side chamber 55. When the input shaft 5 or the output shaft 6 rotates in the direction in which the contact is maintained, the input shaft 5 and the output shaft 6 rotate integrally around the axis A. That is, the input shaft 5 and the output shaft 6 are coaxially connected so as to be relatively rotatable in a predetermined angle range by the engagement between the coupling end portion 32 and the coupling hole 53. As shown in FIG. 9, the relative rotational position of the input shaft 5 and the output shaft 6 when each projecting portion 34 is disposed at the center of each side chamber 55 is defined as a neutral position. In the present embodiment, the input shaft 5 is rotated forward from the neutral position with respect to the output shaft 6 (the direction in which the input shaft 5 rotates clockwise with respect to the output shaft 6 when viewed from the input side along the axis A). It can rotate 30 ° in the negative rotation direction (the direction in which the input shaft 5 rotates counterclockwise with respect to the output shaft 6 when viewed from the input side along the axis A). In other embodiments, the shape of the coupling hole 53, that is, the number, position, and shape of the side chamber 55 may be appropriately changed according to the shape of the coupling end portion 32, that is, the number, position, and shape of the protrusions 34. Further, the relative rotatable range of the input shaft 5 and the output shaft 6 from the neutral position may be appropriately changed.

  An annular second flange 56 is formed on the outer peripheral surface of the large-diameter shaft portion 52 and protrudes radially outward and extends in the circumferential direction of the large-diameter shaft portion 52. A portion of the second flange 56 facing the input side in the direction of the axis A is formed with a second cam 57 that is an annular end face cam centering on the axis A. In the present embodiment, the second cam 57 is a cam having a cycle of 180 °, and one peak portion 58 protruding to the input side in the direction of the axis A within one cycle and one valley portion recessed to the output side. 59. The peak portion 58 and the valley portion 59 are continuous with a smooth curved surface. In other embodiments, the cycle and shape of the second cam 57 may be changed as appropriate. An annular contact portion 61 centering on the axis A is provided at a portion of the second flange 56 facing the output side in the direction of the axis A. The protruding end of the annular contact portion 61 is disposed on a virtual plane perpendicular to the axis A. In addition, a plurality of reinforcing ribs 62 extending to the outer peripheral portion of the small-diameter shaft portion 51 project from the portion surrounded by the annular contact portion 61 of the second flange portion 56. The plurality of reinforcing ribs 62 are arranged radially on the outer peripheral portion of the small diameter shaft portion 51. The rigidity of the second flange 56 and the second cam 57 is increased by the reinforcing rib 62, and deformation is suppressed. A bottomed key hole 63 is formed on the end surface of the small-diameter shaft portion 51 (see FIG. 8).

  The output shaft 6 is rotatably supported in the second bearing hole 23 of the second housing 3 at the small diameter shaft portion 51. At this time, the insertion depth of the small-diameter shaft portion 51 with respect to the second bearing hole 23 is regulated by the annular contact portion 61 contacting the peripheral edge portion of the second bearing hole 23.

  As shown in FIG. 8, the input shaft 5 is supported by the first housing 2, the output shaft 6 is supported by the second housing 3, and the input housing is coupled with the first housing 2 and the second housing 3. 5 is in contact with the peripheral edge of the first bearing hole 13, the annular contact part 61 of the output shaft 6 is in contact with the peripheral edge of the second bearing hole 23, and the coupling end 32 of the input shaft 5 is Since the protruding end comes into contact with the bottom of the coupling hole 53 of the output shaft 6, the input shaft 5 and the output shaft 6 cannot move in the direction of the axis A with respect to the housing 4. Further, when the input shaft 5 and the output shaft 6 are connected and positioned at the neutral position, the peak portion 38 of the first cam 37 and the valley portion 59 of the second cam 57 in the axis A direction are in the axis A direction. It is designed to face each other.

  As shown in FIGS. 1, 5 and 6, the sleeve 7 has a cylindrical shape with the axis A as the axis. The inner diameter of the sleeve 7 is set to a size that can receive the first flange portion 36 and the large-diameter shaft portion 52, and the outer diameter is set to a size that can be inserted into the inner cylinder 11. . The inner diameter of the sleeve 7 is preferably formed such that the inner circumferential surface thereof can be slidably contacted with the outer circumferential surfaces of the first flange portion 36 and the large-diameter shaft portion 52. Further, the outer diameter of the sleeve 7 may be formed such that the outer peripheral surface thereof can be in sliding contact with the inner peripheral surface of the inner cylinder 11. The sleeve 7 is supported by the connected input shaft 5 and output shaft 6 so as to be coaxial and rotatable about the axis A.

  On the inner peripheral surface of the sleeve 7, an annular third collar 71 is formed that protrudes inward toward the axis A and extends in the circumferential direction. The protruding end (inner end) of the third flange portion 71 is formed on a circumferential surface that can slide in contact with the outer circumferential surface of the shaft portion 31. A third cam 72 is formed on a portion of the third flange portion 71 facing the first cam 37 (a portion facing the input side in the axis A direction). The third cam 72 is an annular end face cam centering on the axis A having a shape complementary to that of the first cam 37. The third cam 72 protrudes on the input side in the direction of the axis A, and the valley recessed on the output side. Part 74.

  As shown in FIGS. 6 and 8, the portion of the third flange 71 that faces the output side in the direction of the axis A is an annular spring seat 75 formed on a plane perpendicular to the axis A. The spring seat 75 faces the end surface of the large-diameter shaft portion 52 in the axis A direction.

  An end portion on the output side of the sleeve 7 faces the second cam 57, and an end surface thereof is a fourth cam 77. The fourth cam 77 is an annular end face cam centering on the axis A having a shape complementary to the second cam 57, and has a peak portion 78 protruding to the output side in the direction of the axis A and a valley recessed to the input side. Part 79. The third cam 72 and the fourth cam 77 are provided such that the peak portion 73 and the valley portion 79 correspond to each other in the axis A direction, and the valley portion 74 and the peak portion 78 correspond to each other.

  The other end of the sleeve 7 faces the seat portion 14 of the first housing 2, and is an engaging portion 80 that can be engaged with the seat portion 14. The engaging portion 80 is formed in a complementary shape to the seat portion 14 and has a zigzag waveform in which peaks and valleys are alternately arranged.

  Since the third cam 72 faces the first cam 37 of the input shaft 5 and the fourth cam 77 faces the second cam 57 of the output shaft 6, the sleeve 7 has an axis line with respect to the input shaft 5 and the output shaft 6. The displacement in the A direction is limited to a predetermined range. The sleeve 7 is connected to the input shaft 5 so that the peak 73 of the third cam 72 faces the valley 39 of the first cam 37 and the peak 78 of the fourth cam 77 faces the valley 59 of the second cam 57. And the output shaft 6. The rotational range of the sleeve 7 around the axis A with respect to the input shaft 5 and the output shaft 6 is such that the crest 73 of the third cam 72 hits the crest 38 of the first cam 37 and the crest 78 of the fourth cam 77 is the second. It is regulated by abutting against the mountain portion 58 of the cam 57. That is, the crest 73 of the third cam 72 cannot cross the crest 38 of the first cam 37 in the circumferential direction, and the crest 78 of the fourth cam 77 has a crest 58 of the second cam 57 in the circumferential direction. It cannot be exceeded.

  As shown in FIGS. 1 and 8, the compression coil spring 8 surrounds the shaft portion 31 in an annular space defined between the outer peripheral surface of the shaft portion 31 of the input shaft 5 and the inner peripheral surface of the sleeve 7. One end of which contacts the end surface of the large-diameter shaft portion 52 and the other end contacts the spring seat 75 of the sleeve 7. As a result, the sleeve 7 is urged toward the input side in the direction of the axis A with respect to the output shaft 6 by the compression coil spring 8, that is, toward the substrate 12.

  Next, with reference to FIGS. 10 and 11, the effect of the clutch 1 configured as described above will be described. The clutch 1 according to this embodiment is used in a state where the housing 4 is fixed to another device or the like. An arbitrary rotating member such as an output shaft of an electric motor fitted into the key hole 35 is coupled to the input shaft 5, and another arbitrary rotating member fitted to the key hole 63 is coupled to the output shaft 6.

  10 and 11 show the input shaft 5, the output shaft 6, the sleeve 7, the first cam 37, the second cam 57, the third cam 72, the fourth cam 77, and the engaging portion in each state (A) to (D). 80 is a diagram schematically illustrating a positional relationship between the seat portion 14 and a positional relationship between the coupling end portion 32 and the coupling hole 53. FIG. FIG. 10A shows an initial state of the clutch 1. In the initial state, the input shaft 5 and the output shaft 6 are in a neutral position, and the peak portion 38 of the first cam 37 and the valley portion 59 of the second cam 57 are facing each other in the axis A direction. The sleeve 7 is biased by the compression coil spring 8 and is displaced to the input side (substrate 12 side), and the third cam 72 is in contact with the first cam 37 over the entire circumference, that is, in the direction of the axis A, the first cam 37. It is in the state that is closest. At this time, the sleeve 7 is engaged with the seat portion 14 of the first housing 2 at the engaging portion 80, and cannot rotate with respect to the first housing 2 (housing 4).

  In an initial state, the input shaft 5 is rotated in the normal rotation direction with respect to the housing 4 (the input shaft 5 rotates in the clockwise direction around the axis A with respect to the housing 4 when viewed from the input side along the axis A direction). When a force is applied, the input shaft 5 moves relative to the output shaft 6 in a rotation range (30 °) from the neutral position until the protruding portion 34 of the coupling end 32 abuts against the wall surface of the side chamber 55 of the coupling hole 53. Relative rotation. That is, the input shaft 5 idles with respect to the output shaft 6. At this time, the sleeve 7 cannot rotate with the input shaft 5 because the engaging portion 80 is engaged with the seat portion 14, and the third cam 72 is attached to the first cam 37 that rotates with the input shaft 5. Pressed and displaced to the output side against the urging force of the compression coil spring 8. Accordingly, as shown in FIG. 10B, the engagement between the engaging portion 80 and the seat portion 14 is released, and the sleeve 7 rotates together with the input shaft 5. After the projecting portion 34 of the coupling end portion 32 comes into contact with the wall surface of the side chamber 55 of the coupling hole 53, the output shaft 6 rotates integrally with the forward rotation of the input shaft 5. As described above, when a rotational force is applied to the input shaft 5, the output shaft 6 also rotates together. At this time, the peak portion 38 of the first cam 37 and the valley portion 59 of the second cam 57 are in a state of being deviated by 30 ° around the axis A.

  When the rotational speed of the input shaft 5 becomes constant and the sleeve 7 rotates together with the input shaft 5, the force with which the first cam 37 presses the third cam 72 to the output side decreases, and the urging force of the compression coil spring 8 As a result, the sleeve 7 may be displaced to the input side. In this case, when the engaging portion 80 and the seat portion 14 come into contact with each other, a speed difference is generated between the input shaft 5 and the sleeve 7, and the sleeve 7 is pressed against the first cam 37 by the third cam 72, It is displaced again to the input side. In order to suppress such displacement of the sleeve 7 toward the input side, a frictional force may be generated between the outer peripheral surface of the sleeve 7 and the inner peripheral surface of the inner cylinder 11 of the first housing 2. By generating a frictional force between the sleeve 7 and the inner cylinder 11, the input shaft 5 can always press the sleeve 7 to the output side during rotation.

  When the rotational force applied to the input shaft 5 disappears in the state of FIG. 10B, the input shaft 5 stops, and the output shaft 6 also stops accordingly. In this state, since the force that presses the third cam 72 of the sleeve 7 to the output side is lost, the sleeve 7 is biased by the compression coil spring 8 and displaced to the input side. At this time, the third cam 72 slides on the first cam 37, and the sleeve 7 is displaced to the input side while rotating around the axis A with respect to the input shaft 5. Then, as shown in FIG. 10C, the third cam 72 is in contact with the first cam 37 over the entire circumference, that is, in the state closest to the first cam 37 in the axis A direction. In this state, the sleeve 7 engages with the seat portion 14 of the first housing 2 at the engaging portion 80, and cannot rotate with respect to the first housing 2.

  In the state shown in FIG. 10C, when a rotational force is applied to the input shaft 5 in the forward rotation direction with respect to the housing 4, the input shaft 5 is in the sleeve 7 in the first cam 37 as in the initial state. Is displaced to the output side. At this time, the sleeve 7 is displaced to the output side while rotating with respect to the input shaft 5, and is in the same state as in FIG.

  Even when the input shaft 5 is rotated in the negative direction relative to the housing 4 (when the input shaft 5 is rotated in the clockwise direction around the axis A with respect to the housing 4 as viewed from the input side along the axis A direction) The output shaft 6 rotates in the same manner as when rotated in the direction. Similarly, when the rotational force applied to the input shaft 5 is lost, the sleeve 7 cannot rotate with respect to the first housing 2.

  Next, a case where a rotational force is applied to the output shaft 6 in a state where the rotation of the input shaft 5 is stopped (FIGS. 10A and 10C) will be described.

  In the initial state shown in FIG. 10A, when the output shaft 6 is rotated in the forward rotation direction with respect to the housing 4, the second cam 57 of the output shaft 6 is moved as shown in FIG. It contacts the fourth cam 77 of the sleeve 7. In the initial state, the sleeve 7 is engaged with the seat portion 14 at the engaging portion 80, and the rotation around the axis A is restricted. Therefore, in the state of FIG. Be regulated. At this time, since the output shaft 6 presses the fourth cam 77 with the second cam 57 and presses the sleeve 7 to the input side, the engagement between the engaging portion 80 and the seat portion 14 is further strengthened. Further, until the output shaft 6 rotates forward with respect to the housing 4 and the second cam 57 contacts the fourth cam 77, the coupling end 32 idles in the coupling hole 53, and the input shaft 5 outputs It does not rotate regardless of the rotation of the shaft 6. As described above, the rotational force applied to the output shaft 6 is not transmitted to the input shaft 5. The same applies when the output shaft 6 is rotated in the negative direction with respect to the housing 4.

  In a state where the peak portion 38 of the first cam 37 and the valley portion 59 of the second cam 57 shown in FIG. 10C are offset by 30 ° around the axis A, the output shaft 6 is rotated in the forward direction with respect to the housing 4. When rotated, the second cam 57 of the output shaft 6 comes into contact with the fourth cam 77 of the sleeve 7 as shown in FIG. 11D, and the rotation of the output shaft 6 is restricted. Until the output shaft 6 rotates forward with respect to the housing 4 and the second cam 57 contacts the fourth cam 77, the coupling end portion 32 idles in the coupling hole 53, and the input shaft 5 is connected to the output shaft 6. Does not rotate regardless of the rotation. While the coupling end portion 32 idles in the coupling hole 53, the positional relationship between the output shaft 6 and the input shaft 5 once returns to the neutral state. As described above, the rotational force applied to the output shaft 6 is not transmitted to the input shaft 5.

  In a state where the peak portion 38 of the first cam 37 and the valley portion 59 of the second cam 57 shown in FIG. 10C are offset by 30 ° around the axis A, the output shaft 6 is moved in the negative direction with respect to the housing 4. When rotating, since the second cam 57 is already in contact with the fourth cam 77, the negative rotation of the output shaft 6 is restricted. As described above, the rotational force applied to the output shaft 6 is not transmitted to the input shaft 5.

  As described above, the clutch 1 according to this embodiment transmits the rotational force to the output shaft 6 when the rotational force is applied to the input shaft 5 from the outside, and the rotational force is transmitted to the output shaft 6 from the outside. When applied, the rotational force is transmitted to the input shaft 5. In particular, when a rotational force is applied to the output shaft 6 from the outside, the sleeve 7 that restricts the rotation of the output shaft 6 is pressed by the second cam 57 of the output shaft 6, and the first housing 2 (housing 4). Therefore, the rotation of the output shaft 6 can be reliably restricted.

  Although the description of the specific embodiment is finished as described above, the present invention is not limited to the above embodiment and can be widely modified. For example, the configuration of the engaging portion 80 and the seat portion 14 according to the embodiment is an exemplification, and various modifications can be made. For example, the peaks and valleys of the engaging part 80 and the seat part 14 may be deleted so that the planes come into contact with each other. In this case, in order to increase the frictional force of each plane, the surface may be roughened by sandblasting or a high frictional force member such as rubber may be disposed. Further, the end portion on the input side of the sleeve 7 may be formed in a tapered surface (conical surface) that is tapered, and the seat portion 14 may be a truncated cone-shaped recess having a shape complementary to the tapered surface. In addition, the shape of each cam is an illustration, Comprising: It is not limited to the shape of embodiment.

  DESCRIPTION OF SYMBOLS 1 ... Clutch, 2 ... 1st housing, 3 ... 2nd housing, 4 ... Housing, 5 ... Input shaft, 6 ... Output shaft, 7 ... Sleeve, 8 ... Compression coil spring (biasing member), 12 ... Board | substrate (1st) 1 support part), 13 ... 1st bearing hole, 14 ... seat part, 22 ... bottom plate (2nd support part), 23 ... 2nd bearing hole, 32 ... coupling end part, 37 ... 1st cam, 51 ... small diameter shaft , 52 ... large diameter shaft part, 53 ... coupling hole, 57 ... second cam, 62 ... reinforcing rib, 72 ... third cam, 75 ... spring seat, 77 ... fourth cam, 80 ... engagement part, A ... Axis

Claims (6)

A housing having a first support portion and a second support portion;
An input shaft supported by the first support portion so as to be rotatable about an axis and immovable in the axial direction;
The second support portion is supported so as to be rotatable about the axis and not movable in the axial direction so as to be coaxial with the input shaft, and is connected to the input shaft so as to be relatively rotatable around the axis within a predetermined angle range. Output shaft,
A sleeve supported on at least one of the input shaft and the output shaft and capable of being displaced in the axial direction of the input shaft and the output shaft;
A biasing member that is provided between the input shaft or the output shaft and the sleeve and biases the sleeve toward the first support portion;
The input shaft includes a first cam;
The output shaft includes a second cam;
The sleeve is engaged with the first support portion to generate a resistance force to the rotation of the sleeve relative to the first support portion, a third cam engaged with the first cam, and the first A fourth cam engaged with the two cams,
In an initial state, the sleeve urged by the urging member is positioned on the first support portion side, and the engagement portion is engaged with the first support portion,
When a rotational force with respect to the housing is applied to the input shaft, the first cam drives the third cam to resist the biasing force of the biasing member to the second support side. To disengage the engagement portion and the first support portion and rotate the output shaft together with the input shaft,
When a rotational force with respect to the housing is applied to the output shaft, the second cam presses the fourth cam to press the sleeve toward the first support portion, and the engagement portion and the first cam The clutch is characterized in that the engagement of one support portion is maintained, and the rotation of the output shaft relative to the housing is prevented by the second cam abutting against the fourth cam.   The engagement portion is a friction engagement portion formed on an end face of the sleeve, and generates a frictional force between the sleeve and the first support portion by contacting the first support portion. The clutch according to claim 1. The friction engagement portion includes a plurality of peaks and valleys extending in the radial direction of the sleeve,
The clutch according to claim 2, wherein the first support portion includes a seat portion that meshes with the peaks and valleys.   The said 1st cam, the said 2nd cam, the said 3rd cam, and the said 4th cam are cyclic | annular end surface cams centering on the axis line of the said input shaft and the said output shaft, The 1st Claim-Claim 1 characterized by the above-mentioned. Item 4. The clutch according to any one of items 3.   The clutch according to claim 4, wherein the second cam includes a reinforcing rib on a side opposite to a side facing the third cam.   The urging member is a compression coil spring, and is disposed so as to surround the input shaft in a gap formed between an outer peripheral surface of the input shaft and an inner peripheral surface of the sleeve, and one end abuts the sleeve. The clutch according to any one of claims 1 to 5, wherein the other end abuts against the output shaft.

Images