JP6934916B2 - Free type bidirectional clutch - Google Patents

Description

The present invention includes a housing that is non-rotatably fixed, and an input member and an output member that are rotatably supported by the housing about a common central axis, both in the forward direction and in the reverse direction from the input member to the output member. The present invention relates to a free-type bidirectional clutch in which rotation in both directions is transmitted, but when the output member rotates, the output member idles and rotation is not transmitted from the output member to the input member.

In Patent Document 1 below, rotation in both the forward direction and the reverse direction is transmitted from the input member to the output member, while when the output member rotates, the output member idles and the output member to the input member A free type bidirectional clutch in which rotation is not transmitted is disclosed.

In the free-type bidirectional clutch disclosed in Patent Document 1 below, a shaft-shaped output member that can rotate in the forward and reverse directions is coaxial inside a cylindrical input member that can rotate in the forward and reverse directions. A cylindrical outer ring, which is housed above and has frictional resistance applied to the stationary system, is arranged outside the input member, and a coil spring that elastically holds the input member and the outer ring is not the output member. It is provided between the input member and the outer ring so as to be in contact with the output member in a contact state and by inputting a rotational torque from the input member.

In the free-type bidirectional clutch disclosed in Patent Document 1 below, when the input member rotates, the input member pushes the end of the coil spring in the rotational direction, which is larger than the frictional resistance given to the outer ring with respect to the stationary system. A coil spring having a small elastic force begins to bend. Due to the deflection of the coil spring, the inner diameter of the coil spring is reduced and comes into contact with the output member. Rotation is transmitted from the input member to the output member by the contact between the coil spring and the output member.

Further, in the free type bidirectional clutch disclosed in Patent Document 1 below, even if the output member rotates, the input member and the outer ring are elastically held in a neutral state by the elastic force of the coil spring, and the inner diameter of the coil spring is held. And the output member are not in contact with each other, and a gap is secured between the two members. As a result, the output member only idles, and rotation is not transmitted from the output member to the input member.

Further, in Patent Document 1 below, since the free type bidirectional clutch is configured with the input member, the output member, the outer ring and the coil spring as the main parts, the number of parts can be reduced and the assembly man-hours can be reduced. It is stated that the cost of the product can be reduced.

Japanese Unexamined Patent Publication No. 2008-256111

However, in the free type bidirectional clutch disclosed in Patent Document 1, not only the input member, the output member, the outer ring and the coil spring, but also the frictional resistance with respect to the stationary system (friction resistance larger than the elastic force of the coil spring) is applied. A member for imparting frictional resistance to the outer ring is indispensable. Without this friction resistance imparting member, when the input member rotates and one end of the coil spring is pushed by the input member, the outer ring is pushed and rotated by the other end of the coil spring. , The inner diameter of the coil spring does not shrink, and the coil spring does not come into contact with the output member. If the coil spring does not come into contact with the output member, the rotation is not transmitted from the input member to the output member. Therefore, in the free type bidirectional clutch disclosed in Patent Document 1, in addition to the input member, the output member, the outer ring and the coil spring, a friction resistance imparting member is indispensable, and there is room for improvement in reducing the number of parts. .. Note that Patent Document 1 does not disclose a specific configuration of the frictional resistance imparting member.

An object of the present invention made in view of the above facts is to provide a free-type bidirectional clutch capable of further reducing the number of parts.

The present invention provides the following free-type bidirectional clutch in order to solve the above problems. That is, it includes a housing that is non-rotatably fixed, and an input member and an output member that are rotatably supported by the housing about a common central axis, and from the input member to the output member in the positive direction and A free-type bidirectional clutch in which rotation in both directions is transmitted, but when the output member rotates, the output member slips and rotation is not transmitted from the output member to the input member. The housing has a cylindrical inner peripheral surface, a restraining means is formed on the inner peripheral surface, a coil spring is housed in the housing, and both ends of the coil spring in the axial direction face the restraining means. A pair of restrained means extending and being freely restrained by the restraining means is formed, the pair of restrained means are arranged at intervals in the circumferential direction, and the input members are arranged in the circumferential direction. The output member includes a mounted portion that is arranged radially inside the coil spring and has a cylindrical outer peripheral surface, and the outer diameter of the mounted portion is the pair. When both of the restrained means are smaller than the inner diameter of the coil spring in the state of being restrained by the restraining means and the input member rotates to one side in the circumferential direction, one of the pair of restrained means is said by the pressing means. The restraint by the restraining means is released by being pushed in the winding direction of the coil spring and elastically deforming, while the other of the pair of restrained means continues to be restrained by the restraining means, so that the diameter of the coil spring is increased. In a state where the coil spring is reduced and brought into close contact with the mounted portion, and the coil spring is brought into close contact with the mounted portion, the input member further rotates to one side in the circumferential direction, and one of the pair of restrained means is said. The present invention provides a free-type bidirectional clutch in which rotation is transmitted from the input member to the output member via the coil spring in close contact with the mounted portion when the clutch is further pushed in the winding direction by the pressing means.

Preferably, the input member includes a disc-shaped base, and the pressing means is composed of an arc-shaped piece extending axially from the peripheral edge of the base. The input member includes a disk-shaped base portion, and a protruding portion that protrudes from one side surface of the base portion to one side in the axial direction and is located inside the coil spring in the radial direction and faces the mounted portion of the output member. The protruding portion has a cylindrical outer peripheral surface, and the outer diameter of the protruding portion and the outer diameter of the mounted portion are the same. It is preferable that the coil springs are in close contact with each other. A circular protrusion that protrudes in the axial direction about the central axis is formed on one of the protruding portion of the input member and the mounted portion of the output member, and the protruding portion and the mounted portion are formed on the other side. It is convenient that a circular recess is formed in which the circular protrusion is rotatably inserted. The restraining means of the housing is composed of a trochoidal tooth profile in which a plurality of concave portions and a plurality of convex portions are alternately arranged, and each of the pair of restrained means of the coil spring is formed from an axial end portion of the coil spring. It is composed of hooks extending outward and then folded back in an arc shape, and the curvature of the arc-shaped portion of the pair of restrained means is preferably larger than the curvature of the recess.

In the free-type bidirectional clutch of the present invention, when the input member rotates to one side in the circumferential direction, one of the restrained means is pushed by the pressing means in the winding direction of the coil spring and elastically deformed, so that the restraint by the restraining means is released. On the other hand, in the other restrained means, the diameter of the coil spring is reduced and the coil spring is brought into close contact with the mounted portion as the restraint by the restraining means continues. When the input member further rotates to one side in the circumferential direction while the coil spring is in close contact with the mounted portion and one of the restrained means is further pushed in the winding direction by the pressing means, the input member is further pushed in the winding direction by the pressing means, via the coil spring in close contact with the mounted portion. Rotation is transmitted from the input member to the output member. Further, even when the input member rotates to the other side in the circumferential direction, the rotation is transmitted from the input member to the output member via the coil spring in close contact with the mounted portion, as in the case where the input member rotates to one side in the circumferential direction. Will be done.

In the free-type bidirectional clutch of the present invention, since the outer diameter of the mounted portion of the output member is smaller than the inner diameter of the coil spring when both of the pair of restrained means are restrained by the restraining means, the output member rotates. At that time, the output member slips inside the coil spring in the radial direction, and the rotation is not transmitted from the output member to the input member.

Therefore, in the free-type bidirectional clutch of the present invention, the housing, the input member, the output member, and the coil spring can be configured as the main parts, so that the number of parts can be further reduced.

(A) A front view of a free-type bidirectional clutch configured according to the present invention, a sectional view taken along line AA in (b) and (a), a sectional view taken along line BB in (c) and (b), (d) ( FIG. 2C is a cross-sectional view taken along the line CC in b). An exploded perspective view of the free-type bidirectional clutch shown in FIG. 1 as viewed from the housing body side. An exploded perspective view of the free type bidirectional clutch shown in FIG. 1 as viewed from a shield member. (A) A rear view of the housing body shown in FIG. 1, and a cross-sectional view taken along the line AA in (b) and (a). FIG. 3 is a cross-sectional view corresponding to FIG. 1 (d) when the input member shown in FIG. 1 is rotated.

Hereinafter, preferred embodiments of the free-type bidirectional clutch configured according to the present invention will be described with reference to the drawings.

As shown in FIGS. 1 to 3, the free-type bidirectional clutch, which is indicated by reference numeral 2, is rotatably supported by the housing 4 which is fixed so as not to rotate and the housing 4 which is rotatably centered on the common central axis O. The input member 6 and the output member 8 are provided.

As shown in FIGS. 2 and 3, the housing 4 that can be formed of an appropriate synthetic resin includes a bottomed cylindrical housing body 10 and a disk-shaped shield member 12 that covers the open side end of the housing body 10. include. As shown in FIG. 4, the housing main body 10 has a circular end face wall 14 and a cylindrical peripheral wall 16 extending from the peripheral edge of the end face wall 14 to one side in the axial direction. A circular support opening 18 is formed in the central portion of the end face wall 14. An annular support recess 20 extending radially outward from the peripheral edge of the support opening 18 is formed on the inner surface of the end face wall 14.

As shown in FIGS. 2 to 4, a plurality of fitting grooves 22 extending in the axial direction are formed on the outer peripheral surface of the peripheral wall 16 at intervals in the circumferential direction. The housing 4 is non-rotatably fixed by fitting a fitting projection (not shown) into each fitting groove 22.

As shown in FIGS. 3 and 4, the peripheral wall 16 has a cylindrical inner peripheral surface, and a restraining means 24 is formed on the inner peripheral surface of the peripheral wall 16. The restraining means 24 of the illustrated embodiment is composed of a trochoidal tooth profile in which a plurality of arcuate concave portions 24a and a plurality of arcuate convex portions 24b are alternately arranged. As understood by referring to FIG. 4A, the plurality of concave portions 24a and the plurality of convex portions 24b are formed over the entire circumferential direction of the inner peripheral surface of the peripheral surface wall 16.

As shown in FIGS. 3 and 4, an annular mounting recess on which the shield member 12 is mounted is provided on the inner peripheral surface of the open side end portion (axial end portion on the opposite side of the end face wall 14) of the peripheral surface wall 16. 26 is formed. As understood by referring to FIG. 4, the mounting recess 26 is recessed radially outward of the recess 24a of the restraint means 24. An annular groove 28 is formed in the axially intermediate portion of the mounting recess 26 so as to immerse further outward in the radial direction.

As shown in FIGS. 2 and 3, a circular support opening 30 is formed in the central portion of the shield member 12. As shown in FIG. 2, an annular support recess 32 extending radially outward from the peripheral edge of the support opening 30 is formed on the inner surface of the shield member 12. An annular protrusion 34 is formed on the outer peripheral surface of the shield member 12 so as to project outward in the radial direction. As shown in FIG. 1B, the shield member 12 is press-fitted into the mounting recess 26 of the housing body 10, and the annular protrusion 34 is fitted into the annular groove 28 of the housing body 10 to be mounted on the housing body 10. There is.

As shown in FIGS. 1 (b) to 1 (d), a cylindrical coil spring 36 is housed in the housing 4. The winding direction of the coil spring 36 is counterclockwise when viewed from the right side of FIG. Explaining with reference to FIGS. 1 to 3, both ends of the coil spring 36, which can be formed of an appropriate metal material such as a steel material, extend toward the restraining means 24 of the housing 4 and can be freely released by the restraining means 24. A pair of constrained means 38 are formed. The pair of restrained means 38 are arranged so as to be spaced apart from each other in the circumferential direction.

The restrained means 38 of the illustrated embodiment is composed of a hook extending outward from the axial end portion of the coil spring 36 and then folded back in an arc shape. In the illustrated embodiment, as shown in FIG. 1D, the pair of restrained means 38 extend tangentially from the positions facing each other in the radial direction of the coil spring 36. The curvature of the arcuate portion 38a located at the tip of the restrained means 38 is larger than the curvature of the recess 24a of the restrained means 24. Therefore, the arc-shaped portion 38a is fitted into the recess 24a, and the tip of the arc-shaped portion 38a is in contact with the recess 24a. The restrained means 38 is freely restrained by the restraining means 24 by the frictional force generated between the tip of the arc-shaped portion 38a and the recess 24a.

The input member 6 can be formed of an appropriate metal material such as a steel material or an appropriate synthetic resin. As shown in FIGS. 1 (c) and 1 (d), the input member 6 includes pressing means 40 facing a pair of restrained means 38 of the coil spring 36 in the circumferential direction. In the illustrated embodiment, as shown in FIGS. 2 and 3, the input member 6 includes a disk-shaped base portion 42, and the pressing means 40 is composed of an arc-shaped piece extending from the peripheral edge of the base portion 42 to one side in the axial direction.

As shown in FIG. 1 (b), the base portion 42 is housed inside the housing 4, and is rotatably supported by the support recess 32 of the shield member 12 about the central axis O. The center of the base 42 is aligned with the central axis O, and the radial center of the pressing means 40 is also aligned with the central axis O. Then, in the pressing means 40, when the input member 6 rotates, it comes into contact with one of the pair of restrained means 38, and the one contacted restrained means 38 is pushed in the winding direction of the coil spring 36 to be elastically deformed. As a result, one of the restrained means 38 in contact is moved away from the restraining means 24 to release the restraint by the restraining means 24.

As shown in FIGS. 2 and 3, the input member 6 has a columnar protrusion 44 that protrudes from one side surface of the base 42 to one side in the axial direction, and a circular protrusion 46 that protrudes from the tip surface of the protrusion 44 to one side in the axial direction. And a columnar connecting portion 48 projecting from the other side surface of the base portion 42 to the other side in the axial direction. The central axis of the protrusion 44, the central axis of the protrusion 46, and the central axis of the connecting portion 48 are all aligned with the central axis O. As shown in FIG. 1 (b), the protruding portion 44 is arranged inside the coil spring 36 in the radial direction. The protruding portion 44 has a cylindrical outer peripheral surface, and the outer diameter of the protruding portion 44 is smaller than the inner diameter of the coil spring 36 when both of the pair of restrained means 38 are restrained by the restraining means 24, and the protruding portion 44 There is a gap between the outer peripheral surface of the coil spring 36 and the inner peripheral surface of the coil spring 36. The connecting portion 48 passes through the support opening 30 of the shield member 12 and projects to the outside of the housing 4, and is rotatably supported by the support opening 30 about the central axis O. Further, a drive source (not shown) such as a motor is connected to the connecting portion 48.

The output member 8 may be formed of an appropriate metal material such as a steel material or an appropriate synthetic resin. As shown in FIGS. 2 and 3, the output member 8 includes a disk-shaped base portion 50, a columnar connecting portion 52 projecting from one side surface of the base portion 50 to one side in the axial direction, and an axial direction from the other side surface of the base portion 50. Includes a columnar mounted portion 54 projecting to the other side. The central axis of the base portion 50, the central axis of the connecting portion 52, and the central axis of the mounted portion 54 are all aligned with the central axis O.

As shown in FIG. 1 (b), the base portion 50 is housed inside the housing 4, and is rotatably supported by the support recess 20 of the housing body 10 about the central axis O. The connecting portion 52 passes through the support opening 18 of the housing body 10 and projects to the outside of the housing 4, and is rotatably supported by the support opening 18 about the central axis O. Further, a driven member (not shown) whose rotation is transmitted from the output member 8 is connected to the connecting portion 52.

As shown in FIG. 1B, the mounted portion 54 of the output member 8 is arranged inside the coil spring 36 in the radial direction and faces the protruding portion 44 of the input member 6 in the axial direction. The mounted portion 54 has a cylindrical outer peripheral surface. The outer diameter of the mounted portion 54 is the same as the outer diameter of the protruding portion 44, and is smaller than the inner diameter of the coil spring 36 when both of the pair of restrained means 38 are restrained by the restraining means 24. There is a gap between the outer peripheral surface of the 54 and the inner peripheral surface of the coil spring 36.

As shown in FIG. 3, a circular recess 56 into which the circular protrusion 46 of the input member 6 is rotatably inserted is formed on the tip surface of the mounted portion 54. By inserting the circular protrusion 46 into the circular recess 56, misalignment when the input member 6 and the output member 8 rotate is prevented. A circular protrusion is formed on the tip surface of the mounted portion 54 of the output member 8 so as to project in the axial direction about the central axis O, and a circular recess in which the circular protrusion of the output member 8 is rotatably inserted is an input member. It may be formed on the tip surface of the protrusion 44 of 6.

Next, the operation of the free type bidirectional clutch 2 as described above will be described with reference to FIGS. 1 and 5.

The right side of FIG. 1 (b) from the state shown in FIG. 1 in which the inner peripheral surface of the coil spring 36 is separated from the outer peripheral surface of the protruding portion 44 of the input member 6 and the outer peripheral surface of the mounted portion 54 of the output member 8. When the input member 6 rotates counterclockwise with respect to the central axis O, as shown in FIG. 5, one of the restrained means 38 (the upper restrained means 38 in FIG. 5) is a coil spring by the pressing means 40. The restraint by the restraint means 24 is released by being pushed in the winding direction of the 36 and elastically deforming. On the other hand, the other restrained means 38 (the lower restrained means 38 in FIG. 5) continues to be restrained by the restraining means 24 due to the frictional force generated between the arcuate portion 38a and the recess 24a. As a result, the coil spring 36 is twisted in the winding direction of the coil spring 36, so that the diameter of the coil spring 36 is reduced, and the outer peripheral surface of the protruding portion 44 of the input member 6 and the mounted portion of the output member 8 are reduced. The coil spring 36 is in close contact with the outer peripheral surface of the 54.

In a state where the coil spring 36 is in close contact with the projecting portion 44 and the mounted portion 54, the input member 6 further rotates around the central axis O counterclockwise when viewed from the right side of FIG. 1 (b), and one of them is constrained. When the means 38 is further pushed by the pressing means 40 in the winding direction of the coil spring 36, the restraint of the other restrained means 38 is released, and the input member is released via the coil spring 36 in close contact with the protruding portion 44 and the mounted portion 54. The rotation is transmitted from 6 to the output member 8. Further, even when the input member 6 is rotated to the other side in the circumferential direction, the input member 6 is input via the coil spring 36 which is in close contact with the protruding portion 44 and the mounted portion 54, as in the case where the input member 6 is rotated to one side in the circumferential direction. Rotation is transmitted from the member 6 to the output member 8.

On the other hand, in the free-type bidirectional clutch 2 of the illustrated embodiment, the output member 8 is mounted rather than the inner diameter of the coil spring 36 in a state where both of the pair of restrained means 38 are restrained by the restraining means 24 of the housing 4. Since the outer diameter of the portion 54 is small, when the output member 8 rotates, the output member 8 idles inside the coil spring 36 in the radial direction, and the rotation is not transmitted from the output member 8 to the input member 6.

As described above, the free-type bidirectional clutch 2 of the illustrated embodiment can be composed of the housing 4, the input member 6, the output member 8, and the coil spring 36, so that the number of parts can be further reduced.

In the free-type bidirectional clutch 2 of the illustrated embodiment, when the input member 6 rotates, the coil spring 36 comes into close contact not only with the mounted portion 54 of the output member 8 but also with the protruding portion 44 of the input member 6. The torque of the input member 6 is transmitted to the coil spring 36 not only from the pressing means 40 that pushes the restrained means 38 but also from the protruding portion 44 around which the coil spring 36 is wound. The concentration of the load on the restraining means 38 is suppressed, and the risk of damage to the restrained means 38 is reduced. Therefore, a relatively large torque can be transmitted from the input member 6 to the output member 8.

The free-type bidirectional clutch of the present invention is not limited to the above-described embodiment, and various modifications can be made from the above-described embodiment. For example, the outer peripheral surface of the peripheral wall 16 of the housing body 10 does not have to be cylindrical. Further, the restraining means formed on the inner peripheral surface of the peripheral surface wall 16 is not limited to the trochoidal tooth profile, and may be any one that can freely restrain the restrained means of the coil spring 36. For example, the inner peripheral surface of the peripheral wall 16 is formed on the satin surface over the entire circumferential direction, and the restrained means is freely restrained by the frictional force generated between the satin surface and the tip of the restrained means. You may be.

In the illustrated embodiment, the input member 6 is rotatably supported by the shield member 12, the output member 8 is rotatably supported by the housing body 10, but the input member 6 is rotatably supported by the housing body 10. , The output member 8 may be rotatably supported by the shield member 12.

The cross-sectional shape of the material (wire rod) of the coil spring 36 of the illustrated embodiment is rectangular, but may be circular. However, if the cross-sectional shape of the material of the coil spring 36 is rectangular, an axial gap (input member 6 and) that may be slightly formed between the protruding portion 44 of the input member 6 and the mounted portion 54 of the output member 8 (input member 6 and If the number of turns and the wire diameter are the same, the cross-sectional shape of the material of the coil spring 36 is circular as compared with the case where it becomes difficult to enter (a gap that may occur due to the dimensional tolerance of each of the output members 8). , The torque that can be transmitted from the input member 6 to the output member 8 becomes large.

2: Free type bidirectional clutch 4: Housing 6: Input member 8: Output member 24: Restraining means 24a: Concave part 24b: Convex part 36: Coil spring 38: Restrained means 38a: Arc-shaped part 40: Pressing means 42: Input member Base 44: Protruding part 46: Circular protrusion 54: Attached part 56: Circular recess O: Rotating shaft

Claims (5)

A housing fixed to be non-rotatable and an input member and an output member rotatably supported by the housing about a common central axis are provided, and the input member to the output member are in forward and reverse directions. A free-type bidirectional clutch in which the rotation of both of the above is transmitted, but when the output member rotates, the output member slips and the rotation is not transmitted from the output member to the input member.
The housing has a cylindrical inner peripheral surface, and a restraining means is formed on the inner peripheral surface.
A coil spring is housed in the housing, and a pair of restrained means extending toward the restraining means and freely restrained by the restraining means are formed at both ends of the coil spring in the axial direction, and the pair of restrained means is formed. The means are arranged at intervals in the circumferential direction from each other.
The input member includes pressing means facing the pair of restrained means in the circumferential direction.
The output member includes a mounted portion having a cylindrical outer peripheral surface arranged inside the coil spring in the radial direction, and the outer diameter of the mounted portion is such that both of the pair of restrained means are constrained by the restraining means. Smaller than the inner diameter of the coil spring in the closed state,
When the input member rotates to one side in the circumferential direction, one of the pair of restrained means is pushed by the pressing means in the winding direction of the coil spring and elastically deformed to release the restraint by the restraining means. As the other of the pair of restrained means continues to be restrained by the restraining means, the diameter of the coil spring is reduced and the coil spring is brought into close contact with the mounted portion.
When the input member further rotates to one side in the circumferential direction while the coil spring is in close contact with the mounted portion, and one of the pair of restrained means is further pushed by the pressing means in the winding direction of the coil spring. A free-type bidirectional clutch in which rotation is transmitted from the input member to the output member via the coil spring that is in close contact with the mounted portion. The free-type bidirectional clutch according to claim 1, wherein the input member includes a disk-shaped base portion, and the pressing means is composed of an arc-shaped piece extending axially from the peripheral edge of the base portion to one side in the axial direction. The input member has a disk-shaped base portion and a protruding portion that protrudes from one side surface of the base portion to one side in the axial direction and faces the mounted portion of the output member and is located inside the coil spring in the radial direction. Including
The protruding portion has a cylindrical outer peripheral surface, and the outer diameter of the protruding portion and the outer diameter of the mounted portion are the same.
The free-type bidirectional clutch according to claim 1, wherein the coil spring comes into close contact with the mounted portion and the protruding portion when the input member rotates. A circular protrusion that protrudes in the axial direction about the central axis is formed on one of the protruding portion of the input member and the mounted portion of the output member, and the protruding portion and the mounted portion are formed on the other side. The free type bidirectional clutch according to claim 3, wherein a circular recess into which the circular protrusion is rotatably inserted is formed. The restraining means of the housing is composed of a trochoidal tooth profile in which a plurality of concave portions and a plurality of convex portions are alternately arranged.
Each of the pair of constrained means of the coil spring comprises hooks extending outward from the axial end of the coil spring and then folded back in an arc.
The free type bidirectional clutch according to any one of claims 1 to 4, wherein the curvature of the arcuate portion of the pair of restrained means is larger than the curvature of the concave portion.

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