JP6419568B2 - Clutch unit - Google Patents

Description

  The present invention relates to a clutch unit having a function of switching between transmission and interruption of driving force from the input side to the output side, and a function of holding the position of the driven member on the output side when the driving force is not transmitted.

  In a device that operates a driven member by driving a motor, a spring clutch that uses the binding force of a coil spring may be used as one of means for switching between transmission and interruption of driving force from the input side to the output side.

  A general spring clutch has an input member that is rotationally driven in one direction by a drive motor and an output member that is connected to a driven member in the axial direction, and the outer periphery of the butted portion of both the input member and the output member. When a coil spring having a predetermined winding direction is arranged so as to wind, and the drive motor rotationally drives the input member in one direction, the coil spring contracts to bind the input member and the output member, and the drive force is applied to the output member. By transmitting one end side of the coil spring to the output member and fixing the other end side to the sleeve arranged radially outside the coil spring, and stopping the sleeve while the drive motor is driven. The coil spring is expanded in diameter so that the transmission of the driving force from the input member to the output member is blocked (see, for example, Patent Document 1).

JP-A-3-272323

  Since the spring clutch as described above transmits the driving force from the input member to the output member by the binding force of the coil spring, the driving force can be transmitted only in one direction determined by the winding direction of the coil spring, This is not possible when it is required to transmit the driving force in both rotational directions.

  Also, when the drive motor is stopped to stop the rotation of the output member without stopping the sleeve during transmission of the drive force from the input member to the output member, or when the drive motor stops due to a power failure or the like Since the output member can rotate freely, the driven member connected to the output member receives an external force such as gravity and changes its position (posture), which may cause various troubles.

  On the other hand, using a clutch unit that combines an electromagnetic clutch and an electromagnetic brake, when the drive motor is driven, the electromagnetic clutch is turned on and off to switch transmission and disconnection of the driving force from the input side to the output side, and turn on the electromagnetic brake.・ If the driven member is switched between the restrained state and the free state by turning OFF, the driving force can be transmitted in both rotation directions, and the electromagnetic brake is turned ON when the driving motor is stopped, and the position of the driven member is Can also be held.

  However, in the clutch unit that combines the electromagnetic clutch and the electromagnetic brake, the electromagnetic clutch and the electromagnetic brake are not turned on at the same time so that the electromagnetic clutch and the electromagnetic brake are not turned on at the same time while the drive motor is driven. There is a problem that it is necessary to accurately control the operation timing, which makes control difficult.

  Therefore, the present invention has a function of switching between transmission and interruption of the driving force in both rotational directions and a function of holding the position of the driven member when the driving force is not transmitted. It is an object of the present invention to provide a clutch unit that can be easily switched.

  In order to solve the above problems, the clutch unit of the present invention has an inner ring that rotates integrally with the output member disposed radially inside the outer ring that rotates integrally with the input member, and a cam surface that extends circumferentially on the outer peripheral surface of the inner ring. A plurality of wedge-shaped spaces gradually narrowing on both sides in the circumferential direction are formed between the inner peripheral cylindrical surface of the outer ring and the cam surfaces of the inner ring, and a pair of rollers and the rollers are arranged in each wedge-shaped space. A spring that pushes into the narrow portions on both sides of the wedge-shaped space one by one is incorporated, and the unlocking pieces having the column portions inserted on both sides in the circumferential direction of each wedge-shaped space are used as brake shafts that rotate around the same axis as the inner ring. The brake shaft is fixedly coupled to the electromagnetic brake, and a driving force for rotationally driving the input member is transmitted from the drive motor to the input member to the input side of the input member and applied to the input member via the outer ring. Reverse input When a reverse input blocking mechanism that locks against the torque and stops the input member and the outer ring is incorporated, and a driving force in any rotational direction is applied from the drive motor to the input member via the reverse input blocking mechanism However, when the electromagnetic brake is OFF, the outer ring that rotates integrally with the input member is locked to the inner ring via a roller on the front side in the rotation direction of the pair of rollers, thereby driving the inner ring and the output member. When the electromagnetic brake is on and the brake shaft and the unlocking piece are stopped, the roller on the front side in the rotation direction comes into contact with the column part of the unlocking piece and stops, and the outer ring and the inner ring are stopped. The locked state is released, and the outer ring and the input member are idled.

  According to the above configuration, transmission / cutoff of the driving force from the input side to the output side in both rotational directions can be switched by simply performing on / off control of the electromagnetic brake during driving of the driving motor. Even when an external force such as gravity received by the driven member is applied as a reverse input torque to the input member via the output member, the inner ring, the roller, and the outer ring, the input member and Since the outer ring is stopped, the inner ring and the output member can also be stopped to hold the position of the driven member.

  The reverse input blocking mechanism includes a worm gear to which a driving force is applied from the drive motor to the input member, and a worm wheel that meshes with the worm gear and is coupled to the input member so as to be able to transmit rotation. A worm mechanism having a self-locking function can be employed.

  In the clutch unit of the present invention, it is desirable to turn off the electromagnetic brake when the drive motor is stopped. This is because when the electromagnetic brake is turned on and the outer ring and the input member are idling while the drive motor is being driven, the locked state of the outer ring and the inner ring is released (each roller resists the elastic force of the spring). When the drive motor is stopped with the electromagnetic brake turned on, the inner ring locks with the outer ring (the stopped roller is a narrow part of the wedge-shaped space). The inner ring and the output member can be slightly rotated to change the position of the driven member when the driven member receives an external force. Because there is.

  That is, when the drive motor is stopped, the electromagnetic brake is turned off, and each roller is pushed into the narrow part of the wedge-shaped space by the elastic force of the spring to lock the outer ring and the inner ring. Even when an external force is applied, the position of the driven member can be reliably held by the action of the aforementioned reverse input blocking mechanism.

  As described above, the clutch unit of the present invention has an outer ring that rotates integrally with the input member when the driving force in any rotational direction is applied from the drive motor to the input member when the electromagnetic brake is OFF. The inner ring that rotates integrally with the inner ring and the driving force is transmitted to the inner ring and the output member, and when the electromagnetic brake is on, the unlocking piece integral with the brake shaft stops, so that the outer ring and the inner ring are locked. Since the outer ring and the input member are idled after being released, the ON / OFF control of the electromagnetic brake is only performed while the drive motor is driven, and the driving force in both rotational directions is changed from the input side to the output side. Transmission and interruption can be easily switched.

  In addition, since the reverse input blocking mechanism is incorporated between the drive motor and the input member, even when an external force acts on the driven member connected to the output member while the drive motor is stopped, the reverse input blocking mechanism The position of the driven member can be held by the locking operation.

Longitudinal front view of the clutch unit of the embodiment Sectional view along the line II-II in FIG.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. As shown in FIG. 1, the clutch unit includes a drive motor 1, an input gear (input member) 2 that is driven to rotate in both directions by the drive motor 1, and an output that meshes with a gear on the driven member (not shown). A gear (output member) 3, a clutch 4 for transmitting a driving force from the input gear 2 to the output gear 3, a brake shaft 5 passing through the clutch 4, an electromagnetic brake 6 coupled to the brake shaft 5, and a drive It is basically constituted by a worm mechanism 7 as a reverse input blocking mechanism provided between the motor 1 and the input gear 2, and is attached between a pair of fixed wall members 8.

  The input gear 2 is a helical gear (worm wheel) that constitutes a part of the worm mechanism 7 as will be described later, and the clutch 4 is incorporated inside from an opening on one end side in the axial direction. The opening is closed with a lid 9.

  The electromagnetic brake 6 has a friction plate 11 fitted and fixed to the brake shaft 5 in a case 10 attached to a wall member 8 on one end side (right side in FIG. 1) of the clutch unit, and a friction plate 11. A brake plate 12 supported so as to be able to contact and separate in the axial direction, a spring (not shown) for separating the brake plate 12 from the friction plate 11, and the brake plate 12 against the friction plate 11 against the elasticity of the spring when energized. It is an excitation type housing an electromagnet (not shown) to be pressed.

  Accordingly, during energization, the electromagnet presses the brake plate 12 against the friction plate 11 to turn on the friction plate 11 and the brake shaft 5 so that the brake is in an ON state. Is separated from the friction plate 11, the brake plate 11 and the brake shaft 5 are in a brake-off state in which the brake plate 5 and the brake shaft 5 can rotate freely.

  One end of the brake shaft 5 has a large diameter, one end thereof is rotatably supported by the case 10 of the electromagnetic brake 6, and the other end of the other end of the clutch unit via a sintered oil-impregnated bearing 13. The wall member 8 on the side (left side in FIG. 1) is rotatably supported. Further, the large-diameter portion is formed with a two-sided width portion 5a for connecting with the clutch 4 as described later on the other end side, and on the outer periphery of the portion inserted into the case 10 of the electromagnetic brake 6 The friction plate 11 is fitted and fixed.

  As shown in FIG. 1 and FIG. 2, the clutch 4 includes an outer ring 14 formed in a two-stage cylindrical shape, an inner ring 15 disposed radially inside a large diameter portion of the outer ring 14, and a large diameter of the outer ring 14. An unlocking piece 18 having a roller 16 and a coil spring 17 incorporated between the inner peripheral surface of the portion and the outer peripheral surface of the inner ring 15, and a column portion 18a inserted at a position facing the coil spring 17 across the roller 16. A side plate 19 is provided between the unlocking piece 18 and the lid 9 of the input gear 2 and attached to the outer ring 14.

  The outer ring 14 of the clutch 4 has a plurality of notches 14b formed in the outer peripheral portion of a flange portion 14a provided at one end, and a claw formed in the outer peripheral portion of the side plate 19 in a part of the notches 14b. The side plate 19 is fixed to the flange portion 14a by fitting and bending 19a. And the rotation prevention convex part 2a provided in the inner periphery of the input gear 2 is engage | inserted by the remaining notch 14b of the flange part 14a, and the notch 19b of the side plate 19 formed in the position corresponding to this, The outer ring 14 and the side plate 19 rotate integrally with the input gear 2.

  On the other hand, the inner ring 15 is inserted into a shaft hole 15a formed on one end side of the inner ring 15 so as to be connected to the small diameter portion of the large diameter portion of the brake shaft 5 and is braked on a hollow output shaft 20 formed integrally on the other end side. A small diameter portion of the shaft 5 is passed through and rotates around the same axis as the brake shaft 5. The output gear 3 is key-fixed on the outer periphery of the output shaft 20 so that the inner ring 15 and the output shaft 20 rotate integrally with the output gear 3. The output shaft 20 is rotatably supported by a sintered oil-impregnated bearing 21 fitted on the inner periphery of the small diameter portion of the outer ring 14.

  A plurality of cam surfaces 15b perpendicular to the radial direction are provided on the outer periphery of the inner ring 15, and a wedge shape that gradually narrows on both sides in the circumferential direction between the cam surfaces 15b and the inner peripheral cylindrical surface of the outer ring 14. A space 22 is formed. In each wedge-shaped space 22, a pair of rollers 16 are arranged with a coil spring 17 sandwiching the rollers 16 one by one into the narrow portion of the wedge-shaped space 22, and on each circumferential side of each wedge-shaped space 22. A column portion 18a of the unlocking piece 18 is inserted. The unlocking piece 18 is fitted and fixed to the outer periphery of the two-surface width portion 5a of the brake shaft 5 without a gap.

  In this clutch 4, when input torque (driving force) is applied to the outer ring 14 via the input gear 2, the roller 16 on the front side in the rotational direction is pushed into the narrow portion of the wedge-shaped space 22 by the elastic force of the coil spring 17. Thus, the outer ring 14 and the inner ring 15 are locked. At this time, if the lock release piece 18 is in a free state, the lock release piece 18 is pushed and moved even after the roller 16 on the front side in the rotation direction comes into contact with the column portion 18a of the lock release piece 18, and the outer ring 14 and the inner ring 15 are moved. Therefore, the rotation of the outer ring 14 is transmitted to the inner ring 15, the output shaft 20 and the output gear 3. At the same time, when the unlocking piece 18 is pushed by the roller 16 on the front side in the rotation direction, the brake shaft 5 and the friction plate 11 rotate together with the unlocking piece 18.

  On the other hand, if the unlocking piece 18 does not move, when the outer ring 14 and the inner ring 15 locked via the roller 16 on the front side in the rotation direction start to rotate together, the roller 16 on the front side in the rotation direction is unlocked. By abutting against the column 18a of 18 and stopping, it moves relative to the wide portion of the wedge-shaped space 22 against the elastic force of the coil spring 17, and the locked state of the outer ring 14 and the inner ring 15 is released and only the outer ring 14 is released. Becomes idle.

  The worm mechanism 7 includes a worm gear 23 that is connected to the main shaft 1 a of the drive motor 1 and directly receives a drive force from the drive motor 1, and an input gear 2 as a worm wheel that meshes with the worm gear 23. Have a self-locking function. That is, the input gear 2 is rotated by the driving force of the drive motor 1, but the input gear 2 and the outer ring 14 are stopped by locking against the reverse input torque applied to the input gear 2 via the outer ring 14 of the clutch 4. It is supposed to let you.

  This clutch unit has the above-described configuration, and when the driving force in any rotational direction is applied from the drive motor 1 to the input gear 2 via the worm mechanism 7, the brake shaft is turned off when the electromagnetic brake 6 is OFF. The unlocking piece 18 of the clutch 4 fixed to 5 becomes free, and the outer ring 14 of the clutch 4 that rotates integrally with the input gear 2 locks with the inner ring 15 that rotates integrally with the output gear 3. While the driving force is transmitted, when the electromagnetic brake 6 is ON, the lock release piece 18 stops (rotation is restricted), so that the locked state of the outer ring 14 and the inner ring 15 is released, and the outer ring 14 and the input are input. The gear 2 idles and transmission of the driving force to the inner ring 15 and the output gear 3 is interrupted.

  That is, transmission / cutoff of the driving force in both rotational directions from the input side to the output side can be switched only by performing ON / OFF control of the electromagnetic brake 6 while the drive motor 1 is being driven. Control is easier compared to a combination of electromagnetic brakes.

  Further, while the drive motor 1 is stopped, even if the driven member connected to the output gear 3 receives an external force such as gravity, the external force is transmitted from the inner ring 15 rotating integrally with the output gear 3 to the roller 16 and the outer ring 14. Therefore, the input gear 2 and the outer ring 14 remain stopped by the lock operation of the worm mechanism 7 incorporated between the drive motor 1 and the input gear 2, and the output is output. Each member on the side does not move, and the position (posture) of the driven member can be maintained.

  Here, the electromagnetic brake 6 is turned on during driving of the drive motor 1 to unlock the outer ring 14 and the inner ring 15 of the clutch 4, and after the transmission of the driving force to the output side is cut off, the drive motor 1 is stopped. In this case, it is desirable to turn off the electromagnetic brake 6 when the drive motor 1 is stopped.

  In this way, the roller 16 that was stopped when the electromagnetic brake 6 was ON (was in contact with the column portion 18a of the unlocking piece 18 and was positioned in the wide portion of the wedge-shaped space 22) is moved to the electromagnetic brake 6. Is turned OFF and the unlocking piece 18 becomes free, so that the outer ring 14 and the inner ring 15 are locked by the relative movement to the narrow portion of the wedge-shaped space 22 by the elastic force of the coil spring 17. Even when receiving an external force, the position of the driven member can be reliably held by the action of the worm mechanism 7 described above.

  When stopping the drive motor 1 during transmission of the driving force, the electromagnetic brake 6 is OFF, and the outer ring 14 and the inner ring 15 of the clutch 4 are locked. Therefore, it is necessary to control the electromagnetic brake 6. There is no.

  In the above-described embodiment, the worm mechanism is adopted as the reverse input blocking mechanism. However, the reverse input blocking mechanism transmits a high deceleration rate reduction mechanism having a self-locking function other than the worm mechanism and an input torque to the output side for output. It is also possible to employ a reverse input cut-off clutch that locks against reverse input torque applied to the side and cuts off torque transmission.

  Moreover, although the excitation type used the electromagnetic brake in embodiment, the non-excitation type electromagnetic brake can also be used depending on the apparatus in which a clutch unit is incorporated.

  Further, the helical gear formed integrally with the input member may be formed separately from the input member and connected to the input member so as to be able to transmit rotation.

  The present invention relates to a clutch unit having a function of switching between transmission and interruption of driving force in both rotational directions, but can also be applied to a clutch unit in which the rotational direction of the drive motor is limited to one direction. it can. In this case, the wedge-shaped space of the clutch is formed so as to be gradually narrowed on one side in the circumferential direction, and the structure can be simplified by using one roller incorporated in each wedge-shaped space.

1 Drive motor 2 Input gear (input member)
3 Output gear (output member)
4 Clutch 5 Brake shaft 6 Electromagnetic brake 7 Worm mechanism (reverse input blocking mechanism)
11 Friction plate 12 Brake plate 14 Outer ring 15 Inner ring 15b Cam surface 16 Roller 17 Coil spring 18 Unlocking piece 18a Column 19 Side plate 20 Output shaft 22 Wedge shaped space 23 Worm gear

Claims (3)

An inner ring that rotates integrally with the output member is arranged on the radially inner side of the outer ring that rotates integrally with the input member, and a plurality of cam surfaces are provided in the circumferential direction on the outer peripheral surface of the inner ring, and each of the inner peripheral cylindrical surface and the inner ring of the outer ring is provided. A wedge-shaped space that gradually narrows on both sides in the circumferential direction is formed between the cam surface and a pair of rollers and springs that push the rollers one by one into the narrow portions on both sides of the wedge-shaped space are incorporated in each wedge-shaped space, The lock release pieces having column portions inserted on both sides in the circumferential direction of each wedge-shaped space are fixed to a brake shaft that rotates around the same axis as the inner ring, and the brake shaft is connected to an electromagnetic brake.
A driving force for rotationally driving the input member is transmitted from the drive motor to the input member on the input side of the input member, and the input member is locked against a reverse input torque applied to the input member via the outer ring. And a reverse input blocking mechanism that stops the outer ring,
When the driving force in any rotational direction is applied from the drive motor to the input member via the reverse input blocking mechanism, the outer ring that rotates integrally with the input member is in the state of the pair of rollers when the electromagnetic brake is OFF. The driving force is transmitted to the inner ring and the output member by locking the inner ring via a roller on the front side in the rotation direction, and the brake shaft and the unlocking piece stop when the electromagnetic brake is on. The clutch unit is configured such that the roller on the front side in the rotation direction comes into contact with the column portion of the unlocking piece and stops so that the outer ring and the inner ring are unlocked and the outer ring and the input member are idled.   The reverse input blocking mechanism includes a worm gear to which a driving force is applied from the drive motor to the input member, and a worm wheel that meshes with the worm gear and is coupled to the input member so as to be able to transmit rotation, and has a self-locking function. The clutch unit according to claim 1, wherein the clutch unit has a worm mechanism.   The clutch unit according to claim 1 or 2, wherein the electromagnetic brake is turned off when the drive motor is stopped.

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