JP2015034630A - Assist mechanism - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the load torque of a motor of an assist mechanism having a reverse input block mechanism, and to simplify a structure of a main body side of a movable apparatus which is mounted with the assist mechanism.SOLUTION: A planetary gear device 2 as a differential device to which the torque of the power of a motor 1 and torque by man power are inputted is arranged in the middle of a drive passage of an assist mechanism which is mounted to a wheel chair as a movable apparatus, a torque sensor 4 for detecting the torque of the man power is added to the planetary gear device 2, thereby a structure of a main body side of the wheel chair can be simplified, a lock type reverse input block clutch 3 is employed as a reverse input block mechanism which is interposed between the motor 1 and the planetary gear device 2, and thereby the load torque of the motor 1 can be reduced compared with the case of employing an idle-type reverse input block clutch by an amount that there is no motion between a member rotating at the drive of the motor 1 and a fixed member.

Description

  The present invention relates to an assist mechanism that assists human power by driving a motor when a movable device is operated manually.

  In recent years, an assist mechanism that assists a human power for driving a movable device with a motor has been widely used in bicycles, wheelchairs, and the like. For example, in the wheelchair described in Patent Document 1, when driving a wheel by manually rotating a hand rim fixed to the wheel, a human torque applied to the hand rim is detected, and the motor is based on the detected value. It is equipped with an assist mechanism that assists human power by driving.

  By the way, the assist mechanism mounted on the wheelchair of Patent Document 1 transmits the input torque applied to the input side (motor side) to the output side (wheel side) in the middle of the drive path from the motor to the wheel, and outputs it. A mechanism (hereinafter referred to as “reverse input shut-off mechanism”) that prevents reverse input torque applied to the input side from being transmitted to the input side is provided, and when the motor is stopped due to a failure or the like, the wheel is driven only by human power. When this is done, torque transmission from the wheel to the motor is cut off so that the wheel can be driven with small human power.

  Here, as the reverse input blocking mechanism, the output side member (output shaft) is arranged concentrically with the input side member inside the input side member (input cylinder shaft) in the radial direction, and the outer peripheral surface of the output side member is cylindrical. A plurality of pockets (recesses) are provided on the inner peripheral surface of the input side member at a predetermined circumferential interval, and inclined cam surfaces are provided on both sides of each pocket in the circumferential direction so that a roller is accommodated in each pocket. Then, a cage (retainer) that holds each roller in a rollable manner is inserted between the inner peripheral surface of the input side member and the outer peripheral surface of the output side member, and between the cage and the input side member, A reverse input cutoff clutch in which a spring for centering the cage is provided at a neutral position where each roller does not lock with the input side member and the output side member, and the cage is slidably contacted with a seal member attached to a fixed member (body frame). Is adopted.

  In this reverse input cutoff clutch, when input torque is applied to the input side member, the cage that receives sliding resistance from the seal member relatively moves from the neutral position while elastically deforming the spring, so that the roller and the input side member Torque is transmitted to the output side member by locking with the output side member. On the other hand, when reverse input torque is applied to the output side member, the cage is returned to the neutral position by the force of the spring, and the lock between the input side member and the output side member of the roller is released. The member idles and torque is not transmitted to the input side member (hereinafter, the method of idling the output side member with respect to the reverse input torque is referred to as “idle type” hereinafter).

Japanese Patent No. 4262326

  In the wheelchair assist mechanism described in Patent Document 1, when the motor is driven, the reverse input blocking clutch roller is locked to the input side member and the output side member, and torque is transmitted to the wheel side. At this time, there is a problem that the load torque of the motor increases because the cage of the reverse input cutoff clutch, the cage that rotates integrally with the input side member and the output side member slides with the seal member on the fixed member side.

  In addition, in a wheelchair equipped with this assist mechanism, since human power is input from the hand rim to the wheel, it is necessary to provide a means for detecting the torque of the human power between the hand rim and the wheel, which complicates the structure on the main body side. There is also the problem of becoming.

  Accordingly, an object of the present invention is to reduce the load torque of a motor of an assist mechanism having a reverse input blocking mechanism and to simplify the structure of the main body side of a movable device on which the assist mechanism is mounted.

  In order to solve the above-described problems, the present invention provides an assist mechanism that assists a human power for driving a movable device with a motor, wherein the torque generated by the power of the motor and the torque generated by the human power are input, and the two inputs are combined into a single input. A differential device that converts it into a driving force and outputs it to the movable device, a reverse input blocking mechanism interposed between the motor and the differential device, and a magnitude of the torque of human power input to the differential device And a control device that drives the motor in response, the reverse input shut-off mechanism transmits torque generated by the power of the motor to the differential device, and with respect to the reverse input torque applied from the differential device. Is configured so that the reverse input torque is not transmitted to the motor.

  In other words, a differential device is provided in the middle of the drive path of the assist mechanism so that torque generated by the motor power is input and the driving force is output to the movable device. By attaching a means for detecting torque of human power to the differential device, the structure on the main body side of the movable device can be simplified, and the reverse input cutoff interposed between the motor and the differential device As a mechanism, torque generated by the motor power is transmitted to the differential device, and the reverse input torque applied from the differential device is locked, and the reverse input torque is not transmitted to the motor. By adopting the system, the amount of sliding movement between the member that rotates when the motor is driven and the fixed member is reduced as compared with the case where a conventional idling type reverse input blocking mechanism is used. Mo It had to be able to reduce the load torque of the motor.

  The reverse input blocking mechanism includes an input side member that receives torque generated by the power of the motor, an output side member that outputs torque generated by the power of the motor to the differential, and the output side member as a fixed member. Locking means for locking, unlocking means for releasing the locked state of the output side member and the fixing member by rotation of the input side member, and slight rotation of the input side member when the locked state is released A reverse input cutoff clutch provided with torque transmission means for transmitting to the output side member with an angle delay, a worm gear to which torque from the power of the motor is input, meshes with the worm gear, and is connected to the differential device. A worm mechanism having a self-locking function can be employed.

  The differential device includes a sun gear, an internal gear arranged radially outside the sun gear, and a plurality of planets that revolve around the sun gear while meshing with the sun gear and the internal gear. A gear and a carrier that rotatably supports the planetary gear, and the sun gear receives torque from the motor from the reverse input blocking mechanism, the carrier receives torque from the human power, A planetary gear device that outputs the rotation of the gear as a driving force to the movable device can be employed.

  Alternatively, as the differential device, two opposed bevel gears that are rotatably attached to the outer periphery of the fixed shaft, a pinion shaft that is rotatably attached to the outer periphery of the fixed shaft between the two opposed bevel gears, and the pinion An intermediate bevel gear which is rotatably attached to the outer periphery of the shaft and meshes with the opposite bevel gears, and the torque generated by the motor power from the reverse input blocking mechanism is applied to one of the opposite bevel gears; It is also possible to employ a differential gear device that receives the torque of the above and outputs it to the movable device using the rotation of the pinion shaft as a driving force.

  Here, a generator is connected to a member of the differential device that outputs a driving force to the movable device, and the control device brakes the movable device to the differential device while the movable device is coasting. When the power of the direction is inputted, the generator is operated, and when the torque of the human power becomes a predetermined value or less, the generator is stopped. The resulting braking force can reduce the burden of human power, and the power supply device for the assist mechanism can be charged to extend the usable time of the assist mechanism.

  Further, by modularizing the differential device, the reverse input blocking mechanism, and the control device, each module can be rearranged and can easily cope with various specifications.

  As described above, the assist mechanism of the present invention is provided with a differential device in which torque generated by motor power and torque generated by human power are input in the middle of the drive path, and is interposed between the motor and the differential device. As the reverse input blocking mechanism used is a lock type, it is possible to simplify the structure on the main body side of the movable device by attaching a means for detecting torque of human power to the differential device, and the reverse input blocking mechanism In this case, there is no sliding movement between the member that rotates when the motor is driven and the fixed member, and the load torque of the motor can be reduced.

Longitudinal front view of the assist mechanism of the first embodiment Sectional view along the line II-II in FIG. Sectional view along line III-III in FIG. 1 is a longitudinal front view of the modification of FIG. Longitudinal front view of the assist mechanism of the second embodiment Longitudinal front view of the assist mechanism of the third embodiment Longitudinal front view of the assist mechanism of the fourth embodiment

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. 1 to 3 show a first embodiment. This assist mechanism is mounted on a wheelchair as a movable device, and assists the human power for driving the wheel with a motor. As shown in FIG. 1, the torque generated by the power of the motor 1 and the torque generated by the human power are input. As a planetary gear device 2 as a differential device that converts the two inputs into one driving force and outputs it to the wheel of a wheelchair, and as a reverse input blocking mechanism interposed between the motor 1 and the planetary gear device 2 The reverse input cutoff clutch 3, the torque sensor 4 for detecting the torque of the human power input to the planetary gear device 2, the generator 5 connected to the output side of the planetary gear device 2, and the detected value of the torque sensor 4 And a control device 6 for controlling ON / OFF of the motor 1 and the generator 5 on the basis thereof.

  As shown in FIGS. 1 and 2, the planetary gear device 2 is disposed on a radially outer side of the sun gear 8 that is fitted and fixed to the outer periphery of the sun shaft 7. A ring gear 9 formed integrally, a plurality of planetary gears 10 revolving around the sun gear 8 while rotating in mesh with the sun gear 8 and the inner gear of the ring gear 9, and the planetary gear 10 are supported in a rotatable manner. A driving gear (which is provided with a carrier 11 to which torque by human power is input), the torque from the motor 1 is input to the sun gear 8 via the reverse input cutoff clutch 3, and the rotation of the ring gear 9 meshes with the outer gear. (Not shown) is output to the wheel as a driving force.

  The carrier 11 is formed integrally with a support shaft 11a that supports each planetary gear 10 and a central shaft 11b that is arranged concentrically with the sun shaft 7, and one end of the central shaft 11b is a carrier of the wheelchair body. The support part A is rotatably supported. A disc-shaped lid 12 that prevents the planetary gear 10 from coming off through the sun shaft 7 is attached to the tip of each support shaft 11a. An input gear 13 to which human power is input from a hand rim of a wheelchair is fitted and fixed to the outer periphery of the central shaft 11 b, and the torque sensor 4 is attached so as to be adjacent to the input gear 13.

  A power generation gear 14 that meshes with an external gear of the ring gear 9 is disposed outside the ring gear 9 in the radial direction at a position that does not interfere with the drive gear, and the generator 5 is connected to the power generation gear 14. ing.

  As shown in FIGS. 1 and 3, the reverse input cutoff clutch 3 is integrally formed with an input side member 15 to which torque by the power of the motor 1 is input and the sun shaft 7 of the planetary gear device 2. The output side member 16 that outputs torque by power, the two-stage cylindrical fixing member 17 fixed to the clutch support portion B of the wheelchair body, the outer peripheral surface of the large diameter portion of the output side member 16 and the large diameter of the fixing member 17 A roller 18 and a coil spring 19 are provided between the inner peripheral surface and the inner peripheral surface. A sintered oil-impregnated bearing 20 that rotatably supports the small-diameter portion of the output side member 16 is fitted into the inner periphery of the small-diameter portion of the fixing member 17.

  The input side member 15 is inserted in the engagement hole 16a of the output side member 16 at the front end side and is arranged concentrically with the output side member 16, and the input shaft 21 connected to the motor 1 at the rear end side, and an input It comprises a retainer 22 fitted and fixed to the outer periphery of the rear end side of the two-surface width portion 21a of the shaft 21. The cage 22 has a plurality of column portions 22 a inserted between the outer peripheral surface of the large diameter portion of the output side member 16 and the inner peripheral surface of the large diameter portion of the fixing member 17.

  The output side member 16 is opposed to the inner peripheral surface of the engagement hole 16a with the outer periphery on the front end side of the two-sided width portion 21a of the input shaft 21 with a slight rotational clearance, and has substantially the same cross-sectional shape. A two-sided width portion (not shown) is provided.

  In addition, a plurality of cam surfaces 16b whose inclinations are alternately reversed in the circumferential direction are provided on the outer periphery of the large-diameter portion of the output side member 16, and each of the cam surfaces 16b and the large-diameter portion of the fixing member 17 A wedge-shaped space 23 that is gradually narrowed on both sides in the circumferential direction is formed between the circumferential cylindrical surface. In each wedge-shaped space 23, a pair of rollers 18 is arranged with a coil spring 19 sandwiching the rollers 18 into the narrow portion of the wedge-shaped space 23, and both sides in the circumferential direction of each wedge-shaped space 23 (the rollers 18 The column portion 22a of the cage 22 is inserted at a position facing the coil spring 19 across the pin).

  The reverse input cutoff clutch 3 has the above-described configuration. Even when reverse input torque is applied from the planetary gear device 2 to the output side member 16, the roller 18 on the rear side in the rotation direction is wedge-shaped space by the elastic force of the coil spring 19. 23, the output side member 16 is locked to the fixing member 17 and the torque of the output side member 16 is not transmitted to the input side member 15 because the output side member 16 is engaged with the output side member 16 and the fixing member 17. .

  On the other hand, when an input torque is applied from the motor 1 to the input shaft 21 of the input side member 15, the column portion 22 a of the retainer 22 that rotates integrally with the input shaft 21 causes the roller 18 on the rear side in the rotation direction to move to the coil spring 19. The roller 18 is pushed to the wide part of the wedge-shaped space 23 against the elastic force of the roller, so that the engagement between the roller 18 and the output side member 16 and the fixing member 17 is released, and the locked state between the output side member 16 and the fixing member 17 is released. Is done. Then, when the input shaft 21 further rotates and the two-surface width portion 21 a engages with the two-surface width portion of the engagement hole 16 a of the output-side member 16, the rotation of the input shaft 21 is transmitted to the output-side member 16. Then, the sun shaft 7 and the sun gear 8 of the planetary gear device 2 rotate.

  That is, the reverse input cutoff clutch 3 includes a lock unit that locks the output side member 16 to the fixed member 17 and a lock release unit that releases the locked state between the output side member 16 and the fixed member 17 by the rotation of the input side member 15. And a torque transmission means for transmitting the rotation of the input side member 15 to the output side member 16 with a slight angular delay when the locked state is released.

  The control device 6 connects the electronic board 24 including a microcomputer to the motor 1, the torque sensor 4, the generator 5 and the power supply device (not shown) by a power / signal cable 25, and the motor 1 and It controls ON / OFF of the generator 5.

  Next, the operation of this assist mechanism will be described. When driving a wheelchair wheel from a stopped state, the hand rim of the wheelchair is first manually rotated, and the torque is input to the carrier 11 via the input gear 13 of the planetary gear unit 2 (at this time, the sun gear 8 is stopped). doing). Then, the torque sensor 4 detects the torque acting on the carrier 11, and when the detected value of the torque becomes a predetermined value or more, the control device 6 drives the motor 1. Torque due to the power of the motor 1 is transmitted from the input side member 15 of the reverse input cutoff clutch 3 to the output side member 16, and the sun shaft 7 of the planetary gear device 2 formed integrally with the output side member 16 rotates. Then, by rotating the sun gear 8 fitted and fixed to the sun shaft 7, the rotation of the planetary gear 10 is faster than the initial input of human power, and the rotation of the ring gear 9 is also faster, so that the wheels are driven with less human power. become able to.

  When the wheel is driven by the human power and the motor 1 as described above, when the input of the human power is stopped (when the torque detection value by the torque sensor 4 becomes smaller than a predetermined value), the control device 6 stops the motor 1. . Then, there is no input torque to the input side member 15 of the reverse input cutoff clutch 3, the output side member 16 is locked to the fixed member 17, and the sun shaft 7 and the sun gear 8 of the planetary gear device 2 are stopped. At this time, the ring gear 9, the planetary gear 10, the carrier 11, and the input gear 13 are rotated in the same direction as when driven by the coasting of the wheels, and the hand rim is also rotated accordingly.

  When braking is performed during wheel coasting, torque in the direction opposite to that during driving is applied to the hand rim by human power. Then, the torque sensor 4 detects the reverse torque input to the carrier 11 from the hand rim via the input gear 13, and the control device 6 turns on the switch of the generator 5 based on the signal. Then, when the generator 5 starts power generation, the rotation of the power generation gear 14 and the ring gear 9 meshing with the power generation gear 14 is slowed, and the burden of manpower required for braking is reduced. Thereafter, when the torque detected by the torque sensor 4 becomes smaller than a predetermined value, the control device 6 turns off the switch of the generator 5.

  As described above, the assist mechanism is provided with the planetary gear device 2 to which the torque generated by the power of the motor 1 and the torque generated by human power are input in the middle of the drive path, and detects the torque of the human power in the planetary gear device 2. Since the torque sensor 4 is provided, the structure on the main body side of the wheelchair can be simplified as compared with the case where the torque detection means is provided between the wheel rim and the wheel.

  Further, since the lock type reverse input cutoff clutch 3 is employed as the reverse input cutoff mechanism interposed between the motor 1 and the planetary gear device 2, the motor is compared with the case of using the idling type reverse input cutoff clutch. The load torque of the motor 1 can be reduced by the amount of sliding movement between the member that rotates during the driving and the fixed member.

  In addition, since the generator 5 connected to the output side of the planetary gear device 2 generates power during braking of the wheels, the burden of manpower can be reduced by the braking force obtained from the generator 5. Further, by connecting the generator 5 to the power supply device for the assist mechanism and using it as a regenerative brake, it is possible to charge the power supply device and extend the usable time of the assist mechanism.

  Further, by modularizing the planetary gear device 2, the reverse input cutoff clutch 3, and the control device 6, it becomes possible to rearrange each module and easily cope with various specifications.

  FIG. 4 shows a modification of the assist mechanism of the first embodiment described above. In this modification, a one-way clutch 26 is incorporated between the center shaft 11b of the carrier 11 of the planetary gear device 2 and the input gear 13, so that the input gear 13 does not rotate during wheel coasting. If it does in this way, rotation of the hand rim during wheel coasting can be prevented and safety can be improved. In this case, since it is not possible to input torque in the opposite direction to that during driving from the hand rim to the carrier 11, a separate braking signal is input to the control device 6, and the control device 6 controls the generator 5 based on the signal. What is necessary is just to set it as the structure which turns ON / OFF a switch.

  FIG. 5 shows a second embodiment. This embodiment is based on the first embodiment, adopts a differential gear device 27 as a differential device in place of the planetary gear device 2, and changes a part of the reverse input cutoff clutch 3 in accordance with this.

  The differential gear device 27 includes two opposing bevel gears 29 and 30 that are rotatably attached to the outer periphery of the fixed shaft 28, and a pinion that is rotatably attached to the outer periphery of the fixed shaft 28 between the two opposing bevel gears 29 and 30. A shaft 31, a plurality of intermediate bevel gears 32 that are rotatably attached to the outer periphery of the pinion shaft 31 and mesh with the opposing bevel gears 29, 30, and projecting portions at both ends of the pinion shaft 31 are axial grooves 33 a on the inner peripheral surface. And an output gear 33 that rotates together with the pinion shaft 31.

  Both ends of the fixed shaft 28 are supported by a fixed shaft support C of the wheelchair body (only one side is shown). One counter bevel gear 29 is provided with an external gear 29 a for inputting the power of the motor 1. The other counter bevel gear 30 is provided with a guide portion 30a for guiding the output gear 33 together with the external gear 29a of the one counter bevel gear 29, and a cylindrical shaft portion 30b extending toward the fixed shaft support portion C. The same input gear 13 and torque sensor 4 as those of the first embodiment are attached to the outer periphery of the cylindrical shaft portion 30b. The output gear 33 meshes with the drive gear (not shown) and the power generation gear 14 connected to the generator 5, similarly to the ring gear 9 of the first embodiment.

  On the other hand, the reverse input shut-off clutch 3 has an extension shaft portion 16c in which the output side member 16 replaces the sun shaft 7 of the planetary gear device 2 of the first embodiment. A coupling gear 34 that meshes with the external gear of the bevel gear 29 is fitted and fixed.

  In other words, in the second embodiment, torque due to the power of the motor 1 is input to one counter bevel gear 29 of the differential gear device 27 from the output side member 16 of the reverse input cutoff clutch 3 and input to the other counter bevel gear 30. Torque due to human power is input via the gear 13, and the rotation of the pinion shaft 31 is output to the wheelchair wheel as driving force via the output gear 33 and the driving gear.

  The operation of the assist mechanism of the second embodiment is almost the same as that of the first embodiment. That is, when torque is input from the hand rim to the other opposed bevel gear 30 through the input gear 13 by human power, the control device 6 drives the motor 1 based on the signal from the torque sensor 4. Then, the torque generated by the power of the motor 1 is transmitted to the one opposing bevel gear 29 via the reverse input cutoff clutch 3 and the connecting gear 34, and the rotation of the intermediate bevel gear 32 is faster than the initial input of human power due to the rotation. The revolution of the intermediate bevel gear 32, that is, the rotation of the pinion shaft 31 and the output gear 33 is also accelerated, and the wheels can be driven with a small human power.

  When the input of human power is stopped while the wheels are being driven, the control device 6 stops the motor 1, and one counter bevel gear 29 is stopped by the action of the reverse input cutoff clutch 3. At this time, the output gear 33, the pinion shaft 31, the intermediate bevel gear 32, the other opposing bevel gear 30 and the input gear 13 are rotated in the same direction as when driven by the coasting of the wheels, and the hand rim is also rotated accordingly. Then, when a torque in the direction opposite to that during driving is applied to the hand rim while the wheel is running, the generator 5 starts generating power, and the rotation of the power generation gear 14 and the output gear 33 meshing with it slows down for braking. The burden of human power required is reduced. Thereafter, when the reverse torque becomes smaller than a predetermined value, the generator 5 is stopped.

  Therefore, as in the first embodiment, the structure on the main body side of the wheelchair can be simplified as compared with the conventional one, the load torque of the motor 1 can be reduced, and the load of human power can be reduced by power generation of the generator 5 during braking. . Further, the differential gear device 27 can be modularized in the same manner as the planetary gear device 2 of the first embodiment, so that it can easily cope with various specifications.

  In each of the above-described embodiments, a lock-type reverse input cutoff clutch is used as a reverse input cutoff mechanism interposed between the motor and the differential, but a worm mechanism having a self-lock function is used instead. May be used.

  For example, the third embodiment shown in FIG. 6 is fitted and fixed to the outer periphery of the main shaft (not shown) of the motor 1 in place of the reverse input cutoff clutch 3 of the first embodiment, and torque by the power of the motor 1 is obtained. A worm mechanism 37 having an input worm gear 35 and a worm wheel 36 meshing with the worm gear 35 is used. The worm wheel 36 is fitted and fixed to the outer periphery of a connecting shaft 38 connected to the sun shaft 7 of the planetary gear device 2, and the connecting shaft 38 is connected to the clutch support portion B of the first embodiment via a bearing member 39. It is supported rotatably.

  When torque generated by the power of the motor 1 is input to the worm gear 35, the rotation of the worm gear 35 is decelerated and transmitted to the worm wheel 36, and the worm wheel 36 is connected to the connecting shaft 38, the sun shaft 7, and the sun gear 8. And rotate together. On the other hand, when reverse input torque is applied from the sun shaft 7 to the worm wheel 36 via the connecting shaft 38, the reverse input torque is not transmitted to the motor 1 by the self-lock function, and the sun shaft 7 and the sun gear 8 It comes to stop.

  Further, in the fourth embodiment shown in FIG. 7, the reverse input cutoff clutch 3 of the second embodiment is eliminated, and the same worm gear 35 as that of the third embodiment is fitted to the outer periphery of the main shaft (not shown) of the motor 1. In addition to fixing, on the outer periphery of one opposed bevel gear 29 of the differential gear device 27, a tooth 29b that meshes with the worm gear 35 instead of the external gear 29a is provided so that the one opposed bevel gear 29 also serves as a worm wheel. As a thing, the worm mechanism 40 is comprised. In the worm mechanism 40, as in the third embodiment, when torque generated by the power of the motor 1 is input to the worm gear 35, the torque is transmitted to one counter bevel gear 29, and one counter bevel gear is transmitted. When a reverse input torque is applied to 29, the reverse input torque is not transmitted to the motor 1 by the self-lock function.

  The present invention is not limited to an assist mechanism mounted on a wheelchair as in each of the above-described embodiments. For example, when operating a movable device by human power, such as that mounted on a bicycle, the motor is driven to reduce human power. The present invention can be widely applied to assisting assist mechanisms.

DESCRIPTION OF SYMBOLS 1 Motor 2 Planetary gear apparatus 3 Reverse input interruption | blocking clutch 4 Torque sensor 5 Generator 6 Control apparatus 7 Sun shaft 8 Sun gear 9 Ring gear 10 Planetary gear 11 Carrier 13 Input gear 15 Input side member 16 Output side member 17 Fixing member 18 Roller 19 Coil spring 21 Input shaft 22 Cage 26 One-way clutch 27 Differential gear device 28 Fixed shaft 29, 30 Opposite bevel gear 31 Pinion shaft 32 Intermediate bevel gear 33 Output gear 35 Worm gear 36 Worm wheel 37, 40 Worm mechanism

Claims (7)

In the assist mechanism that assists the human power to drive the movable device with a motor,
Torque due to the power of the motor and torque due to the human power are inputted, a differential device that converts the two inputs into one driving force and outputs it to the movable device, and between the motor and the differential device An interleaved reverse input blocking mechanism, and a control device that drives the motor according to the magnitude of human-power torque input to the differential device;
The reverse input shut-off mechanism transmits torque generated by the motor power to the differential device, locks against reverse input torque applied from the differential device, and does not transmit reverse input torque to the motor. Assist mechanism characterized by that.   The reverse input blocking mechanism includes an input side member that receives torque generated by the power of the motor, an output side member that outputs torque generated by the power of the motor to the differential device, and locks the output side member to a fixed member. A locking means for releasing, a lock releasing means for releasing the locked state between the output side member and the fixing member by rotation of the input side member, and a rotation of the input side member by a slight angle when the locked state is released. 2. The assist mechanism according to claim 1, wherein the assist mechanism is a reverse input cutoff clutch provided with torque transmission means that transmits the output side member with a delay. 3.   The reverse input blocking mechanism is a worm mechanism having a self-locking function, comprising a worm gear that receives torque generated by the power of the motor and a worm wheel that meshes with the worm gear and is connected to the differential device. The assist mechanism according to claim 1.   The differential gear is a sun gear, an internal gear arranged radially outside the sun gear, a plurality of planetary gears revolving around the sun gear while rotating in mesh with the sun gear and the internal gear; A carrier that rotatably supports the planetary gear, and the sun gear receives torque from the motor from the reverse input blocking mechanism, and the carrier receives torque from the human power, and the internal gear rotates. The assist mechanism according to any one of claims 1 to 3, wherein the assist mechanism is a planetary gear device that outputs the power to the movable device as a driving force.   Two differential bevel gears that are rotatably mounted on the outer periphery of the fixed shaft, a pinion shaft that is rotatably mounted on the outer periphery of the fixed shaft between the two counter bevel gears, and the pinion shaft An intermediate bevel gear that is rotatably attached to the outer periphery and meshes with the two opposite bevel gears. One of the two opposite bevel gears is torque generated by the motor from the reverse input blocking mechanism, and the other is torque generated by the human power. 4. The assist mechanism according to claim 1, wherein the assist mechanism is a differential gear device that outputs to the movable device using rotation of the pinion shaft as a driving force. 5.   A generator is connected to a member that outputs a driving force to the movable device among the differential devices, and the control device is in the direction of braking the movable device to the differential device while the movable device is coasting. The assist mechanism according to any one of claims 1 to 5, wherein the power generator is operated when the power is input, and the power generator is stopped when the torque of the human power becomes a predetermined value or less. .   7. The assist mechanism according to claim 1, wherein the differential device, the reverse input blocking mechanism, and the control device are respectively modularized.

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