JP2011126416A - Rear hub built-in transmission for power-assisted bicycle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To allow regenerative charging without complicating a device in a power-assisted bicycle of a center motor type including an internal transmission. <P>SOLUTION: A hub 1 of a driving wheel includes a shift mechanism 3 including a planetary gear mechanism, a one-way clutch 2 for reverse input, and a clutch switching device 9. The shift mechanism 3 has a sun gear 3a, and transmits driving force to a driving wheel through a sprocket 4. Also, the shift mechanism 3 includes a shift control mechanism 10 switching the sun gear 3a to be rotatable or non-rotatable around an axle 5 in response to the driving force to carry out shifting. The one-way clutch 2 for reverse input includes a one-way clutch claw 2a for reverse input provided on the sun gear 3a side and a clutch cam surface 2g for reverse input provided on the axle 5 side, and the sun gear is switched to be rotatable or non-rotatable around the axle 5 in response to reverse input by the clutch switching device 9. The clutch switching device 9 is constructed of a reverse input operation part 9a passing through the axle 5 with its one end being led out to the outside from the axle 5. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

    The present invention relates to a rear hub built-in transmission for an electrically assisted bicycle, which is used in an electrically assisted bicycle that adds an assist force to a human power drive system by an electric motor.

  A battery is mounted as a motor power source for applying an electric assisting force to an electric assisting bicycle that adds an assisting force to the human power drive system by an electric motor. Since it is desirable for this battery to be able to run for a long time with a single charge, a battery-assisted bicycle equipped with a function of charging the battery effectively by utilizing energy during self-running and regenerative power generation during the self-running Has been developed.

  As a battery charging device using regenerative power generation, for example, Patent Literature 1 discloses a technology of a regeneration control device that detects an operation of a brake lever and commands a regeneration operation to the regeneration device (see, for example, Patent Literature 1). ).

When this type of power regeneration function is installed, for example, as shown in Patent Document 2, in the case of a battery-assisted bicycle (hub motor system) in which a motor and a transmission are provided around the axle, the axle and the rotor of the motor are directly connected. Thus, power regeneration can be realized relatively easily (see, for example, Patent Document 2).
However, in the case of this hub motor system, the distance from the motor to the secondary battery tends to be long, and the wiring of the secondary battery tends to be complicated. Further, when the motor is disposed on the front axle, the operability is deteriorated, and when the motor is disposed on the rear side, there is a problem that it is difficult to achieve compatibility with the transmission.

  For this reason, when a power regeneration function is installed, if operability and simplification of the structure are desired, for example, as in Patent Document 3, a manual drive system including a crankshaft and its bearings, and auxiliary power by a motor are provided. It is advantageous to adopt a structure (center motor system) provided with a drive device in which a drive system to be combined with the crankshaft is housed in a single housing, a so-called center motor unit (see, for example, Patent Document 3).

For example, Patent Document 4 discloses a battery-assisted bicycle that is a center motor type and has a power regeneration function.
In this battery-assisted bicycle, a first one-way clutch is provided between the motor output shaft and the drive sprocket, a second one-way clutch is provided between the pedal crankshaft to which the pedal force is input and the drive sprocket, and further for brake operation. Accordingly, by providing direct coupling means for locking the first one-way clutch, power regeneration during braking is realized. The rear hub and the rear sprocket are directly connected so that reverse input torque from the tire can be transmitted to the motor during regeneration.

Similarly, for example, Patent Document 5 discloses a battery-assisted bicycle equipped with a power regeneration function.
In this battery-assisted bicycle, in the center motor unit, a two-way clutch capable of switching the lock direction in conjunction with the brake operation is provided on the output shaft of the motor to realize power regeneration during braking.

  That is, at the time of motor assist, by locking the two-way clutch in the forward rotation direction, the output of the motor can be transmitted to the axle, and motor assist becomes possible. In addition, if the two-way clutch lock direction is switched in conjunction with the occupant's brake operation and the two-way clutch is locked in the reverse rotation direction, the reverse input torque (forward rotation direction) from the axle side can be transmitted to the motor. This makes it possible to perform regenerative power generation and brake assist. In this configuration, since the reverse input torque from the axle side needs to be transmitted to the motor side during regeneration, the rear hub and the rear sprocket are directly connected.

JP-A-8-140212 JP 2003-166563 A Japanese Patent Laid-Open No. 10-250673 JP 2001-213383 A JP 2004-268843 A

  As described above, the battery-assisted bicycle can be roughly divided into a center motor system in which the motor is provided around the crankshaft and a hub motor system in which the motor is built in the front hub or the rear hub.

  In the hub motor system, it is necessary to incorporate a reduction gear in addition to the motor into the rear hub, but there is a problem that it is difficult to obtain a high reduction ratio in terms of space and a large torque cannot be obtained. In addition, since heavy objects are arranged at positions away from the center of gravity of the bicycle, there is a problem that maneuverability is poor, and wiring is complicated when the motor and the battery are separated. Furthermore, since the impact from the tire is directly transmitted to the speed reducer and the motor, there is a drawback that failure is likely to occur. For this reason, the center motor system is currently the mainstream.

  In the center motor type drive system, when the power regeneration function is installed, the rear hub and the rear sprocket are directly connected in Patent Document 4 and Patent Document 5 in order to transmit reverse input torque from the wheels to the motor shaft.

In this regard, a general bicycle speed change mechanism is a method in which a multistage sprocket is provided on the same axis of either the crankshaft or the rear axle or both, and the chain is moved between sprockets by a derailleur (exterior) There is a system (internal transmission) that changes gears by switching between a transmission and a gear provided inside the rear hub. A one-way clutch is usually provided in the internal transmission, and the reverse input from the tire is not transmitted from the rear hub to the rear sprocket.
The exterior transmission has a simple structure and is lightweight, but it causes wear of the sprocket and chain and also causes the chain to come off. On the other hand, internal transmissions are often used for city cycling because they are dustproof and waterproof and maintenance-free. At present, power-assisted bicycles are developed mainly for city cycle bicycles, most of which employ internal transmissions.

However, when the internal transmission is employed as described above, the reverse input from the wheels is not transmitted from the rear hub to the rear sprocket as it is. For this reason, the center motor cannot be rotated and regenerated by reverse input from the wheels.
In order to support reverse input, for example, it is possible to connect the axle to the crankshaft and the axle to the motor shaft with separate power transmission elements, but using two transmission elements is costly in terms of layout. In particular, the product value is greatly reduced.

  Accordingly, an object of the present invention is to enable regenerative charging without complicating the device as much as possible in a center motor type electrically assisted bicycle including an internal transmission.

In order to solve the above-described problems, the present invention attaches a secondary battery and an auxiliary drive motor to a frame connecting the front wheel and the rear wheel, and applies a pedaling force transmitted from the crankshaft or a driving force based on the output of the motor. Electric assistance used for a battery-assisted bicycle having a regenerative mechanism that can be transmitted to the driving wheel and that regenerates electric power generated by reverse input from the driving wheel to the output shaft of the motor during forward non-driving. In the bicycle rear hub internal transmission, the hub provided on the drive wheel includes a transmission mechanism, a reverse input one-way clutch, and a clutch switching device, and the transmission mechanism is constituted by a planetary gear mechanism, and includes at least one sun gear. And having a function of transmitting the pedaling force or the driving force generated by the output of the motor to the driving wheel through the sprocket, Relative power, provided with a shift control mechanism for shifting switch to the non rotatable or rotating the sun gear to the axle around,
The one-way clutch for reverse input is provided between at least one sun gear and an axle, the one-way clutch for reverse input is constituted by a ratchet clutch, and the one-way clutch for reverse input is driven by the clutch switching device. The sun gear has a function of switching to be rotatable or non-rotatable around the axle with respect to the reverse input from the reverse input, and the reverse input one-way clutch is a reverse input one-way provided on the sun gear. A clutch pawl and a reverse input clutch cam surface provided on an outer surface of the axle; and the clutch switching device has one end thereof drawn out from the axle through the axle and externally in the axial direction. A reverse input operation unit capable of moving operation is provided, and the reverse input operation unit is moved in the axial direction to perform the reverse input operation. The drive force from the sprocket is transmitted to the drive wheel through the speed change mechanism during driving, and when the forward drive is not driven, the reverse input is performed by operating the reverse input operation unit of the clutch switching device. A rear hub for a battery-assisted bicycle having a function of transmitting reverse input torque from the drive wheels to the sprocket by making the sun gear and the axle of the one-way clutch for rotation impossible to reverse input An internal gearbox was adopted.

With the above configuration, when driving forward, the driving force is transmitted from the sprocket of the driving wheel to the hub via the speed change mechanism, and the bicycle moves forward. During forward non-drive, the reverse input from the hub of the drive wheel is transmitted to the sprocket via the reverse input one-way clutch, and regenerative power generation is possible by transmitting torque from the sprocket to the motor driven sprocket through the power transmission element. It becomes. In addition, since the one-way clutch for reverse input always idles with respect to the driving force, the state of the clutch switching device is not limited during driving.
As described above, a one-way clutch for reverse input composed of a ratchet clutch, and a clutch switching device having a function of switching the ratchet clutch are arranged between the sun gear and the axle, thereby providing a center motor system having an internal transmission. In the rear hub built-in transmission for a power-assisted bicycle used in this type of power-assisted bicycle, transmission of driving force and transmission of reverse input can be realized without complicating the device.

  Further, the clutch switching device is configured such that the reverse input operation unit is pulled out through the axle and moved in the axial direction from the outside of the axle. With a simple configuration, it is possible to realize a function capable of switching the rotation or non-rotation of the sun gear relative to the axle of the reverse input one-way clutch. At this time, the reverse input clutch pawl of the ratchet clutch is arranged on the sun gear side and the reverse input clutch cam surface is provided on the axle side, so that the structure of the axle can be simplified.

  In this configuration, the clutch switching device includes a reverse input sleeve provided with a notch, and the notch is moved to the position of the reverse input clutch cam surface by moving the reverse input operation unit in the axial direction. And a position retracted from the reverse input clutch cam surface, and the movement can be employed to switch the reverse input one-way clutch.

  Further, in the configuration, the cutout portion of the reverse input sleeve may have a tapered portion at an axial end portion thereof. In place of or in addition to the above, the notch portion of the reverse input sleeve may have a tapered portion at a circumferential end thereof.

  In this way, by providing a tapered portion at the axial end of the notch, when the ratchet claw bitten into the cam surface comes into contact with one end of the notch, the ratchet claw is cammed by the inclined surface of the tapered portion. The force to remove from the surface can be increased. In addition, by providing a tapered portion at the circumferential end, the ratchet pawl moves on the cam surface along the inclined surface of the tapered portion during reverse rotation (in the reverse input clutch portion, rotation in the driving direction). Therefore, smooth rotation is possible.

  Here, the reverse input sleeve provided with the notch portion is provided so as to cover the reverse input clutch cam surface, and the reverse input sleeve can be moved in the axial direction through the axle. The reverse input operation unit can be slid in the axial direction. If the reverse input sleeve covers the reverse input clutch cam surface, the cam surface is normally closed, so that the ratchet pawl does not bite into the cam surface. When the forward input is not driven (reverse input from the tire), the reverse input operation unit is moved in the axial direction, so that the reverse input sleeve slides on the cam surface and the notch is positioned on the ratchet claw. The ratchet pawl can be engaged with the cam surface, the sun gear is locked against the reverse input, and the reverse input from the tire can be transmitted to the rear sprocket.

  The reverse input sleeve is fixed to the axle by a reverse input pin inserted in a reverse input lateral hole provided on the axle, and the reverse input pin is connected to the reverse input operation unit by the reverse input operation unit. It is possible to adopt a configuration in which the reverse input sleeve is moved in the axial direction by performing a movement operation in the axial direction within the horizontal hole.

  That is, in order to synchronize the axial movement operation of the reverse input operation unit and the movement of the reverse input sleeve, a horizontal hole that penetrates the axle is inserted, the pin is inserted into the horizontal hole, and the pin and the reverse input sleeve are fixed. Thus, the reverse input sleeve is moved by pushing the pin with the reverse input operation unit.

  At this time, if the configuration in which the reverse input sleeve is urged in the axial direction by the reverse input elastic member is adopted, for example, the reverse input operation unit pushes the pin in the axial direction by the reverse input elastic member. The reverse input sleeve can be returned to the original position by the elastic force of the reverse input elastic member by removing the external load (pressing force) to the operation portion by applying the reverse biasing force. .

  Note that the reverse input clutch switching mechanism can also be applied to a shift control mechanism. That is, in each of the above-described configurations, the speed change mechanism includes a speed change one-way clutch that switches the sun gear to be rotatable or non-rotatable around the axle, and the speed change one-way clutch is rotatable or non-rotatable with respect to the axle. Switching is performed by the shift control mechanism, and the shift one-way clutch includes a shift one-way clutch pawl provided on the sun gear, and a shift clutch cam surface provided on an outer surface of the axle. The structure which is a ratchet clutch provided with can be employ | adopted.

  Thus, the structure of the axle can be simplified by using a ratchet clutch mechanism for the one-way clutch for shifting, arranging the ratchet pawl on the sun gear side, and providing the shifting clutch cam surface on the axle side.

  The shift control mechanism can have the same structure as the clutch switching device. That is, the speed change control mechanism includes a speed change operation unit that passes through the axle and has one end pulled out from the axle and capable of moving in the axial direction from the outside. The shift one-way clutch can be switched by a moving operation.

  In addition, it is possible to provide unevenness on the axle having both functions of the reverse input clutch cam surface and the shift clutch cam surface, and in this respect, the structure can be simplified. Specifically, a plurality of irregularities are provided on the outer surface of the axle along the circumferential direction, and the irregularities can exhibit both functions of the reverse input clutch cam surface and the shift clutch cam surface. .

The speed change control mechanism includes a speed change sleeve provided with a notch, and the speed change operation part is moved in the axial direction so that the notch is positioned on the speed change clutch cam surface and the speed change clutch. It is possible to employ a configuration in which the one-way clutch for shifting is switched by moving to and from the position retracted from the cam surface. This is the same as in the case of the clutch switching device.

  Further, the notch portion of the speed change sleeve has a tapered portion at an axial end portion thereof, or instead of or in addition thereto, the notch portion of the speed change sleeve has a taper portion at a circumferential end portion thereof. The point which can employ | adopt the structure provided is also the same.

  The shifting sleeve is fixed to the axle by a shifting pin inserted in a shifting lateral hole provided on the axle, and the shifting pin is axially moved in the shifting lateral hole by the shifting operation portion. It is possible to adopt a configuration in which the shift sleeve is moved in the axial direction by a moving operation.

  The shift sleeve can employ a configuration in which it is biased in the axial direction by a shift elastic member.

In each of these configurations, for example, by disposing the reverse input sleeve and the speed change sleeve at positions that are relatively 90 ° out of phase, the two do not interfere with each other, and both mechanisms are established in a small space. It becomes possible to make it.
Specifically, the portion of the shift sleeve that covers the shift one-way clutch pawl and the portion of the reverse input sleeve that covers the reverse input one-way clutch pawl each have a shaft center of the axle. In this configuration, they are arranged on both sides and are arranged at positions that are 90 ° out of phase with each other around the axis of the axle.

According to these configurations, the shift control mechanism that controls the transmission device tends to have a longer moving stroke in the axial direction than the clutch switching mechanism that controls the one-way clutch for reverse input. This is because the transmission often includes a plurality of sun gears. Therefore, it is preferable to arrange the reverse input clutch switching mechanism on the rear sprocket side and the shift control mechanism on the reverse side.
That is, the specific configuration is that the sprocket is disposed closer to one axial direction in the hub case, the clutch switching device is disposed closer to one axial direction in the hub case, and the shift control mechanism is closer to the other. It is the arranged configuration.

  In each of these configurations, the clutch switching device adopts a configuration in which the sun gear and the axle can be switched between rotation and non-rotation in response to reverse input from the drive wheel in conjunction with a brake operation. be able to.

In the center motor unit, the motor output shaft and the motor drive sprocket can be directly connected to transmit the driving force and the torque in both directions of the reverse input. Also, the crankshaft and the crank sprocket (manpower driven sprocket) can be transmitted. ), A center one-way clutch that transmits only the driving force and idles during reverse input can be incorporated to prevent the pedal from forcibly rotating due to reverse input. That is, it is a center one-way clutch that locks in the direction in which the driving force is transmitted to the drive wheels and idles in response to reverse input from the drive wheels.
As this center one-way clutch, a roller clutch, a sprag clutch, a ratchet clutch, or the like can be employed.

According to the present invention, regenerative energy can be stored in the secondary battery, and the cruising distance per charge can be greatly extended as compared with the case where regenerative charging is not performed. Moreover, the current battery-assisted bicycle with a regenerative function has a heavy motor arranged in the front or rear hub, but according to the present invention, the motor can be arranged near the crankshaft near the center of gravity. Good maneuverability of the entire bicycle. In addition, since the speed change mechanism is provided, less pedaling force is required at the start, the balance is not easily lost, the assist power can be saved, and the cruising distance is further extended. Since the speed change mechanism is built in the hub, it is highly durable and maintenance-free. Furthermore, the reverse input one-way clutch can be arranged on the axle fixed to the frame by providing the reverse input one-way clutch between the sun gear and the axle.
That is, by disposing the one-way clutch for reverse input between the sun gear and the axle, in the center-motor-type battery-assisted bicycle equipped with the internal transmission, the driving force transmission is reversed without complicating the device. Input transmission can be realized.

  Further, the clutch switching device is configured such that the reverse input operation unit is pulled out through the axle and moved in the axial direction from the outside of the axle. With a simple configuration, it is possible to realize a function capable of switching the rotation or non-rotation of the sun gear relative to the axle of the reverse input one-way clutch. At this time, the reverse input clutch pawl of the ratchet clutch is arranged on the sun gear side and the reverse input clutch cam surface is provided on the axle side, so that the structure of the axle can be simplified.

Front view showing driving (direct connection) of the embodiment (A) is AA sectional drawing of FIG. 1, (b) is BB sectional drawing of FIG. The front view which shows the time of driving (at the time of 1st speed increase) of embodiment (A) is AA sectional drawing of FIG. 3, (b) is BB sectional drawing of FIG. Front view showing driving of the embodiment (at the second speed increase) (A) is AA sectional drawing of FIG. 5, (b) is BB sectional drawing of FIG. The front view which shows the state (shift is a 2nd stage) which can transmit reverse input torque in embodiment (A) is AA sectional drawing of FIG. 7, (b) is BB sectional drawing of FIG.

  An embodiment of the present invention will be described with reference to FIGS. The battery-assisted bicycle of this embodiment has a center motor system in which a secondary battery and an auxiliary drive motor (center motor unit) are attached to a frame connecting the front wheel and the rear wheel in the vicinity of the center between the front wheel and the rear wheel. It is.

  When driving, that is, when the pedaling force transmitted from the crankshaft through the pedal or the driving force by the output of the motor is input, the crank sprocket of the center motor unit (not shown) and the rear sprocket of the rear wheel as the driving wheel ( The driving force can be transmitted to the rear wheel via a power transmission element such as a chain connecting the sprocket 4. Further, a regenerative mechanism is provided that reduces regenerative power generated by reverse input from the rear wheel rear hub 1 to the output shaft of the motor to the secondary battery of the center motor unit during forward non-drive.

  As shown in FIG. 1, the rear hub 1 includes a speed change mechanism 3 and a reverse input one-way clutch 2 for reverse input transmission in a hub case 7 provided coaxially with the rear axle 5. The reverse input one-way clutch 2 is constituted by a ratchet clutch. 1, 3, 5, and 7, the upper side from the central axis is a sectional view of the transmission clutch, and the lower side is a sectional view of the reverse input clutch.

The speed change mechanism 3 is constituted by a planetary gear mechanism capable of a total of three speeds including direct connection and two speeds. The configuration is such that two sun gears 3a (referred to as a first sun gear 3a-1 and a second sun gear 3a-2) provided on the outer periphery of the axle 5 respectively correspond to a shift one-way clutch 3e (second gear). It can be connected to the axle 5 via a one-way clutch 3e-1 and a third one-way clutch 3e-2.
In the second one-way clutch 3e-1 and the third one-way clutch 3e-2, the transmission one-way clutch pawl 3g is engaged with or disengaged from the transmission clutch cam surface 3f provided on the outer periphery of the axle 5, respectively. It is supposed to work.

  In this embodiment, the second one-way clutch 3e-1 and the third one-way clutch 3e-2 employ ratchet clutches.

  The transmission mechanism 3 includes a planetary gear 3b having two gears meshed with the first sun gear 3a-1, the second sun gear 3a-2, the planet carrier 3c holding the planetary gear 3b, and A hub case 7 integral with an outer ring gear meshing with the planetary gear 3 b and a first one-way clutch 8 provided between the planet carrier 3 c and the hub case 7 are provided. In this embodiment, the outer ring gear is formed integrally with the hub case 7, but it is also conceivable that the outer ring gear and the hub case 7 are formed separately and meshed so as to rotate together.

  In this embodiment, as shown in FIG. 1, the first one-way clutch 8 employs a ratchet clutch, and the clutch pawl provided in the ratchet clutch is used when the planetary carrier 3c and the hub case 7 rotate relative to each other in one direction. In addition, the engagement between the outer periphery of the planet carrier 3c and the inner periphery of the hub case 7 is released when the rotation relative to the other direction. The first one-way clutch 8 may be a one-way clutch having another configuration such as a roller clutch or a sprag clutch.

Further, bearing portions 11 and 12 are provided between the planet carrier 3c and the axle 5 and between the hub case 7 and the axle 5, respectively. The bearing portions 11 and 12 support the planet carrier 3c and the axle 5 and the hub case 7 and the axle 5 so as to be relatively rotatable.
A bearing portion 13 is also provided between the planet carrier 3 c and the hub case 7. The planetary carrier 3c, the hub case 7 and the axle 5 are supported by the bearing portion 13 so as to be relatively rotatable.

  The first sun gear 3a-1 and the second sun gear 3a-2 are operated by operating the shift control mechanism 10 with the second one-way clutch 3e-1 and the third one-way clutch 3e-2, respectively. Either one can be selectively fixed to the axle 5 or all can be free.

  For example, when the driving force is transmitted from the rear sprocket 4 when the first sun gear 3a-1 and the second sun gear 3a-2 are both free with respect to the axle 5, the planetary gear mechanism Is not directly involved in the acceleration of the driving force, and the driving force is directly transmitted from the planetary carrier 3c to the hub case 7 via the first one-way clutch 8 (directly connected state). In this case, the rotational speed from the rear sprocket 4 is transmitted to the hub case 7 without being shifted.

Further, when the first sun gear 3a-1 is fixed to the axle 5, when the number of teeth of the first sun gear 3a-1 is a and the number of teeth of the outer ring gear is d, the increase from the planet carrier 3c to the outer ring gear is increased. The speed ratio is (a + d) / d
It becomes. At this time, the second sun gear 3a-2 is idling and does not participate in torque transmission.

Further, when the second sun gear 3a-2 is fixed to the axle 5, the number of teeth of the second sun gear 3a-2 is a, the number of teeth of the planetary gear 3b meshing with the first sun gear 3a-1 is b, When the number of teeth of the planetary gear 3b meshing with the two sun gears 3a-2 is c and the number of teeth of the outer ring gear is d, the speed increasing ratio from the planet carrier 3c to the outer ring gear is [(a × b) / (c × d)] + 1.
At this time, the first sun gear 3a is in an idling state and does not participate in torque transmission.

  That is, the sun gears 3a-1 and 3a-2 have different numbers of teeth, and all the gears are free, or either one is fixed to the axle 5 to change the speed increasing ratio. it can.

  The reverse input one-way clutch 2 has a reverse input clutch pawl 2a on the inner periphery of the first sun gear 3a-1, and the reverse input clutch pawl 2a is elastically moved by an elastic member 2h. The reverse input clutch cam surface 2g provided on the axle 5 side is urged in a rising direction.

  The speed change one-way clutch 3e has a speed change one-way clutch pawl 3g on the inner periphery of the first sun gear 3a-1 and the second sun gear 3a-2, and the speed change one-way clutch pawl 3g is also elastic. One end of the member 3h is biased in the direction of rising toward the shift clutch cam surface 3f provided on the axle 5 side.

  In this embodiment, a part of the reverse input clutch cam surface 2g and the shift clutch cam surface 3f are shared. That is, the second one-way clutch 3e-1 and the reverse input one-way clutch 2 are arranged at substantially the same position with respect to the axial direction of the axle 5. The outer surface of the axle 5 corresponds to the reverse input one-way clutch 2. A bidirectional clutch cam surface 14 having both functions of the reverse input clutch cam surface 2g and the shift clutch cam surface 3f corresponding to the second one-way clutch 3e-1 is provided (see FIG. 2B). .

  The shift clutch cam surface 3f corresponding to the second one-way clutch 3e-1 is provided on the outer surface of the axle 5 so as to function alone (see FIG. 2 (a)).

  The one-way clutch 2 for reverse input has a function that allows the first sun gear 3a-1 to be switched around the axle 5 or not to rotate with respect to the reverse input from the drive wheel by the clutch switching device 9. is doing.

  The configuration of the clutch switching device 9 includes a reverse input operation unit 9a that passes through the shaft hole 5a of the axle 5 and is pulled out from the axle 5 to the outside and can be operated in the axial direction from the outside. ing. The reverse input one-way clutch 2 can be switched by operating the reverse input operation portion 9a to move in the axial direction.

  The clutch switching device 9 includes a reverse input sleeve 9b provided with a notch 9e formed of an opening having a certain length in the axial direction and a certain length in the circumferential direction.

  By operating the reverse input operation portion 9a to move in the axial direction, the notch 9e moves between the position of the reverse input clutch cam surface 2g and the position retracted from the reverse input clutch cam surface 2g. be able to. The reverse input one-way clutch 2 is switched by the movement. If the notch portion 9e faces the reverse input clutch cam surface 2g, the reverse input clutch pawl 2a enters the notch portion 9e by the urging force of the elastic member 2h, and one end thereof is on the axle 5 side. Engages with the reverse input clutch cam surface 2g. If the notch 9e is retracted from the position corresponding to the reverse input clutch cam surface 2g, the reverse input clutch pawl 2a is engaged with the reverse input clutch cam surface 2g by the reverse input sleeve 9b. Be blocked.

The notch portion 9e of the reverse input sleeve 9b has a tapered portion 9d at its axial end and a tapered portion at its circumferential end.
Thus, by providing the taper portion 9d at the axial end of the notch portion 9e, when the edge of the notch portion 9e comes into contact with the reverse input clutch pawl 2a engaged with the reverse input clutch cam surface 2g. The inclined surface of the taper portion can increase the force for removing the reverse input clutch pawl 2a from the reverse input clutch cam surface 2g.
Also, by providing a tapered portion at the circumferential end, the reverse input clutch pawl 2a cams along the inclined surface of the tapered portion during reverse rotation (in the reverse input clutch portion, rotation in the driving direction). Smooth movement is possible because it moves on the surface.

  As shown in FIG. 1, the reverse input sleeve 9 b is fixed to the axle 5 by a reverse input pin 9 f inserted in a reverse input lateral hole 9 g provided in the axle 5. The reverse input sleeve 9b can be moved in the axial direction by moving the reverse input pin 9f in the axial direction within the reverse input horizontal hole 9g by the reverse input operation portion 9a. The reverse input sleeve 9b is urged in the axial direction by the reverse input elastic member 9c.

  Next, the structure of the speed change control mechanism 10 includes a speed change operation portion that passes through the shaft hole 5a of the axle 5 and has one end pulled out from the axle 5 to the outside and can be operated in the axial direction from the outside. 10a. The speed change operation unit 10a is pulled out to the end of the axle 5 on the side opposite to the side from which the reverse input operation unit 9a is pulled out. The shifting one-way clutch 3e can be switched by moving the shifting operation portion 10a in the axial direction.

  The speed change control mechanism 10 includes a speed change sleeve 10b provided with a notch 10e formed of an opening having a constant length in the axial direction and a constant length in the circumferential direction.

  By operating the shift operation portion 10a to move in the axial direction, the cutout portion 10e can move between the position of the shift clutch cam surface 3f and the position retracted from the shift clutch cam surface 3f. . The notch 10e is provided corresponding to the second one-way clutch 3e-1 and the third one-way clutch 3e-2 in parallel in the axial direction, and the notches 10e-1, Depending on the position of 10e-2, either one of the first sun gear 3a-1 and the second sun gear 3a-2 is selectively fixed to the axle 5, or all are switched to a free state.

  The notch 10e faces only the shifting clutch cam surface 3f of either the second one-way clutch 3e-1 or the third one-way clutch 3e-2, so that the shifting clutch pawl 3g on the facing side is an elastic member. The urging force of 3h enters the notch 10e and one end thereof engages with the shift clutch cam surface 3f on the axle 5 side. The notch portions 10e-1 and 10e-2 aligned in the axial direction are arranged so that the notch portion 10e does not simultaneously face the shifting clutch cam surface 3f of the second one-way clutch 3e-1 and the third one-way clutch 3e-2. Since the interval is determined, the shifting clutch pawl 3g on the side where the notch 10e does not face is prevented from engaging the shifting clutch cam surface 3f by the shifting sleeve 10b.

Further, the notch 10e of the speed change sleeve 10b includes a tapered portion 10d at an end portion in the axial direction and a tapered portion at an end portion in the circumferential direction.
Thus, by providing the taper portion 10d at the axial end of the notch portion 10e, when the shift clutch pawl 3g engaged with the shift clutch cam surface 3f contacts the edge of the notch portion 10e, The inclined surface of the tapered portion 10d can increase the force for removing the shift clutch pawl 3g from the shift clutch cam surface 3f.
Further, by providing a tapered portion at the circumferential end, the shift clutch pawl 3g is cam surface along the inclined surface of the taper portion when rotating in the reverse direction (in the shift clutch portion, rotating in the reverse input direction). Smooth movement is possible because it moves up.

  As shown in FIG. 1, the speed change sleeve 10 b is fixed to the axle 5 by a speed change pin 10 f inserted into a speed change horizontal hole 10 g provided on the axle 5. The shifting sleeve 10b can be moved in the axial direction by moving the shifting pin 10f in the axial direction within the shifting lateral hole 10g by the shifting operation portion 10a. The transmission sleeve 10b is urged in the axial direction by the transmission elastic member 10c.

  In this embodiment, as shown in FIG. 2 (b), a portion of the shift sleeve 10b that covers the shift one-way clutch pawl 3g and a reverse input one-way clutch pawl 2a of the reverse input sleeve 9b are covered. The portions are respectively disposed on both sides of the axle 5 and are disposed at positions that are 90 ° out of phase with each other around the axle 5. That is, in the cross section orthogonal to the axis shown in FIG. 2B, the reverse input sleeve 9b and the shift sleeve 10b appear alternately every 90 °. For this reason, both do not interfere and both mechanisms can be established in a small space.

  With these configurations, during driving, the driving force from the sprocket 4 is transmitted to the driving wheel through the speed change mechanism 3, and during forward non-driving, the reverse input is performed by operating the reverse input operation unit 9 a of the clutch switching device 9. By making the sun gear and the axle 5 in the one-way clutch 2 non-rotatable with respect to the reverse input, the function of transmitting the reverse input torque from the drive wheel to the sprocket 4 can be exhibited.

  More specifically, FIG. 1 and FIG. 2 show the state of the first gear stage (directly connected state). The rear sprocket 4 is provided in the hub case 7 on the one side in the axial direction. The reverse input clutch switching mechanism 9 is arranged on the rear sprocket side, and the shift control mechanism 10 is arranged on the reverse side.

Of the one-way clutch 3e for shifting, the shifting clutch pawl 3g of the second one-way clutch 3e-1 and the shifting clutch pawl 3g of the third one-way clutch 3e-2 are provided by the reverse input sleeve 9b and the shifting sleeve 10b. It is separated from the bidirectional clutch cam surface 14.
For this reason, the first sun gear 3 a-1 and the second sun gear 3 a-2 can rotate relative to the axle 5 with respect to the driving force from the rear sprocket 4. Therefore, the driving force is transmitted from the rear sprocket 4 in the order of the planet carrier 3 c, the first one-way clutch 8, and the hub case 7.

The state of the second speed change (speed increase 1) is shown in FIGS. As shown in FIG. 3, the speed change sleeve 10b slides in the axial direction by pushing the speed change operating portion 10a of the speed change control mechanism 10 to a predetermined position in the axial direction by an external operation, and the speed change second one-way clutch 3e. The shift notch 10e of the shift sleeve 10b moves to the position of the shift clutch pawl 3g.
As a result, as shown in FIG. 4B, the shifting clutch pawl 3g of the shifting second one-way clutch 3e-1 is engaged with the shifting clutch cam surface 3f (bidirectional clutch cam surface 14), and the first sun. The gear 3a-1 is locked to the axle 5 with respect to the driving force.

  At this time, the reverse input one-way clutch pawl 2a of the reverse input one-way clutch 2 is prevented from being engaged with the reverse input clutch cam surface 2g (the bidirectional clutch cam surface 14) by the reverse input sleeve 9b. ing.

  Further, as shown in FIG. 4A, at the position of the shift clutch pawl 3g of the third one-way clutch 3e-2, the two-way clutch cam surface 14 and the shift first shift gear are shifted by the reverse input sleeve 9b and the shift sleeve 10b. The shifting clutch pawl 3g of the three one-way clutch 3e-2 is separated. For this reason, the second sun gear 3 a-2 is rotatable around the axle 5.

  In this state, the driving force from the rear sprocket 4 is the speed increasing ratio (a + d) / d, where a is the number of teeth of the first sun gear 3a-1 and d is the number of teeth of the outer ring gear provided on the hub case 7. It is transmitted to the hub case 7.

  The state of the third speed change (speed increase 2) is shown in FIGS. As shown in FIG. 5, the speed change sleeve 10b slides in the axial direction by pushing the speed change operating portion 10a of the speed change control mechanism 10 to a predetermined position in the axial direction by external operation, and the third one-way clutch 3e-2 The notch 10e of the shift sleeve 10b moves to the position of the shift clutch pawl 3g.

  Thereby, the shifting clutch pawl 3g of the third one-way clutch 3e-2 is engaged with the bidirectional clutch cam surface 14, and the second sun gear 3a-2 is locked to the axle 5 with respect to the driving force.

  At this time, at the position of the shifting clutch pawl 3g of the second one-way clutch 3e-1, the shifting clutch pawl of the two-way clutch cam surface 14 and the second one-way clutch 3e-1 is driven by the reverse input sleeve 9b and the shifting sleeve 10b. It is separated from 3g. For this reason, the first sun gear 3 a-1 can rotate around the axle 5.

  In this state, the driving force from the rear sprocket 4 is such that the number of teeth of the second sun gear 3a-2 is a, the number of teeth of the planetary gear 3b meshing with the first sun gear 3a-1 is b, and the second sun gear 3a- 2 is transmitted to the hub case 7 at a speed increasing ratio [(a × b) / (c × d)] + 1 where c is the number of teeth of the planetary gear 3b meshing with 2 and d is the number of teeth of the outer ring gear.

  When returning from the third speed to the second speed, or returning from the second speed to the first speed, the load (pressing force) applied to the speed change operation unit 10a is released or reduced, thereby changing the speed. The speed change sleeve 10b is pushed back by the elastic member 10c. At this time, the taper portion 10d provided at the axial end of the notch portion 10e increases the force for pushing up the one-way clutch pawl 3g that is engaged with the two-way clutch cam surface 14, and the shift sleeve 10b is easily returned. Therefore, smooth switching is possible.

  FIGS. 7 and 8 show a state in which the reverse input one-way clutch 2 is locked when the vehicle is not driven forward (at the time of reverse input from the tire). The rotation directions of the sun gears 3a-1 and 3a-2 with respect to the axle 5 are opposite to those when the driving force is applied. At this time, when the reverse input operation portion 9a of the clutch switching device 9 is pushed in the axial direction by an external operation, the reverse input sleeve 9b slides in the axial direction, and the reverse input one-way clutch pawl 2a of the reverse input one-way clutch 2 is moved. The notch 9e of the reverse input sleeve 9b moves to the position.

Thus, the reverse input one-way clutch pawl 2a of the reverse input one-way clutch 2 is engaged with the reverse input clutch cam surface 2g (two-way clutch cam surface 14), and the first sun gear 3a-1 is an axle for the reverse input. Locked to 5.
The reverse input from the tire is transmitted from the hub case 7 to the rear sprocket 4 at a reduction ratio (a + d) / d, where a is the number of teeth of the first sun gear 3a-1 and d is the number of teeth of the outer ring gear.

  FIG. 7 shows the state of the second gear stage with respect to the transmission mechanism 3, but the first sun gear 3a-1 is locked to the axle 5 with respect to the reverse input at any gear stage. Therefore, the reverse input transmission path from the tire is constant.

  The movement of the reverse input operation unit 9a in the axial direction is preferably interlocked with the brake operation. That is, when the brake is operated, the reverse input operation unit 9a moves in the axial direction (right side in the figure), and the first sun gear 3a-1 is connected to the axle via the reverse input one-way clutch 2 with respect to the reverse input. The reverse input torque from the tire is transmitted to the rear sprocket 4.

When the brake is released, the reverse input operation unit 9a tries to move to the original position by the urging force of the reverse input elastic member 9c.
However, when the reverse input torque is applied, the reverse input one-way clutch 2 is not unlocked because the reverse input one-way clutch pawl 2a has a large rotational resistance (oscillation resistance). When the reverse input torque disappears, the reverse input operation portion 9a is moved to the original position by the urging force of the reverse input elastic member 9c, and the lock is released.

  With this configuration, the driving force from the rear sprocket 4 is directly connected or increased and transmitted to the tire. On the other hand, the reverse input from the tire is decelerated and transmitted from the rear sprocket 4 to the motor shaft through a power transmission element such as a chain, so that regenerative charging is possible.

  In this embodiment, the reverse input one-way clutch 2 is provided between the first sun gear 3 a-1 and the axle 5, but may be provided between the second sun gear 3 a-2 and the axle 5. In this embodiment, the planetary gear 3b has two stages, but one or three or more planetary gears may be used. Further, the shaft hole 5a of the axle 5 has holes extending in the axial direction from both ends, and the central portion in the axial direction of the axle 5 is solid. It may be a through hole that extends.

  Although not shown, a center one-way clutch is provided between the crankshaft and the crank sprocket that locks in the direction in which the driving force is transmitted and idles with respect to the reverse input. For this reason, the driving force is not transmitted to the crankshaft, the pedal, and the like by reverse input. As this center one-way clutch, a well-known one-way clutch such as a roller clutch, a sprag clutch, or a ratchet clutch can be employed.

  Further, when the vehicle is not driven backward (when the bicycle is dismounted and pulled backward), the absolute rotational direction is reversed, but the relationship between the relative rotation of the rear sprocket 4 and the hub case 7 is the same as that during forward driving. The same.

1 Rear Hub 2 Reverse Input One Way Clutch 2a Reverse Input One Way Clutch Claw 2b Clutch Claw Shaft 2g Reverse Input Clutch Cam Surface 2h Elastic Member 3 Transmission Mechanism 3a Sun Gear 3a-1 First Sun Gear 3a-2 Second Sun Gear 3b Planetary gear 3c Planetary carrier 3d Outer ring gear 3e Shifting one-way clutch 3e-1 Second one-way clutch 3e-2 Third one-way clutch 3f Shifting clutch cam surface 3g Shifting one-way clutch pawl 3h Elastic member 4 Rear sprocket 5 Axle 6 Hub flange 7 Hub case 8 First one-way clutch 9 Clutch switching device 9a Reverse input operation portion 9b Reverse input sleeve 9c Reverse input elastic member 9d Tapered portion 9e Notch portion 9f Reverse input pin 9g Reverse input side hole 10 Shift control mechanism 10a Shift operation 10b Change sleeve 10c Use the elastic member 10d tapered portion 10e notched portion 10f shift pin 10g shifting lateral hole 11, 12, 13 bearing portion 14 both clutch cam surfaces

Claims (17)

A secondary battery and an auxiliary drive motor are attached to the frame connecting the front wheel and the rear wheel, and the pedaling force transmitted from the crankshaft or the driving force by the output of the motor can be transmitted to the driving wheel. In the rear hub built-in transmission for the battery-assisted bicycle used in the battery-assisted bicycle provided with the regeneration mechanism for returning the regenerative power generated by the reverse input from the drive wheel to the output shaft of the motor to the secondary battery,
The hub (1) provided on the drive wheel includes a speed change mechanism (3), a reverse input one-way clutch (2), and a clutch switching device (9).
The speed change mechanism (3) is constituted by a planetary gear mechanism, has at least one sun gear, and has a function of transmitting a driving force generated by the pedaling force or the output of the motor to the driving wheel through a sprocket (4). And a shift control mechanism (10) for shifting the sun gear (3a) to be rotatable or non-rotatable around the axle (5) with respect to the driving force from the sprocket (4). ,
The reverse input one-way clutch (2) is provided between at least one sun gear (3a) and an axle (5), and the reverse input one-way clutch (2) is a ratchet clutch, and the clutch switching The device (9) allows the reverse input one-way clutch (2) to switch the sun gear (3a) to be rotatable or non-rotatable around the axle (5) with respect to the reverse input from the drive wheels. The reverse input one-way clutch (2) includes a reverse input one-way clutch pawl (2a) provided on the sun gear (3a) and a reverse input provided on the outer surface of the axle (5). A clutch cam surface (2g), and the clutch switching device (9) passes through the inside of the axle (5), and one end of the clutch switching device (9) is pulled out from the axle (5). The reverse input operation part (9a) capable of moving in the direction is provided, and the reverse input one-way clutch (2) can be switched by moving the reverse input operation part (9a) in the axial direction. And
At the time of driving, the driving force from the sprocket (4) is transmitted to the driving wheel through the speed change mechanism (3), and at the time of forward non-driving, the reverse input operation unit (9a) of the clutch switching device (9) is operated by the operation. By making the sun gear (3a) and the axle (5) in the reverse input one-way clutch (2) non-rotatable with respect to the reverse input, the reverse input torque from the drive wheel is transmitted to the sprocket (4). A rear hub built-in transmission for a battery-assisted bicycle, characterized by having a function that can be performed.   The clutch switching device (9) includes a reverse input sleeve (9b) provided with a notch (9e), and the notch (9e) is moved by operating the reverse input operation part (9a) in the axial direction. ) Moves between the position of the reverse input clutch cam surface (2g) and the position retracted from the reverse input clutch cam surface (2g), and the movement of the reverse input one-way clutch (2) The rear hub built-in transmission for a battery-assisted bicycle according to claim 1, wherein switching is performed.   The rear hub internal transmission for a battery-assisted bicycle according to claim 2, wherein the notch (9e) of the reverse input sleeve (9b) includes a tapered portion (9d) at an axial end thereof.   The rear hub internal transmission for a battery-assisted bicycle according to claim 2 or 3, wherein the notch (9e) of the reverse input sleeve (9b) has a tapered portion at an end in a circumferential direction thereof.   The reverse input sleeve (9b) is fixed to the axle (5) by a reverse input pin (9f) inserted into a reverse input horizontal hole (9g) provided in the axle (5), and the reverse input The reverse input sleeve (9b) is moved in the axial direction by moving the pin (9f) in the axial direction in the reverse input horizontal hole (9g) by the reverse input operation portion (9a). The rear hub built-in transmission for a battery-assisted bicycle according to any one of claims 2 to 4.   The rear hub internal transmission for a battery-assisted bicycle according to any one of claims 2 to 5, wherein the reverse input sleeve (9b) is urged in the axial direction by a reverse input elastic member (9c).   The speed change mechanism (3) includes a speed change one-way clutch (3e) for switching the sun gear (3a) to be rotatable or non-rotatable around the axle (5), and the axle of the speed change one-way clutch (3e). The shift control mechanism (10) performs switching between rotation and non-rotation with respect to (5), and the one-way clutch (3e) for shifting is a gear for shifting provided in the sun gear (3a). 7. A ratchet clutch comprising a one-way clutch pawl (3g) and a shift clutch cam surface (3f) provided on the outer surface of the axle (5). The rear hub built-in transmission for the battery-assisted bicycle described in 1.   The speed change control mechanism (10) has a speed change operation part (10a) that passes through the axle (5) and has one end pulled out from the axle (5) and can be moved in the axial direction from the outside. The rear hub for a battery-assisted bicycle according to claim 7, wherein the shift one-way clutch (3e) can be switched by moving the shift operation portion (10a) in the axial direction. Internal gearbox.   A plurality of irregularities are provided on the outer surface of the axle (5) along the circumferential direction, and the functions of both the reverse input clutch cam surface (2g) and the shift clutch cam surface (3f) are exhibited on the irregularities. The rear hub built-in transmission for a battery-assisted bicycle according to claim 7 or 8.   The speed change control mechanism (10) includes a speed change sleeve (10b) provided with a notch (10e), and the notch (10e) is moved by operating the speed change operation part (10a) in the axial direction. It moves between the position of the shift clutch cam surface (3f) and the position retracted from the shift clutch cam surface (3f), and the shift is performed to switch the one-way clutch (3e). The rear hub built-in transmission for a battery-assisted bicycle according to any one of claims 7 to 9.   The rear hub internal transmission for a battery-assisted bicycle according to claim 10, wherein the notch (10e) of the speed change sleeve (10b) includes a tapered portion (10d) at an axial end thereof.   The rear hub internal gearshift for a battery-assisted bicycle according to claim 10 or 11, wherein the notch (10e) of the shift sleeve (10b) has a tapered portion at a circumferential end thereof.   The speed change sleeve (10b) is fixed to the axle (5) by a speed change pin (10f) inserted into a speed change horizontal hole (10g) provided in the axle (5), and the speed change pin (10f) The shift sleeve (10b) is moved in the axial direction by operating the shift operation portion (10a) in the axial direction within the shift lateral hole (10g). The rear hub built-in transmission for a battery-assisted bicycle according to any one of 10 to 12.   The rear hub internal transmission for a battery-assisted bicycle according to any one of claims 10 to 13, wherein the shift sleeve (10b) is urged in the axial direction by a shift elastic member (10c).   The portion of the shift sleeve (10b) covering the shift one-way clutch pawl (3g) and the portion of the reverse input sleeve (9b) covering the reverse input one-way clutch pawl (2a) are respectively the axles. 15. It is arranged on both sides with respect to (5) and is arranged at a position where the phase is shifted by 90 [deg.] Around the axle (5). Rear hub internal gearbox for electric assist bicycles.   The sprocket (4) is disposed closer to one axial direction in the hub case (7), the clutch switching device (9) is disposed closer to one axial direction in the hub case (7), and the shift control mechanism The rear hub built-in transmission for a battery-assisted bicycle according to any one of claims 10 to 15, wherein (10) is disposed on the other side.   The rear hub built-in transmission for a battery-assisted bicycle according to any one of claims 1 to 16, wherein the operation of the clutch switching device (9) is linked with a brake operation.

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