JPH0885491A - Motor-assisted bicycle - Google Patents

Abstract

PURPOSE: To provide a motor-assisted bicycle capable of correctly detecting menual torque by simple constitution to accurately drive a motor according to this torque. CONSTITUTION: In a motor-assisted bicycle wherein a spring 40 is interposed between a pedal and a wheel to detect the magnitude of stepping force by the expansion and contraction of the spring 40 to assist manual drive by an electrically-driving part according to this magnitude, in order to detect the expansion and contraction of the spring 40, the expansion and contraction of the spring 40 is converted into the movement in an axle 39 direction, and this movement quantity is detected by the change of inductance due to the movement of a ferrite 48 in a coil 49 to detect the magnitude of torque.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention has both a human-powered driving unit and a motor-driven electric driving unit, drives the electric motor according to the magnitude of the human-powered driving force, and drives the human-powered driving force of the electric motor. The present invention relates to an electric bicycle assisted by driving force.

[0002]

2. Description of the Related Art Conventionally, such an electric bicycle is provided with a human-powered drive system and an electric motor-driven drive system in parallel, as described in Japanese Patent Application Laid-Open No. 4-358987 (B62M23 / 02). It is known that the driving force of the system is detected to control the output of the electric motor.

In this electric bicycle, in order to detect the driving force of the driving system by human power, that is, the rotational torque of the pedal, a cylindrical shaft is fitted on the crankshaft of the pedal, and the pedaling force of the pedal is the cylindrical shaft. Is transmitted to the planetary gear mechanism via a one-way clutch, and further transmitted to the rear wheels by a drive shaft meshed with the planetary gear mechanism. One end of a torque detection lever is interposed in the planetary gear mechanism, and the other end is in contact with a second lever connected to a potentiometer. The second detection lever is returned by a return spring, the second lever rotates through the torque detection lever by an angle corresponding to the pedaling force of the pedal, and the amount of rotation is measured by a potentiometer to determine the crankshaft. The torque applied to is detected.

Further, the rotational driving force from the electric motor is also transmitted to the cylindrical shaft through the one-way clutch and the planetary gear mechanism, and the driving force of the electric motor is transmitted according to the detected torque. It is designed to increase and reduce the burden of human power.

[0005]

However, in such a structure, since the drive portion is located away from the rear wheel,
There is a large loss of force before the driving force is transmitted to the rear wheels,
In order to transmit power to the rear wheels, vertical rotations of the pedal and the electric motor must be converted into horizontal rotations of the drive shaft, and further rotations must be converted into vertical rotations to rotate the rear wheels. In addition to the complicated structure, there is a problem in that it becomes large in size, and moreover, a failure is likely to occur.

On the other hand, since the torque applied to the crankshaft is detected, as described above, if there is a large loss of force before the driving force is transmitted to the rear wheels, it will be lower than the required rotational driving force of the electric motor. There is a problem that the driving force is controlled and the assisting force of human power becomes small. Further, since the torque is detected by the potentiometer via the torque detection lever and the second lever, there is a possibility that a detection error may occur due to vibration.

The present invention has been made in view of the above circumstances, and its purpose is to convert the torque generated in the wheel into movement in the axle direction and detect the movement amount to thereby simplify the construction. Accurately detects torque due to human power,
An object of the present invention is to provide an electric bicycle that assists a driving force by human power that drives an electric motor appropriately according to the torque.

[0008]

An electric bicycle according to a first aspect of the present invention comprises a human-powered drive unit that rotates wheels by pedaling force of a pedal, and an electric drive unit that rotates the wheels by driving an electric motor. In an electric bicycle that detects a torque generated on a wheel and controls the rotational drive of the electric drive unit based on the detected torque, a disc-shaped casing attached to the wheel and the pedal force that expands and contracts by the pedal force of the pedal. And a conversion member that converts expansion and contraction of the elastic member into movement of the wheel in the axle direction, and a torque detection unit that detects a movement amount of the conversion member. To do.

An electric bicycle according to a second aspect of the present invention is the electric bicycle according to the first aspect, wherein the converting member is provided with a rotating plate which is rotated by the expansion and contraction of the elastic body, and a projecting portion provided on the rotating plate, the end of which is inclined. The inclined portion, a sliding member slidably provided in the axle direction, a protrusion formed on the sliding member so as to abut the inclined portion, and the sliding member includes the rotating plate. And an elastic body that biases in a direction.

An electric bicycle according to a third aspect of the present invention is the electric bicycle according to the first aspect, wherein the conversion member is rotated by a screw gear formed around the axle of the wheel and expansion and contraction of the elastic body, and is movable in the axle direction. It is characterized by comprising a rotating plate and a screw portion formed on the rotating plate and screwed into the screw gear.

An electric bicycle according to a fourth aspect of the present invention is the electric bicycle according to the first aspect, wherein the torque detecting section includes a magnetic member or a conductive member and a coil arranged near the magnetic member or the conductive member, one of which is the above-mentioned. It is characterized in that it is adapted to be moved in the axle direction by the conversion member.

An electric bicycle according to a fifth aspect of the present invention is the electric bicycle according to the first aspect, wherein the torque detecting portion is a pair of electrodes arranged to face each other with a required distance, and a dielectric body arranged to be inserted into the gap between the electrode pairs. And one of which is adapted to be moved in the axle direction by the conversion member.

An electric bicycle according to a sixth aspect of the present invention is the electric bicycle according to the first aspect, wherein the torque detecting portion includes a magnetic body and a magnetic detector arranged to face the magnetic body, one of which is formed by the converting member. It is characterized in that it is adapted to be moved in the axle direction.

An electric bicycle according to a seventh aspect of the present invention is the electric bicycle according to the first aspect, wherein the torque detecting portion includes a reflecting plate that reflects light.
An optical unit including a light emitting unit that emits light to the reflecting plate and a light receiving unit that receives the reflected light from the reflecting plate and detects the light receiving position, and the reflecting plate or the optical unit is the conversion member. It is characterized by being moved in the direction of the axle.

[0015]

In the electric bicycle according to the first aspect of the present invention, when the user steps on the pedal, the pedaling force is transmitted from the pedal to the disk-shaped casing and the wheels via the elastic body. At the time of starting, when the user depresses the pedal, the elastic body contracts greatly,
When it starts moving at a constant speed, the elastic body hardly shrinks. Further, when accelerating, as in the case of starting, the elastic body contracts due to the depression of the pedal, and the elastic body presses the disk-shaped casing, whereby the wheels rotate and travel. In this way, the elastic body expands and contracts according to the magnitude of human torque,
The expansion / contraction is converted in the direction of the axle by the conversion member, and the torque detection unit detects this change, whereby the human torque is detected. Then, since the electric motor is driven with a magnitude corresponding to the detected human-power torque, when the human-power torque becomes large, the assistance by the electric motor becomes large, and the driving by human power and the drive by the electric motor are used together for traveling.

In the electric bicycle according to the second aspect of the invention, the elastic body contracts due to an increase in the human torque, the rotating plate rotates, and the inclined portion provided on the rotating plate rotates, and The abutting position of the protrusion that abuts against is moved, and the elastic member urging in the axle direction contracts or extends, and the sliding member moves in the axle direction. When the human torque decreases, the elastic plate contracted due to the increase of the human torque expands to rotate the rotating plate in the opposite direction, and the sliding member urges the force related to this rotation or the axial direction. It is restored by the stretching force of the elastic material. As a result, the manual torque is detected as the amount of movement of the sliding member in the axle direction.

In the electric bicycle according to the third aspect of the present invention, when the human torque increases, the elastic body shrinks accordingly and the rotating plate is rotated, and the screw portion formed on the rotating plate is formed around the axle. The rotating plate moves in the axle direction by being screwed in the axle direction following the screw gear thus formed. Further, when the human torque decreases, the elastic body contracted correspondingly expands, the screw portion moves backward following the screw gear, and the rotating plate moves to the original position in the axle direction. As a result, the manual torque is detected as the amount of movement of the sliding member in the axle direction as before.

In the electric bicycle according to the fourth aspect of the present invention, since one of the magnetic member or the conductive member or the coil is moved in the axial direction by the sliding member, the relative position between the magnetic member and the coil. When the magnetic poles approach each other or the volume of the magnetic member inserted into the coil increases, the inductance of the coil increases and the voltage applied to the coil decreases.
On the other hand, in the opposite case, the inductance of the coil decreases and the voltage applied to the coil increases. The change in voltage at this time is detected as a change in pedaling force, and the electric motor is driven according to this change to rotate the wheels. Further, when the conductive member moves near the coil, the action is opposite to that of the magnetic member. That is, when the conductive member approaches the coil, the ink inductance of the coil decreases and the voltage applied thereto increases, and when the conductive member moves away from the coil, the inductance of the coil increases and the voltage applied thereto decreases.

In the electric bicycle according to the fifth aspect of the invention, the torque detecting portion is either an electrode pair arranged facing each other with a required distance in between, or a dielectric body inserted so as to be inserted into the gap between the electrode pairs. On the other hand, since the conversion member is moved in the axle direction by the conversion member, the conversion member moves in the axle direction according to the torque, and the dielectric enters and leaves the gap between the electrode pairs.
The capacitance of the electrode pair changes. Therefore, when an AC voltage is applied to the electrodes, the voltage changes with a change in the electrostatic capacity according to the torque. Therefore, the torque is detected by detecting the amount of change.

In the electric bicycle according to the sixth aspect of the invention, the torque detecting portion is configured such that one of the magnetic body and the magnetic detector arranged to face the magnetic body is moved in the axial direction by the sliding member. Since it is moved, the distance between the magnetic body and the magnetic detector changes according to the torque. Therefore, in the magnetic detector, the detected magnetic flux density changes according to the torque, and the torque is detected by detecting the amount of change.

In the electric bicycle of the seventh invention, the light emitted from the light emitting portion of the optical portion is reflected by the reflecting plate, and the reflected light is received by the light receiving portion. Further, since either the light emitting unit or the light receiving unit or the reflecting plate arranged to face them is moved in the axle direction by the sliding member, the light receiving unit in the light receiving unit is moved according to the moving amount. The light receiving position of the reflected light changes. The light receiving unit detects the torque by detecting the amount of change.

[0022]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 7 is an overall perspective view of an electric bicycle according to the present invention, in which 1 is an electric bicycle main body. The electric bicycle main body 1 is provided with an electric motor 8 which will be described later, so that the driving force of the electric motor 8 is changed according to the magnitude of the torque due to the human power, and the power of the human power is assisted by the power of the electric motor 8 to travel. Has become.

A front wheel 2, a rear wheel 3, a handlebar 13 and a saddle 21 are attached to a frame 4 of the electric bicycle main body 1,
The front wheels 2 are steered by a steering wheel 13. A disk-shaped casing 5 is provided on the rotary shaft of the rear wheel 3. The disk-shaped casing 5 includes a rotating-side casing 6 and a fixed-side casing 7 fixed to the electric bicycle main body 1, and the rotating-side casing 6 rotates together with the rear wheel 3. In addition, the plate-shaped casing 5
Has a built-in electric motor 8 which is driven when electric drive is required to rotate the rotating side casing 6 together with a human power drive unit 10 described later. The drive portion provided with the board-like casing 5 is the electric drive portion 9.

The human-powered drive unit 10 is equipped with a pedal 11 and a chain 12. When the user steps on the pedal 11, the chain
The rear wheel 3 is rotated via 12. In this embodiment, the chain 12 is used as a human power transmission member, but the present invention is not limited to this, and a belt, a rotary shaft, or the like may be used instead of the chain 12.

Brake levers 14 and 15 are attached to the left and right ends of the steering wheel 13 for steering the front wheels 2, and brake devices 18 and 19 are provided to the front wheels 2 and the rear wheels 3 to provide brake levers 14 and 15. And the braking devices 18, 18 are connected by wires 16, 17. Then, by pulling the brake levers 14 and 15, the wires 16 and 17 are pulled, and the wires 16 and 17 are pulled.
The front and rear brake devices 18 and 19 are operated by 17 respectively. Further, a brake switch 20 is provided in the middle of the wires 16 and 17, so that the power supply to the electric motor 8 is stopped when the brake levers 14 and 15 are operated.

A battery section 22 serving as a power source of the electric motor 8 is attached to the frame 4 on the rear wheel 3. This battery part 22
Is composed of a battery case 23 slidably mounted on the frame 4 and a single rechargeable battery housed in the battery case 23.
It is a bolt.

Next, the disk casing 5 will be described with reference to FIG.

FIG. 8 is a front view showing the structure of the disc-shaped casing 5 shown in FIG. 7, and 7 in the figure is a fixed casing fixed to the main body of the electric bicycle. Fixed side casing 7
The control unit 24 including the control board 24 and the heat sink 25, the electric motor 8, the first pulley 27, the second pulley 28, and the final stage pulley 29.
Speed reducing mechanism 30 composed of two pulleys, and a transmission belt connecting between the pulleys of the speed reducing mechanism 30 and connecting the speed reducing mechanism 30 and the electric motor 8
31 are arranged. The final stage pulley 29 is fixed to the rotation side casing 6, and when the electric motor 8 rotates, the first belt to the final stage pulleys 27 to 29 transmit the transmission belt 31.
The rotation side casing 6 rotates together with the final stage pulley 29. Further, a one-way clutch (not shown) is interposed in the smaller pulley of the second pulley 28 connected to the final stage pulley 29, and the electric motor 8 is rotated when a force is applied from the pedal. Not so, that is, the pedal is light.

Between the first pulley 27 and the second pulley 28, a pressing member for adjusting the tension of a belt 31 connecting them to each other.
32 is provided, and the rotating head of the pressing member 32 is the belt 31.
Belt 31 by rolling inside and pushing it outside
Is being expanded.

An elongated hole is formed in the mounting portion of the rotary shaft of the first pulley 27, and an adjusting screw 33 is screwed into the elongated hole. Then, the first pulley 27 is moved in the direction in which the transmission belt 31 is stretched, and is fixed by the adjusting screw 33 in this state.

A chain sprocket 37 for transmitting the driving force from the chain to the casing on the rotating side is attached to the axle 39 of the rear wheel via the free wheel 38,
When the chain rotates in the reverse direction, the free wheel 38 does not transmit the driving force from the chain to the rotating side casing.

Next, the structure of the final stage pulley 29 will be described in detail with reference to FIGS.

1, 2 and 3 are a side sectional view, a front view and another side sectional view showing the structure of the final stage pulley, respectively. For the attachment part of the final stage pulley 29 to the axle 39,
Elastic springs 40, 40 are provided symmetrically with the axle 39 so as to be substantially tangential to the axle 39. One end of each of the springs 40, 40 is fixed to the final stage pulley 29, and the other end thereof is openable. The spring 40 is covered by a cover 34 attached to the final pulley 29. As a result, when a pedaling force is applied to the rear wheel, the pressing member 43, which will be described later, easily receives the force.

A pressure receiving member 41 having a convex side view is in contact with the opening side of the spring 40. The pressure receiving member 41 has a portion smaller than the diameter of the spring 40 and a large portion, and the small portion is the spring.
It fits inside 40 and the large part is mounted to cover spring 40. The pressure receiving member 41 is made of a slippery material such as iron or ceramics.

Around the axle 39 is the chain sprocket
A rotating plate 42 that rotates by the rotation of 37 is provided, and a pressing member 43 that presses the pressure receiving member 41 by the rotation of the chain sprocket 37 is provided on the rotating plate 42 symmetrically with the axle 39. This pressing member 43 is also made of a slippery material such as iron or ceramics as before. Further, in the final stage pulley 29, a rubber plate 35 for preventing the pressing member 43 pressed by the biasing force of the spring 40 from an impact is attached to a portion of the surface of the pressing member 43 which is in contact with the pressure receiving member 41 and faces the back surface. There is.

The rotating plate 42 is concentrically inserted inside the final stage pulley 29, and the pressing member 43 presses the spring 40 to rotate together with the final stage pulley 29. Further, when pressing the pressure receiving member 41, the pressing member 43 is slightly displaced in the pressing position, so that the portion contacting the pressure receiving member 41 has a curved surface.

Further, the rotating plate 42 is formed with two inclined portions 44 formed so as to face the rotating direction symmetrically with the axle 39,
The inclined portion 44 rotates with the rotation of the rotating plate 42.

Fixed side casing 7 from the rotating plate 42 of the axle 39
A sliding member 45 is provided around the side so as to be slidable in the direction of the axle 39, and a portion of the sliding member 45 facing the rotating plate 42 contacts an inclined portion 44 of the rotating plate 42. The projection 46 is provided. The sliding member 45 is biased toward the rotating plate 42 from the opposite side of the protrusion 46 by an elastic member, that is, a spring 47. Therefore, when the rotating plate 42 rotates, the protrusion of the sliding member 45
46 is pushed to the rotary plate 42 side along the slope of the inclined portion 44 by the bias of the spring 47, and the sliding member 45 moves to the rotary plate 42 side by a distance corresponding to the rotation amount of the rotary plate 42. . Then, when the rotating plate 42 returns to the original position, the protrusion 46 is formed by the inclined portion 44 of the rotating plate 42.
Is pushed toward the fixed casing 7 side, the spring 47 contracts, and the sliding member 45 returns to the original position on the fixed casing 7 side.
The rotating plate 42, the sliding member 45, and the like described above are referred to as conversion members.

When the rotating plate 42 is rotated, the rotating plate 42
When the protrusion 46 is pushed toward the fixed casing 7 side by the inclined portion 44 of the 42 and the rotary plate 42 returns to its original position, the protrusion 46 is no longer pressed, and the action of the spring 47 causes the sliding member 45 to rotate the rotary plate 42. 42
You may make it the structure returned to the original position of the side.

On the fixed casing 7 side of the sliding member 45, a ferrite 48, which is a magnetic member provided in the torque detecting section 51, is provided so that the sliding member 45 moves with it. . On the other hand, in the stationary side casing 7, a coil bobbin 50 is attached within the moving range of the ferrite 48 so as to face the ferrite 48, and a coil 49 is wound around the coil bobbin 50.

Next, driving by human power and detection of torque related to this driving will be described.

When the electric bicycle main body 1 starts running, the user applies a force to the pedal 11 to run. At this time, the force to stop the rear wheel 3 is great, but the chain sprocket 37 and the rotating plate 42 try to rotate. for that reason,
The rotating plate 42 presses the spring 40 via the pressing member 43 and the pressure receiving member 41, the spring 40 presses the final stage pulley 29, and the rotation side casing 6 and the rear wheel 3 fixed to the final stage pulley 29 rotate. The electric bicycle body 1 is driven by. At this time, since a large torque is applied to the rotating plate 42, the spring 40
Is greatly contracted, the rotating plate 42 is rotated accordingly, and the inclined portion
44 also rotates. When the rotating plate 42 rotates, the protrusion 46 of the sliding member 45 is pushed in the direction of the rotating plate 42 along the slope of the inclined portion 44 by the biasing force of the spring 47, and the sliding member 45 moves to the rotating plate 42. It moves to the side of the rotating plate 42 by a distance corresponding to the amount of rotation.

When the sliding member 45 moves to the rotating plate 42 side, the ferrite 48 moves inside the coil 49, which causes the coil 48 to move.
The inductance of 49 changes. That is, as the torque generated in the rotary plate 42 increases, the volume of the ferrite 48 inserted in the coil 49 increases, and the inductance of the coil 49 increases. The voltage applied to coil 49 is
Since the larger the inductance is, the smaller the inductance is, and conversely, the smaller the inductance is, the larger the inductance is. Therefore, the control unit 26 detects the magnitude of the torque by detecting the change in the voltage, and controls the drive of the electric motor 8 based on the detection result. To do.

On the other hand, when the user does not apply torque during flatland traveling, the rotating plate 42 rotates together with the final stage pulley 29. In this state, there is no torque, so the spring 40 does not contract and the sliding member 45 moves. do not do. Therefore, since the inductance of the coil 49 does not change, the voltage applied to the coil 49 does not change, and the drive from the electric motor 8 is not performed.

When the user accelerates on a level ground or an uphill, the spring 40 contracts when the torque due to the acceleration is applied, so that the rotating plate 42 responds to the torque as in the case of starting the running described above. When the ferrite 46 is inserted into the coil 49, the voltage applied to the coil 49 is reduced, and the protrusion 46 and the sliding member 45 that are in contact with the inclined portion 44 move. The control unit 26 controls the drive of the electric motor 8.

Next, the circuit of the torque detector 51 will be described with reference to FIG.

FIG. 4 is a circuit diagram of the torque detector according to the present invention. An alternating voltage having a pulse waveform described later is applied to the coil 49 described above from a microcomputer (hereinafter referred to as a microcomputer) provided in the control unit 26 (see FIG. 8). Ferrite 48
It outputs a pulse with a height corresponding to the relative distance from. The pulse output from the coil 49 is converted into an averaged signal by the DC conversion conversion unit 60 and given to the amplification unit 61, where it is amplified and input to the microcomputer.

FIG. 5 is a waveform diagram at each point in the circuit shown in FIG. 4, where (A) is a point A on the coil entry side and (B) is a point.
Shows the point B on the output side of the coil, and (C) shows the waveform of the pulse at the point C on the output side of the DC conversion unit (see also FIG. 4). A rectangular pulse voltage as shown in FIG. 5A is applied to the coil. When the ferrite approaches such a coil, the inductance of the coil increases, so the pulse output from the coil is as shown in FIG.
As described above, the pulse height becomes a sawtooth wave (broken line) lower than the sawtooth wave shown by the solid line. Then, when the pulse heights are averaged by the DC conversion converter, as shown in FIG. 5C, the level of the signal is lower than the level of the signal shown by the solid line by an amount corresponding to the amount of approach of the ferrite to the coil. The signal (dashed line) is obtained.

As described above, the torque is converted into the movement of the ferrite 48 in the direction of the axle 39, and the change in the inductance of the coil, which is changed by this, is converted into the change in the voltage to extract the electric signal. Torque can be detected, and human power can be assisted by accurate control.

FIG. 6 is a side sectional view showing the construction of another final stage pulley of the electric bicycle according to the present invention, which is constructed without the sliding member shown in FIG.

Since this embodiment is different from the above-described embodiment only in the rotating plate, the description of the same parts will be omitted and only the rotating plate will be described.

A rotary plate 53 of the conversion member 57 is provided around the axle 39, and the rotary plate 53 is rotated by the rotation of the chain sprocket 37 as before, and the final stage pulley 29 is rotated via the spring 40. Is pressed to rotate the rotating casing 6 and the rear wheel fixed to the final stage pulley 29. A screw gear 59 is formed around the axle 39, and a screw 54 that engages with the screw gear 59 is formed on the rotating plate 53. Then, the rotating plate 53 is rotated by the rotation of the chain sprocket 37, and is moved by screwing in the direction of the fixed casing 7 following the screw gear 59.

Further, the ferrite 55 of the torque detecting portion 58 is interposed between the screw 54 of the rotary plate 53 and the spring 47, and the ferrite is moved by the movement of the rotary plate 53 toward the fixed side casing 7. 55 is inserted into the coil 56. Then, the rotating plate 53
Moves toward the casing 6 on the rotating side, the ferrite 55
Is moved in the direction of the rotating side casing 6 together with the rotating plate 53 by the bias of the spring 47.

Also in this embodiment, when torque generated by human power is generated, the rotating plate 53 is rotated and the ferrite 55 is inserted into the coil 56 in the same manner as in the above-described embodiments.
The inductance of 56 increases. This makes the coil
The voltage applied to 56 becomes small, and by detecting this change, the drive of the electric motor is controlled according to the magnitude of the voltage level.

In the above-described embodiment, ferrite, which is a magnetic material, is inserted in the coil,
The present invention is not limited to this, and conductive materials such as copper and aluminum may be used.

In this case, the combination of the conductive member and the coil can be regarded as one transformer, the primary side is a coil with a plurality of turns, the secondary side is a coil with one turn, and the distance between the coils on the secondary side is changed. When the coil of 1 turn approaches, the inductance of the coil on the primary side decreases, the voltage applied to the coil increases, and the coil of 1 turn increases, the inductance of the coil on the primary side increases. , The voltage applied to the coil is reduced. Utilizing this, it is possible to control the drive of the electric motor by converting the change of the torque into the change of the voltage.

Although the position of the ferrite moves in the coil, the inductance of the coil changes even when the ferrite approaches, so that the ferrite approaches the coil due to the movement of the sliding member or the rotating plate. It goes without saying that the structure may be such that it is not inserted into the coil.

Further, in the above-mentioned embodiment, the ferrite, which is a magnetic material, is inserted into the coil. However, the present invention is not limited to this, and the coil is attached to the sliding member and the ferrite is It goes without saying that it may be fitted on the outside.

As described above, the torque generated by the pedaling force applied to the pedal is converted by the conversion member in the direction of the axle of the wheel, and the displacement of the movement of the conversion member is detected by the torque detection unit, and the electric motor is driven according to the magnitude of the displacement. The drive control is performed, and the electric drive unit, the torque detection unit, and the control unit are built in the disk-shaped casing, so a compact configuration can be achieved, and the torque can be detected in consideration of all the weight applied to the rotating side casing, which is a delicate operation. It is possible to accurately detect the human power torque that makes various changes. Further, since the torque is detected by the movement in the axle direction, a large amount of displacement can be taken, accurate and fine torque can be detected, and human power can be assisted by accurate control.

Further, since the magnetic member or the electrically conductive member moves in or near the coil fixed in the disk casing according to the human torque, the torque can be detected as a change in voltage due to a change in inductance. With this, fine torque can be detected, and human power can be assisted by accurate control.

9 and 10 are side sectional views showing the structure of another torque detecting portion according to the present invention, in which the torque is detected by the change of the dielectric constant. Both figures 9,
In FIG. 10, parts corresponding to those in FIGS. A cylindrical dielectric 70 is attached to the end of the sliding member 45 facing the spring 47. Dielectric 70
The inner diameter of the sliding member 45 side is substantially the same as the sliding member 45, and the other side has a larger required inner diameter. The dielectric 70 moves in the same direction as the sliding member 45 moves to the fixed casing 7 side by the rotation of the rotating plate 42, and when the rotating plate 42 returns to its original position, it is biased by the spring 47. It moves to the rotating plate 42 side. In the moving area of the dielectric 70, the electrodes 71, 71 are
It is arranged concentrically with 39 and is separated by a specified distance.
The element 70 moves back and forth in the gap between the electrodes 71, 71.

FIG. 11 is a circuit diagram of the torque detector shown in FIG. The control unit 26 (see FIG. 8) is provided on one of the electrodes 71, 71 described above.
A pulse of a predetermined voltage is applied from the microcomputer provided in (see) and the other is grounded. When the sliding member slides toward the fixed casing by the rotation of the rotating plate and the dielectric 70 moves, the dielectric 70 causes the electrodes 71,
Since the electrodes 71, 71 are inserted in the gap of 71, the electrostatic capacitances of the electrodes 71, 71 increase in accordance with this movement amount, and thus the pulse applied from the microcomputer becomes a sawtooth pulse having a low height.
This pulse is given to the DC conversion conversion unit 60, converted into an averaged signal there, and then given to the amplification unit 61.
When the amplified signal is input to the microcomputer, the microcomputer compares the input amplified signal with the reference signal to calculate the movement amount of the dielectric 70, and controls the drive of the electric motor according to the calculated movement amount.

Although the dielectric member is moved by the sliding member in the present embodiment, the present invention is not limited to this, and the electrodes may be moved by the sliding member. Needless to say.

FIG. 12 is a side sectional view showing the structure of still another torque detecting portion, in which the torque is detected by the change of the magnetic flux density. An annular magnet 74 is provided at an end of the sliding member 45 opposite to the rotary plate 42, and a magnetic detector 75 such as a Hall element or a magnetic resistance element is provided on the fixed side casing 6 as a magnet.
It is mounted facing the 74. In such a torque detection unit, when the torque is applied, the rotating plate 42 rotates, and the magnet 74 moves as the sliding member 45 slides toward the fixed casing 7 side. Approach the detector 75. When the magnet 74 approaches the magnetic detector 75, the magnetic flux density in the magnetic detector 75 increases and the output of the magnetic detector 75 increases, so that the magnitude of the applied torque can be detected.

Although the sliding member is provided with a magnet in the present embodiment, the present invention is not limited to this, and the sliding member may be provided with a magnetic detector and the fixed side casing 6 may be provided with a magnet. It goes without saying that it is good.

FIG. 13 is a side sectional view showing the construction of still another torque detecting portion according to the present invention, in which the torque is detected by the change of the light receiving position of the reflected light. Sliding member
An annular reflecting plate 77 is provided at the end opposite to the rotating plate 42 of 45, the fixed side casing 7 has a light emitting portion 78 having a lens and an LED (light emitting diode), and a PSD (semiconductor position detecting element or Optical position detection element) or linear CCD
An optical section 80 including a light receiving section 79 including a (charge transfer device) and the like is attached so as to face the reflection plate 77.

FIG. 14 shows an optical section 80 and a reflector 77 shown in FIG.
FIG. The light emitted from the LED 78b is focused by the lens 78a, enters the reflecting plate 77 at a predetermined incident angle, and is reflected by the reflecting plate 77. In the path of the reflected light, the light receiving unit 79 is arranged so as to receive the reflected light at a substantially right angle.

In such a torque detecting section, when the torque is applied, the rotating plate 42 rotates, and the reflecting plate 77 moves as the sliding member 45 slides toward the stationary casing 7. It moves and approaches the light emitter 78. When the reflecting plate 77 approaches the light emitting device 78 as shown by the broken line in FIG. 14, the path of the reflected light moves in parallel as shown by the dashed line in FIG. The light receiving position at moves in parallel. Therefore, the magnitude of the applied torque can be detected by obtaining the change in the light receiving position.

In the present embodiment, the sliding member is provided with the reflecting plate, but the present invention is not limited to this, and it goes without saying that the sliding member may be provided with an optical portion.

[0071]

As described above in detail, in the electric bicycle according to the first aspect of the present invention, the compact structure allows the torque to be detected in consideration of all the weight applied to the disc-shaped casing, and the human power that changes delicately. The torque can be accurately detected. Further, since the torque is detected by the movement in the axle direction, a large amount of displacement can be taken, accurate and fine torque can be detected, and human power can be assisted by accurate control.

In the electric bicycle according to the second and third aspects of the invention, the change in human torque can be accurately converted into movement in the axle direction with a relatively simple structure, and a failure is less likely to occur.

In the electric bicycle according to the fourth, fifth, sixth and seventh aspects of the present invention, the present invention has excellent effects such that the amount of movement converted in the axle direction can be detected accurately and finely.

[Brief description of drawings]

FIG. 1 is a side sectional view showing a configuration of a final stage pulley.

FIG. 2 is a front view showing a configuration of a final stage pulley.

FIG. 3 is another side cross-sectional view showing the configuration of the final stage pulley.

FIG. 4 is a circuit diagram of a torque detector according to the present invention.

5 is a waveform chart at each point in the circuit shown in FIG.

FIG. 6 is a side sectional view showing a configuration of another final stage pulley of the electric bicycle according to the present invention.

FIG. 7 is an overall perspective view of an electric bicycle according to the present invention.

8 is a front view showing the configuration of the board-like casing shown in FIG. 7. FIG.

FIG. 9 is a side sectional view showing a configuration of another torque detection unit according to the present invention.

FIG. 10 is a side sectional view showing a configuration of another torque detection unit according to the present invention.

FIG. 11 is a circuit diagram of the torque detector shown in FIG.

FIG. 12 is a side sectional view showing the configuration of still another torque detection unit.

FIG. 13 is a side sectional view showing the configuration of still another torque detection unit according to the present invention.

FIG. 14 is a partially enlarged view of the optical unit and the reflector shown in FIG.

[Explanation of symbols]

 3 Wheels (rear wheels) 5 Disc-shaped casing 8 Electric motor 9 Electric drive unit 10 Human power drive unit 11 Pedal 26 Control unit 39 Axle 40 Elastic body (spring) 42 Rotating plate 44 Inclined portion 45 Sliding member 46 Projection 47 Elastic body ( Spring) 48 Magnetic member (ferrite) 49 Coil 51 Converting member 52 Torque detector 53 Rotating plate 54 Screw gear 55 Magnetic member (ferrite) 56 Coil 57 Converting member 58 Torque detector 70 Dielectric 71 Electrode 74 Magnet 75 Magnetic detector 77 Reflector 78 Light emitting part 79 Light receiving part 80 Optical part

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Kenmei Tanaka 2-5-5 Keihan Hondori, Moriguchi-shi, Osaka Sanyo Electric Co., Ltd. (72) Toshihiro Sugawara 2-chome, Keihanhondori, Moriguchi-shi, Osaka 5-5 Sanyo Electric Co., Ltd. (72) Inventor Toshihiro Matsumoto 2-5-5 Keihan Hondori, Moriguchi-shi, Osaka Sanyo Electric Co., Ltd.

Claims (7)

[Claims] 1. A human-powered drive unit that rotates a wheel by a pedaling force of a pedal, and an electric drive unit that rotates the wheel by a drive of an electric motor. The torque generated in the wheel by the pedaling force is detected, and the detected torque is detected. In an electric bicycle that controls the rotational drive of the electric drive unit based on, a disc-shaped casing attached to the wheel, an elastic body that expands and contracts by the pedal force of the pedal and transmits the pedal force to the disc-shaped casing, and the elastic body. An electric bicycle, comprising: a conversion member that converts expansion and contraction of a body into movement of the wheel in an axle direction, and a torque detection unit that detects a movement amount of the conversion member. 2. The conversion member includes a rotating plate that rotates by expansion and contraction of the elastic body, an inclined portion that projects from the rotating plate, and has an inclined end portion, and slides in the axle direction. A sliding member movably provided, a protrusion formed on the sliding member so as to abut the inclined portion, and an elastic body that biases the sliding member toward the rotating plate. The electric bicycle according to 1. 3. The conversion member is formed on a screw gear formed around an axle of the wheel, a rotating plate which is rotated by expansion and contraction of the elastic body and is movable in the axle direction, and the rotating plate. The electric bicycle according to claim 1, further comprising a screw portion screwed to the screw gear. 4. The torque detection unit includes a magnetic member or a conductive member and a coil arranged near the magnetic member or the conductive member, one of which is configured to be moved in the axle direction by the conversion member. The electric bicycle according to claim 1, wherein: 5. The torque detecting unit includes an electrode pair arranged to face each other with a required distance in between, and a dielectric body arranged to be insertable into a gap between the electrode pair, one of which is formed by the conversion member to an axle shaft. 2. The structure is adapted to be moved in the direction.
The listed electric bicycle. 6. The torque detecting unit includes a magnetic body and a magnetic detector arranged to face the magnetic body, one of which is configured to be moved in the axle direction by the converting member. The electric bicycle according to item 1. 7. The torque detecting unit includes a reflecting plate that reflects light, a light emitting unit that emits light to the reflecting plate, and a light receiving unit that receives reflected light from the reflecting plate and detects its light receiving position. 2. The electric bicycle according to claim 1, further comprising: an optical section including: the reflecting plate or the optical section configured to be moved in the axle direction by the conversion member.