JPH0891281A - Electric motor bicycle - Google Patents

Abstract

PURPOSE: To provide an electric motor bicycle in which the torque by a man power can be detected accurately in a simple structure, and an electric motor can be driven accurately according to the detected torque. CONSTITUTION: A circular bobbin 51 of a torque detector 50 is installed to an axle 39 from the outer side, and a coil 52 is wound on the bobbin 51. At a rotation side casing 6 side, three sheets of movable pieces 55 with abount a falchion form are provided at the equal intervals in the peripheral direction so as to cover the coil 52. The movable pieces 55 are supported by the first pin 53 extending from a rotary plate 42 and the second pin 54 extending from the rotation side casing 6, and they are made rotatable by making the second pin 54 as the axis. And the first pin 53 is rotated following the rotation of the rotary plate 42, the front end sides of the movable pieces 55 are rotated to the outer side of the bobbin 51 by making the second pin 54 as the axis, and the area of the movable pieces 55 to cover the coil 52 is reduced according to the 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 the conventional electric bicycle, since the torque applied to the crankshaft is detected, the loss of force until the driving force is transmitted to the rear wheels is not taken into consideration. However, there is a problem in that the drive control is performed to be lower than the required rotational drive force of the electric motor, and the effect of assisting human power is low. Further, the torque is the torque detection lever and the second
Since the potentiometer is used for detection via the lever, vibration may cause a detection error.

The present invention has been made in view of the above circumstances, and an object thereof is a coil arranged around an axle of a wheel, and a magnet whose area covering the coil changes according to a torque generated in the wheel. By including a member,
An object of the present invention is to provide an electric bicycle that accurately detects a torque due to human power with a simple configuration and drives an electric motor appropriately according to the detected torque.

[0007]

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 in a wheel and controls the rotational drive of the electric drive unit based on the detected torque, a coil provided around an axle of the wheel and an elastic body that expands and contracts according to the torque. A rotating plate that rotates together with the expansion and contraction of the elastic body; a magnetic member whose area covering the coil changes due to the rotation of the rotating plate; and torque detection that detects the torque based on a change in the voltage of the coil. And a section.

In the electric bicycle according to the second invention, in the first invention, the magnetic member is pivotally supported by a pin extending from a casing fixed to the wheel, and is pivoted by the pin extending from the rotating plate. It is characterized by being moved.

[0009]

In the electric bicycle of the present invention, when the user steps on the pedal, the pedaling force is transmitted from the pedal to the casing fixed to the wheel and the wheel through the rotating plate and the elastic body. At the time of starting, when the user depresses the pedal, the rotating plate tries to rotate, but torque is generated as if the wheels remain stationary, and the torque causes the elastic body to greatly contract, causing the rotation. The plate also rotates greatly. When the elastic body starts moving at a constant speed, the elastic body hardly shrinks, and the rotating plate hardly rotates. Further, when accelerating, the elastic body contracts due to the depression of the pedal, and the rotating plate rotates in response to the depression as in the case of starting. In this way, the rotating plate rotates according to the magnitude of the human torque.

On the other hand, a coil is provided around the axle of the wheel, and a magnetic member is arranged near the coil. This magnetic member is rotatably supported by a pin extending from a casing fixed to a wheel, and is pivoted by a pin extending from a rotating plate. The area that covers the coil changes due to the movement. When the area of the magnetic member covering 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. Then, the torque detector detects the torque based on the change in the voltage.

[0011]

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 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 power drive unit 10 is provided with a pedal 11 and a chain 12. When the user depresses 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 both left and right ends of a steering wheel 13 for steering the front wheel 2, and brake devices 18 and 19 are provided to the front wheel 2 and the rear wheel 3, respectively. 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 drawing 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.
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 a driving force from the chain to a rotating side casing is attached to a rear wheel axle 39 via a 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 construction of the final stage pulley 29 will be described in detail with reference to FIGS.

FIG. 1 is a side sectional view showing the construction of the final stage pulley, and FIG. 2 is a front view thereof. At the mounting portion of the final stage pulley 29 to the axle 39, springs 40, 40, which are elastic bodies, 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 48 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 47 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 pressing member 43 facing the back surface of the surface contacting the pressure receiving member 41. There is.

The rotating plate 42 is concentrically inserted inside the final stage pulley 29, and when a torque is applied, the pressing member is pressed.
43 presses the spring 40 and rotates together with the final stage pulley 29. When pressing the pressure receiving member 41, the pressing member 43 is slightly displaced from the pressing position, so that the portion contacting the pressure receiving member 41 has a curved surface. On the other hand, when the torque is removed, the rotating plate 42 returns to its original position due to the expansion of the spring 40.

An annular bobbin of the torque detection unit 50 is provided on the axle 39.
51 is fitted. The bobbin 51 has a U-shaped cut surface, and is attached to the stationary casing 7 with its opening facing the rotating casing 6. A coil 52 is wound around the bobbin 51.

On the side of the rotary casing 6, three substantially blue Dragon blade-shaped movable pieces 55 are arranged facing the coil 52 at equal intervals in the circumferential direction so as to cover the coil 52. The movable piece 55 is made of a magnetic material such as iron or ferrite.
The movable piece 55 is supported by a first pin 53 extending from the rotating plate 42 and a second pin 54 extending from the rotary casing 6, and is rotatable about the second pin 54. ing.

FIGS. 3 and 4 are front views of the torque detecting portion. FIG. 3 shows a state in which no torque is applied, and FIG.
Indicates that Tokul has been added. First
The pins 53, 53, 53 and the second pins 54, 54, 54 are arranged at equal intervals around the bobbin 51. Movable pieces 55, 5 in the shape of a nearly blue dragon sword
Slots 56, 56, 56 are formed in the vicinity of the base ends of the slots 55, 55 so as to be substantially tangential to the slots.
First pins 53, 53, 53 are slidably fitted in the 56.
In addition, the second pins 54, 54, 54 pass through the movable pieces 55, 55, 55 slightly on the tip side of the elongated holes 56, 56, 56.

The movable pieces 55, 55, 55 are pivotally supported by the second pins 54, 54, 54 so that their tip ends are in the direction opposite to the direction of rotation of the rotating plate. The width of the tip end side of the movable pieces 55, 55, 55 is substantially the same as the width of the bobbin 51.

In such movable pieces 55, 55, 55,
When no torque is applied, as shown in Fig. 3, the first pin
53, 53, 53 are at the ends of the elongated holes 56, 56, 56 on the side of the second pins 54, 54, 54, and the tip side of the movable pieces 55, 55, 55 is the coil.
It is designed to cover 52. At this time, the angle formed by the first pin 53 and the second pin 54 about the center point O of the bobbin 51 is θ.
is _a, the area of the movable piece 55, 55 and 55 covering the coil 52 is at a maximum. Therefore, the inductance of the coil 52 is high,
The voltage on coil 52 is small.

On the other hand, when torque is applied, as shown in FIG. 4, the first pins 53, 53, 53 are rotated in accordance with the rotation of the rotation plate, and the other side of the elongated holes 56, 56, 56 is rotated. The angle formed by the first pin 53 and the second pin 54 becomes θ _b (θ _a <θ _b ). The tip ends of the movable pieces 55, 55, 55 have the second pins 54, 54, 54
The shaft is rotated to the outside of the bobbin 51, and the area of the movable pieces 55, 55, 55 covering the coil 52 decreases in accordance with the torque. Therefore, the inductance of the coil 52 becomes low, and the voltage of the coil becomes large as compared to when the torque is not applied.

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

FIG. 5 is a circuit diagram of the torque detector according to the present invention. An alternating voltage having a pulse waveform described below is applied to the coil 51 described above from a microcomputer (hereinafter referred to as a microcomputer) provided in the control unit 26 (see FIG. 8). Covered movable piece
It outputs a pulse whose height corresponds to the area of 55. Coil 51
The pulse output from is converted into a signal averaged by the DC conversion conversion unit 60 and is given to the amplification unit 61, where it is amplified and input to the microcomputer.

FIG. 6 is a waveform diagram at each point in the circuit shown in FIG. 5, where (A) is the point A on the coil entry side, and (B).
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 FIG. 5 for both). A rectangular pulse voltage as shown in FIG. 6A is applied to the coil. When the movable piece covers such a coil, the inductance of the coil is large.
The pulse output from the coil becomes a sawtooth wave (broken line) whose pulse height is lower than the sawtooth wave shown by the solid line as shown in FIG. 6B.

On the other hand, when torque is applied and the area of the movable piece covering the coil decreases, the inductance of the coil decreases accordingly, and the pulse output from the coil has the waveform shown by the broken line in FIG. 6B. To the waveform indicated by the solid line.

Then, when the pulse heights are averaged by the DC conversion conversion unit, as shown in FIG. 6C, the level of the signal shown by the broken line corresponds to the area reduction amount of the wave piece covering the coil. A signal (solid line) of a higher level is obtained.

As described above, since the torque is detected by the change of the voltage applied to the coil, the change of the torque is directly converted into an electric signal, and the torque can be detected with high precision with a simple structure.

In this embodiment, the movable piece is designed so that the area covering the coil is reduced according to the torque. However, the present invention is not limited to this, and the area covering the coil is increased according to the torque. Needless to say, it is okay.

[0040]

As described above in detail, in the electric bicycle according to the first aspect of the present invention, the coil disposed around the axle and the magnetic member whose area covering the coil changes according to the torque generated in the wheel are provided. Since the torque is detected by the change in the voltage applied to the coil, the torque can be detected with high accuracy with a simple configuration. Further, the torque can be detected in consideration of all the weights applied to the wheels, and human power can be assisted by appropriate control.

In the electric bicycle according to the second aspect of the invention, the magnetic member is pivotally supported by the pin extending from the casing fixed to the wheel, and pivoted by the pin extending from the rotating plate. Therefore, the present invention has excellent effects such as erroneous detection due to vibration is prevented and failure is less likely to occur.

[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 a front view of a torque detector.

FIG. 4 is a front view of a torque detector.

FIG. 5 is a circuit diagram of a torque detector according to the present invention.

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

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.

[Explanation of symbols]

 6 Rotation Side Casing 7 Fixed Side Casing 29 Final Stage Pulley 39 Axle 40 Spring (Elastic Body) 50 Torque Detecting Unit 51 Bobbin 52 Coil 53 First Pin 54 Second Pin 55 Movable Piece 56 Long Hole

Claims (2)

[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, detects a torque generated on the wheel by the pedaling force, and detects the detected torque. In an electric bicycle that controls the rotational drive of the electric drive unit based on, a coil provided around the axle of the wheel, an elastic body that expands and contracts according to the torque, and a rotation that rotates together with the expansion and contraction of the elastic body. An electric bicycle, comprising: a plate, a magnetic member whose area covering the coil is changed by rotation of the rotating plate, and a torque detection unit which detects the torque by a change in voltage of the coil. 2. The magnetic member is pivotally supported by a pin extending from a casing fixed to the wheel, and is pivoted by a pin extending from the rotating plate. Electric bicycle.