JPH08337192A - Motor assisted bicycle - Google Patents

Abstract

PURPOSE: To realize the appropriate power assist irrespective of the position of a transmission by directly calculating the rotational speed by the signal from a detector incorporated in a wheel to realize the control. CONSTITUTION: When a pedal is stepped in, a torque sensor incorporated in an electric driving device 4 detects the load, and transmits the signal to a micro computer incorporated in a control circuit 3. The micro computer calculates the torque required for the pedal load by the signal and the bicycle speed signal transmitted from a generator 1 to operate the electric driving device 4. The generator 1 incorporated in a front wheel generates the AC voltage corresponding to the rotational speed of the wheel. The voltage is pulsed, and the pulse is counted by the micro computer, and the actual speed of the bicycle is obtained based on the wheel size of the bicycle, and the electric driving device 4 is controlled so as to gradually reduce the assist ratio according to the actual speed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric bicycle capable of operating an electric drive device according to a pedal load,
More specifically, it relates to an electric bicycle having an electric drive device that detects the speed of the bicycle and assists the pedal load within a prescribed range.

[0002]

2. Description of the Related Art Various electric bicycles have been proposed, in which a driving force by human power and a driving force by an electric motor are provided in parallel, and the electric power is assisted by the electric motor within a prescribed range according to a pedal load. The range of assistance by the device is 50% from 0 to 15 km / h, and gradually decreases from 15 km / h to 24 km / h according to the vehicle speed.
It must be controlled to be 0% at / h.

[0003]

On the other hand, since the vehicle speed is detected in the electric drive device which is connected by the pedal shaft or the pedal shaft and the gears, the bicycle equipped with the conventional transmission incorporated in the rear wheels is detected. In, the position information of the transmission is not provided to the control circuit, and the speed information provided from the speed detector changes proportionally depending on the transmission position.

More specifically, since the assistance exceeding the specified range cannot be performed, it is set so that an accurate speed can be detected at a high speed position of the rear wheel transmission, so that the other positions of the transmission are proportional to the gear ratio. Inevitably, the power assist rate must be reduced at a speed lower than the specified speed. FIG. 7 is a characteristic diagram of a conventional electric bicycle power assist rate. At medium speeds, 12 km / h or more, and at low speeds, 9 km / h or more, the assist rate temporarily decreases. The greatest advantage of electric bicycles is that they are easier to ride than conventional human-powered vehicles, especially on slopes, and usually use medium or low speed positions on slopes. However, the power assist rate is substantially limited as described above.

[0005]

According to the invention, the object is to detect the rotational speed directly at the front or rear wheels and to calculate the vehicle speed by means of a microcomputer built into the control circuit, whereby This is achieved by an electric bicycle characterized by being capable of power assist within the range.

[0006]

The present invention has been made in view of such circumstances, and makes it possible to perform a prescribed power assist at a prescribed speed regardless of the position of the transmission incorporated in the rear wheels.

[0007]

1 is a side view of an electric bicycle according to an embodiment of the present invention. In FIG. 1, a torque sensor, which is composed of a generator 1, an electric drive device 4, a control circuit 3, a rechargeable battery 5 and a headlight 2, and which is built in the electric drive device 4 when the pedal is manually depressed Is detected, and this signal is sent to the micro computer incorporated in the control circuit 3. The micro computer calculates the torque required for the pedal load based on this signal and the vehicle speed signal sent from the electric motor 1, and operates the electric drive device 4. The generator 1 built in the front wheels constantly provides an AC voltage signal according to the rotation speed of the wheels. This generator 1 is normally used for illumination at night, and an AC voltage having a frequency corresponding to the number of poles of the generator and the vehicle speed is constantly output during traveling regardless of whether or not the lamp is turned on. Although the vehicle speed is normally proportional to the voltage, it is disadvantageous to use the voltage as the vehicle speed signal because the voltage greatly changes depending on whether or not the lighting is turned on. On the other hand, an AC voltage as shown in FIG. 2A is constantly output from this generator, and the frequency of the AC voltage is always proportional to the vehicle speed. This AC voltage is applied to the waveform shaping circuit built in the control circuit and converted into the pulse waveform shown in FIG. This pulse waveform is counted by the built-in microcomputer, and the actual bicycle speed is calculated based on the bicycle wheel size information. Within 15% up to 15 km / h, from 15 km / h to 24
The electric drive device is controlled so as to gradually reduce the assist ratio according to the vehicle speed during the km / h period. In this electric bicycle, the power assist rate is always controlled by the actual vehicle speed of the bicycle, regardless of the position of the speed machine built in the rear wheels.
Especially on slopes, the convenience is greatly improved.

FIG. 3 is a side view of an electric bicycle according to a second embodiment of the present invention. In FIG. 3, a pulsed rotation signal provided from a magnetic sensor incorporated in the inside of a rotary plate of a brake 6 incorporated in a rear wheel, which is incorporated in a sensor magnet and a brake housing, is applied to a built-in micro controller of the control circuit 3. The actual vehicle speed of the bicycle is calculated based on the information of the wheel size of the bicycle counted by the computer and 1
Within 50% up to 5km / h, from 15km / h to 24km / h
In the meantime, the electric drive device 4 is controlled so as to gradually reduce the assist rate according to the vehicle speed.

FIG. 4 shows the structure of the brake according to the invention. It is composed of a rotating plate 7 of the brake 6 and a brake housing 8 incorporating a brake shoe. FIG. 5 shows a structural diagram of the rotary plate. The rotary plate 7 is incorporated in the axle of the rear wheel and rotates integrally with the rear wheel. A sensor magnet 9 is incorporated inside the rotating plate 7, and the sensor magnet 9 has a plurality of N poles and S poles alternately magnetized. The number of poles should be as large as possible in consideration of the measurement accuracy at low speeds, but on the other hand, the minimum width per pole is restricted due to magnetism.
To about 100 poles are selected. Further, FIG. 6 shows a structural view of the brake housing. This brake housing 8
There is a brake pad 10 on the inside of the outer circumference of the rotating plate, and the brake pad operating lever 11 is moved through the wire by operating the brake lever of the handle to press the brake pad 10 against the rotating plate 7 to decelerate or stop the bicycle. . A magnetic sensor 12 is incorporated inside the brake housing 8 and the sensor magnet 9 rotates, whereby a pulsed voltage is output from the magnetic sensor 12. On the other hand, bicycles have a variety of wheel sizes from about 20 inches to 27 inches depending on the use and design, and the actual traveling speed cannot be obtained only by the rotational speed of the wheels. It is necessary to input the wheel size to the microcomputer in advance,
For that purpose, it is necessary to prepare an electric drive device for each wheel size. Therefore, in the present invention, the electric drive device control circuit is provided with a plurality of jumper wires for selecting a wheel size, and when this device is incorporated into a bicycle, by cutting the jumper wires suitable for the wheel size, any assumption Even for the wheel size, the wheel size is automatically determined in the microcomputer and the actual traveling speed can be accurately calculated.

[0010]

As described above, according to the present invention, since the vehicle speed is constantly measured, the power assist ratio can be controlled to the specified value regardless of the position of the transmission with built-in rear wheels. Further enhance the convenience of bicycles.
In addition, since the same electric drive unit can automatically set all the expected wheel sizes, the actual traveling speed can be calculated regardless of the wheel size, and the standardization of the electric drive unit improves productivity and lowers the price. It is possible.

[Brief description of drawings]

FIG. 1 is a side view of an electric bicycle according to an embodiment of the present invention.

FIG. 2A is an output waveform diagram of an electric bicycle generator according to an embodiment of the present invention. FIG. 2B is a pulse waveform diagram after waveform shaping according to an embodiment of the present invention.

FIG. 3 is a side view of an electric bicycle according to another embodiment of the present invention.

FIG. 4 is a brake structure diagram of the present invention.

FIG. 5 is a structural diagram of a rotating plate of the present invention.

FIG. 6 is a block diagram of the brake housing of the present invention.

FIG. 7 is a characteristic diagram of a conventional electric bicycle power assist rate.

[Explanation of symbols]

 1 Generator 2 Headlight 3 Control Circuit 4 Electric Drive Device 5 Rechargeable Battery 6 Brake 7 Rotating Plate 8 Brake Housing 9 Sensor Magnet 10 Brake Pad 11 Brake Pad Operating Lever 12 Magnetic Sensor

Claims (6)

[Claims] 1. An electric bicycle having a pedal drive device driven by human power and a drive device driven by an electric motor for assisting human power (hereinafter referred to as an electric drive device), provided from a generator built in front wheels. An electric bicycle characterized in that the speed of the bicycle is calculated by a signal to control the electric drive device. 2. The electric bicycle according to claim 1, wherein the signal provided from the generator built in the front wheels is an AC voltage, and the frequency of the AC voltage is proportional to the rotation speed of the front wheels. 3. The electric device according to claim 1, further comprising an electric drive device control circuit having a circuit for converting an AC voltage signal provided from a generator into a pulse waveform and outputting the pulse waveform to a microcomputer. bicycle. 4. In an electric bicycle having a pedal drive device driven by human power and an electric drive device assisting human power, the speed of the bicycle is calculated by a signal provided from a speed detector incorporated in a brake of a rear wheel. An electric bicycle characterized by controlling the electric drive device. 5. The electric bicycle according to claim 4, wherein the speed signal provided from the speed detector is pulsed and proportional to the rotational speed of the rear wheels. 6. The wheel size can be determined by providing one or more jumper wires in a circuit for controlling the electric drive device, and cutting the jumper wires determined before being incorporated in the bicycle. Alternatively, the electric bicycle according to claim 2 or claim 3 or claim 4 or claim 5.