JPH0872782A - Motor driven bicycle - Google Patents

Abstract

PURPOSE: To prevent a motor from damages and abrupt start by chopper controlling the electric current to the motor by a motor driving circuit correspondingly to a speed commanding signal generated by an accelerator operation and, interrupting the current when over-current flows to the motor and controlling the rotation of the motor to slowly rise in the start of the motor. CONSTITUTION: A motor controller 11 for controlling the rotation of a motor 6 is provided with a triangular wave generating circuit 12 and a speed commanding circuit 13 to output a speed commanding signal proportional to the rotational angle of an accelerator and stop the speed commanding signal in the control operation. These output signals are inputted to a comparing circuit 14 to control a motor driving circuit 16 through a pulse width modulating circuit 15 according to the comparation result in the comparing circuit and control the rotation of the motor 6. When overcurrent in the motor 6 is detected in an overcurrent detecting/interrupting circuit 16a, the feed to the motor 6 is stopped through the pulse width modulating circuit 15. A slow starting circuit 13a for allowing starting current to gradually rise in the start is additionally provided in the speed commanding circuit 13.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric bicycle in which a device driven by an electric motor is arranged in parallel with a bicycle driven by a foot pedal.

[0002]

2. Description of the Related Art A conventional electric bicycle does not have a circuit for automatically cutting off the electric current of the electric motor when the rotation of the wheels is overloaded, and when the overload is eliminated and the electric bicycle is restarted. It did not have a circuit to slowly start the rotation of the electric motor.

[0003]

Therefore, when the bicycle is overloaded, the electric motor may be burned out, and even if the bicycle is not burned out, the overload is removed and the vehicle suddenly starts up, which is dangerous. It was

[0004]

A device for driving wheels by a foot pedal, a battery for a power supply, a wheel driving electric motor, a conduction mechanism for transmitting the rotation of the electric motor to the wheels, and a motor control for controlling the rotation of the electric motor. In an electric bicycle provided with a device, a triangular wave oscillating circuit, a speed command circuit, a comparison circuit for inputting and comparing the output signals of the triangular wave oscillating circuit and the speed command circuit to the electric motor control device, and a comparison circuit A pulse width modulation circuit that modulates the pulse width with an output signal and a motor drive circuit that receives the output signal of the pulse width modulation circuit to control the current of the motor are provided, and the overcurrent detection cutoff circuit is provided in the motor drive circuit. And a slow starting circuit is provided in the speed command circuit.

[0005]

[Operation] The electric current of the electric motor is chopper-controlled by the electric motor drive circuit in response to the speed command signal by the accelerator operation, and when the overcurrent flows in the electric motor, the electric current is cut off, and when the electric motor is started and restarted. Since the rotation is gently started up, the electric motor is not burned out, and there is no danger of a sudden start of the bicycle, which is safe.

[0006]

Embodiments of the present invention will now be described with reference to the drawings. FIG. 1 is a block diagram of an embodiment of the present invention. In FIG. 1, an electric bicycle 1 of the present invention is a large crankshaft sprocket 4b fixed to a crankshaft 4a of foot pedals 2a and 2b as a drive device 8 for a wheel 3 by a foot pedal.
And a small axle sprocket 3b mounted on the hub 3a of the wheel 3 via a not-shown one-way clutch, and the large crankshaft sprocket 4b and the small axle sprocket 3 are provided.
A chain 7a is stretched over b. A small motor sprocket 6b fixed to an electric motor shaft 6a of the electric motor 6 as a wheel drive electric motor 6 and a transmission mechanism 9 to the wheel 3 and a large sprocket wheel attached to the hub 3a of the wheel 3 via a one-way clutch (not shown). 3c is provided, and a chain 7b is stretched over the electric motor shaft sprocket 6b and the large axle sprocket 3c.

A block diagram of an electric motor control device for controlling the rotation of the electric motor 6 is shown in FIG. In FIG. 2, a triangular wave oscillating circuit 12 for generating and outputting a PWM triangular wave and a speed command signal are output to the electric motor control device 11 in proportion to the rotation angle of an accelerator (not shown) provided on the handle 10 of the bicycle. Further, a speed command circuit 13 for stopping the speed command signal when the brake is applied is provided in parallel, and a comparison circuit 14 for inputting the triangular wave and the speed command signal is provided. The operation portion of the accelerator is formed on a rotary lever or a rotary knob. Next, the comparison circuit 14
Is provided with a pulse width modulation circuit 15, and an electric motor drive circuit 16 for inputting the output signal of the pulse width modulation circuit 15 to control the current of the electric motor 6 is provided.

The motor drive circuit 16 is provided with an overcurrent detection cutoff circuit 16a formed to detect an overcurrent of the motor 6 and input the signal to the pulse width modulation circuit 15.
A slow start circuit 13 for gradually increasing the starting current in the speed command circuit 13 at the time of starting the electric motor 6 and at the time of restarting the electric motor 6 whose current is interrupted by the brake and overcurrent.
It is configured by providing a. Further, in FIG. 1, a battery 5 serving as a power source for the electric motor 6 and the control device 11 is provided.

The operation of one embodiment of the present invention constructed as above will be described. In FIG. 1, when the foot pedals 2a, 2b are operated in the rotation direction of arrow A, the large crankshaft sprocket 4b fixed to the crankshaft 4a rotates in the forward direction of arrow A, and the chain 7a causes the small axle sprocket 3b to move in the direction of arrow. The hub 3a rotates in the forward direction of B and rotates in the forward direction of arrow B via a one-way clutch (not shown). As a result, the wheels 3 rotate in the forward direction indicated by arrow B, and the bicycle moves forward.

1 and 2, when a power switch (not shown) is closed, the triangular wave oscillating circuit 1 of the motor controller 11 is closed.
A PWM triangular wave is output from 2 and input to the comparison circuit 14. In this state, there is no input from the speed command circuit 13 to the comparison circuit 14, so there is no output from the comparison circuit 14. When a driver rotates an accelerator (not shown) to a starting position, the speed command circuit 13 outputs a required speed command signal. The speed command signal is input to the comparison circuit 14 and compared with the triangular wave of the triangular wave oscillation circuit 12 to output the comparison circuit output signal 17 shown in FIG.
To enter.

The output from the pulse width modulation circuit 15 is input to the electric motor drive circuit 16 to drive the electric motor 6 by passing an electric motor current 18 shown in FIG. 3 (b). At this time, the rotation of the electric motor slowly rises due to the action of the slow start circuit 13a provided in the speed command circuit 13. The rotation of the motor shaft 6a causes the motor shaft sprocket 6b to rotate, and the chain 7b causes the large axle sprocket 3c to rotate in the forward direction of arrow B, and the hub 3a to rotate in the forward direction of arrow B via a one-way clutch (not shown). As a result, the wheels 3 rotate in the forward direction indicated by arrow B, and the bicycle moves forward.

When the accelerator is further rotated to increase the speed, the pulse width of the comparison circuit output signal 17 shown in FIG. 3 (a) increases, the motor current shown in FIG. 3 (b) increases, and the rotation of the motor increases. Bicycle speed increases. FIG. 3 (b)
As shown in FIG. 3, an overload acts on the electric motor, an overcurrent 19 flows, and the overcurrent detection cutoff circuit 16a outputs an overcurrent detection pulse signal 20 shown in FIG.
5, and the pulse width modulation circuit output signal 21 is stopped in the middle of the pulse width as indicated by 21a in FIG. 3 (d).
Therefore, this state is repeated until the electric motor current 18 is cut off and the overload is eliminated. When the overload is eliminated, the drive pulse signal returns to a normal state. Speed command circuit 13
Since the rotation of the electric motor 6 gradually rises by the slow start circuit 13a provided in the bicycle, the bicycle does not suddenly start.

When the brake is applied, the speed command circuit 1
Since the speed command signal output from No. 3 is stopped, the signal input to the comparison circuit 14 is only the triangular wave output from the triangular wave oscillation circuit 12, so there is no output from the comparison circuit 14. Therefore, the electric motor current 18 is cut off.
When the brake is released, the signal corresponding to the rotation angle of the accelerator output from the speed command circuit 13 is restored and the slow start circuit 13a provided in the speed command circuit 13 causes the rotation of the electric motor 6 to slowly rise, so that the bicycle suddenly starts. There is no.

[0014]

Since the electric bicycle of the present invention has the above-mentioned structure and operation, it does not burn the electric motor when the wheel is overloaded and does not suddenly start when it is restarted. Therefore, there are excellent effects such as safety.

[Brief description of drawings]

FIG. 1 is a configuration diagram of an embodiment of an electric bicycle of the present invention.

FIG. 2 is a block diagram of an embodiment of an electric motor control device provided in the electric bicycle of the present invention.

FIG. 3 is an explanatory view of the operation of FIG. (A) is a comparison circuit output signal, (b) is a motor current, (c) is an overcurrent detection signal,
(D) is a pulse width modulation circuit output signal.

[Explanation of symbols]

 1 Electric bicycle 2a, 2b Foot pedal 3 Wheel 3a Hub 3b Axle small sprocket 3c Axle large sprocket 4a Crankshaft 4b Crankshaft large sprocket 5 Battery 6 Electric motor 6a Electric motor shaft 6b Electric motor small sprocket 7a, 7b 9 Mechanism 8 Drive device 10 Handle 11 Motor Control Device 12 Triangular Wave Oscillation Circuit 13 Speed Command Circuit 13a Slow Start Circuit 14 Comparison Circuit 15 Pulse Width Modulation Circuit 16 Motor Drive Circuit 16a Overcurrent Detection Cutoff Circuit 17 Comparison Circuit Output Signal 18 Motor Current 19 Overcurrent 20 Overcurrent Detection pulse signal 21 Pulse width modulation circuit output signal 21a Pulse width modulation circuit output signal stopped midway

Claims (1)

[Claims] 1. A device for driving a wheel by a foot pedal, a battery for a power source, a wheel driving electric motor, a transmission mechanism for transmitting the rotation of the electric motor to the wheel, and an electric motor control device for controlling the rotation of the electric motor. In an electric bicycle, a triangular wave oscillating circuit, a speed command circuit, a comparing circuit for inputting and comparing output signals of the triangular wave oscillating circuit and the speed command circuit to the electric motor control device, and a pulse by the output signal of the comparing circuit. A pulse width modulation circuit for modulating the width, an electric motor drive circuit for inputting an output signal of the pulse width modulation circuit to control the electric current of the electric motor, and an overcurrent detection cutoff circuit for the electric motor drive circuit are provided. An electric bicycle characterized in that a slow start circuit is provided in the speed command circuit.