JPH0976983A - Motor assisted bicycle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power assisted bicycle in which the control constitution is simplified without using an expensive stepping-on force sensor, which is inexpensive and difficult to fail, in which assistance by a motor is achieved under the prescribed vehicle speed even when a pedal is lightly stepped with full sense of self-riding. SOLUTION: When a pedal 1 is stepped in by the human power, and the rotation of the pedal 1 is detected by a pedal number of revolution detector 12, a CPU controller 11 drives a DC motor 7 if the number of revolution is below that corresponding to the prescribed vehicle speed, and a rear wheel 6 is driven by the driving force and assists the human power.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrically assisted bicycle that travels using human power as a main drive source and the rotational force of a motor driven by a battery power source as an auxiliary drive source.

[0002]

2. Description of the Related Art As a conventional power-assisted bicycle of this type, a pedaling force sensor for detecting the force when the pedal is stepped on by a human is mounted, and a person pedals to run the vehicle, resulting in a large load. It is known that the motor is driven when the torque detected by the pedaling force sensor exceeds a predetermined value, and the rotational force of the motor is assisted as an auxiliary drive source.

[0003]

However, in the above-mentioned conventional electrically assisted bicycle, since the torque is detected by using the pedal force sensor, the structure for control becomes complicated, and it is easy to break down. The sensor itself is expensive, and the cost is high as a whole. Also, the motor assists only when the torque detected by the pedal force sensor exceeds a predetermined value, and when the pedal below that is lightly depressed, the assist is not performed,
Therefore, there was no sense of self-propelling. The present invention has been made to solve the above-mentioned problems, does not use a pedaling force sensor, and therefore,
The structure for control is simple, it is hard to break down, and it is inexpensive because it does not require an expensive pedal force sensor.Moreover, even if the pedal is lightly depressed, the motor assists if the vehicle speed is less than the prescribed speed. The purpose is to provide an electrically assisted bicycle full of running sensations.

[0004]

In order to achieve the above object, the present invention provides an electric power assisted bicycle which uses human power as a main drive source and uses the rotational force of a motor driven by a battery power source as an auxiliary drive source. When the rotation of the pedal is detected by the drive mechanism that drives the traveling wheel by driving the pedal and / or the motor to which the pedal is applied, the pedal rotation speed detection means that detects the rotation speed of the pedal, and the pedal rotation speed detection means. And a control means for driving the motor to assist human power when the rotation speed is less than a predetermined vehicle speed. In this configuration, when the pedal rotation speed is detected by the pedal rotation speed detection means by pedaling the pedal manually, regardless of the magnitude of the pedaling force, if the rotation speed is less than the predetermined vehicle speed, the control is performed. The means drives the motor to assist the driving of the traveling wheels and assist human power. If the pedal is not depressed,
If the motor does not assist and the pedal rotation speed is equal to or higher than a predetermined vehicle speed, the vehicle travels only by human power.

Further, it is assumed that a motor rotation speed detection means for detecting the rotation speed of the motor is further provided, and the control means drives and controls the motor according to the motor rotation speed detected by the motor rotation speed detection means. You can In this configuration, when the rotation speed of the pedal increases (below a predetermined vehicle speed), the detected motor rotation speed also increases, the motor is drive-controlled accordingly, and the assist effect follows the vehicle speed. .

Further, the control means causes the motor to be driven by the pedal even when the rotation speed of the pedal detected by the pedal rotation speed detecting means is equal to or higher than a predetermined vehicle speed or less than the predetermined vehicle speed. Is detected,
The motor may act as a generator and the generated power may be used to control the battery. In this configuration, the battery is charged with the remaining power when human power is available, without introducing a complicated structure.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram of a configuration for controlling an electrically assisted bicycle, and FIG. 2 is a configuration diagram of a drive mechanism of the electrically assisted bicycle. A pedal 1 for applying human power, which is a main drive source, to the electrically assisted bicycle is connected to a sprocket 2 and further connected to a rear wheel sprocket 4 via a chain 3. This sprocket 4 drives a rear wheel 6 via a one-way clutch 5. The output shaft of the DC motor 7 as an auxiliary drive source is connected to the sprocket 8 and further connected to the rear wheel sprocket 10 via the chain 9. The sprocket 10 assist-drives the rear wheels 6 via the one-way clutch 5.

Further, the control CPU controller 11
The (control means) receives signals from the pedal rotation speed detector 12 that detects the rotation speed of the pedal 1, the pulse detector 13 that detects a pulse proportional to the rotation speed of the motor 7, and the like.
The drive of the C motor 7 is controlled. The battery 14 is a power source for driving the DC motor 7. Then, in the CPU controller 11, only when the pedal rotation speed detector 12 detects the rotation of the pedal 1 and the rotation speed is less than a predetermined vehicle speed,
The DC motor 7 is driven to assist human power, and
The DC motor 7 is drive-controlled according to the motor rotation speed detected by the pulse detector 13. When the CPU controller 11 determines that the human power is available, the CPU controller 11 causes the DC motor 7 to act as a generator and charges the battery 14 with the generated power.

The one-way clutch 5 interposed between the pedal 1 side, the output shaft side of the DC motor 7 and the rear wheel 6 provides the rotational force of the rear wheel when the pedal 1 is depressed and the sprocket 4 is rotationally driven. When the DC motor 7 is rotationally driven and the sprocket 10 is rotationally driven, it has a function of transmitting the rotational force to the rear wheel 6, and further, the pedal 1 of the sprocket 4 is depressed. When the rotation speed is higher than the rotation speed of the sprocket 10 by the DC motor 7, the DC motor 7 is rotated along with the depression of the pedal 1. Since the DC motor 7 is mounted in parallel with a vertical frame (not shown) below the saddle of the bicycle, its output shaft is a sprocket rotatably supported by a horizontal shaft via a bevel gear mechanism. The rotational force is transmitted to 8.

Next, the control operation of the CPU controller 11 of the thus-structured electrically assisted bicycle will be described with reference to the flowchart of FIG. CPU
The controller 11 checks whether a control switch (not shown) is ON (# 1), and if it is OFF,
The bicycle is driven by human power (# 7) without assisting by the motor. If the control switch is turned on, it is checked whether the pedal is rotated based on the detection signal from the pedal rotation detector 12 (# 2). As a result, if the pedal rotation is not detected, the processing procedure is # 1.
If the pedal rotation is detected, that is, if the pedal is stepped on manually, then the detection signal from the pulse detector 13 is checked (# 3). If the pedal is stepped on by human power, the DC motor 7 is rotating, so that the detection signal has a value corresponding to the vehicle speed and functions as a vehicle speed sensor.

Here, the detection signal from the vehicle speed sensor is used to check whether the vehicle speed is lower than a predetermined speed (for example, 32 Km / h).
1 specifically calculates what the vehicle speed is (# 4). Next, based on the motor current of the DC motor 7 and the like, it is calculated whether or not there is a surplus power more than the torque required for traveling in the human power on the pedal 1 (# 5). This can be seen from the fact that the motor current is proportional to the load torque.
If there is no remaining power, the CPU controller 11 drives the DC motor 7 to drive the bicycle by manpower + motor to assist the motor (# 6). Further, in # 3 above, when the vehicle speed is equal to or higher than a predetermined speed, the assist operation by the motor is not performed and the bicycle is manually driven (#
Driven according to 7). In that case, and when it is determined that there is a spare capacity in # 5, the charging operation is started (# 8). In this charging operation, the DC motor 7 acts as a generator, and the generated power is regenerated in the battery 14 to be charged.

The DC motor 7 in # 6 may be driven in response to the detection signal from the pulse detector 13, which is necessary according to the speed at which the pedal 1 is depressed and rotated. The generated torque is controlled so as to be generated.

FIG. 4 shows an example of running control of the electrically assisted bicycle according to this embodiment. The motor force is output according to the number of revolutions of the pedal 1, and the charging is started from the time when the remaining force is generated. In this way, the battery 14 can be charged while the vehicle is traveling, which has the effect of extending the battery traveling. However, when the vehicle speed exceeds a specified value on the downhill,
Normally, the pedal 1 is not stepped on (that is, it is not rotated), so the motor is not driven and the battery is not charged. In this case, the rotation of the rear wheel 6 is used to rotate the DC motor 7 to regenerate electric power, which makes the drive transmission mechanism complicated and expensive, which is not economical.

According to the electrically assisted bicycle of this embodiment,
A pedal is lightly pedaled by a simple control configuration using a pedal rotation detector 12 and a pulse detector 13 that detect an inexpensive rotation speed without requiring a pedaling force sensor that detects a pedaling force (torque) as in the conventional case. It is possible to perform assist control by the motor even when the vehicle is traveling at a low speed by stepping on 1. Therefore, it is possible to reduce the cost of the device, reduce the number of breakdowns, and provide a bicycle full of the feeling of being self-propelled.

The present invention is not limited to the configuration of the above embodiment, and various modifications can be made. For example, although the speed switching mechanism is not shown, it may be mechanically performed. Alternatively, the battery 14 may be charged by stepping on the pedal 1 with the stand upright.

[0016]

As described above, according to the electrically assisted bicycle of the present invention, when the pedal is manually depressed, the rotation of the pedal is detected, and the motor is driven when the rotation speed is less than the predetermined vehicle speed. This assists the human drive of the traveling wheels. Since assist control is possible without the need for a pedaling force sensor, the control configuration is simple, it is not prone to failure, and it is inexpensive.Moreover, even if the pedal speed is lightly pedaled, the motor assists at a speed less than the specified speed. It will be full of the feeling of running. Further, by controlling the drive of the motor in accordance with the number of rotations of the motor, when the number of rotations of the pedal increases, the detected number of rotations of the motor also increases, and the drive of the motor is controlled accordingly. Can be effectively obtained by following the vehicle speed. Further, when the number of rotations of the pedal is equal to or higher than a predetermined vehicle speed, the motor is caused to act as a generator, and the battery is controlled to be charged.
When there is extra power due to human power, the battery can be charged with the extra power.

[Brief description of drawings]

FIG. 1 is a block diagram of a control configuration of an electrically assisted bicycle according to an embodiment of the present invention.

FIG. 2 is a configuration diagram of a drive mechanism of an electrically assisted bicycle.

FIG. 3 is a flowchart of control.

FIG. 4 is a diagram showing an example of travel control.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 pedal 6 rear wheel 7 DC motor 11 CPU controller (control means) 12 pedal rotation speed detector 13 pulse detector 14 battery

Claims (3)

[Claims] 1. In an electrically assisted bicycle which uses human power as a main drive source and uses a rotational force of a motor driven by a battery power source as an auxiliary drive source, a traveling wheel is driven by driving a pedal or / and a motor to which human power is applied. When the rotation of the pedal is detected by the pedal rotation speed detection means for detecting the rotation speed of the pedal, the pedal rotation speed detection means for detecting the rotation speed of the pedal, and the rotation speed is less than a predetermined vehicle speed. An electrically assisted bicycle comprising: a control unit that drives the motor so as to assist human power. 2. A motor rotation speed detection means for detecting the rotation speed of the motor is further provided, and the control means drives and controls the motor according to the motor rotation speed detected by the motor rotation speed detection means. The electrically assisted bicycle according to claim 1, wherein: 3. The control means controls the motor to operate even when the rotation speed of the pedal detected by the pedal rotation speed detecting means is equal to or higher than a predetermined vehicle speed or less than a predetermined vehicle speed. 3. The electric motor according to claim 1, wherein when the state of being driven by a pedal is detected, the motor is made to act as a generator and the generated electric power is used to charge the battery. Assisted bicycle.