JP3164098U - Power control device for electric bicycle - Google Patents

Abstract

A power control device for an electric bicycle, which efficiently outputs auxiliary power and stabilizes the bicycle traveling on various road surface conditions. An electric bicycle includes a frame and a motor. The frame has a drive gear unit. The motor is used as an auxiliary drive for the electric bicycle. The power control device includes a sensor and a controller. The sensor is disposed at a position close to the drive gear unit on the frame, and generates a signal by sensing the deformation amount of the position described above. The controller is electrically connected to the sensor and the motor, and adjusts the output power of the motor by receiving a signal from the sensor. [Selection] Figure 4

Description

  The present invention relates to an electric bicycle, and more particularly to a power control device for an electric bicycle.

  While environmental protection problems around the world are becoming more and more serious and energy consumption is continuously updated, it is no longer possible to make transportation more environmentally friendly and realize more energy conservation. There is no problem. The use of bicycles as a means of transportation can be adapted to the current situation described above, but conventional bicycles generate power by stepping in manually and control the bicycle when traveling on an uphill or uneven road surface. Is relatively limited and very inconvenient to use because it requires a relatively large force. Therefore, the electric bicycle is one of the transportation means selected by many people.

  A general electric bicycle is constructed by adding a motor, a sensor, and a battery used to drive the motor to a conventional bicycle, and senses the state by the sensor, outputs the power by the motor, and drives the wheel. In addition to stepping on with its own power, it is possible to drive the bicycle synchronously by the auxiliary power of the motor.

  The sensor is usually built in the BB shell of the bicycle in order to sense the torque generated when the crank arm of the bicycle is depressed. When the electric bicycle runs on a flat road surface, the user can step on the crank arm relatively easily. Since the torque of the crank arm sensed by the sensor at this time is relatively small, the motor outputs a relatively small auxiliary power. When an electric bicycle runs uphill, the user must step on the crank arm with a relatively large force on both feet. At this time, since the torque of the crank arm detected by the sensor is relatively large, the motor outputs relatively large auxiliary power to help the bicycle advance. As described above, when riding an electric bicycle, it is possible to not only waste physical strength and simplify the operation, but also achieve the purpose of environmental protection.

  The electric bicycle described above adjusts the auxiliary power from the motor based on the magnitude of the torque of the crank arm. When a user rides a bicycle and climbs an uphill, if his / her feet are tired, the gear ratio of the bicycle can be reduced by the transmission and the crank arm can be depressed relatively easily. However, if the gear ratio is reduced, the torque of the crank arm is also reduced, but the power output from the motor is reduced. You have to step in. At this time, since the motor cannot supply any further auxiliary power, the electric bicycle cannot reliably cope with climbing uphill, which puts a burden on the user and affects the ride comfort.

  On the other hand, the speed limit of electric bicycles is restricted by law, and if the upper limit of the speed limit is reached, the auxiliary power from the motor must be interrupted. Therefore, when the current electric bicycle reaches the upper limit of the speed limit, The power curve is designed to output a minimum auxiliary power. In fact, the higher the speed, the more gradually the overall efficiency of the bicycle must be increased. In addition, more auxiliary power is required to continuously stabilize the running state, whereas the motor cannot supply power that can be handled, so the user has to step in more. Therefore, not only annoying the user, but also the advantages of the electric bicycle cannot be exhibited.

  A main object of the present invention is to provide a power control device for an electric bicycle that makes it possible to stabilize the bicycle and improve the ride comfort when traveling on various road surface conditions by efficiently outputting auxiliary power. That is.

  Another object of the present invention is to provide a power control device for an electric bicycle that makes it possible to sense the state of the bicycle at a relatively low cost.

  In order to achieve the above-described object, a power control device for an electric bicycle according to the present invention is attached to the electric bicycle. The electric bicycle includes a frame and a motor. The frame has a drive gear unit. The motor is used as an auxiliary drive for the electric bicycle. The power control device includes a sensor and a controller. The sensor is disposed near the drive gear unit on the frame, and generates a signal by sensing the amount of deformation of the position. The controller is electrically connected to the sensor and the motor and simultaneously adjusts the motor output power and efficiency curve by receiving signals from the sensor. When raising the speed of an electric bicycle to the upper limit of the speed limit by law, the motor can supply sufficient output efficiency.

  In one embodiment of the present invention, in order to accurately detect the state of the frame, a hook is provided on the frame, and a sensor is disposed on the hook.

  Due to the technical features described above, the present invention not only can efficiently output power according to various road conditions and maintain a relatively good riding comfort and stability, but also at a relatively low cost. It is possible to sense the situation.

1 is a side view showing a power control device for an electric bicycle according to an embodiment of the present invention. 1 is a side view showing a part of a back fork of a frame in a power control device for an electric bicycle according to an embodiment of the present invention. 3 is a graph illustrating chain and sensor output signals in a power control apparatus for an electric bicycle according to an embodiment of the present invention. It is a mimetic diagram showing construction of a power control device of an electric bicycle by one embodiment of the present invention. 1 is a schematic diagram illustrating an operating state of a power control device for an electric bicycle according to an embodiment of the present invention. 3 is a graph illustrating the output efficiency of a motor by a power control device for an electric bicycle according to an embodiment of the present invention.

Hereinafter, a power control device for an electric bicycle according to the present invention will be described with reference to the drawings.
(One embodiment)
As shown in FIGS. 1 and 2, a power control device 40 for an electric bicycle according to an embodiment of the present invention is attached to the electric bicycle. The electric bicycle includes a frame 10, a front wheel 12, a rear wheel 14, a drive gear unit 20, and a motor 16. The front wheel 12 is mounted on the front fork 11 of the frame 10 so that it can rotate, and the rear wheel 14 is mounted on the back fork 13 of the frame 10 so that it can rotate. In the present embodiment, the motor 16 is a BLDC motor that is mounted at the hub position of the front wheel 12 in order to rotate the front wheel 12. The back fork 13 of the frame 10 has two hooks 18. The rear wheel 14 is mounted between two hooks 18.

  The drive gear unit 20 includes a large gear unit 22, a plurality of chain wheels 24 and chains 26 having different sizes and the number of teeth. The large gear unit 22 is attached to the frame 10 so as to be rotatable, and has a number of gear plates with different numbers of teeth. The chain wheel 24 is fixed so as to overlap one side of the rear wheel 14 of the frame 10. The chain 26 is mounted so as to surround between one gear plate of the large gear unit 22 and one chain wheel 24. The user can move the bicycle by depressing the pedal 28 of the large gear unit 22 and driving the rear wheel 14 by the chain 26.

  The frame 10 further has a transmission 30. The transmission 30 adjusts the chain 26 that is mounted so as to surround the different chain wheel 24 and the gear plate of the large gear unit 22, and the gear ratio generated between the chain wheel 24 and the different number of teeth on the gear plate. The chain wheel 24 is driven with a different torque based on the above, and at the same time the rear wheel 14 is rotated to produce different rotational speeds.

  The power control device 40 includes a sensor 42 and a controller 44. In the present embodiment, the sensor 42 is a Hall sensor mounted on the frame 10 at a position close to the drive gear unit 20. In the present embodiment, the sensor 42 is disposed on one hook 18, but may be attached to a portion that can contact the frame 10. The sensor 42 generates a deformation zone in accordance with the torque when stepping on. Since the chain wheel 24 is disposed on the hook 18, when the chain wheel 24 rotates by driving the chain 26, torque generated when the large gear unit 22 is stepped is directly transmitted to the hook 18 via the chain 26 and the chain wheel 24. As a result, the structure of the hook 18 is deformed. At this time, if the drive gear unit 20 rotates the bicycle, the sensor 42 can generate a corresponding signal by sensing the deformation of the hook 18. Since the controller 44 is electrically connected to the sensor 42 and the motor 16, the controller 44 can receive a signal sensed from the sensor 42 and adjust the auxiliary power from the motor 16 based on the signal.

As described in the construction of the present invention described above, as shown in FIG. 5, the number of teeth of the large gear unit 22 is T ₁ , the number of teeth of the chain wheel 24 is T ₂ , the length of the pedal 28 is L, When the force to depress the pedal is F ₁ , the magnitude of the torque M transmitted through the chain wheel 24 is directly related to the gear ratio of the drive gear unit 20 according to the following formula, and the deformation amount of the hook 18 according to the torque M is It turns out to be directly proportional to the stepping force F ₁ .

  As shown in FIG. 3, the greater the tension of the chain 26 that drives the chain wheel 24, the higher the voltage output from the sensor 42, whereas the deformation amount of the hook 18 is the torque transmitted through the chain wheel 24. It increases according to. Therefore, as shown in FIG. 4, when the sensor 42 changes the signal in accordance with the deformation amount of the hook 18 due to such a change, the controller 44 reads the signal and reads the transmission power of the drive gear unit 20. Thus, the output power of the motor 16 can be adjusted.

  When the amount of deformation of the hook 18 sensed from the sensor 42 increases, it indicates that the torque transmitted through the chain wheel 24 is relatively large, that is, the bicycle requires a relatively large amount of power. At this time, the controller 44 can rotate the front wheel 12 by causing the motor 16 to output relatively large auxiliary power, so that the user does not need to step on the large gear unit 22 with his / her own power alone. It is possible to easily ride a bicycle by power and achieve labor saving. When the amount of deformation of the hook 18 sensed from the sensor 42 is reduced or relatively small, the torque transmitted through the chain wheel 24 is relatively small, so that the controller 44 reduces or stops the output power of the motor 16, Restore the state that the bicycle is stepped on. Since the sensor 42 is directly coupled to the frame 10 and the hook 18 to advance subsequent control by sensing the amount of deformation of the hook 18, the present invention simplifies parts, reduces costs, and accurately senses the state of the bicycle. Is possible.

The present invention can improve the power characteristics of the electric bicycle by adjusting the output characteristics of the motor, in addition to using a method of detecting the deformation amount of the hook by a sensor. As shown in C ₁ curve in Figure 6, the design of the output power of the conventional motor, when the speed of the bicycle reaches the upper limit S _H, the motor outputs a close auxiliary power to zero. When the bike reaches the upper speed limit on an uphill slope, the motor cannot supply extra auxiliary power, so the only way to maintain power is to rely on depression. In contrast, the assist power of the present invention is as shown in C ₂ curve in FIG 6, since the efficiency of the speed of the bicycle is supplied from the faster the motor if Hayakere increases, the present invention is the motor 16 to the maximum output power When reaching, the gear ratio is changed by the transmission 30, the force and deformation amount received by the hook 18 are increased, the state of the bicycle is sensed by the sensor 42, and pulse width modulation (PWM) is performed by the controller 44. Therefore, before the output characteristic of the motor 16 reaches the maximum output efficiency, it is possible not only to increase the output of the stable auxiliary power with the increase of the speed and increase the power efficiency, but also to the bicycle. It is possible to improve smoothness and comfort when riding.

  As mentioned above, this invention is not limited to the said embodiment at all, In the range which does not deviate from the meaning of invention, it can be implemented with a various form.

10: Frame 11: Front fork 12: Front wheel 13: Back fork 14: Rear wheel 16: Motor 18: Hook 20: Drive gear unit 22: Large gear unit 24: Chain wheel 26: Chain 28: Pedal 30: Transmission 40: Power control device 42: Sensor 44: Controller

Claims (9)

In the electric bicycle power control device, the electric bicycle includes a frame and a motor, the frame includes a drive gear unit, the motor is used for auxiliary driving of the electric bicycle, the power control device includes a sensor and a controller,
The sensor is disposed near the drive gear unit on the frame, and generates a signal by sensing a deformation amount of the position,
The controller is electrically connected to the sensor and the motor, and adjusts the output power of the motor by receiving a signal from the sensor;
When the speed of the electric bicycle reaches the upper limit value, the output efficiency of the motor is higher than zero.   The power control apparatus for an electric bicycle according to claim 1, wherein the frame further includes a hook, and the sensor is disposed on the hook.   The power controller for an electric bicycle according to claim 1, wherein the controller adjusts output power of the motor by pulse width modulation.   The power control apparatus for an electric bicycle according to claim 1, wherein the output efficiency of the motor increases as the speed of the electric bicycle increases. A frame having a drive gear unit;
Two wheels mounted on the frame and rotated by driving of the drive gear unit;
A motor mounted on the frame and capable of rotating one of the wheels;
A power control device having a sensor and a controller,
The sensor is disposed near the drive gear unit on the frame, and generates a signal by sensing a deformation amount of the position,
The controller is electrically connected to the sensor and the motor, and adjusts the output power of the motor by receiving a signal from the sensor;
When the speed of the electric bicycle reaches an upper limit value, the output efficiency of the motor is higher than zero.   The electric bicycle according to claim 5, wherein the frame further includes a hook, and the sensor is disposed on the hook.   The electric bicycle according to claim 5, wherein the controller adjusts output power of the motor by pulse width modulation.   6. The electric bicycle according to claim 5, wherein the two wheels are arranged in front and rear of the frame, and the motor drives the wheel located in front of the frame.   The power control apparatus for an electric bicycle according to claim 5, wherein the output efficiency of the motor increases as the speed of the electric bicycle increases.

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