Electric bicycle

Abstract

This invention provides an electric-powered bicycle that uses only pedal input as its power source, maintaining the same riding feel as a regular bicycle while enabling highly efficient riding, and also reducing weight and cost. [Solution] The system comprises a pedal 20, a crank 18 connected to the pedal 20, wheels 14 and 16, a generator 30 to which the rotational force of the crank shaft 19 of the crank 18 is input, and a drive motor 34 to which the power generated by the generator 30 is input without going through a battery and rotates the wheels 14 and 16.

Description

Technical Field

[0001] The present invention relates to a bicycle driven by an electric motor.

Background Art

[0002] In recent years, many electric assist bicycles have emerged. Basically, an electric assist bicycle is driven by a driver pedaling and transmitting the rotational force of the pedals to the wheels. Additionally, it is equipped with a motor that, as an auxiliary, transmits the driving force of the motor to the wheels using electric power from a battery to assist in running.

[0003] There are also configurations in which the electric power stored in the battery is generated by the rotational force of the pedals as described below.

[0004] For example, Patent Document No. 1 (Japanese Patent Application Laid-Open No. 2021-62640) discloses a configuration in which the rotation of the pedals is transmitted to an alternator for power generation, the DC output power is stored in a battery, the motor is driven by the power from the battery, and the driving force of the motor rotates the wheels.

[0005] In addition, Patent Document No. 2 (Japanese Patent No. 7387218) discloses a specific small prime mover-equipped bicycle including a generator that generates power by the rotation of the pedals, a battery that stores the power generated by the generator, and a motor that rotationally drives the wheels with the power of the battery.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0007] The bicycles described in Patent Documents 1 and 2 above are electric bicycles in which the wheels are rotated by a motor driven by electricity from a battery, and electricity can be generated by the rotation of the pedals and stored in the battery. In other words, these should be called electric scooters rather than bicycles, and according to the riders who actually ride them, there is a problem that the pedal rotation speed and the actual riding speed are not linked, so they cannot be ridden with the same feeling as a bicycle. Another challenge is that the weight increases due to the inclusion of the battery.

[0008] Therefore, the present invention aims to solve the above problems by providing an electric-powered bicycle that uses only pedal input as a power source, enables highly efficient riding while maintaining the same riding feel as a regular bicycle, and also reduces weight and cost. [Means for solving the problem]

[0009] The electric-powered bicycle according to the present invention is characterized by comprising: pedals; a crank connected to the pedals; wheels; a generator to which the rotational force of the crank is input; and a drive motor to which the power generated by the generator is input without going through a battery and which rotates the wheels. In this configuration, the only power source is pedal input, and the electricity generated by pedaling is directly input to the drive motor without going through a battery, so the rotation of the pedals and the driving force from the drive motor are linked. In other words, pedaling faster increases the speed of the bicycle, pedaling slower decreases the speed of the bicycle, and stopping pedaling stops the bicycle. Thus, it can be driven with the same riding feel as a normal bicycle. Furthermore, because it does not have a chain, drive gears, etc., it enables highly efficient driving, and because it does not have a chain, drive gears, or battery, it is also lighter and costs are reduced.

[0010] Furthermore, an internal gearbox is provided between the crank and the generator. With this configuration, the driver can adjust the pedaling load (crankshaft rotation speed, rotational torque) by switching the internal gear hub.

[0011] Furthermore, the generator is an AC generator, the drive motor is an AC motor, and the system is characterized by comprising an AC / DC converter that converts the AC power generated by the AC generator into DC power, and an inverter that converts the DC power converted by the AC / DC converter into AC power with controlled frequency and voltage and outputs it to the drive motor. With this configuration, the rotational speed and torque of the drive motor can be controlled by the inverter.

[0012] Furthermore, the device is characterized by comprising at least one of the following: a heart rate sensor for measuring the driver's heart rate; a gradient sensor for measuring the road gradient; a cadence sensor for measuring the rotational speed of the crank; a torque sensor for measuring the rotational torque of the crank; and a vehicle speed sensor; and a control circuit that receives the measured values ​​from each of the sensors and controls the inverter to control the frequency and voltage of the AC power based on the measured values ​​from each of the sensors. This configuration allows for the control of the bicycle's speed and torque during riding, based on factors such as heart rate, road gradient, crank rotation speed, crank rotation torque, and vehicle speed.

[0013] Furthermore, the control circuit is provided to communicate data with a communication terminal held by the driver, transmits the measured values ​​measured by each of the sensors to the communication terminal, and controls the inverter to control the frequency and voltage of the AC power based on instructions from the communication terminal. With this configuration, the driver can view each measurement transmitted to the communication terminal, and can also manually instruct and control the bicycle's speed and torque during riding to make it easier for the driver to ride. [Effects of the Invention]

[0014] According to the present invention, it is possible to provide an electric drive bicycle that uses only pedal input as a power source, enables high-efficiency running while maintaining the same running feeling as a general bicycle, and can also reduce weight and cost.

Brief Description of the Drawings

[0015] [Figure 1] It is a side view showing the overall configuration of an electric drive bicycle. [Figure 2] It is an explanatory view showing a configuration in which a crankshaft is directly connected to a generator. [Figure 3] It is an explanatory view showing a configuration in which a crankshaft is connected to a generator via a belt. [Figure 4] It is an explanatory view showing a configuration in which an internal transmission is provided between a crankshaft and a generator. [Figure 5] It is a block diagram showing the control system of the entire electric drive bicycle. [Figure 6] It is a block diagram showing the configuration of a mobile communication terminal.

Embodiments for Carrying Out the Invention

[0016] Hereinafter, the electric drive bicycle in the present embodiment will be described based on the drawings. Fig. 1 shows the overall configuration of an electric drive bicycle. The electric drive bicycle 10 includes a handle 12 attached to the frame 11, a saddle 13 attached to the frame 11, a front wheel 14, and a rear wheel 16.

[0017] The front wheel 14 is rotatably mounted at the tip of a front fork 15 that extends downward from a head tube 11a constituting the frame 11. The rear wheel 16 is rotatably mounted at the tip where a seat stay 11b and a chain stay 11c constituting the frame 11 intersect.

[0018] At the point where the down tube 11d, seat tube 11e, and chainstay 11c that make up the frame 11 intersect, a crank 18 and a pedal 20 attached to the end of the crank 18 are provided.

[0019] The crankshaft 19 of the crank 18 is connected to the rotating shaft of the generator 30. For example, as shown in Figure 2, the crankshaft 19 may be directly connected to the generator 30. Alternatively, as shown in Figure 3, a pulley 33 may be provided on the crankshaft 19, and a belt 32 may be used to connect the pulley 33 to the rotating shaft of the generator 30, thereby transmitting the rotation of the crankshaft 19 to the generator 30.

[0020] Furthermore, as shown in Figure 4, an internal transmission 22 may be placed between the crankshaft 19 of the crank 18 and the rotating shaft of the generator 30. In this case, it is preferable that the crankshaft 19, the internal transmission 22, and the rotating shaft of the generator 30 are arranged in a straight line. The internal gear shift 22 can be switched by operating the shift knob 25, which is provided on the steering wheel 12.

[0021] A drive motor 34 is positioned at the center of the rear wheel 16, and the rear wheel 16 is rotated by the drive motor 34. Furthermore, the drive motor 34 may be provided not only on the rear wheel 16 but also on the front wheel 14 to create a two-wheel drive electric bicycle 10.

[0022] The power to drive the drive motor 34 is generated by the generator 30, which is rotated by the driver pedaling the pedal 20. The power generated by the generator 30 is supplied to the drive motor 34 without being stored in the battery.

[0023] Furthermore, in this embodiment, an AC generator is used as the generator 30. AC generators have excellent maintainability as they do not experience brush wear like DC generators. Furthermore, a three-phase AC motor is used as the drive motor 34. Three-phase AC motors are highly efficient and easy to maintain.

[0024] As described above, by eliminating the need for a chain and external derailleur, mechanical problems can be prevented, dirt and snagging of pants hems can be eliminated, and the symmetrical 16-tooth rear wheel improves left-right balance and riding comfort.

[0025] Figure 5 shows a block diagram of the control system, and the control of the electric-driven bicycle 10 in this embodiment will be described below. The AC power generated by the AC generator 30 is converted to DC power by the AC / DC converter 40. The DC power is input to the inverter 42, which controls the frequency and voltage of the AC power that is then input to the three-phase AC motor 34.

[0026] Furthermore, a control circuit 44 is provided to control the inverter 42. The control circuit 44 controls the inverter 42 so that the three-phase AC motor 34 achieves an appropriate rotational speed and rotational torque based on the measured values ​​of each sensor, which will be described later.

[0027] The electric-powered bicycle 10 shown in Figure 5 is equipped with a heart rate sensor 50 for measuring the rider's heart rate, a gradient sensor 52 for measuring the road gradient, a cadence sensor 54 for measuring the rotation speed of the crank 18's axis of rotation, a torque sensor 56 for measuring the rotation torque of the crank 18's axis of rotation, and a vehicle speed sensor 58 for measuring the bicycle's speed.

[0028] The heart rate sensor 50 may be mounted on the handlebars 12 to measure the heart rate from the driver's palm as they grip the handlebars 12, or it may be attached to the driver's wrist or the like. The gradient sensor 52 can be a so-called tilt sensor, and can be attached to the frame 11 or the like, or if it is a semiconductor chip type tilt sensor, it may be mounted on the printed circuit board that makes up the control circuit 44. The cadence sensor 54 may be attached to the crank 18, or it may be attached to the rider's foot. The torque sensor 56 can be mounted on the rotating shaft of the crank 18. The vehicle speed sensor 58 can be mounted on the rotating shaft of the front wheel 14 or the rear wheel 16.

[0029] It should be noted that it is not necessary to attach all of the above-mentioned sensors to the electric-powered bicycle 10; it is preferable to attach at least one of the above-mentioned sensors.

[0030] The control circuit 44 is configured to communicate data with each of the aforementioned heart rate sensor 50, gradient sensor 52, cadence sensor 54, torque sensor 56, and vehicle speed sensor 58. Data communication between the control circuit 44 and each sensor may be wired or wireless.

[0031] Furthermore, the control circuit 44 is configured to communicate with a mobile communication terminal 60 (such as a smartphone or tablet) carried by the driver.

[0032] For example, if the control circuit 44 determines from the heart rate sensor 50 that the heart rate has risen above a preset threshold, it needs to reduce the torque applied to the pedals 20 because this would increase the strain on the heart. Therefore, the control circuit 44 performs control to reduce the power generation load and, at the same time, performs control to reduce the driving speed while fine-tuning the driving torque of the drive motor 34 while maintaining it to a near-perfect level.

[0033] Furthermore, if the control circuit 44 determines from the measurement value from the gradient sensor 52 that the road is on an uphill slope, it increases the drive torque of the drive motor 34 according to the incline angle and executes control to reduce the travel speed. If the control circuit 44 determines from the measurement value from the gradient sensor 52 that the road is on a downhill slope, it reduces the drive torque of the drive motor 34 according to the incline angle and executes control to reduce the travel speed. If the control circuit 44 determines that the road is flat based on the measurement from the gradient sensor 52, it performs control to maintain the drive torque and travel speed of the drive motor 34 at a constant level.

[0034] Furthermore, if the control circuit 44 determines that the cadence measured by the cadence sensor 54 is higher than a preset upper threshold, it determines that there is room for pedal input and executes control to increase the power generation load, as well as increasing the rotational speed of the drive motor 34, and controls it to fine-tune the drive torque in accordance with the change in gradient while maintaining it almost constant. If the control circuit 44 determines from the cadence measurement from the cadence sensor 54 that the cadence is lower than a lower threshold, it executes control to reduce the power generation load due to pedal input, lowers the rotation speed of the drive motor 34, and controls it to make fine adjustments in accordance with the change in gradient while maintaining the drive torque to almost the same extent.

[0035] Furthermore, if the control circuit 44 determines from the torque sensor 56 that the pedal input torque is greater than a preset threshold, it determines that the driver has sufficient physical strength and increases the rotational speed of the drive motor 34 while maintaining a high power generation load, and controls the drive torque to make fine adjustments according to the road gradient. If the control circuit 44 determines from the torque sensor 56 that the pedal input torque is smaller than a preset lower threshold, it determines that the rider is running out of physical strength, and reduces the power generation load, lowers the rotation speed of the drive motor 34, and controls the drive torque to make fine adjustments according to the road gradient.

[0036] Furthermore, if the control circuit 44 determines that the speed measured by the vehicle speed sensor 58 exceeds a preset threshold, it controls the rotation speed and driving torque of the drive motor 34 to decrease, and also notifies the driver that the driving is dangerous. As a method of reporting, the control circuit 44 transmits a message to the driver's mobile communication terminal 60 indicating that the driving is dangerous. Upon receiving this message, the mobile communication terminal 60 displays a message to the driver indicating that the driving is dangerous on its display unit (such as an LCD screen).

[0037] Figure 6 shows a block diagram of a mobile communication terminal. The mobile communication terminal 60 comprises a control unit 62, which is composed of a CPU and the like, that controls the overall operation of the mobile communication device 60; a communication unit 64 for communicating with the control circuit 44; a display unit 66, which is composed of an LCD screen and the like; and a storage unit 68, which is composed of a memory and the like.

[0038] The memory unit 68 stores the driving application P1, which is a program read and executed by the control unit 62. The operation of the driving app P1 is as follows: When the driving application P1 is executed, the control unit 62 of the mobile communication terminal 60 instructs the control circuit 44 to transmit each measurement value collected by the control circuit 44, and receives each measurement value from the control circuit 44. The control unit 62 can display each received measurement value on the display unit 66. The display on the display unit 66 may show only numbers, or it may show a graph or the like. The control unit 62 can store each received measurement value and save it as driving data in the storage unit 68.

[0039] Furthermore, the driving application P1 can also be linked with the GPS function and map application built into the mobile communication terminal 60 through the operation of the control unit 62, and the driving route can be displayed on the map in the map application.

[0040] Furthermore, the driving application P1 allows the driver to output driving instructions to the control circuit 44. When the driving application P1 is executed, the control unit 62 of the mobile communication terminal 60 displays the measured values ​​collected by the control circuit 44 on the display unit 66 as described above, and also displays the driving speed adjustment unit 67 and the torque adjustment unit 69 on the display unit 66. The driving speed adjustment unit 67 and the torque adjustment unit 69 may be displayed in any format.

[0041] When the driver operates the speed adjustment unit 67 and torque adjustment unit 69 displayed on the display unit 66, the control unit 62 of the mobile communication terminal 60 outputs a control signal to the control circuit 44 so that the speed and torque are set by the driver. Upon receiving this control signal, the control circuit 44 controls the inverter 42 to adjust the rotational speed and torque of the drive motor 34 so that the speed and torque set by the driver are achieved.

[0042] Furthermore, the control in the control circuit 44 may employ AI-based control that enables optimal control based on past measurements from each sensor. [Explanation of symbols]

[0043] 10 Electric bicycles 11 frames 11a head tube 11b Seatstay 11c chainstay 11d downtube 11e seat tube 12 handles 13 Saddle 14 Front Wheel 15 Front Fork 16 Rear wheels 18 Crank 19 Crank axle 20 pedals 22 Internal gear hub 25 Shift knob 30. Generator (AC generator) 32 belts 33 Pulley 34. Drive motor (three-phase AC motor) 42 Inverters 44 Control circuits 50 Heart rate sensors 52 Gradient Sensor 54 Cadence Sensor 56 Torque Sensor 58 Vehicle speed sensor 60 Mobile communication terminals 62 Control Unit 64 Communications Department 66 Display section 67. Driving speed adjustment unit 68 Memory section 69 Torque adjustment section P1 Driving App

Claims

1. Pedals and, The crank connected to the pedal, Wheels and, A generator to which the rotational force of the crankshaft of the aforementioned crank is input, An electric-powered bicycle comprising: a drive motor that rotates the wheels using electricity generated by the aforementioned generator, which is input without going through a battery.

2. The electric-driven bicycle according to claim 1, characterized in that an internal gear hub is provided between the crankshaft and the generator.

3. The aforementioned generator is an AC generator, The aforementioned drive motor is an AC motor, An AC / DC converter that converts AC power generated by the aforementioned AC generator into DC power, An electric drive bicycle according to claim 1 or 2, further comprising: an inverter that converts the DC power converted by the AC / DC converter into AC power with controlled frequency and voltage and outputs it to the drive motor.

4. At least one of the following: a heart rate sensor for measuring the driver's heart rate, a gradient sensor for measuring the road gradient, a cadence sensor for measuring the rotational speed of the crank, a torque sensor for measuring the rotational torque of the crank, and a vehicle speed sensor, The electric-driven bicycle according to claim 3, further comprising: a control circuit that receives measured values ​​measured by each of the sensors and controls the inverter to control the frequency and voltage of the AC power based on the measured values ​​measured by each of the sensors.

5. The aforementioned control circuit is It is equipped to enable data communication with the driver's mobile communication device. The electric-driven bicycle according to claim 4, characterized in that each of the sensors transmits the measured values ​​to the mobile communication terminal, and controls the inverter to control the frequency and voltage of the AC power based on instructions from the mobile communication terminal.

6. When the vehicle speed sensor is provided, The aforementioned control circuit is If the vehicle speed measured by the vehicle speed sensor exceeds a preset threshold, a message indicating that the driving is dangerous is transmitted to the mobile communication terminal. The aforementioned mobile communication terminal is The electric-powered bicycle according to claim 5, characterized in that it displays a message indicating that the riding is dangerous.

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