Electrically assisted bicycle

Abstract

The invention relates to an electrically assisted bicycle, comprising; a rear wheel (1), a front wheel, a crankset (2) mechanically connected to the rear wheel (1), two mechanical brakes, an electric assistance motor (4) (1), supplied with electric current, from a direct current source, via a reversible inverter (5), characterized in that the electric motor (4) is a reduced motor without freewheel; the direct current source is a module (6) of supercapacitors (9), controlled by a converter (8); a pedaling torque sensor (11), and a pedaling speed sensor (12) are arranged in connection with the crankset (2); a sensor (13) for the rotational speed of the electric motor (4) is located in the axis of the drive wheel (1);a voltage sensor (15) measures the state of charge of the module (6) of supercapacitors (9), and an electronic control unit (10) ensures the operation of the converter (8) depending on the pedaling torque, the pedaling speed, the rotation speed of the electric motor (4), and the state of charge of the module (6) of supercapacitors (9). Figure for abstract: Figure 1;

Description

Title of the invention: Electrically assisted bicycle

[0001] The invention relates to an electrically assisted bicycle, or VAE, comprising a rear wheel, a front wheel, two mechanical brakes, a pedal assembly mechanically connected to the rear wheel, an electric motor used for assistance or for converting kinetic energy into electricity in generator mode, supplied with electric current from a direct current source, via a reversible inverter.

[0002] VAE generally use accumulator batteries as a source of direct current which, on the one hand, are generally heavy, and on the other hand, need a few hours to charge before use and discharge slowly, which is not favorable in the event of intense effort such as when starting or climbing a steep slope of the VAE.

[0003] It is also known from document WO 2014 / 169305 that the electric motor provides assistance to the pedals, depending on the speed imposed on the VAE and measured at the pedals.

[0004] One of the aims of the invention is to propose an EAB without a storage battery, and without external recharging.

[0005] Another aim of the invention is to propose an EAB with energy recharging by the user of the EAB.

[0006] Another aim of the invention is to propose an EAB whose energy recharge is ensured by the user according to his fatigue threshold.

[0007] The present invention relates to an electrically assisted bicycle, comprising: a rear wheel, a front wheel, a crankset mechanically connected to the rear wheel, an electric assistance motor, supplied with electric current, characterized in that: - the electric motor is a motor without a freewheel; - the electric current is supplied by a supercapacitor module controlled by a converter, - at least one pedaling torque sensor and at least one pedaling speed sensor are arranged in connection with the crankset; - a rotation speed sensor controls the rotation speed of the electric motor; - a voltage sensor measures the state of charge of the supercapacitor module; and - an electronic control unit ensures the operation of the converter according to the pedaling torque, the pedaling speed, the rotation speed of the electric motor, and the state of charge of the supercapacitor module.

[0008] The present invention relates to an electrically assisted bicycle, comprising: a rear wheel, a front wheel, two mechanical brakes, a mechanically connected crankset with the rear wheel, an electric assistance motor, supplied with electric current, characterized in that: - the electric motor is a motor without freewheel; - the electric current is supplied from a supercapacitor module controlled by a converter; - a means ensures the detection of mechanical braking; - a voltage sensor measures the state of charge of the supercapacitor module; and - an electronic control unit ensures the operation of the electric motor as a generator to recharge the energy reserve constituted by the supercapacitor module depending on the state of charge of the supercapacitor module as soon as mechanical braking is detected.

[0009] According to one embodiment, the electric motor is a reduced motor without freewheel.

[0010] According to one embodiment, the electric motor is a direct drive motor.

[0011] According to one embodiment, the electric motor is located in the hub of the rear wheel.

[0012] According to one embodiment, the electric motor is located in the hub of the front wheel.

[0013] According to one embodiment, the sensor of the rotation speed of the electric motor is located in the axis of the wheel carrying the electric motor.

[0014] According to one embodiment, the sensor of the rotation speed of the electric motor is located on the spokes of one of the wheels.

[0015] According to one embodiment, the pedaling torque sensor is integrated into the motor.

[0016] According to one embodiment, the pedaling speed sensor is integrated into the motor.

[0017] According to one embodiment, the means for detecting mechanical braking consists of at least one sensor.

[0018] According to one embodiment, the means for detecting mechanical braking consists of at least one contactor.

[0019] According to one embodiment, the mechanical connection between the crankset and the rear wheel is provided by chain, belt or cardan.

[0020] According to one embodiment, the electronic control unit is connected to at least one temperature sensor of the supercapacitor module.

[0021] According to one embodiment, the electronic control unit is connected to at least one sensor of the temperature of the electric motor.

[0022] According to one embodiment, a voltage sensor measures the state of charge of each of the supercapacitors in the supercapacitor module.

[0023] According to one embodiment, the control of at least one mechanical brake of the bicycle causes the sending to the electronic unit of a signal triggering: - deactivation of engine assistance; - the application of engine braking.

[0024] According to one embodiment, the electronic control unit continuously monitors, via the supercapacitor module charge state sensor, that the charge state of the supercapacitor module always remains below 100%.

[0025] The invention is described below with reference to the attached drawing which represents:

[0026] [Fig-1] a simplified symbolic diagram of an electric assistance system for VAE according to the invention.

[0027] An EAB equipped with an electrical assistance system according to the invention comprises a frame, a front wheel, a rear wheel 1, two mechanical brakes and a crankset 2 connected to the rear wheel 1 for example by a chain 3. The electrical assistance system comprises a motor 4, a reversible inverter 5, a converter 8, a module 6 of supercapacitors 9, and an electronic unit 10 for controlling the converter 8. An electrical connection circuit 7 is arranged between the reversible inverter 5 and the converter 8. An electrical connection circuit 19 is arranged between the converter 8 and the module 6 of supercapacitors 9. A connection 18 for controlling the converter 8 is arranged between the electronic unit 10 and the converter 8.

[0028] The crankset 2 comprises at least one pedaling torque sensor 11, and at least one pedaling speed sensor 12. The electric motor 4 comprises at least one sensor 13 of the rotational speed of the motor 4, and at least one sensor 14 of the temperature of the motor 4. A sensor 15 of the state of charge of the module 6 of supercapacitors 9 is arranged on the circuit 19 connecting the converter 8 and the module 6 of supercapacitors 9. At least one sensor 16 of the temperature of the module 6 of supercapacitors 9 is arranged on the module 6. At least one sensor 17 detects the triggering of mechanical braking by the user of the bicycle. The sensors 11-17 are all connected to the electronic unit 10 for controlling the converter 8.

[0029] According to the invention, the electric motor 4 is a reduced motor without a freewheel, placed in the hub of the rear wheel 1. The rotor of the motor 4 is coupled to the rear wheel 1 via a speed reducer. By design, a reduced motor is a motor equipped with an internal freewheel and a planetary gear. It is lighter than a conventional motor. The internal freewheel allows for no rolling resistance.

[0030] According to the invention, the motor 4 used is a reduced motor without internal freewheel, which ensures that the motor 4, during braking phases, or when driving below the user's fatigue threshold, including downhill, operates in general. generator for recharging the energy reserve constituted by the module 6 of supercapacitors 9. The converter 8 ensures in particular the control of the variation of the value of the direct voltage between on the one hand the reversible inverter 5 and on the other hand the module 6 of supercapacitors 9. It also ensures the control of the power flows between on the one hand the module 6 of supercapacitors 9 and the motor 4 during the periods of electric assistance to the bicycle. Thus, the electric motor 4 is a reduced motor without freewheel, to ensure alternately operation as a propulsion motor of the VAE in assistance to the user, and operation as an electric current generator to ensure the recharging of the supercapacitors during the engine braking phases and during the movement phases when the effort is below the fatigue threshold.

[0031] The module 6 comprises several supercapacitors 9, used as electrical energy storage cells as soon as the bicycle is in motion or as a source of electrical power during acceleration phases. Unlike a battery, the supercapacitors are small components, easily mechanically integrated into the bicycle. In addition, they have a high level of safety which allows them to be integrated directly into the electronic control card. For example, the supercapacitors 9 are housed in extruded tubes serving as a frame for the luggage rack located above the rear wheel of the VAE. The energy storage reserve constituted by the module 6 of supercapacitors 9 has several advantages compared to a storage battery, and in particular, a lower mass, a shorter charging time, a longer service life and lower transfer losses.

[0032] According to the invention, a permanent check via the sensor 15 of the state of charge of the module 6 of supercapacitors 9 ensures verification that the state of charge of the module of supercapacitors always remains less than 100%.

[0033] The operation of the VAE according to the invention is analyzed as follows.

[0034] The user gets on the bike and drives it using the pedals 2. The sensors 11 of pedaling torque, and 12 of pedaling speed send their signals to the electronic unit 10 for controlling the converter 8. The sensors 13 for rotation speed of the motor 4, 14 for the temperature of the motor 4, 15 for the state of charge of the module 6 of supercapacitors 9, and 16 for the temperature of the module 6 of supercapacitors 9, send their signals to the electronic unit 10 for controlling the converter 8.

[0035] During the starting phase, the user presses the pedal and the pedaling torque sensor informs the electronic unit 10 of the need for electrical assistance, which controls the converter 8 so that the electrical energy available in the module 6 of supercapacitors 9 supplies the motor 4 via the reversible inverter 5. Thus, during the starting, acceleration or climbing phases, the electrical assistance is ensured, as in conventional VAE, by pre- lifting on the available energy reserve.

[0036] The electronic unit 10 for controlling the operation of the converter 8 receives the electronic signals from the aforementioned sensors and delivers control signals to the converter 8, to control, depending on the needs of the VAE, within the limits authorized by the temperatures of the different components, the direction of circulation of the current in the converter 8, either towards the motor 4 for the electric assistance, or towards the module 6 of supercapacitors 9 for the recharging of the energy reserve.

[0037] The electronic control unit 10 analyses on the one hand the rotation speed of the electric motor 4 and on the other hand the torque applied to the pedal assembly by the user. It deduces from this the possible need for assistance from the user depending on the state of charge of the supercapacitor module 6, or the opportunity to recharge the supercapacitors.

[0038] The use of a reduced motor without a freewheel makes it possible to know the rotation speed of the wheel via the speed of the motor. The electronic control unit 10 analyzes the gear ratio thanks to the rotation speed of the wheel and the pedaling speed, to better adjust the assistance. If the need is high but the user is not using the right gear ratio, this means that before using the assistance it would be better to change gear ratio. Thus, for the same level of effort, the assistance is less with a gear ratio that could be improved than when the gear ratio is already the best physically possible.

[0039] In a conventional VAE, the manual control of one of the brake levers ensures the cutting of the electrical power supply to the motor and therefore of the assistance provided by the motor. Each of the brake levers is equipped with a switch or a sensor to cut off the assistance of the motor in the event of a brake lever being controlled.

[0040] According to the invention, the control of a first brake lever ensures, by means of the sensor 17, the sending to the electronic unit 10 of a signal triggering the deactivation of the assistance function of the electric motor, but also the application of engine braking and the recovery of electrical energy, the motor operating as a generator. The control of the first brake lever ensures the reinforcement of engine braking and energy recovery. The subsequent or simultaneous control of the second brake lever ensures the significant increase in engine braking and energy recovery.

[0041] Mechanical braking is achieved by pressing the brake levers beyond the triggering of sensor 17 to cut off the motor assistance. Mechanical braking is used in rapid or emergency braking situations.

[0042] The use of a reduced motor without freewheel, or a direct drive motor, and a supercapacitor module accepting high power in a short time, makes it possible to use the motor as a generator to benefit significant engine braking and significant energy recovery, depending on the state of charge of the supercapacitor module 6 and within the limits permitted by the temperatures of the various components.

[0043] During the phases of movement without particular constraint, from the data received from the pedaling torque sensor 11, and from the pedaling speed sensor 12, the electronic unit 10 determines a limit torque value CL corresponding to the user's fatigue threshold.

[0044] Furthermore, it receives, in real time throughout the pedal revolutions, the information Cu of the torque useful for moving the bicycle. Comparison of the two values ​​shows that between Cu and CL, there is at least one value Cr of recharging torque greater than or equal to Cu, and the difference with Cu makes it possible to recharge the supercapacitors without significant fatigue of the user.

[0045] According to the invention, a manual control for a small movement of a mechanical brake lever ensures, by means of the sensor 17 and the electronic unit 10, the operation of the bicycle with the recharging torque Cr of the supercapacitors 9. With a torque Cr lower than the limit torque CL, and slightly higher than the useful displacement torque Cu of the VAE, a low power is recovered during the fairly long duration of the displacement, so as to ensure a significant recharging of the module 6 of the supercapacitors 9. Thus, the electronic unit 10 makes it possible to ensure management of the assistance provided by the user to the recharging of the energy reserve constituted by the supercapacitors.

[0046] Depending on the measured pedaling torque and the pedaling speed ensured by the pedaling cadence of the user, the electronic control unit 10 ensures the automatic control of the energy storage phases, and of assistance to the electric motor 4, independently of the user's practices to optimize the management of the electrical energy stored in the module 6 of supercapacitors 9.

[0047] In other words, whereas conventional VAEs only manage the supply of additional energy, the VAE according to the invention also manages the user's energy for recharging the additional energy reserve.

Claims

Claims

1. Electrically assisted bicycle, comprising: a rear wheel (1), a front wheel, a crankset (2) mechanically connected to the rear wheel (1), an electric assistance motor (4), supplied with electric current, characterized in that: - the electric motor (4) is a motor without a freewheel; - the electric current is supplied by a module (6) of supercapacitors (9), controlled by a converter (8); - at least one pedaling torque sensor (11) and at least one pedaling speed sensor (12) are arranged in connection with the crankset (2); - a rotational speed sensor (13) controls the rotational speed of the electric motor (4); - a voltage sensor (15) measures the state of charge of the module (6) of supercapacitors (9);and - an electronic control unit (10) ensures the operation of the converter (8) as a function of the pedaling torque, the pedaling speed, the rotation speed of the electric motor (4), and the state of charge of the module (6) of supercapacitors (9).;

2. Electrically assisted bicycle according to claim 1 characterized in that it further comprises two mechanical brakes, a means (17) ensuring the detection of mechanical braking, and in that the electronic control unit (10) also ensures the operation as a generator of the electric motor (4) for recharging the energy reserve constituted by the module (6) of supercapacitors (9) according to the state of charge of the module (6) of supercapacitors (9) as soon as mechanical braking is detected.

3. Electrically assisted bicycle according to claim 1 or 2, characterized in that the electric motor (4) is a reduced motor without freewheel.

4. Electrically assisted bicycle according to claim 1 or 2, characterized in that the electric motor (4) is a direct drive motor.

5. Electrically assisted bicycle according to one of claims 1 to 4, characterized in that the electric motor (4) is located in the hub of the rear wheel (1).

6. Electrically assisted bicycle according to one of claims 1 to 4, characterized in that the electric motor (4) is located in the hub of the front wheel.

7. Electrically assisted bicycle according to one of claims 1 and 3 to 6, ca- characterized in that the sensor (13) of the rotation speed of the electric motor (4) is located in the axis of the wheel carrying the electric motor.

8. Electrically assisted bicycle according to one of claims 1 and 3 to 6, characterized in that the sensor (13) of the rotation speed of the electric motor (4) is located on the spokes of one of the wheels.

9. Electrically assisted bicycle according to one of claims 1 and 3 to 8, characterized in that the pedaling torque sensor (11) is integrated in the motor (4).

10. Electrically assisted bicycle according to one of claims 1 and 3 to 9, characterized in that the pedaling speed sensor (12) is integrated in the motor (4).

11. Electrically assisted bicycle according to one of claims 2 to 6, characterized in that the means (17) for detecting mechanical braking consists of at least one sensor.

12. Electrically assisted bicycle according to one of claims 2 to 6, characterized in that the means (17) for detecting mechanical braking consists of at least one contactor.

13. Electrically assisted bicycle according to claim 1 or 2, characterized in that the mechanical connection between the crankset (2) and the rear wheel (1) is provided by chain (3), belt or cardan shaft.

14. Electrically assisted bicycle according to one of claims 1 to 13, characterized in that the electronic control unit (10) is connected to at least one sensor (16) of the temperature of the module (6) of supercapacitors (9).

15. Electrically assisted bicycle according to one of claims 1 to 14, characterized in that the electronic control unit (10) is connected to at least one sensor (14) of the temperature of the electric motor (4).

16. Electrically assisted bicycle according to one of claims 1 to 15, characterized in that a voltage sensor (15) measures the state of charge of each of the supercapacitors (9) of the module (6) of supercapacitors (9).

17. Electrically assisted bicycle according to one of claims 2 to 6 and 11 to 16, characterized in that the control of at least one mechanical brake of the bicycle causes the sending to the electronic unit (10) of a signal triggering: - the deactivation of the assistance of the motor (4), - the application of the motor braking.

18. Electrically assisted bicycle according to one of claims 1 to 17, ca- characterized in that the electronic control unit (10) continuously monitors, via the sensor (15) of the state of charge of the module (6) of supercapacitors (9), that the state of charge of the supercapacitor module always remains below 100%.

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