JP5211181B2 - Electric assist bicycle - Google Patents

Description

  The present invention relates to a battery-assisted bicycle having a human power driving system using human power driving force and an electric driving system for driving an electric motor with a driving force corresponding to the human power torque of the human power driving system.

Conventionally, as this type of battery-assisted bicycle, for example, one that detects that a brake is applied on a downhill and generates a braking force on the motor has been proposed. (Patent Document 1)
In the configuration of Patent Document 1, the motor generates the braking force when it is detected that the brake is applied. Until the brake is applied, the motor cannot generate the braking force, It could not be regenerated.

Therefore, it has been proposed to detect the vehicle speed and the pedaling force, and when the pedal is light for the vehicle speed, determine that the vehicle is traveling downhill and charge the battery by controlling the motor to a regenerative state. (Patent Document 2)
Japanese Patent Laid-Open No. 4-100790 Japanese Patent Laid-Open No. 9-267790

  In Patent Document 2, the pedaling force required to travel on a flat road is determined in advance corresponding to the vehicle speed and stored as a regeneration determination value. When the actual pedaling force at a certain vehicle speed is smaller than the regeneration determination value, the motor is operated. It is configured to switch to the regenerative state.

  However, the pedaling force required to travel on a flat road must be obtained in advance corresponding to the vehicle speed and stored as a regeneration determination value, which causes a problem of complicated control. Furthermore, when the driver's weight is light, even when driving on a flat road, it is assumed that the actual pedaling force at a certain speed becomes smaller than the regeneration determination value and the motor is switched to the regeneration state. In addition, when traveling with heavy loads, the actual pedaling force at a certain speed does not become smaller than the regeneration judgment value even when traveling downhill, and the state should be switched to the regeneration state. Nevertheless, there is a problem that switching to the regenerative state is uncertain, for example, it is assumed that the regenerative state is not switched.

  In view of such a problem, an object of the present invention is to provide a battery-assisted bicycle that can be reliably switched to a regenerative state with a simple configuration.

The present invention includes a human power driving system using a human power driving force, and an electric driving system that drives an electric motor with a driving force corresponding to a detection value of a torque detection unit that detects a human power torque of the human power driving system. A control means for performing regenerative charging in the electric drive system when the number of rotations of the crank is equal to or less than a predetermined value, and a speed detecting unit for detecting the running speed, the control means having a running speed in the regenerative charging state if reduced, characterized in that to reduce the regenerative charging amount.

  It is preferable that the crank rotation speed is equal to or less than a predetermined value when the crank rotation speed is substantially absent.

  It is preferable that the predetermined value of the rotation speed of the crank is set to a rotation speed lower than the rotation speed of the crank when traveling on a flat road at the traveling speed detected by the speed detection unit.

  The control means preferably performs regenerative charging when the vehicle speed is equal to or higher than a certain speed.

According to the present invention, the downhill running state is determined based on the number of rotations of the crank, so that the regenerative charging is performed by more accurately determining the downhill running state regardless of the weight of the driver, the load, etc. Can charge the battery and maintain comfortable running. In addition, if the traveling speed is reduced due to regenerative charging, the regenerative charging amount can be reduced and the braking amount can be reduced to obtain a comfortable traveling property.

It is a block circuit diagram showing one embodiment of the present invention. It is the same flowchart. It is a side view of the battery-assisted bicycle. It is sectional drawing of the travel drive device. It is sectional drawing which shows the cam engagement part of the same stator and movable ring.

  An embodiment of the present invention will be described in detail below with reference to FIGS.

  First, the overall configuration of the battery-assisted bicycle will be described with reference to FIG.

  Reference numeral 1 denotes a main frame, which is connected to a front tube 2 provided at the front and a seat tube 4 provided below from the saddle 3, and a pedal 5 is connected to a connecting portion where the main frame 1 and the seat tube 4 are connected. An attached crank 6 and a travel drive device 7 rotated by the crank 6 are attached.

  Reference numeral 8 denotes a handle provided at the upper end of the front pipe 2, and reference numeral 9 denotes a front wheel provided at the lower end of the front pipe 2, which has a hub 10 incorporating a motor (not shown) so that the front wheel 9 is driven to rotate by the motor. It constitutes an electric drive mechanism.

  Reference numeral 11 denotes a rear wheel, which is provided with a sprocket (not shown) in which a chain 12 is installed between the travel drive device 7 and the human power to step on the pedal 5 from the travel drive device 7 via the chain 12 to the sprocket. A human-powered drive mechanism that transmits and rotates the rear wheel 11 is configured.

  A battery 13 is detachably disposed between the seat tube 4 and the rear wheel 11, and a control box 14 is provided at a connecting portion between the main frame 1 and the seat tube 4 and has a built-in control circuit. The motor is driven and controlled by the electric power supplied from the battery 13 based on the output of the control circuit.

  In the following description, the “forward rotation direction” is the rotation direction when the pedal 5 is depressed to advance the battery-assisted bicycle, and the “reverse rotation direction” is the rotation opposite to the “forward rotation direction”. Direction.

  FIG. 4 shows a section of the traveling drive device 7 configured on the crankshaft 15 of the crank 6 that rotates when the pedal 5 is depressed. The travel drive device 7 is urged in the reverse rotation direction by a rotating body 16 and a compression coil spring 17 with respect to the rotating body 16, and rotates by the rotation of the rotating body 16 to rotate the rear wheel 11 via the chain 12. The sprocket 18 is constituted by a torque detecting means 19 for detecting rotational torque by a phase shift between the rotating body 16 and the sprocket 18, and a cover body 20 disposed so as to be rotatable integrally with the rotating body 16 with the sprocket 18 interposed therebetween. Is done.

  The rotating body 16 is formed in an annular shape, and an inner blade 21 is formed in the center hole. A gear 22 attached to an end of the crank 6 on the crankshaft 15 side meshes with the inner blade 21, and the crankshaft 15 and the rotating body 16 rotate integrally.

  The sprocket 18 is fixed by screws to a mounting member 24 that is rotatably supported by a bearing 23 with respect to the crankshaft 15, and a sprocket portion projects from the rotating body 16 to the outer peripheral side.

  The torque detection means 19 is fitted on the outer side of the ring-shaped stator 25 fixed to the mounting member 24 and the stator 25, and the axial direction of the crankshaft 15 is determined by the phase shift between the rotating body 16 and the sprocket 18. And a sensor 27 that detects the amount of axial movement of the movable ring 26 and sends a signal to the control circuit.

  The movable ring 26 is made of metal, specifically, aluminum or aluminum alloy. The movable ring 26 is biased toward the cover body 20 by a spring 28. As shown in FIG. 5, the movable ring 26 is formed with a raised portion 29, and the raised portion 29 is formed with a cam surface 30. The stator 25 is formed with a protrusion 31 that is in sliding contact with the cam surface 30 of the movable ring 26, and the raised portion 29 and the protrusion 31 constitute a cam portion. As will be described later, when a phase shift occurs between the rotating body 16 and the sprocket 18, the movable ring 26 rotates in the axial direction of the crankshaft 15 while rotating with the cam surface 30 slidingly contacting the protrusion 31 of the stator 25. Moving.

  The sensor 27 includes a winding coil (not shown) that surrounds the movable ring 26 within the range of movement of the movable ring 26 in the axial direction, and detects a change in inductance of the winding coil due to movement of the movable ring 26 in the axial direction. It is. In the sensor 27, as the amount of penetration of the movable ring 26 into the winding coil increases, the inductance of the winding coil increases. The control circuit detects this change in inductance and controls the drive of the motor based on the result.

  Next, the control circuit will be described based on the block diagram shown in FIG.

  Reference numeral 32 denotes a motor built in the hub 10 of the front wheel 9, which rotates the front wheel 9 by the electric power supplied from the battery 13 via the charge / discharge circuit 33 or uses the rotation of the front wheel 9 to generate electric power. Then, the battery 13 is charged through the charge / discharge circuit 33. Hereinafter, a state in which the front wheel 9 is rotated by the electric power supplied from the battery 13 is referred to as a “non-regenerative state”, and a state in which the battery 13 is charged by generating power by the rotation of the front wheel 9 is referred to as a “regenerative state”.

  Reference numeral 34 denotes a power switch provided in an operation unit attached in the vicinity of the handle 8, and reference numeral 35 denotes a mode setting switch provided in the operation unit, which selects either “standard” or “auto-eco” operation mode. ing. In addition to the power switch 34 and the mode setting switch 35, the operation unit includes a light lighting switch 36 for controlling lighting of a light serving as a headlight, a battery remaining amount display unit 37 for displaying the remaining amount of the battery 13, and the mode. A mode display unit 38 for displaying the operation mode selected by the setting switch 35 is provided.

  A brake detection unit 39 detects that the bicycle has been braked. When the brake is applied, the motor 32 is set to the “regenerative state” and the battery 13 is charged. Reference numeral 40 denotes a speed detection unit that detects the traveling speed of the bicycle based on the rotational speed of the motor 32. A torque detection unit 41 includes the sensor 27 and detects a change in inductance of the winding coil to detect a pedaling force applied to the pedal 5. Reference numeral 42 denotes a crank speed detection unit which detects the number of rotations of the crank 6 from the output waveform of the sensor 27.

  43 is a control device for inputting signals from the power switch 34, the mode setting switch 35, the light lighting switch 36, the brake detecting unit 39, the speed detecting unit 40, the torque detecting unit 41 and the crank speed detecting unit 42, and charging / discharging. The circuit 33, the light on / off, the battery remaining amount display unit 37 and the mode display unit 38 are controlled.

  Thus, when the driver depresses the pedal 5 to start traveling, the rotating body 16 linked to the pedal 5 via the crank 6 tries to rotate, but the chain 12 is erected and linked to the rear wheel 11. A large resistance acts on the sprocket 18 to be applied. For this reason, the rotating body 16 starts rotating first, the compression coil spring 17 is compressed between the rotating body 16 and the sprocket 18, and a phase difference occurs between the rotating body 16 and the sprocket 18.

  When the phase of the rotating body 16 advances from the sprocket 18, the movable ring 26 that can rotate integrally with the rotating body 16 and move in the axial direction of the crankshaft 15 slidably contacts the cam surface 30 with the protrusion 31 of the stator 25. Then, the sensor 27 moves in the direction of entering the winding coil of the sensor 27. The inductance of the winding coil of the sensor 27 increases due to the penetration of the movable ring 26, and the torque detector 41 detects a change in the inductance of the winding coil, and the control device 43 controls the driving of the motor 32 based on the result. The bicycle is run by applying the auxiliary power of the motor 32 to the pedaling force by human power.

  Next, the operation of the “auto eco” mode will be described based on the flowchart shown in FIG. 2. It is determined whether or not the “auto eco” mode is selected (step 1), and if the “auto eco” mode is not selected, Regenerative charging is not performed (step 2). If the “auto eco” mode is selected, it is determined whether the crank 6 rotates at a predetermined speed or less and the bicycle is traveling at a constant speed or more (step 3).

  In the present embodiment, the constant speed is a speed at which a sufficient amount of charge can be obtained by regeneration, specifically, 7 km / h, and a predetermined value of the number of rotations of the crank 6 is set at a traveling speed on a flat road. The rotational speed is set somewhat lower than the rotational speed of the crank 6 at the time. When the rotational speed of the crank 6 is rotating at a lower rotational speed than the rotational speed of the crank 6 when traveling on a flat road at the current traveling speed, the traveling speed is higher than when the pedal 5 is depressed. It is determined that the vehicle is in a state where the vehicle is traveling, that is, a state where the vehicle is traveling on a downhill, or the state where the vehicle is traveling or the brakes are applied. Accordingly, in this state, regenerative charging is performed as described in step 4 and subsequent steps. Since the downhill running state is determined based on the rotation speed of the crank 6, it is possible to determine the downhill running state more accurately as compared with the conventional case regardless of the weight of the driver and the load.

  In step 3, when the traveling speed of the bicycle is equal to or lower than a predetermined speed, or when the rotational speed of the crank 6 is equal to or higher than the predetermined rotational speed, the process proceeds to step 2 and regenerative charging is not performed. In step 3, when the traveling speed of the bicycle is equal to or higher than a predetermined speed and the rotational speed of the crank 6 is equal to or lower than the predetermined rotational speed, it is determined whether regenerative charging is being performed (step 4).

  In step 4, if regenerative charging is not performed, the process proceeds to step 5 where regenerative charging is performed. In step 4, if it is in the state which is performing regenerative charge, it will transfer to step 6 and it will be judged whether it is decelerating. In step 6, if not decelerating, the process proceeds to step 7 to increase the regenerative charge amount. By increasing the regenerative charge amount, the travel distance can be increased, and by increasing the braking amount, an increase in speed on the downhill can be suppressed to obtain safety and comfortable travelability.

  In step 6, if the vehicle is decelerating, the process proceeds to step 8 and it is determined whether or not the charge amount is the minimum value. In step 8, if the charge amount is the minimum value, the process proceeds to step 2, and the regenerative charge is stopped to suppress further deceleration. If the charge amount is not the minimum value, the process proceeds to step 9, and the regenerative charge amount is set. Decrease. By determining that the vehicle is decelerating due to braking by regenerative charging and reducing the amount of braking, comfortable running performance can be obtained. In addition, when the brake is applied, priority is given to regenerative charging by brake operation, and the regenerative charge amount is not stopped based on the flowchart shown in FIG.

  In this embodiment, it is determined in step 3 whether or not the traveling speed is a constant speed, but it may be determined whether or not the traveling speed is accelerating.

  Further, in step 3, the predetermined value of the rotation speed of the crank 6 is set to a rotation speed lower than the rotation speed of the crank 6 when traveling on a flat road at the traveling speed detected by the speed detection unit. A close value may be set. If there is virtually no rotation of the crank 6, this means that the brake is applied, the vehicle is traveling downhill, or the speed is higher than necessary. By detecting the above, the control can be further simplified if it is configured to switch to regenerative charging regardless of the traveling speed.

13 Battery 32 Motor 40 Speed detection unit 42 Crank speed detection unit 43 Control device

Claims (4)

A human power drive system using a human power drive force; and an electric drive system that drives an electric motor with a drive force corresponding to a detection value of a torque detection unit that detects a human power torque of the human power drive system, and rotation of a crank of the human power drive system when the number is less than a predetermined value, and a control means for performing the regenerative charging by the electric drive system, and a speed detector for detecting a running speed, wherein, in the regenerative charging state, if reduced traveling speed A battery-assisted bicycle that reduces the amount of regenerative charge.   2. The battery-assisted bicycle according to claim 1, wherein the crank rotational speed is equal to or less than a predetermined value when the crank rotational speed is substantially absent.   2. The electric auxiliary according to claim 1, wherein the predetermined value of the rotation speed of the crank is set to a rotation speed lower than the rotation speed of the crank when traveling on a flat road at the travel speed detected by the speed detection unit. bicycle.   The battery-assisted bicycle according to any one of claims 1 to 3, wherein the control means performs regenerative charging when the vehicle speed is equal to or higher than a certain speed.

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