JP2008143330A - Driving force control device for electrically assisted bicycle and electrically assisted bicycle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a driving force control device for an electrically assisted bicycle and the electrically assisted bicycle capable of extending a cruising distance without changing practical magnitude and occasion of assist driving force to be applied. <P>SOLUTION: When an assist driving force control part 109 determines that the electrically assisted bicycle is travelling on a downslope based on an inclination angle α detected by an inclination angle detecting part 105, the assist driving force ta is lowered comparing with the assist driving force for travelling on a flat road. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a driving force control device for a battery-assisted bicycle and a battery-assisted bicycle that change an auxiliary driving force generated by an electric motor in accordance with an inclination angle of a traveling road surface.

  Conventionally, the electric motor torque (hereinafter appropriately abbreviated as “motor torque”) is controlled in accordance with the force with which the rider rides the crank pedal (hereinafter abbreviated as “human torque” as appropriate), and a predetermined auxiliary driving force is obtained. The generated battery-assisted bicycle is widely used.

Such a driving force control device for a battery-assisted bicycle detects human power torque and outputs a control signal for controlling motor torque in accordance with the detected human power torque. Furthermore, a method of detecting an inclination angle of a traveling road surface of a battery-assisted bicycle and increasing an auxiliary driving force on an uphill than a flat road is also known (for example, Patent Document 1).
Japanese Patent Laid-Open No. 11-34966 (page 4, FIG. 5)

  However, the conventional power assist bicycle driving force control apparatus described above has the following problems. That is, the battery-assisted bicycle is heavier than a general bicycle due to the mounting of an electric motor and a battery used to drive the electric motor. For this reason, when the auxiliary driving force cannot be obtained due to the consumption of the electric power stored in the battery, there is a problem that the rider has to pedal the crank pedal with a larger force than a general bicycle.

  Therefore, the present invention has been made in view of such a situation, and the driving force control of the battery-assisted bicycle that can further extend the cruising distance without changing the size of the practical auxiliary driving force or the opportunity of providing it. An object is to provide a device and a battery-assisted bicycle.

  In order to solve the above-described problems, the present invention has the following features. First, the first feature of the present invention is that a human-powered torque detecting unit (torque detecting unit) detects a human-powered torque generated when a rider runs a crank pedal (crank pedal 41) connected to a crankshaft (crankshaft 40). 107), an inclination angle detection unit (inclination angle detection unit 105) for detecting an inclination angle (inclination angle α) of the traveling road surface (road surface R), the human power torque detected by the human power torque detection unit, and the inclination An auxiliary driving force control unit (auxiliary driving force control unit 109) that controls an auxiliary driving force (auxiliary driving force ta) generated by the electric motor (electric motor 111) according to the inclination angle detected by the angle detection unit; A driving force control device (driving force control device 100) for a battery-assisted bicycle (power-assisted bicycle 10) including the auxiliary driving force control unit detected by the tilt angle detection unit. When it is determined that the battery-assisted bicycle is traveling downhill based on the tilt angle, the assist driving force is made lower than that when the battery-assisted bicycle is traveling on a flat road. And

  According to such a driving force control device for a battery-assisted bicycle, when it is determined that the battery-assisted bicycle is traveling downhill, the power assist bicycle has a lower assist driving force than when the battery-assisted bicycle is traveling on a flat road. Become. That is, when the battery-assisted bicycle is traveling downhill, the power consumption is suppressed by reducing the torque (motor torque) generated by the electric motor. In addition, since the auxiliary driving force is low when the vehicle is traveling on a power-assisted bicycle downhill, the rider does not feel uncomfortable due to a decrease in the auxiliary driving force. That is, according to such a driving force control device for a battery-assisted bicycle, the cruising distance of the battery-assisted bicycle can be further extended without changing the magnitude or opportunity of practical auxiliary driving force.

  A second feature of the present invention relates to the first feature of the present invention, and is a crankshaft rotational speed detector (crankshaft rotational speed detector 101) for detecting the rotational speed of the crankshaft (crankshaft rotational speed VR). The auxiliary driving force control unit further comprises the auxiliary drive based on the rotational speed detected by the crankshaft rotational speed detection unit when it is determined that the battery-assisted bicycle is traveling downhill. The gist is to decide whether or not to lower the force.

  A third feature of the present invention relates to the second feature of the present invention, and is a travel speed detector (travel speed detector 103) for detecting a travel speed (travel speed V) of the battery-assisted bicycle, and the inclination angle. And a storage unit (storage unit 115) for storing a control map in which at least the rotation speed, the traveling speed, and the auxiliary driving force are associated with each other, and the auxiliary driving force control unit is configured to lower the electric auxiliary bicycle. The gist is to control the auxiliary driving force based on the control map stored in the storage unit when it is determined that the vehicle is traveling on a hill.

  The fourth feature of the present invention is that wheels (front wheels 20, rear wheels 30) that roll on a road surface (road surface R), handles (handles 21) that operate the directions of the wheels, and crankshafts (crankshafts 40). A crank pedal (crank pedal 41) connected to the electric motor, an electric motor (electric motor 111) that generates auxiliary driving force, and a human-power torque detector (torque) that detects human-power torque generated by the rider riding the crank pedal. A detection unit 107), an inclination angle detection unit (inclination angle detection unit 105) for detecting an inclination angle of the traveling road surface (road surface R), the human power torque detected by the human power torque detection unit, and the inclination angle detection unit. A battery-assisted bicycle (power-assisted rotation) including an auxiliary drive force control unit (auxiliary drive force control unit 109) that controls the auxiliary drive force according to the inclination angle detected by the 10) When the auxiliary driving force control unit determines that the battery-assisted bicycle is traveling downhill based on the inclination angle detected by the inclination angle detection unit, the battery-assisted bicycle The gist is to make the auxiliary driving force lower than when traveling on a flat road.

  The fifth feature of the present invention is summarized in that it is a battery-assisted bicycle provided with the driving force control device for the battery-assisted bicycle according to the second or third feature of the present invention.

  According to the features of the present invention, it is possible to provide a driving force control device for an electrically assisted bicycle and an electrically assisted bicycle that can further extend the cruising distance without changing the magnitude and opportunity of practical auxiliary driving force.

  Next, an embodiment of a battery-assisted bicycle according to the present invention will be described with reference to the drawings. In the following description of the drawings, the same or similar parts are denoted by the same or similar reference numerals. However, it should be noted that the drawings are schematic and ratios of dimensions are different from actual ones.

  Accordingly, specific dimensions and the like should be determined in consideration of the following description. Moreover, it is a matter of course that portions having different dimensional relationships and ratios are included between the drawings.

(Structure of battery-assisted bicycle)
FIG. 1 is a right side view of a battery-assisted bicycle 10 according to the present embodiment. As shown in FIG. 1, the battery-assisted bicycle 10 is a two-wheeled vehicle including a front wheel 20 and a rear wheel 30 that roll on a road surface R. Further, the battery-assisted bicycle 10 includes a handle 21, a crankshaft 40, and a driving force control device 100.

  The handle 21 is gripped by the rider and used to operate the direction of the front wheel 20. A crank pedal 41 is connected to the crankshaft 40. The crankshaft 40 is rotated by the force (human power torque) that the rider rides on the crank pedal 41, and the driving force is transmitted to the rear wheel 30 via the chain 42.

  The driving force control device 100 controls the torque (motor torque) of the electric motor 111 according to the force (manpower torque) that the rider turns the crank pedal 41 to generate a predetermined auxiliary driving force ta. The driving force control device 100 and the electric motor 111 are connected to the battery 50 disposed above the front wheel 20.

(Functional block configuration of the driving force control device for the battery-assisted bicycle)
FIG. 2 is a functional block configuration diagram of the driving force control apparatus 100. As shown in FIG. 2, the driving force control device 100 includes a crankshaft rotation speed detection unit 101, a traveling speed detection unit 103, an inclination angle detection unit 105, a torque detection unit 107, an auxiliary driving force control unit 109, an electric motor 111, A transmission gear unit 113 and a storage unit 115 are provided.

  The crankshaft rotation speed detector 101 detects the crankshaft rotation speed VR of the crankshaft 40. Specifically, the crankshaft rotational speed detector 101 has a sensor that detects the crankshaft rotational speed VR, and outputs the crankshaft rotational speed VR detected by the sensor to the auxiliary driving force controller 109.

  The traveling speed detection unit 103 detects the traveling speed V of the battery-assisted bicycle 10. Specifically, the traveling speed detection unit 103 includes a sensor that detects the rotational speed of the rear wheel 30 (or the front wheel 20), and the rotational speed of the rear wheel 30 detected by the sensor is transmitted to the auxiliary driving force control unit 109. Output. The auxiliary driving force control unit 109 calculates the traveling speed V of the battery-assisted bicycle 10 based on the rotational speed of the rear wheel 30 output from the traveling speed detection unit 103.

  The inclination angle detection unit 105 detects an inclination angle α of the road surface R (traveling road surface) on which the battery-assisted bicycle 10 travels. Specifically, the tilt angle detection unit 105 includes a sensor that detects the tilt angle α, and outputs the tilt angle α detected by the sensor to the auxiliary driving force control unit 109.

  The torque detector 107 detects the driving force (driving torque) transmitted to the rear wheel 30. Specifically, the torque detection unit 107 detects the total torque of human power torque and motor torque. In the present embodiment, the torque detection unit 107 constitutes a human power torque detection unit.

  The auxiliary driving force control unit 109 controls the torque (motor torque) of the electric motor 111 according to the force (manpower torque) that the rider turns the crank pedal 41 to generate a predetermined auxiliary driving force ta. Specifically, the auxiliary driving force control unit 109 calculates human power torque based on the total torque detected by the torque detection unit 107, and outputs a control signal for controlling the motor torque according to the calculated human power torque. Output to.

  In particular, in the present embodiment, the auxiliary driving force control unit 109 controls the auxiliary driving force ta according to the human power torque and the inclination angle α detected by the inclination angle detection unit 105. Specifically, when the auxiliary driving force control unit 109 determines that the battery-assisted bicycle 10 is traveling on a downhill based on the inclination angle α detected by the inclination angle detection unit 105, the battery-assisted bicycle 10 is The auxiliary driving force ta is made lower than when traveling on a flat road. That is, the auxiliary driving force control unit 109 reduces the torque (motor torque) generated by the electric motor 111 and suppresses power consumption when the battery-assisted bicycle 10 is traveling downhill.

  Further, when the auxiliary driving force control unit 109 determines that the battery-assisted bicycle 10 is traveling on a downhill, the auxiliary driving force control unit 109 is based on the crankshaft rotation speed VR detected by the crankshaft rotation speed detection unit 101. It can be determined whether or not ta is lowered. In other words, the auxiliary driving force control unit 109, even when the battery-assisted bicycle 10 is traveling downhill, if the rider is scrambling the crank pedal 41 at a predetermined speed or higher, the auxiliary driving force ta similar to that on a flat road. Is generated.

  In the present embodiment, the auxiliary driving force control unit 109 controls the auxiliary driving force ta based on the control map stored in the storage unit 115 when it is determined that the battery-assisted bicycle 10 is traveling downhill. To do.

Here, FIG. 4 shows an example of a control map stored in the storage unit 115. As shown in FIG. 4, in the control map, the inclination angle alpha (downlink), the crankshaft rotation speed V _R, the traveling speed V and the auxiliary driving force t _a is associated.

  In the example shown in FIG. 4, a control map M11 to M13 used when traveling on a flat road and a control map M21 used when traveling on a downhill are set. In the control map M21, when the value of the inclination angle α indicates a downhill (a negative value greater than or equal to a predetermined magnitude), the auxiliary driving force ta is reduced compared to the control maps M11 to M13. . The control maps M11 to M13 may be selected by the user of the battery-assisted bicycle 10.

Auxiliary driving force control unit 109, based on the crankshaft rotation speed V _R detected by the crankshaft rotation speed detection unit 101 determines whether or not using the control map M21. Specifically, the auxiliary driving force control unit 109, when the variation of the crankshaft rotation speed V _R is equal to or greater than a predetermined size, using the control map M21.

  In addition to the inclination angle α, the crankshaft rotation speed VR, the traveling speed V, and the auxiliary driving force ta, the control map may be associated with human torque detected by the torque detection unit 107.

  The electric motor 111 generates the auxiliary driving force ta based on the control signal output from the auxiliary driving force control unit 109. The electric motor 111 is engaged with the chain 42, and the auxiliary driving force ta is transmitted to the rear wheel 30 via the chain 42.

  The transmission gear unit 113 changes the rotation speed of the electric motor 111. Specifically, the transmission gear unit 113 decelerates the rotation speed of the electric motor 111. The transmission gear unit 113 may be composed of a plurality of gears having different reduction ratios.

  The storage unit 115 stores the control map shown in FIG. Specifically, the storage unit 115 is configured by a nonvolatile RAM.

(Operation of the driving force control device for a battery-assisted bicycle)
Next, the operation of the driving force control apparatus 100 will be described. Specifically, an operation for lowering the auxiliary driving force ta when it is determined that the battery-assisted bicycle 10 is traveling on a downhill compared to when the battery-assisted bicycle 10 is traveling on a flat road will be described.

  FIG. 3 is an operation flowchart of the driving force control apparatus 100. As shown in FIG. 3, in step S10, the driving force control device 100 detects human power torque. Specifically, the driving force control apparatus 100 calculates the human power torque based on the total torque of the human power torque and the motor torque detected by the torque detection unit 107.

  In step S20, the driving force control apparatus 100 detects the inclination angle α of the road surface R on which the battery-assisted bicycle 10 travels. In step S30, the driving force control apparatus 100 detects the crankshaft rotation speed VR. In step S40, the driving force control apparatus 100 detects the traveling speed V. Note that the processing in steps S10 to S40 may be executed simultaneously instead of in time series.

  In step S50, the driving force control apparatus 100 determines whether or not the battery-assisted bicycle 10 is traveling downhill based on the detected inclination angle α. In addition to the inclination angle α, the driving force control apparatus 100 may determine that the vehicle is traveling on a downhill when the traveling speed V is equal to or greater than a predetermined value.

When the battery-assisted bicycle 10 is traveling downhill (YES in step S50), in step S60, the driving force control device 100 refers to the control map. Specifically, the driving force control device 100, based on the detected inclination angle α and the crankshaft rotation speed V _R, determining whether to use the control map used at the time of traveling downhill M21 (see FIG. 4) To do. Here, it is assumed that the control map M21 is selected.

  In step S70, the driving force control apparatus 100 determines whether or not the auxiliary driving force ta needs to be reduced based on the referenced control map M21.

  When it is necessary to reduce the auxiliary driving force ta (YES in step S70), in step S80, the driving force control device 100 decreases the auxiliary driving force ta. Specifically, the driving force control device 100 makes the torque (motor torque) of the electric motor 111 lower than when the battery-assisted bicycle 10 is traveling on a flat road.

(Action / Effect)
According to the driving force control apparatus 100, when it is determined that the battery-assisted bicycle 10 is traveling on a downhill, the assist driving force ta is lower than that when the battery-assisted bicycle 10 is traveling on a flat road. That is, when the battery-assisted bicycle 10 is traveling on a downhill, power consumption is suppressed by reducing the torque (motor torque) generated by the electric motor 111. Note that the auxiliary driving force ta is low when the battery-assisted bicycle 10 is traveling downhill, so that the rider does not feel uncomfortable due to the decrease in the auxiliary driving force ta. That is, according to the driving force control apparatus 100, the cruising distance of the battery-assisted bicycle 10 can be further extended without changing the magnitude or opportunity of the practical auxiliary driving force ta.

  Furthermore, since power consumption by the electric motor 111 is suppressed, a smaller and lighter battery 50 can be used. Further, since power consumption by the electric motor 111 is suppressed, it is not necessary for the rider to provide a mode switching unit that switches between the normal mode (power mode) and the power saving mode according to the exhausted state of the battery 50.

  In the present embodiment, the driving force control apparatus 100 can determine whether or not to reduce the auxiliary driving force ta based on the crankshaft rotational speed VR. Specifically, even when the battery-assisted bicycle 10 is traveling downhill, if the rider is stroking the crank pedal 41 at a predetermined speed or higher, the same auxiliary driving force ta as that on a flat road can be generated. it can.

  That is, even when the battery-assisted bicycle 10 is traveling downhill, if the rider needs the auxiliary driving force ta, the auxiliary driving force ta similar to that on a flat road can be generated.

  In the present embodiment, the driving force control device 100 controls the auxiliary driving force ta based on the control map stored in the storage unit 115. For this reason, the control pattern of the auxiliary driving force ta can be easily changed by rewriting the contents of the control map stored in the storage unit 115.

(Other embodiments)
Although the contents of the present invention have been disclosed through the embodiments of the present invention as described above, it should not be understood that the descriptions and drawings constituting a part of this disclosure limit the present invention. From this disclosure, various alternative embodiments, examples and operational techniques will be apparent to those skilled in the art.

  For example, in the embodiment described above, the storage unit 115 control map configured by a nonvolatile RAM is stored, but the storage unit 115 may be configured by a ROM. In the above-described embodiment, the two-wheeled vehicle including the front wheel 20 and the rear wheel 30 has been described as an example. However, the present invention is naturally applicable to a power-assisted bicycle other than the two-wheeled vehicle, for example, a power-assisted bicycle including three wheels. it can.

  As described above, the present invention naturally includes various embodiments that are not described herein. Therefore, the technical scope of the present invention is defined only by the invention specifying matters according to the scope of claims reasonable from the above description.

1 is a right side view of a battery-assisted bicycle according to an embodiment of the present invention. It is a functional block block diagram of the driving force control apparatus which concerns on embodiment of this invention. It is an operation | movement flowchart of the driving force control apparatus which concerns on embodiment of this invention. It is a figure which shows an example of the control map used in the driving force control apparatus which concerns on embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Electric assistance bicycle, 20 ... Front wheel, 21 ... Handle, 30 ... Rear wheel, 40 ... Crankshaft, 41 ... Crank pedal, 42 ... Chain, 50 ... Battery, 100 ... Driving force control apparatus, 101 ... Crankshaft rotational speed Detecting unit 103 ... Traveling speed detecting unit 105 ... Inclination angle detecting unit 107 ... Torque detecting unit 109 ... Auxiliary driving force control unit 111 ... Electric motor 113 ... Transmission gear unit 115 ... Storage unit M11-M13 , M21 ... control map, R ... road surface

Claims (5)

A human torque detector for detecting a human torque generated by a rider stroking a crank pedal connected to the crankshaft;
An inclination angle detector for detecting the inclination angle of the road surface;
And an auxiliary driving force control unit that controls an auxiliary driving force generated by an electric motor in accordance with the human torque detected by the human torque detection unit and the inclination angle detected by the inclination angle detection unit. A driving force control device for an auxiliary bicycle,
When the auxiliary driving force control unit determines that the battery-assisted bicycle is traveling downhill based on the inclination angle detected by the inclination angle detection unit, the battery-assisted bicycle travels on a flat road. A driving force control device for a battery-assisted bicycle that makes the auxiliary driving force lower than that of the case. A crankshaft rotation speed detector for detecting the rotation speed of the crankshaft;
The auxiliary driving force control unit reduces the auxiliary driving force based on the rotation speed detected by the crankshaft rotation speed detection unit when it is determined that the battery-assisted bicycle is traveling on a downhill. The driving force control device for a battery-assisted bicycle according to claim 1, which determines whether or not. A traveling speed detector for detecting the traveling speed of the battery-assisted bicycle;
A storage unit that stores a control map in which at least the inclination angle, the rotation speed, the traveling speed, and the auxiliary driving force are associated;
The auxiliary driving force control unit controls the auxiliary driving force based on the control map stored in the storage unit when it is determined that the battery-assisted bicycle is traveling on a downhill. Drive assist control device for electric assist bicycles. Wheels rolling on the road surface,
A handle for operating the direction of the wheel;
A crank pedal coupled to the crankshaft;
An electric motor that generates auxiliary driving force;
A human-power torque detecting unit for detecting a human-power torque generated by a rider riding the crank pedal;
An inclination angle detector for detecting the inclination angle of the road surface;
An electric auxiliary bicycle comprising: an auxiliary driving force control unit that controls the auxiliary driving force according to the human power torque detected by the human power torque detection unit and the inclination angle detected by the inclination angle detection unit. And
When the auxiliary driving force control unit determines that the battery-assisted bicycle is traveling downhill based on the inclination angle detected by the inclination angle detection unit, the battery-assisted bicycle travels on a flat road. A battery-assisted bicycle that reduces the auxiliary driving force compared to the case where the vehicle is operated.   An electrically assisted bicycle comprising the drive force control device for an electrically assisted bicycle according to claim 2.

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