JPH07267175A - Bicycle with motor and control method for motive power thereof - Google Patents

Abstract

PURPOSE:To provide a bicycle with a motor and a control method for the motive power thereof wherein drive is practicable in a state that a wheel axle is stabilized in spite of the rapid fluctuation of a pedaling force. CONSTITUTION:A bicycle 1 with a motor wherein forces from a pedal and a motor 4 are joined together to transmit it to a rear wheel is provided with a torque sensor 33 to detect torque of a rear wheel, a number of revolutions sensor 38 to detect the number of revolutions of the rear wheel, and a controller 10 to control the motor 4 based on detecting torque of the torque sensor 33 and the number of revolutions detected by the number of revolutions sensor 38. Since feedback control is applied on the motor 4 based on detecting torque from the torque sensor 33 and the number of revolutions detected by the number of revolutions sensor 38, rapid control for the motor 4 according to an output for the rear wheel is practicable. Thereby, even when a rapid high force is temporarily exerted on the pedal, a wheel 16 is reliably and stably driven.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a motorized bicycle and a power control method thereof.

[0002]

2. Description of the Related Art An example of a conventional motorized bicycle and its power control method will be described with reference to FIG. In this motor-equipped bicycle 1, a force F _p from a pedal 2 and a force F _m from a motor 4 via a speed reducer 3 are combined by a combination mechanism 5, and this force F _t is transmitted to a transmission mechanism 6 such as a chain or a shaft. The torque is transmitted to the wheels 7 via the wheels. Further, between the pedal 2 and the resultant force mechanism 5, there are a torque detecting means 8 for detecting a pedaling force F _p applied to the pedal 2, and thus a torque T _p , and a rotation speed detecting means 9 for detecting a rotation speed S _p of the pedal 2. Is provided.

A controller 10 is connected to the torque detecting means 8, the rotation speed detecting means 9 and the motor 4. The controller 10 controls the torque T _p from each detecting means.
And the work amount W _p is calculated from the rotation speed S _p , and a force equivalent to this work amount W _p (the ratio of the force on the pedaling force side to the assist amount is set to 1: 1) is applied to the speed reducer 3. The motor 4 is controlled by outputting an assist signal to the motor 4 so that the motor 4 can be applied to the resultant force mechanism 5 (other examples of the motor-equipped bicycle 1 of the same type are disclosed in JP-A-4-24496 and JP-A-5-24496). -58379).

[0004]

By the way, in the above-mentioned prior art, the driving force F _t of the wheel shaft may change suddenly (disturbance) due to gear backlash or the like.
It may take time to converge the vibration change of the driving force F _t of the wheel shaft. This phenomenon will be described with reference to FIG.

In FIG. 11, the pedaling force F applied to the pedal 2
Normally, _p is the largest when pedal 2 is depressed,
It becomes smaller when the pedal 2 goes up, and can be represented by a substantially sine curve when the horizontal axis represents time. Similarly, the driving force F _m of the motor 4 and the driving force F _{t of the} seven shafts of the wheel at the normal time are
Can be represented by a substantially sine curve, where the horizontal axis represents time. Then, at time t ₁ , when the force f _p1 is added to the pedaling force F _p of the pedal 2 due to a disturbance as shown in part (a), the motor 4 drives the normal driving force F _p as shown in part (b). A force obtained by adding the same force f _m1 (f _m1 = f _p1 ) as this force f _p1 to _m is output. Therefore, the wheel 7, (C) 2 times the driving force of the depression force f _p1 during normal driving force F _t as shown in section f _t1 (f
_p1 = _fp1 + _fm1 = 2 × _fp1 ) is applied and a large force acts.

Due to the large force applied to the wheel 7,
Minute time from time t ₁ (control cycle of controller 10)
At the time t ₂ when Δt has elapsed, the driver applies a pedaling force smaller than the pedaling force F _p in the normal state by a force f _p2 to the pedal 2. In response to the depression force being reduced by the force f _p2, the driving force of the motor 4 is smaller than the driving force F _m in the normal state by the force f
_It becomes smaller by _m2 (f _m2 = f _p2 ). Therefore, the wheels 7
Force is the driving force than the driving force F _t in the normal f _t2 (f _t2 =
It becomes smaller by f _p2 + f _m2 = 2 × f _p2 ).

At a time t ₃ when a minute time Δt has elapsed from the time t ₂ , the driving force of the wheels 7 suddenly becomes small, so that the driver has a force f _p3 minutes as compared with the pedaling force F _p at the normal time. Depress pedal 2 with a small pedaling force. Therefore, a large driving force acts on the wheel shaft in the same manner as described above. Thereafter, in the same manner, the human power and the force are transmitted to the wheel shaft by the motor 4, so that the vibration change of the driving force is not easily converged.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a motorized bicycle capable of stably driving a wheel shaft regardless of a sudden change in pedaling force and a power control method thereof.

[0009]

The invention according to claim 1 is
In order to achieve the above object, in a motor-equipped bicycle that combines forces from a pedal and a motor to be transmitted to wheels, a torque detecting means for detecting a torque on a wheel side and a rotational speed detecting means for detecting a rotational speed of a wheel. And a control means for controlling the motor based on the detected torque of the torque detection means and the rotation speed detected by the rotation speed detection means.

According to a second aspect of the present invention, the output of the motor is controlled on the basis of a control signal from the control means provided on the motor-equipped bicycle, and the output of the motor is selectively applied to the generated output of the pedal to the wheels. In the method of transmitting the auxiliary power of a motor-equipped bicycle, the torque and the rotation number on the wheel side are detected to obtain a feedback control amount, and then the control signal is adjusted based on the feedback control amount.

[0011]

According to the first aspect of the invention, the motor is controlled based on the detected torque of the torque detecting means and the rotational speed detected by the rotational speed detecting means, so that the motor can be quickly controlled according to the output of the wheel. Becomes

According to the second aspect of the present invention, the torque and the rotation speed on the wheel side are detected to obtain the feedback control amount, and then the control signal to the motor is adjusted based on the feedback control amount. It is possible to quickly control the motor according to the above.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A motorized bicycle according to an embodiment of the present invention and a power control method thereof will be described below with reference to FIGS. In the figure, a drive gear 12 is connected to a crankshaft 11 of a pedal 2 of a motorized bicycle 1. Rear wheel 1
A free wheel 15 connected to the drive gear 12 via a chain 14 to receive a force is provided on the third side.

An auxiliary shaft 17 is arranged in parallel with the axle of the rear wheel 13 (hereinafter referred to as wheel shaft 16). Auxiliary shaft 1
7 is an input shaft 18 connected to the free wheel 15,
An output shaft 19 that transmits the force of the input shaft 18 to the wheel shaft 16 side
And a torsionally deformable torsion bar 20 interposed between the input shaft 18 and the output shaft 19, and the pedaling force of the pedal 2 is applied to the input shaft 18 via the chain 14.
This force is received by the output shaft 1 via the torsion bar 20.
It is supposed to be transmitted to 9.

A motor 4 connected to a battery (not shown) is arranged near the auxiliary shaft 17. A first gear 21 is attached to the output shaft 19 of the motor 4. The input shaft 18 has a second gear 22 that is screwed into the first gear 21.
Is attached, and the torque of the motor 4 is the first and the second.
It is adapted to be transmitted to the input shaft 18 via the gears 21 and 22. In this embodiment, the input shaft 18 combines the force from the pedal 2 and the force from the motor 4. The first and second gears 21 and 22 constitute the speed reducer 3.

A third gear 23 is attached to the output shaft 19. A fourth gear 24 screwed to the third gear 23 is attached to the wheel shaft 16, and the force transmitted to the output shaft 19 is transmitted to the wheel shaft 16 via the third and fourth gears 23 and 24. Is transmitted to the rear wheel 13 to rotate the rear wheel 13. The input shaft 18, the torsion bar 20, and the output shaft 1
A tubular slider 25 is fitted on the auxiliary shaft 17 so as to cover the shaft 9.

An elongated hole 27 for a pin into which the pin 26 is inserted is provided at a portion of the slider 25 on the output shaft 19 side.
Is formed so as to extend in the longitudinal direction. The base end of the pin 26 is fitted in a hole 28 formed in the output shaft 19. The slider 25 and the output shaft 19 rotate integrally with each other in the rotational direction of the output shaft 19 via the pin 26, while the pin 26 moves along the elongated hole 27 for the pin and is relatively displaced in the axial direction. I am supposed to get it.

A groove 29 is formed obliquely with respect to the auxiliary shaft 17 in a portion of the input shaft 18 facing the slider 25, and a ball 30 is movably arranged in the groove 29. A ball fixing hole 31 for fixing the ball 30 is formed in a portion of the slider 25 on the input shaft 18 side. By thus forming the ball fixing hole 31 and the groove 29, the input shaft 18 receives the force from the pedal 2 or the motor 4, and the input shaft 18 and thus the groove 29 rotate relative to the slider 25 in the arrow A direction. Groove 2
The ball 30 is pressed against the wall forming 9 and the ball 30 and thus the slider 25 move in the direction of arrow B with respect to the input shaft 18 (for example, move by the length α).

An annular groove 32 is formed on the outer peripheral portion of the slider 25 on the input shaft 18 side. This annular groove 32
A torque sensor 33 is provided so as to face the. The torque sensor 33 includes a sensing pin 34 whose distal end is fitted in the annular groove 32 and which is displaced according to the axial displacement of the slider 25, a pin support portion 35 which displaceably supports the sensing pin 34, and a sensing pin. The slide resistor 36 has a resistance value that changes in accordance with the amount of displacement of the slide resistor 34, and a torque calculator 37 that calculates the torque T _t based on the resistance value of the slide resistor 36.

In the vicinity of the wheel shaft 16, the rotational speed S of the rear wheel 13
A rotation speed sensor 38 for detecting _t is provided. A controller (control means) 10 is connected to the torque calculation unit 37 of the torque sensor 33, the rotation speed sensor 38, and the motor 4. The controller 10 uses the torque calculation unit 3
The work amount W _t (W _t = T _t × S _t ) is calculated based on the torque T _t from the No. 7 and the rotation number S _t from the rotation number sensor 38, and at the same time, 1 / of the work amount W _t of the rear wheel 13 is calculated. 2 (W _m =
A work amount W _m having a magnitude corresponding to (1/2) × W _t ) is input to the motor 4 to control the motor 4. By controlling in this way, the work amount of 1/2 of the work amount W _t of the rear wheel 13 is applied from the motor 4 to the wheel shaft 16.

Since the voltage V _m applied to the motor 4 is constant, the controller 10 controls the current I _m flowing through the motor 4 so that I _m = W _m / V _m . The control method of the motor 4 is not limited to this, and may be performed by duty control. That is, as shown in FIG. 9, the voltage may be applied to the motor 4 for the time t with respect to the cycle T. In this case, the voltage is applied so that W _m = (t / T) × I _m × V _m . Incidentally, 39 in the figure indicates a saddle.

In the motor-equipped bicycle 1 having the above-described structure, when the force from the pedal 2 or the motor 4 is applied to the input shaft 18, the torsion bar 20 is twisted and the force is transmitted to the output shaft 19. Further, as the torsion bar 20 is twisted, a displacement (rotational angle deviation) occurs between the input shaft 18 and the output shaft 19 according to the torque acting on the input shaft 18. Along with this, the slider 25 moves in the arrow B direction with respect to the input shaft 18. Then, the sensing pin 34 is displaced following the slider 25, the slide resistance 36 changes accordingly, and the torque calculator 37 calculates the torque T _t based on the resistance value of the slide resistance 36. The controller 10 calculates the work amount W _t based on the torque T _t from the torque calculator 37 and the rotation speed S _t from the rotation speed sensor 38.
Is calculated, and the motor 4 is controlled so that half of the work W _t is transmitted from the motor 4 to the rear wheel 13 side.

Here, as shown in FIG. 8A, when the force f _p1 is added to the normal pedaling force F _p of the pedal 2 at time t ₁ due to the disturbance, the force of the wheel 7 becomes large at this time. Motor 4 for a very short time (controller 1
Outputs drive force F _m of the normal in the control cycle) Delta] t before 0, the driving force F _m of the motor 4 is not affected by the disturbance. Then, the rear wheel 1 is passed through the pedal 2 and the input shaft 18.
Since the force transmitted to 3 is weakened by the transmission system, the fluctuation f _t1 of the driving force F _t of the rear wheel 13 is the force f applied to the pedaling force F _p.
It is smaller than _p1 .

At a time t ₂ when a minute time Δt has elapsed from the time t ₁ , 1/2 of the fluctuation f _t1 of the driving force F _t of the rear wheel 13
The driving force added to the driving force F _m in the normal state by the force f _m (f _m = f _t1 × (1/2) <f _p1 ) corresponding to On the other hand, at this time, the pedal 2 is applied with a force smaller by the pedaling force f _p2 than the pedaling force F _p in the normal state. Therefore, the fluctuation of the driving force F _t of the rear wheels 13 is f _t2 = f _m −f
_{This is p2} , and the amount of change is smaller than in the conventional technique of FIG.

As described above, the motor 4 is controlled on the basis of the detected torque T _t of the torque sensor 33 and the detected rotation speed S _t of the rotation speed sensor 38, so that the motor 4 can be quickly controlled according to the output of the wheel 7. Is possible. Therefore, even if a large force suddenly acts on the pedal 2, the wheel shaft 16 can be driven reliably and stably. In the above-described conventional technique, the motor 4 is feedforward-controlled based on the force applied to the pedal 2 and the number of revolutions thereof, so that when a large force is suddenly applied to the pedal 2, the driving force of the wheels 7 may not converge. According to the present embodiment, however, such problems can be improved and stable operation can be maintained.

In the above embodiment, the motorized bicycle 1 is a three-wheeled motorized bicycle, but the present invention is not limited to this and may be a two-wheeled motorized bicycle. .

[0027]

Since the invention according to claim 1 is a bicycle with a motor configured as described above, the motor is controlled based on the detected torque of the torque detecting means and the rotational speed detected by the rotational speed detecting means. As a result, quick motor control according to the output of the wheel becomes possible, so that even if a large force acts on the pedal 2, the driving force of the wheel shaft can be reliably stabilized.

Since the invention according to claim 2 is the power control method for the motor-equipped bicycle configured as described above, the feedback control amount is obtained by detecting the torque and rotation speed on the wheel side, and then the feedback control is performed. Since the control signal for the motor 4 is adjusted based on the control amount, quick motor control according to the output of the wheel becomes possible, and a stable driving force can be applied to the wheel shaft regardless of the pedaling force fluctuation. it can.

[Brief description of drawings]

FIG. 1 is a sectional view showing a main part of a motor-operated bicycle according to an embodiment of the present invention.

FIG. 2 is a power system diagram of the motor-equipped bicycle.

FIG. 3 is a side view showing the bicycle with the motor.

FIG. 4 is a plan view showing the motor-equipped bicycle.

FIG. 5 is a partial cross-sectional view showing a slider mounting portion of the motor-equipped bicycle.

FIG. 6 is a side view showing the slider mounting portion.

FIG. 7 is a diagram showing an operation of the slider mounting portion.

FIG. 8 is a diagram showing forces acting on respective parts of the motor-equipped bicycle.

FIG. 9 is a signal waveform diagram showing another example of the motor control method for the motor-equipped bicycle.

FIG. 10 is a power system diagram showing an example of a conventional motorized bicycle.

FIG. 11 is a diagram showing forces acting on respective parts of the motor-equipped bicycle.

[Explanation of symbols]

 1 Bicycle with motor 2 Pedal 4 Motor 13 Rear wheel 25 Slider 32 Annular groove 33 Torque sensor 34 Sensing pin 36 Slide resistance 37 Torque calculator 38 Rotation speed sensor

Claims (2)

[Claims] 1. In a motor-equipped bicycle that combines forces from pedals and a motor and transmits them to wheels, torque detecting means for detecting torque on the wheel side, rotational speed detecting means for detecting rotational speed of the wheels, and torque. A motorized bicycle, comprising: a control unit that controls the motor based on the detected torque of the detection unit and the rotation speed detected by the rotation speed detection unit. 2. A motorized bicycle in which the output of the motor is controlled on the basis of a control signal from a control means provided in the motorized bicycle, and the output of the motor is selectively applied to the generated output of the pedal and transmitted to the wheels. In the auxiliary power control method, the torque and the rotation speed on the wheel side are detected to obtain a feedback control amount, and then the control signal is adjusted based on the feedback control amount.