JPH0899683A - Auxiliary power control method for power bicycle and device therefor - Google Patents

Abstract

PURPOSE: To provide a method and a device for detecting depressing force at the time of pedaling by a mechanism completely different from the conventional one in a power bicycle mounted with a motor as an auxiliary power mechanism. CONSTITUTION: The workload of a bicycle is computed from the relation between bicycle speed and acceleration detected by an acceleration sensor 1 that can detect both acceleration and road surface inclination, or between the bicycle speed and the road surface inclination, and the output of a motor 4 is controlled according to the computed result. With the acceleration sensor 1 fitted to the optional position of the bicycle, depressing force detecting mechanism can be separated from driving force transmission mechanism.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an auxiliary power control method and apparatus for a power bicycle, which is applied to a power bicycle equipped with a motor that rotates with battery power as auxiliary power.

[0002]

2. Description of the Related Art In a bicycle, a person riding on the bicycle depresses a pedal with his / her foot to rotate a sprocket on a driving side, and the rotational force is transmitted to a sprocket on a driven side mounted on a rear wheel by a chain to run. One of the characteristics of the bicycle is that when the occupant depresses the pedal with normal force, the occupant can move at a speed faster than that of the pedestrian. Therefore, the number of teeth on the driving side sprocket is set sufficiently larger than the number of teeth on the driven side sprocket.

When the number of teeth of the sprocket is set in this way, the sprocket can travel comfortably on a flat paved road and the like, and does not give the passengers a great feeling of fatigue, but lacks strength when approaching an uphill road. As a result, the speed slows down, and if you try to increase it, you will need a large amount of force and you will feel much tired.

Therefore, a power bicycle has been devised and put into practical use, in which a motor that rotates with the power of a battery is mounted on a bicycle as an auxiliary power source and the motor is rotated as needed to assist the rotation of the rear wheels. In this case, it is preferable for the feeling that the rotational force generated by the motor is set to be equal to or slightly smaller than the pedaling force of the pedal. As a structure for detecting the pedaling force of the pedal, it may be considered that the pedaling force is attached to a mechanical portion for combining the pedaling force with the auxiliary power of the motor, a crankshaft portion of the pedal, or a chain portion.

As a prior art of a power bicycle, there is Japanese Patent Laid-Open No.
There is one disclosed in Japanese Patent Laid-Open No. 100790. In this publication, as shown in FIGS. 7A and 7B, elastic rods are attached to the resultant mechanism parts on the pedal side and the motor side, and the pedaling force is detected by the amount of twist of the rods.

Another example of the prior art is Japanese Patent Laid-Open No. 4-2.
No. 44496. In this publication, the pedaling force of the pedal is detected from the tension of the chain when the occupant travels by stepping on the pedal.

Still another example of the prior art is disclosed in Japanese Patent Application Laid-Open No. 5-58379. In this publication, as shown in FIG. 3 of the drawings, the pedal force is linked to the carrier of the planetary gear and the motor auxiliary power is transmitted to the ring gear to detect the pedaling force from the reaction force generated in the sun gear. It is something that is done.

[0008]

However, in any of the above methods, since a complicated pedal force detection mechanism is used on the drive force transmission mechanism, the pedal force may not be transmitted. When the pedaling force transmission mechanism fails, auxiliary power for the motor is not generated, so that there is no means for moving the bicycle except pushing the bicycle that has become heavy due to the motor, battery, etc. being mounted.

The present invention has been made in view of this point, and by detecting the pedaling force at the time of stepping on the pedal by a completely different mechanism, a power bicycle which does not have the problems of the above cited examples. The present invention seeks to provide an auxiliary power control method and apparatus.

[0010]

According to a first aspect of the present invention, the work of a bicycle is calculated from the acceleration detected by an acceleration sensor capable of detecting both the acceleration and the inclination angle of the road surface and the speed of the bicycle. An auxiliary power control method for a power bicycle, characterized in that output control of a motor is performed according to the calculation result.

According to a second aspect of the present invention, the work of the bicycle is calculated from the inclination angle of the road surface detected by an acceleration sensor capable of detecting both the acceleration and the inclination angle of the road surface and the bicycle speed, and the calculation result is obtained. A method for assisting power control of a power-assisted bicycle, comprising:

According to a third aspect of the present invention, an acceleration sensor is formed by a plate rotatably supported at an upper end thereof, the output side of the acceleration sensor is connected to a work amount calculation circuit, and An auxiliary power control device for a power bicycle, wherein an acceleration sensor is attached to a bicycle independently of a pedaling force transmission mechanism of a pedal.

[0013]

According to the first aspect of the invention, the amount of work currently required in relation to the acceleration can be known from the output value of the acceleration sensor capable of detecting both the acceleration and the inclination angle of the road surface. The output of the motor is controlled by this work amount.

According to the second aspect of the invention, the amount of work currently required in relation to the road surface inclination angle can be known from the output value of the acceleration sensor capable of detecting both the acceleration and the road surface inclination angle. The output of the motor is controlled by this work amount.

According to the third aspect of the present invention, the upper end of the acceleration sensor is rotatably supported on the vehicle body. Therefore, when the bicycle starts running, the acceleration sensor rotates backward around the support portion. Move. From this rotation amount, the amount of work required at the start of traveling can be known. On the other hand, even when the bicycle approaches an uphill road, the acceleration sensor rotates backward (downward).
This will likewise reveal the amount of work required at that time. Therefore, the output control of the motor can be performed according to the detected work amount. Since it is attached to the bicycle independently of the pedal effort transmission mechanism, there is no risk that the pedal effort cannot be transmitted.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. First, in FIG. 1, 1 is an acceleration sensor and 2 is a speed sensor. Although a specific structure of the acceleration sensor 1 will be described later, when the acceleration or the inclination of the vehicle body changes, the amount of change is output as a digital signal and the proportional signal, that is, an analog signal is output. The speed sensor 2 also has two types: one that outputs the amount of change in the traveling speed of the bicycle as a digital signal and one that outputs the voltage signal (analog signal) corresponding to the amount of change.

The output sides of the acceleration sensor 1 and the speed sensor 2 are connected to the input side of a controller 3 as a work amount calculation circuit. The motor 4 is connected to the output side of the controller 3. With this connection, controller 3
Calculates the work of the bicycle from the input signals from the sensors 1 and 2, and controls the output of the motor 4 based on the calculation result. In this case, the controller 3
The acceleration signal may be used among the output signals of the acceleration sensor 1 and the inclination angle of the road surface may be used.

An acceleration sensor 1 according to the present invention will be described with reference to FIG. 2 showing a front surface and FIG. 3 showing a side surface thereof. This acceleration sensor 1 has a fan-shaped plate 5 having an arcuate outer peripheral shape, and a shaft 6 located at the upper end of the plate 5 for rotatably supporting the plate 5. The plate 5 is regularly provided with a large number of holes 7. There are four rows of holes 7 in the embodiment, one row near the axis 6, two rows next to it, four rows to the third row, and eight rows to the outermost periphery. The larger the number of rows, the smaller the area. The holes 7 are arranged at equal intervals in a plurality of rows as shown in the drawing, and all the rows are arranged on the right side in the drawing.

The light emitting element 8 is sandwiched so as to sandwich the plate 5.
A photo interrupter 10 having the light receiving element 9 and the light receiving element 9 is provided. A light emitting diode is used as the light emitting element 8,
A phototransistor is generally used as the light receiving element 9, but another element may be used. The light emitting element 8 and the light receiving element 9 are provided corresponding to the holes 7 of the plate 5, as shown in FIG. As a result, when the plate 5 rotates about the axis 6, the light beam from the light emitting element 8 is intermittently entered by the hole 7 and enters the light receiving element 9.

As shown in FIG. 4, the acceleration sensor 1 is attached to a position not related to the pedaling force transmission mechanism of the pedal of the bicycle 11, that is, to the luggage carrier 13 provided on the upper portion of the rear wheel 12. It should be noted that this position is selected as the place where it is the most unobtrusive to the person riding the bicycle 11, and even if it is attached to another place, it does not cause any functional problem.

FIG. 4 shows the bicycle 11 climbing a slope having an inclination of an angle θ _S. This will be described later along with the operation. The body of the bicycle 11 has a very general structure. That is, the crank mechanism 15 is provided at the center of the frame 14, and the chain 18 is provided between the sprocket 16 attached to the crank mechanism and the free wheel 17 attached to the rear wheel 12.
It has been passed over. Reference numeral 19 is a pedal, and 20 is a saddle.

Although not shown, the pedal 19 is provided with a pedal switch for detecting that a foot is placed. When an occupant sitting on the saddle 20 places his / her foot on the pedal 19 and rotates the sprocket 16 in a predetermined direction, the bicycle 1
1 goes forward.

A motor 4 is provided in front of the freewheel 17 of the bicycle 11. The motor 4 is a DC motor, and has a speed reducer inside. As shown in FIG. 1, the rotation of the motor 4 is controlled by the controller 3. Illustration of the battery of the power source is omitted.

The power transmission mechanism will be described with reference to FIG.
Reference numeral 21 denotes a rear axle, both ends of which are rotatably supported by the frame 14. A freewheel 17 and a wheel gear 22 are attached to the rear axle 21 with a space therebetween, and a hub 23 of the rear wheel 12 is attached between them. 24 is a spoke. A worm gear 26 is attached to the output shaft 25 of the motor 4 (output shaft of the reduction gear) and meshes with the wheel gear 22.

A speed sensor 2 is provided outside the wheel gear 22.
Is installed, and the bicycle 11 is rotated from the rotation of the rear axle 21.
It is designed to detect the traveling speed of. In this embodiment, the rear axle 21 rotates with respect to the frame 14, but the present invention is not limited to this, and the rear axle 21 can be fixed to the frame 14 to realize the present invention. . In that case, the hub 23 is rotatably supported by the rear axle 21, and the free wheel 17 and the wheel gear 22 are attached to the hub 23.

The principle of acceleration calculation when the plate 5 of the acceleration sensor 1 of the present invention is considered as a pendulum will be described with reference to FIG. In the acceleration sensor 1, the plate 5 detects the sum θ of the inclination angle θ _S generated by the inclination of the slope and the inclination angle θ _G generated by the acceleration of the bicycle 11. The acceleration G _S due to the slope of the slope and the acceleration G _{C of the} bicycle 11 can be calculated by the following equation. Let m be the weight of the pendulum and g be the gravity. G _S = mg tan θ _S G _C = mg tan θ _G Here, the sum G of accelerations is: G = G _S + G _C = mg (tan θ _S + tan θ _G ) = mg [tan (θ _S + θ _G ) × (1 + tan θ _S + t
an θ _G )]. Where θ _S <15 ° and θ _G <15 °, 1 >>
Since tan θ _S × tan θ _G , G≈mg tan (θ _S + θ _G ) = mg tan θ. That is, the output of the motor 4 is maximized when the inclination angles θ _S and θ _G are 15 ° or more.

FIG. 7 is a graph for calculating the work of the bicycle 11 based on the speed and acceleration of the bicycle 11. From this graph, if the velocity is V and the acceleration is G,
The work amount W can be calculated as shown by the broken line. This graph is a map created from the measured values in consideration of the vehicle body weight.

The operation will be described with reference to the flowchart of FIG. From step S1 of the start, a person who rides on the bicycle 11 depresses the pedal 19 with his / her foot to give a rotational force to the rear wheel 12, and at the same time, turns on a switch (not shown) to rotate the motor 4. When the pedal 19 is stepped on, the pedal switch is turned on (step S2), and it is detected that the passenger is willing to travel. When the bicycle 11 starts traveling, the plate 5 of the acceleration sensor 1 rotates backward about the shaft 6 due to inertia. The amount of rotation corresponds to the acceleration (step S3).

When the plate 5 rotates, a digital signal is generated due to the relationship between the hole 7 and the photo interrupter 10. This signal is input to the controller 3, calculated here, and the sum G of accelerations is obtained from the rotation amount of the plate 5 (step S4). At the same time, the rotation speed C of the wheel (rear wheel 12) is measured by the speed sensor 27 (step S5). When the rotation speed C is measured, the value is multiplied by the circumferential length of the wheel to obtain the traveling speed V of the bicycle 11.
Is calculated (step S6).

If the traveling speed V of the bicycle 11 is calculated,
By applying the value to the graph of FIG. 7, the work amount W can be obtained (step S7). If the work amount W is known, the pedaling force W _F can be obtained by subtracting the output W _{m of the} motor 4 from this value (step S
8). The output W _{m + 1} to the motor 4 is calculated by multiplying the pedaling force W _F by the motor auxiliary ratio (the ratio of the motor output to the pedaling force) (step S9). The current passed through the motor 4 is controlled so that the motor 4 outputs W _{m + 1} (step S10).

To determine whether or not the bicycle 11 has started running, it is convenient to attach a switch to the saddle or the steering wheel so that the switch is turned on when the occupant takes a running posture. There is a speed sensor 27
You may make it use the output signal of.

Next, as shown in FIG. 4, the case where the bicycle 11 is approaching an uphill road will be described. Since the plate 5 of the acceleration sensor 1 rotates about the shaft 6, the plate 5 rotates according to the angle even when the bicycle 11 takes the posture shown in this figure. Move. Since the rotation amount is detected by the photo interrupter 10, the same processing as that described with reference to the above-described flowchart is performed below, and the output of the motor is controlled.

When the acceleration sensor 1 is composed of the plate 5 and the interrupter 10 as described above, it is good when detecting the inclination angle of the road surface, but when detecting acceleration, there is a possibility that the acceleration sensor 1 repeatedly rotates in the front-rear direction. As a means for preventing this, the plate 5 is made sufficiently heavy, or an appropriate frictional resistance is given to the portion of the shaft 6 so that the shaft 5 rotates when it receives acceleration, but even if it receives a smaller force. It is possible to prevent it from rotating.

Further, as a completely different structure, a plate having no holes 7 is rotatably provided in a viscous liquid such as oil filled in a container, and a potentiometer is attached to a shaft serving as a center of rotation. It is also possible to change the resistance value according to the rotation angle. In this case, unlike the above embodiment, an analog output signal is obtained.

As another method for avoiding the influence of the plate 5 repetitively rotating, when the acceleration sensor 1 outputs different values before and after the passage of time, the average value thereof may be taken as the output signal. .

[0036]

Since the present invention is the auxiliary power control method and apparatus for a power bicycle constructed as described above, the mechanism for transmitting the pedal effort to the rear wheels is the same as that of a general bicycle. Parts and the like can be commonly used. Since the driving force transmission mechanism does not have the pedaling force detector, the failure rate of the transmission mechanism can be reduced. Further, when the pedal effort detection unit fails, the auxiliary power of the motor disappears, but the driving force from the pedal effectively acts and does not hinder traveling. When approaching an uphill road, the acceleration sensor detects an increase in the load due to the slope as an increase in acceleration before the pedal effort increases, so that the auxiliary power of the motor can be exerted earlier.

[Brief description of drawings]

FIG. 1 is a circuit diagram of an embodiment of the present invention.

FIG. 2 is a front view showing an example of an acceleration sensor according to the present invention.

FIG. 3 is a side view including a light emitting element and a light receiving element of FIG.

FIG. 4 is a side view of a power bicycle to which the present invention is applied.

5 is a plan view showing an enlarged main part of FIG. 4. FIG.

FIG. 6 is an explanatory diagram for explaining the operating principle of the acceleration sensor.

FIG. 7 is a graph showing the relationship between bicycle speed and work load.

FIG. 8 is a flow chart for explaining the operation.

[Explanation of symbols] 1 acceleration sensor 2 speed sensor 3 controller 4 motor 5 plate 6 shaft 7 hole 10 photo interrupter 11 bicycle 12 rear wheel 16 sprocket 17 freewheel 18 chain 19 pedal 21 rear axle 22 wheel gear 26 worm gear

Claims (3)

[Claims] 1. The amount of work of the bicycle is calculated from the acceleration detected by an acceleration sensor capable of detecting both the acceleration and the inclination angle of the road surface and the speed of the bicycle, and the output of the motor is controlled based on the calculated result. Power control method for power bicycle. 2. The amount of work of the bicycle is calculated from the inclination angle of the road surface and the speed of the bicycle detected by an acceleration sensor capable of detecting both the acceleration and the inclination angle of the road surface, and the output control of the motor is performed according to the calculation result. An auxiliary power control method for a power bicycle, characterized by: 3. An acceleration sensor is formed by a plate rotatably supported at an upper end thereof, an output side of the acceleration sensor is connected to a work amount calculating circuit, and the acceleration sensor is connected to a pedaling force transmission mechanism of a pedal. An auxiliary power control device for a power bicycle, which is mounted on the bicycle independently of the.