JP3276443B2 - Bicycle with electric motor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION This invention is a drive system by the driving system and the electric motor by manual provided in parallel, substantially ratio a driving force by the electric motor to the drive force by human power (hereinafter referred to as pedaling force)
The present invention relates to a bicycle with an electric motor which is controlled as an example .

[0002]

2. Description of the Related Art It is known that a pedaling force is detected and the driving force of an electric motor is controlled in proportion to the magnitude of the pedaling force (JP-A-50-125438, JP-A-56-7659).
0, JP-A-2-74491, etc.).

Here, the pedaling force is usually obtained by converting the pedaling force into a mechanical displacement and electrically detecting the mechanical displacement. For example, when the pedaling force is transmitted to the rear wheels via a chain, a spring is applied to the chain on the tension side in a direction perpendicular to the running direction of the chain, and the pedaling force can be obtained from the amount of displacement of the chain accompanying an increase or decrease in the pedaling force. (JP-A-50-125438).

[0004]

However, when the pedaling force is detected by mechanical displacement as described above, the operation may not be smooth when mud, dust, oil or the like adheres to the movable portion of the detecting means. Such moving parts should be cleaned by daily inspection, but it is common experience that neglecting this cleaning deteriorates the ability of the moving parts to follow the pedaling force.

Since the actual pedaling force P periodically increases and decreases, the detected pedaling force F should be periodically increased and decreased. However, when such a state occurs, even when the pedaling force is not applied, it is considerably large. It is determined that the pedaling force is applied. Therefore, at this time, a large electric drive system output contrary to the driver's intention is generated, and there is a problem that battery consumption is promoted and driving feeling is deteriorated.
It is also conceivable that the driver modifies the pedaling force detecting means to increase the output of the electric drive system. Further, in this type of bicycle, there is a case where the bicycle is stopped with a brake applied at a traffic light or the like. At this time, a situation in which a foot is put on the pedal and a small pedaling force is continuously applied to the pedal can often occur. In this case, the motor output continues to be generated even though it is not necessary, and the battery is wasted.

[0006]

SUMMARY OF THE INVENTION The present invention has been made in view of such circumstances, and an excessive electric drive system output may be generated even when the operation of the movable portion of the treading force detecting means is not smooth or when a modification is made. It is another object of the present invention to provide an electric motor-equipped bicycle that can prevent unnecessary consumption of batteries and prevent a feeling of driving from deteriorating.

[0007]

According to the present invention, it is an object of the present invention to provide an electric motor in which a human-powered drive system and an electric drive system are provided in parallel, and the output of the electric drive system is controlled substantially in proportion to the manual power. a bicycle attached, a pedal pressure detecting means for detecting a pedaling force, CPU
A stepping force change rate detecting means for detecting a stepping force change rate dF / dt from a stepping force measurement value obtained by the stepping force detecting means at every constant time dt, and a time corresponding to the change in the change rate.
And the integrated value of the time counting means is a predetermined value.
And a stop discriminating means for stopping the power assist by the motor when the power exceeds the threshold value.

[0008]

1 is a side view of one embodiment of the present invention, FIG. 2 is a power system diagram thereof, FIG. 3 is a block diagram showing functions of the controller, FIG. 4 is an operation explanatory diagram based on normal pedaling force, FIG. 5 is a diagram showing the pedaling force at the time of abnormality, FIG. 6 is a diagram showing the pedaling force at the time of abnormality, and FIG. 7 is an operation flowchart.

In FIG. 1, reference numeral 10 denotes a main frame, which extends rearward from a head pipe 12 obliquely downward and rearward.
4 axles. A seat tube 16 is fixed substantially perpendicular to the main frame 10, and a seat post 20 for supporting a saddle 18 is fixed to an upper end of the seat tube 16.

At the lower part of the seat tube 16, there is formed a cylindrical portion 16a which is opened downward, and accommodates a permanent magnet type DC electric motor 22 therein. A power unit 24 is fixed to a lower end of the seat tube 16. The power unit 24 includes a bottom bracket case (hereinafter referred to as a BB case) 26 and a rear stay 28 extending rearward from the BB case 26. The rear wheel 14 is fixed to the rear end of the rear stay 28. The drive shaft 30 (see FIG. 2) is inserted through the right rear stay 28.

A crankshaft 32 is inserted through the BB case 26 of the power unit 24, and a crank 34 is fixed to both ends thereof. The crank 34 has a crank pedal 36,
36 are attached.

The left end of the axle 38 of the rear wheel 14 is fixed to an end plate 28a fixed to the left rear stay 28,
The right end of the axle 38 is fixed to a bevel gear case (not shown) fixed to the right rear stay 28. Axle 38
A rotatable hub (not shown) is rotatably held therein. The rotation of the drive shaft 30 is transmitted to the hub via a bevel gear mechanism and a one-way clutch 42 (FIG. 2).

The power unit 24 transmits the rotation of the crankshaft 32 to the drive shaft 30 via a one-way clutch 44 (FIG. 2).
Bevel gears (not shown) to be transmitted to the vehicle. A planetary gear mechanism is interposed between the crankshaft 32 and the drive shaft 30.

In this planetary gear mechanism, pedaling force is input from the planetary gear, and pedaling force is output to the drive shaft 30 from the ring gear. The pedaling force F is detected by detecting a torque applied to the central sun gear by a potentiometer 46 as a pedaling force detecting means. Motor 2
2 is transmitted to the drive shaft 30 via the one-way clutch 48 and the speed reducer 50.

In FIG. 1, reference numeral 52 denotes a rechargeable battery such as a lead battery, and reference numeral 54 denotes a controller, which are accommodated between the head pipe 12 of the main frame 10 and the seat tube 16. In FIG. 1, reference numeral 56 denotes a vehicle speed sensor for obtaining the vehicle speed S from the rotation speed of the front wheels 58.

The pedal force F detected by the potentiometer 46 control - are input to La 54, this controller - La 54 controls the motor current to generate a motor output or motor torque T _M on the basis of the pedal force F.

The controller 54 is configured as shown in FIG. The motor 22 and the battery 52 form a closed circuit together with the switching circuit 60, and this closed circuit becomes the main circuit 62. The switching circuit 60 includes a thyristor bridge and a transistor bridge. A flywheel diode 64 is connected to the motor 22 in parallel, and a shunt 66 for detecting current is attached to the main circuit 62.

Reference numeral 68 denotes a CPU, and 68a denotes a memory. C
The PU 68 has a function of the traveling control means 68A, and outputs (torque) T _{M of the} motor 22 based on the pedaling force F, the vehicle speed S, and the like.
Is output. That is, the command value i is output so that the output (torque) T _M of the motor 22 is periodically increased and decreased in synchronization with the periodic increase and decrease of the pedaling force F. In addition, constant vehicle speed S
, The motor output T _M may be limited to limit the vehicle speed S.

A gate circuit 70 outputs a gate signal g whose duty ratio changes in accordance with a command value i supplied from the CPU 68. That is, when the command value i increases the motor output TM, the (on-time) of the gate signal g
The value of / (off time + on time) (duty) is increased.

The gate signal g output from the gate circuit 70 based on the command value i is sent to each switching element of the switching circuit 60 to selectively turn on / off each switching element.

In FIG. 3, reference numeral 72 denotes a CPU 68
Is a pedal force change rate detecting means, with respect to time of the pressing force F
The change rate, that is, the time derivative dF / dt is detected. In the depression force change rate detecting means 72, a difference of the measurement value F _a tread force F detected every minute time dt by the potentiometer 46 as shown in FIG. 4, i.e. the measurement value previously detected (previous value)
F (t−dt) and the next detected value (next value)
The difference from F (t) is determined, the sign of the difference is determined, and a flag is output. Therefore, while the measured value Fa of pedal force increases the sign of this difference + becomes, the while conversely decreased - will, because a change in this difference becomes zero difference unless, flag 4
When the difference changes from 0 to + as shown in-, from-to +,
When the difference changes from 0 to-, it changes from + to-.

In FIG. 3, reference numeral 74 denotes a time measuring means, which is fixed.
By adding a constant value every time dt, the pedaling force F
The period T is obtained. As in practice shown in FIG. 4, the flag from + - from the time t ₁ which changes, - is integrated a predetermined value at regular time intervals dt in between time t ₂ which changes +
Thereby, the time of half T / 2 of the cycle T is measured.

Reference numeral 76 denotes a stop determining means, which is a calculated integrated value.
Is in the range of the proper cycle T or T / 2 , and if it is out of the proper range, the drive of the motor 22 is stopped. Actually, integration starts every half cycle (T / 2)
The integrated value of the counter is compared with a predetermined value, that is , an integrated value corresponding to the longest limit of T / 2 that can be taken in a normal state. If the integrated value is equal to or less than the integrated value corresponding to the longest limit , it is determined that the stop is unnecessary. For example, as shown in FIG. 5, when the integrated value of the time measuring means exceeds the integrated value (predetermined value) corresponding to the longest limit of half the proper period T / 2 , it is determined that the stop is necessary, and the integrated value is determined. Immediately after exceeding the integrated value (predetermined value) corresponding to the longest limit of the T / 2 cycle, power assist by the motor is stopped.

It should be noted in this embodiment, rather than determining the motor output T _M as it is force F measured values F _a pedal effort, the difference between the treading force measuring value F _a and a predetermined depression force lower limit value F _m (F _a
Seeking -F _m) as depression force instruction value F _i, seeking motor output T _M on the basis of the instruction value F _i. Reference numeral 78 in FIG. 3 denotes a pedaling force instruction value calculating means for performing this calculation.

[0025] Here the depression force lower limit value F _m may be set close to the upper limit of the treading force measuring value F _a in the normal operating range just after the power is turned on, the minimum value for each cycle of the pedaling force measurement value F _a in accordance with the running Rewrite to gradually approach. This calculation is performed by the pedaling force lower limit value calculating means 80. The circle mark in the column of the pedal effort lower limit value comparison in FIG. 4 indicates the timing at which this rewriting is performed.

The difference between the thus depressing force limit value F _m (F _a -F
By obtaining the motor output T _M a _m) as depression force instruction value F _i, the motor output T _M be entered event excessive treading force measuring value F _a can be prevented from becoming excessive. Because the depression force limit value F _m is the first large value, because then rewritten by slide into converged to near the minimum value of the treading force measurement values F _a. Thus if pedaling force measurement value F _a is changed at a smaller constant than depressing force limit value F _m as in FIG. 6, pedal force instruction value F _i is negative, which requires stopping.

Next, the operation will be described with reference to FIG. First C
PU68 sets the flag to + (step 100), sets the pedal force limit value F _m (step 102), performs other initialization process. Then, the treading force measurement is started, and a certain time d
reading writing the treading force measuring value F _a per t (step 104).
The pedal force instruction value calculating means 78 calculates the pedal force instruction value F _i = (F _a −F
The calculation of _m ) is constantly repeated at intervals of a predetermined time dt (step 106). The running control means 68A controls the motor output T _M on the basis of the depression force instruction value F _i.

The depressing force changing rate detecting means 72 pedaling force measurement value F _a
(The next time value−the previous value) is obtained (step 108). If the pedaling force is decreasing, this difference is assumed to be negative (step 110), and it is checked whether or not the difference matches the flag set in step 100. (Step 112). In this case, since they do not match, the flag is rewritten from + to-(step 114). Then, the timer 74 starts counting by the counter (step 116).

Then, returning to step 106, the pedal force indication value F _i is rewritten to control the motor output T _M , while the time d
After t, the difference is obtained (step 108). If the pedaling force is decreasing, the difference is negative (step 11).
0) because it matches the flag (-) (step 11).
2) Add a constant value to the counter (step 11)
8). Stop judging means 76 sets the integrated value of the counter to the longest limit
Is compared with the predetermined value , and if it is equal to or smaller than the predetermined value (step 120), the process returns to step 106. Since the difference is negative and coincides with the flag (-) while the pedaling force is decreasing (step 1).
08, 110, 112), during which time the counter is incremented. While the pedal effort is decreasing, the accumulated value of the counter reaches the longest limit.
When the value exceeds a predetermined value , the flag is changed to + (step 122), the counter is reset to 0 (step 124), and the assist by the motor 22 is stopped (step 126).

If the pedaling force changes to increase before the integrated value of the counter corresponding to the period T or T / 2 reaches the predetermined value corresponding to the longest limit, the difference becomes positive (step 10).
8, 128). Since the flag immediately before is-, it is determined that the two do not match (step 130), and the flag is rewritten to + (step 132). Then the counter is reset to 0 (step 134), it determines whether it is necessary to rewrite the depression force limit value F _m (step 136).

The rewriting of the depression force lower limit value F _m is carried out in the vicinity of the minimum value of the force F as described in FIG. 4, treading force measuring value at Nearby (previous value) F _a is greater than the depression force limit value F _m If not rewritten. If smaller the pedaling force measurement value seeking the arithmetic mean of the (previous value) F _a, a pedal pressure lower limit value, this is a new pedal force limit value F _m (step 138). Thus pedaling force measurement value F _a minimum pedal force limit value F _m between less than the repeats rewriting to reduce gradually the depression force limit value F _m for each cycle.

From the time t ₁ that changes, - - [0032] In this embodiment flag from + is that the timing period until time t ₂ which changes from the +, the invention is not limited thereto. Flag - the next cycle of the flag from the time t ₂ which changes from + is +
From - may be counting up time t ₁ which changes, in this case is to set a flag in step 100 to the negative in the flowchart of FIG.

Further the time of rewriting of the depression force lower limit value F _m, may be obtained depressing force limit value F _m using although a simple arithmetic average of the F _a and F _m a weighted average of other ratios.

[0034]

According to the first aspect of the present invention, as described above, the increase / decrease of the tread force measurement value is monitored, and the change rate dF / dt is changed.
If the integrated value of the counter that started integration in response to the value exceeds a predetermined value ( the integrated value corresponding to the longest limit ) , the power assist by the motor is stopped. In this case, the motor output does not become excessive, the battery is not wastefully consumed, and the driving feeling does not deteriorate. Further, when the foot is put on the pedal and the pedal is continuously applied with a small pedaling force while the brake is applied, for example, when waiting for a signal, the motor output is not generated, so that the battery is not wasted.

[Brief description of the drawings]

FIG. 1 is a side view of one embodiment of the present invention.

Fig. 2 Power system diagram

FIG. 3 is a block diagram showing functions of a controller.

FIG. 4 is an explanatory diagram of an operation in a normal state.

FIG. 5 is a diagram illustrating an example of a measured value of a pedaling force at the time of abnormality.

FIG. 6 is a diagram showing another example of the pedaling force measurement value at the time of abnormality.

FIG. 7 is an operation flowchart.

[Explanation of symbols]

Reference Signs List 14 rear wheel 22 electric motor 36 crank pedal 46 potentiometer as pedaling force detecting unit 54 controller 68 CPU 72 pedaling force change rate detecting unit 74 time counting unit 76 stop discriminating unit F pedaling force Fa pedaling force measured value

Continuation of the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) B62M 23/02 B62K 11/00 B62M 7/06

Claims (1)

(57) [Claims] 1. A stepping force detecting means for detecting a stepping force in a bicycle with an electric motor which is provided with a human driving system and an electric driving system in parallel and controls the output of the electric driving system substantially in proportion to the stepping force by the manpower. It is formed by CPU for a certain time dt
At the same time, the change in the treading force from the treading force measurement value obtained by the treading force detecting means
A pedaling force change rate detecting means for detecting the conversion rate dF / dt ;
A bicycle equipped with an electric motor, comprising: a time- measuring means for starting time- measurement in response to a change in the rate of change; and a stop determination means for stopping power assist by a motor when an integrated value of the time-measuring means exceeds a predetermined value. .