JPS5932384A - Automatic variable speed gear - Google Patents

Abstract

PURPOSE:To reduce impact force in case of the changeover of a transmission gear ratio by combining a speed reducer when a wheel and a DC motor are conformed with each other and turned at a predetermined ratio. CONSTITUTION:Analog switches 25, 29 are selected on operation at high speed, and the DC motor 1 is controlled at constant velocity while using an output from a speed command device 30 as a speed command value. When the number of revolution of the wheel is made smaller than the changeover speed of the transmission gear ratio, analog switches 26, 28 are selected, and the DC motor 1 is turned while using the number of revolution of the wheel as a speed command. When the number of revolution of the DC motor 1 is kept within a predetermined range to the speed command of the wheel, a motor 64 is driven, and a variable-speed mechanism is changed over to a reduction gear ratio for low speed. When a changeover is completed, the analog switch 29 is selected, and the DC motor 1 is controlled at constant velocity by the speed command device 30 while the conduction of the motor 64 is stopped.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an automatic transmission that automatically switches a reduction ratio.

The prior art will be explained using FIGS. 1(a) and 1(b).

The horizontal axis of the graphs in FIGS. 1(a) and 1(b) is the driving torque M of the wheels of the electric vehicle, and the vertical axis is the rotation speed N of the wheels of the electric vehicle. Symbol 101 is a torque/rotational speed curve when the reduction ratio is switched to high speed, and symbol 102 is a torque/rotational speed curve when the reduction ratio is switched to low speed. Torque M1 is the torque at the intersection of curve 101 and curve 102. Torque M2°M8 is the limit torque when the electric motor is provided with a current limiter.

Examples of electric vehicles that use an electric motor to obtain driving force include electric wheelchairs for physically disabled people, electric tricycles for the elderly, and electric transport vehicles for transporting luggage. Because electric vehicles have large load fluctuations, they are generally equipped with a transmission. When an electric vehicle starts and accelerates, it starts by switching the reduction ratio to low speed, and when it reaches torque T2, which is the intersection of curve 1 and curve 2 shown in FIG. 1(a), the reduction ratio is switched to high speed. In particular, it has the disadvantage that it requires driving skill to obtain the maximum acceleration force.

When switching the reduction ratio from high speed to low speed, if the rotation speed of the wheels is high, the motor will be rotated by the motor guard wheels, the reverse induced voltage of the motor will become higher than the power supply voltage, and a braking current will flow, resulting in braking. This has the disadvantage of providing a shocking braking force and a sense of danger to the driver.

A control transistor is used to control the power of the motor, and this is especially noticeable when a current limiter is installed to protect against the maximum collector current rating of the transistor and to prevent deterioration due to rapid discharge of the battery. When the ratio is changed to high speed and the load torque is greater than the drive torque M2 caused by the current limiter, there is a drawback that the drive torque is insufficient and the motor stops. Also, in some cases, the electric vehicle may move backwards, creating a danger for both the driver and pedestrians. Also, frequent use of low-speed reduction ratios has the disadvantage of slow speed reduction.

Therefore, on roads with many slopes, it is necessary to shift gears frequently depending on the road conditions.

If the gears are not shifted optimally, the above-mentioned inconveniences will occur while driving, but for disabled people using electric wheelchairs and elderly people using electric tricycles, it is impossible to change gears according to road conditions while driving. .

In order to eliminate these drawbacks, the present invention selects the optimum reduction ratio according to the driving condition and automatically changes speed.
In addition, in order to reduce the impact force at the time of switching, the reduction gear is connected when the wheels and the DC motor are rotating at a predetermined ratio. do.

FIG. 2 shows an embodiment of the present invention, and reference numeral 1 indicates a DC motor for driving an electric vehicle. Symbol 2.3 is a semiconductor switching element (for example a transistor). Number 4.5 is a flywheel diode. Symbol 6 armature 1! This is a resistance for detecting flow. Transistor 2, DC motor 1, and resistor 6 are connected in series. Flywheel diode 5 is connected in parallel with transistor 2. Transistor 3 and flywheel diode 4 are DC motor l
and resistor 6 in parallel. Symbol 7 is an OP amplifier, which together with resistors 8, 9, 10, and 11 constitutes a differential amplifier circuit. I pin number 12 is an absolute value circuit and O
The output of the P amplifier 7 is used as an input. Reference numeral 13 denotes an OP amplifier that amplifies the difference between the output of the absolute value circuit 12 and the voltage Vl. Symbol 14 is a resistor and symbol 15 is a diode. Symbol 16 is a Schmidt Drika circuit. The output of the OP amplifier 13 is input to a non-inverting input of a Schmitt trigger circuit 16 via a resistor 14. A non-inverting input of the Schmitt trigger circuit 16 is connected to ground potential via a diode 15. Symbol 17 is a NAND circuit, and symbol 18 is an AND circuit. The output of the Schmint trigger circuit 16 is connected to the base side of the transistor 2 via the NAND circuit 17f and to the base side of the transistor 3 via the AND circuit 18. Reference numeral 21 denotes an absolute value circuit which inputs the voltage of the resistor 6 and inputs it to the inverting input of the Schmitt trigger circuit 16. symbol 19
is a comparison circuit, and symbol 20 is an inverter circuit. The comparison circuit 19 receives the output of the OP amplifier 7 and outputs it to the input of the AND circuit 18. Further, the output of the comparison circuit 19 is connected to the input of the NAND circuit 17 via an inverter circuit 20. Symbol 22 is a rotation speed detection device (for example, a tacho generator) that detects the rotation speed of the DC motor l.

The symbols 23 and 24 are resistors that divide the output voltage of the tacho generator 22. Symbols 25 and 26 are analog switches. The output of the tacho generator 22 is input to the inverting input side of the OP amplifier 70 via an analog switch 25. The output of the tacho generator 22 is voltage-multiplied by resistors 23 and 24, and the voltage-divided output is input to the inverting input side of the OP amplifier 70 via an analog switch 26. Symbol 27 is a rotation speed detection device f that detects the rotation speed of the wheels of the electric vehicle.
lt (e.g. tacho generator). Symbol 28.2
1) is an analog switch, and symbol 30 is a speed command device that commands the speed of the wheels. The output of the tacho generator 27 is input to the non-inverting input side of the OP amplifier 7 via an analog switch 28. The speed command device 30 is inputted to the non-inverting input side of the OP amplifier 7 via the akilog switch 29, and zJ is input. Symbol 31 is a switch device. Symbols B and CD are signal terminals of the switch device 31. When a high-speed reduction ratio is selected in the transmission mechanism, the terminal B is at a high level, and when a low-speed reduction ratio is selected, the terminal B is at a high level.

In the middle, the terminal C becomes a no-low level. symbol 32
is a speed change command device. Symbol 33 is a comparison circuit. The comparison circuit 33 sets the output of the tacho generator 27 to a predetermined value V2.
It is compared with. Symbols 34 and 35 are AND circuits, and symbols 36 and 37 are inverter circuits. Symbol 38 is an RS flimp circuit. Symbol 39 is resistance and symbol 40
is a capacitor. Symbol 41 is a buffer circuit. The output of the comparison circuit 33 is inputted to the set terminal of the flip-flop circuit 38 via the AND circuit 34, and is inputted to the reset terminal via the inverter circuit 36 and the AND circuit blade. The output of the flip-flop circuit 38 is input to the input of a buffer circuit 410 via an integrating circuit constituted by a resistor 39 and a capacitor 40. The output of the buffer circuit 41 is input to the input of the AND circuit 35 and then to the input of the AND circuit 34 via the inverter circuit 37. The symbol is 47-, the inverter circuit symbol 43.44 is an AND circuit, and the symbol 45 is an OR circuit. AND circuit 43 performs an AND operation between the output of terminal B of switch device 31 and that output of the flip-flop circuit. AND circuit 44 is switch device 131
The output of the terminal 1 and the output of the inverter circuit C, which is the negative of the output of the flip-flop circuit 38, are ANDed. The OR circuit 45 performs an OR operation on the outputs of the AND circuits 43 and 44. The output of the OR circuit 45 is connected to the control terminal of the analog switch 290 and the inverter circuit 4
6 to a control terminal of an analog switch 28. Symbol 47 is an inverter circuit, symbol 48 is an AND circuit, and symbol 49 is an OR circuit. The output of the flip-flop circuit 38 is input to one input of the AND circuit 48,
The output from the output terminal of the switch device 31 is input to the other input of an AND circuit 48 via an inverter circuit 47. The output of the AND circuit 48 is input to one input of the OR circuit $49, and the output of the output terminal B of the switch device 31 is input to the other input. Output analog of OR circuit 49 -
-8- It is input to the control terminal of the switch 250 and is also input to the control terminal of the analog switch 26 via the inverter circuit 56. Symbol 57 is the OP amplifier circuit and resistance path, 5
9.60161 constitutes a differential amplifier circuit.

The inverting input side of the OP amplifier 57 receives the output of the tacho generator 27, and the non-inverting input side receives a value corresponding to the output of the tacho generator 22. Symbol 62 is an absolute value circuit which inputs the output of the OP amplifier 57. A comparison circuit 63 compares the output of the absolute value circuit 62 with a predetermined value Va. The symbol 64 is a DC motor for driving the speed change mechanism. Symbol 65.66.67
．． A transistor 68 serves as a transistor bridge circuit to supply current to the DC motor 64 in both directions.

Symbol 69 is an inverter circuit, and symbol 70 is an AND circuit. The input of the AND circuit 70 is the flip-flop circuit 38
The output of the terminal B of the switch device 31 is inputted via the inverter circuit 69. Symbol 71 is an AND circuit, and symbol 72 is an inverter circuit. The input of one output of the AND circuit 71 is inputted with the output of the AND circuit 70. The output of the AND circuit 71 is connected to the base side of the transistor 66 and also to the base side of the transistor 670 via an inverter circuit 72. Symbol 73 is an inverter circuit, and symbol 74 is an AND circuit. The AND circuit 740 inputs the output of the flip-flop circuit %38 via the inverter circuit 42, and the switch device! The output from the terminal t31 is input via the inverter circuit 73. Symbol 75 is an AND circuit, and symbol 76 is an inverter circuit. AND circuit 75 is AND circuit 74
The output of is used as one input. The output of the AND circuit 75 is connected to the base side of the transistor 68 and also to the base side of the transistor 650 via an inverter circuit 76. Symbol 77 is an inverter circuit.
8 is an OR circuit. One input of the OR circuit 78 is the output of the terminal C of the switch device 31 via the inverter circuit 77, and the other input is the output of the comparison circuit 63. The output of the OR circuit 78 is the AND circuit 71 and 7
50 external force inputs, respectively.

The constant speed control operation of the DC motor 1 in FIG. 2 will be explained in detail using FIG. 3. The vertical axis of the graph in FIG. 3(a) is the absolute value of the current flowing through the DC motor 1, and the horizontal axis of the graph is the time T.

Symbols 90a and 90b are Schmitt, trigger circuit 16
These are the upper and lower slice levels. Symbol 91 is the 11th waveform of the electric motor 1.

When the output of the comparison circuit 19 is low level, the output of the AND circuit 18 is low level and the transistor 3 is cut off, but one of the inputs of the AND circuit 17 is high level, so the output of the Schmitt trigger circuit 16 is Yo,? ) The conduction and cutoff of the transistor 2 are controlled. When transistor 2 is turned on, the armature current gradually increases downward due to the inductance component of the armature coil. Therefore, the voltage at one end of the resistor 6 increases in the positive direction, and the output of the absolute value circuit 21 also increases in the positive direction. When the voltage rises and exceeds the upper slice level 90a of the Schmitt trigger circuit 16, the output of the Schmitt trigger circuit 16 becomes low level, and the output of the AND circuit 17 becomes high level, and the transistor 2 is cut off. When the transistor 2 is cut off, the magnetic energy stored in the armature coil of the motor 1 is discharged via the flywheel diode 4, and the m-pendulum current gradually decreases. Therefore, the voltage at one end of the resistor 6 decreases in the positive direction,
The output of the absolute value circuit 21 also falls in the positive direction. Descend and Schmidt.

When the voltage drops beyond the lower slice level 90b of the trigger circuit 16, the output of the Schmitt trigger circuit 16 becomes high level, the output of the AND circuit 17 becomes low level, and transistor 2 becomes conductive.

When transistor 2 becomes conductive, the armature current increases downward. Thus, the armature current becomes a pulsating flow determined by the hysteresis of the Schmidt trigger circuit 16.

When the output of the comparator circuit 19 is at a high level, the output of the AND circuit 17 is at a high level (9), and the transistor 2 is turned off quickly, but one of the inputs of the AND circuit 18 is at a high level, so the Schmitt trigger circuit 16 According to the output? ) The conduction and cutoff of the transistor 3 is controlled. When the transistor 3 becomes conductive when the reverse induced voltage of the motor 1 is generated upward, the armature current of the motor 1 flows upward.

The electric motor 1 therefore generates a braking torque. The armature current gradually increases upward due to the inductance component of the armature coil. Therefore, the voltage at one end of the resistor 6 increases in the negative direction,
The output of the absolute value circuit 21 increases in the positive direction. Schmidt rises.

When the Schmitt pulse rises above the upper slice level 90a of the trigger circuit 16, the output of the Schmitt trigger circuit 16 becomes low level, the output of the AND circuit 18 also becomes low level, and the transistor 3 is cut off.

When the transistor 3 is cut off, the magnetic energy stored in the armature coil of the motor 1 is regenerated to the power supply via the flywheel diode 5, and the armature current gradually decreases.

Therefore, the voltage at one end of the resistor 6 decreases in the negative direction, and the output of the absolute value circuit 21 decreases in the positive direction. When the voltage falls and exceeds the lower slice level 90b of the Schmitt trigger circuit 16, the output of the Schmitt trigger circuit 16 becomes a high level, the output of the AND circuit 18 becomes a high level, and the transistor 3 becomes conductive.

When transistor 3 becomes conductive, the armature current increases upward again. The armature current thus becomes a pulsating flow determined by the hysteresis of the Schmidt trigger circuit 16.

As can be understood from the above explanation, if the amplification factor of the absolute value circuit 12 is 1, the output voltage of the OP amplifier 7 is -V1.
and Vl, Schmitt trigger circuit 1
Since the output of transistor 6 is at a low level and transistors 2 and 3 are cut off, during the transition between driving and braking,
A dead zone of 2V+ can be provided. The inverting input side and the non-inverting input side of the OP amplifier 70 are controlled to match υ, and when the rotational speed of the tacho generator 220 decreases and the output falls, the output of the OP amplifier 7 rises and a positive voltage V'+ When the rotation speed exceeds , the comparator circuit 19 selects the cyand circuit 17, and a current flows downward through the DC motor 1 to produce a driving torque, thereby suppressing a decrease in the number of revolutions. When the rotational speed of the tacho generator 220 increases and the output increases, the output of the OP amplifier 7 decreases and becomes a negative voltage -V.
When the voltage exceeds l, the comparator circuit 19 causes AND circuit 1
8 is selected, and current flows upward through the DC motor l to produce braking torque, suppressing the increase in rotational speed. Therefore O
The DC motor is maintained at 10 rotations near the rotation speed corresponding to the set value determined on the non-inverting input side of the P amplifier 7.

In FIG. 3(b), symbols 131 a, 131
b, 131c are switches. Symbol 105 is a lever.

Symbols 105a, 105b, and 105c are salient pole portions of the lever 105, and symbol 105d is a rack gear. Switches 131a, 131b, 131c
and salient pole portion 105a.

The position of the lever 105 is detected by 105b and 1.05c. Symbol 107 is a gear and electric motor 64 (
It is connected to the output shaft (shown in Figure 2). symbol 106a,
Guide rollers 106b, 106c, and 106d regulate the movement of the lever 105. ! When a current is applied to the movator 64 to the right, the lever moves to the right.1-1 When a current is applied to the left, the lever 105 moves to the left. Operate the transmission mechanism by lever 105,
When the lever 105 moves to the right, it becomes a low speed reduction ratio, and when it moves to the left, it becomes a high speed reduction ratio.

The horizontal axis of the graph in FIG. 3(c) is the drive torque T of the wheels of the electric vehicle, and the vertical axis p1 is the rotation speed N of the wheels of the electric vehicle. The same symbols as in FIG. 1 indicate the same members and the same effects, so the explanation will be omitted. Symbol N1 is a predetermined rotation speed for selecting a reduction ratio for high speed or low speed. When the rotation speed is greater than N1, it is used for high speed use, and when it is smaller than NX, it is used for low speed use. By providing a hysteresis characteristic to the predetermined rotational speed N1, it is possible to prevent the disadvantage that the gears are alternately switched when the set rotational speed is N1.

When a high-speed reduction ratio is selected, the output terminal A of the flip-flop circuit 38 is at a high level, so the output of the AND circuit 34 is at a low level, and the AND circuit 35 is selected. When the rotation speed of the wheel decreases below Nl, the 17- output of the comparator circuit 33 becomes low level. Therefore, the output of the AND circuit 35 is not at a high level, and the flip-flop circuit 38 is reset, so that the output terminal A of the flip-flop circuit is at a low level. Since the output of the AND circuit 34 is at a low level for a predetermined time due to the time constant circuit of the resistor 39 and the capacitor 40, the flip-flop circuit 38 is not turned on even if the output of the comparison circuit 33 is at a high level. Therefore, in the process where the wheel rotation speed falls below the rotation speed N1 and switches to the low speed reduction ratio (for example, while driving down a slope), even if the wheel rotation speed rises above N1, the low speed reduction ratio is switched. The switching operation continues and is completed. If the rotational speed of the wheels continues to rise above N1 even after a predetermined period of time has elapsed using the time constant circuit, the flip-flop circuit A is set and the output terminal A is set to E level, and the operation of switching to a high-speed reduction ratio is started. Ru. The case of switching from low speed to high speed is also the same as the above description, so the description will be omitted.

By adding an integrating circuit to the non-inverting input side of the comparator circuit 33, the influence of the output ripple of the converter generator 27 can be reduced.

FIG. 3(d) is a timing chart of the circuit operation of FIG. 2. Graph A is a timing chart of the output of the flip-flop circuit 38. Graphs B, C, and D indicate the switch 131a that operates as the lever 106 moves left and right.
, 131 b, and 131 c are timing charts. Graph E is a timing chart showing whether analog switch 28 is selected or analog switch 29 is selected. Graph F is a timing chart showing whether the analog switch 25 or the analog switch 26 is selected. Graph G is a timing chart showing whether the rotation speed of the DC electric motor 41 itl and the rotation speed of the wheels are at a predetermined ratio. Graph H is electric motor 6
4 is a timing chart for cutting off the current supply. The graph is a timing chart for applying current to the electric motor 64 in the right direction. Graph J is a timing chart for applying current to the motor 64 in a leftward direction.

Before time T1, a high-speed reduction ratio is selected in the transmission mechanism, and terminal A is at a high level. Lever 105 is located on the left side, switch 131a is pressed and switches 131b and 131c are open.

Therefore, the terminal B of the switch ft31 (7) is at a high level, and the terminals C and D are at a low level. Terminal A and terminal B
is at a high level, so the output terminal E of the OR circuit 45 is also at a high level, selecting the analog switch 29. Since the terminal B of the switch device 31 is at a high level, the output terminal F of the OR circuit is at a high level and the analog switch 25 is selected. Second speed control is being performed.

Since the terminal A of the flip-flop circuit 38 is at a high level, the output terminal I of the AND circuit 75 is at a low level.

Furthermore, since the output terminal B of the switch device is at a high level, the output terminal J of the AND circuit 71 is at a low level. Therefore, no current is applied to the electric motor 64.

At time T1, a command for switching the transmission mechanism to a low speed reduction ratio is generated, and the output terminal A of the flip-flop circuit 38 becomes low level. Therefore, the output terminal E of the OR circuit 45 also becomes low level, so the analog switch 28
is selected, and the rotation speed of the DC motor 1 is set based on the output of the tough generator 27 that detects the rotation speed of the wheels.

Since the output terminal A of the flip-flop circuit 38 is at a low level and the output terminal of the switch device is at a low level, the output of the AND circuit 74 is at a high level, and the output terminal C of the switch device 31 is at a low level, so the OR circuit 78
Since the output terminal H of the AND circuit 75 is at a high level, the output terminal H of the AND circuit 75 is at a high level, so that the electric motor 64 is energized in the right direction. Therefore, the lever 105 moves rightward.

At time T, the rightward movement of the lever 105 opens the switch 131a, and the output of the output terminal B of the switch device ff31 becomes low level.

Since the output terminal B of the switch device fM31 is at a low level and the output of the flip-flop circuit 13B is at a low level, the output terminal F of the OR[g1149 is at a low level 21-, and the analog switch 26 is selected. Therefore, the DC motor 1 is rotated at a low speed reduction ratio using the rotational speed of the wheels as a speed command. However, due to the moment of inertia of the DC motor 1, etc., it takes time for the rotational speed of the wheels and the rotational speed of the DC motor 1 to become a reduction ratio for low speed. The output terminal G of the comparator circuit 63 remains at a low level until the rotational speed falls within a predetermined range.

At time T8, the lever 105 moves further to the right, and the switch 131b is pressed by the salient pole portion 105b.
The output terminal C of the switch device 31 becomes high level. Since the output terminal C is at a high level and the output terminal G of the comparison circuit 63 is at a low level, the output terminal H of the OR circuit 78 is at a low level, and the output terminal I of the AND circuit 75 is at a low level.

Therefore, the DC motor 640 is de-energized. Therefore, the rightward movement of lever 105 is stopped.

At time T4, the rotational speed of the DC motor 1 falls within a predetermined range with respect to the wheel speed command, and the output terminal G of the 99-comparison circuit 63 becomes the NO level.

When the output terminal G becomes high level, the output terminal H of the OR circuit 78 also becomes high level, and the output terminal CH of the AND circuit 75 also becomes high level. Therefore, since the electric motor 64 is energized rightward again, the lever 105 is also moved rightward again.

At time T5, the lever 105 is moved rightward, and the cisinch 131b is opened by pressing the salient pole portion 105b. Therefore, the output terminal C of the switch device 31 is at a low level υ, and the output terminal H of the OR circuit 78 remains at a high level, so that the electric current $64 remains energized in the right direction. The lever 105 moves further to the right.

At time T6, the rightward movement of the lever 105 causes the cis inch 131, C to be pressed by the salient pole portion 105C.
The output terminal of the switch rJ/1t31 becomes the NO level. Since the output terminal remains constant, the output of the AND circuit also becomes 1 level, and the analog switch 29
is selected, and the DC motor 1 is controlled at a constant speed by the speed command device 30. Since the output terminal 1 of the switch device 31 becomes high level, the output terminal 2 of the AND circuit 75 becomes low level 9, and the rightward current supply to the motor 64 is stopped.

Since the lever 105 has moved to the right, the reduction ratio for low speed is selected in the transmission mechanism, and the process of changing the speed of the transmission mechanism from high speed to low speed is completed. The operation of switching from a low-speed reduction ratio to a high-speed reduction ratio is the same as the above-mentioned case of switching from a high-speed reduction ratio to a reduction ratio, so a description thereof will be omitted.

FIG. 4(a) is an embodiment of the circuit 140 shown in FIG. Symbol 151 is a diode, symbol 152 is a resistor, and symbol 153 is a capacitor. Symbol 154 is a buffer circuit. When the voltage at the input terminal 140a changes from low level to high level, the output terminal 140a changes after a predetermined period of time.
b becomes high level. Therefore, by adding the circuit 140, no torque is transmitted from the DC motor 1 to the wheels at the end of the υ shift, so that the connection can be smoothly performed.

FIG. 4(b) shows an embodiment of the circuit 141 shown in FIG. Symbol 155 is a diode, symbol 156 is a capacitor, and symbol 157 is a resistor. Symbol 158 is a buffer circuit. Input terminal 141ac) When the voltage changes from high level to low level, output terminal 141b after a predetermined period of time has passed.
becomes low level.

Circuit 142 is similar to circuit 141. Therefore, by adding the circuits 141 and 142, the electric motor 64 is energized for a predetermined period of time even after the speed change is completed, so that the speed change can be performed completely.

Another embodiment of the speed change command device will be described with reference to FIG. The same symbols as in FIG. 2 indicate the same members and the same effects, so the explanation will be omitted. Symbol 160 is a speed change command device. Symbols 161 and 162 are comparison circuits. Comparison circuit 1
Reference numeral 61 compares the output of the absolute value circuit 21 with a predetermined voltage V4. The comparison circuit 162 compares the output of the absolute value circuit 21 and a predetermined voltage V. DC motor 1
When the armature current decreases and exceeds the first set value (corresponding to V4), the output of the comparator circuit 161 becomes high level, or the output of the 9 flip-flop circuit 25- becomes high level. An operation is performed to select the ratio, which becomes the reduction ratio for high speed. DC motor 1
When the armature current increases and exceeds the second set value (corresponding to V5), the output of the comparator circuit 162 becomes high level and the shift flip-flop circuit 38 is reset and the output becomes low level. An operation is performed to select the reduction ratio for low speed. Further, the output of the absolute value circuit 21 is sent to the comparison circuit 161 via an integrating circuit (-).

Inputting 162K is effective because it becomes resistant to malfunctions.

In this embodiment, a two-speed transmission was described, but the present invention can also be applied to a multi-speed transmission with three or more speeds. In the embodiment of the speed change command device, torque is detected using armature current, but the object of the present invention can also be achieved using other known methods.

The object of the present invention can also be achieved by selecting a reduction ratio with good efficiency in the range of low continuous use and high speed use. In this embodiment, the DC motor is controlled at a constant speed by a speed command device, but the present invention can also be applied to l.ruq control as a torque command device. Further, the object of the present invention can be achieved by using other well-known Chompa control as the power control for the DC motor. The present invention can also be applied to a control circuit that controls a DC motor using a transistor bridge and performs constant speed control or torque control in both forward and reverse directions.

As explained above, the optimum reduction ratio is automatically selected according to the running condition of the electric motor, so the electric motor can be used to its maximum capacity, and switching to a reduction ratio for high speeds will improve the system. It can produce speed, but because it is for deceleration, the speed is not due to the limit of the power supply voltage, or when going up a slope, if you switch to the reduction ratio for low speed, you can climb it, but it is for high speed. It is possible to eliminate the fact that the drive torque is generated and the motor stops. Especially for people with physical disabilities or the elderly, it is extremely difficult to shift gears according to road conditions. Furthermore, since the wheels and the electric motor rotate in synchronization during gear shifting, there is no impact force during gear shifting, and the shifting is smooth, giving the driver no sense of danger or discomfort, resulting in an extremely comfortable ride. The effect is remarkable.

[Brief explanation of the drawing]

Fig. 1(a) and Φ) are graphs for explaining the conventional technology, Fig. 2 is a circuit diagram of an embodiment of the present invention, and Fig. 3(a) is a portion of the constant speed control circuit of Fig. 2. Graph to explain, 3rd
FIG. 3(b) is a diagram for explaining the switch device 31 in FIG. 2, FIG. 3(C) is a graph for explaining the shift command device 32 in FIG. 2, and FIG. 3(d) is a graph for explaining the shift command device 32 in FIG. A timing chart of the circuit in FIG. 2, FIG. 4(a) is an embodiment of the circuit 140 in FIG. 2, FIG. 4(b) is an embodiment of the circuit 141 in FIG. 2,
FIG. 5 shows other embodiments of the tAZ diagram. 1.64... DC motor, 2.3... Switching transistor, 6... Armature current detection resistor, 7.13.57... OP amplifier, 8.9.10
．． 11.14.23.24...Resistance, 12.21.
62... Absolute value circuit, 15... Diode, 16...
...Schmitt, trigger circuit, ]7...Nand circuit, 18.34.35.43.44.48.70.71
．． 74.75.7B...AND circuit, 19.33.
63.161.162...Comparison circuit, 2(), 36
．． 37.42.46.47.56.69.72.73.
76.77... Inverter times M, 22.27... Tacho generator, 25.26.28.29... Analog switch, 30... Speed command device, 31... Switch device, 32...・Shift command 'IFe position, 38...
・RS frithub circuit, 45...OR (b)
path, fi5.66.67.68...transistor,
90a, 90b... Schmidt, upper and lower slice levels of trigger circuit 16, 105... lever, 105
d...Rank gear, 106 a, 106 b, 1
06 c, 106 d...Guide roller, 107
... Gear, 151.155 ... Diode, 1
54,158...Buffer circuit. Patent Applicant 29 - tth (ru) 2nd f4 e 2f q 12 l: Jg da 2 t s26 giant 46f3 86 q f40/! 47, F, 7 correction 43 JP-A-59-32384 (9) 3rd item (Le) (6) '4'' in one so... 2nin, 3rd figure (d/) 4th item (Run C )' e ”f4f L -J

Claims (1)

[Claims] A. A DC motor driven by a DC power source; B. A first rotation speed detection device for detecting the rotation speed of the DC motor; C6 A DC motor driven by the DC motor described above. D. A second rotation speed detection device that detects the rotation speed after the transmission; E. A transmission command device that issues a command to switch the reduction ratio of the transmission. and F. a constant speed control circuit that rotates the DC motor at a rotation speed corresponding to the output of the second rotation speed detection device by changing the output state of the speed change command device; By changing the output state of the device, the rotation speed of the power device that drives the switching mechanism of the transmission and the DC motor described above becomes the rotation speed approximately corresponding to the output of the second rotation speed detection device. (1) a stop device that stops driving the power unit when the switching of the transmission is completed; Automatic transmission O