JPS5850081B2 - electric car control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a control device for a running motor in an electric vehicle, which is equipped with at least two running motors to drive both left and right wheels of the vehicle.

Conventionally, electric vehicles, especially industrial vehicles such as battery forklifts, are used mainly for the purpose of reducing the turning radius of the vehicle.
There was a system in which both the left and right wheels were driven by two running motors, and when the vehicle was turning, the drive power of one of the running motors on the inner wheel was cut off, and power was supplied only to the running morph on the outer wheel. .

However, with the rationalization of logistics in recent years, smooth turning with light steering force is now required.

In view of the above points, the present invention applies a lower voltage to the inner wheel drive motor than the outer wheel drive motor when the vehicle turns, thereby smoothly rotating the vehicle with a small turning radius and with a light steering force. It is an object of the present invention to provide an electric vehicle control device that can be turned, has a simple circuit configuration, and is particularly suitable for industrial vehicles such as battery forklifts.

An embodiment of the present invention shown in the drawings will be described below.

In Fig. 1, 1 is a DC power source, 2 and 3 are running motors attached to the left and right drive wheels at the front of the vehicle, and 4.5 is a right motor whose conduction time is variable depending on the steering angle of the steering wheel. The right and left side switches are the left side semiconductor switching elements, 6 is the main side switch which is the main semiconductor switching element, 7 is its commutation circuit, and 8 and 9 are flywheel diodes of the driving motor 2.3, respectively.

The commutation circuit 7 includes a commutation capacitor 7a, a commutation reactor 7b, an auxiliary thyristor 7c, and a commutation thyristor 7.
Consists of e.

Reference numeral 10 denotes a known on-pulse oscillator which generates on-pulses as shown in FIG. 2A at a predetermined period. This on-pulse is applied to the main thyristor 6 and the auxiliary thyristor 7c, thereby making both the thyristors 6.7c conductive.

Reference numeral 11 denotes a known off-pulse oscillator that generates off-pulses in synchronization with on-pulses as shown in FIG. This off-pulse is applied to the commutating thyristor 7e, making it conductive, and this off-pulse is applied to the commutating thyristor 7e, making it conductive.
The main cyrisk 6 is cut off by conduction of e.

Note that since the commutation circuit 7 is well known, detailed explanation of its operation will be omitted.

Reference numeral 13 denotes right turn conduction control means for delaying the on-pulse, and is composed of a known delay circuit, so that when the steering wheel is turned to the right, the delay time becomes longer as the turning angle to the right increases. 2B, which is controlled by a potentiometer and is applied to the right hand side risk 4 to cause it to conduct.

Note that this delayed pulse generates the same pulse as the on-pulse as shown in FIG. 2A, which is not delayed at all when the steering wheel is not turned to the left or right or when it is turned to the left.

Reference numeral 14 denotes a left turn conduction control means for delaying the on-pulse, and is composed of a known delay circuit, so that when the steering wheel is turned to the left, the delay time becomes longer as the turning angle to the left increases. Controlled by a power meter, a delay pulse, shown in FIG. 2B, is generated, which is applied to the left thyristor 5, causing it to conduct.

Note that this delayed pulse generates the same pulse as the on-pulse as shown in FIG. 2A, which is not delayed at all when the steering wheel is not turned to the left or right or when it is turned to the right.

Further, the above-mentioned steering handle changes the direction of the wheels provided at the center of the rear of the vehicle.

Next, the operation of the above configuration will be explained.

When the vehicle travels straight, both the right and left thyristors 4.5 and the main thyristor 6 are supplied with a trigger signal as shown in FIG. 2A and are rendered conductive.

Therefore, the right and left thyristors 4, 5 are turned on and off simultaneously with the main thyristor 6.

This main thyristor 6 constitutes a chopper circuit with the commutation circuit 7, and its conduction waveform is as shown in the second figure, and its conduction ratio follows the amount of depression of the accelerator pedal 12, so the vehicle It is possible to obtain a vehicle speed corresponding to the amount of depression of the pedal.

Next, when the steering wheel is turned to make a turn of the vehicle, the right or left thyristor 4 or 5 connected to the motor 2 or 3 for running the inner wheel of the turn becomes conductive for a period of time depending on the turning angle of the steering wheel. The control means 13 or 14 supplies a trigger pulse later than the trigger pulse of the main thyristor 6, as shown in FIG. 2B, and conducts.

When the main thyristor 6 is cut off by the commutation circuit 7, the right and left thyristors 4 and 5 have no path for the load current to flow, and the main thyristor 6 is cut off at the same time.

With this, 1. The conduction waveform of one of the right and left side risks 4°5 is as shown in Figure 2E, and this side risk controls the running morph on the inner ring side, and the conduction waveform of the other side risk and the main side risk 6 is as shown in Figure 2E. As shown in the figure, the driving morph on the outer wheel side is controlled by this sirisk.

Therefore, the voltage applied to the inner wheel driving morph is lower than that of the outer wheel driving motor by an amount corresponding to the steering angle, so the vehicle can turn smoothly to the right and left with a light steering wheel operating force. .

FIG. 3 shows the main part of another embodiment of the present invention.
, 16 are electromagnetic contactors that operate in response to a full speed command from the accelerator pedal.

In this embodiment, when the accelerator pedal is depressed to full speed, the electromagnetic contactors 15 and 16 are activated to short-circuit the right and left thyristors 4 and 5 and the main thyristor 6, respectively, and to connect the respective drive motors 2 and 3. Since the thyristors 4, 5, and 6 are directly connected to the DC power supply 1, there is no forward voltage drop in each thyristor 4, 5, 6, and efficient operation can be achieved.

In both of the embodiments described above, when the vehicle turns, the drive motors on the inner and outer wheels are operated at different voltages depending on the steering angle.
If the armature or field connection is switched so that when the steering angle increases to a predetermined value, the inner wheel running morph generates a driving force in the opposite direction to the traveling direction, the vehicle will have an even smaller turning radius. You can turn with.

Furthermore, in the embodiment described above, two right and left turning conduction control means 13.14 each consisting of two delay circuits are used, and the delay time of the pulse generated in each turning conduction control means 13.14 is Although it was designed to vary according to the steering angle, a delay circuit delays the on-pulse for a predetermined period of time regardless of the steering angle, and when the steering angle is below a predetermined value, the on-pulse is applied directly to the cloth and the right thyristor 4.5. When the steering wheel is turned to the right by a predetermined angle or more, the output pulse of the delay circuit is applied to the right thyristor 4, and when the steering wheel is turned to the left by a predetermined angle or more, the output pulse of the delay circuit is applied to the left thyristor 4. 5
The turning conduction control means may be constituted by a gate circuit or the like which is switched and connected so as to apply an electric current to the electric motor.

Further, in the above-described embodiments, Cyrisk was used as the main semiconductor switching element and the right and left semiconductor switching elements, but other semiconductor switching elements such as transistors may be used depending on the case.

As described above, the device of the present invention includes a main semiconductor switching element and right and left semiconductor switching elements connected in series to each traveling motor, and when the vehicle turns, the cloth and the left semiconductor switching element are connected to each other in series. Since the conduction timing on the inner wheel side is delayed, with a simple configuration, the inner and outer wheel drive motors can be driven at different voltages when the vehicle turns, and this allows smooth turning with light steering force. It has the excellent effect of being able to

[Brief explanation of drawings]

Fig. 1 is an electrical wiring diagram showing one embodiment of the device of the present invention;
The figures are waveform diagrams of various parts for explaining the operation of the device of the present invention shown in FIG. 1, and FIG. 3 is an electrical wiring diagram of main parts showing another embodiment of the device of the present invention. 2.3...Travel motor, 4,5...
Right and left side risks forming right and left semiconductor switching elements, 6 Main side risks forming main semiconductor switching elements, 13.14 Right and left turning conduction control means.

Claims (1)

[Claims] 1. In an electric vehicle in which the left and right wheels of the vehicle are independently driven by each traveling motor, a main semiconductor switching element for simultaneously controlling the speed of each traveling motor by simultaneously turning on and off power to each traveling motor. , a left semiconductor switching element connected in series to the travel motor on the left wheel side of the vehicle, and a right semiconductor switching element connected in series to the travel motor on the right wheel side of the vehicle; 1. An electric vehicle control device comprising: turning conduction control means for delaying the conduction timing of one of the right semiconductor switching elements corresponding to the inner ring side relative to the main semiconductor switching element.