JPH08336209A - Controller for motor vehicle - Google Patents

Abstract

PURPOSE: To simplify the circuitry by increasing the current limit value again when the stepping angle of accelerator is sustained higher than a predetermined value for a predetermined time and returning the current limit value back to an original value upon elapse of a predetermined time thereby eliminating a bypass contactor and an intricate timing control. CONSTITUTION: A potentiometer 4 or a limit switch for detecting the stepping angle of an accelerator pedal 3 is connected with a control circuit 6 in order to transmit a detection signal. The control circuit 6 makes a decision whether the stepping angle of accelerator in a motor vehicle is higher than a predetermined value or the a limit switch functions or not and controls the current limit value to increase when the stepping angle is higher than the predetermined value or the limit switch is functioning. When the control for increasing the current limit value sustains for a predetermined time, the control is stopped. This constitution eliminates the bypass contactor and intricate timing control and simplifies the circuitry.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control device for an electric vehicle which contributes to downsizing of a unit.

[0002]

2. Description of the Related Art In a conventional control circuit, a bypass contactor is connected in parallel with a switching element, and the bypass contactor operates when full accelerator is applied.

[0003]

As is conventional, a bypass contactor is connected in parallel with the switching element,
In the configuration in which the bypass contactor operates during full accelerator operation, the contact is rough due to the arc when opening and closing the bypass contactor.

In order to prevent the contactor contact from becoming rough, the timing of the pulse applied to the switching element of the chopper becomes important when opening and closing the contactor contact, and this timing control was difficult.

[0005]

SUMMARY OF THE INVENTION According to the present invention, in an electric vehicle in which traveling is controlled by a chopper device composed of a switching element, the current limiting value is increased again when the accelerator depression angle of the electric vehicle has passed a certain time. In order to solve the above-mentioned problems, a control circuit for transmitting an output signal for returning to the original current limiting value after a fixed time is transmitted to the switching element.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to the drawings, an embodiment of the present invention will be described with reference to FIG.
1 is a side view of a forklift truck equipped with the present control device. 1 is a vehicle body of the forklift truck, and an accelerator pedal 3 is tiltably provided on a footsheet 2 of the vehicle body 1. The pedal 3 is provided with a potentiometer 4 or a limit switch 5 for detecting the depression angle of the accelerator pedal 3.
The controller 4 or the limit switch 5 is connected to the control circuit 6 to transmit a detection signal.

As shown in FIG. 2, the control circuit 6 has an I / O port 61 to which a detection signal from the potentiometer 4 or the limit switch 5 is applied, and a constant depression angle of an accelerator of an electric vehicle. When the time has elapsed, the current limiting value is raised again and after a certain period of time, the output signal for returning to the original current limiting value is transmitted to the switching element. The ROM 62 for storing the set value of the time and the I / O port. 61, an MPU 63 for performing an arithmetic operation with an input from the ROM 62 and controlling a predetermined current limit value increase.

In the main circuit, as shown in FIG. 3, a motor 8 and a chopper device 9 are connected to a power source 7 in series.

Referring to the flow chart of the present invention in FIG. 4 and the waveform diagram in FIG. 5, it is determined whether or not the depression angle of the accelerator of the electric vehicle is a certain value or more or the limit switch is activated (step S1). When the accelerator pedal depression angle of the electric vehicle is equal to or greater than a certain value or when the limit switch is operating, for example, 3 seconds, a command signal is output to control the current limit value increase, or 3 seconds elapse. If not, repeats until 3 seconds have passed (step S2). When the control for increasing the current limit value has elapsed for 5 seconds, a command signal is output to stop the control for increasing the current limit value, or if 5 seconds has not elapsed, repeats until 5 seconds have elapsed ( Step S3).

[0010]

As described above, according to the present invention, when the accelerator depression angle of the electric vehicle elapses for a certain time, the current limiting value is increased again, and after a certain time, the output signal for returning to the original current limiting value is switched. With the configuration in which the control circuit for transmitting to the element is provided, it is possible to eliminate the bypass contactor and perform complicated timing control, and it is possible to simplify the circuit.

[Brief description of drawings]

FIG. 1 is a side view when the present invention is mounted on a forklift.

FIG. 2 is a control circuit diagram of the present invention.

FIG. 3 is a main circuit diagram of the present invention.

FIG. 4 is a flow chart of the present invention.

FIG. 5 is a waveform diagram of the present invention.

[Explanation of symbols]

 1 vehicle body 2 foot sheet 3 accelerator pedal 4 potentiometer 5 limit switch 6 control circuit 7 power supply 8 motor 9 chopper device 10 chopper drive control device

 ─────────────────────────────────────────────────── ─── Continued front page (72) Inventor Shinya Katsura 2-1-1, Higashijinzou, Nagaokakyo-shi, Kyoto Within Nippon Transport Co., Ltd. (72) Hideki Hase 2-1-1, Higashishinzoku, Nagaokakyo-shi, Kyoto No. 1 Japan Transport Co., Ltd.

Claims (1)

[Claims] 1. In an electric vehicle in which traveling is controlled by a chopper device composed of a switching element, the current limiting value is increased again when the accelerator depression angle of the electric vehicle has passed a certain time, and after a certain time, the original current limiting is performed. A control device for an electric vehicle comprising a control circuit for transmitting an output signal for returning to a value to the switching element.