JPH0287908A - Acceleration regulator for electric car - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an acceleration adjustment device in a travel control device for an electric vehicle such as a forklift.

[Conventional technology]

As shown in Fig. 2, a conventional acceleration adjustment device for an electric vehicle includes a battery 1 as a DC power source and a key switch 2.
The accelerator unit 4 outputs a voltage according to the opening degree of the accelerator pedal 30 connected via the It is known to have a configuration that includes an integrating circuit 6 inserted into the engine, and an acceleration adjustment volume 7 that adjusts the time constant of the integrating circuit 6 depending on the driver and work conditions. Incidentally, devices similar to this are disclosed in Japanese Utility Model Application No. 56-35805 and Japanese Patent Application Publication No. 59-17725.
There is one described in Publication No. 8.

[Problem to be solved by the invention]

However, in the conventional electric vehicle acceleration adjustment device described above, the time constant of the integrating circuit 6 is always set by the acceleration adjustment volume 7, so when changing drivers, etc. If the setting value of the acceleration adjustment volume 7 is set to a high rapid acceleration state, when the accelerator pedal 3 is depressed, the electric vehicle will suddenly accelerate against the driver's intention, causing the electric vehicle to accelerate like a forklift. Before transporting cargo, there was an unresolved problem that caused the cargo to be damaged or torn.

This invention has been made by focusing on the unresolved problem of the above-mentioned conventional example, and is designed so that when the key switch is turned on, it is in a low acceleration state regardless of the setting value of the acceleration adjustment volume. The aim is to provide an acceleration adjustment device for electric vehicles that can solve two unresolved problems.

[Means for Solving the Problem] In order to achieve the above object, the present invention provides an accelerator unit that outputs a voltage according to the opening degree of an accelerator pedal;
In an acceleration adjustment device for an electric vehicle, which includes an integration circuit that suppresses sudden changes in the output of the accelerator unit, and an acceleration adjustment volume that can change the time constant of the integration circuit, the integration circuit is activated when a key switch is operated. an acceleration reduction circuit that forcibly increases the time constant of the acceleration reduction circuit, and an acceleration reduction reset circuit that stops the operation of the acceleration reduction circuit when the resistance value of the acceleration adjustment volume becomes equal to or less than a predetermined value. It is characterized by

[Function] In this invention, when the key switch is operated, that is, when the electric vehicle is started or stopped, the time constant of the integral circuit is forcibly increased by the acceleration reduction circuit, and the electric vehicle is in a low acceleration state. 2) After that, when the driver sets the acceleration adjustment volume below a predetermined value on the low acceleration side, the acceleration reduction reset circuit stops the operation of the acceleration reduction circuit and returns to normal acceleration adjustment polyboom. The system returns to the state of acceleration adjustment according to the driver's preference and work conditions.

〔Example〕

Hereinafter, embodiments of the present invention will be described based on the drawings.

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

In the figure, reference numeral 1 denotes a battery as a DC power source, and as in the conventional example, an accelerator unit 4 is connected to the battery 1 via a key switch 2 to output a voltage according to the opening degree of the accelerator pedal 3. It is connected. This accelerator unit 4 moves the slider 4a according to the opening degree of the accelerator pedal 3.
It is composed of a variable resistor 4b whose resistance value changes as it slides, and the resistance value is set to increase as the accelerator opening degree increases.

On the other hand, a travel motor control section 5 composed of a power transistor PT is connected to the battery 1 in series with an electric motor 5a that controls the traveling of the vehicle, and the output voltage of the accelerator unit 4 is integrated into the travel motor control section 5. It is transmitted via circuit 6.

This integrating circuit 6 has a series circuit of a resistor R9 and a charging/discharging capacitor C whose one end is connected to the negative electrode side of the battery 1, and the connection point between the two is connected to the accelerator unit via a resistor R2 and a forward diode D. 4 and the base of the power transistor of the travel motor control section 5.

The other end of the resistor R of the integrating circuit 6 is connected to the positive electrode side of the battery 1 via an acceleration adjustment volume 7 and an acceleration reduction circuit 8.

The acceleration reduction circuit 8 includes a resistor R1 having a predetermined resistance value and a bypass switching transistor ST connected in parallel with the resistor R1.

Further, an acceleration adjustment value detection circuit 9 is provided to detect the acceleration adjustment value of the acceleration adjustment volume 7. This acceleration adjustment value detection circuit 9 includes voltage dividing resistors R4 and R3 inserted between the slider 7a of the acceleration adjustment volume 7 and the connection line between the integrating circuit 6 and the traveling motor control section 5; These divided voltages VB are connected to the non-inverting input side through the resistor R of the integrating circuit 6.
7 and a comparator 9a to which the voltage VC between the acceleration adjustment volume 7 and the acceleration adjustment volume 7 is inputted to the inverting input side, respectively,
From this comparator 9a, V,>V. A comparison output C8 which becomes high level is output when .

The comparison output C8 of the acceleration adjustment value detection circuit 9 is input to the acceleration reduction reset circuit 10. In this acceleration reduction reset circuit 1O, a comparison output C6 is passed through a differentiating circuit composed of a capacitor C2 and a resistor R6 to a terminal S.
7 and a resistor P through a differentiator circuit [・terminal 67
1) The constant output of this R3 type flip-flop tube 10a is input to the base of the switch notching transistor ST of the acceleration reduction circuit 8. Now, the operation of the above embodiment will be explained. Assuming that key switch 2 is now in the off state, in the state of ゛?
acceleration unit 4, integration circuit 6, acceleration adjustment volume 7
, acceleration reduction circuit 8. 1. Power is not supplied to the acceleration reduction reset circuit 10. 7. The charging voltage of the capacitor C8 of the integrating circuit 6 becomes zero. The power transistor PT of the travel motor control unit 5 is in an off state, the electric motor 5a is in a stopped state, and the electric vehicle is in a parked state.

In this state, when a driver gets on the electric vehicle and turns on the key switch 2, the capacitor C3 and the resistor R6 that constitute the differential circuit of the acceleration reduction reset circuit 10
A differential pulse is input to the reset terminal of the flip-flop 10a from the connection point of the flip-flop 10a, and the flip-flop 10a is in the reset state, and its positive output becomes a low level. The state is turned off, and the acceleration reduction circuit 8 is put into operation.

Therefore, the resistance R3 of the acceleration reduction circuit 8 and the acceleration adjustment volume 7 are connected in series with the resistance R of the integration circuit 6, so that the time constant of the integration circuit 6 becomes large. At this time, even if the acceleration adjustment polygon 1-7 is set to the acceleration side, that is, to the small resistance value side, the time constant increases by the resistance value of the resistor R3 of the acceleration reduction circuit 8.

Therefore, even if the accelerator pedal 3 is suddenly depressed in the state of 1, :8 and the accelerator opening is suddenly increased,
Since the time constant of the integrating circuit 6 is set large, a sudden increase in the charging voltage of the charging/discharging capacitor C of the integrating circuit 6 is suppressed, and the voltage between the terminals of the charging/discharging capacitor C5 gradually increases. , in response to this, the electric motor 5 is controlled by the power transistor PT of the travel motor control section 5.
The energization control of step (a) is performed slowly to prevent the electric vehicle from suddenly starting.

In this way, when the acceleration adjustment volume 7 is set to the acceleration side, in the acceleration adjustment value detection circuit 9, the divided voltage 6 input to the comparator 9a is applied between the terminals of the resistor R of the integrating circuit 6. Since the voltage is small compared to the voltage VC, the comparison output of the comparison circuit 9a maintains a low level, and accordingly, the flip-flop 10a of the acceleration reduction reset circuit 10 maintains the reset state, and the acceleration reduction circuit 8 also closes the resistor R3. maintained in the inserted operating state.

To select a desired acceleration state from this low acceleration state, the driver first moves the acceleration adjustment volume 7 to the low acceleration side, that is, to the high resistance value side. As a result, the current flowing through the resistors R4 and R5 of the acceleration adjustment value detection circuit 8 increases, and the divided voltage V becomes larger than the voltage V between the terminals of the resistor R1 of the integrating circuit 6. The comparison output output from is inverted from low level to high level. Therefore, a differential pulse is output from the differential circuit composed of the capacitor c2 and the resistor R6 of the acceleration reduction reset circuit lO,
Since this is supplied to the cent input terminal of the flip-flop 10a, the flip-flop 10a becomes set and its positive output becomes high level. Therefore, the switching transistor ST of the acceleration reduction circuit 8 is turned on, thereby bypassing the resistor R5, and the acceleration reduction circuit 8 is brought into a non-functional state, and the time constant of the integration circuit 6 is set to the adjustment value of the acceleration adjustment volume 7. The desired acceleration state can be obtained by adjusting the acceleration adjustment volume 7 after the driver adjusts the time constant accordingly.

Furthermore, when the acceleration adjustment volume 7 is set to the low acceleration side when the key switch 2 is turned on, the flip-flop 10a of the acceleration reduction reset circuit 10 temporarily enters the reset state, and the acceleration reduction circuit 8 enters the operating state. As the comparison output of the comparator 9a of the acceleration adjustment value detection circuit 9 becomes high level, the flowchart 10a immediately enters the cent state, and its affirmative output becomes high level.
The acceleration reduction circuit 8 becomes non-functional.

In the above embodiment, as the acceleration reduction circuit 8,
Although a case has been described in which the relay is configured with a parallel circuit of the resistor R3 and the switching transistor ST, the present invention is not limited thereto. may be provided, and this relay contact may be switched by a relay energized by the positive output of the flip-flop 10a of the acceleration reduction reset circuit IO.

Further, the acceleration adjustment volume 7 and the acceleration reduction circuit 8 may be connected in an inverse relationship, that is, the acceleration adjustment volume 7 and the acceleration reduction circuit 8 may be connected in this order.

Furthermore, in the embodiments so far, the key switch 2
Although the case has been described in which the charging voltage of the integrating circuit 6 is set to zero when the key switch 2 is turned on from the off state to the on state, the present invention is not limited to this. The charging voltage of the integrating circuit 6 may be set to zero when the electric motor 5a is turned off, that is, when the electric motor 5a is stopped.

〔Effect of the invention〕

As explained above, according to the present invention, when the key switch is operated, the acceleration reduction circuit is activated and the time constant of the integration circuit that integrates the output voltage of the accelerator unit is increased regardless of the adjustment value of the acceleration adjustment volume. By forcibly entering a low acceleration state and setting the acceleration adjustment volume to a predetermined value or less in this low acceleration state, the acceleration reduction reset circuit stops the acceleration reduction circuit and returns to the normal acceleration state. Therefore, it is possible to reliably prevent the electric vehicle from accelerating unintendedly when starting.

[Brief explanation of drawings]

FIG. 1 is a circuit diagram showing an embodiment of the present invention, and FIG. 2 is a circuit diagram showing a conventional example. In the figure, ■ is the battery, 2 is the key switch, 3 is the accelerator pedal, 4 is the accelerator unit, 5 is the travel motor control unit, 5a is the electric motor, 6 is the integral circuit, 7 is the acceleration adjustment volume, and 8 is the acceleration reduction circuit. , 9 is an acceleration adjustment value detection circuit, and 10 is an acceleration reduction reset circuit.

Claims (1)

[Claims] (1) An accelerator unit that outputs a voltage according to the opening degree of the accelerator pedal, an integral circuit that suppresses sudden changes in the output of the accelerator unit, and an acceleration adjustment volume that can change the time constant of the integral circuit. In the acceleration adjustment device for an electric vehicle, the acceleration reduction circuit forcibly increases the time constant of the integrating circuit when a key switch is operated, and the operation of the acceleration reduction circuit is controlled when the resistance value of the acceleration adjustment volume is equal to or less than a predetermined value. An acceleration adjustment device for an electric vehicle, characterized in that it is provided with an acceleration reduction reset circuit that stops when the acceleration decrease occurs.