JPS6192933A - Vehicle speed control device of battery fork lift - Google Patents

Abstract

PURPOSE:To improve safety of a vehicle body without operating an accelerator, etc., and thereby prevent the vehicle body from jumping and being inverted by automatically controlling the vehicle to a vehicle speed in response to the time of changing an operating wheel when the wheel is quickly changed and turned. CONSTITUTION:Outputs from respective left and right switches 9, 10 operated by a cam 8 integral with an operating wheel 3 are sent to a detector 24, whereby the time t required for the switch 9 or 10 being changed from off to on state (time of changing) is detected, and compared with set time T of a setting unit 2 in a comparison operating circuit 25. When t<T, a signal in response to said time is sent to a second circuit 23 of a controller 21. A smaller signal between an output signal from the second circuit 23 and an output signal from the first circuit 22 controlled in response to operation of an accelerator 7 is sent to a chopper 20 for controlling a travelling motor 5.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a device for controlling the vehicle speed of a battery forklift truck.

Conventional technology A battery and an electric motor are connected through a chopper controlled by an accelerator, and current is sent to the electric motor according to the operating stroke of the accelerator to control the rotational speed of the electric motor, thereby driving the electric motor. A vehicle speed control device that controls the rotational speed of a driving wheel to adjust the traveling speed, that is, the vehicle speed, to a value that corresponds to the operating stroke of the accelerator.

Problem to be Solved by the Invention Since the vehicle speed depends on the operating stroke of the accelerator, □ For example, when driving indoors such as in a warehouse, when turning left, it suddenly switches back to right. If you do not reduce the vehicle speed by operating the , a large centrifugal force will suddenly act on the vehicle body, causing the vehicle to lose stability and cause the vehicle to jump or fall, which is dangerous.

To prevent this, it is possible to reduce the vehicle speed by operating the accelerator, but operating the steering wheel and accelerator at the same time is extremely troublesome and requires skill, and since the vehicle speed of a battery forklift is generally slow, it is difficult to Since the driver does not have the will to reduce the vehicle speed, it is virtually impossible to decelerate by operating the accelerator during a sudden turn.

In order to solve the problem, a means for detecting the switching time of the operating steering wheel, and a controller that sends a signal to the chopper in accordance with the switching time are provided, and the vehicle speed is automatically adjusted when the vehicle suddenly turns and turns. This is something that can be slowed down.

Embodiment FIG. 3 is an overall front view, and a driving wheel 2 and a steering wheel 3 are mounted on the front and rear of a vehicle body 1, and the driving wheel 2 is driven by an electric motor 5 supplied with current from a battery 4. At the same time, the steering wheels 3 are controlled to be steered left and right by the handle 6, and the current supplied to the electric motor 5 is controlled by the operating stroke of the axle self.

As shown in FIG. 4, left and right switches 9 and 10 are connected to the vehicle body 1 facing the cam 8 that swings together with the steering wheel 3.
When the steering wheels 3 turn to the left, the left switch 9 is turned on, when the steering wheels 3 turn to the right, the right switch 10 is turned on, and when the steering wheels 3 are straight, the left and right switches 9 and 10 are turned off.

FIG. 1 is a vehicle speed control circuit diagram, in which the battery 4 and the electric motor 5 are connected via a chopper 20, the chopper 20 is controlled by a signal from a controller 21, and the controller 21 is controlled by the operating stroke of the accelerator. A first circuit 22 that outputs a signal in accordance with the output of a comparison calculation circuit to be described later, and a second circuit 23 that outputs a signal in accordance with the output of a comparison calculation circuit described later. A signal is sent from the controller 21 to the chopper 20 to control the current supplied to the electric motor 5.

The ON and OFF signals of the left and right switches 9 and 10 are sent to the detector 24, and after the left or right switch 9 or 10 is turned OFF, the right or left switch 10 or 9 is turned ON.
Detects the time t until turning left or right, that is, the time t when turning from turning to right or left turning, and the time t is sent to a comparison calculation circuit 25 and compared with the set time T of the setting device 26, t(T), a time-dependent signal is sent to the second circuit 23.

Here, the set time T is the longest time for a sudden changeover, and is determined by calculation or actual measurement taking into account the stability of the vehicle body.

Because of this, when the switching time t is smaller than the set time T, a signal corresponding to that time is sent from the comparison calculation circuit 25 to the second circuit 23 of the controller 21.
A control signal is sent to the chopper 20 to control the current supplied to the electric motor 5 to reduce the vehicle speed as shown in FIG. 2 even if the operating stroke of the accelerator is large, thereby improving the stability of the vehicle body.

Note that when the time t becomes larger than the predetermined value T, the vehicle body stability can be maintained without reducing the vehicle speed, so the predetermined value 1
'When you are stuck, try not to reduce the vehicle speed.

Effects of the Invention When a sudden turn is made, the speed of the vehicle can be set according to the time required for the turn, so the stability of the vehicle can be improved without the need to operate the accelerator, thereby preventing the vehicle from jumping up or falling over.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, in which Fig. 1 is a vehicle speed control circuit diagram, Fig. 2 is a table showing the relationship between vehicle speed and time, Fig. 3 is an overall front view of a battery forklift, and Fig. 4 is a steering diagram. FIG. 3 is a plan view of a ring and left and right switches. 1 is the vehicle body, 2 is the drive wheel, 3 is the steering wheel, 4 is the battery, 5
is an electric motor, 20 is a chopper, and 21 is a controller.

Claims (1)

[Claims] The electric motor 5 that drives the driving wheels 2 is connected to the battery 4 via the chopper 20, and the chopper 2
1. A vehicle speed control device for a battery forklift truck, characterized in that a controller 21 sends a signal to a vehicle speed control device for a battery forklift.