KR19990009764U - Automatic lift control device of electric forklift - Google Patents

Abstract

The automatic lift control of the electric forklift automatically controls the position of the mast of the fork. This device sets the position of mast / fork to work in advance, detects the position of current mast / fork, and automatically moves the mast / fork to the desired position accurately based on the comparison of the detected current value and the set value. It is configured to move the fork. Therefore, the present invention does not need to be manually operated by the driver, which is convenient and provides the effect of improving the efficiency and stability of the work.

Description

Automatic lift control device of electric forklift

The present invention relates to an electric forklift for use in cargo transportation, and more particularly, to an automatic lift control apparatus for an electric forklift for automatically performing a lift control operation of a mast / fork.

The electric forklift truck will repeatedly load and unload the mast and fork depending on the position of the load and load the cargo to the desired position. At this time, the mast and fork should be moved to the correct position to lift the load.

1 is a block diagram showing a conventional lift control apparatus for an electric forklift, and is configured to move the position of the mast / fork 13 by manual operation by the driver of the electric forklift.

In Fig. 1, when the driver operates the lift operation lever 11, the hydraulic control valve 12, which is the driving source of the mast / fork 13, generates hydraulic pressure. The mast / fork 13 moves by the generated hydraulic pressure. Here, the lift operation lever 11 and the hydraulic control valve 12 is mechanical. Thus, the driver operates the lift operation lever 11 to lift the mast / fork 13 to the desired height.

However, the lift control device of the conventional electric forklift as described above has an inconvenience and troublesome because the lift control by the manual operation of the driver.

Accordingly, an object of the present invention is to provide an automatic lift control apparatus for an electric forklift truck that automatically moves the mast and fork to a preset lift height so as to solve the above problems.

1 is a block diagram showing a lift control apparatus for a conventional electric forklift;

2 is a block diagram showing an automatic lift control apparatus for an electric forklift according to the present invention;

3 is a flow chart for explaining the operation of the apparatus of FIG.

Explanation of symbols for main parts of the drawings

21: lift height setting button 22: lift operation button

23: central processing unit (CPU) 24: memory

25: hydraulic motor 26: mast / fork

27: sensor

The automatic lift control apparatus of the electric forklift according to the present invention for achieving the above object is, in the electric forklift, in the lift control device of the mast / fork provided to the cargo transportation, the power source for moving the mast / fork, and automatic A lift operation button for selecting lift control, a sensor for detecting the current position of the mast / fork, and a current position and a preset mast of the mast / fork detected by the sensor at that time in response to the operation of the lift operation button. And a CPU for comparing the forks to be worked and for driving the power source based on the comparison result.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

Figure 2 shows an automatic lift control device for an electric forklift according to an embodiment of the present invention. The apparatus of FIG. 2 detects the current position of the mast / fork 26 for loading a load, the hydraulic motor 25 and the mast / fork 26, which are the power sources for moving the mast / fork 26 to a predetermined position. A sensor 27 made of a potentiometer is provided. In addition, the operation of the lift height setting button 21 for setting the position of the mast / fork 26 to work, the lift operation button 22 for selecting the start of the automatic lift control, and the lift height setting button 21 is performed. And a memory 24 for storing the position value of the mast / fork 26 to work in response. In addition, a central processing unit (CPU) 23 which controls the operation of each component for setting the position value of the mast / fork 26 to be operated and the automatic lift control in response to the operation of the two buttons 21 and 22. ). The operation of the apparatus of FIG. 2 having such a configuration will be described with reference to FIG. 3.

To set the lift height, the driver of the electric forklift truck operates a lift operation lever (not shown) to move the mast / fork 26 to a position to work, and then operate the lift height setting button 21. In the initialization state of step 301, the CPU 23 checks the input of the lift height setting button 21 (step 302). When the operation of the lift height setting button 21 is recognized, the CPU 23 reads the mast / fork 26 position at that time detected by the sensor 27 (step 303). The sensor 27 is for detecting the current position of the mast / fork 26, and a potentiometer is used here. The CPU 23 stores the position value of the mast / fork 26 read from the sensor 27 in the memory 24 in response to the operation of the lift height setting button 21 (step 304), and the lift height setting operation. Do this.

Meanwhile, the driver operates the lift operation button 22 for automatic lift control. In the initialization state of step 301, the CPU 23 checks the input of the lift height setting button 21 (step 302), and performs step 305 if the operation of the lift height setting button 21 is not recognized. In step 305, the CPU 23 checks the input of the lift operation button 22, and when the operation of the lift operation button 22 is recognized, the position value of the mast / fork to be stored in the memory 24, i.e., the set value. To load (step 306). The CPU 23 reads the position value of the current mast / fork 26 detected by the sensor 27 (step 307), and compares the set value with the read current value (step 308). In step 308, the CPU 23 recognizes that the current mast / fork 26 has not yet reached the position to work if the set value is greater than the current value, and moves the mast / fork 26 up (step 309). Step 307 is performed. The upward movement of the mast / fork 26 is executed by the hydraulic motor 25 driven by the CPU 23. In step 308, if the set value is equal to the present value, the CPU 23 recognizes that the current mast / fork 26 has reached the position to work and stops the movement of the mast / fork 26 (step 310). In step 308, the CPU 23 recognizes that the current mast / fork 26 has exceeded the position to work if the set value is smaller than the current value, and moves the mast / fork 26 down (step 311). Perform 307. The lowering movement of the mast / fork 26 is also executed by the hydraulic motor 25 driven by the CPU 23. Through this step, the mast / fork 26 is automatically moved to the working position.

As described above, the automatic lift control apparatus of the electric forklift according to the present invention, as compared with the conventional lift control of the mast / fork by manual operation, automatically controls the lift with a single button operation, thus providing convenience to the driver and working. Has the effect of improving the efficiency and safety.

Claims (5)

In the electric forklift, in the lift control device of the mast / fork provided to the cargo transportation, A power source for moving the mast / fork; Lift operation buttons for selecting automatic lift control; A sensor for detecting a current position of the mast / fork; And And a CPU for comparing the current position of the mast / fork detected by the sensor with the operation position of the preset mast / fork and then driving the power source in response to the operation of the lift operation button. Automatic lift control. The method of claim 1, further comprising a lift height setting button for positioning a mast / fork to work, And the CPU sets the current position of the mast / fork detected by the sensor at that time in response to the operation of the lift height setting button to the position to be worked. The automatic lift control apparatus according to claim 1, wherein the sensor is a potentiometer. The method of claim 1, wherein the CPU compares the current position of the mast / fork with the setting position, and if the current position is lower than the setting position, driving the power source so that the mast / fork moves up until the current position becomes the setting position. Automatic lift control device characterized by. The method of claim 1, wherein the CPU compares the current position and the set position of the mast / fork, and if the current position is higher than the set position to drive the power source so that the mast / fork moves down until the current position becomes the set position Automatic lift control system.