JPS6335560B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for automatically operating a forklift truck with an automatic cargo handling mechanism.

Fig. 1 shows a forklift truck, where 1 is the truck body, 2 is a mast section consisting of an outer mast 2a and an inner mast 2b supported vertically movably thereon, and the outer mast 2a is the front part of the truck body 1. The lower part is swingably mounted. Reference numeral 3 denotes a tail cylinder attached to the truck body 1, and its piston 3a is connected to the outer mast 2a.The operation of the tail cylinder 3 adjusts the inclination angle of the mast portion 2 in the front-rear direction. A lift cylinder 4 is attached to the outer mast 2a, and its piston 4a is connected to the inner mast 2b. Reference numeral 5 denotes a chain foil rotatably attached to the upper end of the piston 4a, the middle part of the chain 6 is engaged with the chain foil 5, one end of the chain 6 is attached to the outer mast 2a or the lift cylinder 4, and the chain 6 is attached to the outer mast 2a or the lift cylinder 4. The other end is attached to an elevating member fitted to the inner mast 2b so as to be able to rise and fall freely, or to a fork 7 moored to the elevating member. Therefore, when the lift cylinder 4 is operated, the inner mast 2b rises, and
The fork 7 is guided by the inner mast 2b and lifted by the chain 6 engaged with the chain foil 5, and the cargo loaded on the fork 7 is lifted up. Further, in FIG. 2, reference numeral 8 denotes a lift height sensor, which consists of a slit plate 8a coaxially attached to the chain wheel 5 and a detection part 8b having a light emitting part and a light receiving part. The slit of the slit plate 8a is the detection part 8.
The number of pulses passing through b is detected by the number of pulses generated by the light receiving section of the detection section 8b, and based on this, the lift height distance is detected.

An object of the present invention is to provide an automatic operation method for a forklift truck with an automatic cargo handling mechanism that can perform automatic lifting operation of a forklift truck having the above configuration using a microcomputer, and can perform this automatic lifting operation safely. shall be.

Embodiments of the present invention will be described below with reference to the drawings.
FIG. 3 shows the configuration of an automatic cargo handling mechanism using a microcomputer, in which 9 is a storage section 9a, and an arithmetic processing section 9.
b and an input/output section 9c; 10 is a keyboard provided in the driver's cab 1a; by key operation of the keyboard 10, the storage section 9a is
Specify the address and memorize the lift height. Reference numeral 11 denotes a pressure switch that detects the oil pressure of the lift cylinder 4. When cargo is loaded (loaded), the oil pressure of the lift cylinder 4 increases, so the pressure switch 11 is turned on and output "1" is input to the microcomputer 9, and when there is no load, the pressure switch 11 is turned on. It is turned off and the output "0" is input to the microcomputer 9. In addition, the pulse output of the lift height sensor 8 is also input to the microcomputer 9, and the microcomputer 9 counts this pulse input with a counter provided in the input/output section 9c and processes it in the arithmetic processing section 9b to calculate the lift distance. Calculate,
The lift height is displayed on the keyboard 10. Reference numeral 12 denotes a mast position detector provided in the driver's cab 1a. The mast position detector 12 works in conjunction with the tail cylinder 3 to detect the inclination angle of the mast portion 2, and inputs its output to the microcomputer 9. Further, the claw portion 7a of the fork 7 must be kept horizontal, and for this purpose, the mast portion 2 must be tilted appropriately depending on whether it is loaded or unloaded, and the microcomputer 9 stores this tilt angle in advance. ing. 13 is a pump that applies hydraulic pressure to the tail cylinder 3 and lift cylinder 4 via hydraulic valves 14 and 15, respectively, and 16 and 17 are servo motors that drive the hydraulic valves 14 and 15, respectively.

In the automatic cargo handling mechanism described above, when the operator calls up a certain address where the lifting height is stored by operating the keyboard 10 and presses the automatic lifting height start button, the microcomputer 9 causes the pressure switch 1 to be pressed.
1. Lifting height sensor 8 and mast position detector 12 Furthermore, each servo motor 1 is controlled so as to obtain a pre-stored control value while obtaining information from a pressure switch 11.
The hydraulic valves 14 and 15 are driven through the cylinders 6 and 17, thereby operating the cylinders 3 and 4 to perform automatic lifting operation.

However, when calling an address, if the operator mistakenly calls an address for which the lifting height is not memorized,
Since this unmemorized address also contains a random value, when the automatic lift start button is pressed, the fork 7 will move toward the false value, which is extremely dangerous.

By the way, in this embodiment, when storing the lifting height at a certain address, the lifting height is stored in an empty bit other than the bit used for storing the lifting height, as shown in FIG. Enter the value to display the height, and when performing automatic lift operation, check whether the address called has a value that indicates that this lift height has been memorized, and then press the automatic lift start button. Make it.

Figure 5 is a flowchart for programmatically controlling such a procedure.When an address is specified, it is checked to see if there is a value indicating that the lift height has been memorized at that address, and this value is If not, output a warning and return to the main loop. Also, if this value exists, the contents are extracted, automatic lifting operation is performed, and the process is returned to the main loop. Therefore, if there is no value in this memorized display, automatic lifting operation cannot be performed even if the automatic lifting height start button is pressed, and a warning signal indicates that no lifting height is stored at that address. Can be detected immediately.

In the above embodiment, the value of the memory display is entered into the empty bit of the address where the lift height is stored, but the value of the memory display may be entered into the empty bit of an address related to the address. . In this case, during automatic lifting operation, it is checked whether or not there is a numerical value stored and displayed at this related address.

As described above, in the present invention, in a forklift truck with an automatic cargo handling mechanism in which automatic lifting operation is performed by a microcomputer, when a lifting height is stored at an address in the memory section of the microcomputer, the address or A value indicating that the lifting height has been memorized is entered into the empty bit of an address related to the address, and when automatic lifting operation is performed, the memory display is placed at the called address or an address related to this address. Automatic lifting height operation is started after confirming that the value is present, and if the operator accidentally calls an address for which the lifting height is not memorized during automatic lifting height operation, the address or The operator can immediately detect an error because there is no numerical value for the lift height memory display at the address related to the address. Therefore, the automatic lifting operation of the fork is not carried out haphazardly in accordance with a random value entered in an address whose lifting height is not stored, and the automatic lifting operation can be performed safely.

[Brief explanation of the drawing]

Fig. 1 is a front view of the forklift truck, Fig. 2 is a front view of the lifting height sensor, Fig. 3 is a configuration diagram of the automatic cargo handling mechanism, and Fig. 4 is the address of the address storing the lifting height according to the present invention. An explanatory diagram of how to enter a numerical value in the memory display using empty bits, and Fig. 5 is a flowchart for program control to perform automatic lifting operation after checking whether there is a numerical value in the memory display. 3... Tail cylinder, 4... Lift cylinder, 7... Fork, 8... Lift height sensor, 9...
Microcomputer, 10...Keyboard, 1
1... Pressure switch, 12... Lift position detector, 14, 15... Hydraulic valve, 16, 17...
Servomotor.

Claims (1)

[Claims] 1. In a forklift truck with an automatic cargo handling mechanism in which automatic lifting operation is performed by a microcomputer, when storing the lifting height at an address in the memory section of the microcomputer, the address or an address related to the address Input a value indicating that the lift height has been stored into the empty bit of , and when the automatic lift operation is performed, it will be indicated that the lift height has been stored at the called address or an address related to this address. An automatic operation method for a forklift truck with an automatic cargo handling mechanism, characterized in that automatic lifting operation is started after confirming that there is a numerical value to be displayed.