JPH08282995A - Cargo handling control device for forklift truck - Google Patents

Abstract

PURPOSE: To judge whether a lift height is maximum or not so that operation can be performed by anybody, by providing a lift height detector and a load detector, comparing a maximum lift height set signal in a memory device with a lift height detection signal detected at present, and outputting an alarm signal when the lift height detection signal exceeds the maximum lift height set signal. CONSTITUTION: A load detector 12 is arranged in a lift cylinder, and a lift height detector 11 is arranged in a mast, to form a control device of a one-chip microcomputer 21, proportional solenoid control valve exciting coil drive circuit 23 and a hydraulic use motor drive circuit 24. The one chip microcomputer 21 inputs a weight signal of cargo loaded at present and a lift height signal at present, and a difference between a maximum limit lift height corresponding to weight of the cargo stored in a memory and the present lift height signal is calculated, to operate an alarm circuit 19 or to interrupt a current, flowing in an excitation coil of a proportional solenoid control valve, by the proportional solenoid control valve exciting coil drive circuit 23. In this way, operation can be performed even by an unskilled driver, to eliminate complication of eye estimation and erroneous operation.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a forklift truck cargo handling control device which enables a driver to immediately determine the maximum lifting height without visual inspection and to improve the efficiency of cargo handling work.

[0002]

2. Description of the Related Art Conventionally, there has never been a device equipped with a device in which the maximum lift, which fluctuates due to changes in load and changes in lift, is immediately known to the driver.

[0003]

There is no device as described above, and it is often the driver's intuition whether or not the maximum lift is reached.
For this intuition to work, you must be a person who is familiar with driving skills. That is, there was a problem that no one could drive easily.

[0004]

SUMMARY OF THE INVENTION The present invention is a forklift truck which is equipped with a proportional solenoid control valve and which controls a cargo handling work device by operating a cargo handling operation lever provided on a vehicle body. The forklift truck is arranged in front of the forklift truck. A lift detector for detecting the height of the fork, a load detector for detecting the weight of the load loaded on the fork, a lift detection signal and a load detection signal of the lift detector, and a storage device. The maximum lift signal set inside is called, the maximum lift setting signal is compared with the currently detected lift detection signal, and the alarm circuit is activated when the lift detection signal exceeds the maximum lift setting signal. The present invention has been devised to solve the above problems as a configuration including a control device that outputs a drive signal.

The other one is a forklift truck which is equipped with a proportional solenoid control valve and controls a cargo handling work device by operating a cargo handling operation lever provided on a vehicle body. In the forklift truck, the height of a fork arranged in front of the forklift truck is controlled. The lift detector for detecting the load, the load detector for detecting the weight of the load loaded on the fork, the lift detection signal and the load detection signal of the lift detector are input and set in the storage device. The maximum lift signal is called, the maximum lift setting signal is compared with the currently detected lift detection signal, and when the lift detection signal exceeds the maximum lift setting signal, the exciting coil of the proportional solenoid control valve is It may be configured to include a control device that outputs a signal that interrupts the flowing current.

The other two are lift lift trucks for controlling the cargo handling work device by operating a lever of a manual switching valve arranged on a vehicle body, and for detecting the height of a fork lift truck arranged in front of the forklift truck. A detector and a load detector that detects the weight of the luggage loaded on the forks,
The lift detection signal and the load detection signal of the lift detector are input, and the maximum lift signal corresponding to the weight of the load set in the storage device is called to detect the maximum lift setting signal and the current detection. It is also possible to provide a control device which compares the lift detection signals and outputs a drive signal for operating the alarm circuit when the lift detection signal exceeds the maximum lift setting signal.

The other three are lift lifts for detecting the height of a fork arranged in front of the forklift truck in a forklift truck for controlling a cargo handling work device by operating a lever of a manual switching valve arranged on a vehicle body. A detector and a load detector that detects the weight of the luggage loaded on the forks,
The lift detection signal and the load detection signal of the lift detector are input, and the maximum lift signal set in the storage device according to the weight of the package is called to detect the maximum lift setting signal and the current detection. It is also possible to provide a control device that compares the lift detection signals and outputs a stop signal for stopping the drive of the hydraulic motor when the lift detection signal exceeds the maximum lift setting signal.

[0008]

1 is a side view showing a counterbalance type embodying the present invention. A counterbalance type forklift 1 includes a vehicle body 2, steering wheels 3 in front of the vehicle body 2, and drive wheels 4 in the rear. A mast 5 is erected in front of the steered wheels 3, and a front hood 6 is formed in front of the vehicle body 2 and behind the mast 5, and a cargo handling operation lever 7 is provided on the upper surface of the front hood 6. A fork 9 is vertically movable via a lift bracket 10 in front of the mast 5.

The mast 5 is composed of an outer mast 5A and an inner mast 5B, and a lift cylinder 8 is arranged behind the outer mast 5A. The lift cylinder 8 has a load detector 12 and the mast 5 has a lift detector 11. It is arranged.

As shown in FIG. 2, the lift detector 11 includes a chain wheel 1 on the inner mast 5B.
1A is rotatably supported, and the chain wheel 11A
The chain 11B is locked to, and the gear 11C meshing with the chain 11B and the input shaft 11E of the encoder 11D are connected to the input shaft 11E of the encoder 11D meshing with the chain 11B as the inner mast 5B moves up and down. The rotational force is transmitted and the number of rotations of the encoder 11D is counted to detect the amount of rise or fall of the forks 9.

As shown in FIG. 3, the load detector 12 is provided with a pressure detector 12A on the bottom side of the lift cylinder 8 and transmits a detection signal of the pressure detector 12A to a pressure transmitter 12B. The pressure transmitter 12B converts the weight signal into a weight signal.

The hydraulic circuit will be explained by taking a case of a proportional electromagnetic control valve as an example, as shown in FIG. 4. A tank 13 for storing hydraulic oil, a pump for applying pressure to the hydraulic oil in the tank 13 and pumping it out to the outside. 14 and a hydraulic motor 15 for rotationally driving the pump 14, the hydraulic oil discharged from the pump 14 is proportional to the electromagnetic control valve 16 and the conduits 17 and 18.
Is supplied to the lift cylinder 8 connected to the lift cylinder 8, and the lift cylinder 8 generates a driving force for moving the fork 9 up and down.

As shown in FIG. 5, the control device 9 includes a one-chip microcomputer 21, a proportional electromagnetic control valve exciting coil drive circuit 23 controlled by an output signal of the one-chip microcomputer 21, and a hydraulic motor drive. The one-chip microcomputer 21 is composed of a circuit 24. The one-chip microcomputer 21 receives the weight signal of the currently loaded luggage and the current lifting height signal HL, and stores the maximum limit lifting corresponding to the weight of the luggage stored in the memory. The difference between the high HP and the current lift signal HL is calculated, and the alarm circuit 19 is activated or the current flowing through the exciting coil of the proportional electromagnetic control valve is cut off by the proportional electromagnetic control valve exciting coil drive circuit 23.

The flow of driving the alarm circuit 19 is shown in FIG. 6. First, the load detector 12 reads the load W (step S1), and then the lift detector 11 reads the current lift HP (step S2). ), Further reading the maximum restricted lift HL (step S3), comparing the maximum restricted lift HL with the current lift HP (step S4), and the current lift HP exceeds the maximum restricted lift HL. If so, a signal for activating the alarm circuit 19 is issued (step S5), and if the current lift HP does not exceed the maximum restricted lift HL, the process continues as it is.

A flow of outputting a signal for cutting off the current flowing through the exciting coil of the proportional solenoid control valve is shown in FIG.
The load detector 12 reads the load W (step S1), and then the lift detector 11 reads the current lift HP (step S).
2) Further, the maximum limit lift HL is read (step S3),
The maximum limit lift HL and the current lift HP are compared (step S4), and if the current lift HP exceeds the maximum limit lift HL, the current flowing through the exciting coil of the proportional solenoid control valve. Is output (step S6), and if the current lift height HP does not exceed the maximum limit lift height HL, the current lift height HP is continued.

[0016]

As described above, according to the present invention, the weight signal of the currently loaded luggage and the current lift signal are input, and the maximum lift and the current lift signal stored in the memory are stored. It is composed of a CPU that calculates the difference between the two and operates a warning circuit or outputs a signal that cuts off the current flowing in the exciting coil of the proportional solenoid control valve. Regardless of this, since it is only necessary to operate the operation lever, it is possible to drive even without being a skilled driver, and the operability is improved without the troublesomeness of visual inspection and operation error.

[Brief description of drawings]

FIG. 1 is a side view showing a counter balance type embodying the present invention.

FIG. 2 shows a side view of a lift detector.

FIG. 3 shows a side view of the load detector.

FIG. 4 shows a hydraulic circuit diagram.

FIG. 5 shows a block diagram of a control device.

FIG. 6 shows a flow chart of the first embodiment.

FIG. 7 shows a flow chart of a second embodiment.

[Explanation of symbols]

 1 Counterbalance type forklift 2 Car body 3 Steering wheel 4 Drive wheel 5 Mast 6 Front hood 7 Cargo handling lever 8 Lift cylinder 9 Fork 10 Lift bracket 11 Lifting height detector 12 Load detector 13 Tank 14 Pump 15 Hydraulic motor 16 16 Proportional Electromagnetic control valve 20 control device

Claims (4)

[Claims] 1. A lift lift truck for detecting a height of a fork arranged in front of the forklift truck in a forklift truck equipped with a proportional solenoid control valve for controlling a cargo handling work device by operating a cargo handling operation lever provided on a vehicle body. High detector, load detector that detects the weight of the load loaded on the fork, and the lift detection signal and the load detection signal of the lift detector are input, and the weight of the load set in the storage device. The maximum lift signal according to the above is called, the maximum lift setting signal is compared with the current detected lift detection signal, and the alarm circuit is activated when the lift detection signal exceeds the maximum lift setting signal. A forklift truck cargo handling control device comprising a control device for outputting a signal. 2. A lift truck for controlling a cargo handling device by operating a cargo handling lever provided on a vehicle body, the lift truck having a proportional solenoid control valve for detecting the height of a fork arranged in front of the forklift truck. High detector, load detector that detects the weight of the load loaded on the fork, and the lift detection signal and the load detection signal of the lift detector are input, and the weight of the load set in the storage device. The maximum lift signal according to the above is called, the maximum lift setting signal is compared with the currently detected lift detection signal, and when the lift detection signal exceeds the maximum lift setting signal, the proportional solenoid control valve A cargo handling control device for a forklift truck, comprising a control device that outputs a signal that cuts off a current flowing through an exciting coil. 3. A lift detector for detecting the height of a fork arranged in front of the forklift truck in a forklift truck for controlling a cargo handling work device by operating a lever of a manual switching valve arranged on a vehicle body, The load detector that detects the weight of the load loaded on the fork and the lift detection signal and the load detection signal of the lift detector are input, and the maximum lift according to the weight of the load set in the storage device is input. A control for calling a high signal, comparing the maximum lift setting signal with the current detected lift detection signal, and outputting a drive signal for activating an alarm circuit when the lift detection signal exceeds the maximum lift setting signal. A forklift truck cargo handling control device. 4. A lift detector for detecting the height of a fork disposed in front of the forklift truck in a forklift truck for controlling a cargo handling work device by operating a lever of a manual switching valve arranged on a vehicle body, The load detector that detects the weight of the load loaded on the fork and the lift detection signal and the load detection signal of the lift detector are input, and the maximum lift according to the weight of the load set in the storage device is input. A high signal is called, the maximum lift setting signal is compared with the currently detected lift detection signal, and when the lift detection signal exceeds the maximum lift setting signal, a stop signal for stopping the drive of the hydraulic motor is sent. A forklift truck cargo handling control device having a control device for outputting.