JPH0676187B2 - Crane simultaneous hoisting speed control method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Industrial Field of the Invention The present invention is for lifting and lowering a long object such as a vehicle while keeping the hook level of both clubs in a horizontal state at the same time. The present invention relates to a method for controlling the uniform assembling speed of a crane.

○ Conventional technology As a method for controlling the crane co-suspending speed, the hook level of both clubs is detected and the resistance value of the secondary resistor of the wire wound motor is increased / decreased to adjust the speed to zero. A method of controlling so as is known is known.

○ Problems of the conventional technology In the above-mentioned conventional technology, there is a delay in speed correction due to large speed fluctuation due to unbalance of suspension load and long response time, and the synchronous operation of the hooks of both clubs is insufficient. There were problems such as.

In view of the above problems, the present invention provides a crane co-suspending uniform speed control method capable of quickly and reliably maintaining the hooks of both clubs horizontally and easily controlling the level of the club hooks. To aim.

[Means for Solving the Problems] In order to achieve the above object, the present invention provides a car for driving the hoisting drums of both clubs in a crane co-suspending uniform velocity control method for co-suspending work with two clubs. The level difference between the hooks of both clubs is detected by the synchro transmitter and the differential receiver installed on the rotating shafts of the hoisting drums of both clubs, while controlling the induction motor with an inverter at the same frequency. When a difference occurs, the gist is to increase or decrease only the frequency of the inverter control for one of the squirrel cage induction motors to make the levels of both clubs equal.

Examples Examples will be described below based on examples shown in the drawings.

In carrying out the hanging work of a long object A such as a vehicle with two clubs, the first club hoisting drum 1 is driven by the first electric motor M1 of the squirrel cage induction motor, and the second club hoisting drum 2 is also the squirrel cage. Driven by the second motor M2 of the induction motor,
The first inverter control device 3 and the second inverter control device 4 control the inverters 1 and M2, respectively, and the hoisting speed of both clubs (hook lifting speed) by changing the command frequency for both inverter control devices 3 and 4. Can be changed freely. In this case, the squirrel cage induction motors M1 and M2 that drive the hoisting drums 1 and 2 of both clubs are connected to the inverter control devices 3 and 4, respectively.
While controlling the inverters at the same frequency, the level difference between the hooks of both clubs is controlled by the first synchro oscillator 5 and the second synchro oscillator 5 provided on the rotating shafts of the hoisting drums 1 and 2 of the clubs.
The synchro oscillator 6 and the synchro oscillator and the differential receiver 7 detect the difference between the rotation axes of the hoisting drums 1 and 2.

Then, by comparing the levels of both hooks, the frequency of inverter control for one of the first electric motor M1 or the second electric motor M2, that is, only the command frequency is increased or decreased, and the level is advanced in comparison with the other hook. If so, the command frequency for the electric motor is lowered, and if the level is delayed compared to the other hook, the command frequency is raised, and the hook levels of both clubs are maintained horizontally.

Specifically, when the hook level of the first club is advanced, the command frequency for the first electric motor M1 is lowered to reduce the lifting speed of the hook of the first club.

Also, when the hook level of the first club is delayed,
The command frequency for the first electric motor M1 is increased to increase the lifting speed of the hooks of the first club.

Thus, in the co-suspended crane work by both clubs, the level of the hooks of both clubs is made equal and the long object A such as a vehicle is kept horizontal.

EFFECTS OF THE INVENTION According to the present invention, since the squirrel-cage induction motor is used as the electric motor for driving the hoisting drum of the club, and the squirrel-cage induction motor is controlled by the inverter, the hooks of both clubs can be quickly moved by a simple device. In addition, the cage-type induction motor that drives the hoisting drum of the club is always controlled by the inverter at a specified frequency, so that the club hook The level can be controlled very easily.

[Brief description of drawings]

FIG. 1 is a schematic view showing an example of an apparatus for carrying out the crane simultaneous hoisting speed control method of the present invention. 1 ... 1st club hoisting drum 2 ... 2nd club hoisting drum 3 ... 1st inverter control device 4 ... 2nd inverter control device 5 ... 1st synchro oscillator 6 ... 2nd synchro oscillator 7 ... Differential receiver M1 ... First motor M2 ... Second motor

Claims (1)

[Claims] 1. A crane co-suspend uniform speed control method for co-suspending work between two clubs, wherein a squirrel cage induction motor for driving a hoisting drum of both clubs is controlled by an inverter at the same frequency. If the level difference between the hooks of both clubs is detected by detecting the level difference by the synchro transmitter and the differential receiver installed on the hoisting drum rotary shafts of both clubs, one of the cage-type induction motors A method for controlling the uniform speed of co-suspending cranes, characterized in that the levels of both clubs are made equal by increasing or decreasing only the frequency of inverter control for the squirrel cage induction motor.