Low-speed rotary control method and system for cranes

Abstract

The invention relates to the technical field of cranes and discloses a low-speed rotary control method for cranes. The method comprises the following steps: step 11) starting-up a rotary valve by pre-set low-speed rotary current; step 12) detecting a rotary angle of a turntable of the crane; step 13) judging whether the value of the detected rotary angle is greater than a threshold value, if the value of a detected rotary angle is not greater than the threshold value, turning to step 14); step 14) accumulating the low-speed rotary current, and gradually returning back to step 12). The low-speed rotary control method for the cranes can accurately set the needed low-speed rotary current with high efficiency while the low-speed rotary operation is needed. The invention further discloses a low-speed rotary control system of the cranes.

Description

technical field [0001] The invention relates to the technical field of cranes, in particular to a method for controlling low-speed slewing of a crane. The invention also relates to a low-speed slewing control system for the crane. Background technique [0002] The rubber-tyred crane is a kind of full-slewing crane that installs the crane on a special chassis composed of heavy-duty tires and axles. Wheeled cranes usually use a slewing mechanism to realize the slewing operation of the crane in the horizontal plane. [0003] Please see figure 1 , figure 2 , figure 1 It is a structural schematic diagram of a typical crane slewing mechanism; figure 2 for figure 1 Schematic diagram of the structure in direction A. [0004] Such as figure 1 , figure 2 As shown, the slewing mechanism of the rubber-tyred crane usually includes a slewing bearing 3, a slewing reducer 1, a slewing motor 2, a slewing valve, a controller, etc., and the large bottom plate of the turntable of th...

AI Technical Summary

Problems solved by technology

[0007] With the above technical solution, it is necessary to artificially set the low-speed slewing current, which has the following problems: since the buttons and displays for setting the current value are usually set in the control room, if the low-speed slewing current needs to be set, the staff needs to enter the control room to change it, thus It makes the operation inconvenient, and the accuracy of manually setting the current value is low. If the set current value is large, it will cause the low-speed rotation to be too fast, and it is necessary to constantly correct the rotation speed, which will affect the efficiency of the counterweight.

[0008] In addition, when the power is turned off and restarted, the temperature of the working oil will rise and the viscosity will decrease under the new working condition. The low-speed rotation current after manual setting will be relatively large, which will cause the low-speed rotation to be too large. In order to prevent the low-speed rotation from being too large, Manual setting is required to restore the low-speed slewing current to the factory current, which is inconvenient to operate

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