Rotary Drilling Rig On The Bus Rotary Hydraulic System Energy-saving And Positioning Control

Rotary drilling rig is a constructing equipment of integration of mechanics, electrics and hydraulic in the construction machinery which is used to drill deep hole and the depth of the hole can be up to tens of meters. Rotating of upper part is a frequent action while working and its rotating position precision relates to the drilling quality; rotating action is composed of three parts: startup, rotating and stop. Because of the great change of load, regulating of system parameter and designing action are very important to save energy and improve working efficiency.Based on the character of rotary action, analyzing traditional rotary systems in construction machinery, an electric hydraulic proportional closed-loop control system and the electric control system are designed for the upper rotary part by using of the electro-hydraulic proportional control technology, load-sensing control technology and energy-reclaim technology. Power matching of the system based on variational load was gotten by appling the load-sensing control technology and energy-saving control with using accumulator to absorb braking energy was established by energy-reclaim technology. By using these technology on above, rotary control position precession is improved. Mathematics model of the system was founded by using the method of power bonds graph; an simulation of the system by using MATLAB was taken when parameters are changed and accumulator is used or not and the results were analyzed to indicate that using accumulator can save energy a lot and optimizing parameter of system structure and PID control parameter can improve control precession greatly. According to the experiment of SWDM-20, the results indicate that the designed system is optimistics and both the energy saving and position precession control are improved.