Research On Rotary Positioning System Of The Rotary Drill Rig With Load-sensing Properties

Rotary drilling rig is a construction facility that is introduced into our country just in recent year. It is centralize highly in mechanical , electrical and hydraulic . It has many characteristics such as automatization is high , property of environmental protection is good , the efficiency of drilling is high , and progress is rapid , quality is reliable , flexibility is good , versatility , as well as layer adaptability is strong . It represents the development direction of stake work machinery , and gets the favor of construction department deeply . Piling rig is applied mainly to high-rise , road , bridge , power plant , airfield , large-scale port , deep-water dock and so on building projection stake foundation , has been popularized gradually interiorly .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 : start up,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.First of all , the application and development of the Hydraulic drilling rig is introduced . Then the significance and development of energy saving control of Hydraulic drilling rig in china and aboard are related , and then the development tendency is analysis and summarized in this paper .On the basis of the experimental of hydraulic drilling rig , several energy saving controls with multifunction valve control are investigate in this paper , which include negative control , positive control and loading sensing control .Apart from these , the paper also proposes several bump controls , which include cut off control of pump that can prevent several kinds of relief loss of hydraulic system , cross sensing control of pump that can enlarge the variable working range . the application of these strategy , not only improve the efficiency of hydraulic system , but also the controllability of hydraulic drilling rigs .In order to overcome the performance deficiencies of the hydraulic system applied in old drilling machine , and satisfy the requirements of high power drilling and the complex drilling control , this paper introduces a new scheme of drilling hydraulic system for improving the load adaptability , and a lot of analyses and the researches have been done such as the system structure , the control principle and the function characteristic etc . The researches establish the foundation of the automation and the intellectualization of drilling equipment for further improving the ablility of drilling control and load adaptability of the entire hydraulic drill and achieving the higher drilling efficiency. At present , the drill hydraulic system was instability which is easy to be influenced by load and has large energy loss and low drilling efficiency . For meeting the requirement of adapting to characteristic of load , this paper put forward the general scheme of new drill hydraulic system with load adaptability , which has the ability to monitoring and identifying variety of load in real-time , and can adjust states of control system automatically according to condition of load , for keeping optimum drilling efficiency.Then ,on the base of establishing the control model , by theoretical analysis and computer simulation , the further analyses and researches were carried out fully in this paper , which include the dynamic or static characteristic of load sensing system , key influential factor and load adaptability of drilling.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 ,loed-sensing control technology and energy-reclaim technology . Power matehing 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 : an simulation of the system by using AMESim 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 . the results indicate that the designed system is optimistics and both the energy saving and position Precession control are improved .The paper study the energy-saving control from the view of the engineering application , It has been proved by test that the combination of the energy saving methods that mentioned above , a satisfied result could be achieved . These methods can be realized on basis of most hydraulic system and diesel control system of Hydraulic drilling rig . The technology is urgent for the civil Hydraulic drilling rig . They will be valuable and significant for the development of Hydraulic drilling rig .