Research And Application Of Key Technologies In Automatic Control System Of Rotary Drilling Rig

As an important part of piling machinery,rotary drilling rig is mainly used for the construction of concrete pouring piles in engineering construction.It can cooperate with different working devices and drilling tools to perform drilling operations according to the construction requirements.This article analyzes and introduces the automatic control system of the rotary drilling rig from three aspects,they are: the multi-speed control and buffer oil supply system of the power head,the high-speed spin-off and automatic rotation system of the power head,the reliability improvement of the balance valve of the main winch motor and the main winch bottom protection and detection of drilling depth.These three aspects are researched and designed and tested to verify the feasibility of the scheme.Firstly,for the common control methods of hydraulic motors,based on the analysis of the working principle of the power head system and the calculation of main parameters,three power head control modes are proposed according to the electric proportional characteristics of the power head EP motor: rock entering mode,energy saving mode,and spin-off mode,and the control characteristics of each mode and the design of each gear parameter are given.the construction efficiency has been significantly improved.By comparing the advantages and disadvantages of the two-way relief valve and the one-way valve type,the independent charge valve system is proposed.The oil replenishment system increases the service life of the power head motor and reduces the failure rate.Secondly,according to the characteristics of the high-speed spin-off function of the rotary drilling rig,on the basis of the oil circuit of the high-speed reducer,by analyzing the corresponding high-speed spin-off scheme of the motor,the automatic shift high-speed spin-off scheme is designed using the working principle of the hydraulic shift mechanism.According to the control principle and operating characteristics of the hydraulic rotary drilling rig,an automatic rotation system of power head is designed,and the automatic rotation button is integrated on the pilot handle,which can realize the automatic rotation of the power head at any speed.Then,the necessity of using single-row rope winding for the main winch is analyzed,and the reliability improvement scheme of the main winch motor balance valve is studied.The bottom protection and overload protection of the main winch were designed to solve the problem of laying the wire rope down and avoidoverloading.Based on the analysis of the two commonly used detection methods of inductive sensor and incremental encoder,the detection scheme of the main winch Hall effect speed sensor is designed.The measurement accuracy and the construction efficiency are improved.Finally,the software and physical operation are used to test and verify the power head system and the main winch system to verify the feasibility of the design scheme.The result proves that the designed and researched power head and main winch control system designed and reserched can realize the related operation functions of the rotary drilling rig,and the design scheme is feasible.This paper has a total of 67 figures,12 tables and 60 references.