Hydraulic System Design And Simulation Of Heavy Horizontal Directional Drilling

Horizontal direction drilling machinery is one of the special trenchless equipments,which can be also widely used to laying, repair and replacementin underground pipeline with conditions that are banned or can not be excavated,such as, through buildings, rivers, highway, railway, downtown and vegetation reserve. This equipment is one revolution to the method of traditional underground pipeline excavation construction. Since entered engineering construction market, it has achieved good social and economic benefites with increasing attention in a short time in view of unique feature and advantage on technology, especially the advantage of lowing impact and damage to urban traffic and environment as well as improveing efficiency and lowing cost.Horizontal directional drilling of transmission and control mainly using hydraulic technology, therefore hydraulic system performance will have a direct impact on the machinery’s performance. This paper examines the present state and development trend under contrast the levels of horizontal direction drilling machinery at home and abroad first. Then, the author confirmes the suitable hydraulic drive form of the machinery based on analysis of three types of driving scheme, the hydraulic design scheme of 280t horizontal direction drilling machinery is dealt with in the end. The manufacturer type test shows that, the design of hydraulic system can meet the related technical requirements. On this basis, simulation of the power head hydraulic system that the main working element was studied, simulation models of the power head spin and push-pull hydraulic system were established. Simulation parameters of main elements to power head including power head spin and push-pull speed, flow of variable displacement pump, variable displacement motor and the system pressure were derived based on researchs of circumstances in load dispersion-decreasing and load mutations. In addition, influence of load change to hydraulic system was discussed.The simulation analysis shows that change feedback control system parameter of the variable pump-variable-displacement motor, can make output torques of the motor obviously ascension in a certain speed range, thereby the efficiency of the horizontal directional drilling is improved. In addition, Through simulation also proved setting the accumulator in rig working loop can effectively reduce rig start-up system pressure shock, be helpful for improving hydraulic components using life.The research contents of this papar have certain theoretical significance to hydraulic system design and improvement of large-tonnage horizontal direction drilling machinery.