Research On Load Sensing Hydraulic System Of Working Tools For The Motor Grader

As construction machinery, the motor grader is used to form and shape the roads, airports, irrigation and water conservancy, with a blade or many other kinds of replaceable work tools. In recent years, the load-sensing (LS) hydraulic technique has been widely used in the field of construction machinery, for example most motor graders abroad adopt this new technique. On the contrary, the use of LS technique for motor graders in our country is still in the initial stage.By comparing the traditional fixed hydraulic system with LS system of working tools, the necessity of the LS technique and its importance in energy efficiency are completely introduced. Based on the control system comprising the LS variable displacement pump and multi-channel valve, a design of hydraulic system and the system diagram for 190 motor grader are provided. Then the hydraulic system parameters are studied and determined under the optimized pressure range, including cylinder diameter and stroke, delivery capacity of the rotary motor, displacement of LS variable pump and flow of LS multi-channel valve etc. In accordance with the calculated parameters, the LS variable displacement pump and LS multi-channel valve are selected. The static characteristics are discussed, such as the efficiency of the LS system, the influence of load on the system flow and the flow distribution during the compound action. The simulation model of hydraulic system is established and simulated in AMESim. The simulation result verifies the feasibility.