Research On Closed Hydraulic Control System In Hoisting Mechanism Of Crawler Crane

As one of the vital mechanism of crawler crane, the hoisting mechanism's dynamic properities can directly affect the working performance of the whole machine. At present, most foreign manufactures have adopted the full closed hydraulic system, however, only a small number of domestic products used such systems.Compared with the open hydraulic system, the closed hydraulic system is characterized by:independent movements based on the single motor and single pump system; more stable transmission and less energy loss and hydraulic impact; preventing the falling back phenomenon by the electrical control method; easy arrangement and less pipeline connection; the low probability of failure; the electrical control system's importance to the safety of the whole machine. Therefore, using the closed hydraulic system simulation analysis methods to resolve the key problems during the design of crawler cranes is of great practical significance.In this paper, the dynamic simulation study on the closed hydraulic system in the hoisting mechanism is on the background of the pre-research project closed electro-hydraulic control platform, which is developed by the research group.(1) Based on the study of the closed hydraulic system principle and the characteristics of the closed hydraulic system, the second lifting control method is achieved under the control of joystick, pressure memory and the brake release time.(2) The electro-hydraulic control principle of the closed electro-hydraulic control platform is designed. According to the calculation results of the hoisting mechanism, the components are selected and the three-dimensional modeling of the platform is established.(3) The pressure function of the high-pressure chamber and the control principle are presented. Meanwhile, the dynamic curves of load and joystick moving, and brake release time are output.(4) Based on the simulation software, the simulation model of the joystick and motor with closed hydraulic system is built up, and the simulation results justify the control method.(5) The second lifting control programme is completed through the codesys platform, which concludes the fuzzy control algorithm based on the closed electro-hydraulic control platform.