Research On Control Method Of Hydraulic Impact Of Pumping System Of Wet Spraying Machine

Abstract:Wet spraying machine is a kind of machine which widely used in underground engineering, geotechnical engineering and strengthening project. It plays an important role in the modern constructing. The hydraulic system is one of the most important parts of wet spraying machine. However, there are serious problems of hydraulic impact in the pump hydraulic system of wet spraying machine. Hydraulic impact would cause vibration, noise, and would have great influence on the working performance and service life of wet spraying machine. Since the wet spraying machine is progressing towards higher pressure and larger displacement, the problem of hydraulic impact will become more serious. Therefore, how to reduce or even eliminate the hydraulic impact has important theoretical and practical value.Firstly, according to the working principle of pumping system of wet spraying machine and though the theoretical analysis on the phenomenon of hydraulic impact in direction changing process, a variable displacement method was raised. Under the requirement of piston not striking the bottom of cylinder and piston stroke control accuracy, the pumping direction changing process time parameters and the displacement control time parameters was optimized.Secondly, the flowing state of the concrete in the pipe and the pressure loss was analyzed according to the principle of rheology. And the wet spraying machine pumping load model was established. The main oil pump for pumping system was modeled, and its dynamic and static characteristics were analyzed. The pumping hydraulic system model of wet spraying machine was built with the simulation software AMESim, and the simulation analysis of the pumping system was done. The simulation results verified that the variable displacement control method is effective for reducing hydraulic impact of the pumping system.Finally, the experimental study was carried on a type of wet spraying machine. By comparing the experiment results of two different experimental conditions of hydraulic pumping system with the variable displacement control and without the variable displacement control, the theoretical analysis was further verified, and the experiment results also proved the validity of the variable displacement control method.