Research Of Dynamic Modeling And Electro-hydraulic Control Method For Valveless Impactor

Based on analyzing the working principle and control technology of hydraulic impactor at home and abroad, the paper presents a new type structure of valveless hydraulic impactor. This structure solves the problem of the machine becoming cumbersome, because the pure valveless hydraulic impactor should enlarge the structure in order to increase the impact energy. The design theory is studied; the alligiance among nitrogen chamber, accumulator and the impactor are analyzed.Then, according to the principle of the impactor, the mathematical model is established. By computer simulation, the actual working process of the impactor is researched. And the effect between all the relevant parameters and the impact performance is in detail analyzed. From the research, some knowledge about the regular moving is got. It not only provides a theoretical foundation for its overall design but also verifies the design theory.Finally, combined analyzing the working characteristics and engineering works of the impactor, which there is a rebound phenomenon in the impactor working process, and the rebound velocity can be reflected by the nitrogen chamber pressure. The rebound velocity is big if the pressure change is large, and so the impact energy needs to be increased; otherwise, the impact energy needs to be decreased. From the simulation result, it is known that the flow and the pressure have some influence to the impact performance. Therefore, the electro-hydraulic control systems are set and the nitrogen chamber pressure change works as the feedback signal. The pressure and the flow can be adjusted by the control system. Therefore, the impact performance parameters can be adjusted automatically. Two control schemes are proposed:the technology of vary frequency and the electro-hydraulic control for variable hydraulic pump. The characteristics of the two control schemes are analyzed theoretically, and finally the second scheme is selected and the electric circuit is analyzed.The above studies of the valveless hydraulic impactor have some reference value to its forward research and production.