Modeling, Simulation And Optimization Of Hydraulic Impactor Which Matched With Special-purpose Vehicles

Hydraulic impactor is an impact machinery, it can make use of the hydraulic to make the piston reciprocate and to achieve the purpose of crushing objects. The reversing valve of traditional hydraulic impactor can automatically change its location, in terms of this type of hydraulic impactor, impact energy of piston is proportional to the square of the pump flow, and piston frequency is proportional to the pump flow. When changing the pump flow, it affects energy larger than frequency. When improve the impact frequency to shorten the working time, the piston velocity may be too fast, the piston and rod will take place plastic deformation. In order to overcome this shortcoming of traditional hydraulic impactor, this paper had a certain type of hydraulic impactor as a prototype, according to the principle of pressure feedback of hydraulic impactor, adding a pilot cone valve to the reversing valve to make hydraulic impactor adjust impact energy and impact frequency independently.According to the possible combinations of movement state of piston, reversing valve and pilot cone valve, the motion of the hydraulic impactor with pilot cone valve was divided into 7 stages within one cycle. According to the 7 stages, the non-linear mathematic model was established and the theoretical analysis of the adjusting range of pilot cone valve was made.According to the non-linear mathematical model, the simulation constraints were determined, the MATLAB/Simulink simulation model of hydraulic impactor was established, and the different stages of hydraulic impactor can convert successfully by using Stateflow module. Comparing the motion graph of the simulation results and the motion graph of the experimental results, which proves the simulation model of the hydraulic impactor is basically correct. It can be used to do the simulation research. Then how do the main parameters affect the impact velocity was analyzed. The simulation results showed when preset force value is reasonable; the pilot cone valve can adjust impact energy and impact frequency independently.Most of hydraulic impactor parameters once identified, you can not change them, doing physical orthogonal experiment costs too much. Aiming at the shortage of physical orthogonal experiment, the design of experiment module in Isight software was used. Orthogonal experiment based on co-simulation was done by using Isight and MATLAB/Simulink. The simulation results of orthogonal experiment show that the interation between the effective area of piston front chamber and the effective area of piston back chamber is obvious, and the impact of the interaction between these two factors on hydraulic impactor is the second. As a single factor, the effective area of piston back chamber is the most influential factor of impact velocity.Although the experiment can find out a greater impact factor, but it can not find out the optimal solution. To solve this problem, optimization design method was used. Co-simulation was done by using Isight and MATLAB/Simulink and used NLPQL algorithm and MIGA algorithm as optimization method respectively. The effective area of piston front chamber, the effective area of piston back chamber, precharge pressure of high-pressure accumulator and the location of signal feedback port were selected as design variables, and two algorithms were used to optimize impact velocity when impact velocity was constrained and when impact velocity was not constrained respectively. The comparison research was done between the results of two algorithms.