Research on correction method of inertia factor of starting section of gap flow opening in hydraulic rock drill

Abstract

ABSTRACT Large pulsation and impact occur during the working process of hydraulic rock drill, which has a negative influence on the system. Aiming at this phenomenon, the related characteristics of hydraulic fluid inertia are studied in this paper. The dynamic model of impact and reversing mechanism of rock drill is established. Through the parameter analysis of the model, the concepts of hard parameter quantity and soft parameter quantity are proposed. The influence coefficient C of the initial section of crevice flow including the influence of fluid inertia is deduced, and the comprehensive factors such as hydraulic oil velocity, unstable flow and friction resistance are analyzed, The value of soft parameter quantity ζ is (ξ+1) ~ (ξ+ 1.5)。The pressure test of the working chamber is designed and 7 groups of data are obtained. Through data analysis, the influence of C on the simulation results is obtained, which has a great influence on the reversing valve. The deviation of simulation data of left and right valve chamber pressure is increased from ± 8% to ± 3%. It has a certain impact on the impact piston. The deviation of simulation data increases from ± 5% to ± 3%, and has little impact on the accumulator. The deviation of simulation data increases from ± 4% to ± 3%.