상용 코드를 이용한 개구변위에 따른 굴삭기 스풀 밸브 노치의 유동특성 해석

초록

The main control valve system is a key functional component to control excavators and other mobile hydraulics machines. Several types of spool valves have been designed to provide the main control valve with the necessary functions. It is quite difficult to predict the transient flow characteristics caused by the moving spool. Even though the notch is properly designed and equipped in the spool, the flow patterns change depending on how to move the spool, making its control deviate from the linear theory. In this paper, a Computational Fluid Dynamics (CFD) code, FLUENT 18.1, is used to analyze transient, 3-D flow characteristics based on the opening ratios of specific types of spool valve notches used in the excavator. Based on the steady-state and the transient simulations, the flow characteristics such as flowrate, discharge coefficient, and flow forces are compared, and the vortical structures downstream of notches are discussed.