Modeling and optimization of B-axis hydraulic delay for gantry-type CNC machine tool

Abstract

Due to the limitation of dimension, structure and material, aviation structural workpiece is usually processed by AB rotary axis five-axis CNC gantry-type machine tools with large torque. However, the B-axis mechanical structure of gantry-type machine tools is complex and bulky, and hydraulic system is adopted for gravity balance. After the long production period of the machine tool, the hydraulic balance force of the B-axis is lost immediately and the spindle goes out of control when it emergency stops, which seriously endangers the quality of workpiece. In view of this phenomenon, this paper takes the hydraulic control system of machine tool as the breakthrough point, and analyzes the hydraulic system without adjusting the mechanical structure. And the mathematical model of hydraulic system is established. The hydraulic control system of B-axis is optimized by the simulation of MATLAB/Simulink. On the premise of improving the stability of the system, the duration of hydraulic balance force is extended, and the deflection time of 2 seconds is delayed, which effectively reduces the processing risk of workpiece.