Study On The Overall Numerical Control Machining Of The Pumped Storage Model Runner

Semi-open Pumped Storage runner is the representative part among complex surface machining,which is covered by multiple surfaces,and it has distinctive characteristics.Working face of the blade has complex shape,reflecting the comprehensive application of fluid mechanics,fluid machinery and many other subjects.Design methods,process planning and CNC machining could affect the final accuracy,quality and the performance of the products in many ways.Under the background of surface modeling and NC programming of Pumped Storage runner,this paper introduces the common modeling methods of the runner blade in detail and divides the multi-axis machining technology of the runner into process planning,tool path planning,tool axis without interference determining,process simulation,etc.The following are the main contents of this paper.Basing on B-spline curve theory,we build a pumped storage runner geometric modeling in Siemens NX by the way of constructing the line through points,the face through lines,afterwards,we start the CNC machining basing on the modeling.Completing the Analysis of Pumped Storage runner geometric feature,working out the best processing solutions of semi-open runner.Proposed subregional rough manner,processing the closing and open portion in the most efficient manner,while using sphere tool to complete the subregional finish machining,in order to avoid interference situations.According to the runner machining plan,wo complete further analysis of the runner machining process,including determining the rough area of the interface,the finishing regional division of blade surface and the hub surface,gouging manner.We proposed the plan to reduce roughing difficulties and improve processing efficiency of the program by increasing the processing groove.Giving a scientific method to divide sections,and method for generating sectional transition lines,constructed the transition surface from the processing groove to the blade surface,to determine the cutting layers of rough machining.Completing the analysis of the various interference situations during the cutting process,while figuring out a method to determine the interference-free tool axis vector.Combined with the setting the geometrical constraints in Siemens NX,this paper gives out the selection method of tool axis angles in sub-regional processing.This subject completes the simulation with the generated CNC program and gives out the general steps of the simulation.