Design And Performance Analysis Of Unequal Pitch Step Plunge Milling Cutters

The industries of water,electricity and wind energy play an important role in the development of emerging industries in the country.Hydropower is the focus of the country.The core component is the hydraulic turbine.The structure of the hydraulic turbine is narrow spoon.With the introduction of "Made in China 2025",the country's requirements for manufacturing technology have gradually increased.At present,the processing of hydraulic turbine has gradually changed from welding processing to integral processing.The advantages of integral processing are many,and the processing methods are mostly plunge milling.machining.The length of the tool used in the plunge milling process is relatively large(the length to diameter ratio is generally 14:1).which will inevitably cause vibration during the machining process,reduce the machining efficiency and tool life,and affect the workpiece quality.In order to reduce the vibration during plunge milling,this paper introduces an unequal pitch structure;in order to improve machining efficiency and tool life,a stepped structure is introduced.In this paper,the design of the unequal pitch stepping cutter and performance analysis are used as the bus,processing stainless steel 0Cr13,the following research:First,the structural design of the unequal pitch step plunge milling cutter.Determine the structure of the plunge cutter by designing and analyzing the step structure,the rake angle and the range of the lead angle of the plunge cutter;Harmonic energy and minimum are used as the optimal tooth distribution density objective function,and the Fmincon method is used to optimize the tooth pitch to determine the inter-tooth angle of the plunge cutter.Secondly,the angle parameters of the unequal pitch step plunge milling cutter are preferred.The UG software is used to establish the 3D model of the unequal pitch step plunge milling cutter,and the finite element analysis is performed by ANSYS Workbench software to find the optimal combination of angle parameters and the dynamic balance analysis of the tool with the optimal angle parameter combination.Thirdly,verify the optimal angular parameter combination for the unequal pitch step plunge milling cutter.Deform-3D software was used to establish the simulation model of stainless steel 0Cr13 for unequal pitch step plunge milling cutter.The optimal angle parameter combination of unequal pitch step plunge milling cutter was verified by milling simulation,and the accuracy of simulation results was verified by experiments.Analyze the difference in milling force,temperature and tool wear between unequal pitch step plunge milling cutters and conventional plunge milling cutters.Finally,the fuzzy matter element evaluation is performed on the unequal pitch step plunge milling cutter.The fuzzy matter element evaluation model for milling performance of unequal pitch step plunge milling cutter is established.The evaluation index is determined by milling test: the values of milling force,acceleration and tool wear amount,and the milling performance of the unequal pitch stepped milling cutter is evaluated.according to the principle of minimum membership degree.