Method for predicting milling stability based on piecewise Hermite interpolation polynomial and overall discrete strategy

Abstract

The invention relates to a method for predicting milling stability based on a piecewise Hermite interpolation polynomial and an overall discrete strategy, which comprises the following steps: firstly,constructing a high-speed milling system kinetic model considering a regeneration effect, and equally dividing a forced vibration stage into a plurality of small time periods on the basis of the high-speed milling system kinetic model; and then adopting a piecewise Hermite interpolation polynomial to integrally approach a period coefficient item, a state item and a time lag item in a kinetic equation to obtain a state transfer matrix of the milling system in an adjacent period, then calculating the spectral radius of the state transfer matrix, and judging the stability of the milling system according to the Floquet theory. Compared with an existing semi-discrete and integral discrete method, the method has the advantages that prediction precision and calculation efficiency are improved, then the high-speed milling flutter stability lobe graph is efficiently and accurately constructed, reasonable cutting parameters are selected through the milling flutter stability lobe graph, flutter-free stable cutting machining is achieved, and better surface quality and machining precision are obtained.

Description

technical field [0001] The invention relates to the field of advanced manufacturing technology, in particular to a method for predicting milling stability based on a piecewise Hermite interpolation polynomial and an overall discrete strategy. Background technique [0002] As the most common and important machining technology, CNC milling has the advantages of small deformation, low milling force, high precision and high efficiency, and is widely used in precision machining of key parts in the fields of aviation, aerospace and vehicle machinery manufacturing middle. The milling process is often accompanied by various vibrations, which will accelerate tool wear and damage, seriously affect the surface quality of the workpiece, greatly restrict the machining accuracy and efficiency, and even damage the machine tool equipment. In order to suppress the occurrence of chatter, the stability of milling processing is predicted, and the spindle speed and depth of cut are reasonably s...

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Problems solved by technology

But the calculation accuracy is poor

Literature "Qin CJ, Tao JF, Liu CL. A novel stability prediction method for milling operations using the holistic-interpolation scheme. Proceedings of the institution of mechanical engineers Part C: Journal of Mechanical Engineering Science 2019; 233(13):4463–4475"( Corresponding to the Chinese patent document "CN110162733A") discloses a milling stability analysis method based on an overall discrete strategy, which has high computational efficiency but low computational accuracy

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