Cutting force prediction method considering tooth spacing angles, helical angles and eccentricity of cutter

Abstract

The invention belongs to the technical field related to cutting force prediction in a metal machining process, and discloses a cutting force prediction method considering tooth spacing angles, helical angles and eccentricity of a cutter. The method comprises the following steps: (1) determining physical parameters of a workpiece, geometrical parameters of the cutter and machining parameters of a process; (2) dividing the cutting area of the cutter into multiple sections of cutting micro-units, and calculating cutter angle positions of the cutting micro-units at any moment, wherein the cutter operates in the cutting area; (3) calculating actual each tooth feed and instantaneous dynamic cut thickness of the cutting micro-units; (4) calculating shear flow stress, a shear force coefficient and a cutting edge force coefficient; (5) calculating cutting micro-unit force of the cutting micro-units in the tangential, radial and axial directions of the cutter, and transforming the micro-unit force to the X, Y and Z axes of a machine tool coordinate system via a Cartesian coordinate system; and (6) summing integrals of all the cutting micro-unit force achieving a cutting effect on each cutting edge to obtain three-dimensional dynamic cutting force at any moment.

Description

technical field [0001] The invention belongs to the relevant technical field of milling force prediction in the metal processing process, and more specifically relates to a milling force prediction method considering the inter-tooth angle, helix angle and eccentricity of a tool. Background technique [0002] End milling mainly uses the bottom edge and circumferential side edge of the tool to remove excess material on the surface of the part to be processed. Due to its high material removal efficiency, it is widely used in the manufacture of parts in high-end fields such as aerospace. In order to meet the requirements of parts for processing efficiency and processing accuracy, milling cutters with special structures (such as profiling cutters and variable pitch milling cutters) are gradually being used in industrial production. Among them, the variable tooth pitch milling cutter has the functions of reducing cutting chatter, improving the processing surface quality, prolongin...

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Problems solved by technology

[0003] At present, those skilled in the art have done some research, such as literature "Budak, E., Y.Altintas, and E.J.A.Armarego."Prediction of milling force coefficients from orthogonal cutting data."Journal of Manufacturing Science and Engineering118.2(1996 ): 216-224.” discloses the use of a large number of orthogonal turning experiments to establish a cutting database, and then calibrates the shear angle, friction angle and shear stress in the model. This method requires a large number of cutting experiments, and the cost of the experiment is high. , and once the tool geometry changes, it needs to be re-calibrated; another example is the document "Wan, Min, et al."A unified instantaneous cutting force model for flat end mills with variable geometries."Journal of Materials Processing Technology 214.3(2014):641 -650." discloses a general milling force modeling method for flat bottom milling cutters. This method uses two sets of milling experiments to calibrate physical parameters such as shear angle, friction angle and shear stress. Although the number of experiments and the cost of experiments are reduced, But there is still a re-experiment calibration process

To sum up, most of the existing cutting force prediction methods use physical parameters such as shear angle, friction angle, and shear stress included in the cutting force coefficient to obtain them through experimental calibration methods. The change of the helix angle requires re-calibration of the experiment, which is costly and inefficient

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