Predicting method of flexible machining surface error of large disc mining cutter plane cutting

Abstract

The invention discloses a predicting method of a flexible machining surface error of large disc mining cutter plane cutting, and relates to the field of prediction of the machining surface error. Thepredicting method comprises the following steps of building a single-step analysis standard finite element model, extracting an analysis file, building a main circulation analysis step to obtain a node position and an initial value of a flexible main circulation cutting force set, initializing a flexible main circulation finite element analysis model file to determine instantaneous cutting force of a subsidiary circulation cutting position, updating a subsidiary circulation finite element analysis model file, conducting finite element analysis, conducting flexible machining error calculation,judging whether subsidiary circulation of the flexible machining error calculation is converged or not, judging whether the cutting process is finished or not and conducting surface machining error point cloud processing to obtain a surface machining error cloud graph. By means of the method, after a large disc milling cutter is machined, the whole surface flexible machining error form can be simulated, the plane milling machining error forming mechanism of the large disc milling cutter is studied more comprehensively, and a prerequisite is provided for design of the machining process and control strategy development of the machining process.

Description

technical field [0001] The invention relates to the field of prediction of machining surface errors, in particular to a prediction method for flexible machining surface errors of large disc milling cutter plane milling. Background technique [0002] The surface milling method of large disc milling cutter is widely used in the actual production of engine block and cylinder head. The surface quality of engine block and cylinder head processed by this method is not only an important index The tightness of the cover is closely related. Face milling is a process of material removal. During the cutting process, due to the existence of cutting force, the workpiece will be deformed, causing the actual cutting depth at the cutting position to deviate from the nominal cutting position, and the material removal rate will change. The surface quality fluctuates, which affects the service performance of the machined surface. [0003] There are usually two types of plane flexible machini...

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Problems solved by technology

Due to the use of direct finite element method, it can better predict the thermal deformation of instantaneous machining, mainly for the research of cutting mechanism, but the efficiency is low and the simulation range is small 5mm×15mm, which cannot be applied to the machining error simulation of large complex workpiece surface

In the paper "Machined surface error analysis-a face milling approach" (Journal of Advanced Manufacturing Systems, Vol. 10, No. 2, 2011, pages 293-307), EYSION et al. proposed to import the flexibility matrix extracted by ANSYS into MATLAB for direct calculation. The method of processing deformation mainly adopts the uniform force loading measured in the actual experiment, and adopts the single-point loading analysis method in the end mill, which is only suitable for the simulation of flatness in the analysis of plane milling; and the flexibility matrix is ​​used The extraction method only analyzes the machining error under elastic deformation, and cannot consider the flexible machining error of the workpiece under the action of multiple teeth, and is not suitable for the simulation prediction of surface flexible machining deformation of multi-tooth disc milling cutters

The Chinese patent "A Method for Simulation and Prediction of Surface Roughness and Surface Topography in Turning and Milling Composite Cutting" (publication number CN102592035A) proposes a cutting surface topography simulation method combining geometric simulation and physical simulation, through the method of geometric mapping Superimpose the dynamic and static motion of the workpiece to form the surface machining residual morphology, which belongs to the roughness scale range, and is not suitable for the simulation of surface machining errors mainly caused by machining deformation in plane milling, especially the simulation of flexible machining errors

[0007] The current simulation prediction of milling surface quality mainly focuses on instantaneous processing deformation, or processing deformation at multiple specific cutting positions. The main method is the application of single-point external load, which cannot consider flexible processing under the simultaneous action of multiple points during instantaneous cutting. The simulation prediction of the flexible machining error shape during the multi-tooth face milling process of a large disc milling cutter in the time domain cannot be realized

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