Multi-cavity structural part processing step sequence decision method based on transition characteristic simplification

Abstract

The invention discloses a multi-cavity structural part processing step sequence decision method based on transition characteristic simplification. The method sequentially comprises the steps that thecharacteristics and cavity corner requirements of a processed workpiece are judged, and a processing procedure model of the processed workpiece is extracted from a three-dimensional processing technology design system; an algorithm is utilized to automatically construct an auxiliary plane by extracting relevant geometric elements of transition characteristics, and transition characteristic segments are constructed; the geometric elements corresponding to the transition characteristics are reconstructed based on the transition characteristic segments, and an accurate tool advancing position isobtained according to the relation among the geometric elements; processing elements are given to coordinates of the obtained tool advancing position, technological information is defined in a processing element information entity, and a mathematical expression of a processing element information model is generated; a genetic algorithm of an elitism strategy is adopted to perform optimal orderingon the processing elements, and an optimal tool feeding path is obtained; and finally the obtained optimal tool feeding path is matched with the technological information of corresponding processing steps, and an intelligent decision result of a processing step sequence is obtained.

Description

technical field [0001] The invention belongs to the technical field of digital processing, and relates to a processing step decision method, in particular to a multi-cavity structural part processing step sequence decision method based on transition feature simplification. Background technique [0002] Cavity is a common structure in aircraft structural parts and mold design. In actual production and manufacturing, it is usually processed by CNC milling. Large-size multi-cavity parts have a large overall outline size (the overall size of the aircraft structure can reach 4000mm×2000mm), a large number of cavities and a long distance from each other. An important factor that cannot be ignored in the decision-making process. The process planning of multi-cavity parts needs to consider the cavity contour and its spatial position relationship. In the case of keeping the cutting method unchanged, the number of tool changes and idle strokes should be reduced as much as possible. ...

AI Technical Summary

Problems solved by technology

These algorithms mainly have the following problems: (1) The processing feature distance depends on manual calculation

The manual calculation result is used as the parameter input of the optimization algorithm, not only the degree of intelligence is low, but also it is difficult to guarantee the accuracy of the calculation result; (2) The influence of the transition feature on the tool path planning is not considered

Transition features widely exist at the corners of the cavity, and the NC machining of transition features on the outer contour of the cavity can be realized by simply modifying the tool offset parameters; while machining the inner contour, an auxiliary transition circle must be artificially added by the programmer arc, and it must be ensured that the radius of the transition arc is greater than the radius of the tool, which not only increases the difficulty of NC programming, but also slightly negligent, when the radius of the transition arc is smaller than the radius of the tool, overcutting will occur due to tool interference, and the processed parts will be scrapped

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