Improving the efficiency of machining on metal-cutting machines by aligning the CNC program and the evolutionarily changing cutting dynamics

Abstract

Modern machines with high accuracy provide an accordance of the trajectories of the executive elements to the CNC program. However, this is not guarantee the same accuracy of manufacturing the part. One of the main reasons for the formation of the geometric defects is the elastic deformations of the tool and the workpiece. It is caused by variations of the cutting forces, changes in the rigidity of the workpiece along the tool path. It depends on changes of the properties of the dynamic link formed by cutting. Therefore, there is a problem of synergetic aligning of controlled trajectories with changing cutting properties. In the article, the regularities of the alignment of external control and internal dynamics are considered on the basis of mathematical modeling of the system in which the trajectories of the executive elements are controlled. The case of accounting the a priori given law of changes of the stiffness of the workpiece is considered. The effectiveness of the alignment is estimated by the reduced costs while ensuring the required quality of the parts.