Full-factor matrix model of accuracy of dimensions performed on CNC multipurpose machines

OBRABOTKAMETALLOV Vol. 23 No. 4 2021 TECHNOLOGY Full-factor matrix model of accuracy of dimensions performed on multi-purpose CNC machines Nizami Yusubov a, * , Heyran Abbasova b Department of Machine Building, Azerbaijan Technical University, 25 H. Cavid avenue, Baku, AZ1073, Azerbaijan a https://orcid.org/0000-0002-6009-9909, nizami.yusubov@aztu.edu.az, b https://orcid.org/0000-0002-0407-5275, abbasova.heyran@aztu.edu.az Obrabotka metallov (tekhnologiya, oborudovanie, instrumenty) = Metal Working and Material Science. 2021 vol. 23 no. 4 pp. 6–20 ISSN: 1994-6309 (print) / 2541-819X (online) DOI: 10.17212/1994-6309-2021-23.4-6-20 Obrabotka metallov - Metal Working and Material Science Journal homepage: http://journals.nstu.ru/obrabotka_metallov ARTICLE INFO Article history : Received: 07 July 2021 Revised: 06 August 2021 Accepted: 07 September 2021 Available online: 15 December 2021 Keywords : Multi-purpose CNC machines Machining accuracy Full-factor accuracy model Scattering fi elds of performed dimensions Matrix of compliance Plane-parallel matrix of compliance Angle matrix of compliance ABSTRACT Introduction. One of the main reasons that modern multi-purpose CNC machines do not use the capabilities of multi-tool processing is the lack of recommendations for design in this direction and, accordingly, for adjustment schemes. The study of the possibilities of multi-tool processing on multi-purpose machines is the subject of the work. The purpose of research: The problem of developing full-factor matrix models of dimensional accuracy and its sensitivity to the machining process is considered to increase the machining ef fi ciency while ensuring machining accuracy using the technological capabilities of multi-tool machining on modern multi-purpose CNC machines. For this purpose, full-factor matrix models of the size scattering fi elds performed on multi-tool double-carriage adjustments have been developed, taking into account the cases of processing parts with dimensions that differ sharply in different directions, which are often encountered in practice, and in this case, the signi fi cant in fl uence of the turns of the workpiece on the processing error, especially in directions with sharply different overall dimensions. Results of research: The developed accuracy models make it possible to calculate not only plane-parallel displacements of the technological system for double-carriage adjustments, but also angular displacements around base points, take into account the combined effect of many factors – a complex characteristic of the subsystems of the technological system (plane-parallel matrix of compliance and angular matrix of compliance), the geometry of the cutting tool , the amount of bluntness of the tool, cutting conditions, etc. As a result, based on the developed accuracy models, it is possible to obtain several ways to control multi-tool machining, including improving the structure of multi-tool adjustments, calculating the limiting values of cutting conditions. Based on the developed full-factor matrix models, it became possible to develop recommendations for the design of adjustments and the creation of an automated design system for multi-tool machining for a group of modern multi-purpose CNC lathes. Scope of the results: The results obtained can be used to create mathematical support for the design of operations in CAD-systems provided for multi-tool multi-carriage machining performed on multi-purpose machines. Conclusions: The developed models and methodology for simulating the machining accuracy make it possible to increase the accuracy and ef fi ciency of simultaneous machining, to predict the machining accuracy within the speci fi ed conditions. For citation: Yusubov N.D., Abbasova H.M. Full-factor matrix model of accuracy of dimensions performed on multi-purpose CNC machines. Obrabotka metallov (tekhnologiya, oborudovanie, instrumenty) = Metal Working and Material Science , 2021, vol. 23, no. 4, pp. 6–20. DOI: 10.17212/1994-6309-2021-23.4-6-20. (In Russian). ______ * Corresponding author Yusubov Nizami D., D.Sc. (Engineering), Professor Azerbaijan Technical University, 25 H. Javid avenue, AZ 1073, Baku, Azerbaijan Tel.: +994 (55) 324 50 12, e-mail: nizami.yusubov@aztu.edu.az Introduction The high cost of modern machine tools with numerical control (CNC) in the world market dictates the need to use the technological capabilities of these machines at a high level. Here, not only the reduction in processing time is of great importance, but even the minimization of auxiliary times. One of the ways to improve the productivity of machining on CNC machines is to take advantage of the multitool machining capabilities of these machines. Multi-tool machining is an integral part of machine building. Multi-tool adjustments, which have great potential for concentration of transitions, make it possible to perform all the shaping technological