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

OBRABOTKAMETALLOV Том 23 № 4 2021 TECHNOLOGY and angular displacements around the base points of technological subsystems are considered separately. The in fl uence to a large extent on an increase in angular displacements with an increase in the length of the workpiece is clearly displayed using the developed models. And this shows the need to take into account the in fl uence of angular displacements when processing non-rigid parts. The developed theoretical full-factor models of dimensional distortion for double-carriage adjustments re fl ect the in fl uence of the main technological and design factors and, for this reason, can be used in the design of operations to take into account the accuracy requirements. The established operability of full-factor matrix models and scope of its action, as a result, make it possible to use it as the basis of models for managing multi-tool double-carriage machining. The study of mathematical models for the formation of errors in the performed dimensions makes it possible to calculate the accuracy for various machining conditions. These models take into account the combined effect of a combination of factors – the characteristic of the rigidity of the subsystems of the technological system, the geometry of the cutting tool, the value of the bluntness of the tool, cutting conditions, etc. On the basis of the developed models, it is possible to determine the level of in fl uence of a complex of technological factors on machining accuracy – the structure of multi-tool adjustments, the deformation properties of the subsystems of the technological system, cutting conditions. The developed models make it possible to predict the accuracy of machining for given conditions (structure of adjustment, properties of the technological system, machining conditions), creating a methodlo-gical basis for computer-aided design systems for multi-tool turning. The developed full-factor matrix models of scattering fi elds of the performed dimensions in multi-tool double-carriage adjustments make it possible to calculate the error values of each performed dimension at the design stage for various adjustments and thereby create conditions for justifying the best option. To use this model in a real technological process, it is necessary to go either to a possibly set or possibly measurable value of a parameter of a real part or workpiece. For example, ∆ w1 – here, under the action of the cutting force, it calculates the constituent scattering fi eld caused by the elastic deformations of the technological system. At the same time, only the total scattering fi eld can be determined here. The model takes into account the change in the depth of cut, but we can really estimate the primary error of the workpiece. The presence of the actual complex matrix compliance characteristic for a real machine tool makes it possible to evaluate the practical applicability of the developed matrix models of machining accuracy. The developed models make it possible to determine the maximum permissible values of cutting condi- tions. In this way, for a given precision, the highest productivity during machining can be ensured. The developed models of displacements during solving the problem of designing machining on multi- purpose CNC machines can be transformed into control models. Due to the fact that the developed mod- els take into account the coordinate and angular displacements, it is possible to work according to the requirements of the scattering fi eld values of the performed dimensions and the shape error of the control models. References 1. Ahmad R., Tichadou S., Hascoet J.Y. A knowledge-based intelligent decision system for production plan- ning. The International Journal of Advanced Manufacturing Technology , 2017, vol. 89, iss. 5–8, pp. 1717–1729. DOI: 10.1007/s00170-016-9214-z . 2. Gasanov M., Kotliar A., Basova Y., Ivanova M., Panamariova O. Increasing of lathe equipment ef fi ciency by application of gang-tool holder. Advances in Manufacturing II . Lecture Notes in Mechanical Engineering . Cham, Springer, 2019, vol. 4, pp. 133–144. DOI: 10.1007/978-3-030-16943-5_12. 3. Trojanowska J., Kolinski A., Galusik D., Varela M.L.R., Machado J. A methodology of improvement of manufacturing productivity through increasing operational ef fi ciency of the production process. Advances in Manu- facturing. Lecture Notes in Mechanical Engineering . Cham, Springer, 2019, pp. 23–32. DOI: 10.1007/978-3- 319-68619-6_3 . 4. Usubamatov R., Zain Z.M., Sin T.C., Kapaeva S. Optimization of multi-tool machining processes with simul- taneous action. The International Journal of Advanced Manufacturing Technology , 2016, vol. 82, pp. 1227–1239. DOI: 10.1007/s00170-015-6920-x .