Optimization of the number of stages of processing blanks of machine-building parts

The productivity of mechanical processing in the manufacture of parts of machine-building products is determined by the time spent on forming surfaces in accordance with the drawing and the number of processing stages necessary to achieve a given accuracy of the part from blanks of a particular accuracy. Due to the well-known property of the technological system associated with the technological inheritance of part errors from workpiece errors, the refinement of the workpiece dimensions is carried out in several stages. The required number of stages of processing (refinement) of the workpiece depends both on the properties of the technological system itself, and on the degree of variation of the input parameters of the workpiece and its processing modes. In addition, since the process of reducing the workpiece error depends on the scattering field of its dimensions, the required number of processing steps to achieve a given accuracy is mainly determined by changing the size of the dynamic setting at each of them. However, the size value itself is usually adjusted by changing the static/setting. The size of the dynamic adjustment occurs as a result of elastic movements of the elements of the technological system under the action of cutting forces. The larger the size of the dynamic setting differs from the setting size (the size of the static setting), the greater the error in the size performed. Errors caused by fluctuations in the size of the dynamic adjustment are difficult to compensate for, since they depend on many parameters: on the strength properties of the material being processed, on cutting modes, on the parameters of the cutting tool and its wear, on the rigidity of the technological system, etc. The article describes an approach to finding such combinations of process parameters that provide the shortest time for manufacturing parts and a given accuracy of measurement. For parametric optimization, the revealed regularities of the influence of the main parameters of the technological process on the coefficient of refinement of the workpiece dimensions at each stage of processing are considered.