Model of Optimization of Process Parameters for Machining of Separate Design Elements of the Product

Optimization of process parameters for manufacturing of individual surfaces and the product as a whole is one of the key tasks of technological preparation of production. Processing of individual design elements of the product is a structurally complex process, which is a clear sequence of actions characterized by a set of parameters. The effectiveness of the optimization process directly depends on the level of detail of the process under study and the optimal choice of targets and control parameters. Thus, for a single design element of the product, the control task is reduced to the structural and parametric optimization of its processing. For this purpose, it is necessary to develop a hierarchical model of structural and parametric optimization of the processing of individual design elements of the product. The paper presents a structural hierarchical model of the design element forming process, describing the sequence of actions and intermediate states of the object at different control levels. The model is based on the structural decomposition of the process and includes three levels: technological processing route, technological transition, and working stroke. For each level, theoretical-multiple models, vector optimization criteria, control parameters, and boundary conditions are defined. The article also demonstrates the application of the model on the example of optimization for the process of shaping a group of threaded holes, where the Pareto-optimization method was used to obtain optimal machining parameters that reduced the labor intensity with an acceptable increase in error and surface roughness. The paper presents the results of controlling the machining process of a group of threaded holes by means of structural optimization of the machining process route and parametric optimization of cutting parameters for each working stroke. Optimal parameters of the machining process for the investigated group of threaded holes are achieved by reducing the number of technological transitions within the technological route of machining, as well as optimizing the value of cutting speed set in the process of tapping with a tapsetter. Thus, as a result of the optimization, the total labor intensity of individual transitions decreased by 18.3%, with an increase in processing error by 12.1%, and deterioration of the roughness parameter by 13.2%, which satisfies the initial conditions of optimization. The obtained results prove the effectiveness of the developed hierarchical model of controlling the process of machining individual design elements of the product through structural and parametric optimization of its individual stages.