Features of machine cyclogram optimization with the account of interaction of mechanism links with stops
Introduction. Cyclogram optimization of a technological machine with the account of interaction of the mechanisms links with stop members is discussed. The analysis of scientific literature indicates that cyclogram optimization for complex machines with the account of elastic-dissipative characteristics of the mechanisms needs additional research. Usually simplified dynamic models, which do not take into account elasticity of driven links are used for cyclogram optimization. The urgency of the study is justified by the fact that the existing dynamic models can not be used to calculate the vibrations excited by impacts of the working bodies on the limit stops, when entering into contact with elastic elements. The goal of the study: to improve the cyclogram synthesis method for a technological machine making it possible to increase its productivity. In this study a cyclogram of a technological machine presented in the form of mathematical models using networks for interaction of mechanisms is investigated. STB shuttleless loom, which is a complex technological machine with many executive mechanisms with interconnected movements, is used as the object of the study. During solution of the optimization problem it is necessary to increase the limiting operation time by decreasing the time for technological operations in mechanism groups. The problem for each group is mathematically formulated as an optimization problem on a network graph. The mechanism of microshuttle lift for the STB loom is used in this study. Method of investigation: cyclogram optimization using dynamic models of mechanisms is used. Results and discussion: dynamic models of mechanisms taking into account the interaction of driven links with limiting stop mechanisms are suggested. Dynamic errors of motion laws for a camshaft mechanism operating at the main shaft rotation rate n = 280…420 min-1 with a stop impact are calculated. The mechanism vibrations at natural frequency after contact with the stop are studied. Limitations of the cyclogram optimization problem with the account of the executive link vibrations and impact interaction with the limiting stop are formulated.