ANALYSIS OF THE MACHINING SCHEME OF COMPLEX-PROFILES SHELLS OF ROTATION

Abstract

Modern engineering products have complex geometry with high quality requirements, are made from new materials that is provoked the development and use the mechanisms of parallel structure, which are distinguished by high rigidity characteristics, as well as have wide functional capabilities. The precision problems of machining of complex-profile low-rigid parts, in particular thin-walled pyroceram shell are considered in article. Scheme of machining affect the accuracy and depends on the capabilities of technological equipment. Rationale for scheme of machining a thin-walled casing is presented in article. The accuracy of machining the outer profile of the casing was simulated for last step of diamond grinding. The simulation was performed for a traditional scheme of machining, which is performed for a lathe with an aggregate grinding head and a direct copying system, and for a scheme of machining for equipment that is fitted out with a mechanism with a parallel structure. The model of formation of the machining error is based on using the equations of relative displacement of the technological bases of the workpiece and the contact point of the working surface of the diamond wheel with the workpiece. The model takes into account the static and dynamic characteristics of the technological system and force factors during grinding. The calculations have confirmed that proposed solutions are able to provide the necessary machining precision. Changing the machining scheme of the workpiece and performing such machining on equipment with mechanisms of parallel structures eliminates the basing error, increases the rigidity of the technological system, and provides the possibility of turning the axis of the diamond wheel with the required angle.