Rationale for granulometric medium characteristics under vibration processing of parts with small grooves and holes

Abstract

Introduction. The design technique for a highly efficient technological process of vibration finishing of parts with small grooves and holes is presented. The decision is based on the selection of the granulometric characteristics of the processing environments. The cross-sectional shape and geometrical dimensions of burrs on typical parts of radio electronic equipment (REE) are analyzed. A generalized burr model has been developed. Methodological principles for the selection of particle size characteristics of operating environments are determined. Materials and Methods. The new classification and coding according to the constructive and technological principles of REE components will provide reasonable selection of the equipment, environments and modes when designing their finishing process. Results. A technique has been developed for selecting the granulometric characteristics of operating environments with the account of the major technological problems. Based on the design and technological features of the REE components, the dependences are proposed for determining the size and shape of the processing granules. The acceptance criteria for evaluating the results of vibration processing are determined. It is noted that one of the major tasks in the vibration processing of parts with small grooves and holes is to provide such in-process time at which burrs are removed, and the roughness and other surface parameters meet the technical requirements. In this case, the accuracy of the linear dimensions of the processed surfaces should be considered an indicator of quality. Quantitatively, this criterion is assessed on a specific index whose calculation considers the largest actual size before vibration processing, the burr height, the smallest allowable size after processing, and the tolerance established by the technical requirements. The process efficiency criterion is defined as the ratio of the machinability index to the processing time of a batch of parts or the cycle time per part. The proposed criterion enables to compare treatment processes under validating the solution to technological problems. Discussion and Conclusions. The study results enable to confirm that vibration processing in the organic environment contributes to the effective removal of burrs and edge smoothing of small-sized parts of electronic equipment with small grooves and holes.