СНИЖЕНИЕ ВЛИЯНИЯ ВНУТРЕННИХ НАПРЯЖЕНИЙ ЗАГОТОВКИ В ПРОЦЕССЕ ОБРАБОТКИ НЕЖЕСТКИХ ДЕТАЛЕЙ

Abstract

The article considers the influence of internal stresses in the body of the workpiece on the change in its geometric parameters during milling of a part made of heat-strengthened aluminum with low structural rigidity. In addition, the method of milling such parts is shown. It allows to reduce the influence of internal stresses of the casting on the accuracy of the obtained dimensions. Measurements of the geometric parameters of the sample of the studied parts after roughing and finishing are made. Based on the study of the data obtained, a method is proposed to reduce the effect of internal stresses on the resulting size of the workpiece, which consists in changing the configuration of the workpiece for roughing and semi-finishing passes. The possibility of interpreting the internal stresses of the workpiece into an external load is considered in order to obtain approximate values of deviations of geometric parameters at intermediate stages of processing. Stress modeling of the workpiece with primary and new configurations is performed. The results of finite element analysis performed using Siemens NX CAD are studied. The obtained data are compared. It has been established that the use of a technique with an increase in the rigidity of the workpiece at the stage of roughing and semi-finishing leads to a decrease in the effect of warping of the casting on the magnitude of deviations in the final dimensions of the part. This leads to a decrease in processing time by reducing the number of finishing passes, as well as the aging time of the workpiece after rough removal of the allowance.