Transformation of Deviations from the Roundness of the Inner Cylindrical Surface of the Hydraulic Cylinder During Its Manufacture

Abstract

The article presents the results of determining the accuracy of the shape of the cross-section and obtained numerical values of the statistical characteristics of dispersion of deviations from the roundness of the surface of the cylinder sleeve of the telescoping boom of the KTA-25 automobile crane after each technological operation of its processing.

The impact of technological operations on the amount of deviation from roundness and the prevailing harmonics, which indicate the type of shape deviation, is determined. Moreover, the form of deviations from roundness is preserved after the first two operations. This indicates the presence of the phenomenon of technological heredity. Polygons for scattering deviations from roundness were built for deviations from roundness after each technological operation. It was established that the technological operation of semi-clean boring does not significantly change either the size or the shape of the deviation from the roundness of the inner cylindrical surface of the hydraulic cylinder sleeve.

The shape of the deviation from roundness will help to establish the defect of the machine tool and prevent the formation of detected deviations from the roundness of the processed surfaces. After performing rough and semi-finish boring, the first harmonic prevails in the distribution of amplitudes of harmonics of deviations from roundness. This indicates that during blade processing operations on the machine tool, radial beating of the spindle takes place.

The consequence of this is the formed eccentricity of the treated surface. After performing the finishing operation - final rolling, the third harmonic begins to prevail in the amplitude distribution of harmonics of deviations from roundness. It was established that the amount of deviations from roundness after the semi-clean boring operation does not significantly decrease with the shape of the deviation preserved, which indicates its ineffectiveness in terms of influence on the accuracy of the shape of the cross-sections when processing the inner cylindrical surface of the hydraulic cylinder sleeve.