TECHNOLOGICAL DYNAMICS OF FINE BORING HOLES OF SMALL DIAMETER

Abstract

The article particularly studied oscillations cantilevered boring bar of small diameter (8 - 20 mm). Analytical condition vibrostability obtained with given parameters closed on the process of cutting the elastic system. Experimentally the stands fluctuations console borshtangi studied. In the measurements of forced oscillations used piezoelectric and strain gauges. We define the value of the flexural stiffness and the natural frequencies of the console of the boring bar. In the experiments in accordance with the theory of the vibrating cutting investigated the possibility of unstable damping boring bar (l/d>4) using additional axial vibrations with a certain amplitude and frequency. Shows oscillograms of flexural and torsional oscillations, their frequency and amplitude. Submitted estimating the ratio of amplitudes and frequencies of the flexural and torsional oscillations. It provides a method for increasing the flexural rigidity of the boring bar. Investigated increasing the flexural rigidity of the boring bar unstable with l/d>4 by precompression of the boring bar, which increases vibration during cutting. An example of the construction of prestressed boring bar as well as the values of the flexural rigidity.