Sources and Control of Mechanical Vibrations Affecting Machine Tool Performance Quality (Phase II)

摘要

An investigation of the external and internal sources of vibration in machining operations which impair the performance quality of conventional machine tools was conducted as an extension of the study made in Phase I (AD-625 103). Particular effort in this investigation was concentrated upon the effects of external vibration relative to the performance of machine tools: (a) environmental floor vibration under normal working conditions in the shop, (b) determination of the sensitivity of the cutter workpiece system to floor disturbance under various machine support conditions, (c) effect of floor vibrations on surface finish and accuracy, (d) vibration transmissibility characteristics from floor-to-machine and machine-to-floor under various machine support conditions. An isolated reaction mass of reinforced concrete was constructed and calibrated. A knee-type milling machine was placed on the platform using various types of isolators and varying shock impulses were applied by a shock machine on the platform. Separate tests on a cylindrical grinding machine were made to study the effect of wheel unbalance on the resulting surface characteristics. Further investigation on a drill press vibration was carried out to determine experimentally the dominant factors controlling vibration during drilling operations. (Author)