| Summary: | 碩士 === 國立雲林科技大學 === 機械工程技術研究所 === 87 === The industry today is one that strongly stresses quality. Accordingly, any product requires strictly good quality. Good quality is so required that the manufacturing processes and process techniques are demandingly fine. And then, there exists competence only with low costs. Because products of recent electronic and information industries are tending towards small volumes, high accuracy, less weights and high performance with the development of continuously compactor and lighter sizes, the demands on process techniques and accuracy are getting more strigent day by day.
However, the existing problems of quality on the most useful technology of drilling are always what we want to deal with. Especially, problems about small diameters and deep holes are the most urgent. With decreases in hole diameter, the degree of difficulty of processing is getting higher and higher. There are still a lot of limitations to reach high cutting efficiency. The processing skills of small-diameter holes are: The mechanical removal of cutting and grinding, the application of EBM and LBM , and the plastic processes of punching. As for the productivity and economy, the cutting process is still more prevalent.
High-frequency (supersonic wave) vibration or low-frequency vibration can improve the drilling characteristics of small-diameter holes, but the research methodology in the past are to vibrate with micro amplitudes in the direction of spindle. The complexity of vibration devices and the workability of practical use are hence significantly increased. In this research, the one-side vibration to the work table fixed by the workpiece is employed in virtue of an actuator through piece-electrical vibration with micro-amplitudes, and that is a simpler way to do, so that the micro-amplitudes vibration is instantly produced and the goal of high cutting efficiency is attained. There are a lot of ways to processing small-diameter holes, but the cutting process is still more prevalent. The problems of quality due to cutting are hole dilating, roundness, roughness of hole walls, positioning accuracy, burr, etc. Hi-frequency or low-frequency is used in this research to improve the quality of drilling small-diameter holes. The way of vibration used is to vitalize an actuacfor to instantly produce micro-amplitudes vibration via piezo-electrical materials and cooperates with linear slide guides to ensure uni-directional vibration for the target of high cutting-efficiency.
A self-made vibration work table cooperates with available machine centers and micro-drilling fixture to conduct a series of experiments so as to inquire into the effects of such factors as the magnitudes of amplitude, frequency, rpm, feed on processing small-diameter holes with/without vibration. By the use of Taguchi Methods, palm the process conditions of experiments to simplify the number of times of experiments and to help find the optimal experimental parameters.
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