| Summary: | 碩士 === 國立中山大學 === 機械工程研究所 === 86 === A process planning strategy for the HDP process to compensate a form error with small wavelength is proposed in this study. This strategy applied a proportional relationship between machining depth and machining time to design a proper dwelling time distribution for tool (to remove form error of work surface).The designing procedure of this strategy consists of two steps.The first step is to design an initial dwelling time distribution from the error profile of work surface according to a linear rule. An iterative process is then executed to modify the dwelling time distribution in the second step. A series of computer simulations and experimental study are conducted to examine the validity of this strategy. From the computer simulations, several points are concluded. First, a good machining precision can be obtained if the machining zone is smaller than the wavelength of error profile. Second, the precision is little affected by tool resolution (distance between two conjunctive tool positions).Third, it is not effective to improve precision by simply increasing an uniform machining depth. Finally, the major errors are occurred at the boundary of machining area. Several conclusions can be also reached from the experimental study. First, the machining rate will be significantly reduced due to tool wear. Second, the error profile with wavelength considerably smaller than the machining zone can be treated as surface roughness and effectively removed during the polishing process. Third, this strategy is shown to have capability to shape an arbitrary profile. Finally, by applying this strategy, a flat surface with maximum error 0.15 μm can be achieved, which has an initial error of 2 μm. The study suggested that the error profile with small wavelength can be accurately removed from the proposed strategy. Hence, the HDP process can be applied to obtain a high or ultra-precision work surface.
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