| Budget Amount *help |
¥8,800,000 (Direct Cost: ¥8,800,000)
Fiscal Year 1997: ¥1,500,000 (Direct Cost: ¥1,500,000)
Fiscal Year 1996: ¥7,300,000 (Direct Cost: ¥7,300,000)
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| Research Abstract |
This project deals with the development of a new machining method for small 3-demensional parts such as micro-aspherical lens, die and mirror. It is trying to machine the small parts utilizing a micro-grinding and polishing processes. A diamond quill for the conventional machining process has a small diameter (0.1-1.0mm), however manufacturing of the quill is very difficult and a tool life becomes short. A new method, which is one of field-assisted fine finishing methods, is developed to solve these problems. It is named an electro-reological (ER) fluid assisted polishing. In this process, polishing slurry is mixture of fine abrasive (diamond, GC or WA) and ER fluid. A strong electric field (0-3kV/mm) is applied between a very sharp tool like a needle (positive electrode) and a ground electrode (negative electrode). Then, viscosity of the ER fluid is increased, and the abrasive particles are softly hold around the tip of the tool. In this experiment, abrasive particles gathering around the tool tip are observed through a CCD microscope. It is clear that the each abrasive particle is connected with one another in a line like a string of beads, and moving with the ER fluid toward the tool tip. The tool tip is performed as a very small wheel in grinding and polishing the small parts. The necessary instrumentation and control system of the ER fluid assisted polishing have been designed and built. The polishing machine has a 3-axis nano-positioning table and an ultra-precision air spindle. Using this polishing system, basic machining tests were carried out. The polishing rate was 20mum/15min. The ER fluid assisted polishing method that we developed demonstrated excellent polishing performance. This method is applicable for manufacturing not only micro-size optics for industrial micro devices, but also micro-aspheric lens for medical applications such as an endoscope, which will be widely used in the near future.
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