|Budget Amount *help
¥3,400,000 (Direct Cost : ¥3,400,000)
Fiscal Year 2000 : ¥500,000 (Direct Cost : ¥500,000)
Fiscal Year 1999 : ¥800,000 (Direct Cost : ¥800,000)
Fiscal Year 1998 : ¥2,100,000 (Direct Cost : ¥2,100,000)
In the field of precision machinery, stainless steel capillaries having fine hole and lomg size has been needed for the flow line of pure gas and liquid. In order to finish the inner wall of such a capillary, new polishing method, in which polishing is performed by letting the slurry flow through the capillary at high speed, has been developed, and it has proved to exibit excellent polishing performance. The effects of number of slurry pass, grain size, slurry injection pressure and inner diameter of the capillary are examined.
With increasing number of slurry pass, the surface roughness of as received capillaries decreases rapidly in the early stage of low number of slurry passes, and tends to saturate toa certain level depending on the abrasive grain size. Successive polishing with using fine grains after polishing with coarse grains is effective in further reduction of surface roughness. The decreasing surface roughness of the inner wall results in the increasing conductance of gas flow through the capillary. Accounting for the effect of the capillary diameter on the diffrential pressure which is measured in nitrogen gas flow through the capillary at a constant flow rate, an empirical equation is found between the diffrential pressure and surface roughness.