|Budget Amount *help
¥3,400,000 (Direct Cost : ¥3,400,000)
Fiscal Year 2003 : ¥1,200,000 (Direct Cost : ¥1,200,000)
Fiscal Year 2002 : ¥2,200,000 (Direct Cost : ¥2,200,000)
The four vitrified-bonded grinding wheels were fabricated and used in grinding tests. These wheels have the variable bond contents and pore ratios under the constant grain size and grain ratios (100mm in out diameter, 90mm in inner diameter and 5mm in thickness). We carried out the grinding tests under the conditions of wet, mist, cool air and cool-air mist modes. Face grinding was used for grinding test using a grinding center VKC-45. The workpiece is an annealed S500. The abrasive grain is PA. The shape of grinding wheel is cup-typed one. SURFTEST EST-600 was used to measure the ground surface roughness that was picked up in perpendicular direction to grinding scratch. SEM was used to observe ground surface and small chips produced in various cooling modes.
The ground surface roughness was obtained in cooling modes of. wet, cool-air mist and mist. In comparing roughness, the value was 4 p m in Ry in cool-air grinding. This is because cool air does not have lubrication effect, and the
cooling effect of cool air could not decrease the grinding heat that was produced by the friction heat due to the large contact zone of grinding. The ground surface roughness is small by the lubrication in each mode of wet, mist and cool-air mist. In comparing mist mode with cool-air mist mode, the surface roughness is large by the increase of pore rates in mist mode, but in cool-air mist mode, that does not change. This is because cool air has a role of cooling effect and the remove effect of chips by the easy flow through pores. The minimum roughness is obtained at 20-3OmIIhr in every wheel. The worse surface is obtained at lmJIhr due to burning and vibration by friction action that is caused by the small supply of mist. lit was cleared that the friction heat decreased by lubrication effect compared with cooling effect. In mist grinding, the, moderate volume of mist is 20-30m]Ihr. The pore rates of grinding wheel are 35 to 4Ovol%. The superiority of mist mode is clarified. In cool-air mist mode, the blowing method of cool air influences to the grinding performance of grinding wheel. Less