KATSUKI Masahide Toshiba Machine Co., LTD.Precision Machine Division, Manager, 精密機械事業部, 事業部長(研究職)
SAKAI Yasuo Sakai Laboratory for Precision Machining, Head, 所長
KUSUI Naoki Numazu College of Tech. Mechanical Engineering, Professor, 機械工学科, 教授 (50259868)
|Budget Amount *help
¥6,500,000 (Direct Cost : ¥6,500,000)
Fiscal Year 2000 : ¥600,000 (Direct Cost : ¥600,000)
Fiscal Year 1999 : ¥400,000 (Direct Cost : ¥400,000)
Fiscal Year 1998 : ¥5,500,000 (Direct Cost : ¥5,500,000)
The apparatus, which was newly developed in order to process the signal of grinding sound, detects the elastic wave, which propagates through the workpiece and electromagnetic chuck, by an AE (Acoustic emission) sensor. After applying Wavelet transform to the elastic wave signal, the result is output as a three-dimensional color diagram formed by frequency, time and spectral intensity.
By applying the monitor for grinding phenomena to a series of surface plunge grinding by vitrified boded WA wheel, GC wheel and also a cylindrical plunge grinding by vitrified bonded CBN wheel in a production shop, the following conclusions are conducted.
(1)By excuting Wavelet transform as data processing of the AE signal, which occurs in the grinding region between the wheel and workpiece material, the frequency component caused by the fracture or wear of abrasive grain and bond material is separated from that caused by the workpiece material.
(2)In the surface grinding by WA wheel the components at near
3 kHz and 9 kHz are caused by the fracture of WA (white alundum) grain and workpiece material S45C repectivery. On the other hand, in the surface grinding by GC wheel the components at near 2 kHz and 10 kHz are caused by the fracture of GC (green carborundum) grain and workpiece material FC25 respectively.
(3)By monitoring the intensity of the frequency component caused by the fracture of abrasive grain in the progress of grinding operation, the monitor developed enables us to decide the redress life of grinding wheel scientifically and reasonably instead of the excellent sense and experiment by a skilled machinest.
(4)The trouble, that is, the initial grinding power after truing-dressing operation becomes large extremely besides the intial surface ground roughness is inferior to the expected value, occurs often during grinding operation by CBN wheel in many production shops. The cause of trouble have been revealed by applying the monitor.
(5)By monitoring the intensity of the frequency component caused by the fracture of workpiece material during grinding brittle materials such as Silicon wafer, ferrite, ceramic, glass and so on, the monitor enables us to detect the occurrence of workpiece having substandard accuracy in the grinding operation. Less