FREQUENCY OF VIBRATION SIGNALS GENERATED IN METAL LAPPING PROCESS - - MODEL OF GENERATION OF VIBRATION SIGNALS-

摘要

This paper describes the generation mechanism of sound caused by mechanical actions of abrasives under lapping process. It has been shown that the surface roughness of the work can be monitored in process by detecting the power level of the vibration signals, in the frequency range of 1-3 kHz. To establish the monitoring technique, it is necessary to make clear the generation mechanism of vibration signals in lapping process. We assume a mass-spring system that consists of the work and the abrasive grains as a simple model for analyzing the vibration of the work. The elastic deformations of the contact portion between work and abrasive grains are regarded as springs and the work is regarded as mass so the Hertz's contact theory can be applied. The number and the representative diameter of abrasive grains that take part in the process were estimated from the enumeration data. In the vibration test, the resonance frequency of hte system obtained theoretically were fairly coincident with the experimental results under wide range of abrasive diameter and lapping pressure. It was also confirmed through the experiments of model lapping that the generated sounds ere distributed in the frequency region lower than the resonance frequency, and the distributions were in correspondence with the abrasive diameter and surface roughness.