Study On Noise Detection And Sound Quality Evaluation Of Machine Tool

Now the noise pollution has been one big environment problem that is concerned popularly. The analysis and control on noise relates to the environment protection, the quality of life and health of body and mind, the competition ability of industry products. Our Country improved the noise standard of the machine tool in 1990. First quality machine is 81(dB). The base of solving noise and vibration lies in the research on sound resource. So the key is to research the sounding mechanism while machines are running, to find out the main sound resources of the equipments, then to control them. Now people care quality of life much more than before. Higher demands on sound quality are put forward. In many situations, sound quality is more important than sound intensity. This forces us to find out the called subjective evaluation index, which is based on the auditory characteristic of human ear, to evaluate the quality of sound.The dissertation researches and analyzes the main noise resource of machine tool— characteristic of gear and bearing noise and their generating mechanism then discusses the methods of depress noise. We use B&K2148 to get signals and MATLAB to process them. The noise and vibration signals are analyzed with FFT and cepstrum. We can find noise resources and depress them. We detected the noise of the CA6145i and the spindle bearing's vibration signal of CKS6116 by using B&K2148 and use MATLAB to process them. Noise and vibration sources were found based on spectrum analyses and some measures were taken to reduce or clear the noise and vibration. The dissertation discusses the characteristics of the human auditory system and its describable method and with this understanding establishes the objective method based on subjective perception. Then establishes a model of objective parameter of sound quality —loudness to provide more concrete criterion for the sound quality control.