Experimental study of the relationship between the vibro-acoustic parameters of the grinding process and the macro-roughness of the treated surface

OBRABOTKAMETALLOV Vol. 23 No. 3 2021 technology Before the experiment begins, the allowance and traces of the previous operation are removed from the sample surface. The GW is corrected before each new experiment to ensure equal initial conditions and reduce the probability of a corresponding error. The signal was recorded via a compact microphone. The PC program “SOUNDFORGEPro 13.0” was chosen as a tool for working with the received acoustic data, as the most acceptable in terms of functionality, accessibility and ease of use. The coolant-cutting fluid (CCF) was fed into the cutting zone by the jet-pressure method through a nozzle located near the protective casing of the GW. The capacity of the feed pump is 12 l/min. Each experiment recorded the signal of the acoustic vibrations at a certain combination of experimental conditions ( S р i ; t i ). In addition, the real profile of each grinded sample in two sections was determined. The distance be - tween the sections was 5 mm. The determination of the size of the deviations in the shape of the samples was made using the coordinate measuring machine KIM-1000. The scanning method with a discreteness of 0.1 mm was applied. As a result, data on the coordinates of the point cloud for each sample were obtained, which are subject to further processing and analysis. Results and discussion The sound recorded on a digital medium represents a volume of data containing information on the change in the amplitude and frequency of the sound wave over time. The spectral analysis of the sound generated by the grinding process allowed us to determine the distribution of frequencies over the spectrum and its amplitudes at each moment in time. The amplitudes were recorded within the so-called informative frequency band of 700–780 Hz, established in the works of V. F. Guryanikhin [14–15]. The informative frequency band is directly related to the cutting process. Other sounds present in the recordings (e.g. of hydraulic pumps; of the high-frequency rotation of the grinding slide and other machine components; of the coolant-cutting fluid washing the cutting zone and returning to the system reservoir) differ from the grinding acoustics and have other frequency values, therefore, only the sound within the informative frequency band was analyzed. Fig. 1. Experiment scheme: 1 – grinding wheel; 2 – mandrel installed in the center of 3 ; 4 – steel 45 sample; 5 – microphone; 6 – personal computer