Noise research under flat parts processing through ball-and-rod reinforcement

Introduction. Research results of the part surface treatment by a ball-and-rod reinforcer (multicontact shock-vibrating tool) through the surface plastic deformation method are provided. The considered process can be used for hardening both flat and curved surfaces, as well as for generating compressing residual voltages, pocket smoothing, regular microrelief fitting on friction pairs, and for joint weld machining. When carrying out this research, the manufacturing processability is identified, the regularities of selecting design data of the device are determined. The treatment process is percussive, and it is attended by heavy acoustic radiation. It is found that noise under processing far exceeds the allowable range. Materials and Methods. The investigation was conducted on a universal milling machine. Long flat parts were exposed to hardening. The parts were installed directly on the machine table or in special devices. A line noise source was accepted as a model. Research Results. Dependences are obtained for determining the sound pressure, natural frequencies of the part oscillations, and noise spectra. A set of noise abatement procedures under processing is worked out. A considerable amount of the experimental research confirming adequacy of the obtained theoretical models is undertaken. Discussion and Conclusions. When carrying out the studies, it is established that efficiency in noise abatement cannot be obtained by the rational selection of the vibration-absorbing material. In this regard, the use of passive noise protection of the machine site in the form of a flat polycarbonate-glass screen is recommended. This will allow reducing noise in the work zone to the standard values. Design data of the offered acoustic screen are calculated.