Emitter-Receiver Piezoelectric Transducers Applied in Monitoring Material Removal of Workpiece during Grinding Process

摘要

Grinding is one of the most commonly used finishing processes in the manufacture of precision components that also needs to be monitored. Monitoring of the workpiece surface quality is considered highly complex due to particularities of the cutting tool and material removal mechanism. In this context, the monitoring of the grinding process is very important for the metalworking industry and a topic of great interest for machining researchers. Many studies on grinding process monitoring have been developed and most of them focus on process automation. The objective of this work is to monitor the workpiece material removal during grinding by using piezoelectric transducers in the emitter and receiver modes along with digital signal-processing techniques. Tests were performed on a peripheral surface grinding machine equipped with an aluminum oxide grinding wheel. The SAE 4340 steel grade was used as workpiece material. The transducer signals were sampled at a sampling frequency of 2 MHz. The digital signal processing was performed through spectrum analysis and the application of techniques such as root mean square. The mass of the workpieces was measured by means of a digital scale prior to and after grinding tests. The number of grinding passes was varied in order to increase the material removal. The results show that the monitoring technique proposed in this work is sensitive to the material removal in the grinding process. The appropriate selection of frequency bands allows for the best diagnosis in relation to the events that occur during the grinding process.