Development of a wireless system for milling temperature monitoring

Abstract

Cutting temperature is a critical aspect in machining operations, directly influencing tool wear and the quality of the workpiece; therefore, cutting temperature monitoring and control present great importance for costs optimization. One of the techniques usually employed to measure temperature in machining operations consists of embedding a thermocouple in the cutting tool near the rake face. However, this method becomes difficult to apply in operations where the tool rotates during cutting, such as in milling and drilling. In light of these facts, this paper describes the development of a wireless measurement system capable of monitoring the temperature in rotating tools during machining employing the concept of the embedded thermocouple method. A Bluetooth connection made possible data transmission from the measurement system to the computer, allowing a maximum sampling rate of 450 samples per second. To validate the developed system, tests were performed to measure the temperature when milling AISI D2 steel with coated tungsten carbide indexable inserts. The findings showed that the proposed system is capable of evaluating the temperature behavior for different cutting conditions. For cutting speeds of 60, 90, and 180 m/min, temperatures of 138, 159, and 181 °C, respectively, were recorded after 7 s of milling. One of the principal contributions of this work is the high sensitivity of the developed system with regard to changes in cutting conditions, thus contributing to the determination of the optimal cutting conditions in operations that employ rotating tools.