Eventos Anais de eventos
COBEF 2023
12th Brazilian Congress on Manufacturing Engineering
Development of a workpiece temperature measurement device for radial turning
Submission Author:
Theodor Rucker van Caspel , SC , Brazil
Co-Authors:
Theodor Rucker van Caspel, Matheus Macedo de Roma , michel Tavares, Claudio Abilio da Silveira, Rolf Schroeter
Presenter: Theodor Rucker van Caspel
doi://10.26678/ABCM.COBEF2023.COF23-0313
Abstract
During the machining with a defined tool geometry, the machining force can decrease when the temperature in the cutting zone increases. This mostly occurs due a material softening that happens if the heat conduction allows it. In recent studies the passive and cutting force components decreased at constant cutting speeds during the hard radial turning of the Steel AISI 52100 HC 60. To confirm if there is still a temperature variation even at constant cutting speed, there was a need to measure the temperature along the process. Hence the objective of this work was to develop and test a temperature measuring device capable of measuring temperature in different points of the workpiece during the radial turning. The developed device uses a prototyping platform as basis and thermocouples embedded in the workpiece to measure temperature. The device was divided in three system, acquisition, amplification and fastening. The acquisition system was responsible for the control interface and data storage and was composed of the prototyping platform a microSD module, buttons and LEDs. The amplification system was responsible for amplifying the thermocouples signal and was composed by instrumentation amplifiers, thermocouples and a thermistor. The fastening system was responsible of holding the other systems inside the lathe chuck so the device would rotate with the workpiece and was composed by an aluminum case, and PVC tube section covered by rubber. Each system was projected and tested before a prototype was assembled. The prototype was capable of acquisition rates of 1 kHz in four channels, being three thermocouples channels and a thermistor channel for compensation. During the validation it was determined that the total errors are between 15 to 50 ºC. The temperature measuring device prototype was used to measure temperature during the radial turning of SAE 1040 steel. Though the prototype was able to measure the temperature, it presented failures modes. The most significant ones were the failure in the connection between the thermocouple and the amplification system, and wear in the fastening system. The former caused by incompatibility between the solder and thermocouple wires was solved by adding an intermediary wire. The latter was caused by wear on the fastening system and can be solved by redesigning the fastening system or by making the worn part replaceable.
Keywords
machining, Radial turning, temperature measurement
