Eventos Anais de eventos
COBEM 2021
26th International Congress of Mechanical Engineering
A COMPARATIVE STUDY OF THERMAL ERRORS OF 5-AXIS MACHINING CENTERS OBTAINED USING THE LASER INTERFEROMETER DEVICE USING THE EXPERIMENTAL AND NUMERICAL METHODS
Submission Author:
Marcelo Otavio dos Santos , SP
Co-Authors:
Marcelo Otavio dos Santos , Ed Claudio Bordinassi, Adalto de Farias, Rodrigo Stoeterau, Gilmar Batalha
Presenter: Marcelo Otavio dos Santos
doi://10.26678/ABCM.COBEM2021.COB2021-0147
Abstract
This work aimed to measure and compare the thermal errors obtained in the linear axes X, Y and Z of a 5-axis universal machining center, by the experimental and numerical methods. The experimental data were obtained by an interferometer laser device measurements after carrying out heating cycles of the machine. The numerical results were obtained through the finite element modeling, simulating the heating cycles in the machine and collecting the thermal errors in the same stop positions that were considered in the experimental stage. The machine tool used to carry out this work was a 5-axis GROB universal machining center, model G550AB. The interferometer laser device used to measure the experimental thermal errors of the linear axes X, Y and Z of the machining center is type XL-80 from the manufacturer RENISHAW. For the experimental thermal monitoring, 15 temperature sensors were installed at critical points on the machine, which measured continuously, and recorded the temperature variation every 5 minutes. The measurements of thermal errors were divided into two stages. In the first stage, measurements were made in the condition of a “cold machine”, that means, the machining center had a temperature in equilibrium with the environment at 20°C. This step was intended to map the initial positioning errors of the machine. In the second stage, measurements were made after running a 4-hour heating cycle that was replicated for each axis individually. In the thermoelastic analysis by finite elements, the same operational and environmental conditions in which the machining center was exposed during the experimental stage were depicted, such as axis speeds, machine movement periods and ambient temperature. Error measurements were made at 33 stop positions on each linear axis of the machine, which represented an error reading every 23 mm. Through this methodology it was possible to validate the numerical model of the machining center, which allow to predict the thermal behavior of the machining center in situations for which it has not been tested experimentally. For the three axes analyzed, the results were quite satisfactory, with the differences between the experimentally measured and simulated errors being less than 7.5 μm for the X axis, less than 9.6 μm for the Y axis and less than 2.5 μm for the Z axis, considering the total travel of each axis.
Keywords
Thermal error, 5-axis machining center, interferometer laser device, finite elements method
