On the Influence of Infra-Red Sensor in the Accurate Estimation of Grinding Temperatures

Abstract

Workpiece rejection originated by thermal damage is of great concern in high added-value industries, such as automotive or aerospace. Surface temperature control is vital to avoid this kind of damage. Difficulties in empirical measurement of surface temperatures in-process imply the measurement in points other than the ground surface. Indirect estimation of temperatures demands the use of thermal models. Among the numerous temperature measuring techniques, infra-red measurement devices excel for their speed and accurate measurements. With all of this in mind, the current work presents a novel temperature estimation system, capable of accurate measurements below the surface as well as correct interpretation and estimation of temperatures. The estimation system was validated by using a series of tests in different grinding conditions that confirm the hypotheses of the error made when measuring temperatures in the workpiece below the surface in grinding. This method provides a flexible and precise way of estimating surface temperatures in grinding processes and has shown to reduce measurement error by up to 60%.

Model Based on an Effective Material-Removal Rate to Evaluate Specific Energy Consumption in Grinding

“…Finally, both the C45K and AISI 304 materials exhibited the same trend of decreasing energy consumption by increasing depth of cut and workpiece speed. Thus, thermal treatments had a noticeable influence on energy consumption, but temperature in grinding is also crucial and depends on the selection of the operational parameters [31]. The model of material-removal rate Qw developed in the present study is different from other models, as the thickness of chip (7) and the section of cutting grain (8) are the function of the angular position of the grain.…”

Expectations and limitations of Cyber-Physical Systems (CPS) for Advanced Manufacturing: A View from the Grinding Industry

“…In the case of the grinding process, this is a complex issue due to the characteristics of the process, including accounting for the small contact area between the tool (grinding wheel) and the ground part, high temperature gradients in the contact region (103-104 K/s) [37], poor accessibility to the contact zone, and the large quantity of grinding fluid over the working zone [23]. The easiest parameter to be acquired is the power consumption of the grinding wheel spindle during the process.…”

“…In [42] a state-of-the-art classification of the thermal measuring devices used and methods for material removal processes are presented. Considering these issues, a recent study by Urgoiti et al [37] developed a new two-color pyrometer-based optical fiber system for measuring the temperature of the ground part. In [43] a new possibility was proposed for the in-process measurement of workpiece temperature in cylindrical grinding.…”

Optical Fiber Pyrometer Designs for Temperature Measurements Depending on Object Size

“…Contact temperature sensors present the difficulty of placing them in difficult to access measuring zones; in particular, temperature measurements with thermocouples are highly influenced by the environmental temperature and the thermocouple length [ 3 , 4 ]. Due to the contact, they can also be destroyed when using them in high speed machining [ 5 , 6 , 7 , 8 ] and in grinding [ 9 ], where the workpiece is moving at a high speed. Some contact sensors present the drawback of a low response time depending on the employed technology and the geometry.…”