Measurement of Tool Temperature Using Thermal Imaging in Interrupted Cut Turning

Author(s):  
Scott Smith ◽  
Bethany A. Woody ◽  
David A. Tursky ◽  
William E. Barkman

The creation of oscillating tool paths for turning operations that use the numerically controlled machine axes to ensure reliable chip breaking has been demonstrated in a variety of materials. The interrupted cuts created in this way have the additional benefit of allowing the temperature of the tool-chip interface to be controlled at a significantly lower level than in conventional turning. In traditional continuous turning, the interface temperature rises to a high level and stays there during machining. This is especially a problem for difficult-to-machine materials, because many tool wear mechanisms are strongly temperature dependent. In the chip breaking tool paths, the axes of the machine are used to oscillate the tool along the programmed tool path and before the temperature has a chance to rise to damaging levels, the cut can be interrupted so that the tool can cool. This is analogous to the technique of using shallow radial depths of cut in milling operations for difficult-to-machine materials. In this work, a thermal imaging camera is used to verify that this strategy can be effective in the machining of steel. The results from the thermal imaging studies show that over a broad range of conditions, oscillating tools paths create lower temperatures at the tool-chip interface.

Author(s):  
Adam Jacso ◽  
Tibor Szalay ◽  
Juan Carlos Jauregui ◽  
Juvenal Rodriguez Resendiz

Many applications are available for the syntactic and semantic verification of NC milling tool paths in simulation environments. However, these solutions – similar to the conventional tool path generation methods – are generally based on geometric considerations, and for that reason they cannot address varying cutting conditions. This paper introduces a new application of a simulation algorithm that is capable of producing all the necessary geometric information about the machining process in question for the purpose of further technological analysis. For performing such an analysis, an image space-based NC simulation algorithm is recommended, since in the case of complex tool paths it is impossible to provide an analytical description of the process of material removal. The information obtained from the simulation can be used not only for simple analyses, but also for optimisation purposes with a view to increasing machining efficiency.


2021 ◽  
pp. 112067212110237
Author(s):  
Ari Leshno ◽  
Ori Stern ◽  
Yaniv Barkana ◽  
Noa Kapelushnik ◽  
Reut Singer ◽  
...  

Purpose: Accumulating evidence suggests that neuroinflammation and immune response are part of the sequence of pathological events leading to optic nerve damage in glaucoma. Changes in tissue temperature due to inflammation can be measured by thermographic imaging. We investigated the ocular surface temperature (OST) profile of glaucomatous eyes to better understand the pathophysiology of these conditions. Methods: Subjects diagnosed with glaucoma (primary open angle glaucoma [POAG] or pseudo exfoliation glaucoma [PXFG]) treated at the Sam Rothberg Glaucoma Center (11/2019–11/2020.) were recruited. Healthy subjects with no ocular disease served as controls. The Therm-App thermal imaging camera was used for OST acquisition. Room and body temperatures were recorded, and the mean temperatures of the medial cantus, lateral cantus, and cornea were calculated with image processing software. Results: Thermographic images were obtained from 52 subjects (52 eyes: 25 POAG and 27 PXFG) and 66 controls (66 eyes). Eyes with glaucoma had a significantly higher OST compared to controls (mean 0.9 ± 0.3°C, p < 0.005). The difference between the two groups remained significant after adjustment for age, sex, intraocular pressure (IOP) and room and body temperatures. Lens status and topical IOP-lowering medication did not significantly affect OST. A subgroup analysis revealed that the OST was higher among eyes with POAG compared to eyes with PXFG, but not significantly. Conclusions: Differences in the OST between glaucomatous and normal eyes strengthens current thinking that inflammation affects the pathophysiology of glaucoma. Longitudinal studies are warranted to establish the prognostic value of thermographic evaluations in these patients.


Energies ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3258
Author(s):  
Dawid Szurgacz ◽  
Sergey Zhironkin ◽  
Stefan Vöth ◽  
Jiří Pokorný ◽  
A.J.S. (Sam) Spearing ◽  
...  

The paper discusses the results of a study carried out to determine the thermal condition of a conveyor power unit using a thermal imaging camera. The tests covered conveyors in the main haulage system carrying coal from a longwall. The measurements were taken with a thermal imaging diagnostic method which measures infrared radiation emitted by an object. This technology provides a means of assessing the imminence and severity of a possible failure or damage. The method is a non-contact measuring technique and offers great advantages in an underground mine. The thermograms were analysed by comparing the temperature distribution. An analysis of the operating time of the conveyors was also carried out and the causes of the thermal condition were determined. The main purpose of the research was to detect changes in thermal state during the operation of a belt conveyor that could indicate failure and permit early maintenance and eliminate the chance of a fire. The article also discusses the construction and principle of operation of a thermal imaging camera. The findings obtained from the research analysis on determining the thermal condition of the conveyor drive unit are a valuable source of information for the mine’s maintenance service.


Author(s):  
Avadhesh Kumar Sharma ◽  
Mayank Modak ◽  
Santosh K. Sahu

Impinging jets are commonly utilized in the run-out table (ROT) cooling in the hot rolling process in steel manufacturing industries. The phenomenon of rapid cooling of a sufficiently hot surface is termed as the quenching. The present paper reports the rewetting behavior of 0.15 mm thick hot moving stainless steel foil (SS-304) by circular impinging jet from bottom side through experimental investigation. The transient temperature of the hot foil is recorded by using thermal imaging camera (A655sc, FLIR system). Tests are performed for a varied range of Reynolds number (Re = 2500–10000), nozzle to plate distance (z/d = 6), moving plate velocity (0–40 mm/s) and initial surface temperature 500±10 °C. Transient temperature obtained from thermal imaging camera is used to evaluate rewetting time and rewetting velocity. Based on the experimental investigation correlation has been proposed to predict non-dimensional rewetting velocity as a function of various parameters, namely, Reynolds number, non-dimensional axial distance and moving plate velocity.


2011 ◽  
Vol 399-401 ◽  
pp. 1763-1767
Author(s):  
Ri Pan ◽  
Wei Yang ◽  
Yin Biao Guo ◽  
Feng Yang ◽  
Dong Xu Zhang

Computer controlled optical surfacing (CCOS) is widely used in aspheric optical lenses fabrication because of their high convergence rate on surface based on deterministic removal processes since 1963. As an important part of CCOS techniques, reasonable tool-path would increase the polishing speed, decrease the processing time and then improve the efficiency of polishing. Optimized policy combined with improved Prim algorithm is presented in this paper based on the study of the characteristic of aspheric polishing and the tool-paths in common use. The simulated results show that the length of tool-path is reduced so as to decrease the processing time and increase the working efficiency.


1983 ◽  
Vol 105 (3) ◽  
pp. 192-199 ◽  
Author(s):  
T. Watanabe ◽  
S. Iwai

Adaptive control to keep the accuracy of the shape of a workpiece within acceptable levels by altering the numerical control commands according to variations of manufacturing process parameters is called “geometric adaptive control.” In this paper, a geometric adaptive control system to compensate for errors in the finished surface due to tool deflection generated by milling operations is presented. The effects of cutting forces upon the shape of the finished surface are analyzed, and the composition of the system is discussed. In the system, the location error and the waviness error at the finished surface are evaluated from the sensed bending moments in the tool. These two errors are compensated for by shifting the tool path and by adjusting the feedrate, respectively. It is verified by experiments that the accuracy of the finished surface is improved significantly by using the system described in cases where the depth of cut varies. Geometric adaptive control is useful even when a workpiece is machined by both rough and finish cuts.


2011 ◽  
Vol 223 ◽  
pp. 691-700 ◽  
Author(s):  
Xavier Beudaert ◽  
Pierre Yves Pechard ◽  
Christophe Tournier

In the context of 5-axis flank milling, the machining of non-developable ruled surfaces may lead to complex tool paths to minimize undercut and overcut. The curvature characteristics of these tool paths generate slowdowns affecting the machining time and the quality of the machined surface. The tool path has to be as smooth as possible while respecting the maximum allowed tolerance. In this paper, an iterative approach is proposed to smooth an initial tool path. An indicator of the maximum feedrate is computed using the kinematical constraints of the considered machine tool, especially the maximum velocity, acceleration and jerk. Then, joint coordinates of the tool path are locally smoothed in order to raise the effective feedrate in the area of interest. Machining simulation based on a N-buffer algorithm is used to control undercut and overcut. This method has been tested in flank milling of an impeller and can be applied in 3 to 5-axis machining.


Author(s):  
M. Fatih Toy ◽  
Onur Ferhanoglu ◽  
Hamdi Torun ◽  
F. Levent Degertekin ◽  
Hakan Urey

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