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Wyszukujesz frazę "thermal error" wg kryterium: Temat


Tytuł:
Effects of hot chips in dry cutting processes on the temperature field and displacement of the machine tool table
Autorzy:
Albrecht, Tom
Thiem, Xaver
Penter, Lars
Ihlenfeldt, Steffen
Powiązania:
https://bibliotekanauki.pl/articles/99659.pdf
Data publikacji:
2019
Wydawca:
Wrocławska Rada Federacji Stowarzyszeń Naukowo-Technicznych
Tematy:
accuracy
thermal error
deformation
Opis:
In machining up to 75% of the geometrical variations of work piece, features are caused by thermally induced deformations of machine components [1]. Since in dry cutting up to 80% of the thermal energy is stored in the chips [2], we expected a significant effect of these process-dependent heat sources on the machine accuracy. Based on preliminary simulation results, we systematically applied determined quantities of heated chips to a machine table to understand their impact on the temperature field. Temperature sensors where used to measure the temperature change on the tables surface and in the structure. Length measuring probes measured the corresponding deformations at 24 points distributed over the table. The measurements show a temperature change of 4 K at the surface and 3 K in the structure near the heat source after 6 minutes of exposure to 500°C chips. In this case, the impact on the temperature field is local but causes the bending of the table. We recorded 8 micron of thermo-elastic deformations. The results suggest that high-accuracy processes with large energy input, such as hard turning, require the heat induced into the machine structure by hot chips to be implemented into compensation methods and correction algorithms.
Źródło:
Journal of Machine Engineering; 2019, 19, 3; 31-42
1895-7595
2391-8071
Pojawia się w:
Journal of Machine Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Robustness and portability of machine tool thermal error compensation model based on control of participating thermal sources
Autorzy:
Mares, M.
Horejs, O.
Hornych, J.
Smolik, J.
Powiązania:
https://bibliotekanauki.pl/articles/99925.pdf
Data publikacji:
2013
Wydawca:
Wrocławska Rada Federacji Stowarzyszeń Naukowo-Technicznych
Tematy:
control
machine tool
thermal error
transfer function
Opis:
Thermal errors caused by the influence of internal and external heat sources in machine tool structure can cause more than 50% of total machine tool inaccuracy. Therefore, research on thermal behavior of machine tool structures is crucial for successful manufacturing. This paper provides an insight into the modeling of highly nonlinear machine tool thermal errors using thermal transfer functions (TTF). The method is dynamic (uses machine tool thermal history) and its modeling and calculation speed is suitable for real-time applications. The method does not require interventions into the machine tool structure, uses very few additional gauges and solves separately each influence participating on thermal error. The paper focuses on the development of a robust thermal model sensitive to various machine tool thermal behavior nonlinearities with the help of minimum input information. Model was applied on real machine tool (portal milling centre) and was verified within a complicated electro-spindle revolution spectrum. Moreover, the said compensation model was applied on another machine tool to prove its robustness and portability among machines of the same type set and the results of the TTF model were compared with a model obtained via multiple linear regression (MLR) as a case study.
Źródło:
Journal of Machine Engineering; 2013, 13, 1; 24-36
1895-7595
2391-8071
Pojawia się w:
Journal of Machine Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Real-Time Compensation of Machine Tool Thermal Error Including Cutting Process
Autorzy:
Horejs, O.
Mares, M.
Hornych, J.
Powiązania:
https://bibliotekanauki.pl/articles/99782.pdf
Data publikacji:
2015
Wydawca:
Wrocławska Rada Federacji Stowarzyszeń Naukowo-Technicznych
Tematy:
thermal error
real-time compensation
cutting process
Opis:
The challenge to be addressed by this paper is to extend the common machine tool thermal compensation models considering only internal heat sources to include the effects of the cutting process. Although real-time software compensations of thermal errors exist, the majority of these models only presume machine tools under load-free rotation of the main spindle without any reference to rough machining. The machining process is completely neglected in spite of the fact that it represents a significant heat source and causes workpiece inaccuracy. This paper presents a real-time compensation of three-axis vertical milling centre thermal errors including the cutting process effect. The simulation is based on dynamic modelling using transfer functions. The model was implemented into a standard CNC controller of a three-axis vertical milling centre to compensate for thermal errors in real time. The inputs of the compensation algorithm are the spindle rotational speed, the 5 temperatures of the machine structure and spindle power. A reduction of thermal errors achieved by using the new approximation TF model including cutting process impact is up to 79% for steel cutting tests with different cutting conditions.
Źródło:
Journal of Machine Engineering; 2015, 15, 3; 5-18
1895-7595
2391-8071
Pojawia się w:
Journal of Machine Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Decreasing of thermal errors in a lathe by forced cooling of ball screws and a headstock
Autorzy:
Winiarski, Z.
Kowal, Z.
Błażejewski, A.
Powiązania:
https://bibliotekanauki.pl/articles/1429161.pdf
Data publikacji:
2008
Wydawca:
Wrocławska Rada Federacji Stowarzyszeń Naukowo-Technicznych
Tematy:
lathe
feed mechanism
cooling
thermal error
calculation
Opis:
The goal of this paper is to present the effective methods of decreasing thermal deformations of a turning centre's structure in order to reduce the thermal error. The design of a machine tool as well as the scope of analyses are described, and calculation methods are specified. The paper also presents the results of computer simulations, concerning studies on the influence of type and parameters of a headstock-cooling liquid on the reduction of spindle displacements. Moreover, the results of feed mechanism's thermal studies are shown, describing the influence of heat generated during the operation of ball screws and their inner liquid cooling, on tool's thermal displacements.
Źródło:
Journal of Machine Engineering; 2008, 8, 4; 122-130
1895-7595
2391-8071
Pojawia się w:
Journal of Machine Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Compensation of machine tool angular thermal errors using controlled internal heat sources
Autorzy:
Mares, M.
Horejs, O.
Hornych, J.
Kohut, P.
Powiązania:
https://bibliotekanauki.pl/articles/971270.pdf
Data publikacji:
2011
Wydawca:
Wrocławska Rada Federacji Stowarzyszeń Naukowo-Technicznych
Tematy:
control
machine tool
angular thermal error
transfer function
Opis:
Thermal errors caused by the influence of internal and external heat sources in machine tool structure can cause up to 70% of total machine tool inaccuracy. Therefore, research on thermal behavior of machine tool structures is crucial for successful manufacturing. This paper provides an insight into the modeling of highly nonlinear (increasing with the complexity of the structure) machine tool thermal behavior using thermal transfer functions This approach to modeling is dynamic (uses thermal history) and, due to its relative simplicity, it enables real-time calculations. The method uses very few additional gauges and solves separately each influence participating in the thermal error. The main objective of the article is to describe the estimation of angular deformations occurring at the tool center point due to thermal influences. Transfer functions are used for the identification and control of additional internal heat sources. The second aim is to compare modeling effort with approximation quality. A partial objective is to cover other nonlinearities occurring generally in machine tool thermal behavior. The approach has been verified on a closed quill (a simple and symmetrical machine tool part) and applied on a model of a machine tool structure which has been chosen as the least favorable from the thermal point of view.
Źródło:
Journal of Machine Engineering; 2011, 11, 4; 78-90
1895-7595
2391-8071
Pojawia się w:
Journal of Machine Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Model-based, experimental thermoelastic analysis of a large scale turbine housing
Autorzy:
Emonts, Dominik
Sanders, Mark P.
Montavon, Benjamin
Schmitt, Robert H.
Powiązania:
https://bibliotekanauki.pl/articles/2052191.pdf
Data publikacji:
2022
Wydawca:
Wrocławska Rada Federacji Stowarzyszeń Naukowo-Technicznych
Tematy:
thermal error modelling
large scale metrology
virtual climatisation
Opis:
Temporally and spatially unstable thermal conditions lead to inhomogeneous thermoelastic changes in the workpiece geometry. Consequently, non-negligible geometric deviations are evident, especially when measuring large workpieces with narrow tolerances, which often take place in non-climatized production environments and thus make thermal monitoring indispensable. Accurate determination of the thermoelastic behaviour for complex and large geometries is a challenging task with computationally effortful or less accurate existing solutions. Thus, the development of innovative measurement and modelling approaches is subject of current research, whereat physical validation is a prerequisite. Therefore, the authors developed a method, enabling the emulation of typical process heat cycles on a turbine housing in combination with a geometric measurement system. The idea is to provide reproducible and reversible thermal conditions on a representative large workpiece and to investigate the resulting geometric deformation in an economically viable way. Throughout this study, an analogy test rig is presented, integrating different temperature sensors, two geometric measurement systems and thermal deformation models into one demonstrator. The demonstrator's first applications show insightful results, revealing accordance, but also unexpected deviations between the predicted and measured quantities. Moreover, it provides great potential for validation of more complex modelling approaches and innovative thermal condition monitoring systems for large precision workpieces.
Źródło:
Journal of Machine Engineering; 2022, 22, 1; 84-95
1895-7595
2391-8071
Pojawia się w:
Journal of Machine Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Implementation and demonstration of characteristic diagram as well as structure model based correction of thermo-elastic tool center point displacements
Autorzy:
Putz, M.
Ihlenfeldt, S.
Kauschinger, B.
Naumann, C.
Thiem, X.
Riedel, M.
Powiązania:
https://bibliotekanauki.pl/articles/99680.pdf
Data publikacji:
2016
Wydawca:
Wrocławska Rada Federacji Stowarzyszeń Naukowo-Technicznych
Tematy:
hexapod
characteristic diagram
thermal error
simulated
measured
correction algorithm
Opis:
In milling machines, waste heat from motors, friction effects on guides and most importantly the milling process itself greatly affect positioning accuracy and thus production quality. Therefore, active cooling and lead time are used to reach thermal stability. A cheaper and more energy-efficient approach is to gather sensor data from the machine tool to predict and correct the resulting tool center point displacement. Two such approaches are the characteristic diagram based and the structure model based correction algorithms which are briefly introduced in this paper. Both principles have never been directly compared on the same demonstration machine, under the equal environmental conditions and with the same measurement setup. The paper accomplishes this comparison ona hexapod kinematics examined in a thermal chamber,where the effectiveness of both approaches is measured and the strengths and weaknesses of both are pointed out.
Źródło:
Journal of Machine Engineering; 2016, 16, 3; 88-101
1895-7595
2391-8071
Pojawia się w:
Journal of Machine Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Supervising and compensation of thermal error of CNC feed ball screw
Nadzorowanie termiczne oraz kompensacja błędów odkształceń cieplnych śrub pociągowych obrabiarek CNC
Autorzy:
Pajor, M.
Zapłata, J.
Powiązania:
https://bibliotekanauki.pl/articles/329402.pdf
Data publikacji:
2013
Wydawca:
Polska Akademia Nauk. Polskie Towarzystwo Diagnostyki Technicznej PAN
Tematy:
thermal error
feed screw
monitoring
odkształcenia cieplne
śruba pociągowa
Opis:
The paper presents a set allowing for on-line monitoring of machine tool feed screw temperature. Indirect supervising of the feed screw thermal elongation protects ball bearings from excessive loads. Moreover, the usage of an appropriate model in the control system of the CNC machine tool allows for the reduction of ball screw thermal errors.
Prezentowany w pracy układ pozwala na monitorowanie „on-line” temperatury śruby pociągowej obrabiarki. Pośredni nadzór wydłużenia cieplnego śruby zabezpiecza przed nadmiernym obciążeniem łożysk tocznych na skutek wydłużenia cieplnego śruby pociągowej. Dodatkowo zastosowanie odpowiedniego modelu w systemie sterowania obrabiarki CNC pozwala na redukcję „on-line” błędów pozycjonowania wynikających z odkształceń cieplnych śrub pociągowych obrabiarki.
Źródło:
Diagnostyka; 2013, 14, 2; 37-42
1641-6414
2449-5220
Pojawia się w:
Diagnostyka
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
An investigation of the relationship between encoder difference and thermo-elastic machine tool deformation
Autorzy:
Brecher, Christian
Dehn, Mathias
Neus, Stephan
Powiązania:
https://bibliotekanauki.pl/articles/24084708.pdf
Data publikacji:
2023
Wydawca:
Wrocławska Rada Federacji Stowarzyszeń Naukowo-Technicznych
Tematy:
machine tool
thermal error compensation
machine learning
artificial neural network
Opis:
New approaches, using machine learning to model the thermo-elastic machine tool error, often rely on machine internal data, like axis speed or axis position as input data, which have a delayed relation to the thermo-elastic error. Since there is no direct relation to the thermo-elastic error, this can lead to an increased computation inaccuracy of the model or the need for expensive sensor equipment for additional input data. The encoder difference is easy to obtain and has a direct relationship with the thermo-elastic error and therefore has a high potential to improve the accuracy thermo-elastic error models. This paper first investigates causes of the encoder difference and its relationship with the thermo-elastic error. Afterwards, the model is presented, which uses the encoder difference to compute the thermo-elastic error. Due to the complexity of the relationship, it is necessary, to use a machine learning approach for this. To conclude, the potential of the encoder difference as an input of the model is evaluated.
Źródło:
Journal of Machine Engineering; 2023, 23, 3; 26--37
1895-7595
2391-8071
Pojawia się w:
Journal of Machine Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Application of machine learning in the precise and cost-effective self-compensation of the thermal errors of CNC machine tools – a review
Autorzy:
Czwartosz, Robert
Jedrzejewski, Jerzy
Powiązania:
https://bibliotekanauki.pl/articles/2142358.pdf
Data publikacji:
2022
Wydawca:
Wrocławska Rada Federacji Stowarzyszeń Naukowo-Technicznych
Tematy:
CNC machine tool
thermal error compensation
machine learning
self-learning
Opis:
The current development of production engineering takes place through the innovative improvement of machine tools and machining processes at the constantly growing application of intelligent self-improvement functions. Machine learning opens up possibilities for machine tool self-improvement in real time. This paper discusses the state of knowledge relating to the application of machine learning for precise and cost-effective thermal error self-compensation. Data acquisition and processing, models and model learning and self-learning methods are also considered. Three highly effective error compensation systems (supported with machine learning) are analysed and conclusions and recommendations for future research are formulated.
Źródło:
Journal of Machine Engineering; 2022, 22, 3; 59--77
1895-7595
2391-8071
Pojawia się w:
Journal of Machine Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł

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