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1

Analysis of thermal characteristics with multi-physicsc oupling for the feed system of a precision CNC machine tool

Zheng Junjian, Deng Xiaolei, Yang Junshou, Zhang Wanjun, Lin Xiaoliang, Jiang Shaofei, Yao Xinhua, Shen Hongchen

Bulletin of the Polish Academy of Sciences. Technical Sciences

|

2024

|

Vol. 72, nr 2

art. no. e148941

EN

The machining accuracy of CNC machine tools is significantly affected by the thermal deformation of the feed system. The ball screw feed system is extensively used as a transmission component in precise CNC machine tools, responsible for converting rotational motion into linear motion or converting torque into repetitive axial force. This study presents a multi-physical coupling analysis model for the ball screw feed system, considering internal thermal generation, intending to reduce the influence of screw-induced thermal deformation on machining accuracy. This model utilizes the Fourier thermal conduction law and the principle of energy conservation. By performing calculations, the thermal source and thermal transfer coefficient of the ball screw feed system are determined. Moreover, the thermal characteristics of the ball screw feed system are effectively analyzed through the utilization of finite element analysis. To validate the proposed analysis model for the ball screw feed system, a dedicated test platform is designed and constructed specifically to investigate the thermal characteristics of the ball screw feed system in CNC machine tools. By selecting specific CNC machine tools as the subjects of investigation, a comprehensive study is conducted on the thermal characteristics of the ball screw feed system. The analysis entails evaluating parameters like temperature field distribution, thermal deformation, thermal stress, and thermal equilibrium state of the ball screw feed system. By comparing the simulation results from the analysis model with the experimental test results, the study yields the following findings: The maximum absolute error between the simulated and experimental temperatures at each measuring point of the feed system components is 2.4◦C, with a maximum relative error of 8.7%. The maximum absolute error between the simulated and experimental temperatures at the measuring point on the lead screw is 2.0◦C, with a maximum relative error of 6.8%. The thermal characteristics obtained from the steady-state thermal analysis model of the feed system exhibit a prominent level of agreement with the experimental results. The research outcomes presented in this paper provide valuable insights for the development of ball screw feed systems and offer guidance for the thermal design of machine tools.

2

Software-defined workpiece positioning for resource-optimized machine tool utilization

Ströbel Robin, Probst Yannik, Hutt Louisa, Fleischer Jürgen

Journal of Machine Engineering

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2023

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Vol. 23, No. 1

71--84

EN

Advancing climate change, tense world markets, and political pressure steadily increase the demand for resource-optimized production solutions. Herby, the positioning of the raw material in the machine tool is an important factor that has received little attention. Traditionally, this is done centrally on the machine table, which leads to locally increased wear of the feed axis. Furthermore, positioning directly influences energy consumption during machining. Consequently, the longest possible component utilization through optimum wear and energy optimization creates a direct conflict of objectives. To solve this conflict, this paper presents an automated approach for software-defined workpiece positioning and NC-Code optimization regarding the axis-specific energy consumption and the spindle condition of ball screws. An approach for mapping the energy consumption and the directly measured spindle condition is presented. Both represent input variables of the cost function. Approaches for the optimization of the position as well as for the practical implementation are proposed.

3

Key fault propagation path identification of CNC machine tools based on maximum occurrence probability

Zhang Yingzhi, Zhou Yutong, Yang Fang, Wang Zhiqiong, Sun Mo

Eksploatacja i Niezawodność

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2023

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Vol. 25, no. 3

art. no. 169887

EN

In order to revise the deviation caused by ignoring the dynamic character of fault propagation in traditional fault propagation path identification methods, a method based on the maximum occurrence probability is proposed to identify the key fault propagation path. Occurrence probability of fault propagation path is defined by dynamic importance, dynamic fault propagation probability and fault rate. Taking the fault information of CNC machine tools whichsubject to Weibull distribution as an example, this method has been proven to be reasonable through comparative analysis. Result shows that the key fault propagation path of CNC machine tools is not unique, but changes with time. Before 1000 hours, key fault propagation path is electrical component (E) to mechanical component (M); after 1000 hours, key fault propagation path is auxiliary component (A) to mechanical component (M). This change should be taken into account when developing maintenance strategies and conducting reliability analysis.

4

Surface Texturing on a CNC Machine Tool Using a Laser

Józwik Jerzy, Dziedzic Krzysztof

Advances in Science and Technology. Research Journal

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2023

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Vol. 17, no 1

160--172

EN

In the paper stages of the process of constituting a surface with the texture of the injection mold of a wheeled vehicle steering wheel using laser technology was discusses. During micromachining process with texturing there is a 5-axis CNC-controlled CNC machine TOOL LASERTEC 65 Shape used with a rigid monoBLOCK structure with Siemens 840D sl control, equipped with a fiber laser with a power of 100W, a wavelength of 1064 nm and a focal length of 181 mm. Processing technology was prepared using Autodesk Maya, Adobe Photoshop, Adobe Illustrator, NX9, Lastex v. 2.27.26 computer programs and machine tool control systems. Results of machining the steering wheel of a wheeled vehicle with a concentrated laser beam are discussed. Geometric structure of the surface after texturing was evaluated. Presented technology can be used to obtain the desired texture properties on the surface of the parts.

5

Application of machine learning in the precise and cost-effective self-compensation of the thermal errors of CNC machine tools – a review

Czwartosz Robert, Jedrzejewski Jerzy

Journal of Machine Engineering

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2022

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Vol. 22, No. 3

59--77

EN

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.

6

Dynamic Analysis of the Starting and Braking of the Table of CNC Machine Tool

Józwik Jerzy, Zawada-Michałowska Magdalena, Moń Damian

Advances in Science and Technology. Research Journal

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2022

|

Vol. 16, no 3

34--46

EN

The aim of the paper is a dynamic analysis of the starting and braking of the table of a numerically controlled CNC machine tool during idle motion. The experimental test was performed on the vertical table of the FV580A machining centre using the Phantom v1610 high-speed vision camera. The dynamics characteristics of the table movement were registered and the dynamics estimates of the movement were determined. The influence estimation of the parameters of the machine tool table motion on the value of the determined estimates was made. The results of measurements were discussed and guidelines and in order to minimise disturbances were formulated. The test results were summarised and discussed in the form of charts and tables. The directions of further research in the discussed subject area were also defined

7

Zwiększenie wydajności kontroli ruchu układów bramowych z dwuosiowymi napędami COPLEY Plus

Crumlish Dean

Napędy i Sterowanie

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2020

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R. 22, nr 2

10--11

PL

Osie połączone w układ bramowy, czyli takie, w których ruch jednej osi liniowej napędzany jest dwoma silnikami, odgrywają ważną rolę w różnych zastosowaniach, takich jak plotery frezujące i obrabiarki CNC, montaż, aplikacje pick-and-place i wiele innych. Wymagają one ścisłej koordynacji ruchu obu silników. Nawet małe rozbieżności we współbieżnym przemieszczaniu bramy przez silniki mogą powodować opory ruchu oraz naprężenia mechaniczne układu zmniejszające dokładność. Skutkując nierównomiernym ruchem, prowadzącym nawet do całkowitego zatrzymania bramy. Wyspecjalizowane napędy z wbudowanymi funkcjami kontroli ruchu układów bramowych mogą zapobiegać tym problemom przy jednoczesnym usprawnieniu procesu projektowania i uruchamiania układów wieloosiowych.

8

The use of new technology to improve the quality of production on a CNC machine tool

Gołębski Rafał, Sikora Piotr, Gnatowski Adam

System Safety : Human - Technical Facility - Environment

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2019

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Vol. 1, nr 1

583--590

EN

The article presents an analysis of the modification of the production process on a CNC machine tool. The process was modified by using a new deep hole drilling procedure. As a consequence, an improvement in the quality of manufactured elements in series production has been achieved. The applications were supported by metrological analysis of the product.

9

Podstawowe charakterystyki sensorów

Skoczyński Wacław

Napędy i Sterowanie

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2019

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R. 21, nr 6

96--105

PL

Systemy pomiarowe w urządzeniach wytwórczych wykorzystują różne czujniki i elementy wykonawcze do pomiaru i manipulowania układami mechanicznymi. Czujniki mają wiele cech, które wpływają na ich możliwości pomiarowe oraz ich przydatność dla konkretnej aplikacji. W czujnikach analogowych każdej wartości z zakresu zmian mierzonego parametru odpowiada określony sygnał wyjściowy, zmieniający się w sposób ciągły w zależności od zmian parametru wejściowego. Przykładem czujników analogowych są potencjometry, transformatorowe czujniki przemieszczeń liniowych o układzie różnicowym LVDT (ang. Linear Variable Differential Transformer) z przesuwanym rdzeniem, piezoelektryczne przetworniki siły i termistory.

10

50 lat obrabiarek firmy HURCO(R). 50 lat innowacji

Świat Obrabiarek i Narzędzi

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2018

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R. 13, nr 9-10

12--13

11

A Comparative Analysis of the Impact of CNC Miller Programming on Machining Effects

Kuczmaszewski J., Pieśko P., Zawada-Michałowska M.

Multidisciplinary Aspects of Production Engineering

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2018

|

Vol. 1, Iss. 1

161--167

EN

This paper presents a comparison of the impact of the programming methods of a CNC miller on the machining effects. As a part of the study, the test samples were made of the EN AW-2024 aluminium alloy. The CNC machining programs compared were developed with two programming methods: by inputting the CNC machining program directly from the CNC miller's control panel (machine level programming) and in a CAM software environment (CAM programming). The machining effect indicators adopted included: machining time, surface quality, and dimensional deviation of specific geometrical features. A measurement of the machining times revealed than the CAM programming reduced the machining time up to 20% from the machining time of the machine level programming. A conclusion stands valid that CNC machining programs developed in the CAM software environment are more efficient than CNC programming directly with the CNC miller control panel, most likely due to the machining path optimisation in CAM. In addition, given the experimental test results, it was found that smaller machined errors were also obtained for CAM programming. To conclude, the comparative analysis revealed that CAM programming provided better machining results than the machine level programming.

12

Wytwarzanie przyrostowe za pomocą maszyn HURCO (R)

Świat Obrabiarek i Narzędzi

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2017

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R. 12, nr 5-6

13

Comparative occupational risk assessment in a CNC machine tool operator position

Pacana A.

Production Engineering Archives

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2017

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Vol. 16

28--31

EN

Law requires from employers to assess occupational risk in workplaces. A well-executed occupational risk assessment promotes the improvement of working conditions and reduces a negative impacts on employees’ health and life. Employers by conducting occupational risk assessment not only meet legal requirements but also benefit from it in two ways. They eliminate loss of an enterprise connected with employees’ absence, and they also decrease the probability of high compensation pay due to situations that have a destructive influence on the employees' health. However, in order to benefit from such actions, firstly, it is necessary to select a risk assessment method properly, then to apply it and implement preventive measures. The paper presents the results of the occupational risk assessment carried out on the example of a CNC machine operator by means three-stage methods in accordance with the PN-N-18001, PHA and Risc Score. Despite the subjectivity of the assessment, there were differences in the results. Thus, it is advisable to choose a risk assessment method skilfully, for example by comparing several similar methods.

14

Modelowanie odkształceń cieplnych obrabiarki precyzyjnej metodą MES

Zapłata J.

Modelowanie Inżynierskie

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2017

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T. 32, nr 63

114--122

PL

W artykule przedstawiono wyniki zamodelowanych, za pomocą metody elementów skończonych, odkształceń cieplnych frezarki CNC wynikające z pracy jej napędu głównego. Omówiono model cieplny obrabiarki, jej model mechaniczny oraz procedury umożliwiające obliczenie warunków granicznych dla wspomnianych modeli. Celem publikacji jest ukazanie wpływu, jaki wywierają poszczególne warunki brzegowe przyjmowane w toku modelowania na wyniki końcowe analiz odkształceń cieplnych. Proces szacowania poszczególnych warunków brzegowych jest czasochłonny, szczególnie w przypadku braku gotowych aplikacji umożliwiających ich obliczenie. Ponadto wymaga on często specjalistycznej wiedzy. Dlatego możliwość pominięcia niektórych zjawisk lub dopuszczenia większego marginesu błędu ich oszacowania, bez znaczącego pływu na wyniki końcowe analizy, jest korzystna dla konstruktorów oceniających wartości odkształceń cieplnych obrabiarek precyzyjnych za pomocą metody MES.

EN

The paper presents results of FEM analysis of CNC milling machine thermal error arising during its spindle work. The thermal and mechanical model were presented. Procedures allowing to estimate the border conditions were described. The paper aims to assess the influence of relevant border conditions on FEM analysis results. The process of evaluating the border conditions requires specific knowledge and is time-consuming, especially if no dedicated software is accessible. Therefore possibility to neglect insignificant phenomena or to widen allowed estimation error margin, without noticeably influencing analysis result, is valuable for designers evaluating thermal errors by means of FEM analysis.

15

Implementacja bezprzewodowego układu kompensacji odkształceń cieplnych osi posuwu w tokarce CNC ze śrubą toczną

Zapłata J., Pajor M., Stateczny K.

Modelowanie Inżynierskie

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2016

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T. 27, nr 58

145--151

PL

W artykule przedstawiono bezprzewodowy system kompensacji odkształceń cieplnych śrub pociągowych zaimplementowany w tokarce typu Avia Turn. Funkcjonowanie systemu opiera się na pomiarze rozkładów temperatur za pomocą czujników umieszczonych we wnętrzu śrub pociągowych. Wykorzystano czujniki z wbudowanym interfejsem cyfrowym. Dane, zawierające wartości temperatur, przesyłane są do układu PLC obrabiarki za pomocą energooszczędnego, bezprzewodowego interfejsu. Zastosowanie opracowanych procedur obliczeniowych pozwala określić wartość poprawki redukującej wpływ odkształceń cieplnych na dokładność pozycjonowania osi. Wartość ta jest zależna od pozycji oraz aktualnego stanu temperaturowego. W pracy przedstawiono zarejestrowane doświadczalnie temperatury, odchyłki położenia osi napędowych oraz obliczone poprawki potwierdzające skuteczność działania opracowanego systemu kompensacji.

EN

The paper presents a wireless set for compensation of the thermal error of CNC axes installed in “Avia Turn”. The set uses temperature sensors installed inside ball screws for measuring the thermal state of CNC axes. The sensors have build-in digital interfaces. Thermal data are sent to the PLC of a CNC lathe by means of an energyefficient wireless interface. The developed mathematical model allows to compute correction values reducing the influence of the positioning thermal error. The correction values are position- and temperature-dependent. The measured temperatures, positioning thermal errors and evaluated correction values have been shown validating the functionality of the set.

16

Frezowanie czołowe powierzchni walcowych

Rudaś T., Tymiński M.

Stal, Metale & Nowe Technologie

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2015

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nr 9-10

116--119

PL

Frezowanie toczne jest stosunkowo nowym sposobem obróbki łączącym w sobie cechy toczenia i frezowania, możliwym do realizacji na wieloosiowych obrabiarkach CNC. W artykule przedstawione zostały główne aspekty technologii czołowego frezowania tocznego oraz potencjalne obszary jej efektywnego zastosowania.

EN

Turn milling is a relatively new method of machining that combines both milling and turning techniques, which may be implemented in multi-axis CNC machines. The paper presents the main aspects of orthogonal turn milling technology, as well as potential areas for its effective application.

17

Analiza zmian poziomu ciśnienia akustycznego wrzeciona obrabiarki w strefie pracy operatora

Błasiak M., Mięsikowska M., Nowakowski Ł.

Mechanik

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2015

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R. 88, nr 8-9CD2

390--398

PL

Przedmiotem artykułu jest analiza zmian poziomu ciśnienia akustycznego w strefie prac operatora, które jest emitowane przez wrzeciono obrabiarki CNC pracujące bez obciążenia z różnymi prędkościami obrotowymi oraz podczas skrawania z prędkością 10 000 obr/min. Istotą przeprowadzonych badań było sprawdzenie, czy poziom hałasu emitowanego przez obrabiarkę CNC nie przekracza wartości dopuszczalnej. Wykonano je zgodnie z zapisem badania hałasu podanym w normie ISO 230-5 oraz z wykorzystaniem norm ISO 3744 i ISO 11203. Badania pokazały, że podczas głębszej obróbki materiału pojawiają się dźwięki o charakterze impulsowych. Poziom dźwięku wzrasta wówczas do wartości 92,2 dB, a więc na stanowisku pracy następuje przekroczenie dopuszczalnego poziomu dźwięku. Dla różnych prędkości obrabiarki poziom dźwięku A utrzymuje się na stałym poziomie: 71÷72 dB(A) – dla prędkości do 5000 obr/min, 80 dB(A) – dla wyższych prędkości.

EN

The subject of the study was to analyze sound pressure levels at the operator work area, emitted by a CNC machine tool working in different speeds of spindle and during process of cutting with a speed of 10,000 rev / min. The essence of the study was to find out if the noise level emitted by the CNC machine tool exceeds the acceptable sound level. The study was carried out according to the specified standards in documents ISO 230-5, ISO 3744 and ISO 11203 [set of standards]. Obtained results indicate the appearance of an impulse sound at a deeper treatment of the material-deeper cutting causes the appearance of impulse noise. Under such conditions, the sound level rises to the value of 92.2 dB, which indicates a sound level that exceeds the acceptable sound measure levels. A sound level for different speeds of the machine is maintained at a constant level row 71/72 dB(A) up to 5000 rev / min, and increases for higher speeds of the machine tool to the value of 80 dB(A).

18

Linear positioning errors of 3-axis machine tool

Józwik J., Mazurek P., Wieczorek M., Czwarnowski M

Applied Computer Science

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2015

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Vol. 11, no 2

86--94

EN

This paper presents results of 3-axis CNC machine tool diagnostics performed with XL-80 laser interferometer and XC-80 environmental compensation unit, including pressure, humidity and temperature sensors. Furthermore, the paper includes the methodology and results of conducted measurements of linear positioning errors, which supplied data for further analysis. The conclusion section presents important results of conducted experiments. Measurement results were presented in figures, charts and tables.

19

Diagnostic of CNC lathe with QC 20 ballbar system

Józwik J., Semotiuk L., Kuric I.

Advances in Science and Technology. Research Journal

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2015

|

Vol. 9, nr 28

96--102

EN

This paper presents the evaluation of the influence of the feedmotion speed on the value of selected geometric errors of CNC lathe CTX 310 eco by DMG, indentified by QC 20 Ballbar system. Diagnostically evaluated were: the deviation of the axis squareness, reversal spike, and backlash. These errors determine the forming of the dimensional and shape accuracy of a machine tool. The article discusses the process of the CNC diagnostic test, the diagnostic evaluation and formulates guidelines on further CNC operation. The results of measurements were presented in tables and diagrams.

20

Angular positioning accuracy of rotary table and repeatability of five-axis machining centre dmu 65 monoblock

Józwik J., Czwarnowski M

Advances in Science and Technology. Research Journal

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2015

|

Vol. 9, nr 28

89--95

EN

The study aims to evaluate angular positioning accuracy and repeatability of DMU 65 monoBLOCK numerically controlled machine tool. The measurements were carried out with XL-80 Laser Interferometer with XR20-W attachment. The measurements were conducted according to the standard PN-ISO230-2. Test methodology and measurement results analysis are presented in a form of figures and tables. The final part presents conclusions from the analysis.