Wyniki wyszukiwania - Biblioteka Nauki

1

Opracowanie metody pomiarów przemieszczeń względnych narzędzia i przedmiotu obrabianego podczas toczenia

100%

Skrzyniarz M. , Nowakowski Ł. , Miko E.

Mechanik

|

2015

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tom R. 88, nr 8-9CD2

577--585

PL

Przedstawiono dotychczasowe stanowiska badawcze służące do pomiaru przemieszczeń narzędzia i przedmiotu obrabianego w trakcie procesu toczenia. Omówiono główne wady tych stanowisk i zaprezentowano autorskie stanowisko do pomiarów przemieszczeń względnych w układzie „narzędzie – przedmiot obrabiany” podczas toczenia.

EN

The hitherto existing test rigs for measurement of displacements of the tool and the workpiece in the process of turning have been presented. The main disadvantages of these rigs were discussed and an original test rig for measurement of relative displacements in the “tool – workpiece” system during turning was presented.

2

Determining the emissivity at the tool-chip interface during S235JR steel turning

100%

Molenda J. , Charchalis A.

Journal of KONES

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2015

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tom Vol. 22, No. 2

149--154

EN

Temperature on the chip-tool interface is important parameters in the analysis and control of turning process. Due to the high shear and friction, energies dissipated during a machining operation the temperature in the primary and secondary shear zones are usually very high; hence, affect the shear deformation and tool wear. In a single point cutting, heat is generated at three different zones i.e. primary shear zone, chip tool interface and the tool-workpiece interface. The primary shear zone temperature affects the mechanical properties of the work piece – chip material and temperatures at tool-chip and tool-work piece interfaces influence tool wear at tool face and flank respectively. Total tool wear rate and crater wear on the rake face are strongly influenced by the temperature at chip-tool interface. Therefore, it is desirable to determine the temperatures of the tool and chip interface to analyse or control the process. To measure the temperature at the tool-chip interface many experimental methods have been developed over the past century. Since at the interface there is a moving contact between the tool and chip in this work, authors propose infrared method for temperature measuring. To assure possibly high accurate of noncontact temperature measurement there is a need to keep in mind several factors, including determining appropriate value of emissivity. In this work, authors present results of experimental determining emissivity value of tool-chip interface. As initial value, emissivity of polished steel was taken.

3

Chropowatość powierzchni po przecinaniu stali na tokarce nożem typu NNPb

100%

Wieczorowski K. , Tomkowiak P.

Zeszyty Naukowe Politechniki Poznańskiej. Mechanika

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2003

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tom Nr 49

77-88

PL

W artykule przedstawiono wyniki badań chropowatości powierzchni prętów stalowych przecinanych na tokarce nożem NNPb. W procesie technologicznym dużej liczby przedmiotów osiowo-symetrycznych o średnicach nawet do 100 mm istotną operację stanowi odcięcie wykonanego fragmentu lub gotowego wyrobu od pręta zamocowanego w uchwycie tokarki. Z uwagi na poszerzenie powstającego wióra odcinanie przedmiotu stanowi istotne zagrożenie dla chropowatości powierzchni odcinanych. Z uwagi na niewłaściwą chropowatość tych powierzchni znaczna liczba wyrobów osiowo-symetrycznych wymaga dodatkowej obróbki powierzchni po odcięciu. Określono współczynnik poszerzenia wióra w funkcji prędkości skrawania i kształt powierzchni natarcia ostrza noża wpływający na zmianę przekroju poprzecznego wióra. Pokazano strukturę powierzchni po przecinaniu ostrzem noża o płaskiej i specjalnie ukształtowanej powierzchni natarcia. Wskazano możliwości wyeliminowania uszkodzenia warstwy wierzchniej przez zmianę stereometrii ostrza noża przecinaka.

EN

The results of research of roughness after cut-off operation on the turning machine with using cutter type NNPb have been presented in the paper. Cut-off operation is often essential operation in the technological process of manufacturing of axial symetrical machine parts with diameters even to o 100 mm. It is the operation of cutting off of made fragment or of ready article from the shaft fixtured in lathe chuc. The essential problem of this operation can be so big roughness of machined surface because of chip widening. Regarding inappropriate surface roughness considerable number of axial symmetrical machine parts must be additionally machined after cut-off operation. Coefficient of chip widening versus the cutting speed has been determined. The shape of rake face of cutter edge influencing on the change of chip lateral section has been elaborated. The structure of surface after cut-off operation with using cutter with flat rake face and with special shapped rake face has been shown. The possibilities of elimination of surface layer damage on the way of cutter edge stereometry changes have been indicated.

4

Geometrical structure of surface after turning of 316L stainless steel in laser assisted conditions

100%

Szymański M. , Kukliński M.

Archives of Mechanical Technology and Materials

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2019

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tom Vol. 39

66--73

EN

The effects of turning 316L steel in a laser assisted machining are presented in this paper. The properties of 316L stainless steel are also shown in this article. In order to show correlation between the technological parameters, microgeometry of cutting tools and geometrical structure of surface, turning of material in grade 316L supported by laser has been executed. In addition, optical examination of cutting inserts has been performed and geometrical measurements of machined surfaces have been taken. The results of researches on the effects of the technological parameters and cutting tool's microgeometry on the geometrical structure of the 316L steel surface after turning in LAM conditions are described.

5

Toczenie obracaną płytką skrawającą

100%

Szafarczyk M.

Mechanik

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2010

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tom R. 83, nr 12

954-954

6

The application of planing tools during turning

100%

Tomczewski L.

Advances in Science and Technology. Research Journal

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2015

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tom Vol. 9, nr 27

83--86

EN

The articles presents the possibility of using CNC turning centers for planing. Through the application of specialized planingtools, it is possible to avoid the use of additional mills during the machining process. The implementation of these tools avoids dimensional and geometrical deviations resulting for remounting the work piece in different machines, while also saving time.

7

The influence of the conditions of emulsion mist formation on the surface roughness of AISI 1045 steel after finish turning

100%

Feldshtein E. , Józwik J. , Legutko S.

Advances in Science and Technology. Research Journal

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2016

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tom Vol. 10, nr 30

144--149

EN

The processes of machining have vital influence on the operating properties of machine parts because they ensure the formation of the required geometrical structure of the working surfaces and the condition of the top layer. In this paper the influence of emulsion mist parameters on Ra, Rz and RSm surface roughness parameters is described when finishing the turning of C45 carbon steel. It was found that cutting parameters have considerably greater influence on roughness parameters in comparison with emulsion mist conditions. When increasing cutting speed from 100 to 300 m/min Ra and Rz values decrease nearly 2 times, but RSm value does not depend on speed. When increasing feed rate from 0.1 to 0.2 mm/rev Ra, Rz and RSm values increase more than twice. Changes of emulsion mass flow and compressed air flow affect roughness parameters reach 9–15% of maximum. It was shown that Parameter Space Investigation method can be used efficiently for quick analysis of tested parameters and optimization of their values.

8

Numerical Simulation Studies on the Process of Machining of Shafts with Low Rigidity

100%

Świć A. , Gola A.

Applied Computer Science

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2016

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tom Vol. 12, no 2

42--53

EN

The paper presents a computer program developed for the determination of the basic dynamic characteristics of the process of machining, numerical simulations of the dynamic system of the process of machining, and graphic presentations of the numerical simulations performed. Results of simulations of the runs of time and frequency characteristics of the process of machining with variable machining parameters are presented. High goodness-of-fit of the model with the actual process of turning was achieved.

9

Analiza doświadczalna zjawiska narostu podczas toczenia

100%

Jóźwik J. , Domińczuk J.

Eksploatacja i Niezawodność

|

2001

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tom nr 5

53-57

PL

W artykule przedstawiono wyniki badań zjawiska narostu, przeprowadzonych w Katedrze Podstaw Inżynierii Produkcji Politechniki Lubelskiej. Charakterystyczne wielkości geometrycznych tworzonego narostu analizowano przy zastosowaniu systemu do cyfrowej analizy obrazu MICROSCAN. W postaci obrazów wizyjnych oraz wykresów przedstawiono charakter zmian wybranych parametrów geometrycznych powstającego narostu oraz uzyskane wartości parametrów chropowatości powierzchni po obróbce.

EN

The results of built-up edge effect researches, effected in Department of Production Engineering Principles at Lublin Institute of Technology are presented in this article. Characteristic geometrical sizes of arisen built-up edge were subject to analysis with usage of MICRO SCAN, digital analysis system of picture. The character of changes of selected geometric parameters of arising built-up edge and obtained values of surface roughness parameters after machining are shown in form of visional pictures and graphs.

10

Analytical time-domain model for tool point dynamics in turning

100%

Berglind L. , Ziegert J.

Journal of Machine Engineering

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2014

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tom Vol. 14, No. 4

75--94

EN

An analytical time domain solution is developed to model the dynamic response of a tool during a simple turning operation. The time domain solution developed in this paper relies on the superposition principal under the linear assumption to construct the time response of single mode, single degree of freedom cutting tool. The results from the analytical solution are compared with those generated using numerical time domain simulations and it is found that the two solutions converge as the time step used in the numerical simulation decreases.

11

Zużycie ostrza narzędzia, a zmiana parametrów toczenia w kolejnych zabiegach

100%

Wartacz A. , Świć A. , Zubrzycki J.

Eksploatacja i Niezawodność

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2004

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tom nr 4

58-61

PL

W artykule przedstawiono krótki przegląd podstaw teoretycznych zużycia narzędzi skrawających oraz wybrane wyniki badań wstępnych zużycia ostrza narzędzia w aspekcie zmian parametrów toczenia w kolejnych zabiegach.

EN

In article was introduced the short review of theoretical bases' of cutting tools waste and the chosen results of preliminary investigation of waste blade tool in aspect of turning parameters changes in next cuts.

12

Material identification during turning by neural network

100%

Denkena B. , Bergmann B. , Handrup M. , Witt M.

Journal of Machine Engineering

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2020

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tom Vol. 20, No. 2

65--76

EN

A design concept for high-performance components involves the combination of different materials in hybrid workpieces. Different material properties and chemical compositions influence the machining quality of hybrid workpieces. To achieve a constant workpiece and process quality, it is necessary to adjust the process parameters to the individual material. Thus, it is mandatory to classify the material during machining for the relevant range of process parameters. This paper examines teaching strategies for neural networks to determine the machined material in process by a small amount of cross points. For this purpose, different training sets are compared. Process parameters with different cutting speeds, feeds and with constant and varying depth of cut are examined. In addition, the signal sources necessary for robust material classification are compared and investigated. The investigation is performed for the cylindrical turning of friction welded EN AW-6082/20MnCr5 shafts. The study shows that an F1 score of 0.99 is achieved at a constant cutting depth, provided that only the corner points of the process window and the machine control signals are used for training. With an additional variation of the cutting depth, the classification rate is significantly improved by the use of external sensors such as the acceleration sensor.

13

Modelling of Characteristics of Turning of Shafts with Low Rigidity

100%

Świć A. , Gola A. , Hajduk M.

Applied Computer Science

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2016

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tom Vol. 12, no 3

61--73

EN

Numerical studies were conducted with the use of a computer program permitting the determination of the basic dynamic characteristics of the process of machining and the presentation of graphic characteristics of the numerical simulations performed. Analysis was performed of the relation of the output parameters of the dynamic system to the input parameters, relative stiffness coefficient B to feed rate and depth of machining, change of retardation and time constants to rotary speed and depth of machining, and of the frequency and time characteristics of models of the dynamic system of machining of shafts with low rigidity.

14

The theory of similarity in turning operations

100%

Rząsiński R.

Journal of Achievements in Materials and Manufacturing Engineering

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2012

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tom Vol. 53, nr 1

37--46

EN

Purpose: The article presents the development of series of types of technology issues. This is an accomplished using of the innovative technological similarity theory. The transformation presented in the theory relates to the turning machining processes. Design/methodology/approach: The data generation process is concerned with the creation of the conditions and number similarities. The turning condition of similarity results from the cutting power, cutting forces and cutting performance. Findings: The development of the theory of similarity allows the generation of machining parameters for the series of types of construction (blank, machining parameters, tools). Research limitations/implications: The analyzed methods develop the algorithmisation of engineers and technologists environment and support the integration with the process of preparation of the production. Practical implications: The described methods were being developed on the practical examples of the creating of the series of types of the hydraulic cylinders used in mining. Originality/value: The method of the technological similarity presented in the paper is the basis of the selection of technological features in the process of series of types and module systems of constructions and technology creating.

15

Integrated CAM for SolidWorks

100%

Dickin P.

Advanced Technologies in Mechanics

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2015

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tom Vol. 2, no. 2 (3)

41--45

EN

A series of improvements of the Delcam for SolidWorks integrated CAM system has been presented.

16

Development of Key Competencies in Integrated Teaching Workplaces

100%

Kučerka D.

Acta Technologica Dubnicae

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2016

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tom 6

|

nr 1

49-56

EN

This article deals with the determination and definition of competencies of pupils and their development in an integrated didactic work place. The article focuses on the practical teaching in the turning workshop at secondary school. The development of competencies is based on the learning objectives for the subject “Technology of Turning” in the practical teaching. The general learning objectives are further specified in sub-objectives, in which the various competencies the student should acquire and develop are defined.

17

On line wear monitoring in turnint

100%

Ghasempoor A. , Moore T. N. , Jeswiet J.

Prace Naukowe Instytutu Technologii Maszyn i Automatyzacji Politechniki Wrocławskiej. Konferencje

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1998

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tom Vol. 69, nr 31

173-182

EN

On line wear detection in turning operation is consideration in this paper. A wear monitoring system based on hierarchical neural networks in suggested for this purpose. The changes in cutting force components are used for monitoring three wear components. The hierarchical neural network structure uses multilayered, feedforward, static and dynamic neural networks as specialized subsystem for each wear component to be monitored. Simulation studies are performed to investigate the overall suitability of the system.

PL

Praca podejmuje zagadnienie nadzoru zużycia w czasie rzeczywistym w operacjach skrawania. Przedstawiono koncepcję odpowiedniego układu nadzorującego w postaci hierarchicznej sieci neuronowej. Zmiany składowych sił skrawania są podstawą do oceny trzech składowych zużycia. W strukturze sieci hierarchicznej można wyróżnić wielowarstwowe sieci statyczne i dynamiczne służące jako wyspecjalizowane podukłady do monitorowania poszczególnych składowych zużycia. Przytoczono wyniki badań symulacyjnych, które miały za zadanie ocenić przydatność proponowanego układu.

18

Faculty Of Mechanical Engineering, University of Ljubljana, Slovenia

100%

Gradisek J. , Govekar E. , Grabec I.

Prace Naukowe Instytutu Technologii Maszyn i Automatyzacji Politechniki Wrocławskiej. Konferencje

|

1998

|

tom Vol. 69, nr 31

163-172

EN

A method for chatter detection in turning is presented. It utilizes significant differences in dynamics of chatter - free cutting and chatter. Experimentally, chatter was achieved by a change of the cutting depth. The measured time series of cutting forces were characterized by the coarse - grained entropy rate. A high value of the entropy rate is typical of chatter - free cutting, while a low value is typical of chatter. For the purpose of chatter detection, the normalized entropy rate is used and a characteristic threshold is defined. The value of the threshold is independent of cutting conditions.

PL

Przedstawiono nową metodę detekcji drgań narzędzia w skrawaniu. Podstawą metody są duże różnice w dynamice procesu skrawania zależne od tego czy towarzyszą mu, czy też nie, drgania. Niekorzystną dynamikę procesu osiągano przez zmianę głębokości skrawania. Zmierzone szeregi czasowe sił skrawania opisano zmianą entropii. Duża prędkość zmiany entropii jest typowa dla skrawania bezdrganiowego, z drganiami narzędzia natomiast wiąże się mała prędkość zmian entropii. Na potrzeby detekcji wprowadzono prędkość znormalizowaną entropii i zdefiniowano jej wartość progową. Stwierdzono, że wartość progowa nie zależy od warunków skrawania.

19

Obróbka wielokątów foremnych metodą toczenia

100%

Kowalski T. , Niedbała M. , Soporek M.

Technologia i Automatyzacja Montażu

|

2008

|

tom nr 4

30-32

EN

Characterization of a precise VENUS 200GW turning machine allowing turning of a polygon shapes. Examples of a turning technological processes to obtain hexagonal shapes. Advantages of such a cutting method.

20

Using thermovision for machining processes inspection

100%

Molenda J. , Charchalis A.

Journal of KONES

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2016

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tom Vol. 23, No. 3

345--350

EN

During metal cutting process, an increase of the tool and workpiece temperatures can be observed. The heat generated has a negative influence on the tool life and performance. It causes rapid tool wear, plastic deformation of the cutting edge, built-up-edge formation and others. Therefore, the control of cutting temperature is required to achieve the desired tool performance. Temperature is the most frequently measured physical quantity, second only to time. Accurate temperature monitoring improves product quality and increases productivity. Downtimes are decreased, since the manufacturing processes can proceed without interruption and under optimal conditions. In this work, authors propose noncontact infrared method for determining temperature of machining processes. This was mainly due to thermography ability to catching moving targets in real time, to measure temperatures over some area not only in point. As a result of measurement, it is obtained a data set that is presented in a form of a colourful map: a thermogram. Getting an accurate temperature of an object using this method is difficult because of numerous errors, which researchers could done during experiments. This work presents some results of research done during turning and drilling realized on conventional lathe CDS 6250 BX-1000. These demonstrate the usefulness of proposed method to study the machining processes temperature.