Wyniki wyszukiwania - BazTech

1

Tool path planning for five-axis end milling of cycloidal gears and its full tooth profile accuracy measurement

Wang Jian, Liao Longxing, Luo Shanming, Mo Jingyu

Engineering Transactions

|

2023

|

Vol. 71, iss. 1

3--21

EN

This paper proposes a method of end milling of cycloidal gears using a five-axis computer analytical control (CNC) machine tool. Firstly, the basic principle of the five-axis end milling of cycloidal gears is introduced. The cutting characteristics of the ball-end and the flat-end cutters are analyzed. Secondly, the path planning method of the five-axis end milling of cycloidal gears is researched. A curvature matching method is used to check for local over-cut interference and a minimum distance method is used to check for global collision interference. These two interferences are avoided by calculating the feasible range of cutter orientations and adjusting the dips of cutter shafts. Tests of end milling of cycloidal gears are carried out using a ball-end cutter and a flat-end cutter, respectively. Finally, full tooth profile accuracy measurements are undertaken with an image-measuring instrument to assess the quality of cycloidal gears processed in this way. This study provides a theoretical basis for the improvement of the tooth profile accuracy and surface quality of cycloidal gears.

2

Experimental and Numerical Investigation of Cutting Forces and Temperatures in Milling of Custom 450 Steel

Gökçe Harun

Archives of Metallurgy and Materials

|

2022

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Vol. 67, iss. 3

843--853

EN

Stainless steels have a wide usage field, their needs as structural parts are increasing day by day due to their resistance to corrosion and providing sufficient mechanical strength in environments that would cause corrosion. In addition to high mechanical properties of the stainless steels, the low heat transmission coefficients bring problems during machining. In this study, the suitable cutting tool and cutting parameters have been evaluated in terms of cutting forces and the tool temperature, the experimental results and finite element analysis have been compared in the milling of Custom 450 stainless steel which offers especially an excellent working opportunity at high temperature and salinity environment. Milling experiments have been carried out using L16 experimental design for Taguchi method. Four simulations have been made using finite element method with corresponding values in L16 orthogonal array for optimum cutting tool and the results were compared in terms of cutting forces and tool temperature changes.

3

Modelowanie sił podczas frezowania walcowo-czołowego w oparciu o hybrydowy model numeryczno-analityczny

Madajewski M., Wojciechowski Sz., Znojkiewicz N., Twardowski P.

Mechanik

|

2018

|

R. 91, nr 8-9

757--759

PL

Przedstawiono sposób predykcji składowych siły całkowitej podczas obróbki frezem walcowo-czołowym w oparciu o metodę elementów skończonych (MES) i podejście analityczne. Model hybrydowy wyznacza wartości sił Ff i FfN, które porównano z wartościami doświadczalnymi z testów obejmujących pomiar sił w trakcie frezowania.

EN

Presented is method for prediction of cutting force components during end milling process by utilizing finite element analysis (FEA) combined with classical analytical approach. Hybrid model predicts Ff and FfN force components which are compared with empirical measurements from milling operation.

4

Optimization of Process Parameters During End Milling and Prediction of Work Piece Temperature Rise

Bhirud N. L., Gawande R. R.

Archive of Mechanical Engineering

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2017

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Vol. LXIV, nr 3

327--346

EN

During the machining processes, heat gets generated as a result of plastic deformation of metal and friction along the tool–chip and tool–work piece interface. In materials having high thermal conductivity, like aluminium alloys, large amount of this heat is absorbed by the work piece. This results in the rise in the temperature of the work piece, which may lead to dimensional inaccuracies, surface damage and deformation. So, it is needed to control rise in the temperature of the work piece. This paper focuses on the measurement, analysis and prediction of work piece temperature rise during the dry end milling operation of Al 6063. The control factors used for experimentation were number of flutes, spindle speed, depth of cut and feed rate. The Taguchi method was employed for the planning of experimentation and L18 orthogonal array was selected. The temperature rise of the work piece was measured with the help of K-type thermocouple embedded in the work piece. Signal to noise (S/N) ratio analysis was carried out using the lower-the-better quality characteristics. Depth of cut was identified as the most significant factor affecting the work piece temperature rise, followed by spindle speed. Analysis of variance (ANOVA) was employed to find out the significant parameters affecting the work piece temperature rise. ANOVA results were found to be in line with the S/N ratio analysis. Regression analysis was used for developing empirical equation of temperature rise. The temperature rise of the work piece was calculated using the regression equation and was found to be in good agreement with the measured values. Finally, confirmation tests were carried out to verify the results obtained. From the confirmation test it was found that the Taguchi method is an effective method to determine optimised parameters for minimization of work piece temperature.

5

Investigation of Temperature Distribution during Milling Process of Az91hp Magnesium Alloys

Zgórniak P., Grdulska A

Mechanics and Mechanical Engineering

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2012

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Vol. 16, nr 1

33--40

EN

The present paper deals with temperature distribution into cutting zone during end milling operation of magnesium alloy AZ91HP. The quality of the items is closely related to the state of the surface layer. High temperature generated during cutting process may cause risk of chips ignition when magnesium alloys is subjected to cutting process. Unfavorable phenomena such as the loss of hardness and cutting ability of the cutting tool. In recent years application of thermal imaging technique for monitoring material removal processes has dramatically increased. To determine influence of cutting velocity on maximum temperature appeared during end milling process infrared measurements were conducted. Results and conclusions is presented in the paper.

6

Surface characterization by accurate measurement and image processing systems on machined surfaces of precision cutting tools

Durakbasa N. M., Bogrekci I., Demircioglu P., Bas G., Gunay A.

Journal of Automation Mobile Robotics and Intelligent Systems

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2012

|

Vol. 6, No. 3

51-55

EN

High precise measurement techniques and surface structure analysis are required in advanced fields of interchangeable manufacturing and precision engineering. This study presents the characterization of the surface roughness of the machined milling cutters by experimental precision measurements and the image processing tool. The data obtained are compared to assess the surface characterization parameters and computational data in terms of precision, accuracy, sensitivity, repeatability and resolution. In the experimental measurement phase, the roughness measurements and surface topography characterization were performed in the nanotechnology laboratory using the stylus profilometry and digital microscopy. The computational phase was performed using an image processing toolbox with precise evaluation of the roughness for the machined metal surfaces of the end mill cutting tool. The surface parameter database is established exhibiting an advantage over the traditional method. This study reveals a comparison methodology of the end mill surface parameters using both stylus readings and image processing software for widely used end mill cutting tools that have considerable effect on characterization of sensitive manufacturing surface of millings.

7

Intelligent cutting tool condition monitoring in milling

Zuperl U., Cus F., Balic J.

Journal of Achievements in Materials and Manufacturing Engineering

|

2011

|

Vol. 49, nr 2

477--486

EN

Purpose: of this paper is to present a tool condition monitoring (TCM) system that can detect tool breakage in real time by using a combination of neural decision system, ANFIS tool wear estimator and machining error compensation module. Design/methodology/approach: The principal presumption was that the force signals contain the most useful information for determining the tool condition. Therefore, ANFIS method is used to extract the features of tool states from cutting force signals. The trained ANFIS model of tool wear is then merged with a neural network for identifying tool wear condition (fresh, worn). Findings: The overall machining error is predicted with very high accuracy by using the deflection module and a large percentage of it is eliminated through the proposed error compensation process. Research limitations/implications: This study also briefly presents a compensation method in milling in order to take into account tool deflection during cutting condition optimization or tool-path generation. The results indicate that surface errors due to tool deflections can be reduced by 65-78%. Practical implications: The fundamental limitation of research was to develop a single-sensor monitoring system, reliable as commercially available system, but much cheaper than multi-sensor approach. Originality/value: A neural network is used in TCM as a decision making system to discriminate different malfunction states from measured signals.

8

Analiza cech eksploatacyjnych innowacyjnych konstrukcji narzędzi wykorzystywanych w procesach frezowania zgrubnego z wykorzystaniem technologii HSM

Semotiuk L.

Eksploatacja i Niezawodność

|

2009

|

nr 1

46-53

PL

Rozwój systemów narzędziowych determinuje zmiany w doborze strategii obróbkowych wykorzystywanych w procesach obróbki skrawaniem. Jednym z przykładów jest frezowanie czołowe. Pojawienie się frezów do obróbki wgłębnej wymusiło na dystrybutorach oprogramowania typu CAM wprowadzenie do odpowiednich modułów nowej strategii obróbkowej, a co za tym idzie coraz częstszego wykorzystywania frezów czołowych w procesach obróbkowych. Artykuł ma na celu porównanie procesu skrawania z wykorzystaniem frezów jednolitych palcowych walcowo-czołowych i frezów wgłębnych z zastosowaniem technologii HSM oraz ocenę ich właściwości eksploatacyjnych na podstawie sił generowanych w strefie skrawania.

EN

The development of tooling systems determines changes in the selection of machining strategies used in machining processes. One example is face milling. The appearance on the market of plunge cutters has forced the distributors of CAM-type software to introduce into the appropriate modules a new machining strategy, thus leading to an ever more frequent use of face cutters in machining processes. The aim of this paper is to compare the processes of high speed machining that use integral-tooth end milling cutters to those using plunge milling cutters and to evaluate their operational properties on the basis of the forces generated in the machined zone.

9

Particle swarm intelligence based optimisation of high speed end-milling

Cus F., Zuperl U.

Archives of Computational Materials Science and Surface Engineering

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2009

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Vol. 1, nr 3

148-154

EN

Purpose: Selection of machining parameters is an important step in process planning therefore a new evolutionary computation technique is developed to optimize machining process. This study has presented multi-objective optimization of milling process by using neural network modelling and Particle swarm optimization. Particle Swarm Optimization (PSO) is used to efficiently optimize machining parameters simultaneously in high-speed milling processes where multiple conflicting objectives are present. The goal of optimization is to determine the objective function maximum (predicted cutting force surface) by consideration of cutting constraints. Design/methodology/approach: First, an Artificial Neural Network (ANN) predictive model is used to predict cutting forces during machining and then PSO algorithm is used to obtain optimum cutting speed and feed rates. Findings: During optimization the particles 'fly' intelligently in the solution space and search for optimal cutting conditions according to the strategies of the PSO algorithm. The simulation results show that compared with genetic algorithms (GA) and simulated annealing (SA), the proposed algorithm can improve the quality of the solution while speeding up the convergence process. Research limitations/implications: The experimental results show that the MRR is improved by 28%. Machining time reductions of up to 20% are observed. Practical implications: While a lot of evolutionary computation techniques have been developed for combinatorial optimization problems, PSO has been basically developed for continuous optimization problem. PSO can be an efficient optimization tool for solving nonlinear continuous optimization problems, combinatorial optimization problems, and mixed-integer nonlinear optimization problem. Originality/value: An algorithm for PSO is developed and used to robustly and efficiently find the optimum machining conditions in end-milling. This paper opens the door for a new class of EC based optimization techniques in the area of machining. This paper also presents fundamentals of PSO optimization techniques.

10

Optimisation of up- and down-milling processes for a corner feature

Dotcheva M., Millward H.

Zeszyty Naukowe Politechniki Rzeszowskiej. Mechanika

|

2008

|

z. 73 [253]

73-80

EN

This paper presents the specifics of the two types of end-milling, up- and down-milling, in the context of process planning of a finishing operation for machining complex pocket features. An optimisation mechanism is used for a pocket type of end-milling operation with the aim of comparing the results from up- and down-milling when the same process constraints have been applied. Two sets of cutting conditions have been generated and analysed for each type of end-milling. The first cutting condition has constant parameters for the entire tool path, derived from the worst case of cutting, representing the usual process planning approach The second set of cutting conditions represents the optimised process. The predicted results were verified through experiments. The optimised, measured cutting parameters, when machining the critical corner, accurately demonstrate the important changes in magnitude and direction of the radial cutting-tool deviation and surface error

11

Enhancement of machinability by workpiece preheating in end milling of Ti-6Al-4V

Hossain M. I., Nurul Amin A. K. M., Patwari A. U., Karim A.

Journal of Achievements in Materials and Manufacturing Engineering

|

2008

|

Vol. 31, nr 2

320-326

EN

Purpose: The main objective of this paper is to investigate the effect of workpiece preheating with high frequency induction heating on improvement of machinability of Ti-6Al-4V during end milling using PVD TiAlN coated inserts. Tool life, cutting force and vibration were investigated during the experiments. Design/methodology/approach: End milling tests were conducted on Vertical Machining Centre (VMC ZPS, Model: MCFV 1060 with quarter immersion cutting. Titanium based alloy Ti-6Al-4V bar was used as the work-piece. Machining was performed with a 20 mm diameter end-mill tool holder (R390-020B20-11M) fitted with one insert. PVD TiAlN coated carbide inserts (R390-11 T3 08E-ML 2030) were used in the experiments. All of the experiments were run at room temperature and preheated conditions. The preheated temperature was maintained at 420° C and no phase change of the workpiece in preheating was ensured from the phase diagram of Ti-6Al-4V. High frequency induction heating was utilized to run the preheated machining. Findings: Preheating helps in substantially increasing tool life and in lowering down the cutting force value, lowering the amplitude of vibration and dynamic forces. Practical implications: The cost of machining Ti-6Al-4V is extremely high because of the relatively low machining speed and short tool life. Therefore, improving the machinability of Ti-6Al-4V is a research topic of much interest, with a number of approaches reported with varied results, such as, cryogenic cutting, highpressure coolant, rotary-tool, and minimum quantity lubrication (MQL). Originality/value: A new approach of induction preheating to overcome the difficulties in machining of Ti-6Al-4V is presented in this paper. In preheated machining, high frequency induction heating is used as an external heat source to soften the work material surface layer in order to decrease its tensile strength and strain hardening. An experimental study has been performed to assess the effect of workpiece preheating using induction heating system to enhance the machinability of Ti-6Al-4V. The preheating temperature was maintained below the phase change temperature of Ti-6Al-4V.

12

High speed end-milling optimisation using Particle Swarm Intelligence

Cus F., Zuperl U., Gecevska V.

Journal of Achievements in Materials and Manufacturing Engineering

|

2007

|

Vol. 22, nr 2

75-78

EN

Purpose: In this paper, Particle Swarm Optimization (PSO), which is a recently developed evolutionary technique, is used to efficiently optimize machining parameters simultaneously in high-speed milling processes where multiple conflicting objectives are present. Design/methodology/approach: selection of machining parameters is an important step in process planning therefore a new methodology based on PSO is developed to optimize machining conditions. Artificial neural network simulation model (ANN) for milling operation is established with respect to maximum production rate, subject to a set of practical machining constraints. An ANN predictive model is used to predict cutting forces during machining and PSO algorithm is used to obtain optimum cutting speed and feed rate. Findings: The simulation results show that compared with genetic algorithms (GA) and simulated annealing (SA), the proposed algorithm can improve the quality of the solution while speeding up the convergence process. PSO is proved to be an efficient optimization algorithm. Research limitations/implications: Machining time reductions of up to 30% are observed. In addition, the new technique is found to be efficient and robust. Practical implications: The results showed that integrated system of neural networks and swarm intelligence is an effective method for solving multi-objective optimization problems. The high accuracy of results within a wide range of machining parameters indicates that the system can be practically applied in industry. Originality/value: An algorithm for PSO is developed and used to robustly and efficiently find the optimum machining conditions in end-milling. The new computational technique has several advantages and benefits is suitable for use combined with ANN based models where no explicit relation between imputs and outputs is available. This research opens the door for a new class of optimization techniques which are based on Evolution Computation in the area of machining.

13

Simulation investigation of nonlinear model of cutting process in end milling.

Pajor M., Marchelek K.

Advances in Manufacturing Science and Technology

|

2006

|

Vol. 30, nr 3

5-22

EN

The paper presents results of simulation of the end milling process. Simulation is based on nonlinear models of the mass-damping-spring system of the machine tool and a nonlinear model of the cutting process. Simulation investigations were performed using Matlab-Simulink. The apropropriate models were built on the basis of experiments. Results of calculation are compared with those obtained on the basis of linear models.

PL

W artykule przedstawiono wyniki symulacji procesu skrawania frezami walcowo-czołowymi. Symulację wykonano stosując nieliniowe modele układu masowo-dyssypacyjno-sprężystego obrabiarki oraz nieliniowy model procesu skrawania. Symulacje prowadzono z zastosowaniem systemu Matlab-Simulink. Modele opracowano na podstawie wyników badań doświadczalnych. Wyniki symulacji porównano z wynikami uzyskanymi dla modeli liniowych.

14

Tool wear prediction in machinning by using the adaptive neuro-fuzzy system

Zuperl U., Milfelner M., Cus F.

International Journal of Applied Mechanics and Engineering

|

2004

|

Vol. 9, no spec.

73-78

EN

The focus of this paper is to develop a reliable method to predict flank wear during end milling process. A neural-fuzzy scheme is applied to perform the prediction of flank wear from cutting force signals. In this contribution we also discussed the construction of a ANFIS system that seeks to provide a linguistic model for the estimation of tool wear from the knowledge embedded in the neural network. Machining experiments conducted using the proposed method indicate that using an appropriate force signals, the flank wear can be predicted within 4% of the actual wear for various end-milling conditions.

15

Badania symulacyjne nieliniowego procesu skrawania przy frezowaniu walcowo-czołowym - część II: symulacje komputerowe

Pajor M., Marchelek K., Bodnar A.

Zeszyty Naukowe Katedry Mechaniki Stosowanej / Politechnika Śląska

|

2003

|

z. 20

325-332

PL

W artykule przedstawiono wyniki symulacji numerycznych rozwoju drgań samowzbudnych przy frezowaniu walcowo-czołowym. Teoretyczne podstawy budowy modelu symulacyjnych przedstawiono w części I artykułu. W symulacjach wykorzystano liniowy i nieliniowy model systemu obrabiarka - proces skrawania. W nieliniowym modelu uwzględniono nieliniowości w układzie masowo - dyssypacyjno - sprężystym oraz nieliniowości procesy skrawania. Dokonano porównania wyników symulacji dla modelu liniowego i nieliniowego.

EN

The paper presents results of numerical simulations of the self-excited vibration development in face milling. Theoretical considerations and simplifications made during development of the model for simulations are presented m Part 1 of this paper. Simulations were carried out as well for linear as for nonlinear models of the machine tool - cutting process system I he nonlinear model incorporated main nonlinearities of the mass-spring-damping system of the machine (guideways connections) and the cutting process (cutting coefficients, loss of tool-workpiece contact). Results obtained for both ways of system modeling were compared.

16

Badania symulacyjne nieliniowego procesu skrawania przy frezowaniu walcowo-czołowym - część I: nieliniowy model systemu O-PS

Marchelek K., Pajor M., Bodnar A.

Zeszyty Naukowe Katedry Mechaniki Stosowanej / Politechnika Śląska

|

2003

|

z. 20

282-287

PL

W artykule przedstawiono metodę modelowania systemu obrabiarka - proces skrawania dla potrzeb symulacji rozwoju drgań samowzbudnych. W modelach układu masowo - dysypacyjno - sprężystego obrabiarki oraz w procesu skrawania uwzględniono nieliniowości fizyczne i geometryczne w nich występujące. Przedstawiony model zaimplementowano w systemie MATLAB-SIMULINK. Wyniki symulacji zamieszczono w części II artykułu.

EN

The paper presents a method of modeling the machine tool - cutting process system that is required for simulation of the self-excited vibration development. Physical and geometrical nonlinearities, which exist in the mass-spring-damping system of the machine and in cutting process, were included in the model. The model was implemented into Matlab-Simulink system. Results of simulations are presented and discussed in the second part of this paper.

17

Complex vibrostability analysis of machine tools in end milling. Part II. Application.

Pajor Mirosław

Advances in Manufacturing Science and Technology

|

2001

|

Vol. 25, nr 1

17-33

EN

Paper presents a computational example of the application of complex vibrostability analysis using stationary and nonstationary models of MT-CP system. Examinations were conducted for FWD-32J milling machine. Computational example includes also the reduction of MT-CP system model for the need of vibrostability and methodology of searching for the weak points in the body system with respect to vibrostability.

PL

W pracy zaprezentowano przykład obliczeniowy zastosowania algorytmu kompleksowej analizy wibrostabilności obrabiarki podczas frezowania walcowo-czołowego. Szczegółowo zilustrowano poszczególne etapy prognozowania wibrostabilności z wykorzystaniem modeli stacjonarnych i niestacjonarnych systemów O-PS. Badania przeprowadzono dla modelu frezarki FWD-32J. Przykład obliczeniowy obejmuje również zagadnienia redukcji modelu systemu O-PS dla potrzeb analizy wibrostabilności oraz metodykę poszukiwania w układzie korpusowym obrabiarki słabych ogniw, ze względu na wibrostabilność.