Tesi sul tema "Milling machinery"
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1
Herman, Paul Andrew. "Improvement of surface finish quality in peripheral milling VIA precision compensation for cutter runout". Thesis, Georgia Institute of Technology, 1992. http://hdl.handle.net/1853/16696.
Testo completo
2
Lazoğlu, İsmail. "Analysis and optimization of milling force system for workpiece with complicated geometry". Thesis, Georgia Institute of Technology, 1992. http://hdl.handle.net/1853/16032.
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3
Hekman, Keith Alan. "On-line identification of cutter runout in end milling processes". Diss., Georgia Institute of Technology, 1994. http://hdl.handle.net/1853/16748.
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4
Fan, Sai Kit. "An study of unit machine operations for tool paths in high speed milling /". View abstract or full-text, 2008. http://library.ust.hk/cgi/db/thesis.pl?IELM%202008%20FAN.
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5
Galiotto, A., e Adriano Peruzzi. "Cold Milling - 39: innovative temperature/humidity control on milling operation". Verein für Gerberei-Chemie und -Technik e. V, 2019. https://slub.qucosa.de/id/qucosa%3A34142.
Testo completoAbstract (sommario):
Content:
Air temperature and humidity are fundamental in the milling operation. There is a complicated correlation between air conditions and leather moisture that is practically impossible to predict in industrial process. Many important characteristics like softness, grain, pebble, yield depend on leather moisture. This patented system is the latest improvement in milling drums technology that keeps the leather cooler
and allows a precise and optimal humidity control.
Designed for soft, tight-grained leathers, especially from organic tannages and opened to a wide range of new operating conditions impossible with traditional machinery.
The original new design makes the milling drum completely independent from the outside environment with many advantages: consistency over seasons, shorter transition time, energy savings.
The original design is recognized by international patent, laboratory results on leather will be displayed during the presentation.
Take-Away:
The original new Cold Milling technology design makes the milling drum completely independent from the outside environment with many advantages: consistency over seasons, shorter transition time, energy
savings.
Nappa leather and all tight-grained leathers, especially organic tannaed, are beneficiary of this new technology.
6
Carpenter, Ian David. "Machinability assessment and tool selection for milling". Thesis, Online version, 1996. http://ethos.bl.uk/OrderDetails.do?did=1&uin=uk.bl.ethos.286659.
Testo completo
7
Liles, Howard J. "High throughput profile millling for the flexible and accelerated processing of electric steels". Thesis, Georgia Institute of Technology, 2013. http://hdl.handle.net/1853/47628.
Testo completoAbstract (sommario):
The proliferation of electric machines has drastically increased in recent years and is likely to increase into the future. This interest in the production of advanced, high power density electrical machines that are small in size has heightened the need for flexible manufacturing processes to produce their laminated components during short batch and prototyping production runs. A means of cost effective, accelerated prototyping of these machines will have a substantial impact on their design and optimization, reducing time requirements to produce and test a given design. A review of the current manufacturing methods for prototyping electric machines was conducted. In particular, laser cutting, electric discharge machining, and abrasive waterjet (AWJ) machining were researched as competitive processes. Each of these methods exhibits marked advantages and disadvantages that present the opportunity for a new process to compete. This work investigates the applicability of high throughput profile milling (HTPM) for the prototyping of advanced electric machines, specifically, the process parameter space for milling of electrical steels. The material response will be determined by characterizing its specific cutting energy and utilizing this to develop a model to predict cutting forces during the milling process. Optimal process parameters will be investigated to obtain maximum productivity and minimal burr formation. Finally, the impact of HTPM processing on the magnetic properties of electrical steels will be compared to that of a leading prototyping technology, AWJ machining.
8
Thompson, Michael B. "Development of a five-axis machining algorithm in flat end mill roughing /". Diss., CLICK HERE for online access, 2005. http://contentdm.lib.byu.edu/ETD/image/etd823.pdf.
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9
Fowler, Gary. "Abrasive water-jet : controlled depth milling of titanium alloys". Thesis, University of Nottingham, 2003. http://eprints.nottingham.ac.uk/11436/.
Testo completoAbstract (sommario):
Abrasive waterjet (AWJ) technology is used in a routine manner in manufacturing industry to cut materials that are difficult to cut by other methods. Whilst the technology for through cutting of materials is mature, the process is also being developed for controlled depth milling (CDM) of materials. The aerospace industry have a requirement to remove redundant material from components manufactured from difficult to machine Ti6Al4V and titanium aluminide alloys and thus reduce component weight. The two main processes available to facilitate this are chemical milling and AWJ-CDM. The two processes have the advantage that they impose negligible forces, thus allowing flexible structures to be processed. However, the process of chemical milling is under threat due to the high costs associated with the disposal of the spent acids. Thus, this research seeks to evaluate the A WJ-CDM process as a replacement for chemical milling for Ti6A14V and titanium aluminide alloys. The magnitude and effect of the process characteristics of chemical milling on fatigue life are well established; however, this is not the case for AJW-CDM. The aerospace industry considers the characteristics of surface roughness, grit embedment and surface morphology to be significant parameters in determining the fatigue life of components manufactured using AJW-CDM. Therefore, before AJW-CDM can be considered a viable alternative, the effect of the process variables on the workpiece characteristics have first to be established. The current research has determined the role of a number of process parameters on the material removal rate, roughness and waviness, grit embedment and surface morphology in the AJW-CDM of Ti6AI4V and titanium aluminide. Nozzle traverse speed and jet impingement angle are shown to govern the operative mechanism of material removal and thus the material removal rate. It is also shown that the surface waviness can be reduced as the traverse speed is increased and as the jet impingement angle is decreased, but it should be noted that waviness increases with number of passes of the jet over the workpiece. The surface roughness is not strongly dependent on traverse speed. Surface waviness and roughness are strongly dependent on jet impingement angle; significant reductions are possible by employing low angle milling techniques. Smaller sized grit leads to a reduction in material removal rate but also to a decrease in both waviness and roughness. It has been demonstrated that grit embedment can be minimised either by milling with a high jet traverse speed at low impingement angles or by low speed milling at jet impingement angles up to 45°in the backward direction only. However, even in the best cases, 5% of the area of a milled surface comprised of embedded grit. Surface morphology can either exhibit directional grooving or cratering, depending upon complex interactions of the various processing parameters. The understanding of the role of various process parameters on the workpiece characteristics will allow the process parameters to be optimised for given requirements. Future work needs to examine the fatigue performance of the AJW-CDM structures, and again optimisation of the processing parameters to maximise fatigue life can be performed. Masking has been employed to provide an economic manufacturing solution for the AJW-CDM process for a specific component. Thus, AJW-CDM has been established as a potential replacement process for chemical milling.
10
El-Hofy, Mohamed Hassan. "Milling/routing of carbon fibre reinforced plastic (CFRP) composites". Thesis, University of Birmingham, 2014. http://etheses.bham.ac.uk//id/eprint/5529/.
Testo completoAbstract (sommario):
The research relates to a study on the routing/slotting of CFRP composites of the type used in aerospace applications. Following a literature review, 3 phases of experimental work were undertaken to evaluate the effects of key process variables on the machinability of CFRP. The influence of varying operating parameters, tool material and cutting environment were initially investigated in Phase 1 work. The results showed that use of PCD was critical and highlighted the importance of chilled air in maintaining adequate tool life and acceptable workpiece integrity. Delivery of chilled air through a single-nozzle arrangement generally led to an increase in forces and delamination with the twin-nozzle configuration showing superior workpiece surface roughness. Phase 2 work detailed the effect of workpiece lay-up configuration on cutting forces, temperature and surface integrity following slotting and routing. Plies in the 45 direction generally exhibited the highest level of surface damage following machining. Experiments in Phase 3 showed that relatively small helix angles (± 3) had a negligible effect on tool life, forces and temperature. In addition, cutters with a single relief angle were found to have lower stability in operation compared to tools with a secondary clearance angle, with detrimental effects on surface roughness.
11
Fussell, Barry K. "Modeling and adaptive force control of end milling operations /". The Ohio State University, 1987. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487327695620678.
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12
Alharbi, W. N. H. "Development of a closed loop control system for vibratory milling". Thesis, Liverpool John Moores University, 2018. http://researchonline.ljmu.ac.uk/8456/.
Testo completoAbstract (sommario):
Manufacturing makes ever-increasing demands for higher machining speeds. This is particularly true in car and aircraft production, but also for cutting tools. Vibration is used in various technological processes to improve the performance of the machines by intelligently exploiting the synergy of the oscillations. Vibration provides several benefits for various technologies, such as manufacturing, medical, communications, transport, industries, etc. Vibration assisted machining techniques have recently become an area of interest for many engineering applications. In machining processes, vibration can lead to improvements when applied in a controlled manner. Vibration assisted machining is a technique in which a certain frequency of vibration is applied to the cutting tool or the Workpiece to achieve better cutting performance The aim of this project is to apply vibration to the work-piece during milling process in order to improve the machining performance. In this project, a theoretical modelling and experimental implementation of vibratory milling process are presented and explored in depth. The modelling focused on the control system which tracked and regulated the vibration amplitude in the cutting zone during machining. Here, hardware and software of advanced technology of LabVIEW applications were used to develop implement and optimise the control system. The machine tool static, dynamic and compliance characteristics were investigated in terms of static analysis, natural frequencies and dynamic stiffness, using harmonic excitation, hammer impact test and the application of external forces. Preliminary studies were undertaken, where, the effect of cutting parameters were evaluated and the optimal cutting conditions were determined. Series of machining tests were undertaken, with the aim of recording process performance data in terms of cutting forces that were used for the development of the control system. A closed loop PID controller was developed using advanced Field-Programming-Gate-Array (FPGA) and Real-time Labview applications, using a non-interrupted real time target PC. An innovative and unique combination of FPGA and target PC allow the control system to have a very fast response in keeping the set amplitude of the vibration whilst recording simultaneously the machining data for further analysis. Aluminium and mild Steel were using in this investigation, along with a comparative study between conventional and vibratory milling and between open loop and closed loop control systems. The results of this investigation show the benefits of the superimposed vibration. The outperformance of the vibratory machining over the conventional milling provides a very promising outlook for the application of subsonic vibration into machining as an alternative to ultrasonic process.
13
Sharif, Safian. "Face milling of titanium coated alloys using coated and uncoated carbide tools". Thesis, Coventry University, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.299091.
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14
Browne, D. G. "Development of a bench test to evaluate wear resistant materials and coal grindability for pulverizers". Thesis, Queensland University of Technology, 1987. https://eprints.qut.edu.au/36468/1/36468_Browne_1987.pdf.
Testo completoAbstract (sommario):
This report describes development work undertaken
to provide a simple, economically advantageous test to
reliably predict wear resistance or materials used in
slow and medium speed coal pulverizers.
Firstly the existing literature on abrasion and
erosion was used to analyse and identiry the principal
wear mechanisms reported to be operating in the pulverizers.
Secondly, the important parameters arrecting
wear were evaluated with respect to conditions occurring
in coal pulverizers. This inrormation was then
used as the criterion ror the selection and development
or a suitable wear test.
The existing apparatus and procedures or the coal
abrasion index test originally developed by Yancey,
Geer and Price was chosen ror the basis or the development
programme. Minor modirications were made to the
apparatus to allow the measurement and recording or
applied torque on the machine blades. Initial testing
with mild steel blades and coal as an abrasive gave the
rollowing results:
(i) Provided conditions were controlled within
reasonable bounds, the precision or the test was comparable
with other wear tests.
(ii) The majority or wear occured in the rirst
quarter or the test. (ie. 60¾ or wear took place
during the rirst 3000 revs. or a 12000 rev. total.)
(iii) Comparison between the wear scars on a test
blade and a mill ball using SEM techniques, indicated similar wear mechanisms occurred in the test apparatus
and the pulverizers.
These results were used as the :basis Tor the
design o± a test, which incorporated a potential 'standard'
abrasive consisting OT a ±oundry sand/epoxy mix,
heat cured into pellets 6mm dia :by 6mm long. The test
was used to evaluate the wear resistance o± three
di±±erent materials; Nihard 2, manganese steel and mild
steel, and produced satis±actory results ±or precision
and ranking.
Finally work was carried out to explore the possibilities
o± utilizing the energy expended during the
comminution OT the coal, together with sieve analysis
data, as an indication OT the grinda:bility or the coal.
Initial results were encouraging and warrant Turther
work to confirm the correlation :between the measured
variables (ie. energy and size reduction) and the presently
accepted method OT indicating coal grindability,
the Hardgrove Grindability Index values.
15
Niu, Caotan. "A study of tool life and machinability parameters in high speed milling of hardened die steels". Click to view the E-thesis via HKUTO, 2007. http://sunzi.lib.hku.hk/HKUTO/record/B39557170.
Testo completo
16
Skorupa, Jan J. "Wear of tube mill liners for South African power industry". Thesis, University of Cape Town, 1989. http://hdl.handle.net/11427/23382.
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17
Ma, Lei. "PVDF sensor based wireless monitoring of milling process". Diss., Georgia Institute of Technology, 2013. http://hdl.handle.net/1853/47714.
Testo completoAbstract (sommario):
Analytical force and dynamic models for material removal processes such as end and face milling do not account for material and process related uncertainties such as tool wear, tool breakage and material inhomogeneity. Optimization of material removal processes thus requires not only optimal process planning using analytical models but also on-line monitoring of the process so that adjustments, if needed, can be initiated to maximize the productivity or to avoid damaging expensive parts. In this thesis, a Polyvinylidene Fluoride (PVDF) sensor based process monitoring method that is independent of the cutting conditions and workpiece material is developed for measuring the cutting forces and/or torque in milling. The research includes the development of methods and hardware for wireless acquisition of time-varying strain signals from PVDF sensor-instrumented milling tools rotating at high speeds and transformation of the strains into the measurand of interest using quantitative physics-based models of the measurement system. Very good agreement between the measurements from the low cost PVDF sensors and the current industry standard, piezoelectric dynamometer, has been achieved. Three PVDF sensor rosettes are proposed for measuring various strain components of interest and are shown to outperform their metal foil strain gauge counterparts with significantly higher sensitivity and signal to noise ratio. In addition, a computationally efficient algorithm for milling chatter recognition that can adapt to different cutting conditions and workpiece geometry variations based on the measured cutting forces/torque signals is proposed and evaluated. A novel complex exponential model based chatter frequency estimation algorithm is also developed and validated. The chatter detection algorithm can detect chatter before chatter marks appear on the workpiece and the chatter frequency estimation algorithm is shown to capture the chatter frequency with the same accuracy as the Fast Fourier Transform (FFT). The computational cost of the chatter detection algorithm increases linearly with data size and the chatter frequency estimation algorithm, with properly chosen parameters, is shown to perform 10 times faster than the FFT. Both the cutting forces/torque measurement methodology and the chatter detection algorithm have great potential for shop floor application. The cutting forces/torque measurement system can be integrated with adaptive feedback controllers for process optimization and can also be extended to the measurement of other physical phenomena.
18
Patel, Bhavin Ramesh. "State space formulation of TFEA & uncharted islands of instability in milling". Diss., Columbia, Mo. : University of Missouri-Columbia, 2007. http://hdl.handle.net/10355/4898.
Testo completoAbstract (sommario):
Thesis (M.S.)--University of Missouri-Columbia, 2007.The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file (viewed on January 7, 2008) Includes bibliographical references.
19
Niu, Caotan, e 牛草坛. "A study of tool life and machinability parameters in high speed milling of hardened die steels". Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2007. http://hub.hku.hk/bib/B39557170.
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20
Lohse, Benjamin H. "The controlled ball milling of titanium and carbon to form TiC /". Access electronically, 2005. http://www.library.uow.edu.au/adt-NWU/public/adt-NWU20060221.110552/index.html.
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21
Pisipati, Deepak. "Virtual manufacturing of pockets using end milling with multiple tool paths". Ohio : Ohio University, 2004. http://www.ohiolink.edu/etd/view.cgi?ohiou1177011829.
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22
Zemčík, Tomáš. "Simulace průběhu řezné síly při obvodovém frézování válcovou frézou s přímými zuby". Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2010. http://www.nusl.cz/ntk/nusl-229250.
Testo completoAbstract (sommario):
To make a simulation of cutting force during milling process with cilindrical cutter is the aim of this diploma thesis. Preliminary part is devoted to technology of milling, milling cutters and cutting materials. The next section is aimed at kinematics of the cutting process, a theoretical analysis of power proportion, the possibility of measurement of force actions. General information about the programming software, a theoretical simulation model, graphical environment of created application, are the other points of this diploma thesis. The work also includes evaluation of the experimentally measured values and compared with values obtained from the created application.
23
Machalová, Veronika. "Řezné síly při frézování vláknově vyztužených kompozitů". Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2008. http://www.nusl.cz/ntk/nusl-227947.
Testo completoAbstract (sommario):
Cutting forces problems analyses during milling operation, description of experimental machinery for measuring cutting forces. Characteristic of composite materials, their properties, production and usage. Evaluation of experimentally measured values of cutting forces during cylindrical conventional milling. Technical economic evaluation.
24
Zlámal, Pavel. "Projekt lehké obrobny v TOS Kuřim - OS, a.s. - frézařské pracoviště". Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2008. http://www.nusl.cz/ntk/nusl-227971.
Testo completoAbstract (sommario):
The main theme of my thesis is a design of project the organization a light machinery production in TOS Kuřim – OS, a.s. – for production prismatic parts to the materialiaty 250 kg of milling. The thesis concentrates mainly on a formal process of the design eworkplaces. First part of the thesis comprises of general introduction of design project of workshop and using methods projecting of wokshops, ergonomics parameters and organization of machines. In the follow-on charter is effected description status quo prodiction of prismatic parts and proposal make-up freesia workplaces. To choice variant is created common load evaluation workplace, documentation and evaluation contribution.
25
Dhamija, Dinesh. "Macintosh - Bridgeport communications CAD/CAM". Ohio : Ohio University, 1988. http://www.ohiolink.edu/etd/view.cgi?ohiou1182784285.
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26
Renuka, Shivaswaroop R. "Development of models of CNC machines - EMCO VMC100 and EMCO TURN120P in virtual NC". Ohio : Ohio University, 1996. http://www.ohiolink.edu/etd/view.cgi?ohiou1178046654.
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27
Герасим’юк, Валерій Михайлович, e Valerii Herasymiuk. "Обґрунтування конструкції елементів приводу головного руху вертикально-фрезерного верстату". Master's thesis, ТНТУ ім. І. Пулюя, 2019. http://elartu.tntu.edu.ua/handle/lib/29680.
Testo completoAbstract (sommario):
Роботу виконано на кафедрі конструювання верстатів, інструментів та машин Тернопільського національного технічного університету імені Івана Пулюя Міністерства освіти і науки України
Захист відбудеться 24 грудня 2019 р. о 11.00 годині на засіданні екзаменаційної комісії №10 у Тернопільському національному технічному університеті імені Івана Пулюя за адресою: 46001, м. Тернопіль, вул. Руська, 56, навчальний корпус №4, ауд. 101У дипломній роботі проведено аналіз конструктивних особливостей базової моделі верстату, а також верстатів-аналогів. Здійснено аналіз загальних структур приводів головного руху вертикально-фрезерних верстатів. Проведено обґрунтування компонувальної схеми та технологічних параметрів для модернізації верстата. Здійснено розробку структури модернізованого приводу на основі морфологічної матриці. На основі проведено аналізу вибрано оптимальну компонувальну схему шпиндельного вузла та проведено дослідження впливу кількості підшипників в передній опорі на жорсткість шпиндельного вузла. Проведено кінематичний і силовий розрахунок ступеневої та безступеневої частин приводу, на основі яких розроблено конструкції коробки швидкостей, шпиндельного вузла, а також системи переключення між ступеневою і безступеневою частинами приводу головного руху вертикально-фрезерного верстату. Проведено розрахунок вартості модернізації приводу головного руху верстата. Розроблені технічні рішення обґрунтовано на основі вимог охорони праці, безпеки життєдіяльності та охорони навколишнього середовища.
Analysis of the structural features of the machine-tool basic model, as well as similar machine-tool, has been carried out in the diploma paper. Analysis of the general structures of the vertical-milling machine main feed drive was performed. The component scheme and technological parameters for the updating of the machine were interpreted. The structure of the improved drive basing on the morphological matrix was developed. The optimal compiling scheme of the spindle unit was chosen basing on it and investigation of the effect of the bearings number in the initial support on the spindle unit rigidity was performed. Kinematic and strength calculations of the speed drive and variable-speed drive part were done, basing on which the design of the gear-box, spindle unit and the system of gearing between speed drive and variable-speed drive of the main feed drive of the vertical-milling machine have been carried out. The calculation of the expenditures for the updating of the main feed of the machine-tool was done. The developed engineering solutions were interpreted to meet the requirements of the health and safety program and the program of the environment protection.
Вступ, Аналітичний розділ, Аналіз формоутворення, Обґрунтування компонувальної схеми верстату, Технологічний розділ, Науково-дослідний розділ, Конструкторський розділ, Спеціальний розділ, Охорона праці та БЖД, Екологія, Обґрунтування економічної ефективності, Висновки, перелік посилань
28
Tsui, Kin-shing. "Tool path generation for protrusion milling". Click to view the E-thesis via HKUTO, 2006. http://sunzi.lib.hku.hk/hkuto/record/B36891332.
Testo completo
29
Shorr, Michael Jared. "Dynamic stability analysis for multi-flute end milling". Diss., Georgia Institute of Technology, 1995. http://hdl.handle.net/1853/17789.
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30
Perry, Stephen Alan. "Precision compensation for cutter runout in peripheral milling". Thesis, Georgia Institute of Technology, 1991. http://hdl.handle.net/1853/18200.
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31
Bondar, I. V. "Five-axis machining on CNC milling machines". Thesis, Sumy State University, 2017. http://essuir.sumdu.edu.ua/handle/123456789/65171.
Testo completoAbstract (sommario):
At present, the parts of the machines are becoming more complex and precise. This requires the development of new machining technologies. Under these conditions, multi-axis CNC machining is one of those technologies. In spite of the 20-year history of its development, this approach still requires increasing efficiency in the implementation due to modern tasks.
32
Yuan, Weifeng. "Greedy tool heuristic for rough milling of complex pockets /". View Abstract or Full-Text, 2002. http://library.ust.hk/cgi/db/thesis.pl?IEEM%202002%20YUAN.
Testo completoAbstract (sommario):
Thesis (M. Phil.)--Hong Kong University of Science and Technology, 2002.Includes bibliographical references (leaves 48-52). Also available in electronic version. Access restricted to campus users.
33
Tsui, Kin-shing, e 徐健成. "Tool path generation for protrusion milling". Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2006. http://hub.hku.hk/bib/B36891332.
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34
Powell, Malcolm S. "The effect of liner design upon charge motion in a rotary mill". Master's thesis, University of Cape Town, 1988. http://hdl.handle.net/11427/21925.
Testo completoAbstract (sommario):
Rotary mills are used extensively to reduce the coarse rocks of mined ores down to a product fine enough to facilitate the extraction of the valuable minerals. On the South African gold mines alone about 110 million tons of ore is mined annually, at a power cost of about R90 million, and a liner material cost of about R30 million. The charge motion in mills has been studied both theoretically and experimentally since the beginning of the century. However, a lot of the work has been purely empirical, and some of it illconceived, resulting in there still being a poor understanding of the topic. The influence of lifter-bars upon charge motion has only been considered in the past few decades, and mostly to a very limited extent. This state of affairs has left the field wide open to further research. The charge motion of an isolated rod or ball, and how it is influenced by a flat-faced lifter-bar of any face-angle and of any height, was modelled theoretically. The charge motion of rods in a glass-ended mill was filmed with a high-speed camera. The mill was fitted with a variety of lifter-bars with different face-angles and heights, and was run at a wide range of speeds. The filmed trajectories of the rods were then tracked. The coefficients of friction between the rods and lifter-bar material were measured under vibrating conditions as are found in the mill. The power draw of the mill was also measured at a wide range of mill speeds, and with lifter-bars of different heights in the mill. A good correlation between the theoretical predictions and experimental results was found over a wide range of conditions. The impact point, at which the grinding element strikes the mill shell, was considered to be of primary importance in the analysis. It was found that the height of the lifter-bar has a strong influence on charge trajectories, as the height increases from zero up to just greater than one charge radius. Thereafter the lift increases until a critical lifter-bar height is reached, beyond which the grinding element is projected off the lifter prior to reaching the tip, the height of the impact point increasing slightly and then decreasing to a constant height. However, the change in the height of the impact point is very small, so in practical terms an increase in lifter-bar height, once it is higher than the radius of the grinding element, has a very small effect upon the charge trajectories. An increase in the angle of the lifter-bars was found to have a strong influence upon the height of the charge trajectories. A linear relationship between the mill speed and the impact angle was dicovered, and changes in the mill speed strongly influence the charge trajectories. It was also found that the power draw of a mill depends on the liner configuration, with power draw decreasing as the lifter-bar height is increased. Some new and surprising effects of lifter-bar geometry upon the charge trajectories, which are of great practical importance, have been discovered. The theoretical model is an advance upon all previous models, and agrees well with experimental results over a wide range of conditions.
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Kirk, Dean Frederick. "Development of a Small Envelope Precision Milling Machine". Thesis, University of Canterbury. Mechanical Engineering, 2006. http://hdl.handle.net/10092/2773.
Testo completoAbstract (sommario):
The credit card industry is huge with over two and a half billion cards shipped annually. A local card manufacturer, with a production volume in excess of forty million cards annually, approached the University of Canterbury to design and develop advanced card manufacturing technology. The motivation behind this development was the desire of the sponsoring company to keep abreast of new technologies and to have the ability to manufacture and supply cards with this new and emerging technology into a highly competitive world market. This thesis reports the research surrounding the development of a dedicated new machine tool explicitly designed to implement the emerging technologies found in the international credit card industry. The machine tool, a dedicated milling machine, was not developed in its entirety within these pages; however, three major constituents of the machine were researched and developed to a point where they could be implemented or become the subject of further research. The three areas of interest were; • A machine table system that avoided the increased zonal wear to which linear bearings are subject, typically due to short high frequency traversals, and also the high friction and mass generally found in dovetail slides. • Design requirements demanded the use of a single commercially available carbide cutter to produce 1500 components per hour. Therefore, a purpose built high (revs per minute) rpm spindle and drive system specifically for use with polymeric materials, (R-PVC in particular) was deemed necessary. • Tracking the cutter depth in relation to an RFID aerial track embedded within the credit card core. The aerial tracking was to be dynamic and occur during the machining process with the machine “remembering” the depth of cut at contact with the aerial. Each of the three areas was researched via an in-depth literature review to determine what and if any material had been published in these fields. For the development of the machine table a novel flexure hinge idea was considered. Considerable material was discovered about flexures, but very little was found to be relevant to the application of high displacement metal flexures necessary to meet the required levels of table movement. In effect the proposed machine table system and research in this field would be novel. The high performance spindle investigation became directed into a much narrower focus as it progressed; that of determining the power consumption required to machine the integrated circuit pockets in an R-PVC work piece. This was due to the lack of information pertaining to the physical properties of polymeric materials, in particular the specific cutting pressure. The depth following sensor array was configured using capacitance detection methods to determine the distance between the cutter?s end and the aerial tracks. Capacitance sensing methods, whilst not new, were developed into a novel arrangement to meet the specific cutter tracking requirements of the proposed new machine tool. Each of the respective development areas had concept designs completed and were prototyped before being tested to determine the effectiveness of the respective designs. The outcomes from the testing are reported herein, and show each constituent part to be basically feasible, in the application. The results were sufficient to indicate that each development showed distinct potential but further development and integration into the machine tool should ensue.
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Rathbun, Geoffrey P. "A Stewart Platform six-axis milling machine development". Thesis, University of Canterbury. Engineering, 1986. http://hdl.handle.net/10092/6421.
Testo completoAbstract (sommario):
This manuscript describes the development of an experimental NC milling machine having control over all the 6 bodily degrees of freedom of movement.
The mechanism used is called a Stewart Platform. These mechanisms have a platform connected to a base by 6 variable length "legs". The Stewart Platform is considered to have good potential as a rigid 5 axis milling machine having a simpler structure than conventional machines.
Platform motion is achieved by pre-calculated movements of 6 stepper motors which actuate leg mounted lead screws. These movements are controlled using microcomputer controlled electronic hardware.
The development of the system progressed along several paths among which were: path synthesis methods in six dimensions, stepper motors, simultaneous open-loop control of 6 data manipulation and storage structures in software to execute the control strategies, and the development of the existing positioning machine for milling operations.
The system was successfully developed to enable machining of rigid urethane foam blocks in 5 useful degrees of freedom. The envelope of movement was restricted to +/- 100mm translations and +/- 30 degree rotations. Accuracy of movement was beyond that detectable using foam.
Suggestions are made for further developments, particularly for improving the machine's envelope of movement and method of actuation.
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Sahari, M. "The microcomputer and the engraving/profile milling machine". Thesis, University of Bristol, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.356231.
Testo completo
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Grebchenko, A. "Mechanization and automation gear milling". Thesis, Сумський державний університет, 2013. http://essuir.sumdu.edu.ua/handle/123456789/33627.
Testo completoAbstract (sommario):
Cutting teeth is the most time consuming process in the technology of gears. It spent 50 - 60% of the total labor input processing gear. Therefore, improving the efficiency of the process is an important task gear milling machine.
When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/33627
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Köksal, Sakip. "Face milling of nickel-based superalloys with coated and uncoated carbide tools". Thesis, Coventry University, 2000. http://curve.coventry.ac.uk/open/items/86a6b065-704a-475b-b805-9d3397487ddf/1.
Testo completoAbstract (sommario):
Face milling machinability investigation of two difficult-to-machine nickel-based superalloys, namely Inconel 718 and Waspaloy, has been carried out with four different types of tungsten carbide tools under various cutting conditions. The tools comprised of one double-layer CVD-TiCN+Al2O3 coated (KC994M), two PVD-TiN coated (KC720 and KC730) and one uncoated (KMF) tungsten carbide tools. The objectives of the study include investigation of tool performance, failure modes and wear mechanisms under the cutting conditions employed. In addition, surface integrity of the machined surfaces, with regard to surface finish, subsurface microhardness and metallographic examination of the subsurface microstructure, was investigated. CVD-coated KC994M gave the best overall performance in terms of tool life at low and high cutting conditions on both workpieces. The second best-performing tool was the uncoated KMF grade which gave as high tool lives as KC994M at lower cutting speeds. However at higher cutting speeds, KMF was generally outperformed by PVD-TiN coated tools. Short tool lives were obtained at higher cutting speeds of 75 and 100 m/min due to premature failure by chipping. Tool wear at low cutting speed range was due to a combination of progressive microchipping and plucking through a fracture/attrition related wear mechanism associated with cyclic workpiece adhesion and detachment and abrasion/diffusion-related flank wear. Plucking and microchipping were the dominant wear mechanisms. Coating layers on the rake face of both CVD and PVD coated tools were almost completely removed within the first few seconds of cutting at all cutting speeds tested, thus becoming ineffective. On the flank face, however, they remained intact for a longer period and hence increasing tools performance at the medium cutting speed range. Analysis of the subsurface microstructures and microhardness measurements showed that plastic deformation was the predominant effect induced onto the machined surface, the degree of which influenced by the cutting speed, tool wear and prolonged machining. In addition surface irregularities in the form of tearing and embedded hard particles were found to occur which was mainly associated with the chipping dominated wear mode.
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Pafkovič, Roman. "Analýza rizik provozované CNC frézky MCV 754Q". Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2019. http://www.nusl.cz/ntk/nusl-399342.
Testo completoAbstract (sommario):
This Master’s thesis deals with the safety of an operated CNC milling machine. The first part of the thesis is focused on the legislative requirements of the European Union and the Czech Republic, system analysis of the topic and used methods. The second part of the thesis is focused on the risk analysis of the chosen machinery.
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Abrari, Farid. "Multi-axis milling of flexible parts /". *McMaster only, 1998.
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Fortgang, Joel D. "Combined Mechanical and Command Design for Micro-Milling Machines". Diss., Georgia Institute of Technology, 2006. http://hdl.handle.net/1853/10430.
Testo completoAbstract (sommario):
The utilization of micro-scale technologies is limited by the speed of their manufacture. Micro-milling is one particular technology used to manufacture micro-scale parts which could benefit extensively from an increase in throughput. Micro-milling involves a rotating cutter slightly thicker than a human hair removing material while spinning at speeds often over one hundred thousand revolutions per minute.
An obvious solution to the throughput bottleneck is to move current micro-mills faster using existing technology; however, simply increasing the operational speed of existing micro-mills will lead to vibration and trajectory following problems. If a micro-mill cannot be positioned precisely, then part tolerances cannot be maintained. Thus any increase in throughput would be counterproductive in terms of overall performance.
This dissertation presents techniques to improve the performance of micro-mills, as well as other flexible machines. Theses improvements are possible through the utilization of the vibration suppression scheme of input shaping. By thoughtfully altering the commands sent to flexible systems, their vibration can be significantly reduced. Input shaping was effectively applied to an existing micro-mill, which improved part tolerances and increased operational speed. However, at extremely high speeds, traditional input shaping is not effective at following complicated trajectories. Therefore, new input shaping techniques were developed specifically for trajectory tracking of extremely fast motions on micro-mills and other flexible systems. Often machines cannot achieve these high speeds while maintaining their accuracy because of the mechanical design of the machines themselves. If the mechanical design of micro-mills and other machines consider flexible and lightweight design alternatives that utilize input shaping for vibration suppression instead of stiff and heavy designs, then faster machine motion will be possible. By considering input shaped flexible systems as part of traditional mechanical design processes, these flexible solutions allow vast performance improvement. Specifically, embodiment design can be improved through consideration of input shaping performance requirements. Through these advancements, this dissertation improves the design, control, and performance of micro-mills and other flexible machines.
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Stevens, Anthony J. "An adaptive mimo application of the repetitive controller for runout force rejection in peripheral milling". Thesis, Georgia Institute of Technology, 1993. http://hdl.handle.net/1853/17669.
Testo completo
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Ebrahimi, S. Morteza K. "Dynamic modelling and simulation of a CNC milling machine". Thesis, Cardiff University, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.287909.
Testo completo
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Son, Seung-Kil 1964. "A hybrid type small 5-axis CNC milling machine". Thesis, Massachusetts Institute of Technology, 2002. http://hdl.handle.net/1721.1/29275.
Testo completoAbstract (sommario):
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2002.Includes bibliographical references (leaves 116-119).
5-axis CNC milling machines are important in a number of industries ranging from aerospace to consumer-die-mold machining because they can deliver high machining accuracy with a spindle tilting capacity. Most of these machines have serial mechanisms so that low static and dynamic stiffness become very critical design issues especially for high speed machining. Parallel mechanisms have recently received attention from machine tool designers because of their inherent potential for stiffness and because of their compactness. However, much of the promised advantages of parallel machines only occur within a very small region of their workspace with the expense of the large machine-tool foot print. We discuss some of the kinematic and structural challenges to extracting machining performance from serial and parallel machines. We compare a hybrid machine, which combines serial and parallel mechanisms, with typical serial and parallel machines such as Euler angle machines and the Hexapod. In particular, we consider singularities, reversal characteristics, and manufacturability. We show that hybrid machines can benefit from the advantages of serial and parallel mechanisms while avoiding most potential pitfalls of both mechanisms. However, hybrid structures can suffer from the manufacturing problem of over-constraint. We show that the degree of over-constraint depends on the size of the parallel machine. We have designed and fabricated a small hybrid 5-axis motion platform, the MIT-SS-1, which can tolerate this over-constraint through a novel layout of axes. Numerical and experimental test results of the MIT-SS-1 are presented and compared. Finally we show that this structure has potential as a small 5-axis CNC milling machine.
by Seung-Kil Son.
Ph.D.
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Golaski, Edmund Walter 1976. "Direct haptic control of a 3-axis milling machine". Thesis, Massachusetts Institute of Technology, 2001. http://hdl.handle.net/1721.1/88887.
Testo completo
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Коротун, Микола Миколайович, Николай Николаевич Коротун, Mykola Mykolaiovych Korotun, Г. Ананченко e H. Ananchenko. "The construction and functions of the universal milling machine". Thesis, Вид-во СумДУ, 2010. http://essuir.sumdu.edu.ua/handle/123456789/5552.
Testo completo
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Čunek, Jakub. "Konstrukce jednoúčelového frézovacího stroje". Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2013. http://www.nusl.cz/ntk/nusl-230489.
Testo completoAbstract (sommario):
This thesis provides a brief introduction to the technology milling and analysis of various parts of milling machines. In addition, this thesis focuses on the design of a dedicated milling machine for machining functional areas of aluminum cast.
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Ozgen, Arda. "Cutting Strategies For Forging Die Manufacturing On Cnc Milling Machines". Master's thesis, METU, 2008. http://etd.lib.metu.edu.tr/upload/12609433/index.pdf.
Testo completoAbstract (sommario):
Manufacturing of dies has been presenting greater requirements of geometrical accuracy, dimensional precision and surface quality as well as decrease in costs and manufacturing times. Although proper cutting parameter values are utilized to obtain high geometrical accuracy and surface quality, there may exist geometrical discrepancy between the designed and the manufactured surface profile of the die cavities. In milling processcutting speed, step over and feed are the main cutting parameters and these parameters affect geometrical accuracy and surface quality of the forging die cavities. In this study, effects of the cutting parameters on geometrical error have been examined on a representative die cavity profile. To remove undesired volume in the die cavities, available cutting strategies are investigated. Feed rate optimization is performed to maintain the constant metal removal rate along the trajectory of the milling cutter during rough cutting process. In the finish cutting process of the die cavities, Design of Experiment Method has been employed to find out the effects of the cutting parameters on the geometrical accuracy of the manufactured cavity profile. Prediction formula is derived to estimate the geometrical error value in terms of the values of the cutting parameters. Validity of the prediction formula has been tested by conducting verification experiments for the representative die geometry and die cavity geometry of a forging part used in industry. Good agreement between the predicted error values and the measured error values has been observed.
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Radhakrishnan, Anupam. "Experimental and numerical investigation of subcritical bifurcations in milling". Diss., Columbia, Mo. : University of Missouri-Columbia, 2007. http://hdl.handle.net/10355/5095.
Testo completoAbstract (sommario):
Thesis (M.S.)--University of Missouri-Columbia, 2007.The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file (viewed on January 8, 2008) Includes bibliographical references.