• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 27
  • 12
  • 11
  • 3
  • 1
  • 1
  • 1
  • 1
  • 1
  • Tagged with
  • 65
  • 65
  • 20
  • 20
  • 19
  • 18
  • 17
  • 13
  • 12
  • 12
  • 11
  • 10
  • 9
  • 9
  • 8
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
21

Estudo da usinabilidade de chapas MDF (Medium Density Fiberboard) para usinagem de desbaste e acabamento / not available

Eduardo Martins de Castro 28 February 2000 (has links)
Este trabalho apresenta estudos de usinabilidade de chapas MDF (Medium Density Fiberboard), tendo por objetivo principal efetuar uma análise do desempenho de corte em relação à qualidade da superfície usinada e à força específica de corte paralela necessária, a fim de se verificar a influência dos parâmetros estudados para operações de usinagem de acabamento e desbaste, respectivamente. No estudo para operação de acabamento verificou-se a influência da espessura de corte,velocidade de avanço e sentido de corte, em operação de fresamento cilíndrico periférico, sobre a rugosidade superficial da borda das chapas MDF. Uma fresadora vertical foi utilizada para gerar as superfícies, cuja rugosidade superficial foi medida por um perfilômetro de apalpamento. No estudo para operação de desbaste, a força específica de corte paralela foi avaliada em função da variação do ângulo de saída, da espessura de corte e da profundidade de corte, em operação de corte ortogonal. Para tanto, foram empregadas uma plaina limadora e uma célula de carga de extensômetros resistivos, conectada a um programa de aquisição e análise de dados. A partir da análise dos resultados obtidos, foi possível identificar a influência de cada parâmetro de corte empregado. / This work presents a MDF (Medium Density Fiberboard) machinability study aiming to carry out a cutting performance analysis regarding to surface quality and parallel specific cutting force, in order to verify the cutting parameters effect on the finishing and roughing machining operations, respectively. In the finishing study, it was verified the effect of the cutting thickness, cutting speed and direction of cutterhead rotation with relation to feed direction, in peripheral milling, on the MDF edges surface roughness. The surfaces were developed by a moulder, which roughness were measured by a stylus perfilometer. In the roughing study, the parallel specific cutting force was assessed in relation to the variation of the rake angle, cutting thickness and depth of cut, for the orthogonal cut. For this, it was used a planing machine and a resistance dynamometer, coupled in a data acquisition and analysis system. From the analysis of the obtained results, it was possible to identify the influence of each cutting parameter considered.
22

Undersökning av sågars skäregenskaper och praktisk jämförande testning : med handsågar för beskärning i växande träd / Cutting properties and comparative testing of saws : with manual pruning saws for living trees

Mellqvist, Daniel January 2020 (has links)
Föreliggande arbete syftade till att genom praktiska försök och teoretiska studier länka samman beskärningssågars effektivitet med dess biologiska påverkan av det växande trädet. Med målet att skapa en kunskapsgrund vid utveckling av nya sågar för trämaterial. Inom studien har en testutrustning använts för att provsåga tre kommersiellt tillgängliga beskärningssågar i två skilda trädslag. De uppkomma sågytorna analyserades med hjälp av optiska metoder. Resultaten från de praktiska sågförsöken och de påföljande optiska undersökningarna länkades till trädets biologiska reaktion på beskärning. Studien belyste ogynnsamma kraftförhållanden samt beskärningssågarnas inverkan på det levande trädet. Under studiens gång har även talrika uppslag för vidare undersökningar identifierats och definierats.
23

Obrábění vulkanizačních forem z hliníkových slitin / Machining of vulcanizing molds from aluminum alloys

Kaška, Zdeněk January 2020 (has links)
This diploma thesis is focused on the issue of deep drilling of vulcanization molds from various aluminum alloys. The work will describe a brief description of machined materials and tools for deep drilling, including the production of the vulcanization mold itself. Based on experimental measurements, the analysis of data and knowledge gained from deep drilling of aluminum alloys with different silicon contents will be performed. In the end, the individual components of force loads for both machined materials will be compared
24

Konstrukce portálové frézky / Design of gantry-type milling machine

Mikulová, Michaela January 2011 (has links)
This master´s thesis deals with gantry – type milling machines. At first gantry – type milling machines are divided according to their structure. Then basic parts of an upper gantry – type milling machine are described. This machine is designed in a calculation part of this thesis. A calculation of a cutting force, a calculation of a needed moment of a drive of a spindle and a feed screw for axis x, y, z, a design of a belt drive between the spindle and the drive are done in the calculation part. Then the model of this upper gantry – type milling machines is made. Drawings are created for some parts of this machine.
25

Výroba ohýbaného profilu sdruženým nástrojem / The bend profile manufacturing by combination dies

Kummer, Michal January 2011 (has links)
This diploma thesis describes the creation of the technological process for shelf clutch production. The shelf clutch will be made of material 11 321 by cutting and bending technologies. The first part of thesis includes the theoretical description of cutting and bending technologies. The second part contains calculations and design proposal of final combined cutting and bending tool and also selection of pressing machine. The thesis contains the unit block layout of the combined cutting and bending tool and detailed drawings of cutting and bending parts of the tool. The shelf clutch drawing is included too.
26

Obrábění žáruvzdorných keramických materiálů frézováním / On the milling of refractory ceramic materials

Reiter, Milan January 2014 (has links)
Diploma thesis is focused on machining of refractory ceramics materials. The theoretical part describes the division of ceramics materials, their structure, manufacture and properties. This part also contains the division of refractory ceramics. In the second chapter, of ceramics materials are described machining. The latest chapter is focused on analyzing the machinability of ceramics materials R - SLI - K. During the experiment, cutting conditions were changed and cutting forces were checked. Then surface roughness was measured and tool wear was observed.
27

Silové zatížení řezných nástrojů při frézování / Force load of the cutting tools in milling

Vašíček, Jiří January 2014 (has links)
The thesis is focused on measuring the power equipment for milling. The theoretical part describes the method of measuring forces with a deeper focus on the individual meter. There is also the description of the characteristics of the milling process. Experimental part is focused on the proposal of experiment of the face milling, its implementation and subsequent evaluation.
28

Výroba držáku magnetu / Production of the magnet holder

Kraval, Jiří January 2016 (has links)
This project developed within the engineering studies of M-STG submits a proposal of a production technology of production of the magnet holder made of DC03. Based on a literary study of the problem of cutting, drawing, bending and calculations manufacturing of the component in a production die was suggested. The production die uses a normalised component and is tightened on PE 100 crank press with nominal drawbar pull 1000 kN. The conclusion of the thesis deals with the economic benefit of the suggested manufacturing technology.
29

Frézování tenkostěnných součástí pro letecký průmysl / Milling of Thin-Walled Parts for Aircraft Industry

Chuvashev, Anton January 2016 (has links)
This diploma thesis deals with issues in machining of thin-walled components. Its first part describes materials used in the aircraft industry. Then it focuses on issues associated with the prediction of deflections of a rib wall during machining. Later on it focuses on different methods and strategies of thin-walled part milling. The diploma thesis also describes an experiment of manufacturing thin-walled components in the form of ribs and evaluation parameters such as roughness, perpendicularity and straightness deviations, width of the rib and force loading of a cutting tool as measured by various gages. The final part is devoted to a calculation of the specific cutting force and its comparison with its theoretical value.
30

Optimization of cutting parameters in machining of Compacted Graphite Iron (CGI)

Berhane, Mulugeta January 2011 (has links)
Compacted Graphite Iron offers mechanical properties in between of gray cast iron and ductile iron. Thus,the material is seen as a hopeful alternative for engine cylinder blocks and heads satisfying environmentaland performance objectives. Nevertheless, CGI is more difficult to machine than conventional gray castiron due to the presence of MnS and thin wall section of probing high strength. This problem of CGI thenled to the initiation of large Optima Sweden project to study machinability and optimization of related toCGI.The thesis is centered on a study of tool life, cutting force and MRR with regards to machining parametersmainly feed rate and cutting speed for CGI milling. Tool life is measured; flank-wear is observed andcompared between several combinations of cutting parameters.Similarly cutting forces were measured using LMS software for full factorial design experiments. Extensivemachining experiments were carried out. Machining tests was done based on Design of Experiment (DoE)for high cutting data and lower data are performed separately. Comparison is made for tool life and cuttingforces. After data collection, analysis of tool life and force has been followed. Once the data is analyzedand checked its consistency. An approximate model is developed using MODDE software. Further, multiobjective optimization of tool life and Material removal rate (MRR) using cutting parameters mainly feedrate and cutting speed are investigated. Working on optimal parameters will allow for CGI is to becompetitive in manufacturing with gray CI, aluminum alloy, magnesium.Keywords: Compacted Graphite Iron (CGI), face milling, tool life, MRR, optimization, cutting force

Page generated in 0.0827 seconds