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  • 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.
71

Proposta de método de referência aplicado a retrofitting de máquinas-ferramentas / Proposal for a reference method applied to the retrofitting of machine tools

Silvio Luiz Plotegher 18 December 2012 (has links)
A obsolescência das Máquinas-Ferramentas (MFs) é um processo natural de envelhecimento neste tipo de equipamento. Esse processo compreende uma série de degradações tecnológicas, os quais se instalam e ocorrem em toda estrutura física de uma MF, independentemente da tecnologia utilizada. As degradações podem, no entanto, ser resultantes de vários fatores, como uso, aplicação, regime de trabalho, dentre outros. Os aspectos tecnológicos ficam mais evidentes quando se analisam as máquinas a Comando Numérico Computadorizado (CNC). Por sua vez, o CNC é um equipamento que apresenta uma evolução constante, mas que muitas vezes não pode ser facilmente incorporado às máquinas já existentes sem um processo de retrofitting anteriormente definido. Um processo de retrofitting pode ser considerado como um processo que permite aplicar incrementos tecnológicos em uma MF. Mais recentemente, diversos estudos têm apresentado tendências que fazem uma ligação entre MFs e sustentabilidade, sem, no entanto, definir ou propor modelos. Estudar os aspectos do comportamento das MFs existentes e poder aplicar recursos das novas tecnologias pode contribuir para melhorar os aspectos de sua produtividade e, por conseguinte, contribuir para uma produção mais sustentável. No entanto, isso deve ser feito a partir de uma metodologia que oriente um processo de tomada de decisão. Dessa forma, este trabalho propõe um método de referência aplicado a retrofitting de máquinas a partir da definição de coeficientes e de índices numéricos cujos resultados atuam como ferramenta orientativa a um processo de tomada de decisão. O método é aplicado a diversos tipos de MFs e os resultados indicam a viabilidade ou não de um retrofitting. / The obsolescence of Machine Tools (MT) may be defined is a natural process of aging in this type of equipment. This process comprises a series of technological degradation, which settles and occurs across the entire and physical structure of a MT, regardless of the technology used. The degradations may, however, be due to several factors such as usage, application, machining process and so on. The technology aspects are more evident when analyzing the machines Computerized Numerical Control (CNC). By the other hand the CNC is an equipment which naturally contributes with a constant evolution, but they often cant be easily incorporated into an existing machine without a procedure for retrofitting previously defined. A process of retrofitting can be defined and considered as a process incorporates technology resulting in increments of technology to a MT. However, the addressing of such process is usually applied without any models or tools within a process of decision making. More recently, several studies have shown trends making a connection between MT and sustainability without, however, defining templates for such process. The studies of all aspects of the behavior of an existing MT, even with its limitations, suggest the resources of new technologies can help to improve in general all aspects of their productivity and therefore contribute to a more sustainable production. However, this must be done from a methodology that guides the process of decision making. This decision process represents a process that results from a technological gain in a MT or not. Thus, this work proposes a reference method applied to retrofitting machines by defining a series coefficients and numerical indices whose results intends to be used as a tool for helping a decision-making process.
72

Arquiteturas para monitoramento e supervisão integrados de processos de usinagem em máquinas com controle numérico aberto / Integrated monitoring and supervision architectures applied to machining process controlled by open CNC systems

Fábio Ferraz Júnior 14 August 2007 (has links)
Empreendimentos industriais requerem o completo e preciso acompanhamento de dados de máquinas em tempo real, integrando as atividades do chão de fábrica com a engenharia, suporte e de negócios. É reconhecido que sistemas de monitoramento são fundamentais para melhorar a qualidade do produto, reduzir os tempos e para a adaptação rápida às mudanças de produção. Os sensores de processos possuem altos custos, não são compactos e são de difícil implementação. Portanto, seria estratégico desenvolver sistemas de monitoramento que utilizem ao máximo os recursos já existentes nas máquinas ferramentas e que não representem custos adicionais de implementação. O uso de CNC´s de arquitetura aberta nas indústrias é crescente. Estes se mostram como potenciais ferramentas para atender a estas exigências. Possuem os recursos necessários para a aquisição de informações administrativas e tecnológicas e para o desenvolvimento de sistemas de monitoramento. O objetivo do presente trabalho é pesquisar arquiteturas de monitoramento e supervisão para processos de usinagem que tenham como base informações disponíveis em CNC´s de arquitetura aberta. Tais sistemas, apesar de todo o potencial existente, ainda não tem sido explorados nem desenvolvidos adequadamente para os processos de usinagem. O presente trabalho é multidisciplinar nas áreas de automação e usinagem. Está dividido em partes em que são analisados tanto os elementos tecnológicos dos CNC´s abertos, bem como os processos de monitoramento e supervisão da usinagem. São apresentadas propostas no sentido de integrar as duas áreas pelo desenvolvimento de arquiteturas de software dedicadas. Os sistemas desenvolvidos foram testados em laboratório e também nas empresas parceiras. Os resultados mostram que o uso de CNC´s abertos para monitoramento e supervisão de processos é viável e proporciona funções de monitoramento/supervisão que não eram possíveis com os sistemas convencionais e sem a necessidade de recursos adicionais, como hardware, sensores e instalação. A implementação de protótipo em empresa parceira foi bem sucedida e deverá ser expandida no futuro. / Manufacturing enterprises require complete real time and accurate monitoring of machine tool data for integrating the shop floor with other company activities, as engineering, maintenance and business. It is acknowledged that monitoring systems capabilities are unavoidable to improve product quality, to reduce production time, and to the rapid adaptation in the changes of production. The use of external sensors gives high costs and do not have the advantages of compactness and the ease of use. Therefore, it is extremely advantageous to develop monitoring systems maximizing the use of the resources already existent in the machine tools and without additional costs of implementation. The use of open CNC\'s on industries is growing. This kind of control has been a great tool to attend these present requirements. It has the necessary resource to get managerial and technological information, and to develop monitoring systems. The objective of this work is to research monitoring and supervision architectures for machining process, based on information already available in open CNC\'s. Such systems, in spite of the whole existent potential, have not still been explored nor developed appropriately for the machining processes. The present work is multidisciplinary in the automation and machining areas. It is divided in parts where the technological elements of open CNC\'s are analyzed, as well as the monitoring and supervision systems of the machining processes. An architecture is proposed in the sense of integrating both monitoring and supervision. The developed systems were tested in laboratory and also in the partner companies. The results show that the use of open CNC\'s for monitoring and supervision of processes is viable and provides monitoring/ supervision functions which were not possible with the conventional systems and without the need of additional resources, as hardware and sensor installation. The prototype tested in a partner company succeeded and should be expanded in the future.
73

COMPARAÇÃO DE DESEMPENHO ENTRE PROGRAMAS CNC PARAMÉTRICOS E GERADOS POR SISTEMA CAM. / PERFORMANCE COPARISON BETWEEN PARAMETRIC PROGRAMS AND A CAM SYSTEM

Melegari, Luis Fernando 15 December 2011 (has links)
The use of CAM system to create tool s trajectories in outline of simple geometry depends directly of knowledge and ability from user in how to maintain the information and make use of available riches from these systems. The parametric program requires a solid knowledge in CN programming and the results referring to CNC machine s performance are directly connect to the way of programming to obtain these results. The aim of this study was to develop a practice s analysis between parametric program and a CAM system in a specific CNC machine, based on acting time and speed of tool s progress to each programming method. The counting of time was accomplished through CNC controller, which shows the execution time of each program from its beginning until receiving or reading the stop command. The comparison between these programming methods created results that depend of the programming way, but who receive interference of controller s technologies recourses to put in action the CNC axis machine. With these testing, it was possible to demonstrate, by means of parametric programs, an increase of 65% in performance, when compared to other programming methods. / A utilização de sistemas CAM para a geração de trajetórias de ferramenta em contornos de geometria simples depende diretamente do conhecimento e da capacidade do usuário na alimentação das informações e na utilização dos recursos disponíveis desses sistemas. A programação paramétrica exige uma base sólida no conhecimento da programação CN e os resultados que se referem ao desempenho da máquina CNC estão diretamente ligados à forma de programação para a obtenção desses resultados. O objetivo deste estudo foi desenvolver uma análise de desempenho entre a programação paramétrica e um sistema CAM em uma máquina CNC específica, com base nos tempos de execução e velocidade de avanço da ferramenta para cada método de programação. A contagem de tempo foi realizada através do controlador CNC, que indica o tempo de execução de cada programa a partir do seu início até o recebimento ou leitura do comando de parada. A comparação entre esses métodos de programação gerou resultados que dependem diretamente da forma de programação, mas que recebem interferência dos recursos tecnológicos do controlador para o acionamento dos eixos da máquina CNC. Com essas experimentações, foi possível demonstrar, através de programas paramétricos, um aumento no desempenho em até 65% quando comparado a outros métodos de programação.
74

Racionalizace výroby součásti zemědělského stroje / On the production of an agricultural machinery part and its optimization

Tenora, Tomáš January 2017 (has links)
This master's thesis deals with the process of machining a forged connecting rod in cooperation with the company Zetor Tractors a.s. The first chapter of the thesis is focused on a detailed introduction of the company. The second chapter includes an elaborate analysis of the technical documentation and requirements concerning the making process of the subject of study, specifically the construction of the connecting rod. In the third chapter, the current production technology is discussed and described in detail. The aim of the fourth chapter is to propose an innovative technology which can be used for the production of connecting rods in the required quality. The fifth chapter is aimed at testing the newly designed technology. In the final, sixth, chapter, a technical and economical evaluation of the proposed procedure is performed.
75

Návrh CNC modelářské frézky pro opracování hliníkových slitin / Design of a CNC modeling milling machine for machining aluminum alloys

Čechman, David January 2019 (has links)
The goal of the thesis is to design a modeling CNC milling machine for machining of aluminum alloys including necessary calculations and drawing documentation. In the first part there is defined a CNC milling machine and there is a search in the area of small CNC milling machines that are present on the market. In the second part is the design including the computational documentation.
76

Design CNC vertikálního soustruhu s průměrem upínací desky 2500 mm / Design of CNC vertical lathe with table diameter 2500 mm

Eliášová, Eva January 2020 (has links)
The topic of this work is the design of a vertical lathe with a table diameter of 2,500 mm. Part of the work is the analysis of current products in order to solve their shortcomings. The result is an innovative design focused on user-friendly operation and progressive shaping. At the same time, the designed machine fulfils all technical, ergonomic and aesthetic requirements.
77

Modernizace řídícího CNC systému frézky EMCO / The modernization of CNC system of milling machine EMCO

Kučera, Vítězslav January 2020 (has links)
This master´s thesis deals with the modernization of the EMCO milling machine control system. The theoretical part is focused on the basic description of CNC machine and current state of EMCO milling machine control system. The main point of this thesis is new control system design for given milling machine, when the proposed variants are described and compared according to construction and price. The one variant is selected that best suits the specified parameters. Also, in the TwinCAT development interface from Beckhoff the new control system is created and described in the end of this work.
78

Model CNC frézky / Model of CNC milling machine

Kovář, Pavel January 2012 (has links)
The master's thesis deals with the basic parts and principles of CNC machines with a focus on a CNC milling machine. There are also comparisons of several CNC machines sold. Furthermore, the project deals with the description of the manipulator, which is situated in laboratory E-132 in area Kolejní 4, Brno. The work also includes a description of the device, which is located in the manipulator model. We can find there a description of the program generating G-code from the image that you create in the editor. The next section describes possible modifications of the manipulator for its reconstruction on a CNC milling machine. The last chapter deals with the description of program developed for controlling the manipulator as a CNC milling machine.
79

Návrh manipulačního systému s roboty pro CNC obráběcí linku / Design of robotic handling systém for CNC production line

Loudát, Pavel January 2008 (has links)
The aim of this thesis was to design the robotic handling system of CNC production line based on requirements of Valeo Compressor Europe in Humpolec. The theoretical part of this thesis includes the profile of the company, analysis of handling system and automated workstations used in production system. The practical part of this thesis includes analysis of the current state and design of handling system for CNC production line. There is recovery of investment analysis for the designed line and summary at the last part of diploma project.
80

Aplikace CAD/CAM softwaru PowerMILL 6.0 při 3D obrábění. / Application CAD/CAM software PowerMILL 6.0 for 3D machining.

Vinkler, Tomáš January 2009 (has links)
The diploma thesis contains detailed processing of a two-piece car form by means of possible accessible 3D strategies of CAM system PowerMILL, selecting of tools, economical evaluation and creation of NC program for CNC machining centre.

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