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Technologie výroby součásti / Technology of production partStraka, Jiří January 2012 (has links)
This diploma thesis is developed within my Master’s degree studies, branch mechanical engineering (M21 K), and specialization in M STM. The aim of this thesis is to solve the technology of mechanical production (machining, tooling) for the machine component called ‚shape lid‘. I execute the analysis of this technology from the perspective of the conventional machining process, and alternatively, some of the non conventional machining process, too. Conventional machining process is so far used for manufacturing of this sort of machine’s element. It‘s implying laborious work difficulties, even it’s economically disadvantageous. I suggest a new technology of manufacturing. At first, a semi-finished component could be sized by conventional machining process, and then it could be finished by the CNC (computer numerical control) milling machine. By the non-conventional machining process assume the usage of an electro-erosive machining, plasma machining, or water jet machining.Conventional technology suppose the usage of CNC milling machines. Thereinafter, feasibility aspects of this brand new technology are considered in technical and economical perspective.
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Tepelně-vlhkostní analýza konstrukcí masivních dřevostaveb / Hygrothermal analysis of massive wooden structuresUherka, Pavel January 2016 (has links)
This thesis deals with massive wooden buildings especially with regard to the current approach to their design, assessment and approval. In this thesis are shown future possibilities of development of traditional wooden buildings with regard to current thermal technical requirements. Theoretical considerations are then compared with measurements which were performed on massive wooden wall samples.
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Výroba přírub s využitím postupu PPAP a normy ISO 9001 / Production of flanges using the procedure PPAP , and ISO 9001Prokeš, Tomáš January 2016 (has links)
In the first part of this thesis is described implementation of quality management system in a small company according to ISO 9001. Next part is about production process by method PPAP. In this section is solved primarily ISO 9001 standard, statistical control of production and certification company according to requirements of ISO 9001. Second part is focused on mass production of flange by using the company facilities Kovobrábění Sobotka. In the end of thesis are reflected weaknesses of production. In the conclusion is described technical and economic evaluation of implementation QMS and machining sample parts.
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Technologie frézování tenkostěnných součástí pro letecký průmysl / On the milling technology of thin-walled parts for aerospace industryOhnišťová, Petra January 2016 (has links)
This thesis is focused on the analysis and on the design of the milling technology of the components for the aerospace industry which are characterised by a high aspect ratio, reduced stiffness and all covered by a high demand on the fatigue performance. This work includes the experimental verification of the proposed technology using CNC machining center, evaluation of surface structure using optical high-resolution 3D surface measurement system ALICONA, analysis of the force loading using KISTLER device, fatigue testing and fatigue fracture analysis.
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Web Based Automatic Tool Path Planning Strategy for Complex Sculptured SurfacesPatel, Kandarp 07 June 2010 (has links)
Over the past few years, manufacturing companies have had to deal with an increasing demand for feature-rich products at low costs. The pressures exerted on their existing manufacturing processes have lead manufacturers to investigate internet-based solutions, in order to cope with growing competition. Today, the availability of powerful and low cost 3D tools, along with web-based technologies, provides interesting opportunities to the manufacturing community, with solutions directly implementable at the core of their businesses and organizations.
The wooden sign is custom i.e. each sign is completely different from each other. Mass Customization is a paradigm that produces custom products in masses. A wooden sign is custom in nature, and each sign must be completely different from another. Although process planning for mass customized products is same, the tool path required to CNC machine the custom feature varies from part to part. If the tool path is created manually the economics of mass production are challenged. The only viable option is to generate the tool path automatically; furthermore, any time savings in the tool path lead to better profit margins.
This thesis presents the automatic web-based tool path planning method for machining sculptured wooden sign on 3 axis Computer Numerical Controlling (CNC) Machines using optimal and cost-effective milling cutters. The web-based tool path planning strategy is integrate with web-based CAD system to automatically generate tool paths for the CAD model using optimal cutter within desired tolerances. The tool path planning method is divided into two parts: foot print (path along which cutter moves) and cutter positioning. The tool path foot print is developed during design stage from the CAD model based on the type of surface to be machined. The foot print varies from part to part which facilitates the mass customization of wooden sign. After designing foot print, the foot print is discretized into points and the gouge-free cutter position at each of these points is found using "Dropping Method". The Dropping Method where cutter is dropped over the work piece surface, and the highest depth at which cutter can go without gouging the surface is calculated. This is repeated for all the position along the foot print. This tool path planning strategy is developed for ball nose, flat-end and radiused end milling cutter for machining wooden sign.
The tool path generated using this method is optimized for machining time, tool path generation time and final surface finish. The bucketing technique is developed to optimize tool path generation time, by isolating the triangles which has possibility of intersection at particular position. The bucketing Technique reduced the tool path computation by 75 %, and made tool path generation faster. The optimal cutter selection algorithm is developed which selects best cutter for machining the surface based on the scallop height and volume removal results. The radiused end milling cutter results in highest volume removal which results in lower machining time compared to ball nose end milling cutters, but the scallop heights is higher. However, the scallop height in the radiused end milling cutter is higher only in few regions which reduces the final surface finish. For a sign, it was found around the boundary of logo, outline of lettering, interface of border and background. Thus, in order to achieve higher surface finish and lower machining time, a separate tool path is developed using "Pencil Milling Technique" which will remove the scallops from the regions that was inaccessible by radiused end mills. This tool path with the smaller cutter will move around the boundary of logo and lettering, and clean-up all the scallops left on the surface.
The designed tool path for all the three cutters were tested on maple wood and verified against the actual Computer Aided Design model for scallop height and surface finish. The numerical testing of tool path was carried out on a Custom Simulator, ToolSim and was later confirmed by actually machining on a 3 axis CNC machine. The same sign was machined with variety of milling cutters and the best cutter was selected based on the minimum scallop and maximum volume removal. The results of the experimental verification show the method to be accurate for machining sculptured sign. The average scallop height in a machined using 1/8 th inch radiused end milling cuter and using Pencil tool path on the machined surface is found to be 0.03989 mm (1.5708 thou).
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Development Of A Methodology For Prediction Of Surface Roughness Of Curved Cavities Manufactured By 5-axes Cnc MillingCelik, Kazim Arda 01 June 2007 (has links) (PDF)
The surface quality is identified by surface roughness parameters. The average surface roughness (Ra) is used in this study, as it is the most commonly used roughness parameter in the industry. A particular curved cavity of a forging die is selected for the experimental study. Different milling methods are tested. The comparison studies are conducted between 3-axes and 5-axes milling, linear and circular tool path strategies and down and up milling. According to the experimental study, appropriate method is determined for the milling of a particular curved cavity of a forging die.
The experimental analysis based on design of experiments (DOE) has been employed by considering cutting speed, feed per tooth and stepover parameters. Multiple linear regression technique is used by which a mathematical formula has been developed to predict the Ra values for milling parameters. The results of the mathematical formula are controlled by conducting test experiments and good correlations are observed between the results of the formula and the results of test experiments.
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Web Based Automatic Tool Path Planning Strategy for Complex Sculptured SurfacesPatel, Kandarp 07 June 2010 (has links)
Over the past few years, manufacturing companies have had to deal with an increasing demand for feature-rich products at low costs. The pressures exerted on their existing manufacturing processes have lead manufacturers to investigate internet-based solutions, in order to cope with growing competition. Today, the availability of powerful and low cost 3D tools, along with web-based technologies, provides interesting opportunities to the manufacturing community, with solutions directly implementable at the core of their businesses and organizations.
The wooden sign is custom i.e. each sign is completely different from each other. Mass Customization is a paradigm that produces custom products in masses. A wooden sign is custom in nature, and each sign must be completely different from another. Although process planning for mass customized products is same, the tool path required to CNC machine the custom feature varies from part to part. If the tool path is created manually the economics of mass production are challenged. The only viable option is to generate the tool path automatically; furthermore, any time savings in the tool path lead to better profit margins.
This thesis presents the automatic web-based tool path planning method for machining sculptured wooden sign on 3 axis Computer Numerical Controlling (CNC) Machines using optimal and cost-effective milling cutters. The web-based tool path planning strategy is integrate with web-based CAD system to automatically generate tool paths for the CAD model using optimal cutter within desired tolerances. The tool path planning method is divided into two parts: foot print (path along which cutter moves) and cutter positioning. The tool path foot print is developed during design stage from the CAD model based on the type of surface to be machined. The foot print varies from part to part which facilitates the mass customization of wooden sign. After designing foot print, the foot print is discretized into points and the gouge-free cutter position at each of these points is found using "Dropping Method". The Dropping Method where cutter is dropped over the work piece surface, and the highest depth at which cutter can go without gouging the surface is calculated. This is repeated for all the position along the foot print. This tool path planning strategy is developed for ball nose, flat-end and radiused end milling cutter for machining wooden sign.
The tool path generated using this method is optimized for machining time, tool path generation time and final surface finish. The bucketing technique is developed to optimize tool path generation time, by isolating the triangles which has possibility of intersection at particular position. The bucketing Technique reduced the tool path computation by 75 %, and made tool path generation faster. The optimal cutter selection algorithm is developed which selects best cutter for machining the surface based on the scallop height and volume removal results. The radiused end milling cutter results in highest volume removal which results in lower machining time compared to ball nose end milling cutters, but the scallop heights is higher. However, the scallop height in the radiused end milling cutter is higher only in few regions which reduces the final surface finish. For a sign, it was found around the boundary of logo, outline of lettering, interface of border and background. Thus, in order to achieve higher surface finish and lower machining time, a separate tool path is developed using "Pencil Milling Technique" which will remove the scallops from the regions that was inaccessible by radiused end mills. This tool path with the smaller cutter will move around the boundary of logo and lettering, and clean-up all the scallops left on the surface.
The designed tool path for all the three cutters were tested on maple wood and verified against the actual Computer Aided Design model for scallop height and surface finish. The numerical testing of tool path was carried out on a Custom Simulator, ToolSim and was later confirmed by actually machining on a 3 axis CNC machine. The same sign was machined with variety of milling cutters and the best cutter was selected based on the minimum scallop and maximum volume removal. The results of the experimental verification show the method to be accurate for machining sculptured sign. The average scallop height in a machined using 1/8 th inch radiused end milling cuter and using Pencil tool path on the machined surface is found to be 0.03989 mm (1.5708 thou).
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Contribuição ao estudo da prototipagem rápida, digitalização tridimensional e seleção de materiais no design de implantes personalizadosBertol, Liciane Sabadin January 2008 (has links)
O crescente aumento na expectativa de vida da população vem exigindo melhorias e atualizações a diversas áreas da ciência. Em decorrência disso, verifica-se que as fronteiras entre as diferentes áreas do conhecimento estão cada vez mais tênues, permitindo a sinergia entre as áreas e ações cooperativas, proporcionando melhorias significativas na resposta dada à sociedade em geral. Tal fenômeno ocorre na área relacionada a implantes ortopédicos, onde equipes de médicos, programadores, designers e engenheiros vêm desenvolvendo conjuntamente técnicas auxiliares de planejamento e execução cirúrgica, seleção de materiais adequados para utilização como implantes, softwares de visualização gráfica médica, design e fabricação de implantes personalizados, bem como a otimização dos mesmos. Tais medidas, realizadas por grupos interdisciplinares, representam grande avanço para a ciência e para a qualidade de vida da população. Neste sentido, o objetivo geral do presente trabalho foi o estudo das metodologias atualmente utilizadas para a obtenção de implantes personalizados para a reconstrução de defeitos craniofaciais. Buscou-se utilizar ferramentas da engenharia, design e computação gráfica para fornecer soluções para tais situações da área médica. Foram utilizadas técnicas de prototipagem rápida, sistema CAD/CAE/CAM, seleção de materiais, digitalização tridimensional a laser e softwares de visualização tridimensional de imagens médicas para o design e fabricação de implantes adaptáveis às necessidades individuais de cada paciente. Este trabalho estudou como os sistemas CAD/CAE/CAM e especialmente a prototipagem rápida, técnicas tradicionalmente utilizadas para aplicações industriais, podem contribuir para o aprimoramento de implantes ortopédicos. Foram estudados casos de diferentes pacientes com necessidade de reconstrução óssea facial decorrente de fraturas ou tumores. Seguindo o método tradicional de fabricação de implantes personalizados, modelos do crânio dos pacientes foram produzidos por prototipagem rápida e permitiram que os implantes fossem manualmente moldados para se adaptarem à estrutura anatômica do paciente em questão. Verificou-se a possibilidade de fabricação de implantes com alta complexidade geométrica, ocasionando melhora no posicionamento dos mesmos quando implantados, bem como redução no tempo de cirurgia. O método virtual de fabricação de implantes personalizados, estado da arte na área, foi utilizado para o design e fabricação de uma prótese de mandíbula. Tal método dispensou a utilização de modelos físicos do crânio do paciente, permitindo que a prótese fosse projetada em ambiente virtual e diretamente produzida no material adequado para ser implantado. As técnicas estudadas para a fabricação de implantes foram usinagem CNC seguida de moldagem, e sinterização seletiva a laser da liga Ti- 6Al-4V. Ambas as técnicas obtiveram resultados positivos, sendo que a usinagem CNC possui a vantagem de ser uma técnica largamente difundida no mercado. Os modelos produzidos por sinterização seletiva a laser apresentaram propriedades físicas adequadas para a aplicação (como densidade de 97%, por exemplo), além de possuírem vantagens intrínsecas à técnica, como a possibilidade de fabricação de modelos de grande complexidade geométrica, baixo peso (por possuírem vazios em seu interior), além de permitirem a fabricação de modelos otimizados, simulados previamente em ambiente virtual. / The increase in life expectancy of the general population is constantly demanding improvements and updates in different fields of the science. In this way, it is possible to observe that the borders among the different areas of the knowledge are very thin, leading to synergy between the areas and cooperative actions, resulting in improvements and better solutions for the problems of general society. This phenomenon occurs in the area related to orthopedic implants, where medical teams, programmers, designers and engineers develop together techniques to help on surgical planning and execution, selection of materials suitable for implantations, softwares for medical images, design and manufacturing of customized implants, as well as their optimization. These actions represent great improvements to science and to the life quality of the society. The objective of this work is to use engineering, design and computer graphic tools to give solutions for challenges in the medical field. Techniques such as rapid prototyping, CAD/CAE/CAM systems, material`s selection, three-dimensional laser scanning and medical softwares are used in order to design and manufacture customized orthopedic implants, suitable with the individual needs of each patient. This work investigated how CAD/CAE/CAM systems and rapid prototyping, techniques traditionally used for industrial applications, can help to improve orthopedic implants. Different cases of patients that needed facial reconstruction due to fractures or tumors were studied. According to the traditional method for production of customized implants, models of the patient skulls were manufactured through rapid prototyping, allowing to mould the implant directly on the physical model, so the implant could fit exactly in the patient`s anatomic structure. The feasibility of the manufacture of implants with high geometry complexity was also proved, leading to best fit of the implants in the patient during the surgery, as well as reduction of the surgery time. The virtual method for the production of customized implants, state of the art in the area, was used for the design and manufacturing of mandible prostheses. This method has no need of a physical model of the skull, making the design completely feasible in virtual environment and the model could be produced directly in the suitable material. The manufacturing technologies investigated were CNC milling and direct laser sintering of Ti-6Al-4V alloy. Both techniques presented positive results, and CNC milling has the advantage to be a very widespread technology. The models produced through direct laser sintering presented suitable physical properties (such as 97% density) and have some advantages intrinsic to the method, such as the feasibility of geometric complex models, light weight (because of the holes and pores inside), as well as the production of optimized structures, previously simulated in virtual environment.
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Contribuição ao estudo da prototipagem rápida, digitalização tridimensional e seleção de materiais no design de implantes personalizadosBertol, Liciane Sabadin January 2008 (has links)
O crescente aumento na expectativa de vida da população vem exigindo melhorias e atualizações a diversas áreas da ciência. Em decorrência disso, verifica-se que as fronteiras entre as diferentes áreas do conhecimento estão cada vez mais tênues, permitindo a sinergia entre as áreas e ações cooperativas, proporcionando melhorias significativas na resposta dada à sociedade em geral. Tal fenômeno ocorre na área relacionada a implantes ortopédicos, onde equipes de médicos, programadores, designers e engenheiros vêm desenvolvendo conjuntamente técnicas auxiliares de planejamento e execução cirúrgica, seleção de materiais adequados para utilização como implantes, softwares de visualização gráfica médica, design e fabricação de implantes personalizados, bem como a otimização dos mesmos. Tais medidas, realizadas por grupos interdisciplinares, representam grande avanço para a ciência e para a qualidade de vida da população. Neste sentido, o objetivo geral do presente trabalho foi o estudo das metodologias atualmente utilizadas para a obtenção de implantes personalizados para a reconstrução de defeitos craniofaciais. Buscou-se utilizar ferramentas da engenharia, design e computação gráfica para fornecer soluções para tais situações da área médica. Foram utilizadas técnicas de prototipagem rápida, sistema CAD/CAE/CAM, seleção de materiais, digitalização tridimensional a laser e softwares de visualização tridimensional de imagens médicas para o design e fabricação de implantes adaptáveis às necessidades individuais de cada paciente. Este trabalho estudou como os sistemas CAD/CAE/CAM e especialmente a prototipagem rápida, técnicas tradicionalmente utilizadas para aplicações industriais, podem contribuir para o aprimoramento de implantes ortopédicos. Foram estudados casos de diferentes pacientes com necessidade de reconstrução óssea facial decorrente de fraturas ou tumores. Seguindo o método tradicional de fabricação de implantes personalizados, modelos do crânio dos pacientes foram produzidos por prototipagem rápida e permitiram que os implantes fossem manualmente moldados para se adaptarem à estrutura anatômica do paciente em questão. Verificou-se a possibilidade de fabricação de implantes com alta complexidade geométrica, ocasionando melhora no posicionamento dos mesmos quando implantados, bem como redução no tempo de cirurgia. O método virtual de fabricação de implantes personalizados, estado da arte na área, foi utilizado para o design e fabricação de uma prótese de mandíbula. Tal método dispensou a utilização de modelos físicos do crânio do paciente, permitindo que a prótese fosse projetada em ambiente virtual e diretamente produzida no material adequado para ser implantado. As técnicas estudadas para a fabricação de implantes foram usinagem CNC seguida de moldagem, e sinterização seletiva a laser da liga Ti- 6Al-4V. Ambas as técnicas obtiveram resultados positivos, sendo que a usinagem CNC possui a vantagem de ser uma técnica largamente difundida no mercado. Os modelos produzidos por sinterização seletiva a laser apresentaram propriedades físicas adequadas para a aplicação (como densidade de 97%, por exemplo), além de possuírem vantagens intrínsecas à técnica, como a possibilidade de fabricação de modelos de grande complexidade geométrica, baixo peso (por possuírem vazios em seu interior), além de permitirem a fabricação de modelos otimizados, simulados previamente em ambiente virtual. / The increase in life expectancy of the general population is constantly demanding improvements and updates in different fields of the science. In this way, it is possible to observe that the borders among the different areas of the knowledge are very thin, leading to synergy between the areas and cooperative actions, resulting in improvements and better solutions for the problems of general society. This phenomenon occurs in the area related to orthopedic implants, where medical teams, programmers, designers and engineers develop together techniques to help on surgical planning and execution, selection of materials suitable for implantations, softwares for medical images, design and manufacturing of customized implants, as well as their optimization. These actions represent great improvements to science and to the life quality of the society. The objective of this work is to use engineering, design and computer graphic tools to give solutions for challenges in the medical field. Techniques such as rapid prototyping, CAD/CAE/CAM systems, material`s selection, three-dimensional laser scanning and medical softwares are used in order to design and manufacture customized orthopedic implants, suitable with the individual needs of each patient. This work investigated how CAD/CAE/CAM systems and rapid prototyping, techniques traditionally used for industrial applications, can help to improve orthopedic implants. Different cases of patients that needed facial reconstruction due to fractures or tumors were studied. According to the traditional method for production of customized implants, models of the patient skulls were manufactured through rapid prototyping, allowing to mould the implant directly on the physical model, so the implant could fit exactly in the patient`s anatomic structure. The feasibility of the manufacture of implants with high geometry complexity was also proved, leading to best fit of the implants in the patient during the surgery, as well as reduction of the surgery time. The virtual method for the production of customized implants, state of the art in the area, was used for the design and manufacturing of mandible prostheses. This method has no need of a physical model of the skull, making the design completely feasible in virtual environment and the model could be produced directly in the suitable material. The manufacturing technologies investigated were CNC milling and direct laser sintering of Ti-6Al-4V alloy. Both techniques presented positive results, and CNC milling has the advantage to be a very widespread technology. The models produced through direct laser sintering presented suitable physical properties (such as 97% density) and have some advantages intrinsic to the method, such as the feasibility of geometric complex models, light weight (because of the holes and pores inside), as well as the production of optimized structures, previously simulated in virtual environment.
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Implementação e análise de um retrofitting aplicado em uma máquina de 3 eixosPeixôto, Wagner Correia 26 February 2016 (has links)
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Previous issue date: 2016-02-26 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / The computer numerical control machine tools, or CNC machine tools, emerged due to
the need of the aviation industry to produce increasingly complex and accurate parts. The
retrofitting of machine tools is the modification of a traditional machine for a computer
numerical control one. Due to the popularization of computers, electronic components
decreased costs, Internet expansion and open source projects, the retrofitting has become
increasingly widespread in industry as an option for the purchase of new machine tools
with CNC included. The objective of this study was to implement the retrofit on a 3-axis
machine from the Precision Engineering Laboratory of the Federal University of Paraíba.
For this adaptation, the machine has been modified to use a kit with interface drivers from
HobbyCNC and new stepper motors. After the retrofit, it used a 80-XL Laser system for
measuring position errors. The tests were performed on each axis, commanding the
machine to five positions and measuring the actual positions reached and, then, the same
tests were carried out in reverse direction. With the measured results, the positioning
errors, hysteresis, repeatability and accuracy calculated by ISO 230-2 standard. It was
conducted other tests in compensating the previously measured errors on the Y axis.
There was a significant improvement on the Y-axis accuracy after compensation. Also,
angular errors tests were carried out, with the use of an electronic level Talyvel 5, along
the axis Y. The results of the test were satisfactory and the retrofitting reached its
expectations, providing the possibility of further research in the area of numerical control. / As máquinas-ferramentas com controle numérico computadorizado, ou máquinasferramentas
CNC, surgiram devido à necessidade da indústria da aviação para produzir
peças cada vez mais complexas e precisas. O retrofitting de máquina-ferramenta é a
modificação de uma máquina tradicional para uma com controle numérico
computadorizado. Devido à popularização dos computadores, diminuição de custos dos
componentes eletrônicos, expansão da Internet e projetos de código aberto, o retrofitting
tornou-se uma opção cada vez mais comum na indústria como alternativa para a compra
de novas máquinas-ferramentas com CNC incluso. O objetivo deste estudo foi a
implementação do retrofitting em uma máquina de 3 (três) eixos no Laboratório de
Engenharia de Precisão da Universidade Federal da Paraíba. Para essa adaptação, a
máquina foi modificada para utilizar um Kit com drivers de interface da HobbyCNC e
novos motores de passo. Após o retrofitting, foi utilizado um sistema Laser XL-80 para
medição dos erros de posicionamento. Os testes foram realizados, em cada eixo,
comandando-se a máquina para 5 posições e medindo-se as posições reais atingidas e,
depois, foram realizados os mesmos testes no sentido inverso. Com os resultados
medidos, são calculados os erros de posicionamento, histerese, repetitividade e exatidão
conforme a norma ISO 230-2. No eixo Y foi realizado outros testes com a compensação
dos erros medidos anteriormente. Houve uma melhora significativa na exatidão do eixo
Y após a compensação. Também foram realizados testes de erros angulares, com a
utilização de um nível eletrônico Talyvel 5, ao longo do eixo Y. Os resultados obtidos no
teste foram satisfatórios e o retrofitting atingiu suas expectativas, por proporcionar a
possibilidade de realizar mais pesquisas, na área de Comando Numérico
Computadorizado.
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