Orientador: Nivaldo Lemos Coppini / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecanica / Made available in DSpace on 2018-07-22T10:58:08Z (GMT). No. of bitstreams: 1 Costa_DalbertoDiasda_D.pdf: 7963439 bytes, checksum: ab345a526734ea426844161892948326 (MD5) Previous issue date: 1997 / Resumo: A determinação das condições de usinagem raramente tem sido contemplada como um problema de planejamento, e, portanto, integrada às outras etapas. Observa-se que essa determinação vem sendo tratada isoladamente, como um problema de pesquisa operacional (otimização de uma função objetivo) ou como uma simples consulta a um banco de dados. Em muitas situações, ela é deixada a cargo de um operador experiente. O objetivo deste trabalho foi formalizar uma metodologia para construção de uma ferramenta computacional que permita a um especialista humano gerar um sistema para enfrentar esse problema. A presente metodologia tem um caráter generalista, permitindo ao usuário obter um sistema que contenha sua experiência pessoal e seja dirigido pelo e para um determinado chão-de-fábrica. Para atingir esse objetivo empregou-se as seguintes técnicas: propagação de restrições, raciocínio baseado em casos e raciocínio qualitativo-causal. A metodologia proposta já se encontra na forma de um protótipo implementando em VISUAL-BASIC e COMMON LISP; sendo possível a construção de um Módulo Especialista para escolha das condições de corte paralelamente às outras etapas do planejamento da usinagem / Abstract: The selection of cutting conditions is an important task in the machining planning. It affects time, cost, quality and always yields undesirable side-effects as excessive tool wear and large cutting forces. However, there is a few attempt to integrate it in the automated process planning systems. Probably, because there is no theoretic models to allow theirs values to be selected. The presence of experimented personnel remains necessary to choose the initial conditions and change them when something goes wrong at the shop fIoor. The purpose ofthis research is an attempt to face this problem. A very general methodology was proposed. Constrain propagation, similarity evaluation and qualitative-causal models were the techniques employed to formalize this proposal. Constraints were used as a medium forcommunication among hierarchical levels of variables. Similarity coefficients were fundamental to retrieve past experience from a case base. The causal dependency between variables were expressed using qualitative relations, which allowed to adapted the retrieved case to satisfy the most important constraint. The current methodology - implemented using VISUAL-BASIC and COMMON LISP - permits an Expert Module to be tailored to a very specific shop fIoor and the choice of cutting variables can be made concurrently with the others planning tasks / Doutorado / Materiais e Processos de Fabricação / Doutor em Engenharia Mecânica

This diploma thesis deals with machining process of shaft in the company Decoleta, a.s. to propose production efficiency improvement. The first part of the diploma thesis is focused on the description of the company's activities and analysis of the used machining technologies. The second part analyses the actual production process and proposes increase in efficiency of the component’s production. In the final part the thesis compares the current and upgraded state of machining processes and includes a technical-economical evaluation of the proposed modifications.

The dissertation is focused on the bearing production technology issues. The aim of the thesis is to investigate and evaluate the influence of the technological processes on properties of the functional surfaces of an outer bearing ring. The development, rolling, grinding and turning have been selected as basic technological processes. The subject of the surface integrity research on test samples is the measurement and analysis of the quality of the machined surfaces and residual stresses in the surface layers of the bearing rings. The comparison is made in relation to the previous operations - rolling, turning and grinding.

This master‘s thesis deals with optimization of cutting conditions when machining of precise parts in mass production. In experimental part of this thesis is a comparison of the roughing tool with indexable cutting inserts with the new implemented milling cutter. Tool wear of both roughing tools has been analysed. The surface roughness analysis after machining with the face milling cutter was performed. The output of this work is to obtain optimal cutting conditions to gain a minimum surface roughness.

The master`s thesis deal with analysis of machining technology of the bolt from the superalloy Ni80TiAl for the company Sanborn a.s. The aim of the thesis is the project of new technology by usage of new tool, indexable inserts and cutting conditions. The results are speedup of the roughing operation, reduction of the manufacturing cost and the product price.

Diploma thesis is specialized to solving of problems machining of diffi-cult machinable materials. There is carried out the analysis of difficult machinable materials in term of chemical composition, physical and mechanical properties. In the following it deals with analysis of machining, specification of geometry, material of cutting tools and cutting conditions.

This study states basic technological aspects of metal machining with cutting inserts, with special stress on coated carbide cutting inserts. Among others, it states wear-out theory incl. wear-out accompaniments, problems of chip-forming and other factors of metal machining. At the end of the study, it contents a description of the latest cutting materials and construction elements of cutting inserts from reputable producers and, for some of them, also the course and the results of practical tests and comparison.

This thesis deals with cermets as a tool material. In the Preamble, the types, production, labeling and properties of cermets are analyzed. The main part of the thesis introduces cermets in the range of manufacturing by the world leading producers of tools and tool materials. The Conclusion of the thesis summarizes the evaluation of tool cutting abilities and recommended working conditions guaranteeing the efficient use of cermets.

A general analysis of machining problems, analysis of cutting forces for turning, milling, drilling. Evaluation of experimentally measured values of surface structure and theoretical values of cutting forces in turning cylindrical parts. Economical processes for the comparable results of the final state of the surface.

The current processing of electric motor feet and centering collars has been focusing on two main production methods. The production transfer from Germany allowed the introduction of a new enhanced technology. Cutting conditions values, cutting process operating forces , tool life criteria for a maximum productivity and a minimum costs were calculated. Control measurements of the required collar and stator pack concentricity provided the necessary feedback.