Calibração indireta de erros geométricos em torneamento cilíndrico associada a técnicas de ferramentas da qualidade: uma contribuição para a qualidade de fabricação
Data
2023-06-21
Autores
Cristo, Luiz Motta
Título da Revista
ISSN da Revista
Título de Volume
Editor
Universidade Estadual Paulista (Unesp)
Resumo
Os processos convencionais de usinagem são um dos principais métodos para fabricação de peças em diversos setores da indústria. No entanto, como todo processo, existem variações no processo de fabricação oriundas de diversas fontes. Entre elas, erros geométricos podem representar entre 40% e 70% de todos os erros de uma máquina ferramenta. Sendo assim, é preciso controlar esse tipo de erro para que as tolerâncias estabelecidas para a fabricação de uma peça não sejam ultrapassadas. Diante do exposto, esse trabalho tem como objetivo investigar o erro geométrico de posicionamento na direção transversal ao longo das guias do carro longitudinal da máquina ferramenta estudada através da obtenção de dados quantitativos a fim de mensurar o desvio e, com isso, utilizar as ferramentas da qualidade 5S, Fluxograma, Folha de Verificação, Histograma, Análise de Pareto e Diagrama de Ishikawa para padronizar, identificar fatores influenciadores e observar a distribuição dos erros e, com isso, identificar as regiões com os maiores erros e propor métodos de compensação para o erro encontrado. Para isto, foi utilizado como objeto de estudo um torno horizontal mecânico e, como equipamentos para obtenção dos dados, uma coluna de medição, um apalpador indutivo, um suporte magnético com braços hidráulicos articulados e um artefato de aço 1045 com tratamento térmico de oxidação negra e faces de medição retificadas. Com esses equipamentos, foram realizadas as medições na direção longitudinal do barramento, em três posições transversais diferentes, a fim de simular condições diferentes de usinagem de peças com comprimentos e diâmetros. Com os dados das medições, é necessário eliminar o desalinhamento do artefato com faces retificadas para obter os valores do erro de posicionamento na direção transversal das guias do carro longitudinal. Uma vez conhecido esse erro, as ferramentas da qualidade são aplicadas e, com as compensações propostas a partir de seus resultados, identificamos os melhores resultados para cada aplicação. Com o estudo feito, foi identificado que o método que apresentou os melhores resultados de compensação foi a partir dos dados obtidos através do Histograma. Além disso, foi determinado a importância das ferramentas da qualidade para este trabalho, uma vez que, através delas foi possível padronizar e organizar o fluxo de montagem dos equipamentos de medição para evitar variações, pôde ser identificado a incidência dos erros dentro de determinados intervalos e, a partir disso, conhecer as medidas longitudinais com os maiores erros transversais e propor compensações baseado nos valores encontrados. Por fim, também foi identificado os fatores externos que podem ter influenciado na coleta de dados.
Conventional machining processes are one of the main methods for manufacturing parts in many sectors of industry. However, like any process, there are variations in the manufacturing process from various sources. Among them, geometric errors can represent between 40% and 70% of all errors in a machine tool. Thus, it is necessary to control this type of error so that the tolerances established for the manufacture of a part are not exceeded. Given the above, this work aims to investigate the geometric error of positioning in the transverse direction along the guides of the longitudinal carriage of the machine tool studied by obtaining quantitative data in order to measure the deviation and thus use the quality tools 5S, Flowchart, Check Sheet, Histogram, Pareto Analysis and Ishikawa Diagram to standardize, identify influencing factors and observe the distribution of errors and thus identify the regions with the largest errors and propose methods of compensation for the error found. For this, it was used as study object a mechanical horizontal lathe and, as equipments to obtain the data, a measuring column, a inductive probe, one magnetic support with articulated hydraulic arms and a 1045 steel artifact with black oxidation and rectified measuring faces. With this equipment, measurements were taken in the longitudinal direction of the busbar, in three different transverse positions, in order to simulate different machining conditions of parts with different lengths and diameters. With the data from the measurements, it is necessary to eliminate the misalignment of the artifact with ground faces to obtain the values of the positioning error in the transverse direction of the longitudinal slide guides. Once this error is known, the quality tools are applied and, with the compensations proposed from their results, we identify the best results for each application. With the study done, it was identified that the method that presented the best compensation results was from the data obtained through the Histogram. Moreover, it was determined the importance of the quality tools for this work, since through them it was possible to standardize and organize the assembly flow of the measuring equipment to avoid variations, it was possible to identify the incidence of errors within certain intervals and, from this, to know the longitudinal measurements with the largest transverse errors and propose compensations based on the values found. Finally, it was also identified the external factors that may have influenced data collection.
Conventional machining processes are one of the main methods for manufacturing parts in many sectors of industry. However, like any process, there are variations in the manufacturing process from various sources. Among them, geometric errors can represent between 40% and 70% of all errors in a machine tool. Thus, it is necessary to control this type of error so that the tolerances established for the manufacture of a part are not exceeded. Given the above, this work aims to investigate the geometric error of positioning in the transverse direction along the guides of the longitudinal carriage of the machine tool studied by obtaining quantitative data in order to measure the deviation and thus use the quality tools 5S, Flowchart, Check Sheet, Histogram, Pareto Analysis and Ishikawa Diagram to standardize, identify influencing factors and observe the distribution of errors and thus identify the regions with the largest errors and propose methods of compensation for the error found. For this, it was used as study object a mechanical horizontal lathe and, as equipments to obtain the data, a measuring column, a inductive probe, one magnetic support with articulated hydraulic arms and a 1045 steel artifact with black oxidation and rectified measuring faces. With this equipment, measurements were taken in the longitudinal direction of the busbar, in three different transverse positions, in order to simulate different machining conditions of parts with different lengths and diameters. With the data from the measurements, it is necessary to eliminate the misalignment of the artifact with ground faces to obtain the values of the positioning error in the transverse direction of the longitudinal slide guides. Once this error is known, the quality tools are applied and, with the compensations proposed from their results, we identify the best results for each application. With the study done, it was identified that the method that presented the best compensation results was from the data obtained through the Histogram. Moreover, it was determined the importance of the quality tools for this work, since through them it was possible to standardize and organize the assembly flow of the measuring equipment to avoid variations, it was possible to identify the incidence of errors within certain intervals and, from this, to know the longitudinal measurements with the largest transverse errors and propose compensations based on the values found. Finally, it was also identified the external factors that may have influenced data collection.
Descrição
Palavras-chave
Erros geométricos, Torno horizontal, Ferramentas da qualidade, Calibração indireta