Análise da capabilidade para o processo de torneamento cilíndrico externo de um torno CNC: uma abordagem detalhada utilizando Controle Estatístico de Processo

Abstract

External cylindrical turning is one of several manufacturing processes used by industries to manufacture parts for general applications, such as shafts, pins, screws, among others. Given the extensive use of this process, a greater understanding of the phenomena existing in turning is necessary, in order to ensure that the machine tool is capable of producing parts within an admissible range of dimensional tolerance. This study seeks to make a contribution to the statistical analysis of the capability of a CNC lathe in the external cylindrical turning process, taking into account the capability indices of the process C_p, C_pk and the machine tool C_M. The Statistical Process Control (CEP) method was used to analyze and estimate the capability indices of a CNC lathe, in order to facilitate the application of these indices by process managers. As a result, it was found that for tolerance indices ranging from IT7 to IT9 given a “js” fit for a nominal dimension of 16 mm the process is satisfactory and capable of producing the parts within the specification limits. Although the result for IT6 considering the same fit and nominal size was not fully satisfactory, improvement points were observed to be implemented in future works in order to guarantee the referred relevance.