MACHINE MODELING AND SIMULATIONS, Machine Modelling and Simulations 2022

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GPS product specification as a tool for threaded holes positioning
Pavol Timko

Last modified: 09. 01. 2023

Abstract


Threads and threaded joints are currently the most preferred disassembly method of joining parts. After correctly selected technologies of their production, care must also be taken to ensure their quality. In addition to ensuring the required quality of construction of the threaded holes themselves, it is necessary to observe their specified geometric deviations of the position, which can be verified by direct and indirect methods. An integral part of these methods is the implementation of various CMMs, which have lately made tremendous progress in development and at the same time have advanced tools of geometric specification. The presented article deals with the implementation of a new language of geometric product specification (GPS) when verifying the geometric deviation of the position of threaded holes. This is a wide-ranging issue, where individual starting points will be discussed in the experimental part with regard to the accuracy of the determination of the measurement result. The emphasis in the field of practical measurement will be mainly on the use of touch methods, to extract the thread profile and to implement selected approximation models that will guarantee appropriate measurement efficiency, accuracy and repeatability. When extracting the surface of the threaded hole, we will assume that all the structural elements of the verified test samples (steel  90MnCrV8) are formed by basic geometric formations, which we can clearly describe by at least the specified number of points scanned. The conclusions of the presented article will be a recommendation regarding the application of the new ISO GPS language. The acquired findings can be applied in a wide area of engineering, such as automotive or aerospace industry.