Abstract
Key words:
Discriminative analysis, wear, tribodiagnostics, qualitative and quantitative parameter, complex technical state.
ABSTRACT
In general, combustion engines wear does not depend only on the friction characteristics (rolling or sliding friction), but it is a complex physical- chemical process that occurs on sliding surfaces of the tribological units. An external, undesirable product of the friction system activity is a very wide spectrum of wear particles. With respect to diagnostics it is important that these particles contain multi-dimensional, complete information on the wear mode, and generally on actual technical condition of the technical systems. A mechanical engineering product (e.g. combustion engine) consists of many friction pairs, and their surfaces, by being in contact, simultaneously produce wear particles. The task, based on the study of number, morphology, shape, size, colour of particles, is to identify which tribologically significant processes run in the system. The decisive factor is a production of characteristic particles that corresponds to the characteristic modes of wear. Wear dynamics can unambiguously be defined and assessed by intensity of creation, material comparison, distribution, size, morphology of particles, etc. The paper deals with ways of applying mathematical methods to evaluate the result of tribodiagnostics related to vehicle combustion engines. The idea is based on a discriminative analysis that makes possible to describe one qualitative parameter (complex technical state) by means of several quantitative parameters (i.e. quantity of diagnostic parameters). The results have been verified by means of considerable statistical data of T-3-930 engines made in the Czech Republic which are used in ground vehicles.