ОСОБЕННОСТИ ПОСТРОЕНИЯ И ПРИМЕНЕНИЯ ЛОГИЧЕСКИХ МЕТОДОВ ПОИСКА ПРИЧИН ОТКАЗОВ ПОРШНЕВЫХ ДВИГАТЕЛЕЙ ВНУТРЕННЕГО СГОРАНИЯ В ЭКСПЛУАТАЦИИ

Abstract

Despite the successes in research and development of designs of modern internal combustion engines for various purpose vehicles, including aircraft, to date, no reliable methods have been created to determine the causes of their failures. The application of well-known methods in practice, including the diagnosis of engine technical condition, not only requires a lot of labor and highly qualified personnel but in many cases, it is practically ineffective. This is especially true for severe operational damage arising from the destruction of the parts and accompanied by disturbing the synchronization of their reciprocating and rotational motion. On the other hand, the performed research shows that the causes of ICE failures can also be determined by logical-probabilistic methods, including based on the fault tree analysis, drawing on the available experience of studying various engine faults. However, it is not possible to use the well-known models and methods built based on the failure tree analysis in problems of finding the causes of engine failure. The reason is since such methods have been developed for the tasks of calculating the reliability characteristics of developed engines, rather than finding the causes of their failure in operation. The solution to this problem was found in several stages. Initially, by structuring the symptoms, a fault tree was compiled that logically describes the cause-effect relationships between the failure event and the initial damage that caused it. This is done separately for each of the types of failures selected for analysis and associated with severe damage to the studying engine type. Further, for a finite number of selected types of failures, a modified (inverted) fault tree was developed. It allows you to perform a simple logical analysis in the opposite direction to the generally accepted direction - from the system failure event to the basic events initiating the failure. After that, a modified engine fault tree common to the considered types of failures was compiled. As a result of using the proposed methodology in practice, it became possible to determine the causes of engine failure with sufficient reliability with minimal time.