Diagnostics of the gas distribution mechanism based on the control of vibration vibrations of its elements

The operability and efficiency of the engines significantly depend on the periodic diagnostics of their technical condition. Currently, vibration-based damage detection (measurement of vibration characteristics of structures and mechanisms) is a promising area of research activity. The features of monitoring and diagnostics of internal combustion engines using vibroacoustic analysis are considered. In the article a method has been developed for determining the main malfunctions of the gas distribution mechanism (tightness of the valve-seat coupling, thermal gap in the valve actuator, valve opening and closing phases), consisting in measuring and analyzing vibroacoustic pulses caused by the operation of individual engine elements. The maximum amplitude (peak) and the moment of occurrence of vibration pulses are used as signal parameters. A vibration pulse from the impact of the piston on the elastic tip placed in the combustion chamber is taken as the reference signal of the TDC of the piston of the cylinder under study. The speed of rotation of the crankshaft up to 600 min-1 (does not exceed the frequency of scrolling by the starter) does not lead to the appearance of dangerous stresses in any of the elements of the engine and the device. At the same time, the tip made of Bflex plastic, as the most malleable element, can be repeatedly used. To ensure a trouble-free diagnostic process, calculations were carried out using the software - Solid Works Simulation and the finite element method (FEM) built into it. To calculate the stresses, the solver finds the displacements at each node, and then calculates the deformations and the final stress. As a result of the study, the proposed diagnostic method allows to achieve an accuracy of up to 96 %.