INTERNAL COMBUSTION ENGINE DIAGNOSING METHOD Russian patent published in 2002 - IPC

FIELD: mechanical engineering; internal combustion engines. SUBSTANCE: invention can be used for checking condition of cylinder-piston group and valve timing gear of internal combustion engines. Proposed method consists in the following: first of all run-out parameters are measured using as run-out parameter time intervals corresponding to turning of crankshaft through equal and adjacent angular intervals of preset value during engine operating cycle with synchronization of beginning of measurements with top dead center of first cylinder. In processing the measurands, ratio of crankshaft angular velocity to angle of crankshaft turning within engine operating cycle is obtained basing on which ratio of angular acceleration of crankshaft in crankshaft degrees within the same limits is found after which, on section corresponding to first half of period of torque changing at expansion stroke of cylinder under checking, change of angular acceleration is presented in form of harmonic with period equal to period of torque change, phase of this harmonic is determined and compared with reference value after which conclusion is made on technical condition of engine. EFFECT: reduced labor input and improved accuracy of engine condition diagnosing. 5 dwg