METHOD OF AND DEVICE FOR CHECKING CONDITION OF INTERNAL COMBUSTION ENGINE Russian patent published in 2003 - IPC

FIELD: instrumentation engineering. SUBSTANCE: invention relates to method of condition checking of internal combustion engines by measuring acceleration of speed up and run- out and preset harmonics of speedup acceleration under operating conditions. Method is based on continuously taking measurements in process of engine operation with relation to crankshaft turning angles at multiple accelerations under no load and run-outs, measuring instantaneous values of angular velocities and crankshaft acceleration, singling out preset harmonic components of acceleration, subtraction of said harmonic components from speed up acceleration and run-out acceleration values when engine reaches preset rotation speed, determining mean values of obtained magnitudes in each cylinder at one working stroke of piston and determining irregularity of cylinder operation basing on their ratio, and engine unbalance, by amplitudes of measured preset harmonic components. Proposed device contains engine shaft speed transmitter, level selector, synchronization transmitter, angular marks readout beginning differentiating unit, angular marks readout beginning synchronization unit, cycle angular mark setters and cylinder angular mark number setters, differentiator, time internal into code converter, time storage register, units of registers of signal of calculation of mean value of shaft rotation speed per cycle, power measuring frequency setter, acceleration values storage and irregularity coefficient calculation unit, clock-pulse generator and operation preparation circuit. Additionally introduced are second differentiator and level selector, readjustable digital filter unit, harmonic number and balance level setters, mean value and maximum calculator, while acceleration values storage and irregularity coefficient calculating units are provided with additional inputs. EFFECT: reduced labor input, improved accuracy of measurement and reliability of determination of engine condition by eliminating disturbing actions of defective cylinders. 3 cl, 6 dwg