METHOD OF AND DEVICE FOR DIAGNOSING CONDITION OF INTERNAL COMBUSTION ENGINE AND/OR TRANSMISSION OF AUTOMOBILE Russian patent published in 2001 - IPC

FIELD: transport engineering; vehicle transmissions and internal combustion engines. SUBSTANCE: proposed method of diagnosing condition of internal combustion engine and/or transmission includes measuring vibroacoustic signals from engine body, synchronization and filtration of signals and their subsequent processing to find actual parameters of vibroacoustic signals and comparing the parameters with level of reference vibroacoustic signals, thus obtaining information of condition of internal combustion engine and/or transmission of automobile by which, at cranking the engine before beginning of diagnosing procedure and at using pressure transmitter inside reference cylinder, phase delays between top dead center at working stroke in reference cylinder and synchrosignal of working stroke are determined and phase of opening and closing of timing gear valves are found. When diagnosing condition of operating internal combustion engine synchronization of vibroacoustic signals is carried out relative to top dead center at working stroke in reference cylinder. Envelope of time realization in definite frequency bands with referencing of moment of beginning of measurement to top dead center in reference cylinder and phase selection of vibroacoustic signals are used as parameter of vibroacoustic signals, thus obtaining information of technical condition of internal combustion engine and on its defects. Device designed for diagnosing condition if internal combustion engine and/or transmission of automobile includes series-connected vibration pickup with amplifier, filter, cycle transmitter, amplifier-shaper of vibroacoustic signals of cycle transmitter and indicator unit and it provided additionally with multiplexer and analog-to-digital converter with filter placed in between, and also with control and processing device. Diagnosing device is furnished also with pressure transmitter connected with multiplexer through amplifier. Amplifier-shaper of signals of cycle transmitter consists of controlled attenuator, of amplifier-shaper, peak detector, subtracter, second attenuator and comparator unit. Output of cycle transmitter and output of subtracter are connected to input of controlled attenuator whose output is connected with input of УВ. Output of УВ is connected with inputs of peak detector is connected with inputs of subtracter and second attenuator. Output of second attenuator is connected with second input of comparator unit whose output is connected with multiplexer. EFFECT: provision of diagnosing of condition of internal combustion engines and transmissions without their disassembling at localization of defects. 19 cl, 12 dwg