PURPOSE: To diagnose the abnormality of a valve at an early stage by providing an acoustic emission(AE) sensor for detecting an elastic wave to a part of a valve mechanism and extracting the characteristics of the detection signal from the AC sensor.
CONSTITUTION: The cooling medium entering the compression chamber 3 of a scroll compressor 1 from the suction port 3 thereof is compressed by scrolls 4 to be emitted from an emitting orifice 6 through a check valve 5. An AE sensor 8 for detecting an elastic wave is arranged to the case 7 of the compressor 1 in order to monitor the operation state of the check valve 5. The output of the AE sensor 8 is amplified by an amplifier 9 and processed in an AE signal characteristic extraction part 10 to be diagnosed in an abnormality judging part 11, and the judgment is displayed on a display part 12. The output signal of the abnormality judging part 1 is inputted to a compressor control part 13 and, when a signal of resonance abnormality or valve abnormality is generated, suction pressure or emission pressure is controlled to hold a normal operation state.
YONEYAMA TAKAO
SATO MINORU
NAKAZAWA TOSHIO
YANAGIBASHI MINORU
HITACHI ENG SERVICE