PURPOSE: To detect anomaly rapidly and certainly by directly detecting the variation of operation cycle when operation anomaly is generated in a fluid pressure equipment.
CONSTITUTION: In a sensor 13, the air pressure as the signal which is output from an air passage 28 on the output side is reduced by the exhaust pulsation from the air discharge port 24 of a plunger pump 11. Accordingly, an air system operating valve 38 is opened at each exhaust time by the air pressure described above, and outputs the air from a purified air source 35 to a pressure switch 39. As a result of this, the conversion circuit 14 whole outputs electric pulse at each exhaust time. This pulse is, after counted in a counter 47, compared with the standard signal from a standard signal generator 48 in a comparison circuit 49. When the pump 11 runs idle and the exhaust and the exhaust cycle is shortened, the count of the counter 47 in a same time increases, exceeding the standard signal. Thus, signal is outputted to an output circuit 52 from the comparison circuit 49, and relay 51 is operated, and an alarm 50 is operated.
MATSUMOTO TSUKASA
YOSHIZU AKITO
ISHIWA MARUICHI
NIPPON PII SHII ESU KK
| JP52108601B |