DETECTING DEVICE FOR OPERATION OF SOLENOID VALVE

• Main Author: OKADA YASUMASA
• Format: Patent
• Language: English
• Published: 08.06.1988
• Subjects: ACTUATING-FLOATS; BLASTING; COCKS; DEVICES FOR VENTING OR AERATING; ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVEFUNCTIONING OF MACHINES OR INSTALLATIONS; HEATING; LIGHTING; MECHANICAL ENGINEERING; NUCLEAR ENGINEERING; NUCLEAR PHYSICS; NUCLEAR REACTORS; PHYSICS; TAPS; THERMAL INSULATION IN GENERAL; VALVES; WEAPONS

PURPOSE:To make it possible to detect a failure during either turning on or turn-off, by utilizing such a phenomenon that the inductance of a solenoid varies upon failure of a solenoid valve so that variations in oscillation period and current value are detected. CONSTITUTION:Capacitors 53 are connected in parallel to solenoid coils 62 in solenoid valve 5, 6. When a switch 52 is turned on to energize SSR51 to feed current to the solenoid valves 5, 6 and the capacitors 53, and then the switch 52 is turned off, damped oscillation is produced between the capacitors 53 and the solenoid coils 62. The current running through the solenoid coils 62 is detected by detecting circuits 55, and thus detected current is reformed into a rectangular wave by zero-potential cross comparators 57, and is delivered to AND circuits 59. Therefore, time signals for oscillation by a certain cycle number is delivered to digital comparators 60 which compare the time signals with a signal during normal operation so as to detect a failure during turn-off. A failure during turn-off is detected by turn-on abnormality discriminating circuits 60 which compare the outputs of the detection circuits 55 with a current value during normal operation.