FUSION FAILURE DETECTION METHOD OF ELECTRIC FUSION COUPLER AND FUSION CONTROL DEVICE

摘要

PROBLEM TO BE SOLVED: To control fusion by detecting fusion failure of an electric fusion coupler due to existence of moisture on a connecting part. SOLUTION: A microphone 20 collects sound generated at the time of fusion in the neighbourhood of an EF coupler 11. A filter 23 passes a frequency band where moisture evaporating sound can exist out of the sound collected by the microphone 20 to an evaporating sound detection part 24. The evaporating sound detection part 24 outputs a trigger pulse in the case when a level of signal sound passing a filter 23 is higher than a trigger threshold value previously set. A counter 25 outputs a signal to express that evaporating sound is collected by the microphone 20 to a control part 22 when the trigger pulse is counted by the specified number of times. The control part 22 stops electric power an electric source 19 supplies to the EF coupler 11 in accordance with the signal transmitted by the counter 25, stops fusion and makes it display on an error display part 26 that moisture exists on a fusion surface.