| 摘要 |
<p>PURPOSE:To automatically detect the loosening of a screw by providing a sensor to detect the abutting of a washer at the position where the washer which is jointly tightened by a member and the screw is loosened and falls therefrom. CONSTITUTION:In the system where pipings 1a, 1b are connected by tightening the flanges 2a, 2b by a male screw 4 and a female screw 5, washers 8a, 8b to be used in screw setting are formed by two-split washer pieces 9a, 9b, and both washer pieces 9a, 9b are used in a mutually abutted condition. An impact sensor 11 consisting of a piezoelectric element such as the voltage ceramics is arranged on a floor 10 to the lower part of a monitoring part which is the flange connecting part. The voltage Vs generated by the impact sensor 11 when the washer pieces 9a, 9b at the position where the screw is loosened fall on the impact sensor 11 is compared with the reference voltage Vr by a comparator 12, and an alarm lamp 14 in a monitoring room is lit based on the result.</p> |
