CALIBRATION CURVE AUTOMATICALLY PREPARING APPARATUS FOR BOLT AXIAL TENSION

摘要

PROBLEM TO BE SOLVED: To provide an apparatus for automatically preparing a calibration curve of a bolt axial tension necessary to be previously obtained in the case of measuring the bolt axial tension using an ultrasonic measuring method. SOLUTION: The calibrating curve automatically preparing apparatus measures a propagating time of an ultrasonic wave by transmitting and receiving the wave by an ultrasonic sensor 6 mounted at a bolt head 13 while an automatic clamping work of a hexagon head bolt 11 is executing by a nut runner 1 included in the sensor 6 at a distal end. The apparatus automatically forms the relationship between the propagating time of the wave and the bolt axial tension as the calibration curve by detecting the actual bolt axial tension by a load washer 14 engaged with a bolt clamping part. The bolt axial tension can be managed by measuring the propagating time of the wave by using the curve.