76-QD7913EN-00Y00-03.doc
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8. Judgement of tightening
①
Judging that the result of tightening is in the set range after tightening.
②
If the result is in the set range, OK of tightening judgment lamp lights up.
If any defect is detected, the contents of the defect are displayed in the tigh tening result.
Detection of abnormality
Abnormal tightening is as described below.
・
Galling
: Foreign matter enters between female and male screws and tightening torque
increases without generation of clamp force.
・
Seizure
: It occurs when part of thread of male or female screw is stripped.
Tightening torque increases since tightening is proceeded while threads are
being stripped.
・
Slantwise screwing: This is a phenomenon that a bolt is slantwise screwed into female screw,
because of position gap between the axis of bolt and that of female screw or of
angle shift. Tightening torque increases without generation of clamp force.
・
Over-tightening: Bolt is tightened with excessive torque.
・
Under-tightening: Bolt is tightened with insufficient torque.
・
Lack of quantity of tightened bolt: Lack in quantity of tightened bolt.
①
Torque error (indication of judgment of tightening)
・
OVER
: Over-tightened.
・
UNDER
: Under-tightened.
②
Pulse number error (indication of judgment of tightening)
・
SLOW ER. : Number of pulse required for tightening exceeds the SLOW ER. number.
SLOW ER. No.
TORQUE
MAX TORQUE
CUT TORQUE
MIN TORQUE
START TORQUE