Sensor detects clamping force.
Specially designed to be mounted inside the bore of a bolt,
a force-sensor sends signals about the clamping force applied
to an external receiver.
When bolts are used to apply precise forces to the clamped parts
it is often difficult to establish, from the applied torque, those forces.
Variations of surface finishes, fit of bolts and mating surfaces may
absorb up to 90% of the torque in friction.
Systems to determine true clamping forces can use compression
washers, load cells, and ultrasonics, but may not be practicable or
economic to use. A new low-cost solution is the Kyowa bolt-sensor
which can be used with existing standard bolts in sizes from M6
up to M12.
A single linear strain gauge is mounted on a 2mm-diameter former.
The former is inserted into a 2mm-diameter hole drilled axially into
the bolt head, occupying a position in the shank of the bolt.
The measured strain, detected by the strain gauge, has a linear
relationship with the clamping force. The device may be used to
calibrate a torque device for a specific application.
It is also possible to measure the forces continuously during a
working cycle of the components.
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For further information please contact:
Graham & White Instruments Ltd.
Tel +44(0) 1727 859373
Fax +44(0) 1727 844272
November 2000