13
３．
Relationship between gripping force and rotation speed
３−１．Maximum static gripping force
The static gripping force is the gripping force when the chuck is at a stop.
The power chuck has a mechanism to convert input force (piston thrust force, draw pipe
drawing force) from the cylinder to gripping force. Therefore, the gripping force when the
allowable maximum input force becomes the maximum static gripping force.
However, the gripping force is different depending on the state of grease lubrication,
grease in use, height of the jaw, etc. The maximum static gripping force specified in the
specification is the value under the following conditions:
・
The Kitagawa standard soft jaw is used as the jaw.
・
The attaching bolts of the soft jaw are tightened at the specified torque.
・
The numerical values are obtained with the Kitagawa gripping force meter . The
gripping position of the gripping force meter is at a position the chuck surface.
・
CHUCK GREASE PRO is used.
・
A variable displacement pump with the discharge volume of 20 liters/min or more is
used as the hydraulic source. The pressure is set by the pressure control equipment
of the pump itself, or the pressure reduction valve equipped separately.
３−２．Allowable maximum rotation speed
In the case of outside diameter gripping, when the chuck is rotated, the gripping force
lowers due to the centrifugal force of the top jaw. The centrifugal force is different
depending on the mass of the top jaw and the barycentric position as well as the
rotation speed. The allowable maximum rotation speed specified in the specification is
the value under the following conditions:
・
The Kitagawa standard soft jaw is used.
・
Grip the gripping force meter in the center of the jaw stroke.
・
The gripping position of the gripping force meter is at a position the chuck
surface(
Theoretical value
).
