HOWA MACHINERY H3EF, Инструкция по эксплуатации, Страница: 48 / 52

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5. Troubleshooting
When there are any troubles with the operation of the chuck, the following causes are likely. Please check
these before contacting us for service.
Trouble Possible cause Recommended remedy
Damaged parts on chuck.
Disassemble and repair.
Seizure of sliding contact part. Disassemble and repair with oilstone
or replace.
Chuck does not operate
Rotating cylinder inoperative. Check the piping line. If no problem
is detected, disassemble and clean
the cylinder.
Chips heavily accumulated inside.
Disassemble and clean. Insufficient draw bar stroke.
Loosened joint between rotating
cylinder and connecting rod. Remove the rotating cylinder and
retighten.
Insufficient top jaws stroke. Adjust so that top jaws come near
the center of the stroke when they
grip the work piece.
Insufficient pressure.
Increase pressure to the set level.
Top jaws do not match the work
piece diameter. Correct top jaws forming in right
way.
Excessive cutting force. Calculate the cutting force to see if it
matches the specification of chuck.
Insufficient lubrication at draw bar
and sliding parts. Supply grease from grease nipples
and open/close the top jaws a few
times while no work piece is gripped.
Work piece slips.
Excessive speed of revolutions Reduce the speed till the necessary
gripping force is assured.
Chuck runs out. Check peripheral and end face
run-out and retighten bolts.
Stopper end face runs out.
Correct the run-out stopper end
face.
Dust has entered the draw bar or
installation end surface of top jaws. Remove top jaws, clean installation
end thoroughly to remove dust.
Jaws fastening bolts are not
tightened securely. Fasten bolts sufficiently (but not too
much).
Jaws are not formed properly. Confirm if the forming plug or the
forming ring is in parallel with
chuck's end face and if the forming
plug or the forming ring is not
deformed by gripping force. Also
check forming pressure and jaws
surface roughness.
Jaws are deformed or jaws
fastening bolts are extended due
to excessive jaws height. Lower the height of jaws as much as
possible. Excessive jaw height may
reduce the service life of the chuck.
Deformation is caused at specific
portion of jaws because jaws hold
a very heavy work piece only.
Try to grip the work piece at around
the centerline to avoid eccentric
distribution of load to any specific
jaws.
Poor accuracy.
Work piece is deformed due to
excessive gripping force.
Reduce the gripping force to a
reasonable amount to assure proper
machining.