
11.LASER OPTICAL SYSTEM B-70255EN/01
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11.1.2 Cleaning and Replacing the Rear Mirror
To clean the rear mirror, follow the procedure given below. Since it is
necessary to touch optical parts and vacuum parts while cleaning the
rear mirror, wear clean gloves or finger cots. Do not touch these parts
directly with your bare hands.
Before starting cleaning, wipe away any foreign matter from around
the parts to be removed. If a removed part is inadvertently soiled,
wipe it clean with ethyl alcohol.
Procedure
(1) Turn off the power to the CNC, then open the main circuit
breaker or turn off the power supply of the laser oscillator.
(2) Hold the entire beam cover and turn it counterclockwise
gradually to remove the beam cover. At this time, be careful not
to apply an excessive torque to the mirror holder of the output
mirror.
(3) When the pressure of the vacuum system of the oscillator is
lower than the atmospheric pressure, it may prove impossible to
remove the rear mirror. Confirm that the oscillator is in the purge
state and loosen the yellow and orange tube joints to allow the
internal pressure of the vacuum system to equalize with the
atmospheric pressure. If a negative pressure exists in the vacuum
system, the atmospheric pressure sensor must be adjusted. (See
Section 9.4.2.)
(4) Loosen the mirror holder mounting screw (M4 hexagon socket
head bolt), and remove the mirror holder from the alignment
unit.
CAUTION
When removing the mirror holder, be careful not to
drop the mirror from the mirror holder.
(5) Remove the rear mirror and O-ring from the mirror holder, and
place them on lens cleaning paper. To simply replace the rear
mirror at this point, go to step (12).
NOTE
When cleaning or replacing a mirror, be sure to
check the states of the O-rings of the mirror holder. If
a damaged O-ring or an O-ring that has lost elasticity
is used without replacement, gas can leak. It is
recommended to replace such O-rings as early as
possible.