Maintenance And Inspection - Hitachi Koki G13YC Instrucciones De Manejo

PRACTICAL GRINDER APPLICATION
1. Grinding Pressure
Do not apply the depressed center wheel strongly
to the grinding surface. The grinder makes use of
electronic cricuit, so during application of load rotates
at high speed, so ample grinding effect can be
obtained by applying light pressure. If a strong
grinding pressure or other abnormal load is applied,
the overload protection circuit will operate and make
the grinder stop rotating, so please stop applying
load immediately. Following this, switching the
power OFF and then ON again, will cause the rotation
to increase to the regular speed.
2. Grinding angle
Do not apply the entire surface of the depressed
center wheel to the material to be ground. As
shown in Fig. 3, the machine should be held at an
angle of 15° – 30° so that the external edge of the
depressed center wheel contacts the material at an
optimum angle.
3. To prevent a new depressed center wheel from
digging into the workpiece, initial grinding should
be performed by drawing the grinder across the
workpiece toward the operator (Fig. 3 direction B).
Once the leading edge of the depressed center
wheel is properly abraded, grinding may be
conducted in either direction.
4. Switch operation
[When the switch has locking mechanism]
Switch ON: To switch on, slide the lock lever in
the direction of A and press the paddle
lever in the direction of B as shown
in Fig. 4-a.
Furthermore, slide the lock lever in the
direction of C shown in Fig. 4-b while
pressing the paddle lever to lock and
enable continuous operation.
Switch OFF: To release the locking mode, press the
paddle lever in the direction of B
shown in Fig. 4-a, and release the
paddle lever to switch off.
[When the switch has no locking mechanism]
To switch on, slide the lock lever in the direction
of A and press the paddle lever in the direction
of B as shown in Fig. 4-a. Release the paddle lever
to switch off.
NOTE: The paddle lever can not be locked.
5. Precautions immediately after finishing operation
The wheel continues to rotate after the tool is
switched off.
After switching off the machine, do not put it down
until the depressed center wheel has come to a
complete stop. Apart from avoiding serious
accidents, this precaution will reduce the amount
of dust and swarf sucked into the machine.
CAUTIONS
Check that the work piece is properly supported.
Ensure that ventilation openings are kept clear when
working in dusty conditions.
If it should become necessary to clear dust, first
disconnect the tool from the mains supply (use non-
metallic objects) and avoid damaging internal parts.
Ensure that sparks resulting from use do not create
a hazard e.g. do not hit persons, or ignite flammable
substances.
Always use eye and ear protection.
Other personal protective equipment such as dust
mask, gloves, helmet and apron should be worn
when necessary.
If in doubt, wear the protective equipment.
When the machine is not use, the power source
should be disconnected.
ASSEMBLING AND DISASSEMBLING THE
DEPRESSED CENTER WHEEL (Fig. 1)
CAUTION Be sure to switch OFF and disconnect the
attachment plug from the receptacle to avoid
a serious accident.
1. Assembling (Fig. 1)
(1) Turn the grinder upsidedown so that the spindle
is facing upward.
(2) Mount the wheel washer onto the spindle.
(3) Fit the protuberance of the depressed center wheel
or diamond wheel onto the wheel washer.
(4) Assemble the wheel nut onto the spindle.
(With G15YC, for diamond wheel assembling, use
the wheel nut with the flat side against the diamond
wheel.)
(5) Insert the push button to prevent rotation of the
spindle, and tighten the wheel nut with accessory
wrench, as shown in Fig. 1.
2. Disassembling
Follow the above procedures in reverse.
CAUTIONS
Comfirm that the depressed center wheel is mounted
firmly.
Confirm that the spindle lock mechanism is
disengaged by pushing push button two or three
times before switching the grinder on.

MAINTENANCE AND INSPECTION

1. Inspecting the depressed center wheel
Ensure that the depressed center wheel is free of
cracks and surface defects.
2. Inspecting the mounting screws
Regularly inspect all mounting screws and ensure
that they are properly tightened. Should any of the
screws be loose, retighten them immediately. Failure
to do so could result in serious hazard.
3. Inspecting the carbon brushes (Fig. 5)
The motor employs carbon brushes which are
consumable parts. Since an excessively worn carbon
brush can result in motor trouble, replace the carbon
brushes with new ones having the same carbon
brush No. shown in the figure when it becomes
worn to or near the "wear limit". In addition, always
keep carbon brushes clean and ensue that they
slide freely within the brush holders.
4. Replacing carbon brushes (Fig. 6)
〈 Disassembly 〉
(1) Loosen the D4 tapping screw retaining the tail cover
and remove the tail cover.
(2) Use the auxiliary hexagonal wrench or small
screwdriver to pull up the edge of the spring that
is holding down the carbon brush. Remove the
edge of the spring toward the outside of the brush
holder.
English
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