Maintenance And Inspection - Hitachi DH 40MR Instruction Manual

USING DRILL CHUCK, CHUCK ADAPTER
Note that this machine can be used at "rotation only" if
separately sold parts such as drill chuck and chuck adapter
are attached. Use it with the selector lever positioned at
"rotation + hammering".
CAUTION:
During operation, be sure to grip the handle and the
side handle firmly to prevent your body from swaying.
(1) Switching to "rotation + hammering"
For switching to "rotation + hammering", follow the
same procedures mentioned in [3. When drilling at
"rotation + hammering"].
(2) Attaching chuck adapter to drill chuck (Fig. 14)
(a) Attach the chuck adapter to the drill chuck.
(b) The SDS max shank of the chuck adapter is
equivalent to the drill bit. Therefore, follow the
same procedure as [How to install tool] for
attaching and detaching.
(3) Drilling
(a) Even if you apply more-than-required pressure to
the machine body, drilling can never be performed
as quickly as you expect. Applying more force or
pressure to the machine body than what is needed,
on the contrary, damages the drill tip, resulting in
the declined working efficiency and shortened life
of this machine.
(b) A drill can snap sometimes when drilling is almost
finished. It is important to relax your thrusting
pressure when drilling is nearing the end.
HOW TO HANDLE A CORE BIT
When a core bit is used, large diameter holes and blind
holes can be drilled. In this case, use optional accessories
for core bits (such as a center pin and core bit shank) for
more efficient operation.
1. Mounting
CAUTION
Prior to mounting a core bit, always disconnect the
plug from the power supply receptacle.
(1) Mount the core bit on the core bit shank. (Fig. 15)
Before that, feed oil to the screw portion of core bit
shank for easy dismounting.
(2) Mount the core bit shank on the main body in the
same manner as in mounting the drill bit and the bull
point. (Fig. 16)
(3) Insert the center pin into the guide plate until it reaches
the extremity.
(4) Fit in the guide plate by aligning its concaved portion
with the core bit tip. When the position of the concave
is shifted by turning the guide plate right or left, the
guide plate never slips off even when the drill is used
in a downward direction. (Fig. 17)
2. Drilling holes
(1) Insert the plug into a receptacle.
(2) A spring is built in the center pin. By straightly and
gently pressing it to the wall or floor surface, the
entire surface of the core bit tip attains contact to
start the hole drilling job. (Fig. 18)
(3) When the hole depth reaches approximately 5 mm,
the hole position can be determined. Then remove
the center pin and guide plate from the core bit and
continue the hole drilling job.
15
CAUTION
When removing the center pin and guide plate, always
disconnect the plug from the receptacle.
3. How to dismount the core bit
By holding the rotary hammer (with the core bit
inserted) in an upward position, drive the rotary
hammer to repeat impact operation two or three
times, whereby the screw is loosened and the rotary
hammer becomes ready for disassembly. (Fig. 19)
Remove the core bit shank from the rotary hammer,
hold the core bit with one hand, and strongly strike
the head of the SDS max shank portion of the core bit
shank with a manual hammer two or three times,
whereby the round head screw is loosened and the
rotary hammer is ready for disassembly. (Fig. 20)
HOW TO REPLACE GREASE
This machine is of full air-tight construction to protect
against dust and to prevent lubricant leakage. Therefore,
the machine can be used without lubrication for long
periods. Replace the grease as described below.
1. Grease replacement period
After purchase, replace grease after every 6 months
of usage. Ask for grease replacement at the nearest
Hitachi authorized Service center. Proceed for
replacement of grease.
2. Grease replenishment
CAUTION
Before replenishing the grease, turn the power off
and pull out the power plug.
(1) Remove the crank cover and wipe off the grease
inside. (Fig. 21)
(2) Supply 30g of Hitachi Electric Hammer Grease A
(Standard accessory, contained in tube) to the crank
case.
(3) After replenishing the grease, install the crank cover
securely.
NOTE
The Hitachi Electric Hammer Grease A is of the low
viscosity type. If necessary purchase from an Hitachi
authorized Service center.

MAINTENANCE AND INSPECTION

1. Inspecting the tool
Since use of a dull tool will degrade efficiency and
cause possible motor malfunction, sharpen or replace
the tool as soon as abrasion is noted.
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. Maintenance of the motor
The motor unit winding is the very "heart" of the
power tool. Exercise due care to ensure the winding
does not become damaged and/or wet with oil or
water.
4. Inspecting the carbon brushes (Fig. 22)
The Motor employs carbon brushes which are
consumable parts. When they become worn to or
near the "wear limit", it could result in motor trouble.
When an auto-stop carbon brush is equipped, the
motor will stop automatically. At that time, replace