English
10
Fig. 18
MAINTENANCE AND INSPECTION
1. Inspecting the driver bit
Using a broken bit or one with a worn out tip is
dangerous because the bit can slip. Replace it.
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 may 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. 14)
The motor employs carbon brushes which are
consumable parts. Since and excessively worn carbon
brush can result in motor trouble, replace the carbon
brush with new ones when it becomes worn to or
near the “wear limit”. In addition, always keep carbon
brushes clean and ensure that they slide freely within
the brush holders.
NOTE:
When replacing the carbon brush with a new one, be
sure to use the Hitachi Carbon Brush Code No. 999054.
5. Replacing carbon brushes
Take out the carbon brush by first removing the
brush cap and then hooking the protrusion of the
carbon brush with a slotted head screw driver, etc.,
as shown in
Fig. 16
.
When installing the carbon brush, choose the direction
so that the nail of the carbon brush agrees with the
contact portion outside the brush tube. Then push it
in with a finger as illustrated in
Fig. 17
. Lastly, install
the brush cap.
CAUTION:
Be absolutely sure to insert the nail of the carbon
brush into the contact portion outside the brush tube.
(You can insert whichever one of the two nails
provided.)
Caution must be exercised since any error in this
operation can result in the deformed nail of the carbon
brush and may cause motor trouble at an early stage.
6. Cleaning of the outside
When the impact driver is stained, wipe with a soft
dry cloth or a cloth moistened with soapy water. Do
not use chloric solvents, gasoline or paint thinner, as
they melt plastics.
7. Storage
Store the impact driver in a place in which the
temperature is less than 40°C, and out of reach of
children.
Nut
Fig. 19
*The following bolt is used.
Ordinary bolt: Strength grade 4.8
High tensile bolt: Strength grade 12.9
Bolt
Steel plate thickness t
Explanation of strength grade:
4 — Yield point of bolt: 32 kgf/mm
2
8 — Pulling strength of bolt: 40 kgf/mm
2
(
)
Tightening torque
Tightening torque
Tightening time: sec.
(Steel plate thickness
t = 10 mm)
Tightening time: sec.
(Steel plate thickness
t = 25 mm)
0
1
2
3
kgf•cm
1600
1400
1200
1000
800
600
400
200
0
N•m
160
140
120
100
80
60
40
20
0
kgf•cm
1600
1400
1200
1000
800
600
400
200
0
N•m
160
140
120
100
80
60
40
20
0
0
1
2
3
Ordinary bolt
Ordinary bolt
High tension
bolt
M10
×
30
M12
×
45
Tightening torque
Tightening time: sec.
(Steel plate thickness
t = 25 mm)
1600
1400
1200
1000
800
600
400
200
0
0
1
2
3
160
140
120
100
80
60
40
20
0
N•m
kgf•cm
Ordinary bolt
M14
×
50
High tension
bolt
High tension
bolt
