Maintenance And Inspection - Hitachi Koki WH 14DM Handling Instructions Manual

English
kgf•cm N•m M8×30
1600
160
1400 140
1200 120
High tension bolt
1000 100
800 80
600 60
40
400
Ordinary bolt
20
200
0 0
0 1
Tightening time: sec
(Steel plate thickness
t = 10 mm)
Bolt
Nut

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 whthin
the brush holders.
NOTE:
When replacing the carbon brush with a new one, be
sure to use the Hitachi Carbon Brush Code No. 999054.
37
kgf•cm
1600
1400
1200
1000
800
600
400
200
0
2 3
Tightening time: sec
(Steel plate thickness
t = 10 mm)
Steel plate thickness t
N•m M10×30
160
140
High tension bolt
120
100
80
60
Ordinary bolt
40
20
0
0 1 2 3
Fig. 18
* The following bolt is used.
Ordinary bolt: Strength grade 4.8
High tensile bolt: Strength grade 12.9
(
Explanation of strength grade:
4 — Yield point of bolt: 32 kgf/mm
8 — Pulling strength of bolt: 40 kgf/mm
Fig. 19
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.
kgf•cm N•m M12×45
1600 160
High tension bolt
1400 140
1200 120
1000 100
800 80
Ordinary bolt
600 60
400 40
200
20
0 0
0 1 2
Tightening time: sec
(Steel plate thickness
t = 10 mm)
2
3
)
2