Selling Point Descriptions - Hitachi DH 40MR Technical And Service Manual

4-1. Selling Point Descriptions

4-1-1. High drilling speed with low vibration and noise level
The drilling speed is 10 % faster than that of similar products thanks to efficient striking energy transmission and
speed setting. Even so, the Model DH 40MR produces lower vibration and noise levels than those of similar
products.
Maker
Ratio of drilling speed
Full-load vibration level
Full-load noise level
No-load noise level
4-1-2. Self-drilling (Good feeling)
Thanks to the computer-simulated optimum striking characteristics, the quantity of body jumping is less than that
of the current Model DH 40MA and the working tool smoothly penetrates into the workpiece with a light pressing
force. The Model DH 40MR realizes quicker self-drilling with better impact feeling.
Impact efficiency
Maximum compressed air force (piston force)
Quantity of body jumping
4-1-3. Internal double-insulation construction with sturdy aluminum frame
The aluminum die-cast outer frame is very sturdy (same as the Models H 45MR/H 45SR). In addition, a plastic
internal S holder is adopted to realize double-insulation construction. Thus the housing has greater rigidity and
the double-insulated motor has greater durability. The Model DH 40MR is heavy-duty and the service life of the
carbon brush is greatly prolonged (1.5 times longer than the conventional one) minimizing disconnection of the
armature, deviation of the core and grease leakage.
4-1-4. Dial type, constant speed with variable speed control
The Model DH 40MR is equipped with a built-in electronic control circuit
that can adjust the number of hammering steplessly between 1320 and
2650 min -1 with the dial. Even though the load varies, the Model
DH 40MR provides better operability and stable and efficient drilling
performance because the constant speed control minimizes changes in
number of rotation and hammering.
4-1-5. Soft-touch grip for easier handling
The double-layer molded handle consists of a nylon resin base covered with a soft plastic layer to ensure a soft
touch and firm, non-slip grip of the handles.
HITACHI
Model
•
DH 40MR
% 100
116.8
dB (VL)
m/s 2
6.9
dB (A) 92.4
79.5
dB (A)
* Ratio of drilling speed: A 28-mm dia. drill bit is used.
Full-load vibration and noise levels: A 20-mm dia. drill bit is used.
HITACHI
B
DH 40MA/MB
64 85
118.0 119.8
7.9 9.8
94.6 93.7
89.4 85.0
About 10 % up
About 50 % down
About 25 % down
--- 2 ---
D
C
64
74
116.1
118.5
6.4
8.4
93.2
93.5
83.0
80.3
Speed-adjust dial