els completes the lineup for the EH AC-3 series of haulers
equipped with an AC-drive system.
Along with the company’s ultra-large hydraulic excava-
tors, for which Hitachi boasts a high market share, Hitachi
plans to supply these rigid haul truck models to contribute
to the improvement of productivity at mines around the
1. Increased mobility and productivity
Hitachi couples the AC-drive system, which has a high
load-responsive IGBT inverter, with drive control software
that was jointly developed with other Hitachi Group com-
panies, to achieve a system that excels in controlling travel
motor speed and torque.
Whether taking off from a standstill, ascending grades
or performing steering maneuvers, the system delivers an
optimal, individual amount of power to each of the travel
motors for smooth, quick operation.
In addition to adding various sensors that detect vehi-
cle motion, this is the first time in this class of machinery
that models employ the Hitachi Drive Control System.
This aims to achieve higher drive control performance
by reducing tire slippage on acceleration and tire lock-
up during braking, and preventing chassis oscillation in a
front-rear direction and tire skid while steering.
Consequently, the trucks boast strong and steady
travel performance that ensures more stable jobsite haul-
cycle times, which contributes to higher productivity.
These two models also feature powerful electric
brakes that are activated during downhill driving.
Since these trucks do not require the use of mechani-
cal brakes during normal driving, not only is deceleration
smoother but maintenance for the mechanical brakes is
required less frequently.
2. Increased Operator Features
In the wide-berth cab, which is capable of housing two
full-size seats, a large LCD display is located at the base
of the handle. The display is in clear view and quickly
provides the operator with information and warnings on
drive operations such as traveling speed, engine turnover
and hauling performance.
In addition, the multilingual display allows users to
view information and warnings in their own language,
thereby contributing to improved serviceability and safe-
Thanks to a powerful electric brake, the haulers can be
normally operated using two pedals, one for acceleration
and one for the brakes. Easier operability alleviates opera-
Hitachi located the levers and switches for operating
the body in the center console, making it possible to oper-
ate the body with one hand.
3. Increased reliability and safety
The mainframe’s structural design, including the cab sup-
port, is improved and fortified based on operating infor-
mation Hitachi gathered on conventional models being
used around the world.
The company added a temperature sensor to the
bearing area of the alternator and drive motor, which are
the main components of the AC-drive system.
An alarm sounds when the sensor detects abnormal
heat emission and restricts driving operations to prevent
sudden damage to the machine.
Improvements were made to the nominal payload
measurement system to increase the reliability of produc-
tion volume measurements at mining sites. Measurement
errors have been reduced by reflecting changes in fuel
weight within the fuel tank into the nominal payload.
ROPS and FOPS are built into every truck cab as a
standard safety requirement to withstand the impact of
falling objects or a truck rollover.
Other standard safety features include:
• two mirrors with front and rear view cameras to
provide extensive truck perimeter visibility,
• ample width truck access stairways
• four engine stop switches located outside the cab
to allow the operator to turn off the engine in an
emergency situation during maintenance.
In addition, the wide cab features ample foot space to
improve the operating environment.
Peripheral Vision Support System
vides another view to support the operator.
4. Maintenance and serviceability
The evacuator exhaust valve for the engine suction filter
and electric grease pump are among the new features
added to further improve daily maintenance.
Other standard features for maintenance include a
trailing arm front suspension that permits strut removal
without tyre removal, a centralized auto-grease system
accessible from the ground, a battery and relay box lo-
cated in the front bumper for easy access, and a mainte-
nance deck in the rear of the cab.
Outside of North America, Hitachi is now
offering customers the option of choosing be-
tween the standard feature Cummins Inc. en-
gine and one by MTU Friedrichshafen GmbH.
New technology enhances
safety of Hitachi mining
Hitachi Construction Machinery Co., Ltd (HCM)
has obtained the licence for camera image
In the wide-berth cab, which is capable
of housing two full-size seats, a large LCD
display is located at the base of the handle.
Contractors World International Vol 6 No 4
What’s New In Plant & Equipment