Hitachi’s latest rigid-frame truck – the electric-drive EH4000ACII – is ready to roll. It combines Hitachi’s time-honoured front trailing arm and NEOCON-ETM suspension system with the vertical integration of Hitachi’s own IGBT AC-drive technology. The result, Hitachi says, “is a smooth-steering, smooth-riding, highly dependable, and long-lasting haul truck.” “Because it uses AC drive, the EH4000ACII has lower life-cycle costs and better performance on grade uphill or downhill with superior rimpull and retarding capabilities. The brushless motors of the drive system provide lower maintenance costs while providing increased uptime. Trolley-assist options are available to improve performance on grade by increasing productivity while reducing fuel consumption during the haul cycle.”
The EH4000ACII manoeuvres easily in tight spaces and comfortably handles the haul road with steady speed on grade. Turning diameter is 30.2 m.
Hitachi is not new to the electrical drive system business, with hundreds of drive systems running in applications varying from bullet trains and large production plant automation systems to electrically powered mining shovels and backhoes. Competitive models all depend on outside suppliers for this technology. In fact, Hitachi is the only truck manufacturer in the world that provides its own IGBT control, alternator, and AC-drive wheel motors.
The newly designed air-ride seat and optional semi-active seat, combined with a three-point rubber iso-mount on the cab, deliver a comfortable ride. A new Hitachi-made controller monitors truck systems and replaces multiple outsourced controllers. A simple flat-panel dashboard consists of a 264 mm LCD monitor that eliminates all independently placed gauges and lights. The philosophy behind the monitor in the trucks is the same as the Hitachi EX-6 Series Mining Excavators – it allows for quick troubleshooting on the machine to reduce costs and downtime.
Auto Cruise Control keeps vehicle speed constant within the set range by limiting the minimum vehicle speed. Auto Retarding Control keeps vehicle downhill speed constant within the set range by limiting the maximum vehicle speed.
AC-retarding slows the truck to near-zero ground speed, greatly reducing brake wear. To come to a complete stop, the service-brake blending feature automatically kicks in to combine the braking action of the service brakes with the dynamic retardation of the IGBT AC-drive system. This means there is just one pedal to use to achieve a smooth braking action all the way down to zero. A hill-hold brake feature is also included as a part of service-brake blending.
Other new features include:
- Planetary design with two fixed planetary gears
- Final drive with gear-oil circulation system
- Upgraded frame similar to Hitachi EH5000ACII
- Body design with sloped floor and tail chute for less spillage and smoother shedding of materials
- Hitachi load-weighing system with correction by axle/weight ratio and slope angle for greater accuracy. External display is optional.
- Easy-access front ladder, standard
- Fast-filling system is ground-level accessible for coolant, grease, hydraulic oil, and engine oil; couplers optional.
The EH4000ACII is well matched to Hitachi excavators. It takes six passes from an EX3600-6, four to five passes from an EX5500-6, and three passes from an EX8000-6.
