Hitachi Construction Machinery launched two new rigid dump truck models designed for use in large-scale mining operations anywhere in the world on December 15 – the 180 t payload class EH3500AC-3 (nominal payload with standard equipment of 181 t, target gross machine operating weight of 322,000 kg), and the 220 t payload class EH4000AC-3 (nominal payload with standard equipment of 221 t, target gross machine operating weight of 384,000 kg). Key large class Hitachi truck users around the world include the Cerrejon coal mine in Colombia; the Kaltim Prima coal mine in Indonesia; and many others including trolley assist fleets at First Quantum Kansanshi, Barrick Lumwana, Exxaro Grootegeluk and Eldorado Gold’s Kişladag.
The two new rigid dump truck models are equipped with the new AC-3 drive system that was developed using Hitachi Group technologies that were already employed in conventional truck models. “This time around we improved the AC drive system with various sensors that provide information on drive conditions. The result is the Hitachi Drive Control System which reduces tire slippage on acceleration and tire lock-up during braking, and prevents chassis oscillation in a front-rear direction and tyre skid while steering.”
In addition, to satisfy the request of customers worldwide, Hitachi is giving them the choice between engines from two different companies – Cummins or MTU. This option will also be made available for the EH5000AC-3 rigid dump truck, which was launched back in February 2013. The release of these two rigid dump truck models completes the lineup for the EH AC-3 series of dump trucks equipped with an AC drive system. Hitachi states: “Along with our ultra-large hydraulic excavators, for which we boast a high market share, we plan to supply these rigid dump truck models to contribute to the improvement of productivity at mines around the world.”
The Hitachi Construction Machinery Group states it “is at present embarking on the fortification of the mining business, which is a key policy in the mid-term management plan, GROW TOGETHER 2016. In addition to further fortifying our develop, sales, and support system for high value-added products, including an autonomous driving dump truck, and carrying out development of emerging markets, we are also making optimal recommendations for mining operations and machine management, mainly using mine management systems developed by Wenco International Mining Systems Ltd. Going forward we plan to continue strengthening the mining business by working with Hitachi Group companies, including Hitachi Ltd whose strength is in information and communication, and infrastructure technologies, and also aim to provide “Reliable Solutions” to our customers worldwide.”
In detail, Hitachi coupled the AC drive system, which has a high load-responsive IGBT inverter, with drive control software that was jointly developed with other Hitachi Group companies, to achieve a system “that excels in controlling travel motor speed and torque.” Whether taking off from a standstill, ascending grades, or performing steering manoeuvres, 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 vehicle motion, this is the first time in this class of machinery that they employed the Hitachi Drive Control System which “aims to achieve higher drive control performance by reducing tyre slippage on acceleration and tyre lock-up during braking, and preventing chassis oscillation in a front-rear direction and tyre skid while steering.” Consequently, the company says it realised strong and steady travel performance that ensures more stable jobsite haul-cycle times which contributes to higher productivity. These two models also boast powerful electric brakes that are activated during downhill driving. Since these dump trucks do not require the use of mechanical brakes during normal driving, not only is deceleration smoother but maintenance for the mechanical brakes is required less frequently.
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 travelling 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 safety. Thanks to a powerful electric brake, the dump trucks can be normally operated using two pedals, one for acceleration and one for the brakes. Easier operability alleviates operator fatigue. The levers and switches for operating the body are in the centre console, making it possible operate the body with one hand.
