Interview with Designers of the Ultra-Large Excavators
The Cutting-Edge Technologies for Downtime and Maintenance Cost Reduction, Developed on the World-Class EX8000 Ultra-Large Excavator, Are Adopted to the New EX-6 Series Giant Models.
Super-giant excavators are working night and day under tough mining conditions on the globe to suit the strong demands for natural resources. The users always seek more productive machines. To respond to this demand, Hitachi launches the new EX-6 series super-giant excavators that are developed to slash life cycle costs significantly based on its advanced technologies and years of experience. This is an interview with designers of the new EX-6 series.
——What Are the Cutting-Edge Technologies Adopted to the New EX-6 Series?
General Manager, Development Center, Mining & Heavy Equipment Div. Hiroaki Ogane
The preceding debut of the three models, EX1900, EX2500 and EX3600, of the Hitachi EX-6 series are made in July 2007. They are equipped with the newly developed clean engines to conform to the US EPA Emissions Regulation Tier 2. The remaining models of this series will come later, along with the new clean engines. All the models are designed under the common design concept at our Tsuchiura Works, using lots of common components. The highlight is the cutting-edge technologies to reduce downtime and maintenance costs, which are strongly demanded at quarries and mines. Less downtime means far more production. To slash lifetime costs, the new EX-6 series comes with a highly sophisticated monitoring system that allows the operator to make fault diagnosis and troubleshooting. This means the operator can easily monitor operating status and preventive maintenance information, locate failures, and access the operation manual stored.
Senior Engineer, Development Center, Mining & Heavy Equipment Div. Atsushi Tamane
Of course, the monitoring system is provided on the conventional models, but it mainly indicates warnings. If a trouble arises, the operator has to consult with a thick manual for troubleshooting, or wait the arrival of a service personnel. On the contrary, the advanced monitoring system on the EX-6 series indicates possible failures with the help of the manual stored. This is very helpful for troubleshooting and servicing, especially self-maintenance by the owner. With the information displayed on the monitor, the user can solve failures while calling a remote service personal. This can save downtime, and increase productivity.
——The New Monitoring System Incorporates Numerous Know-How and Sensor Technologies.
Under the basic design policy cultivated from middle-class hydraulic excavators, giant hydraulic excavators have been designed and built at Hitachi since mid-1970s. At tough mining sites, the machine is likely to suffer unexpected troubles. Some latent failures reveal a few years later. We have long been devoted to self developing and manufacturing of the excavators, and gathered an abundance of information on aging failures through field servicing and repairs. Moreover, Hitachi has always monitored all the recent giant models through satellite communication in terms of operating status and failures. Also, we listened to voices and requests of the customers through periodic technical meetings. Operating data is downloaded from field machines for product support division, designers and quality assurance staff. This data greatly assists in development, design and improvements in the products.
In fact, an adequate arrangement of about 50 sensors and items to be sensed are clarified from such the cumulative data. Data analysis suggests proper replacement intervals of parts. This was already applied to the EX-5 series. In the development of the EX-6 series, our efforts are focused on determining appropriate thresholds of warnings.
——What Are Operator-Friendly Designs on the EX-6 Series?
The electric control levers are utilized on the EX-6 series (larger than the EX1900), instead of hydraulic pilot ones. They can easily be controlled by hand actions only, with a half of conventional lever control force. This design can reduce operator’s fatigue significantly. At mining sites, hydraulic excavators are destined to work for 24 hours a day, and the operators assigned to 12-hour work shift. On the EX2500 or larger models, the new 45° electro-hydraulic retractable stairs are provided standard for safe access to the cab, in place of conventional steep mechanical ladder. These features and improvements, available on the EX8000 originally built in 2003, are adopted to all the new EX-6 series giants models.
——The Integration of Advanced Technologies and Years of Experience
We are committed to daily development and design under the consistent fundamental design policy - to make better products with continuing improvements and refinements. The result is tough, productive products that are highly reputed on tough mining sites on the globe.
The Hitachi excavators are renowned to be tough with less troubles among customers. We further strive to increase the availability of substitutes in the case of failure of the machine.
The users always need quick restoration if the machine fails. Our customers strongly expect how well Hitachi is ready for prompt response. Imagine if an engine fails, and it needs replacement with a new one, for example. If a substitute engine is available within 24 hours and replacement is done within 24 hours, restoration can be made within only two days. To this end, we plan to establish a service network, including the acquisition of parts stock yards, for more customer satisfaction.
The frames are built with internal welding enough for high strength and durability.
Hydraulic piping, arranged at the front, delivers high pressure and power without oil spill. The Hitachi hydraulic excavator is called a "dry machine" on the overseas market.
——What is the Perspective of Hitachi Super-Giant Excavators?
The urgent development of a larger machine than the EX8000 is not scheduled. This machine may compete with a mechanical shovel whose working range is strictly limited by a power cable. On the contrary, a hydraulic excavator can move around at grand job site, and is far more suitable for efficient stripping of overburden while traveling. We will give added values to the present giant EX series- for instance, greater economy such as shorter cycle times, bigger bucket capacities, and less fuel consumption, maintenance and purchase costs while keeping excellent fundamental performance, as well as good matching with dump trucks. In other words, we want to build up a reputation that the dependable mining excavators are Hitachi’s.