Construction World June 2016

EQUIPMENT

“There are currently 360 20T Doosan DX excavators in operation in the local market and we expect the improved DX225LCA series to further consolidate Doosan’s position as a leading supplier in this size class of equipment,” says Newest generation HYDRAULIC excavators Doosan’s newest generation hydraulic excavators – the heavy duty DX225LCA series – has been designed for greater operator comfort, improved fuel efficiency, enhanced productivity and minimal maintenance requirements. >

Engines Doosan’s high strength excavators have a new 6-cylinder water cooled engine that is optimised and electronically controlled to boost produc- tion, maximise fuel efficiency and ensure harmful emissions remain well below the values required for Tier II engines. The 21,5 T operating weight of these excavators is enhanced by new specifications that include a 0,92 m³ bucket capacity, a digging depth of 5 755 mm, a digging reach of 8 950 mm and a digging height of 9 750 mm. The engine rated power is 110 kW (148 HP) at 1 900 rpm. Maximum engine torque is 61,5 kg/m/1 400 rpm. For optimum control, the e-POS system (Electronic Power Opti- mising System) provides a perfect synchronised communication link between the engine’s electronic control unit and the hydraulic system. A controller area network system facilitates a constant flow of infor- mation between the engine and hydraulic system, ensuring power is delivered exactly as it is needed. This hydraulic system enables independent or combined opera- tions. Two travel speeds offer either increased torque or high speed tracking and an auto deceleration system and cross sensing pump ensure fuel savings. Two variable displacement axial piston pumps have maximum flow capacity of 2 x 206,5 ℓ/min to reduce cycle times, while a high capacity gear pump, with a maximum flow of 2 x 28,5 ℓ/min, improves pilot line efficiency. The choice between standard and power operating modes opti- mises performance in all conditions, including harsh environments. Standard mode uses 85% engine power for general work and power mode uses 100% engine power for heavy tasks. Operations The conveniently situated multi-function colour LCD monitor panel has standard features for simple control and efficient operation. These controls include mode selection, precise flow rate regulation, auto deceleration and display selection. Maintenance and oil change intervals can be displayed, a self-diagnosis function allows technical problems to be quickly resolved and an operational memory provides a graphic display of the machine’s status. Levelling operations, movement of lifted loads and tricky manoeu- vres are all controlled easily and precisely with control levers. Buttons integrated on the levers are used to operate additional equipment, like grabs, crushers and grippers. Ergonomics Ultimately an excavator’s work rate depends on the performance of the operator. For this reason, Doosan’s new DX225LCA machines have been designed with the latest ergonomics which enhance efficient operation, improve safety and offer greater comfort. New features include a spacious, all weather sound-suppressed cab with a clear all round view, effective air conditioning and an adjustable seat, with an optional air suspension system to reduce vibrations. For improved safety, there are large handrails and a wide step with anti- slip plates, right and left rear view mirrors, a travel alarm and safety glass. This series has been designed for easy maintenance and reduced downtime. A PC monitoring function enables connection to the e-POS system. Various parameters can be checked during maintenance, including pump pressure, engine rotation and engine speed. This infor- mation can be stored and printed for analysis. Doosan earthmoving equipment – which encompasses track, wheel and mini excavators, articulated dump trucks (ADT’s), as well as wheel loaders and various attachments – has been designed to cope efficiently and safely in Africa’s harsh operating conditions. Doosan’s newest generation hydraulic DX225LCA excavators are fitted with special features to ensure optimum efficiency and extended service life in harsh local operating conditions.

Chris Whitehead, national sales manager, DISA Equipment, trading as Doosan, part of the Capital Equipment Group (CEG) of Invicta Holdings Limited. “These robust excavators, which are now available in Southern Africa, are fitted with special features to ensure optimum efficiency and extended service life in harsh local operating conditions. “Design features for the African market include a Tier II mechanical engine for reduced operating costs, a heavy duty boom and arm, as well as standard hydraulic piping for hammer applications. These machines also have an improved H Class bucket and are supported by Doosan with a 2 year/ 4 000 hour warranty. “This series features a range of new technologies that deliver effec- tive control over the machine’s power and also simplify maintenance procedures. As a result, efficiency and machine durability are increased, productivity is improved and operational costs are lowered.” Finite Element Analysis High performance materials, combined with advanced computer assisted design techniques, including Finite Element Analysis (FEA) are used by Doosan to create robust structures and all materials and components are tested under the most extreme conditions. FEA has been used to calculate the best distribution loads throughout the boom structure. The new strengthened boom of this series has increased material thickness which limits element fatigue, thus increasing reliability and extending component life. A polymer shim added to the bucket pivot maintains precise control over the equipment. Cast elements are used in the arm assembly and reinforce- ment is added around the bosses for additional strength and extended service life. All welded structures have been designed to limit stresses. The lateral chassis is welded and rigidly attached to the undercarriage. Tracks are composed of sealed, self-lubricating links, which are isolated from external contamination for dependability in all conditions. Tracks are locked by mechanically bolted pins. The hydraulic track adjuster has a shock absorbing tension mechanism.

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CONSTRUCTION WORLD JUNE 2016