1

Doosan expands iT4 compliant equipment lineup, adds product enhancements

Spring 2012

This spring, Doosan is expanding its heavy equipment lineup with the introduction of new crawler excavators and wheel loaders. These new Doosan machines have an interim Tier 4 (iT4) diesel engine. Additionally, the new Doosan excavators and wheel loaders feature many product enhancements aimed at improving power, performance, reliability and comfort.

Two new crawler excavators are the first Doosan models in North America with iT4 compliant diesel engines. They are the 30-metric-ton DX300LC and 35-metric-ton DX350LC. Three new Doosan wheel loaders with iT4 compliant diesel engines will also be available in North America this spring. They include the DL350, DL420 and DL450 wheel loaders.

New Doosan excavators offer more horsepower and torque

The new iT4 compliant Doosan DX300LC and DX350LC are among a group of crawler excavators that are popular in building and infrastructure projects such as highway, street development and paving projects, as well as pipeline development.

More power and torque

New iT4 compliant diesel engines in the DX300LC and DX350LC excavators offer more horsepower and torque, variable geometry turbochargers (VGT), upgraded cooling and powerful hydraulic systems. Increased power from the excavator's arm and bucket forces allow you to move more dirt. The new DX350LC has a 281-horsepower, 6-cylinder Doosan DL08K water-cooled diesel engine, resulting in an increase in engine horsepower from 275 to 281. It also has more torque, 940 lb. ft. at 1,300 RPM.

New Doosan iT4 compliant diesel engines in the DX300LC and DX350LC have a VGT to increase boost pressure at lower engine RPM. An electronic control unit (ECU) controls the VGT. The VGT varies the amount of boost supplied to the engine to optimize combustion over the entire engine RPM range. The engine can generate a greater amount of torque in a wide band in the RPM range, increasing engine performance at a lower engine RPM.

Exclusive to the DX350LC, a new closed-center main control valve with electro-hydraulic pump control allows the ECU to precisely optimize engine power with hydraulic performance. This leads to approximately 20 percent increase in efficiency of the pressure-controlled, closed-center main control valve, which leads to improved fuel economy and improved controllability when lifting

In addition to the VGT, a high-pressure common-rail (HPCR) fuel system increases the efficiency of fuel delivery by increasing pressure to 26,100 psi. Increased fuel pressure allows the injector to inject a fine mist into the engine, which provides a more efficient combustion as required by the lower combustion chamber temperature.

Performance improvements

In conjunction with new iT4 compliant engines, Doosan excavators now include a number of performance improvements aimed at increasing operator productivity. An increase in engine horsepower and torque improve excavator workgroup functions, with more consistent flow from the main hydraulic pump. Best-in-class hydraulics deliver superior bucket and arm breakout forces. Additionally, swing torque in new Doosan excavators increased by approximately 8 to 11 percent. Operators can swing uphill more easily and realize improved backfilling of trenches.

Digging force and lifting capacity have increased as well. Digging force increased by about 5 percent to help operators easily power through harsh digging conditions. An increase in lifting capacity by about 2 percent allows operators to lift more material with each cycle, and to place objects such as pipes easier as well. Boom-up speed improved by about 6 percent, resulting in improved cycle times and improved truck loading time to move more material per hour.

To further assist with lifting applications, new Doosan excavators have a lifting work mode. It provides increased pump torque, low engine RPMs and automatic power boost for lifting heavy objects such as pipe or concrete barriers.

Doosan excavator operators can choose from four power modes to best match their application. Choose from Power+, Power, Standard and Economy modes to manage fuel consumption and power needed to dig, lift or load material. Simply choose the appropriate mode to match the working conditions.

New Doosan excavators have 10 to 15 percent more cooling capacity from a new cooling system. A variable-speed hydraulic cooling fan allows the oil cooling system to be controlled independently from engine coolant, improving fuel efficiency and providing a quieter operator environment. The cooling system runs at its optimum temperature to increase efficiency and extend component life.

Unmatched operator comfort

Changes to Doosan excavator cabs include additional space for enhanced operator comfort. The overall excavator cab size has increased by about 6 percent, providing more headroom. Getting in and out of excavators is easier with a 180-degree swinging door and a wider entry/exit area.

To help minimize operator fatigue and improve productivity, Doosan excavators come standard with air conditioning and heat, with automotive-style vents and controls that help distribute the air evenly in the cab. A CD player with MP3 compatibility, radio and antenna are standard. Additional cab improvements include a viscous cab-mount, which includes a coil spring to reduce vibration by 20 percent, and a new standard air suspension seat. The joystick control angle is now set at 19 degrees to provide a more ergonomic profile and more clearance for the operator's legs.

A new 7-inch LCD monitor displays important machine information with 15 different machine function warnings, and it switches to night view for easy viewing. A rearview camera button provides the operator with an additional means to view the machine surroundings, allowing for increased productivity.

Quick look: DX300LC and DX350LC specs

DX300LC

Horsepower: 213 hp

Operating weight: 69187 lb

Maximum reach at grade: 34' 7"

Maximum dump height: 23' 11"

Maximum dig depth: 24'

Arm breakout force: 30644 lbf

Bucket breakout force: 44092 lbf

Swing speed: 9.9 rpm

DX350LC

Horsepower: 281 hp

Operating weight: 77603 lb

Maximum reach at grade: 36'

Maximum dump height: 23' 6"

Maximum dig depth: 24' 9"

Arm breakout force: 41667 lbf

Bucket breakout force: 57000 lbf

Swing speed: 9.3 rpm

New Doosan wheel loaders feature improved power, productivity and comfort

The new models have improved power and productivity, as well as improved operator comfort, and are designed for large material-handling applications.

The new Doosan wheel loader lineup includes the DL350, DL420 and DL450, the first Doosan models with iT4 compliant engines to be available in North America. Built for rugged applications, the Doosan wheel loaders are popular for large material-handling applications, and especially with operators who work in quarries, mines, demolition and sand and gravel operations. Additionally, many municipalities depend on Doosan wheel loaders for material-handling tasks and snow removal.

More power

In conjunction with new iT4 compliant diesel engines, new Doosan wheel loaders have more engine horsepower, increased optional driving power and steering capabilities. Specific to the DL450, one of the largest wheel loaders in the Doosan lineup, the horsepower has been increased from 301 to 354 hp, and the DL450 has increased torque (1,120 lbf at 1,400 RPM). It is powered by a 6-cylinder, liquid-cooled diesel engine.

To comply with EPA air quality requirements, the three new Doosan wheel loaders use Selective Catalyst Reduction (SCR) with Diesel Exhaust Fluid (DEF) to meet EPA emission requirements. SCR-configured engines are optimized to reduce particulate matter (PM) in the combustion chamber, reducing Nitrogen Oxide (NO_x) by using DEF, which is a solution of water and ammonia. The combination of exhaust with DEF causes it to react with a catalyst. This reaction turns harmful NO_x into harmless nitrogen and water vapor. SCR systems offer increased fuel efficiency - as much as 16 percent with the DL450 - due to engine optimization that results in a more complete fuel burn.

In the new DL450 wheel loader, a high-pressure common-rail (HPCR) design with direct fuel injection, and an electronic control increase fuel delivery by increasing the pressure up to 24,000 psi. The increased fuel pressure allows the injector to inject a finer mist into the diesel engine, which results in a more efficient combustion. Better combustion produces more torque, less noise, lower operating costs, improves fuel economy and creates cleaner exhaust.

Performance enhancements

Optional for the three new Doosan wheel loaders is a hydraulic locking differential, replacing the standard limited slip differential. The hydraulic locking differential provides increased driving power when one wheel spins or loses traction. With the hydraulic locking differential, the left and right wheels are locked together using hydraulic pressure to allow them to rotate at the same speed and receive equal torque, providing the machine with more traction and less slippage.

Also available as an option is a torque converter lockup. This enables the machine to climb grades easier and faster, increasing productivity by as much as 20 percent in certain stockpiling applications.

New Doosan wheel loader cabs feature improved visibility to the work area in front of the machine. Another additional option is an electronic main control valve. This allows the operator to set the lift arm positional limits from inside the cab, providing improved control of the lift arm and bucket positions, and is useful when setting return to dig positions for the lift arm and bucket. It reduces cycle times in digging and loading applications.

Improved operator comfort

New Doosan wheel loader cab improvements provide a more comfortable operating station. A new door makes getting in and out of Doosan wheel loaders easier, as well as cleaning the inside of the cab. An air suspension seat provides a comfortable ride, and each machine comes standard with a radio. A new automatic heating, ventilation and air conditioning system allows the operator to set and maintain a constant cab temperature, while a 31 percent increase in airflow has significantly improved the efficiency of the heater and air conditioner.

Quick look: DL420 and DL450 specs

DL420

Horsepower: 354 hp

Operating weight: 50900 lb

Bucket capacity: 6.5 cu. yd.

Dump height: 10' 1"

Dump reach: 4' 2"

Breakout force: 47210 lbf

DL450

Horsepower: 354 hp

Operating weight: 56329 lb

Bucket capacity: 6.3 cu. yd.

Dump height: 10' 8"

Dump reach: 4' 2"

Breakout force: 52864 lbf

Did you know?

Doosan is a global company that has been in business for 115 years, and began manufacturing equipment in 1937. Today the organization has grown to become the sixth largest construction equipment manufacturer in the world.