Doosan New Generation Large Wheel Loaders
- 27 May 2012
- Product News
Doosan Infracore Construction Equipment has launched the new generation DL300-3, DL350-3, DL420-3, DL450-3 and DL550-3 large wheel loaders. Powered by Scania SCR diesel engines meeting the Stage IIIB EU emissions regulations, the new large wheel loaders combine high engine power output with new ZF transmissions and several other features to minimise fuel consumption and provide exceptional performance, ease of handling, serviceability, durability and significantly enhanced operator comfort.
With bucket capacities ranging from 3.0 to 5.5 m3, the new Doosan large wheel loaders are intended to meet a wide range of material-handling needs from loading and transporting granular material (such as sand and gravel) to industrial, mining and quarrying applications.
The DL300-3 and DL350-3 wheel loaders are driven by the 9-litre Scania DC09 SCR 5-cylinder diesel engine delivering a maximum power output of 202 kW at 1800 rpm, whilst the DL420-3, DL450-3 and DL550-3 models are powered by the larger 13-litre Scania DC13 SCR 6-cylinder diesel engine delivering 'best in class' power and engine torque, with maximum power outputs of 264, 264 and 283 kW at 1800 rpm, respectively.
Lower Fuel Consumption
Many of the features of the new generation large wheel loaders have been developed to optimize fuel efficiency. SCR technology reduces fuel consumption by about 10% compared to similar size machines with EGR technology. Resale is also better as it is easy to reset to Stage II engines for use in emerging markets.
The new large wheel loaders have three engine working modes: ECO, NORMAL and POWER, to adapt the machine to different applications, with different engine speeds and gear steps according to the working mode engaged. With the 'Power-Up' function, the operator can manually adjust to the next highest working mode by applying a full stroke of the accelerator pedal. With this function, the operator can travel in moderate NORMAL mode and switch to POWER mode when it is really needed, such as when taking material from a pile. This capability helps to reduce fuel consumption. The ECO Bar provides information about fuel consumption in relation to machine performance in real-time, allowing the operator to select the driving profile for the best fuel efficiency.
The operator can set a password for machine start. If Auto Idle is activated, engine speed goes down about 200 rpm after 10 seconds if there is no machine movement. Auto Idle is ideal for applications with long waiting times, such as truck loading. Thanks to Auto Idle, fuel consumption is reduced by up to 8%.
All new generation Doosan large wheel loaders are equipped with load-sensing controlled, variable hydraulic piston pumps, improving performance and reducing fuel consumption. With load sensing, the hydraulic pumps receive a signal from the MCV informing how much oil is needed. This helps to save on engine performance.
With the clutch cut-off system engaged, the driver is able to disconnect the transmission from the engine by operating the brake pedal, to have 100% engine performance for the hydraulic system. As a result, movements are faster, breakout force is maximized and fuel consumption is reduced.
All new generation Doosan large wheel loaders are equipped with a torque-converter-cut-off (TCCO) system which, when activated, is switched on automatically. This provides a direct mechanical connection between the engine and transmission without loss of power and torque by the torque converter. Tests show that fuel consumption is up to 10% lower with increased traction compared with conventional systems. In contrast to the drive systems on other machines, the TCCO can be engaged even in 2nd to 5th gear, not just in the highest gear. This makes the TCCO more efficient.
New ZF 5-gear transmission
The new ZF 5-gear transmission improves the transfer of power from the engine to the wheels and contributes significantly to the overall reduction in fuel consumption. The change from four to five gears provides better response and acceleration, especially on slopes. Engine speed variation is less thanks to smaller gear steps, and lower engine speed throughout the whole drive range reduces fuel consumption. Thanks to higher shift quality, noise levels are lower while driving performance and productivity have been increased. A lock-up-clutch also helps to reduce fuel consumption.
New ZF limited slip Type II differential axles provide more durability and a longer lifetime. Rolling resistance for the axles is also reduced, improving traction and decreasing fuel consumption. As an option, customers can choose ZF axles with a hydraulic differential lock. This function is engaged via the operator pedal or in automatic mode, depending on the torque resistance in 1st and 2nd gear. The advantage of the hydraulic lock system is that it has less rolling resistance compared to the limited slip system.
The radiator fan is hydraulically driven and controlled by an ECU. Changing the fan direction for cleaning the radiator can be done manually from the cab, without having to switch off the engine. Fan reverse intervals (30 minutes to 2 hours) can be set via the menu.
High Operator Comfort
A new cab design features improvements both outside – such as better visibility due to a wider front glass section and an extended wiper blade area, better protection thanks to larger mud guards, improved hand rail and step designs and a new roof cover - as well as inside – such as the new instrument panel with integrated vehicle control unit (VCU).
The control panel has been redesigned to allow the operator to choose the information they want on the display. Using the Main Menu, the operator has access to several functions and machine information. Pressure, temperature and engine speed can be monitored in real time. Detailed operating information is available via the Special Menu.
The new wheel loaders will have Grammer seats, which are vertically as well as horizontally air suspended. This design, which cushions movements to the front and the rear, is recommended by orthopedic consultants and is well accepted by operators.
By relocating the reservoir for the wiper water to the outside of the cab, space inside has been increased, providing more foot room. The air conditioning system is regulated automatically by a temperature sensor.
To keep cans and food fresh, a new cooling compartment is standard. There is also more storage room behind the seat.
Durability and Serviceability
All Doosan new generation large wheel loaders have as standard the SKF Vogel Auto Lubrication system. This system increases operational hours and extends the lifetime of the machine.
The lift arm has been strengthened with 10% thicker metal in the arm and the tilt lever.
An automatic front control system allows the operator to save one low and one high position. The boom raise 'kick out' function reduces cycle times and increases operator comfort. 'Return to dig' positions can also be saved.
New kinematics and a larger cylinder on the lift arm have allowed the main pressure in the front hydraulic system to be increased by up to 40 - 70 bar, depending on the machine size, with a corresponding increase in breakout and lifting forces of up to 5%.
A larger opening angle for the side door improves serviceability. A 90° swing-out fan with swing-out side doors provides easy access to the rear for cleaning the new one block radiator. The operator can set and monitor the time remaining to the next service. If the maintenance period is exceeded, a pop-up warning will appear. Increased space in the engine compartment ensures that components such as filters, valves and batteries are within easy reach for service work.