New Fuel Efficient Doosan DL420CVT-5 Wheel Loader
Doosan is launching the new DL420CVT-5 Stage IV compliant wheel loader, the first model in the Doosan® wheel loader range to be equipped with a Continuously Variable Transmission (CVT). A CVT transmission is composed of a hydraulic motor combined with a hydraulic pump which provides a smooth and continuous speed variation.
The CVT design combines the benefits of a mechanical transmission and a hydrostatic transmission in the same machine. It allows the DL420CVT-5 to automatically transition from hydrostatic power at low speed to the mechanical system to operate at higher speeds.
By combining the two types of transmission, the new CVT technology ensures high loads can be carried at low engine speeds with high dynamics for an optimum wheel loader operating cycle. The DL420CVT-5 therefore provides an increase in machine performance for operators working in digging, loading and lifting applications.
With a maximum bucket capacity of 4.2 m3, the new Doosan DL420CVT-5 wheel loader is intended to meet a wide range of material-handling needs from loading and transporting granular material (such as sand and gravel) to industrial, construction, demolition, mining and quarrying applications.
For most tasks, operators will utilise the hydrostatic part of the transmission, which offers greater fuel efficiency in low-speed applications. The combination of the two transmissions is automatic and fully transparent for the operator.
Up to 15% Additional Fuel Savings
The complete driving range, forwards and in reverse, is controlled by the CVT system. Low engine speeds ensure a high efficiency and the highest driving comfort irrespective of the traction speed. The power splitting continuously variable technology facilitates moving off softly and hydraulically. Furthermore, with the CVT, a fuel saving of up to 15% can be achieved.
The ability to split hydrostatic and mechanical power has allowed Doosan to move to the Scania DC09 engine in the DL420CVT-5, as the CVT system maintains the machine’s efficiency even at low engine rpm. With an output of 232 kW (311 HP) of power at 1800 rpm, the Scania DC09 engine provides generous torque at low rpm and meets Stage IV emission regulations without the need of a diesel particulate filter (DPF), through the use of cooled exhaust gas recirculation (EGR) and selective catalyst reduction (SCR) after-treatment technologies.
On the DL420CVT-5 and all other Doosan wheel loaders, the engine Auto Idle system when activated saves on fuel costs by lowering the idle level from 950 to 750 rpm – when the operator does not give any input to the steering wheel, arm and bucket for more than 10 seconds (ideal for applications where there is a lot of waiting time such as truck loading).
In all DL-5 loaders, the Engine Auto Shut Off shuts down the machine after it has been idling for a specified amount of time (3-60 minutes, configurable by the operator via the control panel). This feature saves on fuel and reduces operating costs.
The engine compartment door size has been increased to provide easier maintenance of engine area. The exhaust and after-treatment system for the engine is installed on the left-hand side of the machine, whilst the components for maintenance are grouped on the right-hand side. All the daily checking of gauges can take place from ground level to ensure it is a quick and safe process.
The impressive breakout force and high traction allow the DL420CVT-5 to tackle the hardest materials, with a powerful hydraulic system that ensures that work is quick and efficient. Combined with the power provided by the Scania DC09 engine, these features gives the DL420CVT-5 excellent penetration power, ensuring an optimum bucket load in each cycle.
As with all Doosan Stage IV wheel loaders, operators can select between several driving modes that adjust the maximum engine rpm based on the operator’s preference and the application.
- Normal: Balances fuel consumption for everyday digging, grading and lifting tasks
- Economy: Reduces fuel consumption for low-demand applications
Two new modes have been introduced:
Digging mode - this mode is available below 3 km/h and by pressing a button, the machine exerts the maximum torque to the transmission to ensure the best performance.
Drive mode - when the machine travels forward at over 14 km/h (or backwards at over 5.4 km/h), with the front pressure stabilized, the loader recognises that the task is driving only and thus shifts automatically into the Drive mode to ensure the best traction and decrease the fuel consumption.
A Creep setting is also available with the CVT transmission. The Creep ‘function’ enables the operator to drive the machine at low speed with no need to press on the accelerator pedal when shifting into forward or reverse. Four Creep settings are available: 0 km/h, 1 Km/h, 2 km/h or 3.1 km/h. This function also avoids the transmission autobrake.
Load-sensing Hydraulic Pumps
All new generation Doosan wheel loaders have a load sensing hydraulic pumping system, whereby the variable axial piston pump generates the flow upon demand in the amount necessary to perform the work. This also gives better traction for penetrating into the stockpile, as less force is necessary to operate the bucket in many situations. Load sensing hydraulics also minimise loss in the hydraulic circuit during a carrying operation in which the loader is usually running, which is an essential technology for wheel loaders. In response to customer feedback, the load-sensing system has been designed so that the bucket has higher priority when the boom and the bucket operate at the same time and there is limited force available.
Joystick control on the new DL420CVT-5 wheel loader is designed to easily combine several movements at the same time. As an option, 3-lever fingertip lever control can be provided for smooth and near-effortless control. Both of these controls use electrohydraulic piloting.
The machine has a Boom Kick-out function as standard, which is useful when working in confined spaces or when repeating similar operations in specific work ranges (for example, when a certain dump height must be reached every day). The same system is used to set the bucket automatically to the Return-to-Dig position.
The LIS (Load Isolation System), often called ‘Ride Control’, provides the operator with a smoother ride over rough terrain and enables a more comfortable ride at higher speeds. The benefits are reduced cycle times, higher productivity and better fuel efficiency while performing load and carry applications. LIS also contributes to longer frame and machine life.
The new loader also offers a ‘third function’ to power a hydraulic system on a work tool, allowing greater machine versatility in a number of applications. The third function valve’s capacity has been increased significantly to at least 250 l/min.
Doosan has also installed an automatic greasing system as standard to reduce working time and increase operating comfort. To facilitate access and mobility on the machine, multiple hand-rails ensure that the operator always has a firm support to hold on to.
The cooling compartment is separated from the engine compartment to prevent warm and dusty air from entering and to allow better control of the air intake. An automatically reversing fan is a standard feature - 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 Comfort Cab
The cab on the DL420CVT-5 demonstrates how Doosan has placed operator comfort at the very centre of its design priorities. Offering generous headroom and an ultra-comfortable, fully adjustable, heated Grammer air suspension seat, the cab features a new steering column design giving more clearance for the operator’s legs and knees. The steering wheel can also be tilted and moved telescopically to match the operator’s preferred position or if they prefer, they can use the convenient and ergonomic electric joystick steering control fixed on the seat armrest which provides a smooth and comfortable drive.
The increased space, better visibility and plentiful storage space in the cab allows operators to work for hours without fatigue or discomfort. Meeting ROPS/FOPS regulations, the cab also offers a wide emergency exit (located on the right hand side) to provide fast and easy evacuation in critical situations.
The 5.7 inch full colour LCD panel is suitable for day and night work. The user-friendly monitor has two customisable screen displays to suit the operator’s preference, giving a full readout of machine settings and maintenance data. The rear-view camera greatly enhances visibility and safety. The screen in the cab shows the operator what the camera sees and includes several lines to help judge distances; it also has other functions, including light intensity control, viewing angle control, language setting and power on/off setting.
On the control panel, all the switches are clearly arranged and within easy reach of the operator. Rocker type switches have been replaced by a multi-selection touch pad. Accurate and smooth joystick controls provide further comfort and operators can save time and reduce the number of operations with the ‘Boom Kick-out’ and ‘Return-to-Dig’ systems. These functions are operated electronically from inside the cab.
The cab air is filtered twice to eliminate all particles larger than 2 microns in size and the fully automatic climate control system adjusts the air temperature and fan speed to maintain the ideal climate setting for the operator. In the DL420CVT-5, as in the larger Doosan wheel loaders, there are also the benefits of several new features as standard, such as the safety handrail bar fixed all around the cab roof. Combined with the large step and platform added in front of the cab, this increases safety for operators moving around the outside of the cab to clean windows with three permanent holding points.
A new, more ergonomic joystick has also been integrated for the operator, offering a new rocker switch for the FNR function and also a new progressive thumb wheel to operate the hydraulic auxiliary line when a hydraulic work tool is being used on the wheel loader.
The front structure in the DL420CVT-5 is more rugged, with much greater rigidity and strength. The Z-bar geometry is designed for heavy lifting with few moving parts. This design also helps stabilise the loader, enables very rapid bucket movements and keeps the bucket at the right angle position at all times. All DL-5 models are available with a High-lift configuration, with a longer arm enabling higher dumping of materials.
DoosanConnect Fleet Management System as Standard
The DL420CVT-5 is factory-installed with the DoosanConnect state-of-the-art wireless fleet monitoring system, a feature available as standard on Doosan wheel loaders and now incorporated in all new DL-5 generation machines. The new DoosanConnect system is a tool designed specifically for the Doosan range, providing comprehensive information about machine performance in a dual mode (satellite, Mobile network).
The DoosanConnect system offers a web-based fleet and asset management solution which is very useful for managing the performance and security of machines and promoting preventative maintenance. The system can support multiple Doosan machines in different locations, helping customers to monitor machine utilisation rates to assess that the right mix of machines is being used; it can also guide drivers to help them to operate equipment with higher efficiency and to locate replacement machines in the event of maintenance work or breakdowns, all under the umbrella of strong anti-theft and theft recovery protection systems.