April 13, 2010
With a bucket capacity of 5.2 cubic yards, the DL420 is designed to take on a wide range of material handling tasks from loading and transporting granular material (such as sand and gravel) to industrial, mining and quarrying applications. With the addition of the DL420, the Doosan range of articulated wheel loaders includes eight models with bucket capacities from 1.9 to 6.5 cubic yards.
The 49,163-pound DL420 is powered by a 659-cubic inch, 6 cylinder turbocharged Cummins QSM11 electronically-controlled engine with high pressure unit injector system and a state-of-the-art combustion system. Emissions are well below Tier 3 regulatory limits. The engine develops 280 horsepower at 2,000 rpm and offers maximum torque of 1,070 pound-feet at 1400 rpm for optimal traction and breakout force in loading-transport-handling applications.
Depending on the application, the operator can choose between two working modes (standard or economy) for either maximum productivity or minimum fuel consumption. A robust Z-bar lifting system provides a standard bucket breakout force of 47,210 pounds, among the highest in its size class. This results in higher stripping force and greater productivity when working in hard materials.
The DL420 offers 4 forward speed ranges with maximum speeds of 4, 7.7, 11.4, and 23.6 mph, and 3 reverse speed ranges with maximum speeds of 4, 7.7 and 11.4 mph. Thanks to its powerful Cummins engine, the DL420 accelerates to 90 percent of maximum speed in 2.3 seconds. The larger engine is also designed to provide increased durability and a longer service life.
With a 5.2-cubic yard bucket, the DL420 has a static tipping load of 39,432 pounds (at maximum reach with a straight frame) and a height at bucket pivot point of 14 feet 3 inches. Equipped with a pin-on bucket with bolt-on cutting edge and tipped forward at 45 degrees, the dump height is 10 feet 2 inches and the dump reach is 4 feet 2 inches. The turning radius at bucket edge is 22 feet 11 inches at the maximum steering angle of 40 degrees.
Like all Doosan wheel loaders, the DL420 features a full powershift transmission with manual and automatic modes. Standard limited slip differentials on both the front and rear axles assure positive traction in wet or soft conditions.
Hydraulically controlled, multi-plate wet disc brakes and dual brake circuits provide positive braking power. A spring-applied/hydraulically released (SAHR) parking brake is mounted on the transmission shaft to prevent the loader from rolling after engine shut down. An optional electric-powered emergency steering system backs up the hydraulic power steering system in case of a malfunction and a safety device prevents starting the engine when not in neutral.
The DL420 provides operators with improved visibility and lower cabin sound levels. A powerful heating and air conditioning system, a roomier cabin, ample storage space and a comfortable seat also help to reduce operator fatigue. Anti-pitch control provides smoother travel with a loaded bucket. Available as an option is a single lever control for travel functions and front-mounted attachments.
A new integrated monitoring system displays information about the loader’s engine and transmission, including service intervals for each filter and the engine oil. The monitoring system also provides service fault codes to the operator without the need to hook up a PC. Codes can then be reported to the dealer’s service technician, saving diagnostic time and reducing expense. In addition, the integrated monitoring system allows the transmission to be tuned by the operator without the assistance of a mechanic. The DL420 also features a vehicle control unit that optimizes loader performance by controlling engine, transmission and hydraulic system variables.
To reduce fuel consumption and lower noise levels, the DL420 loader features a hydraulically driven, variable speed engine fan with an electronic thermostat that constantly monitors engine coolant and transmission oil temperatures. The fan direction can be reversed from the cabin to quickly clean out the radiator in dusty environments. Also, the hydraulic fan swings out to easily clean the cooler group.
All routine maintenance on the DL420 can be performed from ground level. Centralized hydraulic check ports and easily accessible drain valves for engine oil and coolant simplify routine maintenance. Remote greasing lubrication ports allow front pins to be lubed from the outside of the machine. The transmission oil filler pipe is located near the articulation joint for easy access and sight gauges for hydraulic oil and coolant levels allow easy daily checks while reducing the risk of contaminants entering the systems.