Doosan has introduced five Tier 4-compliant crawler excavators: the DX140LC-5, DX140LCR-5, DX180LC-5, DX225LC-5, and DX235LCR-5.
The 14-metric-ton 113-horsepower DX140LC-5 and DX140LCR-5 machines replace the Tier 4-Interim “dash-3” models. The DX140LCR-5 model offers a shorter tail swing, and both units come standard with permanently sealed and lubricated track links. The bushings and hard-wear disks are designed for reliability as well as extended service intervals, the company says.
The 129-net-horsepower Doosan DX180LC-5 crawler excavator replaces the Tier 4-Interim DX180LC-3 crawler excavator. Improvements include an enhanced LCD screen, emergency engine stop and an upgraded alternator.
Both the DX225LC-5 and DX235LCR-5 Tier 4-compliant machines replace the Tier 4-Interim DX225LC-3 and Tier 3 DX235LCR models. The DX225LC-5 is a 162-horsepower unit; the DX235LCR-5 is rated at 181 horsepower. With a near-zero reduced tail swing, the DX235LCR-5 can work close to buildings and in confined areas. The DX235LCR-5 is designed to operate in congested jobsites such as roadways and rail lines without blocking traffic in the adjacent lane or track, and it minimizes the potential for damage when working close to buildings or walls.
All five excavators feature Doosan’s selectable Smart Power Control (SPC) feature, which consists of two systems—Variable Speed Control and Pump Torque Control—that work together to improve machine efficiency while maintaining productivity and reducing fuel consumption. The engine control unit automatically manages SPC when SPC is engaged. Each of the four power modes will function with SPC engaged or disengaged; however, SPC can be active only in the Digging work mode.
Specifically, Variable Speed Control reduces engine rpm during low workload requirements such as during the swing portion of a dig cycle. This reduces the total energy required to perform a task and improves fuel efficiency by up to 3 to 7 percent, according to the company. Pump Torque Control matches hydraulic pump torque and engine response to the task, preventing engine overload and excess fuel consumption.
Doosan has also added an auto-shutdown system to its excavators to help owners save fuel during non-working conditions. Operators can configure the idle time from 3 to 60 minutes. When enabled, the feature will shut down the excavator’s engine when the preset idle time is met.