Doosan has launched three new 23-25 tonne Stage V compliant crawler excavators – the DX235LC-7, DX235LCR-7 and DX255LC-7 models; the 23.3 tonne DX235LC-7 and the heavier 25.7 tonne DX255LC-7 conventional swing excavators are complemented by the 24.3 tonne DX235LCR-7 reduced radius model.
These new ‘DX-7’ models provide significantly higher performance in every area than the previous generation Stage IV machines. They combine enhanced comfort, increased tool carrier capability and novel operator assist technology, with new features to boost fuel efficiency, uptime and return on investment, with a focus on increased power, robustness and agility.
The new DX235LCR-7 reduced radius crawler excavator offers superior digging performance together with flexibility, convenience and low operating costs in a compact design with a rear swing radius of just 1724mm. The DX235LCR-7 meets increased demand for reduced radius machines for work near buildings and in confined areas.
The trend towards reduced radius machines has been driven by the space premium, particularly on inner city and urban construction sites and by the requirement in road and rail construction to keep adjacent lanes and tracks open while working alongside them.
There is a new Tiltrotator Mode on the control panel in all of the new excavators, which can be selected to ensure an optimized hydraulic flow and helps to maximize the accuracy of tiltrotator work by eliminating back pressure. This new tiltrotator mode is a special two-way flow mode, but it is managed by the EPOS like a one way flow mode, with direct return to the tank in each direction, to avoid back pressure and increase flow and controllability.
The heavy 5.0 tonne standard counterweight on the DX235LC-7 and DX255LC-7 models and even heavier 6.4 tonne standard counterweight on the DX235LCR-7 model contribute to the optimised stability and higher lifting capacities of these machines. The DX235LCR-7 and DX255LC-7 can be further enhanced by new optional heavier counterweights, weighing 7.4tonne for the DX235LCR-7 and 5.5 tonne for the DX255LC-7, respectively. These optional heavier counterweights are particularly suited for working with heavier attachments such as tiltrotators.
Doosan has also updated the design of the standard and optional counterweights to provide greater service accessibility, ensuring maintenance work is as convenient as possible.
In common with the other models in Doosan’s new mid-range crawler and wheeled excavators, all of the new 23-25 tonne models have a new smart hydraulic system that offers an improvement of around 30% in attachment work, compared to previous excavator models. The new system applies a smart hydraulic logic for optimal distribution of the hydraulic flowrate when both the arm and attachment are working simultaneously, with a new priority valve and an additional hydraulic line maintaining continuous hydraulic flow to the attachment, even when the arm is being used.
Fine Swing Function
Another standard new feature is the Fine Swing function which minimizes the shaking that a lifted object undergoes at the start or stop of a swing movement with the excavator, to increase the safety of nearby workers and to prevent damage caused by the object falling from the excavator. When Fine Swing activates, the overrun disappears,allowing the excavators to smoothly reach maximum swing speed, whilst removing the shock from the turn reversal at the moment of stopping, resulting in a smooth stop.
The new excavators also incorporate as standard a new lifting eye that forms part of the casting for the push link for the bucket attachment at the end of the arm. The new lifting eye has a maximum capacity of 5 tonne and has a special bush insert to prevent deformation of the lifting hole.
The state-of-the-art cab on the new excavators excels in terms of spaciousness and ergonomics, taking operator comfort and ease of operation to new levels. As well as a new highquality seat, the enhanced cab offers more features as standard than other machines on the market, ensuring super controllability and high precision in all applications.
Smart Power Controls
The enhanced fuel efficiency of the DL06V engine in combination with a new hydraulic main valve and the new generation SPC3 Smart Power Controls provides increased fuel saving. There are four power modes(P+, P, S or E) now available on the new models, which help to simplify the operation of the new excavators and can be set in both one-way and two-way working modes.