Doosan Infracore has officially launched the "Full-Electric" main control valve system for its DX245LC-5 and DX300LC-5 excavator series. Traditional excavators use hydraulic pilot lines to control the spools in the main valve. This creates "hysteresis" (lag) due to the compressibility of the pilot oil, making fine grading difficult.
The new system replaces the hydraulic pilot lines with "Proportional Electric Solenoids" acting directly on the valve spools. Each spool is equipped with a "Linear Variable Differential Transformer" (LVDT) position sensor. This sensor feeds the exact position of the spool back to the ECU. The engineering innovation is the "Position Closed-Loop Control." When the operator moves the joystick, the ECU calculates the required spool displacement. It sends a current to the solenoid. The LVDT measures the actual movement. If the spool sticks or moves too slow, the ECU instantly increases the current to force the spool to the target position.
Furthermore, the system features "Independent Flow Control." In traditional valves, moving the boom often reduces flow to the arm (saturation). The electric system monitors the pressure drop across each spool. It independently adjusts the opening of each valve to ensure simultaneous operations (e.g., traveling and swinging) do not interfere. This electric control reduces hydraulic heat generation by 15% and allows for "Software-Defined" flow curves, meaning the dealer can tune the machine's "feeling" without changing hydraulic hoses.
