With their CAN interfaces the PSL hydraulic proportional directional spool valve by Hawe Hydraulik SE (Germany) enable synchronous usage of all functions in excavators. To achieve this, the company uses electronics instead of downstream pressure compensators.
THE VALVE'S ELECTRONICS DEMONSTRATED in Munich (Germany) at Bauma 2013 can adjust the volume flow for all functions if the pump comes to its displacement limits. This is done through the targeted prioritizing of which function keeps full performance and which is reduced. The programmable valve control constantly collects data via CAN from the joystick, pump and combustion engine and it calculates the priority of functions requested by the excavator's driver. This selectable distribution of volume flow can be adjusted to different application profiles and energy-saving modes.
The CAN communication also enables a dynamic activation of the work functions. It is possible to pre-calculate the back pressures at pulling loads so that the dynamic excavation is low-loss and still free of cavitation.
News and reports