Proportional directional spool valve, type PSL, with CAN-BUS interface

A control for excavators that enables synchronous usage of all functions without performance limitations is both comfortable and economical. With their CAN technology the controls from HAWE Hydraulik SE, Munich, assist in meeting this requirement.

The controls are suitable for lighter and heavier excavators and can adjust volume flows for all functions if the pump comes to its displacement limits. This is achieved through targeted prioritizing which function shall keep up full performance and which shall be reduced. Where the competitors provide solutions using downstream pressure compensators, HAWE Hydraulik is counting on electronics: the programmable logic valve control constantly collects data from the joystick, pump and combustion engine and calculates the priority of functions requested by the excavator's driver. This freely selectable distribution of volume flow can be adjusted to various different application profiles and energy-saving modes.

The CAN-technology also enables a very dynamic activation of the work functions. Thus, with the high-dynamic PSL proportional directional spool valve, it is possible, for example, to steer the excavator bucket in such a way that the hydraulic cylinder pulsates forwards and backwards and thereby penetrates more effectively when operated in blow mode. The spool in the proportional directional spool valve has been optimized for finely controlled movements so that a fully extracted boom can be positioned centimeter-wise in its upward and downward movements. Moreover, it is possible to pre-calculate the back pressures at pulling loads so that the dynamic excavation is low-loss and still free from cavitations.

Ancilliary blocks with shock and suction valves, as well as adjusted intermediate plates are available to extend the hydraulic control with additional functions.

HAWE Hydraulik at the bauma 2013
April 15-21, 2013
Hall A4, Booth 218, at the Messe Munich