Tractors equipped with a control block consisting of proportional directional spool valves of type PSL from HAWE Hydraulik SE, Munich offer farmers maximum flexibility in the use of working equipment.
A new feature of the PSL series is the float position, which is switched by leak-free over-center valves or pilot-operated check valves that are operated by a patented control system. In the float position, the cylinder connections are coupled to the return flow pipe and the piston rod can be moved back and forth by external forces. That allows accessory equipment to be adjusted to the ground contour without the use of force and enables the effective application of seed, pesticides, and fertilizers. The hydraulic hoses between tractor and attachment can be coupled and decoupled in the pressureless state. In the neutral position, the cylinder is fixed so that it is leak-free.
Hydraulic-proportional functions are implemented with the proportional directional spool valves: for example, lifting, lowering, and extending a cutter. Several hydraulic consumer units can be operated simultaneously and independently with different speeds and loads.
The float position is currently available for two of the four sizes in the PSL series. The maximum operating pressure is 420 bar with volume flows up to a maximum of 60 lpm or 120 lpm. All pressurized components are made of steel, which allows for compact construction. It also gives them the robustness required in harsh work environments.
HAWE Hydraulik at Agritechnica 2011
November 13 ‒ 19, 2011
Hall 25, Booth L04
Hanover Fair site
