Solenoid valves' softer unload

Edited by the Engineeringtalk editorial team Apr 1, 2005

Most two-position, two-way screw-in cartridge pilot solenoid valves utilise a poppet style construction to satisfy low leakage requirements.

Most two-position, two-way screw-in cartridge pilot solenoid valves utilise a poppet style construction to satisfy low leakage requirements.

But now, Sun Hydraulics has adopted a different approach that utilises a precision spool and sleeve design.

Available in both two-position, two-way and three-way pilot solenoid cartridges, Sun said its method produces leakage characteristics equivalent to poppet style designs.

The small pilot solenoid valves are used to unload larger main-stage elements remotely, or by directly integrating the pilot valve in to the main-stage element.

In the latter approach 12 different pilot valves (proportional, solenoid, hydraulic and pneumatic) can be integrated in to a variety of main-stage elements, said the company.

Since control volumes in pilot circuits are typically small, the lower gain characteristics of spool valves produce a softer unload.

To further extend the operating rate, Sun offers a "soft shift" option that adds an orifice in the valve's armature to gain greater control of fluid displacement.

Combining the benefits of a spool valve with the "soft shift" option extends shift times, which can reduce the hydraulic shock generated when unloading main-stage elements, claimed Sun.

The "soft shift" option is offered on all of the company's spool-type solenoid valves.