4WEH
* 4/3-, 4/2- or 3/2-way version
* Types of actuation (internal or external pilot control):
– Electro-hydraulic (type WEH)
– Hydraulic (type WH)
* For subplate mounting
* Porting pattern according to ISO 4401
* Spring or pressure centering, spring end position or hydraulic end position
* Wet-pin DC or AC solenoids, optional
* Electrical connection as individual or central connection
* Optional versions:–
– Manual override
– Switching time adjustment
– Preload valve in channel P of the main valve
– Stroke setting and/or spool position monitoring
Product Description
Directional valves type WEH…
The valve type WEH is a directional spool valve with electro-hydraulic actuation. It controls the start, stop and direction of a flow. The directional valves basically consist of the main valve with housing, the main control spool, one or two return springs and, as well as the pilot control valve with one or two solenoids “a” and/or “b”. For unobjectionable functioning, the hydraulic system has to be bled properly.
For valves with three spool positions, the main control spool in the main valve is held in zero position or initial position by means of two springs, for valves with 2 spool positions by pressurization and spring. In the initial position, the two spring chambers and are connected with the tank in a depressurized form via the pilot control valve. Via the control line, the pilot control valve is supplied with pilot oil. Supply can be implemented internally or externally (externally via port X). Upon actuation of the pilot control valve, e.g. solenoid “a”, the pilot control spool is moved to the left and thus, the spring chamber is pressurized with pilot pressure.
The spring chamber remains depressurized. The pilot pressure acts on the left side of the main control spool and moves it against the spring. This connects port P with B and A with T in the main valve. On switching off of solenoid, the pilot control spool returns to its initial position (except impulse spool). The spring chamber is unloaded to the tank.
The pilot oil return is implemented internally (via channel T) or externally (via channel Y).An optional manual override allows for moving of the pilot control spool without solenoid energization.
