Valves of type 3WRCBEE are pilot-operated, 2-stage directional high-response cartridge valves. They control the flow direction and size.
Set-up
The valves consist of the following assemblies:
- Cover (1) with connection surfaces,
- Main control spool (7) with control edges,
- Pilot control valve (3) with paired control spool socket unit and inductive position transducer (6)
- Integrated electronics (OBE) (4) with inductive position transducer (12) of the main control spool
Function
- Switching of the main control spool (7) via the pilot control valve (3); pressure build-up in the control chamber (10) acts on the surface (8) – the pressure of the connection A counteracts on the area (11)
- and the spring force (9).
- Control of the control spool of the pilot control valve through the proportional solenoid (5) against the spring force in the pilot control valve.
- Linking the command values (4) and actual values (12 and 6) in the microcontroller of the integrated electronics (OBE) (4).
- Pilot oil supply Y to pilot control valve connection P; pilot oil drain via Y to the container.
- With a command value of 0 V or 12 mA, the electronics controls the main control spool (7) in central position. This way, fifty percent of the system pressure (pP/2) will be set in connection A.
- Area ratio of area (11) to area (8) at:
Failure of supply voltage
- Integrated electronics (OBE) de-energize the solenoid in case of supply voltage failure or cable break
- Depressurizing the control spool surface (8) via the pilot control valve (3) after Y to the container.
- Spring force (9) and pressure in connection A of the area (11) will cause the main control spool (7) to open the connection A to T and close P to A
Notice:
Supply voltage failure will cause an abrupt standstill of the control loop. The acceleration forces occurring in this connection may cause machine damage.
