Directional valve Bosch Rexroth art. 0811404626

General information
The high-response valve type 4WRPEH is a direct operated directional control valve with electric position feedback and integrated electronics (OBE). In the integrated electronics (OBE), the specified command value is compared with the position actual value. In case of control deviations, the stroke solenoid will be activated which – due to the changed magnetic force – adjusts the control spool against the spring. Stroke/control cross-section is controlled proportionally to the command value. In case of a command value presetting of 0 V, the electronics adjusts the control spool against the spring to central position. In deactivated condition, the spring is untensioned to a maximum and the valve is in fail-safe position.
Switch-off behavior
With switched-off electronics, the valve will immediately move into the relevant secured basic position (fail-safe). In this connection, it moves through the switching position P–B/A–T which may result in movements at the controlled component. This has to be considered in the system design.

Valves type 4WRPEH are direct operated directional control valve with electrical position feedback and integrated electronics (OBE).
Set-up
The 4WRPEH high-response valve mainly consists of:

• Valve housing with control spool and sleeve in servo quality (1)

• Control solenoid with position transducer (2) (optional with electronics protection membrane (5))

• On-board electronics (OBE) (3) with analog or IO-Link interface (4) (optionally with damping plate (6))

Function
The integrated electronics (OBE) compares the specified command value to the position actual value. In case of control deviations, the stroke solenoid will be activated. Due to the changed solenoid force, the control spool is adjusted against the spring. Stroke/control spool crosssection is controlled proportionally to the command value. In case of a command value presetting of 0, the electronics adjusts the control spool against the spring to central position. In deactivated condition, the spring is untensioned to a maximum and the valve is in fail-safe position.
Control solenoid shut-off
In case of the following faults, the control solenoids are de-energized by the integrated electronics (OBE) and the control spool is set to fail-safe position:

• Falling below the minimum supply voltage

• Only at interface “F1”:

• Falling below the minimum current command value of 2 mA (includes cable break of the command value line (current loop))

• Only at interface “L1”:

• Enable inactive, communication interruption (watchdog)

• In case of internal IO-Link error

• Only at interface “C6”:

• Additionally release inactive

Damping plate “D”
The damping plate reduces the acceleration amplitudes on the on-board electronics (frequencies >300 Hz).
Notice:
Use of the damping plate is not recommended for applications with mainly low-frequency excitation <300 Hz. Electronics protection membrane "-967" To prevent condensate formation in the housing of the integrated electronics (OBE), an electronics protection membrane (5) can be used. Recommended for use outside industry-standard conditions with high ambient air humidity and significant cyclic temperature changes (e.g. outdoors).