Voith 22000106810, Инструкция по установке и эксплуатации

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91800271810, Protection
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WSR-D80112-S
Design and Functioning
4.2 Function
The way valve is an electro-hydraulic positioner with permanently activated way valve.
This enables variable and basically hysteresis-free positioning of a hydraulic cylinder
equipped with a position transmitter and spring resetting.
For way valve operation, an electric and a hydraulic auxiliary energy are required. All
electric controllers and connections necessary for the way valve operation are
integrated in the Voith control magnet (VRM). The control loop parameters and the
parameters to scale the position of the piston rod are set via potentiometers on the
VRM.
Block diagram - way valve
Fig. 3: Block diagram of way valve
Position control
The way valve is controlled by the control system with an electric signal (4 mA to 20
mA) as position setpoint (w) 0% to 100% for a piston rod. In the VRM position control
loop, this setpoint (w) is compared to the actual position (x) of the piston rod
measured by the position pick-up resulting in a change of the magnetic force (FMag)
of the VRM via the magnetic force controller. This magnetic force moves the control
piston of the gate valve against a control spring, thus changing the magnitude and
direction of the flow rate (Q) to the hydraulic cylinder working chamber. The hydraulic
force resulting from the flow rate effects a movement of the piston rod position (x) in
connection with the compression spring. The piston rod moves into or out of the
actuator with a velocity dependent on the flow rate.
The main control parameters can be adjusted at the VRM from the outside via
potentiometers, thus allowing optimum adjustment of the control for various cylinders
and allocation of the required stroke range to setpoint w.
Function of manual operation knob
Instead of the magnetic force FMag, a force can be set with the manual operation
knob that is transmitted to the tappet and thus to the control piston via the magnet
armature. This permits a movement of the control piston without electrical connection
to thus connect outlet A with P or T. Thus, the piston rod on a cylinder connected on
outlet A can be moved to a corresponding final position. However, it is not possible to
adjust any desired position.