Iconic Diagrams\Hydraulics\Valves\Basic Valves
Domains: Continuous. Size: 1-D. Kind: Iconic Diagrams (Hydraulics).
This model is equal to the four three way proportional valve model, except for the spool position. The spool position is rounded to 0, 1 or -1:
-0.5 < spoolpos < 0.5 => pos = 0
spoolpos >= 0.5 => pos = 1
spoolpos <= -0.5 => pos = -1
The spool dynamics is modeled by a second order transfer function:
sp = SO(f,d,discrete(pos))
which is characterized by the bandwidth (f) and damping (d).
The 4/3-way directional control valve is implemented with various spool centre configurations. The configurations are shown in the picture below:
When you drag and drop a model in the editor, you will be asked which implementation you want to choose. During modeling you can easily change the spool center configuration:
1. | Select the valve model. |
2. | Click the right mouse button to open the right mouse menu. |
3. | Click Edit Implementation and choose another implementation. |
Ports |
Description |
pp, pt, pa, pb, |
All terminals of the valve. |
Causality |
|
fixed volume flow out pp fixed volume flow out pt fixed volume flow out pa fixed volume flow out pb |
|
Inputs |
|
spoolpos |
position of the spool valve: 0 = closed, 1 = open positive, -1 = open negative, -1 <= spoolpos <= 1 |
Parameters |
|
Q_nom
|
Nominal flow at nominal pressure per edge, spool in the open position [m3/s], Q_nom > 0 |
Q_nom_central |
Nominal flow at nominal pressure per edge with, spool in the closed position, Q_nom_central > 0 |
Q_leak p_nom overlap f |
Leakage flow at nominal pressure per edge [m3/s], Q_leak > 0 Nominal pressure per edge [Pa], p_nom > 0 Valve overlap as percentage of full stroke, -1 < overlap < 1. Natural frequency, f > 0. |