DCV 42 PX - MapleSim Help

DCV 42 PX

4-way 2-position directional control valve

Description

The DCV 42 PX component is a four-port, two-position valve. Typically, port 1 is connected to the pressure line, port 2 and port 4 are the outlet ports, and port 3 is the exhaust port.

There are four paths between different ports in this valve, port 1 to port 2 (1-2), port 1 to port 4 (1-4), port 2 to port 3 (2-3), and port 3 to port 4 (3-4). Note that is the minimum sonic conductance for all the paths while there is a specific maximum sonic conductance, ${C}_{\mathrm{max}}$, for each path. There is also a specific critical pressure ratio, $b$for each path.

The sonic conductance for the path between pairs of ports varies as a function of the spool input signal, $s$,  for that path, ${C}_{\mathrm{min}}$, and $\mathrm{band}$. The following table gives the sonic conductance values for the two end values of the spool signal.

 Spool Input 1-2 1-4 2-3 3-4 0 ${C}_{\mathrm{min}}$ ${C}_{\mathrm{min}}$ 1 ${C}_{\mathrm{min}}$ ${C}_{\mathrm{min}}$

Transitions are centered at the midpoint, with the width given by the $\mathrm{band}$ parameter, as shown in the following diagram.

Connections

 Name Description Modelica ID $\mathrm{port1}$ Pneumatic port 1 (pressure) port1 $\mathrm{port2}$ Pneumatic port 2 (outlet) port2 $\mathrm{port3}$ Pneumatic port 3 (exhaust) port3 $\mathrm{port4}$ Pneumatic port 4 (outlet) port4 $s$ Spool input signal s

Parameters

Conductance

 Name Default Units Description Modelica ID $\mathrm{band}$ $0.1$ - Transition length in normalized spool displacement band ${C}_{\mathrm{min}}$ $0$ $\frac{{m}^{3}}{s\cdot \mathrm{Pa}}$ Sonic conductance when the path is fully closed C_min $\mathrm{C__1−2,max}$ $1\cdot {10}^{-8}$ $\frac{{m}^{3}}{s\cdot \mathrm{Pa}}$ Maximum sonic conductance for 1-2 path C_12_max $\mathrm{C__1−4,max}$ $1\cdot {10}^{-8}$ $\frac{{m}^{3}}{s\cdot \mathrm{Pa}}$ Maximum sonic conductance for 1-4 path C_14_max $\mathrm{C__2−3,max}$ $1\cdot {10}^{-8}$ $\frac{{m}^{3}}{s\cdot \mathrm{Pa}}$ Maximum sonic conductance for 2-3 path C_23_max $\mathrm{C__3−4,max}$ $1\cdot {10}^{-8}$ $\frac{{m}^{3}}{s\cdot \mathrm{Pa}}$ Maximum sonic conductance for 3-4 path C_34_max

Critical Pressure Ratio

 Name Default Units Description Modelica ID $\mathrm{b__1−2}$ $0.54$ - Critical pressure ratio for 1-2 path b_12 $\mathrm{b__1−4}$ $0.54$ - Critical pressure ratio for 1-4 path b_14 $\mathrm{b__2−3}$ $0.54$ - Critical pressure ratio for 2-3 path b_23 $\mathrm{b__3−4}$ $0.54$ - Critical pressure ratio for 3-4 path b_34