Working Principle - SMC Networks AV2000 Manual

AV2000/3000/4000/5000

Working Principle

1 ( P )
Working Pressure
Pilot valve
condition conditions
1/2 P > P
P A
ON
1/2 P ≤ P
P A
1/2 P
P =
approx. P
A
—
OFF
3
B
ON OFF
B
3 ( R )
Working description
When pilot valve is turned ON by ener-
gization or manual override, the pilot air
pushes piston A and main valve
downward and opens main valve
R port closes simultaneously. The air from
P port moves to needle valve
flow is adjusted, and flows to A port. The
meter-in control of needle valve
moves the cylinder from to
A B
When 1/2 P ≤ P after the cylinder rea-
P A
ches , piston B fully opens and P
B
creases rapidly as shown from
becomes the same pressure as P
Since piston B holds the fully open condition, during normal operation the
cylinder's speed will be controlled by the usual meter-out control.
When pilot valve is turned OFF, spring
upward and opens R port while shutting off the air supply from P port. The
pressure difference generated at this time opens check valve
pressure on the A port side is quickly exhausted from R port.
2 ( A )
Pressure time chart (meter-out control) example
Initial operation return stroke
while
, where its
P
P
slowly
.
P
R (atmospheric pressure)
A
in-
A
to and
C D
P.
pushes piston A
B-B
Cylinder drive circuit (meter-out control) example
P
P
B
1(P)
D
C
P
A
Time
P
P
1(P)
P
P
and main valve
1(P)
and the residual
P
A
2
2(A)
1
3(R)
P
A
2
2(A)
1
3(R)
P
A
2
2(A)
1
3(R)