SMC Networks ITV Series - Series ITV209 Vacuum Regulator Working Principle; Operational Diagrams and Performance Data

F.R.L.
AV
AU
AF
AR
IR
VEX
AMR
ITV
IC
VBA
VE
VY1
G
PPA
AL
Working Principle
Series ITV209
Pressure
display
i Control
circuit
w
Atmospheric pressure
solenoid valve
Atmospheric
pressure
Power supply
Input signal
Output signal
q Vacuum pressure
solenoid valve
u Pressure sensor
e Pilot chamber
t
Vacuum pressure
valve
y Atmospheric pressure
valve
OUT.
(Set pressure)
ATM
(Atmospheric pressure)
VAC
(Vacuum pump, etc.)
r Diaphragm
Working Principle
Block Diagram
When the input signal increases, the vacuum pressure solenoid
valve q turns ON, and the atmospheric pressure solenoid valve
w turns OFF. Because of this, VAC and the pilot chamber e are
connected, the pressure in the pilot chamber e becomes
negative and acts on the top of the diaphragm.
As a result, the vacuum pressure valve t which is linked to the
diaphragm r opens, VAC and OUT are connected, and the set
pressure becomes negative.
This negative pressure feeds back to the control circuit i via the
pressure sensor u. Then, a correct operation works until a
vacuum pressure proportional to the input signal is reached, and
a vacuum pressure is obtained which is always proportional to
the input signal.
VAC.
Input
signal
Set
pressure
+
–
u Pressure sensor
Pilot valve
Output pressure (kPa)
0
–20
–40
–60
–80
1
0.5
0
–0.5
–1
Linearity
Pressure
Characteristics
Hysteresis Repeatability
0 25 50 75 1000 25 50 75 100
–100 –80 –60 –40 –20
0 2 4 6 8 10
Input signal (% F.S.)
VAC side pressure (Supply pressure) (kPa)
Input signal (% F.S.) Count
Output deviation factor (% F.S.)
Output deviation factor (% F.S.)
1.0
0.5
0
–0.5
–1.0
1.0
0.5
0
–0.5
–1.0
Output deviation factor (% F.S.)
Return
Out
Set pointSet point
Flow
Characteristics
50 100 150
Flow rate (
l /min(ANR))
Set pressure (kPa)
0
–10
–20
–30
–40
–50
–60
–70
–80
–90
Set pressure: –20 kPa
Supply pressure: –100 kPa
Flow characteristics
measurement conditions
r
Diaphragm
q
Vacuum
pressure
solenoid valve
w
Atmospheric
pressure
solenoid valve
• Exhaust flow rate of the vacuum pump
used for measurement: 500 l /min (ANR)
• Inlet vacuum pressure: –100 kPa
(When outlet flow rate is 0 l/min (ANR))
• Maximum flow rate: 132 l /min (ANR)
(With inlet vacuum pressure at –39 kPa)
t
Control
circuit
14-8-31
Downloaded from Elcodis.com electronic components distributor