Siemens Sinumerik 840D Series Function Manual page 245

10.03
Nominal flowrate
Asymmetric flow
characteristic
Dynamic response
 Siemens AG, 2003. All rights reserved
SINUMERIK 840D/SIMODRIVE 611 digital, HLA Module (FBHLA) - 10.03 Edition
This expresses the flow rate with fully opened valve in relation to a specific
pressure drop per control edge.
Typical nominal flow rate for directly-controlled servo solenoid valves (nominal
pressure drop of 35 bar per control edge):
S
Size 6: Q=4...40 l/min
S
Size 10: Q=50...100 l/min
Typical nominal flow rate for pilot-controlled servo solenoid valves (nominal
pressure drop of 5 bar per control edge):
S
Size 10: Q=55...85 l/min
S
Size 16: Q=120...200 l/min
The flow under other pressure conditions is calculated according to the law of
flow by the following formula:
@
Q =Q
X nom
See Subsection 2.3.2 for a description.
The dynamic characteristics provide information on the servo solenoid valve's
ability to respond to rapid signal changes.
One simple expression of the dynamic response is the actuating time. This is
the time that the valve spool requires in order to adjust to a jump in the valve
spool setpoint of typically 0 to 100%.
More exact information about the dynamic response is provided by the Bode
diagram or frequency response. In this case, a sinusoidal setpoint is applied to
the valve. The amplitude ratio and phase shift curves are then determined via
the frequency from the actual and setpoint values of the valve spool. The valve
frequency response is highly dependent on the setpoint amplitude, which
should therefore be specified as a parameter. The dynamic response of servo
solenoid valves is of particular interest in the range of smaller signal
amplitudes of 5 to 20% * U
I
[dB]
O
2
0
-2
-4
-6
-8
-10
Fig. A-11 Dynamic response of valve
A.1 Servo solenoid valves
∆p
X
∆p
nom
.
nom
5 %
100
at -3 dB
Signal 100 U
max
Signal 5% U
max
10 20 40 60 80100 200 300
A Hydraulics
ϕ [°]
-180
-160
-140
-120
-100
at -90°
-80
-60
-40
-20
-0
f [Hz]
A-245