E025
7
Q/
∆
P DIAGRAMS
based on mineral oil ISO VG 46 at 50°C
11
DEVICES FOR SWITCHING TIME CONTROL FOR DKE AND DKER
These devices are only available for DC valve version and can control the switching time and the-
refore reduce the coil hammering in the hydraulic circuit. The different types are available shown in
the figure.
The functionality of the device time control depends on the type of regulating element.
-
L
:
controls and regulates the switching time in both moving directions of the spool: regulation is
carried out by screwing/unscrewing the element itself (regulating choke);
-
L1/L2/L3
: controls the switching time in both moving directions of the spool by means of fixed
calibrated restrictor (gauged flow)
ØL1 = 1,25 mm; ØL2 = 1 mm; ØL3 = 0,75 mm;
-
LR
: controls and regulates the switching time in the b
→
a direction of the spool movement. The
device does not control the switching time (standard time) in the opposite direction a
→
b of
the spool movement.
For a correct operation of the switching time control, the passage in which the control device is
installed must be completely filled with oil.
0, 0/1, 0/2, 2/2
A
A
B
B
1, 1/1, 1/3, 6, 8
A
A
D
C
3, 3/1, 7
A
A
C
D
4
B
B
B
B
F
5
A
B
C
C
G
1/2
B
C
C
B
2/7
D
F
5/7
B
A
E
19
A
D
C
H
Flow direction
Spool type
P
→
A P
→
B A
→
T B
→
T P
→
T B
→
A
SPOOL DIRECTION
a
→
b = sol. energizing “a” / sol. de-energizing “b”
a
←
b = sol. energizing “b” / sol. de-energizing “a”
9
SWITCHING TIMES
(average values in msec)
DKE / DKER + SP-666 / SP-667
40
60
25
35
DKE / DKER + SP-669
60
––
90
––
DKE-*/L* - DKER-*/L*
––
75÷150
––
45÷150
Valve
Switch-on
Switch-on
Switch-off
Switch-off
AC
DC
AC
DC
Test conditions:
- 50 l/min; 150 bar
- nominal supply voltage
- 2 bar of back pressure on port T
- mineral oil ISO VG 46 at 50°C
The elasticity of the hydraulic circuit and the
variations of the hydraulic characteristics
and temperature affect the response time.
DKE / DKER + SP-666 / SP-667
7200
15000
Valve
AC
DC
(cycles/h)
(cycles/h)
DKE, DKER
Valve pressure drop
∆
p [bar]
Flow rate [l/min]
G
F
E
D
C
B
A
H
Flow rate [l/min]
Inlet pressure [bar]
V
Inlet pressure [bar]
Flow rate [l/min]
DKE - DC
DKE, DKER
DKE - AC
M
Y
S
V
8
OPERATING LIMITS
based on mineral oil ISO VG 46 at 50°C
The diagrams have been obtained with warm solenoids and power supply at lowest value (V
nom
- 10%). The curves refer to application with symmetrical flow
through the valve (i.e. P
→
A and B
→
T). In case of asymmetric flow and if the valves have the devices for controlling the switching times the operating limits
must be reduced.
Y
V
Y
S
M
M
0/1, 5/7, 1/3
S
2/7, 4, 5, 19
1/3, 5/7, 6, 7
Y
1, 1/2, 0/2
4, 5, 2/7
V
6, 7, 8, 2/2
2/2
T
0, 1/1, 3, 3/1
19
Curve
Spool type
AC
DC
Flow rate [l/min]
Inlet pressure [bar]
T
Inlet pressure [bar]
Flow rate [l/min]
DKER - DC
DKER - AC
M
V
Y
T
S
10
SWITCHING FREQUENCY
T
T
M
S
V
Y
0, 0/1, 1, 1/1, 3,
3/1, 1/2, 0/2, 8
