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VALVES
Calculation of flow at 3
bar
:
C
=
Q
Q
=
C
* (
P
rel
+
P
ass
)
Q
3
= 13 * (3+1)
Q
3
=
52
Nl / min
Q
3
=
0,86
Nl / sec
(
P
rel
+
P
atm
)
Dividing the quantity of air enclosed within the exhaust chamber with the value of flow exiting the regulator it is
possible to obtain the required time for the stroke of the cylinder:
t
=
V
3
t
=
5
t
≅
5,8
sec
Q
3
0,86
Adjusting the number of revolutions of the regulator changes the value of the exhaust flow thereby increasing or
reducing the speed of the cylinder.
Themovement speed, i.e. the time required to complete the cylinder stroke does not change even if the pressure
changes.
Suppose that the previous cylinder completes thenegative strokewithout a load, and in the positive chamber there
is a higher-pressure value, for example 6
bar
. The quantity of air to be discharged is greater than in the previous
case as is the quantity of air that is released into the atmosphere.
Calculation of the volume of the exhaust chamber
V
6
:
V
6
=
V
S
* (
P
+ 1)
V
6
=1,25
*
(6+ 1)
V
6
=
8,75
Nl
We leave the number of revolutions of the adjustment screw (6) unchanged and we calculate the flow of free air
at a value of 6
bar
:
Q
=
C
* (
P
rel
+
P
ass
)
Q
6
= 13
*
(6+1)
Q
6
=
91
Nl / min
Q
6
=
1,51
Nl / sec
Dividing the quantity of air enclosed within the exhaust chamber with the value of flow exiting the regulator it is
possible to obtain the required time for the stroke of the cylinder.
t
=
V
6
t
=
8,75
t
≅
5,8
sec
Q
6
1,51
The change in pressure does not influence the time of a cycle.
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