Festo DSBC-…-E… - Handbuch (Seite 4)

3.2 Pneumatic fitting
Note
The cylinder can move uncontrolled.
• Avoid 3-way valves for control of the cylinder, especially valves with the
function “mid-position closed” and the design “metallic sealing”.
Leakage air, which flows over the 3-way valve into the cylinder, can release the
locking again after a certain period.
• Use one-way flow control valves (exhaust air flow control) for regulating the
speed of the cylinder (pneumatic control Fig. 2).
Observe thereby the maximum permissible impact energy
(
www.festo.com/catalogue).
4 Commissioning
Warning
Injuries due to uncontrolled moving parts in the environment of the cylinder.
• Make sure that the cylinder is logically correctly controlled.
The locking mechanism can be damaged as a result of incorrect control. Under
certain circumstances this can lead to the piston rod suddenly extending or
retracting.
Note
Damage to the end-position locking due to excessive piston rod forces.
• Make sure that the cylinder chamber lying opposite the end position locking
(opposite chamber) is pressurized with compressed air before each
unlocking.
This relieves the locking mechanism of external forces. Pressurization of the
opposite chamber can be specified through evaluation of the current cylinder
position, e.g. by a higher-order controller.
• Make sure that the maximum holding force is not exceeded ( 7 Technical
data). An unpressurized opposite chamber impairs unlocking: even with low
operating pressure, the locking mechanism may not unlock, be overloaded or
even destroyed.
To set the end-position cushioning (only DNC and DSBC with variant PPV):
Note
Wear of bolt and slot.
An adjusting screw
3 that is screwed in too far (strong end-position cushioning)
can result in the bolt not catching securely.
1. Ascertain the number of turns required of the setting screw for end position
cushioning (by screwing in and out completely).
2. Turn the screw back in half the number of turns.
3. Turn the screw back out, if necessary, until the cylinder piston does not im-
pact too hard.
In the case of an unpressurized cylinder (only with end-position locking ELB, ELV,
E1 or E2):
• Make sure that the piston rod is not retracted or extended. Otherwise, the bolt
will brush against the end position lock on the piston rod. This will lead to pre-
mature wear and to impairments of functioning (
chapter 3.1, section “to
permanently unlock while setting”).
If several cylinder with end-position locking are used:
• Avoid parallel operation of cylinders for movement of an individual workpiece.
Otherwise, there is a possibility that one of the end position locks will not unlock
at the right moment.
5 Operation
Note
No unlocking of the end position.
• Make sure that the cylinder always reaches its internal end position.
External stops can shift the end position.
Possible consequences:
– the internal end position is not reached
– the end-position locking does not latch
– the locking mechanism wears prematurely.
If used in a dirty environment (e.g. dust, splash-water):
• Fasten a fitting (B) and a tube to the orifice
2 of the
end-position locking ( 7 technical data).
• Remove the tube from the dirty area to prevent ingress
of dust and splash-water.
These measures can lead to an increase in the required
operating pressure for unlocking. In addition, the unlock-
ing and locking times are extended.
Fig. 6
2
(B)
To check the end-position locking:
1. Vent the cylinder.
2. Pressurize the cylinder with the application-specific load.
Observe thereby the max. holding force ( 7 Technical data).
• Make sure that no damage can occur if the end-position locking does not catch.
6 Trouble-shooting
Malfunction Possible cause Remedy
End position
is not locked Wear Send to Festo Service
Order new cylinder
Excessive exhaust air flow control Open flow control valve
Permanent manual unlocking Unscrew screw from orifice 2
The internal end position of the
cylinder is not reached. Do not use any external stops
(internal end position must always
be reached)
Too long and narrow connecting
cable between the valves and the
cylinder Use short connecting cable with
cross section that is as large as
possible
Dirty silencers Replace silencers
End position
is not unlocked Permanent manual locking Unscrew screw from orifice 2
Operating pressure at the cylinder
too low Increase operating pressure
(
7 Technical data)
Connection at the orifice 2 clogged Clean end-position locking or
connected tubing connection
Unpressurized opposite chamber Pressurize the opposite chamber
before each unlocking
(
4 Commissioning)
7 Technical data
ADN-/DNC-/DSBC-...-E... 20 25 32/40 50/63 80/100
Function Double-acting cylinder with single-acting interlock
through spring force
End-position locking
– ADN/DNC-...-ELB, DSBC-...-E1 At both ends
– ADN/DNC-...-ELV, DSBC-...-E2 To the front
– ADN/DNC-...-ELH, DSBC-...-E3 At the rear
Operating medium (at the cylinder) Compressed air to ISO 8573-1:2010 [7:4:4]
Thread at orifice 2 M3 M5
Max. axial backlash with end position locked
– ADN/DNC 1) [mm] 1.3 2.1
– DSBC
1)
[mm] 1.3 1.5
Maximum holding force of the
end-position locking
2)
[N] 250 500 2000 5000
Permissible temperature range [°C] –20 ... +80
Operating pressure
– for unlocking [bar] min. 2.5 min. 1.5
– for locking (residual
pressure)
[bar] max. 0.5
– maximum at ADN-…-EL… [bar] 10
– maximum at DNC-…-EL… [bar] 12
– maximum at DSBC-…-E… [bar] 12
Materials (end-position locking)
– housing, cover, piston, spring Steel
– cushioning seal Polyurethane
– guide ring Polyacetal/polyethylene
1) The specifications are calculated values - in the hold direction, without load.
2) But no more than 50 % of the theoretical cylinder force (recommended values
www.festo.com/catalogue).