Festo OVEM, Operating Instructions Manual

Page: 77 / 111

OVEM
Festo – OVEM – 1407c English 77
The vacuum suction nozzle must be in its initial position (RUN mode).
Define the desired switching characteristics of the switching outputs (
è
chapter 6.3, page 84).
The workpiece must be held reliably against the suction gripper by the vacuum generated.
The intensity and duration of the ejector pulse can be adjusted.
You can set the intensity of the ejector pulse by adjusting the flow control screw
aJ
.
1. Screw the flow control screw
aJ
clockwise completely in.
è
The ejector pulse channel is now closed. No ejector pulse is generated.
2. Unscrew the flow control screw until the required intensity of the ejector pulse is reached.
You can set the duration of the ejector pulse in the EDIT mode (
è
chapter 6.3.3, page 87).
3. Test the settings of the ejector pulse before commissioning.
Reducing the vacuum:
OVEM-...-CN/-ON
Cut off the compressed air supply by switching the input voltage off (in the case of -CN) or on (in the
case of -ON).
è
The vacuum port
5
is pressurized. The workpiece detaches itself from the suction gripper.
OVEM-...-CE/-OE
Switching the input voltage off (for -CE) or on (for -OE) switches the second solenoid valve and gen­
erates an ejector pulse.
è
The vacuum port
5
is pressurized. The workpiece detaches itself from the suction gripper.
Note
Switching the input voltage on (for -CE) or off (for -OE) during the ejector pulse switches
the solenoid valve into the initial position and no more ejector pulse is generated.
Note
When large suction cups are used, flow resistance in the suction cup as the cup lifts
away from the workpiece can cause the buildup of a vacuum independent of the gener­
ating device. This might mean that the workpiece being set down does not detach from
the suction cup, even when the ejector pulse is set to a long duration.
Therefore, the input voltage should be switched off (for -CE) or on (for -OE) shortly be­
fore the suction cup is lifted away, to ensure that the ejector pulse is active while the
suction cup lifts away.