User Manual

ULTRA ADVANTAGE SERVO ROLL FEED 2/10/2003
6
shaft, constantly calculates (updates) its current position. The position of the press crankshaft is determined through the
offset parameter, which is the position of the encoder shaft when the press is in its 0 degree position (TDC).
Thus, at every point of the stroke, the servo drive knows where the crankshaft is. The servo drive controls six cams
simultaneously, turning them on and off accordingly to the cam settings.
Since the PLS encoder is connected directly to the servo drive, there is no need to wire connections for the Feed Cam and
the Reset Cam outputs. These outputs are software type outputs.
The rest of the cam outputs are hardware type and require wiring of output relays to the desired mechanisms, such as a
pilot release solenoid, parts blow-off, tool lubricator, etc. The cam settings (On/Off angles) are set through the operator
terminal. They are part of the tool settings.
NOTE: The Pilot Release Cam output is hardware type output that comes pre-wired .
NOTE: All PLS outputs are active as soon as SRF power is turned on.
2.6 SERVO PILOT RELEASE
The Servo Pilot Release provides a solution for the piloted tools with the press speed over 200 strokes/minute and when
mechanical piloting is not available due to the press design.
The Servo Pilot Release consists of a Servo Motor with Gear Reducer coupled directly to the Feed Roll Release Shaft
and it is controlled by the Slave Servo Drive.
This Slave Servo Drive runs a Roll Release Motion Program, controls its fault conditions, sends Ready and Release-at-
Home signals to the Master Drive and receives the Release signal from the Master Drive.
When the Master Drive sends the Release signal, the Release Drive turns the motor to the preprogrammed Release
Angle, waits until Release signal goes off, turns the motor back to its Home Position and sends the Release-at-Home
signal back to the Master Drive.
If the Master Drive receives a Feed signal before the Release-at-Home, a Release Sync Fault occurs. Auto Mode is
then turned off, and a corresponding message is displayed on the operator terminal.
If during programming, a Pilot Release signal window is programmed to overlap the Feed Signal window, a
corresponding error message will be displayed on attempt to start the feed cycle.
The theory of setting the Pilot Release signal window for Servo Pilot Release isn’t different from traditional set-ups
with pneumatic type releases, but some nuances becomes critical and therefore must be taken into thoughtful
consideration.
When the Release signal is given, it’s often thought of as the instant when the rolls must be open. In reality, there is a lag,
it takes some time (25-30msec) to open the rolls so that the material is actually released. The same occurs when the
Release signal goes off. Press speeds below 200 strokes/minute provide more than enough time for these events. When
the press speed is above 300 strokes/minute this timing becomes more and more critical. Consider the following
example.
Let’s say our press is cycling at 300 strokes/minute (5 strokes/second or 1.8
0
/ms or 200 ms for one revolution).
The Feed signal window is 180
0
(from 260
0
to 80
0
).
The desired release window is 100
0
(from 125
0
to 225
0
).
The time needed for Servo Pilot Release to fully open or fully close the rolls is 16 ms (or 30
0
in our example).
Thus, for the rolls to be fully open at 125
0
they must start opening at 125
0
– 30
0
= 95
0
, therefore, the setting for the
Release “On” signal must be set for 95
0
.
The same with the closing stage, for the rolls to be fully closed at 225
0
they must start closing at 225
0
– 30
0
= 195
0
,
therefore the setting for the Release “Off” signal must be set for 195
0
.
In general, whatever a calculated opening/closing angle is, the Release signal settings must be shifted/advanced for this
angle to achieve a desired Release window. Some trial and error to time the release properly to the specific tool is normal.