Atlas Copco PowerMACS 4000, User Manual

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Tightening
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6.5.2.25 SG - Snug Gradient
Step type Id: 32
Parameters : DeltaA (Delta Angle), TcMIN (Min Torque), TcMAX (Max Torque), TSLOPE (Torque Slope),
ASG (Angle run), DIR (Direction).
Function : 1. The spindle is started with the programmed speed in direction DIR.
2. The search for the Snug-point is started as soon as the torque passes TcMIN.
3. The average slope over DeltaA deg is calculated.
4. This is repeated for every DeltaA deg.
5. As soon as two slopes after each other are larger than TSLOPE the Snug-point is found.
6. From this point, the Snug-point, the spindle runs another ASG deg.
7. If the torque level TcMAX is passed without finding the Snug-point the step is aborted
and an event is generated.
Diagram :
Angle
Torque
TcMax Max Torque ASG Angle run
TcMin Min Torque DeltaA Delta angle
TSLOPE Torque slope
Step
TcMin
TcMax
Snug-point
DeltaA
ASG
TSLOPE
DeltaA
DeltaA
Result var .: After the step has finished the angle from the Snug-point to the end of the step can be
checked using the normal angle check (see Check angle) if using the special start condition
"SGP" (Snug Point). If so, the result is reported as the step level result variable "A".
Trace : Angle when ASG has been run from the detected Snug-point is shown as a horizontal line
from step start to step stop in trace when Angle vs. Time is selected. Control parameters
must be enabled in the trace form (see
View of trace curves).