Drag Torque monitors the amount of torque required to rotate a particular assembly part. It measures intentional & unintentional interference that fits between components by measuring torque peaks, valleys, and average. This allows the user to verify compliance with pre-set Quality Control levels. The Drag Torque step must be the only step in the PSET.
There are two zones associated with the Drag Torque step: The Cut-in zone and the Drag Torque zone. The Cut-in zone is the first segment of the step. It provides an inspection zone during the start-up inertia or "Cut-in" torque area encountered by the tool during the step. It is used to identify poor quality conditions of the assembly being tested. (e.g. undersized hole, tightening obstruction). A failure (High torque) in the Cut-in zone stops the step with a fault declared. The Drag Torque zone is the second segment of the step and is entered after a successful completion of the Cut-In zone. It provides a monitoring zone (for Peak, Valley, and Average Drag torque) while the tool is running.
NOTE: Average Drag torque is one of the data values determined from the Drag Torque zone. It is calculated using a moving average of up to the last 360 degrees of running torque prior to the end of the Drag Torque zone.
Drag Torque specific parameters associated with the Cut-In Zone:
|Identifies the measured Torque where the Drag Torque step begins.|
|Cut-In Torque High Limit||
|Cut-In Angle||Identifies the amount of socket angle rotation to complete the Cut-In zone. Measurement begins once Snug torque is reached.|
Drag Torque specific parameters associated with the Drag Torque
|Target Inspection Angle||Identifies the programmed amount of socket angle rotation during the Drag Torque zone. Measurement starts once the Cut-In zone has been exited.|
|Torque High Limit||Identifies the maximum amount of torque allowed during the Drag Torque zone. If measured torque equals or exceeds this limit the step is halted and a fault declared. Measurement starts once the Cut-In zone has been exited.|
|Torque Low Limit||Identifies the minimum amount of torque that must be encountered during the Drag Torque zone. The minimum torque encountered during the Drag Torque zone is stored while in the zone. When the Drag Torque step is complete the stored minimum is checked to make sure it is greater than this limit. If it is not then a fault is declared. Measurement starts once the Cut-In zone has been exited.|