WP - Wrench Production

STwrench

Control Strategy

The Wrench Production step type can be configured with the following control strategies.

• Torque: This strategy guides the operator is reaching the desired target torque.

• Angle: This strategy guides the operator is reaching the desired target angle.

• Torque or Angle: This strategy guides the operator is reaching the desired target angle or desired target torque.

• Torque and Angle: This strategy guides the operator in tightening a bolt until both target torque and angle have been reached.

• Yield Point: With this strategy, the STwrench detects the yield point automatically. The torque limits specify the range in which the result is OK. Target angle specifies how far beyond the yield point the user may tighten.

• Loose: This strategy is used to loosen a tightened screw.

• PVT compensate with snug: This strategy guides the operator in reaching the desired target torque for joints with prevailing torque, when the prevailing torque level is higher than the final target.

Target Torque

Defines the target torque for tightening step.

Measure torque at

Specifies where the torque will be measured.

Choose between Peak torque or Peak angle.

• Peak torque: The torque value will be set to the peak torque value.

• Peak Angle : The torque value will be set to the torque measured at the peak angle.

Angle search limit

This is an offset that is used to the set the torque result value for a tightening. Measure torque at must be set to Peak Angle for this parameter to be available.

Ratchet time

Numerical value for ratchet time which is by default 5000 ms. This allows the operator to release the torque for a while and recharge during the tightening operation.

If the Ratchet time is exceeded the result of the tightening is marked as NOK with the reason "Tightening timeout".

End cycle time

Numerical value in ms to indicate the end cycle time. Applied when torque goes below the rundown complete

Torque correction coefficient

The parameter is used to correct the torque reading when using an extension or torque multiplier on the wrench. Default value is 1.

Angle correction

The parameter is used to correct the angle reading when using an extension or torque multiplier on the wrench. Default value is 0.

Target Angle

Defines the target angle for tightening step.

Rehit detection

On or Off. Rehit detection can be used to determine when a tightening is a rehit based on the angle limit setting. Angle limit for rehit is enabled if Rehit direction is set to On.

Linear slope coefficient

Linear slope coefficient characterizes the joint stiffness in the linear part of the curve, as torque/angle slope in the Nm/Deg measurement unit.

Compensate value

Choose between Average torque and Peak torque. The Compensate value specifies how the PVT will be calculated.

Average torque - The PVT will be based on an average calculated using the following:

• Delay monitoring

• PVT interval

• PVT distance

• Prevailing torque min

• Prevailing torque max

Peak torque - The PVT will be based on the peak value measured before snug was detected.

Delay monitoring

PVT calculation will not start before this window has been passed, starts at tightening start.

PVT interval

Sets how many degrees the PVT window shall be calculated for, start from the PVT distance point.

PVT distance

Sets how many degrees prior to snug the system shall start the PVT window.

Prevailing torque min

Prevailing torque minimum limit.

Prevailing torque max

Prevailing torque maximum limit