Weld electrode plugs with polymeric inserts for loss-of-cooling detection in welding systems

An electric welding system, comprising:

• an electrically conductive weld electrode with a weld shank and a weld cap mounted to a distal end of the weld shank, the weld shank defining therein a coolant bore;
• a coolant subsystem with a coolant fluid source, supply and return conduits fluidly coupling the coolant fluid source to the coolant bore of the weld shank, and a differential flow sensor operable to detect a flow difference of a coolant fluid entering and exiting the coolant bore;
• and
• a loss-of-cooling detection assembly including:
• a plug attached to the weld shank and fluidly coupled to the coolant bore, the plug including a rigid plug body with a clearance hole extending through the plug body;
• and
• an insert detachably mounted inside the plug body and fluidly sealing the clearance hole, the insert being fabricated from a shape memory polymer (SMP) material configured to alter a shape of the insert, responsive to a predetermined temperature change of the coolant fluid in the coolant bore, and thereby detach the insert from the plug body and unseal the clearance hole.

A method of assembling a loss-of-cooling detection assembly for a weld electrode of a welding system, the weld electrode including a weld cap mounted to a weld shank with a coolant bore, the welding system including one or more fluid conduits fluidly coupling a coolant fluid source to the coolant bore of the weld shank, the method comprising:

• attaching a plug to the weld shank such that the plug is fluidly coupled to the coolant bore, the plug including a plug body with a clearance hole extending through the plug body;
• and
• attaching an insert to the plug body such that the insert fluidly seals the clearance hole,
• wherein the insert is fabricated from a polymeric material configured to alter at least one physical property of the insert, responsive to a predetermined change in temperature and/or pressure of coolant fluid in the coolant bore, and thereby unseal the clearance hole.