Weld head

Abstract

A weld head for spot welding two or more components together. The weld head includes first and second electrode assemblies and a linear actuator motor to drive the first electrode assembly into a desired position and apply a desired clamping force. The weld head also includes a temperature sensor coupled to the linear actuator motor and configured to measure a temperature of the linear actuator motor. The weld head also includes a controller configured to monitor the temperature measured by the temperature sensor and, based upon the temperature, adjust the current supplied to the linear actuator motor to maintain the desired clamping force.

What is claimed is: 
     
         1 . A weld head configured to spot weld two or more components together, the weld head comprising:
 first and second electrode assemblies configured to supply a weld current through the components;   a linear actuator motor configured to drive the first electrode assembly into a desired position and to apply a desired clamping force to the components;   a temperature sensor coupled the linear actuator motor and configured to measure a temperature of the linear actuator motor; and   a controller configured to monitor the temperature measured by the temperature sensor and, based upon the temperature, adjust the current supplied to the linear actuator motor to maintain the desired clamping force.   
     
     
         2 . The weld head of  claim 1 , wherein the temperature sensor is a thermistor. 
     
     
         3 . The weld head of  claim 1 , wherein the first electrode assembly comprises:
 an upper adapter; and   a lower adapter detachably coupled to the upper adapter, wherein the lower adapter is configured to detachably receive an electrode.   
     
     
         4 . The weld head of  claim 1 , further comprising a brake configured to move between an engaged position in which the position of the first electrode assembly is locked and a disengaged position in which the linear actuator motor is free to drive the position of the first electrode assembly. 
     
     
         5 . The weld head of  claim 4 , wherein:
 the brake is configured to move into the disengaged position when power is supplied to the brake; and   the brake is configured to move into the engaged position when the power is cutoff from the brake.   
     
     
         6 . The weld head of  claim 5 , further comprising an actuator arm coupling the linear actuator motor to the first electrode assembly. 
     
     
         7 . The weld head of  claim 6 , wherein the brake comprises:
 a spring-loaded brake configured to engage and disengage a plurality of grooves in the actuator arm; and   a solenoid configured to drive the spring-loaded brake.