System and method for performing resistance spot welding

摘要

A probeless energy delivery controller for a resistance spot welding system includes a power supply module that generates a first current and a power delivery module configured to generate a second current from the first current. The current is delivered to a first electrode and a second electrode that have at least two weld pieces interposed there-between. As the current flows through the weld pieces, the resistance and temperature of the weld pieces increase such that the weld pieces melt. The system further includes a voltage control module that receives a current reading indicating a value of the second current, estimates a resistance of the weld pieces based on the value of the second current, and determines a phase angle for setting a voltage outputted by the power supply module based on the estimated resistance and a power profile. The power supply module generates the first current based on the phase angle.

主权项

1. A spot welding system comprising:
a power supply module configured to generate a first current; a power delivery module configured to receive the first current from the power supply module and to generate a second current from the first current; a first electrode and a second electrode configured to resistively spot weld at least two weld pieces interposed between the first and second electrode by receiving the second current, thereby causing the resistance and temperature of the weld pieces to increase such that the weld pieces melt; and a voltage control module configured to receive a current reading indicating a value of the first current, estimate a resistance of the weld pieces as a result of the second current flowing through the weld pieces based on the value of the first current and independent of a voltage difference across the first and second electrodes, and determine a phase angle value for setting a voltage outputted by the power supply module based on the estimated resistance and a power profile that indicates an amount of power to be delivered by the power delivery module over a period of time, wherein the power supply module adjusts the first current based on the determined phase angle value.