Patent ID: 9034129
Filing Date: 2015-05-19
Classification: B23K,B29C

Abstract:
1. A method for forming a weld joint utilizing an ultrasonic welding system, the ultrasonic welding system having an ultrasonic welding device with an ultrasonic welding horn, an anvil, an ultrasonic welding controller, a position sensor, and a power adjusting unit, the method comprising: generating control signals for inducing the ultrasonic welding device to commence forming a first weld joint in electrical terminals of battery cells when the electrical terminals are disposed between the ultrasonic welding horn and the anvil, utilizing the ultrasonic welding controller; generating position signals indicative of positions of the ultrasonic welding horn over time, utilizing the position sensor; accessing a desired ultrasonic welding horn position curve utilizing the power adjusting unit, the desired ultrasonic welding horn position curve indicating desired positions of the ultrasonic welding horn over time for obtaining a desired weld joint; receiving position signals from the position sensor at the power adjusting unit, the position signals indicating positions of the ultrasonic welding horn when forming a first weld joint; determining a first displacement of the ultrasonic welding horn utilizing first and second positions of the ultrasonic welding horn at first and second times, respectively, when forming the first weld joint, utilizing the power adjusting unit; determining a desired displacement of the ultrasonic welding horn utilizing third and fourth desired positions of the ultrasonic welding horn from the desired ultrasonic welding horn position curve at the first and second times, respectively, utilizing the power adjusting unit; and generating commands from the power adjusting unit that are received by the ultrasonic welding controller directly from the power adjusting unit to induce the ultrasonic welding controller to increase a power level output by the ultrasonic welding controller to the ultrasonic welding device after the second time if the first displacement is less than the desired displacement, such that upon completion of the first weld joint at a third time an ending position of the ultrasonic welding horn is at a desired ending position indicated by the ultrasonic welding horn position curve, and the first weld joint having a tensile strength in a range of 400-2000 Newtons with a resistivity in a range of 25-100 micro-ohms.