Patent ID: 7491280

Claim:
A method for ultrasonic welding of parts by means of an ultrasonic welding device comprising at least a generator, a converter, and a sonotrode, based on a set curve of a time-dependent welding parameter appropriate to a welding connection meeting set requirements, where the welding duration corresponding to the set curve runs between a starting time t 0 and an end time t e , and a) during the welding of the parts an actual curve of the time-dependent parameter is measured, b) in the period between t 0 and t e the actual curve is compared with the set curve, and c) at least one welding process parameter affecting welding is altered to a value chosen based on a difference between the set curve and the actual curve at a time of comparison, in order that the difference is reduced during welding after the time of comparison and the actual curve converges toward the set curve, and wherein the at least one welding process parameter to be altered consists of one or more of: an amplitude of the sonotrode, a frequency of the sonotrode, a pressure acting on the parts to be welded, a force acting on the parts to be welded, and an energy input into the parts to be welded.