Resistance welding constant-current control device

Abstract

The invention relates to a resistance welding constant-current control device. The device is characterized in that a sensor is arranged on a welding electrode and is connected with a welding current synchronous circuit; a pedal switch and an electromagnetic valve are separately connected with an optoelectronic isolating circuit; and the welding current synchronous circuit, a net voltage synchronous circuit, a tablet computer, a silicon controlled thyristor drive circuit and the optoelectronic isolating circuit are separately connected with a SCM control unit circuit. The current value collected by the device at a wielding point is calculated by a SCM to compare the actual current value with the defined value, the silicon controlled thyristor control angle of the next welding cycle can be adjusted according to the current power factor, and the constant current electrical resistance welding value can be obtained. The obtained good control effects are as follows: when the net voltage changes between 340V to 420V, the fluctuation of the constant-current control accuracy is less than + / -1%; and the stability and reliability of the long-term operation of the device are high.

Description

technical field [0001] The invention relates to the field of AC electric welding control equipment, in particular to a constant current control device for resistance welding that adapts to changes in power factor during the resistance welding process. Background technique [0002] The control accuracy of the welding current has a great influence on the welding quality in the welding process. In particular, the diversity of resistance welding affects the welding current, such as the shape of the welding arm and the area surrounded by it; resistance welding is a nonlinear process with many uncertain factors and multivariate coupling interactions. At present, the resistance welding microcomputer controller used cannot solve this problem well, and the precision of constant current control is not high, which cannot meet the production requirements of precision resistance welding; the current control mode of the existing resistance welding controller generally adopts PI adjustment...

AI Technical Summary

Problems solved by technology

At present, the resistance welding microcomputer controller used cannot solve this problem well, and the precision of constant current control is not high, which cannot meet the production requirements of precision resistance welding; the current control mode of the existing resistance welding controller generally adopts PI adjustment, The influence of various uncertain factors on the welding process cannot be well compensated by the welding current percentage or the expert database, and the control accuracy of the welding current will be affected accordingly; it is difficult to guarantee the welding quality

Images