Research On Precision Seam Welding Machine

Resistance seam welding (RSW) of high efficiency and easy operation has been widely introduced in oil drums, tin cans, aircraft and automotive fuel tanks, as well as a number of sheet welding of sealed containers. Micro-parts and thin sheet have been widely used in the industrial and household utensils. However, it is difficult in welding and accurate heat-control of welding due to their small size. The traditional resistance seam welding machine can barely meet this requirement and the presence of more precision resistance seam welding machine become necessary.The precision of resistance seam welding machine is mainly reflected in the precise power technology and precise mechanism. According to the requirements of precision power technology, the project with 4 kHz inverter frequency, takes PIC18F6585 microcontroller as the core of power supply control system. The hardware circuit of the control system is designed, including the IGBT drive circuit, the current sampling circuit and the RMS processing circuit; the control system software and the human-computer interaction interface are also designed. For the precise mechanism, based on the analysis of existing pressure mode, the pressure devise with the pneumatic pressure and dynamic pressure of the compression spring is designed. For the transmission system, servo motor, servo driver and controller logic programming (PLC) were used to control the position and speed. Experiments show that the control system is fast, stable, and with good flexibility; pressure institutions could provide a stable pressure and have good mobility, the transmission system can provide a good position and speed control.In order to obtain good welding quality, to meet the requirements of different materials and processes, and to increase flexibility of supply, welding current control will be divided into several stages, using current waveform control method. The results show that the waveform of the power can be set flexibly, parameters, as current and time can be controlled accurately, meeting the needs of precision welding.After the installation of power and mechanical equipment, debugging and technology tests were applied. The results show that the welding power supply could meet the demand of high-quality welding, so it is an ideal precision seam welding power supply, and can be used for OSC, precision metal shell packaging and precision devices seam welding.