Composition of welding equipment
Welding equipment includes welding energy equipment, welding head and welding control system.
1 welding energy equipment
It is used to provide the energy required for welding. Commonly used are all kinds of arc welding power source, also known as electric welding machine. Its no-load voltage is 60~100 volts, the working voltage is 25~45 volts, and the output current is 50~1000 Ann.
The arc length often changes during manual arc welding, resulting in the change of welding voltage. In order to make the welding current unstable, the external characteristic of the arc welding power source should be steeped, that is, the output current should be changed very little with the change of output voltage.
A flat characteristic power supply can be used for gas metal arc welding and submerged arc welding. Its output voltage changes very little when the current changes.
There are usually arc welding transformers, DC arc welding generators and arc welding rectifiers. Arc welding transformer provides alternating current and wide application. DC arc welding generator provides direct current, which is more complex, consumes more materials and has lower efficiency, and it is gradually replaced by arc welding rectifier.
Arc welding rectifier is a DC arc welding power source developed in 1950s, using silicon diode or silicon controlled rectifier as rectifier. The transistor type arc welding power source, which was made up of high-power transistors in 60s, can get higher control accuracy and excellent function, but the cost is higher.
The resistance welding transformer is more simple than the resistance welding transformer. The no-load voltage range is 1~36 volts, and the current is from thousands to tens of thousands of safety. The welding machine equipped with this welding energy equipment is called AC resistance welding machine. Others are low frequency resistance welding machine, DC pulse resistance welding machine, capacitor energy storage resistance welding machine and secondary rectifier resistance welding machine.
2 welding machine head
Its function is to transform the energy output from the welding energy equipment into the welding heat, not to bury the welding material, and the machine head moves forward to realize the welding. The electric welding clamp used for manual arc welding will be sent downward to the welding rod manually and melt along with the melting of the welding rod. The automatic welding machine has an automatic feeding wire mechanism and a head moving mechanism to move the head forward. There are two commonly used car type and hanger type head. The welding head of resistance spot welding and projection welding is an electrode and its pressurizing mechanism, which are used to exert pressure and electricity on the workpiece. The seam is welded with a transfer mechanism to drive the workpiece to move. Butt welding requires static, dynamic clamping and clamping mechanisms, as well as mobile fixture welding equipment and forging mechanism.
3 welding control system
Its function is to control the whole welding process, including controlling welding procedure and welding specification parameters. The general AC arc welder has no control system. High efficiency or precision welding machines are controlled by electronic circuits, digital circuits and microprocessors.