Mechanical Knowledge Base: "Resistance Welder"

Definition : A welder that uses electric current to generate heat through the resistance between the workpiece and the welding contact surface, and at the same time pressurizes the welding place for welding. Including spot welding machine, projection welding machine, seam welding machine, resistance welding machine, flash butt welding machine, capacitor energy storage ignition welding machine, high frequency resistance welding machine and so on.

A resistance welding machine compresses a workpiece to be welded between two electrodes and applies an electric current to heat the molten workpiece to a molten or plastic state by using a resistance heating effect caused by current flowing through the contact surface of the workpiece and the adjacent region. A method of forming a metal bond.

Resistance welding machine welding methods are mainly spot welding, seam welding, projection welding, butt welding,

First, spot welding

Spot welding is to assemble the weldment as a lap joint and press it between the two columnar electrodes and use the resistance heat to melt the base metal to form a resistance welding method for the welding spot. Spot welding is mainly used for thin plate welding.

Spot welding process:

1, pre-pressure, ensure good contact with the workpiece.

2, electricity, so that the formation of welding nugget and plastic ring.

3, power off forging, so that the nugget cooling and crystallization under the pressure continue to form a dense, non-shrinkage, crack solder joints.

Second, seam welding

The process of seam welding is similar to that of spot welding, except that instead of a cylindrical electrode, a rotating disk-shaped roller electrode is used to assemble the weldment into a lap joint or a butt joint and placed between two roller electrodes, and the roller presses the weldment and rotates. Continuous or intermittent power transmission to form a continuous weld seam resistance welding method.

Seam welding is mainly used to weld a relatively regular weld structure that requires sealing, and the plate thickness is generally less than 3mm.

Third, welding

Butt welding is a resistance welding method that welds the weldment along the entire contact surface.