Projection Welding Machine

Projection welding is used for welding several projections on the workpiece which can be round dimples, circular, rib type, extended corners, or elongated ridges of weld nuts. Projection welding is a type of resistance welding which utilises pressure and electrical current to link two metal parts or sheets which have been designed to meet at one or more precise points with the maximum amount of contact. This permits for more effective welding with a lesser amount of energy and better weld strength. Projection weld not only joins two pieces of metal together, but also can threaded stud, weld a nut, or projection to an assembly. It is a variation of spot welding

Projection welding machines apply the current and weld forces on determined weld points. These projection welding machines are capable of executing the heaviest mass production joining functions.

The working principle of projection welding is welding by applying greater external pressure between two metal sheets or workpieces with the help of small metal projections between them. The projections when external pressure is applied and sufficient current passed through them, gets heated and welded together to form sturdy welding joints.

1. The two metal workpieces to be linked or welded are positioned between the two copper electrodes which are kept upwards & downwards.
2. A large amount of External Pressure (force) is applied to the electrodes which ultimately gets transferred to the workpieces. 
3. Afterwards, the current is passed through the electrodes which generates heat because of the internal resistance of the metal workpieces.
4. The heat created due to resistance is concentrated at the projections on the workpiece as the two workpieces are positioned in a way that the metal sheets come in touch only at the projection points. 
5. These two workpieces then get welded in one shot.
6. Due to the pressure applied on the workpiece, the projections break and get fused forming weld nuggets at the projection spots. 
7. Lastly, a quality projection weld is created between two metal workpieces welding them permanently.
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Advantages of Projection Welding Machine:

• Closer Welds: Permits closer spaced welds.
• Ease of Use: Highly automated machineries and several welds can be handled at one time.
• Extended Lifetime: Have a longer life expectancy than spot welds, as it needs less heat and pressure throughout the welding process.
• Versatility: Easy to fine-tune to different parameters, thus can be used for a wide range of parts and components.
• Clean Finish: Allows for compact surface inadequacies at the welded joint and results in a smoother finish.
• Increased Production: The method permits for more than one weld to be accomplished at one time, thus increasing production output.

Applications of Projection Welding Machine:

Mechanical: manufacturing of mechanical machineries and for joining crossed wires and bars. 

Automotive: used to weld connectors such as screws, nuts, and bolts to flat sheets.

Consumer goods: manufacturing of consumer goods such as furniture, fans and fan covers, and household appliances.

Semiconductors: hermetically sealing of semiconductor equipment to avoid the intrusion of air and other gases that could harm its operational capacity.