Lithium battery spot welding machine is mainly used in automobile manufacturing, computer chassis, power supply, microwave oven, electrical junction box, Faraday cage, and various electronic products. Spot welder is called spot welder because this contact produces high standard welding points. The welded material is not overheated, so the work is easy to handle. Weld height control, good coincidence. Here tell us the basic knowledge of spot welding machine, and then tell you how to use a microwave oven transformer to build a spot welding machine. The electrode of spot welding machine has at least three functions. They transmit electrical energy and hold it together, which also controls the resistance. The smaller the resistance, the less resistance heating. Increasing smaller resistance increases heat. The electrode also carries out heat source far away from the material, while breaking the cycle, helping to cool down and adjust the welding. Resistance spot welding is usually called "gold nugget". Spot welding machines are generally limited to non-ferrous metal materials, which limits their application to a certain extent. Most of them produce low voltage and high current welding. In the welding machine this method works in the second 3vac. Mainly 120 VAC line voltage, should be taken seriously. Low voltage secondary school makes welding very safe, so the risk of electric shock from the electrode is almost non-existent. However, the high temperature of any welding machine is at risk of burns. This special welding machine, it will not work material than sheet metal heavy. A small project for use because it cannot run continuously. Possible uses are as follows: electrolytic cells for welding electrode materials. In order to build a small machine platform, it has a light weight frame. Most of us have enough space for a spot welder. If you have a microwave oven transformer (MOT), you start.
The welding cycle of welding and bumping consists of four basic stages:
1. Pre-pressing stage - the electrode drops to the current connection stage to ensure that the electrode tightens the workpiece, so that there is appropriate pressure between the workpieces.
2. Welding time - Welding current passes through the workpiece and produces heat to form nuggets.
3. Maintenance time - Cut off the welding current and maintain the electrode pressure until the nugget solidifies to a sufficient strength.
4. Rest time - the electrodes begin to lift and the electrodes begin to drop again, starting the next welding cycle. In order to improve the performance of welded joints, it is sometimes necessary to add one or more of the following items to the basic cycle: 1) Increase the pre-pressure to eliminate the gap between thick workpieces and make them close to each other.
5。 Improving the plasticity of metal by preheating pulse makes the workpiece easy to fit tightly and prevent spattering; doing so during bump welding can make multiple bumps contact with the plate uniformly before electrified welding, so as to ensure the consistency of heating at all points。
6. Increase forging pressure to compact the melting core to prevent cracks or shrinkage.
7。 Eliminate quenching structure of alloy steel by tempering or slow cooling pulse, improve mechanical properties of joints, or prevent cracks and shrinkage without increasing forging pressure。
8. AC can make the current rise and fall slowly by adjusting the amplitude, so as to achieve the purpose of preheating and cooling slowly, which is very beneficial to the welding of aluminium alloy. AC can also be used in multi-pulse spot welding, i.e. to allow cooling time between two or more pulses to control heating speed. This method is mainly applied to the welding of thick steel plates.
9. DC is mainly used in situations where large current is needed. Because DC welding machines are mostly powered by three-phase power supply, the unbalanced three-phase load in single-phase power supply is avoided.
Weldability of metal resistance welding: The following are the main indexes for evaluating weldability of resistance welding:
10. Metals with low electrical conductivity and thermal conductivity and high thermal conductivity need high-power welding machines, which have poor weldability.