The processes of motor terminal are as follow: ?Clean the weld surface with cold water. After accurate assembly, send it between the upper and lower electrodes and apply pressure. ?Contact fully. ?After power on, the contact surfaces of the two artifacts are heated and partially melted to form melting cores. After cutting off the power supply, maintain high pressure, and cool and solidify the melting core under pressure to form welding points. Remove the pressure and take out the artifact. Spot welding process parameters such as welding current, electrode pressure, power time and electrode surface size will affect the welding quality.

The motor terminal welder uses high-temperature arc generated by the short circuit of positive and negative polarity to melt the welded objects between the electrodes, so as to connect them. The structure of the spot welder is very simple. To put it bluntly, it is a high-power transformer that turns 220V AC into a low-voltage and high-current power supply, which can be DC or AC. Electric welding transformer has its own characteristics, that is, its voltage drops sharply.

After welding the electrode, the voltage of motor terminal decreases and the operating voltage of the welding machine is adjusted. Except for the primary 220/380 voltage conversion, the secondary coil has taps to change the voltage, and a soldering core is provided to adjust the adjustable iron core. According to the inductance principle, welding machine generally adopts high-power transformer. In the switching state, the inductance will produce a large voltage change. In case of instantaneous short circuit, the positive and negative electrodes produce high-voltage arcs to melt the solder on the electrode. The purpose is to combine them.

Spot welding is a kind of resistance welding method, which is formed by assembling the joint of welding parts and melting the base metal between two electrodes with resistance heat. Spot welding is mainly used for the connection of thin plates, such as aircraft skin, aero-engine fire pipe, automobile cab cover, etc. Spot welding machine transformer is spot welding electrical equipment, and its secondary coil is only one ring. The upper and lower electrodes and electrode arms are used to conduct welding current and transmit power supply at the same time. When the cold water line passes through the transformer, electrode and other parts to avoid welding heating, the cooling water shall be connected first, and then the power supply shall be connected. Its quality directly affects the welding process, welding quality and production efficiency. The welding rod generally uses red copper, cadmium bronze, chromium bronze, etc; the shape of the electrode is different, mainly depending on the solder shape. Install the electrodes, make sure the upper and lower electrode surfaces are parallel, keep the electrode surface clean, and often trim it with sand cloth or file. There are four basic steps for welding cycle spot welding and projection welding process:

(1) Preloading stage - the electrode drops to the current phase to ensure that the electrode has appropriate pressure values between the pressure devices.

(2) Welding time - welding current passes through the artifact to produce hot melt.

(3) Hold time - cut off the welding current and continue to apply pressure to the electrode until the melting core solidifies to sufficient strength.

(4) Time out - the electrode starts to rise, the electrode starts to fall again, and the next welding cycle begins.

In order to improve the performance of welded joints, sometimes one or more of the following elements must be added to a basic cycle:

(1) Increase preloading, eliminate the gap between thickeners and make them closely fit.

(2) The metal plasticity is enhanced by preheating pulse, so that the utensils are easier to fit tightly and prevent splashing. In this way, multiple convex points can be used to evenly contact with the plate before welding, so as to ensure the consistent heating of each point.