The spot welding head consists of two pieces of metal with good electrical conductivity. The two pieces of metal are insulated. There is only one contact at the high end. This contact forms a small resistance. The bottom end of the welding head is flat. Smooth. When operating the machine, when the welding head is pressed on the enameled wire by pneumatic means or with a foot, the pressure will increase continuously. When the reaction force of the enameled wire to the welding head reaches the set welding pressure, a trigger will be triggered. Pulse current, current time is very short, generally between a few milliseconds and ten milliseconds, the size is about tens to hundreds of times, the current flows from the bottom end of the welding head, there is a contact resistance at the high end of the welding head, Where the contact resistance is heated, an electric spark is generated. This heat removes the paint strip of the enameled wire and a large amount of heat is transferred to the copper wire inside the enameled wire. At the same time, a part of the current flows from the bottom end of the welding head through the burnt patent leather. The copper wire itself is also heated. The copper wire melts in a short period of time before the temperature reaches the melting point. Under the action of the pressure, a new nugget is formed with the underlying metal, so that the enameled wire is connected with the metal substrate.
