The Research On Welding Mechanism Of Automotive Starter Solenoid Switch And Welding Solutions

The automotive starter is composed of three parts-a DC motor, transmissionmechanism and electromagnetic switch. Electromagnetic switch is used for making andbreaking the circuit between the starter and the battery. It is the key component of theautomotive starter, and its performance has a direct impact on the reliability of the starter.Welding failure is the most serious fault of automotive starters.The main reason for the welding failure of the electromagnetic switch is the thermaleffect caused by arc. To explore the welding mechanism of the automotive starter,experiments are carried out in conditions of different voltage, current and load. Bycalculating arc duration of the contact in each making and breaking operation, weldingmechanism is finally researched and found out.In order to reduce the probability of welding failure, selection of contact materials is avery important factor. However, there not exists a rigorous and accurate calculation methodso far, we mostly rely on the experience to select materials. This project attempts to providea simple and feasible method to calculate the anti-welding ability of different materials.And compare different materials’anti-weldingability, then verified by experiments.To increase the probability of welding failure, we proposed a new tes t method-shortcircuit test method. Electrical endurance tests on several different materials are carried outin the short-circuit test conditions. By comparing the welding probability, failure rate andcontact erosion of different materials, it is concluded that experimental results coincide withtheoretical expectation.