Pin Socket Manufacturers Analyze the Causes of Electrical Contact Failure of Automotive Connectors

Release time:

2024-01-12 17:16

Connector Pin JackUsed in many fields, such as automotive connectors, do not look at the pin jack is a small component, it plays a key role in conduction and signal. What are the causes of electrical contact failure that affect automotive connectors?

(1) lack of electrical contact pressure.

The automobile connector is conductive through the contact between the pin and the socket. The socket is an elastic element. Its quality is very important to the reliability of the electrical connection. The pin is inserted into the socket to produce elastic deformation, which in turn produces contact pressure on the pin. The instability or reduction of the contact pressure will affect the instability of the contact resistance. Under the action of certain vibration and impact stress, the elastic element will produce restorative elastic deformation, vibration, impact stress satisfaction, long time satisfaction, will form a transient fault. The pin socket is subjected to the acting force and reaction force for a long time, and the elastic element of the socket gradually produces permanent deformation, resulting in stress fatigue relaxation. Especially under the action of the contact point and the ambient temperature, the socket will creep, the contact pressure will decrease, and the contact resistance will increase.

(2) contact wear.

Insertion and removal wear: When the car connector is inserted and separated, the pin and the socket will conflict due to relative movement under a certain contact pressure. During the conflict process, the smoothness of the contact surface will be damaged and the geometry will be changed., Scratches, adhesion, wear debris, material handling, etc., are also generated with heat. With the increase of the number of plugs and unplugs, the surface coating metal of the pin socket is worn out, revealing the base metal, causing corrosion under the action of the surrounding environment, forming poor contact. The degree of surface wear of the contact pair is related to the details of the contact pressure, the surface finish of the contact conflict part, the type, hardness and quality of the surface coating of the contact pair, whether the fillet of the contact guide part is lubricated, and the geometry of the socket contact part. When the contact pressure is high, the pin head and the inner hole of the socket have poor connection, the roughness of the contact part is high, the hardness of the coating material is low, and the coating quality is poor, the contact wear is more serious. The plug life of the connector is also low, and the contact stability is also poor.

Fretting wear: Fretting vibration is a wear phenomenon that occurs on two surfaces that move relative to each other with a small amount of vibration. Its amplitude is 1-100um. It is mainly caused by thermal expansion and contraction caused by temperature cycles and vibration of the scenery. Because of its working conditions, vibration and thermal shock exist together, so fretting is frequently generated. For example, the automobile connector fluctuates according to 5 ℃/h, cycles 20 times, the thermal expansion coefficient of the pin (made of brass) is 2x10-5/℃, and the pin length is 5mm, the micro amplitude can reach 5um. Experiments show that this micro-vibration up to millions of times, it may seriously affect the reliability of electrical contact. For example, when a car runs for 5h, the vibration frequency is 1000Hz, which is equivalent to 18 million times of micro-vibration.