Classification of automotive terminal welding

Automotive terminal welding can be divided into: WUK terminal, European terminal series, plug and pull terminal series, transformer terminal, building wiring terminal, fence terminal series, spring terminal series, track terminal series, through the wall terminal series, Photoelectric coupling terminal series, 110 terminal, 205 terminal, 250 terminal, 187 terminal, OD2.2 ring terminal, 2.5 ring terminal, 3.2 ring terminal, 4.2 ring terminal, 2 ring terminal, 6.4 ring terminal, 8.4 ring terminal, 11 ring terminal, 13 ring terminal flag series terminals and sheath series, all kinds of rings U-terminal, tubular terminal, wiring terminal, copper strip iron strip (2-03, 4-03, 4-04, 6-03, 6-04), etc. At present, PCB board terminals, hardware terminals, nut terminals, spring terminals are commonly used.

The plastic insulation materials and conductive parts of the welding terminals of the automobile are directly related to the quality of the terminals, which respectively determine the insulation properties and conductive properties of the terminals. The failure of any terminal will lead to the failure of the entire system project. There is no need to say much in this regard, there are many warning cases, and Xiaobian will not list them one by one. As a fine operation of the accessory products, the quality of the motion control terminal has been the attention of customers, how to effectively check and prevention has become a topic of concern.

Wiring car terminal welding common problems

From the application point of view, the function that should be reached is: the central part of the contact part must be connected and the contact is firm. The central part of the insulation that should not be conductive must be securely insulated. There are three common fatal faults in terminal terminals:

1, the problem of poor contact

The metal conductor inside the terminal is the central part of the terminal, which transmits the voltage, current or signal from the external wire or cable to the corresponding contact with its matching adapter. Therefore, the contact parts must have the structure, stable and reliable contact persistence and good electrical conductivity. Due to unreasonable structural design of contact parts, incorrect selection of materials, unstable mold, poor processing size, rough appearance, unreasonable external disposal process such as hot disposal electroplating, improper assembly, poor storage and use environment and improper operation, poor contact will be formed in the contact parts and matching parts.

2, the problem of poor insulation

The function of the insulator is to make the contacts adhere to the correct position arrangement, and to insulate each other between the contacts and the contacts, and between the contacts and the shell. Therefore, insulation parts must have electrical properties, mechanical properties and process forming properties. Especially with the widespread use of high-density and miniaturized terminal blocks, the effective wall thickness of insulators is getting thinner and thinner. This puts forward more stringent requirements for insulation materials, injection mold accuracy and molding processes. Due to the existence of metal residues on the surface or inside the insulator, external dust, flux and other pollution by moisture, organic data precipitates and harmful gas adsorption film and external water film blend to form an ionic conductive channel, moisture absorption, mildew, insulation data aging and other reasons, will form short circuit, leakage, breakdown, low insulation resistance poor insulation phenomenon.

3, the problem of poor fixation

The insulator not only insulates, but also usually provides accurate neutralization and maintenance for the extended contact, and also has the function of positioning the device and locking it on the equipment. Poor fixation, light affect the contact of the formation of instant power failure, serious is the product collapse. Breakdown refers to the terminal in the plug state, due to data, design, process and other reasons to cause the construction of the plug and socket, the abnormal separation between the pin and the jack, will form a serious result of the control system power transmission and signal control infix. Due to unreliable design, material selection errors, improper selection of molding process, poor process quality such as hot disposal, mold, assembly, welding, and assembly is not in place, poor fixation will be formed.

In addition, due to coating peeling, corrosion, damage, plastic shell flash, crack, rough processing of contact parts, deformation and other reasons formed by the appearance of poor, due to the positioning lock with the size of the excess, poor processing quality divergence, total separation force is too large and other reasons formed by poor exchange, is also common disease, frequently occurring. These problems can generally be found and eliminated in time in the process of inspection and use.

How to detect car terminal welding short circuit fault

Defects in wires and terminals may also be caused by a short circuit between the harness and the body (ground wire) or within the switch concerned. Before checking, we should first look at whether the terminal fixing of the body is reliable, and then we can stop the test according to the following steps.

1. Check whether the wire is connected

First remove the terminal on both sides of the control computer ECU and sensor, and then measure the resistance between the corresponding terminals of the terminal. If the resistance value is not greater than 1 ohms, it is stated that the wire is normal, so as to stop the next check. When measuring the resistance of the wire, quietly shake the wire in both vertical and degree directions to improve the measurement, and note that for most wire terminals, the meter bar should be inserted from the back end of the adapter, but the waterproof terminal bar equipped with a waterproof sleeve can not be inserted from the back end, because the terminal will be deformed if you are not careful when inserting.

2. Check the resistance value of short circuit

First, remove the wire terminals on both sides of the control computer ECU and sensor, and then measure the resistance value between each terminal block of the connector on both sides and the body. When measuring, one end of the meter rod is connected to the body with an iron, and the other end should stop measuring on the wire adapters on both sides respectively. If the resistance value is greater than 1 ohms, it is stated that the wire and the body have no short circuit fault.

3, automobile terminal welding appearance and contact pressure inspection

First of all, remove each terminal one by one, check whether there is rust contact and dirt on the connector terminal, and the rust and dirt should be cleared. Then check whether the terminal piece is loose or damaged, whether the terminal is fixed reliably, and the terminal should not be loose when quietly pulled. On the contrary, if the plug terminal in one seat hole is easier to pull out than the other seat holes, the seat hole may cause poor contact problems in use.