From the perspective of application, the function of the terminal block should be achieved: the contact part should be conducted, and the contact should be reliable. The insulating parts should not be conducted, and it is necessary to insulate them firmly. There are three common forms of fatal failure of terminal blocks:
1. Poor contact
The metal conductor inside the terminal block is the central part of the terminal, which transmits the voltage, current, or signal from the external wire or cable to the touch piece corresponding to the connector it is mated to. Therefore, it is necessary for the touch parts to have excellent structure, stable and reliable touch persistence and outstanding conductive function. Because the structural planning of the touch parts is unreasonable, the data selection is wrong, the mold is unstable, the processing size is out of tolerance, the appearance is rough, the surface treatment process such as heat treatment and electroplating is unreasonable, the assembly is improper, the storage and application environment is poor and the operation is not appropriate, it will form a poor touch in the touch part and the cooperation part of the touch part.
2. Poor insulation
The effect of the insulator is to make the touching piece adhere to the correct orientation arrangement, and to insulate the touch piece from the touch piece, and between the touch piece and the shell. Therefore, it is necessary for the insulator to have excellent electrical function, mechanical function and process forming function. In particular, 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 process. Because of the presence of metal excess on the surface or inside of the insulator, the pollution of dust, flux and other pollutants on the surface, the precipitation of organic data and harmful gas adsorption film and the surface water film blend to form an ionic conductive channel, moisture absorption, mildew, aging of insulation materials, etc., will form short circuit, leakage, breakdown, insulation resistance of a lower level of insulation poor insulation phenomenon.
3. Poor fixation
The insulator not only plays an insulating effect, but also generally provides the best alignment and protection for the outstretched touch piece, and also has the function of device positioning and locking and fixing on the equipment. Poor fixation, light affect the touch firmly to form an instant power failure, the severe is the product collapse. Collapse refers to the abnormal separation between the plug and the socket, and between the pin and the jack due to the unreliable structure of the terminal in the mating state, due to data, planning, process and other reasons, which will form the severe consequences of the interruption of power transmission and signal control of the control system. Because the planning is not reliable, the selection of materials is wrong, the molding process is not properly selected, the heat treatment, mold, installation, welding and other processes are of poor quality, and the installation is not in place.
In addition, the poor appearance caused by the peeling, corrosion, bruises, flash of the molded shell, cracking, rough processing and deformation of the touch parts, etc., and the poor exchange formed by the positioning and locking cooperation size, poor processing quality consistency, and excessive total separation force are also common and frequent diseases. These kinds of defects can generally be found and eliminated in time during inspection and application.
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