The automobile harness terminal provides the integration of maintenance equipment for a particular load group, such as transmitting line, exchanger, control system, etc. The basic research content of telephone service theory is to study the relationship between telephone traffic, call loss and harness capacity. Therefore, automobile harness terminal is an important basis in telephone service theory. This article focuses on the definition, composition, material and material selection of automobile harness terminal.

1. Definition of automotive harness terminal

A communication bridge is built between two or more isolated electronic circuits, so that the current can flow and the functions of various electronic components can be used. It is an indispensable component in all kinds of electronic equipment.

2. Composition

Signal line: It needs to be injected and formed.

General wiring harness assembly includes: wire, terminal and plastic parts.

The composition of the composite wire harness also needs to be attached to tape, tape, ribbon, sleeve, sheath, label, etc.

3. Material

Take the material requirements for automotive harness terminal as an example: including its electrical properties, material scattering, heat-resistant etc. Because the automobile harness terminal is vital to human safety, and the material safety requirements are much stricter than that of ordinary wire harness. The following 6 points are the requirements for harness materials of automobile harness terminals:
1> The weak signal sensor shall adopt shielded conductor.

2> Anti-hydraulic oil is used for the wires on the automatic transmission; heat-resistant; with good temperature stability.
3> The harness wire on the luggage compartment lid should remain elastic at low temperature, so cold elastic wire should be selected to ensure its normal operation.
4> Heat-resistant 150-200℃ used in the ABS harness assembly; external protection of insulation layer; wear-resisting. However, the wire core shall be greater than 133 strands.

5> The wires used for power lines such as starter generator output line and battery line are special wires that can bear high current and have good heat dissipation capacity of insulation layer.
6> The temperature around the internal combustion engine is high and there are a lot of corrosive gases and liquids. Therefore, the harness wire of the internal combustion engine must be high temperature resistant, oil proof, vibration resistance and Friction resistant.

4. Selection

The quality of the beam material directly affects the quality of the harness, and the selection of the harness material is crucial to the quality and service life of the harness. Therefore, we must not be greedy for the cheap one in the selection of harness products. Cheap harness products may use inferior harness materials.

So how can we know whether the quality of the harness is good or bad, and how can we have some knowledge of automotive harness terminal material.

The following four points are the data of harness material selection, which is generally composed of conductors, insulating sheath, terminal block and wrapping material. As long as you know these materials, you can easily distinguish the quality of harness.

1> Selection of harness conductor materials: select corresponding conductor materials according to the operating environment.
2> Selection of insulation and sheath materials: the sheath material (plastic products) is generally PA6, PA66, ABS, PBT, PP etc. Flame retardant or reinforcing materials can be added to plastics according to the actual situation to achieve the purpose of strengthening or flame retardant, such as adding glass fiber reinforcement.
3> Selection of automobile harness terminal materials: the copper used for wiring materials (copper parts) is mainly brass and bronze (the hardness of brass is slightly lower than that of bronze), in which brass accounts for a large proportion. In addition, different coatings can be selected according to needs.
4> Choice of wrapping material: the function of wire covering is wear-resistant, inflaming retarding, anti-corrosion, shielded from interference, reduce noise， and beautify the appearance. Wrapping materials are generally selected according to the working environment and space size. Tape, bellows, PVC pipe, etc. are generally used as wrapping materials.