The structure of the connector:
Waterproof connectors to achieve the effect of waterproof and dustproof can generally be divided into the overall seal and single-hole seal.
The use of sealing material can be:
1.re"> Rubber seal plug
2.re"> Plastic injection seal
The former is more common with articulated body connector. The connector is more convenient to avoid with the locking mechanism so that between the line or line and the electrical connection between the pieces are more firm to prevent loosening. Generally used in the engine, the rain scraping the motor and other bumpy vibration environment; with pressure wire cover connector can ensure that the connector inserted into the terminal tail crimp wire is not in the root of the connector when the unnecessary shaking occurs, to reduce the vibration of the connector on the wire of the shear force, improve the quality of the wiring harness;
The principle of selection of connectors
1.re"> According to the electrical parts of the connector and its environment to choose a reasonable connector.
For the engine compartment, the bottom of the chassis and other external contact with the outside world of the line and the line, or line with the electrical components docking connector, should choose the rubber seal plug with the connector, the best form of single-hole sealed to facilitate easy maintenance of future disassembly.
2.re"> According to the location of the connector and a reasonable way to choose a fixed connector structure.
In the selection of the docking connector of the wiring harness and the wiring harness, it is better to select the connector with the hooking mechanism (attachment clip) and fix it to the sheet metal or the interior trim of the vehicle body nearby.
3.re"> Door harness and body wiring harness docking.
This is the best choice with a locking mechanism of the connector to ensure that the door in the frequent opening and closing, to avoid the phenomenon of docking loosening. The gland body connectors are commonly used in vehicles for the body vibration.
4.re"> In the selection of the color of the connector
For the same type of the connector, especially where the docking connector and docking position are the same, different colors of connectors should be chosen in order to be distinguished easily. Additionally, based on the overall coordination of the appearance of the car, the engine compartment sheath is preferred black or dark jacket.
5.re"> The engine closer to the connector should be selected according to the high temperature nylon connector.
Terminal selection, the role of the terminal:
To maintain a good state of conduction.
Terminal selection principle
To ensure that the terminal and the selected connector reasonably match; for the crimp wire diameter selection of the appropriate terminal; for single-hole rubber sealing plug connector, to select the tail to crimp rubber seal plug the terminal; terminal to select the contact resistance is very small dual spring-type structure.
Relay box and fuse box selection principles
In line with the functional requirements and reliability of the premise, the choice of existing mature products.
The size should not exceed the space given by the general layout, the size of the installation conditions to meet the pursuit of miniaturization.
The relay box of the engine compartment requires that the number of relays to be used in the engine compartment includes relay.
Dashboard Fuse Box Requirements include relays other than the engine compartment, such as:
1.re"> Small relay
2.re"> Post defrost relay
3.re"> Air conditioning relay
4.re"> Wiper relay
5.re"> Fuel pump relay
6.re"> Over travel relay
7.re"> Blower relay
Currently, the most used and the most common sheath is the PA, PBT, PP, ABS and so on.
1.re"> PA: white, good toughness, abrasion resistance, odorless, drilling, cutting, planning, injection molding, good creep resistance (KB600), moisture absorption, heat resistance 105 °C.
It has high mechanical strength, high softening point, heat resistance, low coefficient of friction, abrasion resistance, self-lubricating, shock absorbing and silencing, oil resistance, weak acid resistance, alkali resistance and general solvent, good electrical insulation, self-extinguishing, non-toxic, odorless, good weather resistance, poor dyeing. Drawback is the large absorbent, affecting the dimensional stability and electrical properties, fiber reinforced resin can reduce the water absorption, so that it can work in high temperature and humidity. Nylon and glass fiber affinity is very good.
2.re"> PBT is one of the toughest engineering thermoplastic materials, it is semi-crystalline and has a very good chemical stability, mechanical strength, electrical insulation properties and thermal stability. These materials have a very good stability under a wide range of environmental conditions. They also have excellent chemical and electrical properties, size stability, good plasticity, creep resistance (KB250) and heat resistance 120 °C.
The fact that the crystallization speed of PBT is very high, its viscosity is very low and the cycle time of plastic parts processing is generally low. Chemical stability at room temperature it is not weak acid weak base, water, organic solvents. It is very stable at high temperatures as well. PBT moisture absorption is very weak and high temperature does not absorb water.
We can see some of the most used materials in the automotive wiring harness on the control line or almost most of the PBT materials, such as:
•re"> Fuse boxes
•re"> Fuel injectors
•re"> Idling motors
•re"> Air flow meter used in the PBT connector
3.re"> PP is light weight, cheaper, wear resistant, has good engineering performance, no water, used for small and ultra-small coaxial connector, heat 90 °C.
It is also non-toxic, tasteless milky white high-crystalline polymers and has the lowest density in all synthetic resins. PP also has a high rigidity, low relative density, high tensile strength, good transparency, resistance to stress cracking, chemical resistance and relatively high heat distortion temperature. Good injection molding processability and water stability. A very important feature is the outstanding bending fatigue strength.
4.re"> ABS appeared 40 years ago in a thermoplastic engineering plastics, styrene polymer system has become the fastest growing class of polymers. Because ABS is a terpolymer, it contains three components of the common performance and can adapt to various fields in a wide range of application requirements. ABS opaque, non-toxic, tasteless, both tough, hard, just and other characteristics, burning slowly, from the fire continues to burn, the flame was yellow, black smoke, burning plastic softening, charred, issued a special cinnamon odor but no melt dripping.
ABS has good mechanical properties, heat, and chemical resistance, easy processing, cheaper than nylon, creep resistance (KB300, heat resistance of 60 ° C. It has a high impact resistance and excellent work environment tolerance. ABS is suitable for use at low temperatures (-40 ° C).
Due to its thermal insulation properties, ABS requires little or no additional insulation. Therefore, ABS is used in the cold environment, the ideal material, it has good moldability. It can be plated and colored.
1.re"> Poor weather resistance
2.re"> Poor UV resistance intensity