Principle of harness construction and key control points

The classification and function of harness

1. wiring harness introduction
Wire harness, English for Wire Harness, in Chinese translated into assembly wire and device with wires, that is, wiring harness, specifically refers to the car, motorcycle and a variety of household appliances, computers, vending machines and other internal electrical wiring.

The automobile harness is the central nervous system of the automobile. It is the carrier of automobile energy and various signal transmission. It connects the central control part with the automobile control unit, the electrical and electronic execution unit, the electrical and the lighting display organically to form a complete Automotive electrical control system. It is mainly composed of wires, connectors, fasteners, rubber parts and insulation, shielding casing and other parts.

The distribution of the car harness in the car is shown below.

2. Classification and function of automobile wiring harness

The type of wiring harness is based on the location and shape of the wiring to distinguish, where we introduce the various parts of the car wiring harness, mainly the use of SVW (Shanghai Volkswagen) name.

2.1 battery cable

A, battery (+) pole line

Battery (+) ~ between the generator wiring, commonly known as Battery (battery) / Starter (starter) Cable.

As the starting circuit of the car, the need for high-current circulation, so the use of the wire is the most rough car (8m ㎡ or more). If you touch the terminal directly, it will cause electric shock. Therefore, for the sake of safety, a rubber cover for insulation is installed.

B, battery (-) pole line

Battery (-) ~ between the body / engine wiring, commonly known as Earth Cable. The current from the battery (+) is returned to the battery (-) by wiring between the battery (-) to the vehicle body / engine.

2.2 Inside the engine wiring

Generally referred to as engine engine W / H and body side Front W / H. The reason for its separation is because the engine is equipped with the engine at the end of the car loading.

The engine room wiring environment and conditions are quite poor. So with the indoor wiring harness is different, it also needs a lot of time in the environmental countermeasures. In order to waterproof, in the plastic shell for waterproof bandage and filling lubricants, some molded case to join the waterproof bolt, or blind plug waterproof. Use heat-resistant wires / hoses at high temperature. In addition, a protective hose is used in the vicinity of a vibration and a rotating part, and a large number of hooks are used for wiring in a narrow place such as a brake and a fuel piping.

In addition, the harness once loaded, in addition to a special repair staff is no one can see, but only the engine room wiring harness is different, as long as the engine cover can be opened to see. Therefore, in order not to let people see the harness after the uneasy feeling, the exterior parts are also unified into black (because the color of the wire is not only black, so use black tape wrapped, and then put on the hose).

The main car circuit is the headlamps, turning lights and other lighting systems and tail light line (from the driver's seat to the rear of a harness, the electrical device is mainly the door system and taillights and other lighting systems, the loop is not much, but because the car The inside is not smooth, so when the wiring to be very careful, in order to try not to foot to the wiring harness, need to use the module Molded Case to rationalize the wiring).

2.4 indoor wiring (dashboard line, a variety of control lines, receiving line)

The Instrument W / H, which is typically arranged in the dashboard, is laid under the carpet, called Floor W / H. Instrument Panel: Instrument Panel To connect a lot of SW and Radio, Clock, Meter, etc., if the assembly will be quite time-consuming, so to separate it, assembled on the Vice Line. Because the installation space is small and quite complex, so the use of a small plastic shell, buckle / soundproof material, and the initial charging system, generator system.

In addition, if the wiring harness is too long, it will affect the laying of the carpet, as a bad reason.

2.5 other wiring (door wiring harness, roof wiring harness)

Door W / H: General 4 doors and Back Door together called Door W / H.

The difference from other harnesses is that it also requires the curvature of the harness, and sometimes the Taxi specification is to be tested for 100,000 cycles of durability (55 times / day). In addition, Door W / H is also arranged in the door / outside, so the same also waterproof waterproof performance.

Antenna: harness configured in a zenith lamp and sunroof.

Extension W / H: it is not necessary, but when loading for other equipment with the need to connect, in the standard harness on another section of the harness. In mass production because the cost is very expensive, so do not use this method, it is often used as a repair parts to set. (Mainly for audio parts)

In addition, according to different models, also configured ABS, automatic transmission, security, etc., more than 300 circuits.