Automotive wiring harness function introduction

Date:Jun 12, 2019

In modern cars, there are a lot of car wiring harnesses, and the electronic control system is closely related to the wire harness. Someone once used an image metaphor: If the functions of the microcomputer, the sensor and the actuator are compared to the human body, it can be said that the microcomputer is equivalent to the human brain, the sensor is equivalent to the sensory organ, and the actuator is equivalent to the moving organ, then the harness is the nerve and Blood vessels.

The automobile wiring harness is the main body of the automobile circuit, which connects the electrical and electronic components of the automobile and makes it function. Without the wiring harness, there is no automobile circuit. At present, the form of wire harness is basically the same whether it is a high-end luxury car or an economical ordinary car. It is composed of wires, connectors and wrapping tape. It must ensure the transmission of electrical signals and the connection of circuits. Reliability, supply specified current values to electrical and electronic components, prevent electromagnetic interference to surrounding circuits, and eliminate electrical short circuits.

The automotive wiring harness is functionally divided into a power line carrying electric power for driving an actuator (actuator) and a signal line for transmitting a sensor input command. The power line is a thick electric wire that carries a large current, and the signal line is a thin electric wire (optical fiber communication) that does not carry electric power; for example, the cross-sectional area of a wire for a signal circuit is 0.3, 0.5 mm2.

The cross-sectional area of the wire for the motor and the actuator is 0.85 and 1.25 mm2, and the cross-sectional area of the power supply circuit is 2, 3, and 5 mm2; and the special circuit (starter, alternator, engine grounding wire, etc.) has 8. 10, 15, 20mm2 different specifications. The larger the cross-sectional area of the wire, the larger the current capacity. The choice of wires, in addition to considering the electrical performance, is also subject to the physical properties of the vehicle, so the choice is very wide. For example, frequent on/off doors on a taxi and wires that span the body should be made up of wires with good flexing properties. Wires used in places where the temperature is high are generally made of vinyl chloride or polyethylene coated with good insulation and heat resistance. In recent years, electromagnetic shielding lines used in weak signal circuits have also increased.

With the increase of the functions of automobiles, the universal application of electronic control technology, more and more electrical components, more and more wires, the number of circuits and the amount of electricity used in automobiles have increased significantly, and the wire harness has become thicker and heavier. . This is a big problem that needs to be solved. How to make a large number of wire harnesses more efficiently and reasonably arranged in a limited car space, and make the car wire harness play a greater function has become a problem faced by the automobile manufacturing industry.

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