1、 Introduction to automobile wire harness

1. The car harness is the main body of the car circuit network, connecting the blood vessels and nerves of the car electrical system. It is composed of wires, terminals, connectors, sheaths and other materials and plays the role of transmitting driving signals.

2. The system for manufacturing automobile wire harness can be roughly divided into two categories.

(1) Divided by European and American countries including China, the TS16949 system is used to control the manufacturing process.

(2) Based on cost: Toyota and Honda have their own systems to control the manufacturing process.

2、 Introduction to common materials of automobile wire harness:

1. Wire (low-voltage wire, 60-600V).

Wire type:

A. National standard line: QVR, QFR, QVVR, QBV, QBVV, etc.

B. Daily marking: AV, AVS, AVSS, AEX, AVX, CAVUS, EB, TW, SHE-G, etc.

C. German markings: FLRY-A, FLRY-B, etc.

D. American standard line: SXL, etc.

Common specifications include conductors with nominal cross-sectional areas of 0.5, 0.75, 1.0, 1.5, 2.0, 2.5, 4.0, 6.0 and other square millimeters.

2. Connector (rubber shell, usually made of plastic, and the conductor of pressure terminal is inserted into it to ensure the reliability of connection. Materials mainly include PA6, PA66, ABS, PBT, PP, etc.).

3. Terminal: a shaped hardware component, which is crimped on the wire to connect different wires to transmit signals. It is divided into male terminal, female terminal, ring terminal and circular terminal. The main materials are brass and bronze (the hardness of brass is slightly lower than that of bronze), of which brass accounts for a large proportion.

4. Seal (seal ring): an original, usually made of silica gel, and the groove and terminal of plastic parts are isolated from the external environment.

5. Blind plug (sealing plug): It is made of original rubber and plays the role of sealing and protecting the harness. Or it is a rubber piece, which is used to plug in the socket of the jacket, without inserting wires, to play the role of sealing.

When the car harness passes through the hole, the rubber parts are generally used for transition to play the role of wear-resisting, waterproof and sealing. It is mainly distributed at the interface between the engine and the cab, the interface between the front cabin and the cab (two on the left and two on the right), the interface between the four doors (or the rear door) and the compartment, and the inlet of the fuel tank.

6. Conduit: PVC sleeve, corrugated pipe, glass fiber pipe, etc. Used to protect the harness (classified according to different diameters).

7. Secondary locking piece (TPA): a plastic element, which is used to further fix the terminal connected with the wire on the connector to ensure the reliable connection between the terminal and the sheath. The secondary locking shall be installed in place, and the lock with sheath shall pay special attention to the directionality of some quality or process requirements.

8. Clip (clip): An original is usually made of plastic, which is used to fix the wire harness in the car. There are binding clip and bellows lock clip.

9. Tape: production tape, wrapped on the wire harness surface (divided into PVC, sponge tape, cloth tape, paper tape, etc.). Quality identification tape: red tape is used to identify product defects.

Tape plays the role of binding, abrasion resistance, insulation, flame retardance, noise reduction, marking, etc. It generally accounts for about 30% of the binding materials. Tape for wire harness is generally divided into three types: PVC tape, air flannelette tape and cloth base tape. PVC tape has better wear resistance and flame resistance. The temperature resistance is about 80 ° C, the noise reduction is not good, and the price is cheap. The material of flannelette tape and cloth base tape is PET. The flannelette tape has good binding property and noise reduction property, and the temperature resistance is about 105 ° C; The cloth base tape has good wear resistance, and the maximum temperature resistance is about 150 ° C. The common disadvantages of flannelette tape and cloth base tape are poor flame retardance and high price.