The car is mainly composed of power system, transmission system, driving system, steering system, brake system, electrical system, etc. The pipeline of the whole vehicle refers to the wiring harness, hose, hard pipe, cable and other tube-like parts in each functional system. The role of pipeline parts is to transfer electrical signals, force, oil and gas and other media between the functional parts to ensure that each system achieves the corresponding function, so that the whole car can run safely and smoothly. The pipeline of the whole vehicle is like the blood vessels and neural network system of the human body.

The wiring harness system is an important part of the pipeline system of the whole car. When the car is running, in addition to engine vibration, it will also be affected by various complex limit road conditions, and its movement amplitude is not consistent due to the different characteristics of the pipeline connected within and between each system. If the wiring harness and other pipeline design arrangement is not reasonable, parts manufacturing and assembly quality problems, with the movement of the whole car, the risk of dynamic interference between pipelines, and even wear, causing major safety problems. Take the wiring harness as an example, if there is dynamic interference with the surrounding sharp-edged parts, it is easy to be worn out and cause short-circuit fire, functional failure and other problems, resulting in safety accidents. Through the analysis of nearly 900 cases of vehicle recalls at home and abroad in 2004, we found that there were as many as 135 cases of after-sales recalls caused by piping problems, accounting for 16.2% of the total. Most manufacturers, including GM, Honda, Toyota and BMW, were not spared. Thus, it is clear that the study of how to control the piping quality of the whole vehicle has important strategic value and significance for automobile manufacturers.

The basic composition of the whole vehicle wiring harness piping system

According to the functional characteristics of the parts, the whole vehicle piping system is mainly divided into three major parts, as shown in Figure 1.

(1) Wiring harness system The wiring harness system is mainly responsible for the transmission of electrical energy and electronic signals of the whole vehicle. As shown in Figure 2, according to different functional areas, the wiring harness system is divided into: ① headlight wiring harness assembly; ② engine wiring harness assembly; ③ main body wiring harness assembly; ④ instrumentation wiring harness assembly; ⑤ door wiring harness assembly; ⑥ front and rear reversing radar wiring harness assembly, etc. 2) Lasso system mainly includes front cover locking lasso, shift lasso, clutch lasso, throttle lasso, parking brake lasso and refueling small door lasso, etc. 3) Other soft and hard Mainly includes air conditioning system piping, HVAC piping, cooling system piping, automatic transmission oil cooling piping, intercooler inlet and outlet piping, washing system piping, intake and exhaust piping, fuel piping, brake oil piping, brake vacuum piping, clutch oil piping, etc.