When using the CATIA module for harness data creation, the harness segment diameter is written into the software as an important parameter. All subsequent clearance checks and motion analyses are based on this value. Therefore, if there is a large difference with the actual one, it will lead to a situation where the original safety clearance requirement can be met, but when the actual vehicle is installed, it will be found to have interfered or even not assembled. Here we provide a theoretical calculation method for the estimation of the outer diameter of an automotive wire harness (standard algorithm for wire harnesses). A harness segment is a collection of all wires taped together with tape or other wrapping. Considering that the tape is wrapped around the harness only, and sleeve-type wraps such as bellows also need to determine the outside diameter of the harness before it can be selected. Therefore, for the calculation, we put the wrap part down first. In this case, the cross-sectional area of the harness section is equal to the sum of the cross-sectional areas of all the wires. Thus we have.
where S denotes the cross-sectional area of the wire harness segment and Si denotes the cross-sectional area of the i-th wire.
We default the cross section of the wire harness segment to a circle, and we have that
where D is the diameter of the wire harness segment and Pi is the circumference of the circle.
German standard wire compared to the Japanese standard wire insulation wall is thinner, with the increasing number of electrical parts of the vehicle, German standard wire is used more and more. Here we also choose the German standard wire for example to illustrate the relevant.
Table 1 German standard wire parameters table
It is worth mentioning that the commonly said 0.5 wire, 0.5 only refers to the cross-sectional area of all copper wires, and does not include the cross-sectional area of the insulation skin on the periphery of the wire. Therefore the maximum outside diameter is the parameter value we want for the calculation. Example: Through the definition of the relevant principles we already know that a harness has four 0.5 wire, three 1.5 wire, plus two 0.35 wire composition, the outer diameter of this section of the harness. Then we can find out through the formula 1: S = 2×3.1416x(1.4/2)2 +4×3.1416x(1.6/2)2 +3×3.1416x(2.4/2)2 =24.693 by the formula 2 D = 5.61) If this section of the line is defined by the use of tape flower wrap wrapping, tape thickness of 0.14, the diameter of the end of the harness at this time D = 5.6 + 0.14×2=5.88, an integer of 6mm. 2) If the line is defined as a tape wrap, the tape thickness is 0.14, the maximum diameter of the harness section is D=5.6+0.14x2x2=6.16mm, an integer of 6mm. 3) If the line is defined as a bellows wrap, a bellows with an inner diameter of 7mm can be selected based on the outside diameter of the harness section of 5.6mm, the The outer diameter of the bellows is 10mm, then the outer diameter of this harness segment is considered to be 10mm. harness data designers, can be suggested by the relevant with calculation formula Excel table, but also based on the actual work of experience or measurement, to establish a typical model of the relevant harness break each branch of the section of the outer diameter statistics, so that you can quickly and easily conduct the harness outer diameter estimation.
