Automotive wiring harnessThe planning content includes the electrical functions and electrical requirements to be completed by the harness, the scale, maintenance, fixing method of the harness, and the connection method between the harness and the automobile electrical appliance. So how is the car harness planned?

1、 Schematic diagram planning and accounting of automobile wiring harness

1. The electrical schematic diagram shall be prepared according to the electrical equipment and technical requirements required in the Electrical Planning Assignment.

2. Confirm the safe capacity and wire diameter according to the power of each electrical appliance, and distribute the load of each electrical subsystem together to confirm the total safe capacity.

3. Calculate the wire diameter: according to the formula:

I - current, A;
P - electrical material power, W;
U - voltage, V;
A - wire diameter, mm2;
ρ—— Copper resistivity (about 0.0185 Ω mm2/m);
L=conductor length, m;
U - maximum allowable voltage drop loss.

4. Conductors with different methods have different line voltage drop of allowable current.

2、 Make 3D wiring diagram

1. According to the different positions of various electrical equipment, confirm the 3D wiring method. Currently, the commonly used wiring methods in the world are generally E type and H type;

2. Simulate the wire harness diameter in different areas;

3. Consider the sealing and maintenance of harness vias.

4. Confirm the fixing hole position and fixing method of the harness.

5. Theoretically, it is the most reasonable to connect all electrical materials with one wire harness, but it is impossible to do so when actually loading the vehicle, so the wire harness should be reasonably divided into blocks, and systematic planning should be adopted as far as possible in the case of convenient assembly.

6. The grounding point planning is very important in the wiring harness planning, otherwise it will cause signal disturbance and affect the function completion of some electrical appliances; According to different vehicle types, multiple addresses are planned, and the grounding planning should meet the following points:

A. The weak signal sensor shall be grounded independently and nearby to ensure normal signal transmission;

B. Each ECU shall be grounded independently to avoid being disturbed;

C. The negative grounding of the battery and the grounding of the engine and transmission should be carefully considered.

3、 Plan 2D harness diagram

1. The distribution box (safety and relay) is the center of the whole vehicle's electrical system, which plays the role of distributing load, collecting power supply, saving space, simplifying wiring harness, reducing cost and facilitating maintenance. Generally, 1 to 2 can be planned according to the needs.

The power distribution box of some newly developed models already has the function of electronic control; And there will be more and more market for the central control box without contact and safe wire.

2. Selection of conductor color

3. Selection of connector

4. Binding method of automobile wire harness