Brief discussion on the principle of automobile harness layout

1. Consideration of installation convenience and assembly process feasibility

(1)Wire harness The plug-in shall be arranged at a position that can be touched by hand, or the plug-in can be touched after simply removing some body parts. For plug-ins that can only be plugged in and out with one hand, the plug-ins at the other end shall be fixed on the vehicle body.

(2) Consider Wire harness And the through-hole space of the plug-in, the sealing of the through-hole and the fixation of the plug-in, so as to meet the convenience and efficiency of threading and plug-in operation under actual conditions; For electrical equipment or switches with high maintenance rate, such as instruments, audio, air conditioning panels, etc., the back-end harness shall be reserved to the length of easy plugging.

(3) No plug-ins of the same model and color shall be arranged nearby, and each plug-in shall be distinguished to avoid misinsertion and damage during assembly Wire harness And electrical appliances.

2. Consideration Wire harness Fixing and protection of.

(1) According to Wire harness The fixed points shall be set reasonably according to the direction of the vehicle and the specific shape of the vehicle body. The distance between the two fixed points is generally no more than 300mm; A fixed point can be arranged at the obtuse angle inflection point; Two fixed points shall be arranged at the right angle inflection point; Avoid sharp corners and inflection points in the harness.

(2) According to the direction and size of the harness, reasonably select the fixing buckle and mark its position. In the installation direction of the fixed buckle, there must be enough space to facilitate the installation and removal of the buckle.

(3) With others Wire harness For the plug-in position connected with electrical equipment, fixed points shall be added at a suitable position not more than 120mm in front of the plug-in to reduce the vibration of terminals in the plug-in. Add fixed points at the branches of the main harness, and the distance between the fixed points and the fulcrum shall not exceed 100mm.

(4) To keep Wire harness Some positions need to use hard pipes or splints to ensure that the harness is not deformed. In order to ensure the directionality of the harness, snap with positioning shall be used at some positions.

(5) When there are many plug-ins, the fixed position shall be fully considered. If necessary, the harness slot and harness support shall be designed. The friction part between the harness leakage and the vehicle body shall be protected by bellows.

(6) Do not directly contact the sharp edges of the vehicle body, increase protection, prevent the sharp edges of the vehicle body from damaging the outer insulation layer of the harness, fix the plug-ins connected with vibration or moving parts, and avoid transmitting vibration on the harness.

3. Avoid interfering with surrounding parts.

(1)Wire harness The wiring harness shall be arranged along the edge and along the groove (wiring groove designed by the vehicle body) to avoid direct pressure on the harness. The gap with the pipe is uniform, and the gap with the surrounding parts is reasonable; For example, the seat should consider whether the clearance through the harness is sufficient and whether it rubs with other components.

(2) When installed on vibrating or moving parts, relevant measures shall be taken according to the actual situation Wire harness It must be of sufficient length. The reserved length is determined according to the vibration amplitude of the component and the maximum motion stroke of the moving component. Ensure that the reserved length will not transmit vibration on the harness and will not make the harness bear tension.

(3) The clearance with moving parts shall be determined as required, such as the clearance of wiper motor connecting rod, belt, fan, gear, cam, etc. Generally, it is required to be greater than 25mm, and whether the gear shifting mechanism is connected with Wire harness There is interference.

4. Avoid high temperature areas and pipes.

(1) Avoid Wire harness The layout is too close to the high temperature area. If this cannot be avoided, add a heat shield to protect the harness (at least 80mm). For the harness without heat shield, the spacing shall be at least 160mm, such as high-temperature components such as exhaust system, EGR and supercharging system and their related valves. However, the harness shall be at least 200mm away from the high temperature area of the exhaust muffler and at least 30mm away from the exhaust manifold.

(2) Do not use the same fixing points as the fuel pipe and brake pipe, and do not cross or contact the fuel pipe and brake pipe.

(3)Wire harness Other surrounding pipes, such as water pipes and vacuum pipes, shall be considered in the layout of the. Do not contact and interfere with these pipes.

5. Consider the via of harness layout.

(1) At the initial stage of design, the position and structural shape of the through hole and the relative position relationship between this position and other parts shall be considered.

(2) If the harness passes through the sheet metal hole from the cab to the outside, the external harness must be lower than the through hole to prevent the liquid on the harness from entering the room.

(3) When the four door harness is connected with the cockpit harness, the wire through hole on the door shall be lower than the wire through hole on the side wall of the vehicle body.

(4) The reliability of rubber parts on the harness must be guaranteed. The harness through-hole rubber sleeve must be installed reliably. Under normal use, the rubber sleeve shall not be separated from the installation position.

6. Consider preventing electromagnetic interference.

(1) Avoid the electromagnetic interference source of parts, and arrange some signal lines as far away from the interference source, speaker, motor, etc. as possible.

(2) The sensor signal power line shall avoid the power line of high current components, and the interval shall be greater than 300mm.

(3) The grounding wires of some key systems and important systems are arranged at one position respectively to avoid the interference of other grounding wires.

7. Beautiful.

(1) The harness layout shall be natural and not far fetched. The engine room harness can be placed below the beam rather than above; It can be placed inside and outside.

(2) The direction of harness shall be consistent with that of accessories. In the projection direction, it shall be arranged in a horizontal and vertical checkerboard, and the harness shall be arranged obliquely as far as possible.

(3) The harness layout shall be coordinated in color and uniform in size. It is recommended that all engine room harnesses use dark plug-ins. If the harness above the engine is too messy, it is recommended to develop the entire harness guard.

8. Other principles.

(1) The plug-ins shall be arranged vertically as far as possible to prevent dust and water. The plug-in shall not be arranged in the rainwater accumulation area or outside the vehicle, and protective measures shall be taken when it must be arranged in the above areas. Use rubber plug or rubber sleeve and add Vaseline in the plug-in to avoid water in the plug-in oxidizing the terminal surface.

(2) Security. When the car collides, the harness cannot be squeezed. The wire harness is crushed and broken, and the internal short circuit instantly causes fire, causing secondary injury to the driver and passengers.

(3) The harness layout shall be combined with the electrical principle, and the harness direction and outgoing line direction shall be reasonably designed according to the requirements of the electrical principle.

(4) The harness layout shall also be combined with the secondary suppliers, such as plug-in, fixed parts, rubber parts and other manufacturers, and the appropriate design scheme shall be selected through communication between both parties.