After the online two-dimensional drawings of the wiring harness are produced, the production process of the wiring harness needs to be arranged. The basic data from the drawings to the output process provide equipment and terminal production parameters for the development department, material consumption lists for the procurement department, and basic operating content for the production department. A good process can also be optimized in the process of wiring harness manufacturing, including process optimization, equipment optimization, process optimization, and process optimization. The general production process of custom wire harness is as follows.
The cutting refers to the cutting and stripping of the original wire (coil or barrel wire) according to the process department's compiled process lines and tubes. When cutting, attention should be paid to following the requirements and not allowing negative deviations, confirming that the raw material specifications, models, colors, and sizes meet the requirements, and carefully implementing the process flow content.
The first assembly is for the preparation of crimping, usually including processes such as threading heat shrink tubing, rubber tubing, threading retracted plugs, threading waterproof plugs, and stripping three-core wire and two-core wire. Strictly following the operating instructions of such processes can explain complex situations according to the crimping process diagram. The cable wiring harness assembly process should be particularly careful, and the process engineer should be very familiar with the plugs and terminals. Special attention should be paid when assembling three-core wires. If the process requires cutting or using PVC full-encapsulation, the quality control points should be followed to prevent electric leakage or fire.
Crimping is a way to use mechanical equipment such as a crimping machine to press the terminal and the original wire together to connect them. After crimping the terminals, some terminals need to be heat-shrunk. Heat shrinking means evenly baking the heat-shrinkable tube on the crimped bare wire or terminal until it wraps around the terminal or the exposed wire. Heat-shrinkable tubes can be divided into single-layer and double-layer types. Single-layer heat-shrinkable tubes are mainly used for connection on the busbar, while double-layer ones are generally used for riveting points. Their role is to protect and prevent electric leakage.
Pre-assembly is to arrange the semi-finished wires that have been crimped and assembled according to the drawing or pre-assembly process, plug the protective sleeves, wrap them, mark them, attach the accessories, wrap them, and finally obtain semi-finished or finished products. The process operation instructions for this process should be compiled and executed, and the semi-assembly or full-assembly of the wiring harness product should be completed. It is necessary to pay attention to the quality requirements of one insertion, two listening, and three retraction when inserting the protective sleeves. The rationality of the pre-assembly process directly affects the efficiency of the final assembly. It also reflects the technical level of the process engineer. If the pre-assembly part is too few or the wire routing of the assembly is unreasonable, it will increase the workload of the hanging board personnel and slow down the speed of the assembly line. Therefore, the process engineer needs to summarize experience on the spot to formulate a reasonable process.
Assembly is the operation following pre-assembly, and it completes the outer covering protection of the wiring harness, the insertion of the terminals, the wearing of the accessories, the winding of the marking points, and the bundling of the straps according to requirements. This step is the finishing work of the finished cable wiring harness, so each process needs to be manually operated, so it is very important to allocate the tubes required for this process and the pre-assembly process.
Arrange the tubes required at the workstations according to the process to make production and process consistent.
There are two types of finished product inspections: appearance inspections and electrical inspections. Appearance inspections include size measurements, check of damage to protective covers, check of complete accessories, and check of correct bundling of marking straps, etc. Electrical inspections mainly test the conductivity and air tightness of the wires. Only cables and wiring harness products that pass the inspection are allowed to enter the warehouse.