Process flow of wire harness manufacturing

The process flow of wire harness manufacturing can be divided into the following steps:

(1) Blanking

Cutting is to cut off and peel the original wire (usually coiled wire and barrel wire) according to the process requirements.

When cutting material, it should be noted that the deviation is generally adjusted to about +10, and negative deviation cannot occur.

When the feeding machine is blanking, if there is an unstable situation, it should be debugged or repaired in time.

The feeding machine generally has a fan to exhaust heat. If the temperature discharged is abnormally high, the machine should be turned off and checked.

The cutting tool of the blanking machine should be replaced in time after long-term wear and tear.

When the material is unloaded, a label should be attached, and the writing on the label should be neat and clear. The content of the label includes the product model used, the length of the original wire, and the length of the peeling at both ends.

The finished materials should be placed in categories according to the positions specified in the original line area.

(2) The first sub-packaging (pre-packing)

       The first sub-assembly is to prepare for crimping, which usually includes the following steps: threading the silicone tube, threading the back-pulled connector, threading the waterproof plug, and stripping the three-core and two-core wires. For some relatively large terminals, if you need to pass through a small silicone tube (such as a silicone tube with a diameter of Φ6), you must first wear the silicone tube at the sub-packaging place, and then crimp the terminal, otherwise the silicone tube will cause the terminal to be too large. But can't pull it. Pull back terminals, such as 1216 2190 and other connectors, must first pass the wire into the connector, and then wait for the terminal to be crimped. At this point, special care should be taken in the sub-assembly process, and the technicians are required to have a good understanding of connectors and terminals. Special attention should be paid to the process of dividing the three-core wire if it is required to cut the three-core wire or wrap it fully with PVC, it must be operated in accordance with the process, because some three-core wires are made of conductive materials for their insulating skins. Without protection, it will easily lead to leakage or fire, and the consequences are very serious.

(3) Crimp

      Crimping is a way of using mechanical equipment such as a crimping machine to crimp the terminal and the original wire together so that it can play a connecting role. When crimping general terminals, we should pay attention to the following points:

1) Before the tooling personnel debug the mold, they must not operate at will.

2) When crimping, we must first test the tension and the height of the terminal. In this way, we can use the measured actual tension value and height value as a standard for whether the product meets the requirements.

3) If there are other abnormal factors that the terminal is stuck in the jaw during the crimping process, the power supply of the motor should be cut off immediately, and then the person in charge should be informed in time.

4) When crimping, do not talk to each other, concentrate your thoughts and work hard.

5) Be sure to cut off the power supply after the crimping is completed to avoid unnecessary work accidents.

6) The equipment engineer should check whether there is any damage in the process of changing the mold. If the crimping jaw is damaged, it should be replaced in time. Always protect the mold, clean up the accumulated chips in time, regularly oil and check and debug. If there is a problem with the mold, a comprehensive inspection should be done.

      Some terminals require heat shrinking after the crimping process is complete. Heat shrinking is to put the heat shrinkable tube covering the bare wire or terminal on the air gun and bake it evenly until it wraps the terminal or the bare wire. Heat shrinkable tubes can be divided into single-layer and double-layer. The single-layer heat-shrinkable tube is mainly used for grounding, while the double-layer is generally used for riveting joints. Their functions are the same - to protect and prevent leakage.

      During the baking process of the heat-shrinkable tube, attention should be paid to constantly flipping and baking, and the surface of the wire body and the heat-shrinkable tube should not be carbonized. If it is a double-layer heat-shrinkable tube, the liquid flowing out of the heat-shrinkable tube should be fully uniform. wraps the wire body. Sometimes there will be bending deformation at the end during the baking process. This is impossible in principle, but it is difficult to avoid in actual operation, so as long as it does not affect the use, it is normal if the bending is not too serious.

(4) Assembly

      It is the process of arranging, wiring, winding and wrapping the semi-finished wire that has been crimped and sub-packaged according to the position and line specified by the chopping board, and finally the finished product is obtained. The assembled breadboard is best printed on photo paper. The chopping board diagram should include the following contents: the length of each section; the size, length and position of the corrugated tube and silicone tube; the position of each connector and the wire size, specification, color, hole position of the wire on the connector, etc.; Direction distribution; nut positioning holes; precautions and special technical instructions, etc.

      During the operation, the operator should strictly follow the regulations of the chopping board to sub-assemble and assemble, and the problem should be raised to the technician in time. If you accidentally insert the wrong terminal or other special situations during the operation, you should notify the person in charge to solve it as soon as possible.

      When plugging the terminals, the following requirements should be followed: one plug, two listens, and three pulls. Some terminals have positive and negative points when they are inserted, so when you encounter difficulties in insertion, you should adjust the insertion direction of the terminal in time, and do not press hard. A slight "pop" will be heard after normal insertion. When you hear the sound, don't push hard, but pull back to see if there is any looseness. If the terminal cannot be inserted no matter which direction it is turned, it may be that the terminal is pressed incorrectly, or the connector is delivered incorrectly. At this time, the technician should be notified as soon as possible to conduct a detailed check to determine its rectification plan. The chopping board contains a lot of information. The operator must take good care of the peritoneum above it, and it is strictly forbidden to scribble and scratch with sharp objects such as knives. The material used for the chopping board is a press-formed sawdust board, so it should be light when lifting and not beating.