Key points of quality control in wire harness manufacturing

Wire harness manufacturing is a complex process that involves multiple links and processes. Strict quality control is the key to ensuring the performance, safety, and reliability of wire harnesses during the manufacturing process. The following are the key quality control points in wire harness manufacturing:

1. Quality control of raw materials

Wire material: Ensure that the purity and conductivity of the wire material (such as copper) meet the requirements

Insulation material: Choose insulation materials that are heat-resistant, flame-retardant, low smoke and halogen-free, such as cross-linked polyethylene (XLPE) or silicone rubber

Shielding material: For wire harnesses that require shielding, choose high-quality shielding materials such as braided copper mesh or aluminum foil

2. Production process control

Offline process:

When stripping the wire, ensure that the stripping length meets the requirements, the insulation surface is uniform, and the wire core is not cut or damaged

After the wire stripping is completed, a protective cover should be placed on the stripping head to prevent the wire core from being scattered

Terminal crimping:

Verify the type, specification, color, and terminal specifications of the wires on the process card

Conduct a pull-out test to ensure that the terminals and wiring harness are tightly connected

Appearance inspection: Check whether the terminal crimping is good, there is no wire leakage, and whether the insulation layer is pierced or cut

Pre installation process:

Check the type of sheath and wire specified on the process card, and inspect the quality of the sheath, wire, and terminal crimping

After inserting the terminal, the appearance must be neat and in place, without any deviation

Final assembly process:

According to the process requirements, assemble the clips and tie and wrap them on the assembly board

Ensure that the wiring harness is hung on the rack after assembly to avoid damage caused by dragging it on the ground

3. Testing and Inspection

Electrical testing:

Perform electrical continuity testing to ensure that each wire is correctly connected and not broken or short circuited

Perform insulation resistance measurement, check if the insulation layer on the wire is intact and prevent leakage

Conduct a voltage withstand test to ensure the insulation performance of the wiring harness under high voltage

Mechanical testing:

Perform mechanical stress testing to ensure that the wiring harness can withstand physical forces such as vibration or bending without damage

Appearance inspection:

Check the appearance of the wiring harness for cleanliness, no damage, no burrs, and other issues

Check whether the pins in each sheath are skewed, and whether the rough and tight wrapping of the wire harness is qualified

Dimensional inspection:

Check if the length, diameter, and bending radius of the wiring harness meet the design requirements

4. Final inspection

Power on inspection:

Connect the protective sheaths and connectors of the wiring harness to the testing equipment, conduct circuit judgment, and ensure that all are qualified

Products that fail the inspection must be marked with red tape to indicate the non-conforming areas and handed over to designated maintenance workers for repair

Appearance dimension inspection:

Starting from one end of the wiring harness, check one by one in one direction to avoid omissions

After passing the inspection, affix a qualified label and pack the goods for storage

5. Quality Management System

Establishing a sound quality management system: ensuring consistency and stability of product quality

Clear inspection methods and tools: Develop detailed inspection steps and procedures, using tools such as electric bridges, resistance meters, and insulation resistance meters

Handling of non-conforming products: Clarify the handling methods for non-conforming products, such as rework, repair, downgraded use, or scrap

Accountability mechanism: Trace and analyze the causes of non-conforming products, hold relevant responsible persons accountable and punish them