Quality control in the production process of automotive wiring harness

Release time:

2019-07-07

Automotive low-voltage wire harness is composed of wire, connector, terminal, clamp, sheath, tape, corrugated pipe, PVC pipe, bracket, heat shrink sleeve and fuse box and other materials assembly. Wiring harness is connected to each other and transmits electrical and electrical signals to the electronic appliances on the car, which has the image title of "car nerve". Each harness has different functions in the vehicle, which is divided into main harness, cockpit harness, instrument panel harness, door harness, ceiling harness, engine harness and so on.

1 Structure and function of wiring harness

2 Common wiring harness defects

Common wiring harness defects include terminal withdrawal, incorrect relay/fuse assembly, incorrect buckle position, poor relay operation, short circuit, damaged insulation, open circuit, poor contact, etc. In addition to the natural causes of failure (long service life, oxidation/deformation of the harness end), the damage of the harness caused by the failure of electrical equipment, and the subjective human factors when assembling or servicing automotive parts, many of these defects can be prevented or eliminated during the production process of the harness.

3 Quality control in the production process

The general manufacturing process of automotive wire harnesses is incoming inspection, raw material storage, tangential, crimping, ultrasonic welding, heat shrink sleeve, twisted wire, terminal insertion, assembly covering and accessories (felt, tape, PVC pipe, bellows, pins, cable ties and brackets, etc.), assembly, wire harnesses inspection (appearance, size, electrical properties and air tightness, etc.), packaging and storage. The flow diagram is shown in Figure 1.

Automotive wiring harness manufacturers say that on the basis of personnel training, equipment maintenance, routine inspection and other guarantees, wiring harnesses will still fluctuate in quality for many reasons. Therefore, through professional advantages and experience feedback, we have refined the key monitoring points for each process and implemented them at the supplier, helping the supplier to improve the first-line pass rate and 0 km quality performance.

3.1 Tangent one inkjet one crimp

1) Equipment ① The application parameters of the equipment are set by the process or production supervisor, and cannot be manually interfered by the operator; ② The interface for setting parameters on the machine is closed for the operator; ③ Whether it is automatic crimping equipment or semi-automatic crimping equipment, it is necessary to be equipped with pressure monitoring devices; ④ In case of an anomaly, the device will automatically destroy the non-conforming crimping or automatic locking system.

2) Process 1 Confirm that the wire is not bent, no knot, no stress, and does not fall on the ground; ② Manual re-cutting, peeling and crimping operations are not allowed, and there are no prohibited tools (scissors, pliers, etc.) in the workshop; (3) CFM (Crimp ForceMonitoring) teaching should be carried out before starting crimping; (4) The crimped terminal is protected by a wire cup, where the terminal has no contact with the bottom of the wire cup, and the wire cup can not be tied to the terminal, but tied to the insulator; ⑤ In the case of double crimping, if the superimposed crimping, the wire with a smaller cross-sectional area should be placed below; If the parallel crimping, the cross-sectional area of the two wires should be the same.

Key words:

Pre

What problems should we pay attention to in wiring harness production?

What are the causes of wiring harness failure

Pre

What problems should we pay attention to in wiring harness production?

What are the causes of wiring harness failure