Function introduction of automobile harness

In modern automobile, there are many automobile harnesses, and the electronic control system is closely related to the harness. Someone once made a vivid analogy: if the functions of microcomputer, sensor and actuator are compared with human body, it can be said that microcomputer is equivalent to human brain, sensor is equivalent to sensory organ, and actuator is equivalent to motor tube, then the harness is nerve and blood vessel.

Automobile harness is the main network of automobile circuit. It connects the electrical and electronic components of automobile and makes them function. Without harness, there will be no automobile circuit. At present, whether it is an advanced luxury car or an economical ordinary car, the wiring harness is basically the same in form, which is composed of wires, connectors and wrapping tape. It should not only ensure the transmission of electrical signals, but also ensure the reliability of the connecting circuit, supply the specified current value to the electronic and electrical components, prevent electromagnetic interference to the surrounding circuits, and eliminate the short circuit of electrical appliances.

In terms of function, the automobile harness can be divided into two types: the power line carrying the power of the driving actuator (actuator) and the signal line transmitting the input command of the sensor. The power line is a thick wire that carries large current, while the signal line is a thin wire that does not carry power (optical fiber communication); For example, the cross-sectional area of the wire used in the signal circuit is 0.3 and 0.5mm2.

The cross-sectional area of 1 and 3 power supply components is 25mm2, while the cross-sectional area of 1 and 3 power supply components is 0.5mm2; Special circuits (starter, alternator, engine grounding wire, etc.) have different specifications of 8, 10, 15 and 20mm2. The larger the cross-sectional area of the conductor, the greater the current capacity. In addition to considering the electrical performance, the selection of wires is also restricted by the physical performance when on-board, so its selection range is very wide. For example, the frequently opened / closed door on a taxi and the wire across the body should be composed of wires with good flexural performance. The conductor used in high temperature parts generally adopts the conductor coated with vinyl chloride and polyethylene with good insulation and heat resistance. In recent years, the use of electromagnetic shielding wires in weak signal circuits is also increasing.

With the increase of automobile functions and the universal application of electronic control technology, there are more and more electrical parts and wires. The number of circuits and power consumption on the automobile increase significantly, and the harness becomes thicker and heavier. This is a big problem to be solved. How to make a large number of wire harnesses in the limited automobile space, how to arrange them more effectively and reasonably, and how to make the automobile wire harness play a greater role has become a problem faced by the automobile manufacturing industry.

Production technology of automobile harness

With the continuous improvement of people's requirements for comfort, economy and safety, the types of electronic products on the automobile are also increasing, the automobile harness is becoming more and more complex, and the failure rate of the harness is also increasing accordingly. This requires improving the reliability and durability of wire harness. Many people are interested in the process and production of automobile wire harness. Here, Haozhi electronics makes a simple description of the knowledge of automobile wire harness process and production. You only need to spend a few minutes to read it.

After the two-dimensional product drawing of automobile harness comes out, the production process of automobile harness should be arranged. The process serves the production. The two are inseparable. Therefore, the author combines the production and process of automobile harness.

The first station of wire harness production is the opening process. The accuracy of the opening process is directly related to the whole production progress. Once there is an error, especially the short opening size, it will lead to rework of all stations, time-consuming and laborious, and affect the production efficiency. Therefore, when preparing the wire opening process, we must reasonably determine the wire opening size and stripping size of the conductor according to the requirements of the drawing.

The second station after opening the line is the crimping process. The crimping parameters are determined according to the terminal type required by the drawing, and the crimping operation instructions are made. If there are special requirements, it is necessary to indicate them on the process documents and train the operators. For example, some wires need to pass through the sheath before crimping. It needs to pre assemble the wires first, and then return from the pre assembly station before crimping; In addition, special crimping tools are used for puncture crimping, which has good electrical contact performance.

Then comes the pre assembly process. First, prepare the pre assembly process operation manual. In order to improve the general assembly efficiency, the pre assembly station should be set for complex wire harnesses. Whether the pre assembly process is reasonable or not directly affects the efficiency of the general assembly and reflects the technical level of a craftsman. If the preassembled part is less assembled or the assembled wire path is unreasonable, it will increase the workload of the general assembly personnel and slow down the speed of the assembly line, so the technicians should often stay on the site and summarize constantly.

The final step is the final assembly process. Be able to compile the assembly platen designed by the product development department, design the specifications and dimensions of tooling equipment and material box, and stick the numbers of all assembly sheaths and accessories on the material box to improve the assembly efficiency. Prepare the assembly contents and requirements of each station, balance the whole assembly station, and prevent the situation that the workload is too large and the speed of the whole assembly line is reduced. To achieve the balance of working positions, the process personnel must be familiar with each operation, calculate the working hours on site, and adjust the assembly process at any time.

In addition, the harness process also includes the preparation of material consumption quota schedule, man hour calculation, worker training, etc. because the technical content value is not high, these will not be described in detail. In a word, the content and quality of automotive harness in vehicle electronic technology has gradually become an important index to evaluate vehicle performance. Automobile manufacturers should pay special attention to the selection of wire harness, and it is also necessary to understand the process and production of automobile wire harness.