The demand for engineering vehicles in the domestic and foreign markets has gradually warmed up, and the wire harness orders have come one after another. However, the traditional production mode can meet the market demand. Through the implementation of the new process, the wire harness manufacturing enterprises have improved their production capacity and reliable quality, and are in a small defeat in the highly competitive wire harness sales market,

Analyze the new process in the harness manufacturing process one by one:

1. Offline

Traditionally, semi-automatic offline machine is used. If it is more simple, manual offline also exists, which not only reduces the production speed, but also increases the labor intensity of operators.

Now, the operator can use an automatic crimping machine to realize the offline according to the offline table, and input the information such as line number, line color, line diameter, line cutting length, line end brake length, line end treatment, whether to wear waterproof bolt, middle brake position and length into the computer, and the automatic crimping machine outputs semi-finished products.

According to the wire diameter of the conductor, the operator inputs the corresponding wire number word height parameters and wire number spacing parameters into the inkjet printer for inkjet coding. Except for the black wire, the emerald color is generally black. The self color inkjet code is mainly used for the special requirements of individual main engine manufacturers for black ground wire. In addition, in order to distinguish the easily confused wire numbers, for some wire number groups such as 18 and 81, it is generally necessary to add '-' after each wire number, such as 18 - and 81 -.

After adjusting the code spraying parameters, the operator shall input the information such as line number, line color, line diameter, line cutting length, line end brake length, line end treatment, whether to wear waterproof bolt, middle brake position and length into the computer according to the offline table:

(1) For the wires that need terminal crimping, the operator shall replace the corresponding wires and terminal die specifications according to the specifications, adjust the pressure to make the tension between the terminal and the wire reach the specified range, adjust the supply speed of the waterproof bolt, conduct at least 3 tension tests, and record the test process. If it is small and qualified, continue to adjust the pressure; If the crimping tension standard is met, the offline can be crimped in batch.

(2) For the wires that need to be crimped with small terminals, the operator can install the corresponding reel according to the offline table, adjust the total length of the offline, the brake shoe length at both ends, the brake shoe value and rotation value required for production, set the daily standard production quantity and binding quantity, confirm the first qualified product and carry out mass production.

(3) Middle brake straightness is a headache for harness manufacturers. Manual middle brake is slow and easy to cause personal injury. Now operators can operate an automatic offline crimping machine to realize the middle brake function, and the wire diameter is from 0.5mm ²-- 6mm ² It can greatly reduce the labor intensity of operators, save time and increase benefits by more than 6mm ² The use frequency of manual brake is still low, and the effect of automatic brake is still poor.

2. Parallel welding

The traditional parallel welding is manual terminal cold pressing, and tin welding is used for those with larger wire diameter, which is time-consuming and polluting. In order to overcome the traditional difficulties, operators use ultrasonic welding machine for welding, and then use heat shrinkable pipe to heat shrinkable solder joints. The ultrasonic welding machine mainly uses mechanical vibration to convert energy to fuse the copper parts with each other, so as to achieve the purpose of welding.

In order to improve the efficiency, the operator can use the pipe cutting machine to cut the heat shrinkable pipe into a disc in advance. After the welding work is completed, the operator directly selects the appropriate heat shrinkable pipe on the station to cover and spot it, and then blow the heat shrinkable pipe with a hot-air gun to make the welding joint waterproof and dustproof. It is worth mentioning that in the process of trial operation of the new process, we also tried a plastic machine to protect the welding joint, and made the welding joint into a square or ellipsoid to install a sealed welding joint.

3. Laser engraving

The object of laser engraving is mainly the connector, which is to mark the code of the four wire ends in the harness, so that the harness can be easily identified during loading and maintenance. The identification connector in the traditional process is only written by the operator with an oily pen. The font is small and easy to identify errors. After a long time, the identification falls off naturally, which is more difficult to identify. When the harness has problems, it increases the work difficulty of the maintenance personnel.

In order to solve such problems, the operator uses the laser marking machine to carve the connector. In order to solidify the engraving position of the connector, the operator uses the connector fixing module to mark the connector. Now, the code of the connector in the harness is standardized, which is very satisfactory to the customer.

4. Sub assembly

Sub assembly is applied to batch harness production. At first glance, this process is small, but its role in batch production can be underestimated. In traditional production, the concept of sub assembly exists in harness production. The operator only applies wires to the nail board one by one according to the drawing, wraps the tape after the wire is laid and tied, and cuts the wire ends. Four harnesses need to waste at least a few meters and more than tens of meters of wires. When the concept of sub assembly is put forward, The harness shall be disassembled as much as possible. The wires at the crimped end r flowing out of the offline process can be inserted into the connector according to the classification of the technical documents, and then flow into the wiring process as a whole (product identification through the process flow sheet) for mass production, which can make the operator form a habitual action and minimize the possibility of wrong hole position of the end R, so as to provide guarantee for the quality of subsequent processes.

5. Wiring

The traditional wiring operators have to nail the board according to the drawing, and the wires are easy to be loose and misplaced during wiring. Now, the wiring harness enterprises convert the drawing into a 1:1 wiring diagram, that is, the physical drawing of the wiring harness made according to the actual size of the standard, and then nail the 1.1 wiring diagram to the wiring board for use. The wiring board generally selects three specifications of wood boards: 1.8m * 0.9m, 2.4m * 0.9m and 3.6m * 0.9m, Compared with the human harness, it can be selected from three specifications or combined by superposition. Four branch points are used to fix the wire fork, and four wire ends use the wire fork and plastic wire clamp to fix the wire. The small is the advantage of the traditional nail winding and fixing. The new process has the advantages of accurate size, saving the wire, reducing the working intensity of operators and improving the production efficiency.

When wiring, the operator first needs to check whether each fork of the wiring board is firmly installed and whether the angle is correct; In general, the ground wire is preferred (the maximum number of parallel points), and then the sub assembly harness and other wires are arranged. During the wiring, the harness must be neat and straight. After the wiring is completed, the mountain wiring personnel use black insulating tape for preliminary flower winding and fixation, and the binding is required to be beautiful, firm and free of bulging_ Then it flows into the binding process.

6. Bandage

In the traditional process of wrapping, the effect of wrapping by the small operator is small, and the inspector is also small to judge whether it is qualified. He can only judge whether the products are qualified by experience. Often, the corrugated pipes with small ICI and the same aperture are wrapped with the same branch, resulting in small thickness and small diameter, and the product quality is affected.

Now, the operator operates with reference to the process documents and the drawings of the standard bellows model. The operator must first check that the laid harness is free of errors, then select and intercept the bellows with appropriate size according to the requirements of the drawings, then wrap it from the connector end to the main ten direction, and finally wrap the open bellows with insulating tape to ensure smooth appearance. The treatment of branch points also requires insulating tape, There is no wire exposure. The treatment of connector end requires to leave the length of bare wire required by the drawing, and ensure that the bare wire is neat.

7. Secondary crimping

Primary crimping refers to the supplementary crimping of the remaining non crimped terminals by the operator using the semi-automatic crimping machine. Primary crimping requires the operator to have a high ability to identify the terminals. The first piece tension test needs to be done for the first crimping in 4 days, and the semi-automatic crimping machine needs to be cleaned before going off duty.

The semi-automatic crimping machine is distinguished according to the end r mold of the small same. The small same mold is made by the crimping machine manufacturer according to the small same terminal. During the actual operation, the operator selects the appropriate crimping machine for production according to the guidance of technical documents and production experience.

After the terminal crimping is completed, the operator shall check the appearance after terminal r crimping. If it is qualified, it needs to be repaired.

8. Plug in

The external quality feedback of the plug-in process is very straightforward, and the problems mainly focus on three aspects: (1) the wrong use of the plug-in model; (2) Wrong terminal insertion sequence; (3) The terminal is not firmly plugged; (4) Auxiliary materials such as blind plug or fixed piece are missing

In order to solve this problem, the wire harness enterprise has formulated the operation instructions to give detailed guidance to the four production steps of the operators, implement the assessment system for the plug-in process personnel, strictly refer to the operation of technical documents, and forcibly strengthen the consciousness of the personnel. In order to strengthen the recognition of the operators for connecting the plug-ins, we put forward the concept of mirror image for the product drawings, that is, it is defined by the outgoing end (the combination of the connector) or the incoming end (the direction of the terminal inserted into the connector), Draw all the connectors on the drawing as a one-dimensional flat diagram of connectors, so that everyone can reduce the possibility of wrong insertion sequence.

9. Inspection

The traditional inspection is to check the connection and disconnection at both ends of the universal agricultural connecting wire. In addition, the small harness calibrator is often used. For mass harness production, the inspection speed and accuracy of the first two methods are as small as that of the aeroelastic calibrator. The actual calculation shows that there is no doubt about the rapidity and accuracy of the aeroelastic calibrator. For the instrument panel harness with many branches and small, it is suitable for the aeroelastic calibrator, The small calibrator previously used has also been replaced by the special instrument panel calibrator.