Wiring knowledge: Cable harness wire, stranded wire products quality defects and prevention

Bundle line, strand of defective products, scrap, the main problem has been twisted, inner or outer line broken, missing strands, single or stranded surface abrasions, single-line back stock, single thread skin, spot scar, brittle broken, arched, there are inclusions, the diameter of the deviation or mixing wrong, the wrong direction, serpentine, a large length of the knot, long unqualified, stranded loose, line disorderly and pressure injury, Scratch, collision, wire and cable conductor Core DC resistance unqualified.

1, over twist

Over-twisting is the twist-twisting phenomenon in the twisted-pair process.

Causes: First, the stranded wire in the traction wheel around the number of laps, generally less than 4 laps, friction too small and slippery, resulting in twisted over. The other is that the tension is loose or the reel does not turn, while the twist is still rotating, resulting in twisted excess.

Elimination method: If the outer line has been severely deformed, serious damage, there is no possibility of repair, only cut off. If the single line is not seriously damaged, you can separate the swivel part of the device from the traction part and rotate it in the opposite direction. To make local twisted parts back, and then with the hands of the core repaired, and the extra single line again around to the receiving reel, the equipment and swivel traction, more loose after the pressure line, pressure, and another manual repair with the mold, This will restart production.

2, a single line in the stranded disconnection, missing strands of the reason for the disconnection:

L) due to the tension of the line is too big pull broken core.

2 single line in the pull system when loose, line is not good, lines across lines, resulting in core break.

3 single line of its own material has cracks, mechanical properties are not brittle broken.

4) Improper placement of the tray, axial shaking, resulting in disconnection.

5 single line jump out of pulley groove, mechanical card broken.

The elimination method ① adjusts the line tension, makes it appropriate. ② pay attention to select into the line, found that there is loose tension, you must go through the back to the machine. ③ pay attention to the operation method, carefully check the position of the line, so that the release of the line does not jump, check a single pass through the place, there is no jump out of the wheel groove phenomenon. ④ to check the surface quality of the core, to see whether there are cracks, slag, spot scars and other defects. If the break occurs in the inner layer, and the break has gone too long, you can not repair, only to cut this section of the missing strand core, if the disconnection occurred in the outer layer, should be repaired and then boot.

3, the stranded line surface scratches, scratches the line core

Causes: Usually one is the line on the wire mouth wear, the second is single jump out of the pulley, three is threading with a wooden pipe or plastic pipe grinding, four is the traction equipment on the board of the positioning pin damage, five is in the die of foreign bodies and other reasons.

Elimination of the method: the replacement of the threading on the Reel and threading the wooden pipe, plastic pipe, check the direction of the core is normal, the protection of the wire core and equipment directly wear, and at any time check the die is intact, and pay attention to the operator, the law.

4, beam line, stranded in single line back stock, pine stock

Cause: First, the tension of the line is uneven, loose tight, Zhang Lisong of the core to go much more, resulting in the back of the stock, the second is too large die hole, can not adjust the role of the appropriate tension, the third is the wrong position of the die, the twist angle is unreasonable, four is the pitch is relatively large.

Beam machine Bundle System 19 strands and above the single core, because the beam line does not have the direction of the difference, can only be the same beam system, so the combination of the core is irregular, the current manufacturers mostly use double pitch beam system, so the bundle wiring harness system more than 19 strands of the core, back stock, pine stock phenomenon than stranded line serious.

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Elimination method: on the bundle line (L-strand products) One is to improve the wiring device, the use of more advanced single line tension amplifier, so that each single wire tension can be adjusted and controlled. The second is to use the guide die, the diameter of the guide die for the beam line calculation of the outer diameter of 97%. This guide mode can adjust the tension properly. Three is to switch to one-pitch beam machine, this beam machine beam system products, can reach the level of the stranded wire. Four is to the back of the Strand, pine strands of serious beam core, the use of the method of complex repair, can also achieve the requirements of use. Five is to adjust the pitch ratio appropriately.

For stranded product back stock, Pine stock elimination Method: first, adjust the line tension, make it even. The second is to change the die, then the core in the mold hole do not loose, pay attention to the trumpet, if the trumpet has been damaged, can not be made. The third is to adjust the position of the die seat, so that the stranding angle of the stranded wire is reasonable. Four is if the hinge-joint spacing is large, should be reduced properly.

5, stranded line of single slot or surface defects

Causes: Single-line surface of the hemp pits, spot scars, triangular crack, slag and other defects, mainly material, of course, the core surface fragmentation phenomenon, also does not rule out the type of wire mold unreasonable and produced, at this time need concrete analysis. And the core surface of the groove is continuous, generally is caused by pull, pull line lubrication conditions deteriorated, the surface of aluminum and caused by the continuous groove, it is possible that the stranded wire die sticky foreign body caused.

Elimination: For the pull line when the aluminum wire groove, you should first check the cable lubrication effect can meet the requirements of the cable, need to change the lubricant in time, replace the pull line mold, or eliminate the sticky online mold on the sundries, carefully check into the lines, unqualified to enter the line to be promptly excluded, while checking the pressure mode has no damage, there is no debris, to timely repair and replacement.

6, single line diameter is big, suddenly small or mixed with the wrong line core

The reason: found in the strand of single line diameter is too poor or mixed with the wrong core, the main reason is not to seriously implement the technical provisions, another reason is the management of a certain problem.

Elimination Method: If the length of the wrong line is not long, can be grilled down, change lines, repair by line repair method. If the length is too long, can not repair, only the next machine, separate treatment. Therefore, before the machine, the operator should be carefully inspected and measured. Of course, managers should also provide a guarantee method, such as whether more AWG, tolerance is reasonable, production scheduling is appropriate, according to the PDCA principle of serious thinking about the problems of management, to avoid man-made bad products and waste production.

7, stranded wire core pine stock

The reason for the result:

(l) The pitch is too large, causing the strand core to be not solid.

(2) The pressure die hole type is too big, does not have the compaction and the adjustment function. The die trumpet is too large or worn and damaged.

(3) The tension of the line is uneven, loose and tight.

(4) The pitch ratio of each layer is not fit.

(5) The core State does not conform to the technical requirements, especially the aluminum core.

(6) The position of the wire splitter and die holder is improper.

Elimination method: First strict process discipline, the implementation of process procedures, appropriate reduction of excessive pitch, adjust the line tension and die. The position of the splitter to the die seat, according to the different structure, the general transfer to 200~250mm is advisable. For stranded some of the most tensile strength of the strand, you can use the combination of mold method, also has a good effect, of course, the operator according to the procedures stipulated in the process of operation, is very important.

8, stranded in the wrong direction, stranded pitch is not qualified (mainly large)

Cause, the direction of error is mainly to judge the wrong, the direction of the hinge is determined as figure 7-1. Operators in the operation, should strengthen responsibility, strictly according to the process card implementation, and should strengthen the flow check to prevent man-made bad products and waste production.

9, line of chaos, pressure lines

The reason: Stranded products are generally in a tray supply. Large section, to a root of the row, especially the bottom line to pay special attention to the row, in the line to turn, because there is a stay, should pay special attention to the upper and lower layers can not leave too large gap between the line to be appropriate, too large easy to create pressure lines.

Elimination of the method: first of all to adjust the line tension, when the manual line, one can arrange the move is appropriate, the second according to the diameter of the core to replace the line section, the first layer is the key, must be arranged neatly; row second, in the adjustment layer, to carry out manual line, to ensure the quality of line. Third, to strengthen the operational responsibility to observe the quality of the line at any time, found that the problem to be adjusted in time, pay attention to fixing the two threads and stay away from the edge.