Quality defects and prevention of cable bundle wire and stranded wire products

Bundles, strands of defective products, waste products, the main problems are over-torsion, inner or outer single-line break, lack of strands, single-line or strand surface scratches, single-line back strands, single-line peeling, spotted, brittle, Arching, inclusions, wire diameter error or misplacement, twisted direction wrong, serpentine, twisted pitch, unqualified length, stranded loose strands, wire chaos and crush, scratch, bruise , wire and cable conductive core DC resistance is not qualified.

1, over twisted

Over-torsion means that the twisting is excessively twisted during the twisting process.

The reason is as follows: First, the number of turns of the strand on the traction wheel is not enough, generally less than 4 turns, the friction is too small and slips, causing excessive twisting. The second is that the tension is loose or the take-up reel does not turn, and the swivel is still rotating, causing excessive twisting.

Remedy: If the outer single line has been severely deformed, the damage is serious, there is no possibility of repair, only the cut. If the single wire is not seriously damaged, the rotating part of the device and the pulling part can be separated, and rotated in the opposite direction of the twisting, so that the partial twisted portion is retracted, and the core is repaired by hand, and the excess single wire is wound again. On the take-up reel, pull the equipment and the swivel into one. After the loose over-pressure mold, press the line and use the mold to repair it manually, so that it can be restarted.

2. The reason why the single wire is broken during stranding, and the single strand broken wire is produced:

l) The wire core is broken due to excessive tension of the pay-off wire.

2) The single wire is loose during drawing, the cable is not good, and the crimping line is over the line, causing the core to break.

3) The material of the single wire itself has cracks, and the mechanical properties are not brittle.

4) The installation position of the pay-off reel is improper, and the axial direction is shaken, causing disconnection.

5) The single wire jumps out of the pulley groove and the mechanical card is broken.

Method of exclusion:

1 Adjust the tension of the take-up to make it appropriate.

2 Pay attention to the incoming line and find that there is looseness when pulling the wire. It must be rewinded before it can be used.

3 Pay attention to the operation method, carefully check the position of the pay-off reel, so that the discharged line does not swing, check the place where the single line passes, and whether it jumps out of the guide wheel groove.

4 Check the surface quality of the core to see if there are any defects such as cracks, slag inclusions, and spots. If the broken wire occurs in the inner layer and the broken end has gone too long, it cannot be repaired. Only the missing core is cut. If the broken wire occurs in the outer layer, the wire should be repaired and then turned on.

3, the surface of the twisted wire is scratched, scratching the core

Causes: Usually, the nozzle on the distribution board is worn, the second is the single-line jump-out pulley, the third is the threading with the wooden tube or the plastic tube, and the fourth is the locating pin on the traction device's push-pull board. The fifth is the compression mold. There are foreign objects and other reasons.

Elimination method: replace the threading nozzle on the distribution plate and the wooden pipe and plastic pipe for threading, check whether the wire core is normal, protect the wire core from direct wear and tear, and check whether the die is intact at any time, and pay attention to the operation method. .

4, single line back strand, loose stock in the bundle line, stranded wire

Causes: First, the tension of the pay-off thread is uneven, loose and tight, the core of the loose tension is much more, resulting in back strands. Second, the die-shaped hole type is too large, and the tension is not properly adjusted. The third is the stamper. Improper position, unreasonable twist angle, and fourth, the pitch is relatively large.

The wire harness machine makes 19 strands and above single wire cores. Because the beam wires have no difference in direction, they can only be bundled in the same direction. Therefore, the wire cores are in an irregular state. At present, most manufacturers use double pitch beams, so bundles Wire harnesses with more than 19 strands of core, back strands, and loose strands are more serious than stranded strands.

Remedy: For the beam line (more than one strand of the bundle), the first is to improve the wire harnessing device, using a more advanced single-line tensioner, so that the tension of each single wire can be adjusted and controlled. The second is to use a guiding die. The aperture of the guiding die is the beam diameter to calculate the outer diameter 叨97%%. Thus, the guide mold can appropriately adjust the tension. The third is to use a single-pitch wire harness machine, which can reach the level of the stranded wire. The fourth is to the back strands, the loose strands of the loose strands, the use of overmolding to repair the method, can also meet the requirements of use. The fifth is to adjust the pitch ratio appropriately.

For the back strand of the stranded product, the method of eliminating the loose strand: First, adjust the tension of the pay-off to make it uniform. The second is to change the stamper, then the core should not be loose in the die hole. Pay attention to the bell mouth of the die. If the bell mouth is damaged, it will not be able to. The third is to adjust the position of the die holder so that the twisting angle of the strand is reasonable. Fourth, if the twisting pitch is large, it should be appropriately reduced.

5. Single wire groove or surface defect in stranded wire

Causes: defects such as pits, spotted ridges, triangular cracks, and slag inclusions on the surface of a single wire are mainly caused by materials. Of course, the surface of the core has a fragmentation phenomenon, and it is not excluded that the shape of the wire die is unreasonable. It is necessary to analyze the specific situation. The surface of the core is continuous in the groove, which is generally caused by the pulling of the wire. The lubrication condition of the wire is deteriorated, and the surface is adhered to aluminum. The groove is not continuous, and may be caused by the twisted wire die.

Elimination method: For the aluminum wire grooving when pulling the wire, first check whether the lubrication effect of the cable can meet the requirements of the wire drawing. It is necessary to replace the lubricating oil in time, replace the wire drawing die, or remove the debris on the wire mold, and carefully check the incoming line. Unqualified incoming lines should be removed in time, and the pressure line die should be inspected for damage, and if there are any debris, it should be repaired and replaced in time.

6, single wire diameter is too large, small or misplaced core

Cause: The single wire diameter is too poor or mismatched in the stranding. The main reason is that the process regulations are not carefully implemented. Another reason is that there are certain problems in management.

Elimination method: If the length of the wrong core is not long, you can squat down, change the line again, and repair it according to the line repair method. If the length is too long, it cannot be repaired. Therefore, the operator should carefully check and measure before going to the machine. Of course, managers should also provide a guarantee method, such as whether the wire gauge is too much, whether the tolerance is reasonable, whether the production scheduling is properly arranged, and seriously consider the management problems according to the PDCA principle, and avoid the generation of artificial defective products and waste products.

7, stranded core loose stocks

Causes:

(l) The pitch is too large, resulting in a stranded core that is not solid.

(2) The die hole type is too large to achieve compaction and adjustment. The wire mold flare is too large or worn and damaged.

(3) The tension of the pay-off thread is uneven and loose.

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

(5) The core state does not comply with the process regulations, especially the aluminum core.

(6) Improper position of the splitter and the die holder.

Remedy: First, strict process discipline, implementation of process procedures, appropriate reduction of excessive pitch, adjustment of the tension of the pay-off and compression molding. The position of the splitter to the die holder is generally adjusted to 200~250mm according to different structures. For twisting some strands with particularly high tensile strength, a combination of molds can be used, and good results are also obtained. Of course, it is very important for the operator to operate according to the method specified in the process operation rules.

8, the twisting direction is wrong, the twisting pitch is unqualified (mainly too large)

Cause: The wrong direction is mainly to judge the error. The operator should strengthen the sense of responsibility during the operation, strictly follow the process card, and strengthen the flow check to prevent the generation of artificial defective products and waste products.

9, the cable is chaotic, pressing line

Cause: Stranded products are generally supplied in trays. For large sections, it is necessary to arrange one root, especially the bottom line. Pay special attention to the alignment. When the cable is turned, because there is a stop, special attention should be paid. There should not be too much clearance between the upper and lower layers. Appropriate, too large is easy to cause pressure lines.

Exclusion method: Firstly, adjust the tension of the take-up thread. When manually arranging the line, it is better to arrange the movement. Secondly, according to the diameter of the core, replace the line pitch. It is the key to arrange the first layer. It must be arranged neatly. The second layer, in the layering, manual wiring, to ensure the quality of the cable. The third is to strengthen the operational responsibility and observe the quality of the cable at any time. If problems are found, adjust them in time, and pay attention to fixing the two wires and the distance between the edges.