- Jul 16, 2020-
Over-twisting refers to the twisting phenomenon in the twisting process. Causes:
1. The number of turns of the twisted wire on the traction wheel is not enough, generally less than 4 turns, the friction is too small and slips, resulting in excessive twisting.
2. The tension of the take-up wire is loose or the take-up reel does not rotate, and the rotor is still rotating, resulting in excessive twisting.
elimination method:
If the outer single wire has been severely deformed and the damage is serious, there is no possibility of repairing it, and only cut. If the single wire is not severely damaged, you can separate the rotating part of the equipment from the traction part, turn it in the opposite direction of the twisting, and return the partially twisted part, then repair the core by hand, and wind the excess single wire to On the take-up reel, combine the equipment and the rotating body. After the loose over-pressure line mold, press the line forcefully and manually repair it with the mold, so that the production can be restarted.
Single wire breaks during twisting and its causes
1. The wire core is broken due to excessive pay-off tension.
2. When the single wire is drawn, it is loose and disorderly, the wiring is not good, and the crimping wire crosses the wire, causing the wire core to break.
3. The material of the single wire itself is cracked, and the mechanical properties are not good and brittle.
4. Improper installation position of the pay-off reel and axial shaking, causing wire breakage.
5. The single wire jumps out of the pulley groove and the mechanical jam is broken.
elimination method:
1. Adjust the pay-off tension to make it appropriate.
2. Pay attention to the selection of the incoming line. It is found that there is looseness when pulling the line, and it must be rewinded before getting on the machine.
3. Pay attention to the operation method, carefully check the position of the pay-off reel to ensure that the discharged line does not swing or jump, and check the place where the single line passes to see if there is any phenomenon of jumping out of the guide wheel groove.
4. Check the surface quality of the wire core to see if there are defects such as cracks, slag inclusions, and scars. If the disconnection occurs in the inner layer, and the broken ends have gone too long, it cannot be repaired. Only cut off the missing strand core. If the disconnection occurs in the outer layer, the thread should be repaired before the machine is turned on.
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The surface of the stranded wire is scratched and the core is scratched
Usually one is the wear of the thread nozzle on the spool, the other is that the single wire jumps out of the pulley, the third is that the thread is worn through with wooden or plastic pipes, the fourth is that the positioning pins on the push board of the traction equipment are damaged, and the fifth is that there are foreign objects in the die. the reason.
elimination method:
Replace the threading nozzle on the spool and the wooden tube and plastic tube used for threading, check whether the direction of the core is normal, protect the core from direct wear to the equipment, and check whether the die is intact at any time, and pay attention to the operation method.
Single wire back strand and loose strand in bundle wire and stranded wire
1. The pay-off tension is uneven, the tension is tight, and the tension of the thread core goes too much, causing back strands.
2. The die hole is too large to properly adjust the tension.
3. Improper die position, unreasonable twist angle, fourth, relatively large pitch, etc.
The single wire cores of 19 strands and above are bundled by the wire harness machine. Since the wire harnesses have no difference in direction, they can only be bundled in the same direction, so the wire cores are combined in an irregular state. At present, most manufacturers use double-pitch bundles. Wire cores with more than 19 strands in the wire harness system have more back strands and loose strands than twisted wires.
elimination method:
Paired wire harness (beam products with more than one strand)
1. Improve the pay-off device of the beam line, and adopt a more advanced single-line tension pay-off device, so that the tension of each single line can be adjusted and controlled.
2. Using a guide die, the aperture of the guide die is 97%% of the calculated outer diameter of the beam line. In this way, the tension of the guide die can be adjusted appropriately. 3. Switch to single-pitch wire harnessing machine, which can reach the level of twisting wire. The fourth is to use the over-mold rewinding method to repair the back strands and severely loose strands to meet the requirements of use. Fifth, adjust the pitch ratio appropriately.
For stranded wire products
1. Adjust the pay-off tension to make it even.
2. Change the die so that the core is not loose in the die hole. Pay attention to the bell mouth of the mold. If the bell mouth is damaged, it cannot be used.
3. Adjust the position of the die seat to make the twisting angle of the stranded wire reasonable. Fourth, if the stranding pitch is large, it should be appropriately reduced.
5. Grooves or surface defects in single wires in stranded wires
cause:
The defects such as pits, scars, triangle cracks, slag inclusions on the surface of the single wire are mainly caused by the material. Of course, the surface of the wire core is broken, and the unreasonable hole pattern of the drawing die is not ruled out. At this time, specific Specific analysis of the situation. The continuous grooves on the surface of the wire core are generally caused by the wire drawing. The lubrication condition of the wire is deteriorated and the surface is sticked to aluminum. The non-continuous grooves may be caused by foreign matter sticking to the stranding die.
Remedy:
For aluminum wire grooving during drawing, first check whether the lubrication effect of the drawing wire can meet the requirements of the drawing wire. It is necessary to replace the lubricating oil in time, replace the drawing mold, or remove the debris on the wire mold, carefully check the incoming wire, and for the unqualified The incoming line should be removed in time, and at the same time, check whether the crimping die is damaged, whether there is debris, and repair and replace in time.