A small wire drawing machine breaks wire at startup, but the take-up machine keeps running. The core reason is that the wire break detection signal does not successfully make the take-up control system execute a stop command. The problem is usually in signal generation or signal transmission. Hansheng Automation can machine dies, guide wheels, tension wheels, and other precision parts from customer drawings for replacement of worn components.
1. Causes of wire breakage
Wire breakage is the signal source for stopping. If the wire does not break, the take-up machine should not stop. Breaking at startup mainly comes from equipment and process setup.
Die problems: incorrect die matching, rough die holes, or an overly long sizing zone. Stress concentrates at the moment of speed increase and causes breakage. Breaks often happen between the transition die or exit die and the haul-off wheel.
Tension setup error: mismatch between outgoing wire diameter and tension weight. If the wire diameter is small but the weight is too heavy, the tension rod lifts at startup and the copper wire cannot withstand the tension and breaks.
Bushing or raw material problems: defects in the bushing itself, such as impurities or weak joints, or damp aluminum rod, can cause irregular breakage even at low startup speed.
Low drawing oil concentration: poor lubrication. Japanese oil concentration should stay at 2.5% to 3.5%. Domestic oil should be 4% to 6%. Too low a concentration easily causes breakage.
Mechanical scratching: damaged openings on tension guide wheels or traverse guide wheels, or burrs on the iron reel edge, can catch and break the wire during operation.
2. Root cause of the take-up machine not stopping
If the take-up machine keeps running after a wire break, the stop signal chain is broken. The problem is in electrical control.
Wire break sensor fault: sensor damage, dirt blocking the sensor, or improper installation position. It cannot correctly detect the break, so no signal is sent.
Control system reception failure: the sensor sends a signal, but loose, shorted, or aged wiring prevents it from reaching the PLC or controller.
PLC program or relay fault: the controller receives the signal, but an internal program error or a damaged relay that executes the stop command prevents the take-up motor power from being cut off.
3. Troubleshooting and solution steps
Check from simple to complex.
First, simulate and test the sensor: with the machine running, manually simulate a wire break and watch whether the take-up machine stops. If it does not stop, the problem is in the sensor or the control loop after it.
Next, check electrical connections: immediately check the wiring from the sensor to the control cabinet for looseness, exposed wire, or short circuits.
Then clean and replace the sensor: clean the sensor probe. If the simulation test still fails, replace it with the same model sensor.
Finally, check the PLC and relay: check on the PLC whether the wire break input signal indicator lights up. If there is an input signal but no output, it is a PLC program or relay problem. Contact a professional electrician for repair.
At the same time, solve the root wire break problem: according to the causes above, check die matching one by one, adjust tension weights, check bushing quality, and check drawing oil concentration. Keeping the wire from breaking is the fundamental fix.
Beyond drawing machines and take-up machines, our precision custom machining capability is not limited to one industry. Hansheng Automation can machine non-standard metal parts for food machinery, medical devices, and printing equipment from customer drawings. We also machine specialized parts for filling machinery and tobacco packaging machinery, as well as yacht components and RC car components. We focus on build-to-print custom machining and produce single pieces or small batches according to customer drawings. We do not sell complete machines.
