What are the common malfunctions of a three-axis thread-rolling machine?

Release Date:

2022-07-04 13:40

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What are the common malfunctions of a three-axis thread-rolling machine?

During operation, three‑axis thread‑rolling machines inevitably encounter certain issues. Therefore, understanding the common malfunctions and corresponding repair procedures is essential for enhancing operational efficiency and extending the equipment’s service life. So, what are the typical faults of a three‑axis thread‑rolling machine?

What are the common malfunctions of a three-axis thread-rolling machine?

1. On the three-axis thread-rolling machine, the yarn neither coils out nor becomes tangled.

Fault: The rolling head is rotating in the wrong direction, and the rolling head’s specifications do not match those of the rebar.

2. The three-axis thread-rolling machine fails to start.

Fault: ( 1) The reverse operation always stops when the power is off, and there is a phase loss. 2) The thermal protector provides protection but may burn out. 3) The wiring has come loose, and the transformer has been damaged.

3. Reversing

Fault: The front limit switch is defective, and the time-delay relay fails to operate.

Troubleshooting methods for a three-axis thread-rolling machine:

( 1) Check whether the limit switches and closing contacts at the rear of the machine are disconnected, and inspect the wiring for looseness, poor contact, damage, or breaks.

( 2) Open the wire, strip the insulation counterclockwise, coil the wire, and unwind it clockwise.

( 3) The sequence for replacing the internal shims of the thread‑rolling wheel is clockwise: thick, medium, thin; and for the outer shim: thin, medium, thick.

( 4) Fine-tune the size. After loosening the six internal screws on the back of the grinding head, use an adjustable wrench to make fine adjustments to the dimensions.

What are the precautions to observe when using a three-axis thread-rolling machine?

1. Before operating the three‑axis thread‑rolling machine, connect the power and grounding cables as required and switch on the power supply. The power supply is a three‑phase 380 V, 50 Hz AC source. To ensure personal safety, an automatic transfer device with leakage‑current protection must be used.

2. Add an adequate amount of water‑soluble coolant to the coolant tank. The three‑axis thread‑rolling machine must use a water‑soluble emulsifiable coolant; oil‑based coolants are strictly prohibited, and ordinary lubricating oil may not be used as a substitute. Do not operate the machine for thread rolling without coolant. Before connecting the three‑axis thread‑rolling machine to the power supply, verify that the coolant pump is functioning properly. Check the electrical system using the control buttons, and confirm that the control system is operating normally. Depending on the diameter of the rebar being processed, replace the thread‑rolling wheel with one that matches the workpiece diameter.

3. Note that the rebar to be processed should be securely clamped in the centering jaws of the three‑axis thread‑rolling machine, with the protruding length aligned with the end face of the peeling blade on the initial‑position rolling head, and then tighten by pulling the handle.

4. The ends of the reinforcing bars to be processed must be flat and cut with a toothless saw. Within a 500 mm length at the end, the surface shall be round and straight; bending is prohibited, and oxy‑acetylene cutting or direct cutting with a cutting machine for finishing is strictly forbidden.

5. When the rib‑stripping cutter on a three‑axis thread‑rolling machine has processed a certain length of rebar, its cutting edge will become dull. At this point, remove the cutter and grind the front cutting edge by 0.2–0.3 mm (do not under any circumstances grind the top surface of the blade). If the rib‑stripping blade develops cracks and can no longer cut properly, replace it with a new blade promptly.

6. During initial cutting, maintain a steady feed rate and avoid rushing to prevent blade cracking. The slides and slide rails of the three‑axis thread‑rolling machine should be cleaned and lubricated regularly. Removed metal chips must be promptly cleared and dried. The coolant tank should be cleaned approximately every two weeks. The gearbox requires periodic lubrication to maintain the specified oil level. In addition, the three‑axis thread‑rolling machine should undergo routine maintenance.

What are the advantages of a three-axis thread-rolling machine?

Precautions for Using a Three-Axis Thread Rolling Machine