The roller on the coil machine performs a vertical up and down movement through the hydraulic cylinder, where hydraulic oil for sheet metal rolling acts on the piston. It drives the two lower rollers to rotate through the final gear of the main reducer, providing the necessary torque for sheet rolling. The machine rolls flat, plastic metal sheets between its three working rollers (two lower and one upper), utilizing the downward pressure of the upper roller and the rotation of the lower roller to continuously bend the metal sheet multiple times, resulting in permanent plastic deformation. This process forms the required cylindrical, conical, or partial shapes. The drawback of this hydraulic three-roller bending machine is that the sheet ends require pre-bending with other equipment. Suitable for large bending machines with sheet thicknesses over 50mm, the lower part of the two lower rollers features an additional row of fixed support rollers, reducing the span between the lower rollers and thus improving the precision of the rolled workpieces and the overall performance of the machine.

Numerical control rolling machines play a crucial role in the operation process of rolling circles. Thus, users may have doubts about how to operate the equipment for faster and better results during the rolling circle process.

Rolling Method

Primarily involves rolling steel billets into flat circular shapes on the rolling mill.

Mark a line in the middle of the blank material along the length, serving as the control line.

(2) The billets are rolled into two semicircles, and it is not difficult to see that the straight line segments of the flattened circle are precisely the remaining straight edge parts.

When rolling flat round bars, the key is to control misalignment, which requires accurately maintaining the neutral line parallel to the rolling surface. Overrolling is also common during the rolling process, at which point it must be stretched and spot-welded. The post-rolling shape should generally have a slight indentation at the joint, rather than being convex.

2. Correction

The process involves rounding after coiling, which is done after the longitudinal seam of the interface is double-welded and then rounded on the coil machine. Rounding is more difficult and time-consuming than coiling, and the specific method is as follows: (1) First, use the upper rolling mill to repeatedly mix the straight sections of the round coil, alternating between the two straight sections.

(2) Re-roll the entire week's data repeatedly, and the upper mixed pressure, lower quantity, and lifting quantity can be adjusted beforehand.

The reinforcing height of the inner and outer weld seams before rounding should not exceed 1mm; otherwise, it may cause jumping during rounding, which can significantly damage the coil roller.

This method produces cylinders with minimal roundness deviation and ellipticity can be controlled within 83 mm. However, due to the need for two rolling passes, the process is time-consuming and has a relatively lower production rate. Without pre-bent equipment or tools, this method remains a good option for producing cylindrical components individually or in batches, and it significantly saves materials.

The application of this method: The semi-circular diameter after rolling into an oblong shape should be greater than or equal to the smaller diameter that the rolling machine can roll into a cylinder.

What are the process features of the three-roll plate bending machine?

1. High-performance – fully hydraulic drive, automatic welding; 2. Large motor power – main motor with high power and efficiency, fast delivery, versatile applications; 3. High-strength – superior materials, stable structure, safe operation, excellent machine performance; 4. Good safety – durable, long service life, attractive appearance, stable machine performance; 5. Wide applicability – suitable for boiler, chemical, mining, construction, shipbuilding, and other mechanical industries. Through this session's learning, we hope everyone has a more direct understanding of the three-roll bending machine.