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RISHBIN CO., LTD

Analysis of the Causes Affecting the Disc Shear of the Steel Slitting Line

Diameter and thickness of disc cutter:

The diameter of the disc cutter determines the shear angle. The larger the outer diameter, the smaller the shear angle, the smaller the motor power required, and the more energy-saving. But if the diameter is too large, the rigidity of the disc cutter will be weakened and the service life of the disc cutter will be affected. The thickness of the disc cutter determines the strength of the cutter head, but if the cutter head is too thick, it will be very heavy. It is not only hard to operate, but also expensive. At the same time, the thickness of the cutter head is limited when slicing narrow strips. If the cutter head is too thin, the deflection of the cutter is not enough, and the side clearance of the cutter head varies greatly during shearing. Cutting incisions and shapes will change, and the wear of the cutter head will also be faster. As a vulnerable part of disc shear, the machining accuracy and hardness of disc cutter play a very important role in its service life. According to practical experience, the thickness accuracy of disc cutter is 0.005mm, the flatness accuracy is 0.025mm, and the parallelism accuracy of both sides is 0.005mm. In the process of using the disc cutter, the wear and blunt angle of the cutter edge will appear due to the long time of anti-extrusion with the plate, and the metal fatigue layer will appear at the cutting site. To ensure the shear quality, it is necessary to grind the worn cutter disc. The disc cutter plays a very important role in the accuracy of disc shear tape.

Axial backlash of disc cutter:

The reserved size of the axial clearance of the disc cutter should be determined according to the thickness and strength of the shear strip. Generally, the ratio of tear zone to shear zone is about 2:1. According to the color and roughness of shear section, it can be judged whether the side gap is suitable: the section is smooth and shiny, the side gap is too small; the section is lead-gray, the side gap is slightly small; the section is white with lead-gray, the side gap is suitable; the section is white, granular and rough, and the side gap is too big. If the backlash is too large, shear burr will appear. If the backlash is too small, it will lead to too large load of disc shear, serious wear and tear of cutter head, and shorter service life. In the production process, the side clearance values of both sides of the disc cutter should be as consistent as possible. Because the side with large side clearance, the local indentation of the shear will become larger, which is larger than the side with small side clearance, and the shear sickle bending will occur. Especially for the steel plate (narrow strip) with smaller ratio of plate thickness to plate width, the probability of sickle bending is higher.

Coincidence volume

The coincidence is determined by the thickness of the shear strip. Generally, the thickness is positive when the thickness is less than 4 mm and negative when the thickness is more than 4 mm, that is, the blade is in non-overlapping state. Generally speaking, if the overlap is too large, the shear force will increase, and the edge of the strip will bend or even buckle after shearing; if the overlap is too small, the strip will not be able to cut or shear continuously.
Axis accuracy: Axis accuracy includes horizontal swing, vertical swing and axial swing. Usually, the accuracy of horizontal and vertical swing of the tool shaft is required to be within (+0.005mm). The accuracy of axial channeling should be within (+0.005mm). The accuracy of the tool axis plays an important role in achieving the stability of the side clearance of the cutter head and the deviation of the cutter head.