In mechanical processing, rolling processing is often used to improve the surface hardness, fatigue resistance and wear resistance of the workpiece, reduce the surface roughness of the workpiece, and extend the service life of the workpiece. At the same time, during the rolling process, the metal can be plastically deformed under the action of external force to change the internal stress to straighten the shaft and rod workpieces with better rigidity.
In the process of rolling the workpiece, the rolled workpiece bends due to the uneven hardness of the surface layer under the action of external force. At a high point in the center of rotation of the bend, the rolling pressure is large, and the plastic deformation is also large, which makes the bending degree of the workpiece more increased. This phenomenon is particularly prominent when using rigid rolling tools.
The method of rolling straightening is to check the radial runout of the workpiece after the first rolling of the workpiece, mark the concave part, and adjust the concave part of the workpiece to the height of the center of rotation of the machine tool with a four-jaw chuck. It is proportional to the bending size of the workpiece, and then the second rolling is performed, and then the workpiece is corrected with a dial gauge and the jaws of the four-jaw chuck. Then use a dial indicator to check the bending condition. If it still bends, adjust the workpiece using the above method and perform the third rolling until the required straightness of the workpiece is reached. The length of the knife passed after the second time should be according to the specific situation, and it is not necessary to go through the whole process, and the reverse knife should be used.
Roll straightening is used, which is usually completed in the process of rolling the workpiece, which not only does not damage the surface of the workpiece, but also makes the outer surface of the workpiece more uniformly rolled, does not cause dead bends, and is easy to operate.
