Rolling mill and rolling method

Abstract

In a rolling mill in which hydraulic apparatus for controlling the roll balance or the shape of the rolled material are incorporated in movable frames provided separately from roll chocks mounted at each end of the rolls, reducing the roll inclination thereby making it possible to carry out stable rolling, and also reducing the roll vibrations, and making it possible to manufacture products with a high quality. Providing hydraulic apparatus 12 and 13 for controlling the roll balance and the shape of the rolled material inside the movable frames 10 and 11, hydraulic apparatus 16 and 17 that push and restrict the roll chocks 4 and 5 and the movable frames 10 and 11 in the direction of flow of the rolled material relative to the roller stand 3, and the hydraulic apparatus 18 and 19 that push and restrict the movable frames 10 and 11 in the up / down direction relative to the roller stand 3.

Description

[0001] 1. FIELD OF THE INVENTION[0002] The present invention relates to rolling mills and rolling methods, and in particular to, a rolling mill configured so that the rolls can be moved in the direction of the axis of the rolls depending on the width of the material to be rolled, and with a hydraulic apparatus for carrying out control of the roll balance or of the shape of the rolled material being incorporated in a movable frame provided separately from the roll chocks installed at each end of the rolls, and so that said movable frame can be moved in the direction of the roll axis along with the rolls and the roll chock.[0003] 2. DESCRIPTION OF PRIOR ART[0004] Rolling mills for sheet materials are generally constructed so that the rolls can be moved in the direction of the roll axis in order to adjust the position of the rolls in the axial direction depending on the width of the material to be rolled. In such a rolling mill, in the one described in Japanese patent disclosure No. Sh...

AI Technical Summary

Benefits of technology

[0011] In this manner, by providing the second hydraulic apparatus and pushing and restricting the roll chock and movable frame in the direction of flow of the rolled material, it is possible to make zero the gaps between the roll chock, movable frame, and rolling mill housing, to reduce the roll inclination during rolling, and carry out stable rolling with small meandering movement of the rolled material and with few failures of biting of the material.

[0014] Because of this, when being pushed by the second hydraulic apparatus, the friction force between the movable frame and the roll chock increases, and the action of restricting the roll stock in the up / down direction becomes stronger due to pushing and restricting the movable frame in the up / down direction, thereby making it possible to reduce further the vibrations due to resonance.

[0016] Because of this, during rolling, as has been described in (1) above, the gap is eliminated, even the inclination of the roll axis is eliminated, and even the rolling is made stable. In addition, even the vibrations are reduced because the roll chock is restricted in the direction of flow of the rolled material and in the up / down direction.

[0018] Because of this, the pushing force of the second hydraulic apparatus is weakened when the vibrations are small, and the function of controlling the roll balance or the shape of the rolled material by the first hydraulic apparatus is effectively utilized, and the pushing force of the second hydraulic apparatus is increased only when the vibrations due to resonance become a problem, and the roll chock is restricted in the up / down direction by increasing the friction force between the movable frame and the roll chock, thereby reducing the vibrations due to resonance.

Problems solved by technology

Although these gaps are useful for their intended purpose at the time of adjusting the position of the roll in the axial direction or at the time of roll replacement, they will have detrimental effect at the time of rolling the material to be rolled, that is, the roll chocks installed at the ends of the rolls will move due to these gaps, and the rolls become inclined relative to the material being rolled, thereby causing meandering movement of the rolled material or failure of biting of the material at the rolling mill.

These rollers revolve around the roller axis, and during rolling, vibrate the rolling mill at a frequency of vibration proportional to the number of times the rollers pass per unit time, and if this frequency of vibration unluckily becomes equal to natural frequencies of the rolling mill, there will be resonance which further gets amplified by said gaps, and may even cause chattering marks on the rolled material.

However, if the roll chock and the movable frame are merely pushed in the direction of rolling, when vibration of the rolls and the roll chocks occurs due to resonance, the effect of the pushing force on the roll chock and the movable frame gets weakened, and hence it will not be possible to prevent the vibrations.

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