JPH0787935B2 - Roll bending control mechanism of rolling mill - Google Patents

Description

TECHNICAL FIELD The present invention relates to a roll bending control mechanism for a rolling mill.

[Conventional technology]

When rolling a steel strip, controlling the thickness in the width direction to form a flat plate is an important problem during rolling. FIG. 3 is a roll bending control mechanism of a conventional rolling mill.
FIG. 4 is a schematic diagram showing an example of a work roll bending curve of a conventional rolling mill at the position of the work roll. As shown in Figure 3, the principle of roll bending is
When rolling with a predetermined rolling force, a force is applied between the upper roll housing and the lower roll housing by a hydraulic jack, and this force causes the upper work roll 1 to project downward and the lower work roll 2 to move upward. It consists of a convex bend.
4 is an upper backup roll and 5 is a lower backup roll.

Such a conventional rolling mill is provided with a mechanism in which a moment arm by roll bending with respect to the center point of the steel strip (rolled material) 3 changes as the roll is shifted, and the same hydraulic pressure is applied to both ends of the upper and lower housings. A control mechanism for controlling the bending pressure of the upper and lower work rolls is provided.

[Problems to be Solved by the Invention]

However, the conventional roll bending control mechanism has the following problems.

As described above, by applying a force to the both ends of the upper and lower work rolls 1 and 2 with a hydraulic jack between the upper roll housing and the lower roll housing, the oil is supplied from the hydraulic source 6 via the same servo valve 7. Since pressure acts, as shown in FIG. 4, during rolling of the steel strip 3, the line symmetry of the rolled material center line (= housing center line) is broken (not line symmetric), and the rolled material center point is point symmetric. Becomes In the actual rolling state, the load conditions of the upper and lower work rolls are not the same, wear of the rolls and difference in thermal expansion occur, and point symmetry cannot be maintained. As a result, the shape of the steel strip 3 is not flat, and strain etc. Of the steel strip, defective strip passing, etc., and particularly the tail end shape of the steel strip is affected.

Therefore, the present invention has been made to solve the above-mentioned problems, and in consideration of the rolling pressure and its distribution, the bending curve of the work roll during rolling is always controlled symmetrically with respect to the center line of the rolling mill. An object of the present invention is to provide a roll bending control mechanism for a rolling mill.

[Means for Solving the Problems]

In order to achieve the above-mentioned object, in the present invention, in a bending control mechanism of a rolling mill, which adjusts the bending amount of the work roll by applying pressure to both ends of the upper work roll and both ends of the lower work roll, The same bending pressure is applied to one end side of the work roll and the other end side of the lower work roll, while the same bending pressure is applied to the other end side of the upper work roll and one end side of the lower work roll. Since each of the upper and lower work rolls has a pressure control mechanism, the bending moment of the work roll bending pressure can be individually controlled so as to act symmetrically with respect to the rolling mill center line. It is characterized in that it is possible to control the deflection of the wire in line symmetry with respect to the center line of the rolling mill. Than it is.

[Action]

The bending pressure of the work rolls is configured so that the pressure symmetry can be controlled individually for each pair of point symmetric parts with respect to the center line of the rolling mill. Can be axisymmetric with respect to.

〔Example〕

Next, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a system diagram showing an embodiment of a roll bending control mechanism of the present invention, and FIG. 2 is a schematic view showing a work roll bending curve at the position of the work roll.

As shown in the drawings, in the hydraulic mechanism of the present invention, a force is applied between an upper roll housing and a lower roll housing (not shown) by a hydraulic jack (not shown), and this force causes the upper work roll 1 to move. The lower work roll 2 is bent downward, and the lower work roll 2 is bent upward, and is configured by two hydraulic systems from the hydraulic source 6. The system 1 (hereinafter referred to as "system A") is configured to apply hydraulic pressure to one end side 1a of the upper work roll 1 and the other end side 2b of the lower work roll 2 by a pipe 8a via a servo valve 7a. ing.
The other system (hereinafter referred to as "B system") is the servo valve 7b.
The other end side 1b of the upper work roll 1 by the pipe 8b through the
Also, the hydraulic pressure is applied to one end side 2a of the lower work roll 2.

In this way, the hydraulic pressure is set to two systems, and bending pressures of the same hydraulic pressure (that is, the same pressure for 1a and 2b, the same pressure for 1b and 2a) are applied at point symmetrical positions with respect to the center point of the rolled material 3, and As shown in FIG. 2, the bending curve of the work roll during rolling is always controlled symmetrically with respect to the center line of the rolling mill by changing the respective pressures according to the shift amount, the roll diameter, and the material.

〔The invention's effect〕

As described above, according to the present invention, the bending curve of the work roll during rolling can be always controlled to be line symmetrical with respect to the center line of the rolling mill, and the tail end shape of the steel strip is not adversely affected. It is possible to bring about useful effects such as shape defects such as distortion of the strip, defective strip passing, etc., and flattening of the shape of the rolled steel strip.

[Brief description of drawings]

FIG. 1 is a system diagram showing an embodiment of a roll bending control mechanism of the present invention, FIG. 2 is a schematic diagram showing a work roll bending curve at the position of a work roll, and FIG. 3 is a roll bending control of a conventional rolling mill. FIG. 4 is a system diagram showing an example of the mechanism, and FIG. 4 is a schematic diagram showing a work roll bending curve of a conventional rolling mill at the position of the work roll. In the drawing, 1 ... upper work roll 2 ... lower work roll 3 ... steel strip 4 ... upper backup roll 5 ... lower backup roll 6 ... hydraulic pressure source 7, 7a, 7b ... servo valve 8a, 8b ... …Piping.

Claims (1)

[Claims] 1. A bending control mechanism of a rolling mill, wherein a bending amount of a work roll is adjusted by applying pressure to both ends of an upper work roll and both ends of a lower work roll. The same bending pressure is applied to the other end side of the lower work roll, while the same bending pressure is applied to the other end side of the upper work roll and the one end side of the lower work roll. By having
The bending moment due to the bending pressure of the work roll is configured to act in line symmetry with respect to the rolling mill center line, so that the deflection of the upper and lower work rolls can be controlled in line symmetry with respect to the rolling mill center line. Roll bending control mechanism.