JPS62275504A - Rolling mill - Google Patents

Abstract

PURPOSE:To prevent the generation of sheet breakage and to roll a material to a flat sectional shape by disposing upper and lower tension rolls in proximity to work rolls to at least either of the inlet side or outlet side of a multi-stage rolling mill and varying the rotating speed and deflection thereof. CONSTITUTION:While the upper and lower tension rolls 5, 6 are kept applied with a decrease deflection by divided press rolls 8-10, said rolls are driven at the speed lower than the speed of the upper and lower work rolls 1, 2 by a motor 14. Since the rolling material 12 is held lightly rolled down by screw- down cylinders 7 by the tension rolls 5, 6, both ends in the transverse direction is elongated larger than in the central part. The transverse distribution of the tension is, therefore, larger in the central part T2 and smaller at the ends T2', T2''. The central part where the tension is large is mainly rolled and elongated. The sectional shape in the transverse direction of the rolling material 12 rolled by the work rolls 1, 2 is made into the flat shape if there is a tendency to edge waving. Since the tension distribution of the rolling material is smaller at the transverse ends than in the central part, the generation of a crack from the transverse ends is obviated.

Description

[Detailed Description of the Invention] 3. Detailed Description of the Invention [Field of Industrial Application] The present invention improves the cross-sectional profile by imparting tension distribution in the width direction to the rolled material rolled by work rolls. This relates to rolling mills.

[Prior Art] When rolling a material to be rolled such as a thin steel plate, a rolling load is applied to the material under tension using, for example, a four-high rolling mill or a winding mill.

However, shape defects such as edge drop, plate crown, mid-elongation, and edge elongation may occur in the rolled material.

In order to prevent these shape defects, conventionally the work roll is bent in various directions using a bending device such as a hydraulic cylinder to control the cross-sectional shape of the rolled material.

[Problems to be solved by the invention] However, when controlling the cross-sectional shape using a bending device, etc.,
”- minute shape control is not performed.

In addition, in the case of thin plate rolling, if the tension is too high, cracks may occur at the edge of the plate, and the tension applied to the rolled material is also applied to the edge of the plate, causing the fracture to expand or break the plate. .

Further, if the material to be rolled is rolled without applying tension, narrowing is likely to occur.

[Means for Solving the Problems] In order to solve the above-mentioned conventional problems, the present invention provides at least one of the entry side and exit side of the multi-high rolling mill.
Upper and lower tension control rolls are arranged close to the work rolls of the multi-high rolling mill at variable rotation speeds, and upper and lower presser rolls are arranged to apply bending to the upper and lower tension rolls, or A rolling mill was constructed by installing a roll crown variable device or at least one of them.

[Function] By making the rotational speed of the upper and lower tension rolls different from the rotational speed of the work rolls of the multi-stage rolling mill, the overall tension applied to the material to be rolled can be greatly changed.

Furthermore, by rolling in combination with the direction and amount of deflection applied by the upper and lower rolls of the tension roll and the direction and star of deflection of the work roll of the multi-high rolling mill, the distribution of the tension applied to the material to be rolled can be adjusted in the width direction. can be changed to

Thereby, the cross-sectional profile of the material to be rolled can be improved.

[Example] Embodiments of the present invention will be described below with reference to the drawings.

FIGS. 1 to 3 show an embodiment of the present invention, which is a four-stage structure consisting of upper and lower work rolls 1 and 2, and upper and lower restraint rolls 3.4, which are capable of imparting flexure to the upper and lower work rolls 1 and 2. Upper and lower tension rolls 5 and 6 are disposed on the entry side of the rolling mill 16 so as to be able to be rolled down by a reduction cylinder 7 or a jack, and a divided presser roll 8 is provided to impart deflection to the tension rolls 5 and 6.
, 9 and 10 are arranged so that the pressing force can be varied by a cylinder 11 or a jack. In the figure, 12 is a material to be rolled, 13 is a motor for driving a work roll, and 14 is a motor for driving a tension roll.

With the configuration as described above, various controls such as those described below can be performed.

Presser roll divided into upper and lower tension rolls 5.6 8.10
The upper and lower tension rolls 5 and 6 are moved to a four-high rolling mill 17 by a motor 14 while the upper and lower tension rolls 5 and 6 are decremented by
When driven at a speed slower than the speed of the upper and lower work rolls 1 and 2, a tension T2 is generated in the material to be rolled 12 between the tension roll 5.6 and the work rolls 1 and 2, but the material to be rolled 12 is Since the tension rolls 5 and 6 having decrease flexure are lightly rolled down by several percent by the reduction cylinder 7, both ends in the width direction have a larger elongation than the center part.

Therefore, the distribution of the tension in the width direction is large in the center part T2, and small in the end parts T2' and T2'', and the upper and lower work rolls 1
, 2 gives an increase deflection and is lowered,
The central part, where the tension is high, is mainly rolled and elongated. Since the tension at the width end portion of the material to be rolled 12 is relatively small, the elongation caused by the work rolls 1 and 2 is small. Therefore, when the tendency of edge elongation occurs, the cross-sectional shape in the width direction of the material to be rolled 12 rolled by the work rolls 1 and 2 becomes flat.

Furthermore, since the widthwise tension distribution of the material to be rolled is smaller at the width ends than at the center, even if the tension value at the center is set higher than before, cracks will not occur from the width ends and sheet breakage will not occur.

In addition, when the middle elongation occurs, the tension roll 5,
While giving increase deflection to 6, work roll 1,
When decrease flexure is applied to the material 2 and rolled, the tension at both ends becomes relatively large, and both ends are mainly elongated, with no elongation occurring in the middle.

Because the distance between the upper and lower tension rolls 5 and 6 and the upper and lower work rolls 1.2 is small, the material to be rolled 12 may buckle. This can be done by applying tension to the necessary portions of the material and rolling the material under conditions of low tension, O tension, or negative tension without buckling or drawing. For example, in the case of a thin plate, applying a slight tension to the edges will prevent squeezing, and reducing the overall tension and the center will cause the material to stretch in the width direction, making it easier for the mechanical crown of the work roll to be transferred to the material. This improves the cross-sectional profile of the material to be rolled and prevents elongation and elongation.

It should be noted that the rolling mill of the present invention is not limited to the above-mentioned embodiments; the tension rolls may be installed on the exit side of the rolling stand, and the tension rolls may be installed on the entry side and the exit side of the rolling stand. The deflection of the tension roll and the work roll can be obtained by various combinations. The presser roll may be an integral type or a separate type may be provided. The crown of the tension roll may be It goes without saying that various modifications may be made without departing from the spirit of the present invention, such as being able to vary it by operating the taper piston by pressure or hydraulic pressure.

[Effects of the Invention] As explained above, the rolling hall of the present invention exhibits various excellent effects as described below.

(D) By maximizing the speed and deflection of the tension roll, the tension at the width edges can be held down to the conventional level, while the tension at the center can be increased to a value higher than before, resulting in a flat cross-sectional shape without causing board breakage. It can be rolled into

(n) Since the tension roll is disposed close to the work roll and the speed and deflection range are variable, it is possible to roll with low tension, partial O tension, and negative tension without buckling or squeezing.

(IID (IXII)) adjusts the tension distribution in the width direction of the material to be rolled, adjusts the plastic flow conditions in the width direction of the material, improves the transfer of the crown profile of the work roll onto the material, and improves the cross-sectional profile of the material. and the plate shape can be improved.

[Brief explanation of drawings]

Fig. 1 is an explanatory diagram of one embodiment of the rolling mill of the present invention, Fig. 2 is a view taken in the direction of arrows I-II in Fig. 1, and Fig. 3 is an illustration of ■-■ in Fig. 1.
This is a directional view. 1.2 is a work roll, 5 and 6 are tension rolls, 7 is a reduction cylinder, 8.9.10 is a divided presser roll, and 11 is a cylinder.

Claims (1)

[Claims] 1) Upper and lower tension rolls are disposed on at least one of the entry side and the exit side of the multi-high rolling mill in close proximity to the work rolls of the multi-high rolling mill at variable rotation speeds, and various crown effects are applied to the upper and lower tension rolls. A rolling mill characterized in that it is equipped with a device for imparting.