JPH0465724B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method for controlling the shape of a 12- or 20-high cluster type multi-high rolling mill.

(Prior art) Conventionally, a 12-stage or
In a 20-high cluster type multi-high rolling mill, one end of the intermediate roll that supports the work roll is tapered to move it in the width direction of the material to be rolled, or the back-up roll is divided into multiple pieces in the width direction. By adjusting the individual displacement amounts, the shape of the rolled material is controlled.

However, since the work roll has a small diameter, the deflection pattern of the work roll is complicated, and in order to obtain a rolled material with a good shape, depending on the type of the rolled material,
The problem is that the shape of the intermediate roll needs to be optimized.

Further, the thermal crown of the work roll changes during rolling, and in the case of a small-diameter work roll, this change is particularly severe, and the thermal crown rapidly increases during acceleration immediately after the start of rolling. Therefore, in order to follow this change, as mentioned above, the intermediate roll is moved (the former) and the crown is adjusted by the back-up roll (the latter), but in the former, the movement speed is slow at low speeds, There is a problem in that the distance needs to be increased, and in the latter case, there is a problem in that there is a limit to local shape correction.

For example, a conventional general 20-high cluster rolling mill, that is, a rolling mill that has a small-diameter work roll and an intermediate roll that is movable in the width direction of the material to be rolled and that is tapered near the end. The results of rolling using this method are shown below.

Figure 5 shows an example of the plate shape of a rolled material when a copper alloy thin plate is rolled at a low speed. The horizontal axis shows the distance Z (mm) from the center of the plate width, and the vertical axis shows the elongation rate. ε is taken, the plate width of the rolled material b = 620 mm, the input side plate thickness h1 = 0.7 mm, the exit side plate thickness h2 = 0.5 mm, the rolling speed v =
The speed is 10m/min. As shown in the figure, in this case, the occurrence of thermal crown on the work roll is negligible and the plate shape of the rolled material is also good.

However, as shown in FIG. 6, if the rolling speed continues to be accelerated to reach v=200 m/min, the elongation in the middle becomes noticeable due to the thermal crown, and rolling becomes impossible.

To deal with this, it is necessary to move the position of the intermediate roll to an optimal value according to the thermal crown, but during low-speed rolling, it is impossible to move because of scratches between the rolls, and the moving distance is also quite long. Since long distances are required, there is a limit to the control range for various conditions.

In addition, Fig. 6 shows rolling speed v of 10 m/min.
It is the same as Figure 5 except that the speed is 200m/min.

On the other hand, an asymmetrical six-high rolling mill that combines small-diameter work rolls and large-diameter work rolls is known in which a bending force is applied to the intermediate roll in the horizontal direction (Japanese Patent Laid-Open No. 148460/1983). .

However, in this rolling mill, as shown in FIGS. 7 and 8, it is necessary to apply bending force to the intermediate roll 3a to cause bending to the center of the intermediate roll 3a (center in the sheet width direction). , the diameter of the intermediate roll 3a must be relatively large. Therefore, the bending force also increases. Further, even if the width of the rolled material 1 changes, only a fixed bending and deflection form is provided, resulting in poor controllability. This also applies to cluster type six-high rolling mills.

Further, the intermediate roll 3a is in contact with the backup roll over its entire length. For this reason, bending is difficult to occur due to the restraint of the outer back-up rolls, and a large bending force is required, which poses a problem in that it shortens the life of the bearings (not shown) that support both ends of the intermediate roll 3a. .

(Object of the Invention) The present invention has been made in view of the above-mentioned conventional problems.The purpose of the present invention is to achieve a fast response speed with a small bending force and a shape with good precision without increasing the diameter of the intermediate roll. An object of the present invention is to provide a shape control method for a multi-high rolling mill that enables rolling.

(Structure of the Invention) In order to achieve the above object, the present invention includes a pair of upper and lower work rolls, and a set of two rolls is provided behind each work roll so as to be in contact with the work rolls. One end of the intermediate roll of a 12-high or 20-high cluster type rolling mill is formed into a tapered shape or a curved outer shape with a smaller diameter than the center of the roll, and a horizontal bending force is applied to one end of the intermediate roll. was added to adjust the amount of vertical deflection of the work roll.

(Example) Fig. 1 and Fig. 2 show a cluster type 20-high rolling mill to which the method according to the present invention is applied, in which a pair of work rolls 2 are placed above and below with a material to be rolled 1 in between, and each work roll 2 A set of two first intermediate rolls 3 are provided behind the work rolls 2 in contact with the work rolls 2. Further, behind the first intermediate roll 3, there are second intermediate rolls 4, three on the top and bottom, and further behind this, there are first backup rolls 5, four on the top and bottom.
It is provided in contact with the intermediate roll 3 or the second intermediate roll 4.

Among these, a tapered portion 6 formed in a tapered shape is provided at the opposite ends of the upper and lower first intermediate rolls 3, and a bending force is applied to the tapered portion 6 in the horizontal direction by a hydraulic cylinder or the like (not shown). It is becoming more and more popular. This bending force can be applied in either the direction in which the tapered portions 6 of the pair of first intermediate rolls 3 approach each other or in the direction in which they separate.
As a result, the shape of the first intermediate roll 3, particularly the tapered portion 6, which is in contact with the work roll 2 is changed to adjust the deflection form of the work roll 2.

The shape control method according to the present invention applies a horizontal bending force (arrow A )
By adding this, the shape of the material to be rolled 1 is controlled by adjusting the deflection form of the work roll 2.

Next, the results of actual rolling by applying the method according to the present invention to the above-mentioned rolling mill will be shown.

Figure 4 shows the plate shape of the rolled material when a copper alloy thin plate was rolled under the same conditions as in Figure 6 using the above 20-high rolling mill, and the horizontal and vertical axes are also the same as in Figure 6. It's the same. That is, in an example in which the method according to the present invention is applied when a thermal crown similar to that shown in FIG. This shows that a good shape can be obtained even if it remains fixed. Moreover, in this method, the first intermediate roll 3
Since there is no need to move the bending force, the response speed of the bending force is sufficiently high and there is no restriction as in the case of the movement of the conventional intermediate roll.

In addition, although the above embodiment describes a 20-high cluster type rolling mill, the present invention is not limited to this, and can also be applied to a 12-high rolling mill of the same type. However, behind the pair of upper and lower work rolls, there is an intermediate roll that is made of two rolls and has one end formed in a tapered shape or a curved outer shape with a smaller diameter than the center of the roll, and this one end has a horizontal direction. The condition is that it can provide a bending force of .

Otherwise, due to the restraint of the back-up roll behind the intermediate roll, the bending effect of the intermediate roll will be small and a large bending force will be required, making it difficult to apply from the viewpoint of the bearing life of the intermediate roll. be.

Furthermore, in the above embodiment, the movement of the first intermediate roll 3 in the width direction of the rolled material sheet was not taken into consideration;
The above-mentioned bending force and this movement, for example, movement of the upper and lower intermediate rolls in mutually opposite directions, may be applied in combination as appropriate, thereby making it easier to respond to various sheet width shape controls.

(Effects of the Invention) As is clear from the above description, according to the present invention, a pair of upper and lower work rolls is formed into a set, and a set is placed behind each work roll in contact with the work rolls. One end of the intermediate roll of a 12-high or 20-high cluster type rolling mill having two intermediate rolls is formed into a tapered shape or a curved outer shape with a smaller diameter than the center of the roll. A bending force is applied to adjust the amount of vertical deflection of the work roll.

For this reason, it is now possible to adjust the deflection form of the work roll even when the position of the intermediate roll is fixed, and as shown in the rolling results above, it is possible to obtain a rolled material with a good shape. In addition, the response speed of the bending force is sufficiently high, and shape control with good response speed is possible.

Furthermore, since the tapered part is bent, there is no need for the intermediate roll to have a large diameter, and since this part does not come into contact with the back-up roll, etc., it is possible to control the shape with a small force. This has the effect of making it possible.

[Brief explanation of the drawing]

Fig. 1 is a roll arrangement diagram of a cluster type 20-high rolling mill to which the method according to the present invention is applied, Fig. 2 is a sectional view taken along the - line in Fig. 1, and Fig. 3 is a work roll and first intermediate roll section. , FIG. 4 is a diagram showing the rolling results by the method according to the present invention, FIGS. 5 and 6 are diagrams showing the rolling results by the conventional method, and FIG. 7 is a diagram showing the rolling results by the conventional method.
8 are diagrams showing the state of bending and deflection of the intermediate roll of a conventional rolling mill. 2... Work roll, 3... First intermediate roll,
6...Tapered part.

Claims (1)

[Claims] 1. An intermediate part of a 12-high or 20-high cluster type rolling mill that has a pair of upper and lower work rolls and a set of two intermediate rolls installed behind and in contact with each work roll. One end of the roll is formed into a tapered shape or a curved outer shape with a smaller diameter than the center of the roll, and a horizontal bending force is applied to one end of this intermediate roll to adjust the amount of vertical deflection of the work roll. A method for controlling the shape of a multi-high rolling mill, characterized by performing the following steps.