JPH0571322B2 - - Google Patents

Description

[Detailed Description of the Invention] <Industrial Application Field> The disclosed technology belongs to the field of technology for rolling steel plates and the like.

<Summary of the gist> The invention of this application is such that a pair of rolls such as work rolls installed in a mill stand used for rolling steel plates, etc. have the same barrel length, and each roll has an initial crown of S. This invention relates to a rolling roll having a shape that complements each other in the axial direction, and a rolling method using the rolling roll, and in particular, the initial crown of each of a pair of work rolls, etc. The initial crowns of the lower surface of the upper roll and the upper surface of the lower roll of the pair of rolls are formed from a cubic function curve having the following terms, and one of the initial crowns is a part of the cubic function curve. , Rolling in which both the upper and lower rolls are formed by a curve that is a cubic function curve that is relatively translated in the axial direction so that the other side is formed by a part of the side where the outer diameter of the roll is smaller than this curve. This invention relates to a roll and a rolling method.

<Prior Art> As is well known, the demand for rolled materials such as steel plates is increasing due to the rise of the automobile industry, etc., and the rolls of so-called mill stands for rolling steel plates are required to have various performances. There is.

Therefore, the thickness of the rolled material rolled by the work rolls and other rolls installed on the mill stand has been made to be precisely uniform in the longitudinal direction of the strip. Various techniques have been devised and developed to obtain uniform precision in the thickness of the plate in the width direction, but none have yet been found to be fully satisfactory.

Therefore, in the rolling process of rolled material, although it is desired that the plate thickness in the width direction has a flat plate crown, in the rolling process, under normal rolling conditions, a pair of work rolls, etc. Bending and deflection of the upper and lower rolls occur depending on the difference in force and the difference in sheet width, and as a result, the sheet crown generally tends to be deformed into a convex shape.

That is, in the actual rolling process, the lower surface of the upper roll and the upper surface of the lower roll have opposite quadratic coefficients due to vertical bending and deflection of the rolling rolls such as a pair of upper and lower work rolls, and the barrel It can be seen that the quadratic component with respect to the length is dominant.

In order to correct the convex plate crown due to bending, deflection, etc. of the upper and lower rolls during the rolling process using the upper and lower rolls of the initial crown, the rolling rolls are equipped with a function to correct the plate crown to a concave shape as a means for suppressing the shape of the plate crown. I have come to realize that it is necessary.

<Problem to be solved by the invention> As a technique in line with this, for example, JP-A-56-
A pair of rolls as shown in the invention of No. 30014, for example, a work roll is provided with an S-shaped initial crown, and these rolls (so-called
The plate crown of the rolled material during rolling is controlled by relatively moving the CVC rolls in the longitudinal direction.

In the known conventional technology, the initial crowns of the upper and lower rolls are given by a similar quadratic function that is point symmetrical to each other, and therefore, only the first-order component of the plate crown can be corrected. figure,
The plate crown can only be corrected from a diamond shape to an inverted diamond shape, and if you try to eliminate variations caused by bending, deflection, etc. during roll rolling, uncorrected portions will remain in the so-called 1/4 section, resulting in hot strips, etc. The shape of the plate crown, which is made of a secondary component of the rolled material, is not controlled in accordance with the actual rolling process, and as a result, a wavy phenomenon occurs in the 1/4 section.

In addition, as mentioned above, the plate crown during rolling generally tends to have a convex shape, and therefore the shape restraint function requires modification towards a concave shape. On the contrary, if the plate crown moves from the neutral position by the same amount to the left and right, the plate crown will have the ability to correct from the flat shape to the convex side and the concave side. This means that it also has a completely unnecessary correction function for the convex shape, and has the disadvantage that it goes against the concave plate crown suppression function due to the flat upper limit.

As a result, there was a problem in that the amount of correction of the pair of upper and lower rolls to the convex plate crown was small in absolute terms.

<Objective of the Invention> The object of the invention of this application is to solve the technical problem of the insufficient amount of correction by a pair of upper and lower rolls on a convex plate crown based on the above-mentioned prior art, and to solve the problem that is generally considered unnecessary. Omitting the correction function from a flat type to a convex type, and adding an initial crown to a pair of rolls that has a secondary component to eliminate bending, deflection, etc. of the upper and lower roll pair in accordance with actual rolling, 1/ Prevent compound elongation such as elongation of 4 parts from occurring,
An excellent rolling roll that can correct the crown from a flat plate crown to a concave plate crown according to the design, thereby benefiting the field of processing technology in the metal product manufacturing industry, and a rolling method using the rolling roll. This is what we intend to provide.

<Means/effects for solving the problem> In order to solve the above-mentioned problem, the structure of the invention of this application, which is summarized in the above-mentioned claims, is provided in a mill stand, etc. for rolling steel plates, etc. The initial crowns of a pair of rolls, such as work rolls, are formed by a cubic function curve having a quadratic term or less. is a part of the cubic function curve, and for the other initial crown, set the cubic function curve as the axis so that the initial crown is at the position on the side where the outer diameter of the roll is smaller than the curved part of the one roll. These initial crowns are formed by curves that are relatively translated in parallel in the direction, and the amount of relative translation is determined by changes in rolling conditions such as the thickness and width of the rolled material to create a convex shape of the plate crown. This technology has been implemented by cutting off the correction ability of unnecessary portions, making it possible to greatly control the plate crown from flat type to concave type, and making it possible to perform rolling according to the settings.

<Embodiments> Next, embodiments of the invention of this application will be described below with reference to the drawings.

First, to explain the principle aspect of the invention of this application with reference to FIG. 2, in the orthogonal coordinate system of the x-axis and y-axis, y=ax ³ (1) This is a reference cubic function (standard form) that determines the initial crown of each pair of upper and lower rolls, and the initial crown of the roll is determined by its curve.

In Fig. 2, for example, for the initial crown forming the lower surface of the upper roll of the work roll, the center of the roll barrel (half the length of the barrel) is located at a position displaced by _b1 in the x-axis direction. and the initial crown that determines the upper surface of the lower roll has the center of the roll barrel at a position displaced by b ₂ in the x-axis direction. The function is in standard form and the center of the roll barrel (center of the mill stand)
Expressing the curve _{of each} initial crown in terms of the barrel length ^Z and height _y from The initial crown of can be expressed as y ₂ =a(z+b ₂ ) ³ +c ₂ (3).

In this way, as shown in FIG. 3, the upper roll roll 1 and the lower roll roll 2 are arranged vertically opposite each other with their initial crowns 3 and 3' forming roll contours, and the work roll is roll 1,2
A roll gap 4 is formed as a roll gap 4 to apply a rolling action to the rolled material 5.

In this case, the plate crown of the rolled material 5 is subjected to bending, deflection, etc. during rolling of the rolls 1 and 2, but as shown in FIG. 3, basically the difference in the roll contours For Δy, Δy=y ₁ −y ₂ =a[(z+b ₁ ) ³ −(z+b ₂ ) ³ ]+(c
₁
−c ₂ )=a[3(b ₁ −b ₂ z) ² +3(b ₁ ² −b ₂ ² )z+b ₁ ³
−b ₂ ³ ]+(c ₁ −c ₂ ) (4)

Therefore, looking at the equation (4), the cubic term is eliminated and a quadratic equation regarding the barrel length Z is expressed, and the roll profile difference Δy between the upper roll 1 and the lower roll 2 is It is expressed by the following formula, that is, the rolled material 5 is formed into a convex shape due to bending, deflection, etc. of the rolls 1 and 2 during actual rolling, and the plate is a quadratic function that matches the mathematical analysis. You can see that the crown thickness is represented, and by controlling this,
It is possible to perform control so that the convex plate crown of the rolled material 5 due to bending, deflection, etc. of the upper roll 1 and lower roll 2 during rolling can be eliminated (it is made into a concave plate crown). Recognize.

Here, as mentioned above, convex crown deformation occurs in the plate crown due to bending, deflection, etc. in the upper and lower rolls 1 and 2, but in contrast, when the upper and lower rolls 1 and 2 are Plate crown control is performed by a fixed amount of relative movement.

That is, as shown in Fig. 4, the upper roll 1 is moved e ₁ parallel to the Z axis, and the lower roll 2 is
When e ₂ is translated in parallel, the initial crowns 3, 3' of the translated upper roll 1' and lower roll 2' are
The formulas for y ₁ ′ and y ₂ ′ are y ₁ ′=a[(z−e ₁ )+b ₁ ] ³ +c ₁ (5) y ₂ ′=a[(z−e ₂ )+b ₂ ] ³ +c ₂ (6) where the translated upper roll 1′
^The _{difference Δy} ′ between _{the roll} contours _of
+
b ₂ ) ³ ]+c ₁ −c ₂ =a[3{(b ₁ −e ₁ )−(b ₂ −e ₂ )}z
²⁺
3 {(b ₁ −e ₁ ) ² −(b ₂ −e ₂ ) ² }z+(b ₁ −e ₁ ) ³ −(b
₂ −
e ₂ ) ³ ]+(c ₁ −c ₂ ) (7) By selecting each a, b, c, and e, the role can be changed as shown in equation (7) above. A straightening action can be applied during rolling so that the coefficient of the quadratic term of the plate crown due to the difference in contour Δy′ can be changed arbitrarily, and therefore the barrel length direction of the upper roll 1 and lower roll 2 By the relative parallel movement to , it becomes possible to control the plate crown of the rolled material 5 from a flat shape to a concave shape in a stepless manner.

It goes without saying that the embodiments of the invention of this application are not limited to the above-mentioned embodiments. For example, appropriate selection of constants for the quadratic term, first-order term, and zero-order term of the cubic function depends on the material of the rolled material. Various modes can be adopted that can be selected as appropriate depending on the shape, width size, etc.

It goes without saying that the applicable rolls are not only work rolls, but also intermediate rolls and backup rolls.

<Effects of the Invention> Hereinafter, according to the invention of this application, in a roll such as a pair of upper and lower work rolls that are basically installed in a mill stand and perform a rolling action on a rolled material such as a steel plate, The initial crown of the roll is given by a cubic function curve, and the initial crown on one side of the upper roll and the lower roll is formed by a part of the cubic function curve that gives this, and the initial crown of the other roll is By using a part of the side where the roll outer diameter is smaller than the above-mentioned curve, the upper roll and the lower roll are both formed by a curved part that is relatively moved in parallel in the barrel length direction. The difference in roll profile between the lower surface and the upper surface of the lower roll is expressed by a quadratic function including first-order and zero-order terms, and the plate crown is caused by bending, deflection, etc. that is inevitably formed during rolling of the roll. For the convex plate crown of the secondary component, correction conditions from O-flat to concave can be infinitely and freely applied. The excellent effect of being able to control this is achieved.

Therefore, the technical bottleneck that has hitherto prevented the ability to control the roll during rolling has been completely resolved, and there is also the effect that the sheet crown can be freely controlled.

Since the curve defining the initial crown of the rolling roll is given by a cubic function, compound elongation such as 1/4 part elongation of the rolled material does not occur.
An excellent effect is achieved in that a rolled material having an accurate widthwise thickness distribution as designed can be rolled.

[Brief explanation of drawings]

The drawings are explanatory diagrams of embodiments of the invention of this application, and FIG. 1 is a schematic cross-sectional front view of a part of a rolling roll showing the rolling mode of the upper and lower roll diameters for a rolled material, and FIG. 2 is a diagram showing an initial crown of the rolling roll. 3 is a schematic front view of the rolling rolls in a neutral state, and FIG. 4 is a schematic front view of the state in which the upper and lower rolls are shifted to control the sheet crown. 1...Top roll, 2...Bottom roll, 3, 3'...
...Initial crown, 4...Roll gap,
5...Rolled material.

Claims (1)

[Scope of Claims] 1. A rolling roll in which a pair of upper and lower rolls provided on a mill stand have an S-shaped axial outer shape and are formed into initial crowns that complement each other in axial position, The initial crown is a cubic function curve, and the initial crowns on the lower surface of the upper roll and the upper surface of the lower roll are formed by curves obtained by relatively moving the cubic function curve parallel to each other in the axial direction. rolling roll. 2. A pair of upper and lower rolls provided on a mill stand have an S-shaped axial outer shape, and the rolling rolls formed in initial crowns with complementary shapes in axial positions are moved relative to each other in the roll axial direction. In a rolling method that controls the plate crown or plate shape, the initial crown is a cubic function curve, and the initial crowns on the lower surface of the upper roll and the upper surface of the lower roll are relatively parallel to each other in the axial direction of the cubic function curve. A rolling method characterized in that the control range of the plate crown or plate shape is adjusted by forming a shifted curve.