JPH05337519A - Rolling mill using sleeve shift roll - Google Patents

Abstract

PURPOSE:To provide a rolling mill which can maintain sufficient rigidity and shape controlling capacity against a rolling reaction force, to correct the shape defect of quarter waviness and middle waviness accompanying edge waviness and to reduce edge drop while a roll mark of a sleeve roll is prevented from being transferred to a plate. CONSTITUTION:In a rolling mill wherein sleeves 2, 2' bisected on the outer peripheries of the arbors of one or two backup rolls 1 of a multistage mill are made up movably in the axial direction, the sleeves 2, 2' are moved in accordance with the plate width of a rolled plate to change the relative position in the axial direction and to control the crowns of work rolls 3, 4, the width B of the bisected sleeves 2, 2' and the diameter D of an intermediate roll 11 are specified as B=(0.25-0.40)W and D<=0.33W, wherein W is the barrel length of the work roll.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rolling mill using sleeve shift rolls.

[0002]

2. Description of the Related Art Shape-controlled rolling will be described by taking a conventional quadruple rolling mill as an example. The conventional shape-controlled rolling method has been to add an initial crown to a work roll, use a roll bender, or use both of them in combination.

The method of giving an initial crown to a work roll requires preparing a large number of rolls having various crowns corresponding to the material and size of the rolled material and changing the roll every time the rolling conditions change.

The roll bender method alone or the combined use of the roll bender method and the initial crown method is capable of simply correcting a shape defect such as middle stretch or ear wave, but quarter stretch or middle stretch and ear wave occur together. It was impossible to correct the defective shape.

Next, a conventional rolling mill using sleeve shift rolls (hereinafter referred to as SSM) will be described. As shown in FIG. 2, the conventional SSM has a pair of upper and lower backup rolls 1 and 5 each provided with a sleeve 10, and asymmetrically shifting the sleeves 10 and roll bending to control the plate shape and edge drop. Is what you are trying to do. In this system, the upper and lower backup rolls 1 and 5 must be provided with a shift mechanism,
Further, the purpose is mainly to reduce the edge drop, and it is impossible to correct the shape defect caused by the quarter stretch or the middle stretch and the ear wave by adjusting the position of the sleeve 10.

[0006]

SUMMARY OF THE INVENTION In view of the above-mentioned problems of the prior art, an object of the present invention is to produce quarter elongation and medium elongation and seismic waves while maintaining sufficient rigidity against rolling reaction force. It is to obtain a rolling mill capable of correcting a defective shape and reducing edge drop.

[0007]

The present invention takes the following means in order to achieve the above object.

That is, for the purpose of correcting the shape defect caused by the quarter stretch or medium stretch and the ear wave and reducing the edge drop, one or two backup rolls are divided into two sleeves on the outer circumference of the arbor in the axial direction. A rolling mill (hereinafter referred to as WS) that is configured to be movable, and changes the relative position in the axial direction by moving the sleeve according to the plate width and plate shape to control the crown of the work roll.
(Referred to as SM), the width of the sleeve divided in two; B and the diameter of the intermediate roll; D is the work roll body length;
For W, B = (0.25 to 0.40) W and D ≦ 0.33W.

FIG. 1 shows a case where the upper back-up roll 1 is provided with the two-divided sleeves 2 and 2'for the 5Hi rolling mill using the WSSM. By using this rolling mill, as shown in FIGS. 3 and 4, the positions of the sleeves 2 and 2 ′ are arbitrarily moved in the axial direction according to the plate width and the plate shape, so that quarter elongation, middle elongation, and ear wave can be achieved. It is possible to correct the defective shape and control the edge drop. In addition, the intermediate roll 11 allows the sleeve roll 2,
It is possible to prevent the 2'roll mark from being transferred to the plate 8.

That is, this system is characterized in that the smaller the sleeve width and the larger the amount of change in the relative position in the axial direction, the wider the shape control range. However, as shown in FIG. 3, when the sleeves 2 and 2 ′ are located near both ends of the work roll 3, the work roll 3 is excessively bent due to the reaction force received from the plate 8, and the skin pass mill arranged on the CGL line. For example, it becomes difficult to obtain a uniform roughness in the plate width direction, and it becomes difficult to obtain a uniform shape and plate thickness. Therefore, while maintaining the required rigidity of the work roll 3, a good shape can be obtained. In order to obtain controllability, as described above, the width of the sleeves 2 and 2'divided into two; B is the body length of the work roll 3;
0.40) W. Further, if the diameter D of the intermediate roll 11 provided for the purpose of preventing the roll marks of the sleeve rolls 2 and 2 ′ from being transferred to the plate 8 is large and the rigidity is too large, the shape control ability is deteriorated. In order to secure the effect of improving the shape control capability of the WSSM, as described above,
The diameter of the intermediate roll 11; D is D ≦ 0.33 W with respect to the body length W of the work roll 3.

[0011]

In the rolling mill, the sleeve 2 divided into two parts
2'width; B and the diameter of the intermediate roll 11; D is the body length of the work roll 3;
0) W and D ≦ 0.33 W, the sleeves 2 and 2 divided into two parts configured to maintain the rigidity of the work roll 3 necessary to achieve a uniform rolling force in the plate width direction. 'Is attached to the backup roll 1 and an intermediate roll 11 having a diameter capable of maintaining the shape control ability is provided, and the positions of the two-divided sleeves 2 and 2'are arbitrarily moved in the axial direction, and the crown amount of the work roll 3 is arbitrarily set. By setting to, it is possible to prevent the roll marks of the sleeve rolls 2 and 2'from being transferred to the plate, and to correct the shape defect caused by quarter stretch or medium stretch and the ear wave and control the edge drop. Become.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings by taking a case of a 5Hi skin pass mill as an example in consideration of preventing the roll mark of a sleeve roll from being transferred to a plate. To do.

FIG. 1 shows a case in which only the upper backup roll 1 of the 5Hi rolling mill is provided with two-split sleeves 2 and 2 '. If this rolling mill is used, as shown in FIGS. 3 and 4, the sleeves 2 and 2'depending on the plate width and plate shape.
By arbitrarily moving the position of in the axial direction, it is possible to correct the shape defect caused by the quarter wave or the middle wave and the ear wave and to control the edge drop.

That is, this system is characterized in that the smaller the sleeve width B and the larger the amount of change in the relative position in the axial direction, the wider the shape control range. However, as shown in FIG. 3, when the sleeves 2 and 2 ′ are located near both ends of the work roll 3, the work roll 3 is excessively bent by the reaction force received from the plate 8, and the skin pass arranged on the CGL line is moved. Taking a mill as an example, a uniform rolling force cannot be obtained in the plate width direction, and it becomes difficult to obtain a uniform roughness, shape, and plate thickness in the plate width direction. The diameter of the intermediate roll 11 provided for the purpose of preventing the roll marks of the sleeve rolls 2 and 2'from being transferred to the plate 8;
If D is thick and the rigidity is too large, the shape control capability is reduced. The conditions necessary for solving these problems will be described below.

In FIG. 1, the body length of the work roll 3 is W
(Mm) and the widths of the sleeves 2 and 2'are represented by B (mm), respectively. Assuming that the width of the plate 8 is b (mm), the non-dimensional coefficient representing the minimum plate width is α ₁ and the non-dimensional coefficient representing the maximum plate width is α ₂ , then b _Min = α ₁ W b _Max = α ₂ W It is represented by 1). Since the work roll 3 has the smallest rigidity at the maximum plate width, that is, when b = α ₂ W,
At this time, the positions of both outer ends of the sleeves 2 and 2 ′ are on the plate edge in consideration of the edge drop control, and the distance between the inner ends of the sleeves 2 and 2 ′ serving as the fulcrum of the work roll 3 is assumed. Is L (mm), L = (α ₂ −2β) W (Formula 2) β = B / W Further, the equivalent work roll diameter de (mm) in the case of 5Hi is the work roll diameter d ₁ and the intermediate roll diameter D.
Using, represented by de = [d ₁ ⁴ + D ^{4] (1/4),} and further, by using a dimensionless number γ representing the roll diameter is expressed by de = γW (Equation 3). Using the above relationship, the maximum deflection δ (mm) at the center of the work roll when the linear load p (kgf / mm) due to the rolling reaction force acts on the work roll 3 is the longitudinal elasticity of the work roll 3 and the intermediate roll 11. The coefficient is 21000k
If gf / mm ² , δ = ηp (L / de) ⁴ = ηp [(α ₂ −2β) / γ] ⁴ (Equation 4) η = 5 × 64 / (384 × E × π) = 1.26 × 10 ^-5
It is represented by (kgf / mm ² ) ^-1 . The relationship between βB / W and δ is shown in FIG.

Here, γ = de / W = 0.2 to 0.3,
α ₂ = b / W = 0.9, p = 280 (kgf / mm)
Is set within a practical range with respect to the conditions required to secure the elongation and the roughness transfer rate in the skin pass mill. Then, in Expression 4, if the maximum deflection is set to 50 μm or less under the above-mentioned use conditions, according to the knowledge of the present inventors, the rigidity required for the work roll is secured, and the work roll is required in the width direction. A uniform rolling force is obtained, and a transfer having a good shape and a uniform roughness is secured.

That is, β must be 0.25 or more to satisfy the above conditions. Further, even if β exceeds 0.4, there is no effect of improving the rigidity.

That is, B = (0.25 to 0.40) W
Under the conditions described above, in the rolling mill of the present invention, the rigidity of the work roll required to achieve a uniform rolling force in the strip width direction is secured.

Next, the intermediate roll diameter capable of maintaining the effect of improving the shape control ability will be described.

FIG. 6 shows a dimensionless number ζ = representing the intermediate roll diameter.
The relationship between D / W and the shape control range ratio; RMD2 and RMD4 is shown. Where RMD2 = λ2 / λ20, RMD4 =
λ4 / λ40, where λ2 and λ4 are the edge mechanical plate crown and quarter mechanical plate crown in the case of 5Hi using WSSM, and λ20 and λ40 are the edge mechanical plates in the case of the conventional 4Hi rolling mill. Crown, quarter part Mechanical plate crown. That is, the larger the RMD2 and RMD4, the wider the shape control capability range as compared with 4Hi.

From FIG. 6, the diameter of the intermediate roll is increased,
Under the condition of> 0.33, RMD2 <1. Therefore, even if a sleeve shift roll is used, the shape control capability is 4H.
i will be lower than the rolling mill. That is, in order to maintain the effect of improving the shape control capability by using the sleeve shift roll, it is necessary to satisfy ζ ≦ 0.33.

That is, in the rolling mill of the present invention under the condition of D ≦ 0.33 W, the effect of improving the shape control capability is secured.

The shape control capability of the rolling mill of the present invention will be described below with reference to the results of evaluation by the mechanical plate crown method. Calculation is work roll diameter; d ₁ = φ500
mm, backup roll diameter = φ940 mm, roll body length; rolling width W = 1800 mm, plate width; b = 160
0 mm, plate thickness = 1.6 mm, yield stress = 50 kgf / m
It was carried out under the condition that a strip of m ² was rolled at an elongation of 1%. For roll bending, the incremental bending is Max. 40ton, Decrees Bending Max. It was set to 30 tons.

FIG. 7 is a diagram showing the results of the 4Hi rolling mill. FIG. 8 shows a sleeve shift roll according to the present invention (sleeve width: B = 500 mm, intermediate roll diameter: D = φ200).
(mm) is applied as shown in FIG. In this way, when the sleeve shift roll is used and the intermediate roll diameter is appropriately selected, the shape control range is expanded several times, and the roll mark of the sleeve roll is prevented from being transferred to the plate, while the quarter extension and middle extension are performed. It is possible to correct a defective shape caused by the simultaneous occurrence of ear waves.

[0025]

As described above, the width of the sleeve divided into two parts: B and the diameter of the intermediate roll; D is the body length of the work roll; W is B = (0.25 to 0.40) By setting W and D ≦ 0.33W, the backup roll is equipped with a two-divided sleeve configured to maintain the rigidity of the work roll necessary to achieve a uniform rolling force in the plate width direction. In addition, by providing an intermediate roll having a diameter capable of ensuring shape controllability, the position of the two-divided sleeve can be arbitrarily moved in the axial direction, and the crown amount of the work roll can be arbitrarily controlled. It is possible to correct the defect in shape caused by quarter stretch or medium stretch and the ear wave and to control the edge drop, while preventing the transfer to the plate.

It is clear that the cost is advantageous as compared with the conventional type SSM. Further, it is possible to incorporate it into an existing 4Hi rolling mill by appropriately selecting the intermediate roll diameter, and it is possible to modify it into a rolling mill excellent in shape controllability at low cost.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a 5Hi rolling mill using a WSSM of the present invention.

FIG. 2 is a sectional view of a 4Hi rolling mill using a conventional type SSM.

FIG. 3 is an explanatory diagram of a usage method of the WSSM at the maximum plate width.

FIG. 4 is an explanatory diagram of a method of using the WSSM when the minimum plate width is used.

FIG. 5 is an explanatory view of the rigidity condition of the WSSM of the present invention.

FIG. 6 is an explanatory view of an intermediate roll diameter condition of the WSSM of the present invention.

FIG. 7 is a shape control range of a 4Hi rolling mill.

FIG. 8 is a shape control range of a 5Hi rolling mill using the WSSM of the present invention.

[Explanation of symbols]

 1 Upper pack-up roll (arbor) 2, 2 ', 10 Sleeve 3, 4 Work roll 5 Lower backup roll 6 Declease roll bender 7 Increase roll bender 8 Plate 9 Work roll deflection 11 Intermediate roll

Claims (1)

[Claims] 1. A one or two backup rolls of a multi-stage rolling mill is constructed such that a sleeve divided into two parts on the outer circumference of an arbor is movable in the axial direction, and the sleeve is moved according to the plate width of a rolling plate. In a rolling mill in which the relative position in the axial direction is changed to control the crown of the work roll, the width of the sleeve divided into two parts; B and the diameter of the intermediate roll;
D is the work roll body length; W is B = (0.25 to
0.40) W and D ≦ 0.33 W.