JPH0420683B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a rolling roll, and in particular, the present invention relates to a rolling roll, and in particular, a rolling roll that is movable in the axial direction of the rolling material according to the width of the rolled material. The present invention relates to a rolling roll suitable for use in a rolling mill that controls the shape of a rolled material by adjusting its movement.

[Conventional technology]

As described in Japanese Patent Publication No. 50-19510, a rolling mill that controls the shape of a rolled material by adjusting the axial movement of the rolls uses an intermediate movable in the axial direction of the rolls between a highly rigid work roll and a reinforcing roll. Arranging rolls and adjusting the movement of this intermediate roll according to rolling conditions to change the contact pressure distribution between each roll to control the axial deflection of the work roll,
Furthermore, a rolling mill has been proposed in which the ability to control the shape of the rolled material is greatly improved by combining the roll bending action provided on the work roll with the movement adjustment of the intermediate roll.

In a rolling mill having such a configuration, the shape of the roll body end of the moving roll plays an extremely important role. In other words, in order to reduce the occurrence of sports rings by alleviating the stress concentration based on the contact pressure generated between each roll, and thus to improve the life of the roll, the shape of one end of the body of the moving roll must be adjusted accordingly. It is necessary to form the roll so that its diameter gradually decreases toward the tip.On the other hand, in order to maintain good shape control of the rolled material, the position of the moving roll body end must be set close to the width edge of the rolled material. Considering that it is important to accurately set and hold the moving roll, it is necessary to form the shape of the body end of the moving roll so that its diameter rapidly decreases toward the tip of the roll. be.

In order to satisfy these two demands, the special public
−16784, the shape of one end of the body of the intermediate roll, which is a moving roll, is adjusted to the diameter of the roll.
It has been proposed to form the radius of curvature from 0.1 to 10 times.

Furthermore, Japanese Patent Application Laid-Open No. 51-49152 discloses that although the reinforcing roll is not a moving roll, the shape of the body end of the reinforcing roll is formed into an arc shape or a parabolic shape to prevent stress concentration at the roll body end and sports ring. There have been proposals to achieve this.

[Problem to be solved by the invention]

However, among the above-mentioned known examples,
Since the roll of Publication No. 49152 is not intended for moving rolls, it maintains a high ability to control the shape of rolled material by a rolling mill using moving rolls, which is an advantage unique to moving rolls. The aim is completely unattainable.

In addition, in the case of the moving roll disclosed in Japanese Patent Publication No. 53-16784, although the stress concentration can be alleviated, the contact pressure distribution generated between the moving roll and the roll adjacent to the moving roll is The distribution is high on one side of the body end of the moving roll that is close to the
Along with this, the peak value of the contact pressure (or the Peter value of the Hertzian stress between the rolls, which is proportional to the contact pressure)
Since the rolls also become larger, there are restrictions on further improving the life of the rolls.

In other words, when a load is applied to the body end of one of the moving rolls in contact with the center of the body of the adjacent roll, flattening deformation occurs at the contact area between both rolls, and the axial contact length between the two rolls becomes longer than that without load. It will be longer than time.
At this time, even if the shape of the body end of the moving roll described above is made into an arc shape with a predetermined radius of curvature, this can certainly prevent stress concentration and damage at the contact point origin, but due to the load If the shape of the extended portion is inappropriate, the contact between the rolls will be abruptly broken at this point, resulting in the same problem as if a stepped body end were used, and the roll Lifespan cannot be improved.

The purpose of the present invention is to maintain a high ability to control the shape of rolled material by a rolling mill using moving rolls, and to prevent the impact on roll strength even when the contact length between rolls increases under rolling load. It is an object of the present invention to provide a rolling roll that can further improve the life of the roll by preventing scratches and the like.

[Means to solve the problem]

In order to achieve the above object, the present invention includes a work roll and a moving roll that supports the work roll and is movable in the axial direction of the roll, and rolls by adjusting the axial movement of the moving roll. In a rolling mill used for controlling the shape of a material, the movable roll is provided with a shaft extending from the center of the barrel to the tip of the barrel so that the entire length of the area contacts the adjacent roll when a rolling load is applied. A first roll diameter decreasing part with a small inclination angle where the roll diameter is gradually reduced; and a part of a region that is continuously connected to the first roll diameter decreasing part and closer to the first roll diameter decreasing part. A second roll diameter decreasing portion having a larger inclination angle and having a roll diameter that decreases more rapidly than the first roll diameter decreasing portion toward the tip of the body so that the roll contacts the adjacent roll when a rolling load is applied is formed. The rolling roll is constructed as follows.

[Effect]

According to the rolling roll configured as described above, the peak value of the linear pressure can be lowered, so the roll life is further improved, and the first roll diameter reduced portion formed at the end of the body of the moving roll always maintains its entire length during rolling. Since it comes into contact with the adjacent roll, the starting point of the body end essentially becomes the starting point of the second roll diameter reduction section, and therefore, even if the contact length between the rolls increases under rolling load, the body end of the moving roll Since the position can be set almost accurately with respect to the edge of the plate of the rolled material, the ability to control the shape of the rolled material by a rolling mill using moving rolls can be maintained at a high level.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a sectional view of a six-high rolling mill in which the rolling roll of the present invention is applied to an intermediate roll that is a moving roll, and FIG. 2 is a side view of the six-high rolling mill shown in FIG. 1. In these figures, 1 is a rolled material, 2, 3
are rotationally driven work rolls via shafts 4 and 5 by a drive device (not shown), and work rolls 6 and 7 are movable in the axial direction via shafts 8 and 9 by an intermediate roll axial movement device (not shown). The intermediate rolls 10 and 11 are reinforcing rolls. Both of these rolls are arranged within the housing 12. Specifically, the intermediate rolls 6 and 7 are in contact with the work rolls 2 and 3 along the axial direction of the rolls, and their axes are positioned on substantially the same vertical line as the axes of the work rolls 2 and 3. In addition, the reinforcing rolls 10 and 11 are in contact with the intermediate rolls 6 and 7 along the roll axis direction, and their axes are on the same vertical line as the axes of the work rolls 2 and 3 and the intermediate rolls 6 and 7. It is located so that it is located at 13 and 14 are metal chokes for work rolls, 15 and 16 are metal chokes for intermediate rolls, and 17 and 18 are metal chokes for reinforcing rolls. Hydraulic rams 19 and 20 for work roll bending are disposed on protrusions 21 and 22 of the housing 12, and are designed to apply bending force to the work rolls 2 and 3.

In such a rolling mill, the shape control ability can be greatly improved by accurately adjusting the position of the intermediate roll body end with respect to the width end of the rolled material and adjusting the work roll bending force. The shape of the body end of the intermediate roll that is a moving roll, that is, the shape of one body end of the intermediate roll located close to the width end side of the rolled material will be described in detail. FIG. 3 is an enlarged view of the end of one of the intermediate rolls 6, 7, and FIG. 4 is a diagram showing the state of contact between the rolls when a rolling load is applied. As shown in these figures, at the end of one of the intermediate rolls 6 and 7, there is a first roll diameter reducing roll with a small inclination angle, in which the roll diameter gradually decreases from the center of the roll to the end of the roll. part _T1 , that is, the tapered part is continuously connected to this first roll diameter decreasing part _T1 ,
Further, a second roll diameter decreasing portion T ₂ having a large inclination angle, in which the roll diameter decreases more rapidly than the first roll diameter decreasing portion T ₁ toward the body end, that is, a circular arc portion is formed. Moreover, as shown in FIG. 4, during rolling, the tapered portion of the intermediate roll 6 contacts the adjacent rolls 2, 10 over its entire length, while only a portion of the arcuate portion contacts the adjacent rolls 2, 10. We are starting to come into contact with Now, as shown in FIG. 3, the starting point of the tapered part of the intermediate rolls 6 and 7 is S ₁ , the starting point of the arc part is S ₂ , the radius of curvature at the starting point S ₂ is R ₂ , and the first roll diameter decreasing part T ₁ The length in the roll axis direction and the amount of relief in the radial direction of the tapered part are l ₁ and
y ₁ , the length in the roll axis direction and the amount of relief in the radial direction of the circular arc portion that is the second roll diameter reduced portion T ₂ , respectively.
l ₂ , y ₂ , the total length of the roll axis direction of the barrel end and the sum of the radial relief amount are respectively L and Y. Hereinafter, a method for determining the dimensions of the trunk end portions of the intermediate rolls 6 and 7 will be described.

First, Y is the sum of the radial relief amount y ₁ of the first roll diameter reduced portion T ₁ , the radial relief amount y ₂ of the second roll diameter reduced portion T ₂ , and the radial relief amount y ₁ . I will explain about it. During rolling, the entire length of the tapered part, which is the first roll diameter reduced part _T1 with a small inclination angle, contacts the adjacent rolls 2, 10, and the circular arc, which is the second roll diameter reduced part _T2, which has a large inclination angle. In order to make only a part of the part contact the adjacent rolls 2, 10, the amount of roll flattening between the rolls that occurs due to the application of the rolling load is larger than the relief amount y ₁ ,
The above-mentioned y ₁ and Y may be determined so as to be smaller than the escape amount Y, and the shapes of these roll body ends may be set.

The amount of Hertzian flattening δ that generally occurs between two rolls
(mm) is the linear pressure p of the contact pressure acting between the rolls
(Kg/mm), Young's modulus E (Kg/mm ² ) of the roll material, Poisson's ratio ν, and diameters d ₁ and d ₂ of both rolls (mm), it can be expressed by the following equation.

δ=p/πA2/3+lnπ(d ₁ + d ₂ )/2A−lnp……(
1) However, A=2(1-ν ² )/E where E: Young's modulus, ν: Poisson's ratio Figure 5 shows the Hertzian flattening amount δ generated between two rolls and the linear pressure p applied to these rolls. (pressure per unit length in the axial direction of the roll) using formula (1). According to this, the sum of the diameters of the two rolls (d ₁ + d ₂ ) It can be seen that in a practical range, it is approximately expressed by the following equation.

δ≒3×10 ^-4 p ……(2) Linear pressure p between rolls used in current rolling mills
The former is p = 200 to 500 Kg/mm for small rolling mills, aluminum rolling mills, skin pass rolling mills for steel, etc., and p = 900 to 1800 Kg/mm for large rolling mills and hard material rolling mills. In the case, the Hertzian flattening amount δ is δ=
0.06 to 0.15 mm, and in the latter case δ = 0.27 to 0.54 mm. Therefore, for example, in a small rolling mill, the radial relief amount y ₁ of the first roll diameter reduced portion T ₁ is y ₁ <0.06 mm,
For large rolling mills, y ₁ should be 0.27 mm. on the other hand,
The radial relief amount y ₂ of the second roll diameter reduced portion T ₂ is determined by considering y ₁ determined as described above,
In the case of a small rolling mill, the first and second roll diameter reduction parts
The total radial relief amount Y of T ₁ and T ₂ is Y>0.15
mm, and in the case of a large rolling mill, it may be determined so that Y > 0.54 mm.

Here, Y= _y1 + _y2 .

In other words, in a small rolling mill, y ₁ <0.06mm, Y>0.15mm,
In a large rolling mill, _one roll body end of the intermediate rolls 6 and 7 is rolled so that the diameter of the roll gradually decreases from the body center side toward the body end side. A tapered part that becomes a first roll diameter decreasing part _T1 with a small decreasing angle of inclination, and a tapered part that is continuously connected to this first roll diameter decreasing part and extending from the first roll diameter decreasing part toward the body end. A second roll diameter decreasing section with a large inclination angle where the roll diameter rapidly decreases.
Each shape of the circular arc portion to be T ₂ is set and formed.

FIG. 6 shows the calculation results of the linear pressure distribution, and the solid line a shows the case where a roll according to an embodiment of the present invention is applied. Calculation conditions are l ₁ = 300mm, l ₂ = 50mm, y ₁ = 0.15
mm, y ₂ = 1.25mm, R ₂ = 1000mm, work roll diameter
430mm, intermediate roll diameter 460mm, reinforcement roll diameter
1050mm, rolled material plate width 1000mm, rolling load P = 900ton
This is the case. This figure shows a conventional example in which, unlike the embodiment of the present invention shown in FIG. The calculation results obtained by applying the roll are also shown by the broken line b. From these calculation results, in the case of the example of the present invention, the peak of the linear pressure distribution is to the left compared to the conventional one, and the peak value is lower than the conventional Pb _nax = 1190 Kg/mm (Hertzian stress 198 Kg/mm ² equivalent) Pa _nax = 940Kg/mm
(equivalent to Hertzian stress of 176Kg/ ^mm2 ).

FIG. 7 is a diagram showing the relationship between Hertzian stress and the number of rolling times N at which spalling occurs in the case of a forged steel roll.
From this, N=6×10 ⁶ in this embodiment and N=6×10 6 in the conventional example.
4×10 ⁶ , so the roll life is 1.5 compared to the conventional one.
It can be seen that it can be doubled.

In the above-mentioned embodiment, since the first roll diameter decreasing portion T ₁ is formed so that the radius decreases more gently than the second roll diameter decreasing portion T ₂ , it is possible to set l ₁ > l ₂ and the linear pressure The peak value of can be lowered.

If l ₁ is made longer than l ₂ , the peak value of the linear pressure can be further reduced. Furthermore, the roll diameter reduction part
Of course, both T ₁ and T ₂ may be arcuate or tapered. When the second roll diameter reduced part T ₂ is an arc, the radius of curvature should be 0.1 to 10 times the roll diameter (especially 500 mm in radius of curvature).
or more), or if it is tapered, it is preferably 0.5 degrees or less.

In this example, when the rolling load is applied, the first roll diameter reduced part T ₁ contacts the entire length, and only a part of the second roll diameter reduced part T ₂ contacts the adjacent roll. Even if the rolling load changes, the first roll diameter reduced portion T ₁ is always in contact with the adjacent roll, and the boundary point between non-contact and contact with the adjacent roll moves in the second roll diameter reduced portion T ₂ . However, since the second roll diameter decreasing portion _T2 is formed so that its diameter decreases rapidly, the movement of the boundary point due to changes in rolling load can be reduced.
For this reason, the starting point of the body end of the moving roll can be practically considered as the starting point of the second roll diameter reduced portion _T2 , and therefore the body end of the moving roll can be accurately positioned at the end of the rolled material, and the rolling This has the effect of maintaining the machine's shape control ability at a high level.

In the above embodiment, a six-high rolling mill is provided with intermediate rolls 6 and 7 that are movable in mutually opposite axial directions between the upper and lower work rolls 2 and 3 and the upper and lower reinforcing rolls 10 and 111, respectively. However, in a four-high rolling mill in which the reinforcing roll is movable in the axial direction as shown in Fig. 8, or between the upper work roll and the upper reinforcing roll as shown in Fig. 9,
Of course, the rolling roll according to the present invention can be applied to moving rolls used in various types of rolling mills, such as multi-high rolling mills equipped with two intermediate rolls movable in mutually opposite axial directions.

〔Effect of the invention〕

According to the present invention, it is possible to maintain a high ability to control the shape of rolled material by a rolling mill using moving rolls, and even when the contact length between the rolls increases under rolling load, the roll strength is affected and damage is prevented. This has the effect that a rolling roll can be obtained which can further improve the life of the roll by preventing the occurrence of such problems.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a rolling mill equipped with rolling rolls according to an embodiment of the present invention, FIG. 2 is a side view of the rolling mill shown in FIG. 1, and FIG. 3 is an embodiment of the present invention. FIG. 4 is a partially enlarged view showing the shape of the body end of the roll. FIG. 4 is a diagram showing the contact state of each roll when the roll according to an embodiment of the present invention is applied. FIG. 5 is a diagram showing the contact state between the rolls. Figure 6 is a diagram showing the relationship between flattening amount and linear pressure between rolls, Figure 6 is a diagram showing the linear pressure distribution between rolls in a rolling roll according to an embodiment of the present invention, and Figure 7 is a diagram showing the relationship between the Hertzian stress and the linear pressure in the case of a forged steel roll. Figures 8 and 9 are diagrams showing the relationship between the number of rolling rotations at which spalling occurs, and are diagrams illustrating an example in which a rolling roll according to another embodiment of the present invention is applied to a moving roll used in another type of rolling mill. . Explanation of symbols, 1...Rolled material, 2, 3...Work roll, 6, 7...Intermediate roll, 10, 11...Reinforcement roll, _T1 ...First roll diameter reduced part, _T2
...Second roll diameter reduced part, l ₁ , l ₂ ... Roll axial length of the roll diameter reduced part, y ₁ , y ₂ ... Radial relief amount of the roll diameter reduced part, p... Linear pressure , δ... Hertzian stress, N... Number of rolling times at which spalling occurs.

Claims (1)

[Claims] 1. A work roll, and a moving roll that supports the work roll and is configured to be movable in the axial direction of the roll, and controls the shape of the rolled material by adjusting the axial movement of the moving roll. In a rolling mill used in a rolling mill, the diameter of the roll is set at the end of the body of the moving roll from the center of the body to the tip of the body so that the entire length of the area contacts the adjacent roll when a rolling load is applied. A first roll diameter decreasing portion having a small inclination angle that decreases to A second roll diameter decreasing portion having a larger inclination angle and having a larger roll diameter decreasing portion than the first roll diameter decreasing portion toward the tip of the body is formed so as to come into contact with an adjacent roll. rolling roll. 2. In what is stated in claim 1,
A rolling roll characterized in that a region in the roll axis direction of the first roll diameter reduced portion at the body end portion of the moving roll is formed longer than a roll axial region of the second roll diameter reduced portion.