JPH11226641A - Setting method of roll position of roller leveler - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a setting method of a roll position of a roller leveler so as to reduce the influence resulting from variance of a zero point of a roll position of a roller leveler. SOLUTION: As for some inlet side roll press quantity Sin , the relationship between an outlet side roll pressing quantity Sout and a residual camber height hres of a material to be straightened is obtained beforehand, a max outlet side roll pressing quantity satisfying a formula (1) is S<0> out , under this condition, a roll position is set to the outlet side roll pressing quantity S satisfying Sout < S<0> out and hres =0. dhres /dSout =0...(1), by this method, in the case a zero point of a roll setting position of a roller leveler is varied, straightening effect is stably obtained, frequent zero point adjustments of a roll position of the roller leveler are not required, thus, straightening is efficiently conducted.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a roller leveler in which a plurality of rolls are vertically arranged in a staggered manner, and the material to be corrected is repeatedly bent between the rolls to flatten the warpage of the material to be corrected. It relates to a method for setting a roll position. In the specification of the present invention, the term “roll” simply refers to a “work roll” that directly contacts the material to be corrected and bends the work, and is used only when distinguished from a backup roll that supports the work roll. I will call it.

[0002]

2. Description of the Related Art Roller levelers in which a plurality of rolls are arranged vertically in a staggered manner are used in order to flatten warpage generated in a rolling process or a cooling process of a plate, a profile, a tube, a wire, or the like. The correction action by the roller leveler is to flatten the warpage of the material to be corrected by repeatedly bending the material to be corrected.

In general, many roller levelers have a mechanism in which the position of one of the upper and lower roll groups is fixed, and the other roll group is tilted so that each roll pushes the material to be corrected. The roller leveler having such a mechanism operates by setting the entrance and exit roll positions of the movable roll group. Generally, the roll position on the entrance side is required to flatten the warpage of the material to be corrected in consideration of the dimensions of the material to be corrected, the material constant, the warpage, the rigidity of the roller leveler, and the like. Although set to be the roll pushing amount, the roll position on the exit side is determined so that the roll pushing amount in the second roll from the last stage becomes zero. Here, the roll pushing amount is a value obtained by subtracting the thickness of the material to be corrected from the distance between the vertex of the roll and a straight line connecting the vertexes of the front and rear rolls of the roll. The case where the distance to the straight line connecting the vertices is shorter than the thickness of the material to be corrected will be described as positive.

Japanese Unexamined Patent Publication No. 53-87962 discloses that the maximum amount of work on the entrance side, the degree of work on the exit side, the sheet thickness, the sheet width, and the yield point stress are used to determine the amount of press-in and the amount of press-out on the upper roll group. Is determined. In particular, it is assumed that the maximum input side processing degree should be 3 or more and the output side processing degree should be 1. The degree of processing is obtained by dividing the curvature given to the material to be corrected during the correction by the elastic limit curvature of the material to be corrected.

The relationship between the roll position of the roller leveler and the curvature of the material to be corrected is shown by various empirical formulas and theoretical calculation methods.
Vol. 1, No. 349 (1990), pp. 208-212, proposes an equation in which the curvature of the material to be corrected is related to the roll pitch of the roller leveler and the roll pressing amount by a proportionality constant. , "Papers for Spring Meeting on Plasticity in Spring 1973" (1973), p. 143-
On page 146, a method based on beam bending theory is proposed.

In this manner, the roll position at which the curvature to be given to the material to be corrected is obtained, and if necessary, the correction reaction force at the time of performing the correction by using this roll setting, is obtained. The roll position is set by taking into account the deformation of the roller leveler caused by, and correction is performed.

[0007]

However, if the zero point of the roll position of the roller leveler is not accurately adjusted, the set roll pushing amount differs from the actual roll pushing amount, and the curvature given to the material to be corrected is also different. It will be different from what you expected. JP-A-61-53014 discloses an electric circuit formed through a housing when a jig made of a conductor is sandwiched between the upper and lower rolls between the upper and lower rolls. Thus, a technique for finding a zero point of a roll setting position of a roller leveler is disclosed. However, this technique cannot measure a displacement that does not require a load, that is, a backlash, at least for the upper roll. Also, since the zero point of the roll setting position of the roller leveler is considered to change over time due to wear of the rolls and roll bearings, etc., when setting the roll position in consideration of the change of the zero point of the roll setting position of the roller leveler. It is necessary to measure and grasp the zero point of the roll setting position of the roller leveler at any time. However, at present, there is no method for grasping the zero point of the roller setting position of the roller leveler simply and accurately, and it is inevitable that there is a variation in the range of the zero point of the roller setting position of the roller leveler. .

Further, since many roller levelers in which the upper and lower roll groups are integrated do not have a mechanism for adjusting the position of each roll, a method for accurately grasping the zero point of the roll set position of the roller leveler is provided. Even if there is, the zero point of the roll setting position of the roller leveler cannot be accurately adjusted. As a method of adjusting the zero point of the roll set position of such a roller leveler, for example, the upper roll group is pushed through a steel plate having a certain thickness, and the load values provided by the load cells provided at the four housing posts of the roller leveler are respectively set. A method is used in which a position having a predetermined value is set as a zero point of a roll setting position.
However, although it is considered that the above-described method can prevent the zero point of the roll setting position from being greatly deviated, it is impossible to accurately adjust the zero point of the roll setting position. It is also conceivable that the execution of the zero point adjustment may cause the zero point of the roll setting position to be deviated.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a method of setting the roll position of a roller leveler so as to reduce the influence of a variation in the zero position of the roll position of the roller leveler on the correction effect.

[0010]

SUMMARY OF THE INVENTION According to the present invention, in order to reduce the influence of the variation in the zero point of the roll setting position of the roller leveler on the correction effect, the amount of inward roll pushing _in of the roller leveler with respect to the outgoing roll is determined. Depression amount s
_out and the residual warp height h _res of the material to be corrected are obtained in advance, and when the maximum amount of pushing in the exit side roll that satisfies Expression (1) is s ⁰ _out , s _out <s ⁰ _out , and h
_The roll position is set to the outgoing roll pushing amount s _out that satisfies _res = 0. dh _res / ds _out = 0 (1)

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION As a result of numerous theoretical and experimental studies, the present inventors have obtained the following findings. It is difficult to adjust the zero point of the roll setting position of the roller leveler with high accuracy, and even if the zero point of the roll setting position is adjusted based on a generally used method of adjusting the zero point of the roll setting position, a certain range is not obtained. There is a variation in the zero point of the roll setting position in the area. Due to the variation of the zero point of the roll setting position, particularly when the actual roll pushing amount is larger than the set roll pushing amount, the curvature given to the material to be corrected becomes excessive with respect to the set curvature. If such a phenomenon occurs particularly in a later stage, the residual warpage of the material to be corrected after being corrected by the roller leveler becomes larger than the set residual warpage, and it becomes difficult to flatten the warpage of the material to be corrected. Therefore, in the present method, assuming that the zero-point adjustment of the roller set position of the roller leveler has been accurately performed, the final roll of the roller leveler, or a plurality of rolls at the subsequent stage, do not apply plastic bending to the material to be corrected. Next, the condition for setting the roll position of the roller leveler is determined.
In the setting condition of the roll position determined by this method, when the zero point adjustment of the roll setting position is correctly performed, the final roll of the roller leveler, or a plurality of subsequent rolls, does not contact the material to be corrected. On contact or in contact, these rolls do not impart plastic bending to the material to be straightened. That is, at this time, the residual warpage of the material to be corrected does not change between the case where the roll exists and the case where the roll does not exist.

On the other hand, when there is a variation in the zero point of the roll setting position and the actual roll pushing amount is larger than the set roll pushing amount, an excessive curvature is given to the material to be corrected. For the first time, the final roll, or a plurality of rolls at the rear, apply plastic bending to the material to be corrected. Here, that the final-stage roll or a plurality of subsequent-stage rolls contribute to the plastic bending of the material to be corrected means that the material to be corrected depends on whether the roll exists and when the roll does not exist. The case where the residual warpage changes will be described. In addition, at this time, the plastic bending given to the material to be corrected by the final roll or a plurality of subsequent rolls acts to reduce the residual warpage of the material to be corrected. It is possible to reduce the difference between the warpage setting and the actual setting. In this way, by not actively using the final roll of the roller leveler or a plurality of rolls at the subsequent stage, it is possible to reduce the influence of the variation in the zero point of the roll set position of the roller leveler on the correction effect of the material to be corrected. Can be.

In order to determine the setting conditions of the roll position of the roller leveler so that the final stage roll of the roller leveler or a plurality of subsequent rolls do not cause plastic bending of the material to be corrected, the dimensions, material constants, In consideration of the warpage and the rigidity of the roller leveler, etc., the outgoing roll pushing amount s _out and the residual warping height of the material to be corrected are compared with the incoming roll pressing amount s _in necessary to flatten the warping of the material to be corrected. The relationship with _hres is determined experimentally or theoretically. Here, with respect to the residual warpage height _hres , the direction of the warp is represented by positive and negative signs. FIG. 1 shows an example of the relationship between the _delivery roll pushing amount s _out and the residual warp height h _res of the material to be corrected.
At this time, the pushing amount maximum exit-side roll that satisfies the following equation (1) when the ^{_{s 0 out, s out <s}} 0 out, and h _res = 0 so that the exit-side roll pressing amount s _out to meet the Determine the setting conditions for the roll position. dh _res / ds _out = 0 (1)

In order to experimentally determine the setting conditions of the roll position of the roller leveler based on the present method, for example, after adjusting the zero point of the roll setting position of the roller leveler, various conditions are set while the amount of pushing in on the entering side is fixed. The material to be corrected is passed through the plate set at an appropriate amount of pushing in on the outlet side, and the relationship between the amount of pushing in on the outlet side and the residual warpage of the material after straightening by the roller leveler is measured. From the relationship between the amount of pushing-out on the delivery side measured in this way and the residual warpage of the material to be corrected after being corrected by the roller leveler, the amount of pushing-out on the delivery side that makes the residual warpage of the material to be corrected after the correction by the roller leveler zero is obtained. Of the pushing-out amounts obtained to make the residual warpage of the material to be straightened after correction by the roller leveler zero, the maximum values of these are not set as the optimum roll positions, but, for example, the second largest pushing-out force. Set the amount as the optimal roll position. Also,
To theoretically determine the setting conditions for the roll position of the roller leveler, for example, assuming that the zero-point adjustment of the roll setting position of the roller leveler was performed correctly, analyze the final stage or a plurality of rolls at the subsequent stage. The calculation is performed by excluding the target from the object, and the amount of pushing-out on the outgoing side with the residual warpage of the material to be corrected after the correction by the roller leveler being zero is obtained and set as the optimum roll position.

[0015]

[Embodiment 1] The present invention will be described below with reference to the drawings showing one embodiment. This embodiment is an example in which the optimum roll setting conditions are experimentally studied. The roller leveler used in the present embodiment is a roller leveler composed of a total of 11 rolls 1 as shown in a conceptual side view in FIG. 2, in which five upper rolls and six lower rolls are equally spaced, respectively. , Are arranged in a staggered manner. The lower roll group 2 consisting of six lower rolls is a fixed roll group whose position is fixed, while the upper roll group 3 consisting of five upper rolls
Is capable of tilting and pushing the lower roll group 2 using the entry-side pushing device 4 and the exit-side pushing device 5 between the housing 6 and the upper roll group 3.

As a material to be corrected, a sheet thickness of 5 mm and a sheet width of 4000 m
m, a hot steel plate having a temperature of 700 ° C. was used. First, s _in = 5.
8mm was selected. Next, the inward pushing amount s _in = 5.8 mm
, And the outlet pushing amount s _out for flattening the material to be corrected was searched for. As shown in FIG. 3, the height of the residual warpage of the material to be corrected after being corrected by the roller leveler changes in accordance with the change in the amount of pushing in the exit roll. Here, in FIG. 3, the warpage height is positive for the upward warpage. When the exit side pushing amount is excessive, the warped remains in the material to be corrected, and with the decrease in the exit side pushing amount, the residual warp height of the material to be corrected after the straightening by the roller leveler decreases, and eventually becomes zero. (S
_out = 0.3 mm). Furthermore, when the amount of pushing in on the outlet side is reduced, the direction of the residual warpage after the correction of the material to be corrected by the roller leveler is reversed, and the absolute value of the warpage height increases,
When the pushing-out amount is further reduced, the warp height takes an extreme value at a certain point (s _out = −0.2 mm). When the warp height exceeds this point, the absolute warp height of the material to be corrected after being corrected by the roller leveler is absolute. The value decreases and becomes zero again (s _out = −0.6
mm). In this embodiment, was the largest exit-side roll pressing amount s ⁰ _{ou t} = -0.2mm satisfying the equation (1).

[0017] Thus, although the delivery side pressing amount to zero residual camber height after correction by roller leveler of the straightening member there are a plurality, s _{ou t} = satisfying s _out <s ⁰ _out the present invention - 0.6 mm is set as the optimal roll-in amount on the exit side. This condition (s _in = 5.8 mm, s _out = −0.6 mm)
FIG. 4 shows the variation in the residual warp height of the material to be corrected after the correction by the roller leveler when the correction work is performed by the method described above. Incidentally, as a conventional example, straightening work with the maximum value of the output-side pressing amount to zero residual camber height after correction by roller leveler of the straightening member _{(s in = 5.8mm, s out} = 0.3mm) Are also shown. Compared to the conventional example, in the present invention, it is possible to keep the variation of the residual warp height of the material to be corrected within a narrow range, and reduce the influence of the variation of the zero point of the roll setting position on the correction effect of the material to be corrected. It became possible.

In this embodiment, the maximum value of the outgoing pushing amount s _out that s _out <s ⁰ _out is satisfied and the residual warp height of the material to be straightened after the straightening by the roller leveler is zero is the optimum roll. set the position by performing the operation on the basis of this, although stable correction effect is obtained, in order to obtain a more stable straightening effect, s _out <s ⁰ _{ou t}
And the second and subsequent largest values among the pushing-out amounts at which the residual warp height of the material to be corrected after the correction by the roller leveler is zero may be set as the optimum roll position.

[Embodiment 2] This embodiment is an example in which an optimum roll setting condition is theoretically examined. The roller leveler used in this embodiment is the same as that used in the first embodiment. In addition, since the material to be corrected is a hot steel plate having a thickness of 5 mm, a width of 4000 mm, and a temperature of 700 ° C. as in the first embodiment, elastic constants E = 15,670 kgf / mm ² and yield stress σ _Y = 9.0 kgf / mm ² was used. The theoretical calculation is based on the method based on the bending theory of the beam shown in “Transactions of the Spring Working Group on Plasticity, 1973” (1973), pp. 143 to 146. It was performed using what was considered.

First, assuming that the zero point of each roll setting position has been accurately adjusted, 1
Considering only zero rolls, the optimum inward and outward pushing amount for flattening the warp of the material to be corrected was theoretically determined. The pushing-in amount at the entrance / exit side (s _in = 5.8 mm, s _out = −0.
FIG. 5 shows the variation in the residual warp height of the material to be corrected after being corrected by the roller leveler when the operation was performed based on 6 mm). In consideration of the 11 present all roll as a conventional example, when the operation to determine the optimum inlet and outlet pressing amount for flattening the warp of the straightening member theoretically (s _in = 5.
8 mm, s _out = 0.3 mm) are also shown. During the collection of the measurement results, the progress of the wear of the rolls and the bearings was considered, and further, since the zero point adjustment of the roll set position was performed by the above-described conventional method, there was also a change in the zero point of the roll set position. However, compared to the conventional example, in the present invention, it is possible to keep the variation in the residual warp height of the material to be corrected within a narrow range, and to evaluate the effect of the variation in the zero point of the roll setting position on the effect of correcting the material to be corrected. It became possible to make it smaller.

In the present embodiment, the setting condition of the roll position is determined by calculating the final roll of the roller leveler by excluding the roll from the analysis target, and the operation is performed based on the roll condition. Although it was obtained, in order to obtain a more stable correction effect, the roll position setting conditions were determined by performing calculations by excluding not only the final roll of the roller leveler but also multiple rolls at the subsequent stage from the analysis target. do it.

[0022]

The relationship between the exit roll pushing amount s _out and the residual warp height h _res of the material to be corrected is determined in advance for the entry roll pushing amount s _{in with the} roller leveler, and satisfies the equation (1). S ⁰ _out
When the roll position is set to the outgoing roll pushing amount s _out that s _out <s ⁰ _out and h _res = 0, the operation is performed, and the wear of the rolls and bearings of the roller leveler progresses, Even when the zero point of the roll setting position fluctuates by performing the zero point adjustment of the position, the correction effect can be stably obtained. Further, since it is not necessary to frequently perform the zero-point adjustment of the roller position of the roller leveler, it is possible to eliminate the time loss due to the work of zero-point adjustment of the roller position of the roller leveler, and it is possible to perform the correction operation with higher efficiency.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing a relationship between an exit pushing amount s _out and a residual warp height h _res of a material to be corrected after being corrected by a roller leveler.

FIG. 2 is a side view showing an outline of a roller leveler used in the embodiment of the present invention.

FIG. 3 is an ejection-side pushing amount s obtained in Example 1 of the present invention.
diagram showing the relationship between the _out and residual warp height h _res after correction by roller leveler of the straightening member.

FIG. 4 is a diagram comparing the variation in the residual warp height of the material to be corrected between Example 1 of the present invention and a conventional example.

FIG. 5 is a diagram comparing the variation in the residual warp height of the material to be corrected between Example 2 of the present invention and a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Work roll 2 Lower roll group 3 Upper roll group 4 Entry side pushing device 5 Exit side pushing device 6 Housing

Claims (1)

[Claims] 1. A method for setting a roll position of a roller leveler for arranging a plurality of rolls vertically in a staggered manner and repeatedly bending the rolls between the rolls to flatten the warpage of the straightened material. For the input roll pushing amount s _{in with the} roller leveler, the relationship between the output roll pushing amount s _out and the residual warp height h _res of the material to be corrected is obtained in advance, and the maximum delivery that satisfies the formula (1) is obtained. When the roll pushing amount is s ⁰ _out ,
A roll position setting method for a roller leveler, wherein the roll position is set to an outgoing roll pushing amount s _out that s _out <s ⁰ _out and h _res = 0. dh _res / ds _out = 0 (1)