JPH10202305A - Grinding method for rolling roll - Google Patents

Abstract

PROBLEM TO BE SOLVED: To correctly detect the position of level different wear in a rolling roll and to correctly grind the level different wear part only in the rolling roll by extracting a high frequency component only from the measured result of the roll profile measured on line and comparing the high frequency component with the prescribed threshold. SOLUTION: A high pass filter treatment is applied to the roll profile to extract the high frequency component. By this way, an initial crown and thermal crown or mechanical deflection shape of component are reduced from the high frequency component, and the component equivalent to the roll profile change due to level different wear becomes predominant. Next, the position wherein the high frequency component exceeds the threshold is made to be the position of level different wear in the rolling roll by comparing the high frequency component with the prescribed threshold. And when the position of detected level different wear exists in e.g. the left side of the roll, the zone R between that position and the left end of the roll is ground by the required depth (δ) with a roll grinding device.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for grinding a rolling roll online in a rolling process of a metal material such as steel.

[0002]

2. Description of the Related Art Generally, in a hot rolling process of steel or the like, step wear (partial wear) of a rolling roll in a region where the rolling roll and a rolled material come into contact with the rolling progresses. In recent years, in order to prevent the deterioration of the shape of the rolled material due to the step wear of the rolling roll, an online roll grinding device has been put into practical use as a means for eliminating the step wear online without replacing the rolling roll. When grinding with an online roll grinding device, it is necessary to grasp the position and the amount of wear of the step wear of the rolling roll. Conventionally, these have been grasped on the basis of a prediction calculation result for predicting a wear amount based on, for example, a rolling amount and a rolling time.

[0003] Recently, an apparatus for measuring the roll profile online has been put into practical use in order to grasp the position and the amount of wear of the step difference of the rolling roll. For example, Japanese Patent Application Laid-Open No. 5-104115 discloses that an actual roll profile measured by a detector that measures the roll profile in contact with the outer periphery of a rolling roll and a target calculated to be an optimum roll profile that matches rolling conditions. A method for grinding a rolling roll online based on the roll profile is disclosed.

[0004]

However, in the above-mentioned method for grasping the position and the amount of wear of the step of the rolling roll based on the prediction calculation result, the amount of wear of the rolling roll depends on the type of rolling material and rolling conditions. Changes greatly,
There is a problem that the error increases when grinding is performed using the result of the prediction calculation.

In the method disclosed in the above-mentioned Japanese Patent Application Laid-Open No. 5-104115, not only the step wear of the rolling roll but also the portion of the thermal crown expanded by the thermal expansion in contact with the hot rolled material is ground. There is a problem. In other words, the roll profile as shown in FIG. 13 measured by the roll profile measuring device includes an initial crown of a roll as shown in FIG. 14 (a shape to be processed into a roll at the time of roll change) and a thermal as shown in FIG. The crown and the step wear as shown in FIG. 16 are combined, and furthermore, while the rolled material is being caught, the mechanical deformation of the rolling roll as shown in FIG. 17 is further added thereto. The roll grinder is intended to grind the stepped portion due to the roll abrasion (the portion hatched in FIGS. 13 and 16). However, in the conventional method, only the stepped portion due to the roll abrasion can be extracted. could not.
That is, if the step portion D in FIG. 16 cannot be detected accurately and, for example, the expanded portion S of the thermal crown in FIG. 15 is ground by mistake, the grinding will be performed when the temperature of the rolling roll decreases and the thermal crown decreases. There is a problem that the portion that has been recessed.

The present invention has been made in view of the above-mentioned conventional problems, and accurately detects the position of the step wear of the rolling roll, and eliminates the step of the rolling roll without grinding the uneven shape due to the thermal crown of the rolling roll. It is an object of the present invention to provide a method for grinding a rolling roll that can accurately grind only a worn portion.

[0007]

According to the present invention, there is provided a method of grinding a roll roll, wherein the roll profile of the roll is measured online and the roll is ground online based on the measurement result. Only a high-frequency component is extracted from a high-pass filter, and the extracted high-frequency component is compared with a predetermined threshold. This problem has been solved by grinding a portion from the position of the step wear to the end in the roll longitudinal direction.

The present invention also relates to a method for grinding a roll, wherein the roll profile of the roll is measured online and the roll is ground online based on the measurement result. Only the component is extracted, the extracted high-frequency component is differentiated, the differentiated result is compared with a predetermined threshold, and the position where the differentiated result exceeds the threshold is regarded as the position of the step wear of the rolling roll, This problem is also solved by grinding a portion between the position of the step wear on the rolling roll and the end in the roll longitudinal direction.

According to the present invention, only the high frequency component is extracted from the roll profile measurement result by the high-pass filter, and the high frequency component is compared with a predetermined threshold to detect the position of the step wear of the rolling roll. .
This means that the initial crown and the thermal crown or the mechanical bending shape of the rolling roll are all low-frequency components represented by low-order polynomials, whereas the step wear of the rolling roll is a steep high-frequency component. It focuses on that.

If the position of the step wear cannot be detected accurately only by comparing the high frequency component with a predetermined threshold value,
By differentiating the high-frequency component and comparing the differentiated result with a predetermined threshold, the position of the step wear of the rolling roll is detected. Differentiating the high-frequency component in this way emphasizes the stepped wear portion, which is the high-frequency component, to make it easier to distinguish it from the thermal crown, etc., and at the same time the thermal crown becomes convex at the center of the roll. On the other hand, this is a process for preventing a steep thermal crown change portion from being erroneously recognized as step wear by utilizing the characteristic that the step wear becomes concave at the center of the roll.

As described above, according to the present invention, the position of the rolling roll step wear is accurately detected by using the high frequency component of the profile measurement result of the rolling roll or the result of differentiating the high frequency component, and only the step portion is ground. can do.

[0012]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 is a flowchart showing a roll grinding method according to an embodiment of the present invention. Hereinafter, the present embodiment will be described with reference to the flowchart of FIG.

First, in step 100, the roll profile m is measured by a roll profile measuring device.
Measure (x). Measured roll profile m
FIG. 2 shows an example of (x). Here, x is a coordinate in the rolling roll axis direction. As a roll profile measuring device,
Although not particularly limited, for example, a water column type ultrasonic distance meter is suitable.

Next, in step 110, a high-pass filter (HPF) process is performed on the roll profile m (x) to obtain a high-frequency component M of the roll profile m (x).
(X) is extracted. As described above, in this treatment, the initial crown and the thermal crown of the roll or the mechanical bending shape are all low-frequency components represented by a low-order polynomial, while the step wear of the roll is small. The focus is on the steep high frequency components.
As a result, in the high frequency component M (x), the components of the initial crown, the thermal crown, and the mechanical bending shape are reduced, and the roll profile change due to the step wear becomes dominant.

Note that a general digital signal processing operation can be used as the high-pass filter. FIG. 3 shows the extracted high frequency component M (x).

Next, at step 120, M (x), which is a high frequency component of the roll profile m (x), is differentiated along the x-axis to obtain M '(x). This process emphasizes the step wear portion, which is a high-frequency component, to make it easier to distinguish it from the thermal crown, etc., and at the same time, the thermal crown becomes convex at the center of the roll, while the step wear is increased at the center of the roll. This is a process for preventing a steep thermal crown change portion from being erroneously recognized as stepped wear by utilizing the characteristic that the surface becomes concave.

That is, in the left part of the rolling roll, M ′ (x)> 0 due to the thermal crown change.
In the step wear portion, M ′ (x) <0. On the right side of the rolling roll, M '
(X) <0, whereas M ′ in the step wear portion
(X)> 0. FIG. 4 shows M ′ (x) as a result of differentiation.
Is shown.

Next, at step 130, the position of the step wear and the wear amount δ as shown in FIG. 2 are detected. That is,
As shown in FIG. 4, with respect to a preset threshold value T2 (> 0), M '(x) <0 and | M' in the left portion of the rolling roll.
The position of step wear is detected as a position P where (x) |> T2 and a position Q where M ′ (x)> 0 and | M ′ (x) |> T2 on the right side of the rolling roll. The wear amount (step amount) δ in the vicinity of the position of the detected step wear can be obtained as follows. For example, the amount of wear (step difference) near the step wear position on the left side of the rolling roll
When δ is determined, the position x1 in the roll axis direction of the point where the high frequency component M (x) of m (x) falls below the threshold value T1 is determined for the left portion of the rolling roll in FIG. Then, a position x2 where M (x) is minimum and a position x3 which is on the left side of x2 and where M (x) is maximum are obtained. m (x3
) And m (x2) can be obtained as δ.

Note that, as shown in FIG.
By comparing the high frequency component M (x) of the roll profile m (x) extracted in 10 with a threshold value T1,
If the position of the step wear of the rolling roll can be detected, the position of the step wear may be directly obtained from the high frequency component M (x) without calculating M ′ (x) in step 120.

Next, at step 140, as shown by R in FIG. 2, when the stepped wear is located outside the position of the detected stepped wear, for example, on the left side of the roll, the area R between the position and the left end of the roll is determined. Is ground by a depth δ with a roll grinding device.

As described above, according to this embodiment, it is possible to accurately detect the stepped portion of the rolling roll, and to accurately detect only the stepped portion of the rolling roll without grinding the uneven shape due to the thermal crown of the rolling roll. Can be ground.

As shown in FIG. 3, in some cases, the step wear portion can be detected only by the high frequency component M (x) of the roll profile m (x), but only by the high frequency component M (x). There is also a case where the step wear portion is erroneously detected. For example, as shown in FIG. 5, a roll profile m (x) of only a thermal crown without step wear.
, When the same processing is performed, as shown in FIG. 6, the high frequency component M (x) of the roll profile m (x)
Is found, there is a portion exceeding the threshold T1, but as shown in FIG. 7, when the high-frequency component M (x) is differentiated and compared with the threshold T2, there is no portion exceeding the threshold T2 and there is no step wear. I can see clearly. Therefore, in this case, if it is attempted to detect only the high-frequency component M (x) as shown in FIG. 6, as shown in FIG. 5, as shown in FIG. However, such a problem can be solved by adding a differential.

[0024]

EXAMPLES Hereinafter, more specific examples will be described.

FIG. 8 is a simulation result assuming a case where there is only a step wear with a depth of 15 μm at the center of a roll having a length of 2000 mm.

In FIG. 8, m (x) is a roll profile detected as discrete data at intervals of 10 mm, and m ^* (x) is a profile obtained by smoothing this m (x) by calculating a moving average of 9 points. is there. A high-pass filter process is performed by subtracting the smoothed profile m ^* (x) from the detected roll profile m (x) to obtain a high-frequency component M (x). That is, the high frequency component M
(X) is calculated by the following equation (1).

M (x) = m (x) −m ^* (x) (1)

The high frequency component M thus obtained
FIG. 9 shows (x).

Next, the high frequency component M (x) is differentiated by the following equation (2) on the left side of the rolling roll and by the following equation (3) on the right side of the rolling roll.

M ′ (10 × i) = M (10 × (i + 1)) − M (10 × i) (0 ≦ i ≦ 100) (2) M ′ (10 × i) = M (10 × ( i-1))-M (10 × i) (101 ≦ i ≦ 200) (3)

As described above, since the pulling method at the time of differentiating the right and left sides of the roll is reversed, as shown in FIG. 10, the step wear portion is detected on the minus side of M '(x). become.

FIG. 11 shows an example for actual measurement data of a roll profile in which a roll wear having a length of 2000 mm and an initial crown of 100 μm has a step wear, a thermal crown, and a mechanical roll deflection. Again, like the data in FIG. 8, the profile measurement result is discrete data at 10 mm intervals. For this, the same high-pass filter processing as in the embodiment shown in FIG. 8 is performed. In the above embodiment, the high-frequency component M
Since the expression (2) was applied over the entire range of the roll when differentiating (x), the appearance of the step component was different between the left side and the right side of the roll as shown in FIG. High-frequency component M (x)
When differentiating the roll, the roll (2)
Since the equation and the equation (3) are selectively used, as shown in FIG. 12, the step wear portion is detected on the minus side of M ′ (x) obtained by differentiating the high frequency component, as shown in FIG. By differentiating in this manner, the detection of the stepped wear portion becomes easy.

According to the present embodiment, as shown in FIGS. 10 and 12, it was confirmed that the step wear portion can be separated and extracted from the initial crown, the thermal crown, and the mechanical bending shape of the roll by an appropriate threshold value T2. Was done.

[0034]

As described above, according to the present invention,
By differentiating the high frequency component of the roll roll profile measurement result, the roll step wear part is detected, and only this step part is ground by the roll grinding device, so the roll step wear part can be accurately detected, It has become possible to accurately grind only the roll step wear portion without grinding the uneven shape due to the thermal crown of the roll.

[Brief description of the drawings]

FIG. 1 is a flowchart showing a method for grinding a rolling roll according to an embodiment of the present invention.

FIG. 2 is a diagram showing a roll profile in which a roll is subjected to step wear, thermal crown, and mechanical roll deflection.

FIG. 3 is a diagram showing high-frequency components of the roll profile of FIG. 2;

FIG. 4 is a diagram showing a derivative of the high-frequency component of FIG. 3;

FIG. 5 is a diagram showing a roll profile of only a thermal crown without step wear.

FIG. 6 is a diagram showing high-frequency components of the roll profile of FIG. 5;

FIG. 7 is a diagram showing a derivative of the high-frequency component of FIG. 6;

FIG. 8 is a diagram showing a simulation result assuming a case where there is only step wear at the center of the rolling roll.

FIG. 9 is a diagram showing high frequency components of the roll profile of FIG. 8;

FIG. 10 is a diagram showing a derivative of the high-frequency component of FIG. 9;

FIG. 11: Step wear, thermal crown,
Diagram showing a roll profile with mechanical roll deflection

FIG. 12 is a diagram showing a case where the differentiating method is changed between the right side and the left side of the roll with respect to the high frequency component of the roll profile of FIG. 2;

FIG. 13 is a diagram showing an example of a roll profile including step wear.

FIG. 14 is a diagram showing a shape of an initial crown.

FIG. 15 is a diagram showing the shape of a thermal crown;

FIG. 16 is a diagram showing the shape of step wear.

FIG. 17 is a diagram showing the mechanical deflection shape of a roll during rolling;

Claims (2)

[Claims] 1. A method for grinding a roll, wherein a roll profile of the roll is measured online, and the roll is ground online based on the measurement result. The extracted high-frequency component is compared with a predetermined threshold, and a position at which the high-frequency component exceeds the threshold is regarded as a position of the step wear of the rolling roll, and the position of the step wear on the rolling roll is determined based on the position of the step wear. A method for grinding a rolling roll, wherein a portion up to a longitudinal end is ground. 2. A method for grinding a roll, wherein the roll profile of the roll is measured online and the roll is ground online based on the measurement result. Extracting, differentiating the extracted high-frequency component, comparing the differentiated result with a predetermined threshold value, and setting the position where the differentiated result exceeds the threshold value as the position of the step wear of the rolling roll, and A method for grinding a rolling roll, characterized by grinding a portion between the upper step wear position and the end in the roll longitudinal direction.