JPH11248604A - Device and method for forecasting roll fusion in cold rolling mill - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable forecasting of generation of a roll fusion by monitoring whether the roll temperature increase at a portion of a cold rolling mill where the roll fusion is liable to occur, is not less than a specified value, or the temperature increase per unit time is not less than a specified value, or the temperature difference between a high roll temperature portion and a low roll temperature portion is not less than a specified temperature difference, or not. SOLUTION: At the time of cold control rolling operation, in the case, e.g., a six-roll type rolling mill performing dry rolling, work rolls 1, 1, intermediate rolls 2, 2 and backup rolls 3, 3 are arranged with a material S to be rolled which passes through a pass line P interposed therebetween. Non-contact type temperature sensors 4, 4 are provided for the rolls 2, 2 and temperature signals sensed thereby are output to a fusion monitoring unit 5 continuously or every specified time interval. In the unit 5, a specified fusion limit temperature is preliminarily set which is higher than a stable operation temperature and lower than a fusion generation temperature. The unit 5 receives an input of sensed temperature from the sensor 4 and compares it with the limit temperature, and when it is higher than the limit temperature, an alarm means 6 outputs an alarm signal. Accordingly, the rolling mill can stopped before its roll is fused and damaged so that the replacement thereof is made.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is to prevent the occurrence of erosion of rolling rolls (work rolls, intermediate rolls, and backup rolls; hereinafter the same) in a cold rolling mill (including a temper rolling mill). The present invention relates to a roll erosion prediction method and apparatus for monitoring roll rolls during cold rolling operation to prevent the occurrence of erosion. Particularly, the present invention relates to dry rolling in which erosion is likely to occur. Rolling without supplying a cooling agent and a cooling agent) is effective.

[0002]

2. Description of the Related Art In cold rolling, a phenomenon called so-called erosion may occur in which a part of a roll is locally melted and damaged during a rolling operation. There are few cases where this phenomenon called erosion occurs several times a year, and the frequency of occurrence itself is not so high. However, if erosion of the rolls occurs during the rolling operation, not only will the rolls be damaged, the operation will not be possible, but also the fire due to scattering of the molten roll material and ignition of the metal powder in the rolling mill will be a concern. It is worthwhile to be able to prevent or predict erosion, since it can cause serious damage to the product.

[0003] However, erosion occurs suddenly without any notice, and rarely occurs continuously. Thus, the mechanism of erosion has not been elucidated. It may be due to a slight increase in temperature, such as frictional heating with other rolls that come into contact, or the incorporation of metal powder (such as dull powder) into this contact area. It is only speculated that this phenomenon does not sufficiently explain the phenomenon in which the temperature of the roll becomes so high that a part of the roll is melted in cold rolling.

[0004] In any case, since the phenomenon is some kind of overheating, cooling of the roll can be considered as a measure against melting. However, in cold rolling, there is a case where rolling without using lubricants and cooling agents called dry rolling is performed in order to avoid contamination on the surface of the material to be rolled (typically, dry tempering rolling of steel strips or the like). In this dry rolling, it is difficult to cool the rolls, and the friction between the rolls and between the rolls and the metal powder tends to increase.

Therefore, conventionally, in order to prevent erosion or suppress roll damage, only countermeasures such as using a roll material having high abrasion resistance or a high hardness are used.

[0006]

However, from the viewpoint of preventing roll erosion, measures to adopt a material having a high abrasion resistance or a material having a high hardness as the material of the roll have been employed. Even if the life is slightly extended, there is a problem that the occurrence of melt damage cannot be sufficiently suppressed, and there is a problem that the test area has not been left out, and roll melt damage cannot be predicted.

Further, monitoring of the occurrence of roll erosion has not been conventionally performed. In addition,
As described in JP-A-63-20109, the roll temperature is conventionally measured in hot rolling or the like, but the purpose of this temperature measurement is to control the roll crown. This is not related to the object of the present invention, and does not particularly focus on the roll temperature measurement site other than the position in the roll axis direction.
However, the temperature measuring device and method itself can be applied to the present invention.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has as its object to predict the occurrence of roll erosion.

[0009]

According to a first aspect of the present invention, there is provided a roll erosion prediction method according to the present invention, wherein at least roll erosion is likely to occur in a roll of a cold rolling mill. The present invention is characterized in that occurrence of roll erosion is predicted based on a roll temperature of a part.

The inventors of the present application have found that, in dry rolling in a dry temper rolling mill (temper rolling mill to which dry rolling is sometimes applied), a portion where erosion occurs frequently is located at the axial end side of the roll. Noting that there is, and from the presumed cause such as friction, based on the prediction that the contact part between the rolls and its vicinity may be the starting point, the part where the contact between the rolls and the vicinity of it When the temperature in the vicinity of the end portion in the roll axis direction was continuously monitored, it was found that the temperature was higher in the relevant portion than in the other portions even if no erosion occurred.

Based on this finding, the present invention monitors at least a portion where roll erosion is likely to occur and predicts the occurrence of erosion. Here, during the operation, when the temperature of the portion where the erosion is likely to occur is measured, as shown by a white circle in FIG. 1, the temperature is slightly higher than the other portions even in the state where no erosion occurs. Not the temperature level at which the rolls actually melt away. However, from the results of continuous monitoring of the temperature, it has been confirmed that, in a portion where erosion is likely to occur, the temperature gradually rises and then suddenly rises suddenly to cause erosion.

In FIG. 1, a black circle indicates a temperature distribution immediately before the occurrence of erosion. Even at the temperature immediately before the occurrence of melting damage, the temperature is much lower than the melting temperature of the roll material. However, in the example of FIG.
If the temperature exceeds, it can be determined that rapid overheating is already in the starting stage.

From the above, it can be seen that the prediction of the occurrence of roll erosion can be determined by monitoring the temperature of the portion where roll erosion is likely to occur. Here, as a guide of the melting damage determination, whether the temperature of a portion where roll melting is likely to occur is equal to or higher than a predetermined value, or whether the temperature increase per unit time in the portion is equal to or higher than a predetermined temperature increasing value. Or, for example, in a temperature distribution in the roll axis direction, a temperature difference between a portion having a high roll temperature (a portion where roll erosion is likely to occur) and a portion having a low roll temperature (a portion where roll erosion is unlikely to occur) is equal to or higher than a predetermined temperature. Or
Etc. are preferred.

The invention described in any one of claims 1 to 8 has been made based on this. Next, the apparatus for predicting roll damage in a cold rolling mill according to claim 2 is a roll temperature measuring means for measuring the temperature of the roll in a portion of the cold rolling mill where roll damage is likely to occur, and And melting means for judging that there is a danger of melting when the temperature measured by the temperature measuring means exceeds a predetermined dangerous temperature.

Next, a third aspect of the present invention is to provide a cold rolling mill, comprising: a roll temperature measuring means for measuring a temperature of a roll at a portion where roll erosion is likely to occur; And a melting temperature judging means for judging that there is a danger of melting when the temperature rise per unit time exceeds a predetermined risk value.

According to the present invention, the erosion is predicted on the basis of a change in temperature (temperature rise). It is possible to reduce the error due to the difference.

Next, a fourth aspect of the present invention provides a roll temperature measuring means for measuring the temperature of a roll in a portion of a cold rolling mill where roll erosion is likely to occur and a portion where roll erosion is unlikely to occur. There is a danger of erosion when the difference between the measured temperature at the site where roll erosion is likely to occur and the measurement temperature at the site where roll erosion is less likely to be measured by the roll temperature measuring means exceeds a predetermined dangerous temperature difference. Erosion determining means for determining that

According to the present invention, since the determination is made based on the relative temperature difference between the part where the roll erosion is likely to occur and the part where the roll erosion is unlikely, the atmosphere and the material of the roll are compared with the invention according to the second aspect. It is possible to reduce an error due to the difference between the above.

The measuring means for measuring the temperature of the roll at the portion where the erosion of the roll is likely to occur and the temperature of the roll at the portion where the erosion of the roll hardly occurs is one temperature measuring means (at once or alternately). (Measuring the temperatures of these parts) or a plurality of temperature measuring means.

Next, a fifth aspect of the present invention is a roll temperature measuring means for measuring a temperature of a roll in a portion of a cold rolling mill where roll erosion is likely to occur and a portion where roll erosion is unlikely to occur. And, the respective measured temperatures measured by the roll temperature measuring means are continuously inputted, and the temperature rise per unit time is calculated, and the temperature rise and the occurrence of roll melting at a part where roll melting is likely to occur are calculated. A melting loss determining means for determining that there is a danger of melting when a difference from a temperature rise in a difficult part exceeds a predetermined dangerous temperature rise difference.

The present invention predicts erosion based on a relative difference in temperature change (temperature rise) between a portion where roll erosion is likely to occur and a portion where roll erosion is unlikely. As compared with the inventions described in the items 2 to 4, it is possible to further reduce errors due to differences in atmosphere, roll material, and the like.

According to a sixth aspect of the present invention, in the above-described configuration, the roll portion where the roll erosion is likely to occur is in contact with another roll which is in contact with the roll. And the vicinity thereof, and in the roll axis direction, the boundary portion and the vicinity where the contact state changes from a contact state to another contacting roll to a non-contact state.

The present invention is based on the knowledge obtained in the case of dry rolling. In the case of dry rolling, the position in the roll axis direction is equal to the taper start position (referred to as a tapered shoulder portion) of the end of the other roll in contact. The part where the rolls contact each other and the vicinity thereof.

Next, the invention according to claim 7 is characterized in that the cold rolling mill is a dry temper rolling mill, in addition to the configuration according to any of claims 2 to 6. It is.

The present invention has been made in view of the fact that dry rolling tends to cause erosion. Next, the invention described in claim 8 is characterized in that the roll whose temperature is to be measured by the roll temperature measuring means is an intermediate roll in the configuration according to any one of claims 2 to 7. It is.

Monitoring for erosion of the intermediate rolls, since erosion is most likely to occur on intermediate rolls that are always in contact with two or more rolls and often contact the tapered shoulders of other rolls, It was done.

[0027]

Next, an embodiment of the present invention will be described with reference to the drawings. In the present embodiment, a 6-roll rolling mill in which a cold temper rolling operation is performed by dry rolling will be described as an example.

That is, as shown in FIG. 2, the rolling mill according to the present embodiment includes a work roll 1, an intermediate roll 2, and a work roll 1 above and below a rolling material (here, a steel strip) S passing through a pass line P. The backup roll 3 is arranged and configured.

In the present embodiment, a non-contact type temperature sensor 4 is provided for each of the upper and lower intermediate rolls 2 for measuring the temperature of a portion of the roll 2 where melting of the rolls 2 is likely to occur. The temperature sensor 4 transmits the measured temperature signal continuously or at predetermined time intervals to the erosion monitoring device 5.
To supply.

Here, the temperature sensor 4 constitutes a means for measuring the roll temperature, and comprises, for example, an infrared sensor. The temperature sensor 4 may be of a contact type, but is preferably of a non-contact type in consideration of prevention of scratches and dirt on the roll surface.

The temperature measurement position by the temperature sensor 4 is as follows:
This is a site where roll erosion is likely to occur. A portion where roll erosion is likely to occur is known in advance, and in the case of dry rolling, as shown in part A in FIG. In the contact portion, a boundary portion where contact with the work roll 1 and the backup roll 3 changes to non-contact in the roll axis direction, for example, the work roll 1
And a portion in contact with the shoulder of the backup roll (the portion where the taper formed at the end starts). In more detail, it seems that erosion occurs at a portion slightly closer to the end portion than the contact portion and which does not contact due to bending of the roll, and it is estimated that friction heat generated at this portion is large. .

Since the roll is rotating at high speed,
The part B at the same axial position also has a temperature slightly lower than the part A, but shows almost the same high temperature. Therefore, this part may be used as the measurement part. This is a site where melting is likely to occur)). Further, when the shoulder portion of the work roll and the shoulder portion of the backup roll are separated from each other in the roll axis direction, the portions where erosion is likely to occur are as shown in FIG.

The temperature sensor 4 may measure the temperature by directly aiming at a portion where melting is likely to occur, or detect a range including the portion A (or the portion B in some cases) in FIG. 3 as a two-dimensional temperature distribution. The temperature of the part showing the highest temperature in the measurement range (usually in part A or B)
The roll temperature may be set to a temperature at which the erosion is likely to occur. In the examples of FIGS. 3 and 4, for example, it is preferable to measure a two-dimensional temperature distribution in a region C surrounded by a broken line.

The erosion monitoring device 5 (evaluation means for erosion) is provided with a predetermined danger temperature for erosion (for example, 100 degrees) which is higher than the temperature during stable operation and lower than the temperature at which erosion occurs.
° C) is set.

The erosion monitoring device 5 inputs the measured temperature from the temperature sensor 4 and compares the measured temperature with the erosion dangerous temperature.
An alarm signal is supplied to the alarm means 6.

The alarm means 6 may be a monitor, an alarm lamp, a speaker, or the like. When the alarm signal is input, for example, the number of a roll that may cause erosion is displayed on the monitor.

In the apparatus having the above-described structure, the rolling operation is performed while monitoring the temperature of the portion (A portion, and in some cases, B portion) where the erosion is likely to occur in the intermediate roll 2 where the erosion is likely to occur. .

When the above temperature becomes equal to or higher than the danger temperature for erosion, the erosion monitoring device 5 judges that there is a danger of erosion and alerts the operator through the alarm means 6. By this means, it is possible to stop the rolling mill and take measures such as changing rolls before melt damage actually occurs and the rolls are damaged, and it is possible to prevent the rolls from being damaged and to shorten the equipment downtime.

Here, in the above configuration, only an alarm is issued, but an interlock mechanism for stopping the rolling mill in conjunction with the controller of the rolling mill may be provided. In addition, since the above-mentioned rolling operation is dry rolling, it is difficult to take means for cooling the roll, but if not dry rolling,
Along with the warning, the roll may be cooled to suppress melting.

Next, a second embodiment will be described. The basic configuration of this embodiment is the same as that of the above-described first embodiment, except that the determination process in the erosion monitoring device 5 is different.
That is, in the erosion monitoring device 5 of the present embodiment, the temperature sensor 4
The measured temperature is input continuously or at a predetermined time interval from a predetermined time interval, and the temperature rise between the newly input current measured temperature and the previously input measured temperature is obtained, and the temperature rise is calculated. When it is determined that the minute is greater than a predetermined temperature rise value (for example, 30 ° C. per second), an alarm signal is supplied to the alarm means 6 as a danger of melting.

This method utilizes the fact that a certain degree of temperature rise occurs before a sharp temperature rise occurs and melts. In order to increase the accuracy of the determination, it may be determined that there is a danger of melting for the first time when the determination that the temperature rise is greater than the predetermined temperature rise value is made a plurality of times in succession. If the temperature rise is equal to or greater than the predetermined temperature increase value and the change in the increase is equal to or greater than the predetermined value, it may be determined that there is a risk of melting.

Other structures, operations and effects are the same as those of the first embodiment. Next, a third embodiment will be described. The basic configuration of this embodiment is the same as that of the first embodiment. However, the temperature sensor 4 is provided with a first temperature sensor for measuring the portion A (or the portion B) where roll melting is likely to occur, and a portion where roll melting is less likely to occur, for example, a central portion in the roll axis direction (see FIG. 3). , Symbol D). Note that the first temperature sensor and the second temperature sensor may be shared by one temperature sensor. In this case, for example, a method of measuring a two-dimensional temperature distribution in a region including the part A and the part D, or alternately measuring the temperature of the part A and the part D can be used.

Further, the erosion monitoring device 5 obtains a temperature difference by subtracting the manually measured temperature from the second temperature sensor from the measured temperature input from the first temperature sensor, and determines the temperature difference. When the temperature difference is equal to or higher than the critical temperature difference (for example, 50 ° C.), a warning signal is supplied to the warning means 6 as a risk of melting.

This is based on the fact that, as can be seen from FIG. 1, in the case where erosion occurs, the temperature difference between the portion where roll erosion is unlikely to occur and the portion where roll erosion is likely to occur becomes large. It is.

The above-mentioned predetermined dangerous temperature is a temperature lower than the temperature difference when melting occurs. Also, as in the second embodiment, instead of the temperature difference, the temperature rise per predetermined time is obtained for the input from the first temperature sensor and the input from the second temperature sensor, and the difference is equal to or more than a predetermined value. (For example, 30 ° C.), it may be determined that there is a danger of melting.

Further, the temperature distribution is measured not only at the center and the shoulder of the roll but also in the entire axial direction of the roll. May be determined to be in danger of melting if the temperature difference from the temperature is equal to or higher than a predetermined critical temperature. Even in this case, the location where the maximum temperature is reached (regardless of whether it is known in advance) should be positioned as a location where erosion is likely to occur.

The other structure, operation and effect are the same as those of the first embodiment. Further, the prediction determination of the occurrence of erosion in the erosion monitoring device 5 may be performed by appropriately combining the respective determinations described in the above embodiments.

Although the above embodiment has been described with reference to a six-roll rolling mill, the present invention is also applicable to rolling mills having other roll configurations such as a four-roll rolling mill. Instead, the temperatures of the work roll 1 and the backup floor 3 may be measured and monitored.
However, since erosion is likely to occur in the intermediate roll, it is most significant to monitor the erosion of the intermediate roll 2.

Further, in the above embodiment, the case of dry rolling is described as an example. Therefore, the portion where roll erosion is likely to occur is the shoulder portion A. What is necessary is just to determine the site where roll erosion is likely to occur according to the conditions. However, when measuring the temperature in the entire roll axis direction, it is not necessary to determine in advance the locations where roll erosion is likely to occur.

On the other hand, if a part where roll erosion is likely to occur is known, the temperature measurement part is limited.
The device configuration is simplified.

[0051]

As described above, when the present invention is employed, the occurrence of erosion can be detected in advance, and measures such as changing rolls can be performed before losses such as damage to rolls and loss of equipment occur. This has the effect of becoming In particular, it is effective for dry rolling as in the invention described in claim 7.

At this time, if the invention described in claim 2 is adopted, the erosion can be predicted from the absolute temperature of the roll. Further, by adopting the invention of claim 3, it is possible to predict erosion based on a temperature change (temperature rise), and to reduce errors due to differences in ambient temperature, roll material and the like as compared with the invention of claim 2. Becomes possible.

Further, when the invention described in claim 4 is adopted, since the determination is made based on the relative temperature difference, errors due to differences in ambient temperature, roll material, and the like are reduced as compared with the invention described in claim 2. It becomes possible.

Further, when the invention described in claim 5 is adopted, erosion can be predicted on the basis of a relative difference in temperature change (temperature rise), and compared with the inventions described in claims 2 to 4. ,
It is possible to further reduce errors due to differences in atmosphere, roll material, and the like.

Further, when the invention described in claim 8 is adopted, the intermediate roll in which the most erosion occurs in the rolling mill is monitored, so that the apparatus configuration for predicting the occurrence of erosion in the entire rolling mill is simplified. Becomes

[Brief description of the drawings]

FIG. 1 is a diagram showing a roll temperature distribution in a roll longitudinal direction in dry rolling.

FIG. 2 is a diagram showing a device configuration according to the embodiment of the present invention.

FIG. 3 is a diagram for explaining a portion where melting is likely to occur according to the embodiment of the present invention.

FIG. 4 is a diagram for explaining a portion in which erosion is likely to occur according to another embodiment of the present invention.

[Explanation of symbols]

 2 Intermediate roll 4 Temperature sensor 5 Melting monitoring device 6 Alarm means

Claims (8)

[Claims] 1. A method for predicting roll erosion in a cold rolling mill, wherein the roll erosion of a roll of a cold rolling mill is predicted based on at least a roll temperature at a portion where roll erosion is likely to occur. . 2. A roll temperature measuring means for measuring a temperature of a roll in a portion of a cold rolling mill where roll erosion is likely to occur, and a measured temperature measured by the roll temperature measuring means exceeds a predetermined dangerous temperature. A roll erosion predicting device for a cold rolling mill, comprising: a erosion determining unit that sometimes determines that there is a danger of erosion. 3. A roll temperature measuring means for measuring the temperature of a roll in a portion of a cold rolling mill where roll erosion is likely to occur, and a measurement temperature is continuously inputted from the roll temperature measuring means, and the temperature is measured per unit time. A roll damage predicting device for a cold rolling mill, comprising: a melt damage determining means for determining that there is a risk of melt damage when the temperature rise of the roll exceeds a predetermined risk value. 4. A roll temperature measuring means for measuring a temperature of a roll of a cold rolling mill at a portion where roll erosion is likely to occur and a portion where roll erosion is unlikely to occur, wherein the roll temperature is measured by the roll temperature measuring means. And a melt damage determining means for determining that there is a danger of melt damage when a difference between a measured temperature at a portion where roll melt damage is likely to occur and a measured temperature at a portion where roll melt damage is unlikely exceeds a predetermined dangerous temperature difference. A roll erosion prediction device for a cold rolling mill, comprising: 5. A roll temperature measuring means for measuring a temperature of a roll in a portion of a cold rolling mill in which roll erosion is likely to occur and a portion in which roll erosion is unlikely to occur, wherein the roll temperature is measured by the roll temperature measuring means. Each measured temperature is continuously input, and the temperature rise per unit time is calculated, and the difference between the temperature rise in the part where roll melting is likely to occur and the temperature rise in the part where roll melting is less likely is determined. A roll erosion predicting device for a cold rolling mill, comprising: a erosion determining means for determining that there is a danger of erosion when a difference in critical temperature rise is exceeded. 6. The roll portion where the roll erosion is liable to occur is at and near a contact portion with another roll in contact with the other roll, and is in a non-contact state from a contact state with another roll in contact in the roll axis direction. The roll erosion prediction device for a cold rolling mill according to any one of claims 2 to 5, wherein the boundary portion changes to a state and the vicinity thereof. 7. The roll erosion predicting device for a cold rolling mill according to claim 2, wherein the cold rolling mill is a dry temper rolling mill. 8. The roll erosion prediction device for a cold rolling mill according to claim 2, wherein the roll whose temperature is measured by the roll temperature measuring means is an intermediate roll.