JP2022068097A - Metal strip temperature measuring method, metal strip temperature measuring device, metal strip manufacturing method, metal strip manufacturing equipment, and metal strip quality control method - Google Patents

Abstract

To provide a metal strip temperature measuring method, a metal strip temperature measuring device, a metal strip manufacturing method, metal strip manufacturing equipment, and a metal strip quality control method, by which a temperature of a metal strip between two rolls can be measured in a simplified and highly-accurate manner.SOLUTION: Provided is a metal strip temperature measuring method for measuring a temperature of a metal strip between two rolls which are disposed with a gap in a conveying direction of the metal strip, and around which the metal strip coils. The method includes: a step for measuring a temperature of an upstream roll out of the two rolls by a thermocouple buried in the upstream roll positioned at an upstream in the conveying direction of the metal strip; a step for calculating radiance by measuring a portion of the upstream roll around which the metal strip coils, by a first radiation thermometer; a step for calculating an emissivity of the metal strip from the temperature measured by the thermocouple and the radiance; and a step for measuring a surface temperature of the metal strip at a measurement position set between the two rolls, by a second radiation thermometer using the emissivity.SELECTED DRAWING: Figure 1

Description

The present invention relates to a metal band temperature measuring method, a metal band temperature measuring device, a metal band manufacturing method, a metal band manufacturing facility, and a metal band quality control method.

Conventionally, in the manufacturing process of steel strips such as thin steel plates, temperature control of the steel strips is very important from the viewpoint of manufacturing the material. In particular, in the annealing process, there is a need to measure the temperature of the steel strip during transportation in order to control the steel strip to reach the target temperature in each step. A typical temperature measurement method includes radiance measurement in which the radiance of a steel strip is measured and the measured radiance is converted into temperature. However, if the emissivity of the steel strip is not known, the temperature cannot be measured correctly, and there is a problem in setting the emissivity of the steel strip whose surface texture changes significantly in the manufacturing process.

As a method capable of measuring the temperature regardless of the radiation coefficient of the metal strip, particularly the steel strip, for example, a method using a multiple reflection type radiation temperature measuring device as disclosed in Patent Document 1, Non-Patent Document 1 A method using a temperature measuring device of a temperature measuring roll type as disclosed in the above, and a method using a temperature measuring device equipped with a spectral main component radiation thermometer as disclosed in Patent Document 2. Can be mentioned. In the method using the multiple reflection type emissivity temperature measuring device, for example, as shown in FIG. 6, the field of view of the radiation thermometer 140 is a slight gap between the roll 120 around which the steel strip 110 is wound and the surface of the steel strip. By setting the above, the temperature of the steel strip 110 is measured in a state where the emissivity is close to 1.0 under a pseudo multiple reflection condition. Further, in the method using the temperature measuring device of the temperature measuring roll type, for example, as shown in FIG. 7, a plurality of thermocouples 131 are embedded in the roll 130 in the circumferential direction and wound around the roll 130 of the steel strip 110. By creating a condition in which the temperature of the roll 130 and the temperature of the steel strip are the same, the temperature of the steel strip 110 is measured by the thermocouple 131. Further, in the method using a temperature measuring device equipped with a spectral principal component radiation thermometer, the temperature of the steel strip is measured by using the spectral radiation of the steel strip and learning by the principal component analysis.

Tokusho 4-558568 Gazette Japanese Patent No. 5979065

Iron and Steel, 1993, vol. 79, No. 7, p. 765-771 Proceedings of the Society of Instrument and Control Engineers, 1982, vol. 18, No. 7, p. 704-709 JIS C 1612, general rules for performance test methods for radiation thermometers

The methods disclosed in Patent Document 1 and Non-Patent Document 1 are very powerful methods for accurately measuring the temperature of steel strips. However, it cannot be used unless the temperature of the roll and the steel strip is the same, and the steel strip must be sufficiently wrapped around the roll. The methods disclosed in Patent Document 1 and Non-Patent Document 1 cannot be used in a straight path between two arranged rolls. Further, the method disclosed in Patent Document 2 also requires a contact thermocouple in order to obtain the true value of the steel strip temperature, which requires a large-scale device and a large amount of data for learning. There are issues such as.

On the other hand, even in the straight path between rolls, there is a very important process in terms of temperature control, such as just before the steel strip temperature suddenly changes such as water quenching, and there is a strong need for temperature measurement. In particular, the temperature of the steel strip immediately before water quenching is extremely important in terms of material, but due to equipment restrictions, it is difficult to arrange a roll for winding the steel strip immediately before water quenching, so a roll was used. Temperature measurement cannot be applied.

The present invention has been made in view of the above problems, and an object thereof is a method for measuring the temperature of a metal band, which can easily and accurately measure the temperature of a metal band between two rolls, and the temperature of the metal band. It is to provide a measuring device, a method for manufacturing a metal band, a method for manufacturing a metal band, and a method for quality control of a metal band.

In order to solve the above-mentioned problems and achieve the object, the method for measuring the temperature of the metal band according to the present invention is to use two rolls around which the metal band is wound, which are arranged at intervals in the transport direction of the metal band. A method for measuring the temperature of the metal band, which measures the temperature of the metal band between the two rolls, by a thermocouple embedded in the upstream roll located on the upstream side in the transport direction of the metal band. The step of measuring the temperature of the upstream roll, the step of measuring the portion of the metal band wrapped around the upstream roll with a first radiation thermometer to obtain the radiation brightness, and the temperature measured by the thermocouple. The surface temperature of the metal band at the measurement position set between the two rolls by the step of calculating the radiation rate of the metal band from the radiation brightness and the second radiation thermometer using the radiation rate. It is characterized by having a step of measuring.

Further, in the above invention, the method for measuring the temperature of the metal band according to the present invention is the measurement position of the surface of the metal band by the first radiation thermometer in the transport direction of the metal band and the metal by the second radiation thermometer. Using the distance from the measurement position of the band surface and the transport speed of the metal band or the rotation speed of the upstream roll, the same location on the metal band surface is indicated by the first radiation thermometer and the second radiation thermometer. It is characterized by measuring by.

Further, the metal band temperature measuring device according to the present invention measures the surface temperature of the metal band between two rolls around which the metal band is wound, which are arranged at intervals in the transport direction of the metal band. A thermocouple that measures the temperature of the upstream roll, which is a device for measuring the temperature of the metal band and is embedded in the upstream roll located on the upstream side in the transport direction of the metal band, among the two rolls. From the first radiation thermometer that measures the portion of the metal band wrapped around the upstream roll, the temperature measured by the thermocouple, and the radiation brightness obtained from the measurement result of the first radiation thermocouple, the said A means for calculating the radiation rate of the metal band and a second radiation thermometer for measuring the surface temperature of the metal band at a measurement position set between the two rolls using the radiation rate are provided. It is characterized by.

Further, in the above invention, the metal band temperature measuring device according to the present invention has the measurement position of the metal band surface by the first radiation thermometer and the metal by the second radiation thermometer in the transport direction of the metal band. Using the distance from the measurement position of the band surface and the transport speed of the metal band or the rotation speed of the upstream roll, the same location on the metal band surface is indicated by the first radiation thermometer and the second radiation thermometer. It is characterized by measuring by.

Further, the method for manufacturing a metal band according to the present invention includes a metal band manufacturing step and a temperature measuring step for measuring the temperature of the metal band manufactured in the manufacturing step by the above-mentioned method for measuring the temperature of the metal band. , Is included.

Further, in the method for manufacturing a metal band according to the present invention, in the above invention, the temperature measurement step measures the temperature during transportation of the metal band, and the temperature measured in the temperature measurement step is used. It is characterized in that, among the steps included in the manufacturing step, the conditions of one or a plurality of steps after the temperature measuring step are controlled.

Further, the metal band manufacturing equipment according to the present invention includes a manufacturing equipment for manufacturing the metal band, a metal band temperature measuring device of the above invention for measuring the temperature of the metal band manufactured by the manufacturing equipment, and the above-mentioned metal band temperature measuring device. The manufacturing equipment is provided with a transport equipment having a roll for transporting the metal band, and the temperature measuring device is provided in the transport equipment.

Further, the quality control method of the metal band according to the present invention is based on the temperature measurement step of measuring the temperature of the metal band by the temperature measurement method of the metal band of the above invention and the temperature measurement result obtained by the temperature measurement step. , A quality control step for performing quality control of the metal band, and the like.

The metal band temperature measuring method, the metal band temperature measuring device, the metal band manufacturing method, the metal band manufacturing equipment, and the metal band quality control method according to the present invention determine the temperature of the metal band between two rolls. It has the effect of being able to measure easily and accurately.

FIG. 1 is a diagram showing a schematic configuration of a metal band temperature measuring device (as an example, a steel strip temperature measuring device) provided in a metal strip (steel strip as an example) manufacturing facility according to an embodiment. FIG. 2 is a graph showing an example of the calibration result of the first radiation thermometer. FIG. 3 is an explanatory diagram of the conventional feedback control. FIG. 4 is an explanatory diagram of feedforward control that can be implemented in the steel strip manufacturing equipment according to the embodiment. FIG. 5 is a graph showing the temperature measurement results of the examples. FIG. 6 is a diagram showing a schematic configuration of a temperature measuring device of a multiple reflection type radiation temperature type. FIG. 7 is a diagram showing a schematic configuration of a temperature measuring device of a temperature measuring roll type.

Hereinafter, embodiments of a metal band temperature measuring method, a metal band temperature measuring device, a metal band manufacturing method, a metal band manufacturing facility, and a metal band quality control method according to the present invention will be described. In this embodiment, a steel strip will be used as an example of the metal strip. That is, the metal strip manufacturing equipment will be described as an example of the steel strip manufacturing equipment, and the metal strip temperature measuring device will be described as an example of the steel strip temperature measuring device. Of course, the present invention is not limited to this embodiment as long as the effect of the invention is not impaired.

FIG. 1 is a diagram showing a schematic configuration of a steel strip temperature measuring device 1 provided in a steel strip manufacturing facility according to an embodiment.

The steel strip manufacturing equipment is equipped with the steel strip transport equipment described below. As shown in FIG. 1, the transport facility for the steel strip 10 according to the embodiment is provided with a lower transport roll 20, an upper transport roll 30, and a transport roll 80 for changing the transport direction of the steel strip 10 up and down. ing. The lower transport roll 20 rotates in the counterclockwise direction in FIG. 1, and transports the steel strip 10 wound around the lower transport roll 20 while changing the transport direction from sideways to upward. The upper transfer roll 30 is rotated clockwise in FIG. 1, is conveyed upward from the lower transfer roll 20, and is conveyed while changing the transfer direction of the steel strip 10 wound around the upper transfer roll 30 downward. .. On the downstream side of the upper transport roll 30 in the transport direction of the steel strip 10, for example, a quenching device 60 for quenching the steel strip 10 after annealing by an annealing furnace with cooling water is provided. In the steel strip 10 manufacturing equipment according to the embodiment, depending on the type of the steel strip 10 to be manufactured, the quenching device 60 is replaced with the quenching device 60 on the downstream side in the transport direction of the steel strip 10 from the upper transport roll 30. A heating device for heating the steel strip 10 may be provided. Further, a transport roll 80 around which the steel strip 10 is wound and transported is provided on the downstream side of the quenching device 60 in the transport direction of the steel strip 10. In the present embodiment, the upper transport roll 30 and the transport roll 80 are the two rolls of the present invention, the upper transport roll 30 corresponds to the upstream roll, and the transport roll 80 corresponds to the downstream roll.

Here, as can be seen from FIG. 1, immediately before the quenching device 60, there is only a vertical straight path 50 in which the steel strip 10 after being conveyed by the upper transfer roll 30 is not wound around the transfer roll. Moreover, in this straight path 50, there is a factor that the temperature of the steel strip 10 changes due to air cooling or the like during transportation. Therefore, the manufacturing facility for the steel strip 10 according to the embodiment includes a steel strip temperature measuring device 1 which is a temperature measuring device for measuring the temperature of the steel strip 10 immediately before the quenching device 60 in the transport facility for the steel strip 10. I have. The steel strip temperature measuring device 1 is composed of an upper transfer roll 30 in which a plurality of thermocouples 31 are embedded, a first radiation thermometer 41, a second radiation thermometer 42, a control device 70, and the like.

A plurality of thermocouples 31 are embedded in the upper transport roll 30 over the circumferential direction, and the upper transport roll 30 has a function as a temperature measuring roll. In the steel strip temperature measuring device 1 according to the embodiment, one or more thermocouples 31 may be embedded inside the upper transfer roll 30. Further, due to the nature of the upper transport roll 30, the temperature of the upper transport roll 30 heated by heat transfer from the steel strip 10 and the steel strip temperature must be the same, so that the steel is used with respect to the upper transport roll 30. It is desirable that the band 10 is wrapped around at least half a circumference.

The first radiation thermometer 41 is arranged so that the surface temperature at the portion wound around the upper transport roll 30 of the steel strip 10 can be measured. The measurement position _PA of the first radiation thermometer 41 is not particularly limited as long as it is a portion wound around the upper transport roll 30 of the steel strip 10. Further, in the steel strip temperature measuring device 1 according to the embodiment, one or more first radiation thermometers 41 for measuring the portion wound around the upper transport roll 30 of the steel strip 10 may be provided.

The second radiation thermometer 42 is arranged so that the surface temperature of the steel strip 10 at a position immediately before the quenching device 60 in the transport direction of the steel strip 10 can be measured. The measurement position P _B of the second radiation thermometer 42 is preferably as close as possible to the quenching device 60. Further, in the steel strip temperature measuring device 1 according to the embodiment, one or more second radiation thermometers 42 for measuring the surface temperature of the steel strip 10 may be provided at a position immediately before the quenching device 60.

The first radiation thermometer 41 and the second radiation thermometer 42 are arranged at predetermined intervals from the surface of the steel strip so as not to come into contact with the steel strip 10 being conveyed. At this time, the distance between the first radiation thermometer 41 and the second radiation thermometer 42 and the surface of the steel strip is within the circular spot diameters of the first radiation thermometer 41 and the second radiation thermometer 42, respectively. As long as the target area on the surface is settled, it is not limited to a specific one. Further, the first radiation thermometer 41 and the second radiation thermometer 42 are not limited to being arranged so as to be measurable at a position perpendicular to the steel strip surface as shown in FIG. 1, for example, the steel strip surface. It may be arranged so as to be measurable at a position inclined within a range of 60 [°] or less from a position perpendicular to the steel strip 10 to the upstream side or the downstream side in the transport direction.

The control device 70 calculates the emissivity ε using the measurement results of the first radiation thermometer 41 and the upper transport roll 30, and applies the calculated emissivity ε to the measurement of the second radiation thermometer 42. The steel strip temperature immediately before the quenching device 60 is calculated. Since the emissivity ε has a wavelength dependence, it is desirable that the first radiation thermometer 41 and the second radiation thermometer 42 have the same wavelength characteristics.

Further, in the manufacturing equipment for the steel strip 10 according to the embodiment, the surface texture of the steel strip 10 changes as much as possible between the measurement position _{PA of the first radiation thermometer 41 and the measurement position P B of} the second radiation thermometer 42. It is preferable not to do so.

Here, in the steel strip temperature measuring device 1 according to the embodiment, the first radiation thermometer 41 has a specification of outputting the radiation temperature as a measurement result and a specification of outputting the radiance brightness as a measurement result. , Both are applicable. Therefore, first, a case where the first radiation thermometer 41 outputs the radiation temperature as a measurement result will be described.

In the first radiation thermometer 41 having a specification of outputting the radiation temperature, the temperature of the steel strip 10 is measured by setting a certain emissivity ε. At this time, the emissivity ε to be set may be anything as long as it is known, but for convenience, it is set to 1.0. Then, the portion wound around the upper transport roll 30 of the steel strip 10 is measured by the first radiation thermometer 41 in which the emissivity ε is set in this way, and the radiation temperature _TA of the steel strip 10 is measured by the first radiation thermometer 41. Output as a measurement result. At this time, the temperature measured value measured by the thermocouple 31 of the upper transport roll 30 is defined as _Tr . In order to calculate the emissivity ε of the steel strip 10, it is necessary to compare the radiance when the emissivity ε is 1.0 (blackbody condition) with the actual radiance, so the obtained temperature. The value needs to be converted to a brightness value. The conversion formula used at this time is calculated in advance by calibration before installing the first radiation thermometer 41. The formula used for calibration may be a general polynomial or the like, but if accuracy is required, Sakuma Hattori's formula (see Non-Patent Document 2) represented by the following formula (1), which closely approximates Planck's formula, is used. ) Etc. are desirable, and Sakuma Hattori's formula is also used in this embodiment. As the calibration method of the first radiation thermometer 41, for example, the calibration method disclosed in Non-Patent Document 3 can be applied, and an example of the calibration result of the first radiation thermometer 41 is shown in FIG. As shown in FIG. 2, by calibrating the first radiation thermometer 41, a correlation is obtained between the temperature T and the output signal voltage V output by the first radiation thermometer 41. I understand. At this time, the unique parameters A, B, and C of the first radiation thermometer 41 are obtained, and the emissivity ε of the steel strip 10 is calculated using this parameter. In the following mathematical formula (1), c ₂ is the second constant of radiation.

The result of converting the temperature measurement value _Tr into the radiance S _r ( _Tr ) using the above formula (1) is shown in the following formula (2), and the radiation temperature _TA is converted into the radiance _SA ( _TA ). The converted result is shown in the following formula (3). If the emissivity ε is not set to 1.0 when measuring the radiation temperature _TA with the first radiation thermometer 41, the radiation is emitted at the emissivity ε set when measuring the radiation temperature _TA . The radiance _SA ( _TA ) is corrected by dividing the radiance _SA ( _TA ).

Since the emissivity ε is the ratio of the radiance S _r ( _Tr ) under the blackbody condition (result of converting the temperature measurement value _Tr ) to the actual radiance _SA ( _TA ), the following formula is used. It can be calculated in (4).

This time, using the formula of Sakuma Hattori, the conversion between the temperature measurement value Tr and the radiation temperature _TA and the _radiance S _r ( _Tr ), _SA ( _TA ) was performed, but the formula used for the conversion. The formula is not limited to Sakuma Hattori's formula, but other formulas are used to determine the temperature measurement value Tr and radiation temperature _TA , and the _radiance S _r ( _Tr ) and _SA ( _TA ). Similar results can be obtained by performing the conversion. Which formula to select for conversion between the temperature measurement value _Tr and the radiation temperature _TA and the radiance S _r ( _Tr ), _SA ( _TA ) depends on the calculation amount, accuracy, and radiation thermometer. An appropriate formula may be selected in consideration of the wavelength characteristics of the above.

Next, a case where the first radiation thermometer 41 outputs the radiance as a measurement result will be described. In the first radiation thermometer 41 having a specification of outputting the radiance as a measurement result, it is not necessary to convert the radiance temperature _TA into the radiance _SA ( _TA ) by the above formula (3). Therefore, the radiance _SA ( _TA ), which is the output result of the first radiation thermometer 41, is directly substituted into the above formula (4), and the temperature measurement value _Tr is converted by the above formula (2). The emissivity ε can be calculated by substituting _r ( _Tr ).

Then, by measuring the temperature of the steel strip 10 with the second radiation thermometer 42 using the calculated radiation rate ε, the radiation temperature _TB of the steel strip surface at the measurement position P _B of the second radiation thermometer 42 Can be obtained.

Further, the second radiation thermometer 42 does not need to be spot measurement, and the width direction of the steel strip surface or the width direction of the steel strip surface by applying the emissivity ε calculated by using an optical element having a two-dimensional field of view. The temperature distribution may be measured. Further, instead of the optical element having a field of view in the width direction of the steel strip surface, a spot thermometer may be scanned to measure the temperature distribution in the width direction of the steel strip surface. At this time, the surface texture and the emissivity ε may differ in the width direction of the steel strip surface due to variations in operating conditions in the width direction of the steel strip surface. When a specific emissivity ε is applied when the emissivity ε differs in the width direction of the steel strip surface, a region where the emissivity ε cannot be corrected correctly occurs, which leads to an error in the measured temperature. Therefore, even if the first radiation thermometer 41 is an optical element or spot thermometer having a two-dimensional field of view and the first radiation thermometer 41 is scanned, the temperature distribution in the width direction of the steel strip surface can be measured. good. Further, by embedding a plurality of thermocouples in the roll width direction, the emissivity distribution in the width direction of the steel strip surface may be calculated from the radiance and the thermocouple temperature value at the corresponding positions. By calculating the emissivity distribution in the width direction of the steel strip surface using the emissivity distribution in the width direction of the steel strip surface, even if there is a variation in the emissivity ε in the width direction of the steel strip surface, it does not matter at all measurement positions. It is possible to measure the temperature accurately.

In the transport direction of the steel strip 10, the measurement position _{PA of the first radiation thermometer 41 and the measurement position P B of} the second radiation thermometer 42 are separated from each other. At this time, when the surface texture and the emissivity ε are significantly different in the transport direction of the steel strip 10, such as before and after the welding point where the two steel strips 10 are welded and connected in the transport direction, the steel strip surface passes through. 1 There is a condition that the emissivity ε is different between the measurement position _PA of the radiation thermometer 41 and the measurement position P _B of the second radiation thermometer 42. When the emissivity ε calculated by the first radiation thermometer 41 is used under such conditions and the temperature is measured by the second radiation thermometer 42 at the same time, the emissivity ε itself due to the change in the surface texture of the steel strip 10. Is different, which may cause a temperature measurement error. Therefore, the position on the surface of the steel strip measured by the measurement position _PA of the first radiation thermometer 41 and the position on the surface of the steel strip measured by the measurement position _PB of the second radiation thermometer 42 are abbreviated. It is preferable to perform alignment so that they are the same. Then, for example, the transport speed of the steel strip 10 is set to v [m / s], and the measurement position _{PA of the first radiation thermometer 41 and the measurement position P B of} the second radiation thermometer 42 in the transport direction of the steel strip 10. Let L [m] be the distance between and. In this case, at the timing when the same location on the surface of the steel strip passes the measurement position _{PA of the first radiation thermometer 41 and the measurement position P B of} the second radiation thermometer 42, the first radiation thermometer 41 There is a delay of L / v [s] at the measurement position P _B of the second radiation thermometer 42 with respect to the measurement position P _A. Therefore, the emissivity ε used to calculate the radiation temperature _TB measured by the second radiation thermometer 42 is the radiation temperature _TA or radiation brightness S measured by the first radiation thermometer 41 before L / v [s]. The emissivity ε calculated by using _A ( _TA ) and the thermometer value _Tr measured by the thermometer 31 of the upper transport roll 30 may be used.

On the other hand, when the distance moved by the same place on the surface of the steel strip was calculated using the transport speed of the steel strip 10 and the alignment was performed, the temperature was measured at the measurement position _PA of the first radiation thermometer 41. There is a possibility that a positional deviation may occur between the position on the surface of the steel strip and the position on the surface of the steel strip measured by the measurement position _PB of the second radiation thermometer 42. The reason is that when the transport speed of the steel strip 10 is constant, the alignment can be performed accurately, but the same location on the surface of the steel strip is from the measurement position _PA of the first radiation thermometer 41 to the second radiation thermometer 42. Even if the transport speed of the steel strip 10 changes before reaching the measurement position _PB , the transport speed of the steel strip 10 is assumed to be constant. This is to calculate the distance traveled by the same location on the surface of the steel strip based on the product of time. Therefore, if more precise control is required, the transfer speed of the steel strip 10 is integrated over time to calculate the distance traveled by the same location on the steel strip surface, taking into consideration the change in the transport speed of the steel strip 10. , The position on the surface of the steel strip measured by the measurement position _{PA of the first radiation thermometer 41 and the position on the surface of the steel strip measured by the measurement position P B of} the second radiation thermometer 42 are substantially the same. It is more preferable to align the thermometer so as to be. Further, when the position on the steel strip surface is tracked by the rotation speed of the upper transport roll 30, the same location on the steel strip surface is measured by the first radiation thermometer 41 and the second radiation thermometer 42. From the tracking information, the position on the steel strip surface measured by the measurement position _{PA of the first radiation thermometer 41 and the position on the steel strip surface measured by the measurement position P B of} the second radiation thermometer 42. Alignment with the position may be performed and the distance moved by the same place on the surface of the steel strip may be calculated directly. In this way, the position on the steel strip surface measured by the measurement position PA of the first radiation thermometer 41 and the position on the steel _strip surface measured by the measurement position _PB of the second radiation thermometer 42 are aligned. By performing the above, the emissivity ε can be corrected for the same location on the steel strip surface without being affected by the emissivity fluctuation of the steel strip surface that may occur in the transport direction of the steel strip 10. , It is possible to measure the temperature with high accuracy.

Further, in the present embodiment, the second radiation thermometer 42 is arranged downstream in the transport direction of the steel strip 10 with respect to the first radiation thermometer 41 and the upper transport roll 30, but the first radiation thermometer Similar temperature measurement is possible even if the second radiation thermometer 42 is arranged upstream of the steel strip 10 in the transport direction with respect to the 41 and the upper transport roll 30. However, in this case, the radiation coefficient ε used in the second radiation thermometer 42 is obtained at the same location on the surface of the steel strip 10 measured by the second radiation thermometer 42 as the first with respect to the steel strip surface. After passing the measurement position _PA of the radiation thermometer 41. Therefore, for example, in the second radiation thermometer 42, the temperature is measured using a temporary emissivity ε, or the radiance is acquired, and the emissivity ε obtained later is used to obtain a correct temperature measurement result. Convert.

Further, even when the second radiation thermometer 42 is arranged upstream in the transport direction of the steel strip 10 with respect to the first radiation thermometer 41 and the upper transport roll 30, the same as described above, with respect to the steel strip surface. It is desirable to align the measurement position _{PA of the first radiation thermometer 41 with the measurement position P B of} the second radiation thermometer 42 with respect to the steel strip surface.

Here, conventionally, in a steel strip manufacturing facility, as shown in FIG. 3, the steel strip 110 after being rapidly cooled by the quenching device 160 is temperature-measured by a radiation thermometer 142, and the temperature measurement result and the temperature measurement result after quenching are measured. The control device 170 performs feedback control to feed back the difference from the target temperature of the steel strip 10 to the output of the quenching device 160 (for example, the amount of liquid injected toward the steel strip 10 per unit time), whereby the steel is made of steel. The temperature of the band 10 is controlled. However, in the feedback control, since the temperature of the steel strip 10 after quenching is actually measured and then the output of the quenching device 160 is adjusted by the control device 170, the responsiveness is inevitably lowered as compared with the feed forward control. Therefore, when steel strips with different manufacturing conditions such as temperature and thickness are continuously manufactured, the decrease in responsiveness before and after the manufacturing conditions change leads to an increase in the temperature defect region in the steel strip after quenching, resulting in a yield. To reduce.

Therefore, in the manufacturing equipment for the steel strip 10 according to the embodiment, as shown in FIG. 4, the emissivity ε calculated by using the above equation (4) and the transport speed of the steel strip 10 are v [m / s. ], The control device 70 predicts the temperature change until the same location on the surface of the steel strip measured by the first radiation thermometer 41 reaches the quenching device 60 by heat transfer calculation. Then, based on the predicted temperature change, the control device 70 performs feed-forward control for adjusting the output of the quenching device 60 (for example, the amount of liquid injected toward the steel strip 10 per unit time), and the steel strip is performed. 10 temperature control is carried out.

In order to improve the responsiveness of the temperature control of the steel strip 10, feed-forward control by temperature prediction is effective, but in the high temperature region such as the manufacturing process of the steel strip, the heat transfer is performed by the following formula (5). Radiation was dominant as represented by, and emissivity ε was particularly important.

Therefore, as in the steel strip temperature measuring device 1 according to the embodiment, the accuracy of the heat transfer model is improved by accurately estimating the emissivity ε, and the steel with high responsiveness is introduced by introducing feedforward control. The temperature of the band 10 can be controlled. Further, the temperature control of the steel strip 10 may be combined with the feedforward control and the feedback control to realize more accurate temperature control.

Next, an example showing the effect of the invention will be described. In this embodiment, the arrangement of each component constituting the steel strip temperature measuring device 1 such as the first radiation thermometer 41, the second radiation thermometer 42, and the upper transfer roll 30 is the same as in FIG. Further, in this embodiment, as the first radiation thermometer 41 and the second radiation thermometer 42, those equipped with an InGaAs element were used. In this embodiment, immediately after the measurement position PB of the second radiation thermometer 42, there is a water quenching step in which the steel strip 10 is water _- quenched by the quenching device 60, and the temperature of the steel strip 10 immediately before quenching is performed. Management is extremely important.

In this embodiment, first, the first radiation thermometer 41 was calibrated in advance. Next, the emissivity ε of the steel strip 10 was calculated from the measurement results of the first radiation thermometer 41 and the upper transport roll 30. The conversion formula used when calculating the emissivity ε was Sakuma Hattori's formula. Further, in this embodiment, the measurement position _PA of the first radiation thermometer 41 and the measurement position P _B of the second radiation thermometer 42 are separated by 30 [m] in the transport direction of the steel strip 10. Therefore, in this embodiment, the transport speed v [m / s] of the steel strip 10 is acquired from the rotation speed of the upper transport roll 30, and the first radiation thermometer 41 measures it before 30 / v [s]. The radiation rate ε calculated using the radiation temperature _TA or radiance _SA ( _TA ) and the temperature measurement value _Tr measured by the thermoelectric pair 31 of the upper transport roll 30 is calculated by the second radiation thermometer 42. It was applied when calculating the radiation temperature _TB . FIG. 5 shows the temperature measurement results of the steel strip 10 of this embodiment.

Here, when the emissivity ε was kept constant, the temperature measurement results of the steel strip 10 by the second radiation thermometer 42 varied greatly. On the other hand, in this embodiment, the emissivity ε is calculated every moment, the fluctuation of the emissivity ε is constantly corrected, and the temperature of the steel strip 10 is measured by the second radiation thermometer 42. As shown in 5, it can be seen that the variation in the temperature measurement result of the steel strip 10 is reduced. As described above, in this embodiment, the temperature of the steel strip 10 can be easily and accurately measured by the second radiation thermometer 42 using the correct emissivity ε in the straight path 50 immediately before the quenching device 60. ..

Further, the present invention may be applied as a temperature measuring device constituting a metal band manufacturing facility, and the temperature of the metal band manufactured by a known or existing manufacturing facility may be measured by the temperature measuring device according to the present invention. good. In this case, as described above, the manufacturing equipment for manufacturing the metal strip includes a transporting equipment having a roll for transporting the metal strip. Then, the temperature measuring device according to the present invention will be provided in this transport facility. Further, it is most desirable that the temperature measuring device according to the present invention is provided between two rolls for transporting a metal band in this transport facility.

Further, the present invention may be applied as a temperature measuring step included in the method for manufacturing a metal band, and the temperature of the metal band may be measured in a known or existing manufacturing step. In this case, as described above, it is desirable to provide a temperature measurement step for measuring the temperature of the metal band during production by using the temperature measurement method according to the present invention in the middle of the known or existing production step.

Specifically, it is desirable to provide a temperature measurement step before and after the temperature in the metal band manufacturing process changes abruptly. Rapid cooling by water cooling or air cooling, and rapid heating by an induction heating furnace (IH heating furnace for short for Induction Heating) or a direct heating furnace are very important as means for producing the desired material in the metal band manufacturing process. There is, accurate temperature measurement before and after the temperature change greatly contributes to the product material. However, immediately before or after such a quenching facility, or immediately before or after a rapid heating facility, it is often between rolls, and it is possible to apply an accurate temperature measurement method using a multiple reflection type or a temperature measurement roll. Have difficulty. By measuring the temperature according to the present invention, it becomes possible to accurately measure the temperature before and after quenching / heating, and to manufacture the metal band of the target material with accuracy.

When feed-forward control is used to increase the responsiveness of the temperature control, reduce the transient response period, and reduce the temperature unsteady region as much as possible, the temperature measurement step is added to the method for manufacturing the metal band. Shall measure the temperature during transportation of the metal band, and using the temperature measured in the temperature measuring step, one or a plurality of steps included in the manufacturing step after the temperature measuring step. Control process conditions.

Some specific examples of feedforward control will be described by taking a steel strip manufacturing technique as an example. In the heating zone where heating is controlled from the inlet temperature of the steel strip to the target temperature using a radiant heater, the temperature after heating changes due to changes in the entry side temperature and the emissivity of the steel strip due to some change in operating conditions from the steady state. Consider changing from the target temperature. At this time, since the emissivity is equal to the absorptivity, the amount of heat absorbed from the radiant heater depends on the emissivity. In the case of feedback control using the measured temperature value after heating, the output of the radiant heater does not change until it reaches after heating, and the control starts only after reaching after heating, so the steel strip transported during that time starts from the target temperature. The error becomes large. Using the emissivity calculated by the present invention, the amount of heat absorbed from the radiant heater is simulated at the time of entry, the temperature after heating is predicted, and the output of the radiant heater is feed-forward controlled in advance to control the heat after heating. The steel strip temperature can be brought closer to the target temperature, and as a result, the area of defective material can be reduced.

Next, in the heating zone where the temperature is controlled from the inlet temperature of the steel strip to the target temperature using an IH heating furnace or the like, the inlet temperature and the emissivity of the steel strip change due to some change in operating conditions from the steady state. Consider that the temperature after heating changes from the target temperature. At this time, radiant heat is removed from the steel strip, but the amount of heat removed depends on the emissivity. In the case of feedback control using the measured temperature value after heating, the output of the IH heating furnace etc. does not change until it reaches after heating, and the control starts only after reaching after heating, so the steel strip transported during that time is the target. The error from the temperature becomes large. Using the emissivity calculated by the present invention, the amount of heat radiated from the steel strip is simulated at the time of entry, the temperature after heating is predicted, and the output of the IH heating furnace is ford-forward controlled in advance for heating. The later steel strip temperature can be brought closer to the target temperature, and as a result, the area of the defective material can be reduced. In this specific example, the fluctuation of the amount of heat withdrawn due to the fluctuation of the emissivity during heating by IH is predicted, but the heat withdrawn during air cooling or heat retention can also be feed-forward controlled in the same manner.

According to such a metal strip manufacturing facility and a metal strip manufacturing method, the metal strip can be manufactured with a high yield. In particular, when the metal strip is a steel strip, that is, in the case of a steel strip manufacturing facility and a steel strip manufacturing method, the advantages of feedforward control can be maximized, which is particularly preferable.

Further, the present invention may be applied to the quality control method of the metal band, and the quality control of the metal band may be performed by measuring the temperature of the metal band. That is, the temperature history of the metal band in the manufacturing process greatly affects the surface texture and material of the final product. Therefore, it is very important for quality control to control the temperature to a predetermined temperature in each manufacturing process. Specifically, in the present invention, the temperature of the metal band can be measured in the temperature measurement step, and the quality control of the metal band can be performed from the measurement result obtained in the temperature measurement step. In the subsequent quality control step, based on the measurement results obtained in the temperature measurement step, it is determined whether or not the manufactured metal band meets the temperature control standard specified in advance by the temperature measured in each step. Control the quality of the metal strip. According to such a quality control method for metal strips, it is possible to provide high quality metal strips. In particular, it is particularly preferable when the metal strip is a steel strip, that is, when the quality control method for the steel strip is used.

1 Steel strip temperature measuring device 10,110 Steel strip 20 Lower transport roll 30 Upper transport roll (upstream roll)
31,131 Thermocouple 41 1st radiation thermometer 42 2nd radiation thermometer 50 Straight path 60,160 Quenching device 70,170 Control device 80 Conveying roll (downstream side roll)
120,130 Roll 140,142 Radiation thermometer

Claims (8)

A method for measuring the temperature of a metal band, which measures the temperature of the metal band between two rolls around which the metal band is wound, which are arranged at intervals in the transport direction of the metal band.
Of the two rolls, a step of measuring the temperature of the upstream roll by a thermocouple embedded in the upstream roll located on the upstream side in the transport direction of the metal band, and a step of measuring the temperature of the upstream roll.
A step of measuring the portion of the metal band wrapped around the upstream roll with a first radiation thermometer to obtain radiance, and a step of determining the radiance.
A step of calculating the emissivity of the metal band from the temperature measured by the thermocouple and the radiance, and the step of calculating the emissivity.
A step of measuring the surface temperature of the metal band at a measurement position set between the two rolls by a second radiation thermometer using the emissivity.
A method for measuring the temperature of a metal band, which comprises. The distance between the measurement position of the metal band surface by the first radiation thermometer and the measurement position of the metal band surface by the second radiation thermometer in the transport direction of the metal band.
The transport speed of the metal strip or the rotation speed of the upstream roll,
Using,
The method for measuring the temperature of a metal band according to claim 1, wherein the same location on the surface of the metal band is measured by the first radiation thermometer and the second radiation thermometer. A metal band temperature measuring device for measuring the surface temperature of the metal band between two rolls around which the metal band is wound, which are arranged at intervals in the transport direction of the metal band.
Of the two rolls, a thermocouple embedded in the upstream roll located on the upstream side in the transport direction of the metal band and measuring the temperature of the upstream roll.
A first radiation thermometer that measures the portion of the metal band wrapped around the upstream roll,
A means for calculating the emissivity of the metal band from the temperature measured by the thermocouple and the radiance obtained from the measurement result of the first radiation thermometer.
A second radiation thermometer that measures the surface temperature of the metal band at a measurement position set between the two rolls using the emissivity.
A metal band temperature measuring device characterized by being provided with. The distance between the measurement position of the metal band surface by the first radiation thermometer and the measurement position of the metal band surface by the second radiation thermometer in the transport direction of the metal band.
The transport speed of the metal strip or the rotation speed of the upstream roll,
Using,
The temperature measuring device for a metal band according to claim 3, wherein the same location on the surface of the metal band is measured by the first radiation thermometer and the second radiation thermometer. Metal strip manufacturing steps and
According to the method for measuring the temperature of the metal band according to claim 1 or 2, in the manufacturing step, the temperature measuring step for measuring the temperature of the metal band and the temperature measuring step.
A method for manufacturing a metal strip, which comprises. The temperature measurement step measures the temperature during transportation of the metal band.
The fifth aspect of claim 5, wherein the temperature measured in the temperature measuring step is used to control the conditions of one or a plurality of steps after the temperature measuring step among the steps included in the manufacturing step. How to make a metal strip. Manufacturing equipment for manufacturing metal strips and
The metal band temperature measuring device according to claim 3 or 4, which measures the temperature of the metal band manufactured by the manufacturing equipment.
Equipped with
The manufacturing equipment includes a transport equipment having a roll for transporting the metal strip.
The temperature measuring device is a metal band manufacturing facility provided in the transport facility. A temperature measurement step for measuring the temperature of the metal band by the method for measuring the temperature of the metal band according to claim 1 or 2.
From the temperature measurement result obtained by the temperature measurement step, a quality control step for performing quality control of the metal band and a quality control step.
A quality control method for metal strips, characterized by including.

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