JPH08193887A - Method for measuring temperature of material in hot rolling line - Google Patents

Abstract

PURPOSE: To accurately measure a temperature of a portion in the vicinity of an end section by a method wherein a material thermometer is scanned to measure a distribution of the temperatures of a material in the width direction, and a temperature on an arbitrary position in the width direction is calculated from the distribution, a visual field of the thermometer and a measuring pitch of the temperature. CONSTITUTION: Radiation thermometers 11, 12, 13 are respectively scanned on a left side end section A, a right side end section B and a central section of a rolled material S by a prescribed pitch to measure the temperature distribution thereof. An end section temperature calculation device 14 fetches measuring signals of the thermometer 11, 12 to calculate temperatures of arbitrary sections in the width direction on the basis of preset visual fields and measuring pitches of temperatures of the thermometers 11, 12 so that temperatures of the end sections in the width direction is presumed. It also fetches a measuring signal of the thermometer 13 on the central section of the rolled material S to obtain a temperature of a normal region. The calculation results are indicated on a temperature indication device 15. Thus, it is possible to measure temperatures of the end sections of the rolling material S with high accuracy.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a method for measuring the temperature of a material in a hot rolling line.

[0002]

2. Description of the Related Art Normally, in a hot rolling line, the temperature of the material in the width direction is measured in order to control the uniformity of the material temperature in the width direction of the sheet. That is, in the hot rolling line shown in FIG. 3, the rolled material S, which is discharged from the heating furnace 1 at a predetermined temperature, is roughly rolled by the rough rolling mill 2 and then finish rolled by the finish rolling mill 3 to wind up as a strip. At that time, the material thermometers 5, 6 and 7 installed on the outlet side of the rough rolling mill 2 and on the inlet side and the outlet side of the finish rolling mill 3 finish the rough rolling and finish rolling. The temperature distribution in the strip width direction of the rolled material S on the inlet side and the outlet side of is measured and managed. As these material thermometers 5 to 7, for example, radiation thermometers are used, and the temperature distribution is measured by scanning the rolled material S in the plate width direction.

[0003]

However, in the conventional material thermometer as described above, only by scanning the radiation thermometer in the width direction, the width direction end portion (hereinafter,
In some cases, the temperature in the vicinity (just called the edge) could not be measured accurately. Since there is a limit to how close the distance between the rolling material to be measured and the material thermometer can be, the field of view of the thermometer widens.Therefore, when measuring near the edge, there is an object outside the range of measurement in the field of view of the thermometer. It may enter and become noise. When the measurement target moves in the width direction, such as meandering of the seat bar, an error may occur in the temperature transition in the longitudinal direction at a fixed distance from the end.

Further, the temperature distribution of the cross section of the rolled material S is shown in FIG. 4. At the corner portion c of the end portion A and the like, defective quality occurs due to local temperature drop due to heat removal from the upper and lower surfaces and the end surface. In order to prevent this, it is necessary to control the temperature of the corner portion c, so it is necessary to accurately measure the temperature in the vicinity of the end portion. An object of the present invention is to provide a method for measuring the temperature in the plate width direction, which solves the above-mentioned problems, and in particular, a method for accurately measuring the temperature in the vicinity of the edge of a material.

[0005]

According to the present invention, in a method for measuring a material temperature in a hot rolling line, a material temperature distribution in a sheet width direction is measured while scanning a material thermometer having a predetermined visual field at a predetermined pitch. Using the first step, the material temperature distribution obtained in the first step, the field of view of the material thermometer and the value of the temperature measurement pitch, which are given in advance, at an arbitrary position in the plate width direction. A second step of calculating the temperature, and a third step of estimating the temperature near the edge of the material from the temperature distribution of the material at the arbitrary position in the plate width direction calculated in the second step.
The method of measuring the temperature of a material in a hot rolling line, comprising:

In the first step, the material end position is recognized by the sensor for recognizing the material end position, and this information is used to determine the material end temperature in the third step. Good.

[0007]

The output value obtained by scanning the radiation thermometer having the predetermined visual field at the predetermined pitch p is the average temperature in the visual field of the radiation thermometer. Therefore, if the field of view of the radiation thermometer is divided into an arbitrary number n, the temperature at the i-th position m _i thus divided is ε _i , and the contribution rate within the field of view is α _i , the temperature E in the field of view is Is represented as follows.

E = ε _i α _i ... (1) Here, α ₁ + α ₂ + ... + α _i ... + α _n = 1. Now, as shown in FIG. 5, the j-th measurement positions m ₁ , m ₂ ,
The temperature at each of m _i ..., α _n is ε ₁ , ε ₂ ,
... ε _i ..., ε _n , the temperature E _j in this field of view is
It is expressed by the equation (1) as the following equation (2).

E _j = ε ₁ α ₁ + ε ₂ α ₂ + ... + ε _i α _i … + ε _n α _n ………… (2) Further, the pitch is separated from the j-th measurement position by the pitch p (j +
1) The temperature E _{j + 1} in the visual field at the measurement position for the _{first time} is expressed as follows. E _{j + 1} = ε ₂ α ₁ + ... + ε _{i + 1} α _i … ＋ ε _{n + 1} α _n ……… (3) Even if the formula is created by repeating this, the field of view is divided arbitrarily. The temperature ε _i at the i-th position at that time cannot be calculated (here, α _i is an existing value).

However, as for the temperature distribution in the width direction, the measured value as shown by the characteristic curve T in FIG. 6 is output, and when the end portion A is separated by a certain length L ₁ , the radiation thermometer outputs the ambient temperature T. _It shows an almost constant value of _A. That is, FIG. 7 (a)
, (B), m ₁ ~ including the end A of the rolled material S
To describe a case of performing measurements on six points m _6, first, in the first of each position m ₁ divided when divided into four at an equal pitch p of the field of view of measurement, m _2, m _3, m ₄ Assuming that the temperatures are a ₁ , a ₂ , a ₃ , and a ₄ , since the first measurement shows the ambient temperature T _A , E ₁ = a ₁ = a ₂ = a ₃ = a ₄ ... (4) The temperatures a _{1 to} a _{4 at} each position can be grasped.

Next, at the second measurement position, which is a distance p away from the first measurement position, the temperature a at each of the divided positions m ₂ , m ₃ , m ₄ , m ₅ when the field of view is divided into four parts. ₂ , a
The temperature in the field of view can be represented by ₃ , a ₄ and a ₅ , and E ₂ = α ₁ a ₂ + α ₂ a ₃ + α ₃ a ₄ + α ₄ a ₅ (5) In this equation (5), E ₂ , α _{1 to} α ₄ , a ₂
For each value of ~a ₄ is known, it can be determined by calculating the a _5.

On the contrary, when entering the inside of the rolled material S (in the direction toward the center side) by the distance L _{2 in the above-mentioned} FIG. 6, a steady region which is very gentle as compared with the gradient of the temperature drop of the edge in the plate width direction is formed. The temperature becomes T _S. Also in this case, if it is assumed that the temperature at each position divided in the measurement visual field is equal to the measured temperature, as described above, other temperatures can be calculated using it as an initial value.

By repeating the scanning of the distance (L ₁ + L ₂ ) from the outer side to the inner side of the rolled material S, the temperatures a _{1 to} a _n at all positions m _{1 to mn} can be grasped. . At the same time, it is possible to know the absolute position of the end of the material by using a measurement signal from a strip width meter, etc. Can be reliably measured.

[0014]

Embodiments of the method of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a schematic view showing an embodiment of the rolled material end temperature measuring device of the present invention. In the figure, 11 is a radiation thermometer for measuring the temperature distribution of the left end A of the rolled material S while scanning it at a predetermined pitch.
Is a radiation thermometer which measures the temperature distribution while scanning the right end B of the rolled material S at a predetermined pitch. Also, 13
Is a radiation thermometer that measures the temperature distribution of the rolled material S while scanning the central portion of the material at a predetermined pitch.

Reference numeral 14 denotes an end temperature calculation device, which inputs the measurement signals of the radiation thermometers 11 and 12 at each end and uses the field of view of the radiation thermometer and the pitch of the temperature measurement which are given in advance, and The temperature at an arbitrary position in the strip width direction is calculated by the equations (4) and (5) to estimate the edge temperature. In addition,
The steady region temperature T _S of the rolled material _S is measured by inputting the measurement signal of the radiation thermometer 13 at the central portion of the rolled material S. A temperature display device 15 outputs and displays the calculation result of the end temperature calculation device 14.

The result of measuring the end temperature of the rolled material S by mounting the rolled material end temperature measuring device thus constructed on the entrance side of the finish rolling mill is shown by the solid line in FIG. For comparison, the temperature measurement result of the conventional method is shown by a broken line, and the measurement value (reference temperature) of the thermocouple is shown by a circle. As is clear from this figure, when the method of the present invention is applied, the value is closer to the measured value of the thermocouple than the conventional method, and the temperature at the end can be estimated more accurately. Recognize.

Although the radiation thermometer is used as the material thermometer in this embodiment, the present invention is not limited to this, and the thermometer capable of measuring the temperature distribution in the strip width direction of the rolled material. So long as it is of any type. Further, in this embodiment, three material thermometers are used, but one radiation thermometer may be used for scanning at high speed.

Further, by installing a sensor such as a width gauge capable of recognizing the position of the end of the material (for example, Japanese Patent Application Laid-Open No. 4-60405 or Japanese Patent Application Laid-Open No. 6-265326), it is possible to make a meandering rolled material. Following this, the end temperature can be measured more accurately.

[0019]

As described above, according to the present invention,
Since the edge temperature of the rolled material can be measured accurately,
By taking action early, it is possible to avoid a local temperature drop due to heat removal, which can contribute to the improvement of product quality.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing an embodiment of the present invention.

FIG. 2 is a characteristic diagram showing a measurement example of a temperature distribution at an end portion of a rolled material.

FIG. 3 is a schematic diagram showing a conventional hot rolling line.

FIG. 4 is an explanatory diagram of a temperature distribution at a rolled material end portion.

FIG. 5 is a schematic diagram showing a measurement range of a material thermometer.

FIG. 6 is a characteristic diagram showing a measurement example of temperature distribution in the plate width direction.

7A and 7B are schematic views showing the concept of the present invention.

[Explanation of symbols]

 1 Heating Furnace 2 Rough Rolling Machine 3 Finishing Rolling Machine 4 Winding Machine 5-7 Material Thermometer 11-13 Radiation Thermometer 14 Edge Temperature Calculation Device 15 Display Device S Rolled Material (Material)

Claims (2)

[Claims] 1. A method for measuring a temperature of a material in a hot rolling line, which comprises a first step of measuring a material temperature distribution in a sheet width direction while scanning a material thermometer having a predetermined visual field at a predetermined pitch. A second step of calculating the temperature at an arbitrary position in the plate width direction using the material temperature distribution obtained in the first step and the values of the field of view of the material thermometer and the temperature measurement pitch which are given in advance. And a third step of estimating the temperature in the vicinity of the edge of the material from the temperature distribution of the material in the plate width direction at an arbitrary position calculated in the second step. Method for measuring the temperature of materials. 2. In the first step, a material end position is recognized by a sensor that recognizes a material end position, and this information is used to determine the material end temperature in the third step. The method for measuring the temperature of a material in a hot rolling line according to claim 1, which is characterized in that.