JP2003294533A - Surface temperature measuring device and method of sheet steel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a surface temperature measuring device and a method of a sheet steel for measuring the surface temperature of the sheet steel in the state where a contact plate is contacted or slid on the surface of the sheet steel. <P>SOLUTION: A blackbody paint face is formed on the back of the contact plate, and noncontact measurement of a radiation temperature of the blackbody paint face is performed from the opposite direction to the blackbody paint face, to thereby perform contact measurement of the surface temperature of the sheet steel. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of a thin steel sheet surface temperature measuring device (also referred to as a temperature sensor) for measuring the surface temperature of a thin steel sheet which is at a high temperature and stops or moves at a low speed.

[0002]

2. Description of the Related Art Generally, when measuring the surface temperature of a thin steel sheet, if the emissivity of the thin steel sheet is unknown or fluctuates, accurate measurement is possible without being affected by the emissivity. A contact thermometer is used. The contact type thermometer is a method of measuring temperature by embedding a temperature measuring sensor such as a thermocouple in a contact plate such as a thin steel plate or pasting it on the back side and contacting the contact plate with the thin steel plate to be measured. It is a thermometer.

However, there are problems that there are restrictions on the measurement position and the measurement timing, and that it takes time to set up the measurement. As an improved temperature sensor, for example, Japanese Patent Laid-Open No. 7-198504 discloses a contact type surface temperature sensor shown in FIG. The contact-type temperature sensor 10 shown in FIG. 4 is a thermoelectric element in which a casing 12, an elastic contact plate 14 incorporated in the casing 12, and a heat-sensitive portion on the back surface of the contact portion 15 of the contact plate 14 with the measurement target are arranged. It is configured to have 19 ,. Then, the temperature is measured by bringing the contact portion 15 into contact with a measurement target (a thin steel plate) not shown. That is, the measurement method is based on the assumption that the contact plate 14 and the thin steel plate to be measured have the same temperature.

Further, in Japanese Patent No. 2741127,
A sliding temperature sensor for measuring the surface of a moving thin steel sheet is disclosed. FIG. 5 shows a schematic sectional view of the sliding temperature sensor 20. The sliding-type temperature sensor 20 is a member for sliding a sled member 28 to a measurement target (a thin steel plate) (not shown) to perform the measurement, and a pair of connecting rods 24 provided on the swing arm 34 is used for the measurement. A side plate 23 is arranged, and a heat sensitive plate 26 having a heat sensitive portion is arranged inside thereof. Reference numeral 33 is a code for the temperature measuring sensor. Like the contact type temperature sensor 10 shown in FIG. 4, this sliding type temperature sensor 20 also has a heat sensitive plate 26 corresponding to a contact plate.
The temperature is measured via the. In addition,
In Japanese Patent No. 2741127, it is said that the contact pressure is small and stable so as not to damage the thin steel sheet to be measured.

By the way, in the contact type or sliding type temperature sensor, the condition for accurately measuring the temperature is that the temperature of the thin steel plate to be measured is the same as that of the contact plate.
For this purpose, it is necessary to secure sufficient contact between the contact plate and the thin steel plate and the holding time thereof. The conditions required for the contact plate are as follows. The thickness should be as thin as possible In order to suppress heat removal from the thin steel sheet whose temperature is to be measured and to achieve a high response (response time) in measurement, it is necessary to reduce the heat capacity as much as possible. Excellent elasticity and strength at high temperature It is necessary to have sufficient elasticity to follow the surface of the thin steel sheet to be measured and to make stable contact. Further, even if a batch-like measuring method is adopted, the strength must be sufficient to ensure a certain life. Contact time should be 10 seconds or more. If the measurement with a thermocouple is assumed, the response time is about 3 seconds.
It takes about 10 seconds.

As a material of the contact plate satisfying such a condition, particularly in the case where the temperature exceeds 1000 ° C. as in a heating furnace, Inconel or the like which is a heat resistant alloy is used.

[0007]

The contact type temperature sensor including the above-mentioned conventional temperature sensor is premised on that the thin steel plate and the contact plate to be measured have the same temperature. . Therefore, the measurement requires a sufficient contact time with the thin steel sheet. In particular, considering the response speed of the thermocouple and the like, it is considered that the contact time with the thin steel sheet until the measurement becomes stable is about 10 seconds.

However, even if the contact plate is made of a heat-resistant alloy, its thickness is about 0.3 mm. Therefore, if the contact is repeated for the above contact time, the mechanical strength gradually decreases. , Finally, deformation will occur. Then, since the contact becomes insufficient, the measurement temperature is instructed to be low, and accurate temperature measurement cannot be performed. For this reason, if the measurement frequency is reduced in consideration of the life of the contact plate, the measurement may be omitted depending on the standard or plate thickness condition of the thin steel plate to be measured, which is a problem in quality assurance. Become. On the other hand, if it is attempted to maintain the measurement frequency, there is a problem that it is necessary to secure sufficient spare parts in preparation for deformation and the replacement frequency increases.

The present invention provides a surface temperature measuring apparatus and method for a thin steel sheet which solves the above-mentioned problems, shortens the contact time during measurement, and extends the life of the contact plate.

[0010]

The present invention solves the above problems by applying a radiation thermometer having a short response time in place of a temperature measuring element having a long response time such as a conventional thermocouple. . That is, the present invention is a surface temperature measuring device for a thin steel plate for measuring the surface temperature of the thin steel plate in a state where the contact plate is in contact with or slid on the surface of the thin steel plate, and is arranged on the back surface of the contact plate. A surface temperature measuring device for a thin steel sheet, comprising: a black body paint surface formed by: and a radiation thermometer that is located opposite to the black body paint surface and that measures a radiation temperature of the black body paint surface. The above problem was solved by.

It is preferable that the surface temperature measuring device for the thin steel plate has a blocking plate formed so as to surround the black body paint surface and the periphery of the radiation thermometer. Further, the present invention is a method for measuring the surface temperature of a thin steel sheet, wherein the contact plate is in contact with or slid on the surface of the thin steel sheet, and the surface temperature of the thin steel sheet is measured. A surface of a thin steel plate characterized by measuring the surface temperature of the thin steel plate by forming a paint surface and measuring the radiation temperature of the black body paint surface in a non-contact manner from the direction facing the black body paint surface. The above problems have been solved by the temperature measurement method.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION An example of a surface temperature measuring device for a thin steel sheet according to the present invention will be described in which a radiation thermometer is used as a temperature measuring portion of a touch roll type temperature sensor as shown in FIG.
Needless to say, the present invention is not limited to the configuration shown in FIG. As shown in FIG. 1, the surface temperature measuring device 6 for thin steel sheet of the present invention includes a holding member 5 via a touch roll 4 for stably following the thin steel sheet 1 conveyed at a low speed.
The contact plate 2 that is mounted on the holding member 5
Are configured to slide on the thin steel plate 1. Then, as shown in more detail in the cross-sectional view of FIG. 2, a black body paint is applied to the back surface side of the sled-shaped contact plate 2, that is, the surface side not contacting the thin steel plate 1 to form the black body paint surface 3. The radiation thermometer 8 is arranged at a position facing the black body paint surface 3 to measure the radiation temperature of the black body paint surface 3 in a non-contact manner.

The radiation thermometer 8 has a very short response time of about several tens of milliseconds, and even if the time until the temperature of the contact plate 2 stabilizes is taken into consideration, it is sufficient to take a contact time of about 3 seconds.
It is possible to measure in a short time. Further, since the radiation temperature of the blackbody paint surface 3 is measured, the emissivity can be accurately corrected and the influence of the emissivity fluctuation is reduced. here,
It is preferable to apply a black body paint having an emissivity of 0.9 or more to the black body paint surface 3. However, if the emissivity of the blackbody paint to be applied is known, the emissivity is not particularly limited.

An optical fiber type thermometer may be used as the radiation thermometer 8. In this case, the cable 9 is connected as an optical fiber cable to a light receiving unit (not shown). By using the radiation thermometer 8 of the optical fiber type, the sensor section can be downsized and the measurement field of view can be reduced. For example, if the sensor portion has a head diameter of 5 mmφ, a measurement field of view of the blackbody paint surface 3 of about 10 mmφ is sufficient, and the area for applying the blackbody paint can be reduced.

Further, it is preferable to form a blocking plate 7 so as to surround the black body paint surface 3 and the radiation thermometer 8 and surround the measurement visual field. This makes it possible to prevent background light noise from the outside of the furnace wall or the like, and suppress the radiation energy from the furnace wall or the like from being reflected by the contact plate and entering the thermometer. The blocking effect can improve the measurement accuracy and further reduce the contact time for measurement. In addition, since the shielding plate is provided close to the contact plate,
When the measurement time is long, the temperature of the shielding plate itself becomes high and back light noise occurs, but in the present invention, the temperature of the shielding plate does not become so high because the measurement can be performed in a short time,
There is no particular problem.

Here, the gap between the shield plate 7 and the contact plate 2 is preferably about 1 mm. Further, it is preferable that the outer diameter of the shielding plate 7 is about 20 mmφ with respect to the sensor unit having a head diameter of 5 mmφ. By the way, a bowl type radiation thermometer (not shown) may be used as the radiation thermometer. In this bowl-type radiation thermometer, a sensor unit is provided at the center of a hemispherical mirror whose inner surface is plated with gold, and the hemispherical mirror is brought close to a measurement target to measure the radiation temperature. By doing so, the effect of increasing the apparent emissivity due to the multiple reflections between the hemispherical mirror and the measurement target is utilized. For example, like the present invention,
When the emissivity of the blackbody paint surface 3 to be measured is 0.9 or more, the apparent emissivity becomes almost 1, and emissivity correction is unnecessary. In addition, since the hemispherical mirror is brought close to the contact plate, it can also serve as a shield plate, and it is possible to suppress back light noise (Measurement and Automatic Control Society, "New Temperature Measurement", 1992).
First issue on October 25, see p232).

[0017]

[Example] A surface temperature measuring device for thin steel sheet of the present invention (example of the present invention) to which a radiation thermometer was applied was applied to a line having a line speed of 15 mpm and a thin steel plate temperature of 900 ° C until the measurement became stable. The contact time required for the measurement was measured. In addition, in addition, the contact time required until the measurement by the conventional surface temperature measuring device for thin steel plates (conventional example) to which a thermocouple was applied was stabilized was measured. The result is shown in FIG.

As is apparent from FIG. 3, in the conventional example, about
A contact time of 10 seconds was required, but in the present invention example, about 3
Stable measurement is possible in seconds. That is, the measurement time can be reduced to about 1/3 of that of the conventional example, and the life of the contact plate can be extended. As a result, it has become possible to increase the number of measurements three times or more, and it is possible to deal with the measurement in various cases such as standards and heating patterns.

Further, by keeping the measurement frequency at the same level as in the conventional case, the contact plate can be replaced less frequently, and the number of replacement parts to be prepared can be reduced.

[0020]

According to the present invention, the contact time at the time of measurement can be shortened, the life of the contact plate can be extended, and the reliability of the surface temperature measuring device for thin steel sheets can be greatly improved. It was

[Brief description of drawings]

FIG. 1 is a schematic view of a surface temperature measuring device for a thin steel sheet according to the present invention.

FIG. 2 is a schematic cross-sectional view for explaining a main part of FIG.

FIG. 3 is a graph comparing the rising at the start of temperature measurement in the conventional example and the example of the present invention.

FIG. 4 is a schematic sectional view of a conventional contact temperature sensor.

FIG. 5 is a schematic sectional view of a conventional sliding temperature sensor.

[Explanation of symbols]

1 thin steel plate 2 contact plate 3 Blackbody paint surface 4 touch roll 5 holding member 6 Surface temperature measuring device for thin steel plates (temperature sensor) 7 Block 8 Radiation thermometer 9 cables (optical fiber cable) 10 Contact temperature sensor 12 casing 14 Contact plate 15 Contact part 19 Thermoelectric element (thermocouple) 20 Sliding temperature sensor 23 Side plate 24 connecting rod 26 heat sensitive plate 28 sled members 33 Sensor code 34 Swing arm

Claims (3)

[Claims] 1. A surface temperature measuring device for measuring a surface temperature of a thin steel plate in a state where the contact plate is in contact with or sliding on the surface of the thin steel plate, the device being arranged on the back surface of the contact plate. A surface temperature measuring device for a thin steel sheet, comprising: a black body paint surface; and a radiation thermometer that is positioned opposite to the black body paint surface and that measures the radiation temperature of the black body paint surface. 2. The surface temperature measuring device for a thin steel sheet according to claim 1, further comprising a shield plate surrounding the black body paint surface and the periphery of the radiation thermometer. 3. A method for measuring the surface temperature of a thin steel sheet, wherein the surface temperature of the thin steel sheet is measured while the contact plate is in contact with or slid on the surface of the thin steel sheet. Surface, the surface temperature of the thin steel sheet is characterized by measuring the surface temperature of the thin steel sheet by non-contact measurement of the radiation temperature of the black body coating surface from a direction facing the black body coating surface. Measuring method.