JP3975584B2

JP3975584B2 - Surface temperature measurement method

Info

Publication number: JP3975584B2
Application number: JP29723498A
Authority: JP
Inventors: 千尋植松; 達朗本田
Original assignee: Sumitomo Metal Industries Ltd
Current assignee: Sumitomo Metal Industries Ltd
Priority date: 1998-10-19
Filing date: 1998-10-19
Publication date: 2007-09-12
Anticipated expiration: 2018-10-19
Also published as: JP2000121445A

Description

【０００１】
【発明の属する技術分野】
本発明は、低温領域にある測定対象物（例えば冷間圧延中の測定対象物）の表面温度を測定する非接触式表面温度測定方法に関する。
【０００２】
【従来の技術】
ライン上を移動する測定対象物の表面温度を測定する方法として測定対象物の表面からの放射赤外線を利用した非接触式温度測定方法が知られている。
【０００３】
特開平５−２４８９５７号公報に記載されている非接触式温度測定方法で使用する表面温度測定装置は、放射温度計の赤外線センサが測定対象物を覗き見る位置に覗筒を設け、覗筒の先端部には中央部に覗き開孔を有する水冷遮蔽板が設けてある。また、水冷遮蔽板の表面温度を測定するための熱電温度計の熱電対が水冷遮蔽板の測定対象物対向面に、更に、周囲の温度（この場合測定位置周辺部の空気）を測定するため熱電温度計の熱電対が、迷光雑音（表面温度を測定する領域から放射されるのではなくこの領域外にある物体から放射される赤外線がこの領域で反射されて検出される赤外線）が最も入射しやすい位置に設けてある。
【０００４】
赤外線センサは、測定対象物から放射される赤外線を水冷遮蔽板の開孔部を通して検出することによって測定対象物の表面温度を測定する。また、測定対象物の表面温度が測定されている間に上述した熱電温度計は、水冷遮蔽板の表面温度及び周囲の温度を測定する。
【０００５】
放射温度計及び２つの熱電温度計によって検出される温度の検出値は、演算装置へ出力される。ここでは、水冷遮蔽板の測定対象物対向面から測定対象物までの距離の関数により定まる水冷遮蔽板からの迷光雑音影響関数及び周囲物体からの迷光雑音影響関数と、上述した温度の検出値とに基づいて、放射温度計が検出した放射赤外線光量のうち水冷遮蔽板及び周囲物体からの迷光雑音の影響分を演算し、この放射赤外線光量から迷光雑音の影響分を除去することにより測定対象物の表面温度の測定精度を向上させている。
【０００６】
【発明が解決しようとする課題】
低温領域にある測定対象物（例えば冷間圧延中の測定対象物）の表面から放射される赤外線光量を検出して表面温度を測定する場合、測定対象物からの放射赤外線光量は少ないために上述した非接触式温度測定方法では水冷遮蔽板及び周囲物体からの迷光雑音の影響が顕著になる。この迷光雑音の影響を考慮に入れ、測定対象物の表面温度の測定精度を向上させるためには、覗き開孔中心から水冷遮蔽板の測定対象物対向面の外周までの距離を、水冷遮蔽板の測定対象物対向面から測定対象物までの距離に対して大きくすればよいことが知られている。しかしながら、この様な水冷遮蔽板を有する大型の放射温度計を備えた表面温度測定装置は高価であり、また、設置スペースが限られている場合には設置が困難である。
【０００７】
本発明は斯かる事情に鑑みてなされたものであり、測定対象物の表面温度測定領域及びこの領域の近傍にある流体を接触させた参照領域からの放射赤外線光量に基づいて放射赤外線光量のうちの迷光雑音による影響分を演算により除去した結果と、表面温度測定領域の熱容量、単位時間あたりに参照領域に接触する流体の流量及び熱容量とに基づいて表面温度を算出することにより、低温領域にある測定対象物の表面温度を測定するための表面温度測定装置を小型化することが可能な表面温度測定方法を提供することを目的とする。
【０００９】
更に、演算結果に基づいて表面温度を算出する際に測定対象物の移動速度を考慮した演算を行うことにより、上述した表面温度測定方法をより高精度に実施することが可能な表面温度測定方法を提供することを他の目的とする。
【００１０】
【課題を解決するための手段】
請求項１に係る表面温度測定方法は、測定対象物の表面温度を測定する第１領域の近傍に所定の温度に制御した流体を接触させて該流体を接触させた第２領域の表面温度を変化させ、第１領域からの放射赤外線光量及び第２領域からの放射赤外線光量をそれぞれ検出し、両領域からの放射赤外線光量のうちの迷光雑音による影響分を、第１領域からの放射赤外線光量から第２領域からの放射赤外線光量を減じることにより除去する演算をして第１領域の表面温度を求める演算式を得、該演算式に基づいて第１領域の表面温度を算出する表面温度測定方法において、第１領域の熱容量、第２領域に単位時間あたりに接触する前記流体の流量及び熱容量、並びに前記流体の温度の関数により求まる第１領域と第２領域との表面温度差を前記演算式に与えて第１領域の表面温度を算出することを特徴とする。
【００１２】
請求項２に係る表面温度測定方法は、移動する測定対象物の表面温度を測定する第１領域の近傍に所定の温度に制御した流体を接触させて該流体を接触させた第２領域の表面温度を変化させ、第１領域からの放射赤外線光量及び第２領域からの放射赤外線光量をそれぞれ検出し、両領域からの放射赤外線光量のうちの迷光雑音による影響分を、第１領域からの放射赤外線光量から第２領域からの放射赤外線光量を減じることにより除去する演算をして第１領域の表面温度を求める演算式を得、該演算式に基づいて第１領域の表面温度を算出する表面温度測定方法において、前記測定対象物の移動速度を検出し、該移動速度、第１領域の熱容量、第２領域に単位時間あたりに接触する前記流体の流量及び熱容量、並びに前記流体の温度の関数により求まる第１領域と第２領域との表面温度差を前記演算式に与えて第１領域の表面温度を算出することを特徴とする。
【００１３】
測定対象物の表面温度を測定する第１領域の表面温度がＴｓ（未知）である測定対象物の、この領域からの放射赤外線光量及びこの領域外からの迷光雑音による放射赤外線光量との和Ｌは下記（１）式で与えられる。
【００１４】
Ｌ＝εｓ・Ｌｂ（Ｔｓ）＋α（１−εｓ）・εｗ・Ｌｂ（Ｔｗ） …（１）
ここで、Ｌｂ（Ｔｓ）は温度Ｔｓの物体の黒体放射輝度、
εｓは測定対象物の放射率、
αは迷光雑音影響係数、
εｗは周辺物体の放射率（平均値）、
Ｔｗは周辺の環境温度をそれぞれ表す。
【００１５】
（１）式において、右辺第１項は第１領域からの放射赤外線光量を、また、右辺第２項はこの領域以外からの迷光雑音による放射赤外線光量をそれぞれ表す。第１領域の近傍にある第２領域（表面温度の参照領域）に所定の温度に制御した流体を接触させたとき、この領域の表面温度はΔｔだけ変化し、このとき、第２領域からの放射赤外線光量及びこの領域以外からの迷光雑音による放射赤外線光量の和Ｌｔは下記（２）式で表される。
【００１６】
Ｌｔ＝εｓ・Ｌｂ（Ｔｓ＋Δｔ）＋α（１−εｓ）・εｗ・Ｌｂ（Ｔｗ）…（２）
【００１７】
（１）式における、第１領域以外からの迷光雑音による放射赤外線光量及び（２）式における、第２領域以外からの迷光雑音による放射赤外線光量は等しいため、（１）式から、（２）式を減じることにより、迷光雑音による放射赤外線光量を消去することが可能であり、下記（３）式を得る。
【００１８】

ここで、ΔＬは、第１領域と第２領域との放射赤外線光量差である。
【００１９】
第１領域と第２領域との間の表面温度差Δｔは、第１領域の温度と熱容量、単位時間に第２領域に接触する上述した流体の流量と熱容量、及びこの流体の温度により定まり、これらを用いて表面温度を算出することによって回帰的に求められた関数Ｆにより下記（４）式に示す如く定まる。
【００２０】
Δｔ＝Ｆ（Ｔｓ，Ｃｓ，ｌ，Ｃａ，Ｔａ，） …（４）
ここで、Ｃｓは第１領域の熱容量、
ｌは単位時間に第２領域に接触する上述した流体の流量、
Ｃａはその熱容量、
Ｔａはその温度をそれぞれ表す。
【００２１】
（３）式及び（４）式より、ΔＬは下記（５）式に示す如く表せる。
【００２２】

【００２３】
上述の流体の温度をＴａに制御し、上述した放射赤外線光量差ΔＬを検出してこれらを（５）式に与え、（５）式より第１領域の表面温度Ｔｓを算出する演算を行うことにより測定対象物の表面温度が算出される。
以上が第１発明に係る表面温度測定方法である。
【００２９】
測定対象物表面からの放射赤外線光量を検出する際に、測定対象物表面から実際に放射される赤外線光量と検出される赤外線光量とには相違があり、この相違は、測定対象物が高速で移動する場合には大きくなることが知られている。この場合、検出される放射赤外線光量に基づいて測定対象物の表面温度を算出する際に測定対象物の移動速度を考慮しないと精度の高い測温精度が得られない。
【００３０】
そこで、第２発明に係る表面温度測定方法では、測定対象物が高速で移動する場合においても高い測温精度が得られるように、第１領域と第２領域との表面温度差Δｔを定める関数の要素に測定対象物の移動速度Ｖｓを加えた下記（８）式を用いる。
【００３１】
Δｔ＝Ｆ（Ｔｓ，Ｃｓ，ｌ，Ｃａ，Ｔａ，Ｖｓ） …・（８）
【００３２】
（８）式を（５）式の関数Ｆに代えて与えることによって下記（９）式を得る。
【００３３】

【００３４】
上述した流体の温度をＴａに制御し、上述した放射赤外線光量差ΔＬ及び測定対象物の移動速度Ｖｓを検出し、これらを（９）式に与えて第１領域の表面温度Ｔｓを算出する演算を行うことにより測定対象物の表面温度が算出される。
以上が第２発明に係る表面温度測定方法である。
【００３５】
【発明の実施の形態】
以下、本発明をその実施の形態を示す図面に基づいて詳述する。
【００３６】
実施の形態１．
図１は、本発明に係る表面温度測定方法を冷間圧延中の鋼板に対して実施する際に用いる装置を示した模式図である。
図において１は測定対象物である鋼板であり、鋼板１の上方には表面温度を測定する第１領域を視野とする赤外線センサ２と、第１領域の近傍にある第２領域（表面温度の参照領域）を視野とする赤外線センサ３とが設けられている。第２領域には、送風機４から送風され配管５を流れる空気が空気吹き付け口８から吹き付けられる。この空気の温度は、配管５を流れる間に空気加熱器６及び空気冷却器７により予め設定した温度（鋼板１の冷却程度により決定される）に制御され、第２領域に単位時間あたりに吹き付けられるこの空気の吹き付け量は、図示しない流量制御手段により予め設定した流量に制御される。空気吹き付け口８の近傍には、第２領域に吹き付けられる空気の温度を検出するための温度センサ９が設けてある。
【００３７】
温度センサ９が検出した空気温度は、表面温度演算器１０ａへフイードバックされ、空気加熱器６及び空気冷却器７により配管５を流れる空気温度が制御される。また、赤外線センサ２、３によって検出される放射赤外線光量及び温度センサ９により検出される空気温度は表面温度演算器１０ａへ逐次入力される。本実施の形態では、第２領域の表面温度を変化させるための流体として空気を用いるが、これは、例えば水のような液体であっても良い。
【００３８】
表面温度演算器１０ａには、鋼板１の黒体放射輝度Ｌｂ、放射率εｓ及び迷光雑音影響係数α、鋼板１の周辺にある物体の放射率εｗ（平均値）及び周辺の環境温度Ｔｗ（表面温度を測定する環境を考慮した温度）が予め与えてあり、下記に示す（１）式及び（２）式、

が設定されている。（２）式中のΔｔは、第１領域及び第２領域の表面温度差であり、これは、第１領域の表面温度Ｔｓ及び熱容量Ｃｓ、単位時間あたり第２領域に吹き付けられる空気の流量ｌ及び熱容量Ｃａ並びにこの空気温度Ｔａの（４）式に示す関数により定義されている。
Δｔ＝Ｆ（Ｔｓ，Ｃｓ，ｌ，Ｃａ，Ｔａ，） …（４）
【００３９】
表面温度演算器１０ａは、赤外線センサ２、３によって検出された放射赤外線光量を（１）式のＬ、（２）式のＬｔに与え、（１）式から（２）式を減算し、第１領域、第２領域からの放射赤外線光量のうちの迷光雑音の影響分が除去された第１領域の表面温度を算出するための（５）式を得る。

（５）式に温度センサ９により検出された空気温度Ｔａを与えて第１領域の表面温度を算出する。算出された第１領域の表面温度Ｔｓは温度表示部１１に出力されて表示される。
【００４５】
実施の形態２．
図２は本発明に係る表面温度測定方法を長手方向に移動する冷間圧延中の鋼板に対して実施する際に用いる装置を示した模式図である。
【００４６】
本実施の形態では、実施の形態１に用いる表面温度演算器１０ａに代えて表面温度演算器１０ｃを設ける。また、ロータリーエンコーダーを用いた速度検出器１３をロール１２に連結して設け、鋼板１を案内するロール１２の回転速度から鋼板１の移動速度を検出する。
【００４７】
表面温度演算器１０ｃでは、鋼板１の移動速度Ｖｓ、第１領域の表面温度Ｔｓ及び熱容量Ｃｓ、第２領域に単位時間あたりに接触する空気の流量ｌ及び熱容量Ｃａ、並びにこの空気の温度Ｔａにより（８）式の如く定まる関数により第１領域及び第２領域の表面温度差Δｔが定義されている。
Δｔ＝Ｆ（Ｔｓ，Ｃｓ，ｌ，Ｃａ，Ｔａ，Ｖｓ） …（８）
【００４８】
表面温度演算器１０ｃは、上述の如く迷光雑音を除去する演算をし、第１領域の表面温度を求めるための（９）式を得る。

（９）式より第１領域の表面温度を算出する際に速度検出器１３により検出された鋼板１の移動速度を与える。こうして算出された第１領域の表面温度は温度表示部１１に出力され表示される。尚、その他は発明の実施の形態１と同一であるので説明を省略する。
【００４９】
【発明の効果】
以上詳述した如く本発明に係る表面温度測定方法によれば、測定対象物の表面温度を測定する第１領域及びこの領域の近傍にある流体を接触させた第２領域からの放射赤外線光量に基づいて第１領域から検出された放射赤外線光量のうちの迷光雑音による影響分を演算により除去し、これと、第１領域の熱容量、単位時間あたり第２領域に吹き付けられる空気の流量及び熱容量並びにこの空気温度とに基づいて第１領域の表面温度を算出することが可能になる。従って、低温領域にある測定対象物の表面温度を算出するために測定対象物からの放射赤外線光量を検出するための装置に迷光雑音を除去するための水冷遮蔽板を設けなくてもよく、表面温度測定装置を小型化することが可能になる。
【００５１】
更に、第１領域の表面温度を算出する際に測定対象物の移動速度を考慮した演算を行うことにより、第１領域の表面温度をより高精度に算出することが可能になる等、本発明は優れた効果を奏する。
【図面の簡単な説明】
【図１】本発明に係る表面温度測定方法を冷間圧延中の鋼板に対して実施する際に用いる装置を示した模式図である。
【図２】本発明に係る表面温度測定方法を長手方向に移動する冷間圧延中の鋼板に対して実施する際に用いる装置を示した模式図である。
【符号の説明】
１鋼板
２、３赤外線センサ
４送風機
５配管
６空気加熱器
７空気冷却器
８空気吹き付け口
９温度センサ
１０ａ、１０ｂ、１０ｃ表面温度演算器
１１温度表示部
１２ロール
１３速度検出器[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a non-contact type surface temperature measurement method for measuring a surface temperature of a measurement object (for example, a measurement object during cold rolling) in a low temperature region.
[0002]
[Prior art]
As a method for measuring the surface temperature of a measurement object moving on a line, a non-contact temperature measurement method using radiant infrared rays from the surface of the measurement object is known.
[0003]
The surface temperature measuring device used in the non-contact temperature measuring method described in JP-A-5-248957 is provided with a viewing tube at a position where the infrared sensor of the radiation thermometer looks into the measurement object. A water-cooled shielding plate having a peep hole at the center is provided at the tip. In addition, the thermocouple of the thermoelectric thermometer for measuring the surface temperature of the water-cooled shield plate further measures the ambient temperature (in this case, the air around the measurement position) on the surface of the water-cooled shield plate facing the object to be measured. The thermocouple of the thermoelectric thermometer is the most incident with stray light noise (infrared light that is detected by reflection of infrared light emitted from an object outside this area rather than being emitted from the surface temperature measurement area) It is provided at a position where it is easy to do.
[0004]
The infrared sensor measures the surface temperature of the measurement object by detecting the infrared ray radiated from the measurement object through the opening of the water-cooled shielding plate. Further, the thermoelectric thermometer described above measures the surface temperature of the water-cooled shielding plate and the ambient temperature while the surface temperature of the measurement object is being measured.
[0005]
The detection value of the temperature detected by the radiation thermometer and the two thermoelectric thermometers is output to the arithmetic unit. Here, the stray light noise influence function from the water cooling shield plate and the stray light noise influence function from surrounding objects determined by the function of the distance from the measurement object facing surface of the water cooling shield plate to the measurement object, and the detected value of the temperature described above The object to be measured is calculated by calculating the influence of stray light noise from the water-cooled shielding plate and surrounding objects from the amount of radiation infrared light detected by the radiation thermometer, and removing the influence of stray light noise from this radiation infrared light quantity. The surface temperature measurement accuracy is improved.
[0006]
[Problems to be solved by the invention]
When the surface temperature is measured by detecting the amount of infrared light emitted from the surface of a measurement object (for example, the measurement object during cold rolling) in the low temperature region, the amount of infrared light emitted from the measurement object is small, so that In the non-contact type temperature measurement method, the influence of stray light noise from the water-cooled shielding plate and surrounding objects becomes significant. In order to improve the measurement accuracy of the surface temperature of the measurement object in consideration of the effect of this stray light noise, the distance from the center of the viewing hole to the outer periphery of the surface facing the measurement object of the water cooling shield It is known that the distance from the measurement object facing surface to the measurement object may be increased with respect to the distance. However, a surface temperature measuring device including a large radiation thermometer having such a water-cooled shielding plate is expensive, and is difficult to install when the installation space is limited.
[0007]
The present invention has been made in view of such circumstances, and based on the amount of radiant infrared light based on the surface temperature measurement region of the measurement object and the radiant infrared light amount from the reference region in contact with the fluid in the vicinity of this region. By calculating the surface temperature based on the result of removing the influence of the stray light noise by the calculation, the heat capacity of the surface temperature measurement area, the flow rate of the fluid that contacts the reference area per unit time, and the heat capacity, An object of the present invention is to provide a surface temperature measuring method capable of downsizing a surface temperature measuring device for measuring the surface temperature of a measurement object.
[0009]
Furthermore, the surface temperature measurement method capable of performing the above-described surface temperature measurement method with higher accuracy by performing the calculation in consideration of the moving speed of the measurement object when calculating the surface temperature based on the calculation result. For other purposes.
[0010]
[Means for Solving the Problems]
In the surface temperature measurement method according to claim 1, the surface temperature of the second region in which the fluid controlled to a predetermined temperature is brought into contact with the vicinity of the first region where the surface temperature of the measurement object is measured is brought into contact with the fluid. The amount of radiated infrared light from the first region and the amount of radiated infrared light from the second region are detected, and the influence of stray light noise in the amount of radiated infrared light from both regions is detected. The surface temperature measurement for calculating the surface temperature of the first region based on the arithmetic expression obtained by calculating the surface temperature of the first region by performing the operation of removing by reducing the amount of radiant infrared light from the second region from In the method, the calculation is performed on the surface temperature difference between the first region and the second region determined by a function of the heat capacity of the first region, the flow rate and heat capacity of the fluid contacting the second region per unit time, and the temperature of the fluid. formula And calculating the surface temperature of the first region is given.
[0012]
The surface temperature measuring method according to claim 2 is the surface of the second region in which the fluid controlled to a predetermined temperature is brought into contact with the vicinity of the first region for measuring the surface temperature of the moving measurement object, and the fluid is brought into contact with the fluid. The temperature is changed, the amount of radiated infrared light from the first region and the amount of radiated infrared light from the second region are detected, and the influence of stray light noise in the amount of radiated infrared light from both regions is radiated from the first region. A surface for calculating the surface temperature of the first region based on the equation obtained by calculating the surface temperature of the first region by performing an operation for removing the infrared light amount by subtracting the amount of infrared light emitted from the second region. In the temperature measurement method, the moving speed of the object to be measured is detected, a function of the moving speed, the heat capacity of the first region, the flow rate and heat capacity of the fluid contacting the second region per unit time, and the temperature of the fluid. In Ri surface temperature difference between the first region and the second region obtained and calculates the surface temperature of the first region is given to the arithmetic expression.
[0013]
The sum L of the amount of radiated infrared light from this region and the amount of radiated infrared light from outside this region of the measurement target whose surface temperature of the first region for measuring the surface temperature of the object to be measured is Ts (unknown). Is given by the following equation (1).
[0014]
L = εs · Lb (Ts) + α (1−εs) · εw · Lb (Tw) (1)
Where Lb (Ts) is the black body radiance of the object of temperature Ts,
εs is the emissivity of the measurement object,
α is a stray light noise influence coefficient,
εw is the emissivity (average value) of surrounding objects,
Tw represents the ambient environmental temperature.
[0015]
In the equation (1), the first term on the right side represents the amount of radiated infrared light from the first region, and the second term on the right side represents the amount of radiated infrared light due to stray light noise from other regions. When a fluid controlled to a predetermined temperature is brought into contact with a second region (surface temperature reference region) in the vicinity of the first region, the surface temperature of this region changes by Δt. The sum Lt of the radiant infrared light amount and the radiant infrared light amount due to the stray light noise from outside this region is expressed by the following equation (2).
[0016]
Lt = εs · Lb (Ts + Δt) + α (1−εs) · εw · Lb (Tw) (2)
[0017]
In equation (1), the amount of radiant infrared light due to stray light noise from other than the first region and the amount of radiant infrared light due to stray light noise from other than the second region in equation (2) are equal. From equation (1), (2) By subtracting the expression, it is possible to eliminate the amount of radiant infrared light due to stray light noise, and the following expression (3) is obtained.
[0018]

Here, ΔL is the difference in the amount of emitted infrared light between the first region and the second region.
[0019]
The surface temperature difference Δt between the first region and the second region is determined by the temperature and heat capacity of the first region, the flow rate and heat capacity of the fluid that contacts the second region per unit time, and the temperature of the fluid, The surface temperature is calculated using these, and is determined as shown in the following equation (4) by the function F obtained recursively.
[0020]
Δt = F (Ts, Cs, l, Ca, Ta,) (4)
Where Cs is the heat capacity of the first region,
l is the flow rate of the fluid mentioned above that contacts the second region per unit time,
Ca is its heat capacity,
Ta represents the temperature.
[0021]
From the equations (3) and (4), ΔL can be expressed as shown in the following equation (5).
[0022]

[0023]
Control the temperature of the above fluid to Ta, detect the above-mentioned difference in the amount of radiant infrared light ΔL, give these to the equation (5), and calculate the surface temperature Ts of the first region from the equation (5) Thus, the surface temperature of the measurement object is calculated.
The above is the surface temperature measuring method according to the first invention.
[0029]
When detecting the amount of infrared light emitted from the surface of the measurement object, there is a difference between the amount of infrared light actually emitted from the surface of the measurement object and the amount of infrared light detected. It is known that it becomes larger when moving. In this case, when calculating the surface temperature of the measurement object based on the detected amount of radiant infrared light, high temperature measurement accuracy cannot be obtained unless the moving speed of the measurement object is taken into consideration.
[0030]
Therefore, in the surface temperature measurement method according to the second invention, a function that determines the surface temperature difference Δt between the first region and the second region so that high temperature measurement accuracy can be obtained even when the measurement object moves at high speed. The following equation (8) is used in which the moving speed Vs of the measurement object is added to the element of:
[0031]
Δt = F (Ts, Cs, l, Ca, Ta, Vs) (8)
[0032]
The following equation (9) is obtained by giving the equation (8) instead of the function F of the equation (5).
[0033]

[0034]
The above-described fluid temperature is controlled to Ta, the above-mentioned radiation infrared light amount difference ΔL and the moving speed Vs of the measurement object are detected, and these are given to equation (9) to calculate the surface temperature Ts of the first region. To calculate the surface temperature of the measurement object.
The above is the surface temperature measurement method according to the second invention.
[0035]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in detail with reference to the drawings illustrating embodiments thereof.
[0036]
Embodiment 1 FIG.
FIG. 1 is a schematic view showing an apparatus used when the surface temperature measuring method according to the present invention is performed on a steel sheet during cold rolling.
In the figure, reference numeral 1 denotes a steel plate as a measurement object. Above the steel plate 1, an infrared sensor 2 having a first area for measuring the surface temperature as a field of view and a second area (surface temperature) in the vicinity of the first area. An infrared sensor 3 having a reference region) as a visual field is provided. Air blown from the blower 4 and flowing through the pipe 5 is blown from the air blowing port 8 to the second region. The temperature of the air is controlled to a preset temperature (determined by the degree of cooling of the steel plate 1) by the air heater 6 and the air cooler 7 while flowing through the pipe 5, and sprayed to the second region per unit time. The amount of air blown is controlled to a preset flow rate by a flow rate control means (not shown). In the vicinity of the air blowing port 8, a temperature sensor 9 for detecting the temperature of the air blown to the second region is provided.
[0037]
The air temperature detected by the temperature sensor 9 is fed back to the surface temperature calculator 10a, and the air temperature flowing through the pipe 5 is controlled by the air heater 6 and the air cooler 7. The amount of radiant infrared light detected by the infrared sensors 2 and 3 and the air temperature detected by the temperature sensor 9 are sequentially input to the surface temperature calculator 10a. In the present embodiment, air is used as the fluid for changing the surface temperature of the second region, but this may be a liquid such as water, for example.
[0038]
The surface temperature calculator 10a includes black body radiance Lb, emissivity εs and stray light noise influence coefficient α of the steel plate 1, emissivity εw (average value) of objects around the steel plate 1, and ambient environmental temperature Tw (surface (Temperature considering the environment for measuring temperature) is given in advance, and the following formulas (1) and (2):

Is set. In the equation (2), Δt is the surface temperature difference between the first region and the second region, which is the surface temperature Ts and heat capacity Cs of the first region, and the flow rate l of air blown to the second region per unit time. And the heat capacity Ca and the air temperature Ta are defined by the function shown in the equation (4).
Δt = F (Ts, Cs, l, Ca, Ta,) (4)
[0039]
The surface temperature calculator 10a gives the amount of radiated infrared rays detected by the infrared sensors 2 and 3 to L in the formula (1) and Lt in the formula (2), subtracts the formula (2) from the formula (1), Equation (5) for calculating the surface temperature of the first region from which the influence of stray light noise out of the amount of radiated infrared light from the first region and the second region is removed is obtained.

The surface temperature of the first region is calculated by giving the air temperature Ta detected by the temperature sensor 9 to the equation (5). The calculated surface temperature Ts of the first region is output to the temperature display unit 11 and displayed.
[0045]

Embodiment

2 FIG.
FIG. 2 is a schematic view showing an apparatus used when the surface temperature measuring method according to the present invention is applied to a steel sheet during cold rolling that moves in the longitudinal direction.
[0046]
In the present embodiment, a surface temperature calculator 10c is provided instead of the surface temperature calculator 10a used in the first embodiment. In addition, a speed detector 13 using a rotary encoder is connected to the roll 12 to detect the moving speed of the steel sheet 1 from the rotational speed of the roll 12 that guides the steel sheet 1.
[0047]
In the surface temperature calculator 10c, the moving speed Vs of the steel sheet 1, the surface temperature Ts and the heat capacity Cs of the first region, the flow rate l and the heat capacity Ca of the air contacting the second region per unit time, and the temperature Ta of the air The surface temperature difference Δt between the first region and the second region is defined by a function determined as in equation (8).
Δt = F (Ts, Cs, l, Ca, Ta, Vs) (8)
[0048]
The surface temperature calculator 10c performs an operation for removing the stray light noise as described above, and obtains equation (9) for determining the surface temperature of the first region.

The moving speed of the steel sheet 1 detected by the speed detector 13 when the surface temperature of the first region is calculated from the equation (9) is given. The surface temperature of the first region thus calculated is output and displayed on the temperature display unit 11. The rest of the configuration is the same as that of the first embodiment, and a description thereof will be omitted.
[0049]
【The invention's effect】
As described above in detail, according to the surface temperature measuring method according to the present invention, the amount of radiated infrared light from the first region for measuring the surface temperature of the object to be measured and the second region in contact with the fluid in the vicinity of this region is measured. Based on the amount of radiant infrared light detected from the first area, the influence of stray light noise is removed by calculation, and the heat capacity of the first area, the flow rate and heat capacity of the air blown to the second area per unit time, and Based on the air temperature, the surface temperature of the first region can be calculated. Therefore, it is not necessary to provide a water-cooled shielding plate for removing stray light noise in the device for detecting the amount of radiated infrared light from the measurement object in order to calculate the surface temperature of the measurement object in the low temperature region. The temperature measuring device can be reduced in size.
[0051]
Furthermore, when calculating the surface temperature of the first region, it is possible to calculate the surface temperature of the first region with higher accuracy by performing an operation in consideration of the moving speed of the measurement object. Has an excellent effect.
[Brief description of the drawings]
FIG. 1 is a schematic view showing an apparatus used when a surface temperature measuring method according to the present invention is applied to a steel sheet during cold rolling.
FIG. 2 is a schematic view showing an apparatus used when the surface temperature measuring method according to the present invention is performed on a steel sheet during cold rolling that moves in the longitudinal direction.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Steel plate 2, 3 Infrared sensor 4 Blower 5 Piping 6 Air heater 7 Air cooler 8 Air blowing port 9 Temperature sensor 10a, 10b, 10c Surface temperature calculator 11 Temperature display part 12 Roll 13 Speed detector

Claims

The fluid controlled to a predetermined temperature is brought into contact with the vicinity of the first region for measuring the surface temperature of the measurement object, the surface temperature of the second region in contact with the fluid is changed, and the amount of infrared radiation emitted from the first region is changed. The amount of radiated infrared light from the second region is detected, and the influence of stray light noise in the amount of radiated infrared light from both regions is subtracted from the amount of radiated infrared light from the first region. In the surface temperature measuring method for calculating the surface temperature of the first region based on the calculation formula, the heat capacity of the first region, the second A surface temperature difference between the first region and the second region obtained by a function of the flow rate and heat capacity of the fluid that contacts the region per unit time and the temperature of the fluid is given to the arithmetic expression to obtain the surface temperature of the first region. Calculate Surface temperature measurement wherein the.

A fluid controlled to a predetermined temperature is brought into contact with the vicinity of the first region for measuring the surface temperature of the moving measurement object, and the surface temperature of the second region in contact with the fluid is changed to emit radiation from the first region. The amount of infrared light and the amount of radiated infrared light from the second region are detected, and the influence of stray light noise in the amount of radiated infrared light from both regions is detected. In the surface temperature measurement method for calculating the surface temperature of the first region based on the calculation formula, a calculation formula for calculating the surface temperature of the first region is obtained by performing a calculation to remove by subtracting the movement of the measurement object The first region and the second region are detected by a function of the moving speed, the heat capacity of the first region, the flow rate and heat capacity of the fluid contacting the second region per unit time, and the temperature of the fluid. table Surface temperature measurement method characterized by calculating the surface temperature of the first region is given a temperature difference into the mathematical expression.