JP2016140911A

JP2016140911A - Plate thickness measuring method of checkered steel plate

Info

Publication number: JP2016140911A
Application number: JP2015021258A
Authority: JP
Inventors: 小林　直人; Naoto Kobayashi; 直人小林; 手塚　浩一; Koichi Tezuka; 浩一手塚
Original assignee: JFE Steel Corp
Current assignee: JFE Steel Corp
Priority date: 2015-02-05
Filing date: 2015-02-05
Publication date: 2016-08-08
Anticipated expiration: 2035-02-05
Also published as: JP6248960B2

Abstract

PROBLEM TO BE SOLVED: To provide a plate thickness measuring method capable of on-line measuring the plate thickness of a checkered steel plate having a plurality of projected parts cyclically formed obliquely in a rolling direction.SOLUTION: In order to on-line measure the plate thickness of a checkered steel plate 1 obtained by rolling at a hot rolling mill 10, a multi-channel type plate thickness meter 50 capable of simultaneously measuring the plate thickness of a checkered steel plate total width is installed on the exit side of the hot rolling mill 10, the total width plate thickness profile data of the checkered steel plate 1 is measured by the plate thickness meter 50, converted plate thickness profile data converted from the projected part arrangement specifications of the checkered steel plate is obtained in advance, and the error of the plate thickness of the checkered steel plate 1 is evaluated by comparing the total width plate thickness profile data with the converted plate thickness profile data.SELECTED DRAWING: Figure 5

Description

本発明は、鋼板表面に複数の突起部が、圧延方向に対して斜めに周期的に形成されている縞鋼板の板厚をオンラインで測定する縞鋼板の板厚測定方法および板厚測定装置に関する。 The present invention relates to a striped steel plate thickness measuring method and a plate thickness measuring apparatus for measuring the thickness of a striped steel plate having a plurality of protrusions formed on the steel plate surface periodically and obliquely with respect to the rolling direction. .

縞鋼板は、鋼板表面に複数の突起部が所定パターンで存在した鋼板であり、熱間圧延ラインにて模様付きの仕上圧延ロールによって圧延されてコイル状に巻き取られて製造される。従来、熱間圧延ラインにおいては、突起部が正しく形成されているか否かを確認するため、Ｘ線またはγ線板厚計を用いて板厚をオンラインで測定している。 A striped steel plate is a steel plate having a plurality of protrusions in a predetermined pattern on the surface of the steel plate, and is manufactured by being rolled by a patterned finish rolling roll in a hot rolling line and wound into a coil shape. Conventionally, in a hot rolling line, in order to confirm whether or not the protrusions are correctly formed, the plate thickness is measured online using an X-ray or γ-ray thickness gauge.

Ｘ線板厚計を用いて縞鋼板の板厚を測定する技術としては、特許文献１に記載された技術がある。特許文献１の技術は、突起部が圧延方向に沿って連続して存在している縞鋼板に対応したものであり、圧延機出側または中間に位置する板幅計の横振れ信号を用いて、Ｘ線板厚計であるＸ線Ｃフレームを板幅の横振れに追従して移動させることにより、常に突起部あるいは突起部間の底部の板厚を測定するものである。 As a technique for measuring the thickness of a striped steel sheet using an X-ray thickness gauge, there is a technique described in Patent Document 1. The technology of Patent Document 1 corresponds to a striped steel plate in which protrusions are continuously present in the rolling direction, and uses a lateral runout signal of a plate width meter located on the rolling mill exit side or in the middle. By moving the X-ray C frame, which is an X-ray plate thickness meter, following the lateral fluctuation of the plate width, the thickness of the projections or the bottom portion between the projections is always measured.

特開平９−３８７０６号公報JP-A-9-38706

しかし、複数の突起部が圧延方向に対して斜めに周期的に形成されている縞鋼板の場合、上記特許文献１の技術では、Ｘ線板厚計の検出器で放射線量を積算する時間（サンプリング時間）においてＸ線視野から突起部が外れてしまい、Ｘ線板厚計による突起部の板厚測定値が、突起部の実測板厚よりも小さくなるため、オンラインで板厚を測定することが困難である。このため、複数の突起部が圧延方向に対して斜めに形成されている縞鋼板の板厚測定は、オフライン位置での手測定で実施せざるを得ない。 However, in the case of a striped steel plate in which a plurality of protrusions are periodically formed obliquely with respect to the rolling direction, in the technique of Patent Document 1 described above, the time for integrating the radiation dose with the detector of the X-ray plate thickness gauge ( (Sampling time) The projection part is removed from the X-ray field of view, and the measured thickness value of the projection part by the X-ray thickness meter is smaller than the actual measured thickness of the projection part. Is difficult. For this reason, the thickness measurement of the striped steel plate in which the plurality of protrusions are formed obliquely with respect to the rolling direction must be carried out by manual measurement at an offline position.

したがって、本発明が解決しようとする課題は、複数の突起部が圧延方向に対して斜めに周期的に形成されている縞鋼板の板厚のオンライン測定を可能とする技術を提供することにある。 Therefore, the problem to be solved by the present invention is to provide a technique that enables on-line measurement of the thickness of a striped steel plate in which a plurality of protrusions are periodically formed obliquely with respect to the rolling direction. .

上記課題を解決するため、本発明は、以下の（１）〜（２０）を提供する。 In order to solve the above problems, the present invention provides the following (1) to (20).

（１）熱間圧延機で圧延して得られた縞鋼板の板厚をオンラインで測定する縞鋼板の板厚測定方法であって、
前記熱間圧延機の出側に縞鋼板全幅の板厚を同時測定可能な多チャンネルタイプの板厚計を設置し、前記板厚計で縞鋼板の全幅板厚プロファイルデータを測定し、
前記縞鋼板の突起部配置仕様から換算した換算板厚プロファイルデータをあらかじめ求めておき、前記全幅板厚プロファイルデータと前記換算板厚プロファイルデータとを比較することにより、前記縞鋼板の板厚の誤差を評価することを特徴とする縞鋼板の板厚測定方法。 (1) A method for measuring the thickness of a striped steel plate measured online by rolling with a hot rolling mill,
A multi-channel type thickness meter capable of simultaneously measuring the thickness of the striped steel plate full width on the outlet side of the hot rolling mill, and measuring the full width plate thickness profile data of the striped steel plate with the plate thickness meter,
The plate thickness error of the striped steel plate is obtained by calculating in advance the converted plate thickness profile data converted from the protruding portion arrangement specification of the striped steel plate, and comparing the full width plate thickness profile data with the converted plate thickness profile data. A method for measuring the thickness of a striped steel sheet, characterized in that

（２）前記換算板厚プロファイルデータは、最小の測定単位区画において、前記縞鋼板の前記突起部配置仕様から求めた板厚の換算値に基づいて求められることを特徴とする（１）に記載の縞鋼板の板厚測定方法。 (2) The conversion plate thickness profile data is obtained based on a conversion value of a plate thickness obtained from the projection arrangement specification of the striped steel plate in a minimum measurement unit section. Thickness measurement method for striped steel sheets.

（３）前記板厚計は、板厚方向に配列された複数の検出器を有し、前記最小の測定単位区画は、その前記縞鋼板の幅方向の長さが前記検出器の視野幅であり、その前記縞鋼板の圧延方向の長さが前記検出器のサンプリング期間中の鋼板移動距離であって、縞鋼板パターンの繰り返し最小単位であることを特徴とする（２）に記載の縞鋼板の板厚測定方法。 (3) The plate thickness meter has a plurality of detectors arranged in the plate thickness direction, and the minimum measurement unit section has a width direction length of the striped steel plate as a visual field width of the detector. The striped steel plate according to (2), wherein a length of the striped steel plate in a rolling direction is a steel plate moving distance during the sampling period of the detector, and is a repetitive minimum unit of the striped steel plate pattern. Thickness measurement method.

（４）前記全幅板厚プロファイルデータのうち鋼板幅方向の変位の影響を受けていないデータのみを抽出して縞鋼板の板厚の誤差を評価することを特徴とする（１）から（３）のいずれかに記載の縞鋼板の板厚測定方法。 (4) From (1) to (3), only the data that is not affected by the displacement in the steel plate width direction is extracted from the full width plate thickness profile data to evaluate the plate thickness error of the striped steel plate. The plate | board thickness measuring method of the striped steel plate in any one of.

（５）板厚測定の際のサンプリング時間内における縞鋼板の幅方向の変位量を検出し、その変位量があらかじめ設定された閾値よりも小さい場合に、鋼板幅方向の変位の影響を受けていないデータとみなすことを特徴とする（４）に記載の縞鋼板の板厚測定方法。 (5) When the amount of displacement in the width direction of the striped steel plate is detected within the sampling time when measuring the plate thickness, and the amount of displacement is smaller than a preset threshold value, it is affected by the displacement in the steel plate width direction. (4) The thickness measuring method of the striped steel plate according to (4), characterized in that it is regarded as no data.

（６）前記あらかじめ設定された閾値は、前記検出器の視野幅であることを特徴とする（５）に記載の縞鋼板の板厚測定方法。 (6) The striped steel sheet thickness measuring method according to (5), wherein the preset threshold value is a visual field width of the detector.

（７）縞鋼板の板厚を測定する測定周期ごとに前記全幅板厚プロファイルデータから検出した鋼板幅方向のエッジ位置を元に、鋼板幅方向の変位を算出することを特徴とする（４）から（６）のいずれかに記載の縞鋼板の板厚測定方法。 (7) The displacement in the steel plate width direction is calculated based on the edge position in the steel plate width direction detected from the full width plate thickness profile data for each measurement cycle for measuring the plate thickness of the striped steel plate (4). To (6).

（８）縞鋼板の板厚を測定する測定周期ごとに前記全幅板厚プロファイルデータから検出した鋼板幅方向のエッジ位置から算出した鋼板幅方向のセンタ位置を元に、鋼板幅方向の変位を算出することを特徴とする（４）から（６）のいずれかに記載の縞鋼板の板厚測定方法。 (8) The displacement in the steel plate width direction is calculated based on the center position in the steel plate width direction calculated from the edge position in the steel plate width direction detected from the full width plate thickness profile data at every measurement cycle for measuring the thickness of the striped steel plate. The method for measuring the thickness of a striped steel plate according to any one of (4) to (6), wherein:

（９）縞鋼板の板厚を測定する測定周期ごとに前記全幅板厚プロファイルデータから検出した鋼板幅方向のエッジ位置と、エッジ位置から算出した鋼板幅方向のセンタ位置とを元に、鋼板幅方向の変位を算出することを特徴とする（４）から（６）のいずれかに記載の縞鋼板の板厚測定方法。 (9) The steel plate width based on the edge position in the steel plate width direction detected from the full width plate thickness profile data and the center position in the steel plate width direction calculated from the edge position for each measurement cycle for measuring the plate thickness of the striped steel plate The method for measuring the thickness of a striped steel plate according to any one of (4) to (6), wherein a displacement in a direction is calculated.

（１０）前記板厚計は、Ｘ線板厚計またはγ線板厚計であることを特徴とする（１）から（９）のいずれかに記載の縞鋼板の板厚測定方法。 (10) The plate thickness measuring method according to any one of (1) to (9), wherein the plate thickness gauge is an X-ray thickness gauge or a γ-ray thickness gauge.

（１１）熱間圧延機で圧延して得られた縞鋼板の板厚をオンラインで測定する縞鋼板の板厚測定装置であって、
前記熱間圧延機の出側に設置された、縞鋼板全幅の板厚を同時測定可能な多チャンネルタイプの板厚計と、
前記縞鋼板の突起部配置仕様から換算した換算板厚プロファイルデータをあらかじめ求めておき、前記板厚計で測定した全幅板厚プロファイルデータと前記換算板厚プロファイルデータとを比較することにより、前記縞鋼板の板厚の誤差を評価する演算処理部と
を有することを特徴とする縞鋼板の板厚測定装置。 (11) A striped steel sheet thickness measuring device for measuring a striped steel sheet thickness obtained by rolling with a hot rolling mill online.
A multi-channel type thickness gauge installed on the outlet side of the hot rolling mill, capable of simultaneously measuring the thickness of the striped steel sheet full width,
By converting the converted plate thickness profile data converted from the projection arrangement specifications of the striped steel plate in advance, and comparing the full plate thickness profile data measured by the plate thickness meter with the converted plate thickness profile data, the stripes An apparatus for measuring the thickness of a striped steel sheet, comprising: an arithmetic processing unit that evaluates an error in the thickness of the steel sheet.

（１２）前記演算処理部は、最小の測定単位区画において、前記縞鋼板の前記突起部配置仕様から求めた板厚の換算値に基づいて前記換算板厚プロファイルデータを求めることを特徴とする（１１）に記載の縞鋼板の板厚測定装置。 (12) The arithmetic processing unit obtains the converted plate thickness profile data based on a converted value of the plate thickness obtained from the projection arrangement specification of the striped steel plate in a minimum measurement unit section ( The apparatus for measuring the thickness of a striped steel sheet according to 11).

（１３）前記板厚計は、板厚方向に配列された複数の検出器を有し、前記最小の測定単位区画は、その前記縞鋼板の幅方向の長さが前記検出器の視野幅であり、その前記縞鋼板の圧延方向の長さが前記検出器のサンプリング期間中の鋼板移動距離であって、縞鋼板パターンの繰り返し最小単位であることを特徴とする（１２）に記載の縞鋼板の板厚測定装置。 (13) The plate thickness meter has a plurality of detectors arranged in the plate thickness direction, and the minimum measurement unit section has a width direction length of the striped steel plate as a visual field width of the detector. The striped steel plate according to (12), wherein the length of the striped steel plate in the rolling direction is a steel plate moving distance during the sampling period of the detector and is a minimum repeating unit of the striped steel plate pattern. Plate thickness measuring device.

（１４）前記演算処理部は、前記全幅板厚プロファイルデータのうち鋼板幅方向の変位の影響を受けていないデータのみを抽出して縞鋼板の板厚の誤差を評価することを特徴とする（１１）から（１３）のいずれかに記載の縞鋼板の板厚測定装置。 (14) The arithmetic processing unit extracts only data that is not affected by the displacement in the steel plate width direction from the full width plate thickness profile data, and evaluates an error in the thickness of the striped steel plate ( The apparatus for measuring the thickness of a striped steel sheet according to any one of 11) to (13).

（１５）前記演算処理部は、板厚測定の際のサンプリング時間内における縞鋼板の幅方向の変位量を検出し、その変位量があらかじめ設定された閾値よりも小さい場合に、鋼板幅方向の変位の影響を受けていないデータとみなすことを特徴とする（１４）に記載の縞鋼板の板厚測定装置。 (15) The arithmetic processing unit detects a displacement amount in the width direction of the striped steel plate within a sampling time at the time of measuring the plate thickness, and when the displacement amount is smaller than a preset threshold value, The striped steel sheet thickness measuring apparatus according to (14), wherein the striped steel sheet thickness data is regarded as data not affected by the displacement.

（１６）前記演算処理部において、前記あらかじめ設定された閾値は、前記検出器の視野幅であることを特徴とする（１５）に記載の縞鋼板の板厚測定装置。 (16) The striped steel sheet thickness measuring apparatus according to (15), wherein in the arithmetic processing unit, the preset threshold is a visual field width of the detector.

（１７）前記演算処理部は、縞鋼板の板厚を測定する測定周期ごとに前記全幅板厚プロファイルデータから検出した鋼板幅方向のエッジ位置を元に、鋼板幅方向の変位を算出することを特徴とする（１４）から（１６）のいずれかに記載の縞鋼板の板厚測定装置。 (17) The arithmetic processing unit calculates the displacement in the steel plate width direction based on the edge position in the steel plate width direction detected from the full width plate thickness profile data for each measurement cycle for measuring the thickness of the striped steel plate. The strip thickness measuring apparatus for striped steel sheets according to any one of (14) to (16), which is characterized.

（１８）前記演算処理部は、縞鋼板の板厚を測定する測定周期ごとに前記全幅板厚プロファイルデータから検出した鋼板幅方向のエッジ位置から算出した鋼板幅方向のセンタ位置を元に、鋼板幅方向の変位を算出することを特徴とする（１４）から（１６）のいずれかに記載の縞鋼板の板厚測定装置。 (18) The arithmetic processing unit is a steel plate based on the center position in the steel plate width direction calculated from the edge position in the steel plate width direction detected from the full width plate thickness profile data for each measurement cycle for measuring the plate thickness of the striped steel plate. The striped steel sheet thickness measuring apparatus according to any one of (14) to (16), wherein a displacement in the width direction is calculated.

（１９）前記演算処理部は、縞鋼板の板厚を測定する測定周期ごとに前記全幅板厚プロファイルデータから検出した鋼板幅方向のエッジ位置と、エッジ位置から算出した鋼板幅方向のセンタ位置とを元に、鋼板幅方向の変位を算出することを特徴とする（１４）から（１６）のいずれかに記載の縞鋼板の板厚測定装置。 (19) The arithmetic processing unit includes an edge position in the steel plate width direction detected from the full width plate thickness profile data for each measurement period for measuring the plate thickness of the striped steel plate, and a center position in the steel plate width direction calculated from the edge position. The thickness measuring device for a striped steel plate according to any one of (14) to (16), wherein a displacement in the steel plate width direction is calculated based on

（２０）前記板厚計は、Ｘ線板厚計またはγ線板厚計であることを特徴とする（１１）から（１９）のいずれかに記載の縞鋼板の板厚測定装置。 (20) The strip thickness measuring apparatus according to any one of (11) to (19), wherein the thickness gauge is an X-ray thickness gauge or a γ-ray thickness gauge.

本発明では、縞鋼板の突起部配置仕様から換算した換算板厚プロファイルデータをあらかじめ求めておき、全幅板厚プロファイルデータと換算板厚プロファイルデータとを比較することにより、縞鋼板の板厚の誤差を評価する。このため、複数の突起部が圧延方向に対して斜めに規則的に形成されている縞鋼板の板厚のオンライン測定が可能となる。 In the present invention, the converted plate thickness profile data converted from the protruding portion arrangement specification of the striped steel plate is obtained in advance, and by comparing the full width plate thickness profile data with the converted plate thickness profile data, an error in the striped steel plate thickness error is obtained. To evaluate. For this reason, the on-line measurement of the plate | board thickness of the striped steel plate in which several protrusion parts are regularly formed diagonally with respect to the rolling direction is attained.

本発明の一実施形態に係る縞鋼板の板厚測定方法が適用される板厚測定装置を備えた熱間圧延設備を示す概略図である。It is the schematic which shows the hot rolling equipment provided with the plate | board thickness measuring apparatus with which the plate | board thickness measuring method of the striped steel plate which concerns on one Embodiment of this invention is applied. 図１の熱間圧延設備に設けられた板厚測定装置の板厚計を示す概略図である。It is the schematic which shows the plate | board thickness meter of the plate | board thickness measuring apparatus provided in the hot rolling installation of FIG. 図２の板厚計により縞鋼板の板厚を測定している状態を説明するための図である。It is a figure for demonstrating the state which is measuring the plate | board thickness of a striped steel plate with the plate | board thickness meter of FIG. Ｘ線板厚計において得られる縞鋼板の板厚プロファイルを模式的に示す図である。It is a figure which shows typically the plate | board thickness profile of the striped steel plate obtained in an X-ray plate thickness meter. 本発明の一実施形態における縞鋼板の板厚測定の原理を説明するために縞鋼板の一例を示す平面図である。It is a top view which shows an example of a striped steel plate in order to demonstrate the principle of the plate | board thickness measurement of the striped steel plate in one Embodiment of this invention. 縞鋼板に蛇行等の幅方向の変位が生じた場合の板厚測定方法を説明するための図である。It is a figure for demonstrating the plate | board thickness measuring method when the displacement of width directions, such as meandering, arises in the striped steel plate. 本発明が適用される縞鋼板の他の例を示す平面図である。It is a top view which shows the other example of the striped steel plate to which this invention is applied. 本発明の実施例に適用した縞鋼板の突起部の配置および寸法を示す平面図およびＡ−Ａ断面図である。It is the top view and AA sectional drawing which show arrangement | positioning and a dimension of the projection part of the striped steel plate applied to the Example of this invention. 図８の縞鋼板の板厚プロファイルデータを示す図である。It is a figure which shows the plate | board thickness profile data of the striped steel plate of FIG.

以下、添付図面を参照して本発明の実施の形態について説明する。
図１は、本発明の一実施形態に係る縞鋼板の板厚測定方法が適用される板厚測定装置を備えた熱間圧延設備を示す概略図である。この熱間圧延設備は、７台の仕上圧延機（Ｆ１〜Ｆ７）を備えた仕上圧延機群１０で圧延して得られた縞鋼板１を、ランナウトテーブル２０で冷却した後、巻取設備３０で巻取るものであり、仕上圧延機群１０の出側に板厚測定装置４０を有している。板厚測定装置４０は、板厚計５０と、板厚計５０からの測定信号を演算処理する演算処理部６０とを有している。 Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.
FIG. 1 is a schematic view showing a hot rolling facility equipped with a plate thickness measuring device to which a strip thickness measuring method for a striped steel plate according to an embodiment of the present invention is applied. In this hot rolling facility, after the striped steel plate 1 obtained by rolling with a finishing mill group 10 including seven finishing rolling mills (F1 to F7) is cooled by the runout table 20, the winding facility 30 is used. The sheet thickness measuring device 40 is provided on the exit side of the finish rolling mill group 10. The plate thickness measuring device 40 includes a plate thickness meter 50 and an arithmetic processing unit 60 that performs arithmetic processing on the measurement signal from the plate thickness meter 50.

仕上圧延機群１０は、粗圧延機群によって粗圧延された鋼板を７台の仕上圧延機（Ｆ１〜Ｆ７）で仕上圧延して、適当な板厚の縞鋼板１を得るものであり、例えば、最終の仕上圧延機（Ｆ７）に溝付きロールを組み込んで、複数の突起部が形成された縞鋼板１を形成する。複数の突起部は、圧延方向に対して斜めにかつ周期的に形成されている。 The finish rolling mill group 10 is obtained by finishing and rolling the steel sheet roughly rolled by the rough rolling mill group with seven finishing mills (F1 to F7) to obtain a striped steel sheet 1 having an appropriate thickness. A striped steel sheet 1 having a plurality of protrusions is formed by incorporating a grooved roll into the final finishing mill (F7). The plurality of protrusions are formed obliquely and periodically with respect to the rolling direction.

板厚測定装置４０の板厚計５０は、Ｘ線板厚計として構成されており、図２にも示すように、Ｃフレーム５１と、Ｃフレーム５１の上側フレーム５１ａの内部に設けられたＸ線源５２と、Ｃフレーム５１の下側フレーム５１ｂの内部に設けられた検出部５３とを有し、縞鋼板１の全幅の板厚を同時測定可能な多チャンネルタイプとして構成されている。すなわち、検出部５３は板幅方向に配列された複数の検出器５４を有しており、図３に示すように、Ｘ線源５２から放射状に射出され、縞鋼板１を透過したＸ線が各検出器５４により検出され、これにより縞鋼板１の全幅同時に板厚測定可能となる。したがって、連続して通板される縞鋼板１の板厚プロファイルを全幅同時に測定することができる。検出部５３の各検出器５４は、所定のサンプリング時間内にサンプリングされたＸ線に基づいて板厚を計測する。このときのＸ線は放射状をなし、放射角度により板厚の測定値に誤差を生じるため、板厚の角度補正を行う。なお、板厚計５０として、Ｘ線の代わりにγ線を用いたγ線板厚計を用いてもよい。 The plate thickness meter 50 of the plate thickness measuring device 40 is configured as an X-ray plate thickness meter, and as shown in FIG. 2, the X frame provided in the C frame 51 and the upper frame 51a of the C frame 51 is provided. It has a radiation source 52 and a detection unit 53 provided inside the lower frame 51b of the C frame 51, and is configured as a multi-channel type capable of simultaneously measuring the full thickness of the striped steel plate 1. That is, the detection unit 53 has a plurality of detectors 54 arranged in the plate width direction. As shown in FIG. 3, X-rays emitted radially from the X-ray source 52 and transmitted through the striped steel plate 1 Detected by each detector 54, the thickness of the striped steel plate 1 can be measured simultaneously. Therefore, it is possible to simultaneously measure the full thickness of the strip thickness profile of the striped steel plate 1 that is continuously passed. Each detector 54 of the detector 53 measures the plate thickness based on the X-rays sampled within a predetermined sampling time. Since the X-rays at this time are radial and an error occurs in the measured value of the plate thickness depending on the radiation angle, the plate thickness angle is corrected. As the thickness gauge 50, a γ-ray thickness gauge using γ rays instead of X rays may be used.

縞鋼板１は、突起部が圧延方向に対して斜めに形成されているため、特許文献１のように突起部あるいは突起部間の平坦部（底部）の板厚を直接的にオンライン測定することは困難である。そこで、本実施形態では、板厚計５０で縞鋼板１の全幅板厚プロファイルデータを測定し、演算処理部６０において、この全幅板厚プロファイルデータと、あらかじめ求められた縞鋼板１の突起部配置仕様から換算した換算板厚プロファイルデータとを比較し、縞鋼板１の実際の板厚（実板厚）を評価（測定）する。具体的には、目標板厚からの偏差（誤差）を評価する。 Since the striped steel plate 1 has the protrusions formed obliquely with respect to the rolling direction, the plate thickness of the protrusions or the flat part (bottom part) between the protrusions is directly measured online as in Patent Document 1. It is difficult. Therefore, in the present embodiment, the full width plate thickness profile data of the striped steel plate 1 is measured by the plate thickness meter 50, and the calculation processing unit 60 determines the full width plate thickness profile data and the protrusion arrangement of the striped steel plate 1 obtained in advance. The converted plate thickness profile data converted from the specification is compared, and the actual plate thickness (actual plate thickness) of the striped steel plate 1 is evaluated (measured). Specifically, the deviation (error) from the target plate thickness is evaluated.

以下具体的に説明する。
板厚計５０で縞鋼板の板厚を測定する際、検出器５４のＸ線測定にかかるサンプリング時間内においてＸ線視野に突起部と平坦部の両方をＸ線が透過するため、得られる板厚プロファイルは、図４に模式的に示すように、板厚の測定値は突起部２の実板厚よりも低く測定されて板厚プロファイルは平坦化する。また、図５に示すように、圧延方向に対して斜めにかつ周期的に突起部２が形成された縞鋼板１においては、突起部２の周期的形状の差異から、Ａ、Ｂ、Ｃで示す最小の測定単位区画では測定値に偏差が生じる。このため、板厚計５０により、実際の板厚よりも小さい値でかつ周期的に変化する全幅板厚プロファイルデータを得ることができる。 This will be specifically described below.
When measuring the plate thickness of the striped steel plate with the plate thickness meter 50, the X-ray passes through both the projection and the flat portion in the X-ray field within the sampling time required for the X-ray measurement of the detector 54. As schematically shown in FIG. 4, the measured thickness value is measured lower than the actual thickness of the protrusion 2, and the thickness profile is flattened. Moreover, as shown in FIG. 5, in the striped steel plate 1 in which the protrusions 2 are formed obliquely and periodically with respect to the rolling direction, the difference in the periodic shape of the protrusions 2 indicates that A, B, and C In the smallest unit of measurement shown, deviations occur in the measured values. For this reason, the thickness gauge 50 can obtain full width plate thickness profile data that is smaller than the actual plate thickness and periodically changes.

一方、鋼板が蛇行していないと仮定した場合、縞鋼板１内の板幅方向長さがｘ、圧延方向長さがｙの長方形の測定単位区画（ｘ_ｍｉｍ≦ｘ≦ｘ_ｍａｘ，ｙ_ｍｉｍ≦ｙ≦ｙ_ｍａｘ）における突起部高さの板厚計５０による測定値Ｈ_Measureと実測値Ｈ_actualとの間には、以下の（１）式に示す関係が成立する。 On the other hand, when it is assumed that the steel plate is not meandering, a rectangular measurement unit section (x _mim ≤ x ≤ x _max , y _mim ≤ The relationship shown in the following formula (1) is established between the measured value H _Measure of the height of the protrusion in the thickness gauge 50 at y ≦ y _max ) and the actual measured value H _actual .

したがって、縞鋼板１の突起部配置仕様において設定された突起部２の配置に基づいて、上記（１）式から上述した最小の測定単位区画Ａ，Ｂ，Ｃの板厚の換算値（（１）式のＨ_Measure）を求めることにより、換算板厚プロファイルデータを得ることができる。そして、このようにして求めた換算板厚プロファイルデータと全幅板厚プロファイルデータを比較することにより、縞鋼板の突起部および平坦部の実板厚の誤差（すなわち、目標板厚からの偏差）を評価（測定）することができる。

Therefore, based on the arrangement of the protrusions 2 set in the protrusion arrangement specification of the striped steel plate 1, the converted value of the plate thicknesses of the minimum measurement unit sections A, B, and C ((1 The calculated plate thickness profile data can be obtained by obtaining H _Measure ). Then, by comparing the converted plate thickness profile data thus obtained and the full width plate thickness profile data, the error of the actual plate thickness of the protruding portion and the flat portion of the striped steel plate (that is, the deviation from the target plate thickness) is obtained. It can be evaluated (measured).

上記最小の測定単位区画は、その幅方向の長さが一つの検出器５４に対応する長さであり、その圧延方向の長さが繰り返しパターンが得られる最小長さである。すなわち、縞鋼板は同じパターンが繰り返されるものであるため、圧延方向の最小長さを繰り返しパターンの最小単位に定めれば、板厚の換算値は、同一のＸ線視野のもとでは、圧延方向に関しては、常に同じ値となる。一方、板幅方向の位置により圧延方向のパターンが変わるので、板幅方向の板厚の換算値は板幅方向の位置により変化する。本実施形態の板厚計５０においては、最小の測定単位区画は、その幅方向の長さが検出器５４のＸ線視野幅であり、その圧延方向の長さがサンプリング周期中の鋼板移動距離である。したがって、サンプリング期間中の鋼板移動距離が、圧延方向の繰り返しパターンの最小単位になるようにする。以上により、高精度で図５に示すような突起部２が圧延方向に対して斜めにかつ周期的に形成された縞鋼板１の板厚の誤差を評価することができる。 The minimum measurement unit section has a length in the width direction corresponding to one detector 54, and a length in the rolling direction is a minimum length at which a repeated pattern can be obtained. That is, since the same pattern is repeated in the striped steel plate, if the minimum length in the rolling direction is set as the minimum unit of the repeating pattern, the converted value of the plate thickness is rolled under the same X-ray field of view. The direction is always the same value. On the other hand, since the pattern in the rolling direction varies depending on the position in the sheet width direction, the converted value of the sheet thickness in the sheet width direction varies depending on the position in the sheet width direction. In the thickness gauge 50 of the present embodiment, the minimum measurement unit section has a width direction length that is the X-ray field width of the detector 54, and the rolling direction length is the steel plate moving distance during the sampling period. It is. Therefore, the steel plate moving distance during the sampling period is set to be the minimum unit of the repeating pattern in the rolling direction. As described above, it is possible to evaluate a plate thickness error of the striped steel plate 1 in which the protruding portions 2 as shown in FIG. 5 are formed obliquely and periodically with respect to the rolling direction with high accuracy.

以上の板厚測定は、縞鋼板に蛇行やキャンバー等による幅方向の変位が存在していないか極めて小さい場合にはそのまま適用することが可能である。ただし、縞鋼板に蛇行やキャンバー等による幅方向の変位が生じた場合は、縞鋼板１は幅方向に変位しながら板厚計５０を通過するため、サンプリング時間内でＸ線視野が幅方向に変動して突起部の板厚測定精度が低下してしまう。 The above plate thickness measurement can be applied as it is when the striped steel plate has no or very small displacement in the width direction due to meandering or camber. However, if the striped steel plate is displaced in the width direction due to meandering or camber, the striped steel plate 1 passes through the thickness gauge 50 while being displaced in the width direction. It will fluctuate and the plate thickness measurement accuracy of the projection will be reduced.

そこで、蛇行等の幅方向の変位が生じる場合には、以下に説明するように、演算処理部６０において、蛇行等の幅方向の変位が小さいデータのみを抽出する。 Therefore, when a displacement in the width direction such as meandering occurs, the arithmetic processing unit 60 extracts only data having a small displacement in the width direction such as meandering as described below.

図６を参照して、その手法について説明する。
演算処理部６０では、板厚計５０の板幅方向に複数配列された検出器５４によりサンプリング時間単位ごとに測定された全幅板厚プロファイルＴ（ｘ、ｓ）の板厚変位から、図６（ａ）に示すように、幅方向における左右の鋼板エッジ位置Ｅｌ（ｓ）、Ｅｒ（ｓ）を検出し、これらのエッジ位置Ｅｌ（ｓ）、Ｅｒ（ｓ）に基づいて、鋼板センタ位置Ｃｅ（ｓ）をＣｅ（ｓ）＝｛Ｅｌ（ｓ）−Ｅｒ（ｓ）｝／２として計算する。ここで、ｘはライン幅方向における位置、ｓはサンプリングＮｏ．を示す。 The method will be described with reference to FIG.
In the arithmetic processing unit 60, from the plate thickness displacement of the full width plate thickness profile T (x, s) measured for each sampling time unit by a plurality of detectors 54 arranged in the plate width direction of the plate thickness meter 50, FIG. As shown in a), left and right steel plate edge positions El (s) and Er (s) in the width direction are detected, and based on these edge positions El (s) and Er (s), a steel plate center position Ce ( s) is calculated as Ce (s) = {El (s) −Er (s)} / 2. Here, x is a position in the line width direction, and s is a sampling number. Indicates.

このＣｅ（ｓ）に基づいて、サンプリング時間単位ごとの縞鋼板の蛇行等による縞鋼板の幅方向変位量Ｍ（ｓ）＝Ｃｅ（ｓ）−Ｃｅ（ｓ−１）を求める。この幅方向変位量Ｍ（ｓ）を検出器のＸ線視野幅αと比較する。図６（ｂ）に示すように、サンプリング時間内においてＸ線視野幅αよりも鋼板の蛇行等による幅方向変位量Ｍ（ｓ）が小さいデータは、幅方向の変位の影響が小さく精度の高いデータと判定することができ、一方、サンプリング時間内においてＸ線視野幅αよりも幅方向変位量Ｍ（ｓ）が大きいデータは、幅方向の変位の影響が大きく精度の低いデータと判定することができる。一般的に、縞鋼板の蛇行等による幅方向の変位は、縞鋼板が幅方向の片側方向のみではなく、両側方向に移動するため、必ず幅方向の変位がない部分が発生する。このため、サンプリング時間内において少なくとも１か所で蛇行等の影響がないデータを得ることができる。したがって、幅方向変位量Ｍ（ｓ）とＸ線視野幅αを比較して、蛇行等の影響があるα≦Ｍ（ｓ）のデータを除外し、蛇行等の影響を受けていないとみなせるα＞Ｍ（ｓ）のデータのみを抽出する。これにより、縞鋼板に蛇行等の幅方向の変位が生じても、高精度で板厚の誤差の評価を行うことができる。 Based on this Ce (s), the width direction displacement amount M (s) = Ce (s) −Ce (s−1) of the striped steel plate due to the meandering of the striped steel plate for each sampling time unit is obtained. This width direction displacement amount M (s) is compared with the X-ray field width α of the detector. As shown in FIG. 6B, the data in which the displacement amount M (s) in the width direction due to the meandering of the steel sheet is smaller than the X-ray field width α within the sampling time is less affected by the displacement in the width direction and is highly accurate. On the other hand, data having a larger displacement amount M (s) in the width direction than the X-ray field width α within the sampling time is determined to be data having a large influence of displacement in the width direction and low accuracy. Can do. Generally, the displacement in the width direction due to the meandering of the striped steel plate is not limited to one side in the width direction, but moves in both directions, so that a portion without any displacement in the width direction always occurs. For this reason, the data which does not have influence of meandering etc. can be obtained in at least one place within the sampling time. Accordingly, the amount of displacement M (s) in the width direction is compared with the X-ray field width α, and data of α ≦ M (s) that has an influence of meandering is excluded, and α that can be regarded as not affected by meandering etc. Only data of> M (s) is extracted. Thereby, even if the displacement in the width direction such as meandering occurs in the striped steel plate, the error of the plate thickness can be evaluated with high accuracy.

以上のように、本実施形態によれば、縞鋼板の全幅の板厚を同時測定可能な多チャンネルタイプの板厚計を用いて縞鋼板の全幅板厚プロファイルデータを測定し、この全幅板厚プロファイルデータと、事前に求めた縞鋼板１の突起部配置仕様から換算した換算板厚プロファイルデータとを比較し、縞鋼板１の実際の板厚と目標板厚との偏差（誤差）を評価する。このため、縞鋼板１の突起部２が圧延方向に対して斜めに形成された場合であっても、高精度で板厚の誤差を評価することができる。 As described above, according to the present embodiment, the full width plate thickness profile data of the striped steel plate is measured using a multi-channel type thickness meter capable of simultaneously measuring the full thickness of the striped steel plate. The profile data is compared with the converted plate thickness profile data converted from the protrusion arrangement specifications of the striped steel plate 1 obtained in advance, and the deviation (error) between the actual plate thickness and the target plate thickness of the striped steel plate 1 is evaluated. . For this reason, even if it is a case where the projection part 2 of the striped steel plate 1 is formed diagonally with respect to the rolling direction, an error in the plate thickness can be evaluated with high accuracy.

また、全幅板厚プロファイルデータのうち縞鋼板の蛇行等による幅方向の変位の影響を受けているデータを除外し、幅方向の変位の影響を受けていないデータのみを抽出して縞鋼板の板厚を求めるので、蛇行等による幅方向の変位が生じても、測定精度低下が生じることなく高精度で縞鋼板の板厚（板厚の誤差）を評価することができる。 In addition, stripped steel sheet plates are extracted by excluding data that is affected by the displacement in the width direction due to meandering of the striped steel plate from the full width plate thickness profile data, and extracting only the data that is not affected by the displacement in the width direction. Since the thickness is obtained, even if the displacement in the width direction due to meandering or the like occurs, the plate thickness (plate thickness error) of the striped steel plate can be evaluated with high accuracy without causing a decrease in measurement accuracy.

なお、本発明は上記実施形態に限定されることなく種々変形が可能である。例えば縞鋼板の突起部の配置形態は上記実施形態に例示したものに限るものではなく、例えば図７に示すような配置形態等、他の配置形態であってもよい。また、上記実施形態において、全幅板厚プロファイルの求め方はあくまでも例示であってこれに限るものではない。 The present invention is not limited to the above-described embodiment, and various modifications can be made. For example, the arrangement form of the protrusions of the striped steel plate is not limited to that illustrated in the above embodiment, and may be another arrangement form such as an arrangement form shown in FIG. Moreover, in the said embodiment, the method of calculating | requiring a full width board thickness profile is an illustration to the last, and is not restricted to this.

また、上記実施形態では、幅方向変位量を把握するために、鋼板センタ位置Ｃｅ（ｓ）を用いたが、幅板厚プロファイルの板厚変位から検出した鋼板エッジ位置Ｅｌ（ｓ）、Ｅｒ（ｓ）をそのまま用いてもよく、センタ位置とエッジ位置の両方を同時に用いてもよい。また、幅方向変位の閾値としてＸ線視野幅αを用いたが、これに限るものではない。 In the above embodiment, the steel plate center position Ce (s) is used to grasp the amount of displacement in the width direction, but the steel plate edge positions El (s), Er () detected from the plate thickness displacement of the width plate thickness profile. s) may be used as it is, or both the center position and the edge position may be used simultaneously. Further, although the X-ray field width α is used as the threshold value for the width direction displacement, the present invention is not limited to this.

さらに、上記実施形態では、多チャンネル板厚計の光源が一つの場合について示したが、光源が複数であってもよい。さらにまた、上記実施形態では、多チャンネルの板厚計としてＸ線板厚計またはγ線板厚計を用いた場合を示したが、これに限らずレーザー板厚計等の他の板厚計を用いることもできる。 Furthermore, although the case where the number of light sources of the multi-channel plate thickness meter is one is shown in the above embodiment, a plurality of light sources may be used. Furthermore, in the above-described embodiment, the case where an X-ray thickness gauge or a γ-ray thickness gauge is used as a multi-channel thickness gauge is shown, but not limited to this, other thickness gauges such as a laser thickness gauge are used. Can also be used.

以下、本発明の実施例について説明する。ここでは、Ｘ線視野幅が４ｍｍであり、全幅同時に板厚測定可能な多チャンネルタイプのＸ線板厚計を使用し、圧延方向に対して斜めの複数の突起部が図５と同様に配置された縞鋼板の板厚測定を行った。図８は、その縞鋼板の突起部の配置および寸法を示す平面図およびＡ−Ａ断面図である。図８に示すように、突起部の幅は６ｍｍ、長さは２６ｍｍである。Ｘ線板厚測定の測定単位区画としては、図８に示すＡ、Ｂ、Ｃに示すものを用い、蛇行影響を受けていないデータを自動的に抽出し、蛇行の影響を排除して縞鋼板全幅の板厚測定を行った。その際の縞鋼板の板厚測定結果を図９に示す。図９に示すように、測定単位区画Ａ、Ｂ、Ｃに対応するように測定値に偏差が生じて複数のピークが発生した。ピーク高さ（偏差）は１４０μｍでありピーク間隔は２８．２ｍｍであった。また、縞鋼板の突起部配置仕様において設定された突起部の配置に基づいて、事前に上記（１）式から測定単位区画Ａ、Ｂ、Ｃにおける換算値を算出しておき、板厚測定結果と比較した結果、測定結果の偏差と測定単位区画Ａ、Ｂ、Ｃにおける換算値の偏差が一致した結果となり、測定単位区画Ａ、Ｂの間隔と板厚プロファイルのピーク間隔も同様に一致した。このことから、縞鋼板の突起部の板厚が設定通りであることが確認された。 Examples of the present invention will be described below. Here, an X-ray field width is 4 mm, and a multi-channel type X-ray thickness meter capable of measuring the thickness simultaneously at the full width is used, and a plurality of protrusions oblique to the rolling direction are arranged as in FIG. The thickness of the striped steel sheet was measured. FIG. 8 is a plan view and an AA cross-sectional view showing the arrangement and dimensions of the protrusions of the striped steel plate. As shown in FIG. 8, the protrusion has a width of 6 mm and a length of 26 mm. As the measurement unit section of the X-ray plate thickness measurement, those shown in A, B, and C shown in FIG. 8 are used, data that is not affected by meandering is automatically extracted, and the effect of meandering is eliminated, thereby striped steel plate. The thickness of the full width was measured. The thickness measurement result of the striped steel plate in that case is shown in FIG. As shown in FIG. 9, a plurality of peaks occurred due to deviations in the measured values corresponding to the measurement unit sections A, B, and C. The peak height (deviation) was 140 μm and the peak interval was 28.2 mm. Moreover, based on the protrusion arrangement set in the protrusion arrangement specification of the striped steel plate, the converted values in the measurement unit sections A, B, and C are calculated in advance from the above equation (1), and the plate thickness measurement result As a result, the deviation of the measurement result and the deviation of the converted value in the measurement unit sections A, B, and C coincided with each other, and the interval between the measurement unit sections A and B and the peak interval of the plate thickness profile also coincided. From this, it was confirmed that the plate | board thickness of the protrusion part of a striped steel plate is as the setting.

１縞鋼板
２突起部
１０仕上圧延機群
２０ランナウトテーブル
３０巻取設備
４０板厚測定装置
５０板厚計
５１Ｃフレーム
５２Ｘ線源
５３検出部
５４検出器
６０演算処理部
Ａ，Ｂ，Ｃ；測定単位区画 DESCRIPTION OF SYMBOLS 1 Striped steel plate 2 Protruding part 10 Finishing mill group 20 Runout table 30 Winding equipment 40 Plate thickness measuring device 50 Plate thickness meter 51 C frame 52 X-ray source 53 Detector 54 Detector 60 Arithmetic processor A, B, C; Measurement unit section

Claims

A method for measuring the thickness of a striped steel sheet obtained by rolling on a hot rolling mill online,
A multi-channel type thickness meter capable of simultaneously measuring the thickness of the striped steel plate full width on the outlet side of the hot rolling mill, and measuring the full width plate thickness profile data of the striped steel plate with the plate thickness meter,
The plate thickness error of the striped steel plate is obtained by calculating in advance the converted plate thickness profile data converted from the protruding portion arrangement specification of the striped steel plate, and comparing the full width plate thickness profile data with the converted plate thickness profile data. A method for measuring the thickness of a striped steel sheet, characterized in that

2. The striped steel sheet according to claim 1, wherein the converted sheet thickness profile data is obtained based on a converted value of a sheet thickness obtained from the projection arrangement specification of the striped steel sheet in a minimum measurement unit section. Thickness measurement method.

The thickness gauge has a plurality of detectors arranged in the thickness direction, and the minimum measurement unit section has a width in the width direction of the striped steel plate that is a visual field width of the detector. The strip thickness of the striped steel plate according to claim 2, wherein a length of the striped steel plate in a rolling direction is a steel plate moving distance during a sampling period of the detector, and is a repetitive minimum unit of the striped steel plate pattern. Measuring method.

4. The error in the thickness of the striped steel sheet is evaluated by extracting only data that is not affected by the displacement in the steel sheet width direction from the full width sheet thickness profile data. 5. 2. A method for measuring the thickness of a striped steel sheet according to item 1.

When the displacement amount in the width direction of the striped steel plate is detected within the sampling time when measuring the plate thickness, and the displacement amount is smaller than a preset threshold value, the data not affected by the displacement in the steel plate width direction The thickness measuring method of the striped steel plate according to claim 4, characterized in that it is regarded.

6. The thickness measuring method for a striped steel sheet according to claim 5, wherein the preset threshold value is a visual field width of the detector.

5. The displacement in the steel plate width direction is calculated based on the edge position in the steel plate width direction detected from the full width plate thickness profile data for each measurement period for measuring the plate thickness of the striped steel plate. 6. A method for measuring the thickness of a striped steel sheet according to any one of items 6 to 6.

Calculating the displacement in the steel plate width direction based on the center position in the steel plate width direction calculated from the edge position in the steel plate width direction detected from the full width plate thickness profile data for each measurement cycle for measuring the plate thickness of the striped steel plate. The thickness measuring method of the striped steel plate according to any one of claims 4 to 6, characterized by the above.

Displacement in the steel plate width direction based on the edge position in the steel plate width direction detected from the full width plate thickness profile data and the center position in the steel plate width direction calculated from the edge position for each measurement cycle for measuring the thickness of the striped steel plate The thickness measuring method for a striped steel sheet according to any one of claims 4 to 6, wherein the thickness is calculated.

The strip thickness steel sheet thickness measuring method according to any one of claims 1 to 9, wherein the thickness gauge is an X-ray thickness gauge or a γ-ray thickness gauge.

A strip thickness measuring device for striped steel sheets that measures the thickness of striped steel sheets obtained by rolling with a hot rolling mill online.
A multi-channel type thickness gauge installed on the outlet side of the hot rolling mill, capable of simultaneously measuring the thickness of the striped steel sheet full width,
By converting the converted plate thickness profile data converted from the projection arrangement specifications of the striped steel plate in advance, and comparing the full plate thickness profile data measured by the plate thickness meter with the converted plate thickness profile data, the stripes An apparatus for measuring the thickness of a striped steel sheet, comprising: an arithmetic processing unit that evaluates an error in the thickness of the steel sheet.

The calculation processing unit obtains the converted plate thickness profile data based on a converted value of the plate thickness obtained from the projection arrangement specification of the striped steel plate in a minimum measurement unit section. Apparatus for measuring the thickness of a striped steel sheet according to the description.

The thickness gauge has a plurality of detectors arranged in the thickness direction, and the minimum measurement unit section has a width in the width direction of the striped steel plate that is a visual field width of the detector. The strip thickness of the striped steel plate according to claim 12, wherein a length of the striped steel plate in a rolling direction is a steel plate moving distance during a sampling period of the detector, and is a repetitive minimum unit of the striped steel plate pattern. measuring device.

The calculation processing unit extracts only data that is not affected by the displacement in the steel plate width direction from the full width plate thickness profile data and evaluates an error in the plate thickness of the striped steel plate. The plate | board thickness measuring apparatus of the striped steel plate of any one of Claim 13.

The arithmetic processing unit detects the amount of displacement in the width direction of the striped steel plate within the sampling time when measuring the plate thickness, and when the amount of displacement is smaller than a preset threshold value, the influence of the displacement in the steel plate width direction The striped steel sheet thickness measuring apparatus according to claim 14, wherein the striped steel sheet thickness data is regarded as data that has not been received.

In the said arithmetic processing part, the said preset threshold value is the visual field width of the said detector, The plate | board thickness measuring apparatus of the striped steel plate of Claim 15 characterized by the above-mentioned.

The arithmetic processing unit calculates the displacement in the steel plate width direction based on the edge position in the steel plate width direction detected from the full width plate thickness profile data for each measurement period for measuring the plate thickness of the striped steel plate. The strip thickness measuring apparatus of a striped steel plate according to any one of claims 14 to 16.

The arithmetic processing unit, based on the center position in the steel plate width direction calculated from the edge position in the steel plate width direction detected from the full width plate thickness profile data for each measurement cycle for measuring the plate thickness of the striped steel plate, The displacement measuring device according to any one of claims 14 to 16, wherein the displacement is calculated.

The arithmetic processing unit is based on the edge position in the steel sheet width direction detected from the full width sheet thickness profile data and the center position in the steel sheet width direction calculated from the edge position for each measurement cycle for measuring the thickness of the striped steel sheet. The thickness measurement apparatus of the striped steel plate according to any one of claims 14 to 16, wherein a displacement in a steel plate width direction is calculated.

20. The striped steel sheet thickness measuring apparatus according to claim 11, wherein the thickness gauge is an X-ray thickness gauge or a γ-ray thickness gauge.