JP2004001068A - Method for rolling plate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a plate rolling method for performing a rolling operation so that extending ratios of a rolled material at the right and the left sides become the uniformity. <P>SOLUTION: In the rolling method using multi-high plate rolling mill having ≥ four-high mill, either one or both of zero point of a rolling reduction device and a deforming characteristic of the rolling mill, are obtained from the measured values of reaction forces of backup rolls acted to the rolling reduction direction in the respective rolling reductional supporting positions of the upper and the lower backup rolls under contacting state of both working rolls. <P>COPYRIGHT: (C)2004,JPO

Description

以上の式（９）〜（１６）を連立して解くことにより、上述の未知数が演算される。尚、図７中の補強ロールに作用するスラスト反力の作用点位置と補強ロール軸心位置との距離ｈ_Ｂ ^Ｔおよびｈ_Ｂ ^Ｂは、例えば、既知のスラスト力を与えて補強ロール反力変化を観察することで予め同定しておくものとする。
【００２１】
次に、本発明の請求項３の板圧延方法で、予め求めておいた定数を使用して、各ロールの変形量の左右差を演算する際に必要となる各ロール間に作用するスラスト力および線荷重分布の左右差を演算する方法を説明する。上述のように、上下・左右の補強ロール反力が測定可能な場合と、上下どちらか一方の左右の補強ロール反力および上下作業ロールのスラスト反力が測定可能な場合で、未知数が前者では２個、後者では１個超過してしまい方程式を解くことができない。本発明の請求項３では、例えば、次のような仮定をおいて新たな条件式を導入するものとする。
（ａ）ロール間クロス角とロール間スラスト力は比例する。
（ｂ）１圧延単位中で変化するのは作業ロールの微小クロス角である。
（ｃ）上下補強ロールの相対的クロス角は１圧延単位中変化しない。
上記（ａ）の仮定はクロス角が微小な場合には良い精度で成立することが実験的に確認されている。尚、補強ロール〜作業ロール間と上下作業ロール間では摩擦係数が異なる可能性があるが、これ以上変数を増やすことはできないので、ここでは摩擦係数すなわちロール間クロス角とロール間スラスト力との比例定数は一定と仮定する。また、（ｂ）、（ｃ）の仮定は補強ロールのネック強度が作業ロールよりも極めて大きいことからハウジング〜チョック間のギャップが十分小さく管理できている場合にはさほど無理のない仮定と考える。
【００２２】
上述の仮定に従って条件式を導くと下記式（１７）を得る。
Ｔ_ＷＷ＝Ｔ_ＷＢ ^Ｔ＋Ｔ_ＷＢ ^Ｂ＋Ｔ_Ｂ　　　　　　　　　　　　　　　　（１７）
ここで、Ｔ_Ｂは下補強ロールを基準とした上補強ロールの微小クロスに起因するスラスト力に相当する定数であり、予め与えなければならない。また、未知数が２個超過してしまう場合では、上述のような条件式の追加に加え、例えば、Ｔ_ＷＢ ^Ｔ＝Ｔ_ＷＢ ^Ｂのような仮定をおいて、未知数を一個減らすことが必要となる。
以上のように導出した式（１７）を、特許文献４記載のロール軸方向の力の平衡条件式およびモーメントの平衡条件式に、新たな方程式として加えることで未知数が超過してしまう条件でも解を求めることができる。
【００２３】
尚、式（１７）の定数Ｔ_Ｂは、例えば、以下のような方法で求めることができる。
Ｔ_Ｂは上述のように上下補強ロール間の相対的クロス角に起因するという物理的意味があるので作業ロール組替によって変動する可能性は少ない。そこで、１圧延単位の圧下設定実績を分析した上でＴ_Ｂを決め、その値を次の作業ロール組替後の圧下零調計算に生かすという学習的使用方法が考えられる。
また、圧延機の変形特性を求める場合は、上記のようして学習により求めたＴ_Ｂを補強ロールのセット毎にデータベース化しておき、キスロール締め込み状態で圧延機の変形特性を測定する際にその値を使用するようにすればよい。
【００２４】
以上では４段圧延機を例にとって説明してきたが、さらに中間ロールが増えた圧延機型式の場合、中間ロールが一本増える毎に、ロール間接触領域が一箇所増えので、増える未知数は追加された接触領域に作用するスラスト力と線荷重分布の左右差の２個になる。一方、利用可能な方程式も当該ロールのロール軸方向の力の平衡条件式とモーメント平衡条件式の２個が増えることになり、当該中間ロールのスラスト反力が測定可能であれば、他のロールに関する方程式と連立することにより、すべての解を求めることが可能となる。従って、本発明の請求項２の方法では、４段以上の圧延機の場合でも、少なくとも補強ロール以外のすべてのロールに作用するスラスト反力を測定するので、４段圧延機の場合と同様にロール間に作用する線荷重分布の左右差等の未知数を求めることが可能となる。また、本発明の請求項１の方法では、新たに追加された接触領域に作用するスラスト力を零とおくことによって、同様に未知数を求めることが可能であるが、補強ロール以外の何れかのロールに作用するスラスト反力を測定することが可能であれば、より解の精度を高めることができる。
また、本発明の請求項３の方法では、４段以上の圧延機の場合でも、上記で示したような仮定に従って、新たな条件式を導入することで、４段圧延機の場合と同様にロール間に作用する線荷重分布の左右差等の未知数を求めることが可能となる。
【００２５】
次に、上述のロールの力の平衡条件式およびモーメントの平衡条件式に基づく圧下零点調整方法および圧延機の変形特性の左右非対称性を抽出する方法を説明する。
図１は、本発明の請求項１の板圧延方法で、４段圧延機の圧下零点調整の好ましい実施形態のアルゴリズムを示す図である。圧下零点調整は、ロール組み替えの後に実施されるものであり、通常は補強ロール反力が所定の零調荷重になるまでキスロール締め込みを実施する（Ｆ１−１）。このとき左右の補強ロール反力が等しくなるように圧下レベリングも調整した上で圧下位置を仮に零にリセットする（Ｆ１−２）。この補強ロール反力としては、上または下補強ロールの反力を単独で用いてもよいし、例えば、上下補強ロール反力の平均値を用いてもよい。図１のアルゴリズムでは、その状態で、上下・左右の補強ロール反力を測定し（Ｆ１−３）、上述の式（１）〜（８）より、上下作業ロール間に作用するスラスト力Ｔ_ＷＷおよび各ロール線荷重分布の左右差ｐ^ｄｆ _ＷＢ ^Ｔ、ｐ^ｄｆ _ＷＢ ^Ｂ、ｐ^ｄｆ _ＷＷを演算する（Ｆ１−４）。この演算結果を用いて、圧下零調状態におけるロール変形量の左右差を計算し、この左右差を圧下支点位置に換算して圧下零点位置の補正量を演算する（Ｆ１−５）。ロール変形量の左右差は、主として各ロール間に作用する線荷重分布の左右非対称成分によって発生し、その主因はロール偏平変形量の左右差であり、これは既に求められたｐ^ｄｆ _ＷＢ ^Ｔ、ｐ^ｄｆ _ＷＢ ^Ｂ、ｐ^ｄｆ _ＷＷより直ちに計算することができる。この計算結果より求められるロール胴端位置における偏平変形量の合計の左右差を補強ロールの圧下支点位置にまで外挿することで、圧下零点位置の補正量が演算できる。この圧下零点位置の補正量に基づき、ロール変形量の左右非対称量分を解消する方向に圧下位置を移動した位置を真の零点とする。圧下位置零点をこのように設定することによって、実際の圧延時に発生する左右非対称負荷および変形を考慮して正確な圧下設定を実施することが可能となる（Ｆ１−６）。尚、同様の効果を得ることを目的とする場合、図１のように圧下零点を修正してしまうのではなくて、零調時のこのようなロール非対称変形量そのものを記憶しておき、実際の圧下設定時に常にその分を補正する方法でも対処することができる。
【００２６】
尚、本発明請求項２における４段圧延機の圧下零点調整の実施形態は、図１のアルゴリズムのフローのＦ１−３の内容を「キスロール締め込みの上下作業ロールスラスト反力および下補強ロール反力を測定」に、Ｆ１−４の内容を「補強ロールおよび作業ロールに作用するロール軸方向の力の平衡条件式とモーメントの平衡条件式（９）〜（１６）より上下作業ロール間および下作業ロール〜補強ロール間に作用するスラスト力および各ロール線荷重分布の左右差を演算」に置き換えることで同様に実施することができる。
【００２７】
また、本発明請求項３における４段圧延機の圧下零点調整の実施形態は、図１のアルゴリズムのフローのＦ１−３の内容を「キスロール締め込みの上下・左右補強ロール反力を測定および定数Ｔ_Ｂを読込」または「キスロール締め込みの上下作業ロールスラスト反力、下補強ロール反力を測定および定数Ｔ_Ｂを読込」、Ｆ１−４の内容を「特開平１０−２６３６５６号記載の補強ロールおよび作業ロールに作用するロール軸方向の力の平衡条件式、モーメントの平衡条件式および条件式（１７）より上下作業ロール間および下作業ロール〜補強ロール間に作用するスラスト力および各ロール線荷重分布の左右差を演算」に置き換えることで同様に実施することができる。
【００２８】
図２は、本発明の請求項１の板圧延方法で、４段圧延機の変形特性を求める際のデータ採取手続きおよび変形特性を演算抽出するアルゴリズムを示している。ここで言う変形特性とは、いわゆるミルストレッチであり、圧延荷重が負荷された際、圧延機の弾性変形の結果として生ずる上下作業ロール間のギャップの変化を意味する。このミルストレッチの把握の際、ロール系の変形については、既存の方法で高精度に求めることができるが、ロール系以外のハウジング・圧下系の変形特性は多くの弾性接触面を含むため理論的に正確に把握することは一般に困難である。そこで、特公平４−７４０８４号公報では、圧延作業前に予めキスロール締め込みテストを実施して、そのときの各締め込み荷重に対する変形量からロール系の変形量を計算して分離し、ハウジング・圧下系の変形特性を分離する方法が開示されており、特開平６−１８２４１８号公報では、左右のハウジング・圧下系の変形特性を独立して分離する方法が開示されている。ところが、特開平６−１８２４１８号公報の方法では、ロール間に作用するスラスト力の影響が一切考慮されていないので、ロール間スラスト力がある程度以上の値になった場合には十分な精度が得られない問題があった。
【００２９】
本発明請求項１は、この問題も解決できる技術であり、キスロール締め込みテストを実施する際に、上下・左右の補強ロール反力を測定する。以下、図２を参照しながらデータ採取手続きを説明する。先ず、キスロール締め込み状態で所定の圧下位置まで締め込む（Ｆ２−１）。この時、圧下位置の左右差すなわち圧下レベリングは固定したまま、左右の圧下位置を同じ方向に同じ量だけ変化させる運転モードで操作する。同時圧下モードで運転する限り圧下レベリングが変化することはない。この時の各圧下位置の実績値と上下・左右補強ロール反力を測定する（Ｆ２−２、Ｆ２−３）。次に、左右同時圧下モードで圧下装置を一定量だけ締め込み、上記の測定を行い、所定の圧下位置水準のデータ採取が完了するまで繰り返す。つまり、Ｆ２−４においてデータ採取完了か否かを判断し、Ｎｏの場合、圧下位置を変更（Ｆ２−５）し、Ｙｅｓの場合は次のステップ（Ｆ２−６）に進む。この圧下位置水準の数は多い方がよいが、通常の圧延機では１０〜２０点程度のデータを採取できれば実用的な精度は得られる。ただし、この時、圧下装置を締め込む方向と開放する方向とで締め込み荷重に差異を生じる、いわゆるミルヒステリシスを生ずることが多いので、このような場合には、締め込み方向と開放方向の少なくとも１往復動作に対するデータを採取し、例えば、両者の測定データを平均化する等の操作を行うことが好ましい。
【００３０】
次に、上記の手続きにしたがって採取したデータを用いて、ハウジング・圧下系の変形特性を左右独立に演算抽出するアルゴリズムを説明する。まず、各圧下位置条件に対する上下・左右補強ロール反力の測定値を抽出する（Ｆ２−６）。次に、上記した圧下零点調整の場合と全く同様にして、補強ロールおよび作業ロールに作用するロール軸方向の力の補強ロールおよび作業ロールに作用するロール軸方向の力の平衡条件式とモーメントの平衡条件式（１）〜（８）より上下作業ロール間に作用するスラスト力および各ロール線荷重分布の左右差を演算する（Ｆ２−７）。これらロール間の荷重分布が求められれば、特公平４−７４０８４号公報に開示されている方法等によって、補強ロールおよび作業ロールのたわみ変形および偏平変形を左右差を含めて計算することができ、これらの変形の結果として補強ロールの圧下支点位置に生じる変位を計算することができる（Ｆ２−８）。最後にミル全体の変形量は圧下位置変化で評価されているので、これより上記圧下支点位置におけるロール系の変形量を差し引き、ハウジング・圧下系の変形特性を左右独立に演算する（Ｆ２−９）。このようにロール間スラスト力の正確な同定に基づくロール変形計算を実施することで、ハウジング・圧下系の変形特性を、その左右差を含めて正確に把握することが可能になる。
【００３１】
尚、本発明請求項２における４段圧延機の変形特性算出の実施形態は、図２のアルゴリズムのフローのＦ２−３の内容を「各圧下位置の上下作業ロールスラスト反力および下補強ロール反力を測定」に、Ｆ２−６の内容を「キスロール締め込みの各圧下位置条件に対する上下作業ロールスラスト反力および下補強ロール反力測定値を抽出」に、Ｆ２−７の内容を「補強ロールおよび作業ロールに作用するロール軸方向の力の平衡条件式とモーメントの平衡条件式（９）〜（１６）より上下作業ロール間および下作業ロール〜補強ロール間に作用するスラスト力および各ロール線荷重分布の左右差を演算」に、置き換えることで同様に実施することができる。
【００３２】
また、本発明請求項３における４段圧延機の変形特性算出の実施形態は、図２のアルゴリズムのフローのＦ２−３の内容を「各圧下位置の上下・左右補強ロール反力および定数Ｔ_Ｂを読込」または「各圧下位置の上下作業ロールスラスト反力、下補強ロール反力を測定および定数Ｔ_Ｂを読込」に、Ｆ２−６の内容はそのままか、または「キスロール締め込みの各圧下位置条件に対する上下作業ロールスラスト反力および下補強ロール反力測定値を抽出」に、Ｆ２−７の内容を「特開平１０−２６３６５６号記載の補強ロールおよび作業ロールに作用するロール軸方向の力の平衡条件式、モーメントの平衡条件式および条件式（１７）より上下作業ロール間および下作業ロール〜補強ロール間に作用するスラスト力および各ロール線荷重分布の左右差を演算」に、置き換えることで同様に実施することができる。
【００３３】
図３は、本発明の請求項１、２または３の圧延機の圧延方法であって、上述の方法で同定した圧延機ハウジング・圧下系の変形特性を用いて最適な圧下レベリングを設定する方法の例を示している。
先ず、これから圧延しようとする圧延材の板幅、入側板厚、目標とする出側板厚、圧延速度、熱間圧延の場合には圧延温度を含む変形抵抗特性値等の圧延条件を入力する（Ｆ３−１）。次いで、入力された圧延条件と、作業ロール直径、作業ロールの弾性定数等の圧延機側の条件を考慮して圧延荷重を予測計算する（Ｆ３−２）。次に、上記圧延荷重の計算値、圧延速度から、上述の実施形態による方法で同定した左右の圧延機ハウジング・圧下系の変形特性に基づき、ロール系以外の板圧延機の変形量を作業側および駆動側個別に演算する（Ｆ３−３）。さらに上記圧延荷重にからロール系の変形量を計算して、この変化量と上記ロール系以外の板圧延機の変形量から、作業側端部と駆動側端部におけるロールギャップ変化を計算する（Ｆ３−４）。最後に、上記ロールギャップ変化の計算値と、板厚の左右差すなわち板厚ウェッジの目標値とから、圧下レベリング設定値を計算し、これに基づいて圧下レベリング設定を実行する（Ｆ３−５）。ここで、目標とする板厚ウェッジは、通常は左右対称な板厚分布すなわち板厚ウェッジ零であるが、入側板厚に無視できない板厚ウェッジが存在し、これを１パスの圧延で矯正した場合、蛇行やキャンバーあるいは平坦度不良が発生すると判断された場合は、零以外の板厚ウェッジ目標を設定することも好ましい。また、上述の圧下レベリング設定を実施する際、圧下零点調整時に記憶しておいたロール非対称変形量分を同時に補正することでより高精度な圧下レベリング設定を実現することができる。
【００３４】
また、圧延実行中に動的な圧下レベリング制御を実施する場合は、例えば、昭和５５年度塑性加工春季講演会（１９８０）ｐｐ．６１〜６４に発表されている論文「ホットストリップ圧延における蛇行制御方法の研究（第１報）」（中島、菊間、松本、梶原、木村、田川著）において定義されている第１種平行剛性と第２種平行剛性を用いて、圧延実行中の圧延荷重変動の左右測定値等の測定データより、圧延材の板厚ウェッジの変動を予測し、これを所望の値にするための圧下レベリング制御量を左右の圧延機ハウジング・圧下系の変形特性に基づき演算し制御を実施する。このような制御を実行することにより、圧延中に発生する変動要因によって発生する蛇行や板厚ウェッジを実用上問題のないレベルに抑えることが可能となる。
【００３５】
図４には、本発明請求項１または請求項３の板圧延方法を実施するための板圧延機の構成で、上下・左右に補強ロール反力測定用ロードセルを有する４段圧延機の好ましい実施形態を示す。図４において、圧延機１は、ハウジング２に作業ロールチョック５ａ、５ｂ、５ｃ、５ｄおよび補強ロールチョック６ａ、６ｂ、６ｃ、６ｄを介して回転自在に支持された作業ロール３ａ、３ｂと、補強ロール４ａ、４ｂを具備して成り、４段圧延機を構成している。ハウジング２には左右一対、つまり作業側と駆動側の圧下装置９ａ、９ｂが設けられており、上下の作業ロール３ａ、３ｂの間隙を制御する。上下補強ロールの左右の圧下支点位置には、補強ロール反力測定用ロードセル７ａ、７ｂ、７ｃ、７ｄが配備されている。このような構成の４段圧延機を用いることにより、上下・左右の補強ロール反力を測定することが可能となり、本発明請求項１の板圧延方法が実施できる。尚、図４には、インクリース作業ロールベンディング装置１０ａ、１０ｂ、ディクリース作業ロールベンディング装置１１ａ、１１ｂ、補強ロールバランス装置１２ａ、１２ｂ、パスライン高さ調整用ライナー１３ａ、１３ｂを表示しているが、本発明の板圧延機では、必須要件でない。
【００３６】
また、上下補強ロールの各圧下支点位置に作用する補強ロール反力は、通常ロードセルによって測定するが、例えば、油圧圧下装置を有する圧延機の場合、圧下シリンダー内または圧下シリンダーに直結する配管内の油圧の測定値から計算する方法でもよい。ただし、この場合、油圧圧下が急速に圧下位置を変更している状態では、測定値に大きな誤差を生ずるので、圧力データを採取する時は一時的に圧下位置を保定する等の措置を講ずる必要がある。
【００３７】
図５には、本発明請求項２または請求項３の板圧延方法を実施するための板圧延機の構成で、上下作業ロールスラスト反力の測定装置と下補強ロール反力の測定装置を有する４段圧延機の好ましい実施形態を示す。図４において、圧延機１は、ハウジング２に作業ロールチョック５ａ、５ｂ、５ｃ、５ｄおよび補強ロールチョック６ａ、６ｂ、６ｃ、６ｄを介して回転自在に支持された作業ロール３ａ、３ｂと、補強ロール４ａ、４ｂを具備して成り、４段圧延機を構成している。ハウジング２には左右一対、つまり作業側と駆動側の圧下装置９ａ、９ｂが設けられており、上下の作業ロール３ａ、３ｂの間隙を制御する。上下補強ロールの左右の圧下支点位置には、補強ロール反力測定用ロードセル７ｂ、７ｄ、が配備されている。また作業ロール３ａ、３ｂは、作業ロールに作用するスラスト反力を測定するためのロードセル８ａ、８ｂが配備されている。このような構成の４段圧延機を用いることにより、上下どちらか一方の補強ロール反力、すなわち、図５の例では下の左右の補強ロール反力と、補強ロール以外のすべてのロール、すなわち、図５の例の場合は、上下作業ロールに作用するスラスト反力を測定することが可能となり、本発明請求項２の板圧延方法が実施できる。尚、図５には、インクリース作業ロールベンディング装置１０ａ、１０ｂ、ディクリース作業ロールベンディング装置１１ａ、１１ｂ、補強ロールバランス装置１２ａ、１２ｂ、パスライン高さ調整用ライナー１３ａ、１３ｂを表示しているが、本発明の板圧延機では、必須要件ではない。
【００３８】
図５は、ロードセル８ａ、８ｂによって作業ロールのスラスト反力を測定する例であるが、作業ロールシフト装置のアクチュエータが油圧シリンダーの場合は、ロードセル８ａ、８ｂの代わりに油圧シリンダー内あるいは油圧シリンダーに直結する油圧配管の圧力を測定する圧力測定装置で作業ロールスラスト反力測定装置を代用してもよい。また、作業ロールシフト装置を有しない場合は、作業ロールのロールチョック内に配備されたスラスト反力測定装置や作業ロールチョックをロール軸方向に拘束するキーパプレートに作用する荷重を測定する装置等を採用すればよい。
【００３９】
以上述べてきたように、発明では、補強ロール以外のロールに作用するスラスト反力と、上下双方の補強ロールの各圧下支点位置に作用する補強ロール反力の測定装置がすべて備わっていない圧延機においても、圧下装置の零点と圧延機の変形特性を再現性良く求め、その結果を活用した板圧延機の圧下位置設定および制御を実施することよって、圧延操業における蛇行や通板トラブルの発生頻度を大幅に低減し、さらに圧延材のキャンバーや板厚ウェッジも大幅に低減が可能になる。
【００４０】
【実施例】
図６に示すような７台の４段圧延機２４ａ〜２４ｇを有する熱間仕上圧延機に本発明の板圧延方法を適用した場合の実施例について説明する。
図６において、２０は圧延材、２１は圧延材の移動方向を示し、２２は演算処理装置、２３は圧下位置制御装置である。４段圧延機２４ａ〜２４ｇの全ての圧延機には、左右独立に検出可能な下補強ロール反力測定用ロードセル２５ａ〜２５ｇ、左右独立に操作可能な電動圧下装置２６ａ〜２６ｇが装備され（図６では左右の一方を図示）、第１〜第３スタンドの４段圧延機２４ａ〜２４ｃには、左右独立に検出可能な上補強ロール反力測定用ロードセル２７ａ〜２７ｃが装備されている（図６では左右の一方を図示）。第４、６、７スタンドの４段圧延機２４ｄ、２４ｆ、２４ｇには、上下作業ロールのロール軸方向に作用するスラスト反力の測定が可能な上スラスト反力測定用ロードセル２８ｄ、２８ｆ、２８ｇと下スラスト反力測定用ロードセル２９ｄ、２９ｆ、２９ｇが装備されている（図６では左右の一方を図示）。また、第５、６、７スタンドの上部には左右に油圧圧下装置３０ｅ〜３０ｇ、油圧シリンダー圧力測定装置３１ｅ〜３１ｇが装備されている（図６では左右の一方を図示）。この油圧圧下装置３０ｅ〜３０ｇには、一時的に圧下位置を保定する機能も備わっており、油圧シリンダー圧力測定装置３１ｅ〜３１ｇの油圧を測定することで、左右の上補強ロール反力を求めることが可能となっている。
【００４１】
演算処理装置２２では、各スタンドに備わっているセンサ、すなわち、下補強ロール反力測定用ロードセル２５ａ〜２５ｇ、上補強ロール反力測定用ロードセル２７ａ〜２７ｃ、上作業ロールスラスト反力測定用ロードセル２８ｄ、２８ｆ、２８ｇ、下作業ロールスラスト反力測定用ロードセル２９ｄ、２９ｆ、２９ｇ、油圧シリンダー圧力測定装置３１ｅ〜３１ｇの各測定値が読み込まれ、これらの測定値に基づき、各スタンドの左右の圧下位置設定値および／または制御値が演算され、これらが圧下位置制御装置２３に送られる。圧下位置制御装置２３では、前記の圧下位置設定値および／または制御値に基づき、各スタンドの電動圧下装置２６ａ〜２６ｇを左右独立に操作し、圧下レベリング設定・制御の実施が可能な構成となっている。
【００４２】
尚、図６において、第１〜第３、第５スタンドの圧延機では、上下・左右の補強ロール反力を測定することが可能であるので、本発明請求項１または請求項３の板圧延方法が実施できる。また、第４スタンドの圧延機では、下の左右の補強ロール反力および上下作業ロールに作用するスラスト反力を測定することが可能であるので、本発明請求項２または請求項３の板圧延方法が実施できる。
【００４３】
このような構成の圧延機を使用して、圧下装置の零点と圧延機の変形特性に基づく圧延実行時の圧下位置設定・制御に関して、従来方法と本発明の方法との比較を行った。尚、第６〜第７スタンドについては、上下作業ロールのスラスト反力と上下の補強ロール反力の測定が可能であるので、特許文献４に開示されている方法をそのまま適用し、第１〜第５スタンドについて、従来方法と本発明の方法との比較を行った。
【００４４】
先ず、従来方法では、特許文献４に開示されている方法が、第１〜第５スタンドで測定装置が不足となるため適用できないので、圧下位置零点の調整は、下の左右の補強ロール反力が等しくなるように調整した上で、特許文献３に開示されている方法で同定した圧延機ハウジングおよび圧下系の変形特性に基づき、圧延実行前の圧下レベリング設定および圧延実行中の圧下レベリング制御を実施した。その結果、出側板厚１．２ｍｍ、幅１２００ｍｍの薄物広幅材の圧延した場合、板厚ウェッジ、キャンバーが発生すると共に、第５スタンドにおいて蛇行による絞り込みが発生した。
【００４５】
一方、本発明の方法では、第１〜第３、第５スタンドに本発明請求項１の板圧延方法を、第４スタンドに本発明請求項２の板圧延方法を適用し、圧下装置の零点と圧延機の変形特性に基づく圧延実行前の圧下レベリング設定および圧延実行中の圧下レベリング制御を実施した。その結果、従来法で絞り込みが生じた出側板厚１．２ｍｍ、幅１２００ｍｍの薄物広幅材を圧延した場合でも、板厚ウェッジ、キャンバーの発生も少なく、圧延材を圧延ラインに真直に通板させることができた。
【００４６】
以上のように、本発明の方法では、補強ロール以外のロールに作用するスラスト反力と、上下双方の補強ロールの各圧下支点位置に作用する補強ロール反力の測定装置がすべて備わっていない圧延機においても、圧下装置の零点と圧延機の変形特性を再現性良く求め、その結果を活用した板圧延機の圧下位置設定・制御を実施するので、圧延材頭部の圧延開始時点から板厚ウェッジやキャンバーを発生させない安定な圧延操業を実現できることが証明された。
【００４７】
【発明の効果】
本発明によって、従来オペレータに頼っていた圧延機の圧下レベリング設定・制御が自動化できることになる上、従来以上に正確かつ適切な圧下レベリング設定・制御が可能になるので、圧延操業における蛇行や通板トラブルの発生頻度を大幅に低減し、さらに圧延材のキャンバーや板厚ウェッジも大幅に低減することが可能になるので、圧延に要するコスト削減と品質向上を同時に達成することが可能になる。
【図面の簡単な説明】
【図１】本発明請求項１の板圧延方法で、４段圧延機の場合の圧下零点調整方法の好ましい実施形態のアルゴリズムを示す図。
【図２】本発明請求項１の板圧延方法で、４段圧延機の場合の変形特性同定のための実機データ測定の手続きおよび変形特性演算の好ましい実施形態のアルゴリズムを示す図。
【図３】本発明請求項１、請求項２または請求項３の板圧延方法で、４段圧延機の場合の圧下位置設定方法の好ましい実施形態のアルゴリズムを示す図。
【図４】本発明請求項１または請求項３の板圧延方法を実施するための板圧延機の構成で、上下・左右に補強ロール反力測定用ロードセルを有する４段圧延機の場合の好ましい実施形態を示す図。
【図５】本発明請求項２または請求項３の板圧延方法を実施するための板圧延機の構成で、上下作業ロールスラスト反力の測定装置と下補強ロール反力の測定装置を有する４段圧延機の場合の好ましい実施形態を示す図。
【図６】７台の４段圧延機を有する熱間仕上圧延機で、本発明の板圧延方法を適用した場合の実施例を示す図。
【図７】４段圧延機の各ロールに作用するロール軸方向の力と鉛直方向の力の左右非対称成分を示す模式図。
【符号の説明】
１…４段圧延機　　　　　　　　　　　２…ハウジング
３ａ、３ｂ…作業ロール　　　　　　　４ａ、４ｂ…補強ロール
５ａ、５ｂ、５ｃ、５ｄ…作業ロールチョック
６ａ、６ｂ、６ｃ、６ｄ…補強ロールチョック
７ａ、７ｂ、７ｃ、７ｄ…補強ロール反力測定用ロードセル
８ａ、８ｂ…スラスト反力測定用ロードセル
９ａ、９ｂ…圧下装置
１０ａ、１０ｂ…インクリース作業ロールベンディング装置
１１ａ、１１ｂ…ディクリース作業ロールベンディング装置
１２ａ、１２ｂ…補強ロールバランス装置
１３ａ、１３ｂ…パスライン高さ調整用ライナー
１４ａ、１４ｂ…キーパプレート
１５ａ、１５ｂ、１５ｃ、１５ｄ…補強ロール反力測定用ロードセルの出力
１６…上作業ロール〜上補強ロール間線荷重分布
１７…上下作業ロール間線荷重分布
１８…下作業ロール〜下補強ロール間線荷重分布
２０…圧延材　　　　　　　　　　　　２１…圧延材の移動方向
２２…演算処理装置　　　　　　　　　２３…圧下位置制御装置
２４ａ〜２４ｇ…４段圧延機
２５ａ〜２５ｇ…下補強ロール反力測定用ロードセル
２６ａ〜２６ｇ…電動圧下装置
２７ａ〜２７ｃ…上補強ロール反力測定用ロードセル
２８ｄ、２８ｆ、２８ｇ…上作業ロールスラスト反力測定用ロードセル
２９ｄ、２９ｆ、２９ｇ…下作業ロールスラスト反力測定用ロードセル
３０ｅ〜３０ｇ…油圧圧下装置
３１ｅ〜３１ｇ…油圧シリンダー圧力測定装置[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a rolling method for rolling a metal plate such as a steel plate.
[0002]
[Prior art]
One of the important issues in the rolling operation of a metal sheet material is to make the elongation rate of the rolled material equal between the working side and the driving side. In the following description, the working side and the driving side will be referred to as left and right for simplicity of notation. When the difference in elongation becomes uneven in the right and left directions, not only the planar shape and dimensional accuracy of a rolled material such as a camber and a thickness wedge are deteriorated, but also a passing trouble such as meandering and squeezing may occur.
As an operating means for equalizing the right and left elongation percentages, a left / right difference in a rolling position of a rolling mill is eliminated, that is, a rolling leveling operation is used. Normally, the operation of rolling leveling, setting before rolling, the operation during rolling, in most cases, the operator is operating while carefully observing the rolling operation, but poor quality of the camber and plate thickness wedge described above, It cannot be said that the threading trouble is sufficiently controlled.
[0003]
To solve the above problem, Patent Literature 1 discloses a technique of performing a rolling leveling control based on a ratio of a load cell load of a rolling mill to a sum of right and left differences. Further, Patent Document 2 discloses a technique for operating a rolling leveling by directly detecting a shift of a rolled material on the entry side of a rolling mill, that is, a meandering amount.
Any of the techniques for reducing the left-right difference in the elongation rate of the rolled material exemplified here aims at optimizing the reduction leveling as the control means. This is a feedback-type control technique that causes an action after a difference between the left and right is detected, and this is detected as meandering or a camber of the rolled material. In the case of this type of control, there is a significant time delay between the occurrence of a difference in the elongation rate of the rolled material and the detection of this as a meander or camber. And the problem of camber has not yet been completely solved.
[0004]
Patent Literature 3 and Patent Literature 4 are disclosed as technologies that may solve the problems of the above technology. Unlike the above-mentioned feedback method, these technologies accurately grasp the left-right asymmetry of the deformation characteristics of the rolling mill, and also accurately determine the left-right asymmetry of the deformation characteristics such as the dimensions of the rolled material and deformation resistance. The aim was to realize an operation that does not generate meandering or camber from the start of rolling of the head of the rolled material by optimally setting the rolling reduction value before starting rolling.
[0005]
[Patent Document 1]
JP-B-58-51771
[Patent Document 2]
JP-A-59-191510
[Patent Document 3]
Japanese Patent Publication No. 2604528
[Patent Document 4]
JP-A-10-263656
[0006]
[Problems to be solved by the invention]
In the above-mentioned Patent Document 3, in order to identify the left-right asymmetry of the deformation characteristics of the rolling mill, in particular, the rolling device is operated to perform kiss roll tightening, and the load cell on the working side and the drive side and the load cell for measuring the rolling load. Is measured for a plurality of rolling position conditions, the deformation of the roll system corresponding to each rolling position condition is calculated and separated, and the resulting asymmetry of the deformation characteristics of the rolling mill housing and the rolling system is determined. A technique has been disclosed in which the properties of the rolling mill are identified and the optimum rolling leveling is set by utilizing the deformation characteristics of the rolling mill obtained in this manner. Here, the kiss roll tightening means that the upper and lower work rolls are brought into contact with each other in a state where the rolled material does not exist, and a load is applied between the rolls.
[0007]
Further, in Patent Document 4, when adjusting the rolling zero point by tightening the kiss roll and extracting the left-right asymmetry of the deformation characteristics of the rolling mill, the thrust reaction force acting on the rolls other than the reinforcing rolls, and the reduction of each of the upper and lower reinforcing rolls Measure the reinforcing roll reaction force acting on the fulcrum position, and based on the zero point of the rolling device obtained by separating the disturbance due to the thrust force between the rolls and the deformation characteristics of the rolling mill, provide a means for performing optimal rolling leveling setting and control. Has been disclosed. Here, the thrust reaction force is to maintain the rolls in a fixed position against the resultant force of the thrust forces generated by the presence of a small cross angle between the rolls mainly on the contact surface of each roll body, with respect to each roll. Reaction force.
[0008]
However, when the technology disclosed in Patent Document 3 is implemented, depending on the rolling mill, sufficient reproducibility may not be seen in the deformation characteristics of the identified rolling mill housing and the rolling system. Cannot be optimized, and as a result, meandering and camber cannot be sufficiently prevented. As a technique capable of solving this problem, there is a technique disclosed in Patent Literature 4 described above. However, a thrust reaction force acting on a roll other than the reinforcing roll and a reinforcement acting on each lowering fulcrum position of both upper and lower reinforcing rolls are disclosed. Since the measurement of the roll reaction force is indispensable, there is a problem that it cannot be applied to a rolling mill that does not have a measuring device capable of measuring all of these values.
[0009]
Therefore, in the present invention, even in a rolling mill that does not have all the measuring devices for the thrust reaction force acting on the rolls other than the reinforcement rolls and the reinforcement roll reaction force acting on each reduction fulcrum position of the upper and lower reinforcement rolls, Provided is a sheet rolling method capable of obtaining a zero point of a device and a deformation characteristic of a rolling mill with good reproducibility, and effectively performing setting of a rolling position and / or controlling of a rolling position of a sheet rolling machine using the results. The purpose is to do.
[0010]
[Means for Solving the Problems]
The gist of the present invention for achieving the above object is as follows.
(1) In a rolling method using a multi-stage plate rolling mill of four or more stages, in a kiss roll tightened state, a rolling reduction device is obtained from only measured values of a reinforcing roll reaction force acting in a rolling direction at respective rolling fulcrum positions of upper and lower reinforcing rolls. A sheet rolling method characterized in that one or both of the zero point of the rolling mill and the deformation characteristics of the rolling mill are determined, and the rolling position is set and / or controlled during rolling based on the determined zero point and / or the rolling characteristic.
(2) Measurement of thrust reaction force acting in the roll axis direction of all of the work rolls, work rolls and intermediate rolls in a kiss roll tightened state by a rolling method using a multi-stage plate rolling machine having four or more stages. From only the measured value of the reinforcing roll reaction force acting in the rolling direction at each rolling fulcrum position of one of the upper and lower reinforcing rolls, determine one or both of the zero point of the rolling device and the deformation characteristics of the rolling mill, A sheet rolling method, wherein a rolling position is set and / or controlled at the time of rolling, based on this.
(3) The sheet rolling according to (1) or (2), wherein a constant determined in advance is used when obtaining one or both of the zero point of the rolling device and the deformation characteristic of the rolling mill. Method.
[0011]
In the left-right difference of the rolling load measured by the load cell of the rolling mill, in addition to the left-right asymmetry of the rolling load distribution between the rolled material and the work roll, for example, in the case of a four-high rolling mill, between the work roll and the reinforcing roll, In the case of a six-high rolling mill, a thrust force acting in the roll axis direction between the work roll and the intermediate roll and between the intermediate roll and the reinforcing roll is included as the largest factor. The thrust force acting between these rolls gives an extra moment to the rolls, and the difference between the left and right rolling loads changes to balance this moment. -It is a serious disturbance for the purpose of grasping the left-right asymmetry of the rolling load distribution generated between the work rolls.
The main cause of the above-mentioned thrust force between the rolls is that, when they come into contact with each other, the rotation axes of the adjacent rolls are shifted from the parallel position by a small gap between the roll chocks and the housing window. If an error occurs in the parallelism between the adjacent roll axes as described above, a deviation component in the roll axis direction occurs in the roll peripheral speed vectors of the two rolls due to the roll rotation. As a result, slippage always occurs in the roll axis direction. The force generated by such slip is the inter-roll thrust force, and the force that continuously generates slip is the thrust reaction force acting from a keeper plate or the like that fixes the roll chocks in the axial direction.
[0012]
As described above, the thrust force between rolls is generated by a slight parallelism error between adjacent roll shafts, so the direction and size are generally unknown. It is an unstable thing that may do. Therefore, in the rolling zero adjustment, the rolling position is reset so that the load measured by the load cells on the working side and the driving side becomes equal to the predetermined load, and the zero point of the rolling leveling is also reset at the same time. If the right-left difference of the load cell load includes disturbance due to such a thrust force between the rolls, accurate zero adjustment of the reduction level cannot be executed, and the error of the zero point is always set in the subsequent reduction level setting. Will be included. Also, when the deformation characteristics of the rolling mill are grasped from the kiss roll tightening data, the deformation characteristics of the rolling mill housing and the rolling system are taken as the basic data based on the work side and the drive side rolling position and the measured load cell load value for the rolling load. Since the lateral asymmetry of the rolling mill is identified, it is understood that, when disturbance is mixed in the load cell load due to the thrust force between the rolls as described above, this becomes a large error factor to the identification result of the lateral asymmetry of the deformation characteristics of the rolling mill.
[0013]
With respect to such a disturbance of the thrust force, the method of Patent Document 4 described above measures the thrust reaction force acting on rolls other than the reinforcement roll and the reinforcement roll reaction force acting on each of the pressing fulcrum positions of the upper and lower reinforcement rolls. Also disclosed is a method of separating disturbance due to a thrust force between rolls. However, in this method, it is necessary to measure the thrust reaction force acting on the rolls other than the reinforcement roll and the reinforcement roll reaction force acting on the respective lower fulcrum positions of the upper and lower reinforcement rolls as described above. Cannot be applied to a rolling mill that does not have a measuring device capable of measuring the value of. For example, equipping all the rolling mills with the above-described measuring device in equipment usually having seven stands, such as a hot finishing rolling mill, imposes a heavy burden in terms of equipment costs. It is often difficult to do.
[0014]
Therefore, the present inventors, in the case of a rolling mill that is not equipped with a thrust reaction force acting on rolls other than the reinforcing roll and both upper and lower reinforcing roll reaction forces, the reduction of the zero point when tightening the kiss roll. And various methods for extracting the left-right asymmetry of the deformation characteristics of the rolling mill, and by making certain approximations and assumptions in the equation system for calculating the inter-roll thrust force, sufficient accuracy for practical use is obtained. Was obtained.
[0015]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In the following, for the sake of simplicity, all four-high rolling mills will be described as an example. However, the present invention can of course be similarly applied to five- or six-high rolling mills of the type to which an intermediate roll is added. is there.
[0016]
First, in the plate rolling method according to claim 1 of the present invention, each roll required when calculating the difference between the right and left deformation amounts of each roll from the measured values of the upper and lower and right and left reinforcing roll reaction forces when tightening the kiss roll. A method for calculating the left-right difference between the thrust force acting between them and the linear load distribution will be described. As disclosed in Patent Literature 4, an equation that can be used in the kiss roll tightened state is a sum of four balance equations for the force in the roll axis direction of each roll and four balance equations for the moment of each roll. There are eight. FIG. 7 schematically shows the force acting on each roll in the roll axis direction and the force related to the moment of each roll. In this case, the following two of the force components shown in FIG. 7 can use the measured values.
P_df ^T: Reinforcement roll reaction force left / right difference at the upper support roll pressing down fulcrum position
P_df ^B: Reinforcement roll reaction force left / right difference at lower reinforcement roll pressing fulcrum position
The unknowns are the following 10 variables.
T_W ^T： Thrust reaction force acting on the upper work roll
T_W ^B： Thrust reaction force acting on the lower work roll
T_B ^T： Thrust reaction force acting on the upper reinforcement roll chock
T_WB ^T： Thrust force acting between upper work roll and reinforcing roll
T_WW: Thrust force acting between upper and lower work rolls
T_WB ^B： Thrust force acting between lower work roll and reinforcing roll
T_B ^B： Thrust reaction force acting on lower reinforcement roll chock
p^df _WB ^T： Right and left difference of linear load distribution between upper work roll and reinforcing roll
p^df _WB ^B： Right and left difference of linear load distribution between lower work roll and reinforcement roll
p^df _WW: Difference between left and right of linear load distribution between upper and lower work rolls
[0017]
In the case of claim 1 of the present invention, the load cell for measuring the reaction force of the upper and lower reinforcing rolls is disposed, but since there is no device for measuring the thrust reaction force of the work roll, the thrust reaction force T acting on the upper and lower work rolls._W ^T, T_W ^BBecomes impossible to measure, the number of unknowns exceeds two, and the equation cannot be solved. Therefore, in claim 1 of the present invention, the upper and lower thrust forces T acting between the work roll and the reinforcing roll_WB ^T, T_WB ^BIs assumed to be zero and the equation is solved. In this case, the equilibrium condition formula for the force and the equilibrium condition formula for the moment in the roll axis direction of each roll disclosed in Patent Document 4 are as follows. That is, the equilibrium conditional expressions of the forces in the roll axis direction of the upper reinforcing roll, the upper working roll, the lower working roll, and the lower reinforcing roll are as follows.
T_B ^T= 0 (1)
-T_WW= T_W ^T(2)
T_WW= T_W ^B(3)
T_B ^B= 0 (4)
[0018]
The equilibrium condition of the moment of the upper reinforcing roll, the upper working roll, the lower working roll, and the lower reinforcing roll is given by the following equation.
p^df _WB ^T(L_WB ^T)²/ 12 = P_df ^T・ A_B ^T/ 2 @ (5)
T_WW・ D_W ^T/ 2-p^df _WB ^T(L_WB ^T)²/ 12 + p^df _WW(L_WW)²/ 12 = 0 (6)
T_WW・ D_W ^B/ 2 + p^df _WB ^B(L_WB ^B)²/ 12-p^df _WW(L_WW)²/ 12 = 0 (7)
-P^df _WB ^B(L_WB ^B)²/ 12 = -P_df ^B・ A_B ^B/ 2 @ (8)
Where D_B ^T, D_B ^B, D_W ^T, D_W ^BAre the upper and lower reinforcing roll diameter, the upper and lower working roll diameter, respectively,_WB ^T, L_WW, L_WB ^BAre the lengths in the roll axis direction of the upper reinforcement roll to the upper work roll contact area, the upper and lower work roll contact areas, and the lower reinforcement roll to the lower work roll contact area, respectively. By solving the above equations (1) to (8) simultaneously, the above unknowns are calculated.
[0019]
Next, in the plate rolling method according to the second aspect of the present invention, the measured value of the thrust reaction force acting in the axial direction of the upper and lower work rolls when the kiss roll is tightened, and acts on the lowering roll at the position of each reduction fulcrum of the lower reinforcing roll. A method for calculating the left-right difference between the thrust force acting between the rolls and the linear load distribution required when calculating the left-right difference in the deformation amount of each roll from the measured value of the reinforcing roll reaction force will be described. Here, an example in which the lower reinforcing roll reaction force is measured is shown, but it goes without saying that the same can be applied to the case where the upper reinforcing roll reaction force is measured. In this case, the following three of the force components shown in FIG. 7 can use the measured values.
P_df ^B: Reinforcement roll reaction force left / right difference at lower reinforcement roll pressing fulcrum position
T_W ^T： Thrust reaction force acting on the upper work roll
T_W ^B： Thrust reaction force acting on the lower work roll
The unknowns are the following nine variables.
P_df ^T: Reinforcement roll reaction force left / right difference at the upper support roll pressing down fulcrum position
T_B ^T： Thrust reaction force acting on the upper reinforcement roll chock
T_WB ^T： Thrust force acting between upper work roll and reinforcing roll
T_WW: Thrust force acting between upper and lower work rolls
T_WB ^B： Thrust force acting between lower work roll and reinforcing roll
T_B ^B： Thrust reaction force acting on lower reinforcement roll chock
p^df _WB ^T： Right and left difference of linear load distribution between upper work roll and reinforcing roll
p^df _WB ^B： Right and left difference of linear load distribution between lower work roll and reinforcement roll
p^df _WW: Difference between left and right of linear load distribution between upper and lower work rolls
[0020]
In the case of claim 2 of the present invention, the thrust reaction force measuring device for the upper and lower work rolls and the load cell for measuring the lower reinforcement roll reaction force are arranged based on the measured values of the vertical and horizontal reinforcement roll reaction forces when the kiss roll is tightened. Because there is no load cell for measuring the upper reinforcing roll reaction force, the right and left difference of the reinforcing roll reaction force P_df ^TBecomes impossible to measure, and the number of unknowns exceeds one. Therefore, in claim 2 of the present invention, the upper thrust force T acting between the upper work roll and the reinforcing roll_WB ^TIs assumed to be zero and the equation is solved. In this case, the equilibrium condition formula for the force and the equilibrium condition formula for the moment in the roll axis direction of each roll disclosed in Patent Document 4 are as follows. That is, the equilibrium conditional expressions of the forces in the roll axis direction of the upper reinforcing roll, the upper working roll, the lower working roll, and the lower reinforcing roll are as follows.
T_B ^T= 0 (9)
-T_WW= T_W ^T(10)
T_WW-T_WB ^B= T_W ^B(11)
T_WB ^B= T_B ^B(12)
The equilibrium condition of the moment of the upper reinforcing roll, the upper working roll, the lower working roll, and the lower reinforcing roll is given by the following equation.

The above unknowns are calculated by solving the above equations (9) to (16) simultaneously. The distance h between the point of application of the thrust reaction force acting on the reinforcing roll and the axial center of the reinforcing roll in FIG._B ^TAnd h_B ^BIs identified in advance by, for example, applying a known thrust force and observing a change in the reaction force of the reinforcing roll.
[0021]
Next, in the plate rolling method according to claim 3 of the present invention, the thrust force acting between the rolls required when calculating the difference between the left and right of the deformation amount of each roll using a constant obtained in advance. A method for calculating the left-right difference of the linear load distribution will be described. As described above, the upper and lower and left and right reinforcement roll reaction forces can be measured, and the upper and lower one of the left and right reinforcement roll reaction forces and the upper and lower work roll thrust reaction forces can be measured. In the latter case, the latter is exceeded by one and the equation cannot be solved. In claim 3 of the present invention, for example, a new conditional expression is introduced under the following assumption.
(A) The inter-roll cross angle is proportional to the inter-roll thrust force.
(B) What changes within one rolling unit is the minute cross angle of the work roll.
(C) The relative cross angle of the upper and lower reinforcing rolls does not change during one rolling unit.
It has been experimentally confirmed that the above assumption (a) holds with good accuracy when the cross angle is small. The friction coefficient may be different between the reinforcing roll and the work roll and between the upper and lower work rolls. However, since the variable cannot be increased any more, the friction coefficient, that is, the cross angle between the rolls and the thrust force between the rolls are used here. The proportionality constant is assumed to be constant. Further, the assumptions of (b) and (c) are considered to be reasonable assumptions when the gap between the housing and the chock can be controlled to be sufficiently small because the neck strength of the reinforcing roll is much higher than that of the work roll.
[0022]
When the conditional expression is derived according to the above assumption, the following expression (17) is obtained.
T_WW= T_WB ^T+ T_WB ^B+ T_B(17)
Where T_BIs a constant corresponding to the thrust force caused by the fine cloth of the upper reinforcing roll based on the lower reinforcing roll, and must be given in advance. When the number of unknowns exceeds two, in addition to the above-described conditional expression, for example, T_WB ^T= T_WB ^BUnder such assumptions, it is necessary to reduce the number of unknowns by one.
The equation (17) derived as described above is added to the equilibrium condition equation of the force in the roll axis direction and the equilibrium condition equation of the moment described in Patent Literature 4 as a new equation to solve even the condition where the unknowns exceed. Can be requested.
[0023]
Note that the constant T in equation (17)_BCan be determined, for example, by the following method.
T_BHas a physical meaning that it is caused by the relative cross angle between the upper and lower reinforcing rolls as described above, and thus is less likely to fluctuate due to work roll replacement. Therefore, after analyzing the results of rolling reduction for one rolling unit, T_BIs determined, and the value is used for the calculation of the zero reduction after the next work roll change.
In addition, when the deformation characteristics of the rolling mill are to be obtained, the T obtained by learning as described above is used._BMay be stored in a database for each set of reinforcing rolls, and the value may be used when measuring the deformation characteristics of the rolling mill in the kiss roll tightened state.
[0024]
The above description has been made taking a four-high rolling mill as an example. However, in the case of a rolling mill model in which the number of intermediate rolls is further increased, each time the number of intermediate rolls increases, the contact area between the rolls increases by one place. And the right and left difference of the linear load distribution acting on the contact area. On the other hand, as for the available equations, the two equations of the equilibrium condition equation and the moment equilibrium equation of the force in the roll axis direction of the roll are increased. If the thrust reaction force of the intermediate roll can be measured, the other rolls can be measured. Simultaneously with the equations for, it is possible to find all the solutions. Therefore, in the method of claim 2 of the present invention, even in the case of a four-high rolling mill, the thrust reaction force acting on at least all the rolls other than the reinforcing rolls is measured. It is possible to obtain an unknown number such as a left-right difference of a linear load distribution acting between the rolls. According to the method of claim 1 of the present invention, it is possible to similarly obtain an unknown value by setting the thrust force acting on the newly added contact area to zero. If the thrust reaction force acting on the roll can be measured, the accuracy of the solution can be further improved.
According to the method of claim 3 of the present invention, even in the case of a rolling mill having four or more stages, by introducing a new conditional expression according to the above-described assumption, as in the case of the four-high rolling mill, It is possible to obtain an unknown number such as a left-right difference of a linear load distribution acting between the rolls.
[0025]
Next, a description will be given of a method of adjusting a rolling reduction zero point based on the above-described roll force balance condition equation and moment balance equation, and a method of extracting left-right asymmetry of deformation characteristics of a rolling mill.
FIG. 1 is a diagram showing an algorithm of a preferred embodiment for adjusting a rolling zero point of a four-high rolling mill in the sheet rolling method of the present invention. The rolling zero point adjustment is performed after the roll change, and usually, the kiss roll tightening is performed until the reinforcing roll reaction force reaches a predetermined zero adjustment load (F1-1). At this time, the reduction position is temporarily reset to zero after adjusting the reduction level so that the left and right reinforcing roll reaction forces become equal (F1-2). As the reinforcing roll reaction force, the reaction force of the upper or lower reinforcing roll may be used alone, or, for example, the average value of the reaction force of the upper and lower reinforcing rolls may be used. In the algorithm of FIG. 1, the upper and lower and left and right reinforcing roll reaction forces are measured in that state (F1-3), and the thrust force T acting between the upper and lower work rolls is calculated from the above equations (1) to (8)._WWAnd the left and right difference p of each roll line load distribution^df _WB ^T, P^df _WB ^B, P^df _WWIs calculated (F1-4). Using this calculation result, the left / right difference of the roll deformation amount in the zero-roll-down state is calculated, and the left-right difference is converted into the reduction fulcrum position to calculate the correction amount of the reduction zero point position (F1-5). The left-right difference in the roll deformation amount is mainly caused by the left-right asymmetric component of the linear load distribution acting between the rolls, and the main cause is the left-right difference in the roll flat deformation amount, which is the already determined p.^df _WB ^T, P^df _WB ^B, P^df _WWIt can be calculated more immediately. By extrapolating the right and left difference of the total amount of flat deformation at the roll body end position obtained from the calculation result to the pressing fulcrum position of the reinforcing roll, the correction amount of the zero reduction position can be calculated. Based on the correction amount of the roll-down zero position, a position where the roll-down position is moved in a direction to eliminate the left-right asymmetry amount of the roll deformation amount is set as a true zero point. By setting the rolling position zero point in this way, accurate rolling setting can be performed in consideration of the left-right asymmetric load and deformation that occur during actual rolling (F1-6). In order to obtain the same effect, instead of correcting the rolling-down zero point as shown in FIG. 1, such a roll asymmetric deformation amount itself at the time of zero adjustment is stored and actually stored. It is also possible to cope with this by always correcting the amount when setting the rolling down.
[0026]
In the embodiment of the four-high rolling mill according to claim 2 of the present invention, the content of F1-3 in the flow of the algorithm of FIG. In "Measure force", the content of F1-4 is described as "between upper and lower work rolls and lower than the lower and upper work rolls based on the equilibrium condition formula of force in the roll axis direction and the equilibrium condition formula of moment acting on the reinforcing roll and work roll". The calculation can be performed in the same manner by replacing the thrust force acting between the work roll and the reinforcing roll and the difference between the left and right distribution of each roll line load with “calculation”.
[0027]
Further, in the embodiment of the four-high rolling mill according to claim 3 of the present invention, the content of F1-3 in the flow of the algorithm of FIG. T_BRead or "Kiss roll tightening, measure the upper and lower work roll thrust reaction force, lower reinforcement roll reaction force and measure the constant T_BAnd the contents of F1-4 are higher and lower than the condition formulas (17) for equilibrium of the force in the axial direction of the roll acting on the reinforcing roll and the work roll described in JP-A-10-263656, The calculation can be performed in the same way by replacing the thrust force acting between the work rolls and between the lower work roll and the reinforcing roll and the difference between the left and right distribution of the line load of each roll with “calculation”.
[0028]
FIG. 2 shows a data collection procedure for calculating the deformation characteristics of a four-high rolling mill and an algorithm for calculating and extracting the deformation characteristics in the plate rolling method of the present invention. The deformation characteristic referred to herein is a so-called mill stretch, which means a change in a gap between upper and lower work rolls as a result of elastic deformation of a rolling mill when a rolling load is applied. When grasping this mill stretch, the deformation of the roll system can be determined with high accuracy by the existing method, but since the deformation characteristics of the housing and rolling system other than the roll system include many elastic contact surfaces, it is theoretically possible. It is generally difficult to grasp accurately. Therefore, in Japanese Patent Publication No. 4-74084, a kiss roll tightening test is performed in advance before the rolling operation, and the deformation amount of the roll system is calculated and separated from the deformation amount corresponding to each tightening load at that time, and the housing A method for separating the deformation characteristics of the rolling-down system is disclosed. Japanese Patent Application Laid-Open No. 6-182418 discloses a method for independently separating the deformation characteristics of the left and right housings and the rolling-down system. However, in the method disclosed in JP-A-6-182418, since the influence of the thrust force acting between the rolls is not considered at all, sufficient accuracy is obtained when the thrust force between the rolls becomes a certain value or more. There was no problem.
[0029]
The first aspect of the present invention is a technique capable of solving this problem, and measures a vertical and horizontal reinforcing roll reaction force when performing a kiss roll tightening test. Hereinafter, the data collection procedure will be described with reference to FIG. First, the kiss roll is tightened to a predetermined reduction position in a tightened state (F2-1). At this time, the operation is performed in an operation mode in which the left and right reduction positions are changed by the same amount in the same direction while the left-right difference between the reduction positions, that is, the reduction leveling is fixed. As long as the operation is performed in the simultaneous reduction mode, the reduction level does not change. At this time, the actual value of each rolling position and the reaction force of the vertical and horizontal reinforcing rolls are measured (F2-2, F2-3). Next, in the left and right simultaneous reduction mode, the reduction device is tightened by a fixed amount, the above measurement is performed, and the process is repeated until data collection at a predetermined reduction position level is completed. That is, it is determined whether or not data collection is completed in F2-4. If No, the rolling position is changed (F2-5). If Yes, the process proceeds to the next step (F2-6). Although it is better to increase the number of the rolling position levels, a practical rolling mill can obtain practical accuracy if data of about 10 to 20 points can be collected. However, at this time, a so-called mill hysteresis often occurs, which causes a difference in a tightening load between the direction in which the screw-down device is tightened and the direction in which the screw-down device is opened. In such a case, at least the tightening direction and the opening direction are different. It is preferable to collect data for one reciprocating operation and perform an operation such as averaging the measured data of both.
[0030]
Next, an algorithm for calculating and extracting the deformation characteristics of the housing / press-down system independently on the left and right sides using the data collected according to the above procedure will be described. First, the measured values of the vertical and horizontal reinforcing roll reaction force for each rolling position condition are extracted (F2-6). Next, in exactly the same manner as in the case of the above-mentioned rolling zero adjustment, the equilibrium conditional expression of the force in the roll axial direction acting on the reinforcing roll and the work roll acting on the work roll and the moment of the moment acting on the reinforcing roll and the work roll are applied. From the equilibrium condition expressions (1) to (8), the thrust force acting between the upper and lower work rolls and the difference between the left and right of each roll line load distribution are calculated (F2-7). If the load distribution between these rolls is determined, the flexural deformation and the flat deformation of the reinforcing roll and the work roll can be calculated by including the left-right difference by the method disclosed in Japanese Patent Publication No. 4-74084, It is possible to calculate the displacement generated at the position of the fulcrum of the reinforcing roll as a result of these deformations (F2-8). Finally, since the deformation amount of the entire mill is evaluated based on the change in the rolling position, the deformation amount of the roll system at the rolling fulcrum position is subtracted from the calculated value, and the deformation characteristics of the housing and the rolling system are independently calculated left and right (F2-9). ). By performing the roll deformation calculation based on the accurate identification of the thrust force between the rolls, the deformation characteristics of the housing / press-down system can be accurately grasped including the left-right difference.
[0031]
The embodiment of calculating the deformation characteristics of the four-high rolling mill according to claim 2 of the present invention describes the contents of F2-3 in the flow of the algorithm of FIG. Measure the force "and the contents of F2-6 to" Extract the measured values of the upper and lower work roll thrust reaction force and the lower reinforcement roll reaction force for each rolling position condition of the kiss roll tightening "and the contents of F2-7 to" Reinforcement roll And the thrust force acting between the upper and lower work rolls and between the lower work roll and the reinforcing roll and each roll line from the equilibrium condition formula of the force in the roll axis direction and the equilibrium condition formula of the moment acting on the work rolls (9) to (16). The calculation can be performed in the same manner by substituting “calculation of left and right of load distribution” with “calculation”.
[0032]
In addition, the embodiment of the deformation characteristics calculation of the four-high rolling mill according to claim 3 of the present invention describes the contents of F2-3 in the flow of the algorithm of FIG._BRead or measure the upper and lower work roll thrust reaction force and lower reinforcement roll reaction force at each pressing position_BIn "Read", the contents of F2-6 are left as it is, or in "Extract the measured values of the upper and lower work roll thrust reaction force and the lower reinforcement roll reaction force for each rolling position condition of kiss roll tightening" According to the equilibrium condition formula of the axial force acting on the reinforcing roll and the working roll described in JP-A-10-263656, the equilibrium condition formula of the moment, and the conditional formula (17), between the upper and lower work rolls and from the lower work roll to the reinforcing roll. The calculation can be carried out similarly by replacing the thrust force acting between them and the left / right difference between the roll line load distributions with “calculation”.
[0033]
FIG. 3 shows a rolling method of a rolling mill according to claim 1, 2 or 3 of the present invention, wherein an optimum rolling leveling is set by using the deformation characteristics of the rolling mill housing / rolling system identified by the above method. Is shown.
First, rolling conditions such as a sheet width of a rolled material to be rolled, an incoming sheet thickness, a target outgoing sheet thickness, a rolling speed, and in the case of hot rolling, deformation resistance characteristic values including a rolling temperature are input ( F3-1). Next, the rolling load is estimated and calculated in consideration of the input rolling conditions and the conditions on the rolling mill side such as the work roll diameter and the work roll elastic constant (F3-2). Next, based on the calculated values of the rolling load and the rolling speed, based on the deformation characteristics of the left and right rolling mill housings and the rolling system identified by the method according to the above-described embodiment, the deformation amount of the sheet rolling mill other than the roll system is determined on the working side. Then, the calculation is individually performed on the driving side (F3-3). Further, a roll system deformation amount is calculated from the rolling load, and a roll gap change at the working end and the drive side end is calculated from the change amount and the deformation amount of the plate rolling mill other than the roll system ( F3-4). Finally, a reduction leveling setting value is calculated from the calculated value of the change in the roll gap and the target value of the thickness difference, that is, the target value of the thickness wedge, and the reduction leveling setting is executed based on the calculated value (F3-5). . Here, the target thickness wedge is usually a symmetrical thickness distribution, that is, the thickness wedge is zero, but there is a thickness wedge that cannot be ignored in the entry side thickness, and this was corrected by one-pass rolling. In this case, when it is determined that meandering, camber, or poor flatness occurs, it is also preferable to set a non-zero thickness wedge target. Further, when the above-described rolling leveling setting is performed, a more accurate rolling leveling setting can be realized by simultaneously correcting the roll asymmetric deformation amount stored at the time of adjusting the rolling zero point.
[0034]
In addition, when dynamic rolling leveling control is performed during rolling, for example, the following may be used: The first class parallel stiffness defined in the paper "Study on Meandering Control Method in Hot Strip Rolling (1st Report)" (Nakajima, Kikuma, Matsumoto, Kajiwara, Kimura, Tagawa) Using the second class parallel stiffness, the fluctuation of the thickness wedge of the rolled material is predicted from the measured data such as the right and left measurement values of the rolling load fluctuation during the rolling, and the rolling leveling control for making this a desired value. The amount is calculated and controlled based on the deformation characteristics of the left and right rolling mill housings and the rolling system. By executing such control, it is possible to suppress meandering and thickness wedges caused by fluctuation factors occurring during rolling to a level having no practical problem.
[0035]
FIG. 4 shows a configuration of a plate rolling mill for carrying out the plate rolling method according to claim 1 or 3 of the present invention. The form is shown. In FIG. 4, a rolling mill 1 includes a work roll 3a, 3b rotatably supported by a housing 2 via work roll chocks 5a, 5b, 5c, 5d and reinforcing roll chocks 6a, 6b, 6c, 6d, and a reinforcing roll 4a. , 4b to form a four-high rolling mill. The housing 2 is provided with a pair of left and right pressing devices 9a and 9b on the working side and the driving side, and controls the gap between the upper and lower working rolls 3a and 3b. Load cells 7a, 7b, 7c, 7d for measuring the reaction force of the reinforcing roll are provided at the positions of the lower and lower fulcrums of the upper and lower reinforcing rolls. By using a four-high rolling mill having such a configuration, it is possible to measure the vertical and horizontal reinforcing roll reaction forces, and the plate rolling method of claim 1 of the present invention can be implemented. FIG. 4 shows the increment work roll bending devices 10a and 10b, the decrease operation roll bending devices 11a and 11b, the reinforcing roll balance devices 12a and 12b, and the pass line height adjustment liners 13a and 13b. However, in the plate rolling mill of the present invention, it is not an essential requirement.
[0036]
In addition, the reinforcing roll reaction force acting on each reduction fulcrum position of the upper and lower reinforcement rolls is usually measured by a load cell, for example, in the case of a rolling mill having a hydraulic reduction device, in a reduction cylinder or in a pipe directly connected to the reduction cylinder. A method of calculating from the measured value of the oil pressure may be used. However, in this case, when the hydraulic pressure is rapidly changing the rolling position, a large error will occur in the measured value, so it is necessary to take measures such as temporarily holding the rolling position when collecting pressure data. There is.
[0037]
FIG. 5 shows a configuration of a plate rolling mill for carrying out the plate rolling method according to claim 2 or 3 of the present invention, which has a measuring device for a vertical working roll thrust reaction force and a measuring device for a lower reinforcing roll reaction force. 1 shows a preferred embodiment of a four-high rolling mill. In FIG. 4, a rolling mill 1 includes a work roll 3a, 3b rotatably supported by a housing 2 via work roll chocks 5a, 5b, 5c, 5d and reinforcing roll chocks 6a, 6b, 6c, 6d, and a reinforcing roll 4a. , 4b to form a four-high rolling mill. The housing 2 is provided with a pair of left and right pressing devices 9a and 9b on the working side and the driving side, and controls the gap between the upper and lower working rolls 3a and 3b. Load cells 7b, 7d for measuring the reaction force of the reinforcing roll are provided at the positions of the left and right pressing fulcrums of the upper and lower reinforcing rolls. The work rolls 3a and 3b are provided with load cells 8a and 8b for measuring a thrust reaction force acting on the work rolls. By using a four-high rolling mill having such a configuration, either the upper or lower reinforcing roll reaction force, that is, the lower left or right reinforcing roll reaction force in the example of FIG. 5, the thrust reaction force acting on the upper and lower work rolls can be measured, and the plate rolling method according to claim 2 of the present invention can be carried out. FIG. 5 shows the increment work roll bending devices 10a and 10b, the decrease operation roll bending devices 11a and 11b, the reinforcing roll balance devices 12a and 12b, and the pass line height adjustment liners 13a and 13b. However, it is not an essential requirement in the plate rolling mill of the present invention.
[0038]
FIG. 5 shows an example in which the thrust reaction force of the work roll is measured by the load cells 8a and 8b. When the actuator of the work roll shift device is a hydraulic cylinder, the load cells 8a and 8b are replaced with a hydraulic cylinder or a hydraulic cylinder. The work roll thrust reaction force measuring device may be substituted by a pressure measuring device that measures the pressure of a directly connected hydraulic pipe. In the case where the work roll shift device is not provided, a thrust reaction force measuring device provided in the roll chock of the work roll or a device for measuring a load acting on a keeper plate for restraining the work roll chock in the roll axis direction may be adopted. Just fine.
[0039]
As described above, in the present invention, a rolling mill that does not have all the measuring devices for the thrust reaction force acting on the rolls other than the reinforcement rolls and the reinforcement roll reaction force acting on the respective lower fulcrum positions of the upper and lower reinforcement rolls. In addition, the zero point of the rolling mill and the deformation characteristics of the rolling mill are determined with good reproducibility, and the rolling position setting and control of the rolling mill using the results are carried out, so that the frequency of occurrence of meandering and threading troubles in the rolling operation And the camber of rolled material and the thickness wedge can be significantly reduced.
[0040]
【Example】
An example in which the plate rolling method of the present invention is applied to a hot finishing rolling mill having seven four-high rolling mills 24a to 24g as shown in FIG. 6 will be described.
In FIG. 6, reference numeral 20 denotes a rolled material, 21 denotes a moving direction of the rolled material, 22 denotes an arithmetic processing unit, and 23 denotes a rolling position control device. All of the four-high rolling mills 24a to 24g are equipped with load cells 25a to 25g for measuring the lower reinforcement roll reaction force, which can be detected independently on the left and right, and electric rolling devices 26a to 26g, which can be operated independently on the left and right (FIG. 6, one of the left and right sides is shown), and the four-high rolling mills 24a to 24c of the first to third stands are equipped with upper reinforcing roll reaction force measurement load cells 27a to 27c that can be detected independently of the left and right sides (FIG. 6). 6 shows one of the right and left sides). Fourth-high rolling mills 24d, 24f and 24g of the fourth, sixth and seventh stands have upper thrust reaction force measurement load cells 28d, 28f and 28g capable of measuring the thrust reaction force acting in the roll axis direction of the upper and lower work rolls. And lower thrust reaction force measurement load cells 29d, 29f, and 29g (one of left and right is shown in FIG. 6). In addition, hydraulic pressure reduction devices 30e to 30g and hydraulic cylinder pressure measurement devices 31e to 31g are provided on the upper part of the fifth, sixth and seventh stands on the left and right sides (one of the right and left sides is shown in FIG. 6). The hydraulic pressure reduction devices 30e to 30g also have a function of temporarily holding the pressure reduction position. By measuring the hydraulic pressure of the hydraulic cylinder pressure measurement devices 31e to 31g, it is possible to obtain the right and left upper reinforcing roll reaction forces. Is possible.
[0041]
In the arithmetic processing unit 22, the sensors provided in each stand, namely, the lower reinforcement roll reaction force measurement load cells 25a to 25g, the upper reinforcement roll reaction force measurement load cells 27a to 27c, and the upper work roll thrust reaction force measurement load cell 28d , 28f, 28g, lower work roll thrust reaction force measurement load cells 29d, 29f, 29g, and hydraulic cylinder pressure measuring devices 31e to 31g are read, and based on these measured values, the right and left pressing positions of each stand are read. Set values and / or control values are calculated, and these are sent to the rolling position control device 23. The rolling-down position control device 23 has a configuration in which the electric rolling-down devices 26a to 26g of each stand can be independently operated left and right on the basis of the above-described rolling-down position set value and / or control value, and the rolling-down leveling setting / control can be performed. ing.
[0042]
In FIG. 6, in the rolling mills of the first to third and fifth stands, it is possible to measure the vertical and horizontal reinforcing roll reaction forces. The method can be implemented. Further, in the rolling mill of the fourth stand, it is possible to measure the reaction force of the lower left and right reinforcing rolls and the thrust reaction force acting on the upper and lower work rolls. The method can be implemented.
[0043]
Using the rolling mill having such a configuration, the conventional method and the method of the present invention were compared with respect to the setting and control of the rolling position during rolling based on the zero point of the rolling device and the deformation characteristics of the rolling mill. In addition, since the thrust reaction force of the upper and lower work rolls and the reaction force of the upper and lower reinforcement rolls can be measured for the sixth and seventh stands, the method disclosed in Patent Document 4 is applied as it is, For the fifth stand, a comparison was made between the conventional method and the method of the present invention.
[0044]
First, in the conventional method, the method disclosed in Patent Literature 4 cannot be applied because the measuring devices are insufficient at the first to fifth stands. Are adjusted to be equal to each other, and based on the deformation characteristics of the rolling mill housing and the rolling system identified by the method disclosed in Patent Document 3, the rolling leveling setting before rolling and the rolling leveling control during rolling are performed. Carried out. As a result, when rolling a thin wide material having an exit side plate thickness of 1.2 mm and a width of 1200 mm, a plate thickness wedge and a camber were generated, and narrowing due to meandering in the fifth stand was generated.
[0045]
On the other hand, in the method of the present invention, the plate rolling method of the present invention is applied to the first to third and fifth stands, and the sheet rolling method of the present invention is applied to the fourth stand. The rolling level setting before rolling was performed based on the deformation characteristics of the rolling mill and the rolling leveling control during rolling were performed. As a result, even when a thin material having a delivery side thickness of 1.2 mm and a width of 1200 mm, which has been narrowed down by the conventional method, is rolled, the occurrence of a thickness wedge and a camber is small, and the rolled material is passed straight through the rolling line. I was able to.
[0046]
As described above, in the method of the present invention, the thrust reaction force acting on the rolls other than the reinforcement rolls, and the rolling device that does not have all the measurement devices for the reinforcement roll reaction forces acting on the positions of the lowering fulcrum of the upper and lower reinforcement rolls are provided. In the rolling mill, the zero point of the rolling device and the deformation characteristics of the rolling mill are determined with good reproducibility, and the rolling position of the rolling mill is set and controlled using the results. It was proved that a stable rolling operation without wedges and cambers could be realized.
[0047]
【The invention's effect】
According to the present invention, the rolling leveling setting and control of the rolling mill, which has conventionally relied on the operator, can be automated, and more accurate and appropriate rolling leveling setting and control than before can be performed. Since the frequency of occurrence of troubles can be greatly reduced, and the camber and the thickness wedge of the rolled material can be significantly reduced, it is possible to simultaneously reduce the cost required for rolling and improve the quality.
[Brief description of the drawings]
FIG. 1 is a diagram showing an algorithm of a preferred embodiment of a method for adjusting a rolling reduction zero point in the case of a four-high rolling mill in the sheet rolling method according to claim 1 of the present invention.
FIG. 2 is a diagram showing a procedure of actual machine data measurement for identifying deformation characteristics and an algorithm of a deformation characteristics calculation in a preferred embodiment of a four-high rolling mill in the sheet rolling method of the present invention.
FIG. 3 is a diagram showing an algorithm of a preferred embodiment of a rolling position setting method in the case of a four-high rolling mill in the sheet rolling method according to claim 1, 2 or 3 of the present invention.
FIG. 4 shows a configuration of a plate rolling mill for carrying out the sheet rolling method according to claim 1 or 3 of the present invention, which is preferable in the case of a four-high rolling mill having load cells for measuring a reinforcing roll reaction force in the vertical and horizontal directions. FIG.
FIG. 5 shows a configuration of a plate rolling mill for carrying out the plate rolling method according to claim 2 or 3 of the present invention, which has a measuring device for a vertical working roll thrust reaction force and a measuring device for a lower reinforcing roll reaction force. The figure which shows the preferable embodiment in the case of a step rolling mill.
FIG. 6 is a diagram showing an example in which the sheet rolling method of the present invention is applied to a hot finishing rolling mill having seven four-high rolling mills.
FIG. 7 is a schematic diagram showing left-right asymmetric components of a force in a roll axis direction and a force in a vertical direction acting on each roll of a four-high rolling mill.
[Explanation of symbols]
1 ... 4-high rolling mill 2 ... Housing
3a, 3b: Work roll # 4a, 4b: Reinforcement roll
5a, 5b, 5c, 5d ... Work roll chock
6a, 6b, 6c, 6d ... reinforcing roll chock
7a, 7b, 7c, 7d ... load cell for measuring the reinforcing roll reaction force
8a, 8b ... Load cell for thrust reaction force measurement
9a, 9b ... reduction device
10a, 10b ... Roll work roll bending device
11a, 11b ... Decrease work roll bending device
12a, 12b ... reinforcing roll balance device
13a, 13b ... pass line height adjustment liner
14a, 14b: Keeper plate
15a, 15b, 15c, 15d ... Output of load cell for measuring the reinforcing roll reaction force
16 ... Line load distribution between upper work roll and upper reinforcing roll
17 ... Line load distribution between upper and lower work rolls
18 ... Line load distribution between lower work roll and lower reinforcing roll
20: rolled material # 21: moving direction of rolled material
22: arithmetic processing unit # 23: rolling position control unit
24a to 24g ... 4 high rolling mill
25a-25g ... Load cell for measuring the lower reinforcement roll reaction force
26a-26g ... Electric screw down device
27a to 27c: Load cell for measuring the upper reinforcing roll reaction force
28d, 28f, 28g: Load cell for measuring upper working roll thrust reaction force
29d, 29f, 29g… Load cell for lower work roll thrust reaction force measurement
30e-30g ... Hydraulic pressure reduction device
31e-31g ... hydraulic cylinder pressure measuring device

Claims (3)

In the rolling method using a multi-stage plate rolling mill of four or more stages, in the kiss roll tightened state, from the measured values of the reinforcing roll reaction force acting in the rolling direction at each rolling fulcrum position of the upper and lower reinforcing rolls, the zero point of the rolling-down device A sheet rolling method characterized in that one or both of the deformation characteristics of a rolling mill are obtained, and a rolling position is set and / or controlled at the time of rolling, based on this. In a rolling method using a multi-stage rolling mill of four or more stages, in the kiss roll tightened state, the measured value of the thrust reaction force acting on the roll axis direction of all the rolls among the work roll, the work roll, and the intermediate roll, Only one or both of the zero point of the rolling device and the deformation characteristics of the rolling mill are obtained from only the measured values of the reinforcing roll reaction force acting in the rolling direction at each rolling fulcrum position of one of the upper and lower reinforcing rolls. And setting and / or controlling a rolling position when rolling is performed. 3. The sheet rolling method according to claim 1, wherein a constant determined in advance is used when determining one or both of the zero point of the rolling device and the deformation characteristic of the rolling mill.

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