STEEL PLATE LIFTING METHOD AND LIFTING DEVICE, AND STEEL PLATE MANUFACTURING METHOD

To provide a method and a device for lifting a thin steel plate, which can stably lift a thin steel plate, and a method for manufacturing a steel plate, which can improve the work efficiency of manufacturing the steel plate.SOLUTION: A steel plate lifting method using a lifting magnet with a magnetic pole and an electromagnetic coil to lift at least one steel plate from a stack of a plurality of steel plates as an object to be lifted includes a lifting process in which a voltage is applied to the electromagnet coil so that the magnetic pole magnetic flux density becomes the target magnetic flux density, and the lifting magnet is raised to lift the object to be lifted. The steel plate lifting method includes a holding process of holding the object to be lifted by increasing the voltage applied to the electromagnetic coil when the decrease in a second magnetic flux density, which is the magnetic pole flux density in the state after the lifting magnet start to rise relative to a first magnetic flux density, which is the magnetic flux density of the magnetic poles in the state before the lifting magnets start to rise when the object to be lifted is attracted to the magnetic poles is equal to or greater than a dynamic lift off detection threshold.SELECTED DRAWING: Figure 5 【課題】薄い鋼板を安定に吊り上げることができる鋼板の吊上方法及び装置、並びに、鋼板の製造の作業効率を向上できる鋼板の製造方法を提供する。【解決手段】磁極と電磁石コイルとを有するリフティングマグネットを用いて、積み重ねられた複数枚の鋼板の中から少なくとも１枚の鋼板を吊上対象として吊り上げる、鋼板の吊上方法は、磁極磁束密度が目標磁束密度になるように電磁石コイルに電圧を印加し、リフティングマグネットを上昇させることによって吊上対象を吊り上げる吊上工程を含む。鋼板の吊上方法は、磁極に吊上対象が吸着し、かつ、リフティングマグネットが上昇し始める前の状態における磁極磁束密度である第１磁束密度に対する、リフティングマグネットが上昇し始めた後の状態における磁極磁束密度である第２磁束密度の低下量が地切り検知閾値以上である場合に電磁石コイルに印加する電圧を増加させて吊上対象を保持する保持工程を含む。【選択図】図５