Abstract: A cold rolling method, cold rolling equipment, and a cold-rolled steel sheet manufacturing method capable of preventing sheet breakage by sufficiently suppressing occurrence of an edge crack of a material to be rolled during cold rolling. In the cold rolling method, a rolling mill including a plurality of stands to cold-rolls a material to be rolled. An N-th stand (N is a natural number equal to or greater than 2) arranged in an N-th position from an upstream side of the material to be rolled in a transfer direction among the plurality of stands, includes a tapered work roll having a taper formed on an end portion of a roll having a uniform diameter. The N-th stand rolls the material to be rolled with a linear load of 0.8 t/mm or more.

Abstract: A chattering detection method for a cold rolling mill, the method including: measuring a vibration of a cold rolling mill; calculating a time waveform of vibration intensity by performing frequency analysis on a time waveform of the measured vibration of the cold rolling mill for a predetermined period equal to or shorter than a time in which a periodic vibration continues without converging; and detecting a chattering sign vibration of the cold rolling mill based on a number of points having vibration intensity values that exceed a predetermined threshold, the points being included in the calculated time waveform of the vibration intensity.

Abstract: A rolling oil supply system is configured to supply rolling oil to a rolling stand selected from a plurality of rolling stands included in a tandem rolling mill, a first rolling oil supply system configured to circulate and supply rolling oil after removing wear powder generated by rolling, and a second rolling oil supply system configured to supply rolling oil containing the wear powder generated by rolling are provided. Mixed rolling oil in which the rolling oil supplied from the first rolling oil supply system and the rolling oil supplied from the second rolling oil supply system are mixed is supplied to selected fourth and fifth rolling stands.

Abstract: A rolling oil supply system is configured to supply rolling oil to a rolling stand selected from a plurality of rolling stands included in a tandem rolling mill, a first rolling oil supply system configured to circulate and supply rolling oil after removing wear powder generated by rolling, and a second rolling oil supply system configured to supply rolling oil containing the wear powder generated by rolling are provided. Mixed rolling oil in which the rolling oil supplied from the first rolling oil supply system and the rolling oil supplied from the second rolling oil supply system are mixed is supplied to selected fourth and fifth rolling stands.

Abstract: A chattering detection method for a cold rolling mill, the method including: measuring a vibration of a cold rolling mill; calculating a time waveform of vibration intensity by performing frequency analysis on a time waveform of the measured vibration of the cold rolling mill for a predetermined period equal to or shorter than a time in which a periodic vibration continues without converging; and detecting a chattering sign vibration of the cold rolling mill based on a number of points having vibration intensity values that exceed a predetermined threshold, the points being included in the calculated time waveform of the vibration intensity.