Apparatus for detecting eccentricity of roll in rolling mill

Claim 1

An apparatus for detecting a roll eccentricity in a rolling mill comprising: mark pulse generators provided, respectively, for upper and lower rolls from which an eccentricity is to be detected, said mark pulse generators genterating, respectively, one pulse per one rotation of said rolls, and sampling pulse generators provided, respectively, for said upper and lower rolls for generating, respectively, n pulses per one rotation of said rolls; a rolling pressure detector for detecting a rolling pressure of said rolls and outputting a rolling pressure signal indicative thereof; a roll eccentricity calculation/memory unit which, during rotation of said rolls, samples the rolling pressure signal outputted from said rolling pressure detector at the output timings of said sampling pulse generators after the time when said mark pulse generators generate said mark pulses, and calculates to store the roll eccentricity of each of said rolls based on said rolling pressure signal; a Fourier transformation/calculation unit for calculating a difference between outputs from said roll eccentricity calculation/memory unit and performing a Fourier transformation of said difference, said outputs corresponding to those before and after relative phases of said upper and lower rolls are changed; an angle calculation unit for outputting signals regarding the rotary angle and said relative phase of each of said rolls, based on the outputs form said mark pulse generators and said sampling generators; and an eccentricity quantities outputting unit for outputting the eccentricity quantity independently for each of said rolls, based on the output signals from said Fourier transformation calculation unit and said angle calculation unit.

Claim 2

An apparatus for detecting a roll eccentricity in a rolling mill comprising: mark pulse generators provided, respectively, for upper and lower rolls from which an eccentricity is to be detected, said mark pulse generators genterating, respectively, one pulse per one rotation of said rolls, and sampling pulse generators provided, respectively, for said upper and lower rolls for generating, respectively, n pulses per one rotation of said rolls; a rolling pressure detector for detecting a rolling pressure of said rolls and outputting a rolling pressure signal indicative thereof; a roll eccentricity calculation/memory unit which, during rotation of said rolls, samples the rolling pressure signal outputted from said rolling pressure detector at the output timings of said sampling pulse generators after the time when said mark pulse generators generate said mark pulses, and calculates to store the roll eccentricity of each of said rolls based on said rolling pressure signal; a Fourier transformation/calculation unit for calculating a difference between outputs from said roll eccentricity calculation/memory unit and performing a Fourier transformation of said difference, said outputs corresponding to those before and after relative phases of said upper and lower rolls are changed; an angle calculation unit for outputting signals regarding the rotary angle and said relative phase of each of said rolls, based on the outputs form said mark pulse generators and said sampling generators; and an eccentricity quantities outputting unit for outputting the eccentricity quantity independently for each of said rolls, based on the output signals from said Fourier transformation calculation unit and said angle calculation unit.