METHOD FOR PREVENTING DEFORMATION AND VIBRATION OF SEAL ROLL OF CONTINUOUS VACUUM DEPOSITION PLATING DEVICE AND STRUCTURE THEREFOR

PURPOSE:To prevent the deformation of seal rolls due to the difference in the thermal expansion and to prevent the generation of cracks on the surface of a steel sheet passing between the rolls by heating the inside of a continuous vacuum deposition plating device with high-temp. oil as the heating medium. CONSTITUTION:The air isolating seal roll SR in the continuous vacuum deposition plating device is formed by a main roll body 1 and an outer sleeve 3, and the passage for the high-temp. oil as the heating medium is formed by plural grooves 6 of the same shape provided on the surface of the main roll body 1 at regular intervals and the sleeve 3. When a steel sheet S to be worked is passed from the high-pressure side to the low-pressure side between the two seal rolls SR, the gas passes from the high-pressure side to the low-pressure side at the velocity of >= 80% of the sonic velocity and passes through the gap with a seal bar SB at a high velocity, hence the part A of the seal roll is cooled, the part B coming into contact with the steel sheet S is heated by the frictional heat, and the part C is cooled by the forced convection of the gas due to the rotation of the roll. In this case, the temp. of the whole seal roll is uniformized by passing the high-temp. oil in the groove 6, and the deformation due to the partial temp. difference can be eliminated.