| 摘要 |
PURPOSE:To improve the responsiveness of the hydraulic screw down device, by hydraulically communicating two oil chambers of the screw down cylinder respectively to two oil chambers of the intermediate cylinder, and by driving the intermediate cylinder so as to make the working speed, etc., in the roll-gap-reducing direction conform to that in the roll-gap-widening direction. CONSTITUTION:If the roll-gap-reducing command is produced, the oil amount of the oil chamber F of the double-acting cylinder 10 of the driving unit increases, and the oil amount of the oil chamber E decreases, so that the piston 16 moves leftward. Since the intermediate cylinder's piston 15 is mechanically connected to the piston 16, the piston 15 similarly moves leftward and compresses the oil of the oil chamber 5. As a result, the oil pressure of the oil chamber C of the screw down cylinder 8 increases, and thereby the screw down cylinder's ram moves upward or increases the rolling force. Whereas, if the roll-gap-widening command is produced, the oil pressure of the oil chamber D of the cylinder 8 increases and the screw down ram 7 is pushed down contrary to above-mentioned movements. Accordingly, the working speed, working force, etc., of the screw down cylinder in the roll-gap- reducing direction can be conformed to that in the roll-gap-widening direction so that the respectiveness of the hydraulic screw down device can be improved. |
