Positive/negative bending apparatus for work roll of rolling mill

The utility model relates to a positive/negative working roll bending device of a rolling mill, which comprises four upper roll bending blocks and four lower roll bending blocks; the lower roll bending blocks and the upper roll bending blocks are matched and respectively arranged at the bearing pedestals (5) positioned at two ends of an upper working roll and a lower working roll; the upper roll bending blocks and the lower roll bending blocks are provided with coaxial stepped holes in which hydraulic cylinder components are arranged; the hydraulic cylinder components comprise upper sealing covers (8), sealing rings (10), lower sealing covers (13) as well as separator pistons (14) and pistons (12), wherein, the separator pistons (14) and pistons (12) are arranged in lower roll bending blocks; piston rods (1) penetrate through the upper sealing covers and enter in the holes of the upper roll bending blocks; the upper ends of the piston rods (1) are provided with nuts and upper gland bushes (3); and positive bent oil inlets (18) and negative bent oil inlets (17) are arranged on the lower roll bending blocks (11). The utility model not only ensures the positive/negative working roll bending funcition, but also reduces the processing procedures of parts and components and simplifies the cohesive relations of composite junctions, and improves the whole processing and assembly precision.