HYDRAULIC FORGING PRESS AND METHOD FOR CONTROLLING SAME

Provided herein are a hydraulic forging press machine and a method for controlling the same, whereby surging of the forging load or dead zones where the forging speed goes to zero can be suppressed, and forging can be performed with high precision throughout a wider range than in the prior art from a low load to a high load. The present invention is characterized by including a plurality of pressure cylinders (pressure cylinder group (2)), the pressure cylinder group (2) having a main pressure cylinder (21) configured so that working fluid can always be supplied thereto during forging, and a plurality of secondary pressure cylinders (22-25) configured so that supplying and stopping of the supply of working fluid thereto can be switched in response to the forging load, head-side hydraulic chambers (22h-25h) of the secondary pressure cylinders (22-25) being connected to a head-side hydraulic chamber (21h) of the main pressure cylinder (21) via electromagnetic switching valves (2a), and the present invention being configured so that only the main pressure cylinder (21) is used until the forging load exceeds a predetermined set load, and the number of secondary pressure cylinders (22-25) used is sequentially increased as the forging load increases after the forging load exceeds the set load.