Forging die,and method and apparatus for controlling the same

摘要

A hydraulic pressure control apparatus comprises a high pressure accumulator for sucking pressure oil supplied to a relief chamber of a relief valve to make changeover for the relief valve from a valve-closed state to a valve-open state when a forming load is applied to the pressure oil charged in a pressure chamber and the hydraulic pressure of the pressure oil arrives at a relief preset pressure, and a low pressure accumulator for sucking the pressure oil charged in the pressure chamber via the relief valve which is in the valve-open state.