HYDRAULIC PRESS Russian patent published in 2003 - IPC

FIELD: plastic metal working. SUBSTANCE: the hydraulic press has a piston power cylinder, pumping plant, system of distributors including a four-way three-position reversing valve, two-way two-position and two-three-way two-position valves, booster and a pressure regulator each made in the form of input and output aligned plunger cylinders. The inputs of the reversing valve are connected to the pumping plant, and one of the outputs - to the return rod end of the power cylinder. The output cylinders of the pressure regulator and booster are connected to the working piston end of the power cylinder, and an open rigid cut-off valve is installed in the pipe-line of the output cylinder of the pressure regulator. Connected to the second output of the reversing valve is the input of the main three-way two-position valve, whose closed output is connected to the rod end of the power cylinder, and connected to its open output is the input of the additional three-way two-position valve, and the open output of the additional valve is connected to the input cylinder of the pressure regulator, the closed output - to the input cylinder of the booster. The necessary combination of valve positions provides the working cycle of the press, including the periods of idle running, working running with two speed and pressure stages, reverse running. During the idle running liquid is fed to the rod end of the power cylinder with employment of the booster, during the working running - directly from the pumping plant with employment of the booster. During the reverse running the movable units of the pressure regulator and booster are reset, and for filling of their output cylinders use is made of liquid displaced from the rod end of the power cylinder. EFFECT: enhanced efficiency, capacity and reliability of the press. 2 cl, 1 dwg