HYDRAULIC PRESS Russian patent published in 2003 - IPC

FIELD: plastic metal working. SUBSTANCE: the hydraulic press has a piston power cylinder, pumping plant, booster made in the form of two aligned high-pressure and low-pressure plunger cylinders, system of distributors including a four-way three-position reversing valve, two three-way two-position and two two-way two-position riding cut-off valves. 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 input of one of the three-way valves is connected to the second output of the reversing valve, the input of the other one - to the working rod end of the power cylinder, the open output of the first valve is connected to the closed output of the second valve and to the high-pressure cylinder of the booster, and the closed output of the first valve is connected to the open output of the second valve and to the low-pressure cylinder of the booster. Both cylinders of the booster through the closed rigging cut-off valves are separately connected to the drain line. The necessary combinations of valve positions provide 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 the booster acts as a pressure regulator, during the working running liquid is fed to the rod end of the power cylinder directly from the pumps, or the booster is used for the direct purpose. During the reverse running the piston of the power cylinder and the booster movable unit are reset, for filling the booster cylinders use is made of the liquid displaced from the rod end of the power cylinder. EFFECT: enhanced efficiency and capacity of the press. 1 dwg