The invention relates to a simple hydraulic
system for a bending
machine. The simple hydraulic
system comprises an axle
plunger pump, a screen
oil filter, an
oil tank, a
pilot operated
check valve, a three-position four-way electromagnetic
directional valve, a two-position two-way electromagnetic
directional valve, a pressure gauge, a one-way
throttle valve, two prefill valves, an overflow valve, two oil cylinders and a
safety valve. The axial
plunger pump is connected with a motor and further connected with the
oil tank through the screen
oil filter, and one way of the axial
plunger pump is connected to the overflow valve while the other way of the axial
plunger pump is connected to the three-position four-way electromagnetic
directional valve. One operation port of the three-position four-way electromagnetic directional valve is connected with the
safety valve and the
pilot operated
check valve for pressure maintaining and further connected with rod cavity of the two oil cylinders, rodless cavities of the two oil cylinders are connected with the prefill valves respectively, control oil circuits of the two prefill valves are connected with the two-position two-way electromagnetic directional valve and forms a loop with the other operation port of the three-position four-way electromagnetic directional valve. By the simple hydraulic
system for the bending
machine, an
electrical control system of a mainframe is simplified, manufacturing cost of the mainframe is reduced, and convenience and simplicity in operation of the mainframe is achieved. In addition, the simple hydraulic system for the bending
machine has the advantages of high efficiency and energy saving and has functions of pressure maintaining and overload protection.