HYDRAULICALLY CONTROLLED TELESCOPIC JIB OF A SHIP CRANE Russian patent published in 2022 - IPC B66C23/70 

FIELD: hoisting and transport engineering.

SUBSTANCE: invention relates to the field of hoisting and transport engineering and can be used in cranes with hydraulically controlled multi-stage telescopic boom. The telescopic boom includes a root section made in the form of a box-section beam, retractable sections telescopically installed in each other inside the root section and each equipped with a hydraulic cylinder for sequential extension and retraction of the retractable sections, and a hydraulic circuit for working fluid, including a tank for working fluid, extension pipeline and retraction pipeline. Hydraulic cylinders of retractable sections, with the exception of the section farthest from the root section, are made with a hollow rod and equipped with a telescopic pipeline built into these hydraulic cylinders, having two pipes inserted into each other, which are made with the possibility of telescopic movement relative to each other. One of the two pipes is permanently made in the hydraulic cylinder body, the second pipe is permanently made in the hydraulic cylinder rod, and one of them has a recess in the side surface in the end region. The hydraulic circuit for the working fluid includes blocks for regulating the flow of the working fluid, each of these blocks, hydraulically connected to the corresponding hydraulic cylinder equipped with a built-in telescopic pipeline, has a pressure channel in which a check valve is made to ensure the flow of the working fluid under pressure into the piston cavity of the hydraulic cylinder , with which this unit is connected, has a free drain channel, in which a check valve is made to ensure movement along the telescopic pipeline built into this hydraulic cylinder for the flow of the working fluid displaced from the piston cavities of successively retracted hydraulic cylinders, and has an adjustable drain channel, in which a safety pressure valve is made, passing through itself the flow of working fluid displaced from the piston cavity of the hydraulic cylinder with which this block is connected, when the pressure at the inlet to this valve is reached, set by the setting of this valve, and the setting of the safety pressure valves in all blocks for regulating the flow of the working fluid is designed so that the sequence of set pressure values, starting from the block closest to the root section, has the form of a decreasing numerical series.

EFFECT: increased reliability and durability of a hydraulically driven telescopic boom of a ship crane.

1 cl, 4 dwg