Quick joint with pressure limit function

Abstract

The invention discloses a quick joint with a pressure limit function. The quick joint is characterized by comprising a joint body, a base, a valve element arranged in the joint body, a first spring, a second spring, a valve sleeve and a valve base, wherein the valve element, the valve sleeve, the second spring and a nut constitute an overflow valve; the first spring is coaxially arranged in the valve sleeve and the valve base and supplies thrust to the valve sleeve; the second spring is coaxially arranged in the valve base and the valve sleeve; the valve sleeve and the valve base are respectively provided with steps used for propping against two ends of the first spring and one end of the second spring; the valve base is fixed by virtue of the joint body and the base; the valve sleeve slides under guidance of the external cylindrical surface of the valve base. The quick joint has the beneficial effects that the overflow valve is directly integrated in the quick joint, so that additional elements are avoided, an oil way of a hydraulic system is simplified, an element protection device is not needed to be additionally arranged, and the quick joint has an antipollution effect.

Description

technical field [0001] The invention relates to a quick joint, in particular to a quick joint with pressure-limiting function. Background technique [0002] Taking large-tonnage crawler cranes as an example, the main parts of the machine need to be disassembled and transported in separate parts when the whole machine is transported, which makes the hydraulic pipelines laid inside the parts to be disassembled together. It is connected with quick connectors that are more convenient to disassemble and install, and make the separated two parts of the oil circuit form their own closed oil chambers, such as figure 1 (a) (b) shown. [0003] Taking the use of motors and hydraulic cylinders as an example, when the hydraulic motor is working, the housing needs a separate drain oil circuit to lead back to the oil tank; however, after the components are disassembled, this part of the oil circuit also needs to be disconnected through the quick connector, so that the motor housing A clo...

AI Technical Summary

Problems solved by technology

[0003] Taking the use of motors and hydraulic cylinders as an example, when the hydraulic motor is working, the housing needs a separate drain oil circuit to lead back to the oil tank; however, after the components are disassembled, this part of the oil circuit also needs to be disconnected through the quick connector, so that the motor housing A closed cavity is formed inside the body, hydraulic pipeline and quick connector. Due to the large volume expansion coefficient of the hydraulic oil, when the ambient temperature rises high, the hydraulic oil in the closed cavity will expand and cause the cavity to The oil pressure rises, causing the motor shaft seal to be damaged or even the motor casing to be broken

For crawler cranes, most of the hydraulic cylinders are carried by the large cavity, and the pressure is maintained through the load holding valve. After the load holding valve, the reversing valve is connected to the oil tank indirectly through the quick joint; after the hydraulic cylinder is disassembled and transported, both the large cavity and the small cavity pass through The quick connector is closed; if the ambient temperature rises, the hydraulic oil in the large and small oil chambers of the cylinder will expand, causing the pressure to rise. Because there is a large difference in the area of ​​the large and small chambers, the large chamber bears a large force and directly acts on the small chamber, so the pressure in the small chamber It is often several times higher than that of the large cavity (the ratio of the effective area of ​​the large cavity to the area of ​​the small cavity), which causes the hydraulic oil in the small cavity to release pressure through the internal sealing ring of the cylinder or the seal of the guide sleeve, resulting in failure of the cylinder seal or even cylinder expansion. big and totally scrapped

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