Mechanical balance valve with foldable cantilever crane

Abstract

The invention discloses a mechanical balance valve with a foldable cantilever crane. The mechanical balance valve comprises a first oil port, a second oil port, a valve body, a control valve core, a balance valve core, a high-pressure cavity and low-pressure cavity isolating block and an overflow valve core, wherein the valve body is provided with a pilot control oil cavity, a load cavity and a pilot valve spring cavity; the first oil port is communicated with the pilot control oil cavity; the second oil port is communicated with the load cavity; the control valve core is arranged in the pilot control oil cavity; the balance valve core is arranged in the load cavity; the pilot control oil cavity is isolated from the load cavity; the balance valve core comprises a valve head and a valve rod; the valve head is arranged at one end, which faces the control valve core, of the valve rod; the valve rod passes through a center hole of the high-pressure cavity and low-pressure cavity isolating block; a spring is arranged between the valve head and the high-pressure cavity and low-pressure cavity isolating block; a through hole is formed in the center of the valve rod; a small pilot valve core is arranged in the hole; the small pilot valve core is provided with a groove which is communicated with the load cavity and a high-pressure unloading cavity. The mechanical balance valve has the advantages of high dynamic stability, low control pressure and high locking property.

Description

technical field [0001] The invention relates to a balance valve, in particular to a mechanical balance valve with a folding arm. Background technique [0002] At present, with the rapid development of construction machinery, there are various machines with articulated booms and folding booms, such as articulated lifting platforms, concrete pump trucks, folding cranes, folding Cranes, aerial work platform lifts, etc. Compared with general machinery, this type of machinery is high-altitude operation equipment, and its working load changes frequently with the change of the angle between the booms. The static and dynamic performance requirements of the valve are quite high. [0003] Traditional balance valves applied to multi-section boom balance circuits are likely to cause low-frequency vibration of the actuator, and because traditional balance valves generally adopt a slide valve structure, there is a certain internal leakage, and it is difficult to lock the boom in a certa...

AI Technical Summary

Problems solved by technology

The improved balance valve introduces high-pressure oil into the entire spring chamber when it is self-locking, resulting in a large area of ​​action of high-pressure oil, which causes the main valve core to bear excessive stress and seriously affects its service life; at the same time, the leakage of the pilot valve core during movement from the load chamber, which causes the boom to drop prematurely

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