Pilot-operated type hydraulic lock

Abstract

The invention discloses a pilot-operated type hydraulic lock. The pilot-operated type hydraulic lock comprises a valve sleeve (1), a plug (2), a valve element (3) and a pilot-operated cone valve element (4). A step hole A (5) is formed in the right end portion of the plug (2), the inner wall of a big hole of the step hole A (5) is provided with an inner thread (6), the column face of the left endof the valve sleeve (1) is provided with an outer thread (7), and the column face of the right end of the valve sleeve (1) is provided with a radial hole (8) around the circumferential direction of the valve sleeve (1). The valve sleeve (1) is internally and sequentially provided with a guiding hole (9), an annular cavity (10) and an oil inlet hole (11) in the axial direction of the valve sleeve (1) from left to right. The annular cavity (10) communicates with the radial hole (8), and the butt joint position of the oil inlet hole (11) and the annular cavity (10) is provided with a valve seat (12). The pilot-operated type hydraulic lock has the beneficial effects that the structure is compact, stable heavy object descending and ascending are ensured, actions are sensitive, and operation issimple.

Description

technical field [0001] The invention relates to the technical field of hydraulic lock structures, in particular to a pilot hydraulic lock. Background technique [0002] In the application of construction machinery, agricultural machinery and construction machinery, it is often necessary to lift and lower heavy objects, such as the lifting mechanism of the crane, the luffing of the boom, the boom of the loader, the lifting mechanism of the tractor, etc. It is necessary to lock the weight or oil cylinder or piston in a certain position, and at the same time, to achieve a smooth descent during the descent. The usual solution is to use a balance valve. However, the structure of the balance valve is relatively complicated, and the manufacturing cost is high, and it is often used in a hydraulic system with a large flow. The existing pilot-operated hydraulic locks have a complex structure and are mostly controlled by hydraulic pressure. The opening and closing of the control hydra...

AI Technical Summary

Problems solved by technology

The usual solution is to use a balance valve. However, the structure of the balance valve is complex and the manufacturing cost is high. It is often used in hydraulic systems with large flows.

The existing pilot-operated hydraulic locks are complex in structure, and mostly adopt hydraulic control. The opening and closing of the control hydraulic locks are all controlled by hydraulic pressure, and there is a defect that the opening or closing of the pilot-operated hydraulic locks is not sensitive.

The pilot cone spool in the existing pilot-operated hydraulic lock is pushed by the piston rod of the oil cylinder to open the pilot cone spool, that is, to install the oil cylinder to the opposite position of the hydraulic lock. Although the pilot cone spool can be opened, if the oil cylinder position When there is a change, that is, when the piston rod is eccentric, the piston rod will not press against the pilot cone spool at all, but will press against the spool, which will eventually cause the pilot hydraulic lock to fail to open, posing a greater safety hazard

In addition, even if the piston rod is not on the same straight line as the pilot poppet spool, it will inevitably cause the pilot poppet spool to be eccentric, eventually causing the pilot poppet spool to bend, and there is also a big safety hazard

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