A pilot-operated hydraulic control stop valve

Abstract

The invention relates to a pilot-operated hydraulic control cut-off valve, which is characterized in that it comprises a valve body, on which a third oil port and a fourth oil port are opened; a valve seat, on which a first oil port, a second oil port port; the first bushing, the second bushing and the spool, the spool divides the inner chamber of the second bushing into the oil chamber and the control chamber, the left and right sliding of the spool can open and close the first oil port, and the second oil port in the spool A flow hole, the first spring is provided in the oil return chamber; the first bush is in the shape of a stepped shaft, and a balance chamber is formed at the right end of the thin shaft part of the first bush; a second flow hole is opened on the first bush , the third flow hole, the left and right sliding of the valve core can open and close the first oil port; the side wall of the second bushing has a first damping hole and a second damping hole; The pilot valve assembly, whether the pilot valve assembly is opened or not determines whether the third oil port communicates with the second flow hole. The invention has the advantages of simple and reasonable structure, low manufacturing cost, reliable cut-off, compact volume and small impact.

Description

Technical field [0001] The present invention relates to a shut-off valve, and more particularly to a pilot liquid-controlled shutoff valve. Background technique [0002] The shutoff valve is also called the interception, which is the most widely used valve, mainly for truncation or to turn on various fluid media. At present, the shut-off valve products in the market generally perform open and closes in manual, electric, pneumatic driving. The manual shutoff valve is generally high, up to 100MPa, but its operation requires manual implementation, so it has certain limitations And the electric or pneumatic shut-off valve can be remote remotely, but due to the size and power limit by the drive element, the working pressure is generally not high, up to 40MPa. In recent years, there have been a liquid-controlled shut-off valve in the market, which can achieve long-distance operation, high pressure applications, but most of the existing hydraulic shut-off valves are direct structures, t...

AI Technical Summary

Problems solved by technology

At present, the stop valve products on the market generally adopt manual, electric and pneumatic driving methods to open and close. The manual stop valve generally has a high pressure, up to 100MPa, but its operation needs to be performed manually on site, so its use has certain limitations. ; Although electric or pneumatic globe valves can be operated remotely, due to the size and power limitations of the drive components, their working pressure is generally not high, up to 40MPa

In recent years, hydraulically controlled globe valves have appeared on the market, which can realize long-distance operation and high-pressure applications, but most of the existing hydraulically controlled globe valves are direct-acting structures, that is, the hydraulic control pressure acts on the globe valve core directly and controls Compared with the closing spring of the shut-off spool, this direct-acting structure is suitable for applications where the flow rate is not particularly large. In the case of large-flow applications, the diameter of the shut-off spool with the direct-acting structure is relatively large, and the action of the spring is required. The force is very large, so the designed spring specifications are very large, which increases the size of the globe valve as a whole, and because the force of the spring is large, when the hydraulic pressure unloading globe valve is closed, the globe valve core closes too quickly , On the one hand, it will cause a great impact, on the other hand, it will reduce the life of the globe valve

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