Plug-in type balance valve

Abstract

The invention relates to a plug-in type balance valve which comprises a valve body, a one-way valve core and a balance valve core, wherein a first oil opening, a second oil opening and a third oil opening are arranged on the valve body; the one-way valve core is arranged at the second oil opening and pushed by a first spring to maintain the trend of axial upward shift; the balance valve core is installed in the valve body and can be matched with a valve opening of the one-way valve core, and a second spring is arranged in a spring cavity of the valve body; the upper part in the balance valve core is provided with an axial passage and a first damping hole; the middle position of the balance valve core is provided with an axial convex shoulder; an annular notch is arranged on the periphery surface of the axial convex shoulder; the inner wall of the valve body is provided with an annular inner shoulder blade; an oil inlet cavity is formed among the annular notch, the inner wall of the valve body and the annular inner shoulder blade; and the third oil opening is communicated with the oil inlet cavity by a second damping hole on the side wall of the valve wall. The balance valve core and the one-way valve core are in an integral structure, and the structure is simple; the balance valve core and the one-way valve core are relatively independent on the relative position relationship, the assembly is convenient, and the requirements on heat treatment and materials of the balance valve core are lowered.

Description

technical field [0001] The invention belongs to the technical field of valves, in particular to a plug-in balance valve suitable for a telescopic oil cylinder circuit of a boom of a heavy lifting machine. Background technique [0002] In modern construction machinery, construction machinery and other mechanical equipment, a large number of lifting hydraulic circuits are used. Among them, the balance valve is the key hydraulic component of this type of system. The performance of the balance valve directly affects the performance of the main engine. Existing balance valves are divided into plate balance valves and cartridge balance valves according to the connection mode. In order to reduce the installation space and improve system reliability in crane telescopic cylinders, cartridge balance valves are generally used. [0003] Such as a Chinese invention patent "A Balance Valve" with the patent No. ZL01139273.8 (announcement number CN1133821C) discloses such a balance valve, w...

AI Technical Summary

Problems solved by technology

[0005] 1. The structure is complex, the coaxiality between the parts requires as many as six places, and the gap between the sliding fits is extremely small, the process is difficult to manufacture, and the valve core is easy to get stuck when the product is actually used, which seriously affects the reliability of the main engine

[0006] 2. Since the pilot spool (one-way spool) is located inside the main spool (balance spool), and the balance spool is wired to the valve sleeve, this puts forward high requirements for the heat treatment and material of the balance spool. On the one hand, the taper surface of the balance valve core must have a high hardness, on the other hand, the hardness of the joint between the balance valve core and the one-way valve core should be lower, which will undoubtedly increase the processing cost

[0007] 3. Since the one-way valve core is located inside the balance valve core, in order to reduce the flow resistance, the size of the one-way valve core must be increased, and the size of the balance valve core and valve sleeve will also increase successively, making the overall size of the valve larger , which makes it difficult to process the insertion hole

[0008] 4. The upper and lower diameters of the valve sleeve are consistent, and the sealing ring may be easily damaged during installation, resulting in internal leakage and causing hidden dangers to the safety of the main engine

[0009] 5. There are few internal damping links in the valve, and the stability is poor under the interference of external conditions, which is prone to jitter

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