Spring auxiliary sealing structure of pressure balance type plug valve

Abstract

The utility model relates to the technical field of plug valves, and discloses a spring auxiliary sealing structure of a pressure balance type plug valve, which comprises a valve body, and a plug grease injection device is arranged on the valve body; the plug grease injection device comprises an injection valve, the injection valve is arranged at the top of a valve body, the left side of the injection valve is fixedly connected with an injection check valve, a screw fixedly penetrates through the top of the valve body, the bottom of the screw is fixedly connected with a gasket, a valve rod is arranged at the top of the valve body, and a thrust bearing is arranged at the bottom of the valve rod. A spring is fixedly connected to the bottom of the thrust bearing, a flat key is fixedly connected to the front face of the valve rod, a plug cock is fixedly connected to the bottom of the valve rod, sealing grease is injected into the valve body by rotating the injection valve, a balance ring is designed between the plug cock and the valve rod, and the balance ring slightly slides between the valve rod and the plug cock in the valve opening and closing process. And the axes of the valve rod and the plug cock are aligned, so that the operating force is better transmitted, the operating torque is reduced, and the plug cock and the valve body are more tightly sealed.

Description

Technical Field

[0001] The utility model relates to the technical field of plug valves, in particular to a spring-assisted sealing structure of a pressure-balanced plug valve. Background Art

[0002] The plug valve is a rotary valve in the shape of a closing piece or a plunger. It is a valve that can be opened or closed by rotating 90 degrees to connect or separate the channel opening on the valve plug with the channel opening on the valve body.

[0003] According to the Chinese patent publication number CN219035613U, the technical solution disclosed in the patent document is as follows: The utility model relates to a plug valve, including a valve body, a valve core assembly, a valve stem, a protective sleeve and a plug cover; the valve stem includes: a drive shaft and a mounting shaft; the drive shaft and the mounting shaft are integrally formed; the valve core assembly is installed to the mounting shaft; the mounting shaft is located in the protective sleeve; the valve body includes: a main body and a neck for guiding the rotation of the drive shaft; the main body and the neck are integrally formed; a plug valve, further including: a plane conflict piece; the plane conflict piece is installed to the bottom of the mounting shaft; the bottom surface of the plane conflict piece and the top surface of the plug cover are both planes; the plane conflict piece and the plug cover are abutted by the bottom surface of the plane conflict piece and the top surface of the plug cover. The utility model is beneficial in that by increasing the neck size, the valve stem is positioned on one side, and the plane conflict piece installed on the valve stem is only axially limited and does not participate in radial positioning. Reduce the problems affecting the installation and use of the valve stem caused by the assembly error of the parts.

[0004] The above patent has the following shortcomings: when the plug valve is opened for discharge, the plug will move downward away from the valve body. If the valve cover is deformed downward due to pressure, resulting in a large downward movement of the plug and a large gap between the plug and the valve body, a large amount of sealing grease will be blown out each time the plug is discharged, which may fail to meet the requirement of grease injection once every 5 times in the 70 switch tests in the "Plug Valve Factory Test Outline". In view of this, we propose a spring-assisted sealing structure for a pressure-balanced plug valve. Utility Model Content

[0005] 1. Technical issues to be resolved

[0006] In view of the deficiencies in the prior art, the utility model provides a spring-assisted sealing structure for a pressure-balanced plug valve.

[0007] (II) Technical solution

[0008] To achieve the above-mentioned purpose, the utility model provides the following technical solutions: a spring-assisted sealing structure of a pressure-balanced plug valve, comprising a valve body, on which a plug grease injection device is provided; the plug grease injection device comprises an injection valve, which is arranged on the top of the valve body, an injection check valve is fixedly connected to the left side of the injection valve, a screw is fixedly passed through the top of the valve body, a gasket is fixedly connected to the bottom of the screw, a valve stem is arranged on the top of the valve body, a thrust bearing is arranged at the bottom of the valve stem, a spring is fixedly connected to the bottom of the thrust bearing, and the valve stem The front side is fixedly connected with a flat key, and the bottom of the valve stem is fixedly connected with a plug. The position support block of the plug adopts a spherical structure with strong wear resistance. The contact surfaces are all welded with hard alloy to improve the hardness and service life. The end face of the adjustment screw is an arc surface, and the surface is high-frequency quenching hardened to reduce friction and facilitate adjustment. The flow channel area of ​​the plug is about 60% of the area of ​​the pipes at both ends. Two vents are opened at the bottom of the plug and threaded. It also has the function of hoisting the plug valve. The upper part of the plug uses a reverse check valve assembly instead of steel balls and spring parts. The standard mold The block design is more advanced. Stainless steel sheet + carbon steel sheet isolates the pressure, prevents leakage, avoids rust, and improves the pressure boundary strength. An adjustment block is added in the middle. The inclined surface design avoids excessive local shear force on the thin steel sheet when it is deformed. The valve body adopts a structure combining an overall spherical shape and a bell shape, without reinforcing ribs, which is convenient for radiographic inspection. The spherical shell also improves the rigidity of the shell and reduces the pressure deformation of the valve cavity. The upper flange and the valve body adopt a split structure, which is fastened and anti-rotated with bolts and positioning pins. The surface of the plug is provided with Special asymmetric oil groove, when the plug is turned, the sealing grease is automatically filled without leakage, ensuring the integrity of the oil film and reliable sealing. This asymmetric oil groove design has very small grease loss, which extends the grease filling time and service life. The conical seal makes the sealing contact area large, the oil film lubricates, and the service life is long. A large spring is arranged between the plug and the valve stem. In addition to the function of conductive connection between the plug and the valve body, it can effectively align the plug to ensure that the initial gap between it and the sealing surface of the valve body is uniform, and ensure that the contact stress between the plug and the valve body is relatively uniform, thereby effectively improving the sealing performance of the whole machine.

[0009] Preferably, an upper flange is provided on the top of the valve body.

[0010] Preferably, bolts are installed on the top of the upper flange.

[0011] Preferably, a cavity is provided inside the valve body.

[0012] Preferably, a screw cap device is provided on the valve body, and the screw cap device includes a valve cover. The valve cover adopts a forged flat valve cover, which is connected by bolts and sealed with a winding gasket. The valve cover is arranged at the bottom of the valve body, and an adjusting screw is threaded through the middle part of the valve cover, and a screw sleeve is provided on the outer wall of the adjusting screw.

[0013] Preferably, an adjusting block is arranged on the top of the adjusting screw, and a supporting block is arranged on the top of the adjusting block.

[0014] (III) Beneficial effects

[0015] Compared with the prior art, the utility model provides a spring-assisted sealing structure of a pressure-balanced plug valve, which has the following beneficial effects:

[0016] 1. The spring-assisted sealing structure of this pressure-balanced plug valve injects sealing grease into the valve body through a rotating injection valve. A balancing ring is designed between the plug and the valve stem. The balancing ring slides slightly between the valve stem and the plug during the valve switching process to align the axis of the valve stem and the plug, better transmit the operating force, reduce the operating torque, and ensure a tighter seal between the plug and the valve body.

[0017] 2. The spring-assisted sealing structure of the pressure-balanced plug valve connects the valve cover through an adjusting screw and is sealed with a spiral wound gasket, which is safe and reliable. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0019] Figure 1 It is a schematic diagram of the overall structure of the utility model;

[0020] Figure 2 This is a front sectional structural schematic diagram of the utility model;

[0021] Figure 3 This is a schematic diagram of the right side cross-sectional structure of the injection valve of the utility model;

[0022] Figure 4 It is a schematic diagram of the right side cross-sectional structure of the screw of the utility model.

[0023] In the figure: 1. valve body; 2. plug grease injection device; 21. injection valve; 22. injection check valve; 23. screw; 24. gasket; 25. valve stem; 26. spring; 27. flat key; 28. plug; 29. ​​upper flange; 210. cavity; 3. screw cover; 31. adjusting screw; 32. screw sleeve; 33. adjusting block; 34. support block; 35. valve cover. DETAILED DESCRIPTION

[0024] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments.

[0025] Example 1

[0026] like Figure 1-4 As shown, the utility model provides a spring-assisted sealing structure of a pressure-balanced plug valve, including a valve body 1, on which a plug grease injection device 2 is provided; the plug grease injection device 2 includes an injection valve 21, which is provided at the top of the valve body 1, and an injection check valve 22 is fixedly connected to the left side of the injection valve 21, a screw 23 is fixedly passed through the top of the valve body 1, and a gasket 24 is fixedly connected to the bottom of the screw 23, a valve stem 25 is provided at the top of the valve body 1, a thrust bearing is provided at the bottom of the valve stem 25, a spring 26 is fixedly connected to the bottom of the thrust bearing, and a flat key is fixedly connected to the front of the valve stem 25 27. The bottom of the valve stem 25 is fixedly connected with a plug 28. The position support block 34 of the plug 28 adopts a spherical structure with strong wear resistance. The contact surfaces are all welded with hard alloy to improve hardness and service life. The end face of the adjustment screw is an arc surface, and the surface is hardened by high-frequency quenching to reduce friction and facilitate adjustment. The flow channel area of ​​the plug 28 is about 60% of the area of ​​the pipes at both ends. Two vents are opened at the bottom of the plug 28, and threads are processed. At the same time, it has the function of hoisting the plug valve. The upper part of the plug 28 uses a reverse check valve assembly instead of steel balls and spring parts. Standard modular design The stainless steel sheet + carbon steel sheet isolates the pressure, prevents leakage, avoids rust, and improves the pressure boundary strength. An adjustment block 33 is added in the middle. The inclined surface design avoids excessive local shear force on the thin steel sheet when it is deformed. The valve body 1 adopts a structure combining an overall spherical shape and a bell shape, without reinforcing ribs, which is convenient for radiographic inspection. The spherical shell also improves the rigidity of the shell and reduces the pressure deformation of the valve cavity. The upper flange 29 and the valve body 1 adopt a split structure, which is fastened and anti-rotated with bolts and positioning pins. A special asymmetric oil Groove, when the plug 28 is turned, the sealing grease is automatically filled without leakage, ensuring the integrity of the oil film and reliable sealing. This asymmetric oil groove design has very little grease loss, which extends the grease filling time and service life. The conical seal makes the sealing contact area large, the oil film lubricates, and the service life is long. A large spring is arranged between the plug 28 and the valve stem 25. In addition to the function of conductively connecting the plug 28 and the valve body 1, it can also effectively align the plug 28 to ensure that the initial gap between it and the sealing surface of the valve body 1 is uniform, and ensure that the contact stress between the plug 28 and the valve body 1 is relatively uniform, thereby effectively improving the sealing performance of the whole machine.

[0027] An upper flange 29 is provided on the top of the valve body 1 .

[0028] Bolts are installed on the top of the upper flange 29.

[0029] A cavity 210 is provided inside the valve body 1 .

[0030] In this embodiment, sealing grease is injected into the valve body 1 by rotating the injection valve 21. A balancing ring is designed between the plug 28 and the valve stem 25. The balancing ring slides slightly between the valve stem 25 and the plug 28 during the valve switching process to align the axis of the valve stem 25 and the plug 28, better transmit the operating force, reduce the operating torque, and ensure a tighter seal between the plug 28 and the valve body 1.

[0031] Example 2

[0032] like Figure 1-2 As shown, on the basis of Example 1, the utility model provides a technical solution: a screw cap device 3 is arranged on the valve body 1, and the screw cap device 3 includes a valve cover 35. The valve cover 35 adopts a forged flat valve cover, which is bolted and sealed with a winding gasket. The valve cover 35 is arranged at the bottom of the valve body 1, and an adjusting screw 31 is threaded through the middle part of the valve cover 35, and a screw sleeve 32 is provided on the outer wall of the adjusting screw 31.

[0033] An adjusting block 33 is disposed on the top of the adjusting screw rod 31 , and a supporting block 34 is disposed on the top of the adjusting block 33 .

[0034] In this embodiment, the valve cover 35 is connected by adjusting the screw rod 31 and the wound gasket is sealed, which is safe and reliable.

[0035] The working principle of the spring-assisted sealing structure of the pressure-balanced plug valve is described in detail below.

[0036] like Figure 1-4 As shown, when in use, the sealing grease is injected into the valve body 1 by rotating the injection valve 21. A balancing ring is designed between the plug 28 and the valve stem 25. The balancing ring slides slightly between the valve stem 25 and the plug 28 during the valve switching process to align the axis of the valve stem 25 and the plug 28, better transmit the operating force, reduce the operating torque, and ensure that the plug 28 and the valve body 1 are more tightly sealed. The valve cover 35 is connected by adjusting the screw 31 and the wound gasket is sealed, which is safe and reliable.

Claims

1. A spring-assisted sealing structure for a pressure-balanced plug valve, comprising a valve body (1), characterized in that: The valve body (1) is provided with a cock grease injection device (2); The plug grease injection device (2) comprises an injection valve (21), the injection valve (21) is arranged on the top of the valve body (1), an injection check valve (22) is fixedly connected to the left side of the injection valve (21), a screw (23) is fixedly passed through the top of the valve body (1), a gasket (24) is fixedly connected to the bottom of the screw (23), a valve stem (25) is arranged on the top of the valve body (1), a thrust bearing is arranged at the bottom of the valve stem (25), a spring (26) is fixedly connected to the bottom of the thrust bearing, a flat key (27) is fixedly connected to the front of the valve stem (25), and a plug (28) is fixedly connected to the bottom of the valve stem (25).

2. The spring-assisted sealing structure of a pressure-balanced plug valve according to claim 1, characterized in that: An upper flange (29) is provided on the top of the valve body (1).

3. The spring-assisted sealing structure of a pressure-balanced plug valve according to claim 2, characterized in that: Bolts are installed on the top of the upper flange (29).

4. The spring-assisted sealing structure of a pressure-balanced plug valve according to claim 1, characterized in that: A cavity (210) is provided inside the valve body (1).

5. The spring-assisted sealing structure of a pressure-balanced plug valve according to claim 1, characterized in that: The valve body (1) is provided with a screw cap device (3), the screw cap device (3) comprising a valve cover (35), the valve cover (35) being arranged at the bottom of the valve body (1), an adjusting screw rod (31) being threadedly penetrated through the middle of the valve cover (35), and a screw rod sleeve (32) being sleeved on the outer wall of the adjusting screw rod (31).

6. The spring-assisted sealing structure of a pressure-balanced plug valve according to claim 5, characterized in that: An adjusting block (33) is arranged on the top of the adjusting screw rod (31), and a supporting block (34) is arranged on the top of the adjusting block (33).

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