Sealing structure of stop valve

Abstract

The utility model discloses a stop valve sealing structure which comprises a valve body, a mounting hole, a liquid inlet hole and a liquid outlet hole which are communicated with one another are formed in the top and the two ends of the valve body respectively, a valve cover is mounted at the upper end of the mounting hole, a valve rod is arranged on the valve cover, the valve rod penetrates through the valve cover and extends into the valve body, and the liquid inlet hole is communicated with the liquid outlet hole. An external thread is arranged on the upper portion of a rod body of the valve rod, a connecting disc is connected to the valve rod in a threaded mode, the connecting disc is fixedly connected with the valve deck through a plurality of screws, a sealing cylinder is arranged at the joint of the liquid inlet hole and the liquid outlet hole and is coaxial with the valve rod, and a sealing assembly is arranged at the lower end of the valve rod. The sealing assembly comprises a first valve element and a second valve element, the first valve element and the second valve element can be matched with the sealing cylinder to form double sealing structures with different properties, and the sealing performance of the sealing assembly and the applicability to different circulating media are improved.

Description

Technical Field

[0001] The utility model relates to the technical field of stop valves, in particular to a stop valve sealing structure. Background Art

[0002] Globe valves are key devices used to control fluid flow and are widely used in petroleum, chemical, electric power, water supply and other industrial fields.

[0003] The Chinese patent publication number CN203604668U discloses a sealing structure for a stop valve to prevent internal leakage. The structure achieves sealing by pressing the sealing rubber ring on the sealing seat by the valve core to prevent internal leakage of the stop valve. The sealing structure of this structure is relatively simple, and the sealing rubber ring is located in the position where the medium flows through. Long-term use may cause corrosion by the impact of the medium, resulting in damage to the sealing structure and affecting the sealing effect.

[0004] Therefore, it is necessary to provide a stop valve sealing structure to solve the problems mentioned in the above background technology. Utility Model Content

[0005] To achieve the above-mentioned purpose, the present invention provides the following technical solution: a stop valve sealing structure, comprising: a valve body, wherein the top and both ends of the valve body are respectively provided with a connecting mounting hole, a liquid inlet hole and a liquid outlet hole, a valve cover is installed on the upper end of the mounting hole, a valve stem is provided on the valve cover, the valve stem passes through the valve cover and extends into the interior of the valve body, an external thread is provided on the upper part of the valve stem, and a connecting disk is screwed on the valve stem, and the connecting disk is fixedly connected to the valve cover by a plurality of screws, characterized in that a sealing cylinder is coaxially provided with the valve stem at the junction of the liquid inlet hole and the liquid outlet hole, a sealing assembly is provided at the lower end of the valve stem, the sealing assembly comprises a first valve core and a second valve core, and the first valve core and the second valve core can cooperate with the sealing cylinder to form a first sealing structure and a second sealing structure respectively;

[0006] Among them, the first valve core is a pressure-driven flexible sealing structure, and the second valve core is a pressure-driven rigid sealing structure. When the sealing pressure is released, the flexible sealing part of the first valve core can automatically retract and give way, reducing the impact of medium circulation on the flexible sealing part.

[0007] Preferably, a stepped hole is coaxially opened downward at the upper end of the sealing cylinder, and the side wall of the stepped hole cooperates with the first valve core to form a first sealing structure. A sealing chamfer is set at the upper end of the stepped hole, and the sealing chamfer cooperates with the second valve core to form a second sealing structure.

[0008] Preferably, the first valve core is coaxially fixed to the lower end of the valve stem, and a ring groove is provided in the middle of the circumference of the first valve core. Several sealing rings are slidably sleeved in the ring groove, and elastic sealing rings are provided between each of the sealing rings.

[0009] Preferably, the outer diameter of the sealing ring is larger than the inner diameter of the sealing cylinder and smaller than the inner diameter of the stepped hole, and the outer diameter of the first valve core is smaller than the inner diameter of the sealing cylinder.

[0010] Preferably, a fixed ring plate is spaced apart at one end of the valve stem body close to the first valve core, the second valve core is slidingly arranged between the fixed ring plate and the first valve core, the second valve core and the fixed ring plate are elastically connected by a spring, and a sealing surface is provided at the lower end of the circumferential side of the second valve core to match the sealing chamfer.

[0011] Preferably, a bellows is coaxially provided on the outer side of the spring, and two ends of the bellows are respectively connected to the fixed ring plate and the second valve core.

[0012] Preferably, a relief hole is provided at the lower end of the valve cover, and the inner diameter of the relief hole is larger than the outer diameters of the bellows and the fixed ring plate.

[0013] Compared with the prior art, the present invention provides a stop valve sealing structure with the following beneficial effects:

[0014] In the utility model, a double sealing structure with different properties is formed by cooperating with the sealing component and the sealing cylinder, thereby improving the sealing performance of the sealing component and the applicability to different circulating media; at the same time, by arranging a sealing ring and an elastic sealing ring on the first valve core, a sealing structure is formed between the sealing ring and the sealing cylinder by squeezing the elastic sealing ring to deform. When in a non-sealed state, the elastic sealing ring can automatically retract, reducing the impact on the elastic sealing ring when the medium circulates, and increasing the service life of the elastic sealing ring. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 This is a schematic diagram of the overall structure of a stop valve sealing structure;

[0016] Figure 2 for Figure 1 A in the middle is an enlarged structural diagram;

[0017] Figure 3 This is a schematic diagram of the partial structure of a sealing cylinder and valve core assembly of a stop valve sealing structure;

[0018] Figure 4 This is a schematic diagram of the medium flow structure of a stop valve sealing structure;

[0019] In the figure: 1. Valve body; 2. Valve cover; 3. Valve stem; 4. Handwheel; 5. Connecting plate; 6. Screw; 7. Sealing cylinder; 8. Sealing assembly; 9. First valve core; 10. Ring groove; 11. Sealing ring; 12. Elastic sealing ring; 13. Second valve core; 14. Fixed ring plate; 15. Spring; 16. Bellows; 17. Step hole; 18. Sealing chamfer; 19. Avoidance hole. DETAILED DESCRIPTION

[0020] See also Figure 1-4 The utility model provides a stop valve sealing structure, comprising: a valve body 1, wherein the top and both ends of the valve body 1 are respectively provided with a mounting hole, a liquid inlet hole and a liquid outlet hole which are connected to each other, a valve cover 2 is installed on the upper end of the mounting hole, a valve stem 3 is provided on the valve cover 2, the valve stem 3 passes through the valve cover 2 and extends into the interior of the valve body 1, an external thread is provided on the upper part of the stem 3, and a connecting disk 5 is screwed on the stem 3, the connecting disk 5 is fixedly connected to the valve cover 2 by a plurality of screws 6, a sealing cylinder 7 is coaxially provided with the valve stem 3 at the junction of the liquid inlet hole and the liquid outlet hole, a sealing assembly 8 is provided at the lower end of the valve stem 3, the sealing assembly 8 comprises a first valve core 9 and a second valve core 13, the first valve core 9 and the second valve core 13 can cooperate with the sealing cylinder 7 to form a first sealing structure and a second sealing structure respectively;

[0021] Among them, the first valve core 9 is a pressure-driven flexible sealing structure, and the second valve core 13 is a pressure-driven rigid sealing structure. When the sealing pressure is released, the flexible sealing part of the first valve core 9 can automatically retract and give way, reducing the impact of the medium circulation on the flexible sealing part.

[0022] It needs to be explained that when it is necessary to block the circulating medium in the valve body 1, the valve stem 3 is rotated to drive the sealing assembly 8 to move downward, and the first valve core 9 and the second valve core 13 of the sealing assembly 8 cooperate with the sealing tube 7 to form a double sealing structure, thereby improving the sealing performance of the sealing assembly 8; at the same time, the first valve core 9 and the second valve core 13 respectively adopt flexible sealing and rigid sealing structures, thereby improving the sealing performance of the sealing assembly 8 and its applicability to different circulating media.

[0023] Preferably, a handwheel 4 is installed on the outer end of the valve stem 3.

[0024] Furthermore, a stepped hole 17 is coaxially opened downward at the upper end of the sealing cylinder 7, and the side wall of the stepped hole 17 cooperates with the first valve core 9 to form a first sealing structure. A sealing chamfer 18 is provided at the upper end of the stepped hole 17, and the sealing chamfer 18 cooperates with the second valve core 13 to form a second sealing structure.

[0025] Furthermore, the first valve core 9 is coaxially fixed to the lower end of the valve stem 3, and a ring groove 10 is opened in the middle of the circumference of the first valve core 9. A plurality of sealing rings 11 are slidably sleeved in the ring groove 10, and elastic sealing rings 12 are provided between each of the sealing rings 11.

[0026] Furthermore, the outer diameter of the sealing ring 11 is larger than the inner diameter of the sealing cylinder 7 and smaller than the inner diameter of the stepped hole 17 , and the outer diameter of the first valve core 9 is smaller than the inner diameter of the sealing cylinder 7 .

[0027] It should be explained that when the medium flowing in the valve body 1 is blocked, the valve stem 3 is rotated to drive the first valve core 9 to move downward continuously, the sealing ring 11 contacts the lower end surface of the stepped hole 17, and squeezes the elastic sealing ring 12 between each sealing ring 11, causing the elastic sealing ring 12 to be radially deformed by the squeezing, protruding from the outer surface of the sealing ring 11. The elastic sealing ring 12 contacts the side wall of the stepped hole 17 to form a first sealing structure. When the medium needs to flow, the valve stem 3 is rotated in the opposite direction, driving the sealing assembly 8 to move upward, and the medium flows through the sealing cylinder 7. The sealing ring 11 no longer bears the pressure of the valve stem 3. Under the elastic force of the elastic sealing ring 12, the spacing between the sealing rings 11 is adaptively adjusted, and the elastic sealing ring 12 is retracted between the sealing rings 11, lower than the outer surface of each sealing ring 11, reducing the impact on the elastic sealing ring 12 during the medium circulation and increasing its service life.

[0028] Preferably, the longitudinal cross-section of the sealing ring 11 is a rectangular structure.

[0029] Furthermore, a fixed ring plate 14 is interposed at one end of the stem of the valve stem 3 close to the first valve core 9, and the second valve core 13 is slidingly arranged between the fixed ring plate 14 and the first valve core 9. The second valve core 13 and the fixed ring plate 14 are elastically connected by a spring 15, and a sealing surface is adapted to be provided on the lower end of the circumferential side of the second valve core 13 and the sealing chamfer 18.

[0030] It needs to be explained that when the rotating valve stem 3 drives the first valve core 9 to move downward, the sealing surface of the second valve core 13 first cooperates with the sealing chamfer 18 under the elastic support of the spring 15 to form a second sealing structure. After the second sealing structure is sealed, as the valve stem 3 continues to move downward, the spring 15 is compressed and the first valve core 9 continues to move downward, so that the elastic sealing ring 12 is squeezed by the sealing ring 11 and radially deformed, forming a first sealing structure, and then forming a double sealing structure with different properties.

[0031] Preferably, in the initial state, the elastic coefficient of the spring 15 satisfies that when supporting the second valve core 13 , the second valve core 13 can cooperate with the sealing chamfer 18 to form a second sealing structure.

[0032] Furthermore, a bellows 16 is coaxially arranged on the outside of the spring 15, and the two ends of the bellows 16 are respectively connected to the fixed ring plate 14 and the second valve core 13. The bellows 16 is provided to separate the spring 15 from the medium flowing in the valve body 1, thereby preventing the spring 15 from being damaged by the medium.

[0033] Furthermore, a relief hole 19 is provided at the lower end of the valve cover 2. The inner diameter of the relief hole 19 is larger than the outer diameters of the bellows 16 and the fixed ring plate 14. The provision of the relief hole 19 increases the upper limit of the sealing assembly 8, ensuring the flow of the medium while reducing the impact corrosion of the medium on the sealing assembly 8.

[0034] During specific implementation, the valve stem is rotated to drive the sealing assembly to move downward. The sealing surface of the second valve core first cooperates with the sealing chamfer under the elastic support of the spring to form a second sealing structure. After the second sealing structure is sealed, as the valve stem continues to move downward, the spring is compressed and the first valve core continues to move downward, causing the elastic sealing ring to be radially deformed by the squeezing of the sealing ring, forming a first sealing structure, and then forming a double sealing structure with different properties, thereby improving the sealing performance of the sealing assembly and its applicability to the circulating medium.

[0035] The above is only a preferred specific implementation method of the present invention, but the protection scope of the present invention is not limited to this. Any technician familiar with the technical field within the technical scope disclosed by the present invention can make equivalent replacements or changes based on the technical solution and utility model concept of the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A stop valve sealing structure, comprising: A valve body (1), wherein the top and both ends of the valve body (1) are respectively provided with a mounting hole, a liquid inlet hole and a liquid outlet hole which are connected to each other, a valve cover (2) is installed on the upper end of the mounting hole, a valve stem (3) is provided on the valve cover (2), the valve stem (3) passes through the valve cover (2) and extends into the interior of the valve body (1), an external thread is provided on the upper part of the stem of the valve stem (3), and a connecting disk (5) is screwed on the valve stem (3), and the connecting disk (5) is fixedly connected to the valve cover (2) through a plurality of screws (6), characterized in that a sealing cylinder (7) is coaxially provided at the junction of the liquid inlet hole and the liquid outlet hole and the valve stem (3), a sealing assembly (8) is provided at the lower end of the valve stem (3), and the sealing assembly (8) includes a first valve core (9) and a second valve core (13), and the first valve core (9) and the second valve core (13) can cooperate with the sealing cylinder (7) to form a first sealing structure and a second sealing structure respectively; The first valve core (9) is a pressure-driven flexible sealing structure, and the second valve core (13) is a pressure-driven rigid sealing structure. When the sealing pressure is released, the flexible sealing portion of the first valve core (9) can automatically retract and give way, thereby reducing the impact of medium circulation on the flexible sealing portion.

2. A stop valve sealing structure according to claim 1, characterized in that: A stepped hole (17) is coaxially opened downward at the upper end of the sealing cylinder (7), and the side wall of the stepped hole (17) cooperates with the first valve core (9) to form a first sealing structure. A sealing chamfer (18) is provided at the upper end of the stepped hole (17), and the sealing chamfer (18) cooperates with the second valve core (13) to form a second sealing structure.

3. A stop valve sealing structure according to claim 2, characterized in that: The first valve core (9) is coaxially fixed to the lower end of the valve stem (3), and a ring groove (10) is provided in the middle of the circumference of the first valve core (9). A plurality of sealing rings (11) are slidably sleeved in the ring groove (10), and elastic sealing rings (12) are provided between each of the sealing rings (11).

4. A stop valve sealing structure according to claim 3, characterized in that: The outer diameter of the sealing ring (11) is larger than the inner diameter of the sealing cylinder (7) and smaller than the inner diameter of the stepped hole (17); the outer diameter of the first valve core (9) is smaller than the inner diameter of the sealing cylinder (7).

5. A stop valve sealing structure according to claim 2, characterized in that: A fixed ring plate (14) is provided at one end of the stem of the valve stem (3) close to the first valve core (9), and the second valve core (13) is slidingly provided between the fixed ring plate (14) and the first valve core (9). The second valve core (13) and the fixed ring plate (14) are elastically connected by a spring (15), and a sealing surface is provided at the lower end of the peripheral side of the second valve core (13) and the sealing chamfer (18).

6. A stop valve sealing structure according to claim 5, characterized in that: A bellows (16) is coaxially arranged on the outside of the spring (15), and two ends of the bellows (16) are respectively connected to the fixed ring plate (14) and the second valve core (13).

7. A stop valve sealing structure according to claim 6, characterized in that: A relief hole (19) is provided at the lower end of the valve cover (2), and the inner diameter of the relief hole (19) is larger than the outer diameters of the bellows (16) and the fixed ring plate (14).

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