Normally closed pneumatic diaphragm valve

Abstract

The utility model relates to the technical field of pneumatic diaphragm valves, in particular to a normally-closed pneumatic diaphragm valve which comprises a valve body, a rectangular frame is fixedly installed at the top end of the valve body, a vertical high platform is fixedly connected to the top end of the rectangular frame, and a pneumatic executing mechanism is arranged at the upper end of the high platform. And the sleeve is transversely fixed in the lower portion of the right side of the rectangular frame, and an anti-retreating mechanism is arranged between the sleeve and the pneumatic executing mechanism. According to the utility model, through the cooperation of the pneumatic actuating mechanism and the anti-retreating mechanism, when the pneumatic actuating mechanism leaks gas, the positioning rod and the positioning block in the anti-retreating mechanism are kept in a mechanical locking state, so that the valve plate is effectively prevented from retreating accidentally, and the problem of medium leakage caused by gas leakage under a high-pressure working condition is solved; and the strict sealing performance of the pipeline is ensured.

Description

Technical Field

[0001] This utility model relates to the field of pneumatic diaphragm valve technology, specifically a normally closed pneumatic diaphragm valve. Background Technology

[0002] The diaphragm valve's opening and closing element is a diaphragm made of a soft material, which separates the valve body cavity from the valve cover cavity and drive components. This protects the valve stem, valve disc, and other parts located above the diaphragm from corrosion by the medium, eliminating the need for a packing seal and preventing media leakage. Therefore, diaphragm valves are widely used in various fields, enabling the control of highly corrosive, high-temperature, and high-purity media.

[0003] The pneumatic diaphragm valve disclosed in authorization announcement number CN217762182U includes a valve body, a cylinder with an inner cavity disposed within the valve body, a diaphragm, a valve stem, and a piston. The piston divides the inner cavity into an intake chamber and an exhaust chamber. A drive spring for driving the piston is provided in the exhaust chamber. A connecting channel formed in the cylinder for the valve stem to pass through is connected to the intake chamber. A mounting groove is formed between the connecting channel and the valve stem, and the mounting groove communicates with the intake chamber to form an installation port. The advantages of this utility model after adopting the above technical solution are: better sealing effect, applicability to high-pressure conditions, simple structure, and lower cost.

[0004] Although the aforementioned patent offers better sealing and is applicable to high-pressure conditions, when the pneumatic linear mechanism leaks gas, the valve retracts, opening the pipeline. In situations requiring strict sealing, this can lead to leakage of the medium inside the pipeline. Utility Model Content

[0005] The purpose of this invention is to provide a normally closed pneumatic diaphragm valve to solve the problems mentioned in the background art.

[0006] To achieve the above objectives, this utility model provides the following technical solution:

[0007] A normally closed pneumatic diaphragm valve, comprising

[0008] The valve body has a rectangular frame fixedly installed at its top, and a vertical platform is fixedly connected to the top of the rectangular frame. A pneumatic actuator is installed at the top of the platform.

[0009] A sleeve is horizontally fixed inside the lower right side of the rectangular frame, and an anti-reverse mechanism is provided between the sleeve and the pneumatic actuator.

[0010] Preferably, the pneumatic actuator includes a lower cover fixedly connected to the top of the platform, and an upper cover detachably installed on the upper end of the lower cover by bolts. A diaphragm is fixedly connected between the upper cover and the lower cover, and a fixing block is fixedly connected to the middle of the diaphragm.

[0011] Preferably, a valve seat is integrally formed in the middle of the inner side of the valve body, a vertical valve stem is fixedly connected to the middle of the bottom end of the fixing block, a valve plate is fixedly connected to one end of the valve stem inside the valve body, and a spring is elastically connected between the fixing block and the platform and outside the valve stem.

[0012] Preferably, a vertical limiting frame is fixedly connected to the inner left side of the rectangular frame. A guide groove is provided on the side of the limiting frame near the valve stem. A fixing sleeve is fixedly connected to the outside of one end of the rectangular frame where the valve stem is located. A horizontal pointer is fixedly connected to the left side of the fixing sleeve. The pointer is slidably connected to the guide groove. A scale is provided on the outside of the limiting frame.

[0013] Preferably, the anti-retraction mechanism includes a pipe 1 vertically connected to the middle of the top of the cover, and a reversing valve connected to the middle of the pipe 1. The other end of the reversing valve is connected to the sleeve through a pipe 2, and an electric valve is fixedly installed at the end of the pipe 2 near the sleeve. A positioning rod is movably sleeved inside the sleeve. A positioning block is fixedly connected to the right side of the fixed sleeve. A piston is fixedly installed at the end of the positioning rod away from the positioning block. A spring 2 is elastically connected between the piston and the left side of the sleeve and outside the positioning rod.

[0014] Preferably, sealing packing is fixedly installed inside both sides of the valve body and the rectangular frame.

[0015] Compared with the prior art, the beneficial effects of this utility model are:

[0016] This normally closed pneumatic diaphragm valve, through the coordinated operation of the pneumatic actuator and the anti-reverse mechanism, ensures that when gas leakage occurs in the pneumatic actuator, the positioning rod and positioning block in the anti-reverse mechanism remain mechanically locked, effectively preventing the valve plate from accidentally retracting. This solves the problem of medium leakage caused by gas leakage under high-pressure conditions and ensures the strict sealing of the pipeline. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the overall main structure of this utility model;

[0018] Figure 2 This is a schematic cross-sectional view of the overall structure of this utility model;

[0019] Figure 3 For the present utility model Figure 2 Enlarged view of point A in the middle;

[0020] Figure 4 For the present utility model Figure 2 Enlarged diagram of point B in the middle.

[0021] In the diagram: 1. Valve body; 2. Rectangular frame; 3. Platform; 4. Sleeve; 5. Lower cover; 6. Upper cover; 7. Diaphragm; 8. Fixing block; 9. Valve seat; 10. Valve stem; 11. Valve plate; 12. Spring 1; 13. Limiting bracket; 14. Guide groove; 15. Fixing sleeve; 16. Pointer; 17. Scale; 18. Pipe 1; 19. Directional valve; 20. Electric valve; 21. Positioning rod; 22. Positioning block; 23. Pipe 2; 24. Spring 2; 25. Sealing packing; 26. Pipe 2. Detailed Implementation

[0022] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0023] like Figure 1-4 As shown, this utility model provides a technical solution:

[0024] A normally closed pneumatic diaphragm valve includes a valve body 1 with a rectangular frame 2 fixedly mounted at its top. Sealing packing 25 is fixedly installed inside both sides of the valve body 1 and the rectangular frame 2. A vertical platform 3 is fixedly connected to the top of the rectangular frame 2. A pneumatic actuator is installed at the upper end of the platform 3. The pneumatic actuator includes a lower cover 5 fixedly connected to the top of the platform 3, and an upper cover 6 detachably mounted to the upper end of the lower cover 5 by bolts. A diaphragm 7 is fixedly connected between the upper cover 6 and the lower cover 5. A fixing block 8 is fixedly connected to the middle of the valve body 1. A valve seat 9 is integrally formed in the middle of the inner side of the valve body 1. A vertical valve stem 10 is fixedly connected to the middle of the bottom end of the fixing block 8. A valve plate 11 is fixedly connected to one end of the valve stem 10 inside the valve body 1. A spring 12 is elastically connected between the fixing block 8 and the platform 3 and outside the valve stem 10. A vertical limiting frame 13 is fixedly connected to the inner left side of the rectangular frame 2. A guide groove 14 is opened on the side of the limiting frame 13 near the valve stem 10. A valve stem 10 is fixedly connected to a fixed sleeve 15 at one end of the rectangular frame 2. A horizontal pointer 16 is fixedly connected to the left side of the fixed sleeve 15. The pointer 16 is slidably connected to the guide groove 14. A scale 17 is set on the outside of the limit frame 13. A sleeve 4 is horizontally fixed inside the lower right side of the rectangular frame 2. An anti-retraction mechanism is set between the sleeve 4 and the pneumatic actuator. The anti-retraction mechanism includes a pipe 18 that is vertically connected to the middle of the top of the upper cover 6, and a reversing valve 19 that is connected to the middle of the pipe 18. The other end of the reversing valve 19 is connected to the sleeve 4 through a pipe 26. An electric valve 20 is fixedly installed at the end of the pipe 26 near the sleeve 4. A positioning rod 21 is movably sleeved inside the sleeve 4. A positioning block 22 is fixedly connected to the right side of the fixed sleeve 15. A piston 23 is fixedly installed at the end of the positioning rod 21 away from the positioning block 22. A spring 24 is elastically connected between the piston 23 and the left side of the sleeve 4 and outside the positioning rod 21.

[0025] In this embodiment, through the coordinated operation of the pneumatic actuator and the anti-retraction mechanism, when the pneumatic actuator experiences gas leakage, the positioning rod 21 and the positioning block 22 in the anti-retraction mechanism remain mechanically locked, effectively preventing the valve plate 11 from accidentally retracting. This solves the problem of medium leakage caused by gas leakage under high-pressure conditions and ensures the strict sealing of the pipeline.

[0026] Working principle: In the initial state, compressed gas enters the air chamber between the upper cover 6 and the lower cover 5 through pipe 18, pushing the diaphragm 7 to deform downwards, causing the valve stem 10 and valve plate 11 to move downwards, so that the valve plate 11 is tightly attached to the valve seat 9. At this time, the reversing valve 19 keeps pipe 18 disconnected from pipe 26. When the valve is fully closed, the reversing valve 19 switches the passage to connect pipe 18 and pipe 26. At the same time, the electric valve 20 is opened to allow compressed gas to enter the sleeve 4 and push the piston 23 to the left, causing the positioning rod 21 to engage with the positioning block 22 to form a mechanical lock, and the electric valve 20 is closed. When it is necessary to open the valve, the electric valve 20 is opened to vent the gas in the sleeve 4, causing the spring 24 to push the piston 23 to the right to release the lock. Then, the reversing valve 19 is controlled to switch the passage to allow the gas in the upper cover 6 to be discharged through pipe 18. The spring 12 pushes the diaphragm 7 to reset, causing the valve plate 11 to leave the valve seat 9, thus opening the valve.

[0027] The foregoing has shown and described the basic principles, main features, and advantages of this utility model. Those skilled in the art should understand that this utility model is not limited to the above embodiments. The embodiments and descriptions in the specification are merely preferred examples and are not intended to limit the utility model. Various changes and modifications can be made to this utility model without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed utility model. The scope of protection of this utility model is defined by the appended claims and their equivalents.

Claims

1. A normally closed pneumatic diaphragm valve, characterized in that: include The valve body (1) has a rectangular frame (2) fixedly installed at its top. A vertical platform (3) is fixedly connected to the top of the rectangular frame (2). A pneumatic actuator is installed at the top of the platform (3). A sleeve (4) is horizontally fixed inside the right side of the rectangular frame (2). An anti-retraction mechanism is provided between the sleeve (4) and the pneumatic actuator. The anti-retraction mechanism includes a pipe (18) vertically connected to the middle of the top of the cover (6) and a reversing valve (19) connected to the middle of the pipe (18). The other end of the reversing valve (19) is connected to the sleeve (4) through a pipe (26). An electric valve (20) is fixedly installed at the end of the pipe (26) near the sleeve (4). A positioning rod (21) is movably sleeved inside the sleeve (4). A positioning block (22) is fixedly connected to the right side of the fixed sleeve (15). A piston (23) is fixedly installed at the end of the positioning rod (21) away from the positioning block (22). A spring (24) is elastically connected between the piston (23) and the left side of the sleeve (4) and outside the positioning rod (21).

2. The normally closed pneumatic diaphragm valve according to claim 1, characterized in that: The pneumatic actuator includes a lower cover (5) fixedly connected to the top of the platform (3), and an upper cover (6) detachably installed on the upper end of the lower cover (5) by bolts. A diaphragm (7) is fixedly connected between the upper cover (6) and the lower cover (5), and a fixing block (8) is fixedly connected to the middle of the diaphragm (7).

3. A normally closed pneumatic diaphragm valve according to claim 2, characterized in that: A valve seat (9) is integrally formed in the middle of the inner side of the valve body (1). A vertical valve stem (10) is fixedly connected to the middle of the bottom end of the fixing block (8). A valve plate (11) is fixedly connected to one end of the valve stem (10) inside the valve body (1). A spring (12) is elastically connected between the fixing block (8) and the platform (3) and outside the valve stem (10).

4. A normally closed pneumatic diaphragm valve according to claim 3, characterized in that: A vertical limiting frame (13) is fixedly connected to the inner left side of the rectangular frame (2). A guide groove (14) is provided on the side of the limiting frame (13) near the valve stem (10). A fixing sleeve (15) is fixedly connected to the outside of one end of the rectangular frame (2). A horizontal pointer (16) is fixedly connected to the left side of the fixing sleeve (15). The pointer (16) is slidably connected to the guide groove (14). A scale (17) is provided on the outside of the limiting frame (13).

5. A normally closed pneumatic diaphragm valve according to claim 1, characterized in that: Sealing packing (25) is fixedly installed inside both sides of the valve body (1) and the rectangular frame (2).

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