Pneumatic low-temperature regulating valve

Abstract

The invention relates to the technical field of adjusting valves, in particular to a pneumatic low-temperature adjusting valve which comprises a valve body, a valve seat is arranged in an inner cavity of the valve body, a valve rod is movably connected to the upper end of the inner cavity of the valve body in an inserted mode, a valve element is arranged at the lower end of the valve rod, and a pneumatic executing mechanism for adjusting opening and closing of the valve seat is installed above the valve body. The valve rod is sequentially sleeved with a valve cover, a connecting base and a sealing upper cover from bottom to top, a supporting frame is fixedly installed at the upper end of the sealing upper cover, the upper end of the supporting frame is fixedly connected with the lower end of a pneumatic executing mechanism, and a pneumatic lifting rod is installed at the lower end of the pneumatic executing mechanism in an up-down sliding mode. The hydraulic regulating valve has the beneficial effects that when the regulating valve needs to be closed, the pneumatic lifting rod moves downwards through the pneumatic executing mechanism, the valve rod drives the piston and the valve element to move downwards, and the fluid sealing element at the lower end of the valve element is connected with the circular cavity of the valve seat in a sealed and inserted mode; and when the piston slides downwards along the piston cavity, gas in the piston cavity is introduced into the first gas guide hole.

Description

Technical Field

[0001] The present invention relates to the technical field of regulating valves, and particularly to a pneumatic cryogenic regulating valve. Background Art

[0002] A pneumatic cryogenic regulating valve is a valve used to control the flow rate and pressure of fluids under cryogenic conditions. It uses a pneumatic actuator as a control device, and controls the opening of the valve by adjusting the working state of the actuator, thereby achieving the regulation of fluid flow rate and pressure. When the pneumatic cryogenic regulating valve operates, the control signal is processed by a pneumatic regulator and the processed signal is transmitted to the pneumatic actuator. After receiving the control signal, the pneumatic actuator controls the opening and closing of the valve by changing the air supply pressure of the air source or releasing gas.

[0003] During the use of a pneumatic cryogenic regulating valve, it is often necessary to repeatedly control the lifting of the valve stem to control the flow rate inside the valve body. This will cause frequent friction between the valve stem and the inner surface of the valve body, which will wear the outer surface of the valve stem and cause damage to the valve stem, resulting in a decrease in the control accuracy of the regulating valve. Moreover, when opening and closing, all the pressure of the working medium is placed on the valve core. To ensure the sealing performance of the regulating valve, when the valve performs the opening and closing actions, a relatively large force is often required to insert the valve core into the opening and closing port in the valve seat to complete the opening and closing of the valve body. Repeated opening and closing will cause wear of the valve core, resulting in the valve core being unable to complete the sealing, reducing the sealing performance of the regulating valve and affecting the service life of the regulating valve. When replacing the valve stem or valve core of the existing regulating valve, the entire regulating valve needs to be replaced, which is not convenient for separately replacing the valve stem or valve core. Such an operation process is not only cumbersome but also results in a high maintenance cost, which is not conducive to actual use. Summary of the Invention

[0004] The purpose of the present invention is to provide a pneumatic cryogenic regulating valve to solve the problems raised in the above background art.

[0005] To achieve the above purpose, the present invention provides the following technical solution: A pneumatic cryogenic regulating valve, including a valve body, a valve seat is arranged in the inner cavity of the valve body, a valve stem is movably inserted into the upper end of the inner cavity of the valve body, a valve core is arranged at the lower end of the valve stem, and a pneumatic actuator for regulating the opening and closing of the valve seat is installed above the valve body; A valve cover, a connecting seat and a sealing upper cover are sequentially sleeved on the valve stem from bottom to top. A support frame is fixedly installed at the upper end of the sealing upper cover, and the upper end of the support frame is fixedly connected to the lower end of the pneumatic actuator. A pneumatic lifting rod is slidably installed up and down at the lower end of the pneumatic actuator; The valve cover is connected to the upper end of the valve body by a flange. The lower end of the valve cover protrudes downward and extends to the upper end of the inner cavity of the valve body. The upper end of the valve cover is connected to the lower end of the connecting seat by a flange. Packing is installed inside the upper end of the connecting seat, and the sealing upper cover is fixedly installed at the upper end of the connecting seat; A docking rod is fixedly connected to the upper end of the valve stem. The docking rod is connected to the pneumatic lifting rod through a locking mechanism. The lower end of the valve stem is connected to the valve core through a positioning mechanism. A pneumatic transmission mechanism is arranged on the valve stem, and an airtight mechanism is installed inside the valve core. The pneumatic transmission mechanism is connected to the airtight mechanism.

[0006] As a further solution of the present invention, the locking mechanism includes a docking seat fixedly installed at the lower end of the pneumatic lifting rod. A docking groove is recessed upward at the lower end of the docking seat. Grooves are symmetrically opened on the left and right sides inside the docking groove. Threaded holes are symmetrically opened on the left and right sides of the docking seat, and the two threaded holes are respectively communicated with the adjacent grooves; The docking rod is inserted into the docking groove, and the upper end of the docking rod abuts against the upper end of the docking groove. Locking components are installed in both grooves. The two locking components are symmetrically clamped on the side of the docking rod from left to right. Locking components are installed in both threaded holes.

[0007] As a further solution of the present invention, the locking component includes a locking block slidably installed left and right in the groove. A concave block is fixedly installed on the side of the locking block close to the threaded hole. A locking spring is inserted between the concave block and the innermost side of the groove. An annular card slot is opened on the side of the docking rod. The locking block is clamped with the annular card slot. One end of the locking component is slidably connected to the concave block.

[0008] As a further solution of the present invention, the locking component includes a locking bolt threadedly installed in the threaded hole. The end of the locking bolt is fixedly connected to a locking rod. The locking rod can slide left and right along the threaded hole. One end of the locking rod passes through the side of the concave block and extends to its inner side. The locking rod is slidably connected to the concave block. A locking block is fixedly connected to the end of the locking rod inside the concave block. The locking block abuts against the side of the locking block.

[0009] As a further solution of the present invention, a piston cavity is opened at the upper end of the valve cover. The pneumatic transmission mechanism includes a piston sleeved on the valve stem. The piston is connected to the valve stem by screws. The piston is in sliding contact with the inner side wall of the piston cavity up and down. First air guide holes and second air guide holes are respectively opened inside the valve stem. The first air guide hole and the second air guide hole both penetrate downward through the lower end of the valve stem. The lower end of the first air guide hole is fixedly inserted with a first connecting pipe. The lower end of the second air guide hole is fixedly inserted with a second connecting pipe; The upper end of the first air guide hole bends to the left and is communicated with the piston cavity, and the first air guide hole is below the piston. The upper end of the second air guide hole bends to the right and is communicated with the piston cavity and the upper end of the second air guide hole is above the piston; The upper end of the valve core is recessed downward to form a first connection hole and a second connection hole. The lower end of the first connection pipe is inserted into the upper end of the first connection hole, and the lower end of the second connection pipe is inserted into the upper end of the second connection hole.

[0010] As a further solution of the present invention, a fluid sealing core protrudes downward from the lower end of the valve core. A first annular contraction groove is formed on the cylindrical surface of the fluid sealing core. An anti-leakage sealing core protrudes upward from the upper end of the valve core. A second annular contraction groove is formed on the cylindrical surface of the anti-leakage sealing core; The air sealing mechanism includes a first annular airbag sleeved in the first annular contraction groove. The inner side wall of the first annular airbag is fixedly connected to the inner side wall of the first annular contraction groove. A first air pipe is fixedly inserted into the inner side wall of the first annular airbag. One end of the first air pipe away from the first annular airbag is communicated with the first connection hole; A second annular airbag is sleeved in the second annular contraction groove. The inner side wall of the second annular airbag is fixedly connected to the inner side wall of the second annular contraction groove. A second air pipe is fixedly inserted into the inner side wall of the second annular airbag. One end of the second air pipe away from the second annular airbag is communicated with the second connection hole.

[0011] As a further solution of the present invention, the fluid sealing core matches the circular cavity of the valve seat. The lower end of the valve cover is recessed upward to form a contraction cavity, and the anti-leakage sealing core matches the contraction cavity.

[0012] As a further solution of the present invention, a first annular sealing cavity is formed on the inner side wall of the circular cavity of the valve seat. The first annular airbag matches the first annular sealing cavity. A second annular sealing cavity is formed on the inner side wall of the contraction cavity. The second annular airbag matches the second annular sealing cavity.

[0013] As a further solution of the present invention, the upper end of the anti-leakage sealing core is connected to a positioning mechanism. The lower end of the valve rod contacts the upper end of the anti-leakage sealing core. The positioning mechanism includes a positioning seat fixedly connected to the upper end of the anti-leakage sealing core. A circular hole is formed by penetrating downward through the upper end of the positioning seat. A limiting block is fixedly connected to the inner side wall of the circular hole. Circular contraction grooves are symmetrically formed on the left and right sides of the inner side wall of the circular hole. Threaded grooves are symmetrically formed on the left and right sides of the side surface of the positioning seat. The two threaded grooves are respectively communicated with the adjacent circular contraction grooves. Positioning components are installed in the two threaded grooves. The two positioning components are symmetrically distributed on the left and right sides of the lower end of the valve rod. A limiting groove is formed at the lower end of the valve rod. The limiting groove is clamped with the limiting block.

[0014] As a further solution of the present invention, the positioning assembly includes a positioning bolt threadedly installed in a threaded groove, one end of the positioning bolt passes through the threaded groove and extends into a circular contraction groove, one end of the positioning bolt in the circular contraction groove is fixedly connected to a hemispherical block, and the lower end of the valve stem is symmetrically provided with hemispherical grooves, and the hemispherical block is clamped with the adjacent hemispherical groove.

[0015] The beneficial effects of the present invention are: 1. When the regulating valve needs to be closed, the pneumatic lifting rod is moved downward by the pneumatic actuator, so that the valve stem drives the piston and the valve core to move downward, so that the fluid sealing core at the lower end of the valve core is sealed and plugged into the circular cavity of the valve seat; when the piston slides downward along the piston cavity, the gas in the piston cavity is introduced into the first air guide hole, and the gas flows into the first connecting hole along the first air guide hole and the first connecting pipe, and then enters the first annular airbag along the first air pipe, thereby expanding the first annular airbag. The expanded first annular airbag is in close contact with the first annular sealing cavity, thereby further sealing the circular cavity of the valve seat.

[0016] 2. The circular cavity of the valve seat is sealed by the cooperation of the provided fluid sealing core, air pressure transmission mechanism and air sealing mechanism to prevent leakage of the fluid through the circular cavity of the valve seat after closing the regulating valve, thereby ensuring the sealing of the regulating valve. Moreover, the cooperation of the provided air pressure transmission mechanism and air sealing mechanism reduces the wear on the air sealing mechanism when the valve core moves up and down for opening and closing, and utilizes the expandability of the airbag to enable the air sealing mechanism to always maintain a good sealing effect. In the process of the valve core moving up and down, the first annular airbag and the second annular airbag will shrink, thereby reducing wear and extending the service life.

[0017] 3. The locking mechanism and positioning mechanism can be used to easily disassemble and install the valve stem and valve core, which is convenient for later maintenance. The various components of the regulating valve are detachably connected. When a component is damaged, only the damaged component needs to be replaced. For example, the valve stem and valve core can be replaced individually without replacing the entire component, which greatly saves maintenance costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a three-dimensional diagram of the structure of the pneumatic low-temperature regulating valve of the present invention; Figure 2 This is a side sectional view of the pneumatic low-temperature regulating valve of the present invention in a closed state; Figure 3 for Figure 2 A schematic diagram of the structure at center A; Figure 4 for Figure 2 A magnified schematic diagram of the structure at point B in the middle; Figure 5This is a side sectional view of the open state structure of the pneumatic cryogenic control valve of the present invention; Figure 6 It is Figure 5 a schematic enlarged view of the structure at position C in the figure; Figure 7 This is a sectional view of the valve stem and positioning mechanism structure of the present invention; Figure 8 This is an exploded view of the valve stem, valve core and positioning mechanism structure of the present invention; Figure 9 This is an exploded view of the docking rod and locking mechanism structure of the present invention.

[0019] In the figure: 1. Valve body; 11. Valve seat; 12. First annular sealing cavity; 2. Valve cover; 21. Shrinkage cavity; 22. Second annular sealing cavity; 23. Piston cavity; 24. Connecting seat; 25. Packing; 26. Sealing upper cover; 27. Support frame; 28. Pneumatic actuator; 29. Pneumatic lifting rod; 3. Valve stem; 31. First air guide hole; 32. Second air guide hole; 33. First connecting pipe; 34. Second connecting pipe; 35. Limit groove; 36. Hemispherical card slot; 37. Piston; 38. Docking rod; 39. Annular card slot; 4. Valve core; 41. Fluid sealing core; 411. First annular shrinkage groove; 412. First annular airbag; 413. First air pipe; 42. Anti-leakage sealing core; 421. Second annular shrinkage groove; 422. Second annular airbag; 423. Second air pipe; 43. First connecting hole; 44. Second connecting hole; 5. Positioning seat; 51. Circular hole; 52. Limit block; 53. Circular shrinkage groove; 54. Positioning bolt; 55. Hemispherical block; 6. Docking seat; 61. Docking groove; 62. Groove; 63. Threaded hole; 7. Locking block; 71. Concave block; 72. Locking spring; 8. Locking bolt; 81. Locking rod; 82. Locking block. Detailed implementation manners

[0020] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0021] Please refer to Figures 1 to 9 , the present invention provides a technical solution: a pneumatic cryogenic control valve, including a valve body 1, a valve seat 11 is arranged in the inner cavity of the valve body 1, a valve stem 3 is movably inserted into the upper end of the inner cavity of the valve body 1, a valve core 4 is arranged at the lower end of the valve stem 3, and a pneumatic actuator 28 for controlling the opening and closing of the valve seat 11 is installed above the valve body 1; The valve stem 3 is sleeved with the valve cover 2, the connecting seat 24 and the sealing cover 26 in sequence from bottom to top. The upper end of the sealing cover 26 is fixedly mounted with a support frame 27. The upper end of the support frame 27 is fixedly connected to the lower end of the pneumatic actuator 28. The lower end of the pneumatic actuator 28 is slidably mounted with a pneumatic lifting rod 29. The valve cover 2 is connected to the upper end of the valve body 1 through a flange, and the lower end of the valve cover 2 protrudes downward and extends to the upper end of the inner cavity of the valve body 1. The upper end of the valve cover 2 is connected to the lower end of the connecting seat 24 through a flange. A packing 25 is installed on the inner side of the upper end of the connecting seat 24. The sealing upper cover 26 is fixedly installed on the upper end of the connecting seat 24. The packing 25 is distributed in an annular array on the outer side of the valve stem 3. The packing 25 is flexible graphite, and the valve stem 3 and the packing 25 are in sliding contact up and down. The sealing upper cover 26 seals the upper end of the connecting seat 24. The valve stem 3 is slidably connected to the valve cover 2, the connecting seat 24 and the sealing upper cover 26 respectively. The upper end of the valve stem 3 is fixedly connected to the docking rod 38, which is connected to the pneumatic lifting rod 29 through a locking mechanism. The lower end of the valve stem 3 is connected to the valve core 4 through a positioning mechanism. An air pressure transmission mechanism is provided on the valve stem 3, and an air sealing mechanism is installed in the valve core 4. The air pressure transmission mechanism is connected to the air sealing mechanism.

[0022] An indicator disk is mounted on the pneumatic lifting rod 29 , and a travel scale is mounted on one side of the indicator disk on the inner side of the support frame 27 , and the indicator disk matches the travel scale.

[0023] See also Figure 1 、 Figure 2 、 Figure 4 and Figure 9 The locking mechanism includes a docking seat 6 fixedly mounted at the lower end of the pneumatic lifting rod 29. The lower end of the docking seat 6 is recessed upward to form a docking groove 61. A groove 62 is symmetrically formed on the inner side of the docking groove 61. Threaded holes 63 are symmetrically formed on the left and right sides of the docking seat 6. The two threaded holes 63 are respectively connected to the adjacent grooves 62. The docking rod 38 is plugged into the docking groove 61, and the upper end of the docking rod 38 abuts against the upper end of the docking groove 61. Locking components are installed in the two grooves 62. The two locking components are symmetrically stuck on the side of the docking rod 38, and locking components are installed in the two threaded holes 63.

[0024] The locking assembly includes a locking block 7 that is slidably installed in the groove 62 left and right. A concave block 71 is fixedly installed on the side of the locking block 7 close to the threaded hole 63. A locking spring 72 is inserted between the concave block 71 and the innermost side of the groove 62. An annular groove 39 is provided on the side of the docking rod 38. The locking block 7 is engaged with the annular groove 39, and one end of the locking assembly is slidably connected to the concave block 71.

[0025] One side of the locking block 7 close to the annular slot 39 is provided with an arc-shaped groove, the radian of the arc-shaped groove is the same as that of the inner side wall of the annular slot 39, and the side wall of the arc-shaped groove of the locking block 7 contacts the side wall of the annular slot 39, so that the locking block 7 firmly locks the annular slot 39, and further firmly locks between the locking block 7 and the docking rod 38.

[0026] Both ends of the locking spring 72 are respectively abutted against the groove 62 and the concave block 71. The locking spring 72 applies an elastic force to the concave block 71. Under the action of the elastic force of the locking spring 72, the concave block 71 is pushed to move close to the docking rod 38, and the concave block 71 drives the locking block 7 to be clamped with the annular slot 39 on the side of the docking rod 38.

[0027] The upper end of the docking rod 38 is provided with an inclined surface. When the docking rod 38 is docked with the locking mechanism, the docking rod 38 is inserted into the docking groove 61. When the inclined surface at the upper end of the docking rod 38 contacts the locking block 7, the docking rod 38 pushes the two locking blocks 7 to move backward away from each other. At this time, the locking block 7 moves into the groove 62, and the locking block 7 drives the concave block 71 to squeeze the locking spring 72; When the upper end of the docking rod 38 contacts the upper end of the docking groove 61, under the action of the elastic force of the locking spring 72, the locking block 7 is clamped with the annular slot 39, so that the locking assembly locks the docking rod 38.

[0028] The locking assembly includes a locking bolt 8 threadedly installed in the threaded hole 63. The end of the locking bolt 8 is fixedly connected with a locking rod 81. The locking rod 81 can slide left and right along the threaded hole 63, that is, the diameter of the locking rod 81 is smaller than the minimum inner diameter of the threaded hole 63. One end of the locking rod 81 passes through the side surface of the concave block 71 and extends to its inner side. The locking rod 81 is slidably connected with the concave block 71. One end of the locking rod 81 located inside the concave block 71 is fixedly connected with a locking block 82. The locking block 82 abuts against the side surface of the locking block 7.

[0029] Initially, the locking bolt 8 is not screwed into the threaded hole 63. At this time, the locking block 82 does not contact the locking block 7, and the locking block 82 contacts the inner side wall of the concave block 71 far from the locking block 7; After the locking assembly completes the locking, the locking bolt 8 is screwed into the threaded hole 63. The locking bolt 8 drives the locking rod 81 to move into the groove 62 along the threaded hole 63. At the same time, one end of the locking rod 81 is inserted into the inner side of the concave block 71. At this time, the locking rod 81 drives the locking block 82 to approach the locking block 7 until the locking block 82 abuts against the side surface of the locking block 7. At this time, the locking bolt 8 is completely screwed into the threaded hole 63, so that the locking assembly completes the locking of the locking assembly. Through the cooperation of the provided locking assembly and the locking assembly, the docking rod 38 is firmly locked; Fix the docking rod 38 relative to the docking seat 6 and the pneumatic lifting rod 29, and further fix the valve rod 3 relative to the pneumatic lifting rod 29; When the pneumatic actuator 28 drives the pneumatic lifting rod 29 to move up and down, the pneumatic lifting rod 29 drives the valve rod 3 to move up and down synchronously through the locking mechanism.

[0030] When it is necessary to disassemble the valve rod 3, first screw out the locking bolt 8 along the threaded hole 63. The locking bolt 8 drives the locking rod 81 to move outward along the threaded hole 63. At the same time, one end of the locking rod 81 slides along the concave block 71. At this time, the locking rod 81 drives the locking block 82 away from the locking block 7; After the locking bolt 8 is completely screwed out of the threaded hole 63, at this time, the locking block 82 contacts the inner side wall of the concave block 71 away from the locking block 7. Then move the locking bolt 8 outward. The locking bolt 8 drives the locking block 82 to move into the groove 62 through the locking rod 81. The locking block 82 drives the concave block 71 to move into the groove 62. The concave block 71 drives the locking block 7 away from the annular groove 39 of the docking rod 38, so that the locking assembly releases the lock. At this time, the docking rod 38 can be driven downward by the valve rod 3, and the docking rod 38 is removed from the docking groove 61 in sequence to complete the disassembly of the valve rod 3.

[0031] Please refer to Figure 2 、 Figure 3 、 Figure 5 and Figure 8 As shown in, a piston cavity 23 is provided at the upper end of the valve cover 2. The connecting seat 24 seals the upper end of the piston cavity 23. The air pressure transmission mechanism includes a piston 37 sleeved on the valve rod 3. The piston 37 is connected to the valve rod 3 by screws. The piston 37 slides up and down in contact with the inner side wall of the piston cavity 23. First air guide holes 31 and second air guide holes 32 are respectively provided inside the valve rod 3. The first air guide hole 31 and the second air guide hole 32 both penetrate downward through the lower end of the valve rod 3. A first connecting pipe 33 is fixedly inserted at the lower end of the first air guide hole 31. A second connecting pipe 34 is fixedly inserted at the lower end of the second air guide hole 32; The upper end of the first air guide hole 31 bends to the left and communicates with the piston cavity 23, and the first air guide hole 31 is located below the piston 37. The upper end of the second air guide hole 32 bends to the right and communicates with the piston cavity 23 and the upper end of the second air guide hole 32 is located above the piston 37; The upper end of the valve core 4 is recessed downward to form a first connection hole 43 and a second connection hole 44. The lower end of the first connecting pipe 33 is inserted into the upper end of the first connection hole 43. The lower end of the second connecting pipe 34 is inserted into the upper end of the second connection hole 44. Both the first connecting pipe 33 and the second connecting pipe 34 are movably inserted with the valve core 4.

[0032] When the valve stem 3 moves downward, the valve stem 3 drives the piston 37 to slide downward along the piston cavity 23. The piston 37 compresses the gas in the piston cavity 23 downward. At the same time, the piston 37 passes the gas in the piston cavity 23 into the first air guide hole 31. The gas flows along the first air guide hole 31 and the first connecting pipe 33 into the first connecting hole 43. At the same time, the piston 37 creates a negative pressure at the upper end of the piston cavity 23 , causing the gas to enter the upper end of the piston cavity 23 along the second connecting hole 44 , the second connecting pipe 34 and the second air guide hole 32 .

[0033] When the valve stem 3 moves upward, the valve stem 3 drives the piston 37 to slide upward along the piston cavity 23. The piston 37 compresses the gas in the piston cavity 23 upward. At the same time, the piston 37 passes the gas in the piston cavity 23 into the second air guide hole 32. The gas flows along the second air guide hole 32 and the second connecting pipe 34 into the second connecting hole 44. At the same time, the piston 37 creates negative pressure at the lower end of the piston cavity 23 , causing gas to flow into the lower end of the piston cavity 23 along the first connecting hole 43 , the first connecting pipe 33 and the first air guide hole 31 .

[0034] See also Figure 3 、 Figures 6 to 8 The lower end of the valve core 4 protrudes downward and is provided with a fluid sealing core 41, and the cylindrical surface of the fluid sealing core 41 is provided with a first annular contraction groove 411. The upper end of the valve core 4 protrudes upward and is provided with a leakage-proof sealing core 42, and the cylindrical surface of the leakage-proof sealing core 42 is provided with a second annular contraction groove 421; The airtight sealing mechanism includes a first annular airbag 412 sleeved within the first annular contraction groove 411. The inner sidewall of the first annular airbag 412 is fixedly connected to the inner sidewall of the first annular contraction groove 411. A first air tube 413 is fixedly inserted into the inner sidewall of the first annular airbag 412. The first air tube 413 is in communication with the inner cavity of the first annular airbag 412. The end of the first air tube 413 away from the first annular airbag 412 is in communication with the first connecting hole 43. A second annular airbag 422 is sleeved in the second annular contraction groove 421, and the inner wall of the second annular airbag 422 is fixedly connected to the inner wall of the second annular contraction groove 421. A second air tube 423 is fixedly inserted into the inner wall of the second annular airbag 422, and the second air tube 423 is connected to the inner cavity of the second annular airbag 422. The end of the second air tube 423 away from the second annular airbag 422 is connected to the second connecting hole 44.

[0035] The fluid sealing core 41 matches the circular cavity of the valve seat 11 . The lower end of the valve cover 2 is recessed upward to form a contraction cavity 21 . The anti-leakage sealing core 42 matches the contraction cavity 21 .

[0036] The inner wall of the circular cavity of the valve seat 11 is provided with a first annular sealing cavity 12 , and the first annular airbag 412 matches the first annular sealing cavity 12 . The inner wall of the contraction cavity 21 is provided with a second annular sealing cavity 22 , and the second annular airbag 422 matches the second annular sealing cavity 22 .

[0037] When the valve stem 3 moves downward, the valve stem 3 drives the valve core 4 to move downward, so that the leakage-proof sealing core 42 at the upper end of the valve core 4 is separated from the contraction cavity 21 of the valve cover 2, and the fluid sealing core 41 at the lower end of the valve core 4 is sealed and plugged into the circular cavity of the valve seat 11. At the same time, the gas flowing into the first connecting hole 43 will enter the first annular airbag 412 along the first air pipe 413, thereby expanding the first annular airbag 412. The expanded first annular airbag 412 is in close contact with the first annular sealing cavity 12, thereby further forming a seal.

[0038] At the same time, the gas enters the upper end of the piston cavity 23 along the second connecting hole 44, the second connecting tube 34 and the second air guide hole 32, causing the gas in the second annular airbag 422 to flow out along the second air tube 423 into the second connecting hole 44, causing the second annular airbag 422 to shrink into the second annular shrinkage groove 421.

[0039] The circular cavity of the valve seat 11 is sealed by cooperating with the provided fluid sealing core 41, the air pressure transmission mechanism and the air sealing mechanism to prevent leakage of the fluid through the circular cavity of the valve seat 11 after closing the regulating valve, thereby ensuring the sealing of the regulating valve. Moreover, the air pressure transmission mechanism and the air sealing mechanism cooperate with each other, and when the valve core 4 moves up and down to open and close, the wear on the air sealing mechanism is small, and the expandability of the airbag is utilized to enable the air sealing mechanism to always maintain a good sealing effect.

[0040] When the valve stem 3 moves upward, the valve stem 3 drives the valve core 4 to move upward, so that the fluid sealing core 41 at the lower end of the valve core 4 is separated from the circular cavity of the valve seat 11, and the leakage-proof sealing core 42 at the upper end of the valve core 4 is sealed and plugged into the contraction cavity 21 of the valve cover 2. At the same time, the gas flowing into the second connecting hole 44 will enter the second annular airbag 422 along the second air pipe 423, thereby expanding the second annular airbag 422. The expanded second annular airbag 422 is in close contact with the second annular sealing cavity 22, thereby forming a seal for the contraction cavity 21 and preventing the fluid from flowing upward along the contraction cavity 21.

[0041] At the same time, the gas enters the lower end of the piston cavity 23 along the first connecting hole 43, the first connecting tube 33 and the first air guide hole 31, causing the gas in the first annular airbag 412 to flow out along the first air tube 413 into the first connecting hole 43, causing the first annular airbag 412 to shrink into the first annular sealing cavity 12.

[0042] During the up and down movement of the valve core 4 , the first annular airbag 412 and the second annular airbag 422 will shrink, thereby reducing wear and extending the service life.

[0043] See also Figure 2 、 Figure 3 、 Figure 7 and Figure 8 The upper end of the anti-leakage sealing core 42 is connected to the positioning mechanism, and the lower end of the valve stem 3 contacts the upper end of the anti-leakage sealing core 42. The positioning mechanism includes a positioning seat 5 fixedly connected to the upper end of the anti-leakage sealing core 42. The upper end of the positioning seat 5 is downwardly penetrated with a circular hole 51. The inner side wall of the circular hole 51 is fixedly connected to the limiting block 52. The inner side wall of the circular hole 51 is symmetrically provided with a circular contraction groove 53. The side of the positioning seat 5 is symmetrically provided with a threaded groove. The two threaded grooves are respectively connected to the adjacent circular contraction grooves 53. Positioning components are installed in the two threaded grooves. The two positioning components are symmetrically distributed on the left and right sides of the lower end of the valve stem 3. The lower end of the valve stem 3 is provided with a limiting groove 35, and the limiting groove 35 is clamped with the limiting block 52.

[0044] The positioning assembly includes a positioning bolt 54 threadedly installed in the thread groove, one end of the positioning bolt 54 passes through the thread groove and extends into the circular contraction groove 53, and one end of the positioning bolt 54 in the circular contraction groove 53 is fixedly connected to a hemispherical block 55, and the lower end of the valve stem 3 is symmetrically provided with a hemispherical slot 36, and the hemispherical block 55 is engaged with the adjacent hemispherical slot 36.

[0045] When the valve stem 3 is docked with the valve core 4, the lower end of the valve stem 3 is inserted into the circular hole 51 of the positioning seat 5, and the limiting groove 35 is engaged with the limiting block 52. At this time, the valve stem 3 drives the first connecting tube 33 and the second connecting tube 34 to move downward synchronously, so that the lower end of the first connecting tube 33 is accurately plugged into the upper end of the first connecting hole 43, and the lower end of the second connecting tube 34 is accurately plugged into the upper end of the second connecting hole 44; When the lower end of the valve stem 3 contacts the upper end of the anti-leakage sealing core 42, the positioning bolt 54 is screwed into the threaded groove. The positioning bolt 54 drives the hemispherical block 55 to move out of the circular contraction groove 53, so that the hemispherical block 55 is clamped into the hemispherical clamping groove 36, thereby completing the locking of the valve stem 3, so that the valve stem 3, the positioning seat 5 and the valve core 4 are relatively fixed, and then the valve stem 3 and the valve core 4 move up and down synchronously.

[0046] During disassembly, first unscrew the positioning bolt 54 outward along the threaded groove. The positioning bolt 54 drives the hemispherical block 55 to shrink to the circular shrinkage groove 53, and at the same time separates the hemispherical block 55 from the hemispherical slot 36, thereby releasing the lock on the valve stem 3, and then move the valve stem 3 out of the circular hole 51 of the positioning seat 5 to complete the disassembly of the valve stem 3.

[0047] Working principle: When the control valve needs to be closed, the pneumatic lifting rod 29 is moved downward by the pneumatic actuator 28. The pneumatic lifting rod 29 drives the docking rod 38 and the valve stem 3 to move downward through the locking mechanism. The valve stem 3 drives the piston 37 and the valve core 4 to move downward, so that the fluid sealing core 41 at the lower end of the valve core 4 is hermetically inserted into the circular cavity of the valve seat 11. When the piston 37 slides downward along the piston cavity 23, the gas in the piston cavity 23 is introduced into the first air guide hole 31. The gas flows into the first connection hole 43 along the first air guide hole 31 and the first connecting pipe 33, and then the gas enters the first annular airbag 412 along the first air pipe 413, so that the first annular airbag 412 expands. The expanded first annular airbag 412 is in close contact with the first annular sealing cavity 12, thereby further sealing the circular cavity of the valve seat 11.

[0048] At the same time, the gas in the second annular airbag 422 flows out along the second air pipe 423 and enters the second connection hole 44. The gas enters the upper end of the piston cavity 23 along the second connection hole 44, the second connecting pipe 34 and the second air guide hole 32, so that the second annular airbag 422 shrinks into the second annular contraction groove 421.

[0049] Through the cooperation of the fluid sealing core 41, the air pressure transmission mechanism and the airtight sealing mechanism, the circular cavity of the valve seat 11 is sealed, preventing fluid from leaking through the circular cavity of the valve seat 11 after the control valve is closed, ensuring the sealing performance of the control valve. And through the cooperation of the air pressure transmission mechanism and the airtight sealing mechanism, when the valve core 4 moves up and down for opening and closing, the wear of the airtight sealing mechanism is small, and by using the expansibility of the airbag, the airtight sealing mechanism can always maintain a good sealing effect.

[0050] When the control valve needs to be opened, the pneumatic lifting rod 29 is moved upward by the pneumatic actuator 28, so that the valve stem 3 drives the piston 37 and the valve core 4 to move upward, separating the fluid sealing core 41 at the lower end of the valve core 4 from the circular cavity of the valve seat 11, and making the anti-leakage sealing core 42 at the upper end of the valve core 4 hermetically inserted into the contraction cavity 21 of the valve cover 2. At the same time, the gas flowing into the second connection hole 44 will enter the second annular airbag 422 along the second air pipe 423, so that the second annular airbag 422 expands. The expanded second annular airbag 422 is in close contact with the second annular sealing cavity 22, thereby sealing the contraction cavity 21 to prevent fluid from flowing upward along the contraction cavity 21.

[0051] At the same time, the gas enters the lower end of the piston cavity 23 along the first connection hole 43, the first connecting pipe 33 and the first air guide hole 31, so that the gas in the first annular airbag 412 flows out along the first air pipe 413 and enters the first connection hole 43, making the first annular airbag 412 shrink into the first annular sealing cavity 12.

[0052] During the up and down movement of the valve core 4, the first annular airbag 412 and the second annular airbag 422 will contract, thereby reducing wear and extending the service life.

[0053] When the valve stem 3 needs to be disassembled after long-term use, first screw out the locking bolt 8 along the threaded hole 63, and then pull the locking bolt 8. The locking bolt 8 drives the locking block 82 to move into the groove 62 through the locking rod 81. The locking block 82 drives the concave block 71 to move into the groove 62. The concave block 71 drives the locking card 7 away from the annular slot 39 of the docking rod 38, so that the locking assembly releases the lock. At this time, the valve stem 3 can drive the docking rod 38 to move downward, so that the docking rod 38 is removed from the docking groove 61 in sequence, and the upper end of the valve stem 3 is disassembled; Then separate the connecting seat 24 from the valve cover 2, take out the connecting seat 24 upward along the valve stem 3, separate the valve cover 2 from the valve body 1, and drive the valve core 4 out of the inner cavity of the valve body 1 by the valve stem 3; Then screw out the positioning bolt 54 along the thread groove. The positioning bolt 54 drives the hemispherical block 55 to contract into the circular contraction groove 53, and at the same time separates the hemispherical block 55 from the hemispherical slot 36, thereby releasing the lock on the valve stem 3. Then remove the valve stem 3 from the circular hole 51 of the positioning seat 5 to complete the disassembly of the valve stem 3.

[0054] Take out the valve cover 2 downward along the valve stem 3, and then disassemble the piston 37 from the valve stem 3, and the valve stem 3 can be replaced.

[0055] During installation, first assemble the piston 37 and the valve stem 3, and respectively sleeve the valve cover 2 on the lower end of the valve stem 3; Insert the lower end of the valve stem 3 into the circular hole 51 of the positioning seat 5, make the limit groove 35 engage with the limit block 52, and then lock the valve stem 3 through the positioning component to complete the assembly of the valve stem 3 and the valve core 4. Insert the lower end of the valve stem 3 and the valve core 4 into the inner cavity of the valve body 1, and fix the valve cover 2 to the valve body 1; Then sleeve the connecting seat 24 on the upper end of the valve stem 3, and fix the valve cover 2 to the connecting seat 24; Insert the docking rod 38 at the upper end of the valve stem 3 into the docking groove 61 of the docking seat 6, so that the locking component and the locking assembly cooperate to firmly lock the docking rod 38.

[0056] The disassembly and installation of the valve stem 3 and the valve core 4 are simple and convenient, which is convenient for later maintenance. The components of the regulating valve are detachably connected. When a certain component is damaged, only the damaged component needs to be replaced, such as the valve stem 3, the valve core 4, etc., which can be replaced separately without overall replacement, greatly saving the maintenance cost.

[0057] Although embodiments of the present invention have been shown and described, those of ordinary skill in the art will appreciate that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A pneumatic low-temperature regulating valve, comprising a valve body (1), an inner cavity of the valve body (1) being provided with a valve seat (11), a valve stem (3) being movably connected to the upper end of the inner cavity of the valve body (1), a valve core (4) being provided at the lower end of the valve stem (3), and a pneumatic actuator (28) for regulating the opening and closing of the valve seat (11) being installed above the valve body (1); Its characteristics are: The valve stem (3) is sleeved with a valve cover (2), a connecting seat (24) and a sealing upper cover (26) in sequence from bottom to top, the upper end of the sealing upper cover (26) is fixedly mounted with a support frame (27), the upper end of the support frame (27) is fixedly connected to the lower end of the pneumatic actuator (28), and the lower end of the pneumatic actuator (28) is slidably mounted with a pneumatic lifting rod (29); The valve cover (2) is connected to the upper end of the valve body (1) through a flange, the lower end of the valve cover (2) protrudes downward and extends to the upper end of the inner cavity of the valve body (1), the upper end of the valve cover (2) is connected to the lower end of the connecting seat (24) through a flange, a packing (25) is installed on the inner side of the upper end of the connecting seat (24), and a sealing upper cover (26) is fixedly installed on the upper end of the connecting seat (24); The upper end of the valve stem (3) is fixedly connected to a docking rod (38), which is connected to a pneumatic lifting rod (29) via a locking mechanism. The lower end of the valve stem (3) is connected to the valve core (4) via a positioning mechanism. A pneumatic transmission mechanism is provided on the valve stem (3), and a gas sealing mechanism is installed in the valve core (4). The pneumatic transmission mechanism is connected to the gas sealing mechanism.

2. The pneumatic low-temperature regulating valve according to claim 1, wherein: The locking mechanism includes a docking seat (6) fixedly mounted on the lower end of the pneumatic lifting rod (29), the lower end of the docking seat (6) is recessed upward to form a docking groove (61), the inner side of the docking groove (61) is symmetrically provided with grooves (62), and the left and right sides of the docking seat (6) are symmetrically provided with threaded holes (63), and the two threaded holes (63) are respectively connected to the adjacent grooves (62); The docking rod (38) is plugged into the docking groove (61), and the upper end of the docking rod (38) abuts against the upper end of the docking groove (61). Locking components are installed in the two grooves (62). The two locking components are symmetrically clamped on the side of the docking rod (38). Locking components are installed in the two threaded holes (63).

3. The pneumatic low-temperature regulating valve according to claim 2, characterized in that: The locking assembly includes a locking block (7) slidably mounted in the groove (62) to the left and right, a concave block (71) fixedly mounted on one side of the locking block (7) close to the threaded hole (63), a locking spring (72) inserted between the concave block (71) and the innermost side of the groove (62), an annular groove (39) is provided on the side of the docking rod (38), the locking block (7) is engaged with the annular groove (39), and one end of the locking assembly is slidably connected to the concave block (71).

4. The pneumatic low-temperature regulating valve according to claim 3, characterized in that: The locking assembly includes a locking bolt (8) threadedly installed in the threaded hole (63). The end of the locking bolt (8) is fixedly connected to a locking rod (81). The locking rod (81) can slide left and right along the threaded hole (63). One end of the locking rod (81) passes through the side surface of the concave block (71) and extends to its inner side. The locking rod (81) is slidably connected to the concave block (71). One end of the locking rod (81) inside the concave block (71) is fixedly connected to a locking block (82). The locking block (82) abuts against the side surface of the locking catch block (7).

5. The pneumatic cryogenic control valve according to claim 1, characterized in that: The upper end of the valve cover (2) is provided with a piston cavity (23). The air pressure transmission mechanism includes a piston (37) sleeved on the valve rod (3). The piston (37) is connected to the valve rod (3) by screws. The piston (37) is in sliding contact with the inner side wall of the piston cavity (23) up and down. The inner side of the valve rod (3) is respectively provided with a first air guide hole (31) and a second air guide hole (32). Both the first air guide hole (31) and the second air guide hole (32) penetrate downward through the lower end of the valve rod (3). The lower end of the first air guide hole (31) is fixedly inserted with a first connecting pipe (33). The lower end of the second air guide hole (32) is fixedly inserted with a second connecting pipe (34); The upper end of the first air guide hole (31) bends leftward and communicates with the piston cavity (23), and the first air guide hole (31) is located below the piston (37). The upper end of the second air guide hole (32) bends rightward and communicates with the piston cavity (23), and the upper end of the second air guide hole (32) is located above the piston (37); The upper end of the valve core (4) is recessed downward to form a first connection hole (43) and a second connection hole (44). The lower end of the first connecting pipe (33) is inserted into the upper end of the first connection hole (43). The lower end of the second connecting pipe (34) is inserted into the upper end of the second connection hole (44).

6. The pneumatic cryogenic control valve according to claim 5, wherein: The lower end of the valve core (4) protrudes downward to be provided with a fluid sealing core (41). The cylindrical surface of the fluid sealing core (41) is provided with a first annular shrinkage groove (411). The upper end of the valve core (4) protrudes upward to be provided with a leakage-proof sealing core (42). The cylindrical surface of the leakage-proof sealing core (42) is provided with a second annular shrinkage groove (421); The air sealing mechanism includes a first annular airbag (412) sleeved in the first annular shrinkage groove (411). The inner side wall of the first annular airbag (412) is fixedly connected to the inner side wall of the first annular shrinkage groove (411). The inner side wall of the first annular airbag (412) is fixedly inserted with a first air pipe (413). One end of the first air pipe (413) away from the first annular airbag (412) communicates with the first connection hole (43); A second annular airbag (422) is sleeved in the second annular shrinkage groove (421). The inner side wall of the second annular airbag (422) is fixedly connected to the inner side wall of the second annular shrinkage groove (421). The inner side wall of the second annular airbag (422) is fixedly inserted with a second air pipe (423). One end of the second air pipe (423) away from the second annular airbag (422) communicates with the second connection hole (44).

7. The pneumatic cryogenic control valve according to claim 6, characterized in that: The fluid sealing core (41) matches the circular cavity of the valve seat (11). The lower end of the valve cover (2) is recessed upward to form a contraction cavity (21), and the anti-leakage sealing core (42) matches the contraction cavity (21).

8. The pneumatic cryogenic control valve according to claim 7, wherein: The inner side wall of the circular cavity of the valve seat (11) is provided with a first annular sealing cavity (12), and the first annular airbag (412) matches the first annular sealing cavity (12). The inner side wall of the contraction cavity (21) is provided with a second annular sealing cavity (22), and the second annular airbag (422) matches the second annular sealing cavity (22).

9. The pneumatic low-temperature regulating valve according to claim 6, characterized in that: The upper end of the anti-leakage sealing core (42) is connected to the positioning mechanism. The lower end of the valve stem (3) contacts the upper end of the anti-leakage sealing core (42). The positioning mechanism includes a positioning seat (5) fixedly connected to the upper end of the anti-leakage sealing core (42). A circular hole (51) is formed by penetrating downward through the upper end of the positioning seat (5). A limiting block (52) is fixedly connected to the inner side wall of the circular hole (51). Circular contraction grooves (53) are symmetrically formed on the left and right sides of the inner side wall of the circular hole (51). Thread grooves are symmetrically formed on the left and right sides of the side surface of the positioning seat (5), and the two thread grooves are respectively communicated with the adjacent circular contraction grooves (53). Positioning components are installed in both of the two thread grooves, and the two positioning components are symmetrically distributed on the left and right sides of the lower end of the valve stem (3). A limiting groove (35) is formed at the lower end of the valve stem (3), and the limiting groove (35) is clamped with the limiting block (52).

10. A pneumatic low-temperature control valve according to claim 9, characterized in that: The positioning component includes a positioning bolt (54) threadedly installed in the thread groove. One end of the positioning bolt (54) passes through the thread groove and extends into the circular contraction groove (53). A hemispherical block (55) is fixedly connected to the end of the positioning bolt (54) located in the circular contraction groove (53). Hemispherical clamping grooves (36) are symmetrically formed on the left and right sides of the lower end of the valve stem (3), and the hemispherical block (55) is clamped with the adjacent hemispherical clamping groove (36).

Images