Diaphragm valve with locking function

Abstract

The application discloses a diaphragm valve with a locking function, which comprises a valve body, a valve cover, a diaphragm, a valve rod, a valve rod nut, a hand wheel, a valve shaft, an interlocking mechanism and a locking mechanism, the valve shaft penetrates the diaphragm in the vertical direction, the valve shaft is fixedly connected with the middle part of the diaphragm, a support table is arranged in the valve body, an axle hole for the lower end of the valve shaft to pass through is arranged on the support table, the lower end of the valve rod is connected with the upper end of the valve shaft through the interlocking mechanism, the locking mechanism is arranged at the position corresponding to the lower end of the axle hole of the valve body, the locking mechanism comprises a locking sleeve, a plurality of locking rods and an operating ring, an annular locking groove is arranged at the position close to the lower end of the outer periphery of the valve shaft, when the valve rod drives the valve shaft to move to the lower limit position, the lower end of the valve shaft extends into the locking sleeve, and when the operating ring is rotated, the locking rod has a locking position in which the inner end is inserted into the annular locking groove and an unlocking position in which the inner end is separated from the annular locking groove. The diaphragm valve can be locked when it needs to be closed for a long time, so that safety accidents caused by accidental touching are prevented.

Description

Technical Field

[0001] This invention relates to the field of valve structure technology, and in particular to a diaphragm valve with a locking function. Background Technology

[0002] A diaphragm valve is a shut-off valve that uses a diaphragm as the opening and closing element to close the flow channel, cut off the fluid, and separate the valve body cavity from the valve cover cavity. In existing diaphragm valves, a valve stem nut is rotatably mounted on the upper end of the valve cover. A handwheel is circumferentially linked (e.g., keyed) to the valve stem nut, with the valve stem passing through the nut and the two threads engaging. This threaded connection also limits the circumferential movement of the valve stem, restricting its movement to axial. The outer edge of the diaphragm is clamped and fixed between the valve cover and the valve body, and the middle of the diaphragm is connected to the lower end of the valve stem. Therefore, by rotating the handwheel to move the valve stem up and down, the diaphragm can be switched between a closed and open fluid passage state.

[0003] Because the handwheel of a diaphragm valve rotates flexibly, there is a risk of accidental contact causing it to rotate, which could then drive the valve stem and move the diaphragm, resulting in unexpected changes in the valve opening. When diaphragm valves are used in high-pressure environments such as natural gas or oil transportation, this can easily lead to safety accidents. Therefore, it is necessary to design a diaphragm valve with a locking function, allowing it to be locked in the closed position when prolonged closure is required, thereby preventing safety accidents caused by accidental contact. Summary of the Invention

[0004] The purpose of this invention is to provide a diaphragm valve with a locking function. This invention can lock the diaphragm valve when it needs to be closed for a long time to prevent accidental contact that could lead to safety accidents. At the same time, it supports online maintenance, which can avoid affecting production efficiency.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a diaphragm valve with a locking function, comprising a valve body, a valve cover mounted on the upper end of the valve body, a diaphragm sandwiched between the valve body and the valve cover, a valve stem penetrating the valve cover and connected to the diaphragm, a valve stem nut rotatably disposed on the upper end of the valve cover and threadedly engaged with the valve stem, and a handwheel circumferentially linked to the outer periphery of the valve stem thread; further comprising a valve shaft, an interlocking mechanism, and a locking mechanism, wherein the valve shaft vertically penetrates the diaphragm and is fixedly connected to the middle of the diaphragm, and a support platform is provided inside the valve body, wherein a vertically penetrating part for the valve shaft is provided on the support platform. The lower end of the valve stem passes through a shaft hole, and the lower end of the valve stem is connected to the upper end of the valve shaft through an interlocking mechanism. The locking mechanism is located at the lower end of the corresponding shaft hole in the valve body. The locking mechanism includes a locking sleeve, multiple locking rods that are radially movable on the locking sleeve, and an operating ring that is rotatably disposed on the outer periphery of the locking sleeve and engages with the locking rods. An annular locking groove is provided on the outer periphery of the valve shaft near the lower end. When the valve stem drives the valve shaft to move to the lower limit position, the lower end of the valve shaft extends into the locking sleeve. When the operating ring is rotated, the locking rod has a locking position where the inner end is inserted into the annular locking groove and an unlocking position where the inner end is disengaged from the annular locking groove.

[0006] By adopting the above technical solution, when the valve stem drives the valve shaft to its lower limit position (i.e., the valve is fully closed), the lower end of the valve shaft extends into the locking sleeve, and the annular locking groove on the outer circumference of the valve shaft is exposed to the action range of the locking rod. At this time, rotating the operating ring allows the inner end of the locking rod to insert into the annular locking groove. This allows the locking mechanism to firmly fix the valve shaft position, thereby directly preventing axial movement of the valve shaft. Since the valve shaft is fixedly connected to the diaphragm, the diaphragm position is locked. Even if the handwheel is accidentally touched, the valve stem and valve shaft will not move axially, thus eliminating the risk of unexpected changes in valve opening. To unlock, rotating the operating ring disengages the inner end of the locking rod from the annular locking groove, restoring the valve shaft's freedom of movement and allowing it to operate normally. This design can lock the diaphragm valve when it needs to be closed for a long period, preventing accidental contact that could lead to a safety accident.

[0007] The invention is further configured such that the locking mechanism includes a number of first springs and transmission balls equal to the number of locking rods. A guide hole is radially provided on the outer periphery of the locking sleeve. The locking rod is movably disposed within the guide hole. A guide flange is provided on the outer periphery of the locking rod, with its outer surface fitting against the inner surface of the guide hole. A limiting flange is provided at the inner end of the guide hole, with its inner surface fitting against the outer surface of the locking rod. The first spring is sandwiched between the guide flange and the limiting flange. The transmission ball is rotatably disposed between the locking rod and the operating ring. The inner surface of the operating ring has an arc-shaped groove for the transmission ball to partially extend into. The arc-shaped groove includes a groove one and a groove two, with the depth of groove two greater than the depth of groove one. Grooves one and two are connected by a guide ramp. When the transmission ball switches between groove one and groove two, the inner end of the locking rod inserts into or disengages from the annular locking groove.

[0008] By adopting the above technical solution, when the transmission ball switches between slot one and slot two, the inner end of the locking rod is inserted into or disengaged from the annular locking groove accordingly. The groove design with different depths not only triggers the movement of the locking rod, but also provides clear tactile feedback (resistance difference) in the locking state. The operator can clearly perceive the position, thereby effectively suppressing the risk of misoperation, and ensuring the long-term stability of valve locking, especially under high pressure conditions.

[0009] The present invention is further configured such that the bottom of the valve body is provided with an installation groove, the upper end of the locking sleeve is threadedly connected to the installation groove, and the lower end of the locking sleeve is provided with a hexagonal operating part with a hexagonal outer contour. A first retaining spring is respectively engaged at the upper and lower ends of the operating ring on the outer periphery of the locking sleeve.

[0010] By adopting the above technical solution, the locking sleeve can be fixedly installed and the operating ring can be rotated. The installation structure is simple and reliable, and disassembly and assembly are very convenient.

[0011] The invention is further configured such that the interlocking mechanism includes an interlocking ring and at least one transmission rod. The interlocking ring is sleeved on the outer periphery of the upper end of the valve stem. A second retaining ring is respectively engaged at the upper and lower ends of the valve stem corresponding to the interlocking ring. The interlocking ring has a radially openable outer hole, and the valve stem has a corresponding openable inner hole on its side. The transmission rod is radially movable in the openable outer hole and the openable inner hole. The lower end of the valve stem is provided with a mating sleeve, which is sleeved on the outer periphery of the interlocking ring. An annular interlocking groove is opened on the inner circular surface of the mating sleeve. When the transmission rod moves, it has an interlocking position where its outer end is inserted into the interlocking groove and a separation position where its outer end is disengaged from the interlocking groove.

[0012] By adopting the above technical solution, a locking connection between the valve stem and the valve shaft can be achieved, enabling axial linkage between the two.

[0013] The invention is further configured such that the interlocking mechanism includes an interlocking rod and a second spring; a guide hole is provided extending upward from the center of the lower end of the valve shaft, and the guide hole does not penetrate the upper end of the valve shaft; the movable inner hole communicates with the guide hole; the interlocking rod is partially vertically movable within the guide hole, and the lower end of the interlocking rod is always located outside the guide hole; an annular deep groove and an annular shallow groove are sequentially provided vertically along the outer periphery of the interlocking rod; a tapered guide surface is provided between the annular deep groove and the annular shallow groove; a first annular flange is provided on the outer periphery of the transmission rod; the first annular flange... The outer circular surface is in contact with the inner circular surface of the movable outer hole. The inner end of the movable outer hole is provided with a second annular flange. A limit ring is fixedly installed at the outer end of the movable outer hole. The inner circular surfaces of the second annular flange and the limit ring are both in contact with the outer circular surface of the transmission rod. The second spring is clamped between the limit ring and the first annular flange. When the interlocking rod moves vertically, the inner end of the transmission rod switches between the annular deep groove and the annular shallow groove. When the inner end of the transmission rod is inserted into the annular shallow groove, the transmission rod is in the interlocked position. When the inner end of the transmission rod is inserted into the annular deep groove, the transmission rod is in the disengaged position.

[0014] By adopting the above technical solution and introducing an interlocking rod, the locking or unlocking between the valve stem and the valve shaft can be operated externally. That is, by pulling down the interlocking rod, the transmission rod disengages from the interlocking groove of the mating sleeve, thus separating the valve stem and the valve shaft. At the same time, rotating the operating ring locks the valve shaft. The valve cover, valve stem, and handwheel can be disassembled online to replace damaged parts, thus supporting online maintenance without stopping the machine and avoiding impact on production efficiency.

[0015] The present invention is further configured such that an exhaust hole extending to the outside of the valve shaft is provided at the upper end of the guide hole.

[0016] By adopting the above technical solution, when the interlocking rod moves up and down in the guide hole, the internal air can circulate freely through the exhaust hole, avoiding the large operating resistance or jamming caused by air compression.

[0017] The invention is further configured to include a pressure ring, which is connected to the valve body by a plurality of first screws. The upper end of the pressure ring is provided with a relief groove for the screw heads of the first screws to be inserted. The diaphragm is sandwiched between the valve body and the valve cover. The lower end of the pressure ring is also provided with a plurality of hexagonal grooves, in which a plurality of hexagonal nuts are embedded. A plurality of second screws are passed through the valve cover, and the second screws pass through the pressure ring and are threadedly engaged with the corresponding hexagonal nuts.

[0018] By adopting the above technical solution, when maintaining the valve cover, valve stem, and handwheel components, the diaphragm is pressed tightly onto the valve body by the pressure ring. Even if the valve cover, valve stem, and handwheel components are disassembled, the diaphragm seal will not be affected, making maintenance operations very convenient.

[0019] The invention is further configured such that the diaphragm has a cylindrical fixing part in the middle, the valve shaft passes through the fixing part from top to bottom, the valve shaft has an annular positioning protrusion on its outer periphery, the fixing part has an annular positioning cavity that fits with the annular positioning protrusion, the valve shaft is threaded with a locking nut at the upper and lower ends of the fixing part respectively, and the two locking nuts abut against the upper and lower ends of the fixing part respectively, and the support platform is also provided with a clearance recess for the fixing part and the locking nut to be inserted.

[0020] By adopting the above technical solution and tightening the two locking nuts, not only can the annular positioning protrusion on the valve shaft be locked together with the fixed part, but the locking nuts also apply positive pressure to the fixed part on the annular positioning protrusion, which can improve the sealing between the two and prevent the internal medium from leaking from the gap between them.

[0021] The invention is further configured such that the inner end of the recessed portion is provided with a threaded groove coaxial with the shaft hole, a sealing sleeve is threadedly connected in the threaded groove, a sealing gasket is sandwiched between the sealing sleeve and the threaded groove, and a first sealing ring is provided on the inner circular surface of the sealing sleeve for forming a sealing fit with the outer circular surface of the valve shaft; a plurality of second sealing rings are provided on the outer circular surface of the interlocking rod for forming a sealing fit with the inner circular surface of the guide hole.

[0022] By adopting the above technical solution, the sealing between the outer circular surface of the valve shaft and the inner circular surface of the shaft hole, and between the outer circular surface of the interlocking rod and the inner circular surface of the guide hole can be guaranteed, thus preventing the leakage of internal media.

[0023] The invention is further configured such that the inner wall of the valve cover is provided with a plurality of vertically extending guide grooves, and the mating sleeve is provided with guide blocks that cooperate with the guide grooves.

[0024] By adopting the above technical solution, the mating sleeve is circumferentially limited, so that it can only perform stable axial movement and will not rotate. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the valve in the open state (locking mechanism unlocked, interlocking mechanism locked) of the present invention;

[0026] Figure 2 This is a schematic diagram of the valve in the closed state (locking mechanism unlocked, interlocking mechanism locked) of the present invention;

[0027] Figure 3 This is a schematic diagram of the valve in the closed state (locking mechanism locked, interlocking mechanism locked) of the present invention;

[0028] Figure 4 for Figure 3 Enlarged structural diagram of section A in the middle;

[0029] Figure 5 This is a schematic diagram of the cooperation structure between the operating ring and the transmission ball of the present invention;

[0030] Figure 6 This is a cross-sectional view of the interlocking mechanism of the present invention;

[0031] Figure 7 This is a schematic diagram of the valve in the closed state of the present invention (locking mechanism locked, interlocking mechanism unlocked);

[0032] Figure 8 This is a schematic diagram of the valve in the closed state of the present invention (locking mechanism locked, valve stem and valve shaft separated);

[0033] Figure 9 for Figure 8 Enlarged structural diagram of section B in the middle;

[0034] Figure 10 for Figure 8 Enlarged structural diagram of section C;

[0035] Figure 11 for Figure 8 Enlarged structural diagram of section D in the middle;

[0036] Figure 12 for Figure 8 A magnified structural diagram of section E in the middle.

[0037] In the diagram: 1. Valve body; 2. Valve cover; 3. Diaphragm; 4. Valve stem; 5. Valve stem nut; 6. Handwheel; 7. Valve shaft; 8. Interlocking mechanism; 9. Locking mechanism; 10. Support platform; 11. Shaft hole; 12. Locking sleeve; 13. Locking rod; 14. Operating ring; 15. Annular locking groove; 16. First spring; 17. Transmission ball; 18. Guide hole; 19. Guide flange; 20. Limiting flange; 21. Groove 1; 22. Groove 2; 23. Guide slope; 24. Mounting groove; 25. Hexagonal operating part; 26. First snap ring; 27. Interlocking ring; 28. Transmission rod; 29. ​​Second snap ring; 30. Movable outer hole; 31. Movable inner hole; 32. Interlocking groove; 33. Interlocking 34. Rod; 35. Second spring; 36. Guide hole; 37. Annular deep groove; 38. Annular shallow groove; 39. Conical guide surface; 40. First annular flange; 41. Second annular flange; 42. Limiting ring; 43. Vent hole; 44. Pressure ring; 45. First screw; 46. Relief groove; 47. Hexagonal groove; 48. Hexagonal nut; 49. Second screw; 50. Fixing part; 51. Annular positioning protrusion; 52. Annular positioning cavity; 53. Locking nut; 54. Relief recess; 55. Threaded groove; 56. Sealing sleeve; 57. Sealing gasket; 58. First sealing ring; 59. Second sealing ring; 60. Guide groove; 61. Arc groove; 62. Connecting sleeve. Detailed Implementation

[0038] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0039] Example: As attached Figures 1-12 The diaphragm valve shown includes a valve body 1, a valve cover 2 mounted on the upper end of the valve body 1, a diaphragm 3 sandwiched between the valve body 1 and the valve cover 2, a valve stem 4 penetrating the valve cover 2 and connected to the diaphragm 3, a valve stem nut 5 rotatably mounted on the upper end of the valve cover 2 and threadedly engaged with the valve stem 4, and a handwheel 6 circumferentially linked to the outer periphery of the thread on the valve stem 4. The diaphragm valve also includes a valve shaft 7, an interlocking mechanism 8, and a locking mechanism 9. The valve shaft 7 vertically penetrates the diaphragm 3 and is fixedly connected to the middle of the diaphragm 3. A support platform 10 is provided inside the valve body 1, and a shaft hole 11 is vertically provided on the support platform 10 for the lower end of the valve shaft 7 to pass through. The lower end of the valve stem 4 is connected to the upper end of the valve shaft 7 through an interlocking mechanism 8. The locking mechanism 9 is located at the lower end of the valve body 1 corresponding to the shaft hole 11. The locking mechanism 9 includes a locking sleeve 12, a plurality of locking rods 13 that are radially movably arranged on the locking sleeve 12, and an operating ring 14 that is rotatably arranged on the outer periphery of the locking sleeve 12 and is linked with the locking rods 13. The valve shaft 7 has an annular locking groove 15 near the lower end on the outer periphery. When the valve stem 4 drives the valve shaft 7 to move to the lower limit position, the lower end of the valve shaft 7 extends into the locking sleeve 12. When the operating ring 14 is rotated, the locking rod 13 has a locking position where the inner end is inserted into the annular locking groove 15 and an unlocking position where the inner end is disengaged from the annular locking groove 15. When the valve stem 4 drives the valve shaft 7 to its lower limit position (i.e., the valve is fully closed), the diaphragm 3 blocks the flow channels at both ends of the valve body 1. The lower end of the valve shaft 7 extends into the locking sleeve 12, and the annular locking groove 15 on the outer periphery of the valve shaft 7 is exposed to the range of action of the locking rod 13. At this time, rotating the operating ring 14 allows the inner end of the locking rod 13 to insert into the annular locking groove 15. This allows the locking mechanism 9 to firmly fix the position of the valve shaft 7, thereby directly preventing the axial movement of the valve shaft 7. The valve shaft 7 is fixedly connected to the diaphragm 3, locking the position of the diaphragm 3. Even if the handwheel 6 is accidentally touched, the valve stem 4 and the valve shaft 7 will not move axially, thus eliminating the risk of unexpected changes in the valve opening. When unlocking, rotating the operating ring 14 disengages the inner end of the locking rod 13 from the annular locking groove 15, restoring the freedom of movement of the valve shaft 7 and allowing it to operate normally. This design can lock the diaphragm 3 valve when it needs to be closed for a long time, preventing accidental contact that could lead to a safety accident.

[0040] As attached Figure 4 and attached Figure 5As shown, the locking mechanism 9 also includes a number of first springs 16 and transmission balls 17 equal to the number of locking rods 13. A guide hole 18 is radially provided on the outer periphery of the locking sleeve 12. The locking rod 13 is movably disposed within the guide hole 18. A guide flange 19 is provided on the outer periphery of the locking rod 13, and the outer circular surface of the guide flange 19 is in contact with the inner circular surface of the guide hole 18. A limiting flange 20 is provided at the inner end of the guide hole 18, and the inner circular surface of the limiting flange 20 is in contact with the outer circular surface of the locking rod 13. The first springs 16 are clamped in the guide... Between flange 19 and limiting flange 20, the transmission ball 17 is rolled between locking rod 13 and operating ring 14. The inner circular surface of operating ring 14 is provided with an arc-shaped groove 61 for the transmission ball 17 to partially extend into. The arc-shaped groove 61 includes groove 1 21 and groove 22. The depth of groove 22 is greater than the depth of groove 1 21. Groove 1 21 and groove 22 are connected by guide inclined surface 23. When the transmission ball 17 switches between groove 1 21 and groove 22, the inner end of locking rod 13 inserts into or disengages from annular locking groove 15. When the transmission ball 17 switches between groove 1 21 and groove 22, the inner end of locking rod 13 correspondingly inserts into or disengages from annular locking groove 15. The groove design with different depths not only triggers the movement of locking rod 13, but also provides clear tactile feedback (resistance difference) in the locked state. The operator can clearly perceive the position, thereby effectively suppressing the risk of misoperation, especially ensuring the long-term stability of valve locking under high pressure conditions.

[0041] As attached Figure 4 As shown, the valve body 1 has a mounting groove 24 at its bottom. The upper end of the locking sleeve 12 is threaded into the mounting groove 24, meaning the inner surface of the mounting groove 24 has an internal thread. The outer circumference of the locking sleeve 12 has an external thread that matches the internal thread. The lower end of the locking sleeve 12 has a hexagonal operating part 25 with a hexagonal outer contour. The locking sleeve 12 can be rotated by operating the hexagonal operating part 25 with a wrench. A first retaining spring 26 is respectively engaged at the upper and lower ends of the operating ring 14 on the outer circumference of the locking sleeve 12. This design allows for the fixed installation of the locking sleeve 12 and the rotating installation of the operating ring 14. The installation structure is simple and reliable, and disassembly and assembly are very convenient.

[0042] As attached Figure 6As shown, the interlocking mechanism 8 includes an interlocking ring 27 and at least one transmission rod 28. The interlocking ring 27 is sleeved on the outer periphery of the upper end of the valve stem 4. A second retaining ring 29 is respectively engaged at the upper and lower ends of the valve stem 4 corresponding to the interlocking ring 27. The interlocking ring 27 has a radially openable outer hole 30, and the valve shaft 7 has a corresponding movable inner hole 31 on its side. The transmission rod 28 is radially movable within the movable outer hole 30 and the movable inner hole 31. The lower end of the valve stem 4 has a mating sleeve 62, which is sleeved on the outer periphery of the interlocking ring 27. The inner circular surface of the mating sleeve 62 has an annular interlocking groove 32. When the transmission rod 28 moves, it has an interlocking position where its outer end is inserted into the interlocking groove 32 and a disengaged position where its outer end is disengaged from the interlocking groove 32. This design can achieve a locking connection between the valve stem 4 and the valve shaft 7, realizing their axial linkage.

[0043] As attached Figure 6 As shown, the interlocking mechanism 8 also includes an interlocking rod 33 and a second spring 34. A guide hole 35 extends upward from the center of the lower end of the valve shaft 7, but the guide hole 35 does not penetrate the upper end of the valve shaft 7. The movable inner hole 31 communicates with the guide hole 35. The interlocking rod 33 is partially vertically movable within the guide hole 35, and the lower end of the interlocking rod 33 is always located outside the guide hole 35. A deep annular groove 36 and a shallow annular groove 37 are sequentially arranged vertically along the outer periphery of the interlocking rod 33. A tapered guide surface 38 is provided between the deep annular groove 36 and the shallow annular groove 37. A first annular flange 39 is provided on the outer periphery of the transmission rod 28, and the outer surface of the first annular flange 39 is parallel to the outer surface of the transmission rod 28. The inner circular surface of the movable outer hole 30 is in contact with the outer circular surface of the movable outer hole 30. The inner end of the movable outer hole 30 is provided with a second annular flange 40. A limit ring 41 is fixedly installed at the outer end of the movable outer hole 30. The inner circular surfaces of the second annular flange 40 and the limit ring 41 are in contact with the outer circular surface of the transmission rod 28. The second spring 34 is clamped between the limit ring 41 and the first annular flange 39. When the interlocking rod 33 moves vertically, the inner end of the transmission rod 28 switches between the annular deep groove 36 and the annular shallow groove 37. When the inner end of the transmission rod 28 is inserted into the annular shallow groove 37, the transmission rod 28 is in the interlocked position. When the inner end of the transmission rod 28 is inserted into the annular deep groove 36, the transmission rod 28 is in the disengaged position. The interlocking rod 33 is introduced, which allows for external operation of locking or unlocking between the valve stem 4 and the valve shaft 7. That is, by pulling down the interlocking rod 33, the transmission rod 28 disengages from the interlocking groove 32 of the docking sleeve 62, thereby separating the valve stem 4 and the valve shaft 7. At the same time, rotating the operating ring 14 locks the valve shaft 7. The valve cover 2, valve stem 4 and handwheel 6 can be disassembled online to replace damaged parts, thus supporting online maintenance without stopping the machine and avoiding impact on production efficiency.

[0044] As attached Figure 6As shown, the upper end of the guide hole 35 is provided with an exhaust hole 42 extending to the outside of the valve shaft 7. The exhaust hole 42 includes an axial hole and a radial hole that are interconnected. When the interlocking rod 33 moves up and down in the guide hole 35, the internal air can flow freely through the exhaust hole 42, avoiding the large operating resistance or jamming caused by air compression.

[0045] As attached Figures 8-10 As shown, the diaphragm valve 3 also includes a pressure ring 43, which is connected to the valve body 1 by multiple first screws 44. The upper end of the pressure ring 43 has a relief groove 45 for the screw heads of the first screws 44 to be inserted. The diaphragm 3 is sandwiched between the valve body 1 and the valve cover 2. The lower end of the pressure ring 43 also has multiple hexagonal grooves 46, in which multiple hexagonal nuts 47 are embedded. Multiple second screws 48 pass through the valve cover 2, and the second screws 48 pass through the pressure ring 43 and are threaded into the corresponding hexagonal nuts 47. In this embodiment, there are three first screws 44 and three second screws 48, and they are staggered. When maintaining the valve cover 2, valve stem 4, and handwheel 6, because the pressure ring 43 presses the diaphragm 3 tightly onto the valve body 1, even if the valve cover 2, valve stem 4, and handwheel 6 are disassembled, the sealing of the diaphragm 3 will not be affected, making maintenance very convenient.

[0046] As attached Figure 11 As shown, the diaphragm 3 has a cylindrical fixing part 49 in the middle. The valve shaft 7 passes through the fixing part 49 from top to bottom. The fixing part 49 has a through hole for the valve shaft 7 to pass through. The valve shaft 7 has an annular positioning protrusion 50 on its outer periphery. The fixing part 49 has an annular positioning cavity 51 that matches the annular positioning protrusion 50. The valve shaft 7 is threaded with a locking nut 52 at the upper and lower ends of the fixing part 49, respectively. That is, the valve shaft 7 has a screw part at the upper and lower ends of the fixing part 49, and the two locking nuts 52 are respectively abutted against the upper and lower ends of the fixing part 49. The support platform 10 also has a clearance recess 53 for the fixing part 49 and the locking nut 52 to be inserted. Tightening the two locking nuts 52 not only locks the annular positioning protrusion 50 on the valve shaft 7 to the fixing part 49, but also applies positive pressure to the fixing part 49 on the annular positioning protrusion 50, which can improve the sealing between the two and prevent the internal medium from leaking from the gap between them.

[0047] As attached Figure 12As shown, the inner end of the recessed portion 53 is also provided with a threaded groove 54 coaxial with the shaft hole 11. A sealing sleeve 55 is threadedly connected to the threaded groove 54. The outer circumference of the sealing sleeve 55 has an external thread that mates with the threaded groove 54. A sealing gasket 56 is sandwiched between the sealing sleeve 55 and the threaded groove 54. A first sealing ring 57 for forming a sealing fit with the outer circumference of the valve shaft 7 is also provided on the inner circular surface of the sealing sleeve 55. A plurality of second sealing rings 58 for forming a sealing fit with the inner circular surface of the guide hole 35 are provided on the outer circular surface of the interlocking rod 33. This design can ensure the sealing between the outer circular surface of the valve shaft 7 and the inner circular surface of the shaft hole 11, and between the outer circular surface of the interlocking rod 33 and the inner circular surface of the guide hole 35, preventing leakage of the internal medium.

[0048] In addition, as attached Figure 1 As shown, the inner wall of the valve cover 2 is provided with multiple vertically extending guide grooves 59, and the mating sleeve 62 is provided with guide blocks 60 that cooperate with the guide grooves 59. The guide blocks 60 and the mating sleeve 62 are an integral structure. The mating sleeve 62 is circumferentially limited so that it can only perform stable axial movement and will not rotate.

Claims

1. A diaphragm valve with a locking function, comprising a valve body (1), a valve cover (2) mounted on the upper end of the valve body (1), a diaphragm (3) sandwiched between the valve body (1) and the valve cover (2), a valve stem (4) penetrating the valve cover (2) and connected to the diaphragm (3), a valve stem nut (5) rotatably disposed on the upper end of the valve cover (2) and threadedly engaged with the valve stem (4), and a handwheel (6) circumferentially mounted on the outer periphery of the thread of the valve stem (4); characterized in that: It also includes a valve shaft (7), an interlocking mechanism (8), and a locking mechanism (9). The valve shaft (7) penetrates the diaphragm (3) vertically and is fixedly connected to the middle of the diaphragm (3). A support platform (10) is provided inside the valve body (1). A shaft hole (11) for the lower end of the valve shaft (7) to pass through is provided vertically on the support platform (10). The lower end of the valve stem (4) is connected to the upper end of the valve shaft (7) through the interlocking mechanism (8). The locking mechanism (9) is located at the lower end of the valve body (1) corresponding to the shaft hole (11). The locking mechanism (9) includes a locking sleeve. 12) A plurality of locking rods (13) are radially movably arranged on the locking sleeve (12) and an operating ring (14) is rotatably arranged on the outer periphery of the locking sleeve (12) and linked with the locking rods (13). The valve shaft (7) is provided with an annular locking groove (15) near the lower end on the outer periphery. When the valve rod (4) drives the valve shaft (7) to move to the lower limit position, the lower end of the valve shaft (7) extends into the locking sleeve (12). When the operating ring (14) is rotated, the locking rod (13) has a locking position in which the inner end is inserted into the annular locking groove (15) and an unlocking position in which the inner end is disengaged from the annular locking groove (15).

2. A diaphragm valve with a locking function according to claim 1, characterized in that: The locking mechanism (9) also includes a number of first springs (16) equal to the number of locking rods (13) and transmission balls (17). The locking sleeve (12) has a guide hole (18) that runs radially through its outer periphery. The locking rod (13) is movably disposed within the guide hole (18). The locking rod (13) has a guide flange (19) on its outer periphery. The outer circular surface of the guide flange (19) is in contact with the inner circular surface of the guide hole (18). The inner end of the guide hole (18) has a limiting flange (20). The inner circular surface of the limiting flange (20) is in contact with the outer circular surface of the locking rod (13). The first springs (16) are clamped in the guide flange (19). Between the limiting flange (20) and the transmission ball (17), the transmission ball (17) is rolled between the locking rod (13) and the operating ring (14). The inner circular surface of the operating ring (14) is provided with an arc-shaped groove (61) for the transmission ball (17) to partially extend into. The arc-shaped groove (61) includes a groove one (21) and a groove two (22). The depth of the groove two (22) is greater than the depth of the groove one (21). The groove one (21) and the groove two (22) are connected by a guide inclined surface (23). When the transmission ball (17) switches between the groove one (21) and the groove two (22), the inner end of the locking rod (13) is inserted into or disengaged from the annular locking groove (15).

3. A diaphragm valve with a locking function according to claim 1, characterized in that: The valve body (1) has a mounting groove (24) at the bottom. The upper end of the locking sleeve (12) is threaded into the mounting groove (24). The lower end of the locking sleeve (12) has a hexagonal operating part (25) with a hexagonal outer contour. A first snap ring (26) is respectively engaged at the upper and lower ends of the operating ring (14) on the outer periphery of the locking sleeve (12).

4. A diaphragm valve with a locking function according to claim 1, characterized in that: The interlocking mechanism (8) includes an interlocking ring (27) and at least one transmission rod (28). The interlocking ring (27) is sleeved on the outer periphery of the upper end of the valve stem (4). A second retaining ring (29) is respectively engaged at the upper and lower ends of the valve stem (4). The interlocking ring (27) has a movable outer hole (30) radially opened. The valve shaft (7) has a movable inner hole (31) on its side corresponding to the movable outer hole (30). The transmission rod (28) is radially movable in the movable outer hole (30) and the movable inner hole (31). The lower end of the valve stem (4) is provided with a docking sleeve (62). The docking sleeve (62) is sleeved on the outer circumference of the interlocking ring (27). The inner circular surface of the docking sleeve (62) is provided with an annular interlocking groove (32). When the transmission rod (28) moves, it has an interlocking position where the outer end is inserted into the interlocking groove (32) and a separation position where the outer end is disengaged from the interlocking groove (32).

5. A diaphragm valve with a locking function according to claim 4, characterized in that: The interlocking mechanism (8) also includes an interlocking rod (33) and a second spring (34). A guide hole (35) is provided at the center of the lower end of the valve shaft (7) extending upward, and the guide hole (35) does not penetrate the upper end of the valve shaft (7). The movable inner hole (31) is connected to the guide hole (35). The interlocking rod (33) is partially vertically movable in the guide hole (35), and the lower end of the interlocking rod (33) is always located outside the guide hole (35). An annular deep groove (36) and an annular shallow groove (37) are provided vertically along the outer periphery of the interlocking rod (33). A tapered guide surface (38) is provided between the annular deep groove (36) and the annular shallow groove (37). A first annular flange (39) is provided on the outer periphery of the transmission rod (28). The outer circular surface of the first annular flange (39) is parallel to the outer surface of the transmission rod (28). The inner circular surface of the movable outer hole (30) is in contact with each other. The inner end of the movable outer hole (30) is provided with a second annular flange (40). The outer end of the movable outer hole (30) is fixedly installed with a limiting ring (41). The inner circular surfaces of the second annular flange (40) and the limiting ring (41) are in contact with the outer circular surface of the transmission rod (28). The second spring (34) is sandwiched between the limiting ring (41) and the first annular flange (39). When the interlocking rod (33) moves vertically, the inner end of the transmission rod (28) switches between the annular deep groove (36) and the annular shallow groove (37). When the inner end of the transmission rod (28) is inserted into the annular shallow groove (37), the transmission rod (28) is in the interlocked position. When the inner end of the transmission rod (28) is inserted into the annular deep groove (36), the transmission rod (28) is in the separated position.

6. A diaphragm valve with a locking function according to claim 5, characterized in that: The upper end of the guide hole (35) is provided with an exhaust hole (42) extending to the outside of the valve shaft (7).

7. A diaphragm valve with a locking function according to claim 5, characterized in that: It also includes a pressure ring (43), which is connected to the valve body (1) by a plurality of first screws (44). The upper end of the pressure ring (43) is provided with a relief groove (45) for the screw head of the first screw (44) to be inserted. The diaphragm (3) is sandwiched between the valve body (1) and the valve cover (2). The lower end of the pressure ring (43) is also provided with a plurality of hexagonal grooves (46), in which a plurality of hexagonal nuts (47) are embedded. A plurality of second screws (48) are passed through the valve cover (2), and the second screws (48) pass through the pressure ring (43) and are threadedly engaged with the corresponding hexagonal nuts (47).

8. A diaphragm valve with a locking function according to claim 5, characterized in that: The diaphragm (3) has a cylindrical fixing part (49) in the middle. The valve shaft (7) passes through the fixing part (49) from top to bottom. The valve shaft (7) has an annular positioning protrusion (50) on its outer periphery. The fixing part (49) has an annular positioning cavity (51) that matches the annular positioning protrusion (50). The valve shaft (7) is threaded with a locking nut (52) at the upper and lower ends of the fixing part (49) respectively. The two locking nuts (52) abut against the upper and lower ends of the fixing part (49) respectively. The support platform (10) also has a clearance recess (53) for the fixing part (49) and the locking nut (52) to be inserted.

9. A diaphragm valve with a locking function according to claim 8, characterized in that: The inner end of the recess (53) is also provided with a threaded groove (54) coaxial with the shaft hole (11). A sealing sleeve (55) is threadedly connected in the threaded groove (54). A sealing gasket (56) is sandwiched between the sealing sleeve (55) and the threaded groove (54). A first sealing ring (57) for forming a sealing fit with the outer surface of the valve shaft (7) is also provided on the inner circular surface of the sealing sleeve (55). A plurality of second sealing rings (58) for forming a sealing fit with the inner circular surface of the guide hole (35) are provided on the outer circular surface of the interlocking rod (33).

10. A diaphragm valve with a locking function according to claim 4, characterized in that: The valve cover (2) has a plurality of vertically extending guide grooves (59) on its inner wall, and the mating sleeve (62) has guide blocks (60) that cooperate with the guide grooves (59).

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