Diaphragm valve

Abstract

The invention relates to a diaphragm valve, and relates to the technical field of valves. The diaphragm valve comprises a valve body, a mounting cavity is formed in the valve body, and a piston assembly and an elastic piece for pushing the piston assembly to move in the mounting cavity are arranged in the mounting cavity; a fluid inlet channel and a fluid outlet channel are formed in the valve body. The fluid inlet channel is communicated with the fluid outlet channel; a diaphragm is arranged between the fluid inlet channel and the fluid outlet channel in the valve body; the piston assembly moves to push the diaphragm to deform so as to block communication between the fluid inlet channel and the fluid outlet channel. A limiting adjusting structure used for adjusting the reset position of the piston assembly is further arranged in the valve body. The CV value of the diaphragm valve can be conveniently and rapidly adjusted, the CV value can be changed according to the requirements of customers, and the requirements of the same product of the customers for different CV values are met.

Description

Technical Field

[0001] The present application relates to the field of valve technology, and in particular to a diaphragm valve. Background Art

[0002] As an important fluid control device, the diaphragm valve controls the opening and closing of the valve through the deformation of the diaphragm; the diaphragm not only separates the medium from the atmosphere, but also adjusts the opening of the valve through its own deformation. The diaphragm valve has the characteristics of good sealing, high reliability, small dead zone, and wide application range. Therefore, it has been widely used. For example, in high-purity gas systems, diaphragm valves can effectively isolate the medium from the atmosphere to prevent pollution. At the same time, its structural design and material selection also ensure its stability and durability in high pressure, vacuum, high and low temperature environments. The application of diaphragm valves is not limited to engine systems, but is also widely used in other industrial and scientific fields that require precise control and isolation. For example, in the semiconductor and photovoltaic industries, diaphragm valves are used for the shut-off function of high-temperature gases.

[0003] With the development of semiconductor and photovoltaic material manufacturing technology, the performance requirements for diaphragm valves are getting higher and higher. Sometimes it is necessary to accurately control the gas flow through the diaphragm valve. The CV value (Circulation Volume) of the valve is an important parameter to measure the valve's circulation capacity. It is defined as the volume flow rate of the pipeline medium flowing through the valve per unit time and under constant pressure. Correctly calculating and selecting the CV value is an important step to ensure the normal operation of the pipeline flow control system. The larger the flow coefficient value, the smaller the pressure loss when the fluid flows through the valve, and the greater the valve's circulation capacity.

[0004] Reference Figure 1 As shown, the diaphragm valve in the related art includes a valve body 10, a piston assembly 20 located in the valve body 10, and a diaphragm 30; the valve body 10 is provided with a fluid inlet channel 111 and a fluid outlet channel 112 that are connected to each other, and a connecting cavity 113 for installing the diaphragm 30 is provided in the valve body 10 between the fluid inlet channel 11 and the fluid outlet channel 12, and the piston assembly 20 pushes the diaphragm 30 to deform to block the connection between the fluid inlet channel 111 and the fluid outlet channel 112; in order to ensure the sealing performance, a sealing assembly 40 composed of a plurality of sealing rings is provided between the piston assembly 20 and the inner wall of the valve body 10.

[0005] The diaphragm valve in the related technology only has a shut-off function, and it is difficult to accurately control the gas flow through the diaphragm valve, and the CV value cannot be adjusted according to customer needs; if the CV value needs to be changed, another valve can only be replaced, and the installation dimensions cannot be guaranteed to be interchangeable, which is not convenient to use. Summary of the invention

[0006] In order to facilitate the adjustment of the CV value of a diaphragm valve, the present application provides a diaphragm valve.

[0007] The diaphragm valve provided in this application adopts the following technical solution: A diaphragm valve comprises a valve body, wherein the valve body is provided with an installation cavity, wherein the installation cavity is provided with a piston assembly and an elastic member for pushing the piston assembly to move in the installation cavity; A fluid inlet channel and a fluid outlet channel are respectively provided in the valve body; the fluid inlet channel and the fluid outlet channel are connected; A diaphragm is disposed in the valve body between the fluid inlet channel and the fluid outlet channel; the movement of the piston assembly can push the diaphragm to deform so as to block the communication between the fluid inlet channel and the fluid outlet channel; The valve body is also provided with a limit adjustment structure for adjusting the reset position of the piston assembly.

[0008] When in use, high-temperature gas or other fluid enters the valve body from the fluid inlet channel, and under the action of the elastic member, the piston assembly is pushed to move in the installation cavity, thereby pushing the diaphragm to deform, blocking the channel between the fluid inlet channel and the fluid discharge channel, prohibiting their connection, and realizing the closure of the valve; when the valve needs to be opened, the gas in the valve body, or other methods are provided to provide external force to overcome the elastic force of the elastic member, at this time, the piston assembly moves in the opposite direction, the diaphragm recovers its deformation under the action of its own elastic force, opens the channel between the fluid inlet channel and the fluid discharge channel, and the fluid can be discharged smoothly from the fluid discharge channel. In the present application, a limit adjustment structure is set in the valve body, and the limit adjustment structure can limit the limit position of the piston assembly when it is reset. The limit position of the piston assembly is adjusted by the limit adjustment structure, thereby controlling the degree of recovery of the deformation of the diaphragm under the action of its own elastic force, that is, the opening and closing size when it opens the valve port, thereby adjusting the fluid flow rate flowing through the diaphragm valve.

[0009] By adopting the above-mentioned technical scheme, the diaphragm valve in the present application can utilize the limit adjustment structure to change the reset limit position of the piston assembly, thereby realizing precise control of the degree of deformation of the diaphragm and realizing the adjustable CV value function of the diaphragm valve. The CV value of the valve can be flexibly adjusted according to the different needs of customers. It is very convenient to use and avoids the problem of installation dimension mismatch caused by the need to replace the valve to adjust the CV value, thereby improving the convenience and reliability of the use of the diaphragm valve.

[0010] Optionally, the valve body includes a mother body, a cylinder lower cover and a cylinder upper cover; the mother body is fixedly connected to one end of the cylinder lower cover, and the cylinder upper cover is detachably fixed to the other end of the cylinder lower cover and is used to close the port of the installation cavity; the two ends of the elastic member act on the inner side surface of the cylinder upper cover and the piston assembly respectively; the limit adjustment structure is arranged on the cylinder upper cover.

[0011] By adopting the above technical solution, the assembly of the entire valve components is facilitated, and the limit adjustment structure is arranged on the cylinder cover, which is convenient for flexible adjustment, maintenance and replacement, and can also facilitate the transformation of the existing diaphragm valve.

[0012] Optionally, the inner side surface of the cylinder upper cover has a mounting cylinder facing the interior of the mounting cavity, and the piston assembly includes a first piston slidably arranged in the mounting cavity; the first piston includes a first piston rod and a first piston disk fixed at the end of the first piston rod, and the first piston rod is slidably inserted in the mounting cylinder; the limit adjustment structure is arranged in the mounting cylinder to limit the position of the first piston rod.

[0013] By adopting the above technical solution, a mounting cylinder facing the inside of the mounting cavity is provided on the inner side surface of the cylinder upper cover, and a limit adjustment structure is provided in the mounting cylinder to limit the position of the first piston rod, thereby realizing precise limit control of the reset position of the piston assembly, and then accurately adjusting the opening degree and CV value of the diaphragm valve, which is stable and reliable.

[0014] Optionally, a first sealing ring is arranged between the outer circumferential surface of the first piston rod and the cavity wall of the mounting tube, and a gasket is also arranged in the mounting tube, the gasket is arranged on the first piston rod and the gasket is located between the first sealing ring and the first piston disk; a second sealing ring is arranged between the outer circumferential surface of the first piston disk and the cavity wall of the mounting cavity.

[0015] By adopting the above technical solution, the sealing performance of the first piston is improved, while the stability and reliability of the operation of the first piston is ensured.

[0016] Optionally, the limit adjustment structure includes a gasket that can be placed in the mounting tube, and the inner wall of the mounting tube has a limit portion. When the gasket is placed in the mounting tube, one side of the gasket abuts against the limit portion, and the other side abuts against the end face of the first piston rod. The limit position of the first piston rod can be adjusted by replacing gaskets of different thickness specifications or increasing or decreasing the number of gaskets in the mounting tube.

[0017] By adopting the above technical solution, by replacing gaskets of different thickness specifications or increasing or decreasing the number of gaskets, the limit position of the first piston rod can be flexibly adjusted to achieve accurate control of the CV value. The operation is convenient and the transformation cost is low.

[0018] Optionally, the outer periphery of the inner side surface of the cylinder upper cover has a connecting sleeve facing the cylinder lower cover, and one end of the cylinder lower cover facing the cylinder upper cover is detachably connected to the connecting sleeve through threaded cooperation or detachably connected through a clamping structure; The end of the cylinder lower cover facing the mother body is provided with a connecting tube, a locking nut is threadedly connected to the connecting tube, and the locking nut can be threadedly connected to the mother body so that the mother body and the connecting tube are fixedly connected through the locking nut.

[0019] By adopting the above technical solution, the cylinder upper cover and the cylinder lower cover are detachably connected through threaded cooperation or a clamping structure, which is convenient for the assembly and maintenance of the diaphragm valve; at the same time, the cylinder lower cover and the mother body are fixedly connected by a locking nut, which ensures the structural stability of the entire diaphragm valve and improves the service life of the valve.

[0020] Optionally, the mounting tube has a mounting hole along its axial direction and the mounting hole passes through the outer side surface of the cylinder upper cover; the limit adjustment structure includes an adjusting screw threaded in the mounting hole, and the end face of the first piston rod extending into the mounting tube abuts against the inner end face of the adjusting screw.

[0021] By adopting the above technical solution, the setting of the adjusting screw realizes the precise control of the position of the end face of the first piston rod, thereby precisely adjusting the reset position of the piston assembly, and further realizing the precise control of the CV value of the diaphragm valve. The adjusting screw is directly screwed through the mounting hole from the outer side of the cylinder cover using a tool, without disassembling the cylinder cover of the diaphragm valve, which is convenient for operation.

[0022] Optionally, the piston assembly also includes a second piston slidably disposed in the mounting cavity, and the second piston is disposed on a side of the first piston away from the cylinder cover; the second piston includes a second piston rod and a second piston disk fixed in the middle of the second piston rod, one end of the second piston rod abuts against the first piston disk, and the other end of the second piston rod extends toward the direction of the diaphragm.

[0023] By adopting the above technical solution, the normal opening and closing of the valve is ensured, and more labor is saved.

[0024] Optionally, a connecting cavity and a piston gasket are provided on the mother body, the fluid inlet channel and the fluid outlet channel are respectively connected to the connecting cavity, the diaphragm is installed in the connecting cavity and the diaphragm can be abutted against the connection between the fluid inlet channel and the connecting cavity and block the port of the fluid inlet channel, a third piston is provided on the side of the diaphragm away from the fluid inlet channel, the third piston is slidably arranged in the middle of the piston gasket, and the end of the second piston rod is connected to or abuts against the third piston.

[0025] By adopting the above technical solution, the deformation ability and sealing effect of the diaphragm are further enhanced, ensuring the stability and reliability of the valve.

[0026] Optionally, the port through which the fluid inlet channel communicates with the connecting cavity is located in the middle of the bottom of the connecting cavity, and the port through which the fluid outlet channel communicates with the connecting cavity is located on one side of the bottom of the connecting cavity; an annular groove is provided around the port of the fluid inlet channel in the middle of the bottom of the connecting cavity, an annular sealing gasket is embedded in the annular groove, and the side of the diaphragm can be sealed against the side of the annular sealing gasket.

[0027] By adopting the above technical solution, the side of the diaphragm can be abutted and sealed against the side of the annular sealing gasket, thereby improving the sealing performance of the diaphragm valve in a closed state and reducing leakage.

[0028] Optionally, the second piston rod passes through the connecting tube and a third sealing ring is provided between the outer circumferential surface of the second piston rod and the inner wall of the connecting tube; A fourth piston is also sleeved on the second piston rod, and the fourth piston is located between the first piston disc and the second piston disc; a fourth sealing ring is arranged between the outer circumferential surface of the second piston disc and the wall of the installation cavity, and a fifth sealing ring is arranged between the outer circumferential surface of the fourth piston and the wall of the installation cavity; a sixth sealing ring is arranged on the inner wall of the second piston rod and the fourth piston.

[0029] By adopting the above technical solution, the sealing performance of the diaphragm valve is further improved.

[0030] In summary, the present application includes at least one of the following beneficial technical effects: 1. The CV value of the diaphragm valve in this application can be adjusted quickly and easily, and the CV value can be changed according to customer needs to meet the customer's needs for different CV values ​​for the same product, thereby improving the flexibility of valve use.

[0031] 2. The diaphragm valve in the present application can be improved on the basis of the existing ordinary diaphragm valve, and the modification cost is low.

[0032] 3. The diaphragm valve in the present application uses a gasket or an adjusting screw structure to limit the limit position of the piston assembly, which is very convenient for adjustment. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 It is a schematic diagram of the cross-sectional structure of a diaphragm valve in the related art.

[0034] Figure 2 It is a schematic diagram of the cross-sectional structure of the diaphragm valve in Example 1 of the present application.

[0035] Figure 3 yes Figure 2 Schematic diagram of the local enlarged structure at point A in the middle.

[0036] Figure 4It is a schematic diagram of the cross-sectional structure of the diaphragm valve in Example 2 of the present application.

[0037] Figure 5 yes Figure 4 Schematic diagram of the local enlarged structure at point B in the middle.

[0038] In the figure: 10. Valve body; 11. Mother body; 111. Fluid inlet channel; 112. Fluid outlet channel; 113. Communication chamber; 114. Annular groove; 12. Cylinder lower cover; 121. Installation chamber; 122. Connecting tube; 13. Cylinder upper cover; 131. Installation tube; 1311. Positioning part; 1312. Installation hole; 132. Connecting sleeve; 14. Locking nut; 20. Piston assembly; 21. First piston; 211. First piston rod; 212. First piston disc; 22. Second piston; 221. Second piston rod; 222. Second piston disc; 23. Fourth piston; 30. Diaphragm; 40. Sealing assembly; 41. First sealing ring; 42. Second sealing ring; 43. Third sealing ring; 44. Fourth sealing ring; 45. Fifth sealing ring; 46. Sixth sealing ring; 50. Third piston; 60. Elastic parts; 70. Limit adjustment structure; 71. Gasket; 72. Adjustment screw; 80. Ring-shaped sealing gasket; 90. Piston gasket; 100. Cushion cover. DETAILED DESCRIPTION

[0039] The following will be combined with the attached Figure 2 -Attached Figure 5 , the technical solutions in the embodiments of the present invention are clearly and completely described. The described embodiments are only possible technical implementations of the present invention, not all possible implementations. Those skilled in the art can completely combine the embodiments of the present invention to obtain other embodiments without creative work, and these embodiments are also within the scope of protection of the present invention.

[0040] Example 1 Reference Figure 2 and Figure 3As shown, the diaphragm valve provided in the embodiment of the present application includes a valve body 10, and the valve body 10 includes a mother body 11, a cylinder lower cover 12 and a cylinder upper cover 13; the left and right ends of the mother body 11 are respectively provided with a fluid inlet channel 111 and a fluid outlet channel 112. The cylinder lower cover 12 is cylindrical, one end of which is connected to the mother body 11, and the other end is connected to the cylinder upper cover 13. Specifically, the cylinder lower cover 12 has a connecting cylinder 122 at one end facing the mother body 11, and a locking nut 14 is screwed on the connecting cylinder 122. One side of the mother body 11 has a boss, and the two ends of the locking nut 14 are respectively screwed with the connecting cylinder 122 and the boss, so that the mother body 11 and the cylinder lower cover 12 are fixedly connected through the locking nut 14. The outer periphery of the inner side surface of the cylinder upper cover 13 is provided with a connecting sleeve 132 facing the cylinder lower cover 12, and one end of the cylinder lower cover 12 facing the cylinder upper cover 13 is detachably connected to the connecting sleeve 132 through threaded matching or detachably connected through a clamping structure. In this embodiment, as a solution, the outer periphery of the connecting sleeve 132 is provided with an external thread, and the cylinder lower cover 12 is provided with an internal thread matching the external thread, and the connecting sleeve 132 is inserted into the cylinder lower cover 12, and the two are threadedly connected through the external thread and the internal thread.

[0041] As an alternative, a key is provided on the outer circumference of the connecting sleeve 132 of the cylinder upper cover 13, and a clamping hole matching the key is provided on the cylinder lower cover 12. The connecting sleeve 132 is inserted into the cylinder lower cover 12, and the key is embedded in the clamping hole to achieve clamping of the two. When disassembly is required, the key is pressed by a tool to disengage it from the clamping hole, and the connecting sleeve 132 can be pulled out from the cylinder lower cover 12, and the cylinder upper cover 13 can be removed.

[0042] The detachable connection structure between the cylinder upper cover 13 and the cylinder lower cover 12 facilitates the assembly and maintenance of the diaphragm valve; at the same time, the cylinder lower cover 12 is fixedly connected to the mother body 11 by a locking nut 14, which ensures the structural stability of the entire diaphragm valve and improves the service life of the valve.

[0043] Reference Figure 2 and Figure 3 As shown, the cylinder lower cover 12 has an installation cavity 121, and the cylinder upper cover 13 can close the port of the installation cavity 121; the installation cavity 121 is provided with a piston assembly 20 and an elastic member 60 for pushing the piston assembly 20 to move in the installation cavity 121; in this embodiment, the elastic member 60 is a coil spring, and the two ends of the elastic member 60 act on the inner side surface of the cylinder upper cover 13 and the piston assembly 20 respectively.

[0044] Reference Figure 2 and Figure 3As shown, the inner side surface of the cylinder cover 13 is provided with a mounting cylinder 131 facing the inside of the mounting cavity 121, and the piston assembly 20 includes a first piston 21 slidably arranged in the mounting cavity 121; the first piston 21 includes a first piston rod 211 and a first piston disc 212 fixedly arranged at the end of the first piston rod 211, and the first piston rod 211 is slidably inserted in the mounting cylinder 131; the elastic member 60 is sleeved outside the mounting cylinder 131, one end of the elastic member 60 abuts against the inner side surface of the cylinder cover 13, and the other end abuts against the side surface of the first piston disc 212. A first sealing ring 41 is arranged between the outer peripheral surface of the first piston rod 211 and the cavity wall of the mounting cylinder 131, and a gasket 100 is also arranged in the mounting cylinder 131, and the gasket 100 is sleeved on the first piston rod 211 and is located between the first sealing ring 41 and the first piston disc 212; a second sealing ring 42 is arranged between the outer peripheral surface of the first piston disc 212 and the cavity wall of the mounting cavity 121.

[0045] Reference Figure 2 As shown, the piston assembly 20 also includes a second piston 22 slidably disposed in the mounting cavity 121, and the second piston 22 is disposed on a side of the first piston 21 away from the cylinder upper cover 13; the second piston 22 includes a second piston rod 221 and a second piston disk 222 fixed in the middle of the second piston rod 221, and one end of the second piston rod 221 abuts against the first piston disk 212.

[0046] Reference Figure 2As shown, a connecting chamber 113 and a piston gasket 90 are provided on the boss of the mother body 11, and the fluid inlet channel 111 and the fluid outlet channel 112 are respectively connected to the connecting chamber 113; specifically, the port for connecting the fluid inlet channel 111 with the connecting chamber 113 is located in the middle of the bottom of the connecting chamber 113, and the port for connecting the fluid outlet channel 112 with the connecting chamber 113 is located on one side of the bottom of the connecting chamber 113; an annular groove 114 is provided on the periphery of the port of the fluid inlet channel 111 in the middle of the bottom of the connecting chamber 113, and an annular sealing gasket 80 is embedded in the annular groove 114, and the outer periphery of the piston gasket 90 is fixedly connected to the boss of the mother body 11 by a locking nut 14. A diaphragm 30 is arranged in the communication chamber 113 between the fluid inlet channel 111 and the fluid outlet channel 112; the outer periphery of the diaphragm 30 is clamped and fixed on the side wall of the communication chamber 113 by the piston gasket 90, and the side of the diaphragm 30 can be abutted against the side of the annular sealing gasket 80 to seal and block the port of the fluid inlet channel 111, and a third piston 50 is arranged on the side of the diaphragm 30 away from the fluid inlet channel 111, and the third piston 50 is slidably arranged in the middle of the piston gasket 90, and the other end of the second piston rod 221 extends toward the diaphragm 30, and the second piston rod 221 passes through the connecting cylinder 122 and the second piston rod 221 passes through the connecting cylinder 122. A third sealing ring 43 is provided between the outer circumferential surface of the plug rod 221 and the inner wall of the connecting tube 122; the end of the second piston rod 221 is connected to or abuts against the third piston 50, the elastic member 60 pushes the first piston 21 to move, the first piston 21 pushes the second piston 22 to move, the second piston rod 221 of the second piston 22 moves and pushes the third piston 50 to move, the third piston 50 can push the diaphragm 30 to deform and abut against the side of the annular sealing gasket 80 to seal the port for blocking the fluid inlet channel 111, thereby blocking the connection between the fluid inlet channel 111 and the fluid outlet channel 112.

[0047] Reference Figure 3 As shown, a limit adjustment structure 70 is provided in the mounting cylinder 131. When the first piston 21 is reset, the limit adjustment structure 70 is used to limit the position of the first piston rod 211. Specifically, in this embodiment, the limit adjustment structure 70 includes a gasket 71 placed in the mounting cylinder 131. The inner wall of the mounting cylinder 131 has a limit portion 1311. The limit portion 1311 can be a flat step surface or a conical step surface, or can be the bottom surface of a blind hole set in the mounting cylinder 131. When the gasket 71 is placed in the mounting cylinder 131, one side of the gasket 71 abuts against the limit portion 1311, and the other side abuts against the end surface of the first piston rod 211. The limit position of the first piston rod 211 can be adjusted by replacing gaskets 71 of different thickness specifications or increasing or decreasing the number of gaskets 71 in the mounting cylinder 131. Thus, accurate control of the CV value is achieved, the operation is convenient, and the modification cost is low.

[0048] Reference Figure 2As shown, in this embodiment, the second piston rod 221 is also sleeved with a fourth piston 23, and the fourth piston 23 is located between the first piston disc 212 and the second piston disc 222; a fourth sealing ring 44 is provided between the outer circumference of the second piston disc 222 and the cavity wall of the installation cavity 121, and a fifth sealing ring 45 is provided between the outer circumference of the fourth piston 23 and the cavity wall of the installation cavity 121; a sixth sealing ring 46 is provided on the inner wall of the second piston rod 221 and the fourth piston 23. The above-mentioned multiple sealing rings form a sealing assembly 40 to improve the sealing performance of the diaphragm valve.

[0049] The implementation principle of this embodiment is as follows: when in use, a fluid such as a high-temperature gas enters the valve body 10 from the fluid inlet channel 111, and under the action of the elastic member 60, the piston assembly 20 is pushed to move in the installation cavity 121, thereby pushing the diaphragm 30 to deform, thereby blocking the channel between the fluid inlet channel 111 and the fluid outlet channel 112, prohibiting the communication between them, and achieving valve closure; when the valve needs to be opened, gas is injected into the valve body 10, or an external force is provided in other ways to overcome the elastic force of the elastic member 60. At this time, the piston assembly 20 moves in the opposite direction, and the diaphragm 30 recovers its deformation under the action of its own elastic force, thereby opening the channel between the fluid inlet channel 111 and the fluid outlet channel 112, and the fluid can be discharged smoothly from the fluid outlet channel 112. In the present application, a limit adjustment structure 70 is set in the valve body 10, and the limit adjustment structure 70 can limit the limit position of the piston assembly 20 when it is reset. The limit position of the piston assembly 20 is adjusted by the limit adjustment structure 70, thereby controlling the degree to which the diaphragm 30 recovers its deformation under the action of its own elastic force, that is, the opening and closing size when it opens the valve port, thereby adjusting the fluid flow rate flowing through the diaphragm valve.

[0050] The diaphragm valve in the present application can utilize the limit adjustment structure 70 to change the reset limit position of the piston assembly 20, thereby achieving precise control of the deformation degree of the diaphragm 30, realizing the adjustable CV value function of the diaphragm valve, and can flexibly adjust the CV value of the valve according to the different needs of customers. It is very convenient to use and avoids the problem of installation size mismatch caused by the need to replace the valve to adjust the CV value, thereby improving the convenience and reliability of the use of the diaphragm valve.

[0051] Example 2 Reference Figure 3 and Figure 4 As shown, this embodiment is substantially the same as the embodiment 1, except that, in this embodiment, the mounting tube 131 has a mounting hole 1312 along its axial direction and the mounting hole 1312 penetrates to the outer side surface of the cylinder upper cover 13; the limit adjustment structure 70 includes an adjusting screw 72 threaded in the mounting hole 1312, the adjusting screw 72 may be a hexagonal countersunk screw, and the end surface of the first piston rod 211 extending into the mounting tube 131 abuts against the inner end surface of the adjusting screw 72.

[0052] The implementation principle of this embodiment is: use a tool to directly screw the adjusting screw 72 through the mounting hole 1312 from the outer side of the cylinder cover 13, and the position of the adjusting screw 72 can be adjusted without disassembling the cylinder cover 13 of the diaphragm valve, thereby conveniently and quickly realizing precise control of the end face position of the first piston rod 211 and precise regulation of the CV value of the diaphragm valve.

[0053] The embodiments of this specific implementation are all preferred embodiments of the present application, and are not intended to limit the protection scope of the present application. The same components are represented by the same figure marks. Therefore, any equivalent changes made based on the structure, shape, and principle of the present application should be included in the protection scope of the present application.

Claims

1. A diaphragm valve, comprising a valve body (10), wherein a mounting cavity (121) is arranged in the valve body (10), wherein a piston assembly (20) and an elastic member (60) for pushing the piston assembly (20) to move in the mounting cavity (121) are arranged in the mounting cavity (121); A fluid inlet channel (111) and a fluid outlet channel (112) are respectively provided in the valve body (10); the fluid inlet channel (111) and the fluid outlet channel (112) are connected; It is characterized in that A diaphragm (30) is provided in the valve body (10) between the fluid inlet channel (111) and the fluid outlet channel (112); the movement of the piston assembly (20) can push the diaphragm (30) to deform so as to block the communication between the fluid inlet channel (111) and the fluid outlet channel (112); A limit adjustment structure (70) for adjusting the reset position of the piston assembly (20) is also provided in the valve body (10).

2. The diaphragm valve according to claim 1, characterized in that The valve body (10) comprises a main body (11), a cylinder lower cover (12) and a cylinder upper cover (13); the main body (11) is fixedly connected to one end of the cylinder lower cover (12), and the cylinder upper cover (13) is detachably fixedly connected to the other end of the cylinder lower cover (12) and is used to close the port of the installation cavity (121); the two ends of the elastic member (60) act on the inner side surface of the cylinder upper cover (13) and the piston assembly (20) respectively; the limit adjustment structure (70) is arranged on the cylinder upper cover (13).

3. The diaphragm valve according to claim 2, characterized in that: The inner side surface of the cylinder upper cover (13) is provided with a mounting tube (131) facing the inside of the mounting cavity (121); the piston assembly (20) includes a first piston (21) slidably arranged in the mounting cavity (121); the first piston (21) includes a first piston rod (211) and a first piston disc (212) fixed at the end of the first piston rod (211); the first piston rod (211) is slidably inserted in the mounting tube (131); the limit adjustment structure (70) is arranged in the mounting tube (131) to limit the position of the first piston rod (211).

4. The diaphragm valve according to claim 3, characterized in that: A first sealing ring (41) is arranged between the outer circumferential surface of the first piston rod (211) and the cavity wall of the mounting tube (131); a gasket (100) is also arranged in the mounting tube (131); the gasket (100) is sleeved on the first piston rod (211) and the gasket (100) is located between the first sealing ring (41) and the first piston disc (212); a second sealing ring (42) is arranged between the outer circumferential surface of the first piston disc (212) and the cavity wall of the mounting cavity (121).

5. The diaphragm valve according to claim 3, characterized in that: The limit adjustment structure (70) comprises a gasket (71) that can be placed in the mounting tube (131), and the inner wall of the mounting tube (131) is provided with a limit portion (1311). When the gasket (71) is placed in the mounting tube (131), one side of the gasket (71) abuts against the limit portion (1311), and the other side abuts against the end face of the first piston rod (211). The limit position of the first piston rod (211) can be adjusted by replacing gaskets (71) of different thickness specifications or increasing or decreasing the number of gaskets (71) in the mounting tube (131).

6. The diaphragm valve according to claim 2, 3, 4 or 5, characterized in that: The outer periphery of the inner side surface of the cylinder upper cover (13) is provided with a connecting sleeve (132) facing the cylinder lower cover (12); one end of the cylinder lower cover (12) facing the cylinder upper cover (13) is detachably connected to the connecting sleeve (132) through threaded engagement or detachably connected through a clamping structure; The cylinder lower cover (12) has a connecting tube (122) at one end facing the mother body (11), and a locking nut (14) is threadedly connected to the connecting tube (122). The locking nut (14) can be threadedly connected to the mother body (11) so that the mother body (11) and the connecting tube (122) are fixedly connected via the locking nut (14).

7. The diaphragm valve according to claim 3, characterized in that: The mounting tube (131) has a mounting hole (1312) along its axial direction, and the mounting hole (1312) penetrates to the outer side surface of the cylinder upper cover (13); the limit adjustment structure (70) includes an adjustment screw (72) screwed into the mounting hole (1312), and the end surface of the first piston rod (211) extending into the mounting tube (131) abuts against the inner end surface of the adjustment screw (72).

8. The diaphragm valve according to claim 3, 4, 5 or 7, characterized in that: The piston assembly (20) further comprises a second piston (22) slidably disposed in the mounting cavity (121), wherein the second piston (22) is disposed on a side of the first piston (21) away from the cylinder upper cover (13); the second piston (22) comprises a second piston rod (221) and a second piston disc (222) fixedly disposed in the middle of the second piston rod (221), wherein one end of the second piston rod (221) abuts against the first piston disc (212), and the other end of the second piston rod (221) extends in the direction of the diaphragm (30).

9. The diaphragm valve according to claim 8, characterized in that The mother body (11) is provided with a connecting cavity (113) and a piston gasket (90); the fluid inlet channel (111) and the fluid outlet channel (112) are respectively connected to the connecting cavity (113); the diaphragm (30) is installed in the connecting cavity (113) and the diaphragm (30) can be abutted against the connection between the fluid inlet channel (111) and the connecting cavity (113) and block the port of the fluid inlet channel (111); a third piston (50) is provided on the side of the diaphragm (30) away from the fluid inlet channel (111); the third piston (50) is slidably arranged in the middle of the piston gasket (90); and the end of the second piston rod (221) is connected to or abuts against the third piston (50).

10. The diaphragm valve according to claim 9, characterized in that The port through which the fluid inlet channel (111) communicates with the connecting chamber (113) is located in the middle of the bottom of the connecting chamber (113), and the port through which the fluid outlet channel (112) communicates with the connecting chamber (113) is located on one side of the bottom of the connecting chamber (113); an annular groove (114) is provided in the middle of the bottom of the connecting chamber (113) around the port of the fluid inlet channel (111), and an annular sealing gasket (80) is embedded in the annular groove (114), and the side surface of the diaphragm (30) can be abutted and sealed against the side surface of the annular sealing gasket (80).

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