Diaphragm valve

Abstract

The utility model provides a diaphragm valve, which comprises a valve body, a valve core, a valve core, a valve core, a valve core, a valve core and a valve core body, and is characterized in that the valve body is internally provided with a runner and a valve seat; the cover body is fixedly mounted on the valve body and is positioned on one side of the opening of the valve body; the diaphragm is mounted between the cover body and the valve body and seals the opening; the diaphragm comprises a valve element, a deformation part and a sealing part. The sealing part is fixedly connected with the valve body in a sealed mode. The driving assembly is installed in the cover body and comprises a valve rod, and one end of the valve rod is connected with the valve element through a connecting part; the valve element is provided with a sealing end and a mounting end which are oppositely arranged. The valve rod further comprises an abutting wall arranged around the connecting part. The diaphragm valve further comprises a protection part, the protection part surrounds the outer side of the connecting part, the two opposite sides of the protection part abut against the mounting end and the abutting wall respectively, the contact area of the protection part and the mounting end is larger than the cross section area of the valve rod, and the hardness of the protection part is larger than that of the valve element. And the sealing performance of the valve core and the valve seat is improved.

Description

Technical Field

[0001] This utility model relates to the technical field of valves, and in particular to a diaphragm valve. Background Technology

[0002] A diaphragm valve typically includes a valve body, a diaphragm structure, and a drive assembly. The valve body includes a flow channel and a valve seat that separates the flow channel. The diaphragm structure divides the interior of the valve body into a fluid side and a non-fluid side. The diaphragm typically includes a valve core, a deformation part, and a sealing part. The valve core is used to cooperate with the valve seat. The deformation part is arranged around the valve core and connects the valve core and the sealing part. The sealing part is sealed to the valve body. The drive assembly is located in the non-fluid side and has a valve shaft for driving the valve core to reciprocate, so as to realize the valve core abutting or disconnecting from the valve seat, thereby realizing the conduction or cut-off of fluid in the flow channel.

[0003] However, for larger diaphragm valves, the pressure exerted on the valve core by the fluid is greater than that on smaller diaphragm valves. This requires the valve core to exert greater contact force with the valve seat to ensure that it can seal the valve seat and thus cut off the fluid flow in the flow channel. In addition, to ensure a good enough seal, the valve core of current diaphragm valves is generally made of corrosion-resistant materials such as rubber or resin. These corrosion-resistant materials are prone to deformation under large forces, which will affect the sealing effect at the valve seat. Summary of the Invention

[0004] The technical problem to be solved by this utility model is to overcome the defects in the prior art, thereby providing a diaphragm valve. To achieve the above objective, this utility model adopts the following technical solution:

[0005] A diaphragm valve, comprising:

[0006] The valve body has a flow channel inside and a valve seat that divides the flow channel, and the valve body has an opening that communicates with the flow channel.

[0007] The cover is fixedly installed with the valve body and located on one side of the valve body opening;

[0008] A diaphragm is installed between the cover and the valve body and seals the opening; the diaphragm includes a valve core, a deformable part surrounding the outer periphery of the valve core, and a sealing part surrounding the outer periphery of the deformable part, the sealing part being sealed and fixedly connected to the valve body;

[0009] A drive assembly is installed in the cover. The drive assembly includes a valve stem, one end of which is connected to the valve core via a connecting part to control the movement of the valve core.

[0010] The valve core has a sealing end and a mounting end that are disposed opposite to each other. The sealing end can seal the valve seat to isolate the flow channel, and the mounting end is connected to the connecting part.

[0011] The valve stem also includes an abutment wall surrounding the connecting portion;

[0012] The diaphragm valve also includes:

[0013] The protective component surrounds the outside of the connecting part. The opposite sides of the protective component abut against the mounting end and the abutment wall, respectively. The contact area between the protective component and the mounting end is greater than the cross-sectional area of ​​the valve stem, and the hardness of the protective component is greater than the hardness of the valve core.

[0014] In the above solution, by setting up a protective component, the force between the contact wall and the mounting end can be transferred more evenly, thus preventing the force from concentrating on one point of the valve core and causing it to easily deform. Especially when the valve core abuts against the valve seat, to ensure sufficient force between the valve core and the valve seat to maintain a seal and thus isolate the flow path (i.e., close the valve body), the force exerted by the valve shaft on the valve core is relatively large. Therefore, the protective component disperses this force, preventing force concentration on the inner side of the valve core, which could easily lead to valve core deformation and seal failure between the valve core and the valve seat.

[0015] Preferably, the portion of the sealing end that can abut against the valve seat is the abutment portion; in the horizontal projection, the projection of the portion of the protective member that abuts against the mounting end covers the projection of the abutment portion.

[0016] In the above solution, this arrangement allows for coverage directly above the contact area. When the valve seat is closed, the valve stem, through the protective element, applies pressure to the valve core directly above the contact area, ensuring sufficient force between the valve core and the valve seat. Without the protective element, the pressure concentrates at the center of the valve core and is transmitted through it to the contact area, making the valve core more prone to deformation.

[0017] Preferably, the protective component includes an axial limiting part and a radial limiting part that are fixedly connected to each other; wherein, the axial limiting part is disposed between the mounting end and the abutment wall, and the radial limiting part is arranged around the outer periphery of the valve core near the mounting end.

[0018] In the above scheme, the inner wall surface of the radial limiting part is used to radially limit the side wall surface of the valve core, thereby preventing the valve core from undergoing radial deformation due to large axial pressure. At this time, the radial limiting part can be interference-fitted on the outer periphery of the mounting end, or it can be fitted to the outer periphery of the mounting end, or there can be a small gap between the radial limiting part and the outer periphery of the mounting end.

[0019] Preferably, the radial limiting portion has a reinforcing inclined surface disposed toward the deformable portion, and the reinforcing inclined surface gradually increases in size along its outer radial direction.

[0020] In the above solution, the reinforced slope increases the structural strength of the radial limiting part by increasing its thickness, thus preventing radial deformation of the valve core. Furthermore, it further prevents interference between the radial limiting part and the deformable part. Simultaneously, the reinforced slope also supports the deformable part when it is under excessive pressure, preventing excessive deformation.

[0021] Preferably, the connection between the valve core and the deformable part has an anti-interference gap with the radial limiting part.

[0022] In the above solution, by setting an anti-interference gap, it is possible to avoid the bottom end of the radial limiting part from abutting against the valve core and the connection of the deformation part, thus preventing stress concentration at the connection.

[0023] Preferably, the bottom end of the cover is provided with a support slope for supporting the deformable part, and a chamfer is provided at the connection between the axial limiting part and the radial limiting part.

[0024] In the above solution, when the fluid pressure is too high, the support slope can support the deformed part to avoid damage to the deformed part due to excessive fluid pressure; at the same time, the chamfered part can prevent interference between the connection between the axial limiting part and the radial limiting part and the support slope, and can also prevent stress concentration of the protective part at the connection between the axial limiting part and the radial limiting part.

[0025] Preferably, below the connection between the deformed part and the valve core, the outer wall surface of the valve core is set as a frustum-shaped surface, and the outer diameter gradually increases from the abutment part upwards.

[0026] In the above scheme, the setting of the frustum surface can increase the structural strength of the entire valve core and prevent deformation when the valve core and valve seat come into contact; on the other hand, it can also play a guiding role.

[0027] Preferably, the deformable part and the sealing part have an upper connecting part located at the upper side connection and a lower connecting part located at the lower side connection; wherein the upper connecting part is located radially inside the lower connecting part.

[0028] The above technical solution can increase the width of the connection between the deformable part and the sealing part; and when the deformable part is deformed upward by the fluid force, the upper connection part can resist the upward deformation of the lower connection part, thereby better distributing the stress at the lower connection part and avoiding excessive stress concentration at the lower connection part, which would make the lower connection part easy to be damaged.

[0029] Preferably, the sealing end has a downwardly protruding protrusion at its bottom center; and / or, the sealing end has an annular groove, the annular groove being at least partially opposite to the valve seat wall, and the abutting part being located outside the annular groove.

[0030] In the above scheme, the thickness of the bottom end of the sealing end can be increased by the protrusion, so that the sealing end is more difficult to deform downward. At the same time, the protrusion can also play a certain role in guiding the flow. The area of ​​the contact part can be reduced by the setting of the annular groove, thereby improving the sealing effect. Moreover, compared with the annular protrusion structure set at the sealing end, the annular groove will not hinder the flow of fluid.

[0031] Preferably, the connecting part is a first threaded post protruding downward from the valve stem, and the mounting end is provided with a first threaded groove that mates with the first threaded post; or, the connecting part is a second threaded groove provided on the valve stem, and the mounting end is provided with a second threaded post protruding upward and mates with the second threaded groove.

[0032] Compared with the prior art, the beneficial effects of this utility model are as follows:

[0033] 1. By incorporating a protective component, the force between the contact wall and the mounting end can be transmitted more evenly, preventing the force from concentrating in the center of the valve core and causing it to deform easily. Especially when the valve core abuts against the valve seat, to ensure sufficient force for sealing, the valve shaft exerts a significant force on the valve core. Therefore, the protective component disperses this force across the area where the mounting end abuts the protective component, preventing excessive local pressure on the valve core caused by force concentration, which could lead to valve core deformation and seal failure between the valve core and valve seat.

[0034] 2. By abutting the inner wall of the radial limiting part against the side wall of the valve core (actually against the extension of the valve core), a radial supporting force can be generated on the top of the valve core, preventing the valve core from undergoing radial deformation due to large axial pressure.

[0035] 3. The reinforced slope increases the structural strength of the radial limiting part, preventing radial deformation of the valve core. It also further prevents interference between the radial limiting part and the deformable part. Furthermore, the reinforced slope supports the deformable part when it is under excessive pressure, preventing excessive deformation. Attached Figure Description

[0036] To more clearly illustrate the specific embodiments of this utility model or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0037] Figure 1 This is a front view (section) provided in the first embodiment of the present invention.

[0038] Figure 2 for Figure 1 An enlarged diagram of position D1.

[0039] Figure 3 for Figure 1 A schematic diagram of the diaphragm structure.

[0040] Figure 4 for Figure 2 An enlarged view of position D2 in the middle.

[0041] Explanation of reference numerals in the attached figures:

[0042] 1. Valve body; 11. Flow channel; 12. Valve seat; 2. Cover; 3. Diaphragm; 31. Valve core; 311. Sealing end; 3111. Abutment part; 3112. Protrusion part; 3113. Annular groove; 312. Mounting end; 313. Extension part; 32. Deformation part; 33. Sealing part; 4. Drive assembly; 41. Valve stem; 412. Abutment wall; 42. Connecting part; 421. First threaded post; 422. First threaded groove; 42. Piston; 43. Air chamber structure; 44. Receiving cavity; 45. Spring; 46. First air port; 47. Second air port; 5. Protective component; 51. Axial limiting part; 52. Radial limiting part; 521. Reinforcing inclined surface; 6. Upper connecting part; 7. Lower connecting part; 10. Anti-interference gap; 20. Supporting inclined surface; 30. Chamfered part; 40. Frustum-shaped surface. Detailed Implementation

[0043] The technical solution of this utility model will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this utility model. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model.

[0044] In the description of this utility model, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0045] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0046] See Figures 1 to 4 This utility model provides a diaphragm valve, including a valve body 1, a cover 2, a diaphragm 3, and a drive assembly 4.

[0047] Specifically, the valve body 1 has a flow channel 11 and a valve seat 12 that divides the flow channel 11 inside, and an opening communicating with the flow channel 11 is provided on the valve body 1. The cover 2 is fixedly installed on the valve body 1 and is located on one side of the opening of the valve body 1. The diaphragm 3 is installed between the cover 2 and the valve body 1 and is provided to seal the opening. The diaphragm 3 includes a valve core 31, a deformable part 32 arranged around the outer periphery of the valve core 31, and a sealing part 33 arranged around the outer periphery of the deformable part 32. The sealing part 33 is sealed and fixedly connected to the valve body 1. The drive assembly 4 is installed in the cover 2.

[0048] The drive assembly 4 includes a valve stem 41, one end of which is connected to the valve core 31 via a connecting part 42, for controlling the movement of the valve core 31. Figure 1 As shown, the drive assembly 4 also includes a piston 42 connected to the valve stem 41, an air chamber structure 43 located below the piston 42, and a receiving cavity 44 located at the top of the piston 42. A spring 45 cooperating with the piston 42 is disposed inside the receiving cavity 44. A first air port 46 is provided in the air chamber structure 43, which is connected to an external air source to change the air pressure inside the air chamber structure 43 through the first air port 46. A second air port 47 is provided in the receiving cavity 44 to balance the air pressure between the receiving cavity 44 and the outside environment.

[0049] In the above structure, piston 42 is subjected to the downward elastic force of spring 45 and the upward gas pressure inside the gas chamber structure 43. Thus, when the gas pressure inside the gas chamber structure 43 is changed, the force balance of piston 42 changes, and the up-and-down movement of piston 42 can be controlled, which in turn drives valve core 42 to move up and down through valve stem 41.

[0050] In other embodiments, the spring may be located at the bottom of the piston, and the air chamber structure may be located at the top of the piston; or, the drive assembly may use a threaded connection structure to control the up and down movement of the valve stem manually or by a motor or other structure.

[0051] The valve core 31 has a sealing end 311 and a mounting end 312 disposed opposite to each other. The sealing end 311 can seal the valve seat 12 to isolate the flow channel 11, and the mounting end 312 is connected to the connecting part 42. Figure 1 as well as Figure 2 As shown, the inner side of the valve seat 12 has a flow channel structure. When the valve stem 41 applies a downward force to the center of the mounting end 312 so that the sealing end 311 abuts against the valve seat 12, thereby isolating the flow channel 11, the force of the valve stem 41 on the valve core 31 will be concentrated in the middle of the valve core 31. Furthermore, the center of the bottom end of the valve core 31 is opposite to the flow channel structure, meaning that the center of the bottom end of the valve core 31 is unsupported. The force of the valve stem 41 on the valve core 31 will easily cause the center of the sealing end 311 of the valve core 31 to deform downward, which in turn will cause the part of the sealing end 311 that abuts against the valve seat 12 to easily deform, thus affecting the sealing effect between the sealing end 311 and the valve seat 12.

[0052] It is worth noting that, for ease of description, this embodiment uses... Figure 1 The upper part of the diaphragm valve is positioned below the azimuth valve. Figure 1 The lower part of the diaphragm valve is defined as the lower part of the valve, with the side relatively closer to the central axis of the valve stem 41 as the inner side and the side relatively farther away from the central axis as the outer side.

[0053] See Figure 1 and Figure 2 To prevent deformation of the valve core 31 from affecting its sealing with the valve seat 12, the diaphragm valve also includes a protective element 5, and the valve stem 41 also includes an abutment wall 412 surrounding the connecting portion 42.

[0054] Specifically, the protective element 5 surrounds the outside of the connecting portion 42, and the opposite sides of the protective element 5 abut against the mounting end 312 and the abutment wall 412, respectively, as detailed in the following reference. Figure 2 as well as Figure 3 The upper side of the protective element 5 abuts against the abutting wall 412, and the lower side of the protective element 5 abuts against the mounting end 312. The contact area between the protective element 5 and the mounting end 312 is greater than the cross-sectional area of ​​the valve stem 41, and the hardness of the protective element 5 is greater than the hardness of the valve core 31.

[0055] It is easy to understand that by setting the protective component 5, the force between the contact wall 412 and the mounting end 312 can be transmitted more evenly, so as to avoid the force being concentrated in one place on the valve core 31, which would make the valve core 31 easy to deform. Especially when the valve core 31 abuts against the valve seat 12, in order to ensure that there is a sufficient force between the valve core 31 and the valve seat 12 to ensure a seal, the force exerted by the valve shaft on the valve core 31 is relatively large. Therefore, the protective component 5 disperses the force, thereby avoiding excessive local pressure on the valve core 31 caused by force concentration, which would make the valve core 31 easy to deform and cause the seal between the valve core 31 and the valve seat 12 to fail. At the same time, the protective component 5 supports the diaphragm 3, thereby preventing the diaphragm 3 from being deformed upward by the scouring force of the fluid, and further preventing the valve core 31 from deforming and affecting its sealing effect on the valve seat 12.

[0056] In addition, when the valve core 31 is separated from the valve seat 12 to allow fluid to flow, the protective member 5 can support the valve core 31 to prevent the valve core 31 from being deformed by the scouring force of the fluid, and further prevent the valve core 31 from being deformed and affecting its sealing effect on the valve seat 12.

[0057] When the valve body is closed, the force is concentrated on the abutment part 3111 and above it. On the horizontal plane, the projection of the protective member 5 and the mounting end 312 abutting part covers the projection of the abutment part 3111, thus covering the area directly above it. This allows the protective member 5 to transfer the force to the abutment part 3111 and above it during use, preventing excessive force on the inner side of the abutment part 3111 from causing deformation and affecting its sealing effect.

[0058] See Figure 2 and Figure 3 The protective component 5 includes an axial limiting part 51 and a radial limiting part 52 that are fixedly connected to each other; wherein, the axial limiting part 51 is disposed between the mounting end 312 and the abutment wall 412, and the radial limiting part 52 is arranged around the outer periphery of the valve core 31 near the mounting end 312.

[0059] It is easy to understand that one end face of the axial limiting part 51 abuts against a partial end face of the mounting end 312, and the other end face abuts against the abutment wall 412, which can increase the force-bearing area of ​​the mounting end 312, thereby effectively preventing the valve core 31 from undergoing axial deformation. The radial limiting part 52 extends downward from the edge of the axial limiting part 51 and forms the inner wall surface of the radial limiting part 52. The inner wall surface of the radial limiting part 52 can restrict the radial outward deformation of the extension part 313 extending upward from the upper end of the valve core 31. Thus, when the top end of the valve core 31 deforms radially, the radial limiting part 52 will generate a radial support force on the top end of the valve core 31, preventing the valve core 31 from undergoing radial deformation due to large axial pressure.

[0060] See Figure 2 and Figure 3 The radial limiting portion 52 has a reinforcing inclined surface 521 disposed toward the deformable portion 32, and the reinforcing inclined surface 521 gradually increases in size along its outer radial direction. Specifically, in Figure 2 In this design, as the reinforcing inclined surface 521 moves upward, its outer diameter also gradually increases; that is, the higher the reinforcing inclined surface 521 is, the larger its diameter. This structure increases the structural strength of the radial limiting part 52, preventing radial deformation of the valve core 31. Furthermore, it further prevents interference between the radial limiting part 52 and the deformable part 32. Simultaneously, the reinforcing inclined surface 521 also supports the deformable part 32 when it is under excessive pressure, preventing excessive deformation.

[0061] Furthermore, at the connection between the valve core 31 and the deformation part 32, there is an anti-interference gap 10 between the radial limiting part 52 and the connection between the valve core 31 and the deformation part 32. The anti-interference gap 10 can prevent the bottom end of the radial limiting part 52 from interfering with the connection between the valve core 31 and the deformation part 32, and prevent stress concentration at the connection, which in turn can easily lead to deformation and damage of the structure.

[0062] Furthermore, the bottom end of the cover 2 is provided with a support slope 20 to support the deformable part 32. When the fluid pressure is too high, the support slope 20 supports the deformable part 32, preventing excessive deformation under pressure and thus avoiding damage to the deformable part 32. A chamfer 30 is provided at the connection between the axial limiting part 51 and the radial limiting part 52. The support slope 20 and the chamfer 30 prevent interference between the connection between the axial limiting part 51 and the radial limiting part 52 and the support slope 20. Simultaneously, stress concentration in the protective member 5 is avoided, thus ensuring that the protective member 5 itself is not easily deformed.

[0063] Furthermore, below the connection between the deformable part 32 and the valve core 31, the outer wall surface of the valve core 31 is set as a frustum 40, and the outer diameter gradually increases from the abutment part 3111 upwards; this setting can increase the structural strength of the entire valve core 31 on the one hand, and prevent the valve core 31 from deforming when it abuts the valve seat 12; on the other hand, it can play a guiding role.

[0064] See Figure 2 and Figure 3 To increase the stability of the connection between the valve stem 41 and the valve core 31, the connecting part 42 is a first threaded post 421 protruding downward from the valve stem 41, and the mounting end 312 is provided with a first threaded groove 422 that mates with the first threaded post 421. Of course, in other embodiments, the connecting part 42 may also be a second threaded groove provided on the valve stem 41, and the mounting end 312 may be provided with a second threaded post that protrudes upward and mates with the second threaded groove.

[0065] Furthermore, to increase the stability of the connection between the first threaded post 421 and the first threaded groove 422, an extension 313 is provided at the top of the valve core 31. The extension 313 effectively increases the axial length of the valve core 31, thereby increasing the axial depth of the first threaded groove 422 and further increasing the stability of the connection between the first threaded post 421 and the first threaded groove 422. Of course, in other embodiments, the connecting part 42 can also be configured as an expansion rod and an expansion hole. In this case, the extension 313 can increase the contact area between the expansion rod and the expansion hole, thereby increasing the stability of the connection between the two.

[0066] It is easy to understand that when the extension 313 increases the overall axial length of the valve core 31, the valve stem 41 applies force to drive the valve core 31 to seal with the valve seat 12, which can easily cause radial deformation at the upper end of the valve core 31, thereby affecting the sealing effect between the valve core 31 and the valve seat 12. The radial limiting part 52 can generate radial support force on the extension 313, thereby effectively preventing deformation at the upper end of the valve core 31 and ensuring the sealing performance between the valve core 31 and the valve seat 12.

[0067] Furthermore, it should be understood that since the frustum surface 40 extends both radially and axially, if the radial extension of the frustum surface 40 is too long while the axial extension is relatively small, the radial and axial thickness ratio of the valve core 31 will increase, thereby affecting the stability of the connection between the valve stem 41 and the valve core 31. This solution increases the stability of the connection between the valve stem 41 and the valve core 31 by threading them together (i.e., through the first threaded post 421 and the first threaded groove 422), and facilitates their assembly and disassembly. At the same time, the upper end of the valve core 31 is also provided with an extension 313, which can reduce the radial and axial thickness ratio of the valve core 31 to a certain extent, increase the deformation resistance of the valve core 31, and increase the stability of the connection between the valve stem 41 and the valve core 31. The extension 313 and the radial limiting part 52 abut against each other, which can also achieve radial support for the valve core 31 and prevent the valve core 31 from deforming.

[0068] See Figure 1 as well as Figure 4 Between the deformable part 32 and the sealing part 33, there is an upper connecting part 6 located at the upper side connection and a lower connecting part 7 located at the lower side connection; wherein, the upper connecting part 6 is located radially inside the lower connecting part 7, thereby increasing the thickness of the connection between the deformable part 32 and the sealing part 33; and when the deformable part 32 is deformed upward by the fluid force, the upper connecting part 6 can resist the upward deformation of the lower connecting part 7, thereby achieving better distribution of stress at the lower connecting part 7, thereby avoiding the deformable part 32 from deforming upward and causing excessive stress on the lower connecting part 7 when the fluid pressure is too high, which would easily lead to damage.

[0069] Furthermore, see 2 and Figure 3 The sealing end 311 has a downwardly protruding portion 3112 at its bottom center, which increases the thickness of the sealing end 311 and makes the valve core 31 less prone to downward deformation under force, thus improving the structural strength of the valve core 31. Furthermore, the apex of the protrusion 3112 is located on the central axis of the valve seat 12, and the protrusion 3112 extends from the apex to the periphery in a conical surface (i.e., the protrusion 3112 extends from the apex towards the valve seat 12 port located away from the central axis), thereby achieving a fluid guiding effect.

[0070] Furthermore, the sealing end 311 is provided with an annular groove 3113, which is at least partially opposite to the wall of the valve seat 12, and the abutment portion 3111 is located outside the annular groove 3113, thereby reducing the area of ​​the abutment portion 3111 and improving the sealing effect between the valve core 31 and the valve seat 12.

[0071] Meanwhile, the annular groove 3113 can reduce the area of ​​the contact portion 3111 and will not interfere with the flow of fluid. For example, when the contact portion 3111 is a raised annular structure, the contact portion 3111 will interfere with the flow of fluid, causing strong turbulence to occur when the fluid passes through the contact portion 3111.

[0072] The above embodiments are merely preferred embodiments of this utility model and should not be construed as limiting the scope of protection of this utility model. Any non-substantial changes and substitutions made by those skilled in the art based on this utility model shall fall within the scope of protection claimed by this utility model.

Claims

1. A diaphragm valve, comprising: a valve body, inside which a flow channel and a valve seat are arranged, and on which an opening is arranged in communication with the flow channel; a cover body, which is fixedly arranged on the valve body and located on one side of the opening of the valve body; a diaphragm, which is arranged between the cover body and the valve body and seals the opening; the diaphragm comprises a valve core, a deformation portion arranged around the outer circumferential side of the valve core, and a sealing portion arranged around the outer circumferential side of the deformation portion, and the sealing portion is sealingly and fixedly connected with the valve body; a driving assembly, which is arranged in the cover body, and comprises a valve stem, one end of the valve stem is connected with the valve core through a connecting portion, so as to control the movement of the valve core; wherein the valve core has oppositely arranged sealing end and mounting end, the sealing end can seal the valve seat to cut off the flow channel, and the mounting end is connected with the connecting portion; characterized in that: the valve stem comprises an abutting wall arranged around the connecting portion; the diaphragm valve further comprises: a protection piece, which is arranged around the outer side of the connecting portion, and the opposite sides of the protection piece are respectively arranged in abutment with the mounting end and the abutting wall, the contact area between the protection piece and the mounting end is greater than the cross-sectional area of the valve stem, and the hardness of the protection piece is greater than the hardness of the valve core.

2. The diaphragm valve of claim 1, wherein the part of the sealing end capable of abutting against the valve seat is an abutting portion; in the horizontal plane projection, the projection of the abutting portion of the protection piece and the mounting end covers the projection of the abutting portion.

3. The diaphragm valve of claim 1, wherein the protection piece comprises an axial limiting portion and a radial limiting portion which are fixedly connected with each other; wherein the axial limiting portion is arranged between the mounting end and the abutting wall, and the radial limiting portion is annularly arranged on the outer circumferential side of the valve core close to the mounting end.

4. The diaphragm valve of claim 3, wherein the radial limiting portion has a reinforcing inclined surface arranged towards the deformation portion, and the outer diameter of the reinforcing inclined surface gradually increases.

5. The diaphragm valve of claim 3, wherein the connecting portion between the valve core and the deformation portion and the radial limiting portion has an anti-interference gap.

6. The diaphragm valve of claim 3, wherein the bottom end of the cover body is provided with a supporting inclined surface for supporting the deformation portion, and the connecting portion between the axial limiting portion and the radial limiting portion is provided with a chamfered portion.

7. The diaphragm valve of claim 2, wherein, below the connecting portion between the deformation portion and the valve core, the outer wall surface of the valve core is arranged as a conical frustum surface, and gradually increases from the abutting portion upwards.

8. The diaphragm valve of claim 1, wherein, between the deformation portion and the sealing portion, there are an upper connecting portion located at the upper side connecting portion and a lower connecting portion located at the lower side connecting portion; wherein the upper connecting portion is located radially inside the lower connecting portion.

9. The diaphragm valve of claim 2, wherein, a convex portion is arranged at the center of the bottom end of the sealing end and protrudes downwards; and / or, the sealing end is provided with an annular groove, which is at least partially arranged opposite to the valve seat wall surface, and the abutting portion is located outside the annular groove.

10. The diaphragm valve according to any one of claims 1 to 9, characterized in that the connecting portion is a first threaded column protruding downwards from the valve stem, and the mounting end is provided with a first threaded groove matched with the first threaded column; or, the connecting portion is a second threaded groove arranged on the valve stem, and the mounting end is provided with a second threaded column protruding upwards and matched with the second threaded groove.

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