Diaphragm valve

Abstract

An annular supporting portion is arranged in a concave portion of a valve body, the annular supporting portion protrudes out of the inner bottom face of the concave portion, a certain distance exists between the annular supporting portion and a chamfer existing between the inner side wall and the inner bottom face of the concave portion, and the outer edge of a diaphragm is located on the annular supporting portion and does not make contact with the chamfer. It is guaranteed that the diaphragm can be tightly attached to the annular supporting part under the effect of pressing the joint piece, and sealing is formed; at the moment, the side face of the outer edge of the diaphragm can abut against or make contact with the inner side wall of the concave part, the inner side wall of the concave part plays a role in radial limiting, it is guaranteed that the outer edge of the diaphragm is located between the pressing joint piece and the annular supporting part, and then fixing and sealing of the diaphragm are guaranteed; in addition, compared with the original inner bottom surface of the concave part, the stress area of the annular supporting part is smaller, so that the outer edge of the diaphragm is easier to seal and fix, and the sealing effect is better.

Description

Technical Field

[0001] The utility model relates to the technical field of valve bodies, and particularly relates to a diaphragm valve. Background Art

[0002] A modular gas supply system (IGS) is a device used for gas control in the semiconductor industry. As semiconductor manufacturing processes become more and more advanced, the requirements for gas control equipment are also getting higher and higher. The modular gas supply system adopts a combination (like building blocks) of flow path blocks and fluid controllers, etc. to form at least one pipeline on a substrate, and is modularly designed. While reducing the volume of the equipment, the installation and maintenance become simpler instead.

[0003] For example, existing fluid control devices / systems include at least one pipeline, and each pipeline includes several fluid controllers and flow rate blocks. Among them, the fluid controllers can be pneumatic diaphragm valves, manual diaphragm valves, etc. The valves are mainly used to control the on / off of process gases in the pipeline.

[0004] The existing diaphragm valve generally includes a valve body and an actuator located on the valve body. The valve body has a fluid inlet passage, a fluid outlet passage, and a valve chamber with an upward opening. Both the fluid inlet passage and the fluid outlet passage can communicate with the valve chamber. The diaphragm valve also includes a valve seat arranged on the inner bottom surface of the valve chamber and located on the outer periphery of the fluid inlet passage, and an elastically deformable metal diaphragm covering the valve chamber. When the actuator drives the diaphragm to move towards the valve seat, the diaphragm is squeezed and sealed onto the valve seat, becoming a closed valve state, and the fluid inlet passage is closed and cannot communicate with the fluid outlet passage; when the actuator drives the diaphragm to move away from the valve seat, the diaphragm resumes its original state and separates from the valve seat, becoming an open valve state, and then the fluid inlet passage and the fluid outlet passage communicate through the valve chamber.

[0005] In the above diaphragm valve, the outer edge of the diaphragm needs to be sealed and fixed, which is crucial. The diaphragm valve also includes a retainer located above the valve chamber. The retainer is configured on the upper surface of the outer edge of the metal diaphragm and clamps the outer edge of the metal diaphragm in an airtight manner between the retainer and the inner bottom surface of the valve chamber, thereby realizing the fixation and sealing of the outer edge of the metal diaphragm. The specific analysis is as follows, as shown in the appendix of this patent Figure 1As shown, the valve chamber 30 is generally a groove-type structure. The diaphragm 40 is positioned in the groove 30, and the retainer 60 presses the outer edge of the diaphragm 40 against the outer edge of the inner bottom surface of the groove 30. However, in actual production and processing, due to the manufacturing process, there will inevitably be a chamfer 301 at the corner between the outer edge of the bottom end of the groove 30 and the inner side wall of the groove 30. The chamfer 301 will interfere with the outer edge of the diaphragm 40, resulting in the outer edge of the diaphragm 40 not being able to effectively fit the inner bottom surface of the groove 30. Therefore, there may be a certain gap between the outer edge of the diaphragm 40 and the bottom surface of the recess 30. When the retainer 60 presses the outer edge of the diaphragm 40, the outer edge of the diaphragm 40 cannot form an effective seal with the inner bottom surface of the groove 30. During the use of the diaphragm valve, the process gas in the valve chamber 30 may leak from the outer edge of the diaphragm 40. Summary of the Invention

[0006] Aiming at the deficiencies of the existing technology, the purpose of the present invention is to provide a diaphragm valve, which solves the problem that the outer edge seal of the diaphragm of the existing diaphragm valve is prone to leakage.

[0007] To achieve the above purpose, the present invention adopts the following technical solutions:

[0008] A diaphragm valve, which includes:

[0009] A valve body, including a first fluid passage and a second fluid passage. The top of the valve body has a recess, and the first fluid passage and the second fluid passage are respectively communicated with the recess;

[0010] A valve seat, arranged in the recess and surrounding the outer peripheral side of the top end of the first fluid passage;

[0011] A diaphragm, which can be elastically deformed, arranged in the recess and above the valve seat;

[0012] An actuator, connected to the top of the valve body, for driving the diaphragm to abut against or separate from the valve seat to cut off or open the diaphragm valve,

[0013] An annular support portion is arranged on the inner bottom surface of the recess and on the outer peripheral side of the valve seat. The annular support portion is spaced radially inside the inner side wall of the recess. Above the annular support portion, there is a pressing engagement member, and the pressing engagement member presses the outer edge of the diaphragm against the annular support portion to form a seal.

[0014] For the diaphragm valve of the present utility model, an annular support portion is provided in the recess of the valve body. The annular support portion protrudes from the inner bottom surface of the recess and has a certain distance from the inner side wall of the recess. The outer edge of the diaphragm is located on the annular support portion, does not contact the chamfer and is not interfered, avoiding the generation of a gap due to the interference between the outer edge of the diaphragm and the chamfer, ensuring that the diaphragm can be closely attached to the annular support portion under the pressing action of the pressing engagement member to form a seal. At this time, the side surface of the outer edge of the diaphragm can be in transitional fit with the inner side wall of the recess, and the inner side wall of the recess plays a role of radial limit, ensuring that the outer edge of the diaphragm is clamped and sealed between the pressing engagement member and the annular support portion, thereby ensuring the fixation and effective seal of the diaphragm; at the same time, compared with the original inner bottom surface of the recess, the annular support portion has a smaller force-bearing area, so it is easier to seal and fix the outer edge of the diaphragm, and the sealing effect is better.

[0015] Preferably, the recess includes a first bottom surface, a second bottom surface located obliquely above the first bottom surface, and a connecting surface connecting the outer edge of the first bottom surface and the inner edge of the second bottom surface. The annular support portion is provided on the second bottom surface. The valve seat is located radially inside the first bottom surface, and the second bottom surface forms an annular limiting section between the bottom end of the annular support portion and the top end of the connecting surface.

[0016] With such a setting, the inner bottom surface of the recess includes a first bottom surface and a second bottom surface with a height difference. The outer edge of the diaphragm is located above the second bottom surface. The space enclosed by the second bottom surface and the lower surface of the diaphragm is used for introducing fluid. The chamfer in the prior art is located at the junction of the outer edge of the second bottom surface and the inner side wall of the recess. In the present utility model, the annular support portion is provided on the second bottom surface, and the outer edge of the diaphragm is located on the annular support portion to avoid the interference of the outer edge of the diaphragm by the chamfer; at the same time, the first bottom surface is farther from the diaphragm than the second bottom surface. The valve seat is located radially inside the first bottom surface and within the coverage of the diaphragm. The actuator above the diaphragm drives the diaphragm to abut against or separate from the valve seat to cut off or open the diaphragm valve. In the closed valve state, the diaphragm abuts against the valve seat. During the process of switching to the open valve state, the actuator will remove the pressing force on the diaphragm, causing the diaphragm to elastically recover. In order to prevent the wear of the diaphragm and the valve seat and the excessive downward deformation of the diaphragm when closing the valve after long-term use, the function of the annular limiting section is to limit the downward deformation amplitude of the nearby part of the outer edge of the diaphragm located radially inside the annular support portion toward the valve seat on the premise of ensuring the normal sealing contact between the diaphragm and the valve seat, avoiding the excessive deformation of the nearby part of the diaphragm and preventing the diaphragm from elastically recovering. The annular limiting section is a distance extending inward from the inner side of the bottom end of the annular support portion to intersect with the top end of the connecting surface. When the diaphragm deforms toward the valve seat, the inner edge of the annular limiting section will abut against the nearby part of the diaphragm close to the outer edge, preventing the diaphragm from sinking excessively and ensuring that the diaphragm can still quickly recover after the actuator withdraws the acting force, and the area of the diaphragm opposite to the valve seat deforms normally, ensuring the sealing performance.

[0017] Preferably, the highest position of the top end of the valve seat is not lower than the highest position of the top end of the annular support portion in the axial direction, so that the diaphragm can abut and seal against the top end of the valve seat without significant deformation, and even after the diaphragm deforms downward, the height of the middle part of the diaphragm will not be lower than the height of the outer edge, making it easier to reset upward after the force of the actuator is withdrawn, and the diaphragm valve can respond quickly and in a timely manner. In addition, even after the top end of the valve seat wears to a certain extent after long-term use, the top end of the valve seat will not be much shorter than the annular support portion, and under the synergistic effect of the annular limiting section, the overall deformation amplitude of the diaphragm will not be excessive. On the premise of ensuring effective sealing with the valve seat, the situation where the diaphragm cannot be elastically restored can also be avoided.

[0018] Preferably, the radial width of the annular limiting section is H1, and the axial height of the annular support portion is H2, satisfying: 0.3 ≤ H2 / H1 ≤ 1.

[0019] With such a setting, controlling the axial height of the annular support portion and the radial width of the annular limiting section within the above range can not only ensure the normal deformation of the diaphragm but also prevent excessive deformation of the diaphragm; the relationship between the axial height of the annular support portion and the radial width of the annular limiting section is crucial. If H2 / H1 < 0.3, it may be that the annular limiting section is too wide, blocking too much of the diaphragm and causing the diaphragm to not deform normally, or it may be that the axial height of the annular support portion is too low, lacking deformation space between the diaphragm and the annular limiting section and resulting in abnormal diaphragm deformation, and the outer edge seal of the diaphragm is interfered with by the annular limiting section; if H2 / H1 > 1, it may be that the annular limiting section is too narrow and unable to prevent excessive downward deformation of the diaphragm, or it may be that the annular support portion is too high. On the one hand, it will increase the height of the entire valve body, and on the other hand, it will increase the axial height between the diaphragm and the valve seat, and a large driving force is required for the actuator to cause sufficient deformation of the diaphragm to seal with the valve seat, resulting in an increase in the manufacturing cost and use cost of the diaphragm valve.

[0020] Preferably, the pressing engagement member has a flat pressing surface for pressing the diaphragm, and the annular support portion has a flat pressed surface for bearing the diaphragm, and the flat pressing surface and the flat pressed surface are arranged opposite to each other.

[0021] With such a setting, the outer edge of the diaphragm is clamped and sealed between the flat pressing surface and the flat pressed surface, and is in close contact with both the flat pressing surface and the flat pressed surface respectively, thereby forming a surface sealing path with a certain distance at the outer edge of the diaphragm to ensure the sealing performance of the outer edge of the diaphragm.

[0022] Preferably, the radial width of the flat pressing surface is greater than the radial width of the flat pressed surface, and the axial projection of the flat pressing surface completely covers the axial projection of the flat pressed surface.

[0023] With such an arrangement, since the radial width of the flat pressing surface for applying pressure is large, the outer edge of the diaphragm being pressed can form good contact seals with the inner and outer ends of the flat pressure-receiving surface, ensuring effective surface sealing between the outer edge of the diaphragm and the flat pressure-receiving surface.

[0024] Preferably, the diaphragm includes an upwardly arched curved portion in the central region and a flat portion formed on the outer periphery of the curved portion, and the flat portion is hermetically clamped between the pressing engagement member and the annular support portion;

[0025] Alternatively, the diaphragm has a structure that arches upward as a whole, and its outer edge is hermetically clamped between the pressing engagement member and the annular support portion.

[0026] With such an arrangement, regardless of which of the above structures the diaphragm has, the outer edge of the diaphragm can closely fit and be clamped and sealed with the pressing engagement member and the annular support portion; the central region arches upward so as to have sufficient deformation space between the diaphragm and the valve seat, and the central region can elastically recover upward when deformed downward.

[0027] Preferably, the cross-section of the annular support portion is trapezoidal, the long bottom side of the annular support portion is connected to the second bottom surface, the short bottom side is in extrusion sealing with the diaphragm, and the angle between each waist of the annular support portion and the second bottom surface is an acute angle;

[0028] With such an arrangement, the cross-section of the annular support portion is trapezoidal, the length of the upper base of the trapezoid is less than that of the lower base, and the angle between the waist of the trapezoid and the second bottom surface is set as an acute angle, avoiding deformation of the annular support portion due to stress concentration under the strong action of the pressing engagement member, being able to reduce stress concentration, and thus ensuring the sealing performance of the outer edge of the diaphragm.

[0029] The diaphragm is made of a metal material to ensure the deformation ability and recovery ability of the diaphragm, and to have sufficient structural strength to cope with the acting force of the actuator; the valve seat is made of a fluororesin material, and deforms when abutting against the diaphragm made of the metal material, having good sealing performance.

[0030] Alternatively, a chamfer is formed at the corner of the outer edge of the inner bottom surface of the concave portion, and the annular support portion is spaced inside the bottom end of the chamfer to avoid interference contact between the chamfer and the outer edge of the diaphragm and generate a gap that affects sealing.

[0031] Alternatively, both the pressing engagement member and the annular support portion are made of a metal material, and specific different metal materials are selected to manufacture the two according to different process gases, and the materials of the two can be the same or different to improve the corrosion resistance and service life of the diaphragm valve.

[0032] Preferably, the actuator and the valve body are connected through a connecting component. The connecting component has a receiving portion for supporting the actuator. The pressing engagement member has a pressed portion for receiving the connecting component. The pressed portion presses the diaphragm, and the axial projection of the pressed portion covers the annular support portion.

[0033] With such an arrangement, the connecting component connects the actuator and the valve body into an integral body, and transmits the acting force to the pressed portion of the pressing engagement member through the receiving portion. Furthermore, the pressed portion of the pressing engagement member and the annular support portion cooperate to clamp the outer edge of the diaphragm, and the axial projection of the pressed portion covers the annular support portion, ensuring an effective surface seal between the outer edge of the diaphragm and the flat pressed surface.

[0034] Preferably, the bottom end of the pressing engagement member has a first inclined surface located radially outside the flat pressing surface and a second inclined surface located radially inside the flat pressing surface.

[0035] With such an arrangement, the function of the first inclined surface is to play a guiding role when the pressing engagement member is pressed into the recess, avoiding direct impact with the inner side wall of the recess. The function of the second inclined surface is to form an obtuse angle structure with the inner side of the flat pressing surface, avoiding the acting force on the outer edge of the diaphragm from being too concentrated at the inner side of the flat pressing surface and damaging the diaphragm. The two inclined surfaces can also cooperate together to effectively squeeze and seal the outer edge of the diaphragm.

[0036] In summary, compared with the prior art, the present utility model has at least the following beneficial effects:

[0037] In the diaphragm valve of the present utility model, an annular support portion is provided in the recess of the valve body. The annular support portion protrudes from the inner bottom surface of the recess and has a certain distance from the inner side wall of the recess. The outer edge of the diaphragm is located on the annular support portion and is not in contact with the chamfer and not interfered, avoiding the generation of a gap due to the interference between the outer edge of the diaphragm and the chamfer, ensuring that the diaphragm can be closely attached to the annular support portion under the pressing action of the pressing engagement member to form a seal. At this time, the side surface of the outer edge of the diaphragm can be in transitional fit with the inner side wall of the recess, and the inner side wall of the recess plays a role of radial limit, ensuring that the outer edge of the diaphragm is clamped and sealed between the pressing engagement member and the annular support portion, thereby ensuring the fixation and effective seal of the diaphragm. In addition, compared with the original inner bottom surface of the recess, the annular support portion has a smaller force-bearing area, making it easier to seal and fix the outer edge of the diaphragm, and the sealing effect is better. Description of the Drawings

[0038] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for the description of the specific embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0039] Figure 1 It is a schematic diagram of a diaphragm and a pressing engagement member in a groove-structured valve chamber in the prior art.

[0040] Figure 2 It is a schematic cross-sectional view of a diaphragm valve according to an embodiment of the present invention.

[0041] Figure 3 It is Figure 2 an enlarged view of part A in

[0042] Figure 4 It is Figure 2 an enlarged view of part B in

[0043] Figure 5 It is a schematic structural view of a diaphragm according to an embodiment of the present invention.

[0044] Explanation of reference numerals

[0045] 10. Valve body; 11. First fluid passage; 12. Second fluid passage;

[0046] 20. Valve seat;

[0047] 30. Recess; 31. First inner wall; 32. Second inner wall; 33. First bottom surface; 34. Second bottom surface; 35. Connecting surface; 36. Annular support portion; 361. Flat pressure-receiving surface; 37. Outer ring portion; 38. Inner ring portion; 39. Annular limiting section; 301. Chamfer;

[0048] 40. Diaphragm; 41. Bending portion; 42. Flat portion; 43. Sealing point position;

[0049] 50. Actuator;

[0050] 60. Pressing engagement member; 61. Flat pressing surface; 62. First inclined surface; 63. Second inclined surface; 64. Pressure-receiving portion;

[0051] 70. Connecting assembly; 71. Receiving portion; 72. Fixing portion. Specific embodiments

[0052] The technical solution of the present utility model will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the present utility model, rather than all of them. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present utility model without creative efforts shall fall within the protection scope of the present utility model.

[0053] In the description of the present utility model, it should be noted that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the accompanying drawings. It is only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus cannot be construed as a limitation of the present utility model. In addition, the terms "first", "second", and "third" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance.

[0054] In the description of the present utility model, it should be noted that unless otherwise clearly defined and limited, the terms "installation", "connection", and "connection" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to specific situations.

[0055] As shown in the Figure 2 accompanying drawings, the diaphragm valve of the present utility model includes a valve body 10, a valve seat 20, a diaphragm 40, and an actuator 50. The valve body 10 includes a first fluid passage 11 and a second fluid passage 12. The top end of the valve body 10 has a recess 30. The first fluid passage 11 and the second fluid passage 12 are respectively communicated with the recess 30. The valve seat 20 is annular and arranged on the valve body 10, specifically arranged in the recess 30 and surrounding the outer peripheral side of the top end of the first fluid passage 11. The diaphragm 40 can be elastically deformed, arranged in the recess 30 and above the valve seat 20, and the actuator 50 is connected to the top end of the valve body 10 and also above the diaphragm 40. Its function is to drive the diaphragm 40 to abut against or separate from the valve seat 20 to cut off or open the diaphragm valve. That is, the diaphragm 40 has an open valve state axially spaced from the valve seat 20 and a closed valve state in which it is driven by the actuator 50 to be in sealed abutment with the valve seat 20. When the diaphragm 40 is in the open valve state, the first fluid passage 11 and the second fluid passage 12 are communicated through the recess 30. When the diaphragm 40 is in the closed valve state, the first fluid passage 11 and the second fluid passage 12 are not communicated. Therefore, the sealing and fixing of the outer edge of the diaphragm 40 are crucial for the use of the diaphragm valve. Among them, the axial direction described herein is Figure 2in the vertical direction.

[0056] Specifically, the diaphragm 40 is made of a metal material, and specifically, it can be composed of a nickel-cobalt alloy or stainless steel, etc., to ensure the deformation ability and recovery ability of the diaphragm 40. Moreover, the diaphragm 40 can be a multi-layer structure, which is an integrated diaphragm 40 formed by pressing multiple nickel-cobalt alloy sheets. When pressing, while extruding, rotate the multiple nickel-cobalt alloy sheets to extrude the gas between layers, so that the layers fit well to form an integrated multi-layer structure diaphragm 40, thus having sufficient structural strength and elasticity to cope with the acting force of the actuator 50. And when the multi-layer structure diaphragm 40 is deformed downward under the acting force or restored upward when the acting force is removed, the actions of the multiple sheets of the multi-layer structure diaphragm 40 are consistent, and there is no interaction between layers to interfere with the deformation and recovery actions of the diaphragm 40. As Figure 5 shown, in other embodiments, the diaphragm 40 can be a single-layer structure, which is only made of a single nickel-cobalt alloy sheet, and the thickness of the single-layer structure diaphragm 40 can be controlled to meet sufficient structural strength and elasticity to cope with the acting force of the actuator 50. The valve seat 20 is made of a fluororesin material, and specifically, it can be made of PFA, PTFE, and PCTFE. It can deform when contacting the metal material diaphragm 40 and has good sealing performance.

[0057] As shown in the appendix Figure 1 shown, due to the limitation of the manufacturing process, there is generally a chamfer 301 between the inner side wall and the inner bottom surface of the recess 30. The chamfer 301 may be a rounded corner or an inclined angle. In order to seal and fix the outer edge of the diaphragm 40, during assembly, generally, first place the diaphragm 40 on the inner bottom surface of the recess 30. At the same time, use the inner side wall of the recess 30 to position the radial position of the diaphragm 40. Therefore, the outer edge of the diaphragm 40 will contact the chamfer 301, which will cause a gap between the outer edge of the diaphragm 40 and the inner bottom surface of the recess 30 and they cannot fit completely. When pressing the pressing engagement member 60 towards the diaphragm 40, since the outer edge of the diaphragm 40 is lifted or warped by the chamfer 301, the pressing engagement member 60 may not be pressed in place and cannot continue to be pressed down. Eventually, there is a gap between the diaphragm 40 and the inner bottom surface of the recess 30. When the diaphragm valve is working normally, both the first fluid passage 11 and the second fluid passage 12 are in communication with the recess 30. When the process gas flows from the first fluid passage 11 to the second fluid passage 12, part of the process gas may leak from the gap between the diaphragm 40 and the inner bottom surface of the recess 30.

[0058] Based on this, the diaphragm valve of this embodiment, as shown in the appendix Figure 2As shown, an annular support portion 36 is provided on the inner bottom surface of the recess 30 and on the outer peripheral side of the valve seat 20. The annular support portion 36 is spaced radially inward of the inner sidewall of the recess 30. Above the annular support portion 36, there is a pressing engagement member 60. The pressing engagement member 60 presses the outer edge of the diaphragm 40 against the annular support portion 36 to form a seal. Among them, the annular support portion 36 can be integrally formed on the valve body 10. The annular support portion 36 can be a ring-shaped convex structure protruding from the inner bottom surface of the recess 30 formed by machining the valve body 10 made of a metal material, or it can be a metal ring structure fixedly protruding on the inner bottom surface of the recess 30 by welding. The annular support portion 36 can also be a split structure of other material structures hermetically fixed on the inner bottom surface of the recess 30.

[0059] In this embodiment, at least most of the pressing engagement member 60 is located within the recess 30. To meet the installation requirements, the recess 30 has inner sidewalls with multiple different inner diameters from top to bottom. The inner sidewall corresponding to the pressing engagement member 60 and the diaphragm 40 has the smallest inner diameter, which is defined as the first inner sidewall 31. The annular support portion 36 is spaced and arranged radially inward of the first inner sidewall 31 and protrudes from the inner bottom surface of the recess 30, and has a certain distance from the chamfer 301 existing between the inner sidewall and the inner bottom surface of the recess 30. The outer edge of the diaphragm 40 is located on the annular support portion 36 and does not contact the chamfer 301, ensuring that the diaphragm 40 can be closely attached to the annular support portion 36 under the action of the pressing engagement member 60 to form a seal, that is, the outer edge of the diaphragm 40 is clamped and squeezed by the pressing engagement member 60 and the annular support portion 36 for sealing. In addition, the outer edge of the diaphragm 40 has a transitional fit with the first inner sidewall 31. At the same time, the side surface of the pressing engagement member 60 has a transitional fit with the first inner sidewall 31. The first inner sidewall 31 can play a role in radially limiting the diaphragm 40 and the pressing engagement member 60, ensuring that the outer edge of the diaphragm 40 is located between the pressing engagement member 60 and the annular support portion 36, and further ensuring the fixation and sealing of the diaphragm 40. In addition, since the annular support portion 36 protrudes from the inner bottom surface of the recess 30, compared with the original inner bottom surface of the recess 30, the stress area is smaller, so it is easier to seal and fix the outer edge of the diaphragm 40, and the sealing effect is better.

[0060] Specifically, as shown in the appendix Figure 3As shown, the recess 30 includes a first bottom surface 33, a second bottom surface 34 located obliquely above the first bottom surface 33, and a connecting surface 35 connecting the outer edge of the first bottom surface 33 and the inner edge of the second bottom surface 34. Based on the shapes of the valve body 10 and the recess 30, both the first bottom surface 33 and the second bottom surface 34 are circular rings. The first bottom surface 33 is arranged around the valve seat 20 and the top port of the first fluid passage 11, while the top port part of the second fluid passage 12 is connected to the first bottom surface 33 and part is connected to the connecting surface 35 to ensure the flow area of the second fluid passage 12. The second bottom surface 34 is located obliquely above the first bottom surface 33, the outer edge of the diaphragm 40 is located above the second bottom surface 34, and a chamfer 301 is formed at the corner of the outer edge of the inner bottom surface of the recess 30, that is, a chamfer 301 is formed at the corner between the second bottom surface 34 and the first inner side wall 31; the chamfer 301 can avoid stress concentration, and due to the existence of the annular support portion 36, the diaphragm 40 does not contact the chamfer 301, ensuring the close fit between the outer edge of the diaphragm 40 and the annular support portion 36.

[0061] As shown in the attachment Figure 4 As shown, an outer ring portion 37 and an inner ring portion 38 are arranged at intervals on the radial inner side of the first bottom surface 33. The installation groove formed by the outer ring portion 37 and the inner ring portion 38 in the recess 30, the valve seat 20 is located in the installation groove, and the outer ring portion 37 can be bent inward to fix the valve seat 20 in the installation groove. The top end of the valve seat 20 is exposed from the installation groove and cooperates with the diaphragm 40 to open or close the diaphragm valve.

[0062] Based on the relative positions of the first bottom surface 33 and the second bottom surface 34, the first bottom surface 33 is farther from the diaphragm 40 relative to the second bottom surface 34. At the same time, the valve seat 20 is located within the coverage of the diaphragm 40. The actuator 50 above the diaphragm 40 drives the diaphragm 40 to abut against or separate from the valve seat 20 to cut off or open the diaphragm valve. During this process, the diaphragm 40 will deform axially; therefore, as shown in the attachment Figure 3 As shown, the second bottom surface 34 forms an annular limiting section 39 between the bottom end of the annular support portion 36 and the top end of the connecting surface 35; the function of the annular limiting section 39 is to limit the deformation amplitude of the part near the radial inner side of the annular support portion 36 of the outer edge of the diaphragm 40 in the direction of the valve seat 20 on the premise of ensuring the normal sealing contact between the diaphragm 40 and the valve seat 20, avoiding excessive deformation of this nearby part of the diaphragm 40. The annular limiting section 39 extends inward from the inner side of the bottom end of the annular support portion 36 to intersect with the top end of the connecting surface 35. When the diaphragm 40 deforms in the direction of the valve seat 20, the inner edge of the annular limiting section 39 will abut against the area near the outer edge of the diaphragm 40 to prevent excessive sinking. After the actuator 50 withdraws the acting force, the diaphragm 40 can quickly recover; while the area of the diaphragm 40 opposite to the valve seat 20 deforms normally to ensure the sealing performance.

[0063] Specifically, as shown in the attachment Figure 3As shown, the radial width of the annular limiting section 39 is H1, and the axial height of the annular supporting section 36 is H2, satisfying: 0.3 ≤ H2 / H1 ≤ 1; it is necessary to ensure the normal deformation of the middle area of the diaphragm 40 while preventing excessive deformation of the outer edge of the diaphragm 40. As can be seen from the above, the function of the annular limiting section 39 is to prevent the outer edge of the diaphragm 40 from deforming excessively downward. If the radial width of the annular limiting section 39 is too long, it will affect the normal downward deformation of the middle area of the diaphragm 40. In addition, the normal deformation of the middle area of the diaphragm 40 is also based on the deformation space of the outer edge of the diaphragm 40. Specifically, the outer edge of the diaphragm 40 is located at the top of the annular supporting section 36, and the deformation space between the outer edge of the diaphragm 40 and the annular limiting section 39 is related to the axial height of the annular supporting section 36. Therefore, if H2 / H1 < 0.3, it may be that the annular limiting section 39 is too wide, blocking too much of the diaphragm 40, resulting in the inability of the middle area of the diaphragm 40 to deform normally. It may also be that the axial height of the annular supporting section 36 is too low, lacking sufficient deformation space between the diaphragm 40 and the annular limiting section 39, resulting in the inability of the diaphragm 40 to deform normally, and the outer edge of the diaphragm 40 is easily interfered with by the annular limiting section 39; if H2 / H1 > 1, it may be that the annular limiting section 39 is too narrow to prevent the diaphragm 40 from deforming excessively downward. It may also be that the annular supporting section 36 is too high. On the one hand, it will increase the height of the entire valve body 10. On the other hand, it will increase the axial height between the diaphragm 40 and the valve seat 20, and the actuator 50 requires a large driving force to make the diaphragm 40 deform sufficiently to seal with the valve seat 20, resulting in an increase in the manufacturing cost and use cost of the diaphragm valve.

[0064] Furthermore, the diaphragm 40 of this embodiment deforms downward after being stressed and abuts and seals against the top of the valve seat 20. The deformation degree of the diaphragm 40 depends on the axial distance between the middle part of the diaphragm 40 in the non-stressed state and the corresponding area of the valve seat 20 and the top of the valve seat 20. The highest position of the top of the valve seat 20 is not lower than the highest position of the top of the annular supporting section 36 axially, so that the diaphragm 40 can abut and seal against the top of the valve seat 20 without large deformation, and even after the diaphragm 40 deforms downward, the height of the middle part of the diaphragm 40 will not be lower than the height of the outer edge, making it easier to reset upward after the actuator 50 withdraws the force, and the diaphragm valve can respond quickly and in a timely manner.

[0065] In order to further improve the extrusion and sealing effects on the outer edge of the diaphragm 40, on the one hand, it is necessary to ensure the flatness of the outer edge of the diaphragm 40, and on the other hand, it is also required that the contact surfaces of the pressing engagement member 60 and the annular support portion 36 with the diaphragm 40 are flat. Specifically, the pressing engagement member 60 has a flat extrusion surface 61 for pressing the diaphragm 40, and the annular support portion 36 has a flat pressure-receiving surface 361 for supporting the diaphragm 40. The flat extrusion surface 61 and the flat pressure-receiving surface 361 are arranged opposite to each other; the outer edge of the diaphragm 40 is clamped and sealed between the flat extrusion surface 61 and the flat pressure-receiving surface 361, and is in close contact with both the flat extrusion surface 61 and the flat pressure-receiving surface 361, so as to form a surface sealing path with a certain distance at the outer edge of the diaphragm 40, ensuring the sealing performance of the outer edge of the diaphragm 40.

[0066] The acting force of the pressing engagement member 60 is transmitted to the upper surface of the outer edge of the diaphragm 40 through the flat extrusion surface 61, and then transmitted to the flat pressure-receiving surface 361 closely attached to the lower surface of the outer edge of the diaphragm 40, so that a surface seal is formed between the flat extrusion surface 61 and the upper surface of the outer edge of the diaphragm 40, and a surface seal is formed between the flat pressure-receiving surface 361 and the lower surface of the outer edge of the diaphragm 40.

[0067] Preferably, the radial width of the flat extrusion surface 61 is greater than the radial width of the flat pressure-receiving surface 361, and the axial projection of the flat extrusion surface 61 completely covers the axial projection of the flat pressure-receiving surface 361. Since one side of the annular support portion 36 is spaced from the inner side wall of the recess 30, and the other side is a lower annular limiting section 39, the two sides of the outer edge of the diaphragm 40 corresponding to the annular support portion 36 are in a suspended state, and the diaphragm 40 itself is made of an elastically deformable material. Therefore, when the upper flat extrusion surface 61 presses downward, the areas of the diaphragm 40 on both sides relative to the annular support portion 36 will also be forced to press downward. And because the two sides of the annular support portion 36 are suspended, the areas of the diaphragm 40 on both sides relative to the annular support portion 36 will be slightly bent, and then better sealing points 43 will be formed with the inner end and the outer end of the flat pressure-receiving surface 361, making the sealing path more complex and further improving the sealing effect of the outer edge of the diaphragm 40.

[0068] The bottom end of the pressing engagement member 60 has a first inclined surface 62 located radially outside the flat extrusion surface 61 and a second inclined surface 63 located radially inside the flat extrusion surface 61. The first inclined surface 62 is close to the first inner side wall 31 of the recess 30, and its radial width is smaller, but the inclination angle is larger, so that there is a notch at the outer edge of the bottom end of the pressing engagement member 60, which plays a guiding role when the pressing engagement member 60 is pressed into the recess 30 to avoid directly hitting the inner side wall of the recess 30; the space of the recess 30 corresponding to the second inclined surface 63 is larger, and forms an obtuse angle structure with the inner side of the flat extrusion surface 61, avoiding the acting force of the inner side of the flat extrusion surface 61 on the outer edge of the diaphragm 40 from being too concentrated and damaging the diaphragm 40.

[0069] Specifically, the diaphragm 40 can have various structures. It can be a bent portion 41 that arches upward in the central region and a flat portion 42 formed on the outer periphery of the bent portion 41, or it can be a structure that arches upward as a whole. The arched portion can be an arc structure or an arch structure. Regardless of which structure the diaphragm 40 is, the outer edge of the diaphragm 40 is flat, without independent protrusions or depressions, and due to the deformation characteristics of the diaphragm 40, it can be closely attached to and clamped and sealed with the pressing engagement member 60 and the annular support portion 36. The central region of the diaphragm 40 arches upward so that there is sufficient deformation space between the diaphragm 40 and the valve seat 20. It should be noted that the above-described structure of the diaphragm 40 refers to the shape of the diaphragm 40 when it is not under force. As shown in the appendix Figure 3 and Figure 5 shown, in this embodiment, the diaphragm 40 is a bent portion 41 that arches upward in the central region and a flat portion 42 formed on the outer periphery of the bent portion 41. The flat portion 42 is clamped and sealed between the pressing engagement member 60 and the annular support portion 36.

[0070] As shown in the appendix Figure 2 shown, in this embodiment, the cross-section of the annular support portion 36 is trapezoidal. The short bottom side of the annular support portion 36 is in extrusion sealing with the diaphragm 40, that is, the flat pressure-receiving surface 361 is located at the small end of the annular support portion 36, and the lower end of the annular support portion 36 is the large end. The long bottom side is connected to the second bottom surface 34. The angle between each waist of the annular support portion 36 and the second bottom surface 34 is an acute angle, which is also the angle between the waist and the long bottom side of the trapezoidal cross-section of the annular support portion 36. This can reduce stress concentration and prevent the annular support portion 36 from deforming under the strong action of the pressing engagement member 60, thereby ensuring the sealing performance of the outer edge of the diaphragm 40.

[0071] As shown in the appendix Figure 1As shown, the actuator 50 and the valve body 10 are connected by a connection assembly 70. The recess 30 has a second inner wall 32 which is more outward relative to the first inner wall 31 and is used for fixedly connecting with the connection assembly 70, specifically, it can be a threaded connection. The connection assembly 70 has a receiving portion 71 for supporting the actuator 50, and above the receiving portion 71, there is a fixing portion 72 connected to the actuator 50. The fixing portion 72 extends into the actuator 50 and is fixedly connected to the housing of the actuator 50 by threads; the pressing engagement member 60 has a pressure-receiving portion 64 for bearing the connection assembly 70. The receiving portion 71 is located above the pressure-receiving portion 64 and abuts against the upper surface of the pressure-receiving portion 64; specifically, since the connection assembly 70 is threadedly connected to the second inner wall 32 of the recess 30, when installing the connection assembly 70, the connection assembly 70 can be rotated to move downward along the axis, and the force received by the pressure-receiving portion 64 gradually increases. The force exerted by the pressure-receiving portion 64 on the diaphragm 40 is more controllable, avoiding excessive extrusion and damaging the diaphragm 40, which affects the sealing performance of the outer edge of the diaphragm 40. On the other hand, the axial projection of the pressure-receiving portion 64 covers the annular support portion 36, that is, the pressure-receiving portion 64 of the pressing engagement member 60 and the annular support portion 36 cooperate to clamp the outer edge of the diaphragm 40. The flat pressing surface 61 is located at the bottom end of the pressure-receiving portion 64, ensuring an effective surface seal between the outer edge of the diaphragm 40 and the flat pressure-receiving surface 361.

[0072] The above embodiments are only the preferred embodiments of the present invention and cannot be used to limit the scope of protection of the present invention. Any non-substantive changes and substitutions made by those skilled in the art based on the present invention fall within the scope of protection required by the present invention.

Claims

1. A diaphragm valve, comprising: A valve body including a first fluid passage and a second fluid passage, with a recess at the top of the valve body, and the first fluid passage and the second fluid passage are respectively in communication with the recess; A valve seat disposed within the recess and surrounding the outer peripheral side of the top end of the first fluid passage; A diaphragm which is elastically deformable, disposed within the recess and above the valve seat; An actuator connected to the top of the valve body for driving the diaphragm to abut against or separate from the valve seat to cut off or open the diaphragm valve, characterized in that An annular support portion is provided on the inner bottom surface of the recess and on the outer peripheral side of the valve seat. The annular support portion is spaced radially inward of the inner side wall of the recess. Above the annular support portion, there is a pressing engagement member which presses the outer edge of the diaphragm against the annular support portion to form a seal.

2. The diaphragm valve according to claim 1, wherein, The recess includes a first bottom surface, a second bottom surface obliquely above the first bottom surface, and a connecting surface connecting the outer edge of the first bottom surface and the inner edge of the second bottom surface. The annular support portion is provided on the second bottom surface. The valve seat is located radially inward of the first bottom surface. The second bottom surface forms an annular limiting section between the bottom end of the annular support portion and the top end of the connecting surface.

3. The diaphragm valve according to claim 1 or 2, characterized in that, The highest position of the top end of the valve seat is not lower than the highest position of the top end of the annular support portion in the axial direction.

4. The diaphragm valve according to claim 2, wherein, The radial width of the annular limiting section is H1, and the axial height of the annular support portion is H2, satisfying: 0.3 ≤ H2 / H1 ≤ 1.

5. The diaphragm valve according to claim 1, wherein, The pressing engagement member has a flat pressing surface for pressing the diaphragm, and the annular support portion has a flat pressed surface for bearing the diaphragm. The flat pressing surface and the flat pressed surface are oppositely arranged.

6. The diaphragm valve according to claim 5, characterized in that, The radial width of the flat pressing surface is greater than the radial width of the flat pressed surface, and the axial projection of the flat pressing surface completely covers the axial projection of the flat pressed surface.

7. The diaphragm valve according to claim 1, characterized in that, The diaphragm includes a curved portion that arches upward in the central region and a flat portion formed on the outer periphery of the curved portion. The flat portion is hermetically clamped between the pressing engagement member and the annular support portion; Alternatively, the diaphragm is a structure that arches upward as a whole, and its outer edge is hermetically clamped between the pressing engagement member and the annular support portion.

8. The diaphragm valve according to claim 2, wherein, The cross-section of the annular support portion is trapezoidal. The long bottom side of the annular support portion is connected to the second bottom surface, the short bottom side is in extrusion sealing with the diaphragm, and the angle between each waist of the annular support portion and the second bottom surface is an acute angle; Alternatively, the diaphragm is made of a metal material, and the valve seat is made of a fluororesin material; Alternatively, a chamfer is formed at the corner of the outer edge of the inner bottom surface of the recess, and the annular support portion is spaced inside the bottom end of the chamfer; Alternatively, both the pressing engagement member and the annular support portion are made of a metal material.

9. The diaphragm valve according to claim 1, wherein The actuator and the valve body are connected through a connecting component. The connecting component has a receiving portion for supporting the actuator. The pressing engagement member has a pressed portion for bearing the connecting component. The pressed portion presses the diaphragm, and the axial projection of the pressed portion covers the annular support portion.

10. The diaphragm valve according to claim 5, characterized in that, The bottom end of the pressing engagement member has a first inclined surface located radially outside the flat pressing surface and a second inclined surface located radially inside the flat pressing surface.

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