Diaphragm valve

Abstract

The diaphragm valve comprises a valve body, a cover body, a valve assembly and a pressure applying assembly, and the valve body is provided with a liquid inlet flow channel and a liquid outlet flow channel; the cover body is connected to one end of the valve body, a valve cavity is defined by the cover body and the valve body, the valve assembly comprises a diaphragm, the outer periphery of the diaphragm is connected between the valve body and the cover body in a pressed mode, the diaphragm divides the valve cavity into a first cavity and a second cavity, and the first cavity can be communicated with the liquid inlet flow channel and the liquid outlet flow channel; the pressure applying assembly is arranged in the second cavity and used for applying acting force towards the first cavity to the diaphragm. A first limiting structure is arranged between the cover body and the diaphragm and is used for limiting the outer periphery of the diaphragm to move inwards or deform in the radial direction of the diaphragm; a second limiting structure is arranged between the valve body and the diaphragm and used for limiting the outer periphery of the diaphragm to move inwards or deform in the radial direction of the diaphragm. The upper side and the lower side of the diaphragm are both provided with the limiting structures for limiting the diaphragm outer periphery sealing part to move inwards or deform in the radial direction of the diaphragm, and the situation that the diaphragm outer periphery sealing part loses efficacy in sealing is avoided.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of valves, in particular to a diaphragm valve. BACKGROUND

[0002] The diaphragm valve is a valve body, which is internally provided with a diaphragm structure, so as to divide the valve body into a driving cavity and a valve cavity, thereby effectively avoiding that components in the driving cavity pollute fluid or fluid in the valve cavity enters the driving cavity to corrode the driving structure.

[0003] In the diaphragm valve, fluid pressure in the valve cavity will act on the diaphragm, so that the diaphragm has an inward pulling force on the outer peripheral sealing portion; especially in diaphragm valves such as pressure reducing valves, constant pressure valves and constant flow valves, when the pressure or flow in the valve body changes, the diaphragm in the valve body will constantly move due to the change of flow, in this case, the diaphragm will make the outer peripheral sealing portion more easily be pulled inward and deformed, thereby causing the outer peripheral sealing portion to be more prone to sealing failure. CONTENT OF THE UTILITY MODEL

[0004] Therefore, it is necessary to provide a diaphragm valve capable of reducing failure of the outer peripheral sealing portion of the diaphragm.

[0005] The application provides a diaphragm valve, which comprises:

[0006] A valve body is provided with an inlet flow channel and an outlet flow channel;

[0007] A cover body is connected to one end of the valve body, and the cover body and the valve body enclose a valve cavity,

[0008] A valve assembly comprises a diaphragm whose outer periphery is crimped between the valve body and the cover body, the diaphragm divides the valve cavity into a first cavity and a second cavity, and the first cavity is arranged in communication with the inlet flow channel and the outlet flow channel;

[0009] A pressure applying assembly is arranged in the second cavity to apply an action force to the diaphragm towards the first cavity;

[0010] A first limiting structure is arranged between the cover body and the diaphragm, and the first limiting structure is used to limit the diaphragm outer periphery to move or deform radially inward along the diaphragm;

[0011] A second limiting structure is arranged between the valve body and the diaphragm, and the second limiting structure is used to limit the diaphragm outer periphery to move or deform radially inward along the diaphragm.

[0012] The first limiting structure and the second limiting structure are arranged on the upper and lower sides of the diaphragm, that is, the limiting structure is arranged on the upper and lower sides of the diaphragm to limit the movement or deformation of the outer peripheral sealing portion of the diaphragm in the radial direction of the diaphragm, thereby avoiding the movement or deformation of the upper side or the lower side of the outer peripheral sealing portion, and avoiding the thinning of the thickness of the outer peripheral sealing portion of the diaphragm due to the movement or deformation in the radial direction, which affects the sealing effect, and even the separation of the outer peripheral sealing portion of the diaphragm from the clamping of the valve body and the cover.

[0013] In one of the embodiments, the first limiting structure comprises a first annular protrusion arranged at the bottom end of the cover, and the first annular protrusion is arranged to bite into the diaphragm.

[0014] In the embodiment, the first annular protrusion is arranged to bite into the diaphragm, and the arrangement of the protrusion biting into the diaphragm limits the movement of the outer peripheral portion of the diaphragm in the radial direction of the diaphragm, especially the movement of the upper side of the diaphragm in the radial direction, thereby ensuring the sealing effect of the diaphragm, and the first limiting structure is simple in structure and easy to process.

[0015] In one of the embodiments, the first limiting structure further comprises a first annular groove arranged on the diaphragm, and the first annular protrusion is arranged to bite into the first annular groove.

[0016] In this way, the first annular protrusion can bite deeper into the diaphragm by cooperating with the first annular groove, and the diaphragm will not be abnormally deformed due to the excessive depth of the first annular protrusion biting into the diaphragm, and the sealing effect of the diaphragm will not be affected, thereby having a better limiting effect on the outer peripheral portion of the diaphragm.

[0017] In one of the embodiments, the first annular protrusion is provided with a first taper surface facing the central area of the valve body, and a second taper surface facing the outer peripheral area of the valve body, and the second taper surface is steeper than the first taper surface.

[0018] And / or, when the diaphragm is provided with a first annular groove cooperating with the first annular protrusion, the first annular groove has a third taper surface facing the outer peripheral area of the cover, and a fourth taper surface facing the central area of the cover, and the fourth taper surface is steeper than the third taper surface.

[0019] When the diaphragm moves radially inward, the radial inward movement is mainly limited by the abutment between the second taper surface and the diaphragm and the abutment between the fourth taper surface and the first annular protrusion; when the diaphragm moves radially outward, the radial inward movement is mainly limited by the abutment between the first taper surface and the diaphragm and the abutment between the third taper surface and the first annular protrusion. The fact that the first taper surface is steeper than the second taper surface and the third taper surface is steeper than the fourth taper surface makes it more difficult for the diaphragm to move radially inward than radially outward, thereby effectively preventing the diaphragm from moving radially inward. Moreover, even if the diaphragm moves slightly inward or deforms slightly due to fluid pressure, the diaphragm will move outward more easily after the fluid pressure decreases, so as to reset the diaphragm and prevent the diaphragm from continuously moving inward during use, which may result in a large cumulative movement or deformation of the diaphragm after a long time of use, and may cause the diaphragm to fail to seal.

[0020] In one embodiment, the depth of the first annular groove is less than the height of the first annular protrusion.

[0021] In this way, when the cover is crimped to the outer periphery of the diaphragm, the part of the first annular protrusion that is higher than the first annular groove can be tightly bitten into the diaphragm, and the first annular protrusion can be tightly attached to the diaphragm, so as to ensure the biting effect of the first annular protrusion and the first annular groove, thereby ensuring the limiting effect on the diaphragm and further ensuring the sealing of the outer periphery of the diaphragm.

[0022] In one embodiment, the first annular protrusion and the first annular groove are both provided in a plurality, and the plurality of first annular protrusions are engaged in the plurality of first annular grooves one by one.

[0023] In this way, the plurality of first annular protrusions and the plurality of first annular grooves cooperate to better limit the deformation or movement of the outer periphery of the diaphragm radially inward.

[0024] In one embodiment, the second limiting structure comprises a second annular protrusion arranged on the diaphragm and a second annular groove arranged on the valve body, and the second annular protrusion is engaged in the second annular groove.

[0025] In this way, by arranging the second annular protrusion engaged in the second annular groove, the diaphragm can better resist the radial inward force between the bottom end of the diaphragm and the valve body, so as to prevent the bottom end of the diaphragm from moving or deforming radially inward when the diaphragm is affected by fluid, thereby ensuring the sealing effect of the diaphragm.

[0026] In one embodiment, the first limiting structure is located directly above the second limiting structure.

[0027] In this way, the force can be concentrated between the first limiting structure and the second limiting structure, so that the first annular protrusion and the diaphragm and the second annular protrusion and the second annular groove can have greater abutting force, so as to better limit the diaphragm and avoid the diaphragm deforming radially inward to affect the sealing effect of the diaphragm.

[0028] In one of the embodiments, the valve assembly comprises a valve core, the diaphragm is an annular diaphragm and the inner periphery is sealingly mounted on the valve core, and a connecting portion is arranged between the inner periphery sealing portion and the outer periphery sealing portion of the diaphragm; wherein a pressing plate is arranged inside the second cavity, the connecting portion comprises a fitting portion and a deformation portion located outside the fitting portion, the top end of the fitting portion is fitted with the bottom end of the pressing plate and is limited to deform upward by the pressing plate, and the deformation portion is located between the pressing plate and the outer periphery.

[0029] In this way, when the fluid presses the diaphragm, the diaphragm will deform upward, and by arranging the pressing plate at the top end of the diaphragm, part of the diaphragm will abut against the pressing plate, so that the part of the diaphragm cannot deform upward by the pressing plate, that is, the fitting portion; and the remaining part of the connecting portion that is not fitted with the pressing plate will deform upward, at this time the deformation portion will deform, but there is a fitting portion between the deformation portion and the inner periphery sealing portion, so that the deformation of the deformation portion has relatively small effect on the inner periphery sealing portion, thereby ensuring that the deformation of the deformation portion does not easily cause the inner periphery sealing portion to fail.

[0030] In one of the embodiments, a third annular groove is arranged on the valve core, a third annular protrusion is arranged at the bottom end of the diaphragm, the third annular protrusion is sealingly arranged with the inner wall of the third annular groove, and the pressing plate is pressed above the third annular protrusion and the third annular groove.

[0031] In this way, by arranging the third annular protrusion and the third annular groove in sealing cooperation and pressing the pressing plate above the third annular protrusion and the third annular groove, the third annular protrusion is not easy to come out of the third annular groove, thereby ensuring that the inner periphery of the diaphragm forms a good seal.

[0032] In one of the embodiments, the valve core is located at the bottom end of the diaphragm, a screw penetrating the diaphragm and the pressing plate is threadedly connected to the valve core, and the diaphragm is pressed tightly on the valve core by the pressing plate through the screw; wherein a pressure distribution ring is sleeved on the screw, the pressure distribution ring is located between the pressing plate and the head of the screw, and is used to transmit the pressure between the pressing plate and the head of the screw.

[0033] In this way, by arranging the screw to connect the diaphragm and the pressing plate, the inner periphery of the diaphragm is tightly pressed. Moreover, the pressure of the head of the screw can be first dispersed by the pressure distribution ring, then dispersed by the pressing plate, and finally the pressure can be well dispersed on the fitting portion of the inner periphery of the diaphragm, thereby forming a good pressure sealing effect. BRIEF DESCRIPTION OF DRAWINGS

[0034] To more clearly illustrate the technical solutions in the embodiments of this application or the conventional technology, the drawings used in the description of the embodiments or the conventional technology will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0035] Figure 1 This is a cross-sectional structural schematic diagram of a diaphragm valve according to an embodiment of this application;

[0036] Figure 2 for Figure 1 A magnified view of a section at point A in the middle;

[0037] Figure 3 for Figure 1 A magnified view of a section at point B in the middle;

[0038] Figure 4 This is a cross-sectional view of a diaphragm according to an embodiment of this application;

[0039] Figure 5 This is a perspective view of a diaphragm according to an embodiment of this application;

[0040] Figure 6 for Figure 2 Schematic diagram of the structure when the diaphragm separates from the cover.

[0041] Reference numerals: 10, valve body; 101, inlet channel; 102, outlet channel; 103, first chamber; 11, valve body outer shell; 12, valve body inner shell; 121, flow passage; 122, valve seat; 123, connecting passage; 20, cover; 201, second chamber; 21, outer cover; 22, inner cover; 30, valve assembly; 31, diaphragm; 311, connecting part; 3111, fitting part; 3112, deformable part; 313. 32. Third annular protrusion; 33. Valve core; 34. Third annular groove; 35. Pressure plate; 36. Screw; 47. Pressure dividing ring; 48. Pressure application assembly; 59. First limiting structure; 50. First annular protrusion; 51. First conical surface; 52. Second conical surface; 53. First annular groove; 54. Third conical surface; 55. Fourth conical surface; 66. Second limiting structure; 67. Second annular protrusion; 68. Second annular groove. Detailed Implementation

[0042] To make the above objectives, features and advantages of the present application more clear and comprehensible, specific embodiments of the present application will be described below in detail with reference to the accompanying drawings. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present application. However, the present application can be practiced in a number of different ways beyond the specific embodiments described and should not be limited to these specific embodiments. It is to be understood that other embodiments can be utilized and structural or logical changes can be made without departing from the scope of the present application.

[0043] It is to be noted that when a component is referred to as being "on" or "disposed on" another component, it can be directly on the other component or intervening components can also be present. When a component is referred to as being "connected" to another component, it can be directly connected to the other component or intervening components can also be present. The terms "vertical", "horizontal", "upper", "lower", "left", "right", and similar terms as used in the description of the specification are for the purpose of illustration only and do not indicate an exclusive embodiment.

[0044] In addition, the terms "first", "second", and the like, are used merely to describe items that differ from one another, without necessarily implying a relative importance or a quantity. Thus, a feature defined with "first" or "second" can implicitly or explicitly include at least one of the features. In the description of the specification, the meaning of "a plurality" is at least two, such as two, three, etc., unless otherwise specifically defined.

[0045] In the present application, unless otherwise explicitly specified and limited, "on", "under", "above", and "over" of a first feature to a second feature can mean that the first feature is in direct contact with the second feature, or the first feature is in indirect contact with the second feature through an intermediate medium. Moreover, "above", "over", and "on" of a first feature to a second feature can mean that the first feature is directly above or obliquely above the second feature, or only means that the first feature is horizontally higher than the second feature. "Below", "under", and "underneath" of a first feature to a second feature can mean that the first feature is directly below or obliquely below the second feature, or only means that the first feature is horizontally lower than the second feature.

[0046] Unless otherwise defined, all technical and scientific terms used in the specification of the present application have the same meaning as commonly understood by one of ordinary skill in the art to which the present application belongs. The terms used in the specification of the present application are only for the purpose of describing specific embodiments and are not intended to limit the present application. The term "and / or" used in the specification of the present application includes any and all combinations of one or more of the associated listed items.

[0047] Please refer to Figure 1This application provides a diaphragm valve, including: a valve body 10, a cover 20, a valve assembly 30, and a pressure application assembly 40. The valve body 10 has an inlet channel 101 and an outlet channel 102; the cover 20 is connected to one end of the valve body 10, and the cover 20 and the valve body 10 enclose a valve cavity; the valve assembly 30 includes a diaphragm 31 whose outer periphery is pressed between the valve body 10 and the cover 20, the diaphragm 31 dividing the valve cavity into a first cavity 103 and a second cavity 201, the first cavity 103 being communicatively connected to the inlet channel 101 and the outlet channel 102; the pressure application assembly 40 is disposed in the second cavity 201 and is used to apply a force to the diaphragm 31 toward the first cavity 103. Thus, the fluid enters the valve body 10 from the inlet channel 101, passes through the valve assembly 30, and is finally discharged from the outlet channel 102. When the fluid pressure or flow rate changes, causing a pressure difference to form between the first chamber 103 and the second chamber 201, the fluid pressure acts on the diaphragm 31, making the sealing part of the outer periphery of the diaphragm 31 easily pulled inward and deformed.

[0048] like Figure 1 As shown, a first limiting structure 50 is provided between the cover 20 and the diaphragm 31. The first limiting structure 50 is used to restrict the outer periphery of the diaphragm 31 from moving or deforming radially inward along the diaphragm 31. A second limiting structure 60 is provided between the valve body 10 and the diaphragm 31. The second limiting structure 60 is used to restrict the outer periphery of the diaphragm 31 from moving or deforming radially inward along the diaphragm 31. Thus, when there is a pressure difference between the first cavity 103 and the second cavity 201, the diaphragm 31 deforms and exerts an inward pulling force on the outer periphery sealing part, making the outer periphery sealing part prone to inward deformation or even movement, thereby affecting the sealing effect of the outer periphery sealing part. This application avoids the sealing failure of the outer periphery sealing part of the diaphragm 31 by setting the first limiting structure 50 and the second limiting structure 60, that is, by setting limiting structures on both the upper and lower sides of the diaphragm 31 to restrict the outer periphery sealing part of the diaphragm 31 from moving or deforming radially inward along the diaphragm 31.

[0049] In an embodiment, the first limiting structure 50 comprises a first annular protrusion 51 arranged at the bottom end of the cover 20, and the first annular protrusion 51 is bitten into the diaphragm 31. It is worth mentioning that "bitten into" refers to the close fit or engagement between two components, so that they can be fixed together or work together. In this embodiment, by arranging the first annular protrusion 51 to be bitten into the diaphragm 31, on the one hand, through the part of the first annular protrusion 51 bitten into the diaphragm, the angle of the contact surface between the first annular protrusion 51 and the diaphragm 31 can be changed, that is, the radial resistance of the diaphragm 31 can be overcome by the radial abutment between the first annular protrusion 51 and the diaphragm 31, so that the radial resistance can be better overcome; on the other hand, it can be considered that the structure of the first annular protrusion 51 bitten into the diaphragm 31 makes the contact surface rougher, thereby increasing the friction coefficient between the two, so that the two can better overcome the radial resistance, thereby limiting the outer peripheral portion of the diaphragm 31, so that the outer peripheral portion of the diaphragm 31 cannot move radially inward along the diaphragm 31, thereby ensuring the sealing effect of the diaphragm 31, and the first limiting structure 50 has a simple structure and is easy to process.

[0050] Further, please refer to Figure 2 , Figure 4 and Figure 5 , the first limiting structure 50 further comprises a first annular groove 52 arranged on the diaphragm 31, and the first annular protrusion 51 is engaged in the first annular groove 52. In this way, through the cooperation of the first annular protrusion 51 and the first annular groove 52, the first annular protrusion 51 can be bitten deeper into the diaphragm 31, thereby having a better limiting effect on the outer peripheral portion of the diaphragm 31, and at the same time, it can also avoid that the diaphragm 31 is abnormally deformed due to the excessive depth of the first annular protrusion 51 bitten into the diaphragm 31, thereby affecting the sealing effect of the diaphragm 31.

[0051] Please refer to Figure 2 and Figure 6 , in an embodiment, the first annular protrusion 51 is provided with a first taper surface 511 facing the central area of the valve body 10, and a second taper surface 512 facing away from the central area of the cover 20, and the second taper surface 512 is steeper than the first taper surface 511. It is worth mentioning that a "surface" exists between a "solid" and a "virtual", that is, the two sides of a "surface" are a "solid" and a "virtual" respectively, wherein the direction of the virtual is the direction of the "surface", that is, the "surface" faces the virtual. "Steeper" means a smaller angle with the vertical line. And the directions of the first taper surface 511 and the second taper surface 512 are Figure 6The direction indicated by the arrow is shown in the middle. In this embodiment, the second conical surface 512 is steeper than the first conical surface 511, so that the included angle formed by the first conical surface 511 and the second conical surface 512 can better prevent the outer peripheral part of the diaphragm 31 from deforming or moving inward. This allows the first annular protrusion 51 to bite into the diaphragm 31 and better restrict the diaphragm 31 from deforming or moving inward.

[0052] More specifically, when the diaphragm 31 moves radially inward, the second conical surface 512 mainly abuts against the diaphragm 31 radially to restrict the diaphragm 31 from moving radially inward. The steeper the second conical surface 512, that is, the closer it is to a vertical surface, the greater the radial component of the abutment force between the second conical surface 512 and the diaphragm 31, so as to better restrict the inward movement of the diaphragm 31.

[0053] Furthermore, even if excessive fluid pressure causes the outer periphery sealing portion of the diaphragm 31 to move radially inward by a small distance, when the fluid pressure decreases, the restoring force of the diaphragm 31 will cause the outer periphery sealing portion to tend to move radially outward. At this time, the outward deformation of the diaphragm 31 is limited by the contact between the first conical surface 511 and the diaphragm 31. This is because the first conical surface 511 is closer to horizontal than the second conical surface 512; that is, when the first conical surface 511 contacts the diaphragm 31, the radial component of the contact force is smaller, meaning the diaphragm 31 can deform radially outward relatively easily. In other words, this structure ensures that even when the fluid pressure is high and causes the diaphragm 31 to deform radially inward, after the fluid pressure decreases, the diaphragm 31 can relatively easily return to its radially outward position under the action of its restoring force, thus preventing the diaphragm 31 from continuously deforming inward and causing a gradual decrease in its sealing effect.

[0054] like Figure 2 as well as Figure 6 As shown, in an embodiment where the diaphragm 31 has a first annular groove 52 that mates with the first annular protrusion 51, the first annular groove 52 further has a third conical surface 521 facing the outer peripheral region of the cover 20 and a fourth conical surface 522 facing the central region of the cover 20, the fourth conical surface 522 being steeper than the third conical surface 521. The aforementioned third conical surface 521 and fourth conical surface 522 are oriented in the following directions: Figure 6The direction indicated by the arrow corresponding to the middle conical surface. Similar to the principle of the first conical surface 511 and the second conical surface 512 mentioned above, the fourth conical surface 522 makes it more difficult for the diaphragm 31 to move radially inward, while the third conical surface 521 makes it easier for the diaphragm 31 to move radially outward relative to radial inward movement. This effectively prevents the diaphragm 31 from moving radially inward. Even if it moves radially inward and deforms by a small distance, it will easily return to its original position under the action of its own restoring force after the fluid pressure decreases. This avoids the diaphragm 31 from constantly moving radially inward, which could lead to a large cumulative deformation or displacement of the diaphragm 31 over a long period of use, resulting in sealing failure of the diaphragm 31.

[0055] In one embodiment, the first annular protrusion 51 has a first conical surface 511 and a second conical surface 512, and the first annular groove 52 has a third conical surface 521 and a fourth conical surface 522. When the first annular protrusion 51 engages with the first annular groove 52, the first conical surface 511 engages with the third conical surface 521, and the second conical surface 512 engages with the fourth conical surface 522. Furthermore, the first conical surface 511 is steeper than the third conical surface 521, and the second conical surface 512 is steeper than the fourth conical surface 522, thereby making the first annular protrusion 51 and the first annular groove 52 fit more tightly and better restricting the inward deformation or movement of the diaphragm 31.

[0056] Furthermore, the depth of the first annular groove 52 is less than the height of the first annular protrusion 51. Thus, when the cover 20 is pressed against the outer periphery of the diaphragm 31, the portion of the first annular protrusion 51 that protrudes above the first annular groove 52 can tightly grip into the diaphragm 31 and fully fit the diaphragm 31, thereby further improving the gripping effect of the first annular protrusion 51 and the first annular groove 52 and preventing sealing failure at the outer periphery of the diaphragm 31.

[0057] Please see Figures 2 to 5 Furthermore, multiple first annular protrusions 51 and multiple first annular grooves 52 are provided, with each of the multiple first annular protrusions 51 corresponding to and engaging with the multiple first annular grooves 52. In this way, the cooperation of the multiple first annular protrusions 51 and the multiple first annular grooves 52 provides a better limiting effect on the radially inward deformation or movement of the outer periphery of the diaphragm 31. In one embodiment, three first annular protrusions 51 and three first annular grooves 52 are provided, which has a good limiting effect on the movement or deformation of the outer periphery of the diaphragm 31. Of course, the number of first annular protrusions 51 and first annular grooves 52 can also be other than that, and this application does not limit this.

[0058] Please see Figure 1 and Figure 3, the second limiting structure 60 comprises a second annular protrusion 61 arranged on the diaphragm 31 and a second annular groove 62 arranged on the valve body 10, and the second annular protrusion 61 is clamped into the second annular groove 62. In this way, by arranging the second annular protrusion 61 clamped into the second annular groove 62, the contact area between the outer peripheral portion of the diaphragm 31 and the valve body 10 can be increased, so that the outer peripheral portion of the diaphragm 31 is not easy to move or deform along the radial direction of the diaphragm 31, thereby ensuring the sealing effect of the diaphragm 31, and the second limiting structure 60 has a simple structure and is easy to process. Of course, Figures 1-3 It is only a schematic diagram, and after the diaphragm 31 is installed and subjected to pressure, it will be deformed to achieve that the second annular protrusion 61 completely or mostly fills the second annular groove 62, so as to ensure that the second annular protrusion 61 and the second annular groove 62 can be fully sealed.

[0059] Further, the height of the second annular protrusion 61 is greater than the depth of the second annular groove 62, so that in the process of crimping the diaphragm 31, the second annular protrusion 61 is compressed and will fully abut against the inner wall of the second annular groove 62, thereby ensuring the sealing effect between the second annular protrusion 61 and the second annular groove 62.

[0060] In the embodiment, the cross section of the second annular protrusion 61 is semicircular, and the cross section of the second annular groove 62 is square. By pressing the outer periphery of the diaphragm 31 with the cover body 20, the second annular protrusion 61 can be firmly clamped in the second annular groove 62, thereby preventing the outer periphery of the diaphragm 31 from moving or deforming inward from the lower side of the diaphragm 31. Of course, the cross-sectional shape of the second annular protrusion 61 is not limited to this semicircle, and can also be square or trapezoidal or other shapes. Similarly, the cross-sectional shape of the second annular groove 62 is not limited to square, and can also be trapezoidal or other shapes.

[0061] Further, the first limiting structure 50 is located directly above the second limiting structure 60. This arrangement makes the stress on the upper and lower sides of the diaphragm 31 concentrated at one place, so that the pressure is concentrated at the positions of the first annular protrusion 51 and the second annular protrusion 61, thereby achieving that the outer peripheral portion of the diaphragm 31 is less likely to deform or move inward along the radial direction.

[0062] Please refer to Figure 1 and Figure 4 , Figure 5, the valve assembly 30 comprises a valve core 32, the diaphragm 31 is an annular diaphragm and is sealingly mounted on the valve core 32 at the inner periphery, and a connecting portion 311 is arranged between the inner periphery sealing portion and the outer periphery sealing portion of the diaphragm 31. It can be understood that the "inner periphery sealing portion" of the diaphragm 31 refers to the inner periphery portion of the diaphragm 31 sealingly connected with the valve core 32, and the "outer periphery sealing portion" of the diaphragm 31 refers to the outer periphery portion being crimped between the valve body 10 and the cover body 20. The second cavity 201 is internally provided with a pressing plate 33, the connecting portion 311 comprises a fitting portion 3111 and a deformation portion 3112 located outside the fitting portion 3111, the top end of the fitting portion 3111 is fitted with the bottom end of the pressing plate 33 and is limited to be deformed upward by the pressing plate 33, and the deformation portion 3112 is located between the pressing plate 33 and the outer periphery. In this way, by arranging the pressing plate 33, the inner side portion of the diaphragm 31 (i.e. the fitting portion 3111 located below the pressing plate 33) is not easy to deform, and the main deformation portion 3112 is concentrated on the outer side portion of the diaphragm 31, i.e. on the deformation portion 3112 located outside the pressing plate 33, so that the deformation of the deformation portion 3112 to the inner periphery sealing portion is avoided, and the sealing failure of the inner periphery sealing portion is avoided.

[0063] Further, the valve core 32 is provided with a third annular groove 323, and the diaphragm 31 is provided with a third annular protrusion 313, the third annular protrusion 313 is sealingly arranged with the inner wall of the third annular groove 323, so that the third annular protrusion 313 forms the inner periphery sealing portion of the diaphragm 31. The pressing plate 33 is crimped above the third annular protrusion 313 and the third annular groove 323. In this way, by arranging the third annular protrusion 313 and the third annular groove 323 in sealing cooperation, and crimping the pressing plate 33 above the third annular protrusion 313 and the third annular groove 323, the third annular protrusion 313 is not easy to come out of the third annular groove 323, so as to ensure that the inner periphery portion of the diaphragm 31 forms a good seal.

[0064] Further, the height of the third annular protrusion 313 is greater than the depth of the third annular groove 323, so that in the process of crimping the diaphragm 31, the third annular protrusion 313 is compressed and will be in full abutment with the inner wall of the third annular groove 323, so as to ensure the sealing effect between the third annular protrusion 313 and the third annular groove 323.

[0065] Further, the valve core 32 is located at the bottom end of the diaphragm 31, and a screw 34 is threadedly connected to the valve core 32, the screw 34 compresses the diaphragm 31 on the valve core 32 through the pressing plate 33. In this way, the inner peripheral portion of the diaphragm 31 is tightly compressed. Further, the screw 34 is sleeved with a pressure distribution ring 35, the pressure distribution ring 35 is located between the pressing plate 33 and the head of the screw 34, and is used to transmit the pressure between the two. In this way, the pressure of the head of the screw 34 can be first distributed through the pressure distribution ring 35, and then distributed through the pressing plate 33, and finally the pressure can be well distributed to the abutting portion 3111 of the inner peripheral portion of the diaphragm 31, thereby forming a good compression sealing effect. Of course, in other embodiments, the diaphragm 31 can also be integrally formed or connected with the valve core by welding and the like.

[0066] In the embodiment, the pressure applying assembly 40 is connected to the head of the screw 34, and the pressure applying assembly 40 is an elastic assembly, which will be compressed when the upward pressure is greater than the elastic force of the elastic assembly, and when the upward pressure is less than the elastic force of the elastic assembly, the elastic assembly will push the valve core 32 and the inner peripheral portion of the diaphragm 31 to move downward. Of course, in other embodiments, the pressure applying assembly 40 can also be a gas pressure control structure arranged at the top end of the diaphragm 31, and the downward force on the diaphragm 31 is realized by controlling the gas pressure.

[0067] Please refer to Figure 1 In an embodiment, the cover 20 includes an outer cover 21 and an inner cover 22 arranged in the outer cover 21, the outer cover 21 is threadedly connected with the valve body 10 and compresses the inner cover 22, so that the inner cover 22 compresses the outer peripheral portion of the diaphragm 31 on the valve body 10. Correspondingly, the first limiting structure 50 is arranged between the inner cover 22 and the diaphragm 31. In the embodiment, the outer cover 21 and the inner cover 22 are arranged in a split structure, but are not limited thereto, in other embodiments, the outer cover 21 and the inner cover 22 can also be an integral structure, as long as the cover 20 formed by the outer cover 21 and the inner cover 22 can cooperate with the valve body 10 to realize the function of the diaphragm valve; similarly, in other embodiments, the cover 20 and the valve body 10 can also be connected by bolts and the like.

[0068] As Figure 1As shown, the valve body 10 comprises a valve body outer shell 11 and a valve body inner shell 12, the valve body inner shell 12 is installed in the valve body outer shell 11, the cover body 20 is used to press the diaphragm 31 on the valve body inner shell 12, and the second limiting structure 60 is arranged between the valve body inner shell 12 and the diaphragm 31, that is, the second annular groove 62 is arranged on the valve body inner shell 12. In the embodiment, the valve body outer shell 11 and the valve body inner shell 12 are arranged in a split structure, which facilitates the installation of the valve assembly 30 in the valve body 10. However, it is not limited thereto, and in other embodiments, the valve body outer shell 11 and the valve body inner shell 12 can also be in an integrated structure, as long as the valve body 10 formed by the valve body outer shell 11 and the valve body inner shell 12 can cooperate with the cover body 20 to realize the function of the diaphragm valve.

[0069] Please refer to Figure 1 The valve body 10 of the diaphragm valve shown in the embodiment comprises a valve body outer shell 11 and a valve body inner shell 12 arranged in a split structure, the inlet flow channel 101 and the outlet flow channel 102 are arranged in the valve body outer shell 11, and the valve body inner shell 12 is provided with a flow passage 121. The flow passage 121 communicates the inlet flow channel 101 and the outlet flow channel 102, and the valve seat 122 is arranged between the flow passage 121 and the outlet flow channel 102. The valve core 32 is used to cooperate with the valve seat 122 to control the opening degree of the valve seat 122, so as to realize the control of the pressure in the outlet flow channel 102. The upper end of the valve body inner shell 12 and the diaphragm 31 surround the first cavity 103, and the valve body inner shell 12 is further provided with a communication passage 123, which communicates the first cavity 103 and the outlet flow channel 102.

[0070] The working principle of the diaphragm valve is as follows: the fluid pressure in the inlet flow channel 101 is P1, and the fluid pressure will be lost when passing through the valve seat 122, so that the pressure drop between the outlet flow channel 102 and P1 exists, and the pressure drop at the valve seat 122 is P4, wherein P4=P1-P2. Due to the arrangement of the communication channel 123, the pressure P3 of the fluid in the first cavity 103 is related to P2 and changes with P2. The effective pressure receiving area of the diaphragm 31 by the fluid is S, the pressure F1 of the diaphragm 31 by the fluid is P3*S, and the pressure F2 of the top end by the pressing assembly 40. When P2 decreases, P3 will also decrease at this time, P3*S<F2 at this time, so the pressing assembly 40 will push the inner peripheral portion of the diaphragm 31 and the valve core 32 downward to increase the opening degree of the valve seat 122, so that the pressure drop at this position is reduced, thereby increasing the pressure P2. Conversely, the same is true. Finally, the fluid in the outlet flow channel 102 is always maintained around P2, and the fluid pressure in the outlet flow channel 102 will not fluctuate sharply due to the fluctuation of the pipeline pressure. That is, the pressure of the inlet flow channel 101 can be reduced to the required pressure P2. The pressure P2 can be adjusted by changing the installation position or compression degree of the pressing assembly 40 to adjust the pressure of the pressing assembly 40, thereby changing the size of the pressure P2. Of course, the foregoing only illustrates the function of the valve body, and the influence factors such as the pressure of the fluid on the valve core 32 and the change amount of the spring force are ignored.

[0071] The structure inside the valve body 10 and the cover 20 is not limited to Figure 1 As long as there is a pressure difference between the two sides of the diaphragm 31, the diaphragm 31 will deform and pull the outer peripheral portion of the diaphragm 31 inward, so as long as the outer peripheral portion of the diaphragm 31 is crimped between the valve body 10 and the cover 20, the first limiting structure 50 and the second limiting structure 60 can be arranged to limit the outer peripheral portion of the diaphragm 31, thereby reducing the failure of the outer peripheral portion of the diaphragm 31.

[0072] The diaphragm valve shown in the drawings of the present application is a pressure reducing valve, but is not limited thereto. The diaphragm valve can also be a constant pressure valve, a constant flow valve, a back pressure valve, or even other types of valves with a diaphragm 31 mounting structure, such as an open and close valve.

[0073] The technical features of the above-described embodiments can be combined in any manner. In order to make the description concise, all possible combinations of the technical features in the above-described embodiments are not described, but as long as the combinations of the technical features do not exist, they should be considered as the scope of the present application.

[0074] The above-described embodiments are merely illustrative of several embodiments of the present application, which are described in more detail and in a specific manner, but should not be construed as limiting the scope of the patent application. It should be noted that for those skilled in the art, several modifications and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the patent protection scope of the present application should be subject to the appended claims.

Claims

1. A diaphragm valve, comprising: a valve body provided with an inlet flow channel and an outlet flow channel; a cover body connected to one end of the valve body, the cover body and the valve body enclosing a valve cavity, a valve assembly comprising a diaphragm with an outer periphery crimped between the valve body and the cover body, the diaphragm separating the valve cavity into a first cavity and a second cavity, the first cavity being capable of being in communication with the inlet flow channel and the outlet flow channel; a pressing assembly provided in the second cavity for applying a force to the diaphragm towards the first cavity; characterized in that a first limiting structure is provided between the cover body and the diaphragm, the first limiting structure being used to limit the movement or deformation of the outer periphery of the diaphragm radially inward along the diaphragm; a second limiting structure is provided between the valve body and the diaphragm, the second limiting structure being used to limit the movement or deformation of the outer periphery of the diaphragm radially inward along the diaphragm.

2. The diaphragm valve of claim 1, wherein The first limiting structure comprises a first annular protrusion provided at the bottom end of the cover body, the first annular protrusion being engaged into the diaphragm.

3. The diaphragm valve of claim 2, wherein, The first limiting structure further comprises a first annular groove provided on the diaphragm, the first annular protrusion being engaged into the first annular groove.

4. The diaphragm valve of claim 2, wherein The first annular protrusion is provided with a first taper surface towards the central area of the valve body and a second taper surface towards the outer periphery area of the valve body, the second taper surface being steeper than the first taper surface; and / or, when the diaphragm is provided with a first annular groove cooperating with the first annular protrusion, the first annular groove has a third taper surface towards the outer periphery area of the cover body and a fourth taper surface towards the central area of the cover body, the fourth taper surface being steeper than the third taper surface.

5. The diaphragm valve of claim 4, wherein, The depth of the first annular groove is less than the height of the first annular protrusion.

6. The diaphragm valve of claim 4, wherein, The first annular protrusion and the first annular groove are both provided in plurality, the plurality of first annular protrusions being engaged into the plurality of first annular grooves one by one.

7. The diaphragm valve of claim 1, wherein The second limiting structure comprises a second annular protrusion provided on the diaphragm and a second annular groove provided on the valve body, the second annular protrusion being engaged into the second annular groove.

8. The diaphragm valve of claim 1, wherein, The first limiting structure is located directly above the second limiting structure.

9. The diaphragm valve of claim 1, wherein, The valve assembly comprises a valve core, the diaphragm is an annular diaphragm and the inner periphery of the diaphragm is sealingly mounted on the valve core, a connecting portion being provided between the inner periphery sealing portion and the outer periphery sealing portion of the diaphragm; wherein a pressing plate is provided inside the second cavity, the connecting portion comprises a fitting portion and a deformation portion located outside the fitting portion, the top end of the fitting portion is fitted with the bottom end of the pressing plate and is limited to be deformed upward by the pressing plate, and the deformation portion is located between the pressing plate and the outer periphery.

10. The diaphragm valve of claim 9, wherein, A third annular groove is provided on the valve core, a third annular protrusion is provided at the bottom end of the diaphragm, the third annular protrusion is sealingly fitted with the inner wall of the third annular groove, and the pressing plate is crimped above the third annular protrusion and the third annular groove.

11. The diaphragm valve of claim 9, wherein, The valve core is located at the bottom end of the diaphragm, a screw is threadedly connected to the valve core, the screw penetrates through the diaphragm and the pressing plate, and the screw presses the diaphragm tightly on the valve core through the pressing plate; wherein the screw is sleeved with a pressure distribution ring, the pressure distribution ring is located between the pressing plate and the head portion of the screw, and is used to transmit the pressure between the pressing plate and the head portion of the screw.

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