Diaphragm valve

Abstract

The utility model discloses a diaphragm valve, which comprises a valve body, a driving component, a diaphragm and a diaphragm, the valve assembly is matched with the valve shaft to change the state of fluid in the valve body; the valve assembly comprises a first diaphragm and a second diaphragm which are arranged in a stacked mode. The first diaphragm is provided with a valve core, a first outer edge part and a deformation part; the second diaphragm is provided with a second outer edge part, a supporting part and an inner edge part, and the supporting part can abut against the deformation part so as to support the deformation part; the inner edge portion is located between the valve body and the valve shaft, and a partition gap can be formed between the deformation portion and the supporting portion. The separation gap is formed between the deformation part of the first diaphragm and the supporting part of the second diaphragm, when the valve shaft drives the valve element to move in the axial direction, abrasion between the deformation part and the supporting part can be reduced through the separation gap, and damage to the first diaphragm and the second diaphragm caused by repeated friction between the first diaphragm and the second diaphragm in the process is avoided; and the service lives of the first diaphragm and the second diaphragm are prolonged.

Description

Technical Field

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

[0002] A diaphragm valve is a special valve that can open and close a fluid passage or adjust the liquid delivery volume of a fluid passage in an open state by moving or deforming a diaphragm. Since it separates the fluid passage from the non-fluid area through the diaphragm, it has a high cleanliness and is widely used in pipelines for transporting high-purity media such as ultrapure water.

[0003] At present, some diaphragm valves are provided with a double-diaphragm structure to ensure that the diaphragm is not easily damaged due to the pressure of the fluid. However, the diaphragm valve with double diaphragms has the following disadvantages: when the valve shaft drives the diaphragm to deform to open and close the diaphragm valve, there will be relative friction between the two diaphragms in the double diaphragm, resulting in large wear and tear, which makes the diaphragm easily damaged and shortens the service life of the diaphragm. Summary of the Utility Model

[0004] The technical problem to be solved by the utility model is to provide a diaphragm valve to solve the problem that double diaphragms are easily worn against each other.

[0005] To solve the above technical problem, the utility model adopts the following technical scheme: a diaphragm valve, comprising: a valve body, which has an inflow channel and an outflow channel for fluid to pass through inside; a driving assembly, installed in the valve body and including a valve shaft that can move axially; a valve assembly, cooperating with the valve shaft to change the state of the fluid in the valve body; the valve assembly includes a first diaphragm and a second diaphragm arranged in a stacked manner. The first diaphragm divides the inside of the valve body into a fluid side and a non-fluid side, and the second diaphragm is located on the non-fluid side of the first diaphragm; the first diaphragm has a valve core connected to the valve shaft, a first outer edge portion fixed on the valve body, and a deformation portion located between the first outer edge portion and the valve core; the second diaphragm has a second outer edge portion fixed on the valve body, a support portion facing the deformation portion, and an inner edge portion located inside the support portion. The support portion can abut against the deformation portion to support the deformation portion; the inner edge portion is located between the valve core and the valve shaft and is driven to move axially by the valve core and / or the valve shaft. Among them, a separation gap can be formed between the deformation portion and the support portion. The technical scheme has the following technical effects:

[0006] By setting the second diaphragm, the utility model can support the first diaphragm that is subjected to the fluid pressure on the fluid side, avoiding excessive deformation and damage of the deformation portion of the first diaphragm caused by too large fluid side pressure. The first diaphragm and the second diaphragm are arranged in a stacked manner, enabling good bending deformation between the first diaphragm and the second diaphragm during the process of opening and closing the valve, so as to ensure that the first diaphragm and the second diaphragm can move along with the drive of the valve shaft.

[0007] Meanwhile, since a separation gap is provided between the deformed portion of the first diaphragm and the supporting portion of the second diaphragm, during the process of the valve shaft driving the first diaphragm and the second diaphragm to move and deform, the separation gap can reduce the contact between the deformed portion of the first diaphragm and the supporting portion of the second diaphragm. Therefore, when the valve shaft drives the valve core to move axially to open and close the diaphragm valve, the separation gap can reduce the wear between the deformed portion and the supporting portion, avoiding the damage to both caused by repeated friction between the first diaphragm and the second diaphragm during this process, thereby extending the service life of the first diaphragm and the second diaphragm.

[0008] In the above-mentioned diaphragm valve, the deformed portion and the supporting portion are non-conformal, and the separation gap is formed between the deformed portion and the supporting portion. When the deformed portion and the supporting portion are not subjected to external forces, their shapes are different. When the first diaphragm and the second diaphragm are assembled together, the deformed portion and the supporting portion cannot fit due to their different shapes, and thus a separation gap can be naturally formed between the deformed portion and the supporting portion, reducing the production, processing, and assembly difficulties.

[0009] In the above-mentioned diaphragm valve, the first diaphragm is an elastic member. When the first diaphragm deforms axially, it will have a tendency to rebound, and through the rebound, the separation gap is formed between the deformed portion and the supporting portion, or the separation gap is increased. When the pressure on the fluid side is too high, the first diaphragm can be fully or largely in contact with the second diaphragm to achieve the support of the second diaphragm for the first diaphragm, avoiding the damage to the first diaphragm due to excessive pressure. When the pressure on the fluid side decreases, the first diaphragm can rebound under the action of its own elastic force. When the first diaphragm and the second diaphragm are not fully in contact, the separation gap is increased; or when the first diaphragm and the second diaphragm are fully in contact, they are separated, so that a separation gap is generated again between the first diaphragm and the second diaphragm. Then, when the valve shaft drives the valve core of the first diaphragm to move subsequently, the separation gap can reduce the contact between the deformed portion of the first diaphragm and the supporting portion of the second diaphragm again, thereby reducing the wear between the deformed portion and the supporting portion, extending the service life of the first diaphragm and the second diaphragm, and avoiding the first diaphragm and the second diaphragm remaining in the contact state after being in contact under the pressure of the fluid.

[0010] In the above-mentioned diaphragm valve, the deformed portion has an annular protrusion, and the separation gap is formed between the annular protrusion and the supporting portion or between both sides of the annular protrusion and the supporting portion. The setting of the annular protrusion enables a separation gap to be naturally formed between the deformed portion and the supporting portion when the first diaphragm and the second diaphragm are assembled together, reducing the production, processing, and assembly difficulties.

[0011] In the above-mentioned diaphragm valve, the annular protrusion is arranged to protrude toward the fluid side. The annular protrusion can increase the area of the deformation part, so that the area of the deformation part is larger than the area of the support part. When the deformation part is subjected to fluid pressure, it has enough area to deform to abut against the support part, so that the support part can support the deformation part to avoid damage to the deformation part due to pressure. Because the area of the deformation part is large and protrudes toward the fluid side, when the fluid applies pressure to the deformation part, part of the pressure needs to first overcome the elastic force of the bent deformation part to restore the deformation, so that the deformation part can resist greater pressure.

[0012] In the above-mentioned diaphragm valve, the second diaphragm is an annular diaphragm structure sleeved on the outside of the valve shaft, the valve shaft includes a limiter, an active area is formed between the limiter and the valve core, the inner edge can move axially in the active area and form a channel with the valve core for gas to enter and exit the separation gap. Gas can flow between the non-fluid side and the separation gap through the channel, and the channel can make the first diaphragm and the second diaphragm not a relatively sealed crimped structure. Even if the first diaphragm is squeezed by a large fluid pressure to expel the air in the separation gap, when the fluid pressure decreases, the first diaphragm is deformed and reset under the action of elastic force, and the separation gap between the first diaphragm and the second diaphragm can also re-inhale air through the channel to avoid the formation of a negative pressure space inside the separation gap, causing the deformation part to be completely fitted or a large area of the support part, and causing the deformation part and the support part to be worn more seriously when the valve shaft drives the diaphragm to move.

[0013] In the above-mentioned diaphragm valve, the limiter is provided with an annular abutment portion surrounding the central axis of the valve shaft, and the annular abutment portion can abut against the second diaphragm to limit the radial movement of the second diaphragm. When the first diaphragm and the second diaphragm are not subjected to the pressure of the fluid, the second diaphragm does not contact the annular abutment portion or only contacts without a large pressing force. When the first diaphragm and the second diaphragm are subjected to the pressure of the fluid, the second diaphragm will abut against the annular abutment portion, and the annular abutment portion presses the second diaphragm to avoid radial movement and deformation of the inner edge of the second diaphragm.

[0014] In the above-mentioned diaphragm valve, the valve core is provided with a limiting cylinder located inside the second diaphragm, and the inner diameter of the second diaphragm is larger than the outer diameter of the limiting cylinder. When the inner edge moves axially in the active area, there is a gap between the second diaphragm and the limiting cylinder to prevent the wear of the two, thereby preventing the wear between the limiting cylinder and the second diaphragm from generating particles and entering between the deformation part and the support part, thereby preventing the particles from causing aggravated wear of the deformation part and the support part, thereby extending the service life of the two.

[0015] In the above-mentioned diaphragm valve, the hardness of the support part is not lower than that of the deformation part, and the thickness of the support part is not less than that of the deformation part. By setting the hardness of the support part to be the same as or greater than that of the deformation part, the support part can withstand a greater pressure, and thus the support effect of the support part on the deformation part is better, avoiding the situation where the support part is easily deformed due to its low hardness and resulting in the inability to support the deformation part. By setting the thickness of the support part to be the same as or greater than that of the deformation part, the support effect of the support part on the deformation part is further enhanced, avoiding excessive deformation and damage of the deformation part due to the applied force.

[0016] In the above-mentioned diaphragm valve, the valve body includes a base and a cover located on the upper side of the base. The first outer edge part and the second outer edge part are mutually attached and are crimped between the base and the cover. Among them, the thickness of the first outer edge part is greater than that of the deformation part, and a clearance part is formed between the inner side edge of the first outer edge part and the bottom end of the deformation part. When the deformation part deforms, the clearance part can avoid the edges on the base, so as to prevent the sharp edges from interfering with the deformation part and causing damage to the first diaphragm, and prolong the service life of the first diaphragm.

[0017] The features and advantages of the present utility model will be disclosed in detail in the following specific embodiments and drawings. Brief Description of the Drawings

[0018] The present utility model will be further described below in conjunction with the drawings and specific embodiments:

[0019] Figure 1 is a cross-sectional view of the diaphragm valve;

[0020] Figure 2 is Figure 1 an enlarged view of part A of

[0021] Figure 3 is a partial exploded view of the valve assembly;

[0022] Figure 4 is a three-dimensional view of the first diaphragm.

[0023] Reference Signs:

[0024] 100, valve body; 110, cover; 120, base; 121, inflow channel; 122, outflow channel; 123, valve seat; 130, fluid side; 140, non-fluid side;

[0025] 200, valve shaft; 210, limiting member; 211, annular abutting portion; 220, active area;

[0026] 300, valve assembly;

[0027] 310. First diaphragm; 311. Valve core; 3111. Limit cylinder body; 312. First outer edge part; 313. Deformation part; 3131. Annular protrusion; 314. Avoidance part;

[0028] 320. Second diaphragm; 321. Inner edge part; 322. Second outer edge part; 323. Support part; 324. Channel;

[0029] 330. Separation gap. Detailed implementation mode

[0030] A diaphragm valve proposed by the present utility model includes: a valve body, which has an inflow channel and an outflow channel for fluid to pass through inside; a driving assembly, installed in the valve body and including a valve shaft that can move axially; a valve assembly, cooperating with the valve shaft to change the state of the fluid in the valve body; the valve assembly includes a first diaphragm and a second diaphragm arranged in layers, the first diaphragm divides the inside of the valve body into a fluid side and a non-fluid side, and the second diaphragm is located on the non-fluid side of the first diaphragm; the first diaphragm has a valve core connected to the valve shaft, a first outer edge part fixed on the valve body, and a deformation part located between the first outer edge part and the valve core; the second diaphragm has a second outer edge part fixed on the valve body, a support part facing the deformation part, and an inner edge part located inside the support part, and the support part can abut against the deformation part to support the deformation part; the inner edge part is located between the valve core and the valve shaft and is driven to move axially by the valve core and / or the valve shaft, wherein a separation gap can be formed between the deformation part and the support part. By setting the second diaphragm, the present utility model can support the first diaphragm impacted by the fluid on the fluid side, avoiding excessive deformation and damage of the deformation part of the first diaphragm caused by too large pressure on the fluid side; and by arranging the first diaphragm and the second diaphragm in layers, it can be realized that the first diaphragm and the second diaphragm are more likely to deform, avoiding the overall thickness of the first diaphragm and the second diaphragm being too large due to the setting of the second diaphragm, and causing the structure to be difficult to bend and deform, or even generating large stress after bending and deformation, resulting in easy damage of the diaphragm.

[0031] At the same time, because a separation gap is provided between the deformation part of the first diaphragm and the support part of the second diaphragm, during the reciprocating movement of the diaphragm, the contact between the deformation part of the first diaphragm and the support part of the second diaphragm can be reduced through the separation gap, so as to reduce the wear between the two, avoid repeated friction between the first diaphragm and the second diaphragm during this process and cause damage to the two, thereby prolonging the service life of the first diaphragm and the second diaphragm.

[0032] The technical solutions of the embodiments of the present utility model will be explained and described below with reference to the accompanying drawings of the embodiments of the present utility model. However, the following embodiments are only the preferred embodiments of the present utility model and not all of them. Based on the embodiments in the embodiments, other embodiments obtained by those skilled in the art without creative efforts all fall within the protection scope of the present utility model.

[0033] In the description of the present utility model, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "clockwise", "counterclockwise", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the 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 should not be construed as a limitation to the present utility model.

[0034] In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present utility model, unless otherwise specified, the meaning of "a plurality" is two or more, unless otherwise clearly defined.

[0035] In the present utility model, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected to", "fixed", etc. should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral connection; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may 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 circumstances.

[0036] In the present utility model, unless otherwise clearly specified and limited, the first feature being "above" or "below" the second feature may include the direct contact between the first and second features, or may include the situation where the first and second features are not in direct contact but in contact through other features therebetween. Moreover, the first feature being "above", "over" and "on" the second feature includes that the first feature is directly above and obliquely above the second feature, or merely indicates that the horizontal height of the first feature is higher than that of the second feature. The first feature being "under", "beneath" and "under" the second feature includes that the first feature is directly below and obliquely below the second feature, or merely indicates that the horizontal height of the first feature is lower than that of the second feature.

[0037] A diaphragm valve, such asFigures 1 to 4 As shown, it includes a valve body 100, a drive assembly and a valve assembly 300. The interior of the valve body 100 is provided with an inlet channel 121, an outlet channel 122 and a valve seat 123 for fluid to pass through. The valve seat 123 is formed between the inlet channel 121 and the outflow channel 122 to connect the inlet channel 21 and the outflow channel 122. The drive assembly is installed in the valve body 100. The drive assembly includes a valve shaft 200 slidably connected in the valve body 100, and the valve shaft 200 can move axially. The valve assembly 300 is arranged in the valve body 100 and cooperates with the valve shaft 200. The valve assembly 300 is used to change the state of the fluid in the valve body 100 under the drive of the valve shaft 200. The valve assembly 300 includes a first diaphragm 310 and a second diaphragm 320, which are stacked between the valve seat 123 and the valve shaft 200. The first diaphragm 310 separates the interior of the valve body 100 into a fluid side 130 and a non-fluid side 140 that are not connected to each other. The fluid side 130 is located between the first diaphragm 310 and the valve seat 123 to allow fluid to pass through, and the non-fluid side 140 is located on the side of the first diaphragm 310 that is away from the valve seat 123. The second diaphragm 320 can support the first diaphragm 310, so that when the first diaphragm 310 is subjected to fluid pressure, the first diaphragm 310 is not easily damaged by the fluid pressure through the support of the second diaphragm 320; at the same time, the first diaphragm 310 and the second diaphragm 320 are stacked, so that even if the overall thickness of the first diaphragm 310 and the second diaphragm 320 is relatively thick, the thickness of a single first diaphragm 310 or second diaphragm 320 is relatively small and relatively soft, thereby ensuring that the inner side of the first diaphragm 310 and the second diaphragm 320 can undergo axial movement, that is, ensuring that the diaphragm as a whole can be easily deformed, and that no large stress is generated that causes easy damage to the diaphragm.

[0038] like Figure 3 As shown, the first diaphragm 310 has an integrally arranged valve core 311, a first outer edge portion 312 and a deformation portion 313, the valve core 311 is connected to the end of the valve shaft 200, the deformation portion 313 surrounds the outer peripheral side of the valve core 311, and the first outer edge portion 312 surrounds the outer peripheral side of the deformation portion 313, so that the deformation portion 313 is located between the first outer edge portion 312 and the valve core 311, and the first outer edge portion 312 is fixed to the valve body 100; the second diaphragm 320 has an integrally arranged inner edge portion 321, a second outer edge portion 322 and a support portion 323, the support portion 323 is annular and is arranged opposite to the deformation portion 313 in the axial direction of the valve assembly 300 (as shown in FIG. Figure 1 and 2As shown, the dashed lines indicate the positions on the inner and outer sides of the deformation part 313, and the part of the second diaphragm 320 located between the dashed lines is the support part 323). The inner edge part 321 is provided on the inner peripheral side of the support part 323. The inner edge part 321 is located between the valve core 311 and the valve shaft 200. The second outer edge part 322 is provided on the outer peripheral side of the support part 323 and fixed to the valve body 100, as Figure 1 and Figure 2 shown, a separation gap 330 is formed between the deformation part 313 and the support part 323.

[0039] The valve shaft 200 can drive the first diaphragm 310 and the second diaphragm 320 to deform by reciprocating axially to block or open the valve seat 123. When the valve seat 123 is opened, the liquid can flow from the inflow channel 121 into the outflow channel 122. When the valve seat 123 is closed, the liquid in the inflow channel 121 cannot enter the outflow channel 122. When the valve shaft 200 drives the valve core 311 to move axially along the valve shaft 200 to open and close the valve seat 123, it simultaneously drives the inner edge part 321 to move axially along the valve shaft 200 and causes the deformation part 313 to deform. The separation gap 330 can separate the deformation part 313 from the support part 323 to reduce the friction between the deformation part 313 and the support part 323 during the deformation process. Of course, it can be understood that when the valve shaft 200 reciprocates axially, the inner edge part 321 in this embodiment can be connected to the valve core 311 to move together with the valve core 311, or connected to the valve shaft 200 to move together with the valve shaft 200, or simultaneously connected to the valve core 311 and the valve shaft 200 to move together with both; it should also be noted that it is not required to fixedly connect the inner edge part 321 to the valve core 311 or the valve shaft 200 here. For example, the inner edge part 321 moves between the valve core 311 and the valve shaft 200 and abuts against the valve core 311 or the valve shaft 200 to realize the axial movement of the inner edge part 321 being pushed.

[0040] By providing the second diaphragm 320 in the present utility model, it can support the first diaphragm 310 that is subjected to the fluid pressure on the fluid side 130, avoiding excessive deformation and damage of the deformation part 313 of the first diaphragm 310 caused by too high pressure on the fluid side 130. At the same time, because there is a separation gap 330 between the deformation part 313 of the first diaphragm 310 and the support part 323 of the second diaphragm 320, during the reciprocating movement and deformation of the first diaphragm 310 and the second diaphragm 320, the contact between the deformation part 313 of the first diaphragm 310 and the support part 323 of the second diaphragm 320 can be reduced through the separation gap 330. Thus, the wear between the deformation part 313 and the support part 323 can be reduced through the separation gap 330, avoiding repeated friction between the first diaphragm 310 and the second diaphragm 320 and causing damage to both, and prolonging the service life of the first diaphragm 310 and the second diaphragm 320.

[0041] Preferably, in the present embodiment, the deformation portion 313 and the support portion 323 are non-conformal, that is, when the deformation portion 313 and the support portion 323 are not subjected to external force, the deformation portion 313 and the support portion 323 have different shapes. When the first diaphragm 310 and the second diaphragm 320 are assembled together, the deformation portion 313 and the support portion 323 cannot fit together due to their different shapes, and thus a separation gap 330 can be naturally formed between the deformation portion 313 and the support portion 323, thereby reducing the difficulty of production, processing and assembly.

[0042] The first diaphragm 310 in this embodiment is an elastic member. When the first diaphragm 310 is deformed in the axial direction under the action of external force, the first diaphragm 310 has a tendency to rebound under the action of elastic force. When the pressure on the fluid side 130 is too high, the first diaphragm 310 can be completely fitted with the second diaphragm 320 or fitted with a large area to achieve the support of the second diaphragm 320 for the first diaphragm 310, which can prevent the first diaphragm 310 from being damaged due to excessive pressure; when the pressure on the fluid side 130 decreases, the first diaphragm 310 can rebound under the action of its own elastic force to increase the separation gap 330 when the first diaphragm 310 and the second diaphragm 320 are not completely fitted, or to separate the first diaphragm 310 and the second diaphragm 320 when they are completely fitted, so that the first diaphragm 310 and the second diaphragm 320 are completely fitted. A separation gap 330 is formed again between the membranes 320, so that when the subsequent valve shaft 200 drives the valve core 311 of the first diaphragm 310 to move, the separation gap 330 can again reduce the contact between the deformation part 313 of the first diaphragm 310 and the support part 323 of the second diaphragm 320, thereby reducing the wear between the deformation part 313 and the support part 323, extending the service life of the first diaphragm 310 and the second diaphragm 320, and avoiding the first diaphragm 310 and the second diaphragm 320 always remaining in contact and the friction between the first diaphragm 310 and the second diaphragm 320 is large when the valve shaft 200 moves.

[0043] When the first diaphragm 310 is axially deformed, the shapes of the first diaphragm 310 and the second diaphragm 320 are changed, and the air or gas in the separation gap 330 will flow between the first diaphragm 310 and the second diaphragm 320 due to the squeezing force between the first diaphragm 310 and the second diaphragm 320, thereby achieving lubrication between the first diaphragm 310 and the second diaphragm 320 through the flow of the air or gas, thereby further reducing the friction between the two, and during this lubrication process, compared with lubrication by lubricating oil or other methods, it will not cause pollution to the diaphragm.

[0044] When not under pressure, refer to Figure 3In this embodiment, the deformation portion 313 is bent and bulged as a whole toward the fluid side 130, so that the deformation portion 313 forms an annular protrusion 3131 toward the fluid side 130, and the deformation portion 313 is recessed toward the side of the support portion 323 away from the support portion 323, so as to form a separation gap 330 between the annular protrusion 3131 and the support portion 323. The structure of the deformation part 313 bending and bulging toward the fluid side 130 can increase the area of the deformation part 313 under the same radial width, so that the area of the deformation part 313 is larger than the area of the support part 323. When the deformation part 313 is subjected to fluid pressure, it has enough area to deform to abut against the support part 323, so that the support part 323 can support the deformation part 313 to avoid the deformation part 313 being damaged by pressure. Because the area of the deformation part 313 is large and protrudes toward the fluid side 130, when the fluid applies pressure to the deformation part 313, part of the pressure needs to first overcome the elastic force of the bent deformation part 313 to restore the deformation, so that the deformation part 313 can resist greater pressure. Of course, it can be understood that in this embodiment, an annular protrusion protruding toward the second diaphragm 320 can also be set on the deformation part, and the annular protrusion abuts against the support part of the second diaphragm 320 to form a separation gap 330 on both sides of the annular protrusion.

[0045] The separation gap 330 may be sealed with gas between the deformation portion 313 of the first diaphragm 310 and the support portion 323 of the second diaphragm 320, or may not be sealed between the first diaphragm 310 and the second diaphragm 320, and preferably the interior of the separation gap 330 is not a sealed chamber.

[0046] Specifically: refer to Figure 1 as well as Figure 2 The second diaphragm 320 is an annular diaphragm structure sleeved on the outside of the valve shaft 200. The valve shaft 200 includes a limiting member 210. The limiting member 210 is located on the side of the second diaphragm 320 away from the first diaphragm 310. Figure 2 As shown, an active area 220 is formed between the limit member 210 and the valve core 311, and the thickness of the inner edge portion 321 of the second diaphragm 320 is smaller than the width of the active area 220 (i.e., the distance between the limit member 210 and the valve core 311), so that the inner edge portion 321 can move axially in the active area 220, and the inner edge portion 321 can fit with or separate from the valve core 311 by moving axially in the active area 220.

[0047] When the inner edge portion 321 is separated from the valve core 311, a channel 324 that connects the non-fluid side 140 and the separation gap 330 can be formed between the inner edge portion 321 and the valve core 311. Gas can flow between the non-fluid side 140 and the separation gap 330 through the channel 324. The channel 324 can make the structure between the first diaphragm 310 and the second diaphragm 320 not a relatively sealed and crimped structure. That is, when the first diaphragm 310 is subjected to a relatively large fluid pressure, it squeezes the separation gap 330 to discharge the air in the separation gap 330. When the fluid pressure decreases, the first diaphragm 310 can deform and reset under the action of elastic force. The first diaphragm 310 and the second diaphragm 320 can re-inhale air through the channel 324 to form the separation gap 330 or make the separation gap 330 increase. This can prevent the first diaphragm 310 and the second diaphragm 320 from always remaining in a tightly fitting state, or from always being in a state of large-area contact, and prevent a sealed negative pressure space from being formed inside the separation gap 330. It should be noted that the channel 324 does not always exist between the inner edge portion 321 and the valve core 311. Instead, when the air in the separation gap 330 is squeezed out or a negative pressure is generated in the separation gap 330 due to the recovery deformation of the first diaphragm 310, the channel 324 can be formed between the inner edge portion 321 and the valve core 311.

[0048] Preferably in this embodiment, a limiting cylinder body 3111 is provided at the central position of the valve core 311. The limiting cylinder body 3111 passes through the center of the second diaphragm 320 and abuts against the bottom of the limiting member 210, so that the limiting cylinder body 3111 is located inside the second diaphragm 320. The inner diameter of the second diaphragm 320 is larger than the outer diameter of the limiting cylinder body 3111. When the inner edge portion 321 moves axially in the movable area 220, there is a gap between the second diaphragm 320 and the limiting cylinder body 3111 to avoid wear between the two, which can prevent excessive wear between the limiting cylinder body 3111 and the second diaphragm 320 and extend the service life of both.

[0049] As Figure 2 shown, in this embodiment, an annular abutting portion 211 is provided on the side of the limiting member 210 facing the second diaphragm 320. The annular abutting portion 211 is arranged around the central axis of the valve shaft 200. When the first diaphragm 310 and the second diaphragm 320 are not subjected to fluid pressure, the second diaphragm 320 does not contact the annular abutting portion 211. When the first diaphragm 310 and the second diaphragm 320 are subjected to fluid pressure, the second diaphragm 320 will abut against the annular abutting portion 211. By crimping the second diaphragm 320 through the annular abutting portion 211, the radial movement deformation of the inner edge portion 321 of the second diaphragm 320 can be avoided.

[0050] In this embodiment, the hardness of the support portion 323 is not lower than that of the deformation portion 313, that is, the hardness of the support portion 323 is the same as or greater than that of the deformation portion 313, so that the support portion 323 can bear a greater pressure, and thus the support effect of the support portion 323 on the deformation portion 313 is better. The thickness of the support portion 323 is not less than that of the deformation portion 313, that is, the thickness of the support portion 323 is the same as or greater than that of the deformation portion 313, so as to further enhance the support effect of the support portion 323 on the deformation portion 313 and prevent the deformation portion 313 from being damaged due to excessive deformation under force.

[0051] The valve body 100 in this embodiment includes a base 120 and a cover 110. The cover 110 is connected to the upper side of the base 120 and locked with the base 120. The first outer edge portion 312 at the edge of the first diaphragm 310 and the second outer edge portion 322 at the edge of the second diaphragm 320 are mutually attached in the vertical direction. The base 120 and the cover 110 simultaneously clamp the first outer edge portion 312 and the second outer edge portion 322, so that the first diaphragm 310 and the second diaphragm 320 are simultaneously fixed on the valve body 100 to achieve the installation and limitation of the first diaphragm 310 and the second diaphragm 320. Preferably, as Figure 3 and Figure 4 shown, the first outer edge portion 312 protrudes downward from the bottom so that its thickness is greater than that of the deformation portion 313. The thickness of the deformation portion 313 is less than that of the first outer edge portion 312, which is convenient for the deformation portion 313 to deform. At the same time, an avoidance portion 314 can be formed between the inner side edge of the first outer edge portion 312 and the bottom end of the deformation portion 313. There is an edge on the inner peripheral side of the table surface of the base 120 for clamping the first diaphragm 310 and the second diaphragm 320. When the deformation portion 313 deforms, the avoidance portion 314 can avoid the edge on the base 120 to prevent the sharp edge from interfering with the deformation portion 313 and causing damage to the first diaphragm 310, thereby prolonging the service life of the first diaphragm 310.

[0052] In addition, it should be noted that in the valve body including the above valve assembly 300, it is not limited to the aforementioned on-off valve structure, and it can also be a flow regulating valve, a pressure regulating valve, a back suction valve and other valve bodies.

[0053] Of course, in other embodiments, it can be arranged in the opposite direction to the Figure 1 fluid flow direction, that is, Figure 1 the left side in the

[0054] The above are only the preferred embodiments of the present utility model, and the protection scope of the present utility model is not limited to the above embodiments. All technical solutions falling within the concept of the present utility model belong to the protection scope of the present utility model. It should be noted that for those of ordinary skill in the art, several improvements and refinements made without departing from the principle of the present utility model should also be regarded as within the protection scope of the present utility model.

Claims

1. A diaphragm valve, comprising: A valve body having an inflow passage and an outflow passage inside for fluid to pass through; A drive assembly installed in the valve body and including a valve shaft that can move axially; A valve assembly cooperating with the valve shaft to change the state of the fluid in the valve body; Characterized in that The valve assembly includes a first diaphragm and a second diaphragm arranged in layers. The first diaphragm divides the interior of the valve body into a fluid side and a non-fluid side, and the second diaphragm is located on the non-fluid side of the first diaphragm; The first diaphragm has a valve core connected to the valve shaft, a first outer edge portion fixed to the valve body, and a deformation portion located between the first outer edge portion and the valve core; The second diaphragm has a second outer edge portion fixed to the valve body, a support portion facing the deformation portion, and an inner edge portion located inside the support portion. The support portion can abut against the deformation portion to support the deformation portion; The inner edge portion is located between the valve core and the valve shaft and is driven to move axially by the valve core and / or the valve shaft. Wherein, a separation gap can be formed between the deformation portion and the support portion.

2. The diaphragm valve according to claim 1, characterized in that, The deformation portion and the support portion are non-conformingly arranged, and the separation gap is formed between the deformation portion and the support portion.

3. A diaphragm valve according to claim 1, characterized in that, The first diaphragm is an elastic member. When the first diaphragm is axially deformed, the first diaphragm will have a tendency to rebound, and the separation gap will be formed between the deformation portion and the support portion or the separation gap will be increased through the rebound.

4. A diaphragm valve according to any one of claims 1 to 3, characterized in that, The deformation portion has a ring-shaped protrusion, and the separation gap is formed between the ring-shaped protrusion and the support portion or between both sides of the ring-shaped protrusion and the support portion.

5. A diaphragm valve according to claim 4, wherein, The ring-shaped protrusion protrudes towards the fluid side.

6. A diaphragm valve according to claim 1, characterized in that, The second diaphragm is an annular diaphragm structure sleeved outside the valve shaft. The valve shaft includes a limiting member, and an activity area is formed between the limiting member and the valve core. The inner edge portion can move axially in the activity area and form a channel for gas to enter and exit the separation gap with the valve core.

7. A diaphragm valve according to claim 6, characterized in that, The limiting member is provided with an annular abutting portion surrounding the central axis of the valve shaft, and the annular abutting portion can abut against the second diaphragm to limit the radial movement of the second diaphragm.

8. A diaphragm valve according to claim 6, characterized in that, The valve core is provided with a limiting cylinder body located inside the second diaphragm, and the inner diameter of the second diaphragm is larger than the outer diameter of the limiting cylinder body.

9. A diaphragm valve according to claim 1, characterized in that, The hardness of the support portion is not lower than that of the deformation portion, and The thickness of the support portion is not less than that of the deformation portion.

10. A diaphragm valve according to claim 1, characterized in that, The valve body includes a base and a cover body located above the base. The first outer edge portion and the second outer edge portion are mutually attached and are pressed between the base and the cover body; Wherein, the thickness of the first outer edge portion is larger than the thickness of the deformation portion, and an avoidance portion is formed between the inner side edge of the first outer edge portion and the bottom end of the deformation portion.

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