A diaphragm type check valve

Abstract

The utility model relates to valve technical field, concretely is a kind of diaphragm type check valve, including upper valve body, diaphragm and lower valve body, upper valve body is detachably connected with lower valve body, diaphragm is clamped between upper valve body and lower valve body;The side of upper valve body towards diaphragm is equipped with local sunken area, the surface of local sunken area is processed as rough surface;The lamination surface of diaphragm towards upper valve body and the corresponding lamination surface of upper valve body are all polished to form polished lamination surface.The diaphragm type check valve, by the design of "diaphragm and upper valve body corresponding lamination surface are all polished", greatly reduce the roughness of lamination surface, eliminate micron-level gap of existing conventional machining surface, both guarantee the control accuracy of medical infusion dose, water purifier water supply and other scenes, and avoid the security risk caused by leakage.

Description

Technical Field

[0001] This utility model relates to the field of valve technology, and more specifically, to a diaphragm check valve. Background Technology

[0002] In the field of fluid control, check valves, as core components for preventing fluid backflow, are mainly divided into two categories: spring-loaded check valves and diaphragm check valves. Spring-loaded check valves rely on spring force to reset the valve core, but they have two major limitations: first, the opening pressure is relatively high, typically requiring a fluid pressure of 3-6 kPa to overcome the spring resistance, making it difficult to meet the needs of low-pressure applications (such as micro-flow rate control in medical infusions and low-pressure water supply in small water purifiers); second, the mechanical friction between the valve core and the valve seat, as well as spring vibration, generate significant noise, making them unsuitable for noise-sensitive environments such as home and medical settings.

[0003] To address the aforementioned issues, diaphragm check valves have gradually become the mainstream choice for low-pressure, low-noise applications. The basic structure of existing diaphragm check valves typically includes an upper valve body, a lower valve body, and an elastic diaphragm sandwiched between them. Its working principle is as follows: when fluid flows in from the inlet channel of the lower valve body, the fluid pressure pushes the diaphragm upwards to adhere to the contact surface of the upper valve body, achieving a reverse seal through the tight contact between the diaphragm and the valve body; when fluid flows in the reverse direction from the outlet channel of the upper valve body, the fluid pressure pushes the diaphragm apart from the upper valve body, forming a flow channel and achieving unidirectional flow. Compared to spring-loaded check valves, existing diaphragm check valves can reduce the opening pressure to 0.2-0.3 kPa, and without spring mechanical friction, operating noise is significantly reduced. Therefore, they are widely used in scenarios such as unidirectional drug delivery in medical infusion sets, reverse osmosis membrane protection in household water purifiers, and pneumatic circuit control in small pneumatic equipment.

[0004] However, existing diaphragm check valves still have two major shortcomings that urgently need to be addressed in practical applications: Insufficient sealing reliability: In existing technologies, the contact surfaces between the diaphragm and the upper valve body are mostly conventionally machined surfaces without special precision polishing treatment. The contact surfaces have micron-level rough protrusions or gaps. When the fluid is under low pressure conditions (such as the low flow rate of medical infusion), the tiny gaps can easily lead to fluid leakage, which not only affects the accuracy of fluid control (such as infusion dosage deviation) but may also cause safety risks (such as drug contamination in medical scenarios).

[0005] Diaphragm adhesion and unstable opening pressure: Currently, the surfaces of the upper valve body and the diaphragm are mostly flat, without special anti-adhesion designs. When the equipment is idle or operating at low load for extended periods, the elastic diaphragm and the flat surface of the upper valve body are prone to adhesion due to intermolecular forces or the viscosity of residual fluid. After adhesion, the fluid needs to overcome additional "adhesive force" to push the diaphragm open, resulting in a significant increase in actual opening pressure (in some scenarios, it can rise above 1 kPa, far exceeding the designed 0.2-0.3 kPa). Furthermore, the degree of adhesion varies with each opening, causing opening pressure fluctuations of ±0.5 kPa or more, severely affecting the consistency of equipment operation—for example, in pneumatic actuators, unstable opening pressure can lead to delayed or jammed actuator movements; in water purifiers, it can result in insufficient inlet water pressure for the filter cartridge and reduced filtration efficiency. Utility Model Content

[0006] The purpose of this utility model is to provide a diaphragm-type check valve to solve the problem mentioned in the background art that the contact surface between the diaphragm and the upper valve body is mostly a conventionally machined surface without special precision polishing, resulting in micron-level roughness, protrusions, or gaps on the contact surface.

[0007] To achieve the above objectives, this utility model provides a diaphragm-type check valve, comprising an upper valve body, a diaphragm, and a lower valve body, wherein the upper valve body and the lower valve body are detachably connected, and the diaphragm is clamped between the upper valve body and the lower valve body; The upper valve body has a partially sunken area on the side facing the diaphragm, and the surface of the partially sunken area is processed to have a rough texture. The diaphragm's contact surface facing the upper valve body and the corresponding contact surface of the upper valve body are both polished to form polished contact surfaces. The diaphragm can be attached to or separated from the contact surface of the upper valve body under fluid pressure, achieving one-way sealing and conduction.

[0008] The technical benefits of this design are concentrated in three aspects: First, the design of "polishing the corresponding contact surfaces of the diaphragm and the upper valve body" significantly reduces the roughness of the contact surfaces, eliminating the micron-level gaps of conventionally machined surfaces. Even under low-pressure conditions of 0.2-0.3 kPa, fluid leakage can be avoided, ensuring control accuracy in scenarios such as medical infusion dosage and water purifier supply, while also mitigating safety risks caused by leakage. Second, the combined structure of "a partially recessed area on the upper valve body + a rough textured surface" allows the recessed area to form a fluid buffer space, while the rough textured surface reduces the contact area between the diaphragm and the valve body. This dual effect solves the problem of diaphragm adhesion, making... The opening pressure is stably maintained within the design range of 0.2-0.3 kPa, with a fluctuation range of ≤ ±0.1 kPa (far superior to the ±0.5 kPa fluctuation of existing technologies), meeting the requirements of pneumatic actuators, water purifiers, and other applications for stable opening pressure. Thirdly, the structure of "detachable connection between upper and lower valve bodies and diaphragm clamping and positioning" simplifies assembly and diaphragm replacement and maintenance, and ensures that the diaphragm only adheres or separates along the vertical direction of the mating surface, avoiding sealing failure or poor conduction caused by displacement deviation. This ensures the stability of the one-way valve's core functions of "reverse sealing and forward conduction," making it suitable for long-term use in various scenarios such as medical, household, and small industrial equipment.

[0009] Preferably, the upper valve body and the lower valve body are fixedly connected by adhesive dispensing or detachably connected by snap-fit.

[0010] Preferably, the surface roughness Ra of the rough textured surface is 1.6 μm to 6.3 μm.

[0011] Preferably, the surface roughness Ra of the polished mating surface between the diaphragm and the upper valve body is ≤0.8μm.

[0012] Preferably, the diaphragm is made of an elastic material, which is selected from silicone rubber, fluororubber, or nitrile rubber.

[0013] Preferably, the depth of the local sunken area of ​​the upper valve body is 0.5mm to 2mm, and the projected area of ​​the local sunken area is not less than 1 / 3 of the effective contact area of ​​the diaphragm.

[0014] Preferably, the lower valve body is provided with a fluid inlet channel, and the upper valve body is provided with a fluid outlet channel. The fluid inlet channel of the lower valve body and the local sinking area of ​​the upper valve body are correspondingly arranged on the fluid flow path.

[0015] Preferably, the rough textured surface is an annular rough structure or a mesh-like rough structure, and the protrusion height of the rough textured surface is 0.1 mm to 0.5 mm.

[0016] Compared with the prior art, the beneficial effects of this utility model are as follows: The technological advantages of this diaphragm-type check valve are concentrated in three aspects: First, the design of "polishing the corresponding contact surfaces of the diaphragm and the upper valve body" significantly reduces the roughness of the contact surfaces, eliminating the micron-level gaps of conventionally machined surfaces. Even under low-pressure conditions of 0.2-0.3 kPa, fluid leakage can be avoided, ensuring control accuracy in scenarios such as medical infusion dosage and water purifier supply, while also avoiding safety risks caused by leakage. Second, the combination structure of "a localized recessed area on the upper valve body + a rough textured surface" effectively solves the problem of diaphragm adhesion by using the recessed area to form a fluid buffer space and the rough textured surface to reduce the contact area between the diaphragm and the valve body. This design ensures that the opening pressure is stably maintained within the design range of 0.2-0.3 kPa, with a fluctuation range of ≤ ±0.1 kPa (far superior to the ±0.5 kPa fluctuation of existing technologies), meeting the requirements of pneumatic actuators, water purifiers, and other applications for stable opening pressure. Thirdly, the structure of "detachable connection between the upper and lower valve bodies and diaphragm clamping and positioning" simplifies assembly and diaphragm replacement and maintenance, while ensuring that the diaphragm only adheres or separates along the vertical direction of the mating surface. This avoids sealing failure or poor conduction caused by displacement deviation, guaranteeing the stability of the check valve's core functions of "reverse sealing and forward conduction," making it suitable for long-term use in various scenarios such as medical, household, and small industrial equipment. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the exploded structure of this utility model; Figure 2 This is a schematic diagram of the internal structure of the present invention; The meanings of the labels in the diagram are as follows: 1. Upper valve body; 11. Locally sunken area; 12. Rough textured surface; 13. Fluid outlet channel; 2. Diaphragm; 21. Polished bonding surface; 22. Fluid inlet channel; 3. Lower valve body. Detailed Implementation

[0018] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0019] This utility model provides a diaphragm-type check valve, such as Figures 1-2 As shown, it includes an upper valve body 1, a diaphragm 2 and a lower valve body 3. The upper valve body 1 and the lower valve body 3 are detachably connected, and the diaphragm 2 is clamped between the upper valve body 1 and the lower valve body 3. The upper valve body 1 has a partially sunken area 11 on the side facing the diaphragm 2, and the surface of the partially sunken area 11 is processed into a rough textured surface 12; the contact surface of the diaphragm 2 facing the upper valve body 1 and the corresponding contact surface of the upper valve body 1 are both polished to form a polished contact surface 21, and the diaphragm 2 can be attached to or separated from the contact surface of the upper valve body 1 under the action of fluid pressure to achieve one-way sealing and conduction.

[0020] The basic structure of "detachable connection of upper valve body 1 and lower valve body 3 + clamping and positioning of diaphragm 2" breaks through the limitation of existing one-way valves that "diaphragm replacement requires complete disassembly," providing a structural basis for subsequent maintenance. On the other hand, the clamping design restricts the diaphragm to move only in the vertical direction of the mating surface, avoiding "seal misalignment" or "conduction blockage" caused by diaphragm displacement in existing technologies, ensuring the stable realization of the core functions of the one-way valve: "reverse sealing and forward conduction." The localized recessed area 11 of the upper valve body 1 can form an independent buffer space when fluid flows in forward, solving the problem of "pressure dispersion caused by direct fluid impact on the diaphragm" in existing flat valve bodies. This allows the fluid to quickly fill and evenly act on the diaphragm, providing sufficient pressure for subsequent diaphragm opening and structurally avoiding the risk of "diaphragm not being able to separate due to insufficient pressure." The polished mating surface 21 of the diaphragm 2 and the upper valve body 1 is optimized for microscopic flatness (Ra≤0.8μm in subsequent embodiments), eliminating the micron-level gaps of conventionally machined surfaces. Even under low-pressure conditions of 0.2-0.3kPa, the diaphragm and the valve body can be tightly fitted, completely blocking the fluid leakage channel and ensuring the sealing reliability of low-pressure scenarios such as medical treatment and water purification.

[0021] In this embodiment, the upper valve body 1 and the lower valve body 3 are fixedly connected by adhesive dispensing or detachably connected by snap-fit. The surface roughness Ra of the rough textured surface 12 is 1.6μm to 6.3μm. The surface roughness Ra of the polished bonding surface 21 of the diaphragm 2 and the upper valve body 1 is ≤0.8μm. The diaphragm 2 is made of an elastic material, which is selected from silicone rubber, fluororubber, or nitrile rubber. The depth of the local recessed area 11 of the upper valve body 1 is 0.5mm to 2mm, and the projected area of ​​the local recessed area 11 is not less than 1 / 3 of the effective bonding area of ​​the diaphragm 2.

[0022] "Dispensing-fixed connection" is designed for scenarios with high sealing requirements (such as medical infusion sets). By filling gaps with adhesive, it further improves the overall sealing performance and avoids minor leaks that may occur with detachable connections. "Snap-on detachable connection" is suitable for scenarios requiring frequent maintenance (such as bypass valves for water purifier filters), enabling quick diaphragm replacement and solving the problem of existing technologies having "a single connection method that cannot adapt to multiple scenarios." The parameter setting of Ra≤0.8μm for the polished bonding surface ensures that the height of the microscopic protrusions on the bonding surface is much smaller than the gaps between fluid molecules, preventing low-pressure fluid from leaking through the gaps. Compared with the existing surface Ra≥1.6μm, the sealing reliability is improved by at least 30%. The parameter of Ra=1.6μm-6.3μm for the rough textured surface reduces the contact area between the diaphragm and the valve body (reducing the probability of adhesion) through moderate roughness, while avoiding excessive roughness that would increase fluid flow resistance, achieving a balance between "anti-adhesion" and "low resistance." The selection of silicone rubber, fluororubber, and nitrile rubber materials is suitable for medical scenarios (biocompatibility), highly corrosive scenarios (acid and alkali resistance), and conventional water / gas scenarios (low cost and durability), respectively, solving the defect of "narrow applicable scenarios" of existing ordinary rubber diaphragms; the depth of the local sinking area of ​​0.5mm-2mm and the parameter of "projected area ≥ 1 / 3 of the effective adhesion area of ​​the diaphragm" ensure that the buffer space is large enough to accommodate the fluid, avoid insufficient fluid pressure due to insufficient space, and further ensure that the diaphragm can separate stably.

[0023] Furthermore, the lower valve body 3 is provided with a fluid inlet channel 22, and the upper valve body 1 is provided with a fluid outlet channel 13. The fluid inlet channel 22 of the lower valve body 3 and the local sunken area 11 of the upper valve body 1 are correspondingly arranged on the fluid flow path. The rough texture 12 is an annular rough structure or a mesh-like rough structure, and the protrusion height of the rough texture 12 is 0.1mm to 0.5mm.

[0024] The fluid inlet channel 22 of the lower valve body 3 corresponds to the flow path of the local sinking area 11 of the upper valve body 1, allowing the fluid to flow directly into the sinking area after exiting the inlet channel. This avoids the problem of "fluid dispersion and pressure loss due to channel misalignment" in existing technologies—improving fluid pressure transmission efficiency by more than 20%, accelerating diaphragm separation response speed, and reducing fluid retention within the valve body, thus lowering the risk of secondary adhesion caused by fluid residue. The annular rough structure adapts to the circular diaphragm, ensuring uniform fluid distribution along the annulus and avoiding uneven deformation caused by excessive local stress on the diaphragm. The grid-like rough structure increases the contact area between the fluid and the diaphragm, resulting in better propulsion for high-viscosity fluids (such as pharmaceutical solutions and viscous liquids), solving the problem of "poor adaptability to fluids of different viscosities" of existing irregular rough surfaces. The rough texture with a protrusion height of 0.1mm-0.5mm not only supports the diaphragm and reduces the bonding area (preventing adhesion), but also avoids the formation of vortices or resistance when the fluid flows through due to excessive protrusion. Compared with the existing structure with a protrusion height ≥0.6mm, the fluid flow resistance is reduced by 15%-25%, achieving a dual optimization of "anti-adhesion" and "low flow resistance".

[0025] When the diaphragm-type check valve of this utility model is in use, firstly, when the fluid flows in along the "fluid outlet channel 13 of the upper valve body 1 → space between the upper valve body and the diaphragm 2", the fluid pressure acts on the upper surface of the diaphragm 2 (the side facing upward), generating a downward thrust. The process is divided into three steps: Because the path of the lower valve body inlet channel 22 corresponds to the path of the upper valve body local sinking area 11, the inflowing fluid preferentially fills the local sinking area 11. The spatial design of this area (depth 0.5-2mm) can quickly accommodate the fluid, avoiding "the fluid directly impacting the diaphragm, causing pressure dispersion", and forming a uniform downward pressure. The rough texture 12 (ring-shaped / grid-shaped, raised 0.1-0.5mm) on the surface of the local sinking area 11 significantly reduces the actual contact area between the diaphragm 2 and the upper valve body 1, reduces the influence of intermolecular adhesion force and residual fluid viscosity, so that the fluid pressure can easily push the diaphragm 2 to deform downward without having to overcome additional "adhesion resistance". Formation of flow channel: After the diaphragm 2 separates downward, it detaches from the polished bonding surface of the upper valve body 1, forming a complete flow path of "upper valve body outlet channel 13 → local sinking area 11 → gap between diaphragm and lower valve body → lower valve body inlet channel 22", and the fluid flows out smoothly along this path; The raised height of the rough textured surface (0.1-0.5mm) avoids excessively high protrusions from generating fluid vortices. Compared with existing structures with protrusions ≥0.6mm, the flow resistance is reduced by 15%-25%. At the same time, the fluid pressure transmission efficiency is improved by more than 20%, the membrane separation response speed is accelerated, and there is no fluid retention, reducing the risk of secondary adhesion.

[0026] The foregoing has shown and described the basic principles, main features, and advantages of this utility model. Those skilled in the art should understand that this utility model is not limited to the above embodiments. The embodiments and descriptions in the specification are merely preferred examples and are not intended to limit the utility model. Various changes and modifications can be made to this utility model without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed utility model. The scope of protection of this utility model is defined by the appended claims and their equivalents.

Claims

1. A diaphragm check valve characterized by: It includes an upper valve body (1), a diaphragm (2) and a lower valve body (3), wherein the upper valve body (1) and the lower valve body (3) are detachably connected, and the diaphragm (2) is clamped between the upper valve body (1) and the lower valve body (3); The upper valve body (1) has a local sunken area (11) on the side facing the diaphragm (2), and the surface of the local sunken area (11) is processed into a rough textured surface (12). The diaphragm (2) and the corresponding contact surface of the upper valve body (1) are both polished to form a polished contact surface (21). The diaphragm (2) can be attached to or separated from the contact surface of the upper valve body (1) under fluid pressure to achieve one-way sealing and conduction.

2. The flapper check valve of claim 1, wherein: The upper valve body (1) and the lower valve body (3) are fixedly connected by adhesive or detachably connected by clips.

3. The diaphragm check valve according to claim 1, characterized in that: The surface roughness Ra of the rough textured surface (12) is 1.6 μm to 6.3 μm.

4. The diaphragm check valve according to claim 1, characterized in that: The surface roughness Ra of the polished mating surface (21) of the diaphragm (2) and the upper valve body (1) is ≤0.8μm.

5. The flapper check valve of claim 1, wherein: The diaphragm (2) is made of an elastic material selected from silicone rubber, fluororubber or nitrile rubber.

6. The flapper check valve of claim 1, wherein: The depth of the local sinking area (11) of the upper valve body (1) is 0.5mm to 2mm, and the projected area of ​​the local sinking area (11) is not less than 1 / 3 of the effective bonding area of ​​the diaphragm (2).

7. The flapper check valve of claim 1, wherein: The lower valve body (3) is provided with a fluid inlet channel (22), and the upper valve body (1) is provided with a fluid outlet channel (13). The fluid inlet channel (22) of the lower valve body (3) and the local sinking area (11) of the upper valve body (1) are correspondingly set on the fluid flow path.

8. The diaphragm check valve according to claim 1, characterized in that: The rough textured surface (12) is an annular rough structure or a mesh-like rough structure, and the protrusion height of the rough textured surface (12) is 0.1 mm to 0.5 mm.

Images