Miniature gravity ball type low resistance check valve

Abstract

This utility model discloses a miniature gravity ball type low-resistance check valve, relating to the field of fluid control element technology. It includes a pair of fluid interface units, a leak-proof ring, a solid gravity ball, a cylindrical cavity, a pressure ring, and an elastic rubber sealing gasket. This utility model provides a miniature gravity ball type low-resistance check valve that significantly reduces valve body size by replacing the traditional spring with a gravity ball. The valve body height can be reduced to 1.5 times the pipe diameter, and the minimum pipe diameter adaptable is 1.0 mm, meeting the compact integration requirements of micro-devices. The gravity ball uses a density-adjustable material to achieve precise adjustment of the opening pressure difference from 0.1 kPa to 8 kPa, adapting to fluid pressure requirements in various scenarios from microfluidics to industrial applications. The metal-free spring design avoids corrosion failure issues, extends the temperature resistance range to -80~200℃, and extends the lifespan to 10 years. 7 Second-rate.

Description

Technical Field

[0001] This utility model relates to the field of fluid control element technology, and in particular to a miniature gravity ball type low-resistance check valve. Background Technology

[0002] In fields such as microfluidics, biomedicine, and precision manufacturing, check valves are core components for controlling unidirectional fluid flow, and their performance directly determines the system's operational accuracy and stability. Traditional miniature check valves mostly employ spring-driven sealing structures; however, this design suffers from three major bottlenecks in practical applications, making it difficult to meet the demands of high-precision microfluidic systems: The structural characteristics of springs dictate that their minimum wire diameter is typically no less than 0.2mm. This means that in micro-scale applications with a pipe diameter of only 3mm, the valve body height must exceed 15mm, which cannot meet the space requirements of miniaturized devices and greatly limits its integrated application in miniaturized products such as portable biochemical analyzers and micro-medical devices.

[0003] Traditional springs are mostly made of metal (such as ordinary steel and copper alloys), which are prone to oxidation and corrosion in corrosive fluid environments such as acid and alkali solutions and biological reagents. This can lead to a decrease in spring elasticity or failure, which not only shortens the service life of the one-way valve, but may also cause metal ions to dissolve and contaminate the fluid medium, affecting the results of biochemical experiments or the safety of medical use.

[0004] The spring's elastic coefficient is difficult to precisely match the low flow rate requirements of micro-fluids, and its opening pressure difference is generally greater than 3 kPa, which easily causes pressure fluctuations in the micro-flow control process, resulting in a large error in flow linearity. At the same time, the spring's response delay also affects the timeliness of fluid switching, further reducing the system control accuracy.

[0005] Traditional spring-loaded check valves lack protective structures against sudden impacts from fluids. When the system experiences a sudden high-pressure impact, the spring is prone to damage due to excessive deformation, or the sealing structure may fail, which in turn affects precision instruments connected upstream, causing equipment failure or data deviation.

[0006] In addition, most existing miniature check valves lack visual monitoring functions, making it impossible to observe the internal fluid flow and the status of sealing elements in real time. Furthermore, their interface compatibility is poor, making it difficult to adapt to interface types commonly used in the microfluidics field, such as Luer locks and G1 / 8~G1 / 4 internal threads, which increases the complexity of system integration.

[0007] Therefore, developing a miniature check valve that is smaller in size, has lower resistance, stronger corrosion resistance, better impact resistance, and wider applicability has become a key requirement for solving current technical pain points. Utility Model Content

[0008] To solve the above-mentioned technical problems, this utility model provides a miniature gravity ball type low-resistance one-way valve. The technical solution is as follows: A miniature gravity ball type low-resistance one-way valve includes a pair of fluid interface units, a leak-proof ring, a solid gravity ball, a cylindrical cavity, a pressure ring, and an elastic rubber gasket. The pair of fluid interface units are respectively installed at both ends of the cylindrical cavity for connecting to external fluid interfaces. The leak-proof ring and the elastic rubber gasket are respectively used to seal the inlet and outlet of the pair of fluid interface units. The solid gravity ball is built into the cylindrical cavity, and under normal conditions, the gravity ball forms a surface contact seal with the elastic rubber gasket based on gravity. The pressure ring is installed in the cylindrical cavity to pre-press the gravity ball onto the elastic rubber gasket.

[0009] Optionally, the top of the cylindrical cavity is provided with a hemispherical buffer cavity.

[0010] Optionally, the radius of curvature R of the buffer cavity satisfies R=1.5r-2r with respect to the radius r of the gravity sphere.

[0011] Optionally, when the impact pressure of the fluid flowing in from the fluid interface unit at the bottom of the cylindrical cavity is greater than or equal to 5P_c, the gravity ball disengages from the elastic rubber sealing gasket and enters the buffer chamber. After the impact pressure is eliminated, the gravity ball automatically resets. P_c is the critical sealing pressure between the gravity ball and the elastic rubber sealing gasket.

[0012] Optionally, the gravity sphere is made of a density-adjustable material; the density adjustment range of the density-adjustable material is 2 g / cm³. 3 -16g / cm 3 The density adjustment range corresponds to the pressure difference of 0.1 kPa to 8 kPa at the critical sealing pressure.

[0013] Optionally, the density-tunable material can be achieved by using a metal core encased in an elastic layer.

[0014] Optionally, the density-tunable material can be implemented in the form of a multi-material composite sphere.

[0015] Optionally, the cylindrical cavity may be made of a high light transmittance material.

[0016] Optionally, the cylindrical cavity may be made of high-strength glass or high-transmittance plastic.

[0017] Optionally, the fluid interface unit is provided with internal threads for connection to external devices or pipes.

[0018] In summary, this utility model has at least one of the following beneficial technical effects: This invention provides a miniature gravity ball type low-resistance one-way valve. By replacing the traditional spring with a gravity ball, the valve body size is greatly reduced. The valve body height can be reduced to 1.5 times the pipe diameter, and the minimum pipe diameter can be adapted to 1.0 mm, meeting the compact integration requirements of micro devices.

[0019] The gravity ball uses a density-adjustable material to achieve precise adjustment of the opening pressure difference from 0.1kPa to 8kPa, adapting to the fluid pressure requirements of multiple scenarios from microfluidics to industrial applications.

[0020] The metal-free spring design avoids corrosion failure, extends the temperature range to -80~200℃, and has a lifespan of 10 years. 7 Second-rate; The top hemispherical buffer cavity can withstand sudden impacts of 5 times or more of the critical sealing pressure. It automatically resets after the impact is eliminated, protecting upstream equipment. The observation window on the side wall of the cavity enables real-time monitoring of the internal fluid and component status, improving ease of use. Attached Figure Description

[0021] Figure 1 This is a three-dimensional structural diagram of the miniature gravity ball type low-resistance one-way valve of this utility model; Figure 2 This is a top view schematic diagram of the miniature gravity ball type low resistance one-way valve of this utility model; Figure 3 yes Figure 2 A schematic diagram of the AA section cross-section structure.

[0022] Explanation of reference numerals in the attached drawings: 1. Fluid interface unit; 2. Leak-proof ring; 3. Gravity ball; 4. Cylindrical cavity; 41. Buffer cavity; 5. Pressure ring; 6. Elastic rubber gasket. Detailed Implementation

[0023] The present invention will be further described in detail below with reference to the accompanying drawings.

[0024] This utility model discloses a miniature gravity ball type low-resistance one-way valve.

[0025] Reference Figures 1-3 Example 1: A miniature gravity ball type low-resistance one-way valve includes a pair of fluid interface units 1, a leak-proof ring 2, a gravity ball 3, a cylindrical cavity 4, a pressure ring 5, and an elastic rubber sealing gasket 6. The pair of fluid interface units 1 are respectively installed at both ends of the cylindrical cavity 4 for connecting to external fluid interfaces. The leak-proof ring 2 and the elastic rubber sealing gasket 6 are respectively used to seal the inlet and outlet of the pair of fluid interface units 1. The gravity ball 3 is built into the cylindrical cavity 4, and under normal conditions, the gravity ball 3 forms a surface contact seal with the elastic rubber sealing gasket 6 based on gravity. The pressure ring 5 is installed in the cylindrical cavity 4 to pre-press the gravity ball 3 onto the elastic rubber sealing gasket 6.

[0026] By adopting the above technical solution, a pair of fluid interface units 1 are respectively installed at both ends of the cylindrical cavity 4, serving as the connection carrier between the one-way valve and external fluid equipment, realizing the docking of the fluid inlet and outlet channels. The leak-proof ring 2 corresponds to the sealing port of the fluid interface unit 1, preventing fluid leakage from the inlet side interface gap; the elastic rubber sealing gasket 6 corresponds to the sealing port of the fluid interface unit 1, providing a basic contact surface for the subsequent sealing of the gravity ball 3. The cylindrical cavity 4 serves as the installation and movement space for the gravity ball 3, and together with the pressure ring 5 and the elastic rubber sealing gasket 6, forms a closed internal fluid chamber, initially constructing the sealing framework of the one-way valve.

[0027] The gravity ball 3 is embedded inside the cylindrical cavity 4. Under normal conditions, it relies on its own weight to form a surface contact with the elastic rubber sealing gasket 6, initially blocking the reverse flow of fluid. The pressure ring 5 is installed inside the cylindrical cavity 4. Through its own structure, it applies pre-pressure to the gravity ball 3, pre-pressing the gravity ball 3 onto the elastic rubber sealing gasket 6. This superimposes the contact pressure between the gravity ball 3 and the elastic rubber sealing gasket 6, significantly improving the tightness of the surface contact, enhancing the sealing reliability under normal conditions, and preventing reverse leakage of fluid under low-pressure conditions.

[0028] When external fluid enters the cylindrical cavity 4 from the inlet-side fluid interface unit 1, the fluid applies positive pressure to the gravity ball 3. As the fluid pressure gradually increases, when this pressure is sufficient to overcome the sum of the gravity of the gravity ball 3 and the pre-pressure of the pressure ring 5, the gravity ball 3 will detach from the elastic rubber sealing gasket 6 and move upward within the cylindrical cavity 4, forming a fluid flow channel. At this time, the fluid can flow along the gap between the gravity ball 3 and the inner wall of the cylindrical cavity 4, and finally flow out from the outlet-side fluid interface unit 1, realizing unidirectional positive fluid flow.

[0029] When the forward fluid pressure drops to a level that cannot overcome the gravity of the gravity ball 3 and the pre-pressure of the pressure ring 5, or when reverse fluid pressure occurs, the gravity ball 3, under the combined action of its own weight and the pre-pressure of the pressure ring 5, automatically falls back onto the surface of the elastic rubber sealing gasket 6 and re-forms a tight surface contact. At the same time, the leak-proof ring 2 continuously seals the inlet side interface, and the pressure ring 5 maintains the pre-pressure state on the gravity ball 3. The three work together to prevent reverse fluid flow, ensuring that the check valve always maintains a stable one-way flow function.

[0030] Example 2: The top of the cylindrical cavity 4 is provided with a hemispherical buffer cavity 41.

[0031] In Example 3, the radius of curvature R of the buffer cavity 41 satisfies R=1.5r-2r with the radius r of the gravity sphere.

[0032] In Example 4, when the impact pressure of the fluid flowing in from the fluid interface unit 1 at the bottom of the cylindrical cavity 4 is greater than or equal to 5P_c, the gravity ball 3 disengages from the elastic rubber sealing gasket 6 and enters the buffer cavity 41. After the impact pressure is eliminated, the gravity ball 3 automatically resets. P_c is the critical sealing pressure between the gravity ball 3 and the elastic rubber sealing gasket 6.

[0033] Example 5: The gravity ball 3 is made of a density-adjustable material; the density adjustment range of the density-adjustable material is 2 g / cm³. 3 -16g / cm 3 The density adjustment range corresponds to the pressure difference of 0.1 kPa to 8 kPa at the critical sealing pressure.

[0034] By adopting the above technical solution, a hemispherical buffer cavity 41 is provided at the top of the cylindrical cavity 4. This structure provides a specific space for the movement of the gravity ball 3. As an extension structure at the top of the cylindrical cavity 4, the hemispherical design of the buffer cavity 41 is adapted to the spherical contour of the gravity ball 3. It is designed to provide temporary accommodation space for the gravity ball 3 when a sudden fluid impact occurs in the system, avoiding damage caused by the gravity ball 3 directly impacting the rigid structure at the top of the cylindrical cavity 4. At the same time, it lays the structural foundation for the subsequent repositioning of the gravity ball 3.

[0035] The radius of curvature R of the buffer cavity 41 and the radius r of the gravity ball 3 satisfy the dimensional relationship R = 1.5r - 2r. This dimensional range is precisely designed to ensure the smooth movement and reliable reset of the gravity ball 3. If R is less than 1.5r, the internal space of the buffer cavity 41 is too small, which will cause the gravity ball 3 to get stuck when it enters, and it will not be able to complete the displacement under impact smoothly. If R is greater than 2r, the internal space of the buffer cavity 41 is too large, which will cause the gravity ball 3 to shake excessively in the cavity, affecting the reset efficiency after the impact is eliminated. This radius range ensures that the gravity ball 3 can be stably accommodated after entering the buffer cavity 41, and can quickly respond to the reset action after the impact disappears.

[0036] When fluid flows in from the fluid interface unit 1 at the bottom of the cylindrical cavity 4, and the fluid impact pressure reaches or exceeds 5P_c, this pressure overcomes the critical sealing force between the gravity ball 3 and the elastic rubber sealing gasket 6 (determined by P_c), where P_c satisfies: P_c = k·G / S (k is the sealing coefficient 0.8-1.2, and S is the contact area). This pressure pushes the gravity ball 3 away from the elastic rubber sealing gasket 6 and upwards, eventually entering the buffer chamber 41. During this process, the buffer chamber 41 supports the gravity ball 3, limiting its movement and preventing excessive displacement due to excessive impact pressure. It also protects the top of the cylindrical cavity 4 and upstream connecting equipment from high-speed impacts. After the fluid impact pressure is eliminated, the gravity ball 3 falls back down along the inner wall of the cylindrical cavity 4 under its own weight, re-forming a surface contact seal with the elastic rubber sealing gasket 6, restoring the normal sealing function of the one-way valve. P_c, as the critical sealing pressure between the gravity ball 3 and the elastic rubber sealing gasket 6, is the core threshold for determining whether the impact protection action is triggered.

[0037] Gravity Sphere 3 is made of a density-adjustable material, with its density adjustment range set at 2 g / cm³. 3 -16g / cm 3 This design achieves precise control of the opening pressure difference by altering the weight of the gravity ball 3. The weight of the gravity ball 3 is directly related to the material density; the higher the density, the greater the weight of the gravity ball 3, and the greater the fluid pressure required to overcome gravity to achieve forward conduction (i.e., the opening pressure difference). Conversely, the lower the density, the smaller the weight of the gravity ball 3, and the smaller the corresponding opening pressure difference. Based on this relationship, the density adjustment range is set to 2 g / cm³. 3 -16g / cm 3 This allows the opening pressure differential of the check valve to cover a range of 0.1kPa-8kPa, thus adapting to the fluid system requirements in different scenarios. Whether it is a microfluidic scenario with low pressure requirements (requiring an opening pressure differential of 0.1kPa) or an industrial scenario with higher pressure requirements (requiring an opening pressure differential of 8kPa), precise adaptation can be achieved by adjusting the material density of the gravity ball 3.

[0038] Example 6: The density-tunable material is achieved by using a metal core encased in an elastic layer.

[0039] Example 7: The density-adjustable material is realized in the form of a multi-material composite sphere.

[0040] By adopting the above technical solution, the gravity sphere 3 achieves adjustable density through a structure of a metal core encased in an elastic layer. The overall density of the gravity sphere 3 is precisely controlled through the combination of materials and parameter adjustment of a high-density core and a low-density outer layer. Specifically, the metal core is made of a high-density metal, serving as the gravity foundation of the gravity sphere 3. Its high density ensures that the gravity sphere 3 possesses a certain initial gravity to meet the basic sealing requirements. The outer elastic layer is made of a low-density elastic material, such as fluororubber or medical-grade silicone, whose density is much lower than that of the metal core.

[0041] By adjusting the material of the metal core—different metal cores have different densities—and the volume ratio of the metal core, such as increasing the diameter of the metal core to increase the overall density and decreasing it to decrease it, or by changing the type of material of the elastic layer (different elastic materials have slightly different densities) and the thickness of the elastic layer (thickening the elastic layer decreases the overall density and thinning it increases it), the overall density of gravity sphere 3 can be made to be 2 g / cm³. 3 -16g / cm 3 The structure allows for flexible adjustment within the target range. It utilizes a metal core to ensure the basic gravity and structural stability of the gravity ball 3, while the elastic layer enables fine-tuning of the density, thus allowing the opening pressure difference of the gravity ball 3 to adapt to a range of 0.1 kPa to 8 kPa. Simultaneously, the elastic layer reduces the impact and wear when the gravity ball 3 contacts the cylindrical cavity 4 and the elastic rubber sealing gasket 6, extending the service life of the gravity ball 3.

[0042] Gravity Sphere 3 employs a multi-material composite sphere structure to achieve adjustable density. Its core functionality involves the layering and optimized proportions of various materials with different densities to precisely control the overall density. This structure typically employs a multi-layered concentric design, with each layer using materials exhibiting significant density differences, such as a high-density tungsten alloy layer, a medium-density titanium alloy layer, and a low-density engineering plastic layer. By adjusting the thickness ratio of these different density material layers, the overall density of Gravity Sphere 3 is altered.

[0043] For example, when it is necessary to increase the overall density of gravity sphere 3, the thickness of the high-density material layer, such as the tungsten alloy layer, can be increased while the thickness of the low-density material layer can be decreased; conversely, when it is necessary to decrease the overall density, the opposite can be done, increasing the thickness of the low-density material layer and decreasing the thickness of the high-density material layer. Through this flexible design of the layering ratio, the overall density of gravity sphere 3 can be stably controlled at 2 g / cm³. 3 -16g / cm 3Within the range. In addition, the multi-material composite structure can combine the characteristics of different materials. For example, the titanium alloy layer can be used to improve the corrosion resistance of the gravity ball 3, and the engineering plastic layer can be used to reduce the friction coefficient between the gravity ball 3 and the elastic rubber sealing gasket 6. While achieving adjustable density, the sealing performance, weather resistance and smooth movement of the gravity ball 3 can be further optimized, ultimately ensuring that the opening pressure difference corresponding to the gravity ball 3 is accurately adapted to the multi-scenario requirements of 0.1kPa-8kPa.

[0044] Example 8: The cylindrical cavity 4 is made of a high light transmittance material.

[0045] Example 9: The cylindrical cavity 4 is made of high-strength glass or high-transmittance plastic.

[0046] By adopting the above technical solution, the cylindrical cavity 4 is made of high-strength glass or high-transmittance plastic, providing a visual monitoring channel for the internal working conditions of the check valve. The cylindrical cavity 4 serves as the carrier for the movement and sealing of the gravity ball 3. The working state of the gravity ball 3 inside, such as whether it is tightly fitted with the elastic rubber sealing gasket 6 under normal conditions, whether it smoothly detaches from the elastic rubber sealing gasket 6 during forward flow, whether it accurately enters the buffer chamber 41 under impact conditions, and whether it reliably resets after the impact is eliminated, as well as the fluid flow state, such as whether there is local stagnation or leakage, all directly affect the working performance of the check valve and the safety of the system.

[0047] This design breaks the closed structure limitations of the cylindrical cavity 4, allowing operators to directly observe the dynamics of the internal core components and fluid conditions without disassembling the check valve. When the gravity ball 3 becomes stuck, fails to seal, or exhibits abnormal fluid flow, the problem can be quickly detected, enabling timely repairs or adjustments. This prevents system downtime or equipment damage due to undetected internal faults, while also reducing time costs and component wear caused by disassembly and inspection, ensuring the continuous and stable operation of the fluid system associated with the check valve.

[0048] Example 10: The fluid interface unit 1 is provided with an internal thread for connecting to external devices or pipes.

[0049] By adopting the above technical solution, the fluid interface unit 1 is provided with an internal thread of G1 / 8~G1 / 4, which facilitates the connection of external equipment or pipelines; by adapting to two mainstream external interface structures, the fluid interface unit 1 can achieve direct and reliable docking with external fluid equipment in different scenarios.

[0050] The above are all preferred embodiments of this utility model, and are not intended to limit the scope of protection of this utility model. Therefore, all equivalent changes made according to the structure, shape and principle of this utility model should be covered within the scope of protection of this utility model.

Claims

1. A miniature gravity ball type low-resistance check valve, characterized in that: The device includes a pair of fluid interface units (1), a leak-proof ring (2), a gravity ball (3), a cylindrical cavity (4), a pressure ring (5), and an elastic rubber gasket (6). The pair of fluid interface units (1) are respectively installed at both ends of the cylindrical cavity (4) for connecting to external fluid interfaces. The leak-proof ring (2) and the elastic rubber gasket (6) are respectively used to seal the inlet and outlet of the pair of fluid interface units (1). The gravity ball (3) is built into the cylindrical cavity (4), and the gravity ball (3) forms a surface contact seal with the elastic rubber gasket (6) under normal conditions based on gravity. The pressure ring (5) is installed in the cylindrical cavity (4) to pre-press the gravity ball (3) onto the elastic rubber gasket (6).

2. The micro-gravball low resistance one-way valve of claim 1, wherein: The top of the cylindrical cavity (4) is provided with a hemispherical buffer cavity (41).

3. The micro-graviton ball low resistance one-way valve according to claim 2, wherein: The radius of curvature R of the buffer cavity (41) satisfies R=1.5r-2r with the radius r of the gravity sphere.

4. The micro-graviton ball low resistance one-way valve according to claim 3, wherein: When the impact pressure of the fluid flowing in from the fluid interface unit (1) at the bottom of the cylindrical cavity (4) is greater than or equal to 5P_c, the gravity ball (3) detaches from the elastic rubber sealing gasket (6) and enters the buffer chamber (41). After the impact pressure is eliminated, the gravity ball (3) automatically resets. P_c is the critical sealing pressure between the gravity ball (3) and the elastic rubber sealing gasket (6).

5. The micro-graviton ball low resistance one-way valve according to claim 4, wherein: The gravity ball (3) is made of a material with adjustable density; the density adjustment range of the material with adjustable density is 2g / cm 3 -16g / cm 3 , and the differential pressure corresponding to the opening critical sealing pressure is 0.1kPa-8kPa.

6. The micro-gravball low resistance one-way valve of claim 5, wherein: The density-tunable material is achieved by using a metal core encased in an elastic layer.

7. The micro-gravball low resistance one-way valve of claim 6, wherein: The density-tunable material is achieved in the form of a multi-material composite sphere.

8. The micro-gravball low resistance one-way valve of claim 7, wherein: The cylindrical cavity (4) is made of a high light transmittance material.

9. The micro-gravball low resistance one-way valve of claim 8, wherein: The cylindrical cavity (4) is made of high-strength glass or high-transmittance plastic.

10. The micro-gravball low resistance one-way valve of claim 9, wherein: The fluid interface unit (1) is provided with internal threads for connection to external equipment or pipes.

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