Axial flow check valve with automatic pressure area adjustment and method of use

Abstract

This invention relates to the technical field of check valves, specifically disclosing an axial flow check valve with automatically adjustable pressure area and its usage method. The valve includes a valve body and a support. The support is located inside the valve body, with one end threadedly connected to one end of the valve body. A valve shaft is slidably mounted on the other end of the support, located in a support hole in the support. A valve disc is fixedly mounted on the end of the valve shaft away from the support. A pressure plate is screwed to the side of the valve disc closest to the support. Multiple ribs are evenly distributed around the pressure plate, located outside the support. The short shafts at the base of the ribs are supported by a support hole formed between the pressure plate and the valve disc. The long shafts of the ribs can rotate freely around their short shafts. Umbrella cloth is fixedly mounted on the multiple ribs. A spring is sleeved on the valve shaft. This invention automatically increases the pressure area when closed, providing sufficient force even under ultra-low pressure differentials to press the valve disc against the body sealing seat on the valve body, forming a reliable closing seal.

Description

Technical Field

[0001] This invention relates to the technical field of check valves, specifically to an axial flow check valve with automatically adjustable pressure area and its usage method. Background Technology

[0002] A check valve is a valve used to control the unidirectional flow of fluid. Its working principle is based on the pressure difference between the upstream and downstream fluids, which opens or closes the valve. When the pressure difference between the upstream and downstream exceeds the valve's opening pressure, the valve automatically opens, allowing fluid to flow smoothly. Conversely, when the upstream pressure is lower than the downstream pressure, the valve automatically closes, preventing backflow. Axial flow check valves are one type, characterized by energy saving, excellent sealing performance, simple installation and operation, short opening and closing stroke, compact structure, and long service life. They are widely used to prevent backflow of media.

[0003] Axial flow check valves are generally required to open under extremely low pressure differentials; the lower the opening pressure, the better. Opening the valve mainly requires overcoming the resistance of the spring that generates the initial sealing pressure, so the spring stiffness cannot be too high. The lower the spring stiffness, the lower the opening pressure. However, low spring stiffness may prevent the initial seal from being established when closing, leading to leakage. Therefore, it is often impossible to achieve both low opening pressure and good sealing performance. Summary of the Invention

[0004] To address the aforementioned problems in the prior art, this invention provides an axial flow check valve with automatically adjustable pressure area and a method for using it, which can automatically increase the pressure area when closed, and achieve rapid and reliable closure by utilizing pressure difference.

[0005] The objective of this invention can be achieved through the following technical solutions: An axial flow check valve with automatically adjustable pressure area includes a valve body and a bracket. The bracket is located inside the valve body. One end of the bracket is threadedly connected to one end of the valve body. A valve shaft is slidably mounted on the other end of the bracket. The valve shaft is located in a support hole opened in the bracket. A valve disc is fixedly mounted on the end of the valve shaft away from the bracket. A spring is sleeved on the valve shaft. The spring is located between the valve disc and the bracket. A pressure plate is fixedly installed on the side of the valve disc near the bracket. Multiple umbrella ribs are evenly distributed around the pressure plate. The multiple umbrella ribs are evenly distributed on the outer periphery of the bracket, and umbrella fabric is fixedly installed on the multiple umbrella ribs.

[0006] Furthermore, the valve disc and the pressure plate are connected by screws, the valve disc is threaded to the valve shaft, and the end of the umbrella rib near the valve disc is rotatably connected in the support hole formed by the combination of the valve disc and the pressure plate.

[0007] Furthermore, one end of the umbrella fabric near the valve disc is embedded between the valve disc and the pressure plate, and the umbrella fabric is clamped and fixed by the pressure plate and the valve disc through the screw connection.

[0008] Furthermore, the valve disc is provided with a circular arc groove with a semi-circular cross-section around its outer periphery, and the pressure plate is provided with a semi-circular cross-section protrusion concentric with the circular arc groove on the side near the valve disc, and the semi-circular cross-section protrusion cooperates with the circular arc groove.

[0009] Furthermore, the umbrella rib has a T-shaped structure. Each umbrella rib is composed of a long axis and a short axis at the root, which are fixedly connected in a T-shape near the valve flap. The contact portion between the long axis and the umbrella fabric is arc-shaped. The arc shape of the long axis matches the streamlined external shape of the support. Both the valve flap and the pressure plate are provided with T-shaped grooves that match the root of the umbrella rib. The center line of the tangential portion of the T-shaped groove is tangent to the center circle of the groove in the semi-circular cross-section. The center line of the tangential portion of the T-shaped groove is tangent to the center circle of the convex rib in the semi-circular cross-section.

[0010] Furthermore, the short shaft has an olive-shaped variable cross-section structure, and the outer contour of the short shaft matches the convex rib of the semi-circular cross-section on the pressure plate.

[0011] Furthermore, the bracket is streamlined, and the end of the valve disc away from the valve shaft is located at the upstream port of the valve body. The diameter of the end of the bracket near the upstream port is larger than the diameter of the end near the downstream port.

[0012] Furthermore, the diameter of the valve disc is larger than the diameter of the upstream port of the valve body, and the end of the valve disc near the upstream port is an outer conical surface or an outer spherical surface structure, while the valve body has a corresponding inner conical surface or inner spherical surface at the contact part with the valve disc.

[0013] Furthermore, both ends of the valve body are connected to external pipes.

[0014] A method for using an axial flow check valve with automatically adjustable pressure area includes the following steps: S1: Forward opening operation: The fluid flows into the upstream port of the valve body, pushing the valve disc to the left, compressing the spring, moving the valve shaft to the left, and allowing the fluid to flow into the downstream port. S2: Reverse flow control operation: When the downstream fluid flows back, the fluid flows into the umbrella fabric, causing the umbrella fabric and ribs to be opened. The umbrella fabric is pushed by the fluid pressure difference, and the umbrella fabric and spring together push the valve shaft and valve disc to the right. A seal is formed between the valve disc and the inner conical surface or inner spherical surface on the valve body, blocking the backflow of fluid. S3: Reopen the operation: The upstream fluid continues to push the valve disc to the left. At the moment of opening, the opened umbrella increases the upstream fluid pressure and further pushes open the valve disc area. The spring stiffness is low, the spring resistance that the medium needs to overcome is very small, and the required upstream pressure is small. The valve is opened, allowing the fluid to flow into the downstream port. As the valve opening gradually increases, a large amount of upstream fluid causes the umbrella to gradually shrink until it finally adheres completely to the support surface.

[0015] The beneficial effects of this invention are as follows: (1) By setting up a pressure plate, umbrella cloth and umbrella ribs, the technical effect that can be achieved is that the umbrella ribs are T-shaped, which is more suitable for the short shaft of the umbrella ribs to rotate in the support hole formed by the combination of the pressure plate and the valve disc. The long shaft of the umbrella ribs can rotate freely around the short shaft. When the downstream pressure is higher than the upstream pressure, the pressure difference causes the umbrella ribs and umbrella cloth to open, automatically increasing the pressure area. Under the condition of significantly reducing the spring stiffness, the valve can be closed quickly and reliably by using the pressure difference to achieve reliable reverse flow cessation. After reverse flow cessation, in the initial stage when the upstream pressure is higher than the downstream pressure, the umbrella cloth is still open and not fully contracted. The umbrella cloth that is not fully contracted plays an assisting role in opening the upstream high pressure. At the same time, because the spring stiffness can be very low, the extremely low upstream and downstream pressure difference can overcome the resistance of the very stiff spring and the frictional resistance between the valve shaft and the bracket, so as to open the valve under extremely low pressure difference. At the same time, it provides positive ultra-low opening pressure and reverse reliable check seal, avoiding the phenomenon that reverse flow cessation cannot be reliably sealed in order to obtain positive ultra-low opening pressure.

[0016] (2) By setting up a spring, valve shaft, valve disc and bracket, the technical effect that can be achieved is that the bracket is streamlined, which can play a good guiding role while supporting the valve shaft. The flow resistance is very small, which facilitates the flow of fluid. Through the compression and rebound of the spring, the valve disc is pushed to move left and right with the valve shaft, which plays the role of controlling the forward flow of fluid and the reverse cut-off.

[0017] (3) By setting up a bracket and valve shaft, the technical effect that can be achieved is that the contact surfaces of the bracket and valve shaft are treated with hardening and friction reduction, which helps to obtain both positive ultra-low opening pressure and reverse reliable check function at the same time.

[0018] (4) By setting the valve disc and valve shaft, the technical effect that can be achieved is that the end of the valve disc near the upstream port is a conical or spherical structure. The conical or spherical structure makes it easier for the fluid at the upstream port to apply pressure to the valve disc, and flow into the valve body from around the valve disc. This acts on the umbrella cloth that is still open at the beginning of opening, and has a greater force to compress the spring, which facilitates the movement of the valve shaft.

[0019] (5) By setting the umbrella ribs, the technical effect that can be achieved is that the contact part between the umbrella ribs and the umbrella cloth is arc-shaped, the arc of the long axis of the umbrella ribs matches the streamlined external shape of the support. After the valve is opened and the flow is stable, the umbrella ribs are completely contracted and closely adhered to the surface of the support, which facilitates the fluid to pass through the inside of the valve body and does not affect the flow performance in the stable open state of the valve. Attached Figure Description

[0020] To facilitate understanding by those skilled in the art, the present invention will be further described below with reference to the accompanying drawings.

[0021] Figure 1 This is a cross-sectional view of the present invention along the AA direction; Figure 2 This is a cross-sectional view of the present invention along the BB direction; Explanation of key component symbols: In the diagram: 1. Valve body; 2. Valve disc; 3. Umbrella fabric; 4. Umbrella ribs; 5. Pressure plate; 6. Bracket; 7. Valve shaft; 8. Spring; 9. Screw. Detailed Implementation

[0022] The technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0023] In the description of this application, it should be noted that the terms "upper," "lower," "inner," "outer," "top / bottom," etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0024] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installed," "equipped with," "sleeved / connected," "connected," etc., should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0025] Reference Figure 1 and Figure 2 The present invention discloses an axial flow check valve with automatically adjustable pressure area, comprising a valve body 1 and a bracket 6. The bracket 6 is located inside the valve body 1. The valve body 1 is formed by hard alloy overlay to form a body sealing seat. One end of the bracket 6 is threadedly connected to one end of the valve body 1. A valve shaft 7 is slidably disposed at the other end of the bracket 6. The valve shaft 7 is located in a support hole opened in the bracket 6. A valve disc 2 is fixedly disposed at the end of the valve shaft 7 away from the bracket 6. The valve disc 2 and the valve shaft 7 are threadedly connected and spot-welded to prevent loosening.

[0026] Multiple umbrella ribs 4 are evenly distributed around the pressure plate 5. Umbrella cloth 3 is fixedly installed on the multiple umbrella ribs 4. The multiple umbrella ribs 4 are distributed on the outside of the bracket 6. A spring 8 is sleeved on the valve shaft 7. The spring 8 is located between the valve disc 2 and the bracket 6. One end of the spring 8 is fixedly connected to the annular groove opened on the side of the valve disc 2 near the valve shaft 7. The other end of the spring 8 is fixedly connected to the bracket 6. The pressure plate 5 is fixedly installed on the side of the valve disc 2 near the valve shaft 7.

[0027] The compression and return of spring 8 push valve shaft 7 and valve disc 2 to move left and right, thereby controlling fluid flow and shutting it off.

[0028] The valve disc 2 and the pressure plate 5 are connected by screws 9. The valve disc 2 and the valve shaft 7 are connected by threads. The valve shaft 7 is located at the center of the valve disc 2. The pressure plate 5 has a circular structure. The spring 8 and the valve shaft 7 are both located inside the pressure plate 5.

[0029] The umbrella rib 4 has a T-shaped structure. One umbrella rib 4 is composed of a long axis and a short axis at the root, which are fixedly connected in a T-shape at the end near the valve flap 2. The contact part between the long axis and the umbrella fabric 3 is arc-shaped. The arc shape of the long axis axis matches the streamlined external shape of the support 6. Both the valve flap 2 and the pressure plate 5 are provided with T-shaped grooves that match the root of the umbrella rib 4. The center line of the tangential part of the T-shaped groove is tangent to the center circle of the groove of the semi-circular section. The center line of the tangential part of the T-shaped groove is tangent to the center circle of the convex rib of the semi-circular section.

[0030] The T-shaped groove on valve disc 2 includes a tangential semi-circular cross-section straight groove and a normal semi-circular cross-section straight groove, with a smooth arc transition between the two. The T-shaped groove on pressure plate 5 includes a tangential semi-circular cross-section straight groove and a normal semi-circular cross-section open groove, facilitating the free opening and closing of the long axis of umbrella rib 4 without obstruction. The short axis of umbrella rib 4 is supported by a support hole formed by the tangential straight groove on pressure plate 5 and the tangential straight groove on valve disc.

[0031] The pressure plate 5 has a ring of semi-circular cross-section raised ribs, and the center line of the tangential straight groove on the pressure plate 5 is tangent to the center circle of the raised ribs. The valve disc 2 has a ring of semi-circular cross-section grooves, and the center circle of the tangential straight groove on the valve disc 2 is tangent to the center circle of the grooves. The ring of semi-circular cross-section raised ribs on the pressure plate 5 and the ring of semi-circular cross-section grooves on the valve disc 2 cooperate to press the umbrella fabric. The multiple screws 9 that clamp and fix the pressure plate 5, the umbrella fabric 3, and the valve disc 2 are located inside the semi-circular cross-section raised ribs.

[0032] The umbrella fabric 3 and umbrella ribs 4 can automatically increase the pressure-bearing area when closed, and use the pressure difference to achieve fast and reliable closure. At the same time, it provides ultra-low opening pressure in the forward direction and reliable check seal in the reverse direction, avoiding the phenomenon of reverse flow failure due to failure to seal. After reverse flow closure, in the initial stage when the upstream pressure is higher than the downstream pressure, the umbrella fabric 3 is still in an open state and not fully contracted. The umbrella fabric 3, which is not fully contracted, plays an assisting role in opening the upstream high pressure. When opening in the forward direction, the umbrella fabric 3 and umbrella ribs 4 can overcome the resistance of the spring 8 and the frictional resistance between the valve shaft 7 and the bracket 6 through a low pressure difference, and achieve opening under extremely low pressure difference.

[0033] The support 6 is streamlined, supporting the valve shaft 7 while also providing excellent flow guidance with low flow resistance, facilitating fluid flow. The end of the valve disc 2 furthest from the valve shaft 7 is located at the upstream port of the valve body 1. The diameter of the end of the support 6 near the upstream port is larger than the diameter of its end near the downstream port. The diameter of the valve disc 2 is larger than the diameter of the upstream port of the valve body 1, and the end of the valve disc 2 near the upstream port has a conical or spherical structure.

[0034] The conical or spherical structure facilitates the flow of fluid from around the valve disc 2 into the valve body 1 when the fluid at the upstream port applies pressure to the valve disc 2. This pressure acts on the still incompletely contracted umbrella fabric, increasing the force of the compression spring 8 and facilitating the movement of the valve shaft 7. Both ends of the valve body 1 are connected to external pipes. The contact portion between the long axis of the umbrella rib 4 and the umbrella fabric 3 is arc-shaped. The arc shape of the long axis of the umbrella rib 4 matches the external streamline shape of the support 6. After the umbrella fabric 3 contracts, it facilitates the flow of fluid through the interior of the valve body 1 and prevents the umbrella rib 4 from obstructing the flow of fluid.

[0035] The contact surfaces of the bracket 6 and the valve shaft 7 are treated with hardening and friction reduction, which helps to simultaneously obtain ultra-low positive opening pressure and reliable reverse check seal.

[0036] The inner hole of the bracket 6 is specially hardened and self-lubricated to facilitate support of the guide valve shaft 7, reduce the frictional resistance of the valve shaft 7, and make it more durable.

[0037] A method for using an axial flow check valve with automatically adjustable pressure area includes the following steps: S1: Forward opening operation: The upstream fluid flows into the upstream port of valve body 1, pushing valve disc 2 to the left, compressing spring 8, moving valve shaft 7 to the left, and the fluid flows into the downstream port. S2: Reverse flow control operation: When the downstream fluid flows back, the fluid flows into the umbrella fabric 3, causing the umbrella fabric 3 and the umbrella ribs 4 to be opened. The umbrella fabric 3 is pushed by the fluid pressure difference. The umbrella fabric 3 and the spring 8 together push the valve shaft 7 and the valve disc 2 to the right. The valve disc 2 forms a seal with the inner conical surface or inner spherical surface on the valve body 1, blocking the backflow of the fluid. S3: Reopen the operation: The upstream fluid continues to push valve disc 2 to the left. At the moment of opening, the opened umbrella cloth 3 increases the upstream fluid pressure and further pushes open the area of ​​valve disc 2. The spring 8 has low stiffness, so the medium needs to overcome very little resistance from the spring 8, and the required upstream pressure is small. The valve is opened, allowing the fluid to flow into the downstream port. As the valve opening gradually increases, a large amount of upstream fluid causes the umbrella cloth 3 to gradually contract until it finally adheres completely to the surface of the bracket 6.

[0038] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. An axial flow check valve with automatically adjustable pressure area, characterized in that: The device includes a valve body and a bracket. The bracket is located inside the valve body. One end of the bracket is threadedly connected to one end of the valve body. A valve shaft is slidably mounted on the other end of the bracket. The valve shaft is located in a support hole opened in the bracket. A valve disc is fixedly mounted on the end of the valve shaft away from the bracket. A spring is sleeved on the valve shaft. The spring is located between the valve disc and the bracket. A pressure plate is fixedly installed on the side of the valve disc near the bracket. Multiple umbrella ribs are evenly distributed around the pressure plate. The multiple umbrella ribs are evenly distributed on the outer periphery of the bracket. An umbrella cloth is fixedly installed on the multiple umbrella ribs. When the downstream fluid flows back, the fluid flows into the umbrella fabric, causing the umbrella fabric and ribs to be opened. As upstream fluid flows in, the valve opening gradually increases, and the large amount of upstream fluid causes the umbrella fabric to gradually shrink until it finally adheres completely to the support surface.

2. The axial flow check valve with automatically adjustable pressure area according to claim 1, characterized in that: The valve disc and the pressure plate are connected by screws, the valve disc is threaded to the valve shaft, and the end of the umbrella rib near the valve disc is rotatably connected in the support hole formed by the combination of the valve disc and the pressure plate.

3. The axial flow check valve with automatically adjustable pressure area according to claim 2, characterized in that: The end of the umbrella fabric near the valve disc is embedded between the valve disc and the pressure plate, and the umbrella fabric is clamped and fixed by the pressure plate and the valve disc through the screw connection.

4. The axial flow check valve with automatically adjustable pressure area according to claim 1, characterized in that: The valve disc has a circular arc groove with a semi-circular cross-section around its outer periphery. The pressure plate has a semi-circular cross-section protrusion concentric with the circular arc groove on the side close to the valve disc. The semi-circular cross-section protrusion cooperates with the circular arc groove.

5. The axial flow check valve with automatically adjustable pressure area according to claim 4, characterized in that: The umbrella ribs have a T-shaped structure. Each rib is composed of a long axis and a short axis at the root, which are fixedly connected in a T-shape near the valve flap. The contact portion between the long axis and the umbrella fabric is arc-shaped. The arc shape of the long axis matches the streamlined external shape of the support. Both the valve flap and the pressure plate have T-shaped grooves that match the root of the umbrella ribs. The center line of the tangential portion of the T-shaped groove is tangent to the center circle of the groove in the semi-circular cross-section, and the center line of the tangential portion of the T-shaped groove is tangent to the center circle of the convex rib in the semi-circular cross-section.

6. The axial flow check valve with automatically adjustable pressure area according to claim 5, characterized in that: The short shaft has an olive-shaped variable cross-section structure, and the outline of the short shaft matches the convex rib of the semi-circular cross-section on the pressure plate.

7. The axial flow check valve with automatically adjustable pressure area according to claim 1, characterized in that: The bracket is streamlined, and the end of the valve disc away from the valve shaft is located at the upstream port of the valve body. The diameter of the end of the bracket near the upstream port is larger than the diameter of the end near the downstream port.

8. An axial flow check valve with automatically adjustable pressure area according to claim 7, characterized in that: The diameter of the valve disc is larger than the diameter of the upstream port of the valve body. The end of the valve disc near the upstream port is an outer conical or outer spherical structure, and the valve body has a corresponding inner conical or inner spherical surface at the contact point with the valve disc.

9. An axial flow check valve with automatically adjustable pressure area according to claim 1, characterized in that: Both ends of the valve body are connected to external pipes.

10. The method of using an axial flow check valve with automatically adjustable pressure area according to claim 1, applied to the check valve as described in any one of claims 1-9, characterized in that: Including the following steps: S1: Forward opening operation: The fluid flows into the upstream port of the valve body, pushing the valve disc to the left, compressing the spring, moving the valve shaft to the left, and allowing the fluid to flow into the downstream port. S2: Reverse flow control operation: When the downstream fluid flows back, the fluid flows into the umbrella fabric, causing the umbrella fabric and ribs to be opened. The umbrella fabric is pushed by the fluid pressure difference, and the umbrella fabric and spring together push the valve shaft and valve disc to the right. A seal is formed between the valve disc and the inner conical surface or inner spherical surface on the valve body, blocking the backflow of fluid. S3: Reopen the operation: The upstream fluid continues to push the valve disc to the left. At the moment of opening, the opened umbrella increases the upstream fluid pressure and further pushes open the valve disc area. The spring stiffness is low, the spring resistance that the medium needs to overcome is very small, and the required upstream pressure is small. The valve is opened, allowing the fluid to flow into the downstream port. As the valve opening gradually increases, a large amount of upstream fluid causes the umbrella to gradually shrink until it finally adheres completely to the support surface.

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