An automatic exhaust device

Abstract

The utility model provides a kind of automatic exhaust device, belong to fluid delivery pipe network system exhaust technical field, the automatic exhaust device includes valve body, valve cover, casing, float and rain cover, rain cover is located above valve body, further include anti-suckback component;Valve body includes first valve body and second valve body, fluid inlet is provided on second valve body;Valve cover is installed between first valve body and second valve body, and the central hole of valve cover is opened, which is communicated with first valve body and second valve body;Casing is arranged in second valve body and is communicated with second valve body, float is located in casing and can be lifted to block central hole under the action of fluid buoyancy;Anti-suckback component is arranged above valve cover, for when forming negative pressure in second valve body, prevent air suckback.The utility model solves the problem that existing automatic exhaust device cannot prevent air suckback into pipe network when negative pressure occurs in water inlet pipe network system.

Description

Technical Field

[0001] This utility model relates to the field of exhaust technology for fluid transport pipeline systems, and in particular to an automatic exhaust device. Background Technology

[0002] Automatic air venting devices are crucial for ensuring the safe and stable operation of various pipeline systems. Their core function is to promptly remove air from the pipeline network during filling and normal water flow, preventing air accumulation that could lead to pump cavitation, pressure fluctuations, and other problems, thus ensuring the safe operation of pumps and other core equipment, as well as the entire pipeline system.

[0003] like Figure 1 and 2 As shown, existing automatic air venting devices typically include a valve body 2', a valve cover 4', a protective sleeve 3', a float 5', and a rain cover 1'. During the process of the water inlet network system transitioning from an empty pipe to a water supply system, gas in the network enters the valve body 2' through the lower inlet of the automatic air venting device and is then discharged through the vent port of the valve cover 4'. Once all the gas in the pipeline is expelled, water enters the valve body 2'. As the water level in the protective sleeve 3' rises, the float 5' rises with the water level due to buoyancy. This continues until the automatic air venting device is filled with water, and under the pressure of the inlet network, the float 5' blocks the vent port, preventing water from flowing out of the automatic air venting device.

[0004] However, this conventional device has significant drawbacks. Under certain operating conditions, such as when the pump is stopped and the inlet is under positive pressure, but due to the small positive pressure or long pipeline, a large pressure drop occurs in the inlet pipeline after the pump starts, which may cause the pressure at the pump inlet to be lower than atmospheric pressure, creating a negative pressure (vacuum). At this time, the float 4 inside the conventional venting device, whose sealing force mainly relies on buoyancy (i.e., internal liquid pressure), will have its sealing effect weakened or even fail under the action of internal negative pressure. External air will be drawn into the pipeline network under atmospheric pressure, causing unstable pump operation, cavitation, vibration, and noise, and in severe cases, damage to the pump and pipeline system.

[0005] In view of this, the present invention provides a new solution to the above problems. Utility Model Content

[0006] The purpose of this invention is to provide an automatic air venting device that solves the problem that existing automatic air venting devices cannot prevent air from being sucked back into the water inlet network when negative pressure occurs in the water inlet network system.

[0007] The above-mentioned technical objective of this utility model is achieved through the following technical solution.

[0008] An automatic exhaust device includes a valve body, a valve cover, a protective sleeve, a float ball, and a rain cover, wherein the rain cover is located above the valve body, and also includes an anti-backflow component;

[0009] The valve body includes a first valve body and a second valve body, and the second valve body is provided with a fluid inlet;

[0010] The valve cover is installed between the first valve body and the second valve body, and the valve cover has a central hole that connects the first valve body and the second valve body.

[0011] The protective sleeve is disposed within the second valve body and communicates with the second valve body. The float is located inside the protective sleeve and can rise under the action of fluid buoyancy to block the central hole.

[0012] The anti-backflow component is located above the valve cover and is used to prevent air backflow when a negative pressure is formed in the second valve body.

[0013] A further preferred embodiment is that the anti-backflow component includes:

[0014] A support frame is installed inside the first valve body;

[0015] The guide rod is vertically and movably inserted through the support frame;

[0016] A vacuum valve disc, fixed to the upper end of the guide rod, is used to block the exhaust port at the top of the first valve body;

[0017] A spring, sleeved on the guide rod, provides a preload force to the vacuum valve disc toward the exhaust port, so that the vacuum valve disc tends to close toward the exhaust port.

[0018] A further preferred embodiment includes an adjusting nut;

[0019] The upper end of the guide rod passes through the vacuum valve disc and is locked by the adjusting nut. Rotating the adjusting nut can change the pre-compression of the spring.

[0020] A further preferred embodiment is that a first sealing gasket is provided between the adjusting nut and the vacuum valve disc.

[0021] A further preferred embodiment includes a retaining nut;

[0022] The lower end of the guide rod is threadedly connected to the fixing nut. The spring is located between the support frame and the fixing nut, with its upper end abutting against the support frame and its lower end abutting against the fixing nut.

[0023] A further preferred embodiment is that the support frame includes a support ring, a support rod, and a sleeve, the support ring is fixed around the inner wall of the first valve body, the support rod is connected between the support ring and the sleeve, and the sleeve is fitted onto the guide rod.

[0024] A further preferred embodiment is that the inner diameter of the upper part of the exhaust port gradually increases from bottom to top to form a conical sealing surface;

[0025] The lower end face of the vacuum valve disc is adapted to the conical sealing surface so that a surface seal is formed when the vacuum valve disc is in contact with the exhaust port.

[0026] A further preferred embodiment is that an O-ring is provided between the vacuum valve disc and the conical sealing surface.

[0027] A further preferred embodiment is that the valve cover is detachably installed between the first valve body and the second valve body.

[0028] A further preferred embodiment is that a second sealing gasket is provided at the bottom of the valve cover, and the second sealing gasket surrounds the central hole;

[0029] The upper end of the protective sleeve abuts against the valve cover and the second valve body, and a third sealing gasket is provided between the valve cover, the second valve body, and the protective sleeve;

[0030] A fourth sealing gasket is provided between the protective sleeve and the second valve body, so that the top surface of the upper end of the protective sleeve abuts against the third sealing gasket and the bottom surface abuts against the fourth sealing gasket.

[0031] In summary, this utility model has the following beneficial effects:

[0032] The automatic exhaust device of this utility model includes a valve body, a valve cover, a protective sleeve, a float, and a rain cover. The rain cover is located above the valve body and also includes an anti-backflow component. The valve body includes a first valve body and a second valve body, with a fluid inlet on the second valve body. The valve cover is installed between the first and second valve bodies and has a central hole connecting the first and second valve bodies. The protective sleeve is disposed within and communicates with the second valve body. The float is located within the protective sleeve and can rise under the buoyancy of the fluid to block the central hole. The anti-backflow component is located above the valve cover and is used to prevent air backflow when a negative pressure is formed within the second valve body.

[0033] When the inlet pipe is under positive pressure, gas can quickly enter the first valve body from the second valve body through the central hole that runs vertically through it, and finally be discharged from the venting structure of the first valve body. This avoids problems such as pressure fluctuations and pump cavitation caused by gas accumulation in the pipeline network, ensuring the stable operation of the pipeline system. When the gas in the second valve body is exhausted and the fluid is full, the float rises along the inner wall of the protective sleeve under the action of fluid buoyancy until it precisely seals the central hole, blocking the flow between the first and second valve bodies and preventing fluid leakage. The entire process requires no manual intervention, realizing automated switching between venting and sealing, improving the reliability and intelligence of the device operation. In addition, the limiting effect of the protective sleeve on the float can prevent the float from deviating due to water flow impact, ensuring that the float always moves along the preset trajectory, further ensuring the accuracy of the central hole sealing and reducing the risk of seal failure.

[0034] When changes in pipeline conditions cause negative pressure to form within the second valve body, the anti-backflow component can quickly block the passage for outside air to be drawn back into the second valve body through the first valve body. If air is drawn back into the pipeline, it may cause abnormal pump noise, cavitation, increased vibration, or even damage to the pump equipment. This anti-backflow component effectively avoids such problems, ensuring the safe operation of downstream equipment (such as pumps) and reducing equipment maintenance costs. Furthermore, the anti-backflow component allows the device to not only perform conventional venting but also adapt to negative pressure conditions in the pipeline, expanding its applicable scenarios and enhancing its adaptability to complex pipeline environments. This solves the problem that existing automatic venting devices cannot prevent air from being drawn back into the pipeline when negative pressure occurs in the inlet water network system. Attached Figure Description

[0035] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this utility model and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0036] Figure 1 This is a cross-sectional schematic diagram of an automatic exhaust device in the prior art under normal conditions;

[0037] Figure 2 This is a cross-sectional schematic diagram of an automatic exhaust device in the prior art during exhaust.

[0038] Figure 3 This is a schematic diagram of the overall structure of an automatic exhaust device according to a preferred embodiment of the present invention;

[0039] Figure 4 This is a side view of the automatic exhaust device according to a preferred embodiment of the present invention.

[0040] Figure 5 This is a cross-sectional schematic diagram of an automatic exhaust device according to a preferred embodiment of the present invention;

[0041] Figure 6 yes Figure 5 Enlarged view of the A-structure in the middle;

[0042] Figure 7 yes Figure 5 Enlarged view of the B-structure;

[0043] Figure 8 This is a schematic diagram of the anti-backflow component structure of a preferred embodiment of the present invention;

[0044] Figure 9 This is a cross-sectional schematic diagram of the automatic exhaust device in this utility model during exhaust.

[0045] In the diagram, 1' is the rain cover; 2' is the valve body; 3' is the protective sleeve; 4' is the valve cover; and 5' is the float.

[0046] 1. Rain cover; 2. Valve body; 201. First valve body; 202. Second valve body; 3. Base; 4. Valve cover; 5. Anti-backflow assembly; 51. Support frame; 511. Support ring; 512. Support rod; 513. Sleeve; 52. Vacuum valve disc; 53. O-ring; 54. Guide rod; 55. First sealing gasket; 56. Adjusting nut; 57. Spring; 58. Limiting nut; 6. Float; 7. Protective sleeve; 8. Through hole; 9. Center hole; 10. Fluid inlet; 11. Exhaust port; 12. Second sealing gasket; 13. Third sealing gasket; 14. Fourth sealing gasket. Detailed Implementation

[0047] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0048] Example: An automatic exhaust device, such as Figure 1 , 2As shown, the device includes a valve body 2, a valve cover 4, a protective sleeve 7, a float 6, a rain cover 1, and an anti-backflow assembly 5. The rain cover 1 is detachably installed on top of the valve body 2 to prevent rainwater, dust, and other impurities from entering the device, thus preventing corrosion or blockage of internal components. The valve body 2 includes a first valve body 201 and a second valve body 202 arranged vertically, detachably connected by the valve cover 4 to form the main outer shell of the device. The second valve body 202 has a fluid inlet 10 for communication with a pipeline network, forming a channel for fluid and gas from the pipeline network to enter the device. The valve cover 4 is installed between the first valve body 201 and the second valve body 202, and has a circular central hole 9 connecting the first and second valve bodies 201 and 202. The central hole 9 extends vertically through the valve cover 4 to allow fluid and gas to flow within the device. The protective sleeve 7 is located inside and communicates with the second valve body 202 to ensure that fluid within the second valve body 202 can enter the protective sleeve 7. The float 6 is located inside the protective sleeve 7 and can move up and down along the inner wall of the protective sleeve 7 under the action of fluid buoyancy. When the float 6 rises to a preset position, it can block the central hole 9 and block the flow between the first valve body 201 and the second valve body 202. The anti-backflow component 5 is disposed above the valve cover 4 and is used to prevent air backflow when a negative pressure is formed in the second valve body 202.

[0049] In the above technical solution, when the inlet pipe is under positive pressure, gas can quickly enter the first valve body 201 through the central hole 9, which runs vertically through the second valve body 202, and finally be discharged from the venting structure of the first valve body 201. This avoids problems such as pressure fluctuations and pump cavitation caused by gas accumulation in the pipeline network, ensuring the stable operation of the pipeline system. When the gas in the second valve body 202 is exhausted and the fluid is full, the float 6 rises along the inner wall of the protective sleeve 7 under the action of fluid buoyancy until it precisely seals the central hole 9, blocking the flow between the first valve body 201 and the second valve body 202, preventing fluid leakage. The entire process requires no manual intervention, realizing automated switching between venting and sealing, improving the reliability and intelligence of the device operation. In addition, the limiting effect of the protective sleeve 7 on the float 6 can prevent the float 6 from deviating due to water flow impact, ensuring that the float 6 always moves along the preset trajectory, further ensuring the accuracy of sealing the central hole 9 and reducing the risk of seal failure.

[0050] When changes in pipeline conditions cause negative pressure to form inside the second valve body 202, the anti-backflow component 5 can quickly block the passage for outside air to be drawn back into the second valve body 202 through the first valve body 201. If air is drawn back into the pipeline, it may cause abnormal noise from the water pump, cavitation, increased vibration, or even damage to the water pump equipment. The anti-backflow component 5 can effectively avoid such problems, ensure the safe operation of downstream equipment (such as water pumps) in the pipeline, and reduce equipment maintenance costs. At the same time, the anti-backflow component 5 enables the device to not only perform conventional venting functions but also adapt to negative pressure conditions in the pipeline, expanding the applicable scenarios of the device and improving its adaptability to complex pipeline environments.

[0051] Preferably, the rain cover 1 is located above the first valve body 201 and is detachably connected to the first valve body 201 by a screw or bolt. The detachable structure facilitates the periodic removal of the rain cover 1 for inspection, cleaning or maintenance of the device's interior without the need for complete disassembly of the device, reducing maintenance difficulty and time costs. At the same time, it allows for the replacement of rain covers 1 with different materials or structures according to the usage environment, improving the device's adaptability to different usage scenarios.

[0052] Preferably, the bottom of the second valve body 202 is integrally connected to a base 3, and the base 3 has a mounting hole for connecting to a pipeline network. The second valve body 202 is the fluid inlet of the device, and a circular fluid inlet 10 is provided at the center of its bottom for connecting to an external fluid pipeline, so that external fluids (such as tap water, industrial circulating water, etc.) and gases entrained in the fluid can enter the interior of the second valve body 202 through the fluid inlet 10.

[0053] Preferably, the protective sleeve 7 is vertically disposed within the second valve body 202, with a certain gap reserved between it and the inner wall of the second valve body 202. This gap is distributed around the circumference of the protective sleeve 7, forming an annular flow space for the flow of fluid and gas. Multiple through holes 8 are provided on the side wall of the protective sleeve 7, with each through hole 8 evenly spaced along the circumference of the protective sleeve 7, and all through holes 8 having the same shape and size. These evenly spaced through holes 8 penetrate the side wall of the protective sleeve 7, allowing direct communication between the internal space of the protective sleeve 7 and the internal space of the second valve body 202. This ensures that the fluid in the second valve body 202 can enter the interior of the protective sleeve 7 evenly from all sides, providing stable buoyancy support for the float 6. Furthermore, the evenly spaced distribution of the through holes 8 also prevents localized turbulence when the fluid enters the protective sleeve 7, reducing the impact on the float 6 and ensuring smooth movement of the float 6 along the inner wall of the protective sleeve 7.

[0054] like Figure 3-5 As shown, the valve cover 4 is horizontally positioned between the first valve body 201 and the second valve body 202, and is detachably fixed using bolts. Specifically, the lower end face of the first valve body 201, the valve cover 4, and the upper end face of the second valve body 202 are all provided with the same number of bolt holes. The valve body 2 adopts a segmented structure in which the first valve body 201 and the second valve body 202 are detachably connected by the valve cover 4, which facilitates the selection of suitable materials for different functional requirements during the manufacturing process, ensuring performance while controlling manufacturing costs. Furthermore, when internal components (such as the protective sleeve 7 and the float 6) are damaged or aged, the first valve body 201 and the second valve body 202 can be separated by removing the valve cover 4, allowing for direct replacement of the damaged component without removing the entire device from the pipeline network. This significantly reduces maintenance difficulty and downtime, minimizing the impact on the normal operation of the pipeline system.

[0055] To prevent fluid or gas from leaking from the gaps between the components, the present invention also provides sealing gaskets at the contact surfaces of each component.

[0056] like Figure 3-6 As shown, a second sealing gasket 12 is provided at the bottom of the valve cover 4, surrounding the central hole 9. The second sealing gasket 12 is made of elastic rubber, such as nitrile rubber or fluororubber, and its inner diameter is consistent with the diameter of the central hole 9. After assembly, the lower end face of the second sealing gasket 12 protrudes slightly from the bottom end face of the valve cover 4. When the float 6 rises to the blocking position under the action of fluid buoyancy, the upper end face of the float 6 is tightly pressed against the second sealing gasket 12. The elastic deformation of the second sealing gasket 12 fills the microscopic gap between the float 6 and the bottom of the valve cover 4, forming a sealing barrier for the central hole 9, preventing fluid from leaking from the mating point between the central hole 9 and the float 6 to the first valve body 201.

[0057] The upper end of the protective sleeve 7 is pressed against the valve cover 4 and the second valve body 202. A third sealing gasket 13 is provided between the valve cover 4, the second valve body 202, and the protective sleeve 7. Specifically, the upper end face of the protective sleeve 7 extends horizontally between the valve cover 4 and the second valve body 202. The third sealing gasket 13 is an annular elastic gasket, whose upper end face abuts against the bottom end face of the valve cover 4, and its lower end face abuts against both the upper end face of the protective sleeve 7 and the upper end face of the second valve body 202.

[0058] A fourth sealing gasket 14 is provided between the protective sleeve 7 and the second valve body 202, so that the top surface of the upper end of the protective sleeve 7 abuts against the third sealing gasket 13, and the bottom surface abuts against the fourth sealing gasket 14. Specifically, the inner wall of the top of the second valve body 202 is provided with an annular positioning platform, and the fourth sealing gasket 14 is placed on the annular positioning platform and is coaxially arranged with the protective sleeve 7. The lower end face of the protective sleeve 7 is supported on the fourth sealing gasket 14, and the preload force of the bolt connection is transmitted upward, so that the lower end face of the protective sleeve 7 abuts tightly against the fourth sealing gasket 14. At the same time, the upper end face of the protective sleeve 7 presses the third sealing gasket 13 upward, ultimately forming a longitudinal pressing structure.

[0059] In the above technical solution, during assembly, as the bolts between the valve cover 4, the first valve body 201, and the second valve body 202 are tightened, the bolt preload pushes the valve cover 4 downward to press the third sealing gasket 13, and the protective sleeve 7 downward to press the fourth sealing gasket 14, causing the third sealing gasket 13 and the fourth sealing gasket 14 to undergo elastic deformation. This ensures the assembly stability of the first valve body 201, the valve cover 4, and the second valve body 202, and also achieves all-around sealing of the central hole 9 and the component contact surfaces through the layered sealing structure, providing a double guarantee for the long-term stable operation of the device.

[0060] like Figure 3-9As shown, the first valve body 201 has an exhaust port 11 at its top. The anti-backflow assembly 5 includes a support frame 51, a guide rod 54, a vacuum valve disc 52, and a spring 57. The support frame 51 is installed inside the first valve body 201 to provide stable support. The guide rod 54 moves vertically through the support frame 51 to form a moving guide. The vacuum valve disc 52 is fixed to the upper end of the guide rod 54 to block the exhaust port 11 at the top of the first valve body 201. The spring 57 is sleeved on the guide rod 54 to provide a preload force to the vacuum valve disc 52 towards the exhaust port 11, so that the vacuum valve disc 52 has a closing tendency to fit against the exhaust port 11 under normal conditions. When positive pressure is generated inside the first valve body 201 due to exhaust, the gas pressure overcomes the preload force of the spring 57 and pushes the vacuum valve disc 52 upward, opening the exhaust port 11 to achieve exhaust. When negative pressure is generated inside the second valve body 202, the preload force of the spring 57 pushes the vacuum valve disc 52 downward to block the exhaust port 11 and prevent the outside air from being sucked back in.

[0061] Preferably, the anti-backflow assembly 5 further includes an adjusting nut 56. The upper end of the guide rod 54 passes through the vacuum valve disc 52 and is locked by the adjusting nut 56. Rotating the adjusting nut 56 can change the pre-compression of the spring 57. Specifically, the adjusting nut 56 is threaded to the upper outer surface of the guide rod 54. After the upper end of the guide rod 54 passes through the vacuum valve disc 52, tightening the adjusting nut 56 locks the vacuum valve disc 52 onto the guide rod 54, preventing the vacuum valve disc 52 from loosening or shifting. At the same time, a first sealing gasket 55 is provided between the adjusting nut 56 and the vacuum valve disc 52. The first sealing gasket 55 is an annular rubber gasket, the inner diameter of which is adapted to the outer diameter of the guide rod 54, and the outer diameter of which is adapted to the outer diameter of the adjusting nut 56. The clamping force of the adjusting nut 56 makes the first sealing gasket 55 tightly fit the upper surface of the vacuum valve disc 52, preventing gas from leaking from the connection gap between the guide rod 54 and the vacuum valve disc 52. In addition, rotating the adjusting nut 56 can finely adjust the up and down position of the vacuum valve disc 52, indirectly changing the pre-compression of the spring 57 to adapt to the sealing requirements under different negative pressure conditions.

[0062] In the above technical solution, due to differences in the pressure conditions and layout of the inlet pipes at various project sites, the vacuum valve disc 52 can be adjusted on-site using the adjusting nut 56 to facilitate normal opening, venting, and sealing. When the inlet pipe pressure is low, the adjusting nut 56 can be loosened appropriately to reduce the spring force of the spring 57, allowing the vacuum valve disc 52 to open and close properly. When the inlet pipe pressure is slightly higher, the adjusting nut 56 can be tightened appropriately to increase the spring force of the spring 57, ensuring the vacuum valve disc 52 can open and close properly.

[0063] Preferably, the anti-backflow assembly 5 further includes a fixing nut, with the lower end of the guide rod 54 threadedly connected to the fixing nut. The spring 57 is located between the support frame 51 and the fixing nut, with its upper end abutting against the support frame 51 and its lower end abutting against the fixing nut. The fixing nut is threaded to the lower outer surface of the guide rod 54. By rotating the fixing nut and moving it up and down along the guide rod 54, the initial compression of the spring 57 can be adjusted, thereby initially setting the preload of the spring 57 on the vacuum valve disc 52.

[0064] Preferably, the support frame 51 includes a support ring 511, a support rod 512, and a sleeve 513, which are integrated or welded together. The outer circumferential surface of the support ring 511 is tightly fitted to the inner wall of the first valve body 201 and is fixed around the inner wall of the first valve body 201 by welding or bolting, ensuring the overall stability of the support frame 51. The support rod 512 is connected between the support ring 511 and the sleeve 513 and is evenly distributed along the circumference of the support ring 511. The sleeve 513 is a cylindrical hollow part, coaxially located at the center of the support ring 511, and its inner diameter is adapted to the outer diameter of the guide rod 54. The sleeve 513 is fitted onto the guide rod 54, providing precise guidance for the vertical movement of the guide rod 54 and preventing the guide rod 54 from shifting, which would cause the vacuum valve disc 52 to misalign with the exhaust port 11.

[0065] Preferably, the guide rod 54 is vertically movably inserted into the sleeve 513 of the support frame 51, and can move up and down along the axis of the sleeve 513. The vacuum valve disc 52 is a circular disc, fixed to the upper end of the guide rod 54, and corresponds vertically to the exhaust port 11 at the top of the first valve body 201. The upper inner diameter of the exhaust port 11 gradually increases from bottom to top, forming a conical sealing surface. The lower end face of the vacuum valve disc 52 is a conical structure adapted to the conical sealing surface, so that when the two are in contact, a tight surface seal can be formed, improving the sealing performance of the negative pressure sealing.

[0066] Further preferably, to enhance the sealing effect, an O-ring 53 is provided between the vacuum valve disc 52 and the conical sealing surface of the exhaust port 11. The O-ring 53 is embedded in the conical sealing surface of the exhaust port 11. When the vacuum valve disc 52 is in contact with the conical sealing surface, the O-ring 53 is compressed and deformed, filling the microscopic gap between the vacuum valve disc 52 and the conical sealing surface, forming a secondary seal, and completely preventing air from being drawn back from the gap in the sealing surface.

[0067] Working process and principle: During the process of the water inlet pipeline system from empty pipe to water supply, air in the pipeline enters the device. Under the action of pressure, it pushes the vacuum valve disc 52, compresses the spring 57, and the vacuum valve disc 52 and guide rod 54 move upward as a whole, and the gas is discharged from the exhaust port 11. When the gas in the second valve body 202 is exhausted, water in the water inlet pipeline enters the second valve body 202. Under the action of buoyancy and water pressure, the float 6 contacts the second sealing gasket 12 at the valve cover 4 to form a seal, preventing water leakage in the pipeline. At this time, the pressure in the upper cavity of the valve cover 4 is the same as that of the outside atmosphere. Under the push of the spring 57 and the weight of the vacuum valve disc 52 and guide rod 54, the vacuum valve disc 52 contacts the exhaust port 11 and forms a seal through the O-ring 53.

[0068] When the water pump starts running, due to the low positive pressure of the inlet water or the excessive length of the pipeline, the pressure drop in the inlet water network during pump operation is higher than the positive pressure of the pump inlet when the pump is stopped. This causes a negative pressure to form at the pump inlet, and the water in the second valve body 202 will flow back from the fluid inlet 10 to the inlet water pipe. The float 6 will then detach from the second sealing gasket 12 at the valve cover 4 until it falls to the bottom of the protective sleeve 7. At this time, the device contacts the exhaust port 11 through the vacuum valve disc 52 and forms a seal through the O-ring 53, which can effectively prevent external gas from entering the inlet water network and ensure the water inlet conditions of the water pump.

[0069] The above are merely preferred embodiments of this utility model. The protection scope of this utility model is not limited to the above embodiments. All technical solutions falling within the scope of this utility model's concept are within its protection scope. It should be noted that for those skilled in the art, any improvements and modifications made without departing from the principle of this utility model should also be considered within its protection scope.

Claims

1. An automatic venting device, comprising a valve body, a valve cover, a protective sleeve, a float, and a rain cover, wherein the rain cover is located above the valve body, characterized in that: It also includes an anti-backflow component; The valve body includes a first valve body and a second valve body, and the second valve body is provided with a fluid inlet; The valve cover is installed between the first valve body and the second valve body, and the valve cover has a central hole that connects the first valve body and the second valve body. The protective sleeve is disposed within the second valve body and communicates with the second valve body. The float is located inside the protective sleeve and can rise under the action of fluid buoyancy to block the central hole. The anti-backflow component is located above the valve cover and is used to prevent air backflow when a negative pressure is formed in the second valve body.

2. The automatic exhaust device according to claim 1, characterized in that: The anti-backflow component includes: The support frame is installed inside the first valve body; The guide rod is vertically and movably inserted through the support frame; A vacuum valve disc, fixed to the upper end of the guide rod, is used to block the exhaust port at the top of the first valve body; A spring, sleeved on the guide rod, provides a preload force to the vacuum valve disc toward the exhaust port, so that the vacuum valve disc tends to close toward the exhaust port.

3. An automatic exhaust device according to claim 2, characterized in that: The anti-backflow assembly also includes an adjusting nut; The upper end of the guide rod passes through the vacuum valve disc and is locked by the adjusting nut. Rotating the adjusting nut can change the pre-compression of the spring.

4. An automatic exhaust device according to claim 3, characterized in that: A first sealing gasket is provided between the adjusting nut and the vacuum valve disc.

5. An automatic exhaust device according to claim 2, characterized in that: The anti-backflow assembly also includes a fixing nut; The lower end of the guide rod is threadedly connected to the fixing nut. The spring is located between the support frame and the fixing nut, with its upper end abutting against the support frame and its lower end abutting against the fixing nut.

6. An automatic exhaust device according to claim 2, characterized in that: The support frame includes a support ring, a support rod, and a sleeve. The support ring is fixed around the inner wall of the first valve body. The support rod is connected between the support ring and the sleeve. The sleeve is fitted onto the guide rod.

7. An automatic exhaust device according to claim 2, characterized in that: The upper inner diameter of the exhaust port gradually increases from bottom to top to form a conical sealing surface; The lower end face of the vacuum valve disc is adapted to the conical sealing surface so that a surface seal is formed when the vacuum valve disc is in contact with the exhaust port.

8. An automatic exhaust device according to claim 7, characterized in that: An O-ring is provided between the vacuum valve disc and the conical sealing surface.

9. An automatic exhaust device according to claim 1, characterized in that: The valve cover is detachably installed between the first valve body and the second valve body.

10. An automatic exhaust device according to claim 1, characterized in that: A second sealing gasket is provided at the bottom of the valve cover, and the second sealing gasket surrounds the center hole. The upper end of the protective sleeve abuts against the valve cover and the second valve body, and a third sealing gasket is provided between the valve cover, the second valve body, and the protective sleeve; A fourth sealing gasket is provided between the protective sleeve and the second valve body, so that the top surface of the upper end of the protective sleeve abuts against the third sealing gasket and the bottom surface abuts against the fourth sealing gasket.

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