Slowly-closed check valve

Abstract

The invention discloses a slow-closing check valve and relates to the technical field of valves, the slow-closing check valve comprises a valve body and an opening and closing mechanism, the valve body is provided with an inner cavity, the two ends of the inner cavity are open, and the inner cavity comprises a rotating cavity in the middle and two channels on the two sides; the opening and closing mechanism comprises a main valve clack and an auxiliary valve clack, the main valve clack is rotationally arranged above one side of the rotating cavity and opens or closes the channel in a rotating and swinging mode, a liquid passing opening is formed in the main valve clack, and the auxiliary valve clack is rotationally arranged above the liquid passing opening and opens or closes the liquid passing opening in a rotating and swinging mode; rotation between the auxiliary valve clack and the main valve clack has a damping effect. The valve has the advantages that the water hammer effect is effectively relieved, sequential closing of the main and auxiliary valve clacks is achieved, and the safety of a pipeline system is improved.

Description

Technical Field

[0001] This invention relates to the field of valve technology, and in particular to a slow-closing check valve. Background Technology

[0002] As a key component in fluid transport systems, the check valve's core function is to achieve unidirectional flow control through the weight of its circular valve disc and the pressure of the medium. Swing check valves employ an angled valve disc design, remaining open when the medium flows downstream and closing rapidly when it flows upstream. However, this traditional structure has a drawback: when the transport system experiences a sudden pump stoppage or a sharp drop in flow velocity, the valve disc may close instantaneously under the pressure of the medium or gravity. This sudden flow control can generate a severe water hammer effect within the pipeline. The pressure wave generated by the water hammer not only impacts the valve body structure, leading to seal failure and component deformation, but can also propagate along the pipeline, causing a chain reaction of damage, potentially resulting in pipeline rupture, pump damage, and other safety accidents. Summary of the Invention

[0003] The main objective of this invention is to propose a slow-closing check valve, which has the advantages of effectively mitigating water hammer, achieving sequential closure of the main and auxiliary valve discs, and improving the safety of the pipeline system.

[0004] To achieve the above objectives, the slow-closing check valve proposed in this invention includes: The valve body has an inner cavity with openings at both ends. The inner cavity includes a central rotating cavity and two channels on both sides. An opening and closing mechanism, comprising a main valve disc and a secondary valve disc, wherein the main valve disc is rotatably disposed above one side of the rotating chamber, and opens or closes the channel by rotating and swinging; the main valve disc has a liquid inlet, and the secondary valve disc is rotatably disposed above the liquid inlet, and opens or closes the liquid inlet by rotating and swinging. The rotation between the secondary valve disc and the primary valve disc has a damping effect. When the medium in the check valve is in a downstream state, both the primary valve disc and the secondary valve disc are in the open state. When the medium in the check valve is in a upstream state, the primary valve disc swings and closes the channel due to its own weight and the change in the direction of medium flow. After the primary valve disc closes, the secondary valve disc closes due to the pressure of the medium, so that the primary valve disc and the secondary valve disc close one after the other, avoiding sudden interruption of flow and reducing damage caused by water hammer effect.

[0005] In one embodiment, the liquid passage is located in the middle of the main valve disc.

[0006] In one embodiment, the opening and closing mechanism includes: Two fixing members are provided, which are located above one side of the rotating cavity, and the two fixing members are spaced apart to form a rotating position. A rotating shaft, which is rotatably mounted on the fixed member; A connecting frame connects the rotating shaft and the main valve disc, and the connecting frame is located on the side of the main valve disc closer to the rotating cavity.

[0007] In one embodiment, the connecting frame includes: A connecting plate, which is connected to the rotating shaft; A connecting ring is connected to the connecting plate, and the inner ring of the connecting ring makes way for the secondary valve disc so that the secondary valve disc can be smoothly closed or opened; Four connecting blocks are evenly spaced on the connecting ring, and the connecting blocks are connected to the main valve disc.

[0008] In one embodiment, the secondary valve disc includes a rotating shaft, and a damping cylinder is provided on the connecting block, with the rotating shaft rotatably disposed within the damping cylinder; or The rotating shaft is rotatably connected to the connecting block, and a torsion spring is provided between the rotating shaft and the connecting block.

[0009] In one embodiment, a recessed platform is provided around the liquid inlet, and a sealing gasket is provided on one side of the secondary valve disc. When the secondary valve disc is closed, the sealing gasket is located within the recessed platform.

[0010] In one embodiment, a damping structure is provided between the rotating shaft and the fixing member. The damping structure is used to apply a damping effect to the rotation of the rotating shaft when the main valve is closed more than halfway, so as to avoid strong impact of the main valve while ensuring the check speed.

[0011] In one embodiment, each of the two fixing members has a recessed groove on one side opposite to the other. The rotating shaft is rotatably disposed in the recessed groove. There is a gap between the edge of the rotating shaft and the inner wall of the recessed groove. The two ends of the rotating shaft have protrusions. The inner wall of the recessed groove has a damping element. When the main valve is closed more than halfway, the protrusions contact the damping element to produce a damping effect on the rotating shaft.

[0012] In one embodiment, the main valve disc includes a valve disc body and a sealing ring, the sealing ring being disposed around the edge of the valve disc body, and an anti-collision ring being provided in the channel, the anti-collision ring being sealed with the sealing ring.

[0013] In one embodiment, the edge of the sealing ring is provided with a guide slope, and the anti-collision ring is provided with a slope corresponding to the guide slope.

[0014] As can be seen from the above, the slow-closing check valve and its opening and closing mechanism provided in this application, by setting a main and auxiliary valve disc structure with a damping effect, effectively avoids the sudden interruption of the medium flow under the sequential action of the main valve disc closing first and then the auxiliary valve disc closing, and significantly reduces the impact caused by the water hammer effect. It has the advantages of simple structure, convenient maintenance, and safety and reliability. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0016] Figure 1 A three-dimensional structural schematic diagram of an embodiment of the slow-closing check valve provided by the present invention; Figure 2 A cross-sectional diagram showing the opening of the check valve; Figure 3 A cross-sectional view showing the closure of the check valve; Figure 4 This is an explosion diagram of the opening and closing mechanism.

[0017] Explanation of icon numbers: 1000. Slow-closing check valve; 1. Valve body; 11. Rotating chamber; 12. Channel; 2. Opening and closing mechanism; 21. Main valve disc; 211. Sealing ring; 212. Liquid passage port; 213. Recessed platform; 22. Secondary valve disc; 221. Rotating shaft; 222. Torsion spring; 23. Fixing component; 231. Recessed groove; 232. Damping component; 24. Rotating shaft; 241. Protrusion; 25. Connecting frame; 251. Connecting plate; 252. Connecting ring; 253. Connecting block; 3. Anti-collision ring.

[0018] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0019] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0020] It should be noted that if the embodiments of the present invention involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicators will also change accordingly.

[0021] Furthermore, if the embodiments of this invention involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. If the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this invention.

[0022] Please see Figures 1 to 4 This application proposes a slow-closing check valve 1000, comprising a valve body 1 and an opening / closing mechanism 2. The valve body 1 has an inner cavity with openings at both ends, including a central rotating cavity 11 and two side channels 12. The opening / closing mechanism 2 includes a main valve disc 21 and a secondary valve disc 22. The main valve disc 21 is rotatably disposed above one side of the rotating cavity 11, opening or closing the channel 12 by rotational swing. The main valve disc 21 has a liquid passage port 212, and the secondary valve disc 22 is rotatably disposed above the liquid passage port 212, opening or closing the liquid passage port 212 by rotational swing. The rotation between the secondary valve disc 22 and the main valve disc 21 has a damping effect. When the medium in the check valve is in a downstream state, both the main valve disc 21 and the secondary valve disc 22 are in the open state. When the medium in the check valve is in a reverse state, the main valve disc 21 swings and closes the channel 12 due to its own weight and the change in the direction of medium flow. After the main valve disc 21 closes, the secondary valve disc 22 is closed due to the pressure of the medium, so that the main valve disc 21 and the secondary valve disc 22 close one after the other, avoiding sudden interruption of flow and reducing damage caused by water hammer effect.

[0023] Specifically, the valve body 1 can be made of cast iron, stainless steel, or other corrosion-resistant materials, and the shape of the inner cavity can be designed as circular, square, or other geometric shapes according to actual needs. The dimensions of the rotating chamber 11 should ensure that the main valve disc 21 can rotate and swing freely, and the diameters of the two channels 12 can be adjusted according to the medium flow rate. The main valve disc 21 and the auxiliary valve disc 22 can be made of metal or composite materials, and their weight and dimensions need to be optimized according to the medium pressure. The shape and size of the liquid passage 212 can be adjusted according to the medium flow rate and flow rate to ensure that the auxiliary valve disc 22 can effectively control the opening and closing of the liquid passage 212. The damping effect can be achieved by setting a damper, torsion spring 222, or other buffer device between the auxiliary valve disc 22 and the main valve disc 21 to control the closing speed of the auxiliary valve disc 22.

[0024] Therefore, this technical solution, by setting up a main valve disc 21 and a secondary valve disc 22 and having them close sequentially, effectively mitigates the water hammer effect caused by the rapid closure of traditional check valves. Specifically, the main valve disc 21 first closes the channel 12, followed by the secondary valve disc 22 slowly closing the liquid outlet 212, avoiding a sudden interruption of media flow and thus reducing the impact on the pipeline and valve. Compared with existing technologies, this solution significantly reduces the risk of damage caused by water hammer while ensuring the check function, thereby improving the valve's service life and safety.

[0025] Please see Figures 2 to 4 Furthermore, this application also proposes that the liquid outlet 212 is located in the middle of the main valve disc 21.

[0026] Specifically, the liquid passage 212 is positioned in the center of the main valve disc 21, allowing the medium to flow evenly through it. In a preferred embodiment, the liquid passage 212 can be circular, elliptical, or polygonal, with its dimensions determined by the size of the main valve disc 21 and the required medium flow rate. For example, the diameter of the liquid passage 212 can be 1 / 3 to 1 / 2 of the width of the main valve disc 21 to ensure sufficient flow area. Furthermore, the edges of the liquid passage 212 can be chamfered or rounded to reduce resistance during medium flow. In addition, the centrally positioned liquid passage 212 helps ensure even force distribution on the secondary valve disc 22 when closed, preventing poor sealing or increased wear due to offset. Therefore, this technical solution optimizes the medium flow path by positioning the liquid passage 212 in the center of the main valve disc 21, resulting in smoother linkage between the main valve disc 21 and the secondary valve disc 22.

[0027] Please see Figures 2 to 4Furthermore, this application also proposes that the opening and closing mechanism 2 of the slow-closing check valve 1000 includes two fixed members 23, a rotating shaft 24, and a connecting frame 25. The two fixed members 23 are located above one side of the rotating cavity 11, and the two fixed members 23 are spaced apart to form a rotating position. The rotating shaft 24 is rotatably mounted on the fixed members 23. The connecting frame 25 connects the rotating shaft 24 and the main valve disc 21, and the connecting frame 25 is located on the side of the main valve disc 21 near the rotating cavity 11.

[0028] The fixing component 23 can be made of metal casting or high-strength engineering plastic, and its spacing needs to be precisely designed according to the swing amplitude of the main valve disc 21. The rotating shaft 24 can be made of stainless steel, and its two ends are rotatably connected to the fixing component 23 through bearings or bushings. The connecting frame 25 can be a one-piece molded metal frame structure, and its connection with the rotating shaft 24 can be welding, bolting, or snap-fitting, and its connection with the main valve disc 21 can be threaded or riveted. As a preferred embodiment, a buffer pad can be provided between the connecting frame 25 and the main valve disc 21 to reduce the impact during closure.

[0029] Specifically, this technical solution utilizes the cooperation of the fixing component 23 and the rotating shaft 24 to enable the main valve disc 21 to rotate and oscillate stably around the rotating shaft 24. The connecting frame 25 transmits the rotational motion of the rotating shaft 24 to the main valve disc 21, ensuring that the opening and closing action of the main valve disc 21 is synchronized with the rotating shaft 24. The connecting frame 25 is located on the side of the main valve disc 21 closest to the rotating cavity 11. This arrangement optimizes the lever arm length and reduces the torque required to drive the main valve disc 21 to oscillate. Therefore, this structure ensures reliable valve opening and closing while effectively controlling the oscillation speed of the main valve disc 21, avoiding the water hammer effect caused by rapid closure.

[0030] Please see Figures 2 to 4 Furthermore, this application also proposes that the connecting frame 25 includes a connecting plate 251, a connecting ring 252, and four connecting blocks 253. The connecting plate 251 is connected to the rotating shaft 24, the connecting ring 252 is connected to the connecting plate 251, the inner ring of the connecting ring 252 makes way for the secondary valve disc 22 so that the secondary valve disc 22 can be smoothly closed or opened, and the four connecting blocks 253 are evenly spaced on the connecting ring 252 and connected to the main valve disc 21.

[0031] Specifically, the connecting plate 251 can be made of sheet metal by stamping or casting, and its thickness is designed to be 3-8mm according to the stress requirements. The connecting ring 252 is preferably an annular steel plate, with an inner diameter 5-10mm larger than the diameter of the secondary valve disc 22 to ensure sufficient clearance. The connecting blocks 253 can be fixed to the connecting ring 252 by welding or bolting, preferably four in number and evenly distributed at 90°. The connection between each connecting block 253 and the main valve disc 21 can be hinged or rigid. As a preferred embodiment, a buffer gasket can be provided between the connecting block 253 and the main valve disc 21 to reduce impact vibration.

[0032] Therefore, this technical solution, by optimizing the structure of the connecting frame 25, achieves reliable transmission between the main valve disc 21 and the rotating shaft 24, while providing ample movement space for the auxiliary valve disc 22. The inner ring design of the connecting ring 252 avoids interference with the movement of the auxiliary valve disc 22, and the evenly distributed connecting blocks 253 ensure balanced force on the main valve disc 21. Compared with existing technologies, this structure effectively reduces frictional losses of moving parts and improves the service life of the valve while ensuring the valve's opening and closing function. Specifically, the modular design of the connecting frame 25 facilitates processing and assembly, and the symmetrical arrangement of the four connecting blocks 253 keeps the main valve disc 21 stable during closing, avoiding sealing failure caused by uneven force.

[0033] Please see Figures 2 to 4 Furthermore, this application also proposes that the secondary valve disc 22 includes a rotating shaft 221, a damping cylinder is provided on the connecting block 253, and the rotating shaft 221 is rotatably disposed on the damping cylinder; or the rotating shaft 221 is rotatably connected to the connecting block 253, and a torsion spring 222 is provided between the rotating shaft 221 and the connecting block 253.

[0034] Specifically, the damping cylinder can employ a hydraulic damping structure, filled with a viscous fluid, to achieve rotational damping through fluid resistance. Alternatively, it can utilize a magnetorheological damping structure, adjusting the damping force by changing the magnetic field strength. The torsion spring 222 can be made of stainless steel, with different damping effects achieved through preload adjustment. The connection between the rotating shaft 221 and the connecting block 253 can employ a bearing structure to ensure smooth rotation. A wear-resistant coating can be applied to the inner wall of the damping cylinder to extend its service life.

[0035] Therefore, this technical solution uses a damping cylinder or torsion spring 222 structure to provide a buffering effect during the closing process of the secondary valve disc 22. When the main valve disc 21 closes, the medium pressure pushes the secondary valve disc 22 to close, and the damping structure can slow down the closing speed, preventing the liquid passage 212 from being suddenly cut off. Compared with the prior art, this solution effectively alleviates the water hammer effect, reduces pressure fluctuations in the pipeline system, and is simple, reliable, and easy to maintain. In specific implementation, the damping cylinder or torsion spring 222 solution can be selected according to different operating conditions, showing good adaptability.

[0036] Please see Figures 2 to 4 Furthermore, this application also proposes to provide a recessed platform 213 around the liquid outlet 212 and to provide a sealing gasket on one side of the secondary valve disc 22, wherein the sealing gasket is located in the recessed platform 213 when the secondary valve disc 22 is in the closed state.

[0037] Specifically, the recessed platform 213 is an annular groove structure machined around the edge of the liquid inlet 212, and its depth and width match the dimensions of the sealing gasket. The sealing gasket can be made of elastic sealing materials such as rubber or polytetrafluoroethylene, and is installed on the sealing surface of the secondary valve disc 22 by adhesive bonding or mechanical fixing. As a preferred embodiment, the cross-sectional shape of the recessed platform 213 can be designed as trapezoidal or arc-shaped to better accommodate the sealing gasket and form multiple sealing lines. In addition, the sealing gasket can adopt a hollow structure or have an internal reinforcing skeleton to balance elastic deformation capacity and structural strength.

[0038] The working principle of this technical solution is as follows: when the backflow of the medium causes the main valve disc 21 to close, the secondary valve disc 22 slowly closes under the pressure of the medium. During the closing process, the sealing gasket first contacts the edge of the recessed platform 213. As the secondary valve disc 22 continues to press down, the sealing gasket undergoes elastic deformation and is completely embedded in the recessed platform 213. This forms a three-stage sealing effect: the first stage achieves radial sealing through the tight contact between the sealing gasket and the side wall of the recessed platform 213; the second stage achieves axial sealing through the pressing of the bottom of the sealing gasket against the bottom surface of the recessed platform 213; and the third stage maintains continuous clamping force through the rebound force generated by the deformation of the sealing gasket. Compared with planar contact seals, this structure can effectively compensate for machining errors, achieve reliable sealing under low-pressure conditions, and reduce the requirements for valve disc machining accuracy. By controlling the depth of the recessed platform 213, the sealing contact pressure can also be precisely adjusted to avoid premature aging of the sealing material due to overpressure.

[0039] Please see Figures 2 to 4 Furthermore, this application also proposes that a damping structure is provided between the rotating shaft 24 and the fixing member 23. The damping structure is used to apply a damping effect to the rotation of the rotating shaft 24 when the main valve disc 21 is closed more than halfway, so as to avoid strong impact of the main valve disc 21 while ensuring the check speed.

[0040] The specific implementation methods of the damping structure include, but are not limited to, the following: Each of the two fixed members 23 has a recessed groove 231 on one side opposite to the other. The rotating shaft 24 is rotatably mounted in the recessed groove 231. There is a gap between the edge of the rotating shaft 24 and the inner wall of the recessed groove 231. Protrusions 241 are provided at both ends of the rotating shaft 24. A damping element 232 is provided on the inner wall of the recessed groove 231. When the main valve disc 21 is closed more than halfway, the protrusions 241 contact the damping element 232 to produce a damping effect on the rotating shaft 24. The damping element 232 can be made of elastic materials such as rubber or polyurethane, absorbing impact energy through material deformation. In addition, the damping structure can also employ active control methods such as hydraulic dampers or magnetorheological dampers, adjusting the damping force in real time according to the closing angle of the main valve disc 21.

[0041] This technical solution introduces a damping effect during the latter half of the main valve disc 21's closure, ensuring unimpeded closure and a rapid check valve response. As the valve approaches full closure, the damping structure activates, slowing the closing speed and effectively reducing the impact force between the main valve disc 21 and the valve body 1. Compared to existing technologies that rely solely on gravity or spring force for rapid closure, this solution significantly reduces the impact of water hammer while ensuring timely valve closure, extending valve lifespan and improving system safety. Specifically, the damping structure's intervention timing is precisely designed, activating only after the main valve disc 21's closing angle exceeds 50%, avoiding premature damping that could affect the closing speed while ensuring sufficient buffering during critical phases.

[0042] Please see Figures 2 to 4 Furthermore, this application also proposes that each of the two fixing members 23 has a recessed groove 231 on one side opposite to the other, the rotating shaft 24 is rotatably disposed in the recessed groove 231, there is a gap between the edge of the rotating shaft 24 and the inner wall of the recessed groove 231, the two ends of the rotating shaft 24 have protrusions 241, and the inner wall of the recessed groove 231 has a damping member 232. When the main valve disc 21 is closed more than halfway, the protrusions 241 contact the damping member 232 to produce a damping effect on the rotating shaft 24.

[0043] The recessed groove 231 is a recessed structure located inside the fixing member 23, used to accommodate the rotating shaft 24 and restrict its radial displacement. The gap between the edge of the rotating shaft 24 and the inner wall of the recessed groove 231 allows the rotating shaft 24 to rotate freely while avoiding direct friction. The protrusion 241 is a protruding structure extending outward from the end of the rotating shaft 24, and its shape can be hemispherical, wedge-shaped, or other shapes suitable for contacting the damping member 232. The damping member 232 can be made of elastic materials such as rubber or polyurethane, absorbing impact energy through deformation. As a preferred embodiment, the damping member 232 can be designed as an arc-shaped sheet structure to match the movement trajectory of the protrusion 241.

[0044] This technical solution provides a buffering effect during the later stages of main valve disc 21 closure by incorporating a damping structure between the rotating shaft 24 and the fixed component 23. Specifically, when the closing angle of the main valve disc 21 exceeds 50%, the protrusion 241 on the rotating shaft 24 begins to contact the damping component 232. As the closing angle increases, the contact pressure gradually increases, thus creating a progressive damping effect. This ensures both the valve's rapid response in the initial stage of media backflow and effectively reduces the impact velocity at the end of closure. Compared with existing technologies, this solution, through optimized mechanical structure design, significantly reduces the impact force during valve disc closure without affecting the check valve function, thereby mitigating the damage caused by water hammer.

[0045] Please see Figures 2 to 4Furthermore, this application also proposes that the main valve disc 21 of the slow-closing check valve 1000 includes a valve disc body and a sealing ring 211. The sealing ring 211 is arranged around the edge of the valve disc body, and an anti-collision ring 3 is provided in the channel 12, which seals with the sealing ring 211. The edge of the sealing ring 211 is provided with a guide slope, and the anti-collision ring 3 is provided with a slope corresponding to the guide slope.

[0046] Specifically, the sealing ring 211 can be made of elastic materials such as rubber or polytetrafluoroethylene, and is fixed to the edge of the valve disc body by vulcanization or mechanical pressing. The anti-collision ring 3 is preferably made of metal and is fixed to the inner wall of the channel 12 by threaded connection or welding. The inclination angle between the guide bevel and the bevel of the anti-collision ring 3 is recommended to be in the range of 15-45 degrees, which can achieve progressive contact sealing. As a preferred embodiment, the sealing ring 211 can be designed with a V-shaped cross section, and its lip forms a line contact seal with the bevel of the anti-collision ring 3. In addition, the bevel of the anti-collision ring 3 can be provided with a wear-resistant coating, such as a tungsten carbide coating, to extend its service life.

[0047] Therefore, this technical solution achieves progressive contact during the closing of the main valve disc 21 through the coordinated design of the guide ramps and ramps, effectively buffering the impact force between the valve disc and the valve body 1. When the medium flows in reverse, the main valve disc 21 begins to close under gravity. The guide ramp of the sealing ring 211 initially makes slight contact with the ramp of the anti-collision ring 3. As the closing stroke increases, the contact area gradually increases until a complete seal is achieved. Compared with the planar contact method, this structure can significantly reduce the impact noise at the moment of closing, while improving the sealing reliability through the self-centering effect of the ramps. The angle design of the guide ramps can also guide the medium flow and reduce the scouring damage to the sealing surface caused by turbulence.

[0048] Please see Figures 2 to 4 Furthermore, this application proposes that the edge of the sealing ring 211 be provided with a guide slope, and the anti-collision ring 3 be provided with a slope that matches the guide slope. This technical solution achieves progressive contact during the closing process of the main valve disc 21 by setting mutually cooperating guide slopes and the slope of the anti-collision ring 3. When the main valve disc 21 swings towards the closed position, the guide slope of the sealing ring 211 first contacts the slope of the anti-collision ring 3. As the valve disc continues to move, the contact area gradually increases until a complete seal is achieved. This design effectively avoids the instantaneous impact generated by traditional planar contact, and decomposes the closing impact force into axial and radial components through the guiding effect of the slope, significantly reducing the impact noise and wear between the valve disc and the valve seat.

[0049] The above description is merely an exemplary embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural transformations made using the contents of the present invention specification and drawings under the technical concept of the present invention, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present invention.

Claims

1. A slow-closing check valve, characterized in that, The slow-closing check valve includes: The valve body has an inner cavity with openings at both ends. The inner cavity includes a central rotating cavity and two channels on both sides. An opening and closing mechanism, comprising a main valve disc and a secondary valve disc, wherein the main valve disc is rotatably disposed above one side of the rotating chamber, and opens or closes the channel by rotating and swinging; the main valve disc has a liquid inlet, and the secondary valve disc is rotatably disposed above the liquid inlet, and opens or closes the liquid inlet by rotating and swinging. The rotation between the secondary valve disc and the primary valve disc has a damping effect. When the medium in the check valve is in a downstream state, both the primary valve disc and the secondary valve disc are in the open state. When the medium in the check valve is in a upstream state, the primary valve disc swings and closes the channel due to its own weight and the change in the direction of medium flow. After the primary valve disc closes, the secondary valve disc closes due to the pressure of the medium, so that the primary valve disc and the secondary valve disc close one after the other, avoiding sudden interruption of flow and reducing damage caused by water hammer effect.

2. The slow-closing check valve as described in claim 1, characterized in that, The liquid inlet is located in the middle of the main valve disc.

3. The slow-closing check valve as described in claim 1, characterized in that, The opening and closing mechanism includes: Two fixing members are provided, which are located above one side of the rotating cavity, and the two fixing members are spaced apart to form a rotating position. A rotating shaft, which is rotatably mounted on the fixed member; A connecting frame connects the rotating shaft and the main valve disc, and the connecting frame is located on the side of the main valve disc closer to the rotating cavity.

4. The slow-closing check valve as described in claim 3, characterized in that, The connecting frame includes: A connecting plate, which is connected to the rotating shaft; A connecting ring is connected to the connecting plate, and the inner ring of the connecting ring makes way for the secondary valve disc so that the secondary valve disc can be smoothly closed or opened; Four connecting blocks are evenly spaced on the connecting ring, and the connecting blocks are connected to the main valve disc.

5. The slow-closing check valve as described in claim 4, characterized in that, The secondary valve disc includes a rotating shaft, and a damping cylinder is provided on the connecting block; the rotating shaft is rotatably disposed within the damping cylinder; or The rotating shaft is rotatably connected to the connecting block, and a torsion spring is provided between the rotating shaft and the connecting block.

6. The slow-closing check valve as described in claim 5, characterized in that, A recessed platform is provided around the liquid inlet, and a sealing gasket is provided on one side of the secondary valve disc. When the secondary valve disc is closed, the sealing gasket is located inside the recessed platform.

7. The slow-closing check valve as described in claim 3, characterized in that, A damping structure is provided between the rotating shaft and the fixing member. The damping structure is used to apply a damping effect to the rotation of the rotating shaft when the main valve is closed more than halfway, so as to avoid strong impact on the main valve while ensuring the check speed.

8. The slow-closing check valve as described in claim 7, characterized in that, Both of the aforementioned fixing members have a recessed groove on their opposite sides. The rotating shaft is rotatably mounted in the recessed groove. There is a gap between the edge of the rotating shaft and the inner wall of the recessed groove. The two ends of the rotating shaft have protrusions. The inner wall of the recessed groove has a damping element. When the main valve is closed more than halfway, the protrusions contact the damping element to produce a damping effect on the rotating shaft.

9. The slow-closing check valve as described in claim 1, characterized in that, The main valve disc includes a valve disc body and a sealing ring. The sealing ring is arranged around the edge of the valve disc body. An anti-collision ring is provided in the channel, and the anti-collision ring seals with the sealing ring.

10. The slow-closing check valve as described in claim 9, characterized in that, The edge of the sealing ring is provided with a guide slope, and the anti-collision ring is provided with a slope corresponding to the guide slope.

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