Axial-flow type check valve for municipal pipeline

Abstract

The invention discloses an axial flow type check valve for municipal pipelines, and relates to the technical field of check valves, the axial flow type check valve comprises a liquid inlet pipe and a liquid outlet pipe, a valve body shell is fixedly arranged between the liquid inlet pipe and the liquid outlet pipe, a limiting shell is arranged on the inner side of the valve body shell, and the inner end of the liquid outlet pipe is fixedly connected with the limiting shell through a flow guide fixing block; a valve rod is arranged in the limiting shell in a sliding mode, a valve clack is fixedly arranged at the outer end of the valve rod, an attaching sealing ring is fixedly arranged at the inner end of the liquid inlet pipe, a first spring is arranged on the portion, located in the limiting shell, of the outer side of the valve rod, a limiting part is arranged on the valve rod, and a guide groove matched with the limiting part is formed in the inner side of the limiting shell. Municipal water flowing through the flow guide fixing block is guided, the limiting shell is also fixed, the valve clack, the valve rod, the first spring and the attached sealing ring are matched to control opening and closing of the valve body, and the guide groove and the limiting part are matched to achieve the effect of preventing the valve clack and the valve rod from rotating.

Description

Technical Field

[0001] The invention relates to the technical field of check valves, in particular to an axial flow check valve for municipal pipelines. Background Art

[0002] Municipal axial-flow check valves are automatic control devices widely used in municipal water supply, drainage, sewage treatment, and other fluid piping systems. Their primary function is to prevent fluid backflow, ensure unidirectional flow, and protect pipes and equipment from damage caused by backflow. Axial-flow check valves utilize an axial-flow structure, resulting in lower fluid resistance and improved flow capacity compared to traditional butterfly valves and ball valves.

[0003] The operating principle of an axial flow check valve is simple and highly effective. It features a disc positioned perpendicular to the valve seat, which automatically opens and closes based on the pressure and gravity of the fluid. When the fluid flows in the intended direction, the water pushes the disc open, allowing water to flow through. When the water flows in the opposite direction, the fluid pressure decreases, and the disc closes under its own weight, preventing backflow. Axial flow check valves are widely used in urban water supply, drainage systems, sewage treatment plants, fire protection systems, and industrial water treatment. In particular, in high-pressure, high-flow piping systems, axial flow check valves effectively prevent backflow, protecting pumping stations, pipe networks, and other facilities.

[0004] The invention patent with authorization announcement number CN104847932B discloses an axial flow check valve. This invention achieves absolute locking between the bushing, valve body and valve sleeve by adopting a series of connection methods such as anti-rotation pins, anti-rotation rings, and anti-return gaskets between the bushing, valve body and valve sleeve, thereby preventing relative rotation between the bushing and the valve body.

[0005] Although the above device solves the problem of relative rotation between the valve body and the valve sleeve, the device cannot delay the speed of opening or closing the valve body, and the resulting water hammer effect is not alleviated. Moreover, uniformly and slowly opening or closing the valve body can play a certain protective role on the valve disc, avoid damage to the sealing surface, and effectively extend the service life of the device. Therefore, there is a need for an axial flow check valve that can prevent the valve disc and valve stem from rotating and can be opened or closed slowly. Summary of the Invention

[0006] The object of the present invention is to provide an axial flow check valve for municipal pipelines to solve the problems raised in the above background technology.

[0007] To achieve the above object, the present invention provides the following technical solutions: An axial flow check valve for municipal pipelines, comprising a liquid inlet pipe and a liquid outlet pipe, a valve body shell fixedly disposed between the liquid inlet pipe and the liquid outlet pipe, a limit housing disposed inside the valve body shell, an inner end portion of the liquid outlet pipe being fixedly connected to the limit housing via a flow guide fixing block, a valve stem slidably disposed within the limit housing, a valve disc fixedly disposed at the outer end portion of the valve stem, a fitting sealing ring fixedly disposed at the inner end portion of the liquid inlet pipe, and the fitting sealing ring and the valve disc disposed correspondingly, a first spring disposed on the outer side of the valve stem within the limit housing, a limit portion disposed on the valve stem, and a guide groove cooperating with the limit portion disposed inside the limit housing; A pressure dividing device is provided above the valve body shell, the liquid inlet pipe is connected to the pressure dividing device through a first connecting pipe, and the liquid outlet pipe is connected to the pressure dividing device through a second connecting pipe; A first cavity space is provided on the inner side of the limit shell, and a crossbeam is fixedly provided on the inner side of the first cavity space and the inner wall of the limit shell. A bevel gear transmission mechanism is provided on one side of the crossbeam through a rotating shaft, and a limit fixing block is fixedly provided on one side of the bevel gear transmission mechanism. A spur rack is provided between the bevel gear transmission mechanism and the limit fixing block, and the spur rack is meshed with one of the gears in the bevel gear transmission mechanism. An inner rack is provided on the valve stem, and the inner rack is meshed with another gear in the bevel gear transmission mechanism. The spur rack passes through the limit shell and the valve body shell and is connected to the pressure dividing device.

[0008] As a further solution of the present invention: a sealing housing is fixedly provided between the valve body shell and the limit housing and located outside the spur rack.

[0009] As a further solution of the present invention: the pressure dividing device includes a second outer shell, a second piston is slidably arranged on the inside of the second outer shell, and the outer end of the straight rack is fixedly connected to the lower end surface of the second piston, a third piston is arranged on the inside of the second outer shell and above the second piston, a third cavity space is formed between the second piston and the third piston, a liquid passage is opened in the middle of the third piston and cooperates with the first connecting pipe and the second connecting pipe, a third spring is arranged on the inside of the second outer shell above the third piston, and a vent hole is opened on the second outer shell.

[0010] As a further solution of the present invention: the third cavity space is filled with air.

[0011] As a further solution of the present invention: a second boss is fixedly provided on the top of the second outer shell.

[0012] As a further solution of the present invention: a buffer device is provided on one side of the limit shell, and the buffer device includes a first outer shell, the inner end portion of the first outer shell is fixedly connected to the limit shell, an inner shell is fixedly provided on the inside of the first outer shell, a second cavity space is formed between the first outer shell and the inner shell, a number of flow holes are evenly opened on the inner shell, a moving rod is slidingly provided on the inside of the first outer shell, a first piston is fixedly provided on the inner end of the moving rod, and a second spring is provided on one side of the moving rod on the inner side of the inner shell.

[0013] As a further solution of the present invention: the outer diameter of the first piston is the same as the inner diameter of the inner housing.

[0014] As a further solution of the present invention: the outer end of the moving rod is provided with an inner groove that cooperates with the valve stem.

[0015] As a further solution of the present invention, both sides of the first piston and the second cavity are filled with oil.

[0016] As a further solution of the present invention: a first boss is fixedly provided on the inner side of the second spring at the bottom of the first outer shell.

[0017] Compared with the prior art, the present invention has the following beneficial effects: The municipal water flowing through is diverted by the diversion fixing block, and the limit housing is also fixed. The valve disc, valve stem, first spring and fitting sealing ring cooperate to control the opening and closing of the valve body. The guide groove and the limit part cooperate to prevent the valve disc and valve stem from rotating. The cooperation of the moving rod, the first piston and the second spring provides resistance when the valve stem is opened. The moving rod and the first piston move toward the side of the first boss. The first piston is resisted by the second spring. At the same time, the oil on the side of the first boss is fed into the second cavity space through a plurality of flow holes. Then, the oil in the second cavity space is fed into the space on the side of the moving rod through a plurality of flow holes, so that the valve stem drives the valve disc to open slowly, reducing the influence of the negative water hammer effect. The first boss serves to limit the first piston and prevent the second spring from being over-compressed. The valve stem and the moving rod are slidably connected. The buffer device does not affect the valve stem reset speed (the reset in the buffer device relies only on the elastic force of the second spring, so the reset time is longer), preventing the valve disc and valve stem from not being able to close in time, thereby improving the practicality of the device. The displacement of the valve stem drives the movement of the spur rack, causing the second piston to displace, which is then transmitted to the third piston through the air in the third chamber (the principle that air is compressible and expandable can also slow down the movement speed of the third piston). The liquid channel serves as a bridge to connect the first connecting pipe and the second connecting pipe, reducing the pressure exerted by the municipal water in the liquid inlet pipe on the valve disc, slowing down the speed of opening or closing of the valve disc, and playing a certain protective role on the entire valve body. The second boss acts as a limiter and also prevents the third spring from being over-compressed. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of the three-dimensional structure of the present invention.

[0019] Figure 2 It is a schematic diagram of the main structure of the present invention.

[0020] Figure 3 It is a schematic diagram of the top structure of the present invention.

[0021] Figure 4 For the present invention Figure 2 Schematic diagram of the cross-sectional structure at AA in the middle.

[0022] Figure 5 For the present invention Figure 3 Schematic diagram of the cross-sectional structure at BB in the middle.

[0023] Figure 6 For the present invention Figure 5 Schematic diagram of the local enlarged structure at point D in the middle.

[0024] Figure 7 For the present invention Figure 3 Schematic diagram of the cross-sectional structure at CC in the middle.

[0025] Figure 8 It is a schematic diagram of the partial cross-sectional structure of the buffer device in the present invention.

[0026] Figure 9 It is a schematic diagram of the partial cross-sectional structure of the voltage divider device in the present invention.

[0027] Figure 10 It is a schematic diagram of a local three-dimensional structure of the present invention.

[0028] Figure 11 It is another partial three-dimensional structural schematic diagram of the present invention.

[0029] Figure 12 This is another partial three-dimensional structural schematic diagram of the present invention.

[0030] Figure numerals: 1. Liquid inlet pipe; 2. Liquid outlet pipe; 3. Valve body shell; 4. Valve disc; 41. Fitting sealing ring; 5. Valve stem; 51. Inner rack; 6. Limiting shell; 7. First spring; 8. First cavity space; 9. Guide fixing block; 10. Guide groove; 11. Limiting part; 12. Crossbeam; 13. Bevel gear transmission mechanism; 14. Limiting fixing block; 15. Straight rack; 16. Sealing shell; 17. Buffer device; 171. First outer shell; 172. Inner shell body; 173, second cavity space; 174, flow hole; 175, first boss; 176, moving rod; 177, first piston; 178, second spring; 179, inner groove; 18, pressure dividing device; 181, second outer shell; 182, second piston; 183, third cavity space; 184, third piston; 185, liquid passage; 186, third spring; 187, second boss; 188, vent; 19, first connecting pipe; 20, second connecting pipe. DETAILED DESCRIPTION

[0031] The following embodiments will be described in detail with reference to the accompanying drawings. Similar or identical parts are denoted by the same reference numerals in the drawings or description. In actual applications, the shape, thickness, or height of each component may be enlarged or reduced. The various embodiments listed in the present invention are intended only to illustrate the present invention and are not intended to limit the scope of the present invention. Any obvious modifications or changes made to the present invention do not depart from the spirit and scope of the present invention.

[0032] Example: See Figures 1 to 12 In the embodiment of the present invention, an axial flow check valve for municipal pipelines includes a liquid inlet pipe 1 and a liquid outlet pipe 2. A valve body shell 3 is fixedly arranged between the liquid inlet pipe 1 and the liquid outlet pipe 2. A limit shell 6 is arranged inside the valve body shell 3. The inner end of the liquid outlet pipe 2 is fixedly connected to the limit shell 6 by a guide fixing block 9. A valve stem 5 is slidably arranged in the limit shell 6. A valve disc 4 is fixedly arranged at the outer end of the valve stem 5. A fitting sealing ring 41 is fixedly arranged at the inner end of the liquid inlet pipe 1 and the fitting sealing ring 41 is fixed to the inner end of the liquid inlet pipe 1. The valve disc 4 is arranged accordingly, and a first spring 7 is arranged on the outside of the valve stem 5 in the limit housing 6. The valve stem 5 has a limit portion 11, and a guide groove 10 cooperating with the limit portion 11 is opened on the inside of the limit housing 6. The municipal water flowing through is diverted by the diversion fixing block 9, and the limit housing 6 is also fixed. The valve disc 4, the valve stem 5, the first spring 7 and the fitting sealing ring 41 cooperate to control the opening and closing of the valve body. The guide groove 10 and the limit portion 11 cooperate to prevent the valve disc 4 and the valve stem 5 from rotating.

[0033] A pressure dividing device 18 is provided above the valve body shell 3 . The liquid inlet pipe 1 is connected to the pressure dividing device 18 via a first connecting pipe 19 , and the liquid outlet pipe 2 is connected to the pressure dividing device 18 via a second connecting pipe 20 .

[0034] A first cavity space 8 is provided on the inner side of the limit shell 6, and a crossbeam 12 is fixedly provided on the inner side of the first cavity space 8 and the inner wall of the limit shell 6. A bevel gear transmission mechanism 13 is provided on one side of the crossbeam 12 for rotation through a rotating shaft, and a limit fixing block 14 is fixedly provided on one side of the bevel gear transmission mechanism 13. A straight rack 15 is provided between the bevel gear transmission mechanism 13 and the limit fixing block 14, and the straight rack 15 is meshed with one of the gears in the bevel gear transmission mechanism 13. An internal rack 51 is provided on the valve stem 5, and the internal rack 51 is meshed with another gear in the bevel gear transmission mechanism 13. The straight rack 15 passes through the limit shell 6 and the valve body shell 3 and is connected to the pressure dividing device 18. A sealing shell 16 is fixedly provided between the valve body shell 3 and the limit shell 6 on the outside of the straight rack 15. The bevel gear transmission mechanism 13 is driven to rotate by the internal rack 51 in the valve stem 5, and then the straight rack 15 is driven to move up and down, which is convenient for controlling the opening and closing of the pressure dividing device 18.

[0035] A buffer device 17 is provided on one side of the limit housing 6, and the buffer device 17 includes a first outer shell 171, the inner end of the first outer shell 171 is fixedly connected to the limit housing 6, and an inner shell 172 is fixedly provided on the inner side of the first outer shell 171, and a second cavity space 173 is formed between the first outer shell 171 and the inner shell 172, and a plurality of flow holes 174 are evenly provided on the inner shell 172. A moving rod 176 is slidingly provided on the inner side of the first outer shell 171, and a first piston 177 is fixedly provided on the inner end of the moving rod 176. The outer diameter of the first piston 177 is the same as the inner diameter of the inner shell 172, and an inner groove 179 is provided on the outer end of the moving rod 176 to cooperate with the valve stem 5. A second spring 178 is provided on one side of the moving rod 176, and a first boss 175 is fixedly provided on the inside of the second spring 178 at the bottom of the first outer shell 171. Both sides of the first piston 177 and the second cavity space 1 73 is filled with oil, and the cooperation of the moving rod 176, the first piston 177 and the second spring 178 provides resistance when the valve stem 5 is opened. The moving rod 176 and the first piston 177 move toward the side of the first boss 175. The first piston 177 is resisted by the second spring 178. At the same time, the oil on the side of the first boss 175 is fed into the second cavity space 173 through the plurality of flow holes 174, and then the oil in the second cavity space 173 is fed to the moving rod through the plurality of flow holes 174. In the space on one side of 176, the valve stem 5 drives the valve disc 4 to open slowly, reducing the impact of the negative water hammer effect. The first boss 175 limits the first piston 177 and prevents the second spring 178 from being over-compressed. The valve stem 5 and the moving rod 176 are slidably connected. The buffer device 17 does not affect the resetting speed of the valve stem 5 (the resetting in the buffer device 17 only relies on the elastic force of the second spring 178, so the resetting time is longer), preventing the valve disc 4 and the valve stem 5 from not closing in time, thereby improving the practicality of the device.

[0036] The pressure dividing device 18 includes a second outer shell 181, a second piston 182 is slidably provided on the inner side of the second outer shell 181, and the outer end of the straight rack 15 is fixedly connected to the lower end surface of the second piston 182, a third piston 184 is provided on the inner side of the second outer shell 181 above the second piston 182, a third cavity space 183 is formed between the second piston 182 and the third piston 184, and the third cavity space 183 is filled with air, a liquid passage 185 is provided in the middle of the third piston 184 to cooperate with the first connecting pipe 19 and the second connecting pipe 20, a third spring 186 is provided on the inner side of the second outer shell 181 above the third piston 184, and the second outer shell 181 is provided with a plurality of springs. A second boss 187 is fixedly provided on the top, and a vent hole 188 is provided on the second outer shell 181. The displacement of the valve stem 5 drives the straight rack 15 to move, so that the second piston 182 is displaced, and the air in the third cavity space 183 is transmitted to the third piston 184 to move (the principle of air compressibility and expansion can also be used to slow down the movement speed of the third piston 184). The liquid channel 185 serves as a bridge to connect the first connecting pipe 19 and the second connecting pipe 20, reducing the pressure exerted by the municipal water in the liquid inlet pipe 1 on the valve disc 4, slowing down the speed of opening or closing of the valve disc 4, and playing a certain protective role on the entire valve body. The second boss 187 plays a limiting role and also prevents the third spring 186 from being over-compressed.

[0037] When the device is in use, the municipal water in the liquid inlet pipe 1 pushes the valve disc 4 and the valve stem 5 to move toward the side of the liquid outlet pipe 2, the first spring 7 is compressed, and the inner rack 51 on the valve stem 5 drives the straight rack 15 to move upward through the bevel gear transmission mechanism 13, so that the second piston 182 moves upward, and the air in the third cavity space 183 is compressed, which also gives the third piston 184 an upward force, and the third spring 186 is compressed. When the liquid passage 185 is gradually connected with the first connecting pipe 19 and the second connecting pipe 20, the municipal water in the liquid inlet pipe 1 is diverted and directly enters the liquid outlet. The oil in the second cavity space 173 is fed through the plurality of flow holes 174. Then, the oil in the second cavity space 173 is fed through the plurality of flow holes 174 to the space on the side of the moving rod 176, thereby providing another portion of resistance, further delaying the opening of the valve disc 4 and the valve stem 5. Opening speed: When the valve disc 4 and the valve stem 5 are fully opened, the straight rack 15 rises to the highest point, and the third piston 184 also moves to the highest point. At this time, the third piston 184 blocks the communication between the first connecting pipe 19 and the second connecting pipe 20, and the municipal water in the liquid inlet pipe 1 flows directly to the liquid outlet pipe 2 through the valve disc 4. When the device is closed, the valve disc 4 and the valve stem 5 move to the side of the liquid inlet pipe 1, and the valve stem 5 disengages from the inner groove 179. The moving rod 176 and the first piston 177 gradually recover under the elastic force of the second spring 178, and the third piston 177 gradually recovers. The second piston 182 is driven down by the spur rack 15, and the third piston 184 also descends accordingly. The air in the third cavity space 183 is expanded, slowing down the movement speed of the valve disc 4 and the valve stem 5. When the third piston 184 descends to a certain height, the liquid passage 185 is gradually connected with the first connecting pipe 19 and the second connecting pipe 20. The municipal water in the liquid inlet pipe 1 is diverted and directly enters the liquid outlet pipe 2, avoiding repeated pressure in the liquid inlet pipe 1 (water hammer effect), prompting the valve disc 4 to block the liquid inlet pipe 1, and thus extending the service life of the valve body.

[0038] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above and that the invention can be embodied in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as illustrative and non-restrictive, and the scope of the invention is defined by the appended claims, not the foregoing description, and all variations within the meaning and range of equivalents of the claims are intended to be included therein. Any reference sign in a claim should not be construed as limiting the claim to which it relates.

[0039] In addition, it should be understood that although this specification is described in terms of implementation methods, not every implementation method contains only one independent technical solution. This narrative method of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.

Claims

1. An axial flow check valve for municipal pipelines, comprising a liquid inlet pipe (1) and a liquid outlet pipe (2), characterized in that: A valve body shell (3) is fixedly provided between the liquid inlet pipe (1) and the liquid outlet pipe (2), a limiting shell (6) is provided inside the valve body shell (3), the inner end of the liquid outlet pipe (2) is fixedly connected to the limiting shell (6) through a guide fixing block (9), a valve stem (5) is slidably provided in the limiting shell (6), a valve flap (4) is fixedly provided at the outer end of the valve stem (5), a fitting sealing ring (41) is fixedly provided at the inner end of the liquid inlet pipe (1), and the fitting sealing ring (41) and the valve flap (4) are provided correspondingly, a first spring (7) is provided on the outer side of the valve stem (5) and located in the limiting shell (6), a limiting portion (11) is provided on the valve stem (5), and a guide groove (10) is provided on the inner side of the limiting shell (6) to cooperate with the limiting portion (11); A pressure dividing device (18) is provided above the valve body housing (3); the liquid inlet pipe (1) is connected to the pressure dividing device (18) via a first connecting pipe (19); and the liquid outlet pipe (2) is connected to the pressure dividing device (18) via a second connecting pipe (20); A first cavity space (8) is provided on the inner side of the limiting shell (6), and a crossbeam (12) is fixedly provided on the inner side of the first cavity space (8) and the inner wall of the limiting shell (6). A bevel gear transmission mechanism (13) is provided on one side of the crossbeam (12) for rotation via a rotating shaft, and a limiting fixed block (14) is fixedly provided on one side of the bevel gear transmission mechanism (13). A spur rack (15) is provided between the bevel gear transmission mechanism (13) and the limiting fixed block (14), and the spur rack (15) is meshed with one of the gears in the bevel gear transmission mechanism (13). An inner rack (51) is provided on the valve stem (5), and the inner rack (51) is meshed with another gear in the bevel gear transmission mechanism (13). The spur rack (15) passes through the limiting shell (6) and the valve body shell (3) and is connected to the pressure dividing device (18).

2. The axial flow check valve for municipal pipeline according to claim 1, characterized in that: A sealing housing (16) is fixedly provided between the valve body shell (3) and the limit housing (6) and located outside the spur rack (15).

3. The axial flow check valve for municipal pipelines according to claim 2, characterized in that: The pressure dividing device (18) includes a second outer shell (181), a second piston (182) is slidably provided on the inner side of the second outer shell (181), and the outer end of the spur rack (15) is fixedly connected to the lower end surface of the second piston (182), a third piston (184) is provided on the inner side of the second outer shell (181) above the second piston (182), a third cavity space (183) is formed between the second piston (182) and the third piston (184), a liquid passage (185) is provided in the middle of the third piston (184) to cooperate with the first connecting pipe (19) and the second connecting pipe (20), a third spring (186) is provided on the inner side of the second outer shell (181) above the third piston (184), and a vent hole (188) is provided on the second outer shell (181).

4. The axial flow check valve for municipal pipeline according to claim 3, characterized in that: The third cavity space (183) is filled with air.

5. The axial flow check valve for municipal pipeline according to claim 4, characterized in that: A second boss (187) is fixedly provided on the top of the second outer shell (181).

6. The axial flow check valve for municipal pipelines according to any one of claims 1 to 5, characterized in that: A buffer device (17) is provided on one side of the limiting shell (6), and the buffer device (17) includes a first outer shell (171), an inner end portion of the first outer shell (171) is fixedly connected to the limiting shell (6), an inner shell (172) is fixedly provided on the inner side of the first outer shell (171), a second cavity space (173) is formed between the first outer shell (171) and the inner shell (172), a plurality of flow holes (174) are evenly provided on the inner shell (172), a moving rod (176) is slidably provided on the inner side of the first outer shell (171), a first piston (177) is fixedly provided on the inner end portion of the moving rod (176), and a second spring (178) is provided on one side of the moving rod (176) located on the inner side of the inner shell (172).

7. The axial flow check valve for municipal pipeline according to claim 6, characterized in that: The outer diameter of the first piston (177) is the same as the inner diameter of the inner housing (172).

8. The axial flow check valve for municipal pipelines according to claim 7, characterized in that: The outer end of the moving rod (176) is provided with an inner groove (179) that cooperates with the valve stem (5).

9. The axial flow check valve for municipal pipelines according to claim 8, characterized in that: Both sides of the first piston (177) and the second cavity space (173) are filled with oil.

10. The axial flow check valve for municipal pipelines according to claim 9, characterized in that: A first boss (175) is fixedly provided on the inner side of the second spring (178) at the bottom of the first outer shell (171).

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