Self-draining low resistance backflow preventer

Abstract

The application discloses a self-draining low-resistance backflow preventer, relates to the technical field of backflow preventers, and further comprises a water draining mechanism for automatically draining water in a cavity after water seepage, an automatic adjusting mechanism for driving a first check valve and a second check valve to move, and a cooperation mechanism for enabling the automatic adjusting mechanism to automatically work without using a spring when backflow occurs. The device uses the cooperation mechanism and the automatic adjusting mechanism to replace the spring to assist in closing the first check valve and the second check valve during use, and due to the structural properties of the cooperation mechanism and the automatic adjusting mechanism, elastic fatigue does not occur, the use stability of the device is improved, and due to the absence of an additional power source, the energy-saving effect is achieved. When backflow occurs, the water in the cavity can be automatically drained through the water draining mechanism, so that the self-draining effect is achieved.

Description

Technical Field

[0001] This invention relates to the field of backflow prevention technology, and more particularly to a self-draining, low-resistance backflow prevention device. Background Technology

[0002] The low-resistance backflow preventer consists of a main valve with a two-stage check valve and an external drain valve. It is composed of two independent spring-assisted elastic seal check valves and an independent hydraulic differential drain valve in the intermediate pressure reducing chamber. It is a hydraulic control combination device that strictly limits the flow of pressurized water in the pipeline to only one direction. Its function is to prevent the backflow of the medium in the pipeline under any working condition, so as to avoid backflow pollution.

[0003] When the pipeline pressure is normal, water can easily flow from the inlet to the outlet through the two check valves. Due to the local resistance of the first check valve, the pressure inside the valve chamber is slightly lower than the inlet pressure, while the water pressure under the diaphragm is the same as the inlet pressure. Therefore, the water pressure under the diaphragm is greater than the water pressure above the diaphragm, keeping the safety relief valve closed. At this time, the water in the pipeline flows normally. Figure 1 As shown. When all valves on the pipeline downstream of the backflow preventer are closed, the water flow is stagnant. At this time, if the inlet pressure remains unchanged, the water pressure in the valve chamber is still slightly lower than the inlet pressure, and the safety drain valve remains closed.

[0004] When the pressure in the pipe downstream of the backflow preventer rises and exceeds the supply pressure (i.e., back pressure), if the second check valve does not leak, the high-pressure water will not flow back into the valve chamber, and the valve chamber will maintain the pressure during normal flow. Therefore, the safety drain valve will not activate to drain water. If the second check valve leaks, the pressure in the valve chamber will increase due to the leak, and the drain valve will automatically drain water. This reduces the pressure of the high-pressure water flow on the first check valve, effectively preventing water from flowing back from the first check valve to the upstream pipe. If the water supply system pressure continuously decreases, the pressure at the lower part of the diaphragm controlling the safety drain valve will also decrease. When the inlet pressure drops to 0.02 MPa, the control spring of the safety drain valve extends, opening the safety drain valve to drain water. When the inlet pressure drops to zero or negative pressure, the safety drain valve will fully open, allowing air to enter the valve chamber and creating an air gap twice the diameter of the inlet, thus preventing siphon backflow. At this point, the water in the pipe stops flowing.

[0005] However, although existing low-resistance backflow preventers are regulated by differential pressure during use, they rely on springs for assisted closure during this process. To enable the springs to close, they remain under tension for extended periods. When the springs are under tension for a long time, they are prone to elastic fatigue. If the springs of the check valves experience elastic fatigue, the first check valve may not be able to reset in time when backflow occurs. If the water velocity is high at this point, backflow can easily occur, leading to water pollution. Summary of the Invention

[0006] The present invention addresses the problem of overly simplistic solutions in existing technologies by providing a significantly different solution. This invention provides a self-draining, low-resistance backflow preventer to address the issue that existing check valves rely on springs for assisted closure, but springs experience elastic fatigue during use, causing the check valve to fail to reset in time, thus leading to backflow.

[0007] The present invention adopts the following technical solution: a self-draining low-resistance backflow preventer, comprising a body, wherein a valve chamber for water passage is provided in the body, and a first check valve and a second check valve for preventing water backflow are respectively provided at both ends of the valve chamber, and a mating plate is provided on one side of the second check valve. The body is provided with a drain port, and further includes a draining mechanism for automatically draining water inside the cavity after seepage, an automatic adjustment mechanism for driving the first check valve and the second check valve to move, and a mating mechanism for enabling the automatic adjustment mechanism to work automatically without using a spring when backflow occurs. The two ends of the body are provided with mating grooves, and the two mating grooves are respectively located outside the first check valve and the second check valve. Each mating groove has a water passage port for penetrating the cavity at its bottom.

[0008] Furthermore, the draining mechanism includes a mating seat, which is disposed on the top of the main body, and a connecting groove is provided between the mating seat and the main body. A first valve plate is disposed inside the mating seat, a connecting column is disposed in the first valve plate, and a valve seat is disposed outside the first valve plate. The connecting column is disposed through the main body and located at the bottom of the main body. A second valve plate is disposed at the bottom end of the connecting column. A connecting spring is disposed between the second valve plate and the drain outlet, and the second valve plate is located above the drain outlet.

[0009] Furthermore, the mating mechanism includes a first connecting pipe and a second connecting pipe. A water-receiving plate is provided on the outer side of the second valve plate. One end of the first connecting pipe is located at the top of the mating groove on the side where the second valve plate is located, and the other end of the first connecting pipe is located on the outer side of the first valve plate. One end of the second connecting pipe is located at the top of the mating groove on the side where the first valve plate is located, and the other end of the second connecting pipe is connected to the water-receiving plate. A stop block is provided at the bottom of the other ends of both the first connecting pipe and the second connecting pipe, and a mating block is provided above the stop block.

[0010] Furthermore, in the initial state, the first and second connecting pipes are filled with liquid.

[0011] Furthermore, both of the aforementioned automatic adjustment mechanisms include a movable block, which is disposed within a mating groove. A connecting rod penetrating the cavity is disposed at the top of the movable block, and a connecting rack is disposed at the lower end of the other end of the connecting rod. A transmission gear is meshed with the connecting rack, and a connecting shaft is disposed within the transmission gear. A transmission rack is meshed with the lower part of the transmission gear, and the transmission rack is connected to the corresponding first and second check valves. Several guide plates are disposed on the outer sides of the first and second check valves, and a positioning post is disposed in each guide plate. The positioning post is connected to the main body.

[0012] Furthermore, the outer diameter of the moving block is the same as the inner diameter of the mating groove, and the cross-section of the connecting rod is U-shaped.

[0013] Furthermore, the water-receiving plate is hollow towards the water outlet, and the distance between the water-receiving plate and the second valve plate is greater than the moving distance of the moving block.

[0014] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0015] Firstly, the use of a combined cooperating mechanism and an automatic adjustment mechanism to open and close the first and second check valves eliminates the spring-assisted closing method found in existing backflow preventers. This avoids the spring fatigue caused by prolonged tension or compression, which prevents the spring from failing to provide effective reset force when backflow occurs, leading to delayed reset and water backflow from the inlet, causing water pollution. Furthermore, the combined use of the cooperating and automatic adjustment mechanisms not only assists in closing the first and second check valves but also actively closes and opens them, increasing practicality and ensuring no backflow occurs. This effectively reduces the occurrence of sewage backflow and water pollution, thus increasing the environmental friendliness of the device. Moreover, since it does not use electricity for control, relying entirely on the natural flow of water... The force-driven power source increases the energy efficiency of the device. During use, when water enters the cavity, some water flows through the inlet, causing the moving block to move. The moving block moves the automatic adjustment mechanism, which in turn moves the first and second valve plates, automatically opening the valves to allow water to flow. When the water flow is small, backflow may occur. The backflowing water enters the second connecting pipe through the water-receiving plate, pushing the moving block in the second connecting pipe to move. The moving block squeezes the water in the pipe, causing it to flow back into the mating groove, which lowers the moving block. This lowering of the moving block resets the valve plate via the automatic adjustment mechanism, thus preventing backflow. Furthermore, since there is water in the connecting pipe itself, when backflow occurs, only a small amount of water entering the connecting pipe is needed to move the moving block, increasing its movement speed and avoiding a long reaction time of the first valve plate that could cause backflow. The device can also be recycled, increasing its service life.

[0016] Secondly, the drainage mechanism can automatically drain the residual water in the cavity to avoid affecting the water flow. When the inlet water pressure is high during use, the water will enter the valve seat through the connecting groove, causing the first valve plate to move. The movement of the first valve plate drives the second valve plate to move through the connecting column. The second valve plate blocks the drain port, allowing the liquid to flow normally. When there is no water inlet, the first valve plate resets, driving the second valve plate to reset as well. At this time, the drain port is exposed, which can automatically drain the water in the cavity, achieving the effect of automatic drainage.

[0017] In summary, this device, through the cooperation mechanism and automatic adjustment mechanism, replaces the spring to assist in closing the first and second check valves during use. Due to the structural nature of the cooperation mechanism and automatic adjustment mechanism, elastic fatigue will not occur, increasing the stability of the device. Furthermore, since no additional power source is required, energy saving is achieved. In the event of backflow, the water in the cavity can be automatically discharged through the drain mechanism, thus achieving a self-draining effect. Attached Figure Description

[0018] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0019] Figure 1 This is a schematic diagram of the main structure of the present invention;

[0020] Figure 2 This is a schematic diagram showing the positional structure of the first connecting pipe and the second connecting pipe of the present invention;

[0021] Figure 3 This is a schematic diagram of the first perspective structure of the present invention;

[0022] Figure 4 This is a schematic diagram of the second perspective structure of the main section of the present invention;

[0023] Figure 5 For the present invention Figure 4 Enlarged structural diagram at point A in the middle.

[0024] Figure label:

[0025] 1. Body; 11. First check valve; 12. Second check valve; 13. Water inlet; 14. Fitting groove; 2. Drainage mechanism; 21. First valve plate; 22. Connecting column; 23. Valve seat; 24. Second valve plate; 25. Connecting spring; 26. Drainage outlet; 27. Connecting groove; 3. Fitting mechanism; 31. First connecting pipe; 32. Water-receiving plate; 33. Second connecting pipe; 34. Fitting block; 35. Stop block; 4. Automatic adjustment mechanism; 41. Guide plate; 42. Positioning column; 43. Connecting rack; 44. Transmission rack; 45. Transmission gear; 46. Connecting shaft; 47. Moving block; 48. Connecting rod. Detailed Implementation

[0026] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0027] The components of the embodiments of the invention described and shown in the accompanying drawings can typically be arranged and designed in a variety of different configurations. Therefore, the following detailed description of the embodiments of the invention provided in the drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention.

[0028] Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0029] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0030] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0031] The following is combined with Figures 1 to 5 As shown, this embodiment of the invention provides a self-draining low-resistance backflow preventer, including a body 1. The body 1 has a valve chamber for water flow. A first check valve 11 and a second check valve 12 are respectively provided at both ends of the valve chamber to prevent water backflow. A mating plate is provided on one side of the second check valve 12. The body 1 has a drain port 26. It also includes a draining mechanism 2 for automatically draining water from the cavity after seepage, an automatic adjustment mechanism 4 for driving the first check valve 11 and the second check valve 12 to move, and a mating mechanism 3 for automatically operating the automatic adjustment mechanism 4 without using a spring when backflow occurs. The body 1 has mating grooves 14 at both ends, and the two mating grooves 14 are respectively located outside the first check valve 11 and the second check valve 12. Each mating groove 14 has a water inlet 13 for penetrating the cavity at its bottom.

[0032] During operation, the cooperating mechanism 3 and the automatic adjustment mechanism 4 replace the spring to assist in closing the first check valve 11 and the second check valve 12. Due to the structural nature of the cooperating mechanism 3 and the automatic adjustment mechanism 4, elastic fatigue will not occur, which increases the stability of the device. Furthermore, since no additional power source is required, energy saving is achieved. In the event of backflow, the water in the cavity can be automatically discharged through the drain mechanism 2, thereby achieving self-drainage.

[0033] Specifically, the drain mechanism 2 includes a mating seat, which is located on the top of the body 1, and a connecting groove 27 is provided between the mating seat and the body 1. A first valve plate 21 is provided inside the mating seat, a connecting post 22 is provided in the first valve plate 21, and a valve seat 23 is provided outside the first valve plate 21. The connecting post 22 is provided through the body 1 to the bottom of the body 1, and a second valve plate 24 is provided at the bottom end of the connecting post 22. A connecting spring 25 is provided between the second valve plate 24 and the drain port 26, and the second valve plate 24 is located above the drain port 26.

[0034] During operation, the residual water in the cavity can be automatically discharged through the drain mechanism 2 to avoid affecting the water flow. When the inlet water pressure is high, the water will enter the valve seat 23 through the connecting groove 27, causing the first valve plate 21 to move. The movement of the first valve plate 21 drives the second valve plate 24 to move through the connecting column 22. The second valve plate 24 blocks the drain port 26, allowing the liquid to flow normally. When there is no water inlet, the first valve plate 21 resets, driving the second valve plate 24 to reset as well. At this time, the drain port 26 is exposed, allowing the water in the cavity to be automatically discharged, achieving the effect of automatic drainage.

[0035] Specifically, the mating mechanism 3 includes a first connecting pipe 31 and a second connecting pipe 33. A water-receiving plate 32 is provided on the outer side of the second valve plate 24. One end of the first connecting pipe 31 is located at the top of the mating groove 14 on the side where the second valve plate 24 is located, and the other end of the first connecting pipe 31 is located on the outer side of the first valve plate 21. One end of the second connecting pipe 33 is located at the top of the mating groove 14 on the side where the first valve plate 21 is located, and the other end of the second connecting pipe 33 is connected to the water-receiving plate 32. A stop block 35 is provided at the bottom of the other end of the first connecting pipe 31 and the second connecting pipe 33, and a mating block 34 is provided above the stop block 35.

[0036] Specifically, in the initial state, the first connecting pipe 31 and the second connecting pipe 33 are filled with liquid.

[0037] During operation, the water entering the pipe does not need to travel a long distance to move the corresponding mating block 34, ensuring the moving sensitivity of the mating block 34.

[0038] Specifically, both automatic adjustment mechanisms 4 include a moving block 47, which is disposed in the mating groove 14. The top of the moving block 47 is provided with a connecting rod 48 that penetrates the cavity. The lower end of the other end of the connecting rod 48 is provided with a connecting rack 43. The connecting rack 43 is meshed with a transmission gear 45. The transmission gear 45 is provided with a connecting shaft 46. The lower part of the transmission gear 45 is meshed with a transmission rack 44, which is connected to the corresponding first check valve 11 and second check valve 12. Several guide plates 41 are provided on the outside of the first check valve 11 and the second check valve 12, and each guide plate 41 is provided with a positioning post 42. The positioning post 42 is connected to the body 1.

[0039] Specifically, the outer diameter of the movable block 47 is the same as the inner diameter of the mating groove 14, and the cross-section of the connecting rod 48 is U-shaped.

[0040] During operation, the U-shaped design ensures the sealing of the mating groove 14, thereby guaranteeing the movement of the mating block 34.

[0041] Specifically, the water-receiving plate 32 is hollow facing the water outlet, and the distance between the water-receiving plate 32 and the second valve plate 24 is greater than the moving distance of the moving block 47.

[0042] When in operation, if the inlet water pressure is greater than the outlet water pressure, the inlet water will not enter the second connecting pipe 33, thus preventing the inlet water from affecting the use of the moving block 47. When the water flows back, the water receiving plate 32 can receive more water, increase the water pressure, thereby promoting the movement of the moving block 47 and ensuring that the first check valve 11 can be closed in time.

[0043] Working principle: During use, water enters the cavity from one end of the main body 1, thus generating a thrust on the first check valve 11. As the water enters the cavity, some enters the mating groove 14 through the water inlet 13, causing water to be injected below the moving block 47 in the mating groove 14 on the left side of the first check valve 11. As the water volume increases, the moving block 47 in the left mating groove 14 moves upward. However, since there is already water above the moving block 47, the water above the moving block 47 is squeezed and enters the second connecting pipe 33. This causes the mating block 34 at the end of the second connecting pipe 33 to contact the stop block 35, effectively preventing water from entering and affecting the movement of the moving block 47. Furthermore, during the movement of the left moving block 47... In this configuration, a connecting rod 48 is mounted on the top of the left movable block 47, and the other end of the connecting rod 48 is connected to the connecting rack 43. When the connecting rod 48 moves upward with the movable block 47, the connecting rack 43 also moves upward synchronously. Since the connecting rack 43 is meshed with the transmission gear 45, and the transmission gear 45 is meshed with the transmission rack 44, when the connecting rack 43 moves upward, it drives the transmission gear 45 to rotate. The rotation of the transmission gear 45 drives the transmission rack 44 to move. Furthermore, since the left transmission rack 44 is connected to the first check valve 11, the first check valve 11 opens, allowing water to enter the cavity. Simultaneously, some water also enters the right mating groove 14 through the first connecting pipe 31 at the water inlet, causing the movable block in the right mating groove 14 to... As the right-side moving block 47 moves downward, the connecting rod 48 connected to it drives the corresponding connecting rack 43 to move downward. The downward movement of the connecting rack 43 drives the transmission gear 45 connected to it to rotate, thereby driving the corresponding transmission rack 44 to move, causing the second check valve 12 to open. In use, the device automatically opens the first check valve 11 and the second check valve 12 through water pressure. Some water also enters the valve seat 23 through the connecting groove 27, causing the first valve plate 21 to move. The movement of the first valve plate 21 drives the second valve plate 24 to move via the connecting column 22. The second valve plate 24 blocks the drain port 26, allowing the liquid to flow normally. When there is no water intake, backflow may occur. As the water flows backward, it enters the second connecting pipe 33 through the water-receiving plate 32, pushing the mating block 34 inside the second connecting pipe 33 to move. This forces the water in the second connecting pipe 33 into the left mating groove 14, causing the moving block 47 inside the left mating groove 14 to descend. When the moving block 47 descends, it drives the connected rod 48 to descend, which in turn drives the connected rack 43 to descend, thereby resetting the first check valve 11. This achieves automatic closure. Furthermore, because the moving distance of the mating block 34 is short, the first check valve 11 reacts quickly, effectively preventing backflow. The moving block 47 on the right moves in the opposite direction, causing the second check valve 12 to also automatically close.At this time, there may still be water in the cavity. When the inlet water pressure decreases, the first valve plate 21 resets under the action of the connecting spring 25, thereby driving the second valve plate 24 to reset. At this time, the drain port 26 is exposed, allowing the water in the cavity to be automatically discharged, achieving the effect of automatic drainage.

[0044] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A self-draining low-resistance backflow preventer, comprising a body (1), wherein a valve chamber for water flow is provided in the body (1), and a first check valve (11) and a second check valve (12) for preventing water backflow are respectively provided at both ends of the valve chamber, and a mating plate is provided on one side of the second check valve (12), and a drain port (26) is provided in the body (1), characterized in that; It also includes a drainage mechanism (2) for automatically draining water from the cavity after seepage, an automatic adjustment mechanism (4) for driving the first check valve (11) and the second check valve (12) to move, and a cooperating mechanism (3) for enabling the automatic adjustment mechanism (4) to work automatically without using a spring when backflow occurs. The main body (1) is provided with a cooperating groove (14) at both ends, and the two cooperating grooves (14) are located on the outside of the first check valve (11) and the second check valve (12) respectively. Each cooperating groove (14) has a water inlet (13) at the bottom for penetrating the cavity. Both of the automatic adjustment mechanisms (4) include a moving block (47), which is set in the mating groove (14). The top of the moving block (47) is provided with a connecting rod (48) that passes through the cavity. The other end of the connecting rod (48) is provided with a connecting rack (43). The connecting rack (43) is meshed with a transmission gear (45). The transmission gear (45) is provided with a connecting shaft (46). The transmission gear (45) is meshed with a transmission rack (44) below it. The transmission rack (44) is connected to the corresponding first check valve (11) and second check valve (12). The first check valve (11) and second check valve (12) are provided with several guide plates (41) on their outer sides. Each guide plate (41) is provided with a positioning post (42). The positioning post (42) is connected to the body (1).

2. The self-draining low-resistance backflow preventer according to claim 1, characterized in that; The drain mechanism (2) includes a mating seat, which is located on the top of the body (1) and a connecting groove (27) is provided between the mating seat and the body (1). A first valve plate (21) is provided inside the mating seat, and a connecting column (22) is provided in the first valve plate (21). A valve seat (23) is provided outside the first valve plate (21). The connecting column (22) is provided through the body (1) and located at the bottom of the body (1). A second valve plate (24) is provided at the bottom end of the connecting column (22). A connecting spring (25) is provided between the second valve plate (24) and the drain port (26), and the second valve plate (24) is located above the drain port (26).

3. The self-draining low-resistance backflow preventer according to claim 2, characterized in that; The mating mechanism (3) includes a first connecting pipe (31) and a second connecting pipe (33). A water-receiving plate (32) is provided on the outside of the second valve plate (24). One end of the first connecting pipe (31) is located at the top of the mating groove (14) on the side where the second valve plate (24) is located, and the other end of the first connecting pipe (31) is located on the outside of the first valve plate (21). One end of the second connecting pipe (33) is located at the top of the mating groove (14) on the side where the first valve plate (21) is located, and the other end of the second connecting pipe (33) is connected to the water-receiving plate (32). A stop block (35) is provided at the bottom of the other end of the first connecting pipe (31) and the second connecting pipe (33), and a mating block (34) is provided above the stop block (35).

4. A self-draining low-resistance backflow preventer according to claim 3, characterized in that; In the initial state, the first connecting tube (31) and the second connecting tube (33) are filled with liquid.

5. A self-draining low-resistance backflow preventer according to claim 1, characterized in that; The outer diameter of the moving block (47) is the same as the inner diameter of the mating groove (14), and the cross-section of the connecting rod (48) is U-shaped.

6. A self-draining low-resistance backflow preventer according to claim 3, characterized in that; The water-receiving plate (32) is hollow facing the water outlet, and the distance between the water-receiving plate (32) and the second valve plate (24) is greater than the moving distance of the moving block (47).

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