A self-locking backflow preventer

Abstract

The present invention belongs to the field of backflow preventers, and particularly relates to a self-locking backflow preventer, which comprises a valve body. A working housing is provided at the upper part of the valve body, and a top cover is connected to the working housing. A first check valve is provided on one side inside the valve body, and a second check valve is provided on the other side inside the valve body. A drain pipe is provided on the outer wall of the valve body away from the top cover. A plug is provided at the bottom of the drain pipe, and a first drainage cover is fixedly provided on the drain pipe. A rotating shaft is rotatably connected to the middle of the first drainage cover, and a second drainage cover is connected to the rotating shaft. The rotation of the second drainage cover relative to the first drainage cover can close and let water through the drain pipe. During actual use, the plug is taken out and the bottom of the drain pipe is connected to the drainage system. When the second check valve is damaged and causes backflow, the first check valve can be locked to avoid backflow pollution.

Description

Technical Field

[0001] The present invention belongs to the field of backflow preventers, and particularly relates to a self-locking backflow preventer. Background Art

[0002] Backflow preventers mainly play a role in preventing backflow in the current domestic drinking water pipelines, preventing backflow pollution. The existing backflow preventers mostly stay in the form of simply splicing two check valves. In the actual application process, the following problems are found:

[0003] 1. The double-check valve structure makes it difficult to repair the internal check valve.

[0004] 2. When the check valve fails and water flows back, it is impossible to lock the check valve in time, thus easily causing backflow pollution.

[0005] 3. At present, there are some backflow preventer fault locking structures, but they all require manual operation and cannot be automatically locked according to the backflow situation. Summary of the Invention

[0006] The purpose of the present invention is to propose a self-locking backflow preventer for the above problems existing in the prior art.

[0007] To achieve the above purpose, the present invention adopts the following technical solutions: A self-locking backflow preventer includes a valve body. A working housing is provided on the upper part of the valve body, and a top cover is connected to the working housing. A first check valve is provided on one side inside the valve body, and a second check valve is provided on the other side inside the valve body. A drain pipe is provided on the outer wall of the valve body away from the top cover. A plug is provided at the bottom of the drain pipe. A first drainage cover is fixedly provided on the drain pipe. A rotating shaft is rotatably connected to the middle of the first drainage cover. A second drainage cover is connected to the rotating shaft. The rotation of the second drainage cover relative to the first drainage cover can close and open the drain pipe. During actual use, the plug is taken out, and the bottom of the drain pipe is connected to the drainage system.

[0008] Preferably, flange plates are provided on both sides of the valve body. An exhaust pipe is provided in the middle of the top cover. A first test valve is further provided on the top cover. A second test valve is provided at the position in front of the first check valve in the valve body. A third test valve is provided at the position behind the second check valve in the valve body. The first test valve, the second test valve, and the third test valve are prior art and will not be elaborated. The exhaust pipe is externally connected to an exhaust valve.

[0009] Preferably, the first check valve includes a first sealing ring fixedly arranged on the valve body. The first sealing ring is connected with a valve body assembly through a plurality of connecting rods. The valve body assembly includes a fixed sleeve fixedly connected with the connecting rods. A valve rod is slidably connected to the middle of the fixed sleeve. The valve rod is connected with the bottom of the fixed sleeve through a spring. A sliding sleeve is slidably arranged outside the fixed sleeve. One end of the valve rod passes through the bottom of the fixed sleeve and is connected to the sliding sleeve. A valve plate is fixedly connected to the outer circumferential surface of the sliding sleeve. The valve plate cooperates with the first sealing ring to achieve sealing.

[0010] Preferably, the second check valve includes a second sealing ring fixedly arranged on the valve body. The second sealing ring is connected with a valve body assembly.

[0011] Preferably, a plurality of first drain ports distributed circumferentially are formed on the first drain cover. A plurality of second drain ports capable of communicating with the first drain ports one by one are formed on the second drain cover.

[0012] Preferably, a gear is fixedly connected to the upper end of the rotating shaft. A connecting plate is fixedly arranged on the sliding sleeve of the first check valve. A rack is fixedly arranged on the connecting plate. The rack is in meshing transmission with the gear.

[0013] Preferably, a slope is arranged on one side of the second drain port. The design of this slope enables the spiral force generated when the water flows down to give a driving force to the rack towards the movement trend of the first sealing ring.

[0014] Preferably, two support rods are fixedly arranged on the upper side of the drain pipe. The upper ends of the two support rods are fixedly connected to a protection box body. The rack extends into the protection box body and is in meshing transmission with the gear.

[0015] Preferably, the rack is in sliding and sealing connection with the protection box body through a sealing ring. The rotating shaft is in rotating and sealing connection with the protection box body through a sealing ring. A slider is slidably and sealingly arranged at one end of the protection box body far away from the rack. A toothed locking block is fixedly arranged on the slider. A baffle for limiting the slider is arranged at the end of the protection box body.

[0016] Compared with the traditional backflow preventer, the present application can lock the first check valve further through the flowing state of the water when the second check valve leaks and flows back, so as to avoid polluting the water inlet source. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 is a perspective view of the present invention;

[0018] Figure 2 is a top view of the present invention;

[0019] Figure 3 is a side view of the present invention;

[0020] Figure 4 This is the front view of the present invention;

[0021] Figure 5 It is Figure 2 the isometric sectional view at A-A in

[0022] Figure 6 It is Figure 4 the sectional view at B-B in

[0023] Figure 7 It is Figure 2 the isometric sectional view at C-C in

[0024] Figure 8 It is Figure 7 the partial enlarged view at D in

[0025] Figure 9 It is the sectional view of the internal structure of the protection box in the second embodiment;

[0026] Figure 10 It is the schematic diagram of the locked state of the internal part of the protection box in the second embodiment.

[0027] In the figure: valve body 1, working housing 2, top cover 3, exhaust pipe 4, first test valve 5, third test valve 6, flange 7, second test valve 8, first sealing ring 9, connecting rod 10, fixed sleeve 11, valve rod 12, spring 13, sliding sleeve 14, protection box 15, second sealing ring 16, drain pipe 17, connecting plate 18, rack 19, gear 20, support rod 21, first drainage cover 22, first drainage port 23, second drainage cover 24, inclined surface 25, plug 26, second drainage port 27, rotating shaft 28, valve plate 29, slider 30, toothed locking block 31, baffle 32. Specific Embodiments

[0028] The following are specific embodiments of the present invention and in combination with the accompanying drawings, the technical solutions of the present invention are further described, but the present invention is not limited to these embodiments.

[0029] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "inner", "lower", etc. is based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship in which the product of the present invention is usually placed during use. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present invention. In addition, the terms "first", "second", etc. are only used for descriptive distinction and cannot be understood as indicating or implying relative importance.

[0030] Embodiment 1:

[0031] Combined with the attachedFigure 1-8 , a self-locking backflow preventer, comprising a valve body 1. A working housing 2 is provided at the upper part of the valve body 1. A top cover 3 is connected to the working housing 2. A first check valve is provided on one side inside the valve body 1, and a second check valve is provided on the other side inside the valve body 1. A drain pipe 17 is provided on the outer wall of the valve body 1 away from the top cover 3. A plug 26 is provided at the bottom of the drain pipe 17. A first drain cover 22 is fixedly provided on the drain pipe 17. A rotating shaft 28 is rotatably connected to the middle of the first drain cover 22. A second drain cover 24 is connected to the rotating shaft 28. The relative rotation of the second drain cover 24 with respect to the first drain cover 22 can close and allow water to pass through the drain pipe 17. When in use, the plug 26 is opened and connected to an external drainage system.

[0032] Furthermore, flange plates 7 are provided on both sides of the valve body 1. An exhaust pipe 4 is provided in the middle of the top cover 3. A first test valve 5 is further provided on the top cover 3. A second test valve 8 is provided at the front side position of the valve body 1 in front of the first check valve. A third test valve 6 is provided at the rear side position of the valve body 1 behind the second check valve.

[0033] Furthermore, the first check valve includes a first sealing ring 9 fixedly provided on the valve body 1. The first sealing ring 9 is connected to a valve body assembly through a plurality of connecting rods 10. The valve body assembly includes a fixed sleeve 11 fixedly connected to the connecting rod 10. A valve rod 12 is slidably connected to the middle of the fixed sleeve 11. The valve rod 12 is connected to the bottom of the fixed sleeve 11 through a spring 13. A sliding sleeve 14 is slidably provided outside the fixed sleeve 11. One end of the valve rod 12 passes through the bottom of the fixed sleeve 11 and is connected to the sliding sleeve 14. A valve plate 29 is fixedly connected to the outer circumferential surface of the sliding sleeve 14. The valve plate 29 cooperates with the first sealing ring 9 to achieve sealing.

[0034] Furthermore, the second check valve includes a second sealing ring 16 fixedly provided on the valve body 1. The second sealing ring 16 is connected to a valve body assembly.

[0035] Furthermore, a plurality of first drain ports 23 distributed in a circumferential manner are provided on the first drain cover 22. A plurality of second drain ports 27 capable of corresponding and communicating with the first drain ports 23 one by one are provided on the second drain cover 24.

[0036] Furthermore, a gear 20 is fixedly connected to the upper end of the rotating shaft 28. A connecting plate 18 is fixedly provided on the sliding sleeve 14 of the first check valve. A rack 19 is fixedly provided on the connecting plate 18. The rack 19 is in meshing transmission with the gear 20.

[0037] Furthermore, an inclined surface 25 is provided on one side of the second drain port 27. The design of this inclined surface 25 enables the spiral force generated when water flows down to give a driving force to the rack 19 towards the movement trend of the first sealing ring 9.

[0038] Furthermore, two support rods 21 are fixedly arranged on the upper side of the drain pipe 17. The upper ends of the two support rods 21 are fixedly connected to the protection box body 15, and the rack 19 extends into the protection box body 15 and is in transmission cooperation with the gear 20. The support form of the protection box body 15 can be changed according to actual needs, and the shape of the water-facing surface of the protection box body can also be changed to achieve the effect of reducing resistance.

[0039] During the actual use of this application, water flows in from the direction of the first check valve. After reaching a certain water pressure, the valve plate 29 of the first check valve is pushed, compressing the spring 13. The water flows through the first check valve and enters the space between the valve body 1 and the working housing 2. When the valve plate 29 of the first check valve 29 moves, the movement of the sliding sleeve 14 drives the rack 19 to move, thereby driving the gear 20 to rotate, and then driving the second drainage cover 24 to rotate, so that the second drainage port 27 is staggered from the first drainage port 23 to achieve sealing.

[0040] The water continues to flow in the valve body 1. As the water pressure increases, the second check valve is pushed open to achieve water passage.

[0041] After the water passage ends, the first check valve and the second check valve return to their initial positions. At this time, the rack 19 drives the gear 20 to rotate back, driving the second drainage cover 24 to rotate. As a result, the second drainage port 27 is reconnected to the first drainage port 23 to achieve drainage, ensuring that there is no water stored inside the valve body 1 when there is no water passage.

[0042] If the second check valve is damaged and water flows back into the valve body 1, when the water falls from the second drainage port 27, due to the existence of the inclined surface 25, a rotational tendency is given to the second drainage cover 24. This rotational tendency can cause the rack 19 to tend to move towards the first sealing ring 9, pressing the valve plate 29 of the first check valve against the first sealing ring 9 to achieve reverse flow sealing self-locking and prevent the backflow water from polluting the water source end.

[0043] Embodiment 2:

[0044] Combined with the attached Figure 9 、 10 On the basis of Embodiment 1, the rack 19 is slidably and sealingly connected to the protection box body 15 through a sealing ring, the rotating shaft 28 is rotatably and sealingly connected to the protection box body 15 through a sealing ring. A slider 30 is slidably and sealingly arranged at one end of the protection box body 15 away from the rack 19. A toothed locking block 31 is fixedly arranged on the slider 30, and a baffle 32 for limiting the slider 30 is arranged at the end of the protection box body 15.

[0045] The inside of the protection box body 15 is integrally sealed. When the backflow preventer works normally, the first check valve is normally opened, and the rack 19 extends into the inside of the protection box body 15. At this time, the water pressure inside the valve body 1 increases, and the pressure pushes the slider 30 to slide towards the inside of the sliding box body 15, but it stops due to the limitation of the end of the rack 19.

[0046] If the second check valve returns water to the inside of the valve body 1, while draining water at the second drain cover 24, if the drainage rate cannot match the water return speed, the water pressure inside the valve body 1 increases at this time, pushing the slider 30 to move towards the gear 20, and the toothed locking block 31 contacts and locks with the gear 20, thereby locking the movement of the rack 19. Thus, when the water return degree further intensifies, the first check valve is completely locked. When the water return situation is handled and the water pressure inside the valve body 1 returns to normal, the slider 30 resets under the action of the internal air pressure and returns to the normal working state.

[0047] The above are only the embodiments of the present invention, and do not limit the patent protection scope of the present invention. Any equivalent structure or equivalent process transformation made by using the content of the specification and drawings of the present invention, or directly or indirectly applied in other related technical fields, shall be similarly included in the patent protection scope of the present invention.

Claims

1. A self-locking backflow preventer, comprising a valve body (1), a working housing (2) being provided on the upper part of the valve body (1), a top cover (3) being connected to the working housing (2), characterized in that: A first check valve is provided on one side of the valve body (1), and a second check valve is provided on the other side of the valve body (1). A drain pipe (17) is provided on the outer wall of the valve body (1) away from the top cover (3). A plug (26) is provided at the bottom of the drain pipe (17). A first drain cover (22) is fixedly provided on the drain pipe (17). The middle part of the first drain cover (22) is rotatably connected to a rotating shaft (28). A second drain cover (24) is connected to the rotating shaft (28). The second drain cover (24) rotates relative to the first drain cover (22) to seal and pass water through the drain pipe (17). The first check valve comprises a first sealing ring (9) fixedly arranged on a valve body (1), the first sealing ring (9) being connected to a valve body assembly via a plurality of connecting rods (10); the valve body assembly comprises a fixed sleeve (11) fixedly connected to the connecting rod (10), a sliding sleeve (14) being slidably arranged outside the fixed sleeve (11), a valve plate (29) being fixedly connected to the outer circumferential surface of the sliding sleeve (14), the valve plate (29) cooperating with the first sealing ring (9) to achieve sealing; The first drainage cover (22) is provided with a plurality of first drainage openings (23) distributed circumferentially, and the second drainage cover (24) is provided with a plurality of second drainage openings (27) that can be connected to the first drainage openings (23) in a one-to-one correspondence; The upper end of the rotating shaft (28) is fixedly connected to a gear (20); a connecting plate (18) is fixedly provided on the sliding sleeve (14) of the first check valve; a rack (19) is fixedly provided on the connecting plate (18); and the rack (19) is meshed with the gear (20) for transmission; A slope (25) is provided on one side of the second drain port (27); After the water flow is finished, the first check valve and the second check valve return to their initial positions. At this time, the rack (19) drives the gear (20) to rotate, driving the second drainage cover (24) to rotate, so that the second drainage port (27) is reconnected with the first drainage port (23), achieving drainage, and ensuring that no water is stored inside the valve body (1) when no water is flowing; If the second check valve is damaged and water flows back into the valve body (1), when the water flows down from the second drain port (27), the second drain cover (24) will be given a rotation tendency due to the presence of the inclined surface (25). This rotation tendency can cause the rack (19) to move toward the first sealing ring (9), so that the valve plate (29) of the first check valve is pressed against the first sealing ring (9), thereby achieving a self-locking backflow seal and preventing the return water from contaminating the water source.

2. A self-locking backflow preventer according to claim 1, characterized in that: Flanges (7) are provided on both sides of the valve body (1), an exhaust pipe (4) is provided in the middle of the top cover (3), a first test valve (5) is also provided on the top cover (3), a second test valve (8) is provided on the valve body (1) at a position in front of the first check valve, and a third test valve (6) is provided on the valve body (1) at a position in rear of the second check valve.

3. A self-locking backflow preventer according to claim 1, characterized in that: A valve stem (12) is slidably connected to the middle of the fixed sleeve (11); the valve stem (12) is connected to the bottom of the fixed sleeve (11) via a spring (13); one end of the valve stem (12) passes through the bottom of the fixed sleeve (11) and is connected to the sliding sleeve (14).

4. A self-locking backflow preventer according to claim 1, characterized in that: The second check valve comprises a second sealing ring (16) fixedly arranged on the valve body (1), and the second sealing ring (16) is connected to a valve body assembly.

5. A self-locking backflow preventer according to claim 1, characterized in that: Two support rods (21) are fixedly arranged on the upper side of the drainage pipe (17), the upper ends of the two support rods (21) are fixedly connected to the protection box (15), and the rack (19) extends into the protection box (15) and cooperates with the gear (20) for transmission.

6. A self-locking backflow preventer according to claim 1, characterized in that: The rack (19) is connected to the protection box (15) in a sliding and sealing manner via a sealing ring, the rotating shaft (28) is connected to the protection box (15) in a rotating and sealing manner via a sealing ring, a sliding block (30) is provided in the protection box (15) at one end away from the rack (19), a toothed locking block (31) is fixed on the slider (30), and a baffle (32) is provided at the end of the protection box (15) for limiting the slider (30).

Images