Self-locking backflow preventer

Abstract

The invention belongs to the field of backflow preventers, and particularly relates to a self-locking backflow preventer which comprises a valve body, a working shell is arranged on the upper portion of the valve body, a top cover is connected to the working shell, a first check valve is arranged on one side of the interior of the valve body, and a second check valve is arranged on the other side of the interior of the valve body. A drainage pipe is arranged on the outer wall, away from the top cover, of the valve body, a plug is arranged at the bottom of the drainage pipe, a first drainage cover is fixedly arranged on the drainage pipe, a rotating shaft is rotationally connected to the middle of the first drainage cover, and a second drainage cover is connected to the rotating shaft; the second drainage cover rotates relative to the first drainage cover so that the drainage pipe can be closed and water can flow through the drainage pipe. In actual use, the plug is taken out, and the bottom of the drainage pipe is connected with a drainage system. When the second check valve is damaged and flows back, the first check valve is locked, and backflow pollution is avoided.

Description

Technical Field

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

[0002] Backflow preventers are mainly used to prevent backflow in existing drinking water pipelines to prevent backflow pollution. The existing backflow preventer structure is mostly in the form of two check valves simply spliced ​​together. In actual application, the following problems are found: 1. The double check valve structure makes it difficult to repair internal check valve failures; 2. When the check valve fails and backflow occurs, the check valve cannot be locked in time, which may easily cause backflow pollution; 3. Currently, some backflow preventers have fault locking structures, but they all require manual operation and cannot be automatically locked according to the backflow situation. Summary of the invention

[0003] The purpose of the present invention is to solve the above problems in the prior art and to provide a self-locking backflow preventer.

[0004] In order to achieve the above-mentioned purpose, the present invention adopts the following technical scheme: a self-locking backflow preventer, comprising a valve body, a working shell is provided on the upper part of the valve body, a top cover is connected to the working shell, a first check valve is provided on one side of the valve body, a second check valve is provided on the other side of 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 drain cover is fixedly provided on the drain pipe, the middle part of the first drain cover is rotatably connected to a rotating shaft, a second drain cover is connected to the rotating shaft, and the second drain cover rotates relative to the first drain cover to seal and pass water through the drain pipe. In actual use, the plug is removed and the bottom of the drain pipe is connected to the drainage system.

[0005] Preferably, flanges 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 also provided on the top cover, a second test valve is provided on the valve body in front of the first check valve, and a third test valve is provided on the valve body in the rear of the second check valve. The first test valve, the second test valve, and the third test valve are prior art and are not described in detail. The exhaust pipe is externally connected to the exhaust valve.

[0006] Preferably, the first check valve includes a first sealing ring fixedly arranged on the valve body, and the first sealing ring is connected to the valve body assembly through a plurality of connecting rods; the valve body assembly includes a fixed sleeve fixedly connected to the connecting rod, a valve stem is slidably connected to the middle of the fixed sleeve, the valve stem is connected to the bottom of the fixed sleeve through a spring, a sliding sleeve is slidably arranged on the outside of the fixed sleeve, one end of the valve stem 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, and the valve plate cooperates with the first sealing ring to achieve sealing.

[0007] Preferably, the second check valve comprises a second sealing ring fixedly arranged on the valve body, and the second sealing ring is connected to the valve body assembly.

[0008] Preferably, the first drain cover is provided with a plurality of first drain openings distributed circumferentially, and the second drain cover is provided with a plurality of second drain openings which can be connected to the first drain openings in a one-to-one correspondence.

[0009] Preferably, a gear is fixedly connected to the upper end of the rotating shaft, a connecting plate is fixedly provided on the sliding sleeve of the first check valve, a rack is fixedly provided on the connecting plate, and the rack is meshed with the gear for transmission.

[0010] Preferably, a slope is provided on one side of the second water outlet, and the design of the slope enables the spiral force generated when the water flows down to provide a driving force for the rack to move toward the first sealing ring.

[0011] Preferably, two support rods are fixedly provided on the upper side of the drain pipe, the upper ends of the two support rods are fixedly connected to the protection box body, and the rack extends into the protection box body and cooperates with the gear for transmission.

[0012] Preferably, the rack is connected to the protective box body in a sliding seal via a sealing ring, the rotating shaft is connected to the protective box body in a rotating seal via a sealing ring, a slider is provided in the sliding seal at one end of the protective box body away from the rack, a toothed locking block is fixed on the slider, and a baffle is provided at the end of the protective box body to limit the slider.

[0013] Compared with the traditional backflow preventer, the present application can further lock the first check valve by the downward flow of water when the second check valve leaks and flows back, so as to avoid contamination of the water source. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a stereogram of the present invention; Figure 2 A top view of the present invention; Figure 3 It is a side view of the present invention; Figure 4 It is the front view of the present invention; Figure 5 for Figure 2 Isometric section view at AA in the middle; Figure 6 for Figure 4 Sectional view at the middle BB; Figure 7 for Figure 2 Isometric section view at CC; Figure 8 for Figure 7 A partial enlarged view of point D in the middle; Fig. 9 This is a cross-sectional view of the internal structure of the protection box in the second embodiment; Fig.10 This is a schematic diagram of the locked state inside the protection box in the second embodiment.

[0015] In the figure: valve body 1, working shell 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 stem 12, spring 13 and, sliding sleeve 14, protection box 15, second sealing ring 16, drain pipe 17, connecting plate 18, rack 19, gear 20, support rod 21, first drain cover 22, first drain port 23, second drain cover 24, inclined surface 25, plug 26, second drain port 27, rotating shaft 28, valve plate 29, slider 30, toothed locking block 31, baffle 32. DETAILED DESCRIPTION

[0016] The following are specific embodiments of the present invention and the accompanying drawings to further describe the technical solution of the present invention, but the present invention is not limited to these embodiments.

[0017] In the description of the present invention, it should be noted that the terms "inside", "below", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship in which the product of the invention is usually placed when in use, which is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", etc. are only used to distinguish the description, and cannot be understood as indicating or implying relative importance.

[0018] Embodiment 1: Combined with Figure 1-8A self-locking backflow preventer includes a valve body 1, a working housing 2 is provided on 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 of the valve body 1, 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, a rotating shaft 28 is rotatably connected to the middle part of the first drain cover 22, a second drain cover 24 is connected to the rotating shaft 28, and the second drain cover 24 rotates relative to the first drain cover 22 to seal and pass water through the drain pipe 17. When in use, the plug 26 is opened to connect to the external drainage system.

[0019] Furthermore, 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 in front of the first check valve, and a third test valve 6 is provided on the valve body 1 in the rear of the second check valve.

[0020] Furthermore, the first check valve includes a first sealing ring 9 fixedly arranged on the valve body 1, and the first sealing ring 9 is connected to the 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 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 through a spring 13, a sliding sleeve 14 is slidably arranged outside the fixed sleeve 11, one end of the valve stem 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, and the valve plate 29 cooperates with the first sealing ring 9 to achieve sealing.

[0021] Furthermore, the second check valve includes a second sealing ring 16 fixedly arranged on the valve body 1 , and the second sealing ring 16 is connected to the valve body assembly.

[0022] Furthermore, 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.

[0023] 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 , and the rack 19 is meshed with the gear 20 for transmission.

[0024] Furthermore, a slope 25 is provided on one side of the second drain port 27. The design of the slope 25 enables the spiral force generated when the water flows down to give the rack 19 a driving force to move toward the first sealing ring 9.

[0025] Furthermore, two support rods 21 are fixedly arranged on the upper side of the drain pipe 17, and 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. The support form of the protection box 15 can be changed according to actual needs, and the shape of the water-facing surface of the protection box can also be changed to achieve the effect of reducing resistance.

[0026] During actual use of the present application, water flows in from the direction of the first check valve, and after reaching a certain water pressure, it pushes the valve plate 29 of the first check valve, compresses the spring 13, and the water flows through the first check valve into the space between the valve body 1 and the working shell 2. When the valve plate 29 of the first check valve 29 moves, the sliding sleeve 14 moves, driving the rack 19 to move, thereby driving the gear 20 to rotate, thereby driving the second drain cover 24 to rotate, so that the second drain outlet 27 is staggered with the first drain outlet 23 to achieve sealing.

[0027] After the water flow continues in the valve body 1, as the water pressure increases, the second check valve is pushed to open, thereby achieving water flow.

[0028] After the water flow is finished, the first check valve and the second check valve return to the initial position. At this time, the rack 19 drives the gear 20 to rotate, and drives the second drainage cover 24 to rotate, so that the second drainage port 27 is reconnected with the first drainage port 23 to achieve drainage, so that no water is stored in the valve body 1 when no water flows.

[0029] 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 existence of the inclined surface 25 will give the second drain cover 24 a rotation tendency, and this rotation tendency can make the rack 19 tend to move toward the first sealing ring 9, pressing the valve plate 29 of the first check valve against the first sealing ring 9, thereby realizing the self-locking of the backflow seal and preventing the return water from polluting the water source.

[0030] Embodiment 2: Combined with Fig. 9 , 10 On the basis of the first embodiment, the rack 19 is connected to the protection box 15 in a sliding and sealing manner through a sealing ring, the rotating shaft 28 is connected to the protection box 15 in a rotating and sealing manner through a sealing ring, and a slider 30 is provided in a sliding and sealing manner at one end of the protection box 15 away from the rack 19, and 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 to limit the slider 30.

[0031] The interior of the protection box 15 is completely sealed. When the backflow preventer works normally, the first check valve opens normally, and the rack 19 extends into the protection box 15. At this time, the water pressure inside the valve body 1 increases, and the pressure pushes the slider 30 to slide toward the inside of the sliding box 15, but it stops at the limit stop at the end of the rack 19.

[0032] If the second check valve returns water to the inside of the valve body 1, while the second drainage cover 24 is draining water, if the drainage rate cannot match the return water speed, the water pressure inside the valve body 1 will increase, pushing the slider 30 to move toward the gear 20, and the toothed locking block 31 will contact and lock with the gear 20, thereby locking the movement of the rack 19, so that when the degree of backflow is further aggravated, the first check valve is completely locked. When the backflow situation is handled, the water pressure inside the valve body 1 returns to normal, and the slider 30 is reset under the action of the internal air pressure to return to normal working state.

[0033] The above descriptions are merely embodiments of the present invention, and are not intended to limit the patent protection scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention's specification and drawings, or directly or indirectly applied in other related technical fields, are also 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 close the drain pipe (17) and allow water to flow.

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: The first check valve comprises a first sealing ring (9) fixedly arranged on a valve body (1), wherein the first sealing ring (9) is 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 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), a sliding sleeve (14) is slidably arranged outside the fixed sleeve (11), one end of the valve stem (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), and the valve plate (29) cooperates with the first sealing ring (9) to achieve sealing.

4. A self-locking backflow preventer according to claim 3, 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 3, characterized in that: 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.

6. A self-locking backflow preventer according to claim 5, characterized in that: 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.

7. A self-locking backflow preventer according to claim 5, characterized in that: A slope (25) is provided on one side of the second drain port (27).

8. A self-locking backflow preventer according to claim 6, 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.

9. A self-locking backflow preventer according to claim 8, 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