Anti-backflow device for mechanical drop-in flush valve
Patent Information
- Application Number
- CN202522626432.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-11
- Publication Date
- 2026-10-27
- Estimated Expiration
- 2035-12-11
AI Technical Summary
对于结构紧凑的机械式冲水阀，其进水口与控制阀直接连接，当市政供水管网因维修、爆管等原因突然停水或产生巨大负压时，马桶储水箱或便池中的污水存在被虹吸回灌至供水管网的风险，严重威胁公共饮水安全
1、本申请下落时机械冲水阀的防反流装置，包括储水箱、排水管、进水管以及控制活塞，水流从所述进水管进入所述控制活塞中，在控制活塞作用下排放至所述储水箱或者所述排水管；所述排水管的进水端位于所述储水箱的下部，所述排水管的出水端位于所述储水箱的中部，所述排水管中部设置有倒U部，所述倒U部延伸至所述储水箱顶部，所述倒U部顶端内部形成空气隔断部，所述空气隔断部最顶端设置有单向气阀，所述单向气阀仅允许外部空气往所述空气隔断部中补充；所述进水管与所述控制活塞连接处设置有真空破坏器。在排水管路上设置的倒U部，其顶端形成的空气隔断部，在物理上创造了一个不可逾越的屏障。即使控制活塞产生再强的虹吸力，也只能将倒U部顶端空气隔断部的水柱抽走。顶部的单向气阀是关键增强设计，它能确保在强虹吸作用下，空气隔断部内部压力下降时，外部空气能被迅速吸入，从而立即有效地破坏真空，确保空气隔断的绝对可靠性，彻底杜绝了通过排水路径发生反流的任何可能性。在进水管源头设置的真空破坏器，是防止供水管网负压导致反流的直接措施。当管网压力异常下降时，真空破坏器能迅速开启，吸入大气，平衡管道内部压力，从源头上切断虹吸效应的动力源，确保储水箱或便池中的水不会被吸回洁净供水管。
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Figure CN224902314U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of toilet technology, and in particular to an anti-backflow device for a mechanical flush valve when it falls. Background Technology
[0002] Mechanical flushing toilets, especially drop-down mechanical flush valves, are gaining popularity due to their more compact structure and more aesthetically pleasing appearance, as they eliminate the bulky float assembly of traditional float-type tanks. Their core principle is to control water storage and drainage using inlet water pressure and the stroke of a mechanical piston. According to national drinking water hygiene standards, sanitary ware must effectively prevent sewage from flowing back into the clean water supply network. Traditional float-type tanks prevent backflow through simple physical air gaps, but their structure occupies a large space. For compact mechanical flush valves, the inlet is directly connected to the control valve. When the municipal water supply network suddenly shuts off due to maintenance, pipe bursts, or other reasons, or experiences significant negative pressure, there is a risk that sewage in the toilet tank or bowl may be siphoned back into the water supply network, seriously threatening public drinking water safety. Furthermore, during flushing, improper drainage pipe design can cause the toilet water seal to dry out due to the siphon effect, losing its function of isolating sewer odors.
[0003] Existing mechanical flushing control valves rely on inlet water pressure and the stroke of a mechanical piston to control water storage and drainage, resulting in insufficient backflow prevention. Summary of the Invention
[0004] To address the aforementioned problems, this utility model aims to solve the problems described above. One objective of this utility model is to provide an anti-backflow device for a mechanical flushing valve during a fall, which solves one of the problems mentioned above.
[0005] The present invention provides a backflow prevention device for a mechanical flushing valve during descent, comprising a water storage tank, a drain pipe, an inlet pipe, and a control piston. Water flows from the inlet pipe into the control piston and is discharged to the water storage tank or the drain pipe under the action of the control piston. The inlet end of the drain pipe is located at the lower part of the water storage tank, and the outlet end of the drain pipe is located at the middle part of the water storage tank. An inverted U-shaped section is provided in the middle of the drain pipe, extending to the top of the water storage tank. An air gap is formed inside the top of the inverted U-shaped section, and a one-way air valve is provided at the top of the air gap, allowing only external air to be supplied to the air gap. A vacuum breaker is provided at the connection between the inlet pipe and the control piston.
[0006] A preferred technical solution is that the control piston sidewall is provided with a water inlet port, an extension pipe is provided between the water inlet port and the vacuum breaker, the vacuum breaker is located in the water storage tank, and the vacuum breaker is higher than half the height of the water storage tank.
[0007] A preferred technical solution is that the water storage tank is provided with a partition plate, the inverted U-shaped part spans the top of the partition plate, and the inlet and outlet ends of the drain pipe are distributed on both sides of the partition plate.
[0008] A preferred technical solution is that the water outlet end of the control piston is provided with a flow channel switching mechanism. The flow channel switching mechanism is provided with a first flow channel connected to the water storage tank and a second flow channel connected to the drain pipe. When flushing, the water storage tank is first filled with water through the first flow channel until the vacuum breaker is submerged, and then the water in the water storage tank is sucked away through the second flow channel.
[0009] A preferred technical solution is that a water outlet connector is provided between the second flow channel and the drain pipe. The water outlet connector is installed on the second flow channel. A jet nozzle is provided inside the water outlet connector. The diameter of the jet nozzle gradually decreases along the water outlet direction. A water replenishment channel is provided at the water outlet end of the jet nozzle. The water replenishment channel is connected to the water storage tank. The water outlet end of the water outlet connector is connected to the drain pipe.
[0010] A preferred technical solution is that a fixing pipe is provided at the bottom of the water outlet connector, and the bottom of the fixing pipe is fixedly connected to the water storage tank.
[0011] Compared with the prior art, the anti-backflow device of the mechanical flushing valve of this utility model has the following technical effects: 1. The anti-backflow device for the mechanical flushing valve during descent, as described in this application, includes a water storage tank, a drain pipe, an inlet pipe, and a control piston. Water flows into the control piston through the inlet pipe and is discharged into the water storage tank or the drain pipe under the action of the control piston. The inlet end of the drain pipe is located at the lower part of the water storage tank, and the outlet end of the drain pipe is located at the middle part of the water storage tank. An inverted U-shaped section is provided in the middle of the drain pipe, extending to the top of the water storage tank. An air gap is formed inside the top of the inverted U-shaped section, and a one-way air valve is provided at the top of the air gap, allowing only external air to be supplied to the air gap. A vacuum breaker is provided at the connection between the inlet pipe and the control piston. The inverted U-shaped section on the drain pipe, with its top forming an air gap, physically creates an insurmountable barrier. Even if the control piston generates a strong siphon force, it can only draw away the water column from the air gap at the top of the inverted U-shaped section. The one-way air valve at the top is a key enhanced design feature. It ensures that under strong siphon action, when the internal pressure of the air isolation section drops, outside air can be rapidly drawn in, thus immediately and effectively breaking the vacuum. This ensures the absolute reliability of the air isolation and completely eliminates any possibility of backflow through the drainage path. The vacuum breaker installed at the source of the water inlet pipe is a direct measure to prevent backflow caused by negative pressure in the water supply network. When the network pressure drops abnormally, the vacuum breaker opens quickly, drawing in atmospheric air to balance the internal pressure of the pipe, cutting off the power source of the siphon effect at its source, and ensuring that water in the storage tank or toilet bowl is not drawn back into the clean water supply pipe.
[0012] Other features and advantages of the present invention will become clear when reading the following description of exemplary embodiments with reference to the accompanying drawings. Attached Figure Description
[0013] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the present invention and, together with the description, serve to explain the principles of the present invention. In these drawings, similar reference numerals are used to denote similar elements. The drawings described below are some embodiments of the present invention, but not all embodiments. Other drawings will be readily available to those skilled in the art based on these drawings without any inventive effort.
[0014] Figure 1 This is a schematic diagram of the overall structure of the anti-backflow device of the mechanical flushing valve during falling, provided in a specific embodiment of this utility model.
[0015] In the picture: 1. Water storage tank; 3. Drain pipe; 4. Inlet pipe; 6. Control piston; 7. Flow channel switching mechanism; 8. Vacuum breaker; 11. Divider plate; 31. Inverted U-shaped section; 32. Air isolation section; 33. One-way air valve; 41. Inlet port; 42. Extension pipe; 701. First flow channel; 702. Second flow channel; 70. Outlet connector; 75. Jet nozzle; 76. Water replenishment channel; 78. Fixing pipe. Detailed Implementation
[0016] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this utility model. All other embodiments obtained by those skilled in the art based on the embodiments of this utility model without creative effort are within the scope of protection of this utility model. It should be noted that, unless otherwise specified, the embodiments and features in the embodiments of this application can be arbitrarily combined with each other.
[0017] The backflow prevention device of the mechanical flushing valve during descent is described in detail below with reference to the accompanying drawings and embodiments.
[0018] like Figure 1As shown, an anti-backflow device for a falling-type mechanical flush valve includes a water storage tank 1, a drain pipe 3, an inlet pipe 4, and a control piston 6. Water flows from the inlet pipe 4 into the control piston 6 and is discharged to the water storage tank 1 or the drain pipe 3 under the action of the control piston 6. The inlet end of the drain pipe 3 is located at the lower part of the water storage tank 1, and the outlet end of the drain pipe 3 is located at the middle part of the water storage tank 1. An inverted U-shaped section 31 is provided in the middle of the drain pipe 3, extending to the top of the water storage tank 1. An air isolation section 32 is formed inside the top of the inverted U-shaped section 31, and a one-way air valve 33 is provided at the top of the air isolation section 32, allowing only external air to be supplied to the air isolation section 32. A vacuum breaker 8 is provided at the connection between the inlet pipe 4 and the control piston 6. The working process begins at the inlet pipe 4, and the water flow is distributed by the control piston 6, either entering the water storage tank 1 for energy storage or directly entering the drain pipe 3. Its core anti-backflow structure consists of two points: First, physical isolation of the drainage path. The drain pipe 3 passes through the inside of the water storage tank 1, forming an inverted U-shaped bend with its top higher than the highest water level in the tank 1. The top of this inverted U-shaped bend 31 constitutes an air isolation section 32 that always contains air. According to the principles of fluid mechanics, the siphon effect requires a continuous liquid column. This air isolation section 32 physically interrupts the continuous liquid column that may form between the toilet bowl and the outlet of the drain pipe 3, preventing the siphon effect from being established. The one-way air valve 33 at the top acts as an enhanced defense. When the pressure inside the air isolation section 32 drops slightly due to abnormal conditions, the external atmospheric pressure will open the valve disc of the one-way air valve 33, instantly replenishing air, thereby actively and positively destroying any possible vacuum state and ensuring the absolute reliability of the air isolation. Second, pressure balance of the water inlet path. A vacuum breaker 8 is installed at the source of the water inlet pipe 4 to prevent the risk of a sudden drop in water supply network pressure. When negative pressure occurs in the pipe network, the sealing mechanism inside the vacuum breaker 8 automatically opens under the pressure difference, introducing atmospheric air into the pipe and rapidly restoring the internal pressure to atmospheric pressure, thus fundamentally eliminating the driving force behind siphon backflow. This design forms a dual safety protection system combining the vacuum breaker 8 and the air isolation section 32. Working together, they block all possible backflow paths from the system's inlet and outlet, respectively, achieving an extremely high level of safety that fully complies with and exceeds the most stringent drinking water safety regulations. This redundant design ensures that even if one fails unexpectedly, the other can still provide effective protection.
[0019] The vacuum breaker 8 features an optimized high-position layout. A water inlet port 41 is located on the side wall of the control piston 6, and an extension pipe 42 connects the water inlet port 41 to the vacuum breaker 8. The vacuum breaker 8 is situated within the water storage tank 1, extending above half the height of the tank. The air inlet of the vacuum breaker 8 is extended and fixed to the upper half of the inner wall of the water storage tank 1 via the extension pipe 42. This installation position ensures that the air inlet of the vacuum breaker 8 is always exposed to air at the normal water level in the water storage tank 1, preventing it from being submerged. This high-position installation offers multiple benefits. First, it prevents the air inlet from being submerged when the tank is filled with water, avoiding impurities clogging the air intake channel or causing mechanical failure due to prolonged immersion, ensuring the vacuum breaker 8 is always in optimal standby condition. Second, the internal environment of the water tank is more stable than the external environment, reducing dust contamination, ensuring the cleanliness of the intake air, and improving the lifespan and reliability of the device.
[0020] The internal partitioning and flow field optimization scheme of the water tank involves a partition plate 11 installed in the water storage tank 1. The inverted U-shaped section 31 spans the top of the partition plate 11, and the inlet and outlet ends of the drain pipe 3 are distributed on both sides of the partition plate 11. A vertical partition plate 11 divides the interior of the water storage tank 1 into two connected chambers. The inlet end of the drain pipe 3 is located at the bottom of one chamber, while the outlet end is located in the other chamber. The highest point of the inverted U-shape crosses over the partition plate 11 from above, connecting the two chambers. The partition plate 11 greatly optimizes the hydraulic flow field inside the water tank. It forces the water flow to pass over the top of the inverted U-shaped section 31, which effectively strengthens the physical barrier effect of the air gap section 32. More importantly, it prevents water flowing back from the drain pipe 3 from being directly sucked back into the drain pipe 3 without effective utilization, forming a more reasonable loop. This allows the water stored in the water storage tank 1 to be used more fully and efficiently for flushing, improving flushing kinetic energy and efficiency.
[0021] The intelligent flushing sequence and system self-maintenance feature include a flow channel switching mechanism 7 at the outlet of the control piston 6. This mechanism has a first flow channel 701 connected to the water storage tank 1 and a second flow channel 702 connected to the drain pipe 3. During flushing, water is first pumped into the water storage tank 1 through the first flow channel 701 until it submerges the vacuum breaker 8. Then, the water in the water storage tank 1 is drained through the second flow channel 702. This design integrates anti-backflow logic into the flushing process itself. When the user triggers flushing, the flow channel switching mechanism 7 first directs the water flow to the first flow channel 701, filling the water storage tank 1. Once the water level reaches the predetermined level, the flow channel switching mechanism 7 automatically switches the water path to the second flow channel 702, initiating the drainage phase. This sequence of storing water first and then draining it not only achieves water conservation by utilizing stored water for high-flow flushing, but also cleverly provides passive maintenance for the vacuum breaker 8, ensuring its automatic reset after each flushing cycle without user intervention, thus greatly improving the system's long-term reliability. The entire process is completed automatically by the mechanical structure, making it intelligent and efficient.
[0022] The core of the jet-effect enhancement and water-saving design is a water outlet connector 70 located between the second flow channel 702 and the drain pipe 3. The water outlet connector 70 is installed on the second flow channel 702 and contains a jet nozzle 75. The diameter of the jet nozzle 75 gradually decreases along the water outlet direction. A water replenishment channel 76 is located at the outlet end of the jet nozzle 75, and the water replenishment channel 76 is connected to the water storage tank 1. The outlet end of the water outlet connector 70 is connected to the drain pipe 3. The jet nozzle 75 inside the water outlet connector 70 is a precision Venturi tube. When high-pressure water flows from the control piston 6 through the second flow channel 702 into the jet nozzle 75, the water velocity increases sharply due to the gradually decreasing cross-sectional area of the flow channel. According to Bernoulli's principle, the dynamic pressure increases while the static pressure decreases, forming a strong low-pressure zone at the narrowest throat of the jet nozzle 75. This negative pressure, through the water supply channel 76, generates a powerful suction force, efficiently drawing the pre-stored water in the water storage tank 1 into the water outlet 70, where it mixes with the raw water flow from the water inlet pipe 4 and is sprayed at high speed into the drain pipe 3. This is the core of this solution's high-efficiency water saving. The system utilizes a small stream of high-pressure water, through a jet effect, to draw in and drive a larger flow of water from the water storage tank 1 to participate in the flushing, achieving a doubling of the flow rate. Ultimately, the system achieves the flushing effect that traditional high-flow-rate flushing requires with a smaller inlet flow rate, significantly improving water saving. Simultaneously, the high-speed water flow also brings stronger flushing force, resulting in better cleaning.
[0023] The bottom of the water outlet connector 70 is provided with a fixing pipe 78, the bottom of which is fixedly connected to the water storage tank 1. The water outlet connector 70 is not only connected to the second flow channel 702 through its inlet, but its bottom is also mechanically fixed to the bottom or side wall of the water storage tank 1 through a fixing pipe 78. This fixing pipe 78 can be in the form of a support leg, or it can be a hollow pipe that also serves as a water supply channel 76. The jet effect will generate a certain amount of vibration and recoil. The setting of the fixing pipe 78 transforms the water outlet connector 70 from a cantilever beam structure into a stable structure supported at both ends. This effectively suppresses vibration, prevents loosening, leakage, or positional displacement of the connection due to long-term shaking, and ensures that the relative position between the jet nozzle 75 and the water supply channel 76 remains accurate, thereby guaranteeing the long-term stability of the suction efficiency and the quiet operation of the system.
[0024] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that an article or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such an article or apparatus. Without further limitations, an element defined by the phrase "comprising..." does not exclude the presence of other identical elements in the article or apparatus that includes that element.
[0025] The above embodiments are only used to illustrate the technical solution of this utility model and are not intended to limit it. The utility model has been described in detail with reference to preferred embodiments. Those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solution of this utility model without departing from the spirit and scope of the technical solution of this utility model, and all such modifications and substitutions should be covered within the scope of the claims of this utility model.
Claims
1. A backflow prevention device for a mechanical flushing valve during descent, characterized in that: It includes a water storage tank, a drain pipe, a water inlet pipe, and a control piston. Water flows from the water inlet pipe into the control piston and is discharged to the water storage tank or the drain pipe under the action of the control piston. The inlet of the drain pipe is located at the bottom of the water storage tank, and the outlet of the drain pipe is located in the middle of the water storage tank. An inverted U-shaped section is provided in the middle of the drain pipe, which extends to the top of the water storage tank. An air gap is formed inside the top of the inverted U-shaped section, and a one-way air valve is provided at the top of the air gap. The one-way air valve only allows external air to be supplied to the air gap. A vacuum breaker is installed at the connection between the water inlet pipe and the control piston.
2. The anti-backflow device for the mechanical flushing valve during descent as described in claim 1, characterized in that: The control piston has a water inlet port on its side wall, and an extension pipe is provided between the water inlet port and the vacuum breaker. The vacuum breaker is located in the water tank and is higher than half the height of the water tank.
3. The anti-backflow device for the mechanical flushing valve during descent as described in claim 1, characterized in that: The water storage tank is equipped with a partition plate, the inverted U-shaped section spans the top of the partition plate, and the inlet and outlet ends of the drain pipe are distributed on both sides of the partition plate.
4. The anti-backflow device for the mechanical flushing valve during descent as described in claim 1, characterized in that: The water outlet end of the control piston is provided with a flow channel switching mechanism. The flow channel switching mechanism is provided with a first flow channel connected to the water storage tank and a second flow channel connected to the drain pipe. When flushing, the water storage tank is first filled with water through the first flow channel until the vacuum breaker is submerged, and then the water in the water storage tank is sucked away through the second flow channel.
5. The anti-backflow device for the mechanical flushing valve during descent as described in claim 4, characterized in that: A water outlet connector is provided between the second flow channel and the drain pipe. The water outlet connector is installed on the second flow channel. A jet nozzle is provided inside the water outlet connector. The diameter of the jet nozzle gradually decreases along the water outlet direction. A water replenishment channel is provided at the water outlet end of the jet nozzle. The water replenishment channel is connected to the water storage tank. The water outlet end of the water outlet connector is connected to the drain pipe.
6. The anti-backflow device for the mechanical flushing valve during descent as described in claim 5, characterized in that: The bottom of the water outlet connector is provided with a fixing pipe, and the bottom of the fixing pipe is fixedly connected to the water storage tank.