Filter bottle upper installation type backwash prefilter

CN224777538UActive Publication Date: 2026-09-22HAINING BEISHI ENVIRONMENTAL PROTECTION SCI & TECH CO LTD
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Patent Information

Application Number
CN202521945388.2
Authority / Receiving Office
CN · China
Patent Type
Utility models(China)
Current Assignee / Owner
Filing Date
2025-09-10
Publication Date
2026-09-22
Estimated Expiration
2035-09-10

AI Technical Summary

Technical Problem

有些安装场合,该种滤瓶下置式前置过滤器安装不方便,为此,滤瓶上置式的前置过滤器应市场需求而生,该种前置过滤器的阀头,除了设置入水口、出水口和滤瓶安装口外,还需要设置排污口,也即将原设置于滤瓶下端的排水球阀的功能要转设于阀头,因此需要对传统反冲洗轴向调节结构做优化调整

Benefits of technology

[0021]优选的,所述驱动元件为手动驱动元件和/或电动驱动元件。实现手动、自动或者手自一体的流道切换组件的驱动旋转,提高产品的应用场景。

✦ Generated by Eureka AI based on patent content.

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Abstract

The utility model relates to a filter bottle upper -placed backwash prefilter, including valve shell, filter and backwash mechanism and filter bottle, the valve shell is equipped with raw water end, clean water end, the filter bottle assembly end that faces upwards, the sewage end that faces downwards and valve shell cavity, the sewage end is equipped with sewage assembly, and the filter bottle is fixed with filter bottle assembly end cooperation, and the filter and backwash mechanism are equipped in the filter bottle, and the cavity between filter mechanism and filter bottle constitutes raw water chamber, and the inside constitution of filter mechanism constitutes purified water chamber, the filter and backwash mechanism include the filter mechanism and backwash mechanism of coaxial arrangement, and the filter mechanism includes filter screen and filter framework, and the backwash mechanism includes backwash filter screen and backwash framework, be equipped with flow channel switching assembly in the valve shell cavity. The structure is more optimal, and the filter bottle upper -placed backwash prefilter of easy matching installation occasion can realize the switching of three kinds of states of filter, sewage and backwash sewage, and solves the problem of backwash framework axial movement failure.
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Description

Technical Field

[0001] This utility model relates to a top-mounted backwashing pre-filter, belonging to the technical field of water purification equipment. Background Technology

[0002] The mainstream pre-filters in the current technology are of the bottom-mounted filter bottle type, including: a head unit, a filter bottle connected to the head unit at the top, and a drain ball valve connected to the bottom of the filter bottle. A filter screen frame is installed inside the filter bottle, and a filter screen is fitted onto the outer wall of the filter screen frame. During use, water flows from the inlet of the head unit into the gap between the filter bottle and the filter screen, is filtered by the filter screen, flows into the center of the filter screen frame, and then flows from the center of the filter screen frame to the outlet of the head unit. When drainage is needed, the drain ball valve at the bottom of the filter bottle is opened. In some installation scenarios, this type of bottom-mounted filter bottle pre-filter is inconvenient to install. Therefore, the top-mounted filter bottle pre-filter has emerged to meet market demand. In this type of pre-filter, in addition to the inlet, outlet, and filter bottle mounting port, the valve head also needs to be equipped with a drain port. That is, the function of the drain ball valve originally located at the bottom of the filter bottle is transferred to the valve head. Therefore, it is necessary to optimize and adjust the traditional backwashing axial adjustment structure. In addition, the pre-filters in the existing technology have a combined function of filtration and backwashing. During backwashing, the backwashing frame is moved axially by using the principle of pressure difference. This method also has certain drawbacks, namely, it is prone to failure.

[0003] This utility model aims to provide a top-mounted backwash pre-filter with a more optimized structure that is easy to match with installation occasions. It can switch between three states: filtration, sewage discharge, and backwash sewage discharge, and solves the problem of axial movement failure of the backwash frame. Utility Model Content

[0004] One of the purposes of this utility model is to address the shortcomings of existing pre-filters and provide a top-mounted backwashing pre-filter with a more optimized structure that is easy to match with different installation environments. It can switch between three states: filtration, sewage discharge, and backwashing sewage discharge, and solves the problem of axial movement failure of the backwashing frame.

[0005] The technical solution adopted by this utility model to solve its technical problem is:

[0006] A top-mounted backwashing pre-filter includes a valve housing, a filtration and backwashing mechanism, and a filter bottle. The valve housing has a raw water end, a clean water end, an upward-facing filter bottle assembly end, a downward-facing drain end, and a valve housing cavity. The drain end is equipped with a drain assembly. The filter bottle is fixedly fitted to the filter bottle assembly end. The filtration and backwashing mechanism is located inside the filter bottle. The cavity between the filtration mechanism and the filter bottle forms the raw water cavity, and the interior of the filtration mechanism forms the clean water cavity. The filtration and backwashing mechanism includes a coaxially arranged filtration mechanism and a backwashing mechanism. The filtration mechanism includes a filter screen and a filter frame, and the backwashing mechanism includes a backwashing filter screen and a backwashing frame. A flow channel switching component is provided inside the valve housing cavity. The flow channel switching component has a raw water flow channel, a clean water flow channel, a drain flow channel, and a backwashing water flow channel. The flow channel switching component is circumferentially rotatably sealed to the valve housing cavity or axially slidingly sealed. The flow channel switching component rotates under external force to switch between the filtration mode and the backwashing drain mode.

[0007] The flow channel switching assembly is equipped with a rotating lifting mechanism, which can cooperate with the backwash frame. During the rotation of the rotating lifting mechanism and the flow channel switching assembly, the backwash frame is raised or lowered relative to the filter frame, thereby opening or closing the backwash filter.

[0008] Preferably, the rotating lifting mechanism includes a fixed part, a rotating shaft part, and a guide rail part with an inclination. The fixed part is fixed to the flow channel switching component or valve housing, and the rotating shaft part is rotatably connected to the backwash frame. The end of the backwash frame is also provided with a matching guide. The axial adjustment of the backwash frame is realized by the cooperation between the guide and the guide rail part.

[0009] Preferably, the guide rail is arranged in a continuous arc shape along the circumference of the rotating lifting mechanism, and the height from the lowest point to the highest point of the guide rail is consistent with the maximum stroke of the backwash frame axial adjustment.

[0010] Preferably, a limiting part is also provided at the end of the guide rail, wherein the limiting part is a limiting protrusion and / or an arc-shaped limiting groove.

[0011] Preferably, the flow channel switching component rotates under external force, which can close the raw water flow channel and / or the purified water flow channel, and open the backwash water flow channel, switching to the backwash mode; or it can open the raw water flow channel and the purified water flow channel, and close the backwash water flow channel, switching to the filtration mode.

[0012] Preferably, the flow channel switching component rotates 30-180° under external force to switch to backwash mode; the flow channel switching component rotates to the same angle in the opposite direction under external force to switch to filtration mode.

[0013] This invention not only adds an inlet, outlet, and filter bottle mounting port to the valve head, but also a drain port. This effectively relocates the function of the drain ball valve, originally located at the bottom of the filter bottle, to the valve head, thus optimizing the traditional backwashing axial adjustment structure. Specifically, during filtration, the rotation of the flow channel switching component connects the raw water end to the raw water channel and the purified water channel to the purified water end. When wastewater discharge is required, rotating the flow channel switching component closes the raw water channel and / or the purified water channel, and opening the drain valve. When backwashing is required, the backwash water channel is connected to the raw water channel to flush away accumulated impurities on the valve head, which are then discharged through the drain valve.

[0014] Preferably, the filter bottle assembly end is provided with a quick-release structure for assembling the filter bottle. The quick-release structure is detachable and includes a screw-in structure and a snap-fit ​​structure. This quick-release structure facilitates user installation, filter bottle replacement and maintenance, and also allows for easy disassembly and cleaning when impurities remain and cause blockage inside the valve head.

[0015] Preferably, the valve housing cavity is provided with at least one limiting part A, and the flow channel switching assembly is provided with at least one matching limiting part B. Through the cooperation of limiting parts A and B, circumferential limiting or synchronous circumferential and axial limiting of the flow channel switching assembly is achieved. The simple cooperation of limiting parts A and B achieves circumferential limiting or synchronous circumferential and axial limiting, avoiding axial misalignment during circumferential rotation of the flow channel switching assembly, and facilitating the determination of the target position for circumferential rotation.

[0016] More preferably, a limiting part A is provided at the upper and lower parts of the valve housing cavity, and the flow channel switching component is provided with two corresponding matching limiting parts B. Through the double cooperation of the upper and lower limiting parts A and the limiting parts B, the flow channel switching component is doubly limited. The simple cooperation of the double limiting parts A and B achieves double limiting, avoiding axial misalignment when the flow channel switching component rotates circumferentially, and making it easy to determine the target position of circumferential rotation, further improving the reliability of valve head flow channel switching.

[0017] Preferably, the limiting part A is a groove or a protrusion structure, and the limiting part B is a protrusion or a groove structure. This type of limiting structure is easy to process, easy to demold, and has high limiting reliability.

[0018] Preferably, the flow channel switching assembly is equipped with a rotation drive component, which is a drive element that extends axially upward along the filter bottle to the bottom of the filter bottle and is rotatably and sealingly connected. The rotation of the drive element drives the flow channel switching assembly, or the flow channel switching assembly is linked with the drain assembly, and the drain assembly is rotatably and sealingly connected to the drain end, so that the rotation of the drain assembly realizes the rotation of the flow channel switching assembly. This utility model designs two different rotation drive components, which respectively realize driving from the top of the filter bottle or from the drain end. The specific choice can be made according to the needs during processing. Both can effectively drive the flow channel switching assembly, better realize the flow channel switching function of the valve head, and have excellent practical performance.

[0019] Preferably, the rotation drive is a drive element extending upward along the filter bottle axis, including a drive handle and a drive rod, one end of the drive rod being fixed to the flow channel switching component and the other end being fixed to the drive handle; or the drive element includes a drive handle and a drive frame, with both ends of the drive frame being directly or indirectly fixed to the flow channel switching component and the drive handle, respectively; or the drive element includes a drive handle, with the frame of the filter mechanism serving as the drive frame, and both ends of the frame of the filter mechanism being fixed to the drive handle and the flow channel switching component, respectively.

[0020] Preferably, the sewage discharge component is linked to the flow channel switching component, and the sewage discharge component includes a sewage discharge seal and a sewage discharge valve. The sewage discharge seal is rotatably and sealingly connected to the sewage discharge end, and the sewage discharge valve is fixedly connected to the sewage discharge seal.

[0021] Preferably, the driving element is a manual driving element and / or an electric driving element. This enables the manual, automatic, or manual-automatic combined flow channel switching component to rotate, expanding the product's application scenarios.

[0022] Preferably, a sealing element is provided between the flow channel switching component and the valve housing cavity, and a rotational sealing connection is achieved through the cooperation of the sealing element.

[0023] The beneficial effects of this utility model are: 1) In addition to setting an inlet, outlet and filter bottle installation port on the valve head, this utility model also sets a drain port, which means that the function of the drain ball valve originally set at the lower end of the filter bottle is transferred to the valve head, effectively optimizing and adjusting the traditional backwashing axial adjustment structure. Specifically, during filtration, the flow channel switching component rotates to connect the raw water end with the raw water channel and the purified water channel with the purified water end. When sewage discharge is required, the flow channel switching component is rotated to close the raw water channel and / or the purified water channel, and the sewage discharge valve is opened. 2) Through the cooperation of simple limiting parts A and B, circumferential limiting or circumferential and axial synchronous limiting is used to avoid axial misalignment when the flow channel switching component rotates circumferentially, and the target position of circumferential rotation can be easily determined. 3) This utility model designs two different rotating drive components, which can be driven from the top of the filter bottle or from the sewage discharge end, respectively. The specific processing can be selected according to the needs. Both can effectively drive the flow channel switching component and better realize the flow channel switching function of the valve head, with excellent practical performance. 3) Through the cooperation of the guide rail and the guide component, the external force drives the axial adjustment of the backwash frame, overcoming the failure of the pressure difference principle in the prior art. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0025] Figure 1 This is a schematic diagram of the structure of this utility model;

[0026] Figure 2 This is a schematic diagram of the structure of this utility model;

[0027] Figure 3 yes Figure 1 A sectional view;

[0028] Figure 4 yes Figure 1 A sectional view;

[0029] Figure 5 yes Figure 1 A cross-sectional view (with the raw water channel and the purified water channel open);

[0030] Figure 6 yes Figure 1 A cross-sectional view (with the raw water channel and purified water channel closed);

[0031] Figure 7This is a schematic diagram of the structure of this utility model. In the figure: 1. Valve shell, 11. Water inlet end, 12. Water outlet end, 13. Filter bottle assembly end, 14. Sewage discharge end, 15. Valve shell cavity, 2. Flow channel switching component, 21. Raw water flow channel, 22. Clean water flow channel, 23. Sewage discharge flow channel, 24. Backwash water flow channel, 3. Limiting part A, 4. Limiting part B, 5. Sewage discharge seal, 6. Sewage discharge valve, 7. Guide rail part, 71. Fixing part, 72. Rotating part, 73. Guide rail part, 74. Limiting part, 8. Guide component, 9. Drive handle. Detailed Implementation

[0032] The embodiments of this utility model are described in detail below. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this utility model, and should not be construed as limiting this utility model.

[0033] In the description of this utility model, it should be understood that the directional descriptions, such as up, down, front, back, left, right, etc., indicate the directional or positional relationship based on the directional or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and 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 this utility model.

[0034] In the description of this utility model, the use of "first" and "second" is only for the purpose of distinguishing technical features and should not be construed as indicating or implying relative importance or implicitly indicating the number of technical features or the order of the technical features.

[0035] In the description of this utility model, unless otherwise explicitly defined, terms such as "setting," "installation," and "connection" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this utility model in conjunction with the specific content of the technical solution.

[0036] Example 1

[0037] like Figure 1-7As shown, the top-mounted backwashing pre-filter includes a valve housing 1, a filtration and backwashing mechanism, and a filter bottle. The valve housing 1 has a raw water end 11, a clean water end 12, an upward-facing filter bottle assembly end 13, a downward-facing drain end 14, and a valve housing cavity 15. The drain end 14 is equipped with a drain assembly. The filter bottle is fixedly fitted to the filter bottle assembly end. The filtration and backwashing mechanism is located inside the filter bottle. The cavity between the filtration mechanism and the filter bottle forms the raw water cavity, and the interior of the filtration mechanism forms the clean water cavity. The filtration and backwashing mechanism includes a coaxially arranged filtration mechanism and a backwashing mechanism. The filtration mechanism includes a filter screen and a filter filter. The filter frame and backwashing mechanism include a backwashing filter screen and a backwashing frame. The valve housing cavity 15 is provided with a flow channel switching component 2. The flow channel switching component 2 is provided with a raw water flow channel 21 corresponding to the raw water end 11, a purified water flow channel 22 corresponding to the filter bottle assembly end 13 and the purified water end 12, and a sewage discharge flow channel corresponding to the sewage discharge end 14. A backwashing water flow channel 24 is also provided between the raw water flow channel 21 and the purified water flow channel 22. The flow channel switching component 2 is rotatably and sealingly connected to the valve housing cavity 15. When the flow channel switching component 2 rotates under the action of external force, the flow channel switching between filtration and backwashing modes is realized.

[0038] The flow channel switching component 2 is fixedly equipped with a rotating lifting mechanism 7. The rotating lifting mechanism 7 can cooperate with the backwash frame. During the rotation of the rotating lifting mechanism 7 with the flow channel switching component 2, the backwash frame is raised or lowered relative to the filter frame, thereby opening or closing the backwash filter.

[0039] Specifically, the rotating lifting mechanism 7 includes a fixed part 71, a rotating shaft part 72, and a guide rail part 73 with an inclination. The fixed part 71 is fixed to the flow channel switching assembly 2, and the rotating shaft part 72 is rotatably connected to the backwash frame. The end of the backwash frame is also provided with a matching guide 8. The axial adjustment of the backwash frame is realized through the cooperation of the guide 8 and the guide rail part 73.

[0040] Specifically, the guide rail 73 is arranged in a continuous arc shape along the circumference of the rotating lifting mechanism 7, and the height from the lowest point to the highest point of the guide rail 73 is consistent with the maximum stroke of the backwash frame axial adjustment. A limiting part 74 is also provided at the end of the guide rail 73, which is a limiting protrusion and / or an arc-shaped limiting groove.

[0041] Specifically, the flow channel switching component 2 rotates under the action of external force, which can close the raw water flow channel 21 and / or the purified water flow channel 22 (closing both simultaneously or closing either one is sufficient), open the drain valve 6, and enter the drain mode. It can also open the backwash water flow channel 24 at the same time and switch to the backwash drain mode; it can also open the raw water flow channel 21 and the purified water flow channel 22 and close the backwash water flow channel 24 to switch to the filtration mode.

[0042] In addition, the axial sliding seal connection between the flow channel switching component 2 and the valve housing cavity 15 can also be achieved, and those skilled in the art can make the choice as needed.

[0043] As a specific implementation, the flow channel switching component 2 rotates 30-180° under the action of external force, such as 30°, 45°, 60°, 90°, 120°, 180°, and in this embodiment, 45° is selected to switch to the backwashing mode; the flow channel switching component 2 rotates in the opposite direction to reset under the action of external force by the same angle (45° in this embodiment) to switch to the filtration mode.

[0044] This invention not only adds an inlet, outlet, and filter bottle mounting port to the valve head, but also a drain port. This effectively optimizes the traditional backwashing axial adjustment structure by transferring the function of the drain ball valve, originally located at the bottom of the filter bottle, to the valve head. Specifically, during filtration, the rotation of the flow channel switching component 2 connects the raw water end 11 with the raw water flow channel 21, and connects the purified water flow channel 22 with the clean water end 12. When draining is required, rotating the flow channel switching component 2 closes the raw water flow channel 21 and / or the purified water flow channel 22, and opens the drain valve. When backwashing is required, the backwash water flow channel 24 is connected to the raw water flow channel 21 to flush away impurities accumulated in the valve head, which are then discharged through the drain valve 6.

[0045] In this embodiment, the filter bottle assembly end 13 is provided with a quick-installation structure for assembling the filter bottle. The quick-installation structure is detachable and includes a screw-in structure and a snap-fit ​​structure. This quick-installation structure facilitates user installation, filter bottle replacement and maintenance, and also allows for easy disassembly and cleaning when impurities remain and cause blockage inside the valve head.

[0046] Specifically, the valve housing cavity 15 is provided with at least one limiting part A3, and the flow channel switching assembly 2 is provided with at least one matching limiting part B4. Through the cooperation of limiting parts A3 and B4, circumferential limiting or synchronous circumferential and axial limiting of the flow channel switching assembly 2 is achieved. Circumferential limiting or synchronous circumferential and axial limiting is achieved through the simple cooperation of limiting parts A and B, avoiding axial misalignment when the flow channel switching assembly 2 rotates circumferentially, and making it easy to determine the target position of circumferential rotation.

[0047] More specifically, as a better alternative, the valve housing cavity 15 is provided with a limiting part A3 at the top and bottom, and the flow channel switching assembly 2 is provided with two corresponding matching limiting parts B4. Through the double cooperation of the upper and lower limiting parts A3 and the limiting parts B4, the flow channel switching assembly 2 is dually axially limited. The dual limiting is achieved through the simple cooperation of the double limiting parts A and B, which avoids axial misalignment when the flow channel switching assembly 2 rotates circumferentially, and makes it easy to determine the target position of circumferential rotation, further improving the reliability of valve head flow channel switching.

[0048] In this embodiment, the limiting part A3 is a groove or protrusion structure, and the limiting part B4 is a protrusion or groove structure. This type of limiting structure is easy to mold, easy to demold, and has high limiting reliability. The flow channel switching assembly 2 is equipped with a rotation drive component, which is a drive element that extends axially upwards along the filter bottle to the bottom of the filter bottle and is rotatably and sealingly connected. The rotation of the drive element drives the flow channel switching assembly 2, or the flow channel switching assembly 2 is linked with the drain assembly, and the drain assembly is rotatably and sealingly connected to the drain end 14. The rotation of the drain assembly realizes the rotation of the flow channel switching assembly 2. This utility model designs two different rotation drive components, respectively realizing driving from the top of the filter bottle or from the drain end. The appropriate component can be selected according to needs during processing. Both can effectively drive the flow channel switching assembly, better realize the flow channel switching function of the valve head, and have excellent practical performance.

[0049] Specifically, a preferred embodiment is as follows: the rotating drive component is a drive element extending upward along the filter bottle axis, including a drive handle 9 and a drive rod, one end of the drive rod being fixed to the flow channel switching component 2 and the other end being fixed to the drive handle 9; or the drive element includes a drive handle 9 and a drive frame, with both ends of the drive frame being directly or indirectly fixed to the flow channel switching component 2 and the drive handle 9 respectively; or the drive element includes a drive handle 7, with the frame of the filter mechanism serving as the drive frame, and both ends of the frame of the filter mechanism being fixed to the drive handle 9 and the flow channel switching component 2 respectively.

[0050] As a parallel implementation method, the flow channel switching component 2 is linked with the sewage discharge component. The sewage discharge component includes a sewage discharge seal 5 and a sewage discharge valve 6. The sewage discharge seal 5 is rotatably and sealingly connected to the sewage discharge end 14, and the sewage discharge valve 6 is fixedly connected to the sewage discharge seal 5. The driving element is a manual driving element and / or an electric driving element. This enables the flow channel switching component 2 to be driven and rotated manually, automatically, or in a combined manual and automatic mode, improving the application scenarios of the product. A sealing element is provided between the flow channel switching component 2 and the valve housing cavity 15, and a rotatable and sealing connection is achieved through the cooperation of the sealing element.

[0051] The beneficial effects of this utility model are: 1) In addition to setting an inlet, outlet and filter bottle installation port on the valve head, this utility model also sets a drain port, which means that the function of the drain ball valve originally set at the lower end of the filter bottle is transferred to the valve head, effectively optimizing and adjusting the traditional backwashing axial adjustment structure. Specifically, during filtration, the rotation of the flow channel switching component connects the raw water end and the raw water channel, and connects the purified water channel and the purified water end. When sewage discharge is required, the flow channel switching component is rotated to close the raw water channel and / or the purified water channel, and the sewage discharge valve is opened. 2) The simple cooperation of the limiting parts A and B achieves circumferential limiting or circumferential and axial synchronous limiting, avoiding axial misalignment when the flow channel switching component rotates circumferentially, and making it easy to determine the target position of circumferential rotation. 3) This utility model designs two different rotating drive components, which respectively realize driving from the top of the filter bottle or from the sewage discharge end. The specific processing can be selected according to the needs. Both can effectively drive the flow channel switching component and better realize the flow channel switching function of the valve head, with excellent practical performance. 3) Through the cooperation of the guide rail and the guide component, the external force drives the axial adjustment of the backwash frame, overcoming the failure of the pressure difference principle in the prior art.

[0052] The embodiments described above are merely preferred solutions of this utility model and are not intended to limit this utility model in any way. Other variations and modifications are possible without departing from the technical solutions described in the claims.

Claims

1. A pre-filter with a top-mounted backwashing filter, comprising a valve housing (1), a filtration and backwashing mechanism, and a filter bottle, wherein the valve housing (1) is provided with a raw water end (11), a clean water end (12), an upward-facing filter bottle assembly end (13), a downward-facing drain end (14), and a valve housing cavity (15), the drain end (14) is provided with a drain assembly, the filter bottle is fixedly fitted to the filter bottle assembly end (13), the filtration and backwashing mechanism is located inside the filter bottle, the cavity between the filtration mechanism and the filter bottle constitutes the raw water cavity, and the interior of the filtration mechanism constitutes the purified water cavity, wherein the filtration and backwashing mechanism includes a filtration mechanism and a backwashing mechanism arranged coaxially, the filtration mechanism includes a filter screen and a filter frame, and the backwashing mechanism includes a backwashing filter screen and a backwashing frame, characterized in that: The valve housing cavity (15) is provided with a flow channel switching assembly (2). The flow channel switching assembly (2) is provided with a raw water flow channel (21), a purified water flow channel (22), a sewage discharge flow channel (23) and a backwash water flow channel (24). The flow channel switching assembly (2) is circumferentially rotated and sealed or axially slidably sealed with the valve housing cavity (15). The flow channel switching assembly (2) rotates under the action of external force to realize the flow channel switching between the filtration mode and the backwash sewage discharge mode. The flow channel switching component (2) is fixedly provided with a rotating lifting mechanism (7). The rotating lifting mechanism (7) can cooperate with the backwash frame. During the rotation of the rotating lifting mechanism (7) and the flow channel switching component (2), the backwash frame is raised or lowered relative to the filter frame, thereby opening or closing the backwash filter.

2. The top-mounted backwashing pre-filter according to claim 1, characterized in that: The rotating lifting mechanism (7) includes a fixed part (71), a rotating shaft part (72), and a guide rail part (73) with an inclination. The fixed part (71) is fixed to the flow channel switching assembly (2) or the valve shell (1). The rotating shaft part (72) is rotatably connected to the backwash frame. The end of the backwash frame is also provided with a matching guide (8). The axial adjustment of the backwash frame is realized through the cooperation between the guide (8) and the guide rail part (73).

3. The top-mounted backwashing pre-filter according to claim 2, characterized in that: The guide rail (73) is arranged in a continuous arc along the circumference of the rotating lifting mechanism (7), and the height from the lowest point to the highest point of the guide rail (73) is consistent with the maximum stroke of the backwash frame axial adjustment.

4. The top-mounted backwashing pre-filter according to claim 1, characterized in that: A limiting part (74) is also provided at the end of the guide rail part (73), and the limiting part (74) is a limiting protrusion and / or an arc-shaped limiting groove.

5. The top-mounted backwashing pre-filter according to claim 1, characterized in that: The flow channel switching component (2) rotates under the action of external force, which can close the raw water flow channel (21) and / or the purified water flow channel (22), and open the backwash water flow channel (24) at the same time, switching to the backwash mode; it can open the raw water flow channel (21) and the purified water flow channel (22), and close the backwash water flow channel (24), switching to the filtration mode.

6. The top-mounted backwashing pre-filter according to claim 5, characterized in that: The flow channel switching component (2) rotates 30-180° under the action of external force to switch to backwash mode; the flow channel switching component (2) rotates to the same angle in the opposite direction under the action of external force to switch to filtration mode.

7. The top-mounted backwashing pre-filter according to claim 1, 2, 3, 4, 5, or 6, characterized in that: The valve housing cavity (15) is provided with at least one limiting part A (3), and the flow channel switching assembly (2) is provided with at least one matching limiting part B (4). Through the cooperation of the limiting part A (3) and the limiting part B (4), the circumferential limiting or circumferential and axial synchronous limiting of the flow channel switching assembly (2) can be realized.

8. The top-mounted backwashing pre-filter according to claim 7, characterized in that: The valve housing cavity (15) is provided with a limiting part A (3) at the top and bottom respectively. The flow channel switching component (2) is provided with two matching limiting parts B (4). Through the double cooperation of the upper and lower limiting parts A (3) and the limiting parts B (4), the flow channel switching component (2) is double-limited. The limiting part A (3) is a groove or a protrusion structure, and the limiting part B (4) is a protrusion or a groove structure.

9. The top-mounted backwashing pre-filter according to claim 1, 2, 3, 4, 5, or 6, characterized in that: The flow channel switching assembly (2) is provided with a rotation drive component. The rotation drive component is a drive element that extends upward along the filter bottle axis to the bottom of the filter bottle and is rotatably sealed. The flow channel switching assembly (2) is driven by the rotation of the drive element, or the flow channel switching assembly (2) is linked with the sewage discharge assembly. The sewage discharge assembly is rotatably sealed with the sewage discharge end (14). The rotation of the flow channel switching assembly (2) is achieved by the rotation of the sewage discharge assembly.

10. The top-mounted backwashing pre-filter according to claim 9, characterized in that: The rotating drive component is a drive element that extends upward along the filter bottle axis, including a drive handle and a drive rod. One end of the drive rod is fixed to the flow channel switching component (2), and the other end is fixed to the drive handle. Alternatively, the drive element includes a drive handle and a drive frame. The two ends of the drive frame are directly or indirectly fixed to the flow channel switching component (2) and the drive handle, respectively. Alternatively, the drive element includes a drive handle, and the frame of the filter mechanism serves as the drive frame. The two ends of the frame of the filter mechanism are fixed to the drive handle and the flow channel switching component (2), respectively.

11. The top-mounted backwashing pre-filter according to claim 9, characterized in that: The sewage discharge component includes a sewage discharge seal (5) and a sewage discharge valve (6) linked by the flow channel switching component (2). The sewage discharge seal (5) is rotatably sealed to the sewage discharge end (14), and the sewage discharge valve (6) is fixedly connected to the sewage discharge seal (5).

12. The top-mounted backwashing pre-filter according to claim 9, characterized in that: The driving element is a manual driving element and / or an electric driving element.

13. The top-mounted backwashing pre-filter according to claim 1 or 2, characterized in that: A sealing element is provided between the flow channel switching assembly (2) and the valve housing cavity (15), and a rotational sealing connection is achieved through the cooperation of the sealing element.