Precise three-way backwashing valve

Abstract

The precise three-way backwash valve is used for solving the problem that in the prior art, due to the fact that a driving system is complex, the opening synchronism of a water inlet and a sewage discharging plug is poor, and comprises a valve body, the water inlet is formed in one end of the valve body, a filtering opening is formed in the other end of the valve body, the sewage discharging opening is formed in the bottom of the valve body, and a detachable valve cover is arranged at the top end of the valve body. A sealing diaphragm is arranged in the valve body, the sealing diaphragm and the valve cover form a driving bin, a driving device is arranged in the driving bin, a supporting partition plate is arranged in the valve body, the top end of the supporting partition plate is an arc-shaped concave face, the top end of the supporting partition plate can be matched with the sealing diaphragm to seal the water inlet, and a connecting piece is fixed to the bottom face of the sealing diaphragm. The connecting piece is located on the side, close to the filtering opening, of the supporting partition plate and hinged to a connecting rod, and a sewage discharging plug is hinged to the bottom end of the connecting rod. The sealing diaphragm is matched with the connecting piece and the connecting rod to synchronously drive the pollution discharge plug to move, so that the movement synchronism of the sealing diaphragm and the pollution discharge plug is ensured.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of precision three-way backflushing valve, in particular to a precision three-way backflushing valve. BACKGROUND

[0002] The backflushing three-way valve is mainly applied to the filter, and the filter is a precision device for purifying water quality and protecting normal work of other devices in the system by directly intercepting impurities in water by using a filter screen, removing suspended solids and particulate matter in water, reducing turbidity, purifying water quality, and reducing system dirt, algae, corrosion, etc.

[0003] In the existing three-way valve technical field, the traditional device adopts a connecting rod mechanism to realize switching control of the water inlet channel and the blowdown channel. Such structure has the following technical defects: 1. The connecting rod mechanism relies on the coordinated operation of multiple components, and the action lag is easy to occur due to insufficient machining precision or long-term wear, so it is difficult to accurately realize the synchronization of the water inlet closure and the blowdown plug opening, causing water flow control failure; 2. The traditional sealing structure is designed in a plane contact type, which is easy to produce a sealing gap when the fluid pressure fluctuates, causing internal leakage, and there is no effective sealing measure at the transmission rod, which has a water leakage risk; 3. The drive system of the three-way valve usually adopts independent motors or cylinders to control the opening and closing actions of different channels, which not only increases the equipment cost, but also reduces the transmission efficiency due to the complex control logic, and has insufficient reliability when the working conditions need to be frequently switched. SUMMARY

[0004] The present application provides a precision three-way backflushing valve, which solves the problem of poor synchronization of the water inlet and the blowdown plug opening caused by the complex drive system in the prior art.

[0005] The technical scheme of the present application is as follows: A precision three-way backflushing valve, comprising a valve body, one end of the valve body is provided with a water inlet, the other end of the valve body is provided with a filter port, the bottom of the valve body is provided with a blowdown port, the top end of the valve body is provided with a detachable valve cover, a sealing diaphragm is arranged in the valve body, the sealing diaphragm and the valve cover form a drive chamber, a drive device is arranged in the drive chamber, a support partition plate is arranged in the valve body, the top end of the support partition plate is an arc-shaped concave surface, the top end of the support partition plate can cooperate with the sealing diaphragm to close the water inlet, a connecting piece is fixed to the bottom surface of the sealing diaphragm, the connecting piece is located on the side of the support partition plate close to the filter port, the connecting piece is hingedly connected with a connecting rod, and the bottom end of the connecting rod is hingedly connected with a blowdown plug; when the support partition plate is away from the sealing diaphragm, the blowdown plug closes the blowdown port.

[0006] Further, the support partition is provided with a U-shaped channel groove, the bottom surface of the sealing diaphragm is fixed with a baffle, when the sealing diaphragm abuts against the support partition, the baffle can close the channel groove, the driving chamber is fixed with a transmission block, the side wall of the transmission block is fixed with a transmission rack, the bottom end of the baffle is provided with a sealing groove, the sealing groove is provided with a suction cup, the bottom end of the suction cup extends out of the sealing groove, the top end of the suction cup is fixed with a transmission rod penetrating through the baffle and the sealing diaphragm, one end of the transmission rod placed in the driving chamber is fixed with a driven rack, the bottom surface of the valve cover is fixed with a spring telescopic rod, when the bottom end of the suction cup abuts against the channel groove, the spring telescopic rod extends to the longest state, the telescopic end of the spring telescopic rod is rotatably provided with a gear, and the driven rack and the transmission rack are respectively engaged on the two sides of the gear. Through the cooperation of the U-shaped channel groove and the baffle, the water flow direction can be more effectively controlled, the stability and reliability of the filtering process can be ensured, and the filtering efficiency and quality can be improved.

[0007] Further, the suction cup comprises an arc-shaped suction cup area, the periphery of the bottom end of the suction cup area is fixed with a sealing plate made of flexible material, and the baffle abuts against and seals the channel groove through the sealing plate. The periphery of the sealing plate covers to avoid the risk of local sealing failure under high pressure or high flow conditions.

[0008] Further, the driving device comprises an air pipe connected in sealing with the valve cover. By adjusting the air flow pressure and flow in the air pipe, the movement of the sealing diaphragm can be accurately controlled, so that the water flow can be accurately controlled, and the stability and reliability of the valve under different working conditions can be ensured.

[0009] Further, the driving device comprises a telescopic piece fixed at the top end in the valve cover, and the telescopic end of the telescopic piece is fixedly connected with the connecting block. The telescopic piece is directly fixed at the top end of the valve cover and rigidly connected with the connecting block through the telescopic end, so that the overall structure is more compact and occupies less space.

[0010] Further, the transmission rod and the connecting piece are both connected in sealing with the sealing diaphragm through sealing pieces. The sealing pieces can adapt to the pressure fluctuation inside and outside the valve body, automatically enhance the sealing fit under high pressure, and prevent sealing failure caused by pressure sudden change.

[0011] Further, the blowdown opening is provided with an inner ring gasket pipe, the end of the blowdown opening is provided with a connecting pipe opening, the outer side wall of the connecting pipe opening is provided with a clamping shoulder, the connecting pipe opening abuts against the bottom end of the blowdown opening and the inner ring gasket pipe, the side wall of the blowdown opening is screwed with a fixing ring through external threads, the end of the fixing ring is connected with a baffle ring, and the baffle ring can be placed in the clamping shoulder. The clamping shoulder on the outer side of the connecting pipe opening cooperates with the baffle ring, and the fixing ring is screwed in thread design, so that the installation or disassembly of the blowdown pipeline can be quickly completed without complex tools.

[0012] Further, the inner side of the inner ring pad pipe is provided with a guide rib, the side wall of the guide rib is provided with a groove matched with the guide rib, the top end of the blowdown plug is provided with a sealing ring, and the sealing ring is abutted against the valve body. The sealing ring at the top end of the blowdown plug is abutted against the valve body to form an effective seal, so as to prevent medium from leaking at the blowdown port and protect the environment and equipment.

[0013] Further, the two side walls in the channel groove are provided with limiting grooves, the two ends of the baffle slide along the limiting grooves, and the limiting grooves are abutted against the baffle through sliding sealing strips. The use of the sliding sealing strips reduces the direct contact between the baffle and the limiting grooves, reduces the wear speed of the components, prolongs the service life of the valve, and reduces the frequency of maintenance and replacement of components.

[0014] The technical scheme can produce the beneficial effects: The driving device controls the movement of the sealing diaphragm, and the sealing diaphragm drives the blowdown plug to move synchronously through the connecting piece and the connecting rod, so that the synchronism of the movement of the sealing diaphragm and the blowdown plug is ensured, and the waste of water resources caused by the lag of the blowdown plug is avoided. Through the meshing of the gear and the driving rack and the driven rack, not only the sealing property is enhanced by the negative pressure, but also the leakage of water flow from the transmission rod is effectively prevented, and it is ensured that the suction cup can quickly separate from the channel groove, so that the influence of residual negative pressure on the baffle reset is avoided, and reliable mechanical protection is provided for the recovery of the normal filtering state. The driving rack and the driven rack are meshed on both sides of the gear, so that the bidirectional control of the suction cup downward pressing and upward lifting by a single driving source is realized. Compared with a rotating weir gate device which needs an independent driving system, the control logic is significantly simplified, and the transmission efficiency is improved. BRIEF DESCRIPTION OF DRAWINGS

[0015] In order to more clearly illustrate the technical scheme in the embodiments of the present application or the prior art, the drawings needed to be used in the following embodiment or prior art description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creating laborious work.

[0016] Figure 1 It is a schematic view of the three-dimensional structure of the present application; Figure 2 It is a three-dimensional sectional view of the first embodiment; Figure 3 It is a three-dimensional sectional view of the second embodiment; Figure 4 It is a schematic view of the three-dimensional structure of the connection between the sealing diaphragm and the blowdown plug; Figure 5 It is a schematic view of the three-dimensional structure of the baffle; Figure 6 It is a sectional view of the connection between the sealing diaphragm and the blowdown plug; Figure 7 A sectional perspective structural schematic view of the present application.

[0017] Wherein: 1, water inlet, 2, filter port, 3, sewage port, 4, valve cover, 5, sealing diaphragm, 6, drive bin, 7, support partition, 8, connecting piece, 9, connecting rod, 10, sewage plug, 11, channel groove, 12, baffle, 13, transmission block, 14, transmission rack, 15, sealing groove, 16, suction cup, 18, transmission rod, 19, driven rack, 20, spring telescopic rod, 21, gear, 22, sealing plate, 23, air pipe, 24, telescopic piece, 25, sealing piece, 26, inner ring gasket pipe, 27, connecting pipe, 28, clamping shoulder, 29, fixed ring, 30, retaining ring, 31, guide rib, 32, sealing ring, 33, limiting groove, 34, sliding sealing strip. DETAILED DESCRIPTION

[0018] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the protection scope of the present application.

[0019] In the description of the present embodiment, it should be understood that the orientation or positional relationship indicated by the terms "center, longitudinal, transverse, upper, lower, front, rear, left, right, vertical, horizontal, top, bottom, inner, outer" and the like is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application.

[0020] First embodiment: As Figure 1 , 3 -7, the present application provides a precision three-way backwash valve, including valve body, one end of the valve body is provided with water inlet 1, the other end is provided with filter port 2, the bottom of the valve body is provided with sewage port 3, the top end of the valve body is provided with detachable valve cover 4, the valve body is provided with sealing diaphragm 5, sealing diaphragm 5 and valve cover 4 form drive bin 6, drive bin 6 is provided with driving device, the valve body is provided with support partition 7, the top end of support partition 7 is arc concave, the top end of support partition 7 can cooperate with sealing diaphragm 5 to close water inlet 1, the bottom surface of sealing diaphragm 5 is fixed with connecting piece 8, connecting piece 8 is located on one side of support partition 7 close to filter port 2, connecting piece 8 is hinged with connecting rod 9, the bottom end of connecting rod 9 is hinged with sewage plug 10, when support partition 7 is away from sealing diaphragm 5, sewage plug 10 closes sewage port 3.

[0021] In operation, inlet 1 connects to the water source to be filtered, filter port 2 connects to the filter, and drain port 3 connects to the drain pipe. Water enters the valve body through inlet 1 under pressure. The drive unit controls the sealing diaphragm 5 to move away from the supporting partition 7. Simultaneously, the sealing partition, through connector 8, drives the drain plug 10 to close drain port 3, forcing water into the filter and achieving the water filtration function while preventing water from flowing directly out of drain port 3. When cleaning impurities inside the valve body is required, the drive unit drives the sealing diaphragm 5 downwards, causing it to abut against the supporting partition 7 and close inlet 1. Simultaneously, the sealing diaphragm 5, through connecting rod 9, drives the drain plug 10 downwards, opening drain port 3 and allowing impurities and wastewater inside the valve body to drain smoothly. After draining, the drive unit moves the sealing diaphragm 5 upwards, re-abutting against the supporting partition 7 and closing inlet 1. Simultaneously, the drain plug 10, under the action of connecting rod 9, resets and closes drain port 3. The valve returns to normal operation and continues water filtration. The entire process is highly automated and easy to operate, effectively improving work efficiency. The linkage between the drain plug 10 and the sealing diaphragm 5 ensures the timely opening and closing of the drain port 3, effectively preventing impurities from clogging and causing secondary pollution. The removable valve cover 4 allows for periodic removal to check the wear of the sealing diaphragm 5 and the support plate 7, and replacement if necessary.

[0022] like Figure 1 , 3 As shown in Figure 7, a U-shaped channel groove 11 is provided on the support partition 7. A baffle 12 is fixed on the bottom surface of the sealing diaphragm 5. When the sealing diaphragm 5 abuts against the support partition 7, the baffle 12 can close the channel groove 11. A transmission block 13 is fixed inside the drive chamber 6. A transmission rack 14 is fixed on the side wall of the transmission block 13. A sealing groove 15 is provided at the bottom end of the baffle 12. A suction cup 16 is provided inside the sealing groove 15. The bottom end of the suction cup 16 extends out of the sealing groove 15. A transmission rod 18 that penetrates the baffle 12 and the sealing diaphragm 5 is fixed at the top end of the suction cup 16. A driven rack 19 is fixed at one end of the transmission rod placed inside the drive chamber 6. A spring telescopic rod 20 is fixed on the bottom surface of the valve cover 4. When the bottom end of the suction cup 16 abuts against the channel groove 11, the spring telescopic rod 20 extends to its longest state. A gear 21 rotates at the telescopic end of the spring telescopic rod 20. The driven rack 19 and the transmission rack 14 mesh on both sides of the gear 21 respectively.

[0023] The spring telescopic rod 20 is existing technology. A suitable mechanism can be selected based on the actual situation. In this embodiment, the fixed end of the spring telescopic rod 20 is laser-welded to the valve cover 4 via a rigid sleeve. The inner wall of the rigid sleeve has an axial keyway, and the outer wall of the telescopic rod has a corresponding spline ridge. The two slide together to prevent any rotational freedom of the gear 21 outside its own axis, thereby eliminating gear misalignment. The spring of the spring telescopic rod 20 is placed inside the rigid sleeve, with one end of the spring positioned against the inner shoulder of the rigid sleeve, and the other end abutting against the telescopic rod.

[0024] When sewage discharge is required, the drive device pushes the transmission block 13 downward. The transmission rack 14 on the transmission block 13 drives the driven rack 19 and the transmission rod 18 upward through the meshing of the gear 21. When the suction cup 16 abuts against the bottom of the channel groove 11, the length of the spring telescopic rod 20 extends to its longest state, and the transmission rack 14 continues to move downward. The gear 21 applies an upward pulling force to the driven rack 19. The pulling force is transmitted to the suction cup 16 through the transmission rod 18, so that the suction cup 16 forms a negative pressure and abuts against the sealing groove 15. At the same time, the suction cup 16 cooperates with the downward force of the baffle 12 to ensure that the suction cup 16 is tightly connected to the channel groove 11. The negative pressure connection between the suction cup 16 and the channel groove 11 ensures the stability and sealing of the baffle 12 during the sewage discharge process. At the same time, the pulling force on the suction cup 16 will cause the outer wall of the suction cup 16 to abut against the sealing groove 15, preventing the water in the inlet 1 from leaking out through the transmission rod 18.

[0025] When water needs to be discharged from filter port 2, the water pressure pushes the sealing diaphragm 5 upward. The sealing diaphragm 5 drives the baffle 12 and transmission block 13 to move upward synchronously, causing the baffle 12 to move away from the suction cup 16. The transmission rack 14, through meshing with the gear 21, drives the driven rack 19 and transmission rod 18 to move upward, causing the U-shaped channel groove 11 to move away from the suction cup 16. The elastic force of the spring telescopic rod 20 applies a certain thrust to the gear 21 to limit the displacement of the gear 21. At this time, the upward movement of the transmission rack 14 is converted into the downward movement of the driven rack 19 through the gear 21, thereby reducing the negative pressure of the suction cup 16. At the same time, since the channel groove 11 is away from the suction cup 16, it is easier for the suction cup 16 to detach. After the suction cup 16 detaches, the baffle 12 moves away from the U-shaped channel groove 11, restoring the normal filtration state.

[0026] like Figures 4-6As shown, the suction cup 16 includes an arc-shaped suction cup area, with a flexible sealing plate 22 fixed circumferentially at the bottom end of the suction cup area. The baffle 12 is sealed against the channel groove 11 through the sealing plate 22. The sealing plate 22 fixed circumferentially at the bottom end of the suction cup area fits tightly with the arc-shaped structure of the U-shaped channel groove 11, forming a multi-directionally uniformly distributed sealing contact surface, effectively preventing water leakage. The flexible material is rubber or silicone. The flexible sealing plate 22 can adapt to minor unevenness on the surface of the channel groove 11 through slight deformation, improving sealing reliability. The circumferential coverage of the sealing plate 22 avoids the risk of local sealing failure under high pressure or high flow conditions.

[0027] The suction cup 16 is an umbrella-shaped double-layer composite elastomer. The outer layer is made of hydrolysis-resistant EPDM and the inner layer is made of high-resilience TPU. When the transmission rod 18 is pulled upward, the center of the suction cup 16 leaves the valve, and the volume of the inner cavity of the suction cup 16 increases instantaneously, forming an initial negative pressure. When the pulling stops, the umbrella plate self-seals the valve port under the action of water pressure difference, ensuring that the suction cup 16 remains in close contact with the channel groove 11 during the filtration cycle.

[0028] like Figure 1 , 3 As shown, the drive device includes an air pipe 23 that is sealed to the valve cover 4. By adjusting the air pressure and flow rate in the air pipe 23, the movement of the sealing diaphragm 5 can be accurately controlled, thereby achieving precise control of the water flow and ensuring the stability and reliability of the valve under different operating conditions. The pneumatic drive requires no electrical input, eliminates the risk of electrical sparks, and is suitable for flammable, explosive, high-humidity, or corrosive environments. The pneumatic system has a simple structure, low failure rate, and the modular connection design between the air pipe 23 and the valve cover 4 facilitates quick disassembly and maintenance.

[0029] like Figure 1 , 5 As shown in Figure 7, both the transmission rod 18 and the connecting piece 8 are sealed to the sealing diaphragm 5 via a sealing element 25. The use of the sealing element 25 effectively prevents media leakage between the transmission rod 18, the connecting piece 8, and the sealing diaphragm 5, ensuring the valve's sealing performance, reducing media loss and environmental pollution, and improving the valve's reliability and service life. The sealing element 25 can be made of flexible materials such as rubber or polytetrafluoroethylene to wrap the transmission rod 18 and the connecting piece 8, allowing the transmission rod 18 to move flexibly while ensuring a seal.

[0030] like Figure 6 , 7 As shown, the drain outlet 3 is provided with an inner ring gasket 26, and the end of the drain outlet 3 is provided with a connecting pipe port 27. The outer side wall of the connecting pipe port 27 is provided with a snap-fit ​​shoulder 28. The connecting pipe port 27 abuts against the bottom end of the drain outlet 3 and the inner ring gasket 26. The side wall of the drain outlet 3 is screwed with a fixing ring 29 by an external thread. The end of the fixing ring 29 is connected with a retaining ring 30, which can be placed inside the snap-fit ​​shoulder 28.

[0031] The connecting pipe port 27 abuts against the bottom end of the drain port 3 and the inner ring gasket 26. The connecting pipe port 27 is further secured by the externally threaded fixing ring 29 and the retaining ring 30 placed within the snap-fit ​​shoulder 28, preventing loosening and ensuring the stability of the sewage discharge process. The rational design of the inner ring gasket 26 and the connecting pipe port 27 reduces the direct scouring and corrosion of the drain port 3 by sewage, protecting the structural integrity of the drain port 3 and extending the valve's service life. The inner ring gasket 26, as a wear part, can be replaced individually, preventing the entire drain port 3 from being scrapped due to wear or corrosion, thus reducing maintenance costs. The abutment between the inner ring gasket 26 and the connecting pipe port 27 forms the first seal. After the fixing ring 29 is tightened by the thread, it pushes the retaining ring 30 to press against the snap-fit ​​shoulder 28, forming the second mechanical seal. This double-seal design effectively prevents sewage leakage.

[0032] like Figure 1 , 2 As shown in Figure 7, the inner ring gasket 26 has a guide rib 31 on its inner side, and the side wall of the guide rib 31 has a groove that mates with the guide rib 31. The top of the drain plug 10 has a sealing ring 32, which abuts against the valve body. The guide rib 31 on the inner side of the inner ring gasket 26 mates with the groove on the side wall of the drain plug 10, providing precise axial guidance for the drain plug 10, ensuring that it maintains linear movement during operation, avoiding deviation or jamming, and improving the reliability and stability of valve operation. The sealing ring 32 at the top of the drain plug 10 abuts against the valve body, forming an effective seal, preventing the medium from leaking at the drain port 3, protecting the environment and equipment, and improving the sealing performance and service life of the entire valve.

[0033] like Figure 7 As shown, limiting grooves 33 are provided on both side walls of the channel groove 11. The two ends of the baffle 12 slide along the limiting grooves 33, and the limiting grooves 33 abut against the baffle 12 through the sliding sealing strip 34. The sliding sealing strip 34 is existing technology. The limiting grooves 33 on both side walls of the channel groove 11 provide a precise guiding path for the sliding of the baffle 12, ensuring that the baffle 12 always maintains a straight line during movement, avoiding deviation or jamming, and improving the reliability and stability of valve operation. The sliding sealing strip 34 not only reduces the friction between the baffle 12 and the limiting grooves 33, but also prevents the medium from leaking from the limiting grooves 33, enhancing the sealing performance of the entire valve. The cooperation between the guide rib 31 and the groove can block large particles of impurities from entering the movement track, preventing the drain plug 10 from being unable to close due to impurities. The baffle 12 presses the sliding sealing strip 34 under the water flow pressure. The greater the pressure, the stronger the sealing effect, realizing dynamic pressure compensation.

[0034] Second embodiment: like Figure 1 , 2As shown in Figures 4-7, the driving device includes a telescopic member 24 fixed to the top of the valve cover 4. The telescopic end of the telescopic member 24 is fixedly connected to the connecting block. The telescopic member 24 can be an existing hydraulic, pneumatic telescopic rod, or screw jack unit. The telescopic member 24 is directly fixed to the top of the valve cover 4 and rigidly connected to the connecting block through its telescopic end, making the overall structure more compact and occupying less space. The linear movement of the telescopic member 24 acts directly on the baffle 12 or the sealing diaphragm 5 through the connecting block, reducing energy loss during the energy transfer process and improving driving efficiency. The rigid fixed connection between the telescopic member 24 and the valve cover 4 enhances the vibration resistance of the driving device and avoids transmission deviation caused by water flow impact or external vibration. Other structures in this embodiment are the same as in Embodiment 1.

[0035] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A precision three-way backwash valve, comprising a valve body, one end of which is provided with a water inlet (1), the other end with a filter port (2), and the bottom of which is provided with a drain port (3), characterized in that: The valve body is provided with a removable valve cover (4) at the top and a sealing diaphragm (5) inside the valve body. The sealing diaphragm (5) and the valve cover (4) form a drive chamber (6). The drive chamber (6) is provided with a drive device. The valve body is provided with a support plate (7). The top of the support plate (7) is an arc-shaped concave surface. The top of the support plate (7) can cooperate with the sealing diaphragm (5) to seal the water inlet (1). The bottom surface of the sealing diaphragm (5) is fixed with a connector (8). The connector (8) is located on the side of the support plate (7) near the filter port (2). The connector (8) is hinged with a connecting rod (9). The bottom end of the connecting rod (9) is hinged with a drain plug (10). When the support plate (7) is far away from the sealing diaphragm (5), the drain plug (10) seals the drain port (3).

2. The precision three-way backflushing valve according to claim 1, characterized in that: The supporting partition (7) has a U-shaped channel groove (11). A baffle (12) is fixed on the bottom surface of the sealing diaphragm (5). When the sealing diaphragm (5) abuts against the supporting partition (7), the baffle (12) can close the channel groove (11). A transmission block (13) is fixed inside the drive chamber (6). A transmission rack (14) is fixed on the side wall of the transmission block (13). A sealing groove (15) is provided at the bottom end of the baffle (12). A suction cup (16) is provided inside the sealing groove (15). The bottom end of the suction cup (16) extends out of the sealing groove (15). The top of 6) is fixed with a transmission rod (18) that passes through the baffle (12) and the sealing diaphragm (5). One end of the transmission rod is fixed with a driven rack (19) inside the drive chamber (6). The bottom surface of the valve cover (4) is fixed with a spring telescopic rod (20). When the bottom end of the suction cup (16) abuts against the channel groove (11), the spring telescopic rod (20) extends to its longest state. The telescopic end of the spring telescopic rod (20) has a gear (21) that rotates. The driven rack (19) and the transmission rack (14) mesh on both sides of the gear (21).

3. A precision three-way backflushing valve according to claim 2, characterized in that: The suction cup (16) includes an arc-shaped suction cup area, and a flexible sealing plate (22) is fixed circumferentially at the bottom of the suction cup area. The baffle (12) is sealed against the channel groove (11) through the sealing plate (22).

4. A precision three-way backflushing valve according to claim 1, characterized in that: The drive unit includes an air pipe (23) that is sealed to the valve cover (4).

5. A precision three-way backflushing valve according to claim 1, characterized in that: The drive device includes a telescopic member (24) fixed at the top of the valve cover (4), and the telescopic end of the telescopic member (24) is fixedly connected to the connecting block.

6. A precision three-way backflushing valve according to claim 2, characterized in that: The transmission rod (18) and the connecting piece (8) are both sealed and connected to the sealing diaphragm (5) through the sealing piece (25).

7. A precision three-way backflushing valve according to claim 1, characterized in that: The drain outlet (3) is provided with an inner ring gasket (26), and the end of the drain outlet (3) is provided with a connecting pipe (27). The outer side wall of the connecting pipe (27) is provided with a snap-fit ​​shoulder (28). The connecting pipe (27) abuts against the bottom of the drain outlet (3) and the inner ring gasket (26). The side wall of the drain outlet (3) is screwed with a fixing ring (29) by an external thread. The end of the fixing ring (29) is connected with a retaining ring (30). The retaining ring (30) can be placed inside the snap-fit ​​shoulder (28).

8. A precision three-way backflushing valve according to claim 7, characterized in that: The inner ring gasket (26) is provided with a guide rib (31) on its inner side. The side wall of the guide rib (31) is provided with a groove that cooperates with the guide rib (31). The top of the drain plug (10) is provided with a sealing ring (32) that abuts against the valve body.

9. A precision three-way backflushing valve according to claim 2, characterized in that: Limiting grooves (33) are provided on both side walls of the channel groove (11). The two ends of the baffle (12) slide along the limiting grooves (33). The limiting grooves (33) abut against the baffle (12) through the sliding sealing strip (34).

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