Differential pressure sensing device for a filter and filter

Abstract

The present invention discloses a differential pressure sensing device for a filter, which relates to the field of filters. The technical key points are as follows: It includes a main housing, an adjusting member, an elastic member and a water distributor. The main housing includes a balance chamber and a first water inlet, a second water inlet and a connection port communicated with the balance chamber. The first water inlet is communicated with the filter water inlet, and the second water inlet is communicated with the filter water outlet. The adjusting member is movably arranged in the balance chamber and divides the balance chamber into a first chamber and a second chamber isolated from each other in the moving direction. The first chamber is communicated with the first water inlet, and the second chamber is communicated with the second water inlet. The elastic member is arranged between the main housing and the adjusting member and is used to provide an elastic force for the adjusting member to move towards the first water inlet direction. The differential pressure sensing device and the filter of the present invention do not require electronic components and power sources, realize the induction of the filter water pressure through a mechanical structure, and automatically control the filter to perform backwashing, with low production and use costs and long service life.

Description

Technical Field

[0001] The present invention relates to the field of filters, and particularly to a differential pressure sensing device and a filter for a filter. Background Art

[0002] The differential pressure sensing device of a filter is used to sense the water pressure difference between two flow channels of the filter, and is commonly used in the backwashing structure of the filter. When a certain amount of impurities accumulates on the filter element, the water pressure difference between the inner and outer flow channels of the filter element increases. After being sensed by the differential pressure sensing device, it controls the reverse flow of the water flow of the filter and flushes the impurities on the filter element, achieving the effect of automatically flushing the filter element.

[0003] The existing differential pressure sensing device of a filter mainly includes a solenoid valve and a water pressure sensor. The water pressure sensor senses the water pressure of the flow channel. When the water pressure difference reaches the set value, the controller controls the solenoid valve to open, and the reverse water flow flushes the filter element.

[0004] When implementing the technical solution of the present invention, the inventor found that the existing differential pressure sensing device of a filter has the following technical problems:

[0005] The existing differential pressure sensing device of a filter realizes the differential pressure sensing and the control of the backwashing water flow through a controller and electronic components, and requires the use of a power source. After using for a period of time, when the battery is exhausted or the electronic components are damaged, it will not be able to work normally, and the battery or electronic components need to be replaced from time to time, resulting in a lower service life and higher cost. Summary of the Invention

[0006] (I) Technical Problems to be Solved

[0007] The present invention provides a differential pressure sensing device for a filter, which at least solves the problem that the existing differential pressure sensing device of a filter needs to use a power source and electronic components and has a lower service life, and can reduce the cost of realizing the differential pressure sensing function of the filter.

[0008] (II) Technical Solutions

[0009] To solve the above technical problems, the present invention provides the following technical solutions:

[0010] A differential pressure sensing device for a filter, including a filtering state and a backwashing state, comprising:

[0011] A main housing, the main housing includes a balance chamber and a first water inlet, a second water inlet and a connection port communicating with the balance chamber. The first water inlet communicates with the water inlet of the filter, and the second water inlet communicates with the water outlet of the filter;

[0012] An adjusting member, which is movably arranged in the balance chamber and divides the balance chamber into a first chamber and a second chamber isolated from each other in the moving direction. The first chamber communicates with the first water inlet, and the second chamber communicates with the second water inlet;

[0013] An elastic member, disposed between the main housing and the adjusting member, and used to provide elastic force for the adjusting member to move toward the first water inlet;

[0014] A water distributor, comprising a main pipe connected to the connection port, a branch pipe connected to the main pipe, and a valve stem movably arranged in the main pipe, the number of the branch pipes is at least two, and one of the branch pipes is connected to the filter backwashing channel, and the valve stem is linked to the regulating member and is used to control the flow channel between the branch pipes;

[0015] Wherein, when the pressure difference sensing device is in the filtering state, the valve stem closes the flow channel between the branch pipes, and when it is in the backwashing state, the regulating member moves toward the second cavity, and the valve stem is linked to open the flow channel between the branch pipes.

[0016] In a further arrangement, the adjusting member comprises a first partition and a second partition arranged in parallel and at intervals, the first partition and the second partition are sealed and fitted to the inner side of the balancing cavity, the first cavity is located on the side of the first partition away from the second partition, and the second cavity is located at the center of the side of the second partition away from the first partition.

[0017] In a further arrangement, the adjusting member further includes a guide shaft, which is connected to the center of the side of the second partition away from the first partition, and the main shell includes a guide hole located in the second cavity and for the guide shaft to movably pass through. The elastic member is a linear spring, which is sleeved on the guide shaft, and its two ends are respectively against the second partition and the main shell.

[0018] In a further arrangement, the guide hole is communicated with the second water inlet.

[0019] In a further arrangement, the adjusting member further comprises a frustum arranged between the first partition plate and the second partition plate, the cross-sectional radius of the frustum gradually decreases from the first partition plate toward the second partition plate, and the side surface of the frustum is arranged toward the valve stem; when the pressure differential sensing device is in a backwashing state, the side surface of the frustum contacts the valve stem and pushes the valve stem to open the flow channel between the branch pipes, and the water distributor further comprises a return spring connected to the valve stem and providing elastic force for the valve stem to move to a position to close the flow channel between the branch pipes.

[0020] In a further arrangement, the valve stem includes an inner core arranged in the main pipe, an inner core bracket movably sleeved inside the inner core, and a linkage joint connected to the inner core bracket, the inner core includes a guide hole connecting the flow channels between the branch pipes, the inner core bracket is used to control the opening and closing of the guide hole, and the linkage joint is used to contact the side of the cone.

[0021] In a further arrangement, the linkage joint includes a sliding groove, and the inner core support includes a sliding block which is slidably arranged in the sliding groove and is limited within the sliding groove at both ends in the sliding direction. The return spring sleeves the inner core support and abuts against the linkage joint and the inner core at both ends respectively.

[0022] In a further arrangement, a first sealing ring is spacedly arranged around the inner core and is hermetically connected to the main pipe through the first sealing ring. A first flow channel communicating with the branch pipe is formed between the first sealing rings. A second sealing ring is spacedly arranged around the inner core support and is hermetically connected to the inner core through the second sealing ring. A second flow channel is formed between the second sealing rings. The second flow channel communicates with the first flow channel through a diversion hole. The first flow channel and the second flow channel form a flow channel between the branch pipes. When the differential pressure sensing device is in the filtering state, the second sealing ring blocks the flow channel between adjacent branch pipes.

[0023] In a further arrangement, the main housing includes an upper housing and a lower housing. The first water inlet and the connection port are arranged on the lower housing, and the second water inlet is arranged on the upper housing.

[0024] The present invention also provides a filter, including the differential pressure sensing device of the above filter.

[0025] (III) Beneficial effects

[0026] Compared with the prior art, the differential pressure sensing device and the filter of the filter provided by the present invention have the following beneficial effects:

[0027] The differential pressure sensing device of the filter of the present invention divides the balance cavity of the main housing into a first cavity and a second cavity through an adjusting member. The first cavity communicates with the first water inlet, and the second cavity communicates with the second water inlet. An elastic member is arranged between the main housing and the adjusting member. When the water inlet pressure of the filter is equal to the sum of the water outlet pressure of the filter and the elastic force of the elastic member, the adjusting member is in force balance. At the same time, the backwashing water flow enters the main pipe from one branch pipe and can be introduced into the filter backwashing channel through the other branch pipe; when the differential pressure sensing device is in the filtering state, the valve rod is located at the initial position and closes the flow channel between the branch pipes, and the filter normally filters the water flow; when debris accumulates on the filter element of the filter and the water outlet pressure decreases, the adjusting member moves towards the second cavity direction, and the valve rod is linked during the movement to open the flow channel between the branch pipes, and the differential pressure sensing device enters the backwashing state. The backwashing water flow introduced from one branch pipe enters the filter backwashing channel through the other branch pipe to backwash the filter element of the filter; after the flushing is completed, the water outlet pressure of the filter returns to the initial state, the adjusting member returns to the initial position, the valve rod is linked to the position where the flow channel between the branch pipes is closed, and the backwashing water flow is blocked. At this time, the filter resumes the filtering function.

[0028] It can be seen that the differential pressure sensing device and the filter of the present invention do not require the use of electronic components and power sources, realize the induction of the water pressure of the filter through a mechanical structure, and automatically control the filter to perform backwashing, with low production and use costs and a long service life. Description of the Drawings

[0029] Figure 1 It is a perspective view of the differential pressure sensing device in the embodiment;

[0030] Figure 2 It is an exploded view of the differential pressure sensing device in the embodiment;

[0031] Figure 3 It is a schematic diagram of the differential pressure sensing device in the filtering state in the embodiment;

[0032] Figure 4 It is a schematic diagram of the water distributor in the filtering state in the embodiment;

[0033] Figure 5 It is a schematic diagram of the differential pressure sensing device in the backwashing state in the embodiment;

[0034] Figure 6 It is a perspective view of the inner core bracket, the linkage joint and the return spring in the embodiment;

[0035] Figure 7 It is an exploded view of the inner core in the embodiment;

[0036] Figure 8 It is a schematic diagram of the filter in the filtering state in the embodiment;

[0037] Figure 9 It is a schematic diagram of the filter in the backwashing state in the embodiment.

[0038] Reference numerals: main housing 1, adjusting member 2, elastic member 3, water distributor 4, balance chamber 10, upper housing 11, lower housing 12, first partition 21, second partition 22, guide shaft 23, frustum 24, main pipe 41, branch pipe 42, inner core 43, inner core bracket 44, linkage joint 45, return spring 46, pressure gauge connector 47, opening 50, outer chamber 51, filter element 52, inner chamber 53, filter outlet 54, filter inlet 55, sewage outlet 56, first water inlet 101, second water inlet 102, connection port 103, first cavity 104, second cavity 105, guide hole 106, sleeve hole 401, first flow channel 402, second flow channel 403, diversion hole 430, first sealing ring 431, slider 440, second sealing ring 441, chute 450, filter inlet water flow a. Detailed Embodiments

[0039] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the drawings in the embodiments of the present invention.

[0040] Refer to Figure 1 、 Figure 2 、 Figure 3 、 Figure 4 and Figure 5 As shown, this embodiment provides a differential pressure sensing device for a filter, including a filtering state and a backwashing state, and mainly including components such as a main housing 1, an adjusting member 2, an elastic member 3, and a water distributor 4.

[0041] The main housing 1 includes a balance chamber 10 and a first water inlet 101, a second water inlet 102, and a connection port 103 communicating with the balance chamber 10. The first water inlet 101 communicates with the filter water inlet 55, and the second water inlet 102 communicates with the filter water outlet 54.

[0042] The interior of the above-mentioned main housing 1 is hollow, and the hollow part forms a balance chamber 10. Among them, the main housing 1 can adopt an integral structure or a split structure. In the case of a split structure, an upper and lower structure or a left and right structure can be adopted; the water flow at the filter water inlet 55 flows out from the filter water outlet 54 after passing through the filter element 52. The water pressure at the first water inlet 101 is the same as the water pressure at the filter water inlet 55, and the water pressure at the second water inlet 102 is the same as the water pressure at the filter water outlet 54, and they can be connected through pipelines.

[0043] The adjusting member 2 is movably arranged in the balance chamber 10 and divides the balance chamber 10 into a first chamber 104 and a second chamber 105 that are isolated from each other in the moving direction. The first chamber 104 communicates with the first water inlet 101, and the second chamber 105 communicates with the second water inlet 102.

[0044] Both ends of the adjusting member 2 are respectively affected by the water pressure in the first chamber 104 and the water pressure in the second chamber 105, that is, respectively affected by the water pressure at the filter water inlet 55 and the water pressure at the water outlet. The first chamber 104 and the second chamber 105 are isolated, so that the water flow inside them cannot flow, ensuring the formation of a pressure difference.

[0045] The elastic member 3 is arranged between the main housing 1 and the adjusting member 2 and is used to provide an elastic force for the adjusting member 2 to move in the direction of the first water inlet 101.

[0046] The elastic force provided by the above-mentioned elastic member 3 is used to balance the pressure difference at both ends of the adjusting member 2, that is, the filter inlet water pressure is equal to the sum of the filter outlet water pressure and the elastic force of the elastic member 3, so that the adjusting member 2 is in dynamic balance.

[0047] The water separator 4 includes a main pipe 41, branch pipes 42 and a valve stem. The main pipe 41 communicates with the connection port 103, the branch pipes 42 communicate with the main pipe 41, and the valve stem is movably arranged in the main pipe 41; the number of the branch pipes 42 is at least two, and one branch pipe 42 communicates with the filter backwash channel. The valve stem is linked with the adjusting member 2 and is used to control the on-off between the branch pipes 42. The main pipe 41 can be connected to a pressure gauge connector 47 as required.

[0048] The main pipe 41 and the branch pipes 42 can be integrally formed or connected by threads. The branch pipes 42 can be externally connected to the backwash water path or the backwash channel through connectors. The backwash water is introduced through one branch pipe 42, flows out from the other branch pipe 42 after passing through the valve stem. The valve stem controls the opening and closing of the backwash water flow through linkage with the adjusting member 2; the backwash channel communicates with the inner cavity 53 of the filter.

[0049] Among them, when the differential pressure sensing device is in the filtering state, the valve stem closes the flow channel between the branch pipes 42. When in the backwash state, the adjusting member 2 moves towards the second cavity 105, and the valve stem is linked and opens the flow channel between the branch pipes 42.

[0050] The above-mentioned filtering state refers to the state when the filter is working normally and filtering the water flow. The differential pressure sensing device blocks the introduction of the backwash water flow at the branch pipes 42 in the filtering state. The backwash state refers to the state when the filter is backwashed due to impurity blockage. The differential pressure sensing device introduces the backwash water flow in this state.

[0051] The differential pressure sensing device of the above technical solution divides the balance chamber 10 of the main housing 1 into a first chamber 104 and a second chamber 105 through an adjusting member 2. The first chamber 104 is connected to the first water inlet 101, and the second chamber 105 is connected to the second water inlet 102. An elastic member 3 is arranged between the main housing 1 and the adjusting member 2. When the water pressure of the filter inlet is equal to the sum of the water pressure of the filter outlet and the elastic force of the elastic member 3, the adjusting member 2 is balanced, and the backwashing water flows through a branch pipe 42 into the main pipe 41 and is introduced into the filter backwashing channel through another branch pipe 42. When the differential pressure sensing device is in the filtering state, the valve stem is in the initial position and closes the flow channel between the branch pipes 42, and the filter filters the water flow normally. When the filter is filtered, the valve stem 42 is in the initial position and closes the flow channel between the branch pipes 42. When the filter element 52 accumulates debris and the outlet water pressure decreases, the regulating member 2 moves toward the second cavity 105, and during the movement, the valve stem is linked to open the flow channel between the branch pipes 42, and the differential pressure sensing device enters the backwashing state, in which the backwashing water flow introduced by one branch pipe 42 enters the filter backwashing channel through another branch pipe 42 to backwash the filter element 52 of the filter. At this time, the filter inlet water flow a can be closed, and the sewage after backwashing can be discharged from the sewage outlet 56; after the flushing is completed, the filter outlet water pressure returns to the initial state, the regulating member 2 returns to the initial position, and the valve stem is linked to the position of closing the flow channel between the branch pipes 42, and the backwashing water flow is blocked, and the filter resumes the filtering function. It can be seen that the differential pressure sensing device and filter of the present invention do not need to use electronic components and power supplies, and realize the induction of the filter water pressure through a mechanical structure, and automatically control the filter to backwash, with low production and use costs and long service life.

[0052] See also Figure 2 and Figure 3 In one embodiment of the adjusting member 2, the adjusting member 2 includes a first partition plate 21 and a second partition plate 22, and the first partition plate 21 and the second partition plate 22 are sealed and attached to the inner side of the balancing chamber 10, and the sealing can be achieved by a sealing ring at the attached part. The first cavity 104 is located on the side of the first partition plate 21 away from the second partition plate 22, and the second cavity 105 is located on the side of the second partition plate 22 away from the first partition plate 21. The first partition plate 21 and the second partition plate 22 are relatively parallel and spaced apart, and the water pressure area of the adjusting member 2 is increased.

[0053] To facilitate the installation of the elastic member 3 and apply the elastic force in the vertical direction at the middle of the second partition plate 22, the adjusting member 2 further includes a guide shaft 23. The guide shaft 23 is connected to the side of the second partition plate 22 away from the first partition plate 21, and the connection method is preferably integrally formed. The main housing 1 includes a guide hole 106 located in the second cavity 105 and through which the guide shaft 23 movably passes. The elastic member 3 is a linear spring, which is sleeved on the guide shaft 23 and has two ends respectively abutted against the second partition plate 22 and the main housing 1. Among them, the hole wall of the guide hole 106 extends into the second cavity 105 and serves as the abutting position of the linear spring on the main housing 1. In this way, when the first partition plate 21 is acted on by the water pressure in the first cavity 104 and the adjusting member 2 squeezes the linear spring, the elastic force of the linear spring is opposite to the acting force of the first cavity 104 on the adjusting member 2, and the adjusting member 2 is stressed on a straight line, avoiding the jamming of the adjusting member 2 with the wall of the balance cavity 10, so that the adjusting member 2 can slide smoothly in the balance cavity 10, improving the sensitivity of the differential pressure sensing device to the induction of the pressure difference.

[0054] To further improve the sensitivity of the differential pressure sensing device to the induction of the pressure difference, the guide hole 106 is communicated with the second water inlet 102, and the water pressure of the second water inlet 102 can directly act on the guide shaft 23. Compared with acting on the second partition plate 22, the acting force is closer to the center of the adjusting member 2, and the adjusting member 2 is less likely to be skewed and jammed. At this time, the guide hole 106 is equivalent to a part of the second cavity 105.

[0055] In an implementation manner where the adjusting member 2 is linked with the valve stem, the adjusting member 2 further includes a frustum 24 arranged between the first partition plate 21 and the second partition plate 22. The cross-sectional radius of the frustum 24 gradually decreases from the first partition plate 21 to the second partition plate 22, and the side surface of the frustum 24 faces the valve stem. When the differential pressure sensing device is in the backwashing state, the side surface of the frustum 24 contacts the valve stem and pushes the valve stem to open the flow channel between the branch pipes 42, that is, a part of the water pressure on the side surface of the frustum 24 is converted into the thrust to push the valve stem to move. The water distributor 4 further includes a return spring 46 connected to the valve stem and providing an elastic force for the valve stem to move to the position of closing the flow channel between the branch pipes 42. In this implementation manner, a slope adapted to the side surface of the frustum 24 can also be opened at one end of the valve stem facing the side surface of the frustum 24. During backwashing, the adjusting member 2 pushes the valve stem through the side surface of the frustum 24 to open the flow channel between the branch pipes 42. During normal filtration, the adjusting member 2 is reset by the action of the return spring 46 and closes the flow channel between the branch pipes 42, realizing the linkage of the valve stem with the adjusting member 2.

[0056] Of course, the adjusting member 2 and the valve stem can also be linked through a connecting rod, that is, one end of the connecting rod is hinged to one end of the valve stem close to the adjusting member 2, and the other end of the connecting rod is hinged to the adjusting member 2. When the adjusting member 2 moves, it drives the valve stem to move through the connecting rod.

[0057] Refer to Figure 3 and Figure 6, As shown, in an embodiment of the valve stem, the valve stem includes an inner core 43, an inner core support 44, and a linkage joint 45. The inner core 43 is disposed within the main pipe 41. An axial through-hole 401 is formed in the inner core 43. The inner core support 44 is movably sleeved within the through-hole 401 inside the inner core 43. The linkage joint 45 is connected to the inner core support 44 and is used to drive the inner core support 44 to move within the through-hole 401. The inner core 43 includes a diversion hole 430 that communicates with the flow channels between the branch pipes 42. The inner core support 44 is used to control the opening and closing of the diversion hole 430, thereby controlling the opening and closing of the flow channels between the branch pipes 42. The linkage joint 45 is used to contact the side surface of the frustum 24. The valve stem of this embodiment realizes linkage by contacting the side surface of the frustum 24 through the linkage joint 45, and then drives the inner core support 44 to move relative to the inner core 43 to open and close the flow channels between the branch pipes 42.

[0058] In order to enable the valve stem to have a delay and buffering effect when linked with the adjusting member 2, the linkage joint 45 includes a chute 450, and the inner core support 44 includes a slider 440. The slider 440 is slidably disposed within the chute 450 and is limited within the chute 450 at both ends in the sliding direction. A return spring 46 is sleeved around the inner core support 44 and abuts against the linkage joint 45 and the inner core 43 at both ends respectively. That is, when the adjusting member 2 moves towards the second cavity 105, the linkage joint 45 does not immediately push the inner core support 44 to move. Instead, the slider 440 slides relative to the chute 450 until it contacts the end of the chute 450, and then starts to push the inner core support 44 to close the diversion hole 430. In this way, appropriate fluctuations in the water pressure in the first and second cavities 105 will not cause the valve stem to move, enabling the linkage of the adjusting member 2 to the valve stem to have a certain degree of fault tolerance and improving the product reliability.

[0059] Combined with Figure 4 and Figure 7 , in an embodiment of the cooperation between the inner core 43 and the inner core support 44, first sealing rings 431 are spaced around the outer periphery of the inner core 43 and are hermetically connected to the main pipe 41 through the first sealing rings 431. A first flow channel 402 communicating with the branch pipes 42 is formed inside the main pipe 41 between the first sealing rings 431. Each branch pipe 42 is connected to a first flow channel 402. Second sealing rings 441 are spaced around the outer periphery of the inner core support 44 and are hermetically connected to the inner core 43 through the second sealing rings 441. A second flow channel 403 is formed between the second sealing rings 441. The second flow channel 403 communicates with the first flow channel 402 through the diversion hole 430. The first flow channel 402 and the second flow channel 403 form the flow channels between the branch pipes 42. When the differential pressure sensing device is in the filtering state, the second sealing rings 441 block the flow channels between adjacent branch pipes 42. The backwashing water flow enters the corresponding first flow channel 402 from one branch pipe 42, enters the second flow channel 403 through a diversion hole 430, then enters another first flow channel 402 through another diversion hole 430, and finally flows out from another branch pipe 42. In the filtering state, the second sealing rings 441 move between the two second flow channels 403 to block the backwashing water flow.

[0060] In an embodiment of the main housing 1, the main housing 1 includes an upper housing 11 and a lower housing 12 connected by threads. The first water inlet 101 and the connection port 103 are provided on the lower housing 12, and the second water inlet 102 is provided on the upper housing 11.

[0061] Refer to Figure 8 and Figure 9 , this embodiment provides a filter, including the above-mentioned differential pressure sensing device. An opening 50 is formed at the top of the filter and is communicated with the first water inlet 101. The opening 50 is communicated with the outer cavity 51 of the filter. During filtration, water flows into the outer cavity 51 from the filter water inlet 55, passes through the filter element 52 for filtration, then enters the inner cavity 53, and finally flows out from the filter water outlet 54; during backwashing, the inlet water flow a of the filter can be closed. The backwashing water flows into the inner cavity 53 from the branch pipe 42 or enters the inner cavity 53 from the filter water outlet 54 to backwash the filter element 52 in the reverse direction, and the sewage discharge port 56 is opened. The sewage after backwashing can be discharged from the sewage discharge port 56.

[0062] It should be noted that the filtration direction of the filter element of the filter can be from the inside to the outside or from the outside to the inside. The above embodiment is described with the filtration direction from the outside to the inside. Those skilled in the art can adjust the connection position of the branch pipe and the backwashing channel according to the filtration direction of the filter element and the specific structure of the filter, which will not be elaborated here.

[0063] Although the embodiments of the present invention have been shown and described, for those of ordinary skill in the art, it can be understood that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A differential pressure sensing device for a filter, including a filtering state and a backwashing state, characterized in that, include: A main housing, the main housing comprising a balancing chamber and a first water inlet, a second water inlet and a connecting port connected to the balancing chamber, wherein the first water inlet is connected to a water inlet of the filter, and the second water inlet is connected to a water outlet of the filter; an adjusting member, which is movably arranged in the balancing cavity and divides the balancing cavity into a first cavity and a second cavity isolated from each other in a moving direction, the first cavity is communicated with the first water inlet, and the second cavity is communicated with the second water inlet; An elastic member, disposed between the main housing and the adjusting member, and used to provide elastic force for the adjusting member to move toward the first water inlet; A water distributor, comprising a main pipe connected to the connection port, a branch pipe connected to the main pipe, and a valve stem movably arranged in the main pipe, the number of the branch pipes is at least two, and one of the branch pipes is connected to the filter backwashing channel, and the valve stem is linked to the regulating member and is used to control the flow channel between the branch pipes; Wherein, when the pressure difference sensing device is in the filtering state, the valve stem closes the flow channel between the branch pipes, and when it is in the backwashing state, the regulating member moves toward the second cavity, the valve stem is linked and opens the flow channel between the branch pipes; The regulating member comprises a first baffle and a second baffle arranged in parallel and at intervals, the first baffle and the second baffle are sealed and attached to the inner side of the balancing cavity, the first cavity is located at a side of the first baffle away from the second baffle, and the second cavity is located at the center of a side of the second baffle away from the first baffle; The adjusting member further comprises a guide shaft, which is connected to the center of the second partition away from the first partition, the main housing comprises a guide hole located in the second cavity and for the guide shaft to movably pass through, the elastic member is a linear spring, which is sleeved on the guide shaft, and the two ends of the linear spring are respectively against the second partition and the main housing; The regulating member further comprises a truncated cone disposed between the first baffle and the second baffle, the cross-sectional radius of the truncated cone gradually decreases from the first baffle toward the second baffle, and the side surface of the truncated cone is disposed toward the valve stem; when the differential pressure sensing device is in a backwashing state, the side surface of the truncated cone contacts the valve stem and pushes the valve stem to open the flow channel between the branch pipes, and the water distributor further comprises a return spring connected to the valve stem and providing elastic force for the valve stem to move to a position to close the flow channel between the branch pipes; The valve stem comprises an inner core arranged in the main pipe, an inner core bracket movably sleeved inside the inner core, and a linkage joint connected to the inner core bracket, the inner core comprises a guide hole communicating with the flow channel between the branch pipes, the inner core bracket is used to control the opening and closing of the guide hole, and the linkage joint is used to contact the side surface of the truncated cone; The linkage joint includes a slide groove, the inner core bracket includes a slider, the slider is slidably arranged in the slide groove and is limited in the slide groove at both ends in the sliding direction, the return spring is sleeved on the inner core bracket and the two ends are respectively against the linkage joint and the inner core; A first sealing ring is arranged at intervals around the inner core and is hermetically connected to the main pipe through the first sealing ring. A first flow channel communicating with the branch pipe is formed between the first sealing rings. A second sealing ring is arranged at intervals around the inner core support and is hermetically connected to the inner core through the second sealing ring. A second flow channel is formed between the second sealing rings. The second flow channel communicates with the first flow channel through a diversion hole. The first flow channel and the second flow channel form a flow channel between the branch pipes. When the differential pressure sensing device is in a filtering state, the second sealing ring blocks the flow channel between adjacent branch pipes.

2. The differential pressure sensing device of the filter according to claim 1, wherein The guiding hole communicates with the second water inlet.

3. The differential pressure sensing device of the filter according to claim 1, characterized in that, The main housing includes an upper housing and a lower housing. The first water inlet and the connection port are arranged on the lower housing, and the second water inlet is arranged on the upper housing.

4. A filter, characterized in that, Comprising the differential pressure sensing device according to any one of claims 1 to 3.

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