End caps, filter elements and water purification equipment

Abstract

The present invention discloses an end cover, a filter element and a water purification device, wherein the end cover comprises: an outer cylinder, the outer cylinder comprises a sleeve end, a sealing end, and a connecting section connecting the sleeve end and the sealing end, the sleeve end sleeves a reverse osmosis unit, and the sealing end forms a water through hole; an inner plate, the inner plate is arranged in the outer cylinder and abuts against the end face of the reverse osmosis unit, the inner plate is provided with a center hole opposite to the water through hole, and a wastewater hole away from the center hole; a center tube extends out of the center hole, and the center tube, the inner plate and the outer cylinder are enclosed to form a wastewater channel connected to the wastewater hole. The end cover of the present invention forms a wastewater channel between the outer cylinder, the inner plate and the center tube, that is, the wastewater channel is formed by the cooperation between the end cover itself and the center tube, which not only improves the sealing of the wastewater channel to improve the practicability of the filter element, but also simplifies the assembly structure of the end cover and the filter housing, making the assembly process of the filter element simpler and more convenient, thereby making it easier to achieve the sealing effect of the filter housing and the end cover.

Description

Technical Field

[0001] The invention relates to the field of water purification equipment, and in particular to an end cover, a filter element and water purification equipment. Background Art

[0002] The existing water purification equipment mainly relies on membrane filter elements to filter raw water. When assembling the filter element, the end cover is usually placed on the end face of the reverse osmosis unit, and the water inlet and outlet holes are opened on the end cover, and finally the end cover is sealed with the water flow part of the filter housing. In the prior art, since the end cover is a single plate structure, the end cover needs to be matched with the filter housing to form a wastewater channel, which makes the sealing of the wastewater channel unstable, easily causing wastewater cross-flow, and reducing the practicality of the filter element. Summary of the invention

[0003] The main purpose of the present invention is to provide an end cover, aiming to solve the technical problem of how to improve the practicality of a filter element.

[0004] To achieve the above-mentioned purpose, the end cap proposed in the present invention is applied to a filter element, wherein the filter element comprises a central tube and a reverse osmosis unit surrounding the central tube, the end surface of the reverse osmosis unit forms a wastewater outlet, and the peripheral surface of the reverse osmosis unit forms a pure water outlet, and the end cap is used to cover the end of the reverse osmosis unit, and the end cap comprises:

[0005] An outer cylinder, the outer cylinder comprising a sleeve end, a sealing end, and a connecting section connecting the sleeve end and the sealing end, the sleeve end is sleeved with the reverse osmosis unit, and the sealing end forms a water hole;

[0006] An inner plate is arranged in the outer cylinder and abuts against the end surface of the reverse osmosis unit. The inner plate is provided with a central hole opposite to the water hole and a wastewater hole away from the central hole. The central tube extends out of the central hole. The central tube, the inner plate and the outer cylinder are enclosed to form a wastewater channel connected to the wastewater hole.

[0007] Preferably, the radial dimension of the sealing end is smaller than the radial dimension of the sleeve end.

[0008] Preferably, the radial dimension of the connecting section decreases from the sleeve end toward the sealing end.

[0009] Preferably, a sealing layer is provided on one side of the inner plate abutting against the reverse osmosis unit.

[0010] Preferably, a side of the inner plate abutting against the reverse osmosis unit is provided with ribs protruding therefrom, and the ribs are arranged around the wastewater hole.

[0011] Preferably, the wastewater hole is arranged adjacent to the circumferential surface of the reverse osmosis unit; and / or, there are a plurality of wastewater holes, which are arranged at intervals along the circumference of the inner plate.

[0012] Preferably, the inner plate comprises a fixing ring connected to the outer cylinder, and a center plate detachably connected to the fixing ring, and the wastewater hole is formed between an edge of the center plate and an inner edge of the fixing ring.

[0013] Preferably, a sealing rubber layer is provided on one side of the inner plate abutting against the reverse osmosis unit, the fixing ring is provided with an outer overflow rubber groove adjacent to the inner edge and extending circumferentially, and the center plate is provided with an inner overflow rubber groove adjacent to the edge and extending circumferentially.

[0014] Preferably, the edge of the center plate includes a concave section and / or a convex section, the convex section is fixedly matched with the inner peripheral wall of the fixing ring, and the wastewater hole is formed between the concave section and the fixing ring.

[0015] Preferably, the inner peripheral wall of the fixing ring is convexly provided with positioning ribs, and the edge of the center plate is fixedly matched with the positioning ribs, so that the wastewater hole is formed between the center plate and the fixing ring.

[0016] Preferably, the central hole is sealingly matched with the central tube.

[0017] Preferably, a sealing groove is formed on the outer peripheral wall of the sealing end, and the end cover further comprises a sealing ring embedded in the sealing groove.

[0018] The present invention also proposes a filter element, comprising a filter housing, a central tube, a reverse osmosis unit arranged around the central tube, and an end cover; the end cover comprises: an outer cylinder, the outer cylinder comprises a sleeve end, a sealing end, and a connecting section connecting the sleeve end and the sealing end, the sleeve end is sleeved with the reverse osmosis unit, and the sealing end forms a water passage; an inner plate, the inner plate is arranged in the outer cylinder and abuts against the end face of the reverse osmosis unit, the inner plate is provided with a central hole opposite to the water passage, and a wastewater hole away from the central hole; the central tube extends out of the central hole, and the central tube, the inner plate and the outer cylinder are enclosed to form a wastewater channel connected to the wastewater hole; wherein the filter housing has a water passage, the central tube and the reverse osmosis unit are arranged in the filter housing, the end cover is covered on the end face of the reverse osmosis unit, and the sealing end of the end cover is sealed and matched with the water passage.

[0019] Preferably, the filter element further comprises a sealing cover, the end cover is disposed on one end of the reverse osmosis unit, the end of the central tube away from the end cover is blocked, and the sealing cover is disposed on the other end of the reverse osmosis unit.

[0020] The present invention also provides a water purification device, comprising the filter element as described above.

[0021] The end cap of the present invention forms a wastewater channel between the outer cylinder, the inner plate and the central tube, that is, the wastewater channel is formed by the cooperation between the end cap itself and the central tube, which not only improves the sealing performance of the wastewater channel to improve the practicality of the filter element, but also simplifies the assembly structure of the end cap and the filter housing, making the assembly process of the filter element simpler and more convenient, thereby making it easier to achieve the sealing effect of the filter housing and the end cap. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.

[0023] Figure 1 It is a cross-sectional schematic diagram of an embodiment of a filter element of the present invention;

[0024] Figure 2 It is a structural schematic diagram of an embodiment of an end cover of the present invention;

[0025] Figure 3 It is a cross-sectional schematic diagram of an embodiment of an end cover of the present invention;

[0026] Figure 4 It is an exploded schematic diagram of an embodiment of an end cover of the present invention;

[0027] Figure 5 It is a schematic diagram of the interior of an embodiment of an end cover of the present invention;

[0028] Figure 6 is a cross-sectional schematic diagram of another embodiment of the end cover of the present invention;

[0029] Figure 7 It is an exploded schematic diagram of another embodiment of the end cover of the present invention;

[0030] Figure 8 It is a schematic diagram of the interior of another embodiment of the end cover of the present invention;

[0031] Fig. 9 is a cross-sectional schematic diagram of another embodiment of the end cover of the present invention;

[0032] Fig.10 It is a schematic structural diagram of an embodiment of a sealing cover in the present invention.

[0033] Description of Figure Numbers:

[0034]

[0035]

[0036] The realization of the purpose, functional features and advantages of the present invention will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0037] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0038] It should be noted that if the embodiments of the present invention involve directional indications (such as up, down, left, right, front, back, etc.), the directional indications are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0039] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present invention, the descriptions of "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the meaning of "and / or" appearing in the full text is to include three parallel solutions, taking "A and / or B as an example", including solution A, or solution B, or solutions that satisfy both A and B. In addition, the technical solutions between the various embodiments can be combined with each other, but it must be based on the ability of ordinary technicians in the field to implement. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0040] The present invention proposes an end cap, which is applied to a filter element. The filter element includes a central tube 10 and a reverse osmosis unit 20 surrounding the central tube 10. The end face of the reverse osmosis unit 20 forms a wastewater outlet, and the peripheral surface of the reverse osmosis unit 20 forms a pure water outlet. The end cap is used to cover the end of the reverse osmosis unit 20.

[0041] In the embodiment of the present invention, Figures 1 to 10 As shown, the end cap comprises:

[0042] The outer cylinder 30 includes a sleeve end 31, a sealing end 32, and a connecting section 33 connecting the sleeve end 31 and the sealing end 32. The sleeve end 31 is sleeved with the reverse osmosis unit 20, and the sealing end 32 forms a water hole 322;

[0043] The inner plate 40 is arranged in the outer cylinder 30 and abuts against the end surface of the reverse osmosis unit 20. The inner plate 40 is provided with a central hole 41 opposite to the water hole 322, and a wastewater hole 42 away from the central hole 41; the central tube 10 extends out of the central hole 41, and the central tube 10, the inner plate 40 and the outer cylinder 30 are surrounded to form a wastewater channel 43 connected with the wastewater hole 42.

[0044] In this embodiment, one end or both ends of the center hole 41 form a raw water inlet hole, and the peripheral wall of the center tube 10 is provided with a raw water outlet hole. The reverse osmosis unit 20 is formed by winding a reverse osmosis membrane on the center tube 10, and the two water inlet surfaces of the reverse osmosis membrane form a raw water flow channel, and the two water outlet surfaces of the reverse osmosis membrane form a pure water flow channel. By gluing the water outlet surface of the reverse osmosis membrane at the two ends of the reverse osmosis unit 20, the water outlet of the pure water flow channel, i.e., the pure water outlet, can be formed on the peripheral surface of the reverse osmosis unit 20. Correspondingly, by gluing the two water inlet surfaces of the reverse osmosis membrane at the position of the peripheral surface of the reverse osmosis unit 20, the water outlet of the raw water flow channel, i.e., the waste water outlet, can be formed on the end surface of the reverse osmosis unit 20. The end cover can cover one end of the reverse osmosis unit 20, or can cover both ends of the reverse osmosis unit 20. Here, covering one end of the reverse osmosis unit 20 is taken as an example.

[0045] The sealing end 32 is used to seal with the water outlet of the filter housing. The sleeve end 31 sleeves one end of the reverse osmosis unit 20, and the inner plate 40 abuts against the end face of the reverse osmosis unit 20, so that the inner plate 40 can block most of the wastewater outlets. The central tube 10 extends out of the central hole 41 and extends to be flush with the edge of the water outlet 322, so that the central tube 10, the outer cylinder 30 and the inner plate 40 can enclose and form a wastewater channel 43 connected to the water outlet 322. It can be understood that the wastewater channel 43 is arranged around the central tube 10. The wastewater hole 42 is away from the central hole 41, so that the wastewater outlet of the reverse osmosis unit 20 can be arranged adjacent to the circumference of the reverse osmosis unit 20, so as to extend the flow path of the raw water in the reverse osmosis unit 20 and improve the recovery rate of pure water. The wastewater hole 42 is connected to the wastewater channel 43, and the wastewater generated by the reverse osmosis unit 20 flows from the wastewater hole 42 through the wastewater channel 43 and finally flows out from the water outlet 322. The raw water enters the central tube 10 from the water holes 322 . Therefore, the raw water and the waste water share different parts of the water holes 322 to enter and exit the reverse osmosis unit 20 .

[0046] Since the wastewater channel 43 is formed in the end cover, the filter housing only needs to be sealed with the sealing end 32 without reserving a gap. Compared with the wastewater channel 43 formed by the filter housing and the end cover, the wastewater channel 43 formed by the end cover's own structure is more reliable and has a better sealing effect. It will not cause wastewater to flow to other locations due to assembly errors between the filter housing and the end cover, thereby improving the practicality of the filter element. In addition, there is no need to set a limiting structure in the filter housing to form the wastewater channel 43, which simplifies the structure of the filter housing and makes the assembly process of the filter housing and the end cover simpler and more convenient.

[0047] The end cap of the present invention forms a wastewater channel 43 between the outer cylinder 30, the inner plate 40 and the central tube 10, that is, the wastewater channel 43 is formed by the cooperation between the end cap itself and the central tube 10, which not only improves the sealing performance of the wastewater channel 43 to improve the practicality of the filter element, but also simplifies the assembly structure of the end cap and the filter housing, making the assembly process of the filter element simpler and more convenient, thereby making it easier to achieve the sealing effect between the filter housing and the end cap.

[0048] In one embodiment, if Figure 1 As shown, the radial dimension of the sealing end 32 is smaller than the radial dimension of the sleeve end 31. In this embodiment, the radial dimension of the sealing end 32 is smaller than the radial dimension of the sleeve end 31, so that the matching area between the sealing end 32 and the water inlet of the filter housing can be reduced to improve the sealing effect of the matching.

[0049] Specifically, Figure 1 As shown, the radial dimension of the connecting section 33 decreases from the sleeve end 31 toward the sealing end 32. In this embodiment, the radial dimension of the connecting section 33 decreases toward the water inlet of the filter housing, which can reduce the overall volume of the outer cylinder 30, thereby reducing the space occupied by the outer cylinder 30 in the filter housing and improving the internal space utilization of the filter housing.

[0050] In practical applications, a sealing layer is provided on one side of the inner plate 40 that abuts against the reverse osmosis unit 20. In this embodiment, when assembling the end cap and the reverse osmosis unit 20, the sealing layer can be pre-coated on the inner plate 40, so that after the inner plate 40 overlaps the end face of the reverse osmosis unit 20, most of the open ends of the reverse osmosis unit 20 can be glued, leaving only the wastewater outlet corresponding to the wastewater hole 42, thereby improving the sealing effect of the end cap on the end face of the reverse osmosis unit 20.

[0051] In one embodiment, if Figure 2 As shown, the inner plate 40 is provided with a rib 44 protruding from one side of the reverse osmosis unit 20, and the rib 44 is arranged around the wastewater hole 42. In this embodiment, the rib 44 is adjacent to the wastewater hole 42 and extends along the circumference of the wastewater hole 42, thereby preventing the sealant layer from flowing to block the wastewater hole 42, so as to keep the wastewater channel 43 unobstructed and improve the stability of the end cover.

[0052] Specifically, Figure 2 As shown, the wastewater hole 42 is arranged adjacent to the circumference of the reverse osmosis unit 20; and / or, the number of the wastewater holes 42 is multiple, and the multiple wastewater holes 42 are arranged at intervals along the circumference of the inner plate 40. In this embodiment, the wastewater hole 42 is adjacent to the circumference of the reverse osmosis unit 20, so that the wastewater port formed on the end face of the reverse osmosis unit 20 can also be adjacent to the circumference of the reverse osmosis unit 20, so as to extend the flow path of the raw water in the reverse osmosis unit 20 and improve the recovery rate of pure water. The wastewater hole 42 can be arranged in an arc-shaped hole extending along the circumference of the inner plate 40 to adapt to the spirally extended raw water flow channel and improve the water discharge efficiency of the wastewater hole 42. The number of the wastewater holes 42 is multiple and is arranged at intervals along the circumference of the inner plate 40, so that the wastewater can flow to the wastewater channel 43 faster to improve the drainage efficiency of the wastewater.

[0053] In one embodiment, if Figures 4 to 9 As shown, the inner plate 40 includes a fixing ring 45 connected to the outer cylinder 30, and a center plate 46 detachably connected to the fixing ring 45, and the waste water hole 42 is formed between the edge of the center plate 46 and the inner edge of the fixing ring 45. In this embodiment, the fixing ring 45 can be integrally formed with the outer cylinder 30, and the center hole 41 is opened in the middle of the center plate 46. The edge of the center plate 46 is required to be fixedly matched with the fixing ring 45 and to form the waste water hole 42 between the fixing ring 45. For example, the edge of the center plate 46 includes adjacent concave and convex parts, the convex part is used to abut and cooperate with the fixing ring 45, and the concave part is used to form the waste water hole 42 between the fixing ring 45. The inner plate 40 is provided in a split form, so that when the end cover and the reverse osmosis unit 20 are assembled, the center plate 46 can be firmly pressed onto the end surface of the reverse osmosis unit 20 first, and then the outer cylinder 30 can be integrally pressed onto the outer side of the center plate 46 at the pressing ring. In this way, the inner plate 40 as a whole can effectively block the end surface of the reverse osmosis unit 20, avoiding the situation that part of the end surface of the reverse osmosis unit 20 cannot be effectively blocked due to uneven force, so as to improve the sealing effect after the end cover and the reverse osmosis unit 20 are assembled.

[0054] Specifically, Figure 4 and Figure 5 As shown, the inner plate 40 is provided with a sealing rubber layer on one side abutting against the reverse osmosis unit 20, the fixing ring 45 is provided with an overflow rubber groove 451 adjacent to the inner edge and extending in the circumferential direction, and the center plate 46 is provided with an inner overflow rubber groove 461 adjacent to the edge and extending in the circumferential direction. In this embodiment, the overflow rubber groove 451 extends along the inner edge of the fixing ring 45, and the inner overflow rubber groove 461 extends along the edge of the center plate 46, so that the overflow rubber groove 451 and the inner overflow rubber groove 461 can jointly enclose the wastewater hole 42 between the fixing ring 45 and the center plate 46, preventing the sealing rubber layer from flowing to block the wastewater hole 42, so as to keep the wastewater channel 43 unobstructed and improve the stability of the end cover.

[0055] In one embodiment, if Figures 4 to 6 As shown, the edge of the center plate 46 includes a concave section 462 and / or a convex section 463, and the convex section 463 is fixedly matched with the inner peripheral wall of the fixing ring 45, and the waste water hole 42 is formed between the concave section 462 and the fixing ring 45. In this embodiment, the concave section 462 and the convex section 463 are both arranged in arc sections, and the concave sections 462 and the convex sections 463 are adjacent to each other, so that a plurality of waste water holes 42 extending along the circumference of the inner plate 40 can be formed between the fixing ring 45 and the center plate 46, and at the same time, the matching position and matching area of ​​the fixing ring 45 and the center plate 46 can be increased to improve the assembly stability of the fixing ring 45 and the center plate 46.

[0056] In another embodiment, if Figures 7 to 9 As shown, the inner peripheral wall of the fixing ring 45 is provided with a convex positioning rib 452, and the edge of the center plate 46 is fixedly matched with the positioning rib 452, so that the waste water hole 42 is formed between the center plate 46 and the fixing ring 45. In this embodiment, the positioning rib 452 extends along the radial direction of the fixing ring 45, and the edge of the center plate 46 abuts against the end of the positioning rib 452, so that the center plate 46 and the fixing ring 45 can be relatively fixed, and the waste water hole 42 can be formed between the center plate 46 and the fixing ring 45. The number of the positioning ribs 452 is multiple and they are arranged at intervals along the circumference of the fixing ring 45 to increase the matching area with the center plate 46 and enhance the matching strength, and at the same time, multiple waste water holes 42 extending along the circumference of the inner plate 40 can be formed between the fixing ring 45 and the center plate 46.

[0057] Specifically, the center hole 41 is sealed with the center tube 10. In this embodiment, the center hole 41 and the center tube 10 can be sealed with each other through a sealing ring 50. For example, the hole wall of the center hole 41 is provided with an embedding groove extending in the circumferential direction, and the sealing ring 50 is embedded in the embedding groove, so that the center hole 41 and the center tube 10 can be sealed with each other, thereby avoiding the waste caused by the raw water flowing into the wastewater flow channel and improving the practicality of the end cover.

[0058] In practical applications, such as Figure 1 and Fig. 9 As shown, the outer peripheral wall of the sealing end 32 is provided with a sealing groove 321, and the end cover further comprises a sealing ring 50 embedded in the sealing groove 321. In this embodiment, the sealing ring 50 can realize the sealing cooperation between the sealing end 32 of the outer cylinder 30 and the water inlet of the filter housing to prevent water leakage of the filter element and improve the practicality of the filter element.

[0059] The present invention also proposes a filter element, which includes a filter housing, a central tube 10, a reverse osmosis unit 20 arranged around the central tube 10, and an end cover. The specific structure of the end cover refers to the above embodiment. Since the filter element adopts all the technical solutions of all the above embodiments, it at least has all the beneficial effects brought by the technical solutions of the above embodiments, which will not be repeated here. Among them, the filter housing has a water inlet, the central tube 10 and the reverse osmosis unit 20 are arranged in the filter housing, the end cover is covered on the end face of the reverse osmosis unit 20, and the sealing end 32 of the end cover is sealed with the water inlet.

[0060] In this embodiment, pure water can remain in the filter housing after flowing out from the peripheral surface of the reverse osmosis unit 20, so that the user can take it through the water intake hole. Wastewater can flow out of the filter housing directly from the water hole 322, so that the pure water and wastewater produced by the reverse osmosis unit 20 can be separated faster and more effectively. In addition, when the water purification equipment is shut down, since only the central tube 10 and the water inlet flow channel have raw water or wastewater, that is, there is less raw water or wastewater for ion exchange with pure water, and thus less soluble impurities diffused to the pure water flow channel or the outside of the reverse osmosis unit 20, after the water purification equipment is operated again, the first cup of pure water obtained by the user has a lower content of soluble impurities, which effectively improves the purity of the first cup of water, so as to improve the user experience and the practicality of the water purification equipment.

[0061] Specifically, Fig.10 As shown, the filter element further includes a sealing cover 60, the end cover is covered at one end of the reverse osmosis unit 20, the end of the central tube 10 away from the end cover is blocked, and the sealing cover 60 is covered at the other end of the reverse osmosis unit 20. In this embodiment, the sealing cover 60 includes a cover plate and a mounting cylinder, the mounting cylinder is arranged around one end of the reverse osmosis unit 20, the cover plate covers the end face of the reverse osmosis unit 20, and the cover plate can be provided with a sealing rubber layer, so that the end face of the reverse osmosis unit 20 away from the end cover can be completely sealed, so that the wastewater can flow toward the end face where the end cover is located.

[0062] In practical applications, a plug-in space can be formed between the sealing position of the central tube 10 and the port of the central tube 10, and the sealing cover 60 can be provided with a plug-in column, which is plugged into the plug-in space, thereby improving the assembly strength of the sealing cover 60 and the reverse osmosis unit 20 to improve the overall stability of the filter element.

[0063] The above description is only a preferred embodiment of the present invention, and does not limit the patent scope of the present invention. All equivalent structural changes made by using the contents of the present invention specification and drawings under the inventive concept of the present invention, or directly / indirectly applied in other related technical fields are included in the patent protection scope of the present invention.

Claims

1. An end cap, applied to a filter element, the filter element comprising a central tube and a reverse osmosis unit surrounding the central tube, the end surface of the reverse osmosis unit forming a wastewater outlet, the peripheral surface of the reverse osmosis unit forming a pure water outlet, the end cap is used to cover the end of the reverse osmosis unit, characterized in that: The end cap comprises: An outer cylinder, the outer cylinder comprising a sleeve end, a sealing end, and a connecting section connecting the sleeve end and the sealing end, the sleeve end is sleeved with the reverse osmosis unit, and the sealing end forms a water hole; An inner plate, the inner plate is arranged in the outer cylinder and abuts against the end surface of the reverse osmosis unit, the inner plate is provided with a central hole opposite to the water hole, and a wastewater hole away from the central hole; the central tube extends out of the central hole, and the central tube, the inner plate and the outer cylinder are enclosed to form a wastewater channel connected to the wastewater hole; The inner plate includes a fixing ring connected to the outer cylinder, and a center plate detachably connected to the fixing ring, the center hole is opened in the middle of the center plate, the wastewater hole is formed between the edge of the center plate and the inner edge of the fixing ring, and the edge of the center plate is fixedly matched with the fixing ring.

2. The end cap according to claim 1, characterized in that: The radial dimension of the sealing end is smaller than the radial dimension of the sleeve end.

3. The end cap according to claim 2, characterized in that: The radial dimension of the connecting section is gradually reduced from the sleeve end toward the sealing end.

4. The end cap according to claim 1, characterized in that: A sealing layer is provided on one side of the inner plate abutting against the reverse osmosis unit.

5. The end cap according to claim 4, characterized in that: A side of the inner plate that abuts against the reverse osmosis unit is protruded with a rib, and the rib is arranged around the wastewater hole.

6. The end cap according to claim 1, characterized in that: The wastewater hole is arranged adjacent to the circumferential surface of the reverse osmosis unit; and / or, there are a plurality of wastewater holes, and the plurality of wastewater holes are arranged at intervals along the circumference of the inner plate.

7. The end cap according to claim 1, characterized in that: The inner plate is provided with a sealing rubber layer on one side abutting against the reverse osmosis unit, the fixing ring is provided with an overflow rubber groove adjacent to the inner edge and extending circumferentially, and the center plate is provided with an overflow rubber groove adjacent to the edge and extending circumferentially.

8. The end cap according to claim 1, characterized in that: The edge of the center plate includes a concave section and / or a convex section, the convex section is fixedly matched with the inner peripheral wall of the fixing ring, and the wastewater hole is formed between the concave section and the fixing ring.

9. The end cap according to claim 1, characterized in that: The inner peripheral wall of the fixing ring is convexly provided with positioning ribs, and the edge of the center plate is fixedly matched with the positioning ribs, so that the wastewater hole is formed between the center plate and the fixing ring.

10. The end cap according to claim 1, characterized in that The center hole is sealingly matched with the center tube.

11. The end cap according to claim 1, characterized in that: The outer peripheral wall of the sealing end is provided with a sealing groove, and the end cover further comprises a sealing ring embedded in the sealing groove.

12. A filter element, characterized in that: It comprises a filter housing, a central tube, a reverse osmosis unit arranged around the central tube, and an end cover as described in any one of claims 1 to 11; the filter housing has a water outlet, the central tube and the reverse osmosis unit are arranged in the filter housing, the end cover is arranged on the end face of the reverse osmosis unit, and the sealing end of the end cover is sealed with the water outlet.

13. The filter element according to claim 12, characterized in that The filter element further comprises a sealing cover, wherein the end cover is disposed on one end of the reverse osmosis unit, the end of the central tube away from the end cover is blocked, and the sealing cover is disposed on the other end of the reverse osmosis unit.

14. A water purification device, characterized in that: Comprising a filter element as described in claim 12 or 13.

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