Needle filter

Abstract

The utility model belongs to filter equipment technical field provides a needle filter, include: upper casing, including the liquid inlet pipe and upper casing disc that are connected, the edge of upper casing disc is equipped with a plurality of through -hole that passes through upper casing disc, lower casing, including the liquid outlet pipe and lower casing disc that are connected, edge structure, the circumferential of upper casing disc and lower casing disc is covered, to carry out sealed connection to upper casing and lower casing, when upper casing and lower casing assembly, upper casing disc cover is covered on lower casing disc, the circumferential of upper casing disc and lower casing disc is poured to form the edge structure through the pouring process, the edge structure at least partial access to the through -hole, and after forming, the card is established in the through -hole, the edge structure of the utility model can bear higher pressure, avoid in the use process too high pressure leads to filter membrane breakage, and when the liquid inlet pipe liquid, can increase burst pressure, improve liquid flow rate.

Description

Technical Field

[0001] This utility model relates to the field of filtration equipment technology, and in particular to a needle filter. Background Technology

[0002] Needle filters, also known as syringe filters, are single-use filter cartridges commonly used in high-performance liquid chromatography (HPLC), ion chromatography, or dissolution tests to remove particulates from the liquids used in sample preparation. In other cases, syringe filters can also be attached to a syringe to remove particulates during subcutaneous injection.

[0003] Existing filters suffer from low and unstable flow rates, and are sometimes impossible to push manually with a syringe. Furthermore, the special connection between the upper and lower shells in the production process leads to low assembly efficiency, hindering automation for large-scale production. Current designs also suffer from excessive pressure during use, causing damage to the intermediate filter membrane, resulting in products without bubble points and inconsistent product appearance. In addition, needle filters typically have low burst pressure, leading to filter failure and potentially reducing the integrity of analytical results.

[0004] Therefore, there is a need for syringe filter designs that are suitable for more cost-effective manufacturing and reduce clogging and / or filter failure. Utility Model Content

[0005] This invention provides a needle filter to solve the technical problems of low flow rate, high pressure, easy membrane damage and instability in existing needle filters.

[0006] This utility model provides a needle filter, the needle filter comprising:

[0007] The upper housing includes a liquid inlet pipe and an upper housing plate connected to each other, and the edge of the upper housing plate is provided with a plurality of through holes penetrating the upper housing plate;

[0008] The lower housing includes a liquid outlet pipe and a lower housing plate connected together;

[0009] An edge-sealing structure covers the circumference of the upper and lower shells to provide a sealed connection between the upper and lower shells.

[0010] When the upper shell and the lower shell are assembled, the upper shell plate covers the lower shell plate. The upper shell plate and the lower shell plate are cast circumferentially by a casting process to form the edge-wrapping structure. The edge-wrapping structure enters at least part of the through hole and is locked in the through hole after forming.

[0011] In one embodiment of this utility model, the upper shell plate is provided with a flow channel ring on the side opposite to the liquid inlet pipe. The flow channel ring surrounds the circumference of the liquid inlet to form an upper chamber communicating with the pipe hole of the liquid inlet pipe. Multiple baffles and cross baffles are provided in the upper chamber. The ends of the cross baffles are all connected to the flow channel ring. The center of the cross baffle corresponds to the center of the pipe hole of the liquid inlet pipe. One end of each baffle is connected to the flow channel ring, and the other end extends radially toward the pipe hole of the liquid inlet pipe and is spaced apart from the pipe hole of the liquid inlet pipe. The multiple baffles and cross baffles divide the upper chamber into multiple flow channels. The multiple flow channels are distributed radially with the pipe hole of the liquid inlet pipe as the center.

[0012] In one embodiment of the present invention, a circular baffle is provided at the center of the cross baffle, and the baffle and the cross baffle are integrally connected or separately connected.

[0013] In one embodiment of the present invention, the outer diameter of the upper shell plate is larger than the outer diameter of the flow channel ring. The upper shell plate is also provided with a plurality of buckles on the side away from the liquid inlet pipe. The plurality of buckles are evenly distributed along the circumference of the flow channel ring. The top of each buckle is connected to the upper shell plate. Each buckle has a snap-fit ​​protrusion on the side near the flow channel ring. The snap-fit ​​protrusion is located near the bottom of the buckle.

[0014] In one embodiment of the present invention, the lower shell plate has an installation groove for installing a filter membrane on the side opposite to the liquid outlet pipe. The bottom of the installation groove has a lower chamber communicating with the pipe hole of the liquid outlet pipe. The lower chamber is provided with a plurality of arc-shaped protrusions. The plurality of arc-shaped protrusions are distributed concentrically with the pipe hole of the liquid outlet pipe as the center, and form a plurality of annular grooves and radial grooves. The plurality of annular grooves are connected to each other through the radial grooves. The plurality of radial grooves are connected to the pipe hole of the liquid outlet pipe and are distributed radially with the pipe hole of the liquid outlet pipe as the center.

[0015] In one embodiment of the present invention, a first baffle and a second baffle are further provided in the middle of the lower chamber. The first baffle blocks the pipe hole of the liquid outlet pipe to divert the liquid entering the liquid outlet pipe. At least two second baffles are provided, which are arranged circumferentially along the pipe hole of the liquid outlet pipe and are respectively located on both sides of the first baffle.

[0016] In one embodiment of the present invention, the lower housing is provided with a flange structure along the circumference of the mounting groove. The snap-fit ​​protrusion and the bottom of the buckle are connected by a guide surface. When the upper housing and the lower housing are installed, the guide surface provides guidance for the flange structure. After passing the snap-fit ​​protrusion, the flange structure abuts against the side of the buckle. The snap-fit ​​protrusion blocks the exit direction of the flange structure.

[0017] In one embodiment of the present invention, the flange structure is further provided with a plurality of limiting bosses, which are evenly distributed on the flange structure along the circumference of the mounting groove.

[0018] In one embodiment of the present invention, one end of the liquid inlet pipe is connected to the lower shell plate, and the other end is a free end, wherein the free end of the liquid inlet pipe has a snap-fit ​​structure in the circumferential direction.

[0019] In one embodiment of the present invention, the liquid outlet tube has a first section and a second section connected to each other. Both the first section and the second section are tapered tube structures. The diameters of the first section and the second section decrease from top to bottom. The diameter of the smaller diameter end of the first section is larger than the diameter of the larger diameter end of the second section.

[0020] The beneficial effects of this utility model are as follows: The needle filter proposed in this utility model first assembles an upper shell and a lower shell, with the upper shell plate covering the lower shell plate. The entire needle filter is then placed into a casting mold, and a circumferential edge structure is formed on the upper and lower shell plates through a casting process. During the casting process, at least part of the edge structure enters the through hole. After casting, at least part of the edge structure is locked in the through hole, ensuring that the edge structure can tightly fit the upper and lower shell plates circumferentially, achieving a sealed connection between the upper and lower shell plates. This results in higher pressure resistance, as the edge structure can withstand higher pressure, preventing excessive pressure from damaging the filter membrane during use. Furthermore, it increases the burst pressure and improves the inlet flow rate when liquid is introduced through the inlet pipe. Attached Figure Description

[0021] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application. It is obvious that the drawings described below are merely some embodiments of this application, and those skilled in the art can obtain other drawings based on these drawings without any inventive effort.

[0022] In the attached diagram:

[0023] Figure 1 This is a schematic diagram of the structure of a needle filter provided in an embodiment of the present invention;

[0024] Figure 2 This is an assembly diagram of the upper and lower housings provided in an embodiment of the present utility model;

[0025] Figure 3 This is a schematic diagram of the upper shell provided in an embodiment of the present utility model;

[0026] Figure 4This is a schematic diagram of the structure of the lower shell provided in an embodiment of the present utility model;

[0027] Figure 5 This is a partially enlarged structural diagram of the upper and lower shells after assembly, according to an embodiment of the present invention.

[0028] The attached figures are labeled as follows:

[0029] 1-Inlet pipe; 2-Upper shell plate; 3-Outlet pipe; 4-Snap-fit ​​structure; 5-Edge wrapping structure; 6-Snap fastener; 7-First section; 8-Second section; 9-Through hole; 10-Flow channel ring; 11-Upper chamber; 12-Baffle; 13-Cross baffle; 14-Baffle plate; 15-Flow channel; 16-Mounting groove; 17-Lower chamber; 18-Arched protrusion; 19-Annular groove; 20-Radial groove; 21-First stop block; 22-Second stop block; 23-Limiting boss; 24-Lower shell plate; 25-Flange structure; 26-Snap-fit ​​protrusion; 27-Guide surface. Detailed Implementation

[0030] The following specific examples illustrate the implementation of this utility model. Those skilled in the art can easily understand other advantages and effects of this utility model from the content disclosed in this specification. This utility model can also be implemented or applied through other different specific embodiments. Various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of this utility model. In the absence of conflict, the following embodiments and features in the embodiments can be combined with each other.

[0031] It should be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of the present invention. The drawings only show the components related to the present invention and are not drawn according to the actual number, shape and size of the components. In actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0032] In the following description, numerous details are explored to provide a more thorough explanation of embodiments of the present invention. However, it will be apparent to those skilled in the art that embodiments of the present invention may be practiced without these specific details. In other embodiments, well-known structures and devices are shown in block diagram form rather than in detail to avoid obscuring embodiments of the present invention.

[0033] Please see Figures 1 to 5 This utility model provides an exemplary needle filter, comprising:

[0034] The upper shell includes a liquid inlet pipe 1 and an upper shell plate 2 connected to each other. Multiple through holes 9 are provided on the edge of the upper shell plate 2.

[0035] The lower housing includes a liquid outlet pipe 3 and a lower housing plate 24 connected to it;

[0036] The edge-sealing structure 5 covers the circumference of the upper shell plate 2 and the lower shell plate 24 to provide a sealed connection between the upper shell and the lower shell.

[0037] When the upper shell and the lower shell are assembled, the upper shell plate 2 covers the lower shell plate 24. The upper shell plate 2 and the lower shell plate 24 are cast in the circumference through a casting process to form a edging structure 5. The edging structure 5 enters at least part of the through hole 9 and is locked in the through hole 9 after forming.

[0038] It should be noted that the existing needle filter has a circular flow channel in the upper shell. This flow channel structure restricts the inlet flow rate during liquid introduction, resulting in uneven liquid distribution within the chamber. The liquid cannot quickly fill the chamber, leading to higher inlet flow rates at some locations and lower filtration flow rates at others. This results in unstable overall filtration flow rates and reduced flow rates. Furthermore, when connected to a syringe, the uneven liquid distribution and unstable flow rate can cause the syringe to fail to move. Additionally, the existing needle filter has low burst pressure and uneven liquid distribution, which can generate excessive pressure during use, potentially damaging the filter membrane and causing a lack of bubble points. This can reduce the integrity of analytical results. Moreover, the existing needle filter requires precise alignment of the upper and lower shells during production, making assembly cumbersome and inefficient, hindering automated mass production.

[0039] In the needle filter provided in this embodiment, the upper shell and the lower shell are first assembled, with the upper shell plate 2 covering the lower shell plate 24. The entire needle filter is then placed into a casting mold, and a circumferential edge structure 5 is formed on the upper shell plate 2 and the lower shell plate 24 through a casting process. During the casting process, the circumferential edge structure 5 is at least partially inserted into the through hole 9. After casting, the circumferential edge structure 5 is at least partially locked in the through hole 9, ensuring that the circumferential edge structure 5 can fit tightly against the upper shell plate 2 and the lower shell plate 24, achieving a sealed connection between the upper shell and the lower shell, thereby achieving a higher pressure resistance. The circumferential edge structure 5 can withstand higher pressure, avoiding excessive pressure during use that could cause filter membrane damage. Furthermore, when liquid is introduced into the liquid inlet pipe 1, it can increase the burst pressure and improve the liquid inlet flow rate.

[0040] In this embodiment, the upper shell plate 2 is provided with a flow channel ring 10 on the side opposite to the liquid inlet pipe 1. The flow channel ring 10 surrounds the circumference of the liquid inlet to form an upper chamber 11 that communicates with the pipe hole of the liquid inlet pipe 1. Multiple baffles 12 are provided in the upper chamber 11. One end of each baffle 12 is connected to the flow channel ring 10, and the other end extends radially toward the pipe hole of the liquid inlet pipe 1 and is spaced apart from the pipe hole of the liquid inlet pipe 1. The multiple baffles 12 divide the upper chamber 11 into multiple flow channels 15, and the multiple flow channels 15 are distributed radially with the pipe hole of the liquid inlet pipe 1 as the center.

[0041] In detail, a cross baffle 13 is also provided in the upper chamber 11. The ends of the cross baffle 13 are all connected to the flow channel ring 10. The center of the cross baffle 13 corresponds to the center of the pipe hole of the liquid inlet pipe 1. The cross baffle 13 divides the upper chamber 11 into multiple independent spaces, and the number of baffles 12 distributed in each space is the same. Specifically, a flow channel 15 can also be formed between the cross baffle 13 and the adjacent baffle 12. When liquid enters the upper chamber 11 from the liquid inlet pipe 1, the liquid can be evenly distributed to each space. Since the flow channel 15 distributed in each space has the same structure, the flow rate of the liquid distributed to the flow channel 15 in each space is the same, ensuring that the liquid inlet flow rate at each position in the upper chamber 11 is uniform, and the liquid can quickly fill the upper chamber 11.

[0042] In the above embodiment, a circular baffle 14 is provided at the center of the cross baffle 13. The baffle 14 and the cross baffle 13 are connected as one piece or separately. Specifically, the center of the baffle 14 corresponds to the center of the pipe hole of the liquid inlet pipe 1. When the liquid inlet flow rate of the liquid inlet pipe 1 is large, the baffle 14 shares the liquid inlet pressure to prevent the impact pressure of the liquid inlet from being too high and causing damage to the filter membrane.

[0043] In some embodiments, the outer diameter of the upper shell plate 2 is larger than the outer diameter of the flow channel ring 10. The upper shell plate 2 is also provided with a plurality of snap fasteners 6 on the side away from the liquid inlet pipe 1. The plurality of snap fasteners 6 are evenly distributed along the circumference of the flow channel ring 10. The top of each snap fastener 6 is connected to the upper shell plate 2. Each snap fastener 6 has a snap-fit ​​protrusion 26 on the side near the flow channel ring 10. The snap-fit ​​protrusion 26 is located near the bottom of the snap fastener 6. Specifically, each snap fastener 6 is integrally connected to the upper shell plate 2. The snap-fit ​​protrusion 26 protrudes from the side of the snap fastener 6 near the flow channel ring 10.

[0044] In this embodiment, the lower shell plate 24 has an installation groove 16 for installing a filter membrane on the side opposite to the liquid outlet pipe 3. The bottom of the installation groove 16 has a lower chamber 17 that communicates with the pipe hole of the liquid outlet pipe 3. The lower chamber 17 has a plurality of arc-shaped protrusions 18. The plurality of arc-shaped protrusions 18 are distributed concentrically with the pipe hole of the liquid outlet pipe 3 as the center, and form a plurality of annular grooves 19 and radial grooves 20. The plurality of annular grooves 19 are connected to each other through radial grooves 20. The plurality of radial grooves 20 are connected to the pipe hole of the liquid outlet pipe 3 and are distributed radially with the pipe hole of the liquid outlet pipe 3 as the center.

[0045] In detail, the lower housing 24 is provided with a flange structure 25 around the mounting groove 16. The bottom of the snap-fit ​​protrusion 26 and the buckle 6 are connected by a guide surface 27. When the upper and lower housings are installed, the guide surface 27 provides guidance for the flange structure 25. After passing the snap-fit ​​protrusion 26, the flange structure 25 abuts against the side of the buckle 6. The snap-fit ​​protrusion 26 blocks the exit direction of the flange structure 25. When the upper and lower housings are installed, the filter membrane is first placed on the lower chamber 17. Multiple arc-shaped protrusions 18 contact the filter membrane and support the bottom of the filter membrane. The upper housing moves towards the lower housing. During the process of the flow channel ring 10 extending into the mounting groove 16, the guide surface 27 of the snap-fit ​​protrusion 26 first contacts the flange structure 25 for guidance. Then the flange structure 25 and each The side of the buckle 6 is pressed against the upper housing, and the upper housing continues to move until the flow channel ring 10 contacts and fits against the bottom of the mounting groove 16. At this time, multiple baffles 12 and cross baffles 13 in the upper chamber 11 contact the filter membrane and support the top of the filter membrane. Since the diameter of the filter membrane is larger than the diameter of the upper chamber 11 and the lower chamber 17, the flow channel ring 10 and the mounting groove 16 press the edge of the filter membrane tightly. The upper housing plate 2 clamps the flange structure 25 of the lower housing plate 24 through multiple buckles 6, completing the installation connection of the upper housing and the lower housing. When installing the upper housing and the lower housing, through the cooperation of the buckles 6 and the flange structure 25, it is only necessary to press down the upper housing, and the buckles 6 will automatically clamp the flange structure 25, simplifying the assembly steps, improving production efficiency, realizing automated assembly operations, and facilitating automated production of products.

[0046] Furthermore, the flange structure 25 is also provided with multiple limiting bosses 23. The multiple limiting bosses 23 are evenly distributed on the flange structure 25 along the circumference of the mounting groove 16. When the flow channel ring 10 contacts and fits with the bottom of the mounting groove 16, the limiting bosses 23 are in contact with the upper shell plate 2. The limiting bosses 23 can restrict the upper shell from continuing to move, and at the same time provide support for the upper shell plate 2, so as to avoid the flow channel ring 10 and the mounting groove 16 being over-pressed, causing the filter membrane to be installed in place.

[0047] In some embodiments, one end of the inlet pipe 1 is connected to the lower shell plate 24, and the other end is a free end. The free end of the inlet pipe 1 has a snap-fit ​​structure 4 in the circumferential direction, and the inlet pipe 1 of the upper shell is connected to the inlet device through the snap-fit ​​structure 4.

[0048] In this embodiment, the edge-sealing structure 5 is made of rubber. After the upper and lower shells are assembled, the needle filter is placed into the casting mold and formed into the edge-sealing structure 5 through the casting process. The edge-sealing structure 5 covers the circumference of the upper shell plate 2 and the lower shell plate 24. At the same time, during casting, the edge-sealing structure 5 is at least partially inserted into the through hole 9 and is stuck in the through hole 9 after forming. This ensures that the edge-sealing structure 5 can fit tightly against the circumference of the upper shell plate 2 and the lower shell plate 24, achieving a sealed connection between the upper and lower shells and achieving a high pressure resistance. When liquid is introduced into the liquid inlet pipe 1, it can increase the burst pressure and increase the liquid inlet flow rate, allowing the liquid to quickly fill the upper chamber 11.

[0049] In one embodiment, a sealing ring is also provided on the mounting groove 16. When the flow channel ring 10 contacts the mounting groove 16, there is a certain gap between the flow channel ring 10 and the mounting groove 16, forming an annular space. The sealing ring fills the annular space to seal the upper chamber 11 and the lower chamber 17 along the circumference of the flow channel ring 10. When the edging structure 5 is cast, the sealing ring can prevent the casting material of the edging structure 5 from entering the upper chamber 11 and the lower chamber 17.

[0050] In this embodiment, a first baffle 21 and a second baffle 22 are also provided in the middle of the lower chamber 17. The first baffle 21 blocks the outlet pipe 3 at its opening to divert the liquid entering the outlet pipe 3. At least two second baffles 22 are provided, arranged circumferentially along the outlet pipe 3 and located on both sides of the first baffle 21. Specifically, multiple arc-shaped grooves and multiple radial grooves 20 are spliced ​​to form a multi-ring annular groove centered on the outlet pipe 3. The diameter of the multi-ring annular groove gradually increases towards the direction away from the outlet pipe 3. The liquid in the upper chamber 11 is diverted through... After filtration, the liquid enters the lower chamber 17 and is evenly distributed into each annular groove 19. Finally, it flows along each radial groove 20 to the outlet pipe 3. The first baffle 21 and the second baffle 22 can divert the liquid entering the outlet pipe 3. At the same time, the first baffle 21 is located below the center of the filter membrane, and the baffle 14 is located above the center of the filter membrane. When liquid enters the inlet pipe 1, the upper and lower parts of the center of the filter membrane are supported by the first baffle 21 and the baffle 14, respectively. This not only reduces the pressure on the center of the filter membrane but also supports the center of the filter membrane, further preventing damage to the filter membrane.

[0051] In some embodiments, the liquid outlet pipe 3 has a first section 7 and a second section 8 connected to each other. Both the first section 7 and the second section 8 are tapered tube structures. The diameters of the first section 7 and the second section 8 decrease from top to bottom. The small diameter end of the first section 7 is larger than the large diameter end of the second section 8. Specifically, when collecting the filtered liquid, the second section 8 extends into the hose. Fasteners can be installed at the first section 7 to secure the hose to the first section 7 and prevent the hose from detaching.

[0052] In summary, in the needle filter provided in this embodiment, the upper housing is first installed on top of the lower housing, with a sealed connection between the upper housing plate 2 and the lower housing plate 24. The flow channel ring 10 contacts and presses the filter membrane against the mounting groove 16. The filter membrane is located between the upper chamber 11 and the lower chamber 17. The baffle 12 of the upper chamber 11 is attached to the top of the filter membrane, and the arc-shaped protrusion 18 of the lower chamber 17 is attached to the bottom of the filter membrane. Since the flow channels 15 of the upper chamber 11 are radially distributed with the inlet pipe 1 as the center, when the liquid enters the upper chamber 11, it flows evenly into the flow channels 15 from the inlet pipe 1 as the center, ensuring that the liquid flow rate into the upper chamber 11 is uniform and stable, and the liquid can... The upper chamber 11 is quickly filled, and the liquid in the upper chamber 11 is filtered through the filter membrane and enters the lower chamber 17. The filtered liquid in the lower chamber 17 flows into the outlet pipe 3 through the annular groove 19 and the radial groove 20. The flow channel 15 distributed in a radial pattern improves the liquid inlet stability of the upper chamber 11, thereby increasing the liquid inlet flow rate and thus improving the overall filtration flow rate and filtration stability of the needle filter. When connected to the syringe, it can prevent the syringe from being unable to push. At the same time, the edge-sealing structure 5 can withstand high pressure, preventing excessive pressure from damaging the filter membrane during use. It can also increase the burst pressure and increase the liquid inlet flow rate when liquid is introduced into the inlet pipe 1.

[0053] The above embodiments are merely illustrative of the principles and effects of this utility model and are not intended to limit the scope of this utility model. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of this utility model. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in this utility model should still be covered by the claims of this utility model.

Claims

1. A needle filter, characterized in that, include: The upper housing includes a liquid inlet pipe and an upper housing plate connected to each other, and the edge of the upper housing plate is provided with a plurality of through holes penetrating the upper housing plate; The lower housing includes a liquid outlet pipe and a lower housing plate connected together; An edge-sealing structure covers the circumference of the upper and lower shells to provide a sealed connection between the upper and lower shells. When the upper shell and the lower shell are assembled, the upper shell plate covers the lower shell plate. The upper shell plate and the lower shell plate are cast circumferentially by a casting process to form the edge-wrapping structure. The edge-wrapping structure enters at least part of the through hole and is locked in the through hole after forming.

2. The needle filter according to claim 1, characterized in that, The upper shell plate has a flow channel ring on the side opposite to the liquid inlet pipe. The flow channel ring surrounds the circumference of the liquid inlet to form an upper chamber communicating with the pipe hole of the liquid inlet pipe. The upper chamber is provided with multiple baffles and cross baffles. The ends of the cross baffles are all connected to the flow channel ring. The center of the cross baffle corresponds to the center of the pipe hole of the liquid inlet pipe. One end of each baffle is connected to the flow channel ring, and the other end extends radially toward the pipe hole of the liquid inlet pipe and is spaced apart from the pipe hole of the liquid inlet pipe. The multiple baffles and cross baffles divide the upper chamber into multiple flow channels. The multiple flow channels are distributed radially with the pipe hole of the liquid inlet pipe as the center.

3. The needle filter according to claim 2, characterized in that, A circular baffle is provided at the center of the cross-shaped baffle, and the baffle is either integrally connected to the cross-shaped baffle or separately connected.

4. The needle filter according to claim 2, characterized in that, The outer diameter of the upper shell plate is larger than the outer diameter of the flow channel ring. The upper shell plate is also provided with multiple buckles on the side away from the liquid inlet pipe. The multiple buckles are evenly distributed along the circumference of the flow channel ring. The top of each buckle is connected to the upper shell plate. Each buckle has a snap-fit ​​protrusion on the side near the flow channel ring. The snap-fit ​​protrusion is located near the bottom of the buckle.

5. The needle filter according to claim 4, characterized in that, The lower shell plate has an installation groove for installing a filter membrane on the side opposite to the liquid outlet pipe. The bottom of the installation groove has a lower chamber that communicates with the pipe hole of the liquid outlet pipe. The lower chamber has multiple arc-shaped protrusions. The multiple arc-shaped protrusions are distributed concentrically with the pipe hole of the liquid outlet pipe as the center, forming multiple annular grooves and radial grooves. The multiple annular grooves are connected to each other through the radial grooves. The multiple radial grooves are connected to the pipe hole of the liquid outlet pipe and are distributed radially with the pipe hole of the liquid outlet pipe as the center.

6. The needle filter according to claim 5, characterized in that, The lower chamber is further provided with a first baffle and a second baffle. The first baffle blocks the outlet pipe at the pipe hole to divert the liquid entering the outlet pipe. There are at least two second baffles, which are arranged circumferentially along the pipe hole of the outlet pipe and are located on both sides of the first baffle.

7. The needle filter according to claim 5, characterized in that, The lower housing is provided with a flange structure along the circumference of the mounting groove. The snap-fit ​​protrusion is connected to the bottom of the buckle through a guide surface. When the upper housing and the lower housing are installed, the guide surface provides guidance for the flange structure. After passing the snap-fit ​​protrusion, the flange structure abuts against the side of the buckle. The snap-fit ​​protrusion blocks the exit direction of the flange structure.

8. The needle filter according to claim 7, characterized in that, The flange structure is also provided with a plurality of limiting bosses, which are evenly distributed on the flange structure along the circumference of the mounting groove.

9. The needle filter according to claim 1, characterized in that, One end of the liquid inlet pipe is connected to the lower shell plate, and the other end is a free end. The free end of the liquid inlet pipe has a snap-fit ​​structure in the circumferential direction.

10. The needle filter according to claim 1, characterized in that, The liquid outlet pipe has a first section and a second section connected to each other. Both the first section and the second section are tapered tube structures. The diameters of the first section and the second section decrease from top to bottom. The smaller diameter end of the first section is larger than the larger diameter end of the second section.

Images