Filter element limiting ring and filter device

Abstract

The utility model provides a filter element spacing ring (200) and filter device (100), the filter device is provided with a filter casing (11) and a filter element (12) arranged in the filter casing, the filter element spacing ring (200) comprises: an annular main body part (21) which is annular and has axial, radial and circumferential directions, the outer diameter of which is matched with the inner diameter of the filter casing; at least three rod pins (22) that protrude radially inward from the inner surface of the annular body section and that each have a root section (221) connected to the annular body section, an inner end surface (222) positioned radially inward, and side wall sections (223) positioned on both sides in the circumferential direction; the amount by which the rod pin protrudes inward in the radial direction is set so that the position of the filter element relative to the center of the filter casing can be limited by the inner end face. According to the filter element limiting ring and the filter device, the filter element can be easily fixed at the central position of the filter casing, so that the sealing performance between the filter element and the filter casing is improved.

Description

Technical Field

[0001] The utility model relates to a filter element limiting ring and a filtering device, and more particularly to a filter element limiting ring and a filtering device used in a filtering device for filtering ink such as solder resist ink for PCB boards. Background Art

[0002] During the manufacturing process, solder mask ink used in PCBs requires filtration. This filtration device typically consists of a filter housing and a filter element. During use, the center of the filter element and housing must be precisely aligned to ensure a tight seal.

[0003] Prior art discloses the following technical solutions for aligning the centers of a filter element and a filter housing. For example, CN108744752A provides a filter element connector comprising a coaxial filter element bayonet end cap and a filter housing bayonet connector, both having a central hole, to ensure connection stability and sealing.

[0004] However, in the technical solutions disclosed in the prior art, multiple attempts are required to fix the filter element at the center of the filter cover, and the problem still exists that the filter element cannot be easily fixed at the center of the filter cover. Utility Model Content

[0005] Therefore, the purpose of the present invention is to provide a filter element retaining ring and a filter device that can easily fix the filter element at the center position of the filter cover, thereby improving the sealing between the filter element and the filter cover.

[0006] In order to achieve the above-mentioned purpose, the present application provides a filter element limiting ring, which is used for a filtering device, which has a filter cover and a filter element placed in the filter cover, and is characterized in that the filter element limiting ring comprises: an annular main body, which is annular, has axial, radial and circumferential directions, and the outer diameter matches the inner diameter of the filter cover; at least three rod pins, which protrude from the inner surface of the annular main body toward the radial inner side, have a root connected to the annular main body, an inner end face located on the radial inner side and side wall parts located on both sides of the circumference; the protrusion amount of the rod pin toward the radial inner side is set so that the filter element can be limited by the inner end face to the position of the center of the filter cover.

[0007] In at least one embodiment, the upper surface of the rod pin has a chamfered portion, and the chamfered portion is formed by decreasing the height of the upper surface of the rod pin from the radially outer side toward the radially inner side.

[0008] In at least one embodiment, the chamfered portion is inclined downwardly with respect to the upper surface of the annular main body at an angle of 45 to 75 degrees.

[0009] In at least one embodiment, the circumferential length of the root portion is greater than the circumferential length of the inner end surface, and the inner end surface is connected to the side wall portion in an arc shape.

[0010] In at least one embodiment, the number of the rod pins is four, and the rod pins are arranged at equal intervals on the annular main body.

[0011] In at least one embodiment, the annular body portion and the rod pin are integrally formed.

[0012] In at least one embodiment, the filter element limiting ring is made of polyoxymethylene.

[0013] In at least one embodiment, a height of the root portion in the axial direction is the same as a height of the annular main body portion, and the chamfered portion extends from the root portion to the inner end surface.

[0014] In at least one embodiment, the length of the root portion in the circumferential direction is less than or equal to 1 / 16 of the annular main body portion.

[0015] The present application also provides a filtering device, characterized in that it includes: a filter cover, a filter element placed in the filter cover, and the aforementioned filter element limiting ring, the filter cover has a column at the radial center, the filter element has an axial through hole at the radial center, and in the assembled state, flow paths are respectively formed between the outer surface of the filter element and the inner surface of the filter cover, and between the inner surface of the filter element and the outer surface of the column.

[0016] According to the utility model, a filter element limiting ring and a filter device can be provided which can easily fix the filter element at the center position of the filter cover, thereby improving the sealing performance between the filter element and the filter cover. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a conceptual diagram of a filtering device according to one embodiment of the present invention.

[0018] Figure 2 It is a three-dimensional diagram of a filter element limiting ring according to one embodiment of the present invention.

[0019] Figure 3 It is a top view of a filter element limiting ring according to one embodiment of the present invention.

[0020] Description of Reference Numerals

[0021] 100. Filter device; 11. Filter cover; 12. Filter element; 111. Filter cartridge; 112. Ink inlet; 113. Ink outlet; 114. Gasket; 115. Column; 200. Filter element limiting ring; 21. Annular main body; 22. Rod pin; 221. Root; 222. Inner end face; 223. Side wall; 224. Chamfered portion; 1A. Space for ink to be filtered; 1B. Space for ink after filtration. DETAILED DESCRIPTION

[0022] Hereinafter, a filter element limiting ring and a filter device according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

[0023] It should be noted that the dimensions of the components in the drawings may be inconsistent with the actual dimensions, and should be considered in light of the actual situation. In addition, the following embodiment is merely an example for illustrating the present invention, and the present invention is not limited thereto. Modifications and changes made within the scope of protection of the present invention are also included in the present invention.

[0024] (1. Filter device 100)

[0025] Figure 1 FIG1 is a schematic diagram of an example of a filtering device according to an embodiment of the present invention. The filtering device 100 is a filtering device for solder resist ink used in PCB boards, but is not limited thereto and can also be used to filter other objects.

[0026] like Figure 1 As shown, the filter device 100 includes a filter cover 11 and a filter element 12 placed in the filter cover 11 when in use.

[0027] The filter cover 11 includes a filter cartridge 111 , an ink inlet 112 , an ink outlet 113 , a gasket 114 , a column 115 , an end cap (not shown), and a nut for fixing the end cap.

[0028] The filter cartridge 111 is cylindrical and open in the vertical direction, and is used to house the filter element 12. The ink inlet 112 and ink outlet 113 are cylindrical and located at the bottom of the filter cartridge 111. They are integrally formed with the filter cartridge 111 and open in a left-right direction perpendicular to the opening of the filter cartridge 111. The ink inlet 112 communicates with the interior of the filter cartridge 111 at a radially outer portion of the interior space of the filter cartridge 111. The ink outlet 113 communicates with the interior of the filter cartridge 111 at a central portion of the interior space of the filter cartridge 111. The gasket 114 is annular. The outer diameter of the gasket 114 is larger than the outer diameter of the end of the ink outlet 113 that communicates with the filter cartridge 111 and smaller than the inner diameter of the filter cartridge 111. The inner diameter of the gasket 114 is smaller than or equal to the inner diameter of the end of the ink outlet 113 that communicates with the filter cartridge 111 and larger than the outer diameter of the column 115 described later. The column 115 is in the shape of an elongated column and extends from the bottom of the filter cartridge 111 to the upper surface of the filter cartridge 111 at the radial center of the filter cartridge 111. In addition, the end cap (not shown) has a through hole matching the column 115 at the radial center.

[0029] The filter element 12 is cylindrical, with an outer diameter equal to or smaller than the outer diameter of the gasket 114, and an inner diameter greater than or equal to the inner diameter of the gasket 114. The height of the filter element 12 is less than or equal to the height of the filter cartridge 111, so that when the filter element 12 is placed in the filter cover 11, the upper end surface of the filter element 12 does not exceed the upper end surface of the filter cover 11.

[0030] like Figure 1 As shown, in the assembled state, within the filter device 100, there is formed a space enclosed by the inner surface of the filter cartridge 111, the outer surface of the filter element 12, and the lower surface of the end cap, namely, the ink space to be filtered 1A; and a space enclosed by the inner surface of the filter element 12, the outer surface of the pillar 115, and the lower surface of the end cap, namely, the filtered ink space 1B. The filter device 100 is connected to the outside only at the inlet of the ink inlet 112 and the outlet of the ink outlet 113. The ink to be filtered enters the ink space to be filtered 1A through the ink inlet 112, is filtered by the filter element 12, enters the filtered ink space 1B, and is finally discharged through the ink outlet 113.

[0031] (2. Filter element limiting ring 200)

[0032] Figure 2 It is a three-dimensional view of a filter element limiting ring 200 according to one embodiment of the present invention. Figure 3 It is a top view of a filter element limiting ring 200 according to one embodiment of the present invention.

[0033] like Figure 2 and Figure 3As shown, the filter element retaining ring 200 comprises an annular main body 21, which is annular and has axial, radial, and circumferential dimensions, with an outer diameter matching the inner diameter of the filter housing 11. Four pins 22 protrude radially inward from the inner surface of the main body 21 at equal intervals around the circumference of the main body 21. These pins 22 have a root portion 221 connected to the main body 21, an inner end surface 222 located radially inward, and sidewalls 223 located on either side of the circumference. The inner end surface 222 and the sidewalls 223 are connected in an arcuate manner. The radial inward projection of the pins 22 is set so that the position of the filter element 12 relative to the center of the filter housing 11 can be restrained by the inner end surface 222. Here, "the position of the filter element relative to the center of the filter housing can be restrained by the inner end surface" means that the inner end surface is sufficient to limit radial displacement of the filter element, which includes both completely preventing radial movement of the filter element and allowing minimal radial movement. It is easy to understand that what is important is that the inner end surface is sufficient to limit the radial displacement of the filter element to the extent that no gap is generated between the contact surface between the filter element and the filter cover, and the contact surface between the filter element and the end cover, into which ink can flow.

[0034] The upper surface of the rod pin 22 has a chamfered portion 224 formed by decreasing the height of the upper surface of the rod pin 22 from the radially outer side to the radially inner side. The chamfered portion 224 is preferably inclined downward at an angle of 45 to 75 degrees relative to the upper surface of the annular body portion 21.

[0035] The circumferential length of the root portion 221 is greater than the circumferential length of the inner end surface 223, and the axial height of the root portion 221 is the same as the height of the annular main body 21. The circumferential length of the root portion 221 is less than 1 / 16 of the annular main body 21. If the circumferential length of the root portion 221 is too large, it will prevent the ink to be filtered from entering the ink space 1A through the gaps between the rod pins 22.

[0036] In this embodiment, the filter element retaining ring 200 is made of polyoxymethylene, and the annular main body 21 and the rod pin 22 are integrally formed. However, this is not limiting. The filter element retaining ring 200 can be made of other existing materials, such as polyolefin, polyvinyl chloride, polystyrene, phenolic plastic, and amino plastic. Elastic materials can also be used without affecting the retaining and sealing functions.

[0037] exist Figure 3In a specific embodiment shown, the outer diameter of the annular main body 21 of the filter element limiting ring 200 is 84 mm, the inner diameter is 80 mm, the height is 25 mm, and the distance between the opposing rod pins 22 is 68 mm. In contrast, the inner diameter of the filter cover 11 is 85 mm. The axial height of the inner end face of the rod pin 22 is 8 mm. In addition, the chamfered portion 224 is tilted downward at an angle of 60 degrees relative to the upper surface of the annular main body 21. The thickness of the annular main body 21 should not be too thick to avoid affecting the ink to be filtered from passing through the space enclosed by the annular main body 21 and the side wall portion 223 of the rod pin 22 and entering the ink space 1A to be filtered. In this embodiment, the thickness of the annular main body 21 is 2 mm. It can be understood that those skilled in the art can adjust the size of the filter element limiting ring to match the size of the filter.

[0038] (3. Assembly Method of Filter Device 100)

[0039] When assembling the filter device 100, the filter element retaining ring 200 is placed into the filter housing 11. The outer diameter of the filter element retaining ring 200 matches the inner diameter of the filter housing 11, and there is no gap or a very small gap between the outer surface of the filter element retaining ring 200 and the inner surface of the filter housing 11, so that the filter element retaining ring 200 can be smoothly placed into the filter housing 11. The lower surface of the filter element retaining ring 200 abuts the bottom of the filter cartridge 111. As a result, the filter element retaining ring 200 and the filter housing 11 are in a center-aligned state, and thus naturally aligned with the gasket 114.

[0040] Next, the filter element 12 is placed into the filter housing 11, with the column 115 extending through the through-hole of the filter element 12. The lower end of the filter element 12 first abuts the chamfered portion 224 of the pin 22. Guided by the inclined structure of the chamfered portion 224, it slides smoothly onto the gasket 114, thereby abutting the lower end face of the filter element 12 against the gasket 114. The outer circumference of the filter element 12 is restrained by the inner end face 222 of the pin 22 of the filter element retaining ring 200, and is aligned with the center of the filter cartridge 111 and the gasket 114. Next, the upper end face of the filter housing 11 is sealed using the end cap (not shown) of the filter housing 11, with the column 115 extending through the through-hole of the end cap. Then, use the end cover fixing nut to tighten from the upper end side of the column 115, and use the end cover and gasket 114 to apply pressure to the filter element 12 from the top and bottom directions to fix the position of the filter element 12 relative to the center and ensure that the filter element 12 and the end cover, as well as the filter element 12 and the gasket 114 are in a sealed state.

[0041] In the working state, the ink to be filtered enters the ink space 1A to be filtered from the inlet of the ink inlet portion 112 under high pressure through the inlet formed by the annular main body portion 21, the rod pin 22 and the outer circumference of the filter element 12, is filtered by the filter element 12, and then enters the filtered ink space 1B, and is finally discharged through the ink outflow portion 113.

[0042] (4. Modification)

[0043] The specific structure of the filter element limit ring is only an example, and the present invention can be modified within the scope of the disclosed technical concept. The following modifications are only examples and are not limited to these.

[0044] The number of pins 22 is not limited to four; considering the need to utilize the inner end surface 222 to restrict the position relative to the center of the filter cover 11, three or more pins 22 are sufficient. Furthermore, too many pins 22 prevent the ink to be filtered from entering the ink space 1A through the gaps between the pins 22. Therefore, too many pins 22 are not recommended.

[0045] In addition, the inner end surface 222 and the side wall portion 223 do not need to be connected in an arc shape, as long as it does not affect the insertion of the filter element 12.

[0046] In the aforementioned embodiment, the chamfered portion 224 extends from the root portion 221 to the inner end surface 222 , but the chamfered portion 224 may be formed on a portion of the upper surface of the rod pin 22 .

[0047] In the aforementioned embodiment, the height of the root portion 221 in the axial direction is the same as the height of the annular main body portion 21 , but the height of the root portion 221 in the axial direction may be smaller than the height of the annular main body portion 21 .

[0048] The annular main body 21 and the rod pin 22 do not need to be formed integrally, but may be formed separately, or may be made of different materials and assembled using existing assembly methods.

[0049] The gasket 114 is not necessarily required, and may be a structure formed integrally with the filter cover to form a flow path.

[0050] (5. Effects)

[0051] In the prior art, when assembling the filter device 100, the filter element 12 is placed into the filter housing 11 in such a manner that the column 115 passes through the through hole of the filter element 12, and the lower end surface of the filter element 12 abuts against the gasket 114. Next, the upper end surface of the filter housing 11 is sealed using an end cap (not shown) of the filter housing 11, such that the column 115 passes through the through hole of the end cap. Then, the end cap fixing nut is tightened from the upper end side of the column 115, and the end cap and gasket 114 are used to apply pressure to the filter element 12 from the top and bottom to fix the position of the filter element 12 relative to the center.

[0052] However, in the prior art, multiple adjustments are required during assembly to align the center positions of the filter element 12, the column 115, and the gasket 114. This is time-consuming and labor-intensive. Furthermore, if the center positions of the filter element 12, the column 115, and the gasket 114 are not aligned, the following problems may arise: The gasket 114 is misaligned with the filter element 12, resulting in a gap between the outer edge of the gasket 114 and the outer edge of the filter element 12. The ink to be filtered flowing in from the ink inlet 112 not only enters the ink space 1A to be filtered, but also enters the filtered ink space 1B, resulting in unfiltered impurities in the filtered ink. On the other hand, if, for example, the end cap has a protrusion for contacting the filter element 12, a gap may also form between the protrusion and the filter element 12 on the end cap. This can cause the ink to be filtered flowing in from the ink inlet 112 to not only enter the ink space 1A to be filtered, but also enter the filtered ink space 1B through the gap between the end cap and the filter element 12.

[0053] In addition, in the prior art, even if no misalignment occurs when the filter element 12 is installed, the contact surface between the filter element 12 and the filter cover 11 may be misaligned under high pressure and large flow conditions during ink filtering, causing unfiltered ink to leak from the gap between the contact surfaces into the filtered ink space 1B.

[0054] The utility model provides a filter element limiting ring, which is used for a filtering device, which has a filter cover and a filter element placed in the filter cover, and the filter element limiting ring comprises: an annular main body, which is annular, has axial, radial and circumferential directions, and an outer diameter that matches the inner diameter of the filter cover; at least three rod pins, which protrude radially inward from the inner surface of the annular main body, have a root connected to the annular main body, an inner end face located radially inward, and side wall parts located on both sides of the circumference; the protrusion amount of the rod pins to the radial inside is set so that the filter element can be limited by the inner end face in position relative to the center of the filter cover.

[0055] This technical solution solves the aforementioned problems in the prior art. The pins of the filter element retaining ring fit snugly against the outer surface of the filter element, accurately positioning the filter element at its contact surface with the filter housing (gasket), and is extremely simple to operate. Furthermore, the use of the pins built into the filter element retaining ring to position the filter element reduces or eliminates the radial movement of the filter element within the filter housing, eliminating the problem of misalignment between the contact surface of the filter element and the filter housing, which could lead to unfiltered ink leaking into the filtered ink space.

[0056] Preferably, the upper surface of the pin has a chamfered portion, the chamfered portion being formed by decreasing the height of the upper surface of the pin from the radially outer side toward the radially inner side. Further preferably, the chamfered portion is inclined downwardly at an angle of 45 to 75 degrees relative to the upper surface of the annular body.

[0057] By designing a chamfered portion on the upper surface of the rod pin, the contact surface between the filter element and the filter cover can be smoothly guided to be accurately positioned.

[0058] Preferably, the circumferential length of the root of the rod pin is greater than the circumferential length of the inner end surface of the rod pin, and the inner end surface is connected to the side wall portion in an arc shape.

[0059] This secures the pin to the annular body, reduces the area of ​​contact between the pin's inner end and the filter element, and increases the area of ​​the inlet formed by the space surrounding the annular body, the pin, and the outer periphery of the filter element. The curved connection prevents corners in the pin from scraping the filter element.

[0060] Preferably, there are four rod pins, and the rod pins are arranged at equal intervals on the annular main body.

[0061] In this manner, the area of ​​the inlet formed by the space defined by the annular main body, the rod pin, and the outer circumference of the filter element can be ensured while ensuring stable positioning of the filter element relative to the center of the filter housing.

[0062] Preferably, the annular main body and the rod pin are integrally formed.

[0063] In this way, the filter element limiting ring can be formed in a simple manner.

[0064] Preferably, the filter element limiting ring is made of polyformaldehyde.

[0065] Polyformaldehyde material has the characteristics of high strength, wear resistance, solvent resistance, and no metal foreign matter. By using polyformaldehyde material, the filter element limit ring can avoid the generation of impurities in the ink.

[0066] Preferably, the height of the root portion of the rod pin in the axial direction is the same as the height of the annular main body portion, and the chamfered portion extends from the root portion to the inner end surface.

[0067] In this way, the rod pin can be firmly fixed to the annular main body, thereby increasing the durability of the filter element limiting ring.

[0068] Preferably, the length of the root portion of the rod pin in the circumferential direction is 1 / 16 or less of the length of the annular main body portion.

[0069] This allows the pin to be securely fixed to the annular body, reduces the area of ​​contact between the inner end face of the pin and the filter element, and increases the area of ​​the inlet formed by the space formed by the annular body, the pin, and the outer periphery of the filter element.

[0070] The utility model also provides a filtering device, which is characterized in that it includes: a filter cover, a filter element placed in the filter cover, and the aforementioned filter element limiting ring, the filter cover has a column at the radial center, the filter element has an axial through hole at the radial center, and in the assembled state, flow paths are respectively formed between the outer surface of the filter element and the inner surface of the filter cover, and between the inner surface of the filter element and the outer surface of the column.

[0071] The filtering device can easily align the center positions of the filter element, the column and the gasket, and avoid the problem of unfiltered ink leaking into the filtered ink space due to misalignment of the contact surface between the filter element and the filter cover.

[0072] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in the present invention should be included in the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be based on the scope of protection of the claims.

[0073] Industrial applicability

[0074] According to the utility model, a filter element limiting ring and a filter device can be provided which can easily fix the filter element at the center position of the filter cover, thereby improving the sealing performance between the filter element and the filter cover.

Claims

1. A filter element limiting ring, which is used for a filter device, the filter device having a filter cover and a filter element placed in the filter cover, characterized in that: The filter element limiting ring includes: an annular main body, which is annular and has axial, radial and circumferential directions, and an outer diameter that matches the inner diameter of the filter cover; at least three rod pins, projecting radially inward from the inner surface of the annular main body, and having a root portion connected to the annular main body, an inner end surface located radially inward, and sidewall portions located on both sides in the circumferential direction; The amount of projection of the rod pin toward the radially inner side is set so that the position of the filter element relative to the center of the filter housing can be restricted by the inner end surface.

2. The filter element limiting ring according to claim 1, characterized in that: The upper surface of the rod pin has a chamfered portion, and the chamfered portion is formed by decreasing the height of the upper surface of the rod pin from the radially outer side toward the radially inner side.

3. The filter element limiting ring according to claim 2, characterized in that: The chamfered portion is inclined downwardly with respect to the upper surface of the annular main body at an angle of 45 to 75 degrees.

4. The filter element limiting ring according to claim 1, characterized in that: The circumferential length of the root portion is greater than the circumferential length of the inner end surface, and the inner end surface is connected to the side wall portion in an arc shape.

5. The filter element limiting ring according to claim 1, characterized in that: There are four rod pins, and the rod pins are arranged at equal intervals on the annular main body.

6. The filter element limiting ring according to claim 1, characterized in that: The annular main body and the rod pin are integrally formed.

7. The filter element limiting ring according to claim 1, characterized in that: The filter element limiting ring is made of polyformaldehyde.

8. The filter element limiting ring according to claim 2, characterized in that: The height of the root portion in the axial direction is the same as that of the annular main body portion, and the chamfered portion extends from the root portion to the inner end surface.

9. The filter element limiting ring according to claim 1, characterized in that: The length of the root portion in the circumferential direction is 1 / 16 or less of the annular main body portion.

10. A filtering device, characterized in that: include: A filter cover, a filter element placed in the filter cover, and a filter element limiting ring according to any one of claims 1 to 9, The filter cover has a column at the radial center, and the filter element has an axial through hole at the radial center. In the assembled state, flow paths are formed between the outer surface of the filter element and the inner surface of the filter cover, and between the inner surface of the filter element and the outer surface of the column.

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