Soft interference fit structure filter

Abstract

The present application relates to the technical field of filter, and discloses a soft interference fit structure filter, a filter module is embedded with a closed end of a shell through filter paper glue, instead of a closed end cover to seal the lower end, the closed end cover and the supporting spring are omitted, the height of the shell is shortened, the oil flow to the area containing the supporting spring is avoided to form turbulence, and the oil resistance is reduced; the open end piece comprises an end piece body and a matching ring which are integrally and coaxially arranged, the end piece body is sealed and bonded to the top end of the filter module; the flange ring is inserted into the matching ring and is radially soft interference fit, the inside and outside of the filter medium are sealed, and the inner sealing ring is omitted; under the premise of ensuring the function of the filter and the interchangeability of each component being unchanged, the number of parts is further reduced, the product weight is reduced, the assembly complexity is reduced, the design cost and the manufacturing cost are maximally reduced, and the design cost and the manufacturing cost are reduced, the reliability is improved, and the environmental protection is enhanced.

Description

Technical Field

[0001] This invention relates to the field of filter technology, and more particularly to a filter with a soft interference fit structure. Background Technology

[0002] In modern engine development, compact structure, low cost, lightweight design, and environmental friendliness are among the main evaluation indicators. Before entering the engine, fuel or engine oil needs to pass through a filtration system to remove contaminants. The main component of the filtration system is the filter, with spin-on filters being the most widely used.

[0003] Traditional fuel filters or oil filters consist of multiple parts, including filter media, open end caps, closed end caps, support springs, inner sealing rings, outer shells, threaded cover plates, and outer sealing rings. Regardless of the type of product, current designs have drawbacks such as a large number of parts, large size, heavy weight, and complex assembly, resulting in high design and manufacturing costs. Summary of the Invention

[0004] The purpose of this invention is to provide a filter with a soft interference fit structure, which eliminates the need for an inner sealing ring, shortens the housing height, and reduces oil resistance; while ensuring the filter function and maintaining the interchangeability of each component, it further reduces the number of parts, reduces product weight, reduces assembly complexity, and reduces design and manufacturing costs.

[0005] To achieve this objective, the present invention adopts the following technical solution: Filters with a soft interference fit include: The outer casing has an open end and a closed end; The filter module is configured as a hollow ring structure, and is coaxially placed inside the outer shell. The bottom end of the filter module is embedded with the closed end through filter paper adhesive. A threaded cover plate, comprising an integral and coaxially arranged cover plate body and a flanged ring, wherein the cover plate body has an oil inlet, the flanged ring is located on the inner ring of the cover plate body and is bent downward in a direction parallel to the axial direction of the cover plate body, the inner ring of the flanged ring is provided with connecting threads, and the hollow part of the flanged ring is configured as an oil outlet, the oil outlet being connected to the hollow part of the filter module; An open end piece, comprising an integral and coaxially arranged end piece body and a mating ring, wherein the end piece body is sealed and bonded to the top of the filter module, the mating ring is located on the inner ring of the end piece body, and the inner ring of the mating ring is softly press-fitted to the outer ring of the flange ring. An external sealing module is connected to the cover plate body, and the outer ring of the external sealing module is connected to the opening end.

[0006] As an optional technical solution for a soft interference fit structure filter, the open end piece is set as a vulcanized rubber sheet, which is bonded to the top of the filter module by heating and foaming, and the mating ring is set as a boss ring.

[0007] As an optional technical solution for a soft interference fit structure filter, the open end piece is made of plastic sheet, which is bonded to the top of the filter module by hot plate welding. The contact area between the inner ring of the mating ring and the outer ring of the flange ring is larger than the inner ring area of ​​the end piece body.

[0008] As an optional technical solution for a filter with a soft interference fit structure, the cover plate body is inclined downward on the side near the flange ring, and the top of the mating ring is flush with the top of the end plate body.

[0009] As an optional technical solution for a soft interference fit structure filter, the outer periphery of the end plate body is provided with multiple positioning protrusions at intervals, and the positioning protrusions all abut against the inner wall of the outer shell.

[0010] As an optional technical solution for a soft interference fit filter, the bottom of the housing is provided with a constriction, the outer diameter of which is smaller than the outer diameter of the open end, and the bottom end of the filter module is inserted into the constriction.

[0011] As an optional technical solution for a soft interference fit filter, the closed end is provided with an inner protrusion.

[0012] As an optional technical solution for a soft interference fit filter, the filter module includes a filter medium and a central tube arranged coaxially. The central tube is disposed inside the filter medium and has multiple circumferential openings.

[0013] As an optional technical solution for a soft interference fit structure filter, the filter medium is set as a paper core, which is made by winding filter paper around the central tube or by connecting V-shaped filter paper end to end.

[0014] As an optional technical solution for a soft interference fit structure filter, the external sealing module includes a sealing ring seat and an outer sealing ring. The sealing ring seat is connected to the cover plate body. The sealing ring seat is provided with an outer ring seat and a sealing groove. The outer ring seat is connected to the open end, and the outer sealing ring is placed in the sealing groove.

[0015] The beneficial effects of this invention are: The soft interference fit filter provided by this invention includes: a housing, a filter module, a threaded cover plate, an open end piece, and an external sealing module. The housing has an open end and a closed end; the filter module is a hollow annular structure and is coaxially placed inside the housing for filtering dirty oil. The bottom end of the filter module is embedded in the closed end with filter paper adhesive, which seals the lower end of the filter module. In this application, the housing is used instead of the closed end cover, and the lower end of the filter module is directly embedded in the housing with filter paper adhesive, which eliminates the need for the closed end cover and the support spring, and the height of the housing can be further shortened; it can also prevent the oil from flowing into the area containing the support spring and forming turbulence, thereby reducing the resistance of the oil.

[0016] The threaded cover plate includes an integral and coaxially arranged cover plate body and a flanged ring. The cover plate body has an oil inlet. The flanged ring is located on the inner ring of the cover plate body and is bent downwards in a direction parallel to the axial direction of the cover plate body. The inner ring of the flanged ring has connecting threads for connecting the filter to the mounting base. The hollow part of the flanged ring is set as an oil outlet, which communicates with the hollow part of the filter module. The open end piece includes an integral and coaxially arranged end piece body and a mating ring. The end piece body is sealed and bonded to the top of the filter module, providing a sealing effect on the top of the filter medium, and the end piece body is located below the cover plate body. The mating ring is located on the inner ring of the end piece body. The flanged ring is inserted into the mating ring, and there is a radial soft interference fit between the end piece and the mating ring, providing a sealing effect on the inner and outer sides of the filter medium. The soft interference fit structure filter design in this application forms a seal directly between the open end piece and the threaded cover plate through a soft interference fit, eliminating the need for an inner sealing ring and further reducing the number of parts.

[0017] This flexible interference fit filter, while ensuring filter functionality and maintaining the interchangeability of all components, optimizes the existing filter structure, reducing the number of parts, shortening the product height, and lowering the product weight. It also reduces assembly complexity, thereby minimizing design and manufacturing costs while improving reliability and enhancing environmental friendliness. Attached Figure Description

[0018] Figure 1 This is a cross-sectional schematic diagram of a soft interference fit structure filter provided in a specific embodiment of the present invention; Figure 2 This is a cross-sectional schematic diagram of the housing of the soft interference fit structure filter provided in a specific embodiment of the present invention; Figure 3 This is a schematic diagram of the oil circuit of a soft interference fit structure filter provided in a specific embodiment of the present invention; Figure 4 This is a schematic diagram of the outer shell in one embodiment of the soft interference fit structure filter provided by a specific embodiment of the present invention; Figure 5 This is a cross-sectional schematic diagram of the housing, filter module, and open end piece in one embodiment of the soft interference fit structure filter provided by a specific embodiment of the present invention; Figure 6 This is a schematic diagram of the outer shell structure in another embodiment of the soft interference fit structure filter provided in a specific embodiment of the present invention; Figure 7 This is a cross-sectional schematic diagram of the housing, filter module, and open end piece in another embodiment of the soft interference fit structure filter provided in a specific embodiment of the present invention; Figure 8 This is a schematic diagram of the filter medium of the soft interference fit structure filter provided in a specific embodiment of the present invention; Figure 9 This is a schematic diagram of the central tube of a soft interference fit filter provided in a specific embodiment of the present invention; Figure 10 This is a schematic diagram of the threaded cover plate of a soft interference fit filter provided in a specific embodiment of the present invention; Figure 11 This is a cross-sectional schematic diagram of the threaded cover plate of the soft interference fit structure filter provided in a specific embodiment of the present invention; Figure 12 This is a cross-sectional schematic diagram of the open end piece of the soft interference fit structure filter provided in a specific embodiment of the present invention; Figure 13 This is a schematic diagram of the structure of the open end piece in one embodiment of the soft interference fit structure filter provided in a specific embodiment of the present invention; Figure 14 This is a schematic diagram of the structure of the open end piece and the outer shell in one embodiment of the soft interference fit structure filter provided by the specific implementation of the present invention; Figure 15 This is a schematic diagram of the threaded cover plate in another embodiment of the soft interference fit structure filter provided by the specific implementation of the present invention; Figure 16 This is a cross-sectional schematic diagram of the open end piece in another embodiment of the soft interference fit structure filter provided in a specific embodiment of the present invention; Figure 17 This is a cross-sectional schematic diagram of the open end piece and the threaded cover plate in another embodiment of the soft interference fit structure filter provided in a specific embodiment of the present invention; Figure 18 This is a schematic diagram of the open end piece in another embodiment of the soft interference fit structure filter provided by the specific embodiments of the present invention; Figure 19This is a cross-sectional schematic diagram of the open end piece and the filter module in another embodiment of the soft interference fit structure filter provided in the specific embodiments of the present invention; Figure 20 This is a schematic diagram of the sealing ring seat of the soft interference fit structure filter provided in a specific embodiment of the present invention; Figure 21 This is a cross-sectional schematic diagram of the sealing ring seat of a soft interference fit structure filter provided in a specific embodiment of the present invention.

[0019] In the picture: 100. Outer shell; 101. Open end; 102. Closed end; 110. Narrowing; 120. Inner protrusion; 210. Filter media; 220. Central tube; 300. Threaded cover plate; 301. Oil inlet; 302. Oil outlet; 303. Connecting thread; 310. Flanged ring; 400. Open end piece; 401. Positioning protrusion; 410. Mating ring; 510. Sealing ring seat; 511. Outer ring seat; 512. Sealing groove; 520. Outer sealing ring; 900, filter paper adhesive. Detailed Implementation

[0020] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, the accompanying drawings show only the parts relevant to the present invention, and not all of the structures.

[0021] In the description of this invention, unless otherwise explicitly specified and limited, the terms "connected," "linked," and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0022] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0023] In the description of this embodiment, the terms "upper," "lower," "right," and "left," etc., refer to the orientation or positional relationship shown in the accompanying drawings. They are used only for ease of description and simplification of operation, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the present invention. In addition, the terms "first" and "second" are used only for distinction in description and have no special meaning.

[0024] like Figures 1 to 21 As shown, this invention discloses a soft interference fit filter, including a housing 100, a filter module, a threaded cover plate 300, an open end piece 400, and an external sealing module. The housing 100 is a cylindrical stamped part with an open end 101 and a closed end 102. The filter module is a hollow annular structure, coaxially placed inside the housing 100, used for filtering dirty oil. The bottom end of the filter module is fitted to the closed end 102 with filter paper adhesive 900, providing a seal to the lower end of the filter module.

[0025] In traditional structures, the lower end of the filter module is typically glued to a closed end cap. The flexible interference fit filter design in this application uses a portion of the outer shell 100 to replace the function of the closed end cap. The lower end of the filter module is directly glued to the outer shell 100 using filter paper adhesive 900, eliminating the need for a closed end cap. Similarly, in traditional structures, a support spring is provided between the closed end cap and the outer shell 100 to provide axial support for the filter module. In the flexible interference fit filter design of this application, after replacing the closed end cap with the outer shell 100, the filter module is axially fixed to the outer shell 100, eliminating the need for a support spring. Compared to the traditional structure where the outer shell 100 needs space to accommodate the support spring, this design, by eliminating the support spring and other components, allows for a further reduction in the height of the outer shell 100.

[0026] Understandably, in traditional structures, after the oil enters the filter, it flows towards the area housing the support spring, easily creating turbulence and increasing oil resistance. The soft interference fit filter design in this application eliminates the space for the support spring, reducing turbulence and thus lowering oil resistance. Overall, while maintaining the interchangeability of all components, optimizing the existing filter structure not only reduces the number of parts, shortens the product height, and lowers the product weight, but also reduces assembly complexity. This results in reduced design and manufacturing costs, while simultaneously improving reliability and enhancing environmental friendliness.

[0027] In this embodiment, reference Figure 1 , Figure 8 and Figure 9 The filter module includes a filter medium 210 and a central tube 220 arranged coaxially. The central tube 220 is located inside the filter medium 210 and provides support for the filter medium 210. The central tube 220 is a cylindrical part with multiple circumferential openings.

[0028] Specifically, the filter medium 210 is set as a paper core, which is generally made of filter paper wound around the central tube 220. Dirty oil can be filtered through layers of filter paper, and the balance between the oil filtration rate and the filter paper thickness needs to be considered; or the paper core is made of... Figure 8 The filter paper with a V-shaped pleat structure is made by joining the ends together. Its shape is similar to an accordion and it surrounds the outer perimeter of the central tube 220. The repeated pleats expand the filter contact surface, which helps to optimize the filtration rate.

[0029] In this embodiment, in order to achieve a sealed structure, the lower end of the filter medium 210 is first bonded to the filter paper adhesive 900. The filter paper adhesive 900 that can be demolded from the mold is selected. The bottom end of the filter medium 210 is cured and molded by the mold and then demolded. The cured filter paper adhesive 900 is inserted into the closed end 102. The curing distribution area of ​​the filter paper adhesive 900 is further reasonably controlled to avoid problems such as excessive glue overflow affecting the filtration rate or insufficient glue causing sealing failure, thus ensuring stable filtration function.

[0030] For example, the bottom end of the filter medium 210 can also be directly bonded to the closed end 102 by filter paper adhesive 900. By directly injecting the filter paper adhesive 900 between the bottom end of the filter medium 210 and the closed end 102 for bonding, the structure is stable and the sealing effect is excellent, and the assembly operation is simpler and more efficient.

[0031] In this embodiment, reference Figures 10 to 12The threaded cover plate 300 is a disc-shaped stamped part, including an integral and coaxially arranged cover plate body and a flange ring 310. The cover plate body has an oil inlet 301. The flange ring 310 is located in the inner ring of the cover plate body and is bent downward in a direction parallel to the axial direction of the cover plate body. The inner ring of the flange ring 310 is provided with a connecting thread 303, which is used to connect the filter to the mounting base. The hollow part of the flange ring 310 is set as an oil outlet 302, which is connected to the hollow part of the filter module.

[0032] A novel open end piece 400 is designed, comprising an integral and coaxially arranged end piece body and a mating ring 410. The end piece body is sealed and bonded to the top of the filter module and is located below the cover plate body. The mating ring 410 is located on the inner ring of the end piece body, and the inner ring of the mating ring 410 can be flexibly interference-fitted with the outer ring of the flange ring 310.

[0033] For example, its initial state is a thin, round vulcanized sheet, which is bonded to the top of the filter module using a heat-foaming process to seal the top of the filter medium 210. During the heat-foaming process, a mating ring 410 with a boss is formed on its inner side using a mold. Figure 12 As shown in the figure. Compared to the traditional structure where the open end cap and the upper end of the filter medium 210 need to be bonded together with filter paper adhesive 900, the soft interference fit structure filter design in this application directly bonds the vulcanized rubber sheet to the upper end of the filter medium 210, which can eliminate the need for filter paper adhesive 900.

[0034] The flanged ring 310 is inserted into the mating ring 410, and a radial soft interference fit is formed between them, which seals the inner and outer sides of the filter medium 210. The soft interference fit filter design in this application forms a seal between the open end plate 400 and the threaded cover plate 300 through a direct soft interference fit, eliminating the need for an inner sealing ring between the open end cover 400 and the threaded cover plate 300 in traditional structures. This eliminates the need for an inner sealing ring and further reduces the number of components.

[0035] like Figure 1 , Figure 20 and Figure 21 As shown, the outer sealing module includes a sealing ring seat 510 and an outer sealing ring 520. The sealing ring seat 510 is located above the threaded cover plate 300 and is a disc-shaped stamped part. The sealing ring seat 510 is connected to the cover plate body by welding or riveting. The sealing ring seat 510 is provided with an outer ring seat 511 and a sealing groove 512. The outer ring seat 511 is connected to the open end 101 and they interlock to ensure stable assembly. The outer sealing ring 520 is placed in the sealing groove 512 and is a ring-shaped rubber part. The outer sealing ring 520 seals against the mounting base to seal the soft interference fit structure filter and the mounting base.

[0036] Specifically, such as Figure 3 As shown, dirty oil (fuel or engine oil) enters the interior of the soft interference fit filter through the oil inlet 301, flows outwards through the gap between the open end plate 400 and the threaded cover plate 300, continues to flow downwards through the gap between the open end plate 400 and the housing 100, then passes through the filter medium 210. After being filtered by the filter medium 210, the dirty oil becomes clean oil, then passes through the central tube 220, and finally flows out of the oil outlet 302 for use by downstream devices (combustion or lubrication).

[0037] This soft interference fit filter further optimizes the product structure while ensuring filter functionality. It reduces the number of parts while maintaining product interchangeability, thus allowing for further reduction in product height and weight, and simplifies assembly. This minimizes design and manufacturing costs.

[0038] For example, when there is no means to control the coaxiality between the open end piece 400 and the outer shell 100 during the assembly process, positioning protrusions 401 are evenly distributed on the outer periphery of the thin circular piece in the initial state. After heating and foaming, the positioning protrusions 401 are also foamed and formed. The multiple positioning protrusions 401 evenly distributed on the outer periphery of the end piece body abut against the inner wall of the outer shell 100, such as... Figure 13 and Figure 14 As shown, this can improve the coaxiality between the open end piece 400 and the housing 100, making it easier for the threaded cover plate 300 to be inserted into the open end piece 400 and the housing 100.

[0039] In another embodiment, reference Figures 15 to 17 When the cover plate body of the threaded cover plate 300 tilts downward on the side near the flange ring 310, and the flange ring 310 shifts further downward, the boss structure on the top of the mating ring 410 is removed, so that the mating ring 410 is flush with the top of the end plate body. After the mating ring 410 and the threaded cover plate 300 are mated together, there is still enough gap between them for dirty oil to flow.

[0040] In yet another embodiment, reference is made to... Figures 18 to 19 When a factory lacks the ability to heat and foam but has the ability to hot plate weld, a plastic sheet can be used instead of a vulcanized rubber sheet as the open end piece 400. The hot plate welding process is used to heat and melt the surface of the plastic sheet, and then bond the plastic sheet to the top of the filter module. At the same time, the contact area between the inner ring of the mating ring 410 and the outer ring of the flange ring 310 is set to be larger than the inner ring area of ​​the end piece body to ensure the sealing of the inner and outer sides of the filter medium 210.

[0041] like Figure 4 and Figure 5As shown, when there is no means to control the coaxiality of the filter module and the housing 100 after bonding during the assembly process, a constriction 110 is provided at the bottom of the housing 100. The outer diameter of the constriction 110 is smaller than the outer diameter of the open end 101. The bottom end of the filter module is inserted into the constriction 110 of the housing 100, which reduces the gap between the outer periphery of the filter module and the inner wall of the housing 100, thereby improving the coaxiality between the filter module and the housing 100 and further facilitating the insertion of the threaded cover plate 300 into the open end piece 400 and the housing 100.

[0042] like Figure 6 and Figure 7 As shown, when the internal working pressure of the soft interference fit structure filter is not very high, an inner protrusion 120 is provided at the closed end 102 at the bottom of the housing 100 to offset part of the filling area of ​​the filter paper adhesive 900. Under the premise that the relatively small internal pressure of the soft interference fit structure filter will not deform the housing 100 and the inner protrusion 120, the amount of filter paper adhesive 900 can be effectively reduced.

[0043] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. Those skilled in the art will be able to make various obvious changes, readjustments, and substitutions without departing from the scope of protection of the present invention. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A filter with a soft interference fit structure, characterized in that, include: The outer casing (100) is provided with an open end (101) and a closed end (102). The filter module is configured as a hollow ring structure, and the filter module is coaxially placed inside the outer shell (100). The bottom end of the filter module is embedded with the closed end (102) through filter paper glue. A threaded cover plate (300) includes an integral and coaxially arranged cover plate body and a flanged ring (310). The cover plate body has an oil inlet (301). The flanged ring (310) is located in the inner ring of the cover plate body and is bent downward in a direction parallel to the axial direction of the cover plate body. The inner ring of the flanged ring (310) is provided with a connecting thread (303). The hollow part of the flanged ring (310) is configured as an oil outlet (302). The oil outlet (302) is connected to the hollow part of the filter module. An open end piece (400) includes an integral and coaxially arranged end piece body and a mating ring (410). The end piece body is sealed and bonded to the top of the filter module. The mating ring (410) is located in the inner ring of the end piece body, and the inner ring of the mating ring (410) is softly press-fitted to the outer ring of the flange ring (310). An external sealing module is connected to the cover plate body, and the outer ring of the external sealing module is connected to the opening end (101).

2. The soft interference fit filter according to claim 1, characterized in that, The open end piece (400) is a vulcanized rubber sheet, which is bonded to the top of the filter module by heating and foaming. The mating ring (410) is a boss ring.

3. The soft interference fit filter according to claim 1, characterized in that, The open end piece (400) is made of plastic sheet, which is bonded to the top of the filter module by hot plate welding. The contact area between the inner ring of the mating ring (410) and the outer ring of the flange ring (310) is greater than the inner ring area of ​​the end piece body.

4. The soft interference fit filter according to claim 1, characterized in that, The cover plate body is inclined downward on the side near the flange ring (310), and the top of the mating ring (410) is flush with the top of the end piece body.

5. The soft interference fit filter according to claim 1, characterized in that, The outer periphery of the end piece body is provided with a plurality of positioning protrusions (401) spaced apart, and the positioning protrusions (401) all abut against the inner wall of the outer shell (100).

6. The soft interference fit filter according to claim 1, characterized in that, The bottom of the outer shell (100) is provided with a constriction (110), the outer diameter of the constriction (110) is smaller than the outer diameter of the open end (101), and the bottom end of the filter module is inserted into the constriction (110).

7. The soft interference fit filter according to claim 1, characterized in that, The closed end (102) is provided with an inner protrusion (120).

8. The soft interference fit filter according to claim 1, characterized in that, The filter module includes a filter medium (210) and a central tube (220) arranged coaxially. The central tube (220) is disposed inside the filter medium (210) and has a plurality of circumferential openings.

9. The soft interference fit filter according to claim 8, characterized in that, The filter medium (210) is configured as a paper core, which is made by wrapping filter paper around the central tube (220) or by connecting V-shaped filter paper end to end.

10. The soft interference fit filter according to any one of claims 1-9, characterized in that, The outer sealing module includes a sealing ring seat (510) and an outer sealing ring (520). The sealing ring seat (510) is connected to the cover plate body. The sealing ring seat (510) is provided with an outer ring seat (511) and a sealing groove (512). The outer ring seat (511) is connected to the opening end (101). The outer sealing ring (520) is placed in the sealing groove (512).

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