Abstract
A filter bellows with zigzag-folded filter medium has first and second fold edges extending between opposite end edge faces of the filter medium. The filter bellows has opposite end faces with an end fold. The filter bellows in use has a raw fluid-side surface and a clean fluid-side surface. First fold edges are positioned at the raw fluid-side surface and second fold edges are positioned at the clean fluid-side surface. The filter bellows has a passage extending between raw fluid-side surface and clean fluid-side surface. The passage has a first opening at the raw fluid-side surface provided with a first cross section and a second opening at the clean fluid-side surface provided with a second cross section. When projecting the first and second openings onto each other, one cross section, at least with sections thereof, is arranged outside of the other cross section.
Claims
1. A filter bellows comprising a filter medium folded in a zigzag shape, the filter bellows comprising oppositely positioned end edge faces formed of end edges of the filter medium and further comprising first and second fold edges extending between the oppositely positioned end edge faces, the filter bellows further comprising oppositely positioned end faces extending transversely to the end edge faces, wherein the end faces each comprise an end fold comprising a fold edge and a free end fold rim positioned opposite the fold edge of the end fold, wherein the filter bellows, in a state of use, comprises a raw fluid-side surface and a clean fluid-side surface opposite the raw fluid-side surface, wherein the first fold edges are positioned at the raw fluid-side surface and the second fold edges are positioned at the clean fluid-side surface, wherein the filter bellows comprises a passage extending between the raw fluid-side surface and the clean fluid-side surface, wherein the passage comprises a first opening, arranged at the raw fluid-side surface and comprising a first cross section, and further comprises a second opening, arranged at the clean fluid-side surface and comprising a second cross section, wherein, in a projection of the first and second openings onto each other, one of the first and second cross sections, at least with sections thereof, is arranged outside of the other one of the first and second cross sections.
2. The filter bellows according to claim 1, wherein the first opening comprises a contour that is different from a contour of the second opening.
3. The filter bellows according to claim 1, wherein the first and second fold edges are straight.
4. The filter bellows according to claim 1, wherein the passage interrupts at least one of the first fold edges at the first opening and further interrupts at least one of the second fold edges at the second opening.
5. The filter bellows according to claim 1, wherein the passage comprises, at least in a section thereof, a conical extension between the first opening and the second opening.
6. The filter bellows according to claim 1, wherein the passage comprises a wall comprising, at least in a section thereof, a stepped extension.
7. The filter bellows according to claim 1, wherein at least one of the end edge faces comprises a directional change.
8. The filter bellows according to claim 1, wherein at least one of the end faces comprises a directional change.
9. The filter bellows according to claim 1, wherein at least one of the end faces comprises a directional change and wherein at least one of the end edge faces comprises a directional change.
10. The filter bellows according to claim 1, wherein the passage is formed by laser cutting the filter medium.
11. The filter bellows according to claim 1, wherein the filter medium comprises cellulose.
12. The filter bellows according to claim 11, wherein the filter medium is made of cellulose.
13. A filter element for filtering a fluid, the filter element comprising a filter bellows, the filter bellows comprising a filter medium folded in a zigzag shape, the filter bellows comprising oppositely positioned end edge faces formed of end edges of the filter medium and further comprising first and second fold edges extending between the oppositely positioned end edge faces, the filter bellows further comprising oppositely positioned end faces extending transversely to the end edge faces, wherein the end faces each comprise an end fold comprising a fold edge and a free end fold rim positioned opposite the fold edge of the end fold, wherein the filter bellows, in a state of use, comprises a raw fluid-side surface and a clean fluid-side surface opposite the raw fluid-side surface, wherein the first fold edges are positioned at the raw fluid-side surface and the second fold edges are positioned at the clean fluid-side surface, wherein the filter bellows comprises a passage extending between the raw fluid-side surface and the clean fluid-side surface, wherein the passage comprises a first opening, arranged at the raw fluid-side surface and comprising a first cross section, and further comprises a second opening, arranged at the clean fluid-side surface and comprising a second cross section, wherein, in a projection of the first and second openings onto each other, one of the first and second cross sections, at least with sections thereof, is arranged outside of the other one of the first and second cross sections.
14. The filter element according to claim 13, wherein the filter bellows comprises a first circumferentially extending seal arranged at the end edges and the end fold rims at the raw fluid-side surface and/or at the clean fluid-side surface and further comprises a second circumferentially extending seal at the first opening and/or at the second opening of the passage.
15. The filter element according to claim 14, wherein the first and second circumferentially extending seals are foamed onto the filter bellows.
16. The filter element according to claim 13, wherein at least one of the end edge faces comprises a directional change.
17. The filter element according to claim 13, wherein at least one of the end faces comprises a directional change.
18. The filter element according to claim 13, wherein at least one of the end faces comprises a directional change and wherein at least one of the end edge faces comprises a directional change.
19. The filter element according to claim 13 embodied as a flat air filter.
20. A filter system comprising: a filter housing comprising at least a housing bottom part and a housing top part, wherein the housing bottom part and the housing top part are detachably and fluid-tightly connected to each other; a filter element exchangeably arranged in the filter housing, wherein the filter element fluid-tightly separates a raw fluid side from a clean fluid side in the filter housing; the filter element comprising a filter bellows; the filter bellows comprising a filter medium folded in a zigzag shape; the filter bellows comprising oppositely positioned end edge faces formed of end edges of the filter medium and further comprising first and second fold edges extending between the oppositely positioned end edge faces, the filter bellows further comprising oppositely positioned end faces extending transversely to the end edge faces, wherein the end faces each comprise an end fold comprising a fold edge and a free end fold rim positioned opposite the fold edge of the end fold, wherein the filter bellows, in a state of use, comprises a raw fluid-side surface and a clean fluid-side surface opposite the raw fluid-side surface, wherein the first fold edges are positioned at the raw fluid-side surface and the second fold edges are positioned at the clean fluid-side surface, wherein the filter bellows comprises a passage extending between the raw fluid-side surface and the clean fluid-side surface, wherein the passage comprises a first opening, arranged at the raw fluid-side surface and comprising a first cross section, and further comprises a second opening, arranged at the clean fluid-side surface and comprising a second cross section, wherein, in a projection of the first and second openings onto each other, one of the first and second cross sections, at least with sections thereof, is arranged outside of the other one of the first and second cross sections.
21. The filter system according to claim 20, wherein the filter housing further comprises a reinforcement center support supported at the housing bottom part and/or at the housing top part, wherein the reinforcement center support is arranged in the passage when the filter element is installed in the filter housing.
22. The filter system according to claim 21, wherein the passage is embodied as a clean air outlet of the filter system.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0032] Further advantages result from the following drawing description. In the drawings, embodiments of the invention are illustrated. The drawings, the description, and the claims contain numerous features in combination. A person of skill in the art will also expediently consider the features individually and combine them to meaningful additional combinations.
[0033] FIG. 1 shows a plan view of a filter bellows according to an embodiment of the invention with a slanted passage.
[0034] FIG. 2 shows a cross section along the line II-II of the filter bellows of FIG. 1.
[0035] FIG. 3 is an isometric illustration of the filter bellows of FIG. 1.
[0036] FIG. 4 shows a plan view of a filter bellows according to another embodiment of the invention with a stepped passage.
[0037] FIG. 5 shows a cross section along the line V-V of the filter bellows of FIG. 4.
[0038] FIG. 6 is an isometric illustration of the filter bellows of FIG. 4.
[0039] FIG. 7 shows a plan view of a filter bellows according to a further embodiment of the invention with a passage that extends at a slant in a section thereof.
[0040] FIG. 8 shows a cross section along the line VII-VII of the filter bellows of FIG. 7.
[0041] FIG. 9 is an isometric illustration of the filter bellows of FIG. 7.
[0042] FIG. 10 shows a plan view of the filter bellows according to a further embodiment of the invention with a stepped passage extending at a slant.
[0043] FIG. 11 shows a cross section along the line XI-XI of the filter bellows of FIG. 10.
[0044] FIG. 12 is an isometric illustration of the filter bellows of FIG. 10.
[0045] FIG. 13 shows a plan view of a filter bellows according to a further embodiment of the invention with a passage that in a section thereof extends at a slant and conical.
[0046] FIG. 14 shows a cross section along the line XIV-XIV of the filter bellows of FIG. 13.
[0047] FIG. 15 is an isometric illustration of the filter bellows of FIG. 13.
[0048] FIG. 16 shows a plan view of a filter bellows according to a further embodiment of the invention with a passage that in a section thereof extends conically.
[0049] FIG. 17 shows a cross section along the line XVII-XVII of the filter bellows of FIG. 16.
[0050] FIG. 18 is an isometric illustration of the filter bellows of FIG. 16.
[0051] FIG. 19 is an isometric illustration of a filter element according to an embodiment of the invention with a filter bellows with two oval passages.
[0052] FIG. 20 is an isometric illustration of a filter system according to an embodiment of the invention.
[0053] FIG. 21 shows a longitudinal section of the filter system according to FIG. 20 with sectioned filter element.
[0054] FIG. 22 shows details of a longitudinal section of the filter system according to FIG. 20 with a filter element sectioned at a passage of the filter bellows.
DESCRIPTION OF PREFERRED EMBODIMENTS
[0055] In the Figures, same or same-type components are identified with same reference characters. The Figures show only examples and are not to be understood as limiting.
[0056] In FIGS. 1 to 3, different views of a filter bellows 12 according to an embodiment of the invention with a slanted passage 50 through the filter bellows are illustrated. FIG. 1 shows a plan view of the filter bellows 12, FIG. 2 a cross section along the line II-II, and FIG. 3 an isometric illustration. The filter bellows 12, that is configured in particular for an air filter system, comprises a filter medium 14 folded in a zigzag shape, wherein the fold edges 26 extend respectively between oppositely positioned end edge faces 20a, 20b formed of end edges 22a, 22b of the filter medium, and wherein at oppositely positioned end faces 36, 38 an end fold 24 with a fold edge 26 and an oppositely positioned free end fold rim 30 is arranged, respectively. First fold edges 26 are positioned at a raw fluid-side surface 44 that faces, in the installed state of use of the filter bellows, the raw fluid side and second fold edges 26 are positioned at an oppositely positioned clean fluid-side surface 46 that is facing the clean fluid side in the installed state of use of the filter bellows. A passage 50 is formed between the raw fluid-side surface 44 and the clean fluid-side surface 46; the passage 50 is provided with a raw fluid-side opening 60 with a raw fluid-side cross section 54 and with a clean fluid-side opening 62 with a clean fluid-side cross section 56. The extension of the passage 50 through the filter bellows 12 is such that, in a projection of the openings 60, 62 onto each other, one of the cross sections 54, 56 is arranged outside of the other one of the cross sections 56, 54. The passage 50 extends at a slant through the filter bellows 12 so that the openings 60, 62 in the projection are even positioned adjacent to each other, and the passage 50 is in the form of a round channel. The passage 50 cuts through the filter bellows 12 from the raw fluid-side surface 44 to the clean fluid-side surface 46. This means that the passage 50 in the region of its raw fluid-side opening 60 interrupts at least one raw fluid-side fold edge 26 and in the region of its clean fluid-side opening 62 at least one clean fluid-side fold edge 26. Preferably, in the region of the passage 50 and its openings 60, 62 at both ends of the passage 50, several adjacently positioned folds and thus also adjacently positioned fold edges 26 are interrupted at both ends of the passage 50.
[0057] The passage 50 can be formed, for example, by laser cutting the filter medium 14. The filter medium 14 comprises, for example, cellulose and/or is made of cellulose. The end edge face 20a is subjected to a directional change, i.e., deviates from a purely parallelepipedal shape so that the filter bellows 12 can be fitted into an installation space designed accordingly. The folds 34 of the filter medium 14 are illustrated only in one part of the filter bellows 12; the remainder of the filter bellows 12 that also comprises the filter medium 14 folded in a zigzag shape is illustrated only purely schematically.
[0058] In FIGS. 4 to 6, different views of a filter bellows 12 according to another embodiment of the invention with a stepped passage 50 through the filter bellows 12 are illustrated. FIG. 4 shows a plan view of the filter bellows 12, FIG. 5 a cross section along the line V-V, and FIG. 6 an isometric illustration. The passage 50 comprises thus at least in a section thereof a stepped extension of its wall 48 in two steps. The projection of the raw fluid-side opening 60 onto the raw fluid-side surface 44 and the projection of the clean fluid-side opening 62 onto the raw fluid-side surface 44 overlap thus partially.
[0059] In FIGS. 7 to 9, different views of a filter bellows 12 according to a further embodiment of the invention with a passage 50 that extends in a section thereof at a slant are illustrated. FIG. 7 shows a plan view of the filter bellows 12, FIG. 8 a cross section along the line VIII-VIII, and FIG. 9 an isometric illustration. The projections of the two openings 60, 62 onto each other are positioned partially displaced adjacent to each other. The passage 50 is designed such that the raw fluid-side cross section 54 and the clean fluid-side cross section 56 are of the same size. The passage 50 extends in an inner region at a slant and connects in this way the two openings 60, 62 where the passage 50 is embodied in a first section perpendicular to the surfaces 44, 46, respectively.
[0060] In FIGS. 10 to 12, different views of a filter bellows 12 according to a further embodiment of the invention with a passage 50 that is extending stepped and at slant are illustrated. FIG. 10 shows a plan view of the filter bellows 12, FIG. 11 a cross section along the line XI-XI, and FIG. 12 an isometric illustration. The projections of the two openings 60, 62 onto each other are positioned displaced adjacent to each other. The passage 50 is designed such that the raw fluid-side cross section 54 and the clean fluid-side cross section 56 are of the same size. The passage 50 extends in an inner region in two steps at a slant and connects thus the two openings 60, 62.
[0061] In FIGS. 13 to 15, different views of a filter bellows 12 according to a further embodiment of the invention with a passage 50 that is extending in a section thereof at a slant and conically are illustrated. FIG. 13 shows a plan view of the filter bellows 12, FIG. 14 a cross section along the line XIV-XIV, and FIG. 15 an isometric illustration. The projections of the two openings 60, 62 onto each other are positioned partially displaced adjacent to each other. The raw fluid-side opening 60 with regard to its contour is different from the contour of the clean fluid-side opening 62 and is significantly smaller in regard to diameter. The passage 50 comprises in a section thereof a slanted and conical extension between the raw fluid-side opening 60 and the clean fluid-side opening 62.
[0062] In FIGS. 16 to 18, different views of a filter bellows 12 according to a further embodiment of the invention with a passage 50 that extends in a section thereof conically are illustrated. FIG. 16 shows a plan view of the filter bellows 12, FIG. 17 a cross section along the line XVII-XVII, and FIG. 18 an isometric illustration. The projections of the two opening 60, 62 onto each other are centric. The raw fluid-side opening 60 with respect to its contour is embodied different from the contour of the clean fluid-side opening 62 and in particular embodied significantly smaller in regard to diameter so that the opening 60 in projection is lying within the interior of the projection of the opening 62. The passage 50 extends in a section thereof conically and extends perpendicular to the surfaces 44, 46 through the filter bellows 12.
[0063] FIG. 19 shows an isometric illustration of a filter element 10 according to an embodiment of the invention comprising a filter bellows 12 with two oval passages 50. The filter element 10 for filtering a fluid comprises a filter bellows 12 of a filter medium 14 folded in a zigzag shape, wherein fold edges 26 extend between oppositely positioned end edge faces 20a, 20b formed of end edges 22a, 22b, respectively, and wherein an end fold 24 with a fold edge 26 and an oppositely positioned free end fold rim 30 is arranged at oppositely positioned end faces 36, 38, respectively, and first fold edges 26 are positioned at a raw fluid-side surface 44 in the installed state of use and second fold edges 26 at an oppositely positioned clean fluid-side surface 46 in the installed state of use. Two passages 50 are formed between the raw fluid-side surface 44 and the clean fluid-side surface 46 with a raw fluid side opening 60 with a raw fluid-side cross section 54 and a clean fluid-side opening 62 (not visible) with a clean fluid-side cross section 56, respectively, wherein in a projection of the openings 60, 62 onto each other at least one of the cross sections 54, 56 is at least with sections thereof arranged outside of the other one of the cross sections 56, 54. The filter bellows 12 comprises a circumferentially extending seal 40 at end edges 22a, 22b and at end fold rims 30 of the raw fluid-side surface 44 as well as a circumferentially extending seal 41 at the raw fluid-side opening 60 of the passages 50. The seals 40, 41 are foamed onto the filter bellows 12 and are comprised, for example, of PUR foam. The end edge face 20a is subjected to a directional change so that the filter element 10 can be fitted into a correspondingly designed installation space. The filter element 10 can be used, for example, as a flat air filter, in particular of an internal combustion engine, in particular of a motor vehicle.
[0064] FIG. 20 shows an isometric illustration of a filter system 100 according to an embodiment of the invention. The filter system 100 comprises a filter element 10 in a filter housing 102 that is comprised of a housing bottom part 104 and a housing top part 106 which are connected fluid-tightly to each other, for example, screwed together. The filter housing 102 comprises an inlet 108 and an outlet 109 for the fluid to be filtered.
[0065] FIG. 21 shows in this context a longitudinal section of the filter system 100 according to FIG. 20 with sectioned filter element 10. The filter element 10 is arranged exchangeably in the filter housing 102 that comprises the housing bottom part 104 and the housing top part 106 which, by means of a screw connection, are detachably but fluid-tightly connected to each other. The filter element 100 fluid-tightly separates in this context the raw fluid side 110 from the clean fluid side 112 of the filter system 100. The filter element 10 is arranged with the circumferentially extending seal 40 at the separation location between housing bottom part 104 and housing top part 106 of the filter housing 102 and is seated with the seal 40 on the housing bottom part 104. In this way, with the circumferentially extending seal 40 of the filter element 10 also the filter housing 102 can be sealed upon placement of the housing top part 106 onto the housing bottom part 104.
[0066] In FIG. 22, details of a longitudinal section of the filter system 100 according to FIG. 20 with a filter element 10 sectioned at a passage 50 of the filter bellows 12 are illustrated. A reinforcement center support 80 which is supported at the housing bottom part 104 and housing top part 106 is arranged in the passage 50 when the filter element is installed. For reinforcement, the filter housing 102 comprises at its center point the reinforcement center support 80 which is comprised of a hollow socket 82 fastened to the housing bottom part 104 and a threaded socket 84 which is fastened to the housing top part 106. The sockets 82, 84 are connected to each are by a connecting screw 86 after the housing top part 106 has been placed onto the housing bottom part 104. In this context, the reinforcement center support 80 extends through a passage 50 provided in the filter bellows 12 which is sealed by a seal 41 relative to the reinforcement center support 80. By means of the seal 41, a consequent sealing action between raw fluid side 110 and clean fluid side 112 is provided also in the region of the passage 50.
[0067] The construction of the reinforcement center support 80, comprised of hollow socket 82 and threaded socket 84, can be seen in FIG. 22. These two components form a receptacle 88 for the seal 41. By tightening the connecting screw 86, which is inserted from the exterior into the hollow socket 82 and subsequently is screwed into the threaded socket 84, the seal 41 is deformed in the receptacle 88 so that the sealing action is realized. For a subsequent demounting of the filter element 10, the hollow socket 82 is thus provided with a captive securing action 90 in which the screw remains after unscrewing from the threaded socket 84.
