Filtration system, filter element and use

Abstract

A filtration system (1A, 1B, 1C) having a filter housing (2) comprising a fluid inlet (14) for guiding a fluid (L) into the filter housing (2), a fluid outlet (3) for guiding the fluid (L) out of the filter housing (2), a filter element (34) removably housed in the filter housing (2) and comprising a positioning and sealing portion (41) for positioning and sealing the filter element (34) with respect to the filter housing (2), and elastically deformable snap elements (17) by means of which the filter housing (2) and the fluid outlet (3) are tightly connected to each other, the positioning and sealing portion (41) being radially pressed against the snap elements (17).

Description

Technical field

[0001] The present invention relates to a filter system and a filter element of such a filter system, as well as the use of a filter element in such a filter system. State of the art

[0002] A filter system can comprise a filter housing and a removable filter element with a pleated filter medium, which is housed within the filter housing. The filter housing includes a fluid inlet for supplying the fluid to be cleaned to the filter element. A fluid outlet is provided for discharging the fluid cleaned of particles. The fluid outlet can be a tubular component that is locked or snapped into place with a lower part of the filter housing.Such snap-fit ​​or detent connections are known from the prior art, for example from DE 11 2012 004 521 T5 or US 2020 / 0155988 A1, in which the fluid outlet has a circumferential, annular detent edge. A plurality of elastically deformable snap elements, arranged circumferentially on the lower part of the filter housing, engage behind this edge. During assembly, these snap elements are temporarily deformed radially outwards. When the fluid outlet is inserted into the lower part of the housing, they are moved over the detent edge. After passing over the detent edge, they move radially inwards again and engage or snap behind or at the detent edge. Vibrations during operation of the filter system can cause small relative movements between the fluid outlet and the lower part of the housing, particularly in the area of ​​the snap connection. These relative movements can lead to noise generation.Furthermore, these relative movements can also lead to wear on the fluid outlet and / or the lower part of the housing. This must be avoided.

[0003] Further generic filter elements are known from US 2012 / 031060 A1, DE 11 2012 004 521 T5 and DE 10 2008 008 328 A1. Disclosure of the invention

[0004] Against this background, the present invention aims to provide an improved filter system.

[0005] Accordingly, a filter system is proposed comprising a filter housing which includes a fluid inlet for introducing a fluid into the filter housing, a fluid outlet for discharging the fluid from the filter housing, a removable filter element held in the filter housing which includes a positioning and sealing section for positioning and sealing the filter element against the filter housing, and elastically deformable snap elements by means of which the filter housing and the fluid outlet are positively connected to each other, wherein the positioning and sealing section in particular bears radially against the snap elements and is preferably pressed against the snap elements, in particular radially pressed against the snap elements.

[0006] Because the positioning and sealing section is pressed radially against the snap elements, it provides support and damping to the snap elements, preventing them from moving relative to each other during operation of the filter system, for example, due to vibrations. This reliably prevents noise, such as rattling of the snap elements, and wear on the snap elements.

[0007] Preferably, the snap elements engage in a form-fitting manner in an engagement section to create a form-fitting connection between the filter housing and the fluid outlet.

[0008] Preferably, the snap elements have a side facing the engagement section and a side facing away from the engagement section. Preferably, the positioning and sealing section rests radially against the sides of the snap elements facing away from the engagement section.

[0009] The filter system is preferably an air filter system. Accordingly, the filter element is an air filter element. The filter system is, for example, an intake air filter for an internal combustion engine. The filter housing preferably comprises a pot-shaped lower housing section and a housing upper section that is removable from the lower housing section. The filter element can be removed from the filter housing and replaced. The fluid inlet is preferably tubular. For example, the fluid inlet is arranged laterally on the lower housing section. The fluid to be cleaned thus flows, in particular perpendicular to an axis of symmetry of the filter system, against the filter medium. The cleaned fluid leaves the filter housing through the fluid outlet. The fluid outlet is, in particular, attached to the lower housing section. The fluid outlet can be part of the filter housing, in particular the lower housing section.

[0010] However, this does not preclude the possibility that the fluid outlet can be separated from the filter housing, especially from the lower part of the housing, particularly without damage.

[0011] The filter medium is preferably a zigzag-folded bellows. The filter medium can be cylindrical. Viewed along the axis of symmetry, the filter medium is arranged between a first end plate and a second end plate. The end plates are attached to the end faces of the filter medium. In particular, the end plates are firmly connected to the filter medium. The end plates are preferably made of an elastically deformable plastic material, such as polyurethane. For example, the end plates can be cast or fused to the filter medium. The end plates can, for example, be made of foamed polyurethane.

[0012] The first end plate preferably has a central opening through which the fluid outlet is introduced into the filter housing, and in particular into the filter element. The second end plate is preferably fluid-tight and seals the filter medium at its end. Preferably, the first end plate has a positioning and sealing section that runs annularly around the axis of symmetry. The positioning and sealing section can have recesses or indentations on its outer side, i.e., facing away from the axis of symmetry, into which corresponding engagement elements of the lower housing part can engage in a form-fitting manner. This allows, firstly, the positioning of the filter element relative to the lower housing part to be achieved, and secondly, prevents filter elements not belonging to the filter system from being mounted in the lower housing part without such recesses.

[0013] The fluid, which is to be cleaned of particles such as dust, small stones, plant matter, or the like, is introduced into the filter housing through the fluid inlet. The fluid to be cleaned then flows from a raw side of the filter element through the filter medium to a clean side of the filter element. From the clean side, the cleaned fluid exits the filter system via the fluid outlet and is supplied, for example, to an internal combustion engine. The fluid is typically air.

[0014] The snap elements can be located either on the filter housing, particularly on the lower part of the housing, or at the fluid outlet. Furthermore, the snap elements can also be separate components. The snap elements are elastic, in particular elastically deformable. This means that the snap elements can be moved from an undeformed or undeformed state to a deformed or deformed state. However, the snap elements are pre-tensioned in the direction of the undeformed state, in particular spring-loaded. This means that a force is applied to the snap elements to move them from the undeformed state to the deformed state. As soon as this force is released, the snap elements deform or move themselves back from the deformed state to the undeformed state.

[0015] A positive-locking connection is created by the interlocking or overlapping of at least two connecting partners, in this case the snap elements and the filter housing or the snap elements and the fluid inlet. A positive-locking connection can preferably be separated non-destructively. The fact that the positioning and sealing section bears "radially" against the snap elements preferably means that the positioning and sealing section bears against the snap elements by force and / or form locking, in particular by damping to dampen movements and / or vibrations of the snap elements, which can arise, for example, from external excitation such as vibrations during operation. The fact that the positioning and sealing section is pressed "radially" against the snap elements means that the positioning and sealing section applies a force to the snap elements oriented in or against a radial direction of the filter system.The radial direction is perpendicular to the axis of symmetry and preferably directed away from it. The radial direction can also be oriented towards the axis of symmetry. The fact that the positioning and sealing section is "pressed" against the snap elements means, in this case, that the positioning and sealing section is pressed against the snap elements in such a way that it is elastically deformed and, in particular, exerts a radially acting force on the snap elements.

[0016] The snap elements are provided on a lower housing part of the filter housing, engaging positively in a section provided at the fluid outlet. Alternatively, the snap elements can also be provided at the fluid outlet, engaging in a section provided at the lower housing part. The engagement section is preferably an annular groove circumferentially around the aforementioned axis of symmetry, which is integrally formed on the fluid outlet. Alternatively, the engagement section can be an annular edge on the lower housing part, which is overcome during the installation of snap elements arranged at the fluid outlet and, in the assembled state, is positively engaged by snap elements arranged at the fluid outlet. To connect the fluid outlet to the lower housing part, the fluid outlet is guided through an outlet opening provided at the lower housing part.The snap elements are deformed elastically until they snap or lock into the engagement section, thus positively connecting the fluid outlet to the lower housing part. Preferably, the snap elements are deformed elastically in a release direction, particularly radially inwards or outwards, until they snap or lock into the engagement section in a direction opposite to the release direction, thus positively connecting the fluid outlet to the lower housing part. The fluid outlet can preferably only be separated from the lower housing part by deforming the snap elements, for example with the aid of a tool, and disengaging them from the engagement section.

[0017] The snap elements are inclined at an angle relative to an axis of symmetry of the filter system. The number of snap elements is arbitrary. For example, thirteen such snap elements are provided, evenly distributed around the axis of symmetry. The snap elements preferably project radially into the outlet opening of the lower housing part. The snap elements can, for example, and preferably, extend along the surface of a cone and / or at least partially form an outer surface of a truncated cone. It should be understood that even if this results in a radial component to part of the direction of extension of the snap elements, the snapping movement (in / against the release direction) occurs essentially in a radial direction, and the contact or compression of the positioning and sealing section against the snap elements takes place in a functionally relevant radial direction.However, this can also occur at an inclination of 45° to the central axis. Therefore, in these cases, one can still speak of radial installation or radial pressing, since a significant directional component is oriented radially.

[0018] In some embodiments, a slit-shaped gap is provided between two adjacent snap elements. That is, the snap elements and the gaps are arranged alternately. The gaps are preferably oriented along planes running through the central axis of the filter housing. This allows for individual snapping movements of the individual snap elements.

[0019] Preferably, each snap element has a side facing the positioning and sealing section and a side facing away from it. Preferably, the side facing away from the positioning and sealing section faces the engagement section. Preferably, each snap element has an outer surface facing the positioning and sealing section and an inner surface facing away from it. The positioning and sealing section rests against the outer surfaces of the snap elements. Alternatively, if the snap elements are arranged radially outside the positioning and sealing section, each snap element has an inner surface facing the positioning and sealing section and an outer surface facing away from it. In this case, the positioning and sealing section rests against the inner surfaces of the snap elements.

[0020] Preferably, the release direction in the assembled state corresponds to a direction of movement facing the positioning and sealing section. This means that, in the assembled state or during operation, the part of the positioning and sealing section that rests against the snap elements can dampen and / or impede movement of the snap elements in the release direction.

[0021] The positioning and sealing section comprises a contact surface that rests radially against the snap elements or is pressed radially against them, and which is also inclined at an angle relative to the axis of symmetry. The contact surface rests against the aforementioned outer or, alternatively, inner surfaces of the snap elements and presses them against the engagement section of the fluid outlet.

[0022] In some embodiments, the snap-in elements and an annular receiving flange provided on the lower housing part form a connection interface of the lower housing part. The receiving flange preferably extends completely around the axis of symmetry. In particular, the receiving flange extends around the outlet opening of the lower housing part.

[0023] In some embodiments, the engagement section and a disc-shaped flange provided at the fluid outlet form a mating interface of the fluid outlet, wherein the interface and the mating interface interact such that the snap elements engage positively in the engagement section and the flange is received in the receiving flange. In particular, when the flange is received in the receiving flange, it rests against the end face of the lower housing part, especially against a bottom section of the lower housing part. The flange extends radially laterally out of the fluid outlet and, in particular, completely surrounds it.

[0024] In some embodiments, the fluid outlet is rotatable relative to the lower housing. This makes it possible to adapt the filter system to different applications or installation situations. In particular, the fluid outlet is rotatably mounted in or on the lower housing.

[0025] The fluid outlet comprises a sealing interface with which a corresponding sealing interface of the positioning and sealing section is radially pressed. The sealing interface preferably comprises a cylindrical sealing surface circumferentially around the axis of symmetry, against which a corresponding, also preferably cylindrical, sealing surface of the sealing interface can be radially pressed. Furthermore, the sealing interface preferably comprises a rib extending radially beyond the sealing surface, which preferably circumferentially completely around the axis of symmetry. The rib preferably engages in a positive-locking manner with a preferably provided, corresponding groove of the sealing interface. This enables axial positioning of the filter element at the fluid outlet.

[0026] The positioning and sealing section has a sealing interface with a cylindrical sealing surface and a contact surface. Preferably, the contact surface abuts axially on the side of the sealing surface facing away from the filter element, particularly directly, and more preferably forms a frustoconical ring. The positioning and sealing section is designed as an annular bead extending axially away from an open end disk of the filter element, and preferably formed integrally with it. The cylindrical sealing surface and the contact surface are arranged on the radially inner side of the annular bead; alternatively, the cylindrical sealing surface of the positioning and sealing section can be arranged on the radial inner side of the annular bead and the contact surface on the radial outer side of the annular bead, or at least formed by them.

[0027] In embodiments, the fluid outlet comprises a grid-shaped support tube section that projects into the filter element and a nozzle section, in particular curved by 90°, that projects from the filter housing. The support tube section is suitable for supporting the filter medium from within during operation of the filter system. The cleaned fluid is discharged from the filter system by means of the nozzle section. The nozzle section can extend along the axis of symmetry or be curved by 90° and thus be positioned perpendicular to the axis of symmetry.

[0028] Furthermore, a filter element for such a filter system is proposed. As mentioned previously, the filter element is, in particular, an air filter element. The filter element comprises the first end disk and the second end disk, between which the filter medium is arranged. The positioning and sealing section is specifically formed on the first end disk.

[0029] Furthermore, the use of a filter element in such a filter system is proposed. As mentioned previously, the filter element is, in particular, an air filter element. The filter element comprises the first end disk and the second end disk, between which the filter medium is arranged. The positioning and sealing section is specifically molded onto the first end disk. Brief description of the drawings

[0030] It shows: Fig. 1: a schematic perspective view of an embodiment of a filter system; Fig. 2: a schematic partial sectional view of the filter system according to the Fig. 1 Fig. 3: a schematic sectional view of the filter system according to the Fig. 1 Fig. 4: Detail view IV according to the Fig. 3 Fig. 5: another schematic sectional view of the filter system according to the Fig. 1 Fig. 6: a schematic sectional view of an embodiment of a filter housing for the filter system according to the Fig. 1; Fig. 7: Detail view VII according to the Fig. 6 Fig. 8: a schematic sectional view of an embodiment of a fluid outlet for the filter system according to the Fig. 1 Fig. 9: a schematic sectional view of another embodiment of a filter system; Fig. 10: the detail view X according to the Fig. 9 ; and Fig. 11: a schematic sectional view of another embodiment of a filter system.

[0031] In the figures, identical or functionally equivalent elements have been provided with the same reference symbols unless otherwise indicated. embodiment(s) of the invention

[0032] The Fig. 1 Figure 1 shows a schematic perspective view of an embodiment of a filter system 1A. Fig. 2 shows a schematic partial sectional view of filter system 1A. Fig. 3 shows a schematic sectional view of filter system 1A. Fig. 4 The detailed view IV shows according to the Fig. 3 . The Fig. 5 shows another schematic sectional view of filter system 1A. Fig. 6 Figure 1 shows a schematic sectional view of an embodiment of a filter housing 2 for the filter system 1A. Fig. 7 The detailed view VII shows according to the Fig. 6 . The Fig. 8 Figure 1 shows a schematic sectional view of an embodiment of a fluid outlet 3 for the filter system 1A. The following refers to the Figs. 1 to 8 Reference was made at the same time.

[0033] Filter system 1A can also be referred to as a filter assembly. Filter system 1A can be used as an intake air filter for internal combustion engines, for example in motor vehicles, trucks, construction vehicles, watercraft, rail vehicles, agricultural machinery, or aircraft. Filter system 1A is particularly suitable for heavy-duty applications. It can also be used in stationary applications, such as in building technology. Filter system 1A is especially suitable for filtering the intake air of an internal combustion engine. Preferably, filter system 1A is an air filter system.

[0034] The filter housing 2 comprises a lower housing part 4 and an upper housing part 5. The upper housing part 5 can also be referred to as the housing cover. The upper housing part 5 can be removed from and reattached to the lower housing part 4. A sealing element, for example in the form of an O-ring, can be provided between the lower housing part 4 and the upper housing part 5. The upper housing part 5 can have quick-release fasteners 6, of which in the Fig. 1 and 2 Only one of them is marked with a reference symbol. The number of quick-release fasteners 6 is arbitrary. For example, three such quick-release fasteners 6 are provided, evenly distributed around a central or symmetry axis 7 of the filter system 1A.

[0035] The upper housing part 5 can be detachably connected to the lower housing part 4 using the quick-release fasteners 6. For this purpose, the lower housing part 4 can be provided with engagement sections, for example in the form of hooks or shoulders, into which the quick-release fasteners 6 engage to connect the upper housing part 5 to the lower housing part 4 in a form-fitting manner. A form-fitting connection is created by the interlocking or overlapping of at least two connecting partners, in this case the quick-release fasteners 6 and the engagement sections. For example, the upper housing part 5 is an injection-molded plastic component.

[0036] A dust discharge nozzle 8 is provided on the upper part 5 of the housing. The dust discharge nozzle 8 is oriented perpendicular to the axis of symmetry 7. A dust discharge valve 9 is attached to the dust discharge nozzle 8. The dust discharge valve 9 allows separated coarse particles, such as dust, small stones, plant matter, or the like, to be discharged from the filter housing 2. For example, the dust discharge valve 9 can be opened by means of a load change of an internal combustion engine located downstream of the filter system 1A.

[0037] The lower housing part 4 is cup-shaped and comprises a cylindrical base section 10, which is rotationally symmetrical about the axis of symmetry 7. The end face of the base section 10 is closed by means of a bottom section 11. The base section 10 and the bottom section 11 are formed as a single unit, specifically as a single piece of material. "Single unit" or "one-piece" in this context means that the base section 10 and the bottom section 11 form a single component and are not composed of different individual components. "One-piece" in this context means that the base section 10 and the bottom section 11 are manufactured entirely from the same material. For example, the lower housing part 4 is an injection-molded plastic component.

[0038] A flow guard 13 extends from the base section 11 and into an interior space 12 of the lower housing part 4. The flow guard 13 is hollow cylindrical and rotationally symmetrical about the axis of symmetry 7. The flow guard 13 is formed integrally, specifically integrally, with the base section 11.

[0039] A fluid inlet 14 is integrally formed on the base section 10. The fluid inlet 14 is oriented perpendicular to the axis of symmetry 7. The fluid inlet 14 is formed integrally, specifically of the same material, with the base section 10. Looking from the axis of symmetry 7 towards the fluid inlet 14, the flow guard 13 covers the fluid inlet 14. This prevents a filter element, which will be explained later, from being directly exposed to a fluid L to be cleaned, for example, air, flowing into the filter housing 2 through the fluid inlet 14.

[0040] The bottom section 11 has a substantially circular outlet opening 15 that penetrates the bottom section 11. The outlet opening 15 is rotationally symmetrical about the axis of symmetry 7. The outlet opening 15 forms an inner surface 16 that completely surrounds the axis of symmetry 7. The inner surface 16 is inclined or obliquely arranged with respect to the axis of symmetry 7.

[0041] Snap elements 17 protrude into the outlet opening 15, of which in the Fig. 6 and 7Only one of each snap element is marked with a reference numeral. The snap elements 17 are formed integrally, in particular integrally with the base section 11. The number of snap elements 17 is arbitrary. For example, thirteen snap elements 17 are provided, which are evenly distributed around the axis of symmetry 7. A slit-shaped gap 18 is provided between each pair of adjacent snap elements 17. This means that the snap elements 17 and the gaps 18 are arranged alternately.

[0042] The snap elements 17 are spring-elastic and deformable and can be moved from one to the Fig. 6 and 7The snap elements 17 are moved from the undeformed state shown to a deformed state (not shown) and back again. They are pre-tensioned in the direction of the undeformed state, specifically spring-loaded. This means that the snap elements 17 can be moved from the undeformed state to the deformed state by applying a force. As soon as this force is removed, the snap elements 17 automatically deform back from the deformed state to the undeformed state.

[0043] The snap elements 17 are inclined at an angle α to the axis of symmetry 7. Each snap element 17 has an outer surface 19 facing the inner surface 16 and an inner surface 20 facing away from the inner surface 16. The outer surfaces 19 and the inner surfaces 20 are each inclined at an angle α relative to the axis of symmetry 7.

[0044] A receiving flange 21, extending completely around the axis of symmetry 7, is provided on the base section 11. The receiving flange 21 is annular and extends out of the base section 11, facing away from the interior 12. The snap elements 17 and the receiving flange 21 together form a connection interface 22, which, in a manner to be explained later, is suitable for interacting with the fluid outlet 3 to positively connect it to the lower housing part 4. A flange 23, extending completely around the axis of symmetry 7, is integrally formed on the base section 10, facing away from the base section 11, to which the upper housing part 5 can be flanged.

[0045] Returning to the fluid outlet 3, this outlet is suitable for supplying purified fluid L, for example air, from the filter housing 2 to, for example, an internal combustion engine. The fluid outlet 3 passes through the outlet opening 15 and is positively connected to the lower housing part 4. The fluid outlet 3 has a tubular central tube section or support tube section 24, which projects into the interior 12 and is rotationally symmetrical about the axis of symmetry 7. The support tube section 24 is fluid-permeable. For this purpose, the support tube section 24 has a grid-like structure and includes a multitude of openings or penetrations 25.

[0046] In addition to the support tube section 24, the fluid outlet 3 comprises a nozzle section 26, which is formed integrally, in particular integrally, with the support tube section 24. For example, the fluid outlet 3 is an injection-molded plastic component. The nozzle section 26 is oriented perpendicular to the axis of symmetry 7, thereby enabling a 90° redirection of the cleaned fluid L. The nozzle section 26 is located outside the interior 12. The fluid outlet 3 can be part of the filter housing 2. The fluid outlet 3 can also be straight instead of curved.

[0047] The fluid outlet 3 comprises a disc-shaped flange 27 that completely surrounds the axis of symmetry 7. The flange 27 is integrally formed on the upper side of the support tube section 24. The flange 27 can thus be positioned between the support tube section 24 and the nozzle section 26. The flange 27 can be received in the receiving flange 21 of the lower housing part 4.

[0048] In the orientation of Fig. 8 Below the flange 27, an engagement section 28 is provided into which the snap elements 17 can engage in a form-fitting manner. For this purpose, the engagement section 28 is designed as an annular groove extending completely around the axis of symmetry 7, which can be integrally formed on the upper side of the support tube section 24.

[0049] The flange 27 and the engagement section 28 form a connection interface 29 which is suitable to interact with the connection interface 22 to positively connect the fluid outlet 3 to the lower part of the housing 4.

[0050] To connect the fluid outlet 3 to the lower housing part 4, the support tube section 24 is inserted through the outlet opening 15 into the lower housing part 4 until the flange 27 of the connection interface 29 of the fluid outlet 3 is engaged in the receiving flange 21 of the connection interface 22 of the lower housing part 4. The flange 27 then rests against the end face of the bottom section 11. The snap elements 17 then engage or lock into the engagement section 28 of the connection interface 29, so that the fluid outlet 3 is positively connected to the lower housing part 4. The fluid outlet 3 can only be separated from the lower housing part 4 if the snap elements 17 are deformed, for example with the aid of a tool, so that they disengage from the engagement section 28. The fluid outlet 3 is rotatable relative to the lower housing part 4.

[0051] In the orientation of Fig. 8Below the engagement section 28, a cylindrical sealing surface 30 is provided at the fluid outlet 3, which completely surrounds the axis of symmetry 7. Adjoining the sealing surface 30 is a rib 31, also surrounding the axis of symmetry 7, which projects radially beyond the sealing surface 30 when viewed in a radial direction R. In the orientation of the Fig. 8 Below the rib 31, a cylindrical outer surface 32 is provided, which completely surrounds the axis of symmetry 7. The sealing surface 30, the rib 31, and the outer surface 32 form a sealing interface 33 of the fluid outlet 3, which is suitable for interacting with a filter element 34 of the filter system 1A that can be accommodated in the filter housing 2.

[0052] The filter element 34 is rotationally symmetrical about the axis of symmetry 7. The filter element 34 comprises a filter medium 35, which is cylindrical. The filter medium 35 is also rotationally symmetrical about the axis of symmetry 7. For example, the filter medium 35 can be closed in an annular form and be in the form of a star-shaped folded filter bellows. The filter medium 35 is thus preferably folded.

[0053] Filter element 34 is assigned a longitudinal direction LR. The longitudinal direction LR is oriented along the axis of symmetry 7. In the orientation of the Figs. 2 to 4 The longitudinal direction LR can be oriented from bottom to top. However, the longitudinal direction LR can also be oriented in the opposite direction. The filter medium 35 is assigned a first end face 36 and a second end face 37. The longitudinal direction LR can be oriented from the second end face 37 towards the first end face 36.

[0054] The filter medium 35 is, for example, filter paper, filter fabric, filter fleece, or filter nonwoven. In particular, the filter medium 35 can be manufactured using a spunbond or meltblown process, or comprise such a fiber layer applied to a nonwoven or cellulose support. Furthermore, the filter medium 35 can be felted or needle-punched. The filter medium 35 can contain natural fibers, such as cellulose or cotton, or synthetic fibers, for example, made of polyester, polyvinyl sulfite, or polytetrafluoroethylene. During processing, the fibers of the filter medium 35 can be oriented in the direction of, diagonally, and / or transversely, or randomly with respect to a machine direction.

[0055] The filter element 34 has a first, in particular open, end disk 38, which is provided at the first end face 36 of the filter medium 35. Furthermore, the filter element 34 comprises a second, in particular closed, end disk 39, which is provided at the second end face 37 of the filter medium 35. That is, the filter medium 35 is positioned between the first end disk 38 and the second end disk 39. The end disks 38, 39 can, for example, be made of a polyurethane material, preferably foamed, and in particular cast in molds. The end disks 38, 39 can be cast onto the filter medium 35. The first end disk 38 is connected to the first end face 36. The second end disk 39 is connected to the second end face 37.

[0056] The first end disk 38 includes a centrally arranged opening 40. The fluid outlet 3, in particular the support tube section 24, passes through the opening 40. The opening 40 can be an outflow opening of the filter element 34. The first end disk 38 is plate-shaped. Facing away from the first end face 36 of the filter medium 35, a positioning and sealing section 41 of the first end disk 38 extends outwards along the longitudinal direction LR, rotating in an annular shape around the axis of symmetry 7. The filter element 34 can be positioned in the filter housing 2 and sealed against it with the aid of the positioning and sealing section 41, as will be explained below. The opening 40 also penetrates the positioning and sealing section 41.

[0057] As the Fig. 4As shown, the first end disk 38, or the positioning and sealing section 41, comprises on its inner side, i.e., facing the opening 40, a cylindrical sealing surface 42, which is rotationally symmetrical about the axis of symmetry 7 and completely surrounds it. The sealing surface 42 is suitable for being pressed radially against the sealing surface 30 of the sealing interface 33 of the fluid outlet 3 in order to create a fluid-tight seal between the first end disk 38 and the sealing surface 30. "Radial" here means in the direction of the radial direction R, which is oriented perpendicular to and away from the axis of symmetry 7. Additionally, the first end disk 38 also seals axially, i.e., along the longitudinal direction LR, against the bottom section 11 by being pressed against the end face of the bottom section 11.

[0058] Furthermore, the first end disk 38 or the positioning and sealing section 41 comprises a contact surface 43 inclined at the angle α to the axis of symmetry 7 and completely circumferential around it, which rests on the outside, i.e. on the outer sides 19 of the snap elements 17, against the snap elements 17 and presses them into the engagement section 28 of the connection interface 29 of the fluid outlet 3.

[0059] This advantageously suppresses or at least reduces relative movements of the fluid outlet 3, for example due to vibrations, with respect to the lower housing part 4. This leads to noise reduction and reduced wear of the snap elements 17. The positioning and sealing section 41 thus provides support and damping against the snap elements 17. The positioning and sealing section 41 also prevents unwanted deformation of the snap elements 17 such that they become disengaged from the engagement section 28. Unintentional detachment of the fluid outlet 3 from the lower housing part 4 is therefore reliably prevented.

[0060] A groove 44, circumferential around the axis of symmetry 7, is formed on the sealing surface 42, into which the rib 31 of the sealing interface 33 of the fluid outlet 3 engages in a form-fitting manner. In the orientation of the Fig. 4Below the groove 44, an inner surface 45 is provided against which the outer surface 32 of the sealing interface 33 can abut. The sealing surface 42, the groove 44, and the inner surface 45 can form a sealing interface 46 of the filter element 34, which, in the manner described above, provides a fluid-tight seal with the sealing interface 33 of the fluid outlet 3. The contact surface 43 can also be part of the sealing interface 46.

[0061] On the outside, i.e. facing away from the sealing surface 42, the positioning and sealing section 41 rests against the inner surface 16 of the outlet opening 15 ( Fig. 2The positioning and sealing section 41 has a plurality of recesses or indentations 48 evenly distributed around the axis of symmetry 7, into which engagement elements provided on the inner surface 16 and extending radially in the direction of the axis of symmetry 7 engage in a form-fitting manner. With the aid of these recesses 48 and the engagement elements, precise angular positioning of the filter element 34 relative to the lower housing part 4 is possible. Furthermore, it is also possible to prevent filter elements not belonging to the filter system 1A from being installed in the lower housing part 4. Thus, the positioning and sealing section 41 fulfills not only a sealing function but also a positioning function.

[0062] Returning to the second end disk 39, which is also plate-shaped, this disk is rotationally symmetrical about the axis of symmetry 7 and seals the second end face 37 of the filter medium 35 in a fluid-tight manner. Positioning elements 47 extend from the second end disk 39 away from the second end face 37, of which in the Fig. 3 Only one is provided with a reference numeral. The number of positioning elements 47 is arbitrary. For example, five such positioning elements 47 can be provided, which are evenly distributed around the axis of symmetry 7.

[0063] The function of filter element 34 or filter system 1A is explained below using the following: Fig. 3The process is explained below. The fluid to be cleaned, for example air, is drawn into the filter housing 2, specifically into the interior 12, through the fluid inlet 14 and then passes from a raw side RO of the filter element 34 through the filter medium 35 to a clean side RL of the filter element 34, which is surrounded by the filter medium 35 or the support tube section 24. Particles, such as dust, are separated from the fluid L. The support tube section 24 provides internal support for the filter medium 35. The cleaned fluid L flows out of the filter housing 2 through the fluid outlet 3 of the filter element 34 and can, for example, be supplied to an internal combustion engine.

[0064] The Fig. 9 shows a schematic sectional view of another embodiment of a filter system 1B. Fig. 10 The detailed view X shows according to the Fig. 9 The following refers to the Fig. 9 and 10Reference is made to both at the same time. The following discussion focuses solely on the differences between filter system 1B and filter system 1A.

[0065] In filter system 1B, the fluid outlet 3 does not include a support tube section 24. Instead, a secondary filter element 49 is provided, which is integrated into the filter element 34. The secondary filter element 49 is positively connected to the fluid outlet 3, for example, by snapping it into place. The secondary filter element 49 includes a rib 50 that extends around the axis of symmetry 7 and engages positively in the groove 44 of the positioning and sealing section 41 of the first end disk 38, sealing radially against it. The fluid outlet 3 is straight and does not have a curvature, but extends along the axis of symmetry 7.

[0066] The snap elements 17 are not located on the lower housing part 4, but rather on the fluid outlet 3, and are positively locked to the lower housing part 4. The positioning and sealing section 41 presses against the snap elements 17 from the inside along the radial direction R, preventing the positive connection between the fluid outlet 3 and the lower housing part 4 from unintentionally disengaging. In the illustrated embodiment, the positioning and sealing section 41 has notches 339 on its radial outer surface, as known, for example, from WO2012172019A1, wherein the Figs. 9 - 11The sections shown in the illustration each pass through such a notch. In the areas of the notches 339, the radial extent of the positioning and sealing section 41 is reduced. In the areas 340 of the positioning and sealing section 41, in which no notch 339 is arranged, the positioning and sealing section 41 presses against the snap elements 17 from the inside along the radial direction R or at least rests against them.

[0067] The Fig. 11 Figure 1 shows a schematic sectional view of another embodiment of a filter system 1C. The filter system 1C differs from the filter system 1B only in that the fluid outlet 3 is curved by 90° as in the filter system 1A and is thus oriented perpendicular to the axis of symmetry 7. Reference symbols used:

[0068] 1A Filter system 1B Filter system 1C Filter system 2 Filter housing 3 Fluid outlet 4 Housing lower part 5 Housing upper part 6 Quick-release fastener 7 Axis of symmetry 8 Dust discharge nozzle 9 Dust discharge valve 10 Base section 11 Bottom section 12 Interior 13 Flow guard 14 Fluid inlet 15 Outlet opening 16 Inner surface 17 Snap-on element 18 Space 19 Outer side 20 Inner side 21 Mounting flange 22 Connection interface 23 Flange 24 Support pipe section 25 Through hole 26 Nozzle section 27 Flange 28 Inlet section 29 Connection opposite interface 30 Sealing surface 31 Rib 32 Outer surface 33 Sealing interface 34 Filter element 35 Filter medium 36 Front side 37 Front side 38 End plate 39 End plate 40 Opening 41 Positioning and sealing section 42 Sealing surface 43 Contact surface 44 Groove 45 Inner surface 46 Sealing interface 47 Positioning element 48 Recess 49 Secondary filter element 50 Rib 339 Notch 340 Areas of the positioning and sealing section 41,in which no notch 339 is arranged LFluid LR longitudinal direction RRadial direction LR in side RO raw side α Inclination angle,

Claims

1. A filter system (1A, 1B, 1C) having a filter housing (2) including a fluid inlet (14) for introducing a fluid (L) into the filter housing (2), a fluid outlet (3) for discharging the fluid (L) from the filter housing (2), a filter element (34) removably accommodated in the filter housing (2), the filter element comprising a positioning and sealing section (41) for positioning and sealing the filter element (34) with respect to the filter housing (2), and elastically deformable snap-fit elements (17), by means of which the filter housing (2) and the fluid outlet (3) are positively connected to one another, wherein the positioning and sealing section (41) radially abuts on the snap-fit elements (17), wherein the snap-fit elements (17) are inclined at an angle of inclination (α) relative to a symmetry axis (7) of the filter system (1A), and wherein the positioning and sealing section (41) comprises a contact surface (43) pressed radially against the snap-fit elements (17) and also inclined at the angle of inclination (α) relative to the symmetry axis (7), wherein the fluid outlet (3) comprises a sealing interface (33) against which a corresponding sealing mating interface (46) of the positioning and sealing section (41) is radially compressed, and wherein the positioning and sealing section (41) is designed in the shape of an annular bead extending axially away from an open end disc (38) of the filter element (34) by moving away from the filter element (34), characterized in that the sealing mating surface (46) features a cylindrical sealing surface (42) and the contact surface (43), and wherein the sealing surface (42) is disposed on a radially inner side of the annular bead, and wherein the snap-fit elements (17) are provided on a housing lower part (4) of the filter housing (2), and wherein the snap-fit elements (17) engage positively with an engagement section (28) provided on the fluid outlet (3).

2. The filter system according to claim 1, wherein the positioning and sealing section (41) is pressed radially against the snap-fit elements (17).

3. The filter system according to one of the preceding claims, wherein the snap-fit elements (17) engage positively with an engagement section (28).

4. The filter system according to claim 3, wherein the snap-fit elements (17) feature a side facing the engagement section (28) and a side facing away from the engagement section (28), wherein the positioning and sealing section (41) abuts radially on the sides of the snap-fit elements (17) facing away from the engagement section (28).

5. The filter system according to one of the preceding claims, wherein the snap-fit elements (17) and an annular receiving flange (21) provided on the housing lower part (4) form a connection interface (22) of the housing lower part (4).

6. The filter system according to claim 5, wherein the engagement section (28) and a disc-shaped flange (27) provided on the fluid outlet (3) form a connection mating interface (29) of the fluid outlet (3), and wherein the connection interface (22) and the connection mating interface (29) interact such that the snap-fit elements (17) engage the engagement section (28) positively and the flange (27) is received in the receiving flange (21).

7. The filter system according to one of the preceding claims, wherein the fluid outlet (3) is pivotable relative to the housing lower part (4).

8. The filter system according to one of the preceding claims, wherein the fluid outlet (3) comprises a grid-shaped support tube section (24) extending into the filter element (34) and a nozzle section (26) in particular bent at 90° protruding from the filter housing (2).

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