Air filter system, air filter element and method for exchanging an air filter element

Abstract

A filter (1) for filtering air, in particular an air filtering element (30), is provided for releasably fitting into a housing (10) which has a housing upper part (11) and in particular a central tube (20) fastened to the housing upper part (11), and also the housing for the filtering element (30) is provided. The filtering element has a seal (33, 34) for holding the filtering element (1) on the housing upper part (11) and the central tube (20) and for sealing the space (111) between the filtering element (30) and housing upper part (11) when the filtering element (30) is releasably fitted in the housing (10). The seal (33, 34) is connectable in a form-fitting manner to a sealing receptacle (111) of the housing upper part (11) and/or of the central tube (20).

Claims

1. An air filter system comprising: an air filter element including a filter media; an annular seal having a contact zone configured to form a friction grip to hold the filter element, the annular seal arranged on an axial end of the filter media including: a radially extending cross beam arranged directly on the axial end of the filter media; an axially outwardly extending elastic sealing web or foot formed on an axially outer side of the cross beam and extending axially outwardly away from the axial end of the filter media and cross beam; and a flat cylindrical sealing surface formed on a radially inner or outer side of the axially outwardly extending elastic sealing web or foot and spaced axially outwardly away from the radially extending cross beam; wherein the sealing surface of the annular seal is arranged axially outwardly away from the radially extending cross beam; a housing including a housing upper part; a clean air connection for discharging clean air from the housing; a sealing receptacle sealably engaging against and mounting the radial acting seal of the filter element in a form-fitting tight-fit connection, the sealing receptacle spaced away from the radially extending cross beam of the annular seal, the sealing receptacle formed on an interior wall of the housing; wherein the form-fitting connection mountably holds the air filter element to the housing; wherein the housing upper part includes the sealing receptacle having a cylindrical extending sealing surface extending from the upper housing part; wherein the cylindrical extending sealing surface encloses the clean air connection; wherein the cylindrical extending sealing surface receives the sealing surface of the annular seal of the air filter element; an annular projection arranged in the housing and protruding radially over the sealing surface of the sealing receptacle and arranged on and at the sealing surface of the sealing receptacle, the annular projection enclosed by the radial acting seal of the air filter element in a form-fitting manner; wherein the form-fitting tight-fit connection is provided by the radial projection engaging radially against and pressing radially into the contact zone, elastically compressing the annular seal to radially compress annular seal to form a friction grip by forming a radial groove into the annular seal when the filter element is installed in the housing, providing the form-fitting tight-fit connection mountably holding the air filter element to the housing, wherein the cylindrical extending sealing surface of the sealing receptacle is spaced axially away from the radially extending groove formed into the annular seal.

2. The air filter system according to claim 1, wherein a through-flowable central tube is disposed in the housing coaxial to and as a continuation of the clean air connection, the through-flowable central tube supporting the air filter element; wherein the central tube is either detachably installable into the housing or made unitary in one piece with the housing upper part of the housing.

3. The air filter system according to claim 1, further comprising an axially extending central tube, the central tube having openings for radial flow through a circumferential wall of the central tube, the central tube having an annular collar extending radially outwardly from the central tube, a radial outer side of the annular collar forming the annular projection which forms the radial groove into the annular seal when the filter element when the filter element is in an installed state; wherein the annular projection is arranged at an axially inner end of a radially inner wall of the sealing receptacle and protrudes radially outwardly over the axially inner end of the radially inner wall of the sealing receptacle; wherein the central tube collar is firmly connected with the central tube, made in one piece of the same material with the central tube or abutting against the sealing surface.

4. The air filter system according to claim 1, wherein the sealing surface is formed radially outside or inside at a cylindrical collar projecting from the housing upper part into the interior space of the housing.

5. The air filter system according to claim 1, wherein the sealing receptacle is formed into and by the upper housing part by an annular recess or groove in the housing radially surrounding the clean air connection; wherein the sealing receptacle formed by the housing has a radially outer wall and a radially inner wall defining a U-shaped sealing receptacle into which the axially outwardly extending sealing web or foot of the filter element is received and radially sealed to the housing.

6. The air filter system according to claim 5, wherein the sealing surface is formed by the radially inner or radially outer wall of the recess or groove; wherein the sealing surface of the radially inner or radially outer wall of the recess or groove is cylindrical.

7. The air filter system according to claim 1, wherein the central tube is designed in such a way that a seal of the air filter element at the central tube is detachably attached by interlocking engagement or that the central tube is detachably attached by interlocking engagement at the housing upper part.

8. The air filter system according to claim 1, wherein the annular projection forms a circumferentially closed ring; or wherein the annular projection is a ring that is interrupted regularly or irregularly around its' circumference.

9. The air filter system according to claim 2, wherein the air filter element is a main filter element; the air filter system further comprising a secondary filter element, which is disposed downstream of the main filter element in flow direction of the air; wherein the main filter element is arranged on and attached on the outside of the central tube; and wherein the secondary filter element is arranged within an interior of the central tube when the main air filter element and secondary air filter element are detachably installed in the housing.

10. The air filter system according to claim 9, wherein the main filter element wherein the annular seal securely holds the main filter element onto the housing upper part or at the central tube; wherein the annular seal seals a space arranged between the main element and housing upper part when the main filter element is detachably installed in the housing; and the secondary filter element includes a seal for securely holding the secondary filter element onto the housing upper part or at the central tube; wherein the secondary filter element seal seals a space arranged between the secondary element and the housing upper part when the secondary filter element is detachably installed in the housing.

11. A filter housing for receiving an air filter element, the filter housing comprising: a housing upper part; a clean air connection for discharging clean air from the housing; an annular sealing receptacle formed as an annular U-shaped groove formed into an interior wall of the filter housing, the annular groove opening in an axial direction, wherein the annular sealing receptacle includes a cylindrical extending sealing surface extending axially from the upper housing part; wherein the cylindrical extending sealing surface surrounds and encloses the clean air connection; wherein the cylindrical extending sealing surface is configured to receive an annular seal of the air filter element; a central tube is disposed in the filter housing as a continuation of the clean air connection, the central tube of the filter housing sized for being received into the air filter element during installation of the air filter element into the filter housing and to support the air filter element relative to the filter housing; wherein the central tube is detachably installed into the filter housing or made unitary in one piece with the filter housing; wherein the central tube has an annular collar extending radially outwardly from a radially outer side of the central tube, a radial outer side of the annular collar forming an annular projection which protrudes radially over the cylindrical extending sealing surface of the U-shaped groove formed into the interior wall of the filter housing; the annular projection and annular sealing receptacle configured to form a form-fitting tight-fit connection with the annular seal of the air filter element during installation of the air filter element in the filter housing, by radially compressing an annular region of the annular seal to form a annular groove into which the annular projection is received.

12. The filter housing according to claim 11, wherein the annular projection forms a circumferentially closed ring; or wherein the annular projection is a ring that is interrupted regularly or irregularly around its' circumference.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The accompanying Figures, where like reference numerals refer to identical or functionally similar elements throughout the separate views and which together with the detailed description below are incorporated in and form part of the specification, serve to further illustrate various embodiments and to explain various principles and advantages all in accordance with the present invention.

(2) Features of the present invention, which are believed to be novel, are set forth in the drawings and more particularly in the appended claims. The invention, together with the further objects and advantages thereof, may be best understood with reference to the following description, taken in conjunction with the accompanying drawings. The drawings show a form of the invention that is presently preferred; however, the invention is not limited to the precise arrangement shown in the drawings.

(3) FIG. 1 is a three-dimensional view of an air filter according to one of the first examples of an embodiment;

(4) FIG. 2 is a sectional view of the air filter in FIG. 1 into which a filter element is detachably installed according to the first example of an embodiment;

(5) FIG. 3 is a three-dimensional detailed view of the filter element according to the first example of an embodiment;

(6) FIG. 4 is a detailed view of the filter element according to a second example of an embodiment;

(7) FIG. 5 is a detailed view of a filter element according to a third example of an embodiment which is installed in the filter in FIG. 1;

(8) FIG. 6 is a three-dimensional view of a main filter element of the filter element according to a fourth example of an embodiment;

(9) FIG. 7 is a three-dimensional detailed view of the main filter element of the filter element in FIG. 6;

(10) FIG. 8 is a detailed view of an air filter system according to a fifth example of an embodiment; and

(11) FIG. 9 is a detailed view of an air filter system according to a sixth example of an embodiment.

(12) In the Figures, the same reference numerals denote identical or similar components, unless otherwise stated. Skilled artisans will appreciate that elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions of some of the elements in the figures may be exaggerated relative to other elements to help to improve understanding of embodiments of the present invention.

DETAILED DESCRIPTION

(13) In the following, the invention is described by means of a filter for the combustion air of an internal combustion engine such as, for example, a motor vehicle. Instead of filtering air, suitable filter elements can be designed, for example, for filtering another gaseous or liquid medium such as, for example, oil.

(14) As shown in FIG. 1, the filter 1 comprises according to the first example of an embodiment a housing with a housing upper part 11 which is connected with a housing lower part 13 via a housing casing 12. The housing 10 in FIG. 1 is also a tripartite housing 10. The housing lower part 13 is held by means of clamps 14 at the housing casing 12. At the housing upper part 11 is disposed a raw air connection 15 with which raw air, unfiltered air, can be supplied into the housing 10 in the flow direction shown by the vertical block arrow. At the housing upper part 11 is also disposed a clean air connection 16 with which clean air, air cleaned from impurities, can be discharged from the housing 10 in the flow direction shown by the white block arrow. At the housing casing 12 or the housing lower part 13 is disposed a discharge valve 17 with which particles, that were contained in the raw air, can be discharged from the housing 10. A cyclone filtration is, for example, disposed upstream. The housing 10 has several ribs 18 at the housing upper part 11, the housing casing 12 and the housing lower part 13 which are, for example, meant to stiffen the housing 10 or the housing upper part 11, the housing casing 12 or the housing lower part 13. To provide a clear overview, not all ribs 18 in FIG. 1 are provided with a reference numeral.

(15) FIG. 2 shows a section through the housing 10 when a filter element 30 for filtering air is installed therein. The filter element 30 comprises a main element 31 and a secondary element 32 which can be mounted in the housing 10 independent of each other. The main element 31 is meant to filter first predetermined impurities from the air such as, for example, coarse dust. The secondary element 32 is meant to filter second predetermined impurities from the air such as, for example, fine dust. The secondary element 32 is disposed downstream of the main element 31 in flow direction of the air, as can be seen by the block arrows in FIG. 1 and FIG. 2.

(16) A clamped bracket 19 of a clamp 14 can be recognized in FIG. 2 in order to connect the housing parts 12, 13 with each other. The housing 10 has furthermore a first central tube 20 at which the tubular main element 31 of the filter element 30 is disposed. The housing 10 has moreover a second central tube 21 at which the annular secondary element 32 of the filter element is disposed. The second central tube 21 has a grid-shaped pipe wall and is fluid-permeable. The first central tube 20 has also a grid-shaped pipe wall and is fluid-permeable, even if this cannot be clearly seen in FIG. 2. The first central tube is attached to the housing 10, more precisely to its housing upper part 11. This attachment of the first central tube 20 is realized by interlocking the first central tube 20 to the housing 10, more precisely to its housing upper part 11. The second central tube 21 can also be attached to the housing 10, more precisely to its housing upper part 11. The attachment of the central tubes 20, 21 as well as of the filter element 30 is described later in detail with regard to FIG. 3 to FIG. 5 which depict each in detail an area in FIG. 2 identified by an arrow A.

(17) FIG. 1 and FIG. 2 show the case in which the housing lower part 13 is attached to the housing casing 12 by means of clamps 14 and brackets 19. To install the filter element 30 or its main element 31 and/or its secondary element 32, the clamps 14 can be declamped from the housing casing 12 so that the housing lower part 13 can be removed from the housing casing 12. In this state, the filter element 30 or its main element 31 and/or its secondary element 32 can be pushed along the first central tube 20 and/or the second central tube 21 into the housing 10 opened from below. The housing lower part 13 can then be attached again to the housing casing 12 by means of the clamps 14.

(18) FIG. 3 shows the main element 31 disposed on the exterior side of the first central tube 20 as well as the secondary element 32 disposed on the interior side of the first central tube 20 and the second central tube 21. The main element 31 has an annular seal 33 with an approximately T-shaped cross section. The seal 33 can also be called main element seal 33. The seal 33 can seal the space between main element 31 and housing upper part 11. The seal realizes a radial form fit. The material used for the seal 33 is foam made of polyurethanes (PU) or PUR foam. The seal 33 is disposed at one end of the annular main element 31. More precisely, the seal 33 is disposed with the crossbeam 331 of the T-shaped seal at the end of the annular main element 31. The line which is vertical with respect to the crossbeam, in other words the foot 332, of the T projects into a recess 111 of the housing upper part 11. The foot 332 of the T forms a projection and can also be called sealing web 332 of the seal 33. Preferably, the seal 33 is attached to the main element 31, for example by gluing. The seal 33 has support surfaces for radially supporting the main element 31 at the housing upper part 11, wherein this means radial in the direction of the tube radius of the annular main element 31. Thus, a radial seal is realized by means of the seal 33. The recess 111 is one part of the space between main element 31 and housing upper part 11 which is to be sealed.

(19) The seal 33 itself may have a recess or undercut 333 into which projects one part of the first central tube 20, a central tube collar 201, or the recess may be formed into the seal 33 by compression of the seal 33 by the central tube collar 201 when installed. The central tube collar 201 is a projection of the central tube 20. The undercut 333 is disposed in FIG. 3 at the transition from foot 332 to crossbeam 331 of the seal 33. The undercut 333 of the seal 33 is adapted to the shape of one end of the central tube collar 201 facing away from the first central tube 20. The undercut 333 and the central tube collar 201 realize, therefore, a form fit. Moreover, the recess 111 of the housing upper part 11 is disposed in such a way that the end of the central tube collar 201 facing away from the first central tube 20 engages into the undercut 333 of the seal 33 when the main element 31 of the filter element 30 is installed in the housing 10 at the first central tube 20. As a result, the first central tube 20 and the seal 33 engage with each other. To be even more precise, the central tube collar 201 of the first central tube 20 and the undercut 333 of the seal 33 engage with each other. If during maintenance of the cabin filter 1 an old filter element 30 is dismounted from the housing 10 by loosening the interlocking between the first central tube 20 and undercut 333, a new filter element 30 can then be detachably installed. The engagement of the central tube collar 201 into the undercut 333 or its interlocking may be haptically perceived as a snapping sound by the maintenance staff, at least in some embodiments. As a result, the maintenance staff receives a feedback that the main element 31 of the filter element 30 is installed in the correct and therefore safe position in the housing 10.

(20) As can also be seen in FIG. 3, the central tube 20 has moreover at its central tube end 202 facing the housing upper part 11 a protrusion 203 which projects to the interior side of the first central tube 20 and to the exterior side of the first central tube 20. The exterior side of the first central tube 20 faces the seal 33. The interior side of the first central tube 20 faces the secondary element 32 and the second central tube 21. On the one hand, the protrusion 203 projects into a corresponding undercut 112 of the housing upper part 11 which exists in a housing upper part web 113 of the housing 10. On the other hand, the protrusion 203 projects into and may form a corresponding undercut 341 of a seal 34 of the secondary element 32. The shape of the protrusion 203 is adapted to the desired shape of the undercut 112. Thus, the protrusion 203 and the undercut 112 can realize a form fit when the first central tube 20 is installed in the housing 10, as shown in FIG. 3. The shape of the protrusion 203 is also adapted to the shape of the undercut 341. Thus, the protrusion 203 and the undercut 341 can also realize a form fit when the first central tube 20 is installed in the housing 10, as shown in FIG. 3. As a result, the first central tube 20 is interlocked with the housing upper part 11 as well as with the seal 34 of the secondary element 32. As described above, this interlocking is detachable.

(21) The seal 34 can seal the space between secondary element 32 and housing upper part 11. The seal 34 can also be called secondary element seal 34. Foam made of polyurethanes (PU) or PUR foam can be used as material for the seal 34, the same as for seal 33. The seal 34 is disposed at one end of the annular secondary element 31 and abuts a housing upper part projection 114 which is disposed on the interior side of the clean air connection 16. The housing upper part projection 114 forms an axial stop for the seal 34 or the secondary element 32 connected therewith, for example by gluing. Axial means in the direction of the tube axis of the annular secondary element 32.

(22) FIG. 4 shows a similar detailed view, as in FIG. 3, to explain a second example of an embodiment of the filter element 30. The filter 1 and the filter element 30 of the second example of an embodiment are largely identical with the filter 1 and the filter element 30 of the first example of an embodiment. Therefore, only the differences between the first and the second example of an embodiment are described in the following. For the rest, reference is made to the description of the first example of an embodiment.

(23) In contrast to the first example of an embodiment, the filter element of the second example of an embodiment has at least one stiffening ring 334 in the seal 33. As an example, FIG. 4 shows three stiffening rings 334 which are disposed side by side in the seal 33. The ring of the stiffening rings 334 in FIG. 4 is disposed essentially parallel in relation to the crossbeam 331 of the seal 33. The stiffening rings 334 can be made of a harder material than that of the seal 33 such as, for example, hard plastics or metal.

(24) Thanks to one or more stiffening rings, the seal 33 has a higher stiffness against bending.

(25) FIG. 5 shows a similar detailed view, as in FIG. 3, to explain a third example of an embodiment of the filter element 30. The filter 1 and the filter element 30 of the third example of an embodiment are largely identical with the cabin filter 1 and the filter element 30 of the first example of an embodiment. Therefore, only the differences between the first and the third example of an embodiment are described in the following. For the rest, reference is made to the description of the first example of an embodiment.

(26) In contrast to the first example of an embodiment, the seal 33 of the filter element 30 of the third example of an embodiment is a two-component seal. Moreover, the filter element of the third example of an embodiment has two foot prong projections 335 at the foot 332 or the sealing web 332 of the seal 33 at the side facing the first central tube 20 or the secondary element 32. Furthermore, at the foot 332 of the seal 33 is realized a duckfoot bend projection 336 on the side facing the first central tube 20 or the secondary element 32. The dimensions of the complete foot 332 are adapted to the recess 111 of the housing upper part 11, as shown in FIG. 5. As a result, the foot 332 of the third example of an embedment shown in FIG. 5 can also realize a form fit with the recess 111 of the housing upper part 11, even if the form fit is in this case not as distinctive as it is with the form fits of the first and second examples of an embodiment. The foot 332 can interlock with the recess 111 of the housing upper part 11 which causes a haptic perception when installing the filter element 30 in the housing 10.

(27) FIG. 6 shows a main element 31 of the filter element 30 according to a fourth example of an embodiment in a three-dimensional overall view. The filter 1 and the filter element 30 of the fourth example of an embedment are largely identical with the filter 1 and the filter element 30 of the first, second or third example of an embodiment. Therefore, only the differences between the fourth and the other examples of an embodiment are described in the following. For the rest, reference is made to the description of the first to the third example of an embodiment.

(28) The main element 31 in FIG. 6 is a hollow-cylindrical body which features at its external circumference several rings 312 which, for the sake of clarity, do not all have a reference numeral in FIG. 6. At the bottom in FIG. 6, the main element 31 is completed by a base ring 313. The seal 33 is disposed at the end of the main element 31 opposing the base ring 313. The seal 33 has an inside sealing line 337 on the interior side of the main element 31 and a sealing web exterior side 338 of the foot 332 or the sealing web 332. Up to this point, the main element 31 is not different from the main element 31 of the first, second or third example of an embodiment.

(29) In this example of an embodiment, however, the seal 33 has in contrast to the first, second or third example of an embodiment a plurality of notches 339 which, for the sake of clarity, do not all have a reference numeral in FIG. 6. The notches 339 are disposed side by side along the circumference of the sealing web 332. FIG. 7 shows the shape of the seal 33 with the notches 339 in enlarged detail.

(30) The sealing exterior side 338 of the seal 33 is meant to generate a contact pressure to the sealing surface when the main element 31 is being installed or installed in the housing 10. The notches 339 reduce the pressure or the mechanical resistance which can be perceived during the installation of the main element 31. Because of the notches 339, the seal 33 is in fact non-confined or sandwiched in the recess 111 of the housing upper part. Instead, the sealing web 332 of the seal 33 of the main element 31 can escape into the free spaces formed by the notches 339 or fill them by deforming. As a result, a sufficient sealing effect can, however, be realized by means of the seal 33. However, when mounting the main element 31, less mounting force has to be applied than without notches 339. The reason for this is that less material is to be compressed radially.

(31) In FIGS. 8 and 9 are shown further examples of an embodiment similar to the examples of an embodiment according to FIGS. 3 and 4. The embodiments according to FIGS. 8 and 9 are different from the examples of an embodiment according to FIGS. 3 and 4 insofar that the first central tube 20 is firmly and undetachably connected with the housing upper part 11. This can, for example, be realized by a one-piece design in plastic injection molding or by a welded joint. A radially inwardly extending bulge 203 each which protrudes to the interior side of the first central tube 20 is disposed at the central tube 20. The interior side of the first central tube 20 faces the secondary element 32 and the second central tube 21. The bulge 203 engages into a corresponding undercut 341 of a seal 34 of the secondary element 32 which is realized in the shown examples of an embodiment by an elastic deformation of the seal 34. However, the undercut 341 can also be provided as radial groove in the seal 34, as described above.

(32) The seal 34 can seal the space between secondary element 32 and housing upper part 11. The seal 34 can also be called secondary element seal 34. Foam made of polyurethanes (PU) or PUR foam can be used as material for the seal 34, the same as for seal 33. The seal 34 is disposed at one end of the annular secondary element 32 and abuts a housing upper part projection 114 which is disposed on the interior side of the clean air connection 16. The housing upper part projection 114 forms an axial stop for the seal 34 or the secondary element 32 connected therewith, for example by gluing. Axial means in the direction of the tube axis of the annular secondary element 32. Radially outside of the central tube 20 is disposed an annular web 350 with a circular cylindrical sealing surface 351 at the housing upper part 11 which features at its end extending into the interior space of the housing 10 a radially outwardly extending bulge 203 which engages into an undercut 333 of the seal 33. FIG. 8 shows two variants of the undercut, wherein the cross section of the smaller undercut corresponds to the cross section of the bulge 203 and thus tightly encloses the surface of the undercut 333 when the main filter element 31 is installed. The dashed representation of the variant of the undercut 333 features in inner surface which is spaced from the surface of the undercut 333 when the main filter element 31 is installed in such a way that a gap is formed between bulge 203 and undercut 333. In the variant shown in FIG. 9, the undercut 333 is formed by an elastic deformation of the seal 33 (dotted representation).

(33) All examples of an embodiment of the filter 1, the filter element 30 and the housing 10 described above can be used individually or in all possible combinations. In this connection, the following characteristics are conceivable.

(34) Other geometries and dimensions for the filter element 30 as those depicted and described can be chosen insofar as the conditions at the installation site of the filter element 30 have to be taken into account and a detachable, haptically perceivable installation of the filter element 30 in the housing 10 is possible.

(35) Instead of an undercut in the seals 33, 34, the seal 33 and/or the seal 34 can also feature a projection or a bulge which engages into an undercut of the housing upper part 11 or of the first central tube 20. However, the variant of the form fit described in the examples of an embodiment between the seals 33, 34 and housing 10 is preferred for stability reasons.

(36) Foil can also be used as material for the seal 33. Likewise, foil can also be used as material for the seal 34.

(37) The number of notches 339 at the seal 33 can be chosen as appropriate. Only one notch 339 can also be provided. As an alternative, more notches 339 than shown in FIG. 6 can also be provided.

(38) In the foregoing specification, specific embodiments of the present invention have been described. However, one of ordinary skill in the art appreciates that various modifications and changes can be made without departing from the scope of the present invention as set forth in the claims below. Accordingly, the specification and figures are to be regarded in an illustrative rather than a restrictive sense, and all such modifications are intended to be included within the scope of the present invention. The benefits, advantages, solutions to problems, and any element(s) that may cause any benefit, advantage, or solution to occur or become more pronounced are not to be construed as a critical, required, or essential features or elements of any or all the claims. The invention is defined solely by the appended claims including any amendments made during the pendency of this application and all equivalents of those claims as issued.