Filter element, in particular for gas filtration

Abstract

A filter element comprises a filter medium body and, located in the peripheral region, a sealing element, which is undulated shape in two different axial directions.

Description

[0001] Filter element, especially for gas filtration

[0002] This patent application claims priority from German patent application No. DE 10 2023 132 245.1, filed with the German Patent and Trademark Office on November 20, 2023, the contents of which are hereby incorporated by reference.

[0003] Technical area

[0004] The invention relates to a filter element which is used in particular for gas filtration, for example for an air filter, wherein the filter element has a filter medium body on whose circumferential edge region a sealing element is arranged.

[0005] State of the art

[0006] DE 10 2017 222 591 A1 describes a plate filter element for an air conditioning system or for the combustion air of an internal combustion engine. The plate filter element comprises a filter body made of pleated filter material and a closed, circumferential seal attached to the filter body, which extends in a wave shape along two opposite longitudinal sides of the filter body. The wave shape allows the seal to be compressed or stretched, particularly during installation in a filter housing, thereby compensating for tolerances.

[0007] Disclosure of the invention

[0008] The invention is based on the object of designing a filter element with a filter medium body and a sealing element arranged in the edge region with simple design measures with high error tolerance in order to facilitate the installation of the filter element in a receiving filter housing.

[0009] This object is achieved according to the invention with the features of claim 1. The subclaims specify expedient further developments.

[0010] The filter element according to the invention is preferably used for gas filtration, for example for an air filter in the intake tract of an internal combustion engine or for filtering the air supplied to a vehicle interior. The filter element can also be used for liquid filtration if necessary. The filter element comprises a filter medium body through which the fluid to be filtered is passed and at which filtration takes place, and a sealing element arranged in the edge region, via which a flow-tight connection with the adjacent inner wall areas of the filter housing is created when the filter element is installed in a housing. In the installed position, the sealing element separates the clean or downstream side of the filter element from the dirty or upstream side in a flow-tight manner.

[0011] The sealing element advantageously extends circumferentially around the filter medium body and completely encloses it. In principle, however, it is sufficient for the sealing element to extend at least along one side, optionally along several sides, of the filter medium body without being circumferential. In the latter case, the sealing element extends over a partial length of the circumferential edge area on the filter medium body.

[0012] The sealing element is wave-shaped along a sealing section in two different axial directions of the filter medium body. The sealing element is thus wave-shaped in the relevant sealing section in a first axial direction on one of its outer sides and, in the same sealing section, is also wave-shaped in a second axial direction with a second outer side of the sealing element. The first and second outer sides of the sealing element, which are each wave-shaped, border one another. This double-wave-shaped design of the sealing element has the advantage that a wave shape exists in two different axial directions and, accordingly, improved tolerance compensation can be achieved in these two axial directions with the sealing element stretching or expanding during installation in a receiving filter housing.Due to the double-wave design of the sealing element, tolerance compensation is possible by compressing or stretching the sealing element in two different axial directions. The double-wave design refers to the same sealing section of the sealing element, which is wave-shaped in the two different axial directions.

[0013] In principle, it is sufficient for the wave-shaped sealing section to extend along only one side of the filter medium body. It may be expedient for the sealing element to be circumferential, in particular completely circumferential, but with only one side being wave-shaped, while the other sides of the sealing element are designed without a wave shape and are smoothly continuous. Furthermore, it is possible for the sealing element not to be completely circumferential, but to cover only one wave-shaped side of the filter medium body, or to extend only over two or more sides of the filter medium body without being circumferential, with only part of the sealing element being wave-shaped.Finally, it is also possible for the sealing element to extend over several sides of the filter medium body or to be completely circumferential and to be double-waved over its entire length or part of its length.

[0014] According to an advantageous embodiment, a wave-shaped outer side of the sealing element is radial to the flow direction of the filter medium body. The flow direction of the filter medium body can be referred to as the axial or main axial direction, wherein the radial outer side of the sealing element points radially outward with respect to the axial direction or flow direction and is thus directed away from the filter medium body. The radially inner side of the sealing element, with which the sealing element rests directly against the filter medium body, is preferably not wave-shaped, but rather straight. Thus, the sealing element has a thickness that varies in the radial direction in the wave shape when the longitudinal extent of the sealing element is viewed along the outer side of the filter medium body.

[0015] According to a further advantageous embodiment, the second wave-shaped outer side of the sealing element lies axially outward with respect to the flow or axial direction and directly borders on the radially outer, wave-shaped side of the sealing element. The axial wave shape is preferably located only on one axial outer side of the sealing element, whereas the opposite outer side is straight or has a straight surface. Alternatively, however, it is possible for both opposite axial outer sides of the sealing element to be wave-shaped. In the case of only one wave-shaped axial outer side, this preferably faces away from the nearest inflow or outflow surface of the filter medium body. Alternatively, it is also possible for the axial outer side of the sealing element to be wave-shaped which faces the nearest inflow or outflow side of the filter medium body.

[0016] According to a further advantageous embodiment, the filter medium body and the filter element are cuboid-shaped. The sealing element preferably extends along all four outer sides of the cuboid and is circumferentially formed, with the wave shape preferably extending only over a portion of the sealing element, for example, only along one of the four outer sides of the cuboid.

[0017] In principle, the double wave shape of the sealing element can also be used for filter elements and filter medium bodies with a non-cuboid shape, for example on the axial end face of a hollow cylindrical filter element.

[0018] According to yet another advantageous embodiment, the sealing element directly borders the upstream side or the downstream side of the filter medium body. It may also be expedient for the wave-shaped part of the sealing element to extend only over a partial axial height of the filter medium body. For example, two parallel sealing elements, which are arranged circumferentially on the filter medium body, can be arranged adjacent to the upstream side and adjacent to the downstream side of the filter medium body. It is sufficient for only one of the circumferential sealing elements to have a double-wave-shaped section, whereas the second sealing element is designed without any wave shape. Furthermore, it is also possible for both sealing elements to each have a double-wave-shaped section or for one sealing element to be double-wave-shaped and the second sealing element to be single-wave-shaped.

[0019] According to yet another advantageous embodiment, the sealing element is applied to the edge region of the filter medium body by casting.

[0020] The filter medium body is preferably designed as a pleated filter, with the pleats aligned such that the pleat side walls extend parallel to the flow direction. Brief description of the drawings

[0021] Further advantages and practical embodiments can be found in the further claims, the description of the figures, and the drawings. They show:

[0022] Fig. 1 shows a perspective view of a cuboid filter element for gas filtration, with a filter medium body and a partially double-wave-shaped sealing element on the outside of the filter medium body;

[0023] Fig. 2 the circumferential sealing element with the wave-shaped section in individual representation;

[0024] Fig. 3 the sealing element in side view;

[0025] Fig. 4 the sealing element in plan view;

[0026] Fig. 5 the filter element in side view;

[0027] Fig. 6 the filter element in plan view;

[0028] Fig. 7 shows a perspective view of a filter device with a two-part filter housing, consisting of a housing base body and a housing attachment body, for receiving a filter element with a circumferential, wave-shaped sealing element;

[0029] Fig. 8 shows the filter device with the housing base body and the housing attachment body as well as the filter element in an exploded view shown in perspective from above;

[0030] Fig. 9 the filter device in an exploded perspective view from below;

[0031] Fig. 10 the filter device in a vertical section;

[0032] Fig. 11 is an enlarged detail of Fig. 11;

[0033] Fig. 12 shows an embodiment variant of the filter device in an exploded view shown in perspective from above;

[0034] Fig. 13 shows the filter device from Fig. 12 in an exploded perspective view from below;

[0035] Fig. 14 shows a further embodiment of the filter device in an exploded view shown in perspective from above;

[0036] Fig. 15 shows the filter device from Fig. 14 in an exploded perspective view from below;

[0037] Fig. 16 shows a further embodiment of the filter device in an exploded perspective view from above; and Fig. 17 shows the filter device from Fig. 16 in an exploded perspective view from below.

[0038] In the figures, identical components are provided with identical reference symbols.

[0039] Embodiment(s) of the invention

[0040] The filter element 1 shown in the figures is cuboid-shaped and comprises a filter medium body 2, which is designed as a pleated filter, and two circumferential sealing elements 3, 4, which extend along the outside of the filter medium body 2 and are connected to the filter medium body 2. The flow direction through the filter medium body 2 is indicated by the arrow 5. The side of the filter medium body 2 located at the bottom in Fig. 1 forms the inflow or raw side, while the side located at the top forms the outflow or clean side. The filter folds of the filter medium body 2 are aligned such that the fold side walls are parallel to the flow direction 5.

[0041] The sealing elements 3, 4 are applied to the edge region of the filter medium body 2 using a casting process. Both sealing elements 3, 4, which run parallel to one another, are arranged circumferentially on the filter medium body 2. The first sealing element 3 is located directly adjacent to the downstream side, and the second sealing element 4 is located directly adjacent to the upstream side of the filter medium body 2. Both sealing elements 3, 4 project radially—relative to the flow direction 5—over the circumferential outer side of the filter medium body 2.

[0042] One side of the rectangular, frame-shaped sealing element 3, which is arranged adjacent to the downstream side of the filter medium body 2, has a double wave-shaped design, whereas the three other sides of this sealing element 3 are straight and without a wave shape. The double wave-shaped section 3a of the sealing element 3 allows compression and expansion of the sealing element in two axial directions, thereby providing improved tolerance compensation, particularly when installing the filter element 1 in a receiving filter housing. The sealing element section 3a has a wave shape in the radial direction, relative to the flow direction 5. Accordingly, the radial distance, for example, from the outside of the filter medium body 2 to the radial outside of the wave-shaped sealing element section 3a is variable along the length of this section.The wave shape is applied only to the radial outer side of the sealing element section 3a, but not to the radially inner side, with which the sealing element 3 directly rests against the filter medium body 2. The wave troughs of the radial wave shape are located radially at the same height as the outer sides of the remaining, non-wave-shaped sections of the sealing element 3.

[0043] The second wave shape of the sealing element section 3a extends in the axial direction, also relative to the flow direction 5. As can be seen, for example, from Fig. 3 and Fig. 5, the axially lower side of the section 3a, which faces away from the downstream side of the filter medium body 2, is provided with a wave shape, whereas the upper side of the section 3a, facing the downstream side, is straight.

[0044] The extension between the trough and the crest of the radial waveform ranges between 10% and 50% of the maximum radial thickness of section 3a. The axial extension between the trough and the crest also ranges between 10% and 50% of the maximum axial extension of section 3a. The number of waves in the axial direction is only half the number of waves in the radial direction.

[0045] 7 to 11 show a filter device 6 with a two-part filter housing 7, consisting of a housing base body 8 and a housing attachment body 9, for receiving a filter element 1. Both the housing base body 8 and the housing attachment body 9 each have a circumferential, undulating, groove-shaped section 8a or 9a, which is adapted to the contour of the undulating, circumferential sealing element 3 on the filter medium body 2. The filter element 1 with the filter medium body 2 is cuboid-shaped as in the first exemplary embodiment, but only one circumferential sealing element 3 is provided, which, however, has a double undulation over its entire circumference. The circumferential, undulating sections 8a and 9a on the housing base body 8 and on the housing attachment body 9 are adapted to the undulation of the sealing element 3 and each rise above the outside of the housing base body 8 and the housing attachment body 9.This design enables the filter medium body 2 to be inserted into the housing base body 8 and the circumferential sealing element 3 to be positively suspended in the corrugated section 8a on the housing base body 8. When the housing attachment body 9 is placed on the housing base body 8, the corrugated section 9a of the housing attachment body 9 engages over the corrugated section 8a on the housing base body 8, including the inserted corrugated sealing element 3. The filter element 1 is then securely received in the filter housing 7 and lies in a flow-tight manner in the filter housing 7, such that the fluid to be cleaned is forced to take the path through the filter element 1 and incorrect flows are prevented. Flow nozzles 10, 11 are formed on the housing base body 8 and the housing attachment body 9, through which the raw fluid is introduced and the cleaned fluid is discharged.

[0046] The wave-shaped section 8a on the housing base body 8, analogous to the wave-shaped sealing element 3, has a wave shape in two directions orthogonal to the circumferential extension of the sealing element 3. Accordingly, a positive fit of the sealing element 3 in the wave-shaped section 8a on the housing base body 8 is provided in two mutually orthogonal directions.

[0047] The further exemplary embodiments according to Figs. 12 to 17 also show filter devices 6 with a two-part filter housing 7 with a housing base body 8 and a housing attachment body 9 and with an inserted filter element 1. Regarding the same components, reference is made to the description of Figs. 7 to 11.

[0048] According to Figs. 12 and 13, the wave-shaped section 8a on the housing base body 8 is provided with a substantially smooth outer wall. On the inside, the wave-shaped section 8a has cam-shaped protrusions 12 that correspond to radial wave troughs on the wave-shaped sealing element 3. When the filter element 1 is inserted, the cam-shaped protrusions on the inside of the wave-shaped section 8a engage with the wave troughs on the wave-shaped sealing element 3.

[0049] In Figs. 14 and 15, the wave-shaped section 8a on the housing base body 8 is designed as in the embodiment according to Figs. 8 and 9. The wave-shaped section 9a on the housing attachment body 9 additionally has recesses 13 on the upper axial edge, via which the connection to the side wall of the housing attachment body 9 is established, into which the sealing material of the sealing element 3 can spread when placed on the housing base body 8.

[0050] In Figs. 16 and 17, the wave-shaped section 8a on the housing base body 8, the wave-shaped section 9a on the housing attachment body 9, and the wave-shaped sealing element 3 are each provided with a smooth-walled section 14 on both opposite longitudinal sides in an otherwise wave-shaped configuration. The smooth-walled section 14 provides a clear installation position when assembling the housing base body 8, filter element 1, and housing attachment body 9.

Claims

Claims 1. Filter element, in particular for gas filtration, for example for an air filter, with a filter medium body (2), on the circumferential edge region of which a sealing element (3) is arranged, which extends at least over a partial length of the circumferential edge region, characterized in that the sealing element (3) is designed to be undulating in two different axial directions of the filter medium body (2), such that in a first axial direction a first outer side of the sealing element (3) is designed to be undulating and in a second axial direction a second outer side of the sealing element (3) is designed to be undulating, wherein the first and the second, in each case undulating outer sides of the sealing element (3) adjoin one another.

2. Filter element according to claim 1, wherein a wave-shaped outer side of the sealing element is radial to the flow direction (5) of the filter medium body (2).

3. Filter element according to claim 1 or 2, wherein a wave-shaped outer side of the sealing element (3) is located axially outward with respect to the flow direction (5).

4. Filter element according to claim 3, wherein only an upper or only a lower axial outer side of the sealing element is wave-shaped, whereas the opposite outer side of the sealing element is straight.

5. Filter element according to one of claims 1 to 4, wherein the filter medium body (2) and the filter element (1) are cuboid-shaped.

6. Filter element according to one of claims 1 to 5, wherein the wave-shaped part of the sealing element (4) extends only over a partial length of the circumferential edge region.

7. Filter element according to claim 6, wherein the wave-shaped part (3a) of the sealing element in the case of a cuboid-shaped filter medium body (2) extends only over a side of the edge area.

8. Filter element according to claim 6 or 7, wherein the sealing element (4) is arranged circumferentially on the filter medium body (2), wherein a non-wave-shaped part of the sealing element (4) adjoins the wave-shaped part (3a) of the sealing element (4).

9. Filter element according to one of claims 1 to 5, wherein the wave-shaped part of the sealing element (4) extends over the entire circumferential edge region.

10. Filter element according to one of claims 1 to 9, wherein the sealing element (4) is applied to the edge region of the filter medium body (2) by a casting process.

11. Filter element according to one of claims 1 to 10, wherein the wave-shaped part (3a) of the sealing element (4) extends only over an axial partial height of the filter medium body (2).

12. Filter device with a filter element (1) according to one of claims 1 to 11 and with a filter housing (7) for receiving the filter element (1).

13. Filter device according to claim 12, wherein the filter housing (7) has a wave-shaped, complementarily shaped and at least partially peripherally circumferential, groove-shaped section (8a, 9a) for receiving the wave-shaped outer side of the sealing element (3).

14. Filter device according to claim 13, wherein the filter housing comprises a housing base body (8) and a housing attachment body (9) which can be placed on the housing base body (8), wherein both the housing base body (8) and the housing attachment body (9) are each provided with a wave-shaped, groove-shaped section (8a, 9a).

15. Filter device according to claim 14, wherein the wave-shaped, groove-shaped section (9a) of the housing attachment body (9) can be inserted into the wave-shaped, groove-shaped section (8a) of the housing base body (8).

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