Round Filter Element

Abstract

A round filter element has an annular circumferentially extending pleated filter medium body to be flowed through by a fluid to be purified radially relative to a longitudinal axis of the filter medium body. A first end disk is arranged at a first end face of the filter medium body. A second end disk is arranged at a second end face of the filter medium body. The second end face is axially opposite the first end face. An outer or an inner contour of the first end disk is identically or at least substantially identically embodied to an outer or an inner contour of the filter medium body. An outer or an inner contour of the second end disk is identically or at least substantially identically embodied to the outer or the inner contour of the filter medium body. One of the first and second end disks is open.

Claims

1. An annular filter element, comprising: an annular filter medium body of a filter medium surrounding a longitudinal axis (L), the annular filter medium body comprising: a first axial end face; a first end disk arranged on the first axial end face of the annular filter medium body; a second axial end face arranged axially opposite to the first axial end face of the annular filter medium body; a second end disk arranged on the second axial end face; a plurality of circumferentially spaced folds formed into the filter medium, forming a plurality of pleats extending from the first axial end face to the second axial end face; wherein at least a respective one of the end disks is identically embodied or at least substantially identically embodied to a radially outer or radially inner contour of the plurality of plurality of pleats, so as to form a plurality of radially extending tooth projections in the at least a respective end disk, forming substantially a shape of a toothed gear.

2. The annular filter element according to claim 1, wherein the first end disk is a closed end disk, closing over a radial interior of the annular filter medium body.

3. The annular filter element according to claim 2, wherein the first end disk is identically embodied or at least substantially identically to the radially outer contour of the plurality of pleats, so as to form a plurality of radially outwardly extending tooth projections in the at least the first end disk.

4. The annular filter element according to claim 1, wherein the second end disk is an open end disk having a central opening that opens into a radial interior of the annular filter medium body, wherein the second end disk is identically embodied or at least substantially identically to a radially inner contour of the plurality of plurality of pleats, so as to form a plurality of radially inward projecting tooth projections in the at least a respective end disk.

5. The annular filter element according to claim 1, wherein at least a one of the end disks is injection molded directly onto a respective one of the axial end faces of the filter medium body.

6. The annular filter element according to claim 1, wherein pleat tips of the plurality of pleats of the annular filter medium body taper axially inwardly towards the longitudinal axis (L), forming a cone-shaped annular filter medium body.

7. The annular filter element according to claim 4, wherein the second end disk having the central opening is arranged on the respective axial end face of the annular filter medium body having a larger radial diameter.

8. The annular filter element according to claim 4, wherein a circumferentially extending seal ring of an elastomeric material is arranged on a radially outer side of the second end disk.

9. The annular filter element according to claim 5, wherein annular filter medium body has at least one circumferentially extending axially compressed section of the filter medium arranged adjacent to and spaced axially away from a nearest axial end face of the annular filter medium body, forming an uncompressed free region of the filter medium between the axially compressed section and the nearest axial end face of the annular filter medium body.

10. The annular filter element according to claim 9, wherein the axially compressed section forms a barrier separating plastic material of the end disk nearest the axially compressed section away from the uncompressed free region of the filter medium, the barrier forming a stop barrier of the injection molded plastic material.

11. A method for producing the annular filter element according to claim 10, the method comprising the steps of: forming the plurality of pleats into the filter medium; wrapping the filter medium about the longitudinal axis (L), to form the annular filter medium body; wherein the method further comprises: forming the axially compressed section by axially compressing the filter medium so as to form the axially compressed section spaced away from the nearest axial end face of the annular filter medium body, such that the annular filter medium body has the uncompressed free region of the filter medium arranged between the axially compressed section and the nearest axial end face of the annular filter medium body; providing a flowable plastic material; injection molding the flowable plastic material onto opposing axial end faces of the annular filter medium body forming the end disks; wherein the injection molding step further comprises the step of: forming a plurality of radially extending tooth projections onto a radially inner side or radially outer side of the end disk, forming substantially a shape of a toothed gear; wherein the radially extending tooth projections substantially follow a radially outer or radially inner contour of the plurality of plurality of pleats, forming a plurality of radially extending tooth projections.

12. The method for producing the annular filter element according to claim 11, wherein the step of forming the axially compressed section further comprises the step of: arranging the axially compressed section at distance of at least 5 mm away from the nearest axial end face of the annular filter medium body.

13. The method for producing the annular filter element according to claim 11, wherein the step of injection molding is practiced either by: immersing the uncompressed free region of the annular filter medium body into the flowable plastic material, or injection molding the flowable plastic material onto the uncompressed free region of the annular filter medium body.

14. The method for producing the annular filter element according to claim 11, wherein the step of injection molding is practiced either by: immersing the uncompressed free region of the annular filter medium body into the flowable plastic material, or injection molding the flowable plastic material onto the uncompressed free region of the annular filter medium body.

15. The method for producing the annular filter element according to claim 12, wherein the step of wrapping the filter medium further comprises the step of: forming the annular pleated filter medium body to have an outer diameter that tapers axially inwardly towards the longitudinal axis (L), forming the cone-shaped annular filter medium body.

16. The method for producing the annular filter element according to claim 13, wherein in the step of forming the annular pleated filter medium body, wrapping the filter medium such that the first axial end face has the smaller outer diameter than the opposite second axial end face such that the annular pleated filter medium body has an outer diameter that changes conically from the first axial end face to the opposite second axial end face at a cone angle of maximally 30 degrees.

17. The method for producing the annular filter element according to claim 11 wherein the injection molding step includes: molding the first end disk to be identically embodied or at least substantially identically to the radially outer contour of the plurality of plurality of pleats, so as to form a plurality of radially outwardly extending tooth projections in the at least the first end disk conforming to the radially outer contour of the plurality of pleats.

18. The method for producing the annular filter element according to claim 11 wherein the injection molding step includes: molding the second end disk as an open end disk having a central opening that opens into a radial interior of the annular filter medium body; the molding step includes the step of forming the plurality of radially inward projecting tooth projections conforming to a radially inner contour of the plurality of plurality of pleats.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Further advantages and expedient embodiments can be taken from the additional claims, the figure description and the drawings.

[0042] FIG. 1 shows a perspective view of a filter device with a round filter element that comprises a conical pleated-type filter medium body with end disks applied to the end faces.

[0043] FIG. 2 shows a perspective view of the open end face of the round filter element.

[0044] FIG. 3 shows the round filter element in half section view.

[0045] FIG. 4 shows an enlarged detail view of the open end disk at the filter medium body.

[0046] FIG. 5 shows the round filter element in plain view with closed end disk.

[0047] FIG. 6 shows the round filter element in a view from below with the open end disk.

[0048] In the Figures, same components are provided with same reference characters.

DESCRIPTION OF PREFERRED EMBODIMENTS

[0049] In FIG. 1, a filter device 1 is illustrated that can be used for gas filtration, for example, for an air filter for filtration of the combustion air of an internal combustion engine. The filter device 1 comprises a filter housing 2 and a round filter element 3 arranged in the filter housing 2 that, in relation to its longitudinal axis 4, is flowed through by the fluid to be purified in radial direction from the exterior to the interior. The fluid is introduced in the unpurified state via the fluid inlet 5 into the filter housing 2 and discharged in the purified state from the filter housing 2 through a fluid outlet 6. The outer side of the round filter element 3 forms the raw side, the inner side of the round filter element 3 forms the clean side that surrounds a preferably cylindrical interior inside the round filter element 3. From the interior in the round filter element 3, the purified fluid can be discharged axially through the fluid outlet 6 from the round filter element 3 and the filter device 1.

[0050] As can be seen in FIG. 1 in connection with the additional Figures, the round filter element 3 comprises a filter medium body 7 and end disk 8 and 9 at the oppositely positioned end faces of the filter medium body 7. The filter medium body 7 is embodied as an annular circumferentially extending body in cone shape and comprises a plurality of filter pleats whose filter edges form pleat tips (7A, 7B) extending at the cone angle of the cone shape in relation to the longitudinal axis 4 of the filter medium body 7. The cone angle amounts to 15? to 20? in the embodiment. The filter pleats of the filter medium body 7 are formed across the axial length of the filter medium body in a steady shape so that the pleat heightviewed in the radial direction-along the axial height of the filter medium body 7 remains the same. The filter pleats increase in a significant manner the filter surface of the filter medium body 7. The filter medium body 7 is comprised, for example, of a nonwoven material.

[0051] The end disk 8 at the narrower end face of the filter medium body 7 is of a closed configuration while the end disk 9 at the wider end face of the filter medium body 7 is of an open configuration. The end disks 8 and 9 are comprised of a plastic material that, for manufacturing, is introduced in liquid or at least flowable state into a casting mold part into which the respective end face region of the filter medium body 7 is immersed. In this context, two casting mold parts interact of which the lower casting mold part is provided with a cutout for receiving the end disk material. During manufacture, first the filter medium body continuous manner so that the fold is placed onto the lower casting mold part without end disk material, subsequently a second casting mold part is placed from above onto the filter medium body and the lower casting mold part, wherein one casting mold part is positioned inside the filter medium body and the second casting mold part outside of the filter medium body. The casting mold parts interact such with each other in such a way that the material of the filter medium body adjacent to the end face, but with a minimal spacing to the end face, is compressed.

[0052] After introducing the liquid or at least flowable end disk material into the correlated cutout in the lower casting mold part, the uncompressed section of the filter medium body 7 adjoining immediately the end face is immersed in the end disk material that can penetrate into the filter medium body material so that, after curing of the end disk material, a fixed connection between the end disk and the filter medium body is provided. At the same time, the compressed material of the filter medium body prevents undesirable spreading of end disk material into the filter medium body. This procedure can be carried out at both end faces of the filter medium body in order to respectively attach an end disk to the filter medium body.

[0053] The closed end disk 8 at the narrower side of the cone-shaped filter medium body 7 has a plurality of radially extending tooth projections 8A such the closed end disk 8 corresponds to the outer contour of the filter medium body 7 at the narrow end face. Thus, no end disk material of the end disk 8 projects past the outer contour of the filter medium body 7 at its raw side. The compressed section 10 of the filter medium body 7 adjoins immediately the closed end disk 8. The compressed section 10 extends axially past a length which is only slightly larger than the axial thickness of the end disk 8.

[0054] The oppositely positioned end face of the filter medium body 7 is covered by the open end disk 9 which comprises a large central cutout through which the purified fluid can axially flow out of the interior of the filter medium body 7. Accordingly, the open end disk 9 is of an annular shape. The outer contour of the open ring-shaped end disk 9 forms a circular ring and projects slightly past the outer contour of the filter medium body 7 at its wider end face. The inner contour of the open end disk 9 has a plurality of radially inwardly extending tooth projections 9A such that the open end disk 9 is matched to the inner contour of the filter medium body 7 at its wider end face. In this way, it is achieved, on the one hand, that the end faces of the filter pleats of the filter medium body 7 are covered flow-tightly by the end disk at the open end face. On the other hand, a maximum free flow area at the open end face of the filter medium body 7 is provided so that the purified fluid can flow axially out of the interior of the filter medium body 7 without any obstacles.

[0055] The open end disk 9 is located at the wider end face of the filter medium body 7 and frames the filter medium body 7 in the end face section. A compressed section 12 adjoins here axially which ensures that in the manufacturing process of the round filter element 3 no liquid or flowable end disk material can spread into the compressed section 12 of the filter medium body 7.

[0056] At the outwardly positioned side face of the open end disk 9, a circumferentially extending sealing ring is arranged; the sealing ring position 11 is illustrated in FIG. 4. The sealing ring at the sealing ring position 11 ensures flow-tight separation of the clean side from the raw side of the filter element 3. In the installed state, the round filter element 3 is supported with the sealing ring loaded in axial direction at the sealing ring position 11 at a housing-associated component of the filter housing.