Liquid Filtering Device

Abstract

A filter arrangement for liquids has a filter housing and a functional carrier arranged inside the filter housing. A cylindrical filter element is inserted axially into the filter housing and defines an unfiltered side and a filtered side inside the filter housing. A non-return diaphragm is arranged on the filter element within the filter housing, wherein the non-return diaphragm is connected to the functional carrier and held at an axial spacing against a stop of filter housing so as to effect an axial and/or radial sealing action of the unfiltered side relative to the filtered side of the filter arrangement.

Claims

1. A filter element for liquids, comprising: a cylindrical filter element of zigzag folded filter media in a cylindrical shape around a central axis, the filter element having an open interior extending axially on the central axis, wherein the zig-zag folded filter media includes: a first axial end face; an opposing second axial end face; a radially inner flow face arranged at and circumferentially surrounding the open interior and the central axis, the radially inner flow face extending between the first and second axial end faces; and a radially outer flow face arranged at and circumferentially surrounding the radial outer side of the cylindrical shaped filter media and circumferentially surrounding the radially inner flow face, the radially outer flow face extending between the first and second axial end faces; wherein one of the inner and outer flow faces is an unfiltered flow face through which unfiltered liquid enters the filter element; wherein a different one of the inner and outer flow faces is an filtered flow face through which filtered liquid leaves the filter element; a first end plate that is substantially flat and circular, the first end plate lying directly on and closing directly against the zigzag folded filter media across the first axial end face from proximate to the radial inner flow face of the filter media to the radial outer flow face of the filter media, such that the first axial end face of the zigzag folded filter media is in direct contact with and fixed directly onto the first end plate; wherein a radially innermost edge of the first end plate is arranged on the first axial end face of the filter media of the cylindrical filter element and spaced radially outwardly away from a radial inner flow face of the filter media; wherein the first end plate is substantially flat and extending radially in a direction substantially perpendicular to the central axis, the first end plate having: a central opening extending axially through the first end plate and opening into the radially inner flow face at the open central interior of the filter element; an axial projection formed as an annular wall having a first axial end positioned on an outer circumference of the central opening and surrounding the central opening, the axial projection having an opposite second axial end arranged axially outwardly away from the first end plate and filter media; an annular non-return diaphragm comprised of an elastomer and coupled onto the axial projection, the annular non-return diaphragm arranged on the annular projection and extending on a radially inner surface and on a radially outer surface of the annular projection; wherein the annular non-return diaphragm on the radially inner surface of the annular projection forms a radial seal adapted to seal radially against a filter housing component when the filter housing component is received into the axial projection; wherein the axial projection has an axial length that is sized such that, when the filter element is installed in a filter housing, the second axial end is supported on an axial stop formed in an interior of the filter housing, an interaction of the axial projection resting against the axial stop applying a predetermined pretension to the annular non-return diaphragm where it sealably contacts against a sealing surface in an interior of the filter housing, such that the non-return diaphragm is elastically deflectable/flexible within predetermined limits in an axial direction of the filter element.

2. The filter element according to claim 1, wherein the non-return diaphragm forms at least one radially inwardly projecting bulge in the radial seal on the radially inner side of said annular wall of said axial projection, the at least one adially inwardly projecting bulge operable to seal radially against the filter housing component received into the axial projection.

3. The filter element according to claim 2, wherein non-return diaphragm has two radially inwardly projecting bulges in the radial seal, the bulges spaced apart axially on the radially inner side of said axially extending wall and separated by an annular groove.

4. The filter element according to claim 1, wherein a radially innermost edge of the first end plate is arranged on the first axial end face of the filter media of the cylindrical filter element and spaced radially inwardly away from a radial inner flow face of the filter media.

5. The filter element according to claim 1, wherein the annular non-return diaphragm is detachably coupled onto the axial projection.

6. The filter element according to claim 1, wherein the first end plate includes: a plurality of radial noses formed directly on a radially outer circumference of the first end plate and projecting radially outwardly away from the filter media, the plurality of radial noses angularly spaced apart on the outer circumference of the first end plate.

7. The filter element according to claim 1, further comprising: an annular rim formed on a radially outer circumference of the substantially flat first end plate, the annular rim having: a radially inner side arranged on the radially outer flow face of the filter media; and a radially outer side; wherein the annular rim projects axially from the first end plate in a direction towards the opposing second axial end face of the filter media.

8. A filter arrangement for filtering liquids, the filter arrangement comprising: a filter housing; a filter element according to claim 1 arranged within the filter housing; wherein the axial projection of the filter element has an axial length that is sized such that, when the filter element is installed in a filter housing, the axial projection is supported on an axial stop formed on an interior wall of the filter housing, an interaction of the axial projection resting against the axial stop applying a predetermined pretension to the annular non-return diaphragm where it sealably contacts against a sealing surface in an interior of the filter housing, such that the non-return diaphragm is elastically deflectable/flexible within predetermined limits in an axial direction of the filter element.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Embodiments of the filter arrangement according to the invention will be explained with the aid of the Figures. It is shown in:

[0022] FIG. 1 a section of a basic configuration of a filter arrangement for liquids according to the prior art;

[0023] FIG. 2a a schematic illustration of a filter element for a filter arrangement according to FIG. 1 with a non-return diaphragm and an axial sealing action of the unfiltered side in the liquid flow;

[0024] FIG. 2b a schematic illustration of a filter element for a filter arrangement according to FIG. 1 with a non-return diaphragm and a radial sealing action of the unfiltered side in the liquid flow;

[0025] FIG. 3a a detail illustration of a radially sealing non-return diaphragm with a two-component attachment on an end plate of the filter element;

[0026] FIG. 3b a detail view of an axially sealing non-return diaphragm with a two-component attachment on an end plate of the filter element;

[0027] FIG. 3c a detail illustration of a radially sealing non-return diaphragm that is coupled to an end plate of the filter element;

[0028] FIG. 3d a detail view of an axially sealing non-return diaphragm that is coupled to an end plate of the filter element;

[0029] FIG. 3e a detail illustration of another embodiment of an axially sealing non-return diaphragm that is connected to an end plate of the filter element;

[0030] FIG. 4 a schematic illustration of an axially sealing non-return diaphragm that is mounted on a two-part snapped-on central tube for a filter element;

[0031] FIG. 5 a schematic illustration of an axially sealing non-return diaphragm that is mounted on a single-part central tube for a filter element;

[0032] FIG. 6 a schematic illustration of a radially sealing non-return diaphragm that is mounted on a single-part central tube for a filter element;

[0033] FIG. 7 a further schematic illustration of a non-return diaphragm that is mounted on an extended central tube for a filter element;

[0034] FIGS. 8a to 8c further embodiments of attachments of the non-return diaphragm on the central tube according to FIG. 7;

[0035] FIG. 9 an embodiment of an end plate on the filter element that has a stop for generating a defined pretension for the non-return diaphragm;

[0036] FIG. 9a is a schematic illustration of an embodiment of FIG. 9 having the axial stop radial noses of FIGS. 11 and 11a, the radial noses extending radially outwardly from the end plate as shown in FIGS. 11 and 11a;

[0037] FIG. 10 an embodiment that has an end plate with a non-return diaphragm and can be attached to the filter element by means of a snap-on connection;

[0038] FIG. 11 a plan view of one embodiment of an end plate with radial noses;

[0039] FIG. 11 a is a schematic illustration of the end plate with the radial noses of FIG. 11 engaging a lateral recess of the housing.

DETAILED DESCRIPTION OF THE INVENTION

[0040] In FIG. 1 a filter arrangement is illustrated that, in principle, corresponds to a filter arrangement for fuel or lubricant for an internal combustion engine disclosed in the prior art reference DE 100 46 494 A1. The unfiltered liquid that is to be filtered flows through an inlet 1 into the filter housing that is comprised of a top part 2 and a bottom part 3. In the filter housing, a filter element 4 of zigzag-folded filter paper is arranged that is pushed onto a central tube 5 and is clamped fixedly upon joining the filter housing. The unfiltered liquid flows through the filter element 4 and exits at the filtered side through the central tube 5 and through the outlet 6.

[0041] A non-return diaphragm 7, for example, made of elastomer, is arranged on the end plate 8 of the filter element 4 and releases at the unfiltered side the liquid flow but upon interruption of the flow, for example, when the internal combustion engine is shut down, prevents return flow into the supply channel 1 as the diaphragm contacts axially or radially the filter housing. FIGS. 2a and 2b illustrate the principal mechanisms of the function of such non-return diaphragms 7; FIG. 2a shows an axial sealing action and FIG. 2b shows a radial sealing action.

[0042] FIGS. 3a to 3e show respectively different embodiments of the non-return diaphragm 7 mounted on an end plate 8. The FIGS. 3a and 3b show non-return diaphragms 7 that are glued, welded or connected by a two-component method, and FIGS. 3c to 3e show non-return diaphragms 7 coupled to the end plate 8.

[0043] FIG. 4 shows the attachment of the non-return diaphragm 7 on a two-part central tube 5, and FIG. 5 and FIG. 6 show, respectively, an attachment of the non-return diaphragm 7 on a single-part central tube 5.

[0044] FIG. 7 shows an embodiment in which the non-return diaphragm 7 is attached to the central tube 5 in such a way that a sealing bead 9 results with which a radial sealing action between the central tube 5 and the bottom housing part 3 (compare FIG. 1) can be realized. FIG. 8a shows the possibility of an axial sealing action with the sealing bead 9, and FIGS. 8b and 8c show further sealing actions as a supplement to the arrangement according to FIG. 7.

[0045] In FIG. 9, as a supplement to the illustrations of FIGS. 3a to 3e, it is shown that for an end plate 8 as a functional carrier, a non-return diaphragm 10 can be attached to the end plate 9 and in particular to a projection in the form of an annular axial projection 11 of the end plate 8. As taught in paragraph [0018], the non-return diaphragm 10 in all described embodiments can be connected fixedly to the functional carrier 8 (annular axial projection 11 of the end plate 8) by gluing, welding, or by means of a two-component method, or a detachable connection of the non-return diaphragm 10 with the axial projection 11 by coupling can be provided. In this way the non-return diaphragm 10 is detachable from the axial projection 11, and therefore not fixedly connected. A detachable connection of the non-return diaphragm 11 with the functional carrier by coupling can be provided, as illustrated by example of FIG. 3d, such that the non-return diaphragm 11 is detachably received on the axial projection 11. The non-return diaphragm 10 includes a radial seal operable to seal against a component received into the axial projection 11. The radial seal of the non-return diaphragm 10 may have a plurality of radially inwardly extending bulges 12 operable to seal against a component received into the axial projection. The axial projection 11 is sized with regard to its length such that by means of the axial projection 11 contacting the step 14 of the filter housing, an axial stop 14 is formed so that as a result of the remaining space (arrow 15) a predetermined pretension can be produced when the non-return diaphragm 10 contacts the sealing surface of the filter housing. As an alternate to the gluing, welding or detachable connection, the non-return diaphragm 10 may be embedded into the axial projection 11 by injection-molding.

[0046] FIG. 10 shows an alternative embodiment of an end plate 16 as a functional carrier having on the exterior so-called snap-on noses 17 so that the non-return diaphragm 10 with the end plate 16 can be connected by means of a snap connection to the filter element 4. Upon snapping on or upon axial sliding onto the end surface of the filter element 4, the snap-on noses 17 engage laterally the intermediate spaces of the folded filter webs of the filter element 4 above an axial glued connection 18 of the filter webs and provide a detachable connection in this way.

[0047] In this connection, it is also possible to provide by injection molding elastomer extensions on the non-return diaphragm 10 radially and/or axially between the end plate 16, 17 and the filter element 4 that, for providing a sealing action, are clamped during mounting.

[0048] An end plate 20 according to FIG. 11 is designed such that, as a modification to the end plate 16 according to FIG. 10, radial noses 21 are provided that engage into lateral recesses 30 FIG. 11a, of the filter housing 3, as is illustrated e.g. by means of the bottom part 3 according to FIGS. 2a and 2b. The recesses 30 are formed in the housing and have an axial stop 32 formed at axial end of the recesses 30. The axial stop 32 defines a final end position of axial movement of the filter element relative to the housing during installation in the housing such that, when contacted by the radial noses 21, a stop 32 is formed so that by means of the remaining space a predetermined pretension can be produced in the non-return diaphragm when the non-return diaphragm contacts the sealing surface of the filter housing.

[0049] FIG. 9a is a schematic illustration of the embodiments discussed with of FIG. 9 in which the end disk according to FIGS. 11 and 11 a is utilized. The radially outwardly extending radial noses 21 formed on the radial outer side of the end plate 16 as shown in FIGS. 11 and 11a. An end plate 8 (or 20) as a functional carrier a non-return diaphragm 10 can be attached to the end plate 20, 8 and in particular to a tubular axial projection in the form of an axial projection 11 of the end plate 20, 8. The end plate 20,8 is fixedly connected to and arranged on the zigzag folded filter media 4 on an axial end face 8 of the filter element, the end plate having a central opening (substantially where pin 13 extends through the end plate) extending axially through the end plate and opening into the open central interior of the filter element. The end plate 20, 8 is substantially flat and extending radially in a direction substantially perpendicular to the central axis. The end plate has an axial projection 11 circumferentially surrounding the central opening in the end plate and projecting axially away from the filter element. The axial projection may have radial openings (radial openings in 11) extending radially through an axially extending wall 11 of the axial projection 11 for embedding the non-return diaphragm onto radially inwardly through the radial openings of the axial projection. The end plate has a plurality of radially outwardly extending radial noses 21 arranged on an a radially outer circumference of the end plate and projecting radially outwardly away from the end disk 20,8. The radial noses may be angularly spaced apart radially on the outer circumference of the end plate, the radially outwardly extending noses operable to engage into recesses provided in an interior of a filter housing to provide an axial stop of the filter element so that as a result of the remaining space (arrow 15) a predetermined pretension can be produced when the non-return diaphragm 10 contacts the sealing surface of the filter housing. The housing may include a step 14 (as in FIG. 9). The axial projection 11 may be sized with regard to its length such that by means of it upon contacting the step 14 of the filter housing an axial stop is formed so that as a result of the remaining space (arrow 15) a predetermined pretension can be produced when the non-return diaphragm 10 contacts the sealing surface of the filter housing.

TECHNICAL UTILITY

[0050] The invention is, for example, usable in automotive technology, in particular in filter arrangements for liquids, in particular for oil or fuel.