Filter device

A filter device for gases may include a housing having a first housing and a second housing configured to axially abut each other in a flange regione. A plate-shaped filter element may have a circumferential seal arranged in the flange region. The first housing part may have two mutually opposite radial bearing faces in a flange region and the seal may have two radial sealing faces facing away from each other and each sealing face may bear flat against the respective bearing face.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to German Patent Application 10 2010 041 948.6 filed Oct. 4, 2010, and International Patent Application PCT/EP2011/066473 filed on Sep. 22, 2011, both of which are hereby incorporated by reference in their entirety.

TECHNICAL FIELD

The present invention relates to a filter device for gases, in particular air filter device, preferably for a fresh air system of an internal combustion engine, for example of a motor vehicle, according to the preamble of the claim.

BACKGROUND

WO 2009/150165 discloses a filter device for filtering gaseous fluids, which has a housing which has at least one first housing part and a second housing part which axially abut each other in a flange region. Furthermore, the filter device has a plate-shaped filter element, which is equipped with a circumferential seal, which engages in the flange region. A “plate-shaped” filter element or plate filter element extends substantially in a plane which extends transversely to the flow direction.

In the known filter device, the first housing part has in the flange region a radial bearing face which faces the housing interior, while the seal has in the flange region a radial sealing face which faces away from the housing interior and comes to bear radially in a sealing manner against the one bearing face of the first housing part when in the assembled state. Furthermore, the seal is supported radially on the second housing part on a side facing the housing interior.

DE 44 12 474 A1 discloses an air filter device in which a plate-shaped filter element with a circumferential seal engages in a flange region in which two housing parts border each other. The first housing part has in the flange region an axially open, circumferential receiving groove, into which the seal is axially inserted. The second housing part has an axially projecting, circumferential web, which is supported axially on an axial sealing face of the seal in the region of the receiving groove. In this air filter device, the two housing parts do not come to bear against each other directly, but only indirectly, namely via the seal.

A further filter device of this type is known from EP 1 647 701 B1.

SUMMARY

The present invention is concerned with the problem of specifying an improved embodiment for a filter device of the type mentioned in the introduction, which is comparatively easy to assemble and has an effective sealing effect.

This problem is solved according to the invention by the subject matter of the independent claim. Advantageous embodiments form the subject matter of the dependent claims.

The invention is based on the general concept, in a filter device in which the housing parts come to bear axially directly against each other in the flange region, of equipping the first housing with two mutually opposite radial bearing faces in the flange region and providing the seal with two radial sealing faces which face away from each other and bear flat against the bearing faces when in the assembled state. In this manner, two radially effective sealing zones which are radially spaced apart from each other are realised in the flange region. Because the two bearing faces are attached to the same housing part, the two sealing zones work in series, which increases the effectiveness of the achievable seal. Furthermore, the filter element can simple be mounted on the first housing part during assembly of the filter device in such a manner that the second housing part can be brought to bear axially against the first housing part without substantial axial assembly forces, in order fix the two housing parts in this relative position to each other. This achieves a significant simplification of the assembly process.

According to an advantageous embodiment, the first housing part can have an outer web, which runs around the flange region, projects axially and has the radially outer radial bearing face. The second housing part can then expediently have a supporting face which runs around the flange region and on which the outer web is axially supported. The two housing parts thus bear axially against each other via the supporting face and the outer web when in the assembled state. This ensures a defined relative position for the assembled state.

According to another advantageous embodiment, the seal can have a circumferential slot region which is axially open towards the second housing part radially between the sealing faces. This slot region gives the seal increased elasticity in the radial direction, as a result of which the two sealing faces can be compressed radially onto each other more easily, which makes it easier to introduce the seal into a receiving space formed on the first housing part between the two bearing faces.

According to an advantageous embodiment, a plurality of radial webs which are spaced apart from each other in the circumferential direction and by means of which radially opposite slot walls are supported radially on each other can be provided in the said slot region. With the aid of such radial webs, the seal can be stabilised again in the slot region, for example in order to increase the radial prestress forces with which the sealing faces come to bear radially against the bearing faces. Whereas the slot region in principle allows a radial adjustment of the sealing faces within the seal, the radial webs ensure that a sufficient radial prestress which counteracts such a radial compression is maintained.

According to another advantageous development, the radial webs can be formed integrally on the seal or integrally on the second housing part, in particular on the above-mentioned supporting face. It is likewise possible to form a plurality of radial webs integrally on the seal and a plurality of radial webs integrally on the second housing part, for example on the above-mentioned supporting face. The integration of the radial webs in the seal allows the radial webs to be produced particularly simply from the same material as the seal. However, it is in principle also possible to injection-mould the radial webs consisting of a different material to the seal with a two-component method. With the integral configuration of the radial webs on the housing part, a different material from that chosen for the seal can be chosen particularly simply for the radial webs. The radial webs can in particular have a higher rigidity than the seal as a result. It is thereby in particular possible owing to the slot region simply to mount the seal on the first housing part and to improve the sealing effect significantly by placing on the second housing part, the radial webs of the second housing part go into the slot region of the seal and the sealing faces produce forces which drive radially outwards in the seal. The radial webs on the housing side can then go in the circumferential direction, in each case between radial webs on the seal side, into the slot region.

Alternatively, it is likewise possible to form on the housing part, in particular on the above-mentioned supporting face, a web which runs in the circumferential direction and projects axially, the cross-sectional profile of which can taper, in particular with increasing distance from the housing part, and which is shaped and positioned in such a manner that it more or less goes into the slot region of the seal when the second housing part is mounted.

In another embodiment, the radial webs can be the same size or smaller than the slot region in the axial direction. Additionally or alternatively, the radial webs can have different sizes in the axial direction. Further, the radial webs can have outer sides which are spaced apart from each other in the circumferential direction and extend parallel to each other or obliquely to each other, it being possible for outer sides which are oblique in relation to each other to converge or diverge radially outwards. The above-described variants, which can be realised cumulatively or alternatively or in any combination, can in each case be used to set the elasticity of the seal in a targeted manner, in particular in the radial direction, in such a manner that particularly simple assembly is achieved with an adequate sealing effect.

According to another advantageous embodiment, the filter body can have a polygonal, in particular rectangular cross section in the axial direction. The above-mentioned slot region can have a radial recess in at least one corner region of the filter body, preferably in each corner region of the filter body, in particular on a radially outer slot wall. Such a recess allows the seal material, which is forced in the circumferential direction by the radial compression of the seal when the filter body is mounted on the first housing part, to be diverted into such a recess in the respective corner region. In particular the risk of fold formation and hardening within the respective sealing face can be avoided thereby. The respective recess is in this case not continuous in the radial direction, so it does not penetrate the seal. The radial depth of the respective recess is correspondingly smaller than a radial distance between the respective slot wall and the respective adjacent sealing face. Consequently, the sealing faces are designed to be interruption-free or continuous in the circumferential direction.

According to another advantageous embodiment, the first housing part can have a circumferential groove which is open towards the second housing part in the flange region, the mutually facing groove walls of which have or form the bearing faces. This groove then encloses the above-mentioned receiving space into which the seal can be axially inserted. The dimensions of this groove and the seal are preferably matched to each other in such a manner that an axial distance is present between the seal and a groove bottom situated between the groove walls. This means that the seal does not come up against a stop in the axial direction when used properly. This simplifies the mounting of the filter element on the first housing part.

It is advantageous if one of the housing parts has a protective collar which runs around the outside of the receiving space for the seal, at least in substantial regions. The protective collar preferably encircles the receiving space completely. The protective collar, which is formed, preferably integrally, with the housing part as an annular wall, prevents dirt from being able to penetrate directly to the seal when the filter device is in the assembled state. Furthermore, the protective collar prevents the sealing region from being damaged from outside by mechanical effects. To this end, the protective collar is preferably arranged on the housing part which receives the seal. The protective collar can be arranged at a distance from the receiving space, as a result of which a contour of the other housing part can engage, in particular contactlessly, in this spacing and thus form better protection for the seal or the sealing region.

According to another embodiment, the seal can have a circumferential axial sealing face radially between the radial sealing faces, which bears axially against a circumferential axial bearing face which is formed in the flange region on the second housing part. A third sealing zone is thereby formed on the seal, which zone interacts in an axially sealing manner with the second housing part.

It is particularly expedient if the filter device is operated or used in terms of its flow direction that a clean side is situated inside the first housing part, which clean side is separated by the filter element from an untreated side, which is situated inside the second housing part. Any leakages which occur can thus only take place on the untreated side, which is largely uncritical at least in a fresh air system of an internal combustion engine. However, an incorrect intake of air through the two sealing zones arranged in series between the seal and the first housing part is largely avoided.

In a specific embodiment, it can be provided for the axial bearing face to be arranged axially at the same height as the above-described axial supporting face on which the first housing part is axially supported on the second housing part.

According to another embodiment, the first housing part can have an inner web, which runs around the flange region, projects axially and has or forms the radially inner radial bearing face. In particular, the seal can then optionally have an axial sealing face which runs around the flange region and on which the inner web is axially supported. The sealing effect can thereby be additionally improved.

A radial spacing, which is penetrated by the seal, can expediently be present between the inner web and the second housing part. Additionally or alternatively, an axial spacing can be present between the axial sealing face which faces the inner web and an axial sealing face which faces the second housing part. Additionally or alternatively, the inner web can be shorter in the axial direction than an outer web of the first housing part. The above variants can be realised alternatively or cumulatively or in any combination. In particular, these features allow a specific geometric match between the housing parts and the seal to such an extent that the seal is positioned and supported in a dimensionally stable manner in the flange region. A comparatively high level of functional reliability can thereby be achieved for the seal.

The invention also relates to a filter element which is suitable for use in a filter device according to the invention. The filter element accordingly is characterised at least in that it is plate-shaped and has a circumferential seal, which has two radial sealing faces facing away from each other in the flange region.

The direction terms “axial” and “radial” refer to the assembly direction with which the filter element is mounted on the first housing part and in which the two housing parts are mounted on each other. This assembly direction then defines the axial direction, that is, the axial direction runs parallel to the assembly direction. Accordingly, the radial direction extends transversely to the assembly direction.

Further important features and advantages of the invention can be found in the subclaims, the drawings and the associated description of the figures using the drawings.

It is self-evident that the above-mentioned features and those still to be explained below can be used not only in the combination given in each case but also in other combinations or alone without departing from the scope of the present invention.

Preferred exemplary embodiments of the invention are shown in the drawings and are explained in more detail in the description below, the same reference symbols referring to the same or similar or functionally equivalent components.

DETAILED DESCRIPTION

According toFIG. 1, a filter device1comprises a housing2, which has at least one first housing part3and a second housing part4. The filter device1also comprises a filter element5which is arranged in the housing2. The filter arrangement1acts to filter gases, in particular air. The filter device1is thus preferably an air filter device. The air filter device1can for example be used in a fresh air system of an internal combustion engine which can be arranged in a motor vehicle.

The two housing parts3,4abut each other axially at an abutment point6in a flange region7. The housing parts3,4are also connected in a detachable manner to each other, which is not shown here. The axial direction is indicated inFIG. 1by a double arrow and referred to with8. The axial direction8runs parallel to an assembly direction9, which is likewise indicated by an arrow and in which the two housing parts3,4are attached to each other. A further double arrow10indicates a radial direction, which runs transversely to the axial direction8and correspondingly also transversely to the assembly direction9.

The filter element5is plate-shaped and can therefore also be referred to as a plate filer element5. The filter element5extends in particular largely in a plane which extends transversely to the axial direction8. The filter element5has a circumferential seal11, which engages in the flange region7. The seal11can in particular be injection-moulded or foamed onto a filter body12, which can be seen inFIG. 2. The filter element5separates an untreated side13from a clean side14in the interior of the filter housing2. As the filter element5is situated substantially between the two housing parts3,4, the untreated side13and the clean side14are arranged in different housing parts3,4. In the preferred example, the clean side14is thus situated in the first housing part3, whereas the untreated side13is situated in the second housing part4.

The first housing part3has two mutually opposite radial bearing faces15and16in the flange region7. In relation to the housing interior, one bearing face15is arranged radially further inwards than the other bearing face16, so the bearing faces15,16can also be referred to as inner bearing face15and outer bearing face16. The seal11has two radial sealing faces17and18, which face away from each other and bear flat against the bearing faces15,16when in the assembled state. In the diagram ofFIG. 1, the seal1is shown in a non-compressed starting state, so in the diagram ofFIG. 1the sealing faces17,18project radially over the associated bearing faces15,16. In reality, however, the seal11is compressed during assembly, as a result of which the sealing faces17,18are shifted radially towards each other. In the installed state the radially inner sealing face17then bears against the inner bearing face15, whereas the radially outer sealing face18bears against the outer bearing face16. The sealing faces17,18can also be referred to below as inner sealing face17and outer sealing face18. The outer sealing face18forms together with the outer bearing face16a first or outer sealing zone19between the seal11and the first housing part3. The inner sealing face17and the inner bearing face15form a second or inner sealing zone20between the seal11and the first housing part3. The two sealing zones19,20are arranged in series on the first housing part3, as a result of which a particularly effective sealing effect is achieved. An incorrect air flow or leakage flow between the clean side14and an environment21of the housing2can thus be avoided.

The first housing part3has an outer web22in the flange region7, which axial web projects axially from the first housing part3and runs in the circumferential direction. The outer web22has the outer bearing face16. The second housing part4likewise has an axial supporting face23in the flange region7, which supporting face runs in the circumferential direction. In the assembled state, the outer web22is supported axially on this supporting face23. Direct contact at the contact point6and consequently defined positioning between the two housing parts3,4is thereby produced in the axial direction8.

The first housing part3can also have a circumferential groove24in the flange region7, which groove is axially open towards the second housing part4and the mutually facing groove walls25,26of which have or form the two bearing faces15,16. The groove24has a groove bottom27between the two groove walls25,26. The said groove24delimits with its groove walls25,26and groove bottom27a receiving space28into which the seal11is axially inserted. The groove24and the seal11are matched to each other in terms of their dimensions in such a manner that an axial distance29is present in the axial direction8between the seal11and the groove bottom27, that is, a gap or a spacing between the groove bottom27and an axial end face30, which faces the groove bottom27, of the seal11.

In the example ofFIG. 1, the first housing part3is also provided with an inner web31, which is arranged circumferentially in the flange region7, projects axially from the first housing part3and has the inner bearing face15. The two webs22,31thus form the groove walls25,26and thereby define the groove24. It can be seen that the groove walls25,26in the axial section shown have a straight profile, the groove walls25,26running towards each other, that is, converging or tapering, in the direction of the groove bottom27.

A radial spacing32can be provided between the inner web31and the second housing part4, through which the seal11is guided. Further, the inner web31is shorter in the axial direction8than the outer web22.

The seal11can have a circumferential axial sealing face33in the flange region7, on which sealing face the inner web31is axially supported. An axial spacing35can likewise be present between this axial sealing face33which faces the inner web31and a further axial sealing face34, which faces the second housing part4, of the seal11. In the assembled state, this spacing corresponds with the axial length difference between the two webs31,22.

The seal11has the said sealing face34, which is likewise circumferential and which is situated on the seal11between the radial sealing faces17and18. A circumferential axial bearing face36, against which the axial sealing face34comes to bear axially when in the assembled state, is formed in the flange region7on the second housing part4. In the specific embodiment shown here, this axial bearing face36and the above-mentioned axial supporting face23are arranged axially at the same height. In particular, the supporting face23and the bearing face36can merge into each other in a transition-free manner or be formed by a common axial face which extends in a plane which runs transversely to the axial direction8.

According to a particularly advantageous embodiment, the seal11can have a circumferential slot region37, which is axially open towards the second housing part4and which is arranged radially between the two radial sealing faces17,18. The slot region37goes axially into the seal11without penetrating it in the axial direction8. For example, a slot depth38in the axial direction8is no more than half the size of an axial height39of the seal11. The axial height39of the seal11corresponds here to the axial spacing between the axial end face30and the axial sealing face34. In longitudinal section, the slot region37has a cross-sectional profile which tapers with increasing penetration depth into the seal11and thus has in particular converging slot walls40,41.

A plurality of radial webs42which are spaced apart from each other in the circumferential direction can be provided in the slot region37. The radially mutually opposite slot walls40,41can be supported radially on each other by means of these radial webs42. The radial webs42are expediently formed integrally on the seal11. In an alternative embodiment, the radial webs42can also be formed integrally on the second housing part4. A embodiment which comprises both radial webs42which are integrated in the seal11and radial webs42which are integrated in the second housing part4is likewise conceivable, housing-side radial webs42then going into the slot region37in the circumferential direction between seal-side radial webs42.

Instead of a plurality of radial webs42spaced apart from each other in the circumferential direction, a circumferential, axially projecting web can also be formed on the second housing part4, which web goes axially into the slot region37when the second housing part4is mounted.

A protective collar50is arranged circumferentially around the outside of the outer web22. This protective collar50is formed in one piece with the first housing part3. A contour51or a wall region51of the second housing part4engages between the outer web33and the protective collar50. A “chicane” is thus formed between the housing parts3and4, which prevents direct action of mechanical forces or penetration of dirt. Moreover, coarse positioning of the housing parts3,4with respect to each other can be achieved by this “chicane”, as a result of which assembly is made easier.

According toFIG. 2, the filter element5can have a polygonal, preferably rectangular, cross section in the axial direction, which has a plurality of corner regions43. In at least one such corner region43, the slot region37can have a radial recess44. In the example, the said recess44is situated in the radially outer slot wall41. It can be seen that the recess44does not penetrate the seal11. For example, the recess44reaches no more than half the wall thickness of the seal11in the [ . . . ] between the slot region37and the respective adjacent sealing face17or18.

As can be seen inFIG. 2, the radial webs42can each have two outer sides45, which face away from each other in the circumferential direction.FIG. 2shows different embodiments of the radial webs42, which can expediently be used alternatively or else can also be realised cumulatively or in virtually any combination. Four different radial webs42are shown by way of example inFIG. 2, which are referred to below clockwise as the first, second, third and fourth radial web42. In the first radial web42, the outer sides45extend parallel to each other and parallel to the radial direction. In the second radial web42, the two outer sides45again extend parallel to each other but are oblique to the radial direction. In the third radial web42, the associated outer sides45extend obliquely to each other in such a manner that they converge radially outwards. In the fourth radial web42, the outer sides45again extend obliquely to each other, but in such a manner that they diverge radially outwards.

Besides, the radial webs42can be the same size in the axial direction8as the slot region37regardless of the orientation of their outer sides45. It is likewise possible for the radial webs42to be smaller in the axial direction8than the slot region37. All the radial webs42can be the same size in the axial direction8. It is likewise possible for the radial webs42to be provided with different sizes in the axial direction8. InFIG. 1, an end-face-side end, which faces the second housing part4, of a radial web42which is shorter in the axial direction8than the depth38of the slot region37is indicated with a dashed line46.