IL225703A

IL225703A - Filter element and air filter

Info

Publication number: IL225703A
Application number: IL225703A
Authority: IL
Original assignee: Mahle Int Gmbh
Priority date: 2010-10-13
Filing date: 2013-04-11
Publication date: 2016-06-30
Also published as: IL225703A0; EP2627890B1; EP2674605A1; EP2674605B1; DE102010042426A1; PL2674605T3; WO2012049028A1; EP2627890A1

Description

225703/2 FILTER ELEMENT AND AIR FILTER The present invention relates to a filter element for an air filter of a fresh air system of an internal combustion engine, in particular of a motor vehicle, having the features of the preamble of Claim 1. The present invention also relates to an air filter equipped with such a filter element.

DE 202005 009 097 U1 discloses a filter element for an air filter, which has an annular filter body consisting of a filter material and two end discs which are arranged at axial ends of the filter body. The known filter element is arranged in a housing of an air filter, which has a tangential air inlet in the region of an axial end of the filter element, so that the air can flow into an annular space between a housing shell and the filter body with turbulence. The housing furthermore has a cylindrical wall in the region of the air inlet, which wall projects radially and axially into the annular space between the housing shell and the filter body. Direct loading of the filter body with the air stream entering through the air inlet can be avoided with the aid of the said wall.

With air filter which have a filter element in a housing, it has been found that a greater accumulation of dirt on the filter element can be observed in the region of the air inlet, which results in inhomogeneous loading of the filter element and thus to a change in the flow through the air filter.

EP 0 100 631 A2 discloses an air filter according to the features of the preamble of claim 1.

The present invention is concerned with the problem of specifying an improved embodiment for a filter element of the type mentioned in the introduction or for an air filter equipped therewith, which reduces a tendency towards inhomogeneous dirt accumulation on the filter element, the aim at the same time being a solution which can be realised in a cost-effective manner.

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

The invention is based on the general concept of applying a mask through which air can flow directly to the filter element, the mask only extending over a part-region of the filter body. To this end, the mask extends in the circumferential direction and axially along at least a part of the filter body. Although air can flow through the mask, it necessarily has a flow resistance, which can be used to influence the air flow through the filter body. In particular, the mask can be applied to the filter element in a targeted manner such that regions of the filter body which are exposed to greater loading by the air flow are largely shielded by the mask. This produces an equalisation of pressure and consequently homogenisation of the loading of the filter body by the air flow. Consequently, the tendency for the filter body to be stressed more within a limited region than in the other regions can be reduced. Consequently, a change in the flow conditions of the air filter can be reduced over the service life of the filter element.

The mask can be arranged directly on the filter body and touch it. In this configuration, the air to be cleaned must flow through the mask in order to flow through the filter body in this region. With a flat filter body such as a pad, the mask contacts the filter body over its entire area.

With other filter bodies which are formed for example by a pleated filter medium, the mask can only contact the filter body directly in part-regions, for example at the fold peaks. In other configurations, the mask can be arranged at a distance from the filter body, a gap being formed between the filter body and the mask. The air to be cleaned can flow through this gap and into the filter body. The filter body can in this case likewise be formed by any desired filter medium, which is shaped to form a pad or a pleated annular filter element.

The said mask extends particularly advantageously along the entire filter body, that is, virtually from one end disc to the other. The mask then only extends over part of the filter body in the circumferential direction. Alternatively, an embodiment is also conceivable in which the mask extends along the entire filter body in the circumferential direction, that is, runs around in a closed, virtually annular shape. The mask then only extends over part of the filter body in the axial direction.

The mask can be arranged radially on the outside of the filter body and be fastened to at least one end disc. In particular in the case of a filter body through which flow passes from the outside inwards, this results in effective protection of the filter body from excessive loading with the air flow from outside. Moreover, such an external mask can be applied particularly simply.

Alternatively, it is likewise possible to arrange the mask radially on the inside of the filter body and fasten it to at least one end disc and/or to an inner frame of the filter element which supports the filter body radially on the inside. In particular, such a mask can also be integrated in the inner frame, so that the inner frame has a flow resistance which varies in the circumferential direction and where necessary in the axial direction.

According to an advantageous embodiment, the mask can be formed by a lamellar structure which has a plurality of lamellae which run substantially parallel to each other, the individual lamellae preferably running parallel to the axial direction of the filter element.

Alternatively, it is likewise possible to form the mask with a perforated wall structure. Alternatively, a screen or grid structure can be used to realise the mask. According to further alternative embodiments, the mask can be formed by a non-woven or woven fabric. The mask can in particular have supporting geometries, with which stabilisation of the parts of the mask which form the flow resistance can be achieved with respect to for example mechanical stresses during assembly or flow pressures.

According to a particularly advantageous embodiment, the mask can be configured as an adsorber element for adsorbing hydrocarbons. The mask then obtains an additional function.

The mask can be fastened detachably or non-detachably to the respective end disc or inner frame. Detachable fastenings are for example clip connections, latch connections and screw connections. Non-detachable connections are for example adhesively bonded connections, welded connections or plastified connections. It is likewise possible in principle to produce the mask with at least one of the end discs and/or the said inner frame from one piece. Furthermore, the mask can be foamed into the end disc, the foam enclosing the end disc of the mask in this region.

According to the invention, the filter element has a rotation position pickup, which can in particular be formed on one of the end discs. The rotation position pickup makes it possible to detect the rotation position of the filter element, for example to be able to ensure proper assembly in the associated filter housing. Such a rotation position pickup can be advantageous for example for machine assembly. Such a rotation position pickup can in particular be expedient if the filter element is not circular but has a cross section which deviates from a circular shape. For example, elliptical or oval cross sections are conceivable.

One of the end discs can be configured as a closed end disc in such a manner that no fluid connection between an environment of the filter element and the interior of the filter element is possible through this closed end disc. The above-mentioned rotation position pickup can expediently be arranged on such a closed end disc.

At least one of the end discs is configured as an open end disc in such a manner that a fluid connection between an environment of the filter element and the interior of the filter element is possible through the open end disc. For example, an opening of the open end disc defines a cleanside outlet of the filter element. According to a specific embodiment, it can be provided for a connecting piece which encloses a central opening of the open end disc to be reinforced with the aid of at least one supporting strut which extends transversely to the axial direction of the filter element.

In the circumferential direction the mask extends expediently in a range from approximately 1/4 to approximately 1/2 inclusive of the entire circumference of the filter body, the mask preferably extending over approximately 1/3 of the circumference of the filter body.

According to another preferred embodiment, a flow resistance of the mask can be varied in the axial direction and/or in the circumferential direction by means of the mask. For example, the mask can be configured in such a manner that its flow resistance decreases in the axial direction from one end disc to the other end disc. Additionally or alternatively, the mask can be designed in such a manner that its flow resistance decreases in the circumferential direction starting from a centre of the mask to the circumference ends of the mask. By means of the flow resistance which is distributed in an inhomogeneous manner along the mask, a correspondingly inhomogeneous inflow to the filter element can be largely compensated in the region of the mask, which results in homogenisation of the inflow to the filter body in the circumferential direction and in the axial direction.

The air filter according to the invention has a housing, in which the filter element separates an outer untreated space from an inner clean space. This housing can expediently have an untreated-side inlet, which is assigned to an inlet region, which is delimited in the circumferential direction, of the housing. According to the invention the filter element is arranged in the housing in such a manner that the mask faces the inlet region of the housing. The supplied air flow thus impacts the mask first and can thereby be distributed better in the circumferential direction and where necessary in the axial direction of the filter element, which results overall in a homogenised flow into and through the filter element.

The inlet can particularly advantageously be arranged axially on the housing. It is then in particular not a tangential inlet but an axial inlet with an axially oriented inlet flow.

According to the invention, the housing of the air filter has a rotation position alignment means which interacts with the above-mentioned rotation position pickup and only allows insertion of the filter element in a predefined rotation position. The rotation position pickup and rotation position alignment means expediently interact by means of a form fit. For example, the rotation position pickup can be formed by a projection which projects from the filter element and interacts with a corresponding recess which is formed on the filter housing and forms the rotation position alignment means complementary thereto.

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.

In the figures, Fig. 1 schematically shows a perspective view of an air filter, Fig. 2 schematically shows a longitudinal section of the air filter, Fig. 3 schematically shows a perspective view of a filter element, Fig. 4 schematically shows a view as in Fig. 3, but with a different embodiment.

According to Figures 1 and 2, an air filter 1 which can be connected to a fresh air system 2 of an internal combustion engine, which can be situated in particular in a vehicle, comprises a housing 3, which has an untreated-side inlet 4 and a clean-side outlet 5. The housing 3 is connected with the outlet 5 to an air line 6 of the fresh air system 2, which conducts the clean-side fresh air further towards the internal combustion engine.

According to Figure 2, the air filter 1 also comprises an air filter element 7, which is arranged in the housing 3 and separates an untreated space 8 from a clean space 9. The filter element 7 is designed as an annular filter and therefore has an annular filter body 10 which consists of a suitable filter material. In relation to the filter element 7, the untreated space 8 is arranged on the outside, while the clean space 9 is situated in the interior of the filter element 7, that is, inside. The inlet 4 is coupled fluidically to the untreated space 8, while the outlet 5 is fluidically coupled to the clean space 9 when the filter element 3 is assembled.

According to Figures 1 and 2, the inlet 4 is arranged on the housing 3 in such a manner that an inlet region 11 can be assigned to it inside the housing 3, that is, in the untreated space 8, which region is delimited in a circumferential direction of the filter element 7. In other words, the inlet region 11 does not extend over the entire circumference of the filter element 7. The circumferential direction of the filter element 7 relates to a longitudinal centre axis 12 of the filter element 7, in relation to which the filter element 7 has an annular or cylindrical shape.

In the example, the filter element 7 has an elliptical or oval cross section. In principle, a filter element 7 with a circular cross section is also conceivable.

The filter element 7 is then arranged in the housing 3 in such a manner that the mask 19 faces the above-mentioned inlet region 11 of the housing 3.

Furthermore, the inlet 4 is arranged on the housing 3 axially, that is, parallel to the longitudinal centre axis 12 of the filter element 7 in the example. Consequently, the fresh air flows out of an environment 13 of the air filter 1 substantially axially, that is, parallel to the longitudinal centre axis 12 of the filter element 7 through the inlet 4 into the housing 3.

Furthermore, a rotation position alignment means 14 is arranged on the housing 3 or in the interior of the housing 3, which alignment means interacts with a complementary rotation position pickup 15, if such a rotation position pickup 15 is formed on the filter element 7. In the example of Figures 2 and 3, such a rotation position pickup 15 is provided on the filter element 7. When the filter element 7 is mounted or inserted into the housing 3, the rotation position pickup 15 interacts with the rotation position alignment means 14 in such a manner that the filter element 7 can only be inserted into the housing 3 in at least one predefined rotation position relative to the housing 3. In this manner a predefined rotation position can be ensured between the filter element 7 and the housing 3.

According to Figures 2 to 4, the filter element 7 comprises two end discs 16 and 17 in addition to its annular filter body 10. The two end discs 16, 17 are arranged on axial ends of the filter body 10. At least one of the end discs, in this case the end disc 16 reproduced on the left, is open and has a central opening 18. The clean-side air can exit from the interior of the filter element 7 from the clean space 9 towards the outlet 5 through this opening 18. In the example, the other end disc 17, which is situated on the right in Figures 2 to 4, is closed. Because the end disc 17 is closed in this manner, there is no fluid connection between the interior of the filter element 7 and the environment of the filter element 7, rather, the closed end disc 17 axially seals the filter element 7. In the preferred embodiment shown here, the rotation position pickup 15 is arranged on the closed end disc 17. It projects axially from the closed end disc 17 and can thus interact with the rotation position alignment means 14 of the housing 3.

In the air filter 1 shown here, the filter element 7 has a mask 19, through which air can flow and which extends only over a part-region of the filter body 10 in the circumferential direction. For example, the mask 19 extends over approximately 25% of the circumference of the filter body 10. The mask 19 can likewise extend along the filter body 10 in the circumferential direction over a maximum of 50% of the circumference.

In the embodiments shown, the mask 19 extends along the entire filter body 10 in the axial direction. The mask 19 thus extends from one end disc 16 to the other end disc 17. In principle, an embodiment in which the mask 19 does not extend over the entire axial length of the filter body 10 but only over an axial section is also conceivable. The mask 19 preferably begins at an end disc 16, 17. According to alternative configurations, the mask 19 can however also be arranged at an axial distance from the end discs 16, 17. In such configurations, the mask 19 can have fastening geometries which connect the mask 19 to one or both end discs 16, 17. In the installation situation of the housing 3 shown here, a mask 19 which does not extend over the entire axial length of the filter body 10 would begin at the open end disc 16 and extend in the direction of the closed end disc 17, for example over at least 50% of the axial length of the filter body 10. However, the embodiment shown here in which the mask 19 extends axially over the entire length of the filter body 10 is preferred.

The mask 19 is preferably arranged radially on the outside of the filter body 10 and fastened to at least one end disc 16, 17. The mask 19 is preferably fastened to both end discs 16, 17. For example, the mask 19 can represent a separate component from the end discs 16, 17 and be attached to the end discs 16, 17. The mask 19 can then be fastened detachably or non-detachably to the respective end disc 16, 17. Alternatively, it is likewise possible to form the mask 19 integrally on at least one of the end discs 16, 17. The two end discs 16, 17 preferably form an integral component together with the mask 19.

Alternatively, it is likewise possible to arrange the mask 19 radially on the inside of the filter body 10. The mask 19 can in this case be arranged or formed for example on an inner frame 20 of the filter element 7, which the filter element 7 can have on the inside to support the filter body 10. It is in particular possible for the mask 19 to be produced separately from the inner frame 20 and attached to the inner frame 20. Alternatively, the mask 19 can also be formed integrally on the inner frame 20. A mask 19 arranged on the inside of the filter body 10 can additionally or alternatively be fastened to at least one of the end discs 16, 17.

In the embodiment shown in Figure 3, the mask 19 is formed by a perforated wall structure 21, which is characterised by a shell body 22 which is perforated by a multiplicity of holes 23. In contrast, Figure 4 shows an embodiment in which the mask 19 is formed by a lamellar structure 24, which is characterised by a plurality of lamellae 25, which are fastened to each other by means of arc-shaped connection elements 26 at their axial ends. The lamellae 25 extend parallel to the longitudinal centre axis 12 of the filter element 7 and thus also parallel to each other.

Alternatively, it is likewise possible to form the mask 19 with a screen structure or grid structure.

According to a particularly advantageous embodiment, it can be provided for the mask 19 to be configured as an adsorber element, with the aid of which hydrocarbons CHX can be adsorbed .

The air which is to be cleaned with the aid of the filter element 7 can flow through the mask 19. To this end, the perforated wall structure 21 has the holes 23, whereas in the lamellar structure 24, the spacing between adjacent lamellae 25 allow flow to pass through the mask 19. The ability for flow to pass through the mask 19 is connected to a flow resistance, which results in the air entering the untreated space 8 being distributed better in the direction of circumferential regions of the filter body 10 which are not covered by the mask 19.

The flow resistance of the mask 19 can be distributed homogeneously over the entire extent of the mask 19. However, an embodiment is preferred in which the flow resistance of the mask 19 varies over the mask 19 only in the axial direction or only in the circumferential direction or both in the axial direction and in the circumferential direction. For example, the flow resistance of the mask 19 can decrease in the axial direction from the open end disc 16 towards the closed end disc 17. In the case of the perforated wall structure 21, this can be realised by the number of openings 23 per unit area decreasing and/or by the opening sizes of the openings 23 increasing in the said axial direction. In the case of the lamellar structure 24, a width 27 of the lamellae 25 measured in the circumferential direction can reduce in the axial direction from the open end disc 16 to the closed end disc 17.

Additionally or alternatively it can be provided for the flow resistance of the mask 19 to reduce in the circumferential direction from a centre 28 of the mask 19, indicated with dash-dotted lines, to the circumferential ends 29, of which only one can be seen in Figures 3 and 4. In the case of the perforated wall structure 21 this can be realised e.g. by the number of holes per unit area reducing with increasing distance from the centre 28 in the circumferential direction. Additionally or alternatively, the opening size of the openings 23 can increase with increasing distance from the centre 28 in the circumferential direction. In the case of the lamellar structure 24, it can be provided for the width 27 of the lamellae 25 measured in the circumferential direction to be reduced starting from the centre 28 in the circumferential direction. With decreasing width 27, the spacing or gaps between adjacent lamellae 25 increase, which reduces the flow resistance of the mask 19.

In the embodiments shown here, an outlet connecting piece 30 which encloses the circumference of the opening 18 of

Claims

225703/2 CLAIMS

1. An air filter for a fresh air system of an internal combustion engine, in particular of a motor vehicle, having a filter element comprising an annular filter body and two end discs, wherein said filter body consists of a filter material, wherein said end discs are arranged on axial ends of the filter body, wherein a mask through which air can flow is provided on the filter body, which mask only extends over a partregion of the filter body, wherein the mask extends in the circumferential direction and axially along at least part of the filter body, having a housing, in which the filter element separates an outer untreated space from an inner clean space, wherein the housing has an untreated-side inlet, which is assigned to an inlet region, which is delimited in the circumferential direction, of the housing, wherein the filter element is arranged in the housing in such a manner that the mask faces the inlet region, characterized in that the filter element has a rotation position pickup, that the housing has a rotation position alignment means, which interacts with the rotation position pickup and only allows the filter element to be inserted in a predefined rotation position relative to the housing.

2. Air filter according to claim 1, characterised in that the rotational position adjustment means is provided separately to the cover.

3. Air filter according to either claim 1 or claim 2, characterised in that the rotational position adjustment means is formed on one of the end discs.

4. Air filter according to claim 3, characterised in that the rotational position adjustment means is arranged axially externally on the respective end disc.

5. Air filter according to either claim 3 or claim 4, characterised in that the respective end disc comprising the rotational position adjustment means is designed as a closed end disc .

6. The air filter according to any one of Claims 1 to 5, characterised in that the inlet is arranged axially on the housing.

7. The filter element according to any one of Claims 1 to 6, characterised in that - the mask is arranged radially on the outside of the filter body and fastened to at least one end disc, or - the mask is arranged radially on the inside of the filter body and fastened to at least one end disc and/or to an inner frame which supports the filter body radially on the inside.

8. The filter element according to one of Claims 1 to 7, characterised in that the mask is formed by a lamellar structure, or the mask is formed by a perforated wall structure, or the mask is formed by a screen structure, or the mask is formed by a grid structure, or the mask is formed by a non-woven or woven fabric .

9. The filter element according to one of Claims 1 to 8, characterised in that the mask is configured as an adsorber element for adsorbing hydrocarbons .

10. The filter element according to one of Claims 1 to 9, characterised in that the mask is fastened detachably or non-de tachably to the respective end disc and/or to the inner frame according to Claim 3.

11. The filter element according to one of Claims 1 to 7, characterised in that a flow resistance of the mask varies over the mask in the axial direction and/or in the circumferential direction .

12. The filter element according to Claim 11, characterised in that the flow resistance of the mask to decrease in the axial direction from one end disc to the other end disc .

13. The filter element according to Claim 11 or 12, characterised in that