EP2185268A2

EP2185268A2 - Filter element

Info

Publication number: EP2185268A2
Application number: EP08786813A
Authority: EP
Inventors: Stefan Walz; Michael Durst; Markus Kolczyk; Jobst Eisengräber-Pabst
Original assignee: Mann and Hummel GmbH
Current assignee: Mann and Hummel GmbH
Priority date: 2007-08-08
Filing date: 2008-08-04
Publication date: 2010-05-19
Also published as: WO2009040170A3; DE202007011097U1; WO2009040170A2

Abstract

The invention relates to a filter element (1), especially an air filter for a motor vehicle, comprising an inner region (2) having a periphery (U) and a longitudinal extension. The inner region (2) is surrounded, on its periphery, by a fluid-permeable filter material essentially folded lengthwise along the longitudinal extension (L) thereof, and at least a selection of folded edges (3) of the longitudinal folds (18) is mutually fixed by fixing means applied to the folding edges (3). The filter element (1) can be reversibly compressed or stretched by a plurality of transversal folds (3) of the filter material in at least the longitudinal extension (6), and the transversal folds (3) are formed at a discrete angle to the direction of the longitudinal extension. Fixing means (7) are provided for fixing a distance between at least a selection of folded edges (12) of the transversal fold (3).

Description

description

filter element

Technical area

The invention relates to a filter element, such as for filtering air, in particular for filtering combustion air in internal combustion engines or air for the vehicle interior with rigid or flexibly adjustable longitudinal and / or transverse extent. Furthermore, the invention relates to a receiving device for a filter element and a filter assembly.

State of the art

Especially in the automotive field, it is necessary to clean the air required for the combustion of fuels prior to feeding into the internal combustion engine. This is usually done by air filters, which are installed in the respective Verbrennungsluftansaugrohr. It is often desirable because of limited space resources to create a particularly compact arrangement. Furthermore, an exchange of dirty filters should be easily possible. In the past, essentially rigid filter elements from fold packs were provided in a suitable filter housing. Usually, such Faltenpacks are cuboid or executed in the manner of a cylinder. DE 20 2004 003 326 U1, for example, discloses a corresponding filter element.

A disadvantage is, for example, the complex installation and replacement of appropriate filter elements, since it must be clamped between head and foot end plates of the cylinder. Desirable are also lightweight and constructed from a few components filter to reduce manufacturing costs. Nevertheless, a sufficient stability of the filter material in particular is required so that no deformation occurs during the flow of the medium to be filtered and obstructs the filtering. It is therefore an object of the present invention to provide an improved filter element. Disclosure of the invention

This object is achieved by a filter element with the features of claims 1 and 10 and a receiving device with the features of claims 3 and 15.

Accordingly, a filter element is provided, which is designed in particular as an air filter for a motor vehicle. The filter element has an interior with a circumference and a longitudinal extent. In this case, the interior is enclosed by a fluid-permeable filter material folded along the circumference along the longitudinal extent along the longitudinal extent. At least one selection of folding edges of the longitudinal folds is fastened relative to each other by fixing means resting against the folding edges.

As a rule, a fluid to be filtered flows through the filter material radially, that is to say perpendicular to the longitudinal extent. For example, air to be filtered may enter the interior space, flow through the filter material, and exit outside as clean air. This usually creates a pressure difference between the interior and the outer space of the filter element. Since the stability of the filter element is at least partially created by the longitudinal folds, the volume flow can be occupied by occupying the filter material with particles to be filtered so that the internal pressure deforms the folds and folds. The filter element according to the invention, however, has fixing means, on the one hand fix the distances of the folding edges to each other and on the other hand support the zigzag folds, for example.

The filter element may, for example, be tubular in shape with a substantially circular cross-section, which is enclosed by the circumference. In this case, the filter element is designed substantially symmetrical to a longitudinal axis. The zigzag folds can be formed by a filter material sheet along the circumference, wherein the sheet is glued together or otherwise attached tubular. In this case, the filter element is particularly suitable for insertion into a tubular receiving device. In order to specify a radial fluid flow, an opening section for the inflow and / or outflow of fluid to be filtered can be provided, and a distal end section can be attached along the longitudinal extension for closing the interior space. In this case, fluid, such as polluted air, flows into the interior space and can only flow off radially, that is to say through the filter material which forms the circumference.

In an alternative embodiment, the filter element is cone-shaped with a substantially transverse from the opening portion to the closed end portion of the filter element tapered round cross-section. It can be carried out symmetrically to a longitudinal axis substantially. With such a conical configuration, the tapered circular cross-section perpendicular to the longitudinal extent of the pressure increases by the flowing fluid to the distal end. This assists a particularly uniform radial outflow of the cleaned air over the longitudinal extent. Furthermore, the cone-shaped design results in improved stability, since the folding density generally increases towards the tip end of the cone.

Preferably, for guiding a fluid flow inside or outside of the filter element, the longitudinal folds are designed such that they rotate around the interior of a thread. The air flow is thereby forced on a twist, whereby it is made possible, for example, that coarse particles do not strike the filter medium itself and have to be deposited there, but are already removed by means of the flow guide in the manner of a pre-separator from the raw air.

The fixing means may preferably be formed by applied to the folding edges of material threads, such as glue threads, by glued to the edges of threads and / or stapling devices. The material threads are for example made of a thermoplastic material, so that liquid material is brought to or on the folded edges during manufacture and then cured. The fixing agents may further be executed elastic, so that a certain expansion of the circumference can be done by the internal pressure in the filter element.

There are preferably provided further fixing means, which are formed on the inside or outside in the shape of the folding profile and support the longitudinal folds. This can be done, for example, in a zigzag profile, which engages from outside or inside the folding valleys.

The further fixing means may for example be arranged circumferentially at predetermined intervals along the longitudinal extent of the filter element from each other inside or outside the respective circumference. Due to the predetermined distances, the material that must be used for the fixing, may be limited. The distances between the fixing means should be dimensioned such that there is sufficient stability even when flowing with fluid to be filtered.

In one embodiment, the further fixing means, for example, in the manner of a scaffold inside and / or outside arranged to support the filter material. Usually, the filter material is made of a foldable nonwoven material, in particular of plastic fibers, which may be felted.

The invention further relates to a receiving device for a filter element with the features of claim 12.

In this case, the filter element has an interior with a circumference and a longitudinal extent, wherein the interior is substantially enclosed by a along the longitudinal extent longitudinally folded fluid-permeable filter material along the circumference. The receiving device encloses the filter element and has fixing means which fixes at least one selection of folding edges of the longitudinal folds relative to one another.

The receiving device thus stabilizes the folds of the filter element, as well as the flow through the filter element, the various folding edges can not slip relative to each other by the fixing. This practically prevents that from happening For example, in an embodiment in which the fluid flows from the internal space to the outside space, the folds are pressed against a surface or inner wall of the receiving device and thus the filtration area and the filter efficiency is reduced.

The receiving device preferably forms a cavity for receiving and the fixing means are designed on the inside along the longitudinal extent of the filter element in the manner of a groove. Through the groove, the selection of Längsfaltkanten be performed.

The groove may have a rectangular, triangular or semi-circular cross section, so that the folding edges find depending on their predetermined folding angle recording and stabilization. In this case, also preferably all folding edges are guided by corresponding grooves. Preferably, the grooves are discontinuous along the length and provide the guidance and stabilization in the form of pins, pins, protrusions, or they are formed in the shape of the folding profile for supporting the longitudinal folds.

The fixing means may be designed such that at least one longitudinal fold is guided threadwise through the fixing means along the longitudinal extent. This results in a turbulence of the fluid flow present in the interior of the filter element and potentially improves the filter effect.

In one embodiment of the receiving device, the fixing means are designed in the manner of guide rails that outer folding edges of the longitudinal folds along the longitudinal extent on an inner side of the receiving device can be inserted. In such an embodiment, the width for introducing the folding cold of the guide rails preferably decreases from an insertion opening of the receiving device in the direction of the longitudinal extent of the receiving device or of the filter element. This allows a particularly simple introduction of the filter elements in the receiving device. It thus takes place by the rejuvenation funnel-like shape of the guide rails, wherein in particular during insertion and replacement of the filter element is a simple and convenient fixation.

In a variant of the receiving device, the receiving device for receiving a conical filter element, which has a substantially tapered from the opening portion to an end portion of the filter element cross-section executed. In this case, the receiving device is executed substantially symmetrical to a longitudinal axis.

Preferably, for example, in order to achieve a saving of material for the fixing means, the fixing means are arranged at predetermined intervals along the longitudinal extent of the filter element from each other on an inner side of the receiving device. The fixing means may therefore be formed in the form of pins, pins or protrusions in the inner wall of the receiving device.

Furthermore, the invention provides a filter assembly with a receiving device according to the above description and a filter element having an interior, which has a circumference and a longitudinal extent, wherein the interior of a substantially along the longitudinal extent longitudinally folded fluid-permeable filter material is enclosed along the circumference. In this case, preferably, the receiving device and the filter element are arranged substantially concentric.

Furthermore, a filter element, in particular an air filter for a motor vehicle is provided, which has a cavity with a longitudinal extent and a transverse extent of a fluid-permeable filter material. In this case, the filter element is reversibly compressible and / or stretchable by multiple transverse folds of the filter material in at least the longitudinal extent. Transverse folds are formed at a non-zero angle to the longitudinal extension direction. The filter element has fixing means for fixing a distance between at least one selection of folding edges of the transverse folding. The filter element may for example be formed tubular, the transverse folds allow a concertina-shaped compression and stretching along the tube axis. As a measure of a cross section or a transverse extent, for example, serve a corresponding rotary blade. By a non-vanishing angle is meant that the transverse folds do not have parallel but an angle greater than zero degrees with the longitudinal extent or longitudinal axis of the filter element. However, these folds present in the initial state can also have zero degrees in the complete load state when the filter element is maximally stretched. In a corresponding tubular embodiment, the fluid to be filtered, such as intake air for an internal combustion engine, enter through an opening in the tube and then radially, ie from the inside to flow through the filter material or filter medium. By the bellows-like or accordion-like transverse folds of the filter material, which may be made for example of a flexible nonwoven material, it is possible to change the length of the entire filter element practically arbitrarily. By upsetting, thus creating particularly high folding densities, the length of the filter element is shortened.

In addition to the transverse folds longitudinal folds are also possible, which have substantially an acute angle with the longitudinal extent of the filter element. Preferably, the transverse folds are executed perpendicular to the longitudinal extent or longitudinal axis.

By the fixing means, which can be realized for example by a thread winding, stapling devices, adhesive on the inside or outside of the cavity, applied filter material strips and / or stiffened transverse folds, can form sections of the filter element, in which the transverse folds particularly dense stand together, that is, the distances between adjacent folding edges of the transverse folding are particularly low. If necessary, even very large distances can be achieved Achieve fixative, selbige example, act as a spacer between the folds.

In a tubular embodiment of the filter element can be done by the pleat structure and a flexible deformation of the entire filter element perpendicular to the longitudinal extent. That is, it is conceivable s-shaped or arbitrarily shaped arrangements. These can be stabilized by the fixing means, which in each case fix the inner and outer folding edges together in a rounding, for example. The fixing means, which fix a plurality of folding edges with respect to their relative position to each other, may also be formed as part of a receiving device such as a housing for the filter element.

In a variant of the filter element, the cavity is formed from a folded sheet of filter material and one or two closure sections. The filter material may be multi-layered and comprise, for example, polyester fibers as a flexible nonwoven material. In the case of a tubular cylindrical or hollow-cylindrical filter element, a closure section, for example, also of a different material than the filter medium, such as foam, PUR foam or plastic, can be arranged at one end section so that a fluid flow has to pass radially through the filter material. It can form a variety of cross-sections, such as polygonal, which form a round base of a cylinder in the limit. However, square, rectangular or hexagonal cross sections are also conceivable.

In one embodiment of the filter element, the transverse folds are formed such that when flowing through the filter material by a pressure difference between the cavity and an outer space of the filter element, a compression or extension of the longitudinal extent occurs. In particular, by loading the filter material, ie setting of particles to be filtered, for example, in filter fleece, the volume flow changes through a corresponding portion of the filter element. This is also the flow resistance of the flow variable. This can also be changed by the pleat spacing, ie the density of adjacent transverse folds.

For example, the filter element is provided with an opening portion having an opening and a distal end of the opening portion along the longitudinal extension end portion with a fluid-tight seal. The closure may be in the form of a plug, for example, or of filter material or fluid-tight materials, such as PUR foam.

Furthermore, the invention provides a receiving device for a filter element according to claim 15.

The corresponding receiving device is suitable for receiving a filter element which has a cavity with a longitudinal extent and a transverse extent of a fluid-permeable filter material. In this case, the filter element is reversibly compressible and / or stretchable by multiple transverse folds of the filter material in at least the longitudinal extent. The receiving device has fixing means for fixing a distance between at least one selection of folding edges of the transverse folding of the filter element.

Since the surface of the folding element is adjusted by the folding density in a region of the filter element which is exposed to a fluid flow, the receiving device can be designed with fixing means in such a way that only part of the longitudinal extent of the corresponding filter element is flowed through. This makes it possible to realize different sections with different folding densities. It is then also possible to define longitudinal areas of the filter element in that the folding density is particularly high, that is to say the folding edges virtually adjoin one another, and can be used as a depot. As soon as further unfolded regions of the filter element are loaded with particles, further clean or unloaded folding sections can be pushed out of the depot area into the region of the filter housing or the receiving device be, which will then represent a lower flow resistance for the medium to be filtered.

For example, the receiving device may have such a first and second section with fixing means that the filter element is held by the two sections and between the two sections, the distances between the folding edges are larger than between the fixed by the fixing folding edges. As a possible fixing means, the receiving device may have a portion which has such a dimensioned cross-section that the selection of folds of the filter element is produced by a bond between the wall of the portion of the receiving device and the folding edges of the filter element. Of course, other fixing elements such as brackets made of housing material, metal or plastics are conceivable.

In one embodiment, the receiving device is designed tubular for receiving a tubular filter element. A section of the receiving device in this case has a cross-sectional diameter which substantially corresponds to the cross-sectional diameter of the filter element. In this case, a loose mounting of the filter element can be realized or the same can be held by adhesion with outer fold edges.

Furthermore, the invention provides a filter assembly with a previously described receiving device and a filter element, which has a cavity with a longitudinal extent and a transverse extent of a fluid-permeable filter material, wherein the filter element by multiple transverse folds of the filter material in at least the longitudinal extent reversibly upsetting and / or is stretchable.

Further advantageous embodiments of the invention are the subject of the dependent claims and the embodiments described below.

Brief description of the drawings In the following the invention is based on preferred embodiments below

Reference to the attached figures explained in more detail. FIG. 1 shows a perspective view and a cross section of a first embodiment of a filter element; FIG. Fig. 2 is a perspective view and a cross section of a second embodiment of a filter element; 3A, 3B: a perspective view of a filter assembly with a filter element and a receiving device in perspective and cross-sectional view. FIG. 3C is a detail view of one embodiment of fixation means; FIG.

Fig. 4: a perspective view and cross sections of another

Embodiment of a filter arrangement; and Fig. 6 is a perspective view and a cross section of still another

Embodiment of a filter arrangement. Fig. 6 is a perspective view of a first embodiment of a filter element and possible folding arrangements;

Fig. 7 is a perspective view of a second embodiment of a filter element; Fig. 8, 9 further embodiments of filter elements with possible

fixers; Fig. 10 is a cross-sectional view of a first embodiment of a

Filter assembly with a filter element and a receiving device; Fig. 11 is a cross-sectional view of a second embodiment of a

Filter arrangement; Fig. 12 is a detail view of a closed end portion of a

Embodiment of a filter element; 13 shows a detailed view of a further embodiment of a filter arrangement. In the figures, the same or functionally identical elements have been given the same reference numerals, unless stated otherwise.

Embodiment (s) of the invention

FIG. 1 shows a first embodiment of a filter element. Here, FIG. 1A shows a filter element 1, which is formed from a zigzag-folded sheet of a filter fleece material. In this case, the embodiment of a filter element shown in FIG. 1A is in the form of a cylinder. The filter element 1 has a longitudinal extent L and a substantially round cross-sectional area with a circumference U. As a result, an inner space 2 is enclosed by the folded filter material. For example, the filter element 1 can likewise be introduced into a tubular, ie cylindrical housing, wherein fluid enters and exits through the interior 2 and the folds. It is also conceivable an opposite direction of flow, penetrates from the outside to be filtered fluid, such as contaminated air, through the filter material or the fold sections 18 into the interior and as clean air taken there. When filtering arises between the inner space 2 and the outer space, a pressure difference, which exerts a force on the filter fabric. This force increases with increased loading, so pollution of the filter material. Furthermore, this force is dependent on the volume flow flowing through the filter element. That is, on the folding edges 3, which constitute a substantial stabilization of the filter element 1, an increased pressure or a force is exerted. So that the folding edges do not slip during operation of the filter and, for example, overlap one another, fixing means 4 are provided which fix the folding edges 3 in their relative distance from one another. This is shown in more detail in FIG. 1B. The convolutions 3 are executed here parallel to the axis of symmetry S. FIG. 1B shows a cross-section of the filter element 1. In this case, a fixing means 4A circulating around the circumference U, such as a plastic strip or glue strip or wire is provided which has recesses or staples 4B at certain positions of the circumference, into which a folding edge 3 can engage the longitudinal folding. In the figure 1 B is also shown schematically by the arrow L1, as the fluid to be filtered from the inner to the outer space can flow. By the fixing means, such as the plastic wire 4A, which has provided at certain points retaining pins 4B, prevents the folding edges 3 slip at least a selection of folds 18. The fixing means 4 can also be designed such that all outer folding edges 3 are fixed to each other. Also possible is a fixation such that fixing means 12 are provided, which simulate a folding profile in cross-section and thus also fix the inner fold edges 19 or support the fold 18 as a whole.

FIG. 2 shows a second embodiment of a filter element. The filter element 1 is conical in shape and has a folded nonwoven filter material, wherein an opening portion 6 has a larger cross section than an end cap 7, which is formed in Figure 2 for example by another material in the manner of a plug. The end portion 7 can be formed, for example, of foamed plastic material or silicone or PUR foam and stabilizes in the end portion of the folds 3, 18 of the filter element 1. It is also conceivable to make the end portion 7 of nonwoven filter material. For example, the folds may be enclosed by the foamed plastic end section 7 at the end section. The conical design of the filter element 1 has a longitudinal extent L along an axis of symmetry S.

In the embodiment of FIG. 2A, the end section 7 with its foamed plastic material, for example, simultaneously serves as a fixing means for the folds 3, 18. However, it is also possible to provide further fixing means, as have been explained using the example of FIG.

In order to achieve stabilization of the folds 3, 18 on the inside as well, a scaffold 20 made of plastic, for example, as shown in FIG. 2B, can be introduced into the interior 2. It is also conceivable, however, a framework-like conversion of the filter element 1. For this purpose, the frame-like fixing means 20 has a likewise conical structure, wherein the conical surface is simulated by a mesh or grid. Circumferential circular sections 9 are provided for this purpose and longitudinal sections 8, which extend, for example, along inner longitudinal folds 19. Further, even if not shown in FIG. 2B, further fixing means, such as pins or clamps on the frame 20, are conceivable which support or stabilize the mutual position of the folds 3, 18, 19 of the filter element 1.

FIG. 3 shows a filter arrangement 10 with a filter element 1 and a receiving device 11, such as a filter housing, for example. FIG. 3A shows a perspective view of a corresponding filter arrangement 10, FIG. 3B shows a cross-sectional view, and FIG. 3C shows a detailed view of a fixing means which is provided along the inside of the housing 11.

With reference to FIG. 3A, a filter element 1 is shown inserted in a filter housing 11. The filter housing 11 encloses the filter element 1, which is similar in shape to that of Figure 1A. However, no fixing means are provided directly on the filter element, but arranged in or on the receiving device 1 1. In the embodiment of Figure 3A, the filter element 1 and the housing 11 are arranged axially symmetrically according to the longitudinal axis S. The filter assembly thus formed has an opening portion 21 through which, for example, air to be cleaned enters the interior space 2 of the filter element through which the filter element material flows and flows into a gap 14 between the housing wall 11a and the folds of the filter element 1. From there, the purified air can be tapped.

This is shown in a cross-sectional view in FIG. 3B. The arrows L1 indicate the fluid flow. The filter housing or the housing wall 11 has fixing means 12, 13. The fixing means 12 form a fold profile of the longitudinal folds of the filter element 1 or they have substantially the same profile as the filter folds. As a result, both the inner filter edges 19, as well as the outer filter edges 3 are fixed in the region of the fixing means 12 and are not deformed by a fluid flow, which exerts a force on the filter material. The corresponding fixing means may be provided at certain intervals along the longitudinal axis, so that the purified air from the intermediate space 14 can be easily removed.

Further, fixing means 13A, 13B, which are made in the shape of a groove, are shown in FIG. 3B. The corresponding groove rail can for example be arranged completely axially parallel to the symmetry axis S on the inside of the housing 11. The filter element 1 can thus be easily introduced and fixed along these guide rails formed by the two groove sections 13A, 13B along the longitudinal axis of the housing wall inner wall.

FIG. 3C shows a detailed view of a particularly preferred embodiment of such groove rails. 3C shows a plan view, ie from the direction of the symmetry axis S on the inside of the housing wall 11. In the region of the opening portion 21, the two parts 13A, 13B of the groove have a wider distance B than at the end portion 7 of the housing. The distance between the two groove rails or guide rails 13A, 13B thus decreases to a smaller distance b. As a result, a longitudinal fold 3, 18 can first be easily introduced into the larger distance B between the groove parts 13A, 13B and then becomes tapering distance between the two guide rails 13A, 13B fixed within the housing. By means of the arrow R, the insertion movement of the folding edge 3 in the guide rail from the two groove parts 13A, 13B is indicated.

4 shows a further embodiment of a filter assembly 10 with a filter element 1 and a filter housing 11. In this case, Figure 4A shows a perspective view and Figures 4B-4D cross-sectional views through the filter assembly 10. The housing 11 is cylindrical and the Filter element 1 conical. The filter element has an opening section 6 and a closing section 7. As shown in FIG. 4A via the arrows L1, unfiltered air RO initially flows into the interior space 2 and exits through this filter material into the intermediate space 14 as filtered clean air.

The receiving device or the filter housing 11 may for example be designed in the form of a tube, wherein at predetermined intervals A1, A2 along the longitudinal extent of the filter element 1 and the housing 11 fixing means 15, 16, 17 are arranged. These hold on the one hand the filter element 2 concentrically in the tubular receiving device 11 and fix at least a selection of folds of the filter element. The fixing means 15, 16, 17 are for example struts which extend concentrically radially into the interior of the housing 1 1 and engage outer folding edges 3 of the filter element.

For example, FIG. 4B shows a cross section through the filter arrangement 10 in the vicinity of the opening section 6, 21. The outer folding edges 3 substantially abut against the housing 11. Furthermore, by way of example, four fixing means 17 are shown which abut against fold edges 3 of the filter element 1 at four positions. The four folding edges 3 supported by the fixing means 17 are fixed relative to each other in their relative distance. Four fixing means, which have a triangular notch into which an outer folding edge 3 can engage, are shown in FIG. 4B by way of example only. It is also possible to provide more, for example, fixing means 3 suitable for each folding edge 3 of the filter element. At a distance A1 along the longitudinal axis of the filter element 1 and the housing 11 fixing means 15 are again provided, which are designed radially in the direction of the axis of symmetry and notches for receiving folded edges 3 of the filter element 1 have. Since the filter element 1 should be as central as possible in the housing 11, the fixing means 15 have corresponding lengths. At a further distance A2 along the longitudinal axis of the filter assembly 10 fixing means, which extend radially into the interior of the housing, are provided again. This is shown in cross section in FIGS. 4C and 4D.

In addition to the housing and filter element shapes illustrated in FIGS. 1 to 4, further conceivable are conceivable. For example, Figure 5A shows a perspective view of a filter element in a housing with a square or rectangular cross-section. FIG. 5B shows a corresponding cross-sectional view.

FIG. 6A shows a perspective view of a tubular or tubular filter element 101. This can be made from a single filter web 102 or sheet 102 of filter material as shown in Figure 6B. By folding the sheet 102 of filter material, the tubular structure of FIG. 6A can be produced by rolling up the sheet and bringing the lines 104 along and then folding along the folding line 103 shown by way of example. The areas 108 then overlap in the assembled and bonded state. This results in a symmetrical, with respect to the axis of symmetry S 'tubular filter element 101. The fold lines 3 shown in Figure 6B are perpendicular to the axis of symmetry S' or longitudinal extent 106 or include an angle α with the axis of symmetry S 'a. Of course, other folding patterns are conceivable that realize different cross-sectional areas for the filter element 101. In particular, however, by the arrangement of the transverse folds 103 results in the direction of the axis of symmetry S 'in principle upsetting and stretchable tubular filter element. In FIG. 6B, dashed and solid fold lines 103 each indicate folds in different orientations. The resulting filter element, as shown in FIG. 6A, consists of a sequence of triangular cross-sections 105, which lead overall to an approximately hexagonal cross-sectional area of the filter element 1. The filter element 101 is further provided with fixing means 107 which fix the folding distances of the transverse folds. As a result, compression or stretching in the region where the fixing means are arranged is prevented. For example, a strip of filter material can be adhered to the folded edges and thus fix the distances between edges.

For example, air filtering takes place through the filter element 101 by raw air enters the interior of the tube and passes radially through the filter material to the outside. For this purpose, for example, an end portion can be provided which closes one of the tube-shaped or tubular openings. However, the air filtration can also take place in the opposite direction of flow.

FIG. 7 shows a perspective view of a second embodiment of a filter element. The filter element 101 is in turn made flexible by suitable transverse folds 103 compressible and stretchable in the longitudinal direction. In FIG. 7, the filter element 1 has a substantially octagonal cross-section which results from the draw-harmonicoid fold. For example, felt materials or nonwoven materials made of synthetic fibers may be used as the filter material, which may also be multi-layered, as long as convolutions are still possible. The nonwoven may further be coated with, for example, activated carbon particles in order to achieve an adsorptive effect.

Through the tubular or tubular filter element 101, a cavity 122 is formed, can enter the raw air RO 'and filtered clean air RE' again passes to the outside. It is also possible to perform an opposite filter direction in which a raw air flows through the filter material into the interior or cavity 122 of the filter element 101 and is tapped from this interior. In contrast, FIG. 7 shows an embodiment in which an opening section 109 is a provides not visible because of the perspective view opening can flow through the raw air RO '. A closure portion 110 disposed distally along the longitudinal extent 106 of the filter element 101 and opening portion 109 is formed by a suitable closure 111 of the tube opening.

By inflow of the unfiltered air, the filter element 101 would balloon-like expand without additional fixation of the convolutions 103. To prevent this at least partially, on one side substantially perpendicular to transverse folds a strip 107 is glued or fixed, which serves as a fixing means for the underlying fold edges 112. This ensures that a reliable fluid flow through the filter material is possible in this region or section 113 of the filter element 101.

FIG. 8 shows another embodiment of a filter element 101 in cross section. In this case, by the arrangement of a plurality of transverse folds 103, of which only one is provided with the reference numeral 103, a compression and extension in the longitudinal extension 106 of the filter element 101 is possible. A transverse extent in the direction of the diameter D is substantially unchanged. Raw air RO 'flows through an opening 129 into the interior 122 of the filter element, which is closed by an end 111 with an end section 110. The closure 111 can be, for example, a plastic pane glued to the peripheral edge 130 of the end section 110. The clean air RE 'then exits radially from the filter element 101.

A longitudinal section 134 is provided in the vicinity of the end section 110 of the filter element 11, on which fixing means 131 and / or 132 fix the distance between folds 124, 125. The fixing means 131 is made for example as a staple or stapler made of suitable material, such as plastic or metal. The fixing means 132 is realized, for example, as an adhesive strip applied perpendicular to the transverse folds 124, 125. By fixing in the region 134 of the pleat spacings, the longitudinal extent 106 of the permeable filter medium is determined. Thus, by set suitable fixing means 131, 132 set and adjusted starting from a filter element without such folding fixation of the flow resistance for the medium to be filtered.

FIG. 9 indicates a further possibility of folding fixation by fixing means 133. Here, glue threads are wound diagonally at an angle to the transverse folds, for example, around the tubular filter element 101 and glued. The thread winding 133 is defined in the figure 9 by the dotted lines. The thread winding can be easily different areas 134, 135 realize with different folding distances. For example, the convolution density in section 134 is higher than in section 135, as shown in FIG.

FIG. 10 shows a filter arrangement with a receiving device 116, or a filter housing, and a filter element 115 inserted therein. In this case, a simplified cylindrical geometry of the filter element 115 is assumed.

The filter element 115 is configured such that through the transverse folds 103 a compression or extension in the longitudinal direction, ie parallel to the axis of symmetry S 'concertina-shaped is possible. The housing 116 is also constructed of cylindrical sections 134, 136, wherein the wall of the housing 116 and the cylindrical shape of the filter element 115 are arranged concentrically. The housing 16 has a receiving portion 134 whose diameter D substantially corresponds to that of the filter element 115. Further, the receiving portion 134 is closed by a closure 111, which is glued, for example, with the end portion or the peripheral edge 130 of the filter element 115 and therefore the filter element 115 seals tight.

Alternatively, the diameter of the receiving portion 134 may also be dimensioned such that an adhesive bond between the edges 120 of the folds 103 of the filter element 115 with the housing wall 135 of the portion 134 occurs. A mean flow area 136 of the filter housing 116 has a larger diameter than the filter element 115, so that in this area filtered air L 'exits from the interior 122 of the filter element into the interior 137 of the housing 116. The housing is provided in the flow-through region 136 with an outflow opening 138, on which the filtered clean air RE 'can emerge.

The opening portion 109 of the filter element 115 is placed on an insertion piece 139 of the housing 116. Furthermore, further fastening means can be provided, which realize a tight edge closure with the connection piece 139. In the embodiment of the filter arrangement in FIG. 10, the fixing means for the filter element 115 are not realized by the filter element itself, but rather are provided, for example, by adhesion by the dimensioning of the receiving section 134 of the housing 116.

A variant of the receiving device 114 with a filter element is shown in the following FIG. 11. In this case, a compressible in its length filter element 115 is arranged in a receiving device 116, which is shown in cross section. The filter element is made of a fluid, for example, air-permeable filter material, and has multiple transverse folds 103, which are executed for example perpendicular to the axis of symmetry S '. For the sake of simplicity, it is also assumed in the description of FIG. 11 that the cross-section of the filter element 115 is substantially circular. The housing or the receiving device 116 is arranged concentrically around the axis of symmetry S 'and the filter element 115. The diameter D or the cross section of the filter element 115 corresponds to that of an insertion opening 117 of the housing 116. Thus, the filter element 115 can be inserted through the insertion opening 117 into the interior 137 of the housing 116, the insertion opening 117 facing the housing 116 like a funnel in the direction of the axis of symmetry S 'tapers and forms a stop 118 on which the end of the filter element 115 rests or abuts. The funnel-shaped tapered housing wall 119 also serves to guide the filter element 115. Both in the region of the insertion opening 117 and the tapered region 19, the folds or folding edges 120 can rest against the respective housing wall 117, 119. In the intermediate region 121, the housing has a larger diameter than the filter element 115 and serves to receive the clean air RE 'from the filter element 115. Raw air RO' flows through the insertion opening 117 and an opening 129 of the filter element 115 into the interior 122 and flows through the filter material, such as filter fleece, as shown by the solid arrows L '. The tapering wall 119 may be designed to be permeable to air, for example, so that clean air RE 'exits the housing 116 on the right side shown in FIG. The filter assembly of housing 116 and filter element 115 can be made compact tubular and is easily used in existing air guide tubes.

In the insertion opening 117, for example circumferential projections 123 are arranged, which fix at least the position of a folding of the filter element 115. These fixing elements 123 are substantially the distance between two, in Figure 11 with 124, 125 designated folding edges fixed. Due to the incoming air, which stops, for example, either by the stop 118 or a degree of the tubular or tubular filter element in the direction of the stop 118, creates an overpressure in the interior 122 of the filter element with respect to the gap of the housing 137, which in principle the Folds 103 are expanded in their distance from each other.

Due to the resulting air flow, a first region 126 of the filter element, in which the folds are compressed particularly tight, another portion 128 of the filter element 115, in which tightly packed folds are provided, for example, as a depot and a portion 127 of the filter element 115 between the two particularly compressed areas of folds 126, 128 through which flows the largest volume of air to be filtered. Through the areas 126, 128 is little or no volume flow of air. The filter element is thus partially flowed through radially. With the fixing means for the fold edges 124, 125 of the filter element designed as projections in the insertion opening, the filter housing 116 has the particular advantage that filter folds are pushed in the direction of the stop 118 out of the depot area 128 into the flow area 121 of the housing 16.

It can further be arranged in the insertion region 128 of the housing 116 or by a corresponding configuration of the projections 123 that increases with increasing loading of the filter element 115 in the flow area 127, the flow resistance for the air to be flowed through L 'and a force in the direction of Stop 118 is exercised. Thus, the fixing means 123 can be designed such that, depending on the force due to the flow resistance, which in turn depends on the loading of particles to be filtered, tightly folded folds are drawn from the depot area 128 of the filter element 115 into the flow area 127. This ensures that there is always as little as possible laden or partially loaded filter material in the throughflow region 127. The pleat spacing in the funnel-shaped region 126 present through the tapering wall 119 is in each case the smallest. By means of the depot, that is to say a kind of store of clean, non-charged filter material in the vicinity of the filling section, the change interval, ie the period in which the filter element 115 usually has to be exchanged, can be considerably extended with the same dimensions.

FIG. 12 shows a detailed view of a closed end section 110 of an embodiment of a filter element 101. The ends of the tubular filter element 101 are compressed and glued together. The sealing can be ensured, for example, a corresponding adhesive or plastic foam 140. Depending on the geometry of the folds 103 and folding sections can be brought one above the other and, for example, adhesively connected to each other. A sealing End plate, as shown for example in the figure 8 or 9, not necessary in this embodiment.

FIG. 13 also shows a possibility for fluid-tight sealing of an end section 134 of a filter element 101. The illustration in FIG. 13 corresponds to a detail of FIG. 10. The filter element is arranged in a housing 116 and the termination of the end of the filter element 101 which is distal to the inflow opening (not shown) is realized by a part 135 of the housing wall. The edge 130 of the end portion 134 is fixedly connected to the housing wall 135 by an adhesive 140, for example, and seals the interior of the filter element 101. The adhesive or the sealing compound 140 may also be applied over the entire cross section of the housing wall portion 135, as indicated by the dotted line.

Although the present invention has been explained in more detail with reference to preferred embodiments, it is not limited thereto, but variously modifiable. Other than the illustrated geometries for filter elements may be selected. The circumstances when installing the filter can be taken into account. The materials mentioned for the filter element or the housing are also only to be understood as examples. In addition to the illustrated application as an air filter for internal combustion engines, or for filtering the intake air, the proposed filter elements, receptacles and filter assemblies can also be used elsewhere. In particular, the substantially radial flow direction opposite to the examples may follow.

Claims

claims

1 . Filter element (1), in particular air filter for a motor vehicle, having an interior space (2) which has a circumference (U) and a longitudinal extent (L), the interior space (2) being of a fluid-permeable manner along the longitudinal extent (L) Filter material along the circumference (U) is enclosed, and wherein at least one selection of folding edges (3) of the longitudinal folds (18) by means of the folding edges (3) fixing means (4) are fixed relative to each other.

2. Filter element (1) according to claim 1, wherein a distance between fold edges (3) of the longitudinal folds (18) from the opening portion (6) to the end portion (7) decreases.

3. receiving device (10) for a filter element (1), which has an interior space (2) with a circumference (U) and a longitudinal extent (L), wherein the interior (2) of a substantially along the longitudinal extent (L) folded longitudinally fluid-permeable filter material along the circumference (U) is enclosed, wherein the receiving device (11) encloses the filter element (1) and fixing means (12, 13, 15, 16, 17), which at least a selection of folding edges (3) of the longitudinal folds ( 18) fixed relative to each other.

4. receiving device (1 1) according to claim 3, wherein the fixing means (12, 13, 15, 16, 17) are designed in the manner of guide rails such that outer fold edges (3) of the longitudinal folds (18) along the longitudinal extent (L ) are insertable on an inner side of the receiving device (1 1).

5. receiving device (1 1) according to claim 4, wherein a width (B) for introducing the folded edges (3) of the guide rails (13) from an insertion opening (19) of the receiving device (11) in the direction of the longitudinal extent (L) tapers.

6. receiving device (11) according to claims 3, wherein the fixing means (12, 13, 15, 16, 17) as pins, pins, projections and / or in the form of the folding profile for supporting the longitudinal folds (18) are formed.

7. Filter assembly (10) with a receiving device (11) according to any one of claims 3-6 and a filter element (1) with an interior (2) having a circumference (U) and a Length expansion (L), wherein the inner space (2) of a substantially along the longitudinal extent (L) longitudinally folded fluid-permeable filter material along the circumference (U) is enclosed.

8. Filter assembly (10) according to claim 7, wherein the receiving device (1 1) and the filter element (1) are arranged substantially concentric.

9. Filter assembly (10) according to claim 7 or 8, wherein the filter element (1) is designed according to one of claims 1 or 2.

10. Filter element (101), in particular air filter for a motor vehicle, which has a cavity (122) with a longitudinal extent (106) and a transverse extent (D ') of a fluid-permeable filter material, wherein the filter element (101) by multiple transverse folds (103) the filter material is reversibly compressible and / or stretchable in at least the longitudinal extent (106), and the transverse folds (103) are formed at a non-vanishing angle to the longitudinal extension direction (106), and wherein fixing means (107) for fixing a distance between at least one Selection of folding edges (112) of the transverse fold (103) are provided.

1 1. Filter element (101) according to claim 10, wherein the cavity (122) has an opening (129) for the inflow and / or outflow of a fluid.

12. Filter element (101) according to any one of claims 10 or 11, wherein the filter element (101) is formed tubular, and a fluid flows through the filter material substantially radially.

13. Filter element (101) according to any one of claims 10 - 12, wherein the filter element (101) has an opening portion (109) with an opening (129) and one of the opening portion (109) along the longitudinal extent (106) distally arranged end portion (110 ) with a preferably fluid-tight closure (11), the closure (110) being formed by bonding (140) opposite filter material sections substantially perpendicular to the longitudinal extension of the filter element (101).

14. Filter element (101) according to any one of claims 10-13, wherein the filter element (101) is flexibly bendable.

15. receiving device (1 16) for a filter element (115), which has a cavity (122) with a longitudinal extent (106) and a transverse extent (D ') from a fluiddurchläsa- gene filter material, wherein the filter element (1 15) by multiple Transverse folds (103) of the filter material in at least the longitudinal extent (106) reversibly compressible and / or stretchable, with fixing means (123) for fixing a distance between at least one selection of folding edges (124, 125) of the transverse fold (103) of the filter element ( 115).

16. receiving device (116) according to claim 15, wherein the receiving device (116) has at least one portion (126) as a fixing, which has a cross section dimensioned such that a selection of folds of the filter element (115) by a bond between a wall (116). 1 19) of the portion of the receiving device and folding edges (120) of the filter element (1 15) are fixed.

17. receiving device (1 16) according to any one of claims 15 or 16, wherein the receiving device (116) has a receiving portion (119) into which an end portion of the filter element (115) with compressed transverse folds (103) can be introduced.

18. Filter arrangement (114) with a receiving device (116) according to any one of claims 15 - 17 and a filter element (115) which has a cavity (122) with a longitudinal extent (106) and a transverse extent (D ') of a fluid-permeable filter material in that the filter element (115) is reversibly compressible and / or stretchable by multiple transverse folds (103) of the filter material in at least the longitudinal extent (106).

19. The filter assembly (114) according to claim 18, wherein the filter element (101) is tubular with a longitudinal axis (S) and a cross section (D) is formed, and the receiving means (116) surrounds the filter element substantially concentric, wherein the receiving device (1 16) has a plurality of sections (134, 136) with different cross sections.

20. A filter assembly (114) according to claim 19, wherein an end portion (134) of the filter element (101) with a wall (135) of the receiving device (1 16) is connected such that a fluid-tight closure of the end portion (135) through the wall ( 135).

21. A filter assembly (114) according to any one of claims 18-20, wherein the filter element (101) is formed according to any one of claims 10-13.