Filtration elements and filtration systems

Abstract

The present invention relates to a filtration element (10) for filtering fluids, particularly air, comprising at least one filter bellows (12) including a zigzag-folded filter medium (13) having an untreated inlet face (50) and a clean outlet face (52), the filter bellows (12) being mounted on a reinforcing frame (18), the filtration element (10) comprising at least one seal (20), and a plurality of elongated adhesive strips (28) arranged along at least two adhesive tracks (26) on the inlet face (50) and / or outlet face (52) of the filter bellows (12). According to the present invention, the filtration element (10) also comprises strain relief means (38) for compensating for changes in length of the adhesive tracks (26) relative to the filter medium (13) and / or the seal (20). The present invention also relates to a filtration system (100) including the filtration element (10).

Description

[Technical field]

[0001] The present invention relates to a filtering element for filtering fluids, in particular to be used as an air filter or interior air filter of a motor vehicle, in particular of an internal combustion engine, and to a filtering system comprising a filtering element. [Background technology]

[0002] WO 2017 / 133796 discloses a filter element, in particular for a gas, in particular for air, in particular for a motor vehicle and / or machine, in particular for an internal combustion engine. The filter element can be installed in a filter housing of the filter in an installation direction extending parallel or coaxially to an installation axis. The filter element comprises at least one filter bellows comprising at least one filter medium. The filter bellows has a fluid flow passage side on both axial sides with respect to an element axis extending perpendicularly or transversely to the installation axis. The filter element comprises at least one seal arranged at least partially continuously in the circumferential direction on at least a part of the radially outer side of the filter element with respect to the element axis. Summary of the Invention [Problem to be solved by the invention]

[0003] The present invention aims to provide an improved filter element for filtering fluids, which is highly reliable in operation and exhibits a long service life.

[0004] It is a further object of the present invention to provide a filtration system for filtering a fluid that contains such a replaceable filtration element. [Means for solving the problem]

[0005] According to one aspect of the invention, the above-mentioned object is solved by a filter element for filtering fluids, in particular air, which comprises at least one filter bellows with a zigzag-folded filter medium having a raw inlet face and a clean outlet face. The filter bellows is arranged, preferably connected, in a frame, in particular a reinforcing frame, in particular connected to the frame at the raw inlet face and / or the clean outlet face. The inlet face or outlet face of the filter bellows is provided with at least one seal arranged at least partially continuously in the circumferential direction on at least a part of the outer peripheral side of the filter medium. The seal is preferably connected to the frame, in particular by a form-fitting element, preferably by an at least partially circumferentially extending mating rib or mating opening in the reinforcing frame, in particular by casting, foaming or molding. Also, on the inlet face and / or outlet face of the filter bellows, a plurality of elongated adhesive portions are arranged along at least two adhesive tracks on the filter medium. The filtration element is also characterized by a strain relief means for compensating for changes in the length of the adhesive track on the filter media and / or seal. Typically, the adhesive used is a thermoplastic hot melt, preferably polyamide or polyester, which is applied in a plastic state by an applicator nozzle and hardens on cooling, i.e. the hardened adhesive becomes a bead of resin.

[0006] According to a further aspect of the invention, a further object is solved by a filtration system for filtering a fluid, comprising a filter housing having at least one inlet for introducing a fluid flow and at least one outlet for discharging a purified fluid flow, and a filter element for filtering a fluid, which is exchangeably arranged in the filter housing between the raw side and the clean side. The filter element comprises at least one filter bellows comprising a zigzag folded filter medium having a raw side inlet face and a clean side outlet face. The filter bellows is arranged in a reinforcing frame arranged on the clean side. The inlet or outlet face of the filter bellows is provided with at least one seal arranged in a circumferential direction at least partially continuous on at least a part of the outer peripheral side of the filter medium. The seal is connected to the reinforcing frame by a mating rib extending at least partially in the circumferential direction, in particular by casting or molding. Also, on the inlet and / or outlet face of the filter bellows, a plurality of elongated adhesive portions are arranged along at least two adhesive tracks on the filter medium. The filtration element also features strain relief means to compensate for changes in adhesive track length for the filter media and / or seal.

[0007] Preferred embodiments and advantages of the invention can be obtained from the accompanying claims, the description and the drawings.

[0008] The proposed filter element for filtering fluids, in particular air, comprises at least one filter bellows with a zigzag-folded filter medium having an untreated inlet face and a clean outlet face. The filter bellows is arranged on a reinforcing frame, and at least one seal is provided at the inlet or outlet face of the filter bellows, which is arranged at least partially continuously in the circumferential direction on at least a part of the outer circumferential side of the filter medium. The seal is connected to the reinforcing frame, for example, by an at least partially circumferentially extending mating rib, in particular by foaming or molding. Also, at the inlet and / or outlet face of the filter bellows, a plurality of elongated adhesive portions are arranged on the filter medium along at least two adhesive tracks.

[0009] According to the invention, the filtering element is provided with strain relief means to compensate for changes in length of the adhesive track relative to the filter media and / or seal.

[0010] The filter bellows is folded, for example, in a zigzag manner, with parallel folded edges arranged one after the other in the longitudinal direction of the filter bellows and respectively extending between both end faces of the filter bellows, whereby a continuous reinforcing frame may be moulded onto the outer periphery of the filter bellows. Such filter bellows are advantageously used, for example, as air filters for internal combustion engines and represent an inexpensive and efficient solution for air filtering. The moulded frame allows the filter bellows to be easily mounted and, if necessary, replaced.

[0011] The seal is preferably a polyurethane (PUR) seal that is produced by foaming or molding onto the filter bellows in the area of ​​the reinforcing frame.

[0012] In a flat filter, the flow direction is, for example, perpendicular to the inlet and outlet faces which in the case of a flat filter are provided on both flat sides of the filter bellows. Preferably, the outlet and inlet faces of the filter on which the folds are provided form the faces on which the fold ends of the filter medium folds are respectively arranged.

[0013] One flow channel side of the filter bellows may define a fluid inlet face and the other flow channel side may define a fluid outlet face, the fluid flowing through the filter bellows from the inlet face to the outlet face, each flow channel side may be realized as a flow channel side, and in the case of a folded filter bellows, each folded edge defines a corresponding flow channel side.

[0014] According to the prior art, the adhesives arranged on the end faces are usually arranged on the fold ends of the filter medium across the inflow or outflow faces as adhesive tracks that run continuously across the fold ends. This ensures that the fold ends are clearly positioned at a fixed distance from each other. The adhesive tracks are applied across the fold ends either on the inflow or outflow faces formed by the adjacent fold ends or on the paper that is not yet folded and is to be creased in the adhesive plastic state, so that in the region of the inflow or outflow fold ends the adhesives of the adjacent folds join with each other, so that at the inflow and / or outflow faces a continuous, relatively strain-resistant connection is formed that runs across the fold ends. In both cases, a continuous, high-strength bead is formed that runs across the folds. The strain relief means of the present invention advantageously prevents the adhesive tracks from causing tensile stresses across the fold ends of the filter bellows due to the shrinkage of the adhesive over time. The advantage of this strain relief means is that it reduces or prevents deformations caused by the shrinkage of the adhesive. Such deformation can change the position of, or in extreme cases cause damage to, functional elements such as sealing surfaces, etc. However, the strain relief allows the adhesive to shrink without causing adverse stress effects in these areas.

[0015] Advantageously, the filter element is a so-called flat filter element. A flat filter element in the sense of the present invention is one in which the filter medium is not closed so as to form a hollow body.

[0016] The filter element of the invention is not annular. The flow channel sides are arranged on both axial sides with respect to the element axis. In contrast, in the case of hollow filter elements, in particular so-called circular filter elements, the filter medium is closed in the circumferential direction and surrounds the inside. The filter element of the invention can be planar or curved. In this regard, the inlet and / or outlet faces of the filter bellows for the fluid can be planar, curved or stepped. The filter element can also be box-shaped. The filter bellows can be approximately polyhedral in shape. Advantageously, the filter bellows is cubic, rectangular, pyramidal, prismatic, wedge-shaped, etc. It should be noted that all faces of the filter bellows, in particular the faces on the circumferential sides, do not have to be planar. At least one face of the filter bellows can extend at least partially curved, in particular parabolically and / or stepped. The faces arranged on the opposite sides can extend parallel to one another. Alternatively or additionally, the faces can extend obliquely or otherwise non-parallel to one another. Advantageously, the inflow surface and / or the outflow surface may extend at least partly perpendicularly or obliquely, respectively, to the element axis.

[0017] Advantageously, the inflow and outflow faces may extend at least partially obliquely and / or at least partially parallel to one another. Advantageously, the at least one filter bellows may comprise a zigzag and / or wavy filter medium, which allows an extension of the surface of the filter medium through which the fluid flows in relation to the spatial extension of the filter bellows.

[0018] Advantageously, the folded edges of the filter medium run parallel to one another on both flow channel sides, in particular on the inflow face and / or on the outflow face.

[0019] Advantageously, at least one filter bellows has relatively deep folds and / or a variable fold height. The extent of the folds of the folded filter medium between an inlet fold edge and an adjacent outlet fold edge is referred to as the "fold height". In the case of deep folds, the fold height, i.e. the height of the filter bellows in the area of ​​the corresponding fold, is greater than the width and / or length of the filter bellows perpendicular to or transverse to the fold height.

[0020] The filter medium may comprise filter paper, filter nonwoven, meltblown, fabric, and / or another filter medium suitable for filtering fluids, especially air. Advantageously, the filter medium is flexible, especially foldable or bendable.

[0021] Alternatively or additionally, the filter bellows may comprise a fluid-permeable, in particular air-permeable, foam filter.

[0022] The filter bellows can be realized at least partially as a mass of filter material, in particular a foam filter.

[0023] According to an advantageous embodiment, at least one adhesive portion and at least one non-adhesive portion are provided as strain relief means on each glue track, in particular the non-adhesive portions of adjacent glue tracks being arranged at different fold edges, in particular in the cross-fold direction. In this way, a continuous glue track is divided into individual adhesive portions separated from one another. These non-adhesive portions can be conveniently introduced in the production of the glue tracks by interrupting the glue flow. Preferably, the non-adhesive portions are arranged at the fold edges.

[0024] According to an advantageous embodiment, the non-glued portions of adjacent glue tracks are arranged without overlapping in the cross-fold direction, in other words adjacent glue tracks preferably do not include a non-glued portion on the same fold edge. This offset arrangement of the non-glued portions relative to one another on the inflow or outflow face has a relatively small effect on the overall stiffness of the filter bellows, which remains stable even at higher fluid pressures.

[0025] According to an advantageous embodiment, the continuous adhesive portion extends over at least 5 times the fold as the non-adhesive portion, preferably at least 10 times, particularly preferably at least 15 times, such a dimensioning of the adhesive portion relative to the non-adhesive portion ensures sufficient stability of the filter bellows during practical operation while at the same time providing sufficient strain relief.

[0026] According to an advantageous embodiment, the non-glued section extends over at least or exactly one fold edge, preferably over at least or exactly two adjacent fold edges. Preferably, a continuous glued section adjoins each of a number or all of the non-glued sections on both sides, unless it ends at the last fold of the filter bellows, and extends over at least five fold edges or over at least five times, preferably at least ten times, particularly preferably at least fifteen times the fold edges of the non-glued section. This ensures sufficient stability of the filter bellows against high fluid pressures due to flow through the filter medium.

[0027] According to an advantageous embodiment, the adhesive tracks are arranged parallel and equidistant to one another and / or the non-glued parts are arranged uniformly distributed over the inflow and / or outflow faces, such an arrangement of the adhesive tracks and the dimensions of the adhesive parts relative to the non-glued parts ensures sufficient stability of the filter bellows during practical operation while at the same time providing sufficient strain relief when fluid flows through the filter medium.

[0028] According to an advantageous embodiment, the adhesive tracks run perpendicular to the folded edge, which provides beneficial stability of the filter medium against higher fluid pressures, even when the load on the filter medium increases due to the accumulation of dirt particles filtered from the fluid.

[0029] According to an advantageous embodiment, a sliding sheet of seal is provided as a strain relief means on at least one longitudinal and / or transverse side of the stiffening frame, the longitudinal and / or transverse side being oblique or perpendicular to the adhesive track. Such a sliding sheet of seal allows the seal to move with the movement of the filter bellows caused by the contraction of the adhesive track, and prevents the formation of undesirable adhesive openings between the filter medium and the seal, which could be a leak point for the filtered fluid. Thus, the tightness of the seal between the filter medium and the seal can be ensured over the service life of the filtering element. Such a sliding sheet of seal is preferably arranged on at least one surface parallel to the folded edge of the stiffening frame, in particular on two surfaces parallel to the folded edge.

[0030] According to an advantageous embodiment, the stiffening frame comprises a number of openings or ribs, for example form-fitting means such as interlocking ribs. Preferably, at least one longitudinal side or one transverse side of the stiffening frame is designed without form-fitting or interlocking ribs. The seal is preferably sealingly connected to the filter bellows and / or to the stiffening frame surrounding the filter bellows, and is preferably fixedly connected to the stiffening frame by form-fitting means such as interlocking ribs formed, for example foamed or molded, thereon, more preferably formed by foaming or molding. The absence of interlocking ribs on at least one longitudinal side or transverse side of the stiffening frame results in a sliding seat of the seal, which allows it to move easily since it simply rests on the smooth front surface of the stiffening frame.

[0031] According to an advantageous embodiment, the seal is slidably arranged on the longitudinal or transverse sides. Due to the absence of form-fitting elements such as mating ribs, on these sides the seal is weakly connected to the reinforcing frame without form-fitting or mating, especially across the folded edge, and can therefore move together with the filter bellows when the latter moves due to the contraction of the adhesive track. This makes it possible to prevent the occurrence of unexpected adhesive openings between the filter medium and the seal, which could become leak points for the filtered fluid.

[0032] According to a further aspect, the invention relates to a filtration system for filtering a fluid, comprising a filter housing having at least one inlet for introducing a fluid flow and at least one outlet for discharging a purified fluid flow, and a filter element for filtering the fluid, which is exchangeably arranged in the filter housing between the raw side and the clean side. The filter element comprises at least one filter bellows comprising a zigzag folded filter medium, having a raw inlet surface formed by the raw folded edge and a clean outlet surface formed by the clean folded edge. The filter bellows is arranged on a clean reinforcement frame. The inlet or outlet surface of the filter bellows is provided with at least one seal arranged in a circumferential direction at least partially continuous on at least a part of the outer peripheral side of the filter medium. The seal is connected to the reinforcement frame by a mating rib extending at least partially in the circumferential direction, in particular by casting or molding. Also, on the inlet and / or outlet surface of the filter bellows, a plurality of elongated adhesive portions are arranged on the filter medium along at least two adhesive tracks.

[0033] According to the invention, the filtering element is provided with strain relief means to compensate for changes in length of the adhesive track relative to the filter media and / or seal.

[0034] The filter bellows is folded, for example, in a zigzag manner, with parallel folded edges arranged one after the other in the longitudinal direction of the filter bellows and respectively extending between both end faces of the filter bellows, whereby a continuous reinforcing frame may be moulded onto the outer periphery of the filter bellows. Such filter bellows are advantageously used, for example, as air filters for internal combustion engines and represent an inexpensive and efficient solution for air filtering. The moulded frame allows the filter bellows to be easily mounted and, if necessary, replaced.

[0035] The seal is preferably a polyurethane (PUR) seal that is produced by foaming or molding onto the filter bellows in the area of ​​the reinforcing frame.

[0036] In a flat filter, the flow direction is, for example, perpendicular to the inlet and outlet faces which in the case of a flat filter are provided on both flat sides of the filter bellows. Preferably, the outlet and inlet faces of the filter on which the folds are provided form the faces on which the fold ends of the filter medium folds are respectively arranged.

[0037] One flow channel side of the filter bellows may define a fluid inlet face and the other flow channel side may define a fluid outlet face, the fluid flowing through the filter bellows from the inlet face to the outlet face, each flow channel side may be realized as a flow channel side, and in the case of a folded filter bellows, each folded edge defines a corresponding flow channel side.

[0038] According to the prior art, the adhesives that are usually arranged on the end faces are arranged as adhesive tracks that extend continuously over the inlet or outlet face on the folded edges of the folds of the filter medium. The strain relief means of the present invention advantageously prevent the adhesive tracks from shrinking over time, which would cause adhesive openings between the filter medium and the seal that could provide a leak point for the filtered fluid. The advantage of the strain relief means is that the adhesive shrinkage does not cause a relatively wide peeling effect in the critical connection areas of the filter bellows to the seal. The adhesive shrinkage can still occur so that no corresponding distortion occurs in these areas.

[0039] According to an advantageous embodiment, a cyclone pre-separator is provided in the filter housing upstream in the fluid flow direction from the filtering element and / or a safety element is provided downstream in the fluid flow direction from the filtering element.

[0040] Advantageously, the filter is configured as a multi-stage filter, in particular as a two-stage compact air filter. Advantageously, the at least one filtering element is arranged downstream in the flow direction of the at least one particle separator, in particular a cyclone pre-separator. The at least one particle separator may be part of the filter or may be connected externally upstream of the filter and may in particular be used as a pre-separator. The external pre-separator may be arranged outside the motor room. Advantageously, the at least one inlet, the at least one outlet and any particle separator are arranged substantially in a straight line. This allows the fluid to flow through the filter, in particular substantially along the housing axis of the filter housing.

[0041] According to an advantageous embodiment, when the filtration element is properly installed, a seal in the filtration element separates the raw side from the clean side, thereby ensuring reliable purification of the incoming fluid over a long service life of the filtration element.

[0042] According to an advantageous embodiment, the filter element is designed as a slide-in filter element which is or can be inserted into the filter housing in a direction transverse to the main flow axis of the fluid, which allows a timely replacement of the loaded filter element and also allows the duration of maintenance intervals involving shutdown of the internal combustion engine or motor vehicle to be reduced.

[0043] The described filtration system can be advantageously used as an air filter, in particular as an air filter or interior air filter, in particular in motor vehicles, in particular in internal combustion engines.

[0044] The invention can be used in motor vehicles, construction / agricultural machines, compressors, industrial motors or other devices equipped with an internal combustion engine. Vehicles in the sense of the invention include land vehicles, marine vehicles and / or aircraft.

[0045] Advantageously, the motor vehicle is a car, a truck, a motorcycle, a bus, a tractor, an agricultural vehicle and / or a construction vehicle, or the like.

[0046] The invention may advantageously be part of the intake manifold of an internal combustion engine. The filter serves to purify the combustion air supplied to the internal combustion engine. However, the invention is not limited to air filters for intake manifolds of internal combustion engines of motor vehicles. Instead, it may also be used in the air systems of motor vehicles or other machines, in particular agricultural or construction machines. Air filters may also be used outside automotive technology, in particular industrial motors, etc.

[0047] Otherwise, the features and advantages disclosed in connection with the inventive filtering element, the inventive element frame, the inventive filter bellows, the inventive filter housing and the inventive filter, as well as the advantageous embodiments thereof, apply mutually to one another and vice versa. Of course, individual features and advantages can be mutually combined with one another, in which case further advantageous effects may arise that exceed the sum of the individual effects.

[0048] Further advantages are obtained from the following description of the drawings, in which embodiments of the invention are shown. The drawings, the description and the claims contain a number of features in combination, which the person skilled in the art can consider and combine as appropriate and individually to provide further combinations. [Brief description of the drawings]

[0049] [Figure 1] FIG. 1 is an isometric view of a filtration system equipped with a filtration element according to an embodiment of the present invention. [Diagram 2] FIG. 2 is an isometric longitudinal section of the filtration system of FIG. 1. [Diagram 3] FIG. 2 is an isometric view of a filtration element according to an embodiment of the present invention. [Figure 4] FIG. 4 is a plan view of the outflow face of the filtration element of FIG. 3. [Diagram 5] 5 is an enlarged plan view of the outflow surface of the filtration element of FIG. 4. [Figure 6] 13 is an isometric view of a filtration element according to a further embodiment of the present invention. [Figure 7] FIG. 7 is an isometric view of a stiffening frame with a seal support device for the filtration element of FIG. [Figure 8] FIG. 7 is an enlarged isometric view of the filtration element of FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0050] In the figures, identical or similar components are indicated with the same reference symbols.The figures are merely illustrative and should not be understood as limiting.

[0051] FIG 1 is an isometric view of a filtration system 100 for filtering a fluid, having a filtration element 10 installed therein, according to an embodiment of the present invention. For better understanding, FIG 2 shows an isometric view of filtration system 100 in longitudinal cross section.

[0052] Filtration system 100 comprises a filter housing 110 having at least one inlet 102 (not visible) for introducing a fluid flow 120 and at least one outlet 104 for discharging a purified fluid flow 122. Filter housing 110 includes a housing lower portion 114 and a housing upper portion 112 joined along a flange 130 by a threaded connection 132. A filtration element 10 for filtering a fluid is replaceably disposed in filter housing 110 between untreated side 40 and clean side 42. Filter element 10 can be attached to and detached from filter housing 110 via a housing cover 116, which can be sealingly connected to filter housing 110 by clamp closure 118. The inflow and outflow directions of the fluid to be purified are indicated by arrows 120, 122.

[0053] In the longitudinal section of the filtration system 100 in Fig. 2, the filtration element 10, also sectioned, is shown, which is inserted into a filter housing 110. Furthermore, a cyclone pre-separator 14 is shown, which filters out coarse dirt particles from the fluid flow. The separated dirt particles can be discharged from the filter housing through a dirt outlet 106. The flow direction 134 of the filtration element 10 is indicated by an arrow. On the downstream side, the purified fluid flows through a safety element 16, which is configured for example as a flat bellows, in order to protect the clean side 42, also during replacement of the filtration element 10, from contamination by the inflow of unpurified fluid and other dirt particles, before being discharged from the filter housing 110 through the outlet 104. The outlet 104 is completely covered by the safety element 16.

[0054] The filtration element 10 inserted into the filtration system 100 shown in Figures 1 and 2 is shown in an isometric view in Figure 3. The filtration element 10 comprises a filter bellows 12 that is inserted into an element frame 36.

[0055] Filter element 10 is designed as a slide-in filter element that is inserted or insertable into filter housing 110 in a direction transverse to a primary fluid flow axis 128 (see FIG. 2).

[0056] The filter bellows 12 comprises a filter medium 13 folded in a zigzag pattern. When viewed along a major axis 62, the filter bellows 12 is rectangular. When viewed along a transverse axis 64, the filter bellows 12 is generally trapezoidal. The untreated inlet face 50 of the filter bellows 12 extends parallel to the flow central plane, i.e. perpendicular to the major axis 62. The clean outlet face 52 extends parallel to the transverse axis 64 and inclined to the flow central plane, i.e. inclined to the inlet face 50.

[0057] The filter bellows 12 tapers towards its front lateral side when viewed in the installation direction 66. At the inlet and outlet faces 50, 52, the folded ends 24 of the filter medium 13 extend parallel to the lateral axis 64, respectively. The folded ends 24 are across the inlet face 50 or the outlet face 52, respectively. The height of the folds 22 of the folded filter medium 13 in the direction along the main axis 62 decreases from the rear lateral side to the front lateral side of the filter bellows 12 with respect to the installation direction 66. Thus, the filter bellows 12 has a variable folded height.

[0058] Outlet face 52 is surrounded by seal 20. When filtration element 10 is properly installed, seal 20 of filtration element 10 separates untreated side 40 from clean side 42.

[0059] The seal 20 is made of polyurethane. It has elasticity. The seal 20 is foamed onto the end face of the filter medium 13. The seal 20 protrudes axially and radially outward from the filter medium 13 with respect to the main axis 62. The outlet seal lip of the seal 20 at the end face forms a circumferentially continuous seal surface 44 with respect to the main axis 62. The seal surface 44 is located on the housing side seal surface in the installed state.

[0060] On the rear side of the seal 20, axially opposite the seal surface 44 with respect to the axis 62, a reinforcing frame 18 made of a resin material is embedded in the seal track of the seal 20. 18 The back surface of the seal 20, which is axially opposite the seal surface 44 with respect to the axis 62, extends in a plane parallel to the seal surface 44. The stiffening frame 18 is circumferentially continuous about the axis 62. The back surface of the seal 20, which is axially opposite the seal surface 44 with respect to the axis 62, extends in a plane parallel to the seal surface 44. 10 When installed, the seal face 44 and the seal back face each extend parallel to the housing side seal surface.

[0061] At the outflow face 52, the element frame 36 is provided with a seal support device 34. The seal support device 34 is arranged at the outflow edge of the element frame 36. The seal support device 34 extends continuously in the circumferential direction on the outside of the filter element 10 with respect to the main axis 62. The seal support device 34 is connected and integral with the longitudinal side walls 46 and the lateral side walls 48 of the element frame 36.

[0062] To mechanically stabilize the folds 22 of the filter medium 13 against the fluid pressure of the fluid, a plurality of elongated adhesive portions 28 are disposed on the filter medium 13 along at least two adhesive tracks 26 on the inlet face 50 and / or outlet face 52 (not visible) of the filter bellows 12.

[0063] In FIG. 3 and subsequent figures, for simplicity, only one of the adhesive tracks 26 is labeled with a reference symbol.

[0064] To compensate for changes in length of adhesive track 26 relative to filter media 13 and / or seal 20, filtration element 10 includes strain relief means 38 according to the present invention.

[0065] In this regard, FIG. 4 shows a plan view of the outlet flow surface 52 of the filtration element 10 of FIG. 3, and FIG. 5 shows an enlarged plan view of the outlet flow surface 52. As shown in FIG.

[0066] In a first embodiment shown in Figures 3 to 5, at least one adhesive portion 28 and at least one non-adhesive portion 30 are provided as strain relief means 38 on each adhesive track 26, in particular the non-adhesive portions 30 of adjacent adhesive tracks 26 are positioned at different fold edges 24 in a direction crossing the fold line 22.

[0067] As shown in particular in Figure 5, the non-glued portions 30 of adjacent adhesive tracks 26 are arranged without overlapping in the direction transverse to the fold line 22. Advantageously, the continuous adhesive portion 28 extends across the fold line 22 at least 5 times, preferably at least 10 times, particularly preferably at least 15 times, the non-glued portion 30. The non-glued portion 30 extends across the fold edge 24, preferably across the fold line 22.

[0068] The adhesive tracks 26 are arranged parallel to each other and equidistant from each other. 24 The non-bonded portions 30 are uniformly distributed across the outflow surface 52.

[0069] FIG. 6 shows an isometric view of a filter element 10 according to a further embodiment of the invention, in which, as strain relief means 38, a sliding seat of seal 20 is provided on at least one lateral side 60 of the reinforcing frame 18 perpendicular to the adhesive track 26. The seal 20 is partially sectioned and shown only on one side of the outflow face 52 of the filter element 10. Here, in the reinforcing frame 18 including the interlocking ribs 32, the lateral sides 60 of the reinforcing frame 18 are designed without interlocking ribs. Since the seal 20 is not fixedly connected to the interlocking ribs 32, i.e. by foaming, on these lateral sides 60, the seal 20 is slidably arranged on the lateral sides 60 and can slide on the reinforcing frame 18. This allows the seal 20 to move in the event of a movement of the filter medium 13 due to the shrinkage of the adhesive track 26, Reinforcement 1 and 2. The filter media 13 and seal 20 can move relative to the lateral sides 60 of the frame 18, thereby preventing the formation of adhesive openings between the filter media 13 and the seal 20 that could provide a leak point for filtered fluid, thereby ensuring a tight seal between the filter media 13 and the seal 20 over the life of the filtration element 10.

[0070] In this regard, Figure 7 shows an isometric view of the stiffening frame 18 supported on the seal support device 34 of the filtration element 10. As shown, the lateral sides 60 of the stiffening frame 18 do not have mating ribs 32 so that the seal 20 of the filter bellows 12 can move thereon.

[0071] Figure 8 is an enlarged isometric view of the filtration element 10 of Figure 6. Here, the seal 20 is shown only on one side of the outflow face 52 of the filtration element 10, partially sectioned to reveal the lateral side 60 of the stiffening frame 18 without the mating ribs 32.

[0072] In another embodiment, the strain relief 38 may be provided without a mating rib 32 on at least one longitudinal side 58 that is inclined or perpendicular to the adhesive track 26 .

Claims

1. A filtration element (10) for filtering a fluid, comprising: At least one filter bellows (12) including a zigzag folded filter medium (13) having an untreated inlet face (50) and a clean outlet face (52), The filter bellows (12) is disposed in a reinforcing frame (18); The filtering element (10) comprises at least one seal (20) arranged circumferentially at least partially in a continuous manner on at least a portion of the outer periphery of the filter medium (13) at the inlet face (50) and / or the outlet face (52) of the filter bellows (12), the seal (20) is connected to the stiffening frame (18) by a mating rib (32) extending at least partially circumferentially of the stiffening frame (18) and is connected to the stiffening frame (18) by casting, foaming or molding; At the inlet face (50) and / or the outlet face (52) of the filter bellows (12), a plurality of elongated adhesive portions (28) are arranged along at least two adhesive tracks (26) on the filter medium (13); The filtration element (10) is characterized in that it comprises a strain relief means (38) for compensating for changes in length of the adhesive track (26) relative to the filter medium (13) and / or the seal (20).

2. 2. The filtration element of claim 1, wherein the filter bellows (12) is connected to the stiffening frame (18) at the untreated inlet face (50) and / or at the clean outlet face (52).

3. 3. The filtering element according to claim 1 or 2, wherein the seal (20) is sealingly connected to the filter bellows (12) by casting, foaming or molding.

4. The filter material (13) has a plurality of folding portions (22) folded in a zigzag shape and a plurality of folding ends (24) which are the folded portions of each of the plurality of folding portions (22), 4. The filtration element of claim 1, wherein the strain relief means (38) on each adhesive track (26) comprises at least one adhesive portion (28) and at least one non-adhesive portion (30), the non-adhesive portions (30) of adjacent adhesive tracks (26) being located at different fold ends (24) in a direction transverse to the fold (22).

5. 5. The filtration element of claim 4, wherein the non-adhesive portions (30) of adjacent adhesive tracks (26) are disposed without overlapping transversely to the folds (22).

6. 6. The filtration element of claim 4 or 5, wherein the bonded portion (28) extends over at least five times as many of the folds (22) as the non-bonded portion (30).

7. The filtration element according to any one of claims 4 to 6, wherein the non-bonded portion (30) extends across the folded edge (24).

8. 8. A filtration element according to any one of claims 4 to 7, wherein the adhesive tracks (26) are arranged parallel and equidistant to one another and / or the non-glued portions (30) are arranged uniformly distributed over the inflow face (50) and / or the outflow face (52).

9. The filtration element according to any one of the preceding claims, wherein the adhesive tracks (26) extend perpendicular to the fold edge (24).

10. A filtration system (100) for filtering a fluid, comprising: a filter housing (110) having at least one inlet (102) for introducing a fluid stream (120) and at least one outlet (104) for discharging a purified fluid stream (122); A filtering element (10) according to any one of claims 1 to 9 for filtering a fluid, The filtration system, wherein the filtration element (10) is replaceably disposed in the filter housing (110) between an untreated side (40) and a clean side (42).

11. 11. The filtration system of claim 10, further comprising a cyclone pre-separator (14) disposed within the filter housing (110) upstream of the filtration element (10) in a fluid flow direction and / or a flat bellows (16) disposed downstream of the filtration element (10) in a fluid flow direction.

12. When the filtration element (10) is properly installed, a seal (20) of the filtration element (10) separates the untreated side (40) from the clean side (42).

12. The filtration system according to claim 10 or 11.

13. The filtration system according to any one of claims 10 to 12, wherein the filtration element (10) is designed as a slide-in filtration element inserted or insertable into the filter housing (110) in a direction transverse to a main flow axis (128) of the fluid.

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