Air filter comprising a filter element which can be inserted radially into a housing having a filter positioning device

Abstract

The invention relates to an air filter comprising an annular filter element. The filter element can be inserted transversely to its longitudinal axis into a housing. The housing has at least one projection which secures an axial position of the filter element in the installed state. For this purpose, the projection radially overlaps a securing portion of the filter element. The projection can engage in an expanded fold of the filter element. Advantageously, a first projection is formed on a housing pot and a second projection is formed on an installation cover. Alternatively, the projection can be formed on the installation cover, in particular wherein the filter element can be pre-positioned opposite the projection by engaging in a depression in the housing. The installation cover is used to close a housing-pot installation opening, through which the filter element can be inserted.

Description

[0001] Air filter with a filter element that can be inserted radially into a housing with a filter positioning device.

[0002] This patent application claims priority over German patent application DE102024130506.1, which was filed with the German Patent and Trade Mark Office on October 21, 2024, the contents of which are hereby incorporated by reference.

[0003] Technical field

[0004] The invention relates to an air filter with a housing and a filter element, wherein the housing has a housing pot through which flow can be directed from a first axial end to a second axial end, with a lateral mounting opening for the filter element and a mounting cover for closing the mounting opening, and wherein the filter element has a support structure on an end face with a circumferential sealing section for sealing contact with a sealing surface of the housing.

[0005] State of the art

[0006] Such an air filter is known from US 2019 / 0224605 A1. In this air filter, a filter body is held on a filter frame. Ribs extend laterally from the filter frame next to the filter body. Sliding plates are arranged on a housing housing, which interact with the ribs of the filter frame. Additional sliding plates are provided on a lid for the housing housing, which interact with further ribs of the filter frame, also arranged laterally next to the filter body. By contacting the ribs with the sliding plates, the filter body can be aligned within the housing housing. During operation, air flows through the filter body in an axial direction from an inlet to an outlet.

[0007] Another air filter with an axially flowing filter element that can be inserted laterally into a housing is known from US 2007 / 0289265 A1. This filter element has adjacent tubes extending axially, each alternately closed at one end and the other, so that the airflow must pass through the filter medium walls between adjacent tubes. Such filter elements can be obtained by winding corrugated filter medium.

[0008] Air filters of the type described above are used, for example, to filter the intake air for combustion engines in commercial vehicles. Particularly with axial airflow across the filter element, the inlet area can become clogged relatively quickly in practice, thus reducing the filter's performance.

[0009] It is an object of the invention to provide a compact air filter whose filter element has a reasonable service life even under high dust loads and which can be replaced easily and safely.

[0010] Disclosure of the invention

[0011] This problem is solved by an air filter according to claim 1 and a filter element according to claim 21. Preferred embodiments are specified in the respective dependent claims and the description. According to the invention, an air filter is provided. The air filter can be used, for example, to filter combustion air for internal combustion engines, particularly those of commercial vehicles such as trucks, construction machinery, tractors, and the like.

[0012] The air filter consists of a housing and a filter element. The filter element is replaceable and can be arranged within the housing for operation of the air filter. After a certain period of operation, the filter element can be removed from the housing and replaced or, if necessary, cleaned.

[0013] The housing features a housing pot through which flow can be directed from a first axial end to a second axial end, and has a lateral mounting opening for the filter element. The housing also includes a mounting cover for closing the mounting opening.

[0014] The ends opposite each other in the axial direction serve as the inlet for air to be filtered and as the outlet for filtered air from the housing. A primary flow direction thus runs along a longitudinal axis of the housing. However, the flow through the filter element generally also has a radial component. Inlet and outlet connections for connecting the housing to other components can be located on the housing.

[0015] The mounting opening is located between the two axial ends of the housing. With the mounting cover removed, the filter element can be inserted into or removed from the filter housing through this opening. The filter element can also be pushed through the mounting opening between the two axial ends of the housing to separate a raw side from a clean side. During operation, the mounting cover closes the mounting opening.

[0016] The filter element has a support structure on one (axial) end face, with a circumferential sealing section for sealing against a sealing surface of the housing. The support structure can mechanically stabilize a filter medium body of the filter element. The sealing section of the support structure serves to seal the filter element against the housing. The sealing section can project axially. The sealing surface and the sealing section can advantageously be oriented for a radial seal. Alternatively, the sealing surface and the sealing section can be oriented for an axial seal. The sealing surface can be formed on the housing pot or, advantageously, on an outlet cover of the housing. In particular, a radial sealing surface can surround an outlet opening of the housing pot.

[0017] A seal with a sealing section can be integrally formed with a support body of the support structure, for example, by foaming or casting. The seal can, for example, be made of polyurethane foam. The seal can connect the support body to the filter medium body. Alternatively or additionally, the filter medium body can be bonded to the support body and / or held to it by force and / or form-fitting. According to the invention, the filter element has at least one filter medium body made of pleated filter medium, which surrounds a longitudinal axis in an annular manner. In other words, the filter element comprises at least one bellows. Folded edges generally extend with one component along the longitudinal axis. The filter medium body is closed in an annular shape (in the circumferential direction). Flow through the filter medium body typically occurs substantially in a radial direction.The circumferential surfaces of such an annular filter medium body are generally larger than its axial end faces. Folding the filter medium further increases the flow-through area of ​​the filter medium body. This increases the dust holding capacity of the filter element.

[0018] The filter medium body can have a cross-sectional shape, for example round or oval. Other cross-sectional shapes are also conceivable, such as designs that taper in a radial direction.

[0019] The ring-shaped design of the filter element and the side mounting opening on the housing allow for a compact air filter design. Air ducts at the axial ends of the housing do not need to be removed to replace the filter element. In particular, the air filter does not need to be accessible axially for filter element replacement. It is sufficient for the air filter to be accessible from the side of the mounting opening.

[0020] For the purposes of describing the present invention, directional terms such as radial or axial refer to the longitudinal axis of the filter element, unless otherwise specified. In the assembled state, the longitudinal axis of the filter element corresponds to a longitudinal axis of the housing.

[0021] According to the invention, a pleat spreading is formed on the filter medium body. In the area of ​​the pleat spreading, the distance (measured in the circumferential direction) between two adjacent folded edges of the filter medium, which define the spread pleat, is greater than the distance between two folded edges defining an unspread pleat next to the pleat spreading. The pleat spreading is generally provided on the outer circumference of the filter medium body.

[0022] The housing pot or mounting cover has an inwardly projecting retaining element which, when the filter element is mounted, overlaps a securing section of the support structure in a radial direction (with respect to the longitudinal axis) and engages in the pleat spreader. The retaining element can be designed as an inwardly projecting projection on a wall of the housing pot or mounting cover. If the retaining element is located on the housing pot, it is typically positioned opposite the mounting opening.

[0023] The overlap of the retaining element with the securing section of the support structure ensures axial positioning of the filter element within the housing. This advantageously ensures that, in the assembled state, the sealing section of the filter element rests against the sealing surface of the housing. The engagement of the retaining element with the spread fold of the filter medium body allows its radial extension—and thus its effective filter area—to be maximized within the limits defined by the housing. Simultaneously, a rotational alignment of the filter element within the housing can be defined. This is advantageous for ensuring the correct seating of the filter element within the housing. Furthermore, assembly is simplified, as less attention needs to be paid to the axial and rotational alignment of the filter element.As long as the retaining element engages with the pleat spreading, which can be achieved or at least simplified by a corresponding design of the housing pot or mounting cover and the filter element, the retaining element can guide and / or hold the filter element in a target position during assembly, at least in the area of ​​the retaining element.

[0024] Furthermore, the retaining element prevents unsuitable filter elements from being installed – accidentally or intentionally – without a suitably sized securing section on the support structure or without proper pleating in the appropriate location. This improves operational reliability and prevents damage to downstream components, such as an internal combustion engine, caused by insufficiently filtered air.

[0025] An engagement section of the support structure can engage with the pleat spread. This prevents the spread pleat from closing. Furthermore, the filter medium can be protected from damage during assembly. The engagement section can have a wedge-shaped cross-section. Advantageously, the engagement section is open radially outwards to allow the engagement of the retaining element.

[0026] The retaining element, when assembled, can engage within the engagement section of the pleat. This engagement section generally has a greater stiffness than the filter medium, thus enabling particularly precise alignment of the filter element. Furthermore, the engagement section of the support structure protects the spread pleat from mechanical damage.

[0027] The support structure can include a cage to support the filter medium body and a sealing element on which the sealing section is formed. A multi-part design of the support structure allows for the selection of different materials suitable for the sealing section and the cage, each with regard to its respective function.

[0028] The cage can be formed integrally with the locking section and / or the engagement section. This can increase the rigidity of the connection between these components. This allows for particularly precise alignment of the filter element within the housing. Furthermore, a one-piece design can offer manufacturing advantages.

[0029] The retaining element can have an inclined surface and a holding surface. The holding surface typically extends radially. The inclined surface is inclined relative to both the radial direction and the longitudinal axis. When the filter element is inserted into the housing pot (if the retaining element is formed on the housing pot) or when the mounting cover is closed (if the retaining element is formed on the mounting cover), the locking section can slide off the inclined surface. This aligns the filter element axially, particularly pressing it towards the sealing surface. In the assembled state, the locking section of the filter element's support structure can rest against the holding surface of the retaining element. The axial position of the filter element, especially with the sealing section resting against the sealing surface, is thus secured.

[0030] The housing may have an outlet cover with an air outlet. The outlet cover is attached to the housing shell on the outlet side. The air outlet may, for example, be designed as an outlet nozzle for connecting a clean air line. The sealing surface of the housing may be formed on the outlet cover.

[0031] Alternatively, the air outlet can be located directly on the housing. The air outlet can be located on an end face of the housing. The sealing surface can be located on the end face.

[0032] The sealing surface can face radially inwards. In the assembled state, the sealing section thus rests against the sealing surface in a radially sealing direction. This can increase the positional tolerances required for the filter element within the housing to ensure a reliable seal.

[0033] Alternatively, the sealing surface can point axially along the longitudinal axis. In the assembled state, the sealing section thus rests against the sealing surface in an axially sealing manner. This allows for a particularly reliable seal when the retaining element is integrated into the mounting cover.

[0034] The retaining element can project radially inwards beyond the sealing surface, particularly the sealing surface that points radially inwards or axially. This can be advantageous with regard to space utilization. To achieve the overlap with the retaining element, the securing section does not need to project radially outwards beyond the filter medium body and / or the sealing section, or only to a limited extent.

[0035] Particularly when the retaining section is formed on the housing housing, the mounting cover can have an inwardly projecting fixing element for contact with the support structure of the filter element. Typically, in the assembled state, the fixing element overlaps another securing section of the filter element in a radial direction. In this way, the filter element can also be aligned relative to the housing in the area of ​​the mounting opening and secured in the operating position. In particular, the fixing element and the retaining element together ensure that, in the assembled state, the sealing section of the filter element rests fully against the sealing surface of the housing.

[0036] The additional securing section can project radially outwards beyond the filter medium body. The additional securing section can be integral with the cage of the support structure.

[0037] The fixing element can have an additional inclined surface and a further retaining surface. The further retaining surface typically extends radially. This additional inclined surface is inclined relative to both the radial direction and the longitudinal axis. When the mounting cover is closed, the additional securing section can slide down this inclined surface. This aligns the filter element axially, pressing it particularly towards the sealing surface. In the assembled state (with the mounting cover closed and the filter element inserted), the additional securing section of the filter element's support structure rests against the further retaining surface. The axial position of the filter element, especially with the sealing section resting against the sealing surface, is thus secured.

[0038] The mounting cover can be detachably attached to the housing. This allows the mounting cover to be removed from the housing for replacing the filter element, thus improving access to the mounting opening.

[0039] In particular, the mounting cover can be arranged on the housing in two configurations rotated 180° relative to each other to close the mounting opening. Similarly, one or more sealing elements can be arranged on either side of the mounting opening. Depending on the installation situation, components obstructing access may be present to varying degrees on both sides of the mounting opening in the vicinity of the air filter. If the mounting cover, and possibly a sealing element, can be selectively arranged on either side of the mounting opening, the air filter can be adapted to installations with varying space constraints without any design modifications.

[0040] A hinge can be provided for pivoting the mounting cover relative to the housing. A pivotable mounting of the cover to the housing is particularly advantageous when the cover is used to align the filter element. Specifically, when closing the cover, the retaining element can be brought into radial overlap with the remaining securing section of the filter element. This pivoting motion can facilitate the application of force to tightly seat the sealing section against the sealing surface.

[0041] The hinge can be designed with tabs and hooks that can engage with each other. When mounted, the hooks can engage in recesses in the tabs. Tabs with recesses can be formed, in particular, on the housing cup. The hooks can be formed on the mounting cover. This design allows for a simple yet secure and detachable fastening of the mounting cover to the housing cup. If—with a mirror-symmetrical design of the mounting opening—tabs for hook engagement are arranged on two opposite sides of the mounting opening, the mounting cover can be mounted in two different orientations. Depending on requirements, the hooks can be engaged in the tabs on one side or the other.

[0042] At least one lug can be provided to support the mounting cover axially against the housing pot, particularly on the side of the mounting cover opposite the hinge. This allows the mounting cover to be supported axially against the housing pot. This is particularly advantageous if the mounting cover has a fixing element for aligning the filter element. The lug can, in particular, bear against a tab that is not used for engaging a hook in the selected orientation of the mounting cover.

[0043] The mounting cover can have at least one blade that can be inserted between a guide rib in the housing pot and the support structure, in particular to press the sealing section against the sealing surface. In this way, a sealing connection, especially axially, can be established when the mounting cover is closed. The blade can extend transversely to the longitudinal axis and, in the inserted state, be arranged against a circumferential wall of the housing pot. Advantageously, two blades are provided on opposite sides. This allows for a particularly uniform pressing of the sealing section against the sealing surface.

[0044] The sword can have at least one inclined plane oriented obliquely to the longitudinal axis and at least one clamping surface oriented perpendicular to the longitudinal axis. The support structure can have at least one corresponding clamping surface and, advantageously, at least one corresponding inclined plane. The guide web can have a guide surface extending in a straight line and, in particular, perpendicular to the longitudinal axis for the engagement of the sword (on its side facing away from the inclined plane and clamping surface). Alternatively, the guide web can have at least one corresponding inclined plane and at least one corresponding clamping surface. In this case, the support structure can have a guide surface extending in a straight line and, in particular, perpendicular to the longitudinal axis for the engagement of the sword (on its side facing away from the inclined plane and clamping surface).As the sword and support structure slide against each other along the inclined surfaces, the filter element can be positioned axially within the housing pot when the mounting cover is closed. The axial position of the filter element is secured by the clamping surface against the corresponding clamping surface, ensuring a tight seal between the sealing section and the sealing surface.

[0045] The housing pot can have a receiving groove for an end section of the support structure, particularly opposite the mounting opening. When the filter element is inserted into the housing pot, the end section of the support structure engages with the receiving groove. This pre-positions the filter element. The receiving groove can widen towards the mounting opening. This facilitates the insertion of the filter element into the housing pot and the insertion of the support structure into the receiving groove. For final positioning, the filter element can be aligned, for example, using the at least one blade.

[0046] The filter element can be designed as a single bellows with exactly one annular filter medium body. One axial end of the single bellows is typically sealed by a closed end disc. The other axial end is typically provided with an open end disc.

[0047] Alternatively, the filter element can have a first filter medium body and a second filter medium body, with the second filter medium body arranged inside the first. The second filter medium body, like the first, can also be designed as a bellows made of pleated filter medium. Advantageously, the two filter medium bodies are designed to allow fluid flow parallel to each other. This further increases the effective filter area and the dust holding capacity of the filter element. The pleats are generally located in the first, outer filter medium body.

[0048] A gap, widening in the axial direction, can be provided between the two filter media bodies. The two filter media bodies can be enclosed at a first axial end by a common, open end plate, which seals the gap between the filter media bodies. At the second axial end, an open end plate can be provided on the first, outer filter media body. The second, inner filter media body can be provided with a closed end plate at its second axial end. Alternatively, a plug can seal the interior enclosed by the inner filter media body in the axial direction at the second axial end.

[0049] The air filter may also include a secondary filter element located on the clean side of the main filter element. This secondary filter element prevents dirt from entering the outlet when the main filter element is removed for replacement. In particular, the housing can be cleaned, for example, by blowing it out, with the secondary filter element preventing dirt from entering downstream components on the clean side. Even if the main filter element is damaged, the secondary filter element prevents dirt from entering downstream components. The secondary filter element can span the outlet-side axial end of the housing. The secondary filter element can be designed as a flat filter element, especially with a pleated filter medium (as an additional bellows).

[0050] The housing may have an inlet cover with an air intake. The inlet cover is attached to the housing shell on the intake side. The air intake can be designed, for example, as an inlet nozzle for connecting a raw air line or as an inlet opening open to the environment.

[0051] The air filter may also include a pre-filter unit, in particular with at least one cyclone unit. The pre-filter unit allows coarse dust to be separated before it reaches the (main) filter element. This extends the service life of the filter element. The pre-filter unit may be integrated into or housed within the inlet cover. The inlet cover may also have a suction port for the pre-filter unit.

[0052] The present invention further encompasses a filter element for an air filter according to the invention as described above. The filter element has a support structure on an (axial) end face, with a circumferential sealing section for sealing contact with a sealing surface of the housing. The sealing section may project axially from the support structure. A seal with the sealing section may be integrally formed with a support body of the support structure, for example, by foaming or casting. The filter element comprises at least one filter medium body made of pleated filter medium, which surrounds a longitudinal axis in an annular manner. Folded edges generally extend with one component along the longitudinal axis. The filter medium body is closed in an annular shape. A pleat spreading is formed on the filter medium body. The pleat spreading is generally provided on the outer circumference of the filter medium body.In the area of ​​the pleat spread, a locking section is formed on the support structure. The locking section serves to align the filter element in a housing pot by bringing a retaining element of the housing pot or a mounting cover into radial overlap with the locking section and into engagement with the pleat spread.

[0053] An engagement section of the support structure can engage with the pleat spread. The support structure can include a cage for supporting the filter medium body and a sealing element on which the sealing section is formed. The cage can be formed integrally with the securing section and / or the engagement section.

[0054] The filter element may have an additional securing section on the support structure. This additional securing section may project radially outwards beyond the filter medium body. The additional securing section may be integral with the cage of the support structure. The additional securing section may be radially overlapped with a fixing element of a mounting cover to further define the position of the filter element within the housing pot (in addition to the securing section that interacts with the retaining section of the housing pot).

[0055] Alternatively or additionally, an end section of the support structure can protrude beyond the outer surface of the filter medium body. This end section can engage with a receiving groove in the housing pot to pre-position the filter element within the housing pot.

[0056] The support structure can have at least one inclined surface and at least one clamping surface facing away from the sealing section. In particular, if the mounting cover has at least one correspondingly shaped blade, the filter element can be brought into an operating position by sliding the inclined surfaces against each other and held in the operating position by the clamping surfaces pressing against each other.

[0057] The filter element can be designed as a single bellows with exactly one ring-shaped filter medium body.

[0058] Alternatively, the filter element can comprise a first filter medium body and a second filter medium body, with the second filter medium body arranged within the first filter medium body. The second filter medium body, like the first, can also be designed as a bellows made of pleated filter medium. The pleats are generally located in the first, outer filter medium body. Advantageously, the two filter medium bodies are designed to allow fluid flow parallel to each other. A gap, particularly one widening in an axial direction, can be provided between the two filter medium bodies. The two filter medium bodies can be enclosed at a first axial end by a common, open end plate, which seals the gap between the filter medium bodies. An open end plate can also be provided at the second axial end of the first, outer filter medium body.The second, inner filter medium body can be provided with a closed end plate at its second axial end. Alternatively, a plug can seal the interior enclosed by the inner filter medium body in the axial direction at the second axial end.

[0059] Brief description of the drawings

[0060] Further features and advantages of the invention will become apparent from the following detailed description of exemplary embodiments of the invention, from the claims, and from the figures in the drawing, which illustrate details of the invention. The aforementioned and further described features can be implemented individually or in any suitable combination in variants of the invention. The features shown in the drawing are presented in such a way that the special features of the invention are clearly visible. The drawing shows:

[0061] Fig. 1 shows an air filter according to the invention during the assembly of a filter element according to the invention through a lateral mounting opening of a filter housing, in a schematic, partially cut-away side view;

[0062] Fig. 2 shows a housing pot of the filter housing of the air filter of Figure 1, in a schematic perspective view;

[0063] Fig. 3 shows the filter element of the air filter of Figure 1, in a schematic longitudinal section;

[0064] Fig. 4 shows the filter element of Figure 3, in a schematic perspective view;

[0065] Fig. 5 shows the air filter of Figure 1 with the filter element inserted further, in a schematic, partially cutaway side view;

[0066] Fig. 6 shows the air filter of Figure 1, wherein the filter element is fully inserted in the radial direction but still tilted in the filter housing, in a schematic, partially cut-away side view;

[0067] Fig. 7 shows the air filter of Figure 1 with the filter element in the operating position, in a schematic, partially cutaway side view;

[0068] Fig. 8 shows the air filter of Figure 1 with the filter element in the operating position, with an open mounting cover arranged at the mounting opening, in a schematic, partially cut-away side view;

[0069] Fig. 9 shows the air filter of Figure 1 in an operational configuration with the mounting cover closed, in a schematic, partially cut-away side view;

[0070] Fig. 10 shows the air filter in the configuration of Figure 8 with the mounting cover open, in a schematic perspective view;

[0071] Fig. 11 shows the filter housing of the air filter of Figure 1, wherein the mounting cover is arranged in a reversed orientation on the housing pot compared to the configuration of Figure 10, in a schematic perspective view;

[0072] Fig. 12 shows another air filter according to the invention with another filter element according to the invention during the attachment of a mounting cover, in a schematic, partially cutaway side view; Fig. 13 shows the air filter of Figure 12 with the mounting cover completely closed, in a schematic, partially cutaway side view;

[0073] Fig. 14 shows the mounting cover of the air filter of Figure 12 in a schematic perspective view; Fig. 15 shows the air filter of Figure 12 with the mounting cover completely closed, in a schematic perspective view with a housing wall shown partially cut away; Fig. 16 shows the filter element of the air filter of Figure 12 in a schematic longitudinal section.

[0074] Embodiments of the invention

[0075] Figure 1 shows an air filter 10, while a filter element 12 is inserted radially 14 through a lateral mounting opening 16 into a housing pot 18 of a housing 20. The housing pot 18 shown in Figure 2 has, in addition to the mounting opening 16, two openings 24, 26 opposite each other along a longitudinal axis 21 at its axial ends, through which air to be filtered flows into the housing pot 18 during operation, and filtered air flows out of the housing pot 18. The longitudinal axis 21 shown in Figure 2 corresponds to a longitudinal axis 22 of the filter element 12 arranged in the housing pot 18 in its operating position.

[0076] An inlet cover 28 is arranged at the first opening 24 of the housing pot 18, as shown in Figure 1. In the illustrated embodiment, the inlet cover 28 has an inlet opening 30 open to the environment. A pre-filter unit 32, here with several cyclone units, is housed within the inlet cover 28 (symbolically indicated by a dashed outline in Figure 1). A discharge port 34, here in the form of a suction connection, on the inlet cover 28 allows for the extraction of coarse dirt separated before the pre-filter unit 32. A dust discharge valve can be connected to the discharge port 34 instead of a suction port.

[0077] An outlet cover 36 is arranged at the second opening 26 of the housing pot 18. The outlet cover 36 has an outlet nozzle 38 for connecting a clean air line (not shown in detail).

[0078] In the area of ​​the second opening 26, a secondary filter element 40 is arranged in the illustrated embodiment. The secondary filter element 40 is designed as a flat filter element which can comprise pleated filter medium.

[0079] The (main) filter element 12 is shown in isolation in Figures 3 and 4. The filter element 12 has at least one (first) filter medium body 42, which is designed as a bellows made of folded filter medium. The filter medium body 42 surrounds the longitudinal axis 22 in a closed ring. In the illustrated embodiment, a second filter medium body 44 is provided within the first filter medium body 42, which is also designed as a bellows made of folded filter medium and surrounds the longitudinal axis 22 in a closed ring.

[0080] The two filter medium bodies 42, 44 are fluidically connected in parallel. A gap 46 is formed between the two filter medium bodies 42, 44, which widens along the longitudinal axis 22. An open end plate 48 is arranged at an inlet-side axial end of the filter element 12, sealing the folds of the two filter medium bodies 42, 44 and the gap 46 at their end faces. At the outlet-side axial end of the filter element 12, the folds of the first filter medium body 42 are sealed at their end faces by an open end plate 50. The interior space within the second filter medium body 44 is closed at the outlet-side axial end by a plug 52. The folds of the second filter medium body 44 can be sealed at the outlet-side end face by adhesive beads (not shown in detail).The flow pattern that develops during operation through the two filter medium bodies 42, 44 of the filter element 12 is schematically indicated by an arrow 54 in Figure 3. While the filter medium bodies 42, 44 are flowed through essentially in a radial direction to the longitudinal axis 22, the flow through the housing pot 18 occurs entirely in an axial direction.

[0081] The open end disc 50 on the first filter medium body 42 is part of a support structure 56, which, in addition to the end disc 50, includes a support body 58. The support body 58 can be a monolithic injection-molded plastic part. The support body 58 is embedded in the end disc 50. In this way, the two components (end disc 50 and support body 58), which in this embodiment form the support structure 56, are attached to one another. The embedding of the filter medium body 42 at its outlet-side end face in the end disc 50 results in the support structure 56 being attached to the filter medium body 42.

[0082] A section of the support body 58 forms a cage 60, which stabilizes the two filter medium bodies 42, 44 within the gap 46.

[0083] The support body 58 further comprises an engagement section 62, which engages in a radially outwardly open fold of the filter medium body 42 and spreads this fold out circumferentially. The filter medium body 42 thus has a folded spread 64. The engagement section 62 is designed here in the form of a radially outwardly open, V-shaped wedge.

[0084] Adjacent to the fold spreading, a securing section 66 is formed on the support structure 56, here on the support body 58. Opposite the longitudinal axis 22, another securing section 68 is provided on the support structure 56, again on the support body 58. The function of the securing sections 66 and 68 will be explained in more detail below.

[0085] The support structure 56 also has a sealing section 70, see in particular Figure 3. The sealing section 70 is formed on the end disk 50. Thus, the end disk 50 functions as a sealing element. The sealing section 70 can be designed with a radially acting sealing lip. In the assembled state, the sealing section 70 abuts a circumferential sealing surface 72 (see Figure 1) of the housing 20. The sealing surface 72 points radially inwards towards the longitudinal axis 22 for the radial contact of the sealing section 70. In the illustrated embodiment, the sealing surface 72 is formed on the outlet cover 36. How the sealing section 70 is brought into contact with the sealing surface 72 by means of the retaining sections 66, 68 during the assembly of the filter element 12 will be explained in more detail below.The housing pot 18 has an inwardly projecting retaining element 74 opposite the mounting opening 16, see Figures 1 and 2. The retaining element 74 is formed with an inclined surface 76 that is inclined relative to the longitudinal axis 22 and the radial direction 14 to the longitudinal axis 22. A retaining surface 78, extending radially outward and perpendicular to the longitudinal axis 22 in the radial direction 14, adjoins the inclined surface 76. The inclined surface 76 and the retaining surface 78 face the outlet-side opening 26 of the housing pot 18.

[0086] When the filter element 12 is inserted into the filter housing through the mounting opening 16 in the radial direction 14, the securing section 66 first meets the inclined surface 76, see Figure 5.

[0087] As the filter element 12 is further inserted, the locking section 66 slides down the inclined surface 76.

[0088] Finally, the locking section 66 and the retaining surface 78 overlap, as shown in Figure 6. The retaining element 74 now engages within the engagement section 62 of the support structure in the pleat spreader 64. As the locking section 66 slides on the inclined surface 76, the filter element 12 is moved axially towards the outlet cover 36 in a circumferential area adjacent to the pleat spreader 64. The sealing section 70 partially overlaps the sealing surface 72. In this state, the filter element 12 is slightly inclined relative to its operating position. However, further radial advancement of the filter element 12 from the configuration shown in Figure 6 is no longer possible.

[0089] To bring the filter element 12 into its operating position shown in Figure 7, it is tilted in the direction of arrow 80 (compare Figure 6). In the operating position, the sealing section 70 rests fully and tightly against the sealing surface 72.

[0090] Tilting the filter element 12 can, in principle, be done manually. However, a certain amount of force is required to bring the sealing section 70 fully into contact with the sealing surface 72.

[0091] To facilitate assembly and ensure that the operating position is set up, a fixing element 84 is provided on a mounting cover 82 for closing the mounting opening 16. The fixing element 84 projects radially inwards from the mounting cover 82 – similar to the retaining element 74 on the housing pot 18 – see Figures 8 and 9.

[0092] The fixing element 84 has a further inclined surface 86 and a further retaining surface 88. The inclined surface 86 on the fixing element is inclined relative to the radial direction 14 and the longitudinal axis 22. At least when the mounting cover 82 is closed (see Figure 9), the retaining surface 88 extends perpendicularly (radially) to the longitudinal axis 22 of the filter element 12 in its operating position. The inclined surface 86 and the retaining surface 88, at least when the mounting cover 82 is closed, face the outlet-side opening 26 of the housing pot 18. When the mounting cover 82 is closed, its inclined surface 86 abuts the further securing section 68 of the filter element 12, provided that the filter element 12 is not yet in its operating position, but rather tilted, as shown in Figure 6.As the mounting cover 82 is further closed, the filter element 12 is pressed towards the outlet cover 36 by the wedge action of the inclined surface 86 in the circumferential area adjacent to the further locking section 68; this occurs through a pivoting movement of the filter element 12 in the direction of arrow 80 in Figure 6. Due to the overlap of the retaining element 74 with the locking section 66 (compare Figures 6 and 7), a support is formed on the side of the filter element 12 facing away from the mounting cover 82, which acts as a pivot point for the pivoting movement of the filter element 12. At the same time, the contact of the locking section 66 with the retaining surface 78 ensures that the sealing section 70 remains in engagement with the sealing surface 72 in the circumferential area adjacent to the locking section 66.

[0093] As the mounting cover 82 is closed further, the sealing section 70 increasingly engages with the sealing surface 72 until, with the mounting cover 82 completely closed, the sealing section 70 is fully in contact with the sealing surface 82 (compare Figures 7 and 9).

[0094] When the mounting cover 82 is fully closed, its retaining surface 88 overlaps the further securing section 68 on the filter element 12. The axial position of the filter element 12 is then defined by the contact of the two retaining surfaces 76 and 86 with the two securing sections 66 and 68.

[0095] In the illustrated embodiment, the mounting cover 82 is pivotably mounted on the housing pot 18. Hooks 90 provided on the mounting cover engage in tabs 92 of the housing pot 18 to form a hinge 94 for this pivoting movement of the mounting cover 18, see in particular Figure 11.

[0096] The hooks 90 can be released from the tabs 92. The mounting cover 82 can thus be removed from the housing 20 for improved accessibility when replacing the filter element 12. Furthermore, tabs 92 are provided on both sides of the mounting opening 16 on the housing pot 18. The mounting cover 82 can therefore be hooked onto the housing 18 in two orientations rotated 180° relative to each other, with the hinge 94 positioned on one side or the other of the mounting opening, see Figures 10 and 11.

[0097] To fix the mounting cover 82 in the closed position, locking elements 96, here snap hooks, are provided, compare Figures 9 and 10. The snap hooks are attached to the mounting cover 82 and can be hooked between the tabs 92 on the housing pot 18.

[0098] In the illustrated embodiment, the mounting cover 82 is further provided with lugs 98 which, in the closed state, bear against those tabs 92 that are not part of the hinge 90 in the selected orientation of the mounting cover 82. The mounting cover 82 is thus supported axially on both sides of the mounting opening 16 against the housing pot 18: firstly, by the engagement of the hooks 90 with the tabs 92; secondly, by the contact of the lugs 98 with the other tabs 92. The filter element 12 can thus be reliably pressed into the operating position and held in the operating position by means of the fixing element 84 and the retaining element 74. Figure 12 shows another air filter 10. The differences from the first embodiment, shown in Figures 1 to 11, are explained below. For further details, please refer to the preceding description.

[0099] In the embodiment of Figure 12, an outlet nozzle 38 for filtered air is formed integrally with the housing pot 18.

[0100] A dust discharge valve 100 is connected to a discharge nozzle 34 of an inlet cover 28 with a pre-filter device 32.

[0101] As described above, the housing pot 18 has a lateral mounting opening 16 through which a filter element 12 can be inserted or removed. In the second embodiment of the air filter 10, a retaining section 66 of a support structure 56 of the filter element 12 is associated with a mounting cover 82. The mounting cover 82 has a radially inwardly projecting retaining element 74, which, when the mounting cover 82 is closed, comes into contact with the retaining section 66 and engages in a pleat 64 of the filter element 12 (see Figure 13). Here, too, an engagement section 62 of the support structure 56 engages in the pleat. The retaining element 74 of the mounting cover 82, in turn, engages in the engagement section 62 of the support structure 56.

[0102] The retaining element 74 is designed with an inclined surface 76 (see also Figure 14) which, when the mounting cover 82 is closed radially, deflects the filter element 12 axially. This allows a sealing section 70 of the support structure 56 to be pressed against a sealing surface 72 on the housing pot 18, see Figure 12 (before pressing) and Figure 13 (in the pressed state). An axial seal is thus provided.

[0103] To ensure a fully sealed system, in this embodiment of the air filter 10, two blades 102 are formed on the mounting cover 82. When the mounting cover 82 is closed, these blades are inserted between a guide web 104 of the housing top 18 and a section of the support structure 56 that projects beyond the outside of the filter medium body 42 (see Figure 15). In this embodiment, the guide web 104 has a guide surface 105 for the blade 102 that extends straight and orthogonally to the longitudinal axis 21 of the housing pot 18.

[0104] As can be seen particularly in Figure 14, the blades 120 each have two inclined surfaces 106 which, when the mounting cover is closed, interact with the support structure 56 to move the sealing section 70 of the filter element 12 towards the sealing surface 72 of the housing 20 and press it against it. The support structure has corresponding inclined surfaces 108 along which the blade can slide, see Figure 16. The operating position of the filter element 12 thus established is secured by the clamping surfaces 110 of the blades 102, which are oriented orthogonally to the longitudinal axis 22 of the filter element 12, against corresponding clamping surfaces 112 of the support structure 56. In this case, three clamping surfaces 110 and 112 are provided. In the operating position, the longitudinal axis 22 of the filter element is aligned parallel to the longitudinal axis 21 of the housing pot; in particular, the longitudinal axes 21, 22 can coincide (compare Figure 13).

[0105] For pre-positioning the filter element 12 when inserting it into the housing pot 18, an end section 114 of the support structure 56, projecting beyond the outside of the filter medium body 42, can engage in a receiving groove 116 in the housing pot 18, see Figure 15. The receiving groove 116 can widen towards the mounting opening 16. This engagement can act as a kind of hinge, allowing the filter element 12 to pivot towards the sealing surface 72 when the mounting cover 82 is attached. Alternatively or additionally, a translational movement of the filter element 12 along the longitudinal axes 21 / 22 towards the sealing surface 72 can be enabled. These pressing movements can be initiated by means of the blades 102, if these are provided. Alternatively or additionally, contact between the retaining element 74 and the locking section 66 causes movement of the filter element 12 against the sealing surface 72.

[0106] In summary, the invention relates to an air filter with an annular filter element. The filter element can be inserted into a housing transversely to its longitudinal axis. The housing has at least one projection which secures an axial position of the filter element in the assembled state. For this purpose, the projection overlaps a securing section of the filter element in the radial direction. The projection can engage in a spread fold of the filter element. Advantageously, a first projection is formed on a housing pot and a second projection is formed on a mounting cover. Alternatively, the projection can be formed on the mounting cover, in particular wherein the filter element can be pre-positioned opposite the projection by engaging in a recess in the housing. The mounting cover serves to close a mounting opening in the housing pot through which the filter element can be inserted. List of reference numerals

[0107] Air filter 10

[0108] Filter element 12

[0109] radial direction 14

[0110] Mounting opening 16

[0111] Housing pot 18

[0112] Case 20

[0113] Longitudinal axis 21 of the housing pot 18

[0114] Longitudinal axis 22 of the filter element 12

[0115] First opening 24

[0116] Second opening 26

[0117] Inlet cover 28

[0118] Entrance opening 30

[0119] Pre-filter unit 32

[0120] Discharge nozzle 34

[0121] Outlet cover 36

[0122] Outlet nozzle 38

[0123] Secondary filter element 40

[0124] first filter medium body 42

[0125] second filter medium body 44

[0126] Gap 46

[0127] open end disc 48

[0128] open end disc 50

[0129] Plug 52

[0130] Arrow 54

[0131] Support structure 56

[0132] Support body 58

[0133] Cage 60

[0134] Intervention section 62

[0135] Wrinkle spreading 64

[0136] Security section 66

[0137] further security section 68

[0138] Sealing section 70

[0139] Sealing surface 72

[0140] Retaining element 74

[0141] inclined surface 76 on the retaining element 74

[0142] Holding surface 78 on the holding element 74

[0143] Arrow direction 80

[0144] Mounting cover 82

[0145] Fixing element 84

[0146] further inclined surface 86 on the fixing element 84

[0147] further holding surface 88 on the fixing element 84

[0148] Hook 90

[0149] Tabs 92

[0150] Hinge 94

[0151] 96 locking elements

[0152] Noses 98

[0153] Dust discharge valve 100

[0154] Sword 102

[0155] Management bridge 104

[0156] Slanted 106 on the sword 102

[0157] Inclined 108 on the support structure 56

[0158] Clamping surface 110 on the sword 102

[0159] Clamping surfaces 112 on the support structure 56

[0160] End section 114 of the support structure 56

[0161] Recordings 116

Claims

Claims 1. Air filter (10) with a housing (20) and a filter element (12), wherein the housing (20) has a housing pot (18) through which flow can be directed from a first axial end to a second axial end, with a lateral mounting opening (16) for the filter element (12) and a mounting cover (82) for closing the mounting opening (16), wherein the filter element (12) has a support structure (56) on one end face with a circumferential sealing section (70) for sealing connection to a sealing surface (72) of the housing, wherein the filter element (12) has a filter medium body (42) made of folded filter medium which surrounds a longitudinal axis (22) in a ring shape, wherein a pleat spreading (64) is formed on the filter medium body (42), and wherein the housing pot (18) or the mounting cover (82) has an inwardly projecting retaining element (74) which, in the mounted state of the filter element (12), overlaps a securing section (66) of the support structure (56) in a radial direction (14) and engages in the pleat spreading (64).

2. Air filter (10) according to claim 1, wherein an engagement section (62) of the support structure (56) engages in the pleat spreading (64) and the retaining element (74) engages in the pleat spreading (64) within the engagement section (62) in the assembled state.

3. Air filter (10) according to claim 1 or 2, wherein the support structure (56) has a cage (60) for supporting the filter medium body (42) and a sealing element on which the sealing section (70) is formed.

4. Air filter (10) according to claim 3, wherein the cage (60) is formed integrally with the securing section (66) and / or the engagement section (62).

5. Air filter (10) according to one of the preceding claims, wherein the retaining element (74) has an inclined surface (76) and a retaining surface (78) against which, in the assembled state, the securing section (66) of the support structure (56) of the filter element (12) rests.

6. Air filter (10) according to one of the preceding claims, wherein the housing (20) has an outlet cover (36) with an air outlet, in particular wherein the sealing surface (72) of the housing (20) is formed on the outlet cover (36).

7. Air filter (10) according to one of the preceding claims, wherein the sealing surface (72) points radially inwards or in an axial direction along the longitudinal axis (22), in particular wherein the retaining element (74) projects radially inwards beyond the sealing surface (72).

8. Air filter (10) according to one of the preceding claims, wherein the mounting cover (82) has an inwardly projecting fixing element (84) for contact with the support structure (56) of the filter element (12).

9. Air filter (10) according to claim 8, wherein the fixing element (84) has a further inclined surface (86) and a further retaining surface (88) against which a further securing section (68) of the support structure (56) rests in the assembled state.

10. Air filter (10) according to one of the preceding claims, wherein the mounting cover (82) is detachably held on the housing pot (18), in particular wherein the mounting cover (82) can be arranged on the housing pot (18) in two configurations rotated 180° relative to each other in order to close the mounting opening (16).

11. Air filter (10) according to one of the preceding claims, wherein a hinge (94) is provided for pivoting the mounting cover (82) relative to the housing pot (18), in particular wherein the hinge (94) is designed with tabs (92) and hooks (90) which can be engaged with each other.

12. Air filter (10) according to one of the preceding claims, wherein at least one lug (98) is provided to support the mounting cover (82) axially on the housing pot (18), in particular on the side of the mounting cover (82) opposite the hinge (94).

13. Air filter (10) according to one of the preceding claims, wherein the mounting cover (82) has at least one sword (102) which can be inserted between a guide rib (104) in the housing pot (18) and the support structure (56), in particular to press the sealing section (70) against the sealing surface (72).

14. Air filter (10) according to claim 13, wherein the sword (102) has at least one inclined plane (106) oriented obliquely to the longitudinal axis (22) and at least one clamping surface (110) oriented orthogonally to the longitudinal axis (22) and wherein the support structure (56) has at least one corresponding clamping surface (112) and in particular a corresponding inclined plane (108).

15. Air filter (10) according to claim 13 or 14, wherein the guide rib (104) has a straight-extending guide surface for the placement of the sword (102).

16. Air filter (10) according to one of the preceding claims, wherein a receiving groove (116) for an end section of the support structure (56) is formed in the housing pot (18), in particular opposite the mounting opening (16), in particular wherein the receiving groove (116) widens towards the mounting opening.

17. Air filter (10) according to one of the preceding claims, wherein the filter element (12) has a first filter medium body (42) and a second filter medium body (44) which is arranged inside the first filter medium body (42), in particular wherein the two filter medium bodies (42, 44) are capable of being flowed through parallel to each other.

18. Air filter (10) according to one of the preceding claims, further comprising a secondary filter element (40) which is arranged on the clean side of the filter element (12).

19. Air filter (10) according to one of the preceding claims, wherein the housing (20) has an inlet cover (28) with an air inlet.

20. Air filter (10) according to one of the preceding claims, further comprising a pre-filter device (32), in particular with a cyclone unit.

21. Filter element (12) for an air filter (10) according to one of the preceding claims.

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