DE102016002954B4 - Filter system and filter element for a filter system - Google Patents

Abstract

A filter element (10) comprising a closed filter body (12) elongated along a longitudinal axis (L) and a closed end plate (20) firmly connected thereto, to which the filter body (12) is tightly connected with its end face (50), wherein the end plate (20) has a fixing position (32) for an axially outwardly projecting support structure (40), wherein the fixing position (32) is arranged in a bulge (30) of the end plate (20) and the fixing position (32) is arranged outwardly with respect to a radial position within an outer skin of the filter body (12) and axially in front of the end face (50) of the filter body (12), and the bulge (30) extends a space defined by an inner side of the filter body (12), wherein the bulge (30) has through openings (34) in the axial direction.

Description

Technical field

The invention relates to a filter system, in particular for use as an air filter of an internal combustion engine, and a filter element for installation in such a filter system.

State of the art

From the WO 2009/047196 A1 A filter system for internal combustion engines with a filter element is known. This filter system is used in particular for filtering the intake air of an internal combustion engine and consists of a housing and a cover for accommodating the filter element. The design of the filter element seals, with two annular bead-shaped arrangements and a sealing groove located between them, ensures that both a sealing effect and axial support of the filter element in a housing are achieved. Especially when using plastic for sealing elements subject to vibration, a design is required that operates reliably even under extreme temperature fluctuations.

From the DE 20 2013 011 841 U1 A filter system for filtering a fluid is known, comprising a filter element, a filter housing with a cover, a sealing device arranged on the filter element for separating a raw side of the filter system from a clean side, a coupling device consisting of at least two coupling parts for coupling the filter element to the cover, wherein the coupling parts comprise a coupling element and a coupling receptacle, wherein the coupling device is a quick-coupling device and the sealing device is arranged in its sealing position in an end position of the coupled coupling element and coupling receptacle.

Air filter filter elements are generally designed to be replaced after a certain period of operation. Depending on the amount of dust, the service life of an air filter can range from a few days (construction machinery) to several months. The secondary filter element, located on the clean air side, usually remains in the filter system. However, if the secondary filter element is also heavily contaminated, it must also be replaced, as otherwise the air throughput will be reduced excessively. The reliable and process-safe sealing of the filter element and secondary filter element in a housing is particularly important to protect the intake tract of a downstream internal combustion engine from penetrating dirt.

Depending on the intended use of the filter system, it may be advantageous to provide only a primary filter element or an additional secondary filter element.

Disclosure of the invention

An object of the invention is to provide a filter element which can be used in a filter system optionally with or without a secondary filter element, which allows a reliable seal between the area of the unfiltered and the area of the filtered medium and enables a stable installation position in a housing of a filter system.

A further object of the invention is to provide a filter system with such a filter element.

The above objects are achieved according to one aspect of the invention in a filter element and according to another aspect in a filter system with a replaceable filter element, in which the filter body is tightly connected with its end face to a particularly closed end plate, wherein the end plate has a fixing position for an axially outwardly projecting support structure, wherein the fixing position is arranged in a bulge of the end plate and the fixing position is arranged with respect to a radial position within an outer side of the filter body and axially outwardly in front of the end face of the filter body and wherein the bulge extends a space defined by an inner side of the filter body.

Advantageous embodiments and advantages of the invention emerge from the further claims, the description and the drawings.

A filter element is proposed, comprising a filter body which is elongated along a longitudinal axis and closed in the form of a ring, and a closed end plate which is firmly connected thereto and to which the filter body is tightly connected with its end face, wherein the end plate has a fixing position for an axially outwardly projecting support structure, wherein the fixing position is arranged in a bulge of the end plate and the fixing position is arranged with respect to a radial position within an outer skin of the filter body and axially outwardly in front of the end face of the filter body, and wherein the bulge extends a space defined by an inner side of the filter body.

Because the space defined by the inner side of the filter body is extended by the bulge, the thus extended space extends beyond the front side of the filter body of the filter element and preferably beyond the outer edge of the end plate. This allows for a longer secondary element and/or creates the space required for a handle located on the secondary element.

The end plate can advantageously support both the sealing function of the filter body and a support function by axially clamping the filter element in a housing using the support structure. The support structure allows for secure force transmission from a housing cover into the end plate. The spatially separated sealing and support areas enable a flexible, space-optimized filter element design.

Due to the arrangement of the sealing area and the support structure, the surfaces of the sealing area and the support structure can be located axially on different planes, which is not possible with a continuously foamed polyurethane end plate. The sealing area is formed, in particular, by an adhesive area in the form of a sealing adhesive connection. Because the surfaces of the foamed volumes can be arranged on different planes, the inner surface of the support structure, in particular, can be axially further away from the air outlet than the surface of the adhesive area or the end face of the filter body.

The support structure can, in particular, have axially outwardly projecting support studs, which, when installed in a housing, allow for stable and vibration-resistant axial bracing within the housing. In this way, the filter element is axially braced against the cover and thus against the housing via the closed end plate, thus providing a fixed support at the front end, the cover-side end of the filter element.

Advantageously, the closed end plate can be formed as a molded part made of a rigid plastic, for example, by injection molding. Alternatively, the end plate can be designed as a two-component end plate with a rigid injection-molded part and an elastic part, e.g., polyurethane or a thermoplastic elastomer.

An open end plate, preferably made of polyurethane, can be provided on the side of the filter body opposite the closed end plate, allowing radial sealing of the filter body. Support studs projecting in the axial direction can also be expediently provided there.

Advantageously, the open end plate can have a radial seal against the housing. This has the advantage that, in addition to providing a good seal and thus a reliable filtering effect, the radial seal and the axial tension of the support studs in the cover can provide radial guidance of the filter element within the housing, thus creating a very stable mount for the filter element within the housing.

The filter body can, for example, consist of a star-pleated filter bellows with a closed, ring-shaped design. The folding can be achieved, for example, by knife folding, for longer filter bodies, or rotary folding. The filter bellows can be made, for example, of paper or cellulose or of a mixed fiber of plastic and cellulose. The filter bellows can also be designed with a smooth surface, rolled and/or with a surface designed in various embossed shapes for stiffening and/or creating cavities for dust deposition. The filter bellows can have a coating and/or impregnation to repel moisture. Alternatively, it can also be coated with nanofibers. The filter body can also be structurally stiffened with a thread winding. A wound filter body with one or more layers is also conceivable.

The axial bulge has through-holes. In particular, the through-holes can be penetrated by the support structure. The support structure can engage through the through-holes in a form-fitting manner, thus forming a particularly stable connection with the end plate.

According to a favorable embodiment, the support structure can be formed from an elastomer, in particular polyurethane. Polyurethane foam can easily penetrate the through-holes during the manufacture of the support structure.

According to a favorable embodiment, the filter body can be foamed onto the end plate at its end face with an elastomer, particularly polyurethane. The support structure with the sealing adhesive connection to the filter body can then be manufactured in a common casting shell. Alternatively, the filter body can be bonded to the end plate at its end face with an adhesive. Alternatively, the filter body can be welded to the end plate at its end face. This allows for flexible and demand-oriented production of the filter element.

According to a favorable design, the filter body can be conically shaped and have a larger outer diameter at the closed end plate than on its opposite end face. This allows for a favorable flow distribution along the filter body.

According to a favorable embodiment, the bulge can be hollow-cylindrical. This provides space for mounting a secondary filter element within the filter element, particularly within a center tube that can engage the bulge.

According to a favorable embodiment, the recess can be designed to accommodate a secondary filter element. In particular, a support area for the secondary filter element can be provided in the recess of the end plate. The filter element and the secondary filter element can be replaced independently of each other.

According to a favorable embodiment, the bulge can be arranged within a clear width of the filter body. A central tube can be provided which engages in the bulge and in which a secondary filter element can be arranged. The end plate can advantageously have an insertion bevel on the inside, also in the area into which the central tube engages, which center the filter element during assembly on the central tube. In one embodiment, the axially inner boundary surface of the support structure can bear against the central tube, so that the support structure can be clamped between the housing cover and the central tube, so that no or less axial clamping force is transmitted via the filter bellows in the direction of the other end plate.

According to a further aspect of the invention, a filter system is proposed, comprising a housing with a longitudinal axis, a cover which closes the housing at one end face, an inlet nozzle arranged on the housing for supplying a medium to be filtered and an outlet nozzle arranged on the housing for discharging the filtered medium, as well as a replaceable filter element which has an annularly closed filter body which is elongated along a longitudinal axis and a closed end plate which is firmly connected to the filter body and to which the end face is tightly connected, wherein the end plate has a fixing position for an axially outwardly projecting support structure, wherein the fixing position is arranged in a bulge of the end plate and the fixing position is arranged with respect to a radial position within an outer skin of the filter body and axially outwardly in front of the end face of the filter body, and wherein the bulge extends a space defined by an inner side of the filter body.

Because the space defined by the inner side of the filter body is extended by the bulge, the thus extended space extends beyond the front side of the filter body of the filter element and preferably beyond the outer edge of the end plate. This allows for a longer secondary element and/or creates the space required for a handle located on the secondary element.

According to a favorable embodiment, a central tube fixed to the housing can be provided. This can be latched to the housing.

On the side of the filter body opposite the closed end plate, an open end plate can be provided, which can in particular be made of polyurethane and which allows a radial seal of the filter body. Support studs projecting in the axial direction can expediently be provided there. The closed end plate can have support studs for axial and/or radial force transmission between the cover and the second end plate. In this way, the force exerted on the end plate by closing the cover can be passed through it and introduced into the center tube, resulting in a secure mounting of the filter element. In particular, the end plate can have an insertion bevel on the inside, even in the area into which the center tube engages, which centers the filter element during assembly on the center tube. Optionally, the axially inner boundary surface of the support structure can bear against the center tube, so that the support structure can be clamped between the housing cover and the center tube, so that no or less axial clamping force is transmitted via the filter bellows towards the opposite open end plate.

Advantageously, the closed end plate can also have support studs for axial and/or radial force transmission between the cover and a secondary filter element located within the filter element. This allows the force exerted on the end plate by closing the cover to be transmitted through the end plate and into the secondary filter element, which in turn can be pressed firmly into its housing seat. This enables a secure mounting of the secondary filter element and, at the same time, a good seal between the unfiltered and filtered areas of the filter system.

The sealing area of the open end plate of one or both filter elements towards the housing is designed in a preferred embodiment as in WO 2012/172019 A1 or US 2014/0102058 A1 The contents of both applications are hereby expressly incorporated by reference, and their disclosure is fully incorporated into this application.

It is advantageous to use a filter system as an air filter, especially as an air filter in compressors, agricultural machinery or other devices with internal combustion engines.

Short description of the drawings

Further advantages will become apparent from the following description of the drawings. The drawings illustrate exemplary embodiments of the invention. The drawings, the description, and the claims contain numerous features in combination. Those skilled in the art will also expediently consider the features individually and combine them into useful further combinations.

• 1 eine perspektivische Ansicht eines Filtersystems nach einem Ausführungsbeispiel der Erfindung mit radial angeordnetem Einlassstutzen und zentrischem Auslassstutzen nach einem Ausführungsbeispiel der Erfindung;
• 2 als Viertelschnitt eine perspektivische Ansicht eines Filterelements nach einem Ausführungsbeispiel der Erfindung;
• 3 ein Detail des Filterelements aus 2 ohne Abstützstruktur an der Endscheibe und Abdichtbereich in Form eines dichtenden Klebebereichs am Filterelement;
• 4 einen Längsschnitt durch ein Filtersystem mit primärem Filterelement und Sekundär-Filterelement nach einem Ausführungsbeispiel der Erfindung; und
• 5 als Schnittdarstellung ein Detail des Filtersystems aus 4.

Examples include:

• 1 a perspective view of a filter system according to an embodiment of the invention with a radially arranged inlet nozzle and a central outlet nozzle according to an embodiment of the invention;
• 2 a quarter-section perspective view of a filter element according to an embodiment of the invention;
• 3 a detail of the filter element 2 without support structure on the end plate and sealing area in the form of a sealing adhesive area on the filter element;
• 4 a longitudinal section through a filter system with a primary filter element and a secondary filter element according to an embodiment of the invention; and
• 5 a sectional view of a detail of the filter system 4 .

Embodiments of the invention

In the figures, identical or similar components are designated by the same reference numerals. The figures are merely examples and are not to be construed as limiting.

1 shows a perspective view of a filter system 100 according to an embodiment of the invention with a radially arranged inlet nozzle 102 and a central outlet nozzle 104. Shown is a round filter design consisting of a housing 108, which is closed at one end with a cover 110. In the case of an air filter system, dust-laden air flows into the inlet nozzle 102, which is arranged, for example, radially to the internally installed air filter element. The cleaned air can be discharged from the housing 108 via the central outlet nozzle 104.

The inlet nozzle 104 can be welded with its collar 106 at any angular position to the previously perforated housing 108.

The 2 and 3 show a quarter-section perspective view of a filter element 10 according to an embodiment of the invention, wherein 3 a detail of the filter element 10 from 2 omitting the support structure 40 and sealing area in the form of a sealing adhesive connection 52.

2 shows the filter element 10, which comprises a closed filter body 12 elongated along a longitudinal axis L and a closed end plate 20 firmly connected thereto. The filter body 12 is tightly connected with its end face 50 to the closed end plate 20. The end face 50 of the filter body 12 engages in a radially outer groove between a downwardly bent edge 38 of the end plate 20 and a radially inner collar 26 of the end plate 20. The sealing adhesive connection 52 is arranged on the filter body 12, for example by polyurethane as a sealant and adhesive filling the groove, partially penetrating the end face 50 and tightly and firmly connecting it to the end plate 20. Alternatively, the connection can be made by means of an adhesive or by welding the filter body 12 to the end plate 20. A small bead 36 is arranged in the groove, which spaced the end face 50 from the groove bottom so that a sufficient amount of sealant can pass between the end face 50 and the groove bottom.

The closed end plate 20 has a fixing position 32 for an axially outwardly projecting support structure 40, wherein the fixing position 32 is arranged in a bulge 30 of the end plate 20 axially outwardly in front of the end face 50 of the filter body 12. Relative to a radial position, the bulge 30 is positioned within an outer skin of the filter body 12 and in particular within the inner diameter of the filter body 12. As shown in 3 As can be seen, the bulge 30 has through-openings 34 at the fixing position 32. This allows the support structure 40 to be connected to the end plate 20 in a form-fitting manner by the support material passing through the through-openings 34, e.g., polyurethane (also referred to as PUR) foaming around the through-openings 34 during the manufacture of the support structure 40. This results in a firm, form-fitting connection between PUR and the molded part (end plate 20), and both PUR areas can be produced from the same side, i.e. the liquid polyurethane can be dosed from the same side.

The through-openings 34 form a groove bottom of an axially inner groove between the inner collar 26 and a radially inner collar 28. The collar 26 has a small shoulder 27 in the area of the groove with the through-openings 34, so that the support material, e.g., polyurethane, can additionally anchor itself securely in the groove. On the other hand, the through-openings 34 form the groove bottom of an axially outer groove between a collar 22 and a collar 24. The support structure 40 has axially outwardly projecting support studs 44.

Through this arrangement of sealing area - in the form of a sealing adhesive connection 52 (see 2 , in 3 (not shown for clarity) and support structure 40, the axially upper surface of the sealing adhesive connection 52 and the axially lower surface 42 of the support structure 40 can be located axially at different levels, which is not possible with a continuously foamed polyurethane end plate. Because the surfaces of the foamed volumes of the sealing region and support structure 40 can be arranged at different levels, in particular the axially lower surface of the support structure can be axially further away from the air outlet than the axially upper surface of the bonding region or the end face of the filter body.

The support knobs 44 of the closed end plate 20, which are arranged radially outwardly extending in a circle around the longitudinal axis L, can be installed when the filter element 10 is installed in the housing 108 ( 1 ) resting against an inner cover contour of the cover 110 are axially supported on the housing 108.

On the opposite end face 60 of the filter body 12, an open annular end plate 70 is arranged, which, in the installed state, creates a radial seal and is provided with support studs 72 that protrude axially from the filter body 12. The open end plate 70 is advantageously formed from polyurethane, which is foamed onto the end face 60.

The filter body 12 can, for example, consist of a zigzag-folded (pleated) filter bellows and be designed in a closed ring shape. The folding can be produced, for example, by knife folding, for longer filter bodies 12, or rotary folding. The filter bellows can, for example, be made of paper, cellulose, or a mixed fiber of plastic and cellulose and can be designed with a smooth surface, rolled, and/or a surface designed in various embossed shapes for stiffening and/or creating cavities for dust deposition. The filter bellows can have a coating and/or impregnation to repel moisture. Alternatively, it can also be coated with nanofibers. The filter body 12 can also be structurally stiffened, e.g., with a continuous strip of hot-melt adhesive, a wound adhesive strip, a so-called thread wrap in the form of a thread, tape, or the like impregnated with hot-melt adhesive.

The bulge 30 of the closed end plate 20 creates a free space within the filter element 10, which allows for the provision of a central tube within the filter element 10, if required, which extends axially beyond the filter body 12. Optionally, additionally or alternatively, a secondary filter element can also be provided if required, which extends axially beyond the filter element 10. The central tube and secondary filter element can thus be arranged independently of the sealing structure of the filter element 10.

4 shows a sectional view through a filter system 100 with primary filter element 10 and secondary filter element 80 as well as with a center tube 90 according to an embodiment of the invention. 5 shows a sectional view of a detail of the filter system 100 from 4 .

The filter system 100 has a radially arranged inlet nozzle 102 and a central outlet nozzle 104 in a housing 108. The housing 108 is closed at one end with a cover 110. In the case of an air filter system, dust-laden air flows into the inlet nozzle 102, which is arranged, for example, radially to the internally installed filter element 10. The cleaned air can be discharged from the housing 108 via the central outlet nozzle 104. The inlet nozzle 104 can be welded with its collar 106 at any angle to the previously perforated housing 108. The filter system 100 can be used as an air filter, for example, in construction machinery, agricultural machinery, compressors, and other devices with combustion engines.

A filter element 10 is arranged in the housing 108, concentrically surrounding a central tube 90 and a secondary filter element 80. The optional central tube 90 is fixed to the housing and snapped to the housing 108 at the outlet end. The filter body 12 can be conically shaped and have a larger outer diameter at the closed end plate than at its opposite end face 60. The end plate 20 has an insertion bevel on the inside in the area into which the central tube 90 engages. which centers the filter element 10 during assembly on the center tube 90.

The design of the filter element 10 with end plate 20 and support structure 40 is shown in the 2 and 3 described, to which reference is made. The center tube 90 and the secondary filter element 80 extend into the bulge 30 of the closed end plate 20 and thus project axially beyond the filter element 10.

The secondary filter element 80 essentially consists of a support tube 82 as a supporting structure and a relatively permeable filter medium 84, for example a fleece, arranged thereon. The secondary filter element 80 can remain in the housing 108 when the filter element 10 is replaced to protect the further air duct, for example of an internal combustion engine, against penetrating dust particles and other objects. The secondary filter element 80 is inserted with its open end into a housing seat on the outlet-side part of the housing 108. The closed end 86 of the secondary filter element 80 rests in the bulge 30 of the closed end plate 20 of the filter element 10, whereby when the housing cover 110 is closed, a force can be directed via the support knobs 44 of the end plate 20 into the closed end of the secondary filter element 80 and the secondary filter element 80 is pressed firmly into its housing seat on the outlet connection 104. A handle 88 is connected to the closed end 86, which facilitates the removal of the secondary filter element 80.

In this way, the filter element 10 is clamped axially against the cover 110 and thus against the housing 108 in addition to the central tube 90 via the closed end plate 20 and is thus fixedly mounted on the end face 50, the cover-side end of the filter element 10.

Claims (14)

A filter element (10) comprising a closed filter body (12) elongated along a longitudinal axis (L) and a closed end plate (20) firmly connected thereto, to which the filter body (12) is tightly connected with its end face (50), wherein the end plate (20) has a fixing position (32) for an axially outwardly projecting support structure (40), wherein the fixing position (32) is arranged in a bulge (30) of the end plate (20) and the fixing position (32) is arranged outwardly with respect to a radial position within an outer skin of the filter body (12) and axially in front of the end face (50) of the filter body (12), and the bulge (30) extends a space defined by an inner side of the filter body (12), wherein the bulge (30) has through openings (34) in the axial direction. Filter element according to Claim 1 , wherein the through openings (34) are penetrated by the support structure (40). Filter element according to one of the preceding claims, wherein the support structure (40) is formed from an elastomer, in particular polyurethane. Filter element according to one of the Claims 1 until 3 , wherein the filter body (12) is foamed onto the end plate (20) on its front side (50) with an elastomer, in particular polyurethane. Filter element according to one of the Claims 1 until 3 , wherein the filter body (12) is glued to the end plate (20) on its front side (50) with an adhesive. Filter element according to one of the Claims 1 until 3 , wherein the filter body (12) is welded to the end plate (20) on its front side (50). Filter element according to one of the preceding claims, wherein the filter body (12) is star-folded. Filter element according to one of the preceding claims, wherein the filter body (12) is conically shaped and has a larger outer diameter at the closed end plate (20) than at its opposite end face (60). Filter element according to one of the preceding claims, wherein the bulge (30) is hollow-cylindrical. Filter element according to one of the preceding claims, wherein the bulge (30) is designed to receive a secondary filter element (80). Filter element according to one of the preceding claims, wherein the bulge (30) is arranged within a clear width of the filter body (12). Filter system (100), comprising - a housing (108) with a longitudinal axis (L), - a cover (110) which closes the housing (108) at one end face, - an inlet nozzle (102) arranged on the housing (108) for supplying a medium to be filtered and an outlet nozzle (104) arranged on the housing (108) for discharging the filtered medium, and - a replaceable filter element (10) according to one of the preceding claims. Filter system (100) according to Claim 12 , wherein a central tube (90) fixed to the housing is provided. Use of a filter system (100) according to one of the Claims 12 until 13 as an air filter, especially as an air filter of an internal combustion engine.

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