Filter system and use of a filter element

Abstract

Filter system (100) comprising at least one replaceable filter element (10, 11) separating a raw side from a clean side of the filter system, and a filter housing (108) with at least one first housing part (109) and at least one second housing part (110) for enclosing a filter element (10, 11), with at least one inlet (102) and at least one outlet (104) for a fluid in a housing wall, wherein at least one sensor element (122) is arranged in the first and / or second housing part (109, 110), which is provided for interacting with at least one counter element (144) of an inserted filter element (10, 11) for identifying the type and / or size of the inserted filter element (10, 11), wherein the sensor element (122) comprises an electromechanical switch which can be actuated by the at least one counter element (144) of an inserted filter element (10, 11). is,wherein the sensor element (122) is arranged in a position in which, based on geometry data of usable filter elements, it is contactable by one type of filter element used as intended and is not contactable by another type of filter element used as intended, so that the sensor element identifies the type of filter element currently used.

Description

Technical field The invention relates to a filter system, in particular for an air filter for cabin air purification, and to the use of a filter element for replacement in such a filter system. State of the art From EP 2 368 616 A1, a filter is known which informs the user when filter elements need to be replaced. From WO 00 / 32 298 A1, an arrangement with identification features on a filter is known. From DE 201 04 481 U1, a filter element with a transponder is known. From DE 29 47 655 A1 a filter housing is known which has means for inserting at least two different filter elements of different sizes in such a filter housing, wherein the means are able to provide a hermetic seal in different areas of the filter housing according to the filter elements of different sizes. The central part of the filter housing is cylindrical and has an air inlet opening to which an inlet nozzle is connected via a cylindrical section. In its lower region, the central part has an outwardly facing annular rim. This lower region or section is also cylindrical and is closed off by a base or bottom section, while the bottom section has an outwardly facing annular rim at its upper edge. The lower part is attached to the central part by means of known snap-fit ​​clamps, which compress an annular seal between the rims of the parts. This seal has a slot that receives an outwardly facing upper annular rim of a sieve, which defines a lower region of the filter housing in the lower part where the dust ejected from the air to be filtered is collected.The sieve has a ring-shaped wall that essentially rests against the inner surface of the lower part, and therefore forms a flat wall at the bottom in the form of a circular band which has an opening. Additionally, the sieve is equipped with various flat sections, namely walls of the filter housing to accommodate the main filter elements of different heights, and it also has annular walls of varying diameters and heights, specifically those located in or near the outer annular end of the main filter element. The lower section of the main filter element is permanently centered by the upper vertical annular walls of varying diameters. Finally, the lower discs of the various main filter elements are attached at different heights to a threaded rod by means of a wing nut in the form of a tie rod. Disclosure of the invention One object of the invention is to create a filter system consisting of a filter housing and a filter element, in particular for an air filter for cabin air purification, which makes it possible to easily and cost-effectively insert different filter elements with different dimensions into a filter housing in a verifiable manner and to seal them during operation. The aforementioned problem is solved by a filter system according to claim 1. Favorable embodiments and advantages of the invention will become apparent from the further claims, the description and the drawing. According to the invention, a filter system for filtering a fluid is proposed, comprising at least one replaceable filter element that separates a raw side from a clean side of the filter system. The filter system further comprises a filter housing with at least one first housing part and at least one second housing part, which are designed to enclose a filter element, and which has at least one inlet and one outlet for a fluid in a housing wall. At least one sensor element is arranged in the first and / or second housing part, which is designed to interact with at least one counterpart element of an inserted filter element and identifies the type and / or size of the inserted filter element. The invention relates in particular to air filters for cabin air purification, for example in the interior of motor vehicles. With such filter systems, it is common practice that there is a suitable filter element geometry for each filter housing, which can be used in that specific filter housing. If filter elements with different requirements are to be used for different applications, which may have different dimensions such as outer diameter and / or length or even different weights, these different filter elements do not fit into the same housing. Instead, different filter housings usually have to be provided for them, which is disadvantageous for reasons of cost and / or installation space.This geometric difference in the filter elements can arise, for example, as a result of different requirements such as dust separation and / or aerosol separation or adsorption of harmful gases according to various specifications. According to the invention, it is possible to use a sensor element integrated into the filter housing to check for the presence of a required filter element for a specific operation, such as an activated carbon filter element for applying pesticides or a particulate filter element of an agricultural machine for working a field, and to display this information. The sensor element's signal can be transmitted via a data line to a control unit of a vehicle or agricultural machine and, after appropriate evaluation, displayed in this control unit. The information can be displayed, for example, on the dashboard of a vehicle. However, a suitable display can also be located elsewhere on the vehicle or agricultural machine.It is also conceivable that the notification represents a mandatory inspection with legal consequences to determine whether the prescribed equipment is being used for a specific work process and, for example, whether there is any risk to the operating personnel. In a non-inventive embodiment, it is conceivable that the sensor element could instead be arranged on the filter element and the counterpart element on the housing. In an embodiment according to the invention, the sensor element comprises an electromechanical switch which can be actuated by the at least one counterpart element of an inserted filter element. Due to the different geometric data of the usable filter elements, the available filter elements can be easily identified, for example, by means of a type of electromechanical switch that is closed by mechanical contact when a specific type of filter element is inserted, for example via an end plate of a filter element, or that remains open with a different type of filter element. In this way, at least one geometric parameter can be reliably verified.It is also conceivable to use several mechanical switches so that multiple dimensions of the filter element can be checked. According to the invention, the sensor element is arranged in a position which, for example, is contacted by one type of filter element due to its diameter and / or length, but not by another type of filter element used as intended. Thus, the geometric position of the sensor element allows for the unambiguous identification of different types of filter elements. This also applies to a non-inventive embodiment in which the sensor element and the corresponding element are reversed. In a non-inventive embodiment, the sensor element can comprise a non-contact sensor, in particular an inductive sensor, for detecting the at least one corresponding element of an inserted filter element.For example, a Hall sensor can be used as the sensing element, while a magnetic metallic element can be used as the counterpart, which can then be detected based on changes in the surrounding magnetic field. The use of an RFID chip system for contactless detection is also conceivable. For instance, a transmitter-receiver could be used that sends a signal to a chip integrated into a filter element and then receives a signal from this chip containing the specific data of the filter element, describing its exact type. According to the invention, a filter element of a different type is used in which the sensor element is not contacted. Advantageously, the sensor element is arranged in a position in which it is not actuated or detected due to the length and / or diameter of the filter element of the first type, wherein a filter element of a second type of greater length and / or larger diameter can be used, by which the sensor element can be actuated due to its greater length and / or larger diameter. Advantageously, at least one of the housing parts can have a centering contour for radially fixing and radially sealing a filter element in the installed state, while the other housing part has at least two radial guide contours which are arranged coaxially to each other at different axial heights, so that alternatively at least two different filter elements with different diameters and / or different axial lengths can be inserted into the filter housing in such a way that the respective inserted filter element is held in a defined position in the radial and axial directions and its clean side is sealed against its unclean side. The filter housing according to the invention thus has the advantage that, due to the design of the structural details in the filter housing, filter elements with different outer diameters and / or different lengths can be installed and sealed in one filter housing.A single filter housing can be used for at least two different filter element geometries (outer diameter and length), which may be required depending on the application of the filter system and the optimal design. This allows for a foolproof Poka-Yoke system to differentiate the filter elements for different applications. The radial seal on the centering contour creates an independent sealing option in the filter housing in addition to an axial seal, by pressing the filter element centered around the radial sealing surface of the centering contour when inserted into the filter housing with a corresponding radial sealing surface. Advantageously, one of the housing parts can have a support contour for axial support and / or sealing by means of an end-face sealing surface of an inserted filter element, which surrounds the centering contour. Thus, when the filter element is installed in the filter housing, it is pressed onto the support contour via a corresponding sealing surface on the filter element side, ensuring an axial seal from the raw side to the clean side of the filter element. According to the inventive solution, a filter element can rest on the support contour in the first housing part of the filter housing and be inserted in a centered position with the aid of the centering contour. Furthermore, when the two housing parts are assembled, it can be clamped in a centered position in the assembled filter housing via the first and / or second guide contour of the at least two guide contours in the second housing part.The guide and centering elements are arranged in the two housing parts in such a way that they allow the installation of at least two different filter elements with different outer diameters and lengths. The first housing part can, for example, be designed as a housing pot, while the second housing part is designed as the corresponding housing lid. Alternatively, both housing parts can be designed as housing pots and screwed or clipped together in the middle of the filter housing. A further advantage of the filter housing according to the invention is that the centering contour has a radial sealing surface for radial sealing between the clean side and the raw side of at least one of the filter elements when installed, wherein the radial sealing surface is formed on an outer side of a central tubular pipe section projecting into the interior of the housing. In this way, a very reliable seal between the raw side and the clean side of the filter element is ensured, since both an axial and a radial seal of the installed filter element is possible. The central tubular pipe section can advantageously open into or form the central outlet of the filter housing. In an advantageous embodiment, the centering contour can have at least two areas with different diameters on its tubular section projecting into the interior of the housing, wherein the area with the smallest diameter is arranged axially inside, and wherein the centering contour is preferably designed in the transition area between the at least two areas to support the weight of an inserted filter element. Particularly heavy filter elements, for example with an activated carbon filter bellows, which may be constructed without a stabilizing central tube, are advantageously additionally supported in order to absorb or support the weight of the filter element.Such weight absorption is possible through the inventive mounting of the filter element inside the filter bellows on a step of the centering contour, which connects the two areas of different diameters, so that the filter element can support itself on it with appropriate counter-geometry and thus the weight of the filter element can be absorbed by the step. This is particularly advantageous if an inner opening of the filter element can be accommodated by this transition area. Ideally, the inner diameter of the filter element is chosen such that, when the filter element is inserted into the second housing part, it rests on the shoulder of the transition area with this inner diameter, thus supporting the weight of the filter element. In a further advantageous embodiment, a contact area can be provided radially outside the centering contour, allowing a filter element of a suitable diameter to be radially fixed by means of this contact area when installed. This contact area can thus act as an additional guide element, guiding the filter element along its outer diameter and providing an external centering function in addition to the centering contour, which performs an internal guiding function by accommodating the inner opening of the filter element. This contact area ensures that the filter element is securely mounted in the filter housing during operation, so that the centering contour does not have to assume the sole centering and holding function in the event of vibrations. This relief can be particularly advantageous with regard to the additional radial sealing function of the centering contour. In particular, the second guide contour can also be an axially inwardly projecting frame that is arranged radially outside the first guide contour. This allows filter elements of different lengths to rest against the first guide contour or against the second guide contour and be centered in the filter housing. A shorter filter element can thus rest against the second guide contour, which is radially outer but positioned lower, while a longer filter element rests against the first, radially inner guide contour and can be centered. This allows at least two different filter element geometries to be installed in the filter housing. Advantageously, the first guide contour can be designed as a step in the base of the second housing part. Such a step is very cost-effective to manufacture using a plastics production process and therefore represents a favorable solution for a plastic filter housing. The step design also automatically provides a guide contour in an otherwise flat housing part, such as a housing cover. Similarly, the second guide contour can also be designed as another step in the base of the second housing part. When the second housing part is closed with the first, the first bottom end plate of a filter element can be pressed into the step and thus secured both axially and radially. According to a further aspect, the invention relates to the use of a filter element for installation in a filter housing comprising a first housing part and a second housing part extending in the axial direction, wherein the filter element includes at least one counter element for interacting with at least one sensor element in the filter housing that identifies the type and / or size of the filter element. Depending on the sensor type, the counter element provides a response to the sensor element, so that the signal from the sensor element can be used to determine whether a specific type of filter element is installed or not. In this way, the filter element can be uniquely identified by its type, thus ensuring that the correct and suitable filter element is used for a given operating application of a filter system. Advantageously, at least one counter element can preferably be arranged in an end plate. This ensures a space-saving arrangement of the counter element. Furthermore, it cannot be damaged or unintentionally removed. In the case of an electromechanical switch as a sensor element in the filter housing, it is even conceivable that the end plate itself constitutes the counter element, provided that the end plate, with sufficient material stiffness, is capable of actuating an electromechanical switch. In an advantageous embodiment, the s can comprise at least one counter element, a metallic element integrated into an end plate, which is detectable by a sensor element arranged on a filter housing. The metallic element can, for example, actuate and close an electromechanical switch via a purely mechanical contact. In an alternative embodiment not according to the invention, it is also conceivable that the metallic element provides a magnetic signal via an inductive sensor element or a Hall sensor as the sensor element, which can be evaluated and displayed in a suitable control unit. For this purpose, the metallic element can also be embedded in a plastic end plate and does not need to protrude with its surface, as is necessary when closing an electromechanical switch. When using an inductive sensor element not according to the invention, the at least one counterpart element can comprise information about at least the type and / or size of the filter element in analog and / or digitally stored form, so that the information can be detected by a sensor element arranged on a filter housing. For example, information about the exact type of the filter element and the one or more integrated filter bellows can be stored in the counterpart element. In this way, information about the type of filter bellows can be made available via the sensor element, in addition to the purely mechanical data of the filter element. This information can, for example, be contained in an analog and / or digital form in a memory chip. It is also conceivable to apply a digital code, such as a Data Matrix code, to an outer surface of the filter element, which can be read and interpreted via an optical sensor element.The use of an RFID chip system for contactless identification is conceivable. The counterpart would then contain the RFID chip, which in turn could be detected and read via a suitable sensor element. This information could then be displayed to the driver or operator of an agricultural machine via a control unit. In principle, in a non-inventive embodiment, it is conceivable that the sensor element can instead be arranged on the filter element and the counterpart element on the housing. In an advantageous embodiment, the filter element can comprise at least one first end plate arranged on an end face of a filter bellows, with a support element and a radial seal, wherein the support element is designed to interact with a corresponding support contour and the radial seal is designed to interact with a centering contour of the filter housing. Furthermore, the filter element can comprise at least one second end plate arranged on a second end face of a filter bellows, with support elements designed to interact with a base of the second housing part. These support elements can, for example, advantageously be arranged radially in a circle at a fixed angular interval, for example at regular intervals, such as 72° for a circular arrangement of five support elements.It is also conceivable to have several concentrically arranged circular arrangements that may be offset from each other in their angular orientation. The filter bellows can be a conventional cellulose filter bellows, as is common in air filters. However, it can also consist of several parts arranged radially stacked on top of each other, one of which might be made of activated carbon. This results in a significantly higher weight for the filter element. Such filters can be used, for example, in agriculture for pesticide application in agricultural machinery. The two end plates of the filter element can advantageously be made of polyurethane, in which the filter bellows is foamed at both ends. If the filter bellows is sufficiently rigid, a stiffening central tube of the filter element can be omitted, so that the stability of the filter element is provided solely by the filter bellows and the two end plates.The support element and the radial seal can advantageously be foamed together with the first end plate, while the support elements can be foamed together with the second end plate. Due to the use of polyurethane, the support element, radial seal, and support elements also exhibit sufficient elasticity to allow the filter element to be elastically compressed between the two housing parts when the filter housing is closed, thus sealing between the raw and clean sides of the filter element. The fluid path for filtering runs radially from the outside to the inside. Therefore, the second end plate is advantageously continuous, while the filtered fluid is discharged downwards through an opening in the first end plate within the hollow interior of the filter bellows, which, for example, leads to an outlet of a filter system. The filter element can be axially supported on the support contour via the support element in the first housing part and radially centered on the centering contour via the radial seal, or it can be axially sealed by placing the support element on the axial sealing surface of the support contour and radially sealed by placing the radial seal on the radial sealing surface of the centering contour. Advantageously, the filter element can be supported by the support element on the support contour and centered by the radial seal on the centering contour of the filter housing. According to the invention, the filter element can rest on the support contour in the first housing part of the filter housing and be inserted centered by the centering contour. Furthermore, it can be clamped in the assembled filter housing via the first and / or second guide contour in the second housing part, centered by the guide and centering elements. The guide and centering elements are arranged in the two housing parts in such a way that they allow the installation of at least two different filter elements with different outer diameters and lengths. According to the invention, the replaceable filter element can rest on a support contour in the first housing part of the filter housing and be inserted in a centered position using a centering contour. Furthermore, it can be clamped in the assembled filter housing by means of a first and / or second guide contour (or at least two guide contours) in the second housing part. The guide and centering elements are arranged in the two housing parts such that they allow the installation of at least two different filter elements with different outer diameters and lengths. The first housing part can, for example, be designed as a housing pot, while the second housing part is designed as the corresponding housing cover. Alternatively, both housing parts can be designed as housing pots and screwed or clipped together in the center of the filter housing.The fluid to be filtered can be supplied via a radial inlet, penetrate radially through the inserted filter element and be guided outwards in the hollow inner area of ​​the filter bellows into an axial outlet of the filter housing. In an advantageous embodiment, the filter element can be compressed axially when the first housing part is closed with the second housing part by bracing the support elements against the base. The force applied by closing the filter housing is transferred via the base of the second housing part to the support elements, which in turn transfer the force to the filter element via the second end plate. This presses the filter element into a tight fit and also mechanically secures it during operation, protecting it against potential movement due to vibrations of the filter system. Advantageously, the filter element in the second housing part can be guided radially from the inside by aligning an outer edge of the second end disc with the first and / or second guide contour of the second housing part. Since the first and / or second guide contour can advantageously be designed as a step in the base of the second housing part, the outer edge of the second end disc can thus fit snugly against this frame-like step and thereby be guided radially during assembly of the filter system and protected against radial movement during operation. The filter element can also be advantageously guided radially by applying the radial seal to the centering contour when the filter element is inserted into the first housing part. When inserting the filter element into the first housing part, the radial seal can be pushed onto the centering contour, which can, for example, be designed as a tubular pipe section serving as the outlet of the filter housing, and thus guided radially. This also protects the filter element against radial movement due to vibrations during operation. Advantageously, the filter element can be sealed radially within the filter system between the clean side and the raw side of the filter system by pressing a base of the second housing part against support elements of a second end plate of the filter element, via a radial seal against a centering contour, and by pressing a support element against a support contour of the first housing part. The centering contour advantageously has a radial sealing surface on its outer side, which faces the radial seal of the filter element. The radial seal can bear against this surface and, when the filter housing is closed, is pressed into the sealing seat by the force applied to the filter element by pressing the support elements against it.Furthermore, the support contour has an axial sealing surface against which the support element can rest and, when the filter housing is closed, is pressed into the sealing seat by the force applied to the filter element by pressing the support elements against it. Advantageously, the support elements on the base of the second housing part can be supported by folding them radially outwards and / or inwards. Since the end discs of the filter element with the integrated support elements are preferably made of foamed polyurethane and therefore possess elastic properties, they can be elastically deformed when the base of the second housing part is pressed against them. Whether the support elements preferably fold radially outwards and / or inwards, thus transferring the mechanical force from the base to the end disc and therefore to the filter element, depends on their shape. The actual design depends on the geometric shape of the filter element, for example, whether the outer edge of the filter element rests against the first or the second guide contour. In an advantageous embodiment, the centering contour can have at least two sections with different diameters on its tubular section projecting into the interior of the housing, with the section with the smallest diameter being arranged axially inside. These sections with different diameters can serve to support heavy filter elements on the filter housing. Particularly heavy filter elements, for example, those with activated carbon filter bellows, which may even be constructed without a stabilizing central tube, are advantageously supported in this way to reduce the weight of the filter element. Advantageously, the centering contour can be formed in a transition area between the at least two areas for supporting the weight of the inserted filter element, and an inner opening of the filter element can be accommodated by the transition area. Such weight absorption is made possible by the inventive mounting of the filter element inside the filter bellows on a shoulder that connects the two areas of different diameters of the centering contour, so that the filter element can rest on it with a corresponding counter-geometry, and thus the weight of the filter element can be absorbed by the shoulder. Filter elements can have different inner diameters of the filter bellows depending on the diameter of the centering contour, whereby the centering contour can project into the filter element far enough to achieve weight absorption / support of the filter element. The described filter system can be used as an air filter, in particular as an air filter for the interior air of driver's cabins of vehicles, agricultural, construction and work machines. Brief description of the drawings Further advantages 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. A person skilled in the art will expediently consider the features individually and combine them into meaningful further combinations. Figure 1 shows, by way of example, a filter system cut in half according to an embodiment of the invention with a first filter element; and Figure 2 shows a filter system cut in half according to a further embodiment with a second filter element which has a smaller outer diameter and a greater length. Embodiments of the invention In the figures, identical or similar components are numbered with the same reference symbols. The figures merely show examples and are not to be understood as limiting. Fig. 1 shows a filter system 100, cut in half, according to an embodiment of the invention, with a first filter element 10. The filter system 100 for filtering a fluid comprises a replaceable filter element 10, which separates a raw side 52 from a clean side 50 of the filter system, a filter housing 108 with a first housing part 109 and a second housing part 110, which enclose the inserted filter element 10, with at least one inlet 102 and one outlet 104 for a fluid in a housing wall. The filter system 100 has at least one sensor element 122 arranged on the filter housing 108 for detecting a filter element 10, 11 inserted in the filter housing 108, which identifies a type of filter element 10, 11 currently inserted.The filter element 10 has a counterpart element 144 for interacting with the sensor element 122 in the filter housing 108, which identifies the type and / or size of the filter element 10. One of the counterpart elements 144 is preferably arranged in an end disk 16, 18. The sensor element 122 can advantageously be arranged at various locations within the filter housing 108. It should be noted that it typically requires an electrical connection, which must be routed appropriately and remain attached to the sensor element 122 when the filter element 10, 11 is replaced. Therefore, it is advantageous if the sensor element 122 is arranged on a permanently installed housing part 109, 110. However, a flexible or pluggable connection to the sensor element 122 is also conceivable, allowing it to be arranged on a housing part 110, 109 that may need to be removed when replacing the filter element 10, 11. In the embodiment shown in Fig. 1, three different positions of a sensor element 122 are indicated.The sensor element 122a is located at the level of the mounting area 138 and is designed to interact with at least one counter element 144a of the filter element 10, which is characteristic of the type and / or size of the filter element 10. The counter element 144a is arranged in the first end disk 16 of the filter element 10, for example, by being foamed into the end disk 16. Alternatively, the sensor element 122a can be arranged at positions 122b, 122c, and 122d on the second housing part 110 in the area of ​​the base 120. In this case, a suitable position for the counter element 144b would be in the area of ​​the second end disk 18, as shown in Fig. 1. In that case, the counterpart element 144b would be detected by the sensor element 122 at both positions 122b and 122d, while the sensor element 122 would not detect the counterpart element 144b at position 122c because it is too far from the position of the counterpart element 144b. The sensor element 122 comprises an electromechanical switch which can be actuated by the counterpart element 144 of the inserted filter element 10. In an unclaimed alternative embodiment, the sensor element 122 can comprise a non-contact sensor, in particular an inductive sensor, for detecting the at least one counterpart element 144 of an inserted filter element 10, 11. The at least one counterpart element 144 can comprise a metallic element arranged in an end disk 16, 18, which can be detected by a sensor element 122 arranged on a filter housing 108. The metallic element can, for example, actuate and close an electromechanical switch via a purely mechanical contact.In the unclaimed alternative embodiment, it is also conceivable that the metallic element provides a magnetic signal via an inductive sensor element or a Hall sensor as sensor element 122, which can be evaluated in a suitable control unit and displayed. When using an inductive sensor, the at least one counterpart 144 can contain information about at least the type and / or size of the filter element 10, 11 in analog and / or digitally stored form, such that the information can be detected by a sensor element 122 arranged on a filter housing 108. For example, information about the exact type of the filter element 10, 11 and the one or more filter bellows 12 integrated therein can be stored in the counterpart 144. In this way, in addition to the purely mechanical data of the filter element 10, 11, information about the type of a filter bellows 12 can be made available via the sensor element 122. This information can, for example, be contained in an analog and / or digital memory chip. It is also conceivable to apply a digital code, such as a Data Matrix code, to an outer surface of the filter element 10, 11, which can be read and interpreted via an optical sensor element 122.The use of an RFID chip system for contactless identification is conceivable. The counterpart element 144 would then contain the RFID chip, which in turn can be detected and read by a suitable sensor element 122. This information can then be displayed to the driver or operator of an agricultural machine via a control unit. The housing part 109 has a centering contour 124 for radially fixing and radially sealing the inserted filter element 10, while the other housing part 110 comprises a first and a second radial guide contour 116, 118, which are arranged coaxially to each other at different axial heights, so that alternatively at least two different filter elements 10, 11 with different diameters and / or different axial lengths can be inserted into the filter housing 108 in such a way that the respective inserted filter element 10, 11 is held in a defined position in the radial direction and in the axial direction L and its clean side 50 is sealed against its raw side 52. The filter element 10 comprises a first end disk 16 arranged on an end face 15 of a filter bellows 12, with a support element 20 and a radial seal 22, wherein the support element 20 is designed to interact with a corresponding support contour 114 and the radial seal 22 is designed to interact with a centering contour 124 of the filter housing 108, as well as a second end disk 18 arranged on a second end face 17 of a filter bellows 12, with support elements 24 designed to interact with a base 120 of the second housing part 110. The filter element is supported by the support element 20 on the support contour 114 and centered by the radial seal 22 on the centering contour 124 of the filter housing 108. The filter housing 108 for a filter system 100, comprising a first housing part 109 and a second housing part 110, which are intended to enclose the filter element 10, has a radial inlet 102 for supplying the fluid to be filtered and an outlet 104 for the filtered fluid in a housing wall.The housing part 109 has a centering contour 124 for radially fixing and radially sealing the filter element 10 in the inserted state, while the other housing part 110 has a first and a second radial guide contour 116, 118, which are arranged coaxially to each other at different axial heights, so that alternatively at least two different filter elements 10, 11 with different diameters and / or different axial lengths can be inserted into the filter housing in such a way that the respective inserted filter element 10, 11 is held in a defined position in the radial direction and in the axial direction L and its clean side 50 is sealed against its raw side 52. Fig. 1 shows a first filter element 10. The housing part 109 has a support contour 114 for axial support and / or sealing by means of an end-face sealing surface 130 of an inserted filter element 10, which surrounds the centering contour 124. The centering contour 124 has a radial sealing surface 128 for radial sealing between the clean side 50 and the raw side 52 in the inserted state of at least one of the filter elements 10, 11, wherein the radial sealing surface 128 is formed on an outer side of a central tubular pipe section 140 projecting into the housing interior 142, which also opens into the central outlet 104. The centering contour 124 has at least two areas 132, 134 with different diameters on its tubular tube section 140 projecting into the housing interior 142, wherein the area 134 with the smallest diameter is arranged axially inside. The centering contour 124 is designed in the transition area 136 between the at least two areas 132, 134 to support the weight of an inserted filter element 10, 11, with an inner opening 32 of the filter element 10, 11 being accommodated by the transition area 136. Particularly heavy filter elements 10, for example with an activated carbon filter bellows 12, which may also be constructed without a stabilizing central tube, are advantageously supported in order to relieve the weight of the filter element 10. Such relief is made possible by the support of the filter element 10 according to the invention in the transition area 136 of the centering contour 124 between the areas 132, 134 with different diameters.This transition area 136 can connect the two areas 132 and 134 of different diameters as a step, so that the filter element 10, with appropriate counter-geometry, can be supported on it and thus the weight of the filter element 10 can be absorbed by the step, with an inner opening 32 of the filter element 10 being accommodated by the transition area 136. A contact area 138 is provided radially outside the centering contour 124, with which a filter element 10 or 11 of a suitable diameter can be radially fixed in the installed state. The first guide contour 116 is formed as a step in the base 120 of the second housing part 110. The second guide contour 118 of the second housing part 110, also formed as a further step in the base 120, is continued into an axially inwardly projecting flange that is arranged radially outside the first guide contour 116. The second end disc 18 of the filter element 10 is radially fixed to this frame.The filter element 10 is guided radially from the inside in the second housing part 110 by placing an outer edge 30 of the second end disk 18 against the second guide contour 118 of the second housing part 110. Furthermore, the filter element 10 is guided radially by the radial seal 22 against the centering contour 124 when the filter element 10 is inserted into the first housing part 109. The filter element 10 is sealed radially in the filter system between the clean side 50 and the raw side 52 of the filter system 100 by pressing the base 120 of the second housing part 110 against the support elements 24 of the second end disk 18 of the filter element 10, via the radial seal 22 against the centering contour 124. It is additionally sealed axially by pressing the support element 20 onto the support contour 114 of the first housing part 109. The elastic support elements 24 and 26, which in Fig. 1 in the (CAD-derived) representation pierce the second housing part 110, in reality lie on the inside of the surface 123 of the bottom 120 of the second housing part 110 by folding the support elements 24 in a radial direction outwards and / or inwards and are supported on it.The filter element 10 is pressed axially L against the surface 123 of the base 120 when the first housing part 109 is closed with the second housing part 110. In the illustrated filter element 10, the support elements 24, 26 are arranged radially outwards in two concentric circles, such that they can support the filter element 10 against the filter housing 108 at the level of the filter bellows 12, which is particularly advantageous for relatively heavy filter elements 10. The support elements 24, 26 are angularly offset from one another. This reduces the shear stress on the second end disk 18. Figure 2 shows a partially cut filter system 100 according to a further embodiment with a second filter element 11, which has a smaller outer diameter and a greater length. Figure 2 also shows exemplary arrangements of sensor elements 122 on the two housing parts 109 and 110. For example, a sensor element 122a is arranged, as shown in Figure 1, on the contact area 138 in the first housing part 109. This would allow a counter element 144 in an end disk 16 of a filter element 10 to be detected if the end disk 16 were in contact with the contact area 138. However, this is not the case with the filter element 11 shown in Figure 2, so the sensor element 122a would not detect a signal.A sensor element 122, which is located in the area of ​​the support contour 114, can receive a signal from a counterpart element 144a, which is integrated, for example, into the first end disk 16, and detect that the filter element 11 is inserted. Since the sensor element 122a does not have contact with a counterpart element 144a of the first end disk 16 due to the smaller outer diameter of the second filter element 11, it can, for example, detect that a different filter element 11 is inserted into the filter housing 108, and a corresponding indicator can be activated. Further sensor elements 122 are arranged on the second housing part 110 such that they detect counterpart elements 144 in end discs 18 of filter elements 10, 11 that bear against a surface 121 of the base 120 or against a surface 123 of the base 120. In Fig. 2, the counterpart element 144b opposite sensor element 122c on surface 121 would thus be detected. Sensor element 122b or sensor element 122d, on the other hand, would detect whether a counterpart element 144 of an end disc 18 bearing against surface 123 is present, which is not the case in the embodiment shown in Fig. 2 with the filter element 11. These sensor elements 122b and 122d would also detect that a filter element 11 with a smaller outer diameter is used in the filter system 100. The filter element 11 has a filter bellows 12 which has a significantly smaller diameter than the filter bellows 12 in Fig. 1, so that the entire filter element 11 has a smaller outer diameter than the filter element 10 in Fig. 1. As a result, the first end disk 16 does not rest against the frame 138 of the first housing part 109, but the second end disk 18 is radially supported by its outer edge 30 against the first guide contour 116, since the filter element 11 is also longer than the filter element 10. The first guide contour 116 is formed as a step in the surface 121 of the base 120 of the second housing part 110. The support elements 24 penetrate the surface 121 of the base 120 of the second housing part 110, as shown in Fig. 1.1 also the second housing part 110, but in reality, when assembling the filter housing 108, they rest against the surface 121 of the base 120, since they are elastic, for example made of polyurethane, and thus support themselves against the second housing part 110 in order to transfer the force to the filter element 11. The filter element 11 does not rest against the transition area 136 of the centering contour 124, as it has a larger diameter of the inner opening 32, which corresponds to the lower area 132 of the centering contour 124. This is possible if, for example, the filter bellows 12 consists only of cellulose in this case, and therefore the weight of the filter element 11 does not require additional support. Reference symbol list 10 Filter element 11 Filter element 12 Filter bellows 15 First end face 16 First end plate 17 Second end face 18 Second end plate 20 Support element 22 Radial seal 24 Support element 26 Support element 30 Outer edge 32 Inner opening 50 Clean side 52 Raw side 100 Filter system 102 Inlet 104 Outlet 108 Filter housing 109 First housing part 110 Second housing part 112 Bottom area 114 Support contour 116 First guide contour 118 Second guide contour 120 Bottom 121 Surface 122 Sensor element 123 Surface 124 Centering contour 128 Radial sealing surface 130 Axial sealing surface 132 First area 134 Second area 136 Transition area 138 Contact area 140 Pipe section 142 Housing interior 144 Counter element

Claims

Filter system (100) comprising at least one replaceable filter element (10, 11) separating a raw side from a clean side of the filter system, and a filter housing (108) with at least one first housing part (109) and at least one second housing part (110) for enclosing a filter element (10, 11), with at least one inlet (102) and at least one outlet (104) for a fluid in a housing wall, wherein at least one sensor element (122) is arranged in the first and / or second housing part (109, 110), which is provided for interacting with at least one counter element (144) of an inserted filter element (10, 11) for identifying the type and / or size of the inserted filter element (10, 11), wherein the sensor element (122) comprises an electromechanical switch which can be actuated by the at least one counter element (144) of an inserted filter element (10, 11). is,wherein the sensor element (122) is arranged in a position in which, based on geometry data of usable filter elements, it is contactable by one type of filter element as intended and not contactable by another type of filter element as intended, so that the sensor element identifies the type of filter element currently used. Filter system according to claim 1, wherein at least one of the housing parts (109, 110) has a centering contour (124) for radially fixing and radially sealing a filter element (10, 11) in the inserted state, and wherein the other of the housing parts (110, 109) has at least two radial guide contours (116, 118) which are arranged coaxially to each other at different axial heights, so that alternatively at least two different filter elements (10, 11) with different diameters and / or different axial lengths can be inserted into the filter housing (108) in such a way that the respective inserted filter element (10, 11) is held in a defined position in the radial direction and in the axial direction (L) and its clean side (50) is sealed against its raw side (52). Filter system according to claim 2, wherein one of the housing parts (109) has a support contour (114) for axial support and / or sealing by means of an end-face sealing surface (130) of an inserted filter element (10, 11) which surrounds the centering contour (124). Filter system according to claim 2 or 3, wherein the centering contour (124) has a radial sealing surface (128) for radial sealing between clean side (50) and raw side (52) in the installed state of at least one of the filter elements (10, 11), wherein the radial sealing surface (128) is formed on an outside of a central tubular pipe section (140) projecting into the housing interior (142). Filter system according to one of claims 2 to 4, wherein the centering contour (124) has at least two areas (132, 134) with different diameters on its tubular pipe section (140) projecting into the housing interior (142), wherein the area (134) with the smallest diameter is arranged axially inside, wherein preferably the centering contour (124) is formed in the transition area (136) between the at least two areas (132, 134) to support the weight of an inserted filter element (10, 11). Filter system according to one of claims 2 to 5, wherein a contact area (138) is provided radially outside the centering contour (124), through which a filter element (10, 11) with a suitable diameter can be radially fixed in the installed state. Filter system according to one of claims 2 to 6, wherein at least one first end disk (16) arranged on an end face (15) of a filter bellows (12) of the filter element of the other type, comprising a support element (20) and a radial seal (22), wherein the support element (20) is provided for intended interaction with a corresponding support contour (114) and the radial seal (22) for intended interaction with a centering contour (124) of the filter housing (108), and at least one second end disk (18) arranged on a second end face (17) of a filter bellows (12) with support elements (24), which are provided for intended interaction with a base (120) of the second housing part (110). Use of a filter element of one type for replacing the filter element of another type in a filter system according to one of claims 1-7, wherein the filter element of one type comprises at least one counter element (144) for interacting with at least one sensor element (122) in the filter housing (108) identifying the type and / or size of the filter element (10, 11), which actuates the sensor element (122). Use according to claim 8, wherein the at least one counter element (144) is preferably arranged in an end disk (16, 18). Use according to claim 8 or 9, wherein the at least one counter element (144) comprises a metallic element integrated into an end disk (16, 18) which is detectable by a sensor element (122) arranged on a filter housing (108). Use according to claim 8 or 9, wherein the at least one counter element (144) comprises information about at least the type and / or size of the filter element (10, 11) of one type in analog and / or digitally stored form, such that the information is detectable by a sensor element (122) arranged on a filter housing (108). Use according to any one of claims 8 to 11, wherein at least one first end disk (16) arranged on an end face (15) of a filter bellows (12) with a support element (20) and a radial seal (22), wherein the support element (20) is provided for intended interaction with a corresponding support contour (114) and the radial seal (22) for intended interaction with a centering contour (124) of the filter housing (108), and at least one second end disk (18) arranged on a second end face (17) of a filter bellows (12) with support elements (24) which are provided for intended interaction with a base (120) of the second housing part (110). Use according to one of claims 8 to 12, wherein the filter element of one type can be supported by the support element (20) on the support contour (114) and can be centered by the radial seal (22) on the centering contour (124) of the filter housing (108).

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