Filter system and filter element
The filter system addresses the need for cost-effective variations by using coding elements and pins for filter elements, simplifying production and assembly, thus reducing labor and production costs.
Patent Information
- Application Number
- JP2024568340
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2022-05-18
- Filing Date
- 2023-05-12
- Publication Date
- 2025-05-20
AI Technical Summary
Existing filter systems lack cost-effective variations and efficient coding mechanisms for filter elements, leading to increased labor and production costs due to interchangeable inserts and tooling changes.
A filter system with a housing and filter element featuring a filter bellows, where coding elements on the end cap and coding pins in the housing interact through angled recesses and slots to ensure proper alignment, allowing for multiple variations without requiring tooling changes.
This design reduces labor hours and costs by enabling production of various filter elements with the same tooling, minimizing stock levels and shortening delivery times, while ensuring correct assembly and reducing manufacturing complexity.
Smart Images
Figure 2025515927000001_ABST
Abstract
Description
[Technical field]
[0001] The present invention relates to a filter system, in particular for air filter applications, comprising a housing having an inlet and an outlet, and a filter element housed in the housing along an axial direction for filtering a fluid flowing from the inlet to the outlet, and the filter element comprises a filter bellows. [Background technology]
[0002] WO 2020 / 014141 discloses a filtration system including a housing having a first housing end and a second housing end. The housing defines a central chamber therein. The housing includes an alignment tab disposed at the second housing end. The alignment tab projects from the second housing end toward the first housing end. A filter element is disposed within the housing. The filter element includes a first end cap, a second end cap, and a filter medium disposed between the first end cap and the second end cap and extending axially between the first end cap and the second end cap. The filter medium defines an axially extending central opening therein. The second end cap is provided with an alignment notch projecting from the second end cap toward the first end cap.
[0003] U.S. Patent No. 9,718,019 discloses an air cleaner device including an air cleaner housing and a serviceable air filter cartridge. The air cleaner housing includes an air inlet arrangement and an air outlet arrangement. The air cleaner housing defines a housing interior and is comprised of a housing body and an access cover. A protrusion / recess arrangement is provided including first and second members. One member of the protrusion / recess arrangement is disposed on the access cover. The other member of the protrusion / recess arrangement is disposed on an outer end surface of an end cap of the filter cartridge. In general, the first and second members of the protrusion / recess arrangement are engaged to provide a cantilever support of the air filter cartridge at the second end. Additionally, the first and second members of the protrusion / recess arrangement are non-rotatably engaged. Summary of the Invention
[0004] SUMMARY OF THE PRESENT EMBODIMENT An object of the present invention is to provide a cost-effective filter system having many variations.
[0005] It is a further object of the present invention to provide filter elements for such filter systems that are available in a cost-effective variety of variations.
[0006] The above object is achieved, according to one aspect of the invention, by a filter system comprising a housing having an inlet and an outlet, and a filter element for filtering a fluid flowing from the inlet to the outlet, accommodated in the housing along an axial direction, the filter element comprising a filter bellows having a first end face and an axially opposite second end face, at least one of the end faces being provided with an end cap, the at least one end cap being provided with a recess on the outside of the first end face, the recess extending in the axial direction, the at least one end cap being provided with at least one coding element arranged on its outer circumference, and the at least one end cap being provided with at least one coding element arranged on the inside of a bottom housing part of the housing, a coding pin is arranged in the bottom housing part, the coding pin being configured to cooperate with the recess when the filter element is inserted into the housing, the bottom housing part comprises a circular shield arranged coaxially with the filter element, the shield having an axially extending slot, the slot being configured to accommodate the coding element of the filter element when the filter element is inserted into the housing, and a filter system is achieved in which, with respect to the axial direction, a first angle between the angular position of the coding element of the filter element and the angular position of the recess corresponds to a second angle between the angular position of the slot of the bottom housing part and the coding pin.
[0007] A further object is achieved according to a further aspect of the invention by a filter element comprising a filter bellows having a first end face and an axially opposite second end face, at least one of the end faces being provided with an open end cap. This filter element is adapted to be used in a filter system according to the first aspect of the invention. At least one end cap is provided on the outside of the first end face with an axially extending recess for cooperating in the intended use with a coding pin of a housing of the filter system. At least one coding element is arranged on the outer periphery of the at least one end cap for cooperating in the intended use with a slot of a circular shield of a bottom housing part of the filter system. A first angle between the angular position of the coding element of the filter element and the angular position of the recess corresponds, respectively with respect to the axial direction, to a second angle between the angular position of the slot of the bottom housing part and the angular position of the coding pin of the filter system. The coding element is arranged axially spaced from the first end face, preferably at a predefined distance. The total axial length of the coding element is in particular significantly smaller than the axial length of the filter bellows.
[0008] Advantageous embodiments and advantages of the invention emerge from the further claims, the description and the drawings.
[0009] According to a first aspect of the invention, a filter system is proposed, comprising a housing having an inlet and an outlet, and a filter element for filtering a fluid flowing from the inlet to the outlet, accommodated in the housing along an axial direction. The filter element comprises a filter bellows having a first end face and an axially opposite second end face, at least one of the end faces being provided with an end cap. The at least one end cap is provided with an axially extending recess on the outer side of the first end face. At least one coding element is arranged on the outer periphery of the at least one end cap. At least one coding pin is arranged on the inner side of a bottom housing part of the housing, the coding pin being configured to cooperate with the recess when the filter element is inserted into the housing. The bottom housing part comprises a circular shield arranged coaxially with the filter element, the shield having an axially extending slot, the slot being configured to accommodate the coding element of the filter element when the filter element is inserted into the housing. A first angle between the angular position of the coding element of the filter element and the angular position of the recess corresponds to a second angle between the angular position of the slot of the bottom housing part and the angular position of the coding pin, each with respect to the axial direction.
[0010] Advantageously, in a hollow cylindrical filter element, a recess is provided radially on the outside of the end face of the filter element. Advantageously, the recess is wedge-shaped. Advantageously, the recess penetrates axially through the seal and / or the end plate, and possibly also partially into the filter bellows. In case of penetrating the seal, the penetration is preferably partial so that a distance remains between the penetration and the sealing surface. The end cap can be fitted with a crown-shaped circumferential ring consisting of a number of protrusions or serrations, preferably equally spaced apart. The profile of the serrations can be designed so that a separate coding element, for example a radially projecting cam, can be removably or non-removably connected to the crown, for example by means of a snap-in connection. The protrusions on which the coding elements are mounted determine the angle between the recess and the angular position of the coding element. The number of available protrusions allows for an increased variation of the coding.
[0011] Advantageously, a coding element, preferably a coding pin, is attached to the inside of the bottom housing part. The design and size of the coding pin corresponds to the recess of the filter element and matches its shape. The coding pin is preferably a separate part and can be attached at a predefined point in any angular position, for example by ultrasonic welding to form a welded joint. Furthermore, the bottom housing part has an axially upright circumferential shield having a predefined distance to the outside diameter of the filter element. This shield is provided with vertical slots corresponding to the coding element of the filter element. Depending on the bolt position at which the coding element is attached, the angle between the coding element and the shield slot is determined.
[0012] If the angle between the coding element and the recess and the angle between the coding pin and the shield slot are the same, the filter element can be inserted into the bottom housing part. If the angles are different, the filter element cannot be attached. By changing the coding angle, new filter variations are created.
[0013] Compared to the prior art, the coding, i.e. the interface between the housing of the filter system and the end cap of the filter element, is not located in the radial center but on the outside of the filter element, and the contour of the interface is not rotationally symmetric. A further difference is that the coding engages not only the seal and the end cap, but also the filter body.
[0014] Advantageously, the coding comprises at least two elements arranged on the outside of the filter element and spatially separated by a predetermined angle, so that multiple variations of the filter system and filter element can be coded as separate variations.
[0015] Therefore, the elimination of interchangeable inserts, changeovers and tooling changes reduces labor hours and reduces the overall cost of offering many variations simultaneously.
[0016] The coding elements and coding pins are interchangeable coding elements, so that different variations can be produced with the same tool and the same part.
[0017] By using coding elements that differ in design, size, etc., the coding variations can be multiplied many times.
[0018] Filter systems can be manufactured in small quantities in various variants without major production efforts. Since the same single parts are always used, high stock levels at the production plant are not an issue and delivery times for new variants to customers can be shortened.
[0019] Advantageously, differently coded filter elements and housings can be provided based on the same filter element and filter housing design without the need for expensive tooling changes after market launch.
[0020] The complexity of the manufacturing process does not increase as the number of filter variations increases.
[0021] Advantageously, variations are not created until the final manufacturing step, reducing the risk of assembling the wrong part for a particular variation during the manufacturing chain.
[0022] Each new variation remains the same product in terms of numbers, parts list etc., just with a different coding angle, reducing development, warehousing and logistics effort and costs.
[0023] Preferably, a bolt circle is arranged at least partially in the circumferential direction about the axial direction on the bottom housing part for receiving the coding pin in the bottom housing part, whereby the coding pin can be advantageously arranged in a predefined angular position for coding the bottom housing part accordingly.
[0024] Preferably, the at least one coding pin is permanently connected to the bottom housing part, in particular by welding or gluing. Additionally or alternatively, the at least one coding pin may form an integral part with the bottom housing part, whereby variations in the filter system are fixed and defects due to incorrect filter elements being fitted to the housing of the filter system can be excluded.
[0025] Preferably, the recess of the filter element extends at least partially into the filter bellows. In particular, the recess of the filter bellows can be produced by cutting the filter bellows, in particular by laser cutting the filter bellows, or by unfolding the pleats of the filter bellows. This advantageously allows a reliable coding of the filter element to be achieved. However, alignment of the filter element during the mounting process in the housing is facilitated.
[0026] Preferably, the at least one coding element is non-detachably connected to the end cap. Additionally or alternatively, the at least one coding element may form an integral part with the at least one end cap. Advantageously, the coding element is fixed to the filter element in such a way that it cannot become loose or lost during handling of the filter element from stock or during transportation for maintenance.
[0027] Preferably, in an embodiment of the filter system, at least one end cap is provided with an at least partially circumferentially extending circumferential ring, which provides a plurality of fastening elements, particularly preferably equally spaced fastening elements, for accommodating at least one coding element at the at least one end cap. In particular, the at least one coding element can be connected to the fastening elements of the circumferential ring by a snap-in connection. This advantageously allows the coding element to be arranged in a predefined angular position on the outer circumference of the filter element, ensuring a proper encoding of the filter element.
[0028] Preferably, the at least partially extending circumferential ring forms an integral part with the central tube of the filter element, which allows easy production of the filter element at low cost and requires fewer steps to mount the filter element. However, other options are possible, such as a detachable or non-detachable connection between the at least partially extending circumferential ring and the central tube of the filter element, or the at least partially extending circumferential ring and the central tube of the filter element being separate, unconnected parts.
[0029] Preferably, an at least partially extending circumferential ring is molded into at least one end cap, and preferably the center tube is also molded into the same end cap.
[0030] Preferably, at least one coding element forms an integral part with the central tube of the filter element, which allows for easy production of the filter element at low cost and requires fewer steps to attach the filter element.
[0031] According to a further aspect of the invention, a filter element is proposed, comprising a filter bellows having a first end face and an axially opposite second end face, at least one of the end faces being provided with an open end cap. This filter element is adapted to be used in a filter system according to the first aspect of the invention. At least one end cap is provided on the outside of the first end face with an axially extending recess for cooperating in the intended use with a coding pin of the housing of the filter system. At least one coding element is arranged on the outer periphery of the at least one end cap for cooperating in the intended use with a slot of a circular shield of the bottom housing part of the filter system. A first angle between the angular position of the coding element of the filter element and the angular position of the recess corresponds, respectively with respect to the axial direction, to a second angle between the angular position of the slot of the bottom housing part and the angular position of the coding pin of the filter system. The coding element is arranged axially spaced from the first end face, preferably at a predefined distance. The total axial length of the coding element is in particular significantly smaller than the axial length of the filter bellows.
[0032] In some embodiments, the coding element may be disposed on an exterior shell surface of the filter bellows.
[0033] In some embodiments, the coding element can be spaced axially a predetermined distance from the free end of the first end cap.
[0034] By "open end cap" in this specification is meant that the end body has at least one opening, in particular a central opening, through which a fluid to be cleaned can be supplied to the filter bellows, in particular to the internal hollow space at least partially surrounded by the filter bellows, or a cleaned fluid can be supplied from the filter bellows.
[0035] Advantageously, in hollow cylindrical filter elements, a preferably wedge-shaped recess is provided radially on the outside of the end face of the filter element, which advantageously penetrates axially through the seal and / or the end plate and possibly also partially into the filter bellows. In case of penetrating the seal, the penetration is preferably partial so that a distance remains between the penetration and the sealing surface. The end cap can be fitted with a crown-shaped circumferential ring consisting of a number of protrusions or serrations, preferably equally spaced apart. The contour of the serrations can be designed so that a separate coding element, for example a radially projecting cam, can be removably or non-removably connected to the crown, for example by means of a snap-in connection. The protrusion on which the coding element is attached determines the angle between the recess and the angular position of the coding element. The number of available protrusions allows for an increased variation of the coding.
[0036] The proposed filter element can be advantageously used in the above mentioned filter system, so as to obtain a defined coding between the filter element and the housing of the filter system. Advantageously, the coding comprises two elements, a recess of the filter element and a coding element, which are arranged on the outside of the filter element and are spatially separated by a predefined angle. This allows many variations of the filter system and the filter element to be coded as separate variations.
[0037] Preferably, the recess of the filter element extends at least partially into the filter bellows. In particular, the recess of the filter bellows can be produced by cutting the filter bellows, in particular by laser cutting the filter bellows, or by unfolding the pleats of the filter bellows. This advantageously allows a reliable coding of the filter element to be achieved. However, alignment of the filter element during the mounting process in the housing is facilitated.
[0038] Preferably, the at least one coding element is non-detachably connected to the end cap and / or forms an integral part with the at least one end cap. Advantageously, the coding element is fixed to the filter element and cannot become loose or lost during handling of the filter element from inventory or during transportation for maintenance.
[0039] Preferably, at least one end cap is provided with an at least partially circumferentially extending circumferential ring, which provides a plurality of fastening elements, particularly preferably equally spaced, for accommodating at least one coding element at the end cap. In particular, the at least one coding element can be connected to the fastening elements of the circumferential ring by a snap-in connection. This advantageously allows the coding element to be arranged in a predefined angular position on the outer circumference of the filter element, ensuring a proper encoding of the filter element.
[0040] Preferably, the at least partially extending circumferential ring forms an integral part with the central tube of the filter element, which allows easy production of the filter element at low cost and requires fewer steps to mount the filter element. However, other options are possible, such as a detachable or non-detachable connection between the at least partially extending circumferential ring and the central tube of the filter element, or the at least partially extending circumferential ring and the central tube of the filter element being separate, unconnected parts.
[0041] Preferably, at least one coding element forms an integral part with the central tube of the filter element, which allows for easy production of the filter element at low cost and requires fewer steps to attach the filter element.
[0042] Further advantages are obtained from the following description of the drawings, in which embodiments of the invention are shown. The drawings, the description and the claims contain a number of features in combination, which the person skilled in the art can consider individually and combine to provide further combinations. [Brief description of the drawings]
[0043] [Figure 1] FIG. 1 is an isometric exploded view of a filter system according to one embodiment of the present invention. [Diagram 2] FIG. 2 is another isometric exploded view of the filter system of FIG. 1. [Diagram 3] FIG. 2 is an isometric view of a filter element according to one embodiment of the present invention. [Figure 4] FIG. 1 is an isometric view of a coding element of a filter element. [Diagram 5] FIG. 2 is an isometric view of a bottom housing portion of the filter system of FIG. 1. [Figure 6] FIG. 2 is an isometric view of the coding pin of the bottom housing part of the filter system. [Figure 7] FIG. 2 is a side view of the filter system of FIG. 1, shown at cross section AA. [Figure 8] FIG. 2 is a top view of the filter system at cross section AA, with cross section CC shown. [Figure 9] FIG. 2 is another top view of the filter system. [Figure 10] FIG. 2 is a side view of the filter system at cross section CC. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0044] In the drawings, like elements are provided with the same reference numbers. The drawings are merely schematic representations and are not intended to depict specific parameters of the invention. Also, the drawings are intended to depict only typical embodiments of the invention and should not be considered as limiting the scope of the invention.
[0045] 1 and 2 are isometric exploded views in two different views of a filter system 100 according to an embodiment of the present invention. Filter system 100 can be used, inter alia, for air filtration, for example in industrial applications.
[0046] The filter system 100 comprises a housing 110 having an inlet 102 and an outlet 108. Only a bottom housing part 112 in which the inlet 102 and the outlet 108 may be located is shown. A top housing part for tightly closing the housing 110 is omitted. The filter system 100 further comprises a filter element 10 housed in the housing 110 along an axial direction L for filtering a fluid, typically air, flowing from the inlet 102 to the outlet 108.
[0047] FIG. 3 is an isometric view of a filter element 10 according to an embodiment of the present invention.
[0048] The filter element 10 includes a filter bellows 12 having a first end face 14 and an opposite second end face 16 along an axial direction L. Both ends 14, 16 are provided with end caps 18, 20 for secure mounting and sealing to a housing 110. The end caps 18, 20 are typically made from a sealing material, preferably an elastomer, such as an expanded polyurethane (PUR) material. The filter bellows 12 is typically made from a pleated filter medium.
[0049] 3, the first end cap 18, which is the open end cap 18, is provided with a recess 30 on the outer side 22 of the first end face 14, extending in the axial direction L. The recess 30 of the filter element 10 extends partially into the filter bellows 12. In particular, the recess 30 in the filter bellows 12 can be formed by cutting the filter bellows 12, in particular by laser cutting the filter bellows 12. Alternatively, the recess 30 can be formed by unfolding the pleats of the filter bellows 12.
[0050] A coding element 32 is arranged on the outer periphery 24 of the open end cap 18. The coding element 32 is arranged at a predetermined distance in the axial direction L from the first end face 14. The distance between the proximal end of the coding element 32 facing the first end face 14 and the first end face 14 can be, for example, in the range of 5% to 25% of the total length of the filter bellows 12 in the axial direction L, in particular in the range of 7% to 15% of the total length of the filter bellows 12 in the axial direction L.
[0051] For this purpose, an at least partially circumferentially extending circumferential ring 34 is arranged on the end cap 18. The circumferential ring 34 provides the end cap 18 with a plurality of fastening elements 36, particularly preferably equally spaced fastening elements 36, for accommodating the coding elements 32. In particular, the coding elements 32 can be connected to the fastening elements 36 of the circumferential ring 34, for example by means of a snap-in connection.
[0052] In another embodiment, the at least partially extending circumferential ring 34 may form an integral part with a central tube 38 of the filter element 10. The central tube 38, which supports the filter bellows 12, is located inside the filter element 10 and is shown in Figures 2 and 3.
[0053] 4 shows an isometric view of the coding element 32 of the filter element 10. The coding element 32 is provided with an opening 42 for attaching the coding element 32 to the fastening element 36 of the circumferential ring 34. The coding element 32 can be permanently fastened to the fastening element 36 by welding or gluing. A snap-in connection is also possible.
[0054] The coding element 32 may be non-removably connected to the end caps 18,20.
[0055] In an alternative embodiment, the coding element 32 may be formed directly as an integral part with the end cap 18 .
[0056] In a further alternative embodiment, the coding element 32 may be formed directly as an integral part with the central tube 38 of the filter element 10 .
[0057] FIG. 5 is an isometric view of the bottom housing portion 112 of the filter system 100 of FIG.
[0058] A coding pin 130 is arranged on the inside 114 of the bottom housing part 112 of the housing 110. The coding pin 130 is configured to cooperate with the recess 30 when the filter element 10 is inserted into the housing 110.
[0059] For receiving the coding pin 130 in the bottom housing part 112 , a bolt circle 134 is at least partially arranged in the circumferential direction about the axial direction L in the bottom housing part 112 .
[0060] 6 is an isometric view of the coding pin 130. Preferably, the coding pin 130 is non-detachably connected to the bottom housing part 112, in particular by welding or gluing.
[0061] In an alternative embodiment, the coding pin 130 may form an integral part with the bottom housing portion 112 .
[0062] 1 and 5, the bottom housing portion 112 further includes a circular shield 116 disposed coaxially with the filter element 10. The shield 116 is used to protect the filter bellows 12 from particles in the fluid entering the inlet 102, for example.
[0063] The shield 116 in the illustrated embodiment has a slot 132 extending in the axial direction L. The slot 132 is configured to receive the coding element 32 of the filter element 10 when the filter element 10 is inserted into the housing 110.
[0064] FIG. 7 is a side view of the filter system 100 of FIG. 1 taken along cross section AA.
[0065] 7, filter element 10 is shown in its intended position in bottom housing portion 112. In this view, distance 118 between shield 116 and diameter 26 of filter element 10 is shown.
[0066] FIG. 8 is a top view of filter system 100 at section AA of FIG. 7, with section CC shown.
[0067] The top view clearly shows the cooperation of the coding element 32 of the filter element 10 with the slot 132 of the shield 116 of the bottom housing part 112, and the cooperation of the coding pin 130 of the bottom housing part 112 with the recess 30 of the filter element 10, when the filter element 10 is in its intended position in the bottom housing part 112.
[0068] This cooperation is highlighted in Fig. 9, in which another top view of the filter system 100 is shown. Here, it can be seen that the first angle 40 between the angular position of the coding element 32 and the angular position of the recess 30 of the filter element 10, with respect to the axial direction L, coincides with the second angle 140 between the angular position of the slot 132 and the coding pin 130 of the bottom housing part 112. This coincidence is a requirement for the filter element 10 with defined recess 30 and coding element 32 to be inserted in the correct position into the bottom housing part 112 with defined coding pin 130 and slot 132.
[0069] If the angle 40 between the coding element 32 and the recess 30 and the angle between the coding pin 130 and the shield slot 132 are the same, the filter element 10 can be inserted into the bottom housing part 112. If the angles 40, 140 are different, the filter element 10 cannot be installed. By changing the coding angles 40, 140 new filter variations are created.
[0070] In the illustrated embodiment, the angle between the coding element 32 and the recess 30 and the angle between the coding pin 130 and the shield slot 132 are each 78°.
[0071] Figure 10 is a side view of filter system 100 at section CC of Figure 8, showing filter element 10 attached to the bottom of bottom housing part 112 when it is in its final position within housing 110 for intended use of filter system 100, and housing 110 is closed by a top housing part, not shown. [Explanation of symbols]
[0072] 10 Filter Elements 12 Filter Bellows 14 End face 16 End face 18 End Cap 20 End Cap 22 Outside 24 Outer circumference 26 diameter 30 Recess 32 Coding Elements 34 Ring 36 Fixed elements 38 Central canal 40 First Angle 42 Opening 100 Filter System 102 Inlet 108 Outlet 110 Housing 112 Bottom housing part 114 Inside 116 Circular Shield 118 distance 130 coding pin 132 Slots 134 Volts Yen 140 Second Angle L axis direction
Claims
1. A filter system (100) comprising: a housing (110) having an inlet (102) and an outlet (108); and a filter element (10) housed within the housing (110) along an axial direction (L) for filtering a fluid flowing from the inlet (102) to the outlet (108), The filter element (10) includes a filter bellows (12) having a first end face (14) and an opposing second end face (16) along the axial direction (L), at least one of the end faces (14, 16) being provided with an end cap (18, 20); At least one of the end caps (18, 20) is provided with a recess (30) on an outer side (22) of the first end face (14), the recess (30) extending in the axial direction (L); At least one coding element (32) is disposed on an outer periphery (24) of the at least one end cap (18, 20); At least one coding pin (130) is arranged on the inside (114) of the bottom housing part (112) of the housing (110), the coding pin (130) being configured to cooperate with the recess (30) when the filter element (10) is inserted into the housing (110), the bottom housing part (112) comprises a circular shield (116) arranged coaxially with the filter element (10), the shield (116) having a slot (132) extending in the axial direction (L), the slot (132) configured to receive the coding element (32) of the filter element (10) when the filter element (10) is inserted into the housing (110); A filter system, wherein a first angle (40) between an angular position of the coding element (32) and an angular position of the recess (30) of the filter element (10), each with respect to the axial direction (L), corresponds to a second angle (140) between an angular position of the slot (132) and an angular position of the coding pin (130) of the bottom housing part (112).
2. 2. The filter system of claim 1, wherein a bolt circle (134) is at least partially disposed in the bottom housing part (112) in a circumferential direction about the axial direction (L) for receiving the coding pin (130) in the bottom housing part (112).
3. 3. A filter system according to claim 1 or 2, wherein the at least one coding pin (130) is non-detachably connected to the bottom housing part (112), in particular by welding or gluing, and / or the at least one coding pin (130) forms an integral part with the bottom housing part (112).
4. 4. The filter system according to claim 1, wherein the recess (30) of the filter element (10) extends at least partially into the filter bellows (12), in particular the recess (30) of the filter bellows (12) is formed by cutting the filter bellows (12), in particular by laser cutting the filter bellows (12) or by unfolding the pleats of the filter bellows (12).
5. The filter system according to any one of claims 1 to 4, wherein the at least one coding element (32) is non-detachably connected to the at least one end cap (18, 20) and / or forms an integral part with the at least one end cap (18, 20).
6. 6. A filter system according to claim 1, wherein a circumferential ring (34) is arranged on the at least one end cap (18, 20) extending at least partially in the circumferential direction, the circumferential ring (34) providing a plurality of fastening elements (36), particularly preferably equally spaced fastening elements (36), for accommodating the at least one coding element (32) on the at least one end cap (18, 20), in particular the at least one coding element (32) being connected to the fastening elements (36) of the circumferential ring (34) by means of a snap-in connection.
7. The filter system of claim 6, wherein said at least partially circumferentially extending circumferential ring (34) forms an integral part with a central tube (38) of said filter element (10).
8. The filter system according to any one of the preceding claims, wherein the at least one coding element (32) forms an integral part with a central tube (38) or with an at least partially circumferentially extending circumferential ring (34) of the filter element (10).
9. A filter element (10) for a filter system (100) according to any one of claims 1 to 8, comprising a filter bellows (12) having a first end face (14) and an opposing second end face (16) along an axial direction (L), at least one of said end faces (14, 16) including an open end cap (18, 20); At least one of the end caps (18, 20) is provided on an outer side (22) of the first end face (14) with at least one recess (30) for cooperating with a coding pin (130) of a housing (110) of the filter system (100) in intended use, the recess (30) extending in the axial direction (L); at least one coding element (32) is disposed on an outer periphery (24) of the at least one end cap (18, 20) for cooperating with a slot (132) of a circular shield (116) of a bottom housing portion (112) of the filter system (100) in intended use; the coding element (32) is spaced from the first end face (14) in the axial direction (L); A filter element, wherein a first angle (40) between an angular position of the coding element (32) of the filter element (10) and an angular position of the recess (30), each with respect to the axial direction (L), corresponds to a second angle (140) between an angular position of the slot (132) of the bottom housing part (112) and an angular position of a coding pin (130) of the filter system (100).
10. 10. The filter element according to claim 9, wherein the recess (30) of the filter element (10) extends at least partially into the filter bellows (12), in particular the recess (30) of the filter bellows (12) is formed by cutting the filter bellows (12), in particular by laser cutting the filter bellows (12) or by unfolding the pleats of the filter bellows (12).
11. 11. The filter element according to claim 9 or 10, wherein the at least one coding element (32) is non-detachably connected to the at least one end cap (18, 20) and / or forms an integral part with the at least one end cap (18, 20).
12. 12. A filter element according to any one of claims 9 to 11, in which a circumferential ring (34) is arranged on the at least one end cap (18, 20) extending at least partially in the circumferential direction, which circumferential ring (34) provides a plurality of fastening elements (36), particularly preferably equally spaced fastening elements (36), for accommodating the at least one coding element (32) at the end cap (18, 20), in particular the at least one coding element (32) being connected to the fastening elements (36) of the circumferential ring (34) by means of a snap-in connection.
13. The filter element of claim 12, wherein the at least partially circumferentially extending circumferential ring (34) forms an integral part with a central tube (38) of the filter element (10).
14. The filter element according to any one of claims 9 to 13, wherein the at least one coding element (32) forms an integral part with a central tube (38) or with an at least partially circumferentially extending circumferential ring (34) of the filter element (10).