Filter element and method for producing a filter element

Abstract

A filter element (10) of a filter for fluid, in particular fuel, oil, water, urea solution or air, in particular of an internal combustion engine, in particular of a motor vehicle, and a method for producing the same are described. The filter element (10) comprises a filter medium (14), which is designed as a filter medium hollow body (12) and is circumferentially closed at least with respect to an imaginary axis (16). On at least one end face, the filter medium (14) comprises an end body (20). The end body (20) comprises a closing section (28), which is sealingly connected at least to the filter medium (14). Moreover, the end body (20) has a central fluid opening (24) into which a tube-like connecting element (38) of the filter can be inserted. At least one sealing section (30) is provided on the end body (20) for circumferentially sealing the fluid opening (24) with respect to the tube-like connecting element (38). The at least one sealing section (30) is integrally connected to the closing section (28) by way of at least one flexible joining section (32).

Claims

1. A filter element of a filter for fluid of a motor vehicle, comprising: a filter medium hollow body of a filter medium; wherein the filter medium hollow body is circumferentially closed radially surrounding an imaginary axis wherein at least one end face, comprises an end body, which includes an annular closing section having a first face arranged directly on and sealingly connected directly onto the filter medium on an axial end of the hollow body, a second face on a axially opposite side of the annular closing section from the first face; wherein the annular closing section has a central fluid opening extending through the annular closing section from the first face to the opposing second face of the annular closing section and into which a tube-like connecting element of the filter can be inserted; and a circumferentially closed annular sealing section arranged on the annular closing section on an outer circumference of the central fluid opening and surrounding the central fluid opening, at least one flexible joining section circumferentially surrounding the central fluid opening and connecting the circumferentially closed annular sealing section to the annular closing section; wherein the annular sealing section is integrally connected to the annular closing section by the at least one flexible joining section such that the annular sealing section is invertable through the central fluid opening from: a first state in which the annular sealing section is arranged at and projects axially outwardly from the second face of the annular closing section of the filter element, to a second state in which the annular sealing section is inverted through the central fluid opening and now is arranged at and projects axially from the first face of the annular closing section of the filter element, into the an inner chamber of the filter medium hollow body; wherein the circumferentially closed annular sealing section is configured for circumferentially sealing the central fluid opening with respect to the tube-like connecting element of the filter, when in the second state.

2. The filter element according to claim 1, wherein the end body having the annular closing section, the at least one flexible joining section and the circumferentially closed annular sealing section are formed together, forming a unitary one-piece blow-molded part.

3. The filter element according to claim 1, wherein the circumferentially closed annular sealing section can be axially inverted over the at least one joining section with respect to an axis of the sealing section.

4. The filter element according to claim 1, wherein the circumferentially closed annular sealing section: when in the first state, includes at least one sealing contour formed as an projecting ridge on a radial exterior of the circumferentially closed annular sealing section; and when in the second state, the at least one sealing contour is arranged on a radial interior of the circumferentially closed annular sealing section, the at least one sealing contour facing the tube-like connecting element.

5. The filter element according to claim 1, wherein when in the second state, the circumferentially closed annular sealing section is seated against at least one support section of the filter element which extends at least over a portion of the circumference with respect to the fluid opening of a support tube and/or the end body; wherein, when in the second state, the at least one support section is located on the side of the circumferentially closed annular sealing section located radially opposite the tube-like connecting element.

6. A filter element according to claim 1, wherein, when in the second state, the circumferentially closed annular sealing section is disposed in the inner chamber of the filter medium hollow body.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Additional advantages, features and details of the invention will be apparent from the description provided hereafter, which describes exemplary embodiments of the invention in more detail based on the drawings. A person skilled in the art will expediently also individually consider the features that are disclosed in combination in the drawings, the description and the claims and combine them to form useful further combinations. The schematic figures show:

(2) FIG. 1 is an isometric illustration of a round filter element of an air filter of an internal combustion engine of a motor vehicle according to a first exemplary embodiment, comprising a filter bellows, on the one end face of which a connecting end plate having a connecting opening and a sealing section for the connecting opening are attached, wherein the sealing section is disposed in an inner chamber of the filter bellows;

(3) FIG. 1A shows the connecting end plate of FIG. 1 in a first state in which the annular sealing section is arranged at and projects axially outwardly from the second face of the annular closing section of the connecting end plate of the filter element;

(4) FIG. 1B shows the connecting end plate of FIG. 1 in a second state in which the annular sealing section is inverted through the central fluid opening of the connecting end plate and now is arranged at and projects axially from the connecting end plate into the interior of the filter medium hollow body;

(5) FIG. 2 shows a detailed view of the connecting end plate of FIG. 1 in a pre-assembled state prior to installation on the filter bellows;

(6) FIG. 3 shows a longitudinal sectional view of the round filter element of FIG. 1;

(7) FIG. 4 shows a longitudinal sectional view of the connecting end plate in the pre-assembled state of FIG. 2; and

(8) FIG. 5 shows a longitudinal sectional view of a round filter element according to a second exemplary embodiment, which is similar to the round filter element of FIGS. 1 and 3, in which the sealing section is disposed on the outer side of the connecting end plate.

(9) In the figures, identical components are denoted by the same reference numerals.

DETAILED DESCRIPTION OF THE INVENTION

(10) FIGS. 1 and 3 show a filter element 10 of an air filter of an internal combustion engine of a motor vehicle. The filter element 10 can be disposed replaceably in a filter housing (not shown) of the air filter, so that it sealingly separates an air inlet of the filter housing from an air outlet.

(11) The filter element 10 is designed as a round filter element having a round cross-section. The filter element 10 comprises a filter bellows 12 made of a circumferentially closed filter medium 14 that is pleated in a zigzag manner. The filter medium 14 can be a non-woven filter, for example. In the overall, the filter element 10 has a coaxial design with respect to an imaginary axis 16. The radially inner circumferential sides of the filter bellows 12 and the radially outer circumferential sides are each located on an imaginary coaxial cylinder jacket with respect to the axis 16. The filter bellows 12 surrounds an inner chamber 18 of the filter element 10 in a circumferentially closed manner.

(12) A connecting end plate 20, which is sealingly connected to the filter medium 14, is disposed on an end face of the filter bellows 12. A counter end plate 22 is disposed on the other end face and likewise sealingly connected to the filter medium 14. The connecting end plate 20 and the counter end plate 22 are both made of plastic material. They are each joined to the filter medium 14 by way of an adhesive. As an alternative, the connecting end plate 20 and the counter end plate 22 could also be melted in each case and, for joining, the filter medium 14 can be pressed into the melted plates 20, 22.

(13) The counter end plate 22 is entirely closed and closes the inner chamber 18 at the corresponding end face of the filter bellows 12.

(14) The connecting end plate 20 has a central opening 24, which is coaxial with respect to the axis 16. The diameter of the opening 24 is slightly smaller than the radially inner diameter of the filter bellows 12 and a diameter of the inner chamber 18.

(15) A grid-shaped support tube 26 is disposed coaxially with respect to the axis 16 in the inner chamber 18 of the filter bellows 12. The support tube 26 is likewise made of plastic material, or also metal. The radially outer circumferential sides thereof are seated against the radially inner circumferential sides of the filter bellows 12, thereby supporting the same. The end faces of the support tube 26 are connected in each case to the connecting end plate 20 and the counter end plate 22. The support tube 26 as a whole allows air to pass through on the circumferential side. The support tube 26 is composed of a plurality of circumferentially extending circumferential struts, which are integrally connected by way of a plurality of axially extending axial struts.

(16) The connecting end plate 20, which is shown in FIGS. 2 and 4 in a pre-assembled state before installation on the filter bellows 12, comprises a closing section 28, a sealing section 30 and a flexible joining section 32, which are integrally connected to each other. The connecting end plate 20 comprising the sections 28, 30 and 32 is produced by way of a blow-molding method. It is made of a single plastic material.

(17) The closing section 28 has the shape of a round annular disk extending radially with respect to the axis 16. The closing section 28 has the opening 24. An end face thereof is connected to the end face of the filter bellows 12.

(18) The sealing section 30 has the shape of a cylinder jacket section. When the connecting end plate 20 is installed on the filter bellows 12, the sealing section 30 is coaxially disposed in the inner chamber 18 with respect to the axis 16. When installed, an axis of the sealing section 30 coincides with the axis 16 and, for the sake of improved clarity, is also denoted by reference numeral 16 in FIGS. 2 and 4.

(19) The sealing section 30 is connected to the radially inner circumferential side of the closing section 28 by way of the flexible joining section 32. The joining section 32 and the sealing section 30 are each circumferentially closed with respect to the axis 16. A radially outer circumferential side of the sealing section 30 is seated against the radially inner circumferential side of the support tube 26 when the connecting end plate 20 is installed. The support tube 26 thus supports the sealing section 30, thus forming a counter surface.

(20) The circumferential side of the sealing section 30, which is the radially inner side when the connecting end plate 20 is installed, comprises a sealing contour 34. The sealing contour 34 has a saw tooth-like profile. The sealing contour 34 comprises a plurality of ridges 36, which extend circumferentially with respect to the axis 16 and form the teeth of the saw tooth-like profile. The ridges 36 have a certain elasticity, which allows a sealing function with respect to a connector 38, which is indicated with dotted lines in FIG. 3, or a center tube of the filter housing. When the connecting end plate 20 is installed, the flanks of the ridges 36 facing away from the inner chamber 18 extend obliquely with respect to the axis 16, so that an insertion of the connector 38 into the opening 24, which is to say into the sealing section 30, is simplified. The opposing flanks of the ridges 36 facing the inner chamber 18 extend radially with respect to the axis 16, so that a removal of the connector 38 is made more difficult.

(21) In the pre-assembled state of the connecting end plate 20 prior to installation on the filter bellows 12, the sealing section 30 is located on the first face 52 of the outer side of the closing section 28, which is located opposite the filter bellows 12 which is attached to the second face 54 of the closing section 28 in the final installed state. In the pre-assembled state, the sealing contour 34 is disposed on the radially outer circumferential side of the sealing section 30. The sealing contour 36 is thus easy to implement according to the blow-molding method. The elasticity of the joining section 32 allows the sealing section 30 to be inverted from the pre-assembled state into the final installed state. During operation of the air filter, the air that is to be filtered flows through the filter bel-lows 12 from radially outward to radially inward. The air flow is indicated in FIG. 3 by arrows 40. The connector 38 of the filter housing is an outlet connector in the embodiment shown.

(22) To produce the filter element 10, initially the filter bellows 12, the connecting end plate 20, the counter end plate 22 and the support tube 26 are prefabricated as separate components.

(23) The support tube 26 is disposed in the inner chamber 18 of the filter bellows 12. The connecting end plate 20 and the counter end plate 22 are disposed on the end faces of the filter bellows 12 by means of interposed adhesive. Thereafter, the sealing section 30 is inverted axially with respect to the axis 16 over the joining section 32 into the inner chamber 18 of the filter bellows 12 out of the pre-assembled state on the outer side of the connecting end plate 20. After the adhesive has dried, the filter element 10 is ready for use.

(24) For installation in the filter housing, the filter element 10 is placed onto the connector 38 with the connecting end plate 20 first, wherein the connector extends through the opening 24 into the sealing section 30 into the inner chamber 18. The sealing contour 34 is then sealingly seated against the radially outer circumferential side of the connector 38.

(25) FIG. 5 shows a second exemplary embodiment of a filter element 110. The elements that are similar to those of the first exemplary embodiment from FIGS. 1 to 4 are denoted by the same reference numerals plus 100.

(26) The filter element 110 differs from the filter element 10 according to the first exemplary embodiment from FIGS. 1 to 4 in that a sealing section 130 is disposed on the outer side of the connecting end plate 20, instead of in the inner chamber 18.

(27) A support section 142 is disposed between the joining section 132 and the closing section 128. The support section 142 has the shape of a cylinder jacket that is coaxial with respect to the axis 116. It is mechanically stable. At one end face, the support section 142 is integrally connected to the closing section 128, and at the other end face, it is integrally connected to the sealing section 130. The support section 142 is located on the outer side of the closing section 128 facing away from the filter bellows 12. The axial extension of this section corresponds approximately to the axial extension of the sealing section 130. When installed, the radially outer circumferential side of the sealing section 130 is seated against the radially inner circumferential side of the support section 142. The support section 142 thus forms a counter surface for the sealing section 130 against the connector 138 of the filter housing.

(28) The sealing section 130 is also inverted axially over the joining section 132 with respect to the axis 16 in the second exemplary embodiment. In the pre-assembled state of the connecting end plate 120, which is not shown in the figures, the sealing contour 134 is seated against the radially outer circumferential side of the sealing section 130, analogously to the first exemplary embodiment, as shown in FIG. 4. The sealing section 130 is then not disposed inside the support section 142, but in the axial direction next to the same on the side located opposite the closing section 128.

(29) The filter element 110 is installed in the filter housing in a manner corresponding to the first exemplary embodiment of the filter element 10.

(30) In all the above-described exemplary embodiments of a filter element 10; 110 and of a method for producing a filter element 10; 110, the following modifications are possible, among other things.

(31) The invention is not limited to filter elements 10; 110 of air filters of motor vehicles. Rather, it can also be used in other filter elements, such as for fuel, oil, water or a urea solution. The filter can also be employed outside of motor vehicles, such as for industrial engines.

(32) The filter element 10; 110 can be also disposed in a fixed manner, instead of replaceably, in the filter housing.

(33) Instead of being a round filter element, the filter element 10; 110 can also be implemented as a different kind of filter element comprising a filter bellows designed as a hollow body. For example, the round filter element can have an oval cross-section instead of a round cross-section. It can also be a filter element having an angular cross-section. Instead of the filter medium being pleated in a zigzag-shaped manner, it is also possible to use a filter medium that is circumferentially closed in another manner, such as a foamed filter medium.

(34) Air can flow through the filter bellows 12; 112 from radially inward to radially outward, instead of from radially outward to radially inward. The connector 38; 138 in this case is an inlet connector.