Exchangeable filter insert

p0001The invention relates to a replaceable filter insert for a filter with the features according to the preamble of claim 1.

State of the art

p0002In motor vehicles and industrial motors, various filters are used, in which the filter insert is designed separately from the filter housing. For example, the oil filter has a filter housing which can be divided along a separating surface, two housing parts of the filter housing being sealed against one another along the separating surface by means of a seal. One of the two housing parts is designed as a cover part and is released for replacing the filter insert. When replacing the filter insert in the prescribed maintenance intervals, the seal of the two housing parts must also be replaced.

p0003In practical operation it is observed that the exchange of the housing seal is neglected. The old seal may be re-used after replacing the filter insert, which can lead to leaks in the filter housing. Often an incorrect seal is used or the seal is completely forgotten. As a result, oil loss occurs. Consequential damage, in particular engine damage, can not be excluded.

p0004The possibilities of a faulty maintenance in the area of ​​the oil filter are further extended by the fact that incorrect, only insufficiently suitable filter inserts or insufficient quality requirements can be used. These reduce the filtration result and can lead to premature engine wear or even to serious engine damage.

p0005The object of the invention is to provide a replaceable filter insert with improved maintenance safety.

p0006This object is achieved by a filter insert having the features of claim 1.

Disclosure of the invention

p0007A replaceable filter insert is proposed, on which the seal is held displaceable and captive in the axial direction. In particular, the seal comprises a bearing ring surrounding the filter insert with a sealing ring, the circumferential bearing ring being provided on the inside with at least one securing edge with respect to a radial direction, and the filter insert being provided with an end stop, especially in the form of an end disk, The securing edge. The captive holding of the seal on the filter insert results in the removal of the filter insert from the filter housing, the seal for the two housing parts is also removed and can not be reused. The new, similar filter insert carries the captively held seal, which is brought into position when the new filter insert is inserted. The new seal can not be forgotten. The axial displaceability of the seal allows the filter insert to be positioned without interfering with the seal. Regardless of the position of the filter insert, the seal can be brought into its intended mounting position. In particular, it is possible to use the same filter insert in different filter housings with differently positioned separating planes. By axial displacement, the seal can be brought into different mounting positions. In an advantageous further development of the filter insert in a mirror-symmetrical version, the installation orientation of the filter insert does not depend on. For ease of handling, the user can insert the filter cartridge into the housing in any direction by sliding the seal into the appropriate axial position.

p0008In a preferred embodiment, the filter insert comprises a filter body, especially of filter paper, with folds extending in the axial direction. The bearing ring of the seal has radially inner teeth for the formation of the securing edges, whereby the teeth engage between the folds. The end discs of the filter insert need not have a larger diameter than the actual filter body, since the end stops formed by them for the teeth of the bearing ring lie in the recesses formed by the folds. The arrangement is easy to mount and compact. The teeth slide axially along the folds in the axial direction but, if necessary, form an anti-twist device for the seal.

p0009In a preferred embodiment, the number of folds and teeth is the same. It may also be expedient for the number of folds to be an integer multiple of the number of teeth. When the bearing is axially pushed, the teeth distributed evenly over the circumference are each provided with a suitable axial depression between two radially outwardly extending folds, which are distributed evenly over the circumference, without the filter body having to be deformed. In addition to easy assembly, free axial displaceability is also ensured.

p0010In an expedient alternative, the end disk has at least one nose projecting in the radial direction, which overlaps the securing edge of the carrier ring, which in particular is designed as a circular inner edge, in the radial direction. The arrangement can be used, in particular, in the case of wound filters without axially extending folds, but can also be used with filter bodies with folds. A geometrical intersection of the carrier ring with the filter body is not necessary since the securing function of the end stops is taken over by the one or more radially protruding lugs. Filter body and tragring can be designed freely.

p0011In an expedient development, the circulating supporting ring is provided with flow-permeable openings. Irrespective of the axial displacement position of the seal, an unhindered axial propagation of the medium to be filtered is ensured.

p0012The encircling, in particular planar, supporting ring is advantageously at least substantially rigid in the radial direction. In this way, it is able to exert a supporting effect on the sealing ring in the radial direction, as a result of which the sealing ring is pressed against at least one of the housing parts in the radial direction. The sealing effect is increased.

BRIEF DESCRIPTION OF THE DRAWINGS FIG

p0013Exemplary embodiments of the invention are described in more detail below with reference to the drawing. Show it:

p0014<figref idrefs="f0001">FIG</figref> 2 shows a schematic longitudinal sectional view of a filter with an inserted filter insert designed according to the invention on which a seal for the filter housing is held axially displaceable and captive;

p0015<figref idrefs="f0002">FIG</figref> 3 shows a perspective view of the seal executed as a separate individual part <figref idrefs="f0001">FIG</figref> With details of their support and their teeth formed as teeth;

p0016<figref idrefs="f0002">FIG</figref> 4 a perspective view of the replaceable filter insert according to FIG <figref idrefs="f0001">FIG</figref> With details of its folded filter body and the seal guided axially between the folds <figref idrefs="f0002">FIG</figref>;

p0017<figref idrefs="f0003">FIG</figref> A schematic end view of a further exemplary embodiment with radially protruding lugs of the end disc for forming longitudinal stops,

p0018<figref idrefs="f0004">FIG. 4a</figref> Shows an alternative of a filter insert with a housing seal,

p0019<figref idrefs="f0004">FIG. 4b</figref> Shows a detail representation of the <figref idrefs="f0004">FIG. 4a</figref> Shown.

Embodiment of the invention

p0020<figref idrefs="f0001">FIG</figref> 12 shows a filter for motor vehicles or industrial engines in a schematic longitudinal sectional view. In the illustrated exemplary embodiment, an oil filter is provided for the lubrication oil circuit of a motor vehicle motor. It is also possible to use a different oil filter, for example for a hydraulic oil circuit as well as a fuel, water, coolant or air filter of motor vehicles or industrial motors.

p0021The filter comprises a filter housing 3 which is essentially rotationally symmetrical with respect to a central axis 21, as well as a replaceable filter insert 1, which is held in the filter housing 3. For the removal or insertion of the replaceable filter insert 1, the filter housing 3 is arranged along a separating surface 2 transverse or perpendicular to the central axis 21 divisible. For this purpose, the filter housing 3 has a lower housing part 4, which is fixedly connected to the internal combustion engine or its oil circuit. A further housing part 5 of the filter housing 3 forms a cover which closes the interior of the lower housing part 4 and which is detachably connected to the lower housing part 4 in the region of the separating surface 2.

p0022The filter insert 1 extends in an axial direction 18 extending parallel to the central axis 21 and is essentially cylindrical. In the assembled state, the filter insert 1 is axially parallel to the likewise essentially cylindrical filter housing 3 in its closed interior space. A schematically indicated, grid-like central tube 24, which centers and supports the filter insert 1, is provided axially parallel to the central axis 21.

p0023The filter insert 1 has a substantially cylindrical, in FIG <figref idrefs="f0002">FIG</figref> In which two end plates 12, 13 located in the axial direction 18 are each fixed in a flow-tight manner. Between the two end disks 10, the filter body 19 is surrounded by an annular seal 6. The seal 6 comprises a carrier ring 7, which surrounds the filter insert 1, with a sealing ring 8 which is arranged around the filter insert 1 and is also circumferentially arranged with respect to a radial direction 17. The elastic sealing ring 8 lies in a groove 27 of the housing 3 which circulates in the separating surface 2. In the assembled state of the two housing parts 4, 5, the circumferential groove 27 is formed by a circumferential wall 28 and an end face 30 of the lower housing part 4, as well as by a further end face 29 of the upper housing part 5. As a result of an axial clamping of the two housing parts 4, 5 against each other, the elastic sealing ring 8 bears against the two end faces 29, 30 clamped clamped. In addition, the bearing 7 presses the sealing ring 8 against the circumferential wall 28 in the radial direction 17, as a result of which a sealing arrangement is also ensured in the radial direction 28. The combination of axial and radial pressing of the sealing ring 8 results in an effective sealing of the two housing parts 4, 5 within the separating surface 2 with respect to one another. It may also be expedient to provide a sealing pressing only in the radial direction 17 or the axial direction 18.

p0024The interior of the filter housing 3 is divided by the filter insert 1 into a radially outer, annular space for forming a raw side 22 as well as into a radially inner, approximately cylindrical space for forming a pure side 23. The housing part 4 has at least one schematically indicated opening 25, through which the medium to be filtered, in this case oil, flows into the raw side 22. From there, the medium to be filtered flows through the filter body 19 counter to the radial direction 17, the two axial end disks 10 preventing axial outflow. The medium, which is filtered after the passage through the filter body 19 and flows into the refining side 23, emerges from the filter housing 3 through a central opening 26 in the cleaned state.

p0025The seal 6 of the two housing parts 4, 5 comprising the bearing ring 7 and the sealing ring 8 is displaceable on the filter insert 1 in the manner described in more detail below in relation to the axial direction 18 and is retained captively on the filter insert 1. If a replacement of the filter insert 1 is required during maintenance work, the housing part 5 acting as a cover is separated from the housing part 4, after which the filter insert 1 can be removed from the housing 3 or from the housing part 4 remaining on the motor. As a result of the captive holding of the seal 6 on the filter insert 1, this is removed together with the filter insert 1 and disposed of. Reuse of the used seal 6 is avoided. A new, identical filter insert 1 can subsequently be inserted into the lower housing part 4, whereby at the same time the new seal 6, which is captively retained thereon, is displaced at least roughly into its intended installation position in the axial direction 18. The axial displaceability of the seal 6 opposite the filter insert 1 permits fine positioning of the seal 6 opposite the groove 27 independently of a movement of the filter insert 1. The captive holder on the filter insert 1 ensures that the seal 6 is not forgotten during the final assembly of the filter housing 3 or during the connection of the two housing parts 4, 5. In addition, the filter body 19, together with its two end disks 10, is mirror-symmetrical relative to a mid-plane 20 perpendicular to the axial direction. This makes it possible to introduce the filter-insert 1, which is of mirror-symmetrical overall design as a whole, with one of its two ends 12, 13 first into the housing part 5, in which case the seal 6 can be freely displaced in the axial direction 18 in its separating position.

p0026The seal 6 comprising the bearing ring 7 and the sealing ring 8 follows <figref idrefs="f0001">FIG</figref> Is a perspective view of FIG <figref idrefs="f0002">FIG</figref> shown. The supporting ring 7 is essentially flat and is made of a rigid plastic in comparison to the rubber-like elastic sealing ring 8. In conjunction with the planar embodiment, the supporting ring 7 is at least rigid in the radial direction 17 substantially to the extent that it acts in the radial direction 17,<figref idrefs="f0001">FIG</figref> Can apply to the sealing ring 8 against the peripheral wall 28. The bearing ring 7 has openings 16 which are distributed over the circumference and are designed as longitudinal holes and which have an axial throughflow of the untreated side 22 (<figref idrefs="f0001">FIG</figref>) In the filter housing 3.

p0027The rubber-elastic sealing ring 8 encloses a radially outer edge of the carrier ring 7 with an approximately U-shaped cross-section. This affords a form-fitting fastening of the sealing ring 8 to the bearing ring 7. In addition or as an alternative, the sealing ring 8 can also be adhesively bonded, injected, vulcanized or attached in a different manner.

p0028The circumferential bearing ring 7 is provided with at least one securing edge 9 on the inside with respect to the radial direction 17. The<figref idrefs="f0002">FIG</figref> On its two ends 12, 13 located in the axial direction 18, has at least one end stop 11 for the at least one securing edge 9 (<figref idrefs="f0002">FIG</figref>) on. As a result, the seal 6 can be displaced<figref idrefs="f0002">FIG</figref> Are displaced in the axial direction 18 on the filter body 19 but are not drawn off from the filter body 19.

p0029In the exemplary embodiment according to FIG <figref idrefs="f0002">FIG</figref> The supporting ring 7 has, in the opposite direction to the radial direction 17, inwardly projecting teeth 15 distributed uniformly over the circumference. A corresponding number of securing edges 9 are formed by the teeth 15. With simultaneous reference to the<figref idrefs="f0002">FIGS. 2 and 3</figref> The interaction of the teeth 15 acting as securing edges 9 with the corresponding end stops 11 becomes clear: the filter paper of the filter insert 1 is folded and cylindrically shaped to the filter body 19 in such a way that a number of folds 14 extend in the axial direction 18. In the assembled state of the seal 6, the teeth 15 engage between the axially extending folds 14, so that the teeth shown in FIG<figref idrefs="f0002">FIG</figref> Can be displaced from its exemplary intermediate position in the axial direction 18 into any axial positions indicated by dashed lines in FIG. 6 '. The two end disks 10, which are fastened to the axial ends 12, 13 on the filter body 19, have an outer diameter which essentially corresponds to the outer diameter of the folded filter body 19. In the recesses, which are formed by the folds and extend in the axial direction 18, the end disks 10 form end stops 11 for the teeth 15 acting as securing edges 9 between the folds 14. The seal 6 can not subsequently pass over the end disks 10 from the filter body 19. The folds 14 and the teeth 15 are each distributed uniformly over the circumference. The number of the folds 14 and the teeth 15 is such that a tooth 15 engages between each pair of folds 14 in the exemplary embodiment shown. A different number of folds 14 and teeth 15 can also be expedient, the number of folds 14 advantageously being an integer multiple of the number of teeth 15.

p0030Deviating from the rotationally symmetrical and in particular cylindrical shape of the filter insert 1 and the circular ring shape of the seal 6, <figref idrefs="f0002">FIG</figref> A different, for example elliptical or rectangular cross-sectional shape may also be expedient. Instead of the filter-shaped filter body 19 according to FIG<figref idrefs="f0002">FIG</figref> A smooth, for example wound filter body can also be expedient, in which case the end stops 11 protrude beyond the circumferential contour of the filter body 19 in the radial direction 17.

p0031Such an embodiment is illustrated by way of example in a schematic front view in FIG <figref idrefs="f0003">FIG</figref> shown. Both end disks 10 are designed identically and have uniformly distributed projections 31 distributed over their circumference, protruding in the radial direction 17 via the outer contour of the filter body 19 (not shown). The seal 6 is comparable to the exemplary embodiment according to FIG<figref idrefs="f0002">FIG</figref> With a bearing ring 7 having openings 16 and a sealing ring 8 extending radially outwards. Deviating from the exemplary embodiment<figref idrefs="f0002">FIG</figref> The supporting ring 7 has no radially inner teeth 15 (<figref idrefs="f0002">FIG</figref>), But is limited inwardly relative to the radial direction 17 by a circular peripheral edge 32. The projections 31 of the end disks 10 protruding in the radial direction 17 have a radially outer dimension which is greater than the inner diameter of the circular inner edge 32. In this case, the securing edge 9 of the carrier 7 is formed by the circular inner edge 32 which extends in the radial direction 17 of FIG The lugs 31 are overlapped.

p0032The inner edge 32 has a radial play against the outer contour of the filter body 19, so that the seal 6 is comparable to the illustration according to FIG <figref idrefs="f0002">FIG</figref> Is freely displaceable in the axial direction 18 indicated there. The end stops 11 designed as lugs 31 hold the seal 6 on the filter insert 1 in the axial direction 18 captively on the filter insert 1.

p0033In <figref idrefs="f0004">FIG. 4a</figref> Is an alternative of a seal carrier, shown in a section sketch. A filter insert 20 is provided with two end disks 26, The end disks have stop webs 33, 34, which limit the axial mobility of a sleeve. The sleeve 21 does not engage in folds of the zigzag-folded filter insert 20, but can be displaced on the folds. It is equipped with support webs 22, 23, to which a sealing ring 24, as shown in FIG<figref idrefs="f0004">FIG. 4b</figref> Is shown. The sealing ring has a shape suitable for the sealing of the housing parts 30, 31. On the housing part 31 there is a groove in which a stripping ring 32 is arranged, which has the task of preventing leakage of liquid from the housing upon opening or closing of the two housing parts. The wiper ring does not assume any sealing function and is therefore not subject to wear.

p0034The advantage of this structure is that only relatively short elastic webs 25 are required by the carrier webs 22, 23, so that a sealing guide is ensured.