Filter device

A filter may include a filter housing having a filter housing crucible and a filter housing cover. A ring filter element may be arranged in the filter housing and have an axially projecting pin on a lower end disc. The pin may be configured to be received by a channel on the filter housing crucible side when the filter device is assembled. A tube-shaped dome may be arranged on the filter housing crucible and engage an inner chamber of the ring filter element and a guide contour may be arranged on a free end of the tube-shaped dome and interact with a guide element arranged on the ring filter element.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to German Patent Applications 10 2009 049 868.0 filed on Oct. 20, 2009 and PCT/EP2010/062684 filed on Aug. 31, 2010, which are hereby incorporated by reference in their entireties.

TECHNICAL FIELD

The present invention relates to a filter device, in particular an oil or fuel filter, comprising a filter housing having a filter housing crucible and a filter housing cover.

BACKGROUND

In generic filter devices, in order to ensure that an authorised ring filter element is used, a pin projecting axially from a lower end disc is often arranged thereon, by means of which pin the ring filter element engages in a channel on the filter housing crucible side when the filter device is assembled, and the filter device can then only be put into use if the used ring filter element has the necessary pin in the right place. As a result of this, the use of unauthorised ring filter elements and consequently damage to an internal combustion engine, for example, can in particular be prevented. With such filter devices, however, the assembly thereof, in particular the mounting of the ring filter element in the filter housing has proven difficult.

SUMMARY

The present invention concerns itself with the problem of specifying for a filter device of the generic type an improved or at least a different embodiment, which has a simple design and makes assembly of the filter device easier.

This problem is solved according to the invention by the subject matter of the independent Claims. Advantageous embodiments form the subject matter of the dependent claims.

The present invention is based on the general concept of providing, in a filter device known per se comprising a filter housing having a filter housing crucible and a filter housing cover, a tube-shaped dome on the filter housing crucible, which dome is used as a guide for a ring filter element to be inserted into the filter housing crucible. The ring filter element to be used has an axially projecting pin on a lower end disc, by means of which pin it engages at least partially in a channel on the filter housing crucible side and seals the channel in a leakproof manner when the filter device is assembled. The tube-shaped dome provided according to the invention on the filter housing crucible engages in an inner chamber of the ring filter element when the filter device is assembled. The said tube-shaped dome according to the invention has at its free end a guide contour, which interacts with a guide element arranged on the ring filter element in such a manner that the latter is guided along the guide contour during assembly and thereby makes it possible for the pin to be inserted in a simple and precise manner into the channel on the filter housing crucible side. The provision of the guide contour on the tube-shaped dome of the filter housing crucible not only provides an extremely simple way of guiding the ring filter element, but in particular other guide contours of often complex design can be omitted thereby. Despite the relatively simple design of the embodiment of the guide contour, it guides the ring filter element during assembly in an exact and targeted manner, it being possible as the pin on the ring filter element side slides along the guide contour for the pin to be guided reliably in the direction of the channel on the filter housing crucible side and also introduced into the channel. The assembly of the filter device can thus also be greatly simplified with the tube-shaped dome provided according to the invention with its guide contour.

In an advantageous development of the solution according to the invention, the guide contour on the dome side has an axial groove, towards which the guide element is guided when the filter device is assembled, and which is arranged relative to the pin on the ring filter element side in such a manner that the latter is introduced into the channel on the filter housing crucible side if the guide element enters the axial groove. This exact alignment of the pin relative to the guide element and the interaction of the guide element with the guide contour on the dome side mean that only authorised ring filter elements can be inserted into the filter device and not other ring filter elements which for example do not have a pin. In the latter case, the channel on the filter housing crucible side is not sealed and allows a bypass flow which circumvents the ring filter element and greatly reduces the filtering effect of the filter device. If ring filter elements with a pin are used, both the guide element and a distance between this and the pin must correspond to precisely predefined dimensions, so that when the guide element interacts with the guide contour on the dome side, the pin also enters the channel on the filter housing crucible side if the guide element is pushed into the axial groove of the guide contour. Thus the use of unauthorised ring filter elements is generally at least greatly made more difficult, as a result of which damage to an internal combustion engine connected to the filter device can be reduced or completely ruled out.

In an advantageous development of the solution according to the invention, the guide contour on the dome is formed like a circular ramp, the axial groove being arranged between the highest and the lowest point of the ramp. When the ring filter element is placed on, it therefore slides with its guide element along the circular ramp until it reaches the axial groove and can be pushed, or slides, into the latter. This insertion or sliding process can be produced for example by screwing the filter housing cover onto the filter housing crucible. Alternatively, it is also conceivable for the guide contour on the dome to be formed like an inclined hollow needle, the axial groove being arranged at the lowest point. In this case, the guide element can be guided particularly smoothly towards the axial groove and thus the pin can be guided particularly smoothly towards the channel on the filter housing side. In contrast to filter devices known from the prior art, in which the pin on the ring filter element side was often used as a sliding element, the pin according to the invention no longer has to have such a sliding property and can therefore be formed for example from an elastic material, in particular from rubber. The tube-shaped dome on the filter housing crucible can for example form part of a clean channel.

Further important features and advantages of the invention can be found in the subclaims, the drawings and the associated description of the figures using the drawings.

It is self-evident that the features which are mentioned above and those which are still to be explained below can be used not only in the combination specified in each case, but also in other combinations or alone without departing from the scope of the present invention.

Preferred exemplary embodiments of the invention are shown in the drawings and are explained in more detail in the following description, with the same reference symbols referring to the same or similar or functionally identical components.

DETAILED DESCRIPTION

According toFIG. 1, a filter device1according to the invention, for example an oil or fuel filter, or an air filter for a motor vehicle, has a filter housing4formed from a filter housing crucible2and a filter housing cover3which can be screwed to the latter. Arranged inside the filter housing4is a ring filter element5, which is known per se and is for example supported by means of a support-structure-like inner shroud7with respect to an inner chamber6. The ring filter element5is delimited in the axial direction in a likewise known manner by an upper end disc8and a lower end disc9. A pin10which projects from the lower end disc9in the axial direction is provided (cf. for exampleFIGS. 6a, band7), which preferably engages in a leakproof manner in a channel11on the filter housing crucible side and thereby seals it when the filter device1is completely assembled. To this end, a sealing element formed in a known manner, for example an O-ring seal12, can be provided on the pin10. The channel11is in most cases a no-load channel.

Furthermore, a tube-shaped dome13(cf.FIGS. 2 and 3) is provided on the filter housing crucible2, which dome engages in the inner chamber6of the ring filter element5and for example forms part of a clean channel when the filter device1is assembled. According to the invention, a guide contour14is provided on a free end of the said tube-shaped dome13, which guide contour interacts with a guide element15(cf. for exampleFIGS. 4 and 5) arranged on the ring filter element5. This guide contour14can for example be formed like a circular ramp, as shown inFIG. 3, or else like an inclined hollow needle, as shown for example inFIG. 2. A common feature of both guide contours14is that they have an axial groove16, towards which the guide element15is guided during assembly of the filter device1, and which is aligned relative to the pin10in such a manner that the latter can be introduced into the channel11on the filter housing crucible side if the guide element15enters or is pushed into the axial groove16.

Assembly of the filter device1is shown in different method steps inFIGS. 4ato4d. First, in assembly step4a, the ring filter element5is inserted into the filter housing crucible2until it rests with the guide element15on the guide contour14on the dome side. The ring filter element5is then rotated, for example by screwing on the filter housing cover3, so that the guide element15, as shown inFIG. 4b, slides along the guide contour14as far as the axial groove16, which is preferably arranged between the highest and the lowest point of the ramp-like guide contour14. After it has reached the axial groove16, the pin10is aligned coaxially flush with the channel11, so that the ring filter element5can be pushed in the axial direction with the guide element15into the axial groove16and at the same time with the pin10into the channel11. This state is shown for example inFIG. 4d.

An installation process of the ring filter element5functions in the same manner if the guide contour14is configured like a hollow needle, as shown inFIGS. 5ato5d. With such a guide contour14, the axial groove16preferably lies at the lowest point of the guide contour14. It is not important whether the guide element15is arranged on the inner shroud7, as shown for example inFIGS. 4ato4d, or on the lower end disc9, as shown inFIGS. 5ato5d. In both cases the guide element15is formed as a guide pin pointing radially inwards.

It can be seen inFIGS. 4ato4dthat the lower end disc9is sealed off from the dome13by means of a sealing lip17, which bears against an outer face of the tube-shaped dome13in a leakproof manner when the ring filter element5is installed. The said sealing lip17is flexible and preferably formed in one piece with the lower end disc9. It is not important for the sealing function whether the sealing lip17faces upwards, as shown for example inFIG. 9a, b, or downwards, as shown for example inFIG. 10a, b, when the ring filter element5is installed. Alternatively, it is also conceivable for a separate sealing ring18to be provided on the lower end disc9, which seal bears against the outer face of the tube-shaped dome13in a leakproof manner when the ring filter element5is installed. Such a sealing ring18is shown for example inFIGS. 5,7,11,14a,15aand16c.

A particular advantage of the filter device1according to the invention is that the pin10, rather than sliding along the ramp and thereby being configured as a sliding element as in the prior art, can be elastic, for example formed from rubber, as the pin10no longer has to have any sliding properties.

It can be seen inFIGS. 6aand9bthat, in contrast toFIGS. 7 and 8, the pin10can simply be tube-shaped and bears an O-ring seal12on a head. However, the pin10can of course also have a cross-like cross-sectional structure, as can be seen for example inFIGS. 7 and 8, as a result of which the pin10is more rigid overall. The ring filter element5can generally be formed as a folded star with a paper or flowable filter material.

FIGS. 9aand9bshows a ring filter element5and the lower end disc thereof in detail, which likewise has a simply tube-shaped pin10, on the free end of which an O-ring seal12is arranged. In contrast toFIGS. 10aand10b, the lower end disc9of the ring filter element5inFIGS. 9aand9bhas an upwardly facing sealing lip17. It is generally conceivable for the entire lower end disc9to be produced, in particular injection moulded, from a single material, for example from plastic or rubber, so that the sealing lip17is simply moulded onto the lower end disc9.

FIGS. 11aand11bshow different seals18,19, the seal in11abeing configured for example simply as a sealing coating19on a radially inwardly facing ring web20in a similar manner to that ofFIG. 15b. In contrast, the sealing ring18as shown inFIGS. 11b,14aand15ais formed as a separate component, for example from silicone or a fleece material.

FIG. 12ashows an exploded diagram andFIG. 12bshows an assembly position of the inner shroud7with the associated lower end disc9, it being possible for the latter to have an upwardly facing sealing lip17in the case ofFIG. 13aand a downwardly facing sealing lip17in the case ofFIG. 13b. The guide element15is arranged on the inner shroud7, which also has a further guide element15′, which interacts with a guide contour14′ arranged on the lower end disc9. However, the guide element15ofFIGS. 14a, band15a, bis arranged on the lower end disc9. In contrast toFIG. 13a, b, the lower end disc9ofFIG. 15a, bhas no sealing lip17but a sealing ring18(cf.FIG. 15a) or a sealing coating19(cf.FIG. 15b).

FIG. 16a, bandcshow the individual sealing variants again, soFIG. 16ashows an upwardly facing sealing lip17which bears against the dome13, while the lower end disc9ofFIG. 16bhas a downwardly facing sealing lip17.FIG. 16cshows a further variant of the guide contour14, an additional sealing ring18being arranged on the lower end disc9in this case.FIGS. 17aand17balso show how the sealing lip17in the embodiment ofFIG. 16abears against the outer lateral surface of the dome13, if the ring filter element5has reached its final rotary position and can be pushed axially downwards into this position. One condition for this axial displacement of the ring filter element5over the dome13is that the guide element15on the ring filter element side is in the axial groove16, which means at the same time that the pin10can be arranged coaxially flush with the channel11on the filter housing crucible side and introduced into the channel. This is shown for example inFIGS. 17aand17b.

FIG. 18andFIG. 19ato19cshows a further filter device1, with a check valve21and a bypass valve22. In this case too the dome13, which is likewise arranged centrally, has a guide contour14at its free end, which interacts with a guide element15on the filter element side (not shown). Here too a pin10(not shown) is arranged on the ring filter element5or on the lower end disc9thereof, which pin engages in a channel11on the filter housing crucible side and seals the channel in a leakproof manner when the filter device1is completely assembled.

Decisive advantages relating to the operation and assembly of the filter device can be achieved with the filter device according to the invention: Firstly, the use of unauthorised ring filter elements, which would for example result in damage to an internal combustion engine, can be reliably prevented, as these would have to have the guide element15on the ring filter element side and the guide contour14on the dome side, and the pin10aligned exactly with the guide element15, in order to able to be installed correctly in the filer device1. If for example a ring filter element without a pin10is used, the channel11, in particular the no-load channel, is not sealed in a leakproof manner, and a bypass flow which circumvents the ring filter element is produced. At the same time, the assembly and in particular the replacement of the ring filter element5according to the invention can be considerably simplified, as a restricted guidance device is produced by means of the guide element15and the guide contour14, which, when the filter housing cover3is screwed on, forces the ring filter element5to be positioned in such a manner that the pin10is aligned flush with the channel11and thus can be introduced without problems into the latter. It is of further advantage that in the present filter device1, the pin10no longer has to have sliding properties and for this reason can be formed for example much more flexibly, in particular from rubber.