Patent Application
20200222835
The invention relates to a filter element assembly having at least one sealing element for filtering fuel using water separation, in particular for use as an oil or fuel filter of an internal combustion engine of a motor vehicle, and a filter system with such a filter element assembly.
This section discusses background, as related to the present application. It is to be noted that not all the information presented here is prior art, but is provided for better understanding of the problem to be solved.
EP 2099544 B1 discloses an exchangeable filter insert in an oil filter. The oil filter comprises a filter housing that can be split along a separating surface and the corresponding exchangeable filter insert. Two housing parts of the filter housing are sealed against one another along the separating surface by means of a sealing element. The sealing element is captively attached to the filter insert.
The housing seal and the filter insert form a structural unit that is replaced as a whole within the prescribed maintenance intervals. With the removal of the old filter insert and the installation of the new filter insert, the assembly in one structural unit inevitably means that the seal is also replaced. This prevents the latter from being reused or forgotten during assembly.
The unit consisting of filter insert and sealing element must be adapted exactly to the contour of the filter housing due to the system. The installation of filter cartridges with a different design, which may not correspond to the operating regulations, is difficult or even impossible. Rather, it is ensured that, due to the geometric interplay of the filter housing with the sealing element, only the exactly fitting, correct filter insert can be installed. The confusion-free exchange of the filter insert is simplified and the operational safety of the motor vehicle or its internal combustion engine is increased.
It is therefore an object of the invention to provide a filter element arrangement for filtering fuel using water separation, which enables a tolerant yet permanent seal in a filter housing.
A further object of the invention is to create a filter system for filtering fuel using water separation, which enables a tolerant yet permanent seal between a raw area and a clean area of the filter system.
According to one aspect of the invention, the aforementioned objects are achieved by a filter element assembly, in particular for filtering fuel, preferably using water separation, which comprises at least one filter element with at least one end plate arranged of the filter bellows on the end side, on which a circumferential sealing element is arranged. When used as intended, the sealing element is provided in a filter system for sealing the clean side against the raw side of the filter element and under compression between a first housing part and a second housing part of the filter system for sealing a housing interior of the filter system against an environment of the filter system.
Favorable embodiments and advantages of the invention are disclosed in the further claims, the description and the drawings.
A filter element arrangement is proposed, in particular for filtering fuel, preferably using water separation, comprising a filter element having at least one annular filter bellows which is flowed through in the radial direction, and at least one end plate arranged on the filter bellows on the end side, as well as at least one sealing element arranged on the end plate. When used as intended, the sealing element is provided in a filter system for sealing the clean side against the raw side of the filter element and under compression between a first housing part of the filter system and a second housing part of the filter system for sealing a housing interior of the filter system against an environment of the filter system. The filter element assembly according to the invention has a sealing element on the filter element, which makes it possible to seal plastic housings with radial tolerances and dimensional changes more reliably over the service life than with conventional O-rings, without having to provide complex positioning arrangements or tests when installing the filter element with the sealing device. The reliable sealing effect is achieved in that the sealing element can be designed, for example, in the form of a molded seal which can be arranged on a radial outside of the end plate and can be supported radially inwards from the radially outer contact side of the end plate. When the filter element is inserted into a filter housing, this molded seal seals against the filter housing, so that the raw side is separated from the clean side of the filter element. Furthermore, the molded seal is able to seal both housing parts of the filter housing by pressing the sealing element against one another and against the environment, so that a housing interior of the filter system is sealed against an environment of the filter system. This is achieved in that different sealing surfaces of the molded seal abut sealingly against corresponding sealing surfaces of the housing parts. The molded seal can be pressed axially and radially in order to reliably exert its sealing effect.
The sealing element in the form of a molded seal can be fitted directly onto the contact side of the end plate of the filter element or can be firmly connected to it. The end plate forms the seal carrier. In this way it can be ensured that the sealing element maintains its desired position when the filter element is installed in the filter housing and does not twist or slip. This also allows a certain tolerance compensation for tolerances in the manufacture of the filter housing and in the manufacture of the filter element. According to an advantageous embodiment of the filter element arrangement, the sealing element can be arranged on the intended lower end plate. This can advantageously be used to seal a clean side water separation, in which water is collected in a water collecting space at the intended lower end of the filter element.
According to an advantageous embodiment, the intended lower end plate on which the sealing element is arranged can have a water discharge opening for separated water. This allows a compact arrangement and can advantageously be used to seal a water separation on the clean side, in which water is collected in a water collecting space at the intended lower end of the filter element.
According to an advantageous embodiment, a further sealing element for sealing between the clean side and the raw side of the filter element can be provided in the region of the end face of the filter bellows, which is opposite the intended lower end plate. This enables a compact design and improved sealing properties of the filter element assembly. The end face of the filter bellows opposite the intended lower end plate can, for example, have an end plate on which the further sealing element can be arranged. The further sealing element can be, for example, a round cord ring. The further sealing element can be arranged radially within a clear width of the filter bellows. The further sealing element can be aligned with the end face of the filter bellows or be slightly offset, in particular positioned slightly above the end face of the filter bellows. Conveniently, the additional sealing element allows the filter element to be pushed onto a connector which is fixed to the housing and which engages in the interior of the filter bellows when it is inserted into the housing.
According to an advantageous embodiment, the sealing element can be provided on the intended lower end plate for sealing the raw side against a clean-side water collecting space. When replacing the filter element, contamination of the clean side can optionally be reduced or avoided.
According to an advantageous embodiment, the intended lower end disk can have a contact surface for axial contact with one of the housing parts, which can be offset radially inwards opposite an elastic sealing material of the sealing element. The contact surface for axial contact can be provided, in particular, on the outer end face of the intended lower end plate. With a differential pressure between the raw side and the clean side, an axial movement of the filter element can advantageously be limited. The sealing element can either be releasably attached or captively attached to the end plate.
According to an advantageous embodiment, the sealing element can be captively connected to the intended lower end plate. Fewer components are required. The installation of the filter element is simplified. The sealing element can advantageously be glued to the end plate or vulcanized onto the end plate. Alternatively, the sealing element can be detachably fastened, for example only be pulled on.
According to an advantageous embodiment, the sealing element can be a sealing element which, with at least one radially inner surface, lies sealingly against a radially outer contact side of the end plate. This ensures that the sealing element seals against the end plate and is reliably sealed when installed in a filter housing between the raw side and the clean side of the filter element. In particular, the sealing element can be designed as a sealing element without a seal carrier, the sealing element being arranged directly on the abutment side of the end plate and being, for example, firmly connected to the end plate, for example glued or vulcanized to it. Optionally, the sealing element can also simply be pulled onto the end plate.
The sealing element can have tabs which enable the sealing element to be changed easily. Furthermore, the sealing element can be connected via coupling elements to one of the two housing parts, preferably the cover or the housing part located at the top during upright assembly, which is advantageous in a service-friendly maintenance process, since the sealing element can remain in the unscrewed cover of the filter housing. The coupling elements can have snap-in or latching elements which also acoustically signal correct assembly.
According to an advantageous embodiment, the sealing element can have at least two sealing surfaces, one of which is provided in the installed state in a filter system for contacting each of the two housing parts. By designing the sealing element with at least two sealing surfaces, the tolerance situation can be checked more easily, since the sealing to each individual housing part can take place independently of the sealing to the respective other housing part. The sealing material has the necessary deformability.
According to an advantageous embodiment, the two sealing surfaces can extend at least in sections inclined to a longitudinal axis of the filter element. The two sealing surfaces can run at an angle to each other and to the longitudinal axis of the filter element, since the sealing element can be pressed both axially and radially when the filter element is inserted in the filter housing and the two housing parts are closed, which results in a reliable and tolerance-compensating seal of the filter element and the filter system.
According to an advantageous embodiment, an expansion of the sealing element in the uncompressed state in the axial direction can be greater than an expansion of the sealing element in the radial direction. Since an axial pressure component on the sealing element is greater than a radial pressure component when the filter element is inserted and then closed, it is advantageous if the sealing element has a greater extent in the axial direction and can thus accommodate a greater change in length.
According to an advantageous embodiment, the inner surface of the sealing element can be firmly connected to the contact side of the end plate, the sealing element in particular being vulcanized onto the contact side. It is expedient if the sealing element is arranged directly on the outside of the end plate, since a reliable and permanent seal between the sealing element and the end plate can be achieved in this way. The sealing element also does not change its position when the filter element is installed in a filter housing, which also has a favorable effect on the sealing effect on the filter housing. In addition, for example, vulcanizing the sealing element onto the end plate represents a very inexpensive and process-favorable possibility of firmly connecting the sealing element to the end plate, which simplifies the manufacture of the filter element.
According to an advantageous embodiment, the sealing element on the inner surface can have at least one holding contour for fixing the sealing element on the contact side, which holding contour engages in a corresponding counter-contour on the contact side. The sealing element can be axially secured against displacement of the sealing element during installation in the filter housing with the aid of the holding contour. By engaging the holding contour in a corresponding counter-contour in the outside of the end plate, a secure connection between the sealing element and the end plate can be created. Optionally, the connection for replacing the sealing element can be released again in the event of service, which is not, however, absolutely necessary.
According to an advantageous embodiment, the at least one holding contour of the sealing element can have one or more latching elements which engage in corresponding recesses on the contact side of the end plate. Locking the sealing element with the end plate establishes a secure connection between the two components. In addition, a haptic reaction for secure mounting of the sealing element on the end plate can also be realized via the latching, which contributes to a reliable attachment of the sealing element to the end plate.
According to a further aspect, the invention relates to a filter system for filtering a fluid, in particular for filtering fuel, preferably with a water separating unit, comprising a filter element arrangement with an exchangeable filter element, which comprises at least one annular filter bellows which can be flowed through in particular and at least one end disk arranged on the end face of the filter bellows, as well as with a circumferential sealing element arranged on the end plate. The filter system further comprises a filter housing, comprising a first housing part and a second housing part, the filter element being arranged in at least one of the housing parts. In this case, a sealing element is arranged on a radially outer contact side of an intended lower end plate and is supported radially inward from the contact side. The sealing element is provided for sealing the clean side against the raw side of the filter element and is provided under compression between the first housing part and the second housing part for sealing a housing interior of the filter system against an environment of the filter system.
According to an advantageous embodiment, the sealing element can be pressed axially and radially in the installed state with the filter housing closed. The sealing element is initially axially pressed by the axial approach of the two housing parts, while at the same time sealing surfaces of the sealing element arranged obliquely to the longitudinal axis are pressed radially inwards and thus bring about a radial pressing of the sealing element, since the sealing element can abut evenly against an inner surface on its counter surface, a contact side of the end plate, and is supported radially outwards from the contact side. This gives one a self-reinforcing sealing system that does not require any further mechanical pressing. The sealing element does not serve as a stop when the filter housing is closed. Rather, a mechanical stop is expediently provided on the filter housing, which is closed, for example, by means of a screw thread, so that the screw connection can only take place until the two housing parts abut against the stop. The sealing element can only be pressed to a certain degree in a precisely defined manner so that a reliable and permanent sealing function is guaranteed. The sealing element is thus in a state of equilibrium.
The sealing element is also centered during assembly in the first housing part and when the filter housing is closed by the second housing part itself. Especially when used as an oil filter of an internal combustion engine in a motor vehicle, in which the interior of the housing is pressurized and where the sealing element is should reliably work at temperatures from −40° C. to 150° C. with pressures of up to 4.5 bar and peaks of up to 25 bar, such a self-centering sealing system should be of great advantage, since even with mechanical pumping of the filter housing due to changing pressure conditions, the sealing function is maintained and guaranteed.
An interface between the first housing part and the second housing part of the filter housing is sealed off from the environment via the sealing element, the interface with the sealing element not having to coincide with an interface, for example for screwing or clipping. The two interfaces can also be spatially separated axially, which can even be a significant advantage for the stability of the sealing of the filter housing. The functions of mechanically closing the filter housing and sealing are thus separated from one another.
The sealing element can be a sealing element without a seal carrier, the sealing element abutting with its inner surface directly against the contact side of the end plate. According to an advantageous embodiment, the sealing element can be chambered between the first housing part, the second housing part and the intended lower end plate. The chambering is expediently brought about by a sealing surface abutting against a component sealing surface of the first housing part, a sealing surface abutting against a component sealing surface of the second housing part and an inner surface of the seal bearing against the abutment side of the end plate, wherein the sealing element can be arranged in the installed state in a sealing groove formed from the component sealing surface and an inner wall.
According to an advantageous embodiment, the sealing element can protrude in the axial direction from a sealing groove of the first and/or second housing part. In particular, the sealing element can protrude from a sealing groove of the first and/or second housing part in the compressed state. In this way, the inner wall of the sealing groove covers an axial extent of the sealing element at most by only half, preferably at most by one third. Furthermore, the groove depth of the sealing groove extends only partially over a component sealing surface on the same housing part. Particularly when the sealing element is in the sealing, that is to say compressed state, the sealing element protrudes from a sealing groove in the axial direction. The sealing element advantageously protrudes at least 50%, in particular 70%, and very particularly advantageously 80% of its axial extent in the compressed state from the sealing groove. In this way, a reliable and permanent sealing function of the sealing element is guaranteed. Typically, about a quarter of the axial extent of the sealing element should be available for pressing the sealing element.
According to an advantageous embodiment, the sealing element can have a base part and at least one axial protrusion, the base part abutting on the radially inner surface on the radially outer contact side of the end plate and at least in the compressed state being supported radially inwards from the contact side. In the compressed state, the inner surface can advantageously have an axial extent of at least 50% of the axial extent of the sealing element. In this way, the two functions of supporting the sealing element in the radial direction and performing the actual sealing function in separate components are realized. All radial forces on the sealing element can thus be absorbed via the end plate.
According to an advantageous embodiment, the at least one axial protrusion can be provided for bearing against a component sealing surface of the first housing part or against a component sealing surface of the second housing part. The axial protrusion can thus be designed to perform a sealing function together with the component sealing surface. The radial support function of the sealing element can be implemented separately.
According to an advantageous embodiment, a component sealing surface of one housing part can be arranged in the axial direction outside the sealing groove of the other housing component, which allows greater freedom of design in the attachment of the sealing groove in one of the two housing parts.
According to an advantageous embodiment, the sealing element can have at least two sealing surfaces, one of which is provided in the installed state in the filter system for contacting each of the two housing parts. By designing the sealing element with at least two sealing surfaces, the tolerance situation can be checked more easily, since the sealing to each individual housing part can take place independently of the sealing to the respective other housing part. The sealing material has the necessary deformability.
According to an advantageous embodiment, a further sealing element for sealing between the clean side and the raw side of the filter element can be provided in the region of the end face of the filter bellows, which is opposite the intended lower end plate. In particular, the further sealing element can be provided in the region of the end face of the filter bellows, which is opposite the intended lower end plate. When inserted into the housing, the filter system can be pushed onto a connection piece fixed to the housing, against which the filter element can be sealed with the further sealing element. The further sealing element can advantageously be a round cord ring.
The invention preferably relates to the use of the filter system as an oil or fuel filter. With these fluid filters, it is usually necessary to replace the filter element after a predetermined mileage, so that the filter system is opened at regular intervals and the filter element removed, and a new filter element has to be inserted. With the sealing element according to the invention, it is advantageously possible to replace the sealing element reliably and in a maintenance-friendly manner. Permanent sealing of the filter system after changing the filter element is thus advantageously possible. Since the filter element and sealing element are expediently stored in a service unit and made available for maintenance, it is also ensured that the correct sealing element is used when changing the filter element.
Further advantages arise from the following drawing description. Embodiments of the invention are illustrated in the drawings. The drawings, the description and the claims contain numerous features in combination. A person skilled in the art will also expediently consider the features on an individual basis and combine them into other appropriate combinations.
The drawing show by way of example:
The same or similar components in the figures are referenced with same reference characters. The figures merely illustrate examples and shall not be construed as limiting.
The filter system 100 for filtering a fluid comprises a filter housing 108 with a first housing part 109 and a second housing part 110, in which a filter element assembly with a filter element 10 is arranged, which has an intended lower end plate 16 and on the end face opposite the intended lower end plate 16 of the filter element 10, a further end plate, which is open in the interior and through which an unspecified, clean-side connector engages in the interior of the filter element 10.
The two housing parts 109, 110 are connected to one another via a screw thread 114, the second housing part 110 being screwed onto the first housing part 109 up to a stop 116. The filter element 10, which is provided for filtering fuel using water separation, has a filter bellows 12 which is closed with the intended lower end plate 16. The radially flowable filter bellows 12 is designed as a hollow cylinder, wherein a fluid flow runs from the raw side 72 in the housing interior 120 through the outside of the filter bellows 12 radially inward to the clean side 70 and can be removed through the nozzle from the filter element 10 axially in the direction of filtering the fluid a longitudinal axis L of the filter element 10. A coalescer element 130 is arranged on the radial inside of the filter bellows 12 and is provided for water separation from the fuel. The separated water is collected in the water collecting space 132 of the first housing part 109 and can be drained out of it if necessary. For this purpose, the intended lower end plate 16 has an unspecified water discharge opening for separated water.
A sealing element 30 in the form of a molded seal 32 is arranged on a radial outer circumference of the intended lower end plate 16, the sealing element 30 having a radially inner surface 18 being arranged on a radially outer contact side 34 of the end plate 16 and being supported radially inward from the contact side 34. The sealing element 30 is provided for sealing the clean side 70 against the raw side 72 of the filter element 10 and the first housing part 109 and the second housing part 110 of the filter system 100 against the external environment 122. For this purpose, the sealing element 30 is chambered between the first housing part 109, the second housing part 110 and the end plate 16.
In the area of the end face of the filter bellows 12, which is opposite the intended lower end disk 16, a further sealing element 90 is provided for sealing between the clean side 70 and the raw side 72 of the filter element 10. This can be designed as a round cord ring and seals between the filter element 10 and the unspecified clean-side connector.
Furthermore, it can be seen that the intended lower end plate 16 has a contact surface 17 for axial contact with a contact surface 63 of one of the housing parts 109, which is offset radially inwards relative to the elastic sealing material of the sealing element 30. The contact surface 17 is provided on the outer end face of the intended lower end plate 16.
Through the contact surface 17, the end face of the intended lower end plate 16 comes into contact with the contact surface 63 of the housing part 109 and can thus limit an axial movement of the filter element 10 (
| Number | Date | Country | Kind |
|---|---|---|---|
| 10 2016 009 844.9 | Aug 2016 | DE | national |
| Number | Date | Country | |
|---|---|---|---|
| Parent | PCT/EP2017/067958 | Jul 2017 | US |
| Child | 16832375 | US |
