FILTER ELEMENT WITH REMOVAL ELEMENT

Description

State of the art

[0001] The present invention relates to a filter element which can be used in particular in a liquid filter, such as a fuel filter or urea filter.

[0002] Liquid filters, particularly urea filters, are known from the prior art. These comprise a filter body, which is usually made of an unstable material, such as paper. The filter body is usually hollow-cylindrical in shape and is provided with end caps. If the filter is used, for example, in a vehicle, it is located within a housing, with the end caps sealing the filter to the housing, allowing a liquid to enter the interior of the filter, then be filtered through the filter body, and exit the housing again via a peripheral surface.

[0003] If the filter is to be removed from the housing, there is a risk that the filter body will be damaged and tear off, leaving only a portion of the filter to be removed. The remaining portion in the housing must then be removed, which requires considerable effort. This problem is exacerbated by the fact that the filter comes into contact with liquids during use, causing the filter to swell and create adhesion and friction between the filter and the housing wall.

[0004] A replaceable filter element and a cover arrangement are known from EP 1 008 375 A1.

[0005] A liquid filter with a filter insert is known from US 2014 / 0284265 A1.

[0006] From US 2010 / 0176046 A1 a filtration system with a filter basket and / or a filter element is known.

[0007] EP 2 764 901 A1 discloses a spin-on filter element for screwing into a liquid filter. The filter element has an opening in an end cap with a thread for screwing onto a connection of the liquid filter provided with a complementary thread. To ensure that the correct filter element is installed in the liquid filter, at least one coding projection is arranged upstream of the complementary thread of the connection of the liquid filter. Accordingly, the thread of the filter element has at least one slot that allows the filter element to be pushed over the at least one coding projection in a key-lock manner before being screwed onto or unscrewed from the complementary thread. Disclosure of the invention

[0008] A filter element with the features of claim 1 according to the present invention comprises a hollow, in particular hollow-cylindrical, filter body. The following directional information, in particular the radial, axial, and circumferential directions, refer to the hollow filter body. The filter body is preferably made from a cellulose layer impregnated with an epoxy resin and combined with a meltblown material, in particular made of polymers. Furthermore, the filter element comprises at least one, in particular annular, end cap. The end cap is arranged at one axial end of the filter element, advantageously fastened to the filter element. Particularly preferably, the filter element has two end caps, each fastened to an axial end of the filter body.According to the invention, the filter element has an additional second end cap, which is arranged axially at an end of the filter body opposite the end cap. Both end caps are advantageously made of plastic, for example polypropylene. Advantageously, only one of the end caps has the features described below. The end cap has a feed-through region with a first inner diameter and an engagement region with a second inner diameter. Both the passage region and the engagement region are advantageously arranged on the end cap. Thus, the end cap has the first inner diameter at the feed-through region, while the end cap has the second inner diameter at the engagement region. It is provided that the first inner diameter is larger than the second inner diameter.Furthermore, it is provided that a tool can be passed from the end opposite the end cap through the entire filter element and through the feedthrough area and can be brought into engagement with the end cap at the engagement area.

[0009] The filter element according to the invention thus has the advantage that a tool can be passed through the entire filter element, in particular to grip the end cap that is arranged furthest inside a housing. Thus, when the filter element is removed from a housing, force is transmitted not via the filter body, but from the tool via the end cap arranged furthest inside the housing with respect to a direction of insertion of the filter element into a filter housing to the filter body. Destruction of the filter body is thus ruled out, and any static friction between the filter and a housing can be overcome. This preferably also applies when the filter element does not have an inner support tube that connects the two end caps to one another. In other words, when the end caps are only connected to one another by the filter body itself.Such filters without a support element are particularly cost-effective to manufacture. However, in such a case, the filter body must, in a conventional arrangement, withstand the tensile forces alone when pulled out at the end cap closest to the pull-out opening of the filter housing. This can lead to internal tearing, especially if the filter body is moist or saturated with liquid. According to the invention, however, the filter body is only subjected to compressive forces when pulled out using the tool. Should it be damaged during removal, the damaged parts of the filter body are removed during the extraction process by the end cap furthest from the pull-out opening, which is pulled by the tool.

[0010] The subclaims show preferred developments of the invention.

[0011] The hollow filter body is preferably a circular cylinder. The filter body has an outer filter body diameter on its outside and an inner filter body diameter. The inner filter body diameter corresponds to the diameter of the hollow inner cylinder of the filter body. Preferably, the hollow inner cylinder is particularly circular-cylindrical. The first inner diameter of the end cap preferably corresponds to the diameter of the circular cylinder, in particular the hollow inner circular-cylindrical cylinder of the filter body. The feedthrough region thus has the same diameter as the filter body. The second inner diameter is preferably also a circular diameter, in particular concentric to the first circular diameter. Thus, a key-lock arrangement between the end cap and the tool can be easily realized.The circular cylinder can, in particular, have a surface structure, such as, particularly preferably, a waveform extending in the radial direction. Such a waveform can arise in the cross-section through the star-shaped pleated filter material of the filter body.

[0012] The engagement region preferably has a trough shape. Thus, it is preferably provided that a tool can be positively connected to the engagement region by inserting the tool into the trough. In this way, the engagement region allows not only the transmission of axial forces from the tool to the filter element, but also the transmission of rotational forces. This makes it possible, in particular, to rotate the filter element upon removal from a housing, whereby adhesions of the filter body to the housing can be released and static friction can be better overcome.

[0013] Furthermore, it is advantageously provided that the passage area is arranged circumferentially adjacent to the engagement area. This allows a tool to be passed through the filter element, whereby this occurs within the engagement area or the passage area. After the tool has been passed through the filter element, the tool can be rotated to rest against the engagement area.

[0014] The end cap is preferably designed symmetrically. In particular, it is provided that the end cap has at least two passage areas and at least two engagement areas. The symmetry of the end cap is, in particular, a point symmetry around the central axis of the hollow cylindrical filter body. The end cap is therefore designed to be particularly rotationally symmetrical.

[0015] The engagement region preferably comprises a projection. The projection is directed in particular radially inwards and thus in the direction of the central axis. The second inner diameter is provided on the projection. Particularly advantageously, the end cap has a tool receiving region at which the end cap has the first inner diameter. It is provided that the feed-through region corresponds to a partial region of the tool receiving region. The projection is arranged on the tool receiving region and thus stands out from the feed-through region. The feed-through region and engagement region are advantageously arranged directly adjacent. A tool can thus be guided very easily through the feed-through region and then reached the engagement region by rotation.

[0016] According to the invention, the filter element further comprises a damping element, wherein the damping element is attached to a fastening area of ​​the end cap. The attachment is particularly positive. Particularly advantageously, the damping element has at least one locking element, so that the damping element can be locked onto the end cap. This provides a simple, particularly detachable, yet stable connection between the end cap and the damping element. The damping element is made of an elastic material, preferably rubber.

[0017] Advantageously, the end cap also has a ramp area. The ramp area preferably runs axially away from the filter body, wherein the ramp area simultaneously runs in the circumferential direction from the engagement area to the feed-through area. If multiple engagement areas and feed-through areas are present, the ramp area runs from an engagement area to a feed-through area, wherein the engagement area and the feed-through area, between which the ramp area extends, are not arranged directly adjacent. The ramp area makes it easier to insert the tool, as it can be inserted into the filter element at any desired point. A force in the axial direction guides the tool automatically through the ramp area to the feed-through area.

[0018] Particularly advantageously, the ramp area is arranged such that it sweeps over the same area of ​​the end cap in the circumferential direction as the fastening area. In particular, the ramp area is arranged closer to the filter body than the fastening area. This prevents insertion of the tool into the filter element from detaching the damping element from the end cap. In particular, there is a risk that inserting the tool into the filter element will break the connection between the damping element and the end cap because the tool presses on the locking element of the damping element. This is effectively prevented by the described arrangement of the ramp area. If the tool is inserted into the filter body, the tool first reaches the ramp area of ​​the end cap before it reaches the fastening area of ​​the end cap.The ramp area guides the tool to the feedthrough area, preventing it from reaching the fastening area and thus preventing the damping element from becoming loose.

[0019] It is particularly advantageous for this purpose that the tool receiving area and fastening area are arranged alternately in the circumferential direction of the end cap. Thus, the tool receiving area and fastening area are arranged next to one another. Furthermore, it is particularly advantageous if the damping element has a recess, in particular a kidney-shaped one, at a position lying axially above the tool receiving area. The recess is preferably a through-opening. This also allows the tool to be passed through the damping element, thereby preventing the tool from accidentally detaching the damping element from the end cap. In particular, the tool is rotatable within the recess of the damping element in order to move from the through-passage area to the engagement area.

[0020] The invention further relates to a liquid filter. The liquid filter is, in particular, a fuel filter or a urea filter and is particularly advantageously suitable for use in motor vehicles with internal combustion engines. The liquid filter comprises a filter element as described above and a housing. The filter element is arranged in the housing, wherein the housing has one, in particular a maximum of one, opening through which the filter element can be inserted into the housing or removed from the housing. In particular, the housing is designed as a hollow cylinder, in particular circular cylinder, wherein an end face of the hollow cylinder of the housing is at least partially closed, in particular in such a way that the filter element cannot be removed through the side of the housing having this end face. It is understood that inlet and / or outlet ports for liquid can be provided on this end face.Thus, the filter element can only be inserted into the hollow cylinder via the remaining end face. It is clear that at least one end cap is not directly accessible. The filter element according to the invention is advantageous in this respect because the end cap located furthest axially inside the housing can be grasped with a tool.

[0021] Finally, the invention comprises an arrangement comprising a filter element as described above and a tool. It is provided that the tool can be inserted into the filter element, wherein the tool can be passed through the feed-through region and can be brought into engagement with the end cap of the filter element at the engagement region, preferably the end cap located remote from the opening. In this way, the filter element can be gripped by the tool so that the filter element can be removed from a housing. For this purpose, the tool has at least one engagement element which is advantageously designed to be complementary in shape to the engagement region of the end cap. Thus, a positive connection can advantageously be produced between the tool and the end cap, wherein the positive connection acts at least in one axial direction and in both circumferential directions. Short description of the drawings

[0022] Embodiments of the invention are described in detail below with reference to the accompanying drawings. In the drawing: Figure 1 shows a schematic representation of a filter element 1 according to an embodiment of the invention, Figure 2 shows a schematic representation of an end cap and a damping element of a filter element according to the embodiment of the invention, Figure 3 shows a schematic representation of a liquid filter with a filter element according to the embodiment of the invention, Figure 4 shows a schematic representation of a partial area of ​​a tool for use with the filter element according to the embodiment of the invention, Figure 5 shows a further schematic representation of the tool from Figure 4 , and Figure 6 a schematic representation of the filter element from Figure 1 while using the tool Figure 5 . Embodiments of the invention

[0023] Figure 1shows a filter element 1 according to an embodiment of the invention. The filter element 1 comprises a filter body 2 and an annular end cap 3. The end cap 3 is arranged at an axial end of the filter body 2, wherein the filter body 2 has a hollow cylindrical shape, which is circularly cylindrical in this case. Therefore, all directional information below is given with reference to the hollow cylinder.

[0024] The filter element 1 further comprises an additional second end cap 17, which is arranged axially at an end of the filter body 2 opposite the end cap 3. The additional second end cap 17 is not considered further within the scope of this invention. In particular, it is merely provided that the second additional end cap 17 is annular and has an inner diameter that corresponds at least to the maximum inner diameter of the end cap 3. In the illustrated embodiment, the filter element 1 does not have a support tube in a hollow inner circular cylinder of the filter body 2. Thus, the two end caps 3, 17 are connected to one another only by the filter body 2. This allows the filter element to be manufactured in a particularly simple and cost-effective manner.However, other embodiments also conceivable include filter elements 1 in which a support tube, for example made of plastic, is provided in the hollow interior of the filter body 2, preferably a support tube that is not firmly connected to the end caps 3, 17 and merely absorbs radial forces of the filter body 2, thus preventing the filter body 2 from collapsing. The filter body 2 has an outer filter body diameter on its outside and an inner filter body diameter that corresponds to the diameter of the hollow, circular inner cylinder in the filter body 2.

[0025] The end cap 3 has a tool receiving area 6. The tool receiving area 6 serves to pass through a tool 10 (see Figure 4 and Figure 5 ), whereby the tool holder area 6 is divided into two sections. This is shown in detail in Figure 2 visible.

[0026] Figure 2shows a schematic sectional view through the end cap 3 and through a damping element 7. The end cap 3 and damping element 7 are shown in an exploded view. It can be seen that the end cap 3 has the tool receiving area 6, which is divided into a feed-through area 4 and an engagement area 5. The feed-through area 4 corresponds to a point at which the end cap 3 has a first inner diameter. Particularly advantageously, the first inner diameter is a maximum inner diameter of the end cap 3. The engagement area 5 is an area at which the end cap 3 has a second inner diameter, wherein the first inner diameter is larger than the second inner diameter. In particular, the engagement area 5 is formed by a radially inwardly directed projection 15 being attached to the tool receiving area 6.The engagement region 5 preferably has a trough shape so that the tool 10 can be brought into positive engagement in the engagement region 5.

[0027] Out of Figure 4 and Figure 5 A tool 10 is shown with which the filter element 1 can be gripped. For this purpose, the tool 10 has two engagement elements 12, which are designed in a complementary shape to the shape of the engagement areas 5.

[0028] The tool 10 can thus be passed through the entire filter element 1, whereby the tool 10 can only be passed through the end cap 3 in the feed-through area 4 due to the engagement elements 12. The tool 10 can then be rotated, whereby this is the case with the Figure 2 corresponds to a counterclockwise rotation. The engagement elements 12 can then be positively connected to the engagement area 5. Thus, the filter element 1 can be removed from a housing 11.

[0029] In Figure 3 a liquid filter 14 is shown, which comprises the filter element 1 made of Figure 1which is arranged within a housing 11. It can be seen that the housing 11 has a hollow cylindrical shape, wherein one end face of the hollow cylinder is completely closed except for an inlet opening 16. In order to remove the filter element 1, it must be pulled out through an opening (not shown) within the other end face of the housing 11, not shown. However, if a tensile force is applied in the axial direction to the additional end cap 4, there is a risk that the filter body 2 will be damaged and tear off, so that the end cap 3 will remain within the housing 11. This can be prevented by the tool 10, since the end cap 3 can be gripped with the tool 10. At the same time, the tool 10 allows the filter element 1 to rotate within the housing 11 due to the positive connection between the engagement elements 12 and the engagement area 4.This is particularly helpful when the filter element 1 adheres to the housing 11 due to static friction. In . Figure 6 It is shown how the tool 10 is inserted into the filter element 1, with the engagement elements 12 engaging in the engagement areas 5. In this position, torque can be transferred from the tool 10 to the filter element 1.

[0030] Figure 3 shows that in Figure 2 The damping element 7 shown in FIG. 1 is in a position connected to the end cap 3. The connection between the end cap 3 and the damping element 7 is realized via a fastening area 8 of the end cap and via a locking element 13 of the damping element 7. By means of the fastening area 8 and the locking element 13, a positive connection between the end cap and the damping element 7 can be established, as can be seen from FIG. Figure 3 is evident.

[0031] If the tool 10 is inserted into the filter element 1, there is a risk that the engagement elements 12 will inadvertently detach the damping element 7 from the end cap 3. This is prevented by the provision of a ramp region 9. The number of ramp regions 9 advantageously corresponds to the number of tool receiving regions 6. The ramp region 9 has several advantages: Firstly, the ramp region 9 prevents the tool from removing the damping element 7 from the end cap 3. Furthermore, the ramp region 9 ensures that the tool is always guided to the feed-through region 4. For this purpose, the ramp region 9 extends in the axial direction away from the filter body 2 and in the circumferential direction from an engagement region 5 to an opposite feed-through region 4.The tool 10 can thus be inserted at any point on the filter element 1, whereby an axial force acting on the tool 10 causes the tool 10 to rest against the ramp area 9 and be guided directly through the ramp area 9 to the feedthrough area 4. Thus, the tool 10 can never reach the fastening area 8, which prevents the tool 10 from releasing the locking element 13 from the fastening area 8.

[0032] The damping element 7 also has recesses at those locations axially adjacent to the tool receiving areas 6 of the end cap 3. The recesses are particularly kidney-shaped and advantageously through-openings. Thus, the tool 10 can be passed through both the end cap 3 and the damping element 7 at the feed-through area 4. Likewise, the tool 10 is rotatable when the engagement element 12 is located within the recess of the damping element, in order to guide the engagement element 12 from the feed-through area 4 to the engagement area 5. This prevents the damping element 7 from being accidentally detached from the end cap 3. The recesses also allow the fluid to be filtered to pass through the damping element 7.

[0033] The damping element 7 allows the filter element 1 to be dampened, allowing it to operate even at low temperatures. If the filter element 1 is operated at low temperatures, there is a risk that the liquids being filtered will freeze. By providing the damping element 7, the filter element 1 can compensate for the volume increase as the liquid freezes. For this purpose, the damping element 7 is preferably made of an elastic material so that it can counteract the volume expansion of the liquid by deformation. Destruction of the filter element 1 or the housing 11 due to freezing liquid is thus ruled out.

Claims

1. Filter element (1) comprising: - a hollow filter body (2), and - at least one closure cap (3) which is arranged on an axial end of the filter body (2), - an additional, second closure cap (17) which, axially, is arranged on an end of the filter body (2) that is situated opposite the closure cap (3), - wherein the closure cap (3) has a passage region (4) with a first inner diameter and has an engagement region (5) with a second inner diameter, - wherein the first inner diameter is greater than the second inner diameter, and - wherein a tool (10) is able to be passed from the end situated opposite the closure cap (3) through the entire filter element (1) and through the passage region (4) and is able to be brought into engagement with the closure cap (3) on the engagement region (5), wherein the filter element (1) has a damping element (7) which is fastened to a fastening region (8) of the closure cap (3).

2. Filter element (1) according to the preceding claim, wherein the damping element (7) is made of an elastic material, preferably of rubber.

3. Filter element according to the preceding claim, wherein the damping element (7) is fastened to the fastening region (8) of the closure cap (3) via a latching element (13).

4. Filter element according to one of the preceding claims, wherein the damping element (7) is fastened in a form-fitting manner to the fastening region (8) of the closure cap (3).

5. Filter element according to one of the preceding claims, wherein the damping element (7) has an, in particular kidney-shaped, cutout, wherein the cutout is preferably a passage opening, wherein the cutout is configured in particular such that the tool (10) is rotatable within the cutout of the damping element (7) in order to pass from the passage region (4) to the engagement region (5).

6. Filter element (1) according to one of the preceding claims, characterized in that the hollow filter body is a circular cylinder.

7. Filter element (1) according to one of the preceding claims, characterized in that the engagement region (5) has the form of a trough, a tool (10), in particular, being connectable in a form-fitting manner thereto.

8. Filter element (1) according to one of the preceding claims, characterized in that the passage region (4) is arranged next to the engagement region (5) in the circumferential direction.

9. Filter element (1) according to one of the preceding claims, characterized in that the closure cap (3) has at least two passage regions (4) and at least two engagement regions (5), wherein the closure cap (3) is in particular symmetrical about a central axis.

10. Filter element (1) according to one of the preceding claims, characterized in that the engagement region (5) has a radially inwardly directed projection (15), wherein the second inner diameter is provided at the projection (15).

11. Filter element (1) according to one of the preceding claims, characterized in that the closure cap (3) has a ramp region (9), wherein the ramp region (9) extends axially away from the filter body (2) and in the circumferential direction from the engagement region (5) to the passage region (4).

12. Filter element (1) according to Claim 11, characterized in that the ramp region (9) and the fastening region (8) extend over the same region of the closure cap (3) in the circumferential direction, wherein the ramp region (9) is arranged closer to the filter body (2).

13. Liquid filter (14), in particular a fuel filter or urea filter, comprising a filter element (1) according to one of the preceding claims and comprising a housing (11), wherein the filter element (1) is able to be inserted into the housing (11), or is able to be removed from the housing (11), via an opening, in particular via at most one opening, in the housing (11).

14. Arrangement comprising a filter element (1) according to one of Claims 1 to 12 and comprising a tool (10), wherein the tool (10) is able to be passed from the end situated opposite the closure cap (3) through the entire filter element (1) and through the passage region (4), and is able to be brought into engagement with the closure cap (3) on the engagement region (5), in order to remove the filter element (1) from a housing (11) using the tool (10), and wherein the tool (10) has at least one engagement element (12) which has a shape complementary to the engagement region (5) of the filter element (1).