WO2015192862A1

WO2015192862A1 - Filter unit for an internal combustion engine

Info

Publication number: WO2015192862A1
Application number: PCT/EP2014/001670
Authority: WO
Inventors: Roger BODÉN; Gabriel GUSTAFSSON
Original assignee: Volvo Truck Corporation
Priority date: 2014-06-19
Filing date: 2014-06-19
Publication date: 2015-12-23

Abstract

The invention concerns a filter unit (10, 100) for an internal combustion engine (1), wherein the filter unit (10, 100) comprises a filter housing (11) having a cylindrical shape with a closed first end (12) and means (14, 15) for transfer of a fluid between the filter unit (10, 100) and the engine (1) at a second end (13) of the filter housing (11), wherein the filter unit (10, 100) comprises connection means (16, 101) for fastening the filter unit (10, 100) to an engine structure (2, 102). The invention is characterized in that the filter unit connection means comprises a first connection member (16) positioned at a first circumferential position at the second end (13) of the cylindrical housing (11), wherein the first connection member (16) is configured to form a pivot connection after engagement with a corresponding connection member (6) arranged on the engine structure (2) so as to allow the filter unit (10, 100) to be tilted into its operational position at the engine structure (2) after engagement of the first connection member (16). The invention also concerns an internal combustion engine (1) comprising a filter unit (10, 100) of the above type.

Description

Filter unit for an internal combustion engine

TECHNICAL FIELD

This invention relates to a filter unit for an internal combustion engine, wherein the filter unit comprises a filter housing having a cylindrical shape with a closed first end and means for transfer of a fluid between the filter unit and the engine at a second end of the filter housing, wherein the filter unit comprises connection means for fastening the filter unit to an engine structure. In particular, the invention relates to an oil filter. The invention also relates to an engine provided with such a filter unit.

BACKGROUND OF THE INVENTION

A common type of oil filters for internal combustion engines, a so-called spin- on filter design, consists of a housing/canister with a filter element placed inside. The housing has oil inlet and outlet arranged so that oil that flows from inlet to outlet is forced to pass through the filter element. In a common variant, the inlet and outlet are placed together with each other in one end of the housing with a central opening (usually outlet) surrounded by a number of smaller openings (usually inlets). In such a case the filter element normally has the general shape of a hollow cylinder through which the oil flows in a radial direction.

The housing is mounted either directly on the engine or remotely with supply and return pipes connecting it to the engine. Conventionally, the central opening is provided with threads for connection to a correspondingly threaded end of a pipe that works both as a mounting rod and an oil conduit for leading filtered oil towards the engine. When changing such an oil filter, the housing is unscrewed from its mount, discarded, and replaced with a new one.

When changing such filters it is important that the new filter is correctly connected to avoid oil leakage and even loss of the entire filter during operation of the engine. At the same time it is important to keep the engine service time at a minimum to increase the up-time for a commercial vehicle or working machine, such as a truck, a wheel loader or a marine engine. To ensure a secure connection of a conventional spin-on oil filter, the mechanic performing the engine service needs to spend a relatively long time on properly connecting the filter.

There is thus a need for improved filters or filter connections that reduces the time for changing filter but that still provides for a proper and secure connection of the filter to the engine.

SUMMARY OF THE INVENTION

One object of the invention is to achieve a filter unit, which creates conditions for a time efficient installation and provides for an operationally secure connection of the filter unit to the engine.

The object is achieved by a filter unit for an internal combustion engine, wherein the filter unit comprises a filter housing having a cylindrical shape with a closed first end and means for transfer of a fluid between the filter unit and the engine at a second end of the filter housing, wherein the filter unit comprises connection means for fastening the filter unit to an engine structure, characterized in that the filter unit connection means comprises a first connection member positioned at a first circumferential position at the second end of the cylindrical housing, wherein the first connection member is configured to form a pivot connection after engagement with a corresponding connection member arranged on the engine structure so as to allow the filter unit to be tilted into its operational position at the engine structure after engagement of the first connection member.

Thus, the inventive filter unit can be installed at the engine structure by, in a first step, hooking it onto a hinge-like connection in an inclined position and, in a second step, tilting it into its operational position. The filter unit can then be secured in its operational position in different ways, for instance by using a clamping locking means arranged at the edge of the second end of the filter housing at a position opposite to that of the first connection member, or by placing a blocking means at the filter unit that presses onto the filter housing and prevents the filter unit from tilting back towards its first, inclined position.

Compared to a conventional filter unit, i.e. a threaded filter unit that is screwed into its operational position, the inventive filter unit has several advantages. One advantage is that no time needs to be spent on axially aligning the corresponding threads. Since improper alignment can lead to damaged threads, leakage and even loss of the filter during engine operation, it is an important and typically a time-consuming step during filter installation to make sure that the alignment is correct. A further advantage is that a threaded filter units usually requires to be fastened with a rather high and defined torque which in turn makes it necessary to make use of special tools for turning the filter and for measuring the torque applied. In contrast, the inventive filter unit can simply and quickly be tilted/swung into its operational position with less force needed and without the need for special tools. Further, the inventive filter unit can be uninstalled by unlocking, tilting back and disconnecting the first connection member without the need for particular tools for loosening any threaded connection.

All in all, a filter unit of the inventive type simplifies and speeds up the process of changing engine filter unit(s) compared to conventional filter units. It also makes the connection of the filter unit more safe as the mechanic carrying out the engine service does not need to rely on a "right performed turn-to-torque", or "until seal touches and another ¾ turn" as is installation standard for many oil filters of today. In contrast, the inventive filter unit is tilted into a clear and defined operational position. Preferably, the filter unit (and/or the engine structure) is provided with radial sealings so as to allow a play in the axial position of the filter unit (and/or a play in the tilting angle) when it is set in its operational position. Such a play can be used to simplify securing and release of the filter unit in/from its operational position. During operation of the engine the high fluid (oil) pressure will press onto the filter unit in an axial direction away from the engine structure, i.e. the filter unit will be forced into an end position of any play and will stay in that position. The connection and securing means thus primarily need to prevent the filter unit from moving axially away from the engine structure (besides holding the filter unit in place in a radial direction).

In an embodiment of the invention the first connection member is arranged at an edge of the second end of the filter housing. Preferably, the first connection member comprises a part that protrudes radially from the second end. Such a design is relatively simple and it facilitates tilting/swinging the filter unit into the operational position. The protruding part may form part of a flange that surrounds the filter housing at the second end thereof.

In an embodiment of the invention the first connection member comprises a groove or a pin adapted to fit onto or into a corresponding pin or groove, respectively, arranged onto the engine structure. This forms a suitable hingelike connection. The pin may be a protrusion or similar and does not have to be a separate pin or other separate detail. Preferably, the groove or pin extends in a direction substantially parallel to a tangent to the cylindrical filter housing and substantially perpendicular to a longitudinal axis of the filter housing. The groove or pin forms the pivot axis which preferably is arranged in this way. In a variant of the invention, the first connection member comprises a groove, and wherein the groove faces the first end of the filter housing. In an embodiment of the invention the fluid transfer means comprises a cylindrical conduit provided with a first circumferential sealing configured to provide a radial seal against a corresponding part of the engine structure when the filter unit is in its operational position. A cylindrical conduit is useful for connecting the filter unit to a corresponding conduit arranged at the engine structure, where the conduit of the filter unit may be inserted into a larger conduit or be passed onto a smaller conduit. As mentioned above, a radial sealing allows for an axial play and no need for particular detailed adjustments of the axial position of the filter unit. In a variant of the invention, the cylindrical conduit protrudes from the second end of the filter housing.

In an embodiment of the invention the filter unit comprises a second circumferential sealing that surrounds the second end of the filter housing. Preferably, the second circumferential sealing extends around the filter housing at the second and thereof and provides a radial seal against a corresponding part of the engine structure when the filter unit is in its operational position. Such a sealing seals off the fluid transfer means and allows oil or other fluid to be transferred between the filter unit and the engine via, for instance, a cylindrical conduit as mentioned above (filter outlet) and openings in the second end of the filter housing (filter inlet). No axial sealings are thereby required. In a variant, the second circumferential sealing is arranged between the flange and the second end of the filter housing.

In an embodiment of the invention the filter unit comprises a second connection member for securing the filter unit to the engine structure after tilting the filter unit into its operational position. This can be needed if the filter unit cannot be prevented from swinging back from its operational position by e.g. a blocking means arranged onto the engine structure. Preferably, the second connection member is positioned at a second circumferential position at the second end of the cylindrical housing. Preferably, the second connection member is positioned on the opposite side of the second end of the filter housing in relation to the first connection member. Such a symmetric distribution of the connections is advantageous.

It is possible to use more than one first and/or second connection member. The second connection member may comprise a groove or recess provided at a lower side (i.e. facing the closed first end of the filter housing) of a protruding part, in similarity with what is mentioned above concerning the first connection member. In an embodiment of the invention the fluid transfer means comprises a set of openings arranged in the second end of the filter housing.

In an embodiment of the invention the filter housing encloses a filter chamber and wherein the filter unit is arranged so as to lead the fluid to and from the filter unit via the filter chamber.

In an embodiment of the invention the filter unit is configured for filtering an engine oil. A further object of the invention is to achieve an engine structure, which creates conditions for a time efficient filter unit exchange and provides for an operationally secure connection of the filter unit to the engine.

The object is achieved by an engine structure for holding a filter unit, wherein the engine structure comprises connection means for fastening the filter unit characterized in that the connection means comprises a connection member, which is configured to form a pivot connection after engagement with a corresponding first connection member at a second end of the filter unit so as to allow the filter unit to be tilted into its operational position at the engine structure after engagement of the first connection member. In an embodiment of the invention, the connection means comprises a blocking member configured to engage with a first end of the filter unit in order to block the filter unit when set in its operational position at the engine structure.

In a further embodiment of the invention, the connection means comprises a holding member adapted to engage with a second connection member at the second end of the filter unit, wherein the second connection member is circumferentially spaced from the first connection member

The invention also relates to an internal combustion engine comprising a filter unit of the above typ.

BRIEF DESCRIPTION OF DRAWINGS

In the description of the invention given below reference is made to the following figure, in which:

Figure 1 shows an internal combustion engine provided with three filter units according to a first embodiment,

Figure 2 shows the filter units of figure 1 where one of the filter units is only partly installed,

Figures 3a-3d show a step-by-step installation of a filter unit according to figures 1-2,

Figure 4 shows a cross-section of an installed filter unit according to figures 1-3,

Figures 5a-5c show a step-by-step installation of a filter unit according to a second embodiment,

Figure 6 shows a cross-section of an installed filter unit according to figures 5a-5c. DESCRIPTION OF EXAMPLE EMBODIMENTS OF THE INVENTION

Figure 1 shows an internal combustion engine 1 provided, at an engine structure 2, with three oil filter units 10 that in this example are identical and forms a first embodiment of the inventive filter unit.

Figure 2 shows the filter units 10 of figure 1 slightly from beneath. The filter unit 10 to the right is in an inclined position about to be installed into its operational position via a tilting motion (indicated by the two upper arrows). A further arrow indicates the upwards motion of a blocking member 3 used to block the filter unit 10 when set in its operational position at the engine structure 2. The two filter units 10 at the left are already set in their operational position with their corresponding blocking members 3 set in their blocking position.

Figures 3a-3d show a step-by-step installation of a filter unit 10 according to figures 1-2, and figure 4 shows a cross-section of an installed filter unit 10 according to figures 1-3.

As can be seen in figures 2-4, each filter unit 10 comprises a filter housing 11 having a cylindrical shape with a closed first (lower) end 12 and a second (upper end) 13. The second end 13 is provided with means in the form of openings 14 and an axially protruding cylindrical conduit 15 for transfer of oil between the filter unit 10 and the engine 1. The cylindrical conduit 15 is positioned centrally at the second end 13 and the openings 14 are distributed around the conduit 15. When the engine 1 is in operation, oil enters the filter housing 11 via the openings 14, passes a filter element (not shown) inside the filter housing 11 , and exits the filter housing 11 via the cylindrical conduit 15.

The filter unit 10 further comprises connection means in the form of a first connection member 16 for fastening the filter unit 10 to the engine structure 2. The first connection member 16 is positioned at an edge at a first circumferential position at the second end 13 of the cylindrical housing 11. Further, the first connection member 16 is arranged on a part of a flange 17 that protrudes radially from the second end 13 and that surrounds the filter housing 11 at the second end 13 thereof.

The first connection member 16 comprises a groove adapted to fit onto a corresponding pin 6 arranged onto the engine structure 2. The groove faces the first end 12 of the filter housing 11 and extends in a direction substantially parallel to a tangent to the cylindrical filter housing 11 and substantially perpendicular to a longitudinal axis of the filter housing 11. The pin 6 extends in a corresponding direction at the side of the intended operational position of the filter unit 10 and is arranged with its upper side free for connection with the connection groove 16. A space 7 is arranged above and at the sides of the pin 6 to give room for the connection member 16 when installing the filter unit 10.

The connection member 16 (the groove) is adapted to fit onto the upper side of the pin 6 such as to form a pivot connection after engagement with the pin 6 (where the pin 6 forms the axis of rotation). The filter unit 10 can thus be hooked up onto the pin 6 and then tilted into its (in this example vertical) operational position at the engine structure 2 after engagement of the first connection member 16.

The cylindrical conduit 15 is provided with a first circumferential sealing 18 arranged on an outside of the conduit 15. The first circumferential sealing 18 provides a radial seal against an inside of a corresponding engine conduit 8 of the engine structure 2 when the filter unit 10 is in its operational position and the cylindrical conduit 15 is inserted into the engine conduit 8 (see figure 4).

The filter unit 10 further comprises a second circumferential sealing 19 that surrounds the second end 13 of the filter housing 11. In particular, the second circumferential sealing 19 extends around the filter housing 11 at the second end 13 thereof and provides a radial seal against an inside of a corresponding casing 4 of the engine structure 2 when the filter unit 10 is in its operational position (see figure 4). In the example shown, the second circumferential sealing 19 is arranged between the flange 17 and the second end 13 of the filter housing 11.

When in operation, unfiltered oil flows from the engine 1 via channels 9 in the engine structure casing 4 into the casing 4 and further via openings 14 into the filter housing 11. Filtered oil flows out from the filter housing 11 via the circular conduit 15 and the engine conduit 8 to the engine 1. See figure 4.

Figure 3a shows an initial step of the installation procedure where the filter unit 10 is moved towards the engine structure in an inclined position with the connection member 16 aiming at being engaged with the pin 6.

In figure 3b, the connection member 16 has been engaged with the pin 6 so that a hinge-like connection has been formed. The filter unit 10 is in an inclined positioned and can now be tilted into its vertical operational position (indicated by arrow) with a pivot axis formed by the groove-pin connection.

In figure 3c, the filter unit 10 has been tilted into its operation position with the sealings 18, 19 forming radial seals inside the casing 4 and with the flange 17 pressing onto a lower edge of the casing 4 at a circumferential position opposite to that of the connection member 16 and the pin 6. An arrow indicates that the blocking member 3 can be moved, in this case upwards, to block the position of the filter unit 10 (i.e. to prevent the filter unit 10 from tilting back into its inclined position).

In figure 3d, the blocking member 3 is positioned between a lower part of the filter unit 10 and a part of the engine structure 2 so as to hold the filter unit 10 in place. The filter unit 10 is now secured in its operational position. The blocking member 3 is guided by means of a guiding structure 20 for movement in an axial direction between a lower, inactive position and an upper active position, in which it holds the filter unit 10 in place. The guiding structure 20 comprises a stop 21 for limiting a movement of the blocking member downwards in the axial direction, which stop defines the lower, inactive position. Further, the guiding structure 20 comprises an axially directed slot for guiding the blocking member 3. More specifically, the guiding structure 20 comprises two parallel side walls 22,23 extending in the axial direction and spaced in a transverse direction for defining the slot.

The blocking member 3 comprises an upper portion 24 with an acute end for introduction between the free end of the filter unit 10 and a wall 25 of the engine structure facing the filter unit 10, see figure 3c and 3d.

Further, the blocking member 3 comprises a handle portion 26 configured for manually moving the blocking member 3 between the active position and the inactive position. The handle portion 26 protrudes transversally between the side walls 22,23.

The blocking member 3 is formed as a one-piece unit.

The wall 25 of the engine structure facing the filter unit 10 in its operational position forms a recess for receiving the free end of the filter unit 3 during the installation procedure, see figure 3b.

Figure 4 shows a sectional view of the filter's secured operational position.

Figures 5a-5c show a step-by-step installation of a filter unit 100 according to a second embodiment. Figure 6 shows a cross-section of an installed filter unit 100 according to figures 5a-5c. Most parts of figures 5-6 are similar to what has been described in relation to figures 1-4 and therefore the same reference numbers are given for these parts in figures 5-6. What differs is that the filter unit 100 according to the second embodiment comprises a second connection member 101 for securing the filter unit 100 to the engine structure after tilting the filter unit 100 into its operational position, and that the engine structure (now denoted 102) is provided with a pivoted holding member 105 adapted to engage with the second connection member 101. The second connection member 101 is positioned at a second circumferential position at the second end 13 of the cylindrical housing 11 , at a circumferential distance from the first connection member 16. In this example, the second connection member 101 is positioned on the opposite side of the second end 13 of the filter housing 11 in relation to the first connection member 16.

In similarity with the first connection member 16: the second connection member 101 is arranged at an edge of the second end 13 of the filter housing 11 ; the second connection member 101 comprises a part that protrudes radially from the second end 13; the protruding part forms part of a flange 17 that surrounds the filter housing 11 at the second end 13 thereof; and the second connection member 101 comprises a groove adapted to fit onto a corresponding pin arranged onto the engine structure. The flange 17 is configured to form both the protruding part forming the first connection member 16 and the protruding part forming the second connection member 101. The flange 17 may be configured to completely surround the filter housing 11. According to the shown embodiment, the flange 17 is continuous in the circumferential direction. According to an alternative, the flange 17 is discontinuous in the circumferential direction. In this case the corresponding pin is arranged at an end part 107 of the pivoted holding member 105 that is arranged onto a further pin 106 that forms the pivot axis. Figure 5a shows the filter unit 100 hooked up in an inclined position with the first connection member 16 engaged with the pin 6 of the engine structure 102 (in similarity with figure 3b).

Figure 5b shows the filter unit 100 tilted up into its operational position (similar to figure 3c). To facilitate the positioning of the end part 107 of the holding member 105 under the second connection member 101 , the filter unit 100 has been turned/lifted as far as possible towards the casing 4. This is indicated by the large arrow on the filter unit 100. Further arrows indicate that the holding member 105 can be turned so that the pin or protrusion arranged at the end part 107 can swing in under the second connection member 101.

In figure 5c, the filter unit 100 has been released and allowed to move somewhat downwards so as to allow engagement between the end part 107 of the holding member 105 and the second connection member 101. The filter unit 100 is now secured in its operational position.

Figure 6 shows a cross section of the filter unit 100 secured in its operational position at the engine structure 102. As can be seen in figure 6, there is a small axial play above the flange 17. By pressing the filter unit 100 upwards towards the casing 4, so that the flange 17 presses onto the underside of the casing 4, the holding member 105 can easily be engaged with (or disengaged from) the second connection member 101. During operation of the engine 1 the high oil pressure will apply a force onto the filter unit 100 in a direction away from the casing 4 (downwards in figure 6, and in figure 4) which means that the filter unit 100 will stay in place. Most parts in figure 6 are the same as in figure 4 and are therefore not further described here.

The engine structure 2, 102 may also be called a filter head or mounting base. The engine structure may be formed by a separate unit, which is fastened to the internal combustion engine. According to an alternative, the engine structure may be formed integrally with the internal combustion engine. The invention is not limited by the embodiments described above but can be modified in various ways within the scope of the claims. For instance, the detailed structure of the connection members 16, 101 may be varied. Also the holding member 105 and the blocking member 3 may be designed in another way than showed above. Further, both holding members and blocking members may be used to secure the same filter unit in its operational position. Further, the circular conduit 15 may be adapted to receive a corresponding part (instead of being adapted to be inserted into a corresponding part), and may extend at least partly into the filter housing 11. If so, the first circumferential sealing should be arranged on the inside of the circular conduit 15.

The invention has above been described for an oil filter unit. The invention is however not limited to a filter unit for filtering an engine oil, but may be applied for filtering other fluids, such as a fuel or coolant for the internal combustion engine.

Claims

CLAIMS 1. A filter unit (10, 100) for an internal combustion engine (1), wherein the filter unit (10, 100) comprises a filter housing (11) having a cylindrical shape with a closed first end (12) and means (14, 15) for transfer of a fluid between the filter unit (10, 100) and the engine (1) at a second end (13) of the filter housing (11), wherein the filter unit (10, 100) comprises connection means (16, 101) for fastening the filter unit (10, 100) to an engine structure (2, 102), c h a r a c t e r i z e d i n

that the filter unit connection means comprises a first connection member (16) positioned at a first circumferential position at the second end (13) of the cylindrical housing (11),

wherein the first connection member (16) is configured to form a pivot connection after engagement with a corresponding connection member (6) arranged on the engine structure (2) so as to allow the filter unit (10, 100) to be tilted into its operational position at the engine structure (2, 102) after engagement of the first connection member (16).

2. A filter unit (10, 100) according to claim 1 , wherein the first connection member (16) is arranged at an edge of the second end (13) of the filter housing (11).

3. A filter unit (10, 100) according to claim 1 or 2, wherein the first connection member (16) comprises a part that protrudes radially from the second end (13).

4. A filter unit (10, 100) according to claim 3, wherein the protruding part forms part of a flange (17) that surrounds the filter housing (11 ) at the second end (13) thereof.

5. A filter unit (10, 100) according to any of the above claims, wherein the first connection member (16) comprises a groove or a pin adapted to fit onto or into a corresponding pin (6) or groove, respectively, arranged onto the engine structure (2).

6. A filter unit (10, 100) according to claim 5, wherein the groove or pin of the first connection member (16) extends in a direction substantially parallel to a tangent to the cylindrical filter housing (11) and substantially perpendicular to a longitudinal axis of the filter housing (11).

7. A filter unit (10, 100) according to claim 5 or 6, wherein the first connection member (16) comprises a groove, and wherein the groove faces the first end (12) of the filter housing (11).

8. A filter unit (10, 100) according to any of the above claims, wherein the fluid transfer means (14, 15) comprises a cylindrical conduit (15) provided with a first circumferential sealing (18) configured to provide a radial seal against a corresponding part of the engine structure (2, 102) when the filter unit (10, 100) is in its operational position.

9. A filter unit (10, 100) according to claim 8, wherein the cylindrical conduit (15) protrudes from the second end (13) of the filter housing (11).

10. A filter unit (10, 100) according to any of the above claims, wherein the filter unit (10, 100) comprises a second circumferential sealing (19) that surrounds the second end (13) of the filter housing (11).

11. A filter unit (10, 100) according to claim 10, wherein the second circumferential sealing (19) extends around the filter housing (11) at the second end (13) thereof and provides a radial seal against a corresponding part of the engine structure (2, 102) when the filter unit (10, 100) is in its operational position.

12. A filter unit (10, 100) according to claims 4 and 11 , wherein the second circumferential sealing (19) is arranged between the flange (17) and the second end (13) of the filter housing (11).

13. A filter unit (100) according to any of the above claims, wherein the filter unit (100) comprises a second connection member (101) for securing the filter unit (100) to the engine structure (102) after tilting the filter unit (100) into its operational position.

14. A filter unit (100) according to claim 13, wherein the second connection member (101) is positioned at a second circumferential position at the second end (13) of the cylindrical housing (11).

15. A filter unit (100) according to claim 14, wherein the second connection member (101) is positioned on the opposite side of the second end (13) of the filter housing (11) in relation to the first connection member (16).

16. A filter unit (100) according to any of claims 13-15, wherein the second connection member (101) is arranged at an edge of the second end (13) of the filter housing (11).

17 A filter unit (100) according to any of claims 13-16, wherein the second connection member (101) comprises a part that protrudes radially from the second end (13).

18. A filter unit (100) according to any of claims 13-17, wherein the protruding part forms part of a flange (17) that surrounds the filter housing (11) at the second end (13) thereof.

19. A filter unit (100) according to any of claims 13-18, wherein the second connection member (101) comprises a groove or a pin adapted to fit onto or into a corresponding pin (107) or groove, respectively, arranged onto the engine structure (102).

20. A filter unit (10, 100) according to any of the above claims, wherein the fluid transfer means comprises a set of openings (14) arranged in the second end (13) of the filter housing (11 ).

21. A filter unit (10, 100) according to any of the above claims, wherein the filter housing (11) encloses a filter chamber and wherein the filter unit (10, 100) is arranged so as to lead the fluid to and from the filter unit (10, 100) via the filter chamber.

22. A filter unit (10, 100) according to any of the above claims, wherein the filter unit (10, 100) is configured for filtering an engine oil.

23. An engine structure (2,102) for holding a filter unit (10,100), wherein the engine structure comprises connection means (3,6,105) for fastening the filter unit (10, 100) c h a r a c t e r i z e d i n

that the connection means (3,6,105) comprises a connection member (6), which is configured to form a pivot connection after engagement with a corresponding first connection member (16) at a second end (13) of the filter unit (10,100) so as to allow the filter unit (10, 100) to be tilted into its operational position at the engine structure (2) after engagement of the first connection member (16).

24. An engine structure (2) according to claim 23, wherein the connection means (3) comprises a blocking member (3) configured to engage with a first end (12) of the filter unit (10) in order to block the filter unit (10) when set in its operational position at the engine structure (2).

25. An engine structure (102) according to claim 23, wherein the connection means (105) comprises a holding member (105) adapted to engage with a second connection member (101) at the second end (13) of the filter unit, wherein the second connection member (101) is circumferentially spaced from the first connection member (16).

26. Internal combustion engine (1),

characterized in

that it comprises a filter unit (10, 100) according to any one of claims 1-22.

27. Internal combustion engine (1) according to claim 26, wherein the engine (1) is provided with an engine structure (2) according to any one of claims 23- 25.