FR2900350A1 - OIL FILTRATION DEVICE FOR AN INTERNAL COMBUSTION ENGINE AND MOTOR COMPRISING SUCH A DEVICE - Google Patents

Abstract

The oil filtering device is intended for an internal combustion engine and comprises a filter body comprising fixing means on the engine and arranged to support a complementary filter for filtering the oil circulating in a bypass circuit (71). . The filter body (10, 10 ') forms a chamber containing the complementary filter (20) and has an oil inlet duct (14) opening into an upper part (12) of the filter body on which the complementary filter (20) is connected, to feed the complementary filter in its upper part, and a cover (30, 30 ') for holding and sealing is removably attached to the lower end of the filter body.

Description

1 Oil filter device for an internal combustion engine and

  engine comprising such a device.

  The present invention relates to an oil filtering device for an internal combustion engine. It relates more particularly to filtration devices comprising a complementary filter, such as a centrifugal filter or a so-called fine-pore filter, mounted as a bypass of the main filter on the lubrication circuit. Such complementary filters are used in addition to a conventional main oil filter, for separating the carbonaceous material particles from the engine oil, ensuring a filtration that can be finer than that obtained by the conventional filter connected in series in the lubrication circuit.

  Figure 1 schematically illustrates a typical lubricating oil circuit in an engine, when using such type of filtration. In a main circuit 9, the oil 1 contained in an oil sump 2 of the engine is pumped by an oil pump 3, passes into a cooling module 4 and then through a conventional oil filter 5, for example type filter element paper, and is finally directed under pressure to the various bodies to be lubricated 6, symbolized in this diagram by a crankshaft, before returning to the housing 2.

  A complementary filter 7, centrifugal or fine-pore, is connected bypass on the circuit that has just been mentioned, between the pump 2 and the conventional filter 5, so that a portion of the pumped oil passes only in the additional filter before returning directly to the engine oil sump. This additional filter thus makes it possible to purify the oil by fine filtration, without creating a pressure drop on the circuit supplying the bodies to be lubricated 6. To improve the filtration while reducing the pressure losses, due to the viscosity of the oil. In the bypass circuit comprising the complementary filter 7, this bypass circuit 71 is generally transited on the main circuit upstream of the cooler 4, where the hotter oil is less viscous.

  In general, the oil filters, whether of the conventional type or complementary as indicated above, are attached elements fixed on the engine block and connected to the oil circuits thereof. The problem of their implementation is complicated by the fact that it is necessary to have a fairly easy access to the filter for its maintenance, cleaning and / or filter cartridge change, requiring disassembly and reassembly operations that it is desirable to make it as easy and fast as possible. In addition, it seeks to reduce the size of all the filters to facilitate their implementation, and to limit the overall size of the motor unit to provide the space under hood necessary for safety reasons in the whole of the vehicle on which the engine is installed.

  Centrifugal filters are already known, for example from US-6530872. Such filters

  3 comprise a rotor placed inside a fixed cover adapted, for example by screwing, on a support. The rotor is guided in rotation in bearings located respectively on said support and in the bottom of the lid. The oil arrives under pressure in a central tube of the rotor, from bottom to top, passing through an axial orifice formed in the support and through the lower bearing located in said support. The rotation of the rotor is ensured by the flow of oil which passes into adapted holes in the form of fins, located in the upper part of the central tube, before being projected onto the inner cylindrical surface of the rotor side wall. , where the particles are deposited under the effect of the centrifugal force. The oil separated from the carbonaceous materials thus deposited by centrifugation flows along the side wall of the rotor and is collected in the lower part of the rotor, from where it is discharged through small holes to a return circuit arranged in the support .

  A disadvantage of such a filter lies in its location on the engine, which is necessarily by the lower part, thus imposing limitations on the implementation, which can lead to the creation of complex supply and return oil circuits, likely to create high losses. In addition Accessibility for filter maintenance needs is limited by the need for access from the top to disassemble the lid.

  These disadvantages are found in filtration systems combining a conventional main filter and a complementary filter, whether centrifugal or fine-pore. Such filtration assemblies are already known from WO-2004007052 and WO-2005018775. In addition, in the systems of these documents, it is necessary to disassemble the centrifugal filter from above, before it can also extract from above the filter cartridge of the main filter, located under the centrifugal filter. EP-1260260 also describes a filter assembly associating a main filter, located in the lower part and surmounted by a bypass filter. To the drawbacks mentioned above, this system adds that the oil arrives in the assembly by one and the same conduit, preventing an assembly such as that of Figure 1 for example, where the oil inlets are respectively upstream and downstream of the cooler.

  The present invention aims to solve these problems and aims in particular to provide a compact filtration device, easy assembly and reassembly to facilitate the maintenance operations required, and to improve the flow of oil in the assembly of the filtration device.

  With these objectives in view, the subject of the invention is an oil filtration device for an internal combustion engine, having in particular a main oil circuit provided with a main filter in series, the device comprising a filter body. comprising fastening means on the engine and arranged to support a filter, called complementary filter, for filtering the oil flowing in a circuit connected to the oil circuit bypassing the main filter. According to the invention, this filtering device is characterized in that the filter body defines a chamber containing the complementary filter and defines an oil inlet duct opening on the one hand in the filter body fixing means. on the motor and on the other hand in an upper part of the filter body on which the complementary filter is connected, for supplying the complementary filter in its upper part, and in that a holding and sealing cover is fixed by Removable way on the lower end of the filter body.

  Thus, as will be better understood later, the filter body, fixed permanently on the motor by said fixing means, for example conventionally by a fastening flange, comprises a side wall, of generally cylindrical shape. vertical axis, and is closed in the upper part by an upper wall, substantially horizontal as a whole, to form a kind of bell that defines the said chamber, the filter body having an opening in the lower part, by which the complementary filter can be removed after removal of the lid. The assembly and disassembly of the filter can thus be made easily from below.

  The oil inlet duct is preferably made in the same wall of the filter body, when producing it in the foundry. Said duct connects, passing through the side wall of the filter body, an oil inlet orifice located at the fastening flange, with an orifice located for example in the central part of the upper wall in which the duct finish and on which the complementary filter is connected when it is mounted in the filter body. An oil outlet conduit connects the interior of the filter body, at the bottom, to an outlet port at the flange. The oil outlet duct opens inside the filter body above a wall, preferably inclined, closing the lower end of the chamber containing the complementary filter.

  According to one particular arrangement, the filter body is arranged in such a way as to also house a main filter, arranged under the complementary filter, between the complementary filter and the lid, a partition wall being removably disposed in the chamber of the body of the filter for separating it sealingly between an upper chamber containing the complementary filter and a lower chamber containing the main filter, the partition wall serving as a support for the complementary filter, and inlet and outlet conduits connecting the lower chamber and the fixing means of the filter body on the engine.

  Thus, the same filter body integrates the main filter and the complementary filter. The mounting flange integrates the oil inlet and outlet ducts for the two compartments corresponding to the two filters. The partition wall seals between the two compartments and their respective ducts. This wall can slide in the body, so as to allow the extraction of the two filters, either simultaneously or one after the other.

  The invention also relates to an internal combustion engine comprising a filtration device as defined above, fixed on the engine block by a flange ensuring the passage of oil between the engine block and a chamber of the filter body . The invention also relates to an internal combustion engine comprising a filtration device as defined above, fixed on the engine block by a flange ensuring the passage of oil between the engine block and each filter of the filtration device , independently.

  Other features and advantages will appear in the description that will be made of a first embodiment of a filter device according to the invention, comprising only a centrifugal filter, and a second embodiment comprising a filter centrifugal combined with a conventional filter cartridge filter.

  Reference is made to the accompanying drawings, in which: FIG. 1 is a diagrammatic view of a filtration circuit comprising a main filter and a complementary filter, and has already been commented on in the introduction of this memo; FIG. an axial sectional view of the filtration device according to the first embodiment, - Figure 3 is an axial sectional view of the filter device according to the second embodiment.

  The filtration device of Figure 2 comprises a filter body 10 of generally cylindrical shape and substantially vertical axis when placed on a motor. The filter body is made by molding and comprises a side wall 11 and a transverse upper wall 12 delimiting a housing for a centrifugal filter 20, and it is open in the lower part, the opening being able to be sealed by a lid 30.

  The centrifugal filter 20, of general principle known per se, is rotatably mounted along the axis of the body on an upper bearing 21 arranged in the upper wall 12 and a lower bearing 22 arranged on the cover 30. It comprises in the lower part orifices 23 of oil outlet arranged to allow the flow of oil out of the centrifugal filter. Specifically to the invention, the centrifugal filter 20 comprises an upper oil inlet duct 24, coaxial with the bearing 21, which opens into the interior of the centrifugal filter, in its upper part, by lateral orifices 25. circumferentially distributed and arranged to form fins 26, in a manner known per se, able to cause the rotation of the filter under the effect of the flow of oil into the filter.

  The filter body further comprises a flange 13 for attachment to the engine block, and an oil inlet duct 14 and an oil outlet duct 15, preferably obtained during molding of the body.

  The oil inlet duct 14 is designed to extend from the flange 13, where it is placed in communication with an internal oil duct of the engine block, not shown, to a central orifice 121 arranged in the upper wall 12, passing along the side wall 11. The central orifice 121 of the filter body is in communication with the conduit 24 of the centrifugal filter when the latter is mounted on its bearings in the filter body.

  The oil outlet duct 15 extends from the flange 13 to the interior space of the body, just above the cover 30, and therefore at the bottom of the housing of the centrifugal filter. The upper face 31 of the lid is inclined towards the outlet duct 15, and is flush in its lowest part with said outlet duct 15.

  The operation of the filter is as follows, the oil flowing according to the arrows mentioned in Figure 2: the oil from the engine block enters the filter body through the flange 13, flows in the conduit 14 and passes through the filter. central orifice 121 and the duct 24 of the centrifugal filter. By the arrangement of the lateral orifices 25 and fins 26, the oil flow is projected towards the side wall 27 of the centrifugal filter, and causes

  10 passing over the fins a rotational torque of the entire centrifugal filter, in a manner known per se. The oil flows along the side wall while the particles remain there adhered by the centrifugal force. The oil is collected in the bottom of the centrifugal filter, from which it leaves through the outlet orifices 23, flows on the upper face 31 of the lid 30 and joins the outlet duct 15.

  Thanks to the arrival of the oil in the upper part of the centrifugal filter, we benefit from gravity to improve oil filtration. Moreover, the production of the oil inlet duct on the side of the filter body gives a greater flexibility of realization that if the oil circuit passes inside the body, as in the prior art, and thus makes it possible to reduce the pressure losses in the filtration circuit.

  The filtration device of Figure 3 also comprises a filter body 10 'of generally cylindrical shape and substantially vertical axis when it is placed on a motor. As in the first embodiment, the filter body is made by molding. In this embodiment, the filter body 10 'is more elongated and comprises an upper chamber 16 which incorporates the centrifugal filter 20, arranged as in the first embodiment, as can be seen in the figure, and a lower chamber 17, constituting the main filter and in which is housed a filter cartridge 40 of conventional type, supported by the cover 30 'for closing the filter body.

  Both chambers are sealed by a partition wall 50, whose inclined top face 51 carries the lower bearing 22 of the centrifugal filter. The partition wall further comprises a plate 52 arranged to hold the filter cartridge 40 pressed against the lid 30 '. A peripheral seal 55 seals between this plate and the filter body, in order to hermetically separate an upper zone 17 'from the lower chamber 17 from the remainder of said lower chamber 17. Orifices 53 are pierced in a collar 54 connecting the plate 52 to the partition wall 50, for communicating the interior 41 of the cartridge 40 with an upper zone 17 'of the lower chamber 17. A second oil inlet duct 18 is formed in the flange of fastening 13 'and opens into said upper zone 17'. A second outlet duct is also produced in the flange 13 'and opens into the chamber 17, between the cover 30' and the plate 52.

  Note that, although made in the same room constituting the filter body, the two filters have their respective independent oil inlets and outlets, allowing in particular the connection of the two filters on the engine block by a single attachment flange 30 ' , but allowing the two filters to be placed independently in the filtration circuit, for example on either side of a cooling device, as illustrated in the diagram of FIG.

  As shown by the arrows in FIG. 3, the oil of the main circuit enters the filter body via the conduit 18, arrives in the upper space 17 'of the lower chamber, passes through the orifices 53 and arrives at the 40. The oil passes through this cartridge and leaves the filter body through the conduit 19.

  The bypass oil circuit passes through the centrifugal filter 20, as indicated for the first embodiment.

  For the maintenance of the filtration device, there is direct access to the filter cartridge 40 after removal of the lid 30 '. For the maintenance of the centrifugal filter, the partition wall 50 and then the centrifugal filter 20 are then removed from below.

  Although in the two examples described above the complementary filter is a centrifugal filter, it will easily be understood that the latter could equally well be replaced by a fine-pore filter providing the same functions.

Claims (12)

  An oil filtering device for an internal combustion engine, the device comprising a filter body comprising fixing means on the engine and arranged to support a filter, called a complementary filter, for filtering the oil circulating in a circuit. bypass (71), characterized in that the filter body (10, 10 ') defines a chamber containing the filter (20) and defines an oil inlet duct (14) opening on the one hand in the means (13, 13 ') for fixing the filter body on the motor and on the other hand in an upper part (12) of the filter body to which the filter (20) is connected, for feeding the filter in its upper part, and in that a cover (30, 30 ') is removably attached to the lower end of the filter body.   Filtration device according to claim 1, characterized in that the filter body (10 ') is arranged to also house a main filter (40) arranged under the complementary filter (20) between the complementary filter. and the cover (30 '), a partition wall (50) being detachably disposed in the filter body for sealingly separating it between an upper chamber (16) containing the complementary filter (20) and a lower chamber ( 17) containing the main filter (40).   3. Filtration device according to claim 2, characterized in that the partition wall (50) serves as a support for the complementary filter (20), and inlet (18) and outlet (19) conduits connect the lower chamber (17) and means (13 ') for fixing the filter body on the engine.   4. Filtration device according to any one of claims 1 to 3, characterized in that the filter body (10, 10 ') comprises a side wall (11) and an upper wall (12), and the conduit of oil inlet (14) opens into an orifice (121) located in the central part of the upper wall and on which the complementary filter (20) is connected when it is mounted in the filter body   5. Filtration device according to any one of claims 1 to 4, characterized in that the oil inlet duct (14) is formed in the same wall of the filter body.   6. Filtration device according to any one of claims 1 to 5, characterized in that an oil outlet duct (15) opens inside the filter body above an inclined wall closing the end lower chamber containing the complementary filter (20).   7. Filtration device according to any one of claims 1 to 6, characterized in that the complementary filter is a centrifugal filter (20), rotatably mounted on the upper wall (12) by a bearing (21) and having a duct upper oil inlet (24), coaxial with the bearing (21) and which opens into the centrifugal filter in its upper part by lateral orifices (25).   8. Filtration device according to any one of claims 1 to 6, characterized in that the complementary filter is a fine-pore filter.   9. Filtration device according to claim 3, characterized in that the partition wall (50) comprises a plate (52) arranged to hold a main filter cartridge (40) pressed against the lid (30 ') and delimit a zone upper portion (17 ') of the lower chamber (17) and sealing between the upper zone (17') and the remainder of the lower chamber (17), orifices (53) are pierced in a collar (54) connecting the plate (52) to the partition wall (50), for communicating the interior (41) of the cartridge (40) with the upper zone (17 '), a second oil inlet duct (18) ) is formed in the fixing flange (13 ') and opens into said upper zone (17'), a second outlet duct (19) is also formed in the flange (13 ') and opens into the chamber (17) between the lid (30 ') and the tray (52).   10. Filtration device according to any one of claims 1 to 9, characterized in that the filter body (10, 10 ') is made of foundry.   11. Internal combustion engine comprising a filtration device according to one of 16 claims 1 to 9, fixed on the engine block by a flange (13, 13 ') ensuring the passage of oil between the engine block and a chamber of the filter body.   12. Internal combustion engine comprising a filtration device according to one of claims 6 or 7, fixed on the engine block by a flange (13, 13 ') ensuring the passage of oil between the engine block and each filter of the filtration device, independently.