WO1999051318A1 - Filter housing with reinforced plastic base - Google Patents

Abstract

The invention concerns a filter housing (1) comprising a base (2) provided with a bottom wall (10) wherein are arranged liquid inlet and outlet and a cap (3) removably fixed with said base defining an internal volume (4) for housing a filtering element (5) inserted between said inlet and outlet. The cap and the base are both made of plastic material. The cap is screwed on the base. A reinforcing metal insert (40) is embedded in the base bottom wall.

Description

 FILTER BOX WITH REINFORCED PLASTIC MATERIAL

The present invention relates to a liquid filter housing for an internal combustion engine, the liquid to be filtered preferably being oil.

Among the filter housings in question, the invention relates more particularly to those comprising:

a base provided with a bottom which comprises a central passage and at least one lateral passage offset with respect to the central duct and parallel to said duct, this central passage and this lateral passage constituting one, an inlet for liquid to be filtered and the other, a liquid outlet, the bottom of the base having an external face which is provided with an annular seal surrounding both the central passage and the lateral passage, the central passage being delimited by an axial tube threaded which is intended to be connected by screwing to a first liquid conduit which communicates with the motor and which is integral with a support surface into which opens a second liquid conduit communicating with the motor, this connection being made by tightening the annular seal at the bottom of the base against the support surface, to make the second liquid conduit communicate with the lateral passage at the bottom of the base, - and a cover fixed to the base by delimiting with it a hollow interior volume which is intended to receive a filter element interposed between the inlet and the outlet of liquid.

In known cases of the type mentioned above, and for example described in patent FR-A-2 184 377, the cover and the base are made of stamped sheet metal, and 2 are fixed to each other definitively by crimping, after insertion of the filter element in the housing.

This type of housing has the drawback of being difficult to recycle. In addition, when the filter element is dirty, it is necessary to change the whole housing when it would suffice to replace only this filter element.

The object of the present invention is to avoid the aforementioned drawbacks. To this end, according to the invention, a filter housing of the kind in question is essentially characterized in that the cover is detachably fixed on the base, the removal of the cover allowing the replacement of the filter element, in that the cover and the base include quick fixing means adapted to allow mounting and dismantling of the cover by rotation of said cover, and in that the cover and the base are made of molded plastic, an annular metal insert reinforcement being embedded in the bottom of the base, this metal insert extending radially outward from an inner edge to an outer edge which is close to the seal at the bottom of the base, the edge interior of the insert being mechanically connected to the axial tube at the bottom of the base so that the insert is biased towards the support surface when said axial tube is connected to the first liquid conduit.

Thanks to these arrangements, a filter housing is obtained, the filter element of which is interchangeable, the cost price of which is low due to the use of plastic material for producing the means for rapid fixing of the cover to the base, and whose base has a 3 good mechanical resistance to pressure, temperature and tightening thanks to the metal insert, the bottom of the base having to withstand a pressure of the order of 15 bars for an oil at 130 ° and 25 bars for an oil at 20 ° C.

In preferred embodiments, use is also made of one and / or the other of the following arrangements:

- The quick fixing means comprise two complementary screw threads respectively provided on the base and the cover so as to screw the cover directly onto the base;

- The inner edge of the metal insert is integral with the axial tube at the bottom of the base;

- The axial tube extends towards the hood and is internally threaded;

- The axial tube extends in the direction opposite to the cover and is externally threaded;

- The axial screwable tube is provided with an enlarged head which abuts against the inner edge of the metal insert, this enlarged head being located towards the inside of the housing relative to the metal insert;

- The metal insert has a convex shape facing the external face of the bottom of the base;

the filter element comprises a frame and a filter wall which is carried by this frame and which has an end provided with a flange, a crown having come integrally with the base of the base, on an internal face opposite to the external face, at a location located between the central passage and the offset passage, to come into tight contact with said flange;

- ribs for centering the frame of the filter element relative to the central passage are 4 integral with the crown and are directed axially inside the crown; and

- an inlet valve is fitted on the crown and is held in place by a peripheral rim made integrally with this crown.

The present invention further relates to a device comprising a housing as defined above, this housing being connected to the support surface with the first and second liquid conduits of the engine, which liquid conduits belong to the oil circuit of the engine.

Other characteristics and advantages of the invention will appear during the following detailed description of three of its embodiments, given by way of nonlimiting example, with reference to the appended drawings, in which: FIG. 1 is a view schematic in axial section of an oil filter housing according to a first embodiment of the invention; - Figure 2 is a side view of the oil filter housing of Figure 1 attached to a support surface of the engine; Figure 3 is a schematic view in axial section of an oil filter housing according to a second embodiment of the invention; and

- Figure 4 is a schematic view in axial section of an oil filter housing according to a third embodiment of the invention.

In the different figures, the same references designate identical or similar elements.

Furthermore, to facilitate understanding of the description which follows, the filter will be described in a 5 particular position, the vertical position, the cover being directed upwards.

However, this position is not limiting, and the filter could possibly be used in another position.

Therefore, terms such as "top", "bottom", "top", "vertical", and "horizontal" are given for illustrative purposes only.

As shown in FIG. 1, the oil filter housing 1 according to the invention consists of a base 2 on which a removable cover 3 is mounted so as to form a hollow interior volume 4 intended to receive a filter element 5.

The base 2 and the removable cover 3 respectively comprise lateral walls, β and 7 which, in the example shown, have a cylindrical shape of revolution around a common axis X-X.

The base 2 extends between a first open end 8 or upper end and a second end 9 or lower end closed by a bottom 10. The base 2 thus has a cross section, in the form of a straight U and is intended to be mounted in a fixed position, for example by screwing directly onto a support surface 14

(Figure 2) of a motor vehicle engine. The removable cover 3 extends between a first open end 11 or lower end and a second end 12 or upper end closed by a curved wall 13. The removable cover 3 thus has a shape, in cross section, of U overturned on the fixed base 2. The cover 3 is immobilized on the base 2 by quick fixing means 15 adapted to allow mounting and dismounting by rotation of the cover 3. In 6 the example shown in the figures, the cover 3 is screwed, by its lower end 11, to the upper end 8 of the side wall 6 of the base 2 by means of two threads lβ formed on each of these extremities. The base 2 and the cover 3 are injection molded from a plastic material, for example polyamide 6-6. Other materials could however be considered without departing from the scope of the invention.

The cover could also be fixed to the side wall of the base by any other means allowing rapid mounting or dismounting of said cover, for example a bayonet mounting, or even mounting via a ring and covering partially the cover and itself screwed or fixed by a bayonet mount to the side wall of the base.

The tightness of the screwing of the cover 3 on the base 2 is ensured by an O-ring 17 carried by the annular wall 7 of the cover 3 and disposed above the threads 16. The opening of the lower end 11 of the removable cover 3 is wide enough to allow the replacement of the filter element 5. This element also has, in the example shown, a cylindrical shape of revolution with a vertical axis XX. It comprises, in a manner known per se, a filtering side wall 18. This is made for example of pleated filter paper and is generally arranged around a rigid frame 19. The frame 19 is itself cylindrical, of axis XX, and delimits a hollow interior space 20 which communicates with the filter paper of the lateral filtering wall 18 by means of several openings 21 formed in the frame 19. The filtering wall 18 also extends 7 between a lower end 34a and an upper end 34b. These ends carry annular flanges 33a and 33b, the plane of which is perpendicular to the axis XX. The frame 17 supports, in a manner known per se, a valve system 50 which extends to the vicinity of the upper end 34b of the filter wall 18, in sealed contact with the flange 33b. This valve makes it possible, when the filter wall 18 is too fouled by impurities, to circulate the oil, between the filter wall 18 and the side wall 7 of the cover 3 so that the oil flows in the frame 20, by passing over the flange 33b of the filtering wall 18.

As shown in the figures, the oil to be filtered arrives in the closed volume 4 by lateral passages 23 offset from the axis XX and formed in the bottom 10 of the base 2, then passes radially through the annular filtering wall 18 of the filter element 5, and finally flows through a central passage 25 also formed in the bottom 10 of the base 2 and axis XX. This central passage is delimited by a threaded axial tube 24 to be screwed to a first conduit 26 of an engine oil circuit. The lateral passages 23 are intended to be connected to a second conduit 27 of said oil circuit. A ring 30 has come in one piece with the bottom 10 of the base 2, on the internal face 31 of this bottom, extending towards the upper end 8 of the base. This ring is located between the central passage 25 and the offset passages 23. The filter element 5 comes into sealed axial abutment against the latter by means of the flange 33a. The crown 30 also has three radial ribs 35 regularly distributed on its inner periphery, in order to center this filter element.

In order to seal the bottom 10 of the base 2 relative to the support surface 14 of the engine on which this base is fixed, an annular groove 36 is formed on the lower face 32 or external face of the bottom 10. This annular groove 36 is located beyond, relative to the axis XX, the position of the offset passages 23 for the oil inlet. An O-ring seal 37 is placed inside this groove 36.

Furthermore, in the bottom 10 of the base 2 is embedded, during the injection, a metal insert 40 intended to reinforce this bottom to resist the incoming and outgoing oil pressures by the offset passages 23 and the central passage 25 .

The metal insert 40 is of annular shape so as to extend over the entire surface of the bottom 10, beyond the location of the annular groove 36. A central recess 41 and offset recesses 42 and 43 are formed respectively opposite the central passage 25 and the offset passages 23 of the bottom 10 of the base 2. The annular shape of the metal insert 40 has an inner peripheral edge 44 and an outer peripheral edge 45. In the first embodiment in Figure 1, the inner peripheral edge 44 is mechanically connected to the central tube 24 of the bottom 10 of the base 2 having come integrally therewith. This tube then extends towards the upper end 8 of the base 2 and is internally threaded so as to be screwed onto the first conduit 26 itself externally threaded. 9

In the second embodiment, the axial tube

24 of the base 2 has an enlarged head 47 which abuts against the internal edge 44 of the insert 40. The tube 24 is then externally threaded so as to cooperate by screwing with the first conduit 26.

In the third embodiment, shown in FIG. 4, the inner peripheral edge 44 of the insert 40 is, as in the first embodiment, formed integrally with the central tube 24 of the bottom 10 of the base 2. This third mode differs from the first in that the tube 24 extends in the direction opposite to the upper end 8 of the base and is externally threaded to be screwed onto the first conduit 26.

In order to further resist the pressure exerted by the oil, the metal insert 40 has a convex shape in the direction of the internal face 31 of the base 2 while the external peripheral edge 45 is bent towards this external face.

A molded inlet valve 51 is fitted onto the crown 30 and is held in place on the internal face 31 of the base 10 by a peripheral rim 52 made integrally with this crown. This valve prevents the return of oil through the inlet passages 27.

The filter housing 1 according to the present invention described above, can be easily immobilized by screwing on the support surface 14 of the engine. The metal insert 40 embedded in the bottom 10 is then biased towards this support surface and allows this bottom to resist the incoming and outgoing oil pressure. In order to replace the filter element 5, it suffices to unscrew the cover 3 from the base 2, the latter remaining fixed to the motor. The used filter element 5 can then be removed and a new element 10 clean filter can be positioned inside the base 2 which is then closed by screwing the cover 3 again.

11 CLAIMS

1. Liquid filter housing for an internal combustion engine comprising: - a base (2) provided with a bottom (10) which comprises a central passage (25) and at least one offset lateral passage (23) relative to the passage central (25) and parallel to said passage (25), this central passage (25) and this lateral passage (23) constituting one, an inlet for liquid to be filtered and the other, a liquid outlet, the bottom (10 ) of the base (2) having an external face (32) which is provided with an annular seal (37) surrounding both the central passage (25) and the lateral passage (23), the central passage (25) being delimited by a threaded axial tube (24) which is intended to be connected by screwing to a first liquid conduit (26) which communicates with the motor and which is integral with a support surface (14) in which opens a second liquid conduit (27) communicating with the motor, this connection being made by tightening the seal annular (37) from the bottom (10) of the base (2) against the support surface (14), to make the second liquid conduit (27) communicate with the lateral passage (23) of the bottom (10) of the '' base (2),

- And a cover (3) fixed to the base (2) defining with it a hollow interior volume (4) which is intended to receive a filter element (5) interposed between the inlet and the outlet of liquid, characterized in that the cover (3) is removably fixed on the base (2), the removal of the cover (3) allowing the replacement of the filter element (5), 12 in that the cover (3) and the base (2) comprise quick fixing means (15) adapted to allow mounting and removal of the cover (3) by rotation of said cover (3), and in that the cover (3) and the base (2) are made of molded plastic, an annular metal reinforcement insert (40) being embedded in the bottom (10) of the base (2), this metal insert (40) extending radially outward from an inner edge (44) to an outer edge (45) which is adjacent to the seal (37) at the bottom (10) of the base (2), the edge interior (44) of the insert (40) being mechanically connected to the axial tube (24) of the bottom (10) of the base (2) so that the insert (40) is biased towards the support surface (14 ) when connecting said axial tube (24) to the first liquid conduit (26).

2. A liquid filter housing according to claim 1, in which the quick fixing means (15) comprise two complementary screw pitches (16) respectively provided on the base (2) and the cover (3) so as to screw the cover (3) directly on the base (2).

3. liquid filter housing according to claim 1 or 2, wherein the inner edge (44) of one metal insert (40) is integral with the axial tube (24) of the bottom (10) of the base (2) . 4. A liquid filter housing according to claim 3, wherein the axial tube (24) extends in the direction of the cover (3) and is internally threaded.

5. A liquid filter housing according to claim 3, in which the axial tube (24) extends in the direction opposite to the cover (3) and is externally threaded.

6. Liquid filter housing according to claim 1 or 2, wherein the screwable axial tube 13

(24) is provided with an enlarged head (47) which abuts against the inner edge (44) of the metal insert (40).

7. Liquid filter housing according to any one of claims 1 to 6, in which the metal insert (40) has a curved shape in the direction opposite to the external face (32) of the bottom (10) of the base. (2).

8. Liquid filter housing according to any one of claims 1 to 7, in which the filter element (5) comprises a frame (19) and a filter wall (18) which is carried by this frame (19) and which has one end (34a) provided with a flange (33a), a crown (30) having come integrally with the bottom (10) of the base (2), on an internal face (31) opposite the face external (32), at a location between the central passage (25) and the offset passage (23), to come into tight contact with said flange (33a).

9. A liquid filter housing according to claim 8, in which centering ribs (35) of the frame (19) of the filter element (5) relative to the central passage (25) have come integrally with the crown (30) and are directed axially inside the crown (30).

10. A liquid filter housing according to claim 8 or 9, in which an inlet valve (51) is fitted on the crown (30) and is held in place by a peripheral rim (52) made integrally with this crown. .

11. A filtration device comprising the housing and the filter element according to any one of the preceding claims, the housing (1) being connected to the support surface (14) with the first (26) and second conduits (27) of engine oil.