FR3078895A1 - REMOVABLE FILTER AND CARTRIDGE, WITH TWO LEVELS OF SEALING IN A WELL BASED ON THE FILTER - Google Patents

Abstract

The combustion engine lubricating liquid filter (1) comprises a housing (2) having in a base (B) an inlet (2a) for raw liquid and an outlet (2b) for purified liquid accessible via a well. A filter insert (4), housed in this casing (2), has a tube integral with at least one structural element of the insert and surrounded by an annular filter medium (5). A purge rod, able to engage axially in the liquid evacuation well, comprises: - a plug forming a first rod-well sealing zone (C1), typically annular, to close off a purge channel; - a section of said tube (7), delimiting a duct communicating with the outlet (2b), the outer face of which has circumferential grooves axially spaced from one another by annular beads which form a second rod-well sealing zone (C2) adjacent to a zone (Z1) of raw liquid.

Description

Filter and removable cartridge, with two sealing levels in a well at the base of the filter

The present invention relates to the purification of liquids and in particular of the oil used in the internal combustion engines of motor vehicles.

The invention relates more specifically to a filter for the purification of a combustion engine liquid, in particular lubricating oil, comprising:

- a housing having in a base (located at the bottom, typically opposite a cover) an inlet for raw liquid and an outlet for purified liquid, the base including an axial duct for access to the outlet and to a channel purge;

a filter insert provided with an annular filter medium internally delimiting a hollow space which opens axially towards the base via an opening at an axial end of the filter insert, and a holding element integral with the filter medium;

- A rod which projects axially outwards with respect to said axial end, the rod comprising a plug intended to close a purge channel.

A filter of this kind is described in the document DE 19859960. The filtration of the liquid, generally of the oil, is carried out in a centripetal way through the annular filtering medium and the purified liquid circulates downwardly around the rod, through the 'hollow space then through the axial duct to reach the outlet via a radial outlet in the axial duct.

The axial duct formed in the base of this type of filter is centered and has a drainage evacuation channel (commonly called a drainage or purge channel, drainage being effected by gravity) which is located lower than the radial outlet towards the outlet of purified liquid.

The upper end of the purge rod is connected to a rigid holding element, formed by an annular flange sealingly covering an axial end of the filter medium or possibly a tubular central support member integrated in the filter insert (and which can be attached to the upper flange and / or the lower flange, this tubular member being able to surround the rod).

In order to seal the axial duct (for the purified liquid) from the peripheral zone external to the axial duct and surrounding the filter insert (peripheral zone for the raw liquid), the filter insert must include a specific annular seal in contact with an external annular zone of the female connector forming the axial conduit.

The purge rod also has an annular seal, which is a labyrinthine seal, that is to say a multi-barrier with successive annular sealing contacts (radial sealing distributed over several annular zones), in order to limit the forces. to be exercised during assembly (compared to solutions with axial sealing), while allowing the assembly / disassembly operations to be repeated with the same sealing separation efficiency.

This filter has certain drawbacks, in particular in the mounting of the bleed rod which requires interposing a spring between a bypass valve and the top of the rod. This spring helps to urge the stem plug in its closed position of the purge channel.

It is understood that the filter described in document DE 19859960 leaves little flexibility for the production of the filter insert and / or for the integration of a bypass valve.

If the filter insert is symmetrical (to avoid any confusion when assembling the rod), it should be noted that the same type of seal must be used at the opposite ends of the filter insert. In practice, this requires aligning with the most expensive joint (which is typically the bottom joint surrounding the female connector, knowing that the female connector on the base is typically metallic).

Furthermore, it may be useful to be able to extract a cartridge formed by the filter insert assembly and the purge rod, then selectively change the filter insert by reusing the purge rod.

More generally, it would be advantageous to limit the cost of production of the filter insert.

There is therefore a need for an alternative solution for assembling a cartridge with filter insert and purge rod in a corresponding housing and which overcomes one or more of the aforementioned drawbacks, while making it possible to effectively obtain the sealing functions, with little difficulty in handling for the user.

To this end, a filter of the aforementioned type is proposed according to the invention, comprising a tube integral with the holding element, the rod comprising a male connector constituted at least in part by a section of the tube for engaging tightly in the axial duct of a female connector of the base and delimit an intermediate channel between the interior space and the outlet, in a state of final coupling of the tube in the axial duct, the section having sealing elements determined distributed on its lateral external face, knowing that in the final state of coupling, it is obtained:

- by the plug, a first female connector-sealing zone for closing the purge channel (also called drainage channel);

- By at least one of the determined sealing elements, a second female connector-sealing zone separating the axial duct from a peripheral zone surrounding the female connector and in communication with the raw liquid inlet.

Thanks to this rod arrangement to form both an intermediate channel (in the central position) for evacuation towards the outlet and a male connector around this intermediate channel, it is possible to make the desired seals with respect to the area upstream of filtration, compatible with a simple design of the filter insert.

In addition, it is permissible to make the seal under the interior space by an external annular surface directly formed on the rod, typically on the section delimiting the intermediate channel. The rod thus closes the axial opening forming the lower outlet of the filter insert.

The tube can also form a barrier for retaining purified liquid, so that the interior space delimited by the filtering medium does not empty of the liquid.

A one-piece realization of the tube is allowed, which limits the number of pieces to form the cartridge resulting from the assembly of the rod with the filter insert.

According to one feature, the determined sealing elements preferably produced in a single piece with the section, comprise an annular sealing surface defining an annular sealing contact, preferably a radial annular contact, with the internal face of a portion tubular belonging to a lower flange (typically plastic flange) provided in the axial end of the filter insert. This makes it possible to separate the interior space in a leaktight manner from the peripheral zone, once the rod has been assembled with the filter insert. This design is compatible with a simple structure of the lower flange, for example without a technical seal to be interposed between the filter insert and the rod.

The attachment of the rod to the filter insert can be rigid, typically without axial play or with very little axial play (much less than 1 mm).

A filter media holding element may consist of the lower flange, made of rigid plastic (preferably made in one piece). This lower flange includes a radial portion tightly attached to the lower axial end of the filtering medium and has stop means for limiting or preventing the relative axial displacement of the rod (or at least of the rod part, typically the tube, directly connected to the lower flange) relative to the filter insert.

It is understood that the rod tube can alone form the interface for fixing the rod to the filter insert, for example by connecting to at least one holding element integrated into the filter insert during its design. Typically, two opposite flanges, preferably of rigid plastic, can form the holding means to which the tube is connected.

According to one feature, the male connector has an external face which has circumferential grooves axially spaced apart by a plurality of annular beads formed integrally with the section of the tube, so as to form a labyrinthine seal which includes these annular beads and which produces the second sealing zone by a plurality of annular radial contacts against an internal face, for example substantially cylindrical, of the female connector.

The expression “labyrinth seal”, in the context of a seal made against one face of an axial duct, is to be interpreted in the same way as in document DE 19859960 (whose publication dates from the year 2000). Such a joint has a multi-barrier effect due to the presence of at least three annular beads (delimiting at least two circumferential grooves whose geometry and dimensions can be identical or similar

In an alternative embodiment, the determined sealing elements comprise or are produced in the form of two annular seals, at least one of which is designed separately from the tube

According to a preferred option, the filter insert extends longitudinally between a first flask distal to the outlet and a second flask proximal to the outlet, the second flask (lower flask) being able to delimit by a border the opening which is crossed by the tube.

The labyrinth seal may have a first annular end, adjacent to one of the circumferential grooves, which includes an annular surface in radial sealed contact against the edge.

If necessary, the tube attached to at least one of the flasgues can participate in a retaining function of a sealing element, this sealing element sealing with a bypass valve which is typically placed between the cover. and the filter insert.

According to another particularity, there is provided a bypass valve which has an insertable part through a central passage of the upper end of the filter insert.

This arrangement makes it possible to limit the additional overall dimensions of the bypass valve relative to the filter insert.

Preferably, the female connector forms a fixed element for centering the cartridge formed by the filter insert and the rod, before any contact of the filter insert against the female connector (this allows guiding of the rotational movement if the cover becomes fixed by screwing, avoiding to off-center the cartridge, in particular at the beginning of the screwing of the cover).

In various embodiments of the filter according to the invention, it is possible optionally to have recourse to one and / or the other of the following arrangements:

- The labyrinthine seal, preferably made from a single plastic material, comprises a maximum external diameter in a configuration at rest, the maximum diameter being formed by the annular surface of a bead determined from among the annular beads and between 101 % and 110% of an external diameter of the other beads the bead formed by the determined extends outside the axial duct female connector, preferably to engage by an annular sealing contact against a lower flange of the insert filter, while the other beads, at least three in number, preferably at least five in number, are in radial annular contact against an internal face of the female connector.

the rod and the filter insert are part of a removable cartridge adapted to release the purge channel during the extraction of the cartridge from the interior volume.

- The cartridge has a lateral periphery directly delimited by the external face of the filtering medium.

- an upper flange of the filter insert (in contact with the upper axial end of the filter medium) forms the upper end of the cartridge, possibly by supporting a bypass valve.

- The rod is obtained by fixing a closure element including the plug at a lower end of the tube, preferably by engagement of elastically deformable tabs against at least one grip edge.

- the closure element and the tube are made to slide together (when the rod slides in the female connector), in an assembled state of the removable cartridge.

- the tube is made of a single plastic part. Optionally, the tube is snapped on, for example by elastic fitting, against a rigid internal face of the filter insert (internal face which can be formed by holding means such as two opposite flanges).

- the section of the tube is an intermediate portion of the tube, which extends between:

- a lower end portion of the tube opening into the axial duct and making it possible to connect a rod end, designed separately from the tube and which includes the plug;

and

- an upper end portion of the tube surrounded by the filtering medium and preferably provided with radial openings.

- The lower flange has a radial portion of annular shape which can axially abut against a free edge of the female connector.

- The axial duct extends entirely under the interior space delimited by the internal face of the filtering medium.

- The lower flange, preferably made of a plastic part, includes complementary securing means of an axial retaining groove formed externally on the section of the tube.

the lower flange is made in at least two pieces; in this

One of the pieces forming the fixing flange can be wider to define the axial covering function of the filtering medium, while another piece can be narrower by presenting a surface in contact with the tube and / or the female connector , at least in the mounted / operational configuration of the filter insert.

the housing has a bowl made of a block, preferably of metallic material, having a mounting support provided with the female connector, the female connector preferably being central and projecting longitudinally in the upper opening direction of the housing has a bottom with a purge channel separate from the inlet and the outlet and situated lower than the outlet, the tube supporting a obturation element forming or extending downwards a projecting part of the rod, the plug belonging to the obturation element to seal at least one opening of the purge channel (the drainage can result from the simple effect of gravity when the cartridge the cover, which forms a closing part of the housing making it possible to close

The upper opening of the bowl is adapted to be screwed onto the bowl, preferably having an insertable part (in the bowl) provided with an external thread.

According to one feature, the section of the tube can form a barrier adapted to retain purified liquid in the interior space, at least in an annular space delimited between an internal face of the filtering medium and the tube. Such an annular space (subspace of the interior space of the filter insert) typically extends above a lower flange of the filter insert.

With such a section, typically devoid of radial openings, it is permitted to retain liquid in the interior space (the liquid does not escape to the oil pan), keeping it at a sufficient level even at engine shutdown, for example reaching at least half the height of the filter medium. This allows the engine to be lubricated more quickly (no need, for example, to refuel the line) and can prevent the engine from running on restarting without sufficient oil pressure.

According to another particular feature, the tube comprises an external cylindrical face on which external reliefs protrude to maintain a radial spacing between an internal face of the filtering medium and the external cylindrical face.

face

According to an option, the internal which a first cylindrical presents:

connector diameter

Dl in which is engaged a lower end of a second cylindrical diameter D2 where is engaged an upper end of a third cylindrical diameter D3 on which s three of the labyrinthine beads, a the female comprises a first section in radial contact plug, in a second in radial plug contact, in an engaging and third at least annular of the watertight section watertight section section two or seal purge orifice, located second section, orifice belonging between the first at the outlet, section and preferably located in a zone of variation of section between the second section and

The female connector on the same central axis, and satisfied:

Optionally, the and the

Dl <

D2 third section.

the tube relation an element extend around following can 'obturation distinct from the tube being (typically of less radial obstruction forms the following first

D2 <D3 / 2 and second diameters is satisfied and

Furthermore, the invention also has for the object relationship a cartridge combining the functions of liquid filtration in order to separate the impurities (in particular solid) in a lubrication liquid, for closing a purge channel adapted to cooperate in a filter according to the invention knowing that this removable cartridge is defined by the filtering insert which is disposable and by the rod which can be chosen or not to be reused (partial re-use of the rod being also permitted if necessary, for example reusing only the end with the cap

The removable cartridge, able to cooperate in the interior volume of the filter housing according to

1'invention, being able to separate the impurities in a lubricating liquid, is provided with a sealing element which is connected to the filter insert by the tube, the tube and the sealing element defining the rod which s 'extends through an annular flange forming the lower axial end of the filter insert, knowing that the determined sealing elements, preferably in the form of a labyrinth seal, are made in one piece on which fixes the sealing element, the male connector extending axially:

- from a sealing zone resulting from a radial annular contact between the rod and the annular flange,

- Up to the plug of the sealing element which has a narrower radial size than the determined sealing elements.

According to one feature, the determined sealing elements comprise an annular sealing surface defining an annular sealing contact, preferably a radial annular contact, with the internal face of a tubular portion belonging to the annular flange forming the axial end. bottom of the filter insert.

Optionally, the specified sealing elements are included in a labyrinth seal (also called a labyrinth seal). Typically, this labyrinthine seal extends axially closer to the annular flange than to the plug and / or has circumferential grooves axially spaced apart by a plurality of annular beads belonging to the labyrinthine seal.

Optionally, the determined sealing elements comprise at least three annular beads, preferably at least five annular beads.

At least one of the circumferential grooves formed between two successive annular beads may be axially narrower in at least two zones of the groove which are diametrically opposite, due to a local allowance in said two successive beads. This design can limit the axial extension of each bead, as regards more than half of its circumference, which makes it possible to limit the stresses and the force to be applied during assembly of the cartridge (screwing and unscrewing can be more easy) while ensuring a good seal between the clean liquid zone and the unfiltered raw liquid zone.

According to one feature, the filter insert includes an additional flange called upper opposite the lower annular flange forming the lower axial end of the filter insert.

Optionally, the lower annular flange is provided with an opening centered on a central axis, for the passage of the tube and of the purified liquid coming from the interior space delimited by the filtering medium.

For example, at least one, and preferably each, of the two annular flanges has:

- A tubular portion having an internal face provided with one or more protrusions inwards;

- A substantially planar and sealed radial portion, extending around an opening and on which is fixed an annular axial end of the filtering medium.

Preferably, the tube has an external face on which projections project radially outward, delimiting between them at least one annular retaining groove, the upper flange and / or the lower flange being integral with the sliding tube, according to the direction of the central axis. Typically, this joining is allowed by the inwardly projecting reliefs and an axial abutment edge distinct from the projecting reliefs, as regards the tubular portion of at least one of the two annular flanges.

When the tubular portion is engaged in the groove of the tube, it is understood that the flange and the rod remain integral with each other in axial sliding.

According to one feature, the tubular portion of the lower flange projects axially upwards from the radial portion of this flange, the tubular portion comprising on an internal face of the lugs (or similar projecting reliefs) protruding radially inwards relative to the rest of the inner face of the tubular portion.

Other characteristics and advantages of the invention will appear during the following description of several of its embodiments, given by way of nonlimiting examples, with reference to the accompanying drawings in which FIG. 1 is an exploded view of a filter according to the invention, illustrating the filter cartridge and the associated housing;

tube Figure 2 is forming a seal a perspective view showing a labyrinthine and can engage in the hollow interior space of the filter insert;

- Figure 3 is a longitudinal sectional view showing the mounting of the cartridge in the bottom part of the housing, according to the same embodiment as the figure;

- Figure 4 is a perspective view of the part of the tube intended to engage in the axial duct of the base forming the mounting support;

- Figure 5 is a detail of Figure 3 illustrating a sealing interface between the clean side and the dirty side;

- Figure 6 is a longitudinal sectional view illustrating the lower part of the removable cartridge in a state of final coupling of the rod in the female connector of the base of the housing;

- Figure 7 is a longitudinal sectional view showing the upper part of the removable cartridge in an assembled state, with an attachment of the cartridge to the cover via a bypass valve;

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

With reference to FIGS. 1 and 3, the fluid filter 1 comprises a box which includes a bowl 2, with a bottom or base part B, and a cover 3 which is detachably fixed to the bowl 2, for example by screwing. The general shape of the bowl 2 makes it possible to define, with the cover 3, an interior volume V of the housing 2.

The base B can include a mounting support intended to remain integral with the engine, in a motor vehicle. More generally, it is preferred that the base B or the bowl as a whole constitute a fixed part of the housing 2, while the cover 3 is separable by means of a removable fixing defined at the periphery of the interior volume V. The cover 3 is preferably made of plastics material, while the bottom portion or base B can consist, wholly or essentially, of a metallographic material, for example aluminum or an aluminum alloy. The bowl 2 as a whole may be metallic.

The cover 3 has for example a threaded area 3a formed on the external face of a tubular portion of the cover 3. This threaded area 3a typically cooperates with a complementary threaded area 2c provided on a side wall 24 of the bowl B, here on one side internal of the side wall 24. An annular seal J1 can be added and placed in axial abutment against a flange or housed in an annular groove, here formed on the cover 3 in the nonlimiting example of FIG. 1. The upper part of the cover 3 may have one or more projecting members. Here, there is provided a maneuvering relief facilitating the grip by a disassembly tool.

As clearly visible in FIG. 3, the filter 1 has, in an operational state, a longitudinal axis called in the following central axis A. A disposable filter insert 4, capable of filtering a lubrication liquid (thermal combustion engine oil for example), extends around this axis A. As can be seen in FIG. 1, the filter insert 4 is housed in an interior volume of the housing (2, 3). The filter insert 4 has a first end 4a, here upper, provided for example with a first flange 8, called upper flange.

The upper flange 8 optionally allows the mounting of a bypass valve 30 which can be detached from the cover 3 and / or the filter insert 4. Lugs 4p can detachably hold such a valve 30. According to one option, the valve 30 can be rotatably mounted and locked on the upper flange 8 by the engagement of an annular portion in the legs 4p.

A movable valve 12 of the valve 30, visible in FIG. 7, can rest on an axial seat area formed in the interior space 6 and surrounded by the tube 7 of the rod T. A spring or elastic return element similar requests the valve 12 to a high sealing position against the seat area, here annular.

The filter insert 4 has a second end

4b, here lower, provided with a second flange called in the following lower flange 9.

An annular filter medium 5 extends between the two ends

4a,

4b, and more particularly between these around the central axis A. The filtering medium 5 makes it possible to filter the liquid, typically a lubricating oil.

According to one option, the filtering medium may have cellulose fibers and / or polyethylene fibers (with a mixed technology associating at least two types of fibers, the particles greater than microns can be typically stopped).

Each of the can be made of a plastic material.

It may be advantageous if the

The filter insert 4 can be mounted in either direction (along the axis A). For example, when provision is made for attachment reliefs of a bypass valve 30 example in the form of legs

4p elastically deformable (here with elastic return effect radially inwards in the example of FIG. 3), each of the flanges

Respective peripheral annular portions of the flanges which extend the radial portions axially

9r, are optionally provided in order to cover the ends of the external lateral face 5b with the filtering medium

The filter insert 4 can be simple to assemble.

It includes for example the annular filter medium 5 and only one or two flanges 8, 9 (each forming a rigid holding element) supporting the filter medium at one of its axial ends 5c, 5d. As illustrated in FIGS. 3 and 7, the filter medium 5 of the filter insert 4 has an external face 5a on the side of a peripheral zone in communication with the inlet 2a, as well as an internal face 5b internally delimiting a space hollow which opens axially towards the base

B via a lower opening at an axial end 4b of the filter insert 4.

Typically two opposite axial openings are provided central

The insert in the filter insert 4 each in an area of the corresponding end 4a, 4b. When filter 4 has two flanges openings can be of size

The upper opening can serve as the bypass valve 30 being identical or as access for partially the interior space 6. The lower opening 04 for communicating axial duct 21 provided for forming a similar plug.

bypass, housed in allows the interior space in the female base of with a connection through which can be inserted (by allowing to close the channel of

The filter insert 4 can have an annular cover at the bottom) a purge 2d.

be supported rod T by the (here via the valve 30 engaged against the reliefs and commits to sealing delimits an area against the base so that

Zl upstream

B by forming a zone that the filtering insert of the filtration in communication with the inlet 2a for raw liquid and zone Z2 downstream of the filtration at the outlet 2b can preferably see a communication with the filtered / purified liquid. In Figure 1, 'input 2a' opposite the

Input 2a and axially lower

In the figure, it is shown that the and the outlet 2b are formed cover 3, in the

2b can thus be lower flange 9.

1, we can see that the basic B basic

B.

offset has a female connector CF which leads axially 21 to access purge channel 2d. In central A forms an axis of at once delimits the symmetry at the top of the axial duct 21. The internally an outlet 2b and in a nonlimiting, the minus axis for the axial duct part 21 is in the form of a well of base B, which opens at its lower end towards a zone for collecting the purged liquid via the purge channel 2d.

The rod T for purging and its attachment to the filter insert 4 will now be more particularly described.

The rod T projects axially outward relative to the lower axial end 4b, and has a portion inserted into the opening 04 to allow:

- to connect the rod T to the filter insert 4, in a sliding manner along the axis A;

- Separately sealing the interior space 6 where the clean liquid circulates and the zone ZI which extends around the filter insert 4 and around the female connector CF.

The rod T has a tube 7 including the portion inserted into the filter insert 4 and further forming a labyrinth seal 14 which is, totally or partially, located in a projecting part, axially projecting downward relative to the insert. filter 4.

At the lower end of the rod T, below the labyrinth seal 14, there is a plug 10 intended to close the purge channel 2d. The plug 10 has one or more annular sealing surfaces for producing one or more sealing contacts Cl, Cl 'which prevent the purified liquid from reaching a bottom region of the axial duct 21. Optionally the plug 10 may have two seals J2 , J2 '(as visible in FIG. 6) axially spaced apart from each other and / or have a labyrinth seal separate from the labyrinth seal 14.

In a manner known per se, the length of the projecting part of the rod T is such that, in the mounted state in the housing (2, 3) of a cartridge CA including the filter insert 4 and the rod T, the plug 10 either in the shutter configuration of the purge channel 2d. The CA cartridge, which is removable, is designed and arranged to release the purge channel 2d during the extraction of the CA cartridge from the interior volume V. The assembly formed by the filter insert 4 and the rod T (and also the bypass valve 30 in certain variants) defines a removable cartridge CA, adapted to be mounted in and extracted from the interior volume V by means of the connection of the cartridge CA, direct or indirect, with the cover 3.

In the assembled state of the cartridge CA, it is further provided that the labyrinthine seal 14 is engaged in the female connector CF. In other words, the rod T has a male connector CM constituted at least in part by a section 7c of the tube 7 to engage in leaktight manner in the axial duct 21 of the female connector CF. The section 7c can delimit an intermediate channel 70 which extends between the interior space 6 and the outlet 2b, possibly at an axial distance from the plug 10.

As illustrated in FIGS. 2 and 4, the labyrinthine seal 14 is included in the section 7c, so that the annular external face of the section 7c has circumferential grooves G axially spaced apart by a plurality of annular beads 14a, 14b, 14c made in one piece with the section 7c of the tube 7.

The male connector CM thus has a multi-barrier effect to prevent raw liquid from the zone Z1 from entering the axial duct 21. In FIG. 3, it can be seen that the section 7c delimits an intermediate channel 70 between the interior space 6 and the outlet 2b in the final state of coupling of the tube 7 in the axial duct 21.

The tube 7 is preferably a hollow plastic tube extending longitudinally, around the axis A, between a lower end 7a and an upper end 7b. The tube 7 can help to stiffen the filter insert 4, by being in annular radial contact from the inside against a holding element belonging to the filter insert 4, typically against the upper flange 8 and against the lower flange 9 in preferred embodiments.

The tube 7 has a grid-like structure at least in a portion adjacent to its upper end 7b. This upper end 7b delimits a central opening 01 through which the optional bypass valve 30 can pass.

The section 7c can be an intermediate portion of the tube 7, preferably devoid of radial openings, which extends between:

- A lower end portion of the tube opening into the axial duct 21 and making it possible to connect one end of the rod which includes the plug 10; and

- An upper end portion of the tube surrounded by the filter medium 5 and preferably provided with radial openings 28 (the structure of this upper end portion being a grid in the examples shown).

Referring to Figures 1, 3 and 6, the rod T may have a closure element 19 to form a rod end designed separately from the tube 7. In an alternative embodiment, the rod end can be formed directly by the tube 7, the joint or joints J2, J2 ′ of the plug 10 being for example angularly attached to this end.

Referring to Figures 1, 3 and 6, the closure element 19 includes the plug 10 under a flange C which can be supported on an annular seat which surrounds the outlet of a narrow sub-duct 21 'of the axial duct 21. The female connector CF preferably projects towards the cover 3, through a part that is wider than the narrow sub-duct 21 '.

The closure element 19 has, in the nonlimiting example illustrated, a maximum radial size less than an external diameter D14 of the labyrinth seal

14. Here, the shutter element 19 is connected to the filter insert 4 by the tube 7. The shutter element 19 forms the lowest part of the rod T, axially distant from the lower flange 9.

With reference to FIGS. 1, 3 and 7, the tube 7 extends through the annular flange 9. The labyrinthine seal 14 can be made in one piece on which the closure element 19 is fixed. Preferably, the tube 7 is made of a single piece of plastic, including the labyrinthine seal 14. The tube 7 is snapped into the interior space 6, preferably with a fixing both on the upper flange 8 and on the lower flange 9.

In the option illustrated, the lower end 7a of the tube 7 has a central opening 02 for the passage of purified liquid and has one or more grip edges 71, around this opening 02, on which hooking tabs 19c or similar reliefs belonging to the shutter element 19 are supported. Referring to Figures 5 and 6, the closure element 19 has an openwork section 15, here formed by four branches which converge towards a junction portion of the plug 10, for example on top of one end of the plug where is formed the flange C.

The hooking lugs 19c are formed in a ring 19b and are elastically deformable, so as to deviate radially inwards, which makes it possible to insert the ring 19b in the intermediate channel 70. When mounting the element d shutter 19 on the tube 7, the ring 19b is pushed axially into the opening 02 until the radially projecting part of the latching tabs 19c crosses the lower end 7a and is located opposite recesses or slots 07. With an elastic return effect, the tabs 19c engage radially in the slots 07 and are positioned in abutment axially (above) against the grip edges 71. With this arrangement, the product rise when unscrewing the cover 3 also leads to shutter 19.

More generally, we

The filter insert 4 which, or similar disassembly of the ascent of the element, comprises that the closure element 19 can be removably attached to the tube 7, for example by snap-fastening, and preferably at the lower end 7a without the internal passage section defined in the junction zone (between the closure element 19 and the tube 7) being too reduced. Typically, the fixing is carried out so that the internal diameter of this passage section remains greater than an internal diameter of the narrow sub-duct 21 'closed by the plug 10.

In the example shown in FIGS. 1 to 3, the tube 7 may have a tubular barrier portion 17 (without radial opening) to allow a retention of liquid having just been filtered in a lower part of the interior space 6.

This tubular barrier portion 17 in fact prevents a large part of the liquid which has just been filtered from being poured into the axial duct 21.

When the engine fitted with filter 1 is switched off, at least half of the purified liquid from zone Z2 can remain in this zone Z2 of the interior volume V.

As clearly visible in FIG. 2, the tube 7 may have an external cylindrical face 18 on which external reliefs RI, R2 project to maintain a radial spacing between the internal face 5b of the filter medium and the cylindrical face is for example provided two longitudinal ribs RI, the length of which is substantially identical to the height of the filter medium and which are diametrically opposite.

Alternatively or several ribs in addition, one can be provided with one or longitudinal ones distributed regularly over the periphery of the external cylindrical face 18. The reliefs R2 can be spaced from one another, optionally having an extension perpendicular to the ribs RI. In a variant, it is possible to provide at least one helical rib to allow the spacing with respect to the internal face 5b. Here, the external face 18 is formed by the tubular barrier portion 17 and by the grid portion 7h which is an axial extension of the tubular barrier portion 17.

The tube 7 can contribute to supporting the internal face 5a (here defined by filtering material of the filtering medium

5), in order to prevent excessive deformation of the filtering medium 5 under the pressure of the fluid passing through the filtering material centripetally. The openings 28 in the support tube 7 allow unrestricted penetration of the liquid inside this tube 7.

The support tube 7 can in particular be screwed or clipped directly onto the lower flange 9, for example in a fixing zone located in the interior space 6, above a radial sealing zone between the filter insert 4 and an annular projection or bead 14a of the tube 7. The tube 7 can also be screwed, clipped, or otherwise made integral with the upper flange 8.

The tube 7 and the filter insert 4 can be preassembled, for example before mounting the closure element 19 on the lower end 7a. In the case of a CA cartridge, this can make it possible to minimize the overall length and size of the associated packaging. Typically, the enclosing of the closure element 19 is a very easy operation, preferably achievable with less effort than an interlocking of the tube 7 in the interior space 6.

For pre-assembly with the filter insert 4, the tube 7 can be inserted through the opening 04 and fixed to at least one of the flanges 8, 9. In the nonlimiting example of the drawings, each of the two annular flasgues present:

a substantially flat radial portion 8r or 9r, extending around an opening, and on which is fixed in sealing manner an annular axial end 5c or 5d of the filtering medium 5; and two a portion provided with a

As visible tubular PT or or on several the figure having an internal face projecting reliefs towards

2, when it is fixed to the tube 7 has on its external face two axially spaced zones, on each of which projections 14a, 27, 37a, 37b project radially outwards

Thus the projections 27 and 37b, here of annular shape and formed at the upper end 7b, delimit between them an annular retaining groove GH, also called high groove to receive one or more of the latching reliefs of the

Similarly, the projections

14a and 37a, here of annular shape and placed near the labyrinthine seal 14, delimit between them an annular retaining groove GB, also called low groove to receive one or more snap-fit reliefs of the lower flange 9.

Of course, this provision may relate to only one flange in an alternative option. Furthermore, the labyrinth seal 14 may be further down than the lower flange in an alternative embodiment, or a

Conversely it can be placed at least partly in

The interior space by providing, below, a low annular groove GB or other similar attachment zone of the flange

Thanks to the engagement of each in the corresponding groove

GH

GB the tube 7 is made integral with the sliding filter insert, in the direction of the central axis A.

The salient reliefs 8th,

9e, which are for example in the form of lugs projecting radially inwards to penetrate the corresponding groove GH, GB, are associated with an axial abutment edge 8f, 9f belonging to the tubular portion PT of the flange concerned 8 , 9.

For example, with regard to the lower flange 9, the reliefs or lugs 9e and the upper abutment edge 9f of the tubular portion PT are engaged in the retaining groove GB, so as to make the lower flange 9 integral in sliding of tube 7.

In one embodiment, as visible for example in FIG. 5, the lower flange 9 has at least two longitudinal recesses 7d which are preferably two slots, each of these longitudinal recesses 7d having a lower edge adjacent to a lug 9e or relief similar among the respective projecting reliefs which are spaced apart on the inner circumference of the lower flange 9. The recesses 7d can make the plastic deformation of the tubular portion PT easier, which facilitates the pre-assembly operation of the tube 7 and limits the risk of deterioration during the insertion of the tube 7 into the filter insert 4 (even if the latter is symmetrical or without significant difference between its flanges 8, 9).

According to an option, the projection 37a is here axially offset upwards relative to the labyrinth seal 14, so as to be located between the male connector CM and an upper end 7b of the tube 7. FIGS. 1 and 2 illustrate this relative position for forming an attachment zone at an axial distance from the grid portion 7h and at an axial distance from the lower end 7a.

The position of the projection 37a is here higher than the pins or similar reliefs 9e to engage axially (downwards) against the upper stop edge 9f. It is understood that the projection 37a, optionally annular, can delimit continuously or possibly discontinuously the top of the retaining groove GB.

Referring to Figure 2, there is provided a first annular projection 14a of the labyrinthine seal 14 which can delimit the bottom of the retaining groove GB, forming an annular abutment surface on which the pins or similar reliefs 9e can engage axially (down). More generally, and as can be seen in the nonlimiting example of FIG. 3, the labyrinthine seal 14 can be used for sealingly separating the zones ZI and Z2, by performing both:

- a contact radial annular C2 (contact radial towards 1 'outside) against the female connector CF through a first part of labyrinth seal 14, and - a contact radial annular C3 (contact radial towards 1 'outside) against the lower flange 9 through a second part of this same labyrinthine seal 14.

Thanks to the snap-fitting between the tube 7 and the lower flange 9, here produced as close as possible to the contact C3, the stresses are limited in the sealing zones (for example caused by vibrations during the operation of the vehicle carrying the filter 1 ) which are exerted on the rod T. In fact, these zones with sealing contacts C2, C3 are located in the zone of contact between the male connector CM and the female connector CF, with a protective / holding effect played by the CF female connector which is typically made of a more rigid material than the plastic material of the tube 7.

Referring to Figure 1, the cartridge CA can be removed with the cover 3, disengaging from the female connector CF. The fixing interfaces, in particular those produced in the two flanges 8, 9 allow the cover 3 to raise the cartridge CA, knowing that at least the lower flange 9 is integral with the tube 7, at least by an axial contact of the abutment edges upper 9f against the underside of projection 37a.

When mounting the cartridge CA (when screwing or similar mounting of the cover 3), it is optionally the lugs 8e, 9e which bear against a lower edge of the grooves GH, GB. For example, lugs 9e of the lower flange 9 can engage on top of the first annular projection 14a.

More generally, it is understood that each of the two flanges 8, 9 can be engaged in a corresponding groove formed by the tube 7, so that each of the flanges is integral in sliding with the tube 7.

During the operation of the filter 1, the liquid to be filtered arrives through the inlet 2a and can circulate along a side wall of the bowl 2, before passing through the filter medium 5 centripetally. In the interior space 6, the filtered liquid is discharged through the central conduit 21 which forms, for example, the only access to the outlet 2b in the assembled state of the cartridge CA.

When the tubular barrier portion 17 is provided, an upward circulation movement is made so that the purified liquid reaches the openings 28 of the grid portion 7h and then flows downwardly inside the tube 7 and into the intermediate channel 70, up to opening out of the tube 7, into a chamber 22 internal to the female connector CF, visible in FIG. 3. The chamber 22 constitutes a sub-part of the axial duct 21, between the connection area of the rod-female connector and the narrow sub-duct 21 '.

The outlet 2b can be connected radially to the chamber 22 where the purified liquid arrives. As clearly visible in FIG. 6, in the final coupling state, the purified liquid cannot go lower thanks to the plug 10.

In a nonlimiting example, as illustrated in FIG. 3, the female connector CF can have an internal face which has:

a first diameter DI in a first cylindrical section (for a sealing zone Cl ′ female connector rod) where a lower end of the plug 10 is engaged in sealed radial contact,

a second diameter D2 in a second cylindrical section (higher than the first section, immediately under the chamber 22) where is engaged in sealed radial contact C1 an upper end of the plug 10, and

- A third diameter D3 in a third cylindrical section (higher than the second section, where the upper opening 21a is provided) on which engage at least three of the annular beads 14b, 14c of the labyrinth seal 14 to form another zone seal C2 rod - female connector.

The axial extension of the first section DI may be shorter than the axial extension of the third section. Furthermore, the female connector CF may also include, in its internal face, a drain orifice situated between the first section and the second section. Another orifice belonging to the outlet 2b can be located in the chamber 22 (higher than the purge orifice) or in a zone of variation of similar section, between the second section and the third section.

Optionally, the following relation is satisfied: DI <D2 <D3.

The diameter DI and / or the diameter D2 is preferably less than or equal to half of the diameter D3. This makes it possible to miniaturize the plug 10 and thus avoid increasing the size of the base B.

More generally, it is understood that, in the final state of coupling, it is obtained:

- By the plug 10, at least a first rod-connector sealing region female Cl, Cl 'to close the purge channel 2d; and

- By the labyrinthine seal 14 including the annular beads 14a, 14b, 14c, a second sealing region of the female connector-stem C2 separating the axial duct 21 from the zone ZI.

With reference to FIGS. 3 and 7, the zone Z2 where the purified liquid circulates can be partly internal to the tube 7. By the part of the zone Z2 external to the tube 7, it is possible to keep a high level of purified liquid when stopped. of the engine, in particular when this tube 7 has radial access openings 28 only near its upper end 7b.

The labyrinthine seal 14 of the rod T can be dimensioned to limit the efforts to be provided. In the example shown in FIG. 4, several intermediate beads 14b, optionally thinner than the end beads 14a, 14c, are provided to form a sealed radial contact against the internal face of the female connector CF, here in the cylindrical section where is formed the upper opening 21a for access to the conduit 21 (third section of diameter D3 in the nonlimiting example illustrated).

The bead 14c closest to the lower end 7a, may have an external dimension smaller than the external dimension of the bead 14a most distant from the lower end 7a (the latter bead 14a being designed to be engaged against the lower flange 9 , preferably remaining outside the axial duct 21). In the option illustrated, the section 7c of the tube 7 where the labyrinth seal is designed 14 can have:

a maximum external dimension (here a maximum diameter), greater than the diameter D3 of the upper opening 21a, provided in an upper bead 14a which delimits the top of an upper circumferential groove among the annular grooves G of the labyrinth seal 14, and an outer diameter

D14 or similar characteristic external dimension, in a resting configuration, mistletoe is identical or substantially the same for the other beads 14b, 14c intended to engage by radial contact against an internal face of the female connector, this diameter D14 being greater than the diameter D3 provided for the upper opening 21a or close to it.

can

The external diameter is optionally

D14 characteristic of the seal formed by the annular surface of the intermediate annular flanges 14b and of the lower flange 14c of the seal 14, which delimit between them at least two or three circumferential grooves G. The dimension of the upper flange 14a, here a diameter, is for example between 101% and 110% of the external diameter D14 (diameter of the other beads 14b, 14c).

The minimum distance dl between two successive beads of the labyrinth seal 14 may be greater than the axial dimension of any of the intermediate beads 14b. This facilitates the elastic deformation of the beads 14b, 14c engaged against the female connector CF and optionally of the bead 14a selectively engaged against the filter insert 4 (typically via the lower flange 9).

In a preferred embodiment, at least one of the circumferential grooves G formed between two successive annular beads 14a, 14b, 14c is axially narrower in at least two zones of the groove which are diametrically opposite. The minimum distance dl can thus be measured in two diametrically opposite zones of the labyrinth seal 14, while gu'a maximum distance d2 (also measured axially, in the direction of the axis A) between two successive annular beads 14a, 14b, 14c can also be defined in two other complementary zones, distant from the two throat narrowing. The narrowing of the annular grooves

G here results from a local excess thickness in the intermediate beads 14b, so that between two successive beads the extension of the groove G varies (non-constant extension in the axial direction of

It should be obvious to those skilled in the art that the present invention allows embodiments in many other specific forms without departing from the scope of

1 invention as claimed.

Thus, although the internal face of the axial duct 21 in contact with the labyrinth seal 14 (in the state of may be substantially cylindrical over the entire length of the labyrinth seal 14 in a preferred option, it is of course possible to provide for slight changes in the section of the axial duct 21 or even at least one shoulder, as required, provided of course that the section variations are down as one moves away from the upper outlet of the axial duct 21.

Claims (16)

1. Filter (1) for purifying a combustion engine liquid, in particular lubricating oil, comprising: - a housing (2, 3) having in a base (B) an inlet (2a) of raw liquid and an outlet (2b) of purified liquid, the base (B) including a female connector (CF) internally delimiting an axial duct (21) access to the outlet (2b) and to a purge channel (2d); - a filter insert (4) provided with an annular filter medium (5) internally delimiting a hollow space (6) which opens axially towards the base (B) via an opening (04) at an axial end (4b) of the filter insert, and a holding element (8; 9) integral with the filter medium (5); - a rod (T) which projects axially outwards with respect to said axial end (4b), comprising a plug (10) intended to close the purge channel (2d); characterized in that it comprises a tube (7) integral with the holding element (8; 9), the rod (T) comprising a male connector (CM) consisting at least in part of a section (7c) of the tube for sealingly engaging in the axial duct (21) of the female connector (CF) and delimiting a between The interior space and the outlet (2b) in a state of final coupling of the tube axial duct determined sealing section (14a, 14b, 14c) distributed over its lateral external face, and in that in the final coupling state, it is obtained: - by the plug (10), a first sealing zone (Cl) female rod-connector for closing the purge channel (2d); by at least one of the determined sealing elements (14b, 14c), a second sealing zone (C2) female tigeconnector separating the axial duct (21) from a peripheral zone (Zl) surrounding the female connector (CF ) and in communication with the raw liquid inlet (2a). 2. Filter according to claim 1, in which the determined sealing elements (14a, 14b, preferably made in one piece with the section, comprise an annular surface an annular sealing contact (C3), preferably a radial annular contact, with the internal face of a tubular portion (PT) belonging to a flange axial end (4b) from which the interior space (6) is sealingly separated from the peripheral zone (Zl). 3. Filter according to claim 1 or 2, in which the male connector (CM) has an external face which has circumferential grooves (G) axially spaced apart by a plurality of annular beads (14a, 14b, 14c) formed integrally with said section (7c) so as to form one of the tube, from which includes said annular beads and which produces the second sealing zone (C2) by a plurality of radial annular contacts against an internal face substantially Filter according to claim 3, in which the filter insert ( 4) extends longitudinally between a first flange (8) distal of the outlet (2b) and a second flange (9) proximal of the outlet (2b), the second flange (9) delimiting said opening (04) by a border which is traversed by the tube (7), the labyrinthine seal (14) having a first annular end, adjacent to one of the circumferential grooves, which includes an annular surface in radial sealed contact (C3) against said edge. 5. Filter according to claim 4, wherein the labyrinthine seal (14), preferably made from a single plastic material, comprises a maximum external diameter in a configuration at rest, the maximum diameter being formed by the annular surface d '' a determined bead (14a) among the annular beads (14a, 14b, 14c) and between 101% and 110% of an external diameter (D14) of the other beads (14b, 14c). 6. Filter according to claim 5, in which the determined bead (14a) extends in outside of the duct axial (21) formed by the connector female (CF), of preferably to engage by an annular sealing contact (C3) against a lower flange (9) of the filter insert (4), while the other beads (14b, 14c), at least three in number, preferably at least five in number, are in radial annular contact against an internal face of the female connector (CF). 7. Filter according to any one of the preceding claims, in which the rod (T) and the filter insert (4) form part of a removable cartridge (CA) adapted to release the purge channel (2d) during the extraction of the cartridge (CA) from the interior volume (V). 8. Filter according to claim 7, wherein the rod (T) is obtained by fixing a closure element (19) including the plug (10) at a lower end (7a) of the tube (7), preferably by engagement of elastically deformable tabs (19c) against at least one grip edge (71), the shutter element (19) and the tube (7) being made integral in sliding, during sliding of the rod (T) in the female connector (CF), in an assembled state of the removable cartridge (CA). 9. Filter according to any one of the preceding claims, in which the tube (7) is in one piece of plastic. 10. Filter according to any one of the preceding claims, in which the section (7c) of the tube (7) is an intermediate portion of the tube, which extends between: a lower end portion of the tube opening into the axial duct (21) and making it possible to connect a rod end designed separately from that which includes the plug (10); and an upper end portion of the tube surrounded by and preferably provided 11. Filter according to any one of the preceding claims, in which the section (7c) of the tube (7) forms a barrier adapted to retain purified liquid in the interior space, at least in an annular space delimited between an internal face. (5b) of the filter medium (5), the tube (7) and which extends above a lower flange (9) of the filter insert (4). 12. Filter according to any one of the claims comprises an internal face which has: a first diameter DI in a first cylindrical section in which is engaged in sealed radial contact a lower end of the plug (10), a second diameter D2 in a second cylindrical section in which is engaged in sealed radial contact an upper end of the plug (10), and a third diameter D3 in a third cylindrical section on which at least three of the annular beads (14b, 14c) of the labyrinth seal are engaged. - a drain orifice, located between the first section and the second section, - an orifice belonging to the outlet (2b), located in a section variation zone between the second section and the third section knowing that the female connector (CF) and the tube (7) extend around the same axis central (A), and knowing that the following relation is satisfied: DI <D2 <D3. 13. removable cartridge (CA) of the filter defined in any one of claims 1 to 12, intended for the separation of impurities in a lubricating liquid and provided with a closure element (19) which is connected to the filter insert (4) by the tube (7), the tube (7) and the closure element (19) defining the rod (T) which extends through an annular flange (9) forming the 'lower axial end (4b) of the filter insert preferably in the form of a labyrinthine seal being made in one piece on which the closure element (19) is fixed, the male connector (CM) s extending axially from a sealing zone resulting from a radial annular contact between the rod and the annular flange - Up to the plug (10) of the sealing element (10) which has a narrower radial size than the determined sealing elements (14a, 14b, 14c). 14. Removable cartridge (CA) according to claim 13, in which the determined sealing elements (14a, 14b, comprise an annular surface defining an annular sealing contact (C3), preferably a radial annular contact, with the internal face of a tubular portion (PT) belonging to the annular flange (9) forming the end 15. Removable cartridge (CA) according to claim 13 or 14, in which the determined sealing elements (14a, 14b, 14c) are included in a labyrinth seal (14) which: - extends axially closer to the annular flange (9) than to the plug (10); and / or has circumferential grooves (G) axially spaced apart by a plurality of annular beads (14a, 14b, belonging to the labyrinthine seal (14). 16. Removable cartridge (CA) according to claim 15, in which the determined sealing elements comprise at least three annular beads (14a, 14b, 14c), preferably at least five annular beads, at least one of the circumferential grooves (G) formed between two successive annular beads being axially narrower in at least two zones of the groove which are diametrically opposite, due to a local allowance in said two successive beads. 17. removable cartridge (CA) according to any one of claims 13 to 16, wherein the filter insert (4) comprises an additional flange said upper (8) opposite the annular flange (9) forming the lower lower axial end (4b) of the filter insert, the lower annular flange (9) being provided with an opening (04) centered on a central axis (A), for the passage of the tube (7) and the purified liquid coming from of the interior space (6) delimited by the filtering medium (5), at least one, and preferably each, of the two annular flanges (8, 9) having: - a tubular portion (PT) having an internal face provided with one or more protruding reliefs (8e, 9e) inwards; - A substantially planar and sealed radial portion (8r, 9r), extending around an opening, and on which is fixed an annular axial end (5c, 5d) of the filtering medium (5); in which the tube (7) has an external face on which projections (37a, 37b, 14a, 27) project radially outward, delimiting between them at least one annular retaining groove (GB, GH), and / or the sliding flange, in the direction of the central axis (A), thanks to the projecting reliefs (8e, 9e) inwards and to a projecting edge, as regards the tubular portion (PT) of at minus one of the two annular flanges (8, 9).