CN112443437A

CN112443437A - Fuel filter

Info

Publication number: CN112443437A
Application number: CN201910816993.2A
Authority: CN
Inventors: 乔基奥·基隆迪
Original assignee: Shanghai Sofima Automobile Filter Co ltd
Current assignee: Shanghai Sofima Automobile Filter Co ltd
Priority date: 2019-08-30
Filing date: 2019-08-30
Publication date: 2021-03-05
Anticipated expiration: 2039-08-30
Also published as: CN112443437B

Abstract

A fuel filter (10) comprising: a housing (20) having a collection chamber (26) for collecting water separated from the fuel; a water level sensor (30) extending into the housing (20) and provided with an electrical water level contact (33) extending into the collection chamber (26) and an intermediate electrical contact (34) arranged within the housing (20) but outside the collection chamber (26); and a water separator element (40) comprising: a filter element (41, 42); a cartridge support (43, 44) provided with a through opening (444), the through opening (444) being crossed by the water level sensor (30) so that the electrical water level contacts (33) extend into the collection chamber (26); and a conductive element (50) provided on the cartridge support (43, 44) and provided with: a water level electrode (51) extending into the collection chamber (26); and a contact electrode (52) electrically connected to the water level electrode (51), distant from the water level electrode (51), and in contact with the intermediate electrical contact (34) of the water level sensor (30).

Description

Fuel filter

Technical Field

The present invention relates to a gas oil (diesel oil), in particular for internal combustion motor vehicles, an element for separating water from the fuel oil, and a fuel filter provided with such a water separator element.

Background

Water separator elements are known, each comprising an electrically conductive element adapted to cooperate with the electrical contacts of the water level sensor to extend these electrical contact members into a chamber for collecting water, the chamber being located at the bottom of a housing of a fuel filter containing the water separator element.

There is a need in the field of water separator elements that, since they need to be replaced regularly in order to restore the complete function of the fuel filter, they are replaced by reliable water separator elements that perform the above-mentioned function of effectively separating water (that is, they are difficult to tamper with and counterfeit), while at the same time they allow an effective signaling of the water accumulation in the collection chamber.

There is a further need to be able to make the electrical contact directly between the electrical contact of the water level sensor and the electrically conductive element of the water separator element less susceptible to breaking in a simpler, more stable manner, even in the presence of increased vibrations or impact forces, and also to allow a correct mutual positioning between the water level sensor and the water separator element.

Another requirement is to promote proper mutual positioning between the water level sensor and the water separator element regardless of the angular position of the water separator element in the housing.

Another need exists in the art to reduce the production costs of the fuel filter and to simplify the production process of the fuel filter, in particular the production process of the water separator element, which is a consumable item that is frequently replaced during the service life of the fuel filter.

It is therefore an object of the present invention to satisfy this need of the prior art within the scope of a simple, rational and economical solution.

These objects are achieved by the features of the invention given in the independent claims. The dependent claims outline preferred and/or particularly advantageous aspects of the invention.

Disclosure of Invention

Specifically, the invention provides a fuel filter, comprising:

a housing having a collection chamber at a bottom of the housing for collecting water separated from the fuel;

a water level sensor extending into the housing and provided with electrical water level contacts extending into the collection chamber (i.e. electrical contacts measuring the desired water level) and intermediate electrical contacts arranged within the housing outside the collection chamber; and

a water separator element housed in the housing, wherein the water separator element comprises:

a filter element adapted to be traversed by fuel;

a filter element support provided with a through opening penetrated by the water level sensor so that the electric water level contact extends into the collection chamber; and a (single) (electrically) conductive element provided on the cartridge support, wherein the conductive element is provided with:

a water level electrode extending into the collection chamber; and

a contact electrode electrically connected with the water level electrode and distant from the water level electrode, wherein the contact electrode is in contact with the intermediate electrical contact of the water level sensor.

Thanks to this solution, the above mentioned objects can be achieved in an efficient, economical and reliable manner.

In particular, thanks to this solution, an effective protection of the original components of the fuel filter is obtained, while the costs of manufacturing easily replaceable components (such as the water separator elements known so far) can be reduced, thus also obtaining a significant simplification of the production process of the fuel filter and its components.

According to an aspect of the invention, a sealed connection may be defined between the water level sensor and the through-going opening.

Thanks to this solution, a separation between the water collection chamber and the environment of the casing is obtained, which separation is aimed at filtering the fuel and/or separating the water from the fuel itself.

Furthermore, the water level sensor may have a longitudinal extension along a longitudinal axis, and when the water level sensor is inserted (axially) into the through-opening, the through-opening may peripherally surround a (dielectric) connection portion of the water level sensor axially between the electrical water level contacts and the intermediate electrical contacts.

Thanks to this solution, the electrical level contacts (and the level electrodes) are firmly arranged below the level of the filter cartridge in the housing (in the water collection chamber), and the intermediate electrical contacts are arranged inside the volume surrounded by the filter cartridge, so that the purpose of making the electrical contacts in direct electrical contact with the contact electrodes of the water separator element can be easily and efficiently achieved.

Also, according to a preferred embodiment, the filter cartridge may have a substantially tubular shape extending around a longitudinal central axis, the water level sensor being axially inserted in the filter cartridge.

In practice, the water level sensor is conveniently and efficiently inserted into the filter cartridge, saving space in the housing, while allowing the filter cartridge to be easily installed in and/or removed from and/or replaced in the housing.

Advantageously, the cartridge support may comprise a lower plate fixed to the lower end of the cartridge close to the collection chamber, the through-opening being made in the lower plate.

Advantageously, the filter cartridge support may comprise (or consist of) a support candle which is coaxially fixed to the filter cartridge (inside or outside), the through-opening being formed in the lower end region of the support candle (close to the collection chamber).

Due to this solution, the electrical water level of the water level sensor can be electrically shocked to reach the collection chamber provided in the housing. According to another aspect of the present invention, the through-hole may be surrounded by a guide body for the water level sensor.

Thanks to this solution, a self-aligning axial connection is obtained between the water separator element and the water level sensor, i.e. between the water level sensor and the through-opening, during mounting of the water separator element in the housing.

According to a preferred embodiment, the guide body may comprise or be made of a plurality of individual (radial) protrusions, one side (inner side, i.e. the side facing the through-opening) of which is located on a common conical surface converging towards the through-opening.

Thanks to this solution, the distribution of the gas oil in the water separator element is in any case optimal and not disturbed by the presence of the guide bodies.

Moreover, such a projection can interact with a possible complementary (radial) seat defined on (the stem of) the water level sensor, allowing to obtain a substantially prismatic connection between them and thus to define a preset mutual angular orientation between the two.

According to another aspect of the invention, the filter element may include a filter (and/or coalescing) membrane for filtering particulate matter present in the fuel.

Alternatively or additionally, the filter element may comprise a hydrophobic net for (eventual) separation of water from the fuel.

Advantageously, the filtering septum and the hydrophobic net may be coaxial to each other and, for example, (radially) separated.

According to a further aspect of the invention, the contact electrode of the water separator element may be elastically deformable.

Due to this solution, the force and stability of the direct electrical contact between the contact electrode and the intermediate electrical contact are increased, thus enabling an increased reliability of the direct electrical contact to be obtained under all conditions of use of the fuel filter (i.e. when subjected to strong vibrations or impact forces, as occurs in normal use of the fuel filter).

Advantageously, the elastic yielding capacity of the contact electrode allows to avoid undesired damages of the contact electrode in unfortunate situations, in which an operator destined to replace the water separator element should be unable to perform the first assembly operation of the housing and be forced to reposition the water separator element in the housing.

Furthermore, the elastically deformable part which makes direct electrical contact between the contact electrode and the intermediate electrical contact consists (only) of the contact electrode of the water separator element, i.e. the part which is periodically replaced when depleted, which allows to reestablish the force of the direct electrical contact each time it is replaced, that is to say, which restores the optimal conditions of the direct electrical contact between the contact electrode and the intermediate electrical contact.

The contact electrode may be radially oriented with respect to the longitudinal center axis and may be elastically deformable in a substantially radial direction for the same purpose.

The contact electrode may be axially oriented with respect to the longitudinal center axis and may be elastically deformable in a substantially axial direction for the same purpose.

According to another aspect of the invention, (each of) the contact electrode and the water level electrode may be defined by two opposite free ends of a single elongated conductive element made in a single (monolithic) body.

Due to this solution, the conductive element and the connection/integration of the conductive element with the cartridge support are particularly advantageous, practical, safe and reliable.

Advantageously, the cartridge support and the conductive element are integrated in one piece.

Another aspect of the invention provides a fuel filter element for separating water from fuel, the fuel filter element comprising: a housing having a chamber for collecting water separated from the fuel for the same purpose as described above; and a water level sensor extending into the housing and provided with electrical water level contacts extending into the collection chamber and intermediate electrical contacts arranged within the housing outside the collection chamber; and

the water separator element includes:

a filter element adapted to be traversed by fuel;

a cartridge support provided with a through-going opening adapted to be passed through by a water level sensor of the fuel filter such that electrical water level contacts extend through the cartridge into the collection chamber; and

a conductive element disposed on the cartridge support, wherein the conductive element is provided with:

a water level electrode configured to extend into the collection chamber; and

a contact electrode electrically connected to and remote from the water level electrode, wherein the contact electrode is configured to contact an intermediate electrical contact of a water level sensor disposed outside the collection chamber.

Drawings

Other characteristics and advantages of the invention will be apparent from reading the following description, given by way of non-limiting example, with the aid of the figures shown in the attached table.

Fig. 1 is an isometric view of a fuel filter according to the invention.

Fig. 2 is a longitudinal sectional view of fig. 1.

Fig. 3 is a cross-sectional view of a water separator element according to the present invention.

Fig. 4 is an exploded view of the water separator element of fig. 1.

Fig. 5 is a view of an alternative embodiment of the contact electrodes of the conductive element of the water separator element according to the invention.

Fig. 6 is a longitudinal sectional view of a housing of the fuel filter and a cover of a water level sensor of fig. 1.

Detailed Description

With particular reference to these figures, a fuel filter adapted to separate water from fuel, in particular gas oil in a diesel engine of a motor vehicle, is generally indicated at 10.

With particular reference to fig. 1 and 2, the fuel filter 10 comprises a casing 20, which casing 20 in turn comprises, for example, a (lower) cup-shaped body 21 and a (upper) cover 22 adapted to close the cup-shaped body 21.

The cup-shaped body 21 is screwed (preferably hermetically) to the cap 22, or to the cap 22 by inserting a sealing ring 210.

In practice, the housing 20 (i.e. the cup-shaped body 21 and the lid 22) encloses an internal (closed) volume therein.

The housing 20, in this example the cover 22, comprises an inlet duct 23 for the gas oil to be filtered and an outlet duct 24 for the filtered gas oil.

Also, the housing 20 (in this example the cup-shaped body 21) comprises a discharge duct 25, this discharge duct 25 being intended for water accumulated at the bottom of the housing 20 (i.e. at the bottom of the cup-shaped body 21), for example in a collection chamber 26, this water separated from the fuel being collected in the collection chamber 26.

The collection chamber 26 is defined by the lower part of the internal volume of the casing 20, close to the bottom of the cup-shaped body 21.

Furthermore, a cap 27 (see fig. 2) removably blocks the discharge duct 25, for example by means of a threaded connection.

The entire housing 20 (i.e. both the cup-shaped body 21 and the cover 22) is made of an electrically insulating (dielectric) material, for example a plastic, such as a polyamide-based material (PA) or a polyethylene-based material (PBT).

As shown in fig. 2, the fuel filter 10 includes a water level sensor 30, for example, the water level sensor 30 may also be independently protected, the water level sensor 30 being configured to sense the level of water accumulated in the collection chamber 26 during fuel filtration, the water level sensor 30 being associated with an electronic unit (not shown) for controlling the vehicle, as is known to those skilled in the art.

The water level sensor 30 comprises a longitudinal rod 31, for example a longitudinal rod 31 being substantially hollow and having a central longitudinal axis a.

The rod 31 is made of an electrically insulating (dielectric) material, for example a plastic, such as a polyamide-based material (PA) or a polyethylene-based material (PBT).

The rod 31 has a cylindrical extension 310, the upper end of which 310 is constrained to the cover 22 (and directly derived from the cover 22), the lower end of the cylindrical extension 310 being closed, for example, by a closing cap 311.

The closing cap 311 is of a conical or frustoconical shape converging towards the free end of this shape (or the closing cap 311 has at least one axial extension of a conical or frustoconical shape converging towards the free end of this shape).

The closing cap 311 is for example removably associated with the cylindrical extension 310, preferably by means of an interference or snap connection or other known connections (such as a screw thread and/or bayonet or similar).

The closing cap 311 has a bottom wall on which a (circular) opening, for example a central opening, is defined, which is coaxial with the longitudinal axis a of the stem 31.

In an alternative embodiment, the closing cap 311 and the cylindrical extension 310 may be non-detachably associated, for example may be made as a single body; in this case, the upper end of the cylindrical extension 310 is adapted to be detachably connected to a catch provided on the inner wall of the cover 22.

In this example, the water level sensor 30 is integrated on the cover 22, in particular a stem 31 is derived at the bottom of the cover 22 itself and made in one piece with the cover 22, and the stem 31 extends into the internal volume of the casing 20 towards the bottom of the cup-shaped body 21 (at a distance from the bottom of the cup-shaped body 21 that is not zero).

However, it is not excluded that the rod 31 is a body separate from the cover 22, preferably connected to the cover 22 by a fixing member.

The water level sensor 30 also comprises an electronic control circuit 32, preferably the electronic control circuit 32 is defined by an electronic board, wherein the electronic control circuit 32 is housed in a housing seat made in the cover 22 (and/or in the stem 31).

The rod 31 supports a pair of separate electrical contacts, one of which is an electrical water level contact 33 and the other of which is an intermediate electrical contact 34, which are located on a surface of the exterior of the rod 31 itself (either exposed or arranged on the exterior of the rod 31 itself), i.e. they are visible and/or contactable from the outside of the rod 31.

Electrical water level contacts refer to electrically conductive surfaces of the water level sensor 30 which are exposed or protruding from the rod 31 (the plastic from which the rod 31 is made) and which are adapted to be exposed, in use, to the fluid being filtered, i.e. to the fuel and/or water accumulated in the collection chamber 26, in direct contact therewith, so as to define a probe exposed to the fluid of the water level sensor 30. The electric water level contact 33 and the intermediate electric contact 34 of the water level sensor 30 are substantially axially offset from each other, that is to say they are placed in different axial positions along the longitudinal axis a of the rod 31.

For example, the electric water level contact 33 and the intermediate electric contact 34 of the water level sensor 30 are placed at different heights in the casing 20, preferably in two positions at different distances (non-zero) from the bottom of the cup-shaped body 21.

Both the electric water level contact 33 and the intermediate electric contact 34 of the water level sensor 30 are made of an electrically conductive material, for example of metal (for example steel, preferably stainless steel, aluminium or copper), and are electrically connected to one of the electric terminals of the electronic control circuit 32, as will be discussed more clearly below.

The electrical water level contacts 33 are configured to extend directly into the collection chamber 26, i.e. to be introduced and arranged in the collection chamber 26.

For example, the electrical water level contacts 33 are defined at the free (lower) end of the stem 31 remote from the cover 22 (and close to the bottom of the cup-shaped body 21).

Preferably, the electric water level contacts 33 extend axially from the lower free end of the stem 31 by an axial extension (non-zero) and axially extend the stem 31 itself.

Preferably, the electric water level contacts 33 (i.e. the free lower ends of the electric water level contacts 33) are arranged at a predetermined distance (non-zero) from the bottom of the cup-shaped body 21 (and the upper ends of the electric water level contacts 33, which are constrained or connected to the rod 31, are arranged at a distance from the bottom greater than said predetermined distance).

In the example shown, the electrical water level contacts 33 are defined by an axisymmetric body (solid in this example), wherein preferably the central axis of symmetry coincides with the longitudinal axis a of the rod 31.

Preferably, but in a non-limiting manner, the electric water level contact 33 comprises an upper cylindrical extension and a conical extension converging towards its lower free end.

The electrical water level contact 33 is a (lower) end extension that emerges (i.e. protrudes axially) from the stem 31 of the conductive column 330 (e.g. a metal column), the upper extension of the electrical water level contact 33 being contained in the stem 31 and its top extending (and entering) into a housing seat of the electronic control circuit 32, with which the upper extension of the electrical water level contact 33 is in (direct) electrical contact.

The conductive post 330 has, for example, at its upper end, a connector body adapted to be connected (for example, snap-fit or by interference fit) to the cover 22, so that the upper end of the conductive post 330 opens into the housing seat of the electronic circuit to be electrically connected to one electrical terminal of the electronic circuit (for example, to the first electrical terminal of the electronic circuit).

The conductive cylinder 330 is inserted into the opening of the closing cap 311 to perform measurements on the lower extension of the conductive cylinder 330, for example the conductive cylinder 330 is axially locked within the opening of the closing cap 311 by a constraint connection (for example a snap connection) obtained by a plurality of radially flexible teeth made in the closing cap 311, which snap-insert into an annular seat made in the conductive cylinder 330 and axially separate the upper extension from the lower extension in the stem 31 of the conductive cylinder itself, which defines the electrical water level contact 33 outside the stem 31.

Even though the intermediate electrical contact 34 is located in the internal volume of the housing 20, it is configured to be located outside the collection chamber 26, i.e., at a height in the housing 20 that is not reached by the level of water accumulated in the internal volume of the housing 20.

In practice, the intermediate electrical contact 34 is at a predetermined distance (non-zero) from the bottom of the cup-shaped body 21, which is greater than the distance of the upper end of the electrical level contact 33 from the bottom of the cup-shaped body 21, i.e. greater than the distance of the free end of the stem 31 from the bottom of the cup-shaped body 21.

The intermediate electrical contact 34 is axially (and electrically) separated from the electrical water level contact 33 (by the axial extension of the dielectric of the rod 31 between the intermediate electrical contact 34 and the electrical water level contact 33).

For example, the intermediate electrical contact 34 is defined at the (lower) end of the cylindrical extension of the stem 31 remote from the lid 22 (and close to the bottom of the cup-shaped body 21).

The intermediate electrical contact 34 is for example at a non-zero radial distance from the longitudinal axis a of the rod 31.

In the example shown, the intermediate electrical contact 34 is defined by a substantially annular (e.g. substantially axially symmetrical) body, wherein preferably the central symmetry axis coincides with the longitudinal axis a of the rod 31.

In the preferred embodiment shown in the figures, the (entire) radially outer wall of the intermediate electrical contact 34 is exposed outside the rod 31, that is to say the intermediate electrical contact 34 itself defines the intermediate electrical contact 34 adapted to be internally supported by the outer surface of the rod 31.

According to a preferred embodiment, the (rigid) intermediate electrical contact (34) is a radial contact facing outwards (i.e. facing the opposite side with respect to the longitudinal axis a).

It is not excluded that the axially lower wall of the intermediate electrical contact 34 is exposed outside the stem 31 (projecting radially from the stem 31), that is to say that the intermediate electrical contact 34 itself defines the intermediate electrical contact 34 adapted to be contacted axially from below.

According to a preferred embodiment, the (rigid) intermediate electrical contact 34 is a downward facing axial contact, i.e. facing the bottom of the cup-shaped body 21 (or generally the housing 20).

For example, the intermediate electrical contact 34 is defined by an annular (flat and elongated) strip folded about a central axis (coinciding with the longitudinal axis a of the rod 31) and connected (substantially) at the opposite end.

In a simplified embodiment, an incomplete bond may be provided between the opposite ends of such a folded strip, i.e. there is no (dielectric) circumferential gap between them.

In practice, the intermediate electrical contact 34 is wound on an axial portion of the rod 31, for example on a cylindrical extension of the rod 31.

For example, the intermediate electrical contact 34 may be or comprise at least one conical axial extension converging towards a lower free end thereof, or the intermediate electrical contact 34 may be completely cylindrical.

Alternatively, the intermediate electrical contact 34 may be configured as a flat foil or as a circular sector (i.e. not extending completely over the entire curved portion, but only a limited circular arc). Likewise, the intermediate electrical contact 34 may also be or comprise at least one substantially conical axial extension converging towards the lower free end, or in any case the end of which is inclined.

The intermediate electrical contact 34 is an extension of a (lower) end of a conductive foil 340 (e.g., a metal foil), the upper extension of the conductive foil 340 being secured to the lid 22, i.e., the upper extension of the conductive foil 340 being electrically connected with the electronic circuitry within the housing base.

For example, the conductive foil 340 is arranged (completely) outside the rod 31, preferably wrapping a circumferential portion (smaller than the bent portion, e.g. smaller than a right angle) of the rod 31, i.e. a circumferential portion of the cylindrical extension of the rod 31.

In practice, the conductive foil 340 extends axially upwards towards the intermediate electrical contact 34, up to the upper restraining end of the rod 31.

The conductive foil 340 has, for example, at its upper end, a connection extension defined by a fold (90 °) resting on the lower surface of the cover 22, i.e. under the housing seat of the electronic control circuit 32.

The connection screw 341, for example a conductive screw, is adapted to electrically connect the conductive post 340 to one of the electrical terminals of the electronic control circuit 32 (i.e. to the second electrical terminal of the electronic control circuit 32) by fixing the conductive post 340 (i.e. the connection extension of the conductive post 340) to the cover 22 through the lower wall of the cover 22 to guide the conductive post 340 into the housing seat of the electronic control circuit 32.

In practice, the head of the connection screw 341 (disposed in the internal volume of the casing 20) is in direct electrical contact with the conductive post 340, and the tip of the connection screw 341 (disposed outside the internal volume of the casing and inside the housing seat of the electronic circuit) is electrically connected to one of the electrical terminals of the electronic circuit (i.e. to the second electrical terminal of the electronic circuit).

With particular reference to fig. 2, 3 and 4, the fuel filter 10 includes a water separator element, generally designated by the numeral 40, which may also be protected independently of the above description, configured to separate or facilitate separation of the water and fuel, as well as to facilitate decantation of the water (i.e., positioning of the water in the collection chamber 26).

The water separator element 40 is integrated in (or comprises) a replaceable cartridge filter, i.e. once worn, it can be replaced with a new (identical) cartridge filter to restore the full function of the fuel filter 10.

The water separator element 40 is adapted to be inserted into the interior volume of the housing 20, thereby dividing the interior volume of the housing 20 into two separate environments: a first environment (dirty side) which communicates with the inlet conduit 23, i.e. which is located upstream of the water separator element 40 in the direction of fuel flow from the inlet conduit 23 to the outlet conduit 24; and a second environment (clean side) which communicates with the outlet conduit 24, i.e. which is located downstream of the water separator element 40 in the direction of fuel flow from the inlet conduit 23 to the outlet conduit 24.

According to a preferred embodiment, the water separator element 40 comprises a filter cartridge adapted to be crossed (radially) by the fuel entering the inner volume of the casing 20 through the inlet duct 23 and exiting through the outlet duct 24.

The filter cartridge has overall a substantially tubular shape, for example substantially cylindrical or annular (axisymmetric), which is formed around a longitudinal central (symmetry) axis B.

Preferably, the filter cartridge is inserted into the interior volume of the housing 20 so as to at least circumferentially surround an axial portion of the water level sensor 30, as will be described more clearly below. For example, the filter cartridge is arranged inside the housing 20 substantially coaxially with the water level sensor 30, i.e. the longitudinal central axis B of the filter cartridge coincides with the longitudinal axis a of the water level sensor 30.

In practice, the filter cartridge has an upper end close to the cover 22 and a lower end close to the bottom of the cup-shaped body 21, the lower end being preferably arranged at a predetermined distance from the bottom of the cup-shaped body 21, for example greater than or equal to the predetermined distance from the bottom of the cup-shaped body 21 at which the electrical level contacts 33 of the level sensor 30 are located.

Preferably, the filter cartridge comprises a filter membrane 41 for filtering particulate matter (i.e. solid or semi-solid particles of impurities defined as fuel) from the fuel.

The filtering septum 41 is tubular (generally cylindrical), has a star-shaped cross-section (when the filtering septum 41 is a pleated septum) or a substantially annular cross-section (when the filtering septum 41 is a depth septum), and extends about a central longitudinal axis B.

The outer diameter of the filter membrane 41 is substantially (slightly) smaller than the inner diameter of the housing 20, so that a gap is defined outside the filter membrane 41, which gap for example defines at least a part of the above-mentioned first environment (dirty side).

The inner diameter of the filter membrane 41 is (much) larger than the outer diameter of the water level sensor 30, such that a substantially cylindrical inner cavity is defined in the filter membrane 41 (i.e. between the inner wall of the filter membrane 41 and the outer wall of the water level sensor 30), which inner cavity for example defines at least a part of the above-mentioned second environment (clean side).

The filter membrane 41 may (also) be of a coalescing type in order to improve the separation of water from the gas oil.

Alternatively, the coalescing membrane may be mounted on the filter membrane 41, for example axially mounted to (the outside or inside of) the filter membrane 41, preferably in contact with the wall of the filter membrane 41.

According to a preferred embodiment, the filter cartridge includes a hydrophobic net 42 (or final separator membrane) for final separation of water and fuel.

In practice, the hydrophobic net 42 is adapted to be crossed (radially) by the fuel and to block the water contained in the fuel, so as to direct it by gravity into the collection chamber 26.

The hydrophobic net 42 is tubular (cylindrical overall), preferably with thin walls, formed around the central longitudinal axis B.

In practice, the hydrophobic net 42 is coaxial to the filtering septum 41, for example at a distance different from zero from the filtering septum 41.

According to a preferred embodiment, the filter insert is passed from the outside inwards (radially).

Here, the fuel to be filtered enters from an inlet duct 23, which inlet duct 23 is a peripheral (or external) duct, i.e. this inlet duct 23 opens into the casing 20 in a peripheral region of the cover 22 (close to the side wall of the cover 22), i.e. into the cover 22, or in any case this inlet duct 23 is in fluid communication with the environment radially interposed between the filter cartridge and the inner wall of the casing 20, while an outlet duct 24 (from which the filtered fuel exits) is defined by a central (or internal) duct, preferably by a cylindrical end extension 24', i.e. the outlet duct 24 opens centrally into the casing 20, i.e. into the cover 22 (coaxial with the filter cartridge).

Furthermore, in this case, a hydrophobic net 42 is located inside the filtering septum 41 so as to divide the inner cylindrical chamber defined inside the filtering septum 41 into two chambers: an annular chamber located outside the hydrophobic net 42 and inside the filtering membrane 41; an inner cylindrical chamber, which (directly communicating with the outlet conduit 24) is located within the hydrophobic mesh itself.

In the embodiment shown, the outer diameter of the hydrophobic mesh 42 is (much) smaller than the inner diameter of the filter membrane 41, so that the hydrophobic mesh 42 is at a distance (non-zero) from the inner wall of the filter membrane 41 and a gap is defined between the hydrophobic mesh 42 and the inner wall of the filter membrane 41, which gap for example defines the above-mentioned outer annular chamber.

According to a preferred embodiment, the inner diameter of the hydrophobic net 42 is larger than the outer diameter of the water level sensor 30, such that a substantially annular gap is defined in the hydrophobic net 42 (i.e. between the inner wall of the hydrophobic net 42 and the outer wall of the water level sensor 30), which substantially annular gap defines the aforementioned inner cylindrical chamber.

The water separator element 40 also includes a cartridge support.

In the preferred embodiment shown in the figures, the cartridge support (all its constituent parts) is made of an electrically insulating (dielectric) material, for example a plastic material (for example polyamide-based (PA) or polyethylene-based (PBT)).

In an alternative embodiment, the cartridge support (all of its components) may be made of an electrically conductive material. In this case, the cartridge support may be made of an electrically conductive plastic (e.g. an electrically conductive polymer and/or an electrically conductive composite with a polymer matrix (such as an aliphatic polyamide based) and a reinforcing material, such as carbon based, e.g. carbon nanotubes and/or carbon black) or a metal (or metal alloy) or a combination thereof.

Preferably, the cartridge support comprises a filter membrane support 43, the filter membrane support 43 being configured to support the filter membrane 41.

Preferably, the filter membrane support 43 comprises an upper plate 431, which upper plate 431 is non-detachably fixed (for example, by heat-sealing or gluing) to the upper end of the filter membrane 41.

The upper plate 431 is substantially annular and has an upper central aperture 432, the upper central aperture 432 being centered about the longitudinal central axis B of the filter cartridge (i.e., the filter membrane 41).

The upper annular gasket 433 is received on a receiving seat provided in the upper central hole 432.

According to a preferred embodiment, the inner diameter of the upper central hole 432 is larger than the outer diameter of the water level sensor 30, so that the water level sensor 30 can be inserted axially into the upper central hole 432 itself, preferably with (ample) radial clearance.

The upper central hole 432 of the upper plate 431 (of the filtering septum support 43) is mounted on the cylindrical end extension 24' on the outlet duct 24, in which outlet duct 24 the upper end of the stem 31 of the water level sensor 30 is housed (coaxially and with radial clearance).

In practice, coaxial centering is obtained between the water level sensor 30 and the filter cartridge (i.e. the filter membrane 41) by fitting the upper central hole 432 of the upper plate 431 onto the inner cylindrical end extension 24' of the outlet conduit 24.

The upper annular gasket 433 is adapted to be (radially) compressed between the inner cylindrical end extension 24' of the outlet duct 24 and the inner edge of the upper central hole 432 of the upper plate 431, so that a substantially cylindrical inner chamber (which defines the second environment) is in communication with the outlet duct 24 and is separated hydraulically and hermetically from the first environment (i.e. from the inlet duct 23).

Preferably, the filtering septum support 43 comprises a lower plate 434, which lower plate 434 is non-removably fixed (for example, by heat-sealing or gluing) to the lower end of the filtering septum 41.

In the illustrated embodiment, the lower plate 434 is substantially annular and has a lower central aperture 435, the lower central aperture 435 being centered about a longitudinal central axis B of the filter cartridge (i.e., the filter membrane 41).

The inner diameter of the lower center hole 435 is, for example, larger than or equal to the inner diameter of the upper center hole 432 of the upper plate 431, so that the water level sensor 30 can be inserted axially with (ample) radial clearance (also) into the lower center hole 435 itself.

According to a preferred embodiment, the lower annular gasket 436 is housed in a housing seat provided externally to the lower plate 434, i.e. on the outer jacket of the lower plate 434.

The lower annular gasket 436 is adapted to be compressed (radially) between the outer jacket of the lower plate 434 and the cylindrical portion of the inner wall of the casing 20 (for example the cup-shaped body 21), so that the outer gap defined between the inner wall of the casing 20 and the filtering septum 41 (the filtering septum 41 defining the first environment) is in (definitive) communication with the inlet duct 23 and is hydraulically sealed off from the second environment (i.e. the outlet duct 24).

In the example shown, the filter membrane support 43 comprises an outer longitudinal candle 437, which outer longitudinal candle 437 is inserted (to measure) into the inner cavity of the filter membrane 41, in practice, wrapping the filter membrane 41 internally.

The outer longitudinal candle 437 comprises, for example, a tubular body having a diameter substantially equal to the inner diameter of the filter membrane 41, which is provided with a plurality of radial through openings.

In this example, outer longitudinal candles 437 are coaxially disposed within filter membrane 41, with the upper ends of outer longitudinal candles 437 being affixed (non-removably, e.g., by gluing or heat sealing) to upper panel 431 and the lower ends of outer longitudinal candles 437 being affixed (non-removably, e.g., by gluing or heat sealing) to lower panel 434.

For example, the outer longitudinal candle 437 includes an annular shelf 438 (preferably provided with one or more seats at the top that open toward the upper plate 431), the annular shelf 438 projecting in a radially inward direction, the annular shelf 438 being provided at a position near the upper end of the outer longitudinal candle 437 itself and overlapping axially (with an axial spacing different from zero) through the central portion (around the upper central hole 432) of the upper plate 431.

The cartridge support further includes a hydrophobic mesh support 44, the hydrophobic mesh support 44 configured to support the hydrophobic mesh 42.

The hydrophobic net support 44 may be non-removably associated with the filtering septum support 43, as shown in the example, or removably associated (for example by snap hooks or other types of hooks or connectors) with the filtering septum support 43.

Furthermore, the hydrophobic net support 44 may be associated with the filtering membrane support 43 such that there is no mutual degree of freedom between them, i.e. a rigid connection (as shown in the example), or they may be connected to each other to allow mutual movement, e.g. rotation about the longitudinal central axis B, at least with respect to a certain level of freedom.

Preferably, the hydrophobic net support 44 comprises an inner longitudinal candle 441, which inner longitudinal candle 441 is inserted (to measure) inside and/or outside the inner chamber of the hydrophobic net 42, in practice, wrapping the hydrophobic net 42.

The inner longitudinal candle 441 comprises, for example, a tubular body having a diameter substantially equal to the inner diameter of the hydrophobic net 42, which is provided with a plurality of radial through openings.

In this example, the inner longitudinal candle 441 is coaxially disposed within the hydrophobic web 42 and is affixed (non-removably, e.g., by co-molding, gluing, or heat sealing) to the hydrophobic web 42.

The inner longitudinal candle 441 has an open upper end from which one or more teeth 442 (or the annular edge of the entire extension of the inner longitudinal candle 441) are derived radially outwardly, which are adapted to be interposed between the annular shelf 438 of the outer longitudinal candle 437 and the inner (lower) face of the upper plate 431 (e.g., received in corresponding seats of the open-top annular shelf 438) to be substantially sandwiched (and non-rotatable) therein.

The hydrophobic web support 44 also includes a lower plate 443 that is non-removably secured (e.g., by heat sealing or gluing or being made integral with the inner longitudinal candle 441) to the lower end of the inner longitudinal candle 441.

The lower plate 443 of the hydrophobic net support 44 is substantially annular and has a through-opening 444 (see fig. 3), which through-opening 444 is centered on the longitudinal central axis B of the filter element, i.e. the hydrophobic net 42.

Preferably, the through opening 444 is circular or, in any case, has a shape substantially complementary to the shape of the cross section (perpendicular to the longitudinal axis a) of the water level sensor 30, preferably made in the (conical) closing cap 311 of the water level sensor 30.

The inner diameter of the through opening 444 is smaller than or equal to (or, in the limit, slightly larger than) the (largest) outer diameter of the water level sensor 30, so that at least an axial portion of the water level sensor 30 can be inserted axially (from the lower free end of the rod 31) into the through opening 444.

Preferably, at least the electric water level contact 33 of the water level sensor 30 is configured to axially pass through the through-opening 444 when the water separator element 40 is mounted on (the stem 31 of) the water level sensor itself.

For example, the inner diameter of the through opening 444 is an intermediate diameter between the minimum diameter and the maximum diameter of the water level sensor, in other words it is smaller than the maximum outer diameter of the water level sensor 30 (i.e. the cylindrical extension 310 of the water level sensor 30), larger than the minimum outer diameter of the water level sensor 30, i.e. larger than the minimum diameter of the (conical) closing cap 311 (i.e. the free end of the water level sensor itself).

Thus, the water level sensor 30 is adapted to be inserted with its lower free end axially into the through opening 444 until the outer wall of the water level sensor 30 (i.e. the portion of the (conical) closing cap 311 having the same diameter as the through opening 444) abuts against the inner wall of the through opening 444, thereby defining a closing element for the through opening itself.

When the outer wall of the water level sensor 30 abuts against the inner wall of the through opening 444, the electric water level contact 33 of the water level sensor 30 is located at the bottom of the lower plate 443 of the hydrophobic net support 44 (or at a level equal to the lower plate 443), preferably at the bottom of the lower plate 434 of the filtering membrane support 43 (in the collection chamber 26).

At the same time, the intermediate electrical contact 34 of the water level sensor 30 is then located within an inner cylindrical chamber (which is in direct communication with the outlet conduit 24) bounded by the hydrophobic mesh 42, i.e. the intermediate electrical contact 34 is axially interposed between the opposite ends of the filter cartridge (i.e. the opposite ends of the hydrophobic mesh 42 and/or of the filter membrane 41).

In other words, the connection portion 35 (identified between the two dotted lines L1 and L2 in fig. 2 and 6) of the water level sensor 30 is axially interposed between the electric water level contact 33 and the intermediate electric contact 34 (thereby being separated, i.e., a portion is formed on the rod 31 that separates the electric water level contact 33 from the intermediate point contact 34 and physically and electrically separates the electric water level contact 33 from the intermediate point contact 34), and when the outer wall of the water level sensor 30 abuts against the inner wall of the through-hole 444, the connection portion 35 of the water level sensor 30 is inserted into the through-hole 444 to perform measurement.

In practice, the outer diameter of the connection part 35 of the water level sensor 30 is substantially equal to the inner diameter of the through-opening 444.

Thus, a sealed connection is defined between the water level sensor 30 and the through opening 444, which connection is obtained, in the example shown, by a forced connection (plastic to plastic) formed by an interference fit between the outer wall of the water level sensor 30 (i.e. the outer wall of the closing cap 311 at the connection portion 35) and the inner wall of the through opening 444.

The sealing connection may be radial (i.e. applied by compression mainly in the radial direction) or axial (i.e. applied by compression mainly in the axial direction).

Alternatively or additionally, the sealing connection between the water level sensor 30 and the through opening 444 may be achieved by a gasket element.

In this case, a housing seat may be provided in the through opening 444 (or outside the water level sensor 30), in which a lower annular gasket (not shown) is housed, which is adapted to be compressed (preferably, radially, but not exclusively, axially) between the outer wall of the water level sensor 30 (i.e. the outer wall of the closing cap 311) and the inner wall of the through opening 444.

The cartridge support generally includes a guide body 445 (see fig. 3), which guide body 445 is configured to guide and force the water level sensor 30 into the through-opening 444.

In the preferred embodiment shown in the figures, the lower plate 443 of the hydrophobic mesh support 44 (or more generally, the hydrophobic mesh support 44) includes the aforementioned guide body 445 (see fig. 3).

It is not excluded to provide such a guide body 445 on the lower plate 434 of the filtering septum support 43. The guide body 445 is defined in the inner cylindrical chamber of the cartridge, for example, in the example of the hydrophobic mesh 42, it is defined at the top of the lower plate 443 of the hydrophobic mesh support 44 (and at the bottom of the open free end of the inner longitudinal candle 441).

In the preferred embodiment shown in the figures, the guide bodies 445 comprise projections or fins that rise from the upper surface of the lower plate 443 of the cartridge support (i.e., the upper surface of the hydrophobic mesh support 44) and are separated from one another, e.g., equally spaced from one another, and are radially arranged around the through-openings 444.

Each projection has an inner side, i.e. the side facing the longitudinal centre axis B, which is located on a conical surface (complementary to the conical extension of the water level sensor 30) converging towards a through opening 444 common to all projections.

In practice, the inner side of each boss defines a conical surface (discontinuous in extension) converging towards the through opening 444 (from above) and thus guiding the free end of the water level sensor 30 (i.e. the conical closure cap 311) so that the free end of the water level sensor 30 (i.e. the conical closure cap 311) is coaxially arranged in the through opening 444 after the axial translation approaching each other.

Alternatively, it is not excluded that the guide body 445 is made of a single conical (concave) projection rising from the upper surface of the lower plate 443 of the cartridge support (in particular, from the upper surface of the hydrophobic mesh support 44 surrounding the through opening 444), or of a conical profile formed on the inner wall of the through opening 444 itself.

Likewise, the outer diameter of the lower plate 443 of the hydrophobic mesh support 44 is (much) smaller than the inner diameter of the lower plate 434 of the filtration membrane support 43.

The lower plate 443 of the hydrophobic mesh support 44 may also be substantially coplanar with the lower plate 434 of the filtration membrane support 43, or the lower plate 443 of the hydrophobic mesh support 44 is slightly closer to the upper plate 431 relative to the lower plate 434 of the filtration membrane support 43, as shown in the example.

The cartridge support, i.e. the lower plate 443 of the hydrophobic mesh support 44 and/or the lower plate 434 of the filtering membrane support 43, defines a discharge opening 45 (see fig. 2 and 3), which discharge opening 45 is configured to allow the settling of water separated from the fuel oil and to allow the discharge of water into the collection chamber 26.

A discharge opening 45 is defined at the outer annular chamber, i.e. axially aligned and arranged at the bottom of the outer annular chamber.

In practice, the discharge opening 45 is adapted to put in fluid communication the outer circulator chamber (in which the second environment is divided) radially interposed between the filtering septum 41 and the hydrophobic net 42 with the water collection chamber 26, thus allowing the separation of the water from the fuel in such an outer annular settling chamber in the collection chamber 26 itself.

Thus, the collection chamber 26 is in fact part of the second environment, in which the internal volume of the casing 20 is divided by the water separator element 40, and more specifically, of the part of the second environment that is arranged downstream of the filter membrane 41 and upstream of the hydrophobic net 42 in the direction of passage of the fuel from the inlet duct 23 to the outlet duct 24, i.e. the (lower) part of the second environment; in other words, the portion is near the bottom of the housing 20.

In the example shown, the discharge opening 45 is defined by annular gaps interposed between the lower plate 443 of the hydrophobic mesh support 44 and the lower plate 434 of the filtering septum support 43, which are radially and/or axially separated from each other.

Furthermore, it is not excluded that the lower plate 443 of the hydrophobic net support 44 and the lower plate 434 of the filtration membrane support 43 are formed as a single body; in this case, the discharge opening for the water may be defined by one or more eccentric through-openings passing through the single body formed at an outer annular chamber radially defined between the filtering septum 41 and the hydrophobic net 42.

In the example shown, the fuel entering the casing 20 from the inlet conduit 23 passes through the water separator element 40 (radially, from the outside inwards), i.e. it passes first through the filtering septum 41, then through the hydrophobic net 42, and then exits from the outlet conduit 24 (filtered and separated from the water accumulated in the collection chamber 26).

In particular, the water separator element 40 comprises a (single) conductive element 50 provided on the cartridge support, which conductive element 50 is firmly fixed to the water separator element 40 or is made integral with the water separator element 40, preferably this conductive element 50 is firmly fixed to the lower plate 443 of the hydrophobic mesh support 44 and/or to the lower plate 434 of the filtration membrane support 43 and/or to one of the longitudinal candles (inner longitudinal candle 441 or outer longitudinal candle 437).

In the example shown, the conductive element 50 is fixed to the hydrophobic mesh support 44, preferably to the lower plate 443 of the hydrophobic mesh support 44 itself, as described more clearly below.

However, it is not excluded to fix the conductive element 50 to the filtering septum support 43, preferably to the lower plate 434 of the filtering septum support 43.

The conductive element 50 is made entirely (i.e., all of its components) of a conductive material.

For example, in the first embodiment, the conductive member 50 is made of metal (e.g., steel (preferably, stainless steel), aluminum, or copper) or a metal alloy.

In the second embodiment, the conductive element 50 may be made of a conductive plastic (e.g., a conductive polymer and/or conductive composition material) or a metal (or metal alloy).

Thus, depending on the chemistry of the cartridge support and conductive element 50, different configurations of the water separator element 40 can be provided.

A first possible configuration may be that the cartridge support is made of an electrically insulating (dielectric) material.

Here, the conductive element 50 can be made of metal, for example fixed to the cartridge support (inserted or in some way connected to, or integrated in, or co-moulded with the cartridge support), or the conductive element 50 can be made of conductive plastic, for example integral with (for example by co-moulding) the cartridge support or fixed to (inserted or in some way connected or integrated in) the cartridge support itself.

A second possible configuration is for the cartridge support to be made of an electrically conductive material.

Here, both cartridge support and conductive element 50 can be made of the same material (or of the same class of materials).

For example, cartridge support and conductive element 50 can be made of a conductive plastic (e.g., the same conductive plastic or a different conductive plastic), or cartridge support and conductive element can be made of a metal (e.g., the same metal or a different metal).

Furthermore, the conductive element 50 can be formed integrally with the cartridge support, i.e. form a monolithic body, here.

Within the scope of the second configuration described above, cartridge support and conductive element 50 may also be made of different materials (or different classes of materials).

Here, the cartridge support may be made of conductive plastic or metal, and the conductive element 50 may be made of metal or conductive plastic.

Furthermore, here the conductive element 50 can be integrally formed with the cartridge support (e.g., by co-molding) or the conductive element 50 is fixed to the cartridge support (inserted or somehow connected or integrated).

As described more clearly below, the conductive element 50 is generally adapted to be electrically connected to the intermediate electrical contact 34 of the water level sensor 30 so that the water level sensor 30 extends (axially) towards the water collection chamber 26.

The conductive element 50 is defined by a (single-piece) body that is elongated along a longitudinal axis (mainly parallel to the longitudinal central axis B).

In practice, the conductive element 50 defines an extension of the intermediate electrical contact 34 of the water level sensor 30, and therefore of the electronic circuit of the water level sensor 30, which electrically interconnects the intermediate electrical contact 34 with the fluid (fuel or water) contained in the collection chamber 26.

Electrically conductive member 50 is positioned at an off-center location of the cartridge support relative to the longitudinal central axis B of the cartridge support.

The conductive element 50 is integrated in (or the conductive element 50 consists of) an elongated body made of conductive material, such as preferably a thin, narrow and elongated conductive strip or foil.

The conductive element 50 comprises a water level electrode 51, which water level electrode 51 is configured to extend directly into the collection chamber 26, i.e. to be introduced and arranged in the collection chamber 26.

By water level electrode is meant the surface of the conductive element 50, i.e. the surface of the conductive strip or foil forming the water level electrode, from which the cartridge support (plastic or plastic of which the cartridge support is made) emerges or protrudes, and which is adapted to be exposed, in use, to the fluid being filtered, i.e. to the fuel and/or water accumulated in the collection chamber 26, and to be in direct contact with the fuel and/or water accumulated in the collection chamber 26, so as to define a probe immersed in the fluid.

In practice, the water level electrode 51 is arranged in use (particularly when the water separator element 40 is properly inserted into the housing 20 and mounted on the water level sensor 30) within the collection chamber 26.

The water level electrode 51 is defined by a lower end portion of the conductive member 50 (or a lower end portion of the lower end of the conductive member 50, or a lower end portion of the region of the conductive member 50 near the bottom of the housing 20 when the water separator element 40 is inserted into the housing 20).

The water level electrode 51 is located at a surface position (substantially coplanar) of or protrudes from a lower surface (axially downward) of the cartridge support, and particularly, the water level electrode 51 is located at a surface position (substantially coplanar) of a lower plate 443 of the hydrophobic mesh support 44 and/or a lower surface of a lower plate 434 of the filter membrane support 43 and/or a surface position (substantially coplanar) of one of the longitudinal candles (inner candle 441 or outer candle 437), or the water level electrode 51 protrudes from a lower surface of a lower plate 443 of the hydrophobic mesh support 44 and/or a lower surface of a lower plate 434 of the filter membrane support 43 and/or one of the longitudinal candles (inner candle 441 or outer candle 437) (axially downward).

In the illustrated example, the water level electrode 51 protrudes (axially downward) from the lower surface of the lower plate 443 of the hydrophobic net support 44.

Preferably, the water level electrode 51 passes axially downwards through the lower end of the filter element, i.e. the lower end of the filter membrane 41 (and the hydrophobic net 42), by an axial extension of length unequal to zero and actually extends the water separator element 40 downwards.

When the water separator element 40 is disposed in the housing 20 (in the correct installed position of the water separator element 40), the water level electrode 51 (i.e., the free lower end of the water level electrode 51, the

longitudinal candle

441 or 437 derived therefrom from the

lower plate

443 or 434 furthest from the cartridge or body or the water level electrode 51) is disposed at a predetermined distance (non-zero) from the bottom of the cup-shaped body 21, wherein the predetermined distance is substantially equal to (except for axial tolerances due to interconnection) the predetermined distance of the electrical water level contact 33 from the bottom of the cup-shaped body 21.

The upper end of the water level electrode 51 is bound or connected to the body from which it is derived, the water level electrode 51 being arranged at a distance from the bottom which is larger than said predetermined distance, for example larger than the predetermined distance from the bottom of the cup-shaped body 21, the upper end of the electric water level contact 33 being located at the cup-shaped body 21.

In practice, the water level electrode 51 extends longitudinally between said upper end (constrained and connected to the body from which it is derived, in this example the lower plate 443 of the hydrophobic net support 44) and said free lower end, for example along a substantially rectilinear longitudinal extension (which is therefore parallel to the longitudinal axis a of the water level sensor 30) parallel to (and separated from) the longitudinal central axis B of the filter cartridge.

The axial length of the water level electrode 51 is, for example, greater than the axial length of the electric water level contact 33 of the water level sensor 30 (or the portion of the electric water level contact 33 axially exposed from the rod 31), preferably equal to the sum of the axial length of the projecting portion (at the bottom of the lower plate 443) of the free end of the rod 31 passing through the opening 444 (i.e., the free end of the closing cap 311) and the axial length of the electric water level contact 33 (i.e., the axial length of the axial exposure of the electric water level contact 33 from the rod 31).

The conductive member 50 includes a contact electrode 52, the contact electrode 52 being distant (i.e., located at a different axial and/or radial position) from the water level electrode 51, and being electrically connected to the water level electrode 51.

By contact electrode is meant the surface of the conductive element 50 (i.e. the surface of the conductive strip or foil forming the conductive element 50) from which the cartridge support is exposed or protruding (plastic or material of which the cartridge support is made) adapted to be placed in (forced) contact with the intermediate electrical contact 34 of the water level sensor 30 in use, thereby creating a direct electrical contact between the two adapted for the passage of an electrical current.

Thus, by means of the electrical connection (better described below) connecting the contact electrode 52 to the water level sensor 51, in practice the contact electrode 52 is intended to be in direct electrical contact with the intermediate electrical contact 34 of the water level sensor 30 by making the intermediate electrical contact 34 of the water level sensor 30 in electrical contact with the water level electrode 51 of the water separator element 40.

In the example shown, the contact electrode 52 is arranged (directly) in a cylindrical space delimited by the filter cartridge, preferably in an inner cylindrical chamber (in direct communication with the outlet duct 24) surrounded by the hydrophobic mesh 42.

In practice, when the water separator element 40 is (suitably) inserted into the housing 20, the contact electrode 52 is arranged inside the second environment (clean side) communicating with the outlet conduit 24, wherein the internal volume of the housing 20 is separated from the water separator element 40 (preferably, but not limited to, the volume of the housing 20 is located downstream of the hydrophobic mesh 42 in the direction of passage of the fuel from the inlet conduit 23 to the outlet conduit 24).

The contact electrode 52 is defined by an upper end portion of the conductive element 50 (or an upper end portion of the upper end of the conductive element 50, or a lower end portion of the region of the conductive element 50 remote from the bottom of the housing 20 when the water separator element 40 is inserted into the housing 20).

The contact electrode 52 is located in a surface position (substantially coplanar) or protrudes from the upper surface of the cartridge support (axially upward), in particular, the contact electrode 52 is located on the upper surface of the lower plate 443 of the hydrophobic mesh support 44 and/or the upper surface of the lower plate 434 of the filtration membrane support 43 (substantially coplanar), or the contact electrode 52 protrudes from the upper surface of the lower plate 443 of the hydrophobic mesh support 44 and/or the upper surface of the lower plate 434 of the filtration membrane support 43 (axially upward).

In the example shown, the contact electrode 52 protrudes from the upper surface of the lower plate 443 of the hydrophobic mesh support 44 (axially upward).

Preferably, the contact electrode 52 is arranged in the filter cartridge, i.e. in the hydrophobic mesh 42, in particular the contact electrode 52 is arranged in an axial region axially comprised between the lower end of the filter cartridge, i.e. the filtration membrane 41 (and the hydrophobic mesh 42), and the upper end of the filter cartridge.

For example, the contact electrode 52 (i.e. the free upper end of the contact electrode 52, which is the end furthest from the lower plate or the body from which it is derived) is arranged at a position at a predetermined distance (non-zero) from the lower plate from which the contact electrode 52 is derived (i.e. from the lower plate 443 of the hydrophobic net support 44), wherein the predetermined distance is substantially equal (apart from axial tolerances due to the interconnection) to the distance of the intermediate electrical contact 34 from the lower plate itself (from the lower plate 443 of the hydrophobic net support 44) when the water level sensor 30 is axially inserted (abutted) into the through opening 444.

In practice, the contact electrode 52 extends longitudinally between said free upper end to a lower end constrained and connected to a lower plate (or body) from which the lower end is derived, in this example the lower plate 443 of the hydrophobic mesh support 44, for example along an elongated longitudinal extension (which is therefore parallel to the longitudinal axis a of the water level sensor 30) substantially parallel to (and spaced from) the longitudinal central axis B of the filter cartridge.

The axial length of the contact electrode 52 is for example smaller than the axial distance between the intermediate electrical contact 34 and the electrical water level contact 33.

Preferably, at least the contact electrode 52 is elastically deformable.

That is, the conductive element 50 has a given deformability or elastic yield capability at least at the contact electrode 52.

In the example shown, the contact electrode 52 is oriented radially with respect to the longitudinal central axis B, i.e. is defined by a surface of the conductive element 50, which is oriented radially with respect to the longitudinal central axis B, preferably facing the inside of the filter cartridge, i.e. facing the longitudinal central axis B.

In practice, the contact electrode 52 is adapted to be arranged in the casing 20 in a position having the same axial height as the position in which the intermediate electrical contact 34 is located, and to be arranged radially (externally) side by side in a circumferential portion of the intermediate electrical contact 34, thus being in contact with the intermediate electrical contact 34 itself in a radial direction.

In this configuration, preferably, the contact electrode 52 is elastically deformable in a substantially radial direction.

In particular, the contact electrode 52 is configured such that, if subjected to a stress having a thrust force with a radial component (away from the longitudinal center axis B), a radial bending (away from the longitudinal center axis B) occurs, and an elastic reaction is exerted on the stress (i.e., a radial elastic thrust force is exerted toward the longitudinal center axis B).

In practice, the direct electrical contact between the (rigid) intermediate electrical contact 34 and the (elastically deformable) contact electrode 52 is of the forced type and therefore safer.

Advantageously, in the embodiment shown, the contact electrode 52 has a curved shape with a first radially outwardly inclined extension (away from the longitudinal central axis B) which projects close to the upper free end of the contact electrode itself.

The first extension defines an inclined ramp, for example a cam acting as a contact electrode 52, which, when stressed by a thrust directly axially towards the lower plate 443 and acting on the first inclined extension, is configured to bend the contact electrode 52 (substantially) radially away from the longitudinal central axis B.

This axial thrust is exerted, for example, by the water level sensor 30, i.e. by the intermediate electrical contacts 34 of the water level sensor 30, during the insertion (mutual approach) of the water level sensor 30 into the through-opening 444 of the water separator element 40.

In the example shown, the contact electrode 52 also has a second extension inclined radially inwards (towards the longitudinal central axis B), close to the constrained lower end of the contact electrode itself.

This second inclined extension is for example connected to the first inclined extension and defines between them a (circular or flat) edge that faces the longitudinal central axis B and in fact defines the contact electrode 52, i.e. the portion of the contact electrode 52 in direct contact with the intermediate electrical contact 34.

In an alternative embodiment not shown in the drawings, such as an alternative embodiment in which the intermediate electrical contact 34 is a downward-facing axial contact, the contact electrode 52 may accordingly be an upward-facing axial contact (i.e., the contact electrode 52 is oriented axially upward relative to the longitudinal center axis B); in other words, by the surface of the conductive element 50, which is substantially perpendicular to the longitudinal central axis B, preferably faces the upper end of the filtering cartridge (filtering septum 41 and/or hydrophobic net 42).

In practice, the contact electrode 52 is adapted to be arranged in the casing 20 in a position having the same axial height as the position in which the intermediate electrical contact 34 is located, and to be aligned with a circumferential portion (from the bottom) of the intermediate electrical contact 34, thus being in contact with the intermediate electrical contact 34 itself in a radial direction.

In this configuration, preferably, the contact electrode 52 is elastically deformable in the substantially axial direction.

In particular, the contact electrode 52 is configured such that, if subjected to a stress having a thrust force with an axial component (toward the lower plate from which the contact electrode 52 is derived), axial bending occurs (toward the lower plate from which the contact electrode 52 is derived), and an elastic reaction is applied to the stress (i.e., an axial elastic thrust force is applied away from the lower plate from which the contact electrode 52 is derived).

In this case, the contact electrode 52 may be defined by or comprise at least one turn of a coil spring, for example having an axis parallel to the longitudinal central axis B.

According to a preferred embodiment, the contact electrode 52 may have a circumferential width such that the arc of the circumference is less than 90 °, for example less than 15 °.

It is not excluded that the contact electrode 52 has a widened upper end portion adapted to enclose a larger circumferential portion of the intermediate electrical contact 34, as shown in fig. 5, which may be provided at a circumferential gap between the opposite connected (or not fully connected) ends of the folded strip defining the intermediate electrical contact 34 itself.

For example, the widened upper end portion of the contact electrode 52 may have a curved trajectory with its axis of curvature parallel to the longitudinal central axis B, and preferably has a given deformability so as to expand the curvature in an elastic manner so as to circumferentially surround the intermediate electrical contact 34 in a more efficient manner.

In this case, the contact electrode 52 may have at least two contact portions 52' and 52 "for defining two contact areas located at the level of the intermediate electrical contact 34 and covering any electrical discontinuity on the outer surface of the intermediate electrical contact 34 itself.

The contact electrode 52 may have an annular shape and have a circumferential width such that the arc of the circumference is greater than 90 °, for example equal to 360 ° (i.e. substantially annular).

As described above, the contact electrode 52 is electrically connected to the water level electrode 51.

Specifically, the conductive member 50 includes a bridge 53, and the bridge 53 electrically connects the contact electrode 52 and the water level electrode 51.

The electrical bridges 53 are firmly fixed (directly and in contact therewith) to the cartridge support, in particular to the hydrophobic mesh support 44 and/or to the filtering membrane support 43, in this example the electrical bridges 53 are firmly fixed to the hydrophobic mesh support 44.

In more detail, the bridge 53 is firmly fixed to the lower plate 443 of the hydrophobic mesh support 44 and/or to the lower plate 434 of the filtering membrane support 43, in this example the bridge 53 is firmly fixed to the lower plate 443 of the hydrophobic mesh support 44, in practice so as to axially pass through the lower plate 443 of the hydrophobic mesh support 44.

The bridge 53 extends at the bottom (at the lower surface of the lower plate 443 of the hydrophobic mesh support 44) (i.e. emerging from the water surface or from the surface at the water surface) where the bridge 53 is connected to the constrained upper end of the water level electrode 51, and the bridge 53 extends at the top (at the upper surface of the lower plate 443 of the hydrophobic mesh support 44) (or emerging from the surface at the water surface or at the surface at the water surface) where the bridge 53 is connected to the constrained lower end of the contact electrode 52.

Thus, the electrical bridge 53 is at least partially provided in the lower plate 443 of the hydrophobic mesh support 44 and/or of the filtering membrane support 43 integrated therein, for example by co-moulding the metal conductive element 50 with the plastic lower plate 443 of the hydrophobic mesh support 44 and/or with the lower plate of the filtering membrane support 43, or alternatively by forcedly inserting (interlocking or snap-in or otherwise) the electrical bridge 53 in a through seat, preferably with a through axis substantially parallel to the longitudinal central axis B, made in the lower plate 443 of the hydrophobic mesh support 44 itself.

The bridge 53 may be non-detachably fixed to the lower plate 443 of the hydrophobic net support 44 and/or the filtering membrane support 43, or alternatively, the bridge 53 may be detachably fixed.

Thus, the bridge 53 is axially interposed between the contact electrode 52 and the water level electrode 51, and each of them extends toward the other in the axial direction.

In the preferred embodiment shown, the bridge 53 is made integrally with the contact electrode 52 and/or the water level electrode 51; in practice, the conductive element 50 is defined by a single body (conductive strip or foil) comprising (or formed by) a contact electrode 52, a level electrode 51 and a bridge 53 (wherein the bridge 53 is axially interposed between the contact electrode 52 and the level electrode 51).

In an alternative embodiment, it is not excluded that the bridge 53 is defined by a separate body electrically connected to the contact electrode 52 and the water level electrode 51.

Further, the bridge 53 is made of the same conductive material (metal) as that of which the contact electrode 52 and the water level electrode 51 are made, or when the cartridge element support is made of a conductive material, the bridge 53 is made of the same conductive material (metal) as that of which the cartridge element support is made.

Alternatively, the bridge 53 may be made of a conductive material (metal) different from the conductive material (metal) of which the contact electrode 52 and the water level electrode 51 are made, for example, having a larger resistance.

In the example shown, the upper part of the bridge 53 emerging from the lower plate 443 of the hydrophobic mesh support 44 is shaped as a guide block for externally surrounding the connection between the bridge 53 and the lower plate 443 themselves, thus, for example, defining a substantially axial prismatic connection.

Furthermore, when the cartridge support is made of electrically conductive material, the electrical bridges 53 can be part of the cartridge support, i.e. the electrical bridges 53 are defined as one piece with the cartridge support.

Different and equivalent configurations of the fuel filter 10 may be provided in addition to those described above.

Moreover, unlike what is shown, an alternative embodiment (not shown in the figures) makes it possible to pass the filter cartridge radially from the inside outwards, so that the hydrophobic net 42 (if provided) is positioned outside the filtering septum 41.

Here, the inlet duct is the inlet from which the fuel to be filtered enters, defined by the above-mentioned central (or inner) duct which opens centrally into the casing 20 (i.e. into the cover 22), while the outlet duct, which is the above-mentioned peripheral (or outer) duct from which the filtered fuel exits, is the above-mentioned peripheral (or outer) duct which opens into the casing 20 (i.e. into the cover 22), into a peripheral region of the cover 22 (close to the side wall of the cover 22) or in any case in fluid communication with the environment interposed radially between the filter cartridge and the inner wall of the casing 20.

In this case, the fuel entering the casing 20 from the inlet conduit 23 passes (radially, from the inside outwards) through the water separator element 40, i.e. first through the filtering septum 41, then through the hydrophobic net 42, and then exits from the outlet conduit 24 (filtered and separated from the water accumulated in the collection chamber 26).

In this case, the through-openings 444 can be made in the lower plate 434 of the filter membrane support 43 and/or in the lower end region of the outer longitudinal candles 437 (if provided) coaxially associated with the filter membrane 41.

Furthermore, as mentioned above, (only) the conductive element 50 may (also) be provided on the lower plate 434 of the filter membrane support 43 and/or on the outer longitudinal candle 437 (if provided) coaxially associated with the filter membrane 41.

In view of the above, the fuel filter 10 operates as follows.

When the water separator element 40 is correctly inserted into the housing 20 and the housing 20 is closed, the water level sensor 30 (i.e. the stem 31 of the water level sensor 30) is axially inserted into the water separator element 40 so as to be surrounded by the filter cartridge, i.e. by the filter membrane 41 and/or the hydrophobic net 42.

Furthermore, the water level sensor 30, in particular the rod 31, is (at least partially) inserted into the through-opening 444 and (sealingly) abuts on a peripheral edge of the through-opening 444.

In this operating configuration, the electrical water level contact 33 of the water level sensor 30 is arranged directly in the collection chamber 26, while the intermediate electrical contact 34 of the water level sensor 30 is arranged outside the collection chamber 26 in the inner volume of the water separator element 40.

Furthermore, the contact electrode 52 of the water separator element 40 is in direct (forced) electrical contact with this intermediate electrical contact 34, and the water level electrode 51 of the water separator element 40 is arranged directly in the collection chamber 26.

In practice, the intermediate electrical contact 34 is arranged substantially indirectly in the collection chamber 26 by electrical insertion of the conductive element 50.

Thus, both the electrical water level contact 33 and the water level electrode 51 are exposed to the same fluid present in the collection chamber 26.

Since water has a greater conductivity than fuel oil (gas oil), if both the electric water level contact 33 and the water level electrode 51 are exposed to the fuel oil, the electric water level contact 33 and the water level electrode 51 are substantially isolated from each other by the fluid (fuel oil), and once the electronic circuit of the water level sensor is powered, the water level sensor measures a first current intensity value according to the resistance of the gas oil located in the circuit defined by the electric water level contact 33 and the water level electrode 51.

If the water accumulated on the bottom of the casing 20 in the collection chamber 26 reaches a level such that the electric water level contacts 33 and the water level electrodes 51 are only partly involved, the electronic circuit measures a second current intensity value at the circuit end defined by the electric water level contacts 33 and the water level electrodes 51, depending on the resistance of the water, which is therefore greater than the first current intensity value, and accordingly signals the vehicle control unit that the water accumulated in the collection chamber needs to be drained through the drain conduit 25.

The invention thus conceived is susceptible of numerous modifications and variations, without thereby departing from the scope of the inventive concept.

Moreover, all the details may be replaced with other technically equivalent elements.

In practice, the materials used, as well as the specific shapes and dimensions, may vary according to requirements without thereby departing from the scope of protection of the accompanying claims.

Claims

1. A fuel filter (10) comprising:

a housing (20) having a collection chamber (26) at a bottom of the housing (20), the collection chamber (26) for collecting water separated from fuel oil;

a water level sensor (30) extending into the housing (20) and provided with electrical water level contacts (33) extending into the collection chamber (26) and intermediate electrical contacts (34) arranged within the housing (20) outside the collection chamber (26); and

a water separator element (40) housed in the housing (20), wherein the water separator element (40) comprises:

a filter element (41, 42) adapted to be crossed by the fuel;

a cartridge support (43, 44) provided with a through opening (444), said through opening (444) being crossed by said water level sensor (30) so that said electric water level contact (33) extends into said collection chamber (26); and

a conductive element (50) disposed on the cartridge support (43, 44), wherein the conductive element (50) is provided with:

a water level electrode (51) extending into the collection chamber (26); and

a contact electrode (52) electrically connected with the water level electrode (51) and distant from the water level electrode (51), wherein the contact electrode (52) is in contact with the intermediate electrical contact (34) of the water level sensor (30).

2. The fuel filter (10) of claim 1 wherein a sealed connection is defined between the water level sensor (30) and the through-opening (444).

3. The fuel filter (10) of claim 1, characterized in that the water level sensor (30) has a longitudinal extension along a longitudinal axis (a), the through opening (444) peripherally surrounding a connection portion (35) of the water level sensor (30) axially between the electrical water level contact (33) and the intermediate electrical contact (34).

4. The fuel filter (10) of claim 1,

the filter cartridge (41, 42) has a substantially tubular shape extending around a longitudinal central axis (B), the water level sensor (30) is axially inserted in the filter cartridge (41, 42), and

the cartridge support (43, 44) comprises a lower plate (434, 443), the lower plate (434, 443) being fixed to the lower end of the cartridge (41, 42) close to the collection chamber (26), the through opening (444) being made in the lower plate (434, 443).

5. The fuel filter (10) of claim 1, characterized in that the through-opening (444) is surrounded by a guide body (445) for the water level sensor (30).

6. The fuel filter (10) of claim 5 wherein the guide body (445) comprises a plurality of individual projections, one side of which is located on a common conical surface converging towards the through-opening (444).

7. The fuel filter (10) of claim 4 wherein the filter element comprises a filter membrane (41), the filter membrane (41) being for filtering particulate matter present in the fuel.

8. The fuel filter (10) of claim 4 wherein the filter element comprises a hydrophobic mesh (42), the hydrophobic mesh (42) for separating the water from the fuel.

9. The fuel filter (10) of claims 7 and 8, characterized in that the filter membrane (41) and the hydrophobic mesh (42) are coaxial to one another.

10. The fuel filter (10) of claim 1 wherein the contact electrode (52) is elastically deformable.

11. The fuel filter (10) of claim 10 wherein the filter element (41, 42) has a substantially tubular shape extending about a longitudinal central axis (B), the contact electrode (52) being radially oriented to the longitudinal central axis (B) and being elastically deformable in a substantially radial direction.

12. The fuel filter (10) of claim 1 wherein the contact electrode (52) and the water level electrode (51) are defined by two opposing free ends of a single elongated conductive element that is integrally formed.

13. An element (40) for a fuel filter (10) for separating water from fuel, the element (40) comprising: a housing (20) having a collection chamber (26) for collecting the water separated from the fuel oil; and a water level sensor (30) extending into the housing (20) and provided with electrical water level contacts (33) extending into the collection chamber (26) and intermediate electrical contacts (34) arranged inside the housing (20) outside the collection chamber (20); and wherein

The water separator element (40) comprises:

a filter element (41, 42) adapted to be crossed by the fuel;

a cartridge support (43, 44) provided with a through-opening (444), the through-opening (444) being adapted to be passed through by the water level sensor (30) of the fuel filter (10) such that the electric water level contact (41) extends through the cartridge (41, 42) into the collection chamber (26); and

a water level electrode (41) configured to extend into the collection chamber (26); and

a contact electrode (52) electrically connected with the water level electrode (51) and distant from the water level electrode (51), wherein the contact electrode (52) is configured to be in contact with the intermediate electrical contact (34) of the water level sensor (30) disposed outside the collection chamber (26).