Patent ID: 12257535

DETAILED DESCRIPTION OF EXAMPLE EMBODIMENTS OF THE INVENTION

FIG.1shows a vehicle2, in particular a truck. This vehicle2includes an internal combustion engine, of which only the injection system20is shown in the figures. There is also a fuel tank4, a pre-filter6(optional), a main filter12and a low-pressure pump10, all of which form the internal combustion engine system shown in detail inFIG.2.

As shown inFIG.2, fuel tank4is connected to pre-filter6by a line8. Pre-filter6includes a tubular filter media that is passed through by the fuel from the outside to the inside. This means that the unfiltered fuel arrives in a chamber around the filter media, passes through the media and reaches the central chamber of the filter media. A pump10, called a low-pressure pump, draws fuel from the outlet of pre-filter6through a line14and delivers fuel to the inlet of the main filter12.

The fuel exits filter12through a line16that carries it to the engine's injection system20.

Advantageously, the injection system20includes what are called pump injectors, which draw fuel from the main filter to the injection system20, but alternatively, a pump, often called a high-pressure pump, could be used to transport fuel from filter12to the injection system20.

The system also includes a line22to discharge the amount of fuel that was not burned during combustion. In practice, it is a fuel-gas mixture that comes out of the engine's combustion cylinders. Also, a separation valve24separates the liquid from the gases: The liquid is sent to the suction line14of the low-pressure pump10, while the gases are returned to tank4.

As shown inFIG.3, Filter12consists of a filter housing30inside which a filter cartridge32is arranged. The filter housing30consists of a vessel34and a cover36that is detachably attached above the vessel34. Filter cartridge32may be better known as “filter element”. Also, the vessel34can be better known as the filter casing and the cover as the flange or filter head.

In practice, the cover36is screwed to the vessel34. Typically, cover36is fixed above vessel34. The vessel34can be unscrewed from the cover36from below, which makes it possible to remove the filter cartridge32and, if necessary, replace it.

Filter cartridge32includes a filter media38which has a tubular shape centered on an axis X38: Filter media38defines an internal volume V38. During operation, the filter media38is passed through by the fuel from outside to inside. This means that the unfiltered fuel arrives in a chamber around the filter media38, passes radially through the media38and reaches the internal volume V38of the filter media38, where it escapes through duct16to the engine's injection system20.

In the example, filter media38has a circular cross-section.

Filter cartridge32comprises a lower end plate40and an upper end plate42, comprising a liquid passage opening O42, which communicates with the inner volume V38of the filter media38. This means that, during operation, the filtered liquid contained inside the filter media38can escape upwards directly through the O42opening to duct16.

In the present document, and unless otherwise mentioned, the verb “communicate with” means that the communication is direct, i.e. that the two volumes that communicate with each other are not separated by any physical barrier. Typically, the inner volume V38of the filter media does not communicate directly with the outer volume of the media38because there is the media38forming a physical barrier in-between.

Advantageously, the outer diameter of the two end plates40and42is equal to that of the filter media38. Also, the inner diameter of the upper plate42is preferably identical to that of the filter media38.

The upper end plate42includes an automatic degassing valve50. “Automatic” means that valve50opens and closes automatically, without any manual action from an operator. Conversely, a purge screw, for example, is not an automatic degassing valve because purging is only done when the screw is manually removed.

In the example, valve50is offset from the central hole O42of the upper end plate42.

Advantageously, and as shown inFIG.4, valve50includes an upstream port, or inlet port O1and a downstream port, or outlet port O2, which faces upwards. As valve50is part of the upper end plate42, it is easy to understand that the downstream port (or orifice) is open on the side opposite the filter media38, as is the liquid passage opening O42. Precisely, the axis of the outlet hole, i.e. the downstream port O2, is substantially parallel to the central axis X38of the filter media38.

In this document, and in accordance with the common definition, a “port” or an “orifice” does not necessarily have to be interpreted as a hole of circular cross-section, it is more generally an opening, whatever its shape. In particular, the upstream port O1optionally takes the form of a slot, as shown inFIG.5.

Preferably, the upstream port O1and the downstream port O2are both open on the outside of the cartridge32. Otherwise formulated, the two orifices O1and O2are each not in communication with the inner volume of the filter cartridge32, i.e. they do not open into the volume V38of the filter media38. Specifically, the upstream port O1opens around the upper end plate42and the downstream port O2opens above the upper end plate42.

In the construction example in the figures, valve50comprises a gas discharge channel52and a closing member54which, as long as the channel is filled with gas, is held, for example by gravity, in an open position (shown inFIG.3) where it does not prevent the passage of gases through valve50and which rises by flotation (seeFIG.4) when channel52is filled with liquid, so as to close the valve in contact with a seat56. Also, the closing member54has a lower density than the fuel, so that it can float on the surface of the fuel.

In the example, the closing member54takes the form of a ball.

More generally, valve50remains open as long as the pressure difference between the upstream and downstream sides is less than or equal to a pressure threshold and closes automatically when the pressure difference exceeds said pressure threshold. This means that valve50can close while channel52is still filled with gas. In this case, the closing member54is not moved by the force of the liquid (Archimedes' thrust), but by the pressure of the gases. However, the pressure inside the filter housing30increases as it fills with liquid, in this case fuel. Thus, when valve50closes, it means that filter housing30is completely or almost completely filled with liquid.

In the example, valve50includes a valve body, or housing58, that protrudes upwards relative to the rest of the upper end plate. This means that valve body58protrudes from the side of plate42opposite the filter media38.

The seat56is part of the valve body58. This is a standard valve seat, so it is not useful to detail it further.

Advantageously, cover36has a hole60shaped to accommodate valve body58. This means that hole60is complementary to the shape of valve body58and allows a male-female fitting, valve body58being the male part and hole60the female part.

Preferably, the degassing valve50is arranged to allow the gas to return to the fuel tank4. Precisely, the hole60receiving the valve50is connected to a conduit18that carries the gases back to the fuel tank4. This means that during the degassing phase (valve50open), the gases inside the filter housing30are evacuated to the tank4.

A seal70(ring seal) is mounted around the valve body58to prevent liquid from passing around the body58.

InFIGS.2and3, the solid line arrows represent the passage of liquid in normal operation, while the dashed arrow represents the passage of gas.

Optionally, and as shown inFIG.6, valve body58has an outer surface of non-circular cross-section, the cross-sectional plane being parallel to the two end plates and therefore perpendicular to the central axis X38of the filter media38. Typically, this section can be polygonal, rectangular, etc. This makes it possible to perform mechanical coding, i.e. to avoid assembly errors, since it will not be possible to replace filter cartridge32with any other cartridge: the cartridge mounted for replacement must be identical to the one in place. In particular, if the cross-section of the valve body58is not complementary to the receiving hole delimited by the cover36, then it will not be possible to mount the new cartridge.

FIGS.7to10show a second embodiment the invention. In the following, and in order to avoid repetitions, only the differences relative to the first embodiment are described. Also, elements comparable or identical to those of the first embodiment are designated by the same numerical references, while new elements are designated by other numerical references.

In this second embodiment, the degassing valve50is still part of the upper plate42, but unlike the first embodiment, it is aligned (or positioned along) with the axis X38of the filter media38. Also, the degassing valve50is in direct communication with the internal volume V38of the filter media38, so that, if appropriate, the air present inside the volume V38can escape through the valve50.

In the example, valve50is formed at the top by a hollow cylinder58which protrudes upward, i.e. protrudes from the rest of the upper plate42of the filter cartridge. This cylinder58extends the central opening O42of the upper plate42upwards. The internal volume of cylinder58is therefore in direct communication with the internal volume V38of the filter media, so that the air and/or fuel in the centre of the media38can escape upwards towards cylinder58.

Cylinder58has a first opening62which extends at least partially radially through the thickness of cylinder58. In the example shown in the figures, the opening or aperture62is a radial hole with respect to the central axis of cylinder58and therefore also at the axis X38of filter media38since the two axes are confused. This opening62is a fuel outlet opening, especially for filtered fuel. It is connected to a conduit16whose function is to carry fuel to the engine cylinders.

Cleverly, unlike most filter cartridges where the fuel outlet is axially upward, the fact that fuel outlet port62is at least partially radial with respect to the filter media axis prevents, or at least makes it difficult to fill the cartridge through this port. Indeed, it has been found that some operators in garages tend, when changing filter cartridges, to empty the fuel contained inside the old filter cartridge into the inner volume of the new filter cartridge. However, the fuel transferred is often dirty (or unfiltered), so that after the filter cartridge has been replaced, the engine is likely to be started with dirty fuel, which is obviously not desirable. This is no longer possible, or at least more difficult with the filter cartridge according to the second embodiment of the invention because orifice62is less accessible. The radial positioning of hole62therefore discourages operators from attempting to empty fuel into the new cartridge.

Cylinder58has a second orifice O2, which is the degassing orifice, through which the air contained inside the cartridge can escape. The orifice O2is formed at the upper axial end of cylinder58, i.e. at the end opposite the annular part of the upper plate42.

The upper part of the cylinder58forms a valve body, and inside this valve body is housed a closing member54, which preferably takes the form of a ball. If there is no pressure or liquid inside the cylinder58, the closing member54rests on a plate74that is in one piece with the valve body, i.e. with the cylinder58. This plate74extends perpendicular to the axis of cylinder58and delimits at least one, preferably two openings76(which are obviously smaller than the closing member54), through which air and/or fuel can pass.

Basically, each opening76forms an inlet or upstream port of the degassing valve50, the outlet or downstream port being formed by the opening O2.

In the embodiment of the figures, the closing member54is held, for example by gravity and as long as the cylinder58is filled with gas, in an open position (shown inFIG.7) where it does not prevent the passage of gases through valve50.

The closing member54rises by flotation (seeFIG.9) when the cylinder58is filled with liquid, so as to close the valve in contact with a seat.

More generally, valve50remains open as long as the pressure difference between the upstream and downstream sides of the closing member54is less than or equal to a pressure threshold and closes automatically when the pressure difference exceeds said pressure threshold. This means that valve50can close while cylinder58is not entirely filled with liquid. In this case, the closing member54is not moved by the force of the liquid (Archimedes' thrust), but by the pressure of the gases. However, the pressure inside the filter housing30increases as it fills with liquid, in this case fuel. Thus, when valve50closes, it means that filter housing30is completely or almost completely filled with liquid.

Advantageously, the cover36has a hole60shaped to accommodate valve body58. This means that hole60is complementary to the shape of valve body58and allows a male-female fitting, valve body58being the male part and hole60the female part.

Also, the degassing valve50is preferably arranged to allow the gas to return to the fuel tank4. Precisely, the hole60receiving the valve50is connected to a conduit18that carries the gases back to the fuel tank4. This means that during the degassing phase (valve50open), the gases inside the filter housing30are evacuated to the tank4. In a variant not shown, the conduit18opens to the atmosphere.

A first seal70(ring seal) is mounted around the valve body58, between the opening42and the opening62, to prevent liquid from passing around the body58.

A second seal72(also a ring seal) is mounted around the valve body58, between the opening62and the opening O2, to prevent liquid from passing around the body58.

The conduit16includes a check valve (shown onFIG.7) that prevents the gases inside the cartridge to escape by conduit16. Indeed, the check valve only opens when the pressure upstream of it exceeds a certain threshold. Typically, when the filter cartridge is not filled with fuel, the pressure inside of it is not enough to open the check-valve and then the only way out for the gases is the degassing orifice O2.

When replacing the filter cartridge, if the operator forgets to install a new cartridge, then at least part of (if not all) the fuel arriving from conduit14will escape through conduit18and flow back to the reservoir. Then, it will be possible, for example thanks to a pressure sensor (not represented), to detect a pressure drop in the outlet conduit16and stop automatically the engine (“No filter no run”). Indeed, it will be possible to detect that the pressure in conduit16is not as high as it should be and then transmit the information to an ECU controlling the engine to stop the latter.

FIGS.11to14show a third embodiment of a filter cartridge according to the invention. In what follows, the features of the filter cartridge which are identical or similar to that of the filter cartridge according to the first or the second embodiment have the same numeral reference, while new features or distinct features have other numeral references. In addition, here below are mentioned only the differences with the first and the second embodiments: For concision purpose, the features of the third embodiment that are common to the first or the second embodiment are not described one more time.

As shown onFIG.11, the filter cartridge32according to the third embodiment is specific in that the top plate42is made out of two distinct parts42A and42B. Part42A is disc-shaped and is attached on top of the filter media38. Part42A has an outer diameter and an inner diameter which are identical to that of the filter media38. Part42B is a rotating ring, that is free to rotate relative to the part42A. The axis of rotation of the rotating ring42B is advantageously confounded with the central axis of the filter media (and of the part42A).

The parts42A and42B of the top plate are attached one with the other. In the example, the part42B is clipped on top of the part42A, meaning that the part42B is attached above part42A. Precisely, part42B includes a clip43, i.e. a flexible device for holding parts42A and42B together. In the mounted configuration, the clip43prevents the rotating ring42B from detaching. The clip43is a flexible ring-shaped portion, comprising an elbow-shaped tongue that partially overlaps the rotating ring42B to hold it in place.

In this embodiment, the top plate42also includes an automatic degassing valve50which belongs to the rotating ring42B.

In the example, valve50includes a valve body, or housing58(a.k.a “pin”), that protrudes upwards relative to the rest of the rotating ring42B. This means that valve body58protrudes from the side of part42B opposite the filter media38.

Advantageously, cover36has a hole60shaped to accommodate valve body58. This means that hole60is complementary to the shape of valve body58and allows a male-female fitting, valve body58being the male part and hole60the female part.

Preferably, the degassing valve50is arranged to allow the gas to return to the fuel tank4. Precisely, the hole60receiving the valve50is connected to a conduit18that carries the gases back to the fuel tank4. This means that during the degassing phase (valve50open), the gases inside the filter housing30are evacuated to the tank4.

A seal70(ring seal) is received inside an annular groove formed on the wall of the hole60. Seal70prevents liquid from passing around the body58. In a variant not shown, the seal ring70can be provided around the pin58.

The filter element32is received inside a filter shell (a.k.a “filter housing”)30. The filter housing30consists of a vessel34and a cover36that is detachably attached above the vessel34.

In practice, the cover36is screwed to the vessel34. Typically, cover36is fixed above vessel34. The vessel34can be unscrewed from the cover36from below, which makes it possible to remove the filter cartridge32and, if necessary, replace it.

In this embodiment, the vessel34and the cartridge32are secured one with the other, so that the cartridge32rotates conjointly with the vessel34when the latter is screwed around or inside the cover36. In other words, the cartridge32is not free to rotate relative to the vessel34. However, and since the part42B can rotate relative to part42A, the rotating ring42B can also rotate relative to the vessel34.

In practice, any appropriate fixing means can be used to secure the filter cartridge32inside the vessel34. Typically, a clipping means can be provided to secure the filter cartridge32inside the vessel34.

Since this fixing means is already known in itself, and widely used, it has not been detailed further.

Preferably, filter12according to this third embodiment is a “spin-on” fuel filter design which is to be unscrewed from its mount, discarded, and replaced with a new one. However, in an alternative embodiment, filter12can be of “cartridge” (or “replaceable element”) construction, in which the housing is a permanent housing that contains the replaceable filter element or cartridge.

In this embodiment, the cover36is specific in that it delimits a guiding surface100, which is in the form of an elliptic surface. The guiding surface is inclined relative to a plane perpendicular to the central axis of the filter12. In other words, the guiding surface corresponds to the intersection of a tube with a plane that is not perpendicular to the central axis of the tube (inclined plane).

The guiding surface100is designed for guiding the pin58towards the hole60when the assembly comprising the vessel34and the filter cartridge32is assembled at the bottom of the cover36.

Typically, when the filter cartridge32needs to be replaced, the operator proceeds firstly with dismounting it by unscrewing the vessel34from the top cover36. When the operator starts to unscrew the vessel34, the rotating ring42B remains immobile as the pin58is blocked in rotation because it is engaged in the receiving hole60. As soon as the pin58gets out of the hole60, it is no more blocked in rotation and moves along with the filter element32.

Afterwards, a new filter cartridge assembly is mounted below the cover: SeeFIG.11. The vessel34can be kept (“cartridge” design) or thrown away (“spin-on” design).

When the operator starts screwing the vessel34around or inside the top cover36, the pin58abuts against the guiding surface100of the cover36(there is no need to orient the pin58exactly in front of the hole60). Then, the screwing movement (which includes a rotation and a translation) forces the pin58to move along the guiding surface100.

The pin58can move in the same direction that the screwing motion, or in the opposite direction, depending on the location at which it abuts against the cover surface100. Typically, if the pin58is close to the hole60but that the screwing rotation motion tends to move the pin away from the hole60, then the inclined nature of the guiding surface100will prevent the pin58from moving in that direction and will force the pin58to move in the other direction and reach the hole60. This is made possible thanks to the fact that the rotating ring42B to which belongs the pin58can rotate relative to the rest of the filter element32. Then, the pin58can rotate in one direction even though the rest of the filter element32rotates in the other direction.

It is therefore to be understood that the pin58is automatically oriented towards its final position during the assembly operation, meaning that the operator does not have to orient the filter cartridge in a way that the pin58penetrates into the hole60.

When the pin58reaches the hole60, the rotating ring42B stops rotating. The filter cartridge (and the vessel34), however, keeps turning until screwing motion is complete. By pursuing the screwing movement, the pin58is pushed inside the hole60to reach the position ofFIG.14.

One advantage to this specific filter design is that if one tries to replace the filter cartridge32by a cartridge of a different design, then the hole60will not be plugged and all of the fuel will flow back to the reservoir4through line18. Accordingly, this special design ensures that the engine will not run if an inappropriate filter element (or if no filter) is assembled inside the housing30: This safety feature is called “No filter, No run”, as mentioned above.

When the pin58is engaged in the hole60, the degassing valve50works exactly like the one of the first and second embodiment (SeeFIGS.12and13). The valve50is open as long as the pressure upstream of the ball54is below a certain threshold (e.g. when the inlet conduit52is filled up with gas: SeeFIG.12) and automatically closes when the pressure exceeds such pressure threshold (e.g. when the inlet conduit52is filled up with fuel: SeeFIG.13).

In connection withFIG.14, when the filter element32is properly connected to the top cover36, Air or gas contained inside the housing30escapes through the degassing valve50and flows back to the reservoir. Precisely, the gas enters inside the pin58through orifice O1, flows through conduit52and escapes by orifice O2(SeeFIG.12, Arrow A4). Afterwards, the gas flows through conduit18back to the reservoir4.

In operation, unfiltered fuel arrives from conduit14to the outside volume of filter media38, as represented by arrow A1. Fuel flows then radially through the filter media38(As represented by arrow A2) and escapes through conduit16to the engine (As represented by arrow A3). In a variant not shown, the filter cartridge32ofFIG.3further includes a rotating ring that is attached to the top plate42. As its name indicates, this rotating ring would be capable of rotating relative to the top plate42. This rotating ring is secured in rotation with the vessel34. This rotating ring enables to create a degree of freedom of the assembly comprising the filter media38and the end plates40,42relative to the vessel34, meaning that the assembly formed by the filter media38and the end plates40,42can rotate relative to the vessel34(around axis X38). Accordingly, when the assembly formed by the vessel34and the cartridge32is assembled below the top cover36(e.g. when the vessel34is screwed to the cover36), the pin58first abuts against a guiding surface of the top cover36(similar to the embodiment ofFIG.11). Then, the pin58is first automatically driven in rotation (thanks to the guiding surface provided on the top cover36) to reach the receiving hole60arranged in the top cover36. As soon as the pin58penetrates into the hole60, the assembly formed by the filter media38and the end plates40,42stops rotating. By continuing to turn and push the vessel34upwards, this assembly is driven in translation by the screwing motion of the vessel34relative to the cover36to make the pin58fully penetrate inside the hole60and reach its final mounting position. This is exactly the same motion than that described in connection withFIG.11, that is why it is not detailed here once again.

In a variant not shown, the degassing valve50is located on the outside of the filter media38. In this case, the upper end plate42has a larger maximum diameter than the filter media38. Also, the upstream port O1opens below the upper end plate42.

According to another variant not shown, the closing member54is guided inside a vertical rail, for example of rectangular cross-section.

According to another variant not shown, the cylinder58comprises an outer thread and the hole60of the cover36comprises a complementary inner thread, so that the cylinder58of the filter cartridge may be secured to the cover36by these thread connection means.

According to another variant not shown, the cylinder58in not in one piece with the annular part of the upper end plate42but is secured to it by any suitable means (welding, gluing, etc.). More generally, in this paper, the fact that the degassing valve50“is part of” the upper end plate means that the two elements are secured one with the other, but do not necessarily form one piece.

It is to be understood that the present invention is not limited to the embodiment(s) described above and illustrated in the drawings; rather, the skilled person will recognize that many changes and modifications may be made within the scope of the appended claims.