TECHNICAL FIELD OF THE INVENTION

The present invention relates to a filtering device, for filtering a fluid flowing out of a fluid tank belonging to a motor vehicle. The present invention also relates to a fluid tank comprising such a filtering device. Furthermore, the present invention relates to a motor vehicle comprising such a fluid tank.

BACKGROUND OF THE INVENTION

A filtering device of the prior art usually comprises a fluid enclosure, within which is located a filter unit, like a porous cartridge. The fluid, for instance fuel, exhaust after-treatment fluid, or oil, flows into the fluid enclosure through an inlet port and flows out of the fluid enclosure through an outlet port. The fluid enclosure has an opening through which the filter unit can be removed in order to be replaced. The filtering device further comprises a cap adapted to reversibly close this opening. When replacing the filter unit, it is important to avoid any significant leak of fluid through this opening in order to keep the environment clean. Therefore, the opening and the cap of a prior art filtering device, like the one described by EP-A-0 233 696, are located on the top of the fluid enclosure.

However, such a top location of the cap makes it necessary to give the user an access to the cap by the top, i.e. to leave an empty space above the filtering device. Such an empty space is relatively cumbersome for the fluid tank and/or for the motor vehicle. Besides, it might remain difficult to remove the filter unit through such an empty space. SUMMARY

One object of the present invention is to provide a filtering device which does not induce a cumbersome assembly of the fluid tank on the motor vehicle and which enables a clean and easy replacement of its filter unit, i.e. without any significant leak of fluid.

This object is achieved by a filtering device for filtering a fluid flowing out of a fluid tank for a motor vehicle, comprising: - a fluid enclosure having an opening;

- a filter unit at least partly located within said fluid enclosure, in order to filter said fluid, said filter unit being arranged to be removed through said opening;

- at least one inlet port arranged to be connected to said fluid tank and to an internal volume of said fluid enclosure, so as to allow said fluid to flow into said fluid enclosure;

- at least one outlet port located downstream of said internal volume of said fluid enclosure, in order to allow said fluid to flow out of said fluid enclosure;

- a cap adapted to be moved between a closed position and an open position so as to reversibly close said opening,

characterized in that said cap is located in the lower part of said fuel enclosure and in that said filtering device further comprises at least one inlet valve for controlling the flow of fluid through said inlet port and in that said inlet valve is adapted to close said inlet port when said cap reaches a first predetermined position when being moved from said closed position to said open position.

Such a filtering device, with a cap located on a lower part of its fluid enclosure, enables an access by a side or by the bottom of the filtering device, for replacing its filter unit without significant leak of fluid.

According to other advantageous but optional features of the present invention, considered on their own or in any technically possible combination:

- The filtering device further comprises a primary operating means adapted to move the inlet valve into a closing position of the inlet port when the cap reaches the first predetermined position.

- The first operating means comprises resilient means adapted to urge a part of the inlet valve against its seat.

- The inlet valve closes the inlet port under the action of gravity.

- The filtering device further comprises a secondary operating means adapted to open the inlet valve when said cap reaches a second predetermined position when being moved from its open position to its closed position.

- The second operating means comprises a thrust surface of the cap arranged to urge the part of said inlet valve away from its seat, against the primary means or against gravity, and in that the first predetermined position corresponds to said second predetermined position.

- The inlet valve has an I-shaped cross-section, one flange of which defines an abutment surface adapted to cooperate with the thrust surface.

- The outlet port is equipped with a check-valve.

- The fluid enclosure is defined by a housing having walls adapted to be secured to walls of the fluid tank.

- The fluid enclosure is adapted to be partly made by the walls of the fluid tank.

- Sealing means are arranged between said walls and said cap.

- The sealing means comprise a thread, at least one shoulder on the cap and/or at least one O-ring.

- The outlet port is located into said walls.

- The outlet port is located on top of the fluid enclosure.

- The outlet port is located in the cap.

- The inlet port is arranged above the level of the opening of the fuel enclosure.

- The cap lies at the bottom of the fluid enclosure when it is in its closed position.

Another object of the present invention is to provide a fluid tank which enables an easier access to the filtering device and which does not require an empty space on top of it, in the motor vehicle. This object is achieved by a fluid tank comprising at least one filtering device as mentioned here-above.

A further object of the present invention is to provide a motor vehicle which enables an easier access to its filtering device without requiring any empty space above its fluid tank. This object is achieved by a motor vehicle comprising at least one fluid tank as mentioned here-above.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention and its advantages will be well understood on the basis of the following description, which is given as an illustrative example, without restricting the scope of the invention, in relation with the annexed drawings, among which: - figure 1 is a schematic cross-section of a filtering device and a part of a fluid tank according to a first embodiment of the invention,

- figure 2 is a schematic cross-section of a filtering device and a part of a fluid tank according to a second embodiment of the invention, and - figure 3 is a schematic cross-section of a filtering device and a part of a fluid tank according to a third embodiment of the invention.

DETAILED DESCRIPTION OF SOME EMBODIMENTS

Figure 1 illustrates a filtering device 100, which comprises a fluid enclosure 102 defined by a housing 101. Filtering device 100 is specifically designed for filtering fuel flowing out of a fuel tank T whose lower wall 190 is partly shown, and into a fuel supply system belonging to a motor vehicle (not shown). The invention is applicable with any liquid tank, for example an exhaust after- treatment fluid tank, or an oil tank.

The walls of housing 101 define an opening 104 of fluid enclosure 102.

Housing 101 is adapted to be secured in an opening 192 of wall 190. The walls of housing 101 can be secured to wall 190 by any known means, preferably in a detachable manner.

According to a non represented embodiment, housing 101 and wall 190 can be made in one piece.

Filtering device 100 also comprises a filter unit 103, which is completely located, i.e. fully encased, within fuel enclosure 102. Filter unit 103 is adapted to operate a filtration of the fuel, i.e. to separate and remove impurities, like water or solid matter, from fuel flowing through it. Filter unit 103 can be made of a porous cartridge in the shape of a cylinder with a circular basis. Alternatively, other shapes can be considered for filter unit 103.

Filter unit 103 is arranged to be easily removed through opening 104. The overall dimensions of filter unit 103, in particular its diameter D103, or its largest dimension if not a cylinder, are selected to this aim. In particular, diameter D ₁₀ 3 of filter unit 103 is smaller than the width W104 of opening 104. Thus, a user can remove and replace filter unit 103 through opening 104.

Furthermore, filtering device 100 has an inlet port 110 and an outlet port 120. Inlet port 110 is connected to the inside volume of fuel tank T and is located upstream of the internal volume V102 of fuel enclosure 102. Inlet port 110 allows fuel to flow from fuel tank T into fuel enclosure 102. Inlet port 110 is connected to fuel tank 1 by means of an inlet line 111 , made for instance of a flexible hose. Inlet port 100 can be arranged above the opening 104 of the fuel enclosure 102.

Outlet port 120 is located downstream of volume V102 of fuel enclosure 102. Outlet port 120 allows fuel to flow out of fuel enclosure 102 towards a fuel supply system belonging to the motor vehicle according to the invention. As known per se and hence not shown on the drawings, such a fuel supply system has a fuel supply pump adapted to move fuel. Outlet port 120 is connected to the fuel supply system by means of an outlet line 121 , made for instance of a flexible hose.

Alternatively, inlet and outlet lines 11 1 and 121 can be made of rigid tubes. The terms "connected" and "connection" are to be construed herein as a link that enables the fluid, whether gas or liquid, to flow or circulate between two or more points or parts; such a link can be direct or made of a duct, of a pipe, etc. The terms "upstream" and "downstream" herein refer to the general direction of flow of fuel in the filtering device.

In this first embodiment, outlet port 120 is located on top of fuel enclosure 102, directly downstream of filter unit 103. A check-valve 150 may be arranged between filter unit 103 and outlet port 120, in order to let fuel flow out of fuel enclosure 102 and to prevent the fuel contained in outlet line 121 from flowing back into fuel enclosure 102.

Filter unit 103 may comprise an annular groove 1038 equipped with an O- ring 1037. O-ring 1037 bears against outlet port 120 in order to seal the top of filter unit 103 with respect to fuel possibly contained in the upper part of fuel enclosure 102. Alternative sealing means can be considered, especially when cap 130 and wall 101 are not of circular cross sections.

Filtering device 100 further comprises a cap 130 which is located in the lower part of fuel enclosure 102 and lower than inlet port 110. Cap 130 can be moved between a closed position, as illustrated on figure 1 , and an open position (not shown) where cap 130 is removed from opening 104 so as to allow removal of filter unit. In the shown example, the main part of cap 130 is a disc area whose dimensions approximately correspond to the dimensions of opening 104, in particular to width W104. This disc area of cap 130 can thus cover or close opening 104. Thus, cap 130 is adapted to reversibly close opening 104. An annular skirt 131 stands on this disk area, so as to extend into the lower part of fuel enclosure 102 and close to the walls of housing 101. A purge valve 181 may be mounted on the disk area of cap 130. The terms "lower" and "higher" herein refer to the relative position of components when the motor vehicle is in operation.

In this embodiment, cap 130 lies at the very bottom of fuel enclosure 102. Thus, when cap 130 is in its open position, i.e. removed, it enables a user to access fuel enclosure 102 and filter unit 103 from under fuel tank T. Alternatively, cap 130 could be located on a side of the fuel enclosure, provided that it is located in the lower part of such a fuel enclosure. Such a location of the cap would enable a user access to the filtering device by a side, hence still from under the fuel tank of the motor vehicle.

On the drawings, the flow of fuel through the filtering device is schematically shown by curved arrows. Along filtering device 100, fuel flows through inlet port 110 then into the cavity defined by annular skirt 131 , then upwards between filter unit 103 and the inner walls of housing 101. Filtration of fuel then occurs when it flows laterally into filter unit 103. Thereafter, fuel flows upwards into filter unit 103 and through outlet valve 150 into outlet line 121.

Filtering device 100 further comprises an inlet valve 140 for controlling the flow of fuel through inlet port 1 10. Hence, inlet valve 140 is connected downstream of inlet line 111 and upstream internal volume V102 of fuel enclosure 102. As can be seen on figure 1 , where inlet valve 140 is open, fuel can flow through a hole 112 made into a wall 113 of housing 101. Hole 112 is located in an approximately horizontal area, by reference to the motor vehicle being in operation. In the shown embodiment, inlet valve 140 has a cross-section similar to the cross-section of I- beam, with a web 144, an upper flange 143 and a lower flange 145. Upper flange 143 and lower flange 145 extend horizontally while web 144 extends vertically between them. Upper flange 143 acts as a closing member when it bears against the seat of valve 140 made by the portion of wall 113 surrounding hole 112.

Filtering device 100 further comprises a helical spring acting as a resilient means adapted to urge inlet valve 140 towards a closed configuration, i.e. to urge upper flange 143 against wall 113. Helical spring 141 is arranged between wall 113 and lower flange 145, so as to work as a compression spring.

Cap 130 comprises a thread 135 on the external side of its annular skirt 131. A corresponding thread 105 is provided internally in the lower part of the walls of housing 101. Thus, cap 130 can be screwed on the walls of housing 101. For the sake of clarity, cap 130 has been illustrated with dimensions slightly smaller than its real dimensions. In other words, the real distance between cap 130 and the walls of housing 101 , at the levels of threads 105 and 135, is smaller than the emphasized distance shown on figure 1.

Annular skirt 131 may have has a shoulder 136 at the distal end of thread

135. Analogously, the lower part of the walls of housing 101 may have a shoulder 106, provided at the end of thread 105. Shoulders 106 and 136 may be adapted to cooperate, i.e. press the one against the other, when cap 130 is in its closed position. Shoulders 106 and 136 together form sealing means arranged between cap 130 and the walls of housing 101 , in order to prevent any significant leak by the bottom of fuel enclosure 102.

Besides, a groove 138 may be provided on annular ring 131 to accommodate an O-ring 137. O-ring 137, which is optional, bears against the inner wall of housing 101 when cap 130 is in its closed position. O-ring 137 thus forms another possible sealing means arranged between cap 130 and the walls of housing 101 , in order to prevent fuel leaks by the bottom of fuel enclosure 102.

When cap 130 is in its closed position, it is directly or indirectly in contact with inlet valve 140. In this embodiment, cap 130 has a thrust surface 134, which is located at the distal end of annular skirt 131 , i.e. opposite the disc area of cap 130, and which can come into contact with an abutment surface 142 formed by the lower face of lower flange 145. Helical spring 141 hence urges abutment surface 142 against thrust surface 134. Inlet valve 140 thus follows cap 130, when cap 130 is being unscrewed.

When a user keeps on unscrewing cap 130, the latter reaches a first predetermined position where upper flange 143 bears against the seat formed by wall 113, thus preventing inlet valve 140 from further following cap 130. Helical spring 141 therefore forms a first operating means adapted to close inlet valve 140 when cap 130 is in a first predetermined position. Such a first predetermined position represents an intermediate position, for it lies between the closed position and the open position of cap 130.

This first predetermined position can be reached by unscrewing only partially cap 130, say by a predetermined number of turns. Such a first predetermined position ensures that inlet valve 140 will be shut long before the sealing means, like O-ring 137, shoulder 136 and thread 135, loose contact with the inner walls of housing 101. This avoids any significant leak of fuel.

When cap 130 has reached its first predetermined position, volume V ₁₀ 2 is no more in fluid communication with tank T and it is possible to empty this volume via purge valve 181.

When the user further unscrews cap 130 and eventually removes it from filtering device 100, inlet valve 140 remains closed, thus preventing any significantly leak of fuel out of fuel tank 190 and through inlet port 110. When cap 130 is removed, filtering device 100 enables an easy access to volume V ₀ 2 of fuel enclosure 102 and, in particular, to filter unit 103. Filter unit 103 is attached to cap 130 by means of a shaft 133, albeit it could alternatively be attached to the housing of the filtering device. Hence, when the user removes cap 130, he also removes filter unit 103 and he can subsequently detach filter unit 103 and replace it by a clean filter unit.

On the other way round, when the user screws cap 130, assembled with filter unit 103, onto the walls of housing 101, cap 130 reaches a second predetermined position where thrust surface 134 reaches abutment surface 142, i.e. where cap 130 comes in contact with inlet valve 140. Such a second predetermined position also represents an intermediate position, for it lies between the closed position and the open position of cap 130.

When the user keeps on screwing cap 130, thrust surface 134 urges upper flange 143 away from seat 113 against helical spring 141. Thrust surface 134 forms a second operating means adapted to open inlet valve 140 when cap 130 reaches this second predetermined position, thus starting to open inlet valve 140. In the embodiment illustrated on figure 1 , the first predetermined position, where inlet valve 140 is closed, corresponds to the second predetermined position, where inlet valve 140 starts to open. As soon as inlet valve 140 starts to open, i.e. as soon as upper flange 143 leaves walls 113, fuel can flow from inlet port 110 to volume V102 of fuel enclosure 102, through hole 112.

Figure 2 illustrates a filtering device 200 according to another embodiment of the present invention. In most cases, the reference number of a part of filtering device 200 can be directly derived, by adding 100 to it, from the reference number of the corresponding part of filtering device 100 at figure 1.

One can thus define a fuel enclosure 202 with an internal volume V202. a filter unit 203, an opening 204, a thread 205, a shoulder 206, an inlet port 210, an inlet line 211 , an outlet port 220, an outlet line 221 , a cap 230, an annular skirt 231 , a shaft 233, a thrust surface 234, a thread 235, a shoulder 236, an inlet valve 240, a spring 241 , an abutment surface 242, an upper flange 243, a web 244, a lower flange 245, an outlet valve 250, a purge valve 281 and a fuel tank wall 290 of a tank T. The description of all these parts of filtering device 200, whether structural or functional, can easily be derived from the description of the corresponding parts of filtering device 00 here-above given with respect to figure 1 , with the exception of the differences here-under described.

Filtering device 200 mainly differs from filtering device 100 by the fact that fuel enclosure 202 is partly made by a wall 290 of fuel tank T, instead by the walls of specific housing 101. Outlet port 220 is still located at the top of fuel enclosure 202, as in filtering device 100, but it is connected to the walls 290 of fuel tank T, instead of the walls of housing 101 for filtering device 100.

Besides, cap 230 differs from cap 130 by the fact that it comprises a sensor 283. This sensor 283 is used, for example, for fluid quality evaluation, water in fuel detection or temperature measurement. Sensor 283 can be used for other purposes. Inlet port 210 differs from inlet port 110 by the fact that it comprises a filter 212, in order to stop most of solid particles flowing within fuel. Shaft 233 fulfils the same functions as shaft 133. These shafts can be dismountable and available in different length to accommodate different filter size, if needed. Besides, fuel tank wall 290 comprises a valve 282 which has the following function: when a new filter is re-mounted, the volume V202 is full of air. When the valve 244 opens, the liquid can come in but the air should be purged somewhere. The valve 282 allows the air in the fuel enclosure to be purged, for example towards the top of the tank. It can be provided that valve 282 does not allow fuel to escape from the fuel enclosure, for example with the use of a floating ball. As a result, if the tank is full enough, the filter air purge is automatic. Fuel tank 290 may also comprise a piston 284 that can be manually operated as a hand pump. If the tank is not full enough the automatic filter air purge cannot work. The hand pump 284 can allow someone to do it. Moreover if the circuit needs to be purged, the hand pump 284 offers the possibility to get it done.

Figure 3 illustrates a filtering device 300 according to another embodiment of the present invention. In most cases, the reference number of a part of filtering device 300 can be directly derived, by adding 200 to it, from the reference number of the corresponding part of filtering device 100 at figure 1.

One can thus define a fuel enclosure 302 with an internal volume V ₃₀ 2, a filter unit 303, an opening 304, a thread 305, a shoulder 306, an inlet port 310, an inlet line 311 , an outlet port 320, an outlet line 321 , a cap 330, an annular skirt 331 , a shaft 333, a thrust surface 334, a thread 335, a shoulder 336, an inlet valve 340, a spring 341 , an abutment surface 342, an upper flange 343, a web 344, a lower flange 345, an outlet valve 350, a purge valve 381 and a fuel tank 390. The description of all these parts of filtering device 300, whether structural or functional, can easily be derived from the description of the corresponding parts of filtering device 100 here-above given with respect to figure 1 , with the exception of the differences here-under described.

Filtering device 300 mainly differs from filtering device 100 by the fact that its outlet port 320 is located into cap 330, instead of being located in the walls that define the fuel enclosures 102. Hence, outlet port 320 is located lower than inlet port 310, in the lower part of fuel enclosure 102 and more particularly at the bottom of fuel enclosure 302. Such a location of outlet port 320 provides an easier access to outlet valve 350 and to outlet line 321. Besides, shaft 333 is hollow, as a tube, whereas it can be solid for filtering device 100 or 200.

Along filtering device 300, fuel flows through inlet port 310 then into a cavity C ₃₃ i defined by annular skirt 331 of cap 330, then upwards in volume V ₃₀ 2 between filter unit 303 and the inner walls of fuel tank 390. Filtration of fuel then occurs when it flows laterally into filter unit 303. Thereafter, fuel flows downwards into filter unit 303, into hollow shaft 333 and through outlet valve 350 into outlet line 321. Like filtering device 200, filtering device 300 may also comprise a purge valve 381 a sensor 383, an exhaust valve 382 to decrease gaseous pressure within fuel enclosure 302 and a filter 312, at inlet port 310.

A filtering device 100, 200 or 300 according to the present invention enables an easy access to the fuel enclosure and, in particular, to the filter unit. Hence, this filter unit can be easily removed and replaced, for instance for maintenance operations. Moreover, the removal and the replacement of the filter unit does not induce pollution of the environment, since the first operating means are adapted to close the inlet valve when the cap has started to move towards its open position.

Furthermore, a filtering device according to the present invention does not require any empty space above it and above the fuel tank, due to this access by the bottom of the fuel enclosure. The bottom of a tank is, in most industrial vehicles, accessible. The top offers, most of the time, a limited access. This bottom access addresses as well the environmental concern of collecting the fluid to limit emissions and the cleanliness aspect of the filter re-mounting process to avoid dirt or external element introduction within the circuit after the filter element.

Moreover, a filtering device according to the present invention enables an efficient settling of fuel, to separate solid impurities and/or water from it, which is due to the fact that the filter unit is vertically oriented and to the fact that the fuel flowing through the outlet port does not come from the bottom of the fuel enclosure. Indeed, solid impurities and/or water are filtered by the filter unit and then "trapped" into the cavity defined by the annular skirt of the cap, whereas fuel may keep on flowing through the filter unit and the outlet port. This cavity can be easily cleaned outside the tank when the cap is removed.

Since first and second operating means are controlled by a displacement of the cap, the user does not need to shut any valve, because inlet valve will automatically close during unscrewing of the cap, thus avoiding any significant leak of fuel. Neither does the user need to empty the fuel tank before removing the cap and the filter unit, thus sparing a great amount of time.

Furthermore, when the filtering device object of the present invention is mounted on a fuel tank, the level of which is high enough, the filtering device will automatically be purged, because air will push the fuel out and the fuel will fill the fuel enclosure.

Other embodiments are also contemplated to be within the scope of the present invention. For instance, the first predetermined position of the cap can differ from the second predetermined position of the cap.

According to non represented embodiments of the invention, the spring 141 , 241 or 341 can be installed above the upper flange 143, 243 or 343 of the valve member, within the inlet 140, 240 or 340.

The filtering device object of the invention has been described for filtering fuel, albeit it may designed for other fluids used in a motor vehicle, like brake fluid, coolant, Diesel exhaust fluid, oil, etc ...

In the three embodiments of the invention described here-above, a spring 141 , 241 or 341 is used as a primary operating means which moves the inlet valve 140, 240 or 340 into its closing position. According to alternative embodiments of the invention, gravity can be used instead of a spring. In other words, the weight of the valve member is sufficient to close the valve when cap 130, 230 or 330 reaches its first predetermined position, when it is moved from its closed position to its open position.

Moreover, the invention has been represented with valve members having a plate like upper flange 143, 243 or 343. The invention can be implemented with valve members having another shape, e.g. a mushroom shape, a ball shape, etc....

According to alternative embodiments of the invention, the valve member can be provided with an upper stem adapted to cooperate with guiding means located above its upper flange. Moreover, the web 144, 244 or 344 of the valve member can have a non circular cross section, including a cross-like cross section.

According to still another embodiment of the invention, the valve member can be a ball housed within the valve inlet 140, 240 or 340 and a connecting link connects this ball with the cap. Alternatively, instead of a connecting link, magnets can be respectively fixed with the ball and the cap and their respective poles are arranged in such a way that they have a repulsive effect on each other, which allows to drive the ball with respect to its seat. According to a non-shown embodiment, instead of a helical spring, the first operating means can be made of any resilient material. The first operating means and/or the inlet valve itself can be integrally moulded with the housing 101.

Besides, the second operating means can be formed by a member of a mechanism distinct from the cap itself, but actuated by the cap. Indeed, one great advantage of the invention is that the inlet valve can de designed to be purely mechanically actuated, directly or indirectly, by the cap.

Besides, a filtering device and a fuel tank according to the invention are not limited to a specific motor vehicle. They can be mounted on a car, a truck, a motorcycle, etc ...