SE1650445A1

SE1650445A1 - A fuel tank

Info

Publication number: SE1650445A1
Application number: SE1650445A
Authority: SE
Inventors: Amaechi Sydney
Original assignee: Scania Cv Ab
Priority date: 2016-04-04
Filing date: 2016-04-04
Publication date: 2017-10-05
Also published as: EP3439906A1; EP3439906A4; CN108883698A; KR20180121612A; WO2017176187A1; SE539790C2; BR112018068792A2

Abstract

16 Abstract A fuel tank for a wheeled motor vehicle comprises a container (3)configured to contain fuel, an insert (4) received in the containerand extending from an upper access hole (6) of the container forfilling the tank with fuel to a bottom region of the container and afuel feed conduit (16) having a fuel pick-up inlet (17) in the con-tainer for pumping fuel through the conduit to an engine of thevehicle. The fuel pick-up inlet is arranged inside the insert in thebottom region of the container. A float valve (18) is arranged witha valve body configured to close a connection of the fuel pick-upinlet of the conduit to the interior of the container through a filtercovering an opening in the bottom of the insert in a bottom positionof a float of the float valve and to open this connection when the float is lifted by fuel. (Pig 1).

Description

A fuel tank TECHNICAL FIELD OF THE INVENTION The present invention relates to a fuel tank for a wheeled motorvehicle comprising ø a container configured to contain fuel, o an insert received in the container and extending from anupper access hole of the container for filling the tank withfuel to a bottom region of the container, and ø a fuel feed conduit having a fuel pick-up inlet in said con-tainer for pumping fuel through the conduit to an engine of the vehicle.

The invention is not restricted to fuel tanks for any special type ofwheeled motor vehicles, although it is especially directed to heavymotor vehicles, such as buses and trucks, having large fuel tankswhich may contain 100 litre fuel or more when full, which is thereason why the invention will hereinafter mainly be discussed forthat application for illuminating the invention but not restricting it thereto.

Furthermore, the invention covers fuel tanks for containing anyconceivable fuel but is particularly directed to fuel tanks for con- taining fuel for compression ignited engines, such as diesel.

Due to the sensitivity of especially diesel engines to dirt and par-ticularly air in its fuel system said fuel pick-up inlet is mostly placed at a reasonable height above the bottom of the fuel tank container for ensuring that this inlet is always covered by fuel so that no airmay enter the fuel feed conduit irrespectively of the appearance ofthe ground on which the vehicle is standing. Such fuel tanks forheavy motor vehicles have a considerable volume and are oftenelongated in a direction in parallel with the ground on which a ve-hicle is standing, which means that a considerable volume of thefuel will not be available for use owing to the required height of theposition of said fuel pick-up inlet, i.e. the fuel tank will contain ahigh dead volume. This does in its turn mean that quite a reason-ably large amount of fuel is needed for the initial fill at the produc- tion line, which is tantamount to high cost for the manufacturer.

BACKGROUND ART US 2014/0075732 A1 discloses a fuel tank of the type defined inthe introduction having a said insert but in which the problem with a high said dead volume is still not solved.

SUMMARY OF THE INVENTION The object of the present invention is to provide a fuel tank of thetype defined in the introduction being improved in at least some aspect with respect to such fuel tanks already known.

This object is according to the invention obtained by providingsuch a fuel tank with the features listed in the characterizing part of appended patent claim 1.

By arranging a float valve to control the connection of the fuel pick- up inlet of the fuel feed conduit and a said fuel permeable filter to be passed by fuel for entering said fuel pick-up inlet this may bearranged in the bottom region of the container while still ensuringthat no dirt will enter the fuel feed conduit and in particular that noair will enter the fuel feed conduit irrespectively of the inclinationof said motor vehicle and by that of the fuel tank and how muchfuel is in said tank, since when there is not fuel present around thefloat of the float valve this will sink to said bottom position andclose the connection of the fuel pick-up inlet to the interior of thecontainer. This means that said volume of the fuel tank may bereduced considerably, and the amount of fuel needed for the initialfill at the production line will also be remarkably reduced savingcosts for the manufacturer. The reduced dead volume also meansthat the vehicle may be driven a longer distance after filling than before.

According to an embodiment of the invention the float valve is ar-ranged inside said insert and the bottom opening of the insert isconfigured to allow fuel to enter an insert volume surrounding saidfloat valve through the first fuel permeable filter. This means thatthe float valve may open said connection to the fuel feed conduitas long as there is fuel present on the bottom of the container in the region of said insert.

According to another embodiment ofthe invention the insert is pro-vided with a plurality of through-holes in walls thereof delimitingan inner volume of the insert with respect to a surrounding con-tainer volume and extending from said upper access hole to a bot-tom region of the container so as to allow fuel in the container toflow therethrough into the insert. The insert may by this be filled with fuel when present to a certain level in said container.

According to another embodiment of the invention constituting afurther development of the embodiment last mentioned the floatvalve is arranged inside the insert and a second fuel permeablefilter is arranged above the float valve so that this filter has to bepassed by fuel through influence of the gravitation for allowing fuelentering the insert through said through-holes to reach an insertvolume surrounding said float valve. lt is by that ensured that dirtin the fuel will not reach the float valve, since it has either to passthe first fuel permeable filter or the second permeable filter for reaching the float valve.

According to another embodiment of the invention the fuel tankcomprises a fuel reserve tank arranged inside said insert andopening upwardly towards said access hole of the container so asto be filled by fuel when filling the fuel tank with fuel through theaccess hole, the fuel reserve tank is provided with an overflowarrangement for overflow of fuel out into said container as of ob-tention of a certain level of the fuel inside the fuel reserve tankwhen filling the fuel tank by fuel, and a bottom region of the fuelreserve tank is provided with an outlet connected to said fuel feedconduit downstream said fuel pick-up inlet thereof through a valveconfigured to be closed as long as fuel is present in said conduitupstream thereof and to open upon occurrence of no fuel insidesaid conduit so as to drain fuel from the fuel reserve tank whenthis occurs. The combination of the arrangement of the fuel pick-up inlet in the bottom region of the container with a cooperationthereof with a float valve and the arrangement of said fuel reservetank will result in a possibility to reliably drive the vehicle without any risk of coming to an unintentional still standing even with a small amount of fuel left in the fuel tank, since fuel will be takenfrom the fuel reserve tank as soon as it will not be possible to takeit from the container through the fuel pick-up inlet and the fuelreserve tank will then also be filled to the level of said overflowarrangement. Thus, would a not neglectable amount of fuel still bepresent in the container of the fuel tank and the vehicle drive upor down a steep hill and the float valve will close fuel will shortlybe taken from the fuel reserve tank until the road flatten out and itwill be taken from the container again. This means that the vehiclemay reliably be driven as long as there is fuel in the fuel reservetank and accordingly to a point with a very small amount of fuel left in the fuel tank.

According to another embodiment of the invention said valve in theconnection of the fuel reserve tank to the fuel feed conduit is apressure release valve configured to open upon occurrence of anegative pressure inside said conduit. The arrangement of a pres-sure release valve to control draining of fuel from the fuel reservetank when there is no fuel around the float of the float valve con-stitutes a simple and reliable way of realizing such draining when there is a need to do that.

According to another embodiment of the invention the fuel tank isprovided with means configured to indicate the amount of fuel inthe fuel tank, and these means comprise a member measuring thelevel to which the fuel reserve tank is filled. The emptying of thefuel reserve tank will principally be started when there is no fuelleft in the container, and the member measuring the level of thefuel in the fuel reserve tank will by that indicate the amount of fuel left in the fuel tank with a high accuracy, so that the driver of the vehicle knows how far the vehicle may be driven without any risk of running out of fuel.

According to another embodiment of the invention said insert isconfigured to receive a fuel return line entering the fuel tankthrough said upper access hole of the container to direct fuel fromsaid fuel return line to enter the fuel reserve tank. lt is by thisensured that the fuel reserve tank is kept filled until the moment when nearly no fuel is left in the container of the fuel tank.

According to another embodiment of the invention the fuel tankcomprises a member configured to removably secure said insertto the container in the region of said access hole, and the insertand said access hole are designed so as to allow the insert to beremoved from the fuel tank through said access hole. This meansthat the insert may be removed from the fuel tank for repair ormaintenance or exchange thereof increasing the service ability ofthe fuel tank. Furthermore, this type of securing of the insertavoids welds, so that fastening of the insert may be accomplishedby means making it possible to produce the insert by light materi- als.

According to another embodiment of the invention the fuel tank isconfigured to be connected to a compression ignited engine andto contain for example diesel as fuel. The fuel tank according tothe invention is particularly suitable for use in fuel systems of suchengines being very sensitive to penetrating of air into the fuel sys- tem.

According to another embodiment of the invention the fuel tankhas a volume making it able to contain more than 100 |itre fuel andit is configured to be arranged in a heavy wheeled motor vehicle,such as a truck or a bus. A fuel tank designed in accordance withthe present invention may in such an embodiment reduce the dead volume with respect to known such fuel tanks considerably.

According to another embodiment of the invention said containerhas a dimension reaching and exceeding 300mm, 500mm, 1 000mm, 1 500 mm or 1 800 mm in a direction configured to be hori-zontal when said vehicle is arranged on a horizontal ground. A fueltank with such an extension will require a substantial amount offuel in the fuel tank for ensuring that at least half of the bottomthereof is covered by fuel when the vehicle is standing on a steeproad, so that a said dead volume may be reduced considerably by such a fuel tank designed according to the present invention.

The invention also relates to a wheeled motor vehicle provided with a fuel tank according to the invention.

Further advantages as well as advantageous features of the in- vention will appear from the description following below.

BRIEF DESCRIPTION OF THE DRAWING With reference to the appended drawing, below follows a specific description of an embodiment of the invention cited as an example. ln the drawing: Fig 1 is a schematic view illustrating a fuel tank according toan embodiment of the invention, andFig 2 is an enlarged view of a float valve arranged in the fuel tank shown in Fig 1.

DETAILED DESCRIPTION OF AN EMBODIMENT OF THEINVENTION Fig 1 illustrates schematically a fuel tank 1 for a wheeled motorvehicle 2 according to an embodiment of the invention. The fueltank comprises a container 3 configured to provide the main vol-ume for fuel of the fuel tank and an insert 4 removably secured bya securing member 5 to the container 3 at an access hole 6 of thecontainer for filling the tank with fuel for inserting the insertthrough this access hole 6 and remove it from the containerthrough that hole.

The insert 4 extends when secured to the container from the upperaccess hole 6 to a bottom region 7 of the container. The insert isprovided with a plurality of through-holes 8 in walls 9 thereof de-limiting an inner volume 10 of the insert with respect to a surround-ing container volume 11 and extending from the upper accessholes 6 to a bottom region of the container so as to allow fuel in the container to flow through these holes 8 into the insert.

The insert has a bottom 12 to be arranged next to the bottom 13of the container and which is provided with an opening 14 coveredby a first fuel permeable filter 15 to let fuel entering the insert from below through that filter.

A fuel feed conduit 16 for feeding fuel to an engine of the vehiclehas a fuel pick-up inlet 17 located inside the insert in the bottomregion thereof. This inlet 17 is connected to a float valve 18 (seenow also Fig 2) having a float 19 to be lifted by fuel surrounding itinside the insert so as to lift a valve body 20 and opening a con-nection of the fuel pick-up inlet 17 to said filter 15 for enabling fuelto pass through said filter and into the fuel conduit. When there isno fuel lifting the float 19 this and the valve body 20 will assume abottom position in which the valve body 20 is closing the connec-tion of the fuel pick-up inlet 17 to the interior of the containerthrough the filter 15.

A second fuel permeable filter 30 is arranged above the float valve18 so that this filter has to be passed by fuel through influence ofthe gravitation for allowing fuel entering the insert through theholes 8 to reach an insert volume surrounding the float valve. Thissecond fuel permeable filter is arranged at a lower level than the lowermost of said through-holes 8.

A fuel reserve tank 21, which may for instance have a volume of15 -100litre depending on the container volume, is arranged in-side the insert 4 and opens upwardly towards the access hole 6 ofthe container so as to be filled by fuel when filling the fuel tankwith fuel. The fuel reserve tank is provided with an overflow ar-rangement 22 for overflow of fuel out into the container as of ob-tention of a certain level of the fuel inside the fuel reserve tankwhen filling the fuel tank by fuel. A bottom region 23 of the fuelreserve tank 21 is provided with an outlet 24 connected to the fuel feed conduit 16 downstream the fuel pick-up inlet 17 thereof through a pressure release valve 25 configured to be closed aslong as fuel is present in the conduit 16 upstream thereof, i.e.closer to the fuel pick-up inlet 17 connected to the float valve 18.The pressure release valve 25 is configured to open upon occur-rence of negative pressure to a certain degree inside the conduit16 so as to drain fuel from the fuel reserve tank when this occurs,which will happen when fuel is pumped through the conduit 16 to the engine and the float valve will close on emptying the container.

A fuel return line 26 enters the fuel tank through the upper accesshole 6 of the container to direct fuel from this line to enter the fuelreserve tank. Means configured to indicate the amount of fuel inthe fuel tank comprises a member 27 measuring the level to whichthe fuel reserve tank is filled for sending information thereabout toa display 28 visible to a driver of the vehicle. The level of the sur-face of fuel in the fuel reserve tank will not start to sink from saidoverflow level before the fuel tank nearly only contains the fuelpresent in the fuel reserve tank, so that the member 27 may delivera reliable indication of the amount of fuel left in the fuel tank to beused for calculating how far the vehicle may still be driven before having to refill the fuel tank.

The invention is of course in no way restricted to the embodimentsdescribed above, since many possibilities for modifications thereofare likely to be obvious to one skilled in the art without having todeviate from the scope of invention defined in the appended claims. 11 The valve in the connection of the fuel reserve tank to the fuel feedconduit may be of another type than in the embodiment describedabove, such as an electrically controlled valve controlled to openor close based on information from sensors arranged to detect the fuel level around the float valve.

Claims

12 Claims

1. A fuel tank for a wheeled motor vehicle comprising o a container (3) configured to contain fuel, o an insert (4) received in the container and extending froman upper access hole (6) of the container for filling the tankwith fuel to a bottom region (7) of the container, and o a fuel feed conduit (16) having a fuel pick-up inlet (17) insaid container for pumping fuel through the conduit to anengine of the vehicle, characterized in that said fuel pick-up inlet (17) of said con- duit (16) is arranged inside said insert (4) in the bottom region of the container, that the insert has a bottom (12) with anopening (14) covered by a first fuel permeable filter (15) to let fuel entering the insert from below through said filter, that a float valve (18) is arranged with a valve body (20) configured to close a connection of the fuel pick-up inlet (17) of said con- duit to the interior of the container through said filter (15) in a bottom position of a float (19) of the float valve (18), and that the float valve is configured to open a connection of said fuelpick-up inlet (17) of the conduit (16) to the interior of the con-tainer for picking up fuel through the bottom (12) of the insert (4) by presence of fuel lifting said float from said bottom posi- tion and by that the valve body to a position opening said con- necüon.

2. A fuel tank according to claim 1, characterized in that thefloat valve (18) is arranged inside said insert (4) and the bot- tom opening (14) of the insert is configured to allow fuel to 13 enter an insert volume surrounding said float valve through the first fuel permeable filter (15).

3. A fuel tank according to claim 1 or 2, characterized in thatthe insert (4) is provided with a plurality of through-holes (8)in walls (9) thereof delimiting an inner volume (10) of the in-sert with respect to a surrounding container volume (11) andextending from said upper access hole (6) to a bottom region(7) of the container so as to allow fuel in the container to flow therethrough into the insert.

4. A fuel tank according to claim 3, characterized in that thefloat valve (18) is arranged inside the insert (4) and a secondfuel permeable filter (30) is arranged above the float valve sothat this filter has to be passed by fuel through influence ofthe gravitation for allowing fuel entering the insert throughsaid through-holes (8) to reach an insert volume surrounding said float valve.

5. A fuel tank according to any of the preceding claims, charac- terized in that it comprises a fuel reserve tank (21) arrangedinside said insert (4) and opening upwardly towards said ac-cess hole (6) of the container so as to be filled by fuel whenfilling the fuel tank with fuel through the access hole, that thefuel reserve tank is provided with an overflow arrangement(22) for overflow of fuel out into said container as of obtentionof a certain level of the fuel inside the fuel reserve tank (21)when filling the fuel tank by fuel, and that a bottom region (23)of the fuel reserve tank is provided with an outlet (24) con- nected to said fuel feed conduit (16) downstream said fuel 14 pick-up inlet (17) thereof through a valve (25) configured tobe closed as long as fuel is present in said conduit upstreamthereof and to open upon occurrence of no fuel inside saidconduit (16) so as to drain fuel from the fuel reserve tank (21) when this occurs.

6. A fuel tank according to claim 5, characterized in that saidvalve (25) in the connection of the fuel reserve tank (21) tothe fuel feed conduit (16) is a pressure release valve config-ured to open upon occurrence of a negative pressure inside said conduit.

7. A fuel tank according to claim 5 or 6, characterized in that itis provided with means configured to indicate the amount offuel in the fuel tank, and that these means comprise a member(27) measuring the level to which the fuel reserve tank (21) isfilled.

8. A fuel tank according to claim any of claims 5-7, character- ized in that said insert (4) is configured to receive a fuel returnline (26) entering the fuel tank through said upper access hole(6) of the container to direct fuel from said fuel return line to enter the fuel reserve tank (21 ).

9. A fuel tank according to any of the preceding claims, charac- terized in that it comprises a member (5) configured to remov-ably secure said insert (4) to the container in the region ofsaid access hole (6), and that the insert and said access holeare designed so as to allow the insert (4) to be removed from the fuel tank through said access hole (6).

10.

11.

12.

13. A fuel tank according to any of the preceding claims, charac- terized in that it is configured to be connected to a compres- sion ignited engine and to contain for example diesel as fuel. A fuel tank according to any of the preceding claims, charac- terized in that it has a volume making it able to contain morethan 100 litre fuel and it is configured to be arranged in a heavy wheeled motor vehicle, such as a truck or a bus. A fuel tank according to any of the preceding claims, charac-terized in that said container (31) has a length dimensionreaching and exceeding 300mm, 500mm, 1 000 mm, 1 500mm or 1 800 mm in a direction configured to be horizontal when said vehicle is arranged on a horizontal ground. A wheeled motor vehicle, in particularly a heavy wheeled mo-tor vehicle, such as a truck or a lorry or a bus, characterizedin that it is provided with a fuel tank according to any of claims1-12.