EP3439906A1

EP3439906A1 - A fuel tank

Info

Publication number: EP3439906A1
Application number: EP17779432.8A
Authority: EP
Inventors: Sydney IKEMEFUNA-AMAECHI
Original assignee: Scania CV AB
Current assignee: Scania CV AB
Priority date: 2016-04-04
Filing date: 2017-03-14
Publication date: 2019-02-13
Also published as: CN108883698A; EP3439906A4; SE539790C2; SE1650445A1; BR112018068792A2; WO2017176187A1; KR20180121612A

Abstract

A fuel tank for a wheeled motor vehicle comprises a container (3) configured to contain fuel, an insert (4) received in the container and extending from an upper access hole (6) of the container for filling the tank with fuel to a bottom region of the container and a fuel feed conduit (16) having a fuel pick-up inlet (17) in the container for pumping fuel through the conduit to an engine of the vehicle. The fuel pick-up inlet is arranged inside the insert in the bottom region of the container. A float valve (18) is arranged with a valve body configured to close a connection of the fuel pick-up inlet of the conduit to the interior of the container through a filter covering an opening in the bottom of the insert in a bottom position of a float of the float valve and to open this connection when the float is lifted by fuel.

Description

A fuel tank

TECHN ICAL FI ELD OF TH E INVENTION

The present invention relates to a fuel tank for a wheeled motor vehicle comprising

• a contai ner configured to contai n fuel ,

• an i nsert received in the container and extending from an upper access hole of the contai ner for fi lling the tank with fuel to a bottom region of the container, and

• a fuel feed conduit having a fuel pick-up i nlet in said contai ner for pumping fuel th rough the conduit to an engine of the vehicle.

The invention is not restricted to fuel tanks for any special type of wheeled motor vehicles, although it is especially directed to heavy motor vehicles, such as buses and trucks, having large fu el tanks which may contain 1 00 litre fuel or more when full , which is the reason why the invention will hereinafter mai nly be discussed for that application for illu minating the invention but not restricting it thereto.

Furthermore, the invention covers fuel tanks for contain ing any conceivable fuel but is particularly directed to fuel tanks for contai ning fuel for compression ignited engines, such as diesel .

Due to the sensitivity of especially diesel engines to di rt and particularly air i n 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 air may enter the fuel feed conduit irrespectively of the appearance of the ground on which the vehicle is standing. Such fuel tanks for heavy motor vehicles have a considerable volume and are often elongated in a direction in parallel with the ground on which a vehicle is standing, which means that a considerable volume of the fuel will not be available for use owing to the required height of the position of said fuel pick-up inlet, i.e. the fuel tank will contain a high 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 production line, which is tantamount to high cost for the manufacturer.

BACKGROUND ART US 2014/0075732 A1 discloses a fuel tank of the type defined in the 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 the type 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 providing such 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 th is may be arranged in the bottom region of the container while sti ll ensu ring that no dirt will enter the fuel feed conduit and in particular that no air wil l enter the fuel feed conduit irrespectively of the inclination of said motor vehicle and by that of the fuel tank and how much fuel is in said tank, si nce when there is not fuel present around the float of the float valve th is will si nk to said bottom position and close the con nection of the fuel p ick-up inlet to the interior of the container. This means that said volume of the fuel tank may be reduced considerably, and the amount of fuel needed for the initial fill at the production li ne will also be remarkably reduced saving costs for the manufacturer. The reduced dead volume also means that the vehicle may be driven a longer distance after filling than before.

Accordi ng to an embodiment of the invention the float valve is arranged inside said insert and the bottom opening of the insert is configu red to al low fuel to enter an i nsert volu me surrounding said float valve through the first fuel permeable filter. This means that the float valve may open said connection to the fuel feed conduit as long as there is fuel present on the bottom of the contai ner in the region of said insert.

Accordi ng to another embodiment of the invention the insert is pro- vided with a pl ural ity of through-holes in walls thereof delimiti ng an inner volu me of the insert with respect to a surrounding contai ner volume and extend ing from said upper access hole to a bottom region of the container so as to allow fuel in the contai ner to flow therethrough into the i nsert. The insert may by this be fi lled with fuel when present to a certain level in said container. Accordi ng to another embodiment of the i nvention constituting a further development of the embodiment last mentioned the float valve is arranged inside the insert and a second fuel permeable filter is arranged above the float valve so that this filter has to be passed by fuel throug h influence of the g ravitation for allowi ng fuel entering the insert throug h said through -holes to reach an i nsert volume surrounding said float valve. It is by that ensured that dirt in the fuel will not reach the float valve, since it has either to pass the first fuel permeable filter or the second permeable filter for reaching the float valve.

Accordi ng to another embodiment of the invention the fuel tank comprises a fuel reserve tank arranged inside said insert and opening upwardly towards said access hole of the container so as to be fil led by fuel when filli ng the fuel tank with fuel through the access hole, the fuel reserve tank is provided with an overflow arrangement for overflow of fuel out into said container as of ob- tention of a certai n level of the fuel i nside the fuel reserve tank when filling the fuel tank by fuel , and a bottom region of the fuel reserve tank is provided with an outlet con nected to said fuel feed conduit downstream said fuel pick-up inlet thereof through a valve configured to be closed as long as fuel is present in said conduit upstream thereof and to open upon occurrence of no fuel inside said conduit so as to drain fuel from the fuel reserve tank when this occurs. The combination of the arrangement of the fuel pickup inlet in the bottom region of the container with a cooperation thereof with a float valve and the arrangement of said fuel reserve tank will result in a possibil ity to reliably drive the vehicle without any risk of coming to an u nintentional stil l standi ng even with a small amount of fuel left in the fuel tank, since fuel will be taken from the fuel reserve tank as soon as it will not be possible to take it from the contai ner through the fuel pick-up inlet and the fuel reserve tank will then also be fi lled to the level of said overflow arrangement. Thus, would a not neglectable amount of fuel stil l be present in the container of the fuel tank and the vehicle drive up or down a steep hi ll and the float valve will close fuel will shortly be taken from the fuel reserve tank until the road flatten out and it will be taken from the container again . This means that the vehicle may reliably be driven as long as there is fuel in the fuel reserve tank and accordi ngly to a point with a very small amount of fuel left i n the fuel tank.

Accordi ng to another embodiment of the invention said valve in the connection of the fuel reserve tank to the fuel feed conduit is a pressure release valve configured to open upon occurrence of a negative pressure inside said conduit. The arrangement of a pressure release valve to control drai ning of fuel from the fuel reserve tank 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.

Accordi ng to another embodiment of the i nvention the fuel tank is provided with means configu red to i ndicate the amount of fuel in the fuel tank, and these means comprise a member measuring the level to which the fuel reserve tank is filled. The emptying of the fuel reserve tank will pri ncipally be started when there is no fuel left in the container, and the member measu ring the level of the fuel in the fuel reserve tank wi ll by that i ndicate the amou nt 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 runni ng out of fuel .

Accordi ng to another embodiment of the invention said insert is configured to receive a fuel return line entering the fuel tank through said upper access hole of the container to direct fuel from said fuel return li ne to enter the fuel reserve tank. It is by this ensured that the fuel reserve tank is kept filled u nti l the moment when nearly no fuel is left in the contai ner of the fuel tank.

Accordi ng to another embodiment of the invention the fuel tank comprises a member configu red to removably secure said insert to the contai ner in the reg ion of said access hole, and the insert and said access hole are designed so as to allow the insert to be removed from the fuel tank throug h said access hole. This means that the i nsert may be removed from the fuel tank for repai r or mai ntenance or exchange thereof increasing the service ability of the fuel tank. Fu rthermore, th is type of securing of the i nsert avoids welds, so that fastening of the insert may be accomplished by means making it possible to produce the i nsert by lig ht materials.

Accordi ng to another embodiment of the invention the fuel tank is configured to be con nected to a compression ignited engine and to contai n for example diesel as fuel . The fuel tank according to the invention is particularly suitable for use in fuel systems of such engines being very sensitive to penetrating of ai r i nto the fuel system . Accordi ng to another embodiment of the invention the fuel tank has a volume maki ng it able to contai n more than 1 00 litre fuel and it is configured to be arranged i n a heavy wheeled motor veh icle, such as a truck or a bus. A fuel tank desig ned in accordance with the present invention may in such an embodiment reduce the dead volume with respect to known such fuel tanks considerably.

Accordi ng to another embodiment of the invention said container has a dimension reachi ng and exceeding 300m m, 500mm , 1 000 mm , 1 500 m m or 1 800 mm in a di rection configured to be horizontal when said vehicle is arranged on a horizontal ground. A fuel tank with such an extension wi ll require a substantial amount of fuel in the fuel tank for ensuring that at least half of the bottom thereof is covered by fuel when the vehicle is standing on a steep road, so that a said dead vol ume 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 featu res of the invention will appear from the description following below.

BRI EF D ESCRI PTION OF TH E DRAWING

With reference to the appended drawing , below follows a specific description of an embodiment of the invention cited as an example.

In the drawing : Fig 1 is a schematic view illustrating a fuel tank accordi ng to an embodi ment of the i nvention , and

Fig 2 is an enlarged view of a float valve arranged in the fuel tank shown i n Fig 1 .

DETAILE D DESCRI PTION OF AN EMBODIM ENT OF TH E INVENTION Fig 1 ill ustrates schematical ly a fuel tank 1 for a wheeled motor vehicle 2 according to an embodiment of the invention . The fuel tank comprises a container 3 config ured to provide the main volume for fuel of the fuel tank and an insert 4 removably secured by a securing member 5 to the container 3 at an access hole 6 of the container for filling the tank with fuel for i nserting the insert through this access hole 6 and remove it from the container through that hole.

The insert 4 extends when secu red to the container from the upper access hole 6 to a bottom region 7 of the contai ner. The insert is provided with a pl urality of through -holes 8 in walls 9 thereof delimiting an inner volume 1 0 of the insert with respect to a surrounding container vol ume 1 1 and extending from the upper access holes 6 to a bottom region of the container so as to al low fuel in the container to flow through these holes 8 i nto the insert.

The insert has a bottom 1 2 to be arranged next to the bottom 1 3 of the container and which is provided with an opening 1 4 covered by a fi rst fuel permeable filter 1 5 to let fuel entering the insert from below through that filter. A fuel feed conduit 1 6 for feeding fuel to an engine of the vehicle has a fuel pick-up inlet 1 7 located i nside the i nsert in the bottom reg ion thereof. This inlet 1 7 is connected to a float valve 1 8 (see now also Fig 2) having a float 1 9 to be lifted by fuel surrounding it inside the i nsert so as to lift a valve body 20 and opening a connection of the fuel pick-up inlet 1 7 to said filter 1 5 for enabling fuel to pass through said filter and into the fuel conduit. When there is no fuel l ifting the float 1 9 this and the valve body 20 wi ll assume a bottom position in which the valve body 20 is closing the connection of the fuel pick-up inlet 1 7 to the i nterior of the container through the filter 1 5.

A second fuel permeable filter 30 is arranged above the float valve 1 8 so that this fi lter has to be passed by fuel through influence of the gravitation for al lowing fuel enteri ng the insert through the holes 8 to reach an insert volume su rroundi ng the float valve. This second 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 of 1 5 - 1 00 litre depending on the container volu me, is arranged inside the i nsert 4 and opens upwardly towards the access hole 6 of the container so as to be filled by fuel when filling the fuel tank with fuel . The fuel reserve tank is provided with an overflow arrangement 22 for overflow of fuel out i nto the container as of ob- tention of a certain level of the fuel inside the fuel reserve tank when filling the fuel tank by fuel . A bottom region 23 of the fuel reserve tank 21 is provided with an outlet 24 con nected to the fuel feed conduit 1 6 downstream the fuel pick-up i nlet 1 7 thereof through a pressure release valve 25 configured to be closed as long as fuel is present in the conduit 1 6 upstream thereof, i .e. closer to the fuel pick-up inlet 1 7 connected to the float valve 1 8. The pressure release valve 25 is configu red to open upon occur- rence of negative pressure to a certain degree inside the conduit 1 6 so as to drain fuel from the fuel reserve tank when this occurs, which will happen when fuel is pumped through the conduit 1 6 to the engi ne and the float valve will close on emptying the container. A fuel return line 26 enters the fuel tank throug h the upper access hole 6 of the container to di rect fuel from this line to enter the fuel reserve tank. Means configured to i ndicate the amount of fuel i n the fuel tank comprises a member 27 measuring the level to which the fuel reserve tank is filled for sending information thereabout to a display 28 visible to a driver of the vehicle. The level of the surface of fuel in the fuel reserve tank will not start to sink from said overflow level before the fuel tank nearly only contains the fuel present in the fuel reserve tank, so that the member 27 may deliver a reliable indication of the amount of fuel left in the fu el tank to be used for calcu lating 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 embodiments described above, since many possibilities for modifications thereof are l ikely to be obvious to one skilled in the art without havi ng to deviate from the scope of invention defined in the appended claims. The valve i n the connection of the fuel reserve tank to the fuel feed conduit may be of another type than in the embodiment described above, such as an electrically controlled valve controlled to open or close based on i nformation from sensors arranged to detect the fuel level arou nd the float valve.

Claims

A fuel tank for a wheeled motor vehicle comprising

• a container (3) configured to contain fuel,

• an insert (4) received in the container and extending from an upper access hole (6) of the container to a bottom region (7) of the container, and

• a fuel feed conduit (16) having a fuel pick-up inlet (17) in said container for pumping fuel through the conduit to an engine of the vehicle,

said fuel pick-up inlet (17) of said conduit (16) being arranged inside said insert (4) in the bottom region of the container, the insert having a bottom (12) with an opening (14) covered by a first fuel permeable filter (15) to let fuel entering the insert from below through said filter, a float valve (18) being arranged with a valve body (20) configured to close a connection of the fuel pick-up inlet (17) of said conduit to the interior of the container through said filter (15) in a bottom position of a float (19) of the float valve (18), and the float valve being configured to open a connection of said fuel pick-up inlet (17) of the conduit (16) to the interior of the container for picking up fuel through the bottom (12) of the insert (4) by presence of fuel lifting said float from said bottom position and by that the valve body to a position opening said connection, characterized in that it comprises a fuel reserve tank (21) arranged inside said insert (4) and opening upwardly towards said access hole (6) of the container, through which access hole (6) the tank is to be filled with fuel, so as to be filled by fuel when filling the fuel tank with fuel through this access hole, that the fuel reserve tank is provided with an overflow arrangement (22) for overflow of fuel out into said container as of obtention of 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 pick-up inlet (17) thereof through a valve (25) configured to be closed as long as fuel is present in said conduit upstream thereof and to open upon occurrence of no fuel inside said conduit (16) so as to drain fuel from the fuel reserve tank (21) when this occurs.

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

A fuel tank according to claim 1 or 2, characterized in that the insert (4) is provided with a plurality of through-holes (8) in walls (9) thereof delimiting an inner volume (10) of the insert with respect to a surrounding container volume (11) and extending 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.

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

A fuel tank according to any of the preceding cl aims, characterized i n that said valve (25) in the connection of the fuel reserve tank (21 ) to the fuel feed conduit ( 1 6) is a pressure release valve configured to open upon occurrence of a negative pressure i nside said conduit.

A fuel tank according to any of the precedi ng clai ms, characterized in that it is provided with means configured to indicate the amou nt of fuel in the fuel tank, and that these means comprise a member (27) measuring the level to wh ich the fuel reserve tank (21 ) is filled.

A fuel tank according to claim any of the precedi ng claims, characterized in that said insert (4) is configured to receive a fuel return li ne (26) entering the fuel tank through said upper access hole (6) of the contai ner to direct fuel from said fuel return l ine to enter the fuel reserve tank (21 ) .

A fuel tank according to any of the preceding claims, characterized in that it comprises a member (5) configured to removably secure said i nsert (4) to the container in the region of said access hole (6), and that the insert and said access hole are designed so as to allow the insert (4) to be removed from the fuel tank through said access hole (6) .

9. A fuel tank according to any of the preceding claims, characterized in that it is configured to be connected to a compression ignited engine and to contain for example diesel as fuel.

10. A fuel tank according to any of the preceding claims, characterized in that it has a volume making it able to contain more than 100 litre fuel and it is configured to be arranged in a heavy wheeled motor vehicle, such as a truck or a bus.

11. A fuel tank according to any of the preceding claims, characterized in that said container (31) has a length dimension reaching and exceeding 300mm, 500mm, 1 000 mm, 1 500 mm or 1 800 mm in a direction configured to be horizontal when said vehicle is arranged on a horizontal ground.

12. A wheeled motor vehicle, in particularly a heavy wheeled

motor vehicle, such as a truck or a lorry or a bus, characterized in that it is provided with a fuel tank according to any of claims 1-11.