Fuel delivery unit for a motor vehicle

Abstract

A fuel delivery unit for a motor vehicle, wherein a swirl pot has a base formed from an upper part and a lower part, and an outer wall connected to the base, forming a seal. The upper part and the lower part bound fuel-delivering regions of a suction jet pump and of a section of a feed line. This arrangement allows the fuel delivery unit to be produced at particularly low cost.

Description

The invention relates to a fuel delivery unit for a motor vehicle, having a fuel pump, which is arranged in a swirl pot, for delivering fuel from the swirl pot into a feed line, having a suction jet pump for delivering fuel into the swirl pot, having a propellant line which leads from the fuel pump to a nozzle of the swirl pot, and having a mixing tube, which opens out into the swirl pot, of the suction jet pump, with the swirl pot having a casing which is fastened to a base.

Fuel delivery units of said type are frequently used in modern motor vehicles and are known from practice. In the known fuel delivery units, individual components are inserted into the swirl pot, which is usually formed in one piece, and are connected to one another. A port, which projects away from the fuel pump, for a feed line usually projects out of the swirl pot. However, since a fine filter which is arranged in the feed line is often arranged within the swirl pot, the feed line from the fuel pump is guided back into the swirl pot again to the fine filter. Furthermore, a branch is usually guided from the feed line to the suction jet pump which is provided for filling the swirl pot. This leads to a very large installation space of the known fuel delivery unit and to complex assembly.

The invention is based on the problem of refining a fuel delivery unit of the type specified in the introduction in such a way that said fuel delivery unit is of particularly simple and compact design.

Said problem is solved according to the invention in that the base has an upper part, which faces toward the fuel pump, and a lower part, which faces away from the fuel pump, in that the upper part and lower part are sealed off with respect to one another and in that fuel-guiding regions are arranged between the upper part and the lower part of the base.

By means of said design, it is possible for partial regions of fuel-guiding regions, such as of the lines, to be arranged within the base of the swirl pot. On account of the invention, the upper part and the lower part form preferably shell-shaped components which receive sections of the lines. Said lines therefore need no longer be mounted separately. Components projecting from the swirl pot can be easily avoided in this way. Furthermore, by means of a corresponding arrangement of the parting plane in the base, it is possible for the upper part and lower part to be produced in each case as axially demoldable injection-molded parts.

The fuel delivery unit according to the invention is of particularly simple structural design if the fuel-guiding regions of the base have a section, which leads from the fuel pump to the fine filter which is arranged in the swirl pot, of a feed line, with the section of the feed line being delimited partially by the upper part and the lower part of the base. The upper part and the lower part are preferably each formed in the manner of a half-shell and bear against one another so as to delimit the section of the feed line. This contributes to a particularly compact design of the fuel delivery unit according to the invention.

To further simplify the structural design of the fuel delivery unit according to the invention, it is expedient if the fuel-guiding regions of the base have the mixing tube of the suction jet pump, with the mixing tube being formed partially by the upper part and by the lower part. The upper part and the lower part are preferably each formed in the manner of a half-shell and bear against one another so as to delimit the mixing tube. This contributes to a particularly compact design of the fuel delivery unit according to the invention.

To further reduce the number of components of the fuel delivery unit according to the invention, it is expedient if the upper part of the base and the casing seal off a fine filter which is arranged in the swirl pot.

According to another advantageous refinement of the invention, the structural expenditure for the precise alignment of the components of the base plate can be kept particularly low if the upper part and the lower part of the base each have annular edges which bear against one another. The upper part and the lower part preferably have positively locking surfaces which correspond to one another and by means of which said upper part and lower part engage into one another in a positively locking manner.

To further simplify the alignment of the components of the swirl pot, it is expedient if at least one of the edges of the upper part or of the lower part is sealed off with respect to the casing of the swirl pot. The base of the swirl pot is also reliably sealed off in this way.

The mixing tube of the suction jet pump could for example open out into a chamber, which is closed off by means of a base valve, of the swirl pot. However, to further reduce the number of components of the fuel delivery unit according to the invention, it is expedient if the mixing tube is sealingly connected to a riser tube which is formed in one piece with the casing of the swirl pot and if the riser tube extends into a region, which is remote from the base, of the intended maximum filling level of the swirl pot. As a result of said design, the swirl pot does not require a base valve, since the length of the riser tube limits the filling level in the swirl pot. Since the riser tube is arranged on the casing of the swirl pot and extends over a partial region of the height thereof, the swirl pot can be produced together with the riser tube in a particularly cost-effective manner in an axially demoldable injection mold.

According to another advantageous refinement of the invention, to further reduce the number of components of the fuel delivery unit according to the invention, it is expedient if a section, which leads away from the fine filter, of the feed line is formed in one piece with the casing of the swirl pot.

The assembly of the fuel delivery unit according to the invention is particularly simple if ports of the nozzle of the suction jet pump and of the section of the feed line, which leads from the fuel pump to the fine filter, are aligned perpendicular to the surface of the base of the swirl pot. As a result of said design, the fuel pump can be plugged axially onto the ports in a simple manner, and is thereby fully mounted. Here, a suction port of the fuel pump preferably opens out into the base region of the swirl pot.

The invention permits numerous embodiments. To further clarify its basic principle, one of said embodiments is illustrated in the drawing and is described below. In the drawing:

FIG. 1 schematically shows a fuel supply device for an internal combustion engine of a motor vehicle having a fuel delivery unit according to the invention.

FIG. 2 shows a sectioned illustration of the fuel delivery unit according to the invention from FIG. 1, and

FIG. 3 shows, on a greatly enlarged scale, a sectioned illustration of a base of a swirl pot of the fuel delivery unit according to the invention from FIG. 1.

FIG. 1 schematically shows a fuel delivery unit 2, which is arranged in a fuel tank 1 of a motor vehicle, for delivering fuel to an internal combustion engine 3 of a motor vehicle. The fuel delivery unit 2 sucks in fuel from the base region of the fuel tank 1 and delivers said fuel into a feed line 4 which leads to the internal combustion engine 3.

FIG. 2 shows, on a greatly enlarged scale, a sectioned illustration of the fuel delivery unit 2 from FIG. 1 with an electrically operated fuel pump 6 which is arranged in a swirl pot 5. A fine filter 7 is also arranged in the swirl pot 5. The swirl pot 5 has a base 9 which is connected to a casing 8. The base 9 and the casing 8 seal off the fine filter 7. The base 9 also has a suction jet pump 10. The suction jet pump 10 is supplied with fuel as propellant by the fuel pump 6, sucks fuel out of the surroundings of the swirl pot 5 and delivers said fuel into the swirl pot 5. For this purpose, the suction jet pump 10 has a nozzle 11 which is connected to the fuel pump 6. The casing 8 of the swirl pot 5 is connected in one piece to a riser tube 12. The riser tube 12 is connected to a mixing tube 13, which is arranged in the base 9, of the suction jet pump 10. A section 14 of the feed line 4 from the fuel pump 6 to the fine filter 7 also leads through the base 9. A further section 15, which is arranged downstream of the fine filter 7 in the flow direction, of the feed line 4 is formed in one piece with the casing 8 of the swirl pot 5.

FIG. 3 shows, on a greatly enlarged scale, the base 9 of the swirl pot 5 from FIG. 1. Here, it can be seen that the base 9 has an upper part 16 and a lower part 17 which is sealingly connected to the upper part 16. The upper part 16 and the lower part 17 form in each case one part of the mixing tube 13 of the suction jet pump 10 and that section 14 of the feed line 4 which leads from the fuel pump 6 to the fine filter 7. Ports 18 of that section 14 of the feed line 4 which is arranged between the fuel pump 6 and the fine filter 7 and of the suction jet pump are aligned perpendicular to the surface on the base 9, such that the fuel pump 6 illustrated in FIG. 2 can be easily plugged on in order to be mounted. Furthermore, FIG. 3 shows that the upper part 16 and the lower part 17 of the base 9 each have annular edges 20, 21 which bear against one another. The edges 20, 21 are sealed off with respect to the casing 8, illustrated in FIG. 2, of the swirl pot 5.

Claims

1.-9. (canceled)

10. A fuel delivery unit for a motor vehicle, comprising: a swirl pot casing forming a swirl pot;a fuel pump arranged in the swirl pot, the fuel pump configured to deliver fuel from the swirl pot into a feed line;a suction jet pump configured to deliver the fuel into the swirl pot, the suction jet pump comprising: a nozzle;a propellant line coupled between the fuel pump and the nozzle; anda mixing tube coupled to the nozzle, the mixing tube feeding the fuel into the swirl pot;a base section fastened to the swirl pot casing, the base section comprising: an upper base part that faces toward the fuel pump; anda lower base part that faces away from the fuel pump,wherein at least one of the mixing tube, the propellant line, and the nozzle is arranged between the upper base part and the lower base part.

11. The fuel delivery unit according to claim 10, further comprising: a fine filter arranged in the swirl pot; anda fuel-guiding region in the base coupled between the fuel pump and the fine filter, the fuel-guiding region being delimited partially by the upper base part and the lower base part.

12. The fuel delivery unit according to claim 10, wherein the mixing tube is formed partially by the upper base part and by the lower base part.

13. The fuel delivery unit according to claim 11, wherein the upper base part and the casing form a compartment for the fine filter.

14. The fuel delivery unit according to claim 10, wherein the upper base part and the lower base part each have annular edges configured to bear against one another.

15. The fuel delivery unit according to claim 14, wherein at least one of the edges of the upper base part or of the lower base part is sealed to the casing.

16. The fuel delivery unit according to claim 10, wherein the mixing tube is connected to a riser tube formed in one piece with the casing, the riser tube extending into a region of the swirl pot remote from the base to an intended maximum filling level of the swirl pot.

17. The fuel delivery unit according to claim 11, wherein a line section that leads away from the fine filter is formed in one piece with the casing.

18. The fuel delivery unit according to claim 11, wherein ports of the nozzle of the suction jet pump and of the fuel-guiding region, are substantially perpendicular to a surface of the base that faces toward the fuel pump.

19. The fuel delivery unit according to claim 10, wherein at least one of the upper base part and the lower base part are axially demoldable injection molded parts.