GB2599913A - Reservoir for a fuel delivery module - Google Patents

Abstract

A fuel reservoir assembly of a fuel delivery module comprising a reservoir (14, fig.1) with an integrated a jet pump (40, fig.1) including a drive fuel duct (44, fig.1), a mixing duct and a nozzle device (48, fig.1). The nozzle comprising a body 68 with a tubular peripheral wall 70 defining an axially extending inner passageway 72. The wall includes an inlet port 76 and a nozzle orifice 92 axially spaced from each other. The nozzle body 68 is moulded from plastic and has an end opening 74 and a lateral aperture 96. A plastic rod-shaped plug member 100 extends axially in the passageway 72, closing the end orifice 74 and lateral aperture 96. The plug member 100 is further configured to form a fuel channel 114 in communication with the inlet port and nozzle orifice. The use of an elongated single plug member reduces the chance of a plug coming loose.

Description

RESERVOIR FORA FUEL DELIVERY MODULE

The present invention generally relates to the field of fuel delivery modules as found in liquid fuel tanks of automotive vehicles, and particularly relates to the design of the reservoir of such module.

BACKGROUND OF THE INVENTION

Transportation vehicles such as trucks, cars, planes and boats operating thermal engines include an on-board fuel tank to hold fuel to be used by the engine. The fuel tank generally includes a fuel delivery module disposed therein with a removable cover sealed to the top of the fuel tank having an electrical connector and a fuel line outlet connector. The fuel delivery module includes a fuel reservoir, an electrical fuel pump disposed in the reservoir and a jet pump used to fill the reservoir to overfilling.

Such a fuel delivery module is known e.g. from US 6,405,717. The jet pump is a Venturi effect pump, which includes a tubular body made in one piece from plastic material. The body has a first lateral projection cooperating with a drive fuel supply duct and a second lateral projection cooperating with an overpressure relief duct. The two projections cooperate with an inner passageway defined by the tubular body. A nozzle/orifice insert is disposed in the peripheral wall of the nozzle body (press-fitted), to discharge fuel from the inner passageway towards a mixing duct with Venturi section. The nozzle orifice is typically made from machined brass. Due to manufacturing constraints, in particular in consideration of injection molding specificities, the tubular body has an end face opening. It further includes a lateral aperture opposite the nozzle insert, through which the latter is inserted. These openings are thus closed by two plugs, connected by tethers to the body. Although this design has been successfully used, there are a few shortcomings. When the fuel delivery module is in operation, the fuel circulating in the jet pump body is pressurized and the fuel pressure tends to exert a force on the plugs. Upon assembly, the end-face plug is maintained in place by a reservoir wall, limiting risks of unplugging. This is however not the case for the other plug covering the lateral aperture facing the nozzle insert, which is more likely to pop out under the fuel pressure. Furthermore, due to environmental policies, the use of brass inserts in fuel module is now prohibited The object of the present invention is to provide an improved jet pump design for fuel delivery modules that does not comprise the above-mentioned drawbacks.

SUMMARY OF THE INVENTION

The present invention relates to a reservoir assembly for a fuel delivery module adapted to be installed inside a fuel tank associated with an internal combustion engine, as used typically in automotive vehicles (cars, busses, trucks) but also suitable for other applications.

The reservoir assembly comprises: a reservoir for fuel adapted to be disposed in a liquid fuel tank, the reservoir having a top opening defining an overflow fuel level; holding means adapted for holding a fuel pump in the reservoir; a jet pump for drawing fuel into the reservoir, the jet pump comprising an drive fuel duct, a mixing duct and a nozzle device, wherein the nozzle device comprises body with a tubular peripheral wall defining an axially extending inner passageway, the peripheral wall including an inlet port and a nozzle orifice axially spaced from each other. The inlet port is connected with the drive fuel duct and the nozzle orifice is configured to discharge fuel into the mixing duct.

The nozzle body is molded in one piece from plastic material and has an axial end opening in the passageway and a lateral aperture in the peripheral wall facing the nozzle orifice.

It shall be appreciated that a plastic molded rod-shaped plug member is arranged to extend axially in the passageway, the plug member comprising: a first plug section engaging the passageway to sealingly close the axial end orifice; a second plug section engaging the passageway to prevent fuel flow through the lateral aperture, and a main section, in between the plug sections, with a fuel channel in communication with the inlet port and nozzle orifice.

The present invention proposes a nozzle device design with basically two pieces: the nozzle body and the plug member. The two pieces can be easily manufactured each in one piece from plastic material, in particular via injection molding. POM or other appropriate plastics can be used.

The plug member is configured to be inserted into the tubular body and close the openings (or at least prevent flow there-through), which are required for accommodating the in-mold tools during the injection process. The plug member also serves to convey the fuel from the inlet port to the nozzle orifice.

The present design entails several benefits. Assembly of the nozzle device simply requires fitting the plug member into the nozzle body. There is no risk for the plug member to pop out, contrary to the individual plugs known from US 6,405,717. This is also beneficial in terms of durability and product validation. The nozzle body can be molded with the same interface features as in US 6,405,717, hence the present nozzle device can easily be used with conventional reservoirs.

In embodiments, the nozzle body and plug member are configured such that the plug member press-fittingly engages into the passageway. Such interference fit is also advantageously designed so that the parts engage in a liquid-tight (or sealed) manner.

In this connection, the first plug section and/or the second plug section may be configured to press-fittingly engage the passageway in a liquid-tight manner. This can be easily achieved by means of annular ribs on the outer periphery of the plug sections that engage the inner surface of the passageway.

In embodiments, the first plug section engages with an inlet section of the passageway adjacent the axial end opening. The second plug section is arranged axially after the nozzle orifice.

In embodiments, the second plug section is arranged to cover the lateral aperture. Alternatively the second plug section may not cover the lateral aperture, but is however arranged to prevent fuel flow from the fuel channel towards the lateral aperture.

In embodiments, the end face of the tubular body opposite to the one with the passageway opening is closed.

In embodiments, the main section has an outer surface with an axially extending groove forming, with the passageway, the fuel channel. This is a convenient way of designing the fuel channel. Alternatively, the fuel channel could be designed as an internal channel extending within the core of the plug member and having radial branches joining the inlet port and nozzle orifice; this would however require extra machining.

In embodiments, the nozzle orifice is part of a nozzle portion that is molded with the nozzle body. Such design avoids use of metal nozzle orifice inserts.

In embodiments, the nozzle orifice may be laser drilled through the peripheral wall.

In embodiments, the nozzle orifice is part of a metal insert arranged in an opening in the peripheral wall. In this case environment compatible metals should be used.

The nozzle orifice may have a diameter between 0.3 and 1.3 mm, preferably 0.6 to 0.9 mm.

In embodiments, the inlet port includes a tubular-shaped first projection extending from the peripheral wall and including an aperture communicating with the passageway, the first projection being configured to press-fittingly engage a cavity associated with the drive fuel duct.

In embodiments, the nozzle body includes a tubular-shaped second projection configured to press-fittingly engage a fixing cavity in the reservoir.

In embodiments, the mixing duct has an aperture in a lower region of the reservoir that communicates with the fuel tank and the nozzle orifice is arranged to face the aperture in order to discharge a fuel stream towards said aperture while entraining fuel from said tank based on the Venturi effect.

In embodiments, the aperture of the mixing duct is arranged in a recess in a base portion of the reservoir, and the nozzle device is received in this 10 recess The reservoir assembly normally includes fuel pump holding means. It is integrated to the reservoir and may be formed in one piece with the latter or assembled thereto. The fuel pump holding means are configured to maintain the fuel pump in position in the reservoir such that it is partially immerged in the fuel contained in the reservoir chamber.

According to another aspect, the invention relates to a fuel delivery module comprising a reservoir assembly as disclosed herein and a fuel pump arranged in the reservoir.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will now be described, by way of example, with reference to the accompanying drawings, in which: FIG. 1: is a vertical cross-sectional view through a fuel delivery module including an embodiment of the present reservoir; FIGS. 2 and 3: are longitudinal section views through the nozzle body; FIG. 4: is a perspective view of the plug member; Fig. 5 is a perspective side view of the nozzle body; Fig. 6: is a perspective view of the nozzle body, showing the axial end opening.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT

Fig.1 illustrates an embodiment of fuel delivery module 10 (also known as fuel pump module) adapted for use in a liquid fuel tank of an automotive vehicle with internal combustion engine.

The fuel delivery module 10 is installed inside the fuel tank (only the upper wall thereof 12 is shown), which may be designed to contain liquid fuel such as, e.g., diesel, gasoline, etc. The fuel delivery module 10 comprises a generally bucket-shaped reservoir 14 that is typically made from plastic material. The reservoir 14 has a base portion 16 and an annular side portion 18 extending generally perpendicularly from the base portion 16, thus forming an upwardly open chamber 20 for fuel. The top opening 22 of the reservoir 14 defines an overflow fuel level.

The top wall 12 of the fuel tank is provided with an opening 24 for inserting the fuel delivery module 10 into the fuel tank. As it is known in the art, the fuel tank defines a substantially sealed fuel receiving space when the opening 24 has been closed by a cover or set plate 26.

The reservoir 14, which forms a "subtank" or "reserve cup," is disposed in proximity of the bottom plate within the fuel tank. The reservoir 14 may be fixed to the bottom plate, or rigidly connected to set plate 26 by means of spacing studs (not shown). The reservoir cup 14 reserves a fuel, which flows into the cup 14 from within the fuel tank and is drawn into a fuel pump 28 arranged in the reservoir 14.

Fuel pump 28 typically includes an inlet (not visible) that draws in fuel from the reservoir 14 and at least one pressurized fuel outlet. A fuel pump holding member (not visible), formed in one piece or assembled, is integrated to the reservoir 14 and maintains the fuel pump 28 in position. In use, the lower end of the fuel pump 28, with the inlet, is immersed in the fuel contained in chamber 20. The fuel pump 28 is typically electrically operated and may be of any standard design. The fuel pump outlet is routed to an engine fuel supply line via an outlet hose 30 and a supply port 32 mounted in set plate 26. The engine fuel supply line delivers fuel to the engine's injection system (e.g. a high-pressure common rail system). A pressure relief valve 34 may be integrated in outlet hose 32.

Reference sign 36 designate an electrical connector integrated in the set plate 26 and connecting a wiring harness associated with the fuel pump to supply the latter with power. Electrical connector 36 permits connection of the fuel delivery module to the Engine control unit ECU. The control and operation of a fuel delivery module 12 by an ECU in this regard is well known in the art and does not need to be further detailed herein.

Reference sign 40 generally designates a jet pump arrangement, or simply jet pump, that is integrated to the reservoir 14. The jet pump 40 is arranged in the vicinity of an opening 42 in the reservoir wall that may generally be located in the base wall 16 or nearby. Classically, a jet pump 40 is a device that is configured to create a pumping action to transfer fuel from outside of the reservoir cup 14 into the jet pump 40, and thence into the reservoir chamber 20, by using an auxiliary fuel flow as driving source. This is generally achieved by using the Venturi principle. Here the auxiliary fuel flow is discharged from the fuel pump 24 as a driving source.

The jet pump comprises a drive fuel member 44, a mixing member 46 and a nozzle device 48 that cooperates with the drive and mixing members 44, 46. The drive and mixing members 44, 46 are integral and formed in one piece with the reservoir 14. They extend inside the chamber 20 of the reservoir. The nozzle device 48 is a separate component that is assembled to the reservoir 14, and here located in a recess 50 arranged in the bottom wall 16.

The drive fuel member 44 extends upwardly from the bottom portion 16. It is tubular and has a generally circular cross-sectional shape. Drive fuel member 44 has a passageway 51 extending axially therethrough. It further comprises at its lower end a cavity 52 and an aperture 54 interconnecting the cavity 52 and passageway 51. The cavity 52 opens in the bottom recess 50. In this embodiment, the top end of the drive member 44 includes a coupling portion 56, to which an auxiliary hose 58 is connected. Hose 58 is coupled at its other end to an auxiliary outlet of the fuel, whereby pressurized fuel is supplied through hose 58 to drive fuel member 44 in order to drive the jet pump 40.

The mixing member 46 extends upwardly from the bottom portion 16. It is tubular and has a generally circular cross-sectional shape, although with various sections. The mixing member 46 has a passageway 60 extending axially therethrough. At its lower end the passageway 60 has an aperture 62 opening into recess 50 and is outwardly flared. In operation, fuel is sucked from the fuel tank (i.e. from outside the reservoir) into this mixing member 46 via aperture 62. The passageway 60 further includes a straight intermediate section 64 and ends with a frusto-conical section 66 forming the Venturi tube of the jet pump 40. The upper end of mixing member 46 is open, whereby the fuel flow discharged from passageway 60 falls into the chamber 20.

As best seen in Figs. 2 and 3, the nozzle device 48 comprises a tubular-shaped body 68 having a peripheral wall 70 extending along a longitudinal axis L and surrounding an internal passageway 72. The body 68 is molded in one piece from plastic material. The passageway 68 is open at one end, with an axial end opening 74 in the end face 68.1 of body 68, and closed at the other end 68.2. The body 68 has, close to the open end 68.1, a first projection 76 extending outwardly, perpendicularly to axis L. The first projection 76 has a tubular shape and forms an inlet portion with an aperture 78 in wall 70 to communicate with the inner passageway 72. The first projection 76 may include a number of spaced, annular outer ribs 80 that engage with the inner surface of the cavity 52 in assembled configuration.

It may further include a plurality of axially extending and circumferentially spaced ribs 82 cooperating with cavity 52. A second outwardly extending projection 84 is arranged towards the centre of the body 68. It has a tubular shape with outer annular ribs 86 to engage an inner surface of a corresponding cavity 88 at the bottom of the reservoir 14.

The annular ribs 80 and 86 permit an easy fixation of the nozzle device 48 by press-fit, which is also liquid tight.

Reference sign 90 designates a nozzle integrated in the peripheral wall and having a calibrated orifice 92 that communicates with the internal passage. The nozzle 90 is here molded with the body 68. The orifice 92 is located at the outward end of a recess 94 in peripheral wall 70. Seen from the outside, the nozzle orifice is surrounded by a flattened nozzle portion. The diameter of the orifice 92 may range from 0.3 to 1.3 mm, preferably 0.6 to 0.9 mm.

As can be seen, peripheral wall 70 includes a lateral aperture 96 positioned opposite the nozzle 90. This aperture 96 is required for the insertion of in-mold tools to form the nozzle during the body molding process.

As can be understood from Fig. 1, the first and second projections 76, 84, with their annular ribs 80, 86, allow fixing the nozzle device 48 to the reservoir 14, within recess 50. The first projection 76 permits communication with the drive member 44, whereby fuel is able to flow into the body 68. The second projection 84 has a fixation function. The nozzle device 48 is configured such that nozzle orifice 92 is aligned with the aperture 62 of member 46, however without obturating the latter. In operation, the flow of fuel out discharged from nozzle orifice 92 and through mixing member 46 (with Venturi section) causes a reduction in pressure in the region of chamber 50 relative to the pressure in the main fuel tank, which in turn causes fuel to be entrained (as indicated by arrows in Fig. 1) from the tank into the jet pump 40 through mixing member 46 and then into the reservoir Turning back to Fig.2, the nozzle body 68 further includes an elongate plug member 100 inserted into the inner passage 72 and extending (along axis L) over the full length thereof. Plug member 100 is a one piece, solid, plastic molded part having a first plug section 102, at a first end, that is configured to engage in a sealed manner with the inlet section 72.1 of passage 72, i.e. adjacent opening 74. First plug section 102 has a larger diameter than the remainder of the plug member 100, and is provided with annular ribs 104, engaging the surface of inlet section 72.1, and with a radial flange 106 that abuts against the end face 68.1 of body 68.

Plug member 100 includes a second plug section 108, opposite the first one, configured to sealingly close the opposite end of the internal passage, namely to close the aperture 96. The main section 110 of plug member 100, in between the two plug sections 102, 108, has a cross-section generally matching the inner diameter of passage 72. However, an axial groove 112 is arranged in the main section 110 that extends from inlet port 78 to the nozzle 90. This axial groove 112 thus defines, with the part of the peripheral wall 72 covering the groove 112, an internal fuel channel 114 that communicates with inlet aperture 78 and nozzle orifice 92, thus guiding the flow of fuel through the nozzle 48.

In order to properly position the plug member 100 inside the passage 72, a protruding axial rib 116 is provided on the bottom side of plug member 100, opposite groove 112. This rib 116 cooperates with an indexing groove 118 arranged in passage 72.

The nozzle device 48 thus is a two piece device, where body 68 is molded 20 with the desired connection features, and the inner plug member 100 obturates the body openings required to implement the molding process.

Claims (14)

1. CLAIMS: 1. A fuel reservoir assembly of a fuel delivery module, comprising: a reservoir (14) adapted to be disposed in a liquid fuel tank, said reservoir having a top opening (22) defining an overflow fuel level; a jet pump (40) for drawing fuel into said reservoir (14), said jet pump (40) comprising an drive fuel duct (44), a mixing duct (46) and a nozzle device (48), wherein said nozzle device comprises a body (68) with a tubular peripheral wall (70) defining an axially extending inner passageway (72), said peripheral wall including an inlet pod (76) and a nozzle orifice (92) axially spaced from each other, said inlet port being fluidly connected with said drive fuel duct (44) and said nozzle orifice (92) being configured to discharge fuel into mixing duct (46); said nozzle body (68) is molded in one piece from plastic material and has an axial end opening (74) and a lateral aperture (96) in said peripheral wall (70) facing said nozzle orifice (92); characterized in that a plastic molded rod-shaped plug member (100) is arranged to extend axially in said passageway (72), said plug member comprising: a first plug section (102) engaging said passageway to sealingly close said end orifice (74) a second plug section (108) engaging said passageway to prevent fuel flow through said lateral aperture (96), and a main section (116), in between said plug sections, configured to form a fuel channel (114) in communication with said inlet port and nozzle orifice.
2. 2. The fuel reservoir assembly according to claim 1, wherein said plug member (100) is press-fittingly engaged in said passageway (72).
3. 3. The fuel reservoir assembly according to claim 2, wherein said first plug section and/or said second plug section is/are configured to press-fittingly engage said passageway in a liquid-tight manner.
4. 4. The fuel reservoir assembly according to any one of the preceding claims, wherein said first plug section (102) and/or said second plug section (108) include annular ribs (104) engaging said passageway.
5. 5. The fuel reservoir assembly according to any one of the preceding claims, wherein said main section has an outer surface with an axially extending groove forming, with said passageway, said fuel channel.
6. 6. The fuel reservoir assembly according to any one of the preceding claims, wherein said second plug section covers said lateral aperture in said peripheral wall.
7. 7. The fuel reservoir assembly according to any one of the preceding claims, wherein said nozzle orifice is part of a nozzle portion molded with said nozzle body (68) or is part of metal insert arranged in an opening in said peripheral wall.
8. 8. The fuel reservoir assembly according to any one of the preceding claims, wherein said nozzle orifice has a diameter between 0.3 and 1.3 mm, preferably 0.6 to 0.9 mm.
9. 9. The fuel reservoir assembly according to any one of the preceding claims, wherein said inlet port (76) includes a tubular-shaped first projection extending from said peripheral wall (70) and including an aperture (78) communicating with said passageway 72, said first projection being configured to press-fittingly engage a cavity (52) associated with said drive fuel duct (44).
10. 10. The fuel reservoir assembly according to any one of the preceding claims, wherein said nozzle body includes a tubular-shaped second projection (84) configured to press-fittingly engage a fixing cavity (88) in said reservoir.
11. 11. The fuel reservoir assembly according to any one of the preceding claims, wherein said mixing duct (46) has an aperture (62) in a lower region of said reservoir that communicates with said fuel tank and said nozzle orifice (92) is arranged to face said aperture (62) in order to discharge a fuel stream towards said aperture (62) while entraining fuel from said tank.
12. 12. The fuel reservoir assembly according to any one of the preceding claims, wherein said aperture (62) is arranged in a recess (60) in a base portion of said reservoir, and said nozzle device (48) is received in said 15 recess.
13. 13. The fuel reservoir assembly according to any one of the preceding claims, further comprising holding means adapted for holding a fuel pump (28) in said reservoir (14).
14. 14. A fuel delivery module comprising a reservoir assembly according to any one of the preceding claims and a fuel pump arranged in said reservoir.