EP0526574A1 - Fuel system for an internal combustion engine - Google Patents

Fuel system for an internal combustion engine

Info

Publication number
EP0526574A1
EP0526574A1 EP19910909287 EP91909287A EP0526574A1 EP 0526574 A1 EP0526574 A1 EP 0526574A1 EP 19910909287 EP19910909287 EP 19910909287 EP 91909287 A EP91909287 A EP 91909287A EP 0526574 A1 EP0526574 A1 EP 0526574A1
Authority
EP
European Patent Office
Prior art keywords
fuel
chamber
flow
engine
return
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP19910909287
Other languages
German (de)
French (fr)
Inventor
Gert Bjerendal
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Saab Automobile AB
Original Assignee
Saab Automobile AB
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Saab Automobile AB filed Critical Saab Automobile AB
Publication of EP0526574A1 publication Critical patent/EP0526574A1/en
Withdrawn legal-status Critical Current

Links

Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
    • F02M37/00—Apparatus or systems for feeding liquid fuel from storage containers to carburettors or fuel-injection apparatus; Arrangements for purifying liquid fuel specially adapted for, or arranged on, internal-combustion engines
    • F02M37/0047—Layout or arrangement of systems for feeding fuel
    • F02M37/0052—Details on the fuel return circuit; Arrangement of pressure regulators
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
    • F02M37/00—Apparatus or systems for feeding liquid fuel from storage containers to carburettors or fuel-injection apparatus; Arrangements for purifying liquid fuel specially adapted for, or arranged on, internal-combustion engines
    • F02M37/02—Feeding by means of suction apparatus, e.g. by air flow through carburettors
    • F02M37/025—Feeding by means of a liquid fuel-driven jet pump
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
    • F02M37/00—Apparatus or systems for feeding liquid fuel from storage containers to carburettors or fuel-injection apparatus; Arrangements for purifying liquid fuel specially adapted for, or arranged on, internal-combustion engines
    • F02M37/04—Feeding by means of driven pumps
    • F02M37/08—Feeding by means of driven pumps electrically driven
    • F02M37/10—Feeding by means of driven pumps electrically driven submerged in fuel, e.g. in reservoir
    • F02M37/106—Feeding by means of driven pumps electrically driven submerged in fuel, e.g. in reservoir the pump being installed in a sub-tank

Definitions

  • the present invention relates to a fuel system for an internal combustion engine, in which a fuel pump supplies fuel to the engine via a forward line and is arranged in a fuel chamber which is accommodated in a fuel tank and is designed with side wall and upper wall, to which fuel chamber fuel can be transferred from the fuel tank by means of an ejector which is driven by a fuel flow, produced by the fuel pump, in a return line which opens into the fuel chamber, and which upper wall is designed with an outlet.
  • the aim of the invention is to eliminate these disadvantages and to bring about a fuel system which better ensures an adequate filling of the fuel chamber at different engine loads.
  • the ejector can supply a greater quantity of fuel to the fuel chamber, the greaterthe load on the engine is. This also results in a relatively small filling of the fuel chamber via the ejector during idle running when the fuel consumption is low.
  • a fuel pump 3 supplies fuel to the engine 2 from a fuel tank 5 via a forward line 4.
  • the fuel pump 3 is arranged in a separate fuel chamber 6 which is accommodated in the fuel tank 5 and is designed with a side wall 6' and an upper wall 6". In the fuel chamber 6, the fuel level is kept so high that the fuel pump 3 cannot suck air.
  • a return line 7 for unused fuel from the engine 2 there opens on the one hand a return line 7 for unused fuel from the engine 2 and on the other hand a return line 8 which is connected to the forward line 4 and via which a part of the fuel flow from the fuel pump 3 can return to the fuel chamber 6 without passing the engine 2.
  • the return line 8 there is an ejector 9 which by means of a suction line 10 can suck up fuel from the fuel tank 5 and thus forms a pump.
  • the ejector 9 is driven by the return flow from the fuel pump 3 in the return line 8, the result of which is that both return fuel from the fuel pump and fresh fuel from the fuel tank are supplied to the fuel chamber 6 via the line section 11 of the return line 8, which line section is situated afterthe ejector 9.
  • an outlet 12 which is made up of a relatively small opening in the upper wall 6" and via which any surplus fuel in the fuel chamber 6 can flow out into the fuel tank 5. It is desirable that, when the fuel pump is in operation, there is a fuel surplus in the fuel chamber 6 in order to ensure good pump operation, and according to the invention the fuel flows to and from the fuel chamber 6 are to be dimensioned in such a manner that a fuel surplus is obtained.
  • the suction line 10 expediently opens close to the bottom of the fuel tank 5 in order to ensure good fuel supply.
  • the ejector 9 can advantageously be of the type which is known through Swedish Patent Application 8703319-7, but other embodiments are also possible.
  • the engine 2 is of the injection type and is provided with a number of injection nozzles 13. To regulate the fuel pressure as a function of the engine load, there is a pressure regulator 14. In the event of increasing engine load, increasing fuel pressure is required. In a fuel system in which the engine 2 has a fuel consumption of 2 l/h during idle running and 70 l/h during full-load running, it is possible according to the invention to use a fuel pump 3 which during idle running can produce a flow of 130 l/h and during full-load running a flow of 110 l/h, reduced on account of increased fuel pressure.
  • the forward line 4 and the return line 8 can in this connection be dimensioned in such a manner that during idle running the fuel flow from the fuel pump is divided up so that 112 l/h are supplied to the engine while 18 l/h are supplied to the return line 8, whereas on the other hand during full-load running the fuel flow from the uel pump is divided up so that 87 l/h are supplied to the engine and 23 l/h are supplied to the return pipe 8.
  • the ejector 9 will thus suck in via the suction line 10 a flow of 60 l/h during idle running and 150 l/h during full-load running.
  • the fuel chamber 6 is supplied with a total flow of 188 l/h during idle running, namely 110 l/h via the return line 7 and 78 l/h via the line section 11. Since the pump capacity during idle running is 1301/h, an outflow of 58 l/h is thus obtained via the outlet 12.
  • the fuel chamber 6 is supplied with a flow of 190 l/h during full-load running, namely 17 l/h via the return line 7 and 173 l/h via the line section 11. The outflow via the outlet 12 is then 80 l/h.
  • the ejector 9 ensures a considerably greater fuel feed into the fuel chamber 6 from the fuel tank 5 during full-load running than during idle running. This is because during full- load running both flow and pressure in the return line 8 are greater than during idle running. Moreover, a fuel surplus in the fuel chamber 6 is ensured during full-load running, while the fuel surplus in the fuel chamber 6 can be kept at a relatively low level during idle running.
  • the dimensioning of the fuel system indicated here is suitable for an engine with the selected fuel consumption, but it is of course possible, according to requirements, to dimension in another manner within the scope of the invention.

Landscapes

  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Jet Pumps And Other Pumps (AREA)
  • Cooling, Air Intake And Gas Exhaust, And Fuel Tank Arrangements In Propulsion Units (AREA)
  • Fuel-Injection Apparatus (AREA)

Abstract

Dans un système de carburant destiné à un moteur à combustion interne (2), une pompe à carburant (3) est placée dans une chambre de carburant (6) se trouvant dans un réservoir de carburant (5). Le carburant est transféré du réservoir de carburant (5) à la chambre de carburant (6) au moyen d'un éjecteur (9), lequel est commandé par un écoulement de carburant dans un conduit de retour (8), lequel est connecté à un conduit avant (4) provenant de la pompe à carburant (3) et par l'intermédiaire duquel le carburant du conduit de retour peut retourner à la chambre de carburant sans passer dans le moteur.In a fuel system for an internal combustion engine (2), a fuel pump (3) is placed in a fuel chamber (6) located in a fuel tank (5). The fuel is transferred from the fuel tank (5) to the fuel chamber (6) by means of an ejector (9), which is controlled by a flow of fuel in a return duct (8), which is connected to a front conduit (4) from the fuel pump (3) and through which the fuel from the return conduit can return to the fuel chamber without passing through the engine.

Description

Fuel system for an internal combustion engine
The present invention relates to a fuel system for an internal combustion engine, in which a fuel pump supplies fuel to the engine via a forward line and is arranged in a fuel chamber which is accommodated in a fuel tank and is designed with side wall and upper wall, to which fuel chamber fuel can be transferred from the fuel tank by means of an ejector which is driven by a fuel flow, produced by the fuel pump, in a return line which opens into the fuel chamber, and which upper wall is designed with an outlet.
In order to ensure that air does not enter the fuel system of a vehicle, it is known to arrange the fuel pump in the fuel tank of the vehicle in a separate fuel chamber which is filled up with fuel from the surrounding fuel tank. In this connection, use has been made of return fuel from the engine in order to drive an ejector which sucks fuel from the fuel tank into the fuel chamber and the fuel pump. A disadvantage of this solution, however, is that the suction capacity of the ejector decreases when the engine load increases and consequently the return flow from the engine decreases. During idle running, when the return flow from the engine is great, a considerably greater suction capacity of the ejector is obtained, however, with an unnecessarily large fuel surplus in the fuel chamber as a result.
The aim of the invention is to eliminate these disadvantages and to bring about a fuel system which better ensures an adequate filling of the fuel chamber at different engine loads.
This aim is achieved according to the invention by the fuel system being designed according to what is indicated in the characterising part of Claim 1.
It is thus achieved that the ejector can supply a greater quantity of fuel to the fuel chamber, the greaterthe load on the engine is. This also results in a relatively small filling of the fuel chamber via the ejector during idle running when the fuel consumption is low.
The invention is explained in greater detail below with the aid of the exemplary embodiment of a fuel system according to the invention, which is shown diagrammatically in the attached drawing. In a fuel system 1 designed according to the invention for an internal combustion engine 2, a fuel pump 3 supplies fuel to the engine 2 from a fuel tank 5 via a forward line 4. In order to ensure that air does not enter the fuel system, the fuel pump 3 is arranged in a separate fuel chamber 6 which is accommodated in the fuel tank 5 and is designed with a side wall 6' and an upper wall 6". In the fuel chamber 6, the fuel level is kept so high that the fuel pump 3 cannot suck air.
In the fuel chamber 6, there opens on the one hand a return line 7 for unused fuel from the engine 2 and on the other hand a return line 8 which is connected to the forward line 4 and via which a part of the fuel flow from the fuel pump 3 can return to the fuel chamber 6 without passing the engine 2. In the return line 8, there is an ejector 9 which by means of a suction line 10 can suck up fuel from the fuel tank 5 and thus forms a pump. The ejector 9 is driven by the return flow from the fuel pump 3 in the return line 8, the result of which is that both return fuel from the fuel pump and fresh fuel from the fuel tank are supplied to the fuel chamber 6 via the line section 11 of the return line 8, which line section is situated afterthe ejector 9.
At the top of the fuel chamber 6, there is an outlet 12 which is made up of a relatively small opening in the upper wall 6" and via which any surplus fuel in the fuel chamber 6 can flow out into the fuel tank 5. It is desirable that, when the fuel pump is in operation, there is a fuel surplus in the fuel chamber 6 in order to ensure good pump operation, and according to the invention the fuel flows to and from the fuel chamber 6 are to be dimensioned in such a manner that a fuel surplus is obtained.
The suction line 10 expediently opens close to the bottom of the fuel tank 5 in order to ensure good fuel supply. The ejector 9 can advantageously be of the type which is known through Swedish Patent Application 8703319-7, but other embodiments are also possible.
The engine 2 is of the injection type and is provided with a number of injection nozzles 13. To regulate the fuel pressure as a function of the engine load, there is a pressure regulator 14. In the event of increasing engine load, increasing fuel pressure is required. In a fuel system in which the engine 2 has a fuel consumption of 2 l/h during idle running and 70 l/h during full-load running, it is possible according to the invention to use a fuel pump 3 which during idle running can produce a flow of 130 l/h and during full-load running a flow of 110 l/h, reduced on account of increased fuel pressure. The forward line 4 and the return line 8 can in this connection be dimensioned in such a manner that during idle running the fuel flow from the fuel pump is divided up so that 112 l/h are supplied to the engine while 18 l/h are supplied to the return line 8, whereas on the other hand during full-load running the fuel flow from the uel pump is divided up so that 87 l/h are supplied to the engine and 23 l/h are supplied to the return pipe 8. The ejector 9 will thus suck in via the suction line 10 a flow of 60 l/h during idle running and 150 l/h during full-load running. The result is that the fuel chamber 6 is supplied with a total flow of 188 l/h during idle running, namely 110 l/h via the return line 7 and 78 l/h via the line section 11. Since the pump capacity during idle running is 1301/h, an outflow of 58 l/h is thus obtained via the outlet 12. Correspondingly, the fuel chamber 6 is supplied with a flow of 190 l/h during full-load running, namely 17 l/h via the return line 7 and 173 l/h via the line section 11. The outflow via the outlet 12 is then 80 l/h.
It thus emerges that according to the invention the ejector 9 ensures a considerably greater fuel feed into the fuel chamber 6 from the fuel tank 5 during full-load running than during idle running. This is because during full- load running both flow and pressure in the return line 8 are greater than during idle running. Moreover, a fuel surplus in the fuel chamber 6 is ensured during full-load running, while the fuel surplus in the fuel chamber 6 can be kept at a relatively low level during idle running.
In order to achieve a sufficiently good suction effect in the ejector 9, it has emerged that the flow in the return line 8 connected to the forward line 4 does not need to amount to more than 25% at the most of the flow from the fuel pump.
The dimensioning of the fuel system indicated here is suitable for an engine with the selected fuel consumption, but it is of course possible, according to requirements, to dimension in another manner within the scope of the invention.
In comparison with a previously customary solution without return line 8 and with the ejector 9 placed in the return line 7, there is achieved according to the invention, with the same capacity of the fuel pump, a better filling of the fuel chamber 6 during full-load running and a considerably reduced fuel surplus in the fuel chamber 6 during idle running.

Claims

Patent Claims
1. Fuel system for an internal combustion engine, in which a fuel pump (3) supplies fuel to the engine (2) via a forward line (4) and is arranged in a separately mounted fuel chamber (6) which is accommodated in a fuel tank (5) and is designed with side wall 6" and upper wall 6", to which fuel 5 chamber fuel can be transferred from the fuel tank (5) by means of an ejector (9) which is driven by a fuel flow, produced by the fuel pump (3), in a return line (8) which opens into the fuel chamber (6), and which upper wall 6" is designed with an outlet (12), characterised in that the return line (8) is connected to the forward line (4), a part of the fuel flow from the fuel pump o (3) being able to return through the return line (8) via the ejector (9) to the fuel chamber (6) without passing the engine (2) at the same time as surplus fuel from fuel supplied to the engine (2) via the forward line (4) is conducted back to the fuel chamber (6) via a second return line (7), the return lines (7, 8) together ensuring that the inflow to the fuel chamber (6) is greater than the 5 flow from the fuel pump (3), as a result of which a fuel surplus arises in the fuel chamber (6), which fuel surplus flows out into the tank via the outlet (12).
2. Fuel system according to Patent Claim 1, characterised in that the flow in o the return line (8) connected to the forward line (4) amounts to 25% at the most of the flow from the fuel pump (3).
EP19910909287 1990-04-27 1991-04-25 Fuel system for an internal combustion engine Withdrawn EP0526574A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
SE9001541A SE9001541L (en) 1990-04-27 1990-04-27 BURNTLE SYSTEM FOR A COMBUSTION ENGINE
SE9001541 1990-04-27

Publications (1)

Publication Number Publication Date
EP0526574A1 true EP0526574A1 (en) 1993-02-10

Family

ID=20379331

Family Applications (1)

Application Number Title Priority Date Filing Date
EP19910909287 Withdrawn EP0526574A1 (en) 1990-04-27 1991-04-25 Fuel system for an internal combustion engine

Country Status (4)

Country Link
EP (1) EP0526574A1 (en)
JP (1) JPH05508896A (en)
SE (1) SE9001541L (en)
WO (1) WO1991017355A1 (en)

Families Citing this family (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
SE470525B (en) * 1992-11-18 1994-07-04 Saab Automobile Starter systems for internal combustion engines which can be driven by different fuels
DE4241374A1 (en) * 1992-12-09 1994-06-16 Kloeckner Humboldt Deutz Ag Fuel supply system for IC engine - has throttle nozzle in fuel line located between fuel filter and injection pump
GB9415950D0 (en) * 1994-08-06 1994-09-28 Rover Group A fuel feed system for an internal combustion engine
DE19849718A1 (en) * 1998-10-28 2000-05-04 Bayerische Motoren Werke Ag Fuel delivery system
DE10003748A1 (en) * 2000-01-28 2001-08-30 Bosch Gmbh Robert Fuel supply system for internal combustion engine, with baffle pot is filled by device supplying fuel to fuel input line at least part of time

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2453733A1 (en) * 1974-11-13 1976-05-26 Volkswagenwerk Ag Stationary fuel tank arrangement - fitted with stowage housing having an upper opening with inlet channel and return pipe
DE3500718A1 (en) * 1985-01-11 1986-07-17 Robert Bosch Gmbh, 7000 Stuttgart Arrangement for feeding fuel from a storage tank by way of a feedline to the internal combustion engine of a motor vehicle
DE3510890A1 (en) * 1985-03-26 1986-10-09 Pierburg Gmbh & Co Kg, 4040 Neuss FUEL DELIVERY SYSTEM
DE3602155A1 (en) * 1986-01-24 1987-07-30 Bayerische Motoren Werke Ag Fuel system for motor vehicles
DE3612194C1 (en) * 1986-04-11 1986-10-16 Daimler-Benz Ag, 7000 Stuttgart Fuel retaining device provided in the fuel tank of a motor vehicle

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See references of WO9117355A1 *

Also Published As

Publication number Publication date
WO1991017355A1 (en) 1991-11-14
SE9001541D0 (en) 1990-04-27
SE9001541L (en) 1991-10-28
JPH05508896A (en) 1993-12-09

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