WO2014063715A1 - Système d'injection de carburant - Google Patents

Système d'injection de carburant Download PDF

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Publication number
WO2014063715A1
WO2014063715A1 PCT/EP2012/004417 EP2012004417W WO2014063715A1 WO 2014063715 A1 WO2014063715 A1 WO 2014063715A1 EP 2012004417 W EP2012004417 W EP 2012004417W WO 2014063715 A1 WO2014063715 A1 WO 2014063715A1
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WO
WIPO (PCT)
Prior art keywords
fuel
return
working chamber
leakage
pressure
Prior art date
Application number
PCT/EP2012/004417
Other languages
English (en)
Inventor
Sergi Yudanov
Original Assignee
Volvo Lastvagnar Aktiebolag
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 Volvo Lastvagnar Aktiebolag filed Critical Volvo Lastvagnar Aktiebolag
Priority to PCT/EP2012/004417 priority Critical patent/WO2014063715A1/fr
Publication of WO2014063715A1 publication Critical patent/WO2014063715A1/fr

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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
    • F02M55/00—Fuel-injection apparatus characterised by their fuel conduits or their venting means; Arrangements of conduits between fuel tank and pump F02M37/00
    • F02M55/002—Arrangement of leakage or drain conduits in or from injectors
    • 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
    • F02M59/00—Pumps specially adapted for fuel-injection and not provided for in groups F02M39/00 -F02M57/00, e.g. rotary cylinder-block type of pumps
    • F02M59/02—Pumps specially adapted for fuel-injection and not provided for in groups F02M39/00 -F02M57/00, e.g. rotary cylinder-block type of pumps of reciprocating-piston or reciprocating-cylinder type
    • F02M59/10—Pumps specially adapted for fuel-injection and not provided for in groups F02M39/00 -F02M57/00, e.g. rotary cylinder-block type of pumps of reciprocating-piston or reciprocating-cylinder type characterised by the piston-drive
    • F02M59/102—Mechanical drive, e.g. tappets or cams
    • 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
    • F02M59/00—Pumps specially adapted for fuel-injection and not provided for in groups F02M39/00 -F02M57/00, e.g. rotary cylinder-block type of pumps
    • F02M59/20—Varying fuel delivery in quantity or timing
    • F02M59/36—Varying fuel delivery in quantity or timing by variably-timed valves controlling fuel passages to pumping elements or overflow passages
    • F02M59/366—Valves being actuated electrically
    • 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
    • F02M59/00—Pumps specially adapted for fuel-injection and not provided for in groups F02M39/00 -F02M57/00, e.g. rotary cylinder-block type of pumps
    • F02M59/44—Details, components parts, or accessories not provided for in, or of interest apart from, the apparatus of groups F02M59/02 - F02M59/42; Pumps having transducers, e.g. to measure displacement of pump rack or piston
    • 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
    • F02M59/00—Pumps specially adapted for fuel-injection and not provided for in groups F02M39/00 -F02M57/00, e.g. rotary cylinder-block type of pumps
    • F02M59/44—Details, components parts, or accessories not provided for in, or of interest apart from, the apparatus of groups F02M59/02 - F02M59/42; Pumps having transducers, e.g. to measure displacement of pump rack or piston
    • F02M59/442—Details, components parts, or accessories not provided for in, or of interest apart from, the apparatus of groups F02M59/02 - F02M59/42; Pumps having transducers, e.g. to measure displacement of pump rack or piston means preventing fuel leakage around pump plunger, e.g. fluid barriers
    • 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
    • F02M2200/00—Details of fuel-injection apparatus, not otherwise provided for
    • F02M2200/95—Fuel injection apparatus operating on particular fuels, e.g. biodiesel, ethanol, mixed fuels
    • F02M2200/953—Dimethyl ether, DME

Definitions

  • This invention relates to a fuel system for supplying pressurised fuel to a combustion chamber of an internal combustion engine.
  • the fuel system comprises a fuel pump having a fuel pump inlet and at least one pumping plunger with its working chamber, and at least one fuel injector configured to inject pressurised fuel from the fuel pump to the combustion chamber.
  • the invention further relates to a method for supplying pressurised fuel to a combustion chamber of an internal combustion engine.
  • the system is particularly suitable for use with volatile alternative fuels such as DME.
  • the invention further relates to a method for supplying pressurised fuel to a combustion chamber of an internal combustion engine.
  • Volatile alternative fuels such as DME
  • DME Volatile alternative fuels
  • a lubricity improving additives to reduce mechanical wear in fuel injection systems.
  • a small amount of engine oil may find its way into the fuel.
  • alternative fuels may not be stable enough chemically when subjected to elevated temperatures and/or worked upon mechanically with a relatively high energy transfer, or may present an environment making the additives and impurities in the fuel less chemically stable. Any one of these factors or their combinations may lead to formation of undesired residue in the fuel system, adversely affecting the function of its elements.
  • elements of the low-pressure part of the system are in this case most vulnerable, such as filters that get clogged up by the deposits or low-pressure valves that lose their free-moving ability or get stuck altogether. Clogged filters would in turn prevent normal fuel delivery to engine and cause power loss, while the valves would not properly perform their control functions.
  • elements of the high-pressure part of the system may be much less vulnerable to residue formation, because the relatively high flow energies and relatively strong forces that act on high-pressure valves would destroy the residue layers or prevent their formation in these parts of the fuel injection system.
  • the return line is connected to the conventional inlet port of the high- pressure pump instead, other problems may occur.
  • the fuel in the return line is normally much hotter than the fuel in the low-pressure part of the system, because it passes through the hottest areas of the installation and because the high-pressure leakage generates heat.
  • the return line is also usually kept at a relatively high pressure to keep the fuel in the return line of the injectors liquid to stabilise their performance, normally about 30 - 60 bar.
  • An object of the present invention is to provide an inventive fuel system in which the previously mentioned problems are at least partly avoided. This object is achieved by the features of claim 1 or 24.
  • the invention concerns a fuel system for supplying pressurised fuel to a combustion chamber of an internal combustion engine.
  • the fuel system comprises a fuel pump having a fuel supply inlet and at least one pumping plunger with its working chamber, and at least one fuel injector configured to inject pressurised fuel from the fuel pump to the combustion chamber.
  • the invention is characterized in that said fuel system further comprising at least one return line configured for returning fuel leakage back to said working chamber, and a return flow control arrangement configured to control a fuel return flow in said at least one return line to said working chamber, such that said at least one plunger can draw fresh fuel from said fuel supply inlet during a majority of its filling stroke.
  • major of its filling stroke should be interpreted as at least 50% of its filling stroke, specifically at least 80% of its filling stroke, and especially at least 90% of its filling stroke.
  • a relatively hot volatile fuel that is kept under an elevated pressure in the return line is prone to significant expansion upon release to a volume with a relatively low pressure such as the volume located at the inlet of the HP pump, which may disrupt proper filling of the HP pump with fresh fuel.
  • the present invention at least partly solves this problem by providing a return flow control arrangement that is configured to control a fuel return flow from the fuel return line to the working chamber.
  • the return flow control arrangement opens and closes a fuel flow path at the end of the filling stroke when the plunger is at or around its bottom dead centre, so that the fresh fuel may be filled through the inlet valve of the plunger in a normal way until just before opening of the return flow control arrangement, at which time the pressurised fuel from the return line escapes into the plunger filling volume, the latter being at a lower pressure due to that the fuel that has just been filled through the inlet valve is both relatively cold and that it lost some of its already relatively low pressure, as found at the fuel supply side of the HP pump, when flowing through the restrictions of the inlet valve and a fuel pump volume control valve.
  • the return flow control arrangement closes the fuel flow path in the beginning of the pumping stroke, and then pressurises the fresh fuel mixed with the returned fuel and displaces it out to the fuel injector for delivery into the engine.
  • the fuel coming from the hotter and highly pressurised parts of the fuel system is not mixed up with the low-pressure system's fuel but instead is "recycled" back into the high-pressure side of the system, where most of it is eventually burned off in the engine.
  • the return line may receive fuel leakage from said at least one fuel injector, and/or from said high-pressure pump, and/or from a low-pressure volume of said high-pressure pump housing, and/or from a leakage volume associated with a sealing arrangement of said high-pressure pump.
  • a first return line may receives fuel leakage from said at least one fuel injector and an additional return line may receive fuel leakage from said high-pressure pump, wherein both said return lines are connected to the same fuel return port.
  • the leakage that flows past the clearance of the plunger in the high-pressure pump can be directed into the same fuel return port as the injector leakage, and "recycled" in the system to be burned in the engine as described above.
  • Leakage from the sealing arrangement at the driveshaft-to-housing interface of the pump may advantageously also be recycled into the working chamber. Leakage from different leakage sources may also be conveyed via individual return lines either to the same or to individual working chambers.
  • the high-pressure pump may have several plungers each with its own inlet valve, working chamber and fuel return port, and the different return lines and/or their combinations may be connected to their respective separate plungers, in order to be able to arrange for different pressure discharge conditions in the different return lines.
  • the typical pressure in the high-pressure pump's leakage return line may need to be maintained lower than the typical pressure in the injector return line. This is because the pressure in the leakage return line of the high-pressure pump is typically prevented from escaping either to the housing of the pump or to the outside of the pump by a seal, and the lower the pressure differential that the seal is exposed to the better its service life.
  • the leakage rate from the high-pressure pump may be less than the leakage rate coming through the injector return line, therefore even in case a back-pressure regulating valve is installed in the injector return line which maintains a relatively high pressure upstream and a lower pressure downstream the valve, that downstream pressure that is then transmitted to the respective fuel return port may still be too high than the desired pressure in the return line of the high-pressure pump.
  • a leakage volume downstream the seal may also be coupled via its own respective return line to a separate plunger with its fuel return port, such that any leakage that may penetrate through the seal is also "recycled” back into the high-pressure part of the fuel system.
  • a typical embodiment of the high-pressure pump according to this would have an intermediate seal designed to operate at a relatively high pressure and an additional seal designed to operate at a relatively low pressure, wherein the leakage volume between the seals would be routed to one plunger with its fuel return port and the volume downstream the additional seal would be routed to an engine air inlet. In this way, the additional seal would be operating at a lower pressure and could therefore ensure a better sealing properties over a longer service life, for instance by the use of a softer sealing material.
  • the abovementioned different pressure discharge conditions from the different return lines into the respective working chambers may also be arranged by setting different hydraulic restrictions in the respective inlet valves. If a lower resistance to pressure discharge is required, for example for the return line of the high-pressure pump, then a higher hydraulic restriction is set for the inlet valve that supplies fuel from the inlet to the working chamber with which said return line is associated.
  • the hydraulic restriction of the inlet valve can be varied in many different ways known in the art, for example by setting a different spring opening pressure of the valve.
  • Yet another possible aspect may include a plunger actuation mechanism of the high-pressure pump that is configured in such a way that the velocity of the retraction of the plunger during its filling stroke is made to vary in order to achieve a slower velocity and therefore a lower pressure drop across the inlet valve during the periods of normal filling by the fresh fuel, but an higher velocity in other parts of the filling stroke when it is advantageous to lower the working chamber pressure for better discharge of fuel from the return line to the working chamber.
  • a flow control valve may be installed between the return line and the working chamber of the plunger to control the fluid flow in the return line to the working chamber.
  • a separate flow control valve By means of a separate flow control valve, the location of the fuel return port associated with each working chamber is no longer decisive for the opening and closing timing of the return flow control arrangement, as it is when the plunger and fuel return port jointly functions as the return flow control arrangement.
  • the provision of a flow control valve thus allows an increased freedom of location of the fuel return port, including locations of the working chamber outside the operating area of the plunger.
  • the fuel leakage return line may even by connected to the conventional fuel inlet of the working chamber and thus outside the working chamber, such that the fuel return port and conventional fuel inlet port are formed by a single inlet port.
  • the location of said fuel return connection must however always be arranged downstream the one-way inlet valve associated with each plunger, because the one-way inlet valve effectively prevents the returned fuel from expanding into the low-pressure supply part of the fuel pump, namely in the region of the inlet metering valve and upstream the inlet valves.
  • the operation of the flow control valve is advantageously synchronised with the timing of the filling and pumping strokes of the plunger, such that its opening corresponds to desired pressure conditions in the working chamber for evacuation of pressurised fuel from the return line.
  • the plunger itself as the valve for opening and closing the fuel flow path between the return line and the working chamber, there may be advantages in configuring the fuel injection system to have a separate flow control valve as described, controlled for example electronically by an engine management system.
  • a method for supplying pressurised fuel to a combustion chamber of an internal combustion engine comprises a fuel pump having at least one pumping plunger with its working chamber, and at least one fuel injector configured to inject pressurised fuel from the fuel pump to the combustion chamber.
  • the method comprises the step of timing a return of fuel leakage back to the working chamber so that the at least one plunger can draw fresh fuel from a fuel supply inlet into said working chamber during a majority of its filling stroke.
  • fresh fuel from a fuel tank may be filled through a conventional inlet valve of the plunger in a normal way until just before opening of the fuel return port, at which time the hot pressurised fuel from the return line may escape into the plunger filling volume.
  • fuel coming from the hotter and highly pressurised parts of the fuel system is allowed to enter and rapidly filling the lower pressurized working chamber with fuel vapour already at an early stage of the filling cycle, which would effectively prevent additional fresh fuel from entering the working chamber.
  • Figure 1 shows a first embodiment of the fuel system according to the invention
  • Figure 2 shows a second embodiment of the fuel system according to the invention
  • Figure 3 shows a third embodiment of the fuel system according to the invention
  • Figure 4 shows a fourth embodiment of the fuel system according to the invention
  • Figure 5 shows a fifth embodiment of the fuel system according to the invention.
  • FIG. 1 shows a first embodiment of the fuel system 1 according to the invention.
  • the fuel system 1 is particularly suitable for supplying pressurised volatile fuel, such as dimethyl ether (DME) or a blend thereof, to an internal combustion engine, but the fuel system 1 is also suitable for other fuels.
  • the fuel system 1 typically comprises a low-pressure fuel system 2 incorporating a fuel tank 3 from which a low-pressure fuel pump 4 draws fuel via a filter (not shown) and supplies it to an inlet 5 of a high-pressure fuel pump 6, and a drain passage 7 with a restriction 8 for returning recirculated low-pressure fuel back to the tank 3.
  • HP pump 6 The high-pressure fuel pump 6, hereinafter referred to as HP pump 6, is in many ways formed as a conventional "common rail" fuel pump that comprises an inlet metering valve 9 receiving fuel from the inlet 5.
  • the inlet metering valve (IMV) 9 controls the amount of fuel that is allowed to reach an inlet valve 10, which resembles in its design a check valve and is installed with its outlet connected to a working chamber 11 of a first plunger 12.
  • the HP pump 6 also comprises a housing 13 in which the first plunger 12 is arranged to expand and contract the working chamber 11 in a reciprocating motion actuated by a corresponding drive mechanism 14.
  • fuel from the inlet 5 is drawn via the inlet valve 10 into the working chamber 11 upon its expansion, and supplied at a high pressure upon contraction of the working chamber by the first plunger 12 to at least one fuel injector 15 of the engine (not shown) via an outlet valve 16.
  • An internal leakage in the injector 15, such as a control leakage, is collected into a first return line 17 and is led away from the injector 15 via a relief valve 8.
  • the relief valve is set to maintain a relatively high pressure in the part of the return line 17 which is upstream of the relief valve 18, in order to keep the fuel in liquid form and avoid possible instability in injector operation that may be caused by fuel vaporisation at a lower pressure.
  • the fuel pressure in the fuel tank 3 typically is in the range of 0 - 15 bar, largely depending on the fuel temperature.
  • the low-pressure fuel pump 4 typically increases the fuel pressure in a range of about 10 - 40 bar.
  • the fuel pressure at the inlet metering valve 9 and the inlet valves 10 is thus typically about 10 - 55 bar, but when the plunger retracts the fuel pressure quickly drops to vapour pressure.
  • the fuel pressure within the common rail is normally about 200 - 350 bar depending on engine speed, but fuel pressure up to 600 bar or more may be used.
  • the fuel pressure at the relief valve is about 30 - 60 bar, and within a low-pressure volume 20 of the housing normally below 5 bar, and more specifically below 1 bar.
  • the plunger 12, 25, 29 can draw fresh fuel from the fuel supply inlet during a majority of its filling stroke. This configuration ensures a certain pumping efficiency and avoids the risk of engine halt due to fuel vapour choking of the high-pressure fuel pump upon feeding the fuel pump with hot returned pressurised DME or similar to an fuel pump inlet or other regions upstream the inlet valve 10.
  • the HP pump further comprises a fuel return port 19 located in a wall of the working chamber 1 .
  • the fuel return port is positioned to enable a fuel flow path between the return line to the working chamber 11 depending on the position of the first plunger 12.
  • the fuel return port 19 is preferably positioned such that the first plunger 12 opens the fuel flow path when at or around its bottom dead centre. In this way, the first plunger 12 can draw fresh fuel from the inlet 5 during a majority of its filling stroke and then at the end of this stroke and the beginning of the pumping stroke allow the fuel from the first return line 17 via the fuel return port 19 to be discharged into the working chamber 11.
  • Optimal filling of fresh and leaked fuel depends on many factors such as pressure and temperature of fresh and leaked fuel, plunger speed and fuel leakage flow rate. Too early opening of the fuel return port results in significantly reduced filling of fresh fuel, whereas to short opening prevents sufficient fuel return flow.
  • the low-pressure volume 20 of the housing 13 is connected, via a channel 37 and an oil separator 21 , to the inlet of engine (not shown) in order to prevent oil dilution in the low-pressure volume 20 by the fuel that may leak into it past the clearance in the plunger 12.
  • the low-pressure volume 20 may also be protected from overpressure by a relief valve 22 as shown in Fig.1.
  • a sealing arrangement comprising a seal 24 is provided at a driveshaft-to- housing interface of said high-pressure pump 6. The sealing arrangement serves to prevent lubrication oil and fuel vapour from leaking out of the low- pressure volume 20.
  • the fuel system 1 eliminates return of a hot and mechanically strained fuel, as well as fuel that may be mixed with lube oil, back into the low-pressure fuel system, while still managing the return of the leakage in a way that does not require expensive modification of the fuel system as a whole.
  • Fig. 2 shows schematically a second embodiment of the invention that is similar to the first embodiment, differing in that there is an additional return line 23 for collecting leakage from the low-pressure volume 20 of the HP pump 6.
  • the additional return line 23 is connected to the fuel return port 19, while a driveshaft-to-housing interface of the low-pressure volume 20 is sealed from the outside ambient conditions by a seal 24.
  • a one-way valve 40 may be installed in the additional return line 23 for preventing the higher pressure in the first return line 17 from forcing the fuel from the first return line 17 into the low-pressure volume 20 and increasing the pressure there, as well as preventing fuel from being pushed back during a compression stroke of the plunger 12.
  • Fig.3 shows schematically a third embodiment of the invention, that is similar to the previously described embodiments but in which a second plunger 25, together with its second inlet valve 26, a second working chamber 27 and a second fuel return port 28, is used to control the pressure in the second return line 23 that collects the leakage from the low-pressure volume 20 of the HP pump housing.
  • the embodiment according to Fig.3 gives the advantage of having the possibility to control the pressure in the second return line 23 to a lower level than that in the first return line 17. This may be advantageous for achieving a long service life of the seal 24 and for simplifying its design.
  • Fig.4 shows schematically a fourth embodiment of the invention, that is similar to the previously described embodiments but in which a third plunger 29, with its third inlet valve 30, third working chamber 31 and third fuel return port 32, is used to control the pressure in a third return line 33.
  • the sealing arrangement comprises an intermediate seal 34, a downstream leakage volume 35 that is sealed from the outside ambient conditions by an additional seal 36, and an additional leakage volume that is connected to the engine air inlet via channel 37.
  • the third return line 33 is connected to said third fuel return port 32 and receives fuel leakage that may get past the intermediate seal 34. Most of the leakage downstream the intermediate seal 34 is contained in the leakage volume 35.
  • the embodiment works in a similar way as the embodiments previously described, with the advantage of a reduced quantity of fuel that is carried away from the HP pump (either to the engine's inlet or the atmosphere).
  • the individual inlet valves 10, 26, 30 associated with the plungers 12, 25, 29 may exhibit different hydraulic restrictions, in order to adjust the resulting pressure in the respective working chamber11 , 27, 31 to a particular return line that it is associated with. If a lower resistance to pressure discharge is required, for example for the return line 23 of the HP pump 6 as shown in Fig.3, then a higher hydraulic restriction is set for the inlet valve 26 that supplies fuel from the inlet 5 to the working chamber 27 with which said return line is associated. This makes the pressure in the working chamber 27 to be lower at the time of the opening of its fuel return port 28, so that a bigger volume of fuel can be discharged from the return line 23 into the working chamber 27 and, correspondingly, a lower pressure can be maintained in that return line 23.
  • the hydraulic restriction of the inlet valve 26 can be varied in many different ways known in the art, for example by setting a different spring opening pressure of the inlet valve 26.
  • a plunger actuation mechanism 14 of the HP pump 6 may be configured in such a way that the velocity of the retraction of the plunger 12 during its filling stroke is made to vary in order to achieve a slower velocity and therefore a lower pressure drop across the inlet valve 10 during the periods of normal filling by the fresh fuel, but an higher velocity in other parts of the filling stroke when it is advantageous to lower the working chamber pressure for better discharge of fuel from the return line 17 to the working chamber 11.
  • FIG.5 incorporates a flow control valve 38 installed in the return line 17 between the working chamber 11 and the fuel injector 15 to control the fuel flow path in the return line 17 to the working chamber 11.
  • the operation of the flow control valve 38 is preferably synchronised with the timing of the filling and pumping strokes of the plunger 12, such that the opening of the flow control valve 38 corresponds to desired pressure conditions in the working chamber 11 for evacuation of pressurised fuel from the return line 17.
  • the flow control valve 38 can be controlled for example electronically by an engine management system (not shown), and the outlet 39 of the flow control valve 38 can also be placed such that its area is never affected by the plunger 12.
  • Variations of the fuel system according to the invention should not be interpreted as limited to exactly said embodiment, but said variations may be applied to other embodiments as well when not inconsistent with each other.
  • the embodiments according to Fig.1 or 2 can incorporate the additional components of the forth embodiment in whole or in part, such that for example the first embodiment may have the additional seal and the leakage volume and have the channel 37 connecting to that leakage volume instead of connecting to the low- pressure volume 20.
  • the fuel system is disclosed using an in-line HP fuel pump with three plungers 12, 25 and 29, but the fuel system is equally able to have less or more plungers.
  • Other obvious additions and their combinations can also be used to enhance the system's performance.
  • there may be several fuel return ports associated with a single plunger which may be configured to be opened with different duty cycles in order to handle different flow and pressure conditions in the respective return lines of the system.
  • the fuel return port may also be located upstream the working chamber, but not upstream the one-way inlet valve.

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  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Fuel-Injection Apparatus (AREA)

Abstract

L'invention concerne un système d'alimentation en carburant (1) destiné à alimenter en carburant sous pression une chambre de combustion d'un moteur à combustion interne. Ledit système d'alimentation en carburant comprend une pompe à carburant (6) qui comporte un orifice d'alimentation en carburant (5) et au moins un piston-plongeur de pompage (12, 25, 29) ayant sa chambre de travail (11, 27, 31), et au moins un injecteur de carburant (15) configuré pour injecter un carburant sous pression depuis ladite pompe à carburant (6) jusque dans ladite chambre de combustion. Ledit système d'alimentation en carburant comprend en outre au moins une conduite de retour (17, 23, 33) configurée pour renvoyer la fuite de carburant vers ladite chambre de travail (11, 27, 31), et un système de régulation d'écoulement de retour (12, 25, 29, 19, 28, 32, 38) configuré pour réguler un écoulement de retour de carburant dans ladite ou lesdites conduites de retour (17, 23, 33) jusqu'à ladite chambre de travail (11, 27, 31), de telle sorte que ledit ou lesdits pistons-plongeurs (12, 25, 29) puissent pomper du carburant frais dudit orifice d'alimentation en carburant (5) pendant une grande partie de la course de remplissage.
PCT/EP2012/004417 2012-10-22 2012-10-22 Système d'injection de carburant WO2014063715A1 (fr)

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Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2018155221A (ja) * 2017-03-21 2018-10-04 いすゞ自動車株式会社 内燃機関の燃料噴射装置
US10578083B2 (en) 2015-05-07 2020-03-03 Volvo Truck Corporation Fuel pump assembly
US10774775B2 (en) 2016-07-05 2020-09-15 Ford Global Technologies, Llc Direct-injection, supercharged internal combustion engine with high-pressure fuel pump, and method for operating an internal combustion engine of said type
CN113260782A (zh) * 2018-12-20 2021-08-13 雷诺股份公司 燃料供应装置

Citations (4)

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Publication number Priority date Publication date Assignee Title
GB2263317A (en) * 1992-01-16 1993-07-21 Diesel Tech Co Common rail injection system.
WO2003018991A1 (fr) * 2001-08-25 2003-03-06 Robert Bosch Gmbh Système d'injection de carburant pour moteur à combustion interne
EP2143916A1 (fr) 2008-07-07 2010-01-13 Teleflex GFI Europe B.V. Système d'injection à deux carburants et véhicule automobile comprenant un tel système d'injection
DE102009052601A1 (de) * 2009-11-10 2011-05-12 Daimler Ag Kraftstoffeinspritzanlage

Patent Citations (4)

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DE102009052601A1 (de) * 2009-11-10 2011-05-12 Daimler Ag Kraftstoffeinspritzanlage

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US10578083B2 (en) 2015-05-07 2020-03-03 Volvo Truck Corporation Fuel pump assembly
US10774775B2 (en) 2016-07-05 2020-09-15 Ford Global Technologies, Llc Direct-injection, supercharged internal combustion engine with high-pressure fuel pump, and method for operating an internal combustion engine of said type
JP2018155221A (ja) * 2017-03-21 2018-10-04 いすゞ自動車株式会社 内燃機関の燃料噴射装置
CN113260782A (zh) * 2018-12-20 2021-08-13 雷诺股份公司 燃料供应装置

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