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
  • F02M63/00—Other fuel-injection apparatus having pertinent characteristics not provided for in groups F02M39/00 - F02M57/00 or F02M67/00; Details, component parts, or accessories of fuel-injection apparatus, not provided for in, or of interest apart from, the apparatus of groups F02M39/00 - F02M61/00 or F02M67/00; Combination of fuel pump with other devices, e.g. lubricating oil pump
  • F02M63/02—Fuel-injection apparatus having several injectors fed by a common pumping element, or having several pumping elements feeding a common injector; Fuel-injection apparatus having provisions for cutting-out pumps, pumping elements, or injectors; Fuel-injection apparatus having provisions for variably interconnecting pumping elements and injectors alternatively
  • F02M63/0225—Fuel-injection apparatus having a common rail feeding several injectors ; Means for varying pressure in common rails; Pumps feeding common rails
• • 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
  • F02M59/447—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 specially adapted to limit fuel delivery or to supply excess of fuel temporarily, e.g. for starting of the engine
• • 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
  • F02M2200/40—Fuel-injection apparatus with fuel accumulators, e.g. a fuel injector having an integrated fuel accumulator

Definitions

• the invention relates to an injection system for an internal combustion engine provided with a common fuel injection rail.
• Patent application US5839413 discloses a system which makes it possible to reduce the starting time of a common rail motor.
• the principle of this system consists in making the common rail communicate not only to a high pressure pump but also to a low pressure circuit thanks to two calibrated non-return valves (a first low pressure and a second high pressure).
• the low pressure circuit has a low pressure accumulator which makes it possible to maintain a stable pressure lower than that delivered when the high pressure pump is at full load.
• the low pressure circuit already compresses the fuel in the common rail. Then, when the high pressure pump exerts a pressure higher than that prevailing in the low pressure circuit, the low pressure valve, which previously allowed the low pressure flow to pass, will close in favor of the second valve.
• the common rail is finally pressurized only by the high pressure pump.
• the invention proposes an injection system of simple constitution for an internal combustion engine making it possible to shorten the starting time in order to adapt these engines to "stop and start".
• the invention relates to an injection system for an internal combustion engine comprising at least one injection means, means for supplying fuel under pressure, an accumulator common to each injection means containing pressurized fuel supplied by said supply means, characterized in that it further comprises, between each injection means and said accumulator, a pressurized fuel storage device supplied by said accumulator, said storage device being suitable for starting releasing said stored pressurized fuel to its associated injection means in order to supply pressurized fuel more quickly than with said supply means alone.
• This system makes it possible to keep the existing structure and to adapt it “stop and start” by shortening the start-up time.
• each pressurized fuel storage device comprises a first channel which, connecting said accumulator and one of said injection means, comprises at least one reservoir and at least two controlled opening means respectively located between the accumulator and the tank and between the tank and said injection means to selectively allow the tank to be filled with pressurized fuel coming from said accumulator or to empty the tank to supply said injection means.
• This configuration has the advantage of not having to install an additional compression source recovers pressurized fuel from the accumulator.
• said controlled opening means are solenoid valves.
• Each pressure fuel storage device according to the invention advantageously comprises in addition a second channel which, in parallel with the first, only allows, thanks to a non-return valve, the passage of fuel from said accumulator to said means d injection to allow the injection means to be supplied directly by said accumulator. This allows, after the start-up phases, that the injection is carried out “normally”, that is to say that each injection means is supplied by the same pressurized fuel accumulator.
• an injection system 1 intended to be used in an internal combustion engine. It mainly consists of a high pressure pump 2, a common rail 3, a storage device 4 and an injector 5. A single injector 5 is visible but of course, the common rail 3 may by example supply as much injector 5 as cylinders present in the engine.
• the high pressure pump 2 supplies the common rail 3 with pressurized fuel. This widely used and well-known configuration will not be described in more detail in this patent.
• the storage device 4 connects the common rail 3 and the injector 5 by two channels 6, 7 joining before arriving at the injector 5.
• the first channel 6 is provided with a non-return valve 8, preventing the flow of fuel from passing from the injector 5 to the common rail 3 but allowing the reverse flow.
• the second channel 7 includes a reservoir 9, a pressure sensor 10 and two solenoid valves 11, 12. In the example illustrated in FIG. 1, the latter 11, 12, located respectively on either side of the reservoir 9, selectively and independently of one another open part of the channel 7. The sensor 10 detects the pressure prevailing in the reservoir 9.
• the senor 10 When the engine is started for the first time, the tank 9 being empty, the sensor 10 indicates that there is no pressure. The solenoid valve 10 is then put in its open position and the second 11 in its closed position. When the high pressure pump 2 supplies the common rail 3 with pressurized fuel, fuel will pass through the channel 6 and the channel 7 of each storage device 4 associated with an injector 5.
• the solenoid valve 1 0 being open, the fuel will then be introduced into the tank 9 without being able to go any further, the solenoid valve 11 being closed.
• the fuel which is in the channel 6 passes through the non-return valve 8 and thus feeds the injector 5.
• the high pressure pump 2 will gradually increase the pressure to provide, after a moment, a pressure high enough to reach the minimum operating pressure of the injectors 5.
• a pressure sensor (not shown) located in each injector 5 makes it possible to determine said minimum pressure and then controls the injection. The engine can then be started.
• the sensor 10 of the storage device 4 in the same way detects whether the necessary pressure in the tank 9 (which may be much higher than that mentioned in the previous paragraph) is reached.
• the solenoid valve 10 at this time will be put in its closed position and will therefore trap pressurized fuel in the tank 9. The engine is now ready to operate in "stop and start” mode.
• the solenoid valve 1 2 When the start control is actuated again and the sensor 1 0 detects pressure, the solenoid valve 1 2 is placed in the open position and therefore releases the pressurized fuel to its associated injector 5. In Indeed, the non-return valve 8 prevents this fuel from going up along the channel 6 towards the common rail 3.
• the high pressure pump 2 being partially supplied with energy by the engine timing belt (not shown), the starting of the latter will have an accelerating effect on the rise in pressure of the high pressure pump 2. The shortening of the starting will therefore to be further multiplied.
• the high pressure pump 2 will supply a higher pressure in the common rail 3 compared to that prevailing at the inlet of the injector 5.
• the non-return valve 8 will then let the fuel s '' flow through the channel 6 to the injector 5.
• the solenoid valve 12 is returned to the closed position and then the solenoid valve 11 is reopened.
• the normal fuel injection cycle can then take place.
• the solenoid valve 11 closes and traps fuel under pressure in the tank 9 again.
• the restart cycle cited and repeated several times allows, thanks to this injection system, a motor with a common ramp to operate in "stop and start".
• the fact that there is a storage device 4 for each injector 5 allows a small volume of reservoir 9 compared to that of the common rail 3.
• the reservoir 9 will preferably be dimensioned so that two injections can be carried out before the pump high pressure 2 takes over.
• the present invention is not limited to the example illustrated but is susceptible to various variants and modifications which will appear to those skilled in the art.
• configurations of channel 7 with a single solenoid valve or a technology different from the solenoid valves can be envisaged.
• the strategy of the first start can be different, for example by filling the reservoir 9 only after a few injections.

Landscapes

• Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Combustion & Propulsion (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Fuel-Injection Apparatus (AREA)
• Cylinder Crankcases Of Internal Combustion Engines (AREA)

Priority Applications (3)

Applications Claiming Priority (2)

Publications (1)

Family

ID=8869505

Family Applications (1)

Country Status (5)

Citations (4)

Family Cites Families (1)

• 2001
  • 2001-11-19 FR FR0114896A patent/FR2832462B1/fr not_active Expired - Fee Related
• 2002
  • 2002-11-07 WO PCT/FR2002/003806 patent/WO2003044360A1/fr not_active Application Discontinuation
  • 2002-11-07 EP EP02803432A patent/EP1448887B1/de not_active Expired - Lifetime
  • 2002-11-07 AT AT02803432T patent/ATE292755T1/de not_active IP Right Cessation
  • 2002-11-07 DE DE60203643T patent/DE60203643T2/de not_active Expired - Lifetime

Patent Citations (4)

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