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
  • F02M53/00—Fuel-injection apparatus characterised by having heating, cooling or thermally-insulating means
  • F02M53/04—Injectors with heating, cooling, or thermally-insulating means
  • F02M53/08—Injectors with heating, cooling, or thermally-insulating means with air cooling
• • 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
  • F02M53/00—Fuel-injection apparatus characterised by having heating, cooling or thermally-insulating means
  • F02M53/04—Injectors with heating, cooling, or thermally-insulating means
  • F02M53/043—Injectors with heating, cooling, or thermally-insulating means with cooling means other than air cooling
• • 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
  • F02M55/02—Conduits between injection pumps and injectors, e.g. conduits between pump and common-rail or conduits between common-rail and injectors
  • F02M55/025—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
  • 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
  • F02M63/06—Use of pressure wave generated by fuel inertia to open injection valves

Definitions

• the invention relates to a method for fuel injection in Melj cylmder-Krafrinascriinen by generating a fuel pressure to deliver the fuel in a flywheel line for the use of the pressure surge principle by means of a shut-off valve in the flywheel line, each injector associated with a shutoff valve being supplied with the pressure surge and not the Fuel passing through the injection nozzle is fed back through the open shut-off valve via a return line in front of the fuel pump, and a device for carrying out the process.
• Technical solutions of this kind are required above all for fuel injection in internal combustion engines.
• Preferred areas of application are multi-cylinder gas engines with diesel pilot injection, multi-cylinder diesel engines, multi-cylinder gasoline engines and multi-cylinder engines for the use of alternative fuels.
• Merirzylmder engines are predominantly equipped with fuel pumps that are driven by camshafts.
• the fuel dose supplied to the working cylinders has a marked speed dependency with regard to the droplet size and the length of the fuel jet.
• the injection period 40 ms.
• the injection duration is only a maximum of 2 ms per injection period, which corresponds to an energetic utilization rate of at most 5%.
• the object of the invention is therefore to overcome the disadvantages of the known prior art.
• the aim is to achieve a technical solution that offers prerequisites for improving the mass / performance and price / performance ratio in the manufacture of multi-cylinder motor vehicles with a high level of energy efficiency and low mechanical expenditure.
• the object is essentially achieved by the protective features of claims 1 and 10.
• the method for fuel injection in multi-cylinder Kraff machines is characterized in that essentially a single fuel pump delivers the fuel with a pre-pressure into a pre-pressure railchamber common to several engine cylinders, the pre-pressure corresponding to only a fraction of the required injection pressure.
• the fuel is transferred from the pre-pressure railchamber via pressure relief valves to the return railchamber common to several engine cylinders.
• So-called flywheels with shut-off valves are provided between the pre-pressure railchamber and the return railchamber, with one swing line between the pre-pressure railchamber and the return railchamber being used for each shut-off valve.
• At least one injector is actuated in the respective swing line.
• the pressure surge that occurs when a shut-off valve is closed is used for metering the fuel via the respective injection nozzle.
• the fuel flowing back when the shut-off valve is open is conveyed into the return railchamber common to several engine cylinders.
• the pressure conditions in the pre-pressure railchamber and in the return railchamber are kept constant by simple means, so that optimal flow conditions can be guaranteed in the flywheels over the entire speed range.
• the shut-off valves are actuated, the pressure surge required for fuel injection in the respective flywheel lines is generated via the injection nozzles connected to the respective flywheel line.
• the method is characterized in that the energy of the fuel stored in the return railchamber is used for the fuel delivery system. This leads to an additional favorable influencing of the energy expenditure for the provision of the required fuel pre-pressure in the pre-pressure railchamber.
• the swing line can be operated in conjunction with devices for vibration damping. This prevents undesirable impairments of the fuel delivery system.
• the pre-pressure Railchamber It is also possible to use several fuel pumps to produce the pre-pressure in the pre-pressure Railchamber.
• the number of fuel pumps to be operated can be selected in accordance with the respective engine load requirements.
• the swing line, shut-off valve, vibration damper and injection nozzle can be combined in one high-pressure unit per working cylinder. If necessary, this high-pressure unit can be operated with a jacket in a thermally insulated manner from the engine and can be cooled by a cooling medium integrated in the jacket.
• shut-off valves in the flywheel lines of the injection system for multi-cylinder engines electro-magnetically.
• the technical solution is also characterized by a device consisting of fuel pumps, flywheels with shut-off valves and return lines to the fuel supply system.
• a pre-pressure railchamber common to a cylinder group or to all cylinders of the multi-cylinder power circuit is arranged between at least one fuel pump and at least one flywheel line.
• a common return railchamber for a cylinder group or for all cylinders of the multi-cylinder engine ascliine is arranged between the upstream and the return railchamber.
• the flywheel line, shut-off valve, injection nozzle and, if necessary, vibration damper are arranged in a common high-pressure module.
• one or more injection nozzles can be arranged between the upstream railchamber and the return railchamber.
• the shut-off valve and the injection nozzles of a high-pressure unit can be structurally arranged in a common component or in several components connected by lines.
• an embodiment of the device is characterized in that one or more fuel pumps are arranged on the pre-pressure rail chamber.
• the common pre-pressure railchamber for one cylinder group or for all cylinders of the multi-cylinder engine and the return railchamber common for one cylinder group or for all cylinders of the multi-cylinder Kjafm machine are provided as two chambers in a common structural unit to execute. If necessary, when designing the upstream and return railchambers as two chambers of a common railchamber, one or more pressure-limiting valves ensuring the hysteresis and vibration-free keeping of the upstream pressure are arranged in the partition between the chambers.
• the arrangement of the high-pressure module in a thermally insulating sleeve is advantageous. If required, this sleeve can also be operated with a cooling medium and for this purpose has a cooling medium inlet and a cooling medium outlet.
• the advantages of the invention are that it provides a high pressure which is independent of the speed, but which is not generated continuously but only in connection with an immediate fuel injection process.
• the invention makes it possible to combine the design and control of the fuel injection system according to the invention with the advantageous properties of a modern common rail.
• a common pre-pressure railchamber for all or for individual groups of working cylinders of a multi-cylinder engine as well as controlled valves are operated in direct functional connection with injection nozzles.
• a decisive advantage of the solution found is that only a part of about a tenth of the required maximum pressure has to be constantly provided in the pre-pressure railchamber and that the maximum pressure is only a brief pressure wave immediately before fuel metering via the injection nozzle by controlling the respective shut-off valve in front of one individual or a group of injection nozzles.
• the system is composed of a pre-pressure module, the pressure supply system, and high pressure modules.
• the high pressure required is generally 8 to 10 times the pre-pressure.
• the technical solution according to the invention is implemented in that a pressure accumulator is loaded by the admission pressure generated by a fuel pump, which prevents disruptive pressure fluctuations when the fuel is drawn from this pressure accumulator.
• the memory is designed as a common component in the form of a pre-pressure railchamber for several high-pressure modules connected to it. Defined opening of the controlled shut-off valves in each high-pressure module causes an acceleration of the fuel in the associated flywheel, which is returned to the return railchamber. The fuel is withdrawn from the fuel pump (s) primarily from the respective return railchamber using the available residual pressure, only the amount of fuel withdrawn from the system via the injection nozzles being taken from the fuel tank.
• the predominant part of the kinetic energy of the fuel in the flow is converted into pressure energy.
• the pressure increase brought about reaches a multiple of the static admission pressure in the admission pressure railchamber and propagates in the form of a pressure wave in the direction of the individual or more injection nozzles connected to the flywheel line of the respective high pressure module, where it can be used for fuel injection.
• the pressure wave generated is reduced to the level of the pre-pressure generated in order to avoid undesired reflections and impair the function of the injection system.
• Fig. 1 the schematic representation of a Krafstoffeinspritzsy stems for a four-cylinder Krafrmaschine.
• the pre-pressure to be provided depending on the demand map of the machine in question is realized via a fuel pump 3, a pre-filter 2 being installed in the fuel tank 1 to protect it from contamination.
• This pre-pressure reaches a pre-pressure railchamber 4 which is common to all cylinders of the working machine and which is equipped with an integrated additional fuel fine filter.
• the pre-pressure railchamber 4 feeds the high-pressure modules for the individual working cylinders, which consist of a flywheel 11, a shut-off valve 10, a vibration damper 9, a receptacle for the flywheel 12 and an injection nozzle 13.
• the pre-pressure Railchamber 4 not only functions as a fuel distribution system, but also, thanks to its dimensions, acts as a pressure accumulator to reduce pressure fluctuations.
• the shut-off valves 10 in the high-pressure modules are open, the fuel under pressure is accelerated in the flywheel 11 and returned to the fuel pump 3 via a return railchamber 6 common to all working cylinders.
• the kinetic energy of the fuel in the flow is mainly converted into pressure energy by suddenly closing the electromagnetically operated shut-off valve 10, which continues in the form of a pressure wave to the injection nozzle 13 and the vibration damper 9 to the end of the flywheel 11.
• the vibration damper 9 dampens the pressure of the pressure wave to avoid undesired reflections at least to the level of the admission pressure.
• the pressure level to be recorded in the pressure wave is on average or, depending on the injection quantity, approximately 10 times the set pre-pressure and is used for metering fuel into the respective working cylinder via the injection nozzle 13 connected to the flywheel 11.
• a short-circuit line is arranged between the upstream railchamber 4 and the return railchamber 6 and is equipped with a pressure-limiting valve 5 for keeping the upstream pressure constant with little vibration.
• the fuel pressure available in the return railchamber 6 is fed directly to the fuel pump 3 to the admission pressure system.
• An insulating sleeve 7 is arranged around the high-pressure module for noise insulation and for heat protection, through which cooling liquid flows through a cooling inlet 8a and a cooling medium outlet 8b.

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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)
• Branch Pipes, Bends, And The Like (AREA)

Applications Claiming Priority (5)

Publications (2)

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• 1998
  • 1998-03-09 EP EP98923988A patent/EP0898678B1/fr not_active Expired - Lifetime
  • 1998-03-09 DE DE59806913T patent/DE59806913D1/de not_active Expired - Lifetime
  • 1998-03-09 US US09/180,649 patent/US6189508B1/en not_active Expired - Fee Related
  • 1998-03-09 JP JP10539087A patent/JP2000516684A/ja active Pending
  • 1998-03-09 WO PCT/DE1998/000716 patent/WO1998040658A2/fr active IP Right Grant
  • 1998-03-09 AT AT98923988T patent/ATE231227T1/de not_active IP Right Cessation

Non-Patent Citations (1)

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