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
  • F02M47/00—Fuel-injection apparatus operated cyclically with fuel-injection valves actuated by fluid pressure
• • 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
  • F02M45/00—Fuel-injection apparatus characterised by having a cyclic delivery of specific time/pressure or time/quantity relationship
• • 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
  • F02M41/00—Fuel-injection apparatus with two or more injectors fed from a common pressure-source sequentially by means of a distributor
  • F02M41/16—Fuel-injection apparatus with two or more injectors fed from a common pressure-source sequentially by means of a distributor characterised by the distributor being fed from a constant pressure source, e.g. accumulator or constant pressure positive displacement pumps
• • 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
  • F02M45/00—Fuel-injection apparatus characterised by having a cyclic delivery of specific time/pressure or time/quantity relationship
  • F02M45/12—Fuel-injection apparatus characterised by having a cyclic delivery of specific time/pressure or time/quantity relationship providing a continuous cyclic delivery with variable pressure
• • 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
  • F02M63/0003—Fuel-injection apparatus having a cyclically-operated valve for connecting a pressure source, e.g. constant pressure pump or accumulator, to an injection valve held closed mechanically, e.g. by springs, and automatically opened by fuel pressure
• • 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
  • F02M63/0003—Fuel-injection apparatus having a cyclically-operated valve for connecting a pressure source, e.g. constant pressure pump or accumulator, to an injection valve held closed mechanically, e.g. by springs, and automatically opened by fuel pressure
  • F02M63/0007—Fuel-injection apparatus having a cyclically-operated valve for connecting a pressure source, e.g. constant pressure pump or accumulator, to an injection valve held closed mechanically, e.g. by springs, and automatically opened by fuel pressure using electrically actuated valves

Definitions

• the invention relates to a fuel injection system, in particular a common rail system, for supplying fuel to internal combustion engines, in particular diesel engines, with a plurality of cylinders.
• Air is drawn in and compressed in diesel engines. At the end of the compression stroke, high-pressure fuel is injected into the combustion chamber, where the mixture of air and fuel ignites itself.
• the preparation of the air-fuel mixture has a significant influence on the fuel consumption, the exhaust gas composition and the combustion noise of the diesel engine.
• the fuel injection system is heavily involved in the quality of the mixture preparation.
• a high pressure pump delivers, possibly with the help of a Pre-feed pump, the fuel to be injected from a tank into the central high-pressure fuel reservoir, which is referred to as a common rail.
• Fuel lines lead from the rail to the individual injectors, which are assigned to the cylinders of the internal combustion engine. The injectors are dependent on the
• Operating parameters of the internal combustion engine are individually controlled by the engine electronics in order to inject fuel into the combustion chamber of the internal combustion engine.
• injection curve denotes the curve of the fuel quantity injected into the combustion chamber as a function of the crank or cam angle.
• Injection course is the injection duration. This includes the duration of the injection in degrees of crank or cam angle or milliseconds, during which the respective injector is open and fuel flows into the combustion chamber.
• the injection process can be shaped under pressure control.
• a variable injection pressure is generated in the injectors on the injection nozzle.
• the variable injection pressure is realized by a pressure control valve, which in each
• the pressure control valve can e.g. can be operated via a magnetic actuator or a piezo actuator.
• the object of the invention is .es, a fuel injection system to provide that is simple and inexpensive to manufacture. Nevertheless, it should be possible with the fuel injection system according to the invention to shape the injection course at least as well as in conventional fuel injection systems.
• a fuel injection system for supplying fuel to internal combustion engines, in particular diesel engines, with a plurality of cylinders, in that one
• Valve arrangement for shaping the course of the injection in particular an injector for pressure modulation, is connected via a high-pressure line system in which a central distributor element is arranged to a plurality of injectors from which the injection takes place.
• the injection course in particular the pressure modulation, is shaped centrally and not separately for each cylinder.
• This provides the advantage that only one pressure control valve is required for the entire internal combustion engine.
• the actual injection is carried out by separate injectors, one of which is provided for each cylinder of the internal combustion engine. At the end of the injection process, the injector closes to shape the injection course, as a result of which no more fuel is fed into the high-pressure line system.
• a special embodiment of the invention is characterized in that the injectors from which the injection takes place are formed by conventional nozzle holder combinations.
• the basic structure of a nozzle holder combination consists of nozzle holder and Injector together.
• the injection nozzle comprises a nozzle body with a guide bore in which a nozzle needle is displaceably guided.
• both so-called single-spring holders and two-spring holders can be used.
• the conventional nozzle holder combinations have the advantage that they require little installation space and are inexpensive to manufacture.
• a further special embodiment of the invention is characterized in that a nozzle needle, the needle stroke of which is controllable, is accommodated in the valve arrangement for shaping the course of the injection. It is thereby achieved that the injector works as a variable throttle for shaping the course of the injection.
• the pressure in the high-pressure line system depends on the needle stroke of the injector for shaping the course of the injection.
• the distributor element is formed by a distributor shaft or a solenoid valve.
• the pressure provided by the injector for shaping the course of the injection is distributed by the distributor element to the injectors from which the injection takes place.
• the distributor shaft is e.g. with the camshaft
• a further particular embodiment of the invention is characterized in that a control valve is provided in the high-pressure line system between the valve arrangement for shaping the course of the injection and the distributor element.
• the control valve can be magnet or piezo controlled and is closed during the pressure build-up in the fuel injection system according to the invention.
• the control valve is only opened at the end of the injection process. When the control valve is open, the high-pressure fuel is blown out of the high-pressure line system into the leak oil. As a result, the pressure in the high-pressure line system is quickly reduced.
• Another particular embodiment of the invention is characterized in that the high-pressure line system is connected to a feed pump via the distributor element.
• the feed pump serves to pressurize the lines of the high-pressure line system that are not currently involved in the injection.
• a further particular embodiment of the invention is characterized in that the control valve is connected to the distributor element and that a buffer volume is provided between the control valve and the distributor element.
• the buffer volume must be designed in such a way that a pressure increase in the high-pressure line system between the distributor element and the injectors, from which no injection is currently taking place, is avoided via the opening pressure of the currently activated injector. It is also important to ensure that the pressure reduction in the high-pressure line system between the distributor element and the currently activated injector, from which the injection takes place, takes place quickly enough. This requires a large buffer volume.
• too large a buffer volume can lead to the pressure in the high-pressure line system between the distributor element and the injectors, from which no injection is currently taking place, being too low for refilling in the period is between two injections.
• Fig. 1 is a hydraulic circuit diagram of a
• Fig. 2 is a hydraulic circuit diagram of a
• Fuel injection system according to a second embodiment of the invention.
• an injector for shaping the injection course is designated 1.
• the injector 1 for shaping the injection course is referred to below as an EVF injector.
• the EVF injector 1 is supplied with fuel via a high-pressure connection 2 from a central high-pressure fuel reservoir (not shown).
• a high-pressure line 3 leads from the EVF injector 1 to a distributor element 4. Go from the distributor element 4 four high pressure lines 5, 6, 7 and 8. The high-pressure lines 5, 6, 7 and 8 lead to injectors 9, 10, 11 and 12. The injectors 9, 10, 11 and 12 serve to inject the high-pressure fuel into the combustion chambers (not shown) of the internal combustion engine.
• a control valve 13 is installed in the high-pressure line 3. Via the control valve 13, the pressure in the high-pressure line 3 can be quickly reduced if necessary. The fuel from the high-pressure line 3 passes back into a fuel anchor 16 via the control valve 13.
• fuel can be fed to the pump with the aid of a feed pump 15 via a high-pressure line 14
• Distribution element 4 are promoted. As a result, the high-pressure lines 5, 6, 7 and 8, which are not currently involved in the injection, can be pressurized.
• the central element of the invention is the EVF injector 1, which is used as a variable throttle.
• the pressure thus generated in the high-pressure line 3 is roughly a function of the needle stroke of the EVF injector 1.
• the control valve 13 is initially still closed.
• the modulated pressure in the high pressure line 3 is via the
• Distributor element 4 distributed on the high pressure lines 5, 6, 7 and 8.
• the distributor element 4 is connected to the camshaft of the internal combustion engine (or the
• the solenoid-operated control valve 13 is opened and the fuel flows back into the fuel tank 16.
• FIG. 2 The embodiment of the invention shown in FIG. 2 is similar to the fuel injection system shown in FIG. 1.
• the same reference numerals are used to designate the same parts.
• reference is also made to the detailed description of FIG. 1 above. In the following, reference is made only to the differences between the embodiments shown in FIGS. 1 and 2.
• FIG. 2 differs from the fuel injection system described above in that the control valve 13 via a fuel line 19, a buffer volume 18 and the
• Fuel line 14 is connected to the distributor element 4. That is, the shut-off fuel of the shut-off valve 13 does not flow back into the leak oil or the fuel tank 16, as in the fuel injection system shown in FIG. 1. In the fuel injection system shown in FIG. 2, the leak quantity is blown off into the buffer volume 18.
• the buffer volume 18 must be designed in such a way that a pressure increase in the
• High-pressure fuel lines 5, 6 and 7 are avoided via the opening pressure of the connected injectors 9, 10 and 11 and the pressure reduction in the high-pressure line 8 is fast enough. This requires a large buffer volume 18. On the other hand, too large a buffer volume 18 can lead to the pressure in the high-pressure lines 9, 10 and 11 is too low for refilling in the period between two injections.

Landscapes

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

Applications Claiming Priority (3)

Publications (1)

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ID=7928646

Family Applications (1)

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Families Citing this family (3)

Family Cites Families (9)

• 1999
  • 1999-11-11 DE DE19954206A patent/DE19954206A1/de not_active Withdrawn
• 2000
  • 2000-10-20 CZ CZ20012474A patent/CZ20012474A3/cs unknown
  • 2000-10-20 EP EP00979441A patent/EP1144840A1/de not_active Withdrawn
  • 2000-10-20 WO PCT/DE2000/003696 patent/WO2001034965A1/de not_active Application Discontinuation
  • 2000-10-20 JP JP2001536868A patent/JP2003514187A/ja active Pending
  • 2000-10-20 KR KR1020017008632A patent/KR20010101423A/ko not_active Application Discontinuation

Non-Patent Citations (1)

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