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
  • F02M63/0012—Valves
  • F02M63/0014—Valves characterised by the valve actuating means
  • F02M63/0015—Valves characterised by the valve actuating means electrical, e.g. using solenoid
  • F02M63/0026—Valves characterised by the valve actuating means electrical, e.g. using solenoid using piezoelectric or magnetostrictive actuators
• • 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
  • F02M45/02—Fuel-injection apparatus characterised by having a cyclic delivery of specific time/pressure or time/quantity relationship with each cyclic delivery being separated into two or more parts
  • F02M45/04—Fuel-injection apparatus characterised by having a cyclic delivery of specific time/pressure or time/quantity relationship with each cyclic delivery being separated into two or more parts with a small initial part, e.g. initial part for partial load and initial and main part for full load
  • F02M45/06—Pumps peculiar thereto
• • 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
  • F02M57/00—Fuel-injectors combined or associated with other devices
  • F02M57/02—Injectors structurally combined with fuel-injection 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
  • 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
  • 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
  • F02M63/0012—Valves
  • F02M63/0059—Arrangements of valve actuators
  • F02M63/0061—Single actuator acting on two or more valve bodies

Definitions

• the invention relates to a device for injecting fuel with a variable injection pressure curve, such as, for example, in high-pressure injection systems that can be used to supply fuel to internal combustion engines.
• EP 0 823 549 A2 relates to an injector arrangement for injecting fuel.
• An anchor element actuates both a drain valve and a control needle valve, which regulates the pressure in a control chamber.
• a force that supports the force of a compression spring is exerted on the control part.
• the drain valve and the control needle valve are controlled by an electromagnetic control via a common component.
• the control needle valve and the upper side of the control needle valve are parts of a control chamber and are dimensioned such that the control needle valve is essentially pressure-balanced at all times.
• control section elements ie control section and needle valve on the injection valve
• the needle valve is partially actuated by the mechanical coupling.
• a second higher Current level the needle valve is fully actuated.
• Another variant known from the prior art for controlling the injection pressure curve consists in pressure control via the control valve stroke.
• the advantageous separate design of the control valves allows them to be set with less effort so that the course of the injection pressure can be shaped in accordance with predetermined values by actuating the control valves of the injector.
• the parameters relevant for the injection for the pre-injection, the pressure build-up phase with boot phase, a pressure limitation and the cut-off rate can be preset depending on the application. Since the boat pressure can be determined during the pressure build-up phase independently of the nozzle design, the pump piston diameter in the injector, and the cam shaft design, the injector pump arrangement can be used for various engine designs, since the parameters relevant to the respective injection process can be used on one injector depending on the application for the respective internal combustion engine can be preset according to specific parameters.
• control valves next to each other and the high-pressure line running between them permits an enormously space-saving design of the injector.
• Pre-injection pressures and cut-off rates can be controlled thanks to the actuator control of the control valves can be varied independently of the speed and load torque on the internal combustion engine, as a result of which the desired injection pressure curve can be shaped over a wide range.
• the manufacturing tolerances of the actuator piston accommodated in the injector housing can be increased, so that cheaper production of this component can be achieved.
• control valves can be retracted in their respective seats against the springs acting on them with different forces. This enables a seal to be achieved, so that the pressure build-up phase (boot injection) can be carried out largely without loss, since the pressure build-up prevents leakage losses due to the sealing effect on the control valve seats.
• the first control valve is moved into its end position in order to implement the pilot injection - individually adapted to the respective engine design.
• the main injection is controlled by closing the second control valve, which can also be used to limit the pressure in such a way that it is moved into a partially open position. Part of the fuel can flow into a reservoir, so that the pump element in the injector can be protected against excessive loads. This also enables higher cam speeds to be achieved and thus an increase in pressure at lower speeds and lower load torques.
• FIG. 1 shows a schematic configuration of an injector with two integrated control valves
• FIG. 2 shows the components of the control valves shown on an enlarged scale, which are connected via a coupling space to the pressure space in the injector housing of the injector,
• Figure 3 is a schematic representation of the spatial arrangement of
• FIG. 4 shows the sequence of the actuation of the actuator and control valves and the resulting course of the injection pressure
• FIG 5 shows an injector with control valves accommodated in its housing.
• FIG. 1 shows a schematic representation of an injector configuration with two control valves which are integrated into the injector housing and can be actuated via a single actuator.
• An injector 1 shown here only schematically comprises an injector housing 2, in the end of which the internal combustion engine is directed a nozzle 3 is received.
• the nozzle 3 is closed by means of a nozzle needle 4, which extends from a control chamber 6.
• the nozzle needle 4 is at one end facing away from the nozzle 3 Force accumulator 7 acted upon.
• the energy accumulator 7 - for example designed as a helical spring - is enclosed by the housing 2 of the injector 1.
• the injection pressure is controlled by two control valves 8 and 10 integrated in the high-pressure supply line.
• the first control part 8 is connected to the second low-pressure area 17 on the low-pressure side, while the second control valve is connected to a first low-pressure area 16 via a constant pressure valve 14 - or alternatively a throttle element communicates.
• the opening pressure in the low-pressure region 16 of the second control valve 10 can be set by means of a spring element 15 or an adjusting element of any other design, so that the pressure load on a pressure chamber 13 by the actuator piston 12 can be adjusted. Fuel can then flow out via the partially open second control valve 10, so that the load limit of the mechanical components which are let into the interior of the injector housing 2 is not exceeded.
• the two spring elements 31 and 32 respectively assigned to the control valves 8, 10 allow the presetting of the actuation pressures on both control valves 8 and 10 respectively.
• the actuation pressures on the two control valves 8, 10 are preferably chosen to be relatively low, so that the control valves 8 and 10 respectively 10 are almost powerless. The following applies:
• the two control valves 8 and 10 are in the open state; i.e. the fuel can flow out in the direction of the arrows in each case into the second low pressure region 17 or via the constant pressure valve 14, when the pressure set there is exceeded in the first low pressure region 16.
• the two control valves 8 and 10, respectively, are actuated by the actuator element 11 - preferably designed as a piezo actuator - against the effect of the If the compression springs 31 and 32 are moved to the lower position, the control chamber 6 which acts on the nozzle needle 4 is connected via the high-pressure line 5 to the fuel supply in the pressure chamber 13 which is under maximum pressure.
• FIG. 2 shows an enlarged representation of the components in the injector which are connected to one another via a coupling space 9 provided in the injector housing.
• the control valves 8 and 10 each contain a control part, which is preferably cylindrical.
• the cross-section of the control part of the first control valve 8, the area Ai is larger than the cross-sectional area A of the control part on the second control valve 10.
• Both control parts of the two control valves 8 and 10 protrude into the coupling space 9, which is connected to the actuator 11 is pressurized.
• the first control valve 8 is connected to a low pressure region 17, in which fuel can flow out of the first control valve 8. Excess fuel flows out of the second control valve 10 into the first low pressure region 16.
• the two control valves 8, 10 each contain force accumulators 31, 33 designed with different spring constants, with which spring forces F ls F which are adapted to the respective valve function are generated.
• the coupling space 9, the line and the coupling channel 9.1 are connected to one another via the control valves 8, 10, form a channel system, the pressure relief of which is possible via a partial opening, for example of the second control valve 10.
• the constant pressure valve 14 can be connected upstream of the control valve 10, with it the pressure of the boot phase is set.
• the maximum permissible loading pressure for the mechanical components in the injector housing 2 can then be set on the constant pressure valve 14, which is provided in the outflow region in a reservoir, for example opening into the fuel tank.
• the essentially vertically extending high-pressure bore 18 is received, which directs the fuel under extremely high pressure to the nozzle 3, which projects from the injector housing 2 into the combustion chamber of an internal combustion engine.
• the spatial arrangement of the two control valves 8 and 10 and the course of the high pressure bore 18 can be seen from the illustration in FIG. 3.
• Coupling space 9 (see FIG. 2) is formed over actuator piston 11 shown in this schematic plan view, from which branch line 9.1 which pressurizes coupling space 9 branches off and which itself is to be regarded as part of coupling space 9. Shown projecting into the coupling channel 9.1, the two piston surfaces of the control valves 8, 10 are inserted, which act on the fuel under high pressure via the pressure chamber 13 acted upon by the piezo actuator 11.
• the high-pressure bore 18 extends between the two control valves 8, 10 and permits an extremely compact design of the injector housing 2 of the injector 1.
• the control chambers surrounding the control valves 8 and 10 are shown in broken lines, as is the outflow line from the second control valve 10 whose piston has a smaller piston area A than the piston of the first control valve 8 leading to the first low-pressure region 16.
• FIG. 4 shows the sequence of the actuation by the actuator, the respective stroke movements of the control valves, plotted over time, and the resulting injection pressure curve, plotted over time.
• FIG. 4 five diagrams are plotted one above the other, which show the respective stroke movements, pressures and the injection pressure curve generated, plotted over the time axis.
• the time axis can be subdivided into a pre-injection phase 25, a pressure build-up phase 26 and a pressure reduction phase 30.
• the pressure curve 21 given in the diagram below is set in the coupling space 9, 9.1, likewise subdividable into a first pressure increase corresponding to the pre-injection and a subsequent pressure increase which corresponds to the main injection.
• the stroke paths of the two control valves 8, 10 are shown in the two diagrams below, each designated by the reference numerals 22 and 23. It can be seen from diagram 22 that both the pilot injection 25 is controlled via the first control valve 8 and part of the main injection takes place.
• the main injection requires a greater time voltage to inject the required amount of fuel into the combustion chamber of the internal combustion engine.
• the nozzle needle stroke in the bottom diagram 24 (upper curve) remains constant during the main injection, so that the fuel volume required for combustion can only be transported into the combustion chamber over a longer period of time, i.e. is to be injected.
• the stroke of the control part of the second control valve 10 is plotted over the time axis.
• the second control valve 10 remains fully open during the pre-injection phase 25.
• the second control valve 10 closes only towards the end of the main injection and thus contributes to an increase in the injection pressure, see diagram 24, towards the end of the main injection.
• the course of the injection pressure according to diagram 24 can be derived from a comparison of the two diagrams 22 and 23 representing the stroke paths of the control valves 8 and 10, provided the nozzle needle stroke 4 is constant, runs as shown and consists of an opening movement at the beginning of the Pre-injection 25 and the opening of the nozzle needle 4 during the main injection over the period of time shown in diagram 24.
• the control of the control valves 8, 10 via the actuator 1 1 enables the start and end of the pre-injection and the main injection to be determined individually, depending on the design of the internal combustion engine.
• the pressure build-up phase (boot phase) can be individually preset depending on the application.
• the injection pressure curve can be significantly increased by specifically actuating the second control valve 10 towards the end of the main injection.
• FIG. 5 shows a compact injector, in whose injector housing a constant pressure valve is integrated, which is assigned to a control valve.
• the injector 1 according to FIG. 5 comprises an injector housing 2, in the upper part of which the piston 12 is inserted, which projects into a pump chamber 13. From the pump chamber 13 in the injector housing 2, the high-pressure line 5 extends to the control chamber 6 of a nozzle 3, which can be closed and released by means of the nozzle needle 4. The nozzle needle 4 in turn is acted upon by a compression spring 7, which is enclosed by the injector housing 2.
• control valves 8, 10, of which only one is shown here, are assigned a constant pressure valve 14, which is connected to the first low pressure region 16 via the bore 27 in the injector housing 2, and returns excess fuel blown off to limit the pressure back into a storage tank ,
• a bore 27 is provided on the opposite side of the injector housing 2, through which excess fuel can be fed to a second low-pressure region 17, 16.
• the injector housing 2 of the injector 1 is constructed, for example, in several stages, centering elements 28 and 29 ensuring that a leakage-reducing arrangement of the components forming the injector housing 2 in the region of the nozzle needles 4 is ensured.

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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)

Applications Claiming Priority (3)

Publications (1)

Family

ID=7636061

Family Applications (1)

Country Status (8)

Families Citing this family (7)

Family Cites Families (7)

• 2000
  • 2000-03-23 DE DE10014450A patent/DE10014450A1/de not_active Ceased
• 2001
  • 2001-03-20 HU HU0301767A patent/HUP0301767A2/hu unknown
  • 2001-03-20 JP JP2001569137A patent/JP2003528253A/ja active Pending
  • 2001-03-20 WO PCT/DE2001/001060 patent/WO2001071178A2/de not_active Application Discontinuation
  • 2001-03-20 US US09/979,502 patent/US20020145055A1/en not_active Abandoned
  • 2001-03-20 EP EP01921219A patent/EP1368564A2/de not_active Withdrawn
  • 2001-03-20 CN CNA01800640XA patent/CN1535357A/zh active Pending
  • 2001-03-20 BR BR0105313-2A patent/BR0105313A/pt not_active Application Discontinuation

Non-Patent Citations (1)

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