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
  • F02M61/00—Fuel-injectors not provided for in groups F02M39/00 - F02M57/00 or F02M67/00
  • F02M61/16—Details not provided for in, or of interest apart from, the apparatus of groups F02M61/02 - F02M61/14
  • F02M61/18—Injection nozzles, e.g. having valve seats; Details of valve member seated ends, not otherwise provided for
  • F02M61/188—Spherical or partly spherical shaped valve member ends
• • 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
  • F02M61/00—Fuel-injectors not provided for in groups F02M39/00 - F02M57/00 or F02M67/00
  • F02M61/16—Details not provided for in, or of interest apart from, the apparatus of groups F02M61/02 - F02M61/14
  • F02M61/18—Injection nozzles, e.g. having valve seats; Details of valve member seated ends, not otherwise provided for

Definitions

• the invention relates to a fuel injector according to the preamble of the main claim.
• the direct injection of fuel into the combustion chamber of an internal combustion engine generally occurs, in particular in the case of direct petrol injection or the injection of diesel.
• the fuel injector according to the invention with the characterizing features of the main claim has the Advantage that these aforementioned negative effects of coking (soot deposition) are restricted or eliminated, particularly at the valve tip protruding into the combustion chamber, with its outlet openings.
• coking deposits in the outlet openings can be largely prevented. Due to the buoyancy of the gas phase compared to the liquid phase, the gas remains in the device for storing combustion chamber gas.
• the spray parameters and the valve function can be stably maintained over their long service life even when fuel is directly injected into a combustion chamber on the fuel injectors.
• FIG. 1 shows a partially illustrated fuel injector and FIG. 2 shows a schematic section through an outlet opening with a liquid column standing therein and tearing off.
• FIG. 1 a valve in the form of an injection valve for fuel injection systems of mixed-compression spark-ignition internal combustion engines is partially shown as an exemplary embodiment.
• the injection valve has a tubular valve seat support 1, in which a longitudinal opening 3 is formed concentrically with a valve longitudinal axis 2.
• a longitudinal opening 3 is formed concentrically with a valve longitudinal axis 2.
• a longitudinal opening 3 is formed concentrically with a valve longitudinal axis 2.
• the injection valve is actuated in a known manner, for example electromagnetically.
• a schematically indicated electromagnetic circuit with a solenoid 10, an armature 11 and a core 12 is used for the axial movement of the valve needle 5 and thus for opening against the spring force of a return spring (not shown) or closing the injection valve.
• the armature 11 is connected to the valve closing body 7 opposite end of the valve needle 5 by z.
• B. a weld seam formed by means of a laser is connected and aligned with the core 12.
• a guide opening 15 of a valve seat body 16 is used to guide the valve closing body 7 during the axial movement Core 12 facing away from the end of the valve seat support 1 in the concentric to the longitudinal axis 2 of the longitudinal opening 3 is sealed by welding.
• the valve seat body 16 is, for example, cup-shaped, with a jacket part 17 of the valve seat body 16 merging in the direction of the armature 11 into a collar 18 resting on the valve seat carrier 1.
• the valve seat body 16 On the side opposite the collar 18, the valve seat body 16 has a base part 19 which is, for example, convexly curved.
• the insertion depth of the valve seat body 16 determines the size of the stroke of the valve needle 5, since the one end position of the valve needle 5 when the magnet coil 10 is not energized due to the valve closing body 7 resting on a valve seat surface 22 which is conically tapered or slightly curved at the bottom part 19 of the valve seat body 16 is set.
• the other end position of the valve needle 5 is determined when the solenoid 10 is excited, for example by the armature 11 resting on the core 12. The path between these two end positions of the valve needle 5 thus represents the stroke.
• the spherical valve closing body 7 interacts with the frustoconical or curved valve seat surface 22 of the valve seat body 16, which lies between the guide opening 15 and several in a central region of the base part 19 of the valve seat body 16 introduced outlet openings 23 is formed.
• the bottom part 19 forms the spray region of the fuel injector.
• the fuel injection valve is designed in particular as a so-called multi-hole valve, which is particularly suitable for injecting fuel directly into a combustion chamber, not shown.
• the outlet openings 23 are aligned, for example, at different angles to the valve longitudinal axis 2, with, for example, all outlet openings 23 moving away from the valve longitudinal axis 2 in the downstream direction at an angle.
• the fuel injection valve according to the invention is to a large extent to prevent coking deposits of the combustion chamber in the area of the outlet openings 23 from clogging them and thus to change the injection quantities considerably over the life of the valve.
• valve closing body 7 and the curved bottom part 19 of the valve seat body 16 are formed with different radii, when the fuel injection valve is closed, there is a closed space within the annular valve seat surface 22 in the area of the outlet openings 23 between the valve closing body 7 and the bottom part 19, which has a dead volume 25 represents.
• gas storage in the dead volume 25 should take place in order to avoid coking deposits at the outlet openings 23.
• FIG. 2 schematically shows an outlet opening 23.
• Valve closing body 7 is pressed back to the valve seat surface 22 at the end of the injection process, the flow through the outlet openings 23 is stopped abruptly. So no more fuel flows through the
• the liquid column 27 which emerges from the outlet openings 23 immediately before the valve closes has a certain inertia due to its mass.
• the negative pressure in the liquid column 27 which arises as a result of the closing of the valve and the associated stop of the flow in the sealing seat area becomes greater, starting from an outlet plane 28 of the outlet opening 23, in the upstream direction within the outlet opening 23 due to inertia.
• the vapor pressure of the liquid falls below.
• a vapor phase suddenly forms, as a result of which the part 30 of the liquid column 27 located downstream of this point 29 tears away from the remaining liquid due to inertia.
• a meniscus of the liquid is formed within the outlet opening 23, at which there is a phase boundary between the liquid and the gas surrounding the valve.
• all components directly on the combustion chamber are subject to extreme heat, including a direct injection valve, especially those in the combustion chamber protruding outlet openings 23.
• coking residues can form in particular at the phase boundary mentioned above, which accumulate on the wall of the outlet opening 23 and lead to the disadvantages to be overcome which have already been explained.
• annular coking deposits are formed in the outlet openings 23 at a certain depth, which disadvantageously constrict the flow.
• this device for gas storage is designed as a central blind bore 33 in the valve closing body 7 on its surface facing the dead volume 25.
• the blind bore 33 is with combustion chamber gas or with the
• the valve closing body 7 from the valve seat surface 22 increases the liquid pressure in the dead volume 25, as a result of which the gas volume in the blind bore 33 is compressed. The gas is pressed deeper into the blind bore 33. When the valve closes, the liquid pressure decreases again and the gas volume expands again within the blind bore 33. Since the inflow of further liquid into the dead volume 25 is prevented when the valve is closed, the inertia of the liquid which just emerged creates a negative pressure in the liquid phase. This can the gas volume of the blind bore 33 expand even further, so that it partially reaches the dead volume 25. The volume of liquid displaced in this way can flow out of the outlet opening 23.
• a plurality of smaller blind bores 33 can also be arranged side by side on the valve needle end facing the outlet openings 23 or on
• Valve closing body 7 may be provided. This has the advantage that the cross section of the individual blind bores 33 is smaller for the same gas storage volume and thus the capillary action in the blind bores 33 increases. The stored gas can thus be driven out of the blind holes 33 even less by flow forces of the liquid.
• valve needle tip or the valve closing body 7 are not exclusively the components of the fuel injector on which the blind bores 33 according to the invention can be formed. Rather, it is only necessary to ensure that the blind bores 33 have access to the dead volume 25 and that the gas volume cannot escape from the gas storage volume by means of buoyancy.

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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=7651335

Family Applications (1)

Country Status (9)

Families Citing this family (8)

Family Cites Families (10)

• 2000
  • 2000-08-04 DE DE10038097A patent/DE10038097A1/de not_active Withdrawn
• 2001
  • 2001-07-19 CZ CZ20021156A patent/CZ20021156A3/cs unknown
  • 2001-07-19 WO PCT/DE2001/002709 patent/WO2002012720A1/de not_active Ceased
  • 2001-07-19 RU RU2002110093/06A patent/RU2002110093A/ru unknown
  • 2001-07-19 EP EP01962569A patent/EP1307652A1/de not_active Withdrawn
  • 2001-07-19 JP JP2002517976A patent/JP2004506138A/ja active Pending
  • 2001-07-19 US US10/089,913 patent/US20030019465A1/en not_active Abandoned
  • 2001-07-19 CN CN01802299A patent/CN1386170A/zh active Pending
  • 2001-07-19 KR KR1020027004289A patent/KR20020037059A/ko not_active Withdrawn

Non-Patent Citations (1)

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