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
  • F02M61/04—Fuel-injectors not provided for in groups F02M39/00 - F02M57/00 or F02M67/00 having valves, e.g. having a plurality of valves in series
  • F02M61/10—Other injectors with elongated valve bodies, i.e. of needle-valve type
  • F02M61/12—Other injectors with elongated valve bodies, i.e. of needle-valve type characterised by the provision of guiding or centring means for valve bodies
• • 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.
• a fuel injection system for a mixture-compressing, spark-ignited internal combustion engine which comprises a fuel injection valve, which injects fuel into a combustion chamber formed by a piston / cylinder construction, and is provided with a spark plug projecting into the combustion chamber.
• the fuel injector is provided with at least one row of injection holes distributed over the circumference of the fuel injector. Through a targeted injection of fuel through the injection holes, a jet-guided combustion process is implemented by forming a mixture cloud with at least one jet.
• a disadvantage of the fuel injector known from the abovementioned publication is, in particular, the coking of the spray orifices, which thereby block and inadmissibly reduce the flow through the fuel injector. This leads to malfunctions of the internal combustion engine.
• the fuel injector according to the invention with the characterizing features of the main claim has the advantage that a conically tapering in the outflow direction of the fuel guide area in the valve seat body when the fuel injector is closed enables hydraulic self-centering of the valve closing body on the sealing seat, thereby avoiding splashes and thus deposits in the area of the spray openings and an impermissible flow reduction can be prevented.
• spherical valve closing bodies can be used, which are simple and inexpensive to manufacture and assemble.
• valve closing body and the valve seat body in the open and closed state of the fuel injector are of different sizes, which forms a slight back pressure which leads to self-centering of the valve closing body.
• sealing seat and the guide area are drilled and ground in one operation with the same axis of symmetry in a common setting.
• Fig. 1 shows a schematic section through an embodiment of a fuel injector designed according to the invention
• FIG. 2 shows a schematic section through the exemplary embodiment of the fuel injection valve according to the invention in area II in FIG. 1.
• FIG. 1 of a fuel injector 1 is in the form of a fuel injector 1 for fuel injection systems of mixture-compressing, spark-ignited internal combustion engines.
• the fuel injection valve 1 is particularly suitable for injecting fuel directly into a combustion chamber (not shown) of an internal combustion engine.
• the fuel injection valve 1 consists of a nozzle body 2, in which a valve needle 3 is arranged.
• the valve needle 3 is operatively connected to a valve closing body 4, which cooperates with a valve seat surface 6 arranged on a valve seat body 5 to form a sealing seat.
• the fuel injection valve 1 is an inward opening one Fuel fine injection valve 1, which has at least one, in the exemplary embodiment two spray orifices 7.
• the valve closing body 4 is cardanically guided in the valve seat body 5. According to the invention, a guide region 37 of the valve seat body 5 is conically tapered in the spray direction. Grindings 38 on the valve closing body 4 ensure the supply of the fuel flowing through the fuel injection valve 1 to the sealing seat and to the spray openings 7. A detailed description of the measures according to the invention can be found in FIG. 2 and in the description.
• the nozzle body 2 is sealed by a seal 8 against an outer pole 9 of a solenoid 10.
• Solenoid 10 is present.
• the inner pole 13 and the outer pole 9 are separated from one another by a constriction 26 and from one another by a non-ferromagnetic one
• the solenoid 10 is connected via a line 19 from an electrical
• Plug contact 17 energized electrical current.
• Plug contact 17 is surrounded by a plastic sheath 18, which can be molded onto the inner pole 13.
• valve needle 3 is guided in a valve needle guide 14, which is disc-shaped.
• a paired adjusting disk 15 is used for stroke adjustment.
• the armature 20 is located on the other side of the adjusting disk 15. This armature is non-positively connected via a first flange 21 to the valve needle 3, which is connected to the first flange 21 by a weld seam 22.
• a restoring spring 23 is supported on the first flange 21 and, in the present design of the fuel injector 1, is preloaded by a sleeve 24.
• fuel channels 30, 31 and 32 run.
• the fuel is supplied via a central fuel supply 16 and filtered by a filter element 25.
• the fuel injector 1 is sealed by a seal 28 against a fuel rail, not shown, and by a further seal 37, against a cylinder head, not shown.
• An annular damping element 33 which consists of an elastomer material, is arranged on the spray-side side of the armature 20. It rests on a second flange 34, which is non-positively connected to the valve needle 3 via a weld seam 35.
• the armature 20 In the idle state of the fuel injector 1, the armature 20 is acted upon by the return spring 23 against its stroke direction so that the valve closing body 4 is held on the valve seat surface 6 in sealing contact.
• the magnetic coil 10 When the magnetic coil 10 is excited, it builds up a magnetic field which moves the armature 20 against the spring force of the return spring 23 in the stroke direction, the stroke being predetermined by a working gap 27 which is in the rest position between the inner pole 12 and the armature 20.
• the armature 20 also takes the first flange 21, which is welded to the valve needle 3, in the lifting direction.
• the valve closing body 4 in connection with the valve needle 3 lifts off from the valve seat surface 6, and the fuel passed through the fuel channels 30 to 32 is sprayed through the spray opening 7.
• FIG. 2 shows a section of the section of the fuel injector 1 designed according to the invention, designated II in FIG. 1.
• valve closing body 4 is cardanically guided in the valve seat body 5.
• the valve needle 3 does not immediately completely close the fuel injector 1 after its impact in the sealing seat.
• a certain amount of fuel is undesirably injected. Since this happens during the combustion phase of the fuel-air mixture in the combustion chamber, the flame front strikes up to the spray openings 7.
• deposits of combustion products increasingly arise in the area of the spray openings 7, which lead to the spray openings 7 being added and thus the flow rate through the fuel injector 1 being reduced to an unacceptably high level.
• the guide play between the valve closing body 4 and the valve seat body 5 is different in size depending on the stroke of the valve needle 3.
• the guide play is the smallest and is in the order of magnitude of approximately 4 ⁇ m.
• the guide play is significantly larger and is, for example, 8 ⁇ m.
• the opening angle of the conical guide region 37 is preferably between 4 ° and 15 °.
• valve closing body 4 displaces fuel which is present in the guide region 37 during its axial movement in the flow direction.
• the fuel builds up because the guide region 37 narrows in the direction of flow.
• a pressure cushion is accordingly built up in the guide area 37, which hydraulically centers the valve closing body 4 within the guide area 37.
• the valve closing body 4 thus seals immediately after the closing process over its entire sealing circumference on the valve seat surface 6 against the sealing seat. Without this measure, the valve closing body 4 would impact eccentrically on the valve seat surface 6 and only be centered after a certain time by the closing force acting on it, which is exerted by the return spring 23 via the valve needle 3.
• valve seat surface 6 and the guide area 37 must preferably be drilled and ground together in one setting on a machine tool with a common axis of symmetry.
• the invention is not restricted to the exemplary embodiments shown and can be used for any other construction of fuel injection valves 1.

Landscapes

• 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=32403702

Family Applications (1)

Country Status (5)

Families Citing this family (10)

Citations (1)

Family Cites Families (10)

• 2002
  • 2002-12-04 DE DE10256667A patent/DE10256667A1/de not_active Withdrawn
• 2003
  • 2003-07-02 WO PCT/DE2003/002210 patent/WO2004051076A1/de not_active Application Discontinuation
  • 2003-07-02 EP EP03812119A patent/EP1570174A1/de not_active Withdrawn
  • 2003-07-02 US US10/537,843 patent/US20060124774A1/en not_active Abandoned
  • 2003-07-02 JP JP2004555982A patent/JP2006509139A/ja active Pending

Patent Citations (1)

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