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
• • 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
  • F02M61/166—Selection of particular materials
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02D—CONTROLLING COMBUSTION ENGINES
  • F02D41/00—Electrical control of supply of combustible mixture or its constituents
  • F02D41/02—Circuit arrangements for generating control signals
  • F02D41/14—Introducing closed-loop corrections
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02D—CONTROLLING COMBUSTION ENGINES
  • F02D41/00—Electrical control of supply of combustible mixture or its constituents
  • F02D41/02—Circuit arrangements for generating control signals
  • F02D41/14—Introducing closed-loop corrections
  • F02D41/1438—Introducing closed-loop corrections using means for determining characteristics of the combustion gases; Sensors therefor
  • F02D41/1493—Details
  • F02D41/1496—Measurement of the conductivity of a sensor
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02D—CONTROLLING COMBUSTION ENGINES
  • F02D41/00—Electrical control of supply of combustible mixture or its constituents
  • F02D41/30—Controlling fuel injection
• • 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
  • F02M51/00—Fuel-injection apparatus characterised by being operated electrically
  • F02M51/06—Injectors peculiar thereto with means directly operating the valve needle
• • 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
  • F02M57/005—Fuel-injectors combined or associated with other devices the devices being sensors
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02D—CONTROLLING COMBUSTION ENGINES
  • F02D2200/00—Input parameters for engine control
  • F02D2200/02—Input parameters for engine control the parameters being related to the engine
  • F02D2200/06—Fuel or fuel supply system parameters
  • F02D2200/063—Lift of the valve needle
• • 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
  • F02M21/00—Apparatus for supplying engines with non-liquid fuels, e.g. gaseous fuels stored in liquid form
  • F02M21/02—Apparatus for supplying engines with non-liquid fuels, e.g. gaseous fuels stored in liquid form for gaseous fuels
  • F02M21/0218—Details on the gaseous fuel supply system, e.g. tanks, valves, pipes, pumps, rails, injectors or mixers
  • F02M21/0248—Injectors
• • 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
  • F02M2200/00—Details of fuel-injection apparatus, not otherwise provided for
  • F02M2200/02—Fuel-injection apparatus having means for reducing wear
• • 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
  • F02M2200/00—Details of fuel-injection apparatus, not otherwise provided for
  • F02M2200/24—Fuel-injection apparatus with sensors
  • F02M2200/245—Position sensors, e.g. Hall sensors
• • 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
  • F02M2200/00—Details of fuel-injection apparatus, not otherwise provided for
  • F02M2200/90—Selection of particular materials
  • F02M2200/9038—Coatings

Definitions

• the present invention relates to a coated face of a needle valve member of a diesel fuel injector adapted to be controlled with a close loop strategy.
• a close loop strategy is implemented wherein a command unit receives signal relevant of the position of the needle valve member of the fuel injectors.
• Several design of electric switch have been designed a most efficient one utilise the tip end of the needle and the complementary seating face to establish an electrical contact. Unfortunately, said faces wear under pressure and a protective coating having mechanical durability and electrical conductivity is required.
• the needle has a cylindrical core with a tip end extending along a longitudinal axis, said tip end defining a sloped sealing face adapted to contact, in a closed position, a complementary seat face of a nozzle body and therefore to close an electric circuit enabling an electrical signal relevant of said closed position to be delivered.
• said sloped sealing face is coated in a first zone with an electrically isolating wear resistant material adapted to last for the life time of the injector and, remaining electrically conductive in a distinct second zone.
• the closed position of the needle generates in said sloped sealing face contact pressures having an uneven spectrum, said pressures being maximum in said first zone.
• said conductive second zone is adjacent to said first zone.
• a pick contact pressure registers in a pick section of said first zone, the second zone starting approximately 0.2 mm away from said pick section.
• said second zone is uncoated.
• said second zone is coated with an electrically conductive coating.
• said second zone is arranged between said first zone and a third zone also coated with said wear resistant coating.
• the first zone is the upper portion of the sloped face joining the core of the needle and, the third zone extends toward the pointy extremity of the tip face.
• said second zone longitudinally extends on a width of about 0.5 mm.
• said wear resistant coating is a diamond like coating DLC.
• said wear resistant coating is about 3 ⁇ to 4 ⁇ thick.
• the invention further extends to a diesel fuel injector adapted to be controlled with a close loop control strategy, said injector comprising a nozzle assembly having a body defining a valve seat face and a needle valve member guided in a bore of the body and adapted to move between an open position and a closed position, said needle being as previously described.
• Figure 1 represents the tip end of an injector wherein a needle tip contacts a seat face of a body, said injector tip end being designed in relation with a plot of the contact pressure along the needle tip face.
• a needle valve member 12 guided in a bore 14 of a nozzle body 16 between a closed position CP and an open position OP is indirectly controlled by a small electrovalve commanding a strong hydraulic drive.
• a close loop strategy is implemented wherein an ECU computes a command signal sent to said electrovalve as a function of an input signal representative of the position of the needle 12.
• the needle 12 extends along a longitudinal axis X in an elongated cylindrical core 18 provided at an extremity with a tip end 20 defining a sloped face 22 that, in said closed position CP is in sealing contact against a complementary seating face 24 arranged at the blind end of the bore 14 preventing downstream fuel flow toward spray holes 26 arranged through the wall 28 of said body and that, in said open position OP is lifted away from said seating face 24 enabling said downstream flow and fuel spray.
• the example depicted shows a conical seating face 24 and a sloped face 22 comprising several frustoconical portions extending from an upper edge 30 intersection with the needle core 18 to a pointy extremity 32 that is in a small sac 34 defined at the very end of the bore 14, the spray holes 26 opening in said sac 34.
• the sloped face 22 is coated with a diamond like coating (DLC) that is mechanically hard and resistant, and electrically isolating.
• DLC coating layer is of 3 to 4 ⁇ thickness and is arranged to last for the life of the injector which is to be understood as adapted to last for the life time of the engine the injector equips that, for a vehicle means several hundreds of thousands of kilometers representing for the injector 10 more than 500 million fuel injections or displacements between the open position OP and the closed position CP.
• the close loop strategy requires to switch an electric contact that alternatively opens and closes an electric circuit and, to establish said electrical contact the sloped face 22 is provided with an electric conductive zone 42 that is arranged in said lower portion 40, below the pick section 36.
• the conductive zone 42 is free from DLC and in closed position CP it is in surface contact with an area of the seating face 24.
• the sloped face 22 therefore defines a first zone 44, DLC coated, then a second zone which is said conductive zone 42 then below a third zone 46, also DLC coated.
• the relevant area of the sloped face can be protected when DLC is applied and then remain bear or, alternatively, it can be coated with a specific electrically conductive coating for instance WC-CH (tungsten carbide) or taC (tetragonal amorphous Carbon).
• WC-CH tungsten carbide
• taC tetragonal amorphous Carbon
• the conductive zone 42 extends over a width W of approximately half a millimeter downwardly extending toward the pointy extremity 32 from an upper limit 48 close to the pick section 36, that is DLC coated, to a lower limit 50.
• the distance D from said pick section 36 to said upper limit 48 of the conductive zone 42 is of few tenth of a millimeter, 0.2mm for instance.
• the conductive zone 42 is continuous extending all around the needle.
• said conductive zone can be interrupted and comprise one or more sections enabling said electric contact.

Landscapes

• Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Combustion & Propulsion (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Analytical Chemistry (AREA)
• Fuel-Injection Apparatus (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=58744490

Family Applications (1)

Country Status (4)

Family Cites Families (11)

• 2017
  • 2017-04-18 GB GB1706145.8A patent/GB2561574B/en active Active
• 2018
  • 2018-04-11 EP EP18717356.2A patent/EP3612728A1/de not_active Withdrawn
  • 2018-04-11 WO PCT/EP2018/059341 patent/WO2018192828A1/en unknown
  • 2018-04-11 CN CN201880025321.3A patent/CN110719996A/zh active Pending

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