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
  • F02M61/162—Means to impart a whirling motion to fuel upstream or near discharging orifices
• • 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
• • 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
  • F02B—INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL
  • F02B3/00—Engines characterised by air compression and subsequent fuel addition
  • F02B3/06—Engines characterised by air compression and subsequent fuel addition with compression ignition

Definitions

• This invention relates to a fuel injection valve for a diesel engine.
• Conventional diesel injectors incorporate a needle valve formed by the conical tip of a needle member that co ⁇ operates with a frusto-conical valve seat to control the flow of fuel.
• Fuel is supplied to an annular chamber surrounding the needle member adjacent its tip so that a pressure impulse in the fuel supply serves to move the needle member axially and separate the needle tip from the valve seat.
• Fuel then flows directly from said annular chamber through the central orifice of the valve seat.
• the spray orifice is aligned axially with the needle member and valve seat, but in a multi-spray injector a plurality of spray orifices are formed in a nozzle with the outlet side of the valve- seat. Multi-spray injectors are preferred where it is desired to disperse the injected fuel in the combustion system.
• An object of the present invention is to provide an improved fuel injection valve, in particular a valve that will produce a spray in the form of a swirling cone of fuel.
• a fuel injection valve for a diesel engine comprises a fuel delivery nozzle body formed with a central bore, a fuel spray orifice co-axial with said bore, a frusto-conical valve seat co-axial with and tapering inwards towards said orifice, and a fuel supply passage that supplies fuel to said valve seat and orifice, and a needle member that is slidably received in said bore and has a cyl ⁇ indrical end portion of reduced diameter terminating in a conical tip that co-operates with said valve seat to open and close said orifice; characterised in that said nozzle body is formed with a chamber that communicates with said fuel supply passage and into which a shoulder portion of the needle member projects so that pressurisation of the fuel moves the needle member axially to disengage its conical end from the valve seat, and in that the nozzle body is formed with a plurality of fuel supply passages that extend tangen- tially of, and open into, a cylindrical portion of said central bore adjacent to the wider
• the opening of the spool valve occurs progressively thereby exercising control over the flow of fuel to the valve seat.
• the axial spacing of said openings of the fuel supply passages in relation to the valve seat can be varied to produce a delay in the two open ⁇ ing actions.
• Figure 1 is an axial section through an injection valve according to a first embodiment of the invention
• Figure 3 is a section in the plane 3-3 of Figure 1
• Figure 4 is an enlarged view of the end of the injector nozzle in Figure 1 with the needle member lifted off the seat
• Figure 5 is a part axial section through an injection valve according to a second embodiment of the invention.
• Figure 6 is an axial section through an injection valve according to a third embodiment of the invention.
• Figure 7 is a section in the plane 7-7 in Figure 6, and
• Figure 8 is a transverse vertical section through the cyl ⁇ inder of a diesel engine fitted with an injector incorporating an injection valve according to the invention.
• Figure 8 shows a fuel -injector 1 mounted in the head 2 of a diesel engine so as to inject a spray of fuel into a com ⁇ bustion chamber defined by the underside of the head, the cylinder 3 in the blo 4 and the crown of the piston 5.
• a bracket 6 and stud 7 clamp the injector down in a bore 8 in the head, and a fuel pipe 9 supplies fuel to the top of the injector.
• the injector comprises a body 10 to which the fuel pipe 9 is connected at its upper end, and which is adapted to supply fuel through an internal passage 11 (see Figure 1) to a nozzle assembly 12 connected to the lower end of the body by a cap nut 13.
• the injector body 10 and the means for mounting it in the head may be of known design, but the nozzle assembly 12 is specially adapted according to the invention, as shown in Figures 1 to 1 , so as to produce an injected fuel spray in the form of a cone.
• the nozzle assembly 12 comprises a nozzle body 14 and a needle member 15 that is smoothly slidably within a central cylindrical bore 16 of the body 14.
• the lower portion 17 of the needle member is of reduced diameter and terminates in a conical nose 18. This portion 17 extends through a corre ⁇ sponding bore 19 at the lower end of the body 14, and the nose 18 of the needle member co-operates with a frusto- conical seat 20 at the lower end of bore 19 surrounding a fuel injection hole 21.
• a compression spring 22 is mounted on a spigot 23 at the upper end of the needle member 15 and acts between the injector body 10 and the needle member 15 to urge the latter- downwards and engage the nose 18 with the seat 20, thereby closing the fuel injection hole 21 and forming a liquid and air-tight seal.
• the upper surface of the nozzle body 14 is formed with an annular fuel gallery 24 that communicates with the fuel passage 11 in the injector body, and four equi-anularly spaced fuel passages 25 extend downwards from the gallery 24 to the lower end of the nozzle body.
• An opening 26 is formed between one of these passages 25 and the lower end 16' of the central bore 16 so that pressurisation of the fuel will be effective within the lower end of bore 16 to act upon the shoulder portion 15 ' of the needle member and lift the latter against the bias of spring 22.
• each passage 25 communicates with an in ⁇ wardly extending pasage 27 that opens into the bore 19 ad ⁇ jacent the top of the seat 20.
• These four passages 27 are directed tangentially of the bore 19 and seat 20 so as to direct fuel in a common sense of rotation about the central longitudinal axis of the injector, as shown in Figure 3.
• the lower reduced diameter portion 17 of the needle member immediately adjacent the nose 18 constitutes a land 28 which obstructs the tangential passages 27 to a varying degree during movement of the needle member 15.
• the choice of the size of the fuel passages, their number and disposition may be such as to control the pressure and volume of fuel flowing between the nose 18 and the seat 20 for a given separation between the nose and the seat, there ⁇ by enabling the choice of cone angle to be made independent ⁇ ly of these parameters.
• the passages 27 may, instead of lying in a plane perpendicul r to the needle axis, lie on a frusto-conical surface so that they are directed inwards and downwards at and angle O.
• the nozzle body 14 shown in Figures 1 to 5 is formed as a one-piece body, with the fuel passages 25, 26 and 27 being bored therein, and with the outer portions of those bore ⁇ holes for passages 26 and 27 being plugged at 30.
• the nozzle body 14 may be formed as an assembly comprising an inner cylindrical portion 31 received as a close fit within an outer sleeve portion 32, grooves being formed in the outer surface of the inner portion 31 to be closed by the inner surfaces of the sleeve portion 32 and thereby form the passages 25 and 27.

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 (2)

Publications (1)

Family

ID=10534229

Family Applications (1)

Country Status (6)

Families Citing this family (6)

Family Cites Families (7)

• 1983
  • 1983-10-27 GB GB08328715A patent/GB2131875B/en not_active Expired
  • 1983-10-28 JP JP58503508A patent/JPS59502032A/ja active Pending
  • 1983-10-28 EP EP83903396A patent/EP0137788A1/de not_active Ceased
  • 1983-10-28 WO PCT/GB1983/000275 patent/WO1984001980A1/en not_active Application Discontinuation
  • 1983-11-10 CA CA000440876A patent/CA1199242A/en not_active Expired
  • 1983-11-11 IT IT8323685A patent/IT1209489B/it active

Non-Patent Citations (1)

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