WO1999061780A9 - Injecteur pour gaz naturel comprime tolerant aux contaminants et organisation de la traversee de l'injecteur par le carburant gazeux - Google Patents

Injecteur pour gaz naturel comprime tolerant aux contaminants et organisation de la traversee de l'injecteur par le carburant gazeux

Info

Publication number
WO1999061780A9
WO1999061780A9 PCT/US1999/011605 US9911605W WO9961780A9 WO 1999061780 A9 WO1999061780 A9 WO 1999061780A9 US 9911605 W US9911605 W US 9911605W WO 9961780 A9 WO9961780 A9 WO 9961780A9
Authority
WO
WIPO (PCT)
Prior art keywords
fuel
armature
inlet connector
flow
fuel inlet
Prior art date
Application number
PCT/US1999/011605
Other languages
English (en)
Other versions
WO1999061780A1 (fr
Inventor
James Paul Fochtman
Danny Orien Wright
James H Cohen
Original Assignee
Siemens Automotive Corp Lp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Siemens Automotive Corp Lp filed Critical Siemens Automotive Corp Lp
Priority to BR9911594-8A priority Critical patent/BR9911594A/pt
Priority to KR1020007013322A priority patent/KR20010043854A/ko
Priority to EP99930119A priority patent/EP1082537B1/fr
Priority to DE69928103T priority patent/DE69928103T2/de
Priority to JP2000551143A priority patent/JP4276383B2/ja
Publication of WO1999061780A1 publication Critical patent/WO1999061780A1/fr
Publication of WO1999061780A9 publication Critical patent/WO1999061780A9/fr

Links

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
    • 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
    • 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
    • F02M21/0257—Details of the valve closing elements, e.g. valve seats, stems or arrangement of flow passages
    • F02M21/026—Lift valves, i.e. stem operated valves
    • F02M21/0263—Inwardly opening single or multi nozzle valves, e.g. needle valves
    • F02M21/0266—Hollow stem valves; Piston valves; Stems having a spherical tip
    • 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
    • F02M21/0251—Details of actuators therefor
    • F02M21/0254—Electric actuators, e.g. solenoid or piezoelectric
    • 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
    • F02M51/061—Injectors peculiar thereto with means directly operating the valve needle using electromagnetic operating means
    • F02M51/0625—Injectors peculiar thereto with means directly operating the valve needle using electromagnetic operating means characterised by arrangement of mobile armatures
    • 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
    • F02M51/061—Injectors peculiar thereto with means directly operating the valve needle using electromagnetic operating means
    • F02M51/0625—Injectors peculiar thereto with means directly operating the valve needle using electromagnetic operating means characterised by arrangement of mobile armatures
    • F02M51/0664—Injectors peculiar thereto with means directly operating the valve needle using electromagnetic operating means characterised by arrangement of mobile armatures having a cylindrically or partly cylindrically shaped armature, e.g. entering the winding; having a plate-shaped or undulated armature entering the winding
    • F02M51/0671—Injectors peculiar thereto with means directly operating the valve needle using electromagnetic operating means characterised by arrangement of mobile armatures having a cylindrically or partly cylindrically shaped armature, e.g. entering the winding; having a plate-shaped or undulated armature entering the winding the armature having an elongated valve body attached 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
    • 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
    • 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
    • F02M21/0227—Means to treat or clean gaseous fuels or fuel systems, e.g. removal of tar, cracking, reforming or enriching
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
    • Y02T10/00—Road transport of goods or passengers
    • Y02T10/10—Internal combustion engine [ICE] based vehicles
    • Y02T10/30—Use of alternative fuels, e.g. biofuels

Definitions

  • the present application relates to a compressed natural gas injector, which is tolerant of contamination in the gas.
  • CNG Compressed natural gas
  • CNG injectors gas injectors
  • the CNG injector is required to deliver a precise amount of fuel per injection pulse and maintain this accuracy over the life of the injector.
  • certain strategies are required to help reduce the effects of contaminants in the fuel.
  • Compressed natural gas is delivered throughout the country in a pipeline system and is mainly used for commercial and residential heating. While the heating systems can tolerate varying levels of quality and contaminants in the CNG. the tolerance levels in automotive gas injectors are significantly lower.
  • CNG C12H10N10
  • Oxides of many of the metal types found in the pipeline can also be introduced into the system.
  • faulty compressors can introduce vaporized compressor oils, which blow by the seals of the compressor and enter into the gas.
  • the invention relates to an electromagnetically operable fuel injector for a gaseous fuel injection system of an internal combustion engine, the injector having a generally longitudinal axis, which comprises a ferromagnetic core, a magnetic coil at least partially surrounding the ferromagnetic core, an armature magnetically coupled to the magnetic coil and being movably responsive to the magnetic coil, the armature actuating a valve closing element which interacts with a fixed valve seat of a fuel valve and being movable away from the fixed valve seat when the magnetic coil is excited.
  • the armature has a generally elongated shape and a generally central opening for axial reception and passage of gaseous fuel from a fuel inlet connector positioned adjacent thereto.
  • the fuel inlet connector and the armature being adapted to permit a first flow path of gaseous fuel between the armature and the magnetic coil and a valve body shell as part of a path leading to the fuel valve.
  • At least one first fuel flow aperture extends through a wall portion of the armature to define a second flow path of gaseous fuel as part of a path leading to the fuel valve.
  • the armature defines at least one-second aperture in a wall portion thereof to define a third flow path of gaseous fuel as part of a path leading to the fuel valve.
  • the at least one second aperture is oriented at a generally acute angle with respect to the longitudinal axis.
  • the fuel inlet connector and the armature are a spaced to define a working gap therebetween and are adapted to permit the first flow path of gaseous fuel within the working gap.
  • the fuel injector further comprises a valve body positioned downstream of the armature and having at least one aperture in a wall portion thereof for reception of fuel from at least two of the flow paths of gaseous fuel from the armature and the fuel inlet connector.
  • a valve body shell at least partially surrounds the armature and the valve body, the valve body shell defining a radial space with the armature for passage of the first flow path of gaseous fuel between the armature and the valve body shell.
  • the fuel inlet connector is positioned above the armature and is spaced from the armature by a working gap, the fuel inlet connector defining a through passage for directing fuel toward the armature and the fixed valve seat.
  • the fuel inlet connector comprises an upper end portion adapted for reception of gaseous fuel from a fuel source, and a lower end portion for discharging gaseous fuel, the lower end portion having a lower surface which faces an upper surface of the armature, the lower surface of the fuel inlet connector having a plurality of radially extending raised pads defined thereon, the pads having recessed portions therebetween to permit fuel to flow therethrough and across the working gap defined between the fuel inlet connector and the armature.
  • the armature defines at least one first and at least one second fuel flow aperture extending through wall portions thereof, the at least one first and at least one second aperture oriented at an acute angle with the longitudinal axis, and positioned for directing fuel therethrough toward the fixed valve seat.
  • the lowermost surface of the fuel inlet connector and the armature are adapted to permit gaseous fuel to flow across the working gap and between the armature and the magnetic coil whereby at least three fuel flow paths are permitted.
  • Preferably lowermost end portion of the fuel inlet connector has a generally chamfered configuration along the lowermost outer surface thereof.
  • the generally chamfered portion of the fuel inlet connector preferably has a generally arcuate cross-section.
  • the valve-closing element is a valve needle adapted for selective engagement and disengagement with the fixed valve seat and is attached to the armature by crimped portions of the armature.
  • a fuel filter is positioned at an upper end portion of the fuel inlet connector for filtering fuel prior to reception by the fuel inlet connector.
  • the fuel inlet connector includes a lower surface portion having a plurality of radially extending grooves defining a corresponding plurality of radially extending raised pads so as to reduce the effective surface area of the lower surface portion of the fuel inlet connector facing the armature to thereby permit the gaseous fuel to flow generally transversely in the working gap, the transverse fuel flow thereby preventing accumulation of contaminants in the working gap.
  • the generally radially extending pads preferably have a generally trapezoidal shape, but may be of various shapes, depending upon the circumstances or results desired. Further, the fuel injector is applicable to liquid fuel systems such as gasoline, as well as with the preferred CNG systems.
  • the valve closing element is a generally elongated valve needle having a spherically shaped end portion and configured and adapted to engage a frust-conically shaped fixed valve seat to close the valve, and movable therefrom to open the valve to permit fuel to pass therethrough toward the intake manifold of the internal combination engine.
  • the valve needle is connected to the lower end portion of the armature by crimped portions.
  • the resilient device to move the armature to close the valve is a coil spring in engagement at one end with the fuel inlet connector and at the other end with the armature to bias the armature downwardly toward the valve seat.
  • the armature includes at least two of the first apertures extending through wall portions thereof and generally transverse to the longitudinal axis for receiving fuel from the generally axial elongated central opening.
  • the armature may alternatively define a plurality of the first apertures for receiving fuel from said generally axial elongated central opening.
  • the armature may also define a plurality of the second apertures, at least certain of the second apertures extending at a generally acute angle to the longitudinal axis to receive fuel from the generally central opening.
  • a method for directing gaseous fuel through an electromagnetically operable fuel injector for a fuel system of an internal combustion engine having a generally longitudinal axis, and including a fuel inlet end portion and a fuel outlet end portion, a fuel inlet connector positioned at the fuel inlet end portion and having a fuel inlet end portion and a fuel outlet end portion, an armature positioned adjacent the fuel outlet end portion of the fuel inlet connector and having a generally central elongated opening for reception of fuel from said fuel inlet connector, the armature being spaced from the fuel inlet connector to define a working gap to permit movement of the armature toward and away from the fuel inlet connector to selectively open and close a fuel valve to permit gaseous fuel to pass therethrough to an air intake manifold.
  • the method comprises, directing the gaseous fuel to pass axially through the fuel inlet connector, directing the gaseous fuel to pass from the fuel inlet connector to the generally elongated central opening of the armature in an axial direction toward the fuel valve, directing at least a portion of the fuel flow from the fuel inlet connector to the armature to flow generally transversely across the working gap. and diverting at least a portion of the flow of gaseous fuel passing through the armature to flow in a direction away from the axial direction.
  • the step of directing the gaseous fuel passing through the armature to flow in a direction away from the axial direction is preferably accomplished by directing the gaseous fuel through at least one first aperture provided in a wall portion of the armature.
  • the at least one first aperture in the wall portion of the armature extends generally transverse to the axial direction.
  • a lower end portion of the fuel inlet connector preferably faces an upper end portion of the armature and is configured to permit the gaseous fuel to flow from the fuel inlet connector to be directed transversely across the working gap.
  • at least a po ⁇ ion of the gaseous fuel flowing in the armature is permitted to pass through at least one second aperture in a lower wall portion thereof, the at least one second aperture extending at an acute angle to the longitudinal axis, whereby at least three separate fuel flow paths are established.
  • the injector preferably comprises a magnetic coil system and said armature is magnetically coupled to the magnetic coil system to cause the armature to move toward and away from the fuel inlet connector.
  • At least one of the fuel flow paths is located between the armature and the magnetic coil of the magnetic coil system, as well as between the armature and a valve body shell at least partially surrounding the armature.
  • the at least one first and second apertures in the armature are preferably from about 1 to about 2.0mm in diameter. Further, predetermined numbers of the first and second apertures are provided and the diameters thereof are predetermined to establish a predetermined number of fuel flow paths and volumetric flow rates thereof.
  • Fig. 1 is an elevational view, partially in cross-section, of a preferred embodiment of a compressed natural gas injector constructed according to the invention
  • Fig. 2 is an enlarged elevational cross-sectional view of the lower portion of the injector of Fig. 1. showing the improved armature and needle which forms part of the invention;
  • Fig. 3 is a partial elevational cross-sectional view of the lower end portion of the fuel inlet connector of the injector shown in Fig. 1 ;
  • Fig. 4 is a plan view of the bottom surface of the preferred fuel inlet connector shown in Fig. 1 ;
  • Fig. 5 is an elevational cross-sectional view of a preferred embodiment of the armature shown in Fig. 1 and illustrating the improved fuel flow paths resulting therefrom;
  • Fig. 6 is an elevational cross-sectional view of the upper portion of a preferred embodiment of the valve body shown in Fig. 1 ;
  • Fig. 7 is a partial elevational cross-sectional view of the lower end portion of an alternative embodiment of the fuel inlet connector shown in Fig. 3;
  • Fig. 8 is a plan view of the bottom surface of the fuel inlet connector shown in
  • Fig. 9 is an elevational cross-sectional view of an alternative embodiment of the armature shown in Fig. 5;
  • Fig. 10 is an elevational cross-sectional view of the upper portion of an alternative embodiment of the valve body shown in Fig. 6:
  • Fig. 11 is an enlarged elevational view of the armature shown in Fig. 5 and a cross-sectional view of the valve body shown in Fig. 6. incorporating an improved valve needle a fuel columnating jet flow device;
  • Fig. 12 is an enlarged elevational view, partially in cross-section, of the armature shown in Fig. 5. and the improved valve needle shown in Fig. 11 ;
  • Fig. 13 is an enlarged cross-sectional view illustrating the sealing tip portion of the valve needle as seated on the fixed valve seat as shown in Figs. 1 and 11. illustrating the preferred dimensional relationship between the needle tip. the fixed valve seat and the lower needle guide;
  • Fig. 14 is a view taken along lines 14-14 of Fig. 11, illustrating a preferred valve needle lower guide having arcuately shaped fuel passage openings.
  • a CNG injector 10 which is constructed according to the present invention. Injectors of the type contemplated herein are described in commonly assigned U.S. patent No. 5,494,224. the disclosure of which is incorporated by reference herein.
  • the injector 10 includes housing 12 containing armature 14 to which valve needle 16 is attached by crimping as will be described later in conjunction with Fig. 12.
  • Fuel inlet connector 18 includes central fuel flow opening 13 and CNG filter 20 at the upper end portion of opening 19 as shown.
  • the fuel inlet connector 18 also includes adjusting tube 22 connected thereto at 24 by a known crimping procedure.
  • Housing 12 includes inner non-magnetic shell 26 which surrounds the inlet connector 18 and armature 14 having central fuel flow opening 11 as shown.
  • Armature 14 and inlet connector 18 define with housing 12, an enclosure for coil 28 which is selectively energized to move armature 14 and needle 16 upwardly to open the valve aperture 41, and selectively deenergized to permit armature 14 and needle 16 to return to the "closed valve” position as shown, under the force of coil spring 30.
  • Fuel flow into the injector begins at filter 20 and passes through fuel inlet connector 18, to armature 14, and ultimately to valve aperture 41 of valve seat 40 into the intake manifold of the engine (not shown).
  • valve body shell 32 which is made of a ferromagnetic material and which forms part of a magnetic circuit, surrounds valve body 34 and has at the upper end. upper guide 36 as shown. Space 36a between upper guide 36 and armature 14 is about .010 to about .015mm on the diameter, and permits guiding movement of armature 14.
  • Lower O-rings 38 provide sealing between the injector 10 and the engine intake manifold (not shown) and upper O-rings 40 provide sealing between the injector 10 and the fuel rail (also not shown).
  • Valve body 34 defines central fuel flow opening 35.
  • valve body shell 32 is attached to valve body 34, preferably by weld 32a, and at the upper end by weld 26a, to non-magnetic shell 26.
  • Non-magnetic shell 26 is in turn welded to fuel inlet connector at 26b.
  • valve seat 40 contains a valve orifice 41 and a funnel shaped needle rest 42 having a frusto-conical cross-sectional shape.
  • the valve seat 40 is maintained in position by back-up washer 44 and sealed against fuel leakage with valve body 34 by O-ring 46.
  • Overmold 48 of suitable plastic material such as nylon supports terminal 50 which extends into coil 28 and is connected via connection 51 to provide selective energization of the coil to open the valve by raising the armature 14 and valve needle 16 against the force of spring 30.
  • Coil 28 is surrounded by dielectric plastic material 53 as shown in the Figs.
  • the interface space 15 (or working gap 15) between the inlet connector and the armature is extremely small, i.e. in the order of about 0.3mm (millimeters), and functions relatively satisfactorily with conventional fuels which are relatively free of contaminants such as water, solids, oil. or the like, particularly after passing through a suitable fuel filter. Accordingly, when the two surfaces surrounding space 15 are in such intimate contact that the atmosphere between them is actually displaced in relatively significant amounts, atmospheric pressures acting on the two members actually force the two surfaces together. Any liquid contaminant present at the armature/inlet connector interface would allow for the atmosphere to be displaced, thereby adversely affecting the full and free operation of the armature/needle combination.
  • the rectangular radial slots 18a are of a shallow depth, i.e. about 0.05mm. (i.e., millimeters) in order to provide the benefit of reducing the inlet connector/armature interface surface area while still providing a relatively unobtrusive location for collection of solid contaminants which are ultimately removed by the flow of gaseous CNG.
  • recessed surfaces 14a in the lowermost surface of inlet connector 18 creates raised pads 18b on the surface, which pads improve the tolerance of the injector to fuel contaminants in several ways.
  • the recessed surfaces 18a may be made by any suitable process, but are preferably coined.
  • the first effect is to reduce the contact area of the inlet connector at the armature interface, thereby significantly reducing any attractive force generated therebetween by liquid contaminants such as oil or water.
  • the radial pads 18b provide hidden areas between the pads where contaminants can collect without affecting the operative working gap 15 until being drawn away by the fuel flow.
  • the working gap for gasoline is about 0.08mm to about 0.14mm. and about 0.3mm for compressed natural gas.
  • the provision of the six rectangular recessed portions in the form of slots 18a and six raised pads 18b. each having a generally trapezoidal shape, on the inlet connector, provide a unique fuel flow path past the inlet connector/armature interface in a manner which causes the gaseous fuel to pass transversely through the working gap 15 as shown at 56 in Fig. 5 and allow for the control of the fuel flow around and through the armature by controlling the pressure losses.
  • the fuel flow can be controlled over at least three flow paths and pressure losses can also be controlled.
  • a small pressure differential across the armature while fully open assists spring 30 during breakaway upon closing and provides dampening on opening impact.
  • the additional fuel flow path also reduces the possibility of contaminants collecting above upper guide 36 as shown in Fig. 2.
  • numerous combinations of apertures and sizes thereof - as well as slots and pads on the fuel inlet connector - can be made to direct the gaseous fuel flow in any desired manner which is best for optimum fuel burning and engine application.
  • Figs. 5 and 6 in conjunction with Figs. 1-3. there is illustrated still another significant improvement, which renders the fuel injector assembly more fully capable of operation with CNG.
  • the fuel would pass through the filter down through the inlet connector into the armature and out an opening positioned relatively close to the lowest portion of the armature which was located substantially immediately above the valve aperture.
  • a relatively diagonally oriented aperture 58 shown in Fig. 5. which directs the CNG flow therethrough and downwardly toward valve aperture 41 for entry into the intake manifold of the internal combustion engine.
  • aperture 58 forms a generally acute angle with longitudinal axis A- A of the fuel injector 10.
  • the armature of the present invention provides at least one side opening 60 which is generally transverse to the longitudinal axis A-A, to permit fuel flowing downwardly through the center of the armature to be directed sidewardly out of the armature and thereafter downwardly toward the valve aperture 41 shown in Fig. 1.
  • aperture 60 is generally horizontal, but may be oriented at an acute angle to the longitudinal axis if desired.
  • Aperture 58 is not shown in the cross-sectional view of Fig. 1.
  • the fuel flowing through aperture 60 is indicated by the flow lines 62 and the fuel flowing through aperture 58 is indicated schematically by flow lines 64.
  • additional horizontal apertures 60 may be provided in the armature at different radial locations thereabout, or alternatively as shown, one aperture 60 may be provided, depending upon the fuel flow pattern sought in each particular instance. It can be seen that the fuel flow from the fuel inlet connector 18 is divided into three paths, a first path expanding across working gap 15, a second path through aperture(s) 60. and a third path through aperture(s) 58. The first path extends between the armature 14 and the magnetic coil 28 and is ultimately joined by the second flow path passing through aperture(s) 60. It can also be readily appreciated that the diameters of each aperture 58, 60 can be varied to direct the fuel flow in any predetermined desired direction.
  • apertures 58,60 fuel will be encouraged to flow with increased volume cross the working gap 15.
  • increasing the diameter of apertures 58, 60 will attract greater volume of fuel through those apertures and thereby reduce the fuel flow across the working gap.
  • the diameters of the apertures 58, 60 and the numbers and locations of such apertures affect the damping characteristics of the valve needle 16. both upon opening and upon closing. Accordingly, the diameter of fuel flow apertures 58. 60 and the numbers, locations, and orientations of such apertures will depend upon the desired volumetric flow characteristics and desired flow patterns in each instance: however diameters within the range of 1 - 2 mm have been found to be preferable.
  • a valve body 34 is also provided with central fuel flow opening 35 and several diagonally oriented fuel path apertures 66 which are intended to receive the CNG fuel flowing from the first and second flow paths from the working gap 15 and aperture(s) 60 along the sides of the armature 14 and to redirect the fuel downwardly toward the valve aperture 41 such that when the needle 16 is lifted, the fuel is permitted to enter aperture 41 and thereafter directed into the intake manifold of the engine, neither of which are shown in the drawings. Fuel flowing along the third flow path through aperture(s) 58 lead directly toward aperture 41.
  • apertures 60 may be provided in several locations about the circumference of the armature, and apertures 58 may be provided in several locations thereabout. Also their angular orientations may be varied. However, it has been found that a single aperture on each side, as shown is sufficient to produce the desired flow path and the force free environment. Also, as noted, it should be noted that the diameter of each aperture can be altered in order to provide control of the fuel pressures and flow patterns in the areas surrounding the inlet connector, the armature, and the valve body, so as to provide a predetermined fuel flow pattern throughout the injector as may be desired. This feature is more fully disclosed in the aforementioned commonly assigned, commonly filed (Attorney Docket No. 99P7610US) copending application entitled Compressed Natural Gas Injector Having Gaseous Damping for Armature Needle Assembly During Opening.
  • valve body 34 eliminates the problems of prior art injectors wherein debris and contaminants would accumulate in the area of the upper valve guide 36, causing abrasive action and intermittent guidance between the upper guide 36 and the armature 14.
  • the provision of the diagonally oriented apertures 66 in valve body 34 encourage the flow of CNG past the area surrounding the upper guide 36 and eliminate any accumulation tendencies for contaminants in the area of upper guide 36.
  • inlet connector 18 includes arcuately chamfered surface 52 on the lowermost end of inlet connector 18 as in the previous embodiment.
  • the lowermost surface of inlet connector 18 defines a surface area 67 between concentric circles 70 and 72 as shown. While the inlet connector/armature contact area is not reduced as in the embodiment of Figs. 3 and 4, the operation of the injector is improved over the prior art injectors. Accordingly, the alternative embodiment as shown in Figs.
  • FIG. 9 there is shown still another alternative embodiment of the armature configuration for use with CNG the armature in valve assembly configuration for use with CNG.
  • the armature assembly 73 contains a diagonally shaped relatively large fuel flow opening 74 at the lower portion thereof, while the horizontal fuel opening 60 in the armature of Fig. 5 has been eliminated.
  • central flow opening 75 is provided, and the diagonal fuel flow openings 66 of the embodiment of Fig. 6 have been eliminated and the fuel flow as depicted at 71 in I-ig. 10 will therefore be directed out of diagonal aperture 74 and into valve assembly 76 as shown in Figs. 9 and 10.
  • the CNG fuel path created by the combination of the inlet connector and armature shown in Figs. 7-10 represents a significant improvement over prior art structures.
  • the armature and valve assembly shown in Figs. 3-6 are preferred.
  • the structures disclosed in Figs. 7-10 produce satisfactory and improved operation and may alternatively be considered to be a preferred embodiment, depending upon the particular environment in which they are utilized. For example, in certain injectors dimensional and clearance considerations may very well create a flow pattern which will mandate a preference to utilizing the embodiments of Figs. 7-10 as opposed to the previously disclosed embodiments of Figs. 3-6.
  • Figs. 1 1 and 12 in conjunction with Figs. 1-3. there is disclosed an enlarged elevational view of the improved armature of the present invention, the improved valve body of the present invention, and the improved valve needle which has been incorporated into the disclosed structure.
  • the armature 14 contains side fuel flow aperture(s) 60 and the valve body 34 contains the diagonal CNG fuel flow path openings 66.
  • the armature 14 has attached thereto by a known crimping procedure at 78. an improved valve needle 16.
  • the improved valve components of the present fuel injector are disclosed in Figs. 1, 11 and 12 incorporating the improved needle 16.
  • the armature 14 moves upwardly and downwardly due to the energization and deenergization of coil 30 so as to produce alternating opening and closing contact between valve needle 16 and valve seat 40.
  • the needle is raised to permit the CNG fuel flow through the aperture 41 the flow passes the tip portion 17 of the needle and enters aperture 41 in its flow path toward the intake manifold of the engine.
  • the needle In conventional liquid fuel injection systems having a conventional elongated needle having a continuous cylindrically shaped outer surface, the needle presents several problems and disadvantages. When applied to CNG systems, the problems inherent with conventional needles are intensified, particularly due to the changes in the gaseous environment as compared to the liquid environment. Accordingly, the present invention incorporates a novel valve needle which improves the operation characteristics of fuel injection systems, including liquid fuel and gaseous fuel types.
  • the improved needle shown in Fig. 11 it has been found that it is desirable to provide a generous radius sealing portion 19 at the valve end of the needle in order to maximize the contact area between the valve needle 16 and the valve seat 40.
  • the greater the radius at the tip of the needle the better the sealing between the needle and the valve seat 40.
  • the radius of the spherical sealing section 19 of needle 16 is in the order of about 1.75 millimeters (i.e.. mm), or about 1.5 times the radius of the corresponding sealing surfaces in the prior art structures.
  • needles which are generally known for conventional injectors of the type disclosed herein generally have a continuous outer cylindrical configuration from the upper end to the lower end, thus requiring a needle of relatively large needle cross-sectional area in order to provide a relatively large sealing surface.
  • the needle 16 of the present invention as shown in Fig. 11 is a relatively low mass needle as disclosed, yet includes a relatively large spherical sealing surface.
  • the mass of the needle has been substantially reduced by reducing the cross-sectional dimension of the shaft 21 of the needle and retaining a tip po ⁇ ion 17 which is greater in cross-sectional dimension then the shaft of the needle as shown.
  • This configuration effectively reduces the mass of the needle while retaining the relatively large sealing diameter of spherical surface 17b of the tip portion 17 so as to provide a relatively generous radius at the tip - or free end - portion of the needle for engagement with the valve seat 40. It has been found that the relatively reduced mass of the needle and the relatively large radius of the tip portion 17 makes it possible to provide a generous spherical sealing surface 19 for the needle for a given amount of CNG flow. The generous radius also results in a shorter traveling distance for the needle 16 thereby reducing the impact velocity of the needle relative to the valve seat. It has been determined that for a predetermined flow rate, this configuration results in a significant reduction of the noise produced by the impact between the needle 16 and the valve seat 40.
  • the attenuation of the apparent noise is a result of reducing the amplitude (via reduction of lift of the needle 16) and lowering the frequency (via the greater impact radius of tip portion 17) of the noise into a less objectionable region of the sound spectrum as perceived by the human ear.
  • the improved needle of the present invention provides a larger guide surface relative to the mean needle diameter, thereby improving the wear resistance of the guiding surface of lower guide 80 shown in Fig. 1 1.
  • This improved wear resistance of the guide surface is due to the reduced loading compared to that of a conventional base valve guide diameter which was used with needles of the prior art.
  • a typical prior art needle will have a substantially continuous cylindrically shaped shaft which terminates at a radiussed end portion wherein the shaft diameter may be twice as much as the diameter of the shaft of the improved needle shown in Fig. 1 1.
  • needle 16 includes a central shaft portion and a cylindrical needle tip portion 17 having a spherical lower surface 17b which engages the frusto-conically shaped surface 42 of needle rest 40.
  • the needle is guided by upper guide 36 guiding armature 16 as shown in Fig. 1. and lower guide 80 guiding needle tip portion 17 as shown in Figs. 13 and 14.
  • Upper guide 36 is inherently required to provide a space 36a between the guiding surface and the armature 14, to permit the upward and downward motion of the armature and needle.
  • the armature 14 and needle 16 may have the tendency to shift to the left or right at the upper guide 36 within space 36a which is about .10 to about .15mm on the diameter, preferably about .13mm.
  • Fig. 13 it has been found to be advantageous to locate the center of generation 17c of spherical sealing surface 17b of needle tip portion 17 at the center of the lowermost surface of lower guide 80 as shown, in order to assure precise seating and sealing of needle 16 on frusto-conical needle rest 42.
  • the lower guide 80 tends to constrain sideward movement of the needle tip portion 17 due to movement of armature 16 within upper guide 36. and effectively becomes a nodal point about which needle tip portion 17 is capable of rotating over 360 degrees of motion.
  • any sideward movement of the needle which occurs at the level of armature 14 and upper guide 36. will cause the needle to pivot about the center point 17c and promote self seating of sealing surface 17b on needle rest 40.
  • This self-seating feature also applies in the event that any misalignment or manufacturing tolerance buildup occurs in the relationship between upper guide 36 and needle 16.
  • the present needle 16 is advantageous for use with injectors, which utilize CNG as is contemplated herein, as well as with injectors which utilize liquid fuels, such as gasoline.
  • injectors which utilize CNG as is contemplated herein
  • liquid fuels such as gasoline.
  • the motion of the valve needle is also damped by displacement of fluid across the extended valve seal face and the valve seat which further reduces the impact force and uncontrolled secondary injections upon closure caused by the valve needle when it rebounds away from the valve seat.
  • valve rebound produces quantities of low velocity fuel droplets after the needle started to close. Valve rebound dampening minimizes low volume/velocity fuel transfer to the aperture 41.
  • valve rebound dampening improves the operation of the injector by minimizing low volume/low velocity fuel transfer to the orifice and the surrounding area which tends to extendedly suspend fuel droplets via surface tension when liquid fuels are used.
  • Valve rebound dampening has also been found to be beneficial in the present injector which is contemplated for use with gaseous CNG. Referring now to Fig. 14. in conjunction with Fig. 11. lower valve needle guide
  • the aperture 80 is illustrated in the form of a disc shaped member having arcuately shaped fuel passage apertures 82 which direct the gaseous CNG in a more ellicient and effective manner as compared to prior art valve guides which utilized a plurality of circular openings formed along a circular pattern.
  • the apertures 82 are larger than the prior art circular apertures and are more effective in directing and controlling the fuel flow in an efficient manner by forming the flow pattern into several arcuate flow paths.
  • valve needle 16 crimped thereto at 78 by known crimping procedures: however, valve body 34 has been eliminated for purposes of clarity of illustration in the enlarged view of armature 14 and needle 16.
  • the illustration of needle 16 clearly shows the main shaft portion 21 and the enlarged tip portion 17 with enlarged valve spherical sealing surface 17b which conveniently engages and disengages seat area 42 of valve needle rest 40 as described in conjunction with Fig. 13.
  • the injector 10 incorporates a fuel columnating jet device 84 which includes a shallow funnel shaped section 86 connected to a generally tubular shaped columnating section 88. Gaseous fuel passing through valve aperture 41 is then allowed to pass through funnel shaped section 86. and then to be columnated into a steady gaseous stream in columnating section 88.
  • the fuel columnating device 88 enhances mixture quality, reduces fuel delivery time and enables single or multiple discharge orientation for improved gaseous flow targeting.
  • a narrow gaseous flow discharge angle can entrain the surrounding working fluid (mostly air) and can impart useful turbulent energies to directed air/fuel mixtures flowing through a port, intake valve and/or into a combustion chamber to reduce in-cylinder air/fuel mixture gradients.
  • the injector of the present invention provides improved operation for the reasons stated hereinabove by improving the flow pattern of the CNG as described, improving the control over the valve needle operation and movements thereof, and improving the sealing characteristics of the needle type valve incorporated as part of the injector.
  • noise characteristics and needle dampening both upon opening and upon closing have been significantly improved by the present invention and with the result that the injector as shown and described is significantly improved for use with compressed natural gas (CNG) fuels.
  • CNG compressed natural gas

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  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Analytical Chemistry (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • General Chemical & Material Sciences (AREA)
  • Oil, Petroleum & Natural Gas (AREA)
  • Physics & Mathematics (AREA)
  • Electromagnetism (AREA)
  • Fuel-Injection Apparatus (AREA)

Abstract

La présente invention concerne un injecteur de carburant à mise en oeuvre électromagnétique et destiné à un moteur à combustion interne. Il comporte un raccord d'aspiration de carburant (18) et une vanne (14) équipée d'une soupape à pointeau (16) qui lui est attachée et qui est disposée contre le raccord d'aspiration de carburant (18) duquel elle est séparée par un intervalle de travail (15). La vanne définit une ouverture centrale (11) de forme généralement allongée destinée à la réception du flux de carburant en provenance du raccord d'aspiration de carburant (18). Celui-ci comporte une extrémité à orifice de sortie faisant face à l'extrémité à orifice d'entrée de carburant de la vanne (14). En outre, le raccord présente une pluralité de patins surélevés disposés radialement et séparés par une pluralité correspondante de zones surbaissées disposées radialement de façon, d'une part à réduire la surface de contact entre le raccord d'aspiration de carburant et la vanne lorsque la vanne est remontée, et d'autre part à favoriser le flux de carburant dans la totalité de l'intervalle de travail en vue de l'établissement d'un premier trajet d'écoulement du carburant à l'extérieur de la vanne. Ce premier trajet d'écoulement du carburant empêche les contaminants de s'accumuler dans l'intervalle de travail (15).
PCT/US1999/011605 1998-05-27 1999-05-26 Injecteur pour gaz naturel comprime tolerant aux contaminants et organisation de la traversee de l'injecteur par le carburant gazeux WO1999061780A1 (fr)

Priority Applications (5)

Application Number Priority Date Filing Date Title
BR9911594-8A BR9911594A (pt) 1998-05-27 1999-05-26 Injetor de gás natural comprimido tolerante aos contaminadores e método para o direcionamento de combustìvel gasoso através do mesmo
KR1020007013322A KR20010043854A (ko) 1998-05-27 1999-05-26 오염물질에 대한 내성이 있는 압축천연가스 분사기 및분사기를 통하여 가스연료를 안내하는 방법
EP99930119A EP1082537B1 (fr) 1998-05-27 1999-05-26 Injecteur pour gaz naturel comprime tolerant aux contaminants et organisation de la traversee de l'injecteur par le carburant gazeux
DE69928103T DE69928103T2 (de) 1998-05-27 1999-05-26 Verunreinigungstolerantes einspritzventil für verdichtetes erdgas und verfahren zur führung von gasförmigem brennstoff durch ein solches einspritzventil
JP2000551143A JP4276383B2 (ja) 1998-05-27 1999-05-26 汚染物質を許容する圧縮天然ガス噴射器及び気体燃料を噴射器により差し向ける方法

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US8693798P 1998-05-27 1998-05-27
US60/086,937 1998-05-27

Publications (2)

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WO1999061780A1 WO1999061780A1 (fr) 1999-12-02
WO1999061780A9 true WO1999061780A9 (fr) 2000-06-08

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PCT/US1999/011605 WO1999061780A1 (fr) 1998-05-27 1999-05-26 Injecteur pour gaz naturel comprime tolerant aux contaminants et organisation de la traversee de l'injecteur par le carburant gazeux

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KR (1) KR20010043854A (fr)
WO (1) WO1999061780A1 (fr)

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6089467A (en) * 1999-05-26 2000-07-18 Siemens Automotive Corporation Compressed natural gas injector with gaseous damping for armature needle assembly during opening
US6431474B2 (en) * 1999-05-26 2002-08-13 Siemens Automotive Corporation Compressed natural gas fuel injector having magnetic pole face flux director
US8074903B2 (en) 2009-01-13 2011-12-13 Caterpillar Inc. Stator assembly and fuel injector using same
US9528648B2 (en) 2013-03-15 2016-12-27 Opw Fueling Components Inc. Breakaway assembly with relief valve

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3445405A1 (de) * 1984-12-13 1986-06-19 Robert Bosch Gmbh, 7000 Stuttgart Elektromagnetisch betaetigbares ventil
DE3905992A1 (de) * 1989-02-25 1989-09-21 Mesenich Gerhard Elektromagnetisches hochdruckeinspritzventil
US5035360A (en) * 1990-07-02 1991-07-30 The University Of Toronto Innovations Foundation Electrically actuated gaseous fuel timing and metering device
JP2660388B2 (ja) * 1993-12-29 1997-10-08 株式会社ケーヒン 電磁式燃料噴射弁
US5494224A (en) * 1994-08-18 1996-02-27 Siemens Automotive L.P. Flow area armature for fuel injector

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WO1999061780A1 (fr) 1999-12-02
KR20010043854A (ko) 2001-05-25

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