EP0744007B1 - Injecteur de carburant pour moteur a explosion a deux temps de grandes dimensions - Google Patents

Injecteur de carburant pour moteur a explosion a deux temps de grandes dimensions Download PDF

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Publication number
EP0744007B1
EP0744007B1 EP95909652A EP95909652A EP0744007B1 EP 0744007 B1 EP0744007 B1 EP 0744007B1 EP 95909652 A EP95909652 A EP 95909652A EP 95909652 A EP95909652 A EP 95909652A EP 0744007 B1 EP0744007 B1 EP 0744007B1
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EP
European Patent Office
Prior art keywords
section
slide
valve
nozzle
closing member
Prior art date
Legal status (The legal status 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 status listed.)
Expired - Lifetime
Application number
EP95909652A
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German (de)
English (en)
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EP0744007A1 (fr
Inventor
Poul Erik Larsen
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
MAN B&W Diesel GmbH
MAN B&W Diesel AS
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MAN B&W Diesel GmbH
MAN B&W Diesel AS
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Publication of EP0744007A1 publication Critical patent/EP0744007A1/fr
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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
    • F02M47/00—Fuel-injection apparatus operated cyclically with fuel-injection valves actuated by fluid pressure
    • 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
    • F02M53/00—Fuel-injection apparatus characterised by having heating, cooling or thermally-insulating means
    • F02M53/04—Injectors with heating, cooling, or thermally-insulating means
    • F02M53/043—Injectors with heating, cooling, or thermally-insulating means with cooling means other than air cooling
    • 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
    • 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
    • F02M61/042—The valves being provided with fuel passages
    • 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
    • F02M61/166—Selection of particular materials
    • 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
    • F02M61/20—Closing valves mechanically, e.g. arrangements of springs or weights or permanent magnets; Damping of valve lift
    • 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

  • the invention relates to a fuel injector for a large two-stroke internal combustion engine, such as a diesel engine for propulsion of a ship, having an elongated outer housing for mounting in a water-cooled cylinder cover in such a manner that the valve has an upper cooled valve section and a lower substantially uncooled valve section comprising at least the lower part of the fuel nozzle with transverse nozzle holes extending from a central longitudinal nozzle bore, and wherein a valve slide has an upper section carrying a movable valve part for a primary valve seat positioned in the cooled valve section and intended for opening and closing for the fuel injection, and a thin lower section extending down into the nozzle bore and carrying a secondary closing member for the fuel flow to the nozzle holes and positioned in the lower valve section.
  • Fuel injectors for four-stroke engines are known in which the primary valve seat is positioned directly above the nozzle holes, vide, for example, EP-A-0 451 408.
  • the front part of the injector with the valve seat is here cooled by the cooling water in the cylinder cover, because the latter has such a small thickness and the injector housing is so short that the cooling has effect all the way down to the tip of the injector.
  • the nozzle and the valve seat may be made of tempered steel.
  • the cylinder cover is so thick that the lower valve section of the injector extends so far from the abutment surface of the injector against the cooling cylinder cover downwards to the nozzle bores that the lower section becomes substantially uncooled and becomes heated to a high temperature by the combustion gases of the engine.
  • the temperature level is further increased in the large two-stroke internal combustion engines that are fuelled by heavy fuel oil pre-heated to a temperature of approximately 150°C. It is a well known fact by injectors in these engines that the temperature level in the protruding portion of the fuel nozzle may attain 500 to 600°C.
  • the primary valve seat in these injectors should be positioned in the upper, cooled valve section.
  • the result is that the flow passage between the primary valve seat and the nozzle holes becomes long and has a large volume, which is typically in the order of from 2 to 3 per cent of the fuel volume injected during an engine cycle.
  • the fuel amount in the passage between the valve seat and the nozzle holes is cut off from the feed pressure of the fuel. This amount of fuel can seep or drip out through the nozzle bores in the period when the injector is basically closed. As this residual amount of fuel is not atomized into the combustion chamber, only little or no combustion of the fuel is obtained.
  • the unburnt fuel leads to coking of the combustion chamber and of the downstream engine components and to an environmentally unfortunate emission of fuel with the exhaust gas, and naturally also to an increased fuel consumption.
  • the valve slide here carries a secondary closing member in the shape of a ring which, in the closed position of the injector, extends down past the nozzle holes and cuts them off, so that the amount of oil in the passage below the primary valve seat is prevented from flowing out through the nozzle holes when the injector is closed.
  • the ring slides upwards in the nozzle bore so that the nozzle holes are uncovered.
  • the central nozzle bore has a constant diameter to permit insertion and displacement of the sliding ring in the bore.
  • the injector with a secondary closing member has proved to involve a higher fuel consumption, particularly at heavy engine loads. This is presumably due to changed injection conditions when the injector is open and the oil is atomized into the combustion chamber.
  • the object of the invention is to provide a fuel injector which, despite a relatively high temperature level in the area around the nozzle holes, is able both to restrict the emission of fuel when the injector is closed, and to provide an advantageously good injection and distribution of the fuel when the injector is open.
  • the fuel injector according to the invention is characterized in that the nozzle bore has an area with a downwards diminishing diameter located in the lower valve section, that the nozzle holes extend from the bore section with a smaller diameter, that the lower section of the valve slide ends at a level above the uppermost nozzle hole, and that the secondary closing member is positioned at the area for the diminishing diameter of the bore when the slide is in its closing position.
  • the fuel injector according to the invention fulfils the above object.
  • the secondary closing member prevents the upstream amount of fuel in penetrating to the nozzle holes when the injector is closed.
  • An explanation of the reduced fuel consumption when the injector is open may presumably be found in the fact that the bore section leading to the nozzle holes has an advantageously small diameter, which provides uniform flow conditions to the nozzle holes. As the valve slide in all positions ends at a level above the nozzle holes, the fuel flow to these holes is presumably only slightly affected by the presence of a secondary closing member.
  • the primary valve seat prevents the fuel pressure on the pump side from influencing the area around the secondary closing member. There is thus no appreciable pressure drop across the closing member, which involves freedom to design it in a manner so that in its closed position, the closing member only influences the material of the fuel nozzle with extremely small forces.
  • the termination of the valve slide at a distance from the upper nozzle hole also yields the advantage that the slide tip is not influenced by the erosion forces occurring around the nozzle holes when the valve opens.
  • the secondary closing member has a cylindrical section which may slide sealingly into the section with a smaller diameter of the nozzle bore.
  • the cylindrical section When the slide is moved downwards towards the closing position, the cylindrical section is displaced into the narrower lower section of the nozzle bore so that the flow connection between the nozzle holes and the broader upstream section of the nozzle bore is interrupted.
  • the cylindrical section only affects the nozzle itself with the small frictional force which occurs when the surfaces slide past each other. In the closed position of the injector, the cylindrical section is received inside the lower section of the nozzle bore without the nozzle being affected by closing forces proper.
  • the thin lower section of the valve slide with the secondary closing member is a rigid extension of the upper section of the slide.
  • the rigidity of the thin section causes the slide tip to be kept coaxial with the upper section of the slide and thus also coaxial with the nozzle bore.
  • the thin lower section of the valve slide is a transversely flexible extension of its upper section, and at a level above the secondary closing member, the lower section has a guide which centres the closing member in the nozzle bore by abutment against the wall of the section of the bore with a larger diameter.
  • the separate guide for centring the slide tip is, of course, more difficult to manufacture than a cylindrical, smooth lower section, but in return there is no need for the lower section of the slide to be aligned with the upper section, as the tip of the slide is self-centring in the nozzle bore. This substantially facilitates the mounting of the slide in the injector and ensures good centring of the slide tip even after long-term operation.
  • the self-aligning slide tip is especially advantageous in the cases where the lower section of the slide is a separate replaceable unit.
  • the guide is designed as several radially extending longitudinal fins on the lower section of the slide, and the upper and lower ends of the fins are preferably pointed.
  • the longitudinal fins only slightly disturb the downward flow of fuel when the injector is open. The flow disturbances can be further diminished by making the ends of the fins pointed so that the flow achieves a smooth runoff from the fins.
  • the lower free end of the slide may suitably be conical so that not too many eddies are started in the fuel when it changes at the passage of the secondary closing member from flowing around the slide to itself filling out the whole of the cross-section of the bore.
  • the fuel is gaseous
  • it may be suitable to design the injector so that the secondary closing member in its closed position abuts an inclined surface in the area of the bore with a diminishing diameter, and that said closing member is displaceable in the longitudinal direction of the slide and spring-loaded for movement away from the upper section of the slide.
  • the inclined surface acts as a valve seat, but as a result of the displaceability of the secondary closing member in relation to the upper section of the slide, the closing member cannot be pressed against the seat with more than the force produced by the associated spring.
  • the spring force may be adapted to the strength of the material in the nozzle, that is, the spring force may, for example, be chosen to be so small that the closing member largely puts no load on the seat material.
  • the lower thin section of the valve slide with the secondary closing member is a separate unit, which is removably fastened to the upper section.
  • This renders it possible to replace the secondary closing member independently of the upper section of the slide, and furthermore an advantage in manufacturing is obtained in that the two sections can be manufactured separately, that is, also in individual materials, if it is desired that the closing member is of a more temperature-resistant material than the upper section of the slide.
  • the area of the nozzle bore with a diminishing diameter is preferably substantially closer to the nozzle holes than to the primary valve seat. This limits the volume of the nozzle bores below the secondary closing member.
  • the latter may suitably be designed so that the secondary closing member only opens the section of the nozzle bore with a smaller diameter when the movable valve part of the slide has been moved a predetermined distance away from the primary valve seat.
  • the pressure of the fuel in the section of the nozzle bore with a larger diameter may be raised to a suitably high pressure, before the closing member opens for the passage of fuel to the bore leading to the nozzle holes.
  • the delay in the opening of the closing member can be adjusted in one embodiment via the length of the cylindrical section which can slide sealingly into the nozzle bore, and in another embodiment, the delay is adjusted by means of the position of a stop which pulls a displaceable closing member along in the movement of the slide.
  • Fig. 1 shows a fuel injector or fuel valve generally designated 1 with an upper flange 2 for fastening the injector in the engine.
  • the flange has an upward connecting piece 3 to which may be fastened a pressure pipe, not shown, which feeds pressurized fuel from a suitable source, such as a fuel pump or a high-pressure reservoir.
  • the injector has a nozzle 4.
  • the fuel may be passed from the connection at the connecting piece 3 down towards the nozzle 4 through an upper flow passage 5, which passes from a central bore 6 in the connecting piece through a spring guide 7 and a circulation slide 8 down to a pressure chamber 9 delimited by the slide 8 and a guide 10 for the latter.
  • the fuel may flow further down towards the nozzle through a middle flow passage 12 in the form of a central bore in a pressure pipe 13, a pressure piece 14 and a valve slide 15, in which the central bore is connected with a primary pressure chamber 16 through several inclined bores 17.
  • the middle flow passage ends downwards at a primary valve seat 18.
  • the fuel may flow onwards through a lower flow passage 19 in the form of a central bore 20 ( vide Fig. 2) at the bottom of a slide guide 21 for the valve slide 15 and a nozzle bore coaxial therewith.
  • the central longitudinal nozzle bore comprises an upper bore section 22 with a larger diameter, which merges through an area 23 with a diminishing diameter into a lower bore section with a smaller diameter, from which nozzle holes 24 extend as shown in the subsequent figures.
  • the injector in Fig. 1 is intended for the injection of oil, particularly heavy fuel oil.
  • the oil pressure in the upper flow passage 5 and in the pressure chamber 9 increases so that the circulation slide 8 is moved upwards and cuts off the transverse circulation passage.
  • the flow passage past the seat 11 opens, and the pressure spreads down through the middle flow passage 12 and the inclined bores 17 to the primary pressure chamber 16.
  • a compression spring 25 bears on an upper spring disc 26 and presses downwards via a lower spring disc 27 on the valve slide 15, so that a valve part 28 which is in the shape of an annular conical surface on the valve slide and is movable in relation to the primary valve seat 18, is pressed sealingly against the valve seat 18.
  • the movable valve part 28 delimits the upper section of the valve slide 15 from a thin lower section 30 of the slide.
  • the lower section 30 is cylindrical and has a diameter which is slightly smaller than the diameter of the section 29 of the nozzle bore with smaller diameter, so that the lower section 30 of the slide can slide sealingly into the lower bore section 29.
  • the pressure is built up by opening of the valve in the upper bore section 22, before the lower section 30 of the slide is lifted out of the bore section 29, whereby an opening is made for the oil flow to the nozzle holes.
  • the pressure build-up in the oil before the final passage to the nozzle holes promotes the fine atomization of the oil at the initiation of the atomization.
  • the nozzle holes not shown in Fig. 1 are positioned at the end of the bore section 29, that is, several bore diameters away from the lower conical tip of the valve slide 15 when the slide is in its closed position as shown.
  • the lower section 30 of the valve slide has a substantially constant diameter, but only needs accurate machining on the lowest portion, which acts as a closing member 32 and slides into the lower section 29 of the nozzle bore.
  • the lower section 30 of the valve slide 15 is formed integrally with the upper section of the valve slide and as a rigid extension thereof, whereby, without any further guidance than the positioning of the upper slide section in the slide guide 21, the lower section 30 is centred in relation to the nozzle bore.
  • an abutment surface 31 at the front end of the injector housing 2a is clamped down against a conical surface facing upwards on the cylinder cover of the engine.
  • This abutment surface is the lowest place where the injector is exposed to a substantial cooling effect, which occurs because the cover is cooled by a coolant circulating in the engine and keeping the cover temperature at the abutment surface 31 at, for example, 80°C.
  • the temperature of the injector corresponds largely to the temperature of the oil which circulates in the injector and may be preheated to, for example, 120-150°C.
  • the nozzle section located below the inclined abutment surface 31 is in contact with the high temperatures in the combustion chamber of the cylinder.
  • the lowest part of the nozzle is thus in practice uncooled.
  • the valve 1 may be said to be divided into an upper cooled valve section la positioned above the abutment surface 31 and a lower, substantially uncooled valve section 1b extending from the lower end of the nozzle 4 and up close to the abutment surface 31.
  • the nozzle 4 is of a high-temperature-resistant material which can also resist the erosion influences of the fuel in the area around the nozzle holes.
  • the nozzle is manufactured from, for example, Stellite 6 or another high-temperature-resistant alloy, such as INCONEL ALLOY ma758 as described in EP-A-0 569 655.
  • both the closing member 32 and the upper portion of the section 29 of the bore are positioned in the uncooled valve section 1b.
  • both the closing member 32 largely does not influence the material of the nozzle with forces acting in the longitudinal direction, both the closing member and the nozzle have long lives despite the high temperature level.
  • the second embodiment of the fuel injector shown in Figs. 2. and 3 is also intended for an engine using oil as fuel.
  • the thin lower section 30 of the valve slide is here a separate replaceable unit which at its upper end has an external thread screwed up into an internal thread in a central bore 40 at the lower end of the upper section of the valve slide, until a collar 41 on the lower section 30 abuts the end surface of the upper section.
  • a locking pin 45 inserted in aligned bores in the upper and lower sections of the slide locks the lower section 30 against rotation in relation to the upper section of the slide. If the lower slide section 30 gets worn or damaged, the locking pin 45 may be removed, and the lower section 30 may be replaced by a new one. This avoids replacement of the whole slide.
  • the lower section 30 is elongated, thin and flexible in the transverse direction seen in relation to the upper section of the valve slide.
  • the closing member 32 formed by the front cylindrical portion of the section 30 projects down into the bore section 29 and prevents the oil in the upper bore section 22 from penetrating to the nozzle holes 24.
  • the amount of oil in the bore section 29 below the tip of the valve slide amounts to about 10 per cent of the total amount of oil present below the primary valve seat 18.
  • the closing member 32 is centred in the nozzle bore by means of a guide 42, which slides along a guiding surface 43 in the nozzle bore.
  • the guide 42 consists of several, for example four, radially extending, longitudinal fins, the upper and lower ends of which are pointed. The oil can flow past the guide 42 through the longitudinal spaces between the fins.
  • valve slide 15 is shown in its fully open position, where the oil flows past the primary valve seat 18 and down into the nozzle bore, where the oil in the area 23 with a diminishing diameter flows past the conical free end 44 of the valve slide and flows on down to the nozzle holes 24 as a joint flow covering the full cross-section of the nozzle bore.
  • the distance between the free end 44 of the slide and the nozzle holes is presumably so large that the oil flow down into the nozzle holes is substantially undisturbed by the fact that the lower section 30 of the slide extends far down into the nozzle bore.
  • the number of nozzle holes 24 at the tip of the nozzle depends on the power to be yielded by the working cylinder of the engine and of the number of injectors per cylinder. There may be, for example, four or five nozzle holes which all open out on the same side of the nozzle, so that the longitudinal axes of the two outermost nozzle holes form a mutual angle of not more than 100° and often only of 80° or less.
  • the oil is thus atomized into a fan-shaped mist of finely distributed oil particles.
  • injectors for injection of gaseous fuel will be described.
  • the injectors are constructed in the same manner as described above except for the fact that the valve slide is lifted by means of control oil which influences a piston area adapted for the purpose on the slide, and that the gas is supplied sideways into the lower part of the valve housing through an inlet conduit 50 in the cover indicated by 51 and an oblique conduit 52 in the valve housing 33.
  • the oblique conduit 52 opens out into a pressure chamber 53 which is positioned directly above the primary valve seat 18.
  • the construction and the mode of operation of such a gas injector is well-known in the art.
  • the injector must inject a relatively large volume of gas during an engine cycle.
  • the flow passages in the injector therefore must have a suitably large cross-sectional area, which means that the nozzle bore and thus also the nozzle itself have a large diameter.
  • the injector abutment surface 31' which is pressed against a cooling conical surface on the cover 51, is therefore formed on the nozzle 4 itself so that the outer diameter of the injector housing may be kept suitably small. Otherwise it appears from Fig. 4 that near the surface 54 the cover has cooling channels 55.
  • the portion of the nozzle positioned below the abutment surface 31' is affected by the very high temperature level in the combustion chamber 56 and is in practice uncooled.
  • the closing member on the lower section 30 of the valve slide abuts a conical inclined surface 57 in the area of the bore with a diameter diminishing downwards.
  • the closing member may be a valve needle 58, as shown in Figs. 4 and 5, or a ball-shaped valve member 59, as shown in Figs. 6 and 7.
  • the closing member is not pressed against the inclined surface 57 with a valve closing force of the same magnitude as the closing force acting on the primary valve seat 18, but is only biased towards a closed position by a weak compression spring.
  • a weak compression spring may, for example, be a compression spring 61 which is received in a cavity in the upper section of the valve slide and presses on the whole lower slide section 30, which is displaceably positioned in a central bore in the upper section, or it may be a compression spring 60 ( vide Figs. 6 and 7) which surrounds the lower slide section 30 and acts on the valve portion 59 which is longitudinally displaceably positioned on the lower section 30.
  • the displaceably positioned slide section 30 shown in Figs. 4 and 5 carries one part of a bayonet coupling, for example several projecting fins at its upper end. These fins may be passed up through corresponding grooves at the end of the upper section of the valve slide. When the fins have been passed into the cavity, the lower section may be turned to its mounted position where, by abutting the bottom of the cavity, the bottom side of the fins acts as a stop to the downward displacement of the section 30 in relation to the upper section of the valve slide.
  • a bayonet coupling for example several projecting fins at its upper end. These fins may be passed up through corresponding grooves at the end of the upper section of the valve slide.
  • the lower section When the fins have been passed into the cavity, the lower section may be turned to its mounted position where, by abutting the bottom of the cavity, the bottom side of the fins acts as a stop to the downward displacement of the section 30 in relation to the upper section of the valve slide.
  • valve portion 59 shown in Figs. 6 and 7 is restricted in its displacement away from the upper section of the valve slide by a stop in the form of a collar 62 which catches a thickened lower portion of the slide section 30.
  • the secondary closing member is in its closing position positioned at level with the ceiling of the combustion chamber.

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  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Fluid Mechanics (AREA)
  • Fuel-Injection Apparatus (AREA)
  • Nozzles (AREA)

Abstract

Injecteur de carburant (1) pour moteur à explosion à deux temps de grandes dimensions. L'injecteur comporte un corps externe allongé (2) devant être monté dans une enveloppe de cylindre (51) à refroidissement par eau. Un premier siège de soupape (18) servant à ouvrir et fermer l'injecteur de carburant est placé dans une section supérieure refroidie (1a) de la soupape, alors qu'un second élément obturateur (32) pour le débit de carburant en direction des orifices (24) de la buse est placé dans la buse (4) dans une section non refroidie (1b) de la soupape. Le perçage de la buse comporte une section supérieure (22) dont le diamètre est supérieur à celui d'une section inférieure (29) comprenant lesdits orifices. Le second élément obturateur est placé dans une zone (23) où le diamètre diminue progressivement, lorsque le tiroir (15) de la soupape est en position fermée. D'un côté, l'élément obturateur isole des orifices de la buse la majeure partie du volume de carburant dans le perçage de la buse, lorsque la soupape est fermée, et de l'autre côté, le tiroir de la soupape s'arrête à une certaine distance desdits orifices afin que la section inférieure (30) du tiroir ne puisse gêner l'atomisation lorsque l'injecteur est ouvert.

Claims (10)

  1. Injecteur de carburant (1) pour moteur à explosion deux temps de grande taille, par exemple un moteur diesel pour propulsion d'un navire, comportant un boîtier externe allongé (33) pour montage dans un chapeau de cylindre (51) à refroidissement par eau, de telle manière que la soupape (1) présente une section supérieure refroidie de soupape (1a) et une section inférieure de soupape (1b), essentiellement non-refroidie, comprenant, au moins, la partie inférieure de l'ajutage de carburant (4) avec des orifices transversaux d'ajutage (24) s'étendant depuis un alésage central longitudinal d'ajutage, et où un tiroir (15) de soupape comporte une section supérieure portant une pièce mobile de soupape (28) pour un siège primaire de soupape (18), situé dans la section refroidie de soupape, pour ouvrir et fermer l'injection de carburant, et une section inférieure mince (30), qui s'étend vers le bas dans l'alésage d'ajutage (22, 23, 29) et qui, dans la section inférieure de soupape, porte une pièce secondaire de fermeture de l'écoulement de carburant aux orifices d'ajutage, caractérisé en ce que l'alésage d'ajutage présente une zone (23) dont le diamètre va en diminuant vers le bas et qui est située dans la section inférieure de soupape (1b), en ce que les orifices d'ajutage (24) s'étendent depuis la section d'ajutage (29) à diamètre réduit, en ce que la section inférieure (30) du tiroir de soupape se termine à un niveau situé au-dessus de l'orifice supérieur d'ajutage, et en ce que la pièce secondaire de fermeture (32; 58; 59) se trouve située dans la zone (23) de l'alésage, dont le diamètre va en diminuant, lorsque le tiroir (15) se trouve dans sa position de fermeture.
  2. Injecteur de carburant selon la revendication 1, caractérisé en ce que la pièce secondaire de fermeture (32) présente une partie cylindrique qui, de façon étanche, peut glisser dans la section (29) de l'alésage d'ajutage à diamètre réduit.
  3. Injecteur de carburant selon les revendications 1 ou 2, caractérisé en ce que la section inférieure mince (30) du tiroir de soupape avec la pièce secondaire de fermeture (32) forme un prolongement rigide de la section supérieure.
  4. Injecteur de carburant selon les revendications 1 ou 2, caractérisé en ce la section inférieure mince (30) du tiroir de soupape est un prolongement transversalement flexible de sa section supérieure, et en ce qu'à un niveau au dessus de la pièce secondaire de fermeture (32), la section inférieure comporte un guide (42) qui centre la pièce de fermeture dans l'alésage d'ajutage par appui contre la paroi de la section (22) de l'alésage à diamètre plus grand.
  5. Injecteur de carburant selon la revendication 4, caractérisé en ce que le guide (42) comporte plusieurs ailettes longitudinales, s'étendant radialement, sur la section inférieure (30) du tiroir, et en ce que les extrémités supérieure et inférieure des ailettes sont, de préférence, pointues.
  6. Injecteur de carburant selon la revendication 1, caractérisé en ce que dans sa position fermée, la pièce secondaire de fermeture (58; 59) est en butée contre une surface inclinée (57) dans la zone (23) de l'alésage, dont le diamètre va en diminuant, et en ce que ladite pièce de fermeture est déplaçable dans le sens longitudinal du tiroir et chargée par ressort pour mouvement s'éloignant de la section supérieure du tiroir (15).
  7. Injecteur de carburant selon l'une quelconque des revendications précédentes, caractérisé en ce que la section inférieure mince (30) du tiroir de soupape avec la pièce secondaire de fermeture (32; 58; 59) est un ensemble séparé, monté, de façon amovible, sur la section supérieure.
  8. Injecteur de carburant selon l'une quelconque des revendications précédentes, caractérisé en ce que la zone (23) de l'alésage d'ajutage, dont le diamètre va en diminuant, se trouve, de préférence, essentiellement plus proche des orifices d'ajutage (24) que du siège primaire de soupape (18).
  9. Injecteur de carburant selon l'une quelconque des revendications précédentes, caractérisé en ce que la pièce secondaire de fermeture n'ouvre la section (29) de l'alésage d'ajutage à diamètre réduit que lorsque la pièce mobile de soupape (28) du tiroir a été déplacée d'une distance prédéterminée depuis le siège primaire de soupape (18).
  10. Injecteur de carburant selon l'une quelconque des revendications précédentes, caractérisé en ce que l'extrémité inférieure libre (44; 58) du tiroir est conique.
EP95909652A 1994-02-07 1995-02-06 Injecteur de carburant pour moteur a explosion a deux temps de grandes dimensions Expired - Lifetime EP0744007B1 (fr)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
DK015694A DK171975B1 (da) 1994-02-07 1994-02-07 Brændselsinjektor til en stor totakts forbrændingsmotor
DK156/94 1994-02-07
PCT/DK1995/000053 WO1995021324A1 (fr) 1994-02-07 1995-02-06 Injecteur de carburant pour moteur a explosion a deux temps de grandes dimensions

Publications (2)

Publication Number Publication Date
EP0744007A1 EP0744007A1 (fr) 1996-11-27
EP0744007B1 true EP0744007B1 (fr) 1997-10-22

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EP95909652A Expired - Lifetime EP0744007B1 (fr) 1994-02-07 1995-02-06 Injecteur de carburant pour moteur a explosion a deux temps de grandes dimensions

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EP (1) EP0744007B1 (fr)
JP (1) JP3081646B2 (fr)
KR (1) KR100335666B1 (fr)
CN (1) CN1057366C (fr)
DE (1) DE69500921T2 (fr)
DK (1) DK171975B1 (fr)
ES (1) ES2109094T3 (fr)
HR (1) HRP950053B1 (fr)
PL (1) PL175740B1 (fr)
WO (1) WO1995021324A1 (fr)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0961024A1 (fr) * 1998-05-29 1999-12-01 Wärtsilä NSD Schweiz AG Buse d'injection de combustible
DE10129308C1 (de) * 2001-06-18 2002-11-28 Man B & W Diesel As Kopenhagen Vorrichtung zur Brennstoffversorgung von Brennkraftmaschinen

Families Citing this family (16)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DK174075B1 (da) * 1996-06-20 2002-05-21 Man B & W Diesel As Brændselsinjektor til en forbrændingsmotor
AU5026699A (en) * 1998-07-24 2000-02-21 Man B&W Diesel A/S A fuel valve for an internal combustion engine
DE10019153A1 (de) * 2000-04-18 2001-10-25 Bosch Gmbh Robert Kraftstoffeinspritzventil für Brennkraftmaschinen
WO2005008059A1 (fr) * 2003-07-17 2005-01-27 Ganser-Hydromag Ag Soupape d'injection de carburant pour moteurs a combustion interne
JP2005315101A (ja) * 2004-04-27 2005-11-10 Isuzu Motors Ltd ガス燃料用噴射弁
CN100351512C (zh) * 2004-07-15 2007-11-28 于魁江 电控喷油器
JP4161974B2 (ja) * 2005-03-28 2008-10-08 トヨタ自動車株式会社 ディーゼル式内燃機関の制御装置
JP5312148B2 (ja) * 2009-03-30 2013-10-09 株式会社ケーヒン 燃料噴射弁
KR101603029B1 (ko) * 2012-02-07 2016-03-11 간제르-히드로막 아게 연료 분사 밸브 및 연료 분사 장치
DE102012208087B4 (de) * 2012-05-15 2024-03-14 Man Energy Solutions Se Kraftstoffeinspritzdüse
DK178692B1 (en) * 2015-04-22 2016-11-21 Man Diesel & Turbo Filial Af Man Diesel & Turbo Se Tyskland A fuel valve for a large two-stroke self-igniting internal combustion engine
CN106321315A (zh) * 2016-11-24 2017-01-11 余姚市舒春机械有限公司 一种船用大功率柴油机喷射装置
DK179146B1 (en) * 2016-12-13 2017-12-04 Man Diesel & Turbo Filial Af Man Diesel & Turbo Se Tyskland Nozzle for fuel valve for injecting fuel into the cylinders of a large turbocharged two-stroke compression-ignited internal combustion engineand and an engine therefore
DK179281B1 (en) * 2016-12-13 2018-04-03 Man Diesel & Turbo Filial Af Man Diesel & Turbo Se Tyskland Nozzle for fuel valve for injecting fuel into the cylinders of a large turbocharged two-stroke compression-ignited internal combustion engine
SE540338C2 (en) * 2016-12-22 2018-07-10 Scania Cv Ab Fuel injector
DK180809B1 (en) * 2020-12-09 2022-04-07 Man Energy Solutions Filial Af Man Energy Solutions Se Tyskland Internal combustion engine

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DE2837606A1 (de) * 1978-08-29 1980-03-06 Daimler Benz Ag Mehrstrahliges einspritzventil
JPS58113575A (ja) * 1981-12-28 1983-07-06 Komatsu Ltd エンジンの燃料噴射装置
IT1240173B (it) * 1990-04-06 1993-11-27 Weber Srl Dispositivo di iniezione del carburante ad azionamento elettromagnetico per un motore a combustione interna
DE4025945C2 (de) * 1990-08-16 1998-10-08 Bosch Gmbh Robert Verfahren zur Einstellung eines Brennstoffeinspritzventils und Brennstoffeinspritzventil
DK167502B1 (da) * 1991-10-04 1993-11-08 Man B & W Diesel Gmbh Braendselsinjektor til forbraendingsmotorer

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0961024A1 (fr) * 1998-05-29 1999-12-01 Wärtsilä NSD Schweiz AG Buse d'injection de combustible
DE10129308C1 (de) * 2001-06-18 2002-11-28 Man B & W Diesel As Kopenhagen Vorrichtung zur Brennstoffversorgung von Brennkraftmaschinen

Also Published As

Publication number Publication date
CN1057366C (zh) 2000-10-11
WO1995021324A1 (fr) 1995-08-10
DE69500921D1 (de) 1997-11-27
DE69500921T2 (de) 1998-03-12
HRP950053B1 (en) 1998-12-31
EP0744007A1 (fr) 1996-11-27
PL175740B1 (pl) 1999-02-26
KR960706605A (ko) 1996-12-09
PL315808A1 (en) 1996-12-09
KR100335666B1 (ko) 2002-11-23
ES2109094T3 (es) 1998-01-01
JP3081646B2 (ja) 2000-08-28
JPH09508456A (ja) 1997-08-26
DK171975B1 (da) 1997-09-01
CN1140483A (zh) 1997-01-15
HRP950053A2 (en) 1997-02-28
DK15694A (da) 1995-08-08

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