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Dokumentenidentifikation EP1387938 28.12.2006
EP-Veröffentlichungsnummer 0001387938
Titel KRAFTSTOFFEINSPRITZANORDNUNG
Anmelder Wärtsilä Finland Oy, Vaasa, FI
Erfinder LEHTONEN, Kai, FIN-65280 Vaasa, FI;
JAY, David, FIN-66500 Vähäkyrö, FI
Vertreter derzeit kein Vertreter bestellt
DE-Aktenzeichen 60216075
Vertragsstaaten AT, BE, CH, CY, DE, DK, ES, FI, FR, GB, GR, IE, IT, LI, LU, MC, NL, PT, SE, TR
Sprache des Dokument EN
EP-Anmeldetag 18.04.2002
EP-Aktenzeichen 027142637
WO-Anmeldetag 18.04.2002
PCT-Aktenzeichen PCT/FI02/00323
WO-Veröffentlichungsnummer 2002092994
WO-Veröffentlichungsdatum 21.11.2002
EP-Offenlegungsdatum 11.02.2004
EP date of grant 15.11.2006
Veröffentlichungstag im Patentblatt 28.12.2006
IPC-Hauptklasse F02M 47/02(2006.01)A, F, I, 20051017, B, H, EP

Beschreibung[en]
Technical Field

The invention relates to a fuel injection arrangement according to the preamble of claim 1.

Background Art

The fuel injection has a very big influence on operation and combustion of a diesel engine. The so-called common rail fuel injection has been developed in order to enhance the control of the combustion. One of the systems of this kind, applied especially to large engines, has been disclosed in EP 959245.

One of the factors having a particularly big influence on the operation of the engine is the successful operation and control of the injection nozzles.

Disclosure of the Invention

An objective of the invention is to provide a fuel injection arrangement, by which the operation of the common rail injection is reliable and by which the risk of leakage of the injection nozzles to the combustion chamber can be minimized.

The objectives of the invention can be achieved in a way that is described in more detail in claim 1 and in other claims.

The fuel injection arrangement according to the invention comprises:

  • a fuel source and a fuel nozzle connected thereto, which fuel nozzle includes a fuel chamber and a needle valve arrangement in connection with the fuel chamber for controlling the fuel injection and an arrangement for bringing about a force effect on the valve of the needle valve arrangement in the closing direction thereof,
  • a fuel control arrangement, by means of the different switching positions of which, the fuel flow connection is connectable between the fuel source and the fuel chamber of the fuel nozzle as well as between the fuel source and the arrangement for bringing about a force effect, in which injection arrangement the fuel control arrangement comprises a mechanical force unit in order to change its switching positions.

The fuel control arrangement advantageously comprises a valve element, the position of the stem of which determines the operational state of the injection arrangement. There is a mechanical force unit connected to the stem, by which the stem is displaceable between the first position, in which the valve element closes the flow connection between the fuel source and the fuel chamber of the needle valve arrangement and connects the fuel chamber of the needle valve arrangement to a space allowing the lowering of its pressure, and the second position, in which there is a flow connection between the fuel source and the fuel chamber of the needle valve arrangement. According to the invention, between the first and second position the stem has an intermediate position, in which the fuel flow connection is connected from the fuel source to the arrangement for bringing about a force effect on the valve of the needle valve arrangement.

The mechanical force unit comprises a stem arrangement displaceable by electric power, which is connected to the stem of the valve arrangement. The mechanical force unit further comprises a spring arrangement or similar, which subjects the stem of the valve element to a force tending to move it to a direction which opens the needle valve arrangement.

Disclosure of Drawings

In the following, the invention will be described, by way of example, with reference to the accompanying drawings, in which

  • Figure 1 shows schematically the fuel injection arrangement according to the invention in the first position,
  • Figure 2 shows schematically the fuel injection arrangement according to the invention in the intermediate position, and
  • Figure 3 shows schematically the fuel injection arrangement according to the invention in the second position.

In Figure 1, the reference numeral 1 corresponds to the fuel injection arrangement. The arrangement comprises a common rail storage 2 as the fuel source. The fuel in the common rail storage is ready in a pressurized state to be injected to the combustion chamber of the engine through a fuel nozzle 3. The fuel nozzle 3 includes a fuel chamber 4, from which fuel is injected to the engine cylinder, in connection with which the nozzle has been arranged (not shown in the Figure). The fuel nozzle also comprises a needle valve arrangement 5 for controlling the fuel injection. There is arranged, fitted with the fuel nozzle, an arrangement for bringing about a force effect 6 on the valve of the needle valve arrangement in the closing direction thereof. This arrangement 6 comprises a piston unit 6', by which the force closing the needle valve can be directed into it.

The arrangement further comprises a fuel control arrangement 7, by which the fuel flow connection is connectable between the fuel source 2 and the fuel chamber 4 of the fuel nozzle 3 as well as between the fuel source 2 and the arrangement for bringing about the force effect 6. With this arrangement, between the switching on and off of the fuel feed, a force can be directed to the needle valve arrangement in the closing direction thereof, in which case the closure of the needle is assured after the injection. The solution has also other advantages, which appear in the following description of the fuel control arrangement 7.

The control arrangement 7 comprises a valve element, the stem 8 of which has been arranged to move in the direction of its longitudinal axis in the body of the valve element 14. The stem 8 and the body 14 define together two seat surfaces 9 and 10, which separate the three fuel spaces 11, 12 and 13 of the valve element. In the first position of the stem, the stem 8 of the valve element closes the flow connection between the fuel source 2 and the needle valve arrangement 5 and connects the fuel chamber 4 of the needle valve arrangement 5 to a space allowing the lowering of its pressure 15. This situation has been represented in Figure 1. The common rail storage 2 is connected by a duct 2' to the fuel space 11 of the control arrangement 7, which in this position of the stem is closed from the fuel space 1 2 by a seat surface 9. A connecting duct 12' has been arranged from the fuel space 12 into the fuel chamber 4 of the valve element. The fuel space 1 2 is still in this position of the stem 8, via an open seat surface 10, connected to the fuel space 13, which is connected to the piston unit space 6'. There is a further connection from the piston unit space 6' into the space 15 via duct 13". The duct 13" is advantageously equipped with a throttling element 13"' in order to restrict the flow.

For controlling the position of the stem 8 of the valve element a mechanical force unit 16, 17 is arranged, which comprises a stem arrangement 16 displaceable by electric power, fitted to the first end of the stem 8 and a spring arrangement 17, which is fitted to the second opposite end of the stem 8. With the interaction of the stem arrangement 16 displaceable by electric power and the spring arrangement 17, the stem 8 can be placed in two different positions and in the intermediate position thereof. The first position of the stem 8 has been shown in the Figure 1. In this position, the feed from the common rail storage 2 is closed and the fuel chamber 4 is in connection with the space 15 through the fuel spaces 12 and 13, as well as via the piston unit 6', in order to lower the pressure from the fuel chamber 4. This means that the needle valve arrangement 5 is closed.

The intermediate position of the control arrangement 7, in which the fuel flow connection is connected to the arrangement for bringing about the force effect 6, has been represented in Figure 2. By means of a mechanical force unit 16, such a force has been applied against the force of the spring 17 that the stem 8 has shifted to the position showed in Figure 2. Consequently, this position is the inter-mediate position of the stem before the third position, or before the first, depending on each moving direction of the stem. In the intermediate position illustrated in Fig-ure 2, the stem 8 is in such a position that both seat surfaces 9 and 10 are open, in which case the pressure of the common rail storage 2 has an effect on the valve needle and to the upper side thereof by means of the piston unit 6' as well as to the lower side thereof, in the fuel chamber 4. This guarantees that the needle remains closed before the injection. In this situation, some fuel flows out of the system through the duct 13", but the throttling 13"' has been selected to be such, that this amount is not excessive.

Figure 3 shows a situation in which the fuel injection is in operation. Now the stem 8 is in a position, in which the seat surface 10 is closed, but the seat surface 9 is open. This means that the common rail storage 2 is in connection through the fuel space 12 with the fuel chamber 4 and when the seat surface 10 is simultaneously closed up, the pressure may fall in the piston unit 6' when it is in connection with the space 15 through the duct 13". When the injection is to be halted, the stem 8 is displaced through the position represented in Figure 2 into the position illustrated in Figure 1 assisted by the force unit 16. Among other things, this provides the reli-able closure of the valve needle as a result of the high pressure of the common rail storage led into the piston unit 6'.

The arrangement also comprises a constant pressure valve 19, by which the pressure acting on the piston unit 6' is maintained at a certain level. By mechanically changing the position of the stem 8, the possibility of the stem 8 to get stuck is minimized, but if the stem 8 stays in an intermediate position, the needle valve arrangement 5 will close, because the pressure of the common rail storage 2 has also a valve closing influence through the piston unit 6'. This way the leaking of the fuel from the needle valve arrangement into the engine cylinder does not occur. The arrangement also comprises the ducts 18 and 18' for discharging the fuel out of the spaces remaining between the ends of the body and the stem.


Anspruch[de]
Kraftstoffeinspritzanordnung (1), mit: - einer Kraftstoffquelle (2) und einer mit dieser verbundenen Kraftstoffdüse (3), die eine Kraftstoffkammer (4) und eine Nadelventilanordnung (5) in Verbindung mit der Kraftstoftkammer zur Steuerung der Kraftstoffeinspritzung und eine Anordnung (6) zur Bewirkung einer Kraftwirkung an dem Ventil der Nadelventilanordnung in der Schließrichtung desselben aufweist, - einer Kraftstoffsteueranordnung (7), durch deren unterschiedliche Schaltstellungen die Kraftstoffströmungsverbindung zwischen der Kraftstoffquelle (2) und der Kraftstoff kammer (4) der Kraftstoffdüse sowie zwischen der Kraftstoffquelle (2) und der Anordnung (6) zur Bewirkung einer Kraftwirkung verbunden werden kann, wobei die Kraftstoffsteueranordnung (7) eine mechanische Krafteinheit (16, 17) aufweist, um ihre Schaltstellungen zu ändern. Kraftstoffeinspritzanordnung nach Anspruch 1, dadurch gekennzeichnet, dass die Kraftstoffsteueranordnung (7) ein Ventilelement aufweist, wobei die Stellung des Schafts (8) desselben den Arbeitszustand der Einspritzungsanordnung bestimmt. Kraftstoffeinspritzanordnung nach Anspruch 2, dadurch gekennzeichnet, dass eine mechanische Krafteinheit (16, 17) mit dem Schaft (8) des Ventilelements verbunden ist, mittels der der Schaft zwischen der ersten Stellung, in der das Ventilelement die Strömungsverbindung zwischen der Kraftstoffquelle (2) und der Kraftstoffkammer (4) der Nadelventilanordnung (5) schließt und die Kraftstoffkammer (4) der Nadelventilanordnung mit einem Raum (15) verbindet, der eine Herabsetzung seines Drucks gestattet, und der zweiten Stellung verschiebbar ist, in der eine Strömungsverbindung zwischen der Kraftstoffquelle (2) und der Kraftstoffkammer (4) der Nadelventilanordnung besteht. Kraftstoffeinspritzanordnung nach Anspruch 3, dadurch gekennzeichnet, dass zwischen der ersten und der zweiten Stellung der Schaft (8) eine Zwischenstellung besitzt, in der die Kraftstoffströmungsverbindung von der Kraftstoffquelle (2) aus zu der Anordnung (6) zur Bewirkung einer Kraftwirkung hin an dem Ventil der Nadelventilanordnung verbunden ist. Kraftstoffeinspritzanordnung nach einem der vorhergehenden Ansprüche dadurch, gekennzeichnet, dass die mechanische Krafteinheit (16, 17) aus seiner Schaftanordnung (16) besteht, die durch elektrischen Strom verschiebbar ist und die mit dem Schaft (8) des Ventilelements verbunden ist. Kraftstoffeinspritzanordnung nach Anspruch 4, dadurch gekennzeichnet, dass die mechanische Krafteinheit weiter eine Federanordnung (17) oder dergleichen aufweist, die eine Kraft an dem Ventilelement ausübt und bestrebt ist, dieses in einer Richtung zu verschieben, die die Nadelventilanordnung öffnet.
Anspruch[en]
A fuel injection arrangement (1) comprising - a fuel source (2) and a fuel nozzle (3) connected thereto, which includes a fuel chamber (4) and a needle valve arrangement (5) in connection with the fuel chamber for controlling the fuel injection and an arrangement for bringing about a force effect (6) on the valve of the needle valve arrangement in the closing direction thereof, - a fuel control arrangement (7), by means of the different switching positions of which the fuel flow connection is connectable between the fuel source (2) and the fuel chamber (4) of the fuel nozzle as well as between the fuel source (2) and the arrangement for bringing about the force effect (6) whereby

the fuel control arrangement (7) comprises a mechanical force unit (16, 17) for changing its switching positions.
A fuel injection arrangement according to claim 1, characterized in that the fuel control arrangement (7) comprises a valve element, the position of the stem (8) of which defines the operational state of the injection arrangement. A fuel injection arrangement according to claim 2, characterized in that a mechanical force unit (16, 17) is joined into the stem (8) of the valve element, by which the stem is displaceable between the first position, in which the valve element closes the flow connection between the fuel source (2) and the fuel chamber (4) of the needle valve arrangement (5) and connects the fuel chamber (4) of the needle valve arrangement to a space permitting the lowering of its pressure (15), and the second position, in which there is a flow connection between the fuel source (2) and the fuel chamber (4) of the needle valve arrangement. A fuel injection arrangement according to claim 3, characterized in that between the first and the second position, the stem (8) has an intermediate position, in which the fuel flow connection is connected from the fuel source (2) to the arrangement for bringing about a force effect (6) on the valve of the needle valve arrangement. A fuel injection arrangement according to any of the preceding claims, characterized in that the mechanical force unit (16, 17) consists of a stem arrangement (16) displaceable by electric power, which has been connected to the stem (8) of the valve element. A fuel injection arrangement according to claim 4, characterized in that the mechanical force unit further comprises a spring arrangement or alike (17) subjecting a force to the valve element , which tends to displace it to a direction which opens the needle valve arrangement.
Anspruch[fr]
Ensemble d'injection de carburant (1) comprenant - une source de carburant (2) et un gicleur de carburant (3) y étant relié, incluant une chambre de carburant (4) et un dispositif de soupape à pointeau (5) en liaison avec la chambre de carburant destiné à contrôler l'injection de carburant et un dispositif destiné à entraîner un effet dynamique (6) sur la soupape du dispositif de soupape à pointeau dans le sens de l'obturation de celui-ci, - un dispositif de contrôle de carburant (7), permettant par l'intermédiaire des différentes positions de commutation de ce dispositif de raccorder le carburant entre la source de carburant (2) et la chambre de carburant (4) du gicleur de carburant ainsi qu'entre la source de carburant (2) et le dispositif destiné à entraîner l'effet dynamique (6), le dispositif de contrôle de carburant (7) comprenant une unité dynamique mécanique (16, 17) destinée à changer ses positions de commutation. Ensemble d'injection de carburant selon la revendication 1,

caractérisé par le fait que le dispositif de contrôle de carburant (7) comprend un élément de soupape, dont la position de la tige (8) définit l'état opérationnel de l'ensemble d'injection.
Ensemble d'injection de carburant selon la revendication 2,

caractérisé par le fait qu'une unité dynamique mécanique (16, 17) est reliée à la tige (8) de l'élément de soupape, par l'intermédiaire duquel la tige peut être déplacée entre la première position, dans laquelle l'élément de soupape obture le débit de carburant entre la source de carburant (2) et la chambre de carburant (4) du dispositif de soupape à pointeau (5) et raccorde la chambre de carburant (4) du dispositif de soupape à pointeau à un espace permettant la baisse de sa pression (15), et la seconde position, dans laquelle il existe un raccordement entre la source de carburant (2) et la chambre de carburant (4) du dispositif de soupape à pointeau.
Ensemble d'injection de carburant selon la revendication 3,

caractérisé par le fait que entre la première et la seconde position, la tige (8) a une position intermédiaire, dans laquelle le carburant est raccordé de la source de carburant (2) au dispositif destiné à entraîner un effet dynamique (6) sur la soupape du dispositif de soupape à pointeau.
Ensemble d'injection de carburant selon l'une quelconque des revendications précédentes,

caractérisé par le fait que l'unité dynamique mécanique (16, 17) consiste en un dispositif de tige (16) déplaçable par courant électrique, ayant été raccordé à la tige (8) de l'élément de soupape.
Ensemble d'injection de carburant selon la revendication 4,

caractérisé par le fait que l'unité dynamique mécanique comprend de plus un dispositif à ressort ou similaire (17) soumettant une force à l'élément de soupape, tendant à le déplacer dans un sens ouvrant le dispositif de soupape à pointeau.






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