HK1101605A - Injector for a fuel injection system and fuel injection system with such an injector - Google Patents

Description

The Commission has also adopted a proposal for a directive on the protection of workers from risks related to exposure to ionising radiation.

The present invention relates to the field of fuel-injected combustion engines and concerns an injector for a fuel injection system as defined in claim 1 and a fuel injection system with such an injector.

The Technical Standards

In common-rail fuel injection systems, the fuel supplied by a high-pressure pump is usually pumped into the storage volume of a common rail running along the series of injectors, from which individual branch lines to each of the individual controlled injectors are discharged. Such an arrangement with a separate common rail has several disadvantages: the separate common rail, which must be designed for high fuel pressures, requires a considerable effort in manufacturing. This is particularly true of the bolts and connections of the branches to the injectors, as well as the supply and return lines to and from the pressure pump. Each of these connections also involves a significant risk of dialysis.

It has already been proposed in EP-A1-1 469 188 that, in a dual coaxial line for common rail systems, combining high-pressure and low-pressure fuel feedbacks, the common rail system injectors should be fitted with two opposing combined high and low-pressure connections at the upper end, which can then be connected in series within the fuel injection system at the high and low-pressure side, with the connecting lines between adjacent injectors and their high-pressure line volumes forming the common rail.

The high-pressure chamber 14 is connected by a T-like narrow connecting channel 15 to the common rail between two high-pressure terminals A and A. The common rail 17 forms the common rail and its high-volume output. The common rail 14 in the injectors 11, 12 is separated from the common rail by the connecting nozzles 15 of the fluynchk 17 fluynchk, so that it does not have to be significantly altered to maintain the high-pressure output.

The following shall be considered as a single product:

The present invention is therefore intended to create a common-rail fuel injection system injector which allows for a simplification of the fuel injection system without showing the disadvantages of known solutions and to specify a fuel injection system that operates with such injectors.

The problem is solved by the combination of the features of claims 1 and 9. The injectors of the invention are characterised by the presence in the injectors housing of at least two separate high pressure connections, which provide access from the outside to the high pressure chamber and are each designed to connect a high pressure line. In the fuel injection system of the invention, the injectors are arranged in series with their high pressure connections in the high pressure line so that the high pressure line passes through the high pressure line of each injector.

The design of the injector according to the invention is characterised by the high pressure connections being located at the upper end of the high pressure chamber and the high pressure connections being located at the same height in the axial direction, which results in good accessibility and simplification in the manufacture and connection. This is particularly true if, according to further training, two high pressure connections are provided and the two high pressure connections are located opposite each other and intersect with respect to the axis.

A further simplification is achieved if the high pressure connections are of the same design and dimensions, particularly in terms of the cross-section.

The high pressure connections preferably have a thread for soluble screwing of the high pressure line, in particular the thread is formed as an inner thread.

The injector is particularly easy to use if the high pressure chamber is coaxialized to the injector axis.

The basic idea of the fuel injection system according to the invention is to use injectors with a high pressure chamber from which the fuel required for the injection is extracted, choosing the volume of the high pressure chamber so large that the sum of the volumes of the high pressure chambers of several similar injectors in a common-rail injection system is sufficient to form the storage volume required for the common rail, and to add these injectors with their high pressure chambers one after the other to the high pressure line so that the high pressure chambers together with the connecting pressure line form a common rail with the corresponding storage volume. This can be achieved in a particularly simple and efficient way by means of a fuel-saving platform on the common-rail injection system.

The fuel injection system can be used with advantage by the injector according to the invention.

A design of the fuel injection system according to the invention is characterized by a return to the high pressure pump from the last of the series injectors, which forms a kind of ring line which is advantageous for compensating for pressure fluctuations in the volume of storage formed.

The film is a comedy about a young man who is forced to live with his mother.

The present invention is explained in more detail below by means of examples of execution in connection with the drawing. Fig. 1the schematic representation of injectors with two high pressure terminals along a high pressure line according to the state of the art;Fig. 2in a representation comparable to Fig. 1 the principle of the fuel injection system according to the invention;Fig. 3in the longitudinal section a preferred example of an injector according to the invention with a large volume high pressure chamber accessed from the outside by two separate high pressure terminals; andFig. 4an introductory example of a high pressure injection system according to the invention with light in series injectors connected by pressure line connections.Fig. 2 and a high pressure pump return to the pump.

The method of application of the invention

In Fig. 2 the principle of the fuel injection system according to the invention is shown in a representation similar to Fig. 1. Of the fuel injection system 10', again only two 11' and 12' injectors out of several are shown. Each of the 11', 12' injectors has an internal high pressure chamber 14', from which the high pressure fuel is injected into the combustion chamber by the inlet valve formed by the injection nozzle 13 and nozzle needle 16. At the high pressure chamber 14', the 11', 12' injectors are arranged sideways and opposite each of two high pressure terminals A' series, with which the 11', 12' injectors are inserted into the high pressure pump line 17' in such a volume that they can be connected by the high pressure valve 14' in such a way that the total volume of the incoming high pressure air is sufficient to form a single volume.

In order to meet these requirements, a novel type of injector is proposed. Figure 3 shows in the longitudinal section a preferred example of such an injector according to the invention.

The injector 20 has, within an injector housing 18, a coaxial high pressure chamber 23 running in the longitudinal direction (along the axis 45) in which, for example, the nozzle 26 of the injector 20 is located. At the lower end of the injector housing 18, the actual injection valve 22 is screwed by means of a casing 37. At the lower end of the injector valve 22, injection holes 38 are connected to the high pressure chamber 23 and can be opened or closed with the nozzle 26. Such an arrangement of the nozzles 26 with their borehole 21 is particularly advantageous for the invention because this nozzle has a significantly thin volume of air. This is a common problem for a standard nozzle 815-51 injector, but the pressure in the nozzle 21 is not as high as in the case of the nozzle 815-51 injector.

The invention is based on the idea, as already stated above, of omitting the common rail, which forms the storage volume of the current common rail systems, and replacing it by the sum of the individual volumes of the high-pressure chambers 23 in the injectors by connecting them in a sort of serial circuit by means of simple high-pressure lines (Fig. 4).

To this end, the high pressure chamber 23 of the injector 20 must have at least two separate high pressure connections 24 and 25 (Fig. 3). These high pressure connections 24, 25 are located laterally in a radial direction away from the injector housing 18 and each terminate in the high pressure chamber 23 and thus connect the high pressure chamber 23 to the high pressure connecting lines (43 in Fig. 4) which connect the injectors 20.1, ..., 20.4 connected in series (Fig. 4). The high pressure pump 41 also has two high pressure connections and, together with the high pressure connections 42, the injectors 20.1, ..., 20.4, the high pressure connections 43 and the return line 44, forms a ring which is advantageous for the type of pressure variations in the specimen.

The high-pressure connectors 24, 25 on the injector housing 18 are preferably arranged in the axial direction at the same height. They are arranged opposite each other and curve with respect to the axis 45. In addition, they are similar in design and dimensions, especially in terms of the cross-section. For example, the high-pressure connectors 24, 25 have an inner screw (not shown in Fig. 3) which serves as a counter-screw for a (not shown) high-pressure screw to the high-pressure connection to the high-pressure line 42, 43, 44 (Fig. 4).

The injectors shown in Figure 3 have the following specifications:

At the top of the injector 20 a control mechanism 19 is shown to control the injection valve 22 schematically. The control mechanism 19 has, for example, an electromagnet 30 which, when charged with an excitation pulse fed through the connector 28, attracts an associated anchor 31 and thereby releases a control bore 32 (the electromagnet 30 itself is connected to the injector casing 18). By opening the control bore 32 the pressure in a control room 34 located below is released. A control tube 34 in the direction of the axially conductive control piston 35 and the adjacent needle 21 are slid with the pressure spring against the pressure slide 36 which is raised under the injector 22 and the pressure from the injector 22 is released into the injector room 23 and the pressure is released from the pressure spring 23 is placed around the injector room 22 and the pressure is released from the injector.

When the excitation of the electromagnet 30 is interrupted, the spring 29 pushes the anchor 31 down and the control bore 32 is closed. Fuel flows back into the control room 34 through the smaller bore 33 leading to the control room 34. The pressure difference on the control piston 35 is removed by the spring 36 pushing the needle 21 down with the nozzle needle 26 and the injection through the injection holes 38 is interrupted.

The amount of fuel flowing out during the open control bore 32 (with an excited electromagnet 30) flows up through the hollow anchor 31 through a backflow nozzle 27 through an unmarked collector tube back into the fuel tank (also unmarked).

An example of a four-cylinder fuel injection system 40 after the invention is shown in simplified form in Fig. 4. From a high-pressure fuel pump 41 a high-pressure line 42 runs to the four in-series injectors 20.1 to 20.4 connected by high-pressure connecting lines 43. From the last injector 20.1 in the series of four injectors, a re-direction 44 goes back to the high-pressure pump 41. The injectors 20.1 to 20.4 have preferably the internal structure as shown in Fig. 3 by means of the injector 20. They are inserted directly into the high-pressure lines 42, 43 and 44 with their high-pressure lines 23 and the sum of the four volumes of the high-pressure connecting lines 23 and the high-pressure line 23 is produced in a way that is not only completely understandable for the common high-pressure railway, but also for the other high-pressure railways.

The Commission shall adopt implementing acts laying down the rules for the application of this Regulation.

10,10',40 fuel injection system 11,11',12,12'Injector13Injector nozzle14,14'High pressure chamber15Connection channel16Nozzle needle17,17'High pressure line18Injector housing19Adjustment mechanism20Injector 20.1,..,20.4Injector21Injector 22Injection valve23High pressure chamber24,25High pressure connection26Injector needle27Reflux nipple28Electrical connection29Feder30Electromagnet31Anchor32Control bore33Boring (small)34Control chamber35Pulse36Lock valve 37Injector 3737High pressure pump41Final pressure pump42High pressure pump4High pressure pump4A 45A

Claims (11)

1. Injector (11', 12', 20) for a fuel injection system (10', 40), comprising an injector housing (18), extending along an axis (45) which encloses an internal high pressure chamber (14', 23) for the intake of high pressure fuel, an injection valve (13, 16, 22) at the lower end of the injector housing (18) which is connected to the high pressure chamber (14', 23) and a nozzle (13, 21, 26) in the axial direction through the high pressure chamber (14', 23) which is hydraulically operated by means of a control mechanism (19) located at the upper end of the injector housing (18) and which, after the axial position of the injector housing (13, 16, 22, 22, 23, 24, 24, 24) is closed, the injector valve (13, 16, 18, 24, 24, 24) is either closed or closed by means of two separate inlets, each of which provides access to the injector housing (14', 24, 43, 25) from at least one of the pressure chambers.
2. Injector according to claim 1, characterised by the high pressure connections (A', 24, 25) at the upper end of the high pressure chamber (14', 23).
3. Injector according to claim 1 or 2, characterised by the high-pressure terminals (A', 24, 25) being arranged in an axial direction at equal height.
4. Injector according to one of the claims 1 to 3, characterised by two high pressure connections (A', 24, 25) and by the two high pressure connections (A', 24, 25) being located opposite each other and interlacing with each other in relation to the axis.
5. Injector according to one of the claims 1 to 5 characterised by the similarity of the high pressure connections (A', 24, 25) in design and dimensions, in particular in terms of cross-section.
6. Injector according to one of claims 1 to 5 characterised by the high-pressure connections (A', 24, 25) having a thread for soluble screwing of the high-pressure line (17', 42, 43, 44).
7. Injector according to claim 6, characterised by the thread being formed as an inner thread.
8. Injector according to one of claims 1 to 7, characterised by the high pressure chamber (14', 23) being coaxialized to the axis (45) of the injector (11', 12', 20).
9. Fuel injection system (40) with a high pressure pump (41) and multiple injectors (11', 12', 20.1,..., 20.4), supplied with high pressure fuel by the high pressure pump (41) via a high pressure line (17', 42, 43) characterised by each of the injectors (11', 12', 20.1,..., 20.4) having a high pressure chamber (14', 23) from which the fuel required for injection is extracted, so that the volume of the high pressure chamber (14', 23) is chosen so that the sum of the volumes of the high pressure chambers (14', 23) of several equal injectors in a common rail injection system is sufficient to form the required storage volume for the common rail, and that the injectors (11', 121, 120, 114, 120, 141, 124, 125, 125, and 125) are injected into each other with their high pressure chambers (14', 23) and the volume of the high pressure injectors (17', 120, 124, 125, 125, and 130) is sufficient to form the required storage volume.
10. Fuel injection system according to claim 9, characterised by the use of injectors (11', 12', 20.1,..., 20.4) according to one of claims 1 to 8.
11. Fuel injection system according to claim 9 or 10, characterised by the return of a feed (44) to the high pressure pump (41) from the last of the injectors in series (11', 12' 20.1,..., 20.4).