EP2122154A1

EP2122154A1 - Fluid injection valve

Info

Publication number: EP2122154A1
Application number: EP07856422A
Authority: EP
Inventors: Andreas GRÜNDL; Bernhard Hoffmann; Friedrich MÖRTL
Original assignee: Compact Dynamics GmbH
Current assignee: Compact Dynamics GmbH
Priority date: 2007-02-23
Filing date: 2007-12-06
Publication date: 2009-11-25
Also published as: DE102007008901B4; WO2008101535A1; US8480014B2; US20100140380A1; DE102007008901A1

Abstract

The invention relates to a fluid injection valve, having an inlet which is designed to receive fluid from a supply line and which is connected to a chamber (14), having a fluid outlet (52) which is connected to the chamber and which is designed to allow fluid to flow out of the fluid injection valve and which has a valve arrangement, having a valve seat (48) and a valve element (46), wherein the valve element is designed to perform opening and closing movements relative to the valve seat, having a linear actuator which is designed to move the valve element relative to the valve seat, and having a spring arrangement (30) which exerts a force on the valve element, which force is dependent on the fluid pressure prevailing in the chamber.

Description

Fluid injection valve

description

background

Hereinafter, a fluid injection valve will be generally described, for example, for directly injecting fuel into a combustion chamber of an internal combustion engine. In principle, it is possible to use the invention both in directly injecting, and in conventional, injecting into the intake manifold engines. However, the field of application of the invention is not limited to fuel injection systems. The invention can also be used in other fields of application in which the precisely controlled and / or metered introduction of fluid into a space, an application region, or a working chamber is required or desirable.

The fluid injection valve is explained here in connection with a fuel injection into a combustion chamber of an internal combustion engine.

The steadily increasing requirements of exhaust gas legislation with further decreasing limit values results in the challenge of optimizing the formation of pollutants at the place of their formation by optimizing the injection process of fuel into the combustion chamber. In particular, CO ₂ , NO _x and soot particle emissions are critical. Through the development of injection systems with ever higher injection pressures and highly dynamic injectors, as well as through cooled exhaust gas recirculation and oxidation catalysts, it is possible to comply with current limit values. However, the potential of the previous emission reduction measures seems to have been reached.

PRIOR ART In the prior art so-called "common rail" systems are known, which are also referred to as accumulator injection systems. The pressure generation and the fuel injection are completely decoupled from each other in the common rail system. A separate high-pressure pump continuously generates pressure in the fuel supply line for all injectors of an internal combustion engine. Thus, the fuel pressure is built up independently of the injection sequence and is permanently available in the fuel line. However, pressure fluctuations occur here, which have an effect on the amount of fuel injected into the combustion chamber. The constantly high pressure of more than 1350 bar is stored in the so-called rail (= rail, line) and provided via short injection lines the fast switching solenoid valves (injectors) of a cylinder bank of the internal combustion engine. The injection timing and the fuel quantity are calculated individually for each cylinder and injected via the injectors.

The fuel pressure in the rail is conventionally adjusted by a pressure control valve and monitored by a rail pressure sensor. This represents a considerable expenditure on equipment, which makes such common rail systems very expensive.

For a "clean" combustion of fuel in internal combustion engines but also in other applications, it is important to dose the fluid, so for example, the fuel, particularly precise and also deliver variable amounts with a precise reproducibility over a variety of injection cycles. In known injection systems, however, it is very difficult to control the accuracy of the metering with the dynamics required, for example, for a high-speed combustion engine.

In particular, in the case of inwardly opening valves, the following problems also occur: When the valve is closed, due to the high pressure in the valve housing (2000 to 2500 bar and more), very high closing or holding forces act on the valve member seated on the valve seat. These forces are determined from the product of the pressure in the valve housing multiplied by the valve cross-section. These forces must be overcome by a controlled actuator when opening the valve. Therefore, the (for example electromagnetically or piezoelectrically operating) actuator must be designed according to high performance. Thus, conventional electromagnet or piezo actuators build relatively large and require high electrical power. In addition, the operating electronic control and the control lines are to be dimensioned accordingly (electrical and mechanical).

There have been studies (by FIAT) of a fuel injector fluid injector having a piston coupled to the valve member that generates a force opposite to the closing force. The piston is dimensioned so that it relieves the valve member depending on the pressure in the interior of the valve housing so that it is charged at any time with the approximately same low closing force. The piston releases a pressureless fuel return to the fuel tank when opening the valve. This piston and a bushing surrounding it must be very precisely be taken; In addition, they are subject to significant wear over the life of the fluid injector. The pressure-free return of the fuel required here represents a considerable expense in terms of space requirements and production.

Underlying problem

This results in the problem of at least partially overcoming the disadvantages of the known systems mentioned above.

solution

To solve this problem, a fluid injection valve has the features of claim 1. Such a fluid injection valve has an inlet adapted to receive fluid from a supply line and connected to a chamber, a fluid outlet, which is connected to the chamber and which is adapted to allow fluid to flow out of the fluid injection valve, and a valve assembly having a valve seat and a valve member, wherein the valve member is adapted to open and close relative to the valve seat opening and closing movements a linear actuator adapted to move the valve member relative to the valve seat, and having a spring arrangement which exerts on the valve member a force which is dependent on the pressure prevailing in the chamber fluid pressure.

This arrangement is capable of at least partially compensating for uncontrolled pressure fluctuations in the fluid supply, that is, for example, pulsations of a feed pump feeding the fluid injection valve. This makes it possible to improve the metering behavior of the fluid injection valve. In the case of fuel injection systems in internal combustion engines, this contributes to a reduction of the fuel consumption, to a reduction of the exhaust gases (CO ₂ , NO _x , soot particles, etc.). The invention advantageously takes advantage of the fact that the inventive fluid injection valve, in which a spring arrangement exerts a force on the valve member which depends on the fluid pressure prevailing in the chamber, not only the opening time and the opening stroke of the valve member is better to control relative to the valve seat, but also the speed of the opening stroke. This is due to the fact that the pressure fluctuations of the supplied fluid are at least partially eliminated, so that their influence on the valve member is eliminated. This makes it possible to control the valve actuation more precisely than is already the case with known arrangements. The associated savings Fuel - and consequently also the reduction of exhaust gases - can amount to a few percent.

This considerable saving also results from the fact that the actuators of known injectors must be designed to compensate for these pressure fluctuations; that is, they must apply the necessary closing and actuating forces even in unfavorable fluid pressure conditions in the chamber of the fluid injection valve. Now, if these pressure fluctuations are at least partially balanced, can - with the same size and same performance data - a more dynamic operation of the fluid injection valve done, or vice versa, smaller fluid injectors can be provided with comparable performance data. In addition, the movement of the valve member relative to the valve seat can be better controlled so that, for example, a considerably "softer landing" of the valve member in the valve seat than in previous arrangements is made possible The geometry of the valve allows the geometry of the optimum injection behavior of the fuel into the combustion chamber to be increased.The larger the valve seat diameter (because of the lower material load on the valve seat in the closed state) the valve member can move to the valve seat Thus, the injection time can be significantly reduced - with the same fluid volume flow - thus very efficient multiple injections per stroke are possible, the background being that the locking force with linearly increasing valve seat diameter quadratisc h increases while the valve member stroke linearly decreases at the same fluid volume flow. Consequently, the material stress at the sealing point increases linearly, with the result that the material load at the sealing point is the limiting factor.

Further developments and refinements

In one embodiment, the spring assembly is configured and dimensioned to exert a force inversely proportional to the fluid pressure prevailing in the chamber on the valve member. Thus, in a compression spring configuration, a high force on the valve member is imposed by a small force on the valve member at high fluid pressure prevailing in the chamber and a high force on the valve member when the fluid pressure in the chamber is low. In a tension spring configuration, the arrangement should be such that a high force acts on the valve member with low fluid pressure prevailing in the chamber and low force acts on the valve member with high fluid pressure prevailing in the chamber. In the fluid injection valve, the spring arrangement can exert a force acting on the valve member in the direction of closing the valve arrangement, provided that the valve member on opening relative to the chamber moves outwardly, or on the valve member in the direction of opening the valve assembly acts, provided that the valve member 5 moves inwardly when opening - relative to the chamber. This reduces the force to be applied by the linear actuator in order to keep the fluid injection valve closed in the case of an outward-opening variant or to open it in the case of an inward-opening variant.

In one embodiment, the spring assembly has a rest condition with a bias, wherein the biasing exerts about one quarter to three quarters of the force (preferably about half) on the valve member that exerts the fluid pumped into the chamber.

As an embodiment, the spring arrangement is formed by a bellows arrangement whose force exerted on the valve member varies with the pressure of the fluid prevailing in the chamber. The shape of the bellows, which is preferably made of austenitic stainless steel, is chosen so that they in addition to the caused by the fluid pressure volume change as (biased)

20 tension or compression spring between the immovable housing of the fluid injection valve and the relatively movable valve member acts.

For this purpose, the bellows arrangement may have a substantially (circular) cylindrical or even (double) conical shape, wherein the spring arrangement is either designed and dimensioned such that it elongates with increasing fluid pressure, or that it rises as the pressure increases Fluid pressure shortens.

The spring assembly may also have a substantially plate-shaped push / pull plate, which is in the radial direction - based on the direction of movement of the valve-o limb - oriented, and at least one deformable under pressure chamber, the plate-shaped Seh ub- / train plate fluid-tight is arranged so that it elastically deformed under the action of pressure prevailing in the chamber, the push / pull plate, so that their force exerted on the valve member with the force prevailing in the chamber pressure of the fluid varies. 5

The spring assembly may have a circular-cylindrical or circular-conical ring portion which rests on the stator, and a flat disc portion, the one can have a central recess in which a pin of the armature / rotor is added.

On the side facing the stator of the spring arrangement, a concentrically corrugated sheet metal part can be arranged fluid-tight so that a pressure-deformable pressure chamber is formed by the sheet metal part and the push / pull plate.

The concentric corrugated sheet metal part may be fluid-tightly connected at its edges with the push / pull plate or the ring portion and at several points where the corrugated sheet metal part is in contact with the push / pull plate, fixed connections between them are provided.

The linear actuator can have several configurations, for example that of a piezoactuator; in the present case, however, it is an electromagnet arrangement with a stator and a rotor. The rotor may be coupled to the valve member or be part of the valve member. Alternatively, the valve member may also be an integral part of the rotor. On the runner, the bellows arrangement may be articulated.

In this case, the stator can be formed as a multipole stator with a plurality of adjacently spaced stator poles, which has a plurality of exciting coils associated with the respective stator poles and arranged between each two stator poles. Multipole stands in the sense of the present invention are understood to mean an arrangement of two or more cross-sectionally cylindrical (for example round or oval) or polygonal (for example triangular, quadrangular or hexagonal) pole webs which are disposed on a surface, e.g. a level are arranged and are surrounded by one or more coil arrangements. In this case, each Polsteg be associated with its own coil arrangement, or a coil arrangement is wound around several Polstege. This allows the generation of a high magnetic force density, which manifests itself in a magnetic field which builds up and dissipates very rapidly and in a valve switching behavior with high dynamics.

Similarly, the armature can be designed as a multipole anchor whose anchor poles are aligned with the respective stator poles. The anchor poles may be formed by weakening or thickening of the anchor plate, which otherwise follows substantially the contour of the end face of the totality of all pole webs. The electromagnet arrangement can have a working air gap oriented preferably transversely to the direction of movement of the armature between the upright and the armature. Depending on the spatial conditions, however, it is also possible to orient the working air gap differently.

In one embodiment of the invention, the stand and / or the armature of the linear actuator are arranged in the interior of the chamber.

In order to allow the flow of the fuel to be as unimpeded as possible, the stator and / or the armature have at least one fluid channel for fluid in the direction of the valve arrangement.

In order to realize particularly slender or elongated designs with large holding or closing forces, a cascading of several electromagnet arrangements acting on the valve arrangement can take place. In this case, the electromagnet arrangements acting on the valve arrangements can be oriented either in the same direction or in opposite directions.

In one embodiment, the linear actuator is provided for the valve means which acts on a movable valve member to move it between an open position and a closed position relative to a stationary valve seat cooperating with the valve member and located downstream of the fluid inlet , Thus, a direct switching valve arrangement can be realized.

The fluid injection valve can be configured, set up and dimensioned as a fuel injection valve arrangement in order to protrude into the combustion chamber of a foreign-fired internal combustion engine or into the combustion chamber of a self-igniting internal combustion engine.

Further advantages, embodiments or possible variations will become apparent from the following description of the figures in which the invention is explained in detail. Brief description of the figures

Hg. Fig. Ia shows a schematic representation in longitudinal section through a fluid injection valve according to an embodiment in the closed position.

FIG. 1b shows the fluid injection valve according to FIG. 1a in the open position.

In FIGS. 2a, 2b a bellows / spring arrangement is shown schematically in longitudinal section according to a first embodiment.

In FIGS. 3a, 3b a bellows / spring arrangement is shown schematically in longitudinal section according to a second embodiment.

A further embodiment of a fluid injection valve is shown schematically in longitudinal section in closed (FIG. 4a) / open (FIG. 4b) valve position in FIGS. 4a, 4b. In Fig. 4c is a schematic perspective view of the spring element from a bottom view.

Detailed Description of Presently Preferred Embodiments

In FIG. 1 a, a fluid injection valve with a substantially rotationally symmetrical housing 10 to a central longitudinal axis M is shown in a schematic longitudinal section in a closed position, while in FIG. 1 b such a fluid injection valve is shown in an open position. Such a fluid injection valve can serve to inject fluid in the form of fuel directly into the combustion chamber, not further illustrated, of an internal combustion engine. The fluid injector 10 has (at the top of FIG. 1) a central fluid inlet 12 through which fluid from a fluid distribution conduit (not shown) may flow to a chamber of the fluid injector 10.

The chamber 14 of the fluid injection valve 10 has a substantially circular cross-sectional shape and is in the inlet near area by a transverse plate 18 with perforations 20 stiffened. At a distance from the transverse plate 18, the inlet remote, an electromagnet assembly 22 is arranged. The electromagnet assembly 22 has arranged inside the chamber 14, made of soft iron (plates) shaped stand 24 with a substantially circular cylindrical cross section and a likewise arranged in the interior of the chamber 14, substantially circular cylindrical disc-shaped armature as a rotor 26. Der Anchor / rotor 26 is at its one (in Fig. 1 upper) end face 26 a via a pin with an end of a metallic bellows implemented spring assembly 30 rigidly connected. The bellows / spring assembly 30 is secured to the transverse plate 18 at its opposite (upper in FIG. 1) end by means of a cross pin. In this case, the stand 24 is designed as a multipole stand with elongate, side by side or concentric, arranged at a distance stator poles 24a. Several excitation coils 24b are associated in the stator 24 surrounding the respective stator poles 24a. Similarly, the disc-shaped armature 26 may be formed as a multipolar anchor, the anchor poles are aligned with the respective stator poles. Thus, the armature 26 can move along the central longitudinal axis M, wherein the metallic bellows 30 is adapted to expand / contract along this central longitudinal axis M.

The armature / rotor 26 is rigidly connected at its other (in Fig. 1 lower) end face 26 b with a valve needle 34. The valve needle 34 extends through a central opening 36 in the stator 24 and carries at its free end (in Fig. 1 below) a valve member 46 which is longitudinally movable along the central axis M. The valve member 46 is part of a valve assembly 46, 68 consisting of the valve member 46 and a valve seat 48 to eject the fluid in a controlled manner. The valve seat widens conically in the flow direction; Accordingly, the valve member 46 is shaped and cooperates with the valve seat 48. The valve member 46 is moved by the valve needle 34 opposite the stationary valve seat 48 cooperating with the valve member 46 and located downstream of the fluid inlet 12 between an open position and a closed position (up and down in FIG. 1). The valve seat is for this purpose incorporated in a sleeve 36 which closes a pipe socket 50 which is integrally formed on the chamber 14.

The armature disk 26 is loaded with the valve needle 34 through the bellows / spring arrangement 30 arranged coaxially with respect to the center axis M, so that the valve member 46 located at the end of the valve needle 34 is seated in the valve seat 48 in a fluid-tight manner, ie is forced into its closed position. When energizing the excitation coils 24b, a low-eddy magnetic field is induced in the stator poles 24a, which pulls the armature disk 26 with the valve needle 34 in the direction of the stator 24. Thus, the valve member 46 moves away from the valve seat 48 in its open position. In this way, fluid coming from the fluid inlet 12 is discharged from the fluid injection valve 10 in a controlled manner through the valve member 46 or the valve seat 48, for example, into the combustion chamber of an internal combustion engine. It can either be act the combustion chamber of a spark-ignition internal combustion engine or the combustion chamber of a self-igniting internal combustion engine.

Between the stator 24 and the armature 26, a transverse to the direction of movement of the armature 26 oriented working air gap 32 is formed. In this case, the difference between the minimum and the maximum extent of the working air gap in the direction of the central longitudinal axis M represents the stroke by which the valve member 46 can lift off the valve seat 48.

The Multipolständer 24 has an array of a plurality of cross-sectional or plan view cylindrical, polygonal pole pieces 28 a which are arranged on a surface. These in the present example rectangular pole webs may be formed in the plan view also substantially square or trapezoidal. They are surrounded by one or more coil arrangements 24b. In the present embodiment of the invention, each pole web is assigned its own coil arrangement which surrounds it. However, it is also possible that a coil arrangement is wound around a plurality of pole webs. However, it should be understood that the coil assemblies can share the space between two adjacent pole lands.

The Multipolständer 24 may be formed of one-piece soft iron, from which the pole web or the interstices are formed. In such a one-piece soft iron molding recesses in the form of slots, in plan view longitudinal grooves, or slots may be incorporated. But it is also possible to produce the Magnetjochanordnung as a molded part made of sintered iron powder or to assemble from a variety of sheet metal layers or from several sections and to glue if necessary.

The armature 26 is a circular soft iron-containing disc having a shape described in detail below. The multipole stator 24 and the armature 26 overlap in the radial direction with respect to the center axis M. As shown in Fig. 1, the multipole stator 24 has approximately the same outer diameter as the armature 26, so that the magnetic flux caused by the coil assemblies 24b can penetrate into the armature 26 practically without appreciable stray losses. This realizes a particularly efficient magnetic circuit that allows very low valve opening / closing times and high holding forces. Regardless of the design of the multipole stator 24 or of the coil arrangements 24b, the armature disk 26 can also be a closed disk made of soft iron, provided that the configuration of the magnetic yoke or magnet coil arrangement ensures that the leakage losses or eddy current losses are low enough for the respective one Are intended purpose. To reduce the weight at optimized magnetic flux density, the armature is designed as a multipole anchor whose anchor poles are aligned with the respective stator poles out. For this purpose, the anchor poles are formed by weakening or thickening of the otherwise substantially the contour of the end face of the totality of all pole webs following anchor plate.

The stator 24 is surrounded by an annular gap 44 through which fluid located in the chamber 16 can pass through the pipe socket 50 to the valve arrangement 46, 48. The sleeve 36 has a central fluid outlet 52 which opens into the valve seat 48 and through which the valve needle 34 projects with the valve member 46.

The valve needle 34 has at its free end an annular collar 38, which serves together with the inside of the nozzle 50 surface of the sleeve 36 as a stop and stroke limitation for the valve assembly 46, 48.

While the embodiment described above represents an outwardly opening valve, it is also possible to realize an inwardly opening variant of the valve arrangement 46, 48. In order to compensate for the force produced by the pressurized fluid, as in the outward-opening embodiment, which forces the valve assembly 46, 48 in the sense of closing, it is particularly advantageous to use the bellows-type (circular) cylindrical bellows. Spring assembly 30 to be mounted in the resting state with a bias that is about to set to about half of the force that exerts the pumped into the chamber fluid as (closing) force on the valve member. For this purpose, the transverse plate 18 can by means of a screw which is rotated in a screw sleeve 60 of the transverse plate 18 facing the fluid inlet 12, the axial elongation or the force of the bellows / spring arrangement 30 acting on the armature 26 and thus on the valve member 46 be adjusted. In this axial position then the transverse plate 18 is to be welded in the chamber 14 at 62, for example by means of a laser.

The configuration of the bellows / spring assembly 30 also depends on whether an arrangement is chosen that is designed and dimensioned to elongate with increasing fluid pressure or to shorten as the fluid pressure increases, and thereby on the armature 26 and consequently on the valve member 46, a force correlated to the fluid pressure exerts.

In Fig. 2a is a bellows / spring assembly 30 is shown schematically, which shortens with respect to a pressure level P in the interior and outside of the Faltenbalganordnung 30 increased fluid pressure P ++ - see Fig. 2b.

In contrast, in Fig. 3a, a bellows / spring assembly 30 is shown schematically extending at a relation to a pressure level P in the interior and outside of the Faltenbalganordnung 30 increased fluid pressure P ++ - see Fig. 3b.

FIG. 4 a shows a fluid injection valve with a housing 10 essentially rotationally symmetrical with respect to a central longitudinal axis M in a schematic longitudinal section in a closed position, while FIG. 4 b shows such a fluid injection valve in an open position. The fluid injection valve 10 has (in FIGS. 4a, 4b above) a central fluid inlet 12, through which fluid from a (not further illustrated) fluid distribution line can flow to a chamber of the fluid injection valve 10.

The chamber 14 of the fluid injection valve 10 has a cross-sectionally substantially circular cylindrical shape. The fluid inlet 12 remote from an electromagnet arrangement 22 is arranged. The electromagnet assembly 22 has arranged inside the chamber 14, made of soft iron (plates) shaped stand 24 with a substantially circular cylindrical cross section and a likewise arranged in the interior of the chamber 14, substantially circular cylindrical disc-shaped armature as a rotor 26. Der Anchor / rotor 26 has on its one (in Fig. 4 upper) end face 26a a pin 26b integrally formed, which has a radially widened annular collar 26c.

On the stand 24, the spring assembly 30 is supported and acts against the annular collar 26c on the pin 26a of the armature / rotor 26, which is rigidly connected at its other (in Fig. 4 lower) end face 26b with a valve needle 34.

The spring assembly 30 has in this embodiment, a circular cylindrical or circular conical ring portion 30 a, which rests with its free edge on the stand 24. On the side remote from the stand 24, the spring arrangement 30 merges via an inwardly curved wall section 30b into a flat disk section 30c. This disk section 30c has a central recess 30d and forms a substantially plate-shaped push / pull plate 30c, which is substantially radially - with respect to the direction of movement of the pin 26a of the armature / rotor 26 and the valve needle 34 with the valve member 46 - oriented. In the central recess 3Od, the pin 26a of the armature / rotor 26 is received and the push / pull plate 30c abuts against the annular collar 26c of the pin 26a.

On the side of the spring arrangement 30 facing the stand 24, a concentrically corrugated sheet metal part 3Oe is arranged in a fluid-tight manner such that a pressure-deformable pressure chamber 30F is formed by the sheet metal part 3Oe and the push / pull plate 30c. Here, the concentrically corrugated sheet metal part 3Oe is fluid-tight welded at its edges with the push / pull plate 30c and the ring portion 30a, for example. In addition, at several points 30g, where the corrugated sheet metal part 3Oe is in contact with the push / pull plate 30c, fixed connections, for example welds, are provided between them. This has the effect that, under the influence of fluid pressure prevailing in the chamber 14, the push / pull plate 30c is elastically deformed such that the pressure on the valve member 46 (via the annular collar 26c, the pin 26a of the armature / rotor 26 and the valve needle 34) applied force varies with the pressure prevailing in the chamber 14 of the fluid. As the fluid pressure in the chamber 14 increases, this force acts on the valve needle 34 in such a way that it tends to lift the valve member 46 out of the valve seat 48. The stroke, in which the push / pull plate 30c acts on the valve needle 34, is only part of the total stroke of the valve needle 34 and is so large that the resulting from the fluid pressure inside the chamber 14 closing force is eliminated when the valve member 46 from the valve seat 48 is lifted out.

In the present example, the corrugated sheet metal part 3Oe has two annular shafts. However, it can also be more or less. The annular waves, together with the push / pull plate 30c, form the pressure chamber 30f. Instead of making the pressure chamber 30f as a circular structure, it is also possible to disperse a plurality of separate chambers over the surface of the push / pull plate 30c.

The spring assembly 30 with the ring portion 30a, the inwardly curved wall portion 30b and the flat disc portion 30c is made of a bendable, tensile material as a pressed part. Also the concentric corrugated sheet metal part 3Oe is a pressed part. In this case, the stand 24 is designed as a multipole stand with elongated, side by side or concentric, spaced stator poles 24a. Several excitation coils 24b are associated in the stator 24 surrounding the respective stator poles 24a. Similarly, the disk-shaped armature 26 may be formed as a multi-pole anchor whose anchor poles are aligned with the respective stator poles. Thus, the armature 26 can move along the central longitudinal axis M, wherein the metallic bellows 30 is adapted to expand / contract along this central longitudinal axis M. The valve needle 34 extends through a central opening 36 in the stator 24 and carries at its free end (in Fig. 4 below), a valve member 46 which is longitudinally movable along the central axis M.

The valve member 46 is part of a valve assembly 46, 48 consisting of the valve member 46 and a valve seat 48 to eject the fluid in a controlled manner. The valve seat 48 is configured as an inwardly-opening valve in which the valve member 46 dips into a trough 48a having a plurality of exit passages 52 to close and exit the valve, respectively, to release the exit passages 52. The valve member 46 is moved by the valve needle 34 opposite the stationary valve seat 48 cooperating with the valve member 46 and located downstream of the fluid inlet 12 between an open position and a closed position (up and down in FIG. 4). The valve seat 48 is for this purpose incorporated in a bushing 36 which closes a pipe socket 50 which is integrally formed on the chamber 14.

In this case, the valve needle 34 is loaded with the valve member 46 by spring arrangement 30 in the sense of opening when the fluid pressure in the interior of the chamber 14 rises. When energizing the excitation coils 24 b, a vortex-current-poor magnetic field is induced in the stator poles 24 a, which pulls the armature disk 26 with the valve needle 34 in the direction of the stator 24. By spring assembly 30 for the lifting of the valve member 46 from the valve seat 48 required magnetic force - and thus the required electrical current - even with increasing or fluctuating fluid pressure in the interior of the chamber 14 are kept at least almost constant.

Between the stator 24 and the armature 26, a transverse to the direction of movement of the armature 26 oriented working air gap 32 is formed. In this case, the difference between the minimum and the maximum extent of the working air gap in the direction of the central longitudinal axis M represents the stroke by which the valve member 46 can lift off the valve seat 48. The Multipolständer 24 has an array of a plurality of cross-sectional or plan view cylindrical, polygonal pole pieces 28 a which are arranged on a surface. These in the present example rectangular pole webs may be formed in the plan view also substantially square or trapezoidal. They are surrounded by one or more coil arrangements 24b. In the present embodiment of the invention, each pole web is assigned its own coil arrangement which surrounds it. However, it is also possible that a coil arrangement is wound around a plurality of pole webs. However, it should be understood that the coil assemblies can share the space between two adjacent pole lands.

The Multipolständer 24 may be formed of one-piece soft iron, from which the pole web or the interstices are formed. In such a one-piece soft iron molding recesses in the form of slots, in plan view longitudinal grooves, or slots may be incorporated. However, it is also possible borrowed to produce the Magnetjochanordnung as a molded part made of sintered iron powder or to assemble from a variety of sheet metal layers or from several sections and to glue if necessary.

The armature 26 is a circular soft iron-containing disc having a shape described in detail below. The multipole stator 24 and the armature 26 overlap in the radial direction with respect to the center axis M. As shown in Fig. 1, the multipole stator 24 has approximately the same outer diameter as the armature 26, so that the magnetic flux caused by the coil assemblies 24b can penetrate into the armature 26 practically without appreciable stray losses. This realizes a particularly efficient magnetic circuit that allows very low valve opening / closing times and high holding forces.

Regardless of the design of the multipole stator 24 or the coil arrangements 24b, the armature disk 26 can also be a closed circular disk made of soft iron, provided that the design of the magnet yoke or magnet coil arrangement ensures that the leakage losses or eddy current losses are low enough are the respective purpose. To reduce the weight at optimized magnetic flux density, the armature is designed as a multipole anchor whose anchor poles are aligned with the respective stator poles out. For this purpose, the anchor poles are formed by weakening or thickening of the otherwise substantially the contour of the end face of the totality of all pole webs following anchor plate. The stator 24 is surrounded by an annular gap 44 through which fluid in the chamber 14 can pass through the pipe socket 50 to the valve arrangement 46, 48. In the free end (in Fig. 4 below), a sleeve 36 with the valve assembly 46, 48 is arranged. The bushing 36 has a plurality of fluid outlets 52 which extend outwardly from the valve seat 48 and which are to be closed / released by the valve member 46 disposed on the valve needle 34.

While the embodiment of FIG. 4 illustrates an inwardly opening valve, it is also possible to realize an outwardly opening variant of the valve arrangement 46, 48. In order to compensate, as in the inwardly opening embodiment, the force caused by the pressurized fluid, which forces the valve assembly 46, 48 to open, the spring assembly 30 may be mounted at rest with a preload that is approximately at approximately zero half of the force exerted by the fluid pumped into the chamber as a (visual leave) force on the valve member.

The design of the spring assembly 30 is also dependent on whether an arrangement is chosen that is designed and dimensioned so that it lengthens with increasing fluid pressure or shortened with increasing fluid pressure, and thereby on the armature 26 and thus on the valve member 46 a to force correlated to the fluid pressure exerts.

The embodiments explained in the above description of the invention and their individual aspects are of course combinable with each other, even if such combinations are not explained in detail above. The shown spatial and constructive details and relationships of the individual components to one another can be adapted to actual requirements. Incidentally, individual dimensions and proportions in the figures are selected such that the explained principles and concepts can be better represented. In the case of concrete designs, deviating dimensions may be chosen without deviating from what has been disclosed and defined in the claims.

Claims

claims

1. A fluid injection valve (10) with

an inlet (12) which

5 o is adapted to receive fluid from a supply line, and o is connected to a chamber (14),

a fluid outlet (52) connected to the chamber (14) and adapted to discharge fluid from the fluid injection valve (10) and a valve assembly (46, 48) having, with

^■ a valve seat (48) and

^■ a valve member (46), wherein the valve member (46) is arranged relative to the valve member (46)

Valve seat (48) to perform opening and closing movements,

a linear actuator adapted to move the valve member (46) relative to the valve seat (48), and with

20 - a spring arrangement (30) which exerts on the valve member (46) a force which is dependent on the pressure prevailing in the chamber (14) fluid pressure.

2. The fluid injection valve (10) according to claim 1, wherein the spring assembly (30) exerts a proportional to the prevailing in the chamber (14) fluid pressure 5 proportional force on the valve member (46).

3. The fluid injection valve (10) according to claim 1 or 2, wherein the spring assembly (30) exerts a force which a. acting on the valve member (46) in the direction of closing the Ventilanord- voltage (46, 48), provided that the valve member (46) when opening - relative to the chamber (14) - moves outward, or b. on the valve member (46) in the direction of opening the valve assembly (46, 48) acts, provided that the valve member (46) during opening - relative to the chamber (14) - moves inwards. 5

4. The fluid injection valve (10) according to one of the preceding claims, wherein the spring arrangement (30) has a rest state with a bias, wherein the biasing force exerts about a quarter to three quarters of the force on the valve member (46) exerting the fluid pumped into the chamber (14).

5 5. The fluid injection valve (10) according to any one of the preceding claims, wherein the spring assembly is formed by a bellows arrangement (30) whose force exerted on the valve member (46) with the pressure prevailing in the chamber (14) Fluids varies.

The fluid injection valve (10) according to the preceding claim, wherein the bellows assembly (30) has a substantially cylindrical or conical shape.

7. The fluid injection valve (10) according to any one of the preceding claims, i5 wherein the spring assembly (30) is designed and dimensioned so that it elongates with increasing fluid pressure.

8. The fluid injection valve (10) according to any one of the preceding claims, wherein the spring assembly (30) is designed and dimensioned so that they

20 shortens with increasing fluid pressure.

9. The fluid injection valve (10) according to claim 5, wherein the spring arrangement a. a substantially plate-shaped push / pull plate (12) radially oriented with respect to the direction of movement of the valve member (46), and b. at least one pressure deformable chamber (12) fluidly sealed to the plate-shaped push / pull plate (12) so as to elastically deform the push / pull plate (12) under the pressure prevailing in the chamber (14) on the valve member (46) 0 exerted force with the in the chamber (14) prevailing pressure of

Fluids varies.

10. The fluid injection valve (10) according to any one of the preceding claims, wherein the spring assembly (30) has a circular cylindrical or kreiskoni- see 5 see ring portion (30 a) resting on the stand (24), and a flat disc portion (30 c) has a central recess (3Od), in which a pin (26a) of the armature / rotor (26) is received.

11. The fluid injection valve (10) according to the preceding claim, wherein 5 on the stator (24) facing side of the spring assembly (30) a concentrically corrugated sheet metal part (3Oe) is fluid-tight so arranged that through the sheet metal part (3Oe) and the push / pull plate (30c) is a pressure deformable pressure chamber (3Of) is formed. O

12. The fluid injection valve (10) according to the preceding claim, wherein the concentric corrugated sheet metal part (3Oe) at its edges fluid-tight with the push / pull plate (30c) and the ring portion (30a) is connected and at several points (30g ), where the corrugated sheet metal part (30e) is in contact with the push / pull plate (30c), fixed connections are provided between them.

13. The fluid injection valve (10) according to any one of the preceding claims, wherein the linear actuator is a solenoid assembly (24, 26) having a stator (24) and a rotor (26) whose rotor (26) member with the valve-o (46) is ganged or part of the valve member (46).

14. The fluid injection valve (10) according to the preceding claim, wherein the stator is a Multipolständer (24) having a plurality of juxtaposed spaced stator poles, the multiple, the respective 5-legged stator poles (24a) associated and between each two stator poles arranged excitation coils (24b) has.

15. The fluid injection valve (10) according to the two preceding claims, wherein the armature (26) is designed as a multipole anchor whose armature poles are aligned with the respective stator poles (24a).

16. The fluid injection valve (10) according to any one of the preceding claims, wherein the electromagnet arrangement between the stator (28) and the armature (30) has a preferably transverse to the direction of movement of the armature (30) oriented working air gap (34).

17. The fluid injection valve (10) according to any one of the preceding claims, wherein the linear actuator is at least partially disposed in the interior of the chamber (16).

18. The fluid injection valve of claim 1, wherein the stator and / or the armature have at least one fluid channel for fluid in the direction of the valve arrangement. towards.

19. The fluid injector (10) of any one of the preceding claims, wherein the solenoid assembly (24, 26) acts on a moveable valve member (46) of the valve assembly (46, 48) to engage with the valve member (46). co-operating stationary valve seat (48) disposed downstream of the fluid inlet (12) between an open position and a closed position.

20. The fluid injection valve (10) according to any one of the preceding claims, wherein a plurality of the valve assembly (46, 48) acting electromagnet assemblies (28, 30, 32) are provided.

20

21. The fluid injection valve (10) according to any one of the preceding claims, which is designed and dimensioned as a fuel injection valve to protrude into the combustion chamber of a spark-ignited or a self-igniting internal combustion engine.

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