What is river degradation



description

State of the art



The invention is based on known fuel injectors for injecting a fuel into a combustion chamber of an internal combustion engine. In particular, it can be the combustion chamber of a compression-ignition internal combustion engine. Such fuel injectors are generally based on an injection valve member which opens or closes one or more injection openings. The movement of this injection valve member is mostly controlled via one or more hydraulic valves. The hydraulic valves in turn can be controlled directly or indirectly via one or more actuators. The present invention is based in particular on fuel injectors which use a magnetic actuator as an actuator. Such fuel injectors are also referred to below as magnetic injectors. In the case of magnetic injectors, the hydraulic valve is usually opened by the build-up of force when a magnetic circuit of the at least one magnetic actuator is energized. In contrast, the hydraulic valve is usually closed passively via at least one spring element.


There are basically two principles for solenoid valves. On the one hand, non-pressure compensated valves are known in which the hydraulic valve is subjected to hydraulic pressure in one direction, usually in an opening direction. One advantage of such non-pressure compensated valves is, for example, an overpressure limitation. These hydraulic valves open automatically from a defined pressure. This is a built-in safety feature for the injection system. Furthermore, good particle robustness, in particular with a spherical valve seat of the hydraulic valve, should be mentioned as an advantage of the non-pressure compensated valves. A disadvantage of non-pressure balanced valves, however, is that high rail pressures, i.e. high pressures of the fuel provided, require high spring forces from the closing spring, since the spring force results from the product of the rail pressure and the valve seat area. So that the valve can be opened even with a low rail pressure, large magnetic forces of the magnetic actuator are required. This leads to larger, heavier and therefore slower valves.


The second principle is the pressure-balanced solenoid valves. In the case of such pressure-balanced solenoid valves, overall no hydraulic pressure acts on an actuator of the hydraulic valve, since the hydraulic surfaces of the hydraulic valve cancel each other out. One advantage of such pressure-balanced solenoid valves is that there is less need for closing spring force. Furthermore, there is less need for magnetic force to counteract the closing spring. In addition, a larger released flow area is possible with the same stroke of the hydraulic valve. Pressure-compensated solenoid valves, however, generally do not have an overpressure limiting function. In addition, pressure-balanced solenoid valves are usually sensitive to particles and are less robust with regard to disruptive forces, for example friction from linings or similar disruptive forces.


An ideal hydraulic valve for use in a fuel injector should therefore on the one hand have the robustness against particles of a ball valve, have the overpressure limiting function of a non-pressure compensated valve and still be small and light and thus have short switching times.

Disclosure of the invention



A hydraulic valve for use in a fuel injector and a fuel injector which comprises at least one such hydraulic valve are therefore proposed. The fuel injector is used to inject a fuel into a combustion chamber of an internal combustion engine, in particular a self-igniting internal combustion engine. In particular, the fuel can be injected from a high-pressure accumulator, which is also referred to below as “rail” or “common rail”, for example at a pressure of at least 2000 bar.


The fuel injector has at least one injection valve member which releases or closes an injection opening, that is to say an injection valve member which, depending on its position, releases or closes the at least one injection opening. The injection valve member can be controlled by at least one hydraulic valve according to the invention. For example, this can be done in that at least one hydraulic control chamber is provided, which is hydraulically connected to the injection valve member, a pressure in the at least one control chamber being controllable by the hydraulic valve, for example optionally adjustable to high pressure (for example rail pressure) or to low pressure is. In this regard, reference can be made, for example, to known fuel injectors.


The hydraulic valve has at least one actuator. This at least one actuator can for example comprise an actuator rod. The at least one actuator can further include, for example, at least one ball and / or different types of actuators. The actuator can directly or indirectly open or close one or more openings of the hydraulic valve. The hydraulic valve can in particular be designed entirely or partially as a ball valve and / or comprise such a ball valve. However, other types of valves and / or configurations of a valve member or valve seat are also possible in principle.


The hydraulic valve also has at least one first magnetic actuator and at least one second magnetic actuator. A magnetic actuator is generally to be understood as an actuator which, by using magnetic or electromagnetic actuator principles, can directly or indirectly exert one or more forces on the actuator. In particular, as will be explained in more detail below, the magnetic actuators can comprise one or more magnetic coils and one or more armatures. The first magnetic actuator and the second magnetic actuator are set up to act on the actuator with opposing force directions. This means that each of the magnetic actuators exerts at least one force on the actuator, these forces each having at least one force component opposite to the other force. In particular, the forces can be directed completely opposite one another. In particular, the first magnetic actuator can exert an opening force, that is to say a force in an opening direction, on the actuator and the second magnetic actuator can exert a closing force, that is to say a force in a closing direction, or vice versa. For example, if the actuator is designed entirely or partially as an actuator rod, the first magnetic actuator can, for example, exert a force parallel to or with at least one component parallel to this actuator rod in a first direction, and the second magnetic actuator can exert a force parallel to the actuator rod or with at least one component parallel to the actuator rod in the opposite direction. For example, these can be axial forces with respect to an axis of the fuel injector.


The hydraulic valve can also have at least one spring element, which also has an effect on the actuator. For example, the spring element can comprise at least one spiral spring. A multi-part design of the spring element and / or the use of several spring elements is also conceivable. The spring element can in particular be designed at least partially as a closing spring, the closing spring being designed to exert a closing force on the actuator, that is to say a force in a closing direction. A closing direction is generally understood to mean a direction in which the actuator is pressed directly or indirectly into a valve seat so that the hydraulic valve closes. Interconnection of further closing elements is also possible, for example in the case of a ball valve an interconnection of a closing ball. Various configurations are conceivable and known to those skilled in the art. The spring element can in particular be designed and / or dimensioned in such a way that the hydraulic valve is in a closed state without the application of force by the first magnetic actuator and / or the second magnetic actuator. In other words, if the solenoid actuators are not energized, the actuator should be pressed into a closed position by the spring element.


The hydraulic valve can in particular be designed as a non-force-balanced and / or as a non-pressure-balanced hydraulic valve. This means that the actuator of the hydraulic valve is preferably acted upon by a hydraulic fluid, for example the fuel, with a hydraulic force in one direction, hydraulic surfaces predominating in opposite directions in this direction.


The first magnetic actuator and the second magnetic actuator can comprise at least one armature which is connected to the actuator. As will be explained in more detail below, the magnetic actuators can share one or more armatures on which the magnetic actuators and / or their magnetic coils act together, or the magnetic actuators can each comprise separate armatures. A combination of these possibilities is also conceivable in that, for example, each of the magnetic actuators comprises more than one armature, for example at least one armature of its own and at least one armature shared with the other magnetic actuator. An armature is generally to be understood as an element on which a magnetic force can be exerted by means of a magnetic coil. In particular, it can be a soft magnetic and / or ferromagnetic material. For example, the at least one anchor can each comprise at least one anchor plate, that is to say an element with a surface area which preferably exceeds its thickness. The surface extension can in particular be arranged perpendicular to a longitudinal extension of the actuator and / or to an axis of the fuel injector.


The first magnetic actuator can in particular have a first magnetic coil, and the second magnetic actuator can have at least one second magnetic coil. The at least one armature can then be arranged between the first magnetic coil and the second magnetic coil. This can be achieved by providing a common armature for both magnetic actuators, which is arranged between the magnetic coils. An arrangement between the magnetic coils is also possible with a separate embodiment of the armature, for example by arranging a first armature closer to the first magnetic coil and a second armature closer to the second magnetic coil, the two armatures being arranged between the two magnetic coils.


It is particularly preferred if the first magnetic actuator and the second magnetic actuator are at least partially designed with identical components. In particular, they can share at least one common component. The common component can in particular be designed to conduct a magnetic flux. In particular, a magnetic flux of the first magnetic actuator can be superimposed on a magnetic flux of the second magnetic actuator in the common component. In particular, the first magnetic actuator can have at least partially component-identical magnetic cores. As an alternative or in addition, the first magnetic actuator and the second magnetic actuator, as described above, can also include at least partially component-identical armatures. The hydraulic valve can be set up in such a way that the common component can be acted upon by magnetic fluxes in the same direction or in opposite directions.


Furthermore, it is particularly preferred if at least one magnetic core of the first magnetic actuator and / or at least one magnetic core of the second magnetic actuator is at least partially formed by an armature and / or the actuator. In this way, a magnetic flux of the first magnetic actuator and / or a magnetic flux of the second magnetic actuator can be guided at least partially through the armature and / or the actuator. A particularly compact design is possible in this way. For example, an armature can replace at least part of a magnetic core and, for example, form an inner pole. In this way, for example, an armature can be replaced at least part of a magnetic core and, for example, an inner pole can be formed. In this way, for example, a diameter of one or both of the magnetic actuators can be clearly prevented.


The first magnetic actuator and the second magnetic actuator can comprise a common armature which is connected to the actuator. The first magnetic actuator can have a first magnetic coil and the second magnetic actuator a second magnetic coil, the hydraulic valve being set up such that the common armature of the first magnetic coil and the second magnetic coil can be acted upon by a magnetic flux in the same direction. This refinement has the advantage that the polarization of the one magnetic circuit can be built up more quickly when switching, since the polarization of the other magnetic circuit can be used when the magnetic flux is built up.


Alternatively or additionally, however, the hydraulic valve can also be set up in such a way that the common armature of the first magnetic coil and the second magnetic coil can be acted upon by a magnetic flux in opposite directions. This offers the advantage that the flux build-up of one magnetic circuit can be used to reduce the flux of the other magnetic circuit. Both configurations of the magnetic fluxes can also be combined, for example in different switching phases of the hydraulic valve or the fuel injector. As an alternative or in addition to an arrangement of the at least one armature between the magnetic coils, an embodiment is also possible in which the first magnetic actuator has a first armature and the second magnetic actuator has a second armature, the first armature and the second armature on opposite sides of the first Solenoid and the second solenoid are arranged.


The hydraulic valve and the fuel injector have a number of advantages over known hydraulic valves and fuel injectors. In particular, fuel injectors can be produced which are robust with respect to particle contamination, in particular contamination of the fuel, and which can have the robustness of a ball valve. At the same time, the hydraulic valve and the fuel injector can be designed with an overpressure limiting function of a non-pressure compensated valve and can nevertheless be small and light and thus switch quickly.


The hydraulic valve can thus be designed as an actively closing solenoid valve, in particular for use in fuel injectors. Two magnetic circuits can be used, one magnetic circuit, that is to say the magnetic circuit of the first magnetic actuator, for example, in the opening direction of the hydraulic valve and the other in the closing direction of the hydraulic valve, or vice versa. It is particularly useful to use it on hydraulic valves that are not pressure balanced. Part of the necessary closing force for non-pressure compensated valves can be applied by the closing magnetic circuit itself, in particular by one or more of the mentioned magnetic actuators. One advantage of this configuration is that the closing spring can be made smaller and can be pretensioned to be smaller. The magnetic force requirement for the opening magnetic circuit or the opening magnetic actuator is correspondingly lower. Accordingly, smaller armatures, lower moving masses and thus faster hydraulic valves or faster fuel injectors can be implemented.


Another advantage is that the protective magnetic actuator or magnetic circuit has a lower tendency to bounce at the lower stroke stop and thus a progressively increasing closing force. Furthermore, the hydraulic valve and the fuel injector can be designed in such a way that, in a closed state, the magnetic circuit, which has a closing effect, is continuously flown through. The energy stored in this magnetic circuit can then be used as booster energy for the opening magnetic circuit. Accordingly, the energy drawn from a control device can be reduced, for example the energy drawn from a booster capacitor in a control device. Another advantage to be mentioned is that the hydraulic valve can be designed to be intrinsically safe without the need for additional safety measures. Accordingly, the hydraulic valve can be designed in such a way that it opens automatically in the event of excess pressure.

Brief description of the drawings



Embodiments of the invention are shown in the drawings and explained in more detail in the following description.


It show:
Figure 1
a first embodiment of an actively closing hydraulic valve with separate magnetic circuits;
Figures 2 A and 2B
Embodiments with a jointly used magnet armature with magnetic flux in the same direction (FIG. 2A) and magnetic flux in the opposite direction (FIG. 2B);
Figure 3
an embodiment with a jointly used armature, in which the armature is also used as the inner pole of the closing magnetic circuit, with magnetic flux in the same direction (FIG. 3A) and mutual magnetic flux (FIG. 3B); and
Figures 4 A and 4
B an embodiment with a jointly used magnetic core with magnetic flux in the same direction (FIG. 4 A) and magnetic flux in opposite directions (FIG. 4 B).

Embodiments



In Figures 1 to 4B, various exemplary embodiments of hydraulic valves 110 are shown, which can be used in fuel injectors 112. Further parts of the fuel injectors 112 are not shown in the figures. For example, the hydraulic valves 110 can be used in an injector housing, not shown, of the fuel injector 112, in which, for example, an injection valve member can also be stored. The hydraulic valves 110 each have a valve area 114 with a valve seat 116 and a valve bore 118. Valve seat 116 and valve bore 118 can be formed, for example, in an injector body 120, which is only shown partially. The valve bore 118 can, for example, open directly or indirectly into a control chamber of the fuel injector 112, via which a stroke of an injection valve member can be controlled. In addition, the hydraulic valve 110 has a closing element 122 in the valve region 114, which in the exemplary embodiment shown is configured as a ball, for example. However, another configuration is also possible in principle, for example a configuration as a cone, a cone, a spherical cap or in a similar manner. Accordingly, in the exemplary embodiments shown, the hydraulic valve 110 is designed, for example, as a ball valve and / or has such a ball valve.


The closing element 122 is connected to an actuator 124, via which the closing element 122 can be pressed into its valve seat 116 or lifted out of it. In the exemplary embodiment shown, the actuator 124 is designed, for example, as a cylindrical actuator 124 in the form of an actuator rod. However, other configurations are also possible in principle. A compressive force Fp acts through the valve bore 118 on the closing element 122 and thus on the actuator 124, which is derived from the hydraulic pressure PRailand the seat ASeatresults in:



A spring force of a spring element 126 in the form of a closing spring 128 counteracts this hydraulic force. This closing spring 128 is supported at its lower end directly on the actuator 124 or indirectly on this, for example an armature 130 which is connected to the actuator 124 can. This armature is part of two solenoid actuators 132, 134, of which a first solenoid actuator 132 is designed as an opening solenoid actuator and a second solenoid actuator 134 in this exemplary embodiment as a closing solenoid actuator. The magnetic actuators 132, 134 each include a first magnetic coil 136 and a second magnetic coil 138 as well as a first magnetic core 140 and a second magnetic core 142. The magnetic actuators 132, 134 differ in the exemplary embodiments according to FIGS. 1 to 4B with regard to the design of their magnetic cores 140, 142 and with regard to the design and arrangement of their anchors 130. This is explained in more detail below. The first magnetic actuator 132 is set up around a magnetic flux ΦO to generate and the second magnetic actuator 134 is set up to generate a magnetic flux Φc to create. These magnetic fluxes ΦO and Φc are each indicated in the figures by closed, circular arrows.


In Figure 1, an embodiment of a hydraulic valve 110 is shown, which closes actively and in which the magnetic actuators 132, 234 are designed separately, so that the two magnetic circuits of these magnetic actuators 132, 134 essentially not or only minimally influence each other magnetically. The first magnetic actuator 132 has a first armature 144 and the second magnetic actuator 134 has a second armature 146. Both armatures 144, 146 are connected to the actuator 124 and are arranged essentially parallel to one another, one above the other. The magnetic cores 140, 142 of the two magnetic actuators 132, 134 are formed separately from one another in this exemplary embodiment.


In Figures 2A to 4B, however, embodiments are shown in which the first magnetic actuator 132 and the second magnetic actuator 134 influence each other, in particular by their magnetic fluxes ΦO and Φc superimpose one another or influence one another. These designs have the advantage that the energies of the respective other magnetic actuator 132, 134 stored in the magnetic fields can also be used. With the magnetic flux in the same direction, the polarization of the other magnetic circuit can also be used when building up the magnetic flux of one's own magnetic circuit, which leads to a lower energy requirement for building up the magnetic field. This can be done in different ways. For example, the magnetic cores 114, 142 can be at least partially designed with identical components, so that the magnetic fluxes ΦO and Φc can overlay. Alternatively or additionally, however, a common anchor can also be used. Since the direction of the magnetic flux is maintained in the shared part, for example in the shared armature 130 and / or in the shared magnetic core 140, 142 and thus the flux density does not change as much, eddy currents are also reduced in this part. In the case of opposing flows, however, the flow build-up of one magnetic circuit can be used to reduce the flow of the other magnetic circuit.


In Figures 2A and 2B, an embodiment of a hydraulic valve 110 is shown in which a common armature 130 is used. The magnetic coils 136, 138 and the magnetic cores 140, 142 of the magnetic actuators 132, 134 are arranged on opposite sides of this jointly used armature 130. 2A shows an embodiment in which the magnetic fluxes ΦO and Φc are in the same direction within the armature 130, whereas in the embodiment in FIG. 2B these magnetic fluxes ΦO and Φc are designed in opposite directions. Accordingly, in FIG. 2A, when the magnetic flux is built up, ΦO caused by the magnetic flux Φc induced polarization can be used and vice versa, which leads to a lower energy requirement for the magnetic field build-up. Conversely, in the exemplary embodiment according to FIG. 2B, the flux build-up of the magnetic flux ΦO for the flux reduction of the magnetic flux Φc can be used and vice versa.


In Figures 3A and 3B, an embodiment of a hydraulic valve 110 is shown, which initially corresponds essentially to the embodiment according to Figures 2A and 2B. Again, a common armature 130 is used for the two magnetic actuators 132, 134. However, the second magnetic core 142 does not completely surround the second magnetic coil 138 in the center. The actuator 124 and / or part of the armature 130 can thus at least partially take on the role of the magnetic cores 140, 142 in this and also in other exemplary embodiments. In this case, for example, the armature 130 can be used as the inner pole of the closing magnetic circuit of the second magnetic actuator 134, so that part of the magnetic flux Φc runs through this armature 130 and / or the actuator 124. Otherwise, the exemplary embodiment in FIGS. 3A and 3B can essentially correspond to the exemplary embodiment according to FIGS. 2A and 2B, respectively. Again, a magnetic flux in the same direction is shown in FIG. 3A, whereas a magnetic flux in the opposite direction is shown in FIG. 3B.


In FIGS. 4A and 4B, exemplary embodiments are shown in which the magnetic actuators 132, 134 have separate armatures 144, 146, similar to FIG. 1. However, in this exemplary embodiment, the armatures 144, 146 are mutually opposite sides with respect to the magnetic cores 140, 142 arranged. Accordingly, in contrast to the other exemplary embodiments, in the exemplary embodiment shown in FIGS. 142 as the common magnetic cores 148. Accordingly, the magnetic fluxes ΦO and Φc overlay again. Analogous to FIGS. 2A and 2B or 3A and 3B, FIG. 4A again shows an arrangement in which the magnetic fluxes ΦO and Φc are designed in the same direction in the common magnetic core 148, whereas these are designed in opposite directions in the exemplary embodiment according to FIG. 4B.


The advantages described above can be realized by means of the exemplary embodiments shown in FIGS. 1 to 4B. In particular, the closing spring 128 can be designed to be comparatively small and / or provided with a smaller preload, whereby a magnetic force requirement, in particular for the opening magnetic actuator 132, can be reduced. In addition, the anchors 130 can be made smaller. The closing spring 128 can serve as a return spring in all exemplary embodiments and can generate an additional acceleration force for closing the fuel injector 112. This enables a simpler operation of the fuel injector 112 up to a limit rail pressure. If the closing magnetic actuator 134 fails, the hydraulic valve 110 can close automatically. Existing fuel injectors 112 can also be modified by means of the proposed hydraulic valve 110 in one or more of the proposed configurations. The hydraulic valve 110 offers particular advantages for a high operating pressure (rail pressure) with a simultaneous need for very short switching times.



Expectations

1. Hydraulic valve (110) for use in a fuel injector (112) for injecting a fuel into a combustion chamber of an internal combustion engine, wherein the hydraulic valve (110) comprises at least one actuator (124), wherein the hydraulic valve (110) furthermore at least comprises a first magnetic actuator (132) and at least one second magnetic actuator (134), the first magnetic actuator (132) and the second magnetic actuator (134) being set up to act on the actuator (124) with opposing force directions.
 

2. Hydraulic valve (110) according to the preceding claim, wherein the hydraulic valve (110) further comprises at least one spring element (126) which acts on the actuator (124).
 

3. Hydraulic valve (110) according to the preceding claim, wherein the spring element (126) is at least partially designed as a closing spring (128), the closing spring (128) being designed to exert a closing force on the actuator (124).
 

4. Hydraulic valve (110) according to one of the two preceding claims, wherein the spring element (126) is designed such that the hydraulic valve (110) without application of force by the first magnetic actuator (132) and by the second magnetic actuator (134) in one closed state.
 

5. Hydraulic valve (110) according to one of the preceding claims, wherein the hydraulic valve (110) is designed as a non-force-balanced and / or non-pressure-balanced hydraulic valve (110).
 

6. Hydraulic valve (110) according to one of the preceding claims, wherein the first magnetic actuator (132) and the second magnetic actuator (134) comprise at least one armature (130) which is connected to the actuator (124), wherein the first magnetic actuator ( 132) has a first magnetic coil (136), the second magnetic actuator (134) having a second magnetic coil (138), the armature (130) being arranged between the first magnetic coil (136) and the second magnetic coil (138).
 

7. Hydraulic valve (110) according to one of the preceding claims, wherein the first magnetic actuator (132) and the second magnetic actuator (134) comprise at least one common component, in particular a common armature (130) and / or a common magnetic core (148), wherein the hydraulic valve (110) is set up in such a way that the common component can be acted upon by magnetic fluxes in the same direction or in opposite directions.
 

8. Hydraulic valve (110) according to one of the preceding claims, wherein the first magnetic actuator (132) and the second magnetic actuator (134) comprise a common armature (130) which is connected to the actuator (124).
 

9. Hydraulic valve (110) according to one of the preceding claims, wherein the first magnetic actuator (132) and the second magnetic actuator (134) have at least partially component-identical magnetic cores (148).
 

10. Hydraulic valve (110) according to one of the preceding claims, wherein at least one magnetic core (140, 142; 148) of the first magnetic actuator (132) and / or of the second magnetic actuator (134) at least partially from an armature (130) and / or the actuator (124) is formed.
 

11. Hydraulic valve (110) according to one of the preceding claims, wherein the first magnetic actuator (132) has a first armature (144), wherein the first armature (144) is connected to the actuator (124), wherein the second magnetic actuator (134 ) has a second armature (146), the second armature (146) being connected to the actuator (124), the first magnetic actuator (132) having a first magnetic coil (136), the second magnetic actuator (134) having a second magnetic coil (138), wherein the first armature (144) and the second armature (146) are arranged on opposite sides of the first magnetic coil (136) and the second magnetic coil (138).
 

12. Fuel injector (112) for injecting fuel into the combustion chamber of an internal combustion engine, in particular from a high-pressure accumulator, the fuel injector (112) having at least one injection opening and at least one injection valve member which releases or closes the injection opening, the injection valve member being controlled by at least one hydraulic Valve (110) according to one of the preceding claims.