EP3364016A1 - Electromagnetic switching valve and high-pressure fuel pump - Google Patents

Abstract

The invention relates to an electromagnetic switching valve (30) for a fuel injection system (10) of an internal combustion engine having an actuator region (38) for moving a closing element (48) with a pole piece (40) and an armature (44) and a solenoid (52) Generating a magnetic flux in the armature (44) and pole piece (40), wherein the pole piece (40) has a magnetic flux concentration region (66).

Description

The invention relates to an electromagnetic switching valve for a fuel injection system of an internal combustion engine, as well as a high-pressure fuel pump having such an electromagnetic switching valve.

High-pressure fuel pumps in fuel injection systems in internal combustion engines are used to pressurize a high-pressure fuel, the pressure is for example in gasoline engines in the range of 150 bar to 400 bar and diesel engines in the range of 1500 bar to 2500 bar. The higher the pressure that can be generated in the respective fuel, the lower are emissions that occur during combustion of the fuel in a combustion chamber, which is particularly advantageous against the background that a reduction of emissions is increasingly desired.

In the fuel injection system, valve assemblies may be provided at various positions along the path fuel takes from a tank to the respective combustion chamber, for example as an intake or exhaust valve on a high pressure fuel pump that pressurizes the fuel, but also as a relief valve at various positions, for example the fuel injection system, for example on a common rail, which stores the pressurized fuel before injection into the combustion chamber.

Frequently, fast-switching solenoid valves for volume flow and / or pressure control are used for this purpose. Depending on the flow rate and type holds a return spring a closing element a valve region of such an electromagnetic switching valve against a flow open or closed. The associated actuator region, that is the magnetic actuator which opens or closes the closing element, is designed in such a way that the return spring can overpress the actuator force of the magnetic actuator in a specific time, thus switching the switching valve.

These switching valves are accordingly constructed as a combination of a switching magnet, which operates the magnetic actuator, with a hydraulic connected through this, the valve region. In operation, two switching states of the hydraulics, an open position and a closed position, are thus achieved.

The switching magnet has in the actuator region by a force-generating air gap separate components, namely a movable armature and a fixed pole core, which are held by the return spring from each other at a distance. By activating a solenoid in the switching magnet by applying electrical current, a magnetic field is built up in a winding of the solenoid. This magnetic field induces a magnetic flux into the surrounding metal components, in particular in the armature and the pole core, so that a magnetic force is built up between the armature and the pole core. By this magnetic force, a restoring force of the return spring is overcome and controlled the coupled hydraulic. By removing the electrical current, the magnetic force decreases and the restoring force controls the hydraulics in the starting position.

So far, the dynamics of the switching valve has been designed for the operating condition where the fastest switching characteristic is required during operation. As a result, however, the momentum forces between the switching magnetic components, namely the armature and the pole core, become very high.

The switching valve has hitherto been designed so that in the operating point, in which the maximum air gap between armature and pole core, and in which an equilibrium of forces between the return spring and the magnetic force of the solenoid is established, the highest possible magnetic flux density in the air gap between the armature and pole core so that the moving components are excited to move as quickly as possible. Within the movement process, the moving components are then further accelerated by the magnetic force and the air gap is reduced. In the state of the minimum air gap, the magnetic force is then maximum.

The momentum forces depend on the mass of the moving components and their speed. With high pulse forces, the consequence is that a high degree of wear can occur between the components and the sound noises during operation are very high. Noise occurs with each change of the switching state, both by the solenoids themselves, as well as by the hydraulics. At least two components hit each other and thus generate noise.

For example, such a switching valve is used as a digital intake valve on a high-pressure fuel pump in a fuel injection system of an internal combustion engine. The switching time of such an intake valve is designed so that it is able to switch quickly even at the highest engine speed of the internal combustion engine. However, this is in contrast to the goal that in any other operating condition of the internal combustion engine, namely at engine idle, no significant noise should be generated.

So far, the switching valve has been designed for the switching time for the operating point with the highest switching dynamics. Attempts were made to avoid noise and wear for movements that oppose the switching direction of the switching magnet are directed to intercept with short-term current pulses to increase the magnetic force. However, it is difficult to mitigate movements in the switching direction of the switching valve.

The object of the invention is therefore to provide an electromagnetic switching valve, in which a noise development can be reduced to a minimum in all operating points.

This object is achieved with an electromagnetic switching valve with the feature combination of claim 1.

A high-pressure fuel pump having such an electromagnetic switching valve is the subject of the independent claim.

Advantageous embodiments of the invention are the subject of the dependent claims.

An electromagnetic switching valve for a fuel injection system of an internal combustion engine has a valve region with a closing element for closing the switching valve and an actuator region for moving the closing element along a movement axis. The actuator region includes a movable armature along the axis of motion, which is coupled to the closing element for moving the closing element, a fixed pole piece and a solenoid for generating a magnetic flux in the armature and the pole piece. The pole piece has a magnetic flux concentration area.

By having the pole piece having a magnetic flux concentration region, that is, a region in which the magnetic flux induced by the solenoid is concentrated, a magnetic reactor is formed in the pole piece. In operation becomes normally the solenoid is energized until the closure member begins to move. This is the so-called working point. Even after reaching this operating point, the excitation by the solenoid will normally increase as the solenoid continues to be charged with increasing current. Despite this increasing excitation by the solenoid, the magnetic flux in the region of the magnetic throttle in the pole piece now comes into magnetic saturation, so that the acceleration of the armature is limited in the direction of the pole piece. As a result, the acting magnetic force at rest and thus at the same time the force level is reduced during operation.

Preferably, the magnetic flux concentration region is formed by a constriction in a pole piece outer periphery.

This reduces the pole piece outer circumference in the area of the constriction compared to the remainder of the pole piece outer circumference, and the magnetic field lines flowing through the pole piece must share the space in this constricted area. This results in a concentration of the magnetic field lines and thus the magnetic flux in this region of the constriction of the pole piece. By this constriction then the magnetic throttle is formed as described above.

The armature and the pole piece are arranged adjacent to each other. Advantageously, the constriction is arranged in an armature facing half of the pole piece. In this case, the constriction is particularly advantageously at least 1/5 of an overall length of the pole piece along the movement axis.

In an advantageous embodiment, the pole piece outside the constriction has a constant pole piece outer circumference, wherein the pole piece outer circumference in the region of the constriction is reduced by at least 1/4 compared to the constant region. Accordingly, the constriction is arranged at a defined height in the pole piece and with a defined diameter and a defined length so as to be able to achieve a defined magnetic flux concentration in the pole piece.

• Durch die Einschnürung wird nicht nur eine Magnetflusskonzentration in dem Polstück erreicht, sondern auch insgesamt die Masse des Polstückes reduziert. Außerdem wird die gewünschte Magnetkraft schneller als bislang erreicht, was mit einer Schaltzeitreduktion des Schaltventiles einhergeht. Gleichzeitig wird der Anker in der Bewegungsphase nicht so stark beschleunigt, wobei dennoch die Geschwindigkeit der bisher bekannten entspricht. Insgesamt wird die Gesamtschaltzeit reduziert und somit verbessert.

Due to the constriction, the overall effects are as follows:

• The constriction not only reaches a magnetic flux concentration in the pole piece, but also reduces the mass of the pole piece as a whole. In addition, the desired magnetic force is reached faster than previously, which is associated with a switching time reduction of the switching valve. At the same time, the armature is not accelerated so much in the movement phase, yet the speed of the previously known corresponds. Overall, the total switching time is reduced and thus improved.

Between anchor and pole piece, a return spring is arranged, which is supported in the pole piece in a spring recess. In this case, the spring recess is defined by side walls of a through hole in the pole piece and by supporting walls on which the return spring is supported. The constriction is advantageously arranged along the axis of movement at the height of this spring recess.

In this case, this constriction is completely arranged at the height of the spring recess and is not on this out. Nevertheless, it is advantageous if the constriction on the pole piece is not located at an end region, but is bounded on both sides by regions which have the constant and thus larger pole piece outer circumference.

This ensures that advantageously a pole piece surface which is directly adjacent to the armature, has the greatest possible extent, so as to realize a particularly good magnetic interaction with the armature.

Preferably, the solenoid is arranged around the pole piece. The constriction along the axis of movement is arranged at the level of the solenoids. This results in that a particularly good concentration of the magnetic flux generated by the solenoid in the pole piece can be achieved.

Preferably, a constant armature outer circumference substantially corresponds to the constant pole piece outer circumference, that is to say the larger outer circumference of the pole piece in the region in which it has no constriction. The armature outer circumference has a shoulder in the armature area directly adjacent to the pole piece, at which point the armature outer circumference merges into a reduced armature outer circumference.

This means that also the armature is reduced in its outer circumference in a region, namely at an end region of the armature, which is directly adjacent to the pole piece. As a result, a magnetic flux concentration can also be achieved in the armature, which leads to an improved switching time of the switching valve. The mass of the armature is thus reduced, which reduces the mechanical impulse when the armature strikes the pole piece. The reduced armature outer circumference is advantageously at most 3/4 of the constant armature outer circumference.

Preferably, the reduced armature outer circumference along the axis of motion is substantially half the total length of the armature.

Thus, a defined magnetic flux concentration and thus a defined magnetic throttle is formed at the armature, which can cooperate with the magnetic throttle of the pole piece.

A high-pressure fuel pump for a fuel injection system of an internal combustion engine advantageously has an electromagnetic switching valve described above.

In this case, the switching valve may be formed, for example, as an inlet valve for the high-pressure fuel pump or as an exhaust valve. However, it is also possible to provide the described switching valve as a pressure regulating valve, which is arranged for example on a common rail of a fuel injection system.

Fig. 1

eine schematische Übersichtsdarstellung eines Kraftstoffeinspritzsystems einer Brennkraftmaschine, das an verschiedenen Positionen ein elektromagnetisches Schaltventil aufweisen kann;

Fig. 2

eine Längsschnittdarstellung eines der Schaltventile aus Fig. 1 als Einlassventil an der Kraftstoffhochdruckpumpe in einer ersten Ausführungsform;

Fig. 3

eine Längsschnittdarstellung des Schaltventils aus Fig. 2 mit im Betrieb wirkenden Magnetfeldlinien;

Fig. 4

eine Längsschnittdarstellung eines der Schaltventile aus Fig. 1 als Einlassventil an der Kraftstoffhochdruckpumpe in einer zweiten Ausführungsform;

Fig. 5

eine Längsschnittdarstellung des Schaltventils aus Fig. 4 mit im Betrieb wirkenden Magnetfeldlinien; und

Fig. 6

ein Diagramm, das die im Betrieb wirkende Magnetkraft der Schaltventile aus Fig. 2 und Fig. 4 gegen die magnetische Anregung durch den Solenoiden darstellt.

Advantageous embodiments of the invention will be explained in more detail with reference to the accompanying drawings. It shows:

Fig. 1

a schematic overview of a fuel injection system of an internal combustion engine, which may have an electromagnetic switching valve at various positions;

Fig. 2

a longitudinal sectional view of one of the switching valves Fig. 1 as an intake valve to the high-pressure fuel pump in a first embodiment;

Fig. 3

a longitudinal sectional view of the switching valve Fig. 2 with operating magnetic field lines;

Fig. 4

a longitudinal sectional view of one of the switching valves Fig. 1 as an intake valve to the high-pressure fuel pump in a second embodiment;

Fig. 5

a longitudinal sectional view of the switching valve Fig. 4 with operating magnetic field lines; and

Fig. 6

a diagram showing the operating magnetic force of the switching valves Fig. 2 and Fig. 4 against the magnetic excitation by the solenoids.

Fig. 1 shows a schematic overview of a fuel injection system 10 of an internal combustion engine, which promotes a fuel 12 from a tank 14 via a prefeed pump 16, a high-pressure fuel pump 18 and a high-pressure fuel storage 20 to injectors 22, which then inject the fuel 12 into combustion chambers of the internal combustion engine.

The fuel 12 is introduced via an inlet valve 24 into the high-pressure fuel pump 18, pressurized via an outlet valve 26 out of the high-pressure fuel pump 18, and then fed to the high-pressure fuel accumulator 20. At the high-pressure fuel storage 20, a pressure control valve 28 is arranged to control the pressure of the fuel 12 in the high-pressure fuel storage 20 can.

Both the inlet valve 24, and the outlet valve 26, as well as the pressure control valve 28 may be formed as electromagnetic switching valves 30 and therefore operated actively.

Fig. 2 shows a first embodiment of such an electromagnetic switching valve 30 in a longitudinal sectional view through the electromagnetic switching valve 30, which is designed as an inlet valve 24 of a high-pressure fuel pump 18.

The electromagnetic switching valve 30 is arranged in a housing bore 32 of a housing 34 of the high-pressure fuel pump 18. The electromagnetic switching valve 30 has a valve region 36 and an actuator region 38, wherein the actuator region 38 has a fixed pole piece 40 and an armature 44 movable along a movement axis 42. The valve region 36 comprises a valve seat 46 and a closing element 48, which cooperate to close the electromagnetic switching valve 30.

In the in Fig. 2 In the embodiment shown, the pole piece 40 and the armature 44 are accommodated together in a sleeve 50, although this need not necessarily be the case.

A solenoid 52 is pushed onto the sleeve 50 and is thus located around the pole piece 40 and the armature 44 disposed in the electromagnetic switching valve 30.

The armature 44 and the pole piece 40 are disposed directly adjacent to each other so that an armature surface 54 and a pole piece surface 56 are directly opposed.

A return spring 58 is disposed between the armature 44 and the pole piece 40 to space the armature 44 and pole piece 40, thus creating an air gap 60.

The armature 44 is coupled to an actuating pin 62 which moves in operation with the armature 44 along the axis of movement 42.

Depending on the switching state and thus position of the armature 44 along the axis of movement 42, the actuating pin 62 pushes the closing element 48 away from the valve seat 46 or has no contact with the closing element 48, so that this, if from the opposite Side a force acts to move the valve seat 46 and thus close the switching valve 30.

In the energized state of the electromagnetic switching valve 30, the solenoid 42 generates a magnetic field in the electromagnetic switching valve 30, which in Fig. 3 represented by magnetic field lines 64. As in Fig. 3 In this case, the magnetic flux of the magnetic field lines 64 is arranged in all directly adjacent to the solenoid 52 metallic / magnetic elements, in particular in the pole piece 40 and in the armature 44. This creates a magnetic attraction between the pole piece 40 and armature 44, and the Anchor 44 is pulled with its armature surface 54 in the direction of the pole piece surface 56 of the pole piece 40. In this case, the armature 44 takes the actuating pin 62 so that it loses contact with the closing element 48, and the closing element 48 can thus return to the valve seat 46.

Since the armature 44 moves toward the pole piece 40 when the solenoid 52 is switched on, the air gap 60 in the switched-on state is minimal.

In the off state, however, the return spring 58 pushes the armature 44 away from the pole piece 40 again, since a restoring force of the return spring 58 counteracts the magnetic force. The air gap 60 is maximum and the actuating pin 62 is pressed back onto the closing element 48, so that the closing element 48 lifts off from the valve seat 46 and the electromagnetic switching valve 30 opens.

In the in Fig. 2 and Fig. 3 In the embodiment shown, it can be seen that the armature 44 has a magnetic flux concentration region 66, that is to say a region in which the magnetic field lines are guided on a reduced cross-sectional area through the armature 44, so that they must concentrate.

The magnetic flux concentration region 66 is formed in that an armature outer circumference U _{A has} a shoulder 68, so that a first armature outer circumference U _A1 and a second armature outer circumference U _A2 form, which are different from each other, wherein the first armature outer circumference U _{A1 is} smaller than the second armature outer circumference U _A2 .

It can be seen that the armature 44 has the first armature outer circumference U _A1 in the region in which the armature 44 is assigned directly adjacent to the pole piece 40, that is to say at its upper end region 70.

The first armature outer circumference U _A1 amounts to a maximum of 3/4 of the second armature outer circumference U _A2 . In addition, a length of the first armature outer circumference U _A1 along the movement axis 42 is substantially half of an overall length L _{A of} the armature 44.

As a result of this arrangement of the reduced first armature outer circumference U _A1 , a targeted magnetic throttle can be produced in the armature 44 in order to achieve the advantages described above. The course of the magnetic field lines 64 is in Fig. 3 It can be seen that the magnetic field lines 64 concentrate in the region in which the armature outer circumference U _{A is} reduced, so that here the total magnetic flux concentrates.

Out Fig. 2 It is also apparent that the armature surface 54 facing the pole piece 40 at the upper end portion 70 is smaller than the pole piece surface 56 which is directed toward the armature 44. In this case, the armature surface 54 makes up about half of the pole piece surface 56.

The two opposing surfaces, namely the armature surface 54 and the pole piece surface 56, are the surfaces which generate the magnetic force between armature 44 and pole piece 40.

In the conventional design, that is, when the armature 44 has a constant armature outer circumference U _A , sets a magnetic flux density, which is located at the armature surface 54 and the pole piece surface 56 in terms of value in about the same range. Now, however, the armature surface 54 and the pole piece surface 56 are formed to have different sizes, so that the magnetic flux saturates shortly after the magnetic force of the solenoid 52 has exceeded the restoring force of the return spring 58, as described later with reference to FIG Fig. 6 is explained.

Fig. 4 and Fig. 5 show a second embodiment of the electromagnetic switching valve 30, in which the magnetic throttle is provided by providing the magnetic flux concentration region 66 not in the armature 44 as in the first embodiment, but in the pole piece 40.

However, it is also possible to combine both embodiments, so that both the armature 44 and the pole piece 40 each form a magnetic flux concentration region 66 and thus a magnetic throttle.

The magnetic flux concentration region 66 in the second embodiment is formed by a constriction 72 in the pole piece 40, so that a pole piece outer circumference U _P , which is otherwise constant across the movement axis 42, is reduced in the region of the constriction 72.

The constriction 72 is disposed in a half 74 of the pole piece 40, which is arranged facing the armature 44, but not, as in the armature 44 in the first embodiment, on a End portion, but at a Polstückendbereich 76 spaced. It is thereby achieved that where the pole piece surface 56 is adjacent to the anchor surface 54, the maximum magnetic force from the pole piece 40 can act on the armature 44 to pull the armature 44 toward the pole piece 40.

The constriction 72 has a length which corresponds to at least 1/5 of a length L _{P of} the pole piece 40 along the movement axis 42. The Polstückaußenumfang U _P is reduced in the region of the constriction 72 by at least 1/4 compared to the constant Polstückaußenumfang U _P outside of the constriction 72.

As in Fig. 4 . Fig. 5 , but also in Fig. 2 and Fig. 3 , it can be seen, the return spring 58 is arranged so that it is supported within the pole piece 40. For this purpose, the pole piece 40 has a through hole 78, which expands in a lower Polstückendbereich 78, which is arranged facing the armature 44, to form a spring recess 82. The spring recess 82 is defined by side walls 84 of the through hole 78 and by support walls 68, which are formed by the extension of the through hole 78 in Polstückendbereich 78. At this Abstützwänden 68 then the return spring 58 is supported.

As in Fig. 4 can be seen, the constriction 72 along the axis of movement 42 is formed at the level of the spring recess 82, in particular so that it does not protrude beyond the spring recess 82. As a result, the magnetic flux concentration can be achieved, in particular in the region of the return spring 58, that is, where the restoring force of the return spring 58 also acts.

It can also be seen that the constriction 72 is advantageously also at the level of the solenoid 52 along the axis of movement 42.

In Fig. 5 the course of the magnetic field lines 64 is shown in the pole piece 40, wherein it can be seen that concentrate in the region of the constriction 72, the magnetic field lines 64, and thus a magnetic flux concentration in the pole piece 40 can be generated. Thus, the magnetic throttle generated in the armature 44 with respect to the first embodiment can also be generated in the pole piece 40.

The operation of the magnetic chokes in the armature 44 and / or pole piece 40 will be described below with reference to FIG Fig. 6 explained.

Fig. 6 shows a diagram representing the magnetic force generated by the solenoid 52 and the effective magnetic flux in the armature 44 and the pole piece 40 against the magnetic excitation by the solenoid 52.

The dashed lines correspond to the effective magnetic force in a known arrangement in which the armature 44 and the pole piece 40 have no magnetic flux concentration region 66. The solid lines on the other hand show the acting magnetic force in an embodiment of the armature 44 and the pole piece 40 with magnetic flux concentration.

The horizontal line in the diagram indicates the magnetic force to be generated by the solenoid 52, which is necessary to override the restoring force of the return spring 58, so that the armature 44 starts to move.

The two lines, which represent the switching on of the switching valve 30, are marked with "ON".

The two lines that represent the switch-off of the switching valve 30 are marked with "OFF".

Overall, therefore, the diagram each shows a portion of a hysteresis that occurs during operation of the switching valve 30.

It can be seen from the diagram that when switching off in the absence of magnetic throttling in the armature 44 / the pole piece 40, the magnetic force after pressing the restoring force continues to rise sharply and hardly enters a saturation region. In contrast, it can be seen that when a magnetic throttling at the armature 44 / the pole piece 40 is present, shortly after overriding the restoring force of the return spring 58, the magnetic force comes in a saturation region and does not increase further. Thus, a reduced acceleration of the armature 44 is effected in the movement phase, so that then the impulse when turning the armature 44 is reduced in the pole piece 40. The noise when switching the switching valve 30 can thus be significantly reduced.

When turning off, it can be seen that the magnetic force in the presence of the magnetic throttle in the armature 44 / in the pole piece 40 returns earlier to the point at which the force equilibrium with the restoring force of the return spring 58 is set, as is the case when the magnetic throttle is not is present.

This means that the switch-off operation of the switching valve 30 is faster than was previously the case. As a result, the total switching time of the switching valve 30 is significantly reduced and thus improved to the prior art.

Although overall, as shown in the diagram in Fig. 6 can be seen, the magnetic force reduced by the magnetic throttle, but this can be done by appropriate winding parameters in the Solenoids 52 are balanced, if there is a need. It would also be possible to readjust this via the electrical resistance that affects the current in the solenoids 52.

Claims (10)

An electromagnetic switching valve (30) for a fuel injection system (10) of an internal combustion engine, comprising: - A valve region (36) having a closing element (48) for closing the switching valve (30); and - An actuator region (38) for moving the closing element (48) along a movement axis (42); wherein the actuator portion (38) includes an armature (44) movable along the movement axis (42) and coupled to the closure member (48) for moving the closure member (48), a fixed pole piece (40), and a solenoid (52) for generating a magnetic flux in the armature (44) and the pole piece (40), wherein the pole piece (40) has a magnetic flux concentration region (66). Electromagnetic switching valve (30) according to claim 1, characterized in that the magnetic flux concentration region (66) is formed by a constriction (72) in a pole piece outer circumference (U _P ). Electromagnetic switching valve (30) according to claim 2, characterized in that the armature (44) and the pole piece (40) are arranged adjacent to each other, wherein the constriction (72) in a armature (44) facing half (74) of the pole piece ( 40), wherein the constriction (72) is in particular at least 1/5 of an overall length (L _P ) of the pole piece (40) along the movement axis (42). Electromagnetic switching valve (30) according to one of claims 2 or 3,
characterized in that the pole piece (40) outside the constriction (72) has a constant pole piece outer circumference (U _P ) wherein the Polstückaußenumfang (U _P ) in the region of the constriction (72) is reduced by at least 1/4. Electromagnetic switching valve (30) according to one of claims 2 to 4,
characterized in that between armature (44) and pole piece (40) a return spring (58) is arranged, which in the pole piece (40) in a spring recess (82) is supported, wherein the spring recess (82) by side walls (84) of a Through hole (78) in the pole piece (40) and by support walls (86) is defined, on which the return spring (58) is supported, wherein the constriction (72) along the movement axis (42) at the level of the spring recess (82) is arranged , Electromagnetic switching valve (30) according to one of claims 2 to 5,
characterized in that the solenoid (52) is disposed about the pole piece (40), wherein the constriction (72) along the axis of movement (42) at the level of the solenoid (52) is arranged. Electromagnetic switching valve (30) according to one of claims 4 to 6,
characterized in that a constant outer armature circumference (U _A ) substantially corresponds to the constant Polstückaußenumfang (U _P ), wherein the armature outer circumference (U _A ) in the pole piece (40) directly adjacent anchor region has a shoulder (68), on which the Ankeraußenumfang (U _A2 ) merges into a reduced armature outer circumference (U _A1 ). Electromagnetic switching valve (30) according to claim 7,
characterized in that the reduced outer armature circumference (U _A1 ) is at most 3/4 of the constant outer armature circumference (U _A2 ). Electromagnetic switching valve (30) according to one of claims 7 or 8,
characterized in that the reduced armature outer circumference (U _A1 ) along the movement axis (42) is substantially half (74) of an overall length (L _A ) of the armature (44). High-pressure fuel pump (18) for a fuel injection system (10) of an internal combustion engine, comprising an electromagnetic switching valve (30) according to one of claims 1 to 9.

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