DE102006043677A1 - Solenoid valve controlling method for internal combustion engine, involves carrying out secondary current flow of solenoid valve, where secondary current flow causes attenuation of oscillations of armature plate of set of armatures - Google Patents

Abstract

The method involves carrying out a secondary current flow of a solenoid valve (1), where the secondary current flow causes an attenuation of oscillations of an armature plate (5) of a set of armatures. The valve is directly controlled by the secondary current flow approximate to a primary current flow, where the controlling of the valve includes the primary current flow with a holding current. Impinging of the armature plate is avoided on a lower stopper (12) by the secondary current flow, where the secondary current flow takes place depending on a compression factor. Independent claims are also included for the following: (1) a control device for controlling a solenoid valve (2) a computer program that executes in a control device for controlling a solenoid valve.

Description

The Invention relates to a method for controlling a solenoid valve, wherein the solenoid valve comprises an anchor group comprising at least one element having.

The Invention also relates to a control device for controlling a solenoid valve, wherein the solenoid valve comprises an anchor group comprising at least one element having.

The The invention further relates to a computer program that is used in a computing device, in particular in a control unit for the Control of a solenoid valve, expires.

was standing of the technique

One an armature group exhibiting solenoid valve is for example as Part of a known from the market fuel valve trained. Such a solenoid valve comprises a valve element, which with a Valve seat cooperates and release a flow path of a fluid and can lock. The valve element is actuated electromagnetically. For this the armature group comprises a magnetic armature or armature which is connected to the Valve element is coupled. The anchor is accommodated in an anchor space, around which a magnetic coil is arranged. By a valve spring becomes the armature and thereby the valve element in an electroless End position pressed. In this end position, the flow path of the fluid is blocked.

By an electric current supply to the magnet coil surrounding the armature space, For example, by means of a so-called Hauptbestromung, the Armature and the valve element against the force of the valve spring moves become. For this purpose, the anchor group includes, for example, a Anchor plate, wherein the magnetic force of the energized solenoid such acting on the armature plate that these are in the direction of the magnetic coil emotional. In such a running Solenoid valve, the anchor plate is positively connected to the anchor, so that the anchor together with the anchor plate against the Force of the valve spring moves. This in turn causes the flow of the Fluids is released.

ends the energization of the solenoid valve, so is the solenoid no magnetic field generated, the anchor plate and thus the Anchor in the open Position of the solenoid valve stops. Instead, outweighs then the force of the magnetic spring counteracting the valve spring. This acts on the armature in such a way that it moves away from the magnet coil. This in turn causes a valve disposed in the valve element Valve ball closes an outlet throttle.

One Such solenoid valve is, for example, in an injector for the fuel metering used in an internal combustion engine. The amount and the time The metering of the fluid or the fuel takes place in dependence from the energization of the solenoid valve.

In many applications are as short as possible distances desired between individual metering. For example, can in an internal combustion engine a particularly uniform and efficient combustion of the metered fuel by so-called Pre-injections done. This will be low in very short time intervals Metered amounts of fuel. This is especially a achieved particularly quiet running of the internal combustion engine.

The End of the energization of the solenoid valve often has the consequence that individual Elements of the anchor group start to oscillate. For example The anchor may be affected by the impact of the valve ball against the seat the outlet throttle is in vibration. But especially The anchor plate get into vibration, as these are at a End of the current supply first due to the frictional Connection with the anchor also like this through the valve spring charged moved. While However, the movement of the armature by the against the seat of the outlet throttle impinging valve ball is stopped in their movement, can the armature plate move along this direction. In this Movement is the anchor plate by a so-called anchor spring braked. The movement that the anchor plate in this case already continue the decelerated anchor can, is called overstroke. At one end of the energization of the solenoid valve can consequently the Anchor plate within the range specified by the overstroke continue to oscillate.

such Vibrations are for example referred to as anchor bounces and impair the Zumessgenauigkeit, because on the one hand in the armature space fluid is vibrated and on the other hand by the swinging masses a clearly defined opening of the Valve element or a clearly defined flow cross-section during a renewed energization is not guaranteed can be.

It Object of the invention, a control of a solenoid valve to provide, achieved by means of an increased metering accuracy can be.

The object is achieved by a method of the type mentioned in that a Nachbestromung the solenoid valve is performed, wherein the Nachbestromung causes a damping of vibration of at least one element of the armature group.

Advantages of invention

A Such Nachbestromung is referred to as a so-called braking current, since it is suitable, the vibrations of at least one element of Anchor group to brake. In particular, the braking current is suitable to dampen the vibrations of the anchor plate.

By the Nachbestromung becomes a magnetic field in the magnetic coil generated, which acts on the anchor plate with a in the direction of Magnetic coil directed force causes. This force in turn causes a damping the oscillation of individual elements of the anchor group, in particular the anchor plate and the anchor.

Especially the swinging within the overstroke Anchor plate can thereby be braked. The anchor plate vibrates Consequently, in terms of time not as long as it would without a Nachbestromung invention the case would be. This means that the time between two injections will be shortened can, while still a high metering accuracy is possible.

Preferably the anchor plate has an overstroke of more than 10 μm on. If this is the case, then by means of the method according to the invention relative independence from the concrete overtravel be achieved. This means that, for example, solenoid valves, whose anchor plates have 20 μm overstroke, in terms of a Nachbestromung behave just like solenoid valves, an overstroke of 40 microns have and be driven with the same Nachbestromung. The inventive method is therefore universal in such strokes for damping the anchor plate can be used.

According to one advantageous embodiment of the inventive method, in which the activation of the solenoid valve comprises a main current supply, the solenoid valve by means of the Nachbestromung at least approximately immediately then to the main power supply driven.

Around one possible fast response of the solenoid valve with a main current supply To reach, the solenoid valve is initially in an opening phase with a current driven, with a steep, well-defined Flank, for example, rises to about 20 amps. The opening phase describes the phase while which starts a Hauptbestromung the solenoid valve, but still no movement of the anchor itself takes place. Only in the so-called Suit phase takes place a movement of the anchor due to the continue sustained main current supply of the solenoid valve.

is the solenoid valve opened, that's how it often gets operated in a so-called holding current phase, wherein the current across from the opening phase and the suit phase is lowered. Will be right after finishing the Holding current phase as the last part of the main current the Nachbestromung initiated, so a particularly rapid damping of the anchor bounce, so the vibrations of the armature or the anchor plate can be achieved. This is especially for very short consecutive opening cycles of the solenoid valve, so for example particularly fast to each other following injection cycles, advantageous.

A immediately after a Hauptbestromung subsequent Nachbestromung has the Advantage that for the Nachbestromung necessary electricity does not need to be rebuilt. Rather, it's just for that be ensured that the Nachbestromung initiated so quickly will that for the main current required current has not yet dropped to zero is, but only one for the recharge has reached its intended value. It is the Nachbestromung expediently so designed that by the Nachbestromung in the magnetic coil Although the magnetic field generated makes it possible to close the solenoid valve, but still a cushioning the oscillation of the anchor plate is achieved.

has the control of the solenoid valve during the main current no Holding current phase, so it is advantageous, the Nachbestromung invention nearly immediately after the end of the tightening phase or the opening phase, then that even with such solenoid valves particularly short distances between individual opening cycles are reachable.

According to one Another advantageous embodiment of the method according to the invention the solenoid valve is controlled by means of a remote Nachbestromung. If the solenoid valve during the Main energization controlled by a holding current, so means a remote Nachbestromung that the Nachbestromung invention temporally discontinued, so after a predetermined period of time, is performed.

When the solenoid valve is used in an injector for fuel metering in an internal combustion engine, the fuel is often metered in one or more pilot injections and a main injection. A re-energizing remote from such Hauptbestromungen means here, that the opening current, the starting current and the holding current are switched off and for the predetermined period of time as long as no energization of the solenoid valve takes place until the Nachbestromung is initiated.

Closes the Nachbestromung directly or almost directly, for example to the holding phase, so that the closing of the solenoid valve is influenced, because by the Nachbestromung the magnetic field weakened upright is obtained. This means that the anchor and the anchor plate slower in the closing direction move, since the weakened Magnetic field counteracts the force of the valve spring. By means of a remote Nachbestromung, however, is an uninfluenced closing the Anchor ensured.

The means that the closing speed the anchor did not change and thus a simultaneous closing as in a conventional Current supply possible is. This also means that the injection quantity at one injection with a remote Nachbestromung and without a Nachbestromung can be identical in principle. In order to can the remote Nachbestromung without modification of already existing Additional lighting process be used to cushioning the anchor bounce and thus an increased metering accuracy of the solenoid valve to reach.

According to one further advantageous embodiment the method according to the invention follows approximately the Nachbestromung immediately following main energization. A main energizing can For example, control a pilot injection or a post-injection. Starts the following Hauptbestromung example with an opening current, so may in this embodiment a especially fast opening of the solenoid valve can be achieved, as necessary for the main current supply Magnetic already during the Nachbestromung is already partially built and thus the for the opening of the Solenoid valves necessary power can be achieved faster. In order to can therefore particularly fast successive energizing cycles at high Metering accuracy can be achieved.

According to one further advantageous embodiment of the method according to the invention, in which the solenoid valve comprises an armature plate and a stop, becomes due to the Nachbestromung an impact of the anchor plate prevents the stop. The Nachbestromung thus allows that through the Nachbestromung formed in the electromagnet magnetic field weakens the anchor plate so and thus enhances the effect of the armature spring such that the anchor plate does not cover the full stroke of the overstroke. This will be a special fast damping reached the anchor plate. Furthermore, it is achieved by that a striking of the anchor plate to the stop no further vibrations can arise so that by doing an increase the metering accuracy is achieved.

Especially It is advantageous if the Nachbestromung takes place depending on a print size. One or several parameters of the Nachbestromung become dependent on the print size, especially the Rail pressure of a common rail system specified.

The Invention is also by a control device of the type mentioned solved by that the controller Means of implementation the method according to the invention having.

With it is the control unit according to the invention consequently possible to control a solenoid valve by means of the Nachbestromung invention and thus an increased Metering accuracy and especially very short distances between to achieve individual Hauptbestromungen and yet a high metering accuracy observed.

From Of particular importance is the realization of this invention in the form a computer program. The computer program is on one Computing device, in particular on a control unit for the Control of a solenoid valve, executable and to perform the inventive method programmed. The invention is thus the computer program realized, so that this computer program in the same way the Invention represents how the method for its execution of Computer is suitable.

The Computer program is preferably stored on a memory element. A memory element can in particular be a random access memory, a read-only memory or be a flash memory. A memory element can in particular also a floppy disk, a compact disc (CD), a digital versatile disc (DVD) and / or at least one of a component of the control unit assigned Be memory area.

drawings

Further applications and advantages of the invention will become apparent from the following description of exemplary embodiments, which are shown in the drawing. Show it:

1 a schematic representation of a solenoid valve as part of a fuel injector;

2 a schematic representation of the Ankerplattenhubs as a function of time according to a known current profile and a current profile according to the invention and

3 a schematic representation of a current profile with remote Nachbestromung and a representation of Ankerplattenhubs.

Description of the embodiments

In 1 is a solenoid valve 1 For example, shown as part of a fuel injector, not shown. The solenoid valve 1 has a valve body 2 in which an anchor room 3 is trained. In the anchor room 3 are an anchor 4 and an anchor plate 5 arranged. In the anchor room 3 are also an anchor spring 6 and a valve spring 7 arranged. The solenoid valve 1 also has a magnetic coil 8th on that the valve spring 7 encloses annularly.

A valve ball 9 sits in a at an upper end of a drain throttle 10 trained valve seat. The outlet throttle 10 opens into a valve control room 11 ,

Will be to the solenoid 8th An electrical current is passed through electrical lines, not shown, so-called energization of the solenoid valve takes place. This will be in the solenoid 8th built up a magnetic field, which is a movement of the armature 4 upwards against the force of the valve spring 7 causes.

Is the solenoid valve 1 Part of a fuel injector, so causes a valve in the control room 11 prevailing pressure of a fuel located there a movement of the valve ball 9 out of the valve seat when the solenoid valve 1 is driven with the current profile corresponding to a pilot injection or a main injection.

At a transition from an open state of the solenoid valve 1 in a closed state, as in 1 is shown, it comes to a so-called Überhubprellen the anchor plate 5 because the anchor 4 in his movement, by the valve spring 7 is caused to stop when the valve ball 9 pressed into the valve seat. Such an overtravel bounce is thus part of the hitherto known as anchor bounce oscillations of elements of the anchor group.

To the on the valve ball 9 and to limit the valve seat acting force, the anchor group is formed such that the anchor plate 5 independent of the anchor 4 can move further down, against the force of the armature spring 6 , This movement can take place at most up to a design-related predetermined overstroke. At the latest there, the movement of the anchor plate is reversed 5 around. By the force of the anchor spring 6 acted upon, the anchor plate moves 5 back up until it stops at the top 13 strikes. This is however with the anchor 4 positively connected, so that the overtravel bouncing of the anchor plate 5 an impingement of the anchor 4 due to the kinetic energy of the anchor plate 5 causes. Subsequently, the anchor plate moves 5 back down. This creates a vibration of both the anchor plate 5 as well as the anchor 4 , which is called anchor bounce.

In 2 are the time course of energization of a solenoid valve 1 represented according to a first current profile A and the course B of the Ankerplattenhubs occurring in this case. In 2 Furthermore, a second current profile C encompassing a subsequent energization and the course D of the armature plate stroke occurring in this case are shown by means of dashed lines.

The current profiles A and C each comprise a Hauptbestromung, in 2 shown as a solid line provided with the name A. The current profile C additionally includes a Nachbestromung, in 2 shown as a dashed line provided with the name C.

At a time T1, a main energization takes place according to a known current profile. In this case, the solenoid valve is initially controlled by means of an opening current from the time T1. The opening flow has a particularly steep flank and rises to a current of nearly 20 amps at time T2. From time T2, the solenoid valve 1 controlled by a starting current.

At a time T3, the anchor plate have 5 and the anchor 4 due to the magnetic field maximum in the direction of the magnetic coil 8th moves, leaving the solenoid valve 1 is fully open. The solenoid valve 1 is initially controlled from about this time with a holding current, which is finally switched off, so that the current drops to a value of about 0 amps until a time T4.

Switching off the main power supply according to the current profiles A and C causes the armature to close 4 and thus a movement of the anchor plate 5 as they are in 2 between times T3 and T6 is shown.

According to the known current profile A has the anchor plate 5 at the time T8 - as shown in the course B - reaches the maximum overstroke and begins to swing back, ie in the direction of the solenoid 8th , The anchor plate 5 then hits the top stop 13 at. This can be a movement of the anchor 4 towards the solenoid 8th result have, resulting in even a momentary opening of the solenoid valve 1 can lead. Then the anchor plate moves 5 according to the course B again in the direction of the lower stop 12 ,

At a time T9, the force of the armature spring 6 greater than the remaining momentum of the anchor plate 5 , so again an upward movement of the anchor plate 5 he follows. These movements of the anchor plate 5 as shown in the course B are referred to as Überhubprellen.

This in 2 illustrated current profile C provides a Nachbestromung. For this purpose, at a time T5 of a control unit, the solenoid valve according to the current profile C is controlled such that the wake reaches a value of about 6 amps. This Nachbestromung does not immediately follow the Hauptbestromung, it is therefore a remote Nachbestromung. At a time T7 the Nachbestromung is turned off.

As from the course D of Ankerplattenhubs from the time T6 visible is, is the over-bounce as a result of Nachbestromung invention clearly subdued compared to the over-bounce as shown in the course B. A renewed energization could by means of the Nachbestromung invention already initiated at the end of the Nachbestromung with high metering accuracy be there no over-bounce is present, which would affect the metering accuracy such as This is the case for example at a time T8 according to the current profile A. would.

In 3 is a highly schematic representation of a current profile with a remote Nachbestromung by the solid line. With a dashed line is in 3 the associated Ankerplattenhub, or from the anchor plate 5 shown as a function of time traveled.

Between the times T20 and T21 becomes a Hauptbestromung of the solenoid valve 1 performed so that a controlled by a controller current through the electromagnet 8th flows.

Between the time T21 and a time T22 there is no energization of the solenoid valve 1 ,

From the time T22 there is a remote Nachbestromung. At a time T23, the controller causes the switching off of the Nachbestromung, so that from a time T24 no more current through the electromagnet 8th flows.

In at a time T25 we again initiated a main energization, which is also followed by a remote Nachbestromung.

The remote Nachbestromung has the opposite of a Hauptbestromung immediately following Nachbestromung the advantage that the remote Nachbestromung no influence on the closing of the solenoid valve 1 takes place because the remote Nachbestromung is performed only when the solenoid valve 1 already closed. This makes it possible, for example, between the times T20 and T21 a previous current profile can continue to be used unchanged and the increased metering accuracy is achieved by downstream of the remote Nachbestromung.

If, in comparison, a Nachbestromung attached directly to the main current, the Nachbestromung follows almost directly the main current, as in 2 is shown, the closing of the solenoid valve 1 influenced, since during the Nachbestromung an attenuated magnetic field by the electromagnet 8th is maintained, the force of the valve spring 7 counteracts. This means that it may be advantageous in an immediately following Nachbestromung to take into account this effect of the delayed closing of the solenoid valve in the vote of Hauptbefromung with. However, the immediately following Nachbestromung has the advantage that a damping of the oscillation of the anchor plate 5 is reached faster, so that a current can already be done earlier. By means of an immediately following Nachbestromung can also be achieved in particular that the anchor plate 5 does not go through the full overstroke and in particular not to the lower stop 12 strikes, but experiences such a strong damping that the kinetic energy of the anchor plate 5 already compensated by the energy of the magnetic field generated by the Nachbestromung.

at a particularly advantageous embodiment is provided that the Nachbestromung dependent is selected from the operating condition of the internal combustion engine. Especially advantageous Here, if the current value and / or the duration of the braking current and / or the distance between the braking current and other currents depends on a fuel pressure variable specified becomes. In this case, as the fuel pressure variable in particular the rail pressure a common rail system or another print size that is comparable to the rail pressure used.

This is advantageous because different at different fuel pressures personnel to act on the individual elements. So the bounce is at high pressures pronounced.

Claims (12)

Method for controlling a solenoid valve ( 1 ), whereby the solenoid valve ( 1 ) has an anchor group comprising at least one element, characterized in that a Nachbestromung the solenoid valve ( 1 ), wherein the Nachbestromung causes a damping of a vibration of at least one element of the anchor group. A method according to claim 1, characterized in that the at least one element is an anchor plate ( 5 ). Method according to claim 2, characterized in that the anchor plate ( 5 ) has an overstroke and the overtravel of the anchor plate ( 5 ) is greater than 10 microns. Method according to one of the preceding claims, characterized in that the control of the solenoid valve ( 1 ) comprises at least one Hauptbestromung and the solenoid valve is subsequently controlled by the Nachbestromung at least approximately directly to the Hauptbestromung. Method according to one of the preceding claims, characterized in that the control of the solenoid valve ( 1 ) a main current carrying a holding current comprises the solenoid valve ( 1 ) is subsequently driven by the Nachbestromung at least approximately directly to the holding current. Method according to one of the preceding claims, characterized in that the control of the solenoid valve ( 1 ) comprises at least one main energizing and the solenoid valve ( 1 ) is driven by the Nachbestromung after a predetermined, the main energization following period of time. Method according to one of the preceding claims, characterized characterized in that a Hauptbestromung approximately directly to the Nachbestromung follows. Method according to one of the preceding claims, wherein the solenoid valve ( 1 ) an anchor plate ( 5 ) and a lower stop ( 12 ), characterized in that by the Nachbestromung an impact of the anchor plate ( 5 ) on the lower stop ( 12 ) is prevented. Method according to one of the preceding claims, characterized characterized in that the Nachbestromung takes place depending on a print size. Control device for controlling a solenoid valve ( 1 ), characterized in that the control device comprises means for carrying out a method according to one of claims 1 to 8. Computer program that is used in a computing device, in particular in a control device for controlling a solenoid valve ( 1 ), characterized in that the computer program is programmed to perform a method according to any one of claims 1 to 8 when it runs on the computing device. Computer program according to claim 11, characterized that the computer program is stored on a memory element, the storage element being a floppy disk, compact disk (CD), digital Versatile disk (DVD), and / or at least one at least one component of the computing device allocated memory area is formed.