WO2010069779A1

WO2010069779A1 - Method for determining an armature movement of an injection valve

Info

Publication number: WO2010069779A1
Application number: PCT/EP2009/066357
Authority: WO
Inventors: Klaus Joos; Helerson Kemmer; Holger Rapp; Anh-Tuan Hoang
Original assignee: Robert Bosch Gmbh
Priority date: 2008-12-19
Filing date: 2009-12-03
Publication date: 2010-06-24
Also published as: DE102008055008B4; CN102257262A; DE102008055008A1; CN102257262B

Abstract

In an internal combustion engine, the fuel enters a combustion space by means of an injection valve comprising an electromagnetic activation device. The invention relates to a registered first electrical value (n) of a magnetic circuit of the electromagnetic activation device is supplied to an observation member (56) that reproduces the magnetic circuit without considering the effects of an armature movement on the electrical values of the magnetic circuit, wherein the observation member (56) determines an observed second electrical value (ib) of the magnetic circuit, the determined second electrical value is compared to a registered second electrical value (i) and the comparison result (dib) is used to determine a value characterizing the armature movement.

Description

description

title

METHOD FOR DETERMINING ANCHOR MOVEMENT

AN INJECTION VALVE

State of the art

The invention relates to a method for operating an internal combustion engine according to the preamble of claim 1. The invention further relates to a computer program, an electrical storage medium and a control and / or regulating device.

From the market, internal combustion engines are known in which gasoline from injectors is injected directly into respective combustion chambers. Such injection valves have a valve needle actuated by an electromagnetic actuator. Disclosure of the invention

The object of the present invention is to provide a method which makes it possible to optimize the fuel injection.

This object is achieved by a method having the features of claim 1. Further solutions are given in the independent claims that relate to a computer program, an electrical storage medium and a control and / or regulating device. advantageous

Further developments of the invention are specified in subclaims. In addition, important features for the invention can be found in the following description and in the drawings. These features may be important for the invention both alone and in different combinations, without being explicitly referred to again. With the aid of the method according to the invention, a variable characterizing the armature movement can be determined.

This in turn makes it possible to influence the valve needle movement, thereby optimizing the injection of the fuel. Ultimately, the invention contributes to reducing the emissions of an internal combustion engine, the

To reduce fuel consumption and reduce combustion noise.

The basis for this is the idea that an electrical variable of the magnetic circuit of the electromagnetic actuator by an observer, ie an estimation method is determined and quite deliberately ignoring the influence of the movement of the armature on the electrical variables of the magnetic circuit. Inevitably, therefore, the electrical quantity determined by the observer member includes an error that can be determined by comparison with the corresponding detected quantity. This error, provoked on the non-consideration of the reaction of the armature movement to the electrical magnitudes of the magnetic circuit, can now be used to quantify this retroactivity and thus permits the determination of a variable characterizing the armature movement.

The method according to the invention thus operates without any additional component and can be realized solely by software. It is therefore extremely inexpensive and possibly even applicable to existing systems.

A concretization of the general inventive idea is that in the

Step b, the difference between the observed second electrical quantity and the detected second electrical variable is formed, and that in step e, the difference is fed to a feedback element, which determines a first electrical correction quantity, which is added to the detected first electrical variable, in such a way that the difference between the observed second electrical quantity and the detected second electrical quantity becomes minimal, the course of the first electrical correction variable is summed up, and a stroke characteristic from the accumulated first electrical correction quantity is determined as a variable characterizing the armature movement.

The deliberately provoked error at the output of the observer member is so via the feedback link to the input of the observer member so that it minimally, at best, to zero. The correction variable output for this purpose from the feedback element can be used directly for determining the stroke course of the armature. Thus, the method according to the invention allows the course of the stroke of the armature and thus of the armature

Hubs of the valve element at least during the opening phase of the valve element exactly replicate, whereby the optimization of the injection is particularly simple. Preferably, the first electrical quantity is a voltage and the second electrical quantity is a current. These electrical variables of the magnetic circuit are available anyway and therefore allow an inexpensive and simple implementation of the method according to the invention.

The feedback element can be a proportional element, a PIL element or a higher-order feedback element. Ultimately, the feedback characteristic between the speed of the armature and the correction quantity is expressed by the feedback element. By choosing a corresponding embodiment of the feedback element can be taken to systematic and constructive differences of an injector on the other consideration, and thus the precision of the method can be increased. In addition, a filtering of interference signals on the detected signals of current and / or voltage can be implicitly realized by an appropriate parameterization of the feedback element.

To increase the precision of the method according to the invention contributes, if in the observer member an eddy current path of the magnetic circuit is modeled. Nevertheless, it is possible in the simplest case, only to emulate the main current path of the magnetic circuit in the observer member, with correspondingly reduced, but in many cases still sufficient precision.

In internal combustion engines having a plurality of injection valves, the inventive method can also be used for equality of the individual fuel injection valves. As a result, the operation of the internal combustion engine is evened out and vibrations are reduced. An example of this is that by means of the determined variables characterizing the armature movement of the individual injection valves, the times of a stroke maximum of the injection valves are equalized. Equality means that these respective events take place at the same crank angle, for example, at a top dead center of the respective cylinder. Alternatively, the periods from the start of a control to the closing of the injectors can be equated, or it can be equated the periods from Hubmaximum to close the injectors. Due to the knowledge of the valve needle movement can be equated with knowledge of additional parameters, such as the fuel pressure, by means of the determined, the armature movements characterizing sizes and the injection quantities of the injectors.

Hereinafter, embodiments of the invention will be explained in more detail with reference to the drawing. Show it:

Figure 1 is a schematic representation of an internal combustion engine having a plurality of electromagnetically actuated injection valves;

FIG. 2 shows an equivalent circuit diagram of a magnetic circuit of an injection valve of FIG

1 ;

Figure 3 is a block diagram of the magnetic circuit of Figure 2;

Figure 4 is a block diagram of a method for determining a correction quantity using an observer member corresponding to the magnetic circuit of Figure 3;

FIG. 5 shows two diagrams in which the profile of a drive current and the stroke characteristics of three different emission valves are shown over time, without equality;

Figure 6 shows two diagrams, similar to Figure 5, with equality of the period from the start of a drive to close the injectors; FIG. 7 shows two diagrams similar to FIG. 5 with an equalization of the times of the stroke maxima; and

Figure 8 shows two diagrams similar to Figure 5 with an equality of the periods from Hubmaximum to close the injectors.

In FIG. 1, an internal combustion engine bears the reference numeral 10 as a whole. It comprises a tank 12, from which a delivery system 14 delivers fuel into a common rail 16. To this a plurality of electromagnetically actuated Einspritzve- valves 18a to 18d are connected, which the fuel directly in them

Inject combustion chambers 20a to 2Od. The operation of the internal combustion engine 10 is controlled or regulated by a control and regulating device 22 which, among other things, also controls the injection valves 18a to 18d.

An equivalent circuit diagram of a simplified magnetic circuit 44 of the electromagnetic actuator of the valves 18a-18d is shown in FIG. With 46 is the main current path and 48 denotes the eddy current path. In a simplified embodiment, not shown, an equivalent circuit diagram can be adopted, which does not imitate the vortex Ström pf ad. A corresponding block diagram of the magnetic circuit 44 is shown in FIG. The parameters of the block diagram result from those of the equivalent circuit of Figure 2 by normalization of current and voltage. The eddy current path is reproduced in the equivalent circuit diagram of FIG. 2 by the components Rw * and L _s -, in the block diagram of FIG. 3 by the integrator 50 with the time constant T _s and the proportional element 52 with the gain K _RW in the feedback path.

By means of the substitute or block diagrams shown in FIGS. 2 and 3, the behavior of the magnetic circuit 44 is reproduced with good accuracy when the magnetic armature of the electromagnetic actuator is stationary. The reaction of the movement of the magnet armature to current and / or voltage is intentionally not taken into account in the path simulation of FIGS. 2 and 3. The presence of this reaction in the actual operation of the injection valves 18a to 18d represents the essential difference between the track simulations shown in FIGS. 2 and 3 and the real one

Magnetic circuit of the injection valves 18a to 18d. This difference is how will be explained below, used to determine a characterizing the movement of the armature size.

4, the real magnetic circuit of an injection valve 18 is designated in FIG. 4 by applying a voltage u, which can also be referred to as the detected first electrical variable of the real magnetic circuit 54, This results in a drive current i, which can be referred to as detected second electrical variable of the real magnetic circuit 54. The drive voltage u is supplied to an observer member 56 which corresponds to the simplified magnetic circuit 44 according to the block diagram of FIG. Output variable of the observer member 56 is an observed coil current i _b , which can be referred to as observed second electrical variable of the theoretical magnetic circuit 44 so far. 58, the difference di _b between the observed coil current i _b and the detected coil current i is formed and fed to a feedback element 60 as an input variable. This feedback element 60 may be, for example, a proportional element, a PIL element or else a higher-order feedback element and / or more complex structure. In this case, by the parameterization of the feedback element 60, the transmission behavior between the speed of the magnet armature 30 and an output variable U _corr

Feedback element 60 expressed and so far also influenced. By means of an appropriate parameterization, filtering of interference signals on the detected signals of the coil current i and / or the voltage u can thus be implemented implicitly.

The output u _kOrr , which can also be referred to as the first electrical correction _variable , is now added to the input of the observer member 56 in 62 additive. In this way, the observed coil current i _b is tracked to the measured coil current i, ie the difference di _b is minimized or made zero.

Since the difference between the real magnetic circuit 54 and the simplified magnetic circuit 44 in the observer member 56 in the lack of retroactivity of the movement of the armature, now forms the first electrical correction _quantity U _corr exactly this reaction, this reaction has a proportionality to the speed of the armature. Therefore, through a tegration of the first electrical correction _quantity u _kDrr the course of the movement of the armature can be reconstructed. Since the stroke of a valve needle of the injection valves 18a-d in the open state, but at least during the closing operation of the valve needle to impinge on a valve seat is equal to that of the armature, can be determined with the above-presented method, the course of the stroke of the valve needle. However, if the stroke characteristics of the valve needles of the individual injection valves 18a to 18d are known, an equalization of certain parameters of the injection valves 18a to 18d is possible by adjusting the corresponding activation times. This will be explained below with reference to FIGS. 5 to 8:

In FIG. 5, a drive current i for the injection valves 18a to 18c is plotted over time in the upper diagram. This drive current i is identical for all three injection valves 18a to 18c, the corresponding curve is designated 64 in FIG. In the lower diagram of FIG. 6, the lift profiles of the three injection valves 18a to 18c resulting from the drive current are plotted, which leads to corresponding curves 66a to 66c. The curve 66a of the injector 18a may be referred to as a base curve for normal behavior. The curve 66b of the injection valve 18b shows that this injection valve 18b has a so-called reduced opening dead time. The curve 66c of the injection valve 18c shows that this injection valve 18c has a reduced opening dead time and additionally an increased opening speed. It can be seen immediately that without equality measures, different end times of the fuel injection and different injection quantities result.

As a result of the fact that the actual lifting characteristics of the valve needles of the injection valves 18a to 18d are known by the method explained above in connection with FIG. 4, an equalization of certain parameters can now take place. As can be seen from FIG. 6, for example, by changing the on-control current (curves 64a to 64c) in the upper diagram of FIG. 6, the periods from the beginning of the activation to the closing of all the injection valves can be set equal. These periods are designated 68 in FIG.

As an alternative to this, as can be seen from FIG. 7, the times of a maximum lift are identified, which are designated by 70 in FIG. 7 in the lower diagram. Again alternatively, as shown in FIG. 8, the closing times, ie the periods from the stroke maximum to the closing of the injection valves 18a to 18c are equalized. These are designated 72 in FIG.

Claims

claims

1 . Method for operating an internal combustion engine (10), in which the fuel passes into a combustion chamber (20) by means of an injection valve (18) comprising an electromagnetic actuating device, characterized in that a. a detected first electrical quantity of a magnetic circuit of the electromagnetic actuating device is fed to an observer member (56) which simulates the magnetic circuit without taking into account the reaction of an armature movement to electrical magnitudes of the magnetic circuit, the observer member

(56) determines an observed second electrical quantity of the magnetic circuit, b. that the observed second electrical quantity is compared with a detected second electrical quantity, and c. the comparison result is used to determine a variable characterizing the armature movement.

2. The method according to claim 1, characterized in that in step b. the difference between the observed second electrical quantity and the detected second electrical variable is formed, and that in step c. the

Difference is supplied to a feedback element (60) which determines a first electrical correction quantity which is added to the detected first electrical quantity, such that the difference between the observed second electrical quantity and the detected second electrical quantity is minimally minimal History of the first electrical correction variable is added up, and is determined as a armature movement characterizing the size of a stroke profile from the summed first electrical correction variable.

3. The method according to any one of claims 1 or 2, characterized in that the first electrical quantity is a voltage and the second electrical quantity is a current.

4. The method according to any one of claims 2 or 3, characterized in that the feedback element (60) is a proportional element, a P-element or a feedback element of higher order.

5. The method according to any one of the preceding claims, characterized in that in the observer member (56) an eddy current path of the magnetic circuit is modeled.

6. The method according to any one of the preceding claims, characterized in that in an internal combustion engine (10) with a plurality of Einspritzven- valves (18a to 18d) by means of the determined the armature movement characterizing variables, the times of a stroke maximum are equalized.

7. The method according to any one of the preceding claims, characterized in that in an internal combustion engine (10) with multiple Einspritzven- valves (18a to 18d) by means of the determined the armature movements characterizing variables, the periods from the beginning of a control to the closing of the injectors are equalized.

8. The method according to any one of the preceding claims, characterized in that in an internal combustion engine (10) with a plurality of injectors (18a to 18d) by means of the determined the armature movements characterizing variables, the periods are equalized from the maximum stroke to close the injectors.

9. Method according to one of the preceding claims, characterized in that with an internal combustion engine (10) having a plurality of injection valves (18a to 18d) the injection quantities of the injection valves are equalized by means of the determined variables characterizing the armature movements.

10. Computer program, characterized in that it is programmed for use in a method according to one of the preceding claims.

11. Electrical storage medium for a control and / or regulating device

(22) an internal combustion engine (10), characterized in that on it a computer program for use in a method of claims 1 to 9 is stored.

12. control and / or regulating device (22) for an internal combustion engine (10), characterized in that it is programmed for use in a method according to one of claims 1 to 9.