FR2763998A1 - METHOD AND DEVICE FOR CONTROLLING AN INTERNAL COMBUSTION ENGINE - Google Patents

Abstract

Method and device for controlling an internal combustion engine, in particular an uncontrolled ignition engine. From a signal characterizing the position of a shaft, control quantities are predetermined for controlling the internal combustion engine. An individual correction is made per cylinder and / or depending on the operating parameter and which characterizes a preferred position of a shaft.

Description

State of the art: The present invention relates to a method and a

  control device for an internal combustion engine no-

  especially of an uncontrolled ignition engine, according to which the control quantities are predetermined for controlling and / or regulating the internal combustion engine on the basis of a signal

  characterizing the preferential position of a tree.

  Such a process and such a device are known

  according to document DE-OS 43 39 957. This document describes a pro-

  assigned that the difference between a pulse is determined

  reference point and the top dead center of the crankshaft and it is used to control the internal combustion engine. The

  process described in this document only compensates for the tolerances

  rancid repercussions on all the cylinders. More because

  torsional oscillations of the crankshaft, we have different

  between the effective top dead center and the theoretical top dead center. These differences are not offset by

  the installation according to the state of the art.

Advantages of the invention:

  The object of the present invention is to remedy these drawbacks

  nients and to this end relates to a method of the type defined above, characterized in that a correction is made to the

  signal according to an operating and / or individual parameter-

  by cylinders, to characterize the preferred position

tielle of a tree.

  The invention also relates to a device for implementing such a method, characterized in that it

  includes means which correct the signal depending on the pa-

  operating and / or individual ram meter per cylinder, and

  characterizing the preferential position of a tree.

  The method and the device according to the invention of-

  have the advantage of also compensating for effects from

  torsional oscillations. To do this, we correct the large

  deur which indicates the top dead center, individually

  per cylinder and / or according to the operating parameters.

  According to other advantageous characteristics of the invention: * correction is made as a function of at least the load and / or the

  rotation speed of the internal combustion engine.

  * correction values are saved in a field of

  characteristics to perform the correction.

  * the preferred position of the tree is neutral

top of a cylinder.

  Drawings: The present invention will be described below in more detail using an embodiment shown schematically in the accompanying drawings, in which: - Figure i is a very schematic view of the control installation d '' an internal combustion engine,

  - Figure 2 is a detailed view of the com-

  control of the internal combustion engine,

  - Figure 3 is a block diagram of the cor-

  rection according to the invention of the top dead center,

  - Figure 4 shows different signals in operation

tion of time.

  Description of the exemplary embodiments:

  The method according to the invention will be described below by way of example in its application to a diesel engine. The method described is however not limited to its application to diesel engines; it can also be transposed to other types of internal combustion engines. In this case, the corresponding elements will have to be modified. This is how, for example in the case of an internal combustion engine,

  with controlled ignition, the instant of ignition has a significant

  analogous to that of the start of the injection of a

  internal combustion with uncontrolled ignition.

  According to FIG. 1, the reference 100 designates an internal combustion engine, in particular a diesel engine. The crankshaft not shown of the internal combustion engine carries a starter ring gear 110. This ring is detected by an inductive sensor 120. The inductive sensor supplies a control device, in particular a control device.

  control with electronic data processing 130 in it

seeing signals.

  The internal combustion engine receives fuel

  metered by a fuel pump 140. The fuel pump

  The rant is driven by a drive axle carrying an incremental wheel 150. The increments of the incremental wheel 150 are detected by an increment sensor 160. The increment sensor 160 then provides an appropriate signal to

the EDC 130 control unit.

  The pump drive shaft 170 is itself

  even driven by the camshaft of the internal combustion engine

  dull. The camshaft or the pump drive shaft and the crankshaft are connected by a drive means

  and in particular a toothed belt or a chain.

  The pump drive shaft is moved relative to

  the camshaft 170 an injection adjustment member 190.

  The embodiment shown, corresponds to a distributor pump controlled by a solenoid valve. The method according to the invention can also be used in other dosing systems such as for example pump and nozzle systems or common rail systems. In this case, the role of the injection adjustment device is provided by a solenoid valve. The EDC control unit 130 acts on the fuel pump and the injection control device 190 by supplying them with control signals from the signals

  that he himself receives different sensors detecting diff-

  different operating parameters.

  This installation mainly works as follows: Starting from the different sensor signals,

  the EDC 130 control unit calculates a value of the quan-

  tity of fuel to be injected and the start of injection. From these values, the control unit determines

  control pulses for controlling the re-

  injection timing 190 fixing the start of the injection. In or-

  tre, the control apparatus 130 supplies control pulses for controlling an adjustment member used for adjusting

  a metering member of the fuel pump 140.

  The inductive sensor 120 detects the teeth of the

  starter ring 110 of the starter. The control unit re-

  thus knows the position of the crankshaft. The top dead center OT of the crankshaft is a preferred position. For optimum fuel dosage, the start of the injection must

  be linked to the top dead center of the crankshaft. For this reason

  the toothed ring of the starter has a mark which the inductive sensor recognizes. The pulse generated from this reference is usually called reference pulse R. From the torsional oscillations of the crankshaft and / or the camshaft, there is a difference between the position of the reference pulse R and the actual top dead center OT of the crankshaft. For a precise metering of the fuel, this difference must be taken into account. Therefore, it is planned to determine correction values, save them in a

  memory and take into account when calculating the com-

  order. These correction values are saved in the

  memory according to the operating parameters and for each

that cylinder individually.

  Figure 2 shows in detail

  the control unit 130. The elements already described

  pos of Figure 1 have the same references. The device

  130 processes the output signals of the internal sensor

  ductive 120 also called rotational speed sensor; in the present exemplary embodiment, the sensor detects the teeth of the starter ring gear. In addition, the controller 130 processes the output signal from an accelerator pedal position sensor 225 providing

  an FP signal which corresponds to the driver's wishes.

  A sensor 230 provides the reference pulse R

  or an OT signal indicating the top dead center of a cylinder.

  In the exemplary embodiment shown, this signal is provided

  nor by a segment wheel 231. The segment wheel 231 is

  preferably mounted on the crankshaft or camshaft.

  It is also possible to use an incremental wheel comprising

  a predetermined benchmark and / or an interval or several in-

  tervalles which will be interpreted as a referral impulse

rence by sensor 230.

  An injection control 215 supplies the control signals to the fuel pump 240; these signals set the start of the injection, the end of the injection and / or the quantity to be injected. Thus, the injection control 215 processes not only other signals and in particular the signal N of the speed of rotation (speed) and the signal FP of the driver's wish as well as the output signal of a correction stage 235 Correction stage 235 processes the pulse

  of reference R and the output signal of a character field

  240 receiving an input signal, the rotation speed N, a signal concerning the quantity of fuel QK

  to inject and / or the FP driver wish signal.

  This installation works as follows:

  boasts: the injection is controlled by command 215 according to the various operating parameters such as

  for example the speed of rotation N and the wish of the conduct-

  FP teacher. Based on these quantities or, if necessary, other quantities or operating parameters such as for example

  the temperature, the injection control 215 calculates the quantity

  tity of KQ fuel to be injected as well as the start of injection. The start of the injection is generally provided

  as angular position, by the top dead center OT.

  This is why the reference pulse R takes on a very great importance for the exact control of the injection. Usually, the crankshaft or the camshaft has one or two marks interpreted as reference pulses R. Starting from the reference pulse R, an OTi signal is defined for each cylinder which indicates the neutral point

  top of the respective cylinder. We add it for each cylinder

  dre a fixed value at the angular position for the reference pulse R. Starting from a reference pulse R, we thus obtain the OTi pulses characterizing the points

  dead high from different cylinders.

  It is particularly advantageous for the sensor 230 to indicate a reference pulse and thus an OTi signal

  giving the top dead center for each cylinder.

  These pulses are shown in Figure 4.

  Depending on the angular position of the crankshaft given in degrees of angle, two vertical lines indicate each time

  a reference pulse R. The two reference pulses

  rence R are spaced by a crankshaft angle of 1800. In addition, the predictable top dead centers OTi defined from

  preferably pulses are identified by green lines

  tical lines. These predictable high dead centers of the different cylinders bear the references OT1, OT3, OT4

or OT2.

  From the tolerances and the oscillations of

  crankshaft twist, the effective top dead center of the crankshaft

  brequin is in the positions indicated by dotted lines

  terrompus, bearing the references OTi ', OT3', OT4 ', OT2'.

  The deviations between the predictable OTi positions and the OTi 'high effective dead centers each time bear the reference AOTi. These deviations between the effective top dead center and the predictable top dead center are stored in the characteristics field 214. According to the invention, these values are stored for each cylinder, as a function of the operating parameters. It is particularly advantageous that these values are stored as a function of the speed of rotation N and the state

  load of the internal combustion engine, because these two large

  These have the greatest influence on torsional oscillations. As a load signal, you can use on the one hand

  the quantity of fuel injected QK and on the other hand the

  general FP speed wish. The car quantity signal

  fuel injection QK available in the control unit

  is supplied by the injection control 215.

  Starting from these magnitudes, on the character field

  240, we extract for each cylinder the value of

  AOTi correction. With this value, we correct the pre-

  visible for OTi. The value thus corrected for top dead center is supplied by the injection control 215 to the control of the internal combustion engine. Correction 235 is shown in detail in FIG. 3. The elements already described in FIGS. 2 and 1 are given the same references. Characteristic field 240 contains the following AOTi correction values

  the quantity of QK fuel to be injected, the speed of rotation N and the cylinder into which it is injected. With these values at the combination point 220, the predicted value 10 of the top dead center OTi is corrected.

  Preferably, an additive combination of the two signals is made. The output signal of the combination point constitutes the corrected value of the top dead center OTi '. This value is applied to the injection command 215.15

Claims (5)

R E V E N D I C A T IONS   1) Method of controlling an internal combustion engine no-   as with an uncontrolled ignition engine, according to which the control quantities are predetermined for controlling and / or regulating the internal combustion engine on the basis of a signal characterizing the preferred position of a shaft, characterized in that a correction of the signal is carried out according to a parameter of   operation and / or individually by cylinders, for   reactivate the preferential position of a tree.   2) Method according to claim 1, characterized in that   at least the charge and / or the speed are corrected as a function   rotation of the internal combustion engine.   3) Method according to any one of claims 1 and 2, characterized in that   correction values are saved in a field of   to perform the correction.   4) Method according to any one of the preceding claims. teeth, characterized in that   the preferred position of the shaft is the top dead center of a cylinder.    ) Method according to one of the preceding claims, characterized in that   control quantities control and / or regulate   fuel injection, especially the instant of injection.   6) Device for controlling an internal combustion engine, in particular an internal combustion engine with non-ignition   controlled, using a signal characterizing a pre-   of a shaft for predetermining the control quantities for controlling the internal combustion engine, characterized in that it comprises means which correct the signal depending on the operating parameter and / or individual by cylinders,   and characterizing the preferential position of a tree.