FR2619598A1 - METHOD FOR CONTROLLING THE INJECTION PHASE OF AN ELECTRONIC FUEL INJECTION - Google Patents

Abstract

1. Method for controlling the injection phase of electronic fuel injection. 2.1 Processes of this kind are implemented for the control of internal combustion engines, for each cylinder of the engine 1 being provided an injector valve 3 which ensures the injection during the opening phase of the intake valves. 2.2 The well-known synchronization devices have end points of the injection phase rigidly associated with the position of the crankshaft, which does not represent a temporal optimum in the event of variation in the operating states of the internal combustion engine 1. The new method therefore provides that the opening phase of the various intake valves is determined from the signals of a detector 5 of the position of the engine shaft; that for the determined opening phase, an end point of the injection phase is determined as a function of other parameters of the engine; and that the beginning of the injection phase is fixed at the duration of the injection pulse before the determined end point. 2.3 This has allowed an optimization of the decontamination of the exhaust gases and a greater economy of the operation of the engine so that the operation of the engine is possible on a road vehicle.

Description

Method for controlling the injection phase of an injection of

  The invention relates to a method for controlling the injection phase of an electronic fuel injection

  in the air intake tube of an internal combustion engine

  dull, compared to the opening phase of intake valves

  which an injection valve is respectively associated with

electromagnetic trice.

  German patent DE-OS-2,331,266 discloses a device

  synchronizing circuit for injecting fuel into air suction tubes respectively leading to the different cylinders, a control circuit being set by means of marking and erasure pulses on the sequence

  cycles depending on the rotational speed of the motor to achieve

  fuel injection at the right time during the race

  in the cylinder respectively provided for the

Lumage.

  Experience shows, however, that synchronization

  optimum fuel injection must be achieved.

  according to the specifications of the internal combustion engine

  dull, for example the position of the injector valves by

  intake valves and other parameters of the

  in such a way that it can be admitted that the well-known device has the disadvantage that the internal combustion engine is not fully effective as regards the output power, the emission of harmful products

  and fuel consumption since the temporary phase

  porelle is not optimal because of the maintenance of the end of

  fuel injection for the predetermined crankshaft angle

mine.

  The object of the present invention is to indicate a

  assigned for the control of the injection phase which allows

  dyeing, regardless of the service characteristics of the internal combustion engine and the engine parameters, an optimum for the reduction of pollutants in

exhaust and efficiency.

  According to the invention, this object is achieved by the fact that the opening phase of the various intake valves is determined from the signals of a position sensor of the motor shaft; only for the determined opening phase,

  an end point of the injection phase is determined

  other engine parameters; and that the beginning of

  the injection phase is fixed at the duration of the injection pulse.

  jection before the determined end point. Features

  advantageous features of the process are indicated in the

of the subclaims.

  The description that follows, next to the drawings

  annexed by way of non-limiting examples, will

  understand how the invention can be put into practice.

  FIG. 1 represents a schematic view of a

  internal combustion engine; FIG. 2 represents a diagram with phases of the intake and exhaust opening indicated on the axis of the positions of the crankshaft determined from the

  signals from the detector, as well as with ignition and injection.

  The internal combustion engine represented in the

  Fig. 1 comprises an air suction tube 2 with respective

  a branch line leading to each of the cylinders, in

  which is inserted each time an electronic injector valve

  tromagnetic 3 which responds to signals from a communications device

electronic call 4.

  The control apparatus 4 is connected by lines to signal transmitters for various motor parameters and determines the duration of the injection pulse necessary for satisfactory motor operation. For the implementation of the method according to the invention, the internal combustion engine 1 necessarily comprises a position sensor of the motor shaft 5 which is constituted, for example, by a split disc 6 mounted on the motor shaft and a detector

  Hall 7. On this disc, a slot is associated with each

  lindre, a larger slot being associated with a reference cylinder so that a signal different from other signals

  is delivered by the position detector 5.

  Fig. 2 shows, on the axis of the angles 8, posi-

  9 of the motor shaft sensor, the signal 9 for two rotations of the crankshaft having a larger value than the

  signal for 1/2 rotation (for a 4-cylinder engine). The ap-

  the same order 4 must deduce the order of the pulses

  Injection & Transfer to Inlet Valves 3.

  Below the axis of the angles 8 are represented the phases of the intake-exhaust openings and the ignition and injection Il, 12, 13 for the first and

  second cylinder of the engine & 4 cylinders, the ignition phase

  mage 13 including the ignition control range and the injection phase.

  14 is indicated for the full load regime and includes the shorter phases corresponding to idling and partial load operation (shown as hatched). The interval between the end point of the injection phase 14 and the end point of the phase

  opening of the intake valves 11 is variable depending on

  engine parameters, for example the speed of the engine,

  rotation of the motor, the amount of air drawn in, the temperature

  motor, etc ... and advantageously stored in a network of characteristics 15 of the device

electronic control 4.

  Principle of operation The motor 1 operates, for example, at a partial load point which is defined by a determined air flow rate and a fixed rotational speed. The duration of the injection pulse is determined from the engine parameter signals usually delivered by the control unit

  and transmitted to the injector valves 3. The process according to the

  vention now controls the injection phase, referred to

  the opening phase of the engine intake valves

  internal combustion so that the opening phase of the various intake valves is determined from the signals of the position sensor of the motor shaft 5; that for the determined opening phase, an end point of the

  injection phase has come out of the memory of networks of

  characteristics of the control apparatus 4 as a function of the rotational speed, the air flow rate and / or the engine temperature; and that the beginning of the injection phase is set to the duration of the injection pulse ahead of the determined end point. In this way, the injection pulse arrives early enough to the injector valve 3 for the valve

  admission is still open after the end of the injection.

  tion. The end point of the injection was then fixed in such a way that no more fuel is found in the suction pipe 2, that is to say upstream of the intake valves when the intake valve closes, which has been tested and

  determined by tests. This offers in relation to a provision

  tif well known the advantage that the internal combustion engine

  can operate under favorable conditions without impulse

  return and respectively without reflux of particles of

  fuel to other cylinders. We obtain a good distribution

  mixture on the cylinders, which allows, in the

  seems to be preparing the combustion mixture with

  less fuel. In addition, benefits have been achieved with respect to the decontamination of

  exhaust gas through non-polluting combustion.

  For the unsteady state of operation,

  that is during the period of time during which the values of the air flow rate or the speed of rotation change as a result of the variation of the position of a choke reducing the air flow rate, it is advantageous that the duration of the required injection pulse determined in the control device 4 is compared with the time remaining to the end point and it is decided for which the injector valves the beginning of the injection phase must be taken out the duration of the injection pulse before the end point. This measurement makes it possible to quickly adapt the duration of the injection pulse and the position of the injection phase to

engine state variations.

  The position signals of the motor shaft are transmitted in the form of digitized values, the value of the signal for the recognition of the cylinder being larger.

than that of the other signals.

Claims (5)

  1. - Method for controlling the injection phase   injection of electronic fuel into the vacuum tube   air intake (2) of an internal combustion engine (1) relative to the opening phase of intake valves with which an electromagnetic injector valve (3) is respectively associated characterized by the fact that the the opening phase of the various intake valves is determined from the signals of a sensor (5) of the position of the motor shaft; Ir: for the determined opening phase, an end point of the   Injection phase is determined according to other para-   engine meters; and that the beginning of the injection phase   is fixed to the duration of the injection pulse before the determined end point.   2. - Method according to claim 1, characterized   in that the duration of the injection pulse required de-   completed electronically is compared with the remaining time   until the end point and that it is decided to inject   trice (3) for which the beginning of the injection phase   2 .. is defined so that it precedes the end point of the duration - of the injection pulse.   3. - Method according to one of claims 1 or 2,   characterized in that end points of the injection phase   are provided by a memory of networks of characteris-   ticks addressed with signals from an engine tachometer,   a measure of the amount of air and / or temperature of the tor.   4. - Process according to any one of the claims   1 to 3, characterized in that the position signal of   the motor shaft is output as digitized size.   5. - Process according to claim 4, characterized in that, for the recognition of the injector valves (3), the intake valves and the cylinders respectively, there is provided a position signal of the engine shaft which differs   of the usual digitized size.