FR2799241A1 - METHOD AND DEVICE FOR DETECTING THE ACTIVE STATE OF A CYLINDER OF A 6 OR 12 CYLINDER INTERNAL COMBUSTION ENGINE - Google Patents

Abstract

Method for detecting the active phase of a cylinder of an internal combustion engine with 6 or 12 cylinders, according to which a sensor coupled to the engine crankshaft supplies a signal (G) by rotation of the crankshaft. This signal is associated with the active phase of the first or fourth or the first or sixth cylinder. A supply pump driven by the crankshaft, in particular the pump of a common rail injection system, is operated in a first operating state with a number of rates corresponding to the number of cylinders, and in a second state of operation with a number of rates corresponding to half the number of cylinders.

Description

The present invention relates to a method of

  detection of the active phase of a cylinder of a

  internal bustion with 6 or 12 cylinders, depending on which a sensor

  coupled to the engine crankshaft provides a signal by rota-

  tion of the crankshaft, this signal being associated with the active phase of the first or fourth or of the first or of the sixth cylinder. The invention also relates to a device for detecting the active phase of a cylinder in an internal combustion engine with 6 or 12 cylinders, comprising a sensor

  coupled to the engine crankshaft and generating a signal by ro-

  tation of the crankshaft, associated with the active phase of the first

  or fourth or first or sixth cylinder.

  In different types of control or regulation

  tion of internal combustion engines, including ignition

  or injection of four-stroke engines, it is necessary

  be able to detect the operating cycle of a certain cy-

  lindre. Usually we have for this a sensor responding to a

  mark carried by the camshaft of the internal combustion engine

  dull. But as the angular precision of such a sensor is not sufficient, for example due to the mechanical play, this sensor signal is generally combined in addition to the signal of a speed sensor responding to benchmarks

  carried by the sound disc rotating with the crankshaft.

  According to document US 3,592,178, an electronic ignition system is known which uses, for the regulation

  of the ignition angle and the detection of the corresponding cylinders

  based on the detection of a work cycle, a pho-

  picnic (or generator disc) rotating in synchronism with the latch of an ignition distributor. A sensor provides continuous information on the angle of rotation; another sensor

detects the cylinder.

  The document WO 97/05971 describes a method of

  tection of the cycle of an internal combustion engine, according to-

  which, by comparing a synchronous signal with the angle of the

  crankshaft and a signal modulated by combustion operations

  tion of the engine, we detect if a certain cylinder is

this moment in its active phase.

  In summary we see that in systems

  usual cylinder detection, two sensors are used.

  For this, we frequently have a speed generator

  tion carried by the crankshaft and another carried by the camshaft of the vehicle engine. In the case of a four engine

  time, two turns of the crankshaft or one turn of the camshaft

  mes correspond to the cycle of a cylinder. In the event of an incident, the association between the cylinders and the crankshaft rotation signal is ensured, using the signal supplied by

the camshaft.

  If however the generator or sensor of rotation of the camshaft is faulty, it is very complicated in current systems, to determine the phase

  active specifies for example the first cylinder. This deter-

  mination of the active phase of the first cylinder is however

  necessary each time the vehicle is restarted, to

  put the continued operation of the system.

  The present invention aims to develop

  simple means for detecting the active phase of a cy-

  linder in current systems, especially the pre-

  1st cylinder of a 6 or 12 cylinder internal combustion engine. To this end, the invention relates to a method of

  type defined above, characterized in that it operates-

  a driven feed pump, coupled to the crankshaft

  quin or in synchronism with the crankshaft, in particular the

  feed pump for a rail injection system

  mune, in a first operating state with a number of cadences corresponding to the number of cylinders, and in a

  second operating state with a number of cadences cor-

  corresponding to half the number of cylinders.

  The invention also relates to a device of the

  type defined above characterized by a feed pump

  tion driven in a manner coupled to the crankshaft or synchro-

  fitted on the crankshaft, in particular a feed pump for a common rail injection system, in a first

  operating state with a corresponding number of rates

  in the number of cylinders, and in a second operating state

  operation with a number of cadences of half the number

of cylinders.

  Particularly in internal combustion engines

  dull equipped with a common rail injection system, it is possible to easily determine the active work phase

  of the first cylinder in a cylinder cycle.

  According to the invention, the fact is used that, for example in common rail systems, it is possible to adjust the

  synchronization between the working cycle of the respective cylinder

  tif and the number of rates of the high pressure pump of a common rail. By selective control of the pump, it is possible simply, by a logical combination of the pressure signal supplied by the pump and the synchronization signal of a door network of a crankshaft sensor, to determine

  the operating cycle of the first cylinder.

  According to a preferred development of the method of the invention, the feed pump is a pump with two pushers operating so as to represent the first active phase with two pushers and the second active phase with a single pushbutton. Such a pump control can by

  example be achieved with an appropriate program using the

  which one can selectively cut half a pump. For example, a connection by a coded connector makes it possible to start the pump or stop it so that, for a

  active phase of the first cylinder, we will have a maximum of

  sion in a pressure chamber associated with one of the pumps

  pes, in particular the distribution bar of a system

common rail injection system.

  Since the establishment of the pressure is not

  mum that for each second cylinder, there are depressions of

  between the different cylinders. So for a flow with

  only one pusher per active phase of the first cylinder, we

  ra maximum pressure and, for the active phase of the

  third cylinder, there will be a minimum pressure, which makes it possible to distinguish the active phase of the first cylinder and that of the

  fourth cylinder. If the pump generates a maximum pressure

  male per cylinder, one could not distinguish the active phase of the first cylinder from that of the fourth cylinder. But

  as for each active phase of the first and fourth cycles

  lindre we will have a corresponding speed sensor signal supplied by the crankshaft (synchronization of the door network), we can unequivocally determine the active state of the first cylinder by a logical combination of

  pressure signal and ro speed sensor signal

  tation of the crankshaft, i.e. if, for a synchro-

  door network, we have maximum pressure, we

  thus positively recognizes the active phase of the

first cylinder.

  The present invention will be described below in more detail with the aid of the accompanying drawing in which

  the only figure is a timing diagram describing how

  ment of the process of the invention in a combustion engine

internal six-cylinder.

  The first line of the figure represents the si-

  gnal G supplied by a generator / sensor responding to a reference

  of a sound disc rotating in synchronism with a city-

  brequin. The signal G thus corresponds to a succession of pulses constituted by a series of distinct pulses triggered at each complete rotation of the phonic disc or

of the crankshaft.

  The second line of the figure shows the pressure produced for two different operating states of the

  pressure produced in a distribution bar of a system

  common rail injection valve. The pressure in the storage injection system is generated by a two-way pump

  pushers, known per se and not requiring a description

  precise. The normal active state of a two-piston pump is characterized by curve 1 in broken lines: during a cycle of a cylinder, i.e. during the passage of a

  active phase of all six cylinders, we have a cor-

  corresponding of maxima and minima of the pressure. The ref-

  rence PMB each time designates the bottom dead center of a cylinder. We see that, by logical combination of the signals G and 1, we cannot distinguish the active state from the first and from the

  fourth cylinder (which are associated with the same angle of vi-

  lebrequin). According to the invention, during the second active state of the pump, a pressure curve corresponding to curve 2 in solid lines is generated. By the implementation of a pump

  with two pushers, when this one uses only one push-

  evening we obtain a pressure curve which gives only a maximum pressure for each second cylinder. For a six-cylinder engine this means that, by an appropriate adjustment of the partial operation of the pump, for the active phase of the first cylinder, there is a maximum pressure and, for the active phase of the fourth cylinder, a minimum pressure. Through

  logical combination of curve 2 with signal G on deter-

  thus unequivocally undermines the active phase of cylinder 1, i.e. it can be distinguished unequivocally from the

active phase of cylinder 4.

  Like the different cylinders of the

  internal bustion are in fixed phase relation, by sim-

  ples angle additions the active phases of each cylinder are determined in the same way, which is known per se and

  will not be described here to simplify the description.

  The method according to the invention is used in particular advantageously if a rotation generator linked to

  the camshaft breaks down. But it is also possible

  ble that the process according to the invention is applied regularly-

  that is to say for the normal operating mode of a

  vehicle that does not have a camshaft sensor.

  For this, after starting the vehicle, it is for example possible to intentionally shut off half of the pump with two pushers to obtain this, only using the

  pressure signal formed and a vile sensor signal

  brequin, an unequivocal angular relationship between the pha-

  its active from different cylinders. After the establishment of this unequivocal association, one can switch the

  pump in operating mode with two pushers.

  The process according to the invention has been set out below.

  above in the case of a six-cycle internal combustion engine

  lindres. The process described applies analogously to an internal combustion engine with twelve cylinders; in this case the method makes it possible to distinguish between the first and sixth cylinders.

Claims (4)

R E V E N D I C A T I O N S   1) Method for detecting the active phase of a cylinder of an internal combustion engine with 6 or 12 cylinders, according to which a sensor coupled to the engine crankshaft supplies a signal (G) by rotation of the crankshaft, this signal being asso - linked to the active phase of the first or fourth or of the first or of the sixth cylinder, characterized in that   a driven feed pump is operated,   cranked to the crankshaft or in synchronism with the crankshaft, in particular the feed pump of a common rail injection system, in a first operating state with a number of rates corresponding to the number of cylinders, and   in a second operating state with a number of   dences corresponding to half the number of cylinders.   2) Method according to claim 1, characterized in that the feed pump is a pump with two pushers and   the pump is operated with two pushers for pre-   feel the first operating state, and with only one   pusher to present the second operating state.   3) Device for detecting the active phase of a cylinder   in a 6 or 12 cylinder internal combustion engine,   bearing a sensor coupled to the engine crankshaft and   rant a signal (G) by rotation of the crankshaft, associated with the active phase of the first or fourth or of the first or sixth cylinder, characterized by   a feed pump coupled to the screw   lebrequin or synchronized on the crankshaft, in particular a   feed pump for a rail injection system   mune, in a first operating state with a number of cadences corresponding to the number of cylinders, and in a second operating state with a number of cadences of half the number of cylinders.   4) Device according to claim 3, characterized in that the feed pump is a pump with two pushers operating optionally with one or two pushers.