FR2697286A1 - Method for monitoring the operation of a coupling device - Google Patents

Abstract

The invention relates to the control of intake or exhaust valves. The valve is actuated by two members which can be coupled by a coupling device and driven by two cams having different lobes. An ankle slides in holes of the organs which can be aligned. An analysis device verifies that the ankle reaches the coupling position. It receives the signal from a pressure sensor placed in the control pressure line. Arrival in the coupling position is detected by the appearance of a pressure shock, caused by the impact of the ankle against a stop, in the control pressure line. Main application. Internal combustion engines.

Description

Method for monitoring the operation of a coupling device

  The invention relates to a method for monitoring the operation of a coupling device which is associated with an intake or exhaust valve of a

  internal combustion engine, the internal combustion engine

  dull comprising at least two journaling transmission members

  on a common axis and each driven by a trainer

  characterized in one mode of operation a coupling device for coupling the adjacent transmission members in which there is provided, on the transmission members, bores which

  can be put into coincidence and in which is

  an ankle which can be transferred through the

  ducting of a fluid under pressure carried out by means of

  of a control pressure line, in a posi-

  coupling mechanism which couples the transmission

  which is stopped by a stop, and a pressure sensor arranged in the control pressure line, the pressure signal emitted by the pressure sensor being analyzed in a device.

  analysis for monitoring the operation of coupling

  is lying. EP 0 265 281 is known from

  device in which there is provided a device for

  to detect the position of the coupling device For this purpose, a second

  pressure line in which a

  pressure, an opening that connects the second

  pressure line at the piercing of the coupling device

  and recesses carried by the piston of the

  tif coupling; in a disengaged position of the coupling device, the piston allows the pressure fluid to flow from the second pressure line through the recesses and closes the seal opening in the coupling position. position of the coupling device can

  be detected on the basis of the pressure present.

  This device has the disadvantage of requiring a

  second pressure line.

  multi-cylinder internal combustion engine, it is not possible to detect the coupling device on which it

a disturbance occurs.

  Moreover, it is known from document EP

  293 209 F a surveillance device equipped with

  proximity devices but this device is

  very complicated and therefore expensive.

  The object of the invention is therefore to create a method

  of using a device for monitoring a con-

  truction and arranged on a coupling device-

  which can be detected with certainty

  if the ankle has reached the coupling position.

  According to the invention, this problem is solved in that, by comparing the value, or the derivative of the pressure signal with a predetermined threshold value, greater than the pressure of the circuit, for the case of the value, it is verified that 'it appears a pressure shock

  in the control pressure line and that

  the pressure shock, the arrival is detected in posi-

coupling.

  The method according to the invention provides the advantage that it is not necessary to provide additional pressure line or drilling or

  additional recesses on the coupling device

  Compared to coupling devices

  already known, it suffices to provide a pressure sensor

  sion, which can be arranged in a very accessible position

  in the pressure line required for the control of the coupling device, and an analysis device for the analysis of the sensed pressure signal.

  analysis device detects the arrival in position of

  coupling by the appearance of a pressure shock in

  command line, a shock which is caused by the

  riveted ankle abutting against the stop.

  Another simplification is that more

  any coupling devices which can also be arranged in different cylinders of the internal combustion engine can be monitored by a single sensor of

  pressure and by a single analysis device.

  Since the release of the control line and the arrival of the corresponding pin in abutment against the stop are time bound, the fact that the pressure signal is analyzed only for a predetermined period after the release of the control pressure line, reduces the spurious signals that may occur, for example, by reflection of pressure shocks The influence that the temperature or the switching pressure of the hydraulic medium exerts on

  the time the ankle requires to reach the posi-

  coupling can be taken into account by the pre-

  periods T 1 and T 2 which depend on the temperature

  temperature. Other advantages of the invention emerge from

  the description which follows The invention will be described

  Hereinafter with reference to the drawing In this drawing, FIG. 1 shows a valve drive arranged in the cylinder head of an internal combustion engine,

  comprising a coupling device for accom-

  plumb a rocker arm to a coupling lever, in a view from above; Figure 2 shows the valve drive of Figure 1 partly in section;

  FIG. 3 is a schematic diagram of a

  positive analysis for a four-cylinder internal combustion engine; and

  Figure 4 is a flow diagram of the pro-

assigned according to the invention.

  The coupling device 1 shown in the drawing, which is already known, for example, from the unpublished patent application P 42 21 135, will be further briefly described in the following Figures 1 to 3 show

  a cylinder head 2 of an internal combustion engine not shown

  in detail, in which it is provided for each

  lindre two intake valves 3 which are driven

  camshaft 6 by means of transmission members

  4 D respectively To actuate the valves

  3, it is provided for each intake valve

  sion 3 two cams 7 8 mounted on the camshaft 6, one, 7, cams directly driving the valve

  3 by means of a transmission device constituting

  by a rocker arm, while the other cam 8 acts on a transmission member constituted by a lever

  5 The rocker arm 4 and the coupling lever

  5 are rotatably mounted on the same axis 9, the coupling lever 5 being able to be coupled to the rocker arm 4 to

  using the coupling device 1 In this posi-

  coupling, the two levers 4, 5 can not

  more describe than common rotational movements.

  While the diameter of the base circle is as great for each of the two cams 7, 8, the cam 8 associated with the

  coupling lever v presents a different lobe of this-

  it of the cam 7 associated with the rocker arm 4, so that, in the coupling position, the lobe of the cam 7

has no effect.

  The coupling device 1 is composed

  an anchor 10 which is guided in two mobile

  11, 12 extending parallel to the axis 9 the

  11 of the rocker arm being arranged on the rocker arm 4 and the hole 12 of the coupling lever on the coupling lever 5 so that the orifices of the two bores 11, 12 are face to face in alignment when the transmission members 4 , 5 are on

  the base circle of the cam In the drilling it of the cul-

  scorer is housed a spring 13 which is provided on the side directed towards the coupling lever 5, a guiding cup 14 guided movable in longitudinal translation in the bores 11, 12 In the uncoupled state, the spring 13 regrows the pin 10 in the hole 12 of the coupling lever until it abuts against a stop 15 The pin 10 is dimensioned so that the end facing the rocker arm 4 ends in the contact plane when the pin 10 is in support

  against the stop 15, so that in the disengaged state

  plé, nor the guide cup 14 is engaged in the bore 12 of the coupling lever, nor the pin 10

  is engaged in the drilling 11 of the rocker arm.

  To move the coupling device 1 to the coupling position, the side of the pin 10 which is remote from the rocker arm 4 can be loaded by a pressure fluid. For this purpose, it is provided on the front surface of the drilling 12 of the coupling lever

  which is opposite the rocker 4, a chamber of

  16 which is in communication with a source L 9 pressurized oil via a conduit L:

  17 of control pressure and a 3/2 distributor d 8.

  The pressure chamber 16 is formed by the fact that protrusion 20 is provided either on the LJ pin or on the front surface of the lever hole 12

  coupling, to prevent the ankle 10 from becoming

  directly against the front face of the piercing 12 of the coupling lever The sending of the pressure fluid into the pressure chamber 16 can thus push back the

  pin 10 in the hole 11 of the rocker arm, to the

  force of the spring 13, until the

  the guide 14 abuts against a second stop 21 The second stop 21 is arranged in the bore 11 of the rocker arm so that the pin 10 can not

  be fully embedded in the hole 11 of the culbu-

  but remains so that it remains partially, for example half, in the bore 12 of the rocker arm, and thus ensures the coupling of the two elements of

transmission 4, 5.

  In this coupling position, the two

  transmission ganes 4, 5 are integrally connected in rotation to each other, so that, under the effect of the other lobe of the cam 7 associated with the rocker arm 4, the actuation curve of the valve d admission 3 is determined only by the cam 8 associated with the lever

coupling 5.

  To release the coupling, the control pressure line 17 is connected to an oil reservoir 22, by the operation of the distributor 3/2 18, so

  that the oil pressure can be suppressed in the chamber

  16 and that, under this effect, the dowels can be fully pushed out of the piercing

  12 coupling levers in the drilling 11 of the cul-

  scorers by force of springs 13.

  According to the invention as represented on the

  FIG. 3 is an arranged pressure sensor 23.

  in the control pressure line 17, whose

  general d (t) for monitoring the process of

  It is transmitted to an analysis device 24 For the monitoring of the mating process,

  advantage of the fact that, when it reaches the position of

  complete coupling, the pin 10 generates a pressure shock in the pressure fluid circuit abutting against the second stop 21 The evolution in time

  the pressure signal d (t) is monitored in the

  analytical tool 24 and, when a shock of

  pressure, it is concluded that one of the pins 10 has

  dyes the coupling position The detection of a shock

  pressure can be achieved, for example, by comparison

  its continuous signal pressure d (t) or the vara-

  pressure pressure d (t) with thresholds, threshold. In an installation comprising a plurality of coupling devices 1, the analysis device 24 may, in

  presence of a disturbance, find the device for

  1 which is defective by comparing the

  sound with crankshaft angle signal KW, elaborated

  by a position sensor arranged on the crankshaft.

  In an advantageous embodiment, a coupling device 1 can also be connected to a control device 25 connected to the 3/2 distributor 18, which releases

  the control pressure line 17 only

  predetermined periods T 1, so that the ac-

  coupling of transmission components 4, 5 can not be

  only at fully determined times since the expected impact of the pin 10 against the second stop 21 is correlated over time with

  starting the mating process, monitoring

  the evolution of the pressure d (t) in this case has to be carried out only in predetermined periods T 2 after the start of the coupling process If there is a pressure shock in this period T 2, this

  means that the coupling is carried out correctly

  very well, that is to say when no pressure shock is detected, a disturbance of the device is detected

  coupling 1 and appropriate measures are taken.

  The use of the control apparatus 25 is

  especially advantageous in the case of arrangements in the-

  which several coupling devices 1 belonging

  to a cylinder or to different cylinders is or are

  ordered by a control pressure line 17 com-

  mune and monitored by an analysis device 24 com-

  Depending on the succession of cylinders, it may then occur that two successive coupling processes can not be separated exactly in time.

  the choice of the instant, or the angle K W

  when the 3/2-way distributor 18 is open, it is possible to determine which of the coupling devices 1

  which is put in the first place in the position of coupling

  Since the first pressure shock can be detected exactly in each case, it is thus

  possible to carry out a very precise control for this

  Positive coupling 1 The motion detection of

  the control pin of the other coupling devices

  1 depends on the resolution of the pressure signal

  In this way, for processes of access to

  coupling which act on the choice of the setpoint angle of the crankshaft K Wsign, we can

  therefore place one or the other of the coupling devices

  alternatively 1 in the first place in the position

  in this way, to monitor him equally

exactly.

  Since the maneuvering times of the

  coupling device 1 depend on the viscosity of the fluid

  of pressure, it is also possible to calculate the periods T 1 and T 2 as a function of the temperature or

  the pressure of the hydraulic fluid.

  The course of a process according to the invention

  for a multi-cylinder internal combustion engine

  seducing a single analyzer 24 is again

  described in detail below with reference to an organization chart.

  The process is started in block 26, for example, de-

  latched by a command signal from the motor control, to actuate the coupling device 1 of a predetermined cylinder Then, in the block 27, it is checked whether a

  predetermined crank angle K Wsign for the cy-

  corresponding linder is reached as long as the angle of

  pre-determined crankshaft K W is not yet at-

  dyed, we go back to the beginning of block 27 Only when

  that the crankshaft angle K W predetermined setting is reached that, in the block 28, the 3/2 distributor 18 opens and the time measurement is initialized on the value t = O It is therefore possible, by the choice of the angle of

  crankshaft K Wsign, select the device of ac-

  coupling 1 which is placed first in the posi-

  coupling, and which can therefore be

looked after exactly.

  In block 29, it is then checked whether a

  predetermined period T 1 has elapsed since the moment of the opening of the distributor 3/2 18 If it is not the

  case, in block 30, the pressure signal d (t) is

  whether a pressure shock has occurred.

  The occurrence of a pressure shock here means that the pressure d (t) prevailing in the pressure line 17 of

  control briefly exceeds the applied circuit pressure.

  This is detected by comparing the signal of

  pressure d (t) with a threshold value of threshold which is greater than

  A second possibility is to detect, in large slopes of the pressure signal d (t) which occur in the presence of a short pressure peak, by comparison of the derivative d (t) of the signal. time pressure with a predetermined threshold value If no pressure shock is detected, the process is continued in the block 29 If, on the contrary, a pressure shock has been detected in the block 30, it occurs in the block

  31 signaling OK that indicates that the position of

  coupling has been successfully achieved.

  comes at the beginning of block 27, where the process may be

  followed for another coupling device 1.

  If, on the contrary, no pressure shock has

  detected before the end of the predetermined period T 1

  mined, we need to go from block 29 to block 32 where

  distributor 3/2 18 is closed In block 33, we check

  then a predetermined period T 2 has elapsed

  3 As long as this period T 2 has not yet elapsed, we jump to block 32 where we check again if there has been a

  pressure shock in the control pressure line

  If the answer is no, the jump back

  purpose of the block 33 If, on the contrary, a pressure shock is detected in the block 34, it is needle to the block

  31 o, as already described above, it is

  OK Finally, there is the jump back to the beginning of block 27 If, in block 33,

  it is detected that the period T 2 has elapsed, a disturbance

  is detected in block 35 and a signal corresponding to

  is then generated

  jump back to the beginning of block 27.

  The verification of the pressure signal d (t) after the closing of the distributor 3/2 18 in the blocks

  33 and 34 is necessary since, after the arrival in

  In the case of coupling, a certain period of time elapses before the pressure shock reaches the pressure sensor 23. It may therefore occur that the coupling device 1 has reached the coupling position in the course of the first period T 1, but that the pressure shock has reached the pressure sensor 23 after the flow of the first period T 1 The second period T 2 is chosen so that

time delay is compensated.

  Apart from the use indicated in the example

  embodiment, the method according to the invention can

  to be implemented for other purposes

  In this way it is possible to

  put the pressure chamber 16 in the hole 1 L of the rocker arm and the spring 13 in the hole 12 of the lever

  In addition, a coupling device

  1 may also couple more than two

  transmission 4, 5, for example also different

lindres.

Claims (8)

R E V E N D I C A T IO N S   1 Method for monitoring the operation of a coupling device which is associated with a valve   intake or exhaust of an internal combustion engine   dull, the internal combustion engine comprising at least two transmission members journalling   on a common axis and each driven by a trainer   characterized in that a mode of operation, a coupling device for coupling the adjacent transmission members, in which there is provided, on the transmission members, bores which   can be put into coincidence and in which is   an ankle which can be transferred, by introducing   ducting of a fluid under pressure carried out by means of   of a control pressure line, in a posi-   coupling mechanism which couples the transmission   which is stopped by a stop, and a pressure sensor arranged in the control pressure line, the pressure signal emitted by the pressure sensor being analyzed in a device.   analysis for monitoring the operation of coupling characterized in that,   by comparing the amplitude (d (t)) of the pres-   with a predetermined threshold value (threshold) greater than   than the circuit pressure, it is checked whether   there is a pressure shock in the control pressure line (17) and at the onset of the pressure shock,   the arrival is detected in the coupling position.   2 Method for monitoring the operation of a coupling device which is associated with a valve   intake or exhaust of an internal combustion engine   dull, the internal combustion engine comprising at least two transmission members journalling   on a common axis and each driven by a trainer   characterized in that a mode of operation, a coupling device for coupling the adjacent transmission members, in which there is provided, on the transmission members, bores which   can be put into coincidence and in which is   an ankle which can be transferred, by introducing   ducting of a fluid under pressure carried out by means of   of a control pressure line, in a posi-   coupling mechanism which couples the transmission   which is stopped by a stop, and a pressure sensor arranged in the control pressure line, the pressure signal emitted by the pressure sensor being analyzed in a device.   analysis for monitoring the operation of coupling characterized in that,   by comparing the derivative (d (t)) of the pres-   time with a threshold value (threshold), it is checked whether there is a pressure shock in the control pressure line (17) and in that   at the onset of the pressure shock, the in the coupling position.   Method according to Claim 1 or 2, characterized in that a control device (25) arranged in the control pressure line (17) releases the control pressure line (17) only for periods ( Tl) predetermined in that the analyzing device (24) determines whether there is a   pressure shock within the limits of a pre-   completed (T 2) after the release of the control pressure line (17) and that, when there is no pressure shock within the period (T 2), a disturbance is detected of the device coupling (1).   Method according to Claim 1 or 2, characterized in that coupling devices (1)   mounted in different cylinders of a combustion engine   internal multi-cylinder operation are actuated by a   common control pressure drop (17), in that the evolution of the pressure signal (d (t)) over time within the common pressure control line (17) is sensed by a pressure sensor single pressure   (23) and analyzed by the analysis device (24).   Process according to claim 4, characterized   in that the control device (25) does not release the con-   control pressure drop (17) for feeding the dis-   positive coupling (1) following the   only when a predetermined crankshaft angle (K Wsigne) is reached.   Process according to Claim 5, characterized   in that, in the presence of successful mating operations,   the crankshaft angle (K Wsign) is prede-   completed in such a way that different coupling devices   (1) are first placed in the coupling position. Method according to claim 4, characterized   in that the periods (T 1) and / or (T 2) can be modified   depending on the temperature and pressure of the pressure fluid.   Process according to Claim 4, characterized   in that the analyzing device (24) detects the arrangement   coupling device (1) defective in the presence of a de-   storage, by comparison with the signal (KW) of crankshaft.