FR2752441A1 - DEVICE AND PROCEDURE FOR CONTROL OF AN ACTUATOR, ESPECIALLY FOR OPERATING THE VALVES OF AN INTERNAL COMBUSTION ENGINE - Google Patents

Abstract

In a first state, the actuator (35) actuates a first series of transmission devices (9, 11, 21, 23) which are associated with a first group of gas change valves (7a, 7d) of at least two cylinders (1, 2) of an internal combustion engine. In a second state, the actuator deactivates the first series of transmission devices. The controller has means for determining a time interval of a switching window which is associated with one of the transmitting devices. Means are intended to generate a control pulse and the actuator (35), when a control pulse arrives during the time interval of the switching window, deactivates the first set of transmitting devices before the start of the transmission. the travel of the cam acting on the first transmission devices of the first series, or activates this first series of devices.

Description

The present invention relates to a control device and a method

  to control an actuator, which, in a first state, activates a first series of cup push rods which are associated with a first group of gas change valves of at least two cylinders of an internal combustion engine, and which, in a second state, deactivates the first series of

cup push rods.

  In the French patent application filed under No. 97 08798, on July 10, 1997 in the name of the same applicant, an internal combustion engine is proposed comprising at least one camshaft and transmission devices by which the lift stroke cams can be transmitted to gas change valves. The internal combustion engine also has an actuator with which is associated a first series of transmission devices on which it acts so that the first series of transmission devices, in a first state of the actuator, transmits the stroke of lifting of the cams at the gas change valves, and that the first series of transmission devices, in a second state of the actuator, do not transmit the lift stroke to the gas change valve. The internal combustion engine is, moreover, equipped with a control device which controls the actuator in the first or second state. An embodiment of the control device, or a method of controlling the actuator, does not

  are not described in the patent application cited above.

  The object of the invention is to create a control device, which is reliable, for controlling an actuator and

  to propose a method for controlling the actuator.

  This problem is solved according to the invention by a control device of the type indicated above, which - comprises means intended to determine a first reference instant, which is predefined by the start of the lift stroke of an acting cam on a first transmission device of the first series, and intended to determine a second reference instant, which is predefined by the start of the lift stroke of a cam acting on a second transmission device of the first series, the first instant of reference directly following the second reference instant and this in the order of succession of all the starts of lifting of the cams which act on the transmission devices of the first series, - includes means for determining a time interval (TsF ), of a switching window, interval which is obtained from the formula TSF = TE + TMIN - TmAx, TE being the difference in time between the first er reference time t, 1 and the second reference time tB2, TMIN being a predefined minimum switching time and Tx

  a predefined maximum switching time.

  - comprises means for determining an end of the switching window, end which is in front of the first reference instant t.1, offset by the maximum switching time Tmx, - comprises means for producing an ISTI command pulse l actuator deactivating the first series of transmission devices from before the first reference instant t.1, during a transition from the first state to the second state, or activating it, during a transition from the second state to the first state, and this, when the IST command pulse intervenes during the interval

  TSF time window of the switching window.

  The problem mentioned above can also be solved according to the invention, by a device which - comprises means for determining a first reference angle, which is predefined by the start of the lift stroke of a cam acting on a first device transmission of the first series, and to determine a second reference angle, which is predefined by the start of the lift stroke of a cam acting on a second transmission device of the first series, the first reference angle directly following at the second reference angle and this in the order of succession of all the starts of lifting of the cams which act on the transmission devices of the first series, comprises means for determining an angular deviation of the crankshaft corresponding to a switching window, angular deviation which is obtained from the formula WSF = WHH + (TMIN - Tmx) * N * C, W. being the angular deviation of the crankshaft between the first reference angle and the second reference angle, TMIN being a predefined minimum switching time, TM <a predefined maximum switching time, N the crankshaft rotation speed and C a proportionality constant, includes means for determining an end of the switching window, end which is in front of the first angle. reference, offset by the crankshaft angle corresponding to the maximum switching time Tm, and - includes means for producing a control pulse IST 'the actuator deactivating the first series of transmission devices from before the first reference angle , during a transition from the first state to the second state, or activating it, during a transition from the second state to the first state, when the control pulse occurs during the angular interval of

  switch window crankshaft.

  A subject of the invention is also a method, of the type enabling an actuator to be controlled, which, in a first state, actuates a first series of transmission devices which are associated with a first group of gas change valves at minus two cylinders of an internal combustion engine, and which, in a second state, deactivates the first series of transmission devices, - by determining a first reference instant, which is predefined by the start of the stroke of an acting cam on a first transmission device of the first series, and a second reference instant, which is predefined by the start of the lift stroke of a cam acting on a second transmission device of the first series, the first reference instant making directly following the second reference instant and this in the order of succession of all the starts to lift the cams which act on the transmission devices ion of the first series, - by determining a TSF time interval of a switching window, which is obtained from the formula

TSF = T} + TMIN - TMAX

  TE being the time difference between the first reference time and the second reference time, TMIN being a predefined minimum switching time and Tmx a

  predefined maximum switching time.

  - by determining an end of the switching window, end which is before the first reference instant, offset by the maximum switching time TMx, - by being able to produce a control pulse, so that upon arrival of the control pulse during the time interval of the switching window, the first series of transmission devices is deactivated before the first reference instant, during a transition from the first state to the second state, or is activated during a transition from the second state to

first state.

  The solution according to the invention has the advantage that one can, in a simple manner, activate and deactivate a first series of transmission devices. It also allows advantageously that a predetermined gas change valve, if the transmission devices are deactivated, no longer performs any lift first and that, if the transmission devices are activated, a change valve of predetermined gas performs

  precisely, again, first, the lifting.

  In advantageous embodiments of the control device, the invention provides - that the minimum switching time and / or the maximum switching time be corrected as a function of the temperature of the hydraulic fluid of the internal combustion engine, - that the duration minimum switching time and / or maximum switching time are corrected according to the viscosity of the hydraulic fluid of the internal combustion engine, and the minimum switching time and / or maximum switching time are corrected according to the pressure of the hydraulic fluid of the internal combustion engine, - that the minimum switching time and / or the maximum switching time depend on whether deactivation occurs, or whether activation of

  transmission devices of the first series.

  In another advantageous embodiment of the invention, a first actuator is associated with the first series of devices for transmitting a first group of cylinders. A second actuator is associated with a second series of devices for transmitting a second group of cylinders. The cylinders of the internal combustion engine are associated either with the first group of cylinders, or with the second group of cylinders, in such a way that in operation with ignition of all the cylinders, the ignition takes place alternately on one of the

  cylinders of the first and second group of cylinders.

  This advantageous embodiment of the invention is distinguished by the fact that a deceleration operation at high speed of the internal combustion engine is still ensured if the first series of transmission devices, or the second series of transmission devices.

transmission, are disabled.

  Advantageously, the minimum switching time and / or the maximum switching time depend on the actuator to which either the first or the

  the second bowl push rod.

  An exemplary embodiment of the invention will be described below in more detail, with reference to the schematic drawing, in which: FIG. 1 is a block diagram of an internal combustion engine comprising the control device according to the invention ; Figure 2 is a view of a gas change valve according to Figure 1; Figures 3a, 3b, 3c show the course over time of a switching phase; Figure 4 is a flowchart showing the determination of a switching window; FIG. 5 is a block diagram of a preferred embodiment of the internal combustion engine comprising the control device according to the invention; FIG. 6 is a diagram of the succession of ignitions, related to time t; Figure 7 is another diagram of the succession

  of ignitions related to the angle KW of the crankshaft.

  The elements having the same construction and the same function are indicated in the figures with the same references. An internal combustion engine (FIG. 1) has cylinders 1, 2 and transmission devices, produced in the form of cup push rods 9, 11, 21, 23, which are each associated with a gas change valve. . Thus, the bowl push rods 9 and 21 are associated with the intake valves 7a, 7c and the bowl push rods 11 and 23 are associated with the exhaust valves 7b, 7d. The cup push rods 9, 11, 21, 23 are each arranged in a valve mechanism 8a, 8b, 8c, 8d. The valve mechanism 8a to 8d and the cup push rods 9, 11, 21, 23 are shown in more detail using FIG. 2. The internal combustion engine is also equipped with a power supply hydraulic 33, made, for example, in the form of an oil pump. The hydraulic supply 33 is connected, via a supply line 34, to a first actuator 35, produced in the form of a switching valve. The first actuator 35 is connected via a first hydraulic line 36, to the cup push rods 9, 11, 21, 23, which form a first series. The first actuator 35 is, moreover, connected to the hydraulic supply via a first return 37a. In a first state Z1, the hydraulic line 36 is connected to the first return 37a. Then, in the first state Zi, the hydraulic fluid returns, flowing from the first hydraulic line 36 into the hydraulic supply 33 passing through the first return 37a. In a second state Z2 of the switching valve, the first hydraulic line 36 is connected to the supply line 34. Then, in the first hydraulic line 36, the pressure is established which is

  determined by hydraulic supply 33.

  The internal combustion engine also comprises a control device 40 according to the invention, which detects different measurement quantities by means of sensors, such as, for example, a crankshaft angle indicator 41, a pressure detector at the tube intake, or a mass air flow meter 42 and an indicator of the position of the accelerator 43. Depending on one or more of these quantities, the control device puts the first actuator 35 in the first state Z1 or in the second state Z2. FIG. 1 shows two cylinders 1, 2. However, it is obvious to a person skilled in the art that the internal combustion engine can also have a

greater number of cylinders.

  The valve mechanism 8a is described below with the aid of FIG. 2. The mounting of the valve mechanisms 8b, 8c, 8d is identical to the valve mechanism 8a shown in FIG. 2. The valve mechanism 8a for the inlet valve 7a consists of a camshaft 44, comprising a cam 45, which transmits the lift stroke to a cup push rod 9. The cup push rod 9 comprises a first body 9a and a second body 9b. A guide body 46 receives the cup push rod 9 and a first and a second spring 48, 49, which urge the cup push rod 9, so that the second body 9b comes into contact with the shaft to cams 44 or cam 45 and the first body comes into contact

of the inlet valve 7a.

  The first body 9a has a first bore 50, which coincides with a second bore 51 in the second body 9b, when the second body 9b comes into contact with the camshaft 44. The second bore receives a stud 52 and a spring stud 53. The stud spring 53 biases the stud 52 in the direction of the first bore 50. The first bore 50 is connected to the first hydraulic line 36. In the first state Zl of the actuator 35, the stationary pressure P of the fluid hydraulic in the first bore 50 is so weak that the stud 52 is located, in part, in the first bore and, in part, in the second bore. As a result, the first body 9a and the second body 9b are connected by

conjugation of forms.

  In the second state Z2 of the first actuator 35, the stationary pressure P of the hydraulic fluid in the first bore 50 is high enough for the stud 52 to be pushed back into the second bore 51, opposing the force of the spring of stud 53. Therefore, in the second state Z2 of the first actuator 35, the first body 9a and the second body 9b are not connected by conjugation of shapes. Thus, in the second state Z2 of the first actuator 35, the lift stroke of the cam 45 is not transmitted to the intake valve 7a. The change of state from a cup push rod 9 activated to a cup push rod 9 deactivated, and vice versa, can only be done if the second body 9b is directly in contact with the camshaft. In the first state Z1 of the first actuator 35, the stud 52 is wedged between the first and the second body 9a, 9b, or the first bore 50 and the second bore 51 do not come into coincidence, so that the stud cannot to be moved. In FIG. 3, the sequence over time of a switching phase is shown. In FIG. 3a, the plot of the voltage applied to the actuator is reported for the time t. In FIG. 3b, the state ST of the first actuator 35 is reported for the time t. In FIG. 3c, the pressure P of the hydraulic fluid is reported in the first bore 50 precisely of a cup push rod 9 to 32 (see FIG. 5) during the time t. At time tsT, a control pulse IST is produced by the control device 40. As a result, the voltage, produced by the control device 40 to control the first actuator 35, jumps, at time tST? from a U1 value to a U2 value. This voltage jump produces a change in position of a switching valve of the first actuator 35. The switching valve changes its position from state Z1 to state Z2, with a certain delay. In state Z2, the supply line 34 is connected to the first hydraulic line 36. However, the pressure POIL of the hydraulic fluid prevailing in the supply line 34 is established in the first bore, after switching of the actuator 35 from state Z1 to state Z2, only with a time delay, since the switching of the first actuator 35 from the first state Zi to the second state Z2 creates a pressure wave which develops with a finite speed, and in the case of which appear pressure losses which are determined by the geometry

  of the first hydraulic line 36.

  At the instant tsH, the pressure P of the hydraulic fluid in the first bore 50 reaches a threshold value Psi, which, the second body 9b being in contact with the camshaft 44, is sufficient to push, by opposing the force of the stud spring 53, the stud 52 in the second bore 51. The switching time for one of the cup tappets 9 to 32 is thus predefined by the time difference between the instant tsH and the instant tST. After the appearance of an ISTI command pulse, activation or deactivation of the cup push rod 9 to 32 is then possible, at the earliest after the switching time. The switching phase during a change of state of the first actuator 35, causing the passage of the second state in

  the first state is carried out in a similar manner.

  Due to the different arrangement of the cup push rods compared to the first actuator, communication times are obtained

  different for different cup push rods.

  A minimum switching time TMIN and a maximum switching time Tx are determined empirically under standard conditions (for example, outside temperature 20 C and hydraulic fluid pressure 2 bar), and are stored in a memory, not shown, of the order 40, where available

  during operation of the internal combustion engine.

  Thus, it is determined, for example, for each cup push rod 9, 11, 21, 23, the switching time. The highest value in absolute value of the measured switching times is assigned to the maximum switching time Tx and the smallest value in absolute value is

  assigned to the minimum switching time TMIN.

  A method for determining the switching window will be explained below, using a flow diagram (FIG. 4). This process is preferably carried out in the form of a program which is permanently stored in the control device 40 and which is called

  for the operation of the internal combustion engine.

  At a step S1, the process is launched and, if necessary

  if necessary, initializations are carried out.

  In a step S2, the minimum switching time TMIN and the maximum switching time Tmx are taken from the

  memory and stored in the controller 40.

  In step S3, a first reference instant tB1 and a second reference instant tB2 are determined. The first reference instant tB1 is defined by the start of the lift stroke of a first cup push rod 9, 11, 21, 23 of the first series of acting cams. The first cup push rod 9, 11, 21, 23 is each time the cup push rod 9, 11, 21, 23 which, when switching cup push rods 9, 11, 21, 23 deactivated with cup push rods 9, 11, 21, 23 activated from the first series, transmits, in turn, first the lift stroke to the gas change valve associated with it, or else in the in the case of a switch from cup push rods 9, 11, 21, 23 activated to cup push rods 9, 11, 21, 23 deactivated from the first series, the first cup push rod 9, 11, 21, 23 is, in time, that which does not transmit the lift stroke to the gas change valve associated with it. The second reference instant tB2 is predefined by the start of lifting of a cam acting on a second cup push rod 9, 11, 21, 23 of the first group. The first reference instant tR, directly follows the second reference instant tB2, and this in the order of succession of all the starts of lifting of the cams which act on the

  cup push rods from the first series.

  In step S4, the difference in time T is then determined, from the difference between the first reference instant tB1 and the second instant of

reference tB2.

  In step S5, a minimum corrected switching time TMINc is determined. The corrected minimum switching time TMINc is allocated by means of a characteristic field depending on the minimum switching time TMIN and / or a TOIL temperature of the hydraulic fluid and / or a POIL pressure of the hydraulic fluid and / or of the state ST of the first actuator 35. By the correction depending on the temperature TOIL of the hydraulic fluid, the differences in viscosity of the hydraulic fluid due to different temperatures are advantageously taken into account. The viscosity of the hydraulic fluid has a decisive influence on the switching time. Direct entry of the viscosity of the hydraulic fluid is particularly advantageous, since it is then possible to carry out a precise correction of the minimum switching time TMIN independently of the type of hydraulic fluid used. A correction of the minimum switching time TMIN and / or the maximum switching time TMx as a function of the POIL pressure of the hydraulic fluid is very advantageous, since the minimum and / or maximum switching time TMIN, Tx is

  strongly influenced by this size.

  In step S6, a maximum corrected switching time Tmxc is determined, from a field of characteristics depending on the maximum switching time Tmx, the temperature TOIL of the hydraulic fluid, the pressure POIL of the hydraulic fluid and ST state of the actuator. The corrections made in steps S5 and S6 represent, of course, a set

  exhaustive of possible corrections.

  In a step S7, a switching time TSF of a switching window SF is determined. The switching time is obtained from the formula TSF = TE + TMINC - TmAxc The TSF time interval and the maximum corrected switching time Tmxc are associated with each of the cup push rods concerned and are available

  during operation of the internal combustion engine.

  In a step S8, the process is terminated. The method of Figure 4 is studied for any first cup push rod. Advantageously, according to a predefined time diagram, the values of the corrected minimum duration of switching TMINC, of the corrected maximum duration of switching TACx and of the switching duration TSF of the

  SF switching window are updated.

  In Figure 5, there is shown a block diagram of a preferred embodiment of the internal combustion engine. The internal combustion engine of Figure 5, unlike the internal combustion engine shown in Figure 1, is equipped with six cylinders 1 to 6. It also has, next to the first actuator, a second identical actuator 38 , which is associated with a second series of cup push rods 15 to 20, 27 to 32 of a second group of cylinders. In this exemplary embodiment, the first actuator is associated with the first series of cup push rods 9 to 14, 21 to 26. The cylinders 1 to 6 of the internal combustion engine are therefore associated either with the first group of cylinders, either in the second group of cylinders, so that when one of the cylinders 1 to 6 is ignited, one of the cylinders in the first is alternately ignited

  and one of the cylinders of the second group of cylinders.

  The hydraulic supply 33 is connected, via the supply line 34, to the second actuator 38. The second actuator 38 is connected, via a second hydraulic line 39, to the second series of rods -cuvet plungers 15 to 20, 27 to 32. The second actuator 38 is connected, via a second return 37b, to the hydraulic supply 33. The operating mode of the second actuator 38 is identical to that of the first actuator 35. The advantage of this arrangement is that, as a function of IST control pulses, the first series of cup push rods 9 to 14, 21 to 26 and the second series of cup push rods 15 to 20, 27 to 32 can be deactivated and activated alternately, independently of one another. Thus, for example, in operation under reduced load of the internal combustion engine, the first series of cup push rods 9 to 14, 21 to 26 and the second series of cup push rods 15 to 20, 27 to 32 are alternately activated and deactivated for a given number of ignition successions. Thus, the cylinders of the activated cup push rods are each implemented with an increased filling rate, which provides a reduction in the

  fuel consumption and reduced emissions.

  In FIG. 6, a diagram has been plotted, as a function of time, of the succession of ignitions of cylinders 1, 2, 3 of the first group of cylinders of the internal combustion engine represented in FIG. 5. An arrow indicates each time the instant of an ignition pulse, and a rectangle indicates, in the longitudinal direction, the switching window SF. AO has designated open exhaust valves of each cylinder concerned, and EO has opened intake valves of each cylinder concerned. The curves above each time represent the lift stroke of the intake and exhaust valves of each of the affected cylinders. AG indicates the exhaust valve closed, EG the valve

admission closed.

  We will describe, by way of example, an operation of switching from cup pushers, activated, 9 to 14, 21 to 26 of the first series into push rods with

  bowl disabled 9 to 14, 27 to 32 of the first series.

  As a function, for example, of the rotational speed N of the crankshaft of the internal combustion engine and of a positioning value of the accelerator pedal, noted by the accelerator position indicator 43, the control device 40 determines whether the first series of cup push rods 9 to 14, 21 to 26 should be disabled. If the first series of cup push rods 9 to 14, 21 to 26 is to be disabled, it is determined which of the first gas change valves should no longer be lifted. If, for example, it is the intake valve 7c of the cylinder 2 which is no longer to be lifted, then the switching window SF is determined for the cup push rod 11 associated with the intake valve 7c . The cup push rod 11 is then, in this case, the first cup push rod. The second cup push rod is the cup push rod 23, which is associated with the exhaust valve 7d of the second cylinder 2. The first reference instant tBl is then the start of lifting of the cam 45 associated with the first bowl push rod. The second reference instant tB2 is the start of lifting of the cam acting on the second cup push rod. The end of the switching window is determined by the first reference instant tB1 as a function of the corrected maximum switching time TAcs. The TSF duration of the switching window

  SF is determined according to figure 4.

  The control unit 40 produces the control pulse IST during the time interval TSF of the switching window SF. It is thus guaranteed that the exhaust valve 7d of cylinder 2 is still subject, after the IST control pulse to a lift, and that, on the other hand, the intake valve 7c of cylinder 2 is no longer subjected to a lift . As the duration TSF of the switching window strongly depends on the rotation speed N of the motor, the duration TSF is advantageously calculated from

  again at predetermined time intervals.

  In FIG. 7, another diagram of the succession of ignitions is reported as a function of the angle of the crankshaft. Unlike FIG. 6, the time values are represented by corresponding values of the angle of the crankshaft. The crankshaft angle values are obtained by a corresponding multiplication of the associated time values, by the rotational speed N of the crankshaft and by a proportionality constant C, which has, for example, a value of 6. A first reference angle WB1 is predefined by the start of lifting of a cam acting on the first cup push rod of the first series. A second reference angle W.2 is predefined by the start of lifting of a cam acting on

  the second cup push rod of the first series.

  An angular deviation WSF of the switching window SF is given by the relation

WSF = WH + (TMIN - Tmx) * N * C.

  W. here denotes the angular difference of the crankshaft

  between the first and second reference angles WB1, W2.

  Another improvement in precision of the minimum and maximum switching times TMIN, Tm in the case of an embodiment of the invention according to FIG. 5 is obtained if the minimum and maximum switching times TMIN, TM for the first series cup push rods are corrected by a first correction factor and if the minimum and maximum switching times TMIN, Tmx for the second series of cup push rods

  are corrected by a second correction factor.

  The transmission devices can also be produced otherwise, for example, in the form of drive levers or pivoting levers. As an alternative to the hydraulic control for activating and deactivating the cup push rods, there can also be provided a

electromagnetic control.

Claims (9)

  1. Control device, intended to control an actuator (35), which, in a first state (Zl), activates a first series of transmission devices which are associated with a first group of gas change valves of at least two cylinders (1 - 6) of an internal combustion engine, and which, in a second state (Z2), deactivates the first series of transmission devices, this device - comprising means intended to determine a first reference instant ( tBl), which is predefined by the start of the lift stroke of a cam acting on a first transmission device of the first series, and intended to determine a second reference instant (tB2), which is predefined by the start of the race lifting of a cam acting on a second transmission device of the first series, the first reference instant (tB3) directly following the second reference instant (tB2) and this in order of success ssion of all the beginnings of lifting of the cams which act on the transmission devices (9 to 32) of the first series, - comprising means for determining a time interval (TSF) of a switching window, interval which   is obtained from the formula -   TSF = T} + TMIN - TmAx, TE being the time difference between the first reference instant (tB1) and the second reference instant (tB2), TMIN being a predefined minimum switching time and   T. a predefined maximum switching time.   - comprising means for determining an end of the switching window (SF), end which is in front of the first reference instant (tBî), offset by the maximum switching time Tmm, comprising means for producing a control pulse (IST), the actuator (35) deactivating the first series of transmission devices before the first reference instant (tBl), during a transition from the first state (Zl) to the second state (Z2), or l activating, during a transition from the second state (Z2) to the first state (Zl), and this when the control pulse (IsT) intervenes during the time interval (TSF) of the switching window (SF).   2. Control device, intended to control an actuator (35), which, in a first state (Z1), activates a first series of transmission devices which are associated with a first group of gas change valves of at least two cylinders (1 - 6) of an internal combustion engine, and which, in a second state (Z2), deactivates the first series of transmission devices, - comprising means for determining a first reference angle (WB.) , which is predefined by the start of the lift stroke of a cam acting on a first transmission device of the first series, and to determine a second reference angle (WB2), which is predefined by the start of the lift stroke d '' a cam acting on a second transmission device of the first series, the first reference angle (WB1) directly following the second reference angle (WB2) and this in the order of succession of all the beginnings of lifting s cams which act on the transmission devices of the first series, - comprising means for determining an angular deviation of the crankshaft (WSF) corresponding to a switching window (SF), angular deviation which is obtained from the formula WSF = WHH + (TMIN - TmAx) * N * C W. being the angular deviation of the crankshaft between the first reference angle (W51) and the second reference angle (WI2), TMIN being a predefined minimum switching time, Tmx a predefined maximum switching time, N the speed of rotation of the crankshaft and C a proportionality constant, comprising means for determining an end of the switching window (SF), end which is in front of the first reference angle (WB. ), offset by the crankshaft angle corresponding to the maximum switching time TMx, and - comprising means for producing a control pulse (IsT), the actuator deactivating the first series of devices transmission factors from before the first reference angle (WBl), during a transition from the first state (Z1) to the second state (Z2), or activating it, during a transition from the second state (Z2) in the first state (Zl), when the control pulse (IST) occurs during the angular interval (WSF) of the switching window (SF).   3. Control device according to claim 1 or claim 2, in which the minimum switching time (TMIN) and / or the maximum switching time (Tx) are corrected as a function of the temperature (TOIL) of the   hydraulic fluid of the internal combustion engine.   4. Control device according to claim 1 or claim 2, wherein the minimum switching time (TMIN) and / or the maximum switching time (TMx) are corrected as a function of the viscosity of the fluid.   internal combustion engine hydraulics.   5. Control device according to claim 1 or claim 2, wherein the minimum switching time (TMIN) and / or the maximum switching time (Tx) are corrected as a function of the pressure (POIL) of the   hydraulic fluid of the internal combustion engine.   6. Control device according to claim 1 or claim 2, in which the minimum switching time (TMIN) and / or the maximum switching time (TMx) depend on whether deactivation occurs, or that there is an activation of the   transmission of the first series.   7. Control device according to claim 1 or claim 2, wherein a first actuator (35) of a first series of transmission devices is associated with a first group of cylinders, and a second actuator (38) of a second series of transmission devices is associated with a second group of cylinders, and the cylinders (1 to 6) of the internal combustion engine are associated either with the first group of cylinders or with the second group of cylinders so that in operation with ignition of all the cylinders (1-6), the ignition is done alternately on one of the cylinders (1 to 6) of the first group, then on one cylinders of the second group.   8. Control device according to claim 7, in which the minimum switching time (TMIN) and / or the maximum switching time (Tx) depend on the actuator (35, 38), to which is connected either the first or the second cup push rod (9 to 32). 9. Method for controlling an actuator (35), which, in a first state (Zl), actuates a first series of transmission devices which are associated with a first group of gas change valves of at least two cylinders (1 - 6) of an internal combustion engine, and which, in a second state (Z2), deactivates the first series of transmission devices, in which - a first reference instant (tBl) is determined, which is predefined by the start of travel of a cam acting on a first transmission device of the first series, and a second reference instant (tB2), which is predefined by the start of lift stroke of a cam acting on a second transmission device of the first series, the first reference instant (tB1) directly following the second reference instant (t, 2) and this in the order of succession of all the beginnings of lifting of the cams which act on the transmission devices ssion of the first series, - a time interval (TSF) of a switching window (SF) is determined which is obtained from the formula TSF = TH + TMIN - TmAx, TE being the difference in time between the first reference instant (tB1) and the second reference instant (tB2) TMIN being a predefined minimum switching time and   TMM a predefined maximum switching time.   - an end of the switching window (SF) is determined, end which is before the first reference instant (tBl), offset by the maximum switching time (Tmx), and - a control pulse (IST) is produced in such a way that on arrival of the control pulse (IST) during the time interval (TSF) of the switching window (SF), the first series of transmission devices is deactivated before the first instant (tBl), during a transition from the first state (Zl) to the second state (Z2), or is activated during a   passage from the second state (Zi) to the first state (Z2).