EP1756405A1 - Device for varying a compression ratio of an internal combustion engine and method for using said device - Google Patents

Device for varying a compression ratio of an internal combustion engine and method for using said device

Info

Publication number
EP1756405A1
EP1756405A1 EP04816459A EP04816459A EP1756405A1 EP 1756405 A1 EP1756405 A1 EP 1756405A1 EP 04816459 A EP04816459 A EP 04816459A EP 04816459 A EP04816459 A EP 04816459A EP 1756405 A1 EP1756405 A1 EP 1756405A1
Authority
EP
European Patent Office
Prior art keywords
compression ratio
varying
eccentric
piston
ratio according
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
EP04816459A
Other languages
German (de)
French (fr)
Other versions
EP1756405B1 (en
Inventor
Michel Marchisseau
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
IFP Energies Nouvelles IFPEN
Original Assignee
IFP Energies Nouvelles IFPEN
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by IFP Energies Nouvelles IFPEN filed Critical IFP Energies Nouvelles IFPEN
Publication of EP1756405A1 publication Critical patent/EP1756405A1/en
Application granted granted Critical
Publication of EP1756405B1 publication Critical patent/EP1756405B1/en
Not-in-force legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02D—CONTROLLING COMBUSTION ENGINES
    • F02D15/00—Varying compression ratio
    • F02D15/02—Varying compression ratio by alteration or displacement of piston stroke
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02B—INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL
    • F02B75/00—Other engines
    • F02B75/04—Engines with variable distances between pistons at top dead-centre positions and cylinder heads
    • F02B75/045—Engines with variable distances between pistons at top dead-centre positions and cylinder heads by means of a variable connecting rod length
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02B—INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL
    • F02B75/00—Other engines
    • F02B75/04—Engines with variable distances between pistons at top dead-centre positions and cylinder heads
    • F02B75/047—Engines with variable distances between pistons at top dead-centre positions and cylinder heads by means of variable crankshaft position

Definitions

  • the present invention relates to a device for varying the compression ratio of an internal combustion engine and a method allowing the use of such a device. It relates more particularly to a device which can change the compression ratio of this engine by modifying the dead volume of the combustion chamber at the top dead center of the piston.
  • the eccentric is not an eccentric of the towed type but a motorized eccentric thanks to the cooperation of 'a toothed sector of this eccentric with a worm.
  • This device has a major drawback in the sense that the worm must be motorized to control the rotation of this eccentric.
  • This motorization is bulky and requires high powers to overcome the inertia of the moving part and the various frictions.
  • the present invention proposes to overcome the above-mentioned drawbacks by means of a device for varying the compression ratio of simple and space-saving design which makes it possible to increase the possibilities of variation of the compression ratio.
  • the present invention relates to a device for varying the compression ratio of an internal combustion engine comprising at least one cylinder with a combustion chamber, a movable assembly comprising a piston displaceable in translation under the action of a connecting rod connected by an axis to said piston and connected to a crankpin of a crankshaft, said piston making a stroke between a top dead center and a bottom dead center while leaving a dead volume at the top dead center of said piston, the device comprising an eccentric rotary tractor for varying the compression ratio and means for controlling the movement of the eccentric, characterized in that the control means comprise a fluid cylinder comprising a slide placed in a housing formed in a support and delimiting two fluid chambers in communication with at least one closed circuit. The fluid chambers can be in communication with each other by at least one closed circuit. .
  • the closed circuit may include at least one valve means making it possible to. control the flow of fluid from one chamber to the other.
  • valve control means can be a valve with at least two channels.
  • valve means can be a piezoelectric device.
  • the piezoelectric device may include a needle and a piezoelectric actuator.
  • the piezoelectric device can be controlled by cooperation of pads and electrical tracks.
  • the circuit may include at least one metering device located downstream of the valve means.
  • the metering device may include a piston-cylinder assembly with a calibration spring.
  • the elements of the closed circuit can be at least partially housed in the jack.
  • the variation device may include means for locating the position of the eccentric.
  • the location means may include a transmitter-receiver assembly of signals.
  • the eccentric may include the transmitter and the receiver may be housed on a fixed part of the motor.
  • the eccentric may include means for form cooperation with the slide.
  • the cooperation means may include a toothed sector carried by the eccentric and a toothed bearing carried by the slide.
  • the invention also relates to a method of varying the compression ratio of an internal combustion engine, said engine comprising at least one cylinder with a combustion chamber, a movable assembly comprising a piston movable in translation under the action of a connecting rod connected by an axis to said piston and connected to a crankpin of a crankshaft, said piston making a stroke between a top dead center and a bottom dead center while leaving a dead volume at the top dead center of said piston, characterized in that the method consists in: - determining the desired compression ratio of the motor, - determining the extent of displacement of a rotary towed eccentric to obtain the desired compression ratio, - controlling the rotation of the eccentric to obtain the determined displacement.
  • An advantage of the present invention over the devices of the prior art lies in the fact that the energy loss of the bearing function between the connecting rod and the crankpin of the crankshaft is less.
  • the compression ratio does not vary, the position of the eccentric relative to the connecting rod is fixed and the bearing function between the connecting rod and the crankpin is achieved by the relative displacement between the eccentric and the crankpin of the crankshaft . Therefore, the bearing function between the connecting rod and the crankshaft is achieved with a smaller bearing diameter, which is a significant advantage because as it is known the energy loss of a bearing, for a given load under normal operating conditions, is an increasing function of its diameter.
  • Another advantage of the present invention is easier control of the adjustment of the compression ratio.
  • the present invention uses a reversible kinematic link which continuously links the angular movement of the eccentric to the translation of the slide. Therefore, the angular setting of the eccentric and consequently the adjustment of the compression ratio, is a continuous function of the position in translation of the slide defined by the mechanical construction of the device according to the invention. Therefore, at no time can the compression ratio vary without the translational position of the slider being modified and, thanks to the hydraulic device of the present invention, control of the position of the slider is easily obtained.
  • Other additional advantages of the present invention are lower energy loss, greater precision and longer service life.
  • the present invention uses a reversible kinematic connection to continuously link the angular movement of the eccentric to the translation of the slide.
  • the friction in this connection can be minimized by construction. Thanks to this, the energy loss by friction of this connection, the wear of this connection and the amplitude of the hysteresis phenomena can be all three less. In addition, the lowering of the amplitude of the hysteresis phenomenon leads to a better precision of the adjustment of the compression ratio. In addition, due to its reversibility, the kinematic connection of the present invention does not present a risk of jamming.
  • the device of the present invention makes it possible to have a reduced weight and bulk as well as greater responsiveness in adjusting the compression ratio. In fact, because the eccentric is towed, the adjustment of the compression ratio does not require a motor for driving the eccentric and the device is therefore not penalized by the weight, by the size and by the response times of a specific engine and its kinematic connections to drive the eccentric in rotation in order to adjust the compression ratio.
  • this device has other advantages such as compatibility with a shorter distance between the axis of the crankshaft and the cylinder head of the engine, less vibration and a lower production cost.
  • the jack whose function is to control the position of the eccentric placed between the connecting rod head and the crankshaft crankpin is distinct from said eccentric, in particular its slide is distinct from all the other parts and is movable relative to all these other pieces. Thanks to this, a wide choice of orientation of said jack with respect to the connecting rod is allowed, which simultaneously optimizes the distance between the axis of the crankshaft and the cylinder head as well as the vibrations induced by the movable assembly and also the shapes for reducing manufacturing costs.
  • FIGS. 1 which shows, in axial section, a motor with internal combustion with the device for varying the compression ratio according to the invention in a first position
  • - Figure 2 is another view, in axial section, showing the internal combustion engine with the device of Figure 1 in another position and in another configuration
  • - Figure 3 is a detail view in an extreme position of the device of the invention of Figure 1
  • - Figure 4 is a diagram showing the control circuit used for the device according to the invention
  • - Figure 5 is another detail view of the device showing the various elements of the control circuit carried by the device according to the invention
  • - Figure 6a is another detail view of the available sitive showing a variant of one of the elements of the control circuit of the device according to the invention while FIGS.
  • FIGS. 7a to 7d are another illustration of a device for locating the angular position of one of the elements of the device for varying the compression ratio according to the invention.
  • Figures 1 to 3 which show an internal combustion engine with at least one cylinder 10 which comprises a bore 12 inside which slides a hollow piston 14 in an alternating translational movement under the impulse of a connecting rod 16
  • This piston defines with its upper part, the side wall of the bore 12 and the upper part of this bore, generally formed by a part of the cylinder head 18, a combustion chamber 20 in which the combustion cycle takes place.
  • the piston carries two diametrically opposite radial bores 22 through which is housed a cylindrical axis 24 which connects one end 26 of the connecting rod, known as the connecting rod foot, to said piston by passing, by sliding, a bore 28 provided in the connecting rod foot.
  • the other end 30 of the connecting rod, called the connecting rod head, is connected by a device for varying the compression ratio 32 to a crankpin 34 of a crankshaft 36.
  • This crankshaft is subjected to a rotational movement about an axis XX so that the crankpin 34 follows a circular path 38 around the axis XX.
  • the piston 14, the connecting pin 24, the connecting rod 16, the crankshaft 36 with its crankpin 34 form the movable assembly of the engine.
  • the crankpin 34 passes successively from a high position, indicated 0 ° in FIG. 1, to a low position, indicated 180 ° .
  • the piston 14, which is connected to the crankpin 34 by the connecting rod 16 undergoes a reciprocating translational movement between an initial top dead center (referenced P Hi in FIG. 1) which corresponds to the top position of the crankpin and a point initial low dead (referenced PMBi in Figure 2) corresponding to the low position of the crankpin.
  • P Hi initial top dead center
  • PMBi point initial low dead
  • the compression ratio of an engine is a function not only of the extent of the volume of the cylinder delimited by the stroke of the piston but also of the extent of the dead volume. To modify the compression ratio, it suffices to modify one of these volumes and more particularly the magnitude of the dead volume. To do this, the compression ratio variation device 32 comprises an eccentric 42 housed between the crank pin 34 and a bore 44 provided in the connecting rod head 30.
  • This eccentric has a generally circular shape with a geometric axis X1X1 which corresponds to its middle axis and comprises a bore 46 of axis X2X2 not coaxial with the axis X1X1 but coincident with the axis of the crank pin 34.
  • This eccentric is housed in sliding in the receiving bore 44 produced in the big end and on the peripheral wall of the crankpin 34.
  • This eccentric is said to be towed because, during the operation of the engine, it is likely to be driven in rotation around the axis X2X2 under the effect of a torque. of rotation generated by the inertial force resulting from the displacement of the moving assembly and more particularly of the piston and the cylinder.
  • crankpin 32 travels a semi-circular path for a phase, for example of admission, going from 0 ° to 180 ° then another semi-circular path (from 180 ° to 0 °) for another phase, as the compression phase.
  • the piston 14 goes from its top dead center to its bottom dead center and then from its bottom dead center to its top dead center.
  • this piston and the connecting rod 16 undergo an acceleration which increases as one of its dead centers approaches.
  • the inertial force When the force resulting from this acceleration, called the inertial force, is sufficient to overcome not only the weight of the piston 14 and the connecting rod 16 and / or the result of the gas pressures on the piston and the connecting rod but also the frictional forces between this piston and the wall of the cylinder bore, the latter generates an increase in speed of the piston rod assembly relative to that transmitted to this assembly by the crankpin. Therefore, if the movement of the eccentric is not hampered, there is an additional displacement of the piston and the rod compared to that induced by the crank pin. This movement takes place upwards when the piston is on the side of the top dead center and downwards when this piston is on the side of the bottom dead center.
  • the eccentric has a counterclockwise rotation movement to decrease the compression ratio during the stroke of the piston from its top dead center to its bottom dead center, and clockwise for an increase in the rate of compression during the stroke of this piston from its bottom dead center to its top dead center.
  • This eccentric comprises, preferably on its peripheral wall, a toothed sector 48, of angular extent SD, which cooperates, through an opening 50 provided in the connecting rod head 30, with a toothed bearing 52, of the rack type, provided on a slide 54 movable in rectilinear translation in a housing 56 carried by a support 58 connected to the connecting rod head 30.
  • this support is integrated into the lower half-bearing 60 which usually comprises the connecting rod head 30 and which is assembled by screws 62 to the other half-bearing 64 carried by the body of the connecting rod.
  • the slide 54 comprises a peripheral wall 66 of cylindrical section on which are placed seals 68 and this in the vicinity of its end faces 70 which preferably include axial recesses 72.
  • This peripheral wall is interrupted by the rack 52 which is substantially rectilinear and which extends over a large part of the length of this slide.
  • This rack has an extension in length which corresponds at least to the developed of the toothed sector 48 of the eccentric 42.
  • the housing 56 is of shape complementary to the cross section of that of the slide 54 and comprises two end walls 74. The distance between these two walls and the setting of the toothed sector of the eccentric relative to the toothed bearing of the slide are such that the total length of the slide to which is added the total travel of this slide, under the effect of the rotation of the eccentric , allows the geometric axis X1X1 of this slide to be located to the left of the cylinder axis, considering the figures, and this both at top dead center and bottom dead center of the piston.
  • the angular movement of this eccentric is of the order of 120 ° between its two extreme positions.
  • the midpoint M1 of the toothed sector of the eccentric is located mid-distance from point M2 of the length of the rack in such a way that the axis X1X1 of this eccentric is at the same height as the axis X2X2 of the crank pin at top dead center and bottom dead center of the piston. So from this position nominal, the eccentric turns anti-clockwise by an angle of approximately 60 ° to obtain a minimum compression rate which can be the nominal rate and arrived at the position of figure 3 and, for a maximum rate , rotates, always from this initial setting position, by an angle of approximately 60 ° clockwise to arrive at the position of figure 1.
  • the eccentric When the maximum rate is reached, the eccentric turns in the direction anti-clockwise by an angle of approximately 120 ° to reach the minimum rate and approximately 120 ° clockwise to obtain a maximum rate from its minimum rate.
  • the volumes delimited by the peripheral wall of the housing, its end walls and the end faces of the slider thus form two sealed fluid chambers, respectively 75a and 75b, which make it possible to authorize and control the movement of the slider in the housing.
  • a fluid cylinder 76 comprising the support 58 with its housing 56 in which the slide 54 moves, in a rectilinear manner, under the effect of the fluid present in the chambers 75a, 75b.
  • the variation device comprises a slide and a slide support separate from the eccentric. The relative position in translation of this slide, with respect to its support, is continuously kinematically linked to the angular movement of the eccentric relative to the rod by a kinematically reversible link.
  • This housing is connected to a control circuit 77, as shown in FIG. 4, which allows the rotation of the eccentric to be controlled by controlling the movement of the slide.
  • This control circuit comprises at least one closed circuit in which a fluid, for example oil, circulates.
  • the control circuit comprises two closed circuits 78a and 78b for which each closed circuit connects the two chambers 75a and 75b.
  • the chamber 75a is connected by a pipe 80a to a valve means 82a and more particularly to a 3-way valve, one of the tracks of which is connected to the pipe 80a and the other of the tracks of which is connected to a sheet 84a by a line 86a.
  • This valve is controlled by a means 88a, the actuation of which is dependent on the request for variation of the rate of compression.
  • a pipe 90a then connects the outlet of the valve 82a to a metering device 92a comprising a cylinder 94a with a sealed piston 96a movable inside this cylinder and which delimit two metering chambers 98a and 100a.
  • the chamber 98a is connected to the pipeline 90a while the chamber 100a, which comprises a spring 102a, is connected by a pipeline 104a to the fluid chamber 75b.
  • the pipes 80a and 104a carry non-return valves 106a and 108a respectively preventing a return of fluid in the chamber 75a and a fluid outlet from the chamber 75b.
  • this control circuit includes means for filling and purging circuits 78a and 78b.
  • These means include a hydraulic pump 110, pipes 112a, 112b each carrying a non-return valve and connected to pipes 104a, 104b, purge valves 114a and 114 connected to pipes 80a and 80b and purge devices 116a and 116b located on metering devices 92a and 92b.
  • the movement of the slide 54 to the left is controlled by the command to open the valve 82a which puts the fluid chamber 75a into communication with the metering chamber 98a via the pipes 80a and 90a.
  • the communication between the chambers 75a and 98a is closed and, on the other hand, the evacuation of the fluid present in the metering chamber 98a, under the impulse of the spring 102a, is authorized by pipes 90a and 86a to the cover 84a.
  • the volume of the metering chamber 98a is shaped in such a way that it corresponds to a determined value of displacement of the slide, called in the following description increment, this increment being able to be used in part or in total during displacement of this slide.
  • the volume of fluid coming from the fluid chamber 75a, during the displacement of the slide can be greater than this increment.
  • the command 88a commands several sequences of opening and closing of the valve 82a in order, sequentially, to fill and empty the chamber 98a while maintaining the slide in the position reached then commands to close this valve as soon as the eccentric has reaches the desired position.
  • the movement of the slide 54 in the opposite direction, that is to say to the right, is controlled in the same way but by acting on the various elements of the closed circuit 78b.
  • the hydraulic pump 110 fills, via the pipes 112a, 112b, the metering chambers 100a, 100b and the pipes 104a, 104b. Through these pipes, the fluid chambers 75a, 75b are also filled, as well as the pipes 80a, 80b through which the filling of the metering chambers 98a, 98b is ensured.
  • the purge valves 114a, 114b as well as the purges 116a, 116b are open to evacuate any air present in the circuits.
  • the pump and the pipes 112a, 112b will be used to compensate for any losses of fluid during the operation of the device.
  • the supply of fluid for filling the circuits is carried out by axial and radial bores 120 in the crankshaft and the crankpin, by a circumferential groove 122, between the bore of the eccentric 42 and the peripheral wall crankpin 34, for communication with the bores 120, and by radial bores 124 bringing the groove 122 into communication with the pipe 112 (respectively 112b) provided in the support 58.
  • This support also includes the control valves 82a and 82b, metering devices 92a and 92b, non-return valves 106 and 108 (respectively 108a), drain valves 114 (respectively 114a) and pipes 80, 90, 104
  • the compression rate variation device is in a determined configuration, as shown in FIG. 3 which corresponds, for example, to a minimum compression rate, which can be the nominal rate, and the piston 14 is in its bottom dead center position (PMBv) as illustrated in figure 2.
  • PMBv bottom dead center position
  • the PMBi is merged with the PMBv and the piston 14 has a stroke from this bottom dead center to its top dead center to carry out the phase for compressing the air or the fuel mixture present in the combustion chamber, as shown in FIG. 1.
  • the crankpin 34 travels a semi-circular path to go from its point low (180 °) at its high point (0 °).
  • control instructions are sent, by the computer, to control 88a of the 3-way valve 82a to put in communication, for a number of sequence, corresponding to an increment number and / or to an incremental part in displacement of the slide, and a duration determined by this computer, the fluid chamber 75a with the metering device 92a so as to allow the displacement of the slide by transfer fluid from one fluid chamber 75a to the other fluid chamber 75b via this metering device.
  • this slide Under the effect of the rotation of the eccentric and through the cooperation of the toothed sector 48 of the eccentric with the rack 52 of the slide, this slide has a movement to the left, to increase the compression ratio.
  • the fluid present in the chamber 98a of the metering device 92a is evacuated towards the tank 84a by the pipes 90a, 86a and the piston 96a of this metering device is found in the initial state, that is to say say close to line 90a.
  • the piston 14 performs an overtravel S with respect to its TDCI to be in the position illustrated in FIG. 1. In this position, the center distance between the axis 24 of the piston 14 and the axis of the crank pin increased and the piston 14 lengthened its initial stroke while exceeding the TDCI and entering the initial dead volume 40.
  • the computer sends instructions to the control 88b of the valve 82b of the circuit 78b so that the eccentric 42 either in the position illustrated in Figure 3 or in a position approaching this figure to reduce the compression ratio obtained in an earlier phase.
  • an engine operating phase is used during which the crankpin 34 goes from its position from 0 ° to 180 °, like the intake or expansion phase. During this phase, the forces as described above apply to the crankpin but in an opposite direction.
  • this slide Under the effect of the rotation of the eccentric generated by the force of inertia and by the cooperation of the toothed sector 48 of the eccentric with the toothed bearing 52 of the slide, this slide has a movement to the right to arrive at the position illustrated in Figure 3. Also, this movement of the slide is continuously controlled by action on the valve 82b which allows to obtain a multiplicity of angular positions of the eccentric during its movement counterclockwise and therefore a multiplicity of possibilities for reducing the piston overtravel, which has the effect of obtaining a multiplicity of possibilities for increasing the dead volume 118 to the initial dead volume 40.
  • this device for varying the rate of compression it is not only possible to obtain a multiplicity of possibilities for increasing the compression rate but also a multiplicity of possibilities of reducing this rate from a rate which has undergone an increase.
  • each 3-way valve is replaced by two piezoelectric devices 126 (respectively 126b) which make it possible to improve the response time and consequently increase the precision of the adjustment. compression ratio.
  • Each of these devices comprises a needle 128 subjected to the action of a piezoelectric actuator 130 and constitutes a two-way valve.
  • One of these piezoelectric devices controls the passage of the fluid between the pipe 80 (respectively 80b) and the pipe 90 and the other of the piezoelectric devices controls the passage of the fluid between the pipe 90 (respectively 90b) and the pipe 86.
  • the support 58 carries two electrical pads 132 connected by electrical conductors (not shown) to this actuator.
  • Electrical tracks 134 are carried by a fixed element of the engine, such as the motor casing, and are arranged in such a way that they are continuously facing the studs 132 at least for a displacement of the crankpin from its point to 0 ° at its point located at 180 °, as illustrated in Figures 6a to 6d. Of course, without departing from the scope of the invention, these tracks can extend over the entire rotation of the crankpin of 360 °.
  • connection of the fluid passage between the fluid chamber 75a, 75b and the metering chamber 98a, 98b is produced by a first 2-way valve made up of a piezoelectric device
  • connection of the fluid passage between the metering chamber 98a, 98b and the tank 84a, 84b is made by another 2-way valve made up of a piezoelectric device
  • an electric current is sent into the tracks 134 to control the opening of the needle 128 during the request for variation of the compression rate.
  • a single circuit comprising a pipe connecting the chamber 75a with a valve means, such as the 3-way valve, which would then be replaced by a 2-way valve or the piezoelectric device described above. , and a pipe connecting the valve means with the other fluid chamber 75b.
  • the filling means with their hydraulic pump and the pipes connecting with the pipe connecting the valve means to the chamber 75b, as well as the purge valves can also be provided on this single circuit.
  • a means for locating the angular position of the eccentric 42, as illustrated in FIGS. 7a to 7d.
  • This means comprises a signal transmitter-receiver assembly 136, one of the elements of which is carried by the eccentric 42 and the other of the elements of which is carried by a fixed element of the motor, such as a lug 138 originating from a wall. of this housing.
  • the eccentric carries an index 140 which emits a signal by radiation, for example by magnetic radiation
  • the tab 138 carries a receiver formed by a reading sector 142 of the signal emitted by the index 140 and which makes it possible to know the position of this index during the rotation of the crankpin 34.
  • This reading sector is substantially in an arc, the concavity of which is directed towards the crankshaft, with a substantially constant radial thickness E.
  • This sector comprises a first reading region 144 located in its upper part for reading the signal emitted by the index 140 when the compression ratio is maximum or is increased and a second region 146 placed in the lower part of this sector for reading of the signal emitted by the index 140 when the compression ratio is nominal or is reduced.
  • the computer that this engine usually includes determines the angular setting C of the eccentric relative to the longitudinal axis of the connecting rod ( Figure 7a) to obtain a defined compression ratio when the piston is at top dead center.
  • the latter takes into account the intensity of the signal received by the reading region 144.
  • this signal is at most high when the emission point 148 of the index 140 is situated substantially in the middle of the thickness E of this reading region and corresponds to a maximum compression ratio.
  • the different values of the compression ratio can be controlled by taking into account the position of the emission point 148 of the index 140 relative to the middle of the thickness E of this reading region. Therefore, one of the closed circuits 78a, 78b will be operational so that the slider 54 moves to allow an angular movement of the eccentric 42 allowing such a positioning of the emission point 148 to be obtained.
  • this computer determines the angular setting Ci (FIG. 7d) of the eccentric relative to the longitudinal axis of the connecting rod, when the piston is in bottom dead center, in order to obtain a nominal compression ratio or to decrease the ratio compression obtained in a previous phase.
  • this computer takes into account the strength of the signal received by the reading region 146 and, as previously mentioned, this signal is at its highest when the point of emission of the index 140 is located substantially in the middle of the thickness E of this region.
  • the circuits 78a, 78b will be actuated in such a way that the slider can allow an angular movement of the eccentric making it possible to obtain such an angular setting.
  • this reading sector 142 comprises conductive wires isolated from each other and arranged substantially radially with respect to its shape in an arc of a circle over its thickness E. These conductive wires constitute a plurality of receivers of the signals emitted by the index 140 , angularly distributed from the upper part of the reading sector 142 to its lower part.
  • the index 140 describes at each rotation of the crankshaft a substantially circular curve of radius smaller than the radius of the substantially circular shape of the reading sector 142.
  • the substantially circular curve described by the index 140 translates as a function of the angular setting of the eccentric 42.
  • the radius of the reading sector 142 and its position are such that the index 140 comes opposite the conductive wires of the thickness E of the reading sector 142 according to an arc of a circle whose position is characteristic of the angular setting of the eccentric 42.
  • knowing the identity of the conducting wires on the thickness E of the reading sector informed by the index 140 during the rotation of the crankshaft makes it possible to know the angular position of the eccentric with a precision which depends on the pitch of the conducting wires.
  • the reading accuracy of the angular setting of the eccentric 42 is improved by the combined reading of the position and the intensity of the signals perceived by the conducting wires informed by the index 140 during the rotation of the crankshaft.
  • the index 140 When the index 140 is completely opposite the thickness E of the reading sector 142, for example in FIGS. 7a and 7d, at least one of the conducting wires receives a maximum information signal from the index 140.
  • the informed wires When index 140 is partially opposite the thickness E of the reading sector 142, for example for FIG. 7b, the informed wires receive a weaker signal from the index 140.
  • provision will be made to gradually and continuously decrease the compression ratio by increasing the angular setting from C to Ci and vice versa to increase it from Ci to C, and this, engine combustion cycle by engine combustion cycle.
  • the present invention is not limited to the embodiments described but encompasses all variants and equivalents.
  • the device for varying the compression ratio is placed at the level of the connecting rod end 26 with an eccentric carried by the axis 24 of the piston 14.

Abstract

The device (32) has a cam (42) housed between a crank pin (34) and a hole (44) provided in a connecting rod head (30). The cam has circular shape with geometric axis of the cam corresponding to its center axis, and a hole (46) with axis non coaxial with the geometric axis and merged with axis of the crank pin. The cam permits to vary compression rate of an internal combustion engine. An independent claim is also included for a method for varying compression rate of an internal combustion engine.

Description

Dispositif de variation du taux de compression d'un moteur à combustion interne et procédé pour utiliser un tel dispositif- La présente invention se rapporte à un dispositif de variation du taux de compression d'un moteur à combustion interne et à un procédé permettant l'utilisation d'un tel dispositif. Elle concerne plus particulièrement un dispositif qui peut changer le taux de compression de ce moteur en modifiant le volume mort de la chambre de combustion au point mort haut du piston. Device for varying the compression ratio of an internal combustion engine and method for using such a device The present invention relates to a device for varying the compression ratio of an internal combustion engine and a method allowing the use of such a device. It relates more particularly to a device which can change the compression ratio of this engine by modifying the dead volume of the combustion chamber at the top dead center of the piston.
Il est déjà connu, par le document EP 0 297 904, un dispositif de variation du taux de compression d'un moteur dans lequel ce moteur comprend un vilebrequin, un cylindre à l'intérieur duquel un piston coulisse dans un mouvement translatif alternatif par l'intermédiaire d'une bielle reliée audit piston et audit vilebrequin, ce piston délimitant avec le haut du cylindre une chambre de combustion comportant un volume mort au point mort haut (PMH) de ce piston, et un excentrique rotatif, de type tracté, intercalé entre la bielle et le piston. Cet excentrique, dans une première position, permet au piston de réduire le volume mort de la chambre de combustion tout en augmentant le taux de compression et d'augmenter ce volume mort, pour une autre position de cet excentrique, tout en obtenant un taux de compression plus faible. Pour ce faire, l'excentrique présente une rainure prévue pour coopérer avec deux goupilles de verrouillage disposées chacune symétriquement par rapport à l'axe du piston permettant d'immobiliser l'excentrique dans l'une ou l'autre de ses positions.It is already known, from document EP 0 297 904, a device for varying the compression ratio of an engine in which this engine comprises a crankshaft, a cylinder inside which a piston slides in an alternating translational movement by the intermediary of a connecting rod connected to said piston and to said crankshaft, this piston delimiting with the top of the cylinder a combustion chamber comprising a dead volume at top dead center (TDC) of this piston, and a rotary eccentric, of towed type, interposed between the connecting rod and the piston. This eccentric, in a first position, allows the piston to reduce the dead volume of the combustion chamber while increasing the compression rate and to increase this dead volume, for another position of this eccentric, while obtaining a rate of lower compression. To do this, the eccentric has a groove intended to cooperate with two locking pins each arranged symmetrically with respect to the axis of the piston making it possible to immobilize the eccentric in one or the other of its positions.
Ce dispositif bien que donnant satisfaction présente néanmoins de nombreux inconvénients. L'un des inconvénients d'un tel dispositif réside essentiellement dans le manque de souplesse des possibilités du réglage du taux de compression qui ne comporte que deux possibilités de variation de ce taux. De plus, un tel dispositif nécessite un ajustage précis entre la rainure et la goupille pour éviter tous phénomènes de blocage de la goupille dans la rainure.This device, although satisfactory, nevertheless presents numerous drawbacks. One of the drawbacks of such a device essentially lies in the lack of flexibility in the possibilities of adjusting the compression ratio which only comprises two possibilities of variation of this ratio. In addition, such a device requires a precise adjustment between the groove and the pin to avoid any phenomena of blocking of the pin in the groove.
Dans un autre type de dispositif de variation du taux de compression, comme mieux décrit dans la demande de brevet DE-A- 42 26 361 , l'excentrique n'est pas un excentrique de type tracté mais un excentrique motorisé grâce à la coopération d'un secteur denté de cet excentrique avec une vis sans fin. Ce dispositif présente un inconvénient majeur dans le sens que la vis sans fin doit être motorisée pour commander la rotation de cet excentrique. Cette motorisation est d'un encombrement volumineux et nécessite des fortes puissances pour vaincre l'inertie de l'équipage mobile et les différents frottements.In another type of device for varying the compression ratio, as better described in patent application DE-A-42 26 361, the eccentric is not an eccentric of the towed type but a motorized eccentric thanks to the cooperation of 'a toothed sector of this eccentric with a worm. This device has a major drawback in the sense that the worm must be motorized to control the rotation of this eccentric. This motorization is bulky and requires high powers to overcome the inertia of the moving part and the various frictions.
La présente invention se propose de remédier aux inconvénients ci- dessus mentionnés grâce à un dispositif de variation du taux de compression de conception simple et peu encombrant qui permet d'accroître les possibilités de variation du taux de compression.The present invention proposes to overcome the above-mentioned drawbacks by means of a device for varying the compression ratio of simple and space-saving design which makes it possible to increase the possibilities of variation of the compression ratio.
A cet effet, la présente invention concerne un dispositif de variation du taux de compression d'un moteur à combustion interne comprenant au moins un cylindre avec une chambre de combustion, un équipage mobile comportant un piston déplaçable en translation sous l'action d'une bielle liée par un axe audit piston et raccordée à un maneton d'un vilebrequin, ledit piston effectuant une course entre un point mort haut et un point mort bas en laissant subsister un volume mort au point mort haut dudit piston, le dispositif comprenant un excentrique tracté rotatif permettant de faire varier le taux de compression et des moyens de contrôle du déplacement de l'excentrique, caractérisé en ce que les moyens de contrôle comprennent un vérin fluidique comportant un coulisseau placé dans un logement formé dans un support et délimitant deux chambres fluidiques en communication avec au moins un circuit fermé. Les chambres fluidiques peuvent être en communication l'une avec l'autre par au moins un circuit fermé. .To this end, the present invention relates to a device for varying the compression ratio of an internal combustion engine comprising at least one cylinder with a combustion chamber, a movable assembly comprising a piston displaceable in translation under the action of a connecting rod connected by an axis to said piston and connected to a crankpin of a crankshaft, said piston making a stroke between a top dead center and a bottom dead center while leaving a dead volume at the top dead center of said piston, the device comprising an eccentric rotary tractor for varying the compression ratio and means for controlling the movement of the eccentric, characterized in that the control means comprise a fluid cylinder comprising a slide placed in a housing formed in a support and delimiting two fluid chambers in communication with at least one closed circuit. The fluid chambers can be in communication with each other by at least one closed circuit. .
Le circuit fermé peut comprendre au moins un moyen de vannage permettant de. contrôler le débit de fluide d'une chambré vers l'autre.The closed circuit may include at least one valve means making it possible to. control the flow of fluid from one chamber to the other.
Avantageusement, le moyen de vannage peut être une vanne à au moins , 2 voies. ' De manière préférentielle, le moyen de vannage peut être un dispositif piézoélectrique.Advantageously, the valve control means can be a valve with at least two channels. Preferably, the valve means can be a piezoelectric device.
Le dispositif piézoélectrique peut comprendre un pointeau et un actionneur piézoélectrique.The piezoelectric device may include a needle and a piezoelectric actuator.
Le dispositif piézoélectrique peut être commandé par coopération de plots et de pistes électriques.The piezoelectric device can be controlled by cooperation of pads and electrical tracks.
Le circuit peut comprendre au moins un dispositif doseur situé en aval du moyen de vannage.The circuit may include at least one metering device located downstream of the valve means.
Le dispositif doseur peut comprendre un ensemble piston-cylindre avec un ressort de tarage. Les éléments du circuit fermé peuvent être au moins en partie logés dans le vérin.The metering device may include a piston-cylinder assembly with a calibration spring. The elements of the closed circuit can be at least partially housed in the jack.
Le dispositif de variation peut comprendre des moyens de localisation de la position de l'excentrique.The variation device may include means for locating the position of the eccentric.
Les moyens de localisation peuvent comprendre un ensemble émetteur- récepteur de signaux. L'excentrique peut comprendre l'émetteur et le récepteur peut être logé sur une partie fixe du moteur. L'excentrique peut comprendre des moyens à coopération de forme avec le coulisseau.The location means may include a transmitter-receiver assembly of signals. The eccentric may include the transmitter and the receiver may be housed on a fixed part of the motor. The eccentric may include means for form cooperation with the slide.
Les moyens de coopération peuvent comprendre un secteur denté porté par l'excentrique et une portée dentée portée par le coulisseau.The cooperation means may include a toothed sector carried by the eccentric and a toothed bearing carried by the slide.
L'invention concerne aussi un procédé de variation du taux de compression d'un moteur à combustion interne, ledit moteur comprenant au moins un cylindre avec une chambre de combustion, un équipage mobile comportant un piston mobile en translation sous l'action d'une bielle liée par un axe audit piston et raccordée à un maneton d'un vilebrequin, ledit piston effectuant une course entre un point mort haut et un point mort bas en laissant subsister un volume mort au point mort haut dudit piston, caractérisé en ce que le procédé consiste à : - déterminer le taux de compression souhaité du moteur, - déterminer l'étendue du déplacement d'un excentrique tracté rotatif pour obtenir le taux de compression souhaité, - contrôler la rotation de l'excentrique pour obtenir le déplacement déterminé. Un avantage de la présente invention par rapport aux dispositifs de l'état de la technique réside dans le fait que la déperdition énergétique de la fonction palier entre la bielle et le maneton du vilebrequin est moindre. En effet, lorsque le taux de compression ne varie pas, la position de l'excentrique par rapport à la bielle est fixe et la fonction palier entre la bielle et le maneton est réalisée par le déplacement relatif entre l'excentrique et le maneton du vilebrequin. De ce fait, la fonction palier entre la bielle et le vilebrequin est réalisée avec un diamètre de palier moindre, ce qui est un avantage non négligeable car comme cela est connu la déperdition énergétique d'un palier, pour une charge donnée dans des conditions normales de fonctionnement, est une fonction croissante de son diamètre. Un autre avantage de la présente invention est un contrôle plus aisé de l'ajustement du taux de compression. En effet, la présente invention utilise une liaison cinématique réversible qui lie continûment le débattement angulaire de l'excentrique à la translation du coulisseau. De ce fait, le calage angulaire de l'excentrique et par voie de conséquence l'ajustement du taux de compression, est une fonction continue de la position en translation du coulisseau définie par la construction mécanique du dispositif selon l'invention. Donc, à aucun moment le taux de compression ne peut varier sans que la position en translation du coulisseau ne soit modifiée et grâce au dispositif hydraulique de la présente invention le contrôle de la position du coulisseau est obtenu aisément. D'autres avantages supplémentaires de la présente invention sont une moindre déperdition énergétique, une plus grande précision et une plus grande durée de vie. En effet, la présente invention utilise une liaison cinématique réversible pour lier continûment le débattement angulaire de l'excentrique à la translation du coulisseau. Du fait de la réversibilité de la liaison cinématique, les frottements dans cette liaison peuvent être minimisés par construction. Grâce à cela, la déperdition énergétique par frottement de cette liaison, l'usure de cette liaison et l'amplitude des phénomènes d'hystérésis peuvent être tous les trois moindres. De plus, l'abaissement de l'amplitude du phénomène d'hystérésis conduit à une meilleure précision de l'ajustement du taux de compression. En outre, du fait de sa réversibilité, la liaison cinématique de la présente invention ne présente pas de risque de coincement. Cette réversibilité peut être obtenue grâce à un secteur denté, placé de préférence sur la paroi périphérique de l'excentrique, qui coopère au travers d'une ouverture prévue dans la tête de bielle, avec une portée dentée, de type crémaillère, prévue dans un coulisseau mobile dans un logement porté par un support relié à la tête de bielle. Ce coulisseau a un déplacement tangentiel à la circonférence dudit excentrique. Encore un autre avantage de la présente invention réside dans une plus grande simplicité d'intégration du dispositif dans le moteur et dans son environnement. En effet, la présente invention utilise un excentrique logé entre le maneton du vilebrequin et l'alésage de la tête de bielle. De ce fait, la distance entre l'axe du vilebrequin et les différents périphériques du moteur, l'arbre à cames, le démarreur, l'alternateur, la pompe à eau, etc. ne varie pas et donc ne conduit pas à des dispositifs supplémentaires spécifiques pour compenser les variations de distances entre le vilebrequin et ces différents périphériques du moteur. De même, l'alignement entre le vilebrequin et la transmission ne change pas. Grâce à la présente invention, il n'est donc pas nécessaire d'utiliser de dispositif spécifique pour compenser les variations d'alignement entre le moteur et la transmission à laquelle il est accouplé. De plus, le dispositif de la présente invention permet d'avoir un poids et un encombrement moindres ainsi qu'une plus grande réactivité de l'ajustement du taux de compression. En effet, du fait que l'excentrique est tracté, l'ajustement du taux de compression ne nécessite pas de moteur d'entraînement de l'excentrique et le dispositif n'est donc pas pénalisé par le poids, par l'encombrement et par les temps de réponses d'un moteur spécifique et de ses liaisons cinématiques pour entraîner en rotation l'excentrique afin d'ajuster le taux de compression. En outre, ce dispositif a encore d'autres avantages comme la compatibilité avec une distance plus courte entre l'axe du vilebrequin et la culasse du moteur, des vibrations moindres et un coût de réalisation moindre. En effet, le vérin dont la fonction est de contrôler la position de l'excentrique placé entre la tête de bielle et le maneton du vilebrequin est distinct dudit excentrique, notamment son coulisseau est distinct de toutes les autres pièces et est mobile par rapport à toutes ces autres pièces. Grâce à cela un large choix d'orientation dudit vérin par rapport à la bielle est permis, ce qui optimise simultanément la distance entre l'axe du vilebrequin et la culasse ainsi que les vibrations induites par l'équipage mobile et également les formes pour réduire les coûts de fabrication. Les autres caractéristiques et avantages de l'invention vont apparaître à la lecture de la description qui va suivre, donnée à titre uniquement illustratif et non limitatif, et à laquelle sont annexés : - la figure 1 qui montre, en coupe axiale, un moteur à combustion interne avec le dispositif de variation du taux de compression selon l'invention dans une première position, - la figure 2 est une autre vue, en coupe axiale, montrant le moteur à combustion interne avec le dispositif de la figure 1 dans une autre position et dans une autre configuration, - la figure 3 est une vue de détail dans une position extrême du dispositif de l'invention de la figure 1 , - la figure 4 est un schéma montrant le circuit de commande utilisé pour le dispositif selon l'invention, - la figure 5 est une autre vue de détail du dispositif montrant les différents éléments du circuit de commande portés par le dispositif selon l'invention, - la figure 6a est une autre vue de détail du dispositif montrant une variante d'un des éléments du circuit de commande du dispositif selon l'invention alors que les figures 6b à 6d sont une illustration des différentes positions de ce dispositif pendant la rotation du vilebrequin et - les figures 7a à 7d sont une autre illustration d'un dispositif de localisation de la position angulaire de l'un des éléments du dispositif de variation du taux de compression selon l'invention. On se rapporte aux figures 1 à 3 qui montrent un moteur à combustion interne avec au moins un cylindre 10 qui comprend un alésage 12 à l'intérieur duquel coulisse un piston creux 14 dans un mouvement translatif alternatif sous l'impulsion d'une bielle 16. Ce piston délimite avec sa partie haute, la paroi latérale de l'alésage 12 et la partie haute de cet alésage, généralement formée par une partie de la culasse 18, une chambre de combustion 20 dans laquelle se déroule le cycle de combustion. Le piston porte deux alésages radiaux diamétralement opposés 22 au travers desquels est logé un axe cylindrique 24 qui relie une extrémité 26 de la bielle, dite pied de bielle, audit piston en traversant, à glissement, un alésage 28 prévu dans le pied de bielle. L'autre extrémité 30 de la bielle, appelée tête de bielle, est reliée par un dispositif de variation du taux de compression 32 à un maneton 34 d'un vilebrequin 36. Ce vilebrequin est soumis à un mouvement de rotation autour d'un axe XX de manière à ce que le maneton 34 suive un cheminement circulaire 38 autour de l'axe XX. Comme cela est connu, le piston 14, l'axe de liaison 24, la bielle 16, le vilebrequin 36 avec son maneton 34 forment l'équipage mobile du moteur. Dans les moteurs conventionnels, pendant le mouvement de rotation du vilebrequin 36 comme les phases d'admission et de détente, le maneton 34 passe successivement d'une position haute, indiquée 0° sur la figure 1 , à une position basse, indiquée 180°. Pendant ce mouvement, le piston 14, qui est relié au maneton 34 par la bielle 16, subit un mouvement translatif alternatif entre un point mort haut initial (référencé P Hi sur la figure 1) qui correspond à la position haute du maneton et un point mort bas initial (référencé PMBi sur la figure 2) correspondant à la position basse du maneton. Ainsi, le piston 14 a une course initiale entre son PMHi et son PMBi. Dans ces moteurs, lorsque le piston est au PMHi, soit à la fin de la phase de compression, soit à la fin de la phase d'échappement, il subsiste un volume mort 40 dans la chambre de combustion 20. Ce volume est nécessaire pour le fonctionnement du moteur pendant ses phases de compression, de combustion et de détente. Comme le sait pertinemment l'homme du métier, le taux de compression d'un moteur est une fonction non seulement de l'étendue du volume du cylindre délimité par la course du piston mais aussi de l'ampleur du volume mort. Pour modifier le taux de compression, il suffit de modifier l'un de ces volumes et plus particulièrement la grandeur du volume mort. Pour ce faire, le dispositif de variation de taux de compression 32 comprend un excentrique 42 logé entre le maneton 34 et un alésage 44 prévu dans la tête de bielle 30. Cet excentrique a une forme générale circulaire avec un axe géométrique X1X1 qui correspond à son axe milieu et comprend un alésage 46 d'axe X2X2 non coaxial avec l'axe X1X1 mais confondu avec l'axe du maneton 34. Cet excentrique est logé à glissement dans l'alésage de réception 44 réalisé dans la tête de bielle et sur la paroi périphérique du maneton 34. Cet excentrique est dit tracté car, pendant le fonctionnement du moteur, il est susceptible d'être entraîné en rotation autour de l'axe X2X2 sous l'effet d'un couple de rotation généré par la force d'inertie résultant du déplacement de l'équipage mobile et plus particulièrement du piston et du cylindre. En effet, le maneton 32 parcourt un chemin semi-circulaire pour une phase, par exemple d'admission, allant de 0° à 180° puis un autre chemin semi- circulaire (de 180° à 0°) pour une autre phase, comme la phase de compression. Pendant ces cheminements, le piston 14 va de son point mort haut à son point mort bas puis de son point mort bas vers son point mort haut. Pendant ce mouvement, ce piston et la bielle 16 subissent une accélération qui augmente au fur et à mesure du rapprochement de l'un de ses points morts. Lorsque la force résultante de cette accélération, dite force d'inertie, est suffisante pour vaincre non seulement le poids du piston 14 et de la bielle 16 et/ou la résultante des pressions gazeuses sur le piston et la bielle mais aussi les forces de frottement entre ce piston et la paroi de l'alésage du cylindre, celle-ci génère une augmentation de vitesse de l'ensemble piston bielle par rapport à celle transmise à cet ensemble par le maneton. De ce fait, si le débattement de l'excentrique n'est pas entravé, il se produit un déplacement supplémentaire du piston et de la bielle par rapport à celui induit par le maneton. Ce déplacement a lieu vers le haut lorsque le piston est du coté du point mort haut et vers le bas lorsque ce piston est du coté du point mort bas. Cet entraînement supplémentaire peut être rendu possible grâce à la rotation, autour de l'axe X2X2, de l'excentrique 42 relié à la bielle 16. Ainsi, comme cela est représenté à titre d'exemple sur les figures 1 à 3, l'excentrique a un mouvement de rotation dans un sens anti-horaire pour une diminution du taux de compression lors de la course du piston de son point mort haut vers son point mort bas, et dans un sens horaire pour une augmentation du taux de compression lors de la course de ce piston de son point mort bas vers son point mort haut.The invention also relates to a method of varying the compression ratio of an internal combustion engine, said engine comprising at least one cylinder with a combustion chamber, a movable assembly comprising a piston movable in translation under the action of a connecting rod connected by an axis to said piston and connected to a crankpin of a crankshaft, said piston making a stroke between a top dead center and a bottom dead center while leaving a dead volume at the top dead center of said piston, characterized in that the method consists in: - determining the desired compression ratio of the motor, - determining the extent of displacement of a rotary towed eccentric to obtain the desired compression ratio, - controlling the rotation of the eccentric to obtain the determined displacement. An advantage of the present invention over the devices of the prior art lies in the fact that the energy loss of the bearing function between the connecting rod and the crankpin of the crankshaft is less. In fact, when the compression ratio does not vary, the position of the eccentric relative to the connecting rod is fixed and the bearing function between the connecting rod and the crankpin is achieved by the relative displacement between the eccentric and the crankpin of the crankshaft . Therefore, the bearing function between the connecting rod and the crankshaft is achieved with a smaller bearing diameter, which is a significant advantage because as it is known the energy loss of a bearing, for a given load under normal operating conditions, is an increasing function of its diameter. Another advantage of the present invention is easier control of the adjustment of the compression ratio. In fact, the present invention uses a reversible kinematic link which continuously links the angular movement of the eccentric to the translation of the slide. Therefore, the angular setting of the eccentric and consequently the adjustment of the compression ratio, is a continuous function of the position in translation of the slide defined by the mechanical construction of the device according to the invention. Therefore, at no time can the compression ratio vary without the translational position of the slider being modified and, thanks to the hydraulic device of the present invention, control of the position of the slider is easily obtained. Other additional advantages of the present invention are lower energy loss, greater precision and longer service life. Indeed, the present invention uses a reversible kinematic connection to continuously link the angular movement of the eccentric to the translation of the slide. Due to the reversibility of the kinematic connection, the friction in this connection can be minimized by construction. Thanks to this, the energy loss by friction of this connection, the wear of this connection and the amplitude of the hysteresis phenomena can be all three less. In addition, the lowering of the amplitude of the hysteresis phenomenon leads to a better precision of the adjustment of the compression ratio. In addition, due to its reversibility, the kinematic connection of the present invention does not present a risk of jamming. This reversibility can be obtained thanks to a toothed sector, preferably placed on the peripheral wall of the eccentric, which cooperates through an opening provided in the connecting rod head, with a toothed bearing, of the rack type, provided in a movable slide in a housing carried by a support connected to the connecting rod head. This slide has a tangential displacement at the circumference of said eccentric. Yet another advantage of the present invention lies in a greater simplicity of integration of the device in the engine and in its environment. Indeed, the present invention uses an eccentric housed between the crankpin of the crankshaft and the bore of the big end. Therefore, the distance between the crankshaft axis and the various engine peripherals, the camshaft, the starter, the alternator, the water pump, etc. does not vary and therefore does not lead to specific additional devices to compensate for variations in distances between the crankshaft and these various engine peripherals. Likewise, the alignment between the crankshaft and the transmission does not change. Thanks to the present invention, it is therefore not necessary to use a specific device to compensate for variations in alignment between the engine and the transmission to which it is coupled. In addition, the device of the present invention makes it possible to have a reduced weight and bulk as well as greater responsiveness in adjusting the compression ratio. In fact, because the eccentric is towed, the adjustment of the compression ratio does not require a motor for driving the eccentric and the device is therefore not penalized by the weight, by the size and by the response times of a specific engine and its kinematic connections to drive the eccentric in rotation in order to adjust the compression ratio. In addition, this device has other advantages such as compatibility with a shorter distance between the axis of the crankshaft and the cylinder head of the engine, less vibration and a lower production cost. Indeed, the jack whose function is to control the position of the eccentric placed between the connecting rod head and the crankshaft crankpin is distinct from said eccentric, in particular its slide is distinct from all the other parts and is movable relative to all these other pieces. Thanks to this, a wide choice of orientation of said jack with respect to the connecting rod is allowed, which simultaneously optimizes the distance between the axis of the crankshaft and the cylinder head as well as the vibrations induced by the movable assembly and also the shapes for reducing manufacturing costs. The other characteristics and advantages of the invention will appear on reading the description which follows, given by way of illustration only and without limitation, and to which are appended: - Figure 1 which shows, in axial section, a motor with internal combustion with the device for varying the compression ratio according to the invention in a first position, - Figure 2 is another view, in axial section, showing the internal combustion engine with the device of Figure 1 in another position and in another configuration, - Figure 3 is a detail view in an extreme position of the device of the invention of Figure 1, - Figure 4 is a diagram showing the control circuit used for the device according to the invention , - Figure 5 is another detail view of the device showing the various elements of the control circuit carried by the device according to the invention, - Figure 6a is another detail view of the available sitive showing a variant of one of the elements of the control circuit of the device according to the invention while FIGS. 6b to 6d are an illustration of the different positions of this device during the rotation of the crankshaft and - FIGS. 7a to 7d are another illustration of a device for locating the angular position of one of the elements of the device for varying the compression ratio according to the invention. Referring to Figures 1 to 3 which show an internal combustion engine with at least one cylinder 10 which comprises a bore 12 inside which slides a hollow piston 14 in an alternating translational movement under the impulse of a connecting rod 16 This piston defines with its upper part, the side wall of the bore 12 and the upper part of this bore, generally formed by a part of the cylinder head 18, a combustion chamber 20 in which the combustion cycle takes place. The piston carries two diametrically opposite radial bores 22 through which is housed a cylindrical axis 24 which connects one end 26 of the connecting rod, known as the connecting rod foot, to said piston by passing, by sliding, a bore 28 provided in the connecting rod foot. The other end 30 of the connecting rod, called the connecting rod head, is connected by a device for varying the compression ratio 32 to a crankpin 34 of a crankshaft 36. This crankshaft is subjected to a rotational movement about an axis XX so that the crankpin 34 follows a circular path 38 around the axis XX. As is known, the piston 14, the connecting pin 24, the connecting rod 16, the crankshaft 36 with its crankpin 34 form the movable assembly of the engine. In conventional engines, during the rotational movement of the crankshaft 36 like the intake and expansion phases, the crankpin 34 passes successively from a high position, indicated 0 ° in FIG. 1, to a low position, indicated 180 ° . During this movement, the piston 14, which is connected to the crankpin 34 by the connecting rod 16, undergoes a reciprocating translational movement between an initial top dead center (referenced P Hi in FIG. 1) which corresponds to the top position of the crankpin and a point initial low dead (referenced PMBi in Figure 2) corresponding to the low position of the crankpin. Thus, the piston 14 has an initial stroke between its PMHi and its PMBi. In these engines, when the piston is at TDCI, either at the end of the compression phase or at the end of the exhaust phase, there remains a dead volume 40 in the combustion chamber 20. This volume is necessary for engine operation during its compression, combustion and expansion phases. As a person skilled in the art knows, the compression ratio of an engine is a function not only of the extent of the volume of the cylinder delimited by the stroke of the piston but also of the extent of the dead volume. To modify the compression ratio, it suffices to modify one of these volumes and more particularly the magnitude of the dead volume. To do this, the compression ratio variation device 32 comprises an eccentric 42 housed between the crank pin 34 and a bore 44 provided in the connecting rod head 30. This eccentric has a generally circular shape with a geometric axis X1X1 which corresponds to its middle axis and comprises a bore 46 of axis X2X2 not coaxial with the axis X1X1 but coincident with the axis of the crank pin 34. This eccentric is housed in sliding in the receiving bore 44 produced in the big end and on the peripheral wall of the crankpin 34. This eccentric is said to be towed because, during the operation of the engine, it is likely to be driven in rotation around the axis X2X2 under the effect of a torque. of rotation generated by the inertial force resulting from the displacement of the moving assembly and more particularly of the piston and the cylinder. Indeed, the crankpin 32 travels a semi-circular path for a phase, for example of admission, going from 0 ° to 180 ° then another semi-circular path (from 180 ° to 0 °) for another phase, as the compression phase. During these paths, the piston 14 goes from its top dead center to its bottom dead center and then from its bottom dead center to its top dead center. During this movement, this piston and the connecting rod 16 undergo an acceleration which increases as one of its dead centers approaches. When the force resulting from this acceleration, called the inertial force, is sufficient to overcome not only the weight of the piston 14 and the connecting rod 16 and / or the result of the gas pressures on the piston and the connecting rod but also the frictional forces between this piston and the wall of the cylinder bore, the latter generates an increase in speed of the piston rod assembly relative to that transmitted to this assembly by the crankpin. Therefore, if the movement of the eccentric is not hampered, there is an additional displacement of the piston and the rod compared to that induced by the crank pin. This movement takes place upwards when the piston is on the side of the top dead center and downwards when this piston is on the side of the bottom dead center. This additional drive can be made possible by the rotation, around the axis X2X2, of the eccentric 42 connected to the connecting rod 16. Thus, as shown by way of example in Figures 1 to 3, the eccentric has a counterclockwise rotation movement to decrease the compression ratio during the stroke of the piston from its top dead center to its bottom dead center, and clockwise for an increase in the rate of compression during the stroke of this piston from its bottom dead center to its top dead center.
Cet excentrique comprend, de préférence sur sa paroi périphérique, un secteur denté 48, d'étendue angulaire SD, qui coopère, au travers d'une ouverture 50 prévue dans la tête de bielle 30, avec une portée dentée 52, de type crémaillère, prévue sur un coulisseau 54 mobile en translation rectiligne dans un logement 56 porté par un support 58 relié à la tête de bielle 30. De préférence, ce support est intégré au demi-palier inférieur 60 que comporte habituellement la tête de bielle 30 et qui est assemblé par des vis 62 à l'autre demi-palier 64 porté par le corps de la bielle. Le coulisseau 54 comprend une paroi périphérique 66 de section cylindrique sur laquelle sont placés des joints d'étanchéité 68 et cela au voisinage de ses faces terminales 70 qui comportent, de manière préférentielle, des embrèvements axiaux 72. Cette paroi périphérique est interrompue par la crémaillère 52 qui est sensiblement rectiligne et qui s'étend sur une grande partie de la longueur de ce coulisseau.This eccentric comprises, preferably on its peripheral wall, a toothed sector 48, of angular extent SD, which cooperates, through an opening 50 provided in the connecting rod head 30, with a toothed bearing 52, of the rack type, provided on a slide 54 movable in rectilinear translation in a housing 56 carried by a support 58 connected to the connecting rod head 30. Preferably, this support is integrated into the lower half-bearing 60 which usually comprises the connecting rod head 30 and which is assembled by screws 62 to the other half-bearing 64 carried by the body of the connecting rod. The slide 54 comprises a peripheral wall 66 of cylindrical section on which are placed seals 68 and this in the vicinity of its end faces 70 which preferably include axial recesses 72. This peripheral wall is interrupted by the rack 52 which is substantially rectilinear and which extends over a large part of the length of this slide.
Cette crémaillère a une étendue en longueur qui correspond au moins au développé du secteur denté 48 de l'excentrique 42. Le logement 56 est de forme complémentaire à la section transversale de celle du coulisseau 54 et comprend deux parois extrêmes 74. La distance entre ces deux parois et le calage du secteur dentée de l'excentrique par rapport à la portée dentée du coulisseau sont tels que la longueur totale du coulisseau à laquelle est additionné le débattement total de ce coulisseau, sous l'effet de la rotation de l'excentrique, permet à l'axe géométrique X1X1 de ce coulisseau de se situer à gauche de l'axe du cylindre, en considérant les figures, et cela tant au point mort haut qu'au point mort bas du piston. Préférentiellement, le débattement angulaire de cet excentrique est de l'ordre de 120° entre ses deux positions extrêmes. Pour exécuter le calage initial du secteur denté lors du montage du dispositif, le point milieu M1 du secteur denté de l'excentrique est situé à mi- distance au point M2 de la longueur de la crémaillère d'une façon telle que l'axe X1X1 de cet excentrique soit à la même hauteur que l'axe X2X2 du maneton au point mort haut et au point mort bas du piston. Ainsi à partir de cette position nominale, l'excentrique tourne dans le sens anti-horaire d'un angle d'environ de 60° pour obtenir un taux minimum de compression qui peut être le taux nominal et arrivé à la position de la figure 3 et, pour un taux maximum, tourne, toujours à partir de cette position de calage initial, d'un angle d'approximativement 60° dans le sens horaire pour arriver à la position de la figure 1. Lorsque le taux maximum est atteint, l'excentrique tourne dans le sens anti-horaire d'un angle d'environ 120° pour atteindre le taux minimum et d'environ 120° dans le sens horaire pour obtenir un taux maximum à partir de son taux minimum. Les volumes délimités par la paroi périphérique du logement, ses parois extrêmes et les faces terminales du coulisseau forment ainsi deux chambres fluidiques étanches, respectivement 75a et 75b, qui permettent d'autoriser et de contrôler le déplacement du coulisseau dans le logement. Il est ainsi formé un vérin fluidique 76 comprenant le support 58 avec son logement 56 dans lequel se déplace le coulisseau 54, de manière rectiligne, sous l'effet du fluide présent dans les chambres 75a, 75b. Ainsi, le dispositif de variation comprend un coulisseau et un support de coulisseau distincts de l'excentrique. La position relative en translation de ce coulisseau, par rapport à son support, est continûment liée cinématiquement au débattement angulaire de l'excentrique par rapport à la bielle par une liaison cinématiquement réversible.This rack has an extension in length which corresponds at least to the developed of the toothed sector 48 of the eccentric 42. The housing 56 is of shape complementary to the cross section of that of the slide 54 and comprises two end walls 74. The distance between these two walls and the setting of the toothed sector of the eccentric relative to the toothed bearing of the slide are such that the total length of the slide to which is added the total travel of this slide, under the effect of the rotation of the eccentric , allows the geometric axis X1X1 of this slide to be located to the left of the cylinder axis, considering the figures, and this both at top dead center and bottom dead center of the piston. Preferably, the angular movement of this eccentric is of the order of 120 ° between its two extreme positions. To carry out the initial setting of the toothed sector during the mounting of the device, the midpoint M1 of the toothed sector of the eccentric is located mid-distance from point M2 of the length of the rack in such a way that the axis X1X1 of this eccentric is at the same height as the axis X2X2 of the crank pin at top dead center and bottom dead center of the piston. So from this position nominal, the eccentric turns anti-clockwise by an angle of approximately 60 ° to obtain a minimum compression rate which can be the nominal rate and arrived at the position of figure 3 and, for a maximum rate , rotates, always from this initial setting position, by an angle of approximately 60 ° clockwise to arrive at the position of figure 1. When the maximum rate is reached, the eccentric turns in the direction anti-clockwise by an angle of approximately 120 ° to reach the minimum rate and approximately 120 ° clockwise to obtain a maximum rate from its minimum rate. The volumes delimited by the peripheral wall of the housing, its end walls and the end faces of the slider thus form two sealed fluid chambers, respectively 75a and 75b, which make it possible to authorize and control the movement of the slider in the housing. There is thus formed a fluid cylinder 76 comprising the support 58 with its housing 56 in which the slide 54 moves, in a rectilinear manner, under the effect of the fluid present in the chambers 75a, 75b. Thus, the variation device comprises a slide and a slide support separate from the eccentric. The relative position in translation of this slide, with respect to its support, is continuously kinematically linked to the angular movement of the eccentric relative to the rod by a kinematically reversible link.
Ce logement est connecté à un circuit de commande 77, comme montré sur la figure 4, qui permet de contrôler la rotation de l'excentrique grâce à la maîtrise du déplacement du coulisseau. Ce circuit de commande comprend au moins un circuit fermé dans lequel circule un fluide, par exemple de l'huile. Dans l'exemple de la figure 4, le circuit de commande comprend deux circuits fermés 78a et 78b pour lesquels chaque circuit fermé relie les deux chambres 75a et 75b. La chambre 75a est connectée par une canalisation 80a à un moyen de vannage 82a et plus particulièrement à une vanne 3 voies dont l'une des voies est raccordée à la canalisation 80a et dont l'autre des voies est reliée à une bâche 84a par une canalisation 86a. Cette vanne est commandée par un moyen 88a dont l'actionnement est tributaire de la demande de variation du taux de compression. Une canalisation 90a relie ensuite la sortie de la vanne 82a à un dispositif doseur 92a comprenant un cylindre 94a avec un piston étanche 96a mobile à l'intérieur de ce cylindre et qui délimitent deux chambres de dosage 98a et 100a. La chambre 98a est reliée à la canalisation 90a alors que la chambre 100a, qui comprend un ressort 102a, est reliée par une canalisation 104a à la chambre fluidique 75b. Avantageusement, les canalisations 80a et 104a portent des clapets anti-retour 106a et 108a évitant respectivement un retour de fluide dans la chambre 75a et une sortie de fluide de la chambre 75b. Additionnellement, ce circuit de commande comprend des moyens de remplissage et de purge des circuits 78a et 78b. Ces moyens comprennent une pompe hydraulique 110, des canalisations 112a, 112b portant chacune un clapet anti-retour et connectées aux canalisations 104a, 104b, des vannes de purge 114a et 114 reliées aux canalisations 80a et 80b et des dispositifs de purge 116a et 116b situés sur les dispositifs doseurs 92a et 92b. Ainsi, en considérant la figure 4, le déplacement du coulisseau 54 vers la gauche est contrôlé par la commande en ouverture de la vanne 82a qui met en communication, par les canalisations 80a et 90a, la chambre fluidique 75a avec la chambre de dosage 98a. Sous l'effet de la pression générée dans la chambre fluidique 75a par le déplacement du coulisseau sous l'impulsion de l'excentrique, le piston 96a est poussé à encontre du ressort 102a en direction de la chambre de dosage 100a et le fluide présent dans cette chambre est introduit par la canalisation 104a dans la chambre fluidique 75b. Ainsi, toute diminution du volume d'une chambre fluidique se traduit par une augmentation du volume de l'autre chambre. Ce ressort est taré d'une manière telle qu'il permette de doser l'introduction progressive du fluide dans la chambre 98a, ce qui permet d'éviter les à-coups au niveau du coulisseau. Dès que ce coulisseau a atteint la position souhaitée, la vanne 82a est actionnée en fermeture par la commande 88a pour maintenir le coulisseau dans la position où il est arrivé. Lors de cette action, d'une part, la communication entre les chambres 75a et 98a est fermée et, d'autre part, l'évacuation du fluide présent dans la chambre de dosage 98a, sous l'impulsion du ressort 102a, est autorisée par les canalisations 90a et 86a vers la bâche 84a. Le volume de la chambre de dosage 98a est conformé d'une façon telle qu'il corresponde à une valeur de déplacement déterminé du coulisseau, dénommée dans la suite de la description incrément, cet incrément pouvant être utilisé en partie ou en totalité lors du déplacement de ce coulisseau. Pour ajuster le taux de compression à la valeur souhaitée, le volume de fluide issu de la chambre fluidique 75a, lors du déplacement du coulisseau, peut être supérieur à cet incrément. Dans ce cas, la commande 88a commande plusieurs séquences d'ouverture et de fermeture de la vanne 82a pour, séquentiellement, remplir et vider la chambre 98a en maintenant le coulisseau dans la position atteinte puis commande en fermeture cette vanne dès que l'excentrique a atteint la position souhaitée. Le déplacement du coulisseau 54 dans le sens opposé, c'est-à-dire vers la droite, est contrôlé de la même manière mais en agissant sur les différents éléments du circuit fermé 78b. Ainsi, pour pouvoir imposer le sens de débattement de l'excentrique dans le sens horaire ou dans le sens anti-horaire, on agira sur l'un ou l'autre des circuits. En ce qui concerne le remplissage des circuits 78a, 78b et de leur purge, la pompe hydraulique 110 remplit, par l'intermédiaire des canalisations 112a, 112b, les chambres de dosage 100a, 100b et les canalisations 104a, 104b. Par ces canalisations, les chambres fluidiques 75a, 75b sont également remplies, ainsi que les canalisations 80a, 80b grâce auxquelles le remplissage des chambres de dosage 98a, 98b est assuré. Pendant ce remplissage, les vannes de purge 114a, 114b ainsi que les purges 116a, 116b sont ouvertes pour évacuer l'air éventuellement présent dans les circuits. Bien entendu et comme cela est habituel, la pompe et les canalisations 112a, 112b seront utilisées pour compenser les éventuelles pertes de fluide pendant le fonctionnement du dispositif. En pratique et comme mieux visible sur la figure 5, les différentes canalisations, les dispositifs doseurs, les vannes de purge, les purges, et les clapets anti-retour sont logés dans le support 58, le vilebrequin avec son maneton et l'excentrique. Comme ces différents éléments sont placés dans plusieurs plans parallèles transversaux à l'axe du vilebrequin, seul certains de ces éléments ont été montrés pour éviter de compliquer la figure. On peut donc voir que l'alimentation en fluide pour le remplissage des circuits est réalisée par des alésages axiaux et radiaux 120 dans le vilebrequin et le maneton, par une rainure circonférentielle 122, entre l'alésage de l'excentrique 42 et la paroi périphérique du maneton 34, pour la communication avec les alésages 120, et par des alésages radiaux 124 mettant en communication la rainure 122 avec la canalisation 112 (respectivement 112b) prévue dans le support 58. Ce support comporte également les vannes de commande 82a et 82b, les dispositifs doseurs 92a et 92b, les clapets anti-retour 106 et 108 (respectivement 108a), les vannes de purge 114 (respectivement 114a) et les canalisations 80, 90, 104This housing is connected to a control circuit 77, as shown in FIG. 4, which allows the rotation of the eccentric to be controlled by controlling the movement of the slide. This control circuit comprises at least one closed circuit in which a fluid, for example oil, circulates. In the example of FIG. 4, the control circuit comprises two closed circuits 78a and 78b for which each closed circuit connects the two chambers 75a and 75b. The chamber 75a is connected by a pipe 80a to a valve means 82a and more particularly to a 3-way valve, one of the tracks of which is connected to the pipe 80a and the other of the tracks of which is connected to a sheet 84a by a line 86a. This valve is controlled by a means 88a, the actuation of which is dependent on the request for variation of the rate of compression. A pipe 90a then connects the outlet of the valve 82a to a metering device 92a comprising a cylinder 94a with a sealed piston 96a movable inside this cylinder and which delimit two metering chambers 98a and 100a. The chamber 98a is connected to the pipeline 90a while the chamber 100a, which comprises a spring 102a, is connected by a pipeline 104a to the fluid chamber 75b. Advantageously, the pipes 80a and 104a carry non-return valves 106a and 108a respectively preventing a return of fluid in the chamber 75a and a fluid outlet from the chamber 75b. Additionally, this control circuit includes means for filling and purging circuits 78a and 78b. These means include a hydraulic pump 110, pipes 112a, 112b each carrying a non-return valve and connected to pipes 104a, 104b, purge valves 114a and 114 connected to pipes 80a and 80b and purge devices 116a and 116b located on metering devices 92a and 92b. Thus, considering FIG. 4, the movement of the slide 54 to the left is controlled by the command to open the valve 82a which puts the fluid chamber 75a into communication with the metering chamber 98a via the pipes 80a and 90a. Under the effect of the pressure generated in the fluid chamber 75a by the displacement of the slide under the impulse of the eccentric, the piston 96a is pushed against the spring 102a in the direction of the metering chamber 100a and the fluid present in this chamber is introduced via line 104a into the fluid chamber 75b. Thus, any reduction in the volume of one fluid chamber results in an increase in the volume of the other chamber. This spring is calibrated in such a way that it allows the progressive introduction of the fluid into the chamber 98a to be measured, which makes it possible to avoid jolts at the level of the slide. As soon as this slide has reached the desired position, the valve 82a is actuated in closing by the control 88a to maintain the slide in the position where it has arrived. During this action, on the one hand, the communication between the chambers 75a and 98a is closed and, on the other hand, the evacuation of the fluid present in the metering chamber 98a, under the impulse of the spring 102a, is authorized by pipes 90a and 86a to the cover 84a. The volume of the metering chamber 98a is shaped in such a way that it corresponds to a determined value of displacement of the slide, called in the following description increment, this increment being able to be used in part or in total during displacement of this slide. To adjust the compression ratio to the desired value, the volume of fluid coming from the fluid chamber 75a, during the displacement of the slide, can be greater than this increment. In this case, the command 88a commands several sequences of opening and closing of the valve 82a in order, sequentially, to fill and empty the chamber 98a while maintaining the slide in the position reached then commands to close this valve as soon as the eccentric has reaches the desired position. The movement of the slide 54 in the opposite direction, that is to say to the right, is controlled in the same way but by acting on the various elements of the closed circuit 78b. Thus, in order to be able to impose the direction of movement of the eccentric clockwise or counterclockwise, one will act on one or the other of the circuits. As regards the filling of the circuits 78a, 78b and their purging, the hydraulic pump 110 fills, via the pipes 112a, 112b, the metering chambers 100a, 100b and the pipes 104a, 104b. Through these pipes, the fluid chambers 75a, 75b are also filled, as well as the pipes 80a, 80b through which the filling of the metering chambers 98a, 98b is ensured. During this filling, the purge valves 114a, 114b as well as the purges 116a, 116b are open to evacuate any air present in the circuits. Of course and as is usual, the pump and the pipes 112a, 112b will be used to compensate for any losses of fluid during the operation of the device. In practice and as best seen in FIG. 5, the various pipes, metering devices, purge valves, purges, and non-return valves are housed in the support 58, the crankshaft with its crank pin and the eccentric. As these different elements are placed in several parallel planes transverse to the axis of the crankshaft, only some of these elements have been shown to avoid complicating the figure. It can therefore be seen that the supply of fluid for filling the circuits is carried out by axial and radial bores 120 in the crankshaft and the crankpin, by a circumferential groove 122, between the bore of the eccentric 42 and the peripheral wall crankpin 34, for communication with the bores 120, and by radial bores 124 bringing the groove 122 into communication with the pipe 112 (respectively 112b) provided in the support 58. This support also includes the control valves 82a and 82b, metering devices 92a and 92b, non-return valves 106 and 108 (respectively 108a), drain valves 114 (respectively 114a) and pipes 80, 90, 104
(respectivement 104a) permettant de mettre en communications ces éléments. En fonctionnement, le dispositif de variation de taux de compression est dans une configuration déterminée, comme montré à la figure 3 qui correspond, à titre d'exemple, à un taux minimum de compression, qui peut être le taux nominal, et le piston 14 est à sa position de point mort bas (PMBv) comme illustré à la figure 2. Dans cette configuration, le PMBi est confondu avec le PMBv et le piston 14 a une course de ce point mort bas vers son point mort haut pour réaliser la phase de compression de l'air ou du mélange carburé présent dans la chambre de combustion, comme montré à la figure 1. Pendant cette course et comme illustré aux figures 1 à 3, le maneton 34 parcourt un chemin semi-circulaire pour aller de son point bas (180°) à son point haut (0°). Pendant ce mouvement, le piston 14, la bielle 16 ainsi que l'excentrique 42 subissent d'abord une accélération maximale au point mort bas qui diminue lors du déplacement du piston et de la bielle puis s'annule. Ce piston et cette bielle subissent ensuite une décélération qui augmente au fur et à mesure du rapprochement du piston 14 vers son point mort haut. Lorsque la force résultante de cette décélération est suffisante pour vaincre la résultante des pressions gazeuses qui s'exercent sur le piston, le poids du piston 14 et de la bielle 16 et les différentes forces de frottement, un entraînement du piston et de la bielle est généré par cette force d'inertie dans un mouvement vers le haut en considérant les figures. Ce mouvement est encore plus facilement réalisé que les forces d'inertie, de frottement et de la résultante des pressions gazeuses sont toutes dirigées vers le haut. Ces forces conjuguées s'appliquent sur l'axe X1X1 et créent un couple qui a tendance à faire tourner l'excentrique autour de l'axe X2X2 dans un sens horaire dans la position du coulisseau illustrée à la figure 3. Ainsi, en fonction des paramètres de fonctionnement du moteur, comme la charge et la vitesse de ce moteur, il est déterminé un taux de compression permettant de répondre à la demande. Ce taux de compression est déterminé par une unité de contrôle, par exemple le calculateur que comporte habituellement le moteur, et ce calculateur détermine un angle de débattement de l'excentrique pour obtenir ce taux. En se rapportant à nouveau à la figure 4 et en cas d'augmentation du taux de compression, des instructions de commande sont envoyées, par le calculateur, à la commande 88a de la vanne 3 voies 82a pour mettre en communication, pendant un nombre de séquence, correspondant à un nombre d'incrément et/ou à une partie d'incrément en déplacement du coulisseau, et une durée déterminée par ce calculateur, la chambre fluidique 75a avec le dispositif doseur 92a de manière à autoriser le déplacement du coulisseau par transfert du fluide d'une chambre fluidique 75a vers l'autre chambre fluidique 75b via ce dispositif doseur. Sous l'effet de la rotation de l'excentrique et de par la coopération du secteur denté 48 de l'excentrique avec la crémaillère 52 du coulisseau, ce coulisseau a un déplacement vers la gauche, pour augmenter le taux de compression. Ainsi en contrôlant, de manière précise et de façon continuelle, la quantité de fluide sortant de la chambre fluidique par l'actionnement en ouverture et en fermeture de la vanne, il est possible de piloter le déplacement du coulisseau pour que l'excentrique se déplace en rotation selon le débattement angulaire déterminé par le calculateur. Au terme du nombre d'actionnement de la vanne 82a et de la durée d'ouverture de cette vanne, celle-ci reste fermée en isolant la chambre 75a de la chambre 75b et le coulisseau est immobilisé dans sa position grâce au fluide isolé dans ces chambres. Dans cette configuration, l'excentrique a parcouru le débattement angulaire déterminé par le calculateur. A la fermeture de la vanne 82a, le fluide présent dans la chambre 98a du dispositif doseur 92a est évacué vers la bâche 84a par les canalisations 90a, 86a et le piston 96a de ce dispositif doseur se retrouve à l'état initial, c'est-à-dire proche de la canalisation 90a. Sous l'effet de ce débattement angulaire dans le sens horaire à partir de la figure 3, le piston 14 réalise une surcourse S par rapport à son PMHi pour se trouver dans la position illustrée à la figure 1. Dans cette position, l'entraxe entre l'axe 24 du piston 14 et l'axe du maneton a augmenté et le piston 14 a allongé sa course initiale tout en dépassant le PMHi et en pénétrant dans le volume mort initial 40. Dans cette position, ce volume mort initial est diminué et un nouveau volume mort 118 est créé dans le cylindre 12. Comme ce nouveau volume mort est plus petit que le volume mort initial, il en ressort que le taux de compression du moteur est augmenté. Cette configuration du dispositif est conservée tant que l'on souhaite garder ce taux modifié. Compte tenu du fait que la rotation de l'excentrique est contrôlée de manière continue grâce à un déplacement piloté du coulisseau par les circuits 78a et 78b, il est donc possible de faire varier la valeur de la surcourse S du PMHi jusqu'au PMHv, et par conséquent la grandeur du volume mort. Ainsi, grâce au déplacement piloté du coulisseau, déplacement qui est fonction du temps de réponse et du nombre d'ouverture et de fermeture de la vanne 82a, il est possible d'incrementer ce déplacement et d'obtenir une multitude de possibilités de taux de compression par l'intermédiaire d'une multiplicité de positions angulaires de l'excentrique.(respectively 104a) making it possible to put these elements into communication. In operation, the compression rate variation device is in a determined configuration, as shown in FIG. 3 which corresponds, for example, to a minimum compression rate, which can be the nominal rate, and the piston 14 is in its bottom dead center position (PMBv) as illustrated in figure 2. In this configuration, the PMBi is merged with the PMBv and the piston 14 has a stroke from this bottom dead center to its top dead center to carry out the phase for compressing the air or the fuel mixture present in the combustion chamber, as shown in FIG. 1. During this stroke and as illustrated in FIGS. 1 to 3, the crankpin 34 travels a semi-circular path to go from its point low (180 °) at its high point (0 °). During this movement, the piston 14, the connecting rod 16 and the eccentric 42 first undergo maximum acceleration at bottom dead center which decreases during movement of the piston and the connecting rod and then cancels. This piston and this connecting rod then undergo a deceleration which increases progressively as the piston 14 approaches its top dead center. When the force resulting from this deceleration is sufficient to overcome the resultant of the gas pressures exerted on the piston, the weight of the piston 14 and of the connecting rod 16 and the different friction forces, a drive of the piston and of the connecting rod is generated by this force of inertia in an upward movement in considering the figures. This movement is even more easily achieved as the forces of inertia, friction and the resultant of the gas pressures are all directed upwards. These combined forces apply on the axis X1X1 and create a torque which tends to rotate the eccentric around the axis X2X2 in a clockwise direction in the position of the slide illustrated in Figure 3. Thus, depending on the engine operating parameters, such as the load and speed of this engine, a compression ratio is determined to meet demand. This compression rate is determined by a control unit, for example the computer which usually comprises the engine, and this computer determines a deflection angle of the eccentric to obtain this rate. Referring again to FIG. 4 and in the event of an increase in the compression ratio, control instructions are sent, by the computer, to control 88a of the 3-way valve 82a to put in communication, for a number of sequence, corresponding to an increment number and / or to an incremental part in displacement of the slide, and a duration determined by this computer, the fluid chamber 75a with the metering device 92a so as to allow the displacement of the slide by transfer fluid from one fluid chamber 75a to the other fluid chamber 75b via this metering device. Under the effect of the rotation of the eccentric and through the cooperation of the toothed sector 48 of the eccentric with the rack 52 of the slide, this slide has a movement to the left, to increase the compression ratio. Thus by controlling, precisely and continuously, the quantity of fluid leaving the fluid chamber by actuation in opening and closing of the valve, it is possible to control the movement of the slide so that the eccentric moves in rotation according to the angular movement determined by the computer. At the end of the number of actuation of the valve 82a and the duration of opening of this valve, the latter remains closed while isolating the chamber 75a from the chamber 75b and the slide is immobilized in its position thanks to the fluid isolated in these bedrooms. In this configuration, the eccentric has traversed the angular movement determined by the computer. At closing of the valve 82a, the fluid present in the chamber 98a of the metering device 92a is evacuated towards the tank 84a by the pipes 90a, 86a and the piston 96a of this metering device is found in the initial state, that is to say say close to line 90a. Under the effect of this angular movement in a clockwise direction from FIG. 3, the piston 14 performs an overtravel S with respect to its TDCI to be in the position illustrated in FIG. 1. In this position, the center distance between the axis 24 of the piston 14 and the axis of the crank pin increased and the piston 14 lengthened its initial stroke while exceeding the TDCI and entering the initial dead volume 40. In this position, this initial dead volume is decreased and a new dead volume 118 is created in the cylinder 12. As this new dead volume is smaller than the initial dead volume, it appears that the compression ratio of the engine is increased. This configuration of the device is kept as long as one wishes to keep this modified rate. In view of the fact that the rotation of the eccentric is continuously controlled by means of a controlled displacement of the slide by the circuits 78a and 78b, it is therefore possible to vary the value of the overtravel S from PMHi to PMHv, and therefore the magnitude of the dead volume. Thus, thanks to the controlled displacement of the slide, displacement which is a function of the response time and the number of opening and closing of the valve 82a, it is possible to increment this displacement and to obtain a multitude of possibilities of rate of compression through a multiplicity of angular positions of the eccentric.
Dès que le calculateur détermine un nouveau débattement angulaire de l'excentrique qui correspond, pour l'exemple décrit ci-après, à un nouveau taux de compression plus faible que celui atteint, ce nouveau taux pouvant être le taux initial de compression pour lequel l'on retrouve le volume mort initial ou alors un taux inférieur à celui qui a été obtenu dans une phase précédente d'augmentation de ce taux, le calculateur envoie des instructions à la commande 88b de la vanne 82b du circuit 78b pour que l'excentrique 42 soit dans la position illustrée à la figure 3 ou dans une position se rapprochant de cette figure pour diminuer le taux de compression obtenu dans une phase , antérieure. Pour ce faire, on utilise une phase de fonctionnement du moteur durant laquelle le maneton 34 va de sa position de 0° à 180°, comme la phase d'admission ou de détente. Lors de cette phase, les forces telles que décrites précédemment s'appliquent sur le maneton mais dans un sens opposé. Ceci a pour effet d'appliquer une force sur l'axe X1X1 qui a tendance à faire tourner l'excentrique autour de l'axe X2X2 dans un sens anti-horaire. Pour autoriser cette rotation de l'excentrique, il suffit d'autoriser le déplacement contrôlé du coulisseau dans son logement. Pour cela et en se rapportant à la figure 4, la commande en ouverture/fermeture pendant une durée déterminée et en fermeture de la vanne 3 voies 82b permet de mettre en communication la chambre fluidique 75b avec le dispositif doseur 92b de manière à autoriser ce déplacement du coulisseau tout en contrôlant le transfert des doses de fluide dosées par le dispositif doseur 92b d'une chambre fluidique 75b vers l'autre chambre fluidique 75a. Sous l'effet de la rotation de l'excentrique générée par la force d'inertie et de par la coopération du secteur denté 48 de l'excentrique avec la portée dentée 52 du coulisseau, ce coulisseau a un déplacement vers la droite pour arriver à la position illustrée à la figure 3. Egalement, ce déplacement du coulisseau est continuellement contrôlé par action sur la vanne 82b ce qui permet d'obtenir une multiplicité de positions angulaires de l'excentrique durant son déplacement dans le sens anti-horaire et par conséquent une multiplicité de possibilités de diminution de la surcourse du piston, ce qui a pour effet d'obtenir une multiplicité de possibilités d'augmentation du volume mort 118 jusqu'au volume mort initial 40. Ainsi, grâce à ce dispositif de variation du taux de compression, il est non seulement possible d'obtenir une multiplicité de possibilités d'augmentation du taux de compression mais aussi une multiplicité de possibilités de diminution de ce taux à partir d'un taux qui a subi une augmentation.As soon as the computer determines a new angular movement of the eccentric which corresponds, for the example described below, to a new compression rate lower than that reached, this new rate possibly being the initial compression rate for which l '' we find the initial dead volume or a rate lower than that obtained in a previous phase of increase in this rate, the computer sends instructions to the control 88b of the valve 82b of the circuit 78b so that the eccentric 42 either in the position illustrated in Figure 3 or in a position approaching this figure to reduce the compression ratio obtained in an earlier phase. To do this, an engine operating phase is used during which the crankpin 34 goes from its position from 0 ° to 180 °, like the intake or expansion phase. During this phase, the forces as described above apply to the crankpin but in an opposite direction. This has the effect of applying a force on the axis X1X1 which tends to rotate the eccentric around the axis X2X2 in a counterclockwise direction. To authorize this rotation of the eccentric, it is sufficient to authorize the controlled movement of the slide in its housing. For this and referring to FIG. 4, the command to open / close for a determined period and to close the 3-way valve 82b makes it possible to put the fluid chamber 75b in communication with the metering device 92b so as to authorize this movement of the slide while controlling the transfer of the doses of fluid metered by the metering device 92b from one fluid chamber 75b to the other fluid chamber 75a. Under the effect of the rotation of the eccentric generated by the force of inertia and by the cooperation of the toothed sector 48 of the eccentric with the toothed bearing 52 of the slide, this slide has a movement to the right to arrive at the position illustrated in Figure 3. Also, this movement of the slide is continuously controlled by action on the valve 82b which allows to obtain a multiplicity of angular positions of the eccentric during its movement counterclockwise and therefore a multiplicity of possibilities for reducing the piston overtravel, which has the effect of obtaining a multiplicity of possibilities for increasing the dead volume 118 to the initial dead volume 40. Thus, thanks to this device for varying the rate of compression, it is not only possible to obtain a multiplicity of possibilities for increasing the compression rate but also a multiplicity of possibilities of reducing this rate from a rate which has undergone an increase.
On se reporte maintenant à la figure 6a qui montre une variante de réalisation de l'invention. Cette variante ne diffère de la réalisation décrite ci-dessus que par le fait que chaque vanne 3 voies est remplacée par deux dispositifs piézoélectriques 126 (respectivement 126b) qui permettent d'améliorer le temps de réponse et en conséquence d'accroître la précision du réglage du taux de compression. Chacun de ces dispositifs comprend un pointeau 128 soumis à l'action d'un actionneur piézoélectrique 130 et constitue une vanne deux voies. L'un de ces dispositifs piézoélectriques contrôle le passage du fluide entre la canalisation 80 (respectivement 80b) et la canalisation 90 (respectivement 90b) et l'autre des dispositifs piézoélectriques contrôle le passage du fluide entre la canalisation 90 (respectivement 90b) et la canalisation 86. Ainsi, chaque vanne 3 voies 82a, 82b du circuit montré à la figure 4 est remplacée par deux vannes 2 voies formées chacune par un dispositif piézoélectrique. Pour commander l'actionneur piézoélectrique qui agit sur le débattement du pointeau, le support 58 porte deux plots électriques 132 raccordés par des conducteurs électriques (non représentés) à cet actionneur. Des pistes électriques 134 sont portées par un élément fixe du moteur, comme le carter moteur, et sont disposées d'une manière telle qu'elles se trouvent continuellement en regard des plots 132 au moins pour un déplacement du maneton de son point à 0° à son point situé à 180°, comme cela est illustré sur les figures 6a à 6d. Bien entendu et cela sans sortir du cadre de l'invention, ces pistes peuvent s'étendre sur la totalité de la rotation du maneton de 360°. Ces pistes sont parcourues par un courant électrique et induisent un champ magnétique qui crée un courant électrique au niveau des plots 132 pour la commande de l'actionneur. Avantageusement, une piste électrique 134 est affectée à la commande de chacun des dispositifs piézoélectriques et une cinquième piste est commune pour la commande des quatre actionneurs piézoélectriques 130. Le fonctionnement du dispositif de variation du taux de compression 32 et des circuits 78a, 78b est le même que celui décrit en relation avec les figures 1 à 5 aux différences selon lesquelles la liaison du passage de fluide entre la chambre fluidique 75a, 75b et la chambre de dosage 98a, 98b est réalisée par une première vanne 2 voies constituée d'un dispositif piézoélectrique, la liaison du passage de fluide entre la chambre de dosage 98a, 98b et la bâche 84a, 84b est réalisée par une autre vanne 2 voies constituée d'un dispositif piézoélectrique, et un courant électrique est envoyé dans les pistes 134 pour contrôler l'ouverture du pointeau 128 lors de la demande de variation du taux dé compression. Les exemples de réalisation de la commande du dispositif de variation décrits jusqu'à maintenant prévoient l'utilisation de deux circuits fermés pour contrôler le déplacement du coulisseau. Mais il peut être envisagé de n'utiliser qu'un seul circuit comportant une canalisation mettant en communication la chambre 75a avec un moyen de vannage, comme la vanne 3 voies, qui serait alors remplacée par une vanne 2 voies ou le dispositif piézoélectrique décrit précédemment, et une canalisation reliant le moyen de vannage avec l'autre chambre fluidique 75b. Bien entendu, les moyens de remplissage avec leur pompe hydraulique et les canalisations de raccordement avec la canalisation reliant le moyen de vannage à la chambre 75b, ainsi que les vannes de purge peuvent être également prévus sur ce circuit unique.Referring now to Figure 6a which shows an alternative embodiment of the invention. This variant differs from the embodiment described above only in that each 3-way valve is replaced by two piezoelectric devices 126 (respectively 126b) which make it possible to improve the response time and consequently increase the precision of the adjustment. compression ratio. Each of these devices comprises a needle 128 subjected to the action of a piezoelectric actuator 130 and constitutes a two-way valve. One of these piezoelectric devices controls the passage of the fluid between the pipe 80 (respectively 80b) and the pipe 90 and the other of the piezoelectric devices controls the passage of the fluid between the pipe 90 (respectively 90b) and the pipe 86. Thus, each 3-way valve 82a, 82b of the circuit shown in FIG. 4 is replaced by two 2-way valves each formed by a piezoelectric device. To control the piezoelectric actuator which acts on the movement of the needle, the support 58 carries two electrical pads 132 connected by electrical conductors (not shown) to this actuator. Electrical tracks 134 are carried by a fixed element of the engine, such as the motor casing, and are arranged in such a way that they are continuously facing the studs 132 at least for a displacement of the crankpin from its point to 0 ° at its point located at 180 °, as illustrated in Figures 6a to 6d. Of course, without departing from the scope of the invention, these tracks can extend over the entire rotation of the crankpin of 360 °. These tracks are traversed by an electric current and induce a magnetic field which creates an electric current at the level of the studs 132 for the control of the actuator. Advantageously, an electrical track 134 is assigned to the control of each of the piezoelectric devices and a fifth track is common for the control of the four piezoelectric actuators 130. The operation of the device for varying the compression ratio 32 and of the circuits 78a, 78b is the same as that described in relation to FIGS. 1 to 5 except that the connection of the fluid passage between the fluid chamber 75a, 75b and the metering chamber 98a, 98b is produced by a first 2-way valve made up of a piezoelectric device, the connection of the fluid passage between the metering chamber 98a, 98b and the tank 84a, 84b is made by another 2-way valve made up of a piezoelectric device, and an electric current is sent into the tracks 134 to control the opening of the needle 128 during the request for variation of the compression rate. The embodiments of the control of the variation device described so far provide for the use of two closed circuits to control the movement of the slide. However, it can be envisaged to use only a single circuit comprising a pipe connecting the chamber 75a with a valve means, such as the 3-way valve, which would then be replaced by a 2-way valve or the piezoelectric device described above. , and a pipe connecting the valve means with the other fluid chamber 75b. Of course, the filling means with their hydraulic pump and the pipes connecting with the pipe connecting the valve means to the chamber 75b, as well as the purge valves can also be provided on this single circuit.
Pour pouvoir connaître à tous moments le taux de compression du moteur, il est prévu un moyen de localisation de la situation angulaire de l'excentrique 42, comme cela est illustré sur les figures 7a à 7d. Ce moyen comprend un ensemble émetteur-récepteur de signaux 136, dont l'un des éléments est porté par l'excentrique 42 et dont l'autre des éléments est porté par un élément fixe du moteur, comme une patte 138 issue d'une paroi de ce carter. Avantageusement, l'excentrique porte un index 140 qui émet un signal par rayonnement, par exemple par rayonnement magnétique, et la patte 138 porte un récepteur formé par un secteur de lecture 142 du signal émis par l'index 140 et qui permet de connaître la position de cet index durant la rotation du maneton 34. Ce secteur de lecture est sensiblement en arc de cercle, dont la concavité est dirigée vers le vilebrequin, avec une épaisseur radiale E sensiblement constante. Ce secteur comporte une première région de lecture 144 située dans sa partie haute pour la lecture du signal émis par l'index 140 lorsque le taux de compression est maximal ou est augmenté et une deuxième région 146 placée dans la partie basse de ce secteur pour la lecture du signal émis par l'index 140 lorsque le taux de compression est nominal ou est diminué. Pendant le fonctionnement du moteur, le calculateur que comporte habituellement ce moteur détermine le calage angulaire C de l'excentrique par rapport à l'axe longitudinal de la bielle (figure 7a) pour obtenir un taux de compression défini et cela lorsque le piston est au point mort haut. Pour arriver à vérifier l'exactitude du calage mesuré par rapport au calage déterminé par le calculateur, ce dernier prend en compte l'intensité du signal reçu par la région de lecture 144. Dans le cas de la figure 7a, ce signal est au plus haut lorsque le point d'émission 148 de l'index 140 se situe sensiblement au milieu de l'épaisseur E de cette région de lecture et correspond à un taux de compression maximal. Ainsi, on peut commander les différentes valeurs du taux de compression en tenant compte de la position du point d'émission 148 de l'index 140 par rapport au milieu de l'épaisseur E de cette région de lecture. De ce fait, l'un des circuits fermés 78a, 78b sera opérationnel de façon à ce que le coulisseau 54 se déplace pour autoriser un débattement angulaire de l'excentrique 42 permettant d'obtenir un tel positionnement du point d'émission 148. Dès que ce calage angulaire est obtenu, le piston quitte son point mort haut pour aller vers son point mort bas (figures 7b et 7c) et l'index 140 s'éloigne de la zone centrale de la région 144 (figure 7b) pour finalement arriver, au voisinage du point mort bas, à distance du secteur 142 (figure 7c). De même, ce calculateur détermine le calage angulaire Ci (figure 7d) de l'excentrique par rapport à l'axe longitudinal de la bielle, lorsque le piston est au point mort bas, pour obtenir un taux de compression nominal ou pour diminuer le taux de compression obtenu lors d'une phase précédente. Pour arriver à cette détermination, ce calculateur prend en compte l'intensité du signal reçu par la région de lecture 146 et, comme précédemment mentionné, ce signal est au plus haut lorsque le point d'émission de l'index 140 se situe sensiblement au milieu de l'épaisseur E de cette région. De ce fait, les circuits 78a, 78b seront actionnés d'une manière telle que coulisseau puisse autoriser un débattement angulaire de l'excentrique permettant d'obtenir un tel calage angulaire.In order to be able to know at all times the compression ratio of the engine, a means is provided for locating the angular position of the eccentric 42, as illustrated in FIGS. 7a to 7d. This means comprises a signal transmitter-receiver assembly 136, one of the elements of which is carried by the eccentric 42 and the other of the elements of which is carried by a fixed element of the motor, such as a lug 138 originating from a wall. of this housing. Advantageously, the eccentric carries an index 140 which emits a signal by radiation, for example by magnetic radiation, and the tab 138 carries a receiver formed by a reading sector 142 of the signal emitted by the index 140 and which makes it possible to know the position of this index during the rotation of the crankpin 34. This reading sector is substantially in an arc, the concavity of which is directed towards the crankshaft, with a substantially constant radial thickness E. This sector comprises a first reading region 144 located in its upper part for reading the signal emitted by the index 140 when the compression ratio is maximum or is increased and a second region 146 placed in the lower part of this sector for reading of the signal emitted by the index 140 when the compression ratio is nominal or is reduced. While the engine is running, the computer that this engine usually includes determines the angular setting C of the eccentric relative to the longitudinal axis of the connecting rod (Figure 7a) to obtain a defined compression ratio when the piston is at top dead center. To arrive at verifying the accuracy of the calibration measured with respect to the calibration determined by the computer, the latter takes into account the intensity of the signal received by the reading region 144. In the case of FIG. 7a, this signal is at most high when the emission point 148 of the index 140 is situated substantially in the middle of the thickness E of this reading region and corresponds to a maximum compression ratio. Thus, the different values of the compression ratio can be controlled by taking into account the position of the emission point 148 of the index 140 relative to the middle of the thickness E of this reading region. Therefore, one of the closed circuits 78a, 78b will be operational so that the slider 54 moves to allow an angular movement of the eccentric 42 allowing such a positioning of the emission point 148 to be obtained. that this angular setting is obtained, the piston leaves its top dead center to go to its bottom dead center (Figures 7b and 7c) and the index 140 moves away from the central area of the region 144 (Figure 7b) to finally arrive , in the vicinity of bottom dead center, away from sector 142 (Figure 7c). Likewise, this computer determines the angular setting Ci (FIG. 7d) of the eccentric relative to the longitudinal axis of the connecting rod, when the piston is in bottom dead center, in order to obtain a nominal compression ratio or to decrease the ratio compression obtained in a previous phase. To arrive at this determination, this computer takes into account the strength of the signal received by the reading region 146 and, as previously mentioned, this signal is at its highest when the point of emission of the index 140 is located substantially in the middle of the thickness E of this region. As a result, the circuits 78a, 78b will be actuated in such a way that the slider can allow an angular movement of the eccentric making it possible to obtain such an angular setting.
Selon une variante, ce secteur de lecture 142 comporte des fils conducteurs isolés entre eux et disposés sensiblement radialement par rapport à sa forme en arc de cercle sur son épaisseur E. Ces fils conducteurs constituent une pluralité de récepteurs des signaux émis par l'index 140, réparti angulairement depuis la partie supérieure du secteur de lecture 142 jusqu'à sa partie inférieure. L'index 140 décrit à chaque rotation du vilebrequin une courbe sensiblement circulaire de rayon inférieur au rayon de la forme sensiblement circulaire du secteur de lecture 142. La courbe sensiblement circulaire décrite par l'index 140 se translate en fonction du calage angulaire de l'excentrique 42. Cette translation, le rayon du secteur de lecture 142 et sa position sont tels que l'index 140 vient en regard des fils conducteurs de l'épaisseur E du secteur de lecture 142 selon un arc de cercle dont la position est caractéristique du calage angulaire de l'excentrique 42. De ce fait, la connaissance de l'identité des fils conducteurs sur l'épaisseur E du secteur de lecture informé par l'index 140 au cours de la rotation du vilebrequin permet de connaître la position angulaire de l'excentrique avec une précision fonction du pas des fils conducteur. Selon une autre variante, la précision de lecture du calage angulaire de l'excentrique 42 est améliorée par la lecture conjuguée de la position et de l'intensité des signaux perçus par les fils conducteurs informés par l'index 140 au cours de la rotation du vilebrequin. Lorsque l'index 140 est totalement en regard de l'épaisseur E du secteur de lecture 142, par exemple sur les figures 7a et 7d, au moins l'un des fils conducteur reçoit un signal d'information maximal de l'index 140. Lorsque l'index 140 est partiellement en regard de l'épaisseur E du secteur de lecture 142, par exemple pour la figure 7b, les fils informés reçoivent un signal plus faible de l'index 140.According to a variant, this reading sector 142 comprises conductive wires isolated from each other and arranged substantially radially with respect to its shape in an arc of a circle over its thickness E. These conductive wires constitute a plurality of receivers of the signals emitted by the index 140 , angularly distributed from the upper part of the reading sector 142 to its lower part. The index 140 describes at each rotation of the crankshaft a substantially circular curve of radius smaller than the radius of the substantially circular shape of the reading sector 142. The substantially circular curve described by the index 140 translates as a function of the angular setting of the eccentric 42. This translation, the radius of the reading sector 142 and its position are such that the index 140 comes opposite the conductive wires of the thickness E of the reading sector 142 according to an arc of a circle whose position is characteristic of the angular setting of the eccentric 42. As a result, knowing the identity of the conducting wires on the thickness E of the reading sector informed by the index 140 during the rotation of the crankshaft makes it possible to know the angular position of the eccentric with a precision which depends on the pitch of the conducting wires. According to another variant, the reading accuracy of the angular setting of the eccentric 42 is improved by the combined reading of the position and the intensity of the signals perceived by the conducting wires informed by the index 140 during the rotation of the crankshaft. When the index 140 is completely opposite the thickness E of the reading sector 142, for example in FIGS. 7a and 7d, at least one of the conducting wires receives a maximum information signal from the index 140. When index 140 is partially opposite the thickness E of the reading sector 142, for example for FIG. 7b, the informed wires receive a weaker signal from the index 140.
Avantageusement, il sera prévu de diminuer progressivement et de manière continue le taux de compression en augmentant le calage angulaire de C vers Ci et inversement de l'augmenter de Ci vers C et cela, cycle de combustion du moteur par cycle de combustion du moteur.Advantageously, provision will be made to gradually and continuously decrease the compression ratio by increasing the angular setting from C to Ci and vice versa to increase it from Ci to C, and this, engine combustion cycle by engine combustion cycle.
Bien entendu, la présente invention n'est pas limitée aux modes de réalisation décrits mais englobe toutes variantes et équivalents. Notamment, il peut être envisagé que le dispositif de variation du taux de compression soit placé au niveau du pied de bielle 26 avec un excentrique porté par l'axe 24 du piston 14. Of course, the present invention is not limited to the embodiments described but encompasses all variants and equivalents. In particular, it can be envisaged that the device for varying the compression ratio is placed at the level of the connecting rod end 26 with an eccentric carried by the axis 24 of the piston 14.

Claims

REVENDICATIONS
1) Dispositif de variation du taux de compression d'un moteur à combustion interne comprenant au moins un cylindre (10) avec une chambre de combustion (20), un équipage mobile comportant un piston (14) deplaçable en translation sous l'action d'une bielle (16) liée par un axe (24) audit piston et raccordée à un maneton (34) d'un vilebrequin (36), ledit piston effectuant une course entre un point mort haut et un point mort bas en laissant subsister un volume mort (40, 118) au point mort haut dudit piston, le dispositif comprenant un excentrique tracté (42) rotatif permettant de faire varier le taux de compression et des moyens de contrôle (32 ; 78a, 78b) du déplacement de l'excentrique, caractérisé en ce que les moyens de contrôle comprennent un vérin fluidique (76) comportant un coulisseau (54) placé dans un logement (56) formé dans un support (58) et délimitant deux chambres fluidiques (75a, 75b) en communication avec au moins un circuit fermé (77 ; 78a, 78b).1) Device for varying the compression ratio of an internal combustion engine comprising at least one cylinder (10) with a combustion chamber (20), a movable assembly comprising a piston (14) displaceable in translation under the action of '' a connecting rod (16) linked by an axis (24) to said piston and connected to a crankpin (34) of a crankshaft (36), said piston making a stroke between a top dead center and a bottom dead center leaving a dead volume (40, 118) at the top dead center of said piston, the device comprising a rotary eccentric (42) for varying the compression ratio and means of control (32; 78a, 78b) of the displacement of the eccentric , characterized in that the control means comprise a fluid cylinder (76) comprising a slide (54) placed in a housing (56) formed in a support (58) and delimiting two fluid chambers (75a, 75b) in communication with the minus a closed circuit (77; 78a, 78b).
2) Dispositif de variation du taux de compression selon la revendication 1 , caractérisé en ce que les chambres fluidiques (75a, 75b) sont en communication l'une avec l'autre par au moins un circuit fermé (77 ; 78a, 78b).2) Device for varying the compression ratio according to claim 1, characterized in that the fluid chambers (75a, 75b) are in communication with each other by at least one closed circuit (77; 78a, 78b).
3) Dispositif de variation du taux de compression, selon l'une des revendications 1 ou 2, caractérisé en ce que le circuit fermé comprend au moins un moyen de vannage (82a, 82b ; 126) permettant de contrôler le débit de fluide d'une chambre vers l'autre.3) Device for varying the compression ratio, according to one of claims 1 or 2, characterized in that the closed circuit comprises at least one valve means (82a, 82b; 126) for controlling the flow of fluid one room towards the other.
4) Dispositif de variation du taux de compression selon la revendication 3, caractérisé en ce que le moyen de vannage est une vanne à au moins 2 voies (82a, 82b). 5) Dispositif de variation du taux de compression selon la revendication 3, caractérisé en ce que le moyen de vannage est un dispositif piézoélectrique (126). 6) Dispositif de variation du taux de compression selon la revendication 5, caractérisé en ce que le dispositif piézoélectrique comprend un pointeau (128) et un actionneur piézoélectrique (130).4) Device for varying the compression ratio according to claim 3, characterized in that the valve means is a valve with at least 2 channels (82a, 82b). 5) Device for varying the compression ratio according to claim 3, characterized in that the valve means is a piezoelectric device (126). 6) Device for varying the compression ratio according to claim 5, characterized in that the piezoelectric device comprises a needle (128) and a piezoelectric actuator (130).
7) Dispositif de variation du taux de compression selon la revendication 5 ou 6, caractérisé en ce que le dispositif piézoélectrique est commandé par coopération de plots (132) et de pistes électriques (134). 8) Dispositif de variation du taux de compression selon la revendication 3 précédentes, caractérisé en ce que le circuit comprend au moins un dispositif doseur (92a, 92b) situé en aval du moyen de vannage.7) Device for varying the compression ratio according to claim 5 or 6, characterized in that the piezoelectric device is controlled by cooperation of studs (132) and electrical tracks (134). 8) Device for varying the compression ratio according to claim 3 above, characterized in that the circuit comprises at least one metering device (92a, 92b) located downstream of the valve means.
9) Dispositif de variation du taux de compression selon la revendication 8, caractérisé en ce que le dispositif doseur comprend un ensemble piston- cylindre (94a ; 96a) avec un ressort de tarage (102a).9) Device for varying the compression ratio according to claim 8, characterized in that the metering device comprises a piston-cylinder assembly (94a; 96a) with a calibration spring (102a).
10) Dispositif de variation du taux de compression selon la revendication10) Device for varying the compression ratio according to claim
I , caractérisé en ce que les éléments du circuit fermé sont au moins en partie logés dans le vérin (76).I, characterized in that the elements of the closed circuit are at least partly housed in the jack (76).
11) Dispositif de variation du taux de compression selon l'une des revendications précédentes, caractérisé en ce que le dispositif de variation comprend des moyens de localisation (136) de la position de l'excentrique (42).11) Device for varying the compression ratio according to one of the preceding claims, characterized in that the variation device comprises means for locating (136) the position of the eccentric (42).
12) Dispositif de variation du taux de compression selon la revendication12) Device for varying the compression ratio according to claim
I I , caractérisé en ce que les moyens de localisation comprennent un ensemble émetteur-récepteur (136) de signaux. 13) Dispositif de variation du taux de compression selon la revendicationI I, characterized in that the location means comprise a transmitter-receiver assembly (136) of signals. 13) Device for varying the compression ratio according to claim
12, caractérisé en ce que l'excentrique (42) comprend l'émetteur (140, 148) et en ce que le récepteur (142) est logé sur une partie fixe (138) du moteur. 14) Dispositif de variation du taux de compression selon l'une des revendications précédentes, caractérisé en ce que l'excentrique comprend des moyens à coopération de forme (48, 52) avec le coulisseau.12, characterized in that the eccentric (42) comprises the transmitter (140, 148) and in that the receiver (142) is housed on a fixed part (138) of the motor. 14) Device for varying the compression ratio according to one of the preceding claims, characterized in that the eccentric comprises means for form cooperation (48, 52) with the slide.
15) Dispositif de variation du taux de compression selon la revendication 14, caractérisé en ce que les moyens de coopération comprennent un secteur denté (48) porté par l'excentrique (42) et une portée dentée (52) portée par le coulisseau (54).15) Device for varying the compression ratio according to claim 14, characterized in that the cooperation means comprise a toothed sector (48) carried by the eccentric (42) and a toothed bearing (52) carried by the slide (54 ).
16) Procédé de variation du taux de compression d'un moteur à combustion interne, ledit moteur comprenant au moins un cylindre (10) avec une chambre de combustion (20), un équipage mobile comportant un piston (14) mobile en translation sous l'action d'une bielle (16) liée par un axe (24) audit piston et raccordée à un maneton (34) d'un vilebrequin (36), ledit piston effectuant une course entre un point mort haut et un point mort bas en laissant subsister un volume mort (40, 118) au point mort haut dudit piston, caractérisé en ce que le procédé consiste à : - déterminer le taux de compression souhaité du moteur, - déterminer l'étendue du déplacement d'un excentrique tracté rotatif (42) pour obtenir le taux de compression souhaité, - contrôler la rotation de l'excentrique (42) pour obtenir le déplacement déterminé en pilotant un vérin (76) permettant de contrôler le déplacement de l'excentrique (42). 16) Method for varying the compression ratio of an internal combustion engine, said engine comprising at least one cylinder (10) with a combustion chamber (20), a movable assembly comprising a piston (14) movable in translation under the action of a connecting rod (16) linked by an axis (24) to said piston and connected to a crankpin (34) of a crankshaft (36), said piston making a stroke between a top dead center and a bottom dead center in leaving a dead volume (40, 118) at the top dead center of said piston, characterized in that the method consists in: - determining the desired compression ratio of the engine, - determining the extent of displacement of a rotary towed eccentric ( 42) to obtain the desired compression ratio, - controlling the rotation of the eccentric (42) to obtain the determined displacement by driving a jack (76) making it possible to control the displacement of the eccentric (42).
EP04816459A 2003-12-23 2004-12-21 Device for varying a compression ratio of an internal combustion engine and method for using said device Not-in-force EP1756405B1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
FR0315214A FR2864154B1 (en) 2003-12-23 2003-12-23 DEVICE FOR VARIATION OF THE COMPRESSION RATE OF AN INTERNAL COMBUSTION ENGINE AND METHOD FOR USING SUCH A DEVICE
PCT/FR2004/003329 WO2005071242A1 (en) 2003-12-23 2004-12-21 Device for varying a compression ratio of an internal combustion engine and method for using said device

Publications (2)

Publication Number Publication Date
EP1756405A1 true EP1756405A1 (en) 2007-02-28
EP1756405B1 EP1756405B1 (en) 2010-10-27

Family

ID=34630484

Family Applications (1)

Application Number Title Priority Date Filing Date
EP04816459A Not-in-force EP1756405B1 (en) 2003-12-23 2004-12-21 Device for varying a compression ratio of an internal combustion engine and method for using said device

Country Status (6)

Country Link
US (1) US7789050B2 (en)
EP (1) EP1756405B1 (en)
AT (1) ATE486203T1 (en)
DE (1) DE602004029823D1 (en)
FR (1) FR2864154B1 (en)
WO (1) WO2005071242A1 (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN107763061A (en) * 2016-08-19 2018-03-06 上海汽车集团股份有限公司 Automobile, engine, toggle and its link assembly

Families Citing this family (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2882575A1 (en) * 2005-02-28 2006-09-01 Michel Alain Leon Marchisseau Internal combustion engine`s compression ratio adjustment device, has kinematic link without lock and connected to flange ring, and position adjustment mechanism and link integrated in volume, outside crank pin, bearing and lever
DE102012212336A1 (en) * 2012-07-13 2014-01-16 Robert Bosch Gmbh Connecting rod assembly for a cylinder of an internal combustion engine
DE102012020999B4 (en) 2012-07-30 2023-02-23 FEV Europe GmbH Hydraulic freewheel for variable engine parts
DE102012112434B4 (en) 2012-12-17 2022-10-20 Dr. Ing. H.C. F. Porsche Aktiengesellschaft Connecting rod arrangement and method for venting a hydraulic cylinder of such a connecting rod arrangement
CN103244260B (en) * 2013-05-16 2015-09-23 沈大兹 A kind of variable compression ratio and variable expansion compare device
AT515419B1 (en) * 2014-05-12 2015-09-15 Imt C Innovative Motorfahrzeuge Und Technologie Cooperation Gmbh Connecting rod for an internal combustion engine
CN104965998B (en) * 2015-05-29 2017-09-15 华中农业大学 The screening technique of many target agents and/or drug regimen
RU2607436C1 (en) * 2015-11-03 2017-01-10 Александр Алексеевич Семенов Internal combustion engine with variable compression ratio by eccentric mechanism
JP6365570B2 (en) * 2016-02-29 2018-08-01 トヨタ自動車株式会社 Variable length connecting rod and variable compression ratio internal combustion engine
DE102016008306A1 (en) * 2016-07-06 2018-01-11 Avl List Gmbh Connecting rod with adjustable connecting rod length
DE102017107698A1 (en) * 2017-04-10 2018-10-11 Avl List Gmbh Connecting rod with eccentric
CN109386380A (en) * 2017-08-08 2019-02-26 罗灿 Spline exports Ratios internal combustion engine

Family Cites Families (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4864975A (en) 1987-07-03 1989-09-12 Honda Giken Kogyo Kabushiki Kaisha Compression ratio-changing device for internal combustion engines
JP2689296B2 (en) * 1991-12-20 1997-12-10 三菱自動車エンジニアリング株式会社 Variable compression ratio device for internal combustion engine
US5165368A (en) * 1992-03-23 1992-11-24 Ford Motor Company Internal combustion engine with variable compression ratio
DE4226361C2 (en) 1992-08-10 1996-04-04 Alex Zimmer Internal combustion engine
US5595146A (en) * 1994-10-18 1997-01-21 Fev Motorentechnik Gmbh & Co. Kommanditgesellschaft Combustion engine having a variable compression ratio
JP2000130201A (en) * 1998-10-27 2000-05-09 Hideki Yamamoto Compression ratio improving device for internal combustion engine
JP3879385B2 (en) * 2000-10-31 2007-02-14 日産自動車株式会社 Variable compression ratio mechanism of internal combustion engine
US6397796B1 (en) * 2001-03-05 2002-06-04 Ford Global Technologies, Inc. Oiling systems and methods for changing lengths of variable compression ratio connecting rods

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See references of WO2005071242A1 *

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN107763061A (en) * 2016-08-19 2018-03-06 上海汽车集团股份有限公司 Automobile, engine, toggle and its link assembly
CN107763061B (en) * 2016-08-19 2020-03-10 上海汽车集团股份有限公司 Automobile, engine, crank connecting rod mechanism and connecting rod assembly thereof

Also Published As

Publication number Publication date
FR2864154A1 (en) 2005-06-24
US7789050B2 (en) 2010-09-07
WO2005071242A1 (en) 2005-08-04
FR2864154B1 (en) 2007-09-07
US20080022977A1 (en) 2008-01-31
EP1756405B1 (en) 2010-10-27
ATE486203T1 (en) 2010-11-15
DE602004029823D1 (en) 2010-12-09

Similar Documents

Publication Publication Date Title
EP1859135B1 (en) Very compact device for adjusting the compression ratio of an internal combustion engine
EP1756405B1 (en) Device for varying a compression ratio of an internal combustion engine and method for using said device
CA2289568C (en) Device for varying a piston engine effective volumetric displacement and/or volumetric ratio of during its operation
EP2160507B1 (en) Hydroelectric device for closed-loop driving the control jack of a variable compression rate engine
CA2631670C (en) Pressure device for a variable compression ratio engine
EP0407436B1 (en) Motor propulsion, in particular for an automobile vehicle and vehicle comprising such a unit
FR3043720B1 (en) VARIABLE VOLUMETRIC RATIO ENGINE
FR2459369A1 (en) VALVE OPENING ADJUSTMENT DEVICE, FLUID PRESSURE REGULATING VALVE, AND SYSTEM FOR ADJUSTING OPENING OF CAM-CONTROLLED CYLINDER VALVE OF INTERNAL COMBUSTION ENGINE USING THE SAME
FR2663982A1 (en) DEVICE FOR ADJUSTING THE VALVE CONTROL OF AN INTERNAL COMBUSTION ENGINE.
FR3043739A1 (en) ROD FOR MOTOR WITH VARIABLE VOLUMETRIC RATIO
FR2468732A1 (en) VARIABLE DISTRIBUTION WITH HYDRAULIC CONTROL FOR INTERNAL COMBUSTION ENGINES
FR2668538A1 (en) INTAKE VALVE AND EXHAUST VALVE DELIVERY CONTROL SYSTEM FOR INTERNAL COMBUSTION ENGINES.
EP1097321B1 (en) Valve device for hydraulic engine for driving a large flywheel mass
FR2831221A1 (en) Low-pressure hydraulic pump, especially for bicycle hydraulic motor, has several piston pumps in star formation, actuated by multi-lobe cams
EP0498682A1 (en) Deactivating valve operating device for an internal combustion engine
FR2806443A1 (en) Adjusting unit for applying variable control to internal combustion engine valves has a cylindrical worm drive with a screw thread and a sliding element running along the worm drive's thread and sliding on the worm drive
EP3080478A1 (en) Device for regulating the rotation of a shaft, in particular in the automobile field
FR2480853A1 (en) Hydraulic valve control for IC engine - uses piston controlled by concentric sleeves rotated by engine driven satellite gear train
FR2721684A1 (en) Oil metering pump for two-stroke engines.
FR2555661A1 (en) LEVER ARM MECHANISM WITH VARIABLE RATIO
FR2821643A1 (en) COMPRESSED AIR ENGINE EXPANSION CHAMBER
FR2471481A1 (en) Fuel injection pump for IC engine - has rotor and transverse cylinder with pistons operated by cam in rotating ring
FR3117540A1 (en) Camshaft of an internal combustion engine.
FR2614655A1 (en) Control device for actuating a double-action hydraulic jack
FR2663981A1 (en) Device for adjusting the control of the valves of an internal-combustion engine

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

17P Request for examination filed

Effective date: 20070102

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HU IE IS IT LI LT LU MC NL PL PT RO SE SI SK TR

DAX Request for extension of the european patent (deleted)
17Q First examination report despatched

Effective date: 20081001

GRAP Despatch of communication of intention to grant a patent

Free format text: ORIGINAL CODE: EPIDOSNIGR1

GRAS Grant fee paid

Free format text: ORIGINAL CODE: EPIDOSNIGR3

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

AK Designated contracting states

Kind code of ref document: B1

Designated state(s): AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HU IE IS IT LI LT LU MC NL PL PT RO SE SI SK TR

REG Reference to a national code

Ref country code: GB

Ref legal event code: FG4D

Free format text: NOT ENGLISH

REG Reference to a national code

Ref country code: CH

Ref legal event code: EP

REG Reference to a national code

Ref country code: IE

Ref legal event code: FG4D

Free format text: LANGUAGE OF EP DOCUMENT: FRENCH

REF Corresponds to:

Ref document number: 602004029823

Country of ref document: DE

Date of ref document: 20101209

Kind code of ref document: P

REG Reference to a national code

Ref country code: NL

Ref legal event code: VDEP

Effective date: 20101027

LTIE Lt: invalidation of european patent or patent extension

Effective date: 20101027

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: GB

Payment date: 20101224

Year of fee payment: 7

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: LT

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20101027

REG Reference to a national code

Ref country code: IE

Ref legal event code: FD4D

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: FI

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20101027

Ref country code: NL

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20101027

Ref country code: AT

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20101027

Ref country code: SE

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20101027

Ref country code: SI

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20101027

Ref country code: PT

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20110228

Ref country code: BG

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20110127

Ref country code: IS

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20110227

REG Reference to a national code

Ref country code: DE

Ref legal event code: R081

Ref document number: 602004029823

Country of ref document: DE

Owner name: IFP ENERGIES NOUVELLES, FR

Free format text: FORMER OWNER: MICHEL MARCHISSEAU, INSTITUT FRANCAIS DU PETROLE, , FR

Effective date: 20110329

Ref country code: DE

Ref legal event code: R081

Ref document number: 602004029823

Country of ref document: DE

Owner name: MARCHISSEAU, MICHEL, FR

Free format text: FORMER OWNER: MICHEL MARCHISSEAU, INSTITUT FRANCAIS DU PETROLE, , FR

Effective date: 20110329

Ref country code: DE

Ref legal event code: R081

Ref document number: 602004029823

Country of ref document: DE

Owner name: MARCHISSEAU, MICHEL, FR

Free format text: FORMER OWNERS: MARCHISSEAU, MICHEL, LIMOGES, FR; INSTITUT FRANCAIS DU PETROLE, RUEIL-MALMAISON, HAUTS-DE-SEINE, FR

Effective date: 20110329

Ref country code: DE

Ref legal event code: R081

Ref document number: 602004029823

Country of ref document: DE

Owner name: IFP ENERGIES NOUVELLES, FR

Free format text: FORMER OWNERS: MARCHISSEAU, MICHEL, LIMOGES, FR; INSTITUT FRANCAIS DU PETROLE, RUEIL-MALMAISON, HAUTS-DE-SEINE, FR

Effective date: 20110329

BERE Be: lapsed

Owner name: MARCHISSEAU, MICHEL

Effective date: 20101231

Owner name: INSTITUT FRANCAIS DU PETROLE

Effective date: 20101231

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: GR

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20110128

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: ES

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20110207

Ref country code: MC

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20101231

Ref country code: IE

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20101027

Ref country code: EE

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20101027

Ref country code: CZ

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20101027

REG Reference to a national code

Ref country code: CH

Ref legal event code: PL

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: PL

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20101027

Ref country code: DK

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20101027

Ref country code: RO

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20101027

Ref country code: SK

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20101027

PLBE No opposition filed within time limit

Free format text: ORIGINAL CODE: 0009261

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: BE

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20101231

26N No opposition filed

Effective date: 20110728

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: CH

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20101231

Ref country code: LI

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20101231

REG Reference to a national code

Ref country code: DE

Ref legal event code: R097

Ref document number: 602004029823

Country of ref document: DE

Effective date: 20110728

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: IT

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20101027

GBPC Gb: european patent ceased through non-payment of renewal fee

Effective date: 20111221

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: CY

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20101027

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: LU

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20101221

Ref country code: HU

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20110428

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: GB

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20111221

Ref country code: TR

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20101027

REG Reference to a national code

Ref country code: FR

Ref legal event code: PLFP

Year of fee payment: 12

REG Reference to a national code

Ref country code: FR

Ref legal event code: PLFP

Year of fee payment: 13

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: FR

Payment date: 20161212

Year of fee payment: 13

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: DE

Payment date: 20161228

Year of fee payment: 13

REG Reference to a national code

Ref country code: DE

Ref legal event code: R119

Ref document number: 602004029823

Country of ref document: DE

REG Reference to a national code

Ref country code: FR

Ref legal event code: ST

Effective date: 20180831

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: DE

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20180703

Ref country code: FR

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20180102