EP3589828A1 - Device for controlling the compression rate of a variable compression ratio engine, comprising a two-way solenoid valve provided with a secondary circuit for fluid refilling - Google Patents

Device for controlling the compression rate of a variable compression ratio engine, comprising a two-way solenoid valve provided with a secondary circuit for fluid refilling

Info

Publication number
EP3589828A1
EP3589828A1 EP18709712.6A EP18709712A EP3589828A1 EP 3589828 A1 EP3589828 A1 EP 3589828A1 EP 18709712 A EP18709712 A EP 18709712A EP 3589828 A1 EP3589828 A1 EP 3589828A1
Authority
EP
European Patent Office
Prior art keywords
fluid
valve
accumulator
controlling
compression ratio
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.)
Pending
Application number
EP18709712.6A
Other languages
German (de)
French (fr)
Inventor
Sylvain Bigot
Benjamin TEYSSIER
François Besson
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.)
MCE5 Development SA
Original Assignee
MCE5 Development SA
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 MCE5 Development SA filed Critical MCE5 Development SA
Publication of EP3589828A1 publication Critical patent/EP3589828A1/en
Pending legal-status Critical Current

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
    • 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
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B1/00—Installations or systems with accumulators; Supply reservoir or sump assemblies
    • F15B1/02—Installations or systems with accumulators
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02D—CONTROLLING COMBUSTION ENGINES
    • F02D2700/00—Mechanical control of speed or power of a single cylinder piston engine
    • F02D2700/03—Controlling by changing the compression ratio
    • F02D2700/035—Controlling by changing the compression ratio without modifying the volume of the compression space, e.g. by changing the valve timing
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2201/00—Accumulators
    • F15B2201/40—Constructional details of accumulators not otherwise provided for
    • F15B2201/41—Liquid ports
    • F15B2201/411—Liquid ports having valve means

Definitions

  • the invention relates to a device for controlling the compression ratio of a variable volumetric ratio engine, comprising a control cylinder comprising a piston defining two chambers for receiving a fluid under pressure, an accumulator delivering a fluid under pressure to the two chambers via respectively two separate fluidic circuits, each fluidic circuit comprising a solenoid valve assembly.
  • the invention also relates to a variable volumetric ratio engine comprising such a device and a solenoid valve for the implementation of such a device
  • Application WO2016 / 097546 discloses a variable volumetric ratio motor comprising a hydraulic control cylinder controlled by a single-lever solenoid valve for synchronously controlling the opening and closing of the upper and lower chambers of the control cylinder.
  • the solenoid valve 1 comprises two valve assemblies 2A, 2B, each controlling the flow of a fluid, each valve assembly 2A, 2B comprising a valve body comprising a longitudinal axis channel 30A, 30B AA communicating with at least two fluidic conduits 31A, 32A, 31B, 32B and a valve arrangement comprising a piston 4A, 4B movably mounted within the channel 30A, 30B between an opening position of the fluidic conduits 31A, 32A , 31B, 32B to allow the passage of the fluid from one fluid conduit to the other and a closed position of the fluidic conduits 31A, 32A, 31B, 32B relative to each other, said piston 4A, 4B comprising a magnetizable end portion 40A, 40B and an end opposite the magnetizable end portion, forming a valve adapted to abut against a seat of the valve body.
  • the solenoid valve further comprises a single electromagnetic actuator 5 interposed between the two valve assemblies, and able to simultaneously control the displacement of the piston 4A, 4B of each valve assembly in the open position of the conduits. 31A, 32A, 31B, 32B.
  • the fluidic duct 31A is connected to the upper chamber 113 of the control cylinder while the fluid duct 31B is connected to the lower chamber 112 of the control cylinder.
  • the channel 32A is connected to a pressure accumulator 33 for supplying the upper and lower chambers with fluid under pressure, whereas the conduit 32B is closed at the end.
  • the fluidic conduits 32A, 32B are interconnected by a common channel 34.
  • the solenoid valve 1 thus constitutes a solenoid valve to double direction ensuring the opening or closing of the fluid circuit of the two valve assemblies 2A, 2B by simultaneous displacement of the two pistons 4A, 4B under the magnetic field pulse by the actuator 5.
  • the fluid path when the solenoid valve is open is illustrated in Figure 1.
  • FIG. 2 shows the pressure curves over several engine cycles (720 ° crankshaft) when the control device comprises a micro-leakage. It is understood from the operation of the control device that a leak first appears during pressure peaks in the upper chamber due to the high value of the instantaneous pressure reached. Furthermore, the time duration of pressure peaks being very small (1 to 5 xl0 "s 4 according to the system), the discharged fluid volume is very low in case of micro-leakage.
  • the curve shows the effect of such a micro-leak: a small volume of oil is removed from the system at each cycle, which leads to a decrease in the average pressure in the chambers, the intersection of the curves occurs substantially at the level of the substantially horizontal curve and corresponding to the pressure of the fluid of the accumulator at the beginning, and drift gradually to be at half of the initial value at the end of the cycles represented, whereas when there is no leak, the crossing of the curves is maintained during the whole cycles at the fluid pressure curve of the accumulator ( Figure 3).
  • Figure 3 When the operation continues, it comes to a stage where the oil no longer fills the upper and lower chambers.
  • the piston of the control cylinder is then free to move in the "vacuum cushion" created during the alternation of efforts. The function of maintaining the compression ratio is no longer ensured.
  • the invention aims to remedy these problems by providing a compression rate control device for a variable volumetric ratio engine to maintain the compression ratio even in the presence of micro-leaks at the level of the one of the bedrooms.
  • the invention proposes a device for controlling the compression ratio of a variable volumetric ratio engine comprising a control cylinder comprising a piston defining two chambers for receiving a fluid. under pressure, a pressure accumulator delivering the fluid under pressure, a first fluid circuit connecting the upper chamber to the accumulator and comprising a first valve assembly adapted to control the flow of fluid in said first fluid circuit, a second fluid circuit connecting the lower chamber to the accumulator and comprising a second valve assembly adapted to control the flow of a fluid in said second fluid circuit, characterized in that at least one of the fluidic circuits comprises a bypass duct arranged for connect one of the chambers to the accumulator, said bypass duct comprising a non-return valve arranged for block the flow of fluid from the chamber to the accumulator.
  • a branch circuit (or secondary circuit) comprising a non-return valve thus arranged makes it possible to overcome the pressure drop of the chambers below the pressure of the accumulator in the event of the presence of micro-leaks at one of the chambers allowing the re-feeding of the chamber concerned by the pressure drop.
  • the bypass circuit thus makes it possible to guarantee an average pressure in the chambers at least equal to the pressure of the accumulator, thus making it possible to obtain oscillations of the control jack during a cycle in acceptable values (of the order of 3 millimeters).
  • the bypass duct is arranged to produce a circuit parallel to the fluid circuit of the chamber to which the bypass duct is connected. More particularly, the nonreturn valve is connected in parallel with the fluidic circuit.
  • each fluidic circuit comprises a bypass circuit comprising a nonreturn valve.
  • the first valve assembly and the second valve assembly are connected to the accumulator by a common conduit.
  • first and second fluidic circuits and the first and second valve assemblies are arranged with a magnetic actuator to form a solenoid valve for simultaneous opening and closing of the upper and lower chambers to which the solenoid valve is connected.
  • the invention relates to a solenoid valve comprising two valve assemblies intended to respectively control the flow of a fluid delivered under pressure by a pressure accumulator, each valve assembly comprising a valve body comprising a longitudinal channel AA axis communicating with at least two fluidic circuits and a valve arrangement comprising a piston mounted movably within the channel between an open position of the fluidic circuits to allow the passage of fluid from a fluid circuit to the other and a closed position of the fluid circuits with respect to each other, said piston comprising a magnetizable end portion and an end opposite the magnetizable end portion, forming a valve adapted to press against a seat to cause the closed position, and a single electromagnetic actuator able to control the simultaneous movement the piston of each valve assembly in the open position of the fluidic circuits, the actuator interposed between the two sets of valves, comprising an electromagnetic coil having a coil bore housing a fixed magnetizable target extending with respect to the magnetizable end portions of the pistons of each valve assembly, characterized
  • the non-return valve is connected in parallel with the fluid circuit to which it is connected,
  • the non-return valve is mounted in parallel with the part of the fluidic circuit connecting the channel to the accumulator
  • each fluidic circuit comprises a bypass circuit comprising a non-return valve.
  • the solenoid valve is associated with a control cylinder comprising two chambers (a lower chamber and an upper chamber) delimited by a piston:
  • bypass duct is arranged to produce a circuit parallel to the fluid circuit of the chamber to which the bypass duct is connected.
  • the bypass duct is arranged to connect the lower chamber of the control cylinder to the accumulator.
  • the first and second fluid circuits and the first and second valve assemblies are arranged with a magnetic actuator to form a solenoid valve allowing an opening and simultaneous closing of the upper and lower chambers to which the solenoid valve is connected.
  • the invention also relates to a variable volumetric ratio engine comprising a device for controlling the compression ratio as described above.
  • FIG. 1 shows a schematic view of a compression ratio control device of the prior art implemented to control the compression ratio of a variable volumetric ratio engine
  • - Figure 2 shows the pressure curve over several engine cycles (720 ° crankshaft) when the control device of Figure 1 has a micro-leakage;
  • FIG. 3 shows the pressure curves over several engine cycles (720 ° crankshaft) when the piloting device of FIG. 1 does not exhibit micro-leakage;
  • FIG. 4 represents a schematic view of a compression ratio control device according to the invention intended to be implemented to control the compression ratio of a variable volume ratio engine, when the control device of compression ratio is in open position;
  • FIG. 5 represents a schematization of the control device of FIG. 4; - Figures 6 and 7 show the compression ratio control device of Figure 4 in the closed position, the non-return valve being respectively in the closed position and open.
  • FIG. 8 shows the pressure curves on an engine cycle (720 ° crankshaft) when the two-way solenoid valve comprises a secondary fluid recirculation circuit provided with a non-return valve.
  • a compression rate control device which is intended to be used to control the compression ratio of a variable volumetric ratio engine of the type for example of that described. in the application WO2008 / 148948.
  • the compression ratio control device comprises a control cylinder 110 comprising a piston defining two chambers, a so-called upper chamber 113 and a so-called lower chamber 112, intended to be supplied with hydraulic fluid under pressure, in this case oil, from a pressure accumulator 33.
  • a first fluid circuit 31A, 32A connecting the upper chamber to the accumulator and comprising a first valve assembly 4A
  • a second fluid circuit 31B, 32Breaking the room less than the accumulator and comprising a second valve assembly 4B to do this, a first fluid circuit 31A, 32A connecting the upper chamber to the accumulator and comprising a first valve assembly 4A, a second fluid circuit 31B, 32Breaking the room less than the accumulator and comprising a second valve assembly 4B.
  • the two fluidic circuits and the two valve assemblies are arranged with a magnetic actuator 5 to form a solenoid valve 1 of the type described in WO2016 / 097546, allowing the opening and closing simultaneous upper and lower chambers.
  • the solenoid valve 1 will not be described hereinafter in detail. However, it includes all the characteristics of the solenoid valve described in the aforementioned application. In general, however, the solenoid valve 1 comprises two fluid flow control valve assemblies 2A, 2B and a single electromagnetic actuator interposed between the two valve assemblies.
  • Each valve assembly 2A, 2B comprises a valve body comprising a channel 30A, 30B longitudinal axis A A communicating with at least two fluidic conduits 31A, 32A, 31B, 32B.
  • the channels 30A, 30B are opening on the actuator side 5 and closed on the opposite side to the actuator.
  • the fluidic conduits 31A, 32A, 31B, 32B are formed on the side walls of the channels 30, 30B.
  • the fluid conduit 31A of the solenoid valve 1 is connected to the upper chamber 113 of the control cylinder while the fluid conduit 31B is connected to the lower chamber 112 of the control cylinder.
  • the channel 32A is connected to the pressure accumulator 33 while the conduit 32B is closed at the end.
  • the fluidic conduits 32A, 32B are interconnected by a common channel 34.
  • Each valve assembly further comprises a valve arrangement.
  • the valve arrangement comprises a piston 4A, 4B having a tubular body movably mounted within the channel 30A, 30B between an opening position of the fluidic conduits 31A, 32A, 31B, 32B to allow the passage of fluid from the a fluidic conduit to another and a closed position of the fluid conduits 31A, 32A, 31B, 32B relative to each other.
  • each piston 4A, 4B has an end 41A, 41B adapted to bear against a seat 13A, 13B formed at the end of the channel 30A, 30B associated furthest from the actuator 5 (ie at the closed end of the channel), and thus close the fluidic conduits.
  • the end 41A, 41B thus forms a valve.
  • An opening and orifices are provided respectively at the level of the end 41A, 41B and the tubular body of the pistons 4A, 4B to allow the passage of the fluid inside the latter.
  • the fluidic conduits 31A, 31B are arranged to open into the channels 30A, 30B opposite the wall portion of the piston provided with the orifices while the fluidic conduits 32A, 32B are arranged to open into the channels 30A. , 30B near the closed end of the corresponding channel.
  • the electromagnetic actuator 5 comprises a cylindrical electromagnetic coil 6 having a coil bore and a piece constituting a magnetizable target 8, preferably made of ferrous magnetizable alloy, such as an iron / cobalt alloy, an iron / silicon alloy or other fixedly mounted in said bore.
  • a magnetizable target 8 preferably made of ferrous magnetizable alloy, such as an iron / cobalt alloy, an iron / silicon alloy or other fixedly mounted in said bore.
  • the solenoid valve 1 thus constitutes a two-way solenoid valve for opening or closing the fluid circuit of the two valve assemblies 2A, 2B by simultaneous displacement of the two pistons 4A, 4B under the impulse of the magnetic field created in FIG. 6.
  • the path 36 of the fluid is similar to that of a control device without valve as shown in Figure 1.
  • the control of the compression ratio of the engine is effected by means of the control of the passage of the pressurized fluid from one chamber to the other of the control cylinder 110, and vice versa using the solenoid valve 1.
  • the control device further comprises a so-called bypass conduit 50 comprising a check valve (51) for the re-gavage of one of the chambers in case of micro-leaks generating micro-fluid leaks from the one of said chambers.
  • the bypass duct 50 is arranged to connect the fluid duct leading to the lower chamber to the fluid duct leading to the accumulator. It thus constitutes a bypass duct 50 of the second fluid circuit (or lower fluid circuit).
  • the bypass duct 50 is arranged to thereby provide a circuit parallel to the fluid circuit of the chamber to which the bypass duct 50 is connected.
  • Figures 6 and 7 show the solenoid valve in the closed position.
  • the pressure of the lower chamber of the cylinder is greater than the accumulator pressure.
  • the non-return valve 51 arranged in parallel with the flap 41B piloted, remains closed (FIG. 6).
  • the solenoid valve is closed and the upper chamber has a micro-leakage, the first pressure peak in the chamber after the closure has the effect of lowering the pressure of the lower chamber (at the moment of closure, the situation pressure is the same as the situation before closure).
  • the non-return valve 51 in parallel with the controlled valve 41B, opens, allowing then the introduction of a complementary volume of fluid into the lower chamber of the cylinder and thus the increase of the pressure in the control cylinder. In a few cycles, it can be seen a rise in the average pressure in the cylinder. If the cylinder does not leak, except for a micro-leak, and the check valve 51 has a sufficient reactivity, one can achieve a minimum pressure in the lower chamber equal to the supply pressure. This ensures a minimum pressure in the control cylinder despite the presence of a small leak in the upper chamber. Moreover, this tends to improve the stability of the compression ratio control device by increasing the average pressure in the control cylinder.
  • FIG. 8 shows the pressure curves on an engine cycle (720 ° crankshaft) when the two-way solenoid valve comprises a secondary fluid re-gavage circuit provided with a non-return valve 51. It can be seen that while with the presence of the branch circuit 50, the pressure in the chambers is raised.
  • the bypass duct 50 is provided to re-fill the lower chamber 112. This is a preferred embodiment. It is of course obvious that the invention is not limited to this arrangement, and that a compression rate control device may be provided with a bypass circuit 50 provided for re-gassing the upper chamber 113.
  • the bypass duct 50 comprising the non-return valve 51 is arranged to connect the fluid duct leading to the upper chamber to the fluid duct leading to the accumulator. It thus constitutes a bypass duct 50 of the first fluid circuit (or upper fluid circuit).
  • a compression rate control device comprising a combined arrangement of the two bypass circuits 50 previously described so as to allow the re-feeding of the one or the other of the rooms.

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Physics & Mathematics (AREA)
  • Fluid Mechanics (AREA)
  • Output Control And Ontrol Of Special Type Engine (AREA)
  • Compressors, Vaccum Pumps And Other Relevant Systems (AREA)
  • Magnetically Actuated Valves (AREA)

Abstract

The invention relates to a device for controlling the compression rate of a variable compression ratio engine, comprising an actuating cylinder comprising a piston (111) defining two chambers (112, 113) for receiving a pressure fluid, a pressure accumulator (33) supplying the pressure fluid, a first fluid circuit (31A, 32A) connecting the upper chamber (113) to the accumulator and comprising a first valve assembly (2A) for controlling the flow of the fluid in said first fluid circuit, and a second fluid circuit (31B, 32B) connecting the lower chamber (112) to the accumulator (33) and comprising a second valve assembly (2B) for controlling the flow of a fluid in said second fluid circuit, characterised in that at least one of the fluid circuits comprises a bypass conduit (50) arranged so as to connect one of the chambers (112, 113) to the accumulator (33), said bypass conduit comprising a non-return valve (51).

Description

DISPOSITIF POUR PILOTER LE TAUX DE COMPRESSION D'UN MOTEUR A RAPPORT VOLUMETRIQUE VARIABLE COMPRENANT UNE ELECTROVANNE A DOUBLE SENS POURVUE D'UN CIRCUIT SECONDAIRE DE RE-GAVAGE EN  DEVICE FOR DRIVING THE COMPRESSION RATE OF A VARIABLE VOLUMETRIC RATIO ENGINE COMPRISING A DOUBLE SENSING SOLENOID VALVE PROVIDED WITH A SECONDARY RE-GAVING CIRCUIT
FLUIDE DOMAINE TECHNIQUE DE L'INVENTION  FLUID TECHNICAL FIELD OF THE INVENTION
[001] L'invention concerne un dispositif pour piloter le taux de compression d'un moteur à rapport volumétrique variable, comprenant un vérin de commande comprenant un piston délimitant deux chambres destinées à recevoir un fluide sous pression, un accumulateur délivrant un fluide sous pression aux deux chambres via respectivement deux circuits fluidiques distincts, chaque circuits fluidiques comprenant un ensemble d' électrovanne. [001] The invention relates to a device for controlling the compression ratio of a variable volumetric ratio engine, comprising a control cylinder comprising a piston defining two chambers for receiving a fluid under pressure, an accumulator delivering a fluid under pressure to the two chambers via respectively two separate fluidic circuits, each fluidic circuit comprising a solenoid valve assembly.
[002] L'invention concerne également un moteur à rapport volumétrique variable comprenant un tel dispositif ainsi qu'une électrovanne destinée à la mise en œuvre d'un tel dispositif [002] The invention also relates to a variable volumetric ratio engine comprising such a device and a solenoid valve for the implementation of such a device
ETAT DE LA TECHNIQUE [003] On connaît de la demande WO2016/097546 un moteur à rapport volumétrique variable comprenant un vérin de commande hydraulique commandé par une électrovanne monobobine permettant de commander de manière synchrone l'ouverture et la fermeture des chambres supérieure et inférieure du vérin de commande. Pour ce faire, l'électrovanne 1 comprend deux ensembles de vanne 2A, 2B, commandant chacune l'écoulement d'un fluide, chaque ensemble de vanne 2A, 2B comportant un corps de vanne comprenant un canal 30 A, 30B longitudinal d'axe A A communiquant avec au moins deux conduits fluidiques 31 A, 32A, 31B, 32B et un arrangement formant soupape comprenant un piston 4A, 4B monté mobile à l'intérieur du canal 30A, 30B entre une position d'ouverture des conduits fluidiques 31A, 32A, 31B, 32B pour permettre le passage du fluide d'un conduit fluidique à l'autre et une position de fermeture des conduits fluidiques 31 A, 32A, 31B, 32B l'un par rapport à l'autre, ledit piston 4A, 4B comprenant une portion d'extrémité magnétisable 40A, 40B et une extrémité, opposée à la portion d'extrémité magnétisable, formant un clapet apte à s'appuyer contre un siège du corps de vanne. L'électrovanne comporte en outre un actionneur électromagnétique 5 unique interposé entre les deux ensembles de vanne, et apte à commander de manière simultanée le déplacement du piston 4A, 4B de chaque ensemble de vanne dans la position d'ouverture des conduits fluidiques 31 A, 32A, 31B, 32B. Dans la mise en œuvre d'un dispositif de pilotage de taux de compression (figure 1), le conduit fluidique 31 A est relié à la chambre supérieure 113 du vérin de commande tandis que le conduit fluidique 31B est relié à la chambre inférieure 112 du vérin de commande. Le canal 32A est relié quant à lui à un accumulateur de pression 33 destiné à alimenter les chambres supérieure et inférieure en fluide sous pression, tandis que le conduit 32B est fermé en extrémité. Afin d'assurer le passage du fluide de la chambre inférieure 112 à la chambre supérieure 113 du vérin de commande et inversement, les conduits fluidiques 32A, 32B sont reliés entre eux par un canal commun 34. L' électrovanne 1 constitue ainsi une électrovanne à double sens assurant l'ouverture ou la fermeture du circuit fluidique des deux ensembles de vanne 2A, 2B par déplacement simultané des deux pistons 4A, 4B sous l'impulsion du champ magnétique par l'actionneur 5. Le chemin du fluide lorsque électrovanne est ouverte est illustré sur la figure 1. STATE OF THE ART [003] Application WO2016 / 097546 discloses a variable volumetric ratio motor comprising a hydraulic control cylinder controlled by a single-lever solenoid valve for synchronously controlling the opening and closing of the upper and lower chambers of the control cylinder. To do this, the solenoid valve 1 comprises two valve assemblies 2A, 2B, each controlling the flow of a fluid, each valve assembly 2A, 2B comprising a valve body comprising a longitudinal axis channel 30A, 30B AA communicating with at least two fluidic conduits 31A, 32A, 31B, 32B and a valve arrangement comprising a piston 4A, 4B movably mounted within the channel 30A, 30B between an opening position of the fluidic conduits 31A, 32A , 31B, 32B to allow the passage of the fluid from one fluid conduit to the other and a closed position of the fluidic conduits 31A, 32A, 31B, 32B relative to each other, said piston 4A, 4B comprising a magnetizable end portion 40A, 40B and an end opposite the magnetizable end portion, forming a valve adapted to abut against a seat of the valve body. The solenoid valve further comprises a single electromagnetic actuator 5 interposed between the two valve assemblies, and able to simultaneously control the displacement of the piston 4A, 4B of each valve assembly in the open position of the conduits. 31A, 32A, 31B, 32B. In the implementation of a compression rate control device (FIG. 1), the fluidic duct 31A is connected to the upper chamber 113 of the control cylinder while the fluid duct 31B is connected to the lower chamber 112 of the control cylinder. The channel 32A is connected to a pressure accumulator 33 for supplying the upper and lower chambers with fluid under pressure, whereas the conduit 32B is closed at the end. In order to ensure the passage of the fluid from the lower chamber 112 to the upper chamber 113 of the control cylinder and vice versa, the fluidic conduits 32A, 32B are interconnected by a common channel 34. The solenoid valve 1 thus constitutes a solenoid valve to double direction ensuring the opening or closing of the fluid circuit of the two valve assemblies 2A, 2B by simultaneous displacement of the two pistons 4A, 4B under the magnetic field pulse by the actuator 5. The fluid path when the solenoid valve is open is illustrated in Figure 1.
[004] Afin d'assurer le bon fonctionnement du dispositif de pilotage de taux de compression, il est nécessaire que le vérin soit étanche. Or il peut arriver que des micro-fuites apparaissent au niveau du siège du clapet, en particulier au niveau de la chambre supérieure du fait des fortes pressions exercées sur le clapet de la chambre supérieure (lors de pics de combustion, la chambre supérieure, laquelle reprend les efforts de combustion, peut être amenée à des pressions importantes - de l'ordre de 270 bars) ou du fait d'impuretés qui se seraient concentrées au niveau du siège du clapet. Le fonctionnement du dispositif de pilotage de taux de compression, et donc celui du moteur, s'en trouve alors altéré : lorsqu'une l'une des chambres comporte une micro-fuite, il est constaté une baisse de pression moyenne dans chacune des chambres. Lorsque cette pression moyenne chute en dessous d'une certaine valeur, notamment en dessous de 20 bars, l'amplitude des oscillations du vérin de commande au cours d'un cycle augmente, compromettant de fait le fonctionnement du moteur. [005] La figure 2 montre les courbes de pression sur plusieurs cycles moteur (720° vilebrequin) lorsque le dispositif de pilotage comporte une micro-fuite. On comprend du fonctionnement du dispositif de pilotage qu'une fuite apparaît en premier lieu lors des pics de pression en chambre supérieure du fait de la valeur élevée de la pression instantanée atteinte. Par ailleurs, la durée temporelle de pics de pression étant très faible (de 1 à 5 xl0"4s selon le régime), le volume de fluide évacué est très faible en cas de micro-fuite. La courbe montre l'effet d'une telle micro-fuite : un faible volume d'huile est évacué du système à chaque cycle, ce qui conduit à une baisse de la pression moyenne dans les chambres ; le croisement des courbes intervient sensiblement au niveau de la courbe sensiblement horizontale et correspondant à la pression du fluide de l'accumulateur au début, et dérive progressivement pour être à la moitié de la valeur initiale à la fin des cycles représentés, alors que lorsqu'il n'y a pas de fuite, le croisement des courbes est maintenu durant l'ensemble des cycles au niveau de la courbe de pression du fluide de l'accumulateur (figure 3). Lorsque le fonctionnement se poursuit, on arrive à un stade ou l'huile ne remplit plus les chambres supérieure et inférieure. Le piston du vérin de commande est alors libre de se déplacer dans le «coussin de vide » créé au gré de l'alternance des efforts. La fonction de maintien du taux de compression n'est alors plus assurée. [004] In order to ensure the correct operation of the compression ratio control device, it is necessary that the cylinder is sealed. However it may happen that micro-leaks occur at the valve seat, particularly at the upper chamber due to the high pressures exerted on the valve of the upper chamber (during combustion peaks, the upper chamber, which takes up the combustion forces, can be brought to significant pressures - of the order of 270 bar) or because of impurities that would have concentrated at the seat of the valve. The operation of the compression ratio control device, and therefore that of the engine, is then altered: when one of the chambers includes a micro-leak, it is found a mean pressure drop in each of the chambers . When this average pressure drops below a certain value, in particular below 20 bar, the amplitude of the oscillation of the control cylinder during a cycle increases, thus compromising the operation of the engine. [005] Figure 2 shows the pressure curves over several engine cycles (720 ° crankshaft) when the control device comprises a micro-leakage. It is understood from the operation of the control device that a leak first appears during pressure peaks in the upper chamber due to the high value of the instantaneous pressure reached. Furthermore, the time duration of pressure peaks being very small (1 to 5 xl0 "s 4 according to the system), the discharged fluid volume is very low in case of micro-leakage. The curve shows the effect of such a micro-leak: a small volume of oil is removed from the system at each cycle, which leads to a decrease in the average pressure in the chambers, the intersection of the curves occurs substantially at the level of the substantially horizontal curve and corresponding to the pressure of the fluid of the accumulator at the beginning, and drift gradually to be at half of the initial value at the end of the cycles represented, whereas when there is no leak, the crossing of the curves is maintained during the whole cycles at the fluid pressure curve of the accumulator (Figure 3). When the operation continues, it comes to a stage where the oil no longer fills the upper and lower chambers. The piston of the control cylinder is then free to move in the "vacuum cushion" created during the alternation of efforts. The function of maintaining the compression ratio is no longer ensured.
[006] L'invention vise à remédier à ces problèmes en proposant un dispositif de pilotage de taux de compression pour un moteur à rapport volumétrique variable permettant le maintien du taux de compression même en cas de présence de micro-fuites au niveau de l'une des chambres. [006] The invention aims to remedy these problems by providing a compression rate control device for a variable volumetric ratio engine to maintain the compression ratio even in the presence of micro-leaks at the level of the one of the bedrooms.
OBJET DE L'INVENTION OBJECT OF THE INVENTION
[007] A cet effet, et selon un premier aspect, l'invention propose un dispositif pour piloter le taux de compression d'un moteur à rapport volumétrique variable, comprenant un vérin de commande comprenant un piston délimitant deux chambres destinées à recevoir un fluide sous pression, un accumulateur de pression délivrant le fluide sous pression, un premier circuit fluidique reliant la chambre supérieure à l'accumulateur et comprenant un premier ensemble de vanne apte à commander l'écoulement du fluide dans ledit premier circuit fluidique, un deuxième circuit fluidique reliant la chambre inférieure à l'accumulateur et comprenant un deuxième ensemble de vanne apte à commander l'écoulement d'un fluide dans ledit deuxième circuit fluidique, caractérisé en ce que l'un des circuits fluidiques au moins comporte un conduit de dérivation arrangé pour raccorder l'une des chambres à l'accumulateur, ledit conduit de dérivation comprenant un clapet anti-retour arrangé pour bloquer l'écoulement du fluide depuis la chambre vers l'accumulateur. [007] For this purpose, and according to a first aspect, the invention proposes a device for controlling the compression ratio of a variable volumetric ratio engine comprising a control cylinder comprising a piston defining two chambers for receiving a fluid. under pressure, a pressure accumulator delivering the fluid under pressure, a first fluid circuit connecting the upper chamber to the accumulator and comprising a first valve assembly adapted to control the flow of fluid in said first fluid circuit, a second fluid circuit connecting the lower chamber to the accumulator and comprising a second valve assembly adapted to control the flow of a fluid in said second fluid circuit, characterized in that at least one of the fluidic circuits comprises a bypass duct arranged for connect one of the chambers to the accumulator, said bypass duct comprising a non-return valve arranged for block the flow of fluid from the chamber to the accumulator.
[008] La présence d'un circuit de dérivation (ou circuit secondaire) comprenant un clapet anti-retour ainsi arrangé permet de pallier la chute de pression des chambres en dessous de la pression de l'accumulateur en cas de présence de micro-fuites au niveau de l'une des chambres en permettant le re-gavage de la chambre concernée par la chute de pression. Le circuit de dérivation permet ainsi de garantir une pression moyenne dans les chambres au moins égale à la pression de l'accumulateur, permettant ainsi d'obtenir des oscillations du vérin de commande au cours d'un cycle dans des valeurs acceptables (de l'ordre de 3 millimètres). [008] The presence of a branch circuit (or secondary circuit) comprising a non-return valve thus arranged makes it possible to overcome the pressure drop of the chambers below the pressure of the accumulator in the event of the presence of micro-leaks at one of the chambers allowing the re-feeding of the chamber concerned by the pressure drop. The bypass circuit thus makes it possible to guarantee an average pressure in the chambers at least equal to the pressure of the accumulator, thus making it possible to obtain oscillations of the control jack during a cycle in acceptable values (of the order of 3 millimeters).
[009] Avantageusement, le conduit de dérivation est arrangé pour réaliser un circuit parallèle au circuit fluidique de la chambre auquel le conduit de dérivation est raccordé. Plus particulièrement, le clapet anti retour est monté en parallèle du circuit fluidique. [009] Advantageously, the bypass duct is arranged to produce a circuit parallel to the fluid circuit of the chamber to which the bypass duct is connected. More particularly, the nonreturn valve is connected in parallel with the fluidic circuit.
[0010] Avantageusement, le conduit de dérivation est arrangé pour raccorder la chambre inférieure à l'accumulateur. [0011] Avantageusement, chaque circuit fluidique comporte un circuit de dérivation comportant un clapet anti-retour. Advantageously, the bypass duct is arranged to connect the lower chamber to the accumulator. Advantageously, each fluidic circuit comprises a bypass circuit comprising a nonreturn valve.
[0012] Avantageusement, le premier ensemble de vanne et le deuxième ensemble de vanne sont reliés à l'accumulateur par un conduit commun. [0012] Advantageously, the first valve assembly and the second valve assembly are connected to the accumulator by a common conduit.
[0013] Avantageusement, les premier et deuxième circuits fluidiques et les premier et deuxième ensembles de vanne sont arrangés avec un actionneur magnétique pour former une électrovanne permettant une ouverture et une fermeture simultanée des chambres supérieure et inférieure auxquelles Γ électrovanne est raccordée. Advantageously, the first and second fluidic circuits and the first and second valve assemblies are arranged with a magnetic actuator to form a solenoid valve for simultaneous opening and closing of the upper and lower chambers to which the solenoid valve is connected.
[0014] Selon un autre aspect, l'invention concerne une électrovanne comprenant deux ensembles de vanne destinées à commander respectivement l'écoulement d'un fluide délivré sous pression par un accumulateur de pression, chaque ensemble de vanne comportant un corps de vanne comprenant un canal longitudinal d'axe A A communiquant avec au moins deux circuits fluidiques et un arrangement formant soupape comprenant un piston monté mobile à l'intérieur du canal entre une position d'ouverture des circuits fluidiques pour permettre le passage du fluide d'un circuit fluidique à l'autre et une position de fermeture des circuits fluidiques l'un par rapport à l'autre, ledit piston comprenant une portion d'extrémité magnétisable et une extrémité, opposée à la portion d'extrémité magnétisable, formant un clapet apte à s'appuyer contre un siège pour provoquer la position de fermeture, et un actionneur électromagnétique unique apte à commander de manière simultanée le déplacement du piston de chaque ensemble de vanne dans la position d'ouverture des circuits fluidiques, l'actionneur, interposé entre les deux ensembles de vannes, comportant une bobine électromagnétique présentant un alésage de bobine logeant une cible magnétisable fixe s'étendant en vis-à-vis des portions d'extrémité magnétisables des pistons de chaque ensemble de vanne, caractérisée en ce qu'au moins l'un des circuits fluidiques de l'électrovanne comporte un conduit de dérivation pourvu d'un clapet anti-retour arrangé pour bloquer l'écoulement du fluide en direction de l'accumulateur. [0015] Selon d'autres caractéristiques avantageuses et non limitatives de Γ électrovanne, prises seules ou selon toutes combinaison techniquement réalisables : According to another aspect, the invention relates to a solenoid valve comprising two valve assemblies intended to respectively control the flow of a fluid delivered under pressure by a pressure accumulator, each valve assembly comprising a valve body comprising a longitudinal channel AA axis communicating with at least two fluidic circuits and a valve arrangement comprising a piston mounted movably within the channel between an open position of the fluidic circuits to allow the passage of fluid from a fluid circuit to the other and a closed position of the fluid circuits with respect to each other, said piston comprising a magnetizable end portion and an end opposite the magnetizable end portion, forming a valve adapted to press against a seat to cause the closed position, and a single electromagnetic actuator able to control the simultaneous movement the piston of each valve assembly in the open position of the fluidic circuits, the actuator interposed between the two sets of valves, comprising an electromagnetic coil having a coil bore housing a fixed magnetizable target extending with respect to the magnetizable end portions of the pistons of each valve assembly, characterized in that at least one of the fluid circuits of the solenoid valve comprises a bypass duct provided with a non-return valve arranged to lock the flow of the fluid towards the accumulator. According to other advantageous and non-limiting characteristics of the solenoid valve, taken alone or in any combination technically feasible:
- le clapet anti-retour est monté en parallèle du circuit fluidique auquel il est raccordé,  the non-return valve is connected in parallel with the fluid circuit to which it is connected,
- le clapet anti-retour est monté en parallèle de la partie du circuit fluidique reliant le canal à l'accumulateur,  the non-return valve is mounted in parallel with the part of the fluidic circuit connecting the channel to the accumulator,
- - chaque circuit fluidique comporte un circuit de dérivation comportant un clapet anti-retour. Et lorsque Γ électrovanne est associée à un vérin de commande comprenant deux chambres (une chambre inférieure et une chambre supérieure) délimitées par un piston :  each fluidic circuit comprises a bypass circuit comprising a non-return valve. And when the solenoid valve is associated with a control cylinder comprising two chambers (a lower chamber and an upper chamber) delimited by a piston:
- le conduit de dérivation est arrangé pour réaliser un circuit parallèle au circuit fluidique de la chambre auquel le conduit de dérivation est raccordé.  the bypass duct is arranged to produce a circuit parallel to the fluid circuit of the chamber to which the bypass duct is connected.
- le conduit de dérivation est arrangé pour raccorder la chambre inférieure du vérin de commande à l'accumulateur.- les premier et deuxième circuits fluidiques et les premier et deuxième ensembles de vanne sont arrangés avec un actionneur magnétique pour former une électrovanne permettant une ouverture et une fermeture simultanée des chambres supérieure et inférieure auxquelles Γ électrovanne est raccordée.  the bypass duct is arranged to connect the lower chamber of the control cylinder to the accumulator. The first and second fluid circuits and the first and second valve assemblies are arranged with a magnetic actuator to form a solenoid valve allowing an opening and simultaneous closing of the upper and lower chambers to which the solenoid valve is connected.
[0016] L'invention concerne également un moteur à rapport volumétrique variable comprenant un dispositif pour piloter le taux de compression tel que décrit précédemment. The invention also relates to a variable volumetric ratio engine comprising a device for controlling the compression ratio as described above.
[0017] Du fait de la présence d'un circuit de dérivation, la présence de micro-fuites sans risque d'altération du fonctionnement du dispositif de pilotage de taux de compression permet de tolérer la présence d'une micro-fuite dans l'une des chambres. Le fait de tolérer la présence d'une micro-fuite offre de nombreux avantages. En premier lieu, cela permet de réduire la précision de pièces à usiner et donc de réduire les coûts de fabrication. Cela permet ensuite d'augment la tolérance à l'usure. Enfin cela permet de réduire la cavitation en chambre inférieure, lorsque la micro-fuite a lieu en chambre supérieure. BREVE DESCRIPTION DES FIGURES Due to the presence of a bypass circuit, the presence of micro-leaks without risk of altering the operation of the compression ratio control device allows to tolerate the presence of a micro-leak in the one of the bedrooms. The fact of tolerating the presence of micro-leakage offers many advantages. In the first place, this reduces the precision of workpieces and thus reduces manufacturing costs. This then increases the wear tolerance. Finally this reduces the cavitation in the lower chamber, when the micro-leakage takes place in the upper chamber. BRIEF DESCRIPTION OF THE FIGURES
[0018] D'autres objets et avantages de l'invention apparaîtront au cours de la description qui suit, faite en référence aux dessins annexés, dans lesquels : Other objects and advantages of the invention will become apparent from the following description, made with reference to the accompanying drawings, in which:
- la figure 1 représente une vue schématique d'un dispositif de pilotage de taux de compression de l'art antérieur mis en œuvre pour piloter le taux de compression d'un moteur à rapport volumétrique variable ; - la figure 2 montre la courbe de pression sur plusieurs cycles moteur (720° vilebrequin) lorsque le dispositif de pilotage de la figure 1 présente une micro-fuite ; - Figure 1 shows a schematic view of a compression ratio control device of the prior art implemented to control the compression ratio of a variable volumetric ratio engine; - Figure 2 shows the pressure curve over several engine cycles (720 ° crankshaft) when the control device of Figure 1 has a micro-leakage;
- la figure 3 montre les courbes de pression sur plusieurs cycles moteur (720° vilebrequin) lorsque le dispositif de pilotage de la figure 1 ne présente pas de micro-fuite ; - la figure 4 représente une vue schématique d'un dispositif de pilotage de taux de compression selon l'invention destiné à être mis en œuvre pour piloter le taux de compression d'un moteur à rapport volumé trique variable, lorsque le dispositif de pilotage de taux de compression est en position ouverte ; FIG. 3 shows the pressure curves over several engine cycles (720 ° crankshaft) when the piloting device of FIG. 1 does not exhibit micro-leakage; FIG. 4 represents a schematic view of a compression ratio control device according to the invention intended to be implemented to control the compression ratio of a variable volume ratio engine, when the control device of compression ratio is in open position;
- la figure 5 représente une schématisation du dispositif de pilotage de la figure 4 ; - les figures 6 et 7 représentent le dispositif de pilotage de taux de compression de la figure 4 en position fermée, le clapet anti-retour étant respectivement en position fermée et ouverte. FIG. 5 represents a schematization of the control device of FIG. 4; - Figures 6 and 7 show the compression ratio control device of Figure 4 in the closed position, the non-return valve being respectively in the closed position and open.
- La figure 8 montre les courbes de pression sur un cycle moteur (720° vilebrequin) lorsque Γ électrovanne à double sens comporte un circuit secondaire de re-gavage en fluide pourvu d'un clapet anti-retour. [0019] Pour plus de clarté, les éléments identiques ou similaires des différents modes de réalisation sont repérés par des signes de référence identiques sur l'ensemble des figures. FIG. 8 shows the pressure curves on an engine cycle (720 ° crankshaft) when the two-way solenoid valve comprises a secondary fluid recirculation circuit provided with a non-return valve. For clarity, identical or similar elements of the different embodiments are identified by identical reference signs throughout the figures.
DESCRIPTION DETAILLEE DES FIGURES DETAILED DESCRIPTION OF THE FIGURES
[0020] En relation avec les figures 4 à 8, il est décrit un dispositif de pilotage de taux de compression destiné à être mis en œuvre pour piloter le taux de compression d'un moteur à rapport volumétrique variable du type par exemple de celui décrit dans la demande WO2008/148948. In relation to FIGS. 4 to 8, a compression rate control device is described which is intended to be used to control the compression ratio of a variable volumetric ratio engine of the type for example of that described. in the application WO2008 / 148948.
[0021] Le dispositif de pilotage de taux de compression comprend un vérin de commande 110 comprenant un piston délimitant deux chambres, une chambre dite supérieure 113 et une chambre dite inférieure 112, destinées à être alimentées en fluide hydraulique sous pression, en l'espèce de l'huile, en provenance d'un accumulateur de pression 33. Pour ce faire, un premier circuit fluidique 31 A, 32A reliant la chambre supérieure à l'accumulateur et comprenant un premier ensemble de vanne 4A, un deuxième circuit fluidique 31B, 32Breliant la chambre inférieure à l'accumulateur et comprenant un deuxième ensemble de vanne 4B. The compression ratio control device comprises a control cylinder 110 comprising a piston defining two chambers, a so-called upper chamber 113 and a so-called lower chamber 112, intended to be supplied with hydraulic fluid under pressure, in this case oil, from a pressure accumulator 33. To do this, a first fluid circuit 31A, 32A connecting the upper chamber to the accumulator and comprising a first valve assembly 4A, a second fluid circuit 31B, 32Breaking the room less than the accumulator and comprising a second valve assembly 4B.
[0022] Dans l'exemple illustré, les deux circuits fluidiques et les deux ensembles de vanne sont arrangées avec un actionneur magnétique 5 pour former une électrovanne 1 du type de celle décrite dans la demande WO2016/097546, permettant l'ouverture et la fermeture simultanée des chambres supérieure et inférieure. In the illustrated example, the two fluidic circuits and the two valve assemblies are arranged with a magnetic actuator 5 to form a solenoid valve 1 of the type described in WO2016 / 097546, allowing the opening and closing simultaneous upper and lower chambers.
[0023] L' électrovanne 1 ne sera pas décrite ci-après en détail. Elle reprend cependant l'ensemble des caractéristiques de Γ électrovanne décrite dans la demande susvisée. De manière générale cependant, l'électrovanne 1 comprend deux ensembles de vanne 2A, 2B de commande de l'écoulement d'un fluide et un actionneur 5 électromagnétique unique interposé entre les deux ensembles de vannes. The solenoid valve 1 will not be described hereinafter in detail. However, it includes all the characteristics of the solenoid valve described in the aforementioned application. In general, however, the solenoid valve 1 comprises two fluid flow control valve assemblies 2A, 2B and a single electromagnetic actuator interposed between the two valve assemblies.
[0024] Chaque ensemble de vanne 2A, 2B comporte un corps de vanne comprenant un canal 30 A, 30B longitudinal d'axe A A communiquant avec au moins deux conduits fluidiques 31 A, 32A, 31B, 32B. Les canaux 30 A, 30B sont débouchant du côté de Γ actionneur 5 et fermés du côté opposé à l'actionneur. Les conduits fluidiques 31 A, 32A, 31B, 32B sont ménagés sur les parois latérales des canaux 30, 30B. Le conduit fluidique 31A de l'électrovanne 1 est relié à la chambre supérieure 113 du vérin de commande tandis que le conduit fluidique 31B est relié à la chambre inférieure 112 du vérin de commande. Le canal 32A est relié quant à lui à l'accumulateur de pression 33, tandis que le conduit 32B est fermé en extrémité. Afin d'assurer le passage du fluide de la chambre inférieure 112 à la chambre supérieure 113 du vérin de commande et inversement, les conduits fluidiques 32A, 32B sont reliés entre eux par un canal commun 34. Each valve assembly 2A, 2B comprises a valve body comprising a channel 30A, 30B longitudinal axis A A communicating with at least two fluidic conduits 31A, 32A, 31B, 32B. The channels 30A, 30B are opening on the actuator side 5 and closed on the opposite side to the actuator. The fluidic conduits 31A, 32A, 31B, 32B are formed on the side walls of the channels 30, 30B. The fluid conduit 31A of the solenoid valve 1 is connected to the upper chamber 113 of the control cylinder while the fluid conduit 31B is connected to the lower chamber 112 of the control cylinder. The channel 32A is connected to the pressure accumulator 33 while the conduit 32B is closed at the end. In order to ensure the passage of the fluid from the lower chamber 112 to the upper chamber 113 of the control cylinder and vice versa, the fluidic conduits 32A, 32B are interconnected by a common channel 34.
[0025] Chaque ensemble de vanne comprend en outre un arrangement formant soupape. L'arrangement formant soupape comprend un piston 4A, 4B présentant un corps tubulaire monté mobile à l'intérieur du canal 30 A, 30B entre une position d'ouverture des conduits fluidiques 31A, 32A, 31B, 32B pour permettre le passage du fluide d'un conduit fluidique à l'autre et une position de fermeture des conduits fluidiques 31A, 32A, 31B, 32B l'un par rapport à l'autre. Plus particulièrement, chaque piston 4A, 4B présente une extrémité 41A, 41B apte à s'appuyer contre un siège 13A, 13B ménagé au niveau de l'extrémité du canal 30A, 30B associé la plus éloignée de l'actionneur 5 (i.e. au niveau de l'extrémité fermée du canal), et ainsi fermer les conduits fluidiques. L'extrémité 41A, 41B forme ainsi un clapet. On parlera par la suite de clapets pilotés. Une ouverture et des orifices sont ménagés respectivement au niveau de l'extrémité 41 A, 41B et du corps tubulaire des pistons 4A, 4B pour permettre le passage du fluide à l'intérieur de ces derniers. Les conduits fluidiques 31 A, 31B sont arrangés pour déboucher dans les canaux 30A, 30B en vis-à-vis de la portion de paroi du piston pourvue des orifices tandis que les conduits fluidiques 32A, 32B sont arrangés pour déboucher dans les canaux 30 A, 30B à proximité de l'extrémité fermée du canal correspondant. Each valve assembly further comprises a valve arrangement. The valve arrangement comprises a piston 4A, 4B having a tubular body movably mounted within the channel 30A, 30B between an opening position of the fluidic conduits 31A, 32A, 31B, 32B to allow the passage of fluid from the a fluidic conduit to another and a closed position of the fluid conduits 31A, 32A, 31B, 32B relative to each other. More particularly, each piston 4A, 4B has an end 41A, 41B adapted to bear against a seat 13A, 13B formed at the end of the channel 30A, 30B associated furthest from the actuator 5 (ie at the closed end of the channel), and thus close the fluidic conduits. The end 41A, 41B thus forms a valve. We will talk about pilot flaps later. An opening and orifices are provided respectively at the level of the end 41A, 41B and the tubular body of the pistons 4A, 4B to allow the passage of the fluid inside the latter. The fluidic conduits 31A, 31B are arranged to open into the channels 30A, 30B opposite the wall portion of the piston provided with the orifices while the fluidic conduits 32A, 32B are arranged to open into the channels 30A. , 30B near the closed end of the corresponding channel.
[0026] L'actionneur électromagnétique 5 comprend une bobine électromagnétique 6 cylindrique présentant un alésage de bobine et une pièce constituant une cible magnétisable 8, avantageusement en alliage magnétisable ferreux, comme par exemple un alliage fer/cobalt, un alliage fer/silicium ou autres, montée fixe dans ledit alésage. Lorsque chaque piston se déplace sous la commande de l'actionneur électromagnétique pour passer de la position de fermeture des conduits fluidiques à la position d'ouverture desdits conduits fluidiques, chaque piston 4A, 4B se déplace dans le canal correspondant en direction de la pièce cible pour venir en butée contre la face d'extrémité correspondante de la pièce cible 8. The electromagnetic actuator 5 comprises a cylindrical electromagnetic coil 6 having a coil bore and a piece constituting a magnetizable target 8, preferably made of ferrous magnetizable alloy, such as an iron / cobalt alloy, an iron / silicon alloy or other fixedly mounted in said bore. When each piston moves under the control of the electromagnetic actuator to move from the closed position of the fluidic conduits to the open position of said fluid conduits, each piston 4A, 4B moves in the corresponding channel towards the target piece to abut against the corresponding end face of the target piece 8.
[0027] L' électrovanne 1 constitue ainsi une électrovanne à double sens assurant l'ouverture ou la fermeture du circuit fluidique des deux ensembles de vanne 2A, 2B par déplacement simultané des deux pistons 4A, 4B sous l'impulsion du champ magnétique créé dans la bobine 6. Le chemin 36 du fluide est similaire à celui d'un dispositif de pilotage sans clapet tel qu'illustré sur la figure 1. Le pilotage du taux de compression du moteur s'effectue par le biais de la commande du passage du fluide sous pression d'une chambre à l'autre du vérin de commande 110, et inversement à l'aide de l'électrovanne 1. The solenoid valve 1 thus constitutes a two-way solenoid valve for opening or closing the fluid circuit of the two valve assemblies 2A, 2B by simultaneous displacement of the two pistons 4A, 4B under the impulse of the magnetic field created in FIG. 6. The path 36 of the fluid is similar to that of a control device without valve as shown in Figure 1. The control of the compression ratio of the engine is effected by means of the control of the passage of the pressurized fluid from one chamber to the other of the control cylinder 110, and vice versa using the solenoid valve 1.
[0028] Le dispositif de pilotage comporte en outre un conduit dit de dérivation 50 comprenant un clapet anti-retour (51) permettant le re-gavage d'une des chambres en cas de micro-fuites générant des micro-fuites de fluide de l'une desdites chambres. The control device further comprises a so-called bypass conduit 50 comprising a check valve (51) for the re-gavage of one of the chambers in case of micro-leaks generating micro-fluid leaks from the one of said chambers.
[0029] Dans le mode de réalisation illustré, le conduit de dérivation 50 est arrangé pour raccorder le conduit fluidique menant à la chambre inférieure au conduit fluidique menant à l'accumulateur. Il constitue ainsi un conduit de dérivation 50 du deuxième circuit fluidique (ou circuit fluidique inférieur). Le conduit de dérivation 50 est arrangé pour réaliser ainsi un circuit parallèle au circuit fluidique de la chambre auquel le conduit de dérivation 50 est raccordé. In the illustrated embodiment, the bypass duct 50 is arranged to connect the fluid duct leading to the lower chamber to the fluid duct leading to the accumulator. It thus constitutes a bypass duct 50 of the second fluid circuit (or lower fluid circuit). The bypass duct 50 is arranged to thereby provide a circuit parallel to the fluid circuit of the chamber to which the bypass duct 50 is connected.
[0030] Les figures 6 et 7 représentent l'électrovanne en position fermée. Dans le cas normal, i.e. en l'absence de micro-fuites au niveau du vérin et donc de micro-fuite, la pression de la chambre basse du vérin est supérieure à la pression d'accumulateur. Dans ce cas, le clapet anti-retour 51 , disposé en parallèle du clapet 41B piloté, reste fermé (figure 6). Lorsque Γ électrovanne est fermée et que la chambre supérieure présente une micro-fuite, le premier pic de pression en chambre qui suit la fermeture a pour effet de faire chuter la pression de la chambre inférieure (à l'instant de la fermeture, la situation des pressions est la même que celle la situation précédant la fermeture). Lorsque celle-ci chute en dessous de la pression de l'accumulateur, le clapet anti-retour 51 , en parallèle du clapet 41B piloté, s'ouvre, permettant alors l'introduction d'un volume complémentaire de fluide dans la chambre inférieure du vérin et ainsi l'augmentation de la pression dans le vérin de commande. En quelques cycles, il peut être constaté une remontée de la pression moyenne dans le vérin. Si le vérin ne fuit pas, hormis une micro-fuite, et que le clapet anti-retour 51 présente une réactivité suffisante, on peut parvenir à une pression minimale dans la chambre inférieure égale à la pression d'alimentation. Cela permet ainsi de garantir une pression minimale dans le vérin de commande malgré la présence d'une petite fuite en chambre supérieure. Par ailleurs, cela tend à améliorer la stabilité du dispositif de pilotage de taux de compression grâce à la remontée de la pression moyenne dans le vérin de commande. Figures 6 and 7 show the solenoid valve in the closed position. In the normal case, ie in the absence of micro-leaks at the cylinder and therefore micro-leakage, the pressure of the lower chamber of the cylinder is greater than the accumulator pressure. In this case, the non-return valve 51, arranged in parallel with the flap 41B piloted, remains closed (FIG. 6). When the solenoid valve is closed and the upper chamber has a micro-leakage, the first pressure peak in the chamber after the closure has the effect of lowering the pressure of the lower chamber (at the moment of closure, the situation pressure is the same as the situation before closure). When the latter falls below the pressure of the accumulator, the non-return valve 51, in parallel with the controlled valve 41B, opens, allowing then the introduction of a complementary volume of fluid into the lower chamber of the cylinder and thus the increase of the pressure in the control cylinder. In a few cycles, it can be seen a rise in the average pressure in the cylinder. If the cylinder does not leak, except for a micro-leak, and the check valve 51 has a sufficient reactivity, one can achieve a minimum pressure in the lower chamber equal to the supply pressure. This ensures a minimum pressure in the control cylinder despite the presence of a small leak in the upper chamber. Moreover, this tends to improve the stability of the compression ratio control device by increasing the average pressure in the control cylinder.
[0031] La figure 8 montre les courbes de pression sur un cycle moteur (720° vilebrequin) lorsque l'électrovanne à double sens comporte un circuit secondaire de re-gavage en fluide pourvu d'un clapet anti-retour 51. On peut constater alors qu'avec la présence du circuit de dérivation 50, la pression dans les chambres est rehaussée. FIG. 8 shows the pressure curves on an engine cycle (720 ° crankshaft) when the two-way solenoid valve comprises a secondary fluid re-gavage circuit provided with a non-return valve 51. It can be seen that while with the presence of the branch circuit 50, the pressure in the chambers is raised.
[0032] Dans l'exemple illustré, le conduit de dérivation 50 est prévu pour re-gaver la chambre inférieure 112. Il s'agit d'un mode de réalisation préférentiel. Il est bien entendu évident que l'invention ne se limite pas à cet arrangement, et qu'il peut être prévu un dispositif de pilotage de taux de compression avec un circuit de dérivation 50 prévu pour re-gaver la chambre supérieure 113. Ainsi, le conduit de dérivation 50 comprenant le clapet anti-retour 51 est arrangé pour raccorder le conduit fluidique menant à la chambre supérieure au conduit fluidique menant à l'accumulateur. Il constitue ainsi un conduit de dérivation 50 du premier circuit fluidique (ou circuit fluidique supérieur). In the illustrated example, the bypass duct 50 is provided to re-fill the lower chamber 112. This is a preferred embodiment. It is of course obvious that the invention is not limited to this arrangement, and that a compression rate control device may be provided with a bypass circuit 50 provided for re-gassing the upper chamber 113. Thus, the bypass duct 50 comprising the non-return valve 51 is arranged to connect the fluid duct leading to the upper chamber to the fluid duct leading to the accumulator. It thus constitutes a bypass duct 50 of the first fluid circuit (or upper fluid circuit).
[0033] De même, il peut être prévu, sans sortir du cadre de l'invention, un dispositif de contrôle de taux de compression comprenant un arrangement combiné des deux circuits de dérivation 50 précédemment décrits de sorte à permettre le re-gavage de l'une ou l'autre des chambres. [0034] L'invention est décrite dans ce qui précède à titre d'exemple. Il est entendu que l'homme du métier est à même de réaliser différentes variantes de réalisation de l'invention sans pour autant sortir du cadre de l'invention. Similarly, it may be provided, without departing from the scope of the invention, a compression rate control device comprising a combined arrangement of the two bypass circuits 50 previously described so as to allow the re-feeding of the one or the other of the rooms. The invention is described in the foregoing by way of example. It is understood that the skilled person is able to achieve different embodiments of the invention without departing from the scope of the invention.

Claims

REVENDICATIONS Dispositif pour piloter le taux de compression d'un moteur à rapport volumétrique variable, comprenant un vérin de commande (110) comprenant un piston (111) délimitant deux chambres (112, 113) destinées à recevoir un fluide sous pression, un accumulateur de pression (33) délivrant le fluide sous pression, un premier circuit fluidique (31A, 32A) reliant la chambre supérieure (113) à l'accumulateur et comprenant un premier ensemble de vanne (2 A) apte à commander l'écoulement du fluide dans ledit premier circuit fluidique, un deuxième circuit fluidique (31B, 32B) reliant la chambre inférieure (112) à l'accumulateur (33) et comprenant un deuxième ensemble de vanne (2B) apte à commander l'écoulement d'un fluide dans ledit deuxième circuit fluidique, caractérisé en ce que l'un des circuits fluidiques au moins comporte un conduit de dérivation (50) arrangé pour raccorder l'une des chambres (112, 113) à l'accumulateur (33), ledit conduit de dérivation comprenant un clapet anti -retour (51) arrangé pour bloquer l'écoulement du fluide depuis la chambre (112, 113) vers l'accumulateur (33). Dispositif pour piloter le taux de compression selon la revendication 1 , caractérisé en ce que le conduit de dérivation (50) est arrangé pour réaliser un circuit parallèle au circuit fluidique de la chambre auquel le conduit de dérivation (50) est raccordé. Dispositif pour piloter le taux de compression selon la revendication 1 ou la revendication 2, caractérisé en ce que le conduit de dérivation (50) est arrangé pour raccorder la chambre inférieure (112) à l'accumulateur (33). Dispositif pour piloter le taux de compression selon l'une quelconque des revendications précédentes, caractérisé en ce que chaque circuit fluidique (31A, 32A, 31B, 32B) comporte un circuit de dérivation (50) comportant un clapet anti-retour. Dispositif pour piloter le taux de compression selon l'une quelconque des revendications précédentes, caractérisé en ce que le premier ensemble de vanne (2A) et le deuxième ensemble de vanne (2B) sont reliées à l'accumulateur (33) par un conduit commun (34). Dispositif pour piloter le taux de compression selon l'une quelconque des revendications précédentes, caractérisé en ce que en ce que les premier et deuxième circuits fluidiques (31 A, 32A, 31B, 32B) et les premier et deuxième ensembles de vanne (2A, 2B) sont arrangées avec un actionneur magnétique (8) pour former une électrovanne permettant une ouverture et une fermeture simultanée des chambres supérieure et inférieure auxquelles l'électrovanne est raccordée. Electrovanne (1) comprenant deux ensembles de vanne (2A, 2B) destinées à commander chacune l'écoulement d'un fluide délivré sous pression par un accumulateur de pression, chaque ensemble de vanne (2A, 2B) comportant un corps de vanne comprenant un canal (30A, 30B) longitudinal d'axe AA communiquant avec au moins deux circuits fluidiques (31 A, 32A, 31B, 32B) et un arrangement formant soupape comprenant un piston (4A, 4B) monté mobile à l'intérieur du canal (30A, 30B) entre une position d'ouverture des circuits fluidiques (31 A, 32A, 31B, 32B) pour permettre le passage du fluide d'un circuit fluidique à l'autre et une position de fermeture des circuits fluidiques (31 A, 32A, 31B, 32B) l'un par rapport à l'autre, ledit piston (4A, 4B) comprenant une portion d'extrémité magnétisable et une extrémité, opposée à la portion d'extrémité magnétisable, formant un clapet apte à s'appuyer contre un siège (13A, 13B) pour provoquer la position de fermeture, et un actionneur électromagnétique (5) unique apte à commander de manière simultanée le déplacement du piston (4A, 4B) de chaque ensemble de vanne dans la position d'ouverture des circuits fluidiques (31A, 32A, 31B, 32B), l'actionneur, interposé entre les deux ensembles de vannes, comportant une bobine électromagnétique (6) présentant un alésage de bobine logeant une cible magnétisable (8) fixe s 'étendant en vis-à-vis des portions d'extrémité magnétisables des pistons (4A, 4B) de chaque ensemble de vanne (2A, 2B), caractérisée en ce qu'au moins l'un des circuits fluidiques de l'électrovanne comporte un conduit de dérivation (50) pourvu d'un clapet anti-retour (51) arrangé pour bloquer l'écoulement du fluide en direction de l'accumulateur. Electrovanne selon la revendication 7, caractérisée en ce que le clapet anti-retour (51) est monté en parallèle du circuit fluidique (31 A, 32A, 31B, 32B) auquel il est raccordé. Electrovanne selon la revendication 7 ou la revendication 8, caractérisée en ce que le clapet anti-retour (51) est monté en parallèle de la partie du circuit fluidique (32A, 32B) reliant le canal (30A, 30B) à l'accumulateur. Electrovanne selon l'une quelconque des revendications 7 à 9, caractérisée en ce que chaque circuit fluidique (31 A, 32A, 31B, 32B) comporte un circuit de dérivation comportant un clapet anti-retour (51). Claims A device for controlling the compression ratio of a variable compression ratio engine, comprising a control cylinder (110) comprising a piston (111) delimiting two chambers (112, 113) intended to receive a pressurized fluid, an accumulator pressure (33) delivering the fluid under pressure, a first fluid circuit (31A, 32A) connecting the upper chamber (113) to the accumulator and comprising a first valve assembly (2 A) adapted to control the flow of fluid in said first fluid circuit, a second fluid circuit (31B, 32B) connecting the lower chamber (112) to the accumulator (33) and comprising a second valve assembly (2B) adapted to control the flow of fluid in said second fluid circuit, characterized in that at least one of the fluidic circuits comprises a bypass duct (50) arranged to connect one of the chambers (112, 113) to the accumulator (33), said bypass duct with an anti-return valve (51) arranged to block the flow of fluid from the chamber (112, 113) to the accumulator (33). Device for controlling the compression ratio according to claim 1, characterized in that the bypass duct (50) is arranged to produce a circuit parallel to the fluid circuit of the chamber to which the bypass duct (50) is connected. Device for controlling the compression ratio according to claim 1 or claim 2, characterized in that the bypass duct (50) is arranged to connect the lower chamber (112) to the accumulator (33). Device for controlling the compression ratio according to any one of the preceding claims, characterized in that each fluid circuit (31A, 32A, 31B, 32B) comprises a bypass circuit (50) comprising a non-return valve. Device for controlling the compression ratio according to any one of the preceding claims, characterized in that the first valve assembly (2A) and the second valve assembly (2B) are connected to the accumulator (33) via a common conduit (34). Device for controlling the compression ratio according to any one of the preceding claims, characterized in that the first and second fluid circuits (31A, 32A, 31B, 32B) and the first and second valve assemblies (2A, 2B) are arranged with a magnetic actuator (8) to form a solenoid valve for simultaneous opening and closing of the upper and lower chambers to which the solenoid valve is connected. A solenoid valve (1) comprising two valve assemblies (2A, 2B) for controlling each the flow of a fluid delivered under pressure by a pressure accumulator, each valve assembly (2A, 2B) having a valve body comprising a longitudinal channel (30A, 30B) AA axis communicating with at least two fluidic circuits (31A, 32A, 31B, 32B) and a valve arrangement comprising a piston (4A, 4B) movably mounted within the channel ( 30A, 30B) between an opening position of the fluidic circuits (31A, 32A, 31B, 32B) to allow the passage of the fluid from one fluid circuit to the other and a closed position of the fluidic circuits (31A, 32A, 31B, 32B) relative to each other, said piston (4A, 4B) comprising a magnetizable end portion and an end opposite the magnetizable end portion, forming a valve adapted to pressing against a seat (13A, 13B) to cause the closed position, and an actuator electromagnet (5) capable of simultaneously controlling the displacement of the piston (4A, 4B) of each valve assembly in the opening position of the fluidic circuits (31A, 32A, 31B, 32B), the actuator interposed between the two sets of valves, comprising an electromagnetic coil (6) having a coil bore housing a fixed magnetizable target (8) extending opposite the magnetizable end portions of the pistons (4A, 4B) of each valve assembly (2A, 2B), characterized in that at least one of the fluidic circuits of the solenoid valve comprises a bypass duct (50) provided with a non-return valve (51) arranged to block the flow of the fluid towards the accumulator. Solenoid valve according to claim 7, characterized in that the non-return valve (51) is connected in parallel with the fluid circuit (31A, 32A, 31B, 32B) to which it is connected. Solenoid valve according to Claim 7 or Claim 8, characterized in that the non-return valve (51) is connected in parallel with the portion of the fluid circuit (32A, 32B) connecting the channel (30A, 30B) to the accumulator. Solenoid valve according to any one of claims 7 to 9, characterized in that each fluid circuit (31A, 32A, 31B, 32B) comprises a bypass circuit comprising a non-return valve (51).
1. Moteur à rapport volumétrique variable comprenant un dispositif pour piloter le taux de compression selon l'une quelconque des revendications 1 à 6. A variable volumetric ratio motor comprising a device for controlling the compression ratio according to any one of claims 1 to 6.
EP18709712.6A 2017-03-01 2018-02-28 Device for controlling the compression rate of a variable compression ratio engine, comprising a two-way solenoid valve provided with a secondary circuit for fluid refilling Pending EP3589828A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
FR1751686A FR3063518B1 (en) 2017-03-01 2017-03-01 DEVICE FOR CONTROLLING THE COMPRESSION RATE OF A VARIABLE COMPRESSOR RATIO ENGINE COMPRISING A TWO-WAY SOLENOID VALVE PROVIDED WITH A SECONDARY FLUID RE-BOOSTING CIRCUIT
PCT/FR2018/050469 WO2018158539A1 (en) 2017-03-01 2018-02-28 Device for controlling the compression rate of a variable compression ratio engine, comprising a two-way solenoid valve provided with a secondary circuit for fluid refilling

Publications (1)

Publication Number Publication Date
EP3589828A1 true EP3589828A1 (en) 2020-01-08

Family

ID=59381358

Family Applications (1)

Application Number Title Priority Date Filing Date
EP18709712.6A Pending EP3589828A1 (en) 2017-03-01 2018-02-28 Device for controlling the compression rate of a variable compression ratio engine, comprising a two-way solenoid valve provided with a secondary circuit for fluid refilling

Country Status (5)

Country Link
US (1) US10830160B2 (en)
EP (1) EP3589828A1 (en)
CN (1) CN110573715A (en)
FR (1) FR3063518B1 (en)
WO (1) WO2018158539A1 (en)

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR3104209B1 (en) 2019-12-05 2022-06-03 MCE 5 Development hydraulic control system for a variable compression ratio engine

Family Cites Families (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1102513B (en) * 1952-10-08 1961-03-16 Siam Solenoid control valve
JPS60101295A (en) * 1983-11-08 1985-06-05 Sanden Corp Compression capacity varying type scroll compressor
DE4203362C2 (en) * 1992-02-06 1994-02-17 Piv Antrieb Reimers Kg Werner Tapered disk gear, in particular for motor vehicles
DE19731402A1 (en) * 1997-07-22 1999-01-28 Wabco Gmbh Solenoid valve device
JP3945419B2 (en) * 2003-02-24 2007-07-18 日産自動車株式会社 Reciprocating variable compression ratio engine
DE102005043726B4 (en) * 2005-03-14 2014-05-28 Continental Teves Ag & Co. Ohg Solenoid valve
FR2914951B1 (en) * 2007-04-16 2012-06-15 Vianney Rabhi ELECTROHYDRAULIC DEVICE FOR CLOSED LOOP DRIVING OF THE CONTROL JACK OF A VARIABLE COMPRESSION RATE MOTOR.
FR2933141B1 (en) * 2008-06-27 2011-11-11 Vianney Rabhi SCREW BALL LIFTING DEVICE FOR VARIABLE COMPRESSION RATE MOTOR.
FR2969705B1 (en) * 2010-12-23 2014-04-04 Vianney Rabhi TUBULAR VALVE FOR CONTROLLING AN ENGINE WITH VARIABLE VOLUMETRIC RATIO
FR3030010B1 (en) * 2014-12-15 2018-02-09 MCE 5 Development SOLENOID VALVE COMPRISING TWO INDEPENDENT FLUIDIC CIRCUITS AND SEALS, CONTROLLED BY A SINGLE ELECTROMAGNETIC ACTUATOR, AND MOTOR COMPRISING SUCH A SOLENOID VALVE
US9506382B2 (en) * 2015-03-30 2016-11-29 Caterpillar Inc. Variable valve actuator

Also Published As

Publication number Publication date
FR3063518B1 (en) 2022-01-07
FR3063518A1 (en) 2018-09-07
WO2018158539A1 (en) 2018-09-07
US10830160B2 (en) 2020-11-10
US20200011254A1 (en) 2020-01-09
CN110573715A (en) 2019-12-13

Similar Documents

Publication Publication Date Title
EP3524866B1 (en) Fluid valve
BE1010985A3 (en) Hydraulic system including a valve mounting handset setting / locking and regeneration.
FR2933471A1 (en) BALANCED ELECTRO-HYDRAULIC VALVE FOR A VARIABLE COMPRESSION RATE MOTOR HYDRAULIC CONTROL UNIT
FR2819021A1 (en) Hydraulic operation of jet valve in fuel injector for diesel engines, uses hydraulic amplifier to transmit piezoelectric actuator force to injector needle
FR2738048A1 (en) SOLENOID VALVE, PARTICULARLY FOR A HYDRAULIC BRAKING SYSTEM WITH SKATING CONTROL FOR A MOTOR VEHICLE
WO2016097546A1 (en) Electromagnetic valve comprising two independent and sealed fluid circuits controlled by a single electromagnetic actuator, and motor comprising such an electromagnetic valve
FR3013401A1 (en) HYDRAULIC VALVE ARRANGEMENT WITH CONTROL / ADJUSTMENT FUNCTION
FR2723159A1 (en) ADJUSTABLE HYDRAULIC SHOCK ABSORBER
EP3589828A1 (en) Device for controlling the compression rate of a variable compression ratio engine, comprising a two-way solenoid valve provided with a secondary circuit for fluid refilling
EP2935863A1 (en) Nozzle, high-pressure valve able to accept the nozzle and common rail able to accept the nozzle
FR3014524A1 (en) PRESSURE LIMIT VALVE
WO2008012704A2 (en) Hydropneumatic regenerative actuator
EP2891825A2 (en) Telescopic actuator
FR2918121A1 (en) Common ramp fuel injector for internal combustion engine, includes control chamber, control valve element sliding in valve chamber and pressure reduction valve in partial chamber
EP2126334B1 (en) Fuel injector for internal combustion engine
EP3026310A1 (en) Solenoid valve for cryogenic high-pressure gas
WO2018158540A1 (en) Device for controlling the compression ratio of an engine with variable compression ratio comprising a two-way solenoid valve having controlled permanent leakage
FR2468812A1 (en) DISTRIBUTION VALVE WITH ELECTROMAGNETIC MANEUVER DEVICE
FR2870914A1 (en) Hydraulic valve installation for use in hydrostatic driving system, has damping side outlet functioning for pressure limitation function of installation and not functioning at opening and closing of installation for reaspiration function
FR2954806A1 (en) Electro-magnetic operated control valve i.e. quantity control valve, for controlling flow rate of petrol high-pressure pump, has rotor arranged in rotor chamber, and disk-shaped residual air gap disk arranged between rotor and body stop
FR2566352A1 (en) BRAKE EFFORT HYDRAULIC AMPLIFIER
FR2756349A1 (en) Hydraulic directional control valve used in lifting engines or buckets in dredgers
FR2908834A1 (en) Fuel injector for e.g. diesel engine, of motor vehicle, has chamber with inlet and outlet orifices that are in fluid communication with fuel supplying orifice and injection orifice, respectively, and maintaining spring cooperated with case
EP2872784B1 (en) Device for controlling the movement of a hydraulic cylinder, particularly for hydraulic machines
FR3037377A1 (en) DYNAMIC PRESSURE REGULATOR

Legal Events

Date Code Title Description
STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: UNKNOWN

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

Free format text: STATUS: THE INTERNATIONAL PUBLICATION HAS BEEN MADE

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

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

Free format text: STATUS: REQUEST FOR EXAMINATION WAS MADE

17P Request for examination filed

Effective date: 20190827

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR

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

Free format text: STATUS: EXAMINATION IS IN PROGRESS

17Q First examination report despatched

Effective date: 20220401