EP2090758A1 - Lubrication circuit - Google Patents
Lubrication circuit Download PDFInfo
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- EP2090758A1 EP2090758A1 EP09151591A EP09151591A EP2090758A1 EP 2090758 A1 EP2090758 A1 EP 2090758A1 EP 09151591 A EP09151591 A EP 09151591A EP 09151591 A EP09151591 A EP 09151591A EP 2090758 A1 EP2090758 A1 EP 2090758A1
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- European Patent Office
- Prior art keywords
- oil
- valve
- combustion engine
- circuit
- internal combustion
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01M—LUBRICATING OF MACHINES OR ENGINES IN GENERAL; LUBRICATING INTERNAL COMBUSTION ENGINES; CRANKCASE VENTILATING
- F01M1/00—Pressure lubrication
- F01M1/16—Controlling lubricant pressure or quantity
Definitions
- the invention relates to a lubrication circuit of an internal combustion engine.
- the circuit described in the present invention has a device for regulating the pressure of the oil despite the variations in viscosity of the latter.
- an internal combustion engine In operation, an internal combustion engine involves many moving mechanical elements. To prevent wear of moving parts, as well as to limit friction and associated energy losses, these parts must be lubricated.
- the engine therefore comprises a lubricant circuit responsible for supplying oil to the various components of the engine to be lubricated.
- At least one positive displacement pump ensures adequate oil circulation in the circuit. It may be a pump mechanically actuated by the engine, or an electric pump, or a set of several pumps of similar or different technologies.
- this valve In order to regulate the pressure in the circuit to a sufficient but not excessive level, there is traditionally a discharge valve in parallel with the pump, which makes it possible to return the excess oil in the circuit upstream of the oil pump.
- this valve which can be a ball valve closed by a calibrated spring, opens, allowing a return of the oil upstream of the pump and a regulation of the pressure to the desired level .
- the viscosity of the oil traditionally used for the lubrication of an internal combustion engine varies significantly with its temperature.
- the oil circuit relief valve is sized to perform its function most of the time, i.e. within a given oil viscosity range corresponding to the viscosity of the hot engine oil. .
- the viscosity of the oil being higher at low temperature, when the oil is cold, the valve does not allow sufficient opening to return enough oil upstream of the pump and thus maintain the oil pressure close to the pressure hot regulation.
- the cold oil pressure is unnecessarily high in the circuit, which generates significant energy losses and an increase in engine consumption. Note that the increase of the passage section of the valve is not a solution, because the regulation of hot pressure would then be effective.
- KUBOTA adds a second discharge valve in parallel with the first valve.
- This second valve is actuated by a thermostatic element.
- this valve has a virtually “all or nothing" opening, which is incompatible with a fine regulation of the pressure in the circuit.
- this solution only functions correctly over a reduced oil viscosity range, thus for an extremely reduced operating temperature range.
- the object of the present invention is to provide a device allowing a fine regulation of the oil pressure in the lubricant circuit, over the entire operating temperature range of an engine, that is to say generally from -30 ° C to 140 ° C, and therefore over the entire viscosity range of the oil as part of its use for the lubrication of an internal combustion engine.
- the solution to this problem is to use a special constitution device positioned in a branch of parallel unloading of the discharge valve, allowing, depending on the temperature of the oil or the pressure in the circuit, to return a suitable portion of the oil upstream of the pump, to allow the discharge valve to play are fine regulating role of the pressure in the circuit.
- the device in parallel with the discharge valve can be, according to different variants of the invention, a variable-section valve or a solenoid valve.
- a valve with a variable section is thus positioned in parallel with the discharge valve, in a branch of load shedding of the valve.
- the valve in play consists of two chambers, these chambers being at least partially contained in one another or adjacent, the first chamber being in communication with the oil circuit on one side of the pump, typically downstream (respectively upstream), and the second chamber being in communication with the circuit on the other side of the pump, typically upstream (respectively downstream).
- the two chambers are in communication via one or more orifices substantially slit-shaped.
- a piston more or less discovers this orifice, thus varying the passage section between the two chambers.
- the piston is actuated in the invention by a thermostatic element, whose expansion is substantially proportional to the temperature. Its position therefore varies almost linearly with temperature. If the gap between the two chambers had a constant width (rectangular shape seen from the front), the passage surface would then evolve in proportion to the temperature of the oil. However, the viscosity of the oil does not evolve linearly with temperature, but substantially hyperbolic, it is preferable to adapt the shape of the slot so that the passage section changes proportionally to the viscosity of the oil and not at its temperature.
- the slot may therefore have a substantially trapezoidal shape, seen from the front, or a more elaborate form (hyperbolic section) allowing a perfect match between the opening of the valve and the viscosity of the oil.
- a solenoid valve is positioned in parallel with the discharge valve.
- the solenoid valve is controlled by a control system.
- the solenoid valve can operate "all or nothing", that is to say do not have a variable section.
- the regulation of the amount of oil returned by the solenoid valve upstream of the pump is achieved by imposing on the valve a succession of opening and closing.
- the section of the valve is known, or, for better accuracy, a calibrated fitting can be positioned in the branch of the circuit.
- the command applied to the solenoid valve can be predetermined according to the conditions of speed and oil temperature, that is to say with an open loop control system.
- the RCO control will be performed in closed loop.
- the circuit must have a proportional pressure sensor, which gives the control system of the valve information on the pressure in the circuit.
- the pressure sensor is positioned in the lubrication circuit at the engine inlet.
- the oil circuit of an internal combustion engine comprises in particular a main branch passing through an oil tank 1 serving as a reservoir for containing the lubricating oil 2, and a pump 3 ensuring the circulation of the oil 2 in the circuit .
- a pump 3 ensuring the circulation of the oil 2 in the circuit .
- the latter therefore generates a pressure difference between the upstream part 5 of the main branch and the downstream part 6 of the main branch, with respect to said pump.
- the passage section of this valve ensures good regulation when the lubricating oil is hot. When cold, the viscosity of the oil may be too great for the valve to properly perform its function.
- the figure 9 shows us how much the viscosity of the oil is dependent on its temperature. On the abscissa is the temperature of the oil considered in degrees Celsius (° C), the ordinate is carried the viscosity of this oil in centipoises (cPs) according to a logarithmic scale.
- the line curve continuous corresponds to an automotive oil type 10W-40, while the dotted line corresponds to a type 5W-30 automotive oil.
- an internal combustion engine can be operated throughout this temperature range, that is -30 ° C during a cold start in extreme conditions at 140 ° C hot .
- the only discharge valve 4 can not be sized to ensure a fine regulation of the oil pressure over all of this range of temperature and viscosity, it is proposed in the invention shown figure 2 to provide the circuit of a load shedding branch 11 in parallel with the discharge valve 4 and to equip this shedding branch 11 with a device 7 for unloading the discharge valve 4 from an adequate part of the oil to return upstream of the pump 3 to allow a fine regulation of the oil pressure in the lubricant circuit by the valve 4, and this over the entire operating temperature range of an engine, that is to say generally say -30 ° C to 140 ° C.
- variable section valve 71 is provided in the lubricating circuit in parallel with the discharge valve 4.
- variable section valve is actuated by a thermostatic element 8.
- valve 71 When cold, the valve 71 is open and closes as the temperature of the oil rises. When the oil is hot enough, the valve is completely closed, and only the relief valve 4 regulates the pressure of the oil in the circuit.
- the figure 4 presents an optional embodiment of this variant of the invention.
- the circuit in the branch incorporating the variable-section valve 71 that is to say the branch parallel to the discharge valve 4, is associated with a safety solenoid valve 9 making it possible to close this branch in case blocking valve of the variable section 71, which may for example be caused by a failure of the thermostatic element 8.
- a blocking of the variable section valve 71 in the open position would prevent obtaining sufficient pressure to the good lubrication of the hot engine, which would jeopardize its proper functioning and could quickly lead to a mechanical failure, or even destruction.
- the safety solenoid valve 9 if the pressure detected in the downstream circuit 6 of the pump 3 is low, falls, or barely established, the safety solenoid valve 9 is closed.
- variable opening valve device 71 One of the major points of this variant of the invention is the adoption of a variable opening valve device 71.
- Known devices performing this type of function are often complex control, or may be influenced by the level sudden pressure.
- variable opening valve thus proposed consists of two chambers 711 and 712 located respectively downstream and upstream of the oil pump 3.
- An orifice 713 allows communication between these two chambers.
- a piston 714 makes it possible to more or less obstruct this orifice 713.
- the piston 714 is thus moved in translation in the chamber 711 by the action of a thermostatic element 8.
- a thermostatic element 8 Such an element is perfectly known in the prior art. This is usually a simple piece made of a material that expands under the effect of temperature.
- the orifice 713 may have an oblong shape. One can thus speak of slot to designate the orifice 713.
- variable opening valve is open.
- the piston 714 completely uncovers the orifice 713. This is the configuration of the valve when the oil is cold and therefore highly viscous.
- the oil has begun to heat, but is not sufficiently hot and fluid that the only relief valve 5 is sufficient to satisfactorily regulate the pressure in the circuit.
- the valve has a reduced passage section with respect to the figure 5 but is not yet completely closed.
- the orifice 713 is partially covered by the piston 714.
- the figure 9 shows that the viscosity variation of the oil as a function of its temperature is absolutely not proportional. However, it is desired that the passage section of the variable opening valve (section of the orifice 713 discovered by the piston 714) varies proportionally to this viscosity.
- the shape of the orifice 713 ' is adapted to respond to this constraint.
- the passage section first evolves slowly, while the viscosity evolves rapidly. The higher the temperature of the oil rises, the more the passage section will grow rapidly because of its shape.
- the proposed device makes it possible to effectively vary the passage section in proportion to the evolution of the viscosity of the oil.
- said discharge valve 4 can then correctly play its role of pressure regulator despite the high viscosity of the oil.
- a solenoid valve 72 is arranged in the lubrication circuit, in parallel with the discharge valve 4.
- This solenoid valve 72 is controlled by a control means 721, which can control the opening and closing of the valve 72.
- the control means 72 can control the opening and closing of the valve 72 in an open loop, according to criteria of oil temperature and engine speed.
- control means 721 can control the opening and closing of the valve 72 in an open loop with a control of the "RCO” type (Cyclic Opening Ratio), according to a map predetermined.
- RCO Cyclic Opening Ratio
- control means 721 can control the opening and closing of the valve 72 in a closed loop with a "RCO" type control (Cyclic Opening Ratio), according to a third embodiment of this second variant.
- a pressure information in the circuit obtained by a proportional pressure sensor, preferably positioned in the circuit between the oil filter and the engine.
- the figure 10 represents the result achieved by the present invention on a typical automotive application.
- On the abscissa is the engine speed in revolutions per minute, the ordinate the pressure of the oil in bar in the circuit downstream of the pump.
- the curve with diamonds corresponds to the pressure of the hot oil, that is to say when the optimum operating temperature of the engine has been reached and is regulated by the cooling circuit.
- the relief valve 4 plays its regulating role and makes it possible to stabilize the oil pressure in the circuit at a desired and adequate level, here of the order of 4 bars.
- This pressure curve represents an ideal curve, which one seeks to reproduce whatever the viscosity of the oil.
- the curve with squares corresponds to the pressure of the cold oil, that is to say with an oil at 20 ° C in our example, without the invention, that is to say in the configuration presented. to the figure 1 .
- the relief valve does not have a sufficient section to allow passage of the amount of oil required to regulate the pressure of the circuit. In fact, at low speeds, the pressure is set at an unnecessarily high level. energy dissipated in the pump and in the circuit is then important, which generates overconsumption of the engine.
- the curve with triangles corresponds to the pressure of the cold oil in a circuit according to the invention, as shown in FIG. figure 6 .
- the pressure is at a level slightly higher than it is hot. This is due to the pressure drops in the branch of the circuit presenting the variable opening valve in parallel with the discharge valve.
- the invention makes it possible to follow a pressure profile close to the ideal. As the oil temperature increases and its viscosity decreases, the variable opening valve will close. The pressure will then gradually reach the hot pressure profile.
- the invention thus described thus makes it possible to maintain an adequate pressure in the circuit in all operating situations of the engine, and over the entire typical working range of oil temperature and viscosity.
Abstract
Description
L'invention porte sur un circuit de lubrification d'un moteur à combustion interne. En particulier, le circuit décrit dans la présente invention présente un dispositif permettant de réguler la pression de l'huile malgré les variations de viscosité de cette dernière.The invention relates to a lubrication circuit of an internal combustion engine. In particular, the circuit described in the present invention has a device for regulating the pressure of the oil despite the variations in viscosity of the latter.
Lors de son fonctionnement, un moteur à combustion interne met en jeu de nombreux éléments mécaniques en mouvement. Afin de prévenir l'usure des pièces en mouvement, ainsi que pour limiter les frottements et les pertes d'énergie associées, ces pièces doivent être lubrifiées. Le moteur comporte donc un circuit de lubrifiant chargé d'alimenter en huile les différentes pièces constitutives du moteur devant être lubrifiées.In operation, an internal combustion engine involves many moving mechanical elements. To prevent wear of moving parts, as well as to limit friction and associated energy losses, these parts must be lubricated. The engine therefore comprises a lubricant circuit responsible for supplying oil to the various components of the engine to be lubricated.
Notons que le lubrifiant traditionnellement employé dans un moteur à combustion interne étant généralement de l'huile, nous utilisons ces deux termes de façon équivalente.Note that the lubricant traditionally used in an internal combustion engine is usually oil, we use these two terms in an equivalent way.
Au moins une pompe volumétrique permet d'assurer une circulation d'huile adéquate dans le circuit. Il peut s'agir d'une pompe actionnée mécaniquement par le moteur, ou d'une pompe électrique, voire d'un ensemble de plusieurs pompes de technologies analogues ou différentes.At least one positive displacement pump ensures adequate oil circulation in the circuit. It may be a pump mechanically actuated by the engine, or an electric pump, or a set of several pumps of similar or different technologies.
Afin de réguler la pression dans le circuit à un niveau suffisant mais pas excessif, on dispose traditionnellement un clapet de décharge en parallèle de la pompe, ce qui permet de renvoyer l'huile excédentaire dans le circuit en amont de la pompe à huile. Lorsque la pression adéquate est dépassée dans le circuit, ce clapet, pouvant être un clapet à bille fermé par un ressort taré, s'ouvre, permettant un retour de l'huile en amont de la pompe et une régulation de la pression au niveau souhaité.In order to regulate the pressure in the circuit to a sufficient but not excessive level, there is traditionally a discharge valve in parallel with the pump, which makes it possible to return the excess oil in the circuit upstream of the oil pump. When the adequate pressure is exceeded in the circuit, this valve, which can be a ball valve closed by a calibrated spring, opens, allowing a return of the oil upstream of the pump and a regulation of the pressure to the desired level .
Il est par ailleurs connu que la viscosité de l'huile traditionnellement utilisée pour la lubrification d'un moteur à combustion interne varie de façon importante avec sa température. Cependant, le clapet de décharge du circuit d'huile est dimensionné pour remplir sa fonction la plus grande partie du temps, c'est-à-dire dans une plage de viscosité d'huile donnée correspondant à la viscosité de l'huile moteur chaud.It is also known that the viscosity of the oil traditionally used for the lubrication of an internal combustion engine varies significantly with its temperature. However, the oil circuit relief valve is sized to perform its function most of the time, i.e. within a given oil viscosity range corresponding to the viscosity of the hot engine oil. .
La viscosité de l'huile étant plus importante à basse température, lorsque l'huile est froide, le clapet ne permet pas une ouverture suffisante retourner suffisamment d'huile en amont de la pompe et maintenir ainsi la pression d'huile proche de la pression de régulation à chaud.The viscosity of the oil being higher at low temperature, when the oil is cold, the valve does not allow sufficient opening to return enough oil upstream of the pump and thus maintain the oil pressure close to the pressure hot regulation.
La pression d'huile à froid est donc inutilement élevée dans le circuit, de qui génèrent des pertes énergétiques importantes et une augmentation de la consommation du moteur. Notons que l'augmentation de la section de passage du clapet n'est pas une solution, car la régulation de pression à chaud serait alors peut efficace.The cold oil pressure is unnecessarily high in the circuit, which generates significant energy losses and an increase in engine consumption. Note that the increase of the passage section of the valve is not a solution, because the regulation of hot pressure would then be effective.
Le brevet
L'objet de la présente invention est de proposer un dispositif permettant une régulation fine de la pression d'huile dans le circuit de lubrifiant, sur toute la plage de température de fonctionnement d'un moteur, c'est-à-dire généralement de -30°C à 140°C, et donc sur toute la plage de viscosité de l'huile dans le cadre de son utilisation pour la lubrification d'un moteur à combustion interne.The object of the present invention is to provide a device allowing a fine regulation of the oil pressure in the lubricant circuit, over the entire operating temperature range of an engine, that is to say generally from -30 ° C to 140 ° C, and therefore over the entire viscosity range of the oil as part of its use for the lubrication of an internal combustion engine.
Dans l'invention, la solution à ce problème consiste à utiliser un dispositif de constitution particulière positionné dans une branche de délestage en parallèle du clapet de décharge, permettant, en fonction de la température de l'huile ou de la pression dans le circuit, de retourner une partie adéquate de l'huile en amont de la pompe, afin de permettre au clapet de décharge de jouer sont rôle de régulation fine de la pression dans le circuit.In the invention, the solution to this problem is to use a special constitution device positioned in a branch of parallel unloading of the discharge valve, allowing, depending on the temperature of the oil or the pressure in the circuit, to return a suitable portion of the oil upstream of the pump, to allow the discharge valve to play are fine regulating role of the pressure in the circuit.
Le dispositif en parallèle du clapet de décharge peut être, selon différentes variantes de l'invention, une vanne à section variable ou une électrovanne.The device in parallel with the discharge valve can be, according to different variants of the invention, a variable-section valve or a solenoid valve.
Dans une première variante, une vanne à section variable est ainsi positionnée en parallèle du clapet de décharge, dans une branche de délestage du clapet. Préférentiellement, la vanne mise en jeu est constituée de deux chambres, ces chambres étant au moins partiellement contenues l'une dans l'autre ou adjacentes, la première chambre étant en communication avec le circuit d'huile d'un côté de la pompe, typiquement en aval (respectivement en amont), et la seconde chambre étant en communication avec le circuit de l'autre côté de la pompe, typiquement en amont (respectivement en aval).In a first variant, a valve with a variable section is thus positioned in parallel with the discharge valve, in a branch of load shedding of the valve. Preferably, the valve in play consists of two chambers, these chambers being at least partially contained in one another or adjacent, the first chamber being in communication with the oil circuit on one side of the pump, typically downstream (respectively upstream), and the second chamber being in communication with the circuit on the other side of the pump, typically upstream (respectively downstream).
Les deux chambres sont en communication par l'intermédiaire d'un ou plusieurs orifices sensiblement en forme de fentes. Un piston découvre plus ou moins cet orifice, faisant ainsi varier la section de passage entre les deux chambres.The two chambers are in communication via one or more orifices substantially slit-shaped. A piston more or less discovers this orifice, thus varying the passage section between the two chambers.
Le piston est actionné dans l'invention par un élément thermostatique, dont la dilatation est sensiblement proportionnelle à la température. Sa position varie donc de façon quasiment linéaire avec la température. Si la fente ménagée entre les deux chambres avait une largeur constante (forme rectangulaire vue de face), la surface de passage évoluerait alors proportionnellement à la température de l'huile. Ors, la viscosité de l'huile n'évoluant pas linéairement avec la température, mais de façon sensiblement hyperbolique, il convient préférentiellement d'adapter la forme de la fente afin que la section de passage évolue proportionnellement à la viscosité de l'huile et non à sa température.The piston is actuated in the invention by a thermostatic element, whose expansion is substantially proportional to the temperature. Its position therefore varies almost linearly with temperature. If the gap between the two chambers had a constant width (rectangular shape seen from the front), the passage surface would then evolve in proportion to the temperature of the oil. However, the viscosity of the oil does not evolve linearly with temperature, but substantially hyperbolic, it is preferable to adapt the shape of the slot so that the passage section changes proportionally to the viscosity of the oil and not at its temperature.
La fente pourra donc avoir une forme sensiblement trapézoïdale, vue de face, ou une forme plus élaborée (section hyperbolique) permettant une parfaite adéquation entre l'ouverture de la vanne et la viscosité de l'huile.The slot may therefore have a substantially trapezoidal shape, seen from the front, or a more elaborate form (hyperbolic section) allowing a perfect match between the opening of the valve and the viscosity of the oil.
De manière optionnelle, on peut garantir la sécurité de fonctionnement de l'invention dans cette première variante en ajoutant une électrovanne en série avec la vanne thermostatique afin d'obturer le circuit de décharge supplémentaire en cas de blocage de l'élément thermostatique.Optionally, it is possible to guarantee the operational safety of the invention in this first variant by adding a solenoid valve in series with the thermostatic valve in order to close off the additional discharge circuit in the event of blockage of the thermostatic element.
Dans une seconde variante de l'invention, une électrovanne est positionnée en parallèle du clapet de décharge. L'électrovanne est pilotée par un système de commande.In a second variant of the invention, a solenoid valve is positioned in parallel with the discharge valve. The solenoid valve is controlled by a control system.
L'électrovanne peut fonctionner en « tout ou rien », c'est-à-dire ne pas présenter une section variable. Dans ce cas, la régulation de la quantité de d'huile retournée par l'électrovanne vers l'amont de la pompe est réalisée en imposant à la vanne une succession d'ouverture et de fermeture. La section de la vanne est connue, ou, pour une meilleure précision, un ajustage calibré peut être positionné dans la branche du circuit.The solenoid valve can operate "all or nothing", that is to say do not have a variable section. In this case, the regulation of the amount of oil returned by the solenoid valve upstream of the pump is achieved by imposing on the valve a succession of opening and closing. The section of the valve is known, or, for better accuracy, a calibrated fitting can be positioned in the branch of the circuit.
La commande appliquée à l'électrovanne peut être prédéterminée selon les conditions de régime et de température d'huile c'est-à-dire avec un système de pilotage en boucle ouverte.The command applied to the solenoid valve can be predetermined according to the conditions of speed and oil temperature, that is to say with an open loop control system.
Pour avoir un pilotage fin de la pression, on peut adopter un pilotage dit « RCO », pour « rapport cyclique d'ouverture ». C'est un type de pilotage tout à fait classique pour des électrovannes. Avec ce type de pilotage, on obtient en ouvrant et en fermant successivement l'électrovanne sur une période donnée une section d'ouverture équivalente à ce que l'on aurait obtenu avec une vanne à section variable partiellement ouverte. Pour vulgariser ce type de pilotage, on peut considérer qu'une vanne en tout ou rien présentant une certaine section de passage et ouverte la moitié du temps sur une période donnée est équivalente à une vanne proportionnelle de section maximale égale et à moitié ouverte sur cette même période.To have a fine control of the pressure, one can adopt a steering called "RCO" for "opening duty cycle". This is a type of piloting quite classic for solenoid valves. With this type of piloting, we get by successively opening and closing the solenoid valve over a given period of time an opening section equivalent to what would have been obtained with a partially open valve section. To popularize this type of control, it can be considered that a valve in all or nothing having a certain passage section and open half the time over a given period is equivalent to a proportional valve of equal maximum section and half open on this same period.
Dans un mode RCO simple, il est possible de conserver un pilotage en boucle ouverte. Le rapport cyclique d'ouverture est alors cartographié une fois pour toute en fonction de la température de l'huile et du régime moteur.In a simple RCO mode, it is possible to keep an open loop control. The opening duty cycle is then mapped once and for all as a function of oil temperature and engine speed.
Préférentiellement, le pilotage RCO sera effectué en boucle fermée. Pour cela, le circuit doit comporter un capteur de pression proportionnel, qui donne au système de commande de la vanne une information sur la pression dans le circuit.Preferably, the RCO control will be performed in closed loop. For this, the circuit must have a proportional pressure sensor, which gives the control system of the valve information on the pressure in the circuit.
Idéalement, le capteur de pression est positionné dans le circuit de lubrification à l'entrée du moteur.Ideally, the pressure sensor is positioned in the lubrication circuit at the engine inlet.
Ceci offre un avantage supplémentaire à cette variante de l'invention. En effet, la pression vue par le clapet de décharge est quasiment la pression directement en aval de la pompe à huile. Plus loin dans le circuit, un filtre à huile permet séparer de l'huile les particules issues de l'usure des éléments mécaniques du moteur et le carbone généré par échauffement. Ce filtre peut générer une importante perte de charge dans le circuit, perte de charge qui est en outre variable dans le temps, puisqu'elle augmente avec le colmatage progressif du filtre.This offers an additional advantage to this variant of the invention. Indeed, the pressure seen by the discharge valve is almost the pressure directly downstream of the oil pump. Further in the circuit, an oil filter allows to separate from the oil the particles resulting from the wear of the mechanical elements of the engine and the carbon generated by heating. This filter can generate a significant loss of load in the circuit, pressure loss which is also variable in time, since it increases with the progressive clogging of the filter.
Ainsi, il est possible de piloter la pression dans le circuit effectivement présente à l'entrée du moteur.Thus, it is possible to control the pressure in the circuit actually present at the engine inlet.
L'invention est décrite plus en détail ci-après et en référence aux figures représentant schématiquement le système dans certains modes de réalisation préférentiels.
- La
figure 1 représente l'architecture globale du circuit d'huile d'un moteur à combustion interne autour de la pompe à huile et tel que connu dans l'art antérieur. - La
figure 2 représente l'architecture globale du circuit d'huile d'un moteur à combustion interne autour de la pompe à huile conformément à la présente invention. - La
figure 3 représente l'architecture globale du circuit d'huile d'un moteur à combustion interne autour de la pompe à huile conformément à la présente invention dans sa première variante. - La
figure 4 représente l'architecture globale du circuit d'huile d'un moteur à combustion interne autour de la pompe à huile conformément à la présente invention dans sa première variante sécurisée par une électrovanne. - La
figure 5 présente le principe du dispositif de vanne à section variable mis en jeu dans l'invention dans sa première variante, en position ouverte (grande section de passage) - La
figure 6 présente le principe du dispositif de vanne à section variable mis en jeu dans l'invention dans sa première variante, en position presque fermée (faible section de passage) - La
figure 7 présente le principe du dispositif de vanne à section variable mis en jeu dans l'invention dans sa première variante, avec une section de passage de forme optimisée pour varier proportionnellement à la viscosité de l'huile. - La
figure 8 représente l'architecture globale du circuit d'huile d'un moteur à combustion interne autour de la pompe à huile conformément à la présente invention dans sa seconde variante. - La
figure 9 présente l'évolution de viscosité en fonction de la température de deux huiles typiques pour la lubrification d'un moteur à combustion interne automobile. - La
figure 10 représente l'évolution de la pression dans le circuit en fonction du régime dans les trois cas suivants : à chaud, à froid selon l'art antérieur, à froid selon l'invention.
- The
figure 1 represents the overall architecture of the oil circuit of an internal combustion engine around the oil pump and as known in the prior art. - The
figure 2 represents the overall architecture of the oil circuit of an internal combustion engine around the oil pump according to the present invention. - The
figure 3 represents the overall architecture of the oil circuit of an internal combustion engine around the oil pump according to the present invention in its first variant. - The
figure 4 represents the overall architecture of the oil circuit of an internal combustion engine around the oil pump according to the present invention in its first variant secured by a solenoid valve. - The
figure 5 presents the principle of the variable-section valve device used in the invention in its first variant, in the open position (large passage section) - The
figure 6 presents the principle of the variable-section valve device used in the invention in its first variant, in an almost closed position (small passage section) - The
figure 7 presents the principle of the variable-section valve device used in the invention in its first variant, with a shaped passage section optimized to vary in proportion to the viscosity of the oil. - The
figure 8 represents the overall architecture of the oil circuit of an internal combustion engine around the oil pump according to the present invention in its second variant. - The
figure 9 presents the evolution of viscosity as a function of the temperature of two typical oils for the lubrication of an automobile internal combustion engine. - The
figure 10 represents the evolution of the pressure in the circuit according to the regime in the following three cases: hot, cold according to the prior art, cold according to the invention.
Le circuit d'huile d'un moteur à combustion interne comporte notamment une branche principale traversant un bac à huile 1 servant de réservoir pour contenir l'huile de lubrification 2, et une pompe 3 assurant la circulation de l'huile 2 dans le circuit. Selon les pertes de charges présentes en aval de la pompe 3, cette dernière génère donc une différence de pression entre la partie amont 5 de la branche principale et la partie aval 6 de la branche principale, par rapport à ladite pompe.The oil circuit of an internal combustion engine comprises in particular a main branch passing through an
Pour réguler la pression de la branche aval 6, il est connu de munir le circuit d'une branche retour entre l'aval 6 et l'amont 5 de la pompe 3, et de positionner sur cette branche retour un clapet de décharge 4. Il s'agit généralement d'un clapet à bille muni d'un ressort taré, prévu pour ne s'ouvrir qu'au-delà de la pression souhaitée dans la branche aval 6.To regulate the pressure of the
La section de passage de ce clapet permet d'assurer une bonne régulation lorsque l'huile lubrifiante est chaude. A froid, la viscosité de l'huile peut être trop importante pour que le clapet puisse correctement remplir son office. La
Globalement, on peut illustrer la variation de viscosité d'une huile en constatant qu'une huile est cinquante cinq fois plus visqueuse à -30°C qu'elle ne l'est à 20°C, et trente fois plus visqueuse à 20°C qu'elle ne l'est à 140°C.Overall, it is possible to illustrate the viscosity variation of an oil by observing that an oil is fifty-five times more viscous at -30 ° C than it is at 20 ° C, and thirty times more viscous at 20 ° C. C it is at 140 ° C.
Ors, un moteur à combustion interne peut être amené à fonctionner sur l'ensemble de cette plage de température, c'est-à-dire de -30°C lors d'un démarrage à froid en conditions extrêmes à 140°C à chaud.However, an internal combustion engine can be operated throughout this temperature range, that is -30 ° C during a cold start in extreme conditions at 140 ° C hot .
Par ailleurs, il faut constater que la variation de viscosité de l'huile est très loin d'être proportionnelle à sa température.Moreover, it should be noted that the viscosity variation of the oil is very far from being proportional to its temperature.
Le seul clapet de décharge 4 ne pouvant pas être dimensionné pour assurer une régulation fine de la pression d'huile sur l'ensemble de cette plage de température et de viscosités, il est proposé dans l'invention représentée
Dans une première variante de l'invention présentée en
La vanne à section variable est actionnée par un élément thermostatique 8.The variable section valve is actuated by a
A froid, la vanne 71 est ouverte, et se ferme au fur et à mesure de la montée en température de l'huile. Lorsque l'huile est suffisamment chaude, la vanne est totalement fermée, et seul le clapet de décharge 4 régule la pression de l'huile dans le circuit.When cold, the
La
Dans ce mode de réalisation, si la pression détectée dans le circuit en aval 6 de la pompe 3 est faible, chute, ou peine à s'établir, on ferme l'électrovanne de sécurité 9.In this embodiment, if the pressure detected in the
L'un des points majeurs de cette variante de l'invention consiste en l'adoption d'un dispositif de vanne à ouverture variable 71. Les dispositifs connus réalisant ce type de fonction sont souvent de pilotage complexe, ou peuvent être influencés par le niveau de pression subit. Il n'existe pas à l'heure actuelle dans un circuit de lubrification d'un moteur à combustion interne de dispositif répondant à ces exigences.One of the major points of this variant of the invention is the adoption of a variable
L'inventeur a ainsi conçu le dispositif dont le principe est exposé dans les
La vanne à ouverture variable ainsi proposée est constituée de deux chambres 711 et 712 situées respectivement en aval et en amont de la pompe à huile 3.The variable opening valve thus proposed consists of two
Un orifice 713 permet la communication entre ces deux chambres.An
Un piston 714 permet d'obstruer plus ou moins cet orifice 713. Le piston 714 est ainsi mu en translation dans la chambre 711 par l'action d'un élément thermostatique 8. Un tel élément est parfaitement connu dans l'art antérieur, il s'agit en général d'une pièce simple constituée d'un matériau se dilatant sous l'effet de la température.A
Afin d'obtenir une progressivité de la section de passage découverte par le piston et permettant le passage de l'huile de la chambre 711 à la chambre 712, l'orifice 713 peut présenter une forme oblongue. On peut ainsi parler de fente pour désigner l'orifice 713.In order to obtain a progressivity of the passage section uncovered by the piston and allowing the passage of the oil from the
Sur la
Sur la
Le principe d'ouverture de la vanne présenté sur les
La
Dans un mode de réalisation préférentiel schématisé sur la
Ainsi, en adoptant une forme adéquate, le dispositif proposé permet de faire effectivement varier la section de passage proportionnellement à l'évolution de la viscosité de l'huile. En délestant le clapet de décharge 4 d'une quantité adéquate d'huile, ledit clapet 4 de décharge peut alors jouer correctement son rôle de régulateur de pression malgré la grande viscosité de l'huile.Thus, by adopting a suitable form, the proposed device makes it possible to effectively vary the passage section in proportion to the evolution of the viscosity of the oil. By relieving the
Dans une seconde variante de l'invention présentée en
Cette électrovanne 72 est pilotée par un moyen de commande 721, pouvant commander l'ouverture et la fermeture de la vanne 72.This
Le moyen de commande 721, selon un premier mode de réalisation de cette seconde variante, peut commander l'ouverture et la fermeture de la vanne 72 en boucle ouverte, selon des critères de température d'huile et de régime moteur.The control means 721, according to a first embodiment of this second variant, can control the opening and closing of the
Selon un second mode de réalisation de cette seconde variante, le moyen de commande 721 peut commander l'ouverture et la fermeture de la vanne 72 en boucle ouverte avec un pilotage de type « RCO » (Rapport Cyclique d'Ouverture), selon une cartographie prédéterminée.According to a second embodiment of this second variant, the control means 721 can control the opening and closing of the
Enfin, selon un troisième mode de réalisation de cette seconde variante, le moyen de commande 721 peut commander l'ouverture et la fermeture de la vanne 72 en boucle fermée avec un pilotage de type « RCO » (Rapport Cyclique d'Ouverture), selon une information de pression dans le circuit obtenue par un capteur de pression proportionnel, préférentiellement positionné dans le circuit entre le filtre à huile et le moteur.Finally, according to a third embodiment of this second variant, the control means 721 can control the opening and closing of the
La
La courbe présentant des losanges correspond à la pression de l'huile à chaud, c'est-à-dire à lorsque la température optimale de fonctionnement du moteur a été atteinte et est régulée par le circuit de refroidissement. Dans ce cas, le clapet de décharge 4 joue son rôle de régulation et permet de stabiliser la pression d'huile dans le circuit à un niveau souhaité et adéquat, ici de l'ordre de 4 bars. Cette courbe de pression représente une courbe idéale, que l'on cherche à reproduire quelle que soit la viscosité de l'huile.The curve with diamonds corresponds to the pressure of the hot oil, that is to say when the optimum operating temperature of the engine has been reached and is regulated by the cooling circuit. In this case, the
La courbe présentant des carrés correspond à la pression de l'huile à froid, c'est-à-dire avec une huile à 20°C dans notre exemple, sans l'invention, c'est-à-dire dans la configuration présentée à la
La courbe présentant des triangles correspond à la pression de l'huile à froid dans un circuit conforme à l'invention, comme représenté sur la
L'invention ainsi décrite permet ainsi de maintenir une pression adéquate dans le circuit dans toutes les situations de fonctionnement du moteur, et sur toute la plage de travail typique de température de et de viscosité de l'huile.The invention thus described thus makes it possible to maintain an adequate pressure in the circuit in all operating situations of the engine, and over the entire typical working range of oil temperature and viscosity.
En garantissant un profil de pression adéquat, les risques de casse du moteur par manque de lubrification sont écartés, tout en évitant la surconsommation liée à une pression d'huile inutilement importante à froid.By guaranteeing an adequate pressure profile, the risk of engine failure due to lack of lubrication is avoided, while avoiding overconsumption due to unnecessarily high oil pressure when cold.
Claims (11)
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
FR0850891A FR2927358B1 (en) | 2008-02-13 | 2008-02-13 | LUBRICATION CIRCUIT. |
Publications (1)
Publication Number | Publication Date |
---|---|
EP2090758A1 true EP2090758A1 (en) | 2009-08-19 |
Family
ID=39797929
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP09151591A Withdrawn EP2090758A1 (en) | 2008-02-13 | 2009-01-29 | Lubrication circuit |
Country Status (2)
Country | Link |
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EP (1) | EP2090758A1 (en) |
FR (1) | FR2927358B1 (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP2602485A1 (en) * | 2011-12-05 | 2013-06-12 | MAN Truck & Bus AG | Adjustment device, in particular for motor vehicles |
Families Citing this family (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN102758767A (en) * | 2012-07-20 | 2012-10-31 | 安徽江淮汽车股份有限公司 | Oil circuit control system of saddle-shaped diesel oil tank |
Citations (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5339776A (en) * | 1993-08-30 | 1994-08-23 | Chrysler Corporation | Lubrication system with an oil bypass valve |
JPH0893430A (en) * | 1994-09-27 | 1996-04-09 | Nissan Motor Co Ltd | Lubrication system of internal combustion engine |
JPH0988533A (en) * | 1995-09-26 | 1997-03-31 | Tokyo Buhin Kogyo Kk | Engine lubricant oil feeder |
US20020172604A1 (en) * | 2001-05-17 | 2002-11-21 | Berger Alvin Henry | Variable pressure oil pump |
JP2004108157A (en) | 2002-09-13 | 2004-04-08 | Kubota Corp | Hydraulic regulating device for forced lubrication device in engine |
DE102006019086A1 (en) * | 2006-04-23 | 2007-10-31 | Att Automotivethermotech Gmbh | Pressure and flow regulation method for lubricating oil circuit of internal combustion engine, involves providing main-oil circuit-regulation circuit for regulation and/or limitation of oil flow rate in branches and/or oil pressure |
-
2008
- 2008-02-13 FR FR0850891A patent/FR2927358B1/en not_active Expired - Fee Related
-
2009
- 2009-01-29 EP EP09151591A patent/EP2090758A1/en not_active Withdrawn
Patent Citations (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5339776A (en) * | 1993-08-30 | 1994-08-23 | Chrysler Corporation | Lubrication system with an oil bypass valve |
JPH0893430A (en) * | 1994-09-27 | 1996-04-09 | Nissan Motor Co Ltd | Lubrication system of internal combustion engine |
JPH0988533A (en) * | 1995-09-26 | 1997-03-31 | Tokyo Buhin Kogyo Kk | Engine lubricant oil feeder |
US20020172604A1 (en) * | 2001-05-17 | 2002-11-21 | Berger Alvin Henry | Variable pressure oil pump |
JP2004108157A (en) | 2002-09-13 | 2004-04-08 | Kubota Corp | Hydraulic regulating device for forced lubrication device in engine |
DE102006019086A1 (en) * | 2006-04-23 | 2007-10-31 | Att Automotivethermotech Gmbh | Pressure and flow regulation method for lubricating oil circuit of internal combustion engine, involves providing main-oil circuit-regulation circuit for regulation and/or limitation of oil flow rate in branches and/or oil pressure |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP2602485A1 (en) * | 2011-12-05 | 2013-06-12 | MAN Truck & Bus AG | Adjustment device, in particular for motor vehicles |
Also Published As
Publication number | Publication date |
---|---|
FR2927358A1 (en) | 2009-08-14 |
FR2927358B1 (en) | 2010-02-12 |
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