FR3107306A1 - Electric assistance system of a combustion engine - Google Patents

Abstract

The invention relates to an electric assistance system for an engine comprising at least one camshaft movable in rotation around a first axis of rotation, at least one crankshaft movable in rotation around of a main axis of rotation and at least one distribution module arranged at one of the ends of the camshaft and configured to allow the crankshaft mobile in rotation around the main axis of rotation to drive said camshaft about said first axis of rotation, said system comprising at least: a. A motor electrical device; b. A mechanical coupling device; vs. A power source. Figure for abstract: Fig. 1

Description

Electric assistance system of a combustion engine

The present invention relates to the field of combustion engines. It finds a particularly advantageous application in the field of electric assistance of an internal combustion engine.

STATE OF THE ART

Combustion engines comprise one or more camshafts configured to be rotatable around an axis of rotation, and this independently of whether the engine is a 4-stroke, 2-stroke, diesel engine or not. More generally, any sequenced distribution driven by a crankshaft, including hydraulic or pneumatic, comprises one or more camshafts.

The camshaft is generally mechanically driven in rotation by a timing module comprising, for example, a timing belt, a chain, or a plurality of gears. This distribution module is mechanically coupled to a crankshaft. It is the crankshaft which, by its rotation around a main axis of rotation, drives the elements of the timing module, for example the timing belt, making it possible to drive the camshaft in rotation.

The camshaft has the function of synchronizing several movements, transforming its continuous rotational movement into alternating translational or alternating rotational movements. In particular, in the case of a valve, the movement is an alternating translational movement, while in the case of a rocker arm, it is an alternating rotational movement.

Generally, the camshaft is used in combustion engines to synchronize valves. However, the slippage of the valves in their conduit and the effort made to compress the valve reminders cause well-known friction problems, and therefore mechanical losses.

For example, while the engine may have a speed where it has little torque, it must nevertheless develop enough to overcome a plurality of mechanical resistances, i.e. mechanical losses. These mechanical losses are generally estimated at 25%. Indeed, this mechanical friction leads to an increase in the resistive torque of the camshaft, that is to say the torque of the camshaft generated by the mechanical resistance between the camshaft and the mechanical parts in friction with him.

An object of the present invention is therefore to propose a solution to the problem of the mechanical losses of combustion engines.

The other objects, features and advantages of the present invention will become apparent from a review of the following description and the accompanying drawings. It is understood that other benefits may be incorporated.

SUMMARY

1. Un dispositif électrique moteur comprenant au moins un arbre moteur mobile en rotation autour d’un deuxième axe de rotation, le système étant configuré pour que le dispositif électrique moteur coopère avec ledit arbre à cames de sorte à ce que la rotation de l’arbre moteur autour du deuxième axe de rotation entraîne en rotation l’arbre à cames autour du premier axe de rotation, de préférence simultanément à l’entraînement en rotation de l’arbre à cames autour du premier axe de rotation par le vilebrequin, le dispositif électrique moteur étant destiné à être alimenté par au moins une source d’alimentation électrique;
2. Un dispositif de couplage mécanique configuré pour assurer ladite coopération entre le dispositif électrique moteur et l’arbre à cames ;

L’arbre moteur étant configuré pour être continûment mobile en rotation autour du deuxième axe de rotation, de préférence dans un unique sens de rotation, lorsque le vilebrequin est mobile en rotation autour de l’axe de rotation principal.The present invention relates to an electric assistance system for an engine, preferably a combustion engine, the engine comprising at least one camshaft movable in rotation around a first axis of rotation, at least one crankshaft movable in rotation around a main axis of rotation and at least one distribution module, preferably arranged at one of the ends of the camshaft, and configured to allow the crankshaft mobile in rotation around the main axis of rotation to drive in rotation said camshaft around said first axis of rotation, said system comprising at least:

1. An electric motor device comprising at least one motor shaft movable in rotation about a second axis of rotation, the system being configured so that the electric motor device cooperates with said camshaft so that the rotation of the motor shaft around the second axis of rotation rotates the camshaft around the first axis of rotation, preferably simultaneously with the rotational drive of the camshaft around the first axis of rotation by the crankshaft, the electric motor device being intended to be powered by at least one electrical power source;
2. A mechanical coupling device configured to ensure said cooperation between the motor electrical device and the camshaft;

The motor shaft being configured to be continuously rotatable around the second axis of rotation, preferably in a single direction of rotation, when the crankshaft is rotatable around the main axis of rotation.

The present invention makes it possible to compensate for at least part of the mechanical losses linked, for example, to friction of moving parts driven in motion by the camshaft.

The present invention makes it possible to provide the camshaft with the torque necessary to at least partially overcome the mechanical resistance causing mechanical losses.

The present invention makes it possible to reduce fuel consumption in the case of a combustion engine for example.

The present invention provides an effective and inexpensive solution for reducing the mechanical losses of a preferably combustion engine.

According to one example, the engine shaft is configured to be rotatable around the second axis of rotation, only when the crankshaft is rotatable around the main axis of rotation.

According to one example, the engine shaft is configured to be always mobile in rotation around the second axis of rotation, when the crankshaft is mobile in rotation around the main axis of rotation.

According to one example, the electric motor device comprises an electric motor having an output shaft, the output shaft being the motor shaft.

The present invention also relates to an assembly for a combustion engine comprising a combustion engine and said electric assistance system of the combustion engine according to the present invention.

The present invention also relates to a motor vehicle comprising at least one assembly according to the present invention.

1. Détermination du couple résistant de l’arbre à cames ;
2. Pilotage du dispositif électrique moteur par au moins une unité de contrôle pour ajuster le couple résistant de l’arbre à cames.

The present invention finally relates to a method for adjusting the resistive torque of at least one camshaft of a combustion engine by an electric assistance system according to the present invention, the method comprising at least the following steps:

1. Determination of the camshaft resistive torque;
2. Control of the motor electrical device by at least one control unit to adjust the resistive torque of the camshaft.

The present invention also relates to a system configured for the implementation of the method according to the present invention.

BRIEF DESCRIPTION OF FIGURES

The aims, objects, as well as the characteristics and advantages of the invention will emerge better from the detailed description of an embodiment of the latter which is illustrated by the following accompanying drawings in which:

Figure 1 illustrates a schematic representation of the electric assistance system according to an embodiment of the present invention.

Figure 2 illustrates a schematic representation of the electric assistance system according to another embodiment of the present invention.

FIG. 3 illustrates a schematic representation of an electric motor device according to another embodiment of the present invention.

The drawings are given by way of examples and do not limit the invention. They constitute schematic representations of principle intended to facilitate understanding of the invention and are not necessarily scaled to practical applications. In particular the dimensions are not representative of reality.

DETAILED DESCRIPTION

Before starting a detailed review of embodiments of the invention, optional characteristics are set out below which may optionally be used in combination or alternatively.

According to one example, the system comprises at least one control unit, the control unit and the electric motor device being configured to deliver to the camshaft a torque that varies over time, in particular over a time corresponding to a complete rotation of the camshaft, and so that the torque delivered by the camshaft is constant over time, in particular over a time corresponding to a complete rotation of the camshaft.

According to one example, the system comprises at least one first sensor and at least one control unit, the first sensor being configured to detect rotation of the crankshaft and to transmit a start-up signal to the control unit, the the control unit being configured to control the electric motor device, and to start the electric motor device on receipt of the start signal from the first sensor, the starting of the electric motor device driving the motor shaft in rotation around the second axis of rotation.

This makes it possible to start the rotation of the crankshaft at the same time as the rotation of the crankshaft.

This assists the camshaft as soon as it starts rotating.

According to one example, the first sensor is a rotational speed sensor configured to measure the rotational speed of the crankshaft and to transmit the measurement of the rotational speed of the crankshaft to the control unit so that the control unit control drives the motor electrical device.

According to one example, the system comprises at least one torque sensor configured to measure the value of the resistive torque of the camshaft and to transmit this value to the control unit, the control unit then controlling the electric motor device so that it delivers a torque depending on the resistive torque of the camshaft, preferably configured to compensate for the resistive torque of the camshaft.

This keeps the engine torque of the crankshaft constant and reduces the resistive torque of the camshaft. Indeed, in the event of an increase in the resistive torque of the camshaft, the engine electrical device is configured to apply a torque so as to reduce the resistive torque of the camshaft, also it provides a holding torque of the crankshaft engine torque.

According to one example, the system comprises at least one control unit configured to control the electrical motor device, preferably at least the torque of the motor shaft, advantageously from at least one torque curve as a function of a speed of engine operation.

According to one example, the system comprises at least one electrical power source configured to electrically power the motor electrical device, the electrical power source being taken from at least: a battery, a photovoltaic panel, a wind turbine, a distribution network electric.

According to one example, the camshaft is configured to drive at least one other moving element, preferably a vacuum pump.

This makes it possible to electrically assist the other mobile element, such as a vacuum pump, for example.

According to one example, the electric motor device is configured to cooperate with at least one accessory having a mobile element in rotation around a third axis of rotation so that the rotation of the motor shaft around the second axis of rotation causes in rotation the mobile element around the third axis of rotation.

This makes it possible to make the use of the present invention even more profitable.

According to one example, the system comprises at least one additional coupling device configured to mechanically couple the rotation of the engine shaft around the second axis of rotation with the rotation of the camshaft around the first axis of rotation and with the rotation of the mobile element around the third axis of rotation.

According to one example, the coupling device comprises at least one planetary gear train configured to mechanically couple the rotation of the motor shaft around the second axis of rotation with the rotation of the camshaft around the first axis of rotation.

According to one example, the motor electrical device is arranged at the other end of the camshaft.

According to one example, the motor electrical device is arranged on the side of the distribution module relative to the camshaft.

According to one example, the coupling device comprises at least one pinion comprising an outer part and an inner part, the outer part being configured to cooperate with the distribution module and the inner part being configured to cooperate with the camshaft.

According to one example, the electrical motor device is configured to drive the motor shaft in rotation in a single direction of rotation around the second axis of rotation.

According to one example, the camshaft comprises at least one main cam and at least one additional cam.

This makes it possible to electrically assist a plurality of cams.

According to one example, the resistive torque of the camshaft electrically assisted by the electrical motor device is lower than the resistive torque of the camshaft not electrically assisted by the electrical motor device.

1. Détermination du couple résistant de l’arbre à cames ;
2. Pilotage du dispositif électrique moteur pour ajuster le couple résistant de l’arbre à cames.

According to one example, the system includes at least one control unit configured to perform the following steps:

1. Determination of the camshaft resistive torque;
2. Control of the engine electrical device to adjust the resistive torque of the camshaft.

According to one example, the system comprises at least one torque sensor, and the control unit is configured to receive a measurement of the resistive torque of the camshaft from the torque sensor.

1. Détermination du régime de fonctionnement du moteur à combustion ;
2. Détermination du couple résistant de l’arbre à cames à partir de la lecture d’au moins une courbe d’assistance électrique comprenant un enregistrement du couple résistant de l’arbre à cames en fonction du régime de fonctionnement du moteur à combustion.

According to an example, the control unit is configured to perform the following steps:

1. Determination of the operating speed of the combustion engine;
2. Determination of the resistive torque of the camshaft from the reading of at least one electrical assistance curve comprising a recording of the resistive torque of the camshaft as a function of the operating speed of the combustion engine.

1. Recevoir une configuration des cylindres du moteur à combustion depuis au moins un système de désactivation de cylindres ;
2. Sélectionner une courbe d’assistance électrique parmi une pluralité de courbe d’assistance électrique, chaque courbe d’assistance électrique de la pluralité de courbes d’assistance électrique correspondant à au moins une configuration desdits cylindres.

According to an example, the control unit is configured for:

1. receiving a combustion engine cylinder configuration from at least one cylinder deactivation system;
2. Selecting an electric assistance curve from among a plurality of electric assistance curves, each electric assistance curve of the plurality of electric assistance curves corresponding to at least one configuration of said cylinders.

1. Détermination d’une intensité électrique en fonction du couple résistant de l’arbre à cames ;
2. Délivrance de ladite intensité électrique au dispositif électrique moteur par l’unité de contrôle.

According to an example, the control unit is configured to carry out the following steps so as to adjust the resistive torque of the camshaft:

1. Determination of an electrical intensity as a function of the resistive torque of the camshaft;
2. Delivery of said electrical intensity to the motor electrical device by the control unit.

1. Mesure par au moins un capteur de couple du couple résistant de l’arbre à cames;
2. Réception par l’unité de contrôle de la mesure du couple depuis le capteur de couple.

According to one example, the step of determining the resistive torque of the camshaft comprises at least the following steps:

1. Measurement by at least one torque sensor of the resistive torque of the camshaft;
2. Reception by the control unit of the torque measurement from the torque sensor.

1. Détermination du régime de fonctionnement du moteur à combustion ;
2. Détermination du couple résistant de l’arbre à cames à partir de la lecture d’au moins une courbe d’assistance électrique comprenant un enregistrement du couple résistant de l’arbre à cames en fonction du régime de fonctionnement du moteur à combustion.

According to one example, the step of determining the resistive torque of the camshaft comprises at least the following steps:

1. Determination of the operating speed of the combustion engine;
2. Determination of the resistive torque of the camshaft from the reading of at least one electrical assistance curve comprising a recording of the resistive torque of the camshaft as a function of the operating speed of the combustion engine.

1. Réception par l’unité de contrôle d’une configuration des cylindres du moteur à combustion depuis au moins un système de désactivation de cylindres ;
2. Sélection d’une courbe d’assistance électrique parmi une pluralité de courbe d’assistance électrique, chaque courbe d’assistance électrique de la pluralité de courbes d’assistance électrique correspondant à au moins une configuration desdits cylindres.

According to one example, the method comprises, before determining the operating speed of the combustion engine, at least the following steps:

1. receiving by the control unit a configuration of the cylinders of the combustion engine from at least one cylinder deactivation system;
2. Selection of an electric assistance curve from among a plurality of electric assistance curves, each electric assistance curve of the plurality of electric assistance curves corresponding to at least one configuration of said cylinders.

1. La détermination d’une intensité électrique en fonction du couple résistant de l’arbre à cames ;
2. Délivrance de ladite intensité électrique au dispositif électrique moteur par l’unité de contrôle.

According to one example, the step of controlling the engine electrical device by the control unit to adjust the resistive torque of the camshaft comprises at least the following steps:

1. The determination of an electrical intensity as a function of the resistive torque of the camshaft;
2. Delivery of said electrical intensity to the motor electrical device by the control unit.

According to one example, the system according to the present invention is configured to allow the implementation of the method previously described.

The present invention relates to the electrical assistance of a camshaft. The aim of the present invention is to reduce part of the mechanical losses inherent in a combustion engine, that is to say to reduce the resistive torque of the camshaft of a combustion engine. In fact, when the valves move, for example, friction appears, thus reducing the efficiency of the engine. The present invention compensates at least in part, preferably entirely, for these mechanical losses by assisting the camshaft in its rotation, preferably by an electric motor device. Such a motor electrical device is mainly defined by its torque. In fact, advantageously, and as described below, the motor electrical device is configured to be advantageously controlled in torque so as to provide the necessary torque to the camshaft to compensate for all or part of these mechanical losses.

Advantageously, the compensation for these losses extends beyond the camshaft and concerns all the mechanical elements driven by the camshaft.

Advantageously, the electric motor device is a geared motor.

According to one embodiment, this geared motor can be fixed directly to the end of the camshaft, that is to say to one of its ends.

According to another preferred embodiment, the gearmotor can be mechanically coupled with the camshaft through a coupling device.

Preferably, the geared motor operates in continuous and permanent rotation as soon as the crankshaft is rotating. It thus assists the camshaft and enables it to overcome, for example, the forces linked to the shape of the cams and/or to the compression of the valve springs and/or the forces linked to the various frictions of the mechanical parts involved in the rotation of the camshaft and/or driven by the rotation of the camshaft.

According to one embodiment, the geared motor operates with a coupling device configured to multiply its torque in order to deliver a certain torque while limiting its own electrical consumption.

Preferably, the electric motor device, also called a geared motor, can be powered directly by the battery of the motor to be assisted, for example in the case of a vehicle, or even by another electrical source, such as for example photovoltaic panels or even by an electrical energy distribution network in the case of non-moving motor assistance.

Advantageously, the electrical supply of the motor electrical device by the electric battery of a vehicle, for example, has the advantage of starting the present invention as soon as the engine of the vehicle is started, and throughout its use.

According to one embodiment, the electrical motor device can be electrically powered by any type of electrical energy source, such as for example by photovoltaic panels arranged on the roof of a vehicle equipped with the present invention.

Advantageously, the present invention complements existing technical devices such as disengageable valves, cylinder deactivation systems, camshaft angle variation devices and does not call their use into question. Thus the conventional drive device of the camshaft is not impacted for example by the present invention.

In a clever way, the engine electrical device is coupled to the camshaft at one of its ends. According to one embodiment, the motor electrical device is mechanically coupled with the camshaft at the end of the camshaft opposite the distribution module, that is to say, for example, at the end opposite the timing belt.

According to another embodiment, the motor electrical device can be mechanically coupled with the camshaft at the end of the camshaft where the distribution module is located. For example, in this configuration, the coupling device may comprise a camshaft drive pinion comprising an outer part configured for driving the camshaft by the timing module and an inner part configured for drive of the camshaft by the electrical engine device.

According to one embodiment, the present invention also makes it possible to directly and/or indirectly assist engine accessories, such as for example vacuum pumps. In a clever way, the electrical motor device can be coupled to the camshaft and to one or more accessories via, for example, an additional coupling device. For example, the geared motor can be mechanically coupled to the actuating mechanism of a vacuum pump through an epicyclic gear train. This planetary gear train can then be arranged between the camshaft and the power-assisted accessory.

1. Deux arbres coaxiaux dits planétaires, l’un intérieur et l’autre extérieur ;
2. Des satellites s'engrenant avec les 2 planétaires, et tournant autour de leur axe commun ;
3. Un porte satellites ;
4. Un bâti.

Preferably, the planetary gear train comprises a plurality of gears including at least the following elements:

1. Two coaxial so-called planetary shafts, one inside and the other outside;
2. Satellites meshing with the 2 planetary gears, and rotating around their common axis;
3. A satellite carrier;
4. A frame.

Thus the present invention relates to an electric assistance system for an engine comprising at least one camshaft movable in rotation about a first axis of rotation, at least one crankshaft movable in rotation about a main axis of rotation and at least a distribution module disposed at one of the ends of the camshaft and configured to allow the crankshaft movable in rotation around the main axis of rotation to drive said camshaft in rotation around said first axis of rotation.

1. Un dispositif électrique moteur comprenant au moins un arbre moteur mobile en rotation autour d’un deuxième axe de rotation, le dispositif électrique moteur étant configuré pour coopérer avec ledit arbre à cames de sorte à ce que la rotation de l’arbre moteur autour du deuxième axe de rotation entraîne en rotation l’arbre à cames autour du premier axe de rotation, de préférence simultanément à l’entraînement en rotation de l’arbre à cames autour du premier axe de rotation par le vilebrequin;
2. Un dispositif de couplage mécanique configuré pour coupler mécaniquement la rotation de l’arbre moteur autour du deuxième axe de rotation avec la rotation de l’arbre à cames autour du premier axe de rotation ; De préférence, ce dispositif de couplage peut permettre d’entraîner en rotation des accessoires, ou autres éléments mobiles;
3. De préférence, une source d’alimentation électrique configurée pour alimenter électriquement le dispositif électrique moteur.

L’arbre moteur est avantageusement configuré pour être continûment mobile en rotation autour du deuxième axe de rotation en même temps que le vilebrequin est mobile en rotation autour de l’axe de rotation principal.Cleverly, according to a preferred embodiment of the present invention, the system comprising at least:

1. An electric motor device comprising at least one motor shaft movable in rotation around a second axis of rotation, the electric motor device being configured to cooperate with said camshaft so that the rotation of the motor shaft around the second axis of rotation rotates the camshaft around the first axis of rotation, preferably simultaneously with the rotational drive of the camshaft around the first axis of rotation by the crankshaft;
2. A mechanical coupling device configured to mechanically couple the rotation of the engine shaft around the second axis of rotation with the rotation of the camshaft around the first axis of rotation; Preferably, this coupling device can make it possible to rotate accessories, or other moving elements;
3. Preferably, an electrical power source configured to electrically power the motor electrical device.

The motor shaft is advantageously configured to be continuously rotatable around the second axis of rotation at the same time as the crankshaft is rotatable around the main axis of rotation.

Cleverly, the assistance is delivered in a uniform way, whatever the engine speed.

We will now describe the present invention through several embodiments compatible with each other.

According to one embodiment, the combustion engine may not include a cylinder deactivation system. A cylinder deactivation system makes it possible to reduce consumption, by deactivating part of the cylinders of an engine under certain conditions: low speed and reduced torque demand. To operate this cut, the camshaft can for example have two cam profiles for the second and third cylinders for example. A first classic profile, therefore ovoid, allows the cylinders to operate. While the second profile, round, leaves the valves closed, and therefore the cylinders at rest. The transition from one state to another takes place by a lateral sliding of the cams controlled by the on-board computer, which then cuts the injection into these cylinders.

This type of system is not found on all combustion engines. In particular, when the combustion engine does not have one, the present invention proposes a particular embodiment.

On engines without a cylinder deactivation system, the camshaft resistive torque is linked to the engine speed, preferably only linked to the engine speed. The present invention therefore proposes to carry out a phase of simultaneous recording of the different engine speeds and the values of the resistive torque of the camshaft associated with these different speeds, and this in the laboratory or in the factory for example. This recording makes it possible to define a so-called electric assistance curve, this electric assistance curve is then integrated into a control unit in order to allow the control unit to control the electric motor device, preferably to adjust the torque of the engine electrical device according to the engine speed. Thus, from this recording which includes the value of the resistive torque of the camshaft for each engine speed, it is possible to establish which parameters for controlling the engine electrical device are the best according to the degree of assistance that desired to the camshaft and depending on the various operating speeds of the combustion engine. It will be noted that the present invention makes it possible to configure the desired degree of assistance. Indeed, it is possible, for example without limitation, to compensate for the mechanical losses by half, see entirely or for example up to 90%, degrees of assistance can be chosen by the user and/or the control unit.

According to one embodiment, the torque sensor can be used only in the factory or in the laboratory for capturing data during the generation of the electric assistance curve(s). Thus, preferably, the torque sensor is not necessary once the assistance curve has been carried out, it suffices to know the speed in which the engine is located and to apply the parameters saved according to the assistance curve. electric. According to this embodiment, the system, once installed on an engine, does not require a camshaft resistive torque sensor.

This embodiment allows the adaptation of the present invention to combustion engines without a cylinder deactivation system and at a reduced cost since the torque sensor is not necessary and the control electronics of the electric motor device is little complex.

It will be recalled here that the engine speed of a combustion engine can be determined and/or measured. For example, measuring the rotational speed of the crankshaft makes it possible to determine the engine speed. For example, a sensor on the flywheel can also be used for this purpose.

According to another embodiment, the combustion engine may include a cylinder deactivation system. In this case, an economical solution is also provided by the present invention. Indeed, in the case of such a combustion engine, it will present a plurality of activated/deactivated cylinder configurations. Also, the present invention proposes a recording phase of a plurality of electric assistance curves. Indeed, for each possible configuration, a curve of the camshaft resistive torque as a function of the engine speeds is generated, as previously indicated. This then makes it possible to obtain a plurality of curves all linked to a precise configuration of the cylinders. Also, the measurement of the camshaft resistive torque is no longer necessary once these curves have been carried out. It is enough to know the engine speed and the configuration of the cylinders to choose the right curve and deliver the right electric assistance, the configuration of the cylinders being able to be communicated by the cylinder deactivation system to the control unit of the engine electrical device. It will be noted that the deactivation of a cylinder leads to the deactivation of at least two valves, thus causing a reduction in the resistive torque of the camshaft.

Advantageously, this embodiment can be applied to engines equipped with pump injectors which can generate some variations in torque on the camshaft. It suffices to measure in the laboratory or in the factory all of the engine configurations influencing the resistive torque of the camshaft so as to generate an electric assistance curve for each possible configuration.

According to another embodiment, when the combustion engine does not vary in speed, the resistive torque of the camshaft can be constant. Therefore, the present invention is configured so that the motor electrical device delivers a constant torque equal to the torque of the motor shaft. This constant torque can either be determined in the laboratory or in the factory, or directly measured in real time. Factory measurement is less expensive and simpler. It is therefore sufficient to configure the motor electrical device so that it delivers the corresponding torque. This torque being fixed, it is not necessary to adjust it. According to this embodiment, it is possible to dispense with a torque sensor once the assistance system has been calibrated for the first time, in the factory for example.

This embodiment applies in particular to engines which therefore do not exhibit speed variability, such as generators for example. Indeed, it is possible to simplify the system and thus dispense with integrating a torque curve, or even a torque sensor. The control unit therefore plays the role of a simple relay controlled by the crankshaft rotation sensor which will be activated at nominal speed unless you want the geared motor to accompany the starter in the launch phase, for example.

According to another embodiment, the present invention comprises a torque sensor configured to measure the resistive torque of the camshaft and adjust in real time the torque delivered by the motor electrical device. According to this embodiment, which can also be applied to the previous embodiments, the real-time measurement of the resistive torque of the camshaft allows real-time adjustment regardless of the speed or the presence or not of a cylinder deactivation system. This embodiment also makes it possible to dispense with a phase of recording electrical assistance curves as presented above, and therefore a phase of calibration in the factory or in the laboratory.

We will now describe the present invention through Figures 1 and 2 illustrating two embodiments of the present invention by way of non-limiting examples.

Figure 1 illustrates a sectional view of an engine 10 comprising a crankshaft 1 rotatable about a main axis of rotation 1a. The crankshaft 1 is rotated through the movement of the pistons 1b. The crankshaft 1 comprises at one of its ends a drive wheel 1c. The crankshaft 1 is mechanically coupled to a distribution module 2 at its other end.

This timing module 2 comprises for example a timing belt 2a mechanically coupling the rotation of the crankshaft 1 with the rotation of the camshaft 3. More precisely, this coupling allows the rotational drive of the camshaft 3 around of the first axis of rotation 3a by the rotation of the crankshaft 1 around the main axis of rotation 1a.

The camshaft 3 is configured to drive a plurality of valves 3b. Indeed, the camshaft 3 is configured to convert its rotational movement around the first axis of rotation into an alternating translational movement of the valves 3b.

The camshaft 3 is mechanically coupled to the electric motor device 4, preferably via a coupling device 5. This coupling device 5 can comprise a plurality of gears and sprockets.

The electrical motor device 4 comprises a motor shaft 4b rotatable around a second axis of rotation 4a.

The first axis of rotation 3a is preferably parallel to the main axis of rotation 1. Preferably, the second axis of rotation 4a is parallel to the first axis of rotation 3a.

In this figure, we note the presence of a control unit 9 configured to control the electric motor device 4. In particular, the control unit 9 is configured to control the starting and stopping of the electric motor device 4. Preferably, the control unit 9 is configured to control the torque of the motor shaft 4b of the electric motor device 4. This control can be either constant or produced from one or more electric assistance curves such as as previously presented and/or from the measurement by a torque sensor 7 of the resistive torque of the camshaft 3, preferably in real time.

There is also a sensor 6, preferably a rotation speed sensor. This sensor 6 is configured to detect the rotation of the crankshaft 1, and to transmit a first signal to the control unit as soon as the crankshaft 1 is rotating and to transmit a second signal to the control unit as soon as crankshaft 1 stops rotating. The control unit 9 is configured to start the electric motor device 4 upon receipt of said first signal. The control unit 9 is configured to stop the electrical motor device 4 upon receipt of said second signal.

According to one embodiment, the rotational speed sensor 6 is configured to measure the rotational speed and transmit said measurement to the control unit 9. Upon receipt of said rotational speed measurement of the crankshaft 1, the control unit control adjusts the torque of the electric motor device 4. Indeed, in a clever way, this speed measurement makes it possible to deduce the current operating speed of the combustion engine 10.

In this figure, and according to one embodiment, the presence of a torque sensor 7 is noted. This torque sensor 7 is configured to measure the mechanical torque of the camshaft 3. This torque sensor 7 is configured to transmit to the control unit 9 said measurement of the torque. Upon receipt of this measurement, the control unit 9 is configured to adjust the operating parameters of the electric motor device 4, preferably the electric current supplied to the electric motor device 4, so that the torque of the shaft motor 4b compensates for the resistive torque of the measured camshaft 3. Preferably, the control unit 9 adjusts the mechanical torque delivered by the electric motor device 4 so that the resistive torque of the measured camshaft 3 tends towards zero. This makes it possible to reduce the resistive torque of the camshaft while maintaining a minimum mechanical tension applied to the timing belt 2a.

In a clever way, this makes it possible to combat the mechanical losses previously presented. Indeed, by allowing the camshaft 3 to reduce its resistive torque, this makes it possible to reduce the mechanical losses.

For example, while the camshaft 3 is rotating and has a first resistive torque, the electric motor device 4 delivers a second torque to the motor shaft 3. As soon as the torque sensor 7 measures a resistive torque of the camshaft 3 greater than a predetermined value for example, the present invention ensures the reduction of the resistive torque of the camshaft 3 due to friction for example, and the maintenance of the torque of the crankshaft 1 by ensuring the maintenance of the torque from drive shaft 4b so as to compensate for the loss of resistive torque from camshaft 3. The torque from drive shaft 4b is then transmitted to camshaft 3.

In a particularly clever way, the present invention makes it possible to reduce the mechanical losses while having a reduced energy consumption, even autonomous.

The present invention thus makes it possible to reduce the resistive torque of the camshaft 3 and therefore to increase the engine torque of the crankshaft 1.

We also note in Figure 1 the presence of a cylinder deactivation system 12 as presented previously according to one embodiment. This system has the function of deactivating one or more cylinders according to various operating parameters of the engine 10. The cylinder deactivation system 12 is, according to one embodiment, in communication with the control unit 9. According to this mode embodiment, the central unit 9 uses the information transmitted by the cylinder deactivation system 12 to control the electric motor device 4, preferably to adjust the torque delivered by the electric motor device 4. According to this embodiment, and when a generation phase of a plurality of electric assistance curves has been carried out in the factory or in the laboratory for example, it is not necessary to have the torque sensor 7 since the control unit 9 determines the engine speed and receives the configuration of the activated and deactivated cylinders via the cylinder deactivation system 12, therefore, from the electrical assistance curves previously generated, the u control unit 9 can adjust the torque delivered by the electric motor device 4.

Figure 2 illustrates an example of implementation of the present invention in which the electric motor device 4 assists the camshaft 3 and also any accessory 11 having a moving part around a third axis of rotation 11a. In this example, the electric motor device 4 rotates a mobile element around a third axis of rotation 11a via an additional coupling device 5a.

FIG. 3 represents a sectional and schematic view of an electric motor device 4 of the geared motor type mechanically coupled with a reduction gear, also called planetary gear train 5b. This figure also shows the engine shaft 4b and a portion of the camshaft 3.

The present invention makes it possible in a simple and reliable manner to reduce the consumption of a combustion engine.

The present invention in fact makes it possible to compensate for part of the mechanical losses inherent in an operating motor.

Particularly advantageously, in the particular case of generating sets used in island electrical systems, the contribution of maintaining the charge of the battery of the set by photovoltaic panels or wind turbines makes the present invention totally efficient with respect to the drop in fuel consumption and therefore polluting emissions and carbon dioxide. This also applies to any type of combustion engine such as those used on vehicles such as boats, trains, buses, and more generally any machine having a substantial and unused surface which may therefore include a plurality of panels photovoltaic. Cleverly, the contribution by solar energy compensates for the electrical consumption of the present invention.

Finally, it will be noted that the present invention is suitable for any type of combustion engine comprising one or more camshafts.

The invention is not limited to the embodiments previously described and extends to all the embodiments covered by the claims.
List of references
1 Crankshaft
1a Main axis of rotation
1b Plungers
1c Drive wheel
2 Distribution module
2a Timing belt
3 Camshaft
3a First axis of rotation
3b Valves
4 Motor electrical device
4a Second axis of rotation
4b Motor shaft
5 Coupling device
5a Additional coupling device
5b Planetary gear train
6 Speed sensor
7 Torque sensor
8 Power source
9 Control unit
10 Combustion engine
11 Accessory
11a Third axis of rotation
12 Cylinder deactivation system

Claims (28)

Electric assistance system for an engine (10), preferably a combustion engine, the engine (10) comprising at least one camshaft (3) rotatable around a first axis of rotation (3a), at least one crankshaft (1) rotatable about a main axis of rotation (1a) and at least one distribution module (2), preferably arranged at one of the ends of the camshaft (3), and configured to allowing the crankshaft (1) to drive said camshaft (3) in rotation around said first axis of rotation (3a), said system comprising at least:

1. An electrical motor device (4) comprising at least one motor shaft (4b) movable in rotation about a second axis of rotation (4a), the system being configured so that the electrical motor device (4) cooperates with said camshaft (3) so that the rotation of the motor shaft (4b) around the second axis of rotation (4a) causes the camshaft (3) to rotate around the first axis of rotation (3a), preferably simultaneously with the rotational drive of the camshaft (3) around the first axis of rotation (3a) by the crankshaft (1), the electric motor device (4) being intended to be powered by at least one power source power supply (8);
2. A mechanical coupling device (5) configured to ensure said cooperation between the engine electrical device (4) and the camshaft (3);

The engine shaft (4b) being configured to be continuously mobile in rotation around the second axis of rotation (4a), preferably in a single direction of rotation, when the crankshaft (1) is mobile in rotation around the axis of main rotation (1a). System according to the preceding claim comprising at least one control unit (9), the control unit (9) and the electric motor device (4) being configured to deliver to the camshaft (3) a variable torque in the time, in particular over a time corresponding to a complete rotation of the camshaft (3), and so that the torque delivered by the camshaft (3) is constant over time, in particular over a time corresponding to a full rotation of the camshaft (3). System according to claim 1 comprising at least one first sensor (6) and at least one control unit (9), the first sensor (6) being configured to detect rotation of the crankshaft (1) and to transmit a switching on to the control unit (9), the control unit (9) being configured to control the electric motor device (4), and to start the electric motor device (4) on receipt of the signal from switching on from the first sensor (6), the switching on of the electric motor device (4) driving the motor shaft (4b) in rotation around the second axis of rotation (4a). System according to the preceding claim, in which the first sensor (6) is a rotational speed sensor configured to measure the rotational speed of the crankshaft (1) and to transmit the measurement of the rotational speed of the crankshaft (1) to the control unit (9) so that the control unit (9) controls the electrical motor device (4) System according to any one of the two preceding claims, comprising at least one torque sensor (7) configured to measure the value of the resistive torque of the camshaft (3) and to transmit this value to the control unit (9 ), the control unit (9) then controlling the motor electrical device (4) so that it delivers a torque which is a function of the resistive torque of the camshaft (3), preferably configured to compensate for the torque camshaft resistor (3). System according to any one of the preceding claims comprising at least one control unit (9) configured to control the electric motor device (4), preferably at least the torque of the motor shaft (4b), advantageously from at least a torque curve as a function of an operating speed of the engine (10). System according to any one of the preceding claims, comprising at least one electrical power source (8) configured to electrically power the motor electrical device (4), the electrical power source (8) being taken from at least: a battery , a photovoltaic panel, a wind turbine, an electrical distribution network. System according to any one of the preceding claims, in which the camshaft (3) is configured to drive at least one other movable element, preferably a vacuum pump. System according to any one of the preceding claims, in which the electric motor device (4) is configured to cooperate with at least one accessory (11) having an element that can rotate around a third axis of rotation (11a) so as to that the rotation of the motor shaft (4b) around the second axis of rotation (4a) causes the mobile element to rotate around the third axis of rotation (11a). System according to the preceding claim comprising at least one additional coupling device (5a) configured to mechanically couple the rotation of the engine shaft (4b) around the second axis of rotation (4a) with the rotation of the camshaft (3 ) around the first axis of rotation (3a) and with the rotation of the movable element around the third axis of rotation (11a). System according to any one of the preceding claims, in which the coupling device (5) comprises at least one epicyclic gear train (5b) configured to mechanically couple the rotation of the motor shaft (4b) around the second axis of rotation (4a) with the rotation of the camshaft (3) around the first axis of rotation (3a). System according to any one of the preceding claims, in which the motor electrical device (4) is arranged at the other end of the camshaft (3). System according to any one of Claims 1 to 11, in which the electrical motor device (4) is arranged on the side of the distribution module (2) relative to the camshaft (3). System according to any one of the preceding claims, in which the electrical motor device (4) is configured to drive the motor shaft (4b) in rotation in a single direction of rotation around the second axis of rotation (4a). System according to any one of the preceding claims, in which the camshaft (3) comprises at least one main cam and at least one additional cam. System according to any one of the preceding claims, in which the resistive torque of the camshaft (3) electrically assisted by the electric motor device (4) is lower than the resistive torque of the non-electrically assisted camshaft (3). by the motor electrical device (4). System according to any of the preceding claims comprising a control unit (9) configured to carry out the following steps:

1. Determination of the resistive torque of the camshaft (3);
2. Control of the motor electrical device (4) to adjust the resistive torque of the camshaft (3).

System according to the preceding claim comprising at least one torque sensor (7), and in which the control unit (9) is configured to receive a measurement of the resistive torque of the camshaft (3) from the torque sensor ( 7). System according to claim 17 wherein the control unit (9) is configured to perform the following steps:

1. Determination of the operating speed of the combustion engine (10);
2. Determination of the resistive torque of the camshaft (3) from the reading of at least one electrical assistance curve comprising a recording of the resistive torque of the camshaft (3) as a function of the operating speed of the combustion engine (10).

System according to the preceding claim, in which the control unit (9) is configured for:

1. receiving a cylinder configuration of the combustion engine (10) from at least one cylinder deactivation system (12);
2. Selecting an electric assistance curve from among a plurality of electric assistance curves, each electric assistance curve of the plurality of electric assistance curves corresponding to at least one configuration of said cylinders.

System according to any one of the four preceding claims, in which the control unit (9) is configured to carry out the following steps so as to adjust the resistive torque of the camshaft (3):

1. Determination of an electrical intensity as a function of the resistive torque of the camshaft (3);
2. Delivery of said electric current to the motor electric device (4) by the control unit (9).

A combustion engine assembly (10) comprising a combustion engine (10) and said combustion engine power assist system (10) according to any preceding claim. Motorized vehicle comprising at least one assembly according to the preceding claim. Method for adjusting the resistive torque of at least one camshaft (3) of a combustion engine (10) by an electric assistance system according to any one of Claims 1 to 21, the method comprising at least the following steps:

1. Determination of the resistive torque of the camshaft (3);
2. Control of the motor electrical device (4) by at least one control unit (9) to adjust the resistive torque of the camshaft (3).

Method according to the preceding claim, in which the step of determining the resistive torque of the camshaft (3) comprises at least the following steps:

1. Measurement by at least one torque sensor (7) of the resistive torque of the camshaft (3);
2. Reception by the control unit (9) of the measurement of the torque from the torque sensor (7).

Method according to Claim 24, in which the step of determining the resistive torque of the camshaft (3) comprises at least the following steps:

1. Determination of the operating speed of the combustion engine (10);
2. Determination of the resistive torque of the camshaft (3) from the reading of at least one electrical assistance curve comprising a recording of the resistive torque of the camshaft (3) as a function of the operating speed of the combustion engine (10).

Method according to the preceding claim comprising, before determining the operating speed of the combustion engine (10), at least the following steps:

1. Receiving by the control unit a configuration of the cylinders of the combustion engine (10) from at least one cylinder deactivation system (12);
2. Selection of an electric assistance curve from among a plurality of electric assistance curves, each electric assistance curve of the plurality of electric assistance curves corresponding to at least one configuration of said cylinders.

Method according to any one of the four preceding claims, in which the step of controlling the electric motor device (4) by the control unit (9) to adjust the resistive torque of the camshaft (3) comprises at least the following steps:

1. Determining an electrical intensity as a function of the resistive torque of the camshaft (3);
2. Delivery of said electric current to the motor electric device (4) by the control unit (9).