EP2669470B1 - Internal combustion engine - Google Patents

Description

TECHNICAL AREA

The present invention relates to the general technical field of motors, and in particular of internal combustion engines (or " combustion engines "), transforming the thermal energy obtained by combustion, within the engine itself, of a fluid mechanical energy usable for example to propel vehicles (such as automobiles, motorcycles, aircraft or boats), to animate machines (industrial or agricultural), or to provide mechanical energy to devices energy conversion, like generators.

The invention more specifically relates to an internal combustion engine comprising on the one hand a chamber designed to receive a working fluid intended to undergo combustion within said chamber and on the other hand a first piston which contributes to delimiting the volume of said chamber.

PRIOR ART

Internal combustion engines, usually referred to as " spark-ignition engines ", have been known for a long time and are widely used, since they equip the vast majority of motor vehicles, just to mention this type of motorized equipment.

The most common internal combustion engines are " four-stroke " engines, which use a thermodynamic cycle corresponding substantially to the theoretical thermodynamic cycle called "de Beau de Rochas", well known in the field.

The architecture of these known four-stroke engines is generally based on the implementation of a cylinder which is closed in its upper part by a cylinder head.

The cylinder and the cylinder head form a combustion chamber whose volume is regulated by the stroke of a piston sliding in the cylinder in a reciprocating movement imparted by the pressure variations resulting from the combustion cycles operated in the chamber. of combustion. The piston is itself connected to a crankshaft, via a connecting rod, to transform the rectilinear translation movement of the piston into rotational movement of the crankshaft. The cylinder head is intended to accommodate intake and exhaust valves which respectively allow the admission of the combustible fluid (air-fuel gas mixture) into the chamber and the evacuation out of the flue gas chamber resulting from the rapid combustion. (deflagration) of said fluid. The movement of the valves relative to the cylinder head is controlled synchronously by one or more camshafts driven by the crankshaft, for example by means of a chain or gear system.

This known engine architecture generally gives satisfaction, but has no less serious disadvantages.

First, the presence of a cylinder head reported on the cylinder is likely to cause reliability problems, particularly at the cylinder head gasket interposed between the cylinder and the cylinder head. The implementation of a cylinder head and the corresponding seal also necessarily limits the compression ratio of the engine, since a rate of high or very high compression would of course be likely to cause deterioration of the head gasket. In addition, these known motors use a relatively heavy and complex mechanical and kinematic chain of force transfer between the crankshaft, the camshaft (which is generally deported) and the valves. This is, of course, a potential source of failure and loss of energy efficiency, and is not intended to increase reliability or reduce cost.

In general, these known motors use a large number of moving parts, which corresponds to a large moving mass, again likely to cause problems of efficiency and reliability. Furthermore, the architecture of these known engines is relatively restrictive from the point of view of the intake and exhaust sections, which are limited to relatively low values because of the implantation constraints of the valves in the cylinder head. Finally, these known engines also prove to be relatively heavy and bulky, so that their location within a vehicle, and particularly within a car-type vehicle can be problematic.

SUMMARY OF THE INVENTION

The invention therefore aims to remedy the various disadvantages listed above and to propose a new engine whose architecture is particularly simple, efficient and reliable.

Another object of the invention is to propose a new motor which implements a minimum number of moving parts, which is particularly reliable and has a small footprint, especially in height and width.

Another object of the invention is to propose a new engine implementing a mechanical connection between the pistons and the output shaft which, while being particularly simple, efficient and reliable, also makes it possible to adjust performance easily and quickly. of the motor.

Another object of the invention is to propose a new motor implementing a minimum moving mass and likely to provide important intake and / or exhaust sections.

Another object of the invention is to propose a new engine that is particularly compact and that avoids the use of force references and remote transmission parts.

Another object of the invention is to propose a new engine capable of operating the intake and exhaust particularly effectively. Another object of the invention is to propose a new engine that implements a minimum of different parts.

The objects assigned to the invention are achieved by means of an internal combustion engine according to claim 1

SUMMARY DESCRIPTION OF THE DRAWINGS

• La figure 1 illustre, selon une vue de côté en coupe partielle, un exemple de moteur à quatre temps conforme à l'invention.
• La figure 2 illustre, selon une autre vue de côté en coupe partielle, le moteur de la figure 1.
• La figure 3 illustre, selon une vue de côté en coupe, le moteur des figures 1 et 2 lors de la mise en oeuvre du premier temps (admission).
• La figure 4 illustre, selon une vue de côté en coupe, le moteur des figures précédentes lors de la fin du premier temps.
• La figure 5 illustre, selon une vue de côté en coupe, le moteur des figures précédentes lors de la mise en oeuvre du deuxième temps (compression).
• La figure 6 illustre, selon une vue de côté en coupe, le moteur des figures précédentes lors de la mise en oeuvre d'une première phase (explosion) du troisième temps.
• La figure 7 illustre, selon une vue de côté en coupe, le moteur des figures précédentes lors de la mise en oeuvre d'une deuxième phase (détente) du troisième temps.
• La figure 8 illustre, selon une vue de côté en coupe, le moteur des figures précédentes lors de la fin de la détente, lorsque les pistons se trouvent dans une position dite de « point mort bas ».
• La figure 9 illustre, selon une vue de côté en coupe, le moteur des figures précédentes lors du début du quatrième temps (échappement).
• La figure 10 illustre, selon une vue de côté en coupe, le moteur des figures précédentes lors de la fin de l'échappement.
• La figure 11 illustre, selon une vue de côté en coupe, la liaison mécanique entre l'arbre de sortie et un piston dans le moteur des figures précédentes.
• La figure 12 illustre, selon une vue en perspective, un détail de l'arbre de sortie du moteur des figures précédentes.
• Les figures 13 et 14 illustrent, selon des vues en perspective, un détail de réalisation d'un piston mis en oeuvre dans le moteur des figures précédentes.
• La figure 15 illustre, selon une vue en perspective, une soupape mise en oeuvre dans le moteur des figures précédentes et destinée à être montée sur le piston des figures 13 et 14.
• La figure 16 illustre, selon une vue en perspective, un sous-ensemble unitaire résultant du montage de la soupape de la figure 15 sur les pistons des figures 13 et 14.

Other objects and advantages of the invention will appear in more detail on reading the description which follows, with reference to the appended drawings, given purely by way of non-limiting illustration, in which:

• The figure 1 illustrates, in a partial sectional side view, an example of a four-stroke engine according to the invention.
• The figure 2 illustrates, according to another side view in partial section, the engine of the figure 1 .
• The figure 3 illustrates, in a sectional side view, the engine of the Figures 1 and 2 during the implementation of the first time (admission).
• The figure 4 illustrates, in a sectional side view, the engine of the preceding figures at the end of the first time.
• The figure 5 illustrates, in a sectional side view, the engine of the preceding figures during the implementation of the second time (compression).
• The figure 6 illustrates, in a sectional side view, the engine of the preceding figures during the implementation of a first phase (explosion) of the third time.
• The figure 7 illustrates, in a sectional side view, the engine of the preceding figures during the implementation of a second phase (expansion) of the third time.
• The figure 8 illustrates, in a sectional side view, the engine of the preceding figures at the end of the relaxation, when the pistons are in a position called " bottom dead center ".
• The figure 9 illustrates, in a sectional side view, the engine of the preceding figures at the beginning of the fourth time (exhaust).
• The figure 10 illustrates, in a sectional side view, the engine of the preceding figures at the end of the exhaust.
• The figure 11 illustrates, in a sectional side view, the mechanical connection between the output shaft and a piston in the motor of the preceding figures.
• The figure 12 illustrates, in a perspective view, a detail of the motor output shaft of the preceding figures.
• The Figures 13 and 14 illustrate, in perspective views, a detail of embodiment of a piston implemented in the motor of the preceding figures.
• The figure 15 illustrates, in a perspective view, a valve implemented in the motor of the preceding figures and intended to be mounted on the piston of the Figures 13 and 14 .
• The figure 16 illustrates, in a perspective view, a unitary subassembly resulting from the mounting of the valve of the figure 15 on the pistons of the Figures 13 and 14 .

BEST MODE OF REALIZING THE INVENTION

The invention relates to an engine, that is to say a device capable of providing a mechanical work usable in particular for propelling a vehicle, and for example a motor vehicle, a motorcycle, an aircraft or a boat, or for operating a machine (machine tool, public works machine, agricultural machine, pump, compressor) or an energy conversion device, such as a generator. The engine 1 according to the invention is an internal combustion engine ("internal combustion engine "), that is to say a motor capable of producing mechanical energy from the combustion within it of a working fluid containing a fuel, and for example a hydrocarbon-based fuel such as gasoline. In a manner known per se, the engine 1 according to the invention comprises a chamber 3, forming a combustion chamber, and designed for this purpose to accommodate a working fluid intended to undergo combustion within said chamber 3. The fluid of Work is therefore a combustible fluid and it is preferably formed of a gas consisting of a mixture of air and vaporized fuel. This gas is intended to undergo rapid combustion, and more precisely an explosion (or even more precisely a deflagration), within the chamber 3. As envisaged in the foregoing, the fuel may be constituted by a petroleum derivative, it being understood that the invention is absolutely not limited to a specific working fluid. In order to produce the chamber 3, the motor 1 preferably comprises a cylinder 2, which is for example, as illustrated in the figures, in the form of a hollow tube, advantageously rectilinear, of longitudinal axis X-X extension . Advantageously, as illustrated in the figures, the cylinder 2 has a substantially circular section. It is however quite possible that the cylinder 2 has a non-circular section, and for example a polygonal section, without departing from the scope of the invention. The inner wall 20 of the cylinder 2 contributes to defining, in the embodiment illustrated in the figures, the chamber 3. In order to overcome the thermal and mechanical stresses resulting from the combustion of the working fluid within the chamber 3, the cylinder 2 is preferably made of a material having a high mechanical and thermal strength, such as a metal material of the cast iron or aluminum alloy type.

The engine 1 according to the invention further comprises at least a first piston 4 which contributes to defining the volume of the chamber 3. In the example illustrated in the figures, the first piston 4 is designed to slide in the cylinder 2 according to a reciprocating (i.e., reciprocating) under the effect of the pressure variation within the chamber 3, said pressure variation being generated, as is well known as such, by the combustion cycles of the working fluid within the chamber 3. Thus, the first piston 4 is threaded inside the cylinder 2 and is tightly fitted against the inner wall 20 of the cylinder 2, so as to be able to slide in the cylinder 2 according to the axis X-X ', while remaining permanently in sealing contact with the inner wall 20 of said cylinder 2. The realization of the sealing contact between the first piston 4 and the inner wall 20 of the cylinder 2 can be achieved by any known means those skilled in the art, by taking and adapting for example the well known and proven technical solutions implemented in the prior art. The first piston 4 advantageously has a head 4A which contributes to defining the chamber 3. The head 4A preferably has a cross section which is complementary to the internal cross section of the cylinder 2, this section preferably being a circular section as in the examples illustrated in the figures. The first piston 4 further comprises a skirt 4B which extends from and to the periphery of the head 4A. Advantageously, the first piston 4 has a longitudinal axis of extension Y-Y ', which corresponds to the axis of symmetry of the cross section of the head 4A of said piston. The longitudinal axis YY 'of the first piston 4 is advantageously merged with the extension axis XX' of the cylinder 2 when the first piston 4 is installed in a functional position inside the cylinder 2, as illustrated in FIGS. Figures 1 to 10 . According to the preferred embodiment illustrated in the figures, the first piston 4 is designed to slide in the cylinder 2 in a pure axial translation movement, that is to say that said first piston 4 is guided relative to the cylinder 2 to to be able to move in longitudinal translation, parallel to the axis X-X ', without rotation of the first piston 4 on itself. In other words, the first piston 4 is in this case mechanically linked to the cylinder 2 by a slide connection. Such axial guidance of the first piston 4 in pure translation in the cylinder 2 limits not only the problems of vibration and premature wear of the piston against the jacket encountered in the engines of the prior art, but also the problems of loss. of efforts encountered in these same engines. These problems come essentially from the fact that in art previous, the pistons are not directly guided in the cylinder, but are indirectly by the linkage which works off-axis during the movements of the piston under load. There are of course a multitude of technical possibilities, well known to those skilled in the art, for making such a sliding connection between the first piston 4 and the cylinder 2. In the embodiment illustrated in the figures, this slide connection, which allows the first piston 4 to slide in the cylinder 2 in a substantially pure rectilinear translational movement, is achieved by the cooperation of at least one slide 4C mounted on the first piston 4 and a corresponding slide 2A formed in the cylinder 2 and extending substantially parallel to the axis XX 'of longitudinal extension of said cylinder 2. Preferably, in order to ensure a balanced guide of the first piston 4 relative to the cylinder 2, the first piston 4 is provided with two sliders arranged so that diametrically opposite the piston relative to the axis YY 'of symmetry of the latter. In order to improve the slide / slide contact, particularly in order to limit the friction which adversely affects the efficiency of the motor, each slide advantageously comprises a roller 40C rotatably mounted on an axis 400C itself mounted in an orifice 40B formed through the skirt 4B, so that said axis 400C extends substantially radially with respect to the axis of extension XX 'of the piston 4. For the sake of clarity of the figures, the second slide has not been shown on the Figures where is visible only the mounting hole 41 B, formed in the skirt 4B, for mounting this second slide. Each roller 40C is designed to roll in the corresponding slide 2A, which advantageously consists, as illustrated in the figures, in a rectilinear groove formed in the inner wall 20 of the cylinder 2, on the surface of said inner wall 20, facing the corresponding roller . The invention is however not absolutely limited to the implementation of a first piston 4 mounted in a slide connection in the cylinder 2. It is for example quite possible, without departing from the scope of the invention, that the first piston 4 undergoes, during its movement of back and forth, a rotation on itself about its axis Y-Y ', so that the movement of the first piston 4 in the cylinder 2 is not in this case a pure axial translation movement but a helical translation movement.

According to the invention, the engine 1 comprises a first passage 5 formed through the first piston 4 for communicating the interior of the chamber with the outside, said first passage 5 being designed to feed the chamber 3 with fluid of working and / or evacuate out of the chamber the burned fluid resulting from the combustion of the working fluid in the chamber 3. The first passage 5 thus makes it possible to pass fluid directly through the first piston 4 itself, from the outside to the chamber 3 and / or the chamber 3 to the outside. The invention is therefore based in particular on the idea of making the admission and / or the exhaust through a passage in the piston itself, and not in a cylinder head reported on the cylinder as in the prior art. The invention thus eliminates a bolt reported which simplifies the engine and contributes to increasing reliability while reducing the cost. This also allows a better performance thanks to the possibility of implementing very high compression rates, due to the absence of a bolt reported and the corresponding seal. However, the implementation of a bolt reported is absolutely not excluded and it is quite conceivable that an engine according to the invention comprises such a cylinder head, even if this does not correspond to a preferred embodiment.

In the example illustrated in the figures, the head 4A of the first piston 4 has a front face 40A which constitutes the top of the head 4 and which is perpendicular to the Y-Y 'axis. The front face 40A directly forms a wall of the chamber 3, and more specifically a movable wall which moves in the cylinder 2 under the effect of the movement of the first piston 4. The first passage 5 is advantageously designed to allow a transfer of fluid through this front face 40A which contributes to delimit the chamber 3. In the example illustrated in the figures, the piston head 4A has a substantially cylindrical shape with an annular side wall 4D which extends from and to the periphery of the front face 4C. The front face 4C further has a crown shaped circular concavity 400A, said concavity having a bottom from which rises a circular lateral edge. In this embodiment, the first passage 5 consists of a plurality of orifices 5A formed in a regular angular distribution in the circular edge of the concavity and opening into corresponding elongated cups 5B formed on the surface of the sidewall 4D. of the head 4A. Each cup 5B is preferably itself designed to be at the right moment with respect to a corresponding orifice 2B formed through the cylinder 2 and more precisely through the entire thickness of the tubular side wall of said cylinder 2. port 2B is itself in communication with a fuel intake component (carburetor, injector or other), and / or with the exhaust system, depending on whether the first passage 5 is used for admission and / or 'exhaust.

The combination of the orifice 5A and its corresponding cup 5B with the complementary orifice 2B thus constitutes a sealed conduit for admission of fresh gas and / or the escape of burnt gases.

As illustrated in the figures, the engine 1 comprises a first valve 6 designed to control the opening and closing of the first passage 5. In other words, the first valve 6 interacts with the first passage 5 to allow the communication of the interior of the chamber 3 with the outside through the first passage 5 or on the contrary close the first passage 5 so as to prohibit the placing in communication of the interior of the chamber 3 with the outside through the first passage 5. The first valve 6 could for example be mounted on the cylinder 2, to cooperate directly with the orifices 2B formed in said cylinder 2. However, it is much more advantageous to provide, as in the embodiment illustrated in the figures, that the first valve 6 is mounted on the first piston 4 to control the opening and closing of the first passage 5. The mounting of the first valve 6 directly on the first piston 4 allows to benefit a first passage 5 of significant useful section, which is interesting for the admission or exhaust efficiency, without complicating and weighing down the architecture of the word since the placement of the valve on the piston advantageously allows simultaneously controlling the opening / closing of all the orifices 5A contributing to form the first passage 5. It is therefore particularly advantageous to provide, as is illustrated in the figures, a unitary subassembly constituted by the first piston 4 and the first valve 6, the latter being on board the first piston 4. Preferably, the first valve 6 is slidably mounted on the first piston 4, between at least one position of closure (illustrated in particular in figure 11 ) in which it hermetically closes the first passage 5, and more precisely the orifices 5A, and on the other hand at least one open position (illustrated in particular in FIG. figure 16 ) in which it releases the first passage 5 so that the latter allows the communication through it, the chamber 3 with the outside. Advantageously, the first valve 6 has an axis of symmetry SS 'and is mounted to slide axially on the piston 4, so as to slide relative to said first piston 4 substantially parallel to the axis YY 'of said piston, the axes YY' and SS 'being merged. The mounting of the first valve 6 with axial sliding relative to the first piston 4 can be achieved by any means known to those skilled in the art. Preferably, the first valve 6 comprises at least one guide pin 7 which extends substantially radially with respect to the axis S-S ', and preferably two guide pins positioned diametrically opposite to the axis S-S '. Advantageously, each guiding pin 7 is designed to move in translation in a complementary guide oblong slot 70 formed in the skirt 4B of the piston 4. In the example illustrated in the figures, the first valve 6 more precisely comprises a lining of 6A, which is in the form of a substantially flat circular ring intended to be inserted into the concave 400A of complementary shape formed on the front face 40A of the head 4A of the first piston 4. When the first valve 6 is is in its closed position, the liner 6A is pressed to the bottom of the concavity to seal the orifices 5A. On the contrary, when the first valve 6 is in its open position, the gasket 6A is at a distance from the bottom of the concavity, which releases the orifices 5A and allows a transit of fluid through them. The lining 6A is advantageously secured, by means of arms 6B (for example three in number, angularly distributed in a regular manner), of a tubular valve skirt 6C on which each guiding pin 7 is mounted.

Advantageously, the valve skirt 6C is designed to slide inside the skirt 4B of the first piston 4, against said piston skirt 4B, the arms 6B passing through the bottom of the concavity 400A through passage openings in said bottom . Said arms 6B slide in the passage apertures in question tightly and tightly, to prevent leakage through said passage openings.

As illustrated in the figures, the engine 1 comprises an output shaft 8 mounted coaxially with the first piston 4, the output shaft 8 and the first piston 4 cooperating to convert the movement of the first piston 4 into rotary motion of the shaft 8. Preferably, the cooperation between the output shaft 8 and the first piston 4 is reciprocal, that is to say that it makes it possible to convert the rotary movement of the output shaft 8 into motion. of the first piston 4, that is to say in this case reciprocating (reciprocating) said first piston 4. The output shaft 8 preferably has a straight character and extends according to a longitudinal axis ZZ 'which is advantageously coincident with the axis XX' of the cylinder 2, and in this case with the axis YY 'of the first piston 4 and the axis SS' of the first valve 6. Preferably , the output shaft 8 passes through the first piston 4, that is to say that said first piston 4 is threaded on the output shaft 8. For this purpose, the first piston 4 is provided with a central orifice 4E through which the output shaft 8 passes, the latter being fitted tightly into the orifice 4E so as to allow the first piston 4 slide along the output shaft 8 while remaining in sealing contact with said output shaft 8, and thus avoid any communication between the inside of the chamber 3 with the outside through of the interface between the output shaft 8 and the first piston 4. It should be noted that for reasons of simplicity and clarity, a central portion of the output shaft 8, which passes through the chamber 3, has been omitted in the Figures 1 and 2 .

• les variations de pression au sein de la chambre 3, obtenues par des cycles de déflagration d'un mélange détonant (du type mélange air/carburant vaporisé), entraînent un mouvement alternatif rectiligne du premier piston 4,
• le premier piston 4 entraîne lui-même en rotation l'arbre de sortie 8, lequel constitue l'arbre moteur destiné à être raccordé à l'objet à entraîner, par exemple aux roues d'un véhicule automobile.

Preferably, the output shaft 8 and the first piston 4 cooperate directly for converting the movement of the first piston 4 into rotary motion of the output shaft 8 and vice versa. For this purpose, first piston 4 and the output shaft 8 are provided with complementary force transmission means designed to convert the reciprocating movement (of pure axial translation in the example illustrated in the figures) of the first piston 4 into rotary motion, and more precisely continuous rotational movement in a single direction of rotation, the output shaft 8. In other words, the complementary force transmission means equipping the first piston 4 and the output shaft 7 can transform the movement of rectilinear return of the first piston 4 in rotation of the output shaft 7 on itself, along its axis Z-Z '. The variant of the engine 1 according to the invention illustrated in the figures therefore operates according to the following general principle:

• the pressure variations within the chamber 3, obtained by detonation blast cycles (of the vaporized air / fuel mixture type), cause a rectilinear reciprocating movement of the first piston 4,
• the first piston 4 itself drives in rotation the output shaft 8, which constitutes the drive shaft intended to be connected to the object to be driven, for example to the wheels of a motor vehicle.

Such a design avoids the implementation of force transfer according to different working axes, as in the prior art, and allows on the contrary a direct transmission of the action of the first piston 4 on the output shaft 8. In in other words, the first piston 4 directly drives the output shaft 8 in rotation, which gives the engine 1 a particularly compact character, the latter can thus be easily integrated into the chassis of a vehicle.

Such a design is also likely to improve the center of gravity of the vehicle thanks to the essentially longitudinal nature of the vehicle. motor 1, which allows the positioning of said motor 1 according to the axis of symmetry of said vehicle. Thanks to the direct and coaxial drive of the output shaft 8 by the first piston 4, the torsional effects to which the output shaft 8 is subjected are largely minimized with respect to those imparted to the crankshafts by the connecting rods of the engines. the prior art.

Advantageously, the motor 1 comprises a first guide path 9 integral with the output shaft 8, and preferably formed (that is directly formed or attached) on the output shaft 8, on the surface of the latter . Advantageously, the engine 1 also comprises a first guide element 10 integral with the first piston 4, said first guide element 10 being mounted to move along the first guide path 9, to convert the movement of the first piston 4 into rotary motion of the output shaft 8. Advantageously, as illustrated in the figures, the first guide path 9 has a substantially undulating shape, and even more preferably a substantially sinusoidal shape. More specifically, in the example illustrated in the figures, the first guide path 9 extends along an annular profile around the longitudinal extension axis ZZ 'of the output shaft 8. Advantageously, the motor 1 comprises a first ring 8A mounted on the output shaft 8, said first ring 8A carrying said first guide path 9. The first ring 8A may thus consist of an annular piece distinct from the output shaft 8 and threaded on the latter . In this case, the first ring 8A is mounted on the output shaft 8 so as to be integral in rotation (about the axis X-X ') of the output shaft 8. It is also quite possible that the first ring 8A is made of material with the output shaft 8. Preferably, the first guide path 9 comprises a first groove 9A formed on the surface of the first ring 8A (that is to say of the output shaft 8 when the ring 8A merges with the output shaft 8) while the first guide member 10 comprises a first finger which protrudes from the first piston 4 and engages in said first groove 9A. Preferably, the first guide element 10 comprises two fingers arranged diametrically opposite relative to the axis YY 'and engaging the same first groove 9A. In order to improve the contact between the first guide element 10 and the first groove 9A, the first finger advantageously comprises a roller 10A rotatably mounted on an axis itself mounted in an orifice formed through the skirt 4B, so as to that said axis extends substantially radially relative to the extension axis XX 'of the piston 4. Preferably, the axis in question corresponds to the axis 400C on which the roller 40C is mounted. In this particularly simple and reliable embodiment, the roller 10A is mounted on the axis 400C, inside the skirt 4B, to engage the corresponding sinusoidal groove 9A, while the roller 40C is mounted on the same axis 400C , outside the skirt 4B, to engage the corresponding straight groove 2A.

As illustrated in the figures, the output shaft 8 and the first valve 6 cooperate to convert the rotary motion of the output shaft 8 into motion of the first valve 6 relative to the first piston 4. Thus, the position of the first valve 6 relative to the first piston 4, and therefore the control of the opening and closing of the first passage 5, are controlled directly by the output shaft 8, which interacts, preferably directly with the first valve 6 to outsource to the latter a movement, and for example an alternating axial translation movement as in the embodiment illustrated in the figures. To this end, the engine 1 advantageously comprises a second guide path 11 integral with the output shaft 8 and preferably formed (that is directly formed or attached) on the output shaft 8, on the surface of this last. Advantageously, the motor 1 also comprises a second guide element 12 integral with the first valve 6, said second guide element 12 being mounted to move along the second guide path 11, to convert the rotary movement of the shaft output 8 in motion of the first valve 6 relative to the first piston 4, and more particularly in reciprocating (that is to say, back-and-forth) axial axial rectilinear. Advantageously, and as illustrated in the figures, the second guide path 11 has a substantially undulating shape, and even more preferably a substantially sinusoidal shape. Preferably the second guide path does not have a purely sinusoidal profile, so as to allow at the appropriate time, the intake and exhaust, as explained in more detail below. For example, the profile of the second guide path 11 follows that of the first guide path 9 during the compression and expansion phases (the valve 6 to be closed), while during the intake and exhaust phases, the profile of the second guide path 11 is offset from that of the first guide path 9, so as to allow the opening and closing of the valve 6 in due time.

Preferably, just like the first guide path 9, the second guide path 11 extends along an annular profile around the longitudinal axis of extension ZZ 'of the output shaft 8. Advantageously, the motor 1 comprises a second ring 8B mounted on the output shaft 8, said second ring 8B carrying said second guide path 11. The second ring 8B can thus consist of an annular piece distinct from the output shaft 8 and threaded on this latest. In this case, the second ring 8B is mounted on the output shaft 8 so as to be integral in rotation (about the axis X-X ') of the output shaft 8. It is also quite conceivable that the second ring 8B comes from material with the output shaft 8.

Preferably, the first guide path 9 comprises a first groove 9A formed on the surface of the first ring 8A (that is to say of the output shaft 8 when the ring 8A merges with the output shaft 8) while the first guide member 10 comprises a first finger which protrudes from the first piston 4 and engages in said first groove 9A. In the preferred embodiment illustrated in the figures, the second guide path 11 comprises a second groove 13 formed on the surface of the second ring 8B (that is to say of the output shaft 8 when the ring 8B is confuses with the output shaft 8) while the second guide member 12 comprises a second finger which protrudes from the first valve 6 and engages in said second groove 13. Thus, it is particularly advantageous to implement a mechanical coupling between the valve 6 and the output shaft 8 which is substantially similar, in principle at least, to the mechanical coupling existing between the first piston 4 and the same output shaft 8. Preferably, the second element 12 is formed by a cylindrical rod which extends through the skirt 6C of the first valve 6, the first end of said rod, located outside of said skirt 6C, forming the pin of 7, while the second opposite end, located inside said skirt 6C, forms the second guide element itself, which extends substantially radially relative to the axis S-S '. Preferably, the second guide element 12 is formed by two cylindrical rods positioned diametrically opposite to the axis SS '(only one of these rods is shown in the figures, for the sake of simplicity and clarity of the drawings. ). Advantageously, and as illustrated in figure 12 , the first and second 8A ring, 8B are formed by a single piece in one piece, which carries both the first guide path 9 and the second guide path 11. It is however possible, in an alternative embodiment, that the first and second rings 8A, 8B are formed by separate and independent parts. In this case, it is for example advantageous that the first ring 8A is fixedly mounted (or even mobile, in translation and / or rotation) on the output shaft 8, and that the second ring 8B is mounted movably on the shaft 8, and preferably is rotatable relative to the output shaft 8 and the first ring 8A, along the axis X-X '. In this preferred embodiment, the angular position of the second ring 8B relative to the output shaft 8 can be advantageously adjusted by any appropriate means, which allows for example to adjust the intake according to the engine speed 1. It is thus sufficient to slightly rotate the second ring 8B relative to the shaft 8 to act on the speed and / or the opening moment of the first valve 6. It is also conceivable that the second ring 8B is mounted movably in translation relative to the output shaft 8, for adjusting the position of the first valve 6 as a function of the advance of the thermodynamic cycle of the engine 1.

Advantageously, the engine 1 according to the invention comprises a second piston 14 which also contributes to defining the volume of the chamber 3. Preferably and as illustrated in the figures, the engine 1 thus comprises in this case a cylinder 2 in which the first and second piston 4, 14 are mounted to slide axially. In this particularly advantageous embodiment, which is illustrated in the figures, the chamber 3 is preferably formed by the interstitial space separating the first and the second piston 4, 14 in the cylinder 2. In other words, the chamber 3 corresponds in this case to the free space of variable volume located inside the cylinder 2, between the pistons 4, 14. Advantageously, as illustrated in the figures, the first and second pistons 4, 14 are mounted in opposition within the cylinder 2, that is to say in such a way that their respective heads 4A, 14A face each other. The chamber 3 thus extends in the space delimited axially by the heads 4A, 14A of the first and second pistons 4, 14 and radially by the internal wall 20 of the cylinder 2 extending between said heads 4A, 14A of said pistons 4, 14. The chamber 3 thus has a variable volume which depends on the relative position of the first and the second piston 4,14.

Advantageously, the first piston 4 and the second piston 14 are designed to move in opposite reciprocating movements, so that said pistons 4, 14 come closer and move away from each other substantially simultaneously. In other words, the first piston 4 and the second piston 14 move symmetrically with respect to the median plane of the chamber 3, perpendicular to the axis X-X '. In the preferred embodiment illustrated in the figures, each piston 4, 14 is designed to move in the cylinder 2 individually, that is to say independently of the other piston. Preferably, the second piston 14 is identical to the first piston 4 and it is also mounted in the engine 1 identically to said first piston 4. In this advantageous embodiment, which is illustrated in the figures, the output shaft 8 is therefore also mounted coaxially with the second piston 14, the output shaft 8 and the second piston 14 cooperating to convert the movement of the second piston 14 into rotary motion of the output shaft 8. For this purpose, the engine 1 preferably comprises a third guide path 15 integral with the output shaft 8 and preferably formed (that is directly formed or reported) on the output shaft 8, on the surface of the latter. Advantageously, the engine 1 further comprises a third element of guide 16 secured to the second piston 14, said third guide member 16 being mounted to move along the third guide path 15, to convert the movement of the second piston 14 into rotary motion of the output shaft 8, together with the first piston 4. Preferably, the third guide path 15 has a substantially undulating shape which is advantageously symmetrical with the shape of the first guide path 9 with respect to the median plane of the chamber 3 perpendicular to the axis X-X ' . Advantageously, the structures of the third guide path 15 and the third guide element 16 are respectively identical to the structures of the first guide path 9 and the first guide element 10.

• une chambre 3 délimitée par deux pistons 4, 14 travaillant en opposition,
• et la réalisation d'un passage 5 ménagé au sein et à travers l'un desdits pistons pour mettre en communication l'intérieur de la chambre 3 avec l'extérieur.

Advantageously, the motor 1 comprises a third ring mounted on the output shaft 8, said third ring carrying said third guide path 15. The third ring may thus consist of an annular piece distinct from the output shaft 8 and slipped on it. In this case, the third ring is mounted on the output shaft 8 so as to be integral in rotation (about the axis X-X ') of the output shaft 8. It is also quite possible that the third ring is made of material with the output shaft 8. Preferably, the third guide path 15 comprises a third groove formed on the surface of the first ring 8A (that is to say of the output shaft 8 when the ring 8A merges with the output shaft 8) while the third guide member 16 comprises a third roller pin which projects from the second piston 14 and engages in said third groove. Finally, in the example illustrated in the figures, the motor 1 has an overall symmetry with respect to the median plane of the chamber 3, that is to say the plane which passes through the center of the chamber 3 and which is perpendicular to the axis XX 'of longitudinal extension of the cylinder 2. It is particularly interesting to combine:

• a chamber 3 delimited by two pistons 4, 14 working in opposition,
• and providing a passage 5 formed in and through one of said pistons for communicating the interior of the chamber 3 with the outside.

Indeed, when the first passage 5 is open, that is to say when the chamber 3 is placed in communication with the outside through said first passage 5, the movements of back and forth of the first piston 4 provide less effective compression and suction effects, since the pushing or suction section of said piston 4, which corresponds to the front face 40A is then not sealed (since the valve 6 is open).

The implementation of a second piston 14 working in opposition with the first piston 4 makes it possible to overcome this lack of compression and suction by the simultaneous work of the second piston, which comes to reinforce the first piston 4 in the phases of suction and compression.

Preferably, the engine 1 comprises a second passage 17 formed through the second piston 14 for communicating the interior of the chamber 3 with the outside. Preferably, in the double-piston architecture illustrated in the figures, the second passage 17 formed in the second piston 14 is designed to supply the chamber 3 with working fluid, that is to say in fresh mixture intended to undergo a combustion, while the first passage 5 of the first piston 4 is designed to discharge from the chamber 3 the burned fluid resulting from the combustion of the working fluid in the chamber 3. Thus, the admission is through the second piston 14 while the exhaust is through the first piston 4. Such a design is particularly advantageous for producing an engine operating in a four-cycle cycle, as will be described in more detail in the following.

• une chambre 3 conçue pour accueillir un fluide de travail destiné à subir une combustion au sein de ladite chambre 3,
• un premier piston 4 et un deuxième piston 14 qui contribuent tous deux à délimiter le volume de ladite chambre 3,
• un premier passage 5 ménagé à travers ledit premier piston 4 pour mettre en communication l'intérieur de la chambre 3 avec l'extérieur, ledit premier passage 5 étant conçu pour évacuer hors de la chambre 3 le fluide brûlé résultant de la combustion du fluide de travail,
• un deuxième passage 17 ménagé à travers ledit deuxième piston 14 pour mettre en communication l'intérieur de la chambre 3 avec l'extérieur, ledit premier passage 5 étant conçu pour alimenter la chambre 3 en fluide de travail,

constitue en tant que tel une invention indépendante.Moreover, an internal combustion engine 1 comprising:

• a chamber 3 designed to receive a working fluid intended to undergo combustion within said chamber 3,
• a first piston 4 and a second piston 14 which both contribute to delimiting the volume of said chamber 3,
• a first passage 5 formed through said first piston 4 for communicating the interior of the chamber 3 with the outside, said first passage 5 being designed to evacuate from the chamber 3 the burned fluid resulting from the combustion of the fluid of job,
• a second passage 17 formed through said second piston 14 for communicating the interior of the chamber 3 with the outside, said first passage 5 being designed to supply the chamber 3 with working fluid,

constitutes as such an independent invention.

Of course, it is particularly advantageous to provide, with respect to the second piston 14, technical measures identical to those used on the first piston 4. This means that in this example, the engine 1 comprises a second identical valve 18 at the first valve 6, said second valve 18 being mounted on the second piston 14 to control the opening and closing of the second passage 17 formed through the second piston 14. Similarly, the output shaft 8 and the second valve 18 cooperate to convert the rotary motion of the output shaft 8 into motion of the second valve 18 relatively to the second piston 14. For this purpose, the engine 1 comprises on the one hand a fourth guide path 19 integral with the output shaft and preferably formed on the output shaft 8 and on the other hand a fourth element of guide 21 secured to the second valve 18, said fourth guide element 21 being mounted to move along the fourth guide path 19, to convert the rotary movement of the output shaft in motion of the second valve relative to the second piston . Advantageously, the fourth guide path 21 has a substantially corrugated shape, even more preferably substantially sinusoidal. The structure of the second valve 18, the second piston 14 and the corresponding part of the shaft 8 which cooperates with both the second valve 18 and the second piston 14 will not be described in more detail, since as indicated in this above, the motor 1 advantageously has a symmetry with respect to the median plane of the chamber 3.

The operation of the motor 1 illustrated in the figures will now be described in the context of a four-stroke cycle.

The first stage of the engine's operating cycle, which is illustrated in Figures 3 and 4 , corresponds to a step of admission of the working fluid, which is preferably constituted by a mixture of air and vaporized fuel, in the combustion chamber 3. For this purpose, the second valve 18 is in the open position, in order to allow admission, through the second piston 14 via the second passage 17, fresh working fluid from the outside of the cylinder 2.

During this first period, the first and the second piston 4, 14 undergo a movement of mutual separation which creates a depression in the combustion chamber 3, which promotes the aspiration of the working fluid through the second passage 17, the second valve 18 being open to allow the introduction of working fluid into the combustion chamber 3. The first valve 6 which equips the first piston 4 is closed, which ensures an excellent suction effect under the effect of displacement of the first piston 4, this suction effect compensating for the weaker suction effect generated by the second piston 14, the valve 18 is open.

Once they reach their maximum mutual distance (shown in figure 4 ), the pistons 4, 14 undergo an inverse movement of mutual approximation, that is to say that they come closer to each other ( figure 5 ) in order to compress the working fluid contained in the chamber 3. In this phase of mutual reciprocation of the pistons, which corresponds to the second stage, the first and the second valve 6, 18 are closed so as to produce a compression effect of the working fluid between the pistons 4, 14. The working fluid is thus strongly compressed, which causes its heating.

When the pistons 4, 14 reach their minimum point of separation (the pistons are then in the so-called " top dead center " position), illustrated in FIG. figure 6 , the compressed working fluid at maximum explodes either under the effect of ignition obtained by the production of a spark generated by a candle (not shown) or under the effect of the compression ratio itself, which produces a heating as the working fluid explodes spontaneously (case of a diesel engine).

This explosion phase produces a relaxation and an expansion of the gases constituting the working fluid. This expansion generates a high pressure in the chamber (for example between 40 and 100 bar) which is exerted on the pistons, whose valves 6, 18 are closed. This causes the pistons 4, 14 to move apart.

This spacing of the pistons 4, 14 under the effect of the pressure resulting from the explosion in the chamber rotates the output shaft 8. Thus, this phase of explosion and relaxation (which corresponds to the third stroke) creates thermal energy which is converted into mechanical energy of rotation of the output shaft 8. The pistons 4, 14 then come closer again, which creates a compression in the chamber 3.

At this moment, the first valve 6 of the first piston 4 is open, which allows, under the effect of compression performed by the mutual movement of the pistons 4, 14, to escape the burnt working fluid through the first passage 5.

At the end of this fourth time, the engine 1 is found in the configuration corresponding to the first time and is ready to start again the four-stroke cycle just described.

The invention also relates as such to a vehicle, of the motor vehicle type, equipped with a motor 1 according to the invention.

The invention also relates independently to a piston 4 designed to form the first piston 4 of a motor 1 according to the invention.

Finally, the invention also relates to a valve designed to form the first valve 6 of a motor 1 according to the invention.

POSSIBILITY OF INDUSTRIAL APPLICATION

The invention finds its industrial application in the design, manufacture and use of motors.

Claims (12)

1. An internal combustion engine (1) comprising:

   - a chamber (3) designed to receive a working fluid intended to undergo combustion within said chamber (3);

   - a first piston (4) and a second piston (14), which both contribute to delimiting the volume of said chamber (3);

   said engine (1) being characterized in that

   - a first passageway (5) is provided through said first piston (4) in order to bring the inside of the chamber (3) into communication with the outside, said first passageway (5) being designed to discharge, out of the chamber (3), the burnt fluid resulting from the combustion of the working fluid;

   - a second passageway (17) is provided through said second piston (14) in order to bring the inside of the chamber (3) into communication with the outside, said second passageway (17) being designed to supply the chamber (3) with the working fluid,

   said engine (1) comprising an output shaft (8) mounted coaxially with said first piston (4), the output shaft (8) and the first piston (4) cooperating so as to convert the motion of the first piston (4) into rotational motion of the output shaft (8), the first piston (4) and the output shaft (8) being provided with complementary load transmission means designed to convert the reciprocating motion of the first piston (4) into rotational motion of the output shaft (8), so that the first piston (4) rotates the output shaft (8) directly, said first piston (4) being fitted over the output shaft (8), said engine comprising a first valve (6) mounted on the first piston (4) in order to control the opening and closing of said first passageway (5), the first piston (4) and the first valve (6) forming a unitary subassembly, said first valve (6) being mounted on the first piston (4), the output shaft (8) and the first valve (6) cooperating to convert the rotational motion of the output shaft (8) into motion of the first valve (6) relative to the first piston (4), the output shaft (8) interacting directly with the first valve (6) in order to impart a motion to the latter, in such a manner that the position of the first valve (6) relative to the first piston (4) is controlled directly by the output shaft (8).
2. The engine (1) as claimed in claim 1, characterized in that it comprises a cylinder (2), which is preferably in the form of a hollow straight tube, within which the first and second pistons (4, 14) are mounted so as to slide axially, said chamber (3) being formed by the intervening space separating said pistons (4, 14) in the cylinder (2).
3. The engine (1) as claimed in claim 2, characterized in that said first and second pistons (4, 14) are mounted opposite each other within the cylinder (2).
4. The engine (1) as claimed in one of claims 1 to 3, characterized in that the first piston (4) and the second piston (14) are designed to move so as to undergo opposed reciprocating motions.
5. The engine (1) as claimed in one of claims 1 to 4, characterized in that the cooperation between the output shaft (8) and the first piston (4) is reciprocal, that is to say it enables the rotational motion of the output shaft (8) to be converted into the motion of the first piston (4).
6. The engine (1) as claimed in one of claims 1 to 5, characterized in that it comprises, on the one hand, a first guide path (9) integral with the output shaft (8) and, on the other hand, a first guiding element (10) integral with the first piston (4), said first guiding element (10) being mounted so as to move along the first guide path (9), in order to convert the motion of the first piston (4) into rotational motion of the output shaft (8).
7. The engine (1) as claimed in one of claims 1 to 6, characterized in that it comprises an output shaft (8) mounted coaxially with said second piston (14), the output shaft (8) and the second piston (14) cooperating to convert the motion of the second piston (14) into rotational motion of the output shaft (8).
8. The engine (1) as claimed in one of claims 1 to 7, characterized in that it comprises, on the one hand, a second guide path (11) integral with the output shaft (8) and, on the other hand, a second guiding element (12) integral with the first valve (6), said second guiding element (12) being mounted so as to move along the second guide path (11), in order to convert the rotational motion of the output shaft (8) into motion of the first valve (6) relative to the first piston (4).
9. The engine (1) as claimed in claim 8, characterized in that the position of said second guide path (11) relative to the output shaft (8) can be adjusted in rotation and / or in translation.
10. The engine (1) as claimed in any one of preceding claims, characterized in that it comprises a second valve (18) mounted on the second piston (14) in order to control the opening and closing of said second passageway (17).
11. The engine (1) as claimed in claim 10, characterized in that the output shaft (8) and the second valve (18) cooperate to convert the rotational motion of the output shaft (8) into motion of the second valve (18) relative to the second piston (14).
12. The engine (1) as claimed in one of claims 1 to 11, characterized in that it is designed so as to operate with the following four-stroke cycle:

    - during the first stroke of the operating cycle of the engine, the first and second pistons (4, 14) move further apart, which creates a vacuum in the combustion chamber (3), thereby forcing the working fluid to be sucked in via the second passageway (17), the second valve (18) being opened to allow the working fluid to enter the combustion chamber (3) through the second piston (14) via the second passageway (17), the first valve (6), with which the first piston (4) is equipped, being itself closed;

    - once they have arrived at their positions furthest apart, the pistons (4, 14) move closer together, which corresponds to the second stroke, that is to say they approach each other so as to compress the working fluid contained in the chamber (3) while the first and second valves (6, 18) are closed so as to compress the working fluid between the pistons (4, 14);

    - when the pistons (4, 14) reach their point closest together, the working fluid compressed to the maximum explodes through the ignition effect obtained by producing a spark generated by a spark plug or through the effect of the compression ratio itself, which heats the working fluid such that it explodes spontaneously;

    - this explosion phase produces an expansion of the gases constituting the working fluid, generating a high pressure in the chamber (3) which is exerted on the pistons (4, 14), the valves (6, 18) of which are closed, thereby causing the pistons (4, 14) to move apart;

    - this moving-apart of the pistons (4, 14) through the effect of the pressure resulting from the explosion in the chamber (3) makes the output shaft (8) rotate;

    - the pistons (4, 14) then come closer together again, which creates a compression in the chamber (3);

    - at this moment, the first valve (6) of the first piston (4) is opened, thereby making it possible, through the compression effect produced by the pistons (4, 14) moving closer together for the burnt working fluid to be exhausted through the first passageway (5);

    after this fourth stroke, the engine (1) is again in the configuration corresponding to the first stroke and is ready, once again, to start the four-stroke cycle.

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