EP0152321B1 - Device for controlling the opening and closing of the combustion chamber of an internal-combustion engine - Google Patents

Description

The present invention applies to a device for controlling the circulation of gases to and from a combustion chamber of an internal combustion engine, constituted by a rotary plug or rotor comprising at least one internal channel or a lateral cut defining passages of 'respective exhaust or intake transverse flow, a passage directly connected to the combustion chamber, the plug being contained in a transverse bore into which opens the orifice of said passage arranged in a sealing ring which is housed in a bore, in which it slides, the sealing ring being applied to the rotor by a continuous contact surface around the orifice of the passage under the effect of the pressure prevailing in the combustion chamber being surrounded by one or several sealing members such as segments, and being provided with means for injecting oil on the plug.

According to a known embodiment of this type of motor (French patent applications FR-A-2,531,139 and FR-A-2,531,174) making it possible to rotate at high rotational speeds, the plug is contained in a transverse bore into which opens the orifice connected directly to the combustion chamber and the intake and / or exhaust orifices connected respectively to an exhaust manifold. The passage connected to the combustion chamber is arranged in a sealing ring housed in an applied bore, on the plug by a continuous sealing surface around the orifice connected directly to the combustion chamber, under the effect of the pressure prevailing in the combustion chamber, and surrounded by one or more, sealing members such as segments, this ring being able to slide in the bore and its stroke being limited, on one side, by the plug and, on the other side, by a retaining shoulder.

Such combustion engines appear capable of delivering mass powers much higher than known and proven solutions, in particular for small displacement engines, due to the absence of distribution parts subjected to an alternating movement generating a beat limit frequency. The most decisive advantage of this type of distribution lies in the possibility of having exhaust and intake ducts twice the diameter of a conventional valve system, which allows for better filling. and therefore a higher specific power.

After a first in-depth experiment with rotary valve distribution devices, it turns out that these distribution rotor systems have drawbacks or operational flaws which have not made it possible to exploit the advantages listed above. .

Among these various drawbacks, mention may be made of the difficulties in ensuring the lubrication and cooling of the sealing elements, which causes excessive wear of the plug and of the sealing elements and elements, a high consumption of lubricant, and can lead to, in certain borderline cases, seizure of the bushel in its bore.

• - une dilution des gaz frais par les gaz d'échappement se traduisant par une mauvaise combustion et une pollution plus importante;
• - une introduction du mélange carburé dans le gaz d'échappement entraînant aussi une augmentation de la pollution et de la consommation spécifique en carburant.

Furthermore, when the rotary valve distribution is applied to four-stroke engines, there is no reduction in the specific fuel consumption compared to engines operating according to the two-stroke cylinder. This overconsumption of fuel appears to be due to an insufficient separation of the ducts or of the intake and exhaust phases which leads to:

• - dilution of the fresh gases by the exhaust gases, resulting in poor combustion and greater pollution;
• - introduction of the fuel mixture into the exhaust gas also resulting in an increase in pollution and specific fuel consumption.

US-A-4,114,639 describes a rotary valve used for controlling the circulation of gases to and from a combustion chamber of an internal combustion engine and into which the lubricant is supplied using porous plugs between the member of the rotating valve and the inner surface of the valve body supporting this rotating member. However, the seal between the insert forming an annular seal and the rotating member forming the supply and exhaust distributor cannot be maintained over time. There is in fact no means of placing the insert on the member other than that due to the oil pressure or the combustion pressure of the chamber. This known system has the drawback, in the event of wear on contact between the insert and the rotating member, an exhaust gas leak is established towards the oil supply line and a discharge of lubricating oil, followed by seizure of the rotating contact.

One of the aims of the present invention is precisely to overcome these defects of combustion engines with rotary distribution in order to allow the large passage sections offered by this type of their distribution to be used without risking rapid wear and consumption of exaggerated fuel.

To this end, according to a first embodiment of the invention, the sealing ring is crossed at least at its periphery by a pressurized oil circuit heading towards the oil return and capable of ensuring cooling. of this ring and the injection means are connected to said oil circuit, pass axially through at least part of the annular section of the ring and open into a continuous annular distribution groove which is formed inside the continuous contact surface established on a strip of small width along the general line of intersection of two cylinders and which opens on the interface existing between this contact surface and the external surface of the rotor.

The means for injecting the fluid consist, on the one hand, of an annular oil intake and circulation chamber, delimited between the periphery of the sealing ring and its bore and axially limited at each end by a seal interposed between the outer surface of the sealing ring and the bore and, on the other hand, by at least one supply passage having an outlet opening opening into said interface between the surface continuous sealing and the outer surface of the plug and in that at least one gun sealing segment is interposed between on the one hand the sealing ring and its bore and on the other hand said seal located on the side of the combustion.

The annular inlet chamber is traversed by a large flow of pressurized oil directing through an outlet pipe towards another member to be lubricated or the discharge.

According to another embodiment of the device, an end part of at least one supply member for one of the combustion elements, for example a spark plug for a spark-ignition engine or an injector, and / or a heating plug for a diesel cycle engine, crosses in a leaktight manner the cross section of the sealing ring to open into the passage which is connected to the combustion chamber, and in that the adjacent part of said end part is housed with an annular clearance in a supply passage towards the outside of said combustion element, said supply passage being connected to the annular fluid intake chamber.

As a variant, the passage giving rise to the annular clearance is traversed by a flow of the fluid brought to the annular fluid admission chamber.

When the device controlling the circulation of gases from and to the combustion chamber of the engine is applied to a heat engine, the passage giving rise to the annular clearance is extended towards the outside by an enlarged annular chamber, which is closed by a seal. elastic ring interposed between the supply member and the inner wall of said chamber and delimiting a cooling chamber traversed by said fluid flow. The sealing ring is, on the one hand, made of a soft material having good rubbing qualities with the surface of the plug, for example plastic, and, on the other hand, permanently pushed back on the surface of the plug under a substantially constant pressure by a spring.

According to one embodiment of the invention, applied to a heat engine where the rotor simultaneously serves to control the exhaust of the engine and the admission of the mixture of fuel and combustion air into the combustion chamber, scraper means lubricating fluid injected into the interface are arranged around the intake orifice connecting the rotor to the intake of the mixture of combustion air and engine fuel, these scraper means being constituted by a sealing ring intake disposed at the periphery of said intake port, which comes into continuous support on the outer surface of the plug and which is capable of isolating the interior of the intake port from the interface between the plug and its bore to limit the entrainment of oil and liquid fuel simultaneously on the surface of the rotating plug.

According to another embodiment of the invention, the sealing ring is, on the one hand, made of a soft material having good rubbing qualities with the surface of the plug, for example plastic, and, on the other hand part, permanently pushed back on the surface of the plug under a substantially constant pressure by a spring. According to another embodiment of the invention, the plug has two separate inlet and outlet passages respectively which are capable of successively opening both by rotation of the plug, on the side of the combustion chamber, on the sealing ring and, on the side opposite to the combustion chamber, on outlet orifices which are each offset on the axis of the plug relative to the sealing ring, so as to reduce the entrainment of the fuel to the surface of the plug and the fuel entrained at the intake in the intake passage formed inside the plug.

According to yet another embodiment of the invention, the separate intake or exhaust passages of two neighboring combustion chambers are provided in the plug, opening onto an orifice for communication with the intake or the exhaust which is common to the two adjacent combustion chambers, so as to reduce the number of openings to be provided on the outside face of the plug.

According to one embodiment of the invention, applied to a heat engine operating according to the four-stroke cycle, the intake circuit of the combustion chamber includes means for removing fuel from the air drawn into the combustion chamber. combustion before the end of admission. In the case where the fuel is introduced by injection into the intake air, the abovementioned suppression means consist of stopping the injection of fuel clearly before the end of the suction phase.

In the case where the fuel is introduced into the combustion chamber via a carburetor, the abovementioned suppression means are then preferably constituted by at least one auxiliary passage of air rich in fuel such as an emulsion, formed in the plug and cylinder head of the combustion chamber and the auxiliary passage leads to the interface between the plug and its bore at a point such that it is closed by the rotation of the plug before the main opening (s) (s) of admission not the self.

According to one embodiment of the invention, in the case where the fuel is introduced by injection into the intake air, the suppression means are constituted by stopping the injection of fuel clearly before the end of the suction phase.

According to another embodiment of the invention, the suppression means are constituted by at least one auxiliary passage of air rich in fuel, formed in the plug and the cylinder head of the combustion chamber and which opens onto the interface between the rotor and its bore in an orifice which is closed off by the rotation of the rotor before the main opening (s) of inlet (s) are self-contained.

According to yet another variant of the device according to the invention, the passage giving rise to the annular clearance is extended towards the outside by an enlarged annular chamber, said annular chamber being closed by an elastic annular seal which is interposed between the inlet and the inner wall of said chamber and which delimits a cooling chamber through which the lubricating and cooling fluid flows brought in by the injection means. This enlarged part allows a tool to access the feed member. US-A-4,114,639 describes a rotary valve used for controlling the circulation of gases to and from a combustion chamber of an internal combustion engine and into which the lubricant is supplied using porous plugs between the member of rotating valve and the lower surface of the valve body supporting this rotating member. However, the seal between the insert forming an annular seal and the rotating member forming the supply and exhaust distributor cannot be maintained over time. There is in fact no means of placing the insert on the organ other than that due to the oil pressure or to the combustion pressure of the chamber. This known system has the drawback, in the event of wear on contact between the insert and the rotating member, an exhaust gas leak is established towards the oil supply line and a discharge of lubricating oil, followed by seizure of the rotating contact.

• les figures 1 et 2 sont des vues en coupe et à grande échelle de deux modes de réalisation du système d'étanchéité selon l'invention entre un boisseau de distribution tournant et une chambre de combustion de moteur;
• les figures 3a à 3c illustrent schématiquement les principales positions au cours d'un cycle moteurd'un système de distribution à boisseau appliqué à un moteur fonctionnant selon le cycle à quatre temps;
• la fig. 4 est une vue en coupe à grande échelle du système de distribution à boisseau représenté schématiquement sur les figures 3a à 3c et équipé d'un anneau d'étanchéité d'admission selon l'invention;
• la fig. 5 est une vue en coupe, toujours à grande échelle, d'un autre mode de réalisation du système de distribution à boisseau selon l'invention comportant des conduits d'admission et d'échappement séparés à l'intérieur du boisseau;
• la fig. 6 est une vue en coupe avec arrachements selon la ligne VI-VI de la fig. 5, d'une partie du boisseau de distribution d'un moteur comportant plusieurs cylindres parallèles;
• la fig. 7 est une vue en coupe à grande échelle d'un système de distribution à boisseau selon l'invention dans lequel sont prévus des moyens d'appauvrissement en carburant de l'air aspiré en fin d'admission;
• les figures 8 et 9 sont des coupes respectivement selon les lignes VIII-VIII et IX-IX du système de distribution représenté à la figure 7;
• la fig. 10 est une vue en coupe du système d'étanchéité selon l'invention comportant une bougie d'allumage débouchant dans la chambre de combustion;
• la fig. 11 est une vue en coupe du système d'étanchéité selon l'invention comportant une bougie d'allumage débouchant directement dans le passage de l'anneau d'étanchéité.

Other objects, advantages and characteristics of the control device according to the invention will appear on reading the description of various embodiments, given without limitation and with reference to the appended drawing where:

• Figures 1 and 2 are sectional views on a large scale of two embodiments of the sealing system according to the invention between a rotating distribution valve and an engine combustion chamber;
• FIGS. 3a to 3c schematically illustrate the main positions during a motor cycle of a plug distribution system applied to an engine operating according to the four-stroke cycle;
• fig. 4 is a sectional view on a large scale of the plug distribution system shown diagrammatically in FIGS. 3a to 3c and equipped with an intake sealing ring according to the invention;
• fig. 5 is a sectional view, still on a large scale, of another embodiment of the valve distribution system according to the invention comprising separate intake and exhaust ducts inside the valve;
• fig. 6 is a sectional view with cutaway along line VI-VI of FIG. 5, of a part of the valve plug of an engine comprising several parallel cylinders;
• fig. 7 is a sectional view on a large scale of a plug distribution system according to the invention in which means are provided for depletion of fuel from the air sucked in at the end of intake;
• Figures 8 and 9 are sections respectively along lines VIII-VIII and IX-IX of the distribution system shown in Figure 7;
• fig. 10 is a sectional view of the sealing system according to the invention comprising a spark plug opening into the combustion chamber;
• fig. 11 is a sectional view of the sealing system according to the invention comprising a spark plug opening directly into the passage of the sealing ring.

In FIGS. 1 and 2, a rotary plug 1 for distributing the exhaust of a combustion chamber 2 of a heat engine is shown at the moment when its internal exhaust channel 3 is opened wide on the combustion chamber 2. The plug 1 turns, continuously and synchronously with the rotation of the engine, in a bore 4 and the exhaust channel 3 is connected to the combustion chamber 2 by a passage 5 of relatively large dimension formed in a ring seal 6 which can slide freely in a bore 7 with an axis substantially parallel to that of the engine cylinder (not shown) or substantially perpendicular to the axis of rotation of the plug 1, so as to ensure good bearing of the surface of contact of the ring 6 on the outer surface 8 of the plug 1. The contact surface 22 between the ring 6 and the plug 1 is established on a strip of small width along the general line of intersection of two cylinders (the exterior surfaces of the wood bucket 1 and ring 6 of different diameters and substantially perpendicular and concurrent axes. According to a known arrangement which is particularly effective because it provides the force for applying the sealing ring 6 on the plug 1 to the pressure to be sealed, the sealing ring 6 which moves with gentle friction in its bore 7 is applied to the outer surface of plug 1 by the single pressure prevailing in combustion chamber 2 and acting on its annular section, increased if necessary by the thrust of a spring with low reaction force such as a washer elastic. The presence of this thrust spring (not shown) of the ring 6 on the plug 1 is not essential if there is only a slight clearance or interface i between the end 9 of the ring 6 of the side of the combustion chamber 2 and a retaining shoulder 10 formed at the end of the bore 7 receiving the ring 6. In addition, the temperature being relatively high in the interface i because of the proximity of the chamber 2 combustion, the holding over time of a spring member is very random. In order to eliminate leaks in the interface j between the outer surface of the ring 6 and the interior of its bore 7, a gun sealing segment 11 is disposed in a known manner in this interface j and is worn by a groove 12 preferably made in the ring 6. The segment 11 also prevents overheating of the interface j in the direction of the plug 1 and the formation in this interface of deposits which would end up blocking the ring 6 in its bore 7 .

According to the invention, the sealing ring 6 is provided with means for injecting a lubricating and cooling fluid, preferably engine lubricating oil pressurized by the engine oil pump, into the interface e between the continuous sealing surface 22 (along the general line of orthogonal intersection of two cylinders of different diameters) around the orifice 3 formed in the plug 1 and the external surface 8 of the plug 1.

According to the device shown in fig. 1, the fluid injection means comprise a line 13 for supplying pressurized oil usually connected to the engine lubrication pump and leading to an annular distribution chamber 14, delimited in the interface j between the periphery of the ring 6 and its bore 7 for example using a cir groove cular 15 formed at the periphery of the sealing ring 6. According to an arrangement favoring the cooling of the ring 6, the chamber 14 can be traversed by a large flow of oil under pressure moving towards another member to be lubricated or discharge via an outlet pipe 16. The chamber 14 is delimited in the interface j by two annular seals 17 and 18 disposed respectively on the side of the combustion chamber 2 and on the side of the plug 1. The annular seals 17 and 18 are preferably made of a resistant elastomeric material for seal housed by elasticity in annular grooves formed on the outer surface of the ring 6 because the gun segment 11 1 and the circulation of oil protect against excessive temperature.

The oil distribution chamber 14 is connected to the interface e between the sealing surface of the ring 3 and the external surface 8 of the plug 1 by supply passages 19 made, preferably, by a longitudinal bore. in the thickness of the ring, connected to a transverse bore 20 from the bottom of the circular groove 15. The supply passages 19 can lead to the interface e directly by an outlet chamfer or else in an annular groove continuous distribution 21 formed inside the contact or sealing surface 22 of the ring 6, this in order to better distribute the oil in the interface e. It should be noted that the channel 6 formed inside the rotary valve 1 can be a channel for the admission of fresh gases (normally pressurized air or at atmospheric pressure) fueled or not, or else an exhaust channel combustion gases as described above and that the channel 3 can be replaced, as will be seen hereinafter, by a lateral notch successively filling, during the rotation of the plug, the functions of intake and exhaust passage.

The operation of the device for controlling the circulation of gases from and / or to an engine combustion chamber, as shown in FIG. 1 will now be explained. As soon as the motor is put into rotation, it drives the plug 1 in synchronous rotation and it generates an oil pressure which is transmitted to the distribution chamber 14 and to the annular groove 21 to cause a thin blade of oil to flow between the sealing surface 22 of the ring 6 and the movable external surface 8 of the plug 1. The pressure prevailing in the combustion chamber

tion 2 during the compression and gas combustion phases strongly applies the sealing surface 22 to the outer surface 8 of the plug 1 and reduces the thickness of this oil blade to a minimum value just sufficient to ensure a film of oil between the surface of the plug 1 and the sealing surface 22. During the sweeping and suction phases (for running the engine according to the four-stroke cycle) where the pressure in the combustion chamber 2 is close to atmospheric pressure or slightly higher than this (case of the supercharged engine), the friction hysteresis of the gun segment 11 of the ring 6 on the plug 1 maintains a significant residual application force of the ring 6 on the plug 1. This residual force limits oil leaks between the sealing surface 22 and the surface 8 of the plug at a flow rate just sufficient to ensure a continuous film of oil between the surface 8 of the plug 1 and its guide bore 4. When the can al 3 inside the plug 1 is an exhaust channel, the oil leaks to the interior passage 3-5 are carried to the exhaust and therefore lost, while when the channel 3 is an intake channel , the oil leaks to the passage 5 are brought back into the combustion chamber 2 and thus at least partially reused.

Thanks to the continuous lubrication of the interface e, the wear of the sealing surface 22 of the ring 6 is reduced to a minimum value and the risks of seizure at high speed of the ring 6 on the plug 1 are deleted. The temperature of the surface of the plug 1 (moreover generally cooled internally by a longitudinal circulation of water) is considerably reduced and the seal between the plug and its bore 4 is ensured by an oil wedge. The circulation in diversion of the oil between the supply pipe 13 and the outlet pipe 16 ensures an energetic cooling of the sealing ring 6 which could thus in certain application cases be made of a relatively soft material and good rubbing quality such as high strength molded plastic.

The sealing ring 6 as well as the plug 1 can be produced, preferably, in the different friction couples usually used in engines such as: cast iron / chrome, cast iron / cast iron, etc., but also in new composite materials , ceramics or other new products. A calibrated orifice (not shown) can be placed on the inlet pipe 13 or on the supply passages 19 in order to limit the flow of oil escaping from the interface e when the pressure drop caused by the passages is insufficient to limit the oil leakage rate.

In the embodiment shown in FIG. 2, the elements identical to those shown in FIG. 1 have the same reference numbers. Unlike fig. 1, the sealing ring 6 can be made of porous sintered metal with a sealing plating on the surfaces which should not give rise to an exudation of oil, or else as shown in FIG. 2, an annular ring or cartridge 23 made of porous sintered metal, such as bronze, is introduced or molded in a blind housing 19a formed longitudinally in the sealing ring 6. This porous ring 23 is connected by at least one lateral passage 20 to the oil pressure distribution chamber 14. The porous ring 23 thus functions as a pressure drop and oil distribution member in the interface e and as a good-quality rubbing member reducing the friction between the ring 6 and the rotary plug 1. This arrangement which appears suitable for cases where the speed of rotation of the plug 1 is moderate and where vigorous cooling of the sealing ring 6 is not required, reduces oil losses and is generally more economical to implement than the solution shown in fig. 1.

FIGS. 3a to 3c schematically represent the most characteristic positions of a plug 1 provided, not with an internal channel, but with a notch 24 intended to ensure the distribution (suction and exhaust) of a combustion chamber 2 of an internal combustion engine operating according to the four-stroke cycle. In fig. 3a, it can be seen that the notch 24 connects the combustion chamber 2 of the engine (via a sealing ring of the type described in FIGS. 1 and 2 and not shown) to a suction pipe 25 provided with introduction means fuel such as a carburetor or injector, if the engine is operated with a positive ignition. In fig. 3b, the plug 1 has turned counterclockwise and has closed both the suction pipe 25 and the exhaust pipe 26. It can be seen that the notch 24 of the plug 1 delimits with the guide bore 4 valve 1 a passage chamber 27 of a significant volume and which is then isolated from the intake and exhaust. The chamber 27 was filled during the intake phase with air relatively rich in fuel since it was sucked in after the walls of the suction pipe were saturated with liquid fuel. We see in fig. 3c that the air rich in fuel contained in the passage chamber 27 is completely discharged to the exhaust 26, in particular as a result of the arrival of the puff of exhaust gas at the time of setting up communications (not shown) of the combustion chamber 2 with the chamber 27 when the edge 28 of the notch 24 opens onto the passage 5 connected to the combustion chamber 2.

Another source of overconsumption of fuel when the engine equipped with a rotary distributor valve operates according to the four-stroke cycle with fuel air supply, lies in the fact that the liquid fuel which flows on the suction wall and s' gradually evaporates in the direction of the combustion chamber, is entrained on the surface of the plug 1 in the direction of the exhaust 26 where the hot gases evaporate it and carry it away in pure exhaust in the exhaust with the film of oil deposited by the lubrication device shown in Figures 1 and 2.

Figure 4 shows, on a larger scale, a solution to reduce fuel and oil losses. Elements identical to those in FIGS. 1 to 3c are given the same reference numbers. In this embodiment, oil scraper means are arranged around the air intake orifice on the plug 1. The scraper means are constituted by an intake sealing ring 29 permanently applied to the surface 8 of the plug 1 by a spring 30. According to another arrangement of this embodiment, the fuel introduction means constituted here by a petrol injector 31 are adjusted so that the injection is cut off well before the end of the combustion air suction phase. The sealing ring 29 housed in the cooled cylinder head 32 of the engine and through which the fresh intake gases pass is neither subjected to high temperatures nor to significant pressure differences (the overpressures and depressions are less than 1 bar) and as a result, it can be made of a good rubbing plastic material such as Teflon.

The operation of the embodiment shown in FIG. 4 is described below. The plug 1 rotates in synchronism with the motor and receives from the supply passages 19 and the distribution groove 21 an oil film which is driven on its surface 8. The oil film formed in the interface between the plug and the bore 4 is stopped by the sealing ring 29 substantially of the same width as the main sealing ring 6. The injection of fuel by the injector 31 begins as soon as the edge 28 of the notch 24 leads to the inner passage 33 of the suction ring 29 and stops well before the other edge 34 of the notch 24 reaches the right edge 35 of the passage 5 formed inside the ring 6 and does not cut off the intake. From the start of the injection of the fuel, part of it is vaporized in the jet of aspirated air while the other stops on the walls and is entrained towards the combustion chamber 2 by gradually evaporating . Thanks to the stop of the injection well before the end of the aspiration (while respecting the conditions of the almost stoichiometric mixture in the combustion chamber 2), the walls contain only a small amount of liquid fuel at the time of the intake shutdown and the flow chamber 27 is very poor in fuel. The liquid fuel which stagnates inside the passage 33 is stopped by the friction of the sealing ring 29 and cannot therefore be entrained towards the exhaust until the air intake resumes at following suction cycle and does not carry into the combustion chamber 2 this liquid fuel which has largely evaporated during the rest of the engine cycle. The arrangements shown in fig. 4 considerably reduce the amount of fuel driven directly to the exhaust and allow a four-stroke cycle operating with a notched bushel and with reasonable consumption while benefiting from significantly increased passage sections of the distribution by rotary bushel.

Another embodiment of the device for controlling the circulation of gases to and from an engine combustion chamber is shown in FIGS. 5 and 6 in which the elements and members identical to those of the preceding figures have the same reference numbers. In this embodiment, the plug 1 has two separate inlet and outlet passages 36 and 37 respectively. Each of these two passages successively opens by rotation of the plug 1 on the side of the combustion chamber 2 on the ring d seal 6 and, on the opposite side, on orifices which are laterally offset with respect to the seal ring 6. The intake passage 36 opens from one side of the cylinder head onto the suction pipe 25 surrounded by its suction seal ring 29.

When the plug 1 has turned to come into full exhaust position, the exhaust passage 37 opens onto the passage 5 inside the ring 6 and onto the exhaust pipe 26 offset along the axis of the plug 1 with respect to the sealing ring 6.

According to the detail of the section of FIG. 6, it can be seen that inside the plug 1, the two intake passages 36 and 36a of two combustion chambers adjacent to an engine (in fact two parallel cylinders of an engine) lead to a common orifice 38 for communication with the intake pipe 25 common to the two cylinders.

This arrangement, which also applies to the exhaust ducts and orifices, makes it possible to reduce the number of outlets to be provided in the plug 1 and the cylinder head 32 which constitute as many zones of weakening of the mechanical resistance of these highly stressed members on the mechanical and thermal plans.

Returning to fig. 5, it is understood that during the rotation of the motor and the plug 1, the passage chamber formed by the suction duct 36 or all of the suction ducts 36-36a and 38, can come to trap the air relatively rich in fuel but cannot be swept away by the exhaust gases. The fuel contained in the suction passage 36 inside the valve 1 therefore remains in place until this passage 36 again reaches the suction position in order to inject it into the combustion chamber 2.

In the embodiment shown in Figures 7 to 9 and where the elements and bodies identical to those of the previous figures bear the same reference numbers, it is proposed to considerably reduce the fuel richness at the end of the suction period. To this end, the intake channel 25 shown in cross section in FIG. 8 and in longitudinal section in FIG. 9, comprises two auxiliary passages 39 and 40 for supplying a fuel-rich mixture such as an air-petrol emulsion obtained by injecting petrol using an injector 31 (conduit 39 in FIG. 9 ) or by an emulsion carburetor 41 (line 40 in fig. 9). When using petrol injection, a single auxiliary duct 39 is sufficient to ensure the correct metering of the fuel.

In this embodiment, as seen in the section of FIG. 8, during the rotation of the plug 1 during the intake phase of the four-stroke engine, the auxiliary conduits 39 and 40 are closed before the enlarged part 25a of the conduit 25 is so and the air sucked in at the end d suction on the large section 25a does not contain fuel and sweeps the passage chamber 27 delimited by the notch 24 to deplete it of almost all the liquid fuel deposited on its walls, so that when this passage chamber is through which the exhaust gases pass, these entrain only a minute quantity of fuel thus unused towards the exhaust pipe 26.

Figures 10 and 11 illustrate the mounting of a supply member connecting the combustion chamber 2 to the outside such as a spark plug 42 used when the heat engine is an internal combustion engine with controlled ignition. In the case of a fuel injection engine such as a diesel cycle engine, the spark plug 42 may be replaced by a fuel injector or a glow plug. Elements and bodies identical to those of the preceding figures, of course, have the same reference numbers.

If we refer to fig. 10, it can be seen that the spark plug 42 is screwed into a thread 43 formed through a thin wall area 44 of the cylinder head 32 of the engine, so that its electrodes 45 (connected to ground) and 46 protrude slightly from the interior of the combustion chamber 2. When using an engine with a high compression ratio, most of the combustion chamber in the vicinity of the top dead center of the piston (not shown) is constituted by the passage 5 of relatively large dimension formed in the sealing ring 6. When the spark plug 42 is placed in the position shown in FIG. 10, the fuel mixture is ignited relatively poorly because it does not start in a central position relative to the main volume of the combustion chamber at top dead center.

Fig. 11 illustrates in section an arrangement of the spark plug 42 (or where appropriate of a fuel injector or of a heating plug) which overcomes the drawbacks of the mounting solution shown in FIG. 10. The sealing ring 6 comprises between two supply passages 19 a thread 43 for receiving the end portion or base 47 of the spark plug 42 which, in the sealed mounting position through this thread crossing the cross section of the ring 6, projects by its electrodes 45 and 46 inside the passage 5 in the vicinity of the wall but substantially at the center of the main combustion chamber formed by this passage 5.

The spark plug rod 48 which constitutes the part adjacent to the base 47 crosses with play a relatively narrow passage 49 formed through the wall of the cylinder head 32. The passage 49 is connected to the outside by a bore 50 of larger diameter forming a annular chamber 51 into which the outlet pipe 16 opens. In order to close off the annular chamber 51, an elastic annular seal 53 is interposed between the wall of the bore 50 and the cylindrical insulator 52 of the outlet terminal 54 of the candle 42.

When the engine is running, a large flow of oil, preferably refrigerated beforehand, is brought in through line 13 and pressurizes the annular distribution chamber 14 to make it flow, via the inlet passages 19 , a low flow of lubricating oil in the interface e between the rotary plug 1 is the sealing surface 22 of the ring 6. At the same time, a greater flow of oil flows from the chamber 14 to the chamber 51 via the narrow passage 49. This oil flow, which is then evacuated to the tarpaulin, cools the ring 6 and the spark plug 42 by acting very effectively in the vicinity of the hottest part constituted by the base 47 and the electrodes. The position of the ring 6, relative to the rotary plug 1, is likely to vary in service as a result of the expansion of the ring 6, variable axial and radial pressure forces on this ring 6 and especially wear progressive sealing surface 22 of this ring in rubbing contact with the surface 8 of the rotor 1, this wear varying lejeu i. The instantaneous (at each explosion) and progressive movements of the ring 6 do not disturb the sealing of the chamber 51 and the position of the spark plug in the cylinder head 32 thanks, on the one hand, to the play in the passage 49 and avoiding any contact between the cylinder head 32 and the spark plug rod 48 and, on the other hand, the elasticity of the annular seal 53 preferably produced in one elastomeric material. Note that if we apply the embodiment of FIG. 11 to a diesel engine, the fuel injector could advantageously be cooled while the glow plug should not be or should be as little as possible, which is achievable by placing it in an insulating envelope.

The mounting device assembly system shown in FIG. 11 carries out a mechanical and vibratory decoupling between, on the one hand the sealing ring 6 which delimits most of the combustion chamber at the top dead center of the piston and, on the other hand, the cylinder head 32. Thanks to the properties damping the elastomer of the seal 53 and the annular seals 17 and 18, not only the possible vibrations of the ring 6 can not be transmitted to the cylinder head and vice versa but, in addition, these vibrations are damped at their frequency critical by the large mass of elastomer of the joint 53.

For reasons of simplification, it is of course possible to mount the spark plug 42 on the thread 43 of the ring 6 outside the refrigerant circuit passing through the annular chamber 14. For this, it suffices that the chamber 14 is, by example, placed near the upper end (in the drawing) of the ring 6 and in the vicinity of the interface e, the spark plug base 47 being placed either in the vicinity of the middle of the height of the ring 6 , which is closer to combustion chamber 2.

Claims (13)

1. Device for controlling the flow of the gas issuing from and flowing into the combustion chamber (2) of an internal combustion engine, constituted by a rotative valve cock or rotor (1) comprising at least one inner channel (3) or a lateral cut (24) defining transverse exhaust or inlet flow passages, respectively, a passage (5) directly connected to the combustion chamber (2), said valve cock (1) being enclosed in a transverse bore (4) into which opens the orifice of said passage formed in a sealing ring (6) which is placed in a bore (7) wherein it slides, said sealing ring (6) being applied onto the rotor (1) by a continuous contact surface (22) around the orifice of said passage (5) under the effect of the pressure prevailing within said combustion chamber (2) and surrounded by one or more sealing elements (11) such as sealing segments, while being provided with injection means (19, 23) for injecting oil onto said valve cock (1), characterized in that said sealing ring (6) is crossed through, at least at its periphery, by a pressure oil circuit (13, 14, 16) directed toward the oil collector and adapted to cool said ring (6), and in that said injection means (19, 32) which are connected to said oil circuit (13, 14, 16) cross axially at least a portion of the annular section of said ring (6) and open into an uninterrupted annular distributing groove (21) provided within the continuous contact surface (22) defined on a strip of small width along the general intersecting line of two cylinders, while opening at the interface (e) existing between said contact surface (22) and the outer surface (8) of said rotor (1).

2. Device according to claim 1, characterized in that said fluid injection means are constituted, on the one hand, by an annular oil inlet and circulating chamber (14) delimited between the periphery of the sealing ring (6) and its bore (7) and limited axially at each end by a seal (17, 18) interposed between the outer surface of the sealing ring and the bore (7) and, on the other hand, by at least one inlet passage (19) having an outlet orifice that opens at said interface (e) between the continuous sealing surface (22) and the outer surface (8) of said valve cock (1), and in that at least one flame sealing segment (11) is interposed between, on the one hand, said sealing ring (6) and its bore (7) and, on the other hand, said seal (17) located on the side of the combustion chamber (2).

3. Device according to claim 2, characterized in that the annular inlet chamber (14) is crossed through by a high rate pressure oil flow directed through an outlet conduit (16) toward another organ to be lubricated or toward the oil outlet.

4. Device according to any one of claims 2 and 3, characterized in that an end portion (45, 46, 47) of at least one organ for feeding one of the combustion elements, such as a sparking-plug (42) for a motor with controlled ignition, or an injector and/or a heating plug for a Diesel engine tightly extends through the cross-section of the sealing ring (6) and opens into the passage (5) which is connected to the combustion chamber, and in that the portion (48) adjacent to said end portion is mounted with an annular clearance in an inlet passage (49) directing said combustion element outwardly, said inlet passage (49) being connected to the annular fluid inlet chamber (14).

5. Device according to claim 4, characterized in that the passage (49) determining said annular clearance is crossed through by a flow of the fluid introduced into said annular fluid inlet chamber (14).

6. Device according to claim 5, characterized in that said passage (49) determining said annular clearance extends outwardly in the form of an enlar- gened annular chamber (52) which is closed by an elastic annular seal (53) interposed between the inlet organ (42) and the inner wall (50) of said chamber (51) and delimiting a cooling chamber (14, 19, 51) through which passes said fluid flow.

7. Device according to any one of claims 1 to 6, applied to a combustion motor, wherein the rotor (1) is used at the same time for controlling the motor exhaust and the inlet of the fuel-plus-air mixture into the combustion chamber, characterized in that means for scraping the fluid lubricant injected at the interface (e) are arranged about the inlet orifice connecting the rotor (1) to the combustion air and fuel mixture inlet of the motor, said scraping means being constituted by an inlet sealing ring (29) provided at the periphery of said inlet orifice and continuously bearing on the outer surface (8) of said rotor (1), said scraping means being adapted to isolate the inside of the inlet orifice with respect to the interface between said valve cock (1) and its bore, so as to limit the amount of oil carried along by the liquid fuel at the surface (8) of the rotating valve cock (1).

8. Device according to claim 7, characterized in that the sealing ring (29) is made, on the one hand, of a soft material having satisfactory friction properties with respect to the surface of said valve cock, such as plastic material, and is, on the other hand, continuously pushed onto the surface of said valve cock under the effect of the substantially constant pressure of a spring (30).

9. Device according to any one of claims 1 to 8, characterized in that said valve cock (1) comprises two separate inlet and exhaust passages (36, 37), respectively, which are adapted to open successively, both of them, through the rotation of the valve cock (1), on said sealing ring (6), on the side of the combustion chamber (2), and, on the side opposite to the combustion chamber (2), into outlet orifices each one of which is offset along the axis of the valve cock (2) with respect to said sealing ring (6), so as to decrease the amount of fuel carried off at the surface of the valve cock, as well as the amount of fuel carried off at the inlet into said inlet passage (27) provided within said valve cock.

10. Device according to claim 9, characterized in that said separate inlet or exhaust passages (36, 37) for two adjacent combustion chambers are provided in said valve cock and open into an orifice (38) communicating with the inlet or the exhaust that is common to said two adjacent combustion chambers, so as to reduce the number of orifices required on the outer surface of said valve cock.

11. Device according to any one of claims 1 to 10, applied to a four-stroke combustion motor, characterized in that the inlet circuit of the combustion chamber (2) comprises means for cutting off the fuel in the air aspired into the combustion chamber prior to the termination the inlet process.

12. Device according to claim 11, characterized in that when the fuel is introduced by injection into the inlet air, said cutting-off means are constituted by completely cutting off the fuel injection well prior to the termination of the aspiration phase.

13. Device according to claim 11 or 12, characterized in that the cutting-off means are constituted by at least one auxiliary passage (39, 40) for air with a high fuel content, said passage being provided in the valve cock (1) and the head (32) of the combustion chamber and opening at the interface between the rotor (1) and its bore (4) into an orifice which is sealed by the rotation of the rotor (1 ) prior to the sealing of the main inlet opening(s) (25).

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