EP1355050A1 - Internal combustion engine - Google Patents

Abstract

The internal combustion engine cylinder includes one piston mounted conventionally, linked to a crank shaft, and a second piston mounted within the same cylinder. This piston is supported on a tubular shaft, extending through the closed end of the cylinder. The second piston is controlled by a solenoid, and is used to assist in the complete removal of exhaust gases from the cylinder after combustion. The internal combustion engine includes a driving piston (2) associated with a crank mechanism, and a second piston (3) moving within the same cylinder, solidly attached to the end of a tubular element (4) which passes through the end of the cylinder opposite the crank mechanism. A variable volume is defined between the two piston (2,3). The fuel inlet system is associated with the tube (4) with an aperture (4c) adjacent to the second piston (3). A plug (8) is provided for ignition and a valve (6,7) for removal of exhaust gases. The tubular element (4) extends beyond the end of the cylinder, and is linked to a solenoid (11).

Description

The present invention relates to a combustion engine internal comprising at least one cylindrical space of which the volume is a function of the axial position of a piston motor associated with a crank rod system, this space cylindrical containing a second piston, integral with a end of an axial tubular element, a variable volume formed between said pistons, means for admitting a combustible mixture associated with said axial tubular element, provided with at least one lateral opening, adjacent to said second piston, means for igniting this combustible mixture and means for the evacuation of the burnt gases.

The advantages and disadvantages of combustion engines internal in which the combustible mixture is compressed in a cylinder by a reciprocating piston associated with a crank rod system are well known. A large number of alternative solutions have been proposed to remedy the disadvantages, but for the most part we returns to the reciprocating piston engine associated with a system crank rod to which we constantly bring new improvements. This is how we have already proposed, with a view to improve engine performance at high speed supercharging the mixture of combustible gases, we have also proposed electronic ignition systems as well as quantity of special provisions to make these engines more efficient and less polluting.

WO 98/26166 has already proposed a motor comprising a cylinder containing two pistons, one of which is a movable piston, integral with a crank rod system, while that the other is a fixed piston secured to a conduit tubular coaxial with the cylindrical combustion chamber. The end of this duct located near the fixed piston is open, while its other end is connected to a fuel mixture supply. The combustion chamber is formed between the face of the movable piston located at the exterior of an intermediate chamber formed between the two pistons and the cylinder which encloses them. Initially time, when communication is interrupted between the intermediate chamber and the combustion chamber, the mixture fuel is compressed in the combustion chamber while the volume of the intermediate chamber increases, creating a depression which causes the arrival of the mixture fuel in this intermediate chamber. The explosion of compressed mixture in the combustion chamber occurs in end of stroke of the movable piston. At first, the fuel mixture drawn into the intermediate chamber is compressed by the movable piston, until it sets in communication the two rooms, at the same time that it clears an exhaust port formed in the wall of the cylinder, so that the burnt gas escapes, simultaneously with the transfer of the combustible mixture of the intermediate chamber in the combustion chamber. So this engine works like a two-stroke engine with an annular movable piston and supplied by a coaxial conduit to the cylinder.

Although this engine has two pistons, the exhaust burnt gas from the combustion chamber is not improved compared to two- or four-stroke engines. At on the contrary, this engine has the same disadvantages in this respect than two-stroke engines, i.e. in particular of a polluting engine, necessarily rejecting a certain proportion of unburned gases since these enter the combustion chamber during evacuation burnt gases.

The aim of the present invention is in particular to remedy, at least in part, to the disadvantages of internal combustion.

To this end, the subject of this invention is a motor with internal combustion as defined by claim 1.

The engine object of the invention has many advantages, most of which will be mentioned after the description detail of the invention, to the extent that they will be better understood following this description. We can however already cite the fact that the double engine independent pistons, according to the present invention, allows to obtain a practically total evacuation of the burnt gases leading to optimal explosion conditions and reducing pollution from exhaust gases.

The attached drawing illustrates, very schematically and to as an example, two forms of execution and a variant of the motor object of the present invention.

Figure 1 is an axial sectional view of a cylinder engine according to the first embodiment representing mobile organs, participating in the explosion process of a combustible mixture, in a first corresponding position at the start of an explosion cycle;

Figure 2 is a view similar to Figure 1, showing the moving parts in a second position of the explosion cycle;

Figure 3 is a view similar to Figure 1, in a third position of the explosion cycle;

Figure 4 is a view similar to Figure 1, in a fourth position of the explosion cycle;

Figure 5 is a view similar to Figure 1 in the final position of the explosion cycle;

Figure 6 is an axial sectional view of a cylinder motor according to the second embodiment representing mobile organs, participating in the explosion process of a combustible mixture, in a first corresponding position maximum compression of the fuel mixture;

Figure 7 is a view similar to Figure 6 in the explosion phase;

Figure 8 is a view similar to Figure 6 in an expansion phase of the fuel mixture after the explosion;

Figure 9 is a view similar to Figure 6 in a phase of exhaust of the burnt gases and suction of the gas mixture;

Figure 10 is a view similar to Figure 6 in the maximum expansion position of the engine piston;

Figure 11 is a view similar to Figure 6 in the position of total evacuation of the burnt gases;

Figure 12 is a view similar to Figure 6 at during the transfer of the combustible mixture from the space between the two pistons in the combustion chamber;

figure 13 is a diagram representing displacements of the different organs of a combustion cylinder in function of time during an explosion cycle, relative to the embodiment of Figures 1 to 5;

Figure 14 is a diagram similar to that of Figure 13, relating to the second embodiment.

Only a combustion cylinder and moving parts associated with it are represented in the figures of drawing. The classic elements connecting rod crank to transform the reciprocating movement of the rotating engine piston are not shown, except for a portion of connecting rod B associated with the engine piston, since they are known from skilled in the art and are not necessary for understanding of the invention, which essentially relates to the combustion cylinder part containing two movable pistons with independent displacements from each other.

The engine part illustrated in FIG. 1 comprises a cylinder 1 in which two pistons slide, a piston motor 2, the external face of which is associated with the connecting rod B and a second piston 3. The face of this second piston 3, located at outside the cylindrical space formed between it and the motor piston 2, is integral with an axial tubular rod 4 sliding mounted inside a shutter 5 of form also tubular, itself slidably mounted in part central tubular 1b formed in the bottom of the cylinder 1. The bottom of this cylinder 1 has an exhaust opening 6 controlled by a valve 7 and a spark plug ignition 8.

The tubular rod 4 of the second piston 3, called the piston sweeper 3, located at the opposite end to that which is secured to this sweeping piston 3 ends in a part elongated 4a in the form of a bar or tongue, of a material magnetic, engaged in a solenoid 9 connected to a power supply device controlled by a servo drive 10. This supply device 10 can also be connected to two other solenoids 11 and 12 in which are engaged respectively an elongated part 5a of material magnetic, integral with the tubular obturator 5 and a magnetic rod 7a integral with the valve 7. In a variant not shown, the valve 7 can also be operated by a conventional camshaft instead of being by the solenoid 12. The spark plug 8 can be supplied by this same servo-powered feeder 10.

A fuel mixture supply nozzle 13, formed, in a carburetor not shown, by a gas mixture of air and fuel, in which micro-droplets of fuel are dispersed, mounted in a fixed position inside the axial tubular part 4 mobile.

The sweeping piston 3 has a central opening 3a, preferably of frustoconical shape, which allows the conduit formed inside the axial tubular part 4 of communicate with the space between the two pistons 2 and 3.

Near the sweeping piston 3, side openings 4c pass through the axial tubular part 4 and are thus likely to communicate the part of the cylinder 1 located below the sweeping piston 3 and constituting the combustion chamber 15 with the space between the two pistons 2, 3 and constituting the intake anteroom fresh gases 14, as can be seen in particular in FIG. 4. These lateral openings 4c are checked by shutter 5, capable of closing them as illustrated by Figures 1 to 3 or open them as illustrated by Figures 4 and 5.

The internal face of the driving piston 2 has, in its center, a tapered plug 2a of shape complementary to the frustoconical opening 3a formed in the center of the sweeping piston 3, so that it closes this opening 3a when the two pistons 2, 3 meet, as illustrated by the Figures 1 and 5. An axial rod 2b projects from the center of this frustoconical plug 2a. This axial rod 2b is dimensioned to close the nozzle dispensing opening supply 13 when the piston 2 descends in the direction from the bottom of cylinder 1, as shown in Figure 3.

As we will realize during the description relating to the operation which will follow, the two pistons 2, 3 make it possible to delimit two chambers variable volumes, the fresh gas suction anteroom 14 (Figure 3) which has substantially the shape of a cylinder full and the combustion chamber 15 (FIG. 5) which is annular shape, since it is formed around the shutter tubular 5. Note also that the diameter of this central tubular part formed by the shutter 5 and of the tubular rod 4 of the sweeping piston 3 can be increased, so that the volume ratio between the anteroom fresh gas intake 14 and combustion chamber 15 be relatively large, with the advantages that will be explained thereafter.

In addition to the exhaust opening 6, the side wall of the cylinder 1 still has pressure relief lights 1a, located just below the sweeping piston 3 in the maximum expansion position illustrated in Figure 1.

We will follow the different operating phases of the internal combustion engine cylinder described above in during an explosion cycle, with reference to Figures 1 to 5, as well as in the diagram of FIG. 13, representing the movements of the main elements involved in the explosion cycle.

Position 0 of this diagram corresponds to the explosion of the compressed fuel mixture as illustrated in the figure 5. Following the expansion of the gases, following this explosion, the two pistons 2 and 3 applied one against the other are pushed into the maximum expansion position illustrated by Figure 1 and corresponding to 90 ° of the explosion cycle on the diagram in figure 13. During this movement, the shutter 5 follows the sweeping piston 3.

As soon as the two pistons 2, 3 have reached their position end of the expansion stroke, illustrated in Figure 1 and corresponding to 90 ° of the explosion cycle, the pressure in the combustion chamber 15 drops suddenly following the clearing of lights 1a by the sweeping piston 3. The shutter 5 accompanies this sweeping piston 3. As soon as the pressure of the combustion chamber dropped, the solenoid 9 acting on the elongated magnetic part 4a causes the sweeping piston 3 at a speed higher than that of the piston motor 2, so that it reaches the opposite end of travel, 90 ° of the explosion cycle before the engine piston 2 in connection kinematics with the crank rod system, as we see in the diagram in Figure 13.

During all this movement of the sweeping piston 3 in the direction valve 7, it is detached from its seat by the solenoid 12 acting on the rod 7a of the valve 7, allowing the complete evacuation of the burnt gases, since in end of stroke of the sweeping piston 3, the volume of the chamber combustion is zero or almost zero. The uprising of the valve 7 by solenoid 12 to clear the exhaust opening 6 does not require the solenoid 12 to exert a high force on rod 7a, since the interior of the chamber of combustion has been previously ported with the atmosphere by the release of lights 1a, so that the pressure inside the combustion chamber 15 can be greatly reduced.

As soon as the sweeping piston 3 leaves the driving piston 2, the conical opening 3a located at the end of the tubular rod 4 of the sweeping piston 3 is released, putting in communication the feed nozzle 13 with the space between the two pistons 2, 3 and which constitutes the anteroom 14 of the fresh gas. These fresh gases were sucked in after the depression generated following the increase in volume of the aforementioned anteroom, by the displacement of the piston sweeper 3 whose speed is higher than that of the piston engine 2, after maximum expansion of the combustion chamber 15, as can be seen in the diagram in the figure 13.

Arriving at the phase illustrated in Figure 3 and corresponding to half of the explosion cycle, valve 7 will close the exhaust opening 6, the tubular shutter 5 is lowered by the solenoid 11, to clear the openings side 4c and the sweeping piston is moved by the solenoid 9 towards the engine piston 2. During this displacement of the sweeping piston 3, the driving piston 2 continues its lowering, compressing the fresh gas at the same time as this is transferred from the anteroom 14 formed between the two pistons 2, 3 to the combustion chamber 15 through the openings lateral 4c.

From the start of this compression and transfer phase fresh gas, the axial rod 2b, integral with the piston engine 2, closes the outlet of the fresh gas nozzle 13, preventing the discharge of these gases to the carburetor (not shown) as illustrated in figure 4.

Once the sweeping piston 3 abuts against the piston engine 2, all fresh gas has been transferred from the anteroom feed 14 into the combustion chamber 15. When the driving piston 2 reaches its maximum compression position, the shutter 5 closes the side openings 4c (Figure 5) and the explosion is produced by the ignition of the spark plug 8, bringing the moving parts into the position shown in Figure 1 where a new cycle can start again.

Besides the fact that the sweeping piston 3 allows evacuation practically complete of the gases burnt as a result of each explosion, there are several other advantages from the internal combustion engine described above.

Insofar as the exhaust of the burnt gases is not no longer performed by the driving piston 2, but by the piston spillway 3, the volume of the combustion chamber 15, at maximum compression of fresh gases before explosion, can be increased, which corresponds to an increase of engine power.

The ratio between the volume of the suction anteroom 14 and the combustion chamber 15, or more exactly the ratio between the cylindrical surface of the anteroom 14 and the annular surface of the combustion chamber 15 allows to determine the pressure of the fresh gases in the chamber combustion before explosion. The smaller the internal diameter of the tubular part 4, 5 is large, the more this pressure is high for the same stroke of the engine piston 2, since the fresh gases drawn into the volume of the supply anteroom 14 are then transferred into the annular volume of the combustion chamber 15.

This allows in particular to reduce or even eliminate engine performance losses at high speed without requiring of turbo-compressor.

Since the engine piston is no longer used to evacuate the burnt gases, we can have an explosion every two times, without having the disadvantages of classic two-stroke engines. So we can have, for the same power, a motor half the size of a four-stroke engine, since the number of cylinders can to be halved.

Optimal evacuation of burnt gases allows an explosion better quality gases than in a four engine time. It also helps reduce pollution due to exhaust gas.

We will now refer to Figures 6 to 12 relating to the second embodiment.

The essential difference between this second form of execution and the first described above lies in the so that the driving piston 22 is here a bell piston whose the tubular part 22c constitutes the side wall of the antechamber of fresh gas 34 (Figure 9) and the combustion 35. The bottom of this combustion chamber 35 is formed by the fixed frame part 21 which carries the spark plug 28. This fixed part therefore no longer contains cylinder, the latter being formed by the tubular side wall 22c of the bell piston 22. This tubular part 22c of the bell piston 22 is slidably mounted along a wall lateral lateral 21c of the fixed part 21 of the motor which extends below the bottom of the combustion chamber 35. Exhaust lights 22d are provided through the tubular side wall 22c of the bell piston 22.

The other elements of this embodiment are practically the same and have the same functions as those of the first embodiment. The same reference numbers, increased by 20, have been used to designate the elements of the second embodiment which are comparable elements of the first embodiment.

Among the other differences between these two forms execution, we can mention the presence of 21d channels for circulating coolants in the wall of the fixed part 21 of the motor frame.

Another difference is that this second embodiment no longer requires a valve for the evacuation of the burnt gases, these being completely evacuated by the sweeping piston 23 through the lights exhaust 22d. Figure 11 shows the sweeping piston at the end of the stroke, corresponding to 180 ° of the explosion cycle illustrated by the diagram in Figure 14. This position of the sweeping piston 23 coincides with the closing exhaust lights 22d from the side wall 22c of the piston bell 22, so that all of the gases burned can be evacuated from the combustion chamber 35 without require valve.

The removal of the valves therefore entails that of the camshaft, which is a simplification notable compared to the first embodiment as well as compared to four-stroke engines.

Regarding the operation of this second form of execution, it differs from that of the first form in that the sweeping piston 23 leaves the piston 22, as soon as the exhaust lights 22d begin to open, as can be seen in the diagram in the Figure 14, while the driving piston 22 continues its movement sine up, opening the lights 22d exhaust maximum. As soon as the external face of the sweeping piston 23 reaches the upper edge of the lights exhaust 22d from the side wall 22c of the engine piston 22 (Figure 10), the two pistons descend together. The rest of the cycle corresponds to that of the first form execution.

Among the advantages not yet mentioned, there are still worth noting that the mixture of air and fuel being introduced into a feed anteroom 14, 34 before passing into the combustion chamber 15, 35, this transfer produces a homogeneous air-fuel mixture and improves the quality of combustion, contributing also to reduce pollution caused by gases burned.

Claims (7)

Internal combustion engine comprising at least one cylindrical space whose volume is a function of the axial position of a driving piston (2) associated with a crank rod system, this cylindrical space containing a second piston (3), integral with one end an axial tubular element (4), a variable volume (14) formed between said pistons (2), inlet means (3a) of a combustible mixture, associated with said axial tubular element (4), provided with at least one lateral opening (4c), adjacent to said second piston (3), means (8) for igniting this combustible mixture and means (la, 6, 22d) for discharging the burnt gases, characterized in that said axial tubular element (4) extends outside said variable volume (14) formed between said pistons (2, 3) and passes through said cylindrical space (15) in which are located said ignition means (8 ), a central opening (3a) of said second piston (3) communicating said element t tubular (4) with said variable volume (14), said tubular element (4) being associated with means for guiding (la) and axial displacement (4a, 9), a shutter (5) being associated with means for displacement (5a, 11), for opening and closing said lateral opening (4c), means for controlling (10) said displacement means (4a, 9), said driving piston (2) comprising means (2a) for closing the admission of said combustible mixture as well as the central opening (3a) of said second piston (3). The engine of claim 1, wherein said cylindrical space is provided in a fixed part (1) of the motor in which said pistons (2, 3) are slidably mounted. The engine of claim 1, wherein said cylindrical space is provided inside the wall tubular lateral (22c) of said engine piston (22) mounted sliding on a frame part (21). Motor according to claim 2, in which the wall of said fixed part (1), forming the side wall of said cylindrical space, has at least one opening (la) located adjacent to the face of said second piston (3) delimiting said combustion chamber (15) in the position where said second piston (3) defines the maximum volume of said combustion chamber (15). An engine according to claim 3, wherein said means for the evacuation of the burnt gases consist of at least one light (22d), formed in the side wall tubular (22c) of said drive piston (22) and arranged for put said combustion chamber (35) into communication with the atmosphere after the explosion of said combustible mixture, until the volume of said combustion chamber (35) is close to zero. Motor according to claim 4, wherein at at least a second opening (6) is formed in the wall of said fixed part (1) forming the bottom of said cylindrical space, this opening being controlled by a valve (7) connected to electromagnetic displacement means (7a, 12). Motor according to one of the preceding claims, wherein said moving means (4a, 9, 5a, 11) of said axial tubular element (4) respectively of said obturator (5) are electromagnetic actuation means.

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