FR2574474A1 - TWO-STROKE ENGINE - Google Patents

Abstract

The alternating motion of the pistons of said engine is transformed into a rotary motion by means of rollers (37) which follow the profile of the curved groove (43). The pistons describe a helical motion. Blocks (38) circulate in the axial ports (39) of the ring (40) and drive the latter with a rotary motion. The pistons have their bottom turned towards the crankcase. A space (41) necessary to the housig of the piston at its top dead center causes the airplug phenomenon to appear thereby enabling a gas sealing without the use of rings. The volume of the passage ways (45) represents an air reserve which adds an oxygen supplement to the ignited fuel. The volume of injected fuel may be a function of the volume of the primary combustion chamber.

Description

TWO-STROKE ENGINE
The present invention relates to a reciprocating piston engine of the two-stroke supercharged type with direct injection producing mechanical energy. The first claim gives a concise description.

 The most common motors use the embie.llage to transform the reciprocating movement into rotary movement.

 The linkage is heavy and bulky. It requires sophisticated means to form a more or less well-balanced whole.

 French Patent No. 1,562,381 proposes a movement transformation system comprising at least one crank pin secured to the piston, which circulates in a cam with an endless profile, together ensuring a functional connection between the reciprocating movement of the pistons and rotational movement. The crankpin (18) passes through a slot (16) formed in the cylinder block (21).

 The major drawback of this system is that this slot is not arranged in an element which can be immobilized or set in motion independently of the cylinders and / or of the pistons. FIGS. 18 et seq. Show us what this disadvantage can have as consequences with regard to the complexity of the engine.

 The motor according to the invention makes it possible to avoid these drawbacks. I1 comprises a ring (27) independent of the cylinders (24), see FIG. 1.

 Because the reciprocating movement of the pistons is transformed into rotary movement in an engine and vice versa at start-up or in a pump by rollers (10) which follow the profile of the curved groove (26). All the pistons, the support and their accessories describe a heli-cotidal movement. The rollers (10) pivot around axes (11) integral with the support (9). Rollers (12) pivot in turn around the rollers (10) to come and go in rectangular axial slots (13 and 14) arranged in a ring (27) appended to the pinions (8 and 16) with opposite inclined teeth. The ring (27) is mounted on needle bearings (15).

It can only move in a rotating direction. It is centered. axially by the rings (28) and by the pinions (8 and 16). The conversion of the movement and the transmission of the power is done directly at the height of the rollers. The ring (27 functions as a spacer for the support See also figure 2).

 this engine is further characterized by pistons which are inverted with their bottom returned to the casing, hence better cooling and the possibility of accessing a gas-tight seal without segment. The pistons are directly cooled by a liquid, most likely oil, which will circulate in the chambers (18). Each time the pistons reach their respective Top Dead Center, the liquid will lick the bottoms of the pistons before arriving inside the movement transformer system which it can lubricate. Oil overflows (29) will be arranged on the periphery of the rings (28) for the flow of oil after it has lubricated the bearings (15). A seal (6) will prevent the oil from passing into the cylinder. As the piston turns on its axis by the effect of the helical movement, it will not always be the same area of the skirt which will be exposed on the side of the exhaust , hence a regular distribution of the thermal zones on the periphery of the skirt.

 The cylinder head (22) is housed in the piston. Two effects then occur: a) the engine block is narrower; b) a space (20) necessary for housing the piston with its PRM and of a value of approximately 10 to 15% of the volume of the displacement reveals the phenomenon of the air plug, because this air is also compressed in the measurement where the piston moves towards its PM} I. The faster the motor oscillates, the more effective the seal will be because the air in the cap does not have time to leak. The tightness is explained by the fact that the air in the cylinder, before it can leak, must first eliminate the air plug.

In addition, the escape route is twice that in a conventional engine where the gases encounter no natural obstacle. moreover, most of the possible leaks are recovered in the air reserve (23).

The calculation of the volume of air admitted in (4) by a charger can take this into account.

The end of the skirt may have a shape (31) which will influence the efficiency of the air plug by forcing the air from the plug to join the air contained in the piston. The variation in the length of the skirt at this location varies the opening time of the lights.

 The cylinder head has two explosion chambers separated by a body (32) of refractory and calorific material, intended to heat the air and give it movement through pipes (33) to obtain maximum turbulence. If the first combustion chamber (36) has a volume corresponding to approximately 70% of the total volume of the dead spaces, the second (30) will have a volume of 30% of this total volume. If therefore by way of example, the first chamber receives an amount of 70% of the fuel necessary to make the 100% in a cylinder with a single combustion or precombustion chamber, the fuel / air mixture will be normal with respect to the first chamber of 70%, but poor compared to the 100% named above, which represents a fuel saving. The second combustion chamber contains a volume of compressed air which adds extra oxygen to the ignited fuel. The combustion intensifies.

It is only after this secondary combustion that the ignited mixture reaches the piston or the combustion ends. A projection (17) temporarily limits the passage of the ignited gases, but a narrowing (7) which widens as the piston leaves its TDC, allows them to pass through the piston. After sweeping, during the ascent of the piston towards its PRM, during compression, the fresh air acts easily in the explosion chambers. The intensification of combustion through the secondary combustion chamber must give rise to complete combustion. The cylinder head (22) will have a part (19) which will function as a deflector. It will be cooled by a liquid liquid which will be admitted through the orifice (21) and discharged through the orifice (13.

 The heating boeagie will be located in (2), but it can be removed to incorporate a heating element in the heating body (32). The latter may have one or more protrusions (5) to activate the heat rise of the air. The fuel injector located at (3) and the protuberance (5) can be arranged so that the fuel is injected against or towards the protuberance to activate the spraying and stirring and promote combustion.

 The cylinder (24) and the frame (25) will have a common chamber (35) which will cool the exhaust (34) with a liquid.

The curved groove (26) may have a shape that meets the criteria defined by the goal. Here it is arranged between two identical rings (28) which can form one, The two rings (28) can
other fixed to the frame (25) using a cap and screws.

 A third mounting hole comparable to that intended to receive the glow plug (2) can be provided to receive an air or oxygen injector for the purpose of sweeping the combustion chambers.

The injection would take place at the opening of the exhaust lights.

 The ring (27) can be fixed and the ring (28) movable; it is she who would carry the pinions (8 and 16).

 Gas tightness can be supplemented by segments arranged between the interior of the piston and the cylinder head or between the exterior of the piston and the cylinder.

 The pistons and the support can Other made in a single piece, but by fitting an appropriate fixing of the rollers, - see figure 4.

 The chambers (18) can be closed to make separate circuits by extending the skirt of the pistons.

 The motion converter assembly can be supplemented by conventional tones, the cylinder head (22) coming from outside the cylinder (24).

You can also use a cylinder head with a single combustion or pre-combustion chamber.

 The projection (17) can be omitted, but the passage of the gases should be done by invariable size pipes.

 The projection (17) can also be extended as far as the first explosion chamber (36). It would have a shape comparable to that of the protuberance (5) which it would remove.

The edge or the skirt of the piston which is housed in the space (20) may have a profiled shape allowing it to open and close the intake and the exhaust,
The curved groove may have a profile which would make it possible to use cylindrical rollers, but the predominant advantage of rollers and grooves with trapezoidal profiles lies in the fact that the adjustment of the play is made with greater precision and simplicity.

 The rollers (12) can be replaced by sliding blocks which can possibly be integral with the support (9).

 Figure 2 shows a radial section of the engine. We see that the motion converter is built with three rollers, but we can also design one, or a pump, or a compressor, or another machine having fewer or more rollers.

 An engine can be designed whose bottom of the pistons serves as an air pump. The piston would be mounted on a support (9) with tubular section, the pump would be arranged between the pinions (8 and 16) and the chambers (18).

 The rings (28) could be replaced by a cam along which rollers (10) would circulate; there would be as many on each side of the cam, but this construction would increase. substantially the mass of inertia of the support (9) which should carry twice as many rollers.

 The cylinder head (22) could be cooled by a cooling element immersed in the liquid of the hermetically sealed cylinder head. The heat of the exhaust gases could be used to pressurize the coolant fluid.

 One could fill the cylinder head (22) with a fluid which would absorb heat to pass and remain in a state other than its natural state.

 FIG. 3 represents a partial development of the rings (27 and 28) making it possible to see the movement of the rollers (10 and 12) in their respective grooves.

 Figures 4 and 5 show a practical application of this motor developed from a sinusoSdale groove based on a circumferential displacement equivalent to the axial displacement.

 The central ring attached to a pinion is carried by bearings (42) which can be designed in lead bronze. It finds support points against the thrust washers (44). The bearings and stops can be replaced by ball, roller or needle bearings.

 The heating element, easily interchangeable, has a narrowing here, but we can give it a shape that best meets the needs of the moment.

 The cylinder head has passages (45) for intake and exhaust.

Their volume may correspond to the air reserve of the second explosion chamber, but the secondary combustion will take place in the piston.

It will be noted that the cylinder head remains fitted into the piston. The primary combustion chamber can be connected to the passages (45) by pipes to reduce the total combustion time.

 The rollers or rollers may have an angle of inclination corresponding to the average development of the curved groove, see Figure 5.

 We can also build an engine, where for each group of two cylinders, the pistons are at the same time either at TDC, or at PMB, or at the same point between the two PM. This can be done by giving each piston its own support and its own accessories, but by having twice as many axial lights in the inner ring. Assuming that each piston is carried by three rollers, - we would have 6 axial lights arranged at 600 from each other. If the left piston support occupies the lights at 00, 1200 and 2400, the right piston support will occupy the lights at 600 1800 and 3000. The supports will therefore be offset by 600 relative to each other, will circulate in the same curved groove, but in their respective axial lights. The reciprocating movement of one piston will thus always be opposite to that of the other piston.

 The outside of the inner ring or the inside of the outer ring or the two named faces can be uniformly covered with a material serving as a plain bearing.

 By locating the first combustion chamber entirely or partially outside the joint plane of the cylinder head and the cylinder, it is possible to develop a valve engine s, these being placed on a plane parallel to the joint plane of the cylinder head, they would have their seat in the primary combustion chamber and would be actuated by one or more camshafts built in a plane parallel to the axis of the pistons.

 The jacket can be designed to function as an intake and exhaust lights control drawer. In this case, the engine could function as a four-stroke engine.

 A cylindrical accessory could be mounted on the inner ring to fulfill the role of light control drawer.

 The injection could be done some time before top dead center, while a spark plug would ensure ignition, see Figure 4, left cylinder, which would have the advantages of being able to inject at lower pressures and avoid misfires.

 We could equip the cylinder head with a shirt, which would facilitate foundry work. The passages (45) could be part of this shirt.

 It should be understood that the engine does not necessarily have to have an even number of cylinders. We can very well build one counting only one cylinder, or build one counting an odd number of cylinders.

Claims (10)

1- Direct injection supercharged two-stroke reciprocating piston engine producing mechanical energy without the intervention of crankshaft, based on a process analogous to that revealed by French patent no 1,652,381, which proposes a system of transformation of movement comprising at least one crank pin (8) integral with the piston (3), circulating in a groove (18) ensuring together a functional link between the reciprocating movement of the piston (s) and the rotary movement, the crank pin (8) passing through a slot (16) formed in the cylinder block (21), but characterized in that the ring (27) of Figure 1 is independent of the cylinders (24) the reciprocating movement of the pistons being transformed in rotary movement and vice versa by rollers (10) following the profile of the curved groove (26), all the pistons, the support and their accessories describing a helical movement, rollers (123 grouped with the rollers ( îo) coming and going in axial slots (34) arranged in the ring (27) annexed to the pinions (8 and 16) drive it in a rotary movement. The pistons have their bottoms returned to the crankcase. They are cooled by a liquid arriving in the chambers (18). A seal (6) prevents this liquid from passing into the cylinder (24). A space (20) necessary for housing the piston at its top dead center reveals the phenomenon of the air plug which allows access to a gas seal without segment, because the air contained in the space (20) is also compressed. insofar as the piston moves towards its PMHI, the end of the 3upe (31) can have a shape having a positive influence on the efficiency of the air plug by forcing the air in the plug to decrease to the air contained in the piston. the cylinder head- (22) housed in the piston has two combustion chambers (30 and 36), separated by a heating body (32) intended to heat the air and give it maximum turbulence by means of pipes (33). the volume of fuel injected is a function of the volume of compressed air in the first chamber (36), the second (39) adding a supplement of oxygen to the ignited fuel to complete the combustion in order to obtain complete combustion. A projection (17) temporarily limits the passage of the ignited gases when the piston is at its TDC, but opens a large passage to the frass air when the piston is at its pMB the cylinder head (22) has a part (l9) which works like a deflector.  2- Engine, according to a preceding claim characterized in that the gas tightness is supplemented by segments arranged between the inside of the pistons and the outside of the cylinder heads (22).  3- Engine according to one of the preceding claims, characterized by cylinder heads having only one combustion or pre-combustion chamber.  4- Engines according to one of the preceding claims, characterized by pistons, the skirt or the edge of the skirt which comes to nest in the space (20) has a profiled shape allowing it to open and close the intake and the 'exhaust.  5- Motor according to one of the preceding claims, characterized in that the bottom of the pistons serves as an air pump, the latter being arranged between the pinions and the chambers, on one side (18 and 8); from the lair (16 and 18).  6- Motor according to one of the preceding claims, characterized in that the rings (28) are replaced by a cam on each side of the lacquer as many rollers (10) would circulate.  7- Motor according to -7ne of the preceding claims, characterized by a ring (40) carried by bearings (42) and centered axially by stops (44).  8- Engine, according to one of the preceding claims, characterized by a cylinder head which remains fitted in the piston, but which has passages (45) for the intake and the exhaust, the volume of these passages possibly forming a chamber volume. secondary combustion, forming an a-r reserve to increase the combustion rate.  9- Motor, according to one of the preceding claims, characterized by pistons each having their own support and their own accessories sliding in deE respective lights offset by half of the incoming in degrees of the rollers of each support, but circulating in the same groove curve so that the reciprocating movement of one piston is always opposite to that of the other piston in the same group of two cylinders.  10- Motor, according to one of the preceding claims, characterized by a cylindrical accessory mounted on the inner ring to fill the ralle of light control drawer.