FR3025251A1 - THERMAL MIXED MOTOR / COMPRESSED AIR - Google Patents

Abstract

The combined thermal / compressed air motor makes it possible to operate the same engine block in four-stroke thermal mode (m3), in four-stroke thermal mode with supply by compressed air (m1, 2), in compressed air mode. two times (m5), when braking, it is converted into a two-stroke compressor (m4). It comprises movable camshafts which can slide their axle carrying complex profile cams (A) making it possible to print to the intake (a) and exhaust (b) valves the movement required for the different modes, a mobile crankshaft ( v) connected to a movable intermediate shaft (i) connected itself to a fixed transmission shaft (t) that can modify the volume ratio of the combustion chamber between the high position and the low position of the piston, it increases the rate of Compressed air mode of the engine (Bm5) and compression ratio in compressor mode (Bm4), the compressed air is heated in a rising temperature gradient during its expansion (Cm5), which makes it possible to recover the heat released by the engine in thermal mode. The projection of water on the proximal part of the exhaust pipe increases the pressure of the compressed air, the cooling of the exhaust gases by the expansion of the compressed air makes it possible to condense a part of the projected water.

Description

1 The search for new sources of energy to power a vehicle is a hot topic. Similarly, the recovery of the kinetic energy of a vehicle under braking has led to many developments. The hybrid electric thermal solution was the first used, the mechanical solution by a flywheel was developed in motor racing. The latest development is the hybrid thermal compressed gas engine. At the same time, solutions using an alternative energy source and possibly combining the recovery of kinetic energy with braking are developed.

The compressed air motor and the electric motor have this advantage. The compressed air motor is converted into a compressor under braking. The electric motor is converted into a generator when braking. Only the electric motor was followed by an industrial development. Although it has many qualities like the ease of adjusting the power and a large power. Its main disadvantage is the presence of batteries whose weight / energy stored is low. The price of batteries is high, their life is limited. Batteries must be recycled and use rare and expensive raw materials. The electric vehicle is competitive only with state aids.

An additional advantage is the availability of the power source (electricity) but it is accompanied by a disadvantage which is the charging time of the electric batteries, which poses a problem during long trips. The compressed air engine has not been able to achieve industrial development despite its advantages. The cost of energy is low, the energy storage system has an unlimited life. The load that was originally designed as a domestic load is long, it could be fast from an external supply of compressed air. The essential reason for this failure is a power limit much lower than the power of a heat engine or an electric motor and insufficient autonomy. A large part of the energy stored in the form of compressed air is lost due to the cooling of the air during its expansion. The vehicle's range could only be increased by lightening the vehicle, which limits its use to urban use.

3025251 2 The thermal engine remains the main mode of motorization despite its low energy efficiency (most of the energy is converted into heat) and despite the fact that it uses a mainly fossil energy. It combines the advantage of easy power control with large power limits and easy storage of the power source. The proposed solution is a mixed engine that can operate in thermal mode and in compressed air mode. It combines the advantages of the heat engine, which is the ease of power control and high limiting power, and the advantages of the compressed air motor, which are the low cost of energy and the unlimited life of the storage system ( compressed air tank). It allows the recovery of kinetic energy during braking by converting the motor into a compressor. It has a last advantage which is the possibility of recovering the heat generated by the engine to heat the compressed air during its relaxation by giving the engine a property RET (recovery of thermal energy). The presented engine can function as a conventional four-stroke engine. It can operate in thermal mode with supply by compressed air at variable pressures (the intake phase is at positive pressure and provides energy to the vehicle). It can operate with compressed air in two-stroke mode. Finally, it is converted into a two-stroke compressor under braking. Thermal mode with or without compressed air supply is used for acceleration. The compressed air mode is used when the vehicle has reached cruising speed to maintain this speed.

The passage from one mode to another is ensured by a computer which is informed of the speed of the vehicle, of the force which the driver exerts on the acceleration control, of the engine temperature, of the pressure of the engine. compressed air and the state of fuel and compressed air reserves. It triggers the two-stroke compressed air mode if the engine temperature significantly increases the pressure of the compressed air to preserve the reserve of compressed air and if the power in compressed air mode is sufficient to maintain the speed of the vehicle or to ensure a low acceleration. The transition to the two-stroke compressor mode is triggered by the actuation of the brake control.

3 0 2 5 2 5 1 3 The conversion of the combustion engine into a combined thermal / compressed air engine is obtained by modifying three elements which are shown diagrammatically in FIG. 1. A camshaft carrying complex profile cams (1) opposes the valve tails a variable profile by the sliding of the camshaft on its axis. A profile allows operation in four-stroke thermal mode. A series of profiles allows operation in four-stroke thermal mode with compressed air supply at increasing pressures through early closure of the inlet valve, a This profile enables operation in two-stroke compressed air mode, and finally a profile converts the motor into a two-stroke braking compressor to reconstitute the compressed air supply. A movable crankshaft (2) makes it possible to increase the rate of expansion of the engine when it operates with compressed air by modifying the ratio of volumes of the combustion chamber between the time when the piston is in the up position and the time when the piston is in the down position. Likewise when braking when the engine is converted into a compressor, it increases and makes the compression ratio of the motor proportional to the force exerted on the brake control. Finally, the presence of a system of expansion of the compressed air in stages (3) accompanied by heating by the heat released by the engine in thermal mode gives the engine a property RET (recovery of thermal energy).

The compressed air stored in a main tank (1) is expanded by a first expander (3) and is reheated in a second tank (4) by the line leading the engine coolant to the radiator (5). After expansion by a second expander (7) it is further heated by circulating in air compartments contained in the cylinder blocks (12) and ends its warming by flowing in contact 25 and against the flow of exhaust gas in a duct. double wall exhaust (13) before being admitted into the engine by a third expander (14) whose opening is proportional to the force exerted on the acceleration control. As shown in FIG. 9A, the projection of water on the proximal portion of the exhaust duct (20) can be envisaged to further increase the pressure of the compressed air (sauna effect). The cooling of the exhaust gas at the end of the exhaust pipe by the expansion of the compressed air contained in the storage tank (1) would allow the condensation and the recovery of a part of the projected water but also From the water produced by the combustion and creating a closed circuit of water, a part of the pollutants (oils and fuel residues) would also be condensed, which would make the mixed engine a particularly clean engine. If the motor has two lines of cylinders, the two lines can be independent (Fig.

1Cb), one line can operate in thermal mode and the second in compressed air mode with a different speed of rotation. The line operating in thermal mode will heat the air of the line operating with compressed air. Each cylinder line has its own crankshaft (v) an intermediate shaft (i) and a transmission shaft (t) which by a gearing to develop several transmission couples transmits its movement to a shaft 10 common to both lines (tc) leading to the gearshift device. If the two rows of cylinders are not independent (Fig.

1Ca), the transmission shaft (t) can be common to both lines. The transmission shaft (t) is fixed, it transmits its movement by a pulley (pot) to the belt or the distribution chain (cd) of its line of cylinders (Fig.

1A).

The camshaft carrying complex profile cams (a) is detailed in FIGS. 2 and 3. It is driven by the transmission shaft of its line of cylinders (t). As shown in Figure 2 it slides on its axis and can be moved by the control of the operating mode of the engine (cmo) with a circular relief 20 (RCA) serving as a support to the operating mode control mechanism (cmo) ). It has at the pulley (poa) driven by the chain or the timing belt (cd) one or more reliefs (ra) inserted in one or more grooves (poar) through the pulley. the shaft (a) is integral with the pulley (poa) in the direction of rotation and can slide freely on its axis. The reliefs (ra) must maintain the synchronization between the crankshaft and the camshaft and compensate for the offset that is created when the crankshaft is raised. They are straight for the positions corresponding to the thermal operating modes (ra1), they are oblique (ra2) at the braking position to compensate for the offset which is created between the crankshaft and the transmission shaft when the crankshaft is raised. they are again right (ra3) at their end which corresponds to propulsion in two-stroke compressed air mode. The reliefs (ra) may be straight over their entire length, the reliefs of the cams will then be twisted in the braking position to compensate for the offset caused by the rise of the crankshaft.

Each cylinder line ideally has an intake camshaft and an exhaust camshaft carrying the complex profile cams. The sliding of the intake shaft and the exhaust shaft is synchronized, the mode of operation is determined by the profile that the two cams oppose the valve shanks. The intake shaft and the exhaust shaft carry at each cylinder a cam with a complex profile having roughly the shape of a bone and opposing the valve stem profile corresponding to the different modes of operation. The profiles of the two cams are shown in Figure 3.

The intake cam is shown at the top of Figure (A), the exhaust cam at the bottom of Figure (E). They are presented in longitudinal section at the top and bottom of the figure. Cross-sections at different levels show the profiles opposite to the valve tails in the various operating modes for the intake (exhaust) and exhaust valves ( e). The profile p3 allows operation in four-stroke thermal mode with supply by air at atmospheric pressure. The relief on the intake (AC) and exhaust cam (e) allow the opening of the intake valve during the lowering of the piston during the intake phase and the opening of the exhaust valve during the raising of the piston during the exhaust phase. The profiles p1 and p2 correspond to the thermal operating mode with compressed air supply. A relief allowing the opening of the intake cam (r) to be refined away from the position allowing the operation in four-stroke thermal mode with supply by air at atmospheric pressure (p3) allows an early closure of the intake valve even earlier than the cam is moved away from the four-stroke position with air supply at atmospheric pressure (p3) and the supply by compressed air to a increasing pressure from position p3 to position p1. The computer determines the position of the camshafts according to the air pressure measured at the inlet by a pressure sensor. The relief allowing the opening of the intake valve widens from left to right. On the left (pl) the inlet valve opens for a short time when the piston is still in the up position in the cylinder and begins its descent. If the engine is supplied with compressed air at a pressure close to atmospheric pressure multiplied by the compression ratio of the engine, the pressure at the end of the compression phase will be this same pressure. The intake phase will be active and will provide energy to the vehicle by the expansion of compressed air. The exhaust cam (e) allows the opening of the valve during any period of the rise of the piston during the exhaust phase. The thermal operation mode with compressed air supply is the mode where the engine delivers its maximum power, the power is all the more important that the pressure of the compressed air is important. The source of compressed air is the reserve of compressed air, a regulator controlled by the computer informed of the force exerted on the acceleration control of the vehicle controls the admission of compressed air to the engine. The pressure of the intake air is proportional to the force exerted on the acceleration control.

For both thermal operating modes the crankshaft is in the down position. In thermal mode with supply by compressed air the engine uses unheated compressed air in the cylinder block and in the exhaust pipe, this mode does not allow the recovery of thermal energy, an open pipe by a valve directs the compressed air directly to the engine (Fig.

8B).

The profile p5 corresponds to the two-stroke air motor operating mode. The crankshaft is in the up position, which increases the rate of expansion of the cylinders. The opening of the intake valve is limited to a short time when the piston is in the up position and begins its descent. To allow the two-stage mode of operation relief to open the inlet valve is doubled. The relief of the exhaust cam is doubled and allows the opening of the exhaust valve at each ascent of the piston. The high pressure differential between the intake line and the cylinder when the engine is in two-stroke compressed air mode will likely result in the need to reinforce the valve springs. Circular reliefs on the camshaft acting as a support for a reinforcement of the valve springs placed in front of the reliefs when the camshaft is in the two-stroke compressed air position would make it possible to reinforce the valve springs when the engine is in air mode 3025251 7 two-stroke tablet. The profile p4 corresponds to the mode of operation in two-stroke compressor during braking. The crankshaft is placed at a height proportional to the force exerted on the brake control, which renders the compression ratio and braking power proportional to the force exerted on the brake control. An obstruction of the exhaust and the opening of a compressed air tank or one of the tanks where the expansion of the compressed air used by the engine is performed makes it possible to recover the kinetic energy of the vehicle when braking by restoring the reserve of compressed air. The rise of the crankshaft creates an offset with the drive shaft, a proportional displacement of the camshaft compensates for the offset either by the fact that the camshaft relief (ra) sliding in its pulley (poa) are oblique (ra2) when the camshaft is in the braking position as shown in Figure 2, or by twisted reliefs on the cams in the braking position. The opposite profile to the intake valve (a) allows the opening of the valve at each descent of the piston, the profile opposite the exhaust valve (e) the opening of the exhaust valve at each ascent . The movable crankshaft and its lifting system is schematically shown in FIG. 4 in the low (A), intermediate (B) and high (C) positions, a more detailed view is shown in FIG. 5 in the down position (1) and high (2), Figure 6 shows the assembly of the elements of the mechanism. The crankshaft (v) is mechanically connected to a movable intermediate shaft (i), the movable intermediate shaft is connected to a transmission shaft (t) which is fixed. FIG. 5A shows in dotted line the trajectory of the various trees which are represented in solid lines in the low and high position. The line of cylinders is inclined to limit the weight exerted on the trees. The cylinders, the crankshaft (y) and the transmission shaft (t) are in the same axis. The crankshaft (v) has a rectilinear trajectory and moves away when it is mounted on the transmission shaft (t). The intermediate shaft (i) which maintains the mechanical connection between the crankshaft (y) and the transmission shaft (t) follows an arcuate trajectory centered on the axis of the transmission shaft (t). As shown in FIGS. 5C and 5D, the displacement of the movable shafts is ensured by fixed partitions (cf) and movable partitions (cm) traversed by the crankshaft shaft (av), the intermediate shaft (a1) and the transmission shaft (at). The fixed partitions (cf) have fixed grooves (rfi and rfv) in which the intermediate shaft (ai) and the crankshaft (av) move. The transmission shaft (at) is fixed to the fixed partition (cf). The groove containing the crankshaft (rfv) is a line passing through the axis of the drive shaft and the longitudinal axis of the cylinders (Fig. 4) following the crankshaft path from its low position to its high position . The groove containing the intermediate shaft (rfi) has a circular arc shape centered on the axis of the transmission shaft (at) on the portion of the groove (rfi) along the path of the intermediate shaft of its low position (Fig.

5C1) at its high position (Fig.

5C2). The movable partitions (cm) ensure by their movement the rise of the crankshaft (y) and maintain the connection between the intermediate shaft (i) and the transmission shaft (t). The movable partitions (cm) pivot on the axis of the transmission shaft (at) and have a roughly triangular shape with a point attached to the axis of the transmission shaft (at). The opposite side of the tip has the shape of a circular arc centered on the axis of the transmission shaft (at). She carries a rack (c) in contact with a pinion (pg). The rotation of the pinion (pg) causes the pivoting of the partition and the rise of the crankshaft. The gears (pg) are placed on an axis (ag) and each movable partition (cm) is in contact by its rack (c) with a pinion (pg). The rotation of the pin 20 (ag) carrying the pinions (pg) is triggered by the control of the operating mode of the engine. The crankshaft is in the low position for all thermal operating modes (without or with compressed air supply) and in the high position in two-stroke compressed air mode. In the two-stroke braking compressor mode, the computer which controls the crankshaft rise ensures progressive braking by placing the crankshaft at a height proportional to the force exerted on the brake control by the rotation of the axle (ag). carrying the gables (pg). The braking force will be progressive and proportional to the compression ratio of the engine determined by the crankshaft height (fig.

10B4).

The movable partition (cm) also has two grooves as shown in FIG. 5D. An oblique groove (rmv) ensures the displacement of the crankshaft, the crankshaft is placed at the intersection of the groove of the fixed partition (rfv) and the groove of the movable partition (rmv). The groove of the movable partition (rmv) is shown in FIG. 5D. The beginning of the groove has an oblique trajectory, the pivoting of the movable partition first places the crank shaft (av) slightly above its high position. The end of the groove is in an arc and is slightly closer to its termination of the axis of the drive shaft. In the high position (D2) the crankshaft 5 rests on the movable partition (cm) in a stable position at the end of the movable groove (rmv) by its own weight. The thrust of the pistons is exerted on the movable partitions (cm) which rest on the transmission shaft (at), these two elements must be particularly rigid. Movable bulkheads (cm) can be attached to the drive shaft (at) by bearings.

The second groove (rmi) allows the displacement of the intermediate shaft, it is in the shape of a circular arc centered on the axis of the transmission shaft (at) as the groove of the fixed partition (rfi). The maintenance of the mechanical connection between the crank shaft (av) and the intermediate shaft (ai) is provided by double rings (bvi) as shown in FIG. 5B. The crankshaft (v) drives the intermediate shaft (i) during its displacement. The distance between the transmission shaft (t) and the intermediate shaft (i) is ensured both by the grooves of the fixed partitions (rfi) and by the grooves of the movable partitions (rmi). As shown in Figure 4B1, one or more double rings (bit) can be added to contribute to it. Bearings may be mounted on the shafts and make contact with the grooves of the fixed and movable partitions to prevent frictional forces on the shafts. As shown in Fig. 6A, the crankshaft (v) can be split because the force exerted by the pistons is transmitted to the intermediate shaft (i) over the entire length of the crankshaft, which limits the torsional forces experienced by the crankshaft. crankshaft. A split crankshaft allows the mounting of bearings (r) on both the crank shaft (av) and the crank pins (ma). The gears (pv) connecting the pinions of the intermediate shaft (pi) can be used to support the crank pins (ma) and the split shaft of the crankshaft (av). In part hollowed out they can also play the role of counterweight. The connecting rods (bi) can be fixed on the crank pins (ma) by bearings, the crank pins (ma) will then be fixed to the gears (pv). Similarly, the bearings (r) may be placed on the split shaft of the crankshaft (av) which will in turn be fixed to the gears (pv). After mounting the crankshaft (Fig.

6B and C), the portions of the crank shaft (av) may be placed in the grooves of the fixed partitions (rfv) and movable partitions (rmv) and the double rings connecting the intermediate shaft ( bvi). As shown in FIG. 6A, the bearings can be placed on the axis of the transmission shaft (at) and on the axis of the intermediate shaft (ai) together with the 5 gears (pi and pt) and the portions of double rings ensuring the positioning of the axes (bvi and possibly bit). As shown in FIGS. 6B and C, once assembled the shafts (i and t) can be assembled to the fixed (cf) and movable (cm) partitions, the drive shaft (ag) of the gears (pg) ensuring Movement of movable partitions can also be fixed to fixed partitions as shown in Figure 5C. The fixed (rfv and rfi) and mobile (rmv and rmi) grooves are open on the outside to allow the introduction of the mounted shafts (av and ai) as shown in Figs. 5C and 5D. After assembly of the mechanism, portions of rings (pb) ensure the closing of the grooves and the rigidity of the partitions. Once assembled, it will be fixed in the crankcase.

As shown in FIG. 6C, the fixed partitions (cf), the movable partitions (cm) and the double rings (bvi) are placed at each portion of the crank shaft (av) and at its ends in order to maintain rigidity of the mechanism (The intermediate shaft is shown in section, the drive shaft and the crankshaft are set back).

The crankshaft (v) and the intermediate shaft (i) are contained in the crankcase. The transmission shaft (t) passes through the crankcase and carries at its end the drive pulley of the belt or the timing chain (pot) as shown in Figures 1 and 2. The shaft (ag) bearing the gears (pg) ensuring the movement of the moving partitions (cm) passes through the crankcase, it is actuated by the mechanism 25 determining the operating mode of the engine. The elements driven by the engine (water pump, alternator ...) can be linked to the fixed shafts of the engine. The third modification relates to the air circuit, it is shown diagrammatically in FIG. 7. FIG. 8 shows a view of the air circulation in the various modes of operation. Figure 9 shows a variant for increasing the pressure of the compressed air by the projection of water on the proximal part of the exhaust pipe (sauna effect).

3025251 11 The compressed air circuit operates according to the following principle. The compressed air is stored at a pressure of several hundred bar in a storage tank. For the two-stroke compressed air mode, it undergoes several detents accompanied by heating by the heat released by the engine, which limits the consumption of compressed air. For both modes using compressed air (thermal and two-stroke) the air reaches a last pressure reducer at the maximum pressure required for the operating mode. The last expansion valve is under the control of the computer which releases the air at a pressure proportional to the force exerted on the acceleration control ranging from a minimum pressure to the maximum pressure 10 specific to the mode by more or less complete opening of the last regulator. For the thermal mode with compressed air supply, the air is led directly to the engine without going through the heating circuit. For both modes using atmospheric air (four atmospheric times and compressor) the air is brought to the engine downstream of the last regulator.

The circuit elements are shown in FIG. 7. It comprises a storage tank where the compressed air is stored at a pressure of several hundred bar (1). A pressure sensor (2) informs the computer and the driver by a light of the state of the compressed air reserve. The air is expanded by a first expander (3) and passes to a second reservoir (4) where it is heated by a line fed by the engine coolant passing through the reservoir upstream of the radiator (5). The first regulator (3) controlled by the computer informed by a pressure sensor (6) lowers the air pressure and maintains it at a pressure equal to the maximum pressure necessary for the operation of the engine in two-stroke compressed air mode. releasing the compressed air contained in the storage tank (1). The pressure in the reservoir (4) is equal to the maximum residual pressure of the air rejected by the engine in two-stroke compressed air mode multiplied by the rate of expansion of the cylinders when the crankshaft is in the up position. The air from the tank (4) is directed to a pipe clean to its line of cylinders if the lines of cylinders are independent, to a pipe common to the two lines of cylinders in the opposite case. The compressed air is released by a second expander (7) controlled by the vehicle computer informed by a second pressure sensor (8) of the pressure at the termination of the compressed air circuit. The released air maintains the pressure at the circuit termination at a pressure equal to the maximum pressure required for the compressed-air thermal operating mode if the cylinder line is in thermal operation mode with compressed air supply. (Fig.

8B). The released air maintains the pressure at the end of the circuit at a pressure equal to the maximum pressure required for the two-stroke compressed air mode if the cylinder line is in two-stroke compressed air mode (Fig.

8A). A valve (9) directs the compressed air directly to the cylinders via a pipe (10) for the thermal mode with compressed air supply (Fig.

8B). For the two-stroke compressed air mode (Fig.

8A) the compressed air is directed by the valve (9) to a pipe (11) leading to air compartments located in the cylinder blocks (12) and then flows in contact with the exhaust pipe in the opposite direction of the gases exhaust system in a double wall exhaust pipe (13). The heating of the compressed air by the heat engine makes it possible to recover a large part of the thermal losses of the engine by increasing the pressure of the compressed air, which corresponds to the property RET (thermal energy recovery) of the engine. mixed thermal / compressed air. A third expander (14) under the control of the computer informed of the force exerted on the acceleration control of the vehicle causes release of the compressed air to the engine at a pressure proportional to the force exerted on the acceleration control . For the two-stroke compressed air mode this pressure shall be from a minimum pressure close to the atmospheric pressure multiplied by the engine expansion ratio when the crankshaft is in the up position at a maximum pressure equal to a multiple of the same pressure equal to the air pressure rejected by the engine multiplied by the rate of expansion of the cylinders when the crankshaft is in the up position. For the thermal mode with compressed air supply this pressure will go from a minimum pressure equal to the atmospheric pressure to a maximum pressure equal to a multiple of the atmospheric pressure multiplied by the compression ratio of the engine when the crankshaft is in the low position. allowing pressure at the end of the compression phase compatible with the thermal operating mode of the engine. The air pressure at the intake is measured by a pressure sensor (15) which informs the computer. The computer moves the camshafts, which causes an early closure of the intake valve during the descent of the piston all the earlier as the pressure at the inlet is important, the displacement of the cam intake maintains the pressure at the end of the compression phase at a value compatible with the four-stroke thermal operation of the cylinder line. A thermal probe (16) informs the computer of the temperature at the end of the heating circuit of the compressed air. The computer is informed of the speed of the vehicle, the force that the driver exerts on the acceleration control and the state of the reserves of compressed air and fuel. If the force that the driver 10 exerts on the acceleration control is moderate, if the vehicle has reached cruising speed and the temperature at the termination of the heating circuit is sufficient to significantly increase the pressure of the compressed air, the computer controls the passage of a line of cylinders or two lines of cylinders in two-stroke compressed air mode, it cuts off the supply of fuel and possibly the ignition of the lines of cylinders operating in two-stage compressed air mode . If only one of the two cylinder lines is put in two-stroke compressed air mode, the line operating in thermal mode will heat the compressed air of the line operating with compressed air. If the two lines operate with compressed air there will be a cooling of the engine and the exhaust pipe, the computer 20 will restore the operation of one of the two lines in thermal mode to maintain a sufficient temperature to the proper functioning of the line operating with compressed air. The calculator will ensure a balance of fuel and compressed air consumption to allow simultaneous depletion and simultaneous recharging of both reserves. If the reserve of compressed air is lower than the fuel reserve it will limit the use of both modes using compressed air. If the fuel reserve is lower than the reserve of compressed air it will favor them. The indicator informing the driver of the autonomy of the vehicle will take into account the state of the two reserves.

For the four-stroke thermal mode with motor supply by atmospheric air and for the two-stroke compressor mode used for braking to recover the kinetic energy of the vehicle (Fig.

8C), the motor is supplied with external air supplied by a pipe (17) located downstream of an air filter. the transition to these two modes is accompanied by a closing of the last regulator (14) controlling the release of air in both modes using compressed air and the opening of a valve which may be a simple valve (18) bringing the outside air into the inlet pipe downstream of the last expander (14). The transition from one mode to another is accompanied by a displacement of the cam shaft and possibly the crankshaft. For the transition from the two-stroke compressed air mode to the thermal mode with compressed air supply which will be accompanied by a decrease in the pressure of the compressed air 10 it will be necessary to avoid that the engine is powered by hot air . It may be necessary to lower the air pressure in the heating circuit before tilting the air supply to the pipe (10) through the valve (9) by closing the regulator (7) and releasing the pressure by the action of the motor. A check valve (Fig. 6; 19a) mounted on a spring (19b) will equalize the pressures by reversing the flow of air in the heating pipe leaving the valve (9) open on both lines (10 and 10). 11) for a short time. As shown in FIG. 9A, the two-stroke compressed air pressure and the recovery of the thermal energy of the engine could be considerably increased by the splash of water on the proximal portion of the exhaust sauna (20). This water could come from a reserve (21) which would be reconstituted by the condensation of the projected water, the water produced by the combustion and the condensation of the moisture of the air at the end of the pipe. exhaust by exploiting the cold produced by the expansion of compressed air. The water spray would be triggered if the temperature measured at the end of the exhaust pipe is sufficient to produce steam. The compressed air is stored at ambient temperature at a pressure of the order of 200 to 400 bars in the storage tank (1). Its first expansion lowers its pressure to about 70 to 80 bar (probable maximum pressure for the two-stroke compressed air mode), the relaxation is accompanied by a drop in temperature. The expanded air is directed by a pipe (22) to the end of the exhaust pipe and flows against the exhaust gas (23). The cooling of the exhaust gas causes the condensation of the liquids contained in the exhaust gas. The compressed air is then fed through a second line (24) into the tank where it is heated by the engine coolant (4). The bottom of the exhaust pipe is funnel-shaped (25) and allows the collection of a water-rich liquid (26) which will be used to reconstitute the water reserve (27). After decantation of the oils by flotation (28) and heavy elements by decantation (29) and after filtering (F) the liquid can be projected again on the proximal part of the exhaust pipe (20). There will be no need to replenish the water supply by an external supply if the condensation allows a sufficient recovery. The exhaust gases contain many pollutants such as oil vapors and unburned or partially burned fuel residues, the cold produced by the expansion of the compressed air could allow exhaust gas distillation to be carried out and to make the engine mixed thermal / compressed air a particularly clean engine as shown in Figure 9B. A thermal probe (30) measures the temperature of the gases upstream of the termination 15 where the condensation takes place. An aerodynamic flap (31) controlled by the computer makes it possible to cool the exhaust pipe upstream of the termination by directing a flow of air towards the pipe if the temperature of the exhaust gases measured by the probe (30) is too high. high to allow condensation by cold at the termination of the exhaust pipe.

If the temperature is sufficiently low, condensed distillation will occur along the compressed air line. The bottom of the exhaust pipe forms several funnels (32) where the condensation liquid is collected. The first funnels (33) will collect a liquid (34) enriched with the least volatile products (water and oil residues). Decantation of the liquid will separate the lighter oil residues (35) from the heavier water (36). The last funnels will collect a liquid (37) enriched with the most volatile products (unburned or partially burned fuel residues). Intermediate funnels a mixture (38). The liquid from the intermediate funnels (38) may be mixed with the liquid from the first funnels after settling by flotation of the oils (36). After filtering the liquid (F) it will reconstitute the water reserve (40). The oils from the first funnels (35) and the most volatile residues (37) will be mixed (39) and collected (39a) or incorporated in a small quantity after filtering (F) to the fuel (39b) to be burned.

3025251 16 The mixed engine could also work with lost water. Water and compressed air could be contained in the same storage tank and be recharged at the same time. The compressed air line would start from the top of the tank, the water pipe from the bottom. The pressure of the compressed air would allow high pressure water to be projected onto the proximal part of the exhaust pipe. Figure (10) summarizes the different modes (m1 to m5), the profile presented by the cams at the valve shanks (A), for the intake valve (a) and for the exhaust valve (e). It shows the position of the various shafts (B) with the drive shaft (t), the intermediate shaft (i) and the crankshaft (y) depending on the mode. It shows the air supply circuit according to the mode (C). The modes ml and m2 correspond to the thermal operation with compressed air supply, this mode is triggered when the driver exerts a large force on the acceleration control. The crankshaft is in the down position.

The pressure of the compressed air is maintained at the maximum pressure for this mode by the second expander. The opening of the last expansion valve is proportional to the force exerted on the acceleration control of the vehicle and releases the air at a pressure ranging from atmospheric pressure to a maximum pressure specific mode. Early closure of the intake valve maintains pressure at the end of the compression phase consistent with engine operation in four-stroke thermal mode. The computer is informed of the intake pressure by a pressure sensor and determines, by the position of the camshaft, an early closing of the intake valve even earlier than the air pressure at the inlet. admission is important. From m3 to ml the pressure on admission is increasing. The compressed air is directed directly to the cylinders without going through the heating circuit. The m3 mode corresponds to the four-stroke thermal operation mode with air supply at atmospheric pressure. The crankshaft is in the down position. The last expansion valve is closed, a valve opens a pipe which brings the outside air to the cylinders (the valve can be a simple valve). For modes m4 and m5 the fuel supply is cut off, as is the ignition if the vehicle is on gasoline. The m4 mode corresponds to the kinetic energy regeneration mode 3025251 17 which converts the motor into a two-cycle compressor. The relief presented by the cams in the four-stroke thermal mode (m3) is doubled. Each lowering of the piston is accompanied by an opening of the intake valve, each piston ascent of an opening of the exhaust valve.

The crankshaft height that determines the compression ratio of the engine is proportional to the force exerted on the brake control and provides a proportional braking force. As for the four-stroke thermal mode with atmospheric air supply (m3), the motor is powered by outside air.

The mode m5 corresponds to the two-stroke compressed air mode. The opening of the intake valve is limited to a short time at the beginning of the descent of the piston. The crank shaft is in the up position. The air from the compressed air reservoir is directed by a pipe to compartments in the cylinder block and completes its warming by flowing against the exhaust gases in a double-walled pipe before being fed into the cylinder blocks. cylinders. The second expander controlled by the computer informed of the pressure at the end of the circuit by a pressure sensor maintains the pressure at the maximum pressure for this mode of operation. The last regulator controlled by the computer informed of the force exerted on the acceleration control releases the air at a pressure between a pressure close to atmospheric pressure multiplied by the rate of expansion of the cylinder when the crankshaft is in the up position. and the maximum pressure for two-stroke compressed air mode. The combined thermal / compressed air engine is an alternative to the current engine modes, which are the thermal mode, the electric mode or the compressed air mode. It presents the advantages of the engine by its power and its autonomy, the compressed air mode makes it possible to save money which will compensate for the disadvantage of having to recharge both the reserve of fuel and the supply of compressed air. The compressed air supply can be reconstituted at home by means of a compressor but also on long trips to the fuel distributors from a larger tank of compressed air produced locally. Reloading the reserve would be fast. The same pumps could both dispense fuel and compressed air. The compressed air mode optimizes the thermal mode by giving the engine a RET (thermal energy recovery) property. The conversion of the engine into a two-stroke braking compressor also gives it the REC property (kinetic energy recovery). The possibilities of the system are considerable. The energy efficiency of the engine is about 30%, the recovery of a fraction of the 70% lost in the form of heat offers significant fuel savings prospects. The recovery of the kinetic energy during braking allows fuel savings in the urban cycle of the order of 30%, the transformation of the engine into a two-stroke compressor to develop a progressive braking force and proportional to the force exerted on 10 the brake control, the passage of the engine in two-stroke mode and the increase of the compression ratio of the engine will considerably increase the braking force. The compressed air during braking will restore the reserve of compressed air. Despite the promising start, the compressed air engine has not been followed by industrial development because of its low power resulting in part from the cooling of the air during its expansion. In the combined thermal / compressed air engine, the recovery of the heat released by the engine overcomes this disadvantage. The production of steam and the possibility of condensing the steam at the termination of the exhaust duct by taking advantage of the cooling by the expansion of the compressed air would make it possible to achieve a closed circuit of water which would considerably increase the efficiency of the engine. Compressed air mode and recovery of thermal energy from the engine. It would also help to clean up exhaust gases by condensing unburned or partially burned fuel oils and residues that can either be collected or burned by being mixed in small quantities with fuel. Operating a vehicle only with compressed air poses the problem of limited power, the combined thermal / compressed air engine solves this problem. The thermal mode would be used for acceleration, the vehicle would go into compressed air mode or mixed with a line of cylinders operating in thermal mode and the second line operating with compressed air (the line operating in thermal mode providing the heat allowing 30 optimize the line operating with compressed air). This mode would be triggered when the vehicle has reached cruising speed and needs only moderate power to maintain its cruising speed. The presence of camshafts carrying complex profile cams makes it possible to create a new mode which is the thermal mode 3025251 19 four-stroke with compressed air supply that can momentarily bring a power greater than the power of a combustion engine. same displacement. The low cost of compressed air compared to the rising cost of fuels would make the system competitive. The prospect of reducing the cost per kilometer of a vehicle to a fraction of its current cost without reducing its performance is not illusory.

Claims (9)

CLAIMS1) Piston engine characterized in that it can operate in four-stroke thermal mode with atmospheric air supply, in four-stroke thermal mode with compressed air supply at variable pressures, two-stroke compressed air mode and two-stroke compressor mode with presence braking (Fig. 1): camshafts capable of sliding on their axle carrying complex profile cams imparting to the valves the movements necessary for the various operating modes (A.1); one or more movable crankshafts capable of varying the volume ratio of the combustion chamber between the time when the piston is in the up position and the time when the piston is in the down position (A.2); an air circuit for delivering to the engine either atmospheric air or compressed air at the pressure necessary for the various operating modes from a storage tank (1) and for heating the compressed air during its relaxation due to the heat generated by the engine when operating in thermal mode (B.3). 2) A piston engine according to claim 1 characterized in that each line of cylinders has camshafts carrying cams with complex profile (Fig. 2), each camshaft (a) is driven by the engine by a pulley (poa), the camshafts (a) are integral with their pulley (poa) in the direction of rotation but can slide in the pulley and oppose to the intake and exhaust valves the profile necessary for the operating mode ( Fig. 3). 3) A piston engine according to claim 1 characterized in that each line of cylinders comprises a system of articulated shafts (Figures 4 and 5), it comprises a movable crankshaft (y), a movable intermediate shaft (i) connected to at the crankshaft (v) and at a fixed transmission shaft (t), the transmission shaft (t) may be common to several lines of cylinders which will rotate at the same speed (Fig. 1Ca), the engine may have lines of independent cylinders (Fig. 1Cb), the transmission shaft (t) is then connected by a gear determining a plurality of transmission ratios to a common transmission shaft (tc) leading to the vehicle gearshift device. 4) piston engine according to claim 3 characterized in that the movement of the crankshaft is obtained by the presence of fixed partitions (cf) having two fixed grooves (rfv and di) traversed by the crank shaft (av) and by the intermediate shaft (ai) and by the presence of movable partitions (cm) pivoting on the axis of the transmission shaft (at) and having two movable grooves (rmv and rmi) traversed by the crank shaft ( av) and the intermediate shaft (ai). The fixed grooves (rfv) follow the trajectory of the crank shaft (av) from its low position to its high position (Fig. 5C1 and 5C2), the movable grooves (rmv) are oblique (Fig. 5D), the pivoting movable partitions moves the crankshaft (av) at the intersection of the fixed grooves (rfv) and the moving grooves (rmv), the fixed grooves (rfi) and the moving grooves (rmi) maintain the distance between the transmission shaft (at) and the intermediate shaft (ai), the crankshaft (av) drives the intermediate shaft (ai) during its movement through double rings (bvi). The crankshaft is in the down position for the thermal operating modes (Fig. 10Bm1 to 10Bm3), in the up position for the two-stroke compressed air mode (Fig. 10Bm5), for the two-stroke compressor mode (Fig. 10Bm4) its height is proportional to the force exerted on the brake control. 5) piston engine according to claim 1 characterized in that for the thermal mode with atmospheric air supply (Cm3) and the two-stroke compressor mode used for braking (Cm4) the engine is powered by outside air, for the thermal mode with compressed air supply (Cm1 and Cm2) and for the two-stroke compressed air mode (Cm5), the motor is supplied with compressed air from a storage tank, for compressed air mode. Two times (Cm5) the air passes through a heating circuit where it is warmed by the heat generated by the motor when it operates in thermal mode. 6) Piston engine according to claim 5, characterized in that for the two-stroke compressed air mode (Fig. 8A) and the thermal mode with compressed air supply (Fig. 8B) the compressed air of the storage tank (1) ) is directed to a second tank (4) where it is reheated by the engine coolant line leading to the vehicle radiator (5), the pressure in the second tank (4) is maintained at the maximum pressure necessary for the two-stroke compressed air mode by release by compressed air contained in the storage tank (1). For the two-stroke compressed air mode (Fig. 8A) the compressed air is directed by a valve (9) to a line (11) leading to air compartments in the engine block (12). its heating by flowing against the exhaust gases in a double-wall exhaust pipe (13), it is then directed to a pipe common to the thermal mode with air supply 3025251 22 compressed closed by a third expander (14) , the pressure is maintained at the maximum pressure for the two-stroke compressed air mode by releasing the compressed air contained in the second tank (4). For the thermal mode with compressed air supply (Fig. 8B) the compressed air from the tank (4) is directed by the valve (9) to a pipe (10) leading to the common pipe closed by the third expansion valve (14) , the pressure is maintained at the maximum pressure for the thermal mode with supply by compressed air by the release of the air contained in the second tank (4). For both modes using compressed air the third expander (14) delivers the air at a pressure proportional to the force exerted on the acceleration control. For the thermal mode with compressed air supply the pressure of the compressed air delivered to the engine is measured (15), the computer places the camshafts in a position allowing by an early closing of the intake valve 15 a pressure in end of compression phase compatible with the four-stroke thermal operation mode of the engine. For the two-cycle compressor mode and for the thermal mode with atmospheric air supply (Fig. 8C) the third expander (14) is closed, a valve (18) which can be a simple valve directs the outside air to the air duct. supply of the motor downstream of the third expander (14). 7) piston engine according to claim 1, claim 5 and claim 6 characterized in that it comprises a water circuit (Fig 9) with a projection of water on the exhaust pipe (20) increasing the pressure of the compressed air and a device for condensing the water of the exhaust gases to make a closed circuit (Fig. 9A), the condensation takes place at the termination of the exhaust pipe by cooling the pipe exhaust system (23) due to the expansion of the air in the pipe (22, 23, 24) leading the compressed air from the storage tank (1) to the second tank (4), the condensed water (26) after decantation of the oils (28) and and heavier waste (29) reconstitutes the water reserve (27), after filtering (F) it is again projected on the exhaust pipe (20). A variant carries out a distillation of the exhaust gas (Fig. 9B) by step-by-step collection of the condensates, the decantation of the less volatile condensates (34) makes it possible to recover the lighter oil residues (35) which are mixed (39) at the most volatile condensates (37) rich in unburnt or partially burned fuel residues, the mixture is either collected (39a) or incorporated after filtering (F) in a small amount to the fuel (39b) for burning, the Intermediate volatility condensates (38) are mixed with the purified less volatile condensates of their oil residues (36) and reconstitute after filtering (F) the water supply (40). 5 8) Control device comprising a computer of an engine according to any one of claims 1 to 7 characterized in that it determines the operating mode according to the state of the fuel reserve and compressed air, the temperature of the compressed air at the end of the heating pipe, the force exerted on the acceleration control, the force exerted on the brake control 10 and the speed of the vehicle, it determines the position of the shafts with cams (Fig. 3 and 10), the position of the crankshaft (Fig. 4, 5 and 10) and the air intake circuit (Fig. 8 and 10). 9) Control device comprising a computer according to claim 8 characterized in that it triggers the two-stroke compressed air mode if the temperature of the compressed air at the end of the heating circuit is important and if the power released by the engine in compressed air mode is sufficient to ensure the power determined by the force exerted on the acceleration control, it triggers the thermal mode with compressed air supply when the driver exerts a significant force on the acceleration control, he triggers the two-stroke compressor mode when the driver actuates the brake control and places the crankshaft at a height proportional to the force exerted on the brake control.