Abstract: A method for calculating transient fuel wall wetting characteristics of an operating engine is described. The method accounts for cylinder valve deactivation of cylinders in the engine in calculating the dynamic fueling compensation. In one example, fuel vaporization effects from fuel puddles in deactivated cylinders is considered when calculating the fueling compensation for active cylinders.

Abstract: A method is disclosed for controlling the air-fuel ratio in a four-stroke gasoline direct-injection controlled auto-ignition combustion. The engine is operated with two sequential pairs of expansion and contraction strokes during two revolutions of the engine crank, the two revolutions defining a combustion cycle. A system is employed for variably actuating the intake and exhaust valves and adjusting the flow of air and burned gases entering the combustion chamber. Adjusting the flow affects the resulting air-fuel ratio in the combustion chamber. The valve actuating system is employable to operate the intake and exhaust valves with an exhaust re-compression or an exhaust re-breathing valve strategy. Either valve strategy affects the air-fuel ratio in the cylinder and causes a proportion of burned gases from previous combustion cycles to be retained in the cylinder to provide the necessary conditions for auto-ignition of the air-fuel mixture.

Abstract: A method of operating a four-stroke gasoline direct-injection controlled auto-ignition combustion engine includes opening both the intake and exhaust valves during terminal portions of the expansion strokes and initial portions of the contraction strokes, injecting fuel directly into the combustion chamber for mixing with retained gases and igniting the fuel near the ends of the contraction strokes. In the process, combustion gases are expanded to produce power during major portions of the expansion strokes, combusted gases are blown down into the exhaust outlet and the air inlet and are partially redrawn into the cylinder with fresh air during the terminal portions of the expansion strokes so the air charges are heated by the hot exhaust gases. Portions of the charges re-expelled and the remaining portions of the charges and injected fuel are compressed for ignition of the dilute fuel/air and exhaust gas mixture. Substantial reductions of NOx emissions result from the method.

Abstract: A control device for a multicylinder spark-ignition engine includes a flow path switching unit for switching intake and exhaust flow paths between a two-cylinder interconnect configuration and an independent cylinder configuration and an air-fuel ratio control unit. In a low-load, low-speed operating range, the flow path switching unit switches the engine to the two-cylinder interconnect configuration, and the air-fuel ratio control unit produces a lean mixture having an air-fuel ratio larger than the stoichiometric air-fuel ratio by a specific amount in preceding cylinders by injecting fuel thereinto and an air-fuel ratio approximately equal to the stoichiometric air-fuel ratio in following cylinders by supplying fuel together with burned gas of a lean mixture state discharged from the preceding cylinders into the following cylinders to perform combustion in special operation mode.

Abstract: The present invention relates to a six-stroke internal combustion engine with intake-exhaust valves. All valves in the combustion chamber are named intake-exhaust valves, because said valves function as both intake valves in an intake stroke and exhaust valves in an exhaust stroke. Because in said engine each cycle comprises an intake stroke, a compression stroke, a power stroke, an exhaust stroke, the fifth stroke and the sixth stroke, there is an interval between the exhaust stroke and the intake stroke of the next cycle. Said interval includes strokes five and six. During the exhaust stroke and said interval, all exhaust gases are expelled from a cylinder and cylinder head completely before the intake stroke of the next cycle begins. Utilizing every valve in the combustion chamber as an intake and exhaust valve increases the volumetric efficiency of the engine.

Abstract: A method and a device for operating an internal combustion engine having a plurality of cylinders are described, each cylinder having at least one intake valve and one exhaust valve having fully variable valve control, a fuel feed to at least one first cylinder of the plurality of cylinders being deactivated, a first quantity of fresh air being drawn in by opening the at least one intake valve of the at least one first cylinder in a first downward movement of the piston of the at least one first cylinder, and a second quantity of fresh air being ejected by opening the at least one exhaust valve with a first upward movement of the piston of the at least one first cylinder.

Abstract: The invention relates to a method of operating an internal combustion engine with a six-stroke process involving the following sequence of events: 1st stroke (I): air intake into the combustion chamber, 2nd stroke (II): compression of the air and injection (3a) of a first fraction of gasoline fuel into the combustion chamber, 3rd stroke (III): first working stroke after first ignition (5) of the mixture, said ignition (5) being initiated by an ignition device, 4th stroke (IV): new compression of the contents of the combustion chamber, 5th stroke (V): second working stroke after second ignition (6) of the fuel-air mixture contained in the combustion chamber, 6th stroke (VI): expulsion of the exhaust gases from the combustion chamber, a second fraction of gasoline fuel being injected (3b) prior to the second ignition (6).

Abstract: By the utilizing of a slave cylinder working in coordination with a master cylinder, the slave cylinder both receives cool atmospheric air and receives hot, partially un-burnt exhaust gases from the master cylinder to create a second power-stroke in the slave cylinder. With the two coordinating cylinders, the entire working process is from 0 to 810 degrees of revolution crankshaft. The master cylinder cycles work from 0 to 720 degrees of revolution and slave cylinder cycles work from 90 to 810 degrees of revolution. The master cylinder begins to intake air and fuel at 0 degree of revolution and slave cylinder begins to intake air at 90 degrees of revolution. There is an angle of 60-120 degrees differences between master and slave cylinder, where the slave cylinder is trailing the master.

Abstract: The invention relates to a method of operating an internal combustion engine with a six-stroke process involving the following sequence of events:

Abstract: The present invention relates to a six-stroke internal combustion engine with intake-exhaust valves. All valves in the combustion chamber are named intake-exhaust valves, because said valves function as both intake valves in an intake stroke and exhaust valves in an exhaust stroke. Because in said engine each cycle comprises an intake stroke, a compression stroke, a power stroke, an exhaust stroke, the fifth stroke and the sixth stroke, there is an interval between the exhaust stroke and the intake stroke of the next cycle. Said interval includes strokes five and six. During the exhaust stroke and said interval, all exhaust gases are expelled from a cylinder and cylinder head completely before the intake stroke of the next cycle begins. Utilizing every valve in the combustion chamber as an intake and exhaust valve increases the volumetric efficiency of the engine.

Abstract: The invention concerns reciprocating piston internal combustion engines and in particular six-stroke type, FIG. 1. In this engine, one cycle comprises an intake stroke, a compression stroke, a power stroke, an exhaust stroke, the fifth stroke and the sixth stroke. In this engine, all combustion chamber valves A, B, C and D FIGS. 1 and 2 function as both intake valves in the intake stroke and exhaust valves in the exhaust stroke. The name of the valves A, B, C and D is intake-exhaust valves or (inlet-outlet valves). Intake ports 1, 2, 3 and 4 and exhaust ports 5, 6, 7 and 8 are connected to each other in the cylinder head 22 of the engine. As a result, fuel-air mixture is drawn into a cylinder 21 via the intake ports 1, 2, 3 and 4 and all combustion chamber valves (intake-exhaust valves) A, B, C and D in the intake stroke and exhaust gases are expelled from the cylinder via the same valves (intake-exhaust valves) and the exhaust ports 5, 6, 7 and 8 in the exhaust stroke.

Abstract: An internal combustion engine and its method of operation including at least one embodiment operating on a six-stroke cycle and including at least one piston and cylinder assembly. The six-stroke cycle includes two power strokes, the latter of which is the result of a water to steam conversion process utilizing the heat of the exhaust gas from the first power stroke. A second embodiment comprises a hybrid power generating assembly incorporating alternative, first and second power sources respectively comprising an internal combustion engine and a water injection engine, the latter of which operates on the water to steam conversion process, wherein the required heat therefore is derived from the exhaust gas of the internal combustion engine. The second power source drives a source of electric energy which powers an electric motor, wherein the electric motor and the internal combustion engine are both connected in driving relation to a power take-off.

Abstract: A direct injection type internal combustion engine has an intake and exhaust mechanism for intaking and exhausting air for a predetermined period of time between a second half of a second expansion stroke and a first half of a first compression stroke following the second expansion stroke so that the first compression stroke, a first expansion stroke, a second compression stroke, and the second expansion stroke can be repeated sequentially along with rotation of a crank shaft; and a control device for controlling fuel injection. The control device injects first fuel during the first compression stroke and injects second fuel during the first expansion stroke or the second compression stroke. Therefore, the first fuel executes the first combustion process, and the second fuel is then injected into burnt gases generated in the first combustion process to enable a second combustion process following the first combustion process.

Abstract: An internal combustion engine and a method for operating the multi-stroke combustion engine is disclosed. The engine is provided with individual variably controlled inlet and outlet valves in each cylinder. Operation of the engine involves controlling the inlet and outlet valves so that the opening and closing of the valves are adapted to a second stroke mode that is different from a first stroke mode in which the engine is presently running. Fuel injected into the cylinders is controlled so that it is injected prior to an expansion stroke. The transition from the first stroke mode to the second stroke mode occurs independent of the operating condition of the engine throughout the entire operating range of the engine.

Abstract: The method for cylinder-charge control consists in implementing an internal recirculation of residual gas in the cylinder, through controlling the closing times (AS) of at least one exhaust valve of the respective cylinder and by opening (EÖ1) at least one intake valve in the vicinity of top dead center (OT) of the piston, along with intermittent discharge of residual gas in front of the at least one intake valve, and that within one charge-exchange process in the cylinder, in at least two phases (EÖ1, ES1, EÖ2, ES2) that are offset in time from one another, at least one intake valve is opened. This method optimizes the engine operation in the warm-up phase from the standpoint of consumption, pollutant emission and running smoothness.

Abstract: An internal combustion engine and its method of operation which is designed to operate on a six-stroke cycle and which may include at least one but preferably a plurality of piston and cylinder assemblies each of which are characterized by a cylinder having a piston reciprocally mounted therein and intake an exhaust valves cooperatively mounted to regulate fluid flow into and out of the cylinder. An injection assembly is connected to each of the piston and cylinder assemblies and structured to inject water into the cylinder during a predetermined portion of the six-stroke cycle. A central processor is at least partially responsive to data received from a sensor assembly associated with on the internal combustion engine at strategic locations so as to determine the energy content within the one or more cylinders and thereby regulate and control the timing and quantity of the injected water.

Abstract: A method for operating an internal combustion engine with variable gas exchange control times and with variable control times for the inlet and outlet valves includes, in various operating modes, direct exhaust-gas recirculation by the retarded closing of the outlet valve, exhaust-gas retention by the insertion of a compression and expansion phase with closed gas exchange valves, exhaust-gas filling of the combustion space by the opening of the outlet valve in the gas intake phase, with the inlet valve closed, and/or an apportionment of the combustion action, if appropriate combined with an exhaust emission control measure, to a plurality of working strokes of a working cycle. The various operating modes may be set individually for each combustion space and each working cycle. The method may by used, for example, for gasoline and diesel engines of motor vehicles.

Abstract: Secondary air is strategically introduced into a combustion chamber of an internal combustion engine event after the main combustion event to reduce HC and CO emissions. While the technique is applicable to virtually any otto cycle engine, it is particularly well-suited for use in a “rich burn” utility engine typically operating at an equivalence ratio (ER) of about 1.2 or above. Such engines start easily, run well, and emit low levels of NOx at ERs on the order of 1.2. The invention takes advantage of these benefits by admitting an air/fuel charge and allowing otto-cycle combustion to occur in at least generally the usual fashion (although at least preferably as rapidly as possible for a given engine design), using the standard fuel-rich carburetor calibration to fuel the engine.

Abstract: A system and a method for operating an internal combustion engine at a six-stroke, eight-stroke, or greater number of strokes cycle is disclosed. The combustion of the fuel and air is accomplished in two combustion steps with at least one expansion and compression process in between the two combustions, with the second combustion occurring at a stoichiometric air-fuel ratio. The first combustion at lean air-fuel ratio provides high efficiency. The products of the first combustion are subjected to a second combustion event at stoichiometric air-fuel ratio. Consequently, high conversion efficiency of nitrogen oxides in the exhaust aftertreatment device, available at stoichiometric conditions, can be achieved.

Abstract: An internal combustion engine and a method for operating the multi-stroke combustion engine is disclosed. The engine is provided with individual variably controlled inlet and outlet valves in each cylinder. Operation of the engine involves controlling the inlet and outlet valves so that the opening and closing of the valves are adapted to a second stroke mode that is different from a first stroke mode in which the engine is presently running. Fuel injected into the cylinders is controlled so that it is injected prior to an expansion stroke. The transition from the first stroke mode to the second stroke mode occurs independent of the operating condition of the engine throughout the entire operating range of the engine.

Abstract: The present invention concerns a process of construction of a five-stroke internal combustion engine comprising especially at least one low-pressure cylinder (1) functioning in a two-stroke mode located between two high-pressure combustion cylinder (2,3) functioning in a four-stroke mode, the work chamber (C2, C3) of each combustion cylinder (2,3) being capable of communicating with the work chamber (C1) of the low-pressure cylinder (1) via a decanting valve (9) associated with the combustion cylinders (2,3) and a decanting manifold (16,17), and comprising a means of excess feeding the combustion cylinders (2,3), this process being characterized by the fact that the volume compression ratio of the combustion cylinders is relatively low, so as to be able to be highly supercharged.

Abstract: A direct injection type internal combustion engine has an intake and exhaust mechanism for intaking and exhausting air for a predetermined period of time between a second half of a second expansion stroke and a first half of a first compression stroke following the second expansion stroke so that the first compression stroke, a first expansion stroke, a second compression stroke, and the second expansion stroke can be repeated sequentially along with rotation of a crank shaft; and a control device for controlling fuel injection. The control device injects first fuel during the first compression stroke and injects second fuel during the first expansion stroke or the second compression stroke. Therefore, the first fuel executes the first combustion process, and the second fuel is then injected into burnt gases generated in the first combustion process to enable a second combustion process following the first combustion process.

Abstract: An internal combustion engine and its method of operation which is designed to operate on a six-stroke cycle and which may include at least one but preferably a plurality of piston and cylinder assemblies each of which are characterized by a cylinder having a piston reciprocally mounted therein and intake an exhaust valves cooperatively mounted to regulate fluid flow into and out of the cylinder. An injection assembly is connected to each of the piston and cylinder assemblies and structured to inject water into the cylinder during a predetermined portion of the six-stroke cycle. A central processor is responsive to signals received from a sensor assembly mounted on the internal combustion engine at strategic locations so as to determine the energy content within the one or more cylinders and thereby regulate and control the timing and quantity of the injected water.

Abstract: A variable valve type internal combustion engine has cylinders and electromagnetically actuated intake and exhaust valves for each cylinder. The intake air amount fed to the cylinder is controlled by controlling the close timing of the intake valve.

Abstract: A piston internal-combustion engine has a control system for controlling the number of strokes of the combustion process taking place inside a combustion space. As a function of operating parameters, the control system controls the engine operating process such that the process has a variable cycle of at least four strokes. A pushing of a charge out of a combustion space of the piston internal-combustion engine does not take place before one or several operating parameters have reached one defined limit value, respectively.

Abstract: An internal combustion engine comprises one or more pairs of first and second cylinders, the first cylinder having a larger swept volume than the second cylinder and respective first and second pistons reciprocable in the cylinders. The second piston has a drive stem and divides the second cylinder into a first volume containing the drive stem of the second piston and a second volume between the two pistons. An air inlet and an exhaust outlet are provided for the first cylinder. A common combustion space is formed between the pistons when the pistons are substantially at their inner dead center positions, the combustion space comprising the second volume. A transfer means enables gas flow between the first volume and the combustion space whilst an inhibiting means inhibits the movement of a substantial amount of fuel/air mixture from the first volume into the second volume until toward the end of the compression stroke of the second piston.

Abstract: An inventive internal combustion engine adapted for an eight piston stroke operating cycle. The rate of comsumption of fuel and air mixture, and the pressure at which it is ignited and combusted, is enhanced by the addition of a holding chamber for fuel and air mixture which retains an initial intake charge of mixture to be later mixed with a subsequent intake charge before compression and combustion within the cylinder. The engine is therefore capable of greater power with given size cylinders. Conversely, the engine is capable of producing a target rate of fuel consumption and power output with smaller cylinders. The engine may also be designed to operate in a Diesel manner utilizing an appropriate hydrocarbon fuel.

Abstract: A method for operating a reciprocating piston-type internal combustion engine selectively in two-stroke, four-stroke, and six-stroke mode includes: providing transfer valves, transfer passage means between piston cylinders, selectively controlling the actuation and timing of the intake, exhaust and transfer valves, and alternatively operating the intake and exhaust valves for each piston cylinder in overlapping sequence during each crankshaft revolution to provide two-stroke operation, operating the intake and exhaust valves in sequence during each second crankshaft revolution to provide four-stroke operation, operating the intake, exhaust, and transfer valves sequentially to cause a secondary expansion stroke in an adjacent piston cylinder to provide six-stroke operation of the engine.

Abstract: A method of phaseshifting a variable cycle engine utilizing the Otto cycle engine timing schedule for full-load and the Atkinson cycle engine timing schedule for part-load operation, the engine having multiple intake valves and an exhaust valve, phaseshifting of the intake and exhaust events coupled with adjustment of the clearance volume and the use of residual gas in the cylinder as a determinant of the intake charge volume and the compression end temperature level, to provide a high engine operating efficiency while concurrently lowering nitrogen oxide emissions and eliminating the need for an external exhaust gas recirculating system.

Abstract: An internal-combustion engine includes two combustion spaces for each cylinder. Each combustion space is separated from the cylinder space and has a valve to open and close a passage through which communication is established between the combustion space and the cylinder space. A complete cycle consist of eight strokes of a four-stroke type engine or four strokes of a two-stroke type engine. At the start of the first expansion stroke of the cycle, the valve of the first combustion space opens to release burnt fuel into the cylinder space to power the piston. The burnt fuel from the first combustion space is expelled and fresh air is admitted into the cylinder space as in conventional four-stroke and two-stroke engines. The fresh air is compressed into the first combustion space on the first compression stroke of the cycle, and the corresponding valve closes at the end of the compression stroke.

Abstract: The heat efficiency of a piston combustion engine is increased by addition of a steam-gas cycle to the working cycle of the combustion engine. After the working cycle of the engine is finished the combustion products of the engine are again compressed in the cylinder, and water is injected into the cylinder near the end of the working stroke and at the start of the following additional compression stroke. This cools down the combustion products and causes transmission of heat accumulated in the walls of the engine to the mixture of combustion products and water mist, which mixture is expanding in the following expansion stroke.

Abstract: A method of and apparatus for starting and accelerating a vehicle through a range of vehicle speeds during which the vehicle's internal combustion engine is operated in a plurality of different operating modes is disclosed. The engine may first be cranked in a compressionless mode preparatory to starting and then run in a second mode at a relatively low speed for a warm-up interval as a six-stroke cycle engine where each engine cylinder cycle includes an essentially adiabatic compression and expansion. The system may then convert to a third mode of operation as a four-stroke cycle engine during normal engine operation. Different operating modes are available during this normal engine operation. Under high demand conditions, the engine may be run as a conventional inefficient but effective throttled engine or converted to operate in a fourth mode as a two-stroke cycle engine.

Abstract: An internal combustion engine generally utilizes a conventional four stroke process including an intake stroke, compression stroke, expansion stroke, and exhaust stroke and in addition to this four stroke process, adds a secondary process having two additional strokes for scavenging the combustion chamber with fresh air. This two stroke scavenging process employs a fresh air intake stroke and a fresh air exhaust stroke to exhaust any remaining burnt and unburnt gases from the combustion chamber.

Abstract: A six-stroke internal combustion engine with reciprocating pistons wherein the six strokes are the admission of air, the first compression accompanied or followed by a possible cooling, a second compression followed by a combustion, the first expansion producing a usable work, the second expansion producing also a usable work and finally the discharge of the combustion gases, this engine, whose combustion is either with spark-ignition (gasoline version) or with auto-ignition (diesel version), will include preferably a multiple of five non-uniform cylinders, and will have an energy efficiency of up to 30% higher than that of a four-stroke internal combustion engine.

Abstract: An engine comprises an output shaft journalled in a crankcase for rotation about an axis, an even number of cylinders, each having its axis parallel to the shaft axis, arranged in diametrically opposite pairs radially equidistant from the shaft axis and equally spaced-apart circumferentially, and a piston movable axially along each cylinder. A cross-head beam for each pair of pistons is connected to the respective pistons and journalled on a carrier that is received on the shaft for rotation with and movement axially along the shaft. A mechanism selectively moves the carrier axially along the shaft to vary the clearance volumes of the cylinders. The engine operates on a six-stroke cycle consisting of a four-stroke combustion cycle followed by a two-stroke steam cycle. The water injected for the steam cycle cools the engine. The intake air for the combustion cycle is supercharged and preheated before induction.

Abstract: A reactor plant is described comprising separate compressor and expander, and several reaction chambers. Solid reactant within each said reaction chamber is alternately compressed with reactant gas from the compressor and subsequently the consequently reacted gases are expanded through the expander. Rapid gas with solid reaction occurs since the reactant and reacted gases are alternately flowing into and out of the pore spaces of the solid reactant where a large area for reaction exists. Reacted gases are recycled back through repeated cycles of compression and expansion until adequately reacted after which they are replaced with fresh reactant gases.

Abstract: The invention relates to the diesel engine industry. To heat the air contained in the cylinder up to the fuel ignition temperature, the piston is made to execute several successive compression/expansion cycles with the inlet valve and exhaust valve closed and with fuel injection cut off. During starting and under low load, the engine operates according to a cycle of more than four strokes, for example six, eight or ten strokes. An improvement in the conditions of starting and low-load running, especially for supercharged diesel engines of reduced compression ratio.

Abstract: The machine is an engine or pump with a box shaped piston positioned between two stationary sidewalls. Opposite inward ends and inwardly facing moving sidewalls of the piston act with the two stationary case sidewalls and a block-shaped central head to define a pair of working chambers. The piston moves as restrained by a crankshaft to extract or add energy to the working chambers. Force is transferred between the piston and the crankshaft by means of a slide block on the crankshaft and the inner surface of a pair of parallel walls connected to the box shaped piston. Through the use of suitable cams and valves, four-cycle, two-cylinder equivalent engines and two-cycle, one-cylinder equivalent engines can be produced per piston. The planar walls of the machine maximize displacement while reducing mechanical stress and allowing use of heat resistant coating material, such as ceramics for thermal protection so that radiantly cooling rather than separate fluid or gaseous cooling systems can be used.

Abstract: A prechamber type diesel engine is provided with a cutoff valve in the throat connecting the prechamber and main chamber of each cylinder and operable in cyclically timed fashion to close and open communication between these chambers. Methods of engine operation are disclosed which utilize the cutoff valve to (1) trap combustion products in the prechamber from the previous expansion stroke for use in mixing with the fresh charge in the following compression stroke to provide internal EGR preferably stratified in the prechamber and (2) permit low compression ratio starting by trapping compression pressure in the prechamber from a previous compression stroke for addition to combustion chamber pressure developed on the following compression stroke to provide a higher cylinder pressure for starting than that provided by the overall compression ratio. Advantages of improved engine efficiency and reduced emission levels are anticipated.

Abstract: A six cycle combustion engine is disclosed which utilizes the 5th and 6th cycle for drawing in and expelling preheated air to further warm the combustion chamber. The flow of the coolant water has been reversed so that heat absorbed in the engine head will flow to the cylinder walls and give a warming trend thereto. In addition, a fuel system is disclosed which insures the complete mixing of air and fuel vapor molecules prior to their deliverance to the intake of the engine.

Abstract: A magnetohydrodynamic generator feeds electrical energy to a six cycle internal combustion engine having pairs of opposed pistons in each cylinder and a three port rotary valve system. A first exhaust port leads the partially combusted gases from one cylinder to the next and a second exhaust port leads the ionized, fully combusted gases to the magnetohydrodynamic generator, where the ionized exhaust gases pass through cryogenic, super-cooled magnetic fields, towards an electron emitter at the output end of the magnetohydrodynamic generator.The passage of the ionized gases through the magnetic fields produces current which is conducted to electrodes on opposed piston faces and to coils in the cylinder walls. The stream of electrodes between opposed piston faces and the coil in the cylinder sets up magnetic fields in the cylinders which isolate the combustion gases from the wall surface of the cylinder.

Abstract: The invention is an improved six-cycle engine that improves performance in fuel economy and in the power to size ratio. The six cycles are a first intake stroke, a compression and storing stroke, second intake stroke, a compression and combining stroke, the power stroke, and the exhaust stroke. The invention provides for using some of the fuel's energy that ordinarily is lost in the engine's cooling system, by absorbing heat after the first stroke and subsequently using it in the power stroke. A special configuration of a separate chamber for the compression of gases induced in the first intake stroke and a special configuration for the valve to that chamber are part of the design. Two induction cycles are included in the six cycles for each power stroke.

Abstract: Partial load control apparatus and method for internal combustion engines with internal combustion in several engine working spaces, in which with a decreasing load the number of working strokes with internal combustion is reduced per time unit; for that purpose an increasing number of the working spaces are changed-over to an after-expansion operation which includes a number of displacement and after-expansion cycles divisible by two, whereby the working gas which has only incompletely expanded in the non-changed-over working spaces during a respective working stroke with internal combustion, is fed to the changed-over working spaces in lieu of a fresh mixture and is further expanded within these changed-over working spaces.

Abstract: In a four-cycle spark-ignition internal combustion engine, knocking under a high compression ratio can be prevented by replacing the burnt gas which remains within the cylinder at the end of an exhaust stroke by a gas, such as exhaust gas, which is at a temperature approximating normal temperature, and that the ignition timing is controlled so as not to precede the knocking limit ignition point.

Abstract: An internal combustion engine and a method of operating such an engine in which a power piston and a control piston move within a cylinder for defining between the pistons a combustion chamber. Charges of gas are drawn into an intake chamber defined within the cylinder by the control piston and are then transferred through the control piston into the combustion chamber where the charge is compressed and burned to deliver power from the engine through the power piston. In accordance with the present invention, the combustion chamber is maintained at a substantially constant volume during a combustion stroke of the power piston and as power is delivered from the engine.

Abstract: A six-stroke cycle engine fires a fuel charge for a first power stroke, the exhaust gases being directed to a thermally insulated jacket surrounding the cylinder and having fins and/or baffles to recover heat from the gases and conduct the heat to the inner cylinder wall for converting injected water into steam for a second power stroke. The fins and/or baffles in the jacket also function as a muffler for the engine.

Abstract: A paired piston engine has a rotary valve positioned above and transversely to the cylinders. The rotor of each rotary valve unit has three passages associated with three ports in the pressure pieces at the sides of the rotors. One passage/port arrangement opens and closes the intake. A second passage/port arrangement opens and closes the exhaust. The third passage/port arrangement opens and closes a second exhaust or second intake. As a result, the engine is a six cycle engine (third passage/port as a second exhaust) or a stratified charge engine (third passage/port as a stratified charge intake).

Abstract: A reciprocating piston engine of the type including a piston reciprocal in a cylinder toward and away from an expansion chamber at one end of the cylinder and also provided with intake and exhaust valves openable and closable in timed sequence with reciprocation of the piston. The valves are closed during the compression and power strokes of the piston and the exhaust valve is opened during the third stroke of the piston toward the expansion chamber. During the fourth stroke of the piston, a readily vaporizable liquid is injected into the expansion chamber under pressure for flashing into a vapor upon being heated by the residue heat of combustion in the expansion chamber and during the fifth and sixth strokes of the piston the exhaust and intake valves, respectively, are open to exhaust the vaporized liquid therefrom and intake a fresh combustible mixture of air and fuel into the expansion chamber and cylinder prior to compression of the mixture on the next stroke of the piston toward the expansion chamber.