Abstract: A two-stroke engine is provided comprising at least one cylinder (1) in which is slidingly mounted a piston (2) which defines in this cylinder a combustion chamber (C) and a precompression chamber (P), the lateral cylindrical wall of the cylinder being provided with at least two ports closable by the piston (2), namely at least one transfer port (3) through which opens a transfer channel (4) connecting the two chambers together and at least one exhaust port (5) communicating with an exhaust pipe (6). These two ports are arranged and disposed so that the opening of the transfer port (3) begins before that of the exhaust port (5) and special means are provided for making the pressure of the fresh gases admitted into the combustion chamber (C) through the transfer port (3), during opening of this transfer port, sufficiently high with respect to that of the burnt gases then present in the combustion chamber.

Abstract: In an EGR control system for a diesel engine, the EGR amount is controlled by controlling the pressure in a diaphragm chamber of an EGR valve using the output signal of a computer, responsive to signals from a plurality of engine running condition sensors, for calculating the EGR amount with corrections according to the engine running conditions and the excess air rate. In some cases, the EGR is carried out only when the rotational speed of the engine is higher than a predetermined rotational speed. Also, in some cases, the EGR is carried out when an occurrence of idling is detected, even if the rotational speed of the engine is lower than the predetermined rotational speed.

Abstract: In a diesel engine exhaust gas recirculation system wherein an exhaust gas recirculation control valve operated by an operating air pressure controls the flow resistance of the exhaust gas recirculation passage according to variation of the operating air pressure effected by an operating air pressure control valve according to the load on the engine so as to replace most of the excess air part of the intake air by recirculated exhaust gases, an atmospheric pressure responsive air pressure control valve is provided so as to supply an air pressure which has been beforehand controlled so as to compensate for such changes of atmospheric pressure as caused by changes of altitude to the operating air pressure control valve as an operating air pressure source.

Abstract: A slosh baffle for selective and retroactive installation in the oil pan of an in-line internal combustion engine for automotive vehicles, the slosh baffle being attachable to the rim of the oil suction strainer by snap-action assembly, its transverse orientation being determined by means of a saddle portion on the slosh baffle which engages an elbow of the oil suction line. Attachment to the strainer rim is obtained by means of several downwardly depending flexible snap hooks on the periphery of a supporting flange of the slosh baffle, in cooperation with separate centering lugs.

Abstract: An exhaust gas recirculation control system which is adapted to control the valve opening of the exhaust gas recirculation valve so as to minimize the difference between a detected value of the valve opening of the above value and a command value determined as a function of operating conditions of the engine. The valve opening is corrected at a higher speed when the above difference has a larger absolute value, and at a lower speed when the difference has a smaller absolute value, to ensure prompt and accurate control of the exhaust gas recirculation quantity.

Abstract: In an electronic fuel supply control system for an internal combustion engines, the fuel quantity being supplied to the engine is set to different values in accordance with the operating condition of the engine, between when the exhaust gas recirculation is operated and when it is not operated, for achieving proper air/fuel ratios. Further, immediately after a valve lift command is outputted at full closing of the exhaust gas recirculation valve, which is indicative of opening of the valve, a quantity of fuel set as applicable when the exhaust gas recirculation is not operated is supplied to the engine until the actual valve opening increases to a predetermined value. Immediately after a valve lift command is outputted at opening of the valve, which is indicative of full closing of the valve, a quantity of fuel set as applicable when the exhaust gas recirculation is operated is supplied to the engine until the actual valve opening decreases to a predetermined value.

Abstract: A method and an apparatus for controlling EGR in a diesel engine according to the present invention used an EGR valve having a diaphragm chamber, a pressure supplying device for supplying air pressure to the diaphragm chamber, an adjusting device for adjusting the air pressure corresponding to the rotation angle of a rotary shaft for controlling the amount of fuel injected, a rotation rate detector of the engine, and a pressure releasing device for releasing a portion of the negative pressure in said diaphragm chamber. In the method and apparatus, a portion of the negative pressure in the diaphragm chamber is released to an atmospheric pressure corresponding to the rotation rate of the engine. Thus, the rate of EGR is decreased in accordance with an increase in the rotation rate in an operating condition higher than a predetermined rotation rate.

Abstract: A fuel injection control method and system for a crankcase compression two cycle engine wherein the amount of fuel discharge is controlled by the pressure in the crankcase.

Abstract: An E.G.R. control system for a diesel engine is disclosed wherein a deterioration in combustion is avoided upon depressing an accelerator pedal for reacceleration after the momentary release of the accelerator pedal. An E.G.R. control unit is responsive to a load indicative signal from a load sensor and a revolution signal from a revolution sensor and generates an engine operating state indicative signal indicating that the engine operates in low load state which requires high E.G.R. flow rate. A monostable circuit, a delay circuit and a logic circuit make up a circuit means for preventing a throttle valve from being closed until the engine keeps operating in the low load state for a time longer than a predetermined time.

Abstract: In an apparatus for controlling the EGR in a diesel engine, a single pressure control valve adjusts the control pressure from a pump automatically when the pressure changes, and supplies the control pressure in response to the command signal of a control circuit to an EGR valve and a waste-gate valve of a turbocharger. The pressure control valve includes an electric actuator, a spool valve, a sleeve, a diaphragm, and a spring. By using this apparatus, a diesel engine which has a high response speed, high control precision, simple constitution, less nitrogen oxides in the exhaust gas, and low manufacturing cost is obtained.

Abstract: A two-cycle, gas-powered engine which is capable of operating over a wide range of loads including those (e.g. idle speed) which have previously caused misfirings in known engines of this type. A specially constructed head and piston assembly and a governor-controlled fuel system are incorporated into an otherwise typical two-cycle engine to convert the engine into a stratified charge engine. The head and piston assembly is constructed to provide an ovate-domed, flat-bottomed combustion chamber therebetween when the piston is in a top dead center position in the cylinder. This combustion chamber allows fuel injected in the top of the combustion chamber to mix with air being compressed by the piston to provide a rich stratified charge around the ignition means (e.g. spark plugs) which are also positioned near the top of the chamber. This charge is always rich enough to support rapid ignition and to quickly spread burning to the weaker, exhaust-contaminated mixture present in the lower combustion chamber.

Abstract: A 2-stroke engine having a combustion chamber and a scavenge port which is open to the combustion chamber. When the engine is operating under a light load in which a large amount of unburned components, incompletely burned components and oxygen remains in the combustion chamber, fresh air is fed into the combustion chamber from the scavenge port at a low speed so that the fresh air does not disturb the residual gas in the combustion chamber. As a result of this, oxidation of the unburned components and the incompletely burned components continues without interruption during the expansion stroke and the compression stroke and causes self-ignition of the residual gas at the end of the compression stroke. The self-ignited residual gas causes ignition of the fuel injected into the combustion chamber from a fuel injector.

Abstract: In an internal combustion engine having an intake passage provided therein with a throttle valve for controlling intake flow of air or an air-fuel mixture passing therethrough toward engine cylinders and an exhaust passage, an exhaust gas recirculation system comprises first means for conducting a portion of the exhaust gases from the exhaust passage into the intake passage downstream of the throttle valve and second means provided in the intake passage downstream of the throttle valve for preventing the exhaust gases fed through said first means from flowing upstream toward the throttle valve. Accordingly, the response accuracy of the throttle valve is protected from being impaired due to deposition of exhaust gas contaminants thereon.

Abstract: In an exhaust gas recirculation system including a recirculation passage to provide a communication between an intake pipe and an exhaust pipe of an internal combustion engine, a flow control valve associated with a pneumatic servomotor to control the quantity of exhaust gas flowing through the recirculation passage in accordance with the pneumatic pressure applied to the servomotor, and first and second electrically operated valves to selectively apply negative pressure and the atmospheric pressure to the servomotor, a digital computer is adapted to calculate a desired opening degree of the flow control valve in response to an electric signal indicative of operating conditions of the engine, to calculate each energization time of the valves defined by a difference between the actual opening degree of the flow control valve and the calculated value in response to an electric signal indicative of the actual opening degree of the flow control valve, and to generate an output signal indicative of the calculated

Abstract: A vacuum modulating chamber of a vacuum control valve is communicated with a diaphragm chamber of a EGR valve for controlling an amount of exhaust gas to be recirculated into combustion chambers of an engine, so that a modulated negative pressure is applied thereto. The chamber is provided with a diaphragm deflected responding to the negative pressure in the chamber. The vacuum control valve is further provided with a cam member and a spring which urges the diaphragm in one direction so as to change a value at which the pressure in the vacuum modulating chamber is controlled. A push rod is movably held by a cam follower and another spring is provided for urging the push rod in the above direction. The spring force of the other spring is applied to the diaphragm, when a rotational angle of the cam member exceeds a predetermined angle, so that the negative pressure is changed rapidly.

Abstract: An exhaust gas recirculation control system for a vehicle diesel engine with an exhaust gas recirculation passage, including: a fluid pressure operated exhaust gas recirculation valve which controls flow resistance of the recirculation passage according to a control fluid pressure supplied thereto so as to increase the flow resistance up to a maximum substantially infinite value as the control fluid pressure approaches atmospheric pressure; an electrically operated switching over valve, which, when actuated, changes over the control fluid pressure supplied to the exhaust gas recirculation control valve to atmospheric pressure, and an exhaust gas recirculation control signal generating system which generates the control fluid pressure supplied to the exhaust gas recirculation control valve to operate it regularly as well as an electrical signal which actuates the switching over valve when the rate of change of engine load is greater than a certain predetermined value.

Abstract: A hot slipstream from the exhaust of an internal combustion engine is used directly, that is without valving it, to heat and vaporize fuel as it is sprayed from the fuel nozzle of a carburetor having a booster venturi above the throttle plate, provided the ratio of the volume of slipstream to the volume of exhaust gases is self-regulated within narrow limits at all times during the engine's operation, in accordance with the physical considerations governing gas flow. The main jets of a conventional carburetor may be changed to provide decreased flow of gasoline by about 10% to give better mileage without sacrificing performance of the engine, and without adversely affecting the exhaust emissions which are otherwise controlled by a conventional emission control system.

Abstract: An EGR system has two vacuum modulation valves, one responsive to venturi vacuum and "EGR" pressure (which prevails just upstream of the EGR flow control valve) and the other responsive to venturi vacuum and induction vacuum. The first valve predominately dilutes the vacuum operating the EGR flow control valve during heavy load operation while the second valve predominately dilutes said vacuum during light load and/or high speed operation. With this combination, excessive EGR is avoided during said light load and high speed operations, respectively.

Abstract: An exhaust gas recirculation control system calculates a target EGR ratio value based upon engine operating parameters and maintains the EGR ratio at the target EGR ratio value. Each time the vehicle travels a predetermined distance, the control system calculates an actual EGR ratio value and corrects the target EGR ratio value to reduce a deviation between the target and actual EGR ratio values to zero.

Abstract: An apparatus for regulating the exhaust gas recycling rate in an internal combustion engine having self-ignition is proposed, in which a set-point or nominal ignition delay value is ascertained, and the actual ignition delay value is regulated to this nominal value. The nominal ignition delay value is efficaciously derived from a multi-dimensional memory, the coordinate values of which are dependent on at least load and rpm. The ignition delay time is ascertained from a comparison of the signal for the injection onset of an injection nozzle, for instance, and the signal of a pressure sensor communicating with the combustion chamber.