Abstract: In a combustion chamber structure in a direct injection type diesel engine, in order to prevent flames from flowing out to a quench zone Q from a combustion chamber (32) which opens to a top part (30a) of a piston (30) to thereby prevent cooling of the flames and also in order to prevent a fuel spray from being concentrated on a lower portion of the combustion chamber (32), the fuel spray should be reflected in the combustion chamber (32) effectively according to displacement of the piston (30) to allow it to be mixed with air sufficiently in the combustion chamber (32) or in a cylinder (28), and to this end there are provided a guide wall (34) which becomes larger in inside diameter downwardly from an opening edge portion (33) of the combustion chamber (32), as well as fuel reflection walls (36, 38) which project below the guide wall (34) toward a central axis (lo) of the combustion chamber (32) and divide the combustion chamber vertically into a first combustion chamber (44) and a second combustion chamber

Abstract: According to the method of the present invention for judging the state of operation of an intake passage pressure detecting device for an engine, first at the time of starting control the intake passage pressure detecting device is regarded as being in a state of failure, then an initial output from the intake passage pressure detecting device is stored, and in case the difference between this stored initial output and a subsequent output from the intake passage pressure detecting device exceeds a predetermined value, it is judged that the intake passage pressure detecting device is in a state of normal operation. Consequently, the state of operation of the above intake passage pressure detecting device can be judged with high reliability, and the reliability of the entire system can be improved to a large extent.

Abstract: An idling controller for a variable displacement engine which is capable of operating either in a partial-cylinder or an all-cylinder mode by varying the number of cylinders in operation. When the engine runs at idle, the idling controller assures optimum operation for either cylinder operating mode by varying the quantity of air intake according to the number of cylinders in operation, providing an improvement in both fuel mileage and strating performance, one or the other of which has had to be sacrified conventionally.

Abstract: In a multi-cylinder internal combustion engine having a plurality of cylinders which are supplied with air via one common throttle valve and a control unit for regulating the number of operating cylinders which suspends the operation of an arbitrary number of cylinders by intercepting the air supply to said cylinders, it is noted at a point the output of the engine under Z.sub.1 -cylinder operation coincides with the output under Z.sub.2 -cylinder operation at the same degree of opening of the throttle valve at a given constant rate of engine rotation. Based on such a fact, the multi-cylinder internal combustion engine is made capable of shifting to and from Z.sub.1 -cylinder operation and Z.sub.2 -cylinder operation in the proximity of said point where these outputs coincide. This way, there will be no fluctuation in the output nor shock at the time of switching, and the control unit for this purpose can be made simple in construction.

Abstract: In a multi-cylinder internal combustion engine having a plurality of cylinders which are supplied with air via one common throttle valve and a control unit for regulating the number of operating cylinders to rest an arbitrary number of cylinders by blocking the air supply to said cylinders, the output of the engine under Z.sub.1 -cylinder operation is known to come to coincide with the output under Z.sub.2 -cylinder operation at one point with the same degree of opening of the throttle valve under a given constant rate of the engine rotation. At such a point, the pressure of the intake manifold under both the Z.sub.1 -cylinder operation and the Z.sub.2 -cylinder operation remain at or close to a certain value respectively over a wider range of rotation of the engine. This multi-cylinder internal combustion engine enables smooth switching between the Z.sub.1 -cylinder operation and the Z.sub.

Abstract: A fuel feed device for an engine comprises an electric control to control opening and closing of a fuel injection valve in accordance with electric signals output from an operating condition detector prior to the electric signals from an air flow rate detecting device, when the engine is operated under a specific driving condition such as a low speed and high load driving condition. Another electric control can control opening and closing of the fuel injection valve in accordance with the electric signal output from the air flow rate detecting device when the engine is under other driving conditions, so that the present invention has the advantage that highly reliable electronically controlled fuel feed is effected.

Abstract: An internal combustion engine comprising a combustion chamber, an injection chamber connected thereto through an injection port, a secondary inlet passage opening to the injection chamber, and a secondary inlet valve for opening and closing the secondary inlet passage. A spark plug extends into the combustion chamber with the spark gap of the plug close to the injection port. At the suction stroke of the engine, air in the injection chamber is injected near to the spark gap through the injection port to blow away the combustion gas around the gap and also to generate a strong swirl and turbulence of the mixture in the combustion chamber, thereby improving firing and combustion of the lean mixture in the combustion chamber to reduce the discharge of noxious components in the exhaust gas and to improve the fuel consumption.

Abstract: A fuel feed device for an engine capable of electronically controlling the fuel feed rate corresponding to the suction air flow rate in the intake passage, comprising an air flow rate detecting device for generating electric signals of frequencies proportional to suction air rate, a plurality of electromagnetic valves with a different fuel passage section from one another disposed at a suitable position in the intake passage and adapted so as to permit supplying through a fuel pressure regulator the fuel of a fixed pressure differential with the suction pressure near a fuel outlet, and an electric control means for driving the electromagnetic valves selectively in synchronism with or to follow the frequency of the electric signals or a divided frequency thereof in accordance with the engine operating condition. Thus an accurate and highly reliable fuel supply is achieved over a wide range of engine operating condition from idling to maximum speed operation.

Abstract: A fuel feed device for an engine capable of electronically controlling the fuel feed rate corresponding to the suction air flow rate in the intake passage, comprising an air flow rate detecting device for generating electric signals of frequencies proportional to suction air rate, a plurality of electromagnetic valves disposed at a suitable position in the intake passage and adapted so as to permit supplying through a fuel pressure regulator the fuel of a fixed pressure differential with the suction pressure near a fuel outlet, and an electric control means for driving the electromagnetic valves with a shifted phase with one another to control the respective opening times thereof in accordance with the engine operating condition. Thus the accurate and highly reliable fuel supply is achieved over the wide range of engine operating condition from the idling to the maximum speed operation.

Abstract: An internal combustion engine comprising a combustion chamber, an injection chamber connected thereto through an injection port, a secondary inlet passage opening to the injection chamber, and a secondary inlet valve for opening and closing the secondary inlet passage. A spark plug is extended into the combustion chamber so as to dispose a spark gap of the plug close to the injection port. At the suction stroke of the engine, air in the injection chamber is injected near to the spark gap through the injection port to blow away the combustion gas around the gap and also to generate a strong swirl and turbulence of the mixture in the combustion chamber, thereby improving firing and combustion of the lean mixture in the combustion chamber to reduce the discharge of noxious components in the exhaust gas and improve the fuel consumption.

Abstract: An internal combustion engine has a combustion chamber which communicates via an injection port with an injection chamber whose volume is 0.5 cc.about.1.5 cc. During the intake stroke, air-fuel mixture is introduced from an intake port into the combustion chamber, and at the same time, under the influence of high vacuum produced in the combustion chamber, a jet stream of exhaust gas, air or air-fuel mixture is violently injected from the injection port into the combustion chamber via an auxiliary intake passage communicates with the injection chamber through an auxiliary intake valve, so that the jet stream enhances the ignitability by scavenging burned gases from around a spark gap and also generates strong swirl and turbulence of air-fuel mixture in the combustion chamber.

Abstract: An auxiliary charge of air, fuel mixture, and/or recycled exhaust gas is injected into the combustion chambers of an engine through directional ports adjacent the spark plug gaps to enhance combustion, reduce noxious emissions, scavenge exhaust gases, etc. The injection timing is controlled by cam driven valves, and the magnitude thereof is regulated in accordance with both engine temperature and throttle valve opening or engine load, the latter being sensed by vacuum passages adjacent the throttle in the carburetor throat or by a direct coupling to the throttle valve.

Abstract: An exhaust gas recirculation system comprising an exhaust gas recirculation passage means between an exhaust gas passage and an intake passage, first and second flow control valves provided in the recirculation passage means in parallel relationship with each other for regulating flows of the exhaust gas in response to two kinds of vacuum having different characeristics, and a third flow control valve provided in the recirculation passage means in series with said first and second valves for regulating a flow of the gas in response to opening of a throttle valve of a carburetor, thereby obtaining the appropriate amount of exhaust gas recirculation in light and medium loaded driving ranges.

Abstract: In an internal combustion engine, an injection hole is provided in the cylinder head to inject narrow streams of air towards the spark gap, particularly during idling and low load running conditions. The injected air is 5 to 30% by weight of the intake fuel-air mixture provided via the intake manifold and creates a swirl or turbulence thereby increasing combustibility. The hole is connected via a sub intake passage to the main air intake passage upstream of the venturi in the carburetor or between the venturi and throttle valve.

Abstract: A crank chamber in a multicylinder-engine is divided by division walls into a plurality of spaces each of which contains one set of cranks fixed to a crankshaft, and in which varying air pressure is developed. The air under such pressure flows into a pressure chamber of an air-pump, as power source to drive the pump; suitably compressed air is produced in a pump chest of this air-pump. This air can be supplied to an exhaust gas passage for recombustion of incompletely oxidized combustive gas in the exhaust gas.

Abstract: An improved multi-cylinder internal combustion engine for producing cleaner exhaust gas. The engine has a novel fuel gas intake device in which a lean mixture gas having an air-to-fuel ratio of about 16-20 is fed almost uniformly to all the cylinders by means of a carburetor, and some of the cylinders are provided with a fuel addition passageway to supply an appropriate amount of additional fuel in accordance with various operation conditions of the engine in response to an opening angle and abrupt opening of a throttle valve of the carburetor so that a rich mixture gas having an air-to-fuel ratio of about 12-14 may be fed to such cylinders, whereby the amount of harmful gases, such as HC, CO and NO.sub.x in the exhaust, can be effectively reduced.