Abstract: An auxiliary chamber injection port providing communication between a main combustion chamber and an auxiliary combustion chamber has its axis composed of a combination of a straight line and an arc in a manner to satisfy the following relationships: .theta..sub.1 <.theta..sub.2 ; 20.degree..ltoreq..theta..sub.1 .ltoreq.45.degree.; and 35.degree..ltoreq..theta..sub.2 .ltoreq.67.5.degree., if the outflow angle of the axis of said auxiliary chamber injection port at the open end at the side of said auxiliary combustion chamber is designated at .theta..sub.2 with respect to a plane normal to the center line of said auxiliary combustion chamber and if the outflow angle of the axis of said auxiliary chamber injection port at the open end at the side of said main combustion chamber with respect to a plane normal to the center line of said auxiliary combustion chamber is designated at .theta..sub.1.

Abstract: A diesel particulate filter system for treating the exhaust gas of a diesel engine which is small in size and inexpensive. The system includes a particulate filter connected in a gas line from the engine, a burner, including an ignition plug, connected at a point upstream of the particulate filter and which is supplied with fuel, a primary air flow for atomizing the fuel, and a secondary air flow for burning the particulates trapped in the particular filter and which supplies the particulate filter with a hot burning gas produced by the ignition plug. Primary and secondary pumps supply, respectively, the primary and secondary air flows. A single motor drives both the primary and secondary air pumps. The ignition plug and motor are controlled so that when the amount of particulates trapped in the filter exceeds a preset level, the ignition plug and motor are activated to clean the filter by burning the particulates in the burner.

Abstract: An internal combustion engine comprising a main intake passage supplying air-fuel mixture to a combustion chamber, an auxiliary intake passage supplying air or an air-fuel mixture to the combustion chamber through an injection port, a fuel supplement passage for supplementally supplying fuel to the auxiliary intake passage, a solenoid valve provided in the fuel supplement passage, and a control device for controlling opening and closing of the solenoid valve in response to a signal from an oxygen sensor disposed in an exhaust passage, said solenoid valve controlling supply of fuel to the auxiliary intake passage, thereby regulating an overall air-fuel ratio of the mixture supplied to the combustion chamber approximately to a stoichiometric air-fuel ratio.

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 secondary intake gas control system for an internal combustion engine having a secondary intake gas supply means for supplying air or a lean mixture to a combustion chamber, comprising an air control valve means provided in a secondary intake passage means of the secondary intake gas supply means to control a supply of the air. The air control valve means comprises a valve member and actuating means therefor. The actuating means is operated by means for sensing a temperature of the engine and means for sensing an opening degree of a throttle valve to open the valve member to communicate the secondary intake passage means with atmosphere when the opening degree of the throttle valve is above predetermined value at a predetermined temperature range of the engine during warming-up thereof.

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: 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 multicylinder engine comprising at least one first cylinder, a corresponding number of second cylinder, and a carburetor to supply a fuel-air mixture leaner than stoichiometric to all the first and second cylinders. When required by the driving range and other driving conditions, a rich mixture is supplied to the second cylinder to lower the air-fuel ratio in it for the purpose of exhaust emission purification, while the first cylinder is being supplied with the lean mixture.

Abstract: A carburetor system for us in a multicylinder engine comprises a carburetor having a main fuel-air mixture supply device to supply a mixture leaner than stoichiometric to at least one first cylinder and a corresponding number of second cylinder. A rich mixture supply device, integrated into the carburetor, has a rich mixture forming passage to make a mixture richer than stoichiometric. The main mixture supply device communicates with the first and second cylinders by a first passage, while the rich mixture forming passage with the second cylinder by a second passage. A first, second and third valves are provided in the first, second and rich mixture forming passages, respectively. These valves respectively are opened and closed by a first, second and third valve actuation devices, which are in turn regulated by an operation control device. Depending on the engine operating range and driving conditions, this carburetor system supplies a rich mixture to the second cylinder to raise the fuel-air ratio in it.

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.