Abstract: A helically-shaped intake port comprising a helical portion and an inlet passage portion which is tangentially connected to the helical portion and extends so as to be slightly curved. The intake valve is arranged at the outlet open end of the helical portion. The first side wall of the inlet passage portion, which is located near the axis of the intake valve, has on its upper portion an inclined wall portion which is arranged to be directed downwards. The inlet passage portion has an open inlet end formed on the flat side wall of the cylinder head. The inlet passage portion is so arranged that the longitudinal axis thereof obliquely intersects with a straight line passing through the center of the valve head of the intake valve and extending parpendicular to the outer side wall of the cylinder head. The inlet end of the inlet passage portion is arranged at a position remote from the straight line so that the inlet end does not include the straight line.

Abstract: A throttle valve is positioned at the entrance to a swirl type of suction passage near to the corresponding intake valve of a cylinder in an internal combustion engine. The valve is designed so that when it is opened only slightly (e.g. 30.degree.-40.degree.), the flow of intake gas passing therethrough converges to flow eccentrically along one side of the suction passage. This arrangement provides full control of the intake gas in the suction passage before it reaches the combustion chamber, even when the volume of flow is small, thereby producing an effective swirl within the combustion chamber for all operating conditions of the engine.

Abstract: A fuel supplying device for use in fuel injection type internal combustion engine. The device has a fuel metering device operatively connected to an air valve device disposed in the air horn upstream of a throttle valve, fuel supplying means adapted to supply the fuel at a constant supplying pressure to the fuel metering device, a constant differential pressure valve arranged to maintain a predetermined differential pressure across the fuel metering device, and an injector for discharging the metered fuel into the air horn in the vicinity of the throttle valve. The constant differential pressure valve includes a diaphragm type valve arranged to sense and amplify differential pressure across the fuel metering device, and a variable orifice type flow control device arranged to charge flow resistance of the metered fuel.

Abstract: A multi-cylinder engine comprising an intake manifold forming therein a main and an auxiliary intake passage, which are equipped with a main and an auxiliary carburetor, respectively. A second throttle valve is provided for each cylinder. Each of the secondary throttle valves is arranged in the respective manifold branch forming therein the main intake passage. Each of auxiliary branch intake passages branched off from the auxiliary intake passage opens into the respective intake port at a position near the intake valve. A primary throttle valve is arranged in the auxiliary intake passage and opened in accordance with increase in level of the load of an engine. The secondary throttle valves are opened after the opening degree of the primary throttle valve is increased beyond a predetermined opening degree.

Abstract: A multi-cylinder internal combustion engine having an intake manifold equipped with a variable venturi type carburetor. A secondary throttle valve is provided for each cylinder. Each of the secondary throttle valves is arranged in the respective manifold branch. An auxiliary intake passage is branched off from the collecting portion of the intake manifold and connected to a distribution channel formed in the cylinder head. Each of the intake ports is connected to the distribution channel via a corresponding channel branch which opens into the intake port at a position near the intake valve. A primary throttle valve is arranged in the auxiliary intake passage and opened in accordance with an increase in level of the load of an engine. The secondary throttle valves are opened after the opening degree of the primary throttle valve is increased beyond a predetermined opening degree.

Abstract: A fuel supply apparatus for internal combustion engines of a type including an air valve disposed in an intake conduit of the engine upstream of a throttle valve. A sensor is used for sensing the pressure in an air pressure chamber defined within the intake conduit between the air valve and the throttle valve and a feedback control unit is used for controlling the air valve in response to the pressure sensed by the sensor in order to maintain the pressure in the air pressure chamber at a preset value. A fuel flow metering valve is disposed in a fuel feed channel leading from a source of fuel under pressure to the intake conduit and the metering value is interlocked with the air valve in such a manner that the opening degree of the fuel metering valve is in proportion to that of the air valve.

Abstract: A multi-cylinder internal combustion engine having a plurality of cylinders, each comprising a combustion chamber and an accumulation chamber which are interconnected to each other via an accumulation valve. The accumulation chambers are interconnected to each other via a common connecting passage. The opening operation of the accumulation valve is controlled so that the accumulation valve remains opened during the compression stroke. In the first half of the compression stroke, a jet of the combustible mixture is spouted out into the combustion chamber from the accumulation chamber to create a strong swirl motion in the combustion chamber. In the latter half of the compression stroke, the combustible mixture in the combustion chamber flows into the accumulation chamber to accumulate the combustible mixture under high pressure, which is spouted out into the combustion chamber at the next cycle.

Abstract: In a fuel supply apparatus for an internal combustion engine, a fuel discharging apparatus includes a fuel discharge port opened in an air intake conduit and a fuel valve for injecting a controlled quantity of fuel into the air intake passage through the discharge port. An annular fuel whirling chamber is formed around the fuel valve to receive fuel flow in a tangential direction to cause the fuel flow to whirl within the annular chamber. On the other hand, an annular recess is formed in a passage communicating the discharge port and the fuel valve with each other to forcively feed air to the fuel flowing through the passage. The fuel is thus intensively mixed with air and can be easily atomized upon being injected into the air intake passage through the discharge orifice.

Abstract: A fuel supply apparatus for an internal combustion engines comprises a throttle valve disposed in an intake conduit leading to the internal combustion engine, an air valve disposed in the intake conduit upstream of the throttle valve so as to define an air pressure chamber in the intake conduit in cooperation with the throttle valve, a device for controlling the air valve in response to the pressure prevailing in the air pressure chamber so that the pressure be maintained at a substantially constant level, and a fuel metering device including a variable throttle passage provided in a fuel feed conduit opening in the intake conduit through a fuel injection valve and interlocked with the air valve to be controlled so that the flow section area of the throttle passage may be proportional to the opening degree of the air valve, and a device for maintaining difference in pressure produced across the variable throttle passage at a predetermined value.

Abstract: An air-fuel ratio control apparatus for an internal combustion engine has an air valve disposed in an intake passage downstream of a throttle valve to cooperate therewith to define an air pressure chamber and operative to maintain a substantially constant pressure therein. A fuel circuit includes a fuel discharge port open to the intake passage and a fuel-metering orifice operatively associated with the air valve such that the fuel-flowing section of the orifice is varied in proportion to the air-flowing section of the air valve. A constant differential fuel pressure valve is disposed in the fuel circuit to maintain a substantially constant fuel pressure difference across the fuel metering orifice during normal engine operation. The differential fuel pressure valve is mechanically operatively connected to a piston-cylinder assembly into which the fuel pressure upstream of the fuel-metering orifice is introduced.

Abstract: An internal combustion engine has a secondary air supply system and a fuel injection system including a two-fluid injection nozzle operative to inject air and fuel both under pressure into engine intake system. The secondary air supply system includes an air pump and a secondary air supply line extending between the pump and the engine exhaust system. The two-fluid injection nozzle is pneumatically connected to an air distributor provided on the secondary air supply line whereby pressurized air from the air pump is also supplied to the two-fluid injection nozzle and injected thereby together with the fuel to facilitate atomization of the injected fuel as well as to supercharge the engine.

Abstract: A fuel supply apparatus for an internal combustion engine comprises an air valve disposed in an intake air conduit upstream of a throttle valve and caused to rotate in accordance with the quantity of intake air through the intake conduit, a fuel supply source for supplying fuel under a substantially constant pressure through a fuel feed conduit to a fuel discharge port opened to the intake conduit, and a fuel metering device including a variable slit provided in the fuel feed conduit and interlocked with the air valve to be controlled such that the flow area of the variable slit may be proportional to the quantity of intake air and a fuel differential device for maintaining pressure difference across the variable slit at a predetermined value.

Abstract: An air-fuel ratio controlling system for a fuel-injection type internal combustion engine has an air valve disposed in an air intake duct upstream of a throttle valve and a fuel-metering variable orifice disposed in a fuel circuit. The air valve and the fuel-metering variable orifice are operatively associated with each other and controlled normally to maintain the air-fuel ratio at a substantially constant value. Pressurized fuel is used as a working fluid to operate the air valve. O.sub.2 sensor detects the oxygen content of exhaust gases to actuate a valve which varies the pressure of the working fluid to change the degree of opening of the air valve whereby the air-fuel ratio is adjusted in accordance with the output of the O.sub.2 sensor.

Abstract: Disclosed is an internal combustion engine comprising a main chamber and an auxiliary chamber which are interconnected to each other via a connecting passage. The spark plug is located in the deep interior of the auxiliary chamber remote from the main chamber. The connecting passage comprises a first open end opening into the deep interior of the auxiliary chamber, and two second open ends opening into the main chamber. When the piston reaches the top dead center position, the main chamber defines therein two spaces having approximately equal volumes and including the corresponding second open ends. The second open ends are directed to the centers of the corresponding spaces.

Abstract: An internal combustion engine having a main combustion chamber, an auxiliary combustion chamber having inlet and outlet ports through which the auxiliary combustion chamber is communicated with the main combustion chamber, an intake port for supplying a lean air/fuel mixture to the main combustion chamber and an auxiliary passage disposed in the intake port for supplying a rich air/fuel mixture. A cylinder head of the engine has a cylindrical recess connecting with the intake port so as to enable the mixtures to flow through the intake port and the recess into the combustion chambers. An intake valve is adapted to seat, at the closed position, a on value seat disposed at the bottom of the recess. The auxiliary combustion chamber is communicated through the inlet port with the recess so that the rich air/fuel mixture is effectively conducted into the auxiliary combustion chamber through the inlet port when the intake valve is at the partially open position and is still positioned within the residual recess.

Abstract: An auxiliary combustion chamber at least partially embedded in the cylinder head of an internal combustion engine adjacent the intake valve of a main combustion chamber and having a spark plug positioned in the auxiliary chamber and unvalved inlet and outlet ports interconnecting the auxiliary chamber with the main chamber. The air/fuel mixture drawn into the main combustion chamber is deflected by the back surface of the intake valve into the inlet port of the auxiliary combustion chamber toward the spark plug. The auxiliary combustion chamber may include a shell positioned in a cavity in the cylinder head with devices for properly positioning the shell in the cavity and for retaining the shell and preventing it from rotating.

Abstract: An auxiliary combustion chamber at least partially embedded in the cylinder head of an internal combustion engine adjacent the intake valve of a main combustion chamber and having a spark plug positioned in the auxiliary chamber and unvalved inlet and outlet ports interconnecting the auxiliary chamber with the main chamber. The air/fuel mixture drawn into the main combustion chamber is deflected by the back surface of the intake valve into the inlet port of the auxiliary combustion chamber toward the spark plug. The auxiliary combustion chamber may include a shell positioned in a cavity in the cylinder head with devices for properly positioning the shell in the cavity and for retaining the shell and preventing it from rotating.

Abstract: An auxiliary combustion chamber at least partially embedded in the cylinder head of an internal combustion engine adjacent the intake valve of a main combustion chamber and having a spark plug positioned in the auxiliary chamber and unvalved inlet and outlet ports interconnecting the auxiliary chamber with the main chamber. The air/fuel mixture drawn into the main combustion chamber is deflected by the back surface of the intake valve into the inlet port of the auxiliary combustion chamber toward the spark plug. The auxiliary combustion chamber may include a shell positioned in a cavity in the cylinder head with devices for properly positioning the shell in the cavity and for retaining the shell and preventing it from rotating.

Abstract: An auxiliary combustion chamber at least partially embedded in the cylinder head of an internal combustion engine adjacent the intake valve of a main combustion chamber and having a spark plug positioned in the auxiliary chamber and unvalved inlet and outlet ports interconnecting the auxiliary chamber with the main chamber. The air/fuel mixture drawn into the main combustion chamber is deflected by the back surface of the intake valve into the inlet port of the auxiliary combustion chamber toward the spark plug. The auxiliary combustion chamber may include a shell positioned in a cavity in the cylinder head with devices for properly positioning the shell in the cavity and for retaining the shell and preventing it from rotating.

Abstract: An auxiliary combustion chamber at least partially embedded in the cylinder head of an internal combustion engine adjacent the intake valve of a main combustion chamber and having a spark plug positioned in the auxiliary chamber and unvalved inlet and outlet ports interconnecting the auxiliary chamber with the main chamber. The air/fuel mixture drawn into the main combustion chamber is deflected by the back surface of the intake valve into the inlet port of the auxiliary combustion chamber toward the spark plug. The auxiliary combustion chamber may include a shell positioned in a cavity in the cylinder head with devices for properly positioning the shell in the cavity and for retaining the shell and preventing it from rotating.