Abstract: An engine comprising an intake port which has a separating wall projecting downwardly from the upper wall of the intake port. The separating wall defines a helical portion, an inlet passage portion tangentially connected to the helical portion, and a bypass passage interconnecting the inlet passage portion and the helical portion. The upper wall of the bypass passage is higher than that of the inlet passage portion. A rotary valve is arranged in the bypass passage and is actuated by a vacuum-operated diaphragm apparatus. The rotary valve is opened when the amount of air fed into the cylinder of the engine is increased beyond a predetermined value.

Abstract: An engine comprising an intake port which has a separating wall projecting downwardly from the upper wall of the intake port. The separating wall defines a helical portion, an inlet passage portion tangentially connected to the helical portion, and a bypass passage interconnecting the inlet passage portion to the helical portion. A rotary valve is arranged in the bypass passage and actuated by a vacuum operated diaphragm apparatus. The rotary valve is opened when the amount of air fed into the cylinder of an engine is increased beyond a predetermined value.

Abstract: An engine comprising an intake port which has a separating wall projecting downwardly from the upper wall of the intake port. The separating wall defines a helical portion, an inlet passage portion tangentially connected to the helical portion, and a bypass passage interconnecting the inlet passage portion and the helical portion. The separating wall extends to near the side wall of the helical portion and defines a narrow passage portion therebetween. The width of the upper wall of the inlet passage portion is gradually reduced towards the narrow passage portion. A rotary valve is arranged in the bypass passage and is actuated by a vacuum-operated diaphragm apparatus. The rotary valve is opened when the amount of air fed into the cylinder of the engine is increased beyond a predetermined value.

Abstract: An engine comprising an intake port which has a separating wall projecting downwardly from the upper wall of the intake port. The separating wall defines a helical portion, an inlet passage portion tangentially connected to the helical portion, and a bypass passage interconnecting the inlet passage portion and the helical portion. The intake port has a bottom wall having a transverse width which is approximately equal to the diameter of the valve head of the intake valve. The opposed peripheral edges of the bottom wall are located on the extensions of the tanget lines of the outer periphery of the valve head of the intake valve. A rotary valve is arranged in the bypass passage and is actuated by a vacuum-operated diaphragm apparatus. The rotary valve is opened when the amount of air fed into the cylinder of the engine is increased beyond a predetermined value.

Abstract: An engine comprising an intake port which has a separating wall projecting downwardly from the upper wall of the intake port. The separating wall defines a helical portion, an inlet passage portion tangentially connected to the helical portion, and a bypass passage interconnecting the inlet passage portion and the helical portion. A rotary valve is arranged in the inlet portion of the bypass passage so that the axis of the rotary valve is substantially parallel to the axis of the stem of the intake valve. The rotary valve is actuated by a vacuum-operated diaphragm apparatus and is opened when the amount of air fed into the cylinder of the engine is increased beyond a predetermined value.

Abstract: An engine comprising an intake port which has a separating wall projecting downward from the upper wall of the intake port. The separating wall defines a helical portion, an inlet passage portion tangentially connected to the helical portion, and a bypass passage interconnecting the inlet passage portion to the helical portion. A rotary valve is arranged in the bypass passage and actuated by a vacuum operated diaphragm apparatus. The rotary valve is opened when the amount of air fed into the cylinder of an engine is increased beyond a predetermined value. The separating wall has a height which is equal to approximately half the height of the intake port in the vicinity of the rotary valve.

Abstract: An engine comprising an intake port which has a separating wall projecting downwardly from the upper wall of the intake port. The separating wall defines a helical portion, an inlet passage portion tangentially connected to the helical portion, and a bypass passage interconnecting the inlet passage portion to the helical portion. A rotary valve is arranged in the bypass passage and actuated by a vacuum operated diaphragm apparatus. The rotary valve is opened when the amount of air fed into the cylinder of an engine is increased beyond a predetermined value. A downwardly projecting rib is formed on the bottom face of the separating wall. The rib extends toward the helical portion from the rotary valve.

Abstract: An engine comprising an intake port which has a separating wall projecting downward from the upper wall of the intake port. The separating wall defines a helical portion, an inlet passage portion tangentially connected to the helical portion, and a bypass passage interconnecting the inlet passage portion to the helical portion. A rotary valve is arranged in the bypass passage and actuated by a vacuum operated diaphragm apparatus. The rotary valve is opened when the amount of air fed into the cylinder of an engine is increased beyond a predetermined value. A conical shaped groove is formed on the bottom wall of the intake port. The lower end of the rotary valve is located in the groove.

Abstract: A helically-shaped intake port comprising a helical portion formed around an intake valve, and a substantially straight inlet passage portion tangentially connected to the helical portion. A bypass passage is branched off from the inlet passage portion and connected to the helical portion. A slide valve is arranged in the bypass passage and controlled by a stepper motor so that the opening area of the slide valve changes in proportion to the amount of air to be fed into the cylinder of the engine.

Abstract: A helically-shaped intake port comprising a helical portion formed around an intake valve, and a substantially straight inlet passage portion tangentially connected to the helical portion. A bypass passage is branched off from the inlet passage portion and connected to the helical portion. A slide valve is arranged in the bypass passage and controlled by an electronic control unit so that the opening area of the slide valve is proportional to the amount of air fed into the cylinder of the engine.

Abstract: A helical type intake port is formed with the helical portion around an intake valve and the inlet portion tangentially contiguous to the helical portion.A bypass passage is provided in a cylinder head, which is branched off from the inlet portion and connected to an end portion of said helical portion. The flow in the bypass passage is controlled by a valve in response to the amount of air in the intake port so that a strong swirl flow with a slight flow resistance may be obtained at not only a low revolution and a low load, but also at a high revolution and a high load.

Abstract: A helical type intake port for an internal combustion engine. The system has a first sub-intake passageway and a second sub-intake passageway. The first sub-intake passageway is connected to a helical end of the intake passageway for generating a flow of air for suppression of the swirl effect in the helical end. The second sub-intake passageway is connected to a portion of the helical port located upstream of the helical end portion, for increasing the speed of flow of air directed to the helical end portion.

Abstract: A fuel injection type internal combustion engine comprising a cylinder head having a flat inner wall, and a piston having a flat top face. The flat inner wall and the flat top face form a squish area therebetween. A recess having a lung shaped cross-section is formed in the cylinder head. A shallow groove is formed on the flat inner wall of the cylinder head so as to extend from the intake valve to the recess. The exhaust valve is arranged on the bottom of the recess. A depression connected to the recess is formed on the shallow groove. The spark plug is arranged in the depression. The cylinder head has a portion located between the recess and the intake passage. A fuel injector is arranged in the intake passage. The nozzle of the fuel injector is directed to an inner wall portion of the intake passage, which is located near the recess.

Abstract: In an internal combustion engine, the combination of a cylinder head with a plane lower surface and a cavity, a piston with a plane upper surface and a cavity, the plane surfaces of the piston and the cylinder head cooperating to form a squish area on one side of the cylinder bore, and a spark plug protruding into the combustion chamber defined by the cavities so that its igniting tip lies substantially in the squish plane on the other side of the cylinder bore.

Abstract: A variable venturi type carburetor includes a suction chamber, a suction piston moveable into and out of the chamber, a metering needle attached to the head portion of the suction piston, the needle being faced by a metering jet. The carburetor also includes a throttle valve. The head portion confronts the venturi section at the upstream side of the throttle valve. The head portion is obliquely cut or shaped at one side, which faces the throttle valve, and desirably is so positioned relative to the throttle valve that at least a portion of the throttle valve pivots during opening movement within space vacated by the obliquely cut or shaped piston portion as the piston moves in an opening direction.

Abstract: A variable venturi type carburetor of an internal combustion engine which includes a housing, a bore extending through the housing and having an inner wall defining an intake passage, a suction piston movably mounted in the housing and having a head portion projecting into the intake passage and a fuel injection valve. The suction piston moves so as to change the cross-sectional area of the venturi portion defined between the head portion of the suction piston and an inner wall of the intake passage. A pipe member connected to the fuel injection valve is opened to the intake passage in a position opposite the head portion with regard to the intake passage. The fuel injected from the injection valve is supplied through the pipe member to the intake passage.

Abstract: A variable venturi type carburetor of an internal combustion engine which includes a housing, a bore extending through the housing and having an inner wall defining an intake passage, a suction piston movably mounted in the housing and having a head portion projecting into the intake passage and a fuel injection valve arranged at the position opposite to the head portion of the suction piston with regard to the intake passage. The suction piston moves so as to change the cross-sectional area of the venturi portion defined between the head portion of the suction piston and an inner wall of the intake passage. The head portion of the suction piston is provided with a recess which extends along a line crossing with the central axis of the suction piston and is arranged in parallel to the direction of air flowing in the intake passage.

Abstract: Disclosed is a device for injecting fuel into an intake air supply passage which is communicated with the combustion chambers of an internal combustion engine.The device comprises: a swingable throttle shaft having a hole formed therein along a longitudinal axis thereof and traversing an intake air supply passage; a throttle valve plate fixed to the throttle shaft for throttling the intake air supply passage so that the throttle valve plate can vary the opening of the air supply passage due to the swing of the throttle shaft; and a fuel injection outlet portion formed at the proximity of the surface of the throttle valve plate and communicated with one of the hole. Fuel supplied from the fuel injection outlet portion is uniformly admixed with the air flow which is caused to contract by the throttle valve plate.

Abstract: In an exhaust gas recirculation system for an internal combustion engine, a flow control valve is disposed within a recirculation pipe and operatively connected to a pneumatically operated servomotor to control the flow quantity of exhaust gases through the recirculation pipe, and an orifice is disposed within the recirculation pipe upstream of the valve to form a space between the valve and the orifice. A pressure regulator serves to modulate negative pressure from an engine intake manifold to the servomotor on a basis of pneumatic pressure applied thereto and pressure in the space. The pneumatic pressure applied to the pressure regulator is electrically controlled to satisfy the following equation.Pd=f(Pv, N)where the character Pd is the pneumatic pressure applied to the pressure regulator, and the characters Pv and N respectively indicate the negative pressure in the intake manifold and the engine speed.

Abstract: A fuel-air mixture supply system comprising a Venturi portion formed on the inner surface of a cylindrical suction system having a throttle valve therein, at least one fuel injection port provided in the Venturi portion and open into the suction system, an atomizing chamber located adjacently to the fuel injection port in a co-axial manner to the fuel injection port and having a nozzle to make the atomizing chamber communicate with the fuel injection port, a fuel injection valve connected to the cylindrical suction system to inject the fuel into the atomizing chamber at a predetermined pressure and an air bleed passage making the portion above the throttle valve in the suction system communicate with the atomizing chamber. The fuel injected into the atomizing chamber from the fuel injection valve is atomized by the air drawn into the chamber from the suction system through the air bleed passage.