Provided is an air leading type stratified scavenging two-stroke internal combustion engine including an air passage configured to allow supply of air to a scavenging passage configured to allow communication between a crank chamber and a combustion chamber, at least one sensor configured to detect an operating condition of an engine, and a fuel valve configured to control fuel supply to the air passage based on detection performed by the at least one sensor. The fuel supply to the air passage is controlled by the fuel valve at times other than start and idling of the engine or at needed times in addition to the start or the idling of the engine.

Provided is an air leading type stratified scavenging two-stroke internal combustion engine including an air passage configured to allow supply of air to a scavenging passage configured to allow communication between a crank chamber and a combustion chamber, at least one sensor configured to detect an operating condition of an engine, and a fuel valve configured to control fuel supply to the air passage based on detection performed by the at least one sensor. The fuel supply to the air passage is controlled by the fuel valve at times other than start and idling of the engine or at needed times in addition to the start or the idling of the engine.

A combustion engine having a crankcase and a cylinder, wherein a piston is guided to be movable in strokes inside cylinder, piston movably limiting a combustion chamber, and wherein in cylinder at least one transfer port is inserted, which extends between crankcase and combustion chamber, and through which an ignition mixture can flow from crankcase into combustion chamber, and which opens out into combustion chamber in an upper discharge area in such a way that ignition mixture preferably does not reach transfer ports and thus the crankcase, while at the same time a direct connection of crankcase to combustion chamber is maintained via a transfer port, which is as short as possible, it is suggested that at least one storage chamber is provided which is connected to upper discharge area and in which exhaust gas flowing from the combustion chamber into discharge area can be temporarily stored.

A combustion engine having a crankcase and a cylinder, wherein a piston is guided to be movable in strokes inside cylinder, piston movably limiting a combustion chamber, and wherein in cylinder at least one transfer port is inserted, which extends between crankcase and combustion chamber, and through which an ignition mixture can flow from crankcase into combustion chamber, and which opens out into combustion chamber in an upper discharge area in such a way that ignition mixture preferably does not reach transfer ports and thus the crankcase, while at the same time a direct connection of crankcase to combustion chamber is maintained via a transfer port, which is as short as possible, it is suggested that at least one storage chamber is provided which is connected to upper discharge area and in which exhaust gas flowing from the combustion chamber into discharge area can be temporarily stored.

A dual fuel carburetor includes a carburetor body, a main jet pipe and a float chamber housing to form a float chamber, the needle valve device includes a pushing needle and a needle valve base, the pushing needle is movably inserted in the float chamber housing, and a window is formed at a bottom of the float chamber housing, the needle valve device further includes a sealed corrugated sleeve positioned around the pushing needle, which has a first end hermetically connected with the pushing needle and a second end hermetically connected with the float chamber housing, a driving spring is positioned around the pushing needle, and the pushing needle has a driving end extended out from the float chamber housing and opposite to that end cooperated with the valve base hole. The needle valve device is in a reasonable design to obtain mechanical controls or other automated drive controls.

An exhaust valve assembly for a two-stroke internal combustion engine has a valve actuator, and a two-part valve having a primary and secondary valves defining first and second decompression passages respectively. The primary valve is operatively connected to the valve actuator. The primary valve is in first, second and third primary valve positions when the valve actuator is in first, second and third actuator positions respectively. The secondary valve is in a first secondary valve position when the valve actuator is in the first or the second actuator position and in a second secondary valve position when the valve actuator is in the third actuator position. The first and second valve decompression passages fluidly communicate with each other when the valve actuator is in the second actuator position, and are fluidly separate from each other when the valve actuator is the first or the third actuator position.

A two-stroke internal combustion engine includes a diversion fin and an allowance slot. The diversion fin is a structure that has flanges at two ends and a rectangular longitudinal cross section profile. The diversion fin is clamped by a cylinder head and a cylinder block. The diversion fin extends along the diameter direction of the cylinder head and is positioned between an air inlet channel and an air exhaust channel. The diversion fin separates the air inlet channel from the air exhaust channel. The upper end of the diversion fin is provided with a transverse through groove at a position corresponding to an oil nozzle of an oil injector. The allowance slot is disposed on a piston and is positioned in the center of a combustor. The position of the allowance slot corresponds to the position of the diversion fin.

A two-stroke internal combustion engine includes a diversion fin and an allowance slot. The diversion fin is a structure that has flanges at two ends and a rectangular longitudinal cross section profile. The diversion fin is clamped by a cylinder head and a cylinder block. The diversion fin extends along the diameter direction of the cylinder head and is positioned between an air inlet channel and an air exhaust channel. The diversion fin separates the air inlet channel from the air exhaust channel. The upper end of the diversion fin is provided with a transverse through groove at a position corresponding to an oil nozzle of an oil injector. The allowance slot is disposed on a piston and is positioned in the center of a combustor. The position of the allowance slot corresponds to the position of the diversion fin.

A two-stroke engine includes: a scavenging port communicating with a crank chamber and a side portion of a cylinder, and switchably brought into communication with or shut off from the cylinder by a piston; and multiple fuel injection valves for injecting fuel into the scavenging port. Since the fuel injection valves inject fuel into the scavenging port, there is no need to apply a high pressure injection system. By causing the start of fuel injection to be delayed from a timing at which the scavenging port is opened, fresh air is sent into the cylinder at an early stage of scavenging, and air-fuel mixture is sent into the cylinder at a late stage of scavenging. Thereby, even in a long-stroke engine, stratified scavenging is performed to suppress blow-by of air-fuel mixture.

A two-stroke engine includes: a scavenging port communicating with a crank chamber and a side portion of a cylinder, and switchably brought into communication with or shut off from the cylinder by a piston; and multiple fuel injection valves for injecting fuel into the scavenging port. Since the fuel injection valves inject fuel into the scavenging port, there is no need to apply a high pressure injection system. By causing the start of fuel injection to be delayed from a timing at which the scavenging port is opened, fresh air is sent into the cylinder at an early stage of scavenging, and air-fuel mixture is sent into the cylinder at a late stage of scavenging. Thereby, even in a long-stroke engine, stratified scavenging is performed to suppress blow-by of air-fuel mixture.