Two-stroke cycle gasoline engine
AssigneeToyota Jidosha Kogyo Kabushiki Kaisha
InventorToshio Tanahashi
Life of this patent
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Abstract
A two-stroke cycle gasoline engine having a first scavenging port which is supplied with fuel-air mixture through a mixture passage, and a second scavenging port which is supplied with air, wherein supply of fuel-air mixture through the mixture passage is substantially throttled while supply of air through the second scavenging port is interrupted, so as to perform stratified scavenging, when the engine is operating at low load, while in medium to high load operation the throttling of the mixture passage is released while air is injected through said second scavenging port, so as to generate swirling of mixture charged in the cylinder chamber.
Claims12
A two-stroke cycle gasoline engine comprising a cylinder bore, a piston slidably received in said cylinder bore so as to define a cylinder chamber, an exhaust port which opens from said cylinder chamber towards the atmosphere, a first scavenging port which has a relatively large opening area and injects fuel-air mixture into said cylinder chamber when uncovered by said piston, a second scavenging port which injects air into said cylinder chamber, a carburetor having a throttle valve for controlling engine load, a first passage which conducts fuel-air mixture from said carburetor towards said first scavenging port, a second passage which conducts air towards said second scavening port, a controller, a first control valve at a middle portion of said first passage connected to be controlled by said controller and which controls said first passage so as to throttle it when the engine load is below a predetermined relatively low value, and to open it when the engine load is above said predetermined relatively low value, and a second control valve at a middle portion of said second passage connected to be controlled by said controller and which controls said second passage so as substantially to interrupt it when engine load is below said predetermined relatively low value and to open it when the engine load is above said predetermined relatively low value.
The engine of any one of the preceding claims, wherein said controller is adapted to control said first and second control valves according to engine temperature so as to open them when engine temperature is below a predetermined value.
Dependencies are inferred from the claim text.