Air Leading-Type Stratified Scavenging Two-Stroke Internal-Combustion Engine

摘要

The efficiency of charging air to a scavenging channel is enhanced by generating a gas flow in a piston groove simultaneously with the piston groove coming into communication with an air port. A piston groove 8 formed in a peripheral surface of a piston includes a pressure transmission through hole 10, and the pressure transmission through hole 10 consistently communicates with a crankcase. In the course of the piston moving up, upon a pressure in the crankcase becoming negative, the negative pressure in the crankcase affects the piston groove 8through the pressure transmission through hole 10. Consequently, a pressure in the piston groove 8 is released to the crankcase through the pressure transmission through hole 10. Upon the piston moving up and the piston groove 8 being thereby brought into communication with the air port 4a, air enters the piston groove 8 through the air port 4a ((III) of FIG. 1).

主权项

1. An air leading-type stratified scavenging two-stroke internal-combustion engine comprising:
an air port that opens in a cylinder wall and is opened/closed by a piston; a scavenging channel including a scavenging port that opens in the cylinder wall and is opened/closed by the piston, the scavenging channel communicating with a crankcase; and a piston groove formed in a peripheral surface of the piston, the piston groove enabling the air port and the scavenging port to communicate with each other, wherein the piston groove includes a pressure transmission through hole that communicates with the crankcase.