Patent ID: 6223705
Filing Date: 2001-05-01
Classification: F02B

Abstract:
A two-stroke internal combustion engine having a Schnurle scavenging system, comprisinga pair of first scavenging ports which are disposed close to an exhaust port and symmetrically with respect to a longitudinal sectional plane (F) that bisects the exhaust port of a cylinder, and a pair of second scavenging ports which are disposed remote from the exhaust port and symmetrically with respect to the longitudinal sectional plane (F), the first and second scavenging ports being the sole scavenging ports of the scavenging system;wherein an inner horizontal scavenging angle formed close to the exhaust port and an outer horizontal scavenging angle formed remote from the exhaust port by a pair of scavenging flows blown out of the pair of the first scavenging ports are both set to an angle in the range of from 116 to 124 degrees, and an inner horizontal scavenging angle formed close to the exhaust port and an outer horizontal scavenging angle formed remote from the exhaust port by a pair of scavenging flows blown out of the pair of second scavenging ports are set to angles in the ranges of from 126 to 134 degrees and from 146 to 154 degrees, respectively; andwherein said pair of scavenging flows blown out of the pair of the first scavenging ports are caused to impinge against each other, and said pair of scavenging flows blown out of the pair of the second scavenging ports are caused to impinge against each other.