Kioritz Corporation

Kentaro Matsuo

Shigeru Sato

Mitsujiro Mochizuka

Takahiro Yamazaki

Hidekazu Tsunoda

Shiro Yamaguchi

Keita Kamo

Masakuni Hiroshima

A cylinder bore () of a two-stroke internal combustion engine () has first scavenging ports () and second scavenging ports () inside. The first scavenging ports () are nearer to an exhaust port () of the engine () than the second scavenging ports (). In each scavenging stroke, the second scavenging ports () are opened earlier than the first scavenging ports () and introduce fuel-free air (A) from the second scavenging ports () into a combustion chamber (). The first scavenging ports () are opened later and introduce an air-fuel mixture (M) pre-compressed in a crank chamber () into the same combustion chamber (). Thus, harmful substances contained in exhaust gas discharged from the engine () are reduced.

Two-stroke internal combustion engine

A two-stroke internal combustion engine () is provided with one pair or plural pairs of C-shaped scavenging passageways () of a reverse flow system where scavenging inlet ports () as well as scavenging outlet ports () are both opened to a cylinder bore (), wherein a scavenging introducing passageway () for introducing an air-fuel mixture (K) from a crank chamber () into the scavenging inlet ports () is provided between the cylinder bore and the piston adapted to reciprocatively move up and down in the cylinder bore (), and an effective opening area of the scavenging inlet ports () is gradually decreased due to the piston () in the course of descending stroke of the piston ().

A two-stroke internal combustion engine having a Schn&uuml;rle scavenging system includes a pair of first scavenging ports and a pair of second scavenging ports. An inner horizontal scavenging angle formed close to an 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. 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 second scavenging ports are set to angles in the ranges of from 126 to 134 degrees and from 146 to 154 degrees, respectively.

Growing community of inventors

Saitama, Japan

Kentaro Matsuo