| 主权项 |
1. A rotary carburetor which is used in a stratified scavenging two-stroke internal combustion engine, comprising:
a block-like body having a cylindrical bore with a center of an axis; a valve element having a cylindrical form and rotatably contained in the bore; and a nozzle unit disposed in the valve element along the axis, wherein the valve element includes valve passages for air and a valve passage for mixture extending through the valve element in a direction across the axis, wherein the nozzle unit includes a port which is opened to the valve passage for mixture and ejects fuel, wherein the body includes upstream body passage communicating with the valve passages for air and the valve passage for mixture upstream of the valve element, and downstream body passages for air and downstream body passage for mixture respectively communicating with the valve passages for air and the valve passage for mixture downstream of the valve element, wherein the valve element is rotatable around the axis between an opened position and an closed position, wherein in the opened position, the valve passages for air and the valve passage for mixture respectively communicate with the downstream body passages for air and the downstream body passage for mixture, and the valve passages for air and the valve passage for mixture communicate with the upstream body passage, wherein in the closed position, the valve passages for air and the valve passage for mixture are respectively blocked off from the downstream body passages for air and the downstream body passage for mixture, and the valve passages for air, and the valve passage for mixture are blocked off from the upstream body passage, wherein the rotary carburetor is a one-bore type rotary carburetor in which the valve passages for air and the valve passage for mixture are partitioned with plate-like valve partitions, and the downstream body passages for air and the downstream body passage for mixture are partitioned with plate-like body partitions, wherein the two downstream body passages for air and the two valve passages for air are provided, and are respectively disposed on the opposite sides of the downstream body passage for mixture and the valve passage for mixture in the axis direction, wherein cross-sectional profiles of the downstream body passage for mixture and the valve passage for mixture are defined so that they are communicated with each other earlier than the downstream body passages for air and the valve passages for air, when the valve element is rotated from the closed position to the opened position, and wherein the cross-sectional profiles of the two downstream body passages for air and the two valve passages for air correspond to each other. |
