Supercharged engine structure for motorcycles

摘要

The present invention relates to a supercharged engine structure (15) for a motorcycle (2) comprising a connecting rod (25) substantially dividing an interior of a crankcase into first and second air chambers (B), wherein the first air chamber (A) is connected to an air introduction unit via an air cleaner (35) while the second air chamber (B) connects to a combustion chamber via an intercooler which cools the air output from said second air chamber (B) and an air intake passage connected to an outlet of said intercooler (36), wherein said second air chamber (B) serves as a compression chamber and said connecting rod (25,33) forming a compressor element by changing an effective internal volume of the crankcase. In order to reduce or inhibit the inflow of lubricating oil from the crankcase compression chamber to the combustion chamber, an outlet of said intercooler (36) being located at an upper portion of said intercooler (36).