Patent ID: 8522742

Claim:
A multi-cylinder internal combustion engine provided, on the downside of a cylinder block, with a communicating passage configured by an upper crankcase integrated with the cylinder block or provided separately from the cylinder block and a lower crankcase connected to a lower part of the upper crankcase for communicating with an internal space of a plurality of crank chambers corresponding to a plurality of cylinders, the multi-cylinder internal combustion engine comprising: a communicating hole that is provided at least on either side of the upper crankcase or the lower crankcase for communicating with the communicating passage; a cover for forming the communicating passage, said cover being arranged with the cover covering the communicating hole; and the cover is attached to both the upper and lower crankcases across a joined plane of the upper crankcase and the lower crankcase, wherein a groove for arranging a sealing member is formed on a surface joined to the crankcase of the cover; and each joining surface of the other upper and lower crankcases is flatly formed, the communicating passage is formed in the shape of a large bowl with the communicating passage covering the communicating hole in a front view; and the space for the communicating passage is configured by an inside face of the cover and the front of the crankcase, wherein the communicating passage includes multiple communicating passages formed in order along the cylinder block.