Patent ID: 9638132
Date: 2017-05-02
CPC Classifications: F01M,F02F

Claim:
1. An internal combustion engine comprising: a cylinder head having a plurality of oil return passages provided along a column direction of a plurality of cylinder bores; and a cylinder block which is arranged below the cylinder head, and which has (i) the plurality of the cylinder bores, (ii) an oil return space in communication with the oil return passages in the cylinder head, and (iii) an oil discharge passage extending in an axial direction of the cylinder bores, and in communication with the oil return space so as to discharge oil in the oil return space to an oil pan, wherein the oil return space includes a first inclined portion provided on an upstream side in an oil flow direction and to which oil is dropped from a first oil return passage of the plurality of the oil return passages, and a second inclined portion provided on a downstream side and to which oil is dropped from a second oil return passage of the plurality of the oil return passages, the oil return space, including the first inclined portion and the second inclined portion, is located at a lateral side of the cylinder bores, the first inclined portion on the upstream side is curved so as to be convex downward, the second inclined portion on the downstream side is sloped so as to be inclined downward with respect to a horizontal direction, and a curved portion of the first inclined portion on the upstream side is connected to the second inclined portion on the downstream side before a tangent line of the first inclined portion turns to the horizontal direction.