To provide an oil separation device constituted by providing a gas-liquid separation chamber 2 opening a blow-by gas inlet 4 in a lower part and a blow-by gas outlet 5 in an upper part on a side face of a cylinder block 1 or a cylinder head in a recessed manner, attaching a lid body 3 blocking the gas-liquid separation chamber detachably, and forming a labyrinth passage 7 for letting blow-by gas flow from the blow-by gas inlet toward the blow-by gas outlet in a zigzag manner in the left and right directions by a labyrinth passage forming member 6 attached to an inner face of a lid plate in the gas-liquid separation chamber to improve its oil separation performance.
Plate members 8, 9 are attached to the lid body 3 in parts in close proximity to vertical internal wall faces 2a, 2b extending in the vertical direction on an inner face of the gas-liquid separation chamber 2 among the labyrinth passage forming members so as to extend in the vertical direction in parallel with the vertical internal wall face or substantially in parallel. Extension parts 8a, 8b, 9a are provided at at least either of upper end and lower end of the plate member.
KO HIDEYUKI
KAMIKAWA YASUAKI
Tadashi Higashino
Hiroyuki Nishi
Ryuichi Watanabe