Abstract: To improve the oil separation performance in an oil separation device for an internal combustion engine. The oil separation device (10) comprises a gas liquid separation passage (56) internally defined by a lower wall, an upper wall and a pair of side walls, and extending in a horizontal direction, a gas inlet (54) and a gas outlet (63) provided on either end of the gas liquid separation passage, a plurality of lower partition walls (56H) projecting upward from the lower wall, and a plurality of upper partition walls (56J) projecting downward from the upper wall. The lower partition walls and the upper partition wall are tilted with respective the length wise direction in plan view so as to define a spiral passage. The lower wall is inclined with respect to a horizontal plane such that an upstream part of the lower wall is lower than a downstream part of the lower wall with respect to a direction of the swirl flow.

Abstract: To improve the oil separation performance in an oil separation device for an internal combustion engine. The oil separation device (10) comprises a gas liquid separation passage (56) internally defined by a lower wall, an upper wall and a pair of side walls, and extending in a horizontal direction, a gas inlet (54) and a gas outlet (63) provided on either end of the gas liquid separation passage, a plurality of lower partition walls (56H) projecting upward from the lower wall, and a plurality of upper partition walls (56J) projecting downward from the upper wall. The lower partition walls and the upper partition wall are tilted with respective the length wise direction in plan view so as to define a spiral passage. The lower wall is inclined with respect to a horizontal plane such that an upstream part of the lower wall is lower than a downstream part of the lower wall with respect to a direction of the swirl flow.

Abstract: To improve the oil separation performance in an oil separation device for an internal combustion engine. The oil separation device (10) comprises a gas liquid separation passage (56) internally defined by a lower wall, an upper wall and a pair of side walls, and extending in a horizontal direction, a gas inlet (54) and a gas outlet (63) provided on either end of the gas liquid separation passage, a plurality of lower partition walls (56H) projecting upward from the lower wall, and a plurality of upper partition walls (56J) projecting downward from the upper wall. The lower partition walls and the upper partition wall are tilted with respective the length wise direction in plan view so as to define a spiral passage. The lower wall is inclined with respect to a horizontal plane such that an upstream part of the lower wall is lower than a downstream part of the lower wall with respect to a direction of the swirl flow.

Abstract: An oil level gauge mounting structure includes an oil level gauge, a dipstick insertion hole, a peripheral wall, and an opening portion. The oil level gauge includes a grip portion and a dipstick. The grip portion has a finger insertion hole which defines a finger insertion direction for the finger insertion hole and into which a finger of an operating person is to be inserted from the finger insertion direction for the finger insertion hole. The peripheral wall surrounds the grip portion from directions except the finger insertion direction for the finger insertion hole so as to define an insertion recess portion to receive the grip portion in a state in which the dipstick is inserted in the dipstick insertion hole. The opening portion is open in the finger insertion direction for the finger insertion hole in the state in which the dipstick is inserted in the dipstick insertion hole.

Abstract: To improve the oil separation performance in an oil separation device for an internal combustion engine. The oil separation device (10) comprises a gas liquid separation passage (56) internally defined by a lower wall, an upper wall and a pair of side walls, and extending in a horizontal direction, a gas inlet (54) and a gas outlet (63) provided on either end of the gas liquid separation passage, a plurality of lower partition walls (56H) projecting upward from the lower wall, and a plurality of upper partition walls (56J) projecting downward from the upper wall. The lower partition walls and the upper partition wall are tilted with respective the length wise direction in plan view so as to define a spiral passage. The lower wall is inclined with respect to a horizontal plane such that an upstream part of the lower wall is lower than a downstream part of the lower wall with respect to a direction of the swirl flow.

Abstract: An oil level gauge mounting structure includes an oil level gauge, a dipstick insertion hole, a peripheral wall, and an opening portion. The oil level gauge includes a grip portion and a dipstick. The grip portion has a finger insertion hole which defines a finger insertion direction for the finger insertion hole and into which a finger of an operating person is to be inserted from the finger insertion direction for the finger insertion hole. The peripheral wall surrounds the grip portion from directions except the finger insertion direction for the finger insertion hole so as to define an insertion recess portion to receive the grip portion in a state in which the dipstick is inserted in the dipstick insertion hole. The opening portion is open in the finger insertion direction for the finger insertion hole in the state in which the dipstick is inserted in the dipstick insertion hole.