Abstract: Disclosed is a blowby gas treatment device for an internal combustion engine with a supercharger, the blowby gas treatment device comprising: a fresh air introduction passage wherein one end of the fresh air introduction passage is connected to an upstream side of the supercharger and the other end is communicated with a crankcase of the internal combustion engine; a first blowby gas passage wherein one end of the first blowby gas passage is connected to a venturi part provided in an upstream side of the supercharger in the intake passage and the other end is communicated with the crankcase; a first check valve being interposed in the fresh air introduction passage and preventing a flow from the crankcase side to the intake passage side; and a second check valve being interposed in the blowby gas passage and preventing a flow from the intake passage side to the crankcase side.

Abstract: A separator unit of an oil mist separator comprises a front unit including a perforated plate and a plurality of holding studs extending rearward from the perforated plate, a rear unit placed behind the perforated plate and including a base plate that is to be intimately put on a rear surface of the perforated plate and has an opening sized to permit insertion of the holding studs of the front unit, a plurality of connecting studs extending rearward from the base plate and an impinge plate held by leading ends of the connecting studs, and a fiber material piece put on the impinge plate, wherein when the front unit is coupled with the rear unit having the holding studs inserted through the opening of the base plate, the fiber material piece is sandwiched between the leading ends of the holding studs and the impinge plate.

Abstract: Disclosed is a blowby gas treatment device for an internal combustion engine with a supercharger, the blowby gas treatment device comprising: a fresh air introduction passage wherein one end of the fresh air introduction passage is connected to an upstream side of the supercharger and the other end is communicated with a crankcase of the internal combustion engine; a first blowby gas passage wherein one end of the first blowby gas passage is connected to a venturi part provided in an upstream side of the supercharger in the intake passage and the other end is communicated with the crankcase; a first check valve being interposed in the fresh air introduction passage and preventing a flow from the crankcase side to the intake passage side; and a second check valve being interposed in the blowby gas passage and preventing a flow from the intake passage side to the crankcase side.

Abstract: An oil drain structure for an oil mist separator including a drain pipe extending from the oil mist separator into the internal combustion engine, the drain pipe having an oil discharge hole extending through a lower end portion of the drain pipe along an axial direction of the drain pipe, and a check valve including a valve body disposed below the lower end portion of the drain pipe, the valve body acting to open and close the oil discharge hole from a side of a lower surface of the lower end portion of the drain pipe, a valve head portion fitted into the drain pipe with a fine clearance as an orifice and being moveable in the axial direction of the drain pipe, and a stem portion extending through the oil discharge hole to connect the valve body and the valve head portion with each other.

Abstract: A separator unit of an oil mist separator comprises a front unit including a perforated plate and a plurality of holding studs extending rearward from the perforated plate, a rear unit placed behind the perforated plate and including a base plate that is to be intimately put on a rear surface of the perforated plate and has an opening sized to permit insertion of the holding studs of the front unit, a plurality of connecting studs extending rearward from the base plate and an impinge plate held by leading ends of the connecting studs, and a fiber material piece put on the impinge plate, wherein when the front unit is coupled with the rear unit having the holding studs inserted through the opening of the base plate, the fiber material piece is sandwiched between the leading ends of the holding studs and the impinge plate.

Abstract: An oil drain structure for an oil mist separator including a drain pipe extending from the oil mist separator into the internal combustion engine, the drain pipe having an oil discharge hole extending through a lower end portion of the drain pipe along an axial direction of the drain pipe, and a check valve including a valve body disposed below the lower end portion of the drain pipe, the valve body acting to open and close the oil discharge hole from a side of a lower surface of the lower end portion of the drain pipe, a valve head portion fitted into the drain pipe with a fine clearance as an orifice and being moveable in the axial direction of the drain pipe, and a stem portion extending through the oil discharge hole to connect the valve body and the valve head portion with each other.

Abstract: In ventilation system and method for a supercharge engine, in a middle load driving region of the engine in which the boost pressure of position of an intake air passage located at the downstream side with respect to a throttle valve is positive and is lower than a set pressure (P1), with importance placed on the ventilation of a crank chamber, a relatively large quantity of fresh air is introduced into the crank chamber and, on the other hand, in a high load driving region in which the boost pressure is equal to or higher than the set pressure (P1), with importance placed on the engine output, the large quantity of fresh air is supplied to the engine so that, while the deterioration of engine oil within the crank chamber suppressed, the output reduction of the engine in the high load driving region can be suppressed.

Abstract: An oil separator provided in combination with a cylinder head cover of an internal combustion engine. The oil separator includes a separator cover fixed to an inner surface of the cylinder head cover defining a space extending in a first direction perpendicular to axis of a camshaft in plan, between the separator cover and the cylinder head cover. The separator cover has an opening through which the space is opened to a valve operating chamber. A partition wall is provided to define in the space an inlet-side separator chamber and an outlet-side separator. The partition wall extends in a second direction parallel with the axis of the camshaft and being formed with a plurality of fine passages. Additionally, a plurality of projection walls project from a part of the inner surface of the cylinder head cover which faces the valve operating chamber through the opening.

Abstract: An oil separator provided in combination with a cylinder head cover of an internal combustion engine. The oil separator includes a separator cover fixed to an inner surface of the cylinder head cover defining a space extending in a first direction perpendicular to axis of a camshaft in plan, between the separator cover and the cylinder head cover. The separator cover has an opening through which the space is opened to a valve operating chamber. A partition wall is provided to define in the space an inlet-side separator chamber and an outlet-side separator. The partition wall extends in a second direction parallel with the axis of the camshaft and being formed with a plurality of fine passages. Additionally, a plurality of projection walls project from a part of the inner surface of the cylinder head cover which faces the valve operating chamber through the opening.