JP2015094239A - Breather system of internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a breather system of an internal combustion engine which preferably performs gas-liquid separation of a blow-by gas.SOLUTION: A breather system 1 of an internal combustion engine includes: a breather chamber R2 provided at an upper part of a head cover 14; and guide passages R1a, R1b which are provided at the upper part of the head cover 14 and connect breather passages R0a, R0b, in which a blow-by gas circulates, with the breather chamber R2. The breather chamber R2 includes: a first gas-liquid separation chamber R2a connected with the guide passages R1a, R1b; a second gas-liquid separation chamber R2b connected with an intake passage; and a communication passage R2c which connects the first gas-liquid separation chamber R2a with the second gas-liquid separation chamber R2b. The breather system 1 of the internal combustion engine further includes: a PCV valve 41 provided at the communication passage R2c; and a one-way valve 42 which is provided at the other end part of the second gas-liquid separation chamber R2b when viewed in a cylinder row direction. The second gas-liquid separation chamber R2b includes a revolving part 61 for revolving the blow-by gas.

Description

  The present invention relates to a breather system for an internal combustion engine.

  2. Description of the Related Art Conventionally, in an internal combustion engine such as a vehicle, there is a breather system in which oil is gas-liquid separated from blow-by gas generated inside the internal combustion engine, and the blow-by gas separated from the gas-liquid is returned to the intake side of the internal combustion engine to reburn unburned gas. It is known (see Patent Document 1).

Japanese Patent No. 4353473

The breather system described in Patent Document 1 includes baffle plates that are alternately erected from the bottom surface and the ceiling surface of the gas-liquid separation chamber, and ensures the flow length of the blow-by gas by meandering the blow-by gas up and down. Gas-liquid separation performance is improved.
However, in order to improve the performance of the internal combustion engine, further improvement of the gas-liquid separation performance of blow-by gas is desired.

  The present invention has been made in view of the above points, and provides a breather system for an internal combustion engine capable of suitably performing gas-liquid separation of blow-by gas.

  In order to solve the above-described problems, a breather system for an internal combustion engine according to the present invention uses blow-by gas generated inside an internal combustion engine having a supercharger through the intake passage using the intake negative pressure of the intake passage. A breather system for an internal combustion engine having a PCV circuit that recirculates and is used again for combustion, the breather chamber being provided on the head cover of the internal combustion engine and connected to a breather passage through which blow-by gas generated in the internal combustion engine flows. The breather chamber extends in the cylinder row direction, and extends in the cylinder row direction along with the first gas-liquid separation chamber connected to the breather passage and the first gas-liquid separation chamber. A second gas-liquid separation chamber connected to the inside of the internal combustion engine via the intake passage, and the first gas-liquid separation chamber on one end side in the cylinder row direction A communication passage that connects the second gas-liquid compartment, and a PCV valve that is provided in the communication passage and adjusts the flow rate of the blow-by gas, and the other end in the cylinder row direction of the second gas-liquid separation chamber And a one-way valve that allows only the discharge of the blow-by gas from the second gas-liquid separation chamber, and the second gas-liquid separation chamber is a blow-by that circulates through the second gas-liquid separation chamber. A swirl unit that swirls gas is provided.

According to this configuration, since the breather chamber is separated into two gas-liquid separation chambers by the PCV valve, when the blowby gas passes through the PCV valve, oil mist having a relatively large particle size is captured by the PCV valve and blown by. The oil mist having a relatively small particle diameter removed from the gas and passing through a narrow passage in the PCV valve adheres to each other and is introduced into the second gas-liquid separation chamber as an oil mist having a large particle diameter. . The oil mist having such a large particle size is easily subjected to gas-liquid separation in the second gas-liquid separation chamber.
Further, the blow-by gas circulates in the second gas-liquid separation chamber as a spiral swirl flow while swirling in the vertical direction by the swirl part in the second gas-liquid separation chamber, so the oil mist contained in the blow-by gas is By the centrifugal force of the swirling flow, they stick to each other to become an oil mist having a larger particle size and are separated into gas and liquid, thereby improving the gas-liquid separation performance.
In addition, since a one-way valve is provided at the blow-by gas outlet of the second gas-liquid separation chamber, when the supercharger is activated and the intake passage becomes a positive pressure state, a new connection from the intake passage to the breather chamber is performed. It is possible to prevent the reverse flow of the gas, and it is possible to favorably maintain the pressure adjustment performance and scavenging performance in the internal combustion engine body.

  A breather system for an internal combustion engine extends in the cylinder row direction along with the breather chamber above the head cover of the internal combustion engine, introduces fresh air using negative pressure inside the internal combustion engine, and A fresh air chamber for scavenging the interior, the fresh air chamber being connected to the inside of the internal combustion engine at one end in the cylinder row direction and the excess of the intake passage at the other end in the cylinder row direction. A structure may be provided that is connected to the upstream side of the feeder and includes a swirling unit that swirls the fresh air flowing through the fresh air chamber and the blow-by gas.

  According to this configuration, when blow-by gas inside the internal combustion engine is supplied to the intake passage by the intake negative pressure, fresh air is introduced into the internal combustion engine from the fresh air chamber by the negative pressure inside the internal combustion engine, In addition to being able to scavenge well, when the turbocharger is operating at a high load and high speed of the internal combustion engine, if the intake passage is brought into a positive pressure state by the compressor of the turbocharger, one direction of the breather chamber Since the valve is closed and blow-by gas does not flow through the breather chamber, blow-by gas may flow into the fresh air chamber, but the new air chamber with the swivel part functions as a gas-liquid separation chamber Since gas-liquid separation is possible, blow-by gas from which oil has been removed will flow into the intake passage, preventing internal oil from adhering to the intake passage. Prevents the increased pressure in the body portion, it is possible to suitably maintain the scavenging performance of an internal combustion engine body.

  The swivel portion includes a lower rib extending from a bottom surface of the chamber provided with the swivel portion toward a ceiling inner surface of the chamber, and an upper rib extending from the ceiling inner surface of the chamber toward the bottom surface of the chamber. The lower rib and the upper rib may be arranged to face each other so as to have an X shape in plan view.

  According to such a configuration, each rib of the swirl portion swirls the blow-by gas so as to form a spiral in the vertical direction. Therefore, even if the length in the cylinder row direction of the internal combustion engine is short and the passage diameter of each chamber is small, the centrifugal force By this, sufficient gas-liquid separation performance can be realized. Furthermore, since the head cover, the breather chamber, and the fresh air chamber can be downsized, the internal combustion engine can be downsized.

  The breather system for an internal combustion engine according to the present invention further includes a guide path that is provided in the head cover of the internal combustion engine and that connects a breather passage through which blow-by gas generated inside the internal combustion engine flows and the breather chamber. The one gas-liquid separation chamber is connected to the guide path at the other end side in the cylinder row direction, and a first oil return hole formed at the other end portion in the cylinder row direction on the bottom surface of the first gas-liquid separation chamber; A second oil return hole formed at one end of the bottom of the second gas-liquid separation chamber in the cylinder row direction or at the second gas-liquid separation chamber side end of the bottom of the communication path. May be.

According to such a configuration, when the intake passage at the time of operation of the supercharger is in a positive pressure state, even if the one-way valve provided in the breather chamber is closed and the blow-by gas flow is almost stopped, Oil that has been gas-liquid separated in the guide passage and the first gas-liquid separation chamber can be quickly returned to the internal combustion engine body from the first oil return hole, and oil accumulated in the second gas-liquid separation chamber can be removed. The second oil return hole can be quickly returned into the internal combustion engine body.
In addition, when the intake passage is in a negative pressure state when the supercharger during low or medium rotation of the internal combustion engine is not operating, the flow rate of the blow-by gas flowing into the first gas-liquid separation chamber is compared. Even if the first oil return hole is formed in the vicinity of the connection position with the guide path, the amount of gas-liquid separated oil around the first oil return hole is wound up by blow-by gas and mixed. In addition, since the first oil return hole is provided at a position away from the PCV valve, the flow of blow-by gas through which the oil in the first gas-liquid separation chamber is stored near the PCV valve and circulates in the PCV valve Can be prevented.

  The first gas-liquid separation chamber also functions as the oil return hole portion and blow-by gas inlet hole portion formed on the bottom surface on the other end side in the cylinder row direction, and the oil return hole portion when the internal combustion engine is mounted on the vehicle. In order to introduce blow-by gas into the first gas-liquid separation chamber at a position above the blow-by gas inlet hole and at a position different from the upstream side in the direction in which the oil separated from the blow-by gas flows. The auxiliary opening may be provided.

  According to this configuration, even when the oil return hole is closed with return oil, the blow-by gas can be satisfactorily introduced into the breather chamber from the auxiliary opening near the oil hole.

  The bottom surface of the first gas-liquid separation chamber is inclined downward from one end of the cylinder row to the other end of the cylinder row in a state where the internal combustion engine is mounted on the vehicle, The bottom surface is preferably inclined downward from the other end side of the cylinder row toward the one end side of the cylinder row when the internal combustion engine is mounted on the vehicle.

  According to this configuration, the first gas-liquid separation chamber and the second gas-liquid separation chamber and the second gas-liquid separation chamber are inclined so that the bottom surfaces of the first gas-liquid separation chamber and the second gas-liquid separation chamber are lowered toward the respective oil return holes. Oil separated into gas and liquid in the interior can be quickly returned into the internal combustion engine body through the oil return holes.

  The PCV valve is provided along the extending direction of the second gas-liquid separation chamber at the end of the communication path on the second gas-liquid separation chamber side, The rib facing the blow-by gas outlet of the PCV valve may be formed with a predetermined gap with respect to the blow-by gas outlet.

According to this configuration, since the PCV valve serving as the communication path between the first gas-liquid separation chamber and the second gas-liquid separation chamber is provided along the extending direction of the second gas-liquid separation chamber, the cylinder row of the head cover The width in the direction perpendicular to the angle can be designed to be compact, and both the miniaturization of the breather chamber and the securing of suitable gas-liquid separation performance can be achieved.
Also, the blow-by gas discharged from the PCV valve to the second gas-liquid separation chamber passes through a narrow flow path inside the PCV valve and flows out from the blow-by gas outlet at an increased flow velocity, and faces the blow-by gas outlet of the PCV valve. Since the fine oil mist adheres to the ribs and falls with an increased particle size, the gas-liquid separation performance can be further improved.

  The breather system for an internal combustion engine according to the present invention includes a plurality of sets of the breather passages and the guide passages, and the plurality of breather passages are provided at positions where oil pans provided at the bottom of the internal combustion engine have different depths. It may be a configuration.

  According to this configuration, since the plurality of breather passages are provided at positions where the depths of the oil pans are different, some of the breather passages are oiled when the internal combustion engine is inclined, such as when the vehicle is turning or running on a slope. Even in the case of being submerged, blow-by gas can be introduced into the breather chamber from the remaining breather passage, and the internal pressure of the internal combustion engine can be suitably adjusted. It is possible to suppress an increase in friction due to an increase in blow-by gas and an increase in friction.

  The breather passage also serves as an oil level gauge insertion hole portion, and an upper end portion of the breather passage branches from the oil level gauge insertion hole portion and is connected to the guide path. The head cover includes the oil level gauge insertion hole portion. Even if it is configured to include an oil level gauge guide hole that faces the tip of the level gauge insertion hole, and a flange that covers a space between the oil level gauge guide hole and the oil level gauge insertion hole Good.

According to this configuration, the breather passage and the oil level gauge insertion hole are used as one hole, so that the processing is easy and the internal combustion engine can be downsized.
Further, since the flange portion is provided, it is possible to prevent the oil mist of blow-by gas flowing through the breather passage from adhering to the upper end portion of the oil level gauge insertion hole R4. That is, it is possible to prevent oil unrelated to measurement from adhering to the gauge part of the oil level gauge at the upper end of the oil level gauge insertion hole when attaching / detaching the oil level gauge, and to realize a suitable measurement of the oil level. .

  The oil level gauge may include a bulging portion that closes the oil level gauge insertion hole above a position branched from the breather passage.

  According to such a configuration, even if oil adheres to the upper end portion of the oil level gauge insertion hole portion, such oil adheres to the bulge portion, so that oil unrelated to the measurement is applied to the gauge portion of the oil level gauge. Adhesion can be prevented and a suitable measurement of the oil level can be realized.

  According to the present invention, it is possible to provide a more compact breather system while suppressing the backflow of blow-by gas to the gas-liquid separation chamber and the increase in pressure inside the internal combustion engine when the supercharger is operating, and maintaining the scavenging performance inside the internal combustion engine. can do.

1 is a schematic diagram showing an internal combustion engine according to an embodiment of the present invention. It is a perspective view which shows the head cover provided with the breather chamber and the chamber for fresh air. It is a top view which shows the head cover provided with the breather chamber and the chamber for fresh air. It is sectional drawing which shows the inside of the chamber of the head cover provided with the breather chamber and the chamber for fresh air, and is a figure which shows the flow of blow-by gas in a negative pressure state. (A) is the X1 arrow cross section of FIG. 3, (b) is X2 arrow cross section of FIG. (A) is a cross section taken along the arrow X3 in FIG. 3, and (b) is a cross section taken along the arrow X4 in FIG. It is sectional drawing which shows the chamber inside of the head cover provided with the breather chamber and the chamber for fresh air, and is a figure which shows the flow of blow-by gas in a positive pressure state. FIG. 4 is a cross-sectional view taken along arrow X5 in FIG. 3 and shows an oil level gauge insertion hole and an oil level gauge. It is the perspective view which looked at the head cover from the bottom. (A) is X6 arrow sectional drawing of FIG. 9, (b) is X7 arrow sectional drawing of FIG. 9, (c) is X8 arrow sectional drawing of FIG. It is a top view which shows the breather system which concerns on other embodiment of this invention. It is X9 arrow sectional drawing of FIG.

  Embodiments of the present invention will be described in detail with reference to the drawings. In the description, the same elements are denoted by the same reference numerals, and redundant description is omitted. In the present embodiment, a case where the internal combustion engine of the present invention is applied to an in-line four-cylinder engine (L4 engine) of an automobile will be described as an example. Moreover, when explaining a direction, it demonstrates based on the front-back, up-down, right-and-left of the vehicle shown in FIG.

  In the present embodiment, the vertical direction coincides with the vertical direction when the internal combustion engine is mounted on an automobile, and the cylinder row direction coincides with the horizontal direction when the internal combustion engine is mounted on the automobile. The cylinder row direction one end side is the left side when the internal combustion engine is mounted on an automobile, the cylinder row direction one end side is the right side when the internal combustion engine is mounted on the vehicle, and the chain case of the internal combustion engine is It is the side where it is provided. The upper side is the side where the head cover of the internal combustion engine is provided, and the lower side is the side where the oil pan of the internal combustion engine is provided. The front side is the side where the exhaust side camshaft is provided, and the rear side is the side where the intake side camshaft is provided. Further, the cylinder row direction coincides with the longitudinal direction of the cylinder head 13.

  As shown in FIG. 1, the internal combustion engine E according to the embodiment of the present invention includes a cylinder block 11, a lower block 12, a cylinder head 13, a head cover 14, and an oil pan 15 as an engine body.

<Cylinder block>
Although not shown, the cylinder block 11 is a member mainly constituting a cylinder bore and a crankcase. A piston, a connecting rod, a crankshaft and the like are accommodated in the cylinder block 11.

<Lower block>
The lower block 12 is a member that forms a crankcase together with the cylinder block 11, and is disposed below the cylinder block 11. Although not shown in detail, in the present invention, the journal portion of the crankshaft is formed by a plurality of upper crank journal portions formed at the lower portion of the cylinder block 11 and a plurality of lower crank journal portions formed at the upper surface of the lower block 12. It is held rotatably.

<Cylinder head>
The cylinder head 13 is a member that constitutes a combustion chamber together with a piston crown surface that is slidably disposed inside the cylinder by a concave portion on a bottom surface formed at a position corresponding to the cylinder bore formed in the cylinder block 11. It is arranged above the cylinder block 11. Although not shown in the drawings, the cylinder head 13 has an intake port and an exhaust port communicating with the combustion chamber, and has an intake valve and an exhaust valve for opening and closing the intake port and the exhaust port. A valve operating chamber in which a valve operating mechanism such as a rocker arm is disposed is formed in the upper part of the cylinder head. An intake side camshaft and an exhaust side camshaft to which the drive of the crankshaft is transmitted are disposed in the valve operating chamber.

<Head cover>
The head cover 14 is a lid-like member that closes the upper part of the cylinder head 13 and constitutes a valve operating chamber, and is disposed above the cylinder head 13. In general, the gas-liquid separation chamber is formed in the head cover 14 or in the upper portion of the head cover 14 so as to be integrated with or separate from the head cover 14.

<Oil pan>
The oil pan 15 is a member for receiving oil falling by lubricating each part in the internal combustion engine E and storing oil, and is disposed below the lower block 12. An oil strainer for supplying oil to an oil pump for pumping oil to each part in the internal combustion engine E is disposed inside the oil pan 15.

  The internal combustion engine E is an engine having a supercharger. The intake passage 2x includes an air cleaner 2a, a compressor 2b that is a part of the supercharger, a throttle valve 2c, and an intake manifold (intake manifold) 2d. Is provided.

<Blowby gas>
The blow-by gas is a gas containing unburned gas and oil mist generated in the combustion chamber, and leaks from the combustion chamber to the crankcase as the piston slides. This blow-by gas is returned to the breather system 1 of the internal combustion engine E through the breather passage.

  In FIG. 1, black arrows represent the flow of blow-by gas and fresh air in the negative pressure state of the intake passage 2x, that is, the state where the supercharger is stopped. The white arrow represents the flow of blow-by gas in the positive pressure state of the intake passage 2x, that is, in the state where the supercharger is operating. Moreover, the dotted line arrow represents the flow of oil gas-liquid separated from blow-by gas.

  In such an internal combustion engine E, fresh air taken in via the air cleaner 2a is compressed by the compressor 2b and supplied into the main body of the internal combustion engine E via the throttle valve 2c and the intake manifold 2d.

  When blow-by gas leaked from the combustion chamber into the crankcase in the internal combustion engine E body due to the negative pressure state generated in the intake passage 2x during intake is introduced into the intake passage 2x via the breather passages R0a and Rob. In the blow-by gas, oil contained in the breather chamber 30 at the time of flowing down is separated into gas and liquid and recirculated into the combustion chamber via the intake manifold 2d to be burnt most. Further, since the internal pressure of the internal combustion engine is reduced when the blow-by gas is recirculated, a part of the air supplied to the intake passage is supplied into the internal combustion engine E body through the fresh air chamber 50, To scavenge.

  On the other hand, when the internal combustion engine E is at a high load or at a medium rotation speed, the supercharger is operated, so that the intake passage 2x on the downstream side of the compressor 2b is in a positive pressure state. For this reason, the one-way valve 42 of the breather chamber R2 is closed, and the recirculation of blow-by gas from the breather chamber R2 is stopped. In this state, since the intake passage 2x has a positive pressure, blow-by gas is basically not introduced. However, when the internal combustion engine E is in a high rotation state for a long time, the internal pressure in the internal combustion engine E is And a small amount of blow-by gas flows back through the fresh air chamber R3 and is introduced into the intake air from the upstream side of the compressor 2b. At this time, the blow-by gas is sufficiently gas-liquid separated by the swivel unit 62 in the fresh air chamber R3 and introduced into the intake passage 2x via the fresh air passage 2y.

<Gas-liquid separation passage>
In the present embodiment, as shown in FIGS. 2 and 3, the gas-liquid separation passage 1 of the internal combustion engine E is integrally formed on the upper portion of the head cover 14, and the head cover 14, the breather chamber upper 30, A PCV valve 41, a one-way valve 42, and a fresh air chamber upper 50 are provided. As shown in FIG. 4, the head cover 14, the breather chamber upper 30 and the fresh air chamber 50 constitute guide paths R1a and R1b, a breather chamber R2 and a fresh air chamber R3. In the present embodiment, the breather chamber R2 extends in the left-right direction on the rear end side of the head cover 14 of the internal combustion engine E, and the fresh air chamber R3 extends in the left-right direction on the front end side of the head cover 14 of the internal combustion engine E. It is extended.

<Guideway>
As shown in FIG. 4, the guide path R1a is a blow-by gas flow path that connects the breather path R0a and the first gas-liquid separation chamber R2a so that the blow-by gas can flow. The guide path R1a extends in the front-rear direction when the internal combustion engine E is mounted on the vehicle. The guide path R1a is formed by welding a guide path upper 21a formed integrally with the fresh air chamber 50 and a guide path upper 21b formed integrally with the breather chamber upper 30 to the guide path lower 14a1.

  The guide path R1b is a blow-by gas flow path that connects the breather path R0b and the first gas-liquid separation chamber R2a so that the blow-by gas can flow. In the state where the internal combustion engine E is mounted on the vehicle, the guide path R1b extends in the left-right direction on the upstream side, and extends in the front-rear direction on the downstream side. The guide path R1b is formed by welding a guide path upper 22 formed integrally with the breather chamber upper 30 to the guide path lower 14a2.

  As shown in FIG. 1, the breather passages R0a and R0b are provided at positions where the depth of the oil pan 15 is different. In the present embodiment, the breather passage R0a is provided at a position where the oil pan 15 is relatively deep, and the breather passage R0b is provided at a position where the oil pan 15 is relatively shallow.

<Breeza chamber>
As shown in FIG. 4, the breather chamber R2 gas-liquid separates the blow-by gas introduced from the guide passages R1a and R1b when the intake passage 2x is under a negative pressure, and the blow-by gas separated from the intake passage 2d And return the separated oil into the internal combustion engine E body. The breather chamber R2 is formed by welding the breather chamber upper 30 to the breather chamber lower 14b.

  The breather chamber lower 14b is a member constituting the lower part of the breather chamber R2, that is, the bottom wall of the breather chamber R2, and the lower portions of the front and rear side walls and the left and right side walls, and is formed integrally with the upper surface of the head cover 14. Yes.

  The breather chamber upper 30 is a member that constitutes the upper portion of the breather chamber R2, and includes an upper main body portion 31, partition wall portions 32, valve mounting portions 33 and 34, and ribs 35.

  The upper main body 31 is a member that constitutes the upper wall of the breather chamber R2, the front and rear side walls, and the upper portions of the left and right side walls. The partition wall portion 32 is a wall portion that divides the breather chamber R2 into a first gas-liquid separation chamber R2a, a second gas-liquid separation chamber R2b, and a communication path R2c.

  The valve attachment portion 33 is formed at one end of the upper body portion 31 in the cylinder row direction, and is a hole portion to which the PCV valve 41 is attached. The valve mounting portion 34 is formed at the other end in the cylinder row direction of the upper main body portion 31 and is a hole portion to which the one-way valve 42 is mounted.

  The rib 35 is a rib that stands from the partition wall portion 32 and faces the blow-by gas outlet 41 a of the PCV valve 41 attached to the valve attachment portion 33.

  The breather chamber R2 includes a first gas-liquid separation chamber R2a, a second gas-liquid separation chamber R2b, and a communication path R2c.

<First gas-liquid separation chamber>
The first gas-liquid separation chamber R2a is a blow-by gas passage that has a linear shape in plan view and extends in the cylinder row direction. The bottom surface of the first gas-liquid separation chamber R2a is inclined downward from one end in the cylinder row direction toward the other end in the cylinder row direction. A first oil return hole 14e is formed at the other end in the cylinder row direction on the bottom surface of the first gas-liquid separation chamber R2a. The first oil return hole 14 e communicates with the valve operating chamber in the cylinder head 14.

<Second gas-liquid separation chamber>
The second gas-liquid separation chamber R2b is a blow-by gas passage that exhibits a linear shape in plan view and extends in the cylinder row direction. The second gas-liquid separation chamber R2b is provided along the first gas-liquid separation chamber R2a on the rear side of the first gas-liquid separation chamber R2a when the internal combustion engine is mounted on the vehicle. The bottom surface of the second gas-liquid separation chamber R2b is inclined downward from the other end in the cylinder row direction toward the one end in the cylinder row direction (see FIG. 5A).

<Swivel unit>
As shown in FIG. 5B, the second gas / liquid separation chamber R <b> 2 b includes a turning unit 61. The swivel unit 61 swirls the blow-by gas flowing through the second gas-liquid separation chamber R2b in a spiral manner in the vertical direction, and includes a plurality of upper ribs 61a and a plurality of lower ribs 61b. . As shown by the broken lines in FIG. 3, these ribs 61 a and 61 b are formed so as to face each other substantially at the center position of the ribs 61 a and 61 b so as to exhibit an X shape in plan view.

  The upper rib 61a is erected downward from the inner surface of the breather chamber upper 30 of the breather chamber R2, and the lower rib 61b is erected upward from the breather chamber lower 14b of the breather chamber R2. The upper rib 61a and the lower rib 61b are formed so as to incline at positions substantially intersecting at the center of the rib so as to have an X shape in plan view, and the ribs 61a and 61b allow the blow-by gas to be breathed. A vortex-like flow swirling up and down in the chamber R2 is formed.

<Communication passage>
The communication path R2c is a blow-by gas flow path having a U-shape in plan view that connects one end of the first gas-liquid separation chamber R2a in the cylinder row direction and one end of the second gas-liquid separation chamber R2b in the cylinder row direction. The second gas-liquid separation chamber R2b side end of the bottom surface of the communication path R2c is recessed below the other part of the bottom surface of the communication path R2c and the bottom surface of the second gas-liquid separation chamber R2b. Two oil return holes 14f (see FIG. 5B) are formed.

<PCV valve>
As shown in FIG. 4, the PCV (Positive Crankcase Ventilation) valve 41 is provided along the extending direction of the second gas-liquid separation chamber R2b at the end of the communication path R2c on the second gas-liquid separation chamber R2b side. Yes. The PCV valve 41 is a flow rate adjusting valve for adjusting the flow rate of blow-by gas flowing through the communication passage R2c. The valve is opened when the negative pressure in the intake passage 2x exceeds a predetermined value, and the valve is opened according to the negative pressure strength. When the degree is adjusted and the negative pressure in the intake passage disappears, the valve is closed. Further, the PCV valve 41 vibrates the valve body and the elastic member that urges the valve body in the valve closing direction due to the collision with the blow-by gas, and accordingly, the flow of the blow-by gas is disturbed. The degree to which the oil mist collides with the valve body, the elastic member, and the communication path in the PCV valve 41 is increased, thereby further improving the gas-liquid separation performance of the oil from the blow-by gas. The blow-by gas introduced into the PCV valve 41 from the communication path R2c is discharged from the blow-by gas outlet 41a of the PCV valve 41 to the second gas-liquid separation chamber R2b.

<One-way valve>
The one-way valve 42 is provided at the other end in the cylinder row direction of the second gas-liquid separation chamber R2b, and the downstream side of the one-way valve 42 is connected to the intake manifold 2d so that blow-by gas can flow. The one-way valve 42 opens when the intake passage 2x is in a negative pressure state, allows discharge of blow-by gas from the second gas-liquid separation chamber R2b to the intake manifold 2d, and closes when the intake passage 2x is in a positive pressure state. Valve to prevent backflow of fresh air from the intake passage 2x.

<New air chamber>
The fresh air chamber R3 is introduced into the intake passage 2x when the pressure in the internal combustion engine E decreases as blow-by gas is sucked into the intake passage 2x while the intake passage 2x is in a negative pressure state. A part of the fresh air is introduced into the internal combustion engine E body and scavenged. On the other hand, when the intake passage 2x is in a positive pressure state, the blow-by gas in the internal combustion engine E body is separated into gas and liquid and returned to the intake manifold 2d of the supercharger. One end of the fresh air chamber R3 in the cylinder row direction is connected to the intake passage 2x on the upstream side of the compressor 2b via the fresh air passage 2y so that fresh air and blow-by gas can flow. The other end of the fresh air chamber R3 in the cylinder row direction is connected to the inside of the internal combustion engine E through the intake manifold 2d so that fresh air and blow-by gas can flow.

  The fresh air chamber R3 is formed by welding or bonding the fresh air chamber upper 50 to the fresh air lower chamber 14c.

  The fresh air chamber lower 14c is a member that constitutes the lower part of the fresh air chamber R3, that is, the bottom wall of the fresh air chamber R3, and the lower portions of the front and rear side walls and the left and right side walls. It is integrally formed.

  The fresh air chamber upper 50 is a member constituting the upper part of the fresh air chamber R3, and includes an upper main body 51, a pipe mounting portion 52, and a partition wall portion 53.

  The upper main body 51 is a member that constitutes the upper wall of the fresh air chamber R3 and the upper and lower side walls and the upper portions of the left and right side walls. The pipe attachment portion 52 is a hole formed in the rear wall of the upper main body portion 51, and a fresh air passage 2y that is a pipe that connects the fresh air chamber R3 and the upstream side of the compressor 2b so that blow-by gas can flow therethrough. It is attached. The partition wall portion 53 is a wall portion that partitions the fresh air chamber upper 50 and the guide passage upper 21 a formed integrally with the fresh air chamber upper 50.

<Swivel unit>
As shown in FIG. 6A, the fresh air chamber R <b> 3 includes a turning portion 62. The swivel unit 62 spirally swirls the blow-by gas flowing through the fresh air chamber R3, and includes a plurality of upper ribs 62a and a plurality of lower ribs 62b.

  The upper rib 62a is erected downward from the inner surface of the breather chamber upper 30 of the fresh air chamber R3, and the lower rib 62b is erected upward from the fresh air chamber lower 14c of the fresh air chamber R3. ing. The upper rib 62a and the lower rib 62b are formed so as to incline at positions substantially intersecting at the center of the rib so as to have an X shape in a plan view. A vortex-like flow swirling up and down in R3 is formed.

<Operation example>
Subsequently, an operation example of the breather system 1 of the internal combustion engine E will be described in the order of the negative pressure state of the intake passage and the positive pressure state of the intake passage.

<Gas-liquid separation in the negative pressure state of the intake passage>
In FIG. 4, black arrows indicate the directions in which fresh air and blow-by gas flow. In FIGS. 5A, 5B, 6B, and 8, black arrows indicate the flow direction of blow-by gas, and dotted arrows indicate the flow direction of oil gas-liquid separated from blow-by gas. Represent.

  As shown in FIG. 4, the blowby gas leaking from the combustion chamber into the crankcase is introduced into the first gas-liquid separation chamber R2a of the breather chamber R2 through the breather passage R0a and the guide passage R1a (FIG. 6 ( b)) and the first gas-liquid separation chamber R2a of the breather chamber R2 through the breather passage R0b and the guide path R1b (see FIG. 8). The oil gas-liquid separated from the blow-by gas flowing through the guide path R1a flows through the bottom surface of the guide path R1a and is returned into the internal combustion engine E body through the first oil return hole 14e.

  The blow-by gas introduced into the first gas-liquid separation chamber R2a flows through the first gas-liquid separation chamber R2a from the other end side in the cylinder row direction to one end side in the cylinder row direction, and is introduced into the communication path R2c. Oil separated from the blow-by gas flowing through the first gas-liquid separation chamber R2a flows through the bottom surface of the first gas-liquid separation chamber R2a from one end in the cylinder row direction to the other end in the cylinder row direction. It is returned into the internal combustion engine E body through the return hole 14e (see FIG. 5A).

  The blow-by gas introduced into the communication path R2c flows through the communication path R2c and is introduced into the PCV valve 41 provided in the communication path R2c.

  Of the oil mist contained in the blow-by gas introduced into the PCV valve 41, the oil mist having a relatively large particle size is removed from the blow-by gas when passing through the flow path in the PCV valve 41. The oil removed while passing through the PCV valve 41 is discharged downward from the blow-by gas outlet 41a of the PCV valve 41, and the inside of the internal combustion engine E body through the second oil return hole portion 14f (see FIG. 5B). Returned to

  Of the oil mist contained in the blow-by gas introduced into the PCV valve 41, the oil mist having a relatively small particle size sticks to each other by passing through a narrow passage in the PCV valve 41 and has a large particle size. And introduced into the second gas-liquid separation chamber R2b. The oil mist having such a large particle size is easily subjected to gas-liquid separation in the second gas-liquid separation chamber R2b. The blow-by gas introduced into the second gas-liquid separation chamber R2b flows through the second gas-liquid separation chamber R2b from one end side in the cylinder row direction to the other end side in the cylinder row direction.

  The blow-by gas flowing through the second gas-liquid separation chamber R2b is circulated as a spiral swirl flow by the swirl unit 61 in the second gas-liquid separation chamber R2b. The oil mist contained in the blow-by gas adheres to each other by the centrifugal force of the swirling flow to become an oil mist having a larger particle size and is separated into gas and liquid. The gas-liquid separated oil flows through the bottom surface of the second gas-liquid separation chamber R2b from the cylinder row direction other end side to the cylinder row direction one end side, and passes through the second oil dropping hole 14f (see FIG. 5B). Through the internal combustion engine E.

<Positive pressure state of intake passage>
In FIG. 7, the black arrow represents the direction in which blow-by gas flows. In FIG. 6A, the black arrow represents the direction in which the blow-by gas flows, and the dotted arrow represents the direction in which the oil separated from the blow-by gas flows.

  In the positive pressure state of the intake passage 2x, the one-way valve 42 is closed. In this case, gas-liquid separation by the breather chamber R2 is not performed. When the intake passage 2x is in a positive pressure state, the internal combustion engine E is at a high speed and the supercharger is operating, so no negative pressure is generated in the intake passage 2x. When the pressure in the main body increases, blow-by gas is introduced into the fresh air chamber R3, and the blow-by gas is supercharged in the suction passage 2x after the oil and gas are separated in the fresh air chamber R3. It returns to the upstream side of the compressor 2b of the machine. That is, as shown in FIG. 7, the blow-by gas in the internal combustion engine E body is introduced from the oil return hole 14d into the fresh air chamber R3. The blow-by gas introduced into the fresh air chamber R3 flows through the fresh air chamber R3 from the other end side in the cylinder row direction to one end side in the cylinder row direction, and is connected to the compressor of the supercharger in the intake passage 2x via the pipe mounting portion 52. 2b is returned to the upstream side.

  The blow-by gas that circulates in the fresh air chamber R3 is circulated as a spiral swirl flow in the vertical direction by the swirl unit 62 in the fresh air chamber R3. The oil mist contained in the blow-by gas adheres to each other by the centrifugal force of the swirling flow to become an oil mist having a larger particle size and is separated into gas and liquid. The oil that has been gas-liquid separated in the fresh air chamber R3 flows through the bottom surface of the fresh air chamber R3 from one end side in the cylinder row direction to the other end side in the cylinder row direction, and the oil return hole 14d (see FIG. 6A). ) To return to the internal combustion engine E main body.

<Oil level gauge insertion hole and oil level gauge>
Next, the oil level gauge insertion hole and the oil level gauge in the breather system 1 of the internal combustion engine E will be described. As shown in FIG. 8, the breather passage R0a also serves as an oil level gauge insertion hole R4 through which the oil level gauge 70 is inserted. The breather passage R0a branches from the oil level gauge insertion hole R4 in the vicinity of the upper end of the oil level gauge insertion hole R4, and is connected to the guide path R1a through the branch passage R0a1 so that blow-by gas can flow.

  Further, the head cover 14 includes an oil level gauge guide hole portion 14h formed at a position facing the upper end portion of the oil level gauge insertion hole portion R4.

  The oil level gauge 70 includes a gauge portion 71, a bulging portion 72, a large diameter portion 73, a flange portion 74, and a handle portion 75.

  The gauge part 71 is a part that is inserted into the oil level gauge insertion hole R4, and measures the amount of oil in the oil pan 15 by the oil in the oil pan 15 adhering to the tip part (lower end part). It is a part.

  In the state where the oil level gauge 70 is inserted into the oil level gauge insertion hole R4, the bulging part 72 is located above the branching point of the oil level gauge insertion hole R4 with the branch passage R0a1 and the oil level gauge insertion hole R4. An annular flange for closing the inner peripheral surface or for making the gap between the oil level insertion hole portion R4 and the bulging portion 72 very small.

  The large diameter portion 73 is provided at the base end portion of the gauge portion 71, and is a portion that is accommodated in the oil level gauge guide hole portion 14h in a state where the oil level gauge 70 is inserted into the oil level gauge insertion hole portion R4. And a plurality of seal members for sealing the gap between the oil level gauge guide hole 14h and the inner periphery are attached to the outer peripheral surface.

  The flange portion 74 is provided on the opposite side to the gauge portion 71 of the large diameter portion 73, and the upper end of the oil level gauge guide hole portion 14h in a state where the oil level gauge 70 is inserted into the oil level gauge insertion hole portion R4. It is a site | part contact | abutted to the periphery of a part.

  The handle portion 75 is provided on the opposite side of the flange portion 74 from the large-diameter portion 73 and is a ring that the user has when operating the oil level gauge 70.

  Further, as shown in FIGS. 9 and 10, the head cover 14 includes flange portions 14i and 14j. The flange portion 14i is erected downward from the bottom surface of the head cover 14, and is a substantially cylindrical portion that covers between the oil level gauge guide hole portion 14h and the oil level gauge insertion hole portion R4. The flange portion 14j is a cylindrical portion that is erected downward from the bottom surface of the head cover 14 and covers the lower end edge of the oil dropping hole portion 14d.

  The flanges 14i and 14j have a guide path R1a on the head cover 14 side that is formed in the vicinity of a rotating cam piece that is integrally formed with a valve mechanism, in this embodiment, a camshaft, to reduce the size of the internal combustion engine. The oil splashed into the valve operating chamber by the cam piece is prevented from being sucked together with the blow-by gas flow from the guide path R1a and the oil dropping hole portion 14d.

  In the present embodiment, the guide path R1a on the head cover 14 side has a passage area larger than that of the oil level gauge insertion hole R4 so that the blow-by gas flow is easily introduced into the branch passage R0a1 branched from the oil level gauge insertion hole R4. Since it expands, it is possible to introduce the blow-by gas flow into the breather chamber R2 well while preventing the scattered oil from being mixed into the blow-by gas flow by the flange 14i, so that scavenging performance and gas-liquid separation performance are achieved. Can be further improved.

  Further, an oil level gauge guide is provided by providing a bulging portion 72 provided in the oil level gauge 70 directly above the branching location where the blow-by gas flowing through the oil level gauge insertion hole R4 flows into the branch passage R0a1. The blow-by gas is prevented from flowing toward the hole 14h side, and is favorably branched to the branch passage R0al side. The bulging portion 72 also has an oil level gauge 70 by attaching an oil mist to the bulging portion 72 even when oil splashing in the valve chamber has scattered around the oil level gauge guide hole portion 14h. It also has a function of preventing oil from adhering to the gauge part 71 at the time of desorption.

In the breather system 1 of the internal combustion engine E according to the embodiment of the present invention, the breather chamber 30 is separated into substantially two gas-liquid separation chambers by the PCV valve 41. Therefore, when the blowby gas passes through the PCV valve 41, The oil mist having a large particle diameter is removed from the blow-by gas when flowing through the PCV valve 41, and the oil mist having a relatively small particle diameter sticks to each other by passing through a narrow passage in the PCV valve 41. The oil mist having a large particle size is introduced into the second gas-liquid separation chamber R2b. The oil mist having such a large particle size is easily subjected to gas-liquid separation in the second gas-liquid separation chamber R2b.
Also, in the breather system 1 of the internal combustion engine E, the swirl 61 in the second gas-liquid separation chamber R2b makes a spiral swirl flow in the second gas-liquid separation chamber R2b while the blowby gas swirls in the vertical direction. Therefore, the oil mist contained in the blow-by gas adheres to each other by the centrifugal force of the swirling flow and becomes an oil mist having a larger particle size, which is separated into gas and liquid, thereby improving the gas-liquid separation performance.
Further, in the breather system 1 of the internal combustion engine E, since the one-way valve 42 is provided at the blow-by gas outlet of the second gas-liquid separation chamber R2b, the supercharger operates to bring the intake passage 2x into a positive pressure state. In this case, the backflow of fresh air from the intake passage 2x to the breather chamber R2 can be prevented, and the pressure adjustment performance and scavenging performance in the internal combustion engine E main body can be suitably maintained.

  Further, the breather system 1 of the internal combustion engine E is configured such that when blow-by gas inside the internal combustion engine E is supplied to the intake passage 2x by intake negative pressure, the fresh air chamber R3 causes the internal combustion engine E to flow by the negative pressure inside the internal combustion engine E. In addition to being able to scavenge the inside of the internal combustion engine E satisfactorily, the intake passage 2x is opened by the compressor 2b of the supercharger when the supercharger is operated at the time of high load and high rotation of the internal combustion engine E. In the case of a positive pressure state, the one-way valve 42 of the breather chamber R2 is closed and blow-by gas does not flow through the breather chamber R2, so blow-by gas may flow into the fresh air chamber R3. Since the fresh air chamber R3 having the swirl part 62 functions as a gas-liquid separation chamber and can be satisfactorily separated into gas and liquid, the blow-by gas from which oil has been removed is supplied to the intake passage 2 The pressure inside the internal combustion engine E body is prevented from increasing while preventing oil from adhering to the intake passage 2x, and the scavenging performance inside the internal combustion engine E body can be suitably maintained. it can.

  Further, in the breather system 1 of the internal combustion engine E, the ribs 61a, 61b, 62a, 62b of the swivel portions 61, 62 swirl the blow-by gas so as to draw a spiral in the vertical direction. Even when the length is short and the passage diameters of the chambers R2 and R3 are small, sufficient gas-liquid separation performance can be realized by centrifugal force. Furthermore, since the head cover 14, the breather chamber R2, and the fresh air chamber R3 can be reduced in size, the internal combustion engine E can be reduced in size.

Further, in the breather system 1 of the internal combustion engine E, when the intake passage 2x during the operation of the supercharger is in a positive pressure state, the one-way valve 42 provided in the breather chamber R2 is closed and the blow-by gas flow Even in a state in which the gas has almost stopped, the oil that has been gas-liquid separated in the guide passage R1a and the first gas-liquid separation chamber R2a can be quickly returned from the first oil return hole 14e to the internal combustion engine E body, Further, the oil accumulated inside the second gas-liquid separation chamber R2b can be quickly returned into the internal combustion engine E body from the second oil return hole 14f.
Further, when the intake passage 2x is in a negative pressure state when the supercharger at the time of low rotation or medium rotation of the internal combustion engine E is not operating, blow-by gas flowing into the first gas-liquid separation chamber R2a Therefore, even if the first oil return hole 14e is formed in the vicinity of the connection position with the guide path R1a, the gas-liquid separated oil around the first oil return hole 14e is blow-by gas. Since the amount of the oil wound up and mixed is small, and the first oil return hole portion 14e is provided at a position away from the PCV valve 41, the oil in the first gas-liquid separation chamber R2a is stored near the PCV valve 41. Thus, it is possible to prevent the blow-by gas flowing through the PCV valve 41 from being obstructed.

  Further, the breather system 1 of the internal combustion engine E is inclined so that the bottom surfaces of the first gas-liquid separation chamber R2a and the second gas-liquid separation chamber R2b are lowered toward the oil return holes 14e, 14f. The oil that has been gas-liquid separated inside the first gas-liquid separation chamber R2a and the second gas-liquid separation chamber R2b can be quickly returned into the internal combustion engine E body through the oil return holes 14e, 14f.

Further, in the breather system 1 of the internal combustion engine E, the PCV valve 41 that also serves as a communication path between the first gas-liquid separation chamber R2a and the second gas-liquid separation chamber R2b extends along the extending direction of the second gas-liquid separation chamber R2b. Since it is provided, the width of the head cover 14 in the direction perpendicular to the cylinder row can be designed to be compact, and both the miniaturization of the breather chamber 30 and the securing of suitable gas-liquid separation performance can be achieved.
In addition, the breather system 1 of the internal combustion engine E has a blow-by gas discharged from the PCV valve 41 to the second gas-liquid separation chamber R2b passing through a narrow flow path inside the PCV valve 41 so that the flow velocity is increased from the blow-by gas outlet 41a. As the oil flows out and hits the rib 35 disposed opposite to the blow-by gas outlet 41a of the PCV valve 41, fine oil mist adheres to the rib and falls with an increased particle size, further improving the gas-liquid separation performance Can be made.

  Further, in the breather system 1 of the internal combustion engine E, the plurality of breather passages R0a and R0b are provided at positions where the depths of the oil pans 15 are different. Even when some of the breather passages are submerged in an inclined state, blow-by gas can be introduced into the breather chamber 30 from the remaining breather passages, and pressure adjustment inside the internal combustion engine E can be suitably performed. As a result, the pressure increases due to the increase in blow-by gas inside the internal combustion engine E, particularly in the crankcase, and the increase in friction can be suppressed.

Further, in the breather system 1 of the internal combustion engine E, the breather passage R0a and the oil level gauge insertion hole R4 are used as one hole, so that the processing is easy and the internal combustion engine E can be downsized. Can do.
Further, since the breather system 1 of the internal combustion engine E is provided with the flange portions 14i and 14j, blowby gas oil mist flowing through the breather passage R0a adheres to the upper end of the oil level gauge insertion hole R4, It is possible to prevent oil falling from the oil drop hole 14d from splashing and adhering to the upper end of the oil level gauge insertion hole R4. That is, the breather system 1 of the internal combustion engine E prevents oil unrelated to measurement from adhering to the gauge part 71 of the oil level gauge 70 at the upper end of the oil level gauge insertion hole R4 when the oil level gauge 70 is attached or detached. A suitable measurement of the oil level can be realized.

  Further, the breather system 1 of the internal combustion engine E causes the oil to adhere to the bulging portion 72 even if oil adheres to the upper end portion of the oil level gauge insertion hole R4. Can be prevented from adhering to the gauge part 71 of the oil level gauge 70, and a suitable measurement of the oil level can be realized.

<Other embodiments>
Then, the breather system of the internal combustion engine which concerns on other embodiment of this invention is demonstrated centering on difference with the above-mentioned breather system 1. FIG. FIG. 11 is a plan view showing a breather system according to another embodiment of the present invention. 12 is a cross-sectional view taken along arrow X9 in FIG. In addition, the one end side and the other end side of the cylinder row direction in other embodiments are reversed from the above-described embodiments.

  As shown in FIG. 11, in a breather system 1B of an internal combustion engine E according to another embodiment, a breather chamber R3 has a relatively large volume, and a PCV valve 41 is extended from gas-liquid separation chambers R2a and R2b. It is also possible to arrange not in the direction but in a direction substantially orthogonal to the blow-by gas flow direction in the gas-liquid separation chambers R2a and R2b. Further, in the breather system 1B, the first gas-liquid separation chamber R2a is also provided with a swirling portion 63 similar to the swirling portions 61 and 62 described above. In addition, the first gas-liquid separation chamber R2a according to another embodiment is provided behind the second gas-liquid separation chamber R2b.

  As shown in FIG. 12, when the internal combustion engine E is placed horizontally such that the bottom surfaces of the chambers R2 and R3 are inclined in the direction perpendicular to the cylinder row direction, the first gas-liquid separation chamber is used. It is also possible to cause the oil separated from the gas and liquid in R2a to flow down in the PCV valve 41 toward the second gas-liquid separation chamber R2b on the lower side in the tilt direction, and to separate into the first gas-liquid separation chamber R2a. It is possible to prevent the stored oil from being stored and quickly return to the oil pan 15 (see FIG. 1) side.

  Further, the breather system 1B shown in FIG. 11 does not provide a guide path for guiding blow-by gas into the breather chamber R2 from the breather passage, and the oil return hole portion 14e from the first gas-liquid separation chamber R2a and the first gas-liquid separation. The blow-by gas introduction hole (breather passage) for introducing the blow-by gas into the chamber R2a is shared. That is, the oil return hole portion 14e is an oil return hole portion and blow-by gas inlet hole portion.

  Usually, the breather passage and the oil return hole portion 14e are formed using the dead space of the internal combustion engine, and therefore, in many cases, a plurality of locations are not provided along with the downsizing of the internal combustion engine. Often used also.

However, in the internal combustion engine E equipped with a supercharger as in the present invention, the rotational speed of the internal combustion engine E is relatively high and the amount of blow-by gas is large. Therefore, if the oil return passage and the breather passage are shared, the oil return hole portion 14e may be blocked when the amount of return oil is large, and blow-by gas may not flow into the breather chamber R2. Therefore, in the breather system 1B shown in FIG. 11, the oil that has been gas-liquid separated from the blow-by gas at a position above the oil return hole 14e and in the direction of flowing down the bottom surface of the first gas-liquid separation chamber R2a. An auxiliary opening 14g is formed at a position different from the upstream side of the oil return hole 14e.
As a result, the auxiliary opening 14g is positioned substantially above the upper end of the breather passage of the internal combustion engine body, so that the blow-by gas can be discharged from the auxiliary opening 14g in the vicinity of the oil return hole 14e closed by the return oil. It can be introduced into the chamber R2.

  As mentioned above, although embodiment of this invention was described, this invention is not limited to the said embodiment, In the range which does not deviate from the summary of this invention, it can change suitably. For example, the orientation in a state where the internal combustion engine E is mounted on the vehicle is not limited to the illustrated one. Further, the second oil return hole portion 14f may be formed at one end in the cylinder row direction on the bottom surface of the second gas-liquid separation chamber R2b.

DESCRIPTION OF SYMBOLS 1 Breather system of an internal combustion engine 2b Compressor 14 Cylinder head 15 Oil pan 35 Rib 41 PCV valve 42 One-way valve 61, 62, 63 Turning part 61a, 62a Upper rib 61b, 62b Lower rib 70 Oil level gauge 72 Expansion Part E Internal combustion engine R0a Breather passage R0a1 Branch passage R0b Breather passage R1a Guide passage R1b Guide passage R2 Breather chamber R2a First gas-liquid separation passage R2b Second gas-liquid separation passage R2c Communication passage R3 Fresh air chamber R4 Oil level gauge insertion hole Part

Claims (10)

A breather system for an internal combustion engine having a PCV circuit that recirculates blow-by gas generated inside an internal combustion engine having a supercharger through the intake passage using intake negative pressure of the intake passage and uses it again for combustion. ,
A breather chamber provided on the head cover of the internal combustion engine and connected to a breather passage through which blow-by gas generated inside the internal combustion engine flows;
With
The breather chamber is
A first gas-liquid separation chamber extending in the cylinder row direction and connected to the breather passage;
A second gas-liquid separation chamber that extends in the cylinder row direction along with the first gas-liquid separation chamber, and is connected to the inside of the internal combustion engine via the intake passage;
A communication path connecting the first gas-liquid separation chamber and the second gas-liquid separation chamber on one end side in the cylinder row direction;
With
A PCV valve which is provided in the communication path and adjusts the flow rate of the blow-by gas;
A one-way valve that is provided at the other end in the cylinder row direction of the second gas-liquid separation chamber and allows only discharge of the blow-by gas from the second gas-liquid separation chamber;
With
The breather system for an internal combustion engine, wherein the second gas-liquid separation chamber includes a swirling unit that swirls blow-by gas flowing through the second gas-liquid separation chamber. A new cylinder is formed in the upper part of the head cover of the internal combustion engine so as to extend in the cylinder row direction along with the breather chamber, introduces fresh air using negative pressure inside the internal combustion engine, and scavenges the inside of the internal combustion engine. Equipped with a care chamber,
The fresh air chamber is
The cylinder row direction one end is connected to the inside of the internal combustion engine, and the cylinder row direction other end is connected to the upstream side of the supercharger of the intake passage,
The breather system for an internal combustion engine according to claim 1, further comprising: a swirling unit that swirls fresh air flowing through the fresh air chamber and the blow-by gas. The swivel portion includes a lower rib extending from a bottom surface of the chamber provided with the swivel portion toward a ceiling inner surface of the chamber, and an upper rib extending from the ceiling inner surface of the chamber toward the bottom surface of the chamber. And comprising
The breather system for an internal combustion engine according to claim 1 or 2, wherein the lower rib and the upper rib are arranged to face each other so as to exhibit an X shape in a plan view. . A guide path that is provided in the head cover of the internal combustion engine and that connects a breather passage through which blow-by gas generated inside the internal combustion engine flows, and the breather chamber;
The first gas-liquid separation chamber is connected to the guide path on the other end side in the cylinder row direction,
A first oil return hole formed at the other end of the bottom of the first gas-liquid separation chamber in the cylinder row direction;
A second oil return hole formed at one end of the bottom of the second gas-liquid separation chamber in the cylinder row direction or at the second gas-liquid separation chamber side end of the bottom of the communication path;
The breather system for an internal combustion engine according to any one of claims 1 to 3, further comprising: The first gas-liquid separation chamber is
An oil return hole and blow-by gas inlet hole formed on the bottom surface on the other end side in the cylinder row direction;
When the internal combustion engine is mounted on a vehicle, the position is higher than the oil return hole and blow-by gas inlet hole, and is different from the upstream side in the direction in which oil separated from the blow-by gas flows down. An auxiliary opening for introducing blow-by gas into the first gas-liquid separation chamber at a position;
The breather system for an internal combustion engine according to any one of claims 1 to 3, further comprising: The bottom surface of the first gas-liquid separation chamber is inclined downward from one end of the cylinder row to the other end of the cylinder row in a state where the internal combustion engine is mounted on the vehicle,
The bottom surface of the second gas-liquid separation chamber is inclined downward from the other end side of the cylinder row to the one end side of the cylinder row in a state where the internal combustion engine is mounted on the vehicle. 6. A breather system for an internal combustion engine according to claim 5. The PCV valve is provided along the extending direction of the second gas-liquid separation chamber at the second gas-liquid separation chamber side end of the communication path,
The rib which opposes the blow-by gas outlet of the PCV valve is formed in the second gas-liquid separation chamber with a predetermined gap with respect to the blow-by gas outlet. A breather system for an internal combustion engine according to any one of the above. A plurality of sets of the breather passages and the guide passages;
The internal combustion engine according to any one of claims 1 to 3, wherein the plurality of breather passages are provided at positions where oil pans provided at the bottom of the internal combustion engine have different depths. Institutional breather system. The breather passage also serves as an oil level gauge insertion hole,
An upper end portion of the breather passage is branched from the oil level gauge insertion hole portion and connected to the guide path,
The head cover is
An oil level gauge guide hole facing the tip of the oil level gauge insertion hole,
A flange that covers between the oil level gauge guide hole and the oil level gauge insertion hole,
The breather system for an internal combustion engine according to any one of claims 1 to 3, further comprising: The breather system for an internal combustion engine according to claim 9, wherein the oil level gauge includes a bulging portion that closes the oil level gauge insertion hole above a position branched from the breather passage.

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