JP2016065472A - Oil separation structure of internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an oil separation structure of an internal combustion engine capable of guiding a blow-by gas flowing into a first oil separation chamber and a second oil separation chamber to a third oil separation chamber by using a common blow-by gas passage, and miniaturizing the oil separation chambers.SOLUTION: In an oil separation structure, an oil separation chamber 41 and an oil separation chamber 42 are partitioned by a partitioning wall 45A disposed on a case portion 40, and a partitioning wall 53 disposed on a cover member 51 and butted to the partitioning wall 45A, the partitioning wall 53 has a communication hole 53a for circulating a blow-by gas flowing into the oil separation chamber 41, from an inflow port 41A to the oil separation chamber 42, and the cover member 51 is positioned on the oil separation chamber 42 in a state of being opposed to the communication hole 53a, and has a collision wall 56 with which the blow-by gas flowing into the oil separation chamber 42 through the communication hole 53a, collides.SELECTED DRAWING: Figure 8

Description

  The present invention relates to an oil separation structure for an internal combustion engine, and more particularly to an oil separation structure for an internal combustion engine that separates oil from blow-by gas.

  Conventionally, as an oil separation structure of an internal combustion engine mounted on an automobile or the like, a plurality of blow-by gas passages having different passage cross-sectional areas communicating between a crank chamber and a breather chamber of a cylinder head are provided between cylinders. The thing connected by the communication room is known (for example, refer patent document 1).

  The oil separation structure of this internal combustion engine makes it difficult to carry oil mist from the crank chamber to the breather chamber by dropping the flow rate of the blow-by gas passage, which has a large flow rate, among the plurality of blow-by gas passages through the communication chamber. Is prevented from falling.

Japanese Patent No. 3859041

  However, such a conventional oil separation structure for an internal combustion engine has a plurality of blow-by gas passages that connect the crank chamber and the breather chamber of the cylinder head, so that the structure of the oil separation chamber is complicated.

  In addition, in the breather chamber formed in the cylinder head, a structure for effectively separating oil from blow-by gas is not disclosed, and what kind of passage structure does oil flow into the breather chamber from a plurality of blow-by gas passages. I can't know how to separate them in my breather room.

  The present invention has been made paying attention to the above-described problems, and the blow-by gas flowing into the first oil separation chamber and the second oil separation chamber is converted into the first by using a common blow-by gas passage. It is an object of the present invention to provide an oil separation structure for an internal combustion engine that can be guided to the oil separation chamber 3 and that can reduce the size of the oil separation chamber.

  In the present invention, a plurality of oil separation chambers for separating oil from blow-by gas are formed by the case portion and the cover member that closes the case portion, and the oil separation chamber is provided with blow-by gas introduced from the first inlet. 1 oil separation chamber, adjacent to the first oil separation chamber, adjacent to the second oil separation chamber into which blow-by gas is introduced from the second inlet, and adjacent to the second oil separation chamber, An oil separation structure for an internal combustion engine comprising a third oil separation chamber provided downstream of the second oil separation chamber in the direction in which blow-by gas flows, wherein the first oil separation chamber And the second oil separation chamber is partitioned by a case side partition wall provided in the case portion and a first cover side partition wall provided in the cover member and abutted against the case side partition wall, Hippopotamus The side partition wall has a communication hole through which blow-by gas flowing into the first oil separation chamber from the first inflow port flows into the second oil separation chamber, and the cover member is opposed to the communication hole. A collision wall provided in the second oil separation chamber and colliding with blow-by gas flowing into the second oil separation chamber through the communication hole; the cover member has a second cover side partition wall; The cover-side partition wall has a third surface facing the second surface of the collision wall opposite to the first surface of the collision wall facing the communication hole, The blow-by gas passage formed by the third surface of the second cover-side partition wall is configured to guide blow-by gas from the first oil separation chamber and the second oil separation chamber to the third oil separation chamber. Has been.

  According to the present invention, the first cover side partition wall has the communication hole through which the blow-by gas flowing into the first oil separation chamber from the first inflow port flows into the second oil separation chamber, and the cover member Is provided in the second oil separation chamber so as to face the communication hole, and has a collision wall on which blow-by gas flowing into the second oil separation chamber through the communication hole collides.

  Thus, the oil can be easily separated from the blow-by gas by causing the blow-by gas flowing into the first oil separation chamber from the first inflow port to collide with the collision wall after increasing the flow velocity through the communication hole.

  Further, the second cover side partition wall formed on the cover member has a third surface facing the second surface of the collision wall opposite to the first surface of the collision wall facing the communication hole. The third oil separation chamber from the first oil separation chamber and the second oil separation chamber by the blow-by gas passage formed by the second surface of the collision wall and the third surface of the second cover side partition wall Guide the blow-by gas.

  As a result, the blow-by gas flowing into the first oil separation chamber and the second oil separation chamber is formed by the second surface of the collision wall and the third surface of the second cover side partition wall. The blow-by gas passage can guide to the third oil separation chamber.

  For this reason, it is unnecessary to separately form a blow-by gas passage for guiding the blow-by gas from the first oil separation chamber and the second oil separation chamber to the third oil separation chamber. As a result, the oil separation chamber can be reduced in size.

FIG. 1 is a diagram showing an embodiment of an oil separation structure for an internal combustion engine according to the present invention, and is a schematic configuration diagram of a blow-by gas processing apparatus. FIG. 2 is a view showing an embodiment of the oil separation structure of the internal combustion engine of the present invention, and is a front view of the internal combustion engine provided with the blow-by gas processing device. FIG. 3 is a view showing an embodiment of the oil separation structure for an internal combustion engine of the present invention, and is a cross-sectional view taken along the line III-III in FIG. FIG. 4 is a view showing an embodiment of the oil separation structure of the internal combustion engine of the present invention, and is a perspective view of the internal combustion engine provided with the blow-by gas processing device with the cylinder head cover and the chain case removed. FIG. 5 is a view showing an embodiment of the oil separation structure of the internal combustion engine of the present invention, and is a perspective view of the cylinder block with the cover member removed. FIG. 6 is a view showing an embodiment of the oil separation structure of the internal combustion engine of the present invention, and is an enlarged view of the oil separation chamber. FIG. 7 is a view showing an embodiment of an oil separation structure for an internal combustion engine according to the present invention, and is a perspective view of a cover member. FIG. 8 is a view showing an embodiment of the oil separation structure of the internal combustion engine of the present invention, and is a perspective view of an oil separation chamber showing a part of a cover member in cross section. FIG. 9 is a view showing an embodiment of the oil separation structure for an internal combustion engine of the present invention, and is a perspective view of an oil separation chamber showing a part of a cover member in cross section. FIG. 10 is a view showing an embodiment of an oil separation structure for an internal combustion engine of the present invention, and is a view showing a flow of oil separated from blow-by gas and blow-by gas in an oil separation chamber. FIG. 11 is a view showing an embodiment of the oil separation structure of the internal combustion engine of the present invention, and is a perspective view of a cylinder block to which a cover member is attached. 12 is a view showing an embodiment of the oil separation structure of the internal combustion engine of the present invention, and is a cross-sectional view taken along the XII-XII direction of FIG. FIG. 13 is a view showing an embodiment of the oil separation structure of the internal combustion engine of the present invention, and is a view showing a state where blow-by gas stays in the oil separation chamber.

Hereinafter, an embodiment of an oil separation structure for an internal combustion engine according to the present invention will be described with reference to the drawings.
FIGS. 1-13 is a figure which shows the oil separation structure of the internal combustion engine of one Embodiment which concerns on this invention.
First, the configuration will be described. 1 to 11, the left and right front-rear direction represents the left and right front-rear direction of the vehicle as viewed from the driver's seat.

  1 to 4, an engine 1 as an internal combustion engine includes a cylinder block 2, a cylinder head 3 provided on the top of the cylinder block 2, a cylinder head cover 4 provided on the top of the cylinder head 3, and a cylinder block. 2 is provided with an oil pan 5 provided at a lower portion.

  In FIG. 1, the cylinder block 2 accommodates a piston 28 that is accommodated in a cylinder 27 so as to be movable up and down, a crankshaft 6 that converts the vertical motion of the piston 28 into a rotational motion, and the like. Is integrally provided with a crankcase 2A that rotatably supports the crankshaft 6. A crank chamber 24 is formed between the crankcase 2 </ b> A and the oil pan 5.

  1 and 4, the cylinder head 3 extends in the arrangement direction of the cylinders 27, and is arranged in parallel with the intake camshaft 7 as a camshaft provided with the intake cam 7 a and the intake camshaft 7. And an exhaust camshaft 8 as a camshaft provided with an exhaust cam 8a.

  In the engine 1 of the present embodiment, a space between the cylinder head 3 and the cylinder head cover 4 in which the intake camshaft 7 and the exhaust camshaft 8 are housed constitutes a valve operating chamber 13. The intake camshaft 7 and the exhaust camshaft 8 are rotatably supported on the cylinder head 3 by a plurality of cam caps 3A.

  In FIG. 1, an intake port 29 and an exhaust port 30 are formed in the cylinder head 3, and the intake port 29 and the exhaust port 30 are driven by an intake valve 31 and an exhaust valve 31 that are driven as the intake cam 7 a and the exhaust cam 8 a rotate. The exhaust valve 32 is opened and closed.

An intake manifold 33 is attached to the cylinder head 3, and an air cleaner 35 is connected to the intake manifold 33 via an intake pipe 34. The air cleaner 35 purifies the intake air Ai taken from the outside. The intake air Ai purified by the air cleaner 35 is sucked into the intake manifold 33 from the intake pipe 34, and each intake port 29 from the intake manifold 33. Are distributed to each cylinder 27 through the intake.
The intake pipe 34 is provided with a throttle valve 34 </ b> A, and this throttle valve 34 </ b> A adjusts the amount of air taken into the cylinder 27.

  In FIG. 4, an intake cam sprocket 9 is provided at the end of the intake camshaft 7, and a timing chain 11 is wound around the intake cam sprocket 9. An exhaust cam sprocket 10 is provided at the end of the exhaust cam shaft 8, and a timing chain 11 is wound around the exhaust cam sprocket 10.

  A crank sprocket 12 is provided at the end of the crankshaft 6, and a timing chain 11 is wound around the crank sprocket 12. Thereby, the rotation of the crankshaft 6 is transmitted from the crank sprocket 12 to the intake cam sprocket 9 and the exhaust cam sprocket 10 via the timing chain 11, and the intake camshaft 7 and the exhaust camshaft 8 rotate.

  When the intake cam 7a and the exhaust cam 8a rotate, the intake valve 31 and the exhaust valve 32 open and close the intake port 29 and the exhaust port 30 (see FIG. 1), respectively, so that the combustion chamber 14 ( 1) and the intake port 29 and the exhaust port 30 are communicated and blocked. In this way, the intake chain 31 and the exhaust valve 32 are operated according to the rotation of the crankshaft 6 by the timing chain 11.

  2 and 3, a chain case 21 is provided at the ends of the cylinder block 2 and the cylinder head 3 (the front side of the engine 1). The chain case 21 covers the timing chain 11 and forms a chain housing chamber 22 between the cylinder block 2 and the chain case 21 (see FIG. 3). The chain housing chamber 22 communicates with the crank chamber 24. ing.

  5, 6, 8, and 9, the oil separation chamber 17 is formed on the side surface 2 </ b> B of the cylinder block 2, and the oil separation chamber 17 is formed on the case portion 40 formed on the side surface 2 </ b> B of the cylinder block 2. The four oil separation chambers 41 to 44 are formed by the cover member 51 (see FIG. 7) attached to the side surface 2B of the cylinder block 2.

  5 and 6, the oil separation chambers 41 to 44 include a plurality of partition walls 45 </ b> A to 45 </ b> C formed on the side surface 2 </ b> B of the cylinder block 2. The partition wall 45 </ b> A extends in the axial direction of the cylinder 27, and the partition wall 45 </ b> A partitions the case portion 40 from the oil separation chamber 41 and the oil separation chambers 42 and 43 in the axial direction of the crankshaft 6. Thereby, the oil separation chamber 41 is provided adjacent to the oil separation chamber 42.

The partition wall 45 </ b> B extends in the axial direction of the crankshaft 6, and the partition wall 45 </ b> B partitions the case portion 40 from the oil separation chamber 42 and the oil separation chamber 43 in the axial direction of the cylinder 27. Thereby, the oil separation chamber 42 is provided adjacent to the oil separation chamber 43.
The partition wall 45 </ b> C extends in the axial direction of the cylinder 27, and the partition wall 45 </ b> C partitions the case portion 40 from the oil separation chamber 43 and the oil separation chamber 44 in the axial direction of the crankshaft 6.

  An inlet 41A is formed in the oil separation chamber 41, and the inlet 41A communicates with the chain housing chamber 22 through a communication passage 23 formed in the cylinder block 2. Thereby, the blow-by gas flowing from the crank chamber 24 to the chain housing chamber 22 flows into the oil separation chamber 41 from the communication passage 23 through the inlet 41A.

  An inlet 42 A is formed in the oil separation chamber 42, and the inlet 42 A communicates with the crank chamber 24 via the communication path 20 formed in the cylinder block 2. Thereby, the blow-by gas in the crank chamber 24 flows directly into the oil separation chamber 42 from the communication passage 20 through the inlet 42A.

  Here, the oil separation chamber 41 of the present embodiment constitutes a first oil separation chamber of the present invention, and the oil separation chamber 42 constitutes a second oil separation chamber of the present invention. In addition, the oil separation chamber 43 of the present embodiment constitutes a third oil separation chamber of the present invention. In addition, the inlet 41A of the present embodiment constitutes a first inlet of the present invention, and the inlet 42A constitutes a second inlet of the present invention.

  Further, the volume of the oil separation chamber 41 is formed larger than the volume of the oil separation chamber 42, and the amount of blow-by gas per unit volume accommodated in the oil separation chamber 41 of the present embodiment is the amount per unit volume. More than the amount of blow-by gas stored in the oil separation chamber 42.

  In FIG. 7, the cover member 51 includes a flat plate portion 52 and partition walls 53 to 55 protruding from the flat plate portion 52 toward the case portion 40. The flat plate portion 52 closes the case portion 40 (see FIG. 11), and the flat plate portion 52 is fixed to the side surface 2B of the cylinder block 2 by a bolt (not shown).

  8 and 9, the partition wall 53 of the cover member 51 is abutted against the partition wall 45A of the case portion 40, and the oil separation chamber 41 is separated from the oil separation chambers 42 and 43 by the partition wall 53 and the partition wall 45A. And partitioned.

  The partition wall 54 of the cover member 51 extends in the axial direction of the crankshaft 6 and extends in the axial direction of the cylinder 27 that is orthogonal to the upper wall portion 54A and the upper wall portion 54A that abuts against the partition wall 45B of the case portion 40. A vertical wall portion 54B is provided which extends and is continuous with the upper wall portion 54A, and is positioned at the center in the axial direction of the crankshaft 6 with respect to the oil separation chamber 42. Thus, the oil separation chamber 42 is separated from the oil separation chamber 43 in the axial direction of the cylinder 27 by the upper wall portion 54A.

The partition wall 55 of the cover member 51 is abutted against the partition wall 45C of the case portion 40,
The oil separation chamber 43 is partitioned from the oil separation chamber 44 by the partition wall 55 and the partition wall 45C.

  Here, the partition wall 45A of the case portion 40 of the present embodiment constitutes the case-side partition wall of the present invention. Further, the partition wall 53 of the cover member 51 constitutes a first cover side partition wall of the present invention, and the partition wall 54 of the cover member 51 constitutes a second cover side partition wall of the present invention.

  A pair of communication holes 53a (see FIG. 12) is formed in the partition wall 53, and the communication holes 53a circulate blow-by gas flowing into the oil separation chamber 41 from the inlet 41A to the oil separation chamber.

  In FIG. 7, the cover member 51 has a collision wall 56, and the collision wall 56 protrudes from the flat plate portion 52 toward the case portion 40. 8 and 9, the collision wall 56 is located in the oil separation chamber 42 so as to face the communication hole 53a of the partition wall 53. The collision wall 56 flows into the oil separation chamber 42 through the communication hole 53a. The blow-by gas that collides.

  That is, the collision wall 56 is provided downstream of the partition wall 53 in the flow direction of blow-by gas. Further, since one side surface of the collision wall 56 with respect to the direction orthogonal to the axial direction of the crankshaft 6 (the left-right direction of the vehicle) is not abutted against the partition wall 45A, the blow-by gas that collided with the collision wall 56 is separated from the partition wall. The oil flows into the oil separation chamber 42 from the space between 45A and the collision wall 56.

  The vertical wall portion 54B of the cover member 51 has a third surface 54b facing the second surface 56b of the collision wall 56 opposite to the first surface 56a of the collision wall 56 facing the communication hole 53a. Thereby, the blow-by gas passage 57 is formed by the second surface 56b of the collision wall 56 and the third surface 54b of the vertical wall portion 54B, and the oil separation chambers 41 and 42 are moved from the oil separation chambers 41 and 42 to the oil separation chamber 43 by the blow-by gas passage 57. Blow-by gas is guided.

  In the oil separation chamber 17 of the present embodiment, the oil separation chamber 41 is provided on the chain housing chamber 22 side with respect to the oil separation chambers 42 and 43. The oil separation chamber 44 is provided adjacent to the oil separation chamber 43 on the side opposite to the oil separation chamber 41.

  8 and 9, a communication hole 55 a is formed in the partition wall 55. The cover member 51 has a collision wall 58, and the collision wall 58 protrudes from the flat plate portion 52 toward the case portion 40.

  The collision wall 58 is positioned in the oil separation chamber 44 so as to face the communication hole 55a of the partition wall 55, and blow-by gas that flows into the oil separation chamber 44 through the communication hole 55a collides with the collision wall 58. That is, the collision wall 58 is provided downstream of the partition wall 55 in the flow direction of blow-by gas.

  In addition, since one side surface of the collision wall 58 with respect to the direction orthogonal to the axial direction of the crankshaft 6 is not abutted against the partition wall 45C, blow-by gas that collides with the collision wall 58 is separated from the partition wall 45C and the collision wall 58. Flows into the oil separation chamber 44 from the space between the two.

  7, 8, and 12, a notch 53b is formed at the bottom of the partition wall 53 of the cover member 51. The oil separated from the blow-by gas in the oil separation chamber 41 is separated from the notch 53b. The oil flows into the oil separation chamber 42 through a gap between the bottom surface of the chamber 41.

  The bottom surfaces of the oil separation chambers 41 and 42 are inclined downward from above toward the inlet 42A of the oil separation chamber 42 from the front of the vehicle. As a result, the oil that has flowed into the oil separation chamber 42 from the oil separation chamber 41 flows into the inlet 42 </ b> A along the bottom surface of the oil separation chamber 42.

7 and 8, a notch 55 b is formed at the bottom of the partition wall 55 of the cover member 51. The oil separated from the blow-by gas in the oil separation chamber 44 flows into the oil separation chamber 42 through the notch 55b, and the oil that flows into the oil separation chamber 42 flows into the inlet 42A.
The oil that has flowed into the inflow port 42 </ b> A is returned to the oil pan 5 from the communication path 20 through the crank chamber 24.

  7 to 9 and 11, an exhaust hole 52 a is formed in the flat plate portion 52 of the cover member 51, and the exhaust hole 52 a faces the oil separation chamber 44.

  In FIG. 1, the exhaust hole 52 a communicates with the intake manifold 33 via the blow-by gas discharge pipe 36, and the blow-by gas that has flowed into the oil separation chamber 44 is discharged from the blow-by gas discharge pipe 36 due to the intake negative pressure of the engine 1. The air is sucked into the intake pipe 34 through the intake manifold 33.

  The blow-by gas sucked into the intake manifold 33 is introduced into the combustion chamber 14 of the engine 1 and combusted in the combustion chamber 14 together with the air-fuel mixture.

  A PCV valve 37 is provided between the oil separation chamber 44 and the blowby gas discharge pipe 36, and the PCV valve 37 adjusts the flow rate of blowby gas flowing from the oil separation chamber 44 to the blowby gas discharge pipe 36.

  In FIG. 1, the intake pipe 34 upstream of the cylinder head cover 4 and the throttle valve 34A is connected by a fresh air introduction pipe 38. The fresh air introduction pipe 38 is a part of the intake air Ai, that is, Fresh air An is introduced into the valve train chamber 13.

  A fresh air inflow passage 39 is formed in the cylinder block 2 and the cylinder head 3, and the fresh air inflow passage 39 communicates the valve operating chamber 13 and the crank chamber 24. The fresh air An introduced into the valve operating chamber 13 from the fresh air introduction pipe 38 by the suction negative pressure is introduced from the chain housing chamber 22 into the oil separation chamber 41 through the communication passage 23 and the inlet 41A.

  Further, the fresh air An introduced into the valve operating chamber 13 from the fresh air introduction pipe 38 is introduced into the oil separation chamber 42 from the fresh air inflow passage 39 through the crank chamber 24, the communication passage 20 and the inlet 42A. The blow-by gas introduced into the oil separation chambers 41 and 42 is sucked into the oil separation chamber 44 through the oil separation chamber 43 and then introduced into the cylinder 27 from the blow-by gas discharge pipe 36 through the intake manifold 33. Thereby, the inside of the engine 1 including the valve operating chamber 13, the chain housing chamber 22, and the crank chamber 24 is ventilated by the fresh air An.

Next, the operation will be described.
In FIG. 10, an arrow B indicates the flow of blow-by gas, and an arrow O indicates the flow of oil separated from the blow-by gas.

  In the chain housing chamber 22, the timing chain 11 is lubricated by oil being injected from an oil jet (not shown) into the timing chain 11. For this reason, if the chain storage chamber 22 is not sufficiently ventilated, NOx (nitrogen oxide) contained in the blow-by gas introduced into the chain storage chamber 22 reacts with moisture to generate nitric acid, and the oil The nitric acid agglomerates to generate sludge.

  This sludge is a tar-like substance, and when the sludge is mixed into the oil that lubricates the engine 1, it causes deterioration of the oil, malfunction of the hydraulic system, the crankshaft 6, the intake camshaft 7, and the exhaust cam. Lubrication failure of the sliding member such as the shaft 8 is caused, the sliding resistance of the engine 1 is increased, and the fuel consumption of the engine 1 is deteriorated.

  As shown in FIG. 3, in the engine 1 of the present embodiment, the cylinder block 2 has a communication passage 23 that communicates the oil separation chamber 41 and the chain housing chamber 22, and the communication passage 23 is oil through the inlet 41 </ b> A. The separation chamber 41 communicates.

  Thereby, blow-by gas can be flowed directly from the chain housing chamber 22 to the oil separation chamber 41. For this reason, the chain housing chamber 22 can be directly ventilated through the communication path 23, and sludge can be prevented from being generated in the chain housing chamber 22.

  The blow-by gas B flowing from the chain housing chamber 22 to the oil separation chamber 41 through the communication passage 23 flows into the oil separation chamber 41 from the inlet 41A as shown in FIG. The blow-by gas B collides with the collision wall 56 by increasing the flow velocity when the flow path is throttled through the communication hole 53a. As a result, the oil O is separated from the blowby gas B, and the separated oil O falls downward along the collision wall 56.

  The blow-by gas B from which the oil O has been separated by colliding with the collision wall 56 is separated from the space between the collision wall 56 and the partition wall 45A by the second surface 56b of the collision wall 56 and the third surface of the vertical wall portion 54B. 54 b and guided to the blow-by gas passage 57, and flows into the oil separation chamber 43.

  On the other hand, the blow-by gas B flowing from the crank chamber 24 toward the oil separation chamber 42 through the communication passage 20 flows into the oil separation chamber 42 from the inlet 42A. The blow-by gas B collides with the partition wall 45B and the upper wall portion 54A of the partition wall 54, whereby the oil O is separated from the blow-by gas B, and the separated oil O falls to the bottom surface of the oil separation chamber 42. .

  The blowby gas B from which the oil O has been separated by the partition wall 45B and the upper wall portion 54A of the partition wall 54 is guided by the blowby gas passage 57 and flows into the oil separation chamber 43.

  The blow-by gas B that has flowed into the oil separation chamber 43 is throttled by the communication hole 55a of the partition wall 55 and the flow velocity is increased. Then, the blow-by gas B collides with the collision wall 58, so that the oil O that could not be separated from the blow-by gas B To be separated.

  Next, the blow-by gas B from which the oil O has been separated flows into the oil separation chamber 44 from the space between the partition wall 45C and the collision wall 58, and then from the exhaust hole 52a of the cover member 51 by the suction negative pressure of the engine 1. The air is sucked into the combustion chamber 14 through the blow-by gas discharge pipe 36, the intake manifold 33, and the intake pipe 34 and burned together with the air-fuel mixture.

  Thus, according to the oil separation structure of the present embodiment, the partition wall 53 provided in the cover member 51 has a communication hole through which the blow-by gas flowing into the oil separation chamber 41 from the inlet 41A flows into the oil separation chamber 42. The cover member 51 has a collision wall 56 that is positioned in the oil separation chamber 42 so as to face the communication hole 53a and that collides with blow-by gas that flows into the oil separation chamber 42 through the communication hole 53a.

  As a result, the blow-by gas that has flowed into the oil separation chamber 41 from the inlet 41A is allowed to collide with the collision wall 56 after increasing the flow velocity through the communication hole 53a, so that the oil can be easily separated from the blow-by gas.

  In addition, the vertical wall portion 54B formed in the cover member 51 has a third surface facing the second surface 56b of the collision wall 56 opposite to the first surface 56a of the collision wall 56 facing the communication hole 53a. The blow-by gas is supplied from the oil separation chambers 41 and 42 to the oil separation chamber 43 by a blow-by gas passage 57 formed by the second surface 56b of the collision wall 56 and the third surface 54b of the vertical wall portion 54B. invite.

  As a result, the blow-by gas flowing into the oil separation chambers 41 and 42 is oiled by the common blow-by gas passage 57 formed by the second surface 56b of the collision wall 56 and the third surface 54b of the vertical wall portion 54B. Guide to the separation chamber 43.

  For this reason, it is unnecessary to separately form a blow-by gas passage for guiding blow-by gas from the oil separation chambers 41 and 42 to the oil separation chamber 43. As a result, the oil separation chamber 17 can be reduced in size.

  Further, according to the oil separation structure of the present embodiment, the oil separation chambers 41 to 44 provided on the side surface 2 </ b> B of the cylinder block 2 are provided on the partition walls 45 </ b> A to 45 </ b> C provided on the case portion 40 and the cover member 51. The partition walls 53-55 are abutted against the partition walls 45A-45C, and communication holes 53a, 55a through which blow-by gas flows between the oil separation chambers 41-44 are formed in the partition walls 53, 55. .

  Accordingly, the blow-by gas can be circulated between the oil separation chambers 41 to 44 through the communication holes 53a and 55a on the cover member 51 side away from the side surface 2B of the cylinder block 2. For this reason, liquefaction of the oil vapor | steam contained in blowby gas can be accelerated | stimulated by cooling blowby gas with external air. For this reason, it is possible to easily separate the oil from the blow-by gas by increasing the particle size of the oil mist, and to improve the oil separation performance.

  Further, according to the oil separation structure of the present embodiment, the first inlet 41A of the oil separation chamber 41 communicates with the chain housing chamber 22, and the oil separation chamber 42 communicates with the crank chamber 24 through the second inlet 42A. doing. Thereby, generation | occurrence | production of the sludge by aggregation of oil can be suppressed in the chain storage chamber 22 or the crank chamber 24.

  Since the oil separation structure of the present embodiment can reduce the size of the oil separation chamber 17 as described above, the communication path that communicates the chain housing chamber 22 and the crank chamber 24 with the oil separation chambers 41 and 42 to the cylinder block 2. Even if it is a case where 20 and 23 are comprised, it can suppress that the cylinder block 2 enlarges.

  In addition, the oil separation chamber 42 communicates with the crank chamber 24 and has an inlet 42A through which blow-by gas in the crank chamber 24 flows. Therefore, the oil separation chamber 41 passes through the inlet 41A and the chain housing chamber 22 and is connected to the crank chamber 24. And the oil separation chamber 42 can communicate with the crank chamber 24 through the inlet 42A.

  For this reason, when the internal pressure of the crank chamber 24 rises, the pressure in the crank chamber 24 can be released to the oil separation chambers 41 and 42 through the inflow ports 41A and 42A, and the pressure rise in the crank chamber 24 can be quickly suppressed.

  Therefore, the oil stored in the oil pan 5 can be prevented from flowing into the oil separation chambers 41 and 42, and the oil can be reliably separated from the blow-by gas in the oil separation chambers 41 and 42. As a result, oil separation performance can be improved.

  Further, according to the oil separation structure of the present embodiment, the volume of the oil separation chamber 41 is made larger than the volume of the oil separation chamber 42. As a result, the blow-by gas whose flow velocity is increased by the reciprocating motion of the piston 28 in the crank chamber 24 is introduced into the oil separation chamber 42 having a smaller volume than the oil separation chamber 41, and the partition wall 45 </ b> B and the cover member of the oil separation chamber 42. The oil can be easily separated from the blow-by gas by colliding with the upper wall portion 54A of 51 at a high speed. Further, the oil colliding with the partition wall 45B and the upper wall portion 54A falls to the bottom surface of the oil separation chamber 42.

  On the other hand, the blow-by gas introduced from the crank chamber 24 through the chain housing chamber 22 into the oil separation chamber 41 is introduced into the oil separation chamber 42 because it is less affected by the reciprocation of the piston 28 by being separated from the crank chamber 24. The flow rate is slower than blow-by gas.

  Since the oil separation chamber 41 has a larger volume than the oil separation chamber 42, blow-by gas introduced into the oil separation chamber 41 stays in the oil separation chamber 41 with a large volume and agglomerates to separate oil. Can be promoted. As a result, the oil separation performance in the oil separation chamber 41 can be improved more effectively.

  FIG. 13 is a view showing a state where the blow-by gas B stays in the oil separation chamber 41. As shown in FIG. 13, it is clear that the blow-by gas B having a low flow rate stays in the oil separation chamber 41 having a large volume and aggregates. When the blow-by gas B stays and aggregates in this way, the separation of oil from the blow-by gas B can be promoted compared to the blow-by gas that moves at high speed.

  Further, due to the restriction of the installation space of the oil separation chamber 17 with respect to the cylinder block 2, the installation space of the oil separation chamber 17 cannot be made large. In contrast, in the oil separation structure of the present embodiment, even if the volume of the oil separation chamber 42 is reduced, the oil separation performance can be improved by introducing blow-by gas having a high flow rate into the oil separation chamber 42. The entire volume of the oil separation chamber 17 can be reduced by the amount that the volume of the chamber 42 can be reduced. Therefore, the oil separation performance can be more effectively improved while reducing the installation space of the oil separation chamber 17.

  Further, according to the oil separation structure of the present embodiment, the oil separation chamber 41 is provided on the chain housing chamber 22 side with respect to the oil separation chamber 42 and the oil separation chamber 43, and the oil separation chamber 41 is disposed on the opposite side of the oil separation chamber 41. An oil separation chamber 44 is provided adjacent to the chamber 43.

  Accordingly, the oil separation chamber 17 can be formed in the cylinder block 2 so that the oil separation chamber 43 is sandwiched between the oil separation chamber 41 and the oil separation chamber 44. For this reason, the oil separation chamber 17 can be installed in the cylinder block 2 in an even smaller space.

  According to the oil separation structure of the present embodiment, the oil separation chamber 41 is communicated with the chain housing chamber 22 via the inlet 41A, and the oil separation chamber 42 is communicated with the crank chamber 24 via the inlet 42A. However, the oil separation chamber 42 may be communicated with the chain housing chamber 22 via the inlet 42A, and the oil separation chamber 41 may be communicated with the crank chamber 24 via the inlet 41A.

  While embodiments of the invention have been disclosed, it will be apparent to those skilled in the art that changes may be made without departing from the scope of the invention. All such modifications and equivalents are intended to be included in the following claims.

DESCRIPTION OF SYMBOLS 1 ... Engine (internal combustion engine), 2 ... Cylinder block, 2B ... Side surface, 3 ... Cylinder head, 11 ... Timing chain, 17 ... Oil separation chamber, 21 ... Chain case, 22 ... Chain storage chamber, 24 ... Crank chamber, 40 ... Case portion, 41 ... oil separation chamber (first oil separation chamber), 41A ... inlet (first inlet), 42 ... oil separation chamber (second oil separation chamber), 42A ... inlet (first) 2), 43 ... Oil separation chamber (third oil separation chamber), 45A ... Partition wall (case side partition wall), 51 ... Cover member, 53 ... Partition wall (first cover side partition wall), 53a ... Communication hole, 54 ... Partition wall (second cover side partition wall), 54b ... Third surface, 56 ... Collision wall, 56a ... First surface, 56b ... Second surface, 57 ... Blow-by gas passage

Claims (3)

A plurality of oil separation chambers for separating oil from blow-by gas are formed by the case portion and the cover member that closes the case portion,
The oil separation chamber is provided adjacent to the first oil separation chamber where the blow-by gas is introduced from the first inlet and the first oil separation chamber, and the blow-by gas is introduced from the second inlet. A second oil separation chamber, and a third oil separation chamber that is adjacent to the second oil separation chamber and is provided downstream of the second oil separation chamber in the direction in which blow-by gas flows. An oil separation structure for an internal combustion engine comprising:
The first oil separation chamber and the second oil separation chamber are provided in a case side partition wall provided in the case portion, and the first cover provided in the cover member and abutted against the case side partition wall Partitioned by side partition walls,
The first cover-side partition wall has a communication hole through which blow-by gas flowing from the first inflow port into the first oil separation chamber flows into the second oil separation chamber;
The cover member is provided in the second oil separation chamber so as to face the communication hole, and has a collision wall on which blow-by gas flowing into the second oil separation chamber through the communication hole collides,
The cover member has a second cover side partition wall, and the second cover side partition wall is a second side of the collision wall opposite to the first surface of the collision wall facing the communication hole. A blow-by gas passage formed by the second surface of the collision wall and the third surface of the second cover-side partition wall. An oil separation structure for an internal combustion engine, wherein blowby gas is guided from the oil separation chamber and the second oil separation chamber to the third oil separation chamber.   The case portion is provided on a side surface of the cylinder block, and one of the first inlet and the second inlet communicates with a crank chamber formed in the cylinder block. The oil separation structure of the internal combustion engine according to claim 1. A chain case that covers a timing chain that transmits a driving force of a crankshaft to a camshaft is attached to an end portion of the cylinder block and a cylinder head provided at an upper portion of the cylinder block. A chain housing chamber surrounded by the block and the cylinder head is formed;
3. The oil separation structure for an internal combustion engine according to claim 2, wherein the first inlet is in communication with the chain housing chamber, and the second inlet is in communication with the crank chamber.

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