JP2018084143A - Oil separator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an oil separator capable of inhibiting an increase in the size of a cylinder head cover in a vertical direction in a configuration where an oil separator chamber is provided in the cylinder head cover.SOLUTION: An oil separator 30 includes: an oil separator camber 40 provided in a cylinder head cover 20 of an internal combustion engine 100 and including an introduction passage 42 and a discharge passage 44; a penetration type oil separation member 50 disposed at a position where the introduction passage 42 and the discharge passage 44 are overlapped with each other vertically so as to cause the blow-by gas to penetrate from the upper side to the lower side; a first member 60 joined to an upper surface side of the cylinder head cover 20 and forming the introduction passage 42 together with an upper surface portion 21 of the cylinder head cover 20; and a second member 70 joined to a lower surface side of the cylinder head cover 20 and forming the discharge passage 44 together with a lower surface portion 22 of the cylinder head cover 20.SELECTED DRAWING: Figure 2

Description

  The present invention relates to an oil separator.

  Conventionally, an oil separator provided with an oil separator chamber is known (see, for example, Patent Document 1).

  Patent Document 1 discloses an oil mist separator (oil separator) including a blow-by gas channel (oil separator chamber) and a transmission type filter that is disposed in the blow-by gas channel and separates oil from oil mist in the blow-by gas. ) Is disclosed. The oil mist separator is provided on the cylinder head cover. In this oil mist separator, the blow-by gas flow path is provided independently of the cylinder head cover.

Japanese Patent No. 5223728

  In the oil mist separator described in Patent Document 1, since the blow-by gas flow path is provided independently of the cylinder head cover, there is a disadvantage that the oil separator is increased in size. Therefore, a blow-by gas flow path may be provided integrally with the cylinder head cover. However, in this case, there is a problem that the cylinder head cover is enlarged in the vertical direction by the amount of the blow-by gas passage (oil separator chamber).

  The present invention has been made to solve the above-described problems, and one object of the present invention is to increase the size of the cylinder head cover in the vertical direction in a configuration in which an oil separator chamber is provided in the cylinder head cover. It is providing the oil separator which can suppress this.

  In order to achieve the above object, an oil separator according to one aspect of the present invention is provided in a cylinder head cover of an internal combustion engine, and has an introduction passage having an introduction port through which blowby gas is introduced, and blowby gas from which blowby gas is discharged. An oil separator chamber including a discharge passage, and a position where the introduction passage and the discharge passage overlap in the vertical direction so that the blow-by gas permeates downward from above, and the oil is discharged from the blow-by gas. A transmissive oil separating member to be separated, a first member joined to the upper surface side of the cylinder head cover and forming an introduction passage with the upper surface portion of the cylinder head cover, and joined to the lower surface side of the cylinder head cover, together with the lower surface portion of the cylinder head cover A second member forming a discharge passage.

  In the oil separator according to one aspect of the present invention, as described above, the first member which is joined to the upper surface side of the cylinder head cover and forms the introduction passage together with the upper surface portion of the cylinder head cover, and the lower surface side of the cylinder head cover are joined. A second member that forms a discharge passage together with a lower surface portion of the cylinder head cover. As a result, the cylinder head cover itself can be prevented from increasing in size upward by the amount of the first member to be joined to the upper surface side of the cylinder head cover. Further, the cylinder head cover itself can be prevented from being enlarged in the downward direction by the amount of the second member to be joined to the lower surface side of the cylinder head cover. As a result, in the configuration in which the oil separator chamber is provided in the cylinder head cover, the cylinder head cover can be prevented from being enlarged in the vertical direction. Further, by disposing the oil separating member so that the blow-by gas permeates from above to below, the oil separating member can be disposed horizontally long (in a state that is long in the horizontal direction). As a result, the oil separator chamber can be made smaller in the vertical direction as compared with the case where the oil separation member is disposed vertically long (a state that is long in the vertical direction). Accordingly, in the configuration in which the oil separator chamber is provided in the cylinder head cover, it is possible to further suppress the cylinder head cover from being enlarged in the vertical direction.

  In the oil separator according to the above aspect, the second member preferably has an oil discharge port for discharging the oil separated from the blow-by gas by the oil separation member.

  If comprised in this way, since it is not necessary to provide an oil discharge port in a cylinder head cover, the structure of a cylinder head cover can be simplified correspondingly.

  In this case, the oil discharge port is preferably arranged at the lowermost part of the second member.

  If comprised in this way, since the oil isolate | separated from blow-by gas by the oil separation member can be collected in an oil discharge port by gravity, oil can be discharged | emitted effectively from an oil discharge port. As a result, it is possible to suppress the occurrence of an oil pool in the discharge passage, and therefore, it is possible to suppress the oil from re-scattering in the blow-by gas due to the oil pool.

  In the oil separator according to the above aspect, the flow passage cross-sectional area of the introduction passage is preferably larger than the flow passage cross-sectional area of the discharge passage.

  If comprised in this way, the flow velocity of the blow-by gas in an introduction channel | path can be made small compared with the flow velocity of the blow-by gas in a discharge channel. As a result, the liquid oil having a large particle size contained in the blow-by gas can be easily separated from the blow-by gas in the introduction passage, so that the liquid oil having a large particle size is prevented from being conveyed to the oil separation member. Can do. As a result, the oil separation member can be hardly clogged.

  In this case, preferably, the first member is recessed on the upper side of the cylinder head cover and has a recess that constitutes the introduction passage.

  If comprised in this way, since the flow-path cross-sectional area of an introduction channel | path can be ensured by the 1st member which has a recessed part dented upwards, it will suppress that the cylinder head cover enlarges that much in the up-down direction. Can do.

  In the oil separator according to the above aspect, the oil separation member is preferably held between the upper surface portion of the cylinder head cover and the first member, or between the lower surface portion of the cylinder head cover and the second member.

  With this configuration, the oil separation member is horizontally long (long in the horizontal direction) in the oil separator chamber between the upper surface portion of the cylinder head cover and the first member or between the lower surface portion of the cylinder head cover and the second member. Can be easily arranged.

  In the oil separator according to the above aspect, the following configuration is also conceivable.

(Additional item 1)
For example, in the oil separator according to the above aspect, the oil separation member preferably includes a plurality of wire mesh members stacked along the flow direction of blow-by gas.

1 is an exploded perspective view showing a schematic configuration of an internal combustion engine equipped with an oil separator according to an embodiment of the present invention. It is the disassembled perspective view which showed the oil separator by one Embodiment. It is the perspective view which showed the oil separator by one Embodiment. FIG. 4 is a perspective sectional view taken along line 300-300 in FIG. 3. It is sectional drawing along the 300-300 line of FIG. It is a top view of a cylinder head cover in the state where the 1st member by one embodiment is not joined. It is a bottom view of a cylinder head cover in the state where the 2nd member by one embodiment is not joined. It is sectional drawing (B) along the 400-400 line | wire of the top view (A) and FIG. 8 (A) which showed the oil separation member by one Embodiment.

  DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments embodying the present invention will be described below with reference to the drawings. In the following, the direction in which the crankshaft 11 extends is defined as the X direction, and the direction orthogonal to the X direction in the horizontal plane is defined as the Y direction. The vertical direction perpendicular to the horizontal plane is taken as the Z direction. The vertical direction is a vertical direction in a state where the internal combustion engine 100 is mounted on a vehicle (not shown).

(Configuration of internal combustion engine and its surroundings)
With reference to FIGS. 1-8, the oil separator 30 mounted in the internal combustion engine 100 by one Embodiment of this invention is demonstrated.

  An oil separator 30 according to an embodiment of the present invention is provided in an in-line three-cylinder internal combustion engine 100 as shown in FIG. The internal combustion engine 100 includes an internal combustion engine body 10 that includes a cylinder head 1, a cylinder block 2, and a crankcase 3. The cylinder head 1, the cylinder block 2 and the crankcase 3 are all made of an aluminum alloy.

  A cylinder head cover 20, an intake manifold (not shown), and an exhaust manifold (not shown) are attached to the internal combustion engine body 10. The cylinder head cover 20 is disposed so as to cover the cylinder head 1 of the internal combustion engine body 10 from above.

  A crank chamber 4 is formed in the internal combustion engine body 10 by the cylinder block 2 and the crankcase 3. The cylinder head cover 20, the cylinder head 1, and the cylinder block 2 are fastened by a plurality of fastening members 10a made of bolts.

  In the crank chamber 4, a crankshaft 11 is disposed so as to be rotatable around a rotation axis A extending in the X direction. The crankshaft 11 has the rotation axis A aligned with the height position (Z direction) of the mating surface between the cylinder block 2 and the crankcase 3. The crankcase 3 is provided with an oil pan 5 for storing lubricating oil. The oil is pumped up from the oil pan 5 by an oil pump (not shown) and supplied around a movable member such as a piston (not shown) or the crankshaft 11 and then dripped from the movable member by its own weight. Return to.

  In the crankcase 3 (crank chamber 4) in which the oil pan 5 is disposed, an unburned mixture containing hydrocarbons that have leaked into the crank chamber 4 through the gap between the inner wall surface of the cylinder 2a and the piston and combustion gas during combustion. There is a blowby gas that is The internal combustion engine 100 is configured so that blow-by gas is recirculated through the intake manifold. The recirculated blow-by gas is a liquid oil having a large particle size (100 μm or more) scattered in the crank chamber 4, a mist-like oil having a small particle size (2 μm or less) smaller than the liquid oil, Contains moisture. Therefore, the internal combustion engine 100 is equipped with an oil separator 30 having a function of gas-liquid separation of blow-by gas.

  The blow-by gas is introduced from the crank chamber 4 into the oil separator 30 through the blow-by gas passage portion 3a of the crankcase 3, the blow-by gas passage portion 2b of the cylinder block 2, and the blow-by gas passage portion 1a of the cylinder head 1. The In the oil separator 30, oil is separated from blow-by gas. The separated oil is supplied from the oil separator 30 through the oil passage portion 1b of the cylinder head 1, the oil passage portion 2c of the cylinder block 2, and the oil passage portion 3b of the crankcase 3 to the crank chamber 4 (oil pan). Return to 5). The blow-by gas from which the oil has been separated is supplied from the oil separator 30 to the intake manifold via a connection hose (not shown). In FIG. 1, the flow of blow-by gas and oil is indicated by a thick two-dot chain line. Hereinafter, the configuration of the oil separator 30 will be described in detail.

(Configuration of oil separator)
2 to 8, the oil separator 30 is disposed in the oil separator chamber 40 provided in the cylinder head cover 20 of the internal combustion engine 100 and the oil separator chamber 40, and collects and separates oil from blow-by gas. A transmissive oil separation member 50.

  The oil separator chamber 40 includes an introduction passage 42 having a blow-by gas introduction port 41 into which blow-by gas is introduced, and a discharge passage 44 having a blow-by gas discharge port 43 through which blow-by gas is discharged. The introduction passage 42 is a blow-by gas passage on the upstream side of the oil separation member 50, and is a blow-by gas passage until the blow-by gas introduced from the blow-by gas introduction port 41 is introduced into the oil separation member 50. The discharge passage 44 is a blow-by gas passage downstream of the oil separation member 50 and is a blow-by gas passage until the blow-by gas discharged from the oil separation member 50 is discharged from the blow-by gas discharge port 43. .

  The blow-by gas introduction port 41 and the blow-by gas discharge port 43 are both provided in the cylinder head cover 20 as through holes that penetrate the cylinder head cover 20 in the vertical direction (Z direction). Connected to the blow-by gas discharge port 43 is a PCV (Positive Crankcase Ventilation) valve 45 that adjusts the amount of blow-by gas discharged from the blow-by gas discharge port 43 to the intake manifold. In the oil separator 30, the blow-by gas passes through the blow-by gas introduction port 41, the introduction passage 42, the oil separation member 50, the discharge passage 44, the blow-by gas discharge port 43, and the PCV valve 45 in this order.

  Here, in the present embodiment, the oil separator 30 is joined to the upper surface side (upper surface portion 21) of the cylinder head cover 20, and the first member 60 that forms the introduction passage 42 together with the upper surface portion 21 of the cylinder head cover 20, and the cylinder head cover. And a second member 70 which is joined to the lower surface side (lower surface portion 22) of the cylinder 20 and forms the introduction passage 42 together with the lower surface portion 22 (see FIG. 4) of the cylinder head cover 20. That is, the oil separator 30 is configured to be defined by the upper surface portion 21 of the cylinder head cover 20 and the first member 60, thereby forming the introduction passage 42. Further, the oil separator 30 is configured to be defined by the lower surface portion 22 of the cylinder head cover 20 and the second member 70 so that a discharge passage 44 is formed. The cylinder head cover 20, the first member 60, and the second member 70 are all made of resin.

  The upper surface portion 21 of the cylinder head cover 20 is recessed downward (Z2 direction) and has a recessed portion 21a that constitutes a lower portion of the introduction passage 42. The recess 21a has one corner 21b that changes the flow direction of blow-by gas, and is formed in an L shape in plan view (viewed from the Z direction). Further, the upper surface portion 21 of the cylinder head cover 20 has a joint surface 21c disposed so as to surround the recess 21a along the outer edge portion of the recess 21a.

  The first member 60 is recessed from the upper surface portion 21 of the cylinder head cover 20 while being joined to the upper surface side (upper surface portion 21) of the cylinder head cover 20, and has a recess 61 that constitutes the upper portion of the introduction passage 42. doing. The recess 61 has one corner 61a that changes the flow direction of blow-by gas so as to correspond to the recess 21a of the cylinder head cover 20, and is formed in an L shape in plan view. The first member 60 has a flange portion 62 arranged so as to surround the recess 61 along the outer edge portion of the recess 61.

  In the oil separator 30, the first member 60 is configured to be joined to the upper surface portion 21 of the cylinder head cover 20 by vibration welding the flange portion 62 to the joining surface 21 c of the upper surface portion 21 of the cylinder head cover 20. ing. As a result, the recess 21 a of the cylinder head cover 20 and the recess 61 of the first member 60 form an L-shaped introduction passage 42 in plan view. In the corner portion of the L-shaped introduction passage 42, the blow-by gas is allowed to advance by inertia and collide with the side wall, whereby oil contained in the blow-by gas can be separated.

  As shown in FIGS. 4, 5, and 7, the lower surface portion 22 of the cylinder head cover 20 is recessed upward (in the Z <b> 1 direction) and has a recess 22 a that constitutes the upper portion of the discharge passage 44. The recess 22a has two corners 22b that change the flow direction of the blow-by gas, and is formed in a U shape in plan view (viewed from the Z direction). Further, the lower surface portion 22 of the cylinder head cover 20 has a joint surface 22c arranged so as to surround the recess 22a along the outer edge portion of the recess 22a.

  As shown in FIG. 2, the second member 70 is joined to the lower surface side (lower surface portion 22) of the cylinder head cover 20 and is recessed downward from the lower surface portion 22 of the cylinder head cover 20, and the lower side of the discharge passage 44. It has the recessed part 71 which comprises a part. The recess 71 has two corners 71a that change the flow direction of blow-by gas so as to correspond to the recess 22a of the cylinder head cover 20, and is formed in a U shape in plan view. Further, the second member 70 has a flange portion 72 disposed so as to surround the recess 71 along the outer edge portion of the recess 71.

  In the oil separator 30, the second member 70 is configured to be joined to the lower surface portion 22 of the cylinder head cover 20 by vibration-welding the flange portion 72 to the joining surface 22 c of the lower surface portion 22 of the cylinder head cover 20. ing. As a result, the U-shaped discharge passage 44 is formed in plan view by the recess 22 a of the cylinder head cover 20 and the recess 71 of the second member 70. In the corner portion of the U-shaped discharge passage 44, similarly to the introduction passage 42, it is possible to separate the oil contained in the blow-by gas by causing the blow-by gas to advance by inertia and collide with the side wall.

  In the present embodiment, the second member 70 has an oil discharge port 73 for discharging the oil separated from the blow-by gas by the oil separation member 50. The oil discharge port 73 is the lowermost part of the second member 70 and is disposed in the vicinity of the corner portion 71a on the Y1 direction side. For this reason, the oil discharge port 73 is located below the oil separation member 50. Further, the oil discharge port 73 is connected to the oil passage portion 1 b of the cylinder head 1. In the present embodiment, the flow passage cross-sectional area of the introduction passage 42 is larger than the flow passage cross-sectional area of the discharge passage 44. For this reason, the concave depth of the concave portion 61 of the first member 60 constituting the introduction passage 42 is larger than the concave depth of the concave portion 71 of the second member 70.

  As shown in FIGS. 2 and 4 to 7, the oil separating member 50 has the transmission surface 50 a in the horizontal direction (X direction and Y direction) at a position where the introduction passage 42 and the discharge passage 44 overlap in the vertical direction. It is arrange | positioned so that it may become the direction along. The oil separation member 50 is disposed above the bottom surface of the discharge passage 44. Thereby, the oil separation member 50 is arrange | positioned so that blow-by gas permeate | transmits below (Z2 direction) from upper direction (Z1 direction).

  As shown in FIG. 8, the oil separation member 50 includes a plurality of wire mesh members 50b stacked along the flow direction of blow-by gas, and is a rectangular plate-like member. The oil separation member 50 is configured such that blow-by gas passes through the mesh of the metal mesh member 50b. The oil separation member 50 is configured to adhere oil contained in the blow-by gas to the frame portion of the wire mesh member 50b when the blow-by gas passes through the mesh of the wire mesh member 50b.

  The oil separation member 50 is held by a frame-shaped holding member 80 made of resin. The holding member 80 is configured to hold the outer edge portion of the oil separating member 50 in a circumferential shape. The wire mesh member 50b of the oil separating member 50 is exposed to the outside from the opening 81 of the frame-shaped holding member 80. Further, the cylinder head cover 20 has an opening 23 penetrating in the vertical direction at a position where the introduction passage 42 and the discharge passage 44 overlap in the vertical direction. The holding member 80 is configured to be joined to the lower surface portion 22 of the cylinder head cover 20 by vibration welding at a position corresponding to the opening 23. Thus, the oil separation member 50 is attached to the lower surface portion 22 of the cylinder head cover 20 from below (Z2 direction) via the holding member 80. In the present embodiment, the oil separation member 50 is attached to the lower surface portion 22 of the cylinder head cover 20 before the second member 70 is joined to the cylinder head cover 20. In the present embodiment, the oil separation member 50 is held by the cylinder head cover 20 between the lower surface portion 22 of the cylinder head cover 20 and the second member 70.

(Separation of oil by oil separator)
Next, separation of oil from blow-by gas by the oil separator 30 of the present embodiment will be described with reference to FIG.

  As shown in FIG. 2, when blow-by gas is introduced into the oil separator chamber 40 from the blow-by gas introduction port 41, the introduced blow-by gas is guided to the oil separation member 50 along the L-shaped introduction passage 42. In the introduction passage 42, since the cross-sectional area of the flow path is relatively large, liquid oil having a large particle size is separated by its own weight. The separated liquid oil is discharged from the blow-by gas inlet 41 through the introduction passage 42 and returns to the oil pan 5 (see FIG. 1).

  The blow-by gas guided to the oil separation member 50 passes through the oil separation member 50 from the upper direction to the lower direction. As a result, mist-like oil having a small particle size (2 μm or less) contained in the blow-by gas is collected and separated by the oil separation member 50. The oil collected in the oil separation member 50 is dropped into the discharge passage 44 by its own weight. Thereafter, the oil dripped into the discharge passage 44 is discharged through the discharge passage 44 through the oil discharge port 73 disposed at the lowermost portion of the discharge passage 44 and returns to the oil pan 5.

  The blow-by gas from which the oil has been separated is discharged from the blow-by gas discharge port 43 and is supplied to the intake manifold via the PCV valve 45.

(Effect of this embodiment)
In the present embodiment, the following effects can be obtained.

  In the present embodiment, as described above, the first member 60 which is joined to the upper surface side of the cylinder head cover 20 and forms the introduction passage 42 together with the upper surface portion 21 of the cylinder head cover 20, and the lower surface side of the cylinder head cover 20 are joined. And a second member 70 that forms the discharge passage 44 together with the lower surface portion 22 of the cylinder head cover 20. As a result, the cylinder head cover 20 itself can be prevented from increasing in size upward by the amount of the first member 60 to be joined to the upper surface side of the cylinder head cover 20. Further, the cylinder head cover 20 itself can be prevented from being enlarged in the downward direction as much as the second member 70 joined to the lower surface side of the cylinder head cover 20 is provided. As a result, in the configuration in which the oil separator chamber 40 is provided in the cylinder head cover 20, the cylinder head cover 20 can be prevented from being enlarged in the vertical direction. Further, by disposing the oil separating member 50 so that the blow-by gas permeates from above to below, the oil separating member 50 can be disposed in a horizontally long state (long state in the horizontal direction). As a result, the oil separator chamber 40 can be made smaller in the vertical direction as compared with the case where the oil separation member 50 is arranged in a vertically long state (long state in the vertical direction). Accordingly, in the configuration in which the oil separator chamber is provided in the cylinder head cover 20, it is possible to further suppress the cylinder head cover 20 from being enlarged in the vertical direction.

  In the present embodiment, as described above, the second member 70 has the oil discharge port 73 that discharges the oil separated from the blow-by gas by the oil separation member 50. Thereby, since it is not necessary to provide the oil discharge port 73 in the cylinder head cover 20, the structure of the cylinder head cover 20 can be simplified correspondingly.

  In the present embodiment, the oil discharge port 73 is disposed at the lowermost portion of the second member 70 as described above. Thereby, the oil separated from the blow-by gas by the oil separation member 50 can be collected in the oil discharge port 73 by gravity, so that the oil can be effectively discharged from the oil discharge port 73. As a result, it is possible to suppress the occurrence of an oil pool in the discharge passage 44, and therefore, it is possible to suppress the oil from re-scattering in the blow-by gas due to the oil pool.

  In the present embodiment, as described above, the flow passage cross-sectional area of the introduction passage 42 is made larger than the flow passage cross-sectional area of the discharge passage 44. Thereby, the flow rate of blow-by gas in the introduction passage 42 can be made smaller than the flow rate of blow-by gas in the discharge passage 44. As a result, since the liquid oil having a large particle size contained in the blow-by gas can be easily separated from the blow-by gas in the introduction passage 42, the large-particle liquid oil is prevented from being conveyed to the oil separation member 50. can do. As a result, the oil separation member 50 can be made less likely to be clogged.

  In the present embodiment, as described above, the first member 60 is recessed on the upper side of the cylinder head cover 20 and has the recess 61 that constitutes the introduction passage 42 while being recessed upward. Accordingly, the flow passage cross-sectional area of the introduction passage 42 can be secured by the first member 60 having the concave portion 61 that is recessed upward, and accordingly, the cylinder head cover 20 is prevented from being enlarged in the vertical direction. Can do.

  In the present embodiment, as described above, the oil separation member 50 is held between the lower surface portion 22 of the cylinder head cover 20 and the second member 70. Thereby, between the lower surface part 22 of the cylinder head cover 20, and the 2nd member 70, the oil-separation member 50 can be easily arrange | positioned in the oil-separator chamber horizontally long (a state long in a horizontal direction).

  In the present embodiment, as described above, the oil separation member 50 includes a plurality of wire mesh members 50b stacked along the flow direction of blow-by gas. Thereby, blow-by gas can be permeate | transmitted from upper direction to the downward direction via the mesh | network of the metal-mesh member 50b, separating oil by making oil of blow-by gas adhere to the laminated metal-mesh member 50b.

[Modification]
The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is shown not by the above description of the embodiment but by the scope of claims for patent, and further includes all modifications (modifications) within the meaning and scope equivalent to the scope of claims for patent.

  For example, in the said embodiment, although the 1st member and the 2nd member showed the example joined to a cylinder head cover by vibration welding, this invention is not limited to this. In the present invention, the first member and the second member may be joined to the cylinder head cover by a method other than vibration welding. For example, the first member and the second member may be joined to the cylinder head cover by a fastening member such as a screw.

  Moreover, in the said embodiment, although the flow-path cross-sectional area of the introduction channel showed an example larger than the flow-path cross-sectional area of a discharge channel, this invention is not limited to this. For example, the flow passage cross-sectional area of the introduction passage and the flow passage cross-sectional area of the discharge passage may be substantially the same, or the flow passage cross-sectional area of the introduction passage may be smaller than the flow passage cross-sectional area of the discharge passage.

  Moreover, in the said embodiment, although the recessed depth of the recessed part of the 1st member showed an example larger than the recessed depth of the recessed part of the 2nd member, this invention is not limited to this. For example, the recess depth of the recess of the first member may be substantially the same as the recess depth of the recess of the second member, and the recess depth of the recess of the first member is smaller than the recess depth of the recess of the second member. May be.

  Moreover, although the oil separation member was attached to the lower surface part of a cylinder head cover from the downward direction in the said embodiment, this invention is not limited to this. For example, the oil separation member may be attached to the upper surface portion of the cylinder head cover from above. In this case, the oil separation member is held by the cylinder head cover between the upper surface portion of the cylinder head cover and the first member.

  Moreover, although the example which provides the oil separation member containing a metal-mesh member as a member for oil separation was shown in the said embodiment, this invention is not limited to this. In the present invention, as long as it is a transmission type oil separation member, an oil separation member including other than the metal mesh member may be provided as an oil separation member. For example, an oil separation member including a nonwoven fabric may be provided as the oil separation member.

  In the above embodiment, as an example of the orientation of the transmission surface along the horizontal direction, an example in which the oil separation member is arranged so that the transmission surface is oriented parallel to the horizontal direction has been described. It is not limited to this. In the present invention, the oil separation member may be arranged so that the permeation surface is slightly inclined with respect to the horizontal direction if the blow-by gas permeates from above to below.

DESCRIPTION OF SYMBOLS 20 Cylinder head cover 30 Oil separator 40 Oil separator chamber 41 Blow-by gas introduction port 42 Introduction passage 43 Blow-by gas discharge port 44 Discharge passage 50 Oil separation member 50b Metal mesh member 60 First member 61 Recess 70 Second member 73 Oil discharge port 100 Internal combustion engine

Claims (6)

An oil separator chamber that is provided in a cylinder head cover of an internal combustion engine and includes an introduction passage having a blow-by gas introduction port into which blow-by gas is introduced; and a discharge passage having a blow-by gas discharge port through which the blow-by gas is discharged;
A transmission-type oil separation member that is arranged so that the blow-by gas permeates downward from above at a position where the introduction passage and the discharge passage overlap in the vertical direction; and
A first member joined to the upper surface side of the cylinder head cover and forming the introduction passage together with an upper surface portion of the cylinder head cover;
An oil separator, comprising: a second member joined to a lower surface side of the cylinder head cover and forming the discharge passage together with a lower surface portion of the cylinder head cover.   2. The oil separator according to claim 1, wherein the second member has an oil discharge port that discharges the oil separated from the blow-by gas by the oil separation member.   The oil separator according to claim 2, wherein the oil discharge port is disposed at a lowermost portion of the second member.   The oil separator according to any one of claims 1 to 3, wherein a flow passage cross-sectional area of the introduction passage is larger than a flow passage cross-sectional area of the discharge passage.   5. The oil separator according to claim 4, wherein the first member is recessed upward while being recessed on the upper surface side of the cylinder head cover and constituting the introduction passage. 6.   The oil separation member is held between the upper surface portion of the cylinder head cover and the first member, or between the lower surface portion of the cylinder head cover and the second member. The oil separator according to claim 1.

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