JP2017115848A - Oil separator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an oil separator which enables separative power of an oil contained in a blow-by gas to be fully achieved without causing uneven distribution of blow-by gas flow therein.SOLUTION: An oil separator 50 includes: a first portion 60 provided at a cylinder block 2; and a second portion 70 which is attached to the first portion 60 from a lateral side of the cylinder block 2 to form a first chamber 51 and a second chamber 52, which are partitioned, with the first portion 60. The first portion 60 includes: a blow-by gas suction passage 61 provided in the first passage 51; and a drain passage 62 provided at the second chamber 52 and configured to discharge an oil. The second portion 70 includes a collection member 65 disposed between the first chamber 51 and the second chamber 52 and a collision plate 72 with which the oil is collided. An oil inflow port 62a of the drain passage 62 is positioned above a bottom dead point P of the piston 12, and an oil discharge port 62b is positioned below a lower end surface 2c of the cylinder block 2.SELECTED DRAWING: Figure 3

Description

  The present invention relates to an oil separator.

  Conventionally, an oil separator that gas-liquid separates oil from blow-by gas is known (see, for example, Patent Document 1).

  Patent Document 1 discloses an oil mist separator (oil separator) that gas-liquid separates oil contained in blow-by gas of an internal combustion engine. In the oil mist separator described in Patent Document 1, a concave portion is formed on the outer surface of the cylinder block, an oil separation portion is inserted into the concave portion, and the concave portion is sealed from the outside by a cover member. The internal space of the recess and the crank chamber communicate with each other via two blow-by gas suction passages. The blow-by gas sucked through one blow-by gas suction passage directly collides with the inner wall of the recess and the oil is separated by a labyrinth method (inertial collision method). The blow-by gas sucked through is introduced into the oil separation unit, and the oil is separated by a cyclone method (centrifugal separation method). In general, the cyclone method is superior in oil separation capability to the labyrinth method, but the flow path resistance is large. The oil separated in each of the internal space of the recess and the oil separation part is returned to the crank chamber via the discharge passage. Further, the blow-by gas staying in the internal space of the recess is configured to be recirculated from the discharge passage to the intake passage of the internal combustion engine via the oil separation portion.

JP 2014-84730 A

  However, in the oil mist separator described in Patent Document 1, the crank chamber and the internal space of the recess sealed by the cover member are communicated with each other by two blow-by gas suction passages. While a large amount of blow-by gas is sucked into the interior space of the small concave portion, the blow-by gas is hardly sucked into the oil separation portion having a relatively large flow path resistance, and the flow rate is reduced between the two blow-by gas suction passages. It is thought that a balance will arise. For this reason, blow-by gas tends to be biased in the state of gas-liquid separation by the labyrinth method in the inner space of the recess where the oil separation ability is relatively small, and the cyclone type oil separation part having excellent separation ability is provided. However, there is a problem that sufficient gas-liquid separation cannot be achieved, and the oil separation ability as the whole oil separator cannot be fully exhibited.

  The present invention has been made to solve the above-described problems, and one object of the present invention is to separate oil contained in blow-by gas without causing uneven distribution of the blow-by gas flow inside. It is an object to provide an oil separator capable of sufficiently exhibiting the above.

  In order to achieve the above object, an oil separator according to one aspect of the present invention is provided in a cylinder block of an internal combustion engine, and includes a first oil separator portion having one portion constituting a first chamber and a second chamber, A first chamber and a second chamber that are partitioned together with the first oil separator portion by having the other portion constituting the one chamber and the second chamber and being attached to the first oil separator portion from the side of the cylinder block. A first oil separator portion that is provided on the first chamber side and an oil that is provided on the second chamber side and separated from the blowby gas. The second oil separator is disposed between the first chamber and the second chamber and is included in the blow-by gas. A collecting member that collects the mist, and a collision plate that is disposed in the path on the second chamber side after passing through the collecting member and collides with the oil collected by the collecting member; The oil inlet opening to the two chambers is located above the piston bottom dead center in the internal combustion engine, and the oil discharge port opened inside the internal combustion engine in the discharge passage is located below the lower end surface of the cylinder block. .

  In the oil separator according to one aspect of the present invention, as described above, the first oil separator portion includes a blow-by gas suction passage provided on the first chamber side, and the second oil separator portion includes the first chamber and the first chamber. A collecting member that is disposed between the second chamber and collects oil mist contained in the blow-by gas, and is disposed in a path on the second chamber side after passing through the collecting member and is collected by the collecting member. And a collision plate for colliding the collected oil. Thereby, in the oil separator, the blow-by gas generated in the internal combustion engine (lower cylinder block) is introduced into the first chamber through the suction passage, and the entire amount of the blow-by gas introduced into the first chamber is reduced. Then, it is possible to create a one-way blow-by gas flow that passes through the collection member and is circulated through the second chamber. At this time, while collecting the oil mist by the upstream collecting member, the collected oil collides with the collision plate on the downstream side to capture the liquid oil, and the oil provided on the second chamber side The exhaust passage can be returned to the internal combustion engine (crank chamber). That is, the oil can be separated from the entire amount of the blow-by gas introduced without causing the uneven distribution of the blow-by gas flow in the oil separator, so that the oil separation ability as a whole of the oil separator can be sufficiently exhibited. .

  In the oil separator according to the first aspect, the first oil separator portion includes a discharge passage for discharging the oil separated from the blow-by gas, and the oil inlet opening to the second chamber of the discharge passage is provided below the piston in the internal combustion engine. An oil discharge port that is located above the dead point and opens inside the internal combustion engine in the discharge passage is positioned below the lower end surface of the cylinder block. As a result, even when an oil separator is provided in the cylinder block of the internal combustion engine, a sufficient level difference in the discharge passage from the oil inlet to the oil outlet can be secured. Therefore, since the oil head (oil liquid column) can be reliably formed in the oil discharge passage, the blow-by gas is surely circulated through the suction passage of the blow-by gas that has a smaller pressure loss than the oil head of the oil. Can do. Also by this, the blow-by gas from the internal combustion engine can be easily circulated in the order of the first chamber, the collecting member, and the second chamber.

  In the oil separator according to the above aspect, the first oil separator portion is preferably provided integrally with the cylinder block, and the second oil separator portion is constituted by a cover member that covers the first oil separator portion.

  If comprised in this way, the oil separator which has a 1st chamber and a 2nd chamber can be provided in an internal combustion engine only by attaching a cover member to a cylinder block. That is, unlike the case of assembling an oil separation member as a separate part in the pre-process for attaching the cover member, the oil separator manufacturing process can be simplified and the internal structure of the oil separator can be simplified.

  In the oil separator according to the above aspect, preferably, the second oil separator portion further includes a control valve disposed on the second chamber side and controlling the flow of blow-by gas.

  If comprised in this way, since the function which controls (adjusts) the flow of blow-by gas can be given to the 2nd oil separator part, the control valve of the 2nd oil separator part and an internal combustion engine (intake system) are connected. By simply doing so, it is possible to easily construct a reflux path for blow-by gas.

  In the oil separator according to the above aspect, preferably, in the oil discharge passage, the cross-sectional area of the oil discharge port provided in the cylinder block is smaller than the cross-sectional area of the oil inflow port provided in the cylinder block.

  With this configuration, the oil separated from the blow-by gas can smoothly flow into the oil inlet, and the oil discharge passage has a smaller sectional area than the oil inlet in the oil discharge passage. Therefore, the oil can be easily filled in the discharge passage. In other words, since the oil head (oil liquid column) can be quickly formed in the oil discharge passage, the blow-by gas suction passage that causes rapid oil head formation and lower pressure loss than the oil head in the oil discharge passage. The blowby gas can be circulated quickly.

  In this case, preferably, the discharge passage has a backflow prevention structure for preventing the oil flowing down the discharge passage from flowing back to the oil inlet side.

  With this configuration, it is possible to prevent the oil filled in the discharge passage from being returned to the second chamber and taken away from the oil separator to the intake system of the internal combustion engine. Also, since no back flow of oil occurs in the discharge passage, it is possible to reliably prevent the blow-by gas from being sucked into the second chamber through the oil discharge passage. Therefore, blow-by gas can be reliably sucked into the first chamber through the suction passage, so that the oil separation ability of the oil separator can be reliably maintained.

  In the oil separator according to the above aspect, the collection member is preferably made of a wire mesh in which collection holes for collecting oil mist are arranged in a mesh shape.

  If comprised in this way, while being able to collect oil mist with the collection member which consists of metal nets with high efficiency, the oil which liquefied and collected on the collection member (metal mesh) is collected quickly. ) Can be discharged. Further, compared to the case where a filter made of filter paper or the like is provided, the wire mesh itself is excellent in oil discharge performance, so that the wire mesh can be prevented from being clogged and the passage resistance (pressure loss) can be kept low. Thereby, the flow volume of the blow-by gas which passes the collection member which consists of a metal mesh can be ensured appropriately. As a result, by quickly discharging the oil collected from the blow-by gas, the flow rate of the blow-by gas can be appropriately secured and the ventilation performance of the blow-by gas can be maintained.

  In this case, preferably, the collection member is arranged inside the second oil separator portion so that the longitudinal direction of the collection holes arranged in a mesh shape matches the gravity direction in which the collected oil flows down. Has been.

  If comprised in this way, the oil collected by the collection member which consists of metal nets will flow down quickly and reliably along the longitudinal direction of a collection hole with the dead weight of oil, and will be discharged from a collection member (metal mesh) can do. Moreover, since clogging of the collection hole is suppressed, further oil can be collected, and the oil separation ability of the collection member can be maintained high.

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

(Additional item 1)
That is, in the oil separator according to the above aspect, the height difference from the oil inlet to the oil outlet in the discharge passage provided in the cylinder block is set to 100 mm or more.

(Appendix 2)
Further, in the oil separator in which the collection member is made of a wire mesh, the collection member is configured by overlapping a plurality of wire mesh members along the flow direction of the blow-by gas.

(Additional Item 3)
Further, in the oil separator in which the plurality of wire mesh members are overlapped to form a collection member, the collection member is formed by bending a plurality of elongated wire mesh members back and forth so that the plurality of wire mesh members folded back to each other. It is comprised so that a part may be piled up.

(Appendix 4)
Further, in the oil separator according to the above one aspect, the suction passage provided on the first chamber side is bent between the blow-by gas suction port and the introduction port to the first chamber, so that the internal combustion engine A liquid oil separator that collects oil having a large particle size contained in blow-by gas, and the collecting member arranged to partition the first chamber and the second chamber is a blow-by after passing through the liquid oil separator. It is an oil mist separation unit that collects oil mist having a small particle size contained in gas.

It is the perspective view which showed the schematic structure of the engine main body by one Embodiment of this invention. It is a fragmentary sectional view at the time of seeing the engine body by one embodiment of the present invention from the side. It is the perspective view which showed the structure of the oil separator by one Embodiment of this invention. It is the figure which showed the structure at the time of seeing the engine main body by one Embodiment of this invention from the downward direction. It is sectional drawing which showed the internal structure of the oil separator by one Embodiment of this invention. It is sectional drawing which showed the internal structure of the oil separator by one Embodiment of this invention. It is the figure which showed the internal structure of the oil separator by one Embodiment of this invention. It is the figure which showed the detailed structure of the collection member by one Embodiment of this invention. It is sectional drawing which showed the internal structure of the oil separator by the 1st modification of this invention. It is sectional drawing which showed the internal structure of the oil separator by the 2nd modification of this invention. It is the perspective view which showed the detailed structure of the collection member by the 3rd modification of this invention. It is sectional drawing which showed the detailed structure of the collection member by the 3rd modification of this invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[Embodiment]
With reference to FIGS. 1-8, the oil separator 50 mounted in the engine 100 by one Embodiment of this invention is demonstrated.

  As shown in FIG. 1, an oil separator 50 according to an embodiment of the present invention is provided in a naturally aspirated and in-line three-cylinder engine 100 (an example of an internal combustion engine). As shown in FIGS. 1 and 2, the engine 100 includes an engine body 10 including an aluminum alloy cylinder head 1 (see FIG. 2), a cylinder block 2, and a crankcase 3. A head cover (not shown), a chain cover 20 (see FIG. 2), an intake manifold 30 (see FIG. 2), and an exhaust manifold (not shown) are attached to the engine body 10. The engine 100 is installed in an engine room (not shown) with the crankshaft 11 aligned in the front-rear direction (X-axis direction) of a vehicle (not shown).

  A crank chamber 4 is formed in the engine body 10 by a cylinder block 2 and a crankcase 3 fastened below the cylinder block 2. A crankshaft 11 is disposed in the crank chamber 4 so as to be rotatable around a rotation axis A (X axis) via a piston 12 and a connecting rod 13. As shown in FIG. 4, the crankshaft 11 is integrated with a crank pin 11a having a rotating shaft eccentric under the cylinder 2a and a counterweight 11b sandwiching the crankpin 11a connected to a main journal 11c. . As shown in FIG. 2, the rotation axis A of the crankshaft 11 is aligned with the height position (Z-axis direction) of the mating surface between the cylinder block 2 and the crankcase 3. The crankcase 3 is provided with an oil pan 5 (see FIG. 1) for storing oil (lubricating oil). The oil is pumped into the engine body 10 by an oil pump (not shown), supplied around the piston 12 and the crankshaft 11, and then dropped by its own weight and returned to the oil pan 5.

  The engine 100 is configured such that blow-by gas is recirculated through the intake manifold 30. Note that the blow-by gas indicates an unburned mixture containing hydrocarbons that have leaked into the crank chamber 4 from the gap between the inner wall surface of the cylinder 2a and the piston 12. Further, the blow-by gas is mixed with liquid oil having a large particle size scattered in the crank chamber 4 and oil mist having a small particle size (φ1 to 2 μm) smaller than this.

  Therefore, the oil separator 50 has a function of gas-liquid separation of blow-by gas. That is, as shown in FIGS. 2 and 3, the blow-by gas in the crank chamber 4 is sucked into the oil separator 50 by the negative pressure of the intake system (intake manifold 30) and the oil component (large particle size) contained in the blow-by gas Gas and oil mist of small particle size). The liquid oil after the gas-liquid separation is returned to the crank chamber 4 (oil pan 5). As shown in FIG. 1, downstream of the oil separator 50 is one PCV valve 80 (an example of a control valve) that controls the flow rate of blow-by gas, and the intake manifold 30 (FIG. 2) of the PCV valve 80 and the engine 100. A connection hose 81 is provided. As a result, the blow-by gas from which the oil has been separated is returned to the intake manifold 30 via the PCV valve 80 and the connection hose 81, whereby the crank chamber 4 is ventilated. Hereinafter, the configuration (structure) of the oil separator 50 will be described in detail.

(Detailed structure of oil separator)
As shown in FIGS. 1 and 3, the oil separator 50 includes a first portion 60 (an example of a first oil separator portion) and a second portion 70 (an example of a second oil separator portion). The first portion 60 is integrally formed with the cylinder block 2 in a state of being recessed in the arrow Y1 direction on the side wall 2b on the Y2 side of the cylinder block 2. Moreover, the 1st part 60 contains the recessed parts 60a and 60b (an example of one part which comprises a 1st chamber and a 2nd chamber) mutually partitioned by the X-axis direction across the partition wall part 60c. Further, the second portion 70 made of aluminum alloy also has a function as a cover member, and has recesses 70a and 70b (which constitute a first chamber and a second chamber) that are partitioned from each other in the X-axis direction with the holding portion 71 therebetween. An example of the other part).

  In this embodiment, the gasket 6 (see FIG. 3) is sandwiched from the side (Y2 side) of the cylinder block 2 with respect to the first portion 60, and the second portion 70 as the cover member is opposed to the arrow Y1 direction. The oil separator 50 is configured by being attached by the four bolt members 7 (see FIG. 1) in the state of being made. Moreover, when the 2nd part 70 is attached to the 1st part 60, while the recessed part 60a and the recessed part 70a oppose, the recessed part 60b and the recessed part 70b oppose. Thereby, as shown in FIG. 3, a first chamber 51 and a second chamber 52 which are partitioned from each other are formed inside the oil separator 50. As shown in FIGS. 1 and 3, the first chamber 51 and the second chamber 52 are disposed at substantially the same height as viewed in the horizontal direction (X-axis direction).

  As shown in FIGS. 2 and 3, the first portion 60 is provided on the blow-by gas suction passage 61 provided on the first chamber 51 side and on the second chamber 52 side and is separated from the blow-by gas. A drain passage 62 (an example of a discharge passage) for discharging oil to the oil pan 5. The suction passage 61 and the drain passage 62 are also formed in the crankcase 3 (see FIG. 1) in which a part of the lower end portion is connected (fastened) to the cylinder block 2. The suction passage 61 extending in the Z-axis direction includes a blow-by gas suction port 61a (see FIG. 2) that opens into the crank chamber 4, and a blow-by gas introduction port 61b (see FIG. 3) that opens into the first chamber 51. Have The suction passage 61 is three-dimensionally bent between the suction port 61a and the introduction port 61b.

  Therefore, as shown in FIG. 2, the blow-by gas sucked in the direction of the arrow Z1 from the suction port 61a once changes its direction in the direction of the arrow X2, and then changes its direction again in the direction of the arrow Z1 and passes through the suction passage 61. After that, as shown in FIGS. 3 and 7, the first chamber 51 is introduced into the first chamber 51 through the introduction port 61b and changed in the direction of the arrow Y2 due to the round shape of the ceiling portion 60d (see FIG. 7). Circulate. At this time, oil with a large particle size (liquid oil) is separated by repeating inertial collision with the inner wall surface 61c where the blow-by gas is bent. As a result, the suction passage 61 that is three-dimensionally bent is configured to serve as a liquid oil separation part.

  In addition, as shown in FIG. 4, the position of the suction inlet 61a (refer FIG. 2) is arrange | positioned in the downward area | region of the cylinder 2a. The suction passage 61 is bent in the direction of arrow X2 in the cylinder block 2, extends to a position between adjacent cylinders 2a, extends upward (in the direction of arrow Z1), and is connected to the recess 60a (first chamber 51). Yes. Further, the opening shape of the suction port 61a and the sectional shape (circular shape) of the bent suction passage 61 are different from each other, but the sectional areas are equal to each other. Further, a drain passage 62 is disposed at a position slightly separated from the suction passage 61 in the arrow X2 direction. As shown in FIGS. 2 and 3, the drain passage 62 has an oil inlet 62 a that opens to the second chamber 52 and an oil outlet 62 b (see FIG. 2) that opens to the crank chamber 4. The bottom surface 52 a of the second chamber 52 (including the bottom surface 70 e of the recess 70 b) is inclined so that the position of the oil inlet 62 a is at the lowest position in the second chamber 52.

  In the present embodiment, as shown in FIG. 2, the oil inlet 62a is positioned above the bottom dead center P of the piston 12 in the engine 100 (Z1 side), and the oil outlet 62b is a cylinder block. 2 is located below (Z2 side) lower end surface 2c. In this case, the height difference h from the oil inlet 62a to the oil outlet 62b is set to 100 mm or more. That is, even when the intake negative pressure of the engine body 10 reaches the maximum value (when the pressure loss on the gas flow path side is the maximum value), the oil level of the oil head (oil column) formed in the drain passage 62 Is maintained in the drain passage 62 so that the height difference h is secured. Further, the cross-sectional area S2 of the oil discharge port 62b is smaller than the cross-sectional area S1 of the oil inflow port 62a. A check valve 82 (an example of a backflow prevention structure) for preventing the oil flowing down the drain passage 62 from flowing back to the oil inlet 62a is attached to the oil outlet 62b. The force for closing the check valve 82 is set to be substantially the same as the mass of the oil head formed in the drain passage 62. Accordingly, the check valve 82 is opened as much as the oil head exceeds a predetermined height, and the oil is discharged from the oil discharge port 62b.

  In the present embodiment, as shown in FIGS. 3, 5, and 7, the second portion 70 includes a collecting member 65 disposed on the holding portion 71. The collecting member 65 is configured by stacking a plurality (six in this embodiment) of wire mesh members 66 in which a plurality of collecting holes 66a for collecting oil mist are arranged in a mesh shape. Each wire mesh member 66 is made of expanded metal. The expanded metal is manufactured by cutting the metal plate in a zigzag pattern and then stretching the metal plate in the direction in which the cut opens so as to process it into a rhombus or turtle-shaped mesh. The collection member 65 made of a wire mesh is very useful for oil mist collection in that it has excellent heat resistance under conditions exposed to high-temperature blow-by gas in addition to ease of manufacturing and shape processing. It is a suitable member (part).

  In the metal mesh member 66, as shown in FIG. 8, the ratio of the horizontal width SW (Y-axis direction) and the vertical width LW (Z-axis direction) in the diamond-shaped collection hole 66a is about 1: 2. Is formed. For example, the horizontal width SW is set to about 0.5 mm, and the vertical width LW is set to about 1 mm. The six metal mesh members 66 are overlapped with the meshes (the plurality of collection holes 66a) being shifted in the horizontal direction and the vertical direction. Further, as shown in FIG. 7, the collecting member 65 is arranged so that the longitudinal direction of the collecting holes 66a arranged in a mesh pattern coincides with the gravity direction (arrow Z2 direction) in which the collected oil flows down. It is mounted inside the second portion 70 (holding portion 71), and is configured so that oil can easily flow down using its own weight.

  Moreover, as shown in FIG. 5, the collection member 65 is made of resin in a state in which six metal mesh members 66 having the same plane area are stacked along the flow direction (arrow X2 direction) of the blow-by gas. It is sandwiched between the holding members 67a and 67b. Then, the six metal mesh members 66 (collecting members 65) sandwiched between the holding members 67a and 67b are inserted into the groove portion 71a of the holding portion 71 in the arrow Y2 direction and attached to the second portion 70. As a result, the collection member 65 is disposed between the first chamber 51 and the second chamber 52, and the small particle size contained in the blow-by gas that circulates from the first chamber 51 toward the second chamber 52. The oil mist is collected (captured) so as to serve as an oil mist separation unit.

  As shown in FIGS. 5 and 7, an opening 67c having an inner diameter of about 20 mm is formed in the central region of the holding members 67a and 67b. That is, the wire mesh member 66 is exposed inside the opening 67c in a state where the collection member 65 is mounted on the holding portion 71. Except for the exposed area of the wire mesh member 66, there are a holding portion 71 and a holding member 67a that partition the first chamber 51 and the second chamber 52, and the blow-by gas that has flowed into the first chamber 51 has an opening 67c (wire mesh member). 66), the flow is restricted. The blow-by gas is configured such that the entire amount of the blow-by gas passes through the collection member 65 in a state where the flow velocity is increased by the restriction of the opening 67c.

  Further, as shown in FIG. 5, the second portion 70 integrally has a rib-shaped collision plate 72 disposed in the path of the second chamber 52 after passing through the collecting member 65. In the second chamber 52, part of the oil collected and liquefied by the plurality of collection holes 66a of the wire mesh member 66 collides with the collision plate 72 due to the momentum of the blow-by gas flow. Here, the surface of the collision plate 72 may have fine undulations (unevenness). Furthermore, the oil may be easily repelled by using, for example, a resin coating material having oil repellency. Thereby, the oil which collided with the collision board 72 is favorably hold | maintained (captured) using a recessed part. Further, the oil flows down while being repelled on the surface of the recess and is easily guided to the bottom surface 52 a of the second chamber 52. In addition, it is preferable that the uneven | corrugated shape of the surface of the collision board 72 is formed so that a several stripe-shaped recessed part may extend linearly in the diagonally downward direction (the end spreading shape) or the downward direction (arrow Z2 direction). Further, oil that could not be collected from the blow-by gas when passing through the collecting member 65 also collides with the collision plate 72. As a result, the liquid oil is further captured by the collision plate 72. Further, the collision plate 72 includes a wall portion 72a that rises perpendicularly from the bottom surface 70e of the recess 70b in the second chamber 52, and a return portion 72b that is bent toward the collecting member 65 from the tip of the wall portion 72a. Thus, the blow-by gas is configured not to be sucked directly into the PCV valve 80 (see FIG. 3) beyond the collision plate 72. Further, a second chamber 52 having an enlarged volume is disposed downstream of the collision plate 72.

  Further, as shown in FIG. 6, a hollow portion 73 connected to the second chamber 52 is formed in the vicinity of the central portion of the collection member 65 and in the lower (Z2 side) holding portion 71. Therefore, the oil flowing down from the wire mesh member 66 flows through the cavity 73 to the bottom surface 52a of the second chamber 52 and is guided to the oil inlet 62a (see FIG. 3). Further, as shown in FIG. 3, the PCV valve 80 is screwed and fixed to the wall portion 70c on the opposite side of the holding portion 71 of the concave portion 70b. Therefore, the PCV valve 80 is disposed on the second chamber 52 side.

(Function when oil separator operates)
With the above configuration, the oil separator 50 functions as follows. Immediately after the engine 100 is started, blow-by gas is sucked from the suction port 61a by the negative pressure of the intake system. Thereby, as shown in FIG. 3, blow-by gas is immediately circulated through the suction passage 61 designed to have a pressure loss smaller than the head loss of oil. The blow-by gas repeats inertial collision with the inner wall surface 61c of the complicated suction passage 61. Thereby, oil having a large particle diameter is collected in the suction passage 61 including the first chamber 51. The liquid oil flows down the inner wall surface 61c and returns to the suction port 61a. The total amount of blow-by gas from which the liquid oil has been separated is guided to the central region of the cross-section of the passage in the collecting member 65 while increasing the flow velocity of the blow-by gas flow.

  Then, oil mist having a small particle diameter is collected by the collecting member 65. That is, the oil that has collected the oil mist and liquefied the wire mesh member 66 flows down. Further, the oil collected by the metal mesh member 66 is also blown to the downstream collision plate 72 and flows down through the wall portion 72a. Furthermore, the oil mist also falls by gravity from the blow-by gas flow whose flow velocity is reduced in the second chamber 52 having a large volume downstream of the collision plate 72. Thus, the oil separated on the second chamber 52 side including the collecting member 65 is collected on the bottom surface 52a. The oil collected on the bottom surface 52 a is drawn into the oil inlet 62 a and absorbed by the oil head in the drain passage 62. In the drain passage 62, the oil head height is maintained such that the oil head loss is larger than the pressure loss on the gas flow path side at that time by a predetermined amount. In addition, the oil component exceeding the pressure balance with the blow-by gas side of the oil head pushes down the check valve 82, whereby the oil discharged from the oil discharge port 62b is returned to the oil pan 5 (see FIG. 2). The blow-by gas from which the oil component has been separated is returned to the intake manifold 30 via the PCV valve 80.

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

  In the present embodiment, as described above, the blow-by gas suction passage 61 provided on the first chamber 51 side is formed in the first portion 60, and the first chamber 51 and the second chamber 52 are formed in the second portion 70. And a collecting member 65 that collects oil mist contained in the blow-by gas and a collision that collides oil collected by the collecting member 65 while being disposed in the path on the second chamber 52 side. A plate 72 is provided. Thereby, in the oil separator 50, the blow-by gas generated in the crank chamber 4 is introduced into the first chamber 51 through the suction passage 61, and the entire amount of the blow-by gas introduced into the first chamber 51 is reduced. Then, a one-way blow-by gas flow can be created in which the collection member 65 is passed through the second chamber 52. At this time, while collecting the oil mist by the collecting member 65, the collected oil can also collide with the collision plate 72 to capture the liquid oil and return it from the drain passage 62 to the crank chamber 4. That is, since oil can be separated from the entire amount of blow-by gas introduced without causing uneven distribution of the blow-by gas flow in the oil separator 50, the oil separation ability of the oil separator 50 as a whole can be sufficiently exhibited. Can do.

  Further, in the present embodiment, the first portion 60 includes a drain passage 62 that discharges oil, and the oil inlet 62 a that opens to the second chamber 52 of the drain passage 62 is located below the bottom dead center P of the piston 12 in the engine 100. The oil discharge port 62 b that opens in the engine 100 in the drain passage 62 is positioned below the lower end surface 2 c of the cylinder block 2. Thereby, even when the oil separator 50 is provided in the cylinder block 2, the height difference h of the drain passage 62 from the oil inlet 62a to the oil outlet 62b can be sufficiently secured. Accordingly, since the oil head can be reliably formed in the oil drain passage 62, the blow-by gas can be reliably circulated through the blow-by gas suction passage 61 having a pressure loss smaller than that of the oil head. Also by this, the blow-by gas from the crank chamber 4 can be easily circulated in the order of the first chamber 51, the collecting member 65, and the second chamber 52.

  In the present embodiment, the first portion 60 is provided integrally with the cylinder block 2, and the second portion 70 is configured by a cover member that covers the first portion 60. Thus, the oil separator 50 having the first chamber 51 and the second chamber 52 can be provided in the engine 100 only by attaching the second portion 70 to the cylinder block 2. That is, unlike the case where an oil separation member as a separate part is incorporated in the pre-process for attaching the second portion 70, the manufacturing process of the oil separator 50 can be simplified and the internal structure can be simplified.

  In this embodiment, the PCV valve 80 for controlling the flow of blow-by gas is provided on the second chamber 52 side of the second portion 70. Thereby, since the function which adjusts the flow of blow-by gas can be given to the 2nd part 70, the recirculation path | route of blow-by gas can be easily comprised only by connecting the PCV valve 80 and the intake manifold 30. .

  In this embodiment, the cross-sectional area S2 of the oil discharge port 62b is smaller than the cross-sectional area S1 of the oil inlet 62a provided in the cylinder block 2. As a result, the oil separated from the blow-by gas can smoothly flow into the oil inlet 62a, and the oil is easily filled in the drain passage 62 because the sectional area S2 is smaller than the sectional area S1. can do. That is, since the oil head can be quickly formed in the drain passage 62, the blow-by gas is quickly formed in the suction passage 61 of the blow-by gas that causes a quick pressure formation and a pressure loss smaller than the oil head in the oil drain passage 62. Can be distributed.

  In the present embodiment, the drain passage 62 is provided with a check valve 82 for preventing the oil flowing down the drain passage 62 from flowing back to the oil inlet 62a. Thereby, it is possible to prevent the oil filled in the drain passage 62 from being returned to the second chamber 52 and taken away from the oil separator 50 to the intake system (intake manifold 30). Further, since no back flow of oil occurs in the drain passage 62, it is possible to reliably prevent the blow-by gas from being sucked into the second chamber 52 through the oil drain passage 62. Therefore, blow-by gas can be reliably sucked into the first chamber 51 side through the suction passage 61, so that the oil separation ability of the oil separator 50 can be reliably maintained.

  In the present embodiment, the collection member 65 includes a wire net member 66 in which collection holes 66a for collecting oil mist are arranged in a mesh shape. As a result, oil mist can be collected with high efficiency by the metal mesh member 66, and the oil liquefied and accumulated in the metal mesh member 66 can be quickly discharged from the metal mesh member 66. Further, compared to the case where a filter made of filter paper or the like is provided, the wire mesh member 66 itself is excellent in oil discharge performance, so that clogging of the collection hole 66a is suppressed and the passage resistance (pressure loss) is kept low. Can do. Thereby, the flow volume of the blow-by gas which passes the part of the metal-mesh member 66 can be ensured appropriately. As a result, by quickly discharging the oil collected from the blow-by gas, the flow rate of the blow-by gas can be appropriately secured and the ventilation performance of the blow-by gas can be maintained.

  Further, in the present embodiment, the collection member 65 is disposed in the second portion so that the longitudinal direction of the collection holes 66a arranged in a mesh pattern matches the gravitational direction in which the collected oil flows (arrow Z2 direction). 70 inside. Thereby, the oil collected by the part of the metal mesh member 66 can flow down quickly and reliably along the longitudinal direction of the collection hole 66a by the weight of the oil, and can be discharged from the metal mesh member 66. Moreover, since clogging of the collection hole 66a is suppressed, further oil can be collected, and the oil separation ability of the collection member 65 can be maintained high.

  In this embodiment, the height difference h from the oil inlet 62a to the oil outlet 62b in the drain passage 62 provided in the cylinder block 2 is set to 100 mm or more. Thereby, even when the intake negative pressure of the engine body 10 reaches the maximum value, the oil level of the oil head formed in the drain passage 62 can be reliably held in the drain passage 62.

  In the present embodiment, the collecting member 65 is configured by stacking six metal mesh members 66 along the flow direction of the blow-by gas. As a result, the oil component can be effectively (reliably) collected from the oil mist by the metal mesh members 66 that are stacked one upon the other instead of one sheet.

  In the present embodiment, the suction passage 61 is bent between the suction port 61a and the introduction port 61b, so that liquid oil that collects large-diameter oil contained in blow-by gas from the crank chamber 4 is collected. The collecting member 65 that is a separation unit and divides the first chamber 51 and the second chamber 52 is an oil mist separation that collects an oil mist having a small particle diameter contained in the blow-by gas after passing through the liquid oil separation unit. Part. Thereby, the blow-by gas after the oil having a large particle diameter is mainly collected in the suction passage 61 and the oil content is reduced can be circulated to the downstream collecting member 65, so that the collecting member 65 The oil mist can be efficiently collected by the collecting member 65 in a state where the probability that the liquid oil is clogged in the wire mesh member 66 is effectively reduced. In addition, the oil separation function of the oil separator 50 in which the liquid oil separation part and the oil mist separation part are integrated to reduce the number of parts (simple structure) can be maintained high.

[First Modification]
With reference to FIG. 9, the 1st modification of the said embodiment is demonstrated. In the first modified example, an example in which a structure (oil flow lower portion 74) is provided at the lower portion of the collecting member 65 so that the liquid oil separated from the gas and liquid can be more easily guided to the bottom surface 52a of the second chamber 52 is described. To do.

  That is, as shown in FIG. 9, an oil flow lower portion 74 is formed in the holding portion 71 in the vicinity of the central portion of the collecting member 65 in the Y-axis direction and on the lower side (Z2 side). The oil flow lower portion 74 has an inclined surface 74a that is inclined from the lower end portion 65a of the collecting member 65 toward the bottom surface 52a on the collision plate 72 side (X2 side). Other configurations are the same as those in the above embodiment.

(Effect of the first modification)
In the first modified example, as described above, by providing the oil flow lower portion 74 having the inclined surface 74a, the liquid oil dropped from the collecting member 65 (metal mesh member 66) is caused to flow down the inclined surface 74a to the bottom surface 52a. It can be easily reached. Therefore, the oil separated by the collecting member 65 can be recovered with high efficiency and returned to the oil pan 5. The remaining effects of the first modified example are similar to those of the aforementioned embodiment.

[Second Modification]
With reference to FIG. 10, the 2nd modification of the said embodiment is demonstrated. In the second modification, an example in which six metal mesh members 66 are integrated using a rubber member 68 will be described.

  That is, as shown in FIG. 10, the collection member 265 is attached to the holding portion 71 of the second portion 70. In the collecting member 265, a rubber member 68 vulcanized around the wire mesh member 66 is bonded in a circumferential shape in a state where six wire mesh members 66 having the same plane area are stacked. In addition, since the rubber member 68 is formed in a frame shape, the wire net member 66 exposed from the opening 71b is also formed in a rectangular shape. Other configurations are the same as those in the above embodiment.

(Effect of the second modification)
In the second modification, as described above, the periphery of the six metal mesh members 66 is fixed using the rubber member 68 in a state where the metal mesh members 66 are stacked. Accordingly, the six metal mesh members 66 can be easily integrated by the rubber member 68, and the collecting member 265 can rattle against the holding portion 71 of the second portion 70 by using the frictional force of the rubber member 68. It can be accommodated (fixed) without. The remaining effects of the second modification are similar to those of the aforementioned embodiment.

[Third Modification]
A third modification of the above embodiment will be described with reference to FIGS. 3, 11, and 12. In this third modified example, an example will be described in which the collecting member 365 is formed by bending a plurality of strip-shaped metal mesh sheets 366 by bending a plurality of metal mesh members 66 by six.

  That is, as shown in FIG. 11, the collecting member 365 is formed by bending a plurality of strip-shaped wire mesh sheets 366 that were originally one sheet. The wire mesh sheet 366 before being bent is alternately connected with a metal mesh portion 367 which has a collection hole 66a and is made into an expanded metal, and a bent portion 66b which does not have the collection hole 66a and can be bent. Yes. And the collection member 365 in which the six metal-mesh parts 367 meander and reciprocate meander is formed by alternately folding back the metal-mesh sheet | seats 366 in the bending part 66b. In the natural state, the collection member 365 is extended in the X-axis direction using the elastic force of the bent portion 66b.

  In addition, the holding portion 371 of the second portion 70 includes a groove portion 371a and an opening 371b having an inner diameter of about 20 mm. Then, as shown in FIG. 12, the holding member 365 is folded in the X-axis direction while the direction in which the bent portion 66b (see FIG. 11) extends is aligned with the Z-axis direction (gravity direction). It is configured to be inserted into the second portion 70 by being inserted into the groove portion 371a of the 371 in the direction of the arrow Y2. As a result, the collecting member 365 is extended in the X-axis direction using the elastic force (restoring force) of the bent portion 66b, and does not rattle against the groove portion 371a of the holding portion 371. It is configured to be accommodated (fixed). The bent portion 66b located on the Y1 side of the collecting member 365 is in contact with the gasket 6 (see FIG. 3) without any gap. Other configurations are the same as those in the above embodiment.

(Effect of the third modification)
In the third modified example, as described above, the strip-shaped wire mesh sheet 366 is folded a plurality of times, so that the six wire mesh portions 367 folded back to each other are overlapped to constitute the collecting member 365. Thereby, the collection member 365 can be accommodated (fixed) without rattling with respect to the groove part 371a of the holding part 371 using the restoring force of the bent part 66b.

  Further, in the third modified example, the collecting member 365 is configured by inserting six wire mesh portions 367 that are folded back in a state where the extending direction of the bent portion 66b is aligned with the Z-axis direction (gravity direction) into the groove portion 371a. . Thus, unlike the case where the oil flowing down the wire mesh portion 367 stays in the portion of the bent portion 66b without the collection hole 66a when the extending direction of the bent portion 66b is aligned in the Y-axis direction, the wire mesh portion 367. The oil collected in the above can be quickly and reliably flowed down along the direction of gravity and reliably discharged from the lower end portion 65a of the collecting member 365. The remaining effects of the third modification are similar to those of the aforementioned embodiment.

[Modification]
It should be thought that embodiment disclosed this time is an illustration and restrictive at no points. The scope of the present invention is shown not by the description of the above-described 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 embodiment and the first to third modifications thereof, the first portion 60 is formed integrally with the cylinder block 2, but the present invention is not limited to this. That is, the first portion 60 may be configured separately from the cylinder block 2, and an oil separator in which the first portion 60 and the second portion 70 are combined in advance may be fixed to the side wall portion 2 b of the cylinder block 2.

  Moreover, in the said embodiment and its 1st-3rd modification, although the oil discharge port 62b of the drain passage 62 was located below rather than the lower end surface 2c of the cylinder block 2, this invention is not limited to this. That is, the oil discharge port 62b may be positioned at the height of the lower end surface 2c.

  Moreover, in the said embodiment and its 1st-3rd modification, although the oil separator 50 was arrange | positioned in the side wall part 2b by the side of Y2 of the cylinder block 2, this invention is not limited to this. That is, you may arrange | position in places other than the side wall part 2b by the side of Y2 of the cylinder block 2 according to the mounting direction of the engine 100, etc.

  Moreover, in the said embodiment and its 1st-3rd modification, although the 2nd part 70 (cover member) was comprised using the aluminum alloy, this invention is not limited to this. For example, you may comprise the 2nd part 70 using the resin material (nylon-type resin material containing glass fiber) which has oil resistance, heat resistance, chemical resistance, and sufficient intensity | strength. In this case, the six metal mesh members 66 may be integrally molded at the time of manufacturing the second portion 70 by using an insert molding method.

  Moreover, in the said embodiment and its 1st-3rd modification, although 6 sheets of the metal-mesh members 66 which have one type of roughness were piled up, the collection member 65 (265, 365) was comprised, It is not limited to this. That is, the collection member 65 (265, 365) may be configured by combining a plurality (two or more) of wire mesh members having different roughness.

  Moreover, in the said embodiment and its 1st-3rd modification, although the return part 72b was provided in the collision board 72, this invention is not limited to this. Instead of providing the return portion 72b, a “collision plate” may be provided in which the wall portion 72a is inclined slightly forward toward the collecting member 65 with respect to the bottom surface 70e.

  Moreover, in the said embodiment and its 1st-3rd modification, although the check valve 82 was provided in the drain channel | path 62, this invention is not limited to this. The drain passage 62 may be configured such that the cross-sectional area S2 of the oil discharge port 62b is smaller than the cross-sectional area S1 of the oil inlet 62a without providing the check valve 82. In this case, the inner diameter may be decreased gradually or stepwise from the oil inlet 62a toward the oil outlet 62b, or may be configured to be throttled in the vicinity of the oil outlet 62b.

  Moreover, in the said embodiment, although the 6 metal-mesh members 66 were inserted | pinched between a pair of holding members 67a and 67b, the collection member 65 was comprised, However, This invention is not limited to this. That is, the collecting member 265 of the second modification may be sandwiched between holding members 67a and 67b (see FIG. 5) and attached to the second portion 70, or the collecting member 365 of the third modification may be held. The second portion 70 may be mounted by being sandwiched between the members 67a and 67b (see FIG. 5).

  Moreover, in the said embodiment and its 1st-3rd modification, the 1st chamber 51 and the 2nd chamber 52 were arrange | positioned in the same height position seeing in a horizontal direction (X-axis direction), but this invention is this. Not limited to. The first portion 60 and the second portion 70 are arranged so that the first chamber 51 is disposed relatively obliquely below and the second chamber 52 is disposed relatively obliquely above with the collection member 65 interposed. It may be formed. Since the bottom surface 52a of the second chamber 52 is disposed higher, the height difference h of the drain passage 62 can be easily ensured.

  In the above-described embodiment and the first to third modifications thereof, in the naturally aspirated engine 100, one PCV valve 80 is provided in the oil separator 50 and returned to the intake manifold 30, but the present invention is not limited to this. I can't. That is, in addition to the PCV valve 80, in the internal combustion engine with a supercharger, the second PCV valve (control valve) that allows the return of the blow-by gas to the portion of the intake passage upstream of the intake side supercharger (compressor). ) May be further provided.

  Moreover, in the said embodiment and its 1st-3rd modification, although the example which applied this invention to the engine 100 for motor vehicles was shown, this invention is not limited to this. For example, the present invention may be applied to an oil separator 50 mounted on an internal combustion engine for equipment.

2 Cylinder block 2c Lower end surface 12 Piston 50 Oil separator 51 First chamber 52 Second chamber 60 First portion (first oil separator portion)
60a, 60b recess (one portion constituting the first chamber and the second chamber)
61 Suction passage 62 Drain passage (discharge passage)
62a Oil inlet 62b Oil outlet 65, 265, 365 Collection member 66 Wire mesh member 66a Collection hole 70 Second part (second oil separator part, cover member)
70a, 70b Recessed part (the other part constituting the first chamber and the second chamber)
72 Collision plate 80 PCV valve (control valve)
100 engine (internal combustion engine)

Claims (7)

A first oil separator portion provided in a cylinder block of an internal combustion engine and having one portion constituting a first chamber and a second chamber;
The other portion constituting the first chamber and the second chamber, and being attached to the first oil separator portion from a side of the cylinder block, thereby being partitioned together with the first oil separator portion. A second oil separator section that forms the first chamber and the second chamber,
The first oil separator portion includes a blow-by gas suction passage provided on the first chamber side, and a discharge passage that is provided on the second chamber side and discharges oil separated from the blow-by gas,
The second oil separator is disposed between the first chamber and the second chamber and collects oil mist contained in blowby gas, and the passage after the collection member has passed. A collision plate disposed in the path on the second chamber side and colliding with the oil collected by the collection member;
An oil inlet opening to the second chamber of the discharge passage is located above a piston bottom dead center in the internal combustion engine, and an oil discharge port opening to the inside of the internal combustion engine of the discharge passage is the cylinder An oil separator located below the bottom edge of the block. The first oil separator portion is provided integrally with the cylinder block,
2. The oil separator according to claim 1, wherein the second oil separator portion is configured by a cover member that covers the first oil separator portion.   The oil separator according to claim 1 or 2, wherein the second oil separator section further includes a control valve disposed on the second chamber side and controlling a flow of blow-by gas.   The cross-sectional area of the oil discharge port provided in the cylinder block is smaller than the cross-sectional area of the oil inlet port provided in the cylinder block in the oil discharge passage. The oil separator according to item 1.   The oil separator according to claim 4, wherein the discharge passage has a backflow prevention structure for preventing the oil flowing down the discharge passage from flowing back to the oil inlet side.   The oil separator according to any one of claims 1 to 5, wherein the collection member is made of a wire mesh in which collection holes for collecting the oil mist are arranged in a mesh shape.   The collection member is disposed inside the second oil separator portion so that the longitudinal direction of the collection holes arranged in a mesh shape matches the gravity direction in which the collected oil flows down. The oil separator according to claim 6.

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