JP2018178876A - Internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an internal combustion engine having an oil separator which can exhibit a high oil separation capacity while suppressing an increase in pressure loss in a wide flow rate area of an oil-containing gas.SOLUTION: An oil separator 10 comprises a plurality of partitioning plates 26, 28. A plurality of the partitioning plates 26, 28 are formed so that their tips are overlapped on each other and alternately extended when viewed from a longitudinal direction of a separator chamber 12, toward a center of the separator chamber 12 from a pair of inner sidewalls 18, 20 of the separator chamber 12 which oppose each other. An internal combustion engine 1 further comprises: an actuator 50 for making a communication cross section area A between the tips of a plurality of the partitioning plates 26, 28 and one of a pair of the inner sidewalls 18, 20 opposing the tips variable; and an ECU 60 for controlling the actuator 50 so that the communication cross section area A is increased in the case that a flow rate Q of a blowby gas flowing into the separator chamber 12 is high compared with the case that the flow rate Q is low.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an internal combustion engine, and more particularly to an internal combustion engine provided with an oil separator including at least a labyrinth structure.

  For example, Patent Document 1 discloses an oil separator of an internal combustion engine. The oil separator comprises two oil separation mechanisms arranged in series. One of these oil separation mechanisms is configured such that the open area of the blowby gas inlet is relatively small and the diameter of the nozzle is relatively small. The other oil separation mechanism is configured such that the opening area of the blowby gas inlet is relatively large, and the diameter of the nozzle is relatively large.

  Furthermore, according to the above oil separator, when the flow rate of the blowby gas is small, the blowby gas is introduced into the oil separation mechanism in which the opening area of the blowby gas inlet is relatively small. On the other hand, when the flow rate of the blowby gas is high, most of the blowby gas is introduced into the oil separation mechanism in which the opening area of the blowby gas inlet is relatively large.

Unexamined-Japanese-Patent No. 2010-144676 JP, 2005-061257, A Japanese Utility Model Application Publication No. 2-034407

  According to the oil separator described in Patent Document 1, when the flow rate of the blowby gas is large, the oil separation mechanism including the blowby gas inlet and the nozzle with a large opening area mainly functions, so pressure loss ( Passage resistance) can be reduced. However, when the flow rate of the blowby gas is high, the number of sites through which the blowby gas passes in the oil separator is reduced. For this reason, although the pressure loss can be reduced, there is a concern that the oil separation capacity may be reduced.

  The present invention has been made in view of the problems as described above, and is provided with an oil separator capable of exhibiting high oil separation ability while suppressing an increase in pressure loss in a wide flow rate range of oil-containing gas. An object of the present invention is to provide an internal combustion engine.

  An internal combustion engine according to the present invention includes an oil separator. The oil separator is formed in a longitudinal shape, and an inlet for an oil-containing gas provided at one end in the longitudinal direction, an outlet for the oil-containing gas provided at the other end in the longitudinal direction, A plurality of separator chambers having an inner wall, and a plurality of staggered sections extending from the pair of inner walls toward the center of the separator chamber such that the tips overlap each other when viewed from the longitudinal direction And a partition plate. A labyrinth passage is formed inside the separator chamber by the plurality of partition plates. The internal combustion engine has a passage cross-sectional area between at least one tip of the plurality of partition plates and one of the pair of inner walls facing the tip, and a pair of the plurality of partition plates adjacent to each other When the flow rate of the oil-containing gas flowing into the separator chamber is high, an actuator that makes one or both of the minimum passage cross-sectional areas between the partition plates variable and the flow passage compared to when the flow rate is low A controller for controlling the actuator such that one or both of the cross-sectional area and the minimum passage cross-sectional area are increased.

  According to the present invention, when the flow rate of the oil-containing gas flowing into the separator chamber is high, one of the passage cross-sectional area and the minimum passage cross-sectional area in the labyrinth passage is higher than when the flow rate is low. The actuators are controlled to increase both. According to such control, it is possible to ensure that the flow velocity of the blowby gas flowing through the labyrinth passage is high when the flow rate is small, and to suppress the flow velocity of the blowby gas flowing through the labyrinth passage too high even when the flow rate is large. The oil separator can properly exhibit the oil separation ability if the flow rate of the blowby gas is appropriate. In addition, according to the above control, without increasing the area through which the blowby gas passes in the separator chamber at a large flow rate (without causing a decrease in the oil separation ability due to the reduction of the area), the increase in pressure loss is suppressed can do. Therefore, according to the present invention, high oil separation ability can be exhibited while suppressing an increase in pressure loss in a wide flow rate range of blowby gas.

It is a figure for demonstrating the structure of the principal part of the internal combustion engine which concerns on Embodiment 1 of this invention. It is a figure for demonstrating an example of a structure of the impactor nozzle shown in FIG. It is a figure for demonstrating control of the actuator which concerns on Embodiment 1 of this invention. It is a figure for demonstrating the structure of the principal part of the internal combustion engine which concerns on Embodiment 2 of this invention. It is a figure for demonstrating the structure of the 1st modification of the internal combustion engine which concerns on Embodiment 2 of this invention. It is a figure for demonstrating the structure of the 2nd modification of the internal combustion engine which concerns on Embodiment 2 of this invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. However, when the number of the number, the number, the quantity, the range, etc. of each element is mentioned in the embodiment shown below, the mention is made unless otherwise specified or the number clearly specified in principle. The present invention is not limited to the above numbers. In addition, the structures and the like described in the embodiments described below are not necessarily essential to the present invention, unless otherwise specified or clearly specified in principle. In the drawings, the same or similar components are denoted by the same reference numerals.

Embodiment 1
First, Embodiment 1 of the present invention will be described with reference to FIGS. 1 to 3.

1. Configuration of Internal Combustion Engine According to Embodiment 1 FIG. 1 is a view for explaining the configuration of a main part of an internal combustion engine 1 according to Embodiment 1 of the present invention. As shown in FIG. 1, the internal combustion engine 1 includes an oil separator 10, an actuator 50, and an electronic control unit (ECU) 60.

1-1. Oil Separator The oil separator 10 is disposed, as an example, in a head cover (not shown) in order to separate oil from blow-by gas which is an example of oil-containing gas flowing in the internal combustion engine 1. The cross-sectional shape of the oil separator 10 is represented by FIG.

  The oil separator 10 is provided with a separator chamber 12 formed in a longitudinal shape. A blowby gas inlet 14 is provided at one end in the longitudinal direction of the separator chamber 12, and a blowby gas outlet 16 is provided at the other end in the longitudinal direction. Further, the separator chamber 12 is provided with a pair of inner walls 18 and 20 facing each other. The inner wall 18 is an inner wall on the upper side in the vertical direction shown in FIG. 1 and hereinafter also referred to as an “upper inner wall 18”. Similarly, the vertically lower inner wall 20 is also referred to as “lower inner wall 20”.

  A labyrinth portion 22 and an impactor portion 24 are provided in the separator chamber 12. More specifically, in the example shown in FIG. 1, the labyrinth portion 22 is provided on the upstream side of the flow of the blowby gas, and the impactor portion 24 is provided on the downstream side thereof.

1-1-1. The Labyrinth Section The labyrinth section 22 is provided with a plurality of partition plates 26, 28 which are formed to extend alternately from the pair of inner walls 18, 20 toward the center of the separator chamber 12 as shown in FIG. 1. More specifically, the plurality of (two, by way of example) partition plates 26 are formed to extend downward in the vertical direction from the upper inner wall 18, and hereinafter also referred to as "upper partition plate 26". In addition, a plurality of (for example, three) partition plates 28 are formed to extend vertically upward from the lower inner wall 20, and are also referred to as "lower partition plates 28".

  Furthermore, when viewed from the longitudinal direction of the separator chamber 12, the upper partition plate 26 and the lower partition plate 28 extend such that the tip portions of the partition plates 26, 28 overlap with each other. A labyrinth passage 30 is formed inside the separator chamber 12 by the plurality of partition plates 26 and 28 configured as described above.

(Oil separation using labyrinth)
According to the labyrinth portion 22 described above, the flow passage of the blowby gas is formed into a labyrinth by the plurality of partition plates 26, 28. Since the floating distance of oil (oil mist) becomes long by this, it can promote that oil mist falls by dead weight. Further, according to the plurality of partition plates 26 and 28 formed to make the flow path of the blowby gas in a labyrinth manner as described above, when the blowby gas is diverted, the oil mist has a plurality of partition plates by its own inertia. It is also possible to expect an effect of being collected by colliding with 26, 28. Oil is also separated from the blowby gas by such a collection effect.

1-1-2. Impactor Section The impactor section 24 includes an impactor nozzle 32, an impactor wall 34, and a pair of upper partition plates 36 and lower partition plates 38 that constitute the impactor nozzle 32. As shown in FIG. 2, these partition plates 36 and 38 extend in the vertical direction in the separator chamber 12 so as to close the flow path of the blowby gas. The impactor nozzle 32 is formed at the center of the pair of partition plates 36, 38.

  FIG. 2 is a view for explaining an example of the configuration of the impactor nozzle 32 shown in FIG. As shown in FIG. 2, the upper partition plate 36 extends vertically downward from the upper inner wall 18, and the lower partition plate 38 extends vertically upward from the lower inner wall 20. There is. As shown in FIG. 2, a part of the hole of the impactor nozzle 32 is formed in the upper partition plate 36, and the remaining part of the hole of the impactor nozzle 32 is formed in the lower partition plate 38. The lower partition plate 38 is moved by the actuator 50 as described later. In the example shown in FIG. 2, the cross-sectional shape of the impactor nozzle 32 is an oval, but it is not limited to this and may be any other shape such as an ellipse or a square.

  Further, as shown in FIG. 1, the impactor wall 34 extends vertically upward from the lower inner wall 20. The impactor wall 34 is disposed to face the impactor nozzle 32 when viewed from the longitudinal direction of the separator chamber 12 (in other words, to block the path of the blowby gas which has passed through the impactor nozzle 32).

(Oil separation using impactor)
According to the impactor unit 24 configured as described above, the blowby gas whose flow velocity is increased by passing through the impactor nozzle 32 collides with the impactor wall 34, thereby capturing oil (oil mist) in the blowby gas. Can be collected (inertial collision type). Such an impactor portion 24 can also separate oil from blowby gas. Moreover, such an impactor portion 24 is advantageous for separation of oil of small particle size.

1-1-3. Remaining Configuration of Oil Separator The separator chamber 12 is provided with an inlet wall 40 which constitutes a part of the wall of the inlet 14 as shown in FIG. The inlet wall 40 is moved by the actuator 50, as described below with reference to FIG.

  Furthermore, as shown in FIG. 1, the separator chamber 12 is provided with a plurality of oil pits 42 in the lower inner wall 20. A plurality of oil pits 42 are provided in the lower inner wall 20 at the portions connecting the plurality of lower partition plates 28 of the labyrinth portion 22, the lower partition plate 38 and the impactor wall 34 of the impactor portion 24, and the inlet wall 40. It is done. According to these oil pits 42, the oil attached to the wall surfaces of the labyrinth portion 22 and the impactor portion 24 can be discharged to the outside of the separator chamber 12.

1-2. Actuator The actuator 50 is configured to displace a portion of the lower inner wall 20 up and down along the vertical direction. The movable system of a part of the lower inner wall 20 by the actuator 50 is not particularly limited, but is, for example, an electric system. Here, “a part of the lower inner wall 20” means, among the lower inner walls 20, a plurality of lower partition plates 28 of the labyrinth portion 22, a lower partition plate 38 of the impactor portion 24, and an inlet wall It is a part connected to each of 40.

  The portion to be moved by the actuator 50 may be the upper inner wall 18 instead of or together with the lower inner wall 20. Further, each portion connected to each of the plurality of lower partition plates 28 of the labyrinth portion 22, the lower partition plate 38 of the impactor portion 24, and the inlet wall 40 is the whole of each portion as in the example of this embodiment. May be configured to be integrally movable, or each of the portions may be configured to be independently movable. In addition, not all of the respective portions but at least one lower partition plate 28 may be a movable target. The same applies to the case where the upper inner wall 18 is moved.

  By displacing the part of the lower inner wall 20 up and down along the vertical direction by the actuator 50, the lower partition plate 28 is displaced up and down accordingly (in other words, the upper partition plate 26 adjacent to each other) The amount of overlap with the lower partition plate 28 changes). As a result, the passage cross-sectional area A between the respective tips of the plurality of partition plates 26, 28 and one of the pair of inner walls 18, 20 opposed to the respective tips is changed.

  Further, when the actuator 50 displaces the part of the lower inner wall 20 up and down in the vertical direction, the lower partition plate 38 is displaced up and down accordingly. As a result, the opening area of the impactor nozzle 32 is changed. More specifically, the upper partition plate 36 and the lower partition plate 38 are configured such that the end portions (ends on the side where the holes of the impactor nozzle 32 are formed) of the separator chambers 12 overlap with each other when viewed from the longitudinal direction. It is done. Therefore, the opening area of the impactor nozzle 32 is changed as the amount of overlap between the tip portions of the upper partition plate 36 and the lower partition plate 38 changes with the operation of the actuator 50. The hole of the impactor nozzle 32 may be formed only in one of the pair of partition plates 36, 38, unlike the configuration shown in FIG. In this example, the ratio of the opening area of the impactor nozzle 32 closed by the other of the partition plates 36 and 38 may be adjusted by the movement of one or both of the pair of partition plates 36 and 38.

  Further, by vertically displacing the part of the lower inner wall 20 in the vertical direction by the actuator 50, the inlet wall 40 is displaced up and down accordingly. As a result, the passage cross-sectional area of the blow-by gas inlet 14 is changed.

1-3. Control device The internal combustion engine 1 includes the ECU 60 described above in order to execute various engine control. The actuator 50 described above is electrically connected to the ECU 60. That is, the ECU 60 functions as a control device that controls the actuator 50.

2. Control of Actuator According to Embodiment 1 FIG. 3 is a diagram for explaining control of the actuator 50 according to Embodiment 1 of the present invention. In the present embodiment, the ECU 60 sets the passage cross sectional area A of the labyrinth portion 22, the opening area of the impactor nozzle 32, and the passage cross sectional area of the inflow port 14 in accordance with the flow rate Q of the blowby gas flowing into the separator chamber 12. The actuator 50 is controlled to be increased or decreased.

  The flow rate Q of the blowby gas can be estimated, for example, by the following method. That is, the relationship between the engine operating conditions (more specifically, the engine rotational speed, the coolant temperature and the fuel injection amount (in-cylinder pressure)) and the flow rate Q is obtained in advance by experiment etc. I will memorize as a map. Thereby, the ECU 60 can estimate the flow rate Q of the blowby gas according to the engine operating condition by referring to such a map during the operation of the internal combustion engine 1.

2-1. Control at Low Flow Rate More specifically, FIG. 3A shows the operating state of the actuator 50 at low flow rate where the flow rate Q of the blowby gas decreases. When the flow rate is small, the ECU 60 controls the actuator 50 so that the part of the lower inner wall 20 is displaced upward in the vertical direction, as shown in FIG. 3 (A).

  As a result, when the flow rate is small, the passage cross-sectional area A of the labyrinth portion 22 is reduced. In addition, when the flow rate is small, the opening area of the impactor nozzle 32 and the passage cross-sectional area of the inlet 14 are also reduced.

2-2. Control at Large Flow Rate On the other hand, FIG. 3B shows the operating state of the actuator 50 at a large flow rate at which the flow rate Q of the blowby gas increases. When the flow rate is large, the ECU 60 controls the actuator 50 so that the part of the lower inner wall 20 is displaced downward in the vertical direction, as shown in FIG. 3 (B).

  As a result, when the flow rate is large, the passage cross-sectional area A of the labyrinth portion 22 is increased as compared to the time when the flow rate is small as shown in FIG. Further, at the large flow rate, the opening area of the impactor nozzle 32 and the passage cross-sectional area of the inflow port 14 are also increased compared to the small flow rate.

3. Effects of Control of Actuator According to Embodiment 1 According to the control of the actuator 50 according to the embodiment described above, when the flow rate Q of the blowby gas is small, the passage cross sectional area A of the labyrinth portion 22 and the impactor nozzle 32 And the passage cross-sectional area of the inlet 14 are respectively reduced. As a result, even if the flow rate Q of the blowby gas is small, it is possible to ensure a high flow velocity of the blowby gas flowing through each part. Therefore, when the flow rate is small, the oil separation ability of the labyrinth portion 22 and the impactor portion 24 can be appropriately exhibited.

  Further, according to the control of the present embodiment, when the flow rate Q of the blowby gas is large, the passage cross sectional area A of the labyrinth portion 22, the opening area of the impactor nozzle 32, and the passage cross sectional area of the inflow port 14 are respectively increased. . Accordingly, when the flow rate Q of the blowby gas is large, it is possible to suppress that the flow velocity of the blowby gas flowing in each part in the separator chamber 12 becomes too high. For this reason, the oil separation ability in the labyrinth portion 22 and the impactor portion 24 can be appropriately exhibited even at a large flow rate. Furthermore, by increasing the area of the flow path of each part in the separator chamber 12 as described above when the flow rate is large, it is possible to suppress an increase in pressure loss (passage resistance) of each part in the separator chamber 12. For this reason, according to the control of the present embodiment, the pressure does not decrease the portion through which the blowby gas passes in the separator chamber 12 at a large flow rate (without causing a decrease in the oil separation capability due to the reduction of the portion). An increase in loss can be suppressed.

  As described above, according to the internal combustion engine 1 including the oil separator 10 according to the present embodiment, high oil separation ability can be exhibited while suppressing increase in pressure loss in a wide flow rate range of blowby gas.

Second Embodiment
Second Embodiment A second embodiment of the present invention will now be described with reference to FIG.

1. Configuration of Internal Combustion Engine According to Embodiment 2 FIG. 4 is a diagram for illustrating the configuration of the main part of an internal combustion engine 2 according to Embodiment 2 of the present invention. In FIG. 4, the same elements as the elements shown in FIG. 1 will be assigned the same reference numerals, and the description thereof will be omitted or simplified.

1-1. Similarity with Configuration According to First Embodiment The internal combustion engine 2 of the present embodiment is provided with an oil separator 70 as shown in FIG. 4. The oil separator 70 has a separator chamber 72. The separator chamber 72 includes an upper inner wall 74 and a lower inner wall 76 as a pair of inner walls opposed to each other.

  In the separator chamber 72, a labyrinth portion 78 and an impactor portion 80 are provided. The labyrinth portion 78 is vertically upward from the plurality of upper partition plates 82 (two by way of example) formed to extend from the upper inner wall 74 downward in the inclination direction with respect to the vertical direction, and from the lower inner wall 76 A plurality of (three by way of example) lower partition plates 84 formed to extend toward the lower side are provided.

  Further, the impactor unit 80 includes an impactor nozzle 86, an impactor wall 88, and a pair of upper partition plates 90 and lower partition plates 92 that constitute the impactor nozzle 86. As shown in FIG. 4, these partition plates 90, 92 extend in the direction of inclination relative to the vertical direction in the separator chamber 72 so as to close the flow path of the blowby gas. The impactor nozzle 86 is formed at the center of the pair of partition plates 90, 92.

1-2. Differences to the Configuration According to Embodiment 1 In Embodiment 1 described above, “a part of the lower inner wall 20” is vertically displaced by the actuator 50 in the vertical direction. On the other hand, in the present embodiment, the "part of the lower inner wall 76" (the part shown as "movable part" in FIG. 4) is displaced in the horizontal direction (in the left-right direction of the drawing) by the actuator 100.

  More specifically, according to the configuration of the present embodiment, the actuator 100 displaces the part (movable part) of the lower inner wall 76 horizontally along the horizontal direction, accordingly, the lower partition The plate 84 is displaced to the left and right. As a result, the minimum passage cross-sectional area B between the pair of partition plates 82, 84 adjacent to each other among the plurality of partition plates 82, 84 is changed. If the minimum passage sectional area B can be changed according to the displacement of the above-mentioned part of the lower inner wall 76 by the actuator 100, the upper partition plate 82 of the labyrinth portion 78 extends downward along the vertical direction. Conversely, the lower partition 84 may be formed to extend in a direction inclined from the vertical direction.

  Further, by displacing the part of the lower inner wall 76 horizontally in the horizontal direction by the actuator 100, the lower partition plate 92 is displaced left and right accordingly. As described above, since the upper partition plate 90 and the lower partition plate 92 for forming the impactor nozzle 86 are inclined with respect to the vertical direction, the opening area of the impactor nozzle 86 is increased by such left and right displacement. Be changed.

2. Control of Actuator According to Second Embodiment In the present embodiment, the ECU 60 controls the minimum passage cross sectional area B of the labyrinth portion 78 and the opening area of the impactor nozzle 86 according to the flow rate Q of the blowby gas flowing into the separator chamber 72. The actuator 100 is controlled to be increased or decreased.

2-1. Control at Small Flow Rate More specifically, the ECU 60 controls the actuator 100 so that the above-mentioned part of the lower inner wall 76 is displaced to the left in the horizontal direction, as shown by the arrow in FIG. Do. As a result, when the flow rate is small, the minimum passage cross-sectional area B of the labyrinth portion 78 is reduced. In addition, when the flow rate is small, the passage cross-sectional area of the opening area of the impactor nozzle 86 is also reduced.

2-2. Control at Large Flow Rate On the other hand, when the flow rate is large, the ECU 60 controls the actuator 100 so that the part of the lower inner wall 76 is displaced to the right in the horizontal direction, as shown by the arrow in FIG. As a result, at the time of high flow rate, the minimum passage cross-sectional area B of the labyrinth portion 78 is increased as compared to the time of low flow rate. Further, at the large flow rate, the opening area of the impactor nozzle 86 is also increased as compared to the small flow rate.

3. Effect of Control of Actuator According to Second Embodiment According to the control of the actuator 100 according to the present embodiment described above, regarding the labyrinth portion 78, in place of the control of the passage cross-sectional area A of the first embodiment, the minimum passage Cross sectional area B is changed. More specifically, at high flow rates, the minimum passage cross-sectional area B is increased as compared to low flow rates. The resistance of a certain passage is greatly contributed by the portion in the passage where the passage cross-sectional area is minimum. For this reason, the increase of the minimum passage cross-sectional area B can suppress the increase of the passage resistance (pressure loss) at high flow rate. Further, the change of the opening area of the impactor nozzle 86 according to the flow rate Q of the blowby gas is the same as that of the first embodiment. Also by the internal combustion engine 2 provided with the oil separator 70 according to the present embodiment, high oil separation ability can be exhibited while suppressing increase in pressure loss in a wide flow rate range of blowby gas.

4. Modification of Embodiment 2 4-1. In the second embodiment described above, the actuator 100 is controlled such that a portion of the lower inner wall 76 is displaced laterally along the horizontal direction. On the other hand, the actuator may be controlled so that the upper inner wall is displaced laterally along the horizontal direction, for example, as shown in the following FIG.

  FIG. 5 is a diagram for describing a configuration of a first modified example of the internal combustion engine 2 according to Embodiment 2 of the present invention. The separator chamber 112 of the oil separator 110 shown in FIG. 5 includes an upper inner wall 114 and a lower inner wall 116 as a pair of inner walls facing each other. In the configuration shown in FIG. 5, a plurality of (two, as an example) upper partition plates 120 of the labyrinth portion 118 and an upper partition plate 124 constituting the impactor nozzle 122 are integrally formed on the upper inner wall 114. There is. In addition, in the configuration shown in FIG. 5, the ECU 60 controls the actuator 130 such that the movable portion (that is, the portion including the upper inner wall 114) shown in FIG. 5 is displaced to the left and right in the horizontal direction.

4-2. Example in which the upper inner wall and the lower inner wall are movable portions Also, for example, as shown in the following FIG. 6, both the upper inner wall and the lower inner wall are displaced horizontally along the horizontal direction. The actuator may be controlled.

  FIG. 6 is a diagram for illustrating the configuration of a second modification of the internal combustion engine 2 according to the second embodiment of the present invention. The separator chamber 142 of the oil separator 140 shown in FIG. 6 includes an upper inner wall 144 and a lower inner wall 146 as a pair of inner walls facing each other. In the configuration shown in FIG. 6, a plurality of (two as an example) upper partition plates 150 of the labyrinth portion 148 and an upper partition plate 154 constituting the impactor nozzle 152 are integrally formed on the upper inner wall 144. There is. Further, on the lower inner wall 146, a plurality of (for example, three) lower partition plates 156 of the labyrinth portion 148 and a lower partition plate 158 constituting the impactor nozzle 152 are integrally formed.

  Furthermore, in the configuration shown in FIG. 6, the ECU 60 displaces the two movable portions shown in FIG. 6 (that is, a part of the upper inner wall 144 and a part of the lower inner wall 146) horizontally and in the same direction. Control the actuator 160 so that More specifically, as shown in FIG. 6A, when the flow rate is small, the part of the upper inner wall 144 is displaced leftward in the horizontal direction, and the part of the lower inner wall 146 is displaced leftward in the horizontal direction. Displace. As a result, the minimum passage sectional area B of the labyrinth portion 148, the passage sectional area of the opening area of the impactor nozzle 152, and the passage sectional area of the inlet 14 of the separator chamber 142 are reduced. On the other hand, as shown in FIG. 6B, when the flow rate is large, the part of the upper inner wall 144 is displaced to the right in the horizontal direction, and the part of the lower inner wall 146 is displaced to the right in the horizontal direction . As a result, the minimum passage cross-sectional area B of the labyrinth portion 148, the passage cross-sectional area of the opening area of the impactor nozzle 152, and the passage cross-sectional area of the inlet 14 of the separator chamber 142 are increased. Note that, unlike this example, the actuator 160 may be controlled such that these two movable parts are displaced in the horizontal direction and in the opposite direction to each other.

4-3. Variation of passage cross-sectional area A and minimum passage cross-sectional area B Further, by combining the configuration of the first embodiment described above with the configuration of the second embodiment, when the flow rate Q of the blowby gas is large, the case of the small flow rate Q In comparison, the actuator may be controlled by the ECU 60 such that both the passage cross sectional area A and the minimum passage cross sectional area B increase.

Other embodiments.
In the first and second embodiments described above, the passage cross sectional area A or the minimum passage cross sectional area B of the labyrinth portion 22 or the like, the opening area of the impactor nozzle 32 or the like, and the inlet 14 The actuator 50 or the like is controlled such that the passage cross-sectional area of the valve 50 is increased or decreased. In addition to such control, at least one or both of the passage cross-sectional area A and the minimum passage cross-sectional area B of the area of each of these parts increase or decrease according to the oil mist particle size distribution estimated based on engine operating conditions It may be done. The oil mist particle size distribution can be estimated, for example, by the following method. That is, the relationship between the engine operating conditions (more specifically, the engine rotational speed, the coolant temperature and the fuel injection amount (in-cylinder pressure)) and the particle size distribution of the oil mist is obtained in advance by experiments etc. The relationship is stored in the ECU 60 as a map. Thereby, the ECU 60 can estimate the oil mist particle size distribution according to the engine operating condition by referring to such a map during operation of the internal combustion engine 1 and the like.

1, 2 internal combustion engines 10, 70, 110, 140 oil separators 12, 72, 112, 142 separator chambers 14 inlets 16 outlets 18, 74, 114, 144 upper internal walls 20, 76, 116, 146 lower internal walls 22, 78, 118, 148 Labyrinth portions 24, 80 impactor portions 26, 36, 82, 90, 120, 124, 150, 154 upper partition plates 28, 38, 84, 92, 156, 158 lower partition plates 30 labyrinth passage 32, 86, 122, 152 Impactor nozzle 34, 88 Impactor wall 40 Inlet wall 42 Oil pits 50, 100, 130, 160 Actuator 60 Electronic control unit (ECU)

Claims (1)

An inlet for an oil-containing gas formed longitudinally and provided at one end in the longitudinal direction, an outlet for the oil-containing gas provided at the other end in the longitudinal direction, and a pair of opposing inner walls A separator chamber,
A plurality of partition plates formed to extend from the pair of inner walls toward the center of the separator chamber such that the tips overlap each other when viewed from the longitudinal direction;
An internal combustion engine, comprising: an oil separator having a labyrinth passage formed inside the separator chamber by the plurality of partition plates,
The internal combustion engine is
A passage cross-sectional area between at least one tip of the plurality of partition plates and one of the pair of inner walls facing the tip, and a minimum between a pair of partition plates adjacent to each other among the plurality of partition plates An actuator that makes one or both of the passage sectional areas variable;
When the flow rate of the oil-containing gas flowing into the separator chamber is high, the actuator may be configured to increase one or both of the passage cross-sectional area and the minimum passage cross-sectional area as compared to the case where the flow rate is low. A controller for controlling the
An internal combustion engine further comprising:

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