JP2010248971A - Oil deterioration suppressing device for internal combustion engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To increase an area of the contact of an acid material causing oil deterioration with an alkaline material neutralizing the acid material. <P>SOLUTION: Baffles 9 are arranged in an oil separator 8 so as to be opposed to a blow-by gas flow. The baffles 9 are formed of a porous film containing the alkaline material. An inversion mechanism 31 is provided for inverting directions of the baffles 9. Since the film has porosity and both surfaces of the film are exposed, the substantive area of contact is increased by reacting the acid material with the alkaline materials on both surfaces of the film and the inside thereof. Blow-by gases are evenly applied to both the surfaces of the film by the inversion mechanism 31, thereby extending the service life of the film. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an oil deterioration suppressing device for an internal combustion engine, and more particularly to an apparatus for suppressing oil deterioration of an internal combustion engine using a novel film.

  For example, in an internal combustion engine for automobiles, there is always a demand for suppressing deterioration of oil as lubricating oil, extending the life of the oil, and reducing the frequency of oil replacement. As the oil is used, sludge is gradually mixed, and the oil mixed with this sludge becomes difficult to function sufficiently as a lubricant due to viscosity increase and additive consumption. For this reason, it is necessary to suppress the mixing of sludge into the oil as much as possible.

  Sludge mainly contains olefin and aroma contained in fuel, NOx and SOx contained in blow-by gas or combustion gas, and water, and these main components react with the power of heat and acid to produce a sludge precursor, It is produced via a precursor such as a sludge binder. Sludge is visually a mud or sludge-like substance.

  In particular, an acidic substance produced by a reaction between water generated by dew condensation or the like inside the internal combustion engine and NOx or SOx contained in blow-by gas serves as a catalyst for generating sludge. The mixing of such acidic substances into the oil accelerates the generation of sludge, accelerates the deterioration of the oil, and lowers the functions of the lubricating oil.

  Conventionally, as a countermeasure against this acidic substance, in Patent Document 1, a sludge suppression layer containing an alkaline substance is formed on the surface of a part where oil as a liquid is not always distributed and oil mist as a gas is contacted. Yes. According to this, the said acidic substance can be neutralized with an alkaline substance, and it can suppress that sludge is produced | generated or adhered to the surface of the said site | part by this.

JP 2008-121474 A

  However, in the technique of Patent Document 1, since the sludge suppression layer is exposed and reacts only with the acidic substance on one side, the problem is that the contact area or reaction area between the alkaline substance and the acidic substance increases. Still remains.

  In the technique of Patent Document 1, a solution in which an alkaline substance is dispersed is applied to a target surface (for example, the inner surface of the head cover) to form a sludge suppression layer. Cause an increase. In addition, the target surface often has a complicated shape, and a wide range of coating must be performed due to the insufficient contact area, so that such a problem becomes more prominent.

  Accordingly, the present invention was created in view of the above-described problems, and an object thereof is to provide an oil deterioration suppression device for an internal combustion engine that can increase the contact area of an alkaline substance with an acidic substance and can also suppress the manufacturing cost. It is in.

According to one aspect of the invention,
In an oil deterioration suppressing device for an internal combustion engine having an oil separator for separating oil from blow-by gas,
A baffle plate is disposed on the oil separator so as to oppose the flow of the blow-by gas, and the baffle plate is formed from a porous film containing an alkaline substance, and the flow direction of the blow-by gas or the baffle plate An oil deterioration suppressing device for an internal combustion engine is provided, which is provided with a reversing means for reversing the direction.

  According to this, since the film is porous, the acidic substance and the alkaline substance can be contacted and reacted not only on the exposed surface of the film but also inside thereof. Further, since both surfaces of the film are exposed in the oil separator, the exposed surface area can be doubled as compared with the case of Patent Document 1. Therefore, it is possible to greatly increase the contact area of the alkaline substance with respect to the acidic substance and greatly promote the neutralization reaction. In addition, since a film as a separate part is disposed instead of directly coating on the target surface, masking at the time of coating is unnecessary, and the manufacturing cost can be suppressed.

  Further, since the reversing means for reversing the flow direction of the blow-by gas or the direction of the baffle plate is provided, the blow-by gas can be uniformly applied to both surfaces of the film, and the life of the film can be extended.

  Preferably, the inversion means integrates the blowby gas flow rate or time when the baffle plate is in a predetermined direction and the blowby gas is flowing in a predetermined direction, and determines the inversion timing based on the integrated value.

Preferably,
A plurality of the oil separators provided with the baffle plates are provided;
The plurality of oil separators are connected to the throttle valve downstream side of the intake passage via the PCV passage, and are connected to the throttle valve upstream side of the intake passage via the fresh air passage,
The inversion means reverses the flow direction of the blow-by gas,
The reversing means includes a plurality of valves that switch the connection state between each oil separator and the PCV passage and the fresh air passage to reverse the flow directions of blow-by gas and fresh air in each oil separator.

  Preferably, the reversing unit integrates the blowby gas flow rate or the time during which the blowby gas flows for each set of the oil separator and the blowby gas flow direction, and when the currently integrated value exceeds a predetermined value, the integration is performed. Valve control means for controlling the plurality of valves is provided so that another set having a minimum value is realized.

  Preferably, the reversing means reverses the direction of the baffle plate, the baffle plate is made of a flexible belt formed from the film, and the reversing means causes the belt to be moved at a predetermined timing. Is provided with moving means for moving to a predetermined length.

  According to the present invention, it is possible to provide an oil deterioration suppressing device for an internal combustion engine that can increase the contact area of an alkaline substance with respect to an acidic substance and can also suppress the manufacturing cost.

1 is a schematic side view of an internal combustion engine according to an embodiment. It is a schematic plan view of an oil separator. It is a front view of a baffle board, and is a III arrow directional view of FIG. It is a perspective view of a film. It is an enlarged surface view of the film by a scanning electron microscope (SEM). It is an expanded sectional view of the film by a scanning electron microscope (SEM), and has a higher magnification than FIG. It is a circuit diagram which shows the structure of 1st Example. It is a circuit diagram which shows the structure of 2nd Example, and shows the state at the time of partial load. It is a circuit diagram which shows the structure of 2nd Example, and shows the state at the time of full load. It is the schematic which shows the structure of the main valve vicinity. It is a flowchart which shows the routine of valve control in 2nd Example. It is a graph which shows an example of the integrated flow volume of each state E1-E4. It is a graph which shows the change of the integrated flow after valve control execution. It is a schematic side view which shows the structure of 3rd Example. It is a schematic plan view which shows the structure of 4th Example. It is a partial front view of the belt which concerns on 4th Example.

  DESCRIPTION OF EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

  FIG. 1 schematically shows an internal combustion engine according to this embodiment. As shown in the figure, an engine 1 that is an internal combustion engine includes a cylinder block 2, a crankcase 4 provided at a lower portion of the cylinder block 2, a cylinder head 5 attached to an upper portion of the cylinder block 2, and an upper portion of the cylinder head 5. The head cover 6 is attached to the upper side of the crankcase 4 and the oil pan 7 is attached to the bottom of the crankcase 4. A timing chain cover 3 is attached to the sides of the cylinder block 2, the cylinder head 5, and the crankcase 4.

  The engine 1 also includes an intake passage 10, and the downstream end of the intake passage 10 is connected to an intake port (not shown) inside the cylinder head 5. An air filter (not shown) is provided at the upstream end of the intake passage 10. A throttle valve 11 and a surge tank 13 are provided in an intermediate portion of the intake passage 10 to distribute intake air from the surge tank 13 to intake ports of each cylinder of the engine 1 which is a multi-cylinder internal combustion engine.

  The engine of the present embodiment is an automotive spark ignition internal combustion engine (specifically, a gasoline engine), and has a fuel injection injector and a spark plug (both not shown) for each cylinder. There is no particular limitation on the number of cylinders, usage, and the like. The engine may be a compression ignition type internal combustion engine (specifically, a diesel engine).

  An oil separator 8 is formed in the head cover 6 as a space for separating oil from blow-by gas. The oil separator 8 extends in the engine crankshaft direction (left-right direction in the figure), and blow-by gas flows along the longitudinal direction. The oil separator 8 is connected to the intake passage 10 on the downstream side of the throttle valve 11 via the PCV passage 14. PCV is an abbreviation for Positive Crankcase Ventilation. A PCV valve 15 is provided in the PCV passage 14, and the opening degree of the PCV valve 15 is adjusted according to the intake negative pressure or the load.

  The oil separator 8 is connected to an intake passage 10 on the upstream side of the throttle valve 11 via a fresh air passage 17. The connection state of the oil separator 8, the PCV passage 14, and the fresh air passage 17 is not actually a connection state as shown in FIG. This point will become clear later.

  As shown by the arrows in the figure, the blow-by gas in the crankcase 4 is introduced into the oil separator 8 through a predetermined passage. Then, it flows in the oil separator 8 in the longitudinal direction toward the PCV passage 14 side (right side in the figure), passes through the PCV passage 14 and is circulated to the intake passage 10. Finally, it is burned in the cylinder.

  The PCV valve 15 is opened at the time of partial load and full load of the engine, and allows the flow or recirculation of the blow-by gas described above. On the other hand, fresh air is introduced into the oil separator 8 through the fresh air passage 17 at the time of partial load, and ventilation is performed, but the flow direction is reversed at full load, and blow-by gas is sucked from the oil separator 8 through the fresh air passage 17. It is returned to the passage 10.

  As shown in FIG. 2, two oil separators 8 are provided separately from each other. One is referred to as a first separator and the other is referred to as a second separator. The first separator A and the second separator B have the same configuration, each extending in the direction of the crankshaft of the engine and parallel to each other. First and second ports A1, B1 and A2, B2 that allow gas to enter and exit are provided at one end and the other end in the longitudinal direction of the first separator A and the second separator B, respectively.

  As shown in FIGS. 1 and 2, a plurality (five in the illustrated example) of baffle plates 9 are erected in the oil separator 8. The baffle plate 9 is disposed so that the front and back surfaces thereof face the longitudinal direction of the oil separator 8 so as to oppose the flow of blow-by gas in the oil separator 8. The baffle plate 9 is disposed perpendicular to the longitudinal direction of the oil separator 8. Further, the baffle plates 9 are arranged in a zigzag pattern along the longitudinal direction of the oil separator 8 as shown in FIG. The baffle plate 9 is fixed to the bottom surface of the oil separator 8. When blow-by gas flows along the longitudinal direction of the oil separator 8, the blow-by gas collides with the baffle plate 9 and is deflected. At this time, oil contained in the blow-by gas adheres to the baffle plate 9. This separates the oil from the blowby gas.

  In particular, these baffle plates 9 are formed of a film for suppressing oil deterioration. That is, as shown in FIG. 3, the baffle plate 9 holds the peripheral portion of the film 20 with a frame-like frame 21 made of a metal such as aluminum and maintains the film 20 in a stretched state. This film 20 is porous containing an alkaline substance, and neutralizes acidic substances contained in the attached oil and blow-by gas when blow-by gas collides or comes into contact. Although the baffle plate 9 of the present embodiment is a quadrangle, the shape is arbitrary.

  Details of the film will be described here. As shown in FIG. 4, the film 20 is in the form of a flat thin plate or thin film in the illustrated example, and its thickness can be adjusted, but is about 0.1 to 1 mm, for example. As shown in FIGS. 5 and 6, the film is porous having a large number of pores inside. The film 20 includes at least an alkaline substance, and examples of the alkaline substance include calcium carbonate, calcium hydroxide, calcium oxide, potassium hydroxide, barium hydroxide, sodium carbonate, and sodium bicarbonate, but other substances can be used. . The film 20 contains a resin for the purpose of bonding alkaline substances together or increasing the strength of the film itself. The resin may be either a thermosetting resin or a thermoplastic resin, and examples thereof include polyurethane, silicon, modified silicon, acrylic, fluororesin, polyvinyl chloride, epoxy, polyethylene, and polypropylene, but other resins may also be used. It can be used. The resin and the alkaline substance are physically attached by intermolecular forces and are not chemically bonded.

  The film 20 has flexibility or flexibility and can be bent relatively freely. Moreover, it can be cut into any size and shape. However, if the concentration (or mixing ratio) or thickness of the resin is set to a certain level or more, a structure having no flexibility or flexibility can be obtained.

  Here, the film production method will be described. First, a resin such as polyurethane is diluted with a water-soluble organic solvent such as N, N-dimethylformamide. At this time, a surfactant may be added to adjust the size of the pores of the film. Next, an alkaline substance such as calcium carbonate is mixed with the diluted resin to form a mixture, and the mixture is thoroughly stirred.

  Next, the mixture thus formed is applied to the surface of the mold to form a coating film. When a flat film as shown in FIG. 4 is produced, the mold may be a simple flat plate, for example, a flat glass plate. The thickness of the coating can be adjusted.

  Next, the coating film is washed with water to remove the organic solvent from the coating film. Specifically, the coating film is first immersed in water together with the mold, and the organic solvent is desorbed from the coating film. During the detachment, the path through which the organic solvent passes becomes a foamed shape, so that the foamed portion becomes a pore in the final product. The organic solvent is water-soluble and can be easily removed. Heating is not necessary. Thereafter, it is preferable that the coating film is removed from the mold and washed again with hot water or water to completely remove the organic solvent on the surface in contact with the mold. Then, the coating film is dried. Thereby, the film as the final product is completed.

  As is clear from this manufacturing method, a film having an arbitrary shape can be produced by changing the shape of the mold.

  The higher the concentration of the alkaline substance in the film as the final product, the higher the neutralization effect. However, if the concentration of the alkaline substance is too high, the film becomes so brittle that it can no longer hold its own shape, and it may even collapse. Regarding the balance between the neutralizing action and the shape retention, according to the test by the present inventors, it was found that the shape retention can be secured if the calcium carbonate concentration is about 70 wt% or less in the case of a combination of calcium carbonate and polyurethane. is doing. Therefore, the concentration of the alkaline substance in the film is preferably about 70 wt% or less.

In the above engine, acidic substances such as nitric acid HNO ₃ and sulfuric acid H ₂ SO ₄ are produced by the reaction of NOx and SOx contained in the blowby gas with water generated by condensation or contained in the blowby gas. This acidic substance induces sludge and oxidizes and degrades the oil. In particular, the oil separator 8 in the head cover 6 is likely to generate dew condensation water due to a temperature difference from the outside air, and an acid substance is likely to be generated. Further, since the oil separator 8 is not a part where oil is actively flowed, once sludge is formed, it is not washed away with oil and tends to adhere and accumulate.

  However, according to the present embodiment, the acidic substance can be neutralized by reacting with the alkaline substance contained in the film 20, thereby greatly suppressing the generation of sludge and the deterioration of oil.

  In particular, since the film 20 is porous and has a large number of pores inside, and the internal pores are connected, the reaction can be advanced in the thickness direction of the film 20 and not only the surface of the film 20 The contact and reaction of an acidic substance and an alkaline substance can be caused also in the inside. Therefore, the contact area and reaction area per unit area of the film can be increased, and the neutralization reaction can be greatly promoted.

  Moreover, since both the front surface and the back surface of the film 20 are exposed in the oil separator 8, the exposed surface area can be doubled as compared with the case where an alkaline substance is applied to the target surface as in Patent Document 1. That is, in Patent Document 1, one side of the sludge suppression layer that contacts the target surface is not exposed, and only the other side is exposed, but in this embodiment, both sides are exposed. Therefore, this embodiment can obtain a neutralization effect twice as much as that of Patent Document 1, and this can also promote the neutralization reaction.

  Furthermore, since the film 20 as a separate component is not directly applied to the target surface but is installed in the space, masking at the time of application is unnecessary, and the manufacturing cost can be suppressed. In addition, since the existing baffle plate can be replaced with one produced from the film 20, it is not necessary to increase the number of parts, and the manufacturing cost can be suppressed.

  Although the alkaline substance contained in the film is gradually consumed and disappears by the reaction with the acidic substance over time, the resin and the alkaline substance are physically attached as described above, Since the resin is not bonded, the resin is not affected during and after consumption of the alkaline substance. Thus, the strength of the film can still be maintained after consumption of the alkaline substance. It is also possible to replace the baffle plate 9 after consumption of the alkaline substance.

  By the way, when the blow-by gas flows in one direction (for example, from the left side to the right side in FIG. 2) in the oil separator 8, the other side of the film 20 faces the other side (for example, the left side in FIG. 2). More oil (for example, the right side of FIG. 2) adheres. The acidic substance in the oil is neutralized with the alkaline substance in the film 20, but if this state continues, the alkaline substance disappears quickly only on one side where blowby gas is hit, and the neutralizing action is lost. End up. Moreover, if oil adheres to the said one surface after this happens, since the neutralizing action is already weak, there is a possibility that the adhered oil will become sludge.

  Therefore, in order to solve such a problem, in this embodiment, a reversing unit is provided for reversing the flow direction of the blow-by gas or the direction of the baffle plate at every predetermined timing. This will be described below.

[First embodiment]
FIG. 7 shows the configuration of the first embodiment of the inverting means. The first separator A, the second separator B, the crankcase 4, the PCV passage 14, the PCV valve 15, and the fresh air passage 17 are abbreviated.

  This inversion means reverses the flow direction of blow-by gas. The reversing means switches a plurality of valves VA1, VA2 for switching the connection state between the oil separators A, B and the PCV passage 14 and the fresh air passage 17 to reverse the flow directions of the blow-by gas and fresh air in each oil separator. , VB1 and VB2. These valves are three-way solenoid valves, and are controlled by a control device (hereinafter referred to as ECU) (not shown) as valve control means.

  7A to 7D show different states of the same configuration, particularly different valve positions. The positions of the valves VA1, VA2, VB1, and VB2 in FIGS. 7A and 7B are the same. However, (A) shows the state when the engine is partially loaded, and (B) shows the state when the engine is fully loaded. Hereinafter, the state of the valve position shown in FIGS. 4A and 4B is referred to as a first mode.

  On the other hand, the positions of the valves VA1, VA2, VB1, and VB2 in FIGS. 7C and 7D are the same, but the positions of the valves in FIGS. 7A and 7B are different. (C) shows the state when the engine is partially loaded, and (D) shows the state when the engine is fully loaded. Hereinafter, the state of the valve position shown in FIGS. 7C and 7D is referred to as a second mode.

  Here, the partial load and full load of the engine refer to the following states, for example. For example, assuming that the opening of the throttle valve has an opening of 0/8 when idling, that is, fully closed, and an opening of 8/8 when fully opened, the opening of the throttle valve is 1/8 to 6 The time when it is about / 8, and the time of full load means the time when the opening degree of the throttle valve is about 6/8 to 8/8.

  As shown in FIG. 7A, the first valve VA1 is connected to the first port A1 of the first separator A, the second valve VA2 is connected to the second port A2 of the first separator A, and the second A third valve VB1 is connected to the first port B1 of the separator B, and a fourth valve VB2 is connected to the second port B2 of the second separator B.

  The first valve VA1 and the crankcase 4 are connected by a passage PA11, and the first valve VA1 and the fresh air passage 17 are connected by a passage PA12.

  The second valve VA2 and the crankcase 4 are connected by a passage PA21, and the second valve VA2 and the fresh air passage 17 are connected by a passage PA22.

  The third valve VB1 and the crankcase 4 are connected by a passage PB11, and the third valve VB1 and the PCV passage 14 are connected by a passage PB12.

  The fourth valve VB2 and the crankcase 4 are connected by a passage PB21, and the fourth valve VB2 and the PCV passage 14 are connected by a passage PB22.

In the first mode shown in FIGS. 7 (A) and 7 (B), the ECU controls each valve to a position where the following state is obtained.
(I) The first valve VA1 connects the first port A1 of the first separator A and the passage PA11.
(Ii) The second valve VA2 connects the second port A2 of the first separator A and the passage PA22.
(Iii) The third valve VB1 connects the first port B1 of the second separator B and the passage PB11.
(Iv) The fourth valve VB2 connects the second port B2 of the second separator B and the passage PB22.

  Then, at the partial load shown in FIG. 7A, the blow-by gas discharged from the crankcase 4 flows through the second separator B from the left side to the right side (this is referred to as the first direction), and then the PCV passage 14 Discharged from. In the process of passing through the second separator B, the acidic substance in the blowby gas and the oil mist contained therein hits the left side of the film 20 of the baffle plate 9 (this is referred to as the first side), and it contains an alkaline substance. To be summed.

  Then, the fresh air introduced from the fresh air passage 17 flows into the crankcase 4 after flowing through the first separator A from the right side to the left side of the drawing (this is referred to as the second direction). Thereby, the inside of the crankcase 4 is ventilated.

  On the other hand, at the time of full load in the first mode shown in FIG. 7B, in addition to the flow of blow-by gas passing through the second separator B in the first direction, the flow of blow-by gas passing through the first separator A in the first direction. Join. That is, for the latter, blow-by gas discharged from the crankcase 4 is introduced into the first port A1 of the first separator A through the passage PA11, flows through the first separator A in the first direction, and then passes through the passage PA22. It is discharged from the fresh air passage 17. At this time, it will be apparent that the neutralization action similar to that of the second separator B occurs also in the first separator A.

On the other hand, in the second mode shown in FIGS. 7C and 7D, the ECU controls each valve to a position where the valve is in the following state.
(I) The first valve VA1 connects the first port A1 of the first separator A and the passage PA12.
(Ii) The second valve VA2 connects the second port A2 of the first separator A and the passage PA21.
(Iii) The third valve VB1 connects the first port B1 of the second separator B and the passage PB12.
(Iv) The fourth valve VB2 connects the second port B2 of the second separator B and the passage PB21.

  Then, the flow direction of fresh air or blow-by gas in the first separator A and the flow direction of blow-by gas in the second separator B are reversed, that is, reversed.

  First, at the partial load shown in FIG. 7C, blow-by gas discharged from the crankcase 4 flows through the second separator B from the right side to the left side (in the second direction), and then is discharged from the PCV passage 14. The In the process of passing through the second separator B, the acidic substance in the blow-by gas and the oil mist contained therein hits the right side of the film 20 of the baffle plate 9 (this is referred to as the second side), and the inside is an alkaline substance. To be summed. Then, the fresh air introduced from the fresh air passage 17 flows into the crankcase 4 after flowing through the first separator A from the left side to the right side (in the second direction).

  On the other hand, at the full load shown in FIG. 7D, in addition to the flow of blow-by gas passing through the second separator B in the second direction, the flow of blow-by gas passing through the first separator A in the second direction is also added. That is, for the latter, the blow-by gas discharged from the crankcase 4 is introduced into the second port A2 of the first separator A through the passage PA21, flows through the first separator A in the second direction, and then passes through the passage PA12. It is discharged from the fresh air passage 17.

  Thus, since the flow direction of the blow-by gas in the oil separator can be reversed, the blow-by gas can be applied to both surfaces of the film 20, and the alkaline substances on both surfaces can be effectively utilized. And it becomes possible to prevent early disappearance of the alkaline substance on only one side of the film 20 and to prolong the life of the film 20.

  Here, the timing for reversing the flow direction of the blow-by gas is preferably such that the alkaline substance on both sides of the film 20 disappears evenly. This point will be described in detail later.

  In the same way, it is also preferable to reverse the direction of the baffle plate 9, that is, the film 20, while keeping the flow direction of the blow-by gas constant. This point will also be described in detail later.

[Second Embodiment]
In the first embodiment, particularly in a partial load that is frequently used in an automobile engine, only fresh air passes through the first separator A, and the film 20 deteriorates faster in the second separator B than in the first separator A. There is a problem of doing. Therefore, at the time of partial load, it is possible to make the blow-by gas circulate through both the first separator A and the second separator B and to reverse the flow direction so that the film 20 of both separators and both surfaces thereof can be effectively utilized. This is an example.

  FIG. 8 shows the configuration of the second embodiment of the inverting means, and shows the state at the time of partial load. FIG. 9 shows the state of the second embodiment at full load. The position of each valve is the same during partial load and full load.

  As shown in FIG. 8, the circuit configuration of the second embodiment is substantially the same as that of the first embodiment, but differs from the first embodiment in the following points. That is, a main valve VC connected to both passages is provided in the middle of the PCV passage 14 branched from the branch point C1 and the fresh air passage 17 branched from the branch point C2. The main valve VC is a four-way solenoid valve and is controlled by the ECU.

  As shown in detail in FIG. 10, the main valve VC reaches the first portion 14A of the PCV passage 14 reaching the branch point C1, the second portion 14B of the PCV passage 14 leading to the intake passage 10, and the branch point C2. A first portion 17A of the fresh air passage 17 and a second portion 17B of the fresh air passage 17 reaching the intake passage 10 are connected. The main valve VC includes a rotary valve body 25, and the valve body 25 can be switched between a first position indicated by a solid line in the drawing and a second position indicated by a virtual line in the drawing. The valve body is not limited to a rotary type, and may be a spool type or the like.

  When the main valve VC is in the first position, the first portion 14A and the second portion 14B of the PCV passage 14 are connected, and the first portion 17A and the second portion 17B of the fresh air passage 17 are connected. On the other hand, when the main valve VC is in the second position, the first portion 17A of the fresh air passage 17 and the second portion 14B of the PCV passage 14 are connected, and the first portion 14A of the PCV passage 14 and the fresh air passage 17 are connected. The second portion 17B is connected.

  In the first mode during partial load shown in FIG. 8A, the positions of the first valve VA1 to the fourth valve VB2 are the same as in the first mode of the first embodiment. The main valve VC is controlled to the first position. Thereby, the flow of blow-by gas and fresh air becomes the same as in the first mode at the partial load shown in FIG.

  Further, in the third mode at the partial load shown in FIG. 8C, the positions of the first valve VA1 to the fourth valve VB2 are the same as in the second mode of the first embodiment. The main valve VC is controlled to the first position. Thereby, the flow of blow-by gas and fresh air becomes the same as in the second mode at the partial load shown in FIG.

  On the other hand, in the second mode at the partial load shown in FIG. 8B, the positions of the first valve VA1 to the fourth valve VB2 are the same as those in the first mode shown in FIG. The valve VC is controlled to the second position. Thus, in the first separator A and the second separator B, the relationship between the blow-by gas and the fresh air and the flow direction in the first mode are reversed, and in the first separator A, the blow-by gas is changed from the left side to the right side in the figure. In the second separator B, fresh air flows from the right side to the left side (in the second direction).

  Further, in the fourth mode at the partial load shown in FIG. 8D, the positions of the first valve VA1 to the fourth valve VB2 are the same as those in the third mode shown in FIG. The valve VC is controlled to the second position. Thereby, in the first separator A and the second separator B, the relationship between the blow-by gas and the fresh air and the flow direction are reversed from those in the third mode, and in the first separator A, the blow-by gas is changed from the right side to the left side in the figure. In the second separator B, fresh air flows from the left side to the right side (in the first direction).

  In this way, at the time of partial load, blow-by gas can be circulated through the separators A and B, and the flow direction can be reversed, so that the films 20 of both separators and both surfaces thereof can be effectively utilized. And it becomes possible to prolong the lifetime of the film 20 further.

  In addition, at the time of full load shown in FIG. 9, in any mode, the fresh air introduction path at the time of partial load is replaced with the blow-by gas discharge path. The flow direction of fresh air at the time of partial load is reversed or reversed to become the flow direction of blow-by gas. Specific paths and flow directions are as shown in the figure, and detailed description is omitted.

  By the way, in order to prolong the overall life of the film 20, the blow-by gas is applied evenly to both surfaces of the films 20 of the separators A and B. In other words, the valves are switched at such timing. preferable.

  Therefore, in this second embodiment, the ECU executes the following valve control or reversal control.

First, a group of an oil separator through which blow-by gas flows at the time of partial load and a flow direction thereof are divided and defined as follows.
E1: In the first separator A, the blow-by gas flows from the left side to the right side (in the first direction) in FIG. This is realized in the second mode shown in FIG.
E2: In the first separator A, the blow-by gas flows from the right side to the left side (in the second direction) in FIG. This is realized in the fourth mode shown in FIG.
E3: In the second separator B, the blow-by gas flows from the left side to the right side (in the first direction) in FIG. This is realized in the first mode shown in FIG.
E4: A state in which blow-by gas flows from the right side to the left side (in the second direction) in FIG. 8 in the second separator B. This is realized in the third mode shown in FIG.

  Then, the ECU repeatedly executes the routine shown in FIG. 11 every predetermined calculation cycle.

  First, in step S101, the ECU calculates the blow-by gas flow rate of the oil separator in which the blow-by gas flows in the current mode based on the engine operating state, and integrates this. For example, the blow-by gas flow rate in each direction in each oil separator, that is, the blow-by gas flow rate in all cases E1 to E4 regardless of partial load or full load, engine rotation speed and fuel injection amount Is stored in advance in the ECU, and the ECU calculates the current blowby gas flow rate by referring to the map from the current engine speed and fuel injection amount.

  For example, if the current mode is the second mode, the ECU calculates and integrates the blow-by gas flow rate in the state E1 during partial load. In addition, at full load, the ECU calculates and integrates the blowby gas flow rate in the state E3 in addition to the blowby gas flow rate in the state E1 (see FIG. 9B). Calculation and integration are performed individually for each state.

Next, in step S102, the ECU determines whether or not the currently integrated blow-by gas flow rate (integrated flow rate) exceeds a predetermined value, preferably an average value of the integrated flow rates in all states E1 to E4.
That is, for example, if the current mode is the second mode, the ECU integrates the blow-by gas flow rates in the state E1 at the partial load and in the states E1 and E3 at the full load. At the same time, the ECU always calculates an average value of the integrated flow rates in all states E1 to E4. For example, as shown in FIG. 12, when the integrated flow rate in the state E1 exceeds the average value, the determination becomes yes. Conversely, if the integrated flow rate in the state E1 does not exceed the average value, the determination is no.

  If the determination is no, the ECU ends the routine. On the other hand, if the determination is yes, the ECU proceeds to step S103 and selects a mode that realizes a state in which the integrated flow rate is minimized.

  For example, in the case of the example shown in FIG. 12, the integrated flow rate in the state E3 is the minimum. Therefore, the ECU selects a mode that realizes the state E3, that is, the first mode.

  Next, the ECU proceeds to step S104 and switches the valves VC, VA1, VA2, VB1, and VB2 so as to be in the selected mode. For example, in the example shown in FIG. 12, the ECU switches the valves VC, VA1, VA2, VB1, and VB2 so that the first mode is realized. This is the end of the routine.

  As described above, the ECU determines the inversion timing based on the integrated flow rate, and determines the timing at which the currently integrated flow rate exceeds the average value as the inversion timing.

  When the first mode is executed, the integrated flow rate in the state E3 gradually increases. At the same time, when the engine enters the full load operation state, the integrated flow rate in the state E1 also increases (see FIG. 9A). Then, after a while, as shown in FIG. 13, the integrated flow rate in the state E3 or E1 (E1 in the illustrated example) exceeds the average value. At this time, since the integrated flow rate in state E4 is minimum, the third mode for realizing state E4 is newly selected and executed.

  Thus, since blow-by gas can be uniformly applied to both surfaces of the film 20 of each separator A and B, it is possible to prolong the whole lifetime of the film 20.

  In this example, the mode is switched based on the integrated value of the blowby gas flow rate. Alternatively, the mode may be switched based on the integrated value of the time during which the blowby gas is flowing. That is, the integration time of each state E1 to E4 is calculated individually, and when the currently integrated time exceeds the average value of all the integration times, the mode is realized to realize any of the states E1 to E4 with the minimum integration time. Switch.

  It will be apparent that the valve control or reversal control described here can be applied to the first embodiment described above and the embodiments described later.

[Third embodiment]
In the first and second embodiments described above, the baffle plate 9 is fixedly disposed and the flow direction of the blow-by gas is reversed. On the other hand, the third embodiment and the fourth embodiment to be described later are methods for reversing the baffle plate 9 with the flow direction of blow-by gas constant.

  FIG. 14 shows the configuration of the third embodiment. In the oil separator 8 in the head cover 6, blow-by gas is allowed to flow in a fixed direction from the left side to the right side (in the first direction) in the figure, and a plurality of baffle plates 9 are arranged to face the blow-by gas. These baffle plates 9 can rotate around the central axis 30. Specifically, the baffle plates 9 are fixed to the central axis 30 and rotated together with the central axis 30. The central shaft 30 is pivotally supported by the head cover 6 or the cylinder head 5 below (see FIG. 1).

  A link mechanism 31 is provided to rotationally drive the baffle plate 9 or the central shaft 30. The link mechanism 31 includes a drive rod 32 that extends in the longitudinal direction of the oil separator 8 and can reciprocate in the longitudinal direction, and a connection link 33 that connects the drive rod 32 and each central shaft 30. The connecting link 33 is fixed to the central shaft 30 and is rotatably connected to the drive rod 32. Thus, a reversing mechanism for reversing the baffle plate 9 is formed.

  The drive rod 32 is reciprocated by an actuator (not shown). This actuator is controlled by the ECU.

  When the drive rod 32 is moved to the right side of the drawing (in the first direction) by the actuator from the state shown in (A) by a predetermined distance, as shown in (B), all the baffle plates 9 are simultaneously counterclockwise about It is rotated 90 ° and inverted. Thereby, the surface of the baffle plate 9 which hits blow-by gas is reversed from the left surface (first surface) to the right surface (second surface) in (A). In this way, by reversing the baffle plate 9 at every predetermined timing, both sides of the baffle plate 9 can be effectively used to extend the life of the film.

  Such a reversing mechanism is not limited to this example, and a mechanism using a gear or the like is also possible. In the illustrated example, the baffle plate 9 is inclined with respect to the vertical direction before and after inversion, but may be arranged along the vertical direction. The inversion angle is not limited to about 90 °. In short, the surface that hits the blow-by gas before and after reversal may be changed, and such a change is called reversal.

[Fourth embodiment]
FIG. 15 shows the configuration of the fourth embodiment. In the illustrated example, the first separator A and the second separator which are independent from each other are disposed adjacent to each other, but may be disposed apart from each other. Of course, there may be only one oil separator. A common belt 40 formed from the film 20 is disposed on the separators A and B, and the belt 40 forms the baffle plate 9 in each separator. The belt 40 or the film 20 is flexible and can be bent. Reference numeral 43 denotes a belt guide.

  As shown in FIG. 16, the belt 40 is provided with a plurality of holes 41 along the longitudinal direction thereof, so that the pressure loss in each separator is not excessive.

  The belt 40 is wound around and supported by a plurality of rollers 42 so that the path is symmetrical between the first separator A and the second separator. The belt 40 is reversed a predetermined number of times in each separator so that both the first surface and the second surface face each other in a constant flow direction of blow-by gas. In the illustrated example, the belt 40 is inverted five times within each separator.

  One or several of the plurality of rollers 42 are drive rollers 42A driven by a motor (not shown), and the rest are driven rollers. The motor and thus the driving roller 42A are controlled by the ECU.

  The ECU rotates the driving roller 42A by a predetermined angle (for example, 360 °) every predetermined time (for example, every 10 hours), and moves the belt 40 by a predetermined length. As a result, the position of the belt 40 changes one after another, and the surface of the belt 40 or the film 20 that hits the blow-by gas changes. In this way, the first surface and the second surface of the belt 40 can be equally applied to the blow-by gas, and the film 20 can be effectively used to prolong the life of the film.

  As mentioned above, although preferred embodiment of this invention was described, this invention can also take embodiment other than the above. For example, in the first to third embodiments, the baffle plate may be formed using a hard film that is not flexible. Such a film can be produced by increasing the resin concentration, increasing the thickness, or inserting a reinforcing member. Further, the oil separator may be formed at a site other than the head cover. It is possible to have one baffle.

  The embodiment of the present invention is not limited to the above-described embodiment, and includes all modifications, applications, and equivalents included in the concept of the present invention defined by the claims. Therefore, the present invention should not be construed as being limited, and can be applied to any other technique belonging to the scope of the idea of the present invention.

1 Engine 6 Head cover 8 Oil separator 9 Baffle plate 10 Intake passage 11 Throttle valve 14 PCV passage 17 Fresh air passage 20 Film 40 Belt A First separator B Second separator VA1, VA2, VB1, VB2 Valve VC Main valve

Claims (5)

In an oil deterioration suppressing device for an internal combustion engine having an oil separator for separating oil from blow-by gas,
A baffle plate is disposed on the oil separator so as to oppose the flow of the blow-by gas, and the baffle plate is formed from a porous film containing an alkaline substance, and the flow direction of the blow-by gas or the baffle plate An oil deterioration suppressing device for an internal combustion engine, characterized in that a reversing means for reversing the direction is provided. The inversion means integrates the blowby gas flow rate or time when the baffle plate is in a predetermined direction and the blowby gas is flowing in a predetermined direction, and determines the inversion timing based on the integrated value. The oil deterioration suppressing device for an internal combustion engine according to claim 1. A plurality of the oil separators provided with the baffle plates are provided;
The plurality of oil separators are connected to the throttle valve downstream side of the intake passage via the PCV passage, and are connected to the throttle valve upstream side of the intake passage via the fresh air passage,
The inversion means reverses the flow direction of the blow-by gas,
The reversing means includes a plurality of valves for switching the connection state between each oil separator and the PCV passage and the fresh air passage to reverse the flow direction of blow-by gas and fresh air in each oil separator. The oil deterioration suppressing device for an internal combustion engine according to claim 1 or 2. The reversing means integrates the blowby gas flow rate or the time during which the blowby gas flows for each set of the oil separator and its blowby gas flow direction, and when the currently integrated value exceeds a predetermined value, the integrated value is The oil deterioration suppressing device for an internal combustion engine according to claim 3, further comprising valve control means for controlling the plurality of valves so that another set that is minimized is realized. The reversing means is for reversing the direction of the baffle plate, the baffle plate is formed of a flexible belt formed from the film, and the reversing means is configured to make the belt a predetermined length at a predetermined timing. The oil deterioration suppressing device for an internal combustion engine according to claim 1, further comprising a moving unit that moves.