JP2007064155A - Oil mist treatment device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To inhibit film-shape oil separated from blow-by gas in an oil separator chamber from being scattered again and being taken out of the oil separator chamber with the blow-by gas. <P>SOLUTION: An oil mist treatment device 39 is provided with the oil separator chamber 41 provided in a middle of a blow-by gas passage 36 connecting an intake passage and a crank chamber of an engine and a mist separation part separating oil mist when blow-by gas flows in the oil separator chamber 41. The mist separation part is provided with a restriction wall 45 having a restriction hole 48 and an inertial impingement wall 46 provided on a downstream side of the restriction wall 45. The oil mist treatment device 39 is provided with an air introduction part 52 introducing air to the downstream side of the mist separation part in the oil separator chamber 41. The air introduction part 52 includes an air introducing hole 53 opening roughly opposing to flow of blow-by gas after passing through the mist separation part. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an oil mist processing apparatus that separates oil mist from blow-by gas generated by operation of an internal combustion engine and returns the oil mist to a crank chamber.

  In an internal combustion engine mounted on a vehicle or the like, blow-by gas (unburned mixture or combustion gas) passes through a gap between a piston ring and a piston or a gap between a piston ring and a cylinder wall surface during a compression stroke and an expansion stroke. Leaks from the combustion chamber into the crank chamber. This blow-by gas can cause engine oil to deteriorate. In response to this, a blow-by gas recirculation device is provided in the internal combustion engine so that the blow-by gas is returned to the combustion chamber through the crank chamber, the valve operating chamber, the intake passage, etc., and recombusted.

  However, when the blow-by gas passes through the crank chamber, the engine oil becomes mist and is mixed into the blow-by gas. When blow-by gas containing this mist-like oil (referred to as oil mist) is reburned, the amount of oil consumption increases. Therefore, in order to prevent the oil mist contained in the blow-by gas from being taken away by the flow of the blow-by gas to the intake passage or the like, an oil mist processing device that separates the oil mist from the blow-by gas and returns it to the crank chamber is provided. Is provided.

As such an oil mist processing apparatus, an oil separator chamber is provided in the middle of a blow-by gas passage that connects a crank chamber and an intake passage of an internal combustion engine, and an inertia collision type, labyrinth type mist separating portion is provided in the oil separator chamber. In general, a PCV valve is provided at the gas outlet of the oil separator chamber (see, for example, Patent Documents 1 and 2). According to this oil mist processing apparatus, when the blow-by gas passes through the oil separator chamber, the oil mist contained in the blow-by gas is liquefied by the mist separation unit and separated from the blow-by gas. The separated liquid oil is returned to the crank chamber through the drain passage. The PCV valve adjusts the amount of blow-by gas flowing through the blow-by gas passage according to the engine operating state.
Japanese Patent No. 2662802 JP-A-8-93434

  In the oil mist processing apparatus, as described above, in the process in which the blow-by gas passes through the oil separator chamber, the oil mist contained in the blow-by gas is once liquefied in the mist separation unit and separated from the blow-by gas. Is done. The oil that has been separated and adhered to the inner wall of the oil separator chamber drops, and accumulates at the bottom of the oil separator chamber to form an oil film. However, there is a narrow passage in the mist separation section itself or in the vicinity thereof, for example, a throttle hole in the inertial collision type, and the flow rate of blow-by gas is increased by passing through this portion. Therefore, the oil film-like oil once liquefied and separated as described above is scattered again by the blow-by gas having a high flow velocity. The scattered oil rides on blow-by gas and may be taken out of the oil separator chamber.

  The present invention has been made in view of such circumstances, and an object thereof is to obtain an oil separator chamber in which oil film-like oil once separated from blow-by gas in the oil separator chamber is scattered again and rides on the blow-by gas. It is an object to provide an oil mist processing apparatus capable of suppressing being taken outside.

In the following, means for achieving the above object and its effects are described.
According to the first aspect of the present invention, there is provided an oil separator chamber provided in the middle of a blow-by gas passage connecting the crank chamber and the intake passage of the internal combustion engine, and a mist for separating the oil mist when the blow-by gas flows through the oil separator chamber. In the oil mist processing apparatus including the separation unit, an air introduction unit that introduces air to the downstream side of the mist separation unit in the oil separator chamber is provided.

  According to the above configuration, blow-by gas generated with the operation of the internal combustion engine flows into the crank chamber. The blow-by gas is returned from the crank chamber to the combustion chamber through the blow-by gas passage and the intake passage, and is recombusted.

  The blow-by gas passes through the oil separator chamber in the process of flowing through the blow-by gas passage. During this passage, the oil mist in the blow-by gas is separated by the mist separation part and accumulates at the bottom of the oil separator chamber to form an oil film. The oil film-like oil may be scattered again by the blow-by gas whose flow velocity is increased when passing through the mist separation section, and may be carried outside the oil separator chamber by riding on the blow-by gas.

  In this regard, in the first aspect of the present invention, the air is introduced downstream of the mist separation part in the oil separator chamber by the air introduction part. The introduced air hits the blow-by gas that has passed through the mist separation section, and weakens the flow of the blow-by gas (reduces the flow rate).

  Further, in the oil separator chamber, blow-by gas that sequentially passes through the space upstream of the mist separation unit and the mist separation unit flows into the space downstream of the mist separation unit, and from the air introduction unit. Air flows in. Therefore, the amount of blow-by gas flowing through the mist separation unit is reduced (the flow rate is reduced) as compared with the case where no air introduction unit is provided.

  Since the flow velocity of blow-by gas decreases as air is introduced in this way, the phenomenon that oil once formed into an oil film is scattered again by blow-by gas is suppressed, and as a result, the blow-by gas rides outside the oil separator chamber. The phenomenon of being taken away is less likely to occur.

According to a second aspect of the present invention, in the first aspect of the present invention, the mist separating section includes a throttle wall having a throttle hole and an inertial collision wall provided on the downstream side of the throttle wall. .
According to the above configuration, when the blow-by gas containing oil mist flows through the oil separator chamber, the blow-by gas passes through the throttle hole of the throttle wall and collides with the inertial collision wall. During this collision, the oil mist in the blow-by gas is liquefied, adheres to the inertial collision wall, and is separated from the blow-by gas. The separated oil mist accumulates at the bottom of the oil separator chamber and forms an oil film. Here, when the blow-by gas passes through the throttle hole having a small flow path area, the flow rate of the blow-by gas is likely to be higher than that of an oil mist processing apparatus having a mist separation unit of another type. Therefore, the phenomenon that oil once separated into an oil film is scattered again by blow-by gas is particularly likely to occur. Therefore, providing the air introduction part in the oil mist processing apparatus having such a configuration is particularly effective in suppressing oil re-scattering.

  According to a third aspect of the present invention, in the first or second aspect of the present invention, the air introduction unit has an air introduction port that opens substantially opposite to the flow of blow-by gas after passing through the mist separation unit. Let's prepare.

  According to said structure, the air which flowed in into the oil-separator chamber from the air inlet of the air introduction part flows substantially opposite to the flow of blow-by gas after passing the mist separation part. Therefore, as compared with the case where air flows into the oil separator chamber from a direction other than the above, the flow of blow-by gas can be effectively weakened, and re-scattering of oil in the form of an oil film can be reliably suppressed.

  According to a fourth aspect of the present invention, in the invention according to any one of the first to third aspects, the air introduction section includes an air introduction passage for introducing air into the oil separator chamber, and the air introduction passage. An adjustment valve that adjusts the amount of flowing air is provided.

  According to said structure, in an air introduction part, air passes along an air introduction channel | path and a control valve, and is introduce | transduced into the space downstream from a mist separation part in an oil separator chamber. At this time, the amount of air flowing through the air introduction passage is adjusted by the adjustment valve. By this adjustment, for example, it is possible to avoid a problem that an excessive amount of air flows from the air introduction passage into the space downstream of the mist separation unit.

Hereinafter, an embodiment of the present invention will be described with reference to FIGS. 1 and 2.
As shown in FIG. 1, a vehicle is equipped with a gasoline engine (hereinafter simply referred to as an engine) 11 as an internal combustion engine. The engine 11 includes a cylinder block 13 having a plurality of cylinders (cylinders) 12. A crankcase 14 and an oil pan (not shown) are attached to the lower side of the cylinder block 13, and a cylinder head 15 and a head cover 16 are attached to the upper side. Each cylinder 12 accommodates a piston 17 so as to be capable of reciprocating. Each piston 17 is connected to a crankshaft 19 that is an output shaft of the engine 11 via a connecting rod 18. Therefore, when each piston 17 reciprocates, the movement is converted into a rotational movement by the connecting rod 18 and then transmitted to the crankshaft 19.

  An intake passage 22 and an exhaust passage 23 are connected to the combustion chamber 21 of each cylinder 12, and air outside the engine 11 is taken into the combustion chamber 21 through the intake passage 22, and in the combustion chamber 21. The generated exhaust is discharged to the exhaust passage 23. The cylinder head 15 is provided with an intake valve 24 that opens and closes between the intake passage 22 and the combustion chamber 21 and an exhaust valve 25 that opens and closes between the exhaust passage 23 and the combustion chamber 21 so as to reciprocate. An intake camshaft 26 is provided above the intake valve 24, and an exhaust camshaft 27 is provided above the exhaust valve 25. These intake and exhaust camshafts 26 and 27 are drivingly connected to the crankshaft 19 by pulleys, belts, and the like, and rotate in conjunction with the crankshaft 19. The intake valve 24 is driven by an intake camshaft 26, and the exhaust valve 25 is driven by an exhaust camshaft 27.

  A throttle valve 28 is rotatably provided in the intake passage 22. An actuator 29 such as a motor is drivingly connected to the throttle valve 28. The amount of air flowing through the intake passage 22 varies according to the angle of the throttle valve 28 (throttle opening). The throttle opening is adjusted by driving the actuator 29 in accordance with the amount of depression of the accelerator pedal operated by the driver.

  A fuel injection valve 30 that injects fuel to the combustion chamber 21 side is attached to the intake passage 22 corresponding to each cylinder 12. The fuel injected from each fuel injection valve 30 is mixed with the intake air passing through the intake passage 22 and becomes an air-fuel mixture. The fuel injection valve 30 may inject fuel directly into the combustion chamber 21 (in-cylinder injection).

  A spark plug 31 is attached to the engine 11 corresponding to each cylinder 12. The air-fuel mixture is ignited by the spark discharge of the spark plug 31 and burned. The piston 17 is reciprocated by the high-temperature and high-pressure combustion gas generated at this time, the crankshaft 19 is rotated, and the driving force (output torque) of the engine 11 is obtained.

  In the engine 11, the piston 17 reciprocates twice and the crankshaft 19 rotates twice during a period from when air is sucked into the combustion chamber 21 until combustion gas is discharged, that is, during one cycle. As is well known, this cycle consists of four strokes: an intake stroke, a compression stroke, an expansion stroke, and an exhaust stroke. In each process, the following operations are basically performed.

  In the intake stroke, the exhaust valve 25 is closed, the intake valve 24 is opened, and fuel is injected from the fuel injection valve 30. As the pressure in the combustion chamber 21 (cylinder pressure) decreases as the piston 17 moves down, the air in the intake passage 22 and the fuel are mixed and sucked into the combustion chamber 21. In the compression stroke, the intake valve 24 is closed in addition to the exhaust valve 25. For this reason, as the piston 17 rises, the in-cylinder pressure rises, and the air-fuel mixture is raised and heated.

  In the expansion stroke, ignition is performed by the spark plug 31, and the mixture is ignited and burned. By this combustion, a downward force is applied to the piston 17, and the piston 17 moves downward. In the exhaust stroke, the exhaust valve 25 is opened. For this reason, the exhaust gas generated in the combustion chamber 21 is discharged to the exhaust passage 23 as the piston 17 rises.

  In the engine 11, the gas in the combustion chamber 21 leaks into the crank chamber 33 through the gap between the piston ring 32 and the wall surface of the cylinder 12 or the gap between the piston ring 32 and the piston 17 in the compression stroke and the expansion stroke. To do. The crank chamber 33 is a space in which the crankshaft 19 is accommodated, and more specifically, a space surrounded by the crankcase 14 and the oil pan. The gas is composed of an air-fuel mixture that leaks in the compression stroke, a combustion gas that leaks in the expansion stroke, and the like, which is called blow-by gas, and can cause deterioration in engine oil. The flow rate per unit time of the blow-by gas leaking into the crank chamber 33 is determined by the operating state of the engine 11 such as the rotational speed (engine rotational speed) of the crankshaft 19 and the in-cylinder pressure (combustion pressure).

Therefore, the blow-by gas is returned (returned) to the intake system by the blow-by gas recirculation device and recombusted in the combustion chamber 21.
The blow-by gas recirculation device includes a blow-by gas passage 36 that connects the crank chamber 33 and a downstream of the throttle valve 28 in the intake passage 22, for example, a surge tank 35. In the blow-by gas recirculation device, negative pressure (pressure lower than the atmospheric pressure) generated downstream of the throttle valve 28 acts on the crank chamber 33 through the blow-by gas passage 36. By this intake negative pressure, blow-by gas leaked from the combustion chamber 21 is sucked into the crank chamber 33. In the middle of the blow-by gas passage 36, a PCV valve 37 for adjusting the recirculation amount of the blow-by gas according to the operating state of the engine 11, for example, the engine load or the like is provided.

  Further, the blow-by gas recirculation device includes an outside air introduction passage 38 for introducing air outside the engine 11 (hereinafter referred to as outside air) into the crank chamber 33 in order to reduce the concentration of the blow-by gas in the crank chamber 33. Yes. One end of the outside air introduction passage 38 is connected upstream of the throttle valve 28 in the intake passage 22, and the other end is connected to the crank chamber 33 through the head cover 16, the cylinder head 15, the cylinder block 13, and the like. The outside air is sucked into the crank chamber 33 through the outside air introduction passage 38 by the intake negative pressure.

  As described above, the blow-by gas that is generated by the operation of the engine 11 and leaks from the combustion chamber 21 and the outside air introduced to reduce the concentration of the blow-by gas flow into the crank chamber 33. The mixture of the blowby gas and the outside air is sucked into the intake passage 22 from the crank chamber 33 through the blowby gas passage 36 by the intake negative pressure.

  By the way, when the air-fuel mixture passes through the crank chamber 33 and the like, the engine oil becomes mist (oil mist) and is mixed into the air-fuel mixture. When the air-fuel mixture containing the oil mist is reburned, the oil consumption increases. Therefore, an oil mist processing device 39 is provided to separate and collect the oil mist from the air-fuel mixture.

  As shown in FIG. 2, the oil mist processing device 39 includes an oil separator chamber 41 and a mist separation unit. The oil separator chamber 41 is provided in the head cover 16 (see FIG. 1). A gas inlet 43 is opened at the bottom of the oil separator chamber 41. Further, a gas outlet 44 is opened at a location that is relatively far from the gas inlet 43 in the ceiling of the oil separator chamber 41, and the PCV valve 37 described above is attached to the gas outlet 44. Yes.

  The mist separation unit includes a throttle wall 45 and an inertial collision wall 46 provided between the gas inlet 43 and the gas outlet 44 in the oil separator chamber 41. The lower end surface of the inertial collision wall 46 is spaced upward from the bottom of the oil separator chamber 41. By this separation, a gap 47 through which the air-fuel mixture can flow is formed between the inertial collision wall 46 and the bottom of the oil separator chamber 41. The throttle wall 45 is disposed in the oil separator chamber 41 in the vicinity of the upstream of the inertial collision wall 46. In the diaphragm wall 45, a plurality of throttle holes 48 are formed at locations not corresponding to the gap 47. These throttle holes 48 are for increasing the flow velocity when the air-fuel mixture and the oil mist pass through here, and have a smaller flow path area than other portions in the mist separation section.

  In order to distinguish the space in the oil separator chamber 41, the space upstream of the mist separation part (throttle wall 45) is referred to as “first space S1” and is more than the mist separation part (inertial collision wall 46). The space on the downstream side is referred to as “second space S2”.

  In addition, a drain hole 49 is opened between the throttle wall 45 and the inertial collision wall 46 at the bottom of the oil separator chamber 41. The drain hole 49 communicates with the crank chamber 33 through a drain passage (not shown).

  Further, the oil mist processing device 39 is provided with an air introduction part 52 for introducing air into the mist separation part in the oil separator chamber 41, more precisely, the second space S2 downstream of the inertial collision wall 46. Yes. The air introduction part 52 includes an air introduction port 53, an air introduction passage 54, and a regulating valve 55. The air introduction port 53 is opened at a location corresponding to the gap 47 (substantially opposed location) in the lower portion of the side wall of the oil separator chamber 41. In other words, the air inlet 53 opens substantially opposite to the air-fuel mixture after passing through the mist separation section. The air introduction passage 54 is a passage for introducing air into the second space S2 of the oil separator chamber 41, and its upstream end is connected to the downstream side of the air cleaner 56 of the intake passage 22 (see FIG. 1). The end is connected to the oil separator chamber 41 at the air inlet 53. The adjustment valve 55 is provided in the middle of the passage 54 in order to adjust the amount of air flowing through the air introduction passage 54. As the regulating valve 55, an electromagnetic valve that opens and closes by energization may be used, or a valve that opens and closes mechanically may be used.

Next, the operation of the present embodiment configured as described above will be described.
During the operation of the engine 11, in the intake stroke in which the piston 17 descends and air is sucked into the combustion chamber 21, the pressure (intake pressure) downstream of the throttle valve 28 in the intake passage 22 becomes lower than the atmospheric pressure (negative Pressure). This negative pressure (intake negative pressure) is cranked through the blow-by gas passage 36, the PCV valve 37, the second space S2, the mist separator (inertial collision wall 46, throttle wall 45), the first space S1, the gas inlet 43, and the like. Acts on the chamber 33. For this reason, the blow-by gas that is generated with the operation of the engine 11 and leaked from the combustion chamber 21 is sucked into the crank chamber 33 by the intake negative pressure.

  The intake negative pressure acting on the crank chamber 33 further acts upstream of the throttle valve 28 in the intake passage 22 through the cylinder block 13, the cylinder head 15, the head cover 16, the outside air introduction passage 38, and the like. For this reason, a part of the air flowing through the intake passage 22 is sucked into the crank chamber 33 by the intake negative pressure.

  The air-fuel mixture of the blow-by gas and the outside air sucked into the crank chamber 33 as described above is sucked into the first space S 1 of the oil separator chamber 41 through the gas inlet 43. The sucked air-fuel mixture flows from the first space S1 to the throttle hole 48 of the throttle wall 45 and the inertial collision wall 46 in this order. Since the flow passage area is smaller in the throttle hole 48 than in other places, the flow rate of the air-fuel mixture is increased when passing through the throttle hole 48. When the air-fuel mixture with the increased flow velocity collides with the inertial collision wall 46 vigorously, the oil mist is liquefied and efficiently separated from the air-fuel mixture. The separated liquid oil is dropped after adhering to the inertial collision wall 46 and is accumulated at the bottom of the oil separator chamber 41 to form an oil film.

  The air-fuel mixture from which the oil mist has been separated flows through the gap 47 on the lower side of the inertial collision wall 46 and then flows into the second space S2. At this time, if the air introduction part 52 is not provided, the oil film-like oil 57 is scattered again by the air-fuel mixture whose flow rate is increased when passing through the throttle hole 48, and rides on the air-fuel mixture to the oil separator chamber. There is a risk of being taken outside 41.

  In this regard, in the present embodiment in which the air introduction portion 52 is provided, the intake negative pressure acting on the second space S2 is further supplied to the air cleaner of the intake passage 22 through the air introduction port 53, the air introduction passage 54, the adjustment valve 55, and the like. It acts downstream of 56. For this reason, the clear air after the dust is captured by the air cleaner 56 flows into the second space S <b> 2 in the oil separator chamber 41 through the air introduction passage 54 and the air introduction port 53.

  Here, since the air inlet 53 is opened at a position corresponding to the gap 47 below the inertial collision wall 46 in the lower portion of the side wall of the oil separator chamber 41, the air that has passed through the air inlet 53 is It flows toward the gap 47 along the bottom. That is, the air from the air inlet 53 flows (oppositely flows) substantially opposite to the air-fuel mixture after passing through the gap 47. Then, this air hits the air-fuel mixture after passing through the gap 47 and weakens the flow of the air-fuel mixture (decreases the flow velocity).

  Further, as described above, the air-fuel mixture that has passed through the first space S1 and the mist separation unit in order is sucked into the second space S2, and air is sucked from the air introduction unit 52. For this reason, compared with the case where the air introduction part 52 is not provided, the amount of the air-fuel mixture flowing through the mist separation part decreases (the flow rate decreases).

  Thus, since the flow velocity of the air-fuel mixture decreases with the introduction of air, re-scattering by the air-fuel mixture is suppressed. Along with this, the phenomenon that the resprayed mist-like oil flows on the air-fuel mixture is less likely to occur.

  Then, the air-fuel mixture flowing into the second space S2 through the first space S1 and the mist separator and the air flowing into the second space S2 from the air inlet 53 pass through the PCV valve 37 and the blow-by gas passage 36. The air is drawn into the intake passage 22 and reaches the combustion chamber 21.

  The oil film-like oil 57 which has not been re-scattered by the air-fuel mixture and has accumulated at the bottom of the oil separator chamber 41 flows out of the oil separator chamber 41 through the drain hole 49 and returns to the crank chamber 33 through the drain passage. It is.

  The amount of air flowing through the air introduction passage 54 is adjusted by the adjustment valve 55. By this adjustment, for example, a problem that an excessive amount of air flows into the second space S2 from the air introduction passage 54 is avoided. That is, as the air is introduced from the air introduction passage 54, the amount of air-fuel mixture sucked into the second space S2 and thus the oil separator chamber 41 is reduced. Here, the amount of blow-by gas is determined by the operating state of the engine 11 as described above. On the other hand, since the outside air introduction passage 38 is connected to the intake passage 22, the amount of air sucked into the crank chamber 33 can be easily changed. Therefore, by reducing the amount of outside air sucked into the crank chamber 33 from the outside air introduction passage 38, a reduction in the amount of air-fuel mixture sucked into the oil separator chamber 41 is realized. As the outside air decreases, the ratio (concentration) of the blow-by gas to the air-fuel mixture in the crank chamber 33 increases, and the engine oil tends to deteriorate. On the other hand, in the present embodiment, the adjustment of the air amount using the adjustment valve 55 described above restricts the introduction of an excessive amount of air into the second space S2, and the outside air introduction passage 38 enters the crank chamber 33. A sufficient amount of outside air is ensured. As a result, the phenomenon that the concentration of blow-by gas becomes high and the engine oil is deteriorated is suppressed.

According to the embodiment described in detail above, the following effects can be obtained.
(1) The air introduction part 52 which introduces air into 2nd space S2 downstream from the mist separation part (inertial collision wall 46) in the oil separator chamber 41 is provided. By introducing this air, the flow rate of the air-fuel mixture passing through the mist separation section (inertial collision wall 46) is reduced, and the oil 57 once formed into an oil film is scattered again by the air-fuel mixture and rides on the air-fuel mixture to form an oil separator The phenomenon of being taken out of the chamber 41 can be suppressed.

  (2) Since air is introduced into the second space S2 by the air introduction part 52, the amount of air in the air-fuel mixture in the second space S2 is increased, thereby reducing the concentration of blow-by gas, Oil deterioration due to blow-by gas in the separator chamber 41 can be suppressed.

  (3) As a mist separation part of the oil mist processing device 39, a type (inertial collision type) including a throttle wall 45 having a throttle hole 48 and an inertial collision wall 46 provided on the downstream side of the throttle wall 45 is adopted. is doing. In this type, since the air-fuel mixture passes through the throttle hole 48 having a small flow path area, the flow rate of the air-fuel mixture is likely to be higher than that of an oil mist processing apparatus equipped with another type of mist separation unit, and once separated. In particular, the phenomenon that the oil 57 in the form of an oil film is scattered again by the air-fuel mixture is particularly likely to occur. Therefore, providing the air introduction part 52 in the oil mist processing device 39 is particularly effective in suppressing oil re-scattering.

  (4) The air introduction port 53 of the air introduction part 52 is opened substantially opposite to the flow of the air-fuel mixture after passing through the mist separation part. Therefore, compared with the case where air flows into the oil separator chamber 41 from a direction other than the above, the flow of the air-fuel mixture is efficiently weakened to reduce the flow velocity, and the re-scattering of the oil 57 that has become an oil film is surely suppressed. be able to.

  (5) As the air introduction part 52, one having an air introduction passage 54 for introducing air into the second space S <b> 2 of the oil separator chamber 41 and an adjustment valve 55 for adjusting the amount of air flowing through the air introduction passage 54 is adopted. is doing. This regulating valve 55 restricts the flow rate so that a certain amount or more of air does not flow into the second space S2, so that the concentration of blow-by gas in the crank chamber 33 increases due to the introduction of air, and the engine oil is reduced. Deterioration can be suppressed.

  (6) The air introduction passage 54 is connected to the downstream side of the air cleaner 56 in the intake passage 22. For this reason, clear air can be introduced into the second space S <b> 2 through the air introduction passage 54 without separately providing a means for capturing dust.

Note that the present invention can be embodied in another embodiment described below.
-In the said embodiment, you may change into the structure where the gas inflow port 43 serves as the drain hole 49. FIG. In this case, for example, as shown in FIG. 3, a gap 61 is provided between the lower end surface of the throttle wall 45 and the bottom of the oil separator chamber 41. The oil film-like oil 57 liquefied and separated from the air-fuel mixture flows upstream through the gap 61 and is returned from the gas inlet 43 to the crank chamber 33 side. In this case, the same effect as that of the above embodiment can be obtained. In FIG. 3, the same reference numerals are given to the same members, places, etc. as in the above embodiment.

  -This invention is applicable also to the oil mist processing apparatus which has a mist separation part of types other than the inertial collision type mentioned above. FIG. 4 shows an example in which the present invention is applied to an oil mist treatment apparatus having a labyrinth type mist separation unit. In this type, a plurality of partition walls 62 are provided in the oil separator chamber 41 to partition the internal space in a meandering manner. These partition walls 62 constitute a mist separation section. An oil return groove 64 having a drain hole 63 is provided below the oil separator chamber 41. A through hole (not shown) is formed in the bottom of the oil separator chamber 41. In FIG. 4, the same reference numerals are given to the same members, places, etc. as in the above embodiment.

  In this type of oil mist processing device 39, the air-fuel mixture flowing into the oil separator chamber 41 from the gas inlet 43 flows while meandering along the partition wall 62, and the oil mist in the air-fuel mixture flows in the partition wall 62. It adheres to and liquefies. The liquefied oil is dropped from the through hole at the bottom of the oil separator chamber 41 onto the oil return groove 64, guided to the drain hole 49, and returned to the crank chamber 33.

  Even in this type, the oil film-like oil 57 may be re-scattered by the air-fuel mixture with an increased flow velocity. Therefore, also in this case, the air introduction part 52 is provided, and air is introduced to the downstream side of the mist separation part (partition wall 62) of the oil separator chamber 41. By doing so, it is possible to suppress the oil from splashing again and riding on the air-fuel mixture and being taken out of the oil separator chamber 41 as in the above embodiment.

  The oil mist processing apparatus of the present invention can also be applied to an internal combustion engine that does not have a function of introducing outside air into a crank chamber and reducing the concentration of blow-by gas in the crank chamber. In this case, the blow-by gas flows in the blow-by gas passage instead of the mixture of the blow-by gas and the outside air in the above embodiment. And when blow-by gas passes an oil mist processing apparatus, oil mist is isolate | separated from the blow-by gas.

  -You may open the air introduction port 53 in the air introduction part 52 in the location different from the said embodiment about the oil separator chamber 41. FIG. Further, the air introduction port 53 does not necessarily have to be opened in a state of being opposed to the flow of the air-fuel mixture after passing through the mist separation unit. For example, the air introduction port 53 may be opened so as to intersect.

A plurality of air introduction parts 52 may be provided. A plurality of air inlets 53 may be provided for one air inlet 52.
The air introduction passage 54 of the air introduction part 52 may be provided to extend into the oil separator chamber 41.

The adjustment valve 55 in the air introduction part 52 may be omitted.
The air introduction unit 52 may forcibly send air to the downstream side of the mist separation unit in the oil separator chamber 41.

BRIEF DESCRIPTION OF THE DRAWINGS The schematic which shows the structure about one Embodiment which actualized this invention. The schematic sectional drawing of an oil mist processing apparatus. The schematic sectional drawing which shows another embodiment of an oil mist processing apparatus. The schematic sectional drawing which shows another embodiment of an oil mist processing apparatus.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 11 ... Gasoline engine (internal combustion engine), 22 ... Intake passage, 33 ... Crank chamber, 36 ... Blow-by gas passage, 39 ... Oil mist processing apparatus, 41 ... Oil separator chamber, 45 ... Restriction wall, 46 ... Inertial collision wall, 48 ... throttle hole, 52 ... air introduction part, 53 ... air introduction port, 54 ... air introduction passage, 55 ... regulating valve.

Claims (4)

An oil separator chamber provided in the middle of the blow-by gas passage connecting the crank chamber and the intake passage of the internal combustion engine;
In an oil mist processing apparatus comprising a mist separation unit that separates oil mist when blow-by gas flows through the oil separator chamber,
An oil mist processing apparatus comprising an air introduction part for introducing air downstream of the mist separation part in the oil separator chamber. The oil mist processing apparatus according to claim 1, wherein the mist separation unit includes a throttle wall having a throttle hole and an inertial collision wall provided on a downstream side of the throttle wall. 3. The oil mist processing apparatus according to claim 1, wherein the air introduction unit includes an air introduction port that opens substantially opposite to a flow of blow-by gas after passing through the mist separation unit. The said air introduction part is provided with the air introduction channel | path which introduce | transduces air into the said oil separator chamber, and the adjustment valve which adjusts the quantity of the air which flows through the said air introduction channel | path. Oil mist processing equipment.

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