JP2009221858A - Oil separator for blow-by gas - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an oil separator of a structure capable of surely separating oil so as to prevent oil mist from being carried to a gas discharge port even if blow-by gas passes through a cyclone outlet before oil mist in the blow-by gas is sufficiently separated at an inside of a cyclone chamber. <P>SOLUTION: The oil separator 10 includes a gas introduction port, a plurality of cyclone chambers 30a-30d, and the gas discharge port 14. An outlet passage 20 communicating to the gas discharge port 14 is formed at an outlet side of the cyclone outlets 32a-32d formed at centers of the cyclone chambers 30a-30d. The cyclone outlets 32a-32d and the gas discharge port 14 are arranged with separated by the outlet passage 20. A collision plate 22 which is arranged with facing a direction in which blow-by gas flowing out of the cyclone outlets 32a-32d, and with which blow-by gas blow-by gas flowing out of the cyclone outlets 32a-32d collide is provided in the outlet passage 20. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an oil separator for blow-by gas. More specifically, the present invention relates to an oil separator that collects oil mist in blow-by gas generated in an engine crankcase of an internal combustion engine such as an automobile engine, and to an oil separator that collects oil mist by a cyclone.

In an internal combustion engine, for example, an automobile engine or the like, when the blow-by gas leaking from the gap between the piston ring and the cylinder wall is discharged into the atmosphere during operation, so-called PCV (positive crankcase) The blow-by gas is returned to the intake system by the ventilation system and recombusted.
Here, since the blow-by gas contains oil mist in which lubricating oil such as engine oil is atomized, it is necessary to prevent the oil mist in the blow-by gas from flowing out into the intake system. Therefore, as means for separating and collecting the oil mist in the blow-by gas, an oil mist collecting device (oil separator) is provided on the inside of the cylinder head cover or in the middle of the connecting flow path connecting the crankcase and the intake pipe. .

As such an oil separator, a so-called cyclone type oil separator is widely used. For example, Japanese Patent Laid-Open No. 2001-246216 (Patent Document 1) describes a cyclonic oil separator.
By the way, the cyclone type oil separator has a limited range of flow rate of blow-by gas in which the cyclone can exhibit the best performance. When the oil separator is configured with a single cyclone as in Patent Document 1, when the flow rate of blow-by gas is small, there is a problem in that the ability to collect oil mist is reduced.

  Thus, Japanese Patent Publication No. 2002-540338 (Patent Document 2) proposes an oil separator including a plurality of cyclones instead of a single cyclone. By reducing the size of the cyclone, it is possible to effectively collect oil mist by generating a swirling flow even when the flow rate of blow-by gas is small. When the flow rate of blow-by gas is high, the oil mist is captured by multiple cyclones. The task is to share the collection work.

FIG. 7 shows an oil separator 110 having substantially the same configuration as the oil separator described in Patent Document 2. The oil separator 110 includes four cyclone chambers 130 including those that do not appear in FIG. In the oil separator 110, the blow-by gas leaked in the crankcase passes through the gas flow path from the gas introduction port 112 and is introduced into each cyclone chamber 130. The blow-by gas is discharged to a cyclone outlet 132 provided above the center of the cyclone chamber 130 while making a swivel motion in the cyclone chamber 130, passes through the gas discharge port 114 through the outlet passage 120, and the intake system of the internal combustion engine. Sucked into. At this time, the oil mist in the blow-by gas is separated from the blow-by gas by the centrifugal force due to the swirling motion and becomes liquid, and the oil that has become liquid flows through the bottom of the oil separator 110 and is discharged from the oil drain 116 to the crankcase. Returned.
JP 2001-246216 A JP-T-2002-540338

  However, in the oil separator 110 of the type shown in FIG. 7 described above, when the engine rotates at a high speed, the flow rate of blow-by gas increases and the flow rate of blow-by gas in the oil separator 110 increases. Since the flow velocity in the cyclone chamber 130 and the cyclone outlet 132 is also increased, the oil mist in the blow-by gas passes through the cyclone outlet 132 before being sufficiently separated in the cyclone chamber 130. Therefore, there is a problem that the oil mist is taken away to the gas discharge port 114 through the outlet passage 120.

  Therefore, the problem to be solved by the present invention is to ensure that the oil mist is not taken away to the gas discharge port even if the oil mist in the blow-by gas passes through the cyclone outlet before it is sufficiently separated in the cyclone chamber. An object of the present invention is to provide an oil separator having a structure capable of separating oil.

  In order to solve the above problems, the oil separator according to the present invention is provided with a collision plate facing the cyclone outlet, and the oil mist that has passed through the cyclone outlet collides with and adheres to the collision plate to reliably separate the oil. did.

Accordingly, a first invention of the present invention is an oil separator that collects oil mist contained in blow-by gas generated in an engine crankcase,
It has a gas inlet, a cyclone chamber, and a gas outlet, and the oil mist is agglomerated by centrifugal force due to the swirling motion of the blowby gas in the gas flow path where blowby gas is introduced from the gas inlet and discharged from the gas outlet. There is a cyclone room,
The cyclone chamber has a cyclone outlet in the center, and the cyclone outlet is disposed to open to an outlet passage of the gas flow path leading to the gas discharge port, and the cyclone outlet and the gas discharge port are separated from each other. And
In the outlet passage of the gas flow path where the cyclone outlet is opened, the blow-by gas that flows out from the cyclone outlet faces the flow direction, and the blow-out gas that collides can collide with the oil mist. A collision plate is provided.

According to the first invention, the oil mist in the blow-by gas that flows out from the cyclone outlet and flows into the outlet passage without being separated in the cyclone chamber collides with the collision plate arranged facing the cyclone outlet, It adheres and is separated from the blow-by gas.
Therefore, even if the oil mist in the blow-by gas passes through the cyclone outlet before it is sufficiently separated in the cyclone chamber, the oil can be reliably separated so that the oil mist is not taken away to the gas discharge port. And since the cyclone exit and the gas exhaust port are separated, there is no possibility that the oil adhering to the collision plate is taken away by the gas exhaust port.

Next, a second invention of the present invention is an oil separator according to the first invention,
The cyclone chamber has a plurality of chambers arranged in a row on one side of the oil separator, and the cyclone outlet is arranged in a row on one side of the outlet passage. The cyclone outlet is expanded on the outlet passage side. An expanded diameter part is formed,
The outlet passage is attached to the engine body in an inclined state in which the side where the cyclone outlets are arranged in a row is the lower side and the central part of the enlarged diameter part is lower than the peripheral part.
According to the second aspect of the invention, the oil adhering to the collision plate accumulates on the side where the inclined collision plate and the cyclone outlet of the passage bottom of the outlet passage are formed. Then, when the flow rate of blow-by gas is reduced or the engine is stopped, it is recovered from the oil drain from the enlarged diameter portion of the cyclone outlet via the cyclone chamber. Therefore, it is easy to collect the oil collected in the outlet passage.

Next, a third aspect of the present invention is an oil separator according to the second aspect of the present invention, and is arranged inside a cylinder head cover of an automobile engine.
According to the third aspect of the present invention, the cyclones are formed in a line and the oil separator has a horizontally long shape, so that it can be arranged inside the cylinder head cover. And since an oil separator can be arrange | positioned inside a cylinder head cover, compactization of a motor vehicle engine can be achieved.

According to each invention of the present invention described above, the following effects can be obtained.
First, according to the first invention described above, even when the oil mist in the blow-by gas passes through the cyclone outlet before it is sufficiently separated in the cyclone chamber, it is ensured that the oil mist is not taken away to the gas discharge port. Oil can be separated. And since the cyclone exit and the gas exhaust port are separated, there is no possibility that the oil adhering to the collision plate is taken away by the gas exhaust port.
Next, according to the above-mentioned second invention, the oil adhering to the collision plate accumulates on the side where the cyclone outlet is formed at the bottom of the collision plate and the outlet passage. Then, when the flow rate of blow-by gas is reduced or the engine is stopped, it is recovered from the oil drain from the enlarged diameter portion of the cyclone outlet via the cyclone chamber. Therefore, it is easy to collect the oil collected in the outlet passage.
Next, according to the above-mentioned third invention, since the oil separator can be disposed inside the cylinder head cover, the automobile engine can be made compact.

Hereinafter, the best mode for carrying out the present invention will be described. First, the structure of the oil separator 10 which is one Example of this invention is demonstrated.
FIG. 1 shows an external front view of an oil separator 10 disposed inside a cylinder head cover of an automobile engine which is an embodiment of the present invention. As shown in FIG. 1, an oil separator 10 is a cyclone type oil separator having four small cyclone chambers 30a, 30b, 30c, 30d arranged in a row, and is located on the outlet side of the cyclone chambers 30a-30d. An outlet passage 20, a gas inlet 12 for introducing blow-by gas, a gas outlet 14 for discharging blow-by gas, and an oil drain 16 for recovering oil separated from the blow-by gas.

FIG. 2 shows an external plan view of the oil separator 10. As shown in FIG. 2, the cyclone chambers 30 a to 30 d are arranged at positions that are downward when viewed in FIG. 2.
3 is a cross-sectional view taken along the line AA in FIG. The structure of the oil separator 10 will be described with reference to FIG. The oil separator 10 is made of resin, and as shown in FIG. 3, is composed of four parts, a case 10A, a cyclone structure portion 10B, a gas discharge structure portion 10C, and a top plate 10D.
In the case 10A, the gas inlet 12 and the oil drain 16 shown in FIG. 1 are formed. The cyclone structure 10B is formed with cyclone chambers 30a to 30d and oil outlets 36a to 36d for collecting oil. The gas discharge structure 10C and the top plate 10D form an outlet passage 20. Cyclone outlets 32a to 32d and a passage bottom 24 of the outlet passage 20 are formed in the gas discharge structure 10C. And the site | part which faces cyclone exit 32a-32d of 10D of top plates is made into the collision board 22, and the gas exhaust port 14 is formed in the position spaced apart from the cyclone exit 32a-32d seeing in the plane direction. In addition, the arrangement | positioning space | interval from the cyclone outlets 32a-32d to the collision board 22 is made into the arrangement | positioning space | interval which the blow-by gas which flowed out from the cyclone outlets 32a-32d can aggregate oil mist by the collision at the time of the outflow. Yes.

Next, the oil separation function of the oil separator 10 will be described with reference to FIGS. 1 and 3.
The blow-by gas leaked into the crankcase flows into the oil separator 10 from the gas inlet 12 shown in FIG. 1, and passes through the gas flow path formed on the back side of the cyclone chambers 30a to 30d shown in FIG. Are introduced into the cyclone chambers 30a to 30d. Then, the oil mist is aggregated and separated from the blow-by gas by the centrifugal force generated by the swirling flow generated inside the cyclone chambers 30a to 30d. The separated oil adheres to the inner peripheral walls of the cyclone chambers 30a to 30d and flows down, or falls to the lower part of the cyclone chamber, and is discharged from the oil outlets 36a to 36d to the outside of the cyclone chambers 30a to 30d. The oil collected at the bottom of the case 10A is recovered from the oil drain 16 shown in FIG. On the other hand, the blow-by gas from which the oil mist has been separated is discharged from the cyclone outlets 32a to 32d to the outlet passage 20 formed on the outlet side of the cyclone chambers 30a to 30d.

Here, the cyclone chambers 30a to 30d of the oil separator 10 can effectively collect the oil mist by generating a swirling flow even if the flow rate of the blowby gas is small by reducing the size of the cyclone. When the flow rate is large, the oil mist is collected by a plurality of cyclones. However, when blow-by gas exceeding the cyclone processing capacity flows in, there arises a problem that the oil mist cannot be collected by the cyclone.
That is, when the engine rotates at a high speed, the flow rate of blow-by gas increases and the flow rate of blow-by gas in the oil separator 10 increases. Therefore, since the flow velocity in the cyclone chambers 30a to 30d and the cyclone outlets 32a to 32d is also increased, the cyclone outlets 32a to 32d are opened before the oil mist in the blowby gas is sufficiently separated in the cyclone chambers 30a to 30d. May pass through.

Therefore, in the oil separator 10, as described above, the oil mist is discharged from the gas discharge port by providing the outlet passage 20 having the collision type oil collecting mechanism on the outlet side of the blow-by gas discharged from the cyclone chambers 30 a to 30 d. 14 is being taken away.
That is, when blow-by gas containing oil mist flows out of the cyclone outlets 32a to 32d and flows into the outlet passage 20, the blow-by gas collides with the collision plate 22 provided facing the cyclone outlets 32a to 32d. Thus, the oil mist adheres to the collision plate 22 and is separated from the blow-by gas. Therefore, even if the oil mist in the blow-by gas passes through the cyclone outlets 32a to 32d before it is sufficiently separated in the cyclone chambers 30a to 30d, the oil mist is surely prevented from being taken away to the gas discharge port 14. Can be separated. Since the cyclone outlets 32a to 32d and the gas discharge port 14 are separated from each other, there is no possibility that oil adhering to the collision plate 22 is taken away by the gas discharge port 14.
The cyclone outlets 32a to 32d are smaller in diameter than the cyclone, and the blow-by gas flows out from the cyclone outlets 32a to 32d at a high speed, so the blow-by gas collides with the collision plate 22 at a high speed. Oil collection by the plate 22 is efficient.

Next, a method for collecting the oil collected by the collision plate 22 of the outlet passage 20 will be described.
FIG. 4 shows an external plan view of the oil separator 10 with the top plate 10D removed. As shown in FIG. 4, the cyclone outlets 32 a to 32 d are formed side by side at the lower end of the passage bottom 24 in the drawing.
FIG. 5 shows a cross-sectional view at the BB position in FIG. 4 in a state where the oil separator 10 is mounted inside the cylinder head cover of the automobile engine. As shown in FIG. 5, the cyclone outlet 32d is formed with a conical diameter-expanding portion 34d that expands on the outlet passage 20 side. In addition, the same diameter enlarged parts 34a-34c are formed also in the cyclone exits 32a-32c.
And as shown in FIG. 5, the oil separator 10 is attached in the state which inclined so that the side where the cyclone exit 32d etc. were located in a line may become a lower side. And it is set as the inclination state from which the center parts, such as the enlarged diameter part 34d, are lower than a peripheral part.
Therefore, in a state where the oil separator 10 is mounted inside the cylinder head cover of the automobile engine, the oil adhering to the vicinity of the cyclone outlets 32a to 32d in the outlet passage 20 can be freely dropped from the cyclone outlets 32a to 32d to the cyclone chambers 30a to 30d. It has a structure that can flow into the room.

  Therefore, the oil that has flowed out of the cyclone outlet 32d, etc., flowed into the outlet passage 20 and collided with the collision plate 22 was inclined while the engine was rotating at a high speed and the blowby gas was flowing into the outlet passage 20 at a high speed. It continues to accumulate on the side where the cyclone outlet 32d and the like of the passage bottom 24 of the outlet passage 20 are formed through the collision plate 22. Then, at idling or when the engine is stopped when the flow rate of blow-by gas is reduced, it flows into the cyclone outlet 32d and the like from the enlarged diameter portion 34d and the like of the cyclone outlet 32d and flows into the cyclone chamber 30d and the like from the oil outlet 36d and the like. The oil drain 16 collects the bottom of the case 10A. Therefore, it is easy to collect the oil collected in the outlet passage 20.

  FIG. 6 shows the flow of blow-by gas in the cross section shown in FIG. The blow-by gas flows into the cyclone chamber 30d and the like from the front side of the sheet of FIG. 6, and the oil mist is separated in the cyclone chamber 30d and the like. The blow-by gas containing oil mist that has not been separated in the cyclone chamber 30d etc. flows out of the cyclone outlet 32d etc., flows into the outlet passage 20, collides with the collision plate 22, and the oil mist is separated, The gas is discharged from the gas outlet 14 to the outside of the oil separator 10.

In the above-described embodiment, the oil separator having a configuration in which a plurality of cyclone chambers are arranged in a row is shown inclined, but the number of cyclone chambers may be one or may not be arranged in a row. Moreover, you may attach without making it incline. These configurations can be changed according to the space for installing the oil separator.
In the above embodiment, the oil separator is assembled inside the cylinder head cover of the automobile engine. However, the oil separator may be formed separately from the cylinder head cover.
Further, the collision plate may have any shape as long as it is arranged facing the direction of gas flow at the cyclone outlet.

The present invention is applicable not only to an oil separator attached to an automobile engine but also to an internal combustion engine other than an automobile engine as a separator for separating oil in blow-by gas generated inside.
In addition, the oil separator according to the present invention can be implemented in various forms within the scope of the idea of the invention.

It is an external appearance front view of the oil separator in one example. It is an external appearance top view of the oil separator in one Example. It is sectional drawing in the AA position of FIG. It is an external appearance top view in the state where the top plate was removed from the oil separator in one example. It is sectional drawing in the BB position of FIG. 4 of a state with the oil separator attached to the engine. It is a figure which shows the flow of blow-by gas in FIG. 1 is a cross-sectional view of an oil separator provided with a plurality of cyclones according to the prior art.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Oil separator 10A Case 10B Cyclone structure part 10C Gas discharge | emission structure part 10D Top plate 12 Gas introduction port 14 Gas discharge port 16 Oil drain 20 Outlet passage 22 Collision plate 24 Passage bottom part 30a, 30b, 30c, 30d Cyclone 32a, 32b, 32c , 32d Cyclone outlet 34a, 34b, 34c, 34d Expanded diameter part 36a, 36b, 36c, 36d Oil outlet

Claims (3)

An oil separator that collects oil mist contained in blow-by gas generated in an engine crankcase,
It has a gas inlet, a cyclone chamber, and a gas outlet, and the oil mist is agglomerated by centrifugal force due to the swirling motion of blow-by gas in the gas flow path where blow-by gas is introduced from the gas inlet and discharged from the gas outlet. There is a cyclone room,
The cyclone chamber has a cyclone outlet in the center, and the cyclone outlet is disposed to open to an outlet passage of the gas flow path leading to the gas discharge port, and the cyclone outlet and the gas discharge port are separated from each other. And
In the outlet passage of the gas flow path where the cyclone outlet is opened, the blow-by gas that flows out from the cyclone outlet faces the flow direction, and the blow-out gas that collides can collide with the oil mist. An oil separator having a collision plate disposed thereon. The oil separator according to claim 1,
The cyclone chamber has a plurality of chambers arranged in a row on one side of the oil separator, and the cyclone outlet is arranged in a row on one side of the outlet passage. The cyclone outlet is expanded on the outlet passage side. An expanded diameter part is formed,
An oil separator, wherein the outlet passage is attached to the engine body in an inclined state in which the side where the cyclone outlets are arranged in a row is the lower side, and the central portion of the enlarged diameter portion is lower than the peripheral portion. The oil separator according to claim 2,
An oil separator arranged inside a cylinder head cover of an automobile engine.

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