JPH11350934A - Blowby gas treatment device of engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an engine blowby gas treatment device which prevents entrance of blowby gas via the oil return passage and allows to release oil from the oil separation chamber. SOLUTION: This blowby gas treatment device of engine is provided with an oil separation chamber 10 and an oil return passage 30. The oil separation chamber 10 separates oil included in the blowby gas by flowing in the blowby gas through a blowby gas inlet 28. The oil return passage 30 intercommunicates the oil separation chamber 10 and a valve chamber, returning the oil separated in the oil separation chamber 10. An opening of the oil return passage 30 in the separation chamber side 33 is disposed at a position lower than the height position of another opening in the valve chamber side 12 which is opened to inside the valve chamber. As a result, oil stays in the oil return passage 30. Further, the communication of the internal space of the oil separation chamber 10 and the valve chamber is intercepted. Blowby gas is thus prevented from flowing out of the oil return passage 30 into the oil separation chamber 10, flowing into the oil separation chamber only through the blowby gas inlet.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a blow-by gas processing apparatus for an engine, and more particularly to a blow-by gas generated inside an engine to separate an oil component contained in the blow-by gas and to separate the separated oil. To a blow-by gas processing device for an engine that returns the gas to a valve operating chamber.

[0002]

2. Description of the Related Art Conventionally, there is an engine device provided with a blow-by gas processing device for returning blow-by gas leaked into a crank chamber from a gap between an engine cylinder and a piston to an intake passage. Some have an oil separation and return function of separating oil contained in blow-by gas and returning the separated oil to the engine.

FIG. 5 shows a cylinder head cover of a horizontally opposed engine from the inside, and is an explanatory diagram for explaining an oil separation and return function provided in a conventional blow-by gas processing apparatus. The cylinder head cover 1 according to the conventional example is mounted so as to close a crown (both not shown) of a cylinder head provided apart from each other in the left-right direction with respect to the crankshaft of the engine, and cooperates with the cylinder head. Thus, a valve operating chamber (not shown) is formed. The lower side in the figure is located on the lower side of the engine, and the upper side in the figure is located on the upper side of the engine.

The blow-by gas processing apparatus 3 has an oil separating chamber 60 having an oil separating function on the inner surface 1a of the cylinder head cover 1, and the oil separating chamber 60 is located between the inner wall surface 1a of the cylinder head cover 1 and the cylinder head side. A rib portion 70 that protrudes at a predetermined height toward the front side (in the drawing) to form a predetermined surrounded space 71, and is connected to and fixed to the protruding end portion 72 of the rib portion 70 and is surrounded by the cylinder head side of the surrounded space. Plate section (not shown)
The rib 70 and the plate cooperate to form an interior space with a predetermined volume between the inner wall 1a of the cylinder head cover 1 and the inner wall 1a.

The upper part of the oil separation chamber 60 is located near the upper end 1b of the cylinder head cover 1, and the upper part is connected to a blow-by gas inlet 61 for allowing blow-by gas to flow into the oil separation chamber 60, and is connected to the intake system. Blow-by gas outlet 62 is provided.

The lower portion of the oil separation chamber 60 extends to a position near the lower end 1c of the cylinder head cover 1,
The lowermost portion 63 is provided with an oil return hole 64 which is opened downward and communicates with the valve operating chamber so that oil in the oil separation chamber is quickly discharged. The horizontally opposed engine has a structure in which a predetermined amount of oil accumulates to a predetermined height position in the valve operating chamber during operation due to the height position between the cylinder and the crankshaft.
Numeral 4 is arranged at a position where it is immersed in oil accumulated in the valve operating chamber during operation.

In the oil separation chamber 60, the blow-by gas which protrudes from the inner wall surface 1 a of the cylinder head cover 1 toward the cylinder head at the same height as the rib portion 70 and flows into the oil separation chamber 60 from the blow-by gas inlet 61. A baffle rib 65 is provided to collide and change the flow.

According to the above configuration, the blow-by gas inlet 6
The blow-by gas flowing from 1 into the oil separation chamber 60 is caused to collide with the baffle rib 65 to be separated into an oil component and a gas component. The separated gas is discharged from the blow-by gas outlet 62 to the intake system, and the separated oil is separated by its own weight into the oil separation chamber 6.
It moves downward in the inside of the cylinder 0 and is returned to the valve operating chamber through the oil return hole 64.

At this time, the oil return hole 64 is immersed in a predetermined amount of oil stored in the valve operating chamber, so that the blow-by gas in the valve operating chamber enters the oil separating chamber 60 through the oil returning hole 64. To prevent the blow-by gas containing oil from being discharged to the intake system.

[0010]

However, the amount of oil accumulated in the valve operating chamber varies depending on operating conditions.
When the oil surface is located below the oil return hole 64, blow-by gas in the valve operating chamber
From the oil separation chamber 60.

During operation, the oil level of the oil that accumulates in the valve operating chamber is set to a high position, and the oil return hole 64 is set.
Even if the oil return hole 64 is provided at a position where it is sufficiently immersed in the oil, since the oil return hole 64 is opened downward at the lowermost part of the oil separation chamber 60, the blow-by existing in the form of foam in the oil The gas may enter the oil separation chamber through the oil return hole 64.

When such blow-by gas enters the oil separation chamber 60, splashes occur when the gas is separated from the oil surface, and oil mist is generated in the oil separation chamber 60, and the oil mist is contained. The exhaust gas contained white smoke in the intake system as it was, and could cause malfunction of the throttle system due to oil.

If the oil separated in the oil separation chamber 60 cannot be properly discharged from the oil separation chamber 60 to the valve operating chamber, the oil staying in the oil separation chamber 60 is blown out from the blow-by gas outlet 62, so-called. An oil blow is generated, and the exhaust gas similarly contains white smoke, which may cause a malfunction of the throttle system due to the oil component and may increase oil consumption of the engine.

Further, it may be difficult to provide the oil return hole 64 at a position immersed in oil for structural reasons in the valve operating chamber. In such a case, the oil component in the blow-by gas is separated. However, this could not be returned to the valve train.

The present invention has been made to solve the above-mentioned various problems, and an object of the present invention is to prevent an intrusion of blow-by gas from an oil return hole and to appropriately discharge an oil in an oil separation chamber. Another object of the present invention is to provide a blow-by gas processing apparatus.

[0016]

According to a first aspect of the present invention, there is provided a blow-by gas processing apparatus for an engine having a predetermined indoor space, wherein a blow-by gas is introduced from a blow-by gas inlet into the indoor space. An oil separation chamber that separates an oil component contained in the blow-by gas by flowing gas, an oil return passage that communicates the oil separation chamber with the valve operating chamber and returns the oil separated in the oil separation chamber to the valve operating chamber; The oil return passage is provided at a position lower than the height position of the valve chamber side opening of the oil return passage that opens into the valve chamber.

According to this, the oil flowing into the oil return passage from the oil separation chamber stays in the oil return passage and closes the oil return passage. Accordingly, communication between the oil separation chamber and the valve operating chamber in the indoor space can be cut off, and blow-by gas in the valve operating chamber can be prevented from passing through the oil return passage and entering the oil separating chamber.

As a result, the blow-by gas can be flown into the oil separation chamber through a regular route, and the oil contained in the blow-by gas can be appropriately separated.

When the amount of stagnant oil increases and the oil level in the oil return passage becomes higher than the opening position of the valve operating chamber side opening, the oil correspondingly moves from the valve operating chamber side opening to the valve operating chamber side. Discharged into the room. Therefore, the oil separated in the oil separation chamber can be appropriately returned to the valve operating chamber, and the amount of oil staying in the oil separation chamber can always be adjusted to a constant amount.

According to a second aspect of the present invention, there is provided a blow-by gas processing apparatus for an engine, wherein a valve-chamber-side opening that opens into the valve-chamber is provided at a position higher than a separation-chamber-side opening that opens into the oil separation chamber. It is characterized by having.

According to this configuration, the oil flowing into the oil return passage from the separation chamber side opening is always returned to the valve operating chamber side opening at a position higher than the separation chamber side opening. Stays in the passage and closes it. Therefore, communication of the interior space between the oil separation chamber and the valve operating chamber can be cut off as in the operation of the first aspect, and blow-by gas in the valve operating chamber passes through the oil return passage and enters the oil separation chamber. Can be prevented.

According to a third aspect of the present invention, there is provided an engine blow-by gas processing apparatus having an oil reservoir having a predetermined volume space at a bottom portion in an oil separation chamber and capable of storing a predetermined amount of separated oil. The passage is provided at a position where the opening on the separation chamber side opens into the oil reservoir, and the opening on the valve train chamber side is provided at a position higher than the oil reservoir.

According to this, the oil separated in the oil separation chamber is stored in an oil storage section provided at the bottom of the oil separation chamber, and an opening of the oil return passage formed in the oil storage section on the separation chamber side. From the section into the oil return passage.

Therefore, the oil can be reliably retained in the oil return passage and can be closed. As a result, the communication between the oil separation chamber and the valve operating chamber in the indoor space can be cut off, and the blow-by gas in the valve operating chamber passes through the oil return passage and enters the oil separation chamber. Can be prevented.

According to a fourth aspect of the present invention, there is provided a blow-by gas processing apparatus for an engine, wherein the oil separation chamber is provided to extend in the vertical direction inside the cylinder head cover of the horizontally opposed engine, and the valve chamber side opening is provided with a valve operating valve. An opening is formed on a vertical wall surface extending vertically in a room.

Thus, an oil separation chamber having a volume capable of separating oil in the blow-by gas can be ensured in a limited narrow space between the cylinder head cover and the cylinder head.

Further, since the valve-chamber-side opening is formed in the vertical wall surface, the oil level in the valve-chamber rises according to the operating condition of the engine and the like, so that the oil is immersed in the oil in the valve-chamber. However, it is possible to prevent the blow-by gas present in the oil within the valve operating chamber from entering into the oil separating chamber in the form of bubbles.

That is, the blow-by gas in the oil is
Although it moves upward toward the oil surface, the valve-chamber-side opening does not enter the oil return passage from the valve-chamber-side opening because the valve-chamber-side opening is opened laterally on the straight wall surface. .

According to a fifth aspect of the present invention, there is provided a blow-by gas processing apparatus for an engine, wherein the valve-chamber-side opening is formed so as to open upward. According to this, even when the valve-chamber-side opening is immersed in the oil in the valve-chamber due to an increase in the oil level in the valve-chamber, the opening is formed upward. The blow-by gas present in the form of foam in the oil can be reliably prevented from entering the oil separation chamber.

[0030]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a schematic view for explaining a first embodiment of the present invention, and shows a cylinder head cover of a horizontally opposed engine for an automobile from the inside.
In this embodiment, the same components as those of the conventional example are denoted by the same reference numerals, and detailed description thereof will be omitted.

As shown in the figure, the oil separation chamber 10 protrudes from the inner wall surface 1a of the cylinder head cover 1 toward the cylinder head (at the near side in the figure) at a predetermined height to form a surrounding space 21 surrounded by the rib. And a plate portion (not shown) connected to and fixed to the protruding end of the rib portion 20 and closing the cylinder head side of the surrounding space 21. Part 20, plate part and inner wall surface 1 of cylinder head cover 1
A room space having a predetermined volume is provided in cooperation with a.

An upper rib 22 extending in the left-right direction near the upper end 1b of the cylinder head cover 1 to form a ceiling of the oil separation chamber, and a rib 20 at a predetermined height from the lower end 1c of the cylinder head cover. A bottom rib 23 forming a floor surface and side wall ribs 24 forming left and right side wall surfaces are provided. The side wall ribs 24 are upper wall ribs 25a that respectively hang down from the left and right ends of the upper rib 22 by a predetermined length,
25b, the middle wall ribs 26a, 26b which approach each other from the lower ends of the upper wall ribs 25a, 25b by a predetermined distance, and then drop down by a predetermined length, respectively, and gradually approach as the lower ends of the middle wall ribs 26a, 26b move downward. The lower wall ribs 27a and 27b which hang down a predetermined length later.

The upper rib 22 is provided with a blow-by gas outlet 29 which is connected to the intake passage.
The upper side wall rib 25a is provided with a blow-by gas inlet 28 for allowing the blow-by gas to flow into the oil separation chamber.

An oil return passage rib 31 for forming an oil return passage 30 in the lower part of the oil separation chamber 10 in cooperation with the plate part in the surrounding space 21 defined by the rib part 20, and an oil separation part for the upper part. A baffle rib 35 for separating the oil contained therein by causing the blow-by gas flowing into the chamber 10 to collide and change the flow thereof.
Is provided. The rib 31 for the oil return passage and the baffle rib 35 are both provided from the inner wall surface 1a of the cylinder head cover 1 to the cylinder head side (front side in the drawing).
The projection is formed at the same height as 0.

The oil return passage rib 31 is formed of the bottom rib 2.
3, a horizontal rib 32 protruding from the lower wall rib 27b toward the lower wall rib 27a at a predetermined height from the lower wall rib 27b, and a lower end and a bottom rib 23 And a vertical rib 34 forming an opening 33 on the separation chamber side of the oil return passage 30, and has a substantially inverted L-shape.

The baffle rib 35 hangs down from the upper rib 22 into the oil separation chamber 10, and the lower end thereof is
a, and a blow-by gas passage 37 is formed in the oil separation chamber 10 in cooperation with the middle wall rib 26a. The gap width of the blow-by gas passage 37 is formed so as to be sharply narrowed downward from an inlet space 38 formed between the blow-by gas inlet 28 and the baffle rib 35.

The plate portion (not shown) has a substantially flat plate shape and is fixed to the projecting end side of the rib portion 20 by a plurality of fastening members. The oil return passage rib 31 is provided on the plate portion.
A valve operating chamber side opening 12 (indicated by a dotted line in the figure) which forms an opening on the valve operating chamber side of the oil return passage 30 is formed at a position corresponding to the lower position of the horizontal rib 32.

Accordingly, an oil return passage 30 and an oil reservoir 13 capable of storing a predetermined amount of oil are formed in a lower portion of the oil separation chamber 10.

Next, the oil separation chamber 10 having the above configuration
The function of will be described. According to the above configuration, the blow-by gas containing the oil component (indicated by a solid line arrow in the drawing) flows into the oil separation chamber 10 from the blow-by gas inlet 28, and is caused to collide with the baffle rib 35 in the inlet space 38. , Through the blow-by gas passage 37 and into the surrounding space 21.

Thus, the oil in the blow-by gas is liquefied by collision with the baffle rib 35. Further, the flow rate of the blow-by gas in the inlet space 38 is increased by passing through the blow-by gas passage 37, and the flow direction is also urged downward, so that the oil having a high specific gravity is blown downward. Therefore, the oil component and the gas component of the blow-by gas are gas-liquid separated in the oil separation chamber 10.

The separated gas is supplied to the blow-by gas outlet 2
9, is supplied to an intake system (not shown), and the separated oil component flows downward in the oil separation chamber 10 by its own weight, and the oil reservoir 1 in the oil separation chamber 10
3 and stay in the oil return passage 30. FIG. 2 is an explanatory diagram showing a state of oil staying in the oil reservoir 13 and the oil return passage 30. As shown in the drawing, the lower end of the vertical rib 34 is immersed in the oil accumulated in the oil reservoir 13, so that the communication between the oil separation chamber 10 and the interior space of the valve operating chamber is cut off.

Here, the reason why the oil sump 13 in which the oil stays is separately provided in addition to the oil return passage 30 will be described briefly. By simply interrupting the communication between the chambers, the oil volume in the oil return passage is small, and if the pressure in the valve operating chamber rises due to the engine operating condition, the oil is returned from the relationship with the pressure in the oil separation chamber. Oil in the passage 30 may be pushed out to the oil separation chamber side by the blow-by gas.

In such a case, the oil separation chamber 10 and the chamber space of the valve operating chamber are communicated by the oil return passage, and blow-by gas in the valve operating chamber may flow into the oil separation chamber from the oil return passage.

Therefore, in order to secure an oil amount that can withstand the pressure fluctuation in the valve operating chamber and the oil separation chamber 10, an oil reservoir 13 is provided separately from the oil return passage.

As a result, it is possible to reliably prevent the blow-by gas from entering the oil separation chamber 10 through the valve operating chamber side opening 12 and to allow the blow-by gas to flow through the regular route, that is, through the blow-by gas inlet 28 to the oil separation chamber. 10 can be introduced. Therefore, the oil component in the blow-by gas can be appropriately separated in the oil separation chamber 10.

When the oil level of the oil in the oil separation chamber 10 is higher than the valve chamber opening 12 of the plate portion, the oil overflows from the valve chamber opening 12 to move. It is returned to the valve room. Therefore, the oil in the oil separation chamber can always be adjusted to a constant amount.

Further, since the valve chamber opening 12 is formed in a substantially vertically disposed plate portion, the oil level in the valve chamber becomes higher than the position of the valve chamber opening 12. Even when the valve train chamber side opening 12 is immersed in the oil in the valve train chamber, blow-by gas present in the form of bubbles in the oil does not enter the oil return passage 30 from the valve train chamber side opening 12. Therefore, the intrusion of the blow-by gas from the oil return passage 30 can be reliably prevented.

As a result, the blow-by gas in the engine can flow into the oil separation chamber from the blow-by gas inlet 28, and the oil and gas components of the blow-by gas can be reliably separated in the oil separation chamber. As a result, it is possible to prevent the blow-by gas containing the oil component from being discharged to the intake system, to prevent the generation of white smoke in the exhaust gas, and to reliably prevent the malfunction of the throttle system due to oil contamination.

Next, a second embodiment of the present invention will be described below.

FIG. 3 is a schematic diagram for explaining a second embodiment of the present invention. In the present embodiment,
The same components as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted.

The characteristic feature of the present embodiment is that an oil return passage 40 is formed at a position outside the oil separation chamber 10 and an opening 41 on the valve operating chamber side opens upward in the valve operating chamber. That is being done.

The oil return passage 40 is constituted by a lower end of the lower side wall 27b and a plate portion. As shown in the drawing, an opening 43 on the separation chamber side is provided between the lower end of the lower side wall rib 27b and the bottom rib 23. A horizontal rib 44 extends a predetermined length laterally from the bottom rib 23, and a vertical rib 45 extends in a substantially vertical direction from a side end of the bottom rib 23 to a position higher than a lower end of the lower wall rib 27b. Have been.
A valve operating chamber side opening 41 that opens upward is formed between the upper end of the vertical rib 45 and the lower side wall rib 27b.

Then, by fixing the plate portion on the rib portion 20, an oil reservoir portion 13 capable of storing a predetermined amount of oil is formed on the bottom rib 23 of the oil separation chamber 10.

According to the above configuration, the oil component separated in the oil separation chamber flows down in the oil separation chamber 10 by its own weight, and the oil pool 1 in the oil separation chamber 10
3 and stay in the oil return passage 40. FIG. 4 is an explanatory diagram showing a state of oil staying in the oil reservoir 13 and the oil return passage 40. As shown in the drawing, the lower end of the lower wall rib 27b is immersed in the retained oil, so that the communication between the oil separation chamber 10 and the valve space is interrupted.

Accordingly, it is possible to prevent the blow-by gas from entering the oil separation chamber 10 through the valve operating chamber side opening 41, and to allow the blow-by gas to pass through the regular route, that is, the blow-by gas inlet 28 into the oil separation chamber 10. Can be flowed into.

As a result, the oil component in the blow-by gas can be appropriately separated in the oil separation chamber 10 and returned to the valve operating chamber, and the blow-by gas containing the oil component due to the inflow from the valve operating chamber side opening 41 can be obtained. It is possible to prevent gas from being discharged to the intake system.

When the oil level in the oil separation chamber 10 becomes higher than the valve operating chamber side opening 41, the corresponding oil overflows from the valve operating chamber side opening 41 and flows into the valve operating chamber. Will be returned. Therefore, the oil in the oil separation chamber 10 can always be adjusted to a constant amount.

Since the valve operating chamber side opening 41 is formed to open upward, the oil level in the valve operating chamber becomes higher than the position of the valve operating chamber side opening 41 and the oil level in the valve operating chamber is increased. Even in the case of immersion, the blow-by gas present in the form of bubbles in the oil is prevented from entering through the valve operating chamber side opening 41. Therefore, intrusion of blow-by gas from the oil return passage 40 can be reliably prevented.

According to the present embodiment, since the oil return passage 40 is formed outside the oil separation chamber 10, a larger volume in the oil separation chamber 10 is ensured as compared with the first embodiment. The oil separation capacity of the oil separation chamber 10 can be further improved.

The present invention is not limited to the above embodiments, and various changes can be made within the gist. For example, in each of the above-described embodiments, the valve-chamber-side opening is provided at a position higher than the separation-chamber-side opening, and the oil reservoir is provided in the oil separation chamber. However, the present invention is not limited to this. Although not particularly shown and described, the middle of the oil return passage is formed lower than the valve-chamber-side opening, and an oil reservoir is provided in the oil return passage. And the interior space of the valve train may be shut off.

[0062]

As described above, according to the blow-by gas processing apparatus for an engine according to the present invention, the oil that shuts off the interior space between the oil separation chamber and the valve operating chamber is retained in the oil return passage. Thus, the intrusion of blow-by gas from the oil return passage can be reliably prevented, and the oil component in the blow-by gas can be reliably separated by the oil separation chamber.

[Brief description of the drawings]

FIG. 1 is a schematic diagram for explaining a first embodiment of the present invention.

FIG. 2 is an explanatory diagram showing a state of oil staying in an oil reservoir and an oil return passage.

FIG. 3 is a schematic diagram for explaining a second embodiment of the present invention.

FIG. 4 is an explanatory diagram showing a state of oil accumulated in an oil reservoir and an oil return passage.

FIG. 5 is a schematic diagram for explaining a conventional example of the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 cylinder head cover 10 oil separation chamber 12 valve operating chamber side opening (first embodiment) 13 oil reservoir 28 blow-by gas inlet 29 blow-by gas outlet 30 oil return passage (first embodiment) 33 separation chamber side opening (first embodiment) 1 Embodiment) 40 Oil return passage (Second Embodiment) 41 Valve train chamber side opening (Second Embodiment) 43 Separation chamber side opening (Second Embodiment)

Claims (5)

[Claims] 1. A blow-by gas processing device for an engine, wherein an oil component contained in the blow-by gas is separated by passing a blow-by gas generated inside the engine, and the separated oil is returned to a valve operating chamber. An oil separation chamber that has an indoor space and separates an oil component contained in the blow-by gas by flowing the blow-by gas into the indoor space from a blow-by gas inlet; and the oil separation chamber and the valve operating chamber. An oil return passage communicating with the oil separation chamber and returning the oil separated in the oil separation chamber to the valve operating chamber; and a valve operating in the oil return path that opens into the valve operating chamber along a path of the oil return path. An engine blow-by gas processing device provided at a position lower than a height position of a chamber side opening. 2. The oil return passage, wherein a valve operating chamber side opening opening into the valve operating chamber is provided at a position higher than a separation chamber side opening opening into the oil separating chamber. The engine blow-by gas processing apparatus according to claim 1, wherein: 3. The oil separation chamber has a predetermined volume space at the bottom of the oil separation chamber, an oil reservoir that can store a predetermined amount of the separated oil, and the oil return passage includes the oil return passage. The chamber-side opening is provided at a position that opens into the oil reservoir, and the valve-operating chamber-side opening is provided at a position higher than the oil reservoir. Engine blow-by gas processing equipment. 4. The oil separation chamber is provided to extend vertically inside a cylinder head cover of a horizontally opposed engine, and the valve chamber side opening is vertically extended inside the valve chamber. The blow-by gas processing device for an engine according to any one of claims 1 to 3, wherein an opening is formed in a vertical wall surface. 5. The blow-by gas processing apparatus for an engine according to claim 4, wherein said valve chamber side opening is formed so as to open upward.