JPS6337461Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to an oil separator formed on the back surface of a cylinder head cover of an engine.

(Prior art) Blowby gas that leaks from the engine's combustion chamber into the crankcase and cylinder head cover contains a large amount of unburned gas, which causes air pollution. It is mandatory to install a crankcase ventilation system (so-called PCV system) that processes combustion in the combustion chamber. However, since the blow-by gas in the cylinder head cover contains oil scattered from the camshaft etc., if it is burned as is, the amount of oil consumed will increase and it will be uneconomical. Therefore, as shown in Japanese Utility Model Application Publication No. 57-148009, an oil separator having a meandering passage inside is formed on the back surface of the cylinder head, and the oil separator collides with the partition wall of the meandering passage. The oil in the blow-by gas is separated by adhering to the partition wall, and only the gas components are returned to the intake system.

However, in this case, the pressure inside the cylinder head cover becomes negative due to the intake pressure, and there is a risk of oil leaking from the gasket portion or the like. Therefore, as a countermeasure, the oil separator is divided into two chambers, a first chamber and a second chamber, and the first chamber is interposed in the first blow-by passage that communicates the inside of the cylinder head cover with the intake passage upstream of the throttle valve. , a second blow-by passage that communicates the inside of the cylinder head cover with the intake passage downstream of the throttle valve.
A structure is adopted in which a so-called PCV valve is interposed between the second chamber and the throttle valve.

In the above structure, when the opening degree of the throttle valve is small, the PCV valve opens and blow-by gas is sucked downstream of the throttle valve via the second blow-by passage, while fresh air from the air cleaner flows into the first It is introduced into the cylinder head cover via the blow-by passage to prevent negative pressure inside the cylinder head cover. At this time,
The PCV valve appropriately regulates the flow rate of blowby gas to prevent a large amount of blowby gas from being sucked into the intake system and causing a drop in output. Also,
When the opening degree of the throttle valve is large, the intake negative pressure in the second blow-by passage becomes small, so the PCV
The valve is closed and blow-by gas is drawn upstream of the throttle valve via the first blow-by passage. At this time, the first fresh air from the air cleaner
The blow-by gas replaces the blow-by gas in the blow-by passage, flows backwards, and is introduced into the cylinder head cover. However, such a structure tends to be complicated, and there is a problem that the air cleaner will be contaminated unless the oil separation function of the first chamber is improved.

(Problems to be Solved by the Invention) An object of the present invention is to solve the above problems and provide an oil separator for an engine that is simple in structure and has an excellent oil separation function.

(Means for Solving the Problems) The oil separator for an engine according to the present invention has a side wall that is erected on the back surface of the cylinder head cover and extends in the longitudinal direction of the engine and a side wall that extends in the width direction of the engine, so that the oil separator in the blow-by gas can be removed. A first chamber and a second chamber that separate the mist are formed with a predetermined gap in the longitudinal direction of the engine, and the first chamber and the second chamber are formed by a single oil bath that straddles the gap. closed from below by a full plate, and by the oil buff full plate and opposing side walls of the first chamber and the second chamber,
A space is formed in the gap position in which at least one side in the width direction of the engine is open in the cylinder head cover, and the first chamber has a first blowby which communicates the inside of the cylinder head cover with an intake passage upstream of the throttle valve. The second chamber is interposed in a second blow-by passage that communicates the inside of the cylinder head cover with the intake passage downstream of the throttle valve, and the second chamber is interposed in a second blow-by passage that communicates the inside of the cylinder head cover with the intake passage downstream of the throttle valve. It is characterized in that an opening is formed in at least one of the spaces to introduce blow-by gas from the space.

(Function) In the above oil separator, when the engine load is small and the opening degree of the throttle valve is small, the blow-by gas in the cylinder head cover is sucked downstream of the throttle valve via the second blow-by passage, and Oil mist is separated in the second chamber, and fresh air is introduced into the first chamber.
It flows into the cylinder head cover via the blow-by passage. On the other hand, when the engine load is large and the opening degree of the throttle valve is large, the blow-by gas in the cylinder head cover flows upstream of the throttle valve via the first blow-by passage, and
Oil mist is separated in the first chamber of the blow-by passage.

However, the space is not a partitioned room such as the first room or the second room, but rather a part of the room where the valve gear is located, and the blow-by gas containing a large amount of oil mist is generated. Although this space exists, the oil splashes caused by the valve train are blocked by the oil buffer plate at the bottom, and the oil splashes do not come onto the oil buffer plate.

The opening of the first chamber or the second chamber is
Since it faces the space above the oil buffer plate, it is possible to access the first or second chamber from this opening.
This eliminates the risk of oil droplets directly entering the chamber.

In addition, the above space is formed by using the oil buffer plate that forms the first and second chambers and the opposing side walls of the first and second chambers, reducing the need for special wall members and making it easier to use. Can be configured.

(Effect of the invention) Therefore, according to the invention, a single oil buffer plate is used to form the first chamber, the second chamber and the space, and the first chamber and the second chamber are used to form the space.
Since the opposite side walls of the chambers are used, the structure of the oil separator is simple, and the structure of the oil separator is simple.
Oil is less likely to be sucked directly into the chamber, the oil separation function of the oil separator is significantly improved, and the air cleaner is less likely to be contaminated with oil.

(Example) Hereinafter, an example of the present invention will be described based on the drawings.

As shown in FIG. 1, the engine body 1 consists of a cylinder block 2, an oil pan 3, a cylinder head 4, and a cylinder head cover 5 that is provided on the top surface of the cylinder head 4 and covers a valve train such as a camshaft. Become.

The intake system includes an air cleaner 7 and an intake manifold 9 connected downstream thereof via a carburetor 8. The carburetor 8 is equipped with a throttle valve 10, and the downstream end of the intake manifold 9 communicates with a combustion chamber (not shown) of the cylinder head 4.

The first blow-by passage 11 is a pipe line that communicates the inside of the cylinder head cover 5 with the intake passage of the air cleaner 7 located upstream of the throttle valve 10.

The second blow-by passage 12 is a conduit that communicates the inside of the cylinder head cover 5 with the intake passage of the intake manifold 9 located downstream of the throttle valve 10, and there is a so-called
A PCV valve 13 is provided.

The oil separator 14 is formed on the back surface of the cylinder head cover 5 which is covered on the upper surface of the cylinder head 4, and is formed on the back surface of the cylinder head cover 5, which is covered with the upper surface of the cylinder head 4.
A smaller second chamber 16 is arranged to be separated by a space 17 in the longitudinal direction of the engine main body 1, and a single oil-buffed plate 18 is provided on the bottom surface of the first chamber 15, second chamber 16, and space 17. It is provided.

That is, the first chamber 15 has a peripheral wall formed by a side wall 19 that stands up on the back surface of the cylinder head cover 5 and extends in the longitudinal direction of the engine body 1, and side walls 23 and 26 that also extend in the width direction of the engine body 1. At the same time, the lower surface is closed by the oil buffer plate 18. A meandering passage 21 is formed inside the first chamber 15 by a plurality of interference walls 20 erected in a zigzag pattern.
The first chamber 15 has an opening 24 bored in the side wall 23 on the upstream side (space 17 side) of the meandering passage 21, and a first chamber 15 on the downstream side of the meandering passage 21.
A chamber outlet 25 is provided. This first chamber exit 2
5 is connected to a first blow-by passage 11. Note that another opening 27 is bored in the corner of the side wall 26 on the opposite side.

On the other hand, the second chamber 16 is connected to the cylinder head cover 5.
side walls 28 and 29 that are erected on the back surface of the engine body 1 and extend in the longitudinal direction of the engine body 1;
Side walls 22 and 28 extending in the width direction form a peripheral wall, and the lower surface is closed by the oil buffer plate 18. and,
The second chamber 16 has an opening 30 formed in a longitudinal side wall 29 and a second chamber outlet 31 formed in the opposite corner thereof. A blow-by passage 12 is connected.

The space 17 is formed in the gap between the first chamber 15 and the second chamber 16 by the opposing side walls 2 of the two chambers 15 and 16.
3 and 22 and a partition wall 32 connecting these side walls 23 and 22, a peripheral wall is formed, and an opening that opens downward into the cylinder head cover 5 is provided on both sides of the oil buffer plate 18 in the engine width direction. A portion 37 is formed.

The oil buffer plate 18 is a substantially rectangular plate-like body, has a bend 33 around the periphery for reinforcement, and is connected to the side wall 19 by a plurality of machine screws 34.
It is fixed to the lower end of 28. The oil buffer plate 18 has two oil discharge grooves 3 which also serve as reinforcing ribs in the center of the first chamber 15.
5 and 36 are formed. One oil drain groove 35 extends through the opening 24 to the side edge of the space 17, and the other oil drain groove 36 extends through the opening 24.
It extends to the side edge where 7 is located.

When the engine is operated, blow-by gas leaks from the combustion chamber into the cylinder head cover 5, and oil is scattered from the camshaft etc. rotating within the cylinder head cover 5. However, oil splashes are caused by oil-bufferful plate 18.
It is obstructed by the oil buffer plate 18 and does not come on top of this oil buffer plate 18. In other words, although oil mist exists in the space 17, the oil-buffer plate 18
There are almost no oil droplets on the surface.

Therefore, when the engine load is small and the opening degree of the throttle valve 10 is small, the PCV valve 13 opens and the inside of the second blow-by passage 12 becomes negative pressure due to the intake negative pressure downstream of the throttle valve 10. Therefore, the blow-by gas in the cylinder head cover 5 is sucked into the second chamber 16 through the opening 30 and collides with the side wall of the second chamber 16. The oil in the blow-by gas adheres to the side wall and is separated, flows down onto the upper surface of the oil buffle plate 18, and returns to the cylinder head 4 through the opening 30. The gas is transferred from the second chamber outlet 31 to the second blow-by passage 1.
The fuel is sucked into the pipe No. 2, reaches the combustion chamber via the PCV valve 13, and is combusted. At this time, to prevent excessive blow-by gas from being mixed with fresh air and reducing engine output, the PCV valve 1
properly regulates the flow rate of blow-by gas.
On the other hand, since the negative pressure in the air cleaner 7 is small, the fresh air is sucked into the first chamber 15 from the first chamber outlet 25 via the pipeline of the first blow-by passage 11, and the meandering passage 21, the opening 24, and the opening It is sucked into the cylinder head cover 5 via the section 37 for ventilation.

Throttle valve 10 due to heavy engine load
When the degree of opening is large, the PCV valve 13 is closed and the second blow-by passage 12 is blocked. Therefore, the blow-by gas inside the cylinder head cover 5 flows through the opening 37 and the space 17 to the opening 24 due to the negative intake pressure in the air cleaner 7.
The liquid is sucked into the first chamber 15 from above. In this case, since there are no oil droplets on the oil buffer plate 18 in the space 17, oil droplets do not directly enter the opening 24 on the oil buffer plate 18 that opens into the space 17. . The blow-by gas sucked into the first chamber 15 passes through the meandering passage 21 while colliding with the interference wall 20, so most of the oil adheres to the side wall 19 and the interference wall 20 and is separated from the gas. The oil drain groove 3 flows down to the oil buff full plate 18.
5 and 36 and returns to the cylinder head 4. Further, the gas is sucked into the pipe of the first blow-by passage 11 from the first chamber outlet 25, and the air cleaner 7
The air is mixed with fresh air, passes through the throttle valve 10 and the intake manifold 9, and reaches the combustion chamber where it is combusted. At this time, a part of the fresh air from the air cleaner flows backward while being replaced with blowby gas in the first blowby passage 11, and flows back into the first chamber 15 and the space 1.
7 into the cylinder head cover 5 for ventilation. Since most of the oil in the blow-by gas is separated in the first chamber 15, the air cleaner 7 is less likely to be contaminated with oil.

[Brief explanation of the drawing]

Fig. 1 is a front view of an engine according to an embodiment of the present invention, Fig. 2 is a bottom view of an oil separator of the same embodiment, Fig. 3 is a sectional view taken along the - line in Fig. 2, and Fig. 4 is a - line sectional view. DESCRIPTION OF SYMBOLS 1... Engine body, 4... Cylinder head cover, 6... Intake system, 10... Throttle valve, 11... First blow-by passage, 12... Second
Blow-by passage, 13... PCV valve, 14...
...Oil separator, 15...First chamber, 16...
2nd chamber, 17... Space, 18... Oil buffer plate, 19, 22, 23, 26, 28, 29
... Side wall, 24 ... Opening, 37 ... Opening.

Claims (1)

[Scope of utility model registration request] In the engine oil separator, which is provided on the upper surface of the cylinder head and is formed on the back surface of the cylinder head cover that covers the valve gear such as the camshaft, the oil separator is installed vertically on the back surface of the cylinder head cover and extends in the longitudinal direction of the engine. A first chamber and a second chamber for separating oil mist in the blow-by gas are formed with a predetermined gap in the longitudinal direction of the engine by the side wall and the side wall extending in the width direction of the engine. The first chamber and the second chamber are closed from below by a single oil buffer plate spanning the gap, and the oil buffer plate and opposing side walls of the first chamber and the second chamber, respectively, A space is formed in the gap position in which at least one side in the width direction of the engine is open in the cylinder head cover, and the first chamber has a first blowby which communicates the inside of the cylinder head cover with an intake passage upstream of the throttle valve. The second chamber is interposed in a second blow-by passage that communicates the inside of the cylinder head cover with the intake passage downstream of the throttle valve, and the second chamber is interposed in a second blow-by passage that communicates the inside of the cylinder head cover with the intake passage downstream of the throttle valve. 1. An oil separator for an engine, characterized in that an opening is formed in at least one side to introduce blow-by gas from the space.