JP3206241B2 - Oil separator structure of internal combustion engine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in an oil separator structure of an internal combustion engine.

[0002]

2. Description of the Related Art In an internal combustion engine that recirculates blow-by gas blown from a combustion chamber into a crank chamber or a valve operating chamber on a cylinder head to an intake system, it is necessary to prevent oil from being carried away with the blow-by gas. is there.

[0003] Generally, an oil separator chamber is defined by attaching a baffle plate inside a cylinder head cover, and while blow-by gas passes through the oil separator chamber, oil contained therein is separated and collected in the oil separator chamber. The discharged oil is caused to flow down to the valve operating chamber from an oil drop hole opened in the baffle plate (Japanese Utility Model Laid-Open No. 57-171166, 58-23).
Nos. 44 and 63-26713).

[0004]

However, in such a conventional apparatus, the flow of the blow-by gas in the oil separator chamber and the flow of the oil separator in the oil separator chamber during the process in which the oil collected in the oil separator chamber flows down from the oil pit. There is a possibility that the oil is sucked up by the pressure difference between the chamber and the valve operating chamber, delaying the return of the oil, and increasing the oil consumption.

The present invention has been made in view of the above problems, and has as its object to provide a structure for quickly returning oil from an oil separator chamber in a cylinder head cover.

[0006]

According to the first aspect of the present invention,
A flat baffle plate inside the cylinder head cover
The plate-shaped bottom surface is installed at an angle to the horizontal line, and the upper and lower oil separator chambers that separate the oil contained in this by passing blow-by gas between them have multiple ignition plug bosses at an angle to the cylinder row. Are defined by inclined ribs integrally formed on the cylinder head cover so as to be connected to each other, and are formed by the spark plug boss, the inclined ribs, and the baffle plate.
A communication passage that defines an oil reservoir that is concavely recessed facing the lower portion of the upper oil separator chamber and that communicates the lowermost portion of the oil reservoir and the lower oil separator chamber that is positioned below the slope of the baffle plate. And an oil drop hole for communicating the lower oil separator chamber with the valve operating chamber.

According to a second aspect of the present invention, in the first aspect, a tubular pipe defining an oil drop hole is connected to the baffle plate. The invention according to claim 3 is
According to the first aspect of the present invention, a communication path is provided for communicating the lowermost portion of the oil reservoir with the lower oil separator chamber.

According to the first aspect of the present invention, since the oil reservoir chamber is concavely recessed facing the oil separator chamber, the oil reservoir chamber becomes stagnant with respect to the main flow of the blow-by gas in the oil separator chamber, and the oil flowing down the communication passage is not stagbled. The influence of the flow of the blow-by gas and the influence of the pressure difference with the valve operating chamber are suppressed, and the oil can be returned quickly. Further
Each rib is integrated with the center of the cylinder head cover.
Because it is formed so as to connect the spark plug ribs, cylindrical
The rigidity of the head cover can be increased,
It is possible to prevent radiation noise from being generated from the head cover.

According to the second aspect of the present invention, since a tubular pipe defining an oil drop hole is connected to the baffle plate, oil is prevented from flowing back through the oil drop hole due to a pressure difference between the oil separator chamber and the valve operating chamber. it can. Contract
According to the third aspect of the present invention, since the communication path communicating the lowermost part of the oil reservoir and the lower oil separator chamber is provided, the oil collected at the lowermost part of the oil reservoir is surely passed through the communication path to the lower side. It can be led to the oil separator chamber.

[0010]

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

FIGS. 1 and 2 show an embodiment in which the present invention is applied to a V-type six-cylinder engine. A baffle plate 7 is mounted inside a cylinder head cover 6 and upper and lower oil separator chambers are provided between the two. The blow-by gas refluxed to the intake system passes through the upper and lower oil separator chambers 8 and 9 so that the oil contained in the blow-by gas is separated. A valve chamber 10 is defined below the baffle plate 7 and the cylinder head, and the valve chamber 10 is provided with two camshafts via bearings 23 to open and close the intake and exhaust valves. It has become.

As shown in FIGS. 3 and 4, the resin cylinder head cover 6 includes a joining flange 11 for the cylinder head, a joining flange 12 for the baffle plate 7, and three ignition plug bosses 15 through which ignition plugs are inserted. ,
A rib 14 for partitioning the chain chamber 5, a boss 13 for the oil filler cap, and the like are integrally formed.

A plurality of horizontal ribs 21 projecting downward from the ceiling wall 20 of the oil separator chamber 8 are formed on the cylinder head cover 6, while, as shown in FIGS.
A plurality of lateral ribs 2 projecting upward are provided on the baffle plate 7.
2 are formed. The upper and lower lateral ribs 21 and 22 meander the blow-by gas flowing rearward of the engine according to the operating conditions, as shown by the black arrows in FIG. 2, to promote the separation of oil contained in the blow-by gas. .

The cylinder head cover 6 is provided on each ignition plug boss 1.
5 are integrally formed, and each inclined rib 16
The upper and lower oil separator chambers 8 and 9 are partitioned by.

An oil reservoir 17 is formed between each inclined rib 16 and the ignition plug boss 15 so as to face the lower part of the upper oil separator chamber 8 and to be concavely recessed. Each inclined rib 16 is connected to each spark plug boss 1.
5 in its tangential direction. That is, each inclined rib 16 is inclined at a predetermined angle with respect to the flow direction of the blow-by gas in the plan view (FIG. 2).

A communication passage 18 communicating the lowermost portion of the oil reservoir 17 and the lower oil separator chamber 9 is provided so that the oil accumulated in the upper oil separator chamber 8 flows down to the lower oil separator chamber 9. I have. In this example,
A recess 28 is formed at the lower end of the inclined rib 16, and a communication passage 18 is defined between the recess 28 and the baffle plate 7. The concave portion 28 is formed at a position close to the ignition plug boss 15.

Three oil drop holes 1 communicating the lower oil separator chamber 9 and the valve operating chamber 10 to the baffle plate 7
9 is formed so that the oil accumulated in the lower oil separator chamber 9 flows down to the valve operating chamber 10. Each oil drop hole 19 is opened at the lowermost part of the inclined baffle plate 7.

A pipe 45 communicating with an intake passage upstream of a throttle valve (not shown) is connected to a rear portion of the upper oil separator chamber 8. Upper oil separator chamber 8
Is connected to a pipe 47 communicating with the oil separator chamber of the right bank.

FIG. 6 shows the overall gas flow in the engine. Fresh air indicated by a white arrow in the figure passes through a pipe 45 from an intake passage upstream of the throttle valve, and a cylinder head cover of a left bank. 6 is introduced into an upper oil separator chamber 8.

A part of the fresh air is introduced from the lower oil separator chamber 9 through the fresh air inlet 14 into the valve operating chamber 10 to scavenge the valve operating chamber 10 and to remove oil return passages and chains (not shown). It flows through the chain chamber 5 defined through the cover 4 into the crank chamber defined by the pan 52 and the cylinder block.

The remaining fresh air is introduced from the upper oil separator chamber 8 into the right bank oil separator chamber 8 through the connecting pipe 47 between the banks. And the fresh air inlets 49, 50, 5 of the upper and lower oil separator chambers 8, 9 of the right bank.
1 to the valve chamber 10, scavenges the valve chamber 10, and flows into the crank chamber through an oil return passage (not shown).

The blow-by gas indicated by the black arrow in the drawing is sucked by the suction negative pressure generated downstream of the throttle valve, rises in the chain chamber 5, flows into the oil separator chamber 41 in the chain chamber 5, and here. After a certain amount of oil has been removed, the oil flows into the right bank oil separator chamber 9 through the blow-by pipe 42, from which the pipe 5
5 and is drawn into the intake passage downstream of the throttle valve via the flow control valve (PCV).

The flow control valve adjusts the amount of blow-by gas recirculation in accordance with the suction negative pressure generated downstream of the throttle valve, and reduces the amount of blow-by gas recirculation as the amount of intake air decreases. Adjust so as not to significantly disturb the air-fuel ratio.

Further, during a high load operation in which the suction negative pressure decreases near the full opening of the throttle valve, part of the blow-by gas flows back through the pipe 45 and returns to the intake passage upstream of the throttle valve.

The blow-by gas flowing through the upper oil separator chamber 8 is configured as described above, and as shown by the black arrow in FIG. , Baffle plate 7
It flows down and is collected in each oil reservoir 17 located below the upper oil separator chamber 8, and flows down to the lower oil separator chamber 9 through a communication passage 18 opened to each oil reservoir 17.

Since the oil reservoir 17 is concavely recessed facing the upper oil separator chamber 8, the oil reservoir 17 becomes stagnant with respect to the flow of the blow-by gas, and the oil flowing down through the communication passage 18 flows through the upper oil separator chamber 8. The influence of the flow of the blow-by gas and the influence of the pressure difference with the valve operating chamber 10 can be suppressed, and the oil can be prevented from flowing backward through the communication passage 18 and being sucked into the oil separator chamber 8.

From the communication passage 18 to the lower oil separator chamber 9
The oil that has entered flows down the baffle plate 7 along the partition plate 22 erected from the baffle plate 7, so that it is less affected by the flow of the blow-by gas in the lower oil separator chamber 9, and the The oil is collected in the oil drop hole 19 and flows down to the valve chamber 10 through the oil drop hole 19.

Further, since each of the inclined ribs 16 is located at the center of the cylinder head cover 6 and connects each of the ignition plug bosses 15, a radiated sound is generated from the cylinder head cover 6 by increasing the rigidity of the cylinder head cover 6. Can be prevented.

Next, in another embodiment shown in FIG. 7, a conical tubular pipe 25 defining an oil drop hole 19 is formed integrally with the baffle plate 7.

The pipe 25 is formed so as to be tapered in a range of 1 to 5 mm in diameter, so that an appropriate amount of oil is accumulated in the pipe to prevent the oil from flowing back through the oil drop hole 18.

Next, in another embodiment shown in FIG. 8, a concave portion 29 is formed in the baffle plate 7 so as to face the lower end of the inclined rib 16, and a communication passage 18 is provided between the inclined rib 16 and the concave portion 29. Is defined.

[0032]

As described above, according to the first aspect of the present invention, the baffle plate is provided inside the cylinder head cover .
The bottom of the substantially flat plate is attached to the horizontal line at an angle, and the upper and lower oil separator chambers that separate the oil contained in the blow-by gas through the blow-by gas are mounted between the cylinders. It is defined by inclined ribs integrally formed on the cylinder head cover so that it can be held and tied, and it is connected to the spark plug boss, inclined ribs, and baffle plate.
Therefore, while defining an oil reservoir that is recessed facing the lower portion of the upper oil separator chamber, a communication passage that communicates the lowermost oil separator chamber and the lower oil separator chamber located below the inclination of the baffle plate is formed. The oil drop hole that connects the lower oil separator chamber and the valve operating chamber is provided, so that the oil is less affected by the flow of blow-by gas in the oil separator chamber and the pressure difference from the valve operating chamber,
Oil can be quickly returned to the valve train.

According to a second aspect of the present invention, in the first aspect of the present invention, since a tubular pipe defining an oil drop hole is connected to the baffle plate, the oil drop hole is formed by a pressure difference between the oil separator chamber and the valve operating chamber. Backflow of oil can be prevented. According to a third aspect of the present invention, in the first aspect of the present invention, since a communication path communicating the lowermost portion of the oil reservoir and the lower oil separator chamber is provided, the oil collected at the lowermost portion of the oil reservoir is provided. Can be reliably guided to the lower oil separator chamber through the communication passage.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a cylinder head cover, a baffle plate, and the like showing an embodiment of the present invention.

FIG. 2 is a plan view of the cylinder head cover viewed from below.

FIG. 3 is a plan view of the cylinder head cover as viewed from above.

FIG. 4 is a longitudinal sectional view of the cylinder head cover.

FIG. 5 is a plan view of the baffle plate as viewed from below.

FIG. 6 is a side view of the baffle plate.

FIG. 7 is an exploded perspective view of the engine showing the flow of gas.

FIG. 8 is a cross-sectional view of a cylinder head cover and a baffle plate showing another embodiment.

FIG. 9 is a cross-sectional view of a cylinder head cover and a baffle plate showing still another embodiment.

[Explanation of symbols]

 Reference Signs List 6 Cylinder head cover 7 Baffle plate 8 Upper oil separator chamber 9 Lower oil separator chamber 10 Valve operating chamber 16 Inclined rib 17 Oil storage chamber 18 Communication passage 19 Oil drop hole

Continuation of the front page (56) References Japanese Utility Model Sho 62-57716 (JP, U) Japanese Utility Model Sho 60-63018 (JP, U) Japanese Utility Model Utility Model 2-147816 (JP, U) Japanese Utility Model Sho 62-18315 (JP) , U) (58) Fields investigated (Int. Cl. ⁷ , DB name) F01M 13/04 F01M 13/00 F02F 7/00

Claims (3)

(57) [Claims] 1. A substantially flat bottom surface of a baffle plate is attached to the inside of a cylinder head cover at an angle with respect to a horizontal line, and upper and lower oil separator chambers for separating an oil contained therein by passing a blow-by gas therebetween. A plurality of spark plug bosses are defined by inclined ribs integrally formed on the cylinder head cover so as to connect the spark plug bosses at an angle to the cylinder row.
A communication passage that defines an oil reservoir that is concavely recessed facing the lower portion of the upper oil separator chamber according to the rate , and that communicates the lowermost portion of the oil reservoir and the lower oil separator chamber that is located below the slope of the baffle plate. An oil separator structure for an internal combustion engine, wherein an oil drop hole is provided to communicate the lower oil separator chamber with the valve operating chamber. 2. A baffle plate is connected to a tubular pipe defining an oil drop hole.
An oil separator structure for an internal combustion engine according to the above. 3. The lowermost part of the oil reservoir and the lower oil separator chamber.
2. A communication path which communicates with a communication path is provided.
An oil separator structure for an internal combustion engine according to the above.