JPS6210419Y2 - - Google Patents

Description

[Detailed description of the invention] (Field of industrial application) This invention relates to an oil drain structure in a blow-by gas reduction device (hereinafter abbreviated as PCV reduction device) for an automobile engine.

(Prior Art) Conventionally, a PCV reduction device for an automobile engine is provided with a passage (hereinafter referred to as a reduction passage) that guides blow-by gas derived from the engine to the engine intake system. It is necessary to remove the oil contained therein, and an oil cutting device is usually installed in this return path. This oil cutting device has a roughly cylindrical separation chamber that swirls the blow-by gas and separates the atomized oil contained in the blow-by gas by centrifugal action. The structure is such that the oil flows downward and is discharged.

(Problem that the invention aims to solve) However, installing such an oil cutter in the return path complicates the structure of the PCV reduction device, and when the amount of blow-by gas is large, the inner wall of the separation chamber Droplets of oil adhering to the blow-by gas may be swept away along the inner wall surface by the blow-by gas, and may not flow down smoothly from the oil hole and may enter the blow-by gas again, making it difficult to remove the oil sufficiently. There were times when I couldn't do it.

(Means for Solving the Problems) Therefore, in this invention, a separation chamber that is hermetically formed by a partition wall and a bottom plate is formed in the upper part of the head cover, and a connection pipe that opens at one end in the separation chamber is used to connect the separation chamber. The blowby gas reducing device for an automobile engine returns the blowby gas that has flowed into the head cover to the intake system, wherein the separation chamber is provided with an inlet through which the blowby gas flows along the inner wall surface of the partition wall; Further, the inner wall surface is formed smoothly and continuously so that the blow-by gas flows in a swirling manner within the separation chamber, and the inner wall surface of a portion located downstream of the blow-by gas flowing in a swirling manner is formed to be smoothly continuous. The connection pipe is arranged perpendicularly to the inflow port with its tip protruding from the inner wall surface of the partition wall, and the bottom plate of the separation chamber is formed in a collision shape with respect to the gas flow. By providing an oil hole in the formed inner wall portion to discharge oil below the separation chamber, the oil contained in the blow-by gas flowing from the PCV reduction device into the intake system can be sufficiently reduced. In addition, the separated oil can be returned to the engine's lubrication system with a small number of parts and a simple oil drain structure.

(Operation) Droplet-shaped oil that has been sufficiently separated from the blow-by gas by the centrifugal action and deposited on the inner wall surface is swept over the inner wall surface by the flow of the blow-by gas. The droplet-shaped oil that has been swept away on the inner wall surface stops at the inner wall surface portion formed in the collision shape, and is then quickly returned to the engine's lubrication system through the oil hole provided in the bottom plate.

(Example) Next, this invention will be explained based on the drawings.

FIG. 1 schematically shows an engine 1. A crankcase 2 of the engine 1 has a cylinder 3 and a piston 4, and a cylinder head 5 is attached to the upper part of the crankcase 2.
A head cover 6 is attached to the top of this cylinder head 5, and an intake manifold 7 is attached to the side of the cylinder head 5. An intake system 9 is attached to each. A main passage 11 for returning blow-by gas is provided between the upper surface of the head cover 6 and the intake manifold 7, and a PCV valve 10 for adjusting the amount of blow-by gas passing through this main passage 11 is installed on the upper surface of the head cover 6 on the inlet side. installed on. Further, the outlet side of the main passage 11 is attached to the intake manifold 7 by a connecting fitting 12. A bypass passage 15 is provided between the upper side of the head cover 6 and the air cleaner 9, through which the blow-by gas flows out to the air cleaner 9 when the amount of blow-by gas exceeds the maximum flow rate of the main passage 11. A separation chamber 23 for removing oil contained in the blow-by gas is provided on the side of the head cover 6 of the bypass passage 15, and the separation chamber 23 and the bypass passage 15 are communicated with each other through a connecting pipe 30.

Next, the separation chamber 23 formed inside the upper part of the head cover 6 will be explained. Side plate 6 of head cover 6
A thick wall portion 16 is formed in the upper part of b. This thick portion 16 is divided into a substantially rectangular shape by a front partition wall 24, a side partition wall 25, and a rear partition wall 26 that hang down like a skirt from the top plate 6a. The front partition wall 24 of the separation chamber 23 is substantially perpendicular to the thick wall portion 16, but its corners are gently curved surfaces 24a having a large radius of curvature. Further, the lateral partition wall 25 is also made approximately at right angles to the front partition wall 24, but its corners are also formed into gently curved surfaces 25a having a large radius of curvature. On the other hand, the rear partition wall 26 is made almost at right angles to the side partition wall 25, but its corners are steeply curved surfaces 26 with a small radius of curvature.
It is said to be a. Further, a bottom plate 31 is attached to the bottom of the separation chamber 23 with mounting screws 22.
The bottom is sealed. Note that an oil hole 31a for discharging the oil separated in the separation chamber 23 is provided in a portion of the bottom plate 31 near the steeply curved surface 26a.

On the thick wall portion 16 side of the rear partition wall 26, an inlet 29 is formed in a shape along the surface of the thick wall portion 16 so that the blow-by gas flowing in flows along the surface of the thick wall portion 16. In addition, a connecting pipe 30 is provided in the thick wall portion 16 for discharging blow-by gas from inside the separation chamber 23.
is provided in a direction perpendicular to the inlet 29.
The tip portion 30a of this connecting pipe 30 is a thick wall portion 30.
It is placed protruding from the This tip 30a
The position of the connecting pipe 30 is as shown in FIG.
Let A be the length of the protrusion from the inner surface 16b of the thick wall portion 16 into the separation chamber 23, that is, the amount of protrusion, and let B be the distance from the inner surface 16B to the inner surface of the lateral partition wall 25, then A becomes B. /5A4/5B range. This is because a good swirling flow of the blow-by gas is formed at this position, and the oil contained in the blow-by gas is sufficiently separated. In this way, the blow-by gas flowing in from the inlet 29 swirls along the surfaces of the thick wall portion 16, the front partition wall 24, and the side partition wall 25 in the separation chamber 23, and is then discharged from the connection pipe 30. has been done.

Next, the operation of this embodiment configured as described above will be explained.

As the rotational speed of the engine 1 increases, the amount of blow-by gas also increases, and it is no longer sufficient for the blow-by gas to flow out from the main passage 11 to the intake manifold 7, but instead flows into the separation chamber 23 and blow-by gas flows from the bypass passage 15. It is discharged. Here, since the suction force from the air cleaner 9 side is acting in the separation chamber 23, the blow-by gas flowing from the inflow port 29 flows into the separation chamber 23 at an increased speed. The blow-by gas that has flowed into the separation chamber 23 flows in the direction along the surface of the thick part 16 and forms a gently curved surface 2.
4a and the gently curved surface 25a, the flow direction is bent and flows as a swirling flow. Therefore, blow-by gas is transmitted to the thick wall portion 16, the front partition wall 24, and the side partition wall 2.
The air flows swirling along each inner wall surface of the connecting pipe 30 and is discharged from the air cleaner 9 side from the tip 30a of the connecting pipe 30. At this time, while the blow-by gas swirls and flows in the separation chamber 23, the oil contained in the blow-by gas in the form of a mist collides with the inner wall surface of the separation chamber 23, and is separated from the blow-by gas in the form of droplets. Here, when the amount of blow-by gas flowing through this bypass passage 15 is large, the separated droplet-shaped oil is swept away by the blow-by gas and moves along the inner wall surface. The droplet-shaped oil that has moved along the surface of the lateral partition wall 25 is connected to the lateral partition wall 25 and the rear partition wall 2.
The steep curved surface 26a between 6 and 6 has a small radius of curvature,
Since it is formed in a collision shape with respect to the flow of blow-by gas, and because the flow of blow-by gas at this portion is slow, it stays on the steeply curved surface 26a. Since the oil hole 31a is arranged in this part of the bottom plate 31, the droplet-shaped oil separated from the blow-by gas is quickly discharged from the oil hole 31a.

(Effect of the invention) This invention has a separation chamber formed in a sealed manner by a partition wall and a bottom plate at the top of the head cover, and blow-by gas flows into the head cover through a connecting pipe having one end opened in the separation chamber. In this device, the separation chamber is provided with an inlet through which the blowby gas flows along the inner wall surface of the partition wall, and the inner wall surface is smooth. The blow-by gas is formed to flow in a swirling manner within the separation chamber, and the inner wall surface of a portion located downstream of the swirling blow-by gas collides with the flow of the blow-by gas. The connecting pipe is disposed perpendicularly to the inlet, with its tip protruding from the inner wall surface of the partition wall, and the bottom plate of the separation chamber has an inner wall surface portion formed in a colliding shape. By providing an oil hole below the separation chamber to discharge oil, it is possible to sufficiently reduce the oil contained in the blow-by gas flowing into the intake system from the PCV reduction device, and the separated oil can be used to lubricate the engine. The number of parts that can be returned to the system is small, and a simple oil drain structure can be achieved.

[Brief explanation of the drawing]

The accompanying drawings illustrate embodiments of this invention, with FIG. 1 being a schematic diagram of an automobile engine, and FIG. 2 being a schematic diagram of an automobile engine.
FIG. 3 is a cross-sectional view of the separation chamber section viewed from the bottom side. 1...Engine, 6...Head cover, 23...
Separation chamber, 29... Inlet, 30... Connection pipe,
30a... tip, 31... bottom plate, 31a... oil hole.

Claims (1)

[Scope of utility model registration request] An automobile engine in which a sealed separation chamber formed by a partition wall and a bottom plate is formed in the upper part of a head cover, and blow-by gas flowing into the head cover is returned to the intake system through a connecting pipe having one end opened in the separation chamber. In the blow-by gas reducing device, the separation chamber is provided with an inlet through which the blow-by gas flows along the inner wall surface of the partition wall, and the inner wall surface is formed smoothly and continuously to reduce the blow-by gas. The gas is formed to flow in a swirling manner within the separation chamber, and the inner wall surface of a portion located downstream of the blowby gas flowing in the swirling manner is formed in a collision shape with respect to the flow of the blowby gas, and the connection A pipe is disposed perpendicularly to the inlet, with its tip protruding from the inner wall surface of the partition wall, and the bottom plate of the separation chamber has an inner wall surface portion formed in a colliding shape to discharge oil downward into the separation chamber. An oil cutter structure in a blow-by gas reduction device for an automobile engine, characterized in that an oil hole is provided to prevent oil leakage.