JPS6337464Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a breather chamber structure for extracting blow-by gas provided in a cylinder head cover of an internal combustion engine.

(Prior Art) In an internal combustion engine, a PCV system is employed to recirculate blow-by gas to the intake system, and a breather chamber for taking out the blow-by gas is provided in the cylinder head cover.

Since the blow-by gas contains oil components, in order to prevent this oil from flowing into the intake system, an oil trap chamber and many other obstructions are installed in the breather chamber, as disclosed in Japanese Utility Model Application Publication No. 56-149013. A plate was installed to separate the oil component in the blow-by gas.

(Problems that the invention aims to solve) However, the necessity to provide an oil trap chamber and a baffle plate makes the breather chamber large, and therefore the head cover also becomes large and compact.
There are limits to how much weight can be reduced, and the structure is complex.
The cost is also high.

The purpose of this invention is to be able to separate oil components from blow-by gas without installing an oil trap chamber or baffle plate, simplify the structure inside the breather chamber, and make the cylinder head cover more compact.
To provide a breather chamber structure that achieves weight reduction and contributes to cost reduction.

(Means for Solving the Problems) In order to achieve the above object, the present invention includes a passage-like breather chamber 20 extending in a substantially U-shape over substantially the entire surface of the cylinder head cover 1. Blow-by gas intake ports 26, 2 with different opening areas are formed near both ends of the breather chamber 20.
8 are provided respectively, and blow-by gas intake ports 26,
A blow-by gas outlet 7 is provided in a position that projects into the breather chamber 20 at a position shifted toward the blow-by gas inlet 26, which has a smaller opening area than the middle part between 28 and 28. A feature is that a cover member 31 is provided to prevent droplets from adhering.

(Function) According to such a breather chamber structure for taking out blow-by gas from an internal combustion engine, the breather chamber 20 is formed in the shape of a passage extending in a substantially U-shape over substantially the entire surface of the cylinder head cover 1. When the blowby gas introduced from the blowby gas intake port 28, which has a large area, passes through the passage-like breather chamber 20, the oil component in the blowby gas adheres to the inner wall surface of the breather chamber 20, causing separation of the oil component. will be accomplished.

In addition, since a small amount of blowby gas is introduced from the blowby gas intake port 26 with a small opening area, an excessive increase in suction negative pressure acting on the blowby gas outlet port 7 is suppressed, and the blowby gas intake port with a large opening area is The blow-by gas introduced from the inlet 28 interferes with the blow-by gas introduced from the blow-by gas intake port 26, which has a small opening area, in the breather chamber 20 before flowing into the blow-by gas intake port 7, so that the oil component is separated. The degree increases.

Furthermore, since the blow-by gas outlet 7 is provided so as to protrude into the breather chamber 20, the breather chamber 2
It is possible to prevent oil adhering to the inner wall surface from flowing out from the blow-by gas outlet 7 together with the blow-by gas.

(Example) Examples will be described in detail below with reference to the accompanying drawings.

FIG. 1 is a bottom view of the cylinder head cover 1 with a separator plate 21 attached thereto, and FIG. 2 is a bottom view of the head cover 1 alone.

The cylinder head cover 1 has a rectangular case shape, and there is a substantially U-shaped recess 1 in the ceiling of the cover 1.
form 1. A peripheral wall portion 16 is protrudingly provided to surround this recess 11, and the recess 11 has a portion 12 formed along one long side of the cover 1, a portion 13 formed along the short side, and a portion 16 formed along the other long side. A portion 14 formed along the portion up to the front of the end portion is continuous to form a substantially U-shape. An oil inlet 2 is formed at one end of the recess 11, that is, an end of the portion 12, and the ceiling portion of the cover 1 surrounded by the recess 11 is formed into a jetty portion 3. Four plug insertion ports 4... are provided.

and a recess 1 from one long side wall 5 of the cover 1.
1 includes a blow-by gas extraction pipe 6 to the upstream side of the intake system.
is inclined and protrudes, and its outlet 7 faces into the recess 11. A large number of protrusions 17 are integrally provided on the peripheral wall 16 surrounding the recess 11.

When such a head cover 1 is attached to a cylinder head (not shown), it is assembled so that the long side on which the extraction pipe 6 is provided is on the upper side and the other long side is on the lower side, and the part that is on the lower side of the recess 11 is attached. 14 is provided with an oil drain part 15 which is recessed toward the long side.

On the other hand, the separator plate 21 is as shown in FIG. 4, and has a substantially U-shape so as to be overlapped with the surface of the peripheral wall 16, and the peripheral edge of the plate 21 has mounting holes 22 that fit into the projections 17. . . . and an oil drain hole 23 that coincides with the oil drain portion 15, and a similar inlet 24 that coincides with the oil inlet 2 at one end of the plate 21.
form. An oil injection pipe (not shown) is inserted and fitted into both injection ports 2, 24.

Two small holes 25, 25 are formed in the portion of the separator plate 21 where the oil inlet 24 is provided, and these small holes 25, 25 serve as blow-by gas intakes 26. A large number of small holes 27... are formed in the other end of the plate 21, and these small holes 27... also serve as blow-by gas intakes 28. Thus, blow-by gas intakes 26, 28 with different opening areas are formed at both ends of the plate 21.

Further, the intake port 26 having a smaller opening area is provided with an eave-like cover plate 31. That is, a blow plate 31 having an eave-like protrusion 32 in the center that prevents blow-by gas from directly flowing into the two small holes 25, 25 is joined to the periphery of the small holes 25, 25, and the fifth As shown in the figure, the small holes 25, 25 are covered from below with eaves-like protrusions 32, and the protrusions 32 are opened laterally.

The separator plate 21 described above is stacked on the peripheral wall 16 of the head cover 1, the protrusions 17 are protruded from the mounting holes 22, and the protrusions 17 are crushed and caulked to connect the separator plate 21 to the plate 2.
1 to form a breather chamber 20 inside.

In the above, the blow-by gas outlet 7 is a portion where the flows of the blow-by gases flowing into the breather chamber 20 from the blow-by gas inlets 26 and 28 provided at both ends of the breather chamber 20 and having different opening areas interfere with each other; That is, it is provided at a position shifted toward the intake port 26 side having a small opening area (in the embodiment, at the middle of the portion 12). Note that 9 in FIG. 1 is a tube connected to the take-out pipe 6 for blow-by gas recirculation to the intake system.

Since the breather chamber 20 is formed in the shape of a passage extending in a substantially U-shape over almost the entire surface of the cylinder head cover 1, blow-by gas introduced from the blow-by gas intake port 28, which has a large opening area, flows through the passage-shaped passage. When passing through the breather chamber 20, the oil component in the blow-by gas adheres to the inner wall surface of the breather chamber 20, whereby the oil component is separated. In addition, since a small amount of blowby gas is introduced from the blowby gas intake port 26 with a small opening area, an excessive increase in suction negative pressure acting on the blowby gas outlet port 7 is suppressed, and the blowby gas intake port with a large opening area is The blow-by gas introduced from the inlet 28 passes through the blow-by gas inlet 26, which has a small opening area, before flowing into the gas intake port 7.
Blow-by gas and breather chamber 20 introduced from
Since the oil components in the blow-by gas can be separated as shown by the chain arrows in FIG. 1, the degree of separation of the oil components in the blow-by gas can be increased. Therefore, breather chamber 2
Oil separation can be performed without providing an oil trap or baffle plate inside the oil tank.

In addition, the blowby gas introduced from the blowby gas intake port 28 having a large opening area and the blowby gas introduced from the blowby gas intake port 26 having a small opening area interfere with each other.
Since the blow-by gas outlet 7 is provided so as to protrude into the breather chamber 20, the oil adhering to the inner wall surface of the breather chamber 20 is prevented from flowing out from the blow-by gas outlet 7 together with the blow-by gas, and the blow-by gas after oil separation is removed. The oil can be returned to the intake system from the blow-by gas outlet 7 as shown by the broken line arrow in FIG. 1, thereby preventing oil from entering the intake system.

Here, the separated oil is returned from the drain portion 15 to the lower cylinder head through the drain hole 23.

Also, if the opening areas of the intake ports 26 and 28 are changed,
Since the interference position of the blow-by gas flow can be changed variously, the degree of freedom in design is high.

Incidentally, the smaller intake port 26 is likely to be blocked by oil splash from the valve mechanism on the cylinder head, but the eave-shaped cover plate 3 as in the embodiment
1, it is possible to prevent oil droplets from directly adhering to the small holes 25, 25, and to ensure the opening area.

(Effects of the invention) As described above, according to the invention, the oil component can be separated from the blow-by gas without providing an oil trap chamber or baffle plate in the breather chamber, thereby simplifying the structure of the breather chamber. This makes the cylinder head cover more compact and lightweight.
Cost reduction can be achieved.

Further, by changing the opening area of the blow-by gas intake port, the interference position of the blow-by gas flow can be changed in various ways, thereby increasing the degree of freedom in arranging the blow-by gas intake port.

Further, since it is possible to prevent oil from entering the intake system, it is possible to prevent an increase in oil consumption and to make effective use of oil.

Furthermore, since a cover member for preventing oil droplets from adhering to the blow-by gas intake port, which has a small opening area, is provided, the opening area of the blow-by gas intake port can be secured.

[Brief explanation of the drawing]

Figure 1 is a bottom view of the cylinder head cover with a separator attached, Figure 2 is a bottom view of the head cover alone, Figure 3 is a sectional view taken along the line shown in Figure 2, Figure 4 is a bottom view of the separator alone, and Figure 5. Figure 4-
FIG. In the drawing, 1 is a cylinder head cover, 7 is a blow-by gas outlet, 11 is a recess, 20 is a breather chamber, 21 is a separator, 26 and 28 are blow-by gas inlets, and 31 is a cover plate.

Claims (1)

[Scope of utility model registration request] A passage-like breather chamber extending in a substantially U-shape over substantially the entire surface of the cylinder head cover is formed in the cylinder head cover, and blow-by gas intake ports with different opening areas are provided near both ends of the breather chamber. , a blow-by gas outlet is provided in a position that is shifted toward the blow-by gas intake having a smaller opening area than the intermediate portion between the two blow-by gas intake ports so as to protrude into the breather chamber; A breather chamber structure for extracting blow-by gas from an internal combustion engine, characterized in that a cover member for preventing oil droplets from adhering to the intake port is provided.