JP2000310109A - Breather structure for engine for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a structure for surely collecting oil part in blowby gas within a cylinder head over. SOLUTION: Within a cylinder head cover 8, a breather plate 10 is mounted by being inclined backward (an inclined angle e) for engine front and rear directions and a breather chamber 11 is provided. A plurality of guide plates 15 are obliquely stood for a gas passage within the breather chamber 11 and oil drop holes 14 are formed on the front sides of the guide plates 15. Because the breather plate 10 is inclined backward, even if an engine is mounted on a vehicle by a transverse installation, oil part (m) in blowby gas flows down to the oil drop holes 14 are residual amount of oil part (m) can be reduced. Even if the engine is mounted by a longitudinal installation, oil separation becomes excellent, this breather structure can be shared for both usages and manufacturing cost can be reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION Generally, an engine of an automobile (such as a four-wheeled vehicle) efficiently drives the engine by returning a gas component in blow-by gas to an intake system. The present invention
The present invention relates to a breather structure for a vehicle engine that separates a gas component and an oil component in a blow-by gas in a cylinder head cover.

[0002]

2. Description of the Related Art A blow-by gas reducing device (PCV system), which is one of engine emission control systems, prevents blow-by gas from being discharged to the outside air and increases the efficiency of the engine by returning the blow-by gas to an intake system. . As shown in FIG. 5, the engine body 1 is connected to a manifold block 2 of an intake system, and a PCV valve 3 is laid out between the engine body 1 and the intake system. As shown in FIG. 6, when the blow-by gas in the crankcase is in an operating state ventilated by the PCV valve 3,
When the piston 5 in the cylinder block 4 is lowered, the blow-by gas passes through the gas passage hole 6 from the crankcase, passes through the cam chamber of the cylinder head 7, and reaches the inside of the cylinder head cover 8.

As shown in FIG. 7, a PCV valve 3 and a breather pipe 9 are attached to a cylinder head cover 8, and a breather plate 10 divides an internal space into upper and lower parts inside the cylinder head cover 8 to form a breather chamber 11 at an upper part. Is provided. As shown in FIGS. 7 and 8, the breather plate 10 has a plurality of guide plates 15 having gas passage holes 12, plug holes 13, and oil drop holes 14, which are adjacent to the oil drop holes 14 and in which the gas passage is strayed. Is erected. information
The lower part 15 is bent to have an L-shaped cross section, and the lower part is welded to the breather plate 10.

In the gas passage of the breather chamber 11, a blind path is formed by the guide plate 15 and the inner wall of the cylinder head cover 8, so that the blow-by gas strays. The blow-by gas that has reached the inside of the cylinder head cover 8 through the gas passage hole 6 is efficiently separated into a gas portion and an oil portion m by a breather chamber 11 (constituted by a gas passage in the cylinder head cover 8 and a breather plate 10). , PC
It is discharged from the V valve 3. In many cases, the shape of the cylinder head cover 8 and the breather plate 10 is used to improve the oil separation (separating the gas component and the oil component m). As shown in FIG. 7, a guide plate 15 is provided to meander the blow-by gas, oil separation is performed while increasing the distance to the PCV valve 3, and oil m separated from the blow-by gas is dropped from the oil drop hole 14 into the cylinder head 7. Returning to the cam chamber is performed.

When an engine is mounted on an automobile, as shown in FIGS. 9 (a) and 9 (b), in a vehicle with an engine installed vertically (for example, an FR car), the engine is restricted due to restrictions on the layout of the vehicle. The crankshaft of the main body 1 is mounted in the longitudinal direction of the vehicle body, and the engine body 1 is tilted rearward at an angle a in the longitudinal direction of the vehicle body, and the engine body 1 is tilted laterally by an angle b in the width direction of the vehicle body. ing. Also figure
10 (a) and 10 (b), in a vehicle with an engine placed sideways (FF vehicle as an example), the crankshaft of the engine body 1 is mounted so as to match the width direction of the vehicle body, and the engine body 1 is angled in the longitudinal direction of the vehicle body. The engine body 1 is horizontally inclined in the width direction of the vehicle body by being inclined backward by c. Here, the engine longitudinal direction refers to the engine body 1 based on the crankshaft direction.
The side to which the transmission is connected is the rear.

[0006] As shown in FIG.
In the car cylinder head cover 8, the breather plate
10 (floor surface) is tilted backward with respect to the front-rear direction of the engine, and when blow-by gas is discharged from the gas passage hole 12,
The gas flows while contacting the plurality of guide plates 15, and the gas reaches the PCV valve 3. Further, the oil portion m is guided by the guide plate 15 and the inner wall toward the oil drop hole 14, and the remaining oil portion m only collects around the oil drop hole 14 and most of the oil component flows down through the oil drop hole 14. Collected.

As shown in FIGS. 12 and 13, in a cylinder head cover 8 of an FF vehicle in which the engine is placed horizontally, a breather plate 10 (floor surface) is inclined (angle C) laterally with respect to the front-rear direction of the engine. The blow-by gas in the breather chamber 11 flows while contacting the plurality of guide plates 15, and the remaining oil m accumulates along the inner wall. Note that a structure in which the breather plate 10 is partially inclined is disclosed in Japanese Patent Application Laid-Open No. H7-180609. In this case, the oil amount m can be recovered by providing an oil drop hole 14 near the peripheral mounting portion 8a between the breather plate 10 and the inner wall of the cylinder head cover 8 (see Japanese Patent Application Laid-Open No. 7-83020). When mounting the breather plate 10 in the cylinder head cover 8,
As shown in FIGS. 15A and 15B, the breather plate 10
Fill the liquid gasket 16 at the end of the
10 and the peripheral mounting surface 8a of the cylinder head cover 8 are brought into close contact with each other (see Japanese Patent Application Laid-Open No. 7-19019), and are tightly fixed with rivets and screws 17 (see Japanese Patent Application Laid-Open No. 7-42527).

[0008]

The breather chamber
In hole 11, the oil m in the blow-by gas is drained off.
The oil is collected by flowing down from 14, but if a large amount of separated oil m remains in the breather chamber 11, the oil m concentrates around the PCV valve 3 when a large lateral G works due to the turning motion of the vehicle or the like. Then, the oil amount m flows out from the PCV valve 3 to the intake system together with the blow-by gas, and the oil consumption proceeds, and phenomena such as emission of white smoke from the exhaust system occur. Also, sludge generated by the deterioration of the remaining oil content m stains the breather chamber 11,
The amount of oil m that has flowed into the intake system is the manifold block 2.
May be stained. Further, there is a possibility that the oil drop hole 14 may be closed by a large amount of sludge.

As described above, the oil m
If this remains, the reliability of the engine will be reduced. However, due to manufacturing, the oil drop hole 14 is formed at a position slightly away from the wall of the breather chamber 11, so that a part of the oil m to be returned from the oil drop hole 14 remains in the breather chamber 11. Therefore, in order to reduce the residual oil content m in the breather chamber 11, as shown in FIG. 14, the oil drop hole 14 is laid out near the wall where the oil content m is likely to remain (the distance of the interval d is shortened). I have to.

Therefore, in the above-described vertical engine FR vehicle, as shown in FIG. 11, the oil amount m is collected in the vicinity of an oil drop hole 14 formed at the corner of the guide plate 15 of the breather plate 10 to improve the efficiency. Often dropped. On the other hand, in an FF vehicle with a horizontal engine, as shown in FIGS. 12 and 13, the oil m gathers toward the inner wall of the breather chamber 11 due to gravity, and the oil m remains along the wall of the breather chamber 11. However, the amount is larger than that of FR vehicles. Even for FWD vehicles, F
It is desired to reduce the residual oil m in the breather chamber 11 by applying a breather structure common to the R car.

On the other hand, as shown in FIG. 15, the cylinder head cover 8 and the breather plate 10 are
Screw the breather plate 10 when fixing with
Excess gasket 16 when tightened at 17
May appear inside 11 (on breather plate 10).
At this time, if the oil drop hole 14 of the breather plate 10 is laid out near the wall of the breather chamber 10, the oil drop hole 14 may be blocked by the gasket 16, and the function of the oil drop hole 14 is impaired and the breather chamber 11 It is not possible to sufficiently remove the oil m accumulated in the oil.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a breather structure for a vehicle engine in which oil in a blow-by gas is reliably recovered in a cylinder head cover.

[0013]

According to the present invention, there is provided a breather structure for a vehicle engine, wherein a breather plate is formed on a cylinder head cover to form a breather chamber. A plurality of guide plates are erected in the breather chamber so that a gas passage in the breather chamber is a maze, and an oil drop hole is formed in the breather plate in close proximity to the gas flow-facing surface of the guide plate. Is attached to the cylinder head cover at an inclined angle so as to be inclined backward with respect to the front-rear direction of the engine.

According to a second aspect of the present invention, there is provided a vehicle engine in which a liquid gasket is interposed at a connecting portion between a cylinder head cover and a breather plate, and the connecting portion is connected by fixing means to form a breather chamber on the breather plate. In the breather structure, a protrusion having a cross-sectional convex shape is formed on a breather plate surface between the oil drop hole formed in the breather plate and the adjacent coupling portion.

According to a third aspect of the present invention, there is provided a vehicle engine in which a liquid gasket is interposed at a connecting portion between a cylinder head cover and a breather plate, and the connecting portion is connected by fixing means to form a breather chamber on the breather plate. In the breather structure, a groove is formed on a side closer to the breather chamber than a position of the fixing means of a coupling portion of the cylinder head cover which is close to an oil drop hole formed in the breather plate.

According to a fourth aspect of the present invention, a liquid gasket is interposed at a connecting portion between the cylinder head cover and the breather plate, and the connecting portion is connected by fixing means, so that the liquid gasket does not flow into an oil drop hole of the breather plate. In the breather structure of a vehicle engine in which a breather chamber is formed on the breather plate in such a manner as described above, a plurality of guide plates are erected in the breather chamber so that a gas passage in the breather chamber is a maze, and the guide is provided. An oil drop hole is formed in the breather plate near the gas flow facing surface of the plate, and the breather plate is attached to the cylinder head cover at an inclined angle so as to be inclined backward with respect to the engine front-rear direction. It is characterized by.

[0017]

Embodiments of the present invention will be described below with reference to the accompanying drawings. As shown in FIG. 2, in a horizontally mounted engine vehicle (FF vehicle), when mounted, the crankshaft of the engine body 1 is disposed substantially horizontally in the vehicle width direction,
As described above, the engine body 1 is inclined backward with respect to the vehicle longitudinal direction. The breather plate 10 mounted in the cylinder head cover 8 is mounted to be inclined rearward (inclined toward the transmission) with respect to the engine front-rear direction (crankshaft direction). Inside the cylinder head cover 8 shown in FIG. 1, the breather plate 10 is tilted rearward at an angle e with respect to when the engine body 1 is installed substantially horizontally, and a breather chamber 11 is provided on the breather plate 10. Breather plate
A plurality of guide plates 15 provided in 10 are attached obliquely to the gas passage in the breather chamber 11 (see FIG. 7), and an oil drop hole 14 is formed in front of the guide plate 15.

Thus, even if the inclination angle of the engine body 1 mounted on the FF vehicle in the front-rear direction of the engine is 0 °, the breather plate 10 is inclined backward by the angle e, and the breather plate
The oil m on the cylinder 10 does not accumulate along the inner wall of the cylinder head cover 8, but flows along the inner wall toward the engine rear side, and flows down to the oil drop hole 14 in front of the guide plate 15. Therefore, the amount of the oil m remaining in the breather chamber 11 is reduced, and the recovery efficiency is improved.
In addition, the rear leaning engine (FR vehicle) can maintain the same effect as before even with the breather structure described above, and the breather plate 10 and the cylinder head cover 8 can be shared. The layout can be handled by one specification.

Next, a configuration in which the cylinder head cover 8 and the breather plate 10 are tightly connected will be described. As shown in FIG. 3, when the end of the breather plate 10 is mounted on the mounting surface 8 a of the cylinder head cover 8, the liquid (fluidity) gasket 16 is interposed and the screw 17 is used to fasten the end of the breather plate 10. A projection 18 having a convex cross section is formed on the breather chamber 11 side, and an oil drop hole 14 is provided on the breather chamber 11 side close to the projection 18.

Thus, when the breather plate 10 is tightened with the screw 17 with the liquid gasket 16 interposed, the gasket 16 is crushed to fill the gap, and the surplus gasket 16 protrudes over the projection 18 having a convex cross section. As a result, it is prevented that the oil dropping hole 14 on the breather plate 10 is blocked by the surplus gasket 16. In addition, since the convex projection 18 has the same function as the inner wall of the breather chamber 11, the oil drop hole 14 is provided near the projection 18 so that the breather chamber 11 can be formed.
The remaining amount of the oil component m in 11 can be extremely reduced.

As shown in FIG. 4 (a), a groove 19 is provided on the mounting surface 8a of the cylinder head cover 8, and the outside of the groove 19 is tightened with a screw 17, and a liquid gasket 16 is previously mounted on the tightening position. A connection structure to be placed may be used.
In this case, as shown in FIG. 4B, when the breather plate 10 is fastened to the mounting surface 8a with the screw 17, the gasket
The gasket 16 is crushed to fill the gap, and the excess gasket 16 flows into the groove 19, so that the gasket
16 can be prevented from protruding. As a result, the oil drop hole 14 can be prevented from being blocked, so that the oil drop hole 14 can be installed close to the inner wall of the breather chamber 11, and the residual amount of the oil m can be reduced.

Further, by adopting the above-described coupling structure of the cylinder head cover 8 and the breather plate 10 in combination with the above-described breather structure in which the breather plate 10 is inclined backward, the remaining amount of oil m can be further reduced. Can be reduced.

[0023]

The present invention is as described above. According to the first aspect of the present invention, even when the engine is mounted horizontally on a vehicle in a horizontal state, the breather plate itself is inclined backward. Therefore, the oil on the breather plate can be concentrated around the oil drop hole, and the oil can be efficiently returned. Also, even if the engine body is mounted vertically, the oil-separating function does not change, and the parts having the breather structure can be used in common, and can be manufactured at low cost. Further, the reliability of the engine is improved. According to the second aspect of the present invention, since the excess liquid gasket generated when the cylinder head cover and the breather plate are connected to each other protrudes along the convex protrusion, it is difficult to protrude toward the breather chamber, and it is difficult for the gasket to protrude. The possibility of closing the oil drop hole provided is eliminated.
Therefore, a stable oil separation function can be obtained.

According to the third aspect of the present invention, the excess liquid gasket is absorbed by the groove formed on the mounting surface of the cylinder head cover instead of the convex projection of the second aspect of the present invention. The possibility of closing the oil drop hole provided above is eliminated. Therefore, a stable oil separation function can be obtained. According to the fourth aspect of the present invention, the breather plate in the breather chamber is tilted rearward, and the excess liquid gasket is guided so as not to flow into the oil drop hole. And the production cost can be reduced.

[Brief description of the drawings]

FIG. 1 is a sectional view of the inside of a cylinder head cover according to an embodiment of the present invention.

FIG. 2 is a side view showing a horizontal mounting of the engine body when the cylinder head cover of FIG. 1 is mounted.

FIG. 3 is a partial cross-sectional view showing a combined state of a cylinder head cover and a breather plate according to another embodiment of the present invention.

FIG. 4 is a partial cross-sectional view showing a connection state between a cylinder head cover and a breather plate according to still another embodiment of the present invention, (a) before connection and (b) after connection.

FIG. 5 is a schematic diagram showing a conventional engine intake system.

FIG. 6 is a schematic diagram showing an engine body of a conventional engine intake system.

FIG. 7 is a plan view of a conventional breather structure of an engine body.

8 is a plan view of the breather plate shown in FIG.

FIG. 9 is a schematic diagram illustrating a conventional vertical mounting type in which an engine is mounted on a vehicle, when viewed from a vehicle body side view (a) and a vehicle body front view (b).

FIG. 10 is a schematic diagram illustrating a conventional horizontal mounting type in which an engine is mounted on a vehicle, when viewed from the side of the vehicle body (a) and from the front (b) of the vehicle body.

FIG. 11 is a plan view showing a breather structure of a conventional vertical engine.

FIG. 12 is a cross-sectional view of a breather structure of a conventional horizontal engine in a side view of a vehicle body.

FIG. 13 is a plan view showing a breather structure of a conventional horizontal engine.

14 is a main part plan view for explaining residual oil content m of the breather structure in FIG. 13;

FIG. 15 is a cross-sectional view illustrating a state of connection between a conventional cylinder head cover and a breather plate before (a) and after (b).

[Explanation of symbols]

 8 Cylinder head cover 8a Mounting surface (coupling part) 10 Breather plate 11 Breather chamber 14 Oil drop hole 15 Guide plate 16 Liquid gasket 17 Screw (fixing means) 18 Projection 19 Groove e Inclined angle

Claims (4)

[Claims] In a breather structure for a vehicle engine in which a breather plate is formed on a cylinder head cover to form a breather chamber, a plurality of guide plates are erected in the breather chamber so that a gas passage in the breather chamber is a maze. An oil drop hole is formed in the breather plate adjacent to the gas flow facing surface of the guide plate, and the cylinder head cover is inclined at an angle so that the breather plate is inclined backward with respect to the engine front-rear direction. A breather structure for a vehicle engine, which is mounted on a vehicle. 2. A breather structure for a vehicle engine, wherein a liquid gasket is interposed at a connection portion between a cylinder head cover and a breather plate, and the connection portion is connected by fixing means to form a breather chamber on the breather plate. On the breather plate surface between the oil drop hole formed in the breather plate and the adjacent joint,
A breather structure for a vehicle engine, wherein a projection having a convex cross section is formed. 3. A breather structure for a vehicle engine, wherein a liquid gasket is interposed at a connection portion between a cylinder head cover and a breather plate, and the connection portion is connected by fixing means to form a breather chamber on the breather plate. A breather structure for a vehicle engine, characterized in that a groove is formed on a side closer to the breather chamber than a position of the fixing means at a coupling portion of the cylinder head cover which is close to an oil drop hole formed in a breather plate. 4. A liquid gasket is interposed at a connecting portion between the cylinder head cover and the breather plate, the connecting portion is connected by fixing means, and the liquid gasket is guided so as not to flow into an oil drop hole of the breather plate. In a breather structure for a vehicle engine in which a breather chamber is formed on the breather plate, a plurality of guide plates are erected in the breather chamber such that a gas passage in the breather chamber is a maze, and the guide plate faces a gas flow. A vehicle, wherein an oil drop hole is formed in the breather plate in proximity to a surface, and the breather plate is attached to the cylinder head cover at an inclined angle so as to be inclined backward with respect to an engine front-rear direction. Engine breather structure.