JPH07180609A - Cylinder head cover device for engine - Google Patents

Abstract

PURPOSE:To provide a cylinder head cover device for an engine capable of forming a head cover compact from the viewpoint of a whole engine and the reduction of a manufacturing cost including assembling, etc., by making a breather chamber, to be provided on the inner side of the head cover, into integrated structure of a resin. CONSTITUTION:A breather chamber C for introducing blowby gas and a lubricating oil mist from a crank case to separate them is provided by integrated molding of resin on the inner side of a head cover 21, joined to the cylinder head upper part of an engine to cover a valve system.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention is particularly applicable to automobiles, motorcycles,
The present invention relates to a head cover for closing an upper portion of a cylinder head of an engine such as an agricultural machine or a ship, and more specifically, to a cylinder head cover device for an engine in which a head cover and a breather chamber provided inside the head cover are integrally molded with resin.

[0002]

2. Description of the Related Art FIG. 3 shows an example of an engine 1 in which a cylinder block 2 having a piston mechanism and a crankcase with an oil pan 3, a cylinder head 5 having a valve mechanism 4, and an upper portion of the cylinder head 5 are closed. 1 schematically shows the configuration of a vehicle engine including a head cover 6 that covers the valve mechanism 4. The material of the head cover 6 is usually metal. As shown in FIG. 4, the head cover 6
A breather chamber 7 for separating blow-by gas and lubricating oil mist (a mixture of both of them is indicated by an arrow G in the figure) leaking into the crankcase is provided in the inside of the crankcase. Such a head cover structure is well known.

The breather chamber 7 includes a head cover 6
A space is formed by the partition wall 8 and the breather cover 9 in the upper part of the inside, and both sides of the space are separated by being closed by partition walls. Blow-by gas inlet 1 at one location of partition wall 8
1 is provided and is fed into the indoor space from here through a blow-by passage 10 which is a mixture G of blow-by gas and lubricating oil mist. In the breather chamber 7, the lubricating oil is separated from the blow-by gas and the lubricating oil mist that are the mixture G, and those gas components are separated from the blow-by gas outlet 1
The blow-by gas is sent to the blow-by gas reducing device (not shown) through the breather delivery pipe 13 from 2 to return the blow-by gas to the engine intake system again to prevent the release to the atmosphere.

By the way, such a conventional head cover 6 is used.
In the above structure, the breather chamber 7 needs to secure a required volume space in order to perform an appropriate separating function of the mixture G. Therefore, the partition wall 8 extending in the vertical direction
Must be provided at a certain height while being restricted by avoiding interference with the valve operating mechanism 4 below. Further, since the head cover 6 is made of metal, it is difficult to integrate the breather cover 9, and the head cover 6 and the partition wall 8 must be assembled together. That is, there are restrictions on securing the volume of the breather chamber 7, and there is also a problem that the manufacturing process is complicated due to the assembly structure.

[0005]

DISCLOSURE OF THE INVENTION According to the present invention, the breather chamber provided inside the head cover is made of a resin integrated structure, so that the head cover can be made compact from the viewpoint of the entire engine and the manufacturing cost including assembly can be reduced. An object is to provide a cylinder head cover device for an engine that is made possible.

[0006]

A cylinder head cover device for an engine according to the present invention comprises a blow-by gas blown from a crankcase by integral molding of a resin inside a head cover which is coupled to an upper part of a cylinder head of an engine and covers a valve operating mechanism. And a breather chamber for introducing and separating the lubricating oil mist.

[0007]

Since the head cover and the breather chamber can be integrally formed by resin molding, they are compact and the manufacturing cost is reduced as compared with the conventional assembly structure.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of an engine cylinder head cover device according to the present invention will be described below with reference to the drawings. FIG. 1 is an overall perspective view of a cylinder head cover device 20 of an embodiment provided on the uppermost part of the engine 1 described in FIG. FIG. 2 shows this cylinder head cover device 2.
The top view by the partial cross section of 0 is shown.

The head cover 21 is resin-molded in a shape and size that closes the upper portion of the cylinder head 5 shown in FIG. 3 and covers the valve operating mechanism 4. Head cover 21
A breather chamber C for separating the blow-by gas leaked from the crankcase and the lubricating oil mist by integral molding of resin is provided inside the.

The breather chamber C includes the head cover 2
The outer shell of 1 is an outer wall 21a, and the inner wall 23 is double-molded inside the outer wall 21a with a space 22 therebetween by blow molding. The inner wall 23 is provided along the outer wall 21a in a shape that avoids interference with the valve mechanism 4, and both sides of the double wall space are closed by partition walls 24. A blow-by gas inlet 25 is provided penetrating one lower end of the inner wall 23 and one end side of the internal space 22. From the blow-by gas inlet 25 to the internal space 22, as shown in FIG.
A mixture G of blow-by gas and lubricating oil mist is sent from the crankcase through the blow-by passage 10 of the cylinder block 2 and the cylinder head 5. In the breather chamber C, the lubricating oil is separated from the blow-by gas and the lubricating oil mist that are the mixture G, and those gas components are blow-by through the breather delivery pipe 27 from the blow-by gas outlet 26 provided at the other end side of the internal space 22. The blow-by gas is sent to a gas reduction device (not shown) and returned to the engine intake system to prevent its release into the atmosphere.

As shown in FIG. 2, the blow-by gas inlet 25 provided at one end side of the internal space 22, that is, one end side of the breather chamber C, is the uppermost portion of the inner wall 23 selected as the minute location of the lubricating oil mist. It is desirable to be provided in the lower part. The blow-by gas inlet 25 also serves as a return port for the lubricating oil separated from the lubricating oil mist, and the separated lubricating oil is returned to the oil pan 3 of the crankcase. The blow-by gas outlet 26 provided on the other end side of the internal space 22, that is, the other end side of the breather chamber C is an outer wall 21 which is an outer upper surface portion of the head cover 21.
The breather delivery pipe 27 extends to the blow-by gas returning device.

Also, a large number of recesses 2 are formed on the upper surface of the inner wall 23.
8 are provided, and the height of these numerous recesses 28 and the outer wall 21
A gap with a is formed as a gas passage 29. The gas passage 29 communicates with the above-mentioned blow-by gas outlet 26, and sends the gas component obtained by separating the lubricating oil from the blow-by gas and the lubricating oil mist to the blow-by gas reducing device. As described above, the lubricating oil separated from the lubricating oil mist (indicated by reference numeral g in the figure) is returned to the oil pan 3 from the blow-by gas inlet 25 along the side slope 23a of the inner wall 23. is there.

With the above-mentioned structure, in the apparatus of the embodiment, the internal volume of the breather chamber C has a shape in which the inner wall 23 does not interfere with the valve mechanism 4 and has a maximum space between the breather chamber C and the outer wall 21a. Obtained as the internal space 22. This is incomparable to the volume space in the conventional breather chamber 7 seen in FIG. 3, and it is possible to secure a compact and remarkably large volume space. Therefore, it is possible to efficiently separate the blow-by gas and the lubricating oil mist, which is the original function, without having to increase the size of the head cover 21.

Further, as is apparent from FIG. 2, in the cylinder head cover device of the embodiment according to the present invention, the entire planar shape can be formed in a curved shape in the longitudinal direction of the cylinder 30 arranging direction. That is, the outer wall 21 that is the outer shell of the head cover 21.
The a and the inner wall 23 can be formed in a curved shape, and as compared with the conventional head cover shown in FIG. 5, it means that the head cover having a constant cross-sectional area can secure the breather chamber C of the maximum volume in the embodiment. . This also means compactness from the perspective of the engine as a whole. Further, since the inner space 22 is formed between the double walls of the outer wall 21 a and the inner wall 23, the inner space 22
This has the great advantage of soundproofing engine noise.

Further, in the cylinder head cover device according to the embodiment of the present invention, in order to efficiently separate the blow-by gas and the lubricating oil mist, the breather chamber C having the maximum volume can be secured, and the breather chamber C is provided on the inner wall 23. A gas passage 29 extending from the blow-by gas inlet 25 to the blow-by gas outlet 26 provided on the outer wall 21a is formed by a gap formed by the heights of the plurality of recesses 28. Therefore, the separation of the gas is further promoted by passing the gas between the large number of recesses 28, and the separated lubricating oil is transmitted along the side slope portion 23a of the inner wall 23 and returned to the crankcase side oil pan 3.
There is also the advantage of minimizing the loss of lubricating oil.

[0016]

In the engine cylinder head cover device according to the present invention, the head cover and the breather chamber can be integrally formed into a double structure by blow molding, so that it is much more compact than the conventional assembly structure and the manufacturing cost is reduced. In addition, the internal volume of the breather chamber can be maximized with a shape that does not interfere with the valve operating mechanism without increasing the size of the head cover, and the original functions of blow-by gas and lubricating oil mist are efficiently Separation is possible.

[Brief description of drawings]

FIG. 1 is a perspective view of an embodiment of an engine cylinder head cover device according to the present invention.

FIG. 2 is a plan view of a partial cross section of the device of the embodiment.

FIG. 3 is a schematic cross-sectional view of a vehicle engine including a conventional head cover having a breather chamber assembled therein.

FIG. 4 is a perspective view of an assembled breather chamber in a conventional head cover.

FIG. 5 is a plan view of a conventional head cover.

[Explanation of symbols]

1 Engine 2 Cylinder Block 3 Oil Pan 4 Valve Mechanism 5 Cylinder Head 20 Cylinder Head Cover Device 21 Head Cover C Breather Chamber 21a Outer Wall 22 Inner Space 23 Inner Wall 24 Partition Wall 25 Blow-by Gas Inlet (also serves as Separate Lubricating Oil Return Port) 26 Blow-by Gas Outlet 27 Breather delivery pipe 28 Recess 29 Gas passage

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[Procedure amendment]

[Submission date] February 2, 1994

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] Claim 3

[Correction method] Change

[Correction content]

Claims (3)

[Claims] 1. A breather chamber is provided inside a head cover that is coupled to an upper part of a cylinder head of an engine and covers a valve operating mechanism. The breather gas and the lubricating oil mist from a crankcase are introduced and separated by integral molding of resin. A cylinder head cover device for an engine characterized by the above. 2. A breather chamber is provided with an outer wall of the head cover as an outer wall, and a double inner wall is provided inside the outer wall with a space avoiding interference with a valve operating mechanism.
It is constructed by closing both sides of the double wall space with partition walls.The blow-by gas and lubricating oil mist are introduced into the double wall space between the outer wall and the inner wall to discharge the separated blow-by gas and the lubricating oil to the crankcase. The cylinder head cover device for an engine according to claim 1, which is returned. 3. A blow-by gas inlet, which doubles as a separate lubricating oil return port leading to the crankcase, is provided at one end of the inner wall of the breather chamber in the longitudinal direction and at the lowermost portion thereof.
The engine cylinder head cover device according to claim 1, wherein a blow-by gas outlet is provided on the upper surface of the outer wall on the other end side in the longitudinal direction of the inner wall.