Cylinder Head Cover

Field Of Invention

The invention relates to an engine crankcase ventilation system. More particularly, the invention relates to a cylinder head cover construction facilitating oil separation from blow-by gases.

Background of the Invention

Cylinder head covers serve to seal off the cylinder head space from the outside of the engine. As a result of operation of the internal combustion engine, blow-by gases from the combustion process and oil droplets from the lubricant system of the engine are present inside the cylinder head. These quantities of gases and liquid present in the cylinder head space are usually passed through separating devices and returned to the intake area and/or the oil circuit. Such separating devices for separating the oil components of the crankcase gas are usually mounted in the immediate vicinity of the cylinder head cover or, ideally, they are integrated into the cylinder head cover.

Conventional cylinder head cover designs comprise baffle plate construction wherein the blow-by gases pass through them, and the separated oil is collected in drain pots. Effectiveness of oil separation and oil draining are found to be less in such constructions. In another conventional arrangement, the orifice plate (with or without impactor wall) provides small holes for gases to leave allowing further oil separation.

Such conventional cylinder head cover designs result in improper oil separation from blow-by gases and too much of oil carry over from the cylinder head cover, which results in excess engine oil consumption. Also, contamination of air intake duct occurs. Such a design also requires the presence of a cyclonic separator adding to the complexity of the arrangement, including maintenance related problems.

Objects of the Invention
It is an object of the invention to provide an improved cylinder head cover for the cylinder head of an internal combustion engine.

It is a further object of the invention to improve the engine oil separation from blow by gases and eliminate the need for a cyclonic separator from the ventilation system, thus eliminating the problems associated with the prior art.

Summary of the Invention

The invention provides a cylinder head cover for encasing a cylinder head of an internal combustion engine. The module inside the cylinder cover comprises a set of walls having holes, preferably on the upper part of the walls. According to this construction, blow-by gases mixed with oil mist enters into the inlet bay area of the module inside the cylinder cover, thereby impinging on the bay walls. Blow-by gases escape through the holes in the bay walls and exit through an exit bay area. The oil component of the mixture is retained and drained through appropriate drain holes provided proximal to the bay walls.
In a preferred embodiment an oil drain trench is provided proximal to each of the bay walls, such that the oil particles that are separated from the blow-by gases are properly drained.

The oil trench may be preferably designed based on the engine inclination such that the oil is collected on only one side proximal to the bay walls and drained out through the drain holes.

Statement of Invention
Accordingly, the invention relates to a cylinder head cover for covering the cylinder head of an internal combustion engine, comprising a module inside the cover, said module having a plurality of walls arranged parallel to each other to form alternate inlet and exit bays, each wall having a plurality of holes provided on perimetric surface of the walls.

Brief Description of the drawings

The drawings being referred herein are for the purpose of illustrating a preferred embodiment of the invention only, and not for the purpose of limiting the same. The invention will be explained in greater detail hereinafter with reference to an illustrative embodiment shown in the accompanying drawings, in which:

Figure 1 shows the exploded view of a cylinder head cover and a module inside the cover according to the present invention;

Figure 2 shows the perspective view of the module inside the cylinder head cover according to the present invention;

Figure 3 shows the blow-by gas motion in the cylinder head cover according to this invention.

Figure 4 shows the drain slots for individual bays inside the module; i Figure 5 shows the drain cover according to this invention; and

Detailed Description of the Invention

Figure 1 shows the exploded view of the present invention. A module (2) is provided inside a cylinder head cover (10). The module (2) may either be > separately formed and suitably arranged within the cylinder head cover (10) or integrally formed together with the cylinder head cover (10). A drain cover (7) is provided at the bottom of the module (2).

The perspective view of the module (2) is illustrated in figure 2. The module (2) comprises a plurality of bay walls (4) arranged adjacent to each ) other with predetermined spacing. The bay walls (4) are arranged parallel to each other such that they form alternate inlet and exit bays. The bay walls (4) comprise a plurality of holes (6) arranged on the peremetric surface of the wall (4). Preferably, the holes (6) are provided closer to the upper part of the bay walls (4).

As illustrated in figure 3, blow-by gases mixed with oil enters into the inlet bays (3) and impinges on the bay walls (4) and passes through the holes (6) provided on the bay walls (4). The direction of flow of the blow-by gases from the inlet (I) to the exit (E) is indicated by arrows. Since the blow-by gases and oil mixture pass through the plurality of bay walls (4) with holes (6), the oil component in the mixture is effectively separated from the gases. The oil-free blow-by gases are allowed to flow through the exit bays (5) towards the exit (E) of the cylinder head cover (10).

The oil separated from the blow-by gases are drained through appropriate drain holes provided at an appropriate position in the cylinder head cover (10). Figure 4 shows the drain slots (11) provided on the drain cover (7). Each bay in the module (2) has a corresponding drain slot (11). Alternatively, a common drain slot for all the bays in the module can also be envisaged and would be within the scope of this invention.

Oil drain trenches (13), as illustrated in figures 1 and 5, are provided proximal to the bay walls (4) such that the oil flowing in a laminar manner from the bay walls (4) are collected and retained in the oil trench (13) before it drains through the drain holes (11). The oil trenches (13) are preferably designed based on the engine inclination such that the oil is collected on only one side proximal to the bay walls (4) and drained out through the drain holes (11).

Engine oil separation from blow-by gases accomplished by this invention leads to elimination of the cyclonic separator from the engine ventilation system since the oil consumption is well under control even without the cyclone separator, Removal of the cyclone separator from the ventilation system results in simpler engine packaging on the vehicle.

While the above paragraphs explain the preferred embodiment of the invention, it is apparent that numerous modifications and variations can be made without departing from the scope and spirit of this invention. It is therefore intended that this invention be limited only as indicated in the appended claims.

WE CLAIM

1. A cylinder head cover (10) for covering the cylinder head of an internal combustion engine, comprising a module (2) inside the cover, said module having a plurality of walls (4) arranged parallel to each other to form alternate inlet and exit bays (3, 5), each wall having a plurality of holes provided on perimetric surface of the walls (4).

2. The cylinder head cover as claimed in claim 1, wherein the module is integrally formed with the cylinder head cover.

3. The cylinder head cover as claimed in claim 1, wherein the plurality of holes are provided at upper portions of the walls.

4. The cylinder head cover as claimed in claim 1, wherein oil drain holes are provided at an appropriate position proximal to each inlet bay.

5. The cylinder head cover as claimed in claim 1, wherein an oil trench is provided proximal to each bay wall (4).

6. The cylinder head cover as claimed in claim 5, wherein the oil trench is designed based on the engine inclination with respect to the vehicle.

7. An internal combustion engine comprising the cylinder cover as claimed in the preceding claims.