JPH08260930A - Lubricating oil feeding structure - Google Patents

Abstract

PURPOSE: To provide an aeration reducing mechanism on a cylinder head itself, to sufficiently reduce the aeration of the lubricating oil to be fed to the cylinder head, and to realize a structure to leave a part of the lubricating oil fed to the cylinder head in the middle of a lubricating feeding passage at a low cost when an engine is stopped. CONSTITUTION: In a lubricating oil feeding structure to feed the lubricating oil to a lubricating oil gallery 3 formed in a cylinder head 1 from its lower side through a lubricating oil feeding passage 4, an orifice chamber 5 to be communicated with a cam bearing 2 in the cylinder head 1 is provided. In addition, an orifice 6 is arranged at a lubricating oil inlet 5a of the orifice chamber.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lubricating oil supply structure, and more specifically, to a lubricating oil gallery formed in a cylinder head, the lubricating oil being supplied from the lower side thereof through a lubricating oil supply passage. Regarding supply structure.

[0002]

2. Description of the Related Art Conventionally, in engines of automobiles and motorcycles, various techniques have been proposed for separating air from the lubricating oil when supplying the lubricating oil from the cylinder block side to the cylinder head side. For example, an air separation device with an improved oil filter is installed in an engine, and this air separation device separates air from lubricating oil. Further, if all of the lubricating oil returns to the lower oil pan when the engine is stopped, there is a time lag in the supply of lubricating oil to the hydraulic tappet and the cam bearing in the cylinder head, which is not desirable for engine starting. Therefore, in order to solve this, various techniques have been proposed in which even if the engine is stopped, a part of the lubricating oil supplied to the cylinder head is not returned to the oil pan.
For example, a check valve may be used in the middle of the lubricating oil supply path, or a part of the lubricating oil may remain in the middle of the lubricating oil supply path by providing a height difference in the middle of the lubricating oil supply path.

[0003]

By the way, the conventional device for separating air from lubricating oil is generally large-scaled, and moreover, there has been a problem in the location where the separated air is discharged. In particular, a certain number of HLAs are arranged near the camshaft.
In an engine using a (hydraulic lash adjuster) or the like, reducing the aeration of the lubricating oil supplied to the cylinder head guarantees the operation of the HLA, so from the viewpoint of downsizing and weight reduction of the engine, It is preferable that the cylinder head itself has an aeration reduction mechanism. Further, in the conventional air separation device, when the amount of lubricating oil handled by the entire engine is large, it may not be possible to sufficiently reduce aeration.

Further, in the conventional check valve for leaving a part of the lubricating oil supplied to the cylinder head in the middle of the lubricating oil supply path when the engine is stopped, or in the method of providing a height difference in the middle of the lubricating oil supply path. , The structure becomes complicated,
As the number of man-hours for processing the cylinder head increases, the passage of the lubricating oil is unnecessarily lengthened, which makes it difficult to manufacture the cylinder head, resulting in an increase in manufacturing cost. The present invention has been made in view of the above circumstances, and it is possible to provide the cylinder head itself with an aeration reduction mechanism, and it is possible to achieve a sufficient reduction of aeration of the lubricating oil supplied to the cylinder head. Another object of the present invention is to provide a lubricating oil supply structure capable of inexpensively realizing a structure in which a part of the lubricating oil supplied to the cylinder head remains in the middle of the lubricating oil supply passage when the engine is stopped. .

[0005]

In the present invention, in order to achieve the above object, a lubricating oil gallery formed in a cylinder head is supplied with lubricating oil from a lower side thereof through a lubricating oil supply passage. In the oil supply structure, an orifice chamber communicating with the cam bearing in the cylinder head is provided in the middle of the lubricating oil supply path, and an orifice is provided at the lubricating oil inlet of the orifice chamber, so that the lubrication is performed by the orifice. The air is separated from the oil, and the air is discharged to the cam bearing side through the orifice chamber, while the lubricating oil from which the air is separated is supplied to the lubricating oil gallery through the lower space of the orifice chamber. It is configured to do.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the lubricating oil supply structure according to the present invention will be described below in detail with reference to the accompanying drawings. 1 to 3 show an embodiment of a lubricating oil supply structure according to the present invention applied to a DOHC engine or the like, for example. The lubricating oil supply structure of the present embodiment is the cylinder head 1 of the engine.
The lubricating oil is supplied to a valve mechanism (not shown) that opens and closes the intake valve and the exhaust valve, such as the cam bearing 2 and the tappet. Lubricating oil galleries 3 are formed in the cylinder head 1 of this embodiment. Lubricating oil is pressure-fed to the lubricating oil galleries 3 and 3 from the lower cylinder block (not shown) side through the lubricating oil supply passage 4.

An orifice chamber 5 whose upper portion opens toward the cam bearing 2 is provided in the middle of the lubricating oil supply path 4, and an orifice 6 is disposed on the lubricating oil inlet 5a side of the orifice chamber. In the example shown in detail in FIGS. 2 and 3, the orifice chamber 5 is communicated with the cam bearing 2 side via a passage 5b formed with its slightly upper portion facing upward. The lubricating oil supply passage 4 has a portion that contacts the lower portion of the orifice chamber 5 with the orifice chamber 5 as a boundary, that is, a vertical passage portion 4a to which the lubricating oil is sent upward from the cylinder block side, and a substantially right angle in the lateral direction from the lower portion. 1, and branched into left and right sides in FIG. 1 and divided into branch passage portions 4b and 4b communicating with the lubricating oil gallery 3 and 3. As a result, the orifice chamber 5 communicates with the left and right lubricating oil gallery 3, 3 via the lower spaces 5c, 5c located on both the left and right sides of the orifice 6 and the branch passage portions 4b, 4b. Also, the upper end 6a of the orifice 6
Are located higher than the lubricating oil galleries 3 and 3 on both sides.

Next, the operation of the lubricating oil supply passage structure in this embodiment will be described, and the structure thereof will be clarified. That is, the lubricating oil sent from the lower cylinder block side through the vertical passage portion 4 a of the lubricating oil supply passage 4 is ejected into the orifice chamber 5 through the orifice 6. At this time, the orifice 6 causes the air of the lubricating oil to become visible. Lubricating oil in which air is manifested goes upward due to its jetting force and is supplied to the cam bearing 2, and the air component of the lubricating oil is discharged to the outside via the cam bearing. Therefore, the lubricating oil containing less air can be sent to the lubrication-required portion of the cylinder head 1, the hydraulic pressure rises quickly, and the engine startability is improved. As a result, the lubricating oil with reduced air flows through the lubricating oil gallery 3 and 3 to the cylinder head 1 such as the HLA.
It is supplied to the lubrication required parts inside.

Here, when the engine is stopped, in this embodiment, the lubricating oil tries to return downward due to its gravity, but the lubricating oil existing at a position lower than the upper end 6a of the orifice chamber 5 orifice 6 is present. Are left in the lower space 5c of the orifice chamber 5, the branch passage portions 4b, 4b and the lubricating oil gallery 3, 3. That is, a part of the lubricating oil remains in the cylinder head 1 even if the engine is stopped.
For this reason, when restarting the engine that has been left stopped, a small amount of lubricating oil is supplied to the cylinder head 1, and engine startability is improved. In the present embodiment, the upper portion of the orifice chamber 5 is communicated with the cam bearing 2, but the present invention is not limited to this, and the point is that even if there is aeration, the cylinder may be opened if it is opened to the supply destination. The head 1 may be opened anywhere.

[0010]

As described above, according to the lubricating oil supply structure of the present invention, the lubricating oil is supplied from the lower side to the lubricating oil gallery formed in the cylinder head through the lubricating oil supply passage. In the lubricating oil supply structure described above, an orifice chamber communicating with the cam bearing in the cylinder head is provided in the middle of the lubricating oil supply passage, and an orifice is provided at the lubricating oil inlet of the orifice chamber.
Air is separated from the lubricating oil by the orifice, and the air is discharged to the cam bearing side through the orifice chamber, while the lubricating oil with separated air is lubricated through the lower space of the orifice chamber. Since the oil is supplied to the oil gallery, the following effects can be obtained.

That is, in the present invention, the lubricating oil supplied to the cylinder head side can be sufficiently aerated by the simple structure using the orifice. Therefore, the lubricating oil containing less air can be sent to each part of the cylinder head where lubrication is required, the hydraulic pressure rises quickly, and the engine startability is improved. Moreover, since the operation of the engine is not hindered even if the oil pressure or the oil amount is reduced, it is possible to reduce the size of the lubricating oil pump and reduce its mechanical loss. You can also

Further, since the aeration reducing mechanism of the present invention has a structure using the above-mentioned orifice, it can be easily formed in a small size. For this reason, it is easy to provide the cylinder head itself with an aeration reduction mechanism, and the degree of freedom in designing the cylinder head is increased without restricting the layout of the entire lubricating oil pump or lubricating oil gallery.

Further, in the present invention, since the upper end of the orifice is located higher than the lubricating oil gallery, a part of the lubricating oil supplied to the cylinder head when the engine is stopped is supplied to the lubricating oil. It can be left in the middle of the road, and the remaining amount of lubricating oil can be easily adjusted simply by changing the length of the orifice, so it is easy to handle engines with various displacements. And can be realized at low cost.

[Brief description of drawings]

FIG. 1 is a partial cross-sectional perspective view conceptually showing one embodiment of a lubricating oil supply structure according to the present invention.

FIG. 2 is a front view showing an embodiment of a lubricating oil supply structure according to the present invention.

3 is an enlarged sectional view showing a portion surrounded by a circle indicated by an arrow A in FIG.

[Explanation of symbols]

 1 Cylinder Head 2 Cam Bearing 3 Lubricating Oil Gallery 4 Lubricating Oil Supply Path 4a Vertical Path Section 4b Branch Path Section 5 Orifice Chamber 5a Lower Space 6 Orifice 6a Upper End

Claims (2)

[Claims] 1. A lubricating oil supply structure for supplying lubricating oil from a lower side thereof to a lubricating oil gallery formed in a cylinder head via a lubricating oil supply passage, wherein the cylinder is provided in the middle of the lubricating oil supply passage. An orifice chamber communicating with the cam bearing in the head is provided, and an orifice is provided at the lubricating oil inlet of the orifice chamber, whereby air is separated from the lubricating oil by the orifice and the air is passed through the orifice chamber. And to release the separated lubricating oil to the lubricating oil gallery through the lower space of the orifice chamber. 2. The lubricating oil supply structure according to claim 1, wherein the upper end of the orifice is located higher than the lubricating oil gallery.