JPH07139421A - Oil path structure of oil-cooled engine - Google Patents

Abstract

PURPOSE:To provide the oil path structure of an oil-cooled engine for eliminating increase in the number of part items, preventing increase of size of the engine and mechanical loss, and for cooling the engine properly and sufficiently. CONSTITUTION:A cooling oil nozzle 50a for ejecting cooling oil into an oil chamber, is provided in the oil chamber of a cylinder head 44 eccentrically to the inlet port side, and an oil returning path 57 for returning the cooling oil in the oil chamber to an oil reservoir, is opened eccentrically to an exhaust port side, while ribs 71a-71c are formed in an integrated manner with the cylinder head 44, on the channel of the cooling oil between the cooling oil nozzle 50a and the opening 57a of the oil returning path 57.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an oil passage structure for an oil-cooled engine in which a cylinder portion is inclined forward of a vehicle body and an exhaust port is provided forward.

[0002]

2. Description of the Related Art Conventionally, in an oil-cooled engine, cooling oil is supplied into the cylinder head and then returned to the crankcase as follows.

That is, in the engine 10 shown in FIG. 6, a cylinder portion 16 having a cylinder head 12 fixed thereon is fixedly attached to a crankcase 14, and cooling oil is supplied into an oil chamber 12a of the cylinder head 12. The passage is a cooling oil main passage 15a formed in the cylinder head cover 15. The oil chamber 12a and the crankcase 14 are connected by a pipe 18 which is separate from the cylinder portion 16, and the pipe 18 serves as an oil return passage. The oil returned through the pipe 18 once collects in the oil sump 14a below the crankcase 14,
It is sent to a cylinder head cooling system 24 by an oil pump 22 via an oil strainer 20. The cylinder head cooling system 24 includes a cooling oil main passage 15a.
Are connected to each other, and the tip of the oil main passage 15a opens into the oil chamber 12a. Also,
The sent cooling oil is combined with the oil lubrication system 26.
Also sent to. That is, the crankshaft bearing 32a passes through the oil cooler 28 and the oil filter 30.
It is sent to the camshaft 32b in the cylinder head 12 for lubrication.

The cooling oil supplied from the tip opening of the cooling oil main passage 15a into the oil chamber 12a flows along the inner wall of the oil chamber 12a above the cylinder bore as shown in FIG. And flows into the pipe 18.

[0005]

By the way, in the oil-cooled engine, the temperature rise of the cylinder head 12 and the cylinder portion 16 due to the combustion of the fuel in the cylinder bore is cooled by the cooling oil. The temperature of the cylinder head 12 does not uniformly rise as a whole, and there is a difference in distribution of temperature rise. For example, the temperature around the spark plug hole and the exhaust valve hole is likely to be higher than other temperatures. However, conventionally, there has been a problem in that no consideration has been given to the fact that cooling oil can be made to flow corresponding to the temperature rise distribution of the cylinder head as described above.

The present invention has been made in order to solve the above-mentioned conventional problems. In consideration of the temperature rise distribution of the cylinder head, the cooling oil can be flowed so as to correspond to the temperature rise distribution. (EN) Provided is an oil passage structure for an oil-cooled engine, which can improve cooling performance and can appropriately lower the combustion chamber wall temperature so as not to partially raise the temperature to improve output and durability. This is an issue.

[0007]

In order to solve the above-mentioned problems, the present invention has the following constitution. That is, the present invention is
In an oil-cooled engine in which an upper portion of a cylinder portion (40) is inclined forward and a lower portion is inclined rearward, and an exhaust port (42) is oriented forward, the cylinder head (4
An oil passage structure for supplying cooling oil into the oil chamber (44a) of (4) and returning the supplied cooling oil to the oil reservoir.
In the oil chamber (44a) of 4), a cooling oil nozzle (50a) for ejecting cooling oil into the oil chamber (44a) is arranged so as to be eccentric to the intake port side,
Further, an oil return passage (57) for returning the cooling oil in the oil chamber (44a) to the oil reservoir is biased to the exhaust port side and opened, and further, in the oil chamber (44a), Cooling oil nozzle (50
The cylinder head (44) is provided on the cooling oil flow path between the a) and the opening (57a) of the oil return passage (57).
A rib (71) is integrally formed with the oil passage structure of the oil-cooled engine.

[0008]

In the present invention, the upper portion of the cylinder portion (40) is inclined forward and the lower portion is inclined rearward, and the cylinder head (44) is cooled in the oil chamber (44a). An oil return passage (57) for returning the cooling oil in the oil chamber (44a) to the oil sump, in which a cooling oil nozzle (50a) for ejecting the cooling oil is disposed eccentrically to the intake port side.
Of the cylinder head (44), the cooling oil flows toward the exhaust port side after being supplied into the oil chamber (44a).
Can be cooled efficiently.

Further, the oil chamber (44a)
Inside, a rib (71) is formed integrally with the cylinder head (44) on the flow path of the cooling oil between the cooling oil nozzle (50a) and the opening (57a) of the oil return passage (57). Cylinder head (4
The cooling oil can be made to flow corresponding to 4) where the temperature rises easily, for example, in the center of the combustion chamber. The rib (71) also serves as a heat dissipation plate of the cylinder head (44), and the rib (71) serves as the cooling oil nozzle (50a) and the oil return passage (57) opening (57a). Since it is provided on the cooling oil flow path between them, more heat of the cylinder head (44) can be transferred to the cooling oil by hitting the rib (71) with the cooling oil. Thereby, the wall temperature of the combustion chamber can be lowered sufficiently.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. In this embodiment, the present invention is applied to an oil-cooled engine mounted on a motorcycle. FIG. 1 shows the overall construction of the motorcycle according to the embodiment, and FIGS. 2 to 5 show the detailed construction of the cylinder head 44 and the cylinder portion 40 of the oil-cooled engine.

As shown in FIG. 1, in the motorcycle, an upper portion of a cylinder portion 40 is inclined forward and a lower portion thereof is inclined rearward, and an exhaust port 42 is provided forward.
Oil-cooled engine 43 with cylinder overhead cam (OHC)
Equipped with. 2 is a detailed plan view of the cylinder head 44 of the oil-cooled engine with the cylinder head cover removed, and FIG. 3 is a sectional view taken along the line D-D of FIG.
2 is a sectional view taken along the line AA of FIG. 2, and FIG. 5 is a sectional view taken along the line BB of FIG.

As shown in FIGS. 2 to 4, in the oil-cooled engine of this embodiment, the cooling oil passage 50 for supplying the cooling oil into the oil chamber 44a of the cylinder head 44 and the oil chamber 44a. A cylinder has an oil passage structure having a cooling oil return passage 57 for returning the generated cooling oil to a crankcase (not shown) and a rib 71 for guiding the passage in the oil chamber 44a toward the spark plug hole 66 in the partition wall direction. It is included in the head 44.

That is, in the cylinder head 44, a spark plug hole 66 is provided at the center of a partition wall 64 covering the cylinder bore 54 shown by the broken line in FIG. Top 6 of hole 66
6a is formed with an insertion partition so that the spark plug body can be inserted therein. Also, this spark plug hole 6
A space is formed outside the partition wall of the upper portion 66a of 6 to form an oil chamber 44a. The upper part 66
The partition wall a is supported by the support wall 68.

Further, facing the FIG. 2, an exhaust valve tappet hole 70 is provided on the left side (on the exhaust side) of the spark plug hole 66, and
An intake valve tappet hole 62 is formed on the right side (on the intake side). In the vicinity of the tappet holes 62 and 70, cam journal support portions 72 that support the camshafts for driving the valves are formed. The cam journal support portion 72 is formed with a groove 72a through which lubricating oil passes. The space on the left side in FIG. 2 is a cam chain chamber 74 in which the cam chain is arranged.

Further, above the cylinder head 44, one cooling oil passage 50 and two lubricating oil passages are respectively connected to oil passages 48 to which oil is supplied from the same oil supply source (oil pump). 52, 5
2 is provided separately. In this case, the cooling oil passage 50 and the lubricating oil passages 52, 52 are both formed parallel to each other along the crankshaft. Further, the oil passage 48 is formed along the vertical direction of the cooling oil passage 50 and the lubricating oil passages 52, 52, and the cooling oil passage 50 and the lubricating oil passages 52, 5 are formed.
It is formed on the same plane as 2. In addition, as shown in FIGS. 2, 4, and 5, the cooling oil passage 50 is located near the spark plug hole 66 on the cylinder bore 54, on the intake valve tappet hole 62 side and on the side of the intake valve and the exhaust valve. The hole is formed so as to be located within the angle θ and to extend from the side surface on the side opposite to the cam chain chamber 74 as viewed in the crankshaft direction to near the cam chain chamber 74. A nozzle shaft is provided in the cooling oil passage 50 parallel to the cylinder axis (the same as the piston sliding direction axis) so as to face the oil chamber 44a at appropriate intervals and inject the cooling oil onto the upper surface of the cylinder head partition wall 64. Disposed injection nozzle 50a
Are formed. The nozzle axis of the injection nozzle 50a is not limited to being parallel to the cylinder axis as described above, and may be inclined at an appropriate angle with respect to the cylinder axis. In addition, reference numeral 6 in FIGS.
2a is an intake port, 70a is an exhaust port, and 72c is a cam journal.

The lubricating oil passages 52, 52 are camshafts (passing through the cam journal support portion 72) on the exhaust valve tappet hole 70 side and the intake valve tappet hole 62 side, respectively.
Is located in the vicinity of and outside of the cam chain chamber 74, and is provided from the side surface of the cam chain chamber 74 on the opposite side in the crankshaft direction to the vicinity of the cam journal support portion 72 on the cam chain chamber 74 side. The cooling oil passages 50 and the lubricating oil passages 52 can be formed through the pipes after the holes are formed in the cylinder head 44.

The oil distribution ratio between the cooling oil passage 50 and the lubricating oil passages 52, 52 can be set appropriately by appropriately selecting the diameters of the passages. Therefore, in the conventional oil-cooled engine in which the cooling oil passage and the lubricating oil passage are integrated, the cooling oil and the lubricating oil cannot be properly selected, whereas the engine according to the present embodiment has the supply side. Even though the oil passage is integrated, each oil can be appropriately and sufficiently supplied.

A partition wall 6 covering the cylinder bore 54 is also provided.
4 includes a cam chain chamber 74 and an oil chamber 4
A partition wall 64a for partitioning between the 4a is formed. Further, in the oil chamber 44a, ribs 71 (71a to 71c) are provided on the flow path of the cooling oil between the cooling oil nozzle 50a and the opening 57a of the oil return passage 57. One rib 71a is from the partition wall 64a, another rib 71b is from the central portion between the spark plug holes 66 and 66 outer peripheral walls 66a and 66a, and another rib 71c is the supply oil. It is a wall-shaped member for causing cooling oil to flow from the chamber wall 64a of the oil chamber 44a on the passage 48 side toward the outer peripheral wall 66a of the spark plug hole 66, and rises upward from the partition wall 64. In addition, it is provided integrally with the partition wall 64, that is, integrally with the cylinder head 44. As shown in FIG. 2, the rib 71 has a height substantially equal to the height of the opening of the injection nozzle 50a. Further, the rib 71 has an end portion on the side of the spark plug outer peripheral wall 66a, which is seen from the direction perpendicular to the cylinder axis, at the shaft 5 of the injection nozzle 50a.
It almost matches 0a1. The rib 71 is provided slightly closer to the exhaust valve hole 70 side than the line connecting the centers of the spark plug holes 66 when viewed from above the cylinder, whereby the cooling oil injected from the injection nozzle 50a is provided. Flow in the oil chamber 44a. . In addition, the spark plug outer peripheral wall 66 from the mounting side of the partition wall 64a.
The a-side end is formed so as to be slightly inclined toward the exhaust valve hole 70 side. Therefore, the rib 71 can smoothly flow toward the spark plug outer peripheral wall 60a without being delayed even if the flow of the cooling oil hits due to the inclination.

Further, the exhaust port 42 of the cylinder head 44
An oil return passage 57 for cooling, which opens the oil chamber 44a to the cylinder portion 40 side, is integrally formed in the side portion. In the embodiment, the opening of the cooling oil return passage 57 is sandwiched by the spark plug holes 66 and the injection nozzle 50a.
Is formed at a position substantially opposite to and in the vicinity of the exhaust valve hole 70. Further, there are four injection nozzles 50a and four cooling oil return passages 57, respectively. Further, the cooling oil return passage 57 has a substantially deformed rectangular cross section and its axis is along the piston sliding direction.
Has an opening on the lower surface of the cylinder head 44. However, the configuration of the cooling oil return passage 57 is not limited to this, and can be formed in an appropriate cross section and axis.

The operation of the embodiment will be described below. The oil flow of the oil-cooled engine of the embodiment will be described with reference to FIGS. 2 to 5.

As shown in FIG. 2, common oil for cooling and lubricating is supplied to the oil passage 48 from an oil pump (not shown). The supplied oil passes through the oil passage 48 and then flows into the cooling oil passage 50 and the lubricating oil passage 52 separately. Cooling oil passage 5
No. 0 oil is used as cooling oil for each injection nozzle 50a.
Is injected into the oil chamber 44a.

That is, the cooling oil is injected toward the intake valve hole 62 side of the upper surface of the cylinder bore upper partition wall 64, and is directed toward the exhaust side on the upper partition wall 64, as shown by the arrow in FIGS. Flowing. This oil flow is rib 71
The direction is changed to the direction of the spark plug hole 66, and the spark plug hole 66 passes near the side surface of the outer peripheral wall 66a. Further, the cooling oil flows into the cooling oil return passage 57 so as to wrap around the rib 71.

Therefore, the cooling oil flowing into the cooling oil return passage 57 can sufficiently cool the side portion of the exhaust port 42 of the cylinder head 44 which is apt to be highly heated when passing through the cooling oil return passage 57. In addition, in the said Example, although the ribs 71a-71c are comprised by the outer shape of the plate shape, this invention is not limited to this, and can provide a curved surface or unevenness on the surface. The oil distributed from the oil passage 48 on the supply side to the lubricating oil passage 52 is supplied to the groove 72 a of the cam journal support portion 72.

[0024]

As described above, according to the present invention,
Considering the temperature rise distribution of the cylinder head, the cooling oil can be made to flow correspondingly to improve the cooling performance by oil cooling, and it is appropriate not to raise the combustion chamber wall temperature partially. It is possible to improve the output and the durability by lowering the value.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram of a motorcycle equipped with an engine according to an embodiment of the present invention.

FIG. 2 is a plan view of a cylinder head of the engine according to the embodiment.

3 is a cross-sectional view taken along the line DD of FIG.

4 is a cross-sectional view taken along the line BB of FIG.

5 is a cross-sectional view taken along the line BB of FIG.

FIG. 6 is a configuration example of a conventional oil-cooled engine.

FIG. 7 is an explanatory diagram of another configuration example of a conventional oil-cooled engine.

[Explanation of reference numerals] 40 cylinder portion 42 exhaust port 44 cylinder head 44a oil chamber 50 cooling oil passage 50a injection nozzle 54 cylinder bore 57 cooling oil return passage 57a opening 62 intake valve hole 62a intake port 64 cylinder head partition 64a partition wall 64b Oil chamber chamber walls 71, 71a, 71b Ribs

Claims (1)

[Claims] 1. A cylinder head (44) in an oil-cooled engine in which an upper part of a cylinder portion (40) is inclined forward and a lower part is inclined rearward and an exhaust port (42) is provided forward. An oil passage structure for supplying cooling oil into the oil chamber (44a) of the cylinder head (44a) and returning the supplied cooling oil to the oil reservoir.
In a), a cooling oil nozzle (50a) for ejecting cooling oil into the oil chamber (44a) is eccentrically arranged toward the intake port side, and the oil chamber (44)
An oil return passage (57) for returning the cooling oil in a) to the oil sump is biased to the exhaust port side and opened, and further, in the oil chamber (44a), the cooling oil nozzle (57) is provided. 50a) and oil return passage (5
An oil passage structure for an oil-cooled engine, characterized in that a rib (71) is formed integrally with the cylinder head (44) on a cooling oil flow path between the opening (57a) and the opening (57a).