JPS61175212A - Lubricating oil return passage device in internal-combustion engine - Google Patents

Abstract

PURPOSE:To make it possible to return oil with no air being mixed into oil, by forming an oil receiving surface opposing the opening end of a head side oil return passage, in the upper section of a block side oil return passage, and by making the receiving plate continuous to the inner wall surface of the block side oil return passage. CONSTITUTION:An oil return passage P1 for returning oil which has lubricated mainly a valve drive mechanism 24 into an oil sump 21, is formed in each of left and right corner sections on the exhaust side of an engine body E. This return oil passage P1 is composed of a head side oil return passage 331 and a block side oil return passage 341 with the upper end of the passage 331 and the lower end of the passage 341 being opened to a valve drive chamber 22 and a crank chamber, respectively. Further, the upper end of the passage 341 is laterally enlarged in an oval shape and is opened to the deck surface of a cylinder block 1, and a substantially flat oil receiving surface 361 opposing the lower opening end of the passage 331 is formed in the above-mentioned upper section. Further, this receiving surface 361 is made to be continuous to the inner wall surface of the passage 361.

Description

DETAILED DESCRIPTION OF THE INVENTION A0 Object of the Invention (1) Industrial Application Field The present invention relates to an oil return passage device for returning oil after lubrication to an oil reservoir.

(2) Prior Art Conventionally, a cylinder block and a cylinder head constituting an engine body are provided with oil return passages on the block side and the head side that communicate with each other, and the oil that lubricates the valve mechanism, etc. in the upper part of the engine body is supplied to the cylinder block and the cylinder head. 2. Description of the Related Art A lubricating oil return passage device for an internal combustion engine is already well known, in which oil is returned to an oil sump via head-side and block-side oil return passages.

(3) Problems to be Solved by the Invention By the way, in the conventional oil return passage device, the return oil passes through the head side passage and the block side passage and falls straight into the oil reservoir, so the oil splashes etc. There is a problem that air may be trapped in the returned oil.

The present invention has been made in view of the above-mentioned circumstances, and the return oil is transmitted along the inner wall surface of the block side oil return passage and falls quietly and cleanly, thereby reducing air entrapment in the oil as much as possible. It is an object of the present invention to provide a return passage device for lubricating oil in an internal combustion engine that has a simple structure and that can be used in an internal combustion engine.

B0 Structure of the Invention (υ Means for Solving the Problems According to the present invention, in order to achieve the above object, a block side oil return passage is formed in the cylinder block, and a head is formed in the cylinder head on the cylinder block. The side oil return passages are laterally carved and communicated with each other, and the upper part of the block side oil return passage is formed with an oil receiving surface facing the opening lower end of the head side oil return passage,
This oil receiving surface is connected to the inner wall surface of the block side oil return passage.

(2) Function The return oil on the cylinder head that has lubricated the valve mechanism, etc. can drip quietly along the inner wall surface of the block-side oil return passage without trapping air, and be returned to the oil reservoir. .

(3) Examples An embodiment of the present invention will be described below with reference to the drawings.

In FIG. 1, E is the engine body of an in-line multi-cylinder internal combustion engine, which includes a cylinder block 1 and a gasket 3 on top of the cylinder block 1.
The cylinder head 2 is connected to the cylinder head 2 by a connecting bolt 4 via the cylinder head 2. An oil pan 6 is attached to the open lower surface of the cylinder block 1 with a sealing material 5 interposed therebetween.

The cylinder block 1 consists of a cylinder part 11 and a crankcase part 1□, a plurality of cylinder bores 7 are arranged in series in the cylinder part 1°, and a cylinder liner 8 is cast into each cylinder pore 7, into which a piston is inserted. 9 is slidably fitted. A crankshaft 14 is rotatably supported by a plurality of journal walls 10 formed in the crankcase portion 12 and bearing caps 11 respectively coupled to the lower surface of the journal walls 10 .
are joined together by. The crankshaft 14 and the piston 9 are connected via a connecting rod 15.

A buckle plate 1 is provided on the lower surface of the bridge member 12.
6 is fixed with mounting bolts 17, and oil return holes 18 and 19 are bored in this baffle plate 16. The baffle plate 16 partitions the crank chamber 20 and the oil reservoir 21 in the oil pan 6, and acts to prevent the crankshaft 14 from hitting the oil surface when the oil in the oil reservoir 21 is rippled.

A valve train chamber 22 is formed on the cylinder head 2,
This valve operating chamber 22 is equipped with two valve operating camshafts 23.
An HC type valve mechanism 24 is housed therein, and the valve mechanism 24 operates intake and exhaust valves 25 and 26 that are slidably supported on the cylinder head 2 at predetermined timing, thereby opening and closing the intake and exhaust valves of the combustion chamber 27. Open and close ports 28 and 29. Combustion chamber 2
An ignition plug 30 is provided in the center of 7.

A head cover 32 is attached onto the cylinder head 2 via a sealing material 31, and the head cover 32 covers the valve operating chamber 22.

At the left and right corners of the exhaust side of the engine body E, there are oil return passages p2. p2 should be established. The left oil return passage P communicates with the head side oil return passage 33. as clearly shown in FIG. and block side oil return passage 34. The head side oil return passage 33. The upper end opens into the valve train chamber 22 as shown in FIG. 1, and the lower end opens into the cylinder head 2.
It is opened on the bottom surface of. On the other hand, block side oil return passage 3
The upper part of 41 expands laterally into an oval shape and is opened to the deck surface of cylinder block 1, and is connected to head side oil return passage 33.41 through gasket hole 35. It communicates with the lower end of the opening. Therefore, the block side oil return passage 34. In the upper part of the head side oil return passage 33. A substantially flat oil receiving surface 36 facing the lower end of the opening. is formed, and a head side oil return passage 33. The oil flowing through this oil receiving surface 36. It is now available at .

Block side oil return passage 34. The lower end of the crankshaft is communicated with a crank chamber 20 as shown in FIG.

Further, the oil return passage P2 on the right side also communicates with each other, as clearly shown in FIG.
2 and a block side oil return passage 342,
An upper end of the head-side oil return passage 332 is opened to the valve operating chamber 22, and a lower end thereof is opened to the lower surface of the cylinder head 2. On the other hand, the upper end of the block-side oil return passage 342 expands laterally into an elliptical shape, opens at the deck surface of the cylinder block 1, and communicates with the opening lower end of the head-side oil return passage 33□ via the gasket hole 352. A substantially flat oil receiving surface 362 facing the opening lower end of the head side oil return passage 332 is also formed at the upper end of the block side oil return passage 34 □, and the oil flowing through the head side oil return passage 332 is temporarily transferred to this oil receiving surface. You can receive it at 362. A lower end of the block-side oil return passage 342 communicates with the crank chamber 20. Therefore, the head side and block side oil return passages 33 of the left oil return passage P shown in FIG.
．． .

gasket hole 35 . is the head side oil return passage 33. and the fifth opening.
The gasket hole 352 of the right oil return passage P2 shown in the figure, which is interposed between the head side and block side oil return passages 33□, 342, is aligned with the opening upper end of the block side oil return passage 34□.

Note that 37 in the figure is an oil filter.

Next, the operation of one embodiment of the present invention will be explained.

When the engine is operated now, the oil in the oil reservoir 21 is sucked up by an oil pump (not shown) as usual, and is forcibly supplied to each lubricated part of the engine to lubricate the core part.

On the cylinder head 2, the oil that mainly lubricates the valve train 24 in the valve train chamber 22 is diverted from the top of the cylinder head 2 to the left and right oil return passages P1, P2, and these passages p, , p, The oil is returned to the oil reservoir 21 through the As shown in Fig. 4.5, the left and right oil return passages P,,P.

The oil flowing into the head side oil return passage 33. ,
-332 to block side oil return passage 34. ．． 34°, the block side oil return passage 34. .

Oil receiving surface 36 formed on the upper part of 342. ．． At 36 degrees,
Therefore, once received, the block side oil return passage 34. ．． The oil flows down along the inner wall surface of 34□, drips quietly into the crank chamber 20, falls on the buckle plate 16, and is returned to the oil reservoir 21 through the oil return hole 18 opened there. Therefore, the proportion of air trapped in the oil during the process of returning to the oil reservoir 21 through the left and right oil return passages P, , P is reduced.

C0 Effects of the Invention As is clear from the above embodiments, according to the present invention, a block-side oil return passage formed in the cylinder block and a head-side oil return passage formed in the cylinder head on the cylinder block. are laterally fibrillated to communicate with each other, and the upper part of the block side oil return passage forms an oil receiving surface facing the opening lower end of the head side oil return passage, and this oil receiving surface is connected to the block side oil return passage. Since it is continuous with the inner wall surface of the return passage, when the return oil on the cylinder head passes through the head side and block side oil return passages and returns to the oil reservoir, the oil is received by the oil receiving surface and flows through the block side oil return passage. The oil can be dripped quietly and returned to the oil reservoir without bouncing along the inner wall surface, and air entrapment in the returned oil can be reduced as much as possible, improving lubrication efficiency.

[Brief explanation of drawings]

The drawings show one embodiment of the present invention; FIG. 1 is a longitudinal sectional view of the engine main body along the line 1-71 in FIG.
Figure 3 is a plan view of the cylinder block taken along line I71-m in Figure 1;
FIG. 4 is an enlarged sectional view taken along line 2-IV in FIG. 2, and FIG. 5 is an enlarged sectional view taken along line 2--IV in FIG. 1... Cylinder block, 331, 33□... Head side oil return passage, 34□, 342... Block side oil return passage, 36. ．． 362... Oil receiving surface patent applicant Honda Motor Co., Ltd. Figure 4 JP-A-6L-175212 (7) Figure 5

Claims (1)

[Claims] A block-side oil return passage formed in the cylinder block and a head-side oil return passage formed in the cylinder head on the cylinder block are communicated with each other with a difference in the lateral direction, and the upper part of the block-side oil return passage Lubricating oil for an internal combustion engine, characterized in that an oil receiving surface facing the opening lower end of the head side oil return passage is formed, and this oil receiving surface is continuous with the inner wall surface of the block side oil return passage. return passage.