JPH0115849Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a blow-by gas passage structure in a V-type engine in which cylinders are arranged in a V-shape.

[Prior Art] In an engine, blow-by gas leaking from the combustion chamber into the crank chamber is usually oil-removed at the upper part of the head cover, and then returned to the intake system and combusted again in the combustion chamber. When blow-by gas treatment is performed above the head cover, a passage is required for the recovered oil and the oil used to lubricate the equipment above the head to quickly return to the oil pan. In the case of a V-type engine, the oil return passages must be located along the outer surfaces of the left and right banks in order to receive the flowing oil because the cylinders are inclined to the left and right. (For example, Japanese Patent Application Laid-open No. 183510/1983). This oil return passage usually also serves as a blow-by gas passage, with blow-by gas rising from the crank chamber to the head cover interior space, and oil flowing down from the head cover interior space into the crank chamber.

[Problems to be solved by the invention] In such a blow-by gas passage structure, when the oil level in the oil pan becomes uneven, such as when the vehicle turns or when going up or down a slope, the oil return passage The lower end of the oil may fall below the oil level, blocking the oil return passage. For this reason,
A pressure difference is created between the head cover interior space and the crank chamber, which not only worsens oil return but also poses a risk of oil being discharged from the blow-by gas passage into the intake system.

Furthermore, during high-speed operation, the oil surface becomes uneven due to wind pressure caused by the rotation of the balance weight of the crankshaft, and the same problem as described above occurs on the uneven head side.

Further, a similar problem occurs even when a blow-by gas outlet is provided on the side surface of the block.

In order to solve the above-mentioned problems, the present invention is designed to prevent the blow-by gas passage from being blocked by the oil level even if the oil level in the oil pan is uneven in the V-type engine. It is an object of the present invention to provide a blow-by gas passage structure that does not cause oil discharge.

Note that since mist-like oil flows into the blow-by gas passage along with the blow-by gas, a passage structure is desired that prevents this flowing oil from being discharged to the outside as much as possible.

[Means for Solving the Problems] To achieve this objective, the blow-by gas passage structure of the present invention consists of the following. That is,
In a V-type engine, the blow-by gas passage is
The blow-by gas passage has one end that opens into the top wall of the crank chamber above the crankcase and an intermediate position between the left and right banks, and the other end that is directly open to the atmosphere or directly connected to the intake system. A blow-by gas passage structure characterized in that an oil separator chamber formed by a plurality of reinforcing ribs connecting left and right banks is interposed in the middle.

[Function] In this blow-by gas passage structure, since the blow-by gas passage does not communicate with the head cover interior space, an oil return passage is used to return the oil accumulated in the oil reservoir at the bottom of the head cover interior space into the crankcase. The blow-by gas passage is not located on the side of the crankcase, so even if the oil in the oil pan becomes uneven when the vehicle turns, climbs or descends a hill, the blow-by gas passage will not be blocked by the oil. It won't be blocked. Therefore, oil discharge cannot occur due to a pressure difference that may occur if the blow-by gas passage is blocked. These ensure stable blow-by gas discharge and prevention of increased oil consumption.

Further, since the oil that has flowed into the blow-by gas passage is separated by an oil separator chamber provided in the middle of the blow-by gas passage, the amount of oil discharged to the atmosphere or the intake system can be suppressed to an extremely small amount.

This oil separator chamber is formed using multiple reinforcing ribs that connect the left and right banks, so the empty space between the left and right banks can be used effectively, and multiple oil separator chambers can be arranged. becomes.

[Embodiments] Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.

1 and 2 show a V-type engine equipped with a blow-by gas passage according to the present invention. In the figure,
A crankcase 1 has a crank chamber 2 inside. Cylinder blocks 3 and 4 stand diagonally upward in a V-shape on the left and right sides of the crankcase 1. Pistons 5 and 6 are slidably installed in the cylinder bores in the cylinder blocks 3 and 4.
They are connected to a crankshaft 9 via connecting rods 7 and 8, respectively. 10 indicates the balance weight of the crankshaft.
A cylinder head is installed above the cylinder blocks 3 and 4, and a head cover is installed above it.
These are omitted from illustration. Oil return passages 11 and 12 are provided along the outer surfaces of the cylinder blocks 3 and 4 to return oil from the head cover interior space to the crank chamber 2. Oil pan 1 is on the bottom of crankcase 1.
3, and oil 14 is inside the oil pan 13.
is accumulated. Of these, the left and right cylinder blocks 3, 4, cylinder heads, and head covers constitute left and right banks 15, 16, respectively.

Above the crankcase 1 and on the left and right banks 1
Blow-by gas passage 1 is located between 5 and 16.
7, the lower end of which opens into the crank chamber 2. An oil separator chamber 18 is connected to the upper part of the blow-by gas passage 17, and an oil separator 19 is provided in the oil separator chamber 18 to separate oil from the blow-by gas.
However, since the oil separator chamber 18 itself has a separator function by colliding with the wall surface of the blow-by gas, there is no need to provide a special oil separator 19. In addition, the blow-by gas passage 17
When the separator chamber 18 is formed by making a concave groove in the cylinder block and covering it with a plate, it may consist of a hole bored in the plate. A blow-by gas outlet 20 is formed on the downstream side of the oil separator chamber 18, from which the blow-by gas is directly released to the intake system or the atmosphere without going through the head cover interior space. When connected to the intake system, it does not go through the space inside the head cover.

The oil separator chamber 18 is formed in a portion that was previously an empty space between the left and right banks 15 and 16 of the V-type engine. In the illustrated example, the oil separator chamber 18 is formed using the portions of the left and right banks 15 and 16 partitioned by reinforcing ribs 21, and the ribs 21 are a component of the oil separator chamber 18. In FIG. 2, the space between the left and right banks 15 and 16 is partitioned into four by reinforcing ribs, and oil separator chambers 18 are formed in the two central spaces, and each of the oil separator chambers 18 is A case is shown in which a blow-by gas passage 17 is provided in the middle.

Next, the operation of the above device will be explained. First, since the blow-by gas passage 17 or its communication portion does not open into the head cover interior space, the oil accumulated in the oil reservoir on the bottom of the head cover interior does not flow down through the blow-by gas passage 17, and the blow-by gas and return oil flow through separate passages. That is, the blow-by gas passes through the blow-by gas passage 17,
The oil flows from the crank chamber 2 to the blow-by gas outlet 20 or directly to the intake system (without going through the head cover interior space), and the oil flows to the oil pan 13 through the oil return passages 11 and 12. Therefore, they do not interfere with each other.

In this state, if the oil shifts to one side due to centrifugal force or the tilt of the vehicle when the vehicle turns, climbs or descends a slope, or if the oil shifts to one side due to the rotation of the balance weight 10 at high speed, the oil level If the oil return passage 11 or 12 is tilted beyond the position indicated by the two-dot chain line A in FIG.
is not occluded. Therefore, the flow of blow-by gas is stable. In addition, due to the difference in gas pressure caused by the blockage, oil flows to the blow-by gas outlet 20.
Phenomena such as discharge from the head cover or blowing out into the space inside the head cover cannot occur. Further, since the bottom surface of the head cover inner space is not opened, the blow-by gas passage 17 will not be blocked due to unevenness of oil there.

Even when looking at the above passage structure from the perspective of space design, the space between the left and right banks 15 and 16 of the V-type engine, which was previously a vacant space, is effectively used, so that the engine does not become larger. Considering that in the conventional structure where the oil separator chamber is provided only inside the head cover, the engine size increases due to securing the volume of the oil separator chamber, the use of the empty space between the left and right banks makes it possible to reduce the engine size. . Moreover, since the oil mist is separated when passing through the blow-by gas passage 17 and/or the oil separator chamber 18, the oil mist separation effect is promoted. Further, since the wall of the oil separator chamber 18 can also be formed by integral casting so as to serve as reinforcing ribs, it is also possible to reduce costs.

[Effects of the Invention] As is clear from the above explanation, the blow-by gas passage structure of the present invention provides the following effects.

The blow-by gas passage is opened in the uppermost wall of the crank chamber between the left and right banks, and is dedicated to the blow-by gas.
The conventional problem of blockage of the blow-by gas passage due to oil level fluctuations in the oil pan and head cover space is eliminated, and the problem of increased oil consumption is also eliminated.

In addition, an oil separator chamber formed by a plurality of reinforcing ribs connecting the left and right banks is interposed in the middle of the blow-by gas passage, so the empty space between the left and right banks can be used effectively. , and a plurality of oil separator chambers can be arranged. As a result, it is possible to eliminate the need to increase the size of the engine, and to improve the ability to separate blow-by gas and oil.

[Brief explanation of the drawing]

FIG. 1 is a partial sectional view of a V-type engine equipped with a blow-by gas passage structure according to an embodiment of the present invention;
FIG. 2 is a plan view of the V-type engine shown in FIG. 1. 1... Crank case, 2... Crank chamber, 2
a...Top wall part, 3, 4...Cylinder block,
5, 6...Piston, 9...Crankshaft,
10... Balance weight, 11, 12... Oil return passage, 13... Oil pan, 14... Oil, 15, 16... Left and right banks, 17... Blow-by gas passage, 18... Oil separator chamber,
19...Oil separator, 20...Blow-by gas outlet, 21...Reinforcing rib.

Claims (1)

[Scope of utility model registration request] In a V-type engine, the blow-by gas passage has one end opening into the top wall of the crank chamber above the crankcase and midway between the left and right banks, and the other end opening directly to the atmosphere or connecting directly to the intake system. 1. A blow-by gas passage structure, characterized in that an oil separator chamber formed by a plurality of reinforcing ribs connecting left and right banks is interposed in the middle of the blow-by gas passage.