JP4380903B2 - Breather structure for internal combustion engines - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a structure of a breather for an internal combustion engine.
[0002]
[Prior art]
Conventionally, a breather that discharges blow-by gas generated during driving of an internal combustion engine into the atmosphere is generally attached to the upper part of the cylinder head and is guided downward by a pipe and opened to the atmosphere. However, when the internal combustion engine becomes larger and the structure of one cylinder and one cylinder head increases, it is necessary to provide as many breathers as the number of cylinders, which makes the structure complicated, requires a lot of space, and costs. There was a problem of becoming higher. Therefore, a method of discharging blow-by gas from a crankcase in which blow-by gas accumulated in the cylinder head finally gathers has been used.
[0003]
FIG. 4 is a partial front sectional view of a V-type internal combustion engine showing an example of a breather device 30 mounted on a conventional crankcase. A separation chamber 31 for separating oil and gas is attached to the upper portion of the crankcase 1, and the lower side surface of the crankcase 1 and the lower portion of the separation chamber 31 are connected by a connecting pipe 32 and an oil pipe 33 to communicate with each other. A discharge pipe 34 is attached to the upper part of the separation chamber 31, and a baffle plate 35 is provided inside. An oil reservoir 2 is attached to the lower part of the crankcase 1.
[0004]
When the internal combustion engine is driven, blow-by gas in the crankcase 1 is introduced into the separation chamber 31 through the connecting pipe 32, and oil and gas are separated by the baffle plate 35. The separated oil is returned to the crankcase 1 through the oil pipe 33, and the gas is discharged from the discharge pipe 34 to the atmosphere.
[0005]
[Problems to be solved by the invention]
However, in the above configuration, when the pressure of the blow-by gas is high, the oil may pass through the separation chamber, and the oil may be ejected together with the gas from the discharge pipe.
[0006]
The present invention has been made paying attention to the above problems, and does not eject oil, has a simple structure, does not require a large space, and is a low-cost internal combustion engine breather structure. The purpose is to provide.
[0007]
[Means, actions and effects for solving the problems]
In order to achieve the above object, according to a first aspect of the present invention, there is provided a breather structure mounted on an internal combustion engine, wherein a first separation chamber that separates oil in blow-by gas discharged from a side surface of a crankcase, and a first separation An oil return means for returning the separated oil attached to the chamber to the oil reservoir at the lower part of the crankcase, and a second separation located above the first separation chamber and separating the oil and the gas in the blow-by gas A second pipe that connects the chamber, the connecting pipe that connects the first separation chamber and the second separation chamber, the second separation chamber and the oil reservoir, and returns the oil separated in the second separation chamber to the oil reservoir. an oil pipe, attached to the second separation chamber, possess an outlet for discharging the separated gas, a second oil pipe for returning the separated oil to the oil reservoir, in the crankshaft direction of the internal combustion engine Before and after the second separation chamber It has a configuration which is attached to the part.
[0008]
According to the first invention, since the first separation chamber and the second separation chamber are arranged in series, the oil that could not be separated in the first separation chamber can be reliably separated in the second separation chamber, and there is a risk that the oil may be ejected from the discharge port. There is no.
In addition, since the second oil pipe for returning the separated oil to the oil reservoir is attached to the front and rear end portions of the second separation chamber in the crankshaft direction of the internal combustion engine, the oil is introduced into the second separation chamber even when the internal combustion engine is inclined. Can be prevented and oil can be prevented from flowing into the atmosphere.
[0009]
According to a second aspect of the present invention, there is provided a breather structure attached to an internal combustion engine, the first separation chamber which is attached in communication with the crankcase and separates oil in blow-by gas discharged from a side surface of the crankcase; A first oil pipe that is attached to the chamber and returns the separated oil to an oil reservoir at the lower part of the crankcase; and a second oil pipe that is located above the first separation chamber and separates oil and gas in the blow-by gas. A separation chamber, a connecting pipe connecting the first separation chamber and the second separation chamber, a second separation chamber and an oil reservoir communicate with each other, and the oil separated in the second separation chamber is returned to the oil reservoir. and second oil pipe, attached to the second separation chamber, a separated gas possess an outlet for discharging the air, the second oil pipe for returning the separated oil to the oil reservoir, the internal combustion engine crank Axial front It has a configuration which is mounted on the front and rear end portions of the second separation chamber.
[0010]
According to the second invention, the first separation chamber is attached in communication with the crankcase, and the first separation chamber and the second separation chamber are arranged in series, so that the blowby gas can be efficiently guided to the first separation chamber, Furthermore, the oil that could not be separated in the first separation chamber can be reliably separated in the second separation chamber, and there is no fear that the oil will be ejected from the discharge port.
[0011]
A third invention is based on the first or second invention, wherein the breather structure for an internal combustion engine is constituted by a plurality of the first separation chambers and a single second separation chamber.
[0012]
According to the third invention, since the crankcase is provided with a plurality of first separation chambers, it is sufficiently capacityable for a large internal combustion engine, and in order to separate most of the oil in the first separation chamber, A single two separation chamber can provide a sufficient effect. Therefore, a breather structure for an internal combustion engine that can reduce the number of parts, is compact, and does not require a large space is obtained.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of a breather structure for an internal combustion engine according to the present invention will be described in detail with reference to the drawings.
[0016]
FIG. 1 is a front view showing an example of a breather device 10, and FIG. 2 is a view taken in the direction of arrow A in FIG. 1. Two first separation chambers 11, 11 are attached to the lower side surface of the crankcase 1. Each first separation chamber 11 communicates with the inside of the crankcase 1, and the lower portion of the first separation chamber 11 and the oil reservoir 2 attached to the lower portion of the crankcase 1 are the first oil that is an oil return means. Connected by a pipe 12. A predetermined baffle plate 13 is provided in the first separation chamber 11. A second separation chamber 20 is attached to the upper side surface of the crankcase 1 so as to be positioned above the first separation chambers 11 and 11. The upper parts of the first separation chambers 11 and 11 and the lower part of the second separation chamber 20 are connected and communicated by connecting pipes 14 and 14.
[0017]
The left and right lower portions of the second separation chamber 20, that is, the front and rear end portions in the axial direction of the crankshaft of the internal combustion engine, and the oil reservoir 2 are communicated by second oil pipes 21 and 21. Two discharge ports 22 are provided at the left and right lower portions of the second separation chamber 20. Discharge pipes 23 and 23 are attached to the discharge ports 22 and 22 and open below the oil reservoir 2. A predetermined baffle plate 24 is provided inside the second separation chamber 20. The two left and right connecting pipes 14 and 14 attached to the second separation chamber 20, the oil pipes 21 and 21, and the openings of the discharge ports 22 and 22 communicate with each other inside the second separation chamber 20.
[0018]
Next, the operation will be described. When the internal combustion engine is driven, blow-by gas containing oil enters the first separation chamber 11, most of the oil is separated by the baffle plate 13, and returned to the oil reservoir 2 through the first oil pipe 12. Thereafter, the blow-by gas enters the second separation chamber 20 through the connecting pipe 14, and the remaining oil and gas are completely separated by the baffle plate 24, and the oil is returned to the oil reservoir 2 through the second oil pipe 21. The separated gas is discharged from the discharge port 22 through the discharge pipe 23 to the atmosphere. In addition, since the second oil pipes 21 and 21 are provided at the front and rear end portions of the second separation chamber 20 in the axial direction of the crankshaft of the internal combustion engine, oil accumulates in the second separation chamber 20 even when the internal combustion engine is inclined. It is possible to prevent oil from flowing out into the atmosphere.
[0019]
Further, as shown in FIG. 3 showing the configuration of another embodiment of the breather device 10, the first separation chamber 11a communicates with the inside of the crankcase 1 by a pipe 11b, and an oil reservoir at the lower portion of the crankcase 1 is formed. The first oil pipe 12 for connecting with the second oil pipe 12 may not be provided. In this case, blow-by gas flows into the first separation chamber 11a from the pipe 11b, and the oil separated by the baffle plate 13a returns to the oil reservoir 2 from the pipe 11b which also serves as an oil return means.
[0020]
In the above description, as an example, a description has been given of a configuration in which the second separation chamber 20 that separates the oil and gas in the blow-by gas is provided above the first separation chamber 11. A third separation chamber for separating oil and gas in blow-by gas may be provided above 20, and further, a third separation chamber for separating oil and gas in blow-by gas may be disposed above the third separation chamber. A configuration in which a plurality of separation chambers are connected in series, such as by providing four separation chambers, may be employed.
[0021]
Since the breather structure for an internal combustion engine according to the present invention has the above-described configuration, even if the pressure of the blowby gas is high, the oil in the blowby gas is effectively separated and the oil is not discharged into the atmosphere. In addition, a breather structure for an internal combustion engine that is simple in structure, does not require a large space, and is inexpensive even in a large internal combustion engine can be obtained. Further, even if the internal combustion engine is inclined, it is possible to prevent oil from flowing out into the atmosphere.
[Brief description of the drawings]
FIG. 1 is a front view showing a configuration of a breather for an internal combustion engine according to the present invention.
FIG. 2 is a view taken in the direction of arrow A in FIG.
FIG. 3 is a front view showing the configuration of another embodiment of the breather for an internal combustion engine of the present invention.
FIG. 4 is a front view showing a configuration of a conventional breather for an internal combustion engine.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Crankcase, 2 ... Oil reservoir, 10 ... Breather apparatus, 11, 11a ... 1st separation chamber, 12 ... 1st oil pipe, 13, 13a, 24 ... Baffle plate, 14 ... Connection pipe, 20 ... 2nd separation Chamber, 21 ... second oil pipe, 22 ... discharge port, 23 ... discharge pipe.

Claims (3)

In the structure of a breather attached to an internal combustion engine,
A first separation chamber (11) for separating oil in blow-by gas discharged from the side surface of the crankcase (1);
Oil return means attached to the first separation chamber (11) and returning the separated oil to the oil reservoir (2) at the bottom of the crankcase (1);
A second separation chamber (20) located above the first separation chamber (11) and separating oil and gas in blow-by gas;
A connecting pipe (14) connecting the first separation chamber (11) and the second separation chamber (20);
A second oil pipe (21) communicating the second separation chamber (20) and the oil reservoir (2) and returning the oil separated in the second separation chamber (20) to the oil reservoir (2);
A discharge port (22) that is attached to the second separation chamber (20) and discharges the separated gas;
A second oil pipe (21) for returning the separated oil to the oil reservoir (2) is attached to the front and rear ends of the second separation chamber (20) in the crankshaft direction of the internal combustion engine. Breather structure for internal combustion engines. In the structure of a breather attached to an internal combustion engine,
A first separation chamber (11) attached in communication with the crankcase (1) and separating oil in blow-by gas discharged from a side surface of the crankcase (1);
A first oil pipe (12) which is attached to the first separation chamber (11) and returns the separated oil to an oil reservoir (2) below the crankcase (1);
A second separation chamber (20) located above the first separation chamber (11) and separating oil and gas in blow-by gas;
A connecting pipe (14) connecting the first separation chamber (11) and the second separation chamber (20);
A second oil pipe (21) communicating the second separation chamber (20) and the oil reservoir (2) and returning the oil separated in the second separation chamber (20) to the oil reservoir (2);
An outlet (22) attached to the second separation chamber (20) for discharging the separated gas into the air;
A second oil pipe (21) for returning the separated oil to the oil reservoir (2) is attached to the front and rear ends of the second separation chamber (20) in the crankshaft direction of the internal combustion engine. Breather structure for internal combustion engines. The breather structure for an internal combustion engine according to claim 1 or 2,
The internal combustion engine breather structure includes a plurality of first separation chambers (11) and a single second separation chamber (20).

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