JP3057408B2 - Engine breather device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a breather device for an engine, and more particularly, to a device for reducing the overall height of an engine and reducing the amount of oil taken out of the breather chamber by blow-by gas.

[0002]

2. Description of the Related Art FIG. 3 shows a prior art of a breather device for an engine. This has the following basic structure as in the present invention. That is, rocker arm 1
01 on the head cover 102 containing the breather chamber 103.
The breather chamber 103 has a blow-by gas inlet 1
04 and the blow-by gas outlet 105 are opened.

In a breather device having such a basic structure, blow-by gas containing oil mist flows from a crankcase (not shown) to a head cover 10 as shown by an arrow.
2, the blow-by gas flows into the breather chamber 103 from the blow-by gas inlet 104, and the oil mist contained in the blow-by gas is separated from the blow-by gas while passing through the breather chamber 103. And
The separated oil is returned into the head cover 102 from the blow-by gas inlet 104 also serving as an oil return hole, and the blow-by gas separated from the oil is supplied to the blow-by gas outlet 10.
5 is discharged out of the head cover 102.

In this prior art, the breather chamber 103 is provided so as to bulge outward from the ceiling wall 111 of the head cover 102, and a filter 112 made of steel wool is accommodated in the breather chamber 103, and is provided below the breather chamber 103. The provided blow-by gas inlet 104 faces the rocker arm 101.

[0005]

The above prior arts have the following problems. Breather room 103 is ceiling wall 11 of head cover 102
1, the overall height of the engine is increased by an amount corresponding to the bulging of the breather chamber 103, which is contrary to the demand for downsizing the engine.

[0006] Since the blow-by gas inlet 104 of the breather chamber 103 faces the rocker arm 101, oil splatters enter the breather chamber 103 from the blow-by gas inlet 104 due to rocking of the rocker arm 101, and the filter 112 is impregnated with a large amount of oil. , The blow-by gas passing through the filter 112 causes the blow-by gas outlet 1
A lot of oil is taken out from 05. For this reason, in the closed type breather device in which the blow-by gas outlet 105 communicates with the intake passage, a large amount of oil flows into the intake passage, and the engine may overrun. Also,
In the open type breather device in which the blow-by gas outlet 105 is opened to the atmosphere, a lot of oil is discharged into the atmosphere,
The surrounding environment may be contaminated.

[0007] The filter 112 made of steel wool is
Because of the structure in which steel wool fibers are entangled in a three-dimensional network, the impregnated oil does not easily flow down. For this reason, the structure of the filter 112 also causes an increase in the amount of oil taken out.

An object of the present invention is to provide a breather device for an engine that can reduce the overall height of the engine and reduce the amount of oil taken out of the breather chamber by blow-by gas.

[0009]

According to the present invention, as shown in FIG. 1A, a breather chamber 3 is provided in a head cover 2 accommodating a rocker arm 1, and a blow-by gas inlet 4 and a blow-by gas are provided in the breather chamber 3. A breather device for an engine, which is configured so as to be open to the outlet 5, is characterized as follows.

That is, as exemplified in FIG.
A breather chamber 3 is disposed at an end of the head cover 2 in the direction of the rocking arm axis 7 of the rocker arm 1, and as viewed in a direction parallel to the rocking center axis 7, as illustrated in FIG. A plurality of blow-by gas guide plates 9 that are inclined with respect to the inner wall are provided in the breather chamber 3, a blow-by gas inlet 4 is opened in the lower wall 8 of the breather chamber, and the blow-by gas flowing from the blow-by gas inlet 4 into the breather chamber 3 is blow-by. An oil mist contained in the blow-by gas is condensed on the surface of the blow-by gas guide plate 9 by being guided in a meandering manner by the gas guide plate 9, and an oil return hole 10 is opened in the lower wall 8 of the breather chamber. The condensed oil dropped on the breather chamber lower wall 8 from the lower end of the guide plate 9 is caused to flow out of the oil return hole 10 into the head cover 2.

[0011]

When blow-by gas containing oil mist flows into the head cover 2 from a crankcase (not shown) as shown by an arrow in FIG. 1, the blow-by gas flows into the breather chamber 3 from the blow-by gas inlet 4 and blow-by gas. The gas mist is guided in a meandering manner by the gas guide plate 9, and the oil mist contained in the blow-by gas condenses on the surface of the blow-by gas guide plate 9 and is separated from the blow-by gas. Condensed oil is
It travels along the surface of the blow-by gas guide plate 9 inclined by its own weight, drops from the lower end onto the lower wall 8 of the breather chamber, and passes through the oil return hole 10 from the breather chamber 3 to the head cover 2.
Spills into. The blow-by gas from which the oil has been separated is discharged from the blow-by gas outlet 5 to the outside of the head cover 2.

[0012]

The present invention has the following effects (see FIG. 1). Since the breather chamber 3 is formed at the end of the head cover 2, the breather chamber 3 can be arranged without protruding from the ceiling wall 11 of the head cover 2 while avoiding interference with the rocker arm 1. Can be lowered.

Since the breather chamber 3 is formed at the end of the head cover 2 and the blow-by gas inlet 4 is opened in the lower wall 8 of the breather chamber, the blow-by gas inlet 4 is connected to the rocker arm 1.
The oil droplets generated by the rocker arm 1 swinging can be prevented from entering the breather chamber 3 from the blow-by gas inlet 4. Therefore, the amount of oil entering the breather chamber 3 is reduced, and the amount of oil taken out from the blow-by gas outlet 5 by the blow-by gas can be reduced. Thereby, the blow-by gas outlet 5
In the closed type breather device in which the oil is communicated with the intake passage, a large amount of oil does not flow into the intake passage, and the overrun of the engine can be suppressed. Also, blow-by gas outlet 5
In the open-type breather device in which the air is released to the atmosphere, a large amount of oil is not discharged into the atmosphere, and the pollution of the surrounding environment can be suppressed.

The oil condensed on the surface of the blow-by gas guide plate 9 travels along the surface of the blow-by gas guide plate 9 inclined by its own weight, drops from the lower end thereof, and is quickly discharged from the breather chamber 3. Therefore, the amount of oil stagnating in the breather chamber 3 is reduced, and the amount of oil taken out of the blow-by gas outlet 5 by the blow-by gas can be reliably reduced.

[0015]

An embodiment of the present invention will be described with reference to the drawings.
In this embodiment, a two-cylinder overhead valve type vertical diesel engine is used. The structure of this engine is as follows.

That is, as shown in FIG. 2, a cylinder head 14 and a head cover 2 are sequentially assembled above a cylinder block 13. Cylinder block 13
A gear case 15 is assembled on the front side of the vehicle, a cooling fan 16 is arranged on the front side, and a generator 17 is arranged on the side. A pump case 19 accommodating a fuel injection pump 18 is disposed on one side of the cylinder block 13, and a starter motor 20 is disposed on the other side. A flywheel 21 is disposed on the rear side of the cylinder block 13, and a ring gear 22 fitted and fixed to the flywheel 21 is engaged with a pinion gear of the starter motor 20. An exhaust manifold 23 is disposed on one side of each side of the cylinder head 14, and an intake manifold 24 is disposed on the other side.

As shown in FIG. 1A, two local arm brackets 25 are fixed on the cylinder head 14 of the engine, and a local arm pivot 26 is horizontally supported on the local arm bracket 25. A pair of local arms 1 are pivotably supported. These components arranged on the cylinder head 14 are housed in the head cover 2. The local arm bracket 25 and the head cover 2
Both are fixed to the cylinder head 14 with nuts screwed to the stud bolts 6.

A vertical blow-by gas floating passage 27 is provided in the cylinder head 14 so that a crank chamber (not shown) and the inside of the head cover 2 are communicated with each other. From the head cover 2.

A breather chamber 3 is provided in the head cover 2, and a blow-by gas inlet 4 and a blow-by gas outlet 5 are opened in the breather chamber 3. As a result, when blow-by gas containing oil mist flows into the head cover 2 from the crankcase (not shown) as shown by the arrow, the blow-by gas flows into the breather chamber 3 from the blow-by gas inlet 4 and is contained in the blow-by gas. The oil mist is separated from the blow-by gas while passing through the breather chamber 3.

In this embodiment, the following structure is employed to reduce the total height of the engine and the amount of oil taken out of the breather chamber 3 by blow-by gas.

That is, the breather chamber 3 is provided at the end of the head cover 2 in the direction of the swing center axis 7 of the rocker arm 1.
Is arranged. As shown in FIG. 1B, a plurality of blow-by gas guide plates 9 that are inclined with respect to the vertical direction when viewed in a direction parallel to the swing center axis 7 are provided in the breather chamber 3, and A blow-by gas inlet 4 is opened in the lower wall 8 of the room. Thereby, the blow-by gas flowing into the breather chamber 3 from the blow-by gas inlet 4 is guided in a meandering manner by the blow-by gas guide plate 9, and the oil mist contained in the blow-by gas is condensed on the surface of the blow-by gas guide plate 9.

The blow-by gas inlet 4 of the lower wall 8 of the breather chamber also serves as an oil return hole 10, and condensed oil dropped on the lower wall 8 of the breather chamber from the lower end of the blow-by gas guide plate 9 is used to return the oil return hole. The gas flows out from the blow-by gas inlet 4 also serving as 10 into the head cover 2. The oil return hole 10 may be provided separately from the blow-by gas inlet 4.

According to such a configuration, the rocker arm 1
The breather chamber 3 can be arranged without protruding from the ceiling wall 11 of the head cover 2 in a state where interference with the engine is avoided, and the overall height of the engine can be reduced. Also, blow-by gas inlet 4
Can be arranged without facing the rocker arm 1, oil splashes generated by rocking of the rocker arm 1 can be prevented from entering the breather chamber 3 from the blow-by gas inlet 4, and oil condensed on the surface of the blow-by gas guide plate 9 Since the oil is quickly discharged from the breather chamber 3, the amount of oil stagnating in the breather chamber 3 is reduced, and the amount of oil taken out of the blow-by gas outlet 5 by the blow-by gas can be reliably reduced.

In this embodiment, as shown in FIG. 1 (A), a partition plate 28 is vertically provided from the breather chamber lower wall 8, and the partition plate 28 forms an inlet space 29 below the blow-by gas inlet 4 by a local arm housing space. It is divided from 30.
As a result, lubricating oil droplets scattered in the local arm housing space 30 are more unlikely to enter the blow-by gas inlet 4.

In this embodiment, the blow-by gas floating passage 27 also serves as an oil return passage from inside the head cover 2 to the crank chamber. That is, the oil supply port 31 is provided in the ceiling wall 11 of the head cover 2 and the local arm 1
Lubricating oil is supplied from a forced lubrication device (not shown) to the sliding gap between the lubricating oil and the lubricating oil supplied from the oil replenishing port 31 and the lubricating oil leaked from the loker arm 1. The oil is returned from the blow-by gas floating passage 27 to an oil pan (not shown) located below the crank chamber.

In this embodiment, as shown by the solid line in FIG. 1A, the blow-by gas floating passage 27 is opened so as to face the blow-by gas inlet 4. However, as shown by the chain line in FIG. Alternatively, the blow-by gas floating passage 27 may be opened facing the rocker arm housing space 30. In this case, even if the lubricating oil flowing down in the blow-by gas floating passage 27 is blown up by the blow-by gas, the splash does not enter the breather chamber 3 from the blow-by gas inlet 4.

In this embodiment, the breather chamber 3 is formed by covering a space recessed at the end face of the head cover 2 with a cover plate 34. The cover plate 34 is detachable by screwing, and maintenance of the breather chamber 3 can be easily performed by removing the cover plate 34. The blow-by gas guide plate 9 is formed integrally with the head cover 2.

In this embodiment, as shown in FIG. 2, the breather device draws a pipe 32 from the blow-by gas outlet 5 of the breather chamber 3 and connects the leading end of the pipe 32 to a master pipe 33 of the intake manifold 24. It is a closed type. Since the main pipe 33 of the intake manifold 24 is located closer to the flywheel 21 than the fuel injection pump 18, the breather chamber 3 is also located at the end of the head cover 2 on the flywheel 21 side. Thereby, the pipe 3
2 can be arranged without interfering with the fuel injection pump 18.

Although the contents of the embodiment of the present invention are as described above, the present invention is not limited to the above embodiment. For example, the present invention can be applied not only to a two-cylinder overhead valve type vertical diesel engine but also to various types of engines of a single cylinder, multiple cylinders, side valves, overhead cams, and horizontal types.

[Brief description of the drawings]

FIG. 1 is a view for explaining a main part of an engine according to an embodiment of the present invention. FIG. 1 (A) is a longitudinal sectional view of a portion around a head cover, and FIG. 1 (B) is BB in FIG. 1 (A). It is a line sectional view.

FIG. 2 is a plan view of the engine according to the embodiment of the present invention.

FIG. 3 is a diagram corresponding to FIG.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Rocker arm, 2 ... Head cover, 3 ... Breather chamber, 4 ... Blow-by gas inlet, 5 ... Blow-by gas outlet, 7 ... Rocking arm 1 swing center axis line, 8 ... Breather chamber lower wall, 9 ... Blow-by gas guide plate, 10 … Oil return hole.

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Nobuhiro Yamamoto 64 Ishizukitamachi, Sakai-shi, Osaka, Japan Kubota Sakai Works, Inc. (72) Inventor Akira Hayaya 64 Ishizukitamachi, Sakai-shi, Osaka Prefecture, 64 Kubota Sakai Works, Inc. (56 References: Japanese Utility Model Application Hei 3-89918 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) F01M 13/04

Claims (1)

(57) [Claims] A head cover (2) for accommodating a rocker arm (1) is provided with a breather chamber (3), and the breather chamber (3) is provided with a blow-by gas inlet (4) and a blow-by gas outlet (5). In the breather device for an engine, a breather chamber (3) is disposed at an end of the head cover (2) in the direction of the rocking arm axis (7) of the rocker arm (1), and is parallel to the rocking center axis (7). A plurality of blow-by gas guide plates (9) that are inclined with respect to the vertical direction when viewed in the
A blow-by gas inlet (4) is provided in the lower wall (8) of the breather chamber, and the blow-by gas flowing into the breather chamber (3) from the blow-by gas inlet (4) is supplied to the blow-by gas guide plate (3). 9), the oil mist contained in the blow-by gas is condensed on the surface of the blow-by gas guide plate (9), and an oil return hole (10) is formed in the lower wall (8) of the breather chamber. The condensed oil dropped from the lower end of the blow-by gas guide plate (9) onto the lower wall (8) of the breather chamber is caused to flow out of the oil return hole (10) into the head cover (2). Engine breather device.