JPS6016725Y2 - Engine breather device - Google Patents

Description

[Detailed explanation of the invention] This invention is based on an engine that is tilted significantly during operation.
For example, it relates to a breather device for an engine mounted on a tiller, binder, combine harvester, etc.

Conventionally, the vicinity of the entrance to the breather device is as shown in FIG.

That is, a breather device 33 is attached to the opening surface of a tappet chamber liquid breather chamber 32 recessed in the crankcase 31, and the blow-by gas is passed from the crank chamber 34 to the oil cutting chamber 3.
5 into the crank chamber 34 and a communication hole 37 formed in the bottom wall of the tappet chamber fluid breather chamber 32 to reach the breather device 33.

However, with this one, if the engine tilts significantly,
The lubricating oil enters the oil cutting chamber 35, and not only the blow-by gas but also the lubricating oil is sent to the outside of the breather device 33 through the tappet chamber liquid breather chamber 32.

Therefore, the breather function was impaired, and the engine could not be tilted significantly during operation, resulting in poor tilting performance.

In order to eliminate the above-mentioned drawbacks, this device covers the opening of the oil cutter chamber to the crankcase so that the breather function will not be impaired even if the engine is tilted significantly. .

Examples of this invention will be described below based on the drawings.

FIG. 1 is a longitudinal sectional front view of a forced air-cooled single-cylinder vertical engine, and FIG. 2 is a sectional view taken along the line ■--■ in FIG.

In the figure, there is a crank chamber 3 surrounded by a cast crankcase 2 in the lower half of an engine 1, and the bottom of the crank chamber 3 is a lubricating oil chamber in which lubricating oil is stored.

A cylinder 4 is formed above the crankcase 2, and a piston 5 slides up and down within the cylinder 4.

On the right side of this cylinder 4 is a tappet chamber liquid breather chamber 6.
is opened outward and recessed in the crankcase 2, and a breather device 8 is fixedly attached to the opening surface 7 thereof.

The breather device 8 has a known structure including a breather plate having a breather hole, a reed valve for opening and closing the hole, and a plate for regulating the opening amount of the valve.

Immediately below the tappet chamber/breather chamber 6, that is, in the upper part of the crank chamber 3, an oil cutting chamber 9 is formed inside the expanded flesh wall of the crankcase 2.

This oil drain chamber 9 opens at a position further back from the front, that is, on the side of the casting mold extraction opening 10 of the crankcase 2, and its cross section is convexly curved outward and has a fan-like shape. are doing.

This opening surface 11 is closed with a sector-shaped blind cover 12 made of rubber or the like.

As shown in FIG. 3, vent holes 13 are provided in the upper and lower walls of the oil cutting chamber 9 to communicate the tappet chamber/breather chamber 6 and the oil cutting chamber 9, and the oil cutting chamber 9 and the crank chamber 3, respectively. The oil drain chamber 9 is drilled by a drill D inserted from the outside of the crankcase 2 through the opening surface 7 of the tappet chamber/breather chamber 6.

A thick wall portion 15 is formed in the inclined bottom wall 14 of the oil cutting chamber 9 along the depth direction when viewed from the opening surface 11.
The front surface 16 of 5 is located deeper than the opening surface 11, and its front space 17 communicates with the bottom of the oil drain chamber 9, so that the internal space of the oil drain chamber 9 swells by that portion.

This thick walled portion 15 has an oil return hole 19 extending from its front surface 16 to a peripheral surface portion 18 of the thick walled portion 15 facing the crank chamber 3.
is formed.

This hole 19 is drilled with a drill D that advances obliquely downward from the opening surface 11.

That is, the ventilation hole 13 and the oil return hole 19 are formed by the drill D after the crankcase 2 is cast.

In the figure, reference numeral 20 indicates an intake/exhaust valve, 21 a valve spring, and 22 a tappet.

Next, the effect will be explained.

When the engine 1 is in a horizontal state, blow-by gas leaking into the crank chamber 3 is pushed out through the vent hole 13 by the downward movement of the piston 5 into the tappet chamber/breather chamber 6, passes through the breather device 8, and enters the air cleaner 23. Enter the purification room.

For example, when this engine 1 is mounted on a traveling binder and goes over a ridge, the engine 1 is tilted greatly, and the lubricating oil level P is tilted greatly as shown in FIG. The oil level P reaches .

However, the opening surface 11 of the oil drain chamber 9 to the crank chamber 3
Since it is covered with a blind lid 12, lubricating oil does not enter the oil drain chamber 9.

Then, the blow-by gas enters the oil cutting chamber 9 through the vent hole 13 located above the oil level P, passes through the upper vent hole 13, and reaches the breather device 8.

Even if the engine 1 is tilted significantly in this way, the breather function is not impaired.

Furthermore, the mist-like lubricating oil contained in the blow-by gas adheres to the walls of the oil drain chamber 9 and the tappet chamber/breather chamber 6, flows down, and is returned into the crank chamber 3 through the oil return hole 19.

This will become more effective if a blocking plate 24 is provided in the oil drain chamber 9 to block linear communication between the upper and lower ventilation holes 13, as shown by imaginary lines in FIG.

Since this invention is constructed as described above, it has the following effects.

In other words, since the opening of the oil drain chamber to the crank chamber is covered, lubricating oil will not enter the oil drain chamber even if the engine is tilted significantly, so the breather function will not be impaired as in the conventional case. You won't get lost.

Therefore, the tilting performance of the engine can be improved.

Furthermore, since the oil return hole from the oil cut chamber to the crank chamber is formed by drilling a hole in the bottom wall of the oil cut chamber, it can be formed easily and inexpensively with a drill or the like after the crankcase is cast.

[Brief explanation of the drawing]

The drawings show an embodiment of this invention, and FIG. 1 is a longitudinal sectional front view of the engine, FIG. 2 is a sectional view taken along the line ■-■ in FIG. 1, FIG. The figure is a diagram corresponding to FIG. 1 showing a conventional example. 2...Crankcase, 3...Crank chamber, 4...Cylinder, 6...Tappet room/breather room, 9...Oil Cutting room, 10...
...opening surface for casting mold extraction of 2, 11...
Opening surface of 9, 12...Blind lid, 14...
Bottom wall of 9, 15... Thick wall part, 16...
15 front, 17...front space, 18...
...Surrounding part, 19...Oil return hole.

Claims (1)

[Scope of utility model registration request] A tappet chamber fluid breather chamber 6 is formed next to the cylinder 4 on the upper side of the crankcase 2 so that one side thereof opens outward, and is located in the upper part of the crankcase 2 immediately below the tappet chamber fluid breather chamber 6. An oil cut chamber 9 is formed on the same surface as the opening surface 10 for removing the casting mold of the crankcase 2.
The opening surface 11 of the oil cut chamber 9 is closed with a blind cover 12, and the tappet chamber 6 and the oil cut chamber 9 are installed on the upper and lower walls of the oil cut chamber 9.
A vent hole 13 is formed in the lower wall of the oil cut chamber 9 to communicate the oil cut chamber and the crank chamber 3, respectively.
3 is formed at a position that opens above the oil level P when the engine is tilted, and a thick wall portion 15 is formed along the depth direction when viewed from the opening surface 11 on the bottom wall 14 of the oil cut chamber 9. The front space 17 of the thick wall portion 15 is communicated with the bottom of the oil drain chamber 9, and an oil return hole 19 is bored from the front surface 16 of the thick wall portion 15 to the peripheral surface portion 18 facing the crank chamber 3 toward the opening surface 11. An engine breather device characterized by: