JPS61205311A - Breather device of internal combustion engine - Google Patents

Abstract

PURPOSE:To primarily separate oil mist mixed in blow-by gas which flows through a throttle passage, so as to enhance the effect of separation by forming both the throttle passage in the way of a breather passage placed at the side of a cylinder block and an expansion chamber at the upper side of the throttle passage. CONSTITUTION:A breather passage 17, slanting to one side with respect to the longitudinal direction, is formed at the intake side of an engine body E. The passage 17 consists of a passage 17b formed in a cylinder block B and a passage 17h formed in a cylinder head H. The open lower end of the passage 17b is communicated with a crankcase 15 while the open upper end of the passage 17h is communicated with a tappet cam chamber 13. The passage 17b has both a throttle passage 18 formed in the way thereof and an expansion chamber 19 formed at the upper side of the passage 17b. The expansion chamber 19 opens on the deck face of the cylinder block B and is communicated with the passage 17h. When blow-by gas flows through the passage 17b, oil mist mixed in said gas is separated primarily.

Description

DETAILED DESCRIPTION OF THE INVENTION A0 OBJECTS OF THE INVENTION (1) Industrial Field of Application The present invention relates to a breather device that communicates the crank chamber and valve operating cam chamber of an internal combustion engine.

B) Conventional technology In conventional internal combustion engines, a breather passage is formed in the engine body to communicate the crank chamber and the valve train cam chamber, and an intake action is performed between these chambers to remove the blow-by gas generated in the crank chamber. It is known that the air is returned to the intake system through a passage and via a valve train cam chamber.

By the way, it is unavoidable that oil mist is mixed into the blow-by gas generated in the crank chamber, so it is desirable to separate the oil mist from the blow-by gas as much as possible while the blow-by gas passes through the breather passage. The breather passage was not provided with any means for separating such oil mist.

(3) Problems to be Solved by the Invention Therefore, the present invention improves the breather passage that communicates between the crank chamber and the valve train cam chamber, thereby eliminating oil mixed therein while the blow-by gas passes through the breather passage. It is an object of the present invention to provide a breather device for an internal combustion engine, which has a simple structure and can actively separate mist.

B8 Structure of the Invention (Means for Solving Problems 11) According to the present invention, in order to achieve the above object, a breather passage is formed in the engine body, and through this breather passage the valve operating cam chamber in the upper part of the engine body and its lower part are connected. In the breather device for an internal combustion engine, which communicates with a crank chamber, a throttle passage and an expansion chamber above the throttle passage are formed in the middle of a block-side breather passage formed in the cylinder block of the breather passage.

(2) Function The oil mist mixed in the blow-by gas flowing through the breather passage is temporarily separated while passing through the throttle passage and expansion chamber formed in the passage.

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

The engine body E of the in-line four-cylinder water-cooled internal combustion engine consists of a cylinder block B and a cylinder head H which is superimposed and fixed on the upper surface of the cylinder block B via a gasket G.

The cylinder block B is made of aluminum alloy and consists of an upper cylinder part 1 and a lower crankcase part 2. A plurality of cylinder bores 3 are arranged in series in the cylinder 1 . Adjacent boundary walls 5 between adjacent cylinder bores 3 have no water jacket, and are of a so-called Siamese type. A cylinder liner 4 is cast into each cylinder bore 3, and a piston 6 is slidably fitted into the liner 4.

A plurality of journal walls 7 are integrally formed in the crankcase portion 2 defining the crank chamber 15 of the cylinder block B along the arrangement direction of the cylinder bores 3, and a bearing cap 8 is provided at the bottom of each journal wall 7. is fixed, and a crankshaft lO is rotatably supported in the bearing hole 9 formed between the journal wall 7 and the bearing cap 8.
As usual, the crankshaft 10 is connected to the piston 6 via a connecting rod 11.

A water jacket 12 is formed in the cylinder portion 1 of the cylinder block B so as to surround the cylinder bore 3.
It is formed to be long over almost the entire length.

A valve operating cam chamber 13 is formed on the cylinder head H, and a valve operating mechanism 14 is provided in this valve operating cam chamber 13.

An oil pan 16 is fixed to the lower surface of the crankcase portion 2, and lubricating oil is stored within the oil pan 16.

On the intake side of the engine body E, a breather passage 17 is formed biased to one side in the longitudinal direction.This breather passage 17 is formed in a block side breather passage 17b formed in the cylinder block B and in the cylinder head H. The opening lower end of the block side breather passage 17b is communicated with the crank chamber 15, and the opening upper end of the head side breather passage 17h is communicated with the valve operating cam chamber 13.

In the block side breather passage 17b, a throttle passage 18 with a small cross section is formed in the middle thereof, and an expansion chamber 19 with a large volume is formed above the restriction passage 18. It opens in the deck surface of the cylinder block B and communicates with the head side breather passage 17h.

Further, on the intake side side surface of the engine body E, an air guide passage 20 is formed so as to straddle the cylinder block B and the cylinder head H, biased toward the other side in the longitudinal direction.
Its upper end communicates with the valve operating cam chamber 13, and its lower end communicates with the crank chamber 15. A horizontal expansion chamber 21 is formed in the air guide path 20 near the crank chamber 15, and this expansion chamber 21 has an opening 2 in the side wall of the cylinder block B.
An inlet 24 of a conventionally known oil separator 23 is connected to this opening 22, and an outlet 25 of this separator 23 is communicated with an intake manifold 27 of the engine via a conventionally known PCv valve 26.

In the figure, 28 is an air cleaner, 29 is an intake valve 30, an exhaust valve, and 31 is a valve drive camshaft 32, 33, and 34 are oil gears.

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

When the engine is now operated, blow-by gas is generated within the crank chamber 15.

A part of the blow-by gas in the crank chamber 15 flows into the valve cam chamber 13 through the block side breather passage 17b and the head side breather passage 17h, and further flows from the valve cam chamber 13 into the air guide passage 20. When the blow-by gas flows through the block-side breather passage 17b and flows into the oil separator 23, it passes through the throttle passage 18 and the expansion chamber 19, so that the oil mist mixed in the blow-by gas becomes droplet-like. The oil is temporarily separated from the blow-by gas and dripped into the oil reservoir in the oil pan 16. In the oil separator 23, the oil mist in the blow-by gas is finally separated.
Blow-by gas after oil mist separation is PC valve 2
6 and is sucked into the intake pipe 27.

The other part of the blow-by gas in the Naori rank chamber 15 is
The oil mist is separated in the expansion chamber 21 along the air guide road 20 and sucked into the oil separator 23 .

Effects of C0 Invention As is clear from the above examples, according to the present invention,
A block side breather passage is formed in the cylinder block,
Since a throttle passage and an expansion chamber above the throttle passage are formed in the middle of this breather passage, the blow-by gas flowing through the block-side breather passage passes through the throttle passage and expansion chamber, and the oil mist mixed therein is removed. The oil mist mixed in the blowby gas can be effectively separated from the blowby gas in the form of droplets, and as a result, the oil mist mixed in the blowby gas can be effectively separated within the engine body, and the oil mist separation means outside the engine body can have a small capacity. This makes it possible to

[Brief explanation of the drawing]

The drawings show one embodiment of the device of the present invention, and FIG. 1 is a longitudinal cross-sectional view of the engine main body along the line I-1 in FIG. 3, and FIG.
FIG. 3 is a plan view of the cylinder block of the engine main body, and FIG. 4 is a side view of the cylinder block taken along the line ■ in FIG. 3. E...Engine body, B...Cylinder block E3...
・Valve train cam chamber, 15... Crank chamber, 17b... Block side breather passage, 18... Throttle passage, 19...
・Bulgar chamber

Claims (1)

[Claims] In a breather device for an internal combustion engine, which forms an engine body breather passage and communicates a valve train cam chamber in the upper part of the engine body with a crank chamber in the lower part thereof through the breather passage, the breather device is formed in a cylinder block of the breather passage. A breather device for an internal combustion engine, characterized in that a throttle passage and an expansion chamber above the throttle passage are formed in the middle of a block side breather passage.