JPS6229653Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention particularly relates to an air cleaner for an internal combustion engine equipped with a closed type blow-by gas reduction device.

The so-called blow-by gas that leaks into the crankcase from between the piston and the cylinder wall contains a large amount of hydrocarbons (HC), so it is possible to use the intake negative pressure to return this to the intake system and burn it within the cylinder. The apparatus for this purpose is known as a blow-by gas reduction apparatus.

This blow-by gas return device includes a breather chamber formed inside the cylinder head cover, communicates the chamber with the air cleaner and the intake manifold, sucks the blow-by gas with negative pressure in the intake manifold, and returns it to the intake system. A so-called closed type engine is often used in which fresh air is introduced into the crankcase from the air cleaner side via a breather chamber, thereby ventilating the inside of the crankcase.

By the way, when the internal combustion engine is under high load, a large amount of blowby gas leaks from the combustion chamber, and since the intake negative pressure in the intake manifold is small, there is little blowby gas returned to the intake manifold.
As a result, the pressure inside the crankcase and cylinder head cover increases and becomes higher than water pressure.
Blowby gas may flow backwards from the breather chamber side to the air cleaner side, and the blowby gas also contains oil mist. In such cases, if the oil mist is not separated and removed in the air cleaner, the oil mist will adhere to the carburetor and cause damage to the carburetor. This may cause malfunction.

On the other hand, since fresh air is introduced into the air cleaner, if this fresh air and blow-by gas are not separated and passed through the cleaner element, the oil mist in the blow-by gas will adhere to the entire cleaner element. The ability of the cleaner element to remove foreign matter decreases.

Also, as shown in Utility Model Application Publication No. 49-147429,
Some air cleaners have a separate cleaner element for removing oil mist from blow-by gas, but in this case, the number of parts in the air cleaner increases and the structure of the air cleaner becomes complicated.

The present invention was developed in view of the above circumstances, and its purpose is to divide the chamber consisting of the lower case and the cleaner element into two chambers, one of which is an air inlet chamber with an air inlet. In addition, by making the other chamber into a breather chamber with a blow-by gas inlet, and by communicating these two chambers with the intake system of the internal combustion engine through an integrated cleaner element, the blow-by gas generated by the engine and fresh air can be combined. To provide an air cleaner for an internal combustion engine, which separates and guides the air to a cleaner element, effectively separates and removes oil mist contained in the blowby gas, and then combines the blowby gas with fresh air and guides it to the intake system of the engine. There is something to do.

A preferred embodiment of the present invention will be described below in detail with reference to the accompanying drawings.

FIG. 1 is a longitudinal side view of the internal combustion engine, FIG. 2 is a longitudinal side view of the air cleaner, and FIG. 3 is a perspective view of the cleaner element.

In the engine 1 shown in FIG. 1, 2 is a cylinder block, and a piston 3 is fitted into the cylinder block 2 so as to be slidable up and down, and the piston 3 and the crankshaft 9 are connected by a connecting rod 4. has been done.

A cylinder head 5 is fixed to the upper surface of the cylinder block 2, and the upper surface of the cylinder head 5 is covered with a cylinder head cover 6.
Thus, a combustion chamber 7 is formed on the upper surface side of the piston 3, and the combustion chamber 7 communicates with a throttle body 11 via an intake port 8 and an intake manifold 10, and an air cleaner 1 is connected to the throttle body 11.
2 are in communication.

By the way, a breather chamber S is formed inside the cylinder head cover 6 and is divided by a breather plate 24, and the breather chamber S is further divided into a first chamber _S1 and a second chamber _S2 , and below this is formed a breather chamber S divided by a breather plate 24. Cam chamber formed Sc
The first chamber S ₁ is connected to PCV (Positive
Crankcase Ventilation) to the intake manifold 10 via the valve 26 and pipe 27 to the second chamber S ₂
are in communication with the air cleaner 12 via pipes 25, respectively. The PCV valve 26 is a type of flow control valve, and its flow characteristics are set such that the larger the differential pressure, the smaller the flow rate. Sho cam room
The Sc and the crankcase (not shown) communicate with each other.

As shown in FIG. 2, the air cleaner 12 is constructed by fastening a cleaner element 29 between an upper case 12a and a lower case 12b, which are integrally molded from resin, through a packing 28. The interior is divided into an upper chamber S ₃ and a lower chamber S ₄ by a cleaner element 29.
The lower chamber _S4 is further divided into an atmosphere introduction chamber _S4 ' and a breather chamber by a partition wall 12c protruding from the lower case 12b.
It is divided into S ₄ ″.

The upper chamber S ₃ communicates with the intake system of the engine 1 through the outlet 30, the atmosphere introduction chamber S ₄ ′ communicates with the atmosphere through the atmosphere introduction port 31, and the breather chamber S ₄ ″ communicates with the blow-by gas inlet 32. It communicates with the breather chamber S of the engine 1 through a pipe 25. A plurality of drain holes 33 are formed in the lower surface of the lower case 12b where the atmosphere introduction chamber S ₄ ' forms. The blow-by gas inlet 32 provided in the breather chamber S ₄ ″ is provided to be inclined downward.

On the other hand, the cleaner element 29 is integrally molded, and a main element 29a is provided in a portion facing the air introduction chamber S ₄ ′, and a sub-element 29b is provided independently in a portion facing the breather chamber S ₄ ″. There is.

Next, the operation of the air cleaner 12 described above will be described.

Since the first chamber S1 of the breather chamber S communicates with the intake manifold ₁₀ , it is maintained at negative pressure during engine operation, and the blow-by gas leaking into the crank chamber from between the piston 3 and the cylinder 2 is transferred to the first chamber. S ₁ and the blow-by gas passage, PCV valve 26 and pipe 27 within the chamber S ₁
The air is returned to the intake manifold 10 through the

On the other hand, fresh air is introduced into the second chamber _S2 through the air introduction port 31 into the air introduction chamber _S4 ' of the air cleaner 12, and the fresh air purified by the main element 29a is shown by the solid line arrow in FIG. The fresh air is introduced through a path as shown in FIG. 2, that is, through a path that passes through the sub-element 29b and flows into the breather chamber S ₄ ″, and this fresh air is further led into the crankcase to ventilate the inside of the crankcase.

However, when the internal combustion engine is under high load, a large amount of blowby gas leaks from the combustion chamber 7, and since the intake negative pressure in the intake manifold 10 is small, little blowby gas is returned to the intake manifold 10. Therefore, the pressure inside the crankcase and the cylinder head cover 6 becomes higher than atmospheric pressure, and blow-by gas flows from the second chamber _S2 side to the air cleaner 29 side. In such a case, the blow-by gas flows into the breather chamber S ₄ ″ from the blow-by gas inlet 32 of the air cleaner 12 as shown by the broken line arrow in FIG. After the air is separated and removed, the fresh air passes through the main element 29a from the air introduction chamber _S4 ' and joins with fresh air introduced into the upper chamber _S3 , and both are introduced into the intake system of the engine 1 from the outlet 30. .

In the above, the lower chamber S ₄ is divided into the atmosphere introduction chamber S ₄ ′ and the breather chamber S ₄ ″, and before the blow-by gas passes through the cleaner element 29, the blow-by gas is transferred to the atmosphere introduction chamber S ₄ ′. Since the introduced fresh air is not allowed to come into contact with the fresh air, oil mist, moisture, etc. contained in the blow-by gas may merge with the fresh air, or the air cleaner 12 may leak from the water drain hole 33 provided on the air introduction chamber _S4 ' side. There is no dripping outside.

In addition, since the blow-by gas inlet 32 provided in the breather chamber S ₄ ″ is provided with a downward slope, oil, water, etc. contained in the blow-by gas and separated by the element 29 flow through the inlet 32. It is returned to the Breather Chamber S side by its own weight.

As is clear from the above explanation, according to the present invention, the lower chamber composed of the lower case and the cleaner element is divided into two chambers, one chamber is used as the air introduction chamber and the breather chamber, and both of these chambers are divided into two chambers. Because it communicated with the engine's suction system through
The blowby gas and fresh air generated by the engine are separated and guided to a cleaner element to effectively separate and remove the oil mist contained in the blowby gas, and then the blowby gas and fresh air are combined and sent to the engine's intake system. can lead.

In addition, since a fresh air inlet and a blow-by gas inlet are provided in the lower chamber of the air cleaner, water, etc. that flow in with the fresh air can be easily discharged by falling downward, and oil, etc. that flow in with the blow-by gas, etc. The separation of the two is similarly facilitated.

3. Furthermore, since the air cleaner element is integral, the air cleaner has a simple structure and is easy to handle.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention; FIG. 1 is a longitudinal side view of an internal combustion engine, FIG. 2 is a longitudinal side view of an air cleaner, and FIG. 3 is a perspective view of a cleaner element. In the drawing, 10 is an intake manifold, 12 is an air cleaner, 12a is an upper case, 12b is a lower case, 29 is a cleaner element, 31 is an air inlet, 32 is a blow-by gas inlet, 33
is the water drain hole, S is the breather chamber, S ₁ and S ₂ are the first and second chambers, respectively, S ₃ and S ₄ are the upper and lower chambers, respectively, S ₄ ′ is the air introduction chamber, and S ₄ ″ is the breather chamber. be.

Claims (1)

[Scope of Claim for Utility Model Registration] (1) An upper chamber and a lower case that are composed of a resin upper case and a cleaner element, with a cleaner element fastened between the resin upper case and the lower case through a packing. In an air cleaner for an internal combustion engine, the lower chamber is divided into two chambers, one of which is an atmosphere introduction chamber having an atmosphere inlet, and the other chamber having a blow-by gas inlet. 1. An air cleaner for an internal combustion engine, characterized in that the air cleaner is a breather chamber, and these two chambers are connected to an intake system of the internal combustion engine via the cleaner element integrally formed and its upper chamber. (2) The air cleaner for an internal combustion engine according to claim 1, wherein the air introduction chamber and the breather chamber are defined in the lower chamber by a partition wall protruding from the lower case. (3) The air cleaner for an internal combustion engine according to claim 1, characterized in that a water drain hole is provided in a portion of the lower chamber that constitutes the lower surface of the air introduction chamber. (4) The air cleaner for an internal combustion engine according to claim 1, wherein the blow-by gas inlet provided in the breather chamber is inclined downward.