JPH0627774Y2 - Blow-by gas extraction device for internal combustion engine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to blow-by gas in a cylinder head cover that covers the upper surface of a cylinder head, an intake system downstream of a carburetor, and an intake system upstream of a carburetor. And a blow-by gas extraction device adapted to perform extraction on both of them.

[Conventional technology]

In Japanese Utility Model Laid-Open No. 56-81148 as a prior art, a gas-liquid separation chamber communicating with the inside of the cylinder head cover is formed on the inner surface of a cylinder head cover that covers the upper surface of the cylinder head. While connecting to the intake system on the upstream side of the carburetor via the blow-by gas passage, a filler cap for the oil filler of the cylinder head cover is formed with a gas-liquid separation chamber communicating with the inside of the cylinder head cover. A blow-by gas extraction device is proposed in which the separation chamber is connected to an intake system downstream of the vaporizer via a first blow-by gas passage.

Further, in this conventional blow-by gas extraction device, in a low load region where the amount of blow-by gas generated is small, the intake negative pressure on the downstream side of the carburetor becomes large, so that the blow-by gas in the cylinder head cover is removed from the first blow-by gas. While being extracted into the intake system via the passage, in a high load region where the amount of blow-by gas generated is large, the negative pressure in the entire intake system increases, so that blow-by gas in the cylinder head cover is removed from the first blow-by gas passage and the first blow-by gas passage. It is extracted into the intake system through both of the two blow-by gas passages.

[Problems to be solved by the invention]

However, this conventional blow-by gas extraction device has the advantage that the oil filler cap can also be used as the gas-liquid separation section for the first blow-by gas passage, while the second blow-by gas passage to the intake system upstream of the carburetor is ,
The blow-by gas, which is connected to a gas-liquid separation chamber formed in the cylinder head cover so as to communicate with the inside of the cylinder head, is extracted into the intake system on the upstream side of the carburetor through the second blow-by gas passage. The gas-liquid separation chamber in the cylinder head cover only receives the gas-liquid separation action once.

If the gas-liquid separation action of the gas-liquid separation chamber formed in the cylinder head cover is incomplete, the amount of lubricating oil that accompanies the blow-by gas to the upstream side of the vaporizer increases. However, various problems such as clogging of various jets in the carburetor and burning of the throttle valve will frequently occur. To solve this, the gas-liquid separation action in the gas-liquid separation chamber formed on the inner surface of the cylinder head cover should be improved.
Since the gas-liquid separation chamber must be configured to have a considerably large volume, the structure is complicated, the internal combustion engine is upsized, and the weight is increased.

The present invention ensures that the lubricating oil entrained in the blow-by gas to the intake system upstream of the carburetor is prevented without causing this problem, that is, the structure being complicated, the internal combustion engine being large in size, and the weight being increased. Provided is a blow-by gas extraction device capable of reducing the amount.

[Means for Solving the Problems] In order to achieve this object, the present invention provides a gas-liquid separation chamber communicating with the inside of an oil filler cap for an oil filler provided on a cylinder head cover that covers the upper surface of the cylinder head. In the internal combustion engine in which the first blow-by gas passage to the intake system on the downstream side of the carburetor is connected to the gas-liquid separation chamber, the inner surface of the cylinder head cover is not in communication with the inside of the cylinder head cover. A gas-liquid separation chamber is formed, and a second blow-by gas passage to the intake system upstream of the vaporizer is connected to the gas-liquid separation chamber in the cylinder head cover.
Moreover, the gas-liquid separation chamber of the oil filler cap and the non-communicating gas-liquid separation chamber in the cylinder head cover are connected via a blow-by gas passage, and the gas-liquid separation of the oil filler cap in the first blow-by gas passage is performed. The opening into the separation chamber and the opening into the gas-liquid separation chamber of the oil filler cap in the blow-by gas passage are opposed to each other, while the baffle plate is located inside the gas-liquid separation chamber of the oil filler cap and the blow-by gas. The structure is provided below the opening of the oil filler cap in the passage into the gas-liquid separation chamber and in the first blow-by gas passage below the opening of the oil filler cap in the gas-liquid separation chamber.

[Function and effect of device]

In this configuration, the blow-by gas in the cylinder head cover is subjected to the gas-liquid separation action in the gas-liquid separation chamber of the oil filler cap in the low load region of the internal combustion engine, and then the vaporizer is passed through the first blow-by gas passage. It is extracted into the intake system on the more downstream side.

On the other hand, in the high load region of the internal combustion engine, after being subjected to the gas-liquid separation action in the gas-liquid separation chamber in the oil filler cap,
At the same time as being extracted into the intake system on the downstream side of the carburetor through the first blow-by gas passage, the blow-by gas passage is passed through the gas-liquid separation chamber in the cylinder head cover,
It is extracted into the intake system upstream of the carburetor via the second blow-by gas passage.

By the way, the blow-by gas extracted into the intake system upstream of the carburetor through the second blow-by gas passage is
First, the gas-liquid separation chamber in the oil filler cap is subjected to a gas-liquid separation action, and then, when the gas flows out from the blow-by gas passage from the gas-liquid separation chamber in the oil filler cap, the oil mist that accompanies it. Is subjected to a separating action that is removed by the suction action from the first blow-by gas passage to the downstream side of the carburetor, and is further subjected to a gas-liquid separating action in the gas-liquid separating chamber in the cylinder head cover.

In this case, the opening of the oil filler cap in the first blow-by gas passage into the gas-liquid separation chamber and the opening of the oil filler cap in the blow-by gas passage into the gas-liquid separation chamber face each other,
A baffle is provided in the gas-liquid separation chamber of the oil filler cap, an opening of the oil filler cap in the blow-by gas passage into the gas-liquid separation chamber, and a baffle plate in the gas-liquid separation chamber of the first blow-by gas passage into the gas-liquid separation chamber. By providing the portion below the opening, it is possible to prevent the blow-by gas from flowing out from the gas-liquid separation chamber of the oil filler cap through the blow-by gas passage.
Since a strong suction action can be exerted from the blow-by gas passage to the downstream side of the carburetor, the oil mist entrained in the blow-by gas flowing out of the blow-by gas passage from the gas-liquid separation chamber in the oil filler cap is transferred to the first blow-by gas passage. Can be separated so as to effectively suck it downstream of the vaporizer.

That is, as described above, the blow-by gas extracted from the second blow-by gas is the gas-liquid separation chamber in the oil filler cap, the suction portion into the first blow-by gas passage, and the gas-liquid separation chamber in the cylinder head cover. Since the location is subjected to the gas-liquid separation action, the lubricating oil entrained in the extraction blow-by gas to the intake system on the upstream side of the vaporizer can be significantly reduced.

Therefore, according to the present invention, the blow-by gas can be removed without increasing the size of the gas-liquid separation chamber provided in the cylinder head cover, and consequently the internal combustion engine, and increasing the weight.
There is an effect that it is possible to reliably reduce clogging of various jets in the carburetor and seizure of the throttle valve due to the adverse effect of extraction in the intake system upstream of the carburetor and the lubricating oil in the blow-by gas.

〔Example〕

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In the drawings, reference numeral 1 denotes a cylinder head cover detachably attached to an upper surface of a cylinder head 2 in an internal combustion engine so as to cover a valve mechanism (not shown). Show.

On the ceiling plate 1a of the cylinder head cover 1, an open-bottom type box 3 is integrally formed, and on the lower surface of the box 3, a bottom plate 4 for closing the open part is attached, and the inside thereof is It is formed in a gas-liquid separation chamber 5 that is not in communication with the inside of the head cover 1, and in this gas-liquid separation chamber 5, a second air cleaner 8 in the intake system of the internal combustion engine is introduced into the air cleaner 8 upstream of the carburetor 7 with the throttle valve 6. The blow-by gas passage 9 is connected.

In addition, the oil filler cap 11 made of oil-proof rubber which is detachable from the oil filler 10 provided on the cylinder head cover 1 is made hollow, and a plurality of baffle plates 12 are provided inside the oil filler cap 11. Is formed in the gas-liquid separation chamber 13 communicating with the.

Then, in the gas-liquid separation chamber 13 of the oil filler cap 11, at a portion above the baffle plate 12 in the gas-liquid separation chamber 13, to the intake manifold 14 downstream of the carburetor 7 in the intake system of the internal combustion engine. First of
The blow-by gas passage 15 is connected, and the blow-by gas passage 16 to the gas-liquid separation chamber 5 in the cylinder head cover 1 is connected to the gas-liquid separation chamber 13 of the oil filler cap 11 in the first blow-by gas passage 15. And the opening of the oil filler cap 11 in the blow-by gas passage 16 into the gas-liquid separation chamber 13 are provided at positions facing each other.

It should be noted that the oil filler 10 is provided at a place where the lubricating oil is less scattered by the valve operating mechanism, such as one end portion in the longitudinal direction of the internal combustion engine, and the bottom plate 4 is extended to a lower portion of the oil filler 10. The extension portion 4a is configured to prevent the lubricating oil from scattering to the oil filler 10. Furthermore, the bottom plate 4 is provided with a small diameter oil drop hole 17 for the gas-liquid separation chamber 5.

In this configuration, the blow-by gas in the cylinder head cover 1 is subjected to the gas-liquid separation action in the gas-liquid separation chamber 13 of the oil filler cap 11 in the low load region where the opening degree of the throttle valve is small, and then the first blow-by gas. It is extracted into the intake system downstream of the carburetor 7 via the passage 15. On the other hand, in the high load region where the opening of the throttle valve is large, the gas-liquid separation chamber 13 of the oil filler cap 11 receives the gas-liquid separation action, and then the downstream side of the carburetor 7 via the first blow-by gas passage 15. At the same time as being extracted into the intake system in the blow-by gas passage 16
Through the gas-liquid separation chamber 5 in the cylinder head cover 1 and through the second blow-by gas passage 9 into the intake system upstream of the carburetor 7.

By the way, the carburetor 7 is passed through the second blow-by gas passage 9.
The blow-by gas extracted in the intake system on the upstream side is first subjected to the gas-liquid separation action in the gas-liquid separation chamber 13 in the oil filler cap 11, and then the gas-liquid separation in the oil filler cap 11. When flowing out from the chamber 13 through the blow-by gas passage 16,
The oil mist entrained therewith is subjected to a separation action that is removed by the suction action from the first blow-by gas passage 15 to the downstream side of the carburetor 7, and further, the gas-liquid separation chamber 5 in the cylinder head cover 1 is separated. It is separated.

In this case, 15 in the first blow-by gas passage.
Gas-liquid separation chamber 13 of the oil filler cap 11 in
The opening to the inside and the opening to the inside of the gas-liquid separation chamber 13 of the oil filler cap 11 in the blow-by gas passage 16 are opposed to each other, while the inside of the gas-liquid separation chamber 13 of the oil filler cap 11 is obstructed. The plate 12 is attached to the oil filler cap 11 in the blow-by gas passage 16.
Of the oil filler cap 11 in the first blow-by gas passage 15 is provided below the opening of the oil filler cap 11 into the gas-liquid separation chamber 13. The blow-by gas flowing out of the gas-liquid separation chamber 13 through the blow-by gas passage 16 can be strongly sucked from the first blow-by gas passage 15 to the downstream side of the carburetor 7. Liquid separation chamber 1
The oil mist entrained in the blow-by gas flowing out of the blow-by gas passage 16 from the No. 3 can be separated so as to be effectively sucked from the first blow-by gas passage 15 to the downstream side of the vaporizer 7.

[Brief description of drawings]

1 is a plan view and FIG. 2 is an enlarged sectional view taken along the line II-II of FIG. 1 ... Cylinder head cover, 2 ... Cylinder head,
3 ... Box, 4 ... Bottom plate, 5 ... Gas-liquid separation chamber, 6 ...
... Throttle valve, 7 ... carburetor, 8 ... air cleaner,
9 ... second blow-by gas passage, 10 ... oil filler, 11 ... oil filler cap, 13 ... gas-liquid separation chamber, 14 ... intake manifold, 15 ... first blow-by gas passage, 16 ... blow-by gas aisle.

Claims (1)

[Scope of utility model registration request] 1. A gas-liquid separation chamber communicating with the inside of the cylinder head cover is formed in an oil filler cap for an oil filler provided on a cylinder head cover covering the upper surface of the cylinder head, and the gas-liquid separation chamber is provided downstream of the vaporizer. In the internal combustion engine configured by connecting the first blow-by gas passage to the intake system on the side of the cylinder head cover, a gas-liquid separation chamber that is not in communication with the inside of the cylinder head cover is formed on the inner surface of the cylinder head cover, and the gas-liquid in the cylinder head cover is formed. A second blow-by gas passage to the intake system upstream of the vaporizer is connected to the separation chamber, and the gas-liquid separation chamber of the oil filler cap and the non-communicating gas-liquid separation chamber in the cylinder head cover are blow-by. An oil filler connected through a gas passage and in the first blow-by gas passage And opening into the gas-liquid separation chamber of the cap, while opposing the opening to the gas-liquid separation chamber of the oil filler cap in the blow-by gas passage,
A baffle is provided in the gas-liquid separation chamber of the oil filler cap, an opening of the oil filler cap in the blow-by gas passage into the gas-liquid separation chamber, and a baffle plate in the gas-liquid separation chamber of the first blow-by gas passage into the gas-liquid separation chamber. A blow-by gas extraction device for an internal combustion engine, wherein the blow-by gas extraction device is provided below the opening.