JP2585444Y2 - Equipment for treating blow-by gas in internal combustion engines - Google Patents

Description

[Detailed description of the invention]

[0001]

The present invention relates to a blow-by gas generated in a crank chamber and a valve operating chamber of an internal combustion engine.
The present invention relates to an apparatus for performing suction and processing on an intake system of the internal combustion engine.

[0002]

2. Description of the Related Art Conventionally, as one type of blow-by gas processing apparatus of this type, a valve operating mechanism chamber on the upper surface of a cylinder head is connected to a portion of the intake system upstream of a throttle valve through a first blow-by gas passage. On the other hand, in the low-load operation range where the opening of the throttle valve is small, the crank chamber in the lower part of the cylinder block communicates with the portion of the intake system downstream of the throttle valve through the second blow-by gas passage. After the blow-by gas in the valve mechanism is guided to the crank chamber via an oil-dropping passage from the valve mechanism to the crank chamber, the second blow-by gas path is connected to the intake system together with the blow-by gas in the crank chamber. On the other hand, air is introduced into the valve mechanism chamber through the first blow-by gas passage to ventilate, and a throttle is provided. In the high load operation range where the opening degree of the valve is large, the blow-by gas in the valve mechanism chamber is sucked into the intake system through the first blow-by gas passage, and the blow-by gas in the crank chamber is sucked into the intake system through the second blow-by gas passage. There is one configured.

However, in this system, a large amount of air and blow-by gas is sucked into the intake system through the second blow-by gas passage in a low-load operation range where the opening of the throttle valve is small. The rotation in the load operation range becomes unstable. Therefore, Japanese Utility Model Application Laid-Open No. 63-164514 and Japanese Utility Model Application Laid-Open No.
No. 9 discloses that, when a normally closed intake vacuum pressure on the downstream side of the throttle valve increases toward the vacuum side during the second blow-by gas passage from the crank chamber to the downstream side of the throttle valve, the second blow-by gas passage in the second blow-by gas passage is closed. It has been proposed to stabilize low-load operation by providing a flow control valve (PCV) that operates to reduce the passage cross-sectional area.

[0004]

However, the flow control valve (PCV) in this prior art completely closes the passage cross-sectional area in the second blow-by gas passage when the intake negative pressure downstream of the throttle valve is close to the atmospheric pressure. As the intake negative pressure increases toward the vacuum side, the passage cross-sectional area of the second blow-by gas passage is once increased and then reduced.

Accordingly, this flow control valve is fully closed when the intake negative pressure downstream of the throttle valve is close to the atmospheric pressure in a high-load operation range where the opening of the throttle valve is large. The blow-by gas in the chamber flows into the valve mechanism via the oil drop passage without being extracted through the second blow-by gas passage, and flows into the first blow-by gas passage together with the blow-by gas in the valve drive chamber. Is extracted via

That is, in the high load operation range, despite the large amount of blow-by gas in the crank chamber and the valve operating chamber, the blow-by gas in the crank chamber travels through the oil drop passage toward the valve operating chamber. By blowing up from below, a large amount of oil mist is generated in the valve mechanism chamber. In addition to this,
Since a large amount of blow-by gas flows from the valve mechanism chamber toward the first blow-by gas passage, there is a problem that the amount of oil that disappears with the blow-by gas flowing out from the first blow-by gas passage increases.

In addition, there is also a problem that icing is generated at the position of the throttle valve when a large amount of blow-by gas containing moisture passes through the position of the throttle valve. In order to reduce the amount of oil accompanying the blow-by gas from the first blow-by gas passage, the first
It is sufficient to provide a large oil separator capable of reliably collecting oil mist in the blow-by gas passage. However, this leads to an increase in weight and an increase in size of the internal combustion engine.

An object of the present invention is to provide a blow-by gas processing apparatus which can solve the above-mentioned problem with a simple configuration without increasing the size of an internal combustion engine.

[0009]

In order to achieve this technical object, the present invention provides a method of manufacturing a valve operating system in which the upper side of a cylinder head is upstream of a throttle valve in a suction system through a first blow-by gas passage. In the internal combustion engine, which communicates with a part of the intake system via a second blow-by gas passage to a part of the intake system downstream of the throttle valve, In the first blow-by gas passage, a check valve that opens only in the direction toward the valve operating chamber is provided, while in the second blow-by gas passage from the crank chamber, intake air downstream of the throttle valve is provided. In relation to the pressure, when the intake negative pressure is smaller on the atmospheric pressure side, the passage cross-sectional area of the second blow-by gas passage increases, and as the intake negative pressure increases on the vacuum side, the second blow-by gas increases. Providing a flow control valve so as to reduce the cross-sectional area of Baigasu passage. It was constituted say ".

[0010]

[Work] In this configuration, in a low load operation range where the opening of the throttle valve is small, the intake negative pressure downstream of the throttle valve is large on the vacuum side, and the flow control valve in the second blow-by gas passage is The cross-sectional area of the second blow-by gas passage is reduced. Accordingly, the amount of blow-by gas and air sucked from the crank chamber to the downstream side of the throttle valve via the second blow-by gas passage can be regulated to a small amount, while the upstream side of the throttle valve is provided in the valve mechanism chamber. Can be introduced through the first blow-by gas passage, and the ventilation in the valve mechanism chamber and the ventilation in the crank chamber are performed.

In a high-load operation range where the opening of the throttle valve is large, the intake negative pressure downstream of the throttle valve decreases toward the atmospheric pressure, so that the flow control valve in the second blow-by gas passage becomes By increasing the passage cross-sectional area of the second blow-by gas passage, the amount of blow-by gas sucked from the crank chamber to the downstream side of the throttle valve via the second blow-by gas passage increases. Can be prevented from blowing up from the crank chamber into the valve operating chamber via the oil drop passage, while the check valve is provided in the first blow-by gas passage from the valve operating chamber, so that this valve operating mechanism can be prevented. The blow-by gas sucked from the chamber through the first blow-by gas passage to the upstream side of the throttle valve is eliminated, and the blow Igasu, said After introduced into the crank chamber from the oil discharge passage can be extracted downstream of the throttle valve through the second blow-by gas passage.

[0012]

Therefore, according to the present invention, the amount of oil that disappears together with the blow-by gas in the high-load operation range can be reduced without increasing the size of the oil separator in the valve mechanism chamber, in other words, in the internal combustion engine. This has the effect of reliably reducing the occurrence of icing at the location of the throttle valve without incurring an increase in weight and size.

[0013]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. In the figure, reference numeral 1 indicates that an oil pan 3 is fastened to a lower portion of a cylinder block 2 while a cylinder head 4 is fastened to an upper surface of the cylinder block 2.
1 shows an internal combustion engine in which a head cover 5 is fastened to an upper surface of the engine. In the internal combustion engine 1, oil in a valve mechanism chamber 6 in the head cover 5 is supplied through a crank chamber 7 in a lower portion of the cylinder block 2. Bread 3
There is provided an oil drop passage 8 for flowing down.

Reference numeral 9 denotes an air cleaner having a built-in filter element 9a. The air cleaner 9 is connected to an intake manifold 12 for the internal combustion engine 1 via an intake pipe 11 with a throttle valve 10. And
An oil separator 13 is provided in the head cover 5, and a first blow-by gas passage 14 from the oil separator 13 is connected to an air cleaner 9 or the like upstream of the throttle valve 10. A check valve 15 configured to open only in the direction toward the head cover 5 is provided.

On the other hand, the cylinder block 2 is provided with an oil separator 16 communicating with the inside of the crank chamber 7.
A second blow-by gas passage 17 from the oil separator 16 is connected to a chamber 12a or the like in the intake manifold 12 downstream of the throttle valve 10, and a flow control valve 18 is provided in the second blow-by gas passage 17. .

The flow control valve 18 is configured as shown in FIG. That is, the flow control valve 18 is provided with a valve body 18d which projects into an inlet pipe 18b provided with a through hole 18c in a valve box 18a and which comes into contact with an upper end surface of the inlet pipe 18b. The body 18d is configured to be urged by a spring 18e in a direction to increase the passage cross-sectional area between the distal end portion of the valve body 18d and the outlet pipe 18f.

In this configuration, in a low load operation range where the opening of the throttle valve 10 is small, the throttle valve 10
The suction negative pressure in the downstream intake manifold 12 is large on the vacuum side, and this large suction negative pressure is transmitted to the flow control valve 18 in the second blow-by gas passage 17, and the valve element 18d of the flow control valve 18 Due to the large intake negative pressure, as shown by the two-dot chain line in FIG.
To reduce the cross-sectional area of the passage with the outlet pipe 18f. Accordingly, the amount of blow-by gas and air taken into the intake manifold 12 downstream of the throttle valve 10 from the crank chamber 7 via the second blow-by gas passage 17 can be regulated to a small amount. The air in the air cleaner 9 on the upstream side of the throttle valve 10 can be introduced through the first blow-by gas passage 14 to perform ventilation in the valve mechanism chamber 6 and the crank chamber 7.

In a high-load operation range where the opening of the throttle valve 10 is large, the intake negative pressure in the intake manifold 12 downstream of the throttle valve decreases to the atmospheric pressure side, so that the second blow-by gas passage 17 In the flow control valve 18, the valve element 18d returns to the original position by the spring 18e, and the passage cross-sectional area from the through hole 18c in the inlet pipe 18b to the outlet pipe 18f increases.

Accordingly, the amount of blow-by gas sucked from the crank chamber 7 to the intake manifold 12 downstream of the throttle valve via the second blow-by gas passage 17 increases, so that the blow-by gas in the crank chamber 7 is From the valve operating mechanism chamber 6 via an oil drop passage 8
While the check valve 15 is provided in the first blow-by gas passage 14 from the valve mechanism chamber 6, the check valve 15 is provided through the first blow-by gas passage 14 from the valve mechanism chamber 6. After the blow-by gas sucked upstream from the throttle valve 10 is eliminated and the blow-by gas in the valve mechanism chamber 6 is introduced into the crank chamber 7 from the oil drop passage 8, the second blow-by gas passage 1
7 to the intake manifold 12.

[Brief description of the drawings]

FIG. 1 is a diagram showing an embodiment of the present invention.

FIG. 2 is an enlarged view of a flow control valve.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Internal combustion engine 2 Cylinder block 3 Oil pan 4 Cylinder head 5 Head cover 6 Valve mechanism chamber 7 Crank chamber 8 Oil drop passage 9 Air cleaner 10 Throttle valve 11 Intake pipeline 12 Intake manifold 14 First blow-by gas passage 15 Check valve 17 2 blow-by gas passage 18 flow control valve

Claims (1)

(57) [Scope of request for utility model registration] A valve train inside an upper surface of a cylinder head communicates with a portion of the intake system upstream of a throttle valve through a first blow-by gas passage. in an internal combustion engine comprising communicating the throttle valve at a site downstream of the intake system via the 2 blow-by gas passage, the first blow-by gas passage in from the valve operating mechanism chamber, the dynamic
A check valve is provided that opens only in the direction to the valve mechanism chamber.On the other hand, in the second blow-by gas passage from the crank chamber, in relation to the intake negative pressure downstream of the throttle valve,
A flow rate in which the passage cross-sectional area of the second blow-by gas passage is increased when the intake negative pressure is smaller on the atmospheric pressure side, and the passage cross-sectional area of the second blow-by gas passage is reduced as the intake negative pressure increases on the vacuum side. An apparatus for treating blow-by gas in an internal combustion engine, comprising a control valve.