JPH0587213U - Blow-by gas treatment device for internal combustion engine with exhaust turbocharger - Google Patents

Abstract

(57) [Abstract] [Purpose] In an internal combustion engine 20 in which an exhaust gas turbocharger 31 and a throttle valve 33 are provided in an intake path 30, a valve operating mechanism chamber 25 and a crank chamber 26 are provided in a low load operation range. When new air is introduced to perform ventilation, the amount of oil that disappears together with the ventilation air and blow-by gas is reduced. [Structure] The valve mechanism chamber 25 is provided in a portion of the intake path 30 upstream of the exhaust turbocharger via a first blow-by gas passage 35, and the crank chamber 26 is provided via a second blow-by gas passage 38. Throttle valve 3 in the intake passage 30
3, a flow control valve 39 that communicates with each of the downstream side portions and is opened in the second blow-by gas passage when the intake negative pressure is small is opened. The auxiliary blow-by gas passage 40 from the side portion is communicated with a portion of the intake passage 30 upstream of the exhaust turbocharger, and the check valve is opened in the auxiliary blow-by gas passage only in the direction toward the intake passage. 41 is provided.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a device for sucking and processing blow-by gas generated in a crank chamber and a valve mechanism chamber of an internal combustion engine having an exhaust turbocharger in its intake system by sucking it into the intake system of the internal combustion engine. It is a thing.

[0002]

[Prior Art]

 In an internal combustion engine equipped with an exhaust turbocharger in the intake system, the downstream side of the exhaust turbocharger in the intake system may become atmospheric pressure or higher in a high load operation range. Blow-by gas in the valve mechanism chamber on the upper surface of the cylinder head and in the crank chamber below the cylinder block cannot be sucked by using the intake negative pressure.

Therefore, conventionally, as shown in FIG. 3, an air cleaner 4, an exhaust turbo supercharger 5, an intercooler 6, and an intercooler 6 are sequentially arranged in an intake path 3 to an internal combustion engine 1 from an upstream side to an intake manifold 2. In an internal combustion engine with an exhaust turbocharger that is provided with a throttle valve 7, an oil separator 9 is provided in a valve mechanism chamber 8 on the upper surface of a cylinder head, and a first blow-by gas passage 10 from this oil separator 9 is A check valve 11 connected to the intake manifold 2 is provided in the first blow-by gas passage 10 so as to open only in the direction toward the intake manifold 2, while the oil communicating with the crank chamber 12 below the cylinder block is provided. A separator 13 is provided, and the second blow-by gas passage 14 from the oil separator 13 is connected to the exhaust turbocharger 5. It is configured to connect to the suction side of the blower compressor.

Then, in a low load operation range in which the opening of the throttle valve 7 is small, the intake negative pressure in the intake manifold 2 increases toward the vacuum side, so that the blow-by gas in the valve operating mechanism chamber 8 is transferred to the first blow-by gas passage. On the other hand, by introducing new air from the air cleaner 4 into the crank chamber 12 through the second blow-by gas passage 14, both the crank chamber 12 and the valve mechanism chamber 8 are extracted into the crank chamber 12 through the second blow-by gas passage 14. Ventilate.

Further, in a high load operation range where the opening degree of the throttle valve 7 is increased, negative pressure is generated on the suction side of the blower compressor in the exhaust turbocharger 5, so that the inside of the crank chamber 12 is reduced. The blow-by gas is extracted through the second blow-by gas passage 14.

[0006]

[Problems to be solved by the device]

 However, in this conventional device, the blow-by gas in the valve mechanism chamber 8 is extracted through the first blow-by gas passage 10 in the low load operation range in which the opening of the throttle valve 7 is small, while the air cleaner 4 is used. Of the new air introduced into the crank chamber 12 through the second blow-by gas passage 14. The new air introduced into the crank chamber 12 causes the oil in the valve operating mechanism chamber 8 to move to the valve operating mechanism. A large amount of oil mist is generated in the valve mechanism chamber by blowing up the oil drop passage 15 from the chamber 8 into the crank chamber 12 from below to the inside of the valve mechanism chamber 8. In addition to this, since both the blowby gas and the new air flow from the valve mechanism chamber toward the first blowby gas passage, they flow out from the first blowby gas passage. The amount of oil lost by accompanying the blow-by gas was the Word cormorants problems when increasing.

In order to reduce the amount of oil that accompanies the blow-by gas from the first blow-by gas passage, a large oil that can reliably collect oil mist in the first blow-by gas passage. A separator may be provided, but this would lead to an increase in weight and an increase in size of the internal combustion engine. The present invention aims to solve the above problems with a simple configuration.

[0008]

[Means for Solving the Problems] In order to achieve this technical problem, the present invention provides an exhaust system turbocharger and a throttle valve in an intake system, an exhaust turbocharger upstream and a throttle valve downstream. In the internal combustion engine configured as described above, the valve operating mechanism chamber on the upper surface of the cylinder head communicates with a portion of the intake system upstream of the exhaust turbocharger through the first blow-by gas passage, while The crank chamber in the lower part of the block communicates with a portion of the intake system downstream of the throttle valve via the second blowby gas passage, and the intake negative pressure downstream of the throttle valve is provided in the second blowby gas passage. Relatedly, the second blow-by gas passage is closed when the intake negative pressure is small on the atmospheric pressure side, and the second blow-by gas passage is opened when the intake negative pressure is large on the vacuum side. A flow control valve is provided, and an auxiliary blow-by gas passage branched from a position downstream of the flow control valve in the second blow-by gas passage is connected to a portion of the intake system upstream of the exhaust turbocharger. A non-return valve is provided in the auxiliary blow-by gas passage so that it opens only in the direction toward the intake system.

[0009]

[Work]

 In this configuration, in the low load operation range in which the opening of the throttle valve is small, the intake negative pressure on the downstream side of the throttle valve is large on the vacuum side, and the flow control valve in the second blow-by gas passage becomes While the blow-by gas passage is open, there is no negative pressure in the intake system upstream of the exhaust turbocharger.

In addition to this, the check valve is provided in the auxiliary blow-by gas passage, so that the blow-by gas in the crank chamber is sucked by the second blow-by gas due to the intake negative pressure on the downstream side of the throttle valve. It is extracted downstream from the throttle valve via the gas passage. On the other hand, new air in a portion of the intake system on the upstream side of the exhaust turbocharger is introduced through the first blow-by gas passage, and then introduced into this valve mechanism chamber. By introducing the new air into the crank chamber by flowing downward from the oil drop passage, both the valve operating chamber and the crank chamber are ventilated. That is, the new air for ventilating does not flow upward in the oil drop passage from the bottom as in the above-mentioned conventional case, and does not flow upward in the oil drop passage, and is parallel to the oil flow in the oil drop passage. Since it flows downward from above, it is possible to reliably reduce the occurrence of oil mistakes by introducing new air for ventilation.

Further, in a high load operation range in which the opening of the throttle valve is large, the flow rate control valve in the second blow-by gas passage shuts off the second blow-by gas passage, while the exhaust turbocharger in the intake system is closed. Since a negative pressure is generated in a portion on the upstream side, the blow-by gas in the crank chamber is extracted through the auxiliary blow-by gas passage, and a part of the blow-by gas in the valve mechanism chamber is part of the first blow-by gas. It is extracted through the passage. By providing a check valve in the first blow-by gas passage, which opens only in the direction toward the valve operating mechanism chamber, all of the blow-by gas in the valve operating mechanism chamber is transferred to the crank chamber through the oil drop passage. It may be configured such that the gas is extracted from the auxiliary blow-by gas passage together with the blow-by gas in the crank chamber.

[0012]

[Effect of the device]

 Therefore, according to the present invention, when ventilating the valve operating chamber and the crank chamber by introducing new air, the amount of oil that disappears together with the ventilation air and blow-by gas can be increased in size. In other words, in other words, there is an effect that the internal combustion engine can be reliably reduced without increasing the weight and increasing the size thereof.

[0013]

【Example】

 Embodiments of the present invention will be described below with reference to the drawings. In the figure, reference numeral 20 is an internal combustion engine in which an oil pan 22 is fastened to a lower portion of a cylinder block 21, a cylinder head 23 is fastened to an upper surface of the cylinder block 21, and a head cover 24 is fastened to an upper surface of the cylinder head 23. In this internal combustion engine 20, oil is dropped to allow oil in the valve mechanism chamber 25 in the head cover 24 to flow down to the oil pan 22 via the crank chamber 26 in the lower portion of the cylinder block 21. A passage 27 is provided.

Reference numeral 28 denotes an air cleaner having a filter element 28 a built therein. An intake air passage 30 extending from the air cleaner 28 to the intake manifold 29 for the internal combustion engine 1 is sequentially exhaust gas turbocharged from the upstream side. A machine 31, an intercooler 32, and a throttle valve 33 are provided. An oil separator 34 is provided in the head cover 24, and the first blow-by gas passage 35 from the oil separator 34 is connected to a portion of the intake passage 30 upstream of the exhaust turbocharger 31. A check valve 36 is provided in the first blow-by gas passage 14 so as to open only in the direction toward the head cover 24.

On the other hand, the cylinder block 21 is provided with an oil separator 37 that communicates with the inside of the crank chamber 26, and a second blow-by gas passage 38 from the oil separator 37 is introduced into the intake air on the downstream side of the throttle valve 33. A flow rate control valve 39 is provided in the second blow-by gas passage 38 by being connected to the chamber 29a or the like in the manifold 29.

The flow control valve 39 is configured as shown in FIG. That is, the flow control valve 39 has a valve body 39c provided in the valve box 39a so as to project the inlet pipe 39b and contact the upper end surface of the inlet pipe 39b so as to close the inlet pipe 39b. The valve body 39c is configured to be biased by a spring 39d in a direction in which the passage cross-sectional area between the tip portion of the valve body 39c and the outlet pipe 39e is increased.

An auxiliary blow-by gas passage 40 branched from a portion of the second blow-by gas passage 38 upstream of the flow rate control valve 39 is provided in the intake passage 30 upstream of the exhaust turbocharger 31. A check valve 41 is provided in the auxiliary blow-by gas passage 40, which is connected to the portion and is opened only in the direction toward the intake passage 30. In this configuration, in the low load operation range where the opening of the throttle valve 33 is small, the intake negative pressure in the intake manifold 29 downstream from the throttle valve 33 is large on the vacuum side, and this large intake negative pressure is the second blow-by gas passage. 38 is transmitted to the flow control valve 39 in the valve 38, and the valve body 18d in the flow control valve 39 is moved backward by the large intake negative pressure so as to move away from the inlet pipe 39b against the spring 18e, and the second blow-by valve While opening the gas passage 38, a negative pressure is not generated in a portion of the intake passage 30 upstream of the exhaust turbocharger 31.

In addition to this, the check valve 41 is provided in the auxiliary blow-by gas passage 40, so that the blow-by gas in the crank chamber 26 is discharged by the intake negative pressure on the downstream side of the throttle valve 33. It is extracted into the intake manifold 29 via the two blow-by gas passage 38. On the other hand, new air in a portion of the intake passage 30 upstream of the exhaust turbocharger 31 is introduced into the valve mechanism chamber 25 via the first blowby gas passage 35, and the valve mechanism chamber 25 The fresh air introduced into the valve 25 flows downward from the oil drop passage 27 into the crank chamber 26 to ventilate both the valve mechanism chamber 25 and the crank chamber 26.

Further, in the high load operation range where the opening degree of the throttle valve 33 is large, the flow rate control valve 39 in the second blow-by gas passage 38 becomes small so that the intake negative pressure in the intake manifold 29 approaches the atmospheric pressure. Alternatively, when the pressure becomes equal to or higher than the atmospheric pressure, the second blow-by gas passage 38 is shut off, while a negative pressure is generated in a portion of the intake passage 30 upstream of the exhaust turbocharger 31, so that the crank chamber 26 has a negative pressure. The blow-by gas is extracted via the auxiliary blow-by gas passage 40, and a part of the blow-by gas in the valve mechanism chamber 25 is extracted via the first blow-by gas passage 35.

In this case, as shown in the drawing, the check valve 36 that opens only in the direction toward the valve operating mechanism chamber 25 is provided in the first blow-by gas passage 35, thereby operating the valve operating valve. The blow-by gas in the mechanism chamber 25 may be entirely introduced into the crank chamber 26 via the oil drop passage 27 and then extracted together with the blow-by gas in the crank chamber 26 from the auxiliary blow-by gas passage 40. ..

Further, the flow rate control valve 39 is configured to reduce the passage cross-sectional area in the second blow-by gas passage 38 as the intake negative pressure increases toward the vacuum side. At, the rotation is prevented from becoming unstable.

[Brief description of drawings]

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

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

FIG. 3 is a diagram showing a conventional example.

[Explanation of symbols]

 20 Internal Combustion Engine 21 Cylinder Block 22 Oil Pan 23 Cylinder Head 24 Head Cover 25 Valve Mechanism Chamber 26 Crank Chamber 27 Oil Drop Passage 28 Air Cleaner 29 Intake Manifold 30 Intake Passage 31 Exhaust Turbocharger 33 Throttle Valve 35 First Blow-by Gas Passage 38 Second blow-by gas passage 39 Flow control valve

Claims (1)

[Scope of utility model registration request] 1. An internal combustion engine having an exhaust turbocharger and a throttle valve in an intake system, an exhaust turbocharger upstream and a throttle valve downstream, and a valve mechanism on the upper surface of a cylinder head. The chamber communicates with a portion of the intake system upstream of the exhaust turbocharger via the first blow-by gas passage, while the crank chamber below the cylinder block receives the intake system via the second blow-by gas passage. Of the throttle valve is connected to the downstream side,
In relation to the intake negative pressure downstream of the throttle valve in the second blow-by gas passage, the second blow-by gas passage is closed when the intake negative pressure is small on the atmospheric pressure side, and the intake negative pressure is on the vacuum side. A flow rate control valve that opens the second blow-by gas passage when it is large is provided, and an auxiliary blow-by gas passage branched from a portion of the second blow-by gas passage downstream of the flow rate control valve is provided in the intake system. An exhaust turbo supercharger characterized by being provided with a check valve communicating with an upstream side of the exhaust turbo supercharger and opening in the auxiliary blow-by gas passage only in a direction toward an intake system. Blow-by gas treatment device for internal combustion engine.