JP2013002406A - Intake device of internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To keep an engine and an intake duct in excellent conditions without continuing to store a large amount of liquid inside the bottom of an intercooler that is the lowermost of the intake duct.SOLUTION: A bypass flow path that guides a clean air having passed through an air cleaner 1 to a second intake passage 62 downstream in the intake stream direction than a throttle valve 7 through an oil storage part 65, and an oil discharge mechanism having a bypass valve 14 disposed to be positioned above the oil storage part 65 in the gravity direction in this bypass passage are provided. By this arrangement, the oil stored in the oil storage part 65 that is discharged to the oil storage part 65 via a drain pipe 11 from the bottom part 51 of a cooler case 3 is introduced to the second intake passage 62 downstream in the intake stream direction than the throttle valve 7 via the bypass pipe 12, and the oil introduced to the second intake passage 62 is sucked into the combustion chambers of respective cylinders of the engine E.

Description

  The present invention relates to an intake device for an internal combustion engine in which liquid accumulated in the lowermost part of an intake passage for supplying intake air to a combustion chamber of the internal combustion engine is introduced into an intake passage downstream of a throttle valve. The present invention relates to an intake device for an internal combustion engine in which liquid accumulated in the lowermost part of an intercooler that cools intake air compressed by a feeder is introduced into an intake passage downstream of a throttle valve.

[Conventional technology]
Conventionally, an internal combustion engine (engine) including an intercooler that cools intake air that has been compressed by a turbocharger compressor and heated to a high temperature is known. The intercooler is generally composed of a pair of tanks and a core installed between these tanks.
Further, the engine has an EGR gas recirculation passage having one end opened downstream of the turbine of the turbocharger and the other end opened upstream of the compressor of the turbocharger. An exhaust gas circulation device (EGR system) that recirculates the EGR gas that is a part to the intake passage is mounted. An EGR cooler and an EGR control valve are provided in the EGR gas recirculation path.

In this case, the EGR gas flowing through the EGR gas recirculation path is cooled by taking heat away from the EGR cooler, the moisture in the EGR gas is condensed to generate condensed water, and the condensed water is generated by the EGR gas flow. There is a possibility of flowing from the gas recirculation path to the intake path. When the condensed water that has flowed into the intake passage flows into the intercooler, when the pair of tanks of the intercooler are arranged on the upper side and the lower side in the vertical direction, respectively, the bottom of the tank on the lower side (condensate storage) There is a problem that liquefied condensed water accumulates in the inside) and stagnates.
Even if the EGR system is not installed, the intercooler is a heat exchanger that cools the intake air compressed by the compressor, so that the condensed water generated in the intercooler is the bottom of the tank (condensed water). There is a problem that it accumulates in the storage part) and stagnates.

In addition, the blow-by gas that is blown into the crankcase from the gap between the piston and the cylinder of the engine is discharged into the intake passage as purge gas without being released into the atmosphere, and is re-burned in the combustion chamber of the engine. A reduction device is installed.
By the way, for blow-by gas introduced into the intake passage and intake air flowing from the turbocharger compressor to the intercooler, engine oil that lubricates the sliding portion of the engine or oil that lubricates the sliding portion of the turbocharger ( Engine oil) is mixed in mist. Further, unburned fuel contained in the EGR gas introduced into the intake passage drifts in a mist form in the intake passage.
Then, blow-by gas, EGR gas, and intake air are deprived of heat by the intercooler and cooled, and oil mist contained in the blow-by gas, EGR gas, and intake air is liquefied to become oil. And when a pair of tanks of the intercooler are respectively arranged on the upper side and the lower side in the vertical direction, the oil liquefied at the bottom (in the oil storage part) of the tank on the lower side is accumulated and stagnated in the same manner as the condensed water. There's a problem.

Therefore, one end of the drain pipe is connected to the oil reservoir located at the bottom of the intercooler for the purpose of sucking up the oil accumulated in the intercooler into the combustion chamber of the engine using the negative intake pressure. An intake device in which the other end of the pipe is connected to the downstream side of the intake throttle valve is known (see, for example, Patent Documents 1 and 2).
In the intake device described in Patent Document 1, a drain pipe that returns oil accumulated in the oil reservoir of the intercooler to the downstream side of the intake throttle valve is arranged in parallel with the intake duct. One end of the drain pipe passes through the bottom wall of the tank on the lower side of the intercooler and is inserted into the oil reservoir. And, at one end portion of the drain pipe, an intake port that sucks in intake air when the intake throttle valve is closed and an oil intake hole that sucks oil accumulated in the oil reservoir when the intake throttle valve is closed are formed. ing.

[Conventional technical problems]
By the way, in the intake device described in Patent Documents 1 and 2, the object is to suck up the oil accumulated in the intercooler into the combustion chamber of the engine by an intake negative pressure at an arbitrary timing by an optimum flow rate. Thus, the flow rate of the oil returned from the drain pipe to the intake passage is controlled by an opening / closing operation in the middle of the drain pipe communicating the oil reservoir located at the lowermost part of the intercooler and the intake passage downstream of the intake throttle valve. It is conceivable to provide an electromagnetic flow control valve (bypass valve).
Note that the intake device described in Patent Document 2 discloses a configuration in which a valve is installed in the middle of a drain pipe.

In such a case, when the oil accumulated in the intercooler is sucked up, the oil passes through the electromagnetic flow control valve. Specifically, oil passes between a valve that is a valve body and a valve seat on which the valve can be seated.
As a result, oil adheres to the periphery of the valve (valve seat or flow path wall surface), and deposits having adhesive properties accumulate around the valve. In addition, the adhesion of deposits or the like around the valve causes a problem that the accuracy of the valve operation responsiveness cannot be ensured, and it becomes impossible to control an appropriate amount of oil.

JP 2005-226476 A French Patent Application Publication No. 2553827

An object of the present invention is to provide an intake device for an internal combustion engine that can keep the internal combustion engine and the intake duct in a good state without continuously storing a large amount of liquid in the intake duct.
Another object of the present invention is to provide an intake device for an internal combustion engine that can guarantee the accuracy of operation responsiveness of the flow control valve for a long period of time.
It is another object of the present invention to provide an intake device for an internal combustion engine capable of controlling an appropriate amount of liquid discharged from the intake duct into a combustion chamber of the internal combustion engine so as not to hinder the internal combustion engine.

The invention according to claim 1 (intake device of an internal combustion engine) includes an intake duct through which intake air supplied to a combustion chamber of the internal combustion engine flows, an intake throttle valve for controlling the flow rate of intake air flowing through the intake duct, and an intake duct Liquid discharging means for introducing the liquid accumulated therein to the downstream side in the air flow direction from the intake throttle valve and discharging the liquid into the combustion chamber of the internal combustion engine.
This intake device includes an intake (duct) structure formed such that the lowermost portion of the intake duct in the gravity direction is positioned upstream of the intake throttle valve in the air flow direction.
The liquid discharge means includes a storage part for collecting liquid discharged from the lowest part in the gravity direction of the intake duct, an air flow from the intake passage on the upstream side in the air flow direction from the intake throttle valve via the storage part, and the air flow from the intake throttle valve. A bypass passage for guiding the fluid to the intake passage on the downstream side in the direction, and a flow rate control valve for controlling the flow rate of the fluid flowing through the bypass passage.
The flow control valve is installed in the bypass flow path so as to be located in the gravity direction lowermost part of the intake duct and in the gravity direction above the storage part.

According to the first aspect of the present invention, the intake throttle valve is configured such that the lowermost portion in the gravity direction of the intake duct is positioned upstream of the intake throttle valve in the air flow direction. The liquid flowing into the intake passage upstream of the air flow direction or generated in the intake passage upstream of the intake throttle valve is the gravity direction of the intake duct (intake path of the internal combustion engine) Accumulate at the bottom.
In addition, by providing the liquid discharge means in the intake duct, the liquid that has accumulated (accumulated) at the lowest part in the gravity direction of the intake duct is allowed to flow into the intake passage downstream of the bypass flow path and the intake throttle valve in the air flow direction. A liquid discharge path for discharging into the combustion chamber of the internal combustion engine is formed.
When the intake throttle valve is closed and the flow control valve is opened, intake negative pressure is introduced into the bypass flow path from the intake passage on the downstream side of the intake throttle valve in the air flow direction. As a result, the liquid accumulated in the lowermost part of the intake duct in the gravity direction is introduced together with the fluid into the intake passage downstream of the intake throttle valve in the air flow direction via the bypass flow path. The liquid introduced into the intake passage downstream of the intake throttle valve in the air flow direction is sucked up into the combustion chamber of the internal combustion engine.
Therefore, the internal combustion engine and the intake duct can be maintained in a good state without continuously storing a large amount of liquid in the intake duct.

  Further, in the intake structure configured such that the lowermost gravitational direction of the intake duct is positioned upstream of the intake throttle valve in the airflow direction, the lowermost gravitational direction of the intake duct and the upper part of the intake duct are positioned above the gravitational direction. By installing a flow control valve in the bypass flow path, the liquid accumulated in the lowest part of the intake duct in the gravitational direction and in the storage portion is placed downstream of the intake throttle valve in the air flow direction via the bypass flow path. Even when the gas is introduced into the intake passage and discharged into the combustion chamber of the internal combustion engine, the liquid can be prevented from passing through the flow rate control valve installed in the bypass flow path. This makes it difficult for deposits and other sticky substances to adhere to the flow control valve, so that the accuracy of the operation responsiveness of the flow control valve can be ensured for a long time. Therefore, an appropriate amount of liquid discharged from the intake duct to the combustion chamber of the internal combustion engine can be stably controlled for a long period of time so as not to hinder the internal combustion engine.

Further, the pressure difference between the intake passage upstream of the intake throttle valve in the air flow direction and the intake passage downstream of the intake throttle valve in the air flow direction, that is, the pressure difference between the intake throttle valve upstream and downstream (intake negative pressure). ), The liquid accumulated in the lowermost part of the intake duct in the direction of gravity and in the reservoir is introduced into the intake passage downstream of the intake throttle valve in the air flow direction via the bypass flow path, and combustion of the internal combustion engine When sucking into the chamber, the flow rate of the fluid flowing through the bypass channel (fluid obtained by mixing air with the liquid accumulated in the reservoir) is adjusted by controlling the flow rate control valve installed in the bypass channel.
Accordingly, it is possible to appropriately control the amount of liquid sucked up in the lowermost part of the intake duct in the gravity direction and the storage part. Therefore, an appropriate amount of liquid discharged from the intake duct to the combustion chamber of the internal combustion engine can be stably controlled for a long period of time so as not to hinder the internal combustion engine.

According to the second aspect of the present invention, the liquid discharge means is provided with the communication portion that connects the lowermost portion of the intake duct in the gravitational direction and the storage portion. In this case, the liquid discharged from the lowest part in the gravity direction of the intake duct is discharged to the storage part via the communication part, and the liquid discharged to the storage part is (temporarily) stored in the storage part.
According to the third aspect of the present invention, the communication portion constitutes a communication pipe having a flow path that connects the gravity direction lowermost portion of the intake duct and the storage portion.
The liquid discharge means is provided with a flow path opening / closing valve (first control valve) for opening and closing the flow path. As the channel opening / closing valve, for example, an electromagnetic channel opening / closing valve may be employed.
Here, for example, when the operation of the internal combustion engine is stopped, the flow path opening / closing valve is opened to open the flow path, whereby the liquid accumulated in the lowermost part of the intake duct in the gravity direction is stored via the flow path in the communication pipe. Drain to the side.
Further, for example, when the internal combustion engine is operated (operated), the flow path opening / closing valve is closed to close the flow path, so that the intake passage on the downstream side of the liquid in the bypass flow path in the air flow direction from the intake throttle valve This prevents the liquid from flowing back to the lowermost part of the intake duct in the direction of gravity or the storage part side.

According to invention of Claim 4, a bypass flow path is formed in the 1st flow path formed in the upstream of a fluid flow direction rather than a storage part, and the downstream of a fluid flow direction from a storage part. A second flow path is provided.
The first flow path is formed, for example, so as to branch from an intake passage on the upstream side in the air flow direction with respect to the intake throttle valve. The first flow path is a fluid flow path for guiding the fluid that has flowed from the intake passage upstream of the intake throttle valve in the air flow direction to the storage portion.
The second flow path is formed, for example, so as to join the intake passage on the downstream side in the air flow direction with respect to the intake throttle valve. The second flow path is a fluid flow path for guiding the mixed fluid obtained by mixing the fluid stored in the storage portion to the intake passage on the downstream side in the air flow direction from the intake throttle valve.

According to the fifth aspect of the present invention, the flow rate for controlling the flow rate of the mixed fluid obtained by changing the opening area of the first flow path of the bypass flow path and mixing the fluid with the liquid accumulated in the storage section in the liquid discharge means. A control valve (second control valve) is employed. For example, an electromagnetic flow control valve may be employed as the flow control valve.
Further, the pressure difference between the intake passage upstream of the intake throttle valve in the air flow direction and the intake passage downstream of the intake throttle valve in the air flow direction, that is, the pressure difference between the upstream and downstream of the intake throttle valve (intake throttle valve By using the intake negative pressure generated in the intake passage on the downstream side of the air flow direction with respect to the intake throttle valve, the liquid accumulated in the lowermost part of the intake duct in the gravity direction and the storage part passes through the bypass flow path. When the air flow is introduced into the intake passage downstream of the intake throttle valve and sucked into the combustion chamber of the internal combustion engine, the flow control valve installed in the bypass passage is controlled (for example, the flow control valve is opened). (The first passage opening area of the bypass passage) is controlled so that a large amount of liquid does not flow into the combustion chamber of the internal combustion engine at a time. The flow rate of the mixed fluid (air mixed) is adjusted. It is.
Accordingly, it is possible to appropriately control the amount of liquid sucked up in the lowermost part of the intake duct in the gravity direction and the storage part. Therefore, an appropriate amount of liquid discharged from the intake duct to the combustion chamber of the internal combustion engine can be stably controlled for a long period of time so as not to hinder the internal combustion engine.

Also, in the intake (duct) structure configured such that the lowermost gravitational direction of the intake duct is positioned upstream of the intake throttle valve in the airflow direction, the lower gravitational direction of the intake duct and the gravitational direction than the reservoir By installing a flow control valve in the first flow path of the bypass flow path so as to be located above, the liquid accumulated in the lowermost part of the intake duct in the gravitational direction and in the storage section is removed from the intake throttle valve via the bypass flow path. Even when it is introduced into the intake passage on the downstream side in the air flow direction and discharged into the combustion chamber of the internal combustion engine, it is possible to prevent liquid from passing through the flow control valve installed in the bypass flow path. .
This makes it difficult for sticky substances such as deposits to adhere to the valve body (valve) of the flow control valve, so that the accuracy of the operation response of the flow control valve can be ensured for a long time. Therefore, an appropriate amount of liquid discharged from the intake duct to the combustion chamber of the internal combustion engine can be stably controlled for a long period of time so as not to hinder the internal combustion engine.

According to the sixth aspect of the present invention, the liquid discharge means is provided with the flow path opening / closing valve (third control valve) for opening and closing the second flow path of the bypass flow path. As the channel opening / closing valve, for example, an electromagnetic channel opening / closing valve may be employed.
This flow path opening / closing valve is set as required. For example, when it is desired to eliminate the influence of the bypass flow path during normal operation (operation) of the internal combustion engine, or from the intake passage downstream of the intake throttle valve in the air flow direction to the second flow path due to the supercharging pressure of the supercharger. It is set when it is desired to prevent the intake air from entering and the liquid in the bypass flow path from being pushed out by the intake air to contaminate the flow control valve installed in the first flow path of the bypass flow path.

According to the seventh aspect of the present invention, the introduction port provided at the upstream end in the fluid flow direction of the first flow path of the bypass flow path opens in the intake passage on the upstream side in the air flow direction from the intake throttle valve. ing. According to the eighth aspect of the present invention, the outlet port provided at the downstream end in the fluid flow direction of the second flow path of the bypass flow path opens in the intake passage on the downstream side in the air flow direction from the intake throttle valve. ing. According to the ninth aspect of the present invention, the intercooler having the core that cools the intake air compressed by the supercharger by exchanging heat with the cooling medium is provided.
According to invention of Claim 10, the cooler case which accommodates a core is provided in the intercooler. The cooler case of the intercooler has a bottom portion where a liquid obtained by liquefying oil mist or condensed water is accumulated. The bottom of the cooler case constitutes the lowest part of the intake duct in the direction of gravity.

According to the ninth and tenth aspects of the present invention, the liquid accumulated (accumulated) at the bottom of the cooler case is aired more than the communication unit, the bypass channel (storage unit, second channel), and the intake throttle valve. An intake passage on the downstream side in the flow direction and a liquid discharge path for discharging to the combustion chamber of the internal combustion engine are formed.
When the flow control valve is opened, the fluid flowing into the first flow path from the upstream intake passage in the air flow direction from the intake throttle valve pushes the liquid discharged from the bottom of the intercooler cooler case to the storage section. However, it is introduced into the intake passage downstream of the intake throttle valve in the air flow direction through the second flow path while being mixed. As a result, the liquid accumulated in the lowermost part of the intake duct in the gravitational direction and in the reservoir is introduced into the intake passage downstream of the intake throttle valve in the air flow direction via the bypass flow path and discharged into the combustion chamber of the internal combustion engine. can do. Therefore, the internal combustion engine and the intercooler can be kept in a good state without continuously storing a large amount of liquid in the cooler case of the intercooler. For example, corrosion of the intercooler can be suppressed.

According to an eleventh aspect of the present invention, an intercooler having a cooler case that houses a core, a throttle device having a throttle body that houses an intake throttle valve, a cooler case of the intercooler, and a throttle body of the throttle device are provided. And an air connector that communicates.
The air connector has a bottom portion where a liquid obtained by liquefying oil mist or condensed water is accumulated. The bottom of this air connector constitutes the lowest part of the intake duct in the direction of gravity.
As a result, the liquid accumulated (accumulated) at the bottom of the air connector passes through the communication part and the bypass flow path (reservoir part, second flow path) and is located downstream of the intake throttle valve in the air flow direction. After being introduced into the intake passage, a liquid discharge path for discharging into the combustion chamber of the internal combustion engine is formed.
When the flow control valve is opened, the fluid flowing into the first flow path from the intake passage on the upstream side in the air flow direction from the intake throttle valve pushes out the liquid discharged from the bottom of the air connector to the reservoir, and The air is mixed and introduced into the intake passage downstream of the intake throttle valve in the air flow direction through the second flow path. As a result, the liquid accumulated in the lowermost part of the intake duct in the gravitational direction and in the reservoir is introduced into the intake passage downstream of the intake throttle valve in the air flow direction via the bypass flow path and discharged into the combustion chamber of the internal combustion engine. can do. Therefore, the internal combustion engine and the intercooler can be kept in a good state without continuously storing a large amount of liquid in the cooler case of the intercooler. For example, corrosion of the intercooler can be suppressed.

According to the twelfth aspect of the present invention, the introduction port provided at the upstream end of the bypass flow path in the fluid flow direction opens at the intake passage on the upstream side in the air flow direction from the core of the intercooler.
According to the thirteenth aspect of the present invention, the introduction port provided at the upstream end of the bypass flow path in the fluid flow direction opens at the intake passage on the downstream side in the air flow direction from the core of the intercooler.
Note that the liquid introduction port (the drain port of the cooler case) in the communication portion may be configured to open in the intake passage on the downstream side in the air flow direction from the core of the intercooler.
In these cases, there is no concern of being exposed to high temperatures due to the supercharging pressure of the supercharger, considering the heat damage of the flow rate control valve such as the bypass valve and the flow path opening / closing valve such as the drain valve. Therefore, by connecting a bypass flow path (the first flow path) or a communication portion downstream of the intercooler core in the air flow direction, a flow rate control valve such as a bypass valve or a flow path opening / closing valve such as a drain valve. Reliability can be improved.

FIG. 1 is a schematic diagram showing an engine control system (a structure for sucking up oil accumulated in an intake duct of an engine) (Example 1). (Example 2) which showed the engine control system (The suction structure of the oil accumulate | stored in the intake duct of an engine). FIG. 9 is a schematic diagram showing an engine control system (a structure for sucking up oil accumulated in an intake duct of an engine) (Example 3).

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
The purpose of the present invention is to keep the internal combustion engine and the intake duct in a good state without continuously storing a large amount of liquid in the intake duct. By using the pressure difference (intake negative pressure) upstream and downstream of the valve, it is introduced into the intake passage downstream of the intake throttle valve in the air flow direction via the bypass flow path and sucked into the combustion chamber of the internal combustion engine It was realized.
The purpose of ensuring the long-term accuracy of the responsiveness of the flow control valve is to allow the liquid accumulated in the lowermost part of the intake duct in the direction of gravity and in the reservoir to flow more air than the intake throttle valve via the bypass channel. This is realized by preventing the liquid from passing through the flow control valve even when it is introduced into the intake passage on the downstream side in the direction and discharged into the combustion chamber of the internal combustion engine.
Furthermore, the liquid collected in the lowermost part of the intake duct in the gravitational direction and in the reservoir is used to control the amount of liquid discharged from the intake duct into the combustion chamber of the internal combustion engine so that the internal combustion engine is not hindered. The valve opening degree of the flow control valve installed in the bypass flow path is introduced into the intake passage downstream of the intake throttle valve in the air flow direction via the bypass flow path and sucked into the combustion chamber of the internal combustion engine. This was achieved by controlling so that a large amount of liquid did not flow into the combustion chamber of the internal combustion engine at once.

[Configuration of Example 1]
FIG. 1 shows a first embodiment of the present invention, and FIG. 1 shows an engine control system (a structure for sucking up oil accumulated in an intake duct of an engine).

  The control device (engine control system) for the internal combustion engine of the present embodiment uses a pressure of exhaust gas (exhaust gas) of the internal combustion engine (engine E) to supercharge (compress) the intake air that has passed through the air cleaner 1. An exhaust gas recirculation device (EGR system) that recirculates (recirculates) EGR gas, which is part of the exhaust gas of engine E, from the exhaust passage to the intake passage; An electronic throttle device that adjusts the flow rate of intake air (intake air) supplied to the combustion chamber of each cylinder of the engine E, and a blow-by gas reduction device that re-combusts the blow-by gas filled in the crankcase of the engine E; An oil discharge mechanism for discharging the liquid accumulated in the intake duct of the engine E into the combustion chamber of each cylinder of the engine E, and the fuel for each cylinder of the engine E And is used as an intake control system for an internal combustion engine for controlling the intake air (intake) to the chamber (intake device for an internal combustion engine).

The engine E of the present embodiment employs a multi-cylinder diesel engine (in-line 4-cylinder engine) having a plurality of cylinders (cylinder bores). However, the present invention is not limited to a multi-cylinder diesel engine, and a multi-cylinder gasoline engine may be applied.
The engine E is installed together with a turbocharger and an EGR system in an engine room of a vehicle such as an automobile. Each cylinder (cylinder head) of the engine E is equipped with an injector for injecting and supplying fuel into the combustion chamber of each cylinder.
The engine E has an intake pipe (intake duct) that forms an intake passage through which intake air sucked into the combustion chamber of each cylinder flows, and an exhaust passage for exhausting exhaust gas flowing out of the combustion chamber of each cylinder to the outside. And an exhaust pipe (exhaust duct) to be formed.

The intake duct includes an air cleaner 1, a turbocharger compressor, an intercooler (cooler core 2, cooler case 3, cooler cover 4), an air connector 5, an electronic throttle device (throttle body 6, throttle valve 7, actuator), and an intake manifold. 9 etc. are installed. The intake manifold 9 is connected to an intake port for each cylinder of the engine E.
The exhaust duct is provided with an exhaust manifold, a turbocharger turbine, an exhaust purification device (catalyst 10), an exhaust throttle valve, a muffler, and the like. The exhaust manifold is connected to an exhaust port for each cylinder of the engine E.

Here, the oil discharge mechanism includes a drain pipe 11 that discharges (drains) liquid (hereinafter referred to as oil) in which oil mist, condensed water, and the like are liquefied from the bottom of the cooler case 3 that is the lowest part of the intake duct in the gravitational direction. And a bypass pipe 12 and the like for collecting oil discharged from the bottom of the cooler case 3 through the drain pipe 11.
The drain pipe 11 is provided with a drain valve 13 that is an electromagnetic channel opening / closing valve.
The bypass pipe 12 is provided with a bypass valve 14 that is an electromagnetic flow control valve and a through valve 15 that is an electromagnetic flow path opening / closing valve.
The drain valve 13, the bypass valve 14, and the through valve 15 are batteries mounted on a vehicle such as an automobile through a valve drive circuit that is electronically controlled by an engine control unit (electronic control unit: hereinafter referred to as ECU) 16. Is electrically connected.
Details of the oil discharge mechanism will be described later.

Here, the intake device of the internal combustion engine includes an intercooler that cools the intake air that has passed through the compressor of the turbocharger (supercharger). The intercooler includes a cooler core 2, a cooler case 3, a cooler cover 4, and the like.
The cooler core 2 is composed of a plurality of flat tubes that cool the intake air that has been compressed by a turbocharger compressor and heated to a high temperature by exchanging heat with cooling water that is a cooling medium. The cooler case 3 stores the cooler core 2 in a core storage space formed between the cooler case 4 and the cooler cover 4.
Details of the intercooler will be described later.

Here, the electronic throttle device is rotatably accommodated in a throttle body 6 connected to an outlet end portion of the cooler case 3 via a cylindrical air connector 5 and in the throttle body 6 (throttle bore). The throttle valve 7 is provided. This electronic throttle device is an air flow rate adjusting device that adjusts the flow rate of intake air by opening and closing the throttle valve 7.
As an actuator that drives the throttle valve 7, an electric actuator that rotationally drives a shaft that is a rotation shaft of the throttle valve 7 by using a driving force of an electric motor is employed.
The actuator includes an electric motor that generates power for driving the throttle valve 7 when supplied with electric power, and a speed reduction mechanism that reduces the rotation of the electric motor and transmits it to the shaft.
The electric motor is electrically connected to a battery mounted on a vehicle such as an automobile via a motor drive circuit electronically controlled by the ECU 16.

The turbocharger includes a compressor provided in the middle of the intake duct of the engine E, and a turbine provided in the middle of the exhaust duct of the engine E, and compresses the intake air flowing through the intake duct by the compressor. This is a turbocharger that sends (intake air) into the combustion chamber of each cylinder of the engine E.
In the turbocharger, when a turbine wheel (turbine wheel 17) is rotationally driven by exhaust gas, a turbine shaft 18 connected to the turbine wheel 17 and a compressor impeller (compressor impeller 19) also rotate, and the compressor impeller 19 is rotated. Compress the intake air.

The turbine includes a turbine wheel 17 and a turbine housing. The turbine wheel 17 has a plurality of turbine blades (blades) in the circumferential direction, and is rotationally driven by the exhaust pressure of the engine E. The turbine wheel 17 is directly connected to the compressor impeller 19 of the compressor via the turbine shaft 18 to rotationally drive (directly drive) the compressor impeller 19.
A wheel housing space for rotatably housing the turbine wheel 17 is formed at the center of the turbine housing.
The turbine housing has a bypass flow path (waste gate flow) for guiding exhaust gas flowing into the turbine inlet flow path from the junction of the exhaust manifold to the turbine outlet flow path, bypassing the wheel housing space (turbine wheel 17). Road) 21 is formed.
In addition, a wastegate valve 22 that controls the flow rate of the exhaust gas flowing through the wastegate passage 21 by an opening / closing operation is mounted on the turbine housing.

The compressor includes a compressor impeller 19 and a compressor housing. The compressor impeller 19 has a plurality of impeller blades (blades) in the circumferential direction, and is connected to a turbine wheel 17 via a turbine shaft 18 to be rotationally driven (directly connected).
An impeller accommodating space for rotatably accommodating the compressor impeller 19 is formed at the center of the compressor housing.
The compressor housing has a bypass passage 23 for guiding the intake air or EGR gas flowing into the compressor inlet passage from the air cleaner 1 or the EGR system to the impeller housing space (compressor impeller 19) and leading to the compressor outlet passage. Is formed.
The compressor housing is provided with a bypass valve 24 for controlling the flow rate of intake air or EGR gas flowing through the bypass passage 23 by an opening / closing operation.

The engine body (cylinder block and cylinder head) of the engine E is formed with an intake port that is opened and closed by an intake valve and an exhaust port that is opened and closed by an exhaust valve.
In each cylinder 25 of the engine E, for example, in a four-cylinder engine, four combustion chambers (cylinder bores) are formed in the cylinder arrangement direction. A piston 26 connected to the crankshaft is supported in each cylinder bore through a connecting rod so as to be slidable in the reciprocating sliding direction.

The exhaust duct downstream of the turbocharger turbine or exhaust purification device (catalyst 10) and the intake duct upstream of the turbocharger compressor recirculate (reflux) the EGR gas from the exhaust passage to the intake passage. Are connected by an exhaust gas recirculation pipe (EGR gas pipe) forming an exhaust gas recirculation path (EGR gas flow path 31).
The upstream end of the EGR gas pipe is connected to the EGR gas branching portion of the exhaust duct, and the downstream end is connected to the EGR gas merging portion of the intake duct.
The EGR gas pipe includes an EGR gas flow rate control valve (exhaust gas control valve) for controlling the flow rate of the EGR gas flowing through the EGR gas flow path 31 by an opening and closing operation, and EGR that cools the EGR gas by exchanging heat with cooling water. A cooler 32 is installed.
Note that, as described above, an EGR system in which an outlet for EGR gas from the exhaust passage is on the downstream side of the turbine of the turbocharger is referred to as a “low pressure loop (LPL) EGR system”.

In addition, as an actuator for driving the EGR valve 33 that is a valve body (valve element) of the EGR gas flow control valve, an electric actuator that rotationally drives the shaft 34 that is the rotating shaft of the EGR valve 33 by using the driving force of the electric motor. 35 is adopted.
The electric actuator 35 includes an electric motor that generates power for driving the EGR valve 33 when supplied with electric power, and a speed reduction mechanism that decelerates the rotation of the electric motor and transmits it to the shaft 34 of the EGR valve 33. .
The electric motor is electrically connected to a battery mounted on a vehicle such as an automobile via a motor drive circuit electronically controlled by the ECU 16.

Here, in the valve body of the exhaust throttle valve, a valve 36 which is a valve body (valve element) capable of controlling the amount of EGR gas flowing into the EGR gas flow path 31 from the exhaust passage is accommodated. As an actuator for driving the valve 36, an electric actuator 37 is used that rotationally drives a shaft, which is a rotating shaft of the valve 36, using a driving force of an electric motor. The electric actuator 37 includes an electric motor that generates power for driving the valve 36 when supplied with electric power, and a speed reduction mechanism that reduces the rotation of the electric motor and transmits it to the shaft of the valve 36.
The electric motor is electrically connected to a battery mounted on a vehicle such as an automobile via a motor drive circuit electronically controlled by the ECU 16.

  The blow-by gas reduction device extracts blow-by gas (PCV gas) that blows into the crankcase from the gap between the cylinder 25 and the piston 26 of the engine E, and returns it to the intake duct (for example, a surge tank or an intake manifold) of the engine E. The engine E is sucked into the combustion chamber of each cylinder and recombusted in the combustion chamber of each cylinder, and clean outside air filtered by the air cleaner 1 (clean air from which impurities contained in the outside air have been removed) is cranked. It is a PCV device that is introduced into the case (crank chamber) and ventilates the inside of the crankcase.

The blow-by gas reduction device includes a new introduction hose (PCV hose) that connects the inside of the engine E, particularly the inside of the crankcase (crank chamber) and the air cleaner hose, the inside of the engine E, particularly the inside of the cylinder head cover, and the surge tank or A blow-by gas recirculation hose connecting the inside of the intake manifold 9 is provided.
The air cleaner hose connects the outlet end portion of the air cleaner 1 and the intake port of the EGR gas merging portion of the intake duct.

Inside the PCV hose, a new introduction passage (ventilation passage) for guiding clean outside air (clean air) filtered by the air cleaner 1 to the inside of the engine E, particularly the inside of the crankcase (crank chamber) is formed. Yes.
Inside the blow-by gas recirculation hose, a blow-by gas recirculation passage for returning the blow-by gas inside the crankcase of the engine E (crank chamber) to the intake duct (for example, a surge tank or the intake manifold 9) of the engine E is formed. Yes.
A PCV valve that is opened and closed according to the operating state of the engine E is installed in the blow-by gas recirculation passage.

Here, the intake manifold 9 is composed of a plurality of parts (divided molded bodies). The plurality of parts are all made of synthetic resin.
The intake manifold 9 includes a surge tank 41 that reduces pressure fluctuations of the intake air flowing in from the throttle body 6, and a plurality (for each cylinder) of intake branch pipes that are connected to a plurality (for each cylinder) of air outlets of the surge tank 41. 42, a surge tank integrated intake manifold having an oil distribution pipe 43 and the like for distributing and supplying oil to a plurality of intake branch pipes 42;

The surge tank 41 temporarily stores intake air and forms a surge tank chamber 44 for distributing and supplying intake air to a plurality of intake branch pipes 42 connected to combustion chambers and intake ports for each cylinder of the engine E. The main body and an intake introduction pipe (throttle connection pipe) for introducing intake air from the throttle body 6 to the surge tank main body are provided.
The upstream end of the intake pipe is airtightly connected to the downstream end of the throttle body 6 via an air connector 5. A communication channel through which intake air is introduced from the throttle body 6 is formed in the intake pipe.
In the surge tank 41 of this embodiment, a gas introduction chamber is formed adjacent to the surge tank chamber 44. A gas introduction pipe (not shown) such as blow-by gas or fuel evaporative gas is connected to the gas introduction chamber.
A cooler mounting seat (not shown) for connecting the cooler case 3 of the intercooler is integrally formed on the surge tank 41 of the intake manifold 9.

The plurality of intake branch pipes 42 are independently connected to the combustion chamber and the intake port for each cylinder of the engine E, and branch from the surge tank chamber 44 of the surge tank 41. Inside each intake branch pipe 42, an intake branch flow path 45 is formed for guiding intake air from the surge tank chamber 44 to the intake port for each cylinder of the engine E.
The oil distribution pipe 43 is integrally formed above the intake branch pipes 42 in the gravity direction at the uppermost part in the gravity direction of the intake manifold 9.
Inside the oil distribution pipe 43, a tournament branch-shaped oil distribution passage is formed. An oil introduction pipe (not shown) connected to the oil discharge mechanism is provided upstream of the oil distribution pipe 43. In addition, the downstream end part of the bypass pipe 12 into which oil is introduced from the oil discharge mechanism is connected to the oil introduction pipe.

[Features of Example 1]
Next, details of the intake duct, the intercooler, and the oil discharge mechanism of this embodiment will be briefly described with reference to FIG.

The internal combustion engine (engine E) of the present embodiment includes an intake duct structure formed such that the lowermost portion of the intake duct in the gravitational direction is positioned upstream of the throttle valve 7 in the intake flow direction.
The intake duct of the present embodiment is composed of an air cleaner case of the air cleaner 1, a compressor housing of a turbocharger, an intercooler cooler case 3, a cooler cover 4, an air connector 5, an electronic throttle device throttle body 6 and an intake manifold 9. ing.
Inside the intake duct, an intake passage through which intake air sucked into the combustion chamber of each cylinder of the engine E flows is formed.

Here, the intercooler is an air cooler that cools compressed air (intake air) that has been compressed by the compressor impeller 19 of the turbocharger to become high pressure and the intake air temperature has risen. The intercooler is a water-cooled heat exchanger that cools the intake air by exchanging heat between the coolant flowing in from the water jacket of the engine E and the intake air compressed by the compressor impeller 19. The intercooler includes a laminated cooler core 2 configured by laminating a plurality of flat tubes in which an intake passage is formed in the thickness direction thereof, a cooler case 3 into which intake air compressed by the compressor impeller 19 flows, And the cooler cover 4 etc. which block | close the opening part of this cooler case 3 are comprised.
The cooler core 2 has a plurality of cooling water passages (not shown) through which the cooling water circulates so as to go around the plurality of flat tubes.

The cooler case 3 is formed in a bottomed cylindrical shape and is integrally formed with the cooler mounting seat of the intake manifold 9. A bottom portion 51 that forms an oil pan in which oil, which is a liquid obtained by liquefying oil mist or condensed water, is provided at the lowermost portion in the gravity direction of the cooler case 3. And the bottom part 51 of the cooler case 3 comprises the gravity direction lowermost part of an intake duct.
A drain port 52 opened at the bottom of the cooler case 3 in the direction of gravity is formed at the bottom 51 of the cooler case 3. The drain port 52 is located downstream of the cooler core 2 in the intake air flow direction and below the intake air introduction port of the cooler case 3 in the gravity direction.

The cooler case 3 includes an intake air introduction pipe 54 that introduces intake air from the outside (intake pipe connected to the compressor housing) to the inside of the cooler core 2, a case main body 56 that forms a core storage space therein, and an internal ( It has an intake lead-out pipe or the like for leading intake air from the core storage space) to the outside (air connector 5).
A coupling portion coupled to the intake pipe is integrally provided at an upstream end portion of the intake air introduction pipe 54. A cooler inlet channel 57 for introducing intake air from the compressor housing to the core storage space is formed in the intake air introduction pipe 54 via an intake air introduction port connected to the outlet end of the intake pipe.
A coupling portion for coupling the air connector 5 is integrally provided at the downstream end portion of the intake lead-out pipe. A cooler outlet channel 58 for leading the intake air from the core housing space to the throttle body 6 through the air connector 5 is formed inside the intake lead pipe.

  The case body 56 is provided between the downstream end portion of the intake intake pipe 54 and the upstream end portion of the intake lead-out pipe. A space upstream of the cooler core 2 in the intake flow direction in the case body 56 constitutes an inlet tank 56a that communicates with inlet portions of a plurality of flat tubes. Further, in the inside of the case main body 56, the space on the downstream side of the cooler core 2 in the intake flow direction constitutes an outlet tank 56b communicating with the outlet portions of the plurality of flat tubes. Thereby, the cooler core 2 is provided between a pair of inlet and outlet tanks 56a and 56b. Further, the upper part of the case main body 56 is opened in the gravity direction, and the upper opening is hermetically closed by the cooler cover 4.

The cooler cover 4 is formed with a cooling water inlet and a cooling water outlet. And the cooling water inflow port of the cooler cover 4 is connected to a cooling water introduction pipe (not shown) for flowing cooling water into the plurality of cooling water flow paths. Further, a cooling water outlet pipe (not shown) is connected to the cooling water outlet of the cooler cover 4 for allowing the cooling water to flow out from the plurality of cooling water flow paths.
When the case main body 56 is not provided with an upper opening, the cooler cover 4 may be omitted.

The air connector 5 is a cylindrical intake duct that forms an intake passage 59 that communicates the downstream end of the intake lead-out pipe of the cooler case 3 of the intercooler and the upstream end of the throttle body 6 of the electronic throttle device.
In this embodiment, the bottom 51 constituting the lowermost gravitational direction of the intake duct is provided at the lowermost gravitational direction of the case main body 56 and the intake lead-out pipe of the cooler case 3. You may provide in the lower part the bottom part (bottom part of the air connector 5) which comprises the gravity direction lowest part of an intake duct.
Further, when the upstream end of the air connector 5 is directly connected to the outlet of the case body 56 of the cooler case 3, the intake duct is placed at the lowermost part in the gravity direction of the case body 56 and the air connector 5 of the cooler case 3. Is provided with a bottom 51 constituting the lowest part in the direction of gravity.

Here, the intake duct includes first and second intake passages 61 and 62 connected in series in the flow direction (intake flow direction) of intake air flowing from the air cleaner 1 to each cylinder of the engine E and the combustion chamber. I have. The two first and second intake passages 61 and 62 are connected to a relay intake passage (an intake passage 63 in the air connector 5 and a throttle bore (intake passage) 64 in the throttle body 6) formed between them. Are in communication with each other.
The first intake passage 61 is formed on the upstream side in the intake flow direction with respect to the throttle valve 7 that is housed in the throttle bore 64 so as to be rotatable (openable and closable).
The second intake passage 62 is formed downstream of the throttle valve 7 in the intake flow direction.

Next, the details of the oil discharge mechanism of the present embodiment will be briefly described with reference to FIG.
The oil discharge mechanism includes a drain pipe 11, a bypass pipe 12, a drain valve 13, a bypass valve 14 and a through valve 15.
The drain pipe 11 is a communication part (communication pipe) that communicates the bottom 51 of the cooler case 3 of the intercooler and the oil storage part 65 of the bypass pipe 12. The drain pipe 11 extends straight from the outer surface of the bottom portion 51 of the cooler case 3 to the lower side in the gravity direction than the bottom portion 51 of the cooler case 3. A drain channel (communication channel, discharge channel) 66 for draining oil from the bottom 51 of the cooler case 3 to the oil reservoir 65 of the bypass pipe 12 is formed inside the drain pipe 11.
The drain port 52 of the cooler case 3, which is an oil (liquid) introduction port of the drain pipe 11, is downstream of the intercooler cooler core 2 in the intake air flow direction, that is, the outlet tank 56 b of the case main body 56 of the cooler case 3. It is open at.

The bypass pipe 12 is drained (discharged) via the drain pipe 11 from the bottom 51 of the cooler case 3 located at the lowest gravity direction of the intake duct and the drain port 52 opened at the lowest gravity direction of the cooler case 3. An oil reservoir 65 for temporarily storing oil is provided. Inside the bypass pipe 12, the clean air that has passed through the air cleaner 1 passes through the oil reservoir 65 from the intake passage (first intake passage 61) upstream of the throttle valve 7 in the intake flow direction. A bypass flow path is formed for leading to the intake passage (second intake passage 62) on the downstream side in the intake flow direction with respect to 7.
The oil storage part 65 has a connection part with the drain pipe 11. A connection portion (communication port 67) that communicates with the drain flow path 66 in the drain pipe 11 is opened at the connection portion of the oil storage portion 65.

The bypass pipe 12 has a first pipe on the left side (upstream side in the air flow direction) of the oil reservoir 65 and a right side (downstream side of the air flow direction) of the oil reservoir 65. A second pipe is provided. In addition, the connection part of the oil storage part 65 is an intermediate part located in the middle of the two first and second pipes constituting the bypass pipe 12.
The first pipe is bent at a right angle on the way. A first flow path 71 into which clean clean air (air) that has passed through the air cleaner 1 is introduced (supplied) from the outside (the first intake passage 61 of the intake duct) is formed inside the first pipe. .
The second pipe is bent at a right angle in the middle. Inside the second pipe, a second flow path 72 formed downstream of the oil reservoir 65 in the air flow direction is formed.
Therefore, the bypass flow path includes the first flow path 71, the oil reservoir 65, and the second flow path 72.

The first flow path 71 is formed so that clean air branches off from the first intake passage 61. The first flow channel 71 is an upstream flow channel formed on the upstream side in the air flow direction with respect to the oil reservoir 65.
An upstream end of the first flow path 71 is provided with a cooler inlet flow path 57 of the intake air introduction pipe 54 of the cooler case 3, that is, an introduction port (first port) 73 opened in the first intake passage 61. The introduction port 73 opens in the first intake passage 61 on the upstream side in the intake flow direction with respect to the cooler core 2 of the intercooler. The introduction port 73 is opened above the bottom 51 of the cooler case 3 and the oil reservoir 65 of the bypass pipe 12 in the direction of gravity (communication with the cooler inlet passage 57 in the first intake passage 61), that is, The first intake passage 61 is provided so as to branch from the cooler inlet passage 57.

The second flow path 72 is an oil outlet flow path that guides the mixed fluid obtained by mixing clean air to the oil stored in the oil storage section 65 to the second intake passage 62. The second flow path 72 is formed so that the mixed fluid merges with the second intake passage 62. The second flow path 72 is a downstream flow path formed downstream of the oil reservoir 65 in the fluid flow direction.
An oil outlet port (second port) 74 opened in the intake branch passage 45 of the intake manifold 9, that is, the intake branch passage 45 of the second intake passage 62, is provided at the downstream end of the second passage 72. It has been.
The oil outlet port 74 is opened above the bottom 51 of the cooler case 3 and the oil reservoir 65 of the bypass pipe 12 in the gravitational direction (communication with the intake branch passage 45 in the second intake passage 62), that is, The second intake passage 62 is provided so as to join the intake branch passage 45.

The drain valve 13 is a normally open electromagnetic flow path opening / closing valve (vacuum switching valve: VSV) that opens and closes a drain flow path 66 formed in the drain pipe 11. The drain valve 13 includes a valve body (valve) that opens and closes the drain passage 66, a valve seat on which the valve can be seated, a spring that presses the valve against the valve seat, and an electromagnetic actuator that separates the valve from the valve seat. Yes.
In the valve seat, a valve hole that constitutes a part of the drain channel 66 is formed.
The electromagnetic actuator includes a solenoid having a coil that generates a magnetic force when energized.
When the solenoid coil is energized (turned on), the valve that is the valve body of the drain valve 13 sits on the valve seat and closes (fully closes) the valve hole (drain flow path 66). Further, when the energization of the solenoid coil is stopped (off), the drain valve 13 is separated from the valve seat to open (fully open) the valve hole (drain channel 66).

The bypass valve 14 is a flow rate control valve that controls the flow rate of the mixed fluid that flows through the oil reservoir 65 and the first and second flow paths 71 and 72 formed in the bypass pipe 12, and the oil reservoir of the bypass pipe 12. The fluid mixture containing oil is introduced (oil purge) from 65 to the downstream side (second intake passage 62) of the throttle valve 7 via the second flow path 72 and discharged to the combustion chamber of each cylinder of the engine E. This is a normally open type electromagnetic flow control valve (solenoid valve, oil purge duty VSV).
The bypass valve 14 is installed on the introduction port 73 side of the first flow path 71 of the bypass pipe 12 so as to be positioned above the bottom 51 of the cooler case 3 and the oil storage portion 65 of the bypass pipe 12 in the gravity direction. Yes.

The bypass valve 14 includes a valve body (valve) that opens and closes the first flow path 71, a valve seat on which the valve can be seated, a spring that presses the valve against the valve seat, and an electromagnetic actuator that separates the valve from the valve seat. Yes.
A valve hole that forms a part of the first flow path 71 is formed in the valve seat.
The electromagnetic actuator includes a solenoid having a coil that generates a magnetic force when energized.
When the energization of the solenoid coil is stopped (turned off), the valve that is the valve body of the bypass valve 14 is detached from the valve seat and opens (fully opens) the valve hole (first flow path 71).
Here, the bypass valve 14 controls the oil purge flow rate for introducing the mixed fluid containing oil from the oil reservoir 65 of the bypass pipe 12 to the second intake passage 62 by controlling the time for energizing the solenoid coil. ing. By controlling the amount of power supplied to the solenoid coil of the bypass valve 14 (voltage value or current value), the flow area of the first flow path 71 is changed to control the oil purge flow rate. Also good.

The through valve 15 is a normally open electromagnetic flow path opening / closing valve (vacuum switching valve: VSV) that opens and closes the second flow path 72 formed in the bypass pipe 12. The through valve 15 includes a valve body (valve) that opens and closes the second flow path 72, a valve seat on which the valve can be seated, a spring that presses the valve against the valve seat, and an electromagnetic actuator that separates the valve from the valve seat. ing.
A valve hole that constitutes a part of the second flow path 72 is formed in the valve seat.
The electromagnetic actuator includes a solenoid having a coil that generates a magnetic force when energized.
When the solenoid coil is energized (turned on), the valve that is the valve body of the through valve 15 sits on the valve seat and closes (fully closes) the valve hole (second flow path 72). Further, when the energization to the solenoid coil is stopped (off), the valve of the through valve 15 is detached from the valve seat and opens (fully opens) the valve hole (second flow path 72).

Here, the drain valve 13, the bypass valve 14, and the through valve 15 are configured to be electronically controlled by the ECU 16 via a valve drive circuit.
The ECU 16 is a microcomputer having a known structure that includes functions such as a CPU that performs control processing and arithmetic processing, a control program or control logic, a storage device (RAM such as RAM and ROM) that stores various data, and a timer. Is provided. The ECU 16 includes various sensors such as an air flow meter, a crank angle sensor, an accelerator opening sensor, a throttle opening sensor, an EGRV sensor, an intake air temperature sensor, a cooling temperature sensor, and an exhaust gas sensor (air-fuel ratio sensor 78, oxygen concentration sensor 79). These sensor output signals are A / D converted by an A / D conversion circuit and then input to a microcomputer.

The microcomputer of the ECU 16 measures (calculates) the throttle opening corresponding to the valve opening of the throttle valve 7 based on the electric signal (throttle opening signal) output from the throttle opening sensor, and calculates the calculated throttle. The opening is used for various engine controls (for example, PCV valve opening control).
Here, the microcomputer of the ECU 16 controls the time during which the coil of the bypass valve 14 is energized (ratio of on time to off time: duty ratio), thereby allowing the fluid mixture containing oil to flow through the oil reservoir of the bypass pipe 12. The oil purge flow rate introduced from 65 into the second intake passage 62 is controlled.

[Control Method of Example 1]
Next, a method for controlling the oil discharge mechanism incorporated in the engine control system of this embodiment will be briefly described with reference to FIG.

First, when the ignition switch is turned on (IG / ON), an air flow meter, a crank angle sensor, an accelerator opening sensor, a throttle opening sensor, an EGRV sensor, an intake air temperature sensor, a cooling temperature sensor, and an exhaust gas sensor (air-fuel ratio sensor 78). Sensor output signals from various sensors such as the oxygen concentration sensor 79) are repeatedly read into the microcomputer of the ECU 16, for example, every predetermined sampling period.
When the ignition switch is turned off (IG / OFF), the microcomputer of the ECU 16 turns off all the coils of the drain valve 13, the bypass valve 14 and the through valve 15 to fully open the drain valve 13 (OPEN The bypass valve 14 is fully opened (OPEN), and the through valve 15 is fully opened (OPEN). As a result, oil can be drained from the bottom 51 of the cooler case 3 to the oil reservoir 65 of the bypass pipe 12 while the engine E is stopped.

  The microcomputer of the ECU 16 does not satisfy a predetermined oil suction condition (whether a predetermined time has elapsed or whether the throttle opening is equal to or less than a predetermined value) during normal operation of the engine E. When the ignition switch is turned on (IG / ON), the drain valve 13 coil, the bypass valve 14 coil, and the through valve 15 coil are all turned on, so that the drain valve 13 is fully closed (CLOSE). The valve 14 is fully closed (CLOSE), and the through valve 15 is fully closed (CLOSE). As a result, during normal operation of the engine E, oil can be contained in the oil reservoir 65 of the bypass pipe 12.

  The microcomputer of the ECU 16 is connected to a drain valve when a predetermined oil suction condition is satisfied during normal operation of the engine E, for example, when a predetermined time has elapsed after the engine is started and the throttle opening is closed to a predetermined value or less. 13 coil is turned ON, the bypass valve 14 coil is duty controlled (DUTY), and the through valve 15 coil is turned OFF, the drain valve 13 is fully closed (CLOSE), and the bypass valve 14 coil is DUTY controlled. Then, the through valve 15 is fully opened (OPEN). As a result, the oil accumulated in the oil reservoir 65 of the bypass pipe 12 is sucked up.

Specifically, the pressure difference between the first intake passage 61 on the upstream side of the throttle valve 7 and the second intake passage 62 on the downstream side of the throttle valve 7, that is, the pressure difference between the upstream and downstream of the throttle valve 7 (intake negative pressure). , The oil accumulated in the bottom 51 of the cooler case 3 and the oil reservoir 65 of the bypass pipe 12 is introduced into the second intake passage 62 via the bypass pipe 12 and is combusted for each cylinder of the engine E. DUTY control is performed on the coil of the bypass valve 14.
At this time, the time for energizing (turning on) the coil of the bypass valve 14 (ratio between the on time and the off time: duty ratio) is, for example, the throttle opening or the storage amount in the oil storage portion 65 of the bypass pipe 12 (for example, the engine Therefore, the oil purge flow rate of the mixed fluid containing oil introduced from the oil reservoir 65 of the bypass pipe 12 to the second intake passage 62 is controlled. The

Thereby, the amount of oil sucked up in the bottom 51 of the cooler case 3 and the oil reservoir 65 of the bypass pipe 12 can be controlled appropriately. Therefore, an appropriate amount of oil discharged from the intake duct to the combustion chamber of each cylinder of the engine E can be stably controlled for a long period of time so that the engine E is not hindered.
For some reason, for example, when a vehicle such as an automobile travels on a slope, the lowermost part of the intake duct is located above the intake port of the engine E in the direction of gravity, and the lubricating oil of the turbocharger, condensed water, etc. If a large amount of oil is sucked into the combustion chamber of the engine E at a time, the combustion state of the engine E deteriorates, white smoke is generated, or emissions are reduced. As described above, By controlling the oil purge flow rate sucked into the combustion chamber of the engine E by an appropriate amount, such a problem can be prevented.

[Operation of Example 1]
Next, the operation of the intake control device for the internal combustion engine of this embodiment will be briefly described with reference to FIG.
The ECU 16 starts the operation of the engine E when the ignition switch is turned on (IG / ON).
Here, when the driver depresses the accelerator pedal, the accelerator opening signal output from the accelerator opening sensor is input to the ECU 16. The ECU 16 supplies power to the actuator (electric motor) 8 so that the throttle valve 7 has a predetermined throttle opening (rotation angle), and the shaft of the electric motor rotates.
Then, when the shaft of the electric motor rotates, torque is transmitted to the shaft of the throttle valve 7. Thereby, the throttle valve 7 is driven in the valve opening operation direction or the valve closing operation direction.
Then, when the specific cylinder of the engine E shifts from the exhaust stroke to the intake stroke where the intake valve is opened and the piston 26 is lowered, the negative pressure (pressure lower than the atmospheric pressure) in the combustion chamber of the cylinder is lowered as the piston 26 is lowered. ) Increases, and intake air is sucked in from the intake port where the intake valve is open.

On the other hand, when the ignition switch is turned on (IG / ON), the ECU 16 first closes the drain valve 13, the bypass valve 14, and the through valve 15 all. Further, the ECU 16 continues the closed state of the drain valve 13 when a predetermined oil suction condition (for example, the throttle valve 7 is closed below a predetermined throttle opening degree) is established during normal operation of the engine E. Then, the valve opening state of the bypass valve 14 is DUTY controlled, and the through valve 15 is opened.
As a result, the intake negative pressure of the engine E passes through the bypass flow path in the bypass pipe 12 and is the first intake passage 61 upstream of the throttle valve 7 in the intake flow direction. Clean air that has reached the introduction port 73 opened by the passage 57 and has passed through the air cleaner 1 is sucked into the bypass flow path (first flow path 71) in the bypass pipe 12 from the introduction port 73.
At this time, the bypass passage in the bypass pipe 12 includes an oil distribution passage or intake branch of the intake manifold 9 that is the second intake passage 62 downstream from the introduction port 73 in the intake flow direction from the introduction port 73. An air flow toward the flow path 45 is generated.

When such an air flow is generated, the oil accumulated in the oil reservoir 65 in the bypass flow path in the bypass pipe 12 is pushed out to the second intake passage 62 side by the clean air that has passed through the air cleaner 1, or The air is mixed with clean air and guided to the second intake passage 62.
Therefore, using the intake negative pressure of the engine E, the oil accumulated in the oil reservoir 65 can be purged to the second intake passage 62 downstream of the throttle valve 7 in the intake flow direction as purge oil.
The purge oil introduced into the second intake passage 62 enters the combustion chamber of the engine E via the oil distribution passage or intake branch passage 45 of the intake manifold 9 and the intake port where the intake valve is open. Inhaled.

[Effect of Example 1]
As described above, the engine E of this embodiment employs an intake duct structure configured such that the bottom 51 of the cooler case 3 that is the lowermost part of the intake duct is positioned upstream of the throttle valve 7. .
Thus, the first intake passage 61 on the upstream side of the throttle valve 7, that is, the outside of the cooler case 3 (compressor housing, air connector 5, throttle body 6), the cooler inlet passage 57 and the cooler outlet passage 58 of the cooler case 3. Or oil generated in the cooler case 3 accumulates at the bottom 51 of the cooler case 3.
In addition, by providing an oil discharge mechanism in the intake duct so as to bypass the throttle valve 7, the oil accumulated (accumulated) in the bottom 51 of the cooler case 3 is drained in the drain pipe 11. 66, an oil discharge path for discharging to the combustion chamber of each cylinder of the engine E is formed via the oil reservoir 65 in the bypass pipe 12, the second flow path 72, and the second intake passage 62 of the intake manifold 9. The

When the throttle valve 7 is closed and the opening area of the bypass valve 14 is changed by DUTY control by the ECU 16, it passes through the air cleaner 1 and is discharged from the compressor of the turbocharger via the junction with the low-pressure loop EGR system. The clean air (or a mixed gas of clean air and EGR gas) opened at the cooler inlet flow path 57 of the cooler case 3, which is the first intake passage 61 upstream of the throttle valve 7 in the intake flow direction. The air is sucked into the bypass flow path (first flow path 71) in the bypass pipe 12 from the introduction port 73.
The air sucked into the first flow path 71 is guided to the bypass flow path (second flow path 72) in the bypass pipe 12 via the bypass flow path (oil storage portion 65) in the bypass pipe 12. It is burned.
At this time, when the air passes through the oil reservoir 65, the air is discharged from the bottom 51 of the cooler case 3 through the drain pipe 11 to the oil reservoir 65, and the oil temporarily stored in the oil reservoir 65 is removed. It is guided to the second flow path 72 while being extruded and mixed with oil.

The mixed fluid obtained by mixing air with the oil guided to the second flow path 72 is the intake manifold 9 that is the second intake passage 62 downstream from the throttle valve 7 in the intake flow direction from the oil outlet port 74. The oil distribution channel or the intake branch channel 45 is introduced.
The mixed fluid introduced into the second intake passage 62 is sucked into the combustion chamber of each cylinder of the engine E by the intake negative pressure.
As a result, the oil accumulated in the bottom 51 of the cooler case 3 and the oil reservoir 65 of the bypass pipe 12 passes through the bypass pipe 12 and the second intake passage 62 of the intake manifold 9, and the combustion chamber for each cylinder of the engine E Can be discharged.

That is, when the throttle valve 7 is closed and the opening area of the bypass valve 14 is changed by DUTY control, the intake negative pressure is introduced from the second intake passage 62 into the bypass passage (second passage 72) of the bypass pipe 12. Is introduced. As a result, the oil accumulated in the bottom 51 of the cooler case 3 is introduced into the second intake passage 62 on the downstream side of the throttle valve 7 via the bypass pipe 12 and sucked into the combustion chamber for each cylinder of the engine E. .
Therefore, the engine E, the intake duct, and the intercooler can be kept in a good state without continuously storing a large amount of oil in the bottom 51 of the cooler case 3 that is the lowermost part of the intake duct.
For some reason, for example, when a vehicle such as an automobile travels on a slope, the lowermost part of the intake duct is located above the intake port of the engine E in the direction of gravity, and the lubricating oil of the turbocharger, condensed water, etc. If a large amount of liquid is sucked into the combustion chamber of the engine E at a time, problems such as deterioration of the combustion state of the engine E, generation of white smoke, or reduction of emissions may occur. Occurrence can be prevented.
Moreover, corrosion of the cooler core 2 of the intercooler can be suppressed.

In addition, a drain valve 13 that opens and closes a drain passage 66 that is a communication path that communicates the bottom 51 of the cooler case 3 and the oil reservoir 65 of the bypass pipe 12 is provided in the middle of the drain pipe 11 of the oil discharge mechanism. .
In the drain valve 13, when the ignition switch is turned off (IG / OFF), the solenoid coil is turned off to fully open the drain flow path 66 (OPEN), and the ignition switch is turned on (IG / ON). When the solenoid coil is turned on, the drain channel 66 is fully closed (CLOSE) to open / close (ON-OFF operation). Here, when the operation of the engine E is stopped, the drain passage 66 is opened, so that the oil accumulated in the bottom 51 of the cooler case 3 is discharged (drained) to the oil reservoir 65 side of the bypass pipe 12. That is, oil that has accumulated in the bottom 51 of the cooler case 3 during normal operation of the engine E is drained to the oil reservoir 65 of the bypass pipe 12 while the operation of the engine E is stopped.

Further, when the engine E is in operation (normal operation), the drain passage 66 is closed so that the oil flows back to the bottom 51 side of the cooler case 3 when the oil in the bypass pipe 12 is introduced into the second intake passage 62. You can prevent problems.
In addition, it is difficult for the drain valve 13 that actively passes the oil liquefied by the oil mist to guarantee the accuracy of the valve operation responsiveness to the control signal to the coil of the drain valve 13 for a long time due to adhesion such as deposit accumulation. There is a possibility.
Therefore, as described above, the drain valve 13 fully opens (opens) the drain passage 66 by turning off the solenoid coil, and fully closes (closes) the drain passage 66 by turning on the solenoid coil. It is desirable to implement ON-OFF control.

Further, on the intake pipe 54 side of the cooler case 3 of the bypass pipe 12 of the oil discharge mechanism, the first intake passage 61 of the intake duct, that is, the cooler inlet channel 57 of the intake pipe 54 of the cooler case 3, and the bypass pipe 12. The bypass valve 14 for opening and closing the first flow path 71 communicating with the oil storage section 65 is provided.
Further, in the intake duct structure configured such that the bottom 51 of the cooler case 3 that is the lowermost part of the intake duct is positioned on the upstream side of the throttle valve 7, the bottom 51 of the cooler case 3 and the oil reservoir of the bypass pipe 12. The bypass valve 14 is installed on the introduction port 73 side of the first flow path 71 of the bypass pipe 12 so as to be positioned above the direction of gravity with respect to 65. That is, the bypass valve 14 is not installed in an environment in which oil passes through the inside of the bypass valve 14 or in an environment in which the oil is immersed in the oil accumulated in the oil reservoir 65.
As a result, the oil accumulated in the bottom 51 of the cooler case 3 and the oil reservoir 65 of the bypass pipe 12 is introduced into the second intake passage 62 via the bypass pipe 12 and discharged into the combustion chamber for each cylinder of the engine E. Even in this case, oil can be prevented from passing through the bypass valve 14 installed in the bypass pipe 12.

This makes it difficult for adhesive such as deposits to adhere to the bypass valve 14, so that the accuracy of the valve operation responsiveness to the control signal to the coil of the bypass valve 14 can be ensured for a long time. Therefore, in order not to interfere with the engine E, an appropriate amount of oil discharged from the bottom 51 of the cooler case 3 at the bottom of the intake duct to the combustion chamber of each cylinder of the engine E is stably controlled for a long period of time. it can.
Further, the bypass valve 14 that controls the oil flow rate with high accuracy is configured so as not to become an oil environment in which oil mist is liquefied. Therefore, as described above, the duty ratio for controlling the ON / OFF time ratio of the coil of the bypass valve 14 is controlled. It is desirable to implement control.

Further, the oil reservoir 65 of the bypass pipe 12 and the second intake passage 62 of the intake duct, that is, the intake branch passage 45 of the intake manifold 9 are communicated with the intake manifold 9 side of the bypass pipe 12 of the oil discharge mechanism. A through valve 15 for opening and closing the two flow paths 72 is provided.
When the ignition switch is turned off (IG / OFF), the through valve 15 turns off the solenoid coil to fully open the second flow path 72 (OPEN), and the ignition switch is turned on (IG / ON). Then, the coil of the solenoid is turned on, and an opening / closing operation (ON-OFF operation) is performed so that the second flow path 72 is fully closed (CLOSE). Further, when the oil suction condition is satisfied, the solenoid coil is turned off and the second flow path 72 is fully opened (OPEN), and the oil suction using the intake negative pressure is performed.

Here, for example, when it is desired to eliminate the influence of the bypass pipe 12 during normal operation (operation) of the engine E, or when clean air enters the second flow path 72 from the second intake passage 62 due to the supercharging pressure of the turbocharger, the bypass The through valve 15 is set when the oil in the oil reservoir 65 of the pipe 12 is pushed out to the clean air and prevents the bypass valve 14 installed in the first flow path 71 from being soiled.
In addition, the through valve 15 that actively passes the oil liquefied by the oil mist guarantees the accuracy of the operation response of the valve of the through valve 15 to the control signal to the coil of the through valve 15 for a long time by adhesion such as deposit accumulation. May be difficult to do.

Therefore, as described above, the through valve 15 fully opens (opens) the first flow path 71 by turning off the solenoid coil, and fully closes (closes) the first flow path 71 by turning on the solenoid coil. It is desirable to implement ON-OFF control.
As mentioned above, it establishes by sharing the role of each valve 13-15. That is, the process of sucking up oil using the negative intake pressure is established while suppressing the adhesion of sticky substances such as deposits to the valves 13 to 15.

FIG. 2 shows a second embodiment of the present invention and is a diagram showing an engine control system (a structure for sucking up oil accumulated in an intake duct of an engine).
The through valve 15 is not set in the bypass pipe 12 of the oil discharge mechanism of this embodiment.
Other configurations are the same as those of the first embodiment.

  FIG. 3 shows a third embodiment of the present invention, and is a diagram showing an engine control system (a structure for sucking up oil accumulated in an intake duct of an engine).

The oil discharge mechanism of this embodiment includes a drain pipe 11, a bypass pipe 12, a drain valve 13, a bypass valve 14 and a through valve 15.
The drain pipe 11 is a communication pipe that communicates the bottom 51 of the cooler case 3 of the intercooler and the oil reservoir 65 of the bypass pipe 12 in the same manner as in the first and second embodiments.
Inside the drain pipe 11, a drain channel (communication channel, discharge channel) 66 for draining oil from the bottom 51 of the cooler case 3 to the oil reservoir 65 of the bypass pipe 12 is formed.

  Similarly to the first embodiment, the bypass pipe 12 has an oil storage section 65 for temporarily storing oil drained from the bottom 51 of the cooler case 3 via the drain flow path 66 in the drain pipe 11. Yes. Inside the bypass pipe 12, the clean air that has passed through the air cleaner 1 is sucked from the first intake passage 61 upstream of the throttle valve 7 in the intake flow direction via the oil reservoir 65 and from the throttle valve 7. A bypass flow path is formed to guide the second intake passage 62 on the downstream side in the flow direction.

In the bypass pipe 12, the introduction port 73 provided at the upstream end portion of the first flow path 71 in the air flow direction is the first intake passage 61, that is, the cooler case 3 on the downstream side of the intercooler cooler core 2 in the intake flow direction. The case main body 56 is opened at the outlet tank 56b.
Further, the drain port 52 of the cooler case 3, which is an oil introduction port of the drain pipe 11, is opened downstream of the intercooler cooler core 2 in the intake flow direction, that is, at the outlet tank 56 b of the case main body 56 of the cooler case 3. ing.

  When configured as described above, the drain port 52 of the drain pipe 11 and the introduction port 73 of the bypass pipe 12 are opened downstream of the intercooler cooler core 2 in the intake air flow direction. Considering the heat damage of the valve 14, there is no concern that the turbocharger is exposed to high temperatures due to the supercharging pressure. Therefore, by connecting the introduction port 73 of the first flow path 71 of the bypass pipe 12 and the drain port 52 of the drain pipe 11 downstream of the intercooler cooler core 2 in the intake air flow direction, the drain valve 13 and the bypass valve 14 are connected. It is possible to improve the operational reliability and durability.

[Modification]
In this embodiment, the bottom part of the cooler case 3 of the intercooler (the lowermost part in the gravitational direction of the cooler case 3) 51 is applied to the lowermost part of the intake duct in the gravitational direction (the vertical direction of the vehicle such as an automobile). The bottom of the compressor housing of the turbocharger (the bottom of the compressor housing in the direction of gravity), the bottom of the air connector 5 (the bottom of the air connector 5 in the direction of gravity), the throttle body 6 may be applied to the bottom portion (the lowermost portion of the throttle body 6 in the direction of gravity) and the bottom portion of the surge tank 41 of the intake manifold 9 (the lowermost portion of the surge tank 41 in the direction of gravity).

Further, as an internal combustion engine (for example, a drive source such as a generator, a compressor, a blower or the like or a vehicle running engine) mounted on a vehicle such as an automobile, not only a multi-cylinder diesel engine but also a multi-cylinder gasoline engine may be used. . Further, as the internal combustion engine (engine E), not only a multi-cylinder engine but also a single-cylinder engine may be used.
In this embodiment, an electromagnetic flow path opening / closing valve is applied as the drain valve 13 or the through valve 15, but an electromagnetic flow control valve may be applied as the drain valve 13 or the through valve 15.

In this embodiment, a drain pipe (communication) that communicates the bottom part (lowermost part (lowermost point) in the gravity direction of the intake duct) 51 of the intercooler and the oil storage part 65 of the bypass pipe 12 as the communication part. 11), the bottom part of the cooler case 3 of the intercooler (the lowest part (lowest point) in the gravity direction of the intake duct) 51 and the oil storage part 65 of the bypass pipe 12 are directly connected as the communication part. A communication port that communicates may be applied.
Moreover, you may provide the recessed part which forms a storage part inside below the gravity direction rather than the lowest part in the gravity direction of an intake duct.
In addition, as the liquid that accumulates in the reservoir, or the liquid that is sucked into the combustion chamber of the internal combustion engine (engine) from the reservoir using the intake negative pressure, moisture in the exhaust gas such as EGR gas is condensed and liquefied. Water, lubricating oil from a turbocharger, oil mist from a blow-by gas reduction device is condensed and liquefied, water in a purge gas from an evaporative fuel treatment device is condensed, liquefied condensed water, liquid fuel, and the like.

In the present embodiment, the air guided from the intake passage upstream of the throttle valve (intake throttle valve) 7 in the intake flow direction to the intake passage downstream of the intake throttle valve via the bypass flow path. As described above, clean air (or a mixed gas of clean air and EGR gas) discharged from the compressor of the turbocharger through the air cleaner 1 and via the junction with the low-pressure loop EGR system is used. Clean air discharged from the compressor of the turbocharger that passes through 1 and bypasses the junction with the low-pressure loop EGR system (or abolishes the low-pressure loop EGR system) may be used.
Further, instead of the low pressure loop EGR system that takes in EGR gas from the exhaust passage downstream of the turbocharger turbine or the exhaust purification device (catalyst 10) to the intake passage in the intake flow direction, the intake flow direction is higher than the turbocharger turbine. A high-pressure loop EGR system that takes in EGR gas from the upstream exhaust passage to the intake passage may be employed.
Although a turbocharger is used as a supercharger, a supercharger or an electric compressor may be used. Further, the supercharger may not be installed in the intake duct.

E engine (internal combustion engine)
DESCRIPTION OF SYMBOLS 1 Air cleaner 2 Intercooler cooler core 3 Intercooler cooler case 4 Intercooler cooler cover 5 Air connector 6 Throttle body 7 Throttle valve (Valve of intake throttle valve)
9 Intake manifold 11 Drain pipe (oil discharge mechanism, communication part, communication pipe)
12 Bypass pipe (oil discharge mechanism, bypass pipe)
13 Drain valve (oil discharge mechanism, electromagnetic flow path opening / closing valve, first control valve)
14 Bypass valve (oil discharge mechanism, electromagnetic flow control valve, second control valve)
15 Through valve (oil discharge mechanism, electromagnetic channel on-off valve, third control valve)
45 Intake manifold intake branch passage (intake passage downstream of the intake throttle valve in the air flow direction)
51 The bottom of the cooler case (the lowest part in the gravity direction of the intake duct)
57 Cooler inlet flow path of the cooler case (the intake passage on the upstream side of the air flow direction from the intake throttle valve)
61 First intake passage (intake passage on the upstream side in the air flow direction from the intake throttle valve)
62 Second intake passage (intake passage downstream of intake throttle valve in the air flow direction)
65 Oil reservoir (bypass channel)
66 Drain channel (communication channel, discharge channel)
71 1st channel (bypass channel)
72 Second channel (bypass channel)
73 Inlet port 74 Oil outlet port 56b Cooler case outlet tank (intake passage on the upstream side of the air flow direction from the intake throttle valve)

Claims (13)

(A) an intake duct through which intake air supplied to the combustion chamber of the internal combustion engine flows;
(B) an intake throttle valve for controlling the flow rate of intake air flowing through the intake duct;
(C) liquid discharge means for introducing the liquid accumulated in the intake duct downstream of the intake throttle valve in the air flow direction and discharging the liquid into the combustion chamber of the internal combustion engine;
In the intake device for an internal combustion engine having an intake structure formed so that the lowest part in the gravity direction of the intake duct is positioned upstream of the intake throttle valve in the air flow direction,
The liquid discharging means is a reservoir for storing liquid discharged from the lowermost part of the intake duct in the direction of gravity.
A bypass flow path for guiding fluid from an intake passage upstream of the intake throttle valve in the air flow direction to the intake passage downstream of the intake throttle valve via the storage portion;
And a flow rate control valve for controlling the flow rate of the fluid flowing through the bypass channel,
The intake device for an internal combustion engine, wherein the flow rate control valve is installed in the bypass flow path so as to be positioned in the gravity direction lower than the gravity direction lower part of the intake duct and the storage part. The intake device for an internal combustion engine according to claim 1,
The intake device for an internal combustion engine, wherein the liquid discharge means includes a communication portion that communicates the lowermost portion of the intake duct in the gravitational direction with the storage portion. The intake device for an internal combustion engine according to claim 2,
The communication part is a communication pipe having a flow path that communicates the lowermost part in the gravity direction of the intake duct and the storage part,
The intake device for an internal combustion engine, wherein the liquid discharge means includes a flow path opening / closing valve that opens and closes the flow path.   The intake device for an internal combustion engine according to any one of claims 1 to 3, wherein the bypass flow path is formed on an upstream side in an air flow direction with respect to the storage portion, and the intake throttle valve. The first flow path for guiding the fluid flowing in from the intake passage on the upstream side in the air flow direction to the storage unit and the downstream side in the air flow direction from the storage unit are accumulated in the storage unit. An intake device for an internal combustion engine, comprising: a second flow path for guiding a mixed fluid obtained by mixing a fluid with a liquid to an intake passage downstream of the intake throttle valve in an air flow direction. The intake device for an internal combustion engine according to claim 4,
The intake device for an internal combustion engine, wherein the flow rate control valve controls the flow rate of a mixed fluid obtained by changing the opening area of the first flow path and mixing the fluid with the liquid accumulated in the storage portion. The intake apparatus for an internal combustion engine according to claim 4 or 5,
The intake device for an internal combustion engine, wherein the liquid discharge means includes a flow path opening / closing valve that opens and closes the second flow path.   The intake device for an internal combustion engine according to any one of claims 4 to 6, wherein the first flow path is opened through an intake passage upstream of the intake throttle valve in an air flow direction. An intake device for an internal combustion engine, comprising a port.   The intake device for an internal combustion engine according to any one of claims 4 to 7, wherein the second flow path is opened at an intake passage downstream of the intake throttle valve in an air flow direction. An intake device for an internal combustion engine, comprising a port.   The intake device for an internal combustion engine according to any one of claims 1 to 8, further comprising an intercooler having a core for cooling the intake air compressed by the supercharger by exchanging heat with a cooling medium. An intake device for an internal combustion engine characterized by the above. The intake device for an internal combustion engine according to claim 9,
The intercooler has a cooler case that houses the core,
The cooler case has a bottom portion where a liquid obtained by liquefying oil mist or condensed water is accumulated,
An intake device for an internal combustion engine, wherein a bottom portion of the cooler case constitutes a lowermost portion of the intake duct in a gravitational direction. The intake device for an internal combustion engine according to any one of claims 1 to 10,
An intercooler having a core that cools the intake air compressed by the supercharger by exchanging heat with a cooling medium, and a cooler case that houses the core;
A throttle device having a throttle body that houses the intake throttle valve;
An air connector communicating the cooler case and the throttle body;
The air connector has a bottom portion in which a liquid obtained by liquefying oil mist or condensed water is accumulated,
An intake device for an internal combustion engine, wherein a bottom portion of the air connector constitutes a lowermost portion in the gravity direction of the intake duct. The intake device for an internal combustion engine according to claim 10 or 11,
The intake device for an internal combustion engine, wherein the bypass flow path has an introduction port opened in an intake passage upstream of the core in the air flow direction. The intake device for an internal combustion engine according to claim 10 or 11,
The intake device for an internal combustion engine, wherein the bypass flow path has an introduction port opened in an intake passage downstream of the core in the air flow direction.

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