JP5505267B2 - Intake air cooling system - Google Patents

Description

  The present invention relates to an intake air cooling device that cools intake air sucked into an engine (internal combustion engine) by disposing a water-cooled intercooler inside a surge tank.

A technique has been proposed in which a water-cooled intercooler is disposed inside a surge tank (generally, inside a surge tank provided in an intake manifold) (see, for example, Patent Document 1).
Thus, by arranging the intercooler inside the surge tank, the intake air sucked into the engine can be cooled, and the space for mounting the intercooler can be secured.

The intercooler is a heat exchanger that exchanges heat between the cooling water and the intake air, and the cooling water passes through the interior of the intercooler.
This type of intercooler is manufactured with high quality control so as not to cause cooling water leakage even when used for a long period of time.
However, when the vehicle is used in an unexpected harsh usage environment (excessive vibration, intake including unexpected seawater, etc.), the vehicle is used for an unexpectedly long period of time, or in vehicle maintenance, etc. It is assumed that an excessive load or impact may be applied to the joint of the intercooler or cooling water piping.

Assuming that cracks or holes have occurred in the cooling water passage in the intercooler or the joint between the intercooler and the cooling water piping due to corrosion or stress fatigue, cooling water can leak from the intercooler into the surge tank. There is sex.
For this reason, even if the coolant leaks from the intercooler into the surge tank, it is necessary to prevent the coolant leaked into the surge tank from being sucked into the engine.

Special table 2010-510425 gazette

  The present invention has been made in view of the above problems, and the purpose of the present invention is to prevent the cooling water leaking into the surge tank even if the cooling water leaks into the surge tank from the intercooler. An object of the present invention is to provide an intake air cooling device that is not sucked into an engine.

[Means of Claim 1]
In the intake air cooling device according to the first aspect, a catch tank communicating with the bottom of the surge tank via the communication portion is provided under the surge tank.
For this reason, even if the coolant leaks into the surge tank from the intercooler, the coolant leaked into the surge tank is stored in the catch tank below and leaks into the surge tank. The trouble that the cooling water is sucked into the engine can be avoided.
That is, the reliability of the vehicle in which the water-cooled intercooler is arranged inside the surge tank can be improved.

In particular, according to the intake air cooling device of the means of claim 1, the coolant leaked from the coolant circulation circuit of the intercooler leaked into the level sensor or the surge tank that detects that the leak amount has reached a predetermined leak amount. A level sensor is provided for detecting that the cooling water leakage amount has reached a predetermined leakage amount.
On the other hand, the capacity of the catch tank is ensured to be equal to or greater than a predetermined leakage amount detected by the level sensor.
An engine control device (engine control unit: hereinafter referred to as ECU) that controls the operation of the engine detects a leakage of the cooling water by the level sensor (specifically, the cooling water by the level sensor). When it detects that the leak has reached the specified leak)
(I) stop the operation of the water pump in the cooling water circulation circuit;
(Ii) switch the operating state of the engine to the evacuation travel mode,
(Iii) The display device for the vehicle occupant is operated to notify the vehicle occupant of the occurrence of an abnormality.

By adopting the above configuration, even if the coolant leaks from the intercooler into the surge tank, the leaked coolant is not detected until the level sensor detects the coolant leak. Since the catch tank stores all the water, there is no problem that the coolant leaked into the surge tank is sucked into the engine. At this time, since the ECU does not restrict the operation of the engine, the driver can drive the vehicle freely.
Further, after the level sensor detects the leakage of the cooling water, the ECU switches the engine operating state to the evacuation travel mode, thereby suppressing an increase in engine rotation. For this reason, even if the cooling water accumulates in the lower part of the surge tank, the problem that the cooling water is sucked into the engine does not occur.

Here, the normal intercooler is mounted in order to cool the intake air that has been pressurized by an intake supercharger such as a turbocharger or a supercharger and has risen in temperature.
The volume of the intake passage through which the intake air pressurized by the intake supercharger is guided (volume of the intake passage from the compressor to the engine) is required to be small for the purpose of improving the response of the accelerator.
Therefore, by adopting the above configuration (a configuration in which the cooling water is stored in the catch tank until the leakage amount of the cooling water reaches the predetermined leakage amount and is switched to the evacuation travel mode after reaching the predetermined leakage amount), the catch is achieved. The capacity of the tank can be kept small. That is, it is possible to suppress the deterioration of the accelerator response due to the provision of the catch tank.

[Means of claim 2 ]
According to the second aspect of the present invention, even when the cooling water is leaked to the maximum in the surge tank from the intercooler while the water pump of the cooling water circulation circuit is stopped, Make sure that the cooling water accumulated in the tank does not block the intake and intake ports of the surge tank.
(I) The vertical arrangement relationship between the radiator and the intercooler in the cooling water circulation circuit is set,
(Ii) the arrangement of intake passages (for example, intake pipe routing) leading to the surge tank is set,
(Iii) The shape, size, and vertical position of the intake inlet and the intake outlet of the surge tank are set.
For this reason, even after the level sensor detects that the cooling water leakage amount has reached the predetermined leakage amount, the retreat traveling is enabled.

It is a schematic block diagram of an intake air cooling device (Example). It is principal part sectional drawing of the intake manifold by which an intercooler is arrange | positioned inside (Example). It is the schematic of an intake manifold (other examples).

[Description of Embodiments] [Mode for carrying out the invention] will be described with reference to the drawings.
Intake air cooling system
An intake manifold 3 having a surge tank 1 for reducing intake pulsation and interference and a plurality of intake branches 2 branched from the surge tank 1;
A water-cooled intercooler 4 that is disposed inside the surge tank 1 and cools the intake air passing through the surge tank 1;
Cooling water circulation having a radiator 5 that radiates cooling water, an electric water pump 6 that circulates the cooling water, and a reserve tank 7 that can store a predetermined amount of cooling water, and that circulates cooling water to the intercooler 4 Circuit 8;
A catch tank 10 provided below the surge tank 1 (any one of the lower side, the lower part, and the lower side) and communicating with the bottom of the surge tank 1 via the communication part 9;
A level sensor 11 that detects that the amount of coolant leaked from the coolant circulation circuit 8 has reached a predetermined leak amount (or that the amount of coolant leaked into the surge tank 1 has reached a predetermined leak amount) Is provided with a level sensor 11).

And the capacity | capacitance of the catch tank 10 has ensured the capacity | capacitance more than the predetermined leakage amount which the level sensor 11 detects.
Furthermore, when the ECU 12 that performs engine control detects the leakage of the cooling water by the level sensor 11,
(I) Stop the operation of the water pump 6 in the cooling water circulation circuit 8;
(Ii) switching the operating state of the engine to a retreat traveling mode (an operation mode in which the upper limit of the engine speed is limited to be low);
(Iii) The display device 13 for the vehicle occupant is operated to notify the vehicle occupant of the occurrence of an abnormality.
The catch tank 10 may be provided integrally with the surge tank 1 (a part of the intake manifold 3), or provided separately from the surge tank 1 and communicated by piping or the like. There may be.

  Hereinafter, a specific example (example) to which the present invention is applied will be described with reference to the drawings. The embodiment discloses a specific example, and it goes without saying that the present invention is not limited to the embodiment. In the following embodiments, the same reference numerals as those in the “DETAILED DESCRIPTION OF THE INVENTION” denote the same functional objects.

(Specific Configuration 1 of Example)
An engine for driving a vehicle (which may be a spark ignition engine such as a gasoline engine or a compression ignition engine such as a diesel engine) includes an intake passage that guides intake air into the cylinder and exhaust gas generated in the cylinder. And an exhaust passage for discharging the air into the atmosphere.

The intake passage is configured by an intake pipe 15 in which an air cleaner, a throttle valve 14 and the like are arranged, an intake manifold 3 that distributes intake air to each cylinder, and an intake port 17 formed in a cylinder head 16 of the engine.
The intake manifold 3 is provided with an enlarged passage cross-sectional area to reduce intake pulsation and intake interference, and a plurality of intake branches 2 that distribute intake air in the surge tank 1 to each cylinder of the engine. Are integrated with a resin or the like.
The exhaust passage includes an exhaust port formed in the cylinder head 16 of the engine, an exhaust manifold that collects exhaust gas discharged from each exhaust port, a three-dimensional catalyst (in the case of a spark ignition engine), or a particulate filter (compression ignition). And in the case of an engine).

The vehicle of this embodiment is equipped with an intake supercharger (turbocharger, supercharger, etc.) that pressurizes intake air by a compressor. A water-cooled intercooler 4 that forcibly cools the intake air that has been compressed by the compressor and increased in pressure to a high temperature is disposed in the intake passage on the intake air downstream side of the intake turbocharger.
The intercooler 4 is inserted and disposed inside the surge tank 1 in the intake manifold 3 and is provided so as to cool all the intake air passing through the surge tank 1.

  The intercooler 4 is a functional component of the cooling water circulation circuit 8 through which the cooling water circulates. In addition to the intercooler 4, the cooling water circulation circuit 8 includes a radiator 5 that radiates cooling water, and a water pump that circulates the cooling water. 6. It has a reserve tank 7 that can store a predetermined amount of cooling water, and adopts a configuration in which each functional component is joined in an annular shape by cooling water piping.

The radiator 5 is mounted on a portion that receives the vehicle running wind (such as the interior of the front grille of the vehicle), receives the running wind, receives the fan wind of the radiator fan that cools the engine cooling water, and the cooling water is efficient. It is provided so as to be cooled.
The water pump 6 is an electric pump whose operation is controlled by energization, and the operation is controlled by an ECU 12 that controls the operating state of the engine.
The reserve tank 7 is disposed at a position higher than the intercooler 4, the radiator 5, and the water pump 6 (upward in the vertical direction when the vehicle is mounted), and the intercooler 4, the radiator 5, and the water pump 6 are always filled with cooling water. It is provided as follows.
In addition, although the cooling water circulation circuit 8 shown in this Example is provided independently of other cooling water circuits, such as an engine cooling water circulation circuit, it is not limited.

The intake manifold 3 of this embodiment has a catch tank 10 that communicates with the bottom of the surge tank 1 via the communication part 9 at the lower part of the surge tank 1 (lower side in the vertical direction when the vehicle is mounted).
In addition, although the catch tank 10 of this Example shows the example provided integrally as a part of the intake manifold 3 with the surge tank 1 and the intake branch 2, it is not limited, The catch tank 10 is attached to the surge tank 1 ( It may be provided by a member independent of the intake manifold 3) and disposed below the surge tank 1 so that the lower part of the surge tank 1 and the catch tank 10 communicate with each other using piping or the like.

As described above, the catch tank 10 of this embodiment is integrated with the surge tank 1 (intake manifold 3), and the interior wall of the surge tank 1 and the interior space of the catch tank 10 are separated by the bottom wall of the surge tank 1. Is partitioned.
A communication portion 9 that communicates the bottom of the surge tank 1 and the upper portion of the catch tank 10 is a through hole formed in the surge tank 1 and is an opening that constantly communicates the bottom portion of the surge tank 1 and the upper portion of the catch tank 10. .

Note that the cooling water in the catch tank 10 flows back into the surge tank 1 even if the vehicle turns and the vehicle runs on a slope or accelerates or decelerates while the cooling water is stored in the catch tank 10. It is devised not to.
As a specific example, the communication portion 9 is provided near the approximate center of the ceiling wall of the catch tank 10 (the bottom wall of the surge tank 1).
Alternatively, a baffle plate (partially connecting partition wall) that suppresses the movement of the cooling water is disposed inside the catch tank 10, or a pipe (a pipe having an opening in the side surface direction) is provided below the communication portion 9. Thus, the cooling water in the catch tank 10 is provided so that it does not flow back into the surge tank 1 even if the vehicle travels with the cooling water stored in the catch tank 10.

The reserve tank 7 is provided with a level sensor 11 that detects that the liquid level of the cooling water stored in the reserve tank 7 has reached a predetermined liquid level.
The level sensor 11 indicates that the amount of cooling water leaked from the cooling water circulation circuit 8 has reached a predetermined leakage amount (for example, 1L: this value is merely a numerical value for assisting understanding and is not limited). Is detected.
That is, the level sensor 11 indicates that the coolant level in the reserve tank 7 has decreased by a predetermined leakage amount (for example, 1 L) from the reference level (full water level: see the broken line in the reserve tank 7 in FIG. 1). It is a sensor to detect.
The sensor output of the level sensor 11 is input to the ECU 12.

Here, the catch tank 10 has a capacity equal to or greater than a predetermined leakage amount detected by the level sensor 11.
As a specific numerical example for assisting understanding, if the predetermined leakage amount detected by the level sensor 11 is “1L”, the capacity of the catch tank 10 is set to 1 L or more (eg, 1.1 L). is there. Of course, this value is not limited.
That is, assuming that the coolant leaks from the intercooler 4 into the surge tank 1, the liquid level α when the coolant leak is detected by the level sensor 11 is as shown in FIGS. In addition, it exists in the catch tank 10 and is provided so that the cooling water does not accumulate in the surge tank 1.

On the other hand, when it is assumed that the coolant has leaked from the intercooler 4, the coolant has leaked to the maximum in the surge tank 1 from the intercooler 4 with the water pump 6 of the coolant circulation circuit 8 stopped. Then, it is conceivable that the catch tank 10 is filled with water and the cooling water is accumulated inside the surge tank 1.
Even when such a situation occurs, the intake air inlet 1a of the surge tank 1 (the intake air inlet of the intake manifold 3) and the intake air outlet 1b of the surge tank 1 (the intake air inlet of the intake branch 2) accumulate in the surge tank 1. Provided not to be blocked by water.

Specifically, the liquid level β when the coolant leaks from the intercooler 4 into the surge tank 1 with the water pump 6 stopped is the surge level as shown in FIGS. The cooling water accumulated in the tank 1 should not block the intake passage.
(I) The vertical arrangement relationship between the intercooler 4 and the radiator 5 is set (for example, the radiator 5 is arranged as low as possible with respect to the intercooler 4),
(Ii) The arrangement of the intake passage of the surge tank 1 is set (for example, the intake pipe 15 connected to the surge tank 1 extends in the horizontal direction as much as possible),
(Iii) The shape, size, and vertical position of the intake inlet 1a and the intake outlet 1b of the surge tank 1 are set (for example, as shown in FIG. 2, the intake inlet 1a of the surge tank 1 is provided vertically and the surge The intake outlet 1b of the tank 1 is disposed in the upper part of the surge tank 1).
The positions of the liquid level α and β shown in FIGS. 1 and 2 are reference water levels for assisting understanding and are not limited.

The ECU 12 is equipped with a computer having a well-known configuration including a CPU, a storage device, an input / output device, and the like. The ECU 12 copes with cooling water leakage when the level sensor 11 detects leakage of cooling water. A leakage countermeasure program is installed.
When this leakage countermeasure program detects the leakage of cooling water by the level sensor 11, (i) the operation of the water pump 6 in the cooling water circulation circuit 8 is stopped (energization is stopped)
(Ii) switch to a retreat travel mode that restricts the upper limit of the engine speed to a predetermined speed or less (eg, 2000 rpm or less);
(Iii) The display device 13 for the vehicle occupant (for example, a visual display means such as an abnormality warning light) is actuated (lighted) to notify the vehicle occupant (driver) of the occurrence of an abnormality.

(Effect 1 of an Example)
In the intake air cooling apparatus in this embodiment, when a situation in which cooling water leaks from the intercooler 4 into the surge tank 1 occurs, all of the leaked cooling water is detected until the level sensor 11 detects the occurrence of cooling water leakage. The catch tank 10 stores water. For this reason, there is no problem that the engine sucks the cooling water leaked from the intercooler 4.
At this time (when the coolant leaks and the leak amount does not reach the predetermined leak amount), the ECU 12 does not restrict the operation of the engine (because it does not switch to the retreat travel mode), so the driver can freely move the vehicle. Can drive without any problems.

When the level sensor 11 detects cooling water leakage, the ECU 12 stops the operation of the water pump 6. As a result, the cooling water in the cooling water circulation circuit 8 is not forced to be pumped to the intercooler 4, so that the cooling water is excessively leaked from the intercooler 4 (“the intercooler 4 with the water pump 6 stopped. The amount of cooling water leaking into the surge tank 1) can be avoided.
That is, even if the cooling water leaks from the intercooler 4 to the maximum, the cooling water accumulated in the surge tank 1 does not block the intake inlet 1a and the intake outlet 1b of the surge tank 1.

  Further, when the level sensor 11 detects the leakage of the cooling water, the ECU 12 switches the engine operating state to the retreat travel mode. Since the engine rotation is suppressed by the retreat travel mode, even if cooling water is stored in the lower part of the surge tank 1, there is no problem that the coolant is sucked into the engine, and the vehicle retreat travel is performed. Can do.

  Furthermore, when the level sensor 11 detects a leakage of cooling water, the ECU 12 operates the display device 13 to notify the vehicle occupant of the occurrence of an abnormality. Thereby, the vehicle occupant can know that an abnormality has occurred in the vehicle, and can understand that the operating state of the engine has been automatically switched to the retreat travel mode.

On the other hand, the vehicle equipped with the intake air cooling device in this embodiment is equipped with the intake air supercharger as described above. In a vehicle equipped with an intake supercharger, it is required to reduce the volume of the intake passage from the compressor to the engine for the purpose of improving the responsiveness of the accelerator.
Therefore, in this embodiment, as described above, until the level sensor 11 detects the leakage of the cooling water, the cooling water is stored in the catch tank 10, and after the level sensor 11 detects the leakage of the cooling water (cooling) By adopting a configuration in which the engine operating state is switched to the retreat travel mode after the water leakage amount reaches the predetermined leakage amount, the capacity of the catch tank 10 can be kept small.
That is, although the catch tank 10 communicating with the surge tank 1 is provided, since the capacity of the catch tank 10 can be reduced, it is possible to suppress the deterioration of the responsiveness of the accelerator.

(Specific configuration 2 of the embodiment)
Next, a technique for discharging water (water different from cooling water) or oil generated in the surge tank 1 or guided into the surge tank 1 will be described.
As described above, the intercooler 4 is disposed inside the surge tank 1. For this reason, when the intake air is cooled by the intercooler 4 and condensed water is generated, the condensed water drops into the surge tank 1.

On the other hand, the blowby gas generated in the engine (mixed gas of unburned gas and exhaust gas that has entered the crankcase from the combustion chamber) is supplied to the engine in the middle of the intake passage (for example, the intake upstream portion of the surge tank 1). A blow-by gas recirculation device is provided to return water and oil contained in the blow-by gas into the surge tank 1 by the flow of intake air.
Further, the engine is provided with an EGR device (exhaust gas recirculation device) for returning a part of the exhaust gas as EGR gas to the middle of the intake passage (for example, near the boundary between the surge tank 1 and the intake branch 2). Water or oil contained in the EGR gas is guided into the surge tank 1 by intake pulsation or the like.

As described above, the water or oil generated in the surge tank 1 or guided into the surge tank 1 is stored in the catch tank 10 provided in the lower part of the surge tank 1.
In view of this, the intake air cooling device of this embodiment has a water oil discharge means for sucking water and oil stored in the catch tank 10 into the intake branch 2 by intake negative pressure generated in the intake passage and sucking it into the engine. It is installed.

This water oil discharge means
A first communication pipe 21 communicating the lower part of the catch tank 10 and the inside of the intake branch 2;
A second communication pipe 22 that communicates the inside of the catch tank 10 with the atmosphere (or in the intake passage on the upstream side of the intake of the throttle valve 14: within a range where the generation of intake negative pressure is weak);
An electric on-off valve 23 for opening and closing the second communication pipe 22 (for example, a vacuum switching valve: VSV using intake negative pressure);
-It is comprised with ECU12 which performs the opening degree control of this electric on-off valve 23 according to the driving | running state of an engine.
In addition, the code | symbol 24 in FIG. 2 is a filter attached to an air introduction port, when the electrically operated opening / closing valve | bulb 23 is connected to air | atmosphere.

The ECU 12 is equipped with a water oil suction program for controlling the opening degree of the electric opening / closing valve 23 in accordance with the operating state of the engine.
This water-oil suction program is used when the engine is in an operating state where no problem occurs even if a small amount of water or oil is mixed into the combustion chamber along with intake air (for example, when the fuel is cut during deceleration, etc. When stopping or when driving at a low load, etc., the electric open / close valve 23 is opened in a small amount (for example, VSV is opened in a small amount by controlling the duty ratio of the solenoid valve in the VSV), and the water or oil stored in the catch tank 10 Makes the engine suck small amounts.

(Effect 2 of Example)
The intake air cooling device of this embodiment causes the engine to suck water or oil stored in the catch tank 10 by the water oil discharge means described above. Thereby, the inside of the catch tank 10 can always be kept almost empty.
For this reason, even if the cooling water leaks from the intercooler 4, the inside of the catch tank 10 is kept almost empty, so that the leakage occurred until the level sensor 11 detects the leakage of the cooling water. All of the cooling water can be stored in the catch tank 10, and there is no problem that the cooling water is sucked into the engine.

  In the above embodiment, the level sensor 11 is provided in the reserve tank 7 to detect that the leakage amount of the cooling water in the cooling water circulation circuit 8 has reached the predetermined leakage amount, but as shown in FIG. A level sensor 11 may be provided in the catch tank 10 so as to detect that the amount of cooling water leaked into the surge tank 1 has reached a predetermined amount.

  In the above embodiment, the surge tank 1 is provided in the intake manifold 3. However, the surge tank 1 is provided independently of the intake manifold 3 (intake branch pipe), and the surge tank 1 is provided inside the independent surge tank 1. You may apply this invention to what has arrange | positioned the cooler 4. FIG.

In the above embodiment, the first and second communication pipes 21 and 22 are provided by pipes (tubes or the like) independent of the intake manifold 3. However, the first and second communication pipes 21 and 22 are provided by the intake manifold 3. It may be provided integrally with the.
The water oil discharging means (technology for causing the engine to suck water and oil in the catch tank 10) disclosed in the above embodiment is a specific example, and water and oil stored in the catch tank 10 by other technologies. May be provided so that the engine can be sucked.

DESCRIPTION OF SYMBOLS 1 Surge tank 1a Intake inlet 1b Intake outlet 2 Intake branch 4 Intercooler 5 Radiator 6 Water pump 7 Reserve tank 8 Coolant circulation circuit 9 Communication part 10 Catch tank 11 Level sensor 12 ECU (engine control device)
13 Display device

Claims (2)

A surge tank (1) having an enlarged passage cross-sectional area in an intake passage that guides intake air to the engine;
A water-cooled intercooler (4) disposed inside the surge tank (1) for cooling the intake air passing through the surge tank (1);
A catch tank (10) provided under the surge tank (1) and communicating with the bottom of the surge tank (1) via the communication portion (9);
An intake air cooling device comprising :
This intake air cooling device
A level sensor (11) that detects that the amount of coolant leaked from the coolant circulation circuit (8) that circulates and supplies coolant to the intercooler (4) reaches a predetermined leak amount, or the surge tank (1) ) Having a level sensor (11) for detecting that the amount of cooling water leaked in has reached a predetermined amount of leakage,
The capacity of the catch tank (10) secures a capacity equal to or greater than a predetermined leakage amount detected by the level sensor (11).
The engine control device (12) for controlling the operation of the engine stops the operation of the water pump (6) in the cooling water circulation circuit (8) when the leakage of the cooling water is detected by the level sensor (11). The intake air cooling device is characterized in that the operating state of the engine is switched to the evacuation travel mode, and a display device (13) for the vehicle occupant is operated to notify the vehicle occupant of the occurrence of an abnormality. The intake air cooling device according to claim 1,
With the water pump (6) stopped, even if the coolant leaks from the intercooler (4) into the surge tank (1) to the maximum,
The cooling water accumulated in the surge tank (1) does not block the intake inlet (1a) and the intake outlet (1b) of the surge tank (1).
The vertical arrangement relation of the radiator (5) and the intercooler (4) in the cooling water circulation circuit (8) is set,
The arrangement of intake passages leading to the surge tank (1) is set,
The intake air cooling device , wherein the shape, size, and vertical position of the intake inlet (1a) and the intake outlet (1b) of the surge tank (1) are set .

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