JP5720533B2 - Engine intake system - Google Patents

Description

  The present invention relates to an engine intake device including an intercooler that cools intake air.

  2. Description of the Related Art Conventionally, there is a technique for cooling intake air by disposing an intercooler inside a surge tank that forms a part of an intake passage to a combustion chamber of an engine (internal combustion engine) (see, for example, Patent Document 1).

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 and holes are generated due to corrosion and stress fatigue at the cooling water pipe in the intercooler and at the joint between the intercooler and the cooling water pipe, the cooling water leaks from the intercooler into the intake passage. there is a possibility.
For this reason, even if the cooling water leaks from the intercooler, it is necessary to prevent the leaked cooling water from being sucked into the engine.

Therefore, there is a technique of providing a catch tank into which the cooling water can flow even if the cooling water leaks from the intercooler.
However, since the catch tank communicates with the intake passage, during normal operation, oil from the turbocharger and the probe gas reduction device (PCV system) reaches the location where the catch tank is connected and flows into the catch tank. There is a risk of it.
If oil accumulates in the catch tank, when cooling water leaks from the intercooler, the capacity for storing the cooling water decreases.
For this reason, when cooling water leaks from the intercooler without oil flowing into the catch tank during normal operation, a structure is required to prevent the leaked cooling water from being sucked into the combustion chamber.

Special table 2010-510425 gazette

  The present invention has been made to solve the above problems, and its purpose is to prevent leakage of cooling water from the intercooler without oil flowing into the catch tank during normal operation. Another object of the present invention is to provide an engine intake device in which the cooling water is not sucked into the combustion chamber.

[Means of Claim 1]
The engine intake device according to claim 1 includes an intake pipe that forms an intake passage through which intake air drawn into the combustion chamber of the engine flows, an intercooler that cools the intake air with cooling water, and cooling water that has leaked from the intercooler flows in And a catch tank.

  The catch tank is connected to a location where the coolant that has leaked most easily collects in the intake passage. When the gravity direction is the downward direction, the communication port to the intake pipe of the catch tank is the top of the intake pipe. It opens upward from the lower part.

  According to this, if cooling water leaks from the intercooler, the cooling water can be stored in the catch tank. And even if the oil from the turbocharger or the probe gas reduction device reaches the location where the catch tank is connected in the intake passage and accumulates at the bottom of the intake pipe during normal operation, the communication port with the catch tank Since it is above the lowermost part of the intake pipe, oil does not immediately flow into the catch tank.

The catch tank has a communication port at the tip and is connected to the intake pipe and has a communication pipe that communicates the inside of the catch tank and the intake pipe. The communication pipe has a tip at the inner periphery of the intake pipe. It protrudes inward from the surface and is connected to the intake pipe. The tip of the communication pipe is inclined downward with respect to the horizontal direction so that the tip is downward .
Oil flows along the inner peripheral surface of the intake pipe. For this reason, if the communication port is opened on the inner peripheral surface of the intake pipe, the oil tends to flow into the catch tank. In this means, since the communication port is located at the position protruding inward from the inner peripheral surface of the intake pipe, the oil flowing along the inner peripheral surface can be further suppressed from flowing into the catch tank.

[Means of claim 2 ]
According to the engine intake device of the second aspect , the intake pipe in the vicinity of the communication port has a concave portion recessed downward on the inner peripheral surface of the lower pipe wall.
According to this, the oil that has reached the vicinity of the communication port in the flow direction is guided to the recess and stored in the recess. For this reason, if the opening position of the communication port is set higher than the recess, the inflow of oil into the catch tank can be suppressed. And since the opening position of a communicating port can be made below compared with the case where there is no recessed part, even if it is a small amount of cooling water which leaked from the intercooler, it can guide | invade quickly into a catch tank.

1 is an overall configuration diagram of an engine intake device (Example 1). (Example 1) which is explanatory drawing explaining the connection part of an intake pipe and a catch tank. FIG. 2 is an overall configuration diagram of an engine intake device (Example 2). (Example 3) which is explanatory drawing explaining the connection part of an intake pipe and a catch tank. It is a whole block diagram of an engine intake device (modification).

  The mode for carrying out the present invention will be described in detail with reference to the following examples.

[Configuration of Example 1]
An intake device 1 according to the first embodiment will be described with reference to FIGS. 1 and 2.
The intake device 1 includes an intake pipe 5 that forms an intake passage 4 through which intake air taken into the combustion chamber 2a of the engine body 2 flows, an intercooler 8 that cools intake air using cooling water, a throttle device 9 that adjusts the intake air amount, And a catch tank 10 described later.

In the intake passage 4 of this embodiment, a throttle device 9, a catch tank 10, and an intercooler 8 are arranged in order from the downstream side.
The vehicle of the present embodiment is equipped with a supercharger (not shown) that pressurizes intake air by a compressor, and intake air that has been pressurized by the compressor and increased in temperature flows into the intercooler 8. .
Although not shown, a pipe of a probe gas reduction device (PCV system) is connected to the intake passage 4 between the throttle device 9 and the combustion chamber 2a and communicates with the inside of the crankcase 2b.

  The intercooler 8 is a water-cooled type and has a well-known structure having a cooling passage through which cooling water flows. A cooling water pipe (not shown) is connected to the cooling passage, and cooling water is supplied to and drained from the intercooler 8 through the cooling water pipe.

The intake pipe 5 that forms the intake passage 4 downstream from the accommodation space 11 in which the intercooler 8 is accommodated is inclined downward (downward in the direction of gravity) from the outlet 11a of the accommodation space 11 in which the intercooler 8 is accommodated. The intake pipe 5 that extends and forms the intake passage 4 between the intercooler 8 and the throttle device 9 has a curved portion 13 that curves so as to protrude downward. And the position used as the lowest part of the curved part 13 (henceforth the lowest part 13a) is located below the bottom part 11b of the storage space 11. FIG.
For this reason, the vicinity of the lowermost part 13a is a place in the intake passage 4 where the cooling water easily collects when the cooling water leaks from the intercooler 8.

[Features of Example 1]
The intake device 1 of the present embodiment includes a catch tank 10 into which cooling water leaked from the intercooler 8 flows downstream of the intercooler 8.
The catch tank 10 communicates with a location in the flow direction in which the coolant that has leaked in the intake passage 4 is most likely to accumulate. That is, in this embodiment, the communication position of the catch tank 10 to the intake passage 4 in the flow direction is near the lowermost portion 13a.
The intake pipe 5 forming the curved portion 13 is a circular pipe, and the cross section perpendicular to the flow direction in the lowermost part 13a is circular as shown in FIG.

The catch tank 10 has a communication pipe 16 connected to the intake pipe 5.
As shown in FIG. 2, the communication pipe 16 has a distal end portion 16 a that is a connection side to the intake pipe 5, and a connection portion 16 b that is formed between the distal end portion 16 a and the catch tank 10. The connecting portion 16b extends upward from the catch tank 10, and the tip portion 16a is bent from the connecting portion 16b and is provided so as to be connected to the intake pipe 5.
And the opening 16c used as the communicating port to the intake pipe 5 is formed in the front-end | tip of the front-end | tip part 16a.
In addition, the front-end | tip part 16a is extended from the front-end | tip of the connection part 16b so that it may incline below slightly with respect to a horizontal direction.

Further, in the lowermost part 13 a of the intake passage 4, the opening 16 c is located above the lowermost part 5 a in the intake pipe 5.
That is, the opening 16c is above the oil level of the oil that may be transmitted and stored from the probey gas reduction device or the supercharger, and below the allowable water level in the intake pipe 5 of the leaked cooling water. It is open.

[Effects of Example 1]
In the present embodiment, the communication position of the catch tank 10 to the intake passage 4 in the flow direction is near the lowermost portion 13a. An opening 16 c that is a communication port between the catch tank 10 and the intake pipe 5 is located above the lowermost part 5 a of the intake pipe 5.
Hereinafter, the operation and effect will be described by dividing into normal operation and cooling water leakage (emergency when cooling water leaks from the intercooler 8).

(1) During normal operation During normal operation, the oil from the turbocharger or the probe gas reducing device flows along the inner peripheral surface of the intake pipe 5 through the intake passage 4 according to the flow velocity, and travels toward the engine body 2. At this time, the oil may reach near the lowermost part 13a and be stored near the lowermost part 5a of the intake pipe 5 due to gravity. However, at this time, since the oil level has not reached the position of the opening 16 c that is a communication port to the catch tank 10, the oil does not flow into the catch tank 10.

Further, since the opening 16c is not located on the inner peripheral surface of the intake pipe 5 but at a position projecting inward from the inner peripheral surface, it is possible to suppress oil flowing along the inner peripheral surface from flowing into the catch tank 10 from the opening 16c.
It should be noted that the oil is transmitted to the inner peripheral surface of the tip end portion 16a because the tip end portion 16a of the communication pipe 16 extends from the tip end of the connecting portion 16b so as to be inclined slightly downward with respect to the horizontal direction. However, it is returned to the opening 16c side by gravity, and oil is prevented from reaching the inside of the catch tank 10.

(2) When cooling water leaks When cooling water leaks from the intercooler 8, the cooling water accumulates below the intake pipe 5 due to gravity. When the water level reaches the position of the opening 16c, the cooling water flows into the catch tank 10 from the opening 16c, and the cooling water can be accumulated in the catch tank 10 (see the two-dot chain line and the arrow in FIG. 2).

  That is, when the coolant leaks from the intercooler 8 without flowing oil into the catch tank 10 during normal operation, the coolant is flown into the catch tank 10 and stored, and is not sucked into the combustion chamber 2a. Can be.

[Example 2]
The intake device 1 of the second embodiment will be described with reference to FIG. 3 focusing on differences from the first embodiment.
In the present embodiment, a catch tank 10 is disposed downstream of the throttle device 9.
That is, the catch tank 10, the throttle device 9, and the intercooler 8 are arranged in this order from the downstream side in the intake passage 4 of the present embodiment.

The catch tank 10 communicates with the vicinity of the lowermost portion 13a in the flow direction, and the throttle device 9 is disposed in the intake passage 4 between the lowermost portion 13a and the outlet 11a of the accommodating space 11.
Also by this, the same effect as Example 1 can be produced.

Example 3
The intake device 1 according to the third embodiment will be described with a focus on differences from the first embodiment with reference to FIG.
In the present embodiment, the intake pipe 5 in the vicinity of the opening 16c in the flow direction of the intake passage 4 has a recessed part 5b recessed downward on the inner peripheral surface of the lower pipe wall 5c.
That is, in the intake pipe 5 located in the vicinity of the opening 16c in the flow direction, a concave portion 5b that is recessed downward is formed on the inner peripheral surface of the pipe wall 5c located below. In the present embodiment, the recess 5b is formed by the tube wall 5c having a convex shape.

According to this, the oil transmitted through the intake pipe 5 near the lowermost part 13a of the intake passage 4 is guided and stored in the recess 5b.
For this reason, even if it is the same oil quantity, compared with Example 1, the oil level in the intake pipe 5 becomes low by the capacity | capacitance of the recessed part 5b.

Therefore, the position of the opening 16c can be set to a position lower than that of the first embodiment.
And since the position of the opening 16c can be made low, when cooling water leaks from the intercooler 8, the water level which can flow in into the catch tank 10 from the opening 16c can be made low. Thereby, the quantity of the cooling water which accumulates in the intake pipe 5 can be made small. It should be noted that the smaller the amount of cooling water accumulated in the intake pipe 5, the lower the risk of occurrence of problems such as water hammer.

[Modification]
The aspect of the intake device 1 is not limited to the embodiment, and various modifications can be considered.
For example, in the first to third embodiments, the catch tank 10 is connected to the downstream side of the intercooler 8. However, as shown in FIG. If there is a place where water easily collects, the catch tank 10 may be connected upstream of the intercooler 8.

  In addition, when the intake pipe 5 extends downwardly both upstream and downstream of the intercooler 8, there are places where cooling water tends to accumulate both upstream and downstream of the intercooler 8. In this case, the catch tank 10 is connected both upstream and downstream of the intercooler 8. In addition, two communication pipes 16 are provided in one catch tank 10, one of the communication pipes 16 is connected to a location where the cooling water on the upstream side of the intercooler 8 tends to accumulate, and the other communication pipe 16 is connected to the downstream side of the intercooler 8. You may connect to the location where the cooling water of the side tends to accumulate.

DESCRIPTION OF SYMBOLS 1 Intake device 2 Engine main body 2a Combustion chamber 4 Intake passage 5 Intake pipe 5a Bottom part 5b of intake pipe Recessed part 5c Tube wall 8 Intercooler 10 Catch tank 16 Communication pipe 16a Tip part 16c Opening (communication opening)

Claims (2)

An intake pipe that forms an intake passage through which intake air drawn into the combustion chamber of the engine flows;
An intercooler that is disposed in the intake passage and cools the intake air using cooling water;
A catch tank connected to the intake pipe and into which cooling water leaked from the intercooler flows,
The catch tank is connected to a place where the leaked coolant is most likely to accumulate in the intake passage.
When the direction of gravity is the downward direction, the communication inlet to the intake pipe of the catch tank is an engine intake device that opens above the lowermost part of the intake pipe,
The catch tank has the communication port at the tip and connected to the intake pipe to communicate the inside of the catch tank and the intake pipe.
The communication pipe is connected to the intake pipe so that the tip projects inward from the inner peripheral surface of the intake pipe,
The engine intake device according to claim 1, wherein a distal end portion (16a) of the communication pipe (16) is inclined downward with respect to a horizontal direction so that the distal end is downward . The engine intake device according to claim 1, wherein
The engine intake device according to claim 1, wherein the intake pipe in the vicinity of the communication port has a concave portion recessed downward on an inner peripheral surface of a lower pipe wall .

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