JP2015227641A - vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reliably discharge condensed water without largely securing a pressure difference between intake air and exhaust air.SOLUTION: An inter cooler 24 is provided at a point of an intake passage 14 at a downstream side rather than a compressor wheel of a supercharger 22, and cools supercharged intake air. A separator 26 has a condensed water tank 44 which is provided at a point of the intake passage 14 at a downstream side rather than the intercooler 24, separates condensed water from intake air which is cooled by the intercooler 24, and stores the separated condensed water. A float 52 which floats on a water level 2A of the stored condensed water 2, and ascends and descends following the water level 2A is provided in the condensed water tank 44, a suction port 2804 of a condensed water discharge passage 28 is provided at the float 52, air is sucked from the suction port 2804 together with the condensed water 2, and the air is introduced into the condensed water discharge passage 28 together with the condensed water 2.

Description

  TECHNICAL FIELD The present invention relates to a condensate drain device for a vehicle that discharges condensate accumulated downstream of a supercharger and an intercooler from an intake passage.

There is known an exhaust gas recirculation device that introduces a portion of exhaust gas exhausted from a vehicle engine into intake air (intake air) as low-pressure EGR gas, and sucks the exhaust gas again to reduce nitrogen oxides in the exhaust gas. ing.
When such an exhaust gas recirculation device is used, condensed water is generated by cooling the water vapor contained in the low-pressure EGR gas in the intercooler.
If such condensed water enters the cylinder of the engine together with the intake air, it becomes a factor such as a water hammer phenomenon, which is disadvantageous in increasing the durability of the engine.
Therefore, a separator that separates the intake air and the condensed water is provided downstream of the intercooler, and a condensed water discharge passage that discharges the condensed water stored in the separator to the exhaust passage is provided, and the condensed water stored in the separator is supplied to the intake and exhaust air. Is discharged to the exhaust passage using a negative pressure, that is, using negative pressure (see Patent Document 1).

JP 2002-303146 A

However, compared to the case where air and condensed water coexist in the condensed water discharge passage, the tube friction resistance increases when the condensed water discharge passage is filled with condensed water. In order to discharge toward the exhaust passage, it is necessary to ensure a large pressure difference between the intake air and the exhaust gas.
However, since the pressure difference between the intake air and the exhaust gas is determined by the operating state of the engine, the pressure difference has a limit.
The present invention has been made in view of the above circumstances, and an object thereof is to provide a vehicle that is advantageous in reliably discharging condensed water without ensuring a large pressure difference between intake and exhaust.

In order to achieve the above object, an invention according to claim 1 is provided in an intake passage of an internal combustion engine, and supercharger that supercharges intake air, an intercooler that cools the supercharged intake air, and the cooling A separator having a condensed water tank for storing condensed water separated from the intake air, and a condensed water discharge passage for discharging condensed water stored in the condensed water tank to the outside of the separator. In the condensed water tank, a float that floats on the surface of the stored condensed water is provided, and a suction port of the condensed water discharge path is provided in the float.
According to a second aspect of the present invention, the separator is positioned below the upper space part, an upper space part in which an inlet part for receiving the cooled intake air and an outlet part for discharging the intake air are arranged. And a lower space portion that constitutes the condensed water tank, and the suction port has the lower space where the upper space portion and the lower space portion do not overlap when the separator is viewed from above the vehicle. It is provided in the area of the part.
The invention according to claim 3 is characterized in that the separator is provided with a float type level gauge for detecting the height of the float floating on the surface of the stored condensed water.
The invention according to claim 4 is characterized in that an on-off valve for opening and closing the condensed water discharge passage is arranged at a higher position than the suction port.
The invention according to claim 5 is characterized in that the on-off valve is arranged on an upper surface of the separator.
The invention according to claim 6 is characterized in that an EGR means for returning the exhaust gas in the exhaust passage downstream of the supercharging means to the intake passage upstream of the supercharging means is provided. To do.

According to the first aspect of the present invention, the suction port of the condensed water discharge passage is provided in a float that floats on the surface of the stored condensed water, and air is sucked together with the condensed water from the suction port. It is introduced into the condensed water discharge passage.
Therefore, the condensed water discharge passage is not filled with condensed water, and air and condensed water coexist in the condensed water discharge passage. Therefore, the pipe friction resistance when discharging condensed water can be reduced, and the condensed water is discharged into the exhaust passage. Therefore, it is advantageous to surely discharge the condensed water without securing a large pressure difference between the intake air and the exhaust gas.
According to the second aspect of the present invention, the suction port is located at a location away from a location where the water surface of the condensed water is easily waved by the intake and exit from the inlet portion and the outlet portion, and air is supplied from the suction port together with the condensed water. Stable suction is possible, which is more advantageous for reliably discharging condensed water.
According to the invention of claim 3, since the float type level gauge for detecting the height of the water surface of the condensed water is provided by using the float, according to the amount of the condensed water detected by the float type level gauge. This is advantageous in accurately controlling the opening / closing operation of the on-off valve and the operation operation of the engine while suppressing an increase in the number of parts.
According to the invention described in claim 4, since the condensed water is discharged toward the exhaust passage, the condensed water can be reliably discharged without securing a large pressure difference between the intake air and the exhaust. The on-off valve that opens and closes can be disposed at a higher position than the suction port, which is advantageous in ensuring a large degree of freedom in the layout of the place where the on-off valve is installed.
According to the fifth aspect of the present invention, since the on-off valve is arranged on the upper surface of the separator, the upper surface of the separator can be used instead of the fixing portion without providing a new fixing portion, and fixing of the on-off valve is simple. It is advantageous in carrying out.
According to the sixth aspect of the present invention, more condensed water is generated more easily when the exhaust gas recirculated by the EGR means is cooled by the intercooler, and therefore more condensed water is stored in the condensed water tank. It is advantageous to surely discharge a larger amount of condensed water without securing a large pressure difference between the intake air and the exhaust gas.

It is explanatory drawing which shows the structure of the vehicle which concerns on this Embodiment. It is a side view explaining arrangement of an intercooler, a separator, and an engine. It is explanatory drawing which shows the internal structure of a separator. (A) is the A arrow view of FIG. 3, (B) is the B arrow view of (A). (A) is a front view of a separator, (B) is a B arrow view of (A), (C) is a C arrow view of (A).

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
As shown in FIG. 1, the vehicle 10 includes an engine 12, an intake passage 14, an exhaust passage 16, a high pressure throttle valve 18, a low pressure throttle valve 20, a supercharger 22, an intercooler 24, and a separator 26. A condensate discharge passage 28, an on-off valve 30, a first catalyst device 32, a second catalyst device 34, a high pressure EGR device 36, and a low pressure EGR device 38.

In the present embodiment, the engine 12 is a diesel engine, and reference numeral 1202 in the figure denotes an injector that injects fuel into the combustion chamber of the engine 12, and 1204 denotes a fuel injection pump that supplies fuel to the injector.
The engine 12 is provided with a gas sensor (not shown) that detects the oxygen concentration and NOx concentration in the exhaust gas.
Needless to say, the engine 12 is not limited to a diesel engine, and may be a gasoline engine.

The intake passage 14 guides the intake air introduced through the air cleaner 13 to the combustion chamber of the engine 12.
The low-pressure throttle valve 20 is provided at a location of the intake passage 14 on the downstream side of the air cleaner 13 and adjusts the intake air amount.

The supercharger 22 supercharges intake air into the intake passage 14. The supercharger 22 is provided in a compressor wheel (not shown) provided at a location of the intake passage 14 on the downstream side of the low pressure throttle valve 20 and the exhaust passage 16. And a turbine wheel (not shown).
When the turbine wheel is rotated by the exhaust gas flowing through the exhaust passage 16, the compressor wheel is rotated, whereby the intake air is compressed and supercharged to the intake passage 14.
In the present embodiment, a description will be given of a case where the supercharger 22 supercharges air supply using the energy of exhaust gas. However, the supercharger 22 is not limited to the present embodiment, and for example, an engine 12 or a supercharger that supercharges intake air using the driving force of a motor.

The intercooler 24 is provided at a location of the intake passage 14 on the downstream side of the compressor wheel of the supercharger 22 and cools the supercharged intake air.
The separator 26 is provided at a location of the intake passage 14 on the downstream side of the intercooler 24, and separates condensed water from the intake air cooled by the intercooler 24 and stores the separated condensed water (see FIG. 3). )have. The separator 26 will be described in detail later.

The condensed water discharge passage 28 discharges the condensed water stored in the condensed water tank to the exhaust passage 16 using the pressure difference between the intake passage 14 and the exhaust passage 16. It is provided so that condensed water may be discharged to the location of the exhaust passage 16 downstream of the two-catalyst device 34. Here, the discharge side of the condensed water discharge passage 28 is not necessarily provided downstream of the second catalyst device 34, and the discharge side of the condensed water discharge passage 28 is connected upstream of the second catalyst device 34. May be. Further, the discharge side of the condensed water discharge passage 28 may be separately connected to a purification device for purifying condensed water and an evaporation device for evaporating condensed water.
The on-off valve 30 opens and closes the condensed water discharge passage 28.

The high-pressure throttle valve 18 is provided at a location of the intake passage 14 on the downstream side of the separator 26 and adjusts the intake air amount.
The exhaust passage 16 guides the exhaust discharged from the combustion chamber of the engine 12 to the outside of the vehicle.

The first catalyst device 32 is provided at a location of the exhaust passage 16 downstream of the compressor wheel of the supercharger 22, and the second catalyst device 34 is a location of the exhaust passage 16 downstream of the first catalyst device 32. Is provided.
The 1st catalyst apparatus 32 and the 2nd catalyst apparatus 34 are comprised by conventionally well-known catalysts, such as an oxidation catalyst, DPF, and a selective reduction catalyst.

The high-pressure EGR device 36 includes a high-pressure EGR pipe 3602 that connects a location of the exhaust passage 16 upstream of the supercharger 22 and a location of the intake passage 14 downstream of the high-pressure throttle valve 18, and a high-pressure EGR pipe 3602. A high-pressure EGR cooler 3604 provided, and a high-pressure EGR valve 3606 provided at a connection point between the high-pressure EGR pipe 3602 and the intake passage 14 are provided.
When the high pressure EGR valve 3606 is opened, a part of the exhaust gas flowing through the exhaust passage 16 upstream of the supercharger 22 is introduced into the high pressure EGR cooler 3604 and cooled by the high pressure EGR cooler 3604 and more than the high pressure throttle valve 18. It is returned to the intake passage 14 on the downstream side.

The low-pressure EGR device 38 includes an exhaust passage 16 downstream of the supercharger 22 (an exhaust passage 16 downstream of the first catalyst device 32) and an intake passage 14 upstream of the supercharger 22. A low-pressure EGR pipe 3802 that connects (the location of the intake passage 14 downstream of the low-pressure throttle valve 20), a low-pressure EGR cooler 3804 provided in the low-pressure EGR pipe 3802, and the low-pressure EGR pipe 3802 and the intake passage 14 And a low pressure EGR valve 3806 provided at the connection location.
When the low pressure EGR valve 3806 is opened, a part of the exhaust gas flowing through the exhaust passage 16 on the downstream side of the supercharger 22 is introduced into the low pressure EGR cooler 3804 and is cooled by the low pressure EGR cooler 3804 and more than the supercharger 22. The refrigerant is returned to the upstream intake passage 14.
In the present embodiment, the low pressure EGR device 38 constitutes a low pressure EGR means.

Next, the separator 26 will be described in detail with reference to FIGS.
As shown in FIGS. 3 and 5 (A) to (C), the separator 26 has a tank body 40.
An upper space portion 42 and a lower space portion 44 located below the upper space portion 42 are provided inside the tank body 40, and the lower space portion 44 constitutes a condensed water tank 44.
As shown in FIG. 5B, the lower space 44 has a horizontally long shape when the separator 26 is viewed from above the vehicle, and the upper space 42 is one end in the longitudinal direction of the lower space 44. Is located.
In the upper space portion 42, a downstream end opening 1402 of the intake passage 14 connected to the intercooler 24 and an upstream end opening 1404 of the intake passage 14 connected to the high pressure throttle valve 18 are arranged.
The downstream end opening 1402 constitutes an inlet portion 46 through which intake air including cooled condensed water is sucked, and the upstream end opening 1404 constitutes an outlet portion 48 through which intake air separated from condensed water is discharged.
Then, when the intake air is moved from the inlet 46 to the outlet 48 in the upper space, the condensed water 2 is separated from the intake air and stored in the condensed water tank 44.
Further, as shown in FIG. 5A, a suppression plate 50 is provided between the lower part of the upper space part 42 and the upper part of the lower space part 44, and the condensed water 2 stored in the condensed water tank 44 is the outlet part. 48 so as not to be led to 48.

As shown in FIGS. 3, 4A, and 4B, the condensed water tank 44 is provided with a float 52 that floats on the water surface 2A of the stored condensed water 2 and moves up and down following the water surface 2A. .
When the separator 26 is viewed from above the vehicle, the float 52 is located at a location of the condensed water tank 44 away from the upper space portion 42, that is, when the separator 26 is viewed from above the vehicle, the upper space portion 42 and the lower space It is provided in the lower space part of the region where the space part 44 does not overlap.

In the present embodiment, the float 52 constitutes a float of a float type level gauge 54 that detects the height of the water surface 2A of the condensed water 2. That is, a float type level gauge 54 is provided using the float 52.
The float 52 has an annular shape, and a central hole portion 5202 is inserted through an axial stem 56 extending in the vertical direction. The float 52 is configured to be movable up and down along the stem 56.
A magnet (not shown) is provided inside the float 52, and a plurality of reed switches (not shown) are provided on the stem 56 at predetermined intervals in the length direction.
Therefore, when the float 52 moves up and down following the water surface 2A, among the plurality of reed switches, a reed switch provided at a position corresponding to the position of the float 52 is turned on. The height of the water surface 2A of the condensed water 2 is detected.
Such a float type level gauge 54 uses a magnet provided in the float 52 and a reed switch provided in the stem 56 as in the present embodiment, and also uses a laser detection light to position the float 52 that moves up and down. It may be configured using a position sensor that detects the position, or may be configured using a limit switch that turns on and off by contacting the float 52 that moves up and down, and various conventionally known float type level gauges are used. Is possible.

In the present embodiment, as shown in FIGS. 3, 4 (A), and (B), the condensed water discharge passage 28 includes a flexible hose 2802 disposed inside the condensed water tank 44, The front end opening of the hose 2802 is a suction port 2804 of the condensed water discharge passage 28.
The tip of the hose 2802 is attached to the float 52, and the suction port 2804 is arranged such that a half of the suction port 2804 is located in the condensed water 2 and the other half is located in the air. Moves up and down with the float 52 following the water surface 2A of the stored condensed water 2.
Accordingly, the suction port 2804 is configured such that air is sucked together with the condensed water 2 due to a pressure difference between the intake air in the intake passage 14 and the exhaust gas in the exhaust passage 16.
The on-off valve 30 is disposed on the upper portion of the tank body 40, that is, on the upper surface of the separator 26. Thereby, the upper surface of the separator 26 can be used in place of the fixing portion without providing a new fixing portion, which is advantageous for easily fixing the on-off valve 30.

According to the present embodiment, the condensed water tank 44 is provided with the float 52 that floats on the water surface 2A of the stored condensed water 2 and moves up and down following the height of the water surface 2A. A suction port 2804 of the passage 28 is provided, air is sucked together with the condensed water 2 from the suction port 2804, and air is introduced into the condensed water discharge passage 28 together with the condensed water 2.
Therefore, since the condensed water discharge passage 28 is not filled with the condensed water 2 and air and condensed water 2 are mixed in the condensed water discharge passage 28, the pipe friction resistance at the time of discharging the condensed water 2 can be reduced. Since the condensed water 2 is discharged toward the exhaust passage 16, it is advantageous to surely discharge the condensed water 2 without securing a large pressure difference between the intake air and the exhaust gas.

  Further, according to the present embodiment, the suction port 2804 is provided at a location of the lower space portion 44 that is separated from the upper space portion 42 when viewed in plan. Accordingly, the suction port 2804 is located at a location away from the location where the water surface 2A of the condensed water 2 is likely to wave due to the intake and exit from the inlet portion 46 and the outlet portion 48, and stabilizes the air together with the condensed water 2 from the suction port 2804. This is more advantageous for reliably discharging the condensed water 2.

In addition, according to the present embodiment, since the float type level gauge 54 that detects the height of the water surface 2A of the condensed water 2 is provided using the float 52, the condensed water 2 is suppressed while suppressing an increase in the number of parts. The height of the water surface 2A, that is, the amount of the condensed water 2 can be detected.
Therefore, it is advantageous in accurately controlling the opening / closing operation of the on-off valve 30, the operation operation of the engine 12, and the low-pressure EGR device 38 according to the detected amount of condensed water 2.
For example, when the amount of the condensed water 2 stored in the condensed water tank 44 is equal to or greater than a predetermined threshold, the on-off valve 30 is opened and the intake air and the exhaust air sufficient to discharge the condensed water 2 are exhausted. By controlling the engine 12 so as to generate a pressure difference with the above, it is advantageous in accurately discharging the condensed water 2.
Further, since the outside air humidity is extremely high, a large amount of water is contained in the intake air, and even if the condensed water 2 is discharged by controlling the engine 12 as described above, the condensed water 2 stored in the condensed water tank 44. It is conceivable that the amount of is not below a threshold value.
In this case, by restricting or closing the low pressure EGR valve 3806 of the low pressure EGR device 38, the exhaust gas recirculated to the intake air is suppressed, thereby suppressing the generation of the condensed water 2 and the on-off valve 30. The engine 12 is controlled so as to generate a pressure difference between the intake air and the exhaust gas that is sufficient to discharge the condensed water 2 while being opened, which is advantageous in accurately discharging the condensed water 2.
That is, since the opening / closing operation of the opening / closing valve 30, the operation operation of the engine 12, and the control of the low pressure EGR device 38 can be accurately controlled according to the amount of the condensed water 2, This is advantageous in avoiding the problem that the on-off valve 30 is not opened despite the fact that a large amount of the condensed water 2 is accumulated.

  Further, in the present embodiment, since the condensed water 2 is discharged toward the exhaust passage 16, the condensed water 2 can be discharged reliably without securing a large pressure difference between the intake air and the exhaust gas. The on-off valve 30 that opens and closes the passage 28 can be disposed at a higher position than the suction port 2804, which is advantageous in securing a large degree of freedom in the layout of the place where the on-off valve 30 is installed.

In the present embodiment, low-pressure EGR means for returning the exhaust gas in the exhaust passage 16 downstream of the supercharger 22 to the intake passage 14 upstream of the supercharger 22 is provided.
Therefore, since the exhaust gas is recirculated to the intake passage 14 upstream of the intercooler 24, more condensed water 2 generated by being cooled by the intercooler 24 is more likely to be generated. Therefore, more condensed water 2 is generated in the condensed water tank 44. However, according to the present embodiment, it is advantageous to surely discharge more stored condensed water 2 without securing a large pressure difference between the intake air and the exhaust gas.

Various configurations of the suction port 2804 are conceivable, and the suction port 2804 may have a structure in which air is sucked together with the condensed water 2.
Further, the shape of the float 52 is not limited to the embodiment, and various conventionally known structures can be employed.
Further, the portion of the condensed water discharge passage 28 disposed inside the condensed water tank 44 is not limited to the flexible hose 2802. For example, the portion is flexible so that the suction port 2804 moves up and down following the float 52. For example, a plurality of pipes having no property may be connected to bendable.
In this embodiment, the case where the low pressure EGR device 38 and the high pressure EGR device 36 are provided has been described. However, one or both of the low pressure EGR device 38 and the high pressure EGR device 36 are not provided. However, the present invention is naturally applicable.

2 Condensed water 2A Water surface 10 Vehicle 12 Engine 14 Intake passage 16 Exhaust passage 22 Supercharger 24 Intercooler 26 Separator 28 Condensate discharge passage 30 On-off valve 38 Low pressure EGR device 42 Upper space portion 44 Lower space portion (Condensate water tank)
46 Inlet part 48 Outlet part 52 Float 54 Float type level gauge

Claims (6)

A supercharger that is arranged in the intake passage of the internal combustion engine and supercharges intake air;
An intercooler for cooling the supercharged intake air;
A separator having a condensed water tank for storing condensed water separated from the cooled intake air;
A condensed water discharge passage for discharging condensed water stored in the condensed water tank to the outside of the separator;
A vehicle comprising:
A float that floats on the surface of the stored condensed water is provided inside the condensed water tank,
A suction port of the condensed water discharge passage is provided in the float;
A vehicle characterized by that. The separator constitutes the condensed water tank located below the upper space portion, an upper space portion in which an inlet portion for receiving the cooled intake air and an outlet portion for discharging the intake air are arranged. A lower space portion,
The suction port is provided in a region of the lower space where the upper space and the lower space do not overlap when the separator is viewed from above the vehicle.
The vehicle according to claim 1. The separator is provided with a float type level gauge for detecting the height of the float floating on the surface of the stored condensed water.
The vehicle according to claim 1 or 2, characterized by the above. An on-off valve for opening and closing the condensed water discharge passage is disposed at a higher position than the suction port,
The vehicle according to any one of claims 1 to 3, wherein the vehicle is a vehicle. The on-off valve is disposed on an upper surface of the separator;
The vehicle according to claim 4. EGR means for returning the exhaust gas in the exhaust passage downstream from the supercharging means to the intake passage upstream from the supercharging means is provided.
The vehicle according to any one of claims 1 to 5, wherein the vehicle is a vehicle.

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