JP2015169124A - Fuel evaporative emission treatment apparatus of engine equipped with turbocharger - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fuel evaporative emission treatment apparatus of an engine equipped with a turbocharger, capable of preventing the clogging of an ejector caused by blow-by gas and simplifying a passage from a boost pressure introduction portion of the ejector to an outlet of the ejector.SOLUTION: Ducts 11 and 13 upstream and downstream of a compressor 22 of a turbocharger 12, respectively are provided generally in parallel, the fuel evaporative emission treatment apparatus includes an ejector 50 that includes a fuel evaporative emission inlet port 50a and a boost pressure introduction portion 50b, the boost pressure introduction portion 50b is connected to an upper side of the duct 13 between downstream of the compressor 22 and upstream of an intercooler, and an outlet port 50c of the ejector 50 is connected to a lower side of the duct 11 upstream of the compressor 22.

Description

  The present invention relates to an evaporative fuel processing apparatus for a supercharged engine that purges evaporative fuel (evaporative gas) generated in a fuel tank into an intake system of the supercharged engine.

In an apparatus having an internal combustion engine, such as an automobile, the fuel tank may be warmed by heat generated by the internal combustion engine, and the fuel may vaporize and expand in the tank.
In the past, such evaporated fuel (evaporative gas) has escaped into the atmosphere, but since it causes air pollution, its release into the atmosphere has been limited in recent years due to environmental regulations.

  In general, such evaporated fuel is adsorbed and stored in a canister, and then mixed with intake air and sent to a combustion chamber for combustion. When evaporating fuel is allowed to flow from the canister into the intake passage, it is known to use an ejector having a venturi mechanism to suck the evaporated fuel from the canister and eject it into the intake passage.

  Patent Document 1 discloses an evaporative fuel processing device for an engine with a supercharger. This disclosed in Patent Document 1 is provided with a supercharging pressure introduction unit that introduces supercharging pressure into an ejector. A discharge port that is provided downstream of the compressor and ejects evaporated fuel into the intake passage is provided upstream of the compressor. In the ejector pump section, the air flow of the ejector is caused by the differential pressure between the boost pressure introduction side and the discharge port side. The air flow generated in the passage is throttled to generate a negative pressure, and the fuel vapor is introduced into the air flow path of the ejector by this negative pressure, so that the fuel vapor is introduced from the upstream side of the compressor together with this air flow. It has become so.

  According to this conventional structure, there is an advantage that fuel vapor in an engine with a supercharger can be processed by a simple configuration that does not require an actuator such as an electric motor or a power source such as an engine output.

However, in the conventional structure disclosed in Patent Document 1, since there is an inflow portion of blowby gas (a mixture of engine oil and unburned gas) upstream of the compressor of the turbocharger, the blowby gas is cooled. There is a problem that the ejected oil is sucked into the ejector from the supercharging pressure introducing portion located downstream of the compressor of the turbocharger, and the ejector is clogged.
In addition, in order to save space in the engine room, it is required to simplify the circuit to the pressure introduction part and the ejector outlet part of the ejector.

JP 2007-332855 A

  Therefore, the present invention provides an evaporative fuel processing device for an engine with a supercharger that can prevent clogging of an ejector due to blow-by gas and can simplify a passage to a supercharging pressure introduction portion and an ejector outlet portion of the ejector. For the purpose of provision.

  An evaporated fuel processing apparatus for an engine with a supercharger according to the present invention is an evaporated fuel processing apparatus for an engine with a supercharger that purges the evaporated fuel generated in a fuel tank into the engine with a supercharger. And the evaporative fuel treatment apparatus has an ejector including an evaporative fuel suction portion and a supercharging pressure introduction portion, and the supercharging pressure introduction portion is connected to the compressor downstream and the intercooler. It is connected to the upper side of the duct between the upstream side and the outlet of the ejector is connected to the lower side of the duct upstream of the compressor.

The above configuration has the following effects.
That is, when the blow-by gas is cooled and becomes oily, it is predicted that the blow-by gas moves along the lower side of the duct, so the supercharging pressure introduction part of the ejector is placed on the upper side of the duct between the compressor downstream and the intercooler upstream. By connecting, it is possible to prevent the above-described oil from being sucked into the ejector from the supercharging pressure introducing portion and causing the ejector to be clogged.
In addition, since the ducts upstream and downstream of the compressor of the turbocharger are provided substantially in parallel and the ejector is disposed between the substantially parallel ducts, the passage between the supercharging pressure introduction part and the ejector outlet part of the ejector can be simplified. Can be planned.
In addition, since the supercharging pressure (intake air) is introduced from the upstream side of the intercooler to the ejector, the influence on the engine output is small.

  In one embodiment of the present invention, the blow-by gas inflow portion is located downstream of the ejector and upstream of the compressor.

  According to the above configuration, since the blow-by gas inflow portion is provided on the downstream side of the ejector and the upstream side of the compressor, the blow-by gas can easily flow into the upstream side of the compressor, and the blow-by gas in which the blow-by gas does not directly flow into the ejector outlet portion. Since it can be provided further upstream of the inflow part, the ejector outlet part can be connected to the lower side of the duct, and the passage to the supercharging pressure introduction part and the ejector outlet part of the ejector can be further simplified. .

  In one embodiment of the present invention, the connecting portion between the supercharging pressure introducing portion of the ejector and the duct downstream of the compressor is arranged so that the connecting portion and the flow direction of the compressed intake air by the compressor are opposite to each other. The angle formed with the distribution direction is set to an acute angle.

According to the above configuration, since the angle formed between the direction in which the compressed intake air flows in the duct downstream of the compressor and the connection portion is set to an acute angle, the connection portion or the supercharging pressure of the oil mist in which the blowby gas is cooled and liquefied Inflow to the introduction part can be further suppressed.
Therefore, the ejector can be prevented from being clogged even better.

  In one embodiment of the present invention, the connection portion between the duct upstream of the compressor and the ejector outlet portion has an angle formed between the connection portion and the intake flow direction so that the intake flow direction is the same direction. It is set at an acute angle.

  According to the above configuration, since the angle formed between the direction in which the intake air flows in the duct upstream of the compressor and the connection portion is set to an acute angle, the evaporated fuel generated in the fuel tank easily flows into the compressor upstream duct. .

  According to the present invention, it is possible to prevent the ejector from being clogged by blow-by gas and to simplify the passage to the supercharging pressure introduction portion and the ejector outlet portion of the ejector.

System diagram showing an evaporative fuel treatment device for a supercharged engine of the present invention Perspective view of the main part of the evaporative fuel treatment device Side view of FIG. Sectional view showing the internal structure of the ejector

  Purging the engine with a supercharger with evaporated fuel generated in the fuel tank for the purpose of preventing clogging of the ejector by blow-by gas and simplifying the passage to the supercharging pressure introduction part and the ejector outlet part of the ejector In the evaporative fuel processing device for an engine with a supercharger, the ducts upstream and downstream of the compressor of the supercharger are provided substantially in parallel, and the evaporative fuel processing device includes an evaporative fuel suction portion and a supercharging pressure introduction portion. The supercharging pressure introducing part is connected to the upper duct side between the compressor downstream and the intercooler upstream, and the outlet part of the ejector is connected to the lower duct side upstream of the compressor.

An embodiment of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a system diagram, FIG. 2 is a perspective view of a main part of the evaporated fuel processing device, FIG. 3 is a side view of FIG. 2, and FIG. 4 is an inside of an ejector. It is sectional drawing which shows a structure.

In FIG. 1, the engine with a supercharger includes an intake system A, a fuel supply system B, and an evaporative fuel processing device C.
The intake system A described above supplies air to the engine 1, and includes an air cleaner 10, a compressor upstream duct 11, a turbocharger 12, a compressor downstream duct 13, an intercooler 14, an intercooler downstream passage 15, a throttle body 16, and a surge tank. 17 and an intake manifold 18 are provided.

  The air cleaner 10 is an air purification device that filters air taken in from an intake inlet 19 through an element 20 provided in an air cleaner case, removes foreign matters such as dust, and supplies purified air to the intake outlet 21 from downstream of the element 20. .

  The compressor upstream duct 11 is a duct that supplies purified air that flows out from the intake outlet 21 of the air cleaner 10 to an intake inlet 22 a upstream of the compressor 22 of the turbocharger 12.

  The turbocharger 12 is a supercharger that compresses and pressurizes intake air by using exhaust energy of the engine 1, and includes a turbine 23 and a compressor 22.

  The turbine 23 is a turbo exhaust turbine having an impeller that is rotationally driven by the pressure of exhaust gas supplied to the turbine housing 26 via the exhaust port 2, the exhaust manifold 24, and the exhaust passage 25 of the engine 1.

The compressor 22 is connected to an impeller on the turbine 23 side through a rotating shaft, and is a turbo compressor driven by the turbine 23. The compressor 23 is connected to the intake inlet from the compressor upstream duct 11. The air introduced into 22a is compressed to a predetermined supercharging pressure and discharged to the compressor downstream duct 13 from the intake outlet 22b.
The compressor downstream duct 13 is a conduit for introducing the air discharged from the compressor 22 of the turbocharger 12 into the intercooler 14.

  The intercooler 14 is a heat exchanger that cools air whose temperature has increased during compression in the compressor 22 with traveling wind or the like, thereby increasing the oxygen density and increasing the charging efficiency of the intake air.

The intercooler downstream passage 15 is a conduit for introducing the cooled air that has flowed out of the intercooler 14 into the throttle body 16 and the surge tank 17.
The throttle body 16 is provided with a throttle valve 16V, and the output of the engine 1 is adjusted by adjusting the opening of the throttle valve 16V.

  The intake manifold 18 is a branch pipe that distributes the air that has passed through the throttle body 16 and the surge tank 17 to the intake ports 3 corresponding to the number of cylinders of the engine 1.

The fuel supply system B supplies fuel such as gasoline to the engine 1 and includes a fuel tank 30, a fuel pump (not shown), a fuel supply passage 31, and an injector 32.
The fuel tank 30 is a container for storing fuel such as liquid phase gasoline.
The fuel pump (not shown) pressurizes the fuel in the fuel tank 30 to a predetermined fuel pressure and discharges it to the fuel supply passage 31.

  The injector 32 is a fuel injection valve disposed at a portion corresponding to each intake port 3 of the intake manifold 18 and intermittently injects fuel into the intake port 3 in accordance with a predetermined fuel injection timing.

  The evaporative fuel processing device C processes evaporative fuel (evaporation) generated by evaporating the fuel in the fuel tank 30, and canister 40, charge passage 41, outside air introduction line 42, purge passage 43, negative pressure An area purge passage 44, a supercharging area purge passage 45, and an ejector 50 are provided.

  The canister 40 is a case in which activated carbon having a function of temporarily adsorbing and storing evaporated fuel and then releasing it is accommodated in a case.

  The charge passage 41 is a conduit for introducing the evaporated fuel discharged from the fuel tank 30 into the canister 40.

  The outside air introduction line 42 is a pipe line that introduces air functioning as a purge gas for carrying the evaporated fuel into the canister 40 when the evaporated fuel stored in the canister 40 is discharged and sent to the engine side.

  A purge valve 46 is provided in the purge passage 43. The purge passage 43 is a pipe that conveys the evaporated fuel released by the canister 40 to the engine side together with the air taken in from the outside air introduction line 42 when the purge valve 46 is opened. This purge passage 43 is branched at a branching point 47 into a negative pressure region purge passage 44 and a supercharging region purge passage 45.

  The negative pressure region purge passage 44 has an upstream end connected to a branch point 47 and a downstream end connected between the throttle body 16 and the surge tank 17, and uses the intake negative pressure to supply evaporated fuel. Supply to intake port 3. A check valve 48 is interposed in the negative pressure region purge passage 44 described above.

The supercharging area purge passage 45 has an upstream end connected to the branch point 47 and a downstream end connected to the evaporated fuel suction portion 50a of the ejector 50, and uses the negative pressure generated by the internal structure of the ejector 50. Thus, the fuel vapor is supplied from the ejector 50 and the compressor 22 of the turbocharger 12 to the compressor downstream duct 13. Further, a check valve 49 is interposed in the above-described supercharging region purge passage 45.
The above-described ejector 50 is a fluid pump for evaporative fuel. A part of the intake air (supercharging pressure) pressurized by the compressor 22 of the turbocharger 12 is caused to flow inside, and a part of the intake air is supplied to the turbocharger 12. The fuel is discharged to the upstream side of the compressor 22 and the evaporated fuel is sucked by the negative pressure formed when the supercharging pressure flows through the inside.

  As shown in FIG. 4, the above-described ejector 50 includes an evaporated fuel suction part 50a, a supercharging pressure introduction part 50b, an outlet part 50c, a nozzle part 51, and a diffuser part 52 (diffuser, reduced pressure diffusion part). I have.

The nozzle portion 51 has a supercharging pressure introduction portion 50b at the upstream end thereof, and is a flow path that forms a throttle portion for the inflowing intake air, with the downstream end extending toward the outlet portion 50c. Yes.
The inner diameter of the nozzle portion 51 is formed so as to gradually decrease toward the tip (downstream end). The nozzle portion 51 increases the flow velocity of the intake air that has flowed in from the supercharging pressure introduction portion 50b due to a throttling effect. Thereby, in the front end side of the nozzle part 51, the area | region where intake air flows out at high speed becomes a negative pressure.

The diffuser part 52 is a flow path that gradually expands the inner diameter on the downstream side of the nozzle part 51 and the evaporated fuel suction part 50a and extends toward the outlet part 50c, and the upstream side is connected to the nozzle part 51 and the evaporated fuel suction part 50a. Has been.
And this diffuser part 52 reduces a pressure loss, reducing the flow velocity of the intake and evaporative fuel which distribute | circulates an inside.

  In this embodiment, it has a pipe 53 that forms the above-described evaporated fuel suction portion 50a, a pipe 54 that has a nozzle portion 51 disposed therein, and a pipe 55 that integrally forms a diffuser portion 52 therein. Two pipes 54 and 55 among the pipes 53 to 55 are arranged in a straight line, and the other pipe 53 is connected to the straight pipes 54 and 55 at a substantially right angle, so that the entire ejector 50 is substantially T. It is configured to have a letter shape. However, the diffuser portion may not be provided.

As shown in FIGS. 2 and 3, the ducts 11 and 13 upstream and downstream of the compressor 22 in the turbocharger 12 as a supercharger are provided substantially parallel to each other.
That is, the compressor upstream duct 11 and the compressor downstream duct 13 are such that the upstream duct 11 is located on the upper side, the downstream duct 13 is located on the lower side, and these ducts 11 and 13 are substantially parallel to each other. It is arranged like this.

  The compressor upstream duct 11 is formed by joining two half-structured resin pipes, 11a is a flange for joining two half-structured resin pipes, and 11b is the compressor upstream duct 11 connected to the engine. This is a mounting seat for fastening to one cylinder head via a bracket.

  The compressor downstream duct 13 is formed to be longer than the compressor upstream duct 11, and is formed by joining two resin pipes having a half structure, and 13a is joining two resin pipes having a half structure. 13b is a mounting seat for fastening the compressor downstream duct 13 to the transmission case via a bracket (not shown).

  The above-described ejector 50 is provided between the compressor upstream duct 11 and the compressor downstream duct 13, and the outlet portion 50 c of the ejector 50 is a pipe jacket portion that fits into the pipe 55 from the outside in a half-structured resin pipe. The outlet 50c of the ejector 50 is connected to the lower side of the compressor upstream duct 11.

In addition, a rubber connection pipe 57 is connected to the outer periphery of the supercharging pressure introduction section 50b and the pipe 54 in the ejector 50 by using a clamp 56, and the upstream end of the connection pipe 57 is connected to another clamp. 58 is connected to the upper side of the compressor downstream duct 13 between the compressor 22 downstream and the intercooler 14 upstream.
Specifically, the upstream side connection portion 57a of the connection pipe 57 is connected in communication with a joint portion 13c extending upward from the upper side of the bent portion of the half-structured resin pipe.

  In this way, the supercharging pressure introducing portion 50b of the ejector 50 is connected to the upper side of the compressor downstream duct 13 so as to prevent the ejector 50 from being clogged. That is, since the blow-by gas, which will be described later, is cooled to become oily (oil mist) is expected to move along the lower side (that is, the bottom) of the compressor downstream duct 13, the introduction of the supercharging pressure of the ejector 50 is introduced. By connecting the portion 50b to the upper side of the compressor downstream duct 13 between the downstream side of the compressor 22 and the upstream side of the intercooler 14, the oil mist described above is sucked into the ejector 50 from the supercharging pressure introduction portion 50b. It is configured to prevent clogging.

  Further, the ducts 11 and 13 upstream and downstream of the compressor of the turbocharger 12 are provided substantially in parallel, and the ejector 50 is disposed between the substantially parallel ducts 11 and 13 so that the supercharging pressure introduction portion 50b of the ejector 50 is provided. And the passage to the ejector outlet 50c, specifically, the upstream end of the connection pipe 57 and the passage to the ejector outlet 50c are simplified.

  Further, as shown in FIG. 3, the connecting portion 57a between the supercharging pressure introducing portion 50b of the ejector 50 and the compressor downstream duct 13 is in the flow direction of the compressed intake air by the connecting portion 57a and the joint portion 13c and the compressor 22 (FIG. 3). The angle θ1 formed with the flow direction of the compressed intake air (the direction of the arrow α) is set to an acute angle so that the direction is opposite to the direction of the arrow α of FIG.

In this embodiment, the angle θ1 is set in the range of 35 degrees to 45 degrees, but the angle θ1 may be an acute angle and is not limited to the numerical range.
The angle θ1 is set to an acute angle, and the flow direction of the compressed intake air led out from the joint portion 13c and the connecting portion 57a is opposite to the flow direction of the compressed intake air flowing in the compressor downstream duct 13 (arrow α direction). In this direction, the flow of the oil mist in which the blow-by gas is cooled and liquefied into the connecting portion 57a to the supercharging pressure introducing portion 50b is further suppressed.

  Furthermore, the connecting direction of the compressor upstream duct 11 and the outlet 50c of the ejector 50, specifically, the pipe 55 having the outlet 50c on the downstream side, and the directing direction of the jacket 11c are The angle θ2 formed by the intake flow direction (arrow β direction) is set to an acute angle so that the connection portion and the intake flow direction (see arrow β direction in FIG. 3) are in the same direction.

  In this embodiment, the angle θ2 is set in a range of 20 degrees to 30 degrees, but the angle θ2 may be an acute angle and is not limited to the numerical range.

  As described above, the angle formed by the direction in which the pipe 55 and the jacket portion 11c are directed and the direction in which the intake air flows in the compressor upstream duct 11 (arrow β direction) is set to an acute angle, thereby generating in the fuel tank 30. The evaporative fuel is configured to easily flow into the compressor upstream duct 11.

Incidentally, as shown in FIG. 1, a blow-by gas passage 60 is provided for returning blow-by gas (a mixture of engine oil and unburned gas) to the intake system.
The upstream end of the blow-by gas passage 60 is open to the cylinder head cover, and the downstream end is connected to the blow-by gas inflow portion 61. The blow-by gas inflow portion 61 is formed on the downstream side of the ejector 50 and on the upstream side of the compressor 22. Specifically, the blow-by gas inflow portion 61 is formed between the compressor inlet air inlet 22a and the compressor impeller storage space.

  In this embodiment, the cylinder part 61a extending upward in the vertical direction is formed integrally with the compressor housing, whereby the blow-by gas inflow part 61 is constituted by the cylinder part 61a.

  In this way, by providing the blow-by gas inflow portion 61 on the downstream side of the ejector 50 and on the upstream side of the compressor 22, the blow-by gas can easily flow into the upstream of the compressor 22, and the ejector outlet portion 50c is The blow-by gas can be provided further upstream than the blow-by gas inflow portion 61 where the blow-by gas does not directly flow, and the outlet 50c of the ejector 50 is connected to the lower side of the compressor upstream duct 11 that is not affected by the oil mist, The passage to the supercharging pressure introduction part 50b and the ejector outlet part 50c of the ejector 50, specifically, the passage to the upstream end of the connection pipe 57 and the ejector outlet part 50c is further simplified.

The operation of the evaporated fuel processing apparatus for an engine with a supercharger configured as described above will be described below.
The evaporative fuel processing apparatus C performs a normal purge when the turbocharger 12 is not operated and a supercharging purge when the turbocharger 12 is operated.

[Normal purge]
When the turbocharger 12 is not operating when the vehicle is running, if the purge valve 46 is controlled to open, the negative pressure in the intake manifold 18 generated by the intake stroke of the piston and the canister 40 are urged. The evaporated fuel adsorbed in the canister 40 due to the difference from the atmospheric pressure is supplied to the intake manifold 18 via the purge passage 43, purge valve 46, branch point 47, check valve 48, negative pressure region purge passage 44, and surge tank 17. Sucked in.
The evaporated fuel sucked into the intake manifold 18 is mixed with the original combustion fuel supplied from the injector 32 to the engine 1 and burned in the cylinder of the engine 1.

[Purge at supercharging]
When the turbocharger 12 is operating when the vehicle is running, the intake manifold 18 becomes positive pressure due to the pressurized intake air, making it difficult to suck the evaporated fuel as described above.
In the supercharging purge, a part of the intake air supercharged by the compressor 22 of the turbocharger 12 flows through the ejector 50 from the connection pipe 57 and returns from the compressor upstream duct 11 to the upstream side of the compressor 22.
At this time, when the purge valve 46 is controlled to open, the evaporated fuel adsorbed by the canister 40 due to the suction action of the evaporated fuel suction portion 50a of the ejector 50 is replaced with the purge passage 43, purge valve 46, branch point 47, check valve. 49, the fuel is sucked into the ejector 50 from the evaporated fuel suction portion 50a via the supercharging area purge passage 45, and is supplied to the compressor upstream duct 11 from the ejector outlet portion 50c together with the intake air flowing through the ejector 50.

  The intake air and evaporated fuel supplied to the compressor upstream duct 11 reach the intake manifold 18 via the compressor downstream duct 13, the intercooler 14, the intercooler downstream passage 15, the throttle body 16, and the surge tank 17, and are supplied to the engine 1 from the injector. It is mixed with the original combustion fuel and burned in the cylinder of the engine 1.

  By the way, the blow-by gas recirculated into the compressor housing from the blow-by gas passage 60 through the blow-by gas inflow portion 61 is sent to the compressor downstream duct 13, and the oil mist that has been cooled to be in the oil state is supplied to the compressor downstream duct. 13 is expected to move along the bottom (bottom).

  In this embodiment, the supercharging pressure introducing portion 50b of the ejector 50 is connected to the upper side of the duct between the downstream of the compressor 22 and the upstream of the intercooler 14 (that is, the compressor downstream duct 13) via the connection pipe 57. It is possible to prevent the oil mist from being sucked into the ejector 50 from the supply pressure introducing portion 50b and causing the ejector 50 to be clogged.

  As described above, the evaporated fuel processing apparatus for an engine with a supercharger according to the above embodiment is an evaporated fuel processing apparatus for an engine with a supercharger that purges the evaporated fuel generated in the fuel tank 30 to the engine with a supercharger. Thus, the ducts 11 and 13 upstream and downstream of the compressor 22 of the turbocharger 12 are provided substantially in parallel, and the evaporated fuel processing device C includes an ejector 50 having an evaporated fuel suction part 50a and a supercharging pressure introduction part 50b. The supercharging pressure introduction part 50b is connected to the upper side of the duct between the downstream of the compressor 22 and the upstream of the intercooler 14 (see the compressor downstream duct 13), and the outlet 50c of the ejector 50 is connected to the duct upstream of the compressor (the compressor upstream). It is connected to the lower side of the duct 11 (see FIGS. 1 to 4).

This configuration has the following effects.
That is, when the blow-by gas is cooled and becomes oily, it is predicted that the blow-by gas moves along the lower side of the duct. Therefore, the supercharging pressure introduction portion 50b of the ejector 50 is placed between the compressor 22 downstream and the intercooler 14 upstream. By connecting to the upper side of the duct 13, it is possible to prevent the above-described oil from being sucked into the ejector 50 from the supercharging pressure introducing portion 50 b and causing the ejector 50 to be clogged.
Further, since the ducts 11 and 13 upstream and downstream of the compressor 22 of the turbocharger 12 are provided substantially in parallel, and the ejector 50 is disposed between the substantially parallel ducts 11 and 13, the supercharging pressure introduction portion 50 b of the ejector 50 and The passage to the ejector outlet 50c, specifically, the upstream end of the connection pipe 57 and the passage to the ejector outlet 50c can be simplified.
In addition, since the supercharging pressure (intake) is introduced from the upstream side of the intercooler 14 to the ejector 50, the influence on the engine output is small.

  In one embodiment of the present invention, the blow-by gas inflow portion 61 is located downstream of the ejector 50 and upstream of the compressor 22 (see FIGS. 2 and 3).

  According to this configuration, since the blow-by gas inflow portion 61 is provided on the downstream side of the ejector 50 and on the upstream side of the compressor 22, the blow-by gas can easily flow into the upstream of the compressor 22, and the ejector outlet portion 50 c is Since the blow-by gas can be provided upstream of the blow-by gas inflow portion 61 where the blow-by gas does not directly flow, the ejector outlet portion 50c is connected to the lower side of the duct 11, and the supercharging pressure introduction portion 50b and the ejector outlet portion 50c of the ejector 50 are connected. It is possible to further simplify the path up to, specifically, the path to the upstream end of the connection pipe 57 and the ejector outlet 50c.

  In one embodiment of the present invention, the connecting portion 57a between the supercharging pressure introducing portion 50b of the ejector 50 and the duct 13 downstream of the compressor 22 is in the direction in which the compressed intake air flows through the connecting portion 57a and the compressor 22 (the direction of the arrow α). The angle θ1 formed with the flow direction of the compressed intake air is set to an acute angle (see FIG. 3).

According to this configuration, the angle θ1 formed by the direction (arrow α direction) in which the compressed intake air flows in the duct 13 downstream of the compressor 22 and the connecting portion 57a is set to an acute angle, so that the oil by which the blowby gas is cooled and liquefied It is possible to further suppress the inflow of the mist into the connection portion 57a to the supercharging pressure introduction portion 50b.
Therefore, the ejector can be prevented from being clogged even better.

  In one embodiment of the present invention, the connecting portion between the duct 11 upstream of the compressor 22 and the ejector outlet portion 50c (refer to the directing direction of the pipe 55 and the jacket portion 11c) is the flow direction of the connecting portion and the intake air. The angle θ2 formed with the intake air circulation direction is set to an acute angle so that (the arrow β direction) is the same direction (see FIG. 3).

  According to this configuration, since the angle θ2 formed by the direction in which the intake air flows in the duct 11 upstream of the compressor 22 (arrow β direction) and the connection portion is set to an acute angle, the evaporated fuel generated in the fuel tank 30 is reduced. It becomes easy to flow into the compressor upstream duct 11.

In the correspondence between the configuration of the present invention and the above-described embodiment,
The supercharger of the present invention corresponds to the turbocharger 12 of the embodiment,
Similarly,
The compressor upstream duct corresponds to the compressor upstream duct 11,
The compressor downstream duct corresponds to the compressor downstream duct 13,
The present invention is not limited to the configuration of the above-described embodiment.
For example, in the above embodiment, an I-type engine is exemplified, but the evaporated fuel processing device for a supercharged engine of this embodiment is also applicable to other supercharged engines such as a V-type engine and a rotary engine. can do.

  As described above, the present invention is useful for an evaporated fuel processing apparatus for an engine with a supercharger that purges the evaporated fuel generated in the fuel tank into the engine with a supercharger.

C ... Evaporative fuel processing device 1 ... Engine 11 ... Compressor upstream duct 12 ... Turbocharger (supercharger)
DESCRIPTION OF SYMBOLS 13 ... Compressor downstream duct 14 ... Intercooler 22 ... Compressor 30 ... Fuel tank 50 ... Ejector 50a ... Evaporated fuel suction part 50b ... Supercharging pressure introduction part 50c ... Outlet part 57a ... Connection part 61 ... Blow-by gas inflow part

Claims (4)

An evaporative fuel treatment device for a supercharged engine for purging evaporative fuel generated in a fuel tank to a supercharged engine,
The ducts upstream and downstream of the compressor of the supercharger are provided substantially in parallel,
The evaporative fuel processing apparatus has an ejector including an evaporative fuel suction part and a supercharging pressure introduction part,
The supercharging pressure introduction part is connected to the upper side of the duct between the compressor downstream and the intercooler upstream,
An evaporative fuel processing device for an engine with a supercharger, wherein an outlet portion of the ejector is connected to a lower side of a duct upstream of a compressor. The evaporated fuel processing device for an engine with a supercharger according to claim 1, wherein an inflow portion of blow-by gas is located downstream of the ejector and upstream of the compressor. The connecting part between the supercharging pressure introduction part of the ejector and the duct downstream of the compressor is
The evaporated fuel processing of an engine with a supercharger according to claim 1 or 2, wherein an angle formed by the flow direction of the compressed intake air is set to an acute angle so that the connection portion and the flow direction of the compressed intake air by the compressor are opposite to each other. apparatus. The connecting section between the duct upstream of the compressor and the ejector outlet is
The evaporated fuel of the supercharged engine according to any one of claims 1 to 3, wherein an angle formed by the intake flow direction is set to an acute angle so that the connection portion and the intake flow direction are the same direction. Processing equipment.

Images