Internal combustion engine

Abstract

To suppress the generation of condensed water in EGR gas recirculated upstream of a compressor by heating the EGR gas, without requiring a complicated apparatus configuration.SOLUTION: An internal combustion engine comprises an EGR device that recirculates a portion of exhaust gas upstream of a compressor as EGR gas. The internal combustion engine has an annular passage surrounding an intake passage of a compressor housing, and an extension passage connected to the annular passage, the EGR gas being introduced into the intake passage of the compressor housing via the annular passage and the extension passage.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to an internal combustion engine. [Background technology]

[0002] The following Patent Document 1 discloses a technology for suppressing the generation of condensed water originating from EGR gas upstream of the turbocharger compressor by using a wall heating device to heat the wall temperature of the intake passage between a low-pressure EGR (Exhaust Gas Recirculation) passage and a turbocharger. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2018-021510 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the technique of Patent Document 1, the wall heating device uses the cooling water of the internal combustion engine to heat the wall of the intake passage, and therefore a complex device configuration is required to heat the wall of the intake passage. [Means for solving the problem]

[0005] In order to solve the above-mentioned problems, an internal combustion engine according to one embodiment is an internal combustion engine equipped with an EGR device that recirculates a portion of the exhaust gas as EGR gas upstream of the compressor, and has an annular passage that surrounds the intake passage of the compressor housing and an extension passage that connects to the annular passage, and introduces the EGR gas into the intake passage of the compressor housing via the annular passage and the extension passage. [Effects of the Invention]

[0006] According to an internal combustion engine according to one embodiment, it is possible to heat the EGR gas that is recirculated upstream of the compressor and suppress the generation of condensed water in the EGR gas, without requiring a complex device configuration. [Brief explanation of the drawings]

[0007] [Figure 1] 1 is a diagram showing a configuration of an internal combustion engine according to an embodiment; [Figure 2] FIG. 1 is a cross-sectional view of a turbocharger according to an embodiment. [Figure 3] FIG. 1 is a partially enlarged view of a compressor housing included in a turbocharger according to an embodiment, viewed from the intake passage side; [Figure 4] FIG. 10 is a diagram showing a first modified example of an introduction location of EGR gas in a supercharger of an internal combustion engine according to one embodiment; [Figure 5] FIG. 10 is a diagram showing a second modified example of an introduction location of EGR gas in a supercharger of an internal combustion engine according to an embodiment; DETAILED DESCRIPTION OF THE INVENTION

[0008] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0009] (Configuration of internal combustion engine 1) Fig. 1 is a diagram showing the configuration of an internal combustion engine 1 according to one embodiment. The internal combustion engine 1 shown in Fig. 1 is mounted on a vehicle such as an automobile, for example, and generates driving force for running the vehicle.

[0010] As shown in FIG. 1, the internal combustion engine 1 includes an engine 10, an intake passage 20, an exhaust passage 30, and a supercharger .

[0011] The intake passage 20 is a flow path for air taken in through an intake port 20A and supplied to the engine 10. The intake passage 20 is provided with, in order from the intake port 20A side, an air cleaner 21, an AFM (Air Flow Meter) 22, a sub-throttle 23, a main throttle 24, and an intercooler 25. The air cleaner 21 purifies the air taken in through the intake port 20A. The AFM 22 detects the intake air amount. The sub-throttle 23 adjusts the flow rate of air taken in by the compressor 41 of the turbocharger 40. The main throttle 24 adjusts the flow rate of compressed air taken in to the cylinders 12 of the engine 10. The intercooler 25 is provided between the main throttle 24 and the intake port 11 of the engine 10 and cools the compressed air taken in to the cylinders 12 of the engine 10.

[0012] The engine 10 generates driving torque by compressing and burning compressed air drawn in from the intake passage 20 via the intake port 11 and fuel supplied from a fuel injection device (not shown) in the cylinder 12, and outputs the driving torque from a crankshaft (not shown). The engine 10 also discharges exhaust gas generated in the cylinder 12 from the exhaust port 13 to the exhaust passage 30.

[0013] The exhaust path 30 is a flow path for exhaust gas discharged from the exhaust port 13 of the engine 10. The exhaust gas flowing through the exhaust path 30 is discharged into the atmosphere from an exhaust port 30A. An S / C (exhaust gas purification catalyst) 31 that purifies the exhaust gas is provided downstream of the exhaust turbine 42 of the turbocharger 40 in the exhaust path 30.

[0014] The turbocharger 40 has a compressor 41 provided at an intermediate position in the intake passage 20 and an exhaust turbine 42 provided at an intermediate position in the exhaust passage 30. The turbocharger 40 receives energy of the exhaust gas flowing through the exhaust passage 30 by the exhaust turbine 42, and uses this energy to compress the air flowing through the intake passage 20 by the compressor 41.

[0015] The internal combustion engine 1 also includes an EGR device 50. The EGR device 50 includes a recirculation passage 51, an EGR cooler 52, and an EGR valve 53. The recirculation passage 51 is provided between the exhaust passage 30 (downstream of the exhaust turbine 42) and the intake passage 20 (upstream of the compressor 41), and recirculates a portion of the exhaust gas flowing through the exhaust passage 30 as EGR gas upstream of the compressor 41. The EGR cooler 52 is provided in the recirculation passage 51, and cools the EGR gas flowing through the recirculation passage 51. The EGR valve 53 is provided in the recirculation passage 51, and adjusts the flow rate of the EGR gas recirculated upstream of the compressor 41.

[0016] (Configuration of the turbocharger 40) Fig. 2 is a cross-sectional view of a turbocharger 40 according to one embodiment. Fig. 3 is a partially enlarged view of a compressor housing 43 of a compressor 41 included in the turbocharger 40 according to one embodiment, viewed from the intake passage 43A side.

[0017] 2 and 3, the compressor housing 43 of the compressor 41 has an intake passage 43A that has a substantially circular cross section. A compressor wheel 44 is provided inside the intake passage 43A and rotates to compress the air taken in through the intake passage 43A.

[0018] As shown in Figures 2 and 3, inside the intake passage 43A (upstream of the compressor wheel 44), there is provided an approximately circular annular passage 45 made of a hollow pipe that extends along the inner circumferential direction of the inner wall surface of the wall portion 43B surrounding the intake passage 43A.

[0019] An intake port 45A provided at one end of the annular passage 45 penetrates a wall portion 43B surrounding the intake passage 43A in the compressor housing 43 and is connected to a return passage 51 of the EGR device 50. As a result, EGR gas supplied from the EGR device 50 is drawn into the annular passage 45 from the intake port 45A.

[0020] A discharge port 45B provided at the other end of the annular passage 45 is open into the intake passage 43A (upstream of the compressor wheel 44). As a result, the EGR gas that has flowed through the annular passage 45 is discharged from the discharge port 45B into the intake passage 43A (upstream of the compressor wheel 44).

[0021] 3, an adapter 46 is provided on the outside of a wall portion 43B surrounding the intake passage 43A in the compressor housing 43. An extension passage 46A is provided in the adapter 46. The inlet and outlet of the extension passage 46A are connected to the annular passage 45. As a result, a portion of the EGR gas flowing through the annular passage 45 flows through the extension passage 46A and then joins the annular passage 45.

[0022] 2 and 3, the annular passage 45 is provided in close contact with the inner wall surface of the wall portion 43B of the compressor housing 43. Therefore, the annular passage 45 is heated by the heat of the compressor housing 43, and thereby the EGR gas flowing through the annular passage 45 can be heated.

[0023] 3, the adapter 46 is provided in close contact with the outer wall surface of the wall portion 43B of the compressor housing 43. Therefore, the adapter 46 is heated by the heat of the compressor housing 43, and thereby the EGR gas flowing through the extension path 46A of the adapter 46 can be heated.

[0024] In the example shown in Figure 3, a portion of the EGR gas flowing through the annular passage 45 flows through the extension passage 46A, but as another example, all of the EGR gas flowing through the annular passage 45 may flow through the extension passage 46A.

[0025] Thus, the internal combustion engine 1 according to one embodiment has an annular passage 45 that surrounds the intake passage 43A of the compressor housing 43, and an extension passage 46A that is connected to the annular passage 45 and is formed from a material with approximately the same thermal conductivity as the annular passage 45, and introduces EGR gas into the intake passage 43A of the compressor housing 43 via the annular passage 45 and the extension passage 46A.

[0026] As a result, the internal combustion engine 1 according to one embodiment can evaporate the moisture contained in the EGR gas by utilizing the heat of the compressor housing 43 to heat the EGR gas using the annular passage 45 and the extension passage 46A.

[0027] Therefore, the internal combustion engine 1 according to one embodiment can heat the EGR gas recirculated upstream of the compressor and suppress the generation of condensed water in the EGR gas without requiring a complex device configuration.

[0028] In particular, in one embodiment of the internal combustion engine 1, the EGR gas heated by the annular passage 45 and the extension passage 46A can be discharged inside the intake passage 43A of the compressor housing 43 (upstream of the compressor wheel 44), thereby shortening the path after the EGR gas is discharged (i.e., the path of the mixture of fresh air and EGR gas), and preventing moisture from mixing into the EGR gas in the path after the EGR gas is discharged.

[0029] In the internal combustion engine 1 according to one embodiment, the adapter 46 and the extension passage 46A are preferably made of a material having a thermal conductivity substantially equal to or higher than that of the compressor housing 43.

[0030] In this case, the internal combustion engine 1 according to one embodiment can increase the efficiency of heating the adapter 46 and the extension passage 46A by the heat of the compressor housing 43, and therefore can increase the efficiency of heating the EGR gas flowing through the extension passage 46A.

[0031] In addition, in the example shown in Figure 3, the EGR gas supplied from the EGR device 50 is sucked in through the circular path 45 and flows through the circular path 45 and the extension path 46A, but this is not limited to this, and the EGR gas supplied from the EGR device 50 may be sucked in through the adapter 46 and flow through the extension path 46A and the circular path 45.

[0032] Furthermore, in the internal combustion engine 1 according to one embodiment, at least a portion of the annular passage 45 and the extension passage 46A may be configured to include a porous material (for example, ceramic or the like).

[0033] In this case, the internal combustion engine 1 according to one embodiment can evaporate the moisture contained in the EGR gas by heating the annular passage 45 and the extension passage 46A, and can adsorb the moisture contained in the EGR gas by the porous material provided in the annular passage 45 and the extension passage 46A, thereby further suppressing the generation of condensed water in the EGR gas.

[0034] (First modified example of the EGR gas introduction location) FIG. 4 is a diagram showing a first modified example of an introduction point of EGR gas in the supercharger 40 of the internal combustion engine 1 according to one embodiment.

[0035] Furthermore, in the internal combustion engine 1 according to one embodiment, the compressor housing 43 may have at least one casing treatment 47 (recirculation flow path) on the outer wall portion 43B of the intake passage 43A, as shown in FIG. 4, for returning a portion of the air flowing through the intake passage 43A from the downstream side to the upstream side.

[0036] In this case, in an internal combustion engine 1 according to one embodiment, for example, as shown in FIG. 4, the discharge port 45B of the annular passage 45 may be connected to at least one casing treatment 47 so that the EGR gas that has flowed through the annular passage 45 and the extension passage 46A is introduced into at least one casing treatment 47.

[0037] In this case, the internal combustion engine 1 according to one embodiment can further heat the EGR gas that has flowed through the annular passage 45 and the extension passage 46A within the casing treatment 47, making it easier for the moisture contained in the EGR gas to evaporate, thereby further suppressing the generation of condensed water in the EGR gas.

[0038] In this case, the internal combustion engine 1 according to one embodiment can mix and stir the EGR gas that has flowed through the annular passage 45 and the extension passage 46A with air by passing it through the casing treatment 47, which makes it easier for the moisture contained in the EGR gas to evaporate, thereby further suppressing the generation of condensed water in the EGR gas.

[0039] (Second modified example of the EGR gas introduction location) FIG. 5 is a diagram showing a first modified example of an introduction point of EGR gas in the supercharger 40 of the internal combustion engine 1 according to one embodiment.

[0040] In one embodiment of the internal combustion engine 1, the discharge port 45B of the annular passage 45 may be located at a negative pressure generation point P in the intake passage 43A where negative pressure is generated by the flow of intake air, so that the EGR gas that has flowed through the annular passage 45 and the extension passage 46A can be introduced into the negative pressure generation point P.

[0041] For example, as shown in Figure 5, if the intake passage 43A has a curved shape, the discharge port 45B of the annular passage 45 may be provided at the negative pressure generating point P, which is the inner peripheral part of the intake passage 43A, so that the EGR gas that has flowed through the annular passage 45 and the extension passage 46A can be introduced into the negative pressure generating point P.

[0042] In this case, in the internal combustion engine 1 according to one embodiment, the negative pressure generation point P is at a lower pressure than other points, so that the moisture contained in the EGR gas is more likely to evaporate at the negative pressure generation point P, thereby further suppressing the generation of condensed water in the EGR gas.

[0043] Although the preferred embodiments of the present invention have been described in detail above, the present invention is not limited to these embodiments, and various modifications and changes are possible within the scope of the gist of the present invention described in the claims. [Explanation of symbols]

[0044] 1. Internal combustion engine 10 Engine 11 Intake port 12 cylinders 13 Exhaust port 20 Intake passage 20A Intake 21 Air cleaner 22 AFM 23 Sub-throttle 24 Main Throttle 25 Intercooler 30 Exhaust duct 30A Exhaust port 30A 31 S / C 40 Supercharger 41 Compressor 42 Exhaust turbine 43 Compressor housing 43A Intake passage 43B Wall section 44 Compressor Wheel 45 Ring Road 45A inlet 45B Discharge port 46 Adapter 46A extension road 47 Casing Treatment 50 EGR device 51 Reflux passage 52 EGR cooler 53 EGR valve P Negative pressure location

Claims

1. An internal combustion engine equipped with an EGR device that recirculates a portion of exhaust gas as EGR gas upstream of a compressor, an annular passage surrounding an intake passage of the compressor housing; an extension road connected to the circular road; and The EGR gas is introduced into the intake passage of the compressor housing through the annular passage and the extension passage. An internal combustion engine characterized by:

2. The extension path is formed of a material having a thermal conductivity equal to or greater than that of the compressor housing.

2. The internal combustion engine according to claim 1.

3. The EGR gas is In the intake passage, the intake air is introduced into a negative pressure generating location where negative pressure is generated by the flow of intake air.

2. The internal combustion engine according to claim 1.

4. The EGR gas is The intake passage is provided with a casing treatment.

2. The internal combustion engine according to claim 1.

5. At least a portion of the annular path and the extension path has a porous material.

2. The internal combustion engine according to claim 1.

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