Air intake device for internal combustion engine

Abstract

The present invention addresses the problem of providing an intake device for an internal combustion engine capable of reducing the difference in intake pressure. An intake device for an internal combustion engine is provided with: a first intake passage connected to a first cylinder block of the internal combustion engine; a second intake passage connected to a second cylinder block of the internal combustion engine; a first turbocharger provided in the first intake passage; a second turbocharger provided in the second intake passage; a first throttle valve provided on the downstream side of the first turbocharger in the first intake passage; a second throttle valve provided downstream of the second turbocharger in the second intake passage; and a communication pipe connected to a position downstream of the first throttle valve in the first intake passage and a position downstream of the second throttle valve in the second intake passage.

Description

Technical Field

[0001] This invention relates to the air intake device for internal combustion engines. Background Technology

[0002] Sometimes multiple intake passages are provided corresponding to the cylinder banks of a V-type engine, and a turbocharger is provided for each intake passage (e.g., Patent Document 1).

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2020-020323 Summary of the Invention

[0006] The problem that the invention aims to solve

[0007] However, due to variations in turbocharger performance, a pressure difference sometimes occurs between the left and right cylinder banks. Therefore, the aim is to provide an intake system for an internal combustion engine that can reduce this pressure difference.

[0008] Technical solutions for solving the problem

[0009] The aforementioned objective can be achieved by an intake system for an internal combustion engine comprising: a first intake passage connected to a first cylinder bank of the internal combustion engine; a second intake passage connected to a second cylinder bank of the internal combustion engine; a first turbocharger disposed in the first intake passage; a second turbocharger disposed in the second intake passage; a first throttle valve disposed in the first intake passage downstream of the first turbocharger; a second throttle valve disposed in the second intake passage downstream of the second turbocharger; and a connecting pipe connected to both the downstream position in the first intake passage (below the first throttle valve) and the downstream position in the second intake passage (below the second throttle valve).

[0010] Alternatively, it may include: a first boost pressure sensor disposed in the first intake passage downstream of the first turbocharger and upstream of the first throttle valve; and a second boost pressure sensor disposed in the second intake passage downstream of the second turbocharger and upstream of the second throttle valve.

[0011] Alternatively, the first intake passage may have a first intake manifold connected to the first cylinder bank, and the second intake passage may have a second intake manifold connected to the second cylinder bank, comprising: a first pressure sensor disposed in the first intake manifold; and a second pressure sensor disposed in the second intake manifold.

[0012] Invention Effects

[0013] An intake device for an internal combustion engine can be provided that can reduce the intake pressure difference. Attached Figure Description

[0014] Figure 1 This is a schematic diagram illustrating the air intake device involved in the illustrative embodiment.

[0015] Figure 2 This is a diagram illustrating the pressure difference.

[0016] Figure 3 (a) and Figure 3 (b) is a diagram illustrating exhaust pressure. Detailed Implementation

[0017] Hereinafter, the intake device of the internal combustion engine of this embodiment will be described with reference to the accompanying drawings. Figure 1 This is a schematic diagram illustrating the intake device 100 according to an exemplary embodiment. Air drawn from the intake device 100 is supplied to the internal combustion engine 10. The internal combustion engine 10 is, for example, a V-type engine, having cylinder banks 12 (first cylinder bank, right cylinder bank) and cylinder banks 14 (second cylinder bank, left cylinder bank). Multiple cylinders are arranged in cylinder banks 12 and 14.

[0018] The intake device 100 has an intake passage 20, an intake passage 40, and a connecting pipe 60. The intake passage 20 (first intake passage) is connected to the cylinder bank 12 of the internal combustion engine 10 and introduces air into the cylinders of the cylinder bank 12. The intake passage 40 (second intake passage) is connected to the cylinder bank 14 of the internal combustion engine 10 and introduces air into the cylinders of the cylinder bank 14.

[0019] The intake passage 20 includes an intake passage 21, an intake passage 22, an intake passage 24, and an intake manifold 26 (first intake manifold). The intake passage 20 is equipped with a turbocharger 32 (first turbocharger), an intercooler 28, a throttle valve 29 (first throttle valve), a boost pressure sensor 37 (first boost pressure sensor), and a pressure sensor 38 (first pressure sensor).

[0020] The turbocharger 32 has a turbine housing 34 and a compressor housing 36. The turbine housing 34 houses the turbine. The compressor housing 36 houses the compressor. The exhaust passage 30 is connected to the cylinder bank 12 of the internal combustion engine 10 and the turbine housing 34. An exhaust pressure sensor 39 is provided in the exhaust passage 30.

[0021] Intake passage 21 is located at the upstream end of intake passage 20 and is connected to compressor housing 36. Intake passage 22 is connected to compressor housing 36 and intercooler 28. Intake passage 24 is located downstream of intercooler 28. Intake manifold 26 is located at the downstream end of intake passage 20 and is connected to intake passage 24.

[0022] A throttle valve 29 is provided in the intake passage 24. A boost pressure sensor 37 is provided in the intake passage 22, located upstream of the throttle valve 29 and intercooler 28 and downstream of the turbocharger 32. A pressure sensor 38 is provided in the intake manifold 26.

[0023] The intake passage 40 includes an intake passage 41, an intake passage 42, an intake passage 44, and an intake manifold 46 (second intake manifold). A turbocharger 52 (second turbocharger), an intercooler 48, a throttle valve 49 (second throttle valve), a boost pressure sensor 57 (second boost pressure sensor), and a pressure sensor 58 (second pressure sensor) are installed in the intake passage 40.

[0024] The turbocharger 52 has a turbine housing 54 and a compressor housing 56. The exhaust passage 50 is connected to the cylinder bank 14 and the turbine housing 54 of the internal combustion engine 10. An exhaust pressure sensor 59 is provided in the exhaust passage 50.

[0025] Intake passage 41 is located at the upstream end of intake passage 40 and is connected to compressor housing 56. Intake passage 42 is connected to compressor housing 56 and intercooler 48. Intake passage 44 is located downstream of intercooler 48. Intake manifold 46 is located at the downstream end of intake passage 40 and is connected to intake passage 44.

[0026] A throttle valve 49 is provided in the intake passage 44. A boost pressure sensor 57 is provided in the intake passage 42, located upstream of the throttle valve 49 and the intercooler 48 and downstream of the turbocharger 52. A pressure sensor 58 is provided in the intake manifold 46.

[0027] The connecting pipe 60 connects to a position downstream of throttle valve 29 in intake passage 24 and a position downstream of throttle valve 49 in intake passage 44. In other words, the connecting pipe 60 connects to a position downstream of throttle valve 29 and upstream of intake manifold 26 in intake passage 20, and to a position downstream of throttle valve 49 and upstream of intake manifold 46 in intake passage 40. Air flows between intake passage 20 and intake passage 40 through the connecting pipe 60. The inner diameter of the connecting pipe 60 may be equal to or smaller than the inner diameter of the intake passage.

[0028] Air is introduced into intake passage 20 through intake passage 21, flows through intake passage 21, intake passage 22, intercooler 28, intake passage 24, and intake manifold 26, and is then introduced into cylinder bank 12 of internal combustion engine 10. Intercooler 28 cools the air. The airflow rate varies depending on the opening of throttle valve 29. A larger opening results in a larger airflow rate, while a smaller opening results in a smaller airflow rate.

[0029] In cylinder bank 12, an air-fuel mixture is generated and combusted. The exhaust gas produced by combustion is discharged through exhaust passage 30. This exhaust gas is introduced into the turbine housing 34 of turbocharger 32, causing the turbine to rotate. A compressor is connected to the turbine and rotates synchronously with it. The compressor pressurizes the air.

[0030] Air is introduced into cylinder bank 14 through intake passage 40. The airflow varies depending on the opening of throttle valve 49. Exhaust generated in cylinder bank 14 is directed into turbine housing 54 of turbocharger 52, where the air is pressurized.

[0031] Figure 2 This is a diagram illustrating the pressure difference. The horizontal axis represents the engine speed NE of the internal combustion engine 10. The vertical axis represents the pressure difference (intake pressure difference) ΔP between the intake manifold 26 and the intake manifold 46. ΔP is the pressure difference detected by pressure sensor 38 and pressure sensor 58. The opening degrees of throttle valve 29 and throttle valve 49 are assumed to be equal. The dashed line represents a comparative example. The comparative example is an example without the connecting pipe 60. The solid line represents the implementation method.

[0032] like Figure 2 As shown, in the comparative example, the pressure difference ΔP is large. In the embodiment, the pressure difference ΔP is smaller than in the comparative example. Furthermore, in the embodiment, the lower the engine speed NE, the smaller the pressure difference ΔP. The higher the engine speed NE, the larger the pressure difference ΔP. The pressure in the intake manifold 26 and the pressure in the intake manifold 46 change in the same way depending on the engine speed NE.

[0033] Figure 3 (a) and Figure 3 (b) is a diagram illustrating exhaust pressure. Figure 3 (a) represents the exhaust pressure in the comparative example. Figure 3 (b) Indicates the exhaust pressure in the embodiment. The horizontal axis represents the rotational speed NE. The vertical axis represents the exhaust pressure. The solid line represents the pressure in the exhaust passage 30 detected by the exhaust pressure sensor 39. The dashed line represents the pressure in the exhaust passage 50 detected by the exhaust pressure sensor 59.

[0034] exist Figure 3 (a) and Figure 3(b) Of these two, the lower the engine speed, the lower the exhaust pressure. The higher the engine speed, the higher the exhaust pressure. The difference between the exhaust pressure in exhaust passage 30 and the exhaust pressure in exhaust passage 50 is... Figure 3 In example (a), the large, in Figure 3 In example (b), the difference is smaller. That is, according to the implementation method, the difference in exhaust pressure is reduced.

[0035] According to the embodiment, a connecting pipe 60 is connected in the intake passage 20 at a position downstream of the throttle valve 29 and in the intake passage 40 at a position downstream of the throttle valve 49. Air flows through the connecting pipe 60 between the intake passage 24 and the intake passage 44. The intake pressure is approximately equal between the intake passage 20 and the intake passage 40. That is, as... Figure 2 As shown, the pressure difference ΔP decreases. This suppresses the torque deviation between cylinder group 12 and cylinder group 14.

[0036] like Figure 3 As shown in (b), by providing the connecting pipe 60, the pressure difference of the exhaust gas also decreases. The pressure of the exhaust gas introduced into the turbocharger 32 is nearly uniform with the pressure of the exhaust gas introduced into the turbocharger 52. Therefore, the speeds of the turbocharger 32 and the turbocharger 52 become the same. The boost pressure of the intake passage 20 and the boost pressure of the intake passage 40 also become the same. This suppresses the torque deviation between cylinder bank 12 and cylinder bank 14.

[0037] A boost pressure sensor 37 is installed in the intake passage 20, downstream of the turbocharger 32 and upstream of the throttle valve 29. A boost pressure sensor 57 is also installed in the intake passage 40, downstream of the turbocharger 52 and upstream of the throttle valve 49. Faults can be detected by comparing the pressure detected by boost pressure sensor 37 and boost pressure sensor 57. Under normal conditions, the pressure detected by boost pressure sensor 37 and boost pressure sensor 57 are at roughly the same level. Significant differences in these pressures suggest a fault, such as a boost pressure sensor malfunction, passage blockage, or turbocharger failure.

[0038] A pressure sensor 38 is installed in the intake manifold 26. A pressure sensor 58 is installed in the intake manifold 46. Faults can be detected by comparing the pressure detected by pressure sensor 38 and pressure sensor 58. Under normal conditions, the pressure detected by pressure sensor 38 and pressure sensor 58 are at the same level. Significant differences in these pressures indicate a fault.

[0039] A boost pressure sensor and a pressure sensor are installed in each of the two intake passages 20 and 40, respectively. Fault detection can be performed by comparing the pressures. This eliminates the need for additional fault detection sensors, thus reducing costs.

[0040] The preferred embodiments of the present invention have been described in detail above, but the present invention is not limited to these specific embodiments. Various modifications and alterations can be made within the scope of the spirit of the present invention as described in the claims.

[0041] Marker description

[0042] 10 Internal combustion engine, 12, 14 cylinder banks, 20, 21, 22, 24, 40, 41, 42, 44 intake passages, 26, 46 intake manifolds, 28, 48 intercoolers, 29, 49 throttle valves, 32, 52 turbochargers, 34, 54 turbine housings, 36, 56 compressor housings, 30, 50 exhaust passages, 37, 57 boost pressure sensors, 38, 58 pressure sensors, 39, 59 exhaust pressure sensors, 100 intake system.

Claims

1. An intake device for an internal combustion engine, wherein, have: The first intake passage is connected to the first cylinder bank of the internal combustion engine; The second intake passage is connected to the second cylinder bank of the internal combustion engine; A first turbocharger is disposed in the first intake passage; A second turbocharger is located in the second intake passage; The first throttle valve is located in the first intake passage at a downstream position from the first turbocharger. The second throttle valve is located in the second intake passage downstream of the second turbocharger; as well as The connecting pipe is connected to a position downstream of the first throttle valve in the first intake passage and a position downstream of the second throttle valve in the second intake passage.

2. The intake device for an internal combustion engine according to claim 1, wherein, have: A first boost pressure sensor is disposed in the first intake passage, downstream of the first turbocharger and upstream of the first throttle valve; and The second boost pressure sensor is located in the second intake passage, downstream of the second turbocharger and upstream of the second throttle valve.

3. The intake device for an internal combustion engine according to claim 1 or 2, wherein, The first intake passage has a first intake manifold. The first intake manifold is connected to the first cylinder bank. The second intake passage has a second intake manifold. The second intake manifold is connected to the second cylinder bank. The intake device of the internal combustion engine includes: A first pressure sensor is disposed in the first intake manifold; and The second pressure sensor is located in the second intake manifold.

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