Intake system of an internal combustion engine

Abstract

The objective is to provide an intake system for an internal combustion engine that can reduce the difference in intake pressure. [Solution] An intake system for an internal combustion engine comprising: a first intake passage connected to a first bank of the internal combustion engine; a second intake passage connected to a second bank 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 downstream 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 connecting 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] The present invention relates to an intake device for an internal combustion engine.

Background Art

[0002] Corresponding to the banks of a V-type engine, a plurality of intake passages may be provided, and a turbocharger may be provided for each intake passage (for example, Patent Document 1, etc.).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, due to variations in the performance of the turbocharger, etc., a difference in intake pressure may occur between the left and right banks. Therefore, an object is to provide an intake device for an internal combustion engine capable of reducing the difference in intake pressure.

Means for Solving the Problems

[0005] The above object can be achieved by an intake device for an internal combustion engine including a first intake passage connected to a first bank of the internal combustion engine, a second intake passage connected to a second bank 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 downstream of the first turbocharger in the first intake passage, a second throttle valve provided downstream of the second turbocharger in the second intake passage, 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.

[0006] The system may also include a first boost pressure sensor located in the first intake passage downstream of the first turbocharger and upstream of the first throttle valve, and a second boost pressure sensor located in the second intake passage downstream of the second turbocharger and upstream of the second throttle valve.

[0007] The first intake passage has a first intake manifold, the first intake manifold is connected to the first bank, and the second intake passage has a second intake manifold, the second intake manifold is connected to the second bank, and may also include a first pressure sensor provided on the first intake manifold and a second pressure sensor provided on the second intake manifold. [Effects of the Invention]

[0008] This invention provides an intake system for an internal combustion engine that can reduce the difference in intake pressure. [Brief explanation of the drawing]

[0009] [Figure 1] Figure 1 is a schematic diagram illustrating an intake device according to an embodiment. [Figure 2] Figure 2 illustrates a pressure difference. [Figure 3] Figures 3(a) and 3(b) illustrate exhaust pressure. [Modes for carrying out the invention]

[0010] The intake system of the internal combustion engine of this embodiment will be described below with reference to the drawings. Figure 1 is a schematic diagram illustrating an intake system 100 according to the embodiment. Air drawn in from the intake system 100 is supplied to the internal combustion engine 10. The internal combustion engine 10 is, for example, a V-type engine and has a bank 12 (first bank, right bank) and a bank 14 (second bank, left bank). Multiple cylinders are arranged in banks 12 and 14.

[0011] The intake system 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 bank 12 of the internal combustion engine 10 and introduces air to the cylinders of bank 12. The intake passage 40 (second intake passage) is connected to bank 14 of the internal combustion engine 10 and introduces air to the cylinders of bank 14.

[0012] The intake passage 20 includes intake passage 21, intake passage 22, intake passage 24, and intake manifold 26 (first intake manifold). The intake passage 20 is equipped with a turbocharger 32 (first turbocharger), intercooler 28, throttle valve 29 (first throttle valve), boost pressure sensor 37 (first boost pressure sensor), and pressure sensor 38 (first pressure sensor).

[0013] 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 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.

[0014] Intake passage 21 is located at the upstream end of intake passage 20 and is connected to the compressor housing 36. Intake passage 22 is connected to the compressor housing 36 and the intercooler 28. Intake passage 24 is located downstream of the intercooler 28. Intake manifold 26 is located at the downstream end of intake passage 20 and is connected to intake passage 24.

[0015] 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.

[0016] The intake passage 40 includes intake passage 41, intake passage 42, intake passage 44, and intake manifold 46 (second intake manifold). The intake passage 40 is equipped with a turbocharger 52 (second turbocharger), intercooler 48, throttle valve 49 (second throttle valve), boost pressure sensor 57 (second boost pressure sensor), and pressure sensor 58 (second pressure sensor).

[0017] The turbocharger 52 has a turbine housing 54 and a compressor housing 56. The exhaust passage 50 is connected to the bank 14 of the internal combustion engine 10 and the turbine housing 54. An exhaust pressure sensor 59 is provided in the exhaust passage 50.

[0018] Intake passage 41 is located at the upstream end of intake passage 40 and is connected to the compressor housing 56. Intake passage 42 is connected to the compressor housing 56 and the intercooler 48. Intake passage 44 is located downstream of the intercooler 48. Intake manifold 46 is located at the downstream end of intake passage 40 and is connected to intake passage 44.

[0019] 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 intercooler 48 and downstream of the turbocharger 52. A pressure sensor 58 is provided in the intake manifold 46.

[0020] The connecting pipe 60 is connected to a position in the intake passage 24 downstream of the throttle valve 29 and to a position in the intake passage 44 downstream of the throttle valve 49. In other words, the connecting pipe 60 is connected to a position in the intake passage 20 downstream of the throttle valve 29 and upstream of the intake manifold 26, and to a position in the intake passage 40 downstream of the throttle valve 49 and upstream of the intake manifold 46. Air flows between the intake passage 20 and the intake passage 40 through the connecting pipe 60. The inner diameter of the connecting pipe 60 may be equal to, for example, the inner diameter of the intake passage, or it may be smaller than the inner diameter of the intake passage.

[0021] Air is introduced into the intake passage 20 through the intake passage 21, flows through the intake passage 21, intake passage 22, intercooler 28, intake passage 24 and intake manifold 26, and is introduced into the bank 12 of the internal combustion engine 10. The intercooler 28 cools the air. The flow rate of the air changes according to the opening degree of the throttle valve 29. The larger the opening degree, the greater the flow rate. The smaller the opening degree, the smaller the flow rate.

[0022] An air-fuel mixture is generated in the cylinders of the bank 12, and the air-fuel mixture burns. The exhaust gas generated by the combustion is discharged through the exhaust passage 30. The exhaust gas is introduced into the turbine housing 34 of the turbocharger 32, and the turbine rotates. The compressor is connected to the turbine and rotates in synchronization with the turbine. The air is supercharged by the compressor.

[0023] Air is introduced into the bank 14 through the intake passage 40. The flow rate of the air changes according to the opening degree of the throttle valve 49. The exhaust gas generated in the bank 14 is introduced into the turbine housing 54 of the turbocharger 52, and the air is supercharged.

[0024] Figure 2 is a diagram illustrating the pressure difference. The horizontal axis represents the rotational speed NE of the internal combustion engine 10. The vertical axis represents the difference (intake pressure difference) ΔP in pressure between the intake manifold 26 and the intake manifold 46. ΔP is the difference between the pressure detected by the pressure sensor 38 and the pressure detected by the pressure sensor 58. The opening degrees of the throttle valve 29 and the throttle valve 49 are assumed to be equal to each other. The dotted line represents a comparative example. The comparative example is an example where the communication pipe 60 is not provided. The solid line represents an embodiment.

[0025] As shown in Figure 2, in the comparative example, the pressure difference ΔP is large. The pressure difference ΔP in the embodiment is smaller than that in the comparative example, and in the embodiment, the lower the rotational speed NE, the smaller the pressure difference ΔP. The higher the rotational speed NE, the larger the pressure difference ΔP. According to the rotational speed NE, the pressure in the intake manifold 26 and the pressure in the intake manifold 46 change in a similar manner.

[0026] Figures 3(a) and 3(b) illustrate exhaust pressure. Figure 3(a) shows the exhaust pressure in a comparative example. Figure 3(b) shows the exhaust pressure in the embodiment. The horizontal axis represents rotational speed NE. The vertical axis represents exhaust pressure. The solid line represents the pressure in the exhaust passage 30 detected by the exhaust pressure sensor 39. The dotted line represents the pressure in the exhaust passage 50 detected by the exhaust pressure sensor 59.

[0027] In both Figure 3(a) and Figure 3(b), the exhaust pressure is lower at lower rotational speeds and higher at higher rotational speeds. The difference between the exhaust pressure in exhaust passage 30 and exhaust pressure in exhaust passage 50 is large in the example of Figure 3(a) and small in the example of Figure 3(b). In other words, the difference in exhaust pressure is reduced according to the embodiment.

[0028] According to this embodiment, a connecting pipe 60 is connected to a position in the intake passage 20 downstream of the throttle valve 29 and to a position in the intake passage 40 downstream of the throttle valve 49. Air flows between the intake passage 24 and the intake passage 44 through the connecting pipe 60. The intake pressure between the intake passage 20 and the intake passage 40 becomes more uniform. That is, as shown in Figure 2, the pressure difference ΔP becomes smaller. Torque variations between bank 12 and bank 14 are suppressed.

[0029] As shown in Figure 3(b), the difference in exhaust pressure is reduced by providing the connecting pipe 60. The exhaust pressure introduced to turbocharger 32 and the exhaust pressure introduced to turbocharger 52 become closer to uniform. Therefore, the rotational speeds of turbocharger 32 and turbocharger 52 become approximately the same. The boost pressure in intake passage 20 and the boost pressure in intake passage 40 also become approximately the same. Torque variations between bank 12 and bank 14 are suppressed.

[0030] A boost pressure sensor 37 is located in the intake passage 20, downstream of the turbocharger 32 and upstream of the throttle valve 29. A boost pressure sensor 57 is located in the intake passage 40, downstream of the turbocharger 52 and upstream of the throttle valve 49. A malfunction can be detected by comparing the pressure detected by the boost pressure sensor 37 with the pressure detected by the boost pressure sensor 57. Under normal conditions, the pressure detected by the boost pressure sensor 37 and the pressure detected by the boost pressure sensor 57 are approximately the same. If these pressures differ significantly, it is presumed that a malfunction has occurred, such as a failure of the boost pressure sensor, blockage of the passage, or a malfunction of the turbocharger.

[0031] A pressure sensor 38 is provided on the intake manifold 26. A pressure sensor 58 is provided on the intake manifold 46. A malfunction can be detected by comparing the pressure detected by pressure sensor 38 with the pressure detected by pressure sensor 58. Under normal conditions, the pressure detected by pressure sensor 38 and the pressure detected by pressure sensor 58 are approximately the same. If these pressures differ significantly, it is presumed that a malfunction has occurred.

[0032] Each of the two intake passages 20 and 40 is equipped with one boost pressure sensor and one pressure sensor, allowing for fault detection by comparing the pressures. This eliminates the need for additional fault detection sensors, resulting in reduced costs.

[0033] Although preferred embodiments of the present invention have been described in detail above, the present invention is not limited to these specific embodiments, and various modifications and changes are possible within the scope of the gist of the invention as described in the claims. [Explanation of Symbols]

[0034] 10 Internal combustion engine, 12, 14 Bank, 20, 21, 22, 24, 40, 41, 42, 44 Intake passage, 26, 46 Intake manifold, 28, 48 Intercooler, 29, 49 Throttle valve, 32, 52 Turbocharger, 34, 54 Turbine housing, 36, 56 Compressor housing, 30, 50 Exhaust passage, 37, 57 Boost pressure sensor, 38, 58 Pressure sensor, 39, 59 Exhaust pressure sensor, 100 Intake system

Claims

1. A first intake passage connected to the first bank of an internal combustion engine, A second intake passage connected to the second bank of the internal combustion engine, A first turbocharger provided in the first intake passage, A second turbocharger is provided in the second intake passage, A first throttle valve provided downstream of the first turbocharger in the first intake passage, A second throttle valve located downstream of the second turbocharger in the second intake passage, An intake system for an internal combustion engine comprising a connecting pipe connected to a position downstream of the first throttle valve in the first intake passage and to a position downstream of the second throttle valve in the second intake passage.

2. A first boost pressure sensor is provided in the first intake passage downstream of the first turbocharger and upstream of the first throttle valve, An intake system for an internal combustion engine according to claim 1, comprising: a second boost pressure sensor provided in the second intake passage downstream of the second turbocharger and upstream of the second throttle valve.

3. The first intake passage has a first intake manifold, The first intake manifold is connected to the first bank, The second intake passage has a second intake manifold, The second intake manifold is connected to the second bank, The first pressure sensor provided in the first intake manifold, An intake system for an internal combustion engine according to claim 1 or 2, comprising a second pressure sensor provided on the second intake manifold.

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