JP2017008863A - Suction/exhaust system of internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To recirculate exhausted air from an exhaust passage to a suction passage while performing supercharging.SOLUTION: A suction/exhaust system of an internal combustion engine includes: cylinders 13a-13d provided in an engine 10; a suction passage 20 introducing suctioned air into the cylinder 13a-13d; a low-pressure stage supercharger 50 and a high-pressure stage supercharger 60 configured to compress suctioned air; exhaust passages 31a-31c introducing into the high-pressure stage supercharger 60 exhausted air discharged from each of the cylinders 13a-13c among the cylinders 13a-13d; exhaust passages 31d, 31e provided so as to avoid the high-pressure stage supercharger 60, and introducing exhausted air discharged from the cylinder 13d into the low-pressure stage supercharger 50 provided on a downstream side with respect to the high-pressure stage supercharger 60; and an EGR passage 40 connecting between the exhaust passage 31d and the suction passage 20, and recirculating exhausted air discharged from the cylinder 13d to the suction passage 20.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an intake / exhaust system for an internal combustion engine, and more particularly to an intake / exhaust system for an internal combustion engine having a plurality of superchargers.

  An intake / exhaust system of an engine that is an internal combustion engine is a system that supplies intake air necessary for combustion of the engine to the engine and exhausts exhaust gas after combustion. The intake / exhaust system includes an exhaust gas recirculation passage and a supercharger that compresses intake air. The recirculation passage is a passage that recirculates a part of the exhaust discharged from the engine to the exhaust passage to the intake passage for introducing the intake air into the engine from the viewpoint of lowering the combustion temperature of the engine.

  The supercharger uses the exhaust gas in the exhaust passage to compress the intake air in the intake passage. For example, Patent Document 1 below discloses a two-stage supercharging system that has a low-pressure stage supercharger and a high-pressure stage supercharger and boosts intake air in two stages, a low-pressure stage and a high-pressure stage. Yes.

JP 2007-138845 A

  In recent years, there has been a demand for higher supercharging with a supercharger from the viewpoint of improving fuel efficiency. However, when increasing the operating efficiency of two superchargers arranged in series as in the two-stage supercharging system shown in Patent Document 1 in order to achieve high supercharging, exhaust from all cylinders of the engine There is a possibility that the pressure of the exhaust gas becomes excessive, and the exhaust gas cannot be properly recirculated into the intake passage. In addition, since exhaust gas from all cylinders is introduced into the low pressure turbocharger after passing through the high pressure turbocharger, it is difficult to increase the operating efficiency of the low pressure turbocharger.

  Therefore, the present invention has been made in view of these points, and an object thereof is to appropriately recirculate exhaust gas from an exhaust passage to an intake passage while realizing high supercharging.

In one aspect of the present invention, a cylinder group including three or more cylinders provided in an internal combustion engine, an intake passage for introducing intake air into the cylinder group, a low-pressure supercharger for compressing the intake air, and A high pressure turbocharger, a first exhaust passage for introducing exhaust gas discharged from each of the plurality of first cylinders of the cylinder group into the high pressure turbocharger, and bypassing the high pressure turbocharger The exhaust discharged from the second cylinder different from the first cylinder in the cylinder group is sent to the low-pressure supercharger provided downstream of the high-pressure supercharger. A second exhaust passage to be introduced; and a recirculation passage that connects the second exhaust passage and the intake passage and recirculates the exhaust discharged from the second cylinder to the intake passage. An internal combustion engine intake and exhaust system is provided.
According to such an intake / exhaust system, exhaust of a plurality of cylinders is stably introduced into the high-pressure stage supercharger, so that the operating efficiency of the high-pressure stage supercharger can be increased. Further, since the second exhaust passage of the first exhaust passage and the second exhaust passage is connected to the recirculation passage, the intake air in the intake passage is reduced compared to the case where the plurality of exhaust passages are connected to the recirculation passage. Since it can suppress that the pressure of the exhaust_gas | exhaustion of an exhaust passage becomes excessive with respect to a pressure, exhaust_gas | exhaustion can be appropriately recirculated to an intake passage. Further, since the exhaust gas that is not recirculated to the recirculation passage is introduced into the low-pressure stage supercharger, the operating efficiency of the low-pressure stage supercharger can be increased.

  The intake / exhaust system of the internal combustion engine further includes an exhaust pressure adjusting unit that is provided downstream of the connection point with the recirculation passage in the second exhaust passage and adjusts the pressure of the exhaust gas in the second exhaust passage. It is good also as providing.

  The intake / exhaust system of the internal combustion engine further includes a first flow rate adjusting unit that is provided downstream of the connection point with the recirculation passage in the second exhaust passage and adjusts the flow rate of the exhaust gas in the recirculation passage. It is good as well.

  Further, the plurality of first cylinders are three first cylinders, and the high-pressure supercharger is a first scroll into which exhaust exhausted from two first cylinders that do not cause interference of exhaust pulsation is introduced. And a second scroll portion into which exhaust gas discharged from another first cylinder different from the two first cylinders is introduced, and the first exhaust passage is connected to the first scroll portion. It is good also as having the 1st scroll part side channel | path and the 2nd scroll part side channel | path connected with the said 2nd scroll part.

  The intake / exhaust system of the internal combustion engine branches from the middle of the first scroll portion side passage to bypass the high-pressure stage supercharger, and between the high-pressure stage supercharger and the low-pressure stage supercharger. A bypass passage connected to the exhaust passage, and a second flow rate adjusting unit that adjusts the flow rate of the exhaust gas in the bypass passage may be further provided.

  According to the present invention, it is possible to appropriately recirculate exhaust gas from the exhaust passage to the intake passage while realizing high supercharging.

It is a schematic diagram which shows an example of a structure of the intake / exhaust system S which concerns on the 1st Embodiment of this invention. It is a schematic diagram which shows an example of a structure of the intake / exhaust system S which concerns on 2nd Embodiment.

<First Embodiment>
(Configuration of intake and exhaust system)
The configuration of an intake / exhaust system S for an internal combustion engine according to a first embodiment of the present invention will be described with reference to FIG.
FIG. 1 is a schematic diagram illustrating an example of a configuration of an intake / exhaust system S according to the first embodiment.

  The intake / exhaust system S is mounted on a vehicle having an engine which is an internal combustion engine. For example, the intake / exhaust system S is mounted on a large vehicle such as a bus or a truck. The intake / exhaust system S is a system that supplies intake air necessary for combustion of the engine to the engine and exhausts exhaust gas after combustion. As shown in FIG. 1, the intake / exhaust system S includes an engine 10, an intake passage 20, an exhaust passage 30, an EGR passage 40, a low-pressure supercharger 50, a high-pressure supercharger 60, and an ECU 80. Have

  The engine 10 is an engine including three or more cylinders, and is a four-cylinder diesel engine here. The engine 10 generates power by burning and expanding a mixture of fuel and intake air (air). The engine 10 includes an intake manifold 11 and cylinders 13a to 13d that are cylinder groups.

  The intake manifold 11 is a manifold connected to the intake passage 20 and branches the intake air (air) of the intake passage 20 into four cylinders 13a to 13d. The four cylinders 13a to 13d inhale intake air and exhaust exhaust gas after combustion. The cylinders 13a to 13d are each provided with a piston, an intake valve, an exhaust valve, an injector, and the like.

  In the four cylinders 13a to 13d, the ignition in the cylinder is performed in the order of the cylinder 13a, the cylinder 13c, the cylinder 13d, and the cylinder 13b, and the exhaust stroke is also performed in the order of the cylinder 13a, the cylinder 13c, the cylinder 13d, and the cylinder 13b. Thereby, the opening periods of the exhaust valves do not overlap in the cylinders 13a and 13d, and the opening periods of the exhaust valves do not overlap in the cylinders 13b and 13c. In such a case, even if the exhaust of the cylinder 13a and the exhaust of the cylinder 13d are merged in the exhaust passage 30, interference of exhaust pulsation does not occur. Similarly, even if the exhaust of the cylinder 13b and the exhaust of the cylinder 13c are merged in the exhaust passage 30, interference of exhaust pulsation does not occur.

  The intake passage 20 is a passage through which intake air (air) necessary for combustion of the engine 10 is sucked into the cylinders 13a to 13d. In the intake passage 20, from the upstream side toward the downstream side, the air cleaner 22, the compressor 52 of the low-pressure stage supercharger 50, the CAC (Charge Air Cooler) 23, the compressor of the high-pressure stage supercharger 60. 62, a CAC 24 and an intake throttle valve 25 are provided.

  The air cleaner 22 has a filter, for example, and removes foreign matter in the intake air. The compressor 52 of the low-pressure supercharger 50 compresses intake air that passes through the compressor 52 by rotating. The CAC 23 cools the intake air whose temperature has been increased by being compressed by the compressor 52 with a coolant or the atmosphere. The compressor 62 of the high-pressure supercharger 60 compresses intake air that passes through the compressor 62 by rotating. The CAC 24 cools the intake air that has been compressed by the compressor 62 and has risen in temperature with a coolant or the atmosphere. The intake throttle valve 25 adjusts the flow rate of intake air by adjusting the opening of the throttle valve.

  The exhaust passage 30 is a passage for discharging exhaust (exhaust gas) discharged from the engine 10 to the outside of the vehicle. The exhaust passage 30 includes a plurality of branched exhaust passages 31a to 31f and detour passages 33a and 33b. Further, the exhaust passage 30 includes a turbine 51 of the low pressure supercharger 50, a turbine 61 of the high pressure supercharger 60, an exhaust adjustment valve 34, detour adjustment valves 35 and 36, and an EAT 37 (Exhaust After-Treatment). : Exhaust aftertreatment device).

  The exhaust passage 31 a connects the cylinder 13 a of the engine 10 and the turbine 61 of the high-pressure supercharger 60, and guides the exhaust discharged from the cylinder 13 a to the turbine 61. The exhaust passage 31 b connects the cylinder 13 b and the turbine 61 and guides the exhaust discharged from the cylinder 13 b to the turbine 61. The exhaust passage 31 c connects the cylinder 13 c and the turbine 61, and guides the exhaust discharged from the cylinder 13 c to the turbine 61. The exhaust passage 31b and the exhaust passage 31c are configured to merge in the middle. On the other hand, the exhaust passage 31a does not merge with the exhaust passage 31b and the exhaust passage 31c.

  The exhaust passage 31d connects the cylinder 13d and the exhaust passage 31e located on the downstream side of the turbine 61 of the high-pressure supercharger 60. That is, the exhaust passage 31 d is a passage that bypasses the turbine 61. Thus, the exhaust discharged from the cylinder 13d is not guided to the turbine 61.

  The exhaust passage 31e connects the turbine 61 of the high pressure supercharger 60 and the turbine 51 of the low pressure supercharger 50. An exhaust passage 31d is connected in the middle of the exhaust passage 31e. For this reason, the exhaust discharged from the cylinder 13 d bypasses the turbine 61 and is guided to the turbine 51. A bypass passage 33a that bypasses the turbine 61 is connected to the exhaust passage 31e.

  The exhaust passage 31 f is a passage located on the downstream side of the turbine 51. In the middle of the exhaust passage 31f (upstream side of the EAT 37), a bypass passage 33b that bypasses the turbine 51 is connected.

  The bypass passage 33 a connects the exhaust passage 31 b and the exhaust passage 31 c (actually, the passage after the exhaust passage 31 b and the exhaust passage 31 c merge) and the exhaust passage 31 e on the downstream side of the turbine 61. . By providing the bypass passage 33a, the exhaust discharged from the cylinder 13b and the cylinder 13c can bypass the turbine 61.

  The bypass passage 33b connects the exhaust passage 31e (specifically, the connection point with the bypass passage 33a and the downstream side of the connection point with the exhaust passage 31d) and the exhaust passage 31f on the downstream side of the turbine 51. doing. By providing the bypass passage 33b, the exhaust gas flowing through the exhaust passage 31e can bypass the turbine 51.

  The exhaust adjustment valve 34 is provided in the middle of the exhaust passage 31d (specifically, downstream of the connection point with the EGR passage 40), and can adjust the pressure (exhaust pressure) and flow rate of the exhaust gas flowing through the exhaust passage 31d. Valve. In other words, the exhaust adjustment valve 34 functions as an exhaust pressure adjustment unit and a first flow rate adjustment unit. The exhaust adjustment valve 34 is, for example, a swing type open / close valve with an arm, and the exhaust pressure and the flow rate can be adjusted with high accuracy by adjusting the angle of the arm. As will be described in detail later, the exhaust adjustment valve 34 can also adjust the flow rate of the exhaust gas flowing through the EGR passage 40.

  The detour adjustment valve 35 is provided in the detour passage 33a and adjusts the flow rate of the exhaust gas (exhaust gas discharged from the cylinder 13b and the cylinder 13c) flowing through the detour passage 33a. The detour adjustment valve 35 is, for example, a gate valve. By adjusting the flow rate of the exhaust gas that flows through the bypass passage 33a, the flow rate of the exhaust gas that passes through the turbine 61 can also be adjusted. In the present embodiment, the detour adjustment valve 35 corresponds to the second flow rate adjustment unit.

  The detour adjustment valve 36 is provided in the detour passage 33b and adjusts the flow rate of exhaust gas (exhaust gas discharged from the cylinders 13a to 13d) flowing through the detour passage 33b. The detour adjustment valve 36 is, for example, a gate valve. By adjusting the flow rate of the exhaust gas that flows through the bypass passage 33b, the flow rate of the exhaust gas that passes through the turbine 51 can also be adjusted.

The EAT 37 is a device that purifies exhaust gas. For example, the EAT 37 collects PM in exhaust gas, or selectively reduces and purifies NO _x in exhaust gas using ammonia (NH ₃ ) generated by hydrolysis from urea water as a reducing agent.

  The EGR passage 40 is a recirculation passage that connects between the exhaust passage 31 d and the intake passage 20 and recirculates all or part of the exhaust discharged from the cylinder 13 d of the engine 10 to the intake passage 20. The EGR passage 40 is provided with an EGR cooler 41 and an EGR valve 42. The EGR cooler 41 cools the exhaust gas in the EGR passage 40. The EGR valve 42 adjusts the flow rate of the exhaust gas recirculated to the intake passage 20. The EGR valve 42 has a function of preventing the backflow of exhaust gas from the EGR passage 40 to the exhaust passage 31d.

The flow rate of the exhaust gas in the EGR passage 40 can be adjusted by the exhaust adjustment valve 34 described above. That is, by adjusting the flow rate of the exhaust gas flowing through the exhaust passage 31d by the exhaust adjustment valve 34, the flow rate of the exhaust gas flowing through the EGR passage 40 can also be adjusted. Further, by adjusting the exhaust pressure of one exhaust passage 31d connected to the EGR passage 40 with the exhaust adjustment valve 34, it is possible to prevent the exhaust pressure from becoming excessive with respect to the intake pressure in the intake passage 20. Therefore, the exhaust gas can be appropriately recirculated to the intake passage 20.
Further, by adjusting the intake throttle valve 25 of the intake passage 20 in addition to the exhaust adjustment valve 34 and the EGR valve 42, the exhaust gas recirculation to the intake passage 20 can be controlled with high accuracy. Note that the exhaust gas recirculation amount may be controlled by selecting at least one of the exhaust adjustment valve 34, the EGR valve 42, and the intake throttle valve 25 in accordance with the rotation region of the engine 10.

  The low pressure supercharger 50 and the high pressure supercharger 60 are devices that supercharge intake air taken into the engine 10. Specifically, after the low-pressure supercharger 50 supercharges intake air, the high-pressure supercharger 60 further supercharges intake air. Thereby, highly compressed intake air is supplied to the engine 10, and the displacement of the engine 10 can be substantially increased. Here, the low-pressure stage supercharger 50 and the high-pressure stage supercharger 60 are turbochargers that use the exhaust pressure as a power source.

  The low-pressure supercharger 50 includes a connecting shaft 53 that connects the turbine 51 and the compressor 52 in addition to the turbine 51 and the compressor 52 described above. In the low-pressure stage turbocharger 50, the turbine 51 rotates by receiving the energy of the exhaust gas that passes through, so that the compressor 52 connected to the turbine 51 via the connection shaft 53 rotates and sucks the intake air from the intake passage 20. Supercharge. Similarly, the high-pressure supercharger 60 also has a connecting shaft 63 that connects the turbine 61 and the compressor 62. The turbine 61 rotates by receiving the energy of the exhaust gas that passes therethrough, whereby the compressor 62 rotates and the intake air flows. The intake air in the passage 20 is supercharged.

  In the present embodiment, the high-pressure supercharger 60 is a twin scroll turbocharger having two scroll portions through which exhaust passes. Specifically, a first scroll part 61b and a second scroll part 61c are provided in the housing 61a of the turbine 61 of the high-pressure supercharger 60. In FIG. 1, for convenience of explanation, the housing of the compressor 62 of the high-pressure supercharger 60 and the housing of the turbine 51 and the compressor 62 of the low-pressure supercharger 50 are not shown.

  The first scroll portion 61b is connected to the exhaust passage 31b and the exhaust passage 31c (first scroll portion side passage), and the second scroll portion 61c is connected to the exhaust passage 31a (second scroll portion side passage). For this reason, the exhaust discharged from the cylinders 13b and 13c whose exhaust pulsation does not interfere with each other is introduced into the first scroll part 61b, and the exhaust discharged from the cylinder 13c is introduced into the second scroll part 61c. As a result, the turbine 61 rotates using the exhaust discharged from the three cylinders 13a to 13c among the four cylinders 13a to 13d as a power source.

  On the other hand, in addition to the exhaust of the cylinders 13 a to 13 c that have passed or bypassed the turbine 61, the turbine 61 is added to the low-pressure supercharger 50 in which the turbine 51 is located downstream of the turbine 61 of the high-pressure supercharger 60. The exhaust of the cylinder 13d that bypasses is also introduced. For this reason, the turbine 51 rotates using the exhaust discharged from the four cylinders 13a to 13d as a power source. As a result, the operating efficiency of the low-pressure stage supercharger 50 can be increased.

  In the exhaust passage 31e, the exhaust that has passed through the high-pressure supercharger 60 (exhaust from the cylinders 13a to 13c) and the exhaust that has flowed through the exhaust passage 31d (exhaust from the cylinder 13d) merge. Since the dynamic pressure of the exhaust gas that has passed through the high-pressure supercharger 60 is small, interference of exhaust pulsation in the exhaust passage 31e can be suppressed.

  As described above, the exhaust from the cylinders 13a to 13c is introduced into the high-pressure supercharger 60 through the exhaust passages 31a to 31c, and the exhaust from the cylinder 13d is introduced into the low-pressure supercharger 50 through the exhaust passages 31d and 31e. Therefore, the cylinders 13a to 13c correspond to the first cylinder, the cylinder 13d corresponds to the second cylinder, the exhaust passages 31a to 31c correspond to the first exhaust passage, and the exhaust passages 31d and 31e correspond to the second exhaust passage. Applicable.

  The ECU 80 is an electronic control unit (Electric Control Unit) including a microcomputer having a CPU, a ROM, a RAM, and the like. The ECU 80 controls the operation of each device described above. For example, the ECU 80 controls operations of the intake throttle valve 25, the exhaust adjustment valve 34, the detour adjustment valves 35 and 36, and the EGR valve 42.

(Effect in the first embodiment)
The intake / exhaust system S described above introduces the exhaust of the cylinders 13a to 13c into the high pressure supercharger 60 via the exhaust passages 31a to 31c not connected to the EGR passage 40, and is connected to the EGR passage 40 and connected to the EGR passage 40. Exhaust gas from the cylinder 13d is introduced into the low-pressure stage supercharger 50 through an exhaust passage 31d that bypasses the feeder 60.
Thereby, since the exhaust of the three cylinders 13a to 13c is stably introduced into the high-pressure supercharger 60, the operating efficiency of the high-pressure supercharger 60 can be increased. Further, since only the exhaust passage 31 d is connected to the EGR passage 40, the exhaust of the exhaust passage 30 with respect to the pressure of the intake air in the intake passage 20 compared to the case where a plurality of exhaust passages are connected to the EGR passage 40. Therefore, the exhaust gas can be properly recirculated to the intake passage 20. Further, since the exhaust gas that is not recirculated to the EGR passage 40 is introduced into the low-pressure supercharger 50, the operating efficiency of the low-pressure supercharger 50 can be increased. As a result, it is possible to appropriately recirculate exhaust gas to the intake passage 20 while realizing high supercharging.

<Second Embodiment>
FIG. 2 is a schematic diagram illustrating an example of the configuration of the intake / exhaust system S according to the second embodiment.
In the first embodiment, the high pressure supercharger 60 is a twin scroll turbocharger having a first scroll part 61b and a second scroll part 61c, whereas the high pressure supercharger according to the second embodiment. The feeder 60 is different in that it has one scroll part. Note that description of the same configuration as in the first embodiment is omitted.

  As shown in FIG. 2, the exhaust passage 31a connected to the cylinder 13a, the exhaust passage 31b connected to the cylinder 13b, and the exhaust passage 31c connected to the cylinder 13c merge in the middle, and the scroll portion of the turbine 61 61d is connected. For this reason, the exhaust of the cylinders 13 a to 13 c is introduced into the turbine 61. In the case of the twin scroll type turbocharger, it is necessary to provide a partition in the housing of the turbine 61. However, in the case of the second embodiment, since it is not necessary to provide a partition, the turbine 61 can be downsized. .

  Also in the second embodiment, similarly to the first embodiment, the exhaust of the cylinders 13a to 13c is introduced into the high-pressure supercharger 60 via the exhaust passages 31a to 31c that are not connected to the EGR passage 40, and EGR is performed. Exhaust gas from the cylinder 13 d is introduced into the low-pressure supercharger 50 through an exhaust passage 31 d connected to the passage 40. For this reason, it becomes possible to appropriately recirculate exhaust gas to the intake passage 20 while realizing high supercharging.

  In the above description, the engine 10 is a diesel engine. However, the present invention is not limited to this. For example, the engine 10 may be a gasoline engine. In the above description, the engine 10 has four cylinders. However, the present invention is not limited to this. For example, the engine 10 may have three or six cylinders.

  As mentioned above, although this invention was demonstrated using embodiment, the technical scope of this invention is not limited to the range as described in the said embodiment. It will be apparent to those skilled in the art that various modifications or improvements can be added to the above embodiment. It is apparent from the scope of the claims that the embodiments added with such changes or improvements can be included in the technical scope of the present invention.

DESCRIPTION OF SYMBOLS 10 Engine 13a-13d Cylinder 20 Intake passage 30 Exhaust passage 31a-31f Exhaust passage 33a, 33b Detour passage 34 Exhaust adjustment valve 35, 36 Detour adjustment valve 40 EGR passage 50 Low pressure stage supercharger 51 Turbine 52 Compressor 60 High pressure stage supercharge Machine 61 Turbine 61b First scroll part 61c Second scroll part 62 Compressor S Intake / exhaust system

Claims (5)

A cylinder group provided in the internal combustion engine and including three or more cylinders;
An intake passage for introducing intake air into the cylinder group;
A low-pressure supercharger and a high-pressure supercharger that compress the intake air;
A first exhaust passage for introducing exhaust discharged from each of the plurality of first cylinders of the cylinder group into the high-pressure supercharger;
Exhaust gas provided from a second cylinder different from the first cylinder in the cylinder group is provided downstream of the high-pressure supercharger. A second exhaust passage to be introduced into the low-pressure stage supercharger;
A recirculation passage that connects between the second exhaust passage and the intake passage and recirculates the exhaust discharged from the second cylinder to the intake passage;
An intake / exhaust system for an internal combustion engine, comprising: In the second exhaust passage, provided further downstream than a connection point with the recirculation passage, the exhaust passage further includes an exhaust pressure adjusting unit that adjusts an exhaust pressure in the second exhaust passage.
The intake / exhaust system for an internal combustion engine according to claim 1. The second exhaust passage further includes a first flow rate adjusting unit that is provided on the downstream side of a connection point with the return passage and adjusts the flow rate of the exhaust gas in the return passage.
The intake / exhaust system for an internal combustion engine according to claim 1 or 2. The plurality of first cylinders are three first cylinders,
The high-pressure turbocharger includes a first scroll portion into which exhaust gas discharged from two first cylinders that do not cause exhaust pulsation interference, and another first cylinder different from the two first cylinders. A second scroll part into which exhausted exhaust is introduced,
The first exhaust passage includes a first scroll portion side passage connected to the first scroll portion and a second scroll portion side passage connected to the second scroll portion,
The intake / exhaust system for an internal combustion engine according to any one of claims 1 to 3. A bypass passage that branches from the middle of the first scroll portion side passage and bypasses the high-pressure supercharger, and is connected to an exhaust passage between the high-pressure supercharger and the low-pressure supercharger; ,
A second flow rate adjusting unit that adjusts the flow rate of the exhaust gas in the bypass passage,
The intake / exhaust system for an internal combustion engine according to claim 4.

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