JP2020084874A - Silencer device for supercharger - Google Patents

Abstract

To provide a silencer device for a supercharger which allows for suppression of the wear and damage of the supercharger into which an EGR gas and air are introduced.SOLUTION: The silencer device for a supercharger comprises a silencer element, a casing and an EGR gas introduction pipe. The casing includes a first sidewall and a second sidewall which is arranged at a position closer to compressor housing side than the first sidewall in an axial direction, and which forms an atmospheric air introduction space between the first sidewall and the second sidewall. The EGR gas introduction pipe extends along the axial direction in the atmospheric air introduction space, and has an outflow port formed in the atmospheric air introduction port. An opening area A1 of an opening in the casing which is formed between an end part of the EGR gas introduction pipe at an outflow port side, and an end part of the second sidewall at an internal peripheral side is constituted in such a way that a flow speed difference between a flow speed V1 of air when air having a design flow rate passes through the opening in the casing and a flow speed V2 of an EGR gas when the EGR gas having a design flow rate passes through the outflow port reaches a prescribed value or smaller so that the flow speed V1 and the flow speed V2 match with each other.SELECTED DRAWING: Figure 3

Description

The present disclosure relates to a silencer device for a supercharger, which is provided on the intake inlet side of a compressor housing of the supercharger.

As a large turbocharger mounted on a marine diesel engine or a land power diesel engine, a cylindrical silencer is connected to the intake inlet side of a compressor housing (compressor casing) and sucked from the outer peripheral side of the silencer. A structure is known in which air is introduced into the intake inlet of a compressor housing (Patent Document 1).

In Patent Document 1, an inlet for introducing EGR gas is opened at the end surface of the silencer on the side opposite to the compressor side, and a frustoconical mixing means having one end opened so as to cover the inlet is provided. It is disclosed that the inside of the silencer is divided into the inside and the outside of the mixing means. Further, in Patent Document 1, the EGR gas introduced into the mixing member from the inlet passes through a plurality of holes formed in the outer peripheral surface of the mixing means and mixes with air outside the outer peripheral surface of the mixing member. Is disclosed. The other end of the mixing means in Patent Document 1 is not open.

JP, 2005-194163, A

In the invention described in Patent Document 1, an air-fuel mixture in which air (fresh air) and EGR gas are uniformly mixed is introduced into the inner peripheral side and the outer peripheral side of the compressor (impeller) in the supercharger. Here, the EGR gas introduced into the compressor may contain condensed water generated by mixing with air (fresh air). Further, the EGR gas is cleaned by the exhaust gas cleaning device on the upstream side, but foreign matter such as particulate matter (PM) such as soot may remain. Further, since the peripheral speed of the outer peripheral side of the compressor is higher than that of the inner peripheral side, the impact force when the condensed water or the foreign matter collides becomes large, and abrasion or damage due to the collision of the condensed water or the foreign matter is likely to occur. In the invention described in Patent Document 1, since the air-fuel mixture containing EGR gas is introduced to the outer peripheral side of the compressor, condensed water and foreign matter contained in the air-fuel mixture collide with the outer peripheral side of the compressor, resulting in wear of the compressor. Or damage may occur.

In view of the above-mentioned circumstances, an object of at least one embodiment of the present invention is to provide a silencer device for a supercharger capable of suppressing wear and damage of the supercharger into which EGR gas and air (fresh air) are introduced. Especially.

(1) A silencer device for a supercharger according to at least one embodiment of the present invention,
A silencer device for a supercharger, which is provided on the intake inlet side of a compressor housing of the supercharger,
Silencer element,
A housing that houses the silencer element and that is configured to introduce air and EGR gas;
An EGR gas introduction pipe for introducing the EGR gas into the housing,
The housing is
A first side wall extending in a direction intersecting the axial direction of the supercharger and having a central side opening;
A second side wall that is provided closer to the compressor housing than the first side wall in the axial direction and forms an outside air introduction space between the first side wall and the second side wall;
On the outer peripheral side of the outside air introducing space, an outer peripheral side opening for introducing the air into the outside air introducing space is formed,
The EGR gas introduction pipe is an outlet portion that is disposed inside the housing and extends in the outside air introduction space along the axial direction, and the central side opening is on one end side of the outlet portion. An outlet part having an inlet part communicating with the outlet part and an outlet part formed on the other end side of the outlet part,
The opening area A1 of the opening in the housing formed between the end portion on the outlet side of the outlet portion and the end portion on the inner peripheral side of the second side wall is equal to the design flow rate of the opening in the housing. Between the flow velocity V1 and the flow velocity V2 so that the flow velocity V1 of the air when the air passes and the flow velocity V2 of the EGR gas when the EGR gas of a design flow rate passes through the outlet are aligned. The difference in the flow velocities is less than or equal to a predetermined value.

According to the configuration of (1) above, the EGR gas flowing out from the outlet of the EGR gas introduction pipe flows along the axial direction in the outside air introduction space, and the inner peripheral side near the rotation center of the compressor of the supercharger. Mainly introduced in. The air introduced into the outside air introduction space from the outer peripheral side opening flows along the outer peripheral side of the EGR gas along the axial direction, and therefore is mainly introduced to the outer peripheral side away from the rotation center of the compressor.

Since the relatively high temperature EGR gas introduced into the inner peripheral side of the compressor mixes with the air having a temperature lower than that of the EGR gas introduced into the outer peripheral side of the compressor, condensed water is generated around the area where the EGR gas and air are in contact with each other. It may occur. Here, the EGR gas may contain foreign matter such as particulate matter (PM) as compared with air. Further, since the peripheral speed of the outer peripheral side of the compressor is higher than that of the inner peripheral side, abrasion or damage due to collision of foreign matter such as condensed water is likely to occur. In the silencer device for the supercharger described above, since foreign matter such as condensed water is introduced to the inner peripheral side of the compressor, it is possible to suppress the collision of the foreign matter on the outer peripheral side of the compressor, which in turn suppresses wear and damage of the compressor. can do.

Further, the present inventors have found that the generation of condensed water due to the mixing of EGR gas and air can be suppressed by making the flow rates of EGR gas and air flowing through the outside air introduction space uniform.
According to the configuration of (1) above, the opening area A1 of the opening in the housing is determined by the flow velocity V1 of the air when the air having the design flow rate passes through the opening in the housing and the EGR gas having the design flow rate passing through the outlet. The flow velocity difference between the flow velocity V1 and the flow velocity V2 is set to be equal to or less than a predetermined value so that the flow velocity V2 of the EGR gas becomes uniform. In this case, since the flow velocity difference between the air passing through the opening in the housing and the EGR gas passing through the outlet of the EGR gas introduction pipe can be reduced, the flow velocity of the EGR gas and the air flowing through the outside air introduction space with respect to each other. Can be arranged. By making the flow velocities of the EGR gas and the air flowing through the outside air introduction space uniform, it is possible to suppress the generation of vortices when the EGR gas and the air collide with each other, and consequently to generate the condensed water by mixing the EGR gas and the air. Can be suppressed. By suppressing the generation of the condensed water, it is possible to suppress the condensed water from colliding with the compressor, and it is possible to suppress the wear and damage of the compressor (supercharger).

(2) In some embodiments, in the configuration of (1) above,
The opening area A1 is configured such that the flow velocity V1 and the flow velocity V2 are equal in velocity.

According to the above configuration (2), the flow velocity V1 of the air when passing through the opening inside the casing and the flow velocity V2 of the EGR gas when passing through the opening on the outlet side are equal in the opening area A1 of the opening inside the casing. With such a configuration, the flow velocity difference between the flow velocity V1 and the flow velocity V2 can be reduced, so that the generation of condensed water due to the mixing of EGR gas and air can be more effectively suppressed.

(3) In some embodiments, in the configuration of (1) above,
The EGR gas introduction pipe has at least one straightening plate provided inside the outlet portion.

According to the above configuration (3), the EGR gas flowing through the outlet of the EGR gas introduction pipe is rectified by the rectifying plate, so that the EGR gas flowing out from the outlet of the EGR gas introduction pipe and the outside air introduced from the outer peripheral side opening. It is possible to reduce the flow velocity difference between the air introduced into the space.

(4) In some embodiments, in the configuration of (3), the EGR gas introducing pipe includes a plurality of openings inside the outlet, the openings being partitioned by the at least one straightening plate. Each of the openings is configured to have the same opening area.

According to the above configuration (4), the plurality of openings of the EGR gas introduction pipe are configured to have the same opening area, so that the EGR gas flowing through each of the plurality of openings is The flow velocity can be made uniform. By equalizing the flow velocity of the EGR gas flowing through each of the plurality of openings, it is possible to prevent the EGR gas flowing out of each of the outlets of the plurality of openings and flowing through the outside air introduction space from becoming a turbulent flow. By preventing the EGR gas flowing through the outside air introduction space from becoming a turbulent flow, it is possible to prevent the EGR gas flowing through the outside air introduction space from colliding with the air to generate a vortex, and thus the EGR gas and the air. Generation of condensed water due to mixing with can be suppressed.

(5) In some embodiments, in the configuration according to any one of (1) to (4) above,
The EGR gas introduction pipe is an inlet portion that is arranged outside the housing and has a bent portion, and further includes an inlet portion that communicates with the central opening.
An outer peripheral wall of the outlet portion connected to the outer peripheral side of the curved portion is formed longer in the axial direction than an inner peripheral wall of the outlet portion connected to the inner peripheral side of the curved portion.

The EGR gas that has passed through the curved portion has a flow direction that swells to the outer peripheral side of the curved portion. If the flow direction of the EGR gas is not corrected in the axial direction in the EGR gas introducing pipe, the EGR gas flowing on the outer peripheral side in the flow direction of the EGR gas flows out from the outlet and then collides with the air. When the EGR gas and the air collide with each other, a vortex is generated, and the vortex promotes the mixing of the EGR gas and the air, so that the generation of the condensed water is promoted.

According to the configuration of (5) above, by forming the outer peripheral wall located on the outer peripheral side in the EGR gas flow direction longer than the inner peripheral wall located on the inner peripheral side in the EGR gas flow direction, the EGR gas introduction pipe The flow direction of EGR gas flowing on the outer peripheral side can be corrected by the outer peripheral wall to the direction along the axial direction. Therefore, it is possible to mitigate the collision between the EGR gas flowing on the outer peripheral side in the flow direction of the EGR gas and the air. By alleviating the collision between the EGR gas and the air, it is possible to suppress the generation of condensed water.

(6) In some embodiments, in the configuration of (3) above,
The EGR gas introduction pipe is an inlet portion that is arranged outside the housing and has a bent portion, and further includes an inlet portion that communicates with the central opening.
The at least one current plate extends along a direction orthogonal to the cross section when the cross section along the axial direction and the centerline of the bent portion is visually recognized.

As described above, the EGR gas that has passed through the curved portion has a flow direction in which the EGR gas swells to the outer peripheral side of the curved portion. If the straightening plate extending along the direction orthogonal to the cross section is not provided, the flow direction of the EGR gas is not corrected in the EGR gas introduction pipe to the direction along the axial line, and thus the EGR gas is not corrected. After the EGR gas flowing on the outer peripheral side in the flow direction of 1 flows out from the outlet, it collides with air.
According to the above configuration (6), since the rectifying plate is provided so as to separate the outer peripheral side and the inner peripheral side in the EGR gas flow direction, the EGR gas flow direction in the EGR gas introduction pipe is set to the axial direction. It can be modified along the direction. By correcting the flow direction of the EGR gas, the collision between the EGR gas and the air can be mitigated. By alleviating the collision between the EGR gas and the air, it is possible to suppress the generation of condensed water.

(7) In some embodiments, in the configurations of (1) to (4) above,
A drain receiver arranged in the outer peripheral side opening is further provided.
According to the configuration of (7) above, the condensed water generated when the EGR gas and the air merge in the outside air introduction space can be stored in the drain receiver arranged in the outer peripheral side opening. Therefore, the condensed water can be prevented from being introduced into the supercharger, so that the corrosion and damage of the supercharger due to the condensed water can be suppressed.

(8) The supercharger according to at least one embodiment of the present invention is equipped with the silencer device for a supercharger according to any of (1) to (4) above.
According to the above configuration, it is possible to suppress wear and damage of the compressor (supercharger) into which EGR gas and air are introduced.

(9) An engine according to at least one embodiment of the present invention is equipped with the supercharger described in (8) above.
According to the above configuration, it is possible to suppress wear and damage of the compressor (supercharger) into which EGR gas and air are introduced.

According to at least one embodiment of the present invention, there is provided a silencer device for a supercharger capable of suppressing wear and damage of the supercharger into which EGR gas and air are introduced.

It is a schematic structure figure showing roughly the composition of the diesel engine for ships provided with the silencer device for superchargers concerning one embodiment of the present invention. It is a schematic sectional drawing of a silencer device for superchargers concerning one embodiment of the present invention, and a supercharger. 1 is a schematic partially enlarged cross-sectional view showing a silencer device for a supercharger and a part of the supercharger according to an embodiment of the present invention in an enlarged manner. It is a schematic partial expanded sectional view which expands and shows a silencer device for superchargers concerning one other embodiment of the present invention, and a part of supercharger. It is a figure for demonstrating the drain receiving and drain discharge apparatus in one Embodiment of this invention, Comprising: It is a schematic partial expanded sectional view which expands and shows a silencer apparatus for superchargers, and a part of supercharger. It is the figure which looked at the silencer device for superchargers shown in FIG. 5 from the arrow B direction in FIG.

Hereinafter, some embodiments of the present invention will be described with reference to the accompanying drawings. However, the dimensions, materials, shapes, relative positions, and the like of the components described as the embodiments or shown in the drawings are not intended to limit the scope of the present invention thereto, but are merely illustrative examples. Absent.
For example, the expressions representing relative or absolute arrangements such as "in a certain direction", "along a certain direction", "parallel", "orthogonal", "center", "concentric", or "coaxial" are strict. In addition to representing such an arrangement, it also represents a state in which the components are relatively displaced by a tolerance or an angle or a distance at which the same function can be obtained.
For example, expressions such as "identical", "equal", and "homogeneous" that indicate that they are in the same state are not limited to a state in which they are exactly equal to each other. It also represents the existing state.
For example, the representation of a shape such as a quadrangle or a cylinder does not only represent a shape such as a quadrangle or a cylinder in a geometrically strict sense, but also an uneven portion or a chamfer within a range in which the same effect can be obtained. The shape including parts and the like is also shown.
On the other hand, the expressions “comprising”, “including”, or “having” one element are not exclusive expressions that exclude the existence of other elements.
Note that the same configurations are denoted by the same reference numerals, and description thereof may be omitted.

FIG. 1 is a schematic configuration diagram schematically showing a configuration of a marine diesel engine including a silencer device for a supercharger according to an embodiment of the present invention.
As shown in FIG. 1, the silencer device 4 for a supercharger is mounted on a diesel engine 1 for a ship (internal combustion engine for a ship) together with the supercharger 3.

As shown in FIG. 1, the diesel engine 1 includes a supercharger 3, a supercharger silencer device 4, a diesel engine (hereinafter referred to as an engine 10), and an exhaust gas E emitted from the engine 10. Part for recirculating the part as EGR gas to the upstream side of the supercharger 3 (compressor 31 described later), an exhaust gas treatment device 12 for removing harmful substances from the EGR gas, and a combustion gas C for sending to the engine 10. And an exhaust passage 14 for exhausting the exhaust gas E from the engine 10.
Examples of the engine 10 include a main engine (main engine for ships) that drives a propulsion device (not shown) that propels a ship equipped with the diesel engine 1.

As shown in FIG. 1, the supercharger silencer device 4 is provided upstream of the supercharger 3 (compressor 31) in the intake passage 13.
In the embodiment shown in FIG. 1, an air cleaner 15 for removing dust and the like from the air A is provided in the intake passage 13 upstream of the silencer device 4 for the supercharger. An air cooler 16 that cools the combustion gas C that has been compressed by the compressor 31 and has risen in temperature is provided downstream of the compressor 31 in the intake passage 13.

As shown in FIG. 1, the exhaust gas treatment device 12 is provided downstream of the supercharger 3 (a turbine 32 described later) in the exhaust flow path 14. Examples of the exhaust gas treatment device 12 include a scrubber that injects a cleaning liquid into the exhaust gas to remove harmful substances such as particulate matter (PM) and sulfur oxides (SOx) in the exhaust gas.

The exhaust flow path 14 is branched downstream of the turbine 32 and upstream of the exhaust gas treatment device 12, and a part of the exhaust gas E discharged from the engine 10 is discharged to the atmosphere from a stack (not shown). To be done.

The EGR device 11 includes an EGR flow path 17, as shown in FIG.
The EGR flow path 17 is connected to a downstream side outlet of the exhaust gas treatment device 12 and also connected to an upstream side inlet of the supercharger silencer device 4.
Of the exhaust gas E discharged from the engine 10, the exhaust gas that flows through the EGR flow path 17 and is returned to the silencer device 4 for the supercharger without being discharged to the atmosphere from a stack (not shown) is the above-mentioned EGR gas.

In the embodiment shown in FIG. 1, the EGR flow path 17 is provided with an EGR cooler 18 and an EGR valve 19.
When the EGR valve 19 closes the EGR flow path 17, the air A sent to the supercharger 3 after passing through the air cleaner 15 and the supercharger silencer device 4 becomes the combustion gas C described above. Further, when the EGR valve 19 opens the EGR passage 17, the EGR gas sent to the supercharger 3 after passing through the EGR passage 17 and the supercharger silencer device 4 and the air A are included. The mixture becomes the combustion gas C described above.

As the supercharger 3, as shown in FIG. 1, a turbocharger 3A including a compressor 31 provided in the intake passage 13 of the engine 10 and a turbine 32 provided in the exhaust passage 14 of the engine 10 can be cited. Be done.

FIG. 2 is a schematic cross-sectional view of a supercharger silencer device and a supercharger according to an embodiment of the present invention.
As shown in FIG. 2, the turbocharger 3A includes a rotor 33 (rotating shaft) having a longitudinal direction along the axial direction (the horizontal direction in FIG. 2) and the above-described compressor provided at one end of the rotor 33 in the longitudinal direction. 31, a turbine 32 (turbine rotor blade) described above provided at the other longitudinal end of the rotor 33, a bearing 34 that rotatably supports the rotor 33, a compressor housing 35 that houses the compressor 31, and a turbine 32. A turbine housing 36 that stores the bearing 34 and a bearing housing 37 that stores the bearing 34 that is disposed between the compressor housing 35 and the turbine housing 36 in the axial direction are provided.
Hereinafter, the axial direction of the turbocharger 3A (the direction in which the axis CA of the rotor 33 extends) may be simply abbreviated as the axial direction.

As shown in FIG. 2, the compressor housing 35 has a shroud portion 353, a diffuser 354, and a compressor passage 355 formed therein.
The diffuser 354 is arranged along the radial direction (direction orthogonal to the axial direction) on the outer peripheral side of the compressor 31 and on the side away from the intake inlet 351 in the axial direction (horizontal direction in FIG. 2) (right side in the same figure). Have been extended.
The compressor passage 355 is formed in a spiral shape on the outer peripheral side of the diffuser 354.
The shroud portion 353 is provided so as to cover the compressor 31, and is formed so as to be continuous with the intake inlet 351 side of the diffuser 354 and the inner peripheral side of the diffuser 354 in the axial direction.

As shown in FIG. 2, the compressor 31 includes a hub 311 and a plurality of blades 312.
The hub 311 has a conical shape in which the outer dimension gradually increases in the axial direction (left-right direction in FIG. 2) toward the side (right side in the figure) away from the side near the intake inlet 351 (left side in the figure). It is formed into a shape.
The plurality of blades 312 are provided so as to project radially outward from the outer circumference of the hub 311. Further, the plurality of blades 312 are close to the shroud portion 353 of the compressor housing 35 with a minute clearance (tip clearance) therebetween.

As shown in FIG. 2, the high-temperature exhaust gas E discharged from the engine 10 is introduced from an exhaust inlet 361 formed in the turbine housing 36 and sent to the turbine 32, so that the turbine 32 has an axis line of the rotor 33. It is rotationally driven with CA as the center of rotation. The exhaust gas E that rotationally drives the turbine 32 is discharged from an exhaust outlet 362 formed in the turbine housing 36.

As shown in FIG. 2, since the compressor 31 is connected to the turbine 32 via the rotor 33, the compressor 31 is rotationally driven about the axis CA as the center of rotation in synchronization with the rotation of the turbine 32. The combustion gas C is sucked from the intake inlet 351 of the compressor housing 35 by the rotational driving of the compressor 31. The sucked combustion gas C flows in the intake air introduction space 352 formed inside the compressor housing 35 along the axial direction.

The combustion gas C introduced into the compressor housing 35 flows between the plurality of blades 312 of the compressor 31 that is rotationally driven to increase the dynamic pressure, and then flows into the diffuser 354 located outside in the radial direction. Then, a part of the dynamic pressure is converted into static pressure and the pressure is increased, and then is fed into the combustion chamber of the engine 10 through the compressor flow path 355 and the intake outlet 356.

FIG. 3 is a schematic partially enlarged cross-sectional view showing a silencer device for a supercharger according to an embodiment of the present invention and a part of the supercharger in an enlarged manner.
As shown in FIG. 3, the supercharger silencer device 4 is provided on the intake inlet 351 side of the compressor housing 35.

As shown in FIG. 3, the silencer device 4 for the supercharger includes a silencer element 41 (sound absorbing material), a housing 42, and an EGR gas introduction pipe 7.
The silencer element 41 is configured to reduce noise of the turbocharger 3A.
The housing 42 houses the silencer element 41, and is configured to introduce the air A and the EGR gas.
The EGR gas introduction pipe 7 is provided to introduce the EGR gas into the housing 42. Further, the EGR gas introduction pipe 7 includes an outlet portion 8 arranged inside the housing 42.

As shown in FIG. 3, the housing 42 includes a first side wall 5 and a second side wall 6. As shown in FIG. 3, the second side wall 6 is provided closer to the compressor housing 35 side (right side in the drawing) than the first side wall 5 in the axial direction, and is located between the first side wall 5 and the outside air introducing space 40. Is formed. An outer peripheral side opening 401 for introducing the air A into the outside air introducing space 40 is formed on the outer peripheral side of the outside air introducing space 40.
In the embodiment shown in FIG. 3, each of the first side wall 5 and the second side wall 6 has an annular shape extending along a direction intersecting the axial direction (the horizontal direction in the drawing) (the vertical direction in the drawing, etc.). It is a flat plate.

As shown in FIG. 3, a first center side opening 51 (center side opening) for introducing the EGR gas into the outside air introducing space 40 is formed on the inner peripheral side of the first side wall 5. On the other hand, a second center side opening 61 for introducing the EGR gas and the air A into the intake air introducing space 352 of the compressor housing 35 is formed on the inner peripheral side of the second side wall 6. The intake air introduction space 352 is a space formed in the compressor housing 35 on the upstream side of the compressor 31 in the flow direction of the combustion gas C, and communicates with the intake air inlet 351.
In the embodiment shown in FIG. 3, the first center side opening 51 and the second center side opening 61 are open in a circular shape.

In the embodiment shown in FIG. 3, the cylindrical body 43 provided concentrically with the second side wall 6 is connected to the inner peripheral side of the second side wall 6 and extends toward the compressor housing 35 side along the axial direction. is doing. At the end of the cylindrical body 43 on the compressor housing 35 side, a flange 44 that protrudes outward along a direction orthogonal to the axial direction is provided. The cylindrical body 43 and the flange 44 are integrally provided on the second side wall 6. The flange 44 is fixed to the compressor housing 35 while being in contact with the outer surface 357 of the compressor housing 35 on the intake inlet 351 side.

As shown in FIG. 3, the outlet portion 8 of the EGR gas introduction pipe 7 is formed in a tubular shape extending in the outside air introduction space 40 along the axial direction (left and right direction in the drawing) of the turbocharger 3A. The inflow port 81 is formed on the end face on one end side (first side wall 5 side, left side in the drawing) in the axial direction, and the flow inlet 81 flows on the end face on the other end side (second side wall 6 side, right side in the drawing) in the axial direction. An outlet 82 is formed. The inflow port 81 communicates with the first center side opening 51 of the first side wall 5.
In the embodiment shown in FIG. 3, a hole penetrating the peripheral surface of the outlet portion 8 of the EGR gas introduction pipe 7 is not formed, and all the EGR gas flowing from the inflow port 81 is discharged from the outflow port 82. To be done.

In the embodiment shown in FIG. 3, the outlet portion 8 of the EGR gas introduction pipe 7 includes a first tubular portion 84 and a flange portion 85.
The first tubular portion 84 is provided inside the housing 42 and is formed in a tubular shape extending along the axial direction.
The flange portion 85 is provided concentrically with the first tubular portion 84, and the outer peripheral side portion thereof extends outwardly in the radial direction (vertical direction in the drawing, etc.) from the first center-side opening 51.
When visually recognizing the cross section (cross section along the axial direction) as shown in FIG. 3, the outlet portion 8 of the EGR gas introducing pipe 7 is in the axial direction of the outer peripheral wall 88 located on the upper side in the figure with respect to the axial line CA. The length (in the left-right direction in the drawing) is equal to the length in the axial direction of the inner peripheral wall 89 located on the lower side in the drawing with respect to the axis CA.

In the embodiment shown in FIG. 3, in the outlet portion 8 of the EGR gas introduction pipe 7, the first tubular portion 84 is inserted into the first center side opening 51 of the first side wall 5, and the inflow port 81 is the first center side. It is fixed to the housing 42 in a state of communicating with the opening 51.

More specifically, a disc-shaped flange 21 is fixed to the inner peripheral side of the first side wall 5 and the surface opposite to the side facing the second side wall 6.
The flange portion 85 is bolted to the flange 21 by the bolt 45 in a state where the outer peripheral portion is in contact with the flange 21 from the outside. Therefore, the outlet portion 8 of the EGR gas introduction pipe 7 is configured to be connectable to and detachable from the housing 42.

Further, the screw holes to be screwed into the bolts 45 are provided at a plurality of places at regular intervals in the circumferential direction of the flange 21, and the insertion holes for inserting the shaft portions of the bolts 45 are the screw holes of the flange 21. Correspondingly, the flange portion 85 is provided at a plurality of locations on the outer peripheral side portion at regular intervals in the circumferential direction. Therefore, the outlet portion 8 of the EGR gas introduction pipe 7 is configured so that the mounting angle in the circumferential direction with respect to the housing 42 can be changed.

As shown in FIG. 3, the EGR gas is introduced into the outlet portion 8 of the EGR gas introduction pipe 7 through the first center side opening 51 and the inflow port 81, flows out from the outflow port 82, and enters the outside air introduction space. After flowing in the axial direction in 40, it is introduced into the intake air introducing space 352. The air A is introduced into the outside air introduction space 40 through the outer peripheral side opening 401, flows along the outer peripheral side of the EGR gas along the axial direction, and then is introduced into the intake air introduction space 352. At this time, some of the EGR gas and the air A are mixed with each other.

As shown in FIG. 3, an inside-casing opening 46 is provided inside the outside air introducing space 40. As shown in FIG. 3, the in-housing opening 46 is an outlet port side that is an end portion on the outlet port 82 side (right side in the figure) in the axial direction (left-right direction in the figure) of the outlet section 8 of the EGR gas introduction pipe 7. It is formed between the end portion 86 and the inner peripheral side end portion 62 of the second side wall 6. In the embodiment shown in FIG. 3, the in-housing opening 46 has an opening surface such as a frustoconical outer peripheral surface.

A silencer device 4 for a supercharger according to some embodiments includes a silencer element 41 described above, a housing 42 including the first side wall 5 and the second side wall 6 described above, an inlet 81 and an outlet 82 described above. EGR gas introduction pipe 7 including an outlet portion 8 having Then, the outer peripheral side opening 401 described above is formed on the outer peripheral side of the outside air introduction space 40 formed between the first side wall 5 and the second side wall 6, and the first center side described above is formed on the first side wall. The opening 51 is formed. Further, in the silencer device 4 for the supercharger, the opening area A1 of the above-described inside opening 46 of the housing at one design point on which it is assumed that the engine 10 operates normally is that the air A of the design flow rate passes through the inside opening 46 of the housing. The flow velocity difference between the flow velocity V1 and the flow velocity V2 is equal to or less than a predetermined value so that the flow velocity V1 of the air A and the flow velocity V2 of the EGR gas when the EGR gas having the design flow rate pass through the outlet 82 are aligned. Is configured to be.

In one embodiment, when the flow velocity V1 of the air A is within ±20% or within ±10% with respect to the flow velocity V2 of the EGR gas, the above “flow velocity difference between the flow velocity V1 and the flow velocity V2”. Is less than or equal to a predetermined value.”
The flow velocity V1 of the air A may be calculated by dividing the design flow rate Q1 of the air A passing through the opening 46 in the housing by the opening area A1 of the opening 46 in the housing. Similarly, the flow velocity V2 of the EGR gas may be calculated by dividing the design flow rate Q2 of the EGR gas passing through the outlet 82 by the opening area A2 of the outlet 82.

According to the above configuration, the EGR gas flowing out from the outlet port 82 of the EGR gas introducing pipe 7 flows in the outside air introducing space 40 along the axial direction, and is close to the rotation center of the compressor 31 of the supercharger 3. It is mainly introduced on the circumference side. The air A introduced into the outside air introduction space 40 from the outer peripheral side opening 401 flows along the outer peripheral side of the EGR gas along the axial direction, and therefore is mainly introduced into the outer peripheral side away from the rotation center of the compressor 31.

Since the relatively high temperature EGR gas introduced to the inner peripheral side of the compressor 31 mixes with the air A having a lower temperature than the EGR gas introduced to the outer peripheral side of the compressor 31, the periphery of the region where the EGR gas and the air A contact each other. There is a risk that condensed water will be generated. Here, the EGR gas may contain foreign matter such as particulate matter (PM) as compared with the air A. Further, since the outer peripheral side of the compressor 31 has a higher peripheral speed than the inner peripheral side, abrasion and damage due to collision of foreign matter such as condensed water are likely to occur. In the silencer device 4 for the supercharger described above, foreign matter such as condensed water is introduced to the inner peripheral side of the compressor 31, so that collision of the foreign matter on the outer peripheral side of the compressor 31 can be suppressed, and thus the wear of the compressor 31 can be suppressed. And damage can be suppressed.

Further, the present inventors have found that by making the flow rates of the EGR gas and the air A flowing through the outside air introduction space 40 uniform, it is possible to suppress the generation of condensed water due to the mixing of the EGR gas and the air A.
According to the above configuration, the opening area A1 of the opening 46 in the housing has a flow velocity V1 of the air A when the air A having the design flow rate passes through the opening 46 in the housing, and the EGR gas having the design flow rate passes through the outlet 82. The flow velocity difference between the flow velocity V1 and the flow velocity V2 is set to be equal to or less than a predetermined value so that the flow velocity V2 of the EGR gas at the time of performing the operation becomes uniform. In this case, the flow velocity difference between the air A passing through the opening 46 in the housing and the EGR gas passing through the outflow port 82 of the EGR gas introducing pipe 7 can be reduced, so that the EGR gas and the air A flowing through the outside air introducing space 40 can be reduced. The flow velocities of and can be equalized. By making the flow velocities of the EGR gas and the air A flowing through the outside air introduction space 40 uniform, it is possible to suppress the generation of vortices when the EGR gas and the air A collide with each other, and by mixing the EGR gas and the air A. Generation of condensed water can be suppressed. By suppressing the generation of the condensed water, it is possible to suppress the condensed water from colliding with the compressor 31, and thus it is possible to suppress the wear and damage of the compressor 31 (supercharger 3).

In some embodiments, the opening area A1 of the opening 46 in the housing is configured such that the above-described flow rate V1 of the air A and the above-described flow rate V2 of the EGR gas are equal in speed. Here, the equivalent velocity means that the flow velocity V1 of the air A is within ±5% of the flow velocity V2 of the EGR gas. In this case, the flow velocity V1 of the air A passing through the opening 46 in the casing and the flow velocity V2 of the EGR gas passing through the outlet 82 become equal in the opening area A1 of the opening 46 in the casing. With this configuration, the flow velocity difference between the flow velocity V1 and the flow velocity V2 can be reduced, so that the generation of condensed water due to the mixing of the EGR gas and the air A can be more effectively suppressed.

In some embodiments, as shown in FIG. 3, the EGR gas introducing pipe 7 has at least one straightening plate 71 provided inside the outlet portion 8. The straightening plate 71 straightens the EGR gas flowing through the outlet portion 8 of the EGR gas introducing pipe 7 by dividing the inside of the outlet portion 8 into a plurality of portions.
In the embodiment shown in FIG. 3, the current plate 71 is formed in a plate shape, and both ends of the plate in the extending direction are connected to the inner peripheral surface 87 of the outlet portion 8 and in the plate thickness direction. Are spaced apart from each other.

According to the above configuration, the EGR gas flowing through the outlet portion 8 of the EGR gas introducing pipe 7 is rectified by the rectifying plate 71, so that the EGR gas flowing out from the outlet 82 of the EGR gas introducing pipe 7 and the outer peripheral side opening 401 It is possible to reduce the flow velocity difference between the air A introduced into the outside air introduction space 40 and the outside air introduction space 40.

In addition, in the embodiment shown in FIG. 3, although three rectifying plates 71 are arranged inside the outlet part 8, a plurality of or one rectifying plate other than three are arranged inside the outlet part 8. Alternatively, the straightening vane may not be arranged inside the outlet portion 8.

In some embodiments, as shown in FIG. 3, the EGR gas introducing pipe 7 includes a plurality of openings 72 partitioned by at least one straightening vane 71 inside the outlet part 8. Each of the plurality of openings 72 is configured such that their opening areas are equal to each other, as shown in FIG. 6 described later. Here, the opening area means an area in a cross section in a direction orthogonal to the axial direction.
In one embodiment configured such that the opening areas of the plurality of openings 72 are equal to each other, the opening area of one opening 72 of the plurality of openings 72 is equal to the opening area of the plurality of openings 72. The condition within ±5% of the opening area of the other opening 72 is satisfied. In one embodiment, as shown in FIG. 3, the EGR gas introduction pipe 7 extends from the inflow port 81 to the outflow port 82, and the plurality of openings 72 satisfy the above condition. When the plurality of openings 72 satisfy the above condition, the plurality of flow straightening plates 71 are not arranged at equal intervals inside the outlet 8 but are biased toward the center side, as shown in FIG. Is located in.

According to the above configuration, the plurality of openings 72 of the EGR gas introduction pipe 7 are configured to have the same opening area, so that the EGR gas flowing through each of the plurality of openings 72 is The flow velocity can be made uniform. By making the flow velocity of the EGR gas flowing through each of the plurality of openings 72 uniform, it is possible to prevent the EGR gas that flows out from each of the outlets 82 of the plurality of openings 72 and flows through the outside air introduction space 40 from becoming a turbulent flow. be able to. By preventing the EGR gas flowing through the outside air introducing space 40 from becoming a turbulent flow, it is possible to prevent the EGR gas flowing through the outside air introducing space 40 and the air A from colliding with each other to generate a vortex. Generation of condensed water due to mixing of gas and air A can be suppressed.
Note that the configuration relating to each of the plurality of openings 72 described above is applicable not only to the illustrated embodiment but also to some of the above-described embodiments and some of the later-described embodiments.

FIG. 4 is a schematic partially enlarged cross-sectional view showing a silencer device for a supercharger and a part of the supercharger according to another embodiment of the present invention in an enlarged manner.
In some embodiments, as shown in FIG. 4, the above-mentioned EGR gas introducing pipe 7 includes the above-mentioned outlet portion 8 and the inlet portion 9 which is arranged outside the housing 42 and has the bent portion 91. ,including. The inlet portion 9 of the EGR gas introduction pipe 7 communicates with the above-described first center side opening 51. Then, as shown in FIG. 4, the outer peripheral wall 88 of the outlet portion 8 connected to the outer peripheral side (outer peripheral wall surface 92) of the curved portion 91 is connected to the inner peripheral side (inner peripheral wall surface 93) of the curved portion 91. Is formed longer than the inner peripheral wall 89 in the axial direction.

In the embodiment shown in FIG. 4, the inlet portion 9 of the EGR gas introduction pipe 7 is a pipe that is provided concentrically with the outlet portion 8, and the end portion on the side of the first side wall 5 is more than the first center side opening 51. It has a flange 474 extending radially outward. As shown in FIG. 4, the inlet portion 9 is bolted to the flange 21 together with the flange portion 85 by the bolt 45 in a state where the flange 474 is in contact with the flange portion 85 of the outlet portion 8 from the outside. Therefore, the inlet 9 is configured to be connectable to and detachable from the housing 42 and the outlet 8.

Further, the screw holes to be screwed into the bolts 45 are provided at a plurality of places at regular intervals in the circumferential direction of the flange 21, and the insertion holes for inserting the shaft portions of the bolts 45 are the screw holes of the flange 21. Correspondingly, the outer peripheral side portion of the flange portion 85 and the flange 474 are provided at a plurality of positions at regular intervals in the circumferential direction. Therefore, the inlet portion 9 and the outlet portion 8 are configured so that the mounting angle in the circumferential direction with respect to the housing 42 can be changed.

The EGR gas that has passed through the curved portion 91 has a flow direction in which the EGR gas swells to the outer peripheral side of the curved portion 91. If the flow direction of the EGR gas in the EGR gas introduction pipe 7 is not corrected along the axial direction, the EGR gas flowing on the outer peripheral side in the flow direction of the EGR gas flows out from the outlet port 82 and then the air A Clash with. When the EGR gas and the air A collide with each other, a vortex is generated, and since the vortex promotes the mixing of the EGR gas and the air A, the generation of condensed water is promoted.

According to the above configuration, by forming the outer peripheral wall 88 located on the outer peripheral side in the EGR gas flow direction to be longer than the inner peripheral wall 89 located on the inner peripheral side in the EGR gas flow direction, the EGR gas introduction pipe 7 The flow direction of the EGR gas flowing on the outer peripheral side inside can be corrected by the outer peripheral wall 88 to the direction along the axial direction. Therefore, the collision between the EGR gas flowing on the outer peripheral side in the flow direction of the EGR gas and the air A can be alleviated. By reducing the collision between the EGR gas and the air A, it is possible to suppress the generation of condensed water.

In some embodiments, as shown in FIG. 4, the above-mentioned EGR gas introducing pipe 7 includes the above-mentioned outlet portion 8 and the inlet portion 9 which is arranged outside the housing 42 and has the bent portion 91. ,including. The inlet portion 9 of the EGR gas introduction pipe 7 communicates with the above-described first center side opening 51. Then, when visually recognizing a cross section as shown in FIG. 4 (a cross section along the axial direction and in which the center line CL of the bent portion 91 exists), at least one rectifying plate 71 is orthogonal to the cross section. It extends along the direction (front direction, back direction with respect to the drawing surface).

In the embodiment shown in FIG. 4, the outer peripheral wall 88 and the inner peripheral wall 89 are separated from each other in the direction orthogonal to the axial direction (vertical direction in the figure) in the above cross section so as to be divided into a plurality of sections. Three straightening vanes 71 are provided. Each of the three straightening vanes 71 has the same length as the length of the outlet portion 8 at the provided position. More specifically, of the three straightening vanes 71, the straightening vane 71 located closest to the outer peripheral wall 88 is formed longer than the other two straightening vanes 71, and is located closest to the inner circumferential wall 89. The 71 is formed shorter than the other two rectifying plates 71.

As described above, the EGR gas that has passed through the curved portion 91 has a flow direction that bulges toward the outer peripheral side of the curved portion 91. If the straightening plate 71 extending along the direction orthogonal to the cross section is not provided as shown in FIG. 4, the EGR gas flow direction in the EGR gas introduction pipe 7 is along the axial direction. Therefore, the EGR gas flowing on the outer peripheral side in the EGR gas flow direction collides with the air A after flowing out from the outflow port 82.

According to the above configuration, since the rectifying plate 71 is provided so as to separate the outer peripheral side and the inner peripheral side in the EGR gas flow direction, the EGR gas flow direction in the EGR gas introduction pipe 7 is set to the axial direction. It can be modified along the direction. By correcting the flow direction of the EGR gas, the collision between the EGR gas and the air A can be mitigated. By reducing the collision between the EGR gas and the air A, it is possible to suppress the generation of condensed water.

As described above, in some embodiments, as shown in FIGS. 3 and 4, the EGR gas introduction pipe 7 described above is configured to be connectable to and detachable from the housing 42. In this case, since the EGR gas introducing pipe 7 can be connected to and disconnected from the housing 42, the EGR gas introducing pipe 7 can be easily replaced. For example, by replacing the EGR gas introduction pipe 7 with another EGR gas introduction pipe 7 having a different length of the outlet portion 8 in the axial direction, the shape of the rectifying plate 71, the mounting angle, etc., generation of condensed water due to mixing, Energy loss can be reduced.

In particular, when the inlet portion 9 and the outlet portion 8 of the EGR gas introduction pipe 7 are separate bodies and the outlet portion 8 is provided with the flow straightening plate 71, the bending direction of the inlet portion 9 is dealt with. In addition, it is possible to change the mounting angle of the outlet portion 8 and the current plate 71 provided in the outlet portion 8 with respect to the housing 42 in the circumferential direction.

FIG. 5 is a view for explaining the drain receiver and the drain discharge device according to the embodiment of the present invention, and is a schematic partially enlarged cross-sectional view showing a silencer device for a supercharger and a part of the supercharger in an enlarged manner. It is a figure. FIG. 6 is a view of the silencer device for the supercharger shown in FIG. 5, viewed from the direction of arrow B in FIG. Note that in FIG. 6, the inlet portion 9 of the EGR gas introduction pipe 7 and a drain discharge pipe 484 described later are omitted for convenience of description.

In some embodiments, as shown in FIG. 5, the supercharger silencer device 4 described above includes the drain receiver 48 arranged in the outer peripheral side opening 401. The term “arranged in the outer peripheral side opening 401 ”means that it is arranged below the lower end of the first side wall 5 and the lower end of the second side wall 6, and between the first side wall 5 and the second side wall. It is included in the position higher than the lower end of the first side wall 5 and the lower end of the second side wall 6.

In the embodiment shown in FIG. 5, the drain receiver 48 is arranged below the lower end of the first side wall 5 and the lower end of the second side wall 6. The drain receiver 48 is formed in a box shape having an opening at the top, the end portion on the first side wall 5 side is fixed to the first side wall 5 by a bolt 485A, and the end portion on the second side wall 6 side. Are fixed to the second side wall 6 by bolts 485B.

More specifically, the drain receiver 48 includes a drain storage part 481, a first fixing part 482, a second fixing part 483, and a drain discharge pipe 484.
The drain storage part 481 is formed in a box shape that covers the lower end of the outer peripheral side opening 401 in the circumferential direction from below.
The first fixing portion 482 extends from the end portion of the drain storage portion 481 on the first side wall 5 side in a direction intersecting the axial direction, and is fixed to the first side wall 5 by a bolt 485A.
The second fixing portion 483 extends from the end of the drain storage portion 481 on the second side wall 6 side in a direction intersecting the axial direction, and is fixed to the second side wall 6 by a bolt 485B.

The drain discharge pipe 484 is provided to discharge the condensed water stored in the drain storage section 481. The opening for discharging the drain from the drain storage part 481 to the drain discharge pipe 484 may be formed on any surface of the drain storage part 481.

According to the above configuration, the condensed water (drain) generated when the EGR gas and the air A merge in the outside air introduction space 40 can be stored in the drain receiver 48 arranged in the outer peripheral side opening 401. Therefore, the condensed water can be prevented from being introduced into the supercharger 3, so that the corrosion and damage of the supercharger 3 due to the condensed water can be suppressed.

In some embodiments, as shown in FIG. 6, the drain receiver 48 described above is configured such that the angle θ in the circumferential direction is equal to or less than a predetermined angle θ1 including the lowest point 486 in the vertical direction. .. The predetermined angle θ1 is 60 degrees. It is preferably 45 degrees. More preferably, it is 30 degrees. In this case, when the air A is introduced into the outside air introducing space 40 from below the outer peripheral side opening 401, the drain receiver 48 does not hinder the introduction of the air A into the outside air introducing space 40 from the outer peripheral side in a well-balanced manner. be able to.
The drain receiver 48 described above is applicable not only to the illustrated embodiment but also to some of the embodiments described above.

In some embodiments, as shown in FIG. 5, the compressor housing 35 has a liquid pool 491 having a storage space in which condensed water generated by mixing EGR gas and air A is stored.
In the embodiment shown in FIG. 5, the liquid pool 491 is defined by the flange 44 described above, the first casing wall 358 of the compressor housing 35, and the second casing wall 359 of the compressor housing 35.
The first casing wall portion 358 of the compressor housing 35 has a surface facing the flange 44 and extends along a direction intersecting (orthogonal to) the axial direction.
The second casing wall portion 359 of the compressor housing 35 extends along the axial direction so as to connect the flange 44 and the first casing wall portion 358.

The silencer device 4 for the supercharger described above includes the drain discharge flow path 49 for flowing the condensed water stored in the liquid reservoir 491 to the drain receiver 48 described above.
In the embodiment shown in FIG. 5, the drain discharge flow path 49 includes a pipe 492 that connects the liquid reservoir 491 and the drain reservoir 481.

According to the above configuration, the condensed water accumulated in the liquid pool portion 491 of the compressor housing 35 can be stored in the drain storage portion 481 by flowing into the drain storage portion 481 via the drain discharge passage 49. By discharging the condensed water from the compressor housing 35 by the drain discharge flow path 49, the condensed water in the compressor housing 35 can be reduced. By reducing the amount of condensed water in the compressor housing 35, it is possible to prevent the condensed water from being introduced into the compressor 31, so that it is possible to suppress corrosion and damage of the compressor 31 due to the condensed water.
The drain discharge passage 49 described above is applicable not only to the illustrated embodiment but also to some of the above-described embodiments.

In some of the embodiments described above, the supercharger 3 and the silencer device 4 for the supercharger were provided in the marine diesel engine 1 (marine internal combustion engine), but the marine diesel engine 1 for land power generation and the like for marine use. It may be provided in an engine other than the diesel engine.
In some of the above-described embodiments, the supercharger 3 to which the silencer device 4 for the supercharger is attached is the turbocharger 3A (exhaust turbine supercharger), but the electric motor is used to drive the compressor. It may be a supercharger other than the turbocharger such as an electric supercharge compressor (electric compressor).

The present invention is not limited to the above-described embodiment, and includes a modified form of the above-described embodiment and a combination of these forms as appropriate. For example, the EGR gas introduction pipe 7 may be integrally provided with the above-mentioned outlet portion 8 and the above-mentioned inlet portion 9.

1 Diesel Engine 10 Engine 11 EGR Device 12 Exhaust Gas Treatment Device 13 Intake Flow Path 14 Exhaust Flow Path 15 Air Cleaner 16 Air Cooler 17 EGR Flow Path 3 Supercharger 3A Turbocharger 31 Compressor 32 Turbine 33 Rotor 34 Bearing 35 Compressor Housing 36 Turbine Housing 37 Bearing housing 4 Supercharger silencer device 40 Outside air introduction space 401 Outer peripheral side opening 41 Silencer element 42 Case 46 Inner case opening 48 Drain receiver 49 Drain discharge flow path 5 First side wall 51 First center side opening 6 Second side wall 61 2nd center side opening 62 Inner peripheral side edge part 7 EGR gas introduction pipe 71 Straightening plate 72 Opening part 8 Outlet part 81 Inlet port 82 Outlet port 86 Outlet port side end part 87 Inner peripheral surface 88 Outer peripheral wall 89 Inner peripheral wall 9 Inlet part 91 Bent portion A Air C Combustion gas E Exhaust gas EGR EGR gas

Claims (9)

A silencer device for a supercharger, which is provided on the intake inlet side of a compressor housing of the supercharger,
Silencer element,
A housing that houses the silencer element and that is configured to introduce air and EGR gas;
An EGR gas introduction pipe for introducing the EGR gas into the housing,
The housing is
A first side wall extending in a direction intersecting the axial direction of the supercharger and having a central side opening;
A second side wall that is provided closer to the compressor housing than the first side wall in the axial direction and forms an outside air introduction space between the first side wall and the second side wall;
On the outer peripheral side of the outside air introducing space, an outer peripheral side opening for introducing the air into the outside air introducing space is formed,
The EGR gas introduction pipe is an outlet portion that is disposed inside the housing and extends in the outside air introduction space along the axial direction, and the central side opening is on one end side of the outlet portion. An outlet part having an inlet part communicating with the outlet part and an outlet part formed on the other end side of the outlet part,
The opening area A1 of the opening in the housing formed between the end portion on the outlet side of the outlet portion and the end portion on the inner peripheral side of the second side wall is
The flow rate V1 of the air when the air of the design flow rate passes through the opening in the housing and the flow rate V2 of the EGR gas when the EGR gas of the design flow rate passes through the outlet are matched. A silencer device for a supercharger configured such that a flow velocity difference between the flow velocity V1 and the flow velocity V2 is equal to or less than a predetermined value. The supercharger silencer device according to claim 1, wherein the opening area A1 is configured such that the flow velocity V1 and the flow velocity V2 are equal. The silencer device for a supercharger according to claim 1, wherein the EGR gas introduction pipe has at least one straightening plate provided inside the outlet portion. The EGR gas introduction pipe includes a plurality of openings inside the outlet, which are partitioned by the at least one straightening plate.
The silencer device for a supercharger according to claim 3, wherein the opening areas of the plurality of openings are equal to each other. The EGR gas introduction pipe is an inlet portion that is arranged outside the housing and has a bent portion, and further includes an inlet portion that communicates with the central opening.
The outer peripheral wall of the outlet section that is continuous with the outer peripheral side of the curved section is formed longer in the axial direction than the inner peripheral wall of the outlet section that is continuous with the inner peripheral side of the curved section. The silencer device for a supercharger according to item 1. The EGR gas introduction pipe is an inlet portion that is arranged outside the housing and has a bent portion, and further includes an inlet portion that communicates with the central opening.
The at least one flow straightening plate extends along a direction orthogonal to the cross section when the cross section along the axial direction and the center line of the bent portion is visually recognized. The silencer device for a supercharger according to item 3. The silencer device for a supercharger according to any one of claims 1 to 4, further comprising a drain receiver arranged in the opening on the outer peripheral side. A supercharger to which the silencer device for a supercharger according to any one of claims 1 to 4 is attached. An engine equipped with the supercharger according to claim 8.

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